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/compiler.h>
  13 #include <linux/container_of.h>
  14 #include <linux/errno.h>
  15 #include <linux/gfp.h>
  16 #include <linux/if.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/if_ether.h>
  19 #include <linux/kref.h>
  20 #include <linux/limits.h>
  21 #include <linux/list.h>
  22 #include <linux/minmax.h>
  23 #include <linux/mutex.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/printk.h>
  26 #include <linux/rculist.h>
  27 #include <linux/rtnetlink.h>
  28 #include <linux/slab.h>
  29 #include <linux/spinlock.h>
  30 #include <net/net_namespace.h>
  31 #include <net/rtnetlink.h>
  32 #include <uapi/linux/batadv_packet.h>
  33
  34 #include "bat_v.h"
  35 #include "bridge_loop_avoidance.h"
  36 #include "distributed-arp-table.h"
  37 #include "gateway_client.h"
  38 #include "log.h"
  39 #include "mesh-interface.h"
  40 #include "originator.h"
  41 #include "send.h"
  42 #include "translation-table.h"
  43
  44 /**
  45  * batadv_hardif_release() - release hard interface from lists and queue for
  46  *  free after rcu grace period
  47  * @ref: kref pointer of the hard interface
  48  */
  49 void batadv_hardif_release(struct kref *ref)
  50 {
  51         struct batadv_hard_iface *hard_iface;
  52
  53         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  54         netdev_put(hard_iface->net_dev, &hard_iface->dev_tracker);
  55
  56         kfree_rcu(hard_iface, rcu);
  57 }
  58
  59 /**
  60  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  61  * @net_dev: net_device to search for
  62  *
  63  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  64  */
  65 struct batadv_hard_iface *
  66 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  67 {
  68         struct batadv_hard_iface *hard_iface;
  69
  70         rcu_read_lock();
  71         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  72                 if (hard_iface->net_dev == net_dev &&
  73                     kref_get_unless_zero(&hard_iface->refcount))
  74                         goto out;
  75         }
  76
  77         hard_iface = NULL;
  78
  79 out:
  80         rcu_read_unlock();
  81         return hard_iface;
  82 }
  83
  84 /**
  85  * batadv_getlink_net() - return link net namespace (of use fallback)
  86  * @netdev: net_device to check
  87  * @fallback_net: return in case get_link_net is not available for @netdev
  88  *
  89  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  90  */
  91 static struct net *batadv_getlink_net(const struct net_device *netdev,
  92                                       struct net *fallback_net)
  93 {
  94         if (!netdev->rtnl_link_ops)
  95                 return fallback_net;
  96
  97         if (!netdev->rtnl_link_ops->get_link_net)
  98                 return fallback_net;
  99
 100         return netdev->rtnl_link_ops->get_link_net(netdev);
 101 }
 102
 103 /**
 104  * batadv_mutual_parents() - check if two devices are each others parent
 105  * @dev1: 1st net dev
 106  * @net1: 1st devices netns
 107  * @dev2: 2nd net dev
 108  * @net2: 2nd devices netns
 109  *
 110  * veth devices come in pairs and each is the parent of the other!
 111  *
 112  * Return: true if the devices are each others parent, otherwise false
 113  */
 114 static bool batadv_mutual_parents(const struct net_device *dev1,
 115                                   struct net *net1,
 116                                   const struct net_device *dev2,
 117                                   struct net *net2)
 118 {
 119         int dev1_parent_iflink = dev_get_iflink(dev1);
 120         int dev2_parent_iflink = dev_get_iflink(dev2);
 121         const struct net *dev1_parent_net;
 122         const struct net *dev2_parent_net;
 123
 124         dev1_parent_net = batadv_getlink_net(dev1, net1);
 125         dev2_parent_net = batadv_getlink_net(dev2, net2);
 126
 127         if (!dev1_parent_iflink || !dev2_parent_iflink)
 128                 return false;
 129
 130         return (dev1_parent_iflink == dev2->ifindex) &&
 131                (dev2_parent_iflink == dev1->ifindex) &&
 132                net_eq(dev1_parent_net, net2) &&
 133                net_eq(dev2_parent_net, net1);
 134 }
 135
 136 /**
 137  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 138  * @net_dev: the device to check
 139  *
 140  * If the user creates any virtual device on top of a batman-adv interface, it
 141  * is important to prevent this new interface from being used to create a new
 142  * mesh network (this behaviour would lead to a batman-over-batman
 143  * configuration). This function recursively checks all the fathers of the
 144  * device passed as argument looking for a batman-adv mesh interface.
