net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2020  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/errno.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/kernel.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         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         /* no more parents..stop recursion */
 160         if (dev_get_iflink(net_dev) == 0 ||
 161             dev_get_iflink(net_dev) == net_dev->ifindex)
 162                 return false;
 163
 164         parent_net = batadv_getlink_net(net_dev, net);
 165
 166         /* recurse over the parent device */
 167         parent_dev = __dev_get_by_index((struct net *)parent_net,
 168                                         dev_get_iflink(net_dev));
 169         /* if we got a NULL parent_dev there is something broken.. */
 170         if (!parent_dev) {
 171                 pr_err("Cannot find parent device\n");
 172                 return false;
 173         }
 174
 175         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 176                 return false;
 177
 178         ret = batadv_is_on_batman_iface(parent_dev);
 179
 180         return ret;
 181 }
 182
 183 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 184 {
 185         if (net_dev->flags & IFF_LOOPBACK)
 186                 return false;
 187
 188         if (net_dev->type != ARPHRD_ETHER)
 189                 return false;
 190
 191         if (net_dev->addr_len != ETH_ALEN)
 192                 return false;
 193
 194         /* no batman over batman */
 195         if (batadv_is_on_batman_iface(net_dev))
 196                 return false;
 197
 198         return true;
 199 }
 200
 201 /**
 202  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 203  *  interface on top of another 'real' interface
 204  * @netdev: the device to check
 205  *
 206  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 207  * instead of this.
 208  *
 209  * Return: the 'real' net device or the original net device and NULL in case
 210  *  of an error.
 211  */
 212 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 213 {
 214         struct batadv_hard_iface *hard_iface = NULL;
 215         struct net_device *real_netdev = NULL;
 216         struct net *real_net;
 217         struct net *net;
 218         int ifindex;
 219
 220         ASSERT_RTNL();
 221
 222         if (!netdev)
 223                 return NULL;
 224
 225         if (netdev->ifindex == dev_get_iflink(netdev)) {
 226                 dev_hold(netdev);
 227                 return netdev;
 228         }
 229
 230         hard_iface = batadv_hardif_get_by_netdev(netdev);
 231         if (!hard_iface || !hard_iface->soft_iface)
 232                 goto out;
 233
 234         net = dev_net(hard_iface->soft_iface);
 235         ifindex = dev_get_iflink(netdev);
 236         real_net = batadv_getlink_net(netdev, net);
 237         real_netdev = dev_get_by_index(real_net, ifindex);
 238
 239 out:
 240         if (hard_iface)
 241                 batadv_hardif_put(hard_iface);
 242         return real_netdev;
 243 }
 244
 245 /**
 246  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 247  *  interface on top of another 'real' interface
 248  * @net_device: the device to check
 249  *
 250  * Return: the 'real' net device or the original net device and NULL in case
 251  *  of an error.
 252  */
 253 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 254 {
 255         struct net_device *real_netdev;
 256
 257         rtnl_lock();
 258         real_netdev = batadv_get_real_netdevice(net_device);
 259         rtnl_unlock();
 260
 261         return real_netdev;
 262 }
 263
 264 /**
 265  * batadv_is_wext_netdev() - check if the given net_device struct is a
 266  *  wext wifi interface
 267  * @net_device: the device to check
 268  *
 269  * Return: true if the net device is a wext wireless device, false
 270  *  otherwise.
 271  */
 272 static bool batadv_is_wext_netdev(struct net_device *net_device)
 273 {
 274         if (!net_device)
 275                 return false;
 276
 277 #ifdef CONFIG_WIRELESS_EXT
 278         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 279          * check for wireless_handlers != NULL
 280          */
 281         if (net_device->wireless_handlers)
 282                 return true;
 283 #endif
 284
 285         return false;
 286 }
 287
 288 /**
 289  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 290  *  cfg80211 wifi interface
 291  * @net_device: the device to check
 292  *
 293  * Return: true if the net device is a cfg80211 wireless device, false
 294  *  otherwise.
