net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "hard-interface.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/gfp.h>
  13 #include <linux/if.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/kernel.h>
  17 #include <linux/kref.h>
  18 #include <linux/limits.h>
  19 #include <linux/list.h>
  20 #include <linux/minmax.h>
  21 #include <linux/mutex.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/printk.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rtnetlink.h>
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <net/net_namespace.h>
  29 #include <net/rtnetlink.h>
  30 #include <uapi/linux/batadv_packet.h>
  31
  32 #include "bat_v.h"
  33 #include "bridge_loop_avoidance.h"
  34 #include "distributed-arp-table.h"
  35 #include "gateway_client.h"
  36 #include "log.h"
  37 #include "originator.h"
  38 #include "send.h"
  39 #include "soft-interface.h"
  40 #include "translation-table.h"
  41
  42 /**
  43  * batadv_hardif_release() - release hard interface from lists and queue for
  44  *  free after rcu grace period
  45  * @ref: kref pointer of the hard interface
  46  */
  47 void batadv_hardif_release(struct kref *ref)
  48 {
  49         struct batadv_hard_iface *hard_iface;
  50
  51         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  52         dev_put(hard_iface->net_dev);
  53
  54         kfree_rcu(hard_iface, rcu);
  55 }
  56
  57 /**
  58  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  59  * @net_dev: net_device to search for
  60  *
  61  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  62  */
  63 struct batadv_hard_iface *
  64 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  65 {
  66         struct batadv_hard_iface *hard_iface;
  67
  68         rcu_read_lock();
  69         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  70                 if (hard_iface->net_dev == net_dev &&
  71                     kref_get_unless_zero(&hard_iface->refcount))
  72                         goto out;
  73         }
  74
  75         hard_iface = NULL;
  76
  77 out:
  78         rcu_read_unlock();
  79         return hard_iface;
  80 }
  81
  82 /**
  83  * batadv_getlink_net() - return link net namespace (of use fallback)
  84  * @netdev: net_device to check
  85  * @fallback_net: return in case get_link_net is not available for @netdev
  86  *
  87  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  88  */
  89 static struct net *batadv_getlink_net(const struct net_device *netdev,
  90                                       struct net *fallback_net)
  91 {
  92         if (!netdev->rtnl_link_ops)
  93                 return fallback_net;
  94
  95         if (!netdev->rtnl_link_ops->get_link_net)
  96                 return fallback_net;
  97
  98         return netdev->rtnl_link_ops->get_link_net(netdev);
  99 }
 100
 101 /**
 102  * batadv_mutual_parents() - check if two devices are each others parent
 103  * @dev1: 1st net dev
 104  * @net1: 1st devices netns
 105  * @dev2: 2nd net dev
 106  * @net2: 2nd devices netns
 107  *
 108  * veth devices come in pairs and each is the parent of the other!
 109  *
 110  * Return: true if the devices are each others parent, otherwise false
 111  */
 112 static bool batadv_mutual_parents(const struct net_device *dev1,
 113                                   struct net *net1,
 114                                   const struct net_device *dev2,
 115                                   struct net *net2)
 116 {
 117         int dev1_parent_iflink = dev_get_iflink(dev1);
 118         int dev2_parent_iflink = dev_get_iflink(dev2);
 119         const struct net *dev1_parent_net;
 120         const struct net *dev2_parent_net;
 121
 122         dev1_parent_net = batadv_getlink_net(dev1, net1);
 123         dev2_parent_net = batadv_getlink_net(dev2, net2);
 124
 125         if (!dev1_parent_iflink || !dev2_parent_iflink)
 126                 return false;
 127
 128         return (dev1_parent_iflink == dev2->ifindex) &&
 129                (dev2_parent_iflink == dev1->ifindex) &&
 130                net_eq(dev1_parent_net, net2) &&
 131                net_eq(dev2_parent_net, net1);
 132 }
 133
 134 /**
 135  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 136  * @net_dev: the device to check
 137  *
 138  * If the user creates any virtual device on top of a batman-adv interface, it
 139  * is important to prevent this new interface from being used to create a new
 140  * mesh network (this behaviour would lead to a batman-over-batman
 141  * configuration). This function recursively checks all the fathers of the
 142  * device passed as argument looking for a batman-adv soft interface.