 145  *
 146  * Return: true if the device is descendant of a batman-adv mesh interface (or
 147  * if it is a batman-adv interface itself), false otherwise
 148  */
 149 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 150 {
 151         struct net *net = dev_net(net_dev);
 152         struct net_device *parent_dev;
 153         struct net *parent_net;
 154         int iflink;
 155         bool ret;
 156
 157         /* check if this is a batman-adv mesh interface */
 158         if (batadv_meshif_is_valid(net_dev))
 159                 return true;
 160
 161         iflink = dev_get_iflink(net_dev);
 162         if (iflink == 0)
 163                 return false;
 164
 165         parent_net = batadv_getlink_net(net_dev, net);
 166
 167         /* iflink to itself, most likely physical device */
 168         if (net == parent_net && iflink == net_dev->ifindex)
 169                 return false;
 170
 171         /* recurse over the parent device */
 172         parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
 173         if (!parent_dev) {
 174                 pr_warn("Cannot find parent device. Skipping batadv-on-batadv check for %s\n",
 175                         net_dev->name);
 176                 return false;
 177         }
 178
 179         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 180                 return false;
 181
 182         ret = batadv_is_on_batman_iface(parent_dev);
 183
 184         return ret;
 185 }
 186
 187 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 188 {
 189         if (net_dev->flags & IFF_LOOPBACK)
 190                 return false;
 191
 192         if (net_dev->type != ARPHRD_ETHER)
 193                 return false;
 194
 195         if (net_dev->addr_len != ETH_ALEN)
 196                 return false;
 197
 198         /* no batman over batman */
 199         if (batadv_is_on_batman_iface(net_dev))
 200                 return false;
 201
 202         return true;
 203 }
 204
 205 /**
 206  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 207  *  interface on top of another 'real' interface
 208  * @netdev: the device to check
 209  *
 210  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 211  * instead of this.
 212  *
 213  * Return: the 'real' net device or the original net device and NULL in case
 214  *  of an error.
 215  */
 216 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 217 {
 218         struct batadv_hard_iface *hard_iface = NULL;
 219         struct net_device *real_netdev = NULL;
 220         struct net *real_net;
 221         struct net *net;
 222         int iflink;
 223
 224         ASSERT_RTNL();
 225
 226         if (!netdev)
 227                 return NULL;
 228
 229         iflink = dev_get_iflink(netdev);
 230         if (iflink == 0) {
 231                 dev_hold(netdev);
 232                 return netdev;
 233         }
 234
 235         hard_iface = batadv_hardif_get_by_netdev(netdev);
 236         if (!hard_iface || !hard_iface->mesh_iface)
 237                 goto out;
 238
 239         net = dev_net(hard_iface->mesh_iface);
 240         real_net = batadv_getlink_net(netdev, net);
 241
 242         /* iflink to itself, most likely physical device */
 243         if (net == real_net && netdev->ifindex == iflink) {
 244                 real_netdev = netdev;
 245                 dev_hold(real_netdev);
 246                 goto out;
 247         }
 248
 249         real_netdev = dev_get_by_index(real_net, iflink);
 250
 251 out:
 252         batadv_hardif_put(hard_iface);
 253         return real_netdev;
 254 }
 255
 256 /**
 257  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 258  *  interface on top of another 'real' interface
 259  * @net_device: the device to check
 260  *
 261  * Return: the 'real' net device or the original net device and NULL in case
 262  *  of an error.