 295  */
 296 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 297 {
 298         if (!net_device)
 299                 return false;
 300
 301         /* cfg80211 drivers have to set ieee80211_ptr */
 302         if (net_device->ieee80211_ptr)
 303                 return true;
 304
 305         return false;
 306 }
 307
 308 /**
 309  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 310  * @net_device: the device to check
 311  *
 312  * Return: batadv_hard_iface_wifi_flags flags of the device
 313  */
 314 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 315 {
 316         u32 wifi_flags = 0;
 317         struct net_device *real_netdev;
 318
 319         if (batadv_is_wext_netdev(net_device))
 320                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 321
 322         if (batadv_is_cfg80211_netdev(net_device))
 323                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 324
 325         real_netdev = batadv_get_real_netdevice(net_device);
 326         if (!real_netdev)
 327                 return wifi_flags;
 328
 329         if (real_netdev == net_device)
 330                 goto out;
 331
 332         if (batadv_is_wext_netdev(real_netdev))
 333                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 334
 335         if (batadv_is_cfg80211_netdev(real_netdev))
 336                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 337
 338 out:
 339         dev_put(real_netdev);
 340         return wifi_flags;
 341 }
 342
 343 /**
 344  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 345  *  interface
 346  * @hard_iface: the device to check
 347  *
 348  * Return: true if the net device is a cfg80211 wireless device, false
 349  *  otherwise.
 350  */
 351 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 352 {
 353         u32 allowed_flags = 0;
 354
 355         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 356         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 357
 358         return !!(hard_iface->wifi_flags & allowed_flags);
 359 }
 360
 361 /**
 362  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 363  * @hard_iface: the device to check
 364  *
 365  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 366  */
 367 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 368 {
 369         if (!hard_iface)
 370                 return false;
 371
 372         return hard_iface->wifi_flags != 0;
 373 }
 374
 375 /**
 376  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 377  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 378  * @orig_addr: the originator of this packet
 379  * @orig_neigh: originator address of the forwarder we just got the packet from
 380  *  (NULL if we originated)
 381  *
 382  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 383  *
 384  * Return:
 385  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 386  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 387  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 388  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 389  */
 390 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 391                                u8 *orig_addr, u8 *orig_neigh)
 392 {
 393         struct batadv_hardif_neigh_node *hardif_neigh;
 394         struct hlist_node *first;
 395         int ret = BATADV_HARDIF_BCAST_OK;
 396
 397         rcu_read_lock();
 398
 399         /* 0 neighbors -> no (re)broadcast */
 400         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 401         if (!first) {
 402                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 403                 goto out;
 404         }
 405
 406         /* >1 neighbors -> (re)brodcast */
 407         if (rcu_dereference(hlist_next_rcu(first)))
 408                 goto out;
 409
 410         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 411                                    list);
 412
 413         /* 1 neighbor, is the originator -> no rebroadcast */
 414         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 415                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 416         /* 1 neighbor, is the one we received from -> no rebroadcast */
 417         } else if (orig_neigh &&
 418                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 419                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 420         }
 421
 422 out:
 423         rcu_read_unlock();
 424         return ret;
 425 }
 426
 427 static struct batadv_hard_iface *
 428 batadv_hardif_get_active(const struct net_device *soft_iface)
 429 {
 430         struct batadv_hard_iface *hard_iface;
 431
 432         rcu_read_lock();
 433         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 434                 if (hard_iface->soft_iface != soft_iface)
 435                         continue;
 436
 437                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 438                     kref_get_unless_zero(&hard_iface->refcount))
 439                         goto out;
 440         }
 441
 442         hard_iface = NULL;
 443
 444 out:
 445         rcu_read_unlock();
 446         return hard_iface;
 447 }
 448
 449 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 450                                           struct batadv_hard_iface *oldif)
 451 {
 452         struct batadv_hard_iface *primary_if;
 453
 454         primary_if = batadv_primary_if_get_selected(bat_priv);
 455         if (!primary_if)
 456                 goto out;
 457
 458         batadv_dat_init_own_addr(bat_priv, primary_if);
 459         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 460 out:
 461         if (primary_if)
 462                 batadv_hardif_put(primary_if);
 463 }
 464
 465 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 466                                      struct batadv_hard_iface *new_hard_iface)
 467 {
 468         struct batadv_hard_iface *curr_hard_iface;
 469
 470         ASSERT_RTNL();
 471
 472         if (new_hard_iface)