 143  *
 144  * Return: true if the device is descendant of a batman-adv mesh interface (or
 145  * if it is a batman-adv interface itself), false otherwise
 146  */
 147 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 148 {
 149         struct net *net = dev_net(net_dev);
 150         struct net_device *parent_dev;
 151         struct net *parent_net;
 152         bool ret;
 153
 154         /* check if this is a batman-adv mesh interface */
 155         if (batadv_softif_is_valid(net_dev))
 156                 return true;
 157
 158         /* no more parents..stop recursion */
 159         if (dev_get_iflink(net_dev) == 0 ||
 160             dev_get_iflink(net_dev) == net_dev->ifindex)
 161                 return false;
 162
 163         parent_net = batadv_getlink_net(net_dev, net);
 164
 165         /* recurse over the parent device */
 166         parent_dev = __dev_get_by_index((struct net *)parent_net,
 167                                         dev_get_iflink(net_dev));
 168         /* if we got a NULL parent_dev there is something broken.. */
 169         if (!parent_dev) {
 170                 pr_err("Cannot find parent device\n");
 171                 return false;
 172         }
 173
 174         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 175                 return false;
 176
 177         ret = batadv_is_on_batman_iface(parent_dev);
 178
 179         return ret;
 180 }
 181
 182 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 183 {
 184         if (net_dev->flags & IFF_LOOPBACK)
 185                 return false;
 186
 187         if (net_dev->type != ARPHRD_ETHER)
 188                 return false;
 189
 190         if (net_dev->addr_len != ETH_ALEN)
 191                 return false;
 192
 193         /* no batman over batman */
 194         if (batadv_is_on_batman_iface(net_dev))
 195                 return false;
 196
 197         return true;
 198 }
 199
 200 /**
 201  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 202  *  interface on top of another 'real' interface
 203  * @netdev: the device to check
 204  *
 205  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 206  * instead of this.
 207  *
 208  * Return: the 'real' net device or the original net device and NULL in case
 209  *  of an error.
 210  */
 211 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 212 {
 213         struct batadv_hard_iface *hard_iface = NULL;
 214         struct net_device *real_netdev = NULL;
 215         struct net *real_net;
 216         struct net *net;
 217         int ifindex;
 218
 219         ASSERT_RTNL();
 220
 221         if (!netdev)
 222                 return NULL;
 223
 224         if (netdev->ifindex == dev_get_iflink(netdev)) {
 225                 dev_hold(netdev);
 226                 return netdev;
 227         }
 228
 229         hard_iface = batadv_hardif_get_by_netdev(netdev);
 230         if (!hard_iface || !hard_iface->soft_iface)
 231                 goto out;
 232
 233         net = dev_net(hard_iface->soft_iface);
 234         ifindex = dev_get_iflink(netdev);
 235         real_net = batadv_getlink_net(netdev, net);
 236         real_netdev = dev_get_by_index(real_net, ifindex);
 237
 238 out:
 239         batadv_hardif_put(hard_iface);
 240         return real_netdev;
 241 }
 242
 243 /**
 244  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 245  *  interface on top of another 'real' interface
 246  * @net_device: the device to check
 247  *
 248  * Return: the 'real' net device or the original net device and NULL in case
 249  *  of an error.
 250  */
 251 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 252 {
 253         struct net_device *real_netdev;
 254
 255         rtnl_lock();
 256         real_netdev = batadv_get_real_netdevice(net_device);
 257         rtnl_unlock();
 258
 259         return real_netdev;
 260 }
 261
 262 /**
 263  * batadv_is_wext_netdev() - check if the given net_device struct is a
 264  *  wext wifi interface
 265  * @net_device: the device to check
 266  *
 267  * Return: true if the net device is a wext wireless device, false
 268  *  otherwise.