 263  */
 264 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 265 {
 266         struct net_device *real_netdev;
 267
 268         rtnl_lock();
 269         real_netdev = batadv_get_real_netdevice(net_device);
 270         rtnl_unlock();
 271
 272         return real_netdev;
 273 }
 274
 275 /**
 276  * batadv_is_wext_netdev() - check if the given net_device struct is a
 277  *  wext wifi interface
 278  * @net_device: the device to check
 279  *
 280  * Return: true if the net device is a wext wireless device, false
 281  *  otherwise.
 282  */
 283 static bool batadv_is_wext_netdev(struct net_device *net_device)
 284 {
 285         if (!net_device)
 286                 return false;
 287
 288 #ifdef CONFIG_WIRELESS_EXT
 289         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 290          * check for wireless_handlers != NULL
 291          */
 292         if (net_device->wireless_handlers)
 293                 return true;
 294 #endif
 295
 296         return false;
 297 }
 298
 299 /**
 300  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 301  *  cfg80211 wifi interface
 302  * @net_device: the device to check
 303  *
 304  * Return: true if the net device is a cfg80211 wireless device, false
 305  *  otherwise.
 306  */
 307 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 308 {
 309         if (!net_device)
 310                 return false;
 311
 312 #if IS_ENABLED(CONFIG_CFG80211)
 313         /* cfg80211 drivers have to set ieee80211_ptr */
 314         if (net_device->ieee80211_ptr)
 315                 return true;
 316 #endif
 317
 318         return false;
 319 }
 320
 321 /**
 322  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 323  * @net_device: the device to check
 324  *
 325  * Return: batadv_hard_iface_wifi_flags flags of the device
 326  */
 327 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 328 {
 329         u32 wifi_flags = 0;
 330         struct net_device *real_netdev;
 331
 332         if (batadv_is_wext_netdev(net_device))
 333                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 334
 335         if (batadv_is_cfg80211_netdev(net_device))
 336                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 337
 338         real_netdev = batadv_get_real_netdevice(net_device);
 339         if (!real_netdev)
 340                 return wifi_flags;
 341
 342         if (real_netdev == net_device)
 343                 goto out;
 344
 345         if (batadv_is_wext_netdev(real_netdev))
 346                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 347
 348         if (batadv_is_cfg80211_netdev(real_netdev))
 349                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 350
 351 out:
 352         dev_put(real_netdev);
 353         return wifi_flags;
 354 }
 355
 356 /**
 357  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 358  *  interface
 359  * @hard_iface: the device to check
 360  *
 361  * Return: true if the net device is a cfg80211 wireless device, false
 362  *  otherwise.
 363  */
 364 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 365 {
 366         u32 allowed_flags = 0;
 367
 368         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 369         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 370
 371         return !!(hard_iface->wifi_flags & allowed_flags);
 372 }
 373
 374 /**
 375  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 376  * @hard_iface: the device to check
 377  *
 378  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 379  */
 380 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 381 {
 382         if (!hard_iface)
 383                 return false;
 384
 385         return hard_iface->wifi_flags != 0;
 386 }
 387
 388 /**
 389  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 390  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 391  * @orig_addr: the originator of this packet
 392  * @orig_neigh: originator address of the forwarder we just got the packet from
 393  *  (NULL if we originated)
 394  *
 395  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 396  *
 397  * Return:
 398  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 399  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 400  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 401  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 402  */
 403 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 404                                u8 *orig_addr, u8 *orig_neigh)
 405 {
 406         struct batadv_hardif_neigh_node *hardif_neigh;
 407         struct hlist_node *first;