 473                 kref_get(&new_hard_iface->refcount);
 474
 475         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 476                                               new_hard_iface, 1);
 477
 478         if (!new_hard_iface)
 479                 goto out;
 480
 481         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 482         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 483
 484 out:
 485         if (curr_hard_iface)
 486                 batadv_hardif_put(curr_hard_iface);
 487 }
 488
 489 static bool
 490 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 491 {
 492         if (hard_iface->net_dev->flags & IFF_UP)
 493                 return true;
 494
 495         return false;
 496 }
 497
 498 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 499 {
 500         const struct batadv_hard_iface *hard_iface;
 501
 502         rcu_read_lock();
 503         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 504                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 505                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 506                         continue;
 507
 508                 if (hard_iface->net_dev == net_dev)
 509                         continue;
 510
 511                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 512                                         net_dev->dev_addr))
 513                         continue;
 514
 515                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 516                         net_dev->dev_addr, hard_iface->net_dev->name);
 517                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 518         }
 519         rcu_read_unlock();
 520 }
 521
 522 /**
 523  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 524  * @soft_iface: netdev struct of the mesh interface
 525  */
 526 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 527 {
 528         const struct batadv_hard_iface *hard_iface;
 529         unsigned short lower_header_len = ETH_HLEN;
 530         unsigned short lower_headroom = 0;
 531         unsigned short lower_tailroom = 0;
 532         unsigned short needed_headroom;
 533
 534         rcu_read_lock();
 535         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 536                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 537                         continue;
 538
 539                 if (hard_iface->soft_iface != soft_iface)
 540                         continue;
 541
 542                 lower_header_len = max_t(unsigned short, lower_header_len,
 543                                          hard_iface->net_dev->hard_header_len);
 544
 545                 lower_headroom = max_t(unsigned short, lower_headroom,
 546                                        hard_iface->net_dev->needed_headroom);
 547
 548                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 549                                        hard_iface->net_dev->needed_tailroom);
 550         }
 551         rcu_read_unlock();
 552
 553         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 554         needed_headroom += batadv_max_header_len();
 555
 556         /* fragmentation headers don't strip the unicast/... header */
 557         needed_headroom += sizeof(struct batadv_frag_packet);
 558
 559         soft_iface->needed_headroom = needed_headroom;
 560         soft_iface->needed_tailroom = lower_tailroom;
 561 }
 562
 563 /**
 564  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 565  * @soft_iface: netdev struct of the soft interface
 566  *
 567  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 568  *  slave interfaces)
 569  */
 570 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 571 {
 572         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 573         const struct batadv_hard_iface *hard_iface;
 574         int min_mtu = INT_MAX;
 575
 576         rcu_read_lock();
 577         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 578                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 579                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 580                         continue;
 581
 582                 if (hard_iface->soft_iface != soft_iface)
 583                         continue;
 584
 585                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 586         }
 587         rcu_read_unlock();
 588
 589         if (atomic_read(&bat_priv->fragmentation) == 0)
 590                 goto out;
 591
 592         /* with fragmentation enabled the maximum size of internally generated
 593          * packets such as translation table exchanges or tvlv containers, etc
 594          * has to be calculated
 595          */
 596         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 597         min_mtu -= sizeof(struct batadv_frag_packet);
 598         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 599
 600 out:
 601         /* report to the other components the maximum amount of bytes that
 602          * batman-adv can send over the wire (without considering the payload
 603          * overhead). For example, this value is used by TT to compute the
 604          * maximum local table size
 605          */
 606         atomic_set(&bat_priv->packet_size_max, min_mtu);
 607
 608         /* the real soft-interface MTU is computed by removing the payload
 609          * overhead from the maximum amount of bytes that was just computed.
 610          *
 611          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 612          */
 613         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 614 }
 615
 616 /**
 617  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 618  *  MTU appeared
 619  * @soft_iface: netdev struct of the soft interface
 620  */
 621 void batadv_update_min_mtu(struct net_device *soft_iface)
 622 {
 623         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 624
 625         /* Check if the local translate table should be cleaned up to match a
 626          * new (and smaller) MTU.