 269  */
 270 static bool batadv_is_wext_netdev(struct net_device *net_device)
 271 {
 272         if (!net_device)
 273                 return false;
 274
 275 #ifdef CONFIG_WIRELESS_EXT
 276         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 277          * check for wireless_handlers != NULL
 278          */
 279         if (net_device->wireless_handlers)
 280                 return true;
 281 #endif
 282
 283         return false;
 284 }
 285
 286 /**
 287  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 288  *  cfg80211 wifi interface
 289  * @net_device: the device to check
 290  *
 291  * Return: true if the net device is a cfg80211 wireless device, false
 292  *  otherwise.
 293  */
 294 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 295 {
 296         if (!net_device)
 297                 return false;
 298
 299         /* cfg80211 drivers have to set ieee80211_ptr */
 300         if (net_device->ieee80211_ptr)
 301                 return true;
 302
 303         return false;
 304 }
 305
 306 /**
 307  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 308  * @net_device: the device to check
 309  *
 310  * Return: batadv_hard_iface_wifi_flags flags of the device
 311  */
 312 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 313 {
 314         u32 wifi_flags = 0;
 315         struct net_device *real_netdev;
 316
 317         if (batadv_is_wext_netdev(net_device))
 318                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 319
 320         if (batadv_is_cfg80211_netdev(net_device))
 321                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 322
 323         real_netdev = batadv_get_real_netdevice(net_device);
 324         if (!real_netdev)
 325                 return wifi_flags;
 326
 327         if (real_netdev == net_device)
 328                 goto out;
 329
 330         if (batadv_is_wext_netdev(real_netdev))
 331                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 332
 333         if (batadv_is_cfg80211_netdev(real_netdev))
 334                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 335
 336 out:
 337         dev_put(real_netdev);
 338         return wifi_flags;
 339 }
 340
 341 /**
 342  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 343  *  interface
 344  * @hard_iface: the device to check
 345  *
 346  * Return: true if the net device is a cfg80211 wireless device, false
 347  *  otherwise.
 348  */
 349 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 350 {
 351         u32 allowed_flags = 0;
 352
 353         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 354         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 355
 356         return !!(hard_iface->wifi_flags & allowed_flags);
 357 }
 358
 359 /**
 360  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 361  * @hard_iface: the device to check
 362  *
 363  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 364  */
 365 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 366 {
 367         if (!hard_iface)
 368                 return false;
 369
 370         return hard_iface->wifi_flags != 0;
 371 }
 372
 373 /**
 374  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 375  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 376  * @orig_addr: the originator of this packet
 377  * @orig_neigh: originator address of the forwarder we just got the packet from
 378  *  (NULL if we originated)
 379  *
 380  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 381  *
 382  * Return:
 383  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 384  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 385  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 386  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 387  */
 388 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 389                                u8 *orig_addr, u8 *orig_neigh)
 390 {
 391         struct batadv_hardif_neigh_node *hardif_neigh;
 392         struct hlist_node *first;
 393         int ret = BATADV_HARDIF_BCAST_OK;
 394
 395         rcu_read_lock();
 396
 397         /* 0 neighbors -> no (re)broadcast */
 398         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 399         if (!first) {
 400                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 401                 goto out;
 402         }
 403
 404         /* >1 neighbors -> (re)broadcast */
 405         if (rcu_dereference(hlist_next_rcu(first)))
 406                 goto out;
 407
 408         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 409                                    list);
 410
 411         /* 1 neighbor, is the originator -> no rebroadcast */
 412         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 413                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 414         /* 1 neighbor, is the one we received from -> no rebroadcast */
 415         } else if (orig_neigh &&
 416                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 417                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 418         }
 419
 420 out:
 421         rcu_read_unlock();
 422         return ret;
 423 }
 424
 425 static struct batadv_hard_iface *
 426 batadv_hardif_get_active(const struct net_device *soft_iface)
 427 {
 428         struct batadv_hard_iface *hard_iface;
 429
 430         rcu_read_lock();
 431         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 432                 if (hard_iface->soft_iface != soft_iface)
 433                         continue;
 434
 435                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 436                     kref_get_unless_zero(&hard_iface->refcount))
 437                         goto out;
 438         }
 439
 440         hard_iface = NULL;
 441
 442 out:
 443         rcu_read_unlock();
 444         return hard_iface;
 445 }
 446
 447 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 448                                           struct batadv_hard_iface *oldif)
 449 {