 408         int ret = BATADV_HARDIF_BCAST_OK;
 409
 410         rcu_read_lock();
 411
 412         /* 0 neighbors -> no (re)broadcast */
 413         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 414         if (!first) {
 415                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 416                 goto out;
 417         }
 418
 419         /* >1 neighbors -> (re)broadcast */
 420         if (rcu_dereference(hlist_next_rcu(first)))
 421                 goto out;
 422
 423         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 424                                    list);
 425
 426         /* 1 neighbor, is the originator -> no rebroadcast */
 427         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 428                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 429         /* 1 neighbor, is the one we received from -> no rebroadcast */
 430         } else if (orig_neigh &&
 431                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 432                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 433         }
 434
 435 out:
 436         rcu_read_unlock();
 437         return ret;
 438 }
 439
 440 static struct batadv_hard_iface *
 441 batadv_hardif_get_active(const struct net_device *mesh_iface)
 442 {
 443         struct batadv_hard_iface *hard_iface;
 444
 445         rcu_read_lock();
 446         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 447                 if (hard_iface->mesh_iface != mesh_iface)
 448                         continue;
 449
 450                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 451                     kref_get_unless_zero(&hard_iface->refcount))
 452                         goto out;
 453         }
 454
 455         hard_iface = NULL;
 456
 457 out:
 458         rcu_read_unlock();
 459         return hard_iface;
 460 }
 461
 462 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 463                                           struct batadv_hard_iface *oldif)
 464 {
 465         struct batadv_hard_iface *primary_if;
 466
 467         primary_if = batadv_primary_if_get_selected(bat_priv);
 468         if (!primary_if)
 469                 goto out;
 470
 471         batadv_dat_init_own_addr(bat_priv, primary_if);
 472         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 473 out:
 474         batadv_hardif_put(primary_if);
 475 }
 476
 477 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 478                                      struct batadv_hard_iface *new_hard_iface)
 479 {
 480         struct batadv_hard_iface *curr_hard_iface;
 481
 482         ASSERT_RTNL();
 483
 484         if (new_hard_iface)
 485                 kref_get(&new_hard_iface->refcount);
 486
 487         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 488                                               new_hard_iface, 1);
 489
 490         if (!new_hard_iface)
 491                 goto out;
 492
 493         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 494         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 495
 496 out:
 497         batadv_hardif_put(curr_hard_iface);
 498 }
 499
 500 static bool
 501 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 502 {
 503         if (hard_iface->net_dev->flags & IFF_UP)
 504                 return true;
 505
 506         return false;
 507 }
 508
 509 static void batadv_check_known_mac_addr(const struct batadv_hard_iface *hard_iface)
 510 {
 511         const struct net_device *mesh_iface = hard_iface->mesh_iface;
 512         const struct batadv_hard_iface *tmp_hard_iface;
 513
 514         if (!mesh_iface)
 515                 return;
 516
 517         list_for_each_entry(tmp_hard_iface, &batadv_hardif_list, list) {
 518                 if (tmp_hard_iface == hard_iface)
 519                         continue;
 520
 521                 if (tmp_hard_iface->mesh_iface != mesh_iface)
 522                         continue;
 523
 524                 if (tmp_hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 525                         continue;
 526
 527                 if (!batadv_compare_eth(tmp_hard_iface->net_dev->dev_addr,
 528                                         hard_iface->net_dev->dev_addr))
 529                         continue;
 530
 531                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 532                         hard_iface->net_dev->dev_addr, tmp_hard_iface->net_dev->name);
 533                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 534         }
 535 }
 536
 537 /**
 538  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 539  * @mesh_iface: netdev struct of the mesh interface