 627          */
 628         batadv_tt_local_resize_to_mtu(soft_iface);
 629 }
 630
 631 static void
 632 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 633 {
 634         struct batadv_priv *bat_priv;
 635         struct batadv_hard_iface *primary_if = NULL;
 636
 637         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 638                 goto out;
 639
 640         bat_priv = netdev_priv(hard_iface->soft_iface);
 641
 642         bat_priv->algo_ops->iface.update_mac(hard_iface);
 643         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 644
 645         /* the first active interface becomes our primary interface or
 646          * the next active interface after the old primary interface was removed
 647          */
 648         primary_if = batadv_primary_if_get_selected(bat_priv);
 649         if (!primary_if)
 650                 batadv_primary_if_select(bat_priv, hard_iface);
 651
 652         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 653                     hard_iface->net_dev->name);
 654
 655         batadv_update_min_mtu(hard_iface->soft_iface);
 656
 657         if (bat_priv->algo_ops->iface.activate)
 658                 bat_priv->algo_ops->iface.activate(hard_iface);
 659
 660 out:
 661         if (primary_if)
 662                 batadv_hardif_put(primary_if);
 663 }
 664
 665 static void
 666 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 667 {
 668         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 669             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 670                 return;
 671
 672         hard_iface->if_status = BATADV_IF_INACTIVE;
 673
 674         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 675                     hard_iface->net_dev->name);
 676
 677         batadv_update_min_mtu(hard_iface->soft_iface);
 678 }
 679
 680 /**
 681  * batadv_master_del_slave() - remove hard_iface from the current master iface
 682  * @slave: the interface enslaved in another master
 683  * @master: the master from which slave has to be removed
 684  *
 685  * Invoke ndo_del_slave on master passing slave as argument. In this way the
 686  * slave is free'd and the master can correctly change its internal state.
 687  *
 688  * Return: 0 on success, a negative value representing the error otherwise
 689  */
 690 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 691                                    struct net_device *master)
 692 {
 693         int ret;
 694
 695         if (!master)
 696                 return 0;
 697
 698         ret = -EBUSY;
 699         if (master->netdev_ops->ndo_del_slave)
 700                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 701
 702         return ret;
 703 }
 704
 705 /**
 706  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 707  * @hard_iface: hard interface to add to soft interface
 708  * @net: the applicable net namespace
 709  * @iface_name: name of the soft interface
 710  *
 711  * Return: 0 on success or negative error number in case of failure
 712  */
 713 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 714                                    struct net *net, const char *iface_name)
 715 {
 716         struct batadv_priv *bat_priv;
 717         struct net_device *soft_iface, *master;
 718         __be16 ethertype = htons(ETH_P_BATMAN);
 719         int max_header_len = batadv_max_header_len();
 720         int ret;
 721
 722         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 723                 goto out;
 724
 725         kref_get(&hard_iface->refcount);
 726
 727         soft_iface = dev_get_by_name(net, iface_name);
 728
 729         if (!soft_iface) {
 730                 soft_iface = batadv_softif_create(net, iface_name);
 731
 732                 if (!soft_iface) {
 733                         ret = -ENOMEM;
 734                         goto err;
 735                 }
 736
 737                 /* dev_get_by_name() increases the reference counter for us */
 738                 dev_hold(soft_iface);
 739         }
 740
 741         if (!batadv_softif_is_valid(soft_iface)) {
 742                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 743                        soft_iface->name);
 744                 ret = -EINVAL;
 745                 goto err_dev;
 746         }
 747
 748         /* check if the interface is enslaved in another virtual one and
 749          * in that case unlink it first
 750          */
 751         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 752         ret = batadv_master_del_slave(hard_iface, master);
 753         if (ret)
 754                 goto err_dev;
 755
 756         hard_iface->soft_iface = soft_iface;
 757         bat_priv = netdev_priv(hard_iface->soft_iface);
 758
 759         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 760                                            soft_iface, NULL, NULL, NULL);
 761         if (ret)
 762                 goto err_dev;
 763
 764         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 765         if (ret < 0)
 766                 goto err_upper;
 767
 768         hard_iface->if_status = BATADV_IF_INACTIVE;
 769
 770         kref_get(&hard_iface->refcount);
 771         hard_iface->batman_adv_ptype.type = ethertype;
 772         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 773         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 774         dev_add_pack(&hard_iface->batman_adv_ptype);
 775
 776         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 777                     hard_iface->net_dev->name);
 778
 779         if (atomic_read(&bat_priv->fragmentation) &&
 780             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 781                 batadv_info(hard_iface->soft_iface,
 782                             "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",
 783                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 784                             ETH_DATA_LEN + max_header_len);
 785
 786         if (!atomic_read(&bat_priv->fragmentation) &&
 787             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 788                 batadv_info(hard_iface->soft_iface,
 789                             "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",
 790                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 791                             ETH_DATA_LEN + max_header_len);
 792
 793         if (batadv_hardif_is_iface_up(hard_iface))
 794                 batadv_hardif_activate_interface(hard_iface);
 795         else
 796                 batadv_err(hard_iface->soft_iface,
 797                            "Not using interface %s (retrying later): interface not active\n",
 798                            hard_iface->net_dev->name);
 799
 800         batadv_hardif_recalc_extra_skbroom(soft_iface);
 801
 802         if (bat_priv->algo_ops->iface.enabled)
 803                 bat_priv->algo_ops->iface.enabled(hard_iface);
 804
 805 out:
 806         return 0;
 807
 808 err_upper:
 809         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 810 err_dev:
 811         hard_iface->soft_iface = NULL;
 812         dev_put(soft_iface);
 813 err:
 814         batadv_hardif_put(hard_iface);
 815         return ret;
 816 }
 817
 818 /**
 819  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 820  * @soft_iface: soft interface to check
 821  *
 822  * This function is only using RCU for locking - the result can therefore be
 823  * off when another function is modifying the list at the same time. The
 824  * caller can use the rtnl_lock to make sure that the count is accurate.
 825  *
 826  * Return: number of connected/enslaved hard interfaces
 827  */
 828 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 829 {
 830         struct batadv_hard_iface *hard_iface;
 831         size_t count = 0;
 832
 833         rcu_read_lock();
 834         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 835                 if (hard_iface->soft_iface != soft_iface)
 836                         continue;
 837
 838                 count++;
 839         }
 840         rcu_read_unlock();
 841
 842         return count;
 843 }
 844
 845 /**
 846  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 847  * @hard_iface: hard interface to be removed
 848  */
 849 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
 850 {
 851         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 852         struct batadv_hard_iface *primary_if = NULL;
 853
 854         batadv_hardif_deactivate_interface(hard_iface);
 855
 856         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 857                 goto out;
 858
 859         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 860                     hard_iface->net_dev->name);
 861         dev_remove_pack(&hard_iface->batman_adv_ptype);
 862         batadv_hardif_put(hard_iface);
 863
 864         primary_if = batadv_primary_if_get_selected(bat_priv);
 865         if (hard_iface == primary_if) {
 866                 struct batadv_hard_iface *new_if;
 867
 868                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 869                 batadv_primary_if_select(bat_priv, new_if);
 870
 871                 if (new_if)
 872                         batadv_hardif_put(new_if);
 873         }
 874
 875         bat_priv->algo_ops->iface.disable(hard_iface);
 876         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 877
 878         /* delete all references to this hard_iface */
 879         batadv_purge_orig_ref(bat_priv);
 880         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 881         dev_put(hard_iface->soft_iface);
 882
 883         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 884         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 885
 886         /* nobody uses this interface anymore */
 887         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1)
 888                 batadv_gw_check_client_stop(bat_priv);
 889
 890         hard_iface->soft_iface = NULL;
 891         batadv_hardif_put(hard_iface);
 892
 893 out:
 894         if (primary_if)
 895                 batadv_hardif_put(primary_if);
 896 }
 897
 898 static struct batadv_hard_iface *
 899 batadv_hardif_add_interface(struct net_device *net_dev)
 900 {
 901         struct batadv_hard_iface *hard_iface;
 902
 903         ASSERT_RTNL();
 904
 905         if (!batadv_is_valid_iface(net_dev))
 906                 goto out;
 907
 908         dev_hold(net_dev);
 909
 910         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 911         if (!hard_iface)
 912                 goto release_dev;
 913