 450         struct batadv_hard_iface *primary_if;
 451
 452         primary_if = batadv_primary_if_get_selected(bat_priv);
 453         if (!primary_if)
 454                 goto out;
 455
 456         batadv_dat_init_own_addr(bat_priv, primary_if);
 457         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 458 out:
 459         batadv_hardif_put(primary_if);
 460 }
 461
 462 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 463                                      struct batadv_hard_iface *new_hard_iface)
 464 {
 465         struct batadv_hard_iface *curr_hard_iface;
 466
 467         ASSERT_RTNL();
 468
 469         if (new_hard_iface)
 470                 kref_get(&new_hard_iface->refcount);
 471
 472         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 473                                               new_hard_iface, 1);
 474
 475         if (!new_hard_iface)
 476                 goto out;
 477
 478         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 479         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 480
 481 out:
 482         batadv_hardif_put(curr_hard_iface);
 483 }
 484
 485 static bool
 486 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 487 {
 488         if (hard_iface->net_dev->flags & IFF_UP)
 489                 return true;
 490
 491         return false;
 492 }
 493
 494 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 495 {
 496         const struct batadv_hard_iface *hard_iface;
 497
 498         rcu_read_lock();
 499         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 500                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 501                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 502                         continue;
 503
 504                 if (hard_iface->net_dev == net_dev)
 505                         continue;
 506
 507                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 508                                         net_dev->dev_addr))
 509                         continue;
 510
 511                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 512                         net_dev->dev_addr, hard_iface->net_dev->name);
 513                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 514         }
 515         rcu_read_unlock();
 516 }
 517
 518 /**
 519  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 520  * @soft_iface: netdev struct of the mesh interface
 521  */
 522 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 523 {
 524         const struct batadv_hard_iface *hard_iface;
 525         unsigned short lower_header_len = ETH_HLEN;
 526         unsigned short lower_headroom = 0;
 527         unsigned short lower_tailroom = 0;
 528         unsigned short needed_headroom;
 529
 530         rcu_read_lock();
 531         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 532                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 533                         continue;
 534
 535                 if (hard_iface->soft_iface != soft_iface)
 536                         continue;
 537
 538                 lower_header_len = max_t(unsigned short, lower_header_len,
 539                                          hard_iface->net_dev->hard_header_len);
 540
 541                 lower_headroom = max_t(unsigned short, lower_headroom,
 542                                        hard_iface->net_dev->needed_headroom);
 543
 544                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 545                                        hard_iface->net_dev->needed_tailroom);
 546         }
 547         rcu_read_unlock();
 548
 549         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 550         needed_headroom += batadv_max_header_len();
 551
 552         /* fragmentation headers don't strip the unicast/... header */
 553         needed_headroom += sizeof(struct batadv_frag_packet);
 554
 555         soft_iface->needed_headroom = needed_headroom;
 556         soft_iface->needed_tailroom = lower_tailroom;
 557 }
 558
 559 /**
 560  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 561  * @soft_iface: netdev struct of the soft interface
 562  *
 563  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 564  *  slave interfaces)
 565  */
 566 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 567 {
 568         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 569         const struct batadv_hard_iface *hard_iface;
 570         int min_mtu = INT_MAX;
 571
 572         rcu_read_lock();
 573         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 574                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 575                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 576                         continue;
 577
 578                 if (hard_iface->soft_iface != soft_iface)
 579                         continue;
 580
 581                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 582         }
 583         rcu_read_unlock();
 584
 585         if (atomic_read(&bat_priv->fragmentation) == 0)
 586                 goto out;
 587
 588         /* with fragmentation enabled the maximum size of internally generated
 589          * packets such as translation table exchanges or tvlv containers, etc
 590          * has to be calculated
 591          */
 592         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 593         min_mtu -= sizeof(struct batadv_frag_packet);
 594         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 595
 596 out:
 597         /* report to the other components the maximum amount of bytes that
 598          * batman-adv can send over the wire (without considering the payload
 599          * overhead). For example, this value is used by TT to compute the
 600          * maximum local table size
 601          */
 602         atomic_set(&bat_priv->packet_size_max, min_mtu);
 603
 604         /* the real soft-interface MTU is computed by removing the payload
 605          * overhead from the maximum amount of bytes that was just computed.