 540  */
 541 static void batadv_hardif_recalc_extra_skbroom(struct net_device *mesh_iface)
 542 {
 543         const struct batadv_hard_iface *hard_iface;
 544         unsigned short lower_header_len = ETH_HLEN;
 545         unsigned short lower_headroom = 0;
 546         unsigned short lower_tailroom = 0;
 547         unsigned short needed_headroom;
 548
 549         rcu_read_lock();
 550         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 551                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 552                         continue;
 553
 554                 if (hard_iface->mesh_iface != mesh_iface)
 555                         continue;
 556
 557                 lower_header_len = max_t(unsigned short, lower_header_len,
 558                                          hard_iface->net_dev->hard_header_len);
 559
 560                 lower_headroom = max_t(unsigned short, lower_headroom,
 561                                        hard_iface->net_dev->needed_headroom);
 562
 563                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 564                                        hard_iface->net_dev->needed_tailroom);
 565         }
 566         rcu_read_unlock();
 567
 568         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 569         needed_headroom += batadv_max_header_len();
 570
 571         /* fragmentation headers don't strip the unicast/... header */
 572         needed_headroom += sizeof(struct batadv_frag_packet);
 573
 574         mesh_iface->needed_headroom = needed_headroom;
 575         mesh_iface->needed_tailroom = lower_tailroom;
 576 }
 577
 578 /**
 579  * batadv_hardif_min_mtu() - Calculate maximum MTU for mesh interface
 580  * @mesh_iface: netdev struct of the mesh interface
 581  *
 582  * Return: MTU for the mesh-interface (limited by the minimal MTU of all active
 583  *  slave interfaces)
 584  */
 585 int batadv_hardif_min_mtu(struct net_device *mesh_iface)
 586 {
 587         struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
 588         const struct batadv_hard_iface *hard_iface;
 589         int min_mtu = INT_MAX;
 590
 591         rcu_read_lock();
 592         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 593                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 594                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 595                         continue;
 596
 597                 if (hard_iface->mesh_iface != mesh_iface)
 598                         continue;
 599
 600                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 601         }
 602         rcu_read_unlock();
 603
 604         if (atomic_read(&bat_priv->fragmentation) == 0)
 605                 goto out;
 606
 607         /* with fragmentation enabled the maximum size of internally generated
 608          * packets such as translation table exchanges or tvlv containers, etc
 609          * has to be calculated
 610          */
 611         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 612         min_mtu -= sizeof(struct batadv_frag_packet);
 613         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 614
 615 out:
 616         /* report to the other components the maximum amount of bytes that
 617          * batman-adv can send over the wire (without considering the payload
 618          * overhead). For example, this value is used by TT to compute the
 619          * maximum local table size
 620          */
 621         atomic_set(&bat_priv->packet_size_max, min_mtu);
 622
 623         /* the real mesh-interface MTU is computed by removing the payload
 624          * overhead from the maximum amount of bytes that was just computed.
 625          */
 626         return min_t(int, min_mtu - batadv_max_header_len(), BATADV_MAX_MTU);
 627 }
 628
 629 /**
 630  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 631  *  MTU appeared
 632  * @mesh_iface: netdev struct of the mesh interface
 633  */
 634 void batadv_update_min_mtu(struct net_device *mesh_iface)
 635 {
 636         struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
 637         int limit_mtu;
 638         int mtu;
 639
 640         mtu = batadv_hardif_min_mtu(mesh_iface);
 641
 642         if (bat_priv->mtu_set_by_user)
 643                 limit_mtu = bat_priv->mtu_set_by_user;
 644         else
 645                 limit_mtu = ETH_DATA_LEN;
 646
 647         mtu = min(mtu, limit_mtu);
 648         dev_set_mtu(mesh_iface, mtu);
 649
 650         /* Check if the local translate table should be cleaned up to match a
 651          * new (and smaller) MTU.
 652          */
 653         batadv_tt_local_resize_to_mtu(mesh_iface);
 654 }
 655
 656 static void
 657 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 658 {
 659         struct batadv_priv *bat_priv;
 660         struct batadv_hard_iface *primary_if = NULL;
 661
 662         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 663                 goto out;
 664
 665         bat_priv = netdev_priv(hard_iface->mesh_iface);
 666
 667         bat_priv->algo_ops->iface.update_mac(hard_iface);
 668         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 669
 670         /* the first active interface becomes our primary interface or
 671          * the next active interface after the old primary interface was removed
 672          */
 673         primary_if = batadv_primary_if_get_selected(bat_priv);
 674         if (!primary_if)
 675                 batadv_primary_if_select(bat_priv, hard_iface);
 676
 677         batadv_info(hard_iface->mesh_iface, "Interface activated: %s\n",
 678                     hard_iface->net_dev->name);
 679
 680         batadv_update_min_mtu(hard_iface->mesh_iface);
 681
 682         if (bat_priv->algo_ops->iface.activate)
 683                 bat_priv->algo_ops->iface.activate(hard_iface);
 684
 685 out:
 686         batadv_hardif_put(primary_if);
 687 }
 688
 689 static void
 690 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 691 {
 692         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 693             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 694                 return;
 695
 696         hard_iface->if_status = BATADV_IF_INACTIVE;
 697
 698         batadv_info(hard_iface->mesh_iface, "Interface deactivated: %s\n",
 699                     hard_iface->net_dev->name);
 700
 701         batadv_update_min_mtu(hard_iface->mesh_iface);
 702 }
 703
 704 /**
 705  * batadv_hardif_enable_interface() - Enslave hard interface to mesh interface
 706  * @hard_iface: hard interface to add to mesh interface
 707  * @mesh_iface: netdev struct of the mesh interface
 708  *
 709  * Return: 0 on success or negative error number in case of failure
 710  */
 711 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 712                                    struct net_device *mesh_iface)
 713 {
 714         struct batadv_priv *bat_priv;
 715         __be16 ethertype = htons(ETH_P_BATMAN);
 716         int max_header_len = batadv_max_header_len();
 717         unsigned int required_mtu;
 718         unsigned int hardif_mtu;
 719         int ret;
 720
 721         hardif_mtu = READ_ONCE(hard_iface->net_dev->mtu);
 722         required_mtu = READ_ONCE(mesh_iface->mtu) + max_header_len;
 723
 724         if (hardif_mtu < ETH_MIN_MTU + max_header_len)
 725                 return -EINVAL;
 726
 727         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 728                 goto out;
 729
 730         kref_get(&hard_iface->refcount);
 731
 732         netdev_hold(mesh_iface, &hard_iface->meshif_dev_tracker, GFP_ATOMIC);
 733         hard_iface->mesh_iface = mesh_iface;
 734         bat_priv = netdev_priv(hard_iface->mesh_iface);
 735
 736         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 737                                            mesh_iface, NULL, NULL, NULL);
 738         if (ret)
 739                 goto err_dev;
 740
 741         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 742         if (ret < 0)
 743                 goto err_upper;
 744
 745         hard_iface->if_status = BATADV_IF_INACTIVE;
 746
 747         kref_get(&hard_iface->refcount);
 748         hard_iface->batman_adv_ptype.type = ethertype;
 749         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 750         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 751         dev_add_pack(&hard_iface->batman_adv_ptype);
 752
 753         batadv_info(hard_iface->mesh_iface, "Adding interface: %s\n",
 754                     hard_iface->net_dev->name);
 755
 756         if (atomic_read(&bat_priv->fragmentation) &&
 757             hardif_mtu < required_mtu)
 758                 batadv_info(hard_iface->mesh_iface,
 759                             "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",
 760                             hard_iface->net_dev->name, hardif_mtu,
 761                             required_mtu);
 762
 763         if (!atomic_read(&bat_priv->fragmentation) &&
 764             hardif_mtu < required_mtu)
 765                 batadv_info(hard_iface->mesh_iface,
 766                             "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",
 767                             hard_iface->net_dev->name, hardif_mtu,
 768                             required_mtu);
 769
 770         batadv_check_known_mac_addr(hard_iface);
 771
 772         if (batadv_hardif_is_iface_up(hard_iface))
 773                 batadv_hardif_activate_interface(hard_iface);
 774         else
 775                 batadv_err(hard_iface->mesh_iface,
 776                            "Not using interface %s (retrying later): interface not active\n",
 777                            hard_iface->net_dev->name);
 778
 779         batadv_hardif_recalc_extra_skbroom(mesh_iface);
 780
 781         if (bat_priv->algo_ops->iface.enabled)
 782                 bat_priv->algo_ops->iface.enabled(hard_iface);
 783
 784 out:
 785         return 0;
 786
 787 err_upper:
 788         netdev_upper_dev_unlink(hard_iface->net_dev, mesh_iface);
 789 err_dev:
 790         hard_iface->mesh_iface = NULL;
 791         netdev_put(mesh_iface, &hard_iface->meshif_dev_tracker);
 792         batadv_hardif_put(hard_iface);
 793         return ret;
 794 }
 795
 796 /**
 797  * batadv_hardif_cnt() - get number of interfaces enslaved to mesh interface
 798  * @mesh_iface: mesh interface to check
 799  *
 800  * This function is only using RCU for locking - the result can therefore be
 801  * off when another function is modifying the list at the same time. The
 802  * caller can use the rtnl_lock to make sure that the count is accurate.
