net/core/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      NET3    Protocol independent device support routines.
   4  *
   5  *      Derived from the non IP parts of dev.c 1.0.19
   6  *              Authors:        Ross Biro
   7  *                              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   8  *                              Mark Evans, <evansmp@uhura.aston.ac.uk>
   9  *
  10  *      Additional Authors:
  11  *              Florian la Roche <rzsfl@rz.uni-sb.de>
  12  *              Alan Cox <gw4pts@gw4pts.ampr.org>
  13  *              David Hinds <dahinds@users.sourceforge.net>
  14  *              Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
  15  *              Adam Sulmicki <adam@cfar.umd.edu>
  16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
  17  *
  18  *      Changes:
  19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
  20  *                                      to 2 if register_netdev gets called
  21  *                                      before net_dev_init & also removed a
  22  *                                      few lines of code in the process.
  23  *              Alan Cox        :       device private ioctl copies fields back.
  24  *              Alan Cox        :       Transmit queue code does relevant
  25  *                                      stunts to keep the queue safe.
  26  *              Alan Cox        :       Fixed double lock.
  27  *              Alan Cox        :       Fixed promisc NULL pointer trap
  28  *              ????????        :       Support the full private ioctl range
  29  *              Alan Cox        :       Moved ioctl permission check into
  30  *                                      drivers
  31  *              Tim Kordas      :       SIOCADDMULTI/SIOCDELMULTI
  32  *              Alan Cox        :       100 backlog just doesn't cut it when
  33  *                                      you start doing multicast video 8)
  34  *              Alan Cox        :       Rewrote net_bh and list manager.
  35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
  36  *              Alan Cox        :       Took out transmit every packet pass
  37  *                                      Saved a few bytes in the ioctl handler
  38  *              Alan Cox        :       Network driver sets packet type before
  39  *                                      calling netif_rx. Saves a function
  40  *                                      call a packet.
  41  *              Alan Cox        :       Hashed net_bh()
  42  *              Richard Kooijman:       Timestamp fixes.
  43  *              Alan Cox        :       Wrong field in SIOCGIFDSTADDR
  44  *              Alan Cox        :       Device lock protection.
  45  *              Alan Cox        :       Fixed nasty side effect of device close
  46  *                                      changes.
  47  *              Rudi Cilibrasi  :       Pass the right thing to
  48  *                                      set_mac_address()
  49  *              Dave Miller     :       32bit quantity for the device lock to
  50  *                                      make it work out on a Sparc.
  51  *              Bjorn Ekwall    :       Added KERNELD hack.
  52  *              Alan Cox        :       Cleaned up the backlog initialise.
  53  *              Craig Metz      :       SIOCGIFCONF fix if space for under
  54  *                                      1 device.
  55  *          Thomas Bogendoerfer :       Return ENODEV for dev_open, if there
  56  *                                      is no device open function.
  57  *              Andi Kleen      :       Fix error reporting for SIOCGIFCONF
  58  *          Michael Chastain    :       Fix signed/unsigned for SIOCGIFCONF
  59  *              Cyrus Durgin    :       Cleaned for KMOD
  60  *              Adam Sulmicki   :       Bug Fix : Network Device Unload
  61  *                                      A network device unload needs to purge
  62  *                                      the backlog queue.
  63  *      Paul Rusty Russell      :       SIOCSIFNAME
  64  *              Pekka Riikonen  :       Netdev boot-time settings code
  65  *              Andrew Morton   :       Make unregister_netdevice wait
  66  *                                      indefinitely on dev->refcnt
  67  *              J Hadi Salim    :       - Backlog queue sampling
  68  *                                      - netif_rx() feedback
  69  */
  70
  71 #include <linux/uaccess.h>
  72 #include <linux/bitops.h>
  73 #include <linux/capability.h>
  74 #include <linux/cpu.h>
  75 #include <linux/types.h>
  76 #include <linux/kernel.h>
  77 #include <linux/hash.h>
  78 #include <linux/slab.h>
  79 #include <linux/sched.h>
  80 #include <linux/sched/mm.h>
  81 #include <linux/mutex.h>
  82 #include <linux/rwsem.h>
  83 #include <linux/string.h>
  84 #include <linux/mm.h>
  85 #include <linux/socket.h>
  86 #include <linux/sockios.h>
  87 #include <linux/errno.h>
  88 #include <linux/interrupt.h>
  89 #include <linux/if_ether.h>
  90 #include <linux/netdevice.h>
  91 #include <linux/etherdevice.h>
  92 #include <linux/ethtool.h>
  93 #include <linux/skbuff.h>
  94 #include <linux/kthread.h>
  95 #include <linux/bpf.h>
  96 #include <linux/bpf_trace.h>
  97 #include <net/net_namespace.h>
  98 #include <net/sock.h>
  99 #include <net/busy_poll.h>
 100 #include <linux/rtnetlink.h>
 101 #include <linux/stat.h>
 102 #include <net/dsa.h>
 103 #include <net/dst.h>
 104 #include <net/dst_metadata.h>
 105 #include <net/gro.h>
 106 #include <net/pkt_sched.h>
 107 #include <net/pkt_cls.h>
 108 #include <net/checksum.h>
 109 #include <net/xfrm.h>
 110 #include <net/tcx.h>
 111 #include <linux/highmem.h>
 112 #include <linux/init.h>
 113 #include <linux/module.h>
 114 #include <linux/netpoll.h>
 115 #include <linux/rcupdate.h>
 116 #include <linux/delay.h>
 117 #include <net/iw_handler.h>
 118 #include <asm/current.h>
 119 #include <linux/audit.h>
 120 #include <linux/dmaengine.h>
 121 #include <linux/err.h>
 122 #include <linux/ctype.h>
 123 #include <linux/if_arp.h>
 124 #include <linux/if_vlan.h>
 125 #include <linux/ip.h>
 126 #include <net/ip.h>
 127 #include <net/mpls.h>
 128 #include <linux/ipv6.h>
 129 #include <linux/in.h>
 130 #include <linux/jhash.h>
 131 #include <linux/random.h>
 132 #include <trace/events/napi.h>
 133 #include <trace/events/net.h>
 134 #include <trace/events/skb.h>
 135 #include <trace/events/qdisc.h>
 136 #include <trace/events/xdp.h>
 137 #include <linux/inetdevice.h>
 138 #include <linux/cpu_rmap.h>
 139 #include <linux/static_key.h>
 140 #include <linux/hashtable.h>
 141 #include <linux/vmalloc.h>
 142 #include <linux/if_macvlan.h>
 143 #include <linux/errqueue.h>
 144 #include <linux/hrtimer.h>
 145 #include <linux/netfilter_netdev.h>
 146 #include <linux/crash_dump.h>
 147 #include <linux/sctp.h>
 148 #include <net/udp_tunnel.h>
 149 #include <linux/net_namespace.h>
 150 #include <linux/indirect_call_wrapper.h>
 151 #include <net/devlink.h>
 152 #include <linux/pm_runtime.h>
 153 #include <linux/prandom.h>
 154 #include <linux/once_lite.h>
 155 #include <net/netdev_rx_queue.h>
 156
 157 #include "dev.h"
 158 #include "net-sysfs.h"
 159
 160 static DEFINE_SPINLOCK(ptype_lock);
 161 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 162 struct list_head ptype_all __read_mostly;       /* Taps */
 163
 164 static int netif_rx_internal(struct sk_buff *skb);
 165 static int call_netdevice_notifiers_extack(unsigned long val,
 166                                            struct net_device *dev,
 167                                            struct netlink_ext_ack *extack);
 168 static struct napi_struct *napi_by_id(unsigned int napi_id);
 169
 170 /*
 171  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
 172  * semaphore.
 173  *
 174  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
 175  *
 176  * Writers must hold the rtnl semaphore while they loop through the
 177  * dev_base_head list, and hold dev_base_lock for writing when they do the
 178  * actual updates.  This allows pure readers to access the list even
 179  * while a writer is preparing to update it.
 180  *
 181  * To put it another way, dev_base_lock is held for writing only to
 182  * protect against pure readers; the rtnl semaphore provides the
 183  * protection against other writers.
 184  *
 185  * See, for example usages, register_netdevice() and
 186  * unregister_netdevice(), which must be called with the rtnl
 187  * semaphore held.
 188  */
 189 DEFINE_RWLOCK(dev_base_lock);
 190 EXPORT_SYMBOL(dev_base_lock);
 191
 192 static DEFINE_MUTEX(ifalias_mutex);
 193
 194 /* protects napi_hash addition/deletion and napi_gen_id */
 195 static DEFINE_SPINLOCK(napi_hash_lock);
 196
 197 static unsigned int napi_gen_id = NR_CPUS;
 198 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
 199
 200 static DECLARE_RWSEM(devnet_rename_sem);
 201
 202 static inline void dev_base_seq_inc(struct net *net)
 203 {
 204         while (++net->dev_base_seq == 0)
 205                 ;
 206 }
 207
 208 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
 209 {
 210         unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
 211
 212         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
 213 }
 214
 215 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
 216 {
 217         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
 218 }
 219
 220 static inline void rps_lock_irqsave(struct softnet_data *sd,
 221                                     unsigned long *flags)
 222 {
 223         if (IS_ENABLED(CONFIG_RPS))
 224                 spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
 225         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 226                 local_irq_save(*flags);
 227 }
 228
 229 static inline void rps_lock_irq_disable(struct softnet_data *sd)
 230 {
 231         if (IS_ENABLED(CONFIG_RPS))
 232                 spin_lock_irq(&sd->input_pkt_queue.lock);
 233         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 234                 local_irq_disable();
 235 }
 236
 237 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
 238                                           unsigned long *flags)
 239 {
 240         if (IS_ENABLED(CONFIG_RPS))
 241                 spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
 242         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 243                 local_irq_restore(*flags);
 244 }
 245
 246 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
 247 {
 248         if (IS_ENABLED(CONFIG_RPS))
 249                 spin_unlock_irq(&sd->input_pkt_queue.lock);
 250         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 251                 local_irq_enable();
 252 }
 253
 254 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
 255                                                        const char *name)
 256 {
 257         struct netdev_name_node *name_node;
 258
 259         name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
 260         if (!name_node)
 261                 return NULL;
 262         INIT_HLIST_NODE(&name_node->hlist);
 263         name_node->dev = dev;
 264         name_node->name = name;
 265         return name_node;
 266 }
 267
 268 static struct netdev_name_node *
 269 netdev_name_node_head_alloc(struct net_device *dev)
 270 {
 271         struct netdev_name_node *name_node;
 272
 273         name_node = netdev_name_node_alloc(dev, dev->name);
 274         if (!name_node)
 275                 return NULL;
 276         INIT_LIST_HEAD(&name_node->list);
 277         return name_node;
 278 }
 279
 280 static void netdev_name_node_free(struct netdev_name_node *name_node)
 281 {
 282         kfree(name_node);
 283 }
 284
 285 static void netdev_name_node_add(struct net *net,
 286                                  struct netdev_name_node *name_node)
 287 {
 288         hlist_add_head_rcu(&name_node->hlist,
 289                            dev_name_hash(net, name_node->name));
 290 }
 291
 292 static void netdev_name_node_del(struct netdev_name_node *name_node)
 293 {
 294         hlist_del_rcu(&name_node->hlist);
 295 }
 296
 297 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
 298                                                         const char *name)
 299 {
 300         struct hlist_head *head = dev_name_hash(net, name);
 301         struct netdev_name_node *name_node;
 302
 303         hlist_for_each_entry(name_node, head, hlist)
 304                 if (!strcmp(name_node->name, name))
 305                         return name_node;
 306         return NULL;
 307 }
 308
 309 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
 310                                                             const char *name)
 311 {
 312         struct hlist_head *head = dev_name_hash(net, name);
 313         struct netdev_name_node *name_node;
 314
 315         hlist_for_each_entry_rcu(name_node, head, hlist)
 316                 if (!strcmp(name_node->name, name))
 317                         return name_node;
 318         return NULL;
 319 }
 320
 321 bool netdev_name_in_use(struct net *net, const char *name)
 322 {
 323         return netdev_name_node_lookup(net, name);
 324 }
 325 EXPORT_SYMBOL(netdev_name_in_use);
 326
 327 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
 328 {
 329         struct netdev_name_node *name_node;
 330         struct net *net = dev_net(dev);
 331
 332         name_node = netdev_name_node_lookup(net, name);
 333         if (name_node)
 334                 return -EEXIST;
 335         name_node = netdev_name_node_alloc(dev, name);
 336         if (!name_node)
 337                 return -ENOMEM;
 338         netdev_name_node_add(net, name_node);
 339         /* The node that holds dev->name acts as a head of per-device list. */
 340         list_add_tail(&name_node->list, &dev->name_node->list);
 341
 342         return 0;
 343 }
 344
 345 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
 346 {
 347         list_del(&name_node->list);
 348         netdev_name_node_del(name_node);
 349         kfree(name_node->name);
 350         netdev_name_node_free(name_node);
 351 }
 352
 353 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
 354 {
 355         struct netdev_name_node *name_node;
 356         struct net *net = dev_net(dev);
 357
 358         name_node = netdev_name_node_lookup(net, name);
 359         if (!name_node)
 360                 return -ENOENT;
 361         /* lookup might have found our primary name or a name belonging
 362          * to another device.
 363          */
 364         if (name_node == dev->name_node || name_node->dev != dev)
 365                 return -EINVAL;
 366
 367         __netdev_name_node_alt_destroy(name_node);
 368
 369         return 0;
 370 }
 371
 372 static void netdev_name_node_alt_flush(struct net_device *dev)
 373 {
 374         struct netdev_name_node *name_node, *tmp;
 375
 376         list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
 377                 __netdev_name_node_alt_destroy(name_node);
 378 }
 379
 380 /* Device list insertion */
 381 static void list_netdevice(struct net_device *dev)
 382 {
 383         struct net *net = dev_net(dev);
 384
 385         ASSERT_RTNL();
 386
 387         write_lock(&dev_base_lock);
 388         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
 389         netdev_name_node_add(net, dev->name_node);
 390         hlist_add_head_rcu(&dev->index_hlist,
 391                            dev_index_hash(net, dev->ifindex));
 392         write_unlock(&dev_base_lock);
 393         /* We reserved the ifindex, this can't fail */
 394         WARN_ON(xa_store(&net->dev_by_index, dev->ifindex, dev, GFP_KERNEL));
 395
 396         dev_base_seq_inc(net);
 397 }
 398
 399 /* Device list removal
 400  * caller must respect a RCU grace period before freeing/reusing dev
 401  */
 402 static void unlist_netdevice(struct net_device *dev, bool lock)
 403 {
 404         struct net *net = dev_net(dev);
 405
 406         ASSERT_RTNL();
 407
 408         xa_erase(&net->dev_by_index, dev->ifindex);
 409
 410         /* Unlink dev from the device chain */
 411         if (lock)
 412                 write_lock(&dev_base_lock);
 413         list_del_rcu(&dev->dev_list);
 414         netdev_name_node_del(dev->name_node);
 415         hlist_del_rcu(&dev->index_hlist);
 416         if (lock)
 417                 write_unlock(&dev_base_lock);
 418
 419         dev_base_seq_inc(dev_net(dev));
 420 }
 421
 422 /*
 423  *      Our notifier list
 424  */
 425
 426 static RAW_NOTIFIER_HEAD(netdev_chain);
 427
 428 /*
 429  *      Device drivers call our routines to queue packets here. We empty the
 430  *      queue in the local softnet handler.
 431  */
 432
 433 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
 434 EXPORT_PER_CPU_SYMBOL(softnet_data);
 435
 436 #ifdef CONFIG_LOCKDEP
 437 /*
 438  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
 439  * according to dev->type
 440  */
 441 static const unsigned short netdev_lock_type[] = {
 442          ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
 443          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
 444          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
 445          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
 446          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
 447          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
 448          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
 449          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
 450          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
 451          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
 452          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
 453          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
 454          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
 455          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
 456          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
 457
 458 static const char *const netdev_lock_name[] = {
 459         "_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
 460         "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
 461         "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
 462         "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
 463         "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
 464         "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
 465         "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
 466         "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
 467         "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
 468         "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
 469         "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
 470         "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
 471         "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
 472         "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
 473         "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
 474
 475 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
 476 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
 477
 478 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
 479 {
 480         int i;
 481
 482         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
 483                 if (netdev_lock_type[i] == dev_type)
 484                         return i;
 485         /* the last key is used by default */
 486         return ARRAY_SIZE(netdev_lock_type) - 1;
 487 }
 488
 489 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 490                                                  unsigned short dev_type)
 491 {
 492         int i;
 493
 494         i = netdev_lock_pos(dev_type);
 495         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
 496                                    netdev_lock_name[i]);
 497 }
 498
 499 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 500 {
 501         int i;
 502
 503         i = netdev_lock_pos(dev->type);
 504         lockdep_set_class_and_name(&dev->addr_list_lock,
 505                                    &netdev_addr_lock_key[i],
 506                                    netdev_lock_name[i]);
 507 }
 508 #else
 509 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 510                                                  unsigned short dev_type)
 511 {
 512 }
 513
 514 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 515 {
 516 }
 517 #endif
 518
 519 /*******************************************************************************
 520  *
 521  *              Protocol management and registration routines
 522  *
 523  *******************************************************************************/
 524
 525
 526 /*
 527  *      Add a protocol ID to the list. Now that the input handler is
 528  *      smarter we can dispense with all the messy stuff that used to be
 529  *      here.
 530  *
 531  *      BEWARE!!! Protocol handlers, mangling input packets,
 532  *      MUST BE last in hash buckets and checking protocol handlers
 533  *      MUST start from promiscuous ptype_all chain in net_bh.
 534  *      It is true now, do not change it.
 535  *      Explanation follows: if protocol handler, mangling packet, will
 536  *      be the first on list, it is not able to sense, that packet
 537  *      is cloned and should be copied-on-write, so that it will
 538  *      change it and subsequent readers will get broken packet.
 539  *                                                      --ANK (980803)
 540  */
 541
 542 static inline struct list_head *ptype_head(const struct packet_type *pt)
 543 {
 544         if (pt->type == htons(ETH_P_ALL))
 545                 return pt->dev ? &pt->dev->ptype_all : &ptype_all;
 546         else
 547                 return pt->dev ? &pt->dev->ptype_specific :
 548                                  &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
 549 }
 550
 551 /**
 552  *      dev_add_pack - add packet handler
 553  *      @pt: packet type declaration
 554  *
 555  *      Add a protocol handler to the networking stack. The passed &packet_type
 556  *      is linked into kernel lists and may not be freed until it has been
 557  *      removed from the kernel lists.
 558  *
 559  *      This call does not sleep therefore it can not
 560  *      guarantee all CPU's that are in middle of receiving packets
 561  *      will see the new packet type (until the next received packet).
 562  */
 563
 564 void dev_add_pack(struct packet_type *pt)
 565 {
 566         struct list_head *head = ptype_head(pt);
 567
 568         spin_lock(&ptype_lock);
 569         list_add_rcu(&pt->list, head);
 570         spin_unlock(&ptype_lock);
 571 }
 572 EXPORT_SYMBOL(dev_add_pack);
 573
 574 /**
 575  *      __dev_remove_pack        - remove packet handler
 576  *      @pt: packet type declaration
 577  *
 578  *      Remove a protocol handler that was previously added to the kernel
 579  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 580  *      from the kernel lists and can be freed or reused once this function
 581  *      returns.
 582  *
 583  *      The packet type might still be in use by receivers
 584  *      and must not be freed until after all the CPU's have gone
 585  *      through a quiescent state.
 586  */
 587 void __dev_remove_pack(struct packet_type *pt)
 588 {
 589         struct list_head *head = ptype_head(pt);
 590         struct packet_type *pt1;
 591
 592         spin_lock(&ptype_lock);
 593
 594         list_for_each_entry(pt1, head, list) {
 595                 if (pt == pt1) {
 596                         list_del_rcu(&pt->list);
 597                         goto out;
 598                 }
 599         }
 600
 601         pr_warn("dev_remove_pack: %p not found\n", pt);
 602 out:
 603         spin_unlock(&ptype_lock);
 604 }
 605 EXPORT_SYMBOL(__dev_remove_pack);
 606
 607 /**
 608  *      dev_remove_pack  - remove packet handler
 609  *      @pt: packet type declaration
 610  *
 611  *      Remove a protocol handler that was previously added to the kernel
 612  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 613  *      from the kernel lists and can be freed or reused once this function
 614  *      returns.
 615  *
 616  *      This call sleeps to guarantee that no CPU is looking at the packet
 617  *      type after return.
 618  */
 619 void dev_remove_pack(struct packet_type *pt)
 620 {
 621         __dev_remove_pack(pt);
 622
 623         synchronize_net();
 624 }
 625 EXPORT_SYMBOL(dev_remove_pack);
 626
 627
 628 /*******************************************************************************
 629  *
 630  *                          Device Interface Subroutines
 631  *
 632  *******************************************************************************/
 633
 634 /**
 635  *      dev_get_iflink  - get 'iflink' value of a interface
 636  *      @dev: targeted interface
 637  *
 638  *      Indicates the ifindex the interface is linked to.
 639  *      Physical interfaces have the same 'ifindex' and 'iflink' values.
 640  */
 641
 642 int dev_get_iflink(const struct net_device *dev)
 643 {
 644         if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
 645                 return dev->netdev_ops->ndo_get_iflink(dev);
 646
 647         return dev->ifindex;
 648 }
 649 EXPORT_SYMBOL(dev_get_iflink);
 650
 651 /**
 652  *      dev_fill_metadata_dst - Retrieve tunnel egress information.
 653  *      @dev: targeted interface
 654  *      @skb: The packet.
 655  *
 656  *      For better visibility of tunnel traffic OVS needs to retrieve
 657  *      egress tunnel information for a packet. Following API allows
 658  *      user to get this info.
 659  */
 660 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 661 {
 662         struct ip_tunnel_info *info;
 663
 664         if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
 665                 return -EINVAL;
 666
 667         info = skb_tunnel_info_unclone(skb);
 668         if (!info)
 669                 return -ENOMEM;
 670         if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
 671                 return -EINVAL;
 672
 673         return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
 674 }
 675 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
 676
 677 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
 678 {
 679         int k = stack->num_paths++;
 680
 681         if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
 682                 return NULL;
 683
 684         return &stack->path[k];
 685 }
 686
 687 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
 688                           struct net_device_path_stack *stack)
 689 {
 690         const struct net_device *last_dev;
 691         struct net_device_path_ctx ctx = {
 692                 .dev    = dev,
 693         };
 694         struct net_device_path *path;
 695         int ret = 0;
 696
 697         memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
 698         stack->num_paths = 0;
 699         while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
 700                 last_dev = ctx.dev;
 701                 path = dev_fwd_path(stack);
 702                 if (!path)
 703                         return -1;
 704
 705                 memset(path, 0, sizeof(struct net_device_path));
 706                 ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
 707                 if (ret < 0)
 708                         return -1;
 709
 710                 if (WARN_ON_ONCE(last_dev == ctx.dev))
 711                         return -1;
 712         }
 713
 714         if (!ctx.dev)
 715                 return ret;
 716
 717         path = dev_fwd_path(stack);
 718         if (!path)
 719                 return -1;
 720         path->type = DEV_PATH_ETHERNET;
 721         path->dev = ctx.dev;
 722
 723         return ret;
 724 }
 725 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
 726
 727 /**
 728  *      __dev_get_by_name       - find a device by its name
 729  *      @net: the applicable net namespace
 730  *      @name: name to find
 731  *
 732  *      Find an interface by name. Must be called under RTNL semaphore
 733  *      or @dev_base_lock. If the name is found a pointer to the device
 734  *      is returned. If the name is not found then %NULL is returned. The
 735  *      reference counters are not incremented so the caller must be
 736  *      careful with locks.
 737  */
 738
 739 struct net_device *__dev_get_by_name(struct net *net, const char *name)
 740 {
 741         struct netdev_name_node *node_name;
 742
 743         node_name = netdev_name_node_lookup(net, name);
 744         return node_name ? node_name->dev : NULL;
 745 }
 746 EXPORT_SYMBOL(__dev_get_by_name);
 747
 748 /**
 749  * dev_get_by_name_rcu  - find a device by its name
 750  * @net: the applicable net namespace
 751  * @name: name to find
 752  *
 753  * Find an interface by name.
 754  * If the name is found a pointer to the device is returned.
 755  * If the name is not found then %NULL is returned.
 756  * The reference counters are not incremented so the caller must be
 757  * careful with locks. The caller must hold RCU lock.
 758  */
 759
 760 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
 761 {
 762         struct netdev_name_node *node_name;
 763
 764         node_name = netdev_name_node_lookup_rcu(net, name);
 765         return node_name ? node_name->dev : NULL;
 766 }
 767 EXPORT_SYMBOL(dev_get_by_name_rcu);
 768
 769 /* Deprecated for new users, call netdev_get_by_name() instead */
 770 struct net_device *dev_get_by_name(struct net *net, const char *name)
 771 {
 772         struct net_device *dev;
 773
 774         rcu_read_lock();
 775         dev = dev_get_by_name_rcu(net, name);
 776         dev_hold(dev);
 777         rcu_read_unlock();
 778         return dev;
 779 }
 780 EXPORT_SYMBOL(dev_get_by_name);
 781
 782 /**
 783  *      netdev_get_by_name() - find a device by its name
 784  *      @net: the applicable net namespace
 785  *      @name: name to find
 786  *      @tracker: tracking object for the acquired reference
 787  *      @gfp: allocation flags for the tracker
 788  *
 789  *      Find an interface by name. This can be called from any
 790  *      context and does its own locking. The returned handle has
 791  *      the usage count incremented and the caller must use netdev_put() to
 792  *      release it when it is no longer needed. %NULL is returned if no
 793  *      matching device is found.
 794  */
 795 struct net_device *netdev_get_by_name(struct net *net, const char *name,
 796                                       netdevice_tracker *tracker, gfp_t gfp)
 797 {
 798         struct net_device *dev;
 799
 800         dev = dev_get_by_name(net, name);
 801         if (dev)
 802                 netdev_tracker_alloc(dev, tracker, gfp);
 803         return dev;
 804 }
 805 EXPORT_SYMBOL(netdev_get_by_name);
 806
 807 /**
 808  *      __dev_get_by_index - find a device by its ifindex
 809  *      @net: the applicable net namespace
 810  *      @ifindex: index of device
 811  *
 812  *      Search for an interface by index. Returns %NULL if the device
 813  *      is not found or a pointer to the device. The device has not
 814  *      had its reference counter increased so the caller must be careful
 815  *      about locking. The caller must hold either the RTNL semaphore
 816  *      or @dev_base_lock.
 817  */
 818
 819 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
 820 {
 821         struct net_device *dev;
 822         struct hlist_head *head = dev_index_hash(net, ifindex);
 823
 824         hlist_for_each_entry(dev, head, index_hlist)
 825                 if (dev->ifindex == ifindex)
 826                         return dev;
 827
 828         return NULL;
 829 }
 830 EXPORT_SYMBOL(__dev_get_by_index);
 831
 832 /**
 833  *      dev_get_by_index_rcu - find a device by its ifindex
 834  *      @net: the applicable net namespace
 835  *      @ifindex: index of device
 836  *
 837  *      Search for an interface by index. Returns %NULL if the device
 838  *      is not found or a pointer to the device. The device has not
 839  *      had its reference counter increased so the caller must be careful
 840  *      about locking. The caller must hold RCU lock.
 841  */
 842
 843 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
 844 {
 845         struct net_device *dev;
 846         struct hlist_head *head = dev_index_hash(net, ifindex);
 847
 848         hlist_for_each_entry_rcu(dev, head, index_hlist)
 849                 if (dev->ifindex == ifindex)
 850                         return dev;
 851
 852         return NULL;
 853 }
 854 EXPORT_SYMBOL(dev_get_by_index_rcu);
 855
 856 /* Deprecated for new users, call netdev_get_by_index() instead */
 857 struct net_device *dev_get_by_index(struct net *net, int ifindex)
 858 {
 859         struct net_device *dev;
 860
 861         rcu_read_lock();
 862         dev = dev_get_by_index_rcu(net, ifindex);
 863         dev_hold(dev);
 864         rcu_read_unlock();
 865         return dev;
 866 }
 867 EXPORT_SYMBOL(dev_get_by_index);
 868
 869 /**
 870  *      netdev_get_by_index() - find a device by its ifindex
 871  *      @net: the applicable net namespace
 872  *      @ifindex: index of device
 873  *      @tracker: tracking object for the acquired reference
 874  *      @gfp: allocation flags for the tracker
 875  *
 876  *      Search for an interface by index. Returns NULL if the device
 877  *      is not found or a pointer to the device. The device returned has
 878  *      had a reference added and the pointer is safe until the user calls
 879  *      netdev_put() to indicate they have finished with it.
 880  */
 881 struct net_device *netdev_get_by_index(struct net *net, int ifindex,
 882                                        netdevice_tracker *tracker, gfp_t gfp)
 883 {
 884         struct net_device *dev;
 885
 886         dev = dev_get_by_index(net, ifindex);
 887         if (dev)
 888                 netdev_tracker_alloc(dev, tracker, gfp);
 889         return dev;
 890 }
 891 EXPORT_SYMBOL(netdev_get_by_index);
 892
 893 /**
 894  *      dev_get_by_napi_id - find a device by napi_id
 895  *      @napi_id: ID of the NAPI struct
 896  *
 897  *      Search for an interface by NAPI ID. Returns %NULL if the device
 898  *      is not found or a pointer to the device. The device has not had
 899  *      its reference counter increased so the caller must be careful
 900  *      about locking. The caller must hold RCU lock.
 901  */
 902
 903 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
 904 {
 905         struct napi_struct *napi;
 906
 907         WARN_ON_ONCE(!rcu_read_lock_held());
 908
 909         if (napi_id < MIN_NAPI_ID)
 910                 return NULL;
 911
 912         napi = napi_by_id(napi_id);
 913
 914         return napi ? napi->dev : NULL;
 915 }
 916 EXPORT_SYMBOL(dev_get_by_napi_id);
 917
 918 /**
 919  *      netdev_get_name - get a netdevice name, knowing its ifindex.
 920  *      @net: network namespace
 921  *      @name: a pointer to the buffer where the name will be stored.
 922  *      @ifindex: the ifindex of the interface to get the name from.
 923  */
 924 int netdev_get_name(struct net *net, char *name, int ifindex)
 925 {
 926         struct net_device *dev;
 927         int ret;
 928
 929         down_read(&devnet_rename_sem);
 930         rcu_read_lock();
 931
 932         dev = dev_get_by_index_rcu(net, ifindex);
 933         if (!dev) {
 934                 ret = -ENODEV;
 935                 goto out;
 936         }
 937
 938         strcpy(name, dev->name);
 939
 940         ret = 0;
 941 out:
 942         rcu_read_unlock();
 943         up_read(&devnet_rename_sem);
 944         return ret;
 945 }
 946
 947 /**
 948  *      dev_getbyhwaddr_rcu - find a device by its hardware address
 949  *      @net: the applicable net namespace
 950  *      @type: media type of device
 951  *      @ha: hardware address
 952  *
 953  *      Search for an interface by MAC address. Returns NULL if the device
 954  *      is not found or a pointer to the device.
 955  *      The caller must hold RCU or RTNL.
 956  *      The returned device has not had its ref count increased
 957  *      and the caller must therefore be careful about locking
 958  *
 959  */
 960
 961 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
 962                                        const char *ha)
 963 {
 964         struct net_device *dev;
 965
 966         for_each_netdev_rcu(net, dev)
 967                 if (dev->type == type &&
 968                     !memcmp(dev->dev_addr, ha, dev->addr_len))
 969                         return dev;
 970
 971         return NULL;
 972 }
 973 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
 974
 975 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
 976 {
 977         struct net_device *dev, *ret = NULL;
 978
 979         rcu_read_lock();
 980         for_each_netdev_rcu(net, dev)
 981                 if (dev->type == type) {
 982                         dev_hold(dev);
 983                         ret = dev;
 984                         break;
 985                 }
 986         rcu_read_unlock();
 987         return ret;
 988 }
 989 EXPORT_SYMBOL(dev_getfirstbyhwtype);
 990
 991 /**
 992  *      __dev_get_by_flags - find any device with given flags
 993  *      @net: the applicable net namespace
 994  *      @if_flags: IFF_* values
 995  *      @mask: bitmask of bits in if_flags to check
 996  *
 997  *      Search for any interface with the given flags. Returns NULL if a device
 998  *      is not found or a pointer to the device. Must be called inside
 999  *      rtnl_lock(), and result refcount is unchanged.
1000  */
1001
1002 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1003                                       unsigned short mask)
1004 {
1005         struct net_device *dev, *ret;
1006
1007         ASSERT_RTNL();
1008
1009         ret = NULL;
1010         for_each_netdev(net, dev) {
1011                 if (((dev->flags ^ if_flags) & mask) == 0) {
1012                         ret = dev;
1013                         break;
1014                 }
1015         }
1016         return ret;
1017 }
1018 EXPORT_SYMBOL(__dev_get_by_flags);
1019
1020 /**
1021  *      dev_valid_name - check if name is okay for network device
1022  *      @name: name string
1023  *
1024  *      Network device names need to be valid file names to
1025  *      allow sysfs to work.  We also disallow any kind of
1026  *      whitespace.
1027  */
1028 bool dev_valid_name(const char *name)
1029 {
1030         if (*name == '\0')
1031                 return false;
1032         if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1033                 return false;
1034         if (!strcmp(name, ".") || !strcmp(name, ".."))
1035                 return false;
1036
1037         while (*name) {
1038                 if (*name == '/' || *name == ':' || isspace(*name))
1039                         return false;
1040                 name++;
1041         }
1042         return true;
1043 }
1044 EXPORT_SYMBOL(dev_valid_name);
1045
1046 /**
1047  *      __dev_alloc_name - allocate a name for a device
1048  *      @net: network namespace to allocate the device name in
1049  *      @name: name format string
1050  *      @buf:  scratch buffer and result name string
1051  *
1052  *      Passed a format string - eg "lt%d" it will try and find a suitable
1053  *      id. It scans list of devices to build up a free map, then chooses
1054  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1055  *      while allocating the name and adding the device in order to avoid
1056  *      duplicates.
1057  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1058  *      Returns the number of the unit assigned or a negative errno code.
1059  */
1060
1061 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1062 {
1063         int i = 0;
1064         const char *p;
1065         const int max_netdevices = 8*PAGE_SIZE;
1066         unsigned long *inuse;
1067         struct net_device *d;
1068
1069         if (!dev_valid_name(name))
1070                 return -EINVAL;
1071
1072         p = strchr(name, '%');
1073         if (p) {
1074                 /*
1075                  * Verify the string as this thing may have come from
1076                  * the user.  There must be either one "%d" and no other "%"
1077                  * characters.
1078                  */
1079                 if (p[1] != 'd' || strchr(p + 2, '%'))
1080                         return -EINVAL;
1081
1082                 /* Use one page as a bit array of possible slots */
1083                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1084                 if (!inuse)
1085                         return -ENOMEM;
1086
1087                 for_each_netdev(net, d) {
1088                         struct netdev_name_node *name_node;
1089                         list_for_each_entry(name_node, &d->name_node->list, list) {
1090                                 if (!sscanf(name_node->name, name, &i))
1091                                         continue;
1092                                 if (i < 0 || i >= max_netdevices)
1093                                         continue;
1094
1095                                 /*  avoid cases where sscanf is not exact inverse of printf */
1096                                 snprintf(buf, IFNAMSIZ, name, i);
1097                                 if (!strncmp(buf, name_node->name, IFNAMSIZ))
1098                                         __set_bit(i, inuse);
1099                         }
1100                         if (!sscanf(d->name, name, &i))
1101                                 continue;
1102                         if (i < 0 || i >= max_netdevices)
1103                                 continue;
1104
1105                         /*  avoid cases where sscanf is not exact inverse of printf */
1106                         snprintf(buf, IFNAMSIZ, name, i);
1107                         if (!strncmp(buf, d->name, IFNAMSIZ))
1108                                 __set_bit(i, inuse);
1109                 }
1110
1111                 i = find_first_zero_bit(inuse, max_netdevices);
1112                 free_page((unsigned long) inuse);
1113         }
1114
1115         snprintf(buf, IFNAMSIZ, name, i);
1116         if (!netdev_name_in_use(net, buf))
1117                 return i;
1118
1119         /* It is possible to run out of possible slots
1120          * when the name is long and there isn't enough space left
1121          * for the digits, or if all bits are used.
1122          */
1123         return -ENFILE;
1124 }
1125
1126 static int dev_alloc_name_ns(struct net *net,
1127                              struct net_device *dev,
1128                              const char *name)
1129 {
1130         char buf[IFNAMSIZ];
1131         int ret;
1132
1133         BUG_ON(!net);
1134         ret = __dev_alloc_name(net, name, buf);
1135         if (ret >= 0)
1136                 strscpy(dev->name, buf, IFNAMSIZ);
1137         return ret;
1138 }
1139
1140 /**
1141  *      dev_alloc_name - allocate a name for a device
1142  *      @dev: device
1143  *      @name: name format string
1144  *
1145  *      Passed a format string - eg "lt%d" it will try and find a suitable
1146  *      id. It scans list of devices to build up a free map, then chooses
1147  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1148  *      while allocating the name and adding the device in order to avoid
1149  *      duplicates.
1150  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1151  *      Returns the number of the unit assigned or a negative errno code.
1152  */
1153
1154 int dev_alloc_name(struct net_device *dev, const char *name)
1155 {
1156         return dev_alloc_name_ns(dev_net(dev), dev, name);
1157 }
1158 EXPORT_SYMBOL(dev_alloc_name);
1159
1160 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1161                               const char *name)
1162 {
1163         BUG_ON(!net);
1164
1165         if (!dev_valid_name(name))
1166                 return -EINVAL;
1167
1168         if (strchr(name, '%'))
1169                 return dev_alloc_name_ns(net, dev, name);
1170         else if (netdev_name_in_use(net, name))
1171                 return -EEXIST;
1172         else if (dev->name != name)
1173                 strscpy(dev->name, name, IFNAMSIZ);
1174
1175         return 0;
1176 }
1177
1178 /**
1179  *      dev_change_name - change name of a device
1180  *      @dev: device
1181  *      @newname: name (or format string) must be at least IFNAMSIZ
1182  *
1183  *      Change name of a device, can pass format strings "eth%d".
1184  *      for wildcarding.
1185  */
1186 int dev_change_name(struct net_device *dev, const char *newname)
1187 {
1188         unsigned char old_assign_type;
1189         char oldname[IFNAMSIZ];
1190         int err = 0;
1191         int ret;
1192         struct net *net;
1193
1194         ASSERT_RTNL();
1195         BUG_ON(!dev_net(dev));
1196
1197         net = dev_net(dev);
1198
1199         down_write(&devnet_rename_sem);
1200
1201         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1202                 up_write(&devnet_rename_sem);
1203                 return 0;
1204         }
1205
1206         memcpy(oldname, dev->name, IFNAMSIZ);
1207
1208         err = dev_get_valid_name(net, dev, newname);
1209         if (err < 0) {
1210                 up_write(&devnet_rename_sem);
1211                 return err;
1212         }
1213
1214         if (oldname[0] && !strchr(oldname, '%'))
1215                 netdev_info(dev, "renamed from %s%s\n", oldname,
1216                             dev->flags & IFF_UP ? " (while UP)" : "");
1217
1218         old_assign_type = dev->name_assign_type;
1219         dev->name_assign_type = NET_NAME_RENAMED;
1220
1221 rollback:
1222         ret = device_rename(&dev->dev, dev->name);
1223         if (ret) {
1224                 memcpy(dev->name, oldname, IFNAMSIZ);
1225                 dev->name_assign_type = old_assign_type;
1226                 up_write(&devnet_rename_sem);
1227                 return ret;
1228         }
1229
1230         up_write(&devnet_rename_sem);
1231
1232         netdev_adjacent_rename_links(dev, oldname);
1233
1234         write_lock(&dev_base_lock);
1235         netdev_name_node_del(dev->name_node);
1236         write_unlock(&dev_base_lock);
1237
1238         synchronize_rcu();
1239
1240         write_lock(&dev_base_lock);
1241         netdev_name_node_add(net, dev->name_node);
1242         write_unlock(&dev_base_lock);
1243
1244         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1245         ret = notifier_to_errno(ret);
1246
1247         if (ret) {
1248                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1249                 if (err >= 0) {
1250                         err = ret;
1251                         down_write(&devnet_rename_sem);
1252                         memcpy(dev->name, oldname, IFNAMSIZ);
1253                         memcpy(oldname, newname, IFNAMSIZ);
1254                         dev->name_assign_type = old_assign_type;
1255                         old_assign_type = NET_NAME_RENAMED;
1256                         goto rollback;
1257                 } else {
1258                         netdev_err(dev, "name change rollback failed: %d\n",
1259                                    ret);
1260                 }
1261         }
1262
1263         return err;
1264 }
1265
1266 /**
1267  *      dev_set_alias - change ifalias of a device
1268  *      @dev: device
1269  *      @alias: name up to IFALIASZ
1270  *      @len: limit of bytes to copy from info
1271  *
1272  *      Set ifalias for a device,
1273  */
1274 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1275 {
1276         struct dev_ifalias *new_alias = NULL;
1277
1278         if (len >= IFALIASZ)
1279                 return -EINVAL;
1280
1281         if (len) {
1282                 new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1283                 if (!new_alias)
1284                         return -ENOMEM;
1285
1286                 memcpy(new_alias->ifalias, alias, len);
1287                 new_alias->ifalias[len] = 0;
1288         }
1289
1290         mutex_lock(&ifalias_mutex);
1291         new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1292                                         mutex_is_locked(&ifalias_mutex));
1293         mutex_unlock(&ifalias_mutex);
1294
1295         if (new_alias)
1296                 kfree_rcu(new_alias, rcuhead);
1297
1298         return len;
1299 }
1300 EXPORT_SYMBOL(dev_set_alias);
1301
1302 /**
1303  *      dev_get_alias - get ifalias of a device
1304  *      @dev: device
1305  *      @name: buffer to store name of ifalias
1306  *      @len: size of buffer
1307  *
1308  *      get ifalias for a device.  Caller must make sure dev cannot go
1309  *      away,  e.g. rcu read lock or own a reference count to device.
1310  */
1311 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1312 {
1313         const struct dev_ifalias *alias;
1314         int ret = 0;
1315
1316         rcu_read_lock();
1317         alias = rcu_dereference(dev->ifalias);
1318         if (alias)
1319                 ret = snprintf(name, len, "%s", alias->ifalias);
1320         rcu_read_unlock();
1321
1322         return ret;
1323 }
1324
1325 /**
1326  *      netdev_features_change - device changes features
1327  *      @dev: device to cause notification
1328  *
1329  *      Called to indicate a device has changed features.
1330  */
1331 void netdev_features_change(struct net_device *dev)
1332 {
1333         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1334 }
1335 EXPORT_SYMBOL(netdev_features_change);
1336
1337 /**
1338  *      netdev_state_change - device changes state
1339  *      @dev: device to cause notification
1340  *
1341  *      Called to indicate a device has changed state. This function calls
1342  *      the notifier chains for netdev_chain and sends a NEWLINK message
1343  *      to the routing socket.
1344  */
1345 void netdev_state_change(struct net_device *dev)
1346 {
1347         if (dev->flags & IFF_UP) {
1348                 struct netdev_notifier_change_info change_info = {
1349                         .info.dev = dev,
1350                 };
1351
1352                 call_netdevice_notifiers_info(NETDEV_CHANGE,
1353                                               &change_info.info);
1354                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1355         }
1356 }
1357 EXPORT_SYMBOL(netdev_state_change);
1358
1359 /**
1360  * __netdev_notify_peers - notify network peers about existence of @dev,
1361  * to be called when rtnl lock is already held.
1362  * @dev: network device
1363  *
1364  * Generate traffic such that interested network peers are aware of
1365  * @dev, such as by generating a gratuitous ARP. This may be used when
1366  * a device wants to inform the rest of the network about some sort of
1367  * reconfiguration such as a failover event or virtual machine
1368  * migration.
1369  */
1370 void __netdev_notify_peers(struct net_device *dev)
1371 {
1372         ASSERT_RTNL();
1373         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1374         call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1375 }
1376 EXPORT_SYMBOL(__netdev_notify_peers);
1377
1378 /**
1379  * netdev_notify_peers - notify network peers about existence of @dev
1380  * @dev: network device
1381  *
1382  * Generate traffic such that interested network peers are aware of
1383  * @dev, such as by generating a gratuitous ARP. This may be used when
1384  * a device wants to inform the rest of the network about some sort of
1385  * reconfiguration such as a failover event or virtual machine
1386  * migration.
1387  */
1388 void netdev_notify_peers(struct net_device *dev)
1389 {
1390         rtnl_lock();
1391         __netdev_notify_peers(dev);
1392         rtnl_unlock();
1393 }
1394 EXPORT_SYMBOL(netdev_notify_peers);
1395
1396 static int napi_threaded_poll(void *data);
1397
1398 static int napi_kthread_create(struct napi_struct *n)
1399 {
1400         int err = 0;
1401
1402         /* Create and wake up the kthread once to put it in
1403          * TASK_INTERRUPTIBLE mode to avoid the blocked task
1404          * warning and work with loadavg.
1405          */
1406         n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1407                                 n->dev->name, n->napi_id);
1408         if (IS_ERR(n->thread)) {
1409                 err = PTR_ERR(n->thread);
1410                 pr_err("kthread_run failed with err %d\n", err);
1411                 n->thread = NULL;
1412         }
1413
1414         return err;
1415 }
1416
1417 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1418 {
1419         const struct net_device_ops *ops = dev->netdev_ops;
1420         int ret;
1421
1422         ASSERT_RTNL();
1423         dev_addr_check(dev);
1424
1425         if (!netif_device_present(dev)) {
1426                 /* may be detached because parent is runtime-suspended */
1427                 if (dev->dev.parent)
1428                         pm_runtime_resume(dev->dev.parent);
1429                 if (!netif_device_present(dev))
1430                         return -ENODEV;
1431         }
1432
1433         /* Block netpoll from trying to do any rx path servicing.
1434          * If we don't do this there is a chance ndo_poll_controller
1435          * or ndo_poll may be running while we open the device
1436          */
1437         netpoll_poll_disable(dev);
1438
1439         ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1440         ret = notifier_to_errno(ret);
1441         if (ret)
1442                 return ret;
1443
1444         set_bit(__LINK_STATE_START, &dev->state);
1445
1446         if (ops->ndo_validate_addr)
1447                 ret = ops->ndo_validate_addr(dev);
1448
1449         if (!ret && ops->ndo_open)
1450                 ret = ops->ndo_open(dev);
1451
1452         netpoll_poll_enable(dev);
1453
1454         if (ret)
1455                 clear_bit(__LINK_STATE_START, &dev->state);
1456         else {
1457                 dev->flags |= IFF_UP;
1458                 dev_set_rx_mode(dev);
1459                 dev_activate(dev);
1460                 add_device_randomness(dev->dev_addr, dev->addr_len);
1461         }
1462
1463         return ret;
1464 }
1465
1466 /**
1467  *      dev_open        - prepare an interface for use.
1468  *      @dev: device to open
1469  *      @extack: netlink extended ack
1470  *
1471  *      Takes a device from down to up state. The device's private open
1472  *      function is invoked and then the multicast lists are loaded. Finally
1473  *      the device is moved into the up state and a %NETDEV_UP message is
1474  *      sent to the netdev notifier chain.
1475  *
1476  *      Calling this function on an active interface is a nop. On a failure
1477  *      a negative errno code is returned.
1478  */
1479 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1480 {
1481         int ret;
1482
1483         if (dev->flags & IFF_UP)
1484                 return 0;
1485
1486         ret = __dev_open(dev, extack);
1487         if (ret < 0)
1488                 return ret;
1489
1490         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1491         call_netdevice_notifiers(NETDEV_UP, dev);
1492
1493         return ret;
1494 }
1495 EXPORT_SYMBOL(dev_open);
1496
1497 static void __dev_close_many(struct list_head *head)
1498 {
1499         struct net_device *dev;
1500
1501         ASSERT_RTNL();
1502         might_sleep();
1503
1504         list_for_each_entry(dev, head, close_list) {
1505                 /* Temporarily disable netpoll until the interface is down */
1506                 netpoll_poll_disable(dev);
1507
1508                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1509
1510                 clear_bit(__LINK_STATE_START, &dev->state);
1511
1512                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1513                  * can be even on different cpu. So just clear netif_running().
1514                  *
1515                  * dev->stop() will invoke napi_disable() on all of it's
1516                  * napi_struct instances on this device.
1517                  */
1518                 smp_mb__after_atomic(); /* Commit netif_running(). */
1519         }
1520
1521         dev_deactivate_many(head);
1522
1523         list_for_each_entry(dev, head, close_list) {
1524                 const struct net_device_ops *ops = dev->netdev_ops;
1525
1526                 /*
1527                  *      Call the device specific close. This cannot fail.
1528                  *      Only if device is UP
1529                  *
1530                  *      We allow it to be called even after a DETACH hot-plug
1531                  *      event.
1532                  */
1533                 if (ops->ndo_stop)
1534                         ops->ndo_stop(dev);
1535
1536                 dev->flags &= ~IFF_UP;
1537                 netpoll_poll_enable(dev);
1538         }
1539 }
1540
1541 static void __dev_close(struct net_device *dev)
1542 {
1543         LIST_HEAD(single);
1544
1545         list_add(&dev->close_list, &single);
1546         __dev_close_many(&single);
1547         list_del(&single);
1548 }
1549
1550 void dev_close_many(struct list_head *head, bool unlink)
1551 {
1552         struct net_device *dev, *tmp;
1553
1554         /* Remove the devices that don't need to be closed */
1555         list_for_each_entry_safe(dev, tmp, head, close_list)
1556                 if (!(dev->flags & IFF_UP))
1557                         list_del_init(&dev->close_list);
1558
1559         __dev_close_many(head);
1560
1561         list_for_each_entry_safe(dev, tmp, head, close_list) {
1562                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1563                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1564                 if (unlink)
1565                         list_del_init(&dev->close_list);
1566         }
1567 }
1568 EXPORT_SYMBOL(dev_close_many);
1569
1570 /**
1571  *      dev_close - shutdown an interface.
1572  *      @dev: device to shutdown
1573  *
1574  *      This function moves an active device into down state. A
1575  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1576  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1577  *      chain.
1578  */
1579 void dev_close(struct net_device *dev)
1580 {
1581         if (dev->flags & IFF_UP) {
1582                 LIST_HEAD(single);
1583
1584                 list_add(&dev->close_list, &single);
1585                 dev_close_many(&single, true);
1586                 list_del(&single);
1587         }
1588 }
1589 EXPORT_SYMBOL(dev_close);
1590
1591
1592 /**
1593  *      dev_disable_lro - disable Large Receive Offload on a device
1594  *      @dev: device
1595  *
1596  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1597  *      called under RTNL.  This is needed if received packets may be
1598  *      forwarded to another interface.
1599  */
1600 void dev_disable_lro(struct net_device *dev)
1601 {
1602         struct net_device *lower_dev;
1603         struct list_head *iter;
1604
1605         dev->wanted_features &= ~NETIF_F_LRO;
1606         netdev_update_features(dev);
1607
1608         if (unlikely(dev->features & NETIF_F_LRO))
1609                 netdev_WARN(dev, "failed to disable LRO!\n");
1610
1611         netdev_for_each_lower_dev(dev, lower_dev, iter)
1612                 dev_disable_lro(lower_dev);
1613 }
1614 EXPORT_SYMBOL(dev_disable_lro);
1615
1616 /**
1617  *      dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1618  *      @dev: device
1619  *
1620  *      Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1621  *      called under RTNL.  This is needed if Generic XDP is installed on
1622  *      the device.
1623  */
1624 static void dev_disable_gro_hw(struct net_device *dev)
1625 {
1626         dev->wanted_features &= ~NETIF_F_GRO_HW;
1627         netdev_update_features(dev);
1628
1629         if (unlikely(dev->features & NETIF_F_GRO_HW))
1630                 netdev_WARN(dev, "failed to disable GRO_HW!\n");
1631 }
1632
1633 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1634 {
1635 #define N(val)                                          \
1636         case NETDEV_##val:                              \
1637                 return "NETDEV_" __stringify(val);
1638         switch (cmd) {
1639         N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1640         N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1641         N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1642         N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1643         N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1644         N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1645         N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1646         N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1647         N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1648         N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1649         N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1650         N(XDP_FEAT_CHANGE)
1651         }
1652 #undef N
1653         return "UNKNOWN_NETDEV_EVENT";
1654 }
1655 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1656
1657 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1658                                    struct net_device *dev)
1659 {
1660         struct netdev_notifier_info info = {
1661                 .dev = dev,
1662         };
1663
1664         return nb->notifier_call(nb, val, &info);
1665 }
1666
1667 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1668                                              struct net_device *dev)
1669 {
1670         int err;
1671
1672         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1673         err = notifier_to_errno(err);
1674         if (err)
1675                 return err;
1676
1677         if (!(dev->flags & IFF_UP))
1678                 return 0;
1679
1680         call_netdevice_notifier(nb, NETDEV_UP, dev);
1681         return 0;
1682 }
1683
1684 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1685                                                 struct net_device *dev)
1686 {
1687         if (dev->flags & IFF_UP) {
1688                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1689                                         dev);
1690                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1691         }
1692         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1693 }
1694
1695 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1696                                                  struct net *net)
1697 {
1698         struct net_device *dev;
1699         int err;
1700
1701         for_each_netdev(net, dev) {
1702                 err = call_netdevice_register_notifiers(nb, dev);
1703                 if (err)
1704                         goto rollback;
1705         }
1706         return 0;
1707
1708 rollback:
1709         for_each_netdev_continue_reverse(net, dev)
1710                 call_netdevice_unregister_notifiers(nb, dev);
1711         return err;
1712 }
1713
1714 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1715                                                     struct net *net)
1716 {
1717         struct net_device *dev;
1718
1719         for_each_netdev(net, dev)
1720                 call_netdevice_unregister_notifiers(nb, dev);
1721 }
1722
1723 static int dev_boot_phase = 1;
1724
1725 /**
1726  * register_netdevice_notifier - register a network notifier block
1727  * @nb: notifier
1728  *
1729  * Register a notifier to be called when network device events occur.
1730  * The notifier passed is linked into the kernel structures and must
1731  * not be reused until it has been unregistered. A negative errno code
1732  * is returned on a failure.
1733  *
1734  * When registered all registration and up events are replayed
1735  * to the new notifier to allow device to have a race free
1736  * view of the network device list.
1737  */
1738
1739 int register_netdevice_notifier(struct notifier_block *nb)
1740 {
1741         struct net *net;
1742         int err;
1743
1744         /* Close race with setup_net() and cleanup_net() */
1745         down_write(&pernet_ops_rwsem);
1746         rtnl_lock();
1747         err = raw_notifier_chain_register(&netdev_chain, nb);
1748         if (err)
1749                 goto unlock;
1750         if (dev_boot_phase)
1751                 goto unlock;
1752         for_each_net(net) {
1753                 err = call_netdevice_register_net_notifiers(nb, net);
1754                 if (err)
1755                         goto rollback;
1756         }
1757
1758 unlock:
1759         rtnl_unlock();
1760         up_write(&pernet_ops_rwsem);
1761         return err;
1762
1763 rollback:
1764         for_each_net_continue_reverse(net)
1765                 call_netdevice_unregister_net_notifiers(nb, net);
1766
1767         raw_notifier_chain_unregister(&netdev_chain, nb);
1768         goto unlock;
1769 }
1770 EXPORT_SYMBOL(register_netdevice_notifier);
1771
1772 /**
1773  * unregister_netdevice_notifier - unregister a network notifier block
1774  * @nb: notifier
1775  *
1776  * Unregister a notifier previously registered by
1777  * register_netdevice_notifier(). The notifier is unlinked into the
1778  * kernel structures and may then be reused. A negative errno code
1779  * is returned on a failure.
1780  *
1781  * After unregistering unregister and down device events are synthesized
1782  * for all devices on the device list to the removed notifier to remove
1783  * the need for special case cleanup code.
1784  */
1785
1786 int unregister_netdevice_notifier(struct notifier_block *nb)
1787 {
1788         struct net *net;
1789         int err;
1790
1791         /* Close race with setup_net() and cleanup_net() */
1792         down_write(&pernet_ops_rwsem);
1793         rtnl_lock();
1794         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1795         if (err)
1796                 goto unlock;
1797
1798         for_each_net(net)
1799                 call_netdevice_unregister_net_notifiers(nb, net);
1800
1801 unlock:
1802         rtnl_unlock();
1803         up_write(&pernet_ops_rwsem);
1804         return err;
1805 }
1806 EXPORT_SYMBOL(unregister_netdevice_notifier);
1807
1808 static int __register_netdevice_notifier_net(struct net *net,
1809                                              struct notifier_block *nb,
1810                                              bool ignore_call_fail)
1811 {
1812         int err;
1813
1814         err = raw_notifier_chain_register(&net->netdev_chain, nb);
1815         if (err)
1816                 return err;
1817         if (dev_boot_phase)
1818                 return 0;
1819
1820         err = call_netdevice_register_net_notifiers(nb, net);
1821         if (err && !ignore_call_fail)
1822                 goto chain_unregister;
1823
1824         return 0;
1825
1826 chain_unregister:
1827         raw_notifier_chain_unregister(&net->netdev_chain, nb);
1828         return err;
1829 }
1830
1831 static int __unregister_netdevice_notifier_net(struct net *net,
1832                                                struct notifier_block *nb)
1833 {
1834         int err;
1835
1836         err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1837         if (err)
1838                 return err;
1839
1840         call_netdevice_unregister_net_notifiers(nb, net);
1841         return 0;
1842 }
1843
1844 /**
1845  * register_netdevice_notifier_net - register a per-netns network notifier block
1846  * @net: network namespace
1847  * @nb: notifier
1848  *
1849  * Register a notifier to be called when network device events occur.
1850  * The notifier passed is linked into the kernel structures and must
1851  * not be reused until it has been unregistered. A negative errno code
1852  * is returned on a failure.
1853  *
1854  * When registered all registration and up events are replayed
1855  * to the new notifier to allow device to have a race free
1856  * view of the network device list.
1857  */
1858
1859 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1860 {
1861         int err;
1862
1863         rtnl_lock();
1864         err = __register_netdevice_notifier_net(net, nb, false);
1865         rtnl_unlock();
1866         return err;
1867 }
1868 EXPORT_SYMBOL(register_netdevice_notifier_net);
1869
1870 /**
1871  * unregister_netdevice_notifier_net - unregister a per-netns
1872  *                                     network notifier block
1873  * @net: network namespace
1874  * @nb: notifier
1875  *
1876  * Unregister a notifier previously registered by
1877  * register_netdevice_notifier_net(). The notifier is unlinked from the
1878  * kernel structures and may then be reused. A negative errno code
1879  * is returned on a failure.
1880  *
1881  * After unregistering unregister and down device events are synthesized
1882  * for all devices on the device list to the removed notifier to remove
1883  * the need for special case cleanup code.
1884  */
1885
1886 int unregister_netdevice_notifier_net(struct net *net,
1887                                       struct notifier_block *nb)
1888 {
1889         int err;
1890
1891         rtnl_lock();
1892         err = __unregister_netdevice_notifier_net(net, nb);
1893         rtnl_unlock();
1894         return err;
1895 }
1896 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1897
1898 static void __move_netdevice_notifier_net(struct net *src_net,
1899                                           struct net *dst_net,
1900                                           struct notifier_block *nb)
1901 {
1902         __unregister_netdevice_notifier_net(src_net, nb);
1903         __register_netdevice_notifier_net(dst_net, nb, true);
1904 }
1905
1906 int register_netdevice_notifier_dev_net(struct net_device *dev,
1907                                         struct notifier_block *nb,
1908                                         struct netdev_net_notifier *nn)
1909 {
1910         int err;
1911
1912         rtnl_lock();
1913         err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1914         if (!err) {
1915                 nn->nb = nb;
1916                 list_add(&nn->list, &dev->net_notifier_list);
1917         }
1918         rtnl_unlock();
1919         return err;
1920 }
1921 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1922
1923 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1924                                           struct notifier_block *nb,
1925                                           struct netdev_net_notifier *nn)
1926 {
1927         int err;
1928
1929         rtnl_lock();
1930         list_del(&nn->list);
1931         err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1932         rtnl_unlock();
1933         return err;
1934 }
1935 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1936
1937 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1938                                              struct net *net)
1939 {
1940         struct netdev_net_notifier *nn;
1941
1942         list_for_each_entry(nn, &dev->net_notifier_list, list)
1943                 __move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1944 }
1945
1946 /**
1947  *      call_netdevice_notifiers_info - call all network notifier blocks
1948  *      @val: value passed unmodified to notifier function
1949  *      @info: notifier information data
1950  *
1951  *      Call all network notifier blocks.  Parameters and return value
1952  *      are as for raw_notifier_call_chain().
1953  */
1954
1955 int call_netdevice_notifiers_info(unsigned long val,
1956                                   struct netdev_notifier_info *info)
1957 {
1958         struct net *net = dev_net(info->dev);
1959         int ret;
1960
1961         ASSERT_RTNL();
1962
1963         /* Run per-netns notifier block chain first, then run the global one.
1964          * Hopefully, one day, the global one is going to be removed after
1965          * all notifier block registrators get converted to be per-netns.
1966          */
1967         ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1968         if (ret & NOTIFY_STOP_MASK)
1969                 return ret;
1970         return raw_notifier_call_chain(&netdev_chain, val, info);
1971 }
1972
1973 /**
1974  *      call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1975  *                                             for and rollback on error
1976  *      @val_up: value passed unmodified to notifier function
1977  *      @val_down: value passed unmodified to the notifier function when
1978  *                 recovering from an error on @val_up
1979  *      @info: notifier information data
1980  *
1981  *      Call all per-netns network notifier blocks, but not notifier blocks on
1982  *      the global notifier chain. Parameters and return value are as for
1983  *      raw_notifier_call_chain_robust().
1984  */
1985
1986 static int
1987 call_netdevice_notifiers_info_robust(unsigned long val_up,
1988                                      unsigned long val_down,
1989                                      struct netdev_notifier_info *info)
1990 {
1991         struct net *net = dev_net(info->dev);
1992
1993         ASSERT_RTNL();
1994
1995         return raw_notifier_call_chain_robust(&net->netdev_chain,
1996                                               val_up, val_down, info);
1997 }
1998
1999 static int call_netdevice_notifiers_extack(unsigned long val,
2000                                            struct net_device *dev,
2001                                            struct netlink_ext_ack *extack)
2002 {
2003         struct netdev_notifier_info info = {
2004                 .dev = dev,
2005                 .extack = extack,
2006         };
2007
2008         return call_netdevice_notifiers_info(val, &info);
2009 }
2010
2011 /**
2012  *      call_netdevice_notifiers - call all network notifier blocks
2013  *      @val: value passed unmodified to notifier function
2014  *      @dev: net_device pointer passed unmodified to notifier function
2015  *
2016  *      Call all network notifier blocks.  Parameters and return value
2017  *      are as for raw_notifier_call_chain().
2018  */
2019
2020 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
2021 {
2022         return call_netdevice_notifiers_extack(val, dev, NULL);
2023 }
2024 EXPORT_SYMBOL(call_netdevice_notifiers);
2025
2026 /**
2027  *      call_netdevice_notifiers_mtu - call all network notifier blocks
2028  *      @val: value passed unmodified to notifier function
2029  *      @dev: net_device pointer passed unmodified to notifier function
2030  *      @arg: additional u32 argument passed to the notifier function
2031  *
2032  *      Call all network notifier blocks.  Parameters and return value
2033  *      are as for raw_notifier_call_chain().
2034  */
2035 static int call_netdevice_notifiers_mtu(unsigned long val,
2036                                         struct net_device *dev, u32 arg)
2037 {
2038         struct netdev_notifier_info_ext info = {
2039                 .info.dev = dev,
2040                 .ext.mtu = arg,
2041         };
2042
2043         BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2044
2045         return call_netdevice_notifiers_info(val, &info.info);
2046 }
2047
2048 #ifdef CONFIG_NET_INGRESS
2049 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2050
2051 void net_inc_ingress_queue(void)
2052 {
2053         static_branch_inc(&ingress_needed_key);
2054 }
2055 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2056
2057 void net_dec_ingress_queue(void)
2058 {
2059         static_branch_dec(&ingress_needed_key);
2060 }
2061 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2062 #endif
2063
2064 #ifdef CONFIG_NET_EGRESS
2065 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2066
2067 void net_inc_egress_queue(void)
2068 {
2069         static_branch_inc(&egress_needed_key);
2070 }
2071 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2072
2073 void net_dec_egress_queue(void)
2074 {
2075         static_branch_dec(&egress_needed_key);
2076 }
2077 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2078 #endif
2079
2080 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2081 EXPORT_SYMBOL(netstamp_needed_key);
2082 #ifdef CONFIG_JUMP_LABEL
2083 static atomic_t netstamp_needed_deferred;
2084 static atomic_t netstamp_wanted;
2085 static void netstamp_clear(struct work_struct *work)
2086 {
2087         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2088         int wanted;
2089
2090         wanted = atomic_add_return(deferred, &netstamp_wanted);
2091         if (wanted > 0)
2092                 static_branch_enable(&netstamp_needed_key);
2093         else
2094                 static_branch_disable(&netstamp_needed_key);
2095 }
2096 static DECLARE_WORK(netstamp_work, netstamp_clear);
2097 #endif
2098
2099 void net_enable_timestamp(void)
2100 {
2101 #ifdef CONFIG_JUMP_LABEL
2102         int wanted = atomic_read(&netstamp_wanted);
2103
2104         while (wanted > 0) {
2105                 if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2106                         return;
2107         }
2108         atomic_inc(&netstamp_needed_deferred);
2109         schedule_work(&netstamp_work);
2110 #else
2111         static_branch_inc(&netstamp_needed_key);
2112 #endif
2113 }
2114 EXPORT_SYMBOL(net_enable_timestamp);
2115
2116 void net_disable_timestamp(void)
2117 {
2118 #ifdef CONFIG_JUMP_LABEL
2119         int wanted = atomic_read(&netstamp_wanted);
2120
2121         while (wanted > 1) {
2122                 if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2123                         return;
2124         }
2125         atomic_dec(&netstamp_needed_deferred);
2126         schedule_work(&netstamp_work);
2127 #else
2128         static_branch_dec(&netstamp_needed_key);
2129 #endif
2130 }
2131 EXPORT_SYMBOL(net_disable_timestamp);
2132
2133 static inline void net_timestamp_set(struct sk_buff *skb)
2134 {
2135         skb->tstamp = 0;
2136         skb->mono_delivery_time = 0;
2137         if (static_branch_unlikely(&netstamp_needed_key))
2138                 skb->tstamp = ktime_get_real();
2139 }
2140
2141 #define net_timestamp_check(COND, SKB)                          \
2142         if (static_branch_unlikely(&netstamp_needed_key)) {     \
2143                 if ((COND) && !(SKB)->tstamp)                   \
2144                         (SKB)->tstamp = ktime_get_real();       \
2145         }                                                       \
2146
2147 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2148 {
2149         return __is_skb_forwardable(dev, skb, true);
2150 }
2151 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2152
2153 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2154                               bool check_mtu)
2155 {
2156         int ret = ____dev_forward_skb(dev, skb, check_mtu);
2157
2158         if (likely(!ret)) {
2159                 skb->protocol = eth_type_trans(skb, dev);
2160                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2161         }
2162
2163         return ret;
2164 }
2165
2166 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2167 {
2168         return __dev_forward_skb2(dev, skb, true);
2169 }
2170 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2171
2172 /**
2173  * dev_forward_skb - loopback an skb to another netif
2174  *
2175  * @dev: destination network device
2176  * @skb: buffer to forward
2177  *
2178  * return values:
2179  *      NET_RX_SUCCESS  (no congestion)
2180  *      NET_RX_DROP     (packet was dropped, but freed)
2181  *
2182  * dev_forward_skb can be used for injecting an skb from the
2183  * start_xmit function of one device into the receive queue
2184  * of another device.
2185  *
2186  * The receiving device may be in another namespace, so
2187  * we have to clear all information in the skb that could
2188  * impact namespace isolation.
2189  */
2190 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2191 {
2192         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2193 }
2194 EXPORT_SYMBOL_GPL(dev_forward_skb);
2195
2196 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2197 {
2198         return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2199 }
2200
2201 static inline int deliver_skb(struct sk_buff *skb,
2202                               struct packet_type *pt_prev,
2203                               struct net_device *orig_dev)
2204 {
2205         if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2206                 return -ENOMEM;
2207         refcount_inc(&skb->users);
2208         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2209 }
2210
2211 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2212                                           struct packet_type **pt,
2213                                           struct net_device *orig_dev,
2214                                           __be16 type,
2215                                           struct list_head *ptype_list)
2216 {
2217         struct packet_type *ptype, *pt_prev = *pt;
2218
2219         list_for_each_entry_rcu(ptype, ptype_list, list) {
2220                 if (ptype->type != type)
2221                         continue;
2222                 if (pt_prev)
2223                         deliver_skb(skb, pt_prev, orig_dev);
2224                 pt_prev = ptype;
2225         }
2226         *pt = pt_prev;
2227 }
2228
2229 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2230 {
2231         if (!ptype->af_packet_priv || !skb->sk)
2232                 return false;
2233
2234         if (ptype->id_match)
2235                 return ptype->id_match(ptype, skb->sk);
2236         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2237                 return true;
2238
2239         return false;
2240 }
2241
2242 /**
2243  * dev_nit_active - return true if any network interface taps are in use
2244  *
2245  * @dev: network device to check for the presence of taps
2246  */
2247 bool dev_nit_active(struct net_device *dev)
2248 {
2249         return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2250 }
2251 EXPORT_SYMBOL_GPL(dev_nit_active);
2252
2253 /*
2254  *      Support routine. Sends outgoing frames to any network
2255  *      taps currently in use.
2256  */
2257
2258 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2259 {
2260         struct packet_type *ptype;
2261         struct sk_buff *skb2 = NULL;
2262         struct packet_type *pt_prev = NULL;
2263         struct list_head *ptype_list = &ptype_all;
2264
2265         rcu_read_lock();
2266 again:
2267         list_for_each_entry_rcu(ptype, ptype_list, list) {
2268                 if (ptype->ignore_outgoing)
2269                         continue;
2270
2271                 /* Never send packets back to the socket
2272                  * they originated from - MvS (miquels@drinkel.ow.org)
2273                  */
2274                 if (skb_loop_sk(ptype, skb))
2275                         continue;
2276
2277                 if (pt_prev) {
2278                         deliver_skb(skb2, pt_prev, skb->dev);
2279                         pt_prev = ptype;
2280                         continue;
2281                 }
2282
2283                 /* need to clone skb, done only once */
2284                 skb2 = skb_clone(skb, GFP_ATOMIC);
2285                 if (!skb2)
2286                         goto out_unlock;
2287
2288                 net_timestamp_set(skb2);
2289
2290                 /* skb->nh should be correctly
2291                  * set by sender, so that the second statement is
2292                  * just protection against buggy protocols.
2293                  */
2294                 skb_reset_mac_header(skb2);
2295
2296                 if (skb_network_header(skb2) < skb2->data ||
2297                     skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2298                         net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2299                                              ntohs(skb2->protocol),
2300                                              dev->name);
2301                         skb_reset_network_header(skb2);
2302                 }
2303
2304                 skb2->transport_header = skb2->network_header;
2305                 skb2->pkt_type = PACKET_OUTGOING;
2306                 pt_prev = ptype;
2307         }
2308
2309         if (ptype_list == &ptype_all) {
2310                 ptype_list = &dev->ptype_all;
2311                 goto again;
2312         }
2313 out_unlock:
2314         if (pt_prev) {
2315                 if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2316                         pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2317                 else
2318                         kfree_skb(skb2);
2319         }
2320         rcu_read_unlock();
2321 }
2322 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2323
2324 /**
2325  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2326  * @dev: Network device
2327  * @txq: number of queues available
2328  *
2329  * If real_num_tx_queues is changed the tc mappings may no longer be
2330  * valid. To resolve this verify the tc mapping remains valid and if
2331  * not NULL the mapping. With no priorities mapping to this
2332  * offset/count pair it will no longer be used. In the worst case TC0
2333  * is invalid nothing can be done so disable priority mappings. If is
2334  * expected that drivers will fix this mapping if they can before
2335  * calling netif_set_real_num_tx_queues.
2336  */
2337 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2338 {
2339         int i;
2340         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2341
2342         /* If TC0 is invalidated disable TC mapping */
2343         if (tc->offset + tc->count > txq) {
2344                 netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2345                 dev->num_tc = 0;
2346                 return;
2347         }
2348
2349         /* Invalidated prio to tc mappings set to TC0 */
2350         for (i = 1; i < TC_BITMASK + 1; i++) {
2351                 int q = netdev_get_prio_tc_map(dev, i);
2352
2353                 tc = &dev->tc_to_txq[q];
2354                 if (tc->offset + tc->count > txq) {
2355                         netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2356                                     i, q);
2357                         netdev_set_prio_tc_map(dev, i, 0);
2358                 }
2359         }
2360 }
2361
2362 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2363 {
2364         if (dev->num_tc) {
2365                 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2366                 int i;
2367
2368                 /* walk through the TCs and see if it falls into any of them */
2369                 for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2370                         if ((txq - tc->offset) < tc->count)
2371                                 return i;
2372                 }
2373
2374                 /* didn't find it, just return -1 to indicate no match */
2375                 return -1;
2376         }
2377
2378         return 0;
2379 }
2380 EXPORT_SYMBOL(netdev_txq_to_tc);
2381
2382 #ifdef CONFIG_XPS
2383 static struct static_key xps_needed __read_mostly;
2384 static struct static_key xps_rxqs_needed __read_mostly;
2385 static DEFINE_MUTEX(xps_map_mutex);
2386 #define xmap_dereference(P)             \
2387         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2388
2389 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2390                              struct xps_dev_maps *old_maps, int tci, u16 index)
2391 {
2392         struct xps_map *map = NULL;
2393         int pos;
2394
2395         map = xmap_dereference(dev_maps->attr_map[tci]);
2396         if (!map)
2397                 return false;
2398
2399         for (pos = map->len; pos--;) {
2400                 if (map->queues[pos] != index)
2401                         continue;
2402
2403                 if (map->len > 1) {
2404                         map->queues[pos] = map->queues[--map->len];
2405                         break;
2406                 }
2407
2408                 if (old_maps)
2409                         RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2410                 RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2411                 kfree_rcu(map, rcu);
2412                 return false;
2413         }
2414
2415         return true;
2416 }
2417
2418 static bool remove_xps_queue_cpu(struct net_device *dev,
2419                                  struct xps_dev_maps *dev_maps,
2420                                  int cpu, u16 offset, u16 count)
2421 {
2422         int num_tc = dev_maps->num_tc;
2423         bool active = false;
2424         int tci;
2425
2426         for (tci = cpu * num_tc; num_tc--; tci++) {
2427                 int i, j;
2428
2429                 for (i = count, j = offset; i--; j++) {
2430                         if (!remove_xps_queue(dev_maps, NULL, tci, j))
2431                                 break;
2432                 }
2433
2434                 active |= i < 0;
2435         }
2436
2437         return active;
2438 }
2439
2440 static void reset_xps_maps(struct net_device *dev,
2441                            struct xps_dev_maps *dev_maps,
2442                            enum xps_map_type type)
2443 {
2444         static_key_slow_dec_cpuslocked(&xps_needed);
2445         if (type == XPS_RXQS)
2446                 static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2447
2448         RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2449
2450         kfree_rcu(dev_maps, rcu);
2451 }
2452
2453 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2454                            u16 offset, u16 count)
2455 {
2456         struct xps_dev_maps *dev_maps;
2457         bool active = false;
2458         int i, j;
2459
2460         dev_maps = xmap_dereference(dev->xps_maps[type]);
2461         if (!dev_maps)
2462                 return;
2463
2464         for (j = 0; j < dev_maps->nr_ids; j++)
2465                 active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2466         if (!active)
2467                 reset_xps_maps(dev, dev_maps, type);
2468
2469         if (type == XPS_CPUS) {
2470                 for (i = offset + (count - 1); count--; i--)
2471                         netdev_queue_numa_node_write(
2472                                 netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2473         }
2474 }
2475
2476 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2477                                    u16 count)
2478 {
2479         if (!static_key_false(&xps_needed))
2480                 return;
2481
2482         cpus_read_lock();
2483         mutex_lock(&xps_map_mutex);
2484
2485         if (static_key_false(&xps_rxqs_needed))
2486                 clean_xps_maps(dev, XPS_RXQS, offset, count);
2487
2488         clean_xps_maps(dev, XPS_CPUS, offset, count);
2489
2490         mutex_unlock(&xps_map_mutex);
2491         cpus_read_unlock();
2492 }
2493
2494 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2495 {
2496         netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2497 }
2498
2499 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2500                                       u16 index, bool is_rxqs_map)
2501 {
2502         struct xps_map *new_map;
2503         int alloc_len = XPS_MIN_MAP_ALLOC;
2504         int i, pos;
2505
2506         for (pos = 0; map && pos < map->len; pos++) {
2507                 if (map->queues[pos] != index)
2508                         continue;
2509                 return map;
2510         }
2511
2512         /* Need to add tx-queue to this CPU's/rx-queue's existing map */
2513         if (map) {
2514                 if (pos < map->alloc_len)
2515                         return map;
2516
2517                 alloc_len = map->alloc_len * 2;
2518         }
2519
2520         /* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2521          *  map
2522          */
2523         if (is_rxqs_map)
2524                 new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2525         else
2526                 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2527                                        cpu_to_node(attr_index));
2528         if (!new_map)
2529                 return NULL;
2530
2531         for (i = 0; i < pos; i++)
2532                 new_map->queues[i] = map->queues[i];
2533         new_map->alloc_len = alloc_len;
2534         new_map->len = pos;
2535
2536         return new_map;
2537 }
2538
2539 /* Copy xps maps at a given index */
2540 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2541                               struct xps_dev_maps *new_dev_maps, int index,
2542                               int tc, bool skip_tc)
2543 {
2544         int i, tci = index * dev_maps->num_tc;
2545         struct xps_map *map;
2546
2547         /* copy maps belonging to foreign traffic classes */
2548         for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2549                 if (i == tc && skip_tc)
2550                         continue;
2551
2552                 /* fill in the new device map from the old device map */
2553                 map = xmap_dereference(dev_maps->attr_map[tci]);
2554                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2555         }
2556 }
2557
2558 /* Must be called under cpus_read_lock */
2559 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2560                           u16 index, enum xps_map_type type)
2561 {
2562         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2563         const unsigned long *online_mask = NULL;
2564         bool active = false, copy = false;
2565         int i, j, tci, numa_node_id = -2;
2566         int maps_sz, num_tc = 1, tc = 0;
2567         struct xps_map *map, *new_map;
2568         unsigned int nr_ids;
2569
2570         WARN_ON_ONCE(index >= dev->num_tx_queues);
2571
2572         if (dev->num_tc) {
2573                 /* Do not allow XPS on subordinate device directly */
2574                 num_tc = dev->num_tc;
2575                 if (num_tc < 0)
2576                         return -EINVAL;
2577
2578                 /* If queue belongs to subordinate dev use its map */
2579                 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2580
2581                 tc = netdev_txq_to_tc(dev, index);
2582                 if (tc < 0)
2583                         return -EINVAL;
2584         }
2585
2586         mutex_lock(&xps_map_mutex);
2587
2588         dev_maps = xmap_dereference(dev->xps_maps[type]);
2589         if (type == XPS_RXQS) {
2590                 maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2591                 nr_ids = dev->num_rx_queues;
2592         } else {
2593                 maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2594                 if (num_possible_cpus() > 1)
2595                         online_mask = cpumask_bits(cpu_online_mask);
2596                 nr_ids = nr_cpu_ids;
2597         }
2598
2599         if (maps_sz < L1_CACHE_BYTES)
2600                 maps_sz = L1_CACHE_BYTES;
2601
2602         /* The old dev_maps could be larger or smaller than the one we're
2603          * setting up now, as dev->num_tc or nr_ids could have been updated in
2604          * between. We could try to be smart, but let's be safe instead and only
2605          * copy foreign traffic classes if the two map sizes match.
2606          */
2607         if (dev_maps &&
2608             dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2609                 copy = true;
2610
2611         /* allocate memory for queue storage */
2612         for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2613              j < nr_ids;) {
2614                 if (!new_dev_maps) {
2615                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2616                         if (!new_dev_maps) {
2617                                 mutex_unlock(&xps_map_mutex);
2618                                 return -ENOMEM;
2619                         }
2620
2621                         new_dev_maps->nr_ids = nr_ids;
2622                         new_dev_maps->num_tc = num_tc;
2623                 }
2624
2625                 tci = j * num_tc + tc;
2626                 map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2627
2628                 map = expand_xps_map(map, j, index, type == XPS_RXQS);
2629                 if (!map)
2630                         goto error;
2631
2632                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2633         }
2634
2635         if (!new_dev_maps)
2636                 goto out_no_new_maps;
2637
2638         if (!dev_maps) {
2639                 /* Increment static keys at most once per type */
2640                 static_key_slow_inc_cpuslocked(&xps_needed);
2641                 if (type == XPS_RXQS)
2642                         static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2643         }
2644
2645         for (j = 0; j < nr_ids; j++) {
2646                 bool skip_tc = false;
2647
2648                 tci = j * num_tc + tc;
2649                 if (netif_attr_test_mask(j, mask, nr_ids) &&
2650                     netif_attr_test_online(j, online_mask, nr_ids)) {
2651                         /* add tx-queue to CPU/rx-queue maps */
2652                         int pos = 0;
2653
2654                         skip_tc = true;
2655
2656                         map = xmap_dereference(new_dev_maps->attr_map[tci]);
2657                         while ((pos < map->len) && (map->queues[pos] != index))
2658                                 pos++;
2659
2660                         if (pos == map->len)
2661                                 map->queues[map->len++] = index;
2662 #ifdef CONFIG_NUMA
2663                         if (type == XPS_CPUS) {
2664                                 if (numa_node_id == -2)
2665                                         numa_node_id = cpu_to_node(j);
2666                                 else if (numa_node_id != cpu_to_node(j))
2667                                         numa_node_id = -1;
2668                         }
2669 #endif
2670                 }
2671
2672                 if (copy)
2673                         xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2674                                           skip_tc);
2675         }
2676
2677         rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2678
2679         /* Cleanup old maps */
2680         if (!dev_maps)
2681                 goto out_no_old_maps;
2682
2683         for (j = 0; j < dev_maps->nr_ids; j++) {
2684                 for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2685                         map = xmap_dereference(dev_maps->attr_map[tci]);
2686                         if (!map)
2687                                 continue;
2688
2689                         if (copy) {
2690                                 new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2691                                 if (map == new_map)
2692                                         continue;
2693                         }
2694
2695                         RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2696                         kfree_rcu(map, rcu);
2697                 }
2698         }
2699
2700         old_dev_maps = dev_maps;
2701
2702 out_no_old_maps:
2703         dev_maps = new_dev_maps;
2704         active = true;
2705
2706 out_no_new_maps:
2707         if (type == XPS_CPUS)
2708                 /* update Tx queue numa node */
2709                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2710                                              (numa_node_id >= 0) ?
2711                                              numa_node_id : NUMA_NO_NODE);
2712
2713         if (!dev_maps)
2714                 goto out_no_maps;
2715
2716         /* removes tx-queue from unused CPUs/rx-queues */
2717         for (j = 0; j < dev_maps->nr_ids; j++) {
2718                 tci = j * dev_maps->num_tc;
2719
2720                 for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2721                         if (i == tc &&
2722                             netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2723                             netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2724                                 continue;
2725
2726                         active |= remove_xps_queue(dev_maps,
2727                                                    copy ? old_dev_maps : NULL,
2728                                                    tci, index);
2729                 }
2730         }
2731
2732         if (old_dev_maps)
2733                 kfree_rcu(old_dev_maps, rcu);
2734
2735         /* free map if not active */
2736         if (!active)
2737                 reset_xps_maps(dev, dev_maps, type);
2738
2739 out_no_maps:
2740         mutex_unlock(&xps_map_mutex);
2741
2742         return 0;
2743 error:
2744         /* remove any maps that we added */
2745         for (j = 0; j < nr_ids; j++) {
2746                 for (i = num_tc, tci = j * num_tc; i--; tci++) {
2747                         new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2748                         map = copy ?
2749                               xmap_dereference(dev_maps->attr_map[tci]) :
2750                               NULL;
2751                         if (new_map && new_map != map)
2752                                 kfree(new_map);
2753                 }
2754         }
2755
2756         mutex_unlock(&xps_map_mutex);
2757
2758         kfree(new_dev_maps);
2759         return -ENOMEM;
2760 }
2761 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2762
2763 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2764                         u16 index)
2765 {
2766         int ret;
2767
2768         cpus_read_lock();
2769         ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2770         cpus_read_unlock();
2771
2772         return ret;
2773 }
2774 EXPORT_SYMBOL(netif_set_xps_queue);
2775
2776 #endif
2777 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2778 {
2779         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2780
2781         /* Unbind any subordinate channels */
2782         while (txq-- != &dev->_tx[0]) {
2783                 if (txq->sb_dev)
2784                         netdev_unbind_sb_channel(dev, txq->sb_dev);
2785         }
2786 }
2787
2788 void netdev_reset_tc(struct net_device *dev)
2789 {
2790 #ifdef CONFIG_XPS
2791         netif_reset_xps_queues_gt(dev, 0);
2792 #endif
2793         netdev_unbind_all_sb_channels(dev);
2794
2795         /* Reset TC configuration of device */
2796         dev->num_tc = 0;
2797         memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2798         memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2799 }
2800 EXPORT_SYMBOL(netdev_reset_tc);
2801
2802 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2803 {
2804         if (tc >= dev->num_tc)
2805                 return -EINVAL;
2806
2807 #ifdef CONFIG_XPS
2808         netif_reset_xps_queues(dev, offset, count);
2809 #endif
2810         dev->tc_to_txq[tc].count = count;
2811         dev->tc_to_txq[tc].offset = offset;
2812         return 0;
2813 }
2814 EXPORT_SYMBOL(netdev_set_tc_queue);
2815
2816 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2817 {
2818         if (num_tc > TC_MAX_QUEUE)
2819                 return -EINVAL;
2820
2821 #ifdef CONFIG_XPS
2822         netif_reset_xps_queues_gt(dev, 0);
2823 #endif
2824         netdev_unbind_all_sb_channels(dev);
2825
2826         dev->num_tc = num_tc;
2827         return 0;
2828 }
2829 EXPORT_SYMBOL(netdev_set_num_tc);
2830
2831 void netdev_unbind_sb_channel(struct net_device *dev,
2832                               struct net_device *sb_dev)
2833 {
2834         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2835
2836 #ifdef CONFIG_XPS
2837         netif_reset_xps_queues_gt(sb_dev, 0);
2838 #endif
2839         memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2840         memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2841
2842         while (txq-- != &dev->_tx[0]) {
2843                 if (txq->sb_dev == sb_dev)
2844                         txq->sb_dev = NULL;
2845         }
2846 }
2847 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2848
2849 int netdev_bind_sb_channel_queue(struct net_device *dev,
2850                                  struct net_device *sb_dev,
2851                                  u8 tc, u16 count, u16 offset)
2852 {
2853         /* Make certain the sb_dev and dev are already configured */
2854         if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2855                 return -EINVAL;
2856
2857         /* We cannot hand out queues we don't have */
2858         if ((offset + count) > dev->real_num_tx_queues)
2859                 return -EINVAL;
2860
2861         /* Record the mapping */
2862         sb_dev->tc_to_txq[tc].count = count;
2863         sb_dev->tc_to_txq[tc].offset = offset;
2864
2865         /* Provide a way for Tx queue to find the tc_to_txq map or
2866          * XPS map for itself.
2867          */
2868         while (count--)
2869                 netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2870
2871         return 0;
2872 }
2873 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2874
2875 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2876 {
2877         /* Do not use a multiqueue device to represent a subordinate channel */
2878         if (netif_is_multiqueue(dev))
2879                 return -ENODEV;
2880
2881         /* We allow channels 1 - 32767 to be used for subordinate channels.
2882          * Channel 0 is meant to be "native" mode and used only to represent
2883          * the main root device. We allow writing 0 to reset the device back
2884          * to normal mode after being used as a subordinate channel.
2885          */
2886         if (channel > S16_MAX)
2887                 return -EINVAL;
2888
2889         dev->num_tc = -channel;
2890
2891         return 0;
2892 }
2893 EXPORT_SYMBOL(netdev_set_sb_channel);
2894
2895 /*
2896  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2897  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2898  */
2899 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2900 {
2901         bool disabling;
2902         int rc;
2903
2904         disabling = txq < dev->real_num_tx_queues;
2905
2906         if (txq < 1 || txq > dev->num_tx_queues)
2907                 return -EINVAL;
2908
2909         if (dev->reg_state == NETREG_REGISTERED ||
2910             dev->reg_state == NETREG_UNREGISTERING) {
2911                 ASSERT_RTNL();
2912
2913                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2914                                                   txq);
2915                 if (rc)
2916                         return rc;
2917
2918                 if (dev->num_tc)
2919                         netif_setup_tc(dev, txq);
2920
2921                 dev_qdisc_change_real_num_tx(dev, txq);
2922
2923                 dev->real_num_tx_queues = txq;
2924
2925                 if (disabling) {
2926                         synchronize_net();
2927                         qdisc_reset_all_tx_gt(dev, txq);
2928 #ifdef CONFIG_XPS
2929                         netif_reset_xps_queues_gt(dev, txq);
2930 #endif
2931                 }
2932         } else {
2933                 dev->real_num_tx_queues = txq;
2934         }
2935
2936         return 0;
2937 }
2938 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2939
2940 #ifdef CONFIG_SYSFS
2941 /**
2942  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2943  *      @dev: Network device
2944  *      @rxq: Actual number of RX queues
2945  *
2946  *      This must be called either with the rtnl_lock held or before
2947  *      registration of the net device.  Returns 0 on success, or a
2948  *      negative error code.  If called before registration, it always
2949  *      succeeds.
2950  */
2951 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2952 {
2953         int rc;
2954
2955         if (rxq < 1 || rxq > dev->num_rx_queues)
2956                 return -EINVAL;
2957
2958         if (dev->reg_state == NETREG_REGISTERED) {
2959                 ASSERT_RTNL();
2960
2961                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2962                                                   rxq);
2963                 if (rc)
2964                         return rc;
2965         }
2966
2967         dev->real_num_rx_queues = rxq;
2968         return 0;
2969 }
2970 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2971 #endif
2972
2973 /**
2974  *      netif_set_real_num_queues - set actual number of RX and TX queues used
2975  *      @dev: Network device
2976  *      @txq: Actual number of TX queues
2977  *      @rxq: Actual number of RX queues
2978  *
2979  *      Set the real number of both TX and RX queues.
2980  *      Does nothing if the number of queues is already correct.
2981  */
2982 int netif_set_real_num_queues(struct net_device *dev,
2983                               unsigned int txq, unsigned int rxq)
2984 {
2985         unsigned int old_rxq = dev->real_num_rx_queues;
2986         int err;
2987
2988         if (txq < 1 || txq > dev->num_tx_queues ||
2989             rxq < 1 || rxq > dev->num_rx_queues)
2990                 return -EINVAL;
2991
2992         /* Start from increases, so the error path only does decreases -
2993          * decreases can't fail.
2994          */
2995         if (rxq > dev->real_num_rx_queues) {
2996                 err = netif_set_real_num_rx_queues(dev, rxq);
2997                 if (err)
2998                         return err;
2999         }
3000         if (txq > dev->real_num_tx_queues) {
3001                 err = netif_set_real_num_tx_queues(dev, txq);
3002                 if (err)
3003                         goto undo_rx;
3004         }
3005         if (rxq < dev->real_num_rx_queues)
3006                 WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
3007         if (txq < dev->real_num_tx_queues)
3008                 WARN_ON(netif_set_real_num_tx_queues(dev, txq));
3009
3010         return 0;
3011 undo_rx:
3012         WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
3013         return err;
3014 }
3015 EXPORT_SYMBOL(netif_set_real_num_queues);
3016
3017 /**
3018  * netif_set_tso_max_size() - set the max size of TSO frames supported
3019  * @dev:        netdev to update
3020  * @size:       max skb->len of a TSO frame
3021  *
3022  * Set the limit on the size of TSO super-frames the device can handle.
3023  * Unless explicitly set the stack will assume the value of
3024  * %GSO_LEGACY_MAX_SIZE.
3025  */
3026 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3027 {
3028         dev->tso_max_size = min(GSO_MAX_SIZE, size);
3029         if (size < READ_ONCE(dev->gso_max_size))
3030                 netif_set_gso_max_size(dev, size);
3031         if (size < READ_ONCE(dev->gso_ipv4_max_size))
3032                 netif_set_gso_ipv4_max_size(dev, size);
3033 }
3034 EXPORT_SYMBOL(netif_set_tso_max_size);
3035
3036 /**
3037  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3038  * @dev:        netdev to update
3039  * @segs:       max number of TCP segments
3040  *
3041  * Set the limit on the number of TCP segments the device can generate from
3042  * a single TSO super-frame.
3043  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3044  */
3045 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3046 {
3047         dev->tso_max_segs = segs;
3048         if (segs < READ_ONCE(dev->gso_max_segs))
3049                 netif_set_gso_max_segs(dev, segs);
3050 }
3051 EXPORT_SYMBOL(netif_set_tso_max_segs);
3052
3053 /**
3054  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3055  * @to:         netdev to update
3056  * @from:       netdev from which to copy the limits
3057  */
3058 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3059 {
3060         netif_set_tso_max_size(to, from->tso_max_size);
3061         netif_set_tso_max_segs(to, from->tso_max_segs);
3062 }
3063 EXPORT_SYMBOL(netif_inherit_tso_max);
3064
3065 /**
3066  * netif_get_num_default_rss_queues - default number of RSS queues
3067  *
3068  * Default value is the number of physical cores if there are only 1 or 2, or
3069  * divided by 2 if there are more.
3070  */
3071 int netif_get_num_default_rss_queues(void)
3072 {
3073         cpumask_var_t cpus;
3074         int cpu, count = 0;
3075
3076         if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3077                 return 1;
3078
3079         cpumask_copy(cpus, cpu_online_mask);
3080         for_each_cpu(cpu, cpus) {
3081                 ++count;
3082                 cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3083         }
3084         free_cpumask_var(cpus);
3085
3086         return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3087 }
3088 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3089
3090 static void __netif_reschedule(struct Qdisc *q)
3091 {
3092         struct softnet_data *sd;
3093         unsigned long flags;
3094
3095         local_irq_save(flags);
3096         sd = this_cpu_ptr(&softnet_data);
3097         q->next_sched = NULL;
3098         *sd->output_queue_tailp = q;
3099         sd->output_queue_tailp = &q->next_sched;
3100         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3101         local_irq_restore(flags);
3102 }
3103
3104 void __netif_schedule(struct Qdisc *q)
3105 {
3106         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3107                 __netif_reschedule(q);
3108 }
3109 EXPORT_SYMBOL(__netif_schedule);
3110
3111 struct dev_kfree_skb_cb {
3112         enum skb_drop_reason reason;
3113 };
3114
3115 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3116 {
3117         return (struct dev_kfree_skb_cb *)skb->cb;
3118 }
3119
3120 void netif_schedule_queue(struct netdev_queue *txq)
3121 {
3122         rcu_read_lock();
3123         if (!netif_xmit_stopped(txq)) {
3124                 struct Qdisc *q = rcu_dereference(txq->qdisc);
3125
3126                 __netif_schedule(q);
3127         }
3128         rcu_read_unlock();
3129 }
3130 EXPORT_SYMBOL(netif_schedule_queue);
3131
3132 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3133 {
3134         if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3135                 struct Qdisc *q;
3136
3137                 rcu_read_lock();
3138                 q = rcu_dereference(dev_queue->qdisc);
3139                 __netif_schedule(q);
3140                 rcu_read_unlock();
3141         }
3142 }
3143 EXPORT_SYMBOL(netif_tx_wake_queue);
3144
3145 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3146 {
3147         unsigned long flags;
3148
3149         if (unlikely(!skb))
3150                 return;
3151
3152         if (likely(refcount_read(&skb->users) == 1)) {
3153                 smp_rmb();
3154                 refcount_set(&skb->users, 0);
3155         } else if (likely(!refcount_dec_and_test(&skb->users))) {
3156                 return;
3157         }
3158         get_kfree_skb_cb(skb)->reason = reason;
3159         local_irq_save(flags);
3160         skb->next = __this_cpu_read(softnet_data.completion_queue);
3161         __this_cpu_write(softnet_data.completion_queue, skb);
3162         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3163         local_irq_restore(flags);
3164 }
3165 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3166
3167 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3168 {
3169         if (in_hardirq() || irqs_disabled())
3170                 dev_kfree_skb_irq_reason(skb, reason);
3171         else
3172                 kfree_skb_reason(skb, reason);
3173 }
3174 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3175
3176
3177 /**
3178  * netif_device_detach - mark device as removed
3179  * @dev: network device
3180  *
3181  * Mark device as removed from system and therefore no longer available.
3182  */
3183 void netif_device_detach(struct net_device *dev)
3184 {
3185         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3186             netif_running(dev)) {
3187                 netif_tx_stop_all_queues(dev);
3188         }
3189 }
3190 EXPORT_SYMBOL(netif_device_detach);
3191
3192 /**
3193  * netif_device_attach - mark device as attached
3194  * @dev: network device
3195  *
3196  * Mark device as attached from system and restart if needed.
3197  */
3198 void netif_device_attach(struct net_device *dev)
3199 {
3200         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3201             netif_running(dev)) {
3202                 netif_tx_wake_all_queues(dev);
3203                 __netdev_watchdog_up(dev);
3204         }
3205 }
3206 EXPORT_SYMBOL(netif_device_attach);
3207
3208 /*
3209  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3210  * to be used as a distribution range.
3211  */
3212 static u16 skb_tx_hash(const struct net_device *dev,
3213                        const struct net_device *sb_dev,
3214                        struct sk_buff *skb)
3215 {
3216         u32 hash;
3217         u16 qoffset = 0;
3218         u16 qcount = dev->real_num_tx_queues;
3219
3220         if (dev->num_tc) {
3221                 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3222
3223                 qoffset = sb_dev->tc_to_txq[tc].offset;
3224                 qcount = sb_dev->tc_to_txq[tc].count;
3225                 if (unlikely(!qcount)) {
3226                         net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3227                                              sb_dev->name, qoffset, tc);
3228                         qoffset = 0;
3229                         qcount = dev->real_num_tx_queues;
3230                 }
3231         }
3232
3233         if (skb_rx_queue_recorded(skb)) {
3234                 DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3235                 hash = skb_get_rx_queue(skb);
3236                 if (hash >= qoffset)
3237                         hash -= qoffset;
3238                 while (unlikely(hash >= qcount))
3239                         hash -= qcount;
3240                 return hash + qoffset;
3241         }
3242
3243         return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3244 }
3245
3246 void skb_warn_bad_offload(const struct sk_buff *skb)
3247 {
3248         static const netdev_features_t null_features;
3249         struct net_device *dev = skb->dev;
3250         const char *name = "";
3251
3252         if (!net_ratelimit())
3253                 return;
3254
3255         if (dev) {
3256                 if (dev->dev.parent)
3257                         name = dev_driver_string(dev->dev.parent);
3258                 else
3259                         name = netdev_name(dev);
3260         }
3261         skb_dump(KERN_WARNING, skb, false);
3262         WARN(1, "%s: caps=(%pNF, %pNF)\n",
3263              name, dev ? &dev->features : &null_features,
3264              skb->sk ? &skb->sk->sk_route_caps : &null_features);
3265 }
3266
3267 /*
3268  * Invalidate hardware checksum when packet is to be mangled, and
3269  * complete checksum manually on outgoing path.
3270  */
3271 int skb_checksum_help(struct sk_buff *skb)
3272 {
3273         __wsum csum;
3274         int ret = 0, offset;
3275
3276         if (skb->ip_summed == CHECKSUM_COMPLETE)
3277                 goto out_set_summed;
3278
3279         if (unlikely(skb_is_gso(skb))) {
3280                 skb_warn_bad_offload(skb);
3281                 return -EINVAL;
3282         }
3283
3284         /* Before computing a checksum, we should make sure no frag could
3285          * be modified by an external entity : checksum could be wrong.
3286          */
3287         if (skb_has_shared_frag(skb)) {
3288                 ret = __skb_linearize(skb);
3289                 if (ret)
3290                         goto out;
3291         }
3292
3293         offset = skb_checksum_start_offset(skb);
3294         ret = -EINVAL;
3295         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3296                 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3297                 goto out;
3298         }
3299         csum = skb_checksum(skb, offset, skb->len - offset, 0);
3300
3301         offset += skb->csum_offset;
3302         if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3303                 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3304                 goto out;
3305         }
3306         ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3307         if (ret)
3308                 goto out;
3309
3310         *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3311 out_set_summed:
3312         skb->ip_summed = CHECKSUM_NONE;
3313 out:
3314         return ret;
3315 }
3316 EXPORT_SYMBOL(skb_checksum_help);
3317
3318 int skb_crc32c_csum_help(struct sk_buff *skb)
3319 {
3320         __le32 crc32c_csum;
3321         int ret = 0, offset, start;
3322
3323         if (skb->ip_summed != CHECKSUM_PARTIAL)
3324                 goto out;
3325
3326         if (unlikely(skb_is_gso(skb)))
3327                 goto out;
3328
3329         /* Before computing a checksum, we should make sure no frag could
3330          * be modified by an external entity : checksum could be wrong.
3331          */
3332         if (unlikely(skb_has_shared_frag(skb))) {
3333                 ret = __skb_linearize(skb);
3334                 if (ret)
3335                         goto out;
3336         }
3337         start = skb_checksum_start_offset(skb);
3338         offset = start + offsetof(struct sctphdr, checksum);
3339         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3340                 ret = -EINVAL;
3341                 goto out;
3342         }
3343
3344         ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3345         if (ret)
3346                 goto out;
3347
3348         crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3349                                                   skb->len - start, ~(__u32)0,
3350                                                   crc32c_csum_stub));
3351         *(__le32 *)(skb->data + offset) = crc32c_csum;
3352         skb_reset_csum_not_inet(skb);
3353 out:
3354         return ret;
3355 }
3356
3357 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3358 {
3359         __be16 type = skb->protocol;
3360
3361         /* Tunnel gso handlers can set protocol to ethernet. */
3362         if (type == htons(ETH_P_TEB)) {
3363                 struct ethhdr *eth;
3364
3365                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3366                         return 0;
3367
3368                 eth = (struct ethhdr *)skb->data;
3369                 type = eth->h_proto;
3370         }
3371
3372         return vlan_get_protocol_and_depth(skb, type, depth);
3373 }
3374
3375
3376 /* Take action when hardware reception checksum errors are detected. */
3377 #ifdef CONFIG_BUG
3378 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3379 {
3380         netdev_err(dev, "hw csum failure\n");
3381         skb_dump(KERN_ERR, skb, true);
3382         dump_stack();
3383 }
3384
3385 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3386 {
3387         DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3388 }
3389 EXPORT_SYMBOL(netdev_rx_csum_fault);
3390 #endif
3391
3392 /* XXX: check that highmem exists at all on the given machine. */
3393 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3394 {
3395 #ifdef CONFIG_HIGHMEM
3396         int i;
3397
3398         if (!(dev->features & NETIF_F_HIGHDMA)) {
3399                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3400                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3401
3402                         if (PageHighMem(skb_frag_page(frag)))
3403                                 return 1;
3404                 }
3405         }
3406 #endif
3407         return 0;
3408 }
3409
3410 /* If MPLS offload request, verify we are testing hardware MPLS features
3411  * instead of standard features for the netdev.
3412  */
3413 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3414 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3415                                            netdev_features_t features,
3416                                            __be16 type)
3417 {
3418         if (eth_p_mpls(type))
3419                 features &= skb->dev->mpls_features;
3420
3421         return features;
3422 }
3423 #else
3424 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3425                                            netdev_features_t features,
3426                                            __be16 type)
3427 {
3428         return features;
3429 }
3430 #endif
3431
3432 static netdev_features_t harmonize_features(struct sk_buff *skb,
3433         netdev_features_t features)
3434 {
3435         __be16 type;
3436
3437         type = skb_network_protocol(skb, NULL);
3438         features = net_mpls_features(skb, features, type);
3439
3440         if (skb->ip_summed != CHECKSUM_NONE &&
3441             !can_checksum_protocol(features, type)) {
3442                 features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3443         }
3444         if (illegal_highdma(skb->dev, skb))
3445                 features &= ~NETIF_F_SG;
3446
3447         return features;
3448 }
3449
3450 netdev_features_t passthru_features_check(struct sk_buff *skb,
3451                                           struct net_device *dev,
3452                                           netdev_features_t features)
3453 {
3454         return features;
3455 }
3456 EXPORT_SYMBOL(passthru_features_check);
3457
3458 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3459                                              struct net_device *dev,
3460                                              netdev_features_t features)
3461 {
3462         return vlan_features_check(skb, features);
3463 }
3464
3465 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3466                                             struct net_device *dev,
3467                                             netdev_features_t features)
3468 {
3469         u16 gso_segs = skb_shinfo(skb)->gso_segs;
3470
3471         if (gso_segs > READ_ONCE(dev->gso_max_segs))
3472                 return features & ~NETIF_F_GSO_MASK;
3473
3474         if (!skb_shinfo(skb)->gso_type) {
3475                 skb_warn_bad_offload(skb);
3476                 return features & ~NETIF_F_GSO_MASK;
3477         }
3478
3479         /* Support for GSO partial features requires software
3480          * intervention before we can actually process the packets
3481          * so we need to strip support for any partial features now
3482          * and we can pull them back in after we have partially
3483          * segmented the frame.
3484          */
3485         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3486                 features &= ~dev->gso_partial_features;
3487
3488         /* Make sure to clear the IPv4 ID mangling feature if the
3489          * IPv4 header has the potential to be fragmented.
3490          */
3491         if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3492                 struct iphdr *iph = skb->encapsulation ?
3493                                     inner_ip_hdr(skb) : ip_hdr(skb);
3494
3495                 if (!(iph->frag_off & htons(IP_DF)))
3496                         features &= ~NETIF_F_TSO_MANGLEID;
3497         }
3498
3499         return features;
3500 }
3501
3502 netdev_features_t netif_skb_features(struct sk_buff *skb)
3503 {
3504         struct net_device *dev = skb->dev;
3505         netdev_features_t features = dev->features;
3506
3507         if (skb_is_gso(skb))
3508                 features = gso_features_check(skb, dev, features);
3509
3510         /* If encapsulation offload request, verify we are testing
3511          * hardware encapsulation features instead of standard
3512          * features for the netdev
3513          */
3514         if (skb->encapsulation)
3515                 features &= dev->hw_enc_features;
3516
3517         if (skb_vlan_tagged(skb))
3518                 features = netdev_intersect_features(features,
3519                                                      dev->vlan_features |
3520                                                      NETIF_F_HW_VLAN_CTAG_TX |
3521                                                      NETIF_F_HW_VLAN_STAG_TX);
3522
3523         if (dev->netdev_ops->ndo_features_check)
3524                 features &= dev->netdev_ops->ndo_features_check(skb, dev,
3525                                                                 features);
3526         else
3527                 features &= dflt_features_check(skb, dev, features);
3528
3529         return harmonize_features(skb, features);
3530 }
3531 EXPORT_SYMBOL(netif_skb_features);
3532
3533 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3534                     struct netdev_queue *txq, bool more)
3535 {
3536         unsigned int len;
3537         int rc;
3538
3539         if (dev_nit_active(dev))
3540                 dev_queue_xmit_nit(skb, dev);
3541
3542         len = skb->len;
3543         trace_net_dev_start_xmit(skb, dev);
3544         rc = netdev_start_xmit(skb, dev, txq, more);
3545         trace_net_dev_xmit(skb, rc, dev, len);
3546
3547         return rc;
3548 }
3549
3550 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3551                                     struct netdev_queue *txq, int *ret)
3552 {
3553         struct sk_buff *skb = first;
3554         int rc = NETDEV_TX_OK;
3555
3556         while (skb) {
3557                 struct sk_buff *next = skb->next;
3558
3559                 skb_mark_not_on_list(skb);
3560                 rc = xmit_one(skb, dev, txq, next != NULL);
3561                 if (unlikely(!dev_xmit_complete(rc))) {
3562                         skb->next = next;
3563                         goto out;
3564                 }
3565
3566                 skb = next;
3567                 if (netif_tx_queue_stopped(txq) && skb) {
3568                         rc = NETDEV_TX_BUSY;
3569                         break;
3570                 }
3571         }
3572
3573 out:
3574         *ret = rc;
3575         return skb;
3576 }
3577
3578 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3579                                           netdev_features_t features)
3580 {
3581         if (skb_vlan_tag_present(skb) &&
3582             !vlan_hw_offload_capable(features, skb->vlan_proto))
3583                 skb = __vlan_hwaccel_push_inside(skb);
3584         return skb;
3585 }
3586
3587 int skb_csum_hwoffload_help(struct sk_buff *skb,
3588                             const netdev_features_t features)
3589 {
3590         if (unlikely(skb_csum_is_sctp(skb)))
3591                 return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3592                         skb_crc32c_csum_help(skb);
3593
3594         if (features & NETIF_F_HW_CSUM)
3595                 return 0;
3596
3597         if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3598                 switch (skb->csum_offset) {
3599                 case offsetof(struct tcphdr, check):
3600                 case offsetof(struct udphdr, check):
3601                         return 0;
3602                 }
3603         }
3604
3605         return skb_checksum_help(skb);
3606 }
3607 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3608
3609 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3610 {
3611         netdev_features_t features;
3612
3613         features = netif_skb_features(skb);
3614         skb = validate_xmit_vlan(skb, features);
3615         if (unlikely(!skb))
3616                 goto out_null;
3617
3618         skb = sk_validate_xmit_skb(skb, dev);
3619         if (unlikely(!skb))
3620                 goto out_null;
3621
3622         if (netif_needs_gso(skb, features)) {
3623                 struct sk_buff *segs;
3624
3625                 segs = skb_gso_segment(skb, features);
3626                 if (IS_ERR(segs)) {
3627                         goto out_kfree_skb;
3628                 } else if (segs) {
3629                         consume_skb(skb);
3630                         skb = segs;
3631                 }
3632         } else {
3633                 if (skb_needs_linearize(skb, features) &&
3634                     __skb_linearize(skb))
3635                         goto out_kfree_skb;
3636
3637                 /* If packet is not checksummed and device does not
3638                  * support checksumming for this protocol, complete
3639                  * checksumming here.
3640                  */
3641                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3642                         if (skb->encapsulation)
3643                                 skb_set_inner_transport_header(skb,
3644                                                                skb_checksum_start_offset(skb));
3645                         else
3646                                 skb_set_transport_header(skb,
3647                                                          skb_checksum_start_offset(skb));
3648                         if (skb_csum_hwoffload_help(skb, features))
3649                                 goto out_kfree_skb;
3650                 }
3651         }
3652
3653         skb = validate_xmit_xfrm(skb, features, again);
3654
3655         return skb;
3656
3657 out_kfree_skb:
3658         kfree_skb(skb);
3659 out_null:
3660         dev_core_stats_tx_dropped_inc(dev);
3661         return NULL;
3662 }
3663
3664 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3665 {
3666         struct sk_buff *next, *head = NULL, *tail;
3667
3668         for (; skb != NULL; skb = next) {
3669                 next = skb->next;
3670                 skb_mark_not_on_list(skb);
3671
3672                 /* in case skb wont be segmented, point to itself */
3673                 skb->prev = skb;
3674
3675                 skb = validate_xmit_skb(skb, dev, again);
3676                 if (!skb)
3677                         continue;
3678
3679                 if (!head)
3680                         head = skb;
3681                 else
3682                         tail->next = skb;
3683                 /* If skb was segmented, skb->prev points to
3684                  * the last segment. If not, it still contains skb.
3685                  */
3686                 tail = skb->prev;
3687         }
3688         return head;
3689 }
3690 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3691
3692 static void qdisc_pkt_len_init(struct sk_buff *skb)
3693 {
3694         const struct skb_shared_info *shinfo = skb_shinfo(skb);
3695
3696         qdisc_skb_cb(skb)->pkt_len = skb->len;
3697
3698         /* To get more precise estimation of bytes sent on wire,
3699          * we add to pkt_len the headers size of all segments
3700          */
3701         if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3702                 u16 gso_segs = shinfo->gso_segs;
3703                 unsigned int hdr_len;
3704
3705                 /* mac layer + network layer */
3706                 hdr_len = skb_transport_offset(skb);
3707
3708                 /* + transport layer */
3709                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3710                         const struct tcphdr *th;
3711                         struct tcphdr _tcphdr;
3712
3713                         th = skb_header_pointer(skb, hdr_len,
3714                                                 sizeof(_tcphdr), &_tcphdr);
3715                         if (likely(th))
3716                                 hdr_len += __tcp_hdrlen(th);
3717                 } else {
3718                         struct udphdr _udphdr;
3719
3720                         if (skb_header_pointer(skb, hdr_len,
3721                                                sizeof(_udphdr), &_udphdr))
3722                                 hdr_len += sizeof(struct udphdr);
3723                 }
3724
3725                 if (shinfo->gso_type & SKB_GSO_DODGY)
3726                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3727                                                 shinfo->gso_size);
3728
3729                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3730         }
3731 }
3732
3733 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3734                              struct sk_buff **to_free,
3735                              struct netdev_queue *txq)
3736 {
3737         int rc;
3738
3739         rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3740         if (rc == NET_XMIT_SUCCESS)
3741                 trace_qdisc_enqueue(q, txq, skb);
3742         return rc;
3743 }
3744
3745 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3746                                  struct net_device *dev,
3747                                  struct netdev_queue *txq)
3748 {
3749         spinlock_t *root_lock = qdisc_lock(q);
3750         struct sk_buff *to_free = NULL;
3751         bool contended;
3752         int rc;
3753
3754         qdisc_calculate_pkt_len(skb, q);
3755
3756         if (q->flags & TCQ_F_NOLOCK) {
3757                 if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3758                     qdisc_run_begin(q)) {
3759                         /* Retest nolock_qdisc_is_empty() within the protection
3760                          * of q->seqlock to protect from racing with requeuing.
3761                          */
3762                         if (unlikely(!nolock_qdisc_is_empty(q))) {
3763                                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3764                                 __qdisc_run(q);
3765                                 qdisc_run_end(q);
3766
3767                                 goto no_lock_out;
3768                         }
3769
3770                         qdisc_bstats_cpu_update(q, skb);
3771                         if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3772                             !nolock_qdisc_is_empty(q))
3773                                 __qdisc_run(q);
3774
3775                         qdisc_run_end(q);
3776                         return NET_XMIT_SUCCESS;
3777                 }
3778
3779                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3780                 qdisc_run(q);
3781
3782 no_lock_out:
3783                 if (unlikely(to_free))
3784                         kfree_skb_list_reason(to_free,
3785                                               SKB_DROP_REASON_QDISC_DROP);
3786                 return rc;
3787         }
3788
3789         /*
3790          * Heuristic to force contended enqueues to serialize on a
3791          * separate lock before trying to get qdisc main lock.
3792          * This permits qdisc->running owner to get the lock more
3793          * often and dequeue packets faster.
3794          * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3795          * and then other tasks will only enqueue packets. The packets will be
3796          * sent after the qdisc owner is scheduled again. To prevent this
3797          * scenario the task always serialize on the lock.
3798          */
3799         contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3800         if (unlikely(contended))
3801                 spin_lock(&q->busylock);
3802
3803         spin_lock(root_lock);
3804         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3805                 __qdisc_drop(skb, &to_free);
3806                 rc = NET_XMIT_DROP;
3807         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3808                    qdisc_run_begin(q)) {
3809                 /*
3810                  * This is a work-conserving queue; there are no old skbs
3811                  * waiting to be sent out; and the qdisc is not running -
3812                  * xmit the skb directly.
3813                  */
3814
3815                 qdisc_bstats_update(q, skb);
3816
3817                 if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3818                         if (unlikely(contended)) {
3819                                 spin_unlock(&q->busylock);
3820                                 contended = false;
3821                         }
3822                         __qdisc_run(q);
3823                 }
3824
3825                 qdisc_run_end(q);
3826                 rc = NET_XMIT_SUCCESS;
3827         } else {
3828                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3829                 if (qdisc_run_begin(q)) {
3830                         if (unlikely(contended)) {
3831                                 spin_unlock(&q->busylock);
3832                                 contended = false;
3833                         }
3834                         __qdisc_run(q);
3835                         qdisc_run_end(q);
3836                 }
3837         }
3838         spin_unlock(root_lock);
3839         if (unlikely(to_free))
3840                 kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3841         if (unlikely(contended))
3842                 spin_unlock(&q->busylock);
3843         return rc;
3844 }
3845
3846 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3847 static void skb_update_prio(struct sk_buff *skb)
3848 {
3849         const struct netprio_map *map;
3850         const struct sock *sk;
3851         unsigned int prioidx;
3852
3853         if (skb->priority)
3854                 return;
3855         map = rcu_dereference_bh(skb->dev->priomap);
3856         if (!map)
3857                 return;
3858         sk = skb_to_full_sk(skb);
3859         if (!sk)
3860                 return;
3861
3862         prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3863
3864         if (prioidx < map->priomap_len)
3865                 skb->priority = map->priomap[prioidx];
3866 }
3867 #else
3868 #define skb_update_prio(skb)
3869 #endif
3870
3871 /**
3872  *      dev_loopback_xmit - loop back @skb
3873  *      @net: network namespace this loopback is happening in
3874  *      @sk:  sk needed to be a netfilter okfn
3875  *      @skb: buffer to transmit
3876  */
3877 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3878 {
3879         skb_reset_mac_header(skb);
3880         __skb_pull(skb, skb_network_offset(skb));
3881         skb->pkt_type = PACKET_LOOPBACK;
3882         if (skb->ip_summed == CHECKSUM_NONE)
3883                 skb->ip_summed = CHECKSUM_UNNECESSARY;
3884         DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3885         skb_dst_force(skb);
3886         netif_rx(skb);
3887         return 0;
3888 }
3889 EXPORT_SYMBOL(dev_loopback_xmit);
3890
3891 #ifdef CONFIG_NET_EGRESS
3892 static struct netdev_queue *
3893 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3894 {
3895         int qm = skb_get_queue_mapping(skb);
3896
3897         return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3898 }
3899
3900 static bool netdev_xmit_txqueue_skipped(void)
3901 {
3902         return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3903 }
3904
3905 void netdev_xmit_skip_txqueue(bool skip)
3906 {
3907         __this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3908 }
3909 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3910 #endif /* CONFIG_NET_EGRESS */
3911
3912 #ifdef CONFIG_NET_XGRESS
3913 static int tc_run(struct tcx_entry *entry, struct sk_buff *skb)
3914 {
3915         int ret = TC_ACT_UNSPEC;
3916 #ifdef CONFIG_NET_CLS_ACT
3917         struct mini_Qdisc *miniq = rcu_dereference_bh(entry->miniq);
3918         struct tcf_result res;
3919
3920         if (!miniq)
3921                 return ret;
3922
3923         tc_skb_cb(skb)->mru = 0;
3924         tc_skb_cb(skb)->post_ct = false;
3925
3926         mini_qdisc_bstats_cpu_update(miniq, skb);
3927         ret = tcf_classify(skb, miniq->block, miniq->filter_list, &res, false);
3928         /* Only tcf related quirks below. */
3929         switch (ret) {
3930         case TC_ACT_SHOT:
3931                 mini_qdisc_qstats_cpu_drop(miniq);
3932                 break;
3933         case TC_ACT_OK:
3934         case TC_ACT_RECLASSIFY:
3935                 skb->tc_index = TC_H_MIN(res.classid);
3936                 break;
3937         }
3938 #endif /* CONFIG_NET_CLS_ACT */
3939         return ret;
3940 }
3941
3942 static DEFINE_STATIC_KEY_FALSE(tcx_needed_key);
3943
3944 void tcx_inc(void)
3945 {
3946         static_branch_inc(&tcx_needed_key);
3947 }
3948
3949 void tcx_dec(void)
3950 {
3951         static_branch_dec(&tcx_needed_key);
3952 }
3953
3954 static __always_inline enum tcx_action_base
3955 tcx_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb,
3956         const bool needs_mac)
3957 {
3958         const struct bpf_mprog_fp *fp;
3959         const struct bpf_prog *prog;
3960         int ret = TCX_NEXT;
3961
3962         if (needs_mac)
3963                 __skb_push(skb, skb->mac_len);
3964         bpf_mprog_foreach_prog(entry, fp, prog) {
3965                 bpf_compute_data_pointers(skb);
3966                 ret = bpf_prog_run(prog, skb);
3967                 if (ret != TCX_NEXT)
3968                         break;
3969         }
3970         if (needs_mac)
3971                 __skb_pull(skb, skb->mac_len);
3972         return tcx_action_code(skb, ret);
3973 }
3974
3975 static __always_inline struct sk_buff *
3976 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
3977                    struct net_device *orig_dev, bool *another)
3978 {
3979         struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
3980         int sch_ret;
3981
3982         if (!entry)
3983                 return skb;
3984         if (*pt_prev) {
3985                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
3986                 *pt_prev = NULL;
3987         }
3988
3989         qdisc_skb_cb(skb)->pkt_len = skb->len;
3990         tcx_set_ingress(skb, true);
3991
3992         if (static_branch_unlikely(&tcx_needed_key)) {
3993                 sch_ret = tcx_run(entry, skb, true);
3994                 if (sch_ret != TC_ACT_UNSPEC)
3995                         goto ingress_verdict;
3996         }
3997         sch_ret = tc_run(tcx_entry(entry), skb);
3998 ingress_verdict:
3999         switch (sch_ret) {
4000         case TC_ACT_REDIRECT:
4001                 /* skb_mac_header check was done by BPF, so we can safely
4002                  * push the L2 header back before redirecting to another
4003                  * netdev.
4004                  */
4005                 __skb_push(skb, skb->mac_len);
4006                 if (skb_do_redirect(skb) == -EAGAIN) {
4007                         __skb_pull(skb, skb->mac_len);
4008                         *another = true;
4009                         break;
4010                 }
4011                 *ret = NET_RX_SUCCESS;
4012                 return NULL;
4013         case TC_ACT_SHOT:
4014                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
4015                 *ret = NET_RX_DROP;
4016                 return NULL;
4017         /* used by tc_run */
4018         case TC_ACT_STOLEN:
4019         case TC_ACT_QUEUED:
4020         case TC_ACT_TRAP:
4021                 consume_skb(skb);
4022                 fallthrough;
4023         case TC_ACT_CONSUMED:
4024                 *ret = NET_RX_SUCCESS;
4025                 return NULL;
4026         }
4027
4028         return skb;
4029 }
4030
4031 static __always_inline struct sk_buff *
4032 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4033 {
4034         struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
4035         int sch_ret;
4036
4037         if (!entry)
4038                 return skb;
4039
4040         /* qdisc_skb_cb(skb)->pkt_len & tcx_set_ingress() was
4041          * already set by the caller.
4042          */
4043         if (static_branch_unlikely(&tcx_needed_key)) {
4044                 sch_ret = tcx_run(entry, skb, false);
4045                 if (sch_ret != TC_ACT_UNSPEC)
4046                         goto egress_verdict;
4047         }
4048         sch_ret = tc_run(tcx_entry(entry), skb);
4049 egress_verdict:
4050         switch (sch_ret) {
4051         case TC_ACT_REDIRECT:
4052                 /* No need to push/pop skb's mac_header here on egress! */
4053                 skb_do_redirect(skb);
4054                 *ret = NET_XMIT_SUCCESS;
4055                 return NULL;
4056         case TC_ACT_SHOT:
4057                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
4058                 *ret = NET_XMIT_DROP;
4059                 return NULL;
4060         /* used by tc_run */
4061         case TC_ACT_STOLEN:
4062         case TC_ACT_QUEUED:
4063         case TC_ACT_TRAP:
4064                 *ret = NET_XMIT_SUCCESS;
4065                 return NULL;
4066         }
4067
4068         return skb;
4069 }
4070 #else
4071 static __always_inline struct sk_buff *
4072 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4073                    struct net_device *orig_dev, bool *another)
4074 {
4075         return skb;
4076 }
4077
4078 static __always_inline struct sk_buff *
4079 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4080 {
4081         return skb;
4082 }
4083 #endif /* CONFIG_NET_XGRESS */
4084
4085 #ifdef CONFIG_XPS
4086 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4087                                struct xps_dev_maps *dev_maps, unsigned int tci)
4088 {
4089         int tc = netdev_get_prio_tc_map(dev, skb->priority);
4090         struct xps_map *map;
4091         int queue_index = -1;
4092
4093         if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4094                 return queue_index;
4095
4096         tci *= dev_maps->num_tc;
4097         tci += tc;
4098
4099         map = rcu_dereference(dev_maps->attr_map[tci]);
4100         if (map) {
4101                 if (map->len == 1)
4102                         queue_index = map->queues[0];
4103                 else
4104                         queue_index = map->queues[reciprocal_scale(
4105                                                 skb_get_hash(skb), map->len)];
4106                 if (unlikely(queue_index >= dev->real_num_tx_queues))
4107                         queue_index = -1;
4108         }
4109         return queue_index;
4110 }
4111 #endif
4112
4113 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4114                          struct sk_buff *skb)
4115 {
4116 #ifdef CONFIG_XPS
4117         struct xps_dev_maps *dev_maps;
4118         struct sock *sk = skb->sk;
4119         int queue_index = -1;
4120
4121         if (!static_key_false(&xps_needed))
4122                 return -1;
4123
4124         rcu_read_lock();
4125         if (!static_key_false(&xps_rxqs_needed))
4126                 goto get_cpus_map;
4127
4128         dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4129         if (dev_maps) {
4130                 int tci = sk_rx_queue_get(sk);
4131
4132                 if (tci >= 0)
4133                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4134                                                           tci);
4135         }
4136
4137 get_cpus_map:
4138         if (queue_index < 0) {
4139                 dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4140                 if (dev_maps) {
4141                         unsigned int tci = skb->sender_cpu - 1;
4142
4143                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4144                                                           tci);
4145                 }
4146         }
4147         rcu_read_unlock();
4148
4149         return queue_index;
4150 #else
4151         return -1;
4152 #endif
4153 }
4154
4155 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4156                      struct net_device *sb_dev)
4157 {
4158         return 0;
4159 }
4160 EXPORT_SYMBOL(dev_pick_tx_zero);
4161
4162 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4163                        struct net_device *sb_dev)
4164 {
4165         return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4166 }
4167 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4168
4169 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4170                      struct net_device *sb_dev)
4171 {
4172         struct sock *sk = skb->sk;
4173         int queue_index = sk_tx_queue_get(sk);
4174
4175         sb_dev = sb_dev ? : dev;
4176
4177         if (queue_index < 0 || skb->ooo_okay ||
4178             queue_index >= dev->real_num_tx_queues) {
4179                 int new_index = get_xps_queue(dev, sb_dev, skb);
4180
4181                 if (new_index < 0)
4182                         new_index = skb_tx_hash(dev, sb_dev, skb);
4183
4184                 if (queue_index != new_index && sk &&
4185                     sk_fullsock(sk) &&
4186                     rcu_access_pointer(sk->sk_dst_cache))
4187                         sk_tx_queue_set(sk, new_index);
4188
4189                 queue_index = new_index;
4190         }
4191
4192         return queue_index;
4193 }
4194 EXPORT_SYMBOL(netdev_pick_tx);
4195
4196 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4197                                          struct sk_buff *skb,
4198                                          struct net_device *sb_dev)
4199 {
4200         int queue_index = 0;
4201
4202 #ifdef CONFIG_XPS
4203         u32 sender_cpu = skb->sender_cpu - 1;
4204
4205         if (sender_cpu >= (u32)NR_CPUS)
4206                 skb->sender_cpu = raw_smp_processor_id() + 1;
4207 #endif
4208
4209         if (dev->real_num_tx_queues != 1) {
4210                 const struct net_device_ops *ops = dev->netdev_ops;
4211
4212                 if (ops->ndo_select_queue)
4213                         queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4214                 else
4215                         queue_index = netdev_pick_tx(dev, skb, sb_dev);
4216
4217                 queue_index = netdev_cap_txqueue(dev, queue_index);
4218         }
4219
4220         skb_set_queue_mapping(skb, queue_index);
4221         return netdev_get_tx_queue(dev, queue_index);
4222 }
4223
4224 /**
4225  * __dev_queue_xmit() - transmit a buffer
4226  * @skb:        buffer to transmit
4227  * @sb_dev:     suboordinate device used for L2 forwarding offload
4228  *
4229  * Queue a buffer for transmission to a network device. The caller must
4230  * have set the device and priority and built the buffer before calling
4231  * this function. The function can be called from an interrupt.
4232  *
4233  * When calling this method, interrupts MUST be enabled. This is because
4234  * the BH enable code must have IRQs enabled so that it will not deadlock.
4235  *
4236  * Regardless of the return value, the skb is consumed, so it is currently
4237  * difficult to retry a send to this method. (You can bump the ref count
4238  * before sending to hold a reference for retry if you are careful.)
4239  *
4240  * Return:
4241  * * 0                          - buffer successfully transmitted
4242  * * positive qdisc return code - NET_XMIT_DROP etc.
4243  * * negative errno             - other errors
4244  */
4245 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4246 {
4247         struct net_device *dev = skb->dev;
4248         struct netdev_queue *txq = NULL;
4249         struct Qdisc *q;
4250         int rc = -ENOMEM;
4251         bool again = false;
4252
4253         skb_reset_mac_header(skb);
4254         skb_assert_len(skb);
4255
4256         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4257                 __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4258
4259         /* Disable soft irqs for various locks below. Also
4260          * stops preemption for RCU.
4261          */
4262         rcu_read_lock_bh();
4263
4264         skb_update_prio(skb);
4265
4266         qdisc_pkt_len_init(skb);
4267         tcx_set_ingress(skb, false);
4268 #ifdef CONFIG_NET_EGRESS
4269         if (static_branch_unlikely(&egress_needed_key)) {
4270                 if (nf_hook_egress_active()) {
4271                         skb = nf_hook_egress(skb, &rc, dev);
4272                         if (!skb)
4273                                 goto out;
4274                 }
4275
4276                 netdev_xmit_skip_txqueue(false);
4277
4278                 nf_skip_egress(skb, true);
4279                 skb = sch_handle_egress(skb, &rc, dev);
4280                 if (!skb)
4281                         goto out;
4282                 nf_skip_egress(skb, false);
4283
4284                 if (netdev_xmit_txqueue_skipped())
4285                         txq = netdev_tx_queue_mapping(dev, skb);
4286         }
4287 #endif
4288         /* If device/qdisc don't need skb->dst, release it right now while
4289          * its hot in this cpu cache.
4290          */
4291         if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4292                 skb_dst_drop(skb);
4293         else
4294                 skb_dst_force(skb);
4295
4296         if (!txq)
4297                 txq = netdev_core_pick_tx(dev, skb, sb_dev);
4298
4299         q = rcu_dereference_bh(txq->qdisc);
4300
4301         trace_net_dev_queue(skb);
4302         if (q->enqueue) {
4303                 rc = __dev_xmit_skb(skb, q, dev, txq);
4304                 goto out;
4305         }
4306
4307         /* The device has no queue. Common case for software devices:
4308          * loopback, all the sorts of tunnels...
4309
4310          * Really, it is unlikely that netif_tx_lock protection is necessary
4311          * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4312          * counters.)
4313          * However, it is possible, that they rely on protection
4314          * made by us here.
4315
4316          * Check this and shot the lock. It is not prone from deadlocks.
4317          *Either shot noqueue qdisc, it is even simpler 8)
4318          */
4319         if (dev->flags & IFF_UP) {
4320                 int cpu = smp_processor_id(); /* ok because BHs are off */
4321
4322                 /* Other cpus might concurrently change txq->xmit_lock_owner
4323                  * to -1 or to their cpu id, but not to our id.
4324                  */
4325                 if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4326                         if (dev_xmit_recursion())
4327                                 goto recursion_alert;
4328
4329                         skb = validate_xmit_skb(skb, dev, &again);
4330                         if (!skb)
4331                                 goto out;
4332
4333                         HARD_TX_LOCK(dev, txq, cpu);
4334
4335                         if (!netif_xmit_stopped(txq)) {
4336                                 dev_xmit_recursion_inc();
4337                                 skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4338                                 dev_xmit_recursion_dec();
4339                                 if (dev_xmit_complete(rc)) {
4340                                         HARD_TX_UNLOCK(dev, txq);
4341                                         goto out;
4342                                 }
4343                         }
4344                         HARD_TX_UNLOCK(dev, txq);
4345                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4346                                              dev->name);
4347                 } else {
4348                         /* Recursion is detected! It is possible,
4349                          * unfortunately
4350                          */
4351 recursion_alert:
4352                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4353                                              dev->name);
4354                 }
4355         }
4356
4357         rc = -ENETDOWN;
4358         rcu_read_unlock_bh();
4359
4360         dev_core_stats_tx_dropped_inc(dev);
4361         kfree_skb_list(skb);
4362         return rc;
4363 out:
4364         rcu_read_unlock_bh();
4365         return rc;
4366 }
4367 EXPORT_SYMBOL(__dev_queue_xmit);
4368
4369 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4370 {
4371         struct net_device *dev = skb->dev;
4372         struct sk_buff *orig_skb = skb;
4373         struct netdev_queue *txq;
4374         int ret = NETDEV_TX_BUSY;
4375         bool again = false;
4376
4377         if (unlikely(!netif_running(dev) ||
4378                      !netif_carrier_ok(dev)))
4379                 goto drop;
4380
4381         skb = validate_xmit_skb_list(skb, dev, &again);
4382         if (skb != orig_skb)
4383                 goto drop;
4384
4385         skb_set_queue_mapping(skb, queue_id);
4386         txq = skb_get_tx_queue(dev, skb);
4387
4388         local_bh_disable();
4389
4390         dev_xmit_recursion_inc();
4391         HARD_TX_LOCK(dev, txq, smp_processor_id());
4392         if (!netif_xmit_frozen_or_drv_stopped(txq))
4393                 ret = netdev_start_xmit(skb, dev, txq, false);
4394         HARD_TX_UNLOCK(dev, txq);
4395         dev_xmit_recursion_dec();
4396
4397         local_bh_enable();
4398         return ret;
4399 drop:
4400         dev_core_stats_tx_dropped_inc(dev);
4401         kfree_skb_list(skb);
4402         return NET_XMIT_DROP;
4403 }
4404 EXPORT_SYMBOL(__dev_direct_xmit);
4405
4406 /*************************************************************************
4407  *                      Receiver routines
4408  *************************************************************************/
4409
4410 int netdev_max_backlog __read_mostly = 1000;
4411 EXPORT_SYMBOL(netdev_max_backlog);
4412
4413 int netdev_tstamp_prequeue __read_mostly = 1;
4414 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4415 int netdev_budget __read_mostly = 300;
4416 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4417 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4418 int weight_p __read_mostly = 64;           /* old backlog weight */
4419 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4420 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4421 int dev_rx_weight __read_mostly = 64;
4422 int dev_tx_weight __read_mostly = 64;
4423
4424 /* Called with irq disabled */
4425 static inline void ____napi_schedule(struct softnet_data *sd,
4426                                      struct napi_struct *napi)
4427 {
4428         struct task_struct *thread;
4429
4430         lockdep_assert_irqs_disabled();
4431
4432         if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4433                 /* Paired with smp_mb__before_atomic() in
4434                  * napi_enable()/dev_set_threaded().
4435                  * Use READ_ONCE() to guarantee a complete
4436                  * read on napi->thread. Only call
4437                  * wake_up_process() when it's not NULL.
4438                  */
4439                 thread = READ_ONCE(napi->thread);
4440                 if (thread) {
4441                         /* Avoid doing set_bit() if the thread is in
4442                          * INTERRUPTIBLE state, cause napi_thread_wait()
4443                          * makes sure to proceed with napi polling
4444                          * if the thread is explicitly woken from here.
4445                          */
4446                         if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4447                                 set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4448                         wake_up_process(thread);
4449                         return;
4450                 }
4451         }
4452
4453         list_add_tail(&napi->poll_list, &sd->poll_list);
4454         WRITE_ONCE(napi->list_owner, smp_processor_id());
4455         /* If not called from net_rx_action()
4456          * we have to raise NET_RX_SOFTIRQ.
4457          */
4458         if (!sd->in_net_rx_action)
4459                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4460 }
4461
4462 #ifdef CONFIG_RPS
4463
4464 /* One global table that all flow-based protocols share. */
4465 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4466 EXPORT_SYMBOL(rps_sock_flow_table);
4467 u32 rps_cpu_mask __read_mostly;
4468 EXPORT_SYMBOL(rps_cpu_mask);
4469
4470 struct static_key_false rps_needed __read_mostly;
4471 EXPORT_SYMBOL(rps_needed);
4472 struct static_key_false rfs_needed __read_mostly;
4473 EXPORT_SYMBOL(rfs_needed);
4474
4475 static struct rps_dev_flow *
4476 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4477             struct rps_dev_flow *rflow, u16 next_cpu)
4478 {
4479         if (next_cpu < nr_cpu_ids) {
4480 #ifdef CONFIG_RFS_ACCEL
4481                 struct netdev_rx_queue *rxqueue;
4482                 struct rps_dev_flow_table *flow_table;
4483                 struct rps_dev_flow *old_rflow;
4484                 u32 flow_id;
4485                 u16 rxq_index;
4486                 int rc;
4487
4488                 /* Should we steer this flow to a different hardware queue? */
4489                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4490                     !(dev->features & NETIF_F_NTUPLE))
4491                         goto out;
4492                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4493                 if (rxq_index == skb_get_rx_queue(skb))
4494                         goto out;
4495
4496                 rxqueue = dev->_rx + rxq_index;
4497                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
4498                 if (!flow_table)
4499                         goto out;
4500                 flow_id = skb_get_hash(skb) & flow_table->mask;
4501                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4502                                                         rxq_index, flow_id);
4503                 if (rc < 0)
4504                         goto out;
4505                 old_rflow = rflow;
4506                 rflow = &flow_table->flows[flow_id];
4507                 rflow->filter = rc;
4508                 if (old_rflow->filter == rflow->filter)
4509                         old_rflow->filter = RPS_NO_FILTER;
4510         out:
4511 #endif
4512                 rflow->last_qtail =
4513                         per_cpu(softnet_data, next_cpu).input_queue_head;
4514         }
4515
4516         rflow->cpu = next_cpu;
4517         return rflow;
4518 }
4519
4520 /*
4521  * get_rps_cpu is called from netif_receive_skb and returns the target
4522  * CPU from the RPS map of the receiving queue for a given skb.
4523  * rcu_read_lock must be held on entry.
4524  */
4525 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4526                        struct rps_dev_flow **rflowp)
4527 {
4528         const struct rps_sock_flow_table *sock_flow_table;
4529         struct netdev_rx_queue *rxqueue = dev->_rx;
4530         struct rps_dev_flow_table *flow_table;
4531         struct rps_map *map;
4532         int cpu = -1;
4533         u32 tcpu;
4534         u32 hash;
4535
4536         if (skb_rx_queue_recorded(skb)) {
4537                 u16 index = skb_get_rx_queue(skb);
4538
4539                 if (unlikely(index >= dev->real_num_rx_queues)) {
4540                         WARN_ONCE(dev->real_num_rx_queues > 1,
4541                                   "%s received packet on queue %u, but number "
4542                                   "of RX queues is %u\n",
4543                                   dev->name, index, dev->real_num_rx_queues);
4544                         goto done;
4545                 }
4546                 rxqueue += index;
4547         }
4548
4549         /* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4550
4551         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4552         map = rcu_dereference(rxqueue->rps_map);
4553         if (!flow_table && !map)
4554                 goto done;
4555
4556         skb_reset_network_header(skb);
4557         hash = skb_get_hash(skb);
4558         if (!hash)
4559                 goto done;
4560
4561         sock_flow_table = rcu_dereference(rps_sock_flow_table);
4562         if (flow_table && sock_flow_table) {
4563                 struct rps_dev_flow *rflow;
4564                 u32 next_cpu;
4565                 u32 ident;
4566
4567                 /* First check into global flow table if there is a match.
4568                  * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
4569                  */
4570                 ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
4571                 if ((ident ^ hash) & ~rps_cpu_mask)
4572                         goto try_rps;
4573
4574                 next_cpu = ident & rps_cpu_mask;
4575
4576                 /* OK, now we know there is a match,
4577                  * we can look at the local (per receive queue) flow table
4578                  */
4579                 rflow = &flow_table->flows[hash & flow_table->mask];
4580                 tcpu = rflow->cpu;
4581
4582                 /*
4583                  * If the desired CPU (where last recvmsg was done) is
4584                  * different from current CPU (one in the rx-queue flow
4585                  * table entry), switch if one of the following holds:
4586                  *   - Current CPU is unset (>= nr_cpu_ids).
4587                  *   - Current CPU is offline.
4588                  *   - The current CPU's queue tail has advanced beyond the
4589                  *     last packet that was enqueued using this table entry.
4590                  *     This guarantees that all previous packets for the flow
4591                  *     have been dequeued, thus preserving in order delivery.
4592                  */
4593                 if (unlikely(tcpu != next_cpu) &&
4594                     (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4595                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4596                       rflow->last_qtail)) >= 0)) {
4597                         tcpu = next_cpu;
4598                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4599                 }
4600
4601                 if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4602                         *rflowp = rflow;
4603                         cpu = tcpu;
4604                         goto done;
4605                 }
4606         }
4607
4608 try_rps:
4609
4610         if (map) {
4611                 tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4612                 if (cpu_online(tcpu)) {
4613                         cpu = tcpu;
4614                         goto done;
4615                 }
4616         }
4617
4618 done:
4619         return cpu;
4620 }
4621
4622 #ifdef CONFIG_RFS_ACCEL
4623
4624 /**
4625  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4626  * @dev: Device on which the filter was set
4627  * @rxq_index: RX queue index
4628  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4629  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4630  *
4631  * Drivers that implement ndo_rx_flow_steer() should periodically call
4632  * this function for each installed filter and remove the filters for
4633  * which it returns %true.
4634  */
4635 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4636                          u32 flow_id, u16 filter_id)
4637 {
4638         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4639         struct rps_dev_flow_table *flow_table;
4640         struct rps_dev_flow *rflow;
4641         bool expire = true;
4642         unsigned int cpu;
4643
4644         rcu_read_lock();
4645         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4646         if (flow_table && flow_id <= flow_table->mask) {
4647                 rflow = &flow_table->flows[flow_id];
4648                 cpu = READ_ONCE(rflow->cpu);
4649                 if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4650                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4651                            rflow->last_qtail) <
4652                      (int)(10 * flow_table->mask)))
4653                         expire = false;
4654         }
4655         rcu_read_unlock();
4656         return expire;
4657 }
4658 EXPORT_SYMBOL(rps_may_expire_flow);
4659
4660 #endif /* CONFIG_RFS_ACCEL */
4661
4662 /* Called from hardirq (IPI) context */
4663 static void rps_trigger_softirq(void *data)
4664 {
4665         struct softnet_data *sd = data;
4666
4667         ____napi_schedule(sd, &sd->backlog);
4668         sd->received_rps++;
4669 }
4670
4671 #endif /* CONFIG_RPS */
4672
4673 /* Called from hardirq (IPI) context */
4674 static void trigger_rx_softirq(void *data)
4675 {
4676         struct softnet_data *sd = data;
4677
4678         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4679         smp_store_release(&sd->defer_ipi_scheduled, 0);
4680 }
4681
4682 /*
4683  * After we queued a packet into sd->input_pkt_queue,
4684  * we need to make sure this queue is serviced soon.
4685  *
4686  * - If this is another cpu queue, link it to our rps_ipi_list,
4687  *   and make sure we will process rps_ipi_list from net_rx_action().
4688  *
4689  * - If this is our own queue, NAPI schedule our backlog.
4690  *   Note that this also raises NET_RX_SOFTIRQ.
4691  */
4692 static void napi_schedule_rps(struct softnet_data *sd)
4693 {
4694         struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4695
4696 #ifdef CONFIG_RPS
4697         if (sd != mysd) {
4698                 sd->rps_ipi_next = mysd->rps_ipi_list;
4699                 mysd->rps_ipi_list = sd;
4700
4701                 /* If not called from net_rx_action() or napi_threaded_poll()
4702                  * we have to raise NET_RX_SOFTIRQ.
4703                  */
4704                 if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
4705                         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4706                 return;
4707         }
4708 #endif /* CONFIG_RPS */
4709         __napi_schedule_irqoff(&mysd->backlog);
4710 }
4711
4712 #ifdef CONFIG_NET_FLOW_LIMIT
4713 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4714 #endif
4715
4716 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4717 {
4718 #ifdef CONFIG_NET_FLOW_LIMIT
4719         struct sd_flow_limit *fl;
4720         struct softnet_data *sd;
4721         unsigned int old_flow, new_flow;
4722
4723         if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4724                 return false;
4725
4726         sd = this_cpu_ptr(&softnet_data);
4727
4728         rcu_read_lock();
4729         fl = rcu_dereference(sd->flow_limit);
4730         if (fl) {
4731                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4732                 old_flow = fl->history[fl->history_head];
4733                 fl->history[fl->history_head] = new_flow;
4734
4735                 fl->history_head++;
4736                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4737
4738                 if (likely(fl->buckets[old_flow]))
4739                         fl->buckets[old_flow]--;
4740
4741                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4742                         fl->count++;
4743                         rcu_read_unlock();
4744                         return true;
4745                 }
4746         }
4747         rcu_read_unlock();
4748 #endif
4749         return false;
4750 }
4751
4752 /*
4753  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4754  * queue (may be a remote CPU queue).
4755  */
4756 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4757                               unsigned int *qtail)
4758 {
4759         enum skb_drop_reason reason;
4760         struct softnet_data *sd;
4761         unsigned long flags;
4762         unsigned int qlen;
4763
4764         reason = SKB_DROP_REASON_NOT_SPECIFIED;
4765         sd = &per_cpu(softnet_data, cpu);
4766
4767         rps_lock_irqsave(sd, &flags);
4768         if (!netif_running(skb->dev))
4769                 goto drop;
4770         qlen = skb_queue_len(&sd->input_pkt_queue);
4771         if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4772                 if (qlen) {
4773 enqueue:
4774                         __skb_queue_tail(&sd->input_pkt_queue, skb);
4775                         input_queue_tail_incr_save(sd, qtail);
4776                         rps_unlock_irq_restore(sd, &flags);
4777                         return NET_RX_SUCCESS;
4778                 }
4779
4780                 /* Schedule NAPI for backlog device
4781                  * We can use non atomic operation since we own the queue lock
4782                  */
4783                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4784                         napi_schedule_rps(sd);
4785                 goto enqueue;
4786         }
4787         reason = SKB_DROP_REASON_CPU_BACKLOG;
4788
4789 drop:
4790         sd->dropped++;
4791         rps_unlock_irq_restore(sd, &flags);
4792
4793         dev_core_stats_rx_dropped_inc(skb->dev);
4794         kfree_skb_reason(skb, reason);
4795         return NET_RX_DROP;
4796 }
4797
4798 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4799 {
4800         struct net_device *dev = skb->dev;
4801         struct netdev_rx_queue *rxqueue;
4802
4803         rxqueue = dev->_rx;
4804
4805         if (skb_rx_queue_recorded(skb)) {
4806                 u16 index = skb_get_rx_queue(skb);
4807
4808                 if (unlikely(index >= dev->real_num_rx_queues)) {
4809                         WARN_ONCE(dev->real_num_rx_queues > 1,
4810                                   "%s received packet on queue %u, but number "
4811                                   "of RX queues is %u\n",
4812                                   dev->name, index, dev->real_num_rx_queues);
4813
4814                         return rxqueue; /* Return first rxqueue */
4815                 }
4816                 rxqueue += index;
4817         }
4818         return rxqueue;
4819 }
4820
4821 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4822                              struct bpf_prog *xdp_prog)
4823 {
4824         void *orig_data, *orig_data_end, *hard_start;
4825         struct netdev_rx_queue *rxqueue;
4826         bool orig_bcast, orig_host;
4827         u32 mac_len, frame_sz;
4828         __be16 orig_eth_type;
4829         struct ethhdr *eth;
4830         u32 metalen, act;
4831         int off;
4832
4833         /* The XDP program wants to see the packet starting at the MAC
4834          * header.
4835          */
4836         mac_len = skb->data - skb_mac_header(skb);
4837         hard_start = skb->data - skb_headroom(skb);
4838
4839         /* SKB "head" area always have tailroom for skb_shared_info */
4840         frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4841         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4842
4843         rxqueue = netif_get_rxqueue(skb);
4844         xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4845         xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4846                          skb_headlen(skb) + mac_len, true);
4847
4848         orig_data_end = xdp->data_end;
4849         orig_data = xdp->data;
4850         eth = (struct ethhdr *)xdp->data;
4851         orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4852         orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4853         orig_eth_type = eth->h_proto;
4854
4855         act = bpf_prog_run_xdp(xdp_prog, xdp);
4856
4857         /* check if bpf_xdp_adjust_head was used */
4858         off = xdp->data - orig_data;
4859         if (off) {
4860                 if (off > 0)
4861                         __skb_pull(skb, off);
4862                 else if (off < 0)
4863                         __skb_push(skb, -off);
4864
4865                 skb->mac_header += off;
4866                 skb_reset_network_header(skb);
4867         }
4868
4869         /* check if bpf_xdp_adjust_tail was used */
4870         off = xdp->data_end - orig_data_end;
4871         if (off != 0) {
4872                 skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4873                 skb->len += off; /* positive on grow, negative on shrink */
4874         }
4875
4876         /* check if XDP changed eth hdr such SKB needs update */
4877         eth = (struct ethhdr *)xdp->data;
4878         if ((orig_eth_type != eth->h_proto) ||
4879             (orig_host != ether_addr_equal_64bits(eth->h_dest,
4880                                                   skb->dev->dev_addr)) ||
4881             (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4882                 __skb_push(skb, ETH_HLEN);
4883                 skb->pkt_type = PACKET_HOST;
4884                 skb->protocol = eth_type_trans(skb, skb->dev);
4885         }
4886
4887         /* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4888          * before calling us again on redirect path. We do not call do_redirect
4889          * as we leave that up to the caller.
4890          *
4891          * Caller is responsible for managing lifetime of skb (i.e. calling
4892          * kfree_skb in response to actions it cannot handle/XDP_DROP).
4893          */
4894         switch (act) {
4895         case XDP_REDIRECT:
4896         case XDP_TX:
4897                 __skb_push(skb, mac_len);
4898                 break;
4899         case XDP_PASS:
4900                 metalen = xdp->data - xdp->data_meta;
4901                 if (metalen)
4902                         skb_metadata_set(skb, metalen);
4903                 break;
4904         }
4905
4906         return act;
4907 }
4908
4909 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4910                                      struct xdp_buff *xdp,
4911                                      struct bpf_prog *xdp_prog)
4912 {
4913         u32 act = XDP_DROP;
4914
4915         /* Reinjected packets coming from act_mirred or similar should
4916          * not get XDP generic processing.
4917          */
4918         if (skb_is_redirected(skb))
4919                 return XDP_PASS;
4920
4921         /* XDP packets must be linear and must have sufficient headroom
4922          * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4923          * native XDP provides, thus we need to do it here as well.
4924          */
4925         if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4926             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4927                 int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4928                 int troom = skb->tail + skb->data_len - skb->end;
4929
4930                 /* In case we have to go down the path and also linearize,
4931                  * then lets do the pskb_expand_head() work just once here.
4932                  */
4933                 if (pskb_expand_head(skb,
4934                                      hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4935                                      troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4936                         goto do_drop;
4937                 if (skb_linearize(skb))
4938                         goto do_drop;
4939         }
4940
4941         act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4942         switch (act) {
4943         case XDP_REDIRECT:
4944         case XDP_TX:
4945         case XDP_PASS:
4946                 break;
4947         default:
4948                 bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4949                 fallthrough;
4950         case XDP_ABORTED:
4951                 trace_xdp_exception(skb->dev, xdp_prog, act);
4952                 fallthrough;
4953         case XDP_DROP:
4954         do_drop:
4955                 kfree_skb(skb);
4956                 break;
4957         }
4958
4959         return act;
4960 }
4961
4962 /* When doing generic XDP we have to bypass the qdisc layer and the
4963  * network taps in order to match in-driver-XDP behavior. This also means
4964  * that XDP packets are able to starve other packets going through a qdisc,
4965  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4966  * queues, so they do not have this starvation issue.
4967  */
4968 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4969 {
4970         struct net_device *dev = skb->dev;
4971         struct netdev_queue *txq;
4972         bool free_skb = true;
4973         int cpu, rc;
4974
4975         txq = netdev_core_pick_tx(dev, skb, NULL);
4976         cpu = smp_processor_id();
4977         HARD_TX_LOCK(dev, txq, cpu);
4978         if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4979                 rc = netdev_start_xmit(skb, dev, txq, 0);
4980                 if (dev_xmit_complete(rc))
4981                         free_skb = false;
4982         }
4983         HARD_TX_UNLOCK(dev, txq);
4984         if (free_skb) {
4985                 trace_xdp_exception(dev, xdp_prog, XDP_TX);
4986                 dev_core_stats_tx_dropped_inc(dev);
4987                 kfree_skb(skb);
4988         }
4989 }
4990
4991 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4992
4993 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4994 {
4995         if (xdp_prog) {
4996                 struct xdp_buff xdp;
4997                 u32 act;
4998                 int err;
4999
5000                 act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
5001                 if (act != XDP_PASS) {
5002                         switch (act) {
5003                         case XDP_REDIRECT:
5004                                 err = xdp_do_generic_redirect(skb->dev, skb,
5005                                                               &xdp, xdp_prog);
5006                                 if (err)
5007                                         goto out_redir;
5008                                 break;
5009                         case XDP_TX:
5010                                 generic_xdp_tx(skb, xdp_prog);
5011                                 break;
5012                         }
5013                         return XDP_DROP;
5014                 }
5015         }
5016         return XDP_PASS;
5017 out_redir:
5018         kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
5019         return XDP_DROP;
5020 }
5021 EXPORT_SYMBOL_GPL(do_xdp_generic);
5022
5023 static int netif_rx_internal(struct sk_buff *skb)
5024 {
5025         int ret;
5026
5027         net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5028
5029         trace_netif_rx(skb);
5030
5031 #ifdef CONFIG_RPS
5032         if (static_branch_unlikely(&rps_needed)) {
5033                 struct rps_dev_flow voidflow, *rflow = &voidflow;
5034                 int cpu;
5035
5036                 rcu_read_lock();
5037
5038                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
5039                 if (cpu < 0)
5040                         cpu = smp_processor_id();
5041
5042                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5043
5044                 rcu_read_unlock();
5045         } else
5046 #endif
5047         {
5048                 unsigned int qtail;
5049
5050                 ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
5051         }
5052         return ret;
5053 }
5054
5055 /**
5056  *      __netif_rx      -       Slightly optimized version of netif_rx
5057  *      @skb: buffer to post
5058  *
5059  *      This behaves as netif_rx except that it does not disable bottom halves.
5060  *      As a result this function may only be invoked from the interrupt context
5061  *      (either hard or soft interrupt).
5062  */
5063 int __netif_rx(struct sk_buff *skb)
5064 {
5065         int ret;
5066
5067         lockdep_assert_once(hardirq_count() | softirq_count());
5068
5069         trace_netif_rx_entry(skb);
5070         ret = netif_rx_internal(skb);
5071         trace_netif_rx_exit(ret);
5072         return ret;
5073 }
5074 EXPORT_SYMBOL(__netif_rx);
5075
5076 /**
5077  *      netif_rx        -       post buffer to the network code
5078  *      @skb: buffer to post
5079  *
5080  *      This function receives a packet from a device driver and queues it for
5081  *      the upper (protocol) levels to process via the backlog NAPI device. It
5082  *      always succeeds. The buffer may be dropped during processing for
5083  *      congestion control or by the protocol layers.
5084  *      The network buffer is passed via the backlog NAPI device. Modern NIC
5085  *      driver should use NAPI and GRO.
5086  *      This function can used from interrupt and from process context. The
5087  *      caller from process context must not disable interrupts before invoking
5088  *      this function.
5089  *
5090  *      return values:
5091  *      NET_RX_SUCCESS  (no congestion)
5092  *      NET_RX_DROP     (packet was dropped)
5093  *
5094  */
5095 int netif_rx(struct sk_buff *skb)
5096 {
5097         bool need_bh_off = !(hardirq_count() | softirq_count());
5098         int ret;
5099
5100         if (need_bh_off)
5101                 local_bh_disable();
5102         trace_netif_rx_entry(skb);
5103         ret = netif_rx_internal(skb);
5104         trace_netif_rx_exit(ret);
5105         if (need_bh_off)
5106                 local_bh_enable();
5107         return ret;
5108 }
5109 EXPORT_SYMBOL(netif_rx);
5110
5111 static __latent_entropy void net_tx_action(struct softirq_action *h)
5112 {
5113         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5114
5115         if (sd->completion_queue) {
5116                 struct sk_buff *clist;
5117
5118                 local_irq_disable();
5119                 clist = sd->completion_queue;
5120                 sd->completion_queue = NULL;
5121                 local_irq_enable();
5122
5123                 while (clist) {
5124                         struct sk_buff *skb = clist;
5125
5126                         clist = clist->next;
5127
5128                         WARN_ON(refcount_read(&skb->users));
5129                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5130                                 trace_consume_skb(skb, net_tx_action);
5131                         else
5132                                 trace_kfree_skb(skb, net_tx_action,
5133                                                 get_kfree_skb_cb(skb)->reason);
5134
5135                         if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5136                                 __kfree_skb(skb);
5137                         else
5138                                 __napi_kfree_skb(skb,
5139                                                  get_kfree_skb_cb(skb)->reason);
5140                 }
5141         }
5142
5143         if (sd->output_queue) {
5144                 struct Qdisc *head;
5145
5146                 local_irq_disable();
5147                 head = sd->output_queue;
5148                 sd->output_queue = NULL;
5149                 sd->output_queue_tailp = &sd->output_queue;
5150                 local_irq_enable();
5151
5152                 rcu_read_lock();
5153
5154                 while (head) {
5155                         struct Qdisc *q = head;
5156                         spinlock_t *root_lock = NULL;
5157
5158                         head = head->next_sched;
5159
5160                         /* We need to make sure head->next_sched is read
5161                          * before clearing __QDISC_STATE_SCHED
5162                          */
5163                         smp_mb__before_atomic();
5164
5165                         if (!(q->flags & TCQ_F_NOLOCK)) {
5166                                 root_lock = qdisc_lock(q);
5167                                 spin_lock(root_lock);
5168                         } else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5169                                                      &q->state))) {
5170                                 /* There is a synchronize_net() between
5171                                  * STATE_DEACTIVATED flag being set and
5172                                  * qdisc_reset()/some_qdisc_is_busy() in
5173                                  * dev_deactivate(), so we can safely bail out
5174                                  * early here to avoid data race between
5175                                  * qdisc_deactivate() and some_qdisc_is_busy()
5176                                  * for lockless qdisc.
5177                                  */
5178                                 clear_bit(__QDISC_STATE_SCHED, &q->state);
5179                                 continue;
5180                         }
5181
5182                         clear_bit(__QDISC_STATE_SCHED, &q->state);
5183                         qdisc_run(q);
5184                         if (root_lock)
5185                                 spin_unlock(root_lock);
5186                 }
5187
5188                 rcu_read_unlock();
5189         }
5190
5191         xfrm_dev_backlog(sd);
5192 }
5193
5194 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5195 /* This hook is defined here for ATM LANE */
5196 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5197                              unsigned char *addr) __read_mostly;
5198 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5199 #endif
5200
5201 /**
5202  *      netdev_is_rx_handler_busy - check if receive handler is registered
5203  *      @dev: device to check
5204  *
5205  *      Check if a receive handler is already registered for a given device.
5206  *      Return true if there one.
5207  *
5208  *      The caller must hold the rtnl_mutex.
5209  */
5210 bool netdev_is_rx_handler_busy(struct net_device *dev)
5211 {
5212         ASSERT_RTNL();
5213         return dev && rtnl_dereference(dev->rx_handler);
5214 }
5215 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5216
5217 /**
5218  *      netdev_rx_handler_register - register receive handler
5219  *      @dev: device to register a handler for
5220  *      @rx_handler: receive handler to register
5221  *      @rx_handler_data: data pointer that is used by rx handler
5222  *
5223  *      Register a receive handler for a device. This handler will then be
5224  *      called from __netif_receive_skb. A negative errno code is returned
5225  *      on a failure.
5226  *
5227  *      The caller must hold the rtnl_mutex.
5228  *
5229  *      For a general description of rx_handler, see enum rx_handler_result.
5230  */
5231 int netdev_rx_handler_register(struct net_device *dev,
5232                                rx_handler_func_t *rx_handler,
5233                                void *rx_handler_data)
5234 {
5235         if (netdev_is_rx_handler_busy(dev))
5236                 return -EBUSY;
5237
5238         if (dev->priv_flags & IFF_NO_RX_HANDLER)
5239                 return -EINVAL;
5240
5241         /* Note: rx_handler_data must be set before rx_handler */
5242         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5243         rcu_assign_pointer(dev->rx_handler, rx_handler);
5244
5245         return 0;
5246 }
5247 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5248
5249 /**
5250  *      netdev_rx_handler_unregister - unregister receive handler
5251  *      @dev: device to unregister a handler from
5252  *
5253  *      Unregister a receive handler from a device.
5254  *
5255  *      The caller must hold the rtnl_mutex.
5256  */
5257 void netdev_rx_handler_unregister(struct net_device *dev)
5258 {
5259
5260         ASSERT_RTNL();
5261         RCU_INIT_POINTER(dev->rx_handler, NULL);
5262         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5263          * section has a guarantee to see a non NULL rx_handler_data
5264          * as well.
5265          */
5266         synchronize_net();
5267         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5268 }
5269 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5270
5271 /*
5272  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5273  * the special handling of PFMEMALLOC skbs.
5274  */
5275 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5276 {
5277         switch (skb->protocol) {
5278         case htons(ETH_P_ARP):
5279         case htons(ETH_P_IP):
5280         case htons(ETH_P_IPV6):
5281         case htons(ETH_P_8021Q):
5282         case htons(ETH_P_8021AD):
5283                 return true;
5284         default:
5285                 return false;
5286         }
5287 }
5288
5289 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5290                              int *ret, struct net_device *orig_dev)
5291 {
5292         if (nf_hook_ingress_active(skb)) {
5293                 int ingress_retval;
5294
5295                 if (*pt_prev) {
5296                         *ret = deliver_skb(skb, *pt_prev, orig_dev);
5297                         *pt_prev = NULL;
5298                 }
5299
5300                 rcu_read_lock();
5301                 ingress_retval = nf_hook_ingress(skb);
5302                 rcu_read_unlock();
5303                 return ingress_retval;
5304         }
5305         return 0;
5306 }
5307
5308 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5309                                     struct packet_type **ppt_prev)
5310 {
5311         struct packet_type *ptype, *pt_prev;
5312         rx_handler_func_t *rx_handler;
5313         struct sk_buff *skb = *pskb;
5314         struct net_device *orig_dev;
5315         bool deliver_exact = false;
5316         int ret = NET_RX_DROP;
5317         __be16 type;
5318
5319         net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5320
5321         trace_netif_receive_skb(skb);
5322
5323         orig_dev = skb->dev;
5324
5325         skb_reset_network_header(skb);
5326         if (!skb_transport_header_was_set(skb))
5327                 skb_reset_transport_header(skb);
5328         skb_reset_mac_len(skb);
5329
5330         pt_prev = NULL;
5331
5332 another_round:
5333         skb->skb_iif = skb->dev->ifindex;
5334
5335         __this_cpu_inc(softnet_data.processed);
5336
5337         if (static_branch_unlikely(&generic_xdp_needed_key)) {
5338                 int ret2;
5339
5340                 migrate_disable();
5341                 ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5342                 migrate_enable();
5343
5344                 if (ret2 != XDP_PASS) {
5345                         ret = NET_RX_DROP;
5346                         goto out;
5347                 }
5348         }
5349
5350         if (eth_type_vlan(skb->protocol)) {
5351                 skb = skb_vlan_untag(skb);
5352                 if (unlikely(!skb))
5353                         goto out;
5354         }
5355
5356         if (skb_skip_tc_classify(skb))
5357                 goto skip_classify;
5358
5359         if (pfmemalloc)
5360                 goto skip_taps;
5361
5362         list_for_each_entry_rcu(ptype, &ptype_all, list) {
5363                 if (pt_prev)
5364                         ret = deliver_skb(skb, pt_prev, orig_dev);
5365                 pt_prev = ptype;
5366         }
5367
5368         list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5369                 if (pt_prev)
5370                         ret = deliver_skb(skb, pt_prev, orig_dev);
5371                 pt_prev = ptype;
5372         }
5373
5374 skip_taps:
5375 #ifdef CONFIG_NET_INGRESS
5376         if (static_branch_unlikely(&ingress_needed_key)) {
5377                 bool another = false;
5378
5379                 nf_skip_egress(skb, true);
5380                 skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5381                                          &another);
5382                 if (another)
5383                         goto another_round;
5384                 if (!skb)
5385                         goto out;
5386
5387                 nf_skip_egress(skb, false);
5388                 if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5389                         goto out;
5390         }
5391 #endif
5392         skb_reset_redirect(skb);
5393 skip_classify:
5394         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5395                 goto drop;
5396
5397         if (skb_vlan_tag_present(skb)) {
5398                 if (pt_prev) {
5399                         ret = deliver_skb(skb, pt_prev, orig_dev);
5400                         pt_prev = NULL;
5401                 }
5402                 if (vlan_do_receive(&skb))
5403                         goto another_round;
5404                 else if (unlikely(!skb))
5405                         goto out;
5406         }
5407
5408         rx_handler = rcu_dereference(skb->dev->rx_handler);
5409         if (rx_handler) {
5410                 if (pt_prev) {
5411                         ret = deliver_skb(skb, pt_prev, orig_dev);
5412                         pt_prev = NULL;
5413                 }
5414                 switch (rx_handler(&skb)) {
5415                 case RX_HANDLER_CONSUMED:
5416                         ret = NET_RX_SUCCESS;
5417                         goto out;
5418                 case RX_HANDLER_ANOTHER:
5419                         goto another_round;
5420                 case RX_HANDLER_EXACT:
5421                         deliver_exact = true;
5422                         break;
5423                 case RX_HANDLER_PASS:
5424                         break;
5425                 default:
5426                         BUG();
5427                 }
5428         }
5429
5430         if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5431 check_vlan_id:
5432                 if (skb_vlan_tag_get_id(skb)) {
5433                         /* Vlan id is non 0 and vlan_do_receive() above couldn't
5434                          * find vlan device.
5435                          */
5436                         skb->pkt_type = PACKET_OTHERHOST;
5437                 } else if (eth_type_vlan(skb->protocol)) {
5438                         /* Outer header is 802.1P with vlan 0, inner header is
5439                          * 802.1Q or 802.1AD and vlan_do_receive() above could
5440                          * not find vlan dev for vlan id 0.
5441                          */
5442                         __vlan_hwaccel_clear_tag(skb);
5443                         skb = skb_vlan_untag(skb);
5444                         if (unlikely(!skb))
5445                                 goto out;
5446                         if (vlan_do_receive(&skb))
5447                                 /* After stripping off 802.1P header with vlan 0
5448                                  * vlan dev is found for inner header.
5449                                  */
5450                                 goto another_round;
5451                         else if (unlikely(!skb))
5452                                 goto out;
5453                         else
5454                                 /* We have stripped outer 802.1P vlan 0 header.
5455                                  * But could not find vlan dev.
5456                                  * check again for vlan id to set OTHERHOST.
5457                                  */
5458                                 goto check_vlan_id;
5459                 }
5460                 /* Note: we might in the future use prio bits
5461                  * and set skb->priority like in vlan_do_receive()
5462                  * For the time being, just ignore Priority Code Point
5463                  */
5464                 __vlan_hwaccel_clear_tag(skb);
5465         }
5466
5467         type = skb->protocol;
5468
5469         /* deliver only exact match when indicated */
5470         if (likely(!deliver_exact)) {
5471                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5472                                        &ptype_base[ntohs(type) &
5473                                                    PTYPE_HASH_MASK]);
5474         }
5475
5476         deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5477                                &orig_dev->ptype_specific);
5478
5479         if (unlikely(skb->dev != orig_dev)) {
5480                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5481                                        &skb->dev->ptype_specific);
5482         }
5483
5484         if (pt_prev) {
5485                 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5486                         goto drop;
5487                 *ppt_prev = pt_prev;
5488         } else {
5489 drop:
5490                 if (!deliver_exact)
5491                         dev_core_stats_rx_dropped_inc(skb->dev);
5492                 else
5493                         dev_core_stats_rx_nohandler_inc(skb->dev);
5494                 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5495                 /* Jamal, now you will not able to escape explaining
5496                  * me how you were going to use this. :-)
5497                  */
5498                 ret = NET_RX_DROP;
5499         }
5500
5501 out:
5502         /* The invariant here is that if *ppt_prev is not NULL
5503          * then skb should also be non-NULL.
5504          *
5505          * Apparently *ppt_prev assignment above holds this invariant due to
5506          * skb dereferencing near it.
5507          */
5508         *pskb = skb;
5509         return ret;
5510 }
5511
5512 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5513 {
5514         struct net_device *orig_dev = skb->dev;
5515         struct packet_type *pt_prev = NULL;
5516         int ret;
5517
5518         ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5519         if (pt_prev)
5520                 ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5521                                          skb->dev, pt_prev, orig_dev);
5522         return ret;
5523 }
5524
5525 /**
5526  *      netif_receive_skb_core - special purpose version of netif_receive_skb
5527  *      @skb: buffer to process
5528  *
5529  *      More direct receive version of netif_receive_skb().  It should
5530  *      only be used by callers that have a need to skip RPS and Generic XDP.
5531  *      Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5532  *
5533  *      This function may only be called from softirq context and interrupts
5534  *      should be enabled.
5535  *
5536  *      Return values (usually ignored):
5537  *      NET_RX_SUCCESS: no congestion
5538  *      NET_RX_DROP: packet was dropped
5539  */
5540 int netif_receive_skb_core(struct sk_buff *skb)
5541 {
5542         int ret;
5543
5544         rcu_read_lock();
5545         ret = __netif_receive_skb_one_core(skb, false);
5546         rcu_read_unlock();
5547
5548         return ret;
5549 }
5550 EXPORT_SYMBOL(netif_receive_skb_core);
5551
5552 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5553                                                   struct packet_type *pt_prev,
5554                                                   struct net_device *orig_dev)
5555 {
5556         struct sk_buff *skb, *next;
5557
5558         if (!pt_prev)
5559                 return;
5560         if (list_empty(head))
5561                 return;
5562         if (pt_prev->list_func != NULL)
5563                 INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5564                                    ip_list_rcv, head, pt_prev, orig_dev);
5565         else
5566                 list_for_each_entry_safe(skb, next, head, list) {
5567                         skb_list_del_init(skb);
5568                         pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5569                 }
5570 }
5571
5572 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5573 {
5574         /* Fast-path assumptions:
5575          * - There is no RX handler.
5576          * - Only one packet_type matches.
5577          * If either of these fails, we will end up doing some per-packet
5578          * processing in-line, then handling the 'last ptype' for the whole
5579          * sublist.  This can't cause out-of-order delivery to any single ptype,
5580          * because the 'last ptype' must be constant across the sublist, and all
5581          * other ptypes are handled per-packet.
5582          */
5583         /* Current (common) ptype of sublist */
5584         struct packet_type *pt_curr = NULL;
5585         /* Current (common) orig_dev of sublist */
5586         struct net_device *od_curr = NULL;
5587         struct list_head sublist;
5588         struct sk_buff *skb, *next;
5589
5590         INIT_LIST_HEAD(&sublist);
5591         list_for_each_entry_safe(skb, next, head, list) {
5592                 struct net_device *orig_dev = skb->dev;
5593                 struct packet_type *pt_prev = NULL;
5594
5595                 skb_list_del_init(skb);
5596                 __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5597                 if (!pt_prev)
5598                         continue;
5599                 if (pt_curr != pt_prev || od_curr != orig_dev) {
5600                         /* dispatch old sublist */
5601                         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5602                         /* start new sublist */
5603                         INIT_LIST_HEAD(&sublist);
5604                         pt_curr = pt_prev;
5605                         od_curr = orig_dev;
5606                 }
5607                 list_add_tail(&skb->list, &sublist);
5608         }
5609
5610         /* dispatch final sublist */
5611         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5612 }
5613
5614 static int __netif_receive_skb(struct sk_buff *skb)
5615 {
5616         int ret;
5617
5618         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5619                 unsigned int noreclaim_flag;
5620
5621                 /*
5622                  * PFMEMALLOC skbs are special, they should
5623                  * - be delivered to SOCK_MEMALLOC sockets only
5624                  * - stay away from userspace
5625                  * - have bounded memory usage
5626                  *
5627                  * Use PF_MEMALLOC as this saves us from propagating the allocation
5628                  * context down to all allocation sites.
5629                  */
5630                 noreclaim_flag = memalloc_noreclaim_save();
5631                 ret = __netif_receive_skb_one_core(skb, true);
5632                 memalloc_noreclaim_restore(noreclaim_flag);
5633         } else
5634                 ret = __netif_receive_skb_one_core(skb, false);
5635
5636         return ret;
5637 }
5638
5639 static void __netif_receive_skb_list(struct list_head *head)
5640 {
5641         unsigned long noreclaim_flag = 0;
5642         struct sk_buff *skb, *next;
5643         bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5644
5645         list_for_each_entry_safe(skb, next, head, list) {
5646                 if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5647                         struct list_head sublist;
5648
5649                         /* Handle the previous sublist */
5650                         list_cut_before(&sublist, head, &skb->list);
5651                         if (!list_empty(&sublist))
5652                                 __netif_receive_skb_list_core(&sublist, pfmemalloc);
5653                         pfmemalloc = !pfmemalloc;
5654                         /* See comments in __netif_receive_skb */
5655                         if (pfmemalloc)
5656                                 noreclaim_flag = memalloc_noreclaim_save();
5657                         else
5658                                 memalloc_noreclaim_restore(noreclaim_flag);
5659                 }
5660         }
5661         /* Handle the remaining sublist */
5662         if (!list_empty(head))
5663                 __netif_receive_skb_list_core(head, pfmemalloc);
5664         /* Restore pflags */
5665         if (pfmemalloc)
5666                 memalloc_noreclaim_restore(noreclaim_flag);
5667 }
5668
5669 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5670 {
5671         struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5672         struct bpf_prog *new = xdp->prog;
5673         int ret = 0;
5674
5675         switch (xdp->command) {
5676         case XDP_SETUP_PROG:
5677                 rcu_assign_pointer(dev->xdp_prog, new);
5678                 if (old)
5679                         bpf_prog_put(old);
5680
5681                 if (old && !new) {
5682                         static_branch_dec(&generic_xdp_needed_key);
5683                 } else if (new && !old) {
5684                         static_branch_inc(&generic_xdp_needed_key);
5685                         dev_disable_lro(dev);
5686                         dev_disable_gro_hw(dev);
5687                 }
5688                 break;
5689
5690         default:
5691                 ret = -EINVAL;
5692                 break;
5693         }
5694
5695         return ret;
5696 }
5697
5698 static int netif_receive_skb_internal(struct sk_buff *skb)
5699 {
5700         int ret;
5701
5702         net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5703
5704         if (skb_defer_rx_timestamp(skb))
5705                 return NET_RX_SUCCESS;
5706
5707         rcu_read_lock();
5708 #ifdef CONFIG_RPS
5709         if (static_branch_unlikely(&rps_needed)) {
5710                 struct rps_dev_flow voidflow, *rflow = &voidflow;
5711                 int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5712
5713                 if (cpu >= 0) {
5714                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5715                         rcu_read_unlock();
5716                         return ret;
5717                 }
5718         }
5719 #endif
5720         ret = __netif_receive_skb(skb);
5721         rcu_read_unlock();
5722         return ret;
5723 }
5724
5725 void netif_receive_skb_list_internal(struct list_head *head)
5726 {
5727         struct sk_buff *skb, *next;
5728         struct list_head sublist;
5729
5730         INIT_LIST_HEAD(&sublist);
5731         list_for_each_entry_safe(skb, next, head, list) {
5732                 net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5733                 skb_list_del_init(skb);
5734                 if (!skb_defer_rx_timestamp(skb))
5735                         list_add_tail(&skb->list, &sublist);
5736         }
5737         list_splice_init(&sublist, head);
5738
5739         rcu_read_lock();
5740 #ifdef CONFIG_RPS
5741         if (static_branch_unlikely(&rps_needed)) {
5742                 list_for_each_entry_safe(skb, next, head, list) {
5743                         struct rps_dev_flow voidflow, *rflow = &voidflow;
5744                         int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5745
5746                         if (cpu >= 0) {
5747                                 /* Will be handled, remove from list */
5748                                 skb_list_del_init(skb);
5749                                 enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5750                         }
5751                 }
5752         }
5753 #endif
5754         __netif_receive_skb_list(head);
5755         rcu_read_unlock();
5756 }
5757
5758 /**
5759  *      netif_receive_skb - process receive buffer from network
5760  *      @skb: buffer to process
5761  *
5762  *      netif_receive_skb() is the main receive data processing function.
5763  *      It always succeeds. The buffer may be dropped during processing
5764  *      for congestion control or by the protocol layers.
5765  *
5766  *      This function may only be called from softirq context and interrupts
5767  *      should be enabled.
5768  *
5769  *      Return values (usually ignored):
5770  *      NET_RX_SUCCESS: no congestion
5771  *      NET_RX_DROP: packet was dropped
5772  */
5773 int netif_receive_skb(struct sk_buff *skb)
5774 {
5775         int ret;
5776
5777         trace_netif_receive_skb_entry(skb);
5778
5779         ret = netif_receive_skb_internal(skb);
5780         trace_netif_receive_skb_exit(ret);
5781
5782         return ret;
5783 }
5784 EXPORT_SYMBOL(netif_receive_skb);
5785
5786 /**
5787  *      netif_receive_skb_list - process many receive buffers from network
5788  *      @head: list of skbs to process.
5789  *
5790  *      Since return value of netif_receive_skb() is normally ignored, and
5791  *      wouldn't be meaningful for a list, this function returns void.
5792  *
5793  *      This function may only be called from softirq context and interrupts
5794  *      should be enabled.
5795  */
5796 void netif_receive_skb_list(struct list_head *head)
5797 {
5798         struct sk_buff *skb;
5799
5800         if (list_empty(head))
5801                 return;
5802         if (trace_netif_receive_skb_list_entry_enabled()) {
5803                 list_for_each_entry(skb, head, list)
5804                         trace_netif_receive_skb_list_entry(skb);
5805         }
5806         netif_receive_skb_list_internal(head);
5807         trace_netif_receive_skb_list_exit(0);
5808 }
5809 EXPORT_SYMBOL(netif_receive_skb_list);
5810
5811 static DEFINE_PER_CPU(struct work_struct, flush_works);
5812
5813 /* Network device is going away, flush any packets still pending */
5814 static void flush_backlog(struct work_struct *work)
5815 {
5816         struct sk_buff *skb, *tmp;
5817         struct softnet_data *sd;
5818
5819         local_bh_disable();
5820         sd = this_cpu_ptr(&softnet_data);
5821
5822         rps_lock_irq_disable(sd);
5823         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5824                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5825                         __skb_unlink(skb, &sd->input_pkt_queue);
5826                         dev_kfree_skb_irq(skb);
5827                         input_queue_head_incr(sd);
5828                 }
5829         }
5830         rps_unlock_irq_enable(sd);
5831
5832         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5833                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5834                         __skb_unlink(skb, &sd->process_queue);
5835                         kfree_skb(skb);
5836                         input_queue_head_incr(sd);
5837                 }
5838         }
5839         local_bh_enable();
5840 }
5841
5842 static bool flush_required(int cpu)
5843 {
5844 #if IS_ENABLED(CONFIG_RPS)
5845         struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5846         bool do_flush;
5847
5848         rps_lock_irq_disable(sd);
5849
5850         /* as insertion into process_queue happens with the rps lock held,
5851          * process_queue access may race only with dequeue
5852          */
5853         do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5854                    !skb_queue_empty_lockless(&sd->process_queue);
5855         rps_unlock_irq_enable(sd);
5856
5857         return do_flush;
5858 #endif
5859         /* without RPS we can't safely check input_pkt_queue: during a
5860          * concurrent remote skb_queue_splice() we can detect as empty both
5861          * input_pkt_queue and process_queue even if the latter could end-up
5862          * containing a lot of packets.
5863          */
5864         return true;
5865 }
5866
5867 static void flush_all_backlogs(void)
5868 {
5869         static cpumask_t flush_cpus;
5870         unsigned int cpu;
5871
5872         /* since we are under rtnl lock protection we can use static data
5873          * for the cpumask and avoid allocating on stack the possibly
5874          * large mask
5875          */
5876         ASSERT_RTNL();
5877
5878         cpus_read_lock();
5879
5880         cpumask_clear(&flush_cpus);
5881         for_each_online_cpu(cpu) {
5882                 if (flush_required(cpu)) {
5883                         queue_work_on(cpu, system_highpri_wq,
5884                                       per_cpu_ptr(&flush_works, cpu));
5885                         cpumask_set_cpu(cpu, &flush_cpus);
5886                 }
5887         }
5888
5889         /* we can have in flight packet[s] on the cpus we are not flushing,
5890          * synchronize_net() in unregister_netdevice_many() will take care of
5891          * them
5892          */
5893         for_each_cpu(cpu, &flush_cpus)
5894                 flush_work(per_cpu_ptr(&flush_works, cpu));
5895
5896         cpus_read_unlock();
5897 }
5898
5899 static void net_rps_send_ipi(struct softnet_data *remsd)
5900 {
5901 #ifdef CONFIG_RPS
5902         while (remsd) {
5903                 struct softnet_data *next = remsd->rps_ipi_next;
5904
5905                 if (cpu_online(remsd->cpu))
5906                         smp_call_function_single_async(remsd->cpu, &remsd->csd);
5907                 remsd = next;
5908         }
5909 #endif
5910 }
5911
5912 /*
5913  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5914  * Note: called with local irq disabled, but exits with local irq enabled.
5915  */
5916 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5917 {
5918 #ifdef CONFIG_RPS
5919         struct softnet_data *remsd = sd->rps_ipi_list;
5920
5921         if (remsd) {
5922                 sd->rps_ipi_list = NULL;
5923
5924                 local_irq_enable();
5925
5926                 /* Send pending IPI's to kick RPS processing on remote cpus. */
5927                 net_rps_send_ipi(remsd);
5928         } else
5929 #endif
5930                 local_irq_enable();
5931 }
5932
5933 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5934 {
5935 #ifdef CONFIG_RPS
5936         return sd->rps_ipi_list != NULL;
5937 #else
5938         return false;
5939 #endif
5940 }
5941
5942 static int process_backlog(struct napi_struct *napi, int quota)
5943 {
5944         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5945         bool again = true;
5946         int work = 0;
5947
5948         /* Check if we have pending ipi, its better to send them now,
5949          * not waiting net_rx_action() end.
5950          */
5951         if (sd_has_rps_ipi_waiting(sd)) {
5952                 local_irq_disable();
5953                 net_rps_action_and_irq_enable(sd);
5954         }
5955
5956         napi->weight = READ_ONCE(dev_rx_weight);
5957         while (again) {
5958                 struct sk_buff *skb;
5959
5960                 while ((skb = __skb_dequeue(&sd->process_queue))) {
5961                         rcu_read_lock();
5962                         __netif_receive_skb(skb);
5963                         rcu_read_unlock();
5964                         input_queue_head_incr(sd);
5965                         if (++work >= quota)
5966                                 return work;
5967
5968                 }
5969
5970                 rps_lock_irq_disable(sd);
5971                 if (skb_queue_empty(&sd->input_pkt_queue)) {
5972                         /*
5973                          * Inline a custom version of __napi_complete().
5974                          * only current cpu owns and manipulates this napi,
5975                          * and NAPI_STATE_SCHED is the only possible flag set
5976                          * on backlog.
5977                          * We can use a plain write instead of clear_bit(),
5978                          * and we dont need an smp_mb() memory barrier.
5979                          */
5980                         napi->state = 0;
5981                         again = false;
5982                 } else {
5983                         skb_queue_splice_tail_init(&sd->input_pkt_queue,
5984                                                    &sd->process_queue);
5985                 }
5986                 rps_unlock_irq_enable(sd);
5987         }
5988
5989         return work;
5990 }
5991
5992 /**
5993  * __napi_schedule - schedule for receive
5994  * @n: entry to schedule
5995  *
5996  * The entry's receive function will be scheduled to run.
5997  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5998  */
5999 void __napi_schedule(struct napi_struct *n)
6000 {
6001         unsigned long flags;
6002
6003         local_irq_save(flags);
6004         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
6005         local_irq_restore(flags);
6006 }
6007 EXPORT_SYMBOL(__napi_schedule);
6008
6009 /**
6010  *      napi_schedule_prep - check if napi can be scheduled
6011  *      @n: napi context
6012  *
6013  * Test if NAPI routine is already running, and if not mark
6014  * it as running.  This is used as a condition variable to
6015  * insure only one NAPI poll instance runs.  We also make
6016  * sure there is no pending NAPI disable.
6017  */
6018 bool napi_schedule_prep(struct napi_struct *n)
6019 {
6020         unsigned long new, val = READ_ONCE(n->state);
6021
6022         do {
6023                 if (unlikely(val & NAPIF_STATE_DISABLE))
6024                         return false;
6025                 new = val | NAPIF_STATE_SCHED;
6026
6027                 /* Sets STATE_MISSED bit if STATE_SCHED was already set
6028                  * This was suggested by Alexander Duyck, as compiler
6029                  * emits better code than :
6030                  * if (val & NAPIF_STATE_SCHED)
6031                  *     new |= NAPIF_STATE_MISSED;
6032                  */
6033                 new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6034                                                    NAPIF_STATE_MISSED;
6035         } while (!try_cmpxchg(&n->state, &val, new));
6036
6037         return !(val & NAPIF_STATE_SCHED);
6038 }
6039 EXPORT_SYMBOL(napi_schedule_prep);
6040
6041 /**
6042  * __napi_schedule_irqoff - schedule for receive
6043  * @n: entry to schedule
6044  *
6045  * Variant of __napi_schedule() assuming hard irqs are masked.
6046  *
6047  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6048  * because the interrupt disabled assumption might not be true
6049  * due to force-threaded interrupts and spinlock substitution.
6050  */
6051 void __napi_schedule_irqoff(struct napi_struct *n)
6052 {
6053         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6054                 ____napi_schedule(this_cpu_ptr(&softnet_data), n);
6055         else
6056                 __napi_schedule(n);
6057 }
6058 EXPORT_SYMBOL(__napi_schedule_irqoff);
6059
6060 bool napi_complete_done(struct napi_struct *n, int work_done)
6061 {
6062         unsigned long flags, val, new, timeout = 0;
6063         bool ret = true;
6064
6065         /*
6066          * 1) Don't let napi dequeue from the cpu poll list
6067          *    just in case its running on a different cpu.
6068          * 2) If we are busy polling, do nothing here, we have
6069          *    the guarantee we will be called later.
6070          */
6071         if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6072                                  NAPIF_STATE_IN_BUSY_POLL)))
6073                 return false;
6074
6075         if (work_done) {
6076                 if (n->gro_bitmask)
6077                         timeout = READ_ONCE(n->dev->gro_flush_timeout);
6078                 n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6079         }
6080         if (n->defer_hard_irqs_count > 0) {
6081                 n->defer_hard_irqs_count--;
6082                 timeout = READ_ONCE(n->dev->gro_flush_timeout);
6083                 if (timeout)
6084                         ret = false;
6085         }
6086         if (n->gro_bitmask) {
6087                 /* When the NAPI instance uses a timeout and keeps postponing
6088                  * it, we need to bound somehow the time packets are kept in
6089                  * the GRO layer
6090                  */
6091                 napi_gro_flush(n, !!timeout);
6092         }
6093
6094         gro_normal_list(n);
6095
6096         if (unlikely(!list_empty(&n->poll_list))) {
6097                 /* If n->poll_list is not empty, we need to mask irqs */
6098                 local_irq_save(flags);
6099                 list_del_init(&n->poll_list);
6100                 local_irq_restore(flags);
6101         }
6102         WRITE_ONCE(n->list_owner, -1);
6103
6104         val = READ_ONCE(n->state);
6105         do {
6106                 WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6107
6108                 new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6109                               NAPIF_STATE_SCHED_THREADED |
6110                               NAPIF_STATE_PREFER_BUSY_POLL);
6111
6112                 /* If STATE_MISSED was set, leave STATE_SCHED set,
6113                  * because we will call napi->poll() one more time.
6114                  * This C code was suggested by Alexander Duyck to help gcc.
6115                  */
6116                 new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6117                                                     NAPIF_STATE_SCHED;
6118         } while (!try_cmpxchg(&n->state, &val, new));
6119
6120         if (unlikely(val & NAPIF_STATE_MISSED)) {
6121                 __napi_schedule(n);
6122                 return false;
6123         }
6124
6125         if (timeout)
6126                 hrtimer_start(&n->timer, ns_to_ktime(timeout),
6127                               HRTIMER_MODE_REL_PINNED);
6128         return ret;
6129 }
6130 EXPORT_SYMBOL(napi_complete_done);
6131
6132 /* must be called under rcu_read_lock(), as we dont take a reference */
6133 static struct napi_struct *napi_by_id(unsigned int napi_id)
6134 {
6135         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6136         struct napi_struct *napi;
6137
6138         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6139                 if (napi->napi_id == napi_id)
6140                         return napi;
6141
6142         return NULL;
6143 }
6144
6145 #if defined(CONFIG_NET_RX_BUSY_POLL)
6146
6147 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6148 {
6149         if (!skip_schedule) {
6150                 gro_normal_list(napi);
6151                 __napi_schedule(napi);
6152                 return;
6153         }
6154
6155         if (napi->gro_bitmask) {
6156                 /* flush too old packets
6157                  * If HZ < 1000, flush all packets.
6158                  */
6159                 napi_gro_flush(napi, HZ >= 1000);
6160         }
6161
6162         gro_normal_list(napi);
6163         clear_bit(NAPI_STATE_SCHED, &napi->state);
6164 }
6165
6166 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6167                            u16 budget)
6168 {
6169         bool skip_schedule = false;
6170         unsigned long timeout;
6171         int rc;
6172
6173         /* Busy polling means there is a high chance device driver hard irq
6174          * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6175          * set in napi_schedule_prep().
6176          * Since we are about to call napi->poll() once more, we can safely
6177          * clear NAPI_STATE_MISSED.
6178          *
6179          * Note: x86 could use a single "lock and ..." instruction
6180          * to perform these two clear_bit()
6181          */
6182         clear_bit(NAPI_STATE_MISSED, &napi->state);
6183         clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6184
6185         local_bh_disable();
6186
6187         if (prefer_busy_poll) {
6188                 napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6189                 timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6190                 if (napi->defer_hard_irqs_count && timeout) {
6191                         hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6192                         skip_schedule = true;
6193                 }
6194         }
6195
6196         /* All we really want here is to re-enable device interrupts.
6197          * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6198          */
6199         rc = napi->poll(napi, budget);
6200         /* We can't gro_normal_list() here, because napi->poll() might have
6201          * rearmed the napi (napi_complete_done()) in which case it could
6202          * already be running on another CPU.
6203          */
6204         trace_napi_poll(napi, rc, budget);
6205         netpoll_poll_unlock(have_poll_lock);
6206         if (rc == budget)
6207                 __busy_poll_stop(napi, skip_schedule);
6208         local_bh_enable();
6209 }
6210
6211 void napi_busy_loop(unsigned int napi_id,
6212                     bool (*loop_end)(void *, unsigned long),
6213                     void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6214 {
6215         unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6216         int (*napi_poll)(struct napi_struct *napi, int budget);
6217         void *have_poll_lock = NULL;
6218         struct napi_struct *napi;
6219
6220 restart:
6221         napi_poll = NULL;
6222
6223         rcu_read_lock();
6224
6225         napi = napi_by_id(napi_id);
6226         if (!napi)
6227                 goto out;
6228
6229         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6230                 preempt_disable();
6231         for (;;) {
6232                 int work = 0;
6233
6234                 local_bh_disable();
6235                 if (!napi_poll) {
6236                         unsigned long val = READ_ONCE(napi->state);
6237
6238                         /* If multiple threads are competing for this napi,
6239                          * we avoid dirtying napi->state as much as we can.
6240                          */
6241                         if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6242                                    NAPIF_STATE_IN_BUSY_POLL)) {
6243                                 if (prefer_busy_poll)
6244                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6245                                 goto count;
6246                         }
6247                         if (cmpxchg(&napi->state, val,
6248                                     val | NAPIF_STATE_IN_BUSY_POLL |
6249                                           NAPIF_STATE_SCHED) != val) {
6250                                 if (prefer_busy_poll)
6251                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6252                                 goto count;
6253                         }
6254                         have_poll_lock = netpoll_poll_lock(napi);
6255                         napi_poll = napi->poll;
6256                 }
6257                 work = napi_poll(napi, budget);
6258                 trace_napi_poll(napi, work, budget);
6259                 gro_normal_list(napi);
6260 count:
6261                 if (work > 0)
6262                         __NET_ADD_STATS(dev_net(napi->dev),
6263                                         LINUX_MIB_BUSYPOLLRXPACKETS, work);
6264                 local_bh_enable();
6265
6266                 if (!loop_end || loop_end(loop_end_arg, start_time))
6267                         break;
6268
6269                 if (unlikely(need_resched())) {
6270                         if (napi_poll)
6271                                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6272                         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6273                                 preempt_enable();
6274                         rcu_read_unlock();
6275                         cond_resched();
6276                         if (loop_end(loop_end_arg, start_time))
6277                                 return;
6278                         goto restart;
6279                 }
6280                 cpu_relax();
6281         }
6282         if (napi_poll)
6283                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6284         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6285                 preempt_enable();
6286 out:
6287         rcu_read_unlock();
6288 }
6289 EXPORT_SYMBOL(napi_busy_loop);
6290
6291 #endif /* CONFIG_NET_RX_BUSY_POLL */
6292
6293 static void napi_hash_add(struct napi_struct *napi)
6294 {
6295         if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6296                 return;
6297
6298         spin_lock(&napi_hash_lock);
6299
6300         /* 0..NR_CPUS range is reserved for sender_cpu use */
6301         do {
6302                 if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6303                         napi_gen_id = MIN_NAPI_ID;
6304         } while (napi_by_id(napi_gen_id));
6305         napi->napi_id = napi_gen_id;
6306
6307         hlist_add_head_rcu(&napi->napi_hash_node,
6308                            &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6309
6310         spin_unlock(&napi_hash_lock);
6311 }
6312
6313 /* Warning : caller is responsible to make sure rcu grace period
6314  * is respected before freeing memory containing @napi
6315  */
6316 static void napi_hash_del(struct napi_struct *napi)
6317 {
6318         spin_lock(&napi_hash_lock);
6319
6320         hlist_del_init_rcu(&napi->napi_hash_node);
6321
6322         spin_unlock(&napi_hash_lock);
6323 }
6324
6325 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6326 {
6327         struct napi_struct *napi;
6328
6329         napi = container_of(timer, struct napi_struct, timer);
6330
6331         /* Note : we use a relaxed variant of napi_schedule_prep() not setting
6332          * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6333          */
6334         if (!napi_disable_pending(napi) &&
6335             !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6336                 clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6337                 __napi_schedule_irqoff(napi);
6338         }
6339
6340         return HRTIMER_NORESTART;
6341 }
6342
6343 static void init_gro_hash(struct napi_struct *napi)
6344 {
6345         int i;
6346
6347         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6348                 INIT_LIST_HEAD(&napi->gro_hash[i].list);
6349                 napi->gro_hash[i].count = 0;
6350         }
6351         napi->gro_bitmask = 0;
6352 }
6353
6354 int dev_set_threaded(struct net_device *dev, bool threaded)
6355 {
6356         struct napi_struct *napi;
6357         int err = 0;
6358
6359         if (dev->threaded == threaded)
6360                 return 0;
6361
6362         if (threaded) {
6363                 list_for_each_entry(napi, &dev->napi_list, dev_list) {
6364                         if (!napi->thread) {
6365                                 err = napi_kthread_create(napi);
6366                                 if (err) {
6367                                         threaded = false;
6368                                         break;
6369                                 }
6370                         }
6371                 }
6372         }
6373
6374         dev->threaded = threaded;
6375
6376         /* Make sure kthread is created before THREADED bit
6377          * is set.
6378          */
6379         smp_mb__before_atomic();
6380
6381         /* Setting/unsetting threaded mode on a napi might not immediately
6382          * take effect, if the current napi instance is actively being
6383          * polled. In this case, the switch between threaded mode and
6384          * softirq mode will happen in the next round of napi_schedule().
6385          * This should not cause hiccups/stalls to the live traffic.
6386          */
6387         list_for_each_entry(napi, &dev->napi_list, dev_list)
6388                 assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
6389
6390         return err;
6391 }
6392 EXPORT_SYMBOL(dev_set_threaded);
6393
6394 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6395                            int (*poll)(struct napi_struct *, int), int weight)
6396 {
6397         if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6398                 return;
6399
6400         INIT_LIST_HEAD(&napi->poll_list);
6401         INIT_HLIST_NODE(&napi->napi_hash_node);
6402         hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6403         napi->timer.function = napi_watchdog;
6404         init_gro_hash(napi);
6405         napi->skb = NULL;
6406         INIT_LIST_HEAD(&napi->rx_list);
6407         napi->rx_count = 0;
6408         napi->poll = poll;
6409         if (weight > NAPI_POLL_WEIGHT)
6410                 netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6411                                 weight);
6412         napi->weight = weight;
6413         napi->dev = dev;
6414 #ifdef CONFIG_NETPOLL
6415         napi->poll_owner = -1;
6416 #endif
6417         napi->list_owner = -1;
6418         set_bit(NAPI_STATE_SCHED, &napi->state);
6419         set_bit(NAPI_STATE_NPSVC, &napi->state);
6420         list_add_rcu(&napi->dev_list, &dev->napi_list);
6421         napi_hash_add(napi);
6422         napi_get_frags_check(napi);
6423         /* Create kthread for this napi if dev->threaded is set.
6424          * Clear dev->threaded if kthread creation failed so that
6425          * threaded mode will not be enabled in napi_enable().
6426          */
6427         if (dev->threaded && napi_kthread_create(napi))
6428                 dev->threaded = 0;
6429 }
6430 EXPORT_SYMBOL(netif_napi_add_weight);
6431
6432 void napi_disable(struct napi_struct *n)
6433 {
6434         unsigned long val, new;
6435
6436         might_sleep();
6437         set_bit(NAPI_STATE_DISABLE, &n->state);
6438
6439         val = READ_ONCE(n->state);
6440         do {
6441                 while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6442                         usleep_range(20, 200);
6443                         val = READ_ONCE(n->state);
6444                 }
6445
6446                 new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6447                 new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6448         } while (!try_cmpxchg(&n->state, &val, new));
6449
6450         hrtimer_cancel(&n->timer);
6451
6452         clear_bit(NAPI_STATE_DISABLE, &n->state);
6453 }
6454 EXPORT_SYMBOL(napi_disable);
6455
6456 /**
6457  *      napi_enable - enable NAPI scheduling
6458  *      @n: NAPI context
6459  *
6460  * Resume NAPI from being scheduled on this context.
6461  * Must be paired with napi_disable.
6462  */
6463 void napi_enable(struct napi_struct *n)
6464 {
6465         unsigned long new, val = READ_ONCE(n->state);
6466
6467         do {
6468                 BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6469
6470                 new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6471                 if (n->dev->threaded && n->thread)
6472                         new |= NAPIF_STATE_THREADED;
6473         } while (!try_cmpxchg(&n->state, &val, new));
6474 }
6475 EXPORT_SYMBOL(napi_enable);
6476
6477 static void flush_gro_hash(struct napi_struct *napi)
6478 {
6479         int i;
6480
6481         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6482                 struct sk_buff *skb, *n;
6483
6484                 list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6485                         kfree_skb(skb);
6486                 napi->gro_hash[i].count = 0;
6487         }
6488 }
6489
6490 /* Must be called in process context */
6491 void __netif_napi_del(struct napi_struct *napi)
6492 {
6493         if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6494                 return;
6495
6496         napi_hash_del(napi);
6497         list_del_rcu(&napi->dev_list);
6498         napi_free_frags(napi);
6499
6500         flush_gro_hash(napi);
6501         napi->gro_bitmask = 0;
6502
6503         if (napi->thread) {
6504                 kthread_stop(napi->thread);
6505                 napi->thread = NULL;
6506         }
6507 }
6508 EXPORT_SYMBOL(__netif_napi_del);
6509
6510 static int __napi_poll(struct napi_struct *n, bool *repoll)
6511 {
6512         int work, weight;
6513
6514         weight = n->weight;
6515
6516         /* This NAPI_STATE_SCHED test is for avoiding a race
6517          * with netpoll's poll_napi().  Only the entity which
6518          * obtains the lock and sees NAPI_STATE_SCHED set will
6519          * actually make the ->poll() call.  Therefore we avoid
6520          * accidentally calling ->poll() when NAPI is not scheduled.
6521          */
6522         work = 0;
6523         if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6524                 work = n->poll(n, weight);
6525                 trace_napi_poll(n, work, weight);
6526         }
6527
6528         if (unlikely(work > weight))
6529                 netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6530                                 n->poll, work, weight);
6531
6532         if (likely(work < weight))
6533                 return work;
6534
6535         /* Drivers must not modify the NAPI state if they
6536          * consume the entire weight.  In such cases this code
6537          * still "owns" the NAPI instance and therefore can
6538          * move the instance around on the list at-will.
6539          */
6540         if (unlikely(napi_disable_pending(n))) {
6541                 napi_complete(n);
6542                 return work;
6543         }
6544
6545         /* The NAPI context has more processing work, but busy-polling
6546          * is preferred. Exit early.
6547          */
6548         if (napi_prefer_busy_poll(n)) {
6549                 if (napi_complete_done(n, work)) {
6550                         /* If timeout is not set, we need to make sure
6551                          * that the NAPI is re-scheduled.
6552                          */
6553                         napi_schedule(n);
6554                 }
6555                 return work;
6556         }
6557
6558         if (n->gro_bitmask) {
6559                 /* flush too old packets
6560                  * If HZ < 1000, flush all packets.
6561                  */
6562                 napi_gro_flush(n, HZ >= 1000);
6563         }
6564
6565         gro_normal_list(n);
6566
6567         /* Some drivers may have called napi_schedule
6568          * prior to exhausting their budget.
6569          */
6570         if (unlikely(!list_empty(&n->poll_list))) {
6571                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6572                              n->dev ? n->dev->name : "backlog");
6573                 return work;
6574         }
6575
6576         *repoll = true;
6577
6578         return work;
6579 }
6580
6581 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6582 {
6583         bool do_repoll = false;
6584         void *have;
6585         int work;
6586
6587         list_del_init(&n->poll_list);
6588
6589         have = netpoll_poll_lock(n);
6590
6591         work = __napi_poll(n, &do_repoll);
6592
6593         if (do_repoll)
6594                 list_add_tail(&n->poll_list, repoll);
6595
6596         netpoll_poll_unlock(have);
6597
6598         return work;
6599 }
6600
6601 static int napi_thread_wait(struct napi_struct *napi)
6602 {
6603         bool woken = false;
6604
6605         set_current_state(TASK_INTERRUPTIBLE);
6606
6607         while (!kthread_should_stop()) {
6608                 /* Testing SCHED_THREADED bit here to make sure the current
6609                  * kthread owns this napi and could poll on this napi.
6610                  * Testing SCHED bit is not enough because SCHED bit might be
6611                  * set by some other busy poll thread or by napi_disable().
6612                  */
6613                 if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6614                         WARN_ON(!list_empty(&napi->poll_list));
6615                         __set_current_state(TASK_RUNNING);
6616                         return 0;
6617                 }
6618
6619                 schedule();
6620                 /* woken being true indicates this thread owns this napi. */
6621                 woken = true;
6622                 set_current_state(TASK_INTERRUPTIBLE);
6623         }
6624         __set_current_state(TASK_RUNNING);
6625
6626         return -1;
6627 }
6628
6629 static void skb_defer_free_flush(struct softnet_data *sd)
6630 {
6631         struct sk_buff *skb, *next;
6632
6633         /* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6634         if (!READ_ONCE(sd->defer_list))
6635                 return;
6636
6637         spin_lock(&sd->defer_lock);
6638         skb = sd->defer_list;
6639         sd->defer_list = NULL;
6640         sd->defer_count = 0;
6641         spin_unlock(&sd->defer_lock);
6642
6643         while (skb != NULL) {
6644                 next = skb->next;
6645                 napi_consume_skb(skb, 1);
6646                 skb = next;
6647         }
6648 }
6649
6650 static int napi_threaded_poll(void *data)
6651 {
6652         struct napi_struct *napi = data;
6653         struct softnet_data *sd;
6654         void *have;
6655
6656         while (!napi_thread_wait(napi)) {
6657                 for (;;) {
6658                         bool repoll = false;
6659
6660                         local_bh_disable();
6661                         sd = this_cpu_ptr(&softnet_data);
6662                         sd->in_napi_threaded_poll = true;
6663
6664                         have = netpoll_poll_lock(napi);
6665                         __napi_poll(napi, &repoll);
6666                         netpoll_poll_unlock(have);
6667
6668                         sd->in_napi_threaded_poll = false;
6669                         barrier();
6670
6671                         if (sd_has_rps_ipi_waiting(sd)) {
6672                                 local_irq_disable();
6673                                 net_rps_action_and_irq_enable(sd);
6674                         }
6675                         skb_defer_free_flush(sd);
6676                         local_bh_enable();
6677
6678                         if (!repoll)
6679                                 break;
6680
6681                         cond_resched();
6682                 }
6683         }
6684         return 0;
6685 }
6686
6687 static __latent_entropy void net_rx_action(struct softirq_action *h)
6688 {
6689         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6690         unsigned long time_limit = jiffies +
6691                 usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6692         int budget = READ_ONCE(netdev_budget);
6693         LIST_HEAD(list);
6694         LIST_HEAD(repoll);
6695
6696 start:
6697         sd->in_net_rx_action = true;
6698         local_irq_disable();
6699         list_splice_init(&sd->poll_list, &list);
6700         local_irq_enable();
6701
6702         for (;;) {
6703                 struct napi_struct *n;
6704
6705                 skb_defer_free_flush(sd);
6706
6707                 if (list_empty(&list)) {
6708                         if (list_empty(&repoll)) {
6709                                 sd->in_net_rx_action = false;
6710                                 barrier();
6711                                 /* We need to check if ____napi_schedule()
6712                                  * had refilled poll_list while
6713                                  * sd->in_net_rx_action was true.
6714                                  */
6715                                 if (!list_empty(&sd->poll_list))
6716                                         goto start;
6717                                 if (!sd_has_rps_ipi_waiting(sd))
6718                                         goto end;
6719                         }
6720                         break;
6721                 }
6722
6723                 n = list_first_entry(&list, struct napi_struct, poll_list);
6724                 budget -= napi_poll(n, &repoll);
6725
6726                 /* If softirq window is exhausted then punt.
6727                  * Allow this to run for 2 jiffies since which will allow
6728                  * an average latency of 1.5/HZ.
6729                  */
6730                 if (unlikely(budget <= 0 ||
6731                              time_after_eq(jiffies, time_limit))) {
6732                         sd->time_squeeze++;
6733                         break;
6734                 }
6735         }
6736
6737         local_irq_disable();
6738
6739         list_splice_tail_init(&sd->poll_list, &list);
6740         list_splice_tail(&repoll, &list);
6741         list_splice(&list, &sd->poll_list);
6742         if (!list_empty(&sd->poll_list))
6743                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
6744         else
6745                 sd->in_net_rx_action = false;
6746
6747         net_rps_action_and_irq_enable(sd);
6748 end:;
6749 }
6750
6751 struct netdev_adjacent {
6752         struct net_device *dev;
6753         netdevice_tracker dev_tracker;
6754
6755         /* upper master flag, there can only be one master device per list */
6756         bool master;
6757
6758         /* lookup ignore flag */
6759         bool ignore;
6760
6761         /* counter for the number of times this device was added to us */
6762         u16 ref_nr;
6763
6764         /* private field for the users */
6765         void *private;
6766
6767         struct list_head list;
6768         struct rcu_head rcu;
6769 };
6770
6771 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6772                                                  struct list_head *adj_list)
6773 {
6774         struct netdev_adjacent *adj;
6775
6776         list_for_each_entry(adj, adj_list, list) {
6777                 if (adj->dev == adj_dev)
6778                         return adj;
6779         }
6780         return NULL;
6781 }
6782
6783 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6784                                     struct netdev_nested_priv *priv)
6785 {
6786         struct net_device *dev = (struct net_device *)priv->data;
6787
6788         return upper_dev == dev;
6789 }
6790
6791 /**
6792  * netdev_has_upper_dev - Check if device is linked to an upper device
6793  * @dev: device
6794  * @upper_dev: upper device to check
6795  *
6796  * Find out if a device is linked to specified upper device and return true
6797  * in case it is. Note that this checks only immediate upper device,
6798  * not through a complete stack of devices. The caller must hold the RTNL lock.
6799  */
6800 bool netdev_has_upper_dev(struct net_device *dev,
6801                           struct net_device *upper_dev)
6802 {
6803         struct netdev_nested_priv priv = {
6804                 .data = (void *)upper_dev,
6805         };
6806
6807         ASSERT_RTNL();
6808
6809         return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6810                                              &priv);
6811 }
6812 EXPORT_SYMBOL(netdev_has_upper_dev);
6813
6814 /**
6815  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6816  * @dev: device
6817  * @upper_dev: upper device to check
6818  *
6819  * Find out if a device is linked to specified upper device and return true
6820  * in case it is. Note that this checks the entire upper device chain.
6821  * The caller must hold rcu lock.
6822  */
6823
6824 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6825                                   struct net_device *upper_dev)
6826 {
6827         struct netdev_nested_priv priv = {
6828                 .data = (void *)upper_dev,
6829         };
6830
6831         return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6832                                                &priv);
6833 }
6834 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6835
6836 /**
6837  * netdev_has_any_upper_dev - Check if device is linked to some device
6838  * @dev: device
6839  *
6840  * Find out if a device is linked to an upper device and return true in case
6841  * it is. The caller must hold the RTNL lock.
6842  */
6843 bool netdev_has_any_upper_dev(struct net_device *dev)
6844 {
6845         ASSERT_RTNL();
6846
6847         return !list_empty(&dev->adj_list.upper);
6848 }
6849 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6850
6851 /**
6852  * netdev_master_upper_dev_get - Get master upper device
6853  * @dev: device
6854  *
6855  * Find a master upper device and return pointer to it or NULL in case
6856  * it's not there. The caller must hold the RTNL lock.
6857  */
6858 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6859 {
6860         struct netdev_adjacent *upper;
6861
6862         ASSERT_RTNL();
6863
6864         if (list_empty(&dev->adj_list.upper))
6865                 return NULL;
6866
6867         upper = list_first_entry(&dev->adj_list.upper,
6868                                  struct netdev_adjacent, list);
6869         if (likely(upper->master))
6870                 return upper->dev;
6871         return NULL;
6872 }
6873 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6874
6875 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6876 {
6877         struct netdev_adjacent *upper;
6878
6879         ASSERT_RTNL();
6880
6881         if (list_empty(&dev->adj_list.upper))
6882                 return NULL;
6883
6884         upper = list_first_entry(&dev->adj_list.upper,
6885                                  struct netdev_adjacent, list);
6886         if (likely(upper->master) && !upper->ignore)
6887                 return upper->dev;
6888         return NULL;
6889 }
6890
6891 /**
6892  * netdev_has_any_lower_dev - Check if device is linked to some device
6893  * @dev: device
6894  *
6895  * Find out if a device is linked to a lower device and return true in case
6896  * it is. The caller must hold the RTNL lock.
6897  */
6898 static bool netdev_has_any_lower_dev(struct net_device *dev)
6899 {
6900         ASSERT_RTNL();
6901
6902         return !list_empty(&dev->adj_list.lower);
6903 }
6904
6905 void *netdev_adjacent_get_private(struct list_head *adj_list)
6906 {
6907         struct netdev_adjacent *adj;
6908
6909         adj = list_entry(adj_list, struct netdev_adjacent, list);
6910
6911         return adj->private;
6912 }
6913 EXPORT_SYMBOL(netdev_adjacent_get_private);
6914
6915 /**
6916  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6917  * @dev: device
6918  * @iter: list_head ** of the current position
6919  *
6920  * Gets the next device from the dev's upper list, starting from iter
6921  * position. The caller must hold RCU read lock.
6922  */
6923 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6924                                                  struct list_head **iter)
6925 {
6926         struct netdev_adjacent *upper;
6927
6928         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6929
6930         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6931
6932         if (&upper->list == &dev->adj_list.upper)
6933                 return NULL;
6934
6935         *iter = &upper->list;
6936
6937         return upper->dev;
6938 }
6939 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6940
6941 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6942                                                   struct list_head **iter,
6943                                                   bool *ignore)
6944 {
6945         struct netdev_adjacent *upper;
6946
6947         upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6948
6949         if (&upper->list == &dev->adj_list.upper)
6950                 return NULL;
6951
6952         *iter = &upper->list;
6953         *ignore = upper->ignore;
6954
6955         return upper->dev;
6956 }
6957
6958 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6959                                                     struct list_head **iter)
6960 {
6961         struct netdev_adjacent *upper;
6962
6963         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6964
6965         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6966
6967         if (&upper->list == &dev->adj_list.upper)
6968                 return NULL;
6969
6970         *iter = &upper->list;
6971
6972         return upper->dev;
6973 }
6974
6975 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6976                                        int (*fn)(struct net_device *dev,
6977                                          struct netdev_nested_priv *priv),
6978                                        struct netdev_nested_priv *priv)
6979 {
6980         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6981         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6982         int ret, cur = 0;
6983         bool ignore;
6984
6985         now = dev;
6986         iter = &dev->adj_list.upper;
6987
6988         while (1) {
6989                 if (now != dev) {
6990                         ret = fn(now, priv);
6991                         if (ret)
6992                                 return ret;
6993                 }
6994
6995                 next = NULL;
6996                 while (1) {
6997                         udev = __netdev_next_upper_dev(now, &iter, &ignore);
6998                         if (!udev)
6999                                 break;
7000                         if (ignore)
7001                                 continue;
7002
7003                         next = udev;
7004                         niter = &udev->adj_list.upper;
7005                         dev_stack[cur] = now;
7006                         iter_stack[cur++] = iter;
7007                         break;
7008                 }
7009
7010                 if (!next) {
7011                         if (!cur)
7012                                 return 0;
7013                         next = dev_stack[--cur];
7014                         niter = iter_stack[cur];
7015                 }
7016
7017                 now = next;
7018                 iter = niter;
7019         }
7020
7021         return 0;
7022 }
7023
7024 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
7025                                   int (*fn)(struct net_device *dev,
7026                                             struct netdev_nested_priv *priv),
7027                                   struct netdev_nested_priv *priv)
7028 {
7029         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7030         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7031         int ret, cur = 0;
7032
7033         now = dev;
7034         iter = &dev->adj_list.upper;
7035
7036         while (1) {
7037                 if (now != dev) {
7038                         ret = fn(now, priv);
7039                         if (ret)
7040                                 return ret;
7041                 }
7042
7043                 next = NULL;
7044                 while (1) {
7045                         udev = netdev_next_upper_dev_rcu(now, &iter);
7046                         if (!udev)
7047                                 break;
7048
7049                         next = udev;
7050                         niter = &udev->adj_list.upper;
7051                         dev_stack[cur] = now;
7052                         iter_stack[cur++] = iter;
7053                         break;
7054                 }
7055
7056                 if (!next) {
7057                         if (!cur)
7058                                 return 0;
7059                         next = dev_stack[--cur];
7060                         niter = iter_stack[cur];
7061                 }
7062
7063                 now = next;
7064                 iter = niter;
7065         }
7066
7067         return 0;
7068 }
7069 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7070
7071 static bool __netdev_has_upper_dev(struct net_device *dev,
7072                                    struct net_device *upper_dev)
7073 {
7074         struct netdev_nested_priv priv = {
7075                 .flags = 0,
7076                 .data = (void *)upper_dev,
7077         };
7078
7079         ASSERT_RTNL();
7080
7081         return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7082                                            &priv);
7083 }
7084
7085 /**
7086  * netdev_lower_get_next_private - Get the next ->private from the
7087  *                                 lower neighbour list
7088  * @dev: device
7089  * @iter: list_head ** of the current position
7090  *
7091  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7092  * list, starting from iter position. The caller must hold either hold the
7093  * RTNL lock or its own locking that guarantees that the neighbour lower
7094  * list will remain unchanged.
7095  */
7096 void *netdev_lower_get_next_private(struct net_device *dev,
7097                                     struct list_head **iter)
7098 {
7099         struct netdev_adjacent *lower;
7100
7101         lower = list_entry(*iter, struct netdev_adjacent, list);
7102
7103         if (&lower->list == &dev->adj_list.lower)
7104                 return NULL;
7105
7106         *iter = lower->list.next;
7107
7108         return lower->private;
7109 }
7110 EXPORT_SYMBOL(netdev_lower_get_next_private);
7111
7112 /**
7113  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7114  *                                     lower neighbour list, RCU
7115  *                                     variant
7116  * @dev: device
7117  * @iter: list_head ** of the current position
7118  *
7119  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7120  * list, starting from iter position. The caller must hold RCU read lock.
7121  */
7122 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7123                                         struct list_head **iter)
7124 {
7125         struct netdev_adjacent *lower;
7126
7127         WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7128
7129         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7130
7131         if (&lower->list == &dev->adj_list.lower)
7132                 return NULL;
7133
7134         *iter = &lower->list;
7135
7136         return lower->private;
7137 }
7138 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7139
7140 /**
7141  * netdev_lower_get_next - Get the next device from the lower neighbour
7142  *                         list
7143  * @dev: device
7144  * @iter: list_head ** of the current position
7145  *
7146  * Gets the next netdev_adjacent from the dev's lower neighbour
7147  * list, starting from iter position. The caller must hold RTNL lock or
7148  * its own locking that guarantees that the neighbour lower
7149  * list will remain unchanged.
7150  */
7151 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7152 {
7153         struct netdev_adjacent *lower;
7154
7155         lower = list_entry(*iter, struct netdev_adjacent, list);
7156
7157         if (&lower->list == &dev->adj_list.lower)
7158                 return NULL;
7159
7160         *iter = lower->list.next;
7161
7162         return lower->dev;
7163 }
7164 EXPORT_SYMBOL(netdev_lower_get_next);
7165
7166 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7167                                                 struct list_head **iter)
7168 {
7169         struct netdev_adjacent *lower;
7170
7171         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7172
7173         if (&lower->list == &dev->adj_list.lower)
7174                 return NULL;
7175
7176         *iter = &lower->list;
7177
7178         return lower->dev;
7179 }
7180
7181 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7182                                                   struct list_head **iter,
7183                                                   bool *ignore)
7184 {
7185         struct netdev_adjacent *lower;
7186
7187         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7188
7189         if (&lower->list == &dev->adj_list.lower)
7190                 return NULL;
7191
7192         *iter = &lower->list;
7193         *ignore = lower->ignore;
7194
7195         return lower->dev;
7196 }
7197
7198 int netdev_walk_all_lower_dev(struct net_device *dev,
7199                               int (*fn)(struct net_device *dev,
7200                                         struct netdev_nested_priv *priv),
7201                               struct netdev_nested_priv *priv)
7202 {
7203         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7204         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7205         int ret, cur = 0;
7206
7207         now = dev;
7208         iter = &dev->adj_list.lower;
7209
7210         while (1) {
7211                 if (now != dev) {
7212                         ret = fn(now, priv);
7213                         if (ret)
7214                                 return ret;
7215                 }
7216
7217                 next = NULL;
7218                 while (1) {
7219                         ldev = netdev_next_lower_dev(now, &iter);
7220                         if (!ldev)
7221                                 break;
7222
7223                         next = ldev;
7224                         niter = &ldev->adj_list.lower;
7225                         dev_stack[cur] = now;
7226                         iter_stack[cur++] = iter;
7227                         break;
7228                 }
7229
7230                 if (!next) {
7231                         if (!cur)
7232                                 return 0;
7233                         next = dev_stack[--cur];
7234                         niter = iter_stack[cur];
7235                 }
7236
7237                 now = next;
7238                 iter = niter;
7239         }
7240
7241         return 0;
7242 }
7243 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7244
7245 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7246                                        int (*fn)(struct net_device *dev,
7247                                          struct netdev_nested_priv *priv),
7248                                        struct netdev_nested_priv *priv)
7249 {
7250         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7251         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7252         int ret, cur = 0;
7253         bool ignore;
7254
7255         now = dev;
7256         iter = &dev->adj_list.lower;
7257
7258         while (1) {
7259                 if (now != dev) {
7260                         ret = fn(now, priv);
7261                         if (ret)
7262                                 return ret;
7263                 }
7264
7265                 next = NULL;
7266                 while (1) {
7267                         ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7268                         if (!ldev)
7269                                 break;
7270                         if (ignore)
7271                                 continue;
7272
7273                         next = ldev;
7274                         niter = &ldev->adj_list.lower;
7275                         dev_stack[cur] = now;
7276                         iter_stack[cur++] = iter;
7277                         break;
7278                 }
7279
7280                 if (!next) {
7281                         if (!cur)
7282                                 return 0;
7283                         next = dev_stack[--cur];
7284                         niter = iter_stack[cur];
7285                 }
7286
7287                 now = next;
7288                 iter = niter;
7289         }
7290
7291         return 0;
7292 }
7293
7294 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7295                                              struct list_head **iter)
7296 {
7297         struct netdev_adjacent *lower;
7298
7299         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7300         if (&lower->list == &dev->adj_list.lower)
7301                 return NULL;
7302
7303         *iter = &lower->list;
7304
7305         return lower->dev;
7306 }
7307 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7308
7309 static u8 __netdev_upper_depth(struct net_device *dev)
7310 {
7311         struct net_device *udev;
7312         struct list_head *iter;
7313         u8 max_depth = 0;
7314         bool ignore;
7315
7316         for (iter = &dev->adj_list.upper,
7317              udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7318              udev;
7319              udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7320                 if (ignore)
7321                         continue;
7322                 if (max_depth < udev->upper_level)
7323                         max_depth = udev->upper_level;
7324         }
7325
7326         return max_depth;
7327 }
7328
7329 static u8 __netdev_lower_depth(struct net_device *dev)
7330 {
7331         struct net_device *ldev;
7332         struct list_head *iter;
7333         u8 max_depth = 0;
7334         bool ignore;
7335
7336         for (iter = &dev->adj_list.lower,
7337              ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7338              ldev;
7339              ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7340                 if (ignore)
7341                         continue;
7342                 if (max_depth < ldev->lower_level)
7343                         max_depth = ldev->lower_level;
7344         }
7345
7346         return max_depth;
7347 }
7348
7349 static int __netdev_update_upper_level(struct net_device *dev,
7350                                        struct netdev_nested_priv *__unused)
7351 {
7352         dev->upper_level = __netdev_upper_depth(dev) + 1;
7353         return 0;
7354 }
7355
7356 #ifdef CONFIG_LOCKDEP
7357 static LIST_HEAD(net_unlink_list);
7358
7359 static void net_unlink_todo(struct net_device *dev)
7360 {
7361         if (list_empty(&dev->unlink_list))
7362                 list_add_tail(&dev->unlink_list, &net_unlink_list);
7363 }
7364 #endif
7365
7366 static int __netdev_update_lower_level(struct net_device *dev,
7367                                        struct netdev_nested_priv *priv)
7368 {
7369         dev->lower_level = __netdev_lower_depth(dev) + 1;
7370
7371 #ifdef CONFIG_LOCKDEP
7372         if (!priv)
7373                 return 0;
7374
7375         if (priv->flags & NESTED_SYNC_IMM)
7376                 dev->nested_level = dev->lower_level - 1;
7377         if (priv->flags & NESTED_SYNC_TODO)
7378                 net_unlink_todo(dev);
7379 #endif
7380         return 0;
7381 }
7382
7383 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7384                                   int (*fn)(struct net_device *dev,
7385                                             struct netdev_nested_priv *priv),
7386                                   struct netdev_nested_priv *priv)
7387 {
7388         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7389         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7390         int ret, cur = 0;
7391
7392         now = dev;
7393         iter = &dev->adj_list.lower;
7394
7395         while (1) {
7396                 if (now != dev) {
7397                         ret = fn(now, priv);
7398                         if (ret)
7399                                 return ret;
7400                 }
7401
7402                 next = NULL;
7403                 while (1) {
7404                         ldev = netdev_next_lower_dev_rcu(now, &iter);
7405                         if (!ldev)
7406                                 break;
7407
7408                         next = ldev;
7409                         niter = &ldev->adj_list.lower;
7410                         dev_stack[cur] = now;
7411                         iter_stack[cur++] = iter;
7412                         break;
7413                 }
7414
7415                 if (!next) {
7416                         if (!cur)
7417                                 return 0;
7418                         next = dev_stack[--cur];
7419                         niter = iter_stack[cur];
7420                 }
7421
7422                 now = next;
7423                 iter = niter;
7424         }
7425
7426         return 0;
7427 }
7428 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7429
7430 /**
7431  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7432  *                                     lower neighbour list, RCU
7433  *                                     variant
7434  * @dev: device
7435  *
7436  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7437  * list. The caller must hold RCU read lock.
7438  */
7439 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7440 {
7441         struct netdev_adjacent *lower;
7442
7443         lower = list_first_or_null_rcu(&dev->adj_list.lower,
7444                         struct netdev_adjacent, list);
7445         if (lower)
7446                 return lower->private;
7447         return NULL;
7448 }
7449 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7450
7451 /**
7452  * netdev_master_upper_dev_get_rcu - Get master upper device
7453  * @dev: device
7454  *
7455  * Find a master upper device and return pointer to it or NULL in case
7456  * it's not there. The caller must hold the RCU read lock.
7457  */
7458 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7459 {
7460         struct netdev_adjacent *upper;
7461
7462         upper = list_first_or_null_rcu(&dev->adj_list.upper,
7463                                        struct netdev_adjacent, list);
7464         if (upper && likely(upper->master))
7465                 return upper->dev;
7466         return NULL;
7467 }
7468 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7469
7470 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7471                               struct net_device *adj_dev,
7472                               struct list_head *dev_list)
7473 {
7474         char linkname[IFNAMSIZ+7];
7475
7476         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7477                 "upper_%s" : "lower_%s", adj_dev->name);
7478         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7479                                  linkname);
7480 }
7481 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7482                                char *name,
7483                                struct list_head *dev_list)
7484 {
7485         char linkname[IFNAMSIZ+7];
7486
7487         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7488                 "upper_%s" : "lower_%s", name);
7489         sysfs_remove_link(&(dev->dev.kobj), linkname);
7490 }
7491
7492 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7493                                                  struct net_device *adj_dev,
7494                                                  struct list_head *dev_list)
7495 {
7496         return (dev_list == &dev->adj_list.upper ||
7497                 dev_list == &dev->adj_list.lower) &&
7498                 net_eq(dev_net(dev), dev_net(adj_dev));
7499 }
7500
7501 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7502                                         struct net_device *adj_dev,
7503                                         struct list_head *dev_list,
7504                                         void *private, bool master)
7505 {
7506         struct netdev_adjacent *adj;
7507         int ret;
7508
7509         adj = __netdev_find_adj(adj_dev, dev_list);
7510
7511         if (adj) {
7512                 adj->ref_nr += 1;
7513                 pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7514                          dev->name, adj_dev->name, adj->ref_nr);
7515
7516                 return 0;
7517         }
7518
7519         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7520         if (!adj)
7521                 return -ENOMEM;
7522
7523         adj->dev = adj_dev;
7524         adj->master = master;
7525         adj->ref_nr = 1;
7526         adj->private = private;
7527         adj->ignore = false;
7528         netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7529
7530         pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7531                  dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7532
7533         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7534                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7535                 if (ret)
7536                         goto free_adj;
7537         }
7538
7539         /* Ensure that master link is always the first item in list. */
7540         if (master) {
7541                 ret = sysfs_create_link(&(dev->dev.kobj),
7542                                         &(adj_dev->dev.kobj), "master");
7543                 if (ret)
7544                         goto remove_symlinks;
7545
7546                 list_add_rcu(&adj->list, dev_list);
7547         } else {
7548                 list_add_tail_rcu(&adj->list, dev_list);
7549         }
7550
7551         return 0;
7552
7553 remove_symlinks:
7554         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7555                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7556 free_adj:
7557         netdev_put(adj_dev, &adj->dev_tracker);
7558         kfree(adj);
7559
7560         return ret;
7561 }
7562
7563 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7564                                          struct net_device *adj_dev,
7565                                          u16 ref_nr,
7566                                          struct list_head *dev_list)
7567 {
7568         struct netdev_adjacent *adj;
7569
7570         pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7571                  dev->name, adj_dev->name, ref_nr);
7572
7573         adj = __netdev_find_adj(adj_dev, dev_list);
7574
7575         if (!adj) {
7576                 pr_err("Adjacency does not exist for device %s from %s\n",
7577                        dev->name, adj_dev->name);
7578                 WARN_ON(1);
7579                 return;
7580         }
7581
7582         if (adj->ref_nr > ref_nr) {
7583                 pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7584                          dev->name, adj_dev->name, ref_nr,
7585                          adj->ref_nr - ref_nr);
7586                 adj->ref_nr -= ref_nr;
7587                 return;
7588         }
7589
7590         if (adj->master)
7591                 sysfs_remove_link(&(dev->dev.kobj), "master");
7592
7593         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7594                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7595
7596         list_del_rcu(&adj->list);
7597         pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7598                  adj_dev->name, dev->name, adj_dev->name);
7599         netdev_put(adj_dev, &adj->dev_tracker);
7600         kfree_rcu(adj, rcu);
7601 }
7602
7603 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7604                                             struct net_device *upper_dev,
7605                                             struct list_head *up_list,
7606                                             struct list_head *down_list,
7607                                             void *private, bool master)
7608 {
7609         int ret;
7610
7611         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7612                                            private, master);
7613         if (ret)
7614                 return ret;
7615
7616         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7617                                            private, false);
7618         if (ret) {
7619                 __netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7620                 return ret;
7621         }
7622
7623         return 0;
7624 }
7625
7626 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7627                                                struct net_device *upper_dev,
7628                                                u16 ref_nr,
7629                                                struct list_head *up_list,
7630                                                struct list_head *down_list)
7631 {
7632         __netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7633         __netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7634 }
7635
7636 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7637                                                 struct net_device *upper_dev,
7638                                                 void *private, bool master)
7639 {
7640         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7641                                                 &dev->adj_list.upper,
7642                                                 &upper_dev->adj_list.lower,
7643                                                 private, master);
7644 }
7645
7646 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7647                                                    struct net_device *upper_dev)
7648 {
7649         __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7650                                            &dev->adj_list.upper,
7651                                            &upper_dev->adj_list.lower);
7652 }
7653
7654 static int __netdev_upper_dev_link(struct net_device *dev,
7655                                    struct net_device *upper_dev, bool master,
7656                                    void *upper_priv, void *upper_info,
7657                                    struct netdev_nested_priv *priv,
7658                                    struct netlink_ext_ack *extack)
7659 {
7660         struct netdev_notifier_changeupper_info changeupper_info = {
7661                 .info = {
7662                         .dev = dev,
7663                         .extack = extack,
7664                 },
7665                 .upper_dev = upper_dev,
7666                 .master = master,
7667                 .linking = true,
7668                 .upper_info = upper_info,
7669         };
7670         struct net_device *master_dev;
7671         int ret = 0;
7672
7673         ASSERT_RTNL();
7674
7675         if (dev == upper_dev)
7676                 return -EBUSY;
7677
7678         /* To prevent loops, check if dev is not upper device to upper_dev. */
7679         if (__netdev_has_upper_dev(upper_dev, dev))
7680                 return -EBUSY;
7681
7682         if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7683                 return -EMLINK;
7684
7685         if (!master) {
7686                 if (__netdev_has_upper_dev(dev, upper_dev))
7687                         return -EEXIST;
7688         } else {
7689                 master_dev = __netdev_master_upper_dev_get(dev);
7690                 if (master_dev)
7691                         return master_dev == upper_dev ? -EEXIST : -EBUSY;
7692         }
7693
7694         ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7695                                             &changeupper_info.info);
7696         ret = notifier_to_errno(ret);
7697         if (ret)
7698                 return ret;
7699
7700         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7701                                                    master);
7702         if (ret)
7703                 return ret;
7704
7705         ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7706                                             &changeupper_info.info);
7707         ret = notifier_to_errno(ret);
7708         if (ret)
7709                 goto rollback;
7710
7711         __netdev_update_upper_level(dev, NULL);
7712         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7713
7714         __netdev_update_lower_level(upper_dev, priv);
7715         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7716                                     priv);
7717
7718         return 0;
7719
7720 rollback:
7721         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7722
7723         return ret;
7724 }
7725
7726 /**
7727  * netdev_upper_dev_link - Add a link to the upper device
7728  * @dev: device
7729  * @upper_dev: new upper device
7730  * @extack: netlink extended ack
7731  *
7732  * Adds a link to device which is upper to this one. The caller must hold
7733  * the RTNL lock. On a failure a negative errno code is returned.
7734  * On success the reference counts are adjusted and the function
7735  * returns zero.
7736  */
7737 int netdev_upper_dev_link(struct net_device *dev,
7738                           struct net_device *upper_dev,
7739                           struct netlink_ext_ack *extack)
7740 {
7741         struct netdev_nested_priv priv = {
7742                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7743                 .data = NULL,
7744         };
7745
7746         return __netdev_upper_dev_link(dev, upper_dev, false,
7747                                        NULL, NULL, &priv, extack);
7748 }
7749 EXPORT_SYMBOL(netdev_upper_dev_link);
7750
7751 /**
7752  * netdev_master_upper_dev_link - Add a master link to the upper device
7753  * @dev: device
7754  * @upper_dev: new upper device
7755  * @upper_priv: upper device private
7756  * @upper_info: upper info to be passed down via notifier
7757  * @extack: netlink extended ack
7758  *
7759  * Adds a link to device which is upper to this one. In this case, only
7760  * one master upper device can be linked, although other non-master devices
7761  * might be linked as well. The caller must hold the RTNL lock.
7762  * On a failure a negative errno code is returned. On success the reference
7763  * counts are adjusted and the function returns zero.
7764  */
7765 int netdev_master_upper_dev_link(struct net_device *dev,
7766                                  struct net_device *upper_dev,
7767                                  void *upper_priv, void *upper_info,
7768                                  struct netlink_ext_ack *extack)
7769 {
7770         struct netdev_nested_priv priv = {
7771                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7772                 .data = NULL,
7773         };
7774
7775         return __netdev_upper_dev_link(dev, upper_dev, true,
7776                                        upper_priv, upper_info, &priv, extack);
7777 }
7778 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7779
7780 static void __netdev_upper_dev_unlink(struct net_device *dev,
7781                                       struct net_device *upper_dev,
7782                                       struct netdev_nested_priv *priv)
7783 {
7784         struct netdev_notifier_changeupper_info changeupper_info = {
7785                 .info = {
7786                         .dev = dev,
7787                 },
7788                 .upper_dev = upper_dev,
7789                 .linking = false,
7790         };
7791
7792         ASSERT_RTNL();
7793
7794         changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7795
7796         call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7797                                       &changeupper_info.info);
7798
7799         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7800
7801         call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7802                                       &changeupper_info.info);
7803
7804         __netdev_update_upper_level(dev, NULL);
7805         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7806
7807         __netdev_update_lower_level(upper_dev, priv);
7808         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7809                                     priv);
7810 }
7811
7812 /**
7813  * netdev_upper_dev_unlink - Removes a link to upper device
7814  * @dev: device
7815  * @upper_dev: new upper device
7816  *
7817  * Removes a link to device which is upper to this one. The caller must hold
7818  * the RTNL lock.
7819  */
7820 void netdev_upper_dev_unlink(struct net_device *dev,
7821                              struct net_device *upper_dev)
7822 {
7823         struct netdev_nested_priv priv = {
7824                 .flags = NESTED_SYNC_TODO,
7825                 .data = NULL,
7826         };
7827
7828         __netdev_upper_dev_unlink(dev, upper_dev, &priv);
7829 }
7830 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7831
7832 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7833                                       struct net_device *lower_dev,
7834                                       bool val)
7835 {
7836         struct netdev_adjacent *adj;
7837
7838         adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7839         if (adj)
7840                 adj->ignore = val;
7841
7842         adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7843         if (adj)
7844                 adj->ignore = val;
7845 }
7846
7847 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7848                                         struct net_device *lower_dev)
7849 {
7850         __netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7851 }
7852
7853 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7854                                        struct net_device *lower_dev)
7855 {
7856         __netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7857 }
7858
7859 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7860                                    struct net_device *new_dev,
7861                                    struct net_device *dev,
7862                                    struct netlink_ext_ack *extack)
7863 {
7864         struct netdev_nested_priv priv = {
7865                 .flags = 0,
7866                 .data = NULL,
7867         };
7868         int err;
7869
7870         if (!new_dev)
7871                 return 0;
7872
7873         if (old_dev && new_dev != old_dev)
7874                 netdev_adjacent_dev_disable(dev, old_dev);
7875         err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7876                                       extack);
7877         if (err) {
7878                 if (old_dev && new_dev != old_dev)
7879                         netdev_adjacent_dev_enable(dev, old_dev);
7880                 return err;
7881         }
7882
7883         return 0;
7884 }
7885 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7886
7887 void netdev_adjacent_change_commit(struct net_device *old_dev,
7888                                    struct net_device *new_dev,
7889                                    struct net_device *dev)
7890 {
7891         struct netdev_nested_priv priv = {
7892                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7893                 .data = NULL,
7894         };
7895
7896         if (!new_dev || !old_dev)
7897                 return;
7898
7899         if (new_dev == old_dev)
7900                 return;
7901
7902         netdev_adjacent_dev_enable(dev, old_dev);
7903         __netdev_upper_dev_unlink(old_dev, dev, &priv);
7904 }
7905 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7906
7907 void netdev_adjacent_change_abort(struct net_device *old_dev,
7908                                   struct net_device *new_dev,
7909                                   struct net_device *dev)
7910 {
7911         struct netdev_nested_priv priv = {
7912                 .flags = 0,
7913                 .data = NULL,
7914         };
7915
7916         if (!new_dev)
7917                 return;
7918
7919         if (old_dev && new_dev != old_dev)
7920                 netdev_adjacent_dev_enable(dev, old_dev);
7921
7922         __netdev_upper_dev_unlink(new_dev, dev, &priv);
7923 }
7924 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7925
7926 /**
7927  * netdev_bonding_info_change - Dispatch event about slave change
7928  * @dev: device
7929  * @bonding_info: info to dispatch
7930  *
7931  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7932  * The caller must hold the RTNL lock.
7933  */
7934 void netdev_bonding_info_change(struct net_device *dev,
7935                                 struct netdev_bonding_info *bonding_info)
7936 {
7937         struct netdev_notifier_bonding_info info = {
7938                 .info.dev = dev,
7939         };
7940
7941         memcpy(&info.bonding_info, bonding_info,
7942                sizeof(struct netdev_bonding_info));
7943         call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7944                                       &info.info);
7945 }
7946 EXPORT_SYMBOL(netdev_bonding_info_change);
7947
7948 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7949                                            struct netlink_ext_ack *extack)
7950 {
7951         struct netdev_notifier_offload_xstats_info info = {
7952                 .info.dev = dev,
7953                 .info.extack = extack,
7954                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7955         };
7956         int err;
7957         int rc;
7958
7959         dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7960                                          GFP_KERNEL);
7961         if (!dev->offload_xstats_l3)
7962                 return -ENOMEM;
7963
7964         rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7965                                                   NETDEV_OFFLOAD_XSTATS_DISABLE,
7966                                                   &info.info);
7967         err = notifier_to_errno(rc);
7968         if (err)
7969                 goto free_stats;
7970
7971         return 0;
7972
7973 free_stats:
7974         kfree(dev->offload_xstats_l3);
7975         dev->offload_xstats_l3 = NULL;
7976         return err;
7977 }
7978
7979 int netdev_offload_xstats_enable(struct net_device *dev,
7980                                  enum netdev_offload_xstats_type type,
7981                                  struct netlink_ext_ack *extack)
7982 {
7983         ASSERT_RTNL();
7984
7985         if (netdev_offload_xstats_enabled(dev, type))
7986                 return -EALREADY;
7987
7988         switch (type) {
7989         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7990                 return netdev_offload_xstats_enable_l3(dev, extack);
7991         }
7992
7993         WARN_ON(1);
7994         return -EINVAL;
7995 }
7996 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7997
7998 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7999 {
8000         struct netdev_notifier_offload_xstats_info info = {
8001                 .info.dev = dev,
8002                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
8003         };
8004
8005         call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
8006                                       &info.info);
8007         kfree(dev->offload_xstats_l3);
8008         dev->offload_xstats_l3 = NULL;
8009 }
8010
8011 int netdev_offload_xstats_disable(struct net_device *dev,
8012                                   enum netdev_offload_xstats_type type)
8013 {
8014         ASSERT_RTNL();
8015
8016         if (!netdev_offload_xstats_enabled(dev, type))
8017                 return -EALREADY;
8018
8019         switch (type) {
8020         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8021                 netdev_offload_xstats_disable_l3(dev);
8022                 return 0;
8023         }
8024
8025         WARN_ON(1);
8026         return -EINVAL;
8027 }
8028 EXPORT_SYMBOL(netdev_offload_xstats_disable);
8029
8030 static void netdev_offload_xstats_disable_all(struct net_device *dev)
8031 {
8032         netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
8033 }
8034
8035 static struct rtnl_hw_stats64 *
8036 netdev_offload_xstats_get_ptr(const struct net_device *dev,
8037                               enum netdev_offload_xstats_type type)
8038 {
8039         switch (type) {
8040         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8041                 return dev->offload_xstats_l3;
8042         }
8043
8044         WARN_ON(1);
8045         return NULL;
8046 }
8047
8048 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8049                                    enum netdev_offload_xstats_type type)
8050 {
8051         ASSERT_RTNL();
8052
8053         return netdev_offload_xstats_get_ptr(dev, type);
8054 }
8055 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8056
8057 struct netdev_notifier_offload_xstats_ru {
8058         bool used;
8059 };
8060
8061 struct netdev_notifier_offload_xstats_rd {
8062         struct rtnl_hw_stats64 stats;
8063         bool used;
8064 };
8065
8066 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8067                                   const struct rtnl_hw_stats64 *src)
8068 {
8069         dest->rx_packets          += src->rx_packets;
8070         dest->tx_packets          += src->tx_packets;
8071         dest->rx_bytes            += src->rx_bytes;
8072         dest->tx_bytes            += src->tx_bytes;
8073         dest->rx_errors           += src->rx_errors;
8074         dest->tx_errors           += src->tx_errors;
8075         dest->rx_dropped          += src->rx_dropped;
8076         dest->tx_dropped          += src->tx_dropped;
8077         dest->multicast           += src->multicast;
8078 }
8079
8080 static int netdev_offload_xstats_get_used(struct net_device *dev,
8081                                           enum netdev_offload_xstats_type type,
8082                                           bool *p_used,
8083                                           struct netlink_ext_ack *extack)
8084 {
8085         struct netdev_notifier_offload_xstats_ru report_used = {};
8086         struct netdev_notifier_offload_xstats_info info = {
8087                 .info.dev = dev,
8088                 .info.extack = extack,
8089                 .type = type,
8090                 .report_used = &report_used,
8091         };
8092         int rc;
8093
8094         WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8095         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8096                                            &info.info);
8097         *p_used = report_used.used;
8098         return notifier_to_errno(rc);
8099 }
8100
8101 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8102                                            enum netdev_offload_xstats_type type,
8103                                            struct rtnl_hw_stats64 *p_stats,
8104                                            bool *p_used,
8105                                            struct netlink_ext_ack *extack)
8106 {
8107         struct netdev_notifier_offload_xstats_rd report_delta = {};
8108         struct netdev_notifier_offload_xstats_info info = {
8109                 .info.dev = dev,
8110                 .info.extack = extack,
8111                 .type = type,
8112                 .report_delta = &report_delta,
8113         };
8114         struct rtnl_hw_stats64 *stats;
8115         int rc;
8116
8117         stats = netdev_offload_xstats_get_ptr(dev, type);
8118         if (WARN_ON(!stats))
8119                 return -EINVAL;
8120
8121         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8122                                            &info.info);
8123
8124         /* Cache whatever we got, even if there was an error, otherwise the
8125          * successful stats retrievals would get lost.
8126          */
8127         netdev_hw_stats64_add(stats, &report_delta.stats);
8128
8129         if (p_stats)
8130                 *p_stats = *stats;
8131         *p_used = report_delta.used;
8132
8133         return notifier_to_errno(rc);
8134 }
8135
8136 int netdev_offload_xstats_get(struct net_device *dev,
8137                               enum netdev_offload_xstats_type type,
8138                               struct rtnl_hw_stats64 *p_stats, bool *p_used,
8139                               struct netlink_ext_ack *extack)
8140 {
8141         ASSERT_RTNL();
8142
8143         if (p_stats)
8144                 return netdev_offload_xstats_get_stats(dev, type, p_stats,
8145                                                        p_used, extack);
8146         else
8147                 return netdev_offload_xstats_get_used(dev, type, p_used,
8148                                                       extack);
8149 }
8150 EXPORT_SYMBOL(netdev_offload_xstats_get);
8151
8152 void
8153 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8154                                    const struct rtnl_hw_stats64 *stats)
8155 {
8156         report_delta->used = true;
8157         netdev_hw_stats64_add(&report_delta->stats, stats);
8158 }
8159 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8160
8161 void
8162 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8163 {
8164         report_used->used = true;
8165 }
8166 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8167
8168 void netdev_offload_xstats_push_delta(struct net_device *dev,
8169                                       enum netdev_offload_xstats_type type,
8170                                       const struct rtnl_hw_stats64 *p_stats)
8171 {
8172         struct rtnl_hw_stats64 *stats;
8173
8174         ASSERT_RTNL();
8175
8176         stats = netdev_offload_xstats_get_ptr(dev, type);
8177         if (WARN_ON(!stats))
8178                 return;
8179
8180         netdev_hw_stats64_add(stats, p_stats);
8181 }
8182 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8183
8184 /**
8185  * netdev_get_xmit_slave - Get the xmit slave of master device
8186  * @dev: device
8187  * @skb: The packet
8188  * @all_slaves: assume all the slaves are active
8189  *
8190  * The reference counters are not incremented so the caller must be
8191  * careful with locks. The caller must hold RCU lock.
8192  * %NULL is returned if no slave is found.
8193  */
8194
8195 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8196                                          struct sk_buff *skb,
8197                                          bool all_slaves)
8198 {
8199         const struct net_device_ops *ops = dev->netdev_ops;
8200
8201         if (!ops->ndo_get_xmit_slave)
8202                 return NULL;
8203         return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8204 }
8205 EXPORT_SYMBOL(netdev_get_xmit_slave);
8206
8207 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8208                                                   struct sock *sk)
8209 {
8210         const struct net_device_ops *ops = dev->netdev_ops;
8211
8212         if (!ops->ndo_sk_get_lower_dev)
8213                 return NULL;
8214         return ops->ndo_sk_get_lower_dev(dev, sk);
8215 }
8216
8217 /**
8218  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8219  * @dev: device
8220  * @sk: the socket
8221  *
8222  * %NULL is returned if no lower device is found.
8223  */
8224
8225 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8226                                             struct sock *sk)
8227 {
8228         struct net_device *lower;
8229
8230         lower = netdev_sk_get_lower_dev(dev, sk);
8231         while (lower) {
8232                 dev = lower;
8233                 lower = netdev_sk_get_lower_dev(dev, sk);
8234         }
8235
8236         return dev;
8237 }
8238 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8239
8240 static void netdev_adjacent_add_links(struct net_device *dev)
8241 {
8242         struct netdev_adjacent *iter;
8243
8244         struct net *net = dev_net(dev);
8245
8246         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8247                 if (!net_eq(net, dev_net(iter->dev)))
8248                         continue;
8249                 netdev_adjacent_sysfs_add(iter->dev, dev,
8250                                           &iter->dev->adj_list.lower);
8251                 netdev_adjacent_sysfs_add(dev, iter->dev,
8252                                           &dev->adj_list.upper);
8253         }
8254
8255         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8256                 if (!net_eq(net, dev_net(iter->dev)))
8257                         continue;
8258                 netdev_adjacent_sysfs_add(iter->dev, dev,
8259                                           &iter->dev->adj_list.upper);
8260                 netdev_adjacent_sysfs_add(dev, iter->dev,
8261                                           &dev->adj_list.lower);
8262         }
8263 }
8264
8265 static void netdev_adjacent_del_links(struct net_device *dev)
8266 {
8267         struct netdev_adjacent *iter;
8268
8269         struct net *net = dev_net(dev);
8270
8271         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8272                 if (!net_eq(net, dev_net(iter->dev)))
8273                         continue;
8274                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8275                                           &iter->dev->adj_list.lower);
8276                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8277                                           &dev->adj_list.upper);
8278         }
8279
8280         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8281                 if (!net_eq(net, dev_net(iter->dev)))
8282                         continue;
8283                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8284                                           &iter->dev->adj_list.upper);
8285                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8286                                           &dev->adj_list.lower);
8287         }
8288 }
8289
8290 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8291 {
8292         struct netdev_adjacent *iter;
8293
8294         struct net *net = dev_net(dev);
8295
8296         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8297                 if (!net_eq(net, dev_net(iter->dev)))
8298                         continue;
8299                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8300                                           &iter->dev->adj_list.lower);
8301                 netdev_adjacent_sysfs_add(iter->dev, dev,
8302                                           &iter->dev->adj_list.lower);
8303         }
8304
8305         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8306                 if (!net_eq(net, dev_net(iter->dev)))
8307                         continue;
8308                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8309                                           &iter->dev->adj_list.upper);
8310                 netdev_adjacent_sysfs_add(iter->dev, dev,
8311                                           &iter->dev->adj_list.upper);
8312         }
8313 }
8314
8315 void *netdev_lower_dev_get_private(struct net_device *dev,
8316                                    struct net_device *lower_dev)
8317 {
8318         struct netdev_adjacent *lower;
8319
8320         if (!lower_dev)
8321                 return NULL;
8322         lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8323         if (!lower)
8324                 return NULL;
8325
8326         return lower->private;
8327 }
8328 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8329
8330
8331 /**
8332  * netdev_lower_state_changed - Dispatch event about lower device state change
8333  * @lower_dev: device
8334  * @lower_state_info: state to dispatch
8335  *
8336  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8337  * The caller must hold the RTNL lock.
8338  */
8339 void netdev_lower_state_changed(struct net_device *lower_dev,
8340                                 void *lower_state_info)
8341 {
8342         struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8343                 .info.dev = lower_dev,
8344         };
8345
8346         ASSERT_RTNL();
8347         changelowerstate_info.lower_state_info = lower_state_info;
8348         call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8349                                       &changelowerstate_info.info);
8350 }
8351 EXPORT_SYMBOL(netdev_lower_state_changed);
8352
8353 static void dev_change_rx_flags(struct net_device *dev, int flags)
8354 {
8355         const struct net_device_ops *ops = dev->netdev_ops;
8356
8357         if (ops->ndo_change_rx_flags)
8358                 ops->ndo_change_rx_flags(dev, flags);
8359 }
8360
8361 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8362 {
8363         unsigned int old_flags = dev->flags;
8364         kuid_t uid;
8365         kgid_t gid;
8366
8367         ASSERT_RTNL();
8368
8369         dev->flags |= IFF_PROMISC;
8370         dev->promiscuity += inc;
8371         if (dev->promiscuity == 0) {
8372                 /*
8373                  * Avoid overflow.
8374                  * If inc causes overflow, untouch promisc and return error.
8375                  */
8376                 if (inc < 0)
8377                         dev->flags &= ~IFF_PROMISC;
8378                 else {
8379                         dev->promiscuity -= inc;
8380                         netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8381                         return -EOVERFLOW;
8382                 }
8383         }
8384         if (dev->flags != old_flags) {
8385                 netdev_info(dev, "%s promiscuous mode\n",
8386                             dev->flags & IFF_PROMISC ? "entered" : "left");
8387                 if (audit_enabled) {
8388                         current_uid_gid(&uid, &gid);
8389                         audit_log(audit_context(), GFP_ATOMIC,
8390                                   AUDIT_ANOM_PROMISCUOUS,
8391                                   "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8392                                   dev->name, (dev->flags & IFF_PROMISC),
8393                                   (old_flags & IFF_PROMISC),
8394                                   from_kuid(&init_user_ns, audit_get_loginuid(current)),
8395                                   from_kuid(&init_user_ns, uid),
8396                                   from_kgid(&init_user_ns, gid),
8397                                   audit_get_sessionid(current));
8398                 }
8399
8400                 dev_change_rx_flags(dev, IFF_PROMISC);
8401         }
8402         if (notify)
8403                 __dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8404         return 0;
8405 }
8406
8407 /**
8408  *      dev_set_promiscuity     - update promiscuity count on a device
8409  *      @dev: device
8410  *      @inc: modifier
8411  *
8412  *      Add or remove promiscuity from a device. While the count in the device
8413  *      remains above zero the interface remains promiscuous. Once it hits zero
8414  *      the device reverts back to normal filtering operation. A negative inc
8415  *      value is used to drop promiscuity on the device.
8416  *      Return 0 if successful or a negative errno code on error.
8417  */
8418 int dev_set_promiscuity(struct net_device *dev, int inc)
8419 {
8420         unsigned int old_flags = dev->flags;
8421         int err;
8422
8423         err = __dev_set_promiscuity(dev, inc, true);
8424         if (err < 0)
8425                 return err;
8426         if (dev->flags != old_flags)
8427                 dev_set_rx_mode(dev);
8428         return err;
8429 }
8430 EXPORT_SYMBOL(dev_set_promiscuity);
8431
8432 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8433 {
8434         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8435
8436         ASSERT_RTNL();
8437
8438         dev->flags |= IFF_ALLMULTI;
8439         dev->allmulti += inc;
8440         if (dev->allmulti == 0) {
8441                 /*
8442                  * Avoid overflow.
8443                  * If inc causes overflow, untouch allmulti and return error.
8444                  */
8445                 if (inc < 0)
8446                         dev->flags &= ~IFF_ALLMULTI;
8447                 else {
8448                         dev->allmulti -= inc;
8449                         netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8450                         return -EOVERFLOW;
8451                 }
8452         }
8453         if (dev->flags ^ old_flags) {
8454                 netdev_info(dev, "%s allmulticast mode\n",
8455                             dev->flags & IFF_ALLMULTI ? "entered" : "left");
8456                 dev_change_rx_flags(dev, IFF_ALLMULTI);
8457                 dev_set_rx_mode(dev);
8458                 if (notify)
8459                         __dev_notify_flags(dev, old_flags,
8460                                            dev->gflags ^ old_gflags, 0, NULL);
8461         }
8462         return 0;
8463 }
8464
8465 /**
8466  *      dev_set_allmulti        - update allmulti count on a device
8467  *      @dev: device
8468  *      @inc: modifier
8469  *
8470  *      Add or remove reception of all multicast frames to a device. While the
8471  *      count in the device remains above zero the interface remains listening
8472  *      to all interfaces. Once it hits zero the device reverts back to normal
8473  *      filtering operation. A negative @inc value is used to drop the counter
8474  *      when releasing a resource needing all multicasts.
8475  *      Return 0 if successful or a negative errno code on error.
8476  */
8477
8478 int dev_set_allmulti(struct net_device *dev, int inc)
8479 {
8480         return __dev_set_allmulti(dev, inc, true);
8481 }
8482 EXPORT_SYMBOL(dev_set_allmulti);
8483
8484 /*
8485  *      Upload unicast and multicast address lists to device and
8486  *      configure RX filtering. When the device doesn't support unicast
8487  *      filtering it is put in promiscuous mode while unicast addresses
8488  *      are present.
8489  */
8490 void __dev_set_rx_mode(struct net_device *dev)
8491 {
8492         const struct net_device_ops *ops = dev->netdev_ops;
8493
8494         /* dev_open will call this function so the list will stay sane. */
8495         if (!(dev->flags&IFF_UP))
8496                 return;
8497
8498         if (!netif_device_present(dev))
8499                 return;
8500
8501         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8502                 /* Unicast addresses changes may only happen under the rtnl,
8503                  * therefore calling __dev_set_promiscuity here is safe.
8504                  */
8505                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8506                         __dev_set_promiscuity(dev, 1, false);
8507                         dev->uc_promisc = true;
8508                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8509                         __dev_set_promiscuity(dev, -1, false);
8510                         dev->uc_promisc = false;
8511                 }
8512         }
8513
8514         if (ops->ndo_set_rx_mode)
8515                 ops->ndo_set_rx_mode(dev);
8516 }
8517
8518 void dev_set_rx_mode(struct net_device *dev)
8519 {
8520         netif_addr_lock_bh(dev);
8521         __dev_set_rx_mode(dev);
8522         netif_addr_unlock_bh(dev);
8523 }
8524
8525 /**
8526  *      dev_get_flags - get flags reported to userspace
8527  *      @dev: device
8528  *
8529  *      Get the combination of flag bits exported through APIs to userspace.
8530  */
8531 unsigned int dev_get_flags(const struct net_device *dev)
8532 {
8533         unsigned int flags;
8534
8535         flags = (dev->flags & ~(IFF_PROMISC |
8536                                 IFF_ALLMULTI |
8537                                 IFF_RUNNING |
8538                                 IFF_LOWER_UP |
8539                                 IFF_DORMANT)) |
8540                 (dev->gflags & (IFF_PROMISC |
8541                                 IFF_ALLMULTI));
8542
8543         if (netif_running(dev)) {
8544                 if (netif_oper_up(dev))
8545                         flags |= IFF_RUNNING;
8546                 if (netif_carrier_ok(dev))
8547                         flags |= IFF_LOWER_UP;
8548                 if (netif_dormant(dev))
8549                         flags |= IFF_DORMANT;
8550         }
8551
8552         return flags;
8553 }
8554 EXPORT_SYMBOL(dev_get_flags);
8555
8556 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8557                        struct netlink_ext_ack *extack)
8558 {
8559         unsigned int old_flags = dev->flags;
8560         int ret;
8561
8562         ASSERT_RTNL();
8563
8564         /*
8565          *      Set the flags on our device.
8566          */
8567
8568         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8569                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8570                                IFF_AUTOMEDIA)) |
8571                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8572                                     IFF_ALLMULTI));
8573
8574         /*
8575          *      Load in the correct multicast list now the flags have changed.
8576          */
8577
8578         if ((old_flags ^ flags) & IFF_MULTICAST)
8579                 dev_change_rx_flags(dev, IFF_MULTICAST);
8580
8581         dev_set_rx_mode(dev);
8582
8583         /*
8584          *      Have we downed the interface. We handle IFF_UP ourselves
8585          *      according to user attempts to set it, rather than blindly
8586          *      setting it.
8587          */
8588
8589         ret = 0;
8590         if ((old_flags ^ flags) & IFF_UP) {
8591                 if (old_flags & IFF_UP)
8592                         __dev_close(dev);
8593                 else
8594                         ret = __dev_open(dev, extack);
8595         }
8596
8597         if ((flags ^ dev->gflags) & IFF_PROMISC) {
8598                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
8599                 unsigned int old_flags = dev->flags;
8600
8601                 dev->gflags ^= IFF_PROMISC;
8602
8603                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
8604                         if (dev->flags != old_flags)
8605                                 dev_set_rx_mode(dev);
8606         }
8607
8608         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8609          * is important. Some (broken) drivers set IFF_PROMISC, when
8610          * IFF_ALLMULTI is requested not asking us and not reporting.
8611          */
8612         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8613                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8614
8615                 dev->gflags ^= IFF_ALLMULTI;
8616                 __dev_set_allmulti(dev, inc, false);
8617         }
8618
8619         return ret;
8620 }
8621
8622 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8623                         unsigned int gchanges, u32 portid,
8624                         const struct nlmsghdr *nlh)
8625 {
8626         unsigned int changes = dev->flags ^ old_flags;
8627
8628         if (gchanges)
8629                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8630
8631         if (changes & IFF_UP) {
8632                 if (dev->flags & IFF_UP)
8633                         call_netdevice_notifiers(NETDEV_UP, dev);
8634                 else
8635                         call_netdevice_notifiers(NETDEV_DOWN, dev);
8636         }
8637
8638         if (dev->flags & IFF_UP &&
8639             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8640                 struct netdev_notifier_change_info change_info = {
8641                         .info = {
8642                                 .dev = dev,
8643                         },
8644                         .flags_changed = changes,
8645                 };
8646
8647                 call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8648         }
8649 }
8650
8651 /**
8652  *      dev_change_flags - change device settings
8653  *      @dev: device
8654  *      @flags: device state flags
8655  *      @extack: netlink extended ack
8656  *
8657  *      Change settings on device based state flags. The flags are
8658  *      in the userspace exported format.
8659  */
8660 int dev_change_flags(struct net_device *dev, unsigned int flags,
8661                      struct netlink_ext_ack *extack)
8662 {
8663         int ret;
8664         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8665
8666         ret = __dev_change_flags(dev, flags, extack);
8667         if (ret < 0)
8668                 return ret;
8669
8670         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8671         __dev_notify_flags(dev, old_flags, changes, 0, NULL);
8672         return ret;
8673 }
8674 EXPORT_SYMBOL(dev_change_flags);
8675
8676 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8677 {
8678         const struct net_device_ops *ops = dev->netdev_ops;
8679
8680         if (ops->ndo_change_mtu)
8681                 return ops->ndo_change_mtu(dev, new_mtu);
8682
8683         /* Pairs with all the lockless reads of dev->mtu in the stack */
8684         WRITE_ONCE(dev->mtu, new_mtu);
8685         return 0;
8686 }
8687 EXPORT_SYMBOL(__dev_set_mtu);
8688
8689 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8690                      struct netlink_ext_ack *extack)
8691 {
8692         /* MTU must be positive, and in range */
8693         if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8694                 NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8695                 return -EINVAL;
8696         }
8697
8698         if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8699                 NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8700                 return -EINVAL;
8701         }
8702         return 0;
8703 }
8704
8705 /**
8706  *      dev_set_mtu_ext - Change maximum transfer unit
8707  *      @dev: device
8708  *      @new_mtu: new transfer unit
8709  *      @extack: netlink extended ack
8710  *
8711  *      Change the maximum transfer size of the network device.
8712  */
8713 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8714                     struct netlink_ext_ack *extack)
8715 {
8716         int err, orig_mtu;
8717
8718         if (new_mtu == dev->mtu)
8719                 return 0;
8720
8721         err = dev_validate_mtu(dev, new_mtu, extack);
8722         if (err)
8723                 return err;
8724
8725         if (!netif_device_present(dev))
8726                 return -ENODEV;
8727
8728         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8729         err = notifier_to_errno(err);
8730         if (err)
8731                 return err;
8732
8733         orig_mtu = dev->mtu;
8734         err = __dev_set_mtu(dev, new_mtu);
8735
8736         if (!err) {
8737                 err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8738                                                    orig_mtu);
8739                 err = notifier_to_errno(err);
8740                 if (err) {
8741                         /* setting mtu back and notifying everyone again,
8742                          * so that they have a chance to revert changes.
8743                          */
8744                         __dev_set_mtu(dev, orig_mtu);
8745                         call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8746                                                      new_mtu);
8747                 }
8748         }
8749         return err;
8750 }
8751
8752 int dev_set_mtu(struct net_device *dev, int new_mtu)
8753 {
8754         struct netlink_ext_ack extack;
8755         int err;
8756
8757         memset(&extack, 0, sizeof(extack));
8758         err = dev_set_mtu_ext(dev, new_mtu, &extack);
8759         if (err && extack._msg)
8760                 net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8761         return err;
8762 }
8763 EXPORT_SYMBOL(dev_set_mtu);
8764
8765 /**
8766  *      dev_change_tx_queue_len - Change TX queue length of a netdevice
8767  *      @dev: device
8768  *      @new_len: new tx queue length
8769  */
8770 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8771 {
8772         unsigned int orig_len = dev->tx_queue_len;
8773         int res;
8774
8775         if (new_len != (unsigned int)new_len)
8776                 return -ERANGE;
8777
8778         if (new_len != orig_len) {
8779                 dev->tx_queue_len = new_len;
8780                 res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8781                 res = notifier_to_errno(res);
8782                 if (res)
8783                         goto err_rollback;
8784                 res = dev_qdisc_change_tx_queue_len(dev);
8785                 if (res)
8786                         goto err_rollback;
8787         }
8788
8789         return 0;
8790
8791 err_rollback:
8792         netdev_err(dev, "refused to change device tx_queue_len\n");
8793         dev->tx_queue_len = orig_len;
8794         return res;
8795 }
8796
8797 /**
8798  *      dev_set_group - Change group this device belongs to
8799  *      @dev: device
8800  *      @new_group: group this device should belong to
8801  */
8802 void dev_set_group(struct net_device *dev, int new_group)
8803 {
8804         dev->group = new_group;
8805 }
8806
8807 /**
8808  *      dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8809  *      @dev: device
8810  *      @addr: new address
8811  *      @extack: netlink extended ack
8812  */
8813 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8814                               struct netlink_ext_ack *extack)
8815 {
8816         struct netdev_notifier_pre_changeaddr_info info = {
8817                 .info.dev = dev,
8818                 .info.extack = extack,
8819                 .dev_addr = addr,
8820         };
8821         int rc;
8822
8823         rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8824         return notifier_to_errno(rc);
8825 }
8826 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8827
8828 /**
8829  *      dev_set_mac_address - Change Media Access Control Address
8830  *      @dev: device
8831  *      @sa: new address
8832  *      @extack: netlink extended ack
8833  *
8834  *      Change the hardware (MAC) address of the device
8835  */
8836 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8837                         struct netlink_ext_ack *extack)
8838 {
8839         const struct net_device_ops *ops = dev->netdev_ops;
8840         int err;
8841
8842         if (!ops->ndo_set_mac_address)
8843                 return -EOPNOTSUPP;
8844         if (sa->sa_family != dev->type)
8845                 return -EINVAL;
8846         if (!netif_device_present(dev))
8847                 return -ENODEV;
8848         err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8849         if (err)
8850                 return err;
8851         if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
8852                 err = ops->ndo_set_mac_address(dev, sa);
8853                 if (err)
8854                         return err;
8855         }
8856         dev->addr_assign_type = NET_ADDR_SET;
8857         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8858         add_device_randomness(dev->dev_addr, dev->addr_len);
8859         return 0;
8860 }
8861 EXPORT_SYMBOL(dev_set_mac_address);
8862
8863 static DECLARE_RWSEM(dev_addr_sem);
8864
8865 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8866                              struct netlink_ext_ack *extack)
8867 {
8868         int ret;
8869
8870         down_write(&dev_addr_sem);
8871         ret = dev_set_mac_address(dev, sa, extack);
8872         up_write(&dev_addr_sem);
8873         return ret;
8874 }
8875 EXPORT_SYMBOL(dev_set_mac_address_user);
8876
8877 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8878 {
8879         size_t size = sizeof(sa->sa_data_min);
8880         struct net_device *dev;
8881         int ret = 0;
8882
8883         down_read(&dev_addr_sem);
8884         rcu_read_lock();
8885
8886         dev = dev_get_by_name_rcu(net, dev_name);
8887         if (!dev) {
8888                 ret = -ENODEV;
8889                 goto unlock;
8890         }
8891         if (!dev->addr_len)
8892                 memset(sa->sa_data, 0, size);
8893         else
8894                 memcpy(sa->sa_data, dev->dev_addr,
8895                        min_t(size_t, size, dev->addr_len));
8896         sa->sa_family = dev->type;
8897
8898 unlock:
8899         rcu_read_unlock();
8900         up_read(&dev_addr_sem);
8901         return ret;
8902 }
8903 EXPORT_SYMBOL(dev_get_mac_address);
8904
8905 /**
8906  *      dev_change_carrier - Change device carrier
8907  *      @dev: device
8908  *      @new_carrier: new value
8909  *
8910  *      Change device carrier
8911  */
8912 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8913 {
8914         const struct net_device_ops *ops = dev->netdev_ops;
8915
8916         if (!ops->ndo_change_carrier)
8917                 return -EOPNOTSUPP;
8918         if (!netif_device_present(dev))
8919                 return -ENODEV;
8920         return ops->ndo_change_carrier(dev, new_carrier);
8921 }
8922
8923 /**
8924  *      dev_get_phys_port_id - Get device physical port ID
8925  *      @dev: device
8926  *      @ppid: port ID
8927  *
8928  *      Get device physical port ID
8929  */
8930 int dev_get_phys_port_id(struct net_device *dev,
8931                          struct netdev_phys_item_id *ppid)
8932 {
8933         const struct net_device_ops *ops = dev->netdev_ops;
8934
8935         if (!ops->ndo_get_phys_port_id)
8936                 return -EOPNOTSUPP;
8937         return ops->ndo_get_phys_port_id(dev, ppid);
8938 }
8939
8940 /**
8941  *      dev_get_phys_port_name - Get device physical port name
8942  *      @dev: device
8943  *      @name: port name
8944  *      @len: limit of bytes to copy to name
8945  *
8946  *      Get device physical port name
8947  */
8948 int dev_get_phys_port_name(struct net_device *dev,
8949                            char *name, size_t len)
8950 {
8951         const struct net_device_ops *ops = dev->netdev_ops;
8952         int err;
8953
8954         if (ops->ndo_get_phys_port_name) {
8955                 err = ops->ndo_get_phys_port_name(dev, name, len);
8956                 if (err != -EOPNOTSUPP)
8957                         return err;
8958         }
8959         return devlink_compat_phys_port_name_get(dev, name, len);
8960 }
8961
8962 /**
8963  *      dev_get_port_parent_id - Get the device's port parent identifier
8964  *      @dev: network device
8965  *      @ppid: pointer to a storage for the port's parent identifier
8966  *      @recurse: allow/disallow recursion to lower devices
8967  *
8968  *      Get the devices's port parent identifier
8969  */
8970 int dev_get_port_parent_id(struct net_device *dev,
8971                            struct netdev_phys_item_id *ppid,
8972                            bool recurse)
8973 {
8974         const struct net_device_ops *ops = dev->netdev_ops;
8975         struct netdev_phys_item_id first = { };
8976         struct net_device *lower_dev;
8977         struct list_head *iter;
8978         int err;
8979
8980         if (ops->ndo_get_port_parent_id) {
8981                 err = ops->ndo_get_port_parent_id(dev, ppid);
8982                 if (err != -EOPNOTSUPP)
8983                         return err;
8984         }
8985
8986         err = devlink_compat_switch_id_get(dev, ppid);
8987         if (!recurse || err != -EOPNOTSUPP)
8988                 return err;
8989
8990         netdev_for_each_lower_dev(dev, lower_dev, iter) {
8991                 err = dev_get_port_parent_id(lower_dev, ppid, true);
8992                 if (err)
8993                         break;
8994                 if (!first.id_len)
8995                         first = *ppid;
8996                 else if (memcmp(&first, ppid, sizeof(*ppid)))
8997                         return -EOPNOTSUPP;
8998         }
8999
9000         return err;
9001 }
9002 EXPORT_SYMBOL(dev_get_port_parent_id);
9003
9004 /**
9005  *      netdev_port_same_parent_id - Indicate if two network devices have
9006  *      the same port parent identifier
9007  *      @a: first network device
9008  *      @b: second network device
9009  */
9010 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
9011 {
9012         struct netdev_phys_item_id a_id = { };
9013         struct netdev_phys_item_id b_id = { };
9014
9015         if (dev_get_port_parent_id(a, &a_id, true) ||
9016             dev_get_port_parent_id(b, &b_id, true))
9017                 return false;
9018
9019         return netdev_phys_item_id_same(&a_id, &b_id);
9020 }
9021 EXPORT_SYMBOL(netdev_port_same_parent_id);
9022
9023 /**
9024  *      dev_change_proto_down - set carrier according to proto_down.
9025  *
9026  *      @dev: device
9027  *      @proto_down: new value
9028  */
9029 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9030 {
9031         if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
9032                 return -EOPNOTSUPP;
9033         if (!netif_device_present(dev))
9034                 return -ENODEV;
9035         if (proto_down)
9036                 netif_carrier_off(dev);
9037         else
9038                 netif_carrier_on(dev);
9039         dev->proto_down = proto_down;
9040         return 0;
9041 }
9042
9043 /**
9044  *      dev_change_proto_down_reason - proto down reason
9045  *
9046  *      @dev: device
9047  *      @mask: proto down mask
9048  *      @value: proto down value
9049  */
9050 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9051                                   u32 value)
9052 {
9053         int b;
9054
9055         if (!mask) {
9056                 dev->proto_down_reason = value;
9057         } else {
9058                 for_each_set_bit(b, &mask, 32) {
9059                         if (value & (1 << b))
9060                                 dev->proto_down_reason |= BIT(b);
9061                         else
9062                                 dev->proto_down_reason &= ~BIT(b);
9063                 }
9064         }
9065 }
9066
9067 struct bpf_xdp_link {
9068         struct bpf_link link;
9069         struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9070         int flags;
9071 };
9072
9073 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9074 {
9075         if (flags & XDP_FLAGS_HW_MODE)
9076                 return XDP_MODE_HW;
9077         if (flags & XDP_FLAGS_DRV_MODE)
9078                 return XDP_MODE_DRV;
9079         if (flags & XDP_FLAGS_SKB_MODE)
9080                 return XDP_MODE_SKB;
9081         return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9082 }
9083
9084 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9085 {
9086         switch (mode) {
9087         case XDP_MODE_SKB:
9088                 return generic_xdp_install;
9089         case XDP_MODE_DRV:
9090         case XDP_MODE_HW:
9091                 return dev->netdev_ops->ndo_bpf;
9092         default:
9093                 return NULL;
9094         }
9095 }
9096
9097 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9098                                          enum bpf_xdp_mode mode)
9099 {
9100         return dev->xdp_state[mode].link;
9101 }
9102
9103 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9104                                      enum bpf_xdp_mode mode)
9105 {
9106         struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9107
9108         if (link)
9109                 return link->link.prog;
9110         return dev->xdp_state[mode].prog;
9111 }
9112
9113 u8 dev_xdp_prog_count(struct net_device *dev)
9114 {
9115         u8 count = 0;
9116         int i;
9117
9118         for (i = 0; i < __MAX_XDP_MODE; i++)
9119                 if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9120                         count++;
9121         return count;
9122 }
9123 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9124
9125 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9126 {
9127         struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9128
9129         return prog ? prog->aux->id : 0;
9130 }
9131
9132 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9133                              struct bpf_xdp_link *link)
9134 {
9135         dev->xdp_state[mode].link = link;
9136         dev->xdp_state[mode].prog = NULL;
9137 }
9138
9139 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9140                              struct bpf_prog *prog)
9141 {
9142         dev->xdp_state[mode].link = NULL;
9143         dev->xdp_state[mode].prog = prog;
9144 }
9145
9146 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9147                            bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9148                            u32 flags, struct bpf_prog *prog)
9149 {
9150         struct netdev_bpf xdp;
9151         int err;
9152
9153         memset(&xdp, 0, sizeof(xdp));
9154         xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9155         xdp.extack = extack;
9156         xdp.flags = flags;
9157         xdp.prog = prog;
9158
9159         /* Drivers assume refcnt is already incremented (i.e, prog pointer is
9160          * "moved" into driver), so they don't increment it on their own, but
9161          * they do decrement refcnt when program is detached or replaced.
9162          * Given net_device also owns link/prog, we need to bump refcnt here
9163          * to prevent drivers from underflowing it.
9164          */
9165         if (prog)
9166                 bpf_prog_inc(prog);
9167         err = bpf_op(dev, &xdp);
9168         if (err) {
9169                 if (prog)
9170                         bpf_prog_put(prog);
9171                 return err;
9172         }
9173
9174         if (mode != XDP_MODE_HW)
9175                 bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9176
9177         return 0;
9178 }
9179
9180 static void dev_xdp_uninstall(struct net_device *dev)
9181 {
9182         struct bpf_xdp_link *link;
9183         struct bpf_prog *prog;
9184         enum bpf_xdp_mode mode;
9185         bpf_op_t bpf_op;
9186
9187         ASSERT_RTNL();
9188
9189         for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9190                 prog = dev_xdp_prog(dev, mode);
9191                 if (!prog)
9192                         continue;
9193
9194                 bpf_op = dev_xdp_bpf_op(dev, mode);
9195                 if (!bpf_op)
9196                         continue;
9197
9198                 WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9199
9200                 /* auto-detach link from net device */
9201                 link = dev_xdp_link(dev, mode);
9202                 if (link)
9203                         link->dev = NULL;
9204                 else
9205                         bpf_prog_put(prog);
9206
9207                 dev_xdp_set_link(dev, mode, NULL);
9208         }
9209 }
9210
9211 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9212                           struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9213                           struct bpf_prog *old_prog, u32 flags)
9214 {
9215         unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9216         struct bpf_prog *cur_prog;
9217         struct net_device *upper;
9218         struct list_head *iter;
9219         enum bpf_xdp_mode mode;
9220         bpf_op_t bpf_op;
9221         int err;
9222
9223         ASSERT_RTNL();
9224
9225         /* either link or prog attachment, never both */
9226         if (link && (new_prog || old_prog))
9227                 return -EINVAL;
9228         /* link supports only XDP mode flags */
9229         if (link && (flags & ~XDP_FLAGS_MODES)) {
9230                 NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9231                 return -EINVAL;
9232         }
9233         /* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9234         if (num_modes > 1) {
9235                 NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9236                 return -EINVAL;
9237         }
9238         /* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9239         if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9240                 NL_SET_ERR_MSG(extack,
9241                                "More than one program loaded, unset mode is ambiguous");
9242                 return -EINVAL;
9243         }
9244         /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9245         if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9246                 NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9247                 return -EINVAL;
9248         }
9249
9250         mode = dev_xdp_mode(dev, flags);
9251         /* can't replace attached link */
9252         if (dev_xdp_link(dev, mode)) {
9253                 NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9254                 return -EBUSY;
9255         }
9256
9257         /* don't allow if an upper device already has a program */
9258         netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9259                 if (dev_xdp_prog_count(upper) > 0) {
9260                         NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9261                         return -EEXIST;
9262                 }
9263         }
9264
9265         cur_prog = dev_xdp_prog(dev, mode);
9266         /* can't replace attached prog with link */
9267         if (link && cur_prog) {
9268                 NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9269                 return -EBUSY;
9270         }
9271         if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9272                 NL_SET_ERR_MSG(extack, "Active program does not match expected");
9273                 return -EEXIST;
9274         }
9275
9276         /* put effective new program into new_prog */
9277         if (link)
9278                 new_prog = link->link.prog;
9279
9280         if (new_prog) {
9281                 bool offload = mode == XDP_MODE_HW;
9282                 enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9283                                                ? XDP_MODE_DRV : XDP_MODE_SKB;
9284
9285                 if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9286                         NL_SET_ERR_MSG(extack, "XDP program already attached");
9287                         return -EBUSY;
9288                 }
9289                 if (!offload && dev_xdp_prog(dev, other_mode)) {
9290                         NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9291                         return -EEXIST;
9292                 }
9293                 if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9294                         NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9295                         return -EINVAL;
9296                 }
9297                 if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9298                         NL_SET_ERR_MSG(extack, "Program bound to different device");
9299                         return -EINVAL;
9300                 }
9301                 if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9302                         NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9303                         return -EINVAL;
9304                 }
9305                 if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9306                         NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9307                         return -EINVAL;
9308                 }
9309         }
9310
9311         /* don't call drivers if the effective program didn't change */
9312         if (new_prog != cur_prog) {
9313                 bpf_op = dev_xdp_bpf_op(dev, mode);
9314                 if (!bpf_op) {
9315                         NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9316                         return -EOPNOTSUPP;
9317                 }
9318
9319                 err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9320                 if (err)
9321                         return err;
9322         }
9323
9324         if (link)
9325                 dev_xdp_set_link(dev, mode, link);
9326         else
9327                 dev_xdp_set_prog(dev, mode, new_prog);
9328         if (cur_prog)
9329                 bpf_prog_put(cur_prog);
9330
9331         return 0;
9332 }
9333
9334 static int dev_xdp_attach_link(struct net_device *dev,
9335                                struct netlink_ext_ack *extack,
9336                                struct bpf_xdp_link *link)
9337 {
9338         return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9339 }
9340
9341 static int dev_xdp_detach_link(struct net_device *dev,
9342                                struct netlink_ext_ack *extack,
9343                                struct bpf_xdp_link *link)
9344 {
9345         enum bpf_xdp_mode mode;
9346         bpf_op_t bpf_op;
9347
9348         ASSERT_RTNL();
9349
9350         mode = dev_xdp_mode(dev, link->flags);
9351         if (dev_xdp_link(dev, mode) != link)
9352                 return -EINVAL;
9353
9354         bpf_op = dev_xdp_bpf_op(dev, mode);
9355         WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9356         dev_xdp_set_link(dev, mode, NULL);
9357         return 0;
9358 }
9359
9360 static void bpf_xdp_link_release(struct bpf_link *link)
9361 {
9362         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9363
9364         rtnl_lock();
9365
9366         /* if racing with net_device's tear down, xdp_link->dev might be
9367          * already NULL, in which case link was already auto-detached
9368          */
9369         if (xdp_link->dev) {
9370                 WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9371                 xdp_link->dev = NULL;
9372         }
9373
9374         rtnl_unlock();
9375 }
9376
9377 static int bpf_xdp_link_detach(struct bpf_link *link)
9378 {
9379         bpf_xdp_link_release(link);
9380         return 0;
9381 }
9382
9383 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9384 {
9385         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9386
9387         kfree(xdp_link);
9388 }
9389
9390 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9391                                      struct seq_file *seq)
9392 {
9393         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9394         u32 ifindex = 0;
9395
9396         rtnl_lock();
9397         if (xdp_link->dev)
9398                 ifindex = xdp_link->dev->ifindex;
9399         rtnl_unlock();
9400
9401         seq_printf(seq, "ifindex:\t%u\n", ifindex);
9402 }
9403
9404 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9405                                        struct bpf_link_info *info)
9406 {
9407         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9408         u32 ifindex = 0;
9409
9410         rtnl_lock();
9411         if (xdp_link->dev)
9412                 ifindex = xdp_link->dev->ifindex;
9413         rtnl_unlock();
9414
9415         info->xdp.ifindex = ifindex;
9416         return 0;
9417 }
9418
9419 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9420                                struct bpf_prog *old_prog)
9421 {
9422         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9423         enum bpf_xdp_mode mode;
9424         bpf_op_t bpf_op;
9425         int err = 0;
9426
9427         rtnl_lock();
9428
9429         /* link might have been auto-released already, so fail */
9430         if (!xdp_link->dev) {
9431                 err = -ENOLINK;
9432                 goto out_unlock;
9433         }
9434
9435         if (old_prog && link->prog != old_prog) {
9436                 err = -EPERM;
9437                 goto out_unlock;
9438         }
9439         old_prog = link->prog;
9440         if (old_prog->type != new_prog->type ||
9441             old_prog->expected_attach_type != new_prog->expected_attach_type) {
9442                 err = -EINVAL;
9443                 goto out_unlock;
9444         }
9445
9446         if (old_prog == new_prog) {
9447                 /* no-op, don't disturb drivers */
9448                 bpf_prog_put(new_prog);
9449                 goto out_unlock;
9450         }
9451
9452         mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9453         bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9454         err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9455                               xdp_link->flags, new_prog);
9456         if (err)
9457                 goto out_unlock;
9458
9459         old_prog = xchg(&link->prog, new_prog);
9460         bpf_prog_put(old_prog);
9461
9462 out_unlock:
9463         rtnl_unlock();
9464         return err;
9465 }
9466
9467 static const struct bpf_link_ops bpf_xdp_link_lops = {
9468         .release = bpf_xdp_link_release,
9469         .dealloc = bpf_xdp_link_dealloc,
9470         .detach = bpf_xdp_link_detach,
9471         .show_fdinfo = bpf_xdp_link_show_fdinfo,
9472         .fill_link_info = bpf_xdp_link_fill_link_info,
9473         .update_prog = bpf_xdp_link_update,
9474 };
9475
9476 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9477 {
9478         struct net *net = current->nsproxy->net_ns;
9479         struct bpf_link_primer link_primer;
9480         struct netlink_ext_ack extack = {};
9481         struct bpf_xdp_link *link;
9482         struct net_device *dev;
9483         int err, fd;
9484
9485         rtnl_lock();
9486         dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9487         if (!dev) {
9488                 rtnl_unlock();
9489                 return -EINVAL;
9490         }
9491
9492         link = kzalloc(sizeof(*link), GFP_USER);
9493         if (!link) {
9494                 err = -ENOMEM;
9495                 goto unlock;
9496         }
9497
9498         bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9499         link->dev = dev;
9500         link->flags = attr->link_create.flags;
9501
9502         err = bpf_link_prime(&link->link, &link_primer);
9503         if (err) {
9504                 kfree(link);
9505                 goto unlock;
9506         }
9507
9508         err = dev_xdp_attach_link(dev, &extack, link);
9509         rtnl_unlock();
9510
9511         if (err) {
9512                 link->dev = NULL;
9513                 bpf_link_cleanup(&link_primer);
9514                 trace_bpf_xdp_link_attach_failed(extack._msg);
9515                 goto out_put_dev;
9516         }
9517
9518         fd = bpf_link_settle(&link_primer);
9519         /* link itself doesn't hold dev's refcnt to not complicate shutdown */
9520         dev_put(dev);
9521         return fd;
9522
9523 unlock:
9524         rtnl_unlock();
9525
9526 out_put_dev:
9527         dev_put(dev);
9528         return err;
9529 }
9530
9531 /**
9532  *      dev_change_xdp_fd - set or clear a bpf program for a device rx path
9533  *      @dev: device
9534  *      @extack: netlink extended ack
9535  *      @fd: new program fd or negative value to clear
9536  *      @expected_fd: old program fd that userspace expects to replace or clear
9537  *      @flags: xdp-related flags
9538  *
9539  *      Set or clear a bpf program for a device
9540  */
9541 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9542                       int fd, int expected_fd, u32 flags)
9543 {
9544         enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9545         struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9546         int err;
9547
9548         ASSERT_RTNL();
9549
9550         if (fd >= 0) {
9551                 new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9552                                                  mode != XDP_MODE_SKB);
9553                 if (IS_ERR(new_prog))
9554                         return PTR_ERR(new_prog);
9555         }
9556
9557         if (expected_fd >= 0) {
9558                 old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9559                                                  mode != XDP_MODE_SKB);
9560                 if (IS_ERR(old_prog)) {
9561                         err = PTR_ERR(old_prog);
9562                         old_prog = NULL;
9563                         goto err_out;
9564                 }
9565         }
9566
9567         err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9568
9569 err_out:
9570         if (err && new_prog)
9571                 bpf_prog_put(new_prog);
9572         if (old_prog)
9573                 bpf_prog_put(old_prog);
9574         return err;
9575 }
9576
9577 /**
9578  * dev_index_reserve() - allocate an ifindex in a namespace
9579  * @net: the applicable net namespace
9580  * @ifindex: requested ifindex, pass %0 to get one allocated
9581  *
9582  * Allocate a ifindex for a new device. Caller must either use the ifindex
9583  * to store the device (via list_netdevice()) or call dev_index_release()
9584  * to give the index up.
9585  *
9586  * Return: a suitable unique value for a new device interface number or -errno.
9587  */
9588 static int dev_index_reserve(struct net *net, u32 ifindex)
9589 {
9590         int err;
9591
9592         if (ifindex > INT_MAX) {
9593                 DEBUG_NET_WARN_ON_ONCE(1);
9594                 return -EINVAL;
9595         }
9596
9597         if (!ifindex)
9598                 err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
9599                                       xa_limit_31b, &net->ifindex, GFP_KERNEL);
9600         else
9601                 err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
9602         if (err < 0)
9603                 return err;
9604
9605         return ifindex;
9606 }
9607
9608 static void dev_index_release(struct net *net, int ifindex)
9609 {
9610         /* Expect only unused indexes, unlist_netdevice() removes the used */
9611         WARN_ON(xa_erase(&net->dev_by_index, ifindex));
9612 }
9613
9614 /* Delayed registration/unregisteration */
9615 LIST_HEAD(net_todo_list);
9616 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9617
9618 static void net_set_todo(struct net_device *dev)
9619 {
9620         list_add_tail(&dev->todo_list, &net_todo_list);
9621         atomic_inc(&dev_net(dev)->dev_unreg_count);
9622 }
9623
9624 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9625         struct net_device *upper, netdev_features_t features)
9626 {
9627         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9628         netdev_features_t feature;
9629         int feature_bit;
9630
9631         for_each_netdev_feature(upper_disables, feature_bit) {
9632                 feature = __NETIF_F_BIT(feature_bit);
9633                 if (!(upper->wanted_features & feature)
9634                     && (features & feature)) {
9635                         netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9636                                    &feature, upper->name);
9637                         features &= ~feature;
9638                 }
9639         }
9640
9641         return features;
9642 }
9643
9644 static void netdev_sync_lower_features(struct net_device *upper,
9645         struct net_device *lower, netdev_features_t features)
9646 {
9647         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9648         netdev_features_t feature;
9649         int feature_bit;
9650
9651         for_each_netdev_feature(upper_disables, feature_bit) {
9652                 feature = __NETIF_F_BIT(feature_bit);
9653                 if (!(features & feature) && (lower->features & feature)) {
9654                         netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9655                                    &feature, lower->name);
9656                         lower->wanted_features &= ~feature;
9657                         __netdev_update_features(lower);
9658
9659                         if (unlikely(lower->features & feature))
9660                                 netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9661                                             &feature, lower->name);
9662                         else
9663                                 netdev_features_change(lower);
9664                 }
9665         }
9666 }
9667
9668 static netdev_features_t netdev_fix_features(struct net_device *dev,
9669         netdev_features_t features)
9670 {
9671         /* Fix illegal checksum combinations */
9672         if ((features & NETIF_F_HW_CSUM) &&
9673             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9674                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9675                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9676         }
9677
9678         /* TSO requires that SG is present as well. */
9679         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9680                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9681                 features &= ~NETIF_F_ALL_TSO;
9682         }
9683
9684         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9685                                         !(features & NETIF_F_IP_CSUM)) {
9686                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9687                 features &= ~NETIF_F_TSO;
9688                 features &= ~NETIF_F_TSO_ECN;
9689         }
9690
9691         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9692                                          !(features & NETIF_F_IPV6_CSUM)) {
9693                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9694                 features &= ~NETIF_F_TSO6;
9695         }
9696
9697         /* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9698         if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9699                 features &= ~NETIF_F_TSO_MANGLEID;
9700
9701         /* TSO ECN requires that TSO is present as well. */
9702         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9703                 features &= ~NETIF_F_TSO_ECN;
9704
9705         /* Software GSO depends on SG. */
9706         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9707                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9708                 features &= ~NETIF_F_GSO;
9709         }
9710
9711         /* GSO partial features require GSO partial be set */
9712         if ((features & dev->gso_partial_features) &&
9713             !(features & NETIF_F_GSO_PARTIAL)) {
9714                 netdev_dbg(dev,
9715                            "Dropping partially supported GSO features since no GSO partial.\n");
9716                 features &= ~dev->gso_partial_features;
9717         }
9718
9719         if (!(features & NETIF_F_RXCSUM)) {
9720                 /* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9721                  * successfully merged by hardware must also have the
9722                  * checksum verified by hardware.  If the user does not
9723                  * want to enable RXCSUM, logically, we should disable GRO_HW.
9724                  */
9725                 if (features & NETIF_F_GRO_HW) {
9726                         netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9727                         features &= ~NETIF_F_GRO_HW;
9728                 }
9729         }
9730
9731         /* LRO/HW-GRO features cannot be combined with RX-FCS */
9732         if (features & NETIF_F_RXFCS) {
9733                 if (features & NETIF_F_LRO) {
9734                         netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9735                         features &= ~NETIF_F_LRO;
9736                 }
9737
9738                 if (features & NETIF_F_GRO_HW) {
9739                         netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9740                         features &= ~NETIF_F_GRO_HW;
9741                 }
9742         }
9743
9744         if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9745                 netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9746                 features &= ~NETIF_F_LRO;
9747         }
9748
9749         if (features & NETIF_F_HW_TLS_TX) {
9750                 bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9751                         (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9752                 bool hw_csum = features & NETIF_F_HW_CSUM;
9753
9754                 if (!ip_csum && !hw_csum) {
9755                         netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9756                         features &= ~NETIF_F_HW_TLS_TX;
9757                 }
9758         }
9759
9760         if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9761                 netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9762                 features &= ~NETIF_F_HW_TLS_RX;
9763         }
9764
9765         return features;
9766 }
9767
9768 int __netdev_update_features(struct net_device *dev)
9769 {
9770         struct net_device *upper, *lower;
9771         netdev_features_t features;
9772         struct list_head *iter;
9773         int err = -1;
9774
9775         ASSERT_RTNL();
9776
9777         features = netdev_get_wanted_features(dev);
9778
9779         if (dev->netdev_ops->ndo_fix_features)
9780                 features = dev->netdev_ops->ndo_fix_features(dev, features);
9781
9782         /* driver might be less strict about feature dependencies */
9783         features = netdev_fix_features(dev, features);
9784
9785         /* some features can't be enabled if they're off on an upper device */
9786         netdev_for_each_upper_dev_rcu(dev, upper, iter)
9787                 features = netdev_sync_upper_features(dev, upper, features);
9788
9789         if (dev->features == features)
9790                 goto sync_lower;
9791
9792         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9793                 &dev->features, &features);
9794
9795         if (dev->netdev_ops->ndo_set_features)
9796                 err = dev->netdev_ops->ndo_set_features(dev, features);
9797         else
9798                 err = 0;
9799
9800         if (unlikely(err < 0)) {
9801                 netdev_err(dev,
9802                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
9803                         err, &features, &dev->features);
9804                 /* return non-0 since some features might have changed and
9805                  * it's better to fire a spurious notification than miss it
9806                  */
9807                 return -1;
9808         }
9809
9810 sync_lower:
9811         /* some features must be disabled on lower devices when disabled
9812          * on an upper device (think: bonding master or bridge)
9813          */
9814         netdev_for_each_lower_dev(dev, lower, iter)
9815                 netdev_sync_lower_features(dev, lower, features);
9816
9817         if (!err) {
9818                 netdev_features_t diff = features ^ dev->features;
9819
9820                 if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9821                         /* udp_tunnel_{get,drop}_rx_info both need
9822                          * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9823                          * device, or they won't do anything.
9824                          * Thus we need to update dev->features
9825                          * *before* calling udp_tunnel_get_rx_info,
9826                          * but *after* calling udp_tunnel_drop_rx_info.
9827                          */
9828                         if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9829                                 dev->features = features;
9830                                 udp_tunnel_get_rx_info(dev);
9831                         } else {
9832                                 udp_tunnel_drop_rx_info(dev);
9833                         }
9834                 }
9835
9836                 if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9837                         if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9838                                 dev->features = features;
9839                                 err |= vlan_get_rx_ctag_filter_info(dev);
9840                         } else {
9841                                 vlan_drop_rx_ctag_filter_info(dev);
9842                         }
9843                 }
9844
9845                 if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9846                         if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9847                                 dev->features = features;
9848                                 err |= vlan_get_rx_stag_filter_info(dev);
9849                         } else {
9850                                 vlan_drop_rx_stag_filter_info(dev);
9851                         }
9852                 }
9853
9854                 dev->features = features;
9855         }
9856
9857         return err < 0 ? 0 : 1;
9858 }
9859
9860 /**
9861  *      netdev_update_features - recalculate device features
9862  *      @dev: the device to check
9863  *
9864  *      Recalculate dev->features set and send notifications if it
9865  *      has changed. Should be called after driver or hardware dependent
9866  *      conditions might have changed that influence the features.
9867  */
9868 void netdev_update_features(struct net_device *dev)
9869 {
9870         if (__netdev_update_features(dev))
9871                 netdev_features_change(dev);
9872 }
9873 EXPORT_SYMBOL(netdev_update_features);
9874
9875 /**
9876  *      netdev_change_features - recalculate device features
9877  *      @dev: the device to check
9878  *
9879  *      Recalculate dev->features set and send notifications even
9880  *      if they have not changed. Should be called instead of
9881  *      netdev_update_features() if also dev->vlan_features might
9882  *      have changed to allow the changes to be propagated to stacked
9883  *      VLAN devices.
9884  */
9885 void netdev_change_features(struct net_device *dev)
9886 {
9887         __netdev_update_features(dev);
9888         netdev_features_change(dev);
9889 }
9890 EXPORT_SYMBOL(netdev_change_features);
9891
9892 /**
9893  *      netif_stacked_transfer_operstate -      transfer operstate
9894  *      @rootdev: the root or lower level device to transfer state from
9895  *      @dev: the device to transfer operstate to
9896  *
9897  *      Transfer operational state from root to device. This is normally
9898  *      called when a stacking relationship exists between the root
9899  *      device and the device(a leaf device).
9900  */
9901 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9902                                         struct net_device *dev)
9903 {
9904         if (rootdev->operstate == IF_OPER_DORMANT)
9905                 netif_dormant_on(dev);
9906         else
9907                 netif_dormant_off(dev);
9908
9909         if (rootdev->operstate == IF_OPER_TESTING)
9910                 netif_testing_on(dev);
9911         else
9912                 netif_testing_off(dev);
9913
9914         if (netif_carrier_ok(rootdev))
9915                 netif_carrier_on(dev);
9916         else
9917                 netif_carrier_off(dev);
9918 }
9919 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9920
9921 static int netif_alloc_rx_queues(struct net_device *dev)
9922 {
9923         unsigned int i, count = dev->num_rx_queues;
9924         struct netdev_rx_queue *rx;
9925         size_t sz = count * sizeof(*rx);
9926         int err = 0;
9927
9928         BUG_ON(count < 1);
9929
9930         rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9931         if (!rx)
9932                 return -ENOMEM;
9933
9934         dev->_rx = rx;
9935
9936         for (i = 0; i < count; i++) {
9937                 rx[i].dev = dev;
9938
9939                 /* XDP RX-queue setup */
9940                 err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9941                 if (err < 0)
9942                         goto err_rxq_info;
9943         }
9944         return 0;
9945
9946 err_rxq_info:
9947         /* Rollback successful reg's and free other resources */
9948         while (i--)
9949                 xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9950         kvfree(dev->_rx);
9951         dev->_rx = NULL;
9952         return err;
9953 }
9954
9955 static void netif_free_rx_queues(struct net_device *dev)
9956 {
9957         unsigned int i, count = dev->num_rx_queues;
9958
9959         /* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9960         if (!dev->_rx)
9961                 return;
9962
9963         for (i = 0; i < count; i++)
9964                 xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9965
9966         kvfree(dev->_rx);
9967 }
9968
9969 static void netdev_init_one_queue(struct net_device *dev,
9970                                   struct netdev_queue *queue, void *_unused)
9971 {
9972         /* Initialize queue lock */
9973         spin_lock_init(&queue->_xmit_lock);
9974         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9975         queue->xmit_lock_owner = -1;
9976         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9977         queue->dev = dev;
9978 #ifdef CONFIG_BQL
9979         dql_init(&queue->dql, HZ);
9980 #endif
9981 }
9982
9983 static void netif_free_tx_queues(struct net_device *dev)
9984 {
9985         kvfree(dev->_tx);
9986 }
9987
9988 static int netif_alloc_netdev_queues(struct net_device *dev)
9989 {
9990         unsigned int count = dev->num_tx_queues;
9991         struct netdev_queue *tx;
9992         size_t sz = count * sizeof(*tx);
9993
9994         if (count < 1 || count > 0xffff)
9995                 return -EINVAL;
9996
9997         tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9998         if (!tx)
9999                 return -ENOMEM;
10000
10001         dev->_tx = tx;
10002
10003         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
10004         spin_lock_init(&dev->tx_global_lock);
10005
10006         return 0;
10007 }
10008
10009 void netif_tx_stop_all_queues(struct net_device *dev)
10010 {
10011         unsigned int i;
10012
10013         for (i = 0; i < dev->num_tx_queues; i++) {
10014                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
10015
10016                 netif_tx_stop_queue(txq);
10017         }
10018 }
10019 EXPORT_SYMBOL(netif_tx_stop_all_queues);
10020
10021 /**
10022  * register_netdevice() - register a network device
10023  * @dev: device to register
10024  *
10025  * Take a prepared network device structure and make it externally accessible.
10026  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
10027  * Callers must hold the rtnl lock - you may want register_netdev()
10028  * instead of this.
10029  */
10030 int register_netdevice(struct net_device *dev)
10031 {
10032         int ret;
10033         struct net *net = dev_net(dev);
10034
10035         BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
10036                      NETDEV_FEATURE_COUNT);
10037         BUG_ON(dev_boot_phase);
10038         ASSERT_RTNL();
10039
10040         might_sleep();
10041
10042         /* When net_device's are persistent, this will be fatal. */
10043         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
10044         BUG_ON(!net);
10045
10046         ret = ethtool_check_ops(dev->ethtool_ops);
10047         if (ret)
10048                 return ret;
10049
10050         spin_lock_init(&dev->addr_list_lock);
10051         netdev_set_addr_lockdep_class(dev);
10052
10053         ret = dev_get_valid_name(net, dev, dev->name);
10054         if (ret < 0)
10055                 goto out;
10056
10057         ret = -ENOMEM;
10058         dev->name_node = netdev_name_node_head_alloc(dev);
10059         if (!dev->name_node)
10060                 goto out;
10061
10062         /* Init, if this function is available */
10063         if (dev->netdev_ops->ndo_init) {
10064                 ret = dev->netdev_ops->ndo_init(dev);
10065                 if (ret) {
10066                         if (ret > 0)
10067                                 ret = -EIO;
10068                         goto err_free_name;
10069                 }
10070         }
10071
10072         if (((dev->hw_features | dev->features) &
10073              NETIF_F_HW_VLAN_CTAG_FILTER) &&
10074             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10075              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10076                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10077                 ret = -EINVAL;
10078                 goto err_uninit;
10079         }
10080
10081         ret = dev_index_reserve(net, dev->ifindex);
10082         if (ret < 0)
10083                 goto err_uninit;
10084         dev->ifindex = ret;
10085
10086         /* Transfer changeable features to wanted_features and enable
10087          * software offloads (GSO and GRO).
10088          */
10089         dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10090         dev->features |= NETIF_F_SOFT_FEATURES;
10091
10092         if (dev->udp_tunnel_nic_info) {
10093                 dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10094                 dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10095         }
10096
10097         dev->wanted_features = dev->features & dev->hw_features;
10098
10099         if (!(dev->flags & IFF_LOOPBACK))
10100                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
10101
10102         /* If IPv4 TCP segmentation offload is supported we should also
10103          * allow the device to enable segmenting the frame with the option
10104          * of ignoring a static IP ID value.  This doesn't enable the
10105          * feature itself but allows the user to enable it later.
10106          */
10107         if (dev->hw_features & NETIF_F_TSO)
10108                 dev->hw_features |= NETIF_F_TSO_MANGLEID;
10109         if (dev->vlan_features & NETIF_F_TSO)
10110                 dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10111         if (dev->mpls_features & NETIF_F_TSO)
10112                 dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10113         if (dev->hw_enc_features & NETIF_F_TSO)
10114                 dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10115
10116         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10117          */
10118         dev->vlan_features |= NETIF_F_HIGHDMA;
10119
10120         /* Make NETIF_F_SG inheritable to tunnel devices.
10121          */
10122         dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10123
10124         /* Make NETIF_F_SG inheritable to MPLS.
10125          */
10126         dev->mpls_features |= NETIF_F_SG;
10127
10128         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10129         ret = notifier_to_errno(ret);
10130         if (ret)
10131                 goto err_ifindex_release;
10132
10133         ret = netdev_register_kobject(dev);
10134         write_lock(&dev_base_lock);
10135         dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10136         write_unlock(&dev_base_lock);
10137         if (ret)
10138                 goto err_uninit_notify;
10139
10140         __netdev_update_features(dev);
10141
10142         /*
10143          *      Default initial state at registry is that the
10144          *      device is present.
10145          */
10146
10147         set_bit(__LINK_STATE_PRESENT, &dev->state);
10148
10149         linkwatch_init_dev(dev);
10150
10151         dev_init_scheduler(dev);
10152
10153         netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10154         list_netdevice(dev);
10155
10156         add_device_randomness(dev->dev_addr, dev->addr_len);
10157
10158         /* If the device has permanent device address, driver should
10159          * set dev_addr and also addr_assign_type should be set to
10160          * NET_ADDR_PERM (default value).
10161          */
10162         if (dev->addr_assign_type == NET_ADDR_PERM)
10163                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10164
10165         /* Notify protocols, that a new device appeared. */
10166         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10167         ret = notifier_to_errno(ret);
10168         if (ret) {
10169                 /* Expect explicit free_netdev() on failure */
10170                 dev->needs_free_netdev = false;
10171                 unregister_netdevice_queue(dev, NULL);
10172                 goto out;
10173         }
10174         /*
10175          *      Prevent userspace races by waiting until the network
10176          *      device is fully setup before sending notifications.
10177          */
10178         if (!dev->rtnl_link_ops ||
10179             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10180                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10181
10182 out:
10183         return ret;
10184
10185 err_uninit_notify:
10186         call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10187 err_ifindex_release:
10188         dev_index_release(net, dev->ifindex);
10189 err_uninit:
10190         if (dev->netdev_ops->ndo_uninit)
10191                 dev->netdev_ops->ndo_uninit(dev);
10192         if (dev->priv_destructor)
10193                 dev->priv_destructor(dev);
10194 err_free_name:
10195         netdev_name_node_free(dev->name_node);
10196         goto out;
10197 }
10198 EXPORT_SYMBOL(register_netdevice);
10199
10200 /**
10201  *      init_dummy_netdev       - init a dummy network device for NAPI
10202  *      @dev: device to init
10203  *
10204  *      This takes a network device structure and initialize the minimum
10205  *      amount of fields so it can be used to schedule NAPI polls without
10206  *      registering a full blown interface. This is to be used by drivers
10207  *      that need to tie several hardware interfaces to a single NAPI
10208  *      poll scheduler due to HW limitations.
10209  */
10210 int init_dummy_netdev(struct net_device *dev)
10211 {
10212         /* Clear everything. Note we don't initialize spinlocks
10213          * are they aren't supposed to be taken by any of the
10214          * NAPI code and this dummy netdev is supposed to be
10215          * only ever used for NAPI polls
10216          */
10217         memset(dev, 0, sizeof(struct net_device));
10218
10219         /* make sure we BUG if trying to hit standard
10220          * register/unregister code path
10221          */
10222         dev->reg_state = NETREG_DUMMY;
10223
10224         /* NAPI wants this */
10225         INIT_LIST_HEAD(&dev->napi_list);
10226
10227         /* a dummy interface is started by default */
10228         set_bit(__LINK_STATE_PRESENT, &dev->state);
10229         set_bit(__LINK_STATE_START, &dev->state);
10230
10231         /* napi_busy_loop stats accounting wants this */
10232         dev_net_set(dev, &init_net);
10233
10234         /* Note : We dont allocate pcpu_refcnt for dummy devices,
10235          * because users of this 'device' dont need to change
10236          * its refcount.
10237          */
10238
10239         return 0;
10240 }
10241 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10242
10243
10244 /**
10245  *      register_netdev - register a network device
10246  *      @dev: device to register
10247  *
10248  *      Take a completed network device structure and add it to the kernel
10249  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10250  *      chain. 0 is returned on success. A negative errno code is returned
10251  *      on a failure to set up the device, or if the name is a duplicate.
10252  *
10253  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
10254  *      and expands the device name if you passed a format string to
10255  *      alloc_netdev.
10256  */
10257 int register_netdev(struct net_device *dev)
10258 {
10259         int err;
10260
10261         if (rtnl_lock_killable())
10262                 return -EINTR;
10263         err = register_netdevice(dev);
10264         rtnl_unlock();
10265         return err;
10266 }
10267 EXPORT_SYMBOL(register_netdev);
10268
10269 int netdev_refcnt_read(const struct net_device *dev)
10270 {
10271 #ifdef CONFIG_PCPU_DEV_REFCNT
10272         int i, refcnt = 0;
10273
10274         for_each_possible_cpu(i)
10275                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10276         return refcnt;
10277 #else
10278         return refcount_read(&dev->dev_refcnt);
10279 #endif
10280 }
10281 EXPORT_SYMBOL(netdev_refcnt_read);
10282
10283 int netdev_unregister_timeout_secs __read_mostly = 10;
10284
10285 #define WAIT_REFS_MIN_MSECS 1
10286 #define WAIT_REFS_MAX_MSECS 250
10287 /**
10288  * netdev_wait_allrefs_any - wait until all references are gone.
10289  * @list: list of net_devices to wait on
10290  *
10291  * This is called when unregistering network devices.
10292  *
10293  * Any protocol or device that holds a reference should register
10294  * for netdevice notification, and cleanup and put back the
10295  * reference if they receive an UNREGISTER event.
10296  * We can get stuck here if buggy protocols don't correctly
10297  * call dev_put.
10298  */
10299 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10300 {
10301         unsigned long rebroadcast_time, warning_time;
10302         struct net_device *dev;
10303         int wait = 0;
10304
10305         rebroadcast_time = warning_time = jiffies;
10306
10307         list_for_each_entry(dev, list, todo_list)
10308                 if (netdev_refcnt_read(dev) == 1)
10309                         return dev;
10310
10311         while (true) {
10312                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10313                         rtnl_lock();
10314
10315                         /* Rebroadcast unregister notification */
10316                         list_for_each_entry(dev, list, todo_list)
10317                                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10318
10319                         __rtnl_unlock();
10320                         rcu_barrier();
10321                         rtnl_lock();
10322
10323                         list_for_each_entry(dev, list, todo_list)
10324                                 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10325                                              &dev->state)) {
10326                                         /* We must not have linkwatch events
10327                                          * pending on unregister. If this
10328                                          * happens, we simply run the queue
10329                                          * unscheduled, resulting in a noop
10330                                          * for this device.
10331                                          */
10332                                         linkwatch_run_queue();
10333                                         break;
10334                                 }
10335
10336                         __rtnl_unlock();
10337
10338                         rebroadcast_time = jiffies;
10339                 }
10340
10341                 if (!wait) {
10342                         rcu_barrier();
10343                         wait = WAIT_REFS_MIN_MSECS;
10344                 } else {
10345                         msleep(wait);
10346                         wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10347                 }
10348
10349                 list_for_each_entry(dev, list, todo_list)
10350                         if (netdev_refcnt_read(dev) == 1)
10351                                 return dev;
10352
10353                 if (time_after(jiffies, warning_time +
10354                                READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10355                         list_for_each_entry(dev, list, todo_list) {
10356                                 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10357                                          dev->name, netdev_refcnt_read(dev));
10358                                 ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10359                         }
10360
10361                         warning_time = jiffies;
10362                 }
10363         }
10364 }
10365
10366 /* The sequence is:
10367  *
10368  *      rtnl_lock();
10369  *      ...
10370  *      register_netdevice(x1);
10371  *      register_netdevice(x2);
10372  *      ...
10373  *      unregister_netdevice(y1);
10374  *      unregister_netdevice(y2);
10375  *      ...
10376  *      rtnl_unlock();
10377  *      free_netdev(y1);
10378  *      free_netdev(y2);
10379  *
10380  * We are invoked by rtnl_unlock().
10381  * This allows us to deal with problems:
10382  * 1) We can delete sysfs objects which invoke hotplug
10383  *    without deadlocking with linkwatch via keventd.
10384  * 2) Since we run with the RTNL semaphore not held, we can sleep
10385  *    safely in order to wait for the netdev refcnt to drop to zero.
10386  *
10387  * We must not return until all unregister events added during
10388  * the interval the lock was held have been completed.
10389  */
10390 void netdev_run_todo(void)
10391 {
10392         struct net_device *dev, *tmp;
10393         struct list_head list;
10394 #ifdef CONFIG_LOCKDEP
10395         struct list_head unlink_list;
10396
10397         list_replace_init(&net_unlink_list, &unlink_list);
10398
10399         while (!list_empty(&unlink_list)) {
10400                 struct net_device *dev = list_first_entry(&unlink_list,
10401                                                           struct net_device,
10402                                                           unlink_list);
10403                 list_del_init(&dev->unlink_list);
10404                 dev->nested_level = dev->lower_level - 1;
10405         }
10406 #endif
10407
10408         /* Snapshot list, allow later requests */
10409         list_replace_init(&net_todo_list, &list);
10410
10411         __rtnl_unlock();
10412
10413         /* Wait for rcu callbacks to finish before next phase */
10414         if (!list_empty(&list))
10415                 rcu_barrier();
10416
10417         list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10418                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10419                         netdev_WARN(dev, "run_todo but not unregistering\n");
10420                         list_del(&dev->todo_list);
10421                         continue;
10422                 }
10423
10424                 write_lock(&dev_base_lock);
10425                 dev->reg_state = NETREG_UNREGISTERED;
10426                 write_unlock(&dev_base_lock);
10427                 linkwatch_forget_dev(dev);
10428         }
10429
10430         while (!list_empty(&list)) {
10431                 dev = netdev_wait_allrefs_any(&list);
10432                 list_del(&dev->todo_list);
10433
10434                 /* paranoia */
10435                 BUG_ON(netdev_refcnt_read(dev) != 1);
10436                 BUG_ON(!list_empty(&dev->ptype_all));
10437                 BUG_ON(!list_empty(&dev->ptype_specific));
10438                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
10439                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10440
10441                 if (dev->priv_destructor)
10442                         dev->priv_destructor(dev);
10443                 if (dev->needs_free_netdev)
10444                         free_netdev(dev);
10445
10446                 if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10447                         wake_up(&netdev_unregistering_wq);
10448
10449                 /* Free network device */
10450                 kobject_put(&dev->dev.kobj);
10451         }
10452 }
10453
10454 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10455  * all the same fields in the same order as net_device_stats, with only
10456  * the type differing, but rtnl_link_stats64 may have additional fields
10457  * at the end for newer counters.
10458  */
10459 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10460                              const struct net_device_stats *netdev_stats)
10461 {
10462         size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10463         const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10464         u64 *dst = (u64 *)stats64;
10465
10466         BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10467         for (i = 0; i < n; i++)
10468                 dst[i] = (unsigned long)atomic_long_read(&src[i]);
10469         /* zero out counters that only exist in rtnl_link_stats64 */
10470         memset((char *)stats64 + n * sizeof(u64), 0,
10471                sizeof(*stats64) - n * sizeof(u64));
10472 }
10473 EXPORT_SYMBOL(netdev_stats_to_stats64);
10474
10475 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10476 {
10477         struct net_device_core_stats __percpu *p;
10478
10479         p = alloc_percpu_gfp(struct net_device_core_stats,
10480                              GFP_ATOMIC | __GFP_NOWARN);
10481
10482         if (p && cmpxchg(&dev->core_stats, NULL, p))
10483                 free_percpu(p);
10484
10485         /* This READ_ONCE() pairs with the cmpxchg() above */
10486         return READ_ONCE(dev->core_stats);
10487 }
10488 EXPORT_SYMBOL(netdev_core_stats_alloc);
10489
10490 /**
10491  *      dev_get_stats   - get network device statistics
10492  *      @dev: device to get statistics from
10493  *      @storage: place to store stats
10494  *
10495  *      Get network statistics from device. Return @storage.
10496  *      The device driver may provide its own method by setting
10497  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10498  *      otherwise the internal statistics structure is used.
10499  */
10500 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10501                                         struct rtnl_link_stats64 *storage)
10502 {
10503         const struct net_device_ops *ops = dev->netdev_ops;
10504         const struct net_device_core_stats __percpu *p;
10505
10506         if (ops->ndo_get_stats64) {
10507                 memset(storage, 0, sizeof(*storage));
10508                 ops->ndo_get_stats64(dev, storage);
10509         } else if (ops->ndo_get_stats) {
10510                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10511         } else {
10512                 netdev_stats_to_stats64(storage, &dev->stats);
10513         }
10514
10515         /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10516         p = READ_ONCE(dev->core_stats);
10517         if (p) {
10518                 const struct net_device_core_stats *core_stats;
10519                 int i;
10520
10521                 for_each_possible_cpu(i) {
10522                         core_stats = per_cpu_ptr(p, i);
10523                         storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10524                         storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10525                         storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10526                         storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10527                 }
10528         }
10529         return storage;
10530 }
10531 EXPORT_SYMBOL(dev_get_stats);
10532
10533 /**
10534  *      dev_fetch_sw_netstats - get per-cpu network device statistics
10535  *      @s: place to store stats
10536  *      @netstats: per-cpu network stats to read from
10537  *
10538  *      Read per-cpu network statistics and populate the related fields in @s.
10539  */
10540 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10541                            const struct pcpu_sw_netstats __percpu *netstats)
10542 {
10543         int cpu;
10544
10545         for_each_possible_cpu(cpu) {
10546                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10547                 const struct pcpu_sw_netstats *stats;
10548                 unsigned int start;
10549
10550                 stats = per_cpu_ptr(netstats, cpu);
10551                 do {
10552                         start = u64_stats_fetch_begin(&stats->syncp);
10553                         rx_packets = u64_stats_read(&stats->rx_packets);
10554                         rx_bytes   = u64_stats_read(&stats->rx_bytes);
10555                         tx_packets = u64_stats_read(&stats->tx_packets);
10556                         tx_bytes   = u64_stats_read(&stats->tx_bytes);
10557                 } while (u64_stats_fetch_retry(&stats->syncp, start));
10558
10559                 s->rx_packets += rx_packets;
10560                 s->rx_bytes   += rx_bytes;
10561                 s->tx_packets += tx_packets;
10562                 s->tx_bytes   += tx_bytes;
10563         }
10564 }
10565 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10566
10567 /**
10568  *      dev_get_tstats64 - ndo_get_stats64 implementation
10569  *      @dev: device to get statistics from
10570  *      @s: place to store stats
10571  *
10572  *      Populate @s from dev->stats and dev->tstats. Can be used as
10573  *      ndo_get_stats64() callback.
10574  */
10575 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10576 {
10577         netdev_stats_to_stats64(s, &dev->stats);
10578         dev_fetch_sw_netstats(s, dev->tstats);
10579 }
10580 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10581
10582 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10583 {
10584         struct netdev_queue *queue = dev_ingress_queue(dev);
10585
10586 #ifdef CONFIG_NET_CLS_ACT
10587         if (queue)
10588                 return queue;
10589         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10590         if (!queue)
10591                 return NULL;
10592         netdev_init_one_queue(dev, queue, NULL);
10593         RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10594         RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
10595         rcu_assign_pointer(dev->ingress_queue, queue);
10596 #endif
10597         return queue;
10598 }
10599
10600 static const struct ethtool_ops default_ethtool_ops;
10601
10602 void netdev_set_default_ethtool_ops(struct net_device *dev,
10603                                     const struct ethtool_ops *ops)
10604 {
10605         if (dev->ethtool_ops == &default_ethtool_ops)
10606                 dev->ethtool_ops = ops;
10607 }
10608 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10609
10610 /**
10611  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10612  * @dev: netdev to enable the IRQ coalescing on
10613  *
10614  * Sets a conservative default for SW IRQ coalescing. Users can use
10615  * sysfs attributes to override the default values.
10616  */
10617 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10618 {
10619         WARN_ON(dev->reg_state == NETREG_REGISTERED);
10620
10621         if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
10622                 dev->gro_flush_timeout = 20000;
10623                 dev->napi_defer_hard_irqs = 1;
10624         }
10625 }
10626 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10627
10628 void netdev_freemem(struct net_device *dev)
10629 {
10630         char *addr = (char *)dev - dev->padded;
10631
10632         kvfree(addr);
10633 }
10634
10635 /**
10636  * alloc_netdev_mqs - allocate network device
10637  * @sizeof_priv: size of private data to allocate space for
10638  * @name: device name format string
10639  * @name_assign_type: origin of device name
10640  * @setup: callback to initialize device
10641  * @txqs: the number of TX subqueues to allocate
10642  * @rxqs: the number of RX subqueues to allocate
10643  *
10644  * Allocates a struct net_device with private data area for driver use
10645  * and performs basic initialization.  Also allocates subqueue structs
10646  * for each queue on the device.
10647  */
10648 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10649                 unsigned char name_assign_type,
10650                 void (*setup)(struct net_device *),
10651                 unsigned int txqs, unsigned int rxqs)
10652 {
10653         struct net_device *dev;
10654         unsigned int alloc_size;
10655         struct net_device *p;
10656
10657         BUG_ON(strlen(name) >= sizeof(dev->name));
10658
10659         if (txqs < 1) {
10660                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10661                 return NULL;
10662         }
10663
10664         if (rxqs < 1) {
10665                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10666                 return NULL;
10667         }
10668
10669         alloc_size = sizeof(struct net_device);
10670         if (sizeof_priv) {
10671                 /* ensure 32-byte alignment of private area */
10672                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10673                 alloc_size += sizeof_priv;
10674         }
10675         /* ensure 32-byte alignment of whole construct */
10676         alloc_size += NETDEV_ALIGN - 1;
10677
10678         p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10679         if (!p)
10680                 return NULL;
10681
10682         dev = PTR_ALIGN(p, NETDEV_ALIGN);
10683         dev->padded = (char *)dev - (char *)p;
10684
10685         ref_tracker_dir_init(&dev->refcnt_tracker, 128, name);
10686 #ifdef CONFIG_PCPU_DEV_REFCNT
10687         dev->pcpu_refcnt = alloc_percpu(int);
10688         if (!dev->pcpu_refcnt)
10689                 goto free_dev;
10690         __dev_hold(dev);
10691 #else
10692         refcount_set(&dev->dev_refcnt, 1);
10693 #endif
10694
10695         if (dev_addr_init(dev))
10696                 goto free_pcpu;
10697
10698         dev_mc_init(dev);
10699         dev_uc_init(dev);
10700
10701         dev_net_set(dev, &init_net);
10702
10703         dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10704         dev->xdp_zc_max_segs = 1;
10705         dev->gso_max_segs = GSO_MAX_SEGS;
10706         dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10707         dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10708         dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10709         dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10710         dev->tso_max_segs = TSO_MAX_SEGS;
10711         dev->upper_level = 1;
10712         dev->lower_level = 1;
10713 #ifdef CONFIG_LOCKDEP
10714         dev->nested_level = 0;
10715         INIT_LIST_HEAD(&dev->unlink_list);
10716 #endif
10717
10718         INIT_LIST_HEAD(&dev->napi_list);
10719         INIT_LIST_HEAD(&dev->unreg_list);
10720         INIT_LIST_HEAD(&dev->close_list);
10721         INIT_LIST_HEAD(&dev->link_watch_list);
10722         INIT_LIST_HEAD(&dev->adj_list.upper);
10723         INIT_LIST_HEAD(&dev->adj_list.lower);
10724         INIT_LIST_HEAD(&dev->ptype_all);
10725         INIT_LIST_HEAD(&dev->ptype_specific);
10726         INIT_LIST_HEAD(&dev->net_notifier_list);
10727 #ifdef CONFIG_NET_SCHED
10728         hash_init(dev->qdisc_hash);
10729 #endif
10730         dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10731         setup(dev);
10732
10733         if (!dev->tx_queue_len) {
10734                 dev->priv_flags |= IFF_NO_QUEUE;
10735                 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10736         }
10737
10738         dev->num_tx_queues = txqs;
10739         dev->real_num_tx_queues = txqs;
10740         if (netif_alloc_netdev_queues(dev))
10741                 goto free_all;
10742
10743         dev->num_rx_queues = rxqs;
10744         dev->real_num_rx_queues = rxqs;
10745         if (netif_alloc_rx_queues(dev))
10746                 goto free_all;
10747
10748         strcpy(dev->name, name);
10749         dev->name_assign_type = name_assign_type;
10750         dev->group = INIT_NETDEV_GROUP;
10751         if (!dev->ethtool_ops)
10752                 dev->ethtool_ops = &default_ethtool_ops;
10753
10754         nf_hook_netdev_init(dev);
10755
10756         return dev;
10757
10758 free_all:
10759         free_netdev(dev);
10760         return NULL;
10761
10762 free_pcpu:
10763 #ifdef CONFIG_PCPU_DEV_REFCNT
10764         free_percpu(dev->pcpu_refcnt);
10765 free_dev:
10766 #endif
10767         netdev_freemem(dev);
10768         return NULL;
10769 }
10770 EXPORT_SYMBOL(alloc_netdev_mqs);
10771
10772 /**
10773  * free_netdev - free network device
10774  * @dev: device
10775  *
10776  * This function does the last stage of destroying an allocated device
10777  * interface. The reference to the device object is released. If this
10778  * is the last reference then it will be freed.Must be called in process
10779  * context.
10780  */
10781 void free_netdev(struct net_device *dev)
10782 {
10783         struct napi_struct *p, *n;
10784
10785         might_sleep();
10786
10787         /* When called immediately after register_netdevice() failed the unwind
10788          * handling may still be dismantling the device. Handle that case by
10789          * deferring the free.
10790          */
10791         if (dev->reg_state == NETREG_UNREGISTERING) {
10792                 ASSERT_RTNL();
10793                 dev->needs_free_netdev = true;
10794                 return;
10795         }
10796
10797         netif_free_tx_queues(dev);
10798         netif_free_rx_queues(dev);
10799
10800         kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10801
10802         /* Flush device addresses */
10803         dev_addr_flush(dev);
10804
10805         list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10806                 netif_napi_del(p);
10807
10808         ref_tracker_dir_exit(&dev->refcnt_tracker);
10809 #ifdef CONFIG_PCPU_DEV_REFCNT
10810         free_percpu(dev->pcpu_refcnt);
10811         dev->pcpu_refcnt = NULL;
10812 #endif
10813         free_percpu(dev->core_stats);
10814         dev->core_stats = NULL;
10815         free_percpu(dev->xdp_bulkq);
10816         dev->xdp_bulkq = NULL;
10817
10818         /*  Compatibility with error handling in drivers */
10819         if (dev->reg_state == NETREG_UNINITIALIZED) {
10820                 netdev_freemem(dev);
10821                 return;
10822         }
10823
10824         BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10825         dev->reg_state = NETREG_RELEASED;
10826
10827         /* will free via device release */
10828         put_device(&dev->dev);
10829 }
10830 EXPORT_SYMBOL(free_netdev);
10831
10832 /**
10833  *      synchronize_net -  Synchronize with packet receive processing
10834  *
10835  *      Wait for packets currently being received to be done.
10836  *      Does not block later packets from starting.
10837  */
10838 void synchronize_net(void)
10839 {
10840         might_sleep();
10841         if (rtnl_is_locked())
10842                 synchronize_rcu_expedited();
10843         else
10844                 synchronize_rcu();
10845 }
10846 EXPORT_SYMBOL(synchronize_net);
10847
10848 /**
10849  *      unregister_netdevice_queue - remove device from the kernel
10850  *      @dev: device
10851  *      @head: list
10852  *
10853  *      This function shuts down a device interface and removes it
10854  *      from the kernel tables.
10855  *      If head not NULL, device is queued to be unregistered later.
10856  *
10857  *      Callers must hold the rtnl semaphore.  You may want
10858  *      unregister_netdev() instead of this.
10859  */
10860
10861 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10862 {
10863         ASSERT_RTNL();
10864
10865         if (head) {
10866                 list_move_tail(&dev->unreg_list, head);
10867         } else {
10868                 LIST_HEAD(single);
10869
10870                 list_add(&dev->unreg_list, &single);
10871                 unregister_netdevice_many(&single);
10872         }
10873 }
10874 EXPORT_SYMBOL(unregister_netdevice_queue);
10875
10876 void unregister_netdevice_many_notify(struct list_head *head,
10877                                       u32 portid, const struct nlmsghdr *nlh)
10878 {
10879         struct net_device *dev, *tmp;
10880         LIST_HEAD(close_head);
10881
10882         BUG_ON(dev_boot_phase);
10883         ASSERT_RTNL();
10884
10885         if (list_empty(head))
10886                 return;
10887
10888         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10889                 /* Some devices call without registering
10890                  * for initialization unwind. Remove those
10891                  * devices and proceed with the remaining.
10892                  */
10893                 if (dev->reg_state == NETREG_UNINITIALIZED) {
10894                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10895                                  dev->name, dev);
10896
10897                         WARN_ON(1);
10898                         list_del(&dev->unreg_list);
10899                         continue;
10900                 }
10901                 dev->dismantle = true;
10902                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
10903         }
10904
10905         /* If device is running, close it first. */
10906         list_for_each_entry(dev, head, unreg_list)
10907                 list_add_tail(&dev->close_list, &close_head);
10908         dev_close_many(&close_head, true);
10909
10910         list_for_each_entry(dev, head, unreg_list) {
10911                 /* And unlink it from device chain. */
10912                 write_lock(&dev_base_lock);
10913                 unlist_netdevice(dev, false);
10914                 dev->reg_state = NETREG_UNREGISTERING;
10915                 write_unlock(&dev_base_lock);
10916         }
10917         flush_all_backlogs();
10918
10919         synchronize_net();
10920
10921         list_for_each_entry(dev, head, unreg_list) {
10922                 struct sk_buff *skb = NULL;
10923
10924                 /* Shutdown queueing discipline. */
10925                 dev_shutdown(dev);
10926                 dev_tcx_uninstall(dev);
10927                 dev_xdp_uninstall(dev);
10928                 bpf_dev_bound_netdev_unregister(dev);
10929
10930                 netdev_offload_xstats_disable_all(dev);
10931
10932                 /* Notify protocols, that we are about to destroy
10933                  * this device. They should clean all the things.
10934                  */
10935                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10936
10937                 if (!dev->rtnl_link_ops ||
10938                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10939                         skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10940                                                      GFP_KERNEL, NULL, 0,
10941                                                      portid, nlh);
10942
10943                 /*
10944                  *      Flush the unicast and multicast chains
10945                  */
10946                 dev_uc_flush(dev);
10947                 dev_mc_flush(dev);
10948
10949                 netdev_name_node_alt_flush(dev);
10950                 netdev_name_node_free(dev->name_node);
10951
10952                 call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10953
10954                 if (dev->netdev_ops->ndo_uninit)
10955                         dev->netdev_ops->ndo_uninit(dev);
10956
10957                 if (skb)
10958                         rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
10959
10960                 /* Notifier chain MUST detach us all upper devices. */
10961                 WARN_ON(netdev_has_any_upper_dev(dev));
10962                 WARN_ON(netdev_has_any_lower_dev(dev));
10963
10964                 /* Remove entries from kobject tree */
10965                 netdev_unregister_kobject(dev);
10966 #ifdef CONFIG_XPS
10967                 /* Remove XPS queueing entries */
10968                 netif_reset_xps_queues_gt(dev, 0);
10969 #endif
10970         }
10971
10972         synchronize_net();
10973
10974         list_for_each_entry(dev, head, unreg_list) {
10975                 netdev_put(dev, &dev->dev_registered_tracker);
10976                 net_set_todo(dev);
10977         }
10978
10979         list_del(head);
10980 }
10981
10982 /**
10983  *      unregister_netdevice_many - unregister many devices
10984  *      @head: list of devices
10985  *
10986  *  Note: As most callers use a stack allocated list_head,
10987  *  we force a list_del() to make sure stack wont be corrupted later.
10988  */
10989 void unregister_netdevice_many(struct list_head *head)
10990 {
10991         unregister_netdevice_many_notify(head, 0, NULL);
10992 }
10993 EXPORT_SYMBOL(unregister_netdevice_many);
10994
10995 /**
10996  *      unregister_netdev - remove device from the kernel
10997  *      @dev: device
10998  *
10999  *      This function shuts down a device interface and removes it
11000  *      from the kernel tables.
11001  *
11002  *      This is just a wrapper for unregister_netdevice that takes
11003  *      the rtnl semaphore.  In general you want to use this and not
11004  *      unregister_netdevice.
11005  */
11006 void unregister_netdev(struct net_device *dev)
11007 {
11008         rtnl_lock();
11009         unregister_netdevice(dev);
11010         rtnl_unlock();
11011 }
11012 EXPORT_SYMBOL(unregister_netdev);
11013
11014 /**
11015  *      __dev_change_net_namespace - move device to different nethost namespace
11016  *      @dev: device
11017  *      @net: network namespace
11018  *      @pat: If not NULL name pattern to try if the current device name
11019  *            is already taken in the destination network namespace.
11020  *      @new_ifindex: If not zero, specifies device index in the target
11021  *                    namespace.
11022  *
11023  *      This function shuts down a device interface and moves it
11024  *      to a new network namespace. On success 0 is returned, on
11025  *      a failure a netagive errno code is returned.
11026  *
11027  *      Callers must hold the rtnl semaphore.
11028  */
11029
11030 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
11031                                const char *pat, int new_ifindex)
11032 {
11033         struct net *net_old = dev_net(dev);
11034         int err, new_nsid;
11035
11036         ASSERT_RTNL();
11037
11038         /* Don't allow namespace local devices to be moved. */
11039         err = -EINVAL;
11040         if (dev->features & NETIF_F_NETNS_LOCAL)
11041                 goto out;
11042
11043         /* Ensure the device has been registrered */
11044         if (dev->reg_state != NETREG_REGISTERED)
11045                 goto out;
11046
11047         /* Get out if there is nothing todo */
11048         err = 0;
11049         if (net_eq(net_old, net))
11050                 goto out;
11051
11052         /* Pick the destination device name, and ensure
11053          * we can use it in the destination network namespace.
11054          */
11055         err = -EEXIST;
11056         if (netdev_name_in_use(net, dev->name)) {
11057                 /* We get here if we can't use the current device name */
11058                 if (!pat)
11059                         goto out;
11060                 err = dev_get_valid_name(net, dev, pat);
11061                 if (err < 0)
11062                         goto out;
11063         }
11064
11065         /* Check that new_ifindex isn't used yet. */
11066         if (new_ifindex) {
11067                 err = dev_index_reserve(net, new_ifindex);
11068                 if (err < 0)
11069                         goto out;
11070         } else {
11071                 /* If there is an ifindex conflict assign a new one */
11072                 err = dev_index_reserve(net, dev->ifindex);
11073                 if (err == -EBUSY)
11074                         err = dev_index_reserve(net, 0);
11075                 if (err < 0)
11076                         goto out;
11077                 new_ifindex = err;
11078         }
11079
11080         /*
11081          * And now a mini version of register_netdevice unregister_netdevice.
11082          */
11083
11084         /* If device is running close it first. */
11085         dev_close(dev);
11086
11087         /* And unlink it from device chain */
11088         unlist_netdevice(dev, true);
11089
11090         synchronize_net();
11091
11092         /* Shutdown queueing discipline. */
11093         dev_shutdown(dev);
11094
11095         /* Notify protocols, that we are about to destroy
11096          * this device. They should clean all the things.
11097          *
11098          * Note that dev->reg_state stays at NETREG_REGISTERED.
11099          * This is wanted because this way 8021q and macvlan know
11100          * the device is just moving and can keep their slaves up.
11101          */
11102         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11103         rcu_barrier();
11104
11105         new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11106
11107         rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11108                             new_ifindex);
11109
11110         /*
11111          *      Flush the unicast and multicast chains
11112          */
11113         dev_uc_flush(dev);
11114         dev_mc_flush(dev);
11115
11116         /* Send a netdev-removed uevent to the old namespace */
11117         kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11118         netdev_adjacent_del_links(dev);
11119
11120         /* Move per-net netdevice notifiers that are following the netdevice */
11121         move_netdevice_notifiers_dev_net(dev, net);
11122
11123         /* Actually switch the network namespace */
11124         dev_net_set(dev, net);
11125         dev->ifindex = new_ifindex;
11126
11127         /* Send a netdev-add uevent to the new namespace */
11128         kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11129         netdev_adjacent_add_links(dev);
11130
11131         /* Fixup kobjects */
11132         err = device_rename(&dev->dev, dev->name);
11133         WARN_ON(err);
11134
11135         /* Adapt owner in case owning user namespace of target network
11136          * namespace is different from the original one.
11137          */
11138         err = netdev_change_owner(dev, net_old, net);
11139         WARN_ON(err);
11140
11141         /* Add the device back in the hashes */
11142         list_netdevice(dev);
11143
11144         /* Notify protocols, that a new device appeared. */
11145         call_netdevice_notifiers(NETDEV_REGISTER, dev);
11146
11147         /*
11148          *      Prevent userspace races by waiting until the network
11149          *      device is fully setup before sending notifications.
11150          */
11151         rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11152
11153         synchronize_net();
11154         err = 0;
11155 out:
11156         return err;
11157 }
11158 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11159
11160 static int dev_cpu_dead(unsigned int oldcpu)
11161 {
11162         struct sk_buff **list_skb;
11163         struct sk_buff *skb;
11164         unsigned int cpu;
11165         struct softnet_data *sd, *oldsd, *remsd = NULL;
11166
11167         local_irq_disable();
11168         cpu = smp_processor_id();
11169         sd = &per_cpu(softnet_data, cpu);
11170         oldsd = &per_cpu(softnet_data, oldcpu);
11171
11172         /* Find end of our completion_queue. */
11173         list_skb = &sd->completion_queue;
11174         while (*list_skb)
11175                 list_skb = &(*list_skb)->next;
11176         /* Append completion queue from offline CPU. */
11177         *list_skb = oldsd->completion_queue;
11178         oldsd->completion_queue = NULL;
11179
11180         /* Append output queue from offline CPU. */
11181         if (oldsd->output_queue) {
11182                 *sd->output_queue_tailp = oldsd->output_queue;
11183                 sd->output_queue_tailp = oldsd->output_queue_tailp;
11184                 oldsd->output_queue = NULL;
11185                 oldsd->output_queue_tailp = &oldsd->output_queue;
11186         }
11187         /* Append NAPI poll list from offline CPU, with one exception :
11188          * process_backlog() must be called by cpu owning percpu backlog.
11189          * We properly handle process_queue & input_pkt_queue later.
11190          */
11191         while (!list_empty(&oldsd->poll_list)) {
11192                 struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11193                                                             struct napi_struct,
11194                                                             poll_list);
11195
11196                 list_del_init(&napi->poll_list);
11197                 if (napi->poll == process_backlog)
11198                         napi->state = 0;
11199                 else
11200                         ____napi_schedule(sd, napi);
11201         }
11202
11203         raise_softirq_irqoff(NET_TX_SOFTIRQ);
11204         local_irq_enable();
11205
11206 #ifdef CONFIG_RPS
11207         remsd = oldsd->rps_ipi_list;
11208         oldsd->rps_ipi_list = NULL;
11209 #endif
11210         /* send out pending IPI's on offline CPU */
11211         net_rps_send_ipi(remsd);
11212
11213         /* Process offline CPU's input_pkt_queue */
11214         while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11215                 netif_rx(skb);
11216                 input_queue_head_incr(oldsd);
11217         }
11218         while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11219                 netif_rx(skb);
11220                 input_queue_head_incr(oldsd);
11221         }
11222
11223         return 0;
11224 }
11225
11226 /**
11227  *      netdev_increment_features - increment feature set by one
11228  *      @all: current feature set
11229  *      @one: new feature set
11230  *      @mask: mask feature set
11231  *
11232  *      Computes a new feature set after adding a device with feature set
11233  *      @one to the master device with current feature set @all.  Will not
11234  *      enable anything that is off in @mask. Returns the new feature set.
11235  */
11236 netdev_features_t netdev_increment_features(netdev_features_t all,
11237         netdev_features_t one, netdev_features_t mask)
11238 {
11239         if (mask & NETIF_F_HW_CSUM)
11240                 mask |= NETIF_F_CSUM_MASK;
11241         mask |= NETIF_F_VLAN_CHALLENGED;
11242
11243         all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11244         all &= one | ~NETIF_F_ALL_FOR_ALL;
11245
11246         /* If one device supports hw checksumming, set for all. */
11247         if (all & NETIF_F_HW_CSUM)
11248                 all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11249
11250         return all;
11251 }
11252 EXPORT_SYMBOL(netdev_increment_features);
11253
11254 static struct hlist_head * __net_init netdev_create_hash(void)
11255 {
11256         int i;
11257         struct hlist_head *hash;
11258
11259         hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11260         if (hash != NULL)
11261                 for (i = 0; i < NETDEV_HASHENTRIES; i++)
11262                         INIT_HLIST_HEAD(&hash[i]);
11263
11264         return hash;
11265 }
11266
11267 /* Initialize per network namespace state */
11268 static int __net_init netdev_init(struct net *net)
11269 {
11270         BUILD_BUG_ON(GRO_HASH_BUCKETS >
11271                      8 * sizeof_field(struct napi_struct, gro_bitmask));
11272
11273         INIT_LIST_HEAD(&net->dev_base_head);
11274
11275         net->dev_name_head = netdev_create_hash();
11276         if (net->dev_name_head == NULL)
11277                 goto err_name;
11278
11279         net->dev_index_head = netdev_create_hash();
11280         if (net->dev_index_head == NULL)
11281                 goto err_idx;
11282
11283         xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1);
11284
11285         RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11286
11287         return 0;
11288
11289 err_idx:
11290         kfree(net->dev_name_head);
11291 err_name:
11292         return -ENOMEM;
11293 }
11294
11295 /**
11296  *      netdev_drivername - network driver for the device
11297  *      @dev: network device
11298  *
11299  *      Determine network driver for device.
11300  */
11301 const char *netdev_drivername(const struct net_device *dev)
11302 {
11303         const struct device_driver *driver;
11304         const struct device *parent;
11305         const char *empty = "";
11306
11307         parent = dev->dev.parent;
11308         if (!parent)
11309                 return empty;
11310
11311         driver = parent->driver;
11312         if (driver && driver->name)
11313                 return driver->name;
11314         return empty;
11315 }
11316
11317 static void __netdev_printk(const char *level, const struct net_device *dev,
11318                             struct va_format *vaf)
11319 {
11320         if (dev && dev->dev.parent) {
11321                 dev_printk_emit(level[1] - '0',
11322                                 dev->dev.parent,
11323                                 "%s %s %s%s: %pV",
11324                                 dev_driver_string(dev->dev.parent),
11325                                 dev_name(dev->dev.parent),
11326                                 netdev_name(dev), netdev_reg_state(dev),
11327                                 vaf);
11328         } else if (dev) {
11329                 printk("%s%s%s: %pV",
11330                        level, netdev_name(dev), netdev_reg_state(dev), vaf);
11331         } else {
11332                 printk("%s(NULL net_device): %pV", level, vaf);
11333         }
11334 }
11335
11336 void netdev_printk(const char *level, const struct net_device *dev,
11337                    const char *format, ...)
11338 {
11339         struct va_format vaf;
11340         va_list args;
11341
11342         va_start(args, format);
11343
11344         vaf.fmt = format;
11345         vaf.va = &args;
11346
11347         __netdev_printk(level, dev, &vaf);
11348
11349         va_end(args);
11350 }
11351 EXPORT_SYMBOL(netdev_printk);
11352
11353 #define define_netdev_printk_level(func, level)                 \
11354 void func(const struct net_device *dev, const char *fmt, ...)   \
11355 {                                                               \
11356         struct va_format vaf;                                   \
11357         va_list args;                                           \
11358                                                                 \
11359         va_start(args, fmt);                                    \
11360                                                                 \
11361         vaf.fmt = fmt;                                          \
11362         vaf.va = &args;                                         \
11363                                                                 \
11364         __netdev_printk(level, dev, &vaf);                      \
11365                                                                 \
11366         va_end(args);                                           \
11367 }                                                               \
11368 EXPORT_SYMBOL(func);
11369
11370 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11371 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11372 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11373 define_netdev_printk_level(netdev_err, KERN_ERR);
11374 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11375 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11376 define_netdev_printk_level(netdev_info, KERN_INFO);
11377
11378 static void __net_exit netdev_exit(struct net *net)
11379 {
11380         kfree(net->dev_name_head);
11381         kfree(net->dev_index_head);
11382         xa_destroy(&net->dev_by_index);
11383         if (net != &init_net)
11384                 WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11385 }
11386
11387 static struct pernet_operations __net_initdata netdev_net_ops = {
11388         .init = netdev_init,
11389         .exit = netdev_exit,
11390 };
11391
11392 static void __net_exit default_device_exit_net(struct net *net)
11393 {
11394         struct net_device *dev, *aux;
11395         /*
11396          * Push all migratable network devices back to the
11397          * initial network namespace
11398          */
11399         ASSERT_RTNL();
11400         for_each_netdev_safe(net, dev, aux) {
11401                 int err;
11402                 char fb_name[IFNAMSIZ];
11403
11404                 /* Ignore unmoveable devices (i.e. loopback) */
11405                 if (dev->features & NETIF_F_NETNS_LOCAL)
11406                         continue;
11407
11408                 /* Leave virtual devices for the generic cleanup */
11409                 if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11410                         continue;
11411
11412                 /* Push remaining network devices to init_net */
11413                 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11414                 if (netdev_name_in_use(&init_net, fb_name))
11415                         snprintf(fb_name, IFNAMSIZ, "dev%%d");
11416                 err = dev_change_net_namespace(dev, &init_net, fb_name);
11417                 if (err) {
11418                         pr_emerg("%s: failed to move %s to init_net: %d\n",
11419                                  __func__, dev->name, err);
11420                         BUG();
11421                 }
11422         }
11423 }
11424
11425 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11426 {
11427         /* At exit all network devices most be removed from a network
11428          * namespace.  Do this in the reverse order of registration.
11429          * Do this across as many network namespaces as possible to
11430          * improve batching efficiency.
11431          */
11432         struct net_device *dev;
11433         struct net *net;
11434         LIST_HEAD(dev_kill_list);
11435
11436         rtnl_lock();
11437         list_for_each_entry(net, net_list, exit_list) {
11438                 default_device_exit_net(net);
11439                 cond_resched();
11440         }
11441
11442         list_for_each_entry(net, net_list, exit_list) {
11443                 for_each_netdev_reverse(net, dev) {
11444                         if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11445                                 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11446                         else
11447                                 unregister_netdevice_queue(dev, &dev_kill_list);
11448                 }
11449         }
11450         unregister_netdevice_many(&dev_kill_list);
11451         rtnl_unlock();
11452 }
11453
11454 static struct pernet_operations __net_initdata default_device_ops = {
11455         .exit_batch = default_device_exit_batch,
11456 };
11457
11458 /*
11459  *      Initialize the DEV module. At boot time this walks the device list and
11460  *      unhooks any devices that fail to initialise (normally hardware not
11461  *      present) and leaves us with a valid list of present and active devices.
11462  *
11463  */
11464
11465 /*
11466  *       This is called single threaded during boot, so no need
11467  *       to take the rtnl semaphore.
11468  */
11469 static int __init net_dev_init(void)
11470 {
11471         int i, rc = -ENOMEM;
11472
11473         BUG_ON(!dev_boot_phase);
11474
11475         if (dev_proc_init())
11476                 goto out;
11477
11478         if (netdev_kobject_init())
11479                 goto out;
11480
11481         INIT_LIST_HEAD(&ptype_all);
11482         for (i = 0; i < PTYPE_HASH_SIZE; i++)
11483                 INIT_LIST_HEAD(&ptype_base[i]);
11484
11485         if (register_pernet_subsys(&netdev_net_ops))
11486                 goto out;
11487
11488         /*
11489          *      Initialise the packet receive queues.
11490          */
11491
11492         for_each_possible_cpu(i) {
11493                 struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11494                 struct softnet_data *sd = &per_cpu(softnet_data, i);
11495
11496                 INIT_WORK(flush, flush_backlog);
11497
11498                 skb_queue_head_init(&sd->input_pkt_queue);
11499                 skb_queue_head_init(&sd->process_queue);
11500 #ifdef CONFIG_XFRM_OFFLOAD
11501                 skb_queue_head_init(&sd->xfrm_backlog);
11502 #endif
11503                 INIT_LIST_HEAD(&sd->poll_list);
11504                 sd->output_queue_tailp = &sd->output_queue;
11505 #ifdef CONFIG_RPS
11506                 INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11507                 sd->cpu = i;
11508 #endif
11509                 INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11510                 spin_lock_init(&sd->defer_lock);
11511
11512                 init_gro_hash(&sd->backlog);
11513                 sd->backlog.poll = process_backlog;
11514                 sd->backlog.weight = weight_p;
11515         }
11516
11517         dev_boot_phase = 0;
11518
11519         /* The loopback device is special if any other network devices
11520          * is present in a network namespace the loopback device must
11521          * be present. Since we now dynamically allocate and free the
11522          * loopback device ensure this invariant is maintained by
11523          * keeping the loopback device as the first device on the
11524          * list of network devices.  Ensuring the loopback devices
11525          * is the first device that appears and the last network device
11526          * that disappears.
11527          */
11528         if (register_pernet_device(&loopback_net_ops))
11529                 goto out;
11530
11531         if (register_pernet_device(&default_device_ops))
11532                 goto out;
11533
11534         open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11535         open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11536
11537         rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11538                                        NULL, dev_cpu_dead);
11539         WARN_ON(rc < 0);
11540         rc = 0;
11541 out:
11542         return rc;
11543 }
11544
11545 subsys_initcall(net_dev_init);