 914         hard_iface->net_dev = net_dev;
 915         hard_iface->soft_iface = NULL;
 916         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 917
 918         INIT_LIST_HEAD(&hard_iface->list);
 919         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 920
 921         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 922         spin_lock_init(&hard_iface->neigh_list_lock);
 923         kref_init(&hard_iface->refcount);
 924
 925         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 926         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 927         if (batadv_is_wifi_hardif(hard_iface))
 928                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 929
 930         atomic_set(&hard_iface->hop_penalty, 0);
 931
 932         batadv_v_hardif_init(hard_iface);
 933
 934         batadv_check_known_mac_addr(hard_iface->net_dev);
 935         kref_get(&hard_iface->refcount);
 936         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 937         batadv_hardif_generation++;
 938
 939         return hard_iface;
 940
 941 release_dev:
 942         dev_put(net_dev);
 943 out:
 944         return NULL;
 945 }
 946
 947 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 948 {
 949         ASSERT_RTNL();
 950
 951         /* first deactivate interface */
 952         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 953                 batadv_hardif_disable_interface(hard_iface);
 954
 955         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 956                 return;
 957
 958         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 959         batadv_hardif_put(hard_iface);
 960 }
 961
 962 /**
 963  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 964  * @event: NETDEV_* event to handle
 965  * @net_dev: net_device which generated an event
 966  *
 967  * Return: NOTIFY_* result
 968  */
 969 static int batadv_hard_if_event_softif(unsigned long event,
 970                                        struct net_device *net_dev)
 971 {
 972         struct batadv_priv *bat_priv;
 973
 974         switch (event) {
 975         case NETDEV_REGISTER:
 976                 bat_priv = netdev_priv(net_dev);
 977                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 978                 break;
 979         }
 980
 981         return NOTIFY_DONE;
 982 }
 983
 984 static int batadv_hard_if_event(struct notifier_block *this,
 985                                 unsigned long event, void *ptr)
 986 {
 987         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 988         struct batadv_hard_iface *hard_iface;
 989         struct batadv_hard_iface *primary_if = NULL;
 990         struct batadv_priv *bat_priv;
 991
 992         if (batadv_softif_is_valid(net_dev))
 993                 return batadv_hard_if_event_softif(event, net_dev);
 994
 995         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 996         if (!hard_iface && (event == NETDEV_REGISTER ||
 997                             event == NETDEV_POST_TYPE_CHANGE))
 998                 hard_iface = batadv_hardif_add_interface(net_dev);
 999
1000         if (!hard_iface)
1001                 goto out;
1002
1003         switch (event) {
1004         case NETDEV_UP:
1005                 batadv_hardif_activate_interface(hard_iface);
1006                 break;
1007         case NETDEV_GOING_DOWN:
1008         case NETDEV_DOWN:
1009                 batadv_hardif_deactivate_interface(hard_iface);
1010                 break;
1011         case NETDEV_UNREGISTER:
1012         case NETDEV_PRE_TYPE_CHANGE:
1013                 list_del_rcu(&hard_iface->list);
1014                 batadv_hardif_generation++;
1015
1016                 batadv_hardif_remove_interface(hard_iface);
1017                 break;
1018         case NETDEV_CHANGEMTU:
1019                 if (hard_iface->soft_iface)
1020                         batadv_update_min_mtu(hard_iface->soft_iface);
1021                 break;
1022         case NETDEV_CHANGEADDR:
1023                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1024                         goto hardif_put;
1025
1026                 batadv_check_known_mac_addr(hard_iface->net_dev);
1027
1028                 bat_priv = netdev_priv(hard_iface->soft_iface);
1029                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1030
1031                 primary_if = batadv_primary_if_get_selected(bat_priv);
1032                 if (!primary_if)
1033                         goto hardif_put;
1034
1035                 if (hard_iface == primary_if)
1036                         batadv_primary_if_update_addr(bat_priv, NULL);
1037                 break;
1038         case NETDEV_CHANGEUPPER:
1039                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1040                 if (batadv_is_wifi_hardif(hard_iface))
1041                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1042                 break;
1043         default:
1044                 break;
1045         }
1046
1047 hardif_put:
1048         batadv_hardif_put(hard_iface);
1049 out:
1050         if (primary_if)
1051                 batadv_hardif_put(primary_if);
1052         return NOTIFY_DONE;
1053 }
1054
1055 struct notifier_block batadv_hard_if_notifier = {
1056         .notifier_call = batadv_hard_if_event,
1057 };