 803  *
 804  * Return: number of connected/enslaved hard interfaces
 805  */
 806 static size_t batadv_hardif_cnt(const struct net_device *mesh_iface)
 807 {
 808         struct batadv_hard_iface *hard_iface;
 809         size_t count = 0;
 810
 811         rcu_read_lock();
 812         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 813                 if (hard_iface->mesh_iface != mesh_iface)
 814                         continue;
 815
 816                 count++;
 817         }
 818         rcu_read_unlock();
 819
 820         return count;
 821 }
 822
 823 /**
 824  * batadv_hardif_disable_interface() - Remove hard interface from mesh interface
 825  * @hard_iface: hard interface to be removed
 826  */
 827 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
 828 {
 829         struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface);
 830         struct batadv_hard_iface *primary_if = NULL;
 831
 832         batadv_hardif_deactivate_interface(hard_iface);
 833
 834         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 835                 goto out;
 836
 837         batadv_info(hard_iface->mesh_iface, "Removing interface: %s\n",
 838                     hard_iface->net_dev->name);
 839         dev_remove_pack(&hard_iface->batman_adv_ptype);
 840         batadv_hardif_put(hard_iface);
 841
 842         primary_if = batadv_primary_if_get_selected(bat_priv);
 843         if (hard_iface == primary_if) {
 844                 struct batadv_hard_iface *new_if;
 845
 846                 new_if = batadv_hardif_get_active(hard_iface->mesh_iface);
 847                 batadv_primary_if_select(bat_priv, new_if);
 848
 849                 batadv_hardif_put(new_if);
 850         }
 851
 852         bat_priv->algo_ops->iface.disable(hard_iface);
 853         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 854
 855         /* delete all references to this hard_iface */
 856         batadv_purge_orig_ref(bat_priv);
 857         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 858         netdev_put(hard_iface->mesh_iface, &hard_iface->meshif_dev_tracker);
 859
 860         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->mesh_iface);
 861         batadv_hardif_recalc_extra_skbroom(hard_iface->mesh_iface);
 862
 863         /* nobody uses this interface anymore */
 864         if (batadv_hardif_cnt(hard_iface->mesh_iface) <= 1)
 865                 batadv_gw_check_client_stop(bat_priv);
 866
 867         hard_iface->mesh_iface = NULL;
 868         batadv_hardif_put(hard_iface);
 869
 870 out:
 871         batadv_hardif_put(primary_if);
 872 }
 873
 874 static struct batadv_hard_iface *
 875 batadv_hardif_add_interface(struct net_device *net_dev)
 876 {
 877         struct batadv_hard_iface *hard_iface;
 878
 879         ASSERT_RTNL();
 880
 881         if (!batadv_is_valid_iface(net_dev))
 882                 return NULL;
 883
 884         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 885         if (!hard_iface)
 886                 return NULL;
 887
 888         netdev_hold(net_dev, &hard_iface->dev_tracker, GFP_ATOMIC);
 889         hard_iface->net_dev = net_dev;
 890
 891         hard_iface->mesh_iface = NULL;
 892         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 893
 894         INIT_LIST_HEAD(&hard_iface->list);
 895         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 896
 897         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 898         spin_lock_init(&hard_iface->neigh_list_lock);
 899         kref_init(&hard_iface->refcount);
 900
 901         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 902         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 903         if (batadv_is_wifi_hardif(hard_iface))
 904                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 905
 906         atomic_set(&hard_iface->hop_penalty, 0);
 907
 908         batadv_v_hardif_init(hard_iface);
 909
 910         kref_get(&hard_iface->refcount);
 911         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 912         batadv_hardif_generation++;
 913
 914         return hard_iface;
 915 }
 916
