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