net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "hard-interface.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/gfp.h>
  13 #include <linux/if.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/kernel.h>
  17 #include <linux/kref.h>
  18 #include <linux/limits.h>
  19 #include <linux/list.h>
  20 #include <linux/minmax.h>
  21 #include <linux/mutex.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/printk.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rtnetlink.h>
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <net/net_namespace.h>
  29 #include <net/rtnetlink.h>
  30 #include <uapi/linux/batadv_packet.h>
  31
  32 #include "bat_v.h"
  33 #include "bridge_loop_avoidance.h"
  34 #include "distributed-arp-table.h"
  35 #include "gateway_client.h"
  36 #include "log.h"
  37 #include "originator.h"
  38 #include "send.h"
  39 #include "soft-interface.h"
  40 #include "translation-table.h"
  41
  42 /**
  43  * batadv_hardif_release() - release hard interface from lists and queue for
  44  *  free after rcu grace period
  45  * @ref: kref pointer of the hard interface
  46  */
  47 void batadv_hardif_release(struct kref *ref)
  48 {
  49         struct batadv_hard_iface *hard_iface;
  50
  51         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  52         dev_put(hard_iface->net_dev);
  53
  54         kfree_rcu(hard_iface, rcu);
  55 }
  56
  57 /**
  58  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  59  * @net_dev: net_device to search for
  60  *
  61  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  62  */
  63 struct batadv_hard_iface *
  64 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  65 {
  66         struct batadv_hard_iface *hard_iface;
  67
  68         rcu_read_lock();
  69         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  70                 if (hard_iface->net_dev == net_dev &&
  71                     kref_get_unless_zero(&hard_iface->refcount))
  72                         goto out;
  73         }
  74
  75         hard_iface = NULL;
  76
  77 out:
  78         rcu_read_unlock();
  79         return hard_iface;
  80 }
  81
  82 /**
  83  * batadv_getlink_net() - return link net namespace (of use fallback)
  84  * @netdev: net_device to check
  85  * @fallback_net: return in case get_link_net is not available for @netdev
  86  *
  87  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  88  */
  89 static struct net *batadv_getlink_net(const struct net_device *netdev,
  90                                       struct net *fallback_net)
  91 {
  92         if (!netdev->rtnl_link_ops)
  93                 return fallback_net;
  94
  95         if (!netdev->rtnl_link_ops->get_link_net)
  96                 return fallback_net;
  97
  98         return netdev->rtnl_link_ops->get_link_net(netdev);
  99 }
 100
 101 /**
 102  * batadv_mutual_parents() - check if two devices are each others parent
 103  * @dev1: 1st net dev
 104  * @net1: 1st devices netns
 105  * @dev2: 2nd net dev
 106  * @net2: 2nd devices netns
 107  *
 108  * veth devices come in pairs and each is the parent of the other!
 109  *
 110  * Return: true if the devices are each others parent, otherwise false
 111  */
 112 static bool batadv_mutual_parents(const struct net_device *dev1,
 113                                   struct net *net1,
 114                                   const struct net_device *dev2,
 115                                   struct net *net2)
 116 {
 117         int dev1_parent_iflink = dev_get_iflink(dev1);
 118         int dev2_parent_iflink = dev_get_iflink(dev2);
 119         const struct net *dev1_parent_net;
 120         const struct net *dev2_parent_net;
 121
 122         dev1_parent_net = batadv_getlink_net(dev1, net1);
 123         dev2_parent_net = batadv_getlink_net(dev2, net2);
 124
 125         if (!dev1_parent_iflink || !dev2_parent_iflink)
 126                 return false;
 127
 128         return (dev1_parent_iflink == dev2->ifindex) &&
 129                (dev2_parent_iflink == dev1->ifindex) &&
 130                net_eq(dev1_parent_net, net2) &&
 131                net_eq(dev2_parent_net, net1);
 132 }
 133
 134 /**
 135  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 136  * @net_dev: the device to check
 137  *
 138  * If the user creates any virtual device on top of a batman-adv interface, it
 139  * is important to prevent this new interface from being used to create a new
 140  * mesh network (this behaviour would lead to a batman-over-batman
 141  * configuration). This function recursively checks all the fathers of the
 142  * device passed as argument looking for a batman-adv soft interface.
 143  *
 144  * Return: true if the device is descendant of a batman-adv mesh interface (or
 145  * if it is a batman-adv interface itself), false otherwise
 146  */
 147 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 148 {
 149         struct net *net = dev_net(net_dev);
 150         struct net_device *parent_dev;
 151         struct net *parent_net;
 152         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 we got a NULL parent_dev there is something broken.. */
 172         if (!parent_dev) {
 173                 pr_err("Cannot find parent device\n");
 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         /* cfg80211 drivers have to set ieee80211_ptr */
 311         if (net_device->ieee80211_ptr)
 312                 return true;
 313
 314         return false;
 315 }
 316
 317 /**
 318  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 319  * @net_device: the device to check
 320  *
 321  * Return: batadv_hard_iface_wifi_flags flags of the device
 322  */
 323 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 324 {
 325         u32 wifi_flags = 0;
 326         struct net_device *real_netdev;
 327
 328         if (batadv_is_wext_netdev(net_device))
 329                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 330
 331         if (batadv_is_cfg80211_netdev(net_device))
 332                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 333
 334         real_netdev = batadv_get_real_netdevice(net_device);
 335         if (!real_netdev)
 336                 return wifi_flags;
 337
 338         if (real_netdev == net_device)
 339                 goto out;
 340
 341         if (batadv_is_wext_netdev(real_netdev))
 342                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 343
 344         if (batadv_is_cfg80211_netdev(real_netdev))
 345                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 346
 347 out:
 348         dev_put(real_netdev);
 349         return wifi_flags;
 350 }
 351
 352 /**
 353  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 354  *  interface
 355  * @hard_iface: the device to check
 356  *
 357  * Return: true if the net device is a cfg80211 wireless device, false
 358  *  otherwise.
 359  */
 360 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 361 {
 362         u32 allowed_flags = 0;
 363
 364         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 365         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 366
 367         return !!(hard_iface->wifi_flags & allowed_flags);
 368 }
 369
 370 /**
 371  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 372  * @hard_iface: the device to check
 373  *
 374  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 375  */
 376 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 377 {
 378         if (!hard_iface)
 379                 return false;
 380
 381         return hard_iface->wifi_flags != 0;
 382 }
 383
 384 /**
 385  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 386  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 387  * @orig_addr: the originator of this packet
 388  * @orig_neigh: originator address of the forwarder we just got the packet from
 389  *  (NULL if we originated)
 390  *
 391  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 392  *
 393  * Return:
 394  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 395  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 396  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 397  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 398  */
 399 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 400                                u8 *orig_addr, u8 *orig_neigh)
 401 {
 402         struct batadv_hardif_neigh_node *hardif_neigh;
 403         struct hlist_node *first;
 404         int ret = BATADV_HARDIF_BCAST_OK;
 405
 406         rcu_read_lock();
 407
 408         /* 0 neighbors -> no (re)broadcast */
 409         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 410         if (!first) {
 411                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 412                 goto out;
 413         }
 414
 415         /* >1 neighbors -> (re)broadcast */
 416         if (rcu_dereference(hlist_next_rcu(first)))
 417                 goto out;
 418
 419         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 420                                    list);
 421
 422         /* 1 neighbor, is the originator -> no rebroadcast */
 423         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 424                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 425         /* 1 neighbor, is the one we received from -> no rebroadcast */
 426         } else if (orig_neigh &&
 427                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 428                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 429         }
 430
 431 out:
 432         rcu_read_unlock();
 433         return ret;
 434 }
 435
 436 static struct batadv_hard_iface *
 437 batadv_hardif_get_active(const struct net_device *soft_iface)
 438 {
 439         struct batadv_hard_iface *hard_iface;
 440
 441         rcu_read_lock();
 442         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 443                 if (hard_iface->soft_iface != soft_iface)
 444                         continue;
 445
 446                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 447                     kref_get_unless_zero(&hard_iface->refcount))
 448                         goto out;
 449         }
 450
 451         hard_iface = NULL;
 452
 453 out:
 454         rcu_read_unlock();
 455         return hard_iface;
 456 }
 457
 458 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 459                                           struct batadv_hard_iface *oldif)
 460 {
 461         struct batadv_hard_iface *primary_if;
 462
 463         primary_if = batadv_primary_if_get_selected(bat_priv);
 464         if (!primary_if)
 465                 goto out;
 466
 467         batadv_dat_init_own_addr(bat_priv, primary_if);
 468         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 469 out:
 470         batadv_hardif_put(primary_if);
 471 }
 472
 473 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 474                                      struct batadv_hard_iface *new_hard_iface)
 475 {
 476         struct batadv_hard_iface *curr_hard_iface;
 477
 478         ASSERT_RTNL();
 479
 480         if (new_hard_iface)
 481                 kref_get(&new_hard_iface->refcount);
 482
 483         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 484                                               new_hard_iface, 1);
 485
 486         if (!new_hard_iface)
 487                 goto out;
 488
 489         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 490         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 491
 492 out:
 493         batadv_hardif_put(curr_hard_iface);
 494 }
 495
 496 static bool
 497 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 498 {
 499         if (hard_iface->net_dev->flags & IFF_UP)
 500                 return true;
 501
 502         return false;
 503 }
 504
 505 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 506 {
 507         const struct batadv_hard_iface *hard_iface;
 508
 509         rcu_read_lock();
 510         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 511                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 512                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 513                         continue;
 514
 515                 if (hard_iface->net_dev == net_dev)
 516                         continue;
 517
 518                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 519                                         net_dev->dev_addr))
 520                         continue;
 521
 522                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 523                         net_dev->dev_addr, hard_iface->net_dev->name);
 524                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 525         }
 526         rcu_read_unlock();
 527 }
 528
 529 /**
 530  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 531  * @soft_iface: netdev struct of the mesh interface
 532  */
 533 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 534 {
 535         const struct batadv_hard_iface *hard_iface;
 536         unsigned short lower_header_len = ETH_HLEN;
 537         unsigned short lower_headroom = 0;
 538         unsigned short lower_tailroom = 0;
 539         unsigned short needed_headroom;
 540
 541         rcu_read_lock();
 542         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 543                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 544                         continue;
 545
 546                 if (hard_iface->soft_iface != soft_iface)
 547                         continue;
 548
 549                 lower_header_len = max_t(unsigned short, lower_header_len,
 550                                          hard_iface->net_dev->hard_header_len);
 551
 552                 lower_headroom = max_t(unsigned short, lