net/packet/af_packet.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              PACKET - implements raw packet sockets.
   7  *
   8  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  11  *
  12  * Fixes:
  13  *              Alan Cox        :       verify_area() now used correctly
  14  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
  15  *              Alan Cox        :       tidied skbuff lists.
  16  *              Alan Cox        :       Now uses generic datagram routines I
  17  *                                      added. Also fixed the peek/read crash
  18  *                                      from all old Linux datagram code.
  19  *              Alan Cox        :       Uses the improved datagram code.
  20  *              Alan Cox        :       Added NULL's for socket options.
  21  *              Alan Cox        :       Re-commented the code.
  22  *              Alan Cox        :       Use new kernel side addressing
  23  *              Rob Janssen     :       Correct MTU usage.
  24  *              Dave Platt      :       Counter leaks caused by incorrect
  25  *                                      interrupt locking and some slightly
  26  *                                      dubious gcc output. Can you read
  27  *                                      compiler: it said _VOLATILE_
  28  *      Richard Kooijman        :       Timestamp fixes.
  29  *              Alan Cox        :       New buffers. Use sk->mac.raw.
  30  *              Alan Cox        :       sendmsg/recvmsg support.
  31  *              Alan Cox        :       Protocol setting support
  32  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
  33  *      Cyrus Durgin            :       Fixed kerneld for kmod.
  34  *      Michal Ostrowski        :       Module initialization cleanup.
  35  *         Ulises Alonso        :       Frame number limit removal and
  36  *                                      packet_set_ring memory leak.
  37  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
  38  *                                      The convention is that longer addresses
  39  *                                      will simply extend the hardware address
  40  *                                      byte arrays at the end of sockaddr_ll
  41  *                                      and packet_mreq.
  42  *              Johann Baudy    :       Added TX RING.
  43  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
  44  *                                      layer.
  45  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
  46  *
  47  *
  48  *              This program is free software; you can redistribute it and/or
  49  *              modify it under the terms of the GNU General Public License
  50  *              as published by the Free Software Foundation; either version
  51  *              2 of the License, or (at your option) any later version.
  52  *
  53  */
  54
  55 #include <linux/types.h>
  56 #include <linux/mm.h>
  57 #include <linux/capability.h>
  58 #include <linux/fcntl.h>
  59 #include <linux/socket.h>
  60 #include <linux/in.h>
  61 #include <linux/inet.h>
  62 #include <linux/netdevice.h>
  63 #include <linux/if_packet.h>
  64 #include <linux/wireless.h>
  65 #include <linux/kernel.h>
  66 #include <linux/kmod.h>
  67 #include <linux/slab.h>
  68 #include <linux/vmalloc.h>
  69 #include <net/net_namespace.h>
  70 #include <net/ip.h>
  71 #include <net/protocol.h>
  72 #include <linux/skbuff.h>
  73 #include <net/sock.h>
  74 #include <linux/errno.h>
  75 #include <linux/timer.h>
  76 #include <asm/uaccess.h>
  77 #include <asm/ioctls.h>
  78 #include <asm/page.h>
  79 #include <asm/cacheflush.h>
  80 #include <asm/io.h>
  81 #include <linux/proc_fs.h>
  82 #include <linux/seq_file.h>
  83 #include <linux/poll.h>
  84 #include <linux/module.h>
  85 #include <linux/init.h>
  86 #include <linux/mutex.h>
  87 #include <linux/if_vlan.h>
  88 #include <linux/virtio_net.h>
  89 #include <linux/errqueue.h>
  90 #include <linux/net_tstamp.h>
  91
  92 #ifdef CONFIG_INET
  93 #include <net/inet_common.h>
  94 #endif
  95
  96 /*
  97    Assumptions:
  98    - if device has no dev->hard_header routine, it adds and removes ll header
  99      inside itself. In this case ll header is invisible outside of device,
 100      but higher levels still should reserve dev->hard_header_len.
 101      Some devices are enough clever to reallocate skb, when header
 102      will not fit to reserved space (tunnel), another ones are silly
 103      (PPP).
 104    - packet socket receives packets with pulled ll header,
 105      so that SOCK_RAW should push it back.
 106
 107 On receive:
 108 -----------
 109
 110 Incoming, dev->hard_header!=NULL
 111    mac_header -> ll header
 112    data       -> data
 113
 114 Outgoing, dev->hard_header!=NULL
 115    mac_header -> ll header
 116    data       -> ll header
 117
 118 Incoming, dev->hard_header==NULL
 119    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 120                  header.  PPP makes it, that is wrong, because introduce
 121                  assymetry between rx and tx paths.
 122    data       -> data
 123
 124 Outgoing, dev->hard_header==NULL
 125    mac_header -> data. ll header is still not built!
 126    data       -> data
 127
 128 Resume
 129   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 130
 131
 132 On transmit:
 133 ------------
 134
 135 dev->hard_header != NULL
 136    mac_header -> ll header
 137    data       -> ll header
 138
 139 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 140    mac_header -> data
 141    data       -> data
 142
 143    We should set nh.raw on output to correct posistion,
 144    packet classifier depends on it.
 145  */
 146
 147 /* Private packet socket structures. */
 148
 149 struct packet_mclist {
 150         struct packet_mclist    *next;
 151         int                     ifindex;
 152         int                     count;
 153         unsigned short          type;
 154         unsigned short          alen;
 155         unsigned char           addr[MAX_ADDR_LEN];
 156 };
 157 /* identical to struct packet_mreq except it has
 158  * a longer address field.
 159  */
 160 struct packet_mreq_max {
 161         int             mr_ifindex;
 162         unsigned short  mr_type;
 163         unsigned short  mr_alen;
 164         unsigned char   mr_address[MAX_ADDR_LEN];
 165 };
 166
 167 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 168                 int closing, int tx_ring);
 169
 170
 171 #define V3_ALIGNMENT    (8)
 172
 173 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 174
 175 #define BLK_PLUS_PRIV(sz_of_priv) \
 176         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 177
 178 /* kbdq - kernel block descriptor queue */
 179 struct tpacket_kbdq_core {
 180         struct pgv      *pkbdq;
 181         unsigned int    feature_req_word;
 182         unsigned int    hdrlen;
 183         unsigned char   reset_pending_on_curr_blk;
 184         unsigned char   delete_blk_timer;
 185         unsigned short  kactive_blk_num;
 186         unsigned short  blk_sizeof_priv;
 187
 188         /* last_kactive_blk_num:
 189          * trick to see if user-space has caught up
 190          * in order to avoid refreshing timer when every single pkt arrives.
 191          */
 192         unsigned short  last_kactive_blk_num;
 193
 194         char            *pkblk_start;
 195         char            *pkblk_end;
 196         int             kblk_size;
 197         unsigned int    knum_blocks;
 198         uint64_t        knxt_seq_num;
 199         char            *prev;
 200         char            *nxt_offset;
 201         struct sk_buff  *skb;
 202
 203         atomic_t        blk_fill_in_prog;
 204
 205         /* Default is set to 8ms */
 206 #define DEFAULT_PRB_RETIRE_TOV  (8)
 207
 208         unsigned short  retire_blk_tov;
 209         unsigned short  version;
 210         unsigned long   tov_in_jiffies;
 211
 212         /* timer to retire an outstanding block */
 213         struct timer_list retire_blk_timer;
 214 };
 215
 216 #define PGV_FROM_VMALLOC 1
 217 struct pgv {
 218         char *buffer;
 219 };
 220
 221 struct packet_ring_buffer {
 222         struct pgv              *pg_vec;
 223         unsigned int            head;
 224         unsigned int            frames_per_block;
 225         unsigned int            frame_size;
 226         unsigned int            frame_max;
 227
 228         unsigned int            pg_vec_order;
 229         unsigned int            pg_vec_pages;
 230         unsigned int            pg_vec_len;
 231
 232         struct tpacket_kbdq_core        prb_bdqc;
 233         atomic_t                pending;
 234 };
 235
 236 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 237 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 238 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 239 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 240 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 241 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 242 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 243
 244 struct packet_sock;
 245 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 246
 247 static void *packet_previous_frame(struct packet_sock *po,
 248                 struct packet_ring_buffer *rb,
 249                 int status);
 250 static void packet_increment_head(struct packet_ring_buffer *buff);
 251 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 252                         struct tpacket_block_desc *);
 253 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 254                         struct packet_sock *);
 255 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 256                 struct packet_sock *, unsigned int status);
 257 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 258 static void prb_open_block(struct tpacket_kbdq_core *,
 259                 struct tpacket_block_desc *);
 260 static void prb_retire_rx_blk_timer_expired(unsigned long);
 261 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 262 static void prb_init_blk_timer(struct packet_sock *,
 263                 struct tpacket_kbdq_core *,
 264                 void (*func) (unsigned long));
 265 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 266 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 267                 struct tpacket3_hdr *);
 268 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 269                 struct tpacket3_hdr *);
 270 static void packet_flush_mclist(struct sock *sk);
 271
 272 struct packet_fanout;
 273 struct packet_sock {
 274         /* struct sock has to be the first member of packet_sock */
 275         struct sock             sk;
 276         struct packet_fanout    *fanout;
 277         struct tpacket_stats    stats;
 278         union  tpacket_stats_u  stats_u;
 279         struct packet_ring_buffer       rx_ring;
 280         struct packet_ring_buffer       tx_ring;
 281         int                     copy_thresh;
 282         spinlock_t              bind_lock;
 283         struct mutex            pg_vec_lock;
 284         unsigned int            running:1,      /* prot_hook is attached*/
 285                                 auxdata:1,
 286                                 origdev:1,
 287                                 has_vnet_hdr:1;
 288         int                     ifindex;        /* bound device         */
 289         __be16                  num;
 290         struct packet_mclist    *mclist;
 291         atomic_t                mapped;
 292         enum tpacket_versions   tp_version;
 293         unsigned int            tp_hdrlen;
 294         unsigned int            tp_reserve;
 295         unsigned int            tp_loss:1;
 296         unsigned int            tp_tstamp;
 297         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 298 };
 299
 300 #define PACKET_FANOUT_MAX       256
 301
 302 struct packet_fanout {
 303 #ifdef CONFIG_NET_NS
 304         struct net              *net;
 305 #endif
 306         unsigned int            num_members;
 307         u16                     id;
 308         u8                      type;
 309         u8                      defrag;
 310         atomic_t                rr_cur;
 311         struct list_head        list;
 312         struct sock             *arr[PACKET_FANOUT_MAX];
 313         spinlock_t              lock;
 314         atomic_t                sk_ref;
 315         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 316 };
 317
 318 struct packet_skb_cb {
 319         unsigned int origlen;
 320         union {
 321                 struct sockaddr_pkt pkt;
 322                 struct sockaddr_ll ll;
 323         } sa;
 324 };
 325
 326 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 327
 328 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 329 #define GET_PBLOCK_DESC(x, bid) \
 330         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 331 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 332         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 333 #define GET_NEXT_PRB_BLK_NUM(x) \
 334         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 335         ((x)->kactive_blk_num+1) : 0)
 336
 337 static struct packet_sock *pkt_sk(struct sock *sk)
 338 {
 339         return (struct packet_sock *)sk;
 340 }
 341
 342 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 343 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 344
 345 /* register_prot_hook must be invoked with the po->bind_lock held,
 346  * or from a context in which asynchronous accesses to the packet
 347  * socket is not possible (packet_create()).
 348  */
 349 static void register_prot_hook(struct sock *sk)
 350 {
 351         struct packet_sock *po = pkt_sk(sk);
 352         if (!po->running) {
 353                 if (po->fanout)
 354                         __fanout_link(sk, po);
 355                 else
 356                         dev_add_pack(&po->prot_hook);
 357                 sock_hold(sk);
 358                 po->running = 1;
 359         }
 360 }
 361
 362 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 363  * held.   If the sync parameter is true, we will temporarily drop
 364  * the po->bind_lock and do a synchronize_net to make sure no
 365  * asynchronous packet processing paths still refer to the elements
 366  * of po->prot_hook.  If the sync parameter is false, it is the
 367  * callers responsibility to take care of this.
 368  */
 369 static void __unregister_prot_hook(struct sock *sk, bool sync)
 370 {
 371         struct packet_sock *po = pkt_sk(sk);
 372
 373         po->running = 0;
 374         if (po->fanout)
 375                 __fanout_unlink(sk, po);
 376         else
 377                 __dev_remove_pack(&po->prot_hook);
 378         __sock_put(sk);
 379
 380         if (sync) {
 381                 spin_unlock(&po->bind_lock);
 382                 synchronize_net();
 383                 spin_lock(&po->bind_lock);
 384         }
 385 }
 386
 387 static void unregister_prot_hook(struct sock *sk, bool sync)
 388 {
 389         struct packet_sock *po = pkt_sk(sk);
 390
 391         if (po->running)
 392                 __unregister_prot_hook(sk, sync);
 393 }
 394
 395 static inline __pure struct page *pgv_to_page(void *addr)
 396 {
 397         if (is_vmalloc_addr(addr))
 398                 return vmalloc_to_page(addr);
 399         return virt_to_page(addr);
 400 }
 401
 402 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 403 {
 404         union {
 405                 struct tpacket_hdr *h1;
 406                 struct tpacket2_hdr *h2;
 407                 void *raw;
 408         } h;
 409
 410         h.raw = frame;
 411         switch (po->tp_version) {
 412         case TPACKET_V1:
 413                 h.h1->tp_status = status;
 414                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 415                 break;
 416         case TPACKET_V2:
 417                 h.h2->tp_status = status;
 418                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 419                 break;
 420         case TPACKET_V3:
 421         default:
 422                 WARN(1, "TPACKET version not supported.\n");
 423                 BUG();
 424         }
 425
 426         smp_wmb();
 427 }
 428
 429 static int __packet_get_status(struct packet_sock *po, void *frame)
 430 {
 431         union {
 432                 struct tpacket_hdr *h1;
 433                 struct tpacket2_hdr *h2;
 434                 void *raw;
 435         } h;
 436
 437         smp_rmb();
 438
 439         h.raw = frame;
 440         switch (po->tp_version) {
 441         case TPACKET_V1:
 442                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 443                 return h.h1->tp_status;
 444         case TPACKET_V2:
 445                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 446                 return h.h2->tp_status;
 447         case TPACKET_V3:
 448         default:
 449                 WARN(1, "TPACKET version not supported.\n");
 450                 BUG();
 451                 return 0;
 452         }
 453 }
 454
 455 static void *packet_lookup_frame(struct packet_sock *po,
 456                 struct packet_ring_buffer *rb,
 457                 unsigned int position,
 458                 int status)
 459 {
 460         unsigned int pg_vec_pos, frame_offset;
 461         union {
 462                 struct tpacket_hdr *h1;
 463                 struct tpacket2_hdr *h2;
 464                 void *raw;
 465         } h;
 466
 467         pg_vec_pos = position / rb->frames_per_block;
 468         frame_offset = position % rb->frames_per_block;
 469
 470         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 471                 (frame_offset * rb->frame_size);
 472
 473         if (status != __packet_get_status(po, h.raw))
 474                 return NULL;
 475
 476         return h.raw;
 477 }
 478
 479 static void *packet_current_frame(struct packet_sock *po,
 480                 struct packet_ring_buffer *rb,
 481                 int status)
 482 {
 483         return packet_lookup_frame(po, rb, rb->head, status);
 484 }
 485
 486 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 487 {
 488         del_timer_sync(&pkc->retire_blk_timer);
 489 }
 490
 491 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 492                 int tx_ring,
 493                 struct sk_buff_head *rb_queue)
 494 {
 495         struct tpacket_kbdq_core *pkc;
 496
 497         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 498
 499         spin_lock(&rb_queue->lock);
 500         pkc->delete_blk_timer = 1;
 501         spin_unlock(&rb_queue->lock);
 502
 503         prb_del_retire_blk_timer(pkc);
 504 }
 505
 506 static void prb_init_blk_timer(struct packet_sock *po,
 507                 struct tpacket_kbdq_core *pkc,
 508                 void (*func) (unsigned long))
 509 {
 510         init_timer(&pkc->retire_blk_timer);
 511         pkc->retire_blk_timer.data = (long)po;
 512         pkc->retire_blk_timer.function = func;
 513         pkc->retire_blk_timer.expires = jiffies;
 514 }
 515
 516 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 517 {
 518         struct tpacket_kbdq_core *pkc;
 519
 520         if (tx_ring)
 521                 BUG();
 522
 523         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 524         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 525 }
 526
 527 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 528                                 int blk_size_in_bytes)
 529 {
 530         struct net_device *dev;
 531         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 532         struct ethtool_cmd ecmd;
 533         int err;
 534         u32 speed;
 535
 536         rtnl_lock();
 537         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 538         if (unlikely(!dev)) {
 539                 rtnl_unlock();
 540                 return DEFAULT_PRB_RETIRE_TOV;
 541         }
 542         err = __ethtool_get_settings(dev, &ecmd);
 543         speed = ethtool_cmd_speed(&ecmd);
 544         rtnl_unlock();
 545         if (!err) {
 546                 /*
 547                  * If the link speed is so slow you don't really
 548                  * need to worry about perf anyways
 549                  */
 550                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 551                         return DEFAULT_PRB_RETIRE_TOV;
 552                 } else {
 553                         msec = 1;
 554                         div = speed / 1000;
 555                 }
 556         }
 557
 558         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 559
 560         if (div)
 561                 mbits /= div;
 562
 563         tmo = mbits * msec;
 564
 565         if (div)
 566                 return tmo+1;
 567         return tmo;
 568 }
 569
 570 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 571                         union tpacket_req_u *req_u)
 572 {
 573         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 574 }
 575
 576 static void init_prb_bdqc(struct packet_sock *po,
 577                         struct packet_ring_buffer *rb,
 578                         struct pgv *pg_vec,
 579                         union tpacket_req_u *req_u, int tx_ring)
 580 {
 581         struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
 582         struct tpacket_block_desc *pbd;
 583
 584         memset(p1, 0x0, sizeof(*p1));
 585
 586         p1->knxt_seq_num = 1;
 587         p1->pkbdq = pg_vec;
 588         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 589         p1->pkblk_start = pg_vec[0].buffer;
 590         p1->kblk_size = req_u->req3.tp_block_size;
 591         p1->knum_blocks = req_u->req3.tp_block_nr;
 592         p1->hdrlen = po->tp_hdrlen;
 593         p1->version = po->tp_version;
 594         p1->last_kactive_blk_num = 0;
 595         po->stats_u.stats3.tp_freeze_q_cnt = 0;
 596         if (req_u->req3.tp_retire_blk_tov)
 597                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 598         else
 599                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 600                                                 req_u->req3.tp_block_size);
 601         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 602         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 603
 604         prb_init_ft_ops(p1, req_u);
 605         prb_setup_retire_blk_timer(po, tx_ring);
 606         prb_open_block(p1, pbd);
 607 }
 608
 609 /*  Do NOT update the last_blk_num first.
 610  *  Assumes sk_buff_head lock is held.
 611  */
 612 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 613 {
 614         mod_timer(&pkc->retire_blk_timer,
 615                         jiffies + pkc->tov_in_jiffies);
 616         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 617 }
 618
 619 /*
 620  * Timer logic:
 621  * 1) We refresh the timer only when we open a block.
 622  *    By doing this we don't waste cycles refreshing the timer
 623  *        on packet-by-packet basis.
 624  *
 625  * With a 1MB block-size, on a 1Gbps line, it will take
 626  * i) ~8 ms to fill a block + ii) memcpy etc.
 627  * In this cut we are not accounting for the memcpy time.
 628  *
 629  * So, if the user sets the 'tmo' to 10ms then the timer
 630  * will never fire while the block is still getting filled
 631  * (which is what we want). However, the user could choose
 632  * to close a block early and that's fine.
 633  *
 634  * But when the timer does fire, we check whether or not to refresh it.
 635  * Since the tmo granularity is in msecs, it is not too expensive
 636  * to refresh the timer, lets say every '8' msecs.
 637  * Either the user can set the 'tmo' or we can derive it based on
 638  * a) line-speed and b) block-size.
 639  * prb_calc_retire_blk_tmo() calculates the tmo.
 640  *
 641  */
 642 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 643 {
 644         struct packet_sock *po = (struct packet_sock *)data;
 645         struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
 646         unsigned int frozen;
 647         struct tpacket_block_desc *pbd;
 648
 649         spin_lock(&po->sk.sk_receive_queue.lock);
 650
 651         frozen = prb_queue_frozen(pkc);
 652         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 653
 654         if (unlikely(pkc->delete_blk_timer))
 655                 goto out;
 656
 657         /* We only need to plug the race when the block is partially filled.
 658          * tpacket_rcv:
 659          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 660          *              copy_bits() is in progress ...
 661          *              timer fires on other cpu:
 662          *              we can't retire the current block because copy_bits
 663          *              is in progress.
 664          *
 665          */
 666         if (BLOCK_NUM_PKTS(pbd)) {
 667                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 668                         /* Waiting for skb_copy_bits to finish... */
 669                         cpu_relax();
 670                 }
 671         }
 672
 673         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 674                 if (!frozen) {
 675                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 676                         if (!prb_dispatch_next_block(pkc, po))
 677                                 goto refresh_timer;
 678                         else
 679                                 goto out;
 680                 } else {
 681                         /* Case 1. Queue was frozen because user-space was
 682                          *         lagging behind.
 683                          */
 684                         if (prb_curr_blk_in_use(pkc, pbd)) {
 685                                 /*
 686                                  * Ok, user-space is still behind.
 687                                  * So just refresh the timer.
 688                                  */
 689                                 goto refresh_timer;
 690                         } else {
 691                                /* Case 2. queue was frozen,user-space caught up,
 692                                 * now the link went idle && the timer fired.
 693                                 * We don't have a block to close.So we open this
 694                                 * block and restart the timer.
 695                                 * opening a block thaws the queue,restarts timer
 696                                 * Thawing/timer-refresh is a side effect.
 697                                 */
 698                                 prb_open_block(pkc, pbd);
 699                                 goto out;
 700                         }
 701                 }
 702         }
 703
 704 refresh_timer:
 705         _prb_refresh_rx_retire_blk_timer(pkc);
 706
 707 out:
 708         spin_unlock(&po->sk.sk_receive_queue.lock);
 709 }
 710
 711 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 712                 struct tpacket_block_desc *pbd1, __u32 status)
 713 {
 714         /* Flush everything minus the block header */
 715
 716 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 717         u8 *start, *end;
 718
 719         start = (u8 *)pbd1;
 720
 721         /* Skip the block header(we know header WILL fit in 4K) */
 722         start += PAGE_SIZE;
 723
 724         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 725         for (; start < end; start += PAGE_SIZE)
 726                 flush_dcache_page(pgv_to_page(start));
 727
 728         smp_wmb();
 729 #endif
 730
 731         /* Now update the block status. */
 732
 733         BLOCK_STATUS(pbd1) = status;
 734
 735         /* Flush the block header */
 736
 737 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 738         start = (u8 *)pbd1;
 739         flush_dcache_page(pgv_to_page(start));
 740
 741         smp_wmb();
 742 #endif
 743 }
 744
 745 /*
 746  * Side effect:
 747  *
 748  * 1) flush the block
 749  * 2) Increment active_blk_num
 750  *
 751  * Note:We DONT refresh the timer on purpose.
 752  *      Because almost always the next block will be opened.
 753  */
 754 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 755                 struct tpacket_block_desc *pbd1,
 756                 struct packet_sock *po, unsigned int stat)
 757 {
 758         __u32 status = TP_STATUS_USER | stat;
 759
 760         struct tpacket3_hdr *last_pkt;
 761         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 762
 763         if (po->stats.tp_drops)
 764                 status |= TP_STATUS_LOSING;
 765
 766         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 767         last_pkt->tp_next_offset = 0;
 768
 769         /* Get the ts of the last pkt */
 770         if (BLOCK_NUM_PKTS(pbd1)) {
 771                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 772                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 773         } else {
 774                 /* Ok, we tmo'd - so get the current time */
 775                 struct timespec ts;
 776                 getnstimeofday(&ts);
 777                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 778                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 779         }
 780
 781         smp_wmb();
 782
 783         /* Flush the block */
 784         prb_flush_block(pkc1, pbd1, status);
 785
 786         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 787 }
 788
 789 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 790 {
 791         pkc->reset_pending_on_curr_blk = 0;
 792 }
 793
 794 /*
 795  * Side effect of opening a block:
 796  *
 797  * 1) prb_queue is thawed.
 798  * 2) retire_blk_timer is refreshed.
 799  *
 800  */
 801 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 802         struct tpacket_block_desc *pbd1)
 803 {
 804         struct timespec ts;
 805         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 806
 807         smp_rmb();
 808
 809         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
 810
 811                 /* We could have just memset this but we will lose the
 812                  * flexibility of making the priv area sticky
 813                  */
 814                 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 815                 BLOCK_NUM_PKTS(pbd1) = 0;
 816                 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 817                 getnstimeofday(&ts);
 818                 h1->ts_first_pkt.ts_sec = ts.tv_sec;
 819                 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 820                 pkc1->pkblk_start = (char *)pbd1;
 821                 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 822                 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 823                 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 824                 pbd1->version = pkc1->version;
 825                 pkc1->prev = pkc1->nxt_offset;
 826                 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 827                 prb_thaw_queue(pkc1);
 828                 _prb_refresh_rx_retire_blk_timer(pkc1);
 829
 830                 smp_wmb();
 831
 832                 return;
 833         }
 834
 835         WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
 836                 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
 837         dump_stack();
 838         BUG();
 839 }
 840
 841 /*
 842  * Queue freeze logic:
 843  * 1) Assume tp_block_nr = 8 blocks.
 844  * 2) At time 't0', user opens Rx ring.
 845  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 846  * 4) user-space is either sleeping or processing block '0'.
 847  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 848  *    it will close block-7,loop around and try to fill block '0'.
 849  *    call-flow:
 850  *    __packet_lookup_frame_in_block
 851  *      prb_retire_current_block()
 852  *      prb_dispatch_next_block()
 853  *        |->(BLOCK_STATUS == USER) evaluates to true
 854  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 855  * 6) Now there are two cases:
 856  *    6.1) Link goes idle right after the queue is frozen.
 857  *         But remember, the last open_block() refreshed the timer.
 858  *         When this timer expires,it will refresh itself so that we can
 859  *         re-open block-0 in near future.
 860  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 861  *         case and __packet_lookup_frame_in_block will check if block-0
 862  *         is free and can now be re-used.
 863  */
 864 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 865                                   struct packet_sock *po)
 866 {
 867         pkc->reset_pending_on_curr_blk = 1;
 868         po->stats_u.stats3.tp_freeze_q_cnt++;
 869 }
 870
 871 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 872
 873 /*
 874  * If the next block is free then we will dispatch it
 875  * and return a good offset.
 876  * Else, we will freeze the queue.
 877  * So, caller must check the return value.
 878  */
 879 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 880                 struct packet_sock *po)
 881 {
 882         struct tpacket_block_desc *pbd;
 883
 884         smp_rmb();
 885
 886         /* 1. Get current block num */
 887         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 888
 889         /* 2. If this block is currently in_use then freeze the queue */
 890         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 891                 prb_freeze_queue(pkc, po);
 892                 return NULL;
 893         }
 894
 895         /*
 896          * 3.
 897          * open this block and return the offset where the first packet
 898          * needs to get stored.
 899          */
 900         prb_open_block(pkc, pbd);
 901         return (void *)pkc->nxt_offset;
 902 }
 903
 904 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 905                 struct packet_sock *po, unsigned int status)
 906 {
 907         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 908
 909         /* retire/close the current block */
 910         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 911                 /*
 912                  * Plug the case where copy_bits() is in progress on
 913                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 914                  * have space to copy the pkt in the current block and
 915                  * called prb_retire_current_block()
 916                  *
 917                  * We don't need to worry about the TMO case because
 918                  * the timer-handler already handled this case.
 919                  */
 920                 if (!(status & TP_STATUS_BLK_TMO)) {
 921                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 922                                 /* Waiting for skb_copy_bits to finish... */
 923                                 cpu_relax();
 924                         }
 925                 }
 926                 prb_close_block(pkc, pbd, po, status);
 927                 return;
 928         }
 929
 930         WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
 931         dump_stack();
 932         BUG();
 933 }
 934
 935 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 936                                       struct tpacket_block_desc *pbd)
 937 {
 938         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 939 }
 940
 941 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 942 {
 943         return pkc->reset_pending_on_curr_blk;
 944 }
 945
 946 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 947 {
 948         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 949         atomic_dec(&pkc->blk_fill_in_prog);
 950 }
 951
 952 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 953                         struct tpacket3_hdr *ppd)
 954 {
 955         ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
 956 }
 957
 958 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 959                         struct tpacket3_hdr *ppd)
 960 {
 961         ppd->hv1.tp_rxhash = 0;
 962 }
 963
 964 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 965                         struct tpacket3_hdr *ppd)
 966 {
 967         if (vlan_tx_tag_present(pkc->skb)) {
 968                 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
 969                 ppd->tp_status = TP_STATUS_VLAN_VALID;
 970         } else {
 971                 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0;
 972         }
 973 }
 974
 975 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
 976                         struct tpacket3_hdr *ppd)
 977 {
 978         prb_fill_vlan_info(pkc, ppd);
 979
 980         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
 981                 prb_fill_rxhash(pkc, ppd);
 982         else
 983                 prb_clear_rxhash(pkc, ppd);
 984 }
 985
 986 static void prb_fill_curr_block(char *curr,
 987                                 struct tpacket_kbdq_core *pkc,
 988                                 struct tpacket_block_desc *pbd,
 989                                 unsigned int len)
 990 {
 991         struct tpacket3_hdr *ppd;
 992
 993         ppd  = (struct tpacket3_hdr *)curr;
 994         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
 995         pkc->prev = curr;
 996         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
 997         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
 998         BLOCK_NUM_PKTS(pbd) += 1;
 999         atomic_inc(&pkc->blk_fill_in_prog);
1000         prb_run_all_ft_ops(pkc, ppd);
1001 }
1002
1003 /* Assumes caller has the sk->rx_queue.lock */
1004 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1005                                             struct sk_buff *skb,
1006                                                 int status,
1007                                             unsigned int len
1008                                             )
1009 {
1010         struct tpacket_kbdq_core *pkc;
1011         struct tpacket_block_desc *pbd;
1012         char *curr, *end;
1013
1014         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1015         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1016
1017         /* Queue is frozen when user space is lagging behind */
1018         if (prb_queue_frozen(pkc)) {
1019                 /*
1020                  * Check if that last block which caused the queue to freeze,
1021                  * is still in_use by user-space.
1022                  */
1023                 if (prb_curr_blk_in_use(pkc, pbd)) {
1024                         /* Can't record this packet */
1025                         return NULL;
1026                 } else {
1027                         /*
1028                          * Ok, the block was released by user-space.
1029                          * Now let's open that block.
1030                          * opening a block also thaws the queue.
1031                          * Thawing is a side effect.
1032                          */
1033                         prb_open_block(pkc, pbd);
1034                 }
1035         }
1036
1037         smp_mb();
1038         curr = pkc->nxt_offset;
1039         pkc->skb = skb;
1040         end = (char *)pbd + pkc->kblk_size;
1041
1042         /* first try the current block */
1043         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1044                 prb_fill_curr_block(curr, pkc, pbd, len);
1045                 return (void *)curr;
1046         }
1047
1048         /* Ok, close the current block */
1049         prb_retire_current_block(pkc, po, 0);
1050
1051         /* Now, try to dispatch the next block */
1052         curr = (char *)prb_dispatch_next_block(pkc, po);
1053         if (curr) {
1054                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1055                 prb_fill_curr_block(curr, pkc, pbd, len);
1056                 return (void *)curr;
1057         }
1058
1059         /*
1060          * No free blocks are available.user_space hasn't caught up yet.
1061          * Queue was just frozen and now this packet will get dropped.
1062          */
1063         return NULL;
1064 }
1065
1066 static void *packet_current_rx_frame(struct packet_sock *po,
1067                                             struct sk_buff *skb,
1068                                             int status, unsigned int len)
1069 {
1070         char *curr = NULL;
1071         switch (po->tp_version) {
1072         case TPACKET_V1:
1073         case TPACKET_V2:
1074                 curr = packet_lookup_frame(po, &po->rx_ring,
1075                                         po->rx_ring.head, status);
1076                 return curr;
1077         case TPACKET_V3:
1078                 return __packet_lookup_frame_in_block(po, skb, status, len);
1079         default:
1080                 WARN(1, "TPACKET version not supported\n");
1081                 BUG();
1082                 return NULL;
1083         }
1084 }
1085
1086 static void *prb_lookup_block(struct packet_sock *po,
1087                                      struct packet_ring_buffer *rb,
1088                                      unsigned int previous,
1089                                      int status)
1090 {
1091         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1092         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
1093
1094         if (status != BLOCK_STATUS(pbd))
1095                 return NULL;
1096         return pbd;
1097 }
1098
1099 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1100 {
1101         unsigned int prev;
1102         if (rb->prb_bdqc.kactive_blk_num)
1103                 prev = rb->prb_bdqc.kactive_blk_num-1;
1104         else
1105                 prev = rb->prb_bdqc.knum_blocks-1;
1106         return prev;
1107 }
1108
1109 /* Assumes caller has held the rx_queue.lock */
1110 static void *__prb_previous_block(struct packet_sock *po,
1111                                          struct packet_ring_buffer *rb,
1112                                          int status)
1113 {
1114         unsigned int previous = prb_previous_blk_num(rb);
1115         return prb_lookup_block(po, rb, previous, status);
1116 }
1117
1118 static void *packet_previous_rx_frame(struct packet_sock *po,
1119                                              struct packet_ring_buffer *rb,
1120                                              int status)
1121 {
1122         if (po->tp_version <= TPACKET_V2)
1123                 return packet_previous_frame(po, rb, status);
1124
1125         return __prb_previous_block(po, rb, status);
1126 }
1127
1128 static void packet_increment_rx_head(struct packet_sock *po,
1129                                             struct packet_ring_buffer *rb)
1130 {
1131         switch (po->tp_version) {
1132         case TPACKET_V1:
1133         case TPACKET_V2:
1134                 return packet_increment_head(rb);
1135         case TPACKET_V3:
1136         default:
1137                 WARN(1, "TPACKET version not supported.\n");
1138                 BUG();
1139                 return;
1140         }
1141 }
1142
1143 static void *packet_previous_frame(struct packet_sock *po,
1144                 struct packet_ring_buffer *rb,
1145                 int status)
1146 {
1147         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1148         return packet_lookup_frame(po, rb, previous, status);
1149 }
1150
1151 static void packet_increment_head(struct packet_ring_buffer *buff)
1152 {
1153         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1154 }
1155
1156 static void packet_sock_destruct(struct sock *sk)
1157 {
1158         skb_queue_purge(&sk->sk_error_queue);
1159
1160         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1161         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1162
1163         if (!sock_flag(sk, SOCK_DEAD)) {
1164                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1165                 return;
1166         }
1167
1168         sk_refcnt_debug_dec(sk);
1169 }
1170
1171 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1172 {
1173         int x = atomic_read(&f->rr_cur) + 1;
1174
1175         if (x >= num)
1176                 x = 0;
1177
1178         return x;
1179 }
1180
1181 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1182 {
1183         u32 idx, hash = skb->rxhash;
1184
1185         idx = ((u64)hash * num) >> 32;
1186
1187         return f->arr[idx];
1188 }
1189
1190 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1191 {
1192         int cur, old;
1193
1194         cur = atomic_read(&f->rr_cur);
1195         while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1196                                      fanout_rr_next(f, num))) != cur)
1197                 cur = old;
1198         return f->arr[cur];
1199 }
1200
1201 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1202 {
1203         unsigned int cpu = smp_processor_id();
1204
1205         return f->arr[cpu % num];
1206 }
1207
1208 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1209                              struct packet_type *pt, struct net_device *orig_dev)
1210 {
1211         struct packet_fanout *f = pt->af_packet_priv;
1212         unsigned int num = f->num_members;
1213         struct packet_sock *po;
1214         struct sock *sk;
1215
1216         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1217             !num) {
1218                 kfree_skb(skb);
1219                 return 0;
1220         }
1221
1222         switch (f->type) {
1223         case PACKET_FANOUT_HASH:
1224         default:
1225                 if (f->defrag) {
1226                         skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1227                         if (!skb)
1228                                 return 0;
1229                 }
1230                 skb_get_rxhash(skb);
1231                 sk = fanout_demux_hash(f, skb, num);
1232                 break;
1233         case PACKET_FANOUT_LB:
1234                 sk = fanout_demux_lb(f, skb, num);
1235                 break;
1236         case PACKET_FANOUT_CPU:
1237                 sk = fanout_demux_cpu(f, skb, num);
1238                 break;
1239         }
1240
1241         po = pkt_sk(sk);
1242
1243         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1244 }
1245
1246 static DEFINE_MUTEX(fanout_mutex);
1247 static LIST_HEAD(fanout_list);
1248
1249 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1250 {
1251         struct packet_fanout *f = po->fanout;
1252
1253         spin_lock(&f->lock);
1254         f->arr[f->num_members] = sk;
1255         smp_wmb();
1256         f->num_members++;
1257         spin_unlock(&f->lock);
1258 }
1259
1260 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1261 {
1262         struct packet_fanout *f = po->fanout;
1263         int i;
1264
1265         spin_lock(&f->lock);
1266         for (i = 0; i < f->num_members; i++) {
1267                 if (f->arr[i] == sk)
1268                         break;
1269         }
1270         BUG_ON(i >= f->num_members);
1271         f->arr[i] = f->arr[f->num_members - 1];
1272         f->num_members--;
1273         spin_unlock(&f->lock);
1274 }
1275
1276 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1277 {
1278         struct packet_sock *po = pkt_sk(sk);
1279         struct packet_fanout *f, *match;
1280         u8 type = type_flags & 0xff;
1281         u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1282         int err;
1283
1284         switch (type) {
1285         case PACKET_FANOUT_HASH:
1286         case PACKET_FANOUT_LB:
1287         case PACKET_FANOUT_CPU:
1288                 break;
1289         default:
1290                 return -EINVAL;
1291         }
1292
1293         if (!po->running)
1294                 return -EINVAL;
1295
1296         if (po->fanout)
1297                 return -EALREADY;
1298
1299         mutex_lock(&fanout_mutex);
1300         match = NULL;
1301         list_for_each_entry(f, &fanout_list, list) {
1302                 if (f->id == id &&
1303                     read_pnet(&f->net) == sock_net(sk)) {
1304                         match = f;
1305                         break;
1306                 }
1307         }
1308         err = -EINVAL;
1309         if (match && match->defrag != defrag)
1310                 goto out;
1311         if (!match) {
1312                 err = -ENOMEM;
1313                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1314                 if (!match)
1315                         goto out;
1316                 write_pnet(&match->net, sock_net(sk));
1317                 match->id = id;
1318                 match->type = type;
1319                 match->defrag = defrag;
1320                 atomic_set(&match->rr_cur, 0);
1321                 INIT_LIST_HEAD(&match->list);
1322                 spin_lock_init(&match->lock);
1323                 atomic_set(&match->sk_ref, 0);
1324                 match->prot_hook.type = po->prot_hook.type;
1325                 match->prot_hook.dev = po->prot_hook.dev;
1326                 match->prot_hook.func = packet_rcv_fanout;
1327                 match->prot_hook.af_packet_priv = match;
1328                 dev_add_pack(&match->prot_hook);
1329                 list_add(&match->list, &fanout_list);
1330         }
1331         err = -EINVAL;
1332         if (match->type == type &&
1333             match->prot_hook.type == po->prot_hook.type &&
1334             match->prot_hook.dev == po->prot_hook.dev) {
1335                 err = -ENOSPC;
1336                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1337                         __dev_remove_pack(&po->prot_hook);
1338                         po->fanout = match;
1339                         atomic_inc(&match->sk_ref);
1340                         __fanout_link(sk, po);
1341                         err = 0;
1342                 }
1343         }
1344 out:
1345         mutex_unlock(&fanout_mutex);
1346         return err;
1347 }
1348
1349 static void fanout_release(struct sock *sk)
1350 {
1351         struct packet_sock *po = pkt_sk(sk);
1352         struct packet_fanout *f;
1353
1354         f = po->fanout;
1355         if (!f)
1356                 return;
1357
1358         po->fanout = NULL;
1359
1360         mutex_lock(&fanout_mutex);
1361         if (atomic_dec_and_test(&f->sk_ref)) {
1362                 list_del(&f->list);
1363                 dev_remove_pack(&f->prot_hook);
1364                 kfree(f);
1365         }
1366         mutex_unlock(&fanout_mutex);
1367 }
1368
1369 static const struct proto_ops packet_ops;
1370
1371 static const struct proto_ops packet_ops_spkt;
1372
1373 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1374                            struct packet_type *pt, struct net_device *orig_dev)
1375 {
1376         struct sock *sk;
1377         struct sockaddr_pkt *spkt;
1378
1379         /*
1380          *      When we registered the protocol we saved the socket in the data
1381          *      field for just this event.
1382          */
1383
1384         sk = pt->af_packet_priv;
1385
1386         /*
1387          *      Yank back the headers [hope the device set this
1388          *      right or kerboom...]
1389          *
1390          *      Incoming packets have ll header pulled,
1391          *      push it back.
1392          *
1393          *      For outgoing ones skb->data == skb_mac_header(skb)
1394          *      so that this procedure is noop.
1395          */
1396
1397         if (skb->pkt_type == PACKET_LOOPBACK)
1398                 goto out;
1399
1400         if (!net_eq(dev_net(dev), sock_net(sk)))
1401                 goto out;
1402
1403         skb = skb_share_check(skb, GFP_ATOMIC);
1404         if (skb == NULL)
1405                 goto oom;
1406
1407         /* drop any routing info */
1408         skb_dst_drop(skb);
1409
1410         /* drop conntrack reference */
1411         nf_reset(skb);
1412
1413         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1414
1415         skb_push(skb, skb->data - skb_mac_header(skb));
1416
1417         /*
1418          *      The SOCK_PACKET socket receives _all_ frames.
1419          */
1420
1421         spkt->spkt_family = dev->type;
1422         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1423         spkt->spkt_protocol = skb->protocol;
1424
1425         /*
1426          *      Charge the memory to the socket. This is done specifically
1427          *      to prevent sockets using all the memory up.
1428          */
1429
1430         if (sock_queue_rcv_skb(sk, skb) == 0)
1431                 return 0;
1432
1433 out:
1434         kfree_skb(skb);
1435 oom:
1436         return 0;
1437 }
1438
1439
1440 /*
1441  *      Output a raw packet to a device layer. This bypasses all the other
1442  *      protocol layers and you must therefore supply it with a complete frame
1443  */
1444
1445 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1446                                struct msghdr *msg, size_t len)
1447 {
1448         struct sock *sk = sock->sk;
1449         struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1450         struct sk_buff *skb = NULL;
1451         struct net_device *dev;
1452         __be16 proto = 0;
1453         int err;
1454         int extra_len = 0;
1455
1456         /*
1457          *      Get and verify the address.
1458          */
1459
1460         if (saddr) {
1461                 if (msg->msg_namelen < sizeof(struct sockaddr))
1462                         return -EINVAL;
1463                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1464                         proto = saddr->spkt_protocol;
1465         } else
1466                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1467
1468         /*
1469          *      Find the device first to size check it
1470          */
1471
1472         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1473 retry:
1474         rcu_read_lock();
1475         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1476         err = -ENODEV;
1477         if (dev == NULL)
1478                 goto out_unlock;
1479
1480         err = -ENETDOWN;
1481         if (!(dev->flags & IFF_UP))
1482                 goto out_unlock;
1483
1484         /*
1485          * You may not queue a frame bigger than the mtu. This is the lowest level
1486          * raw protocol and you must do your own fragmentation at this level.
1487          */
1488
1489         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1490                 if (!netif_supports_nofcs(dev)) {
1491                         err = -EPROTONOSUPPORT;
1492                         goto out_unlock;
1493                 }
1494                 extra_len = 4; /* We're doing our own CRC */
1495         }
1496
1497         err = -EMSGSIZE;
1498         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1499                 goto out_unlock;
1500
1501         if (!skb) {
1502                 size_t reserved = LL_RESERVED_SPACE(dev);
1503                 int tlen = dev->needed_tailroom;
1504                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1505
1506                 rcu_read_unlock();
1507                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1508                 if (skb == NULL)
1509                         return -ENOBUFS;
1510                 /* FIXME: Save some space for broken drivers that write a hard
1511                  * header at transmission time by themselves. PPP is the notable
1512                  * one here. This should really be fixed at the driver level.
