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