 917 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 918 {
 919         ASSERT_RTNL();
 920
 921         /* first deactivate interface */
 922         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 923                 batadv_hardif_disable_interface(hard_iface);
 924
 925         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 926                 return;
 927
 928         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 929         batadv_hardif_put(hard_iface);
 930 }
 931
 932 /**
 933  * batadv_hard_if_event_meshif() - Handle events for mesh interfaces
 934  * @event: NETDEV_* event to handle
 935  * @net_dev: net_device which generated an event
 936  *
 937  * Return: NOTIFY_* result
 938  */
 939 static int batadv_hard_if_event_meshif(unsigned long event,
 940                                        struct net_device *net_dev)
 941 {
 942         struct batadv_priv *bat_priv;
 943
 944         switch (event) {
 945         case NETDEV_REGISTER:
 946                 bat_priv = netdev_priv(net_dev);
 947                 batadv_meshif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 948                 break;
 949         }
 950
 951         return NOTIFY_DONE;
 952 }
 953
 954 static int batadv_hard_if_event(struct notifier_block *this,
 955                                 unsigned long event, void *ptr)
 956 {
 957         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 958         struct batadv_hard_iface *hard_iface;
 959         struct batadv_hard_iface *primary_if = NULL;
 960         struct batadv_priv *bat_priv;
 961
 962         if (batadv_meshif_is_valid(net_dev))
 963                 return batadv_hard_if_event_meshif(event, net_dev);
 964
 965         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 966         if (!hard_iface && (event == NETDEV_REGISTER ||
 967                             event == NETDEV_POST_TYPE_CHANGE))
 968                 hard_iface = batadv_hardif_add_interface(net_dev);
 969
 970         if (!hard_iface)
 971                 goto out;
 972
 973         switch (event) {
 974         case NETDEV_UP:
 975                 batadv_hardif_activate_interface(hard_iface);
 976                 break;
 977         case NETDEV_GOING_DOWN:
 978         case NETDEV_DOWN:
 979                 batadv_hardif_deactivate_interface(hard_iface);
 980                 break;
 981         case NETDEV_UNREGISTER:
 982         case NETDEV_PRE_TYPE_CHANGE:
 983                 list_del_rcu(&hard_iface->list);
 984                 batadv_hardif_generation++;
 985
 986                 batadv_hardif_remove_interface(hard_iface);
 987                 break;
 988         case NETDEV_CHANGEMTU:
 989                 if (hard_iface->mesh_iface)
 990                         batadv_update_min_mtu(hard_iface->mesh_iface);
 991                 break;
 992         case NETDEV_CHANGEADDR:
 993                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 994                         goto hardif_put;
 995
 996                 batadv_check_known_mac_addr(hard_iface);
 997
 998                 bat_priv = netdev_priv(hard_iface->mesh_iface);
 999                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1000
1001                 primary_if = batadv_primary_if_get_selected(bat_priv);
1002                 if (!primary_if)
1003                         goto hardif_put;
1004
1005                 if (hard_iface == primary_if)
1006                         batadv_primary_if_update_addr(bat_priv, NULL);
1007                 break;
1008         case NETDEV_CHANGEUPPER:
1009                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1010                 if (batadv_is_wifi_hardif(hard_iface))
1011                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1012                 break;
1013         default:
1014                 break;
1015         }
1016
1017 hardif_put:
1018         batadv_hardif_put(hard_iface);
1019 out:
1020         batadv_hardif_put(primary_if);
1021         return NOTIFY_DONE;
1022 }
1023
1024 struct notifier_block batadv_hard_if_notifier = {
1025         .notifier_call = batadv_hard_if_event,
1026 };