1513                  */
1514                 skb_reserve(skb, reserved);
1515                 skb_reset_network_header(skb);
1516
1517                 /* Try to align data part correctly */
1518                 if (hhlen) {
1519                         skb->data -= hhlen;
1520                         skb->tail -= hhlen;
1521                         if (len < hhlen)
1522                                 skb_reset_network_header(skb);
1523                 }
1524                 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1525                 if (err)
1526                         goto out_free;
1527                 goto retry;
1528         }
1529
1530         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1531                 /* Earlier code assumed this would be a VLAN pkt,
1532                  * double-check this now that we have the actual
1533                  * packet in hand.
1534                  */
1535                 struct ethhdr *ehdr;
1536                 skb_reset_mac_header(skb);
1537                 ehdr = eth_hdr(skb);
1538                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1539                         err = -EMSGSIZE;
1540                         goto out_unlock;
1541                 }
1542         }
1543
1544         skb->protocol = proto;
1545         skb->dev = dev;
1546         skb->priority = sk->sk_priority;
1547         skb->mark = sk->sk_mark;
1548         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1549         if (err < 0)
1550                 goto out_unlock;
1551
1552         if (unlikely(extra_len == 4))
1553                 skb->no_fcs = 1;
1554
1555         dev_queue_xmit(skb);
1556         rcu_read_unlock();
1557         return len;
1558
1559 out_unlock:
1560         rcu_read_unlock();
1561 out_free:
1562         kfree_skb(skb);
1563         return err;
1564 }
1565
1566 static unsigned int run_filter(const struct sk_buff *skb,
1567                                       const struct sock *sk,
1568                                       unsigned int res)
1569 {
1570         struct sk_filter *filter;
1571
1572         rcu_read_lock();
1573         filter = rcu_dereference(sk->sk_filter);
1574         if (filter != NULL)
1575                 res = SK_RUN_FILTER(filter, skb);
1576         rcu_read_unlock();
1577
1578         return res;
1579 }
1580
1581 /*
1582  * This function makes lazy skb cloning in hope that most of packets
1583  * are discarded by BPF.
1584  *
1585  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1586  * and skb->cb are mangled. It works because (and until) packets
1587  * falling here are owned by current CPU. Output packets are cloned
1588  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1589  * sequencially, so that if we return skb to original state on exit,
1590  * we will not harm anyone.
1591  */
1592
1593 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1594                       struct packet_type *pt, struct net_device *orig_dev)
1595 {
1596         struct sock *sk;
1597         struct sockaddr_ll *sll;
1598         struct packet_sock *po;
1599         u8 *skb_head = skb->data;
1600         int skb_len = skb->len;
1601         unsigned int snaplen, res;
1602
1603         if (skb->pkt_type == PACKET_LOOPBACK)
1604                 goto drop;
1605
1606         sk = pt->af_packet_priv;
1607         po = pkt_sk(sk);
1608
1609         if (!net_eq(dev_net(dev), sock_net(sk)))
1610                 goto drop;
1611
1612         skb->dev = dev;
1613
1614         if (dev->header_ops) {
1615                 /* The device has an explicit notion of ll header,
1616                  * exported to higher levels.
1617                  *
1618                  * Otherwise, the device hides details of its frame
1619                  * structure, so that corresponding packet head is
1620                  * never delivered to user.
1621                  */
1622                 if (sk->sk_type != SOCK_DGRAM)
1623                         skb_push(skb, skb->data - skb_mac_header(skb));
1624                 else if (skb->pkt_type == PACKET_OUTGOING) {
1625                         /* Special case: outgoing packets have ll header at head */
1626                         skb_pull(skb, skb_network_offset(skb));
1627                 }
1628         }
1629
1630         snaplen = skb->len;
1631
1632         res = run_filter(skb, sk, snaplen);
1633         if (!res)
1634                 goto drop_n_restore;
1635         if (snaplen > res)
1636                 snaplen = res;
1637
1638         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1639                 goto drop_n_acct;
1640
1641         if (skb_shared(skb)) {
1642                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1643                 if (nskb == NULL)
1644                         goto drop_n_acct;
1645
1646                 if (skb_head != skb->data) {
1647                         skb->data = skb_head;
1648                         skb->len = skb_len;
1649                 }
1650                 consume_skb(skb);
1651                 skb = nskb;
1652         }
1653
1654         BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1655                      sizeof(skb->cb));
1656
1657         sll = &PACKET_SKB_CB(skb)->sa.ll;
1658         sll->sll_family = AF_PACKET;
1659         sll->sll_hatype = dev->type;
1660         sll->sll_protocol = skb->protocol;
1661         sll->sll_pkttype = skb->pkt_type;
1662         if (unlikely(po->origdev))
1663                 sll->sll_ifindex = orig_dev->ifindex;
1664         else
1665                 sll->sll_ifindex = dev->ifindex;
1666
1667         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1668
1669         PACKET_SKB_CB(skb)->origlen = skb->len;
1670
1671         if (pskb_trim(skb, snaplen))
1672                 goto drop_n_acct;
1673
1674         skb_set_owner_r(skb, sk);
1675         skb->dev = NULL;
1676         skb_dst_drop(skb);
1677
1678         /* drop conntrack reference */
1679         nf_reset(skb);
1680
1681         spin_lock(&sk->sk_receive_queue.lock);
1682         po->stats.tp_packets++;
1683         skb->dropcount = atomic_read(&sk->sk_drops);
1684         __skb_queue_tail(&sk->sk_receive_queue, skb);
1685         spin_unlock(&sk->sk_receive_queue.lock);
1686         sk->sk_data_ready(sk, skb->len);
1687         return 0;
1688
1689 drop_n_acct:
1690         spin_lock(&sk->sk_receive_queue.lock);
1691         po->stats.tp_drops++;
1692         atomic_inc(&sk->sk_drops);
1693         spin_unlock(&sk->sk_receive_queue.lock);
1694
1695 drop_n_restore:
1696         if (skb_head != skb->data && skb_shared(skb)) {
1697                 skb->data = skb_head;
1698                 skb->len = skb_len;
1699         }
1700 drop:
1701         consume_skb(skb);
1702         return 0;
1703 }
1704
1705 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1706                        struct packet_type *pt, struct net_device *orig_dev)
1707 {
1708         struct sock *sk;
1709         struct packet_sock *po;
1710         struct sockaddr_ll *sll;
1711         union {
1712                 struct tpacket_hdr *h1;
1713                 struct tpacket2_hdr *h2;
1714                 struct tpacket3_hdr *h3;
1715                 void *raw;
1716         } h;
1717         u8 *skb_head = skb->data;
1718         int skb_len = skb->len;
1719         unsigned int snaplen, res;
1720         unsigned long status = TP_STATUS_USER;
1721         unsigned short macoff, netoff, hdrlen;
1722         struct sk_buff *copy_skb = NULL;
1723         struct timeval tv;
1724         struct timespec ts;
1725         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1726
1727         if (skb->pkt_type == PACKET_LOOPBACK)
1728                 goto drop;
1729
1730         sk = pt->af_packet_priv;
1731         po = pkt_sk(sk);
1732
1733         if (!net_eq(dev_net(dev), sock_net(sk)))
1734                 goto drop;
1735
1736         if (dev->header_ops) {
1737                 if (sk->sk_type != SOCK_DGRAM)
1738                         skb_push(skb, skb->data - skb_mac_header(skb));
1739                 else if (skb->pkt_type == PACKET_OUTGOING) {
1740                         /* Special case: outgoing packets have ll header at head */
1741                         skb_pull(skb, skb_network_offset(skb));
1742                 }
1743         }
1744
1745         if (skb->ip_summed == CHECKSUM_PARTIAL)
1746                 status |= TP_STATUS_CSUMNOTREADY;
1747
1748         snaplen = skb->len;
1749
1750         res = run_filter(skb, sk, snaplen);
1751         if (!res)
1752                 goto drop_n_restore;
1753         if (snaplen > res)
1754                 snaplen = res;
1755
1756         if (sk->sk_type == SOCK_DGRAM) {
1757                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1758                                   po->tp_reserve;
1759         } else {
1760                 unsigned int maclen = skb_network_offset(skb);
1761                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1762                                        (maclen < 16 ? 16 : maclen)) +
1763                         po->tp_reserve;
1764                 macoff = netoff - maclen;
1765         }
1766         if (po->tp_version <= TPACKET_V2) {
1767                 if (macoff + snaplen > po->rx_ring.frame_size) {
1768                         if (po->copy_thresh &&
1769                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1770                                 if (skb_shared(skb)) {
1771                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
1772                                 } else {
1773                                         copy_skb = skb_get(skb);
1774                                         skb_head = skb->data;
1775                                 }
1776                                 if (copy_skb)
1777                                         skb_set_owner_r(copy_skb, sk);
1778                         }
1779                         snaplen = po->rx_ring.frame_size - macoff;
1780                         if ((int)snaplen < 0)
1781                                 snaplen = 0;
1782                 }
1783         }
1784         spin_lock(&sk->sk_receive_queue.lock);
1785         h.raw = packet_current_rx_frame(po, skb,
1786                                         TP_STATUS_KERNEL, (macoff+snaplen));
1787         if (!h.raw)
1788                 goto ring_is_full;
1789         if (po->tp_version <= TPACKET_V2) {
1790                 packet_increment_rx_head(po, &po->rx_ring);
1791         /*
1792          * LOSING will be reported till you read the stats,
1793          * because it's COR - Clear On Read.
1794          * Anyways, moving it for V1/V2 only as V3 doesn't need this
1795          * at packet level.
1796          */
1797                 if (po->stats.tp_drops)
1798                         status |= TP_STATUS_LOSING;
1799         }
1800         po->stats.tp_packets++;
1801         if (copy_skb) {
1802                 status |= TP_STATUS_COPY;
1803                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1804         }
1805         spin_unlock(&sk->sk_receive_queue.lock);
1806
1807         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1808
1809         switch (po->tp_version) {
1810         case TPACKET_V1:
1811                 h.h1->tp_len = skb->len;
1812                 h.h1->tp_snaplen = snaplen;
1813                 h.h1->tp_mac = macoff;
1814                 h.h1->tp_net = netoff;
1815                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1816                                 && shhwtstamps->syststamp.tv64)
1817                         tv = ktime_to_timeval(shhwtstamps->syststamp);
1818                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1819                                 && shhwtstamps->hwtstamp.tv64)
1820                         tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1821                 else if (skb->tstamp.tv64)
1822                         tv = ktime_to_timeval(skb->tstamp);
1823                 else
1824                         do_gettimeofday(&tv);
1825                 h.h1->tp_sec = tv.tv_sec;
1826                 h.h1->tp_usec = tv.tv_usec;
1827                 hdrlen = sizeof(*h.h1);
1828                 break;
1829         case TPACKET_V2:
1830                 h.h2->tp_len = skb->len;
1831                 h.h2->tp_snaplen = snaplen;
1832                 h.h2->tp_mac = macoff;
1833                 h.h2->tp_net = netoff;
1834                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1835                                 && shhwtstamps->syststamp.tv64)
1836                         ts = ktime_to_timespec(shhwtstamps->syststamp);
1837                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1838                                 && shhwtstamps->hwtstamp.tv64)
1839                         ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1840                 else if (skb->tstamp.tv64)
1841                         ts = ktime_to_timespec(skb->tstamp);
1842                 else
1843                         getnstimeofday(&ts);
1844                 h.h2->tp_sec = ts.tv_sec;
1845                 h.h2->tp_nsec = ts.tv_nsec;
1846                 if (vlan_tx_tag_present(skb)) {
1847                         h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1848                         status |= TP_STATUS_VLAN_VALID;
1849                 } else {
1850                         h.h2->tp_vlan_tci = 0;
1851                 }
1852                 h.h2->tp_padding = 0;
1853                 hdrlen = sizeof(*h.h2);
1854                 break;
1855         case TPACKET_V3:
1856                 /* tp_nxt_offset,vlan are already populated above.
1857                  * So DONT clear those fields here
1858                  */
1859                 h.h3->tp_status |= status;
1860                 h.h3->tp_len = skb->len;
1861                 h.h3->tp_snaplen = snaplen;
1862                 h.h3->tp_mac = macoff;
1863                 h.h3->tp_net = netoff;
1864                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1865                                 && shhwtstamps->syststamp.tv64)
1866                         ts = ktime_to_timespec(shhwtstamps->syststamp);
1867                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1868                                 && shhwtstamps->hwtstamp.tv64)
1869                         ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1870                 else if (skb->tstamp.tv64)
1871                         ts = ktime_to_timespec(skb->tstamp);
1872                 else
1873                         getnstimeofday(&ts);
1874                 h.h3->tp_sec  = ts.tv_sec;
1875                 h.h3->tp_nsec = ts.tv_nsec;
1876                 hdrlen = sizeof(*h.h3);
1877                 break;
1878         default:
1879                 BUG();
1880         }
1881
1882         sll = h.raw + TPACKET_ALIGN(hdrlen);
1883         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1884         sll->sll_family = AF_PACKET;
1885         sll->sll_hatype = dev->type;
1886         sll->sll_protocol = skb->protocol;
1887         sll->sll_pkttype = skb->pkt_type;
1888         if (unlikely(po->origdev))
1889                 sll->sll_ifindex = orig_dev->ifindex;
1890         else
1891                 sll->sll_ifindex = dev->ifindex;
1892
1893         smp_mb();
1894 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1895         {
1896                 u8 *start, *end;
1897
1898                 if (po->tp_version <= TPACKET_V2) {
1899                         end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1900                                 + macoff + snaplen);
1901                         for (start = h.raw; start < end; start += PAGE_SIZE)
1902                                 flush_dcache_page(pgv_to_page(start));
1903                 }
1904                 smp_wmb();
1905         }
1906 #endif
1907         if (po->tp_version <= TPACKET_V2)
1908                 __packet_set_status(po, h.raw, status);
1909         else
1910                 prb_clear_blk_fill_status(&po->rx_ring);
1911
1912         sk->sk_data_ready(sk, 0);
1913
1914 drop_n_restore:
1915         if (skb_head != skb->data && skb_shared(skb)) {
1916                 skb->data = skb_head;
1917                 skb->len = skb_len;
1918         }
1919 drop:
1920         kfree_skb(skb);
1921         return 0;
1922
1923 ring_is_full:
1924         po->stats.tp_drops++;
1925         spin_unlock(&sk->sk_receive_queue.lock);
1926
1927         sk->sk_data_ready(sk, 0);
1928         kfree_skb(copy_skb);
1929         goto drop_n_restore;
1930 }
1931
1932 static void tpacket_destruct_skb(struct sk_buff *skb)
1933 {
1934         struct packet_sock *po = pkt_sk(skb->sk);
1935         void *ph;
1936
1937         if (likely(po->tx_ring.pg_vec)) {
1938                 ph = skb_shinfo(skb)->destructor_arg;
1939                 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1940                 atomic_dec(&po->tx_ring.pending);
1941                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1942         }
1943
1944         sock_wfree(skb);
1945 }
1946
1947 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1948                 void *frame, struct net_device *dev, int size_max,
1949                 __be16 proto, unsigned char *addr, int hlen)
1950 {
1951         union {
1952                 struct tpacket_hdr *h1;
1953                 struct tpacket2_hdr *h2;
1954                 void *raw;
1955         } ph;
1956         int to_write, offset, len, tp_len, nr_frags, len_max;
1957         struct socket *sock = po->sk.sk_socket;
1958         struct page *page;
1959         void *data;
1960         int err;
1961
1962         ph.raw = frame;
1963
1964         skb->protocol = proto;
1965         skb->dev = dev;
1966         skb->priority = po->sk.sk_priority;
1967         skb->mark = po->sk.sk_mark;
1968         skb_shinfo(skb)->destructor_arg = ph.raw;
1969
1970         switch (po->tp_version) {
1971         case TPACKET_V2:
1972                 tp_len = ph.h2->tp_len;
1973                 break;
1974         default:
1975                 tp_len = ph.h1->tp_len;
1976                 break;
1977         }
1978         if (unlikely(tp_len > size_max)) {
1979                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1980                 return -EMSGSIZE;
1981         }
1982
1983         skb_reserve(skb, hlen);
1984         skb_reset_network_header(skb);
1985
1986         data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1987         to_write = tp_len;
1988
1989         if (sock->type == SOCK_DGRAM) {
1990                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
1991                                 NULL, tp_len);
1992                 if (unlikely(err < 0))
1993                         return -EINVAL;
1994         } else if (dev->hard_header_len) {
1995                 /* net device doesn't like empty head */
1996                 if (unlikely(tp_len <= dev->hard_header_len)) {
1997                         pr_err("packet size is too short (%d < %d)\n",
1998                                tp_len, dev->hard_header_len);
1999                         return -EINVAL;
2000                 }
2001
2002                 skb_push(skb, dev->hard_header_len);
2003                 err = skb_store_bits(skb, 0, data,
2004                                 dev->hard_header_len);
2005                 if (unlikely(err))
2006                         return err;
2007
2008                 data += dev->hard_header_len;
2009                 to_write -= dev->hard_header_len;
2010         }
2011
2012         err = -EFAULT;
2013         offset = offset_in_page(data);
2014         len_max = PAGE_SIZE - offset;
2015         len = ((to_write > len_max) ? len_max : to_write);
2016
2017         skb->data_len = to_write;
2018         skb->len += to_write;
2019         skb->truesize += to_write;
2020         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2021
2022         while (likely(to_write)) {
2023                 nr_frags = skb_shinfo(skb)->nr_frags;
2024
2025                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2026                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2027                                MAX_SKB_FRAGS);
2028                         return -EFAULT;
2029                 }
2030
2031                 page = pgv_to_page(data);
2032                 data += len;
2033                 flush_dcache_page(page);
2034                 get_page(page);
2035                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2036                 to_write -= len;
2037                 offset = 0;
2038                 len_max = PAGE_SIZE;
2039                 len = ((to_write > len_max) ? len_max : to_write);
2040         }
2041
2042         return tp_len;
2043 }
2044
2045 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2046 {
2047         struct sk_buff *skb;
2048         struct net_device *dev;
2049         __be16 proto;
2050         bool need_rls_dev = false;
2051         int err, reserve = 0;
2052         void *ph;
2053         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2054         int tp_len, size_max;
2055         unsigned char *addr;
2056         int len_sum = 0;
2057         int status = 0;
2058         int hlen, tlen;
2059
2060         mutex_lock(&po->pg_vec_lock);
2061
2062         err = -EBUSY;
2063         if (saddr == NULL) {
2064                 dev = po->prot_hook.dev;
2065                 proto   = po->num;
2066                 addr    = NULL;
2067         } else {
2068                 err = -EINVAL;
2069                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2070                         goto out;
2071                 if (msg->msg_namelen < (saddr->sll_halen
2072                                         + offsetof(struct sockaddr_ll,
2073                                                 sll_addr)))
2074                         goto out;
2075                 proto   = saddr->sll_protocol;
2076                 addr    = saddr->sll_addr;
2077                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2078                 need_rls_dev = true;
2079         }
2080
2081         err = -ENXIO;
2082         if (unlikely(dev == NULL))
2083                 goto out;
2084
2085         reserve = dev->hard_header_len;
2086
2087         err = -ENETDOWN;
2088         if (unlikely(!(dev->flags & IFF_UP)))
2089                 goto out_put;
2090
2091         size_max = po->tx_ring.frame_size
2092                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2093
2094         if (size_max > dev->mtu + reserve)
2095                 size_max = dev->mtu + reserve;
2096
2097         do {
2098                 ph = packet_current_frame(po, &po->tx_ring,
2099                                 TP_STATUS_SEND_REQUEST);
2100
2101                 if (unlikely(ph == NULL)) {
2102                         schedule();
2103                         continue;
2104                 }
2105
2106                 status = TP_STATUS_SEND_REQUEST;
2107                 hlen = LL_RESERVED_SPACE(dev);
2108                 tlen = dev->needed_tailroom;
2109                 skb = sock_alloc_send_skb(&po->sk,
2110                                 hlen + tlen + sizeof(struct sockaddr_ll),
2111                                 0, &err);
2112
2113                 if (unlikely(skb == NULL))
2114                         goto out_status;
2115
2116                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2117                                 addr, hlen);
2118
2119                 if (unlikely(tp_len < 0)) {
2120                         if (po->tp_loss) {
2121                                 __packet_set_status(po, ph,
2122                                                 TP_STATUS_AVAILABLE);
2123                                 packet_increment_head(&po->tx_ring);
2124                                 kfree_skb(skb);
2125                                 continue;
2126                         } else {
2127                                 status = TP_STATUS_WRONG_FORMAT;
2128                                 err = tp_len;
2129                                 goto out_status;
2130                         }
2131                 }
2132
2133                 skb->destructor = tpacket_destruct_skb;
2134                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2135                 atomic_inc(&po->tx_ring.pending);
2136
2137                 status = TP_STATUS_SEND_REQUEST;
2138                 err = dev_queue_xmit(skb);
2139                 if (unlikely(err > 0)) {
2140                         err = net_xmit_errno(err);
2141                         if (err && __packet_get_status(po, ph) ==
2142                                    TP_STATUS_AVAILABLE) {
2143                                 /* skb was destructed already */
2144                                 skb = NULL;
2145                                 goto out_status;
2146                         }
2147                         /*
2148                          * skb was dropped but not destructed yet;
2149                          * let's treat it like congestion or err < 0
2150                          */
2151                         err = 0;
2152                 }
2153                 packet_increment_head(&po->tx_ring);
2154                 len_sum += tp_len;
2155         } while (likely((ph != NULL) ||
2156                         ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2157                          (atomic_read(&po->tx_ring.pending))))
2158                 );
2159
2160         err = len_sum;
2161         goto out_put;
2162
2163 out_status:
2164         __packet_set_status(po, ph, status);
2165         kfree_skb(skb);
2166 out_put:
2167         if (need_rls_dev)
2168                 dev_put(dev);
2169 out:
2170         mutex_unlock(&po->pg_vec_lock);
2171         return err;
2172 }
2173
2174 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2175                                         size_t reserve, size_t len,
2176                                         size_t linear, int noblock,
2177                                         int *err)
2178 {
2179         struct sk_buff *skb;
2180
2181         /* Under a page?  Don't bother with paged skb. */
2182         if (prepad + len < PAGE_SIZE || !linear)
2183                 linear = len;
2184
2185         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2186                                    err);
2187         if (!skb)
2188                 return NULL;
2189
2190         skb_reserve(skb, reserve);
2191         skb_put(skb, linear);
2192         skb->data_len = len - linear;
2193         skb->len += len - linear;
2194
2195         return skb;
2196 }
2197
2198 static int packet_snd(struct socket *sock,
2199                           struct msghdr *msg, size_t len)
2200 {
2201         struct sock *sk = sock->sk;
2202         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2203         struct sk_buff *skb;
2204         struct net_device *dev;
2205         __be16 proto;
2206         bool need_rls_dev = false;
2207         unsigned char *addr;
2208         int err, reserve = 0;
2209         struct virtio_net_hdr vnet_hdr = { 0 };
2210         int offset = 0;
2211         int vnet_hdr_len;
2212         struct packet_sock *po = pkt_sk(sk);
2213         unsigned short gso_type = 0;
2214         int hlen, tlen;
2215         int extra_len = 0;
2216
2217         /*
2218          *      Get and verify the address.
2219          */
2220
2221         if (saddr == NULL) {
2222                 dev = po->prot_hook.dev;
2223                 proto   = po->num;
2224                 addr    = NULL;
2225         } else {
2226                 err = -EINVAL;
2227                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2228                         goto out;
2229                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2230                         goto out;
2231                 proto   = saddr->sll_protocol;
2232                 addr    = saddr->sll_addr;
2233                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2234                 need_rls_dev = true;
2235         }
2236
2237         err = -ENXIO;
2238         if (dev == NULL)
2239                 goto out_unlock;
2240         if (sock->type == SOCK_RAW)
2241                 reserve = dev->hard_header_len;
2242
2243         err = -ENETDOWN;
2244         if (!(dev->flags & IFF_UP))
2245                 goto out_unlock;
2246
2247         if (po->has_vnet_hdr) {
2248                 vnet_hdr_len = sizeof(vnet_hdr);
2249
2250                 err = -EINVAL;
2251                 if (len < vnet_hdr_len)
2252                         goto out_unlock;
2253
2254                 len -= vnet_hdr_len;
2255
2256                 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2257                                        vnet_hdr_len);
2258                 if (err < 0)
2259                         goto out_unlock;
2260
2261                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2262                     (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2263                       vnet_hdr.hdr_len))
2264                         vnet_hdr.hdr_len = vnet_hdr.csum_start +
2265                                                  vnet_hdr.csum_offset + 2;
2266
2267                 err = -EINVAL;
2268                 if (vnet_hdr.hdr_len > len)
2269                         goto out_unlock;
2270
2271                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2272                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2273                         case VIRTIO_NET_HDR_GSO_TCPV4:
2274                                 gso_type = SKB_GSO_TCPV4;
2275                                 break;
2276                         case VIRTIO_NET_HDR_GSO_TCPV6:
2277                                 gso_type = SKB_GSO_TCPV6;
2278                                 break;
2279                         case VIRTIO_NET_HDR_GSO_UDP:
2280                                 gso_type = SKB_GSO_UDP;
2281                                 break;
2282                         default:
2283                                 goto out_unlock;
2284                         }
2285
2286                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2287                                 gso_type |= SKB_GSO_TCP_ECN;
2288
2289                         if (vnet_hdr.gso_size == 0)
2290                                 goto out_unlock;
2291
2292                 }
2293         }
2294
2295         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2296                 if (!netif_supports_nofcs(dev)) {
2297                         err = -EPROTONOSUPPORT;
2298                         goto out_unlock;
2299                 }
2300                 extra_len = 4; /* We're doing our own CRC */
2301         }
2302
2303         err = -EMSGSIZE;
2304         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2305                 goto out_unlock;
2306
2307         err = -ENOBUFS;
2308         hlen = LL_RESERVED_SPACE(dev);
2309         tlen = dev->needed_tailroom;
2310         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2311                                msg->msg_flags & MSG_DONTWAIT, &err);
2312         if (skb == NULL)
2313                 goto out_unlock;
2314
2315         skb_set_network_header(skb, reserve);
2316
2317         err = -EINVAL;
2318         if (sock->type == SOCK_DGRAM &&
2319             (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2320                 goto out_free;
2321
2322         /* Returns -EFAULT on error */
2323         err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2324         if (err)
2325                 goto out_free;
2326         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2327         if (err < 0)
2328                 goto out_free;
2329
2330         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2331                 /* Earlier code assumed this would be a VLAN pkt,
2332                  * double-check this now that we have the actual
2333                  * packet in hand.
2334                  */
2335                 struct ethhdr *ehdr;
2336                 skb_reset_mac_header(skb);
2337                 ehdr = eth_hdr(skb);
2338                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2339                         err = -EMSGSIZE;
2340                         goto out_free;
2341                 }
2342         }
2343
2344         skb->protocol = proto;
2345         skb->dev = dev;
2346         skb->priority = sk->sk_priority;
2347         skb->mark = sk->sk_mark;
2348
2349         if (po->has_vnet_hdr) {
2350                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2351                         if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2352                                                   vnet_hdr.csum_offset)) {
2353                                 err = -EINVAL;
2354                                 goto out_free;
2355                         }
2356                 }
2357
2358                 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2359                 skb_shinfo(skb)->gso_type = gso_type;
2360
2361                 /* Header must be checked, and gso_segs computed. */
2362                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2363                 skb_shinfo(skb)->gso_segs = 0;
2364
2365                 len += vnet_hdr_len;
2366         }
2367
2368         if (unlikely(extra_len == 4))
2369                 skb->no_fcs = 1;
2370
2371         /*
2372          *      Now send it
2373          */
2374
2375         err = dev_queue_xmit(skb);
2376         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2377                 goto out_unlock;
2378
2379         if (need_rls_dev)
2380                 dev_put(dev);
2381
2382         return len;
2383
2384 out_free:
2385         kfree_skb(skb);
2386 out_unlock:
2387         if (dev && need_rls_dev)
2388                 dev_put(dev);
2389 out:
2390         return err;
2391 }
2392
2393 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2394                 struct msghdr *msg, size_t len)
2395 {
2396         struct sock *sk = sock->sk;
2397         struct packet_sock *po = pkt_sk(sk);
2398         if (po->tx_ring.pg_vec)
2399                 return tpacket_snd(po, msg);
2400         else
2401                 return packet_snd(sock, msg, len);
2402 }
2403
2404 /*
2405  *      Close a PACKET socket. This is fairly simple. We immediately go
2406  *      to 'closed' state and remove our protocol entry in the device list.
2407  */
2408
2409 static int packet_release(struct socket *sock)
2410 {
2411         struct sock *sk = sock->sk;
2412         struct packet_sock *po;
2413         struct net *net;
2414         union tpacket_req_u req_u;
2415
2416         if (!sk)
2417                 return 0;
2418
2419         net = sock_net(sk);
2420         po = pkt_sk(sk);
2421
2422         spin_lock_bh(&net->packet.sklist_lock);
2423         sk_del_node_init_rcu(sk);
2424         sock_prot_inuse_add(net, sk->sk_prot, -1);
2425         spin_unlock_bh(&net->packet.sklist_lock);
2426
2427         spin_lock(&po->bind_lock);
2428         unregister_prot_hook(sk, false);
2429         if (po->prot_hook.dev) {
2430                 dev_put(po->prot_hook.dev);
2431                 po->prot_hook.dev = NULL;
2432         }
2433         spin_unlock(&po->bind_lock);
2434
2435         packet_flush_mclist(sk);
2436
2437         memset(&req_u, 0, sizeof(req_u));
2438
2439         if (po->rx_ring.pg_vec)
2440                 packet_set_ring(sk, &req_u, 1, 0);
2441
2442         if (po->tx_ring.pg_vec)
2443                 packet_set_ring(sk, &req_u, 1, 1);
2444
2445         fanout_release(sk);
2446
2447         synchronize_net();
2448         /*
2449          *      Now the socket is dead. No more input will appear.
2450          */
2451         sock_orphan(sk);
2452         sock->sk = NULL;
2453
2454         /* Purge queues */
2455
2456         skb_queue_purge(&sk->sk_receive_queue);
2457         sk_refcnt_debug_release(sk);
2458
2459         sock_put(sk);
2460         return 0;
2461 }
2462
2463 /*
2464  *      Attach a packet hook.
2465  */
2466
2467 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2468 {
2469         struct packet_sock *po = pkt_sk(sk);
2470
2471         if (po->fanout) {
2472                 if (dev)
2473                         dev_put(dev);
2474
2475                 return -EINVAL;
2476         }
2477
2478         lock_sock(sk);
2479
2480         spin_lock(&po->bind_lock);
2481         unregister_prot_hook(sk, true);
2482         po->num = protocol;
2483         po->prot_hook.type = protocol;
2484         if (po->prot_hook.dev)
2485                 dev_put(po->prot_hook.dev);
2486         po->prot_hook.dev = dev;
2487
2488         po->ifindex = dev ? dev->ifindex : 0;
2489
2490         if (protocol == 0)
2491                 goto out_unlock;
2492
2493         if (!dev || (dev->flags & IFF_UP)) {
2494                 register_prot_hook(sk);
2495         } else {
2496                 sk->sk_err = ENETDOWN;
2497                 if (!sock_flag(sk, SOCK_DEAD))
2498                         sk->sk_error_report(sk);
2499         }
2500
2501 out_unlock:
2502         spin_unlock(&po->bind_lock);
2503         release_sock(sk);
2504         return 0;
2505 }
2506
2507 /*
2508  *      Bind a packet socket to a device
2509  */
2510
2511 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2512                             int addr_len)
2513 {
2514         struct sock *sk = sock->sk;
2515         char name[15];
2516         struct net_device *dev;
2517         int err = -ENODEV;
2518
2519         /*
2520          *      Check legality
2521          */
2522
2523         if (addr_len != sizeof(struct sockaddr))
2524                 return -EINVAL;
2525         strlcpy(name, uaddr->sa_data, sizeof(name));
2526
2527         dev = dev_get_by_name(sock_net(sk), name);
2528         if (dev)
2529                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2530         return err;
2531 }
2532
2533 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2534 {
2535         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2536         struct sock *sk = sock->sk;
2537         struct net_device *dev = NULL;
2538         int err;
2539
2540
2541         /*
2542          *      Check legality
2543          */
2544
2545         if (addr_len < sizeof(struct sockaddr_ll))
2546                 return -EINVAL;
2547         if (sll->sll_family != AF_PACKET)
2548                 return -EINVAL;
2549
2550         if (sll->sll_ifindex) {
2551                 err = -ENODEV;
2552                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2553                 if (dev == NULL)
2554                         goto out;
2555         }
2556         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2557
2558 out:
2559         return err;
2560 }
2561
2562 static struct proto packet_proto = {
2563         .name     = "PACKET",
2564         .owner    = THIS_MODULE,
2565         .obj_size = sizeof(struct packet_sock),
2566 };
2567
2568 /*
2569  *      Create a packet of type SOCK_PACKET.
2570  */
2571
2572 static int packet_create(struct net *net, struct socket *sock, int protocol,
2573                          int kern)
2574 {
2575         struct sock *sk;
2576         struct packet_sock *po;
2577         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2578         int err;
2579
2580         if (!capable(CAP_NET_RAW))
2581                 return -EPERM;
2582         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2583             sock->type != SOCK_PACKET)
2584                 return -ESOCKTNOSUPPORT;
2585
2586         sock->state = SS_UNCONNECTED;
2587
2588         err = -ENOBUFS;
2589         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2590         if (sk == NULL)
2591                 goto out;
2592
2593         sock->ops = &packet_ops;
2594         if (sock->type == SOCK_PACKET)
2595                 sock->ops = &packet_ops_spkt;
2596
2597         sock_init_data(sock, sk);
2598
2599         po = pkt_sk(sk);
2600         sk->sk_family = PF_PACKET;
2601         po->num = proto;
2602
2603         sk->sk_destruct = packet_sock_destruct;
2604         sk_refcnt_debug_inc(sk);
2605
2606         /*
2607          *      Attach a protocol block
2608          */
2609
2610         spin_lock_init(&po->bind_lock);
2611         mutex_init(&po->pg_vec_lock);
2612         po->prot_hook.func = packet_rcv;
2613
2614         if (sock->type == SOCK_PACKET)
2615                 po->prot_hook.func = packet_rcv_spkt;
2616
2617         po->prot_hook.af_packet_priv = sk;
2618
2619         if (proto) {
2620                 po->prot_hook.type = proto;
2621                 register_prot_hook(sk);
2622         }
2623
2624         spin_lock_bh(&net->packet.sklist_lock);
2625         sk_add_node_rcu(sk, &net->packet.sklist);
2626         sock_prot_inuse_add(net, &packet_proto, 1);
2627         spin_unlock_bh(&net->packet.sklist_lock);
2628
2629         return 0;
2630 out:
2631         return err;
2632 }
2633
2634 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2635 {
2636         struct sock_exterr_skb *serr;
2637         struct sk_buff *skb, *skb2;
2638         int copied, err;
2639
2640         err = -EAGAIN;
2641         skb = skb_dequeue(&sk->sk_error_queue);
2642         if (skb == NULL)
2643                 goto out;
2644
2645         copied = skb->len;
2646         if (copied > len) {
2647                 msg->msg_flags |= MSG_TRUNC;
2648                 copied = len;
2649         }
2650         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2651         if (err)
2652                 goto out_free_skb;
2653
2654         sock_recv_timestamp(msg, sk, skb);
2655
2656         serr = SKB_EXT_ERR(skb);
2657         put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2658                  sizeof(serr->ee), &serr->ee);
2659
2660         msg->msg_flags |= MSG_ERRQUEUE;
2661         err = copied;
2662
2663         /* Reset and regenerate socket error */
2664         spin_lock_bh(&sk->sk_error_queue.lock);
2665         sk->sk_err = 0;
2666         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2667                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2668                 spin_unlock_bh(&sk->sk_error_queue.lock);
2669                 sk->sk_error_report(sk);
2670         } else
2671                 spin_unlock_bh(&sk->sk_error_queue.lock);
2672
2673 out_free_skb:
2674         kfree_skb(skb);
2675 out:
2676         return err;
2677 }
2678
2679 /*
2680  *      Pull a packet from our receive queue and hand it to the user.
2681  *      If necessary we block.
2682  */
2683
2684 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2685                           struct msghdr *msg, size_t len, int flags)
2686 {
2687         struct sock *sk = sock->sk;
2688         struct sk_buff *skb;
2689         int copied, err;
2690         struct sockaddr_ll *sll;
2691         int vnet_hdr_len = 0;
2692
2693         err = -EINVAL;
2694         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2695                 goto out;
2696
2697 #if 0
2698         /* What error should we return now? EUNATTACH? */
2699         if (pkt_sk(sk)->ifindex < 0)
2700                 return -ENODEV;
2701 #endif
2702
2703         if (flags & MSG_ERRQUEUE) {
2704                 err = packet_recv_error(sk, msg, len);
2705                 goto out;
2706         }
2707
2708         /*
2709          *      Call the generic datagram receiver. This handles all sorts
2710          *      of horrible races and re-entrancy so we can forget about it
2711          *      in the protocol layers.
2712          *
2713          *      Now it will return ENETDOWN, if device have just gone down,
2714          *      but then it will block.
2715          */
2716
2717         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2718
2719         /*
2720          *      An error occurred so return it. Because skb_recv_datagram()
2721          *      handles the blocking we don't see and worry about blocking
2722          *      retries.
2723          */
2724
2725         if (skb == NULL)
2726                 goto out;
2727
2728         if (pkt_sk(sk)->has_vnet_hdr) {
2729                 struct virtio_net_hdr vnet_hdr = { 0 };
2730
2731                 err = -EINVAL;
2732                 vnet_hdr_len = sizeof(vnet_hdr);
2733                 if (len < vnet_hdr_len)
2734                         goto out_free;
2735
2736                 len -= vnet_hdr_len;
2737
2738                 if (skb_is_gso(skb)) {
2739                         struct skb_shared_info *sinfo = skb_shinfo(skb);
2740
2741                         /* This is a hint as to how much should be linear. */
2742                         vnet_hdr.hdr_len = skb_headlen(skb);
2743                         vnet_hdr.gso_size = sinfo->gso_size;
2744                         if (sinfo->gso_type & SKB_GSO_TCPV4)
2745                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2746                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
2747                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2748                         else if (sinfo->gso_type & SKB_GSO_UDP)
2749                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2750                         else if (sinfo->gso_type & SKB_GSO_FCOE)
2751                                 goto out_free;
2752                         else
2753                                 BUG();
2754                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2755                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2756                 } else
2757                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2758
2759                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2760                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2761                         vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2762                         vnet_hdr.csum_offset = skb->csum_offset;
2763                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2764                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2765                 } /* else everything is zero */
2766
2767                 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2768                                      vnet_hdr_len);
2769                 if (err < 0)
2770                         goto out_free;
2771         }
2772
2773         /*
2774          *      If the address length field is there to be filled in, we fill
2775          *      it in now.
2776          */
2777
2778         sll = &PACKET_SKB_CB(skb)->sa.ll;
2779         if (sock->type == SOCK_PACKET)
2780                 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2781         else
2782                 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2783
2784         /*
2785          *      You lose any data beyond the buffer you gave. If it worries a
2786          *      user program they can ask the device for its MTU anyway.
2787          */
2788
2789         copied = skb->len;
2790         if (copied > len) {
2791                 copied = len;
2792                 msg->msg_flags |= MSG_TRUNC;
2793         }
2794
2795         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2796         if (err)
2797                 goto out_free;
2798
2799         sock_recv_ts_and_drops(msg, sk, skb);
2800
2801         if (msg->msg_name)
2802                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2803                        msg->msg_namelen);
2804
2805         if (pkt_sk(sk)->auxdata) {
2806                 struct tpacket_auxdata aux;
2807
2808                 aux.tp_status = TP_STATUS_USER;
2809                 if (skb->ip_summed == CHECKSUM_PARTIAL)
2810                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2811                 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2812                 aux.tp_snaplen = skb->len;
2813                 aux.tp_mac = 0;
2814                 aux.tp_net = skb_network_offset(skb);
2815                 if (vlan_tx_tag_present(skb)) {
2816                         aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2817                         aux.tp_status |= TP_STATUS_VLAN_VALID;
2818                 } else {
2819                         aux.tp_vlan_tci = 0;
2820                 }
2821                 aux.tp_padding = 0;
2822                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2823         }
2824
2825         /*
2826          *      Free or return the buffer as appropriate. Again this
2827          *      hides all the races and re-entrancy issues from us.
2828          */
2829         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2830
2831 out_free:
2832         skb_free_datagram(sk, skb);
2833 out:
2834         return err;
2835 }
2836
2837 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2838                                int *uaddr_len, int peer)
2839 {
2840         struct net_device *dev;
2841         struct sock *sk = sock->sk;
2842
2843         if (peer)
2844                 return -EOPNOTSUPP;
2845
2846         uaddr->sa_family = AF_PACKET;
2847         rcu_read_lock();
2848         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2849         if (dev)
2850                 strncpy(uaddr->sa_data, dev->name, 14);
2851         else
2852                 memset(uaddr->sa_data, 0, 14);
2853         rcu_read_unlock();
2854         *uaddr_len = sizeof(*uaddr);
2855
2856         return 0;
2857 }
2858
2859 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2860                           int *uaddr_len, int peer)
2861 {
2862         struct net_device *dev;
2863         struct sock *sk = sock->sk;
2864         struct packet_sock *po = pkt_sk(sk);
2865         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2866
2867         if (peer)
2868                 return -EOPNOTSUPP;
2869
2870         sll->sll_family = AF_PACKET;
2871         sll->sll_ifindex = po->ifindex;
2872         sll->sll_protocol = po->num;
2873         sll->sll_pkttype = 0;
2874         rcu_read_lock();
2875         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2876         if (dev) {
2877                 sll->sll_hatype = dev->type;
2878                 sll->sll_halen = dev->addr_len;
2879                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2880         } else {
2881                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
2882                 sll->sll_halen = 0;
2883         }
2884         rcu_read_unlock();
2885         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2886
2887         return 0;
2888 }
2889
2890 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2891                          int what)
2892 {
2893         switch (i->type) {
2894         case PACKET_MR_MULTICAST:
2895                 if (i->alen != dev->addr_len)
2896                         return -EINVAL;
2897                 if (what > 0)
2898                         return dev_mc_add(dev, i->addr);
2899                 else
2900                         return dev_mc_del(dev, i->addr);
2901                 break;
2902         case PACKET_MR_PROMISC:
2903                 return dev_set_promiscuity(dev, what);
2904                 break;
2905         case PACKET_MR_ALLMULTI:
2906                 return dev_set_allmulti(dev, what);
2907                 break;
2908         case PACKET_MR_UNICAST:
2909                 if (i->alen != dev->addr_len)
2910                         return -EINVAL;
2911                 if (what > 0)
2912                         return dev_uc_add(dev, i->addr);
2913                 else
2914                         return dev_uc_del(dev, i->addr);
2915                 break;
2916         default:
2917                 break;
2918         }
2919         return 0;
2920 }
2921
2922 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2923 {
2924         for ( ; i; i = i->next) {
2925                 if (i->ifindex == dev->ifindex)
2926                         packet_dev_mc(dev, i, what);
2927         }
2928 }
2929
2930 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2931 {
2932         struct packet_sock *po = pkt_sk(sk);
2933         struct packet_mclist *ml, *i;
2934         struct net_device *dev;
2935         int err;
2936
2937         rtnl_lock();
2938
2939         err = -ENODEV;
2940         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2941         if (!dev)
2942                 goto done;
2943
2944         err = -EINVAL;
2945         if (mreq->mr_alen > dev->addr_len)
2946                 goto done;
2947
2948         err = -ENOBUFS;
2949         i = kmalloc(sizeof(*i), GFP_KERNEL);
2950         if (i == NULL)
2951                 goto done;
2952
2953         err = 0;
2954         for (ml = po->mclist; ml; ml = ml->next) {
2955                 if (ml->ifindex == mreq->mr_ifindex &&
2956                     ml->type == mreq->mr_type &&
2957                     ml->alen == mreq->mr_alen &&
2958                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2959                         ml->count++;
2960                         /* Free the new element ... */
2961                         kfree(i);
2962                         goto done;
2963                 }
2964         }
2965
2966         i->type = mreq->mr_type;
2967         i->ifindex = mreq->mr_ifindex;
2968         i->alen = mreq->mr_alen;
2969         memcpy(i->addr, mreq->mr_address, i->alen);
2970         i->count = 1;
2971         i->next = po->mclist;
2972         po->mclist = i;
2973         err = packet_dev_mc(dev, i, 1);
2974         if (err) {
2975                 po->mclist = i->next;
2976                 kfree(i);
2977         }
2978
2979 done:
2980         rtnl_unlock();
2981         return err;
2982 }
2983
2984 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2985 {
2986         struct packet_mclist *ml, **mlp;
2987
2988         rtnl_lock();
2989
2990         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2991                 if (ml->ifindex == mreq->mr_ifindex &&
2992                     ml->type == mreq->mr_type &&
2993                     ml->alen == mreq->mr_alen &&
2994                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2995                         if (--ml->count == 0) {
2996                                 struct net_device *dev;
2997                                 *mlp = ml->next;
2998                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2999                                 if (dev)
3000                                         packet_dev_mc(dev, ml, -1);
3001                                 kfree(ml);
3002                         }
3003                         rtnl_unlock();
3004                         return 0;
3005                 }
3006         }
3007         rtnl_unlock();
3008         return -EADDRNOTAVAIL;
3009 }
3010
3011 static void packet_flush_mclist(struct sock *sk)
3012 {
3013         struct packet_sock *po = pkt_sk(sk);
3014         struct packet_mclist *ml;
3015
3016         if (!po->mclist)
3017                 return;
3018
3019         rtnl_lock();
3020         while ((ml = po->mclist) != NULL) {
3021                 struct net_device *dev;
3022
3023                 po->mclist = ml->next;
3024                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3025                 if (dev != NULL)
3026                         packet_dev_mc(dev, ml, -1);
3027                 kfree(ml);
3028         }
3029         rtnl_unlock();
3030 }
3031
3032 static int
3033 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3034 {
3035         struct sock *sk = sock->sk;
3036         struct packet_sock *po = pkt_sk(sk);
3037         int ret;
3038
3039         if (level != SOL_PACKET)
3040                 return -ENOPROTOOPT;
3041
3042         switch (optname) {
3043         case PACKET_ADD_MEMBERSHIP:
3044         case PACKET_DROP_MEMBERSHIP:
3045         {
3046                 struct packet_mreq_max mreq;
3047                 int len = optlen;
3048                 memset(&mreq, 0, sizeof(mreq));
3049                 if (len < sizeof(struct packet_mreq))
3050                         return -EINVAL;
3051                 if (len > sizeof(mreq))
3052                         len = sizeof(mreq);
3053                 if (copy_from_user(&mreq, optval, len))
3054                         return -EFAULT;
3055                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3056                         return -EINVAL;
3057                 if (optname == PACKET_ADD_MEMBERSHIP)
3058                         ret = packet_mc_add(sk, &mreq);
3059                 else
3060                         ret = packet_mc_drop(sk, &mreq);
3061                 return ret;
3062         }
3063
3064         case PACKET_RX_RING:
3065         case PACKET_TX_RING:
3066         {
3067                 union tpacket_req_u req_u;
3068                 int len;
3069
3070                 switch (po->tp_version) {
3071                 case TPACKET_V1:
3072                 case TPACKET_V2:
3073                         len = sizeof(req_u.req);
3074                         break;
3075                 case TPACKET_V3:
3076                 default:
3077                         len = sizeof(req_u.req3);
3078                         break;
3079                 }
3080                 if (optlen < len)
3081                         return -EINVAL;
3082                 if (pkt_sk(sk)->has_vnet_hdr)
3083                         return -EINVAL;
3084                 if (copy_from_user(&req_u.req, optval, len))
3085                         return -EFAULT;
3086                 return packet_set_ring(sk, &req_u, 0,
3087                         optname == PACKET_TX_RING);
3088         }
3089         case PACKET_COPY_THRESH:
3090         {
3091                 int val;
3092
3093                 if (optlen != sizeof(val))
3094                         return -EINVAL;
3095                 if (copy_from_user(&val, optval, sizeof(val)))
3096                         return -EFAULT;
3097
3098                 pkt_sk(sk)->copy_thresh = val;
3099                 return 0;
3100         }
3101         case PACKET_VERSION:
3102         {
3103                 int val;
3104
3105                 if (optlen != sizeof(val))
3106                         return -EINVAL;
3107                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3108                         return -EBUSY;
3109                 if (copy_from_user(&val, optval, sizeof(val)))
3110                         return -EFAULT;
3111                 switch (val) {
3112                 case TPACKET_V1:
3113                 case TPACKET_V2:
3114                 case TPACKET_V3:
3115                         po->tp_version = val;
3116                         return 0;
3117                 default:
3118                         return -EINVAL;
3119                 }
3120         }
3121         case PACKET_RESERVE:
3122         {
3123                 unsigned int val;
3124
3125                 if (optlen != sizeof(val))
3126                         return -EINVAL;
3127                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3128                         return -EBUSY;
3129                 if (copy_from_user(&val, optval, sizeof(val)))
3130                         return -EFAULT;
3131                 po->tp_reserve = val;
3132                 return 0;
3133         }
3134         case PACKET_LOSS:
3135         {
3136                 unsigned int val;
3137
3138                 if (optlen != sizeof(val))
3139                         return -EINVAL;
3140                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3141                         return -EBUSY;
3142                 if (copy_from_user(&val, optval, sizeof(val)))
3143                         return -EFAULT;
3144                 po->tp_loss = !!val;
3145                 return 0;
3146         }
3147         case PACKET_AUXDATA:
3148         {
3149                 int val;
3150
3151                 if (optlen < sizeof(val))
3152                         return -EINVAL;
3153                 if (copy_from_user(&val, optval, sizeof(val)))
3154                         return -EFAULT;
3155
3156                 po->auxdata = !!val;
3157                 return 0;
3158         }
3159         case PACKET_ORIGDEV:
3160         {
3161                 int val;
3162
3163                 if (optlen < sizeof(val))
3164                         return -EINVAL;
3165                 if (copy_from_user(&val, optval, sizeof(val)))
3166                         return -EFAULT;
3167
3168                 po->origdev = !!val;
3169                 return 0;
3170         }
3171         case PACKET_VNET_HDR:
3172         {
3173                 int val;
3174
3175                 if (sock->type != SOCK_RAW)
3176                         return -EINVAL;
3177                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3178                         return -EBUSY;
3179                 if (optlen < sizeof(val))
3180                         return -EINVAL;
3181                 if (copy_from_user(&val, optval, sizeof(val)))
3182                         return -EFAULT;
3183
3184                 po->has_vnet_hdr = !!val;
3185                 return 0;
3186         }
3187         case PACKET_TIMESTAMP:
3188         {
3189                 int val;
3190
3191                 if (optlen != sizeof(val))
3192                         return -EINVAL;
3193                 if (copy_from_user(&val, optval, sizeof(val)))
3194                         return -EFAULT;
3195
3196                 po->tp_tstamp = val;
3197                 return 0;
3198         }
3199         case PACKET_FANOUT:
3200         {
3201                 int val;
3202
3203                 if (optlen != sizeof(val))
3204                         return -EINVAL;
3205                 if (copy_from_user(&val, optval, sizeof(val)))
3206                         return -EFAULT;
3207
3208                 return fanout_add(sk, val & 0xffff, val >> 16);
3209         }
3210         default:
3211                 return -ENOPROTOOPT;
3212         }
3213 }
3214
3215 static int packet_getsockopt(struct socket *sock, int level, int optname,
3216                              char __user *optval, int __user *optlen)
3217 {
3218         int len;
3219         int val, lv = sizeof(val);
3220         struct sock *sk = sock->sk;
3221         struct packet_sock *po = pkt_sk(sk);
3222         void *data = &val;
3223         struct tpacket_stats st;
3224         union tpacket_stats_u st_u;
3225
3226         if (level != SOL_PACKET)
3227                 return -ENOPROTOOPT;
3228
3229         if (get_user(len, optlen))
3230                 return -EFAULT;
3231
3232         if (len < 0)
3233                 return -EINVAL;
3234
3235         switch (optname) {
3236         case PACKET_STATISTICS:
3237                 spin_lock_bh(&sk->sk_receive_queue.lock);
3238                 if (po->tp_version == TPACKET_V3) {
3239                         lv = sizeof(struct tpacket_stats_v3);
3240                         memcpy(&st_u.stats3, &po->stats,
3241                                sizeof(struct tpacket_stats));
3242                         st_u.stats3.tp_freeze_q_cnt =
3243                                         po->stats_u.stats3.tp_freeze_q_cnt;
3244                         st_u.stats3.tp_packets += po->stats.tp_drops;
3245                         data = &st_u.stats3;
3246                 } else {
3247                         lv = sizeof(struct tpacket_stats);
3248                         st = po->stats;
3249                         st.tp_packets += st.tp_drops;
3250                         data = &st;
3251                 }
3252                 memset(&po->stats, 0, sizeof(st));
3253                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3254                 break;
3255         case PACKET_AUXDATA:
3256                 val = po->auxdata;
3257                 break;
3258         case PACKET_ORIGDEV:
3259                 val = po->origdev;
3260                 break;
3261         case PACKET_VNET_HDR:
3262                 val = po->has_vnet_hdr;
3263                 break;
3264         case PACKET_VERSION:
3265                 val = po->tp_version;
3266                 break;
3267         case PACKET_HDRLEN:
3268                 if (len > sizeof(int))
3269                         len = sizeof(int);
3270                 if (copy_from_user(&val, optval, len))
3271                         return -EFAULT;
3272                 switch (val) {
3273                 case TPACKET_V1:
3274                         val = sizeof(struct tpacket_hdr);
3275                         break;
3276                 case TPACKET_V2:
3277                         val = sizeof(struct tpacket2_hdr);
3278                         break;
3279                 case TPACKET_V3:
3280                         val = sizeof(struct tpacket3_hdr);
3281                         break;
3282                 default:
3283                         return -EINVAL;
3284                 }
3285                 break;
3286         case PACKET_RESERVE:
3287                 val = po->tp_reserve;
3288                 break;
3289         case PACKET_LOSS:
3290                 val = po->tp_loss;
3291                 break;
3292         case PACKET_TIMESTAMP:
3293                 val = po->tp_tstamp;
3294                 break;
3295         case PACKET_FANOUT:
3296                 val = (po->fanout ?
3297                        ((u32)po->fanout->id |
3298                         ((u32)po->fanout->type << 16)) :
3299                        0);
3300                 break;
3301         default:
3302                 return -ENOPROTOOPT;
3303         }
3304
3305         if (len > lv)
3306                 len = lv;
3307         if (put_user(len, optlen))
3308                 return -EFAULT;
3309         if (copy_to_user(optval, data, len))
3310                 return -EFAULT;
3311         return 0;
3312 }
3313
3314
3315 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3316 {
3317         struct sock *sk;
3318         struct hlist_node *node;
3319         struct net_device *dev = data;
3320         struct net *net = dev_net(dev);
3321
3322         rcu_read_lock();
3323         sk_for_each_rcu(sk, node, &net->packet.sklist) {
3324                 struct packet_sock *po = pkt_sk(sk);
3325
3326                 switch (msg) {
3327                 case NETDEV_UNREGISTER:
3328                         if (po->mclist)
3329                                 packet_dev_mclist(dev, po->mclist, -1);
3330                         /* fallthrough */
3331
3332                 case NETDEV_DOWN:
3333                         if (dev->ifindex == po->ifindex) {
3334                                 spin_lock(&po->bind_lock);
3335                                 if (po->running) {
3336                                         __unregister_prot_hook(sk, false);
3337                                         sk->sk_err = ENETDOWN;
3338                                         if (!sock_flag(sk, SOCK_DEAD))
3339                                                 sk->sk_error_report(sk);
3340                                 }
3341                                 if (msg == NETDEV_UNREGISTER) {
3342                                         po->ifindex = -1;
3343                                         if (po->prot_hook.dev)
3344                                                 dev_put(po->prot_hook.dev);
3345                                         po->prot_hook.dev = NULL;
3346                                 }
3347                                 spin_unlock(&po->bind_lock);
3348                         }
3349                         break;
3350                 case NETDEV_UP:
3351                         if (dev->ifindex == po->ifindex) {
3352                                 spin_lock(&po->bind_lock);
3353                                 if (po->num)
3354                                         register_prot_hook(sk);
3355                                 spin_unlock(&po->bind_lock);
3356                         }
3357                         break;
3358                 }
3359         }
3360         rcu_read_unlock();
3361         return NOTIFY_DONE;
3362 }
3363
3364
3365 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3366                         unsigned long arg)
3367 {
3368         struct sock *sk = sock->sk;
3369
3370         switch (cmd) {
3371         case SIOCOUTQ:
3372         {
3373                 int amount = sk_wmem_alloc_get(sk);
3374
3375                 return put_user(amount, (int __user *)arg);
3376         }
3377         case SIOCINQ:
3378         {
3379                 struct sk_buff *skb;
3380                 int amount = 0;
3381
3382                 spin_lock_bh(&sk->sk_receive_queue.lock);
3383                 skb = skb_peek(&sk->sk_receive_queue);
3384                 if (skb)
3385                         amount = skb->len;
3386                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3387                 return put_user(amount, (int __user *)arg);
3388         }
3389         case SIOCGSTAMP:
3390                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3391         case SIOCGSTAMPNS:
3392                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3393
3394 #ifdef CONFIG_INET
3395         case SIOCADDRT:
3396         case SIOCDELRT:
3397         case SIOCDARP:
3398         case SIOCGARP:
3399         case SIOCSARP:
3400         case SIOCGIFADDR:
3401         case SIOCSIFADDR:
3402         case SIOCGIFBRDADDR:
3403         case SIOCSIFBRDADDR:
3404         case SIOCGIFNETMASK:
3405         case SIOCSIFNETMASK:
3406         case SIOCGIFDSTADDR:
3407         case SIOCSIFDSTADDR:
3408         case SIOCSIFFLAGS:
3409                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3410 #endif
3411
3412         default:
3413                 return -ENOIOCTLCMD;
3414         }
3415         return 0;
3416 }
3417
3418 static unsigned int packet_poll(struct file *file, struct socket *sock,
3419                                 poll_table *wait)
3420 {
3421         struct sock *sk = sock->sk;
3422         struct packet_sock *po = pkt_sk(sk);
3423         unsigned int mask = datagram_poll(file, sock, wait);
3424
3425         spin_lock_bh(&sk->sk_receive_queue.lock);
3426         if (po->rx_ring.pg_vec) {
3427                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3428                         TP_STATUS_KERNEL))
3429                         mask |= POLLIN | POLLRDNORM;
3430         }
3431         spin_unlock_bh(&sk->sk_receive_queue.lock);
3432         spin_lock_bh(&sk->sk_write_queue.lock);
3433         if (po->tx_ring.pg_vec) {
3434                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3435                         mask |= POLLOUT | POLLWRNORM;
3436         }
3437         spin_unlock_bh(&sk->sk_write_queue.lock);
3438         return mask;
3439 }
3440
3441
3442 /* Dirty? Well, I still did not learn better way to account
3443  * for user mmaps.
3444  */
3445
3446 static void packet_mm_open(struct vm_area_struct *vma)
3447 {
3448         struct file *file = vma->vm_file;
3449         struct socket *sock = file->private_data;
3450         struct sock *sk = sock->sk;
3451
3452         if (sk)
3453                 atomic_inc(&pkt_sk(sk)->mapped);
3454 }
3455
3456 static void packet_mm_close(struct vm_area_struct *vma)
3457 {
3458         struct file *file = vma->vm_file;
3459         struct socket *sock = file->private_data;
3460         struct sock *sk = sock->sk;
3461
3462         if (sk)
3463                 atomic_dec(&pkt_sk(sk)->mapped);
3464 }
3465
3466 static const struct vm_operations_struct packet_mmap_ops = {
3467         .open   =       packet_mm_open,
3468         .close  =       packet_mm_close,
3469 };
3470
3471 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3472                         unsigned int len)
3473 {
3474         int i;
3475
3476         for (i = 0; i < len; i++) {
3477                 if (likely(pg_vec[i].buffer)) {
3478                         if (is_vmalloc_addr(pg_vec[i].buffer))
3479                                 vfree(pg_vec[i].buffer);
3480                         else
3481                                 free_pages((unsigned long)pg_vec[i].buffer,
3482                                            order);
3483                         pg_vec[i].buffer = NULL;
3484                 }
3485         }
3486         kfree(pg_vec);
3487 }
3488
3489 static char *alloc_one_pg_vec_page(unsigned long order)
3490 {
3491         char *buffer = NULL;
3492         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3493                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3494
3495         buffer = (char *) __get_free_pages(gfp_flags, order);
3496
3497         if (buffer)
3498                 return buffer;
3499
3500         /*
3501          * __get_free_pages failed, fall back to vmalloc
3502          */
3503         buffer = vzalloc((1 << order) * PAGE_SIZE);
3504
3505         if (buffer)
3506                 return buffer;
3507
3508         /*
3509          * vmalloc failed, lets dig into swap here
3510          */
3511         gfp_flags &= ~__GFP_NORETRY;
3512         buffer = (char *)__get_free_pages(gfp_flags, order);
3513         if (buffer)
3514                 return buffer;
3515
3516         /*
3517          * complete and utter failure
3518          */
3519         return NULL;
3520 }
3521
3522 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3523 {
3524         unsigned int block_nr = req->tp_block_nr;
3525         struct pgv *pg_vec;
3526         int i;
3527
3528         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3529         if (unlikely(!pg_vec))
3530                 goto out;
3531
3532         for (i = 0; i < block_nr; i++) {
3533                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3534                 if (unlikely(!pg_vec[i].buffer))
3535                         goto out_free_pgvec;
3536         }
3537
3538 out:
3539         return pg_vec;
3540
3541 out_free_pgvec:
3542         free_pg_vec(pg_vec, order, block_nr);
3543         pg_vec = NULL;
3544         goto out;
3545 }
3546
3547 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3548                 int closing, int tx_ring)
3549 {
3550         struct pgv *pg_vec = NULL;
3551         struct packet_sock *po = pkt_sk(sk);
3552         int was_running, order = 0;
3553         struct packet_ring_buffer *rb;
3554         struct sk_buff_head *rb_queue;
3555         __be16 num;
3556         int err = -EINVAL;
3557         /* Added to avoid minimal code churn */
3558         struct tpacket_req *req = &req_u->req;
3559
3560         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3561         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3562                 WARN(1, "Tx-ring is not supported.\n");
3563                 goto out;
3564         }
3565
3566         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3567         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3568
3569         err = -EBUSY;
3570         if (!closing) {
3571                 if (atomic_read(&po->mapped))
3572                         goto out;
3573                 if (atomic_read(&rb->pending))
3574                         goto out;
3575         }
3576
3577         if (req->tp_block_nr) {
3578                 /* Sanity tests and some calculations */
3579                 err = -EBUSY;
3580                 if (unlikely(rb->pg_vec))
3581                         goto out;
3582
3583                 switch (po->tp_version) {
3584                 case TPACKET_V1:
3585                         po->tp_hdrlen = TPACKET_HDRLEN;
3586                         break;
3587                 case TPACKET_V2:
3588                         po->tp_hdrlen = TPACKET2_HDRLEN;
3589                         break;
3590                 case TPACKET_V3:
3591                         po->tp_hdrlen = TPACKET3_HDRLEN;
3592                         break;
3593                 }
3594
3595                 err = -EINVAL;
3596                 if (unlikely((int)req->tp_block_size <= 0))
3597                         goto out;
3598                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3599                         goto out;
3600                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3601                                         po->tp_reserve))
3602                         goto out;
3603                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3604                         goto out;
3605
3606                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3607                 if (unlikely(rb->frames_per_block <= 0))
3608                         goto out;
3609                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3610                                         req->tp_frame_nr))
3611                         goto out;
3612
3613                 err = -ENOMEM;
3614                 order = get_order(req->tp_block_size);
3615                 pg_vec = alloc_pg_vec(req, order);
3616                 if (unlikely(!pg_vec))
3617                         goto out;
3618                 switch (po->tp_version) {
3619                 case TPACKET_V3:
3620                 /* Transmit path is not supported. We checked
3621                  * it above but just being paranoid
3622                  */
3623                         if (!tx_ring)
3624                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3625                                 break;
3626                 default:
3627                         break;
3628                 }
3629         }
3630         /* Done */
3631         else {
3632                 err = -EINVAL;
3633                 if (unlikely(req->tp_frame_nr))
3634                         goto out;
3635         }
3636
3637         lock_sock(sk);
3638
3639         /* Detach socket from network */
3640         spin_lock(&po->bind_lock);
3641         was_running = po->running;
3642         num = po->num;
3643         if (was_running) {
3644                 po->num = 0;
3645                 __unregister_prot_hook(sk, false);
3646         }
3647         spin_unlock(&po->bind_lock);
3648
3649         synchronize_net();
3650
3651         err = -EBUSY;
3652         mutex_lock(&po->pg_vec_lock);
3653         if (closing || atomic_read(&po->mapped) == 0) {
3654                 err = 0;
3655                 spin_lock_bh(&rb_queue->lock);
3656                 swap(rb->pg_vec, pg_vec);
3657                 rb->frame_max = (req->tp_frame_nr - 1);
3658                 rb->head = 0;
3659                 rb->frame_size = req->tp_frame_size;
3660                 spin_unlock_bh(&rb_queue->lock);
3661
3662                 swap(rb->pg_vec_order, order);
3663                 swap(rb->pg_vec_len, req->tp_block_nr);
3664
3665                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3666                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3667                                                 tpacket_rcv : packet_rcv;
3668                 skb_queue_purge(rb_queue);
3669                 if (atomic_read(&po->mapped))
3670                         pr_err("packet_mmap: vma is busy: %d\n",
3671                                atomic_read(&po->mapped));
3672         }
3673         mutex_unlock(&po->pg_vec_lock);
3674
3675         spin_lock(&po->bind_lock);
3676         if (was_running) {
3677                 po->num = num;
3678                 register_prot_hook(sk);
3679         }
3680         spin_unlock(&po->bind_lock);
3681         if (closing && (po->tp_version > TPACKET_V2)) {
3682                 /* Because we don't support block-based V3 on tx-ring */
3683                 if (!tx_ring)
3684                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3685         }
3686         release_sock(sk);
3687
3688         if (pg_vec)
3689                 free_pg_vec(pg_vec, order, req->tp_block_nr);
3690 out:
3691         return err;
3692 }
3693
3694 static int packet_mmap(struct file *file, struct socket *sock,
3695                 struct vm_area_struct *vma)
3696 {
3697         struct sock *sk = sock->sk;
3698         struct packet_sock *po = pkt_sk(sk);
3699         unsigned long size, expected_size;
3700         struct packet_ring_buffer *rb;
3701         unsigned long start;
3702         int err = -EINVAL;
3703         int i;
3704
3705         if (vma->vm_pgoff)
3706                 return -EINVAL;
3707
3708         mutex_lock(&po->pg_vec_lock);
3709
3710         expected_size = 0;
3711         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3712                 if (rb->pg_vec) {
3713                         expected_size += rb->pg_vec_len
3714                                                 * rb->pg_vec_pages
3715                                                 * PAGE_SIZE;
3716                 }
3717         }
3718
3719         if (expected_size == 0)
3720                 goto out;
3721
3722         size = vma->vm_end - vma->vm_start;
3723         if (size != expected_size)
3724                 goto out;
3725
3726         start = vma->vm_start;
3727         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3728                 if (rb->pg_vec == NULL)
3729                         continue;
3730
3731                 for (i = 0; i < rb->pg_vec_len; i++) {
3732                         struct page *page;
3733                         void *kaddr = rb->pg_vec[i].buffer;
3734                         int pg_num;
3735
3736                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3737                                 page = pgv_to_page(kaddr);
3738                                 err = vm_insert_page(vma, start, page);
3739                                 if (unlikely(err))
3740                                         goto out;
3741                                 start += PAGE_SIZE;
3742                                 kaddr += PAGE_SIZE;
3743                         }
3744                 }
3745         }
3746
3747         atomic_inc(&po->mapped);
3748         vma->vm_ops = &packet_mmap_ops;
3749         err = 0;
3750
3751 out:
3752         mutex_unlock(&po->pg_vec_lock);
3753         return err;
3754 }
3755
3756 static const struct proto_ops packet_ops_spkt = {
3757         .family =       PF_PACKET,
3758         .owner =        THIS_MODULE,
3759         .release =      packet_release,
3760         .bind =         packet_bind_spkt,
3761         .connect =      sock_no_connect,
3762         .socketpair =   sock_no_socketpair,
3763         .accept =       sock_no_accept,
3764         .getname =      packet_getname_spkt,
3765         .poll =         datagram_poll,
3766         .ioctl =        packet_ioctl,
3767         .listen =       sock_no_listen,
3768         .shutdown =     sock_no_shutdown,
3769         .setsockopt =   sock_no_setsockopt,
3770         .getsockopt =   sock_no_getsockopt,
3771         .sendmsg =      packet_sendmsg_spkt,
3772         .recvmsg =      packet_recvmsg,
3773         .mmap =         sock_no_mmap,
3774         .sendpage =     sock_no_sendpage,
3775 };
3776
3777 static const struct proto_ops packet_ops = {
3778         .family =       PF_PACKET,
3779         .owner =        THIS_MODULE,
3780         .release =      packet_release,
3781         .bind =         packet_bind,
3782         .connect =      sock_no_connect,
3783         .socketpair =   sock_no_socketpair,
3784         .accept =       sock_no_accept,
3785         .getname =      packet_getname,
3786         .poll =         packet_poll,
3787         .ioctl =        packet_ioctl,
3788         .listen =       sock_no_listen,
3789         .shutdown =     sock_no_shutdown,
3790         .setsockopt =   packet_setsockopt,
3791         .getsockopt =   packet_getsockopt,
3792         .sendmsg =      packet_sendmsg,
3793         .recvmsg =      packet_recvmsg,
3794         .mmap =         packet_mmap,
3795         .sendpage =     sock_no_sendpage,
3796 };
3797
3798 static const struct net_proto_family packet_family_ops = {
3799         .family =       PF_PACKET,
3800         .create =       packet_create,
3801         .owner  =       THIS_MODULE,
3802 };
3803
3804 static struct notifier_block packet_netdev_notifier = {
3805         .notifier_call =        packet_notifier,
3806 };
3807
3808 #ifdef CONFIG_PROC_FS
3809
3810 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3811         __acquires(RCU)
3812 {
3813         struct net *net = seq_file_net(seq);
3814
3815         rcu_read_lock();
3816         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3817 }
3818
3819 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3820 {
3821         struct net *net = seq_file_net(seq);
3822         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3823 }
3824
3825 static void packet_seq_stop(struct seq_file *seq, void *v)
3826         __releases(RCU)
3827 {
3828         rcu_read_unlock();
3829 }
3830
3831 static int packet_seq_show(struct seq_file *seq, void *v)
3832 {
3833         if (v == SEQ_START_TOKEN)
3834                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
3835         else {
3836                 struct sock *s = sk_entry(v);
3837                 const struct packet_sock *po = pkt_sk(s);
3838
3839                 seq_printf(seq,
3840                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
3841                            s,
3842                            atomic_read(&s->sk_refcnt),
3843                            s->sk_type,
3844                            ntohs(po->num),
3845                            po->ifindex,
3846                            po->running,
3847                            atomic_read(&s->sk_rmem_alloc),
3848                            sock_i_uid(s),
3849                            sock_i_ino(s));
3850         }
3851
3852         return 0;
3853 }
3854
3855 static const struct seq_operations packet_seq_ops = {
3856         .start  = packet_seq_start,
3857         .next   = packet_seq_next,
3858         .stop   = packet_seq_stop,
3859         .show   = packet_seq_show,
3860 };
3861
3862 static int packet_seq_open(struct inode *inode, struct file *file)
3863 {
3864         return seq_open_net(inode, file, &packet_seq_ops,
3865                             sizeof(struct seq_net_private));
3866 }
3867
3868 static const struct file_operations packet_seq_fops = {
3869         .owner          = THIS_MODULE,
3870         .open           = packet_seq_open,
3871         .read           = seq_read,
3872         .llseek         = seq_lseek,
3873         .release        = seq_release_net,
3874 };
3875
3876 #endif
3877
3878 static int __net_init packet_net_init(struct net *net)
3879 {
3880         spin_lock_init(&net->packet.sklist_lock);
3881         INIT_HLIST_HEAD(&net->packet.sklist);
3882
3883         if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3884                 return -ENOMEM;
3885
3886         return 0;
3887 }
3888
3889 static void __net_exit packet_net_exit(struct net *net)
3890 {
3891         proc_net_remove(net, "packet");
3892 }
3893
3894 static struct pernet_operations packet_net_ops = {
3895         .init = packet_net_init,
3896         .exit = packet_net_exit,
3897 };
3898
3899
3900 static void __exit packet_exit(void)
3901 {
3902         unregister_netdevice_notifier(&packet_netdev_notifier);
3903         unregister_pernet_subsys(&packet_net_ops);
3904         sock_unregister(PF_PACKET);
3905         proto_unregister(&packet_proto);
3906 }
3907
3908 static int __init packet_init(void)
3909 {
3910         int rc = proto_register(&packet_proto, 0);
3911
3912         if (rc != 0)
3913                 goto out;
3914
3915         sock_register(&packet_family_ops);
3916         register_pernet_subsys(&packet_net_ops);
3917         register_netdevice_notifier(&packet_netdev_notifier);
3918 out:
3919         return rc;
3920 }
3921
3922 module_init(packet_init);
3923 module_exit(packet_exit);
3924 MODULE_LICENSE("GPL");
3925 MODULE_ALIAS_NETPROTO(PF_PACKET);