 606          *
 607          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 608          */
 609         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 610 }
 611
 612 /**
 613  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 614  *  MTU appeared
 615  * @soft_iface: netdev struct of the soft interface
 616  */
 617 void batadv_update_min_mtu(struct net_device *soft_iface)
 618 {
 619         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 620
 621         /* Check if the local translate table should be cleaned up to match a
 622          * new (and smaller) MTU.
 623          */
 624         batadv_tt_local_resize_to_mtu(soft_iface);
 625 }
 626
 627 static void
 628 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 629 {
 630         struct batadv_priv *bat_priv;
 631         struct batadv_hard_iface *primary_if = NULL;
 632
 633         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 634                 goto out;
 635
 636         bat_priv = netdev_priv(hard_iface->soft_iface);
 637
 638         bat_priv->algo_ops->iface.update_mac(hard_iface);
 639         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 640
 641         /* the first active interface becomes our primary interface or
 642          * the next active interface after the old primary interface was removed
 643          */
 644         primary_if = batadv_primary_if_get_selected(bat_priv);
 645         if (!primary_if)
 646                 batadv_primary_if_select(bat_priv, hard_iface);
 647
 648         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 649                     hard_iface->net_dev->name);
 650
 651         batadv_update_min_mtu(hard_iface->soft_iface);
 652
 653         if (bat_priv->algo_ops->iface.activate)
 654                 bat_priv->algo_ops->iface.activate(hard_iface);
 655
 656 out:
 657         batadv_hardif_put(primary_if);
 658 }
 659
 660 static void
 661 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 662 {
 663         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 664             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 665                 return;
 666
 667         hard_iface->if_status = BATADV_IF_INACTIVE;
 668
 669         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 670                     hard_iface->net_dev->name);
 671
 672         batadv_update_min_mtu(hard_iface->soft_iface);
 673 }
 674
 675 /**
 676  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 677  * @hard_iface: hard interface to add to soft interface
 678  * @soft_iface: netdev struct of the mesh interface
 679  *
 680  * Return: 0 on success or negative error number in case of failure
 681  */
 682 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 683                                    struct net_device *soft_iface)
 684 {
 685         struct batadv_priv *bat_priv;
 686         __be16 ethertype = htons(ETH_P_BATMAN);
 687         int max_header_len = batadv_max_header_len();
 688         int ret;
 689
 690         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 691                 goto out;
 692
 693         kref_get(&hard_iface->refcount);
 694
 695         dev_hold(soft_iface);
 696         hard_iface->soft_iface = soft_iface;
 697         bat_priv = netdev_priv(hard_iface->soft_iface);
 698
 699         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 700                                            soft_iface, NULL, NULL, NULL);
 701         if (ret)
 702                 goto err_dev;
 703
 704         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 705         if (ret < 0)
 706                 goto err_upper;
 707
 708         hard_iface->if_status = BATADV_IF_INACTIVE;
 709
 710         kref_get(&hard_iface->refcount);
 711         hard_iface->batman_adv_ptype.type = ethertype;
 712         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 713         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 714         dev_add_pack(&hard_iface->batman_adv_ptype);
 715
 716         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 717                     hard_iface->net_dev->name);
 718
 719         if (atomic_read(&bat_priv->fragmentation) &&
 720             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 721                 batadv_info(hard_iface->soft_iface,
 722                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %i would solve the problem.\n",
 723                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 724                             ETH_DATA_LEN + max_header_len);
 725
 726         if (!atomic_read(&bat_priv->fragmentation) &&
 727             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 728                 batadv_info(hard_iface->soft_iface,
 729                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n",
 730                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 731                             ETH_DATA_LEN + max_header_len);
 732
 733         if (batadv_hardif_is_iface_up(hard_iface))
 734                 batadv_hardif_activate_interface(hard_iface);
 735         else
 736                 batadv_err(hard_iface->soft_iface,
 737                            "Not using interface %s (retrying later): interface not active\n",
 738                            hard_iface->net_dev->name);
 739
 740         batadv_hardif_recalc_extra_skbroom(soft_iface);
 741
 742         if (bat_priv->algo_ops->iface.enabled)
 743                 bat_priv->algo_ops->iface.enabled(hard_iface);
 744
 745 out:
 746         return 0;
 747
 748 err_upper:
 749         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 750 err_dev:
 751         hard_iface->soft_iface = NULL;
 752         dev_put(soft_iface);
 753         batadv_hardif_put(hard_iface);
 754         return ret;
 755 }
 756
 757 /**
 758  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 759  * @soft_iface: soft interface to check
 760  *
 761  * This function is only using RCU for locking - the result can therefore be
 762  * off when another function is modifying the list at the same time. The
 763  * caller can use the rtnl_lock to make sure that the count is accurate.
 764  *
 765  * Return: number of connected/enslaved hard interfaces
 766  */
 767 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 768 {
 769         struct batadv_hard_iface *hard_iface;
 770         size_t count = 0;
 771
 772         rcu_read_lock();
 773         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 774                 if (hard_iface->soft_iface != soft_iface)
 775                         continue;
 776
 777                 count++;
 778         }
 779         rcu_read_unlock();
 780
 781         return count;
 782 }
 783
 784 /**
 785  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 786  * @hard_iface: hard interface to be removed
 787  */
 788 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
 789 {
 790         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 791         struct batadv_hard_iface *primary_if = NULL;
 792
 793         batadv_hardif_deactivate_interface(hard_iface);
 794
 795         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 796                 goto out;
 797
 798         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 799                     hard_iface->net_dev->name);
 800         dev_remove_pack(&hard_iface->batman_adv_ptype);
 801         batadv_hardif_put(hard_iface);
 802
 803         primary_if = batadv_primary_if_get_selected(bat_priv);
 804         if (hard_iface == primary_if) {
 805                 struct batadv_hard_iface *new_if;
 806
 807                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 808                 batadv_primary_if_select(bat_priv, new_if);
 809
 810                 batadv_hardif_put(new_if);
 811         }
 812
 813         bat_priv->algo_ops->iface.disable(hard_iface);
 814         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 815
 816         /* delete all references to this hard_iface */
 817         batadv_purge_orig_ref(bat_priv);
 818         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 819         dev_put(hard_iface->soft_iface);
 820
 821         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 822         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 823
 824         /* nobody uses this interface anymore */
 825         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1)
 826                 batadv_gw_check_client_stop(bat_priv);
 827
 828         hard_iface->soft_iface = NULL;
 829         batadv_hardif_put(hard_iface);
 830
 831 out:
 832         batadv_hardif_put(primary_if);
 833 }
 834
 835 static struct batadv_hard_iface *
 836 batadv_hardif_add_interface(struct net_device *net_dev)
 837 {
 838         struct batadv_hard_iface *hard_iface;
 839
 840         ASSERT_RTNL();
 841
 842         if (!batadv_is_valid_iface(net_dev))
 843                 goto out;
 844
 845         dev_hold(net_dev);
 846
 847         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 848         if (!hard_iface)
 849                 goto release_dev;
 850
 851         hard_iface->net_dev = net_dev;
 852         hard_iface->soft_iface = NULL;
 853         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 854
 855         INIT_LIST_HEAD(&hard_iface->list);
 856         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 857
 858         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 859         spin_lock_init(&hard_iface->neigh_list_lock);
 860         kref_init(&hard_iface->refcount);
 861
 862         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 863         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 864         if (batadv_is_wifi_hardif(hard_iface))
 865                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 866
 867         atomic_set(&hard_iface->hop_penalty, 0);
 868
 869         batadv_v_hardif_init(hard_iface);
 870
 871         batadv_check_known_mac_addr(hard_iface->net_dev);
 872         kref_get(&hard_iface->refcount);
 873         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 874         batadv_hardif_generation++;
 875
 876         return hard_iface;
 877
 878 release_dev:
 879         dev_put(net_dev);
 880 out:
 881         return NULL;
 882 }
 883
 884 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 885 {
 886         ASSERT_RTNL();
 887
 888         /* first deactivate interface */
 889         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 890                 batadv_hardif_disable_interface(hard_iface);
 891
 892         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 893                 return;
 894
 895         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 896         batadv_hardif_put(hard_iface);
 897 }
 898
 899 /**
 900  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 901  * @event: NETDEV_* event to handle
 902  * @net_dev: net_device which generated an event
 903  *
 904  * Return: NOTIFY_* result
 905  */
 906 static int batadv_hard_if_event_softif(unsigned long event,
 907                                        struct net_device *net_dev)
 908 {
 909         struct batadv_priv *bat_priv;
 910
 911         switch (event) {
 912         case NETDEV_REGISTER:
 913                 bat_priv = netdev_priv(net_dev);
 914                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 915                 break;
 916         }
 917
 918         return NOTIFY_DONE;
 919 }
 920
 921 static int batadv_hard_if_event(struct notifier_block *this,
 922                                 unsigned long event, void *ptr)
 923 {
 924         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 925         struct batadv_hard_iface *hard_iface;
 926         struct batadv_hard_iface *primary_if = NULL;
 927         struct batadv_priv *bat_priv;
 928
 929         if (batadv_softif_is_valid(net_dev))
 930                 return batadv_hard_if_event_softif(event, net_dev);
 931
 932         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 933         if (!hard_iface && (event == NETDEV_REGISTER ||
 934                             event == NETDEV_POST_TYPE_CHANGE))
 935                 hard_iface = batadv_hardif_add_interface(net_dev);
 936
 937         if (!hard_iface)
 938                 goto out;
 939
 940         switch (event) {
 941         case NETDEV_UP:
 942                 batadv_hardif_activate_interface(hard_iface);
 943                 break;
 944         case NETDEV_GOING_DOWN:
 945         case NETDEV_DOWN:
 946                 batadv_hardif_deactivate_interface(hard_iface);
 947                 break;
 948         case NETDEV_UNREGISTER:
 949         case NETDEV_PRE_TYPE_CHANGE:
 950                 list_del_rcu(&hard_iface->list);
 951                 batadv_hardif_generation++;
 952
 953                 batadv_hardif_remove_interface(hard_iface);
 954                 break;
 955         case NETDEV_CHANGEMTU:
 956                 if (hard_iface->soft_iface)
 957                         batadv_update_min_mtu(hard_iface->soft_iface);
 958                 break;
 959         case NETDEV_CHANGEADDR:
 960                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 961                         goto hardif_put;
 962
 963                 batadv_check_known_mac_addr(hard_iface->net_dev);
 964
 965                 bat_priv = netdev_priv(hard_iface->soft_iface);
 966                 bat_priv->algo_ops->iface.update_mac(hard_iface);
 967
 968                 primary_if = batadv_primary_if_get_selected(bat_priv);
 969                 if (!primary_if)
 970                         goto hardif_put;
 971
 972                 if (hard_iface == primary_if)
 973                         batadv_primary_if_update_addr(bat_priv, NULL);
 974                 break;
 975         case NETDEV_CHANGEUPPER:
 976                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 977                 if (batadv_is_wifi_hardif(hard_iface))
 978                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 979                 break;
 980         default:
 981                 break;
 982         }
 983
 984 hardif_put:
 985         batadv_hardif_put(hard_iface);
 986 out:
 987         batadv_hardif_put(primary_if);
 988         return NOTIFY_DONE;
 989 }
 990
 991 struct notifier_block batadv_hard_if_notifier = {
 992         .notifier_call = batadv_hard_if_event,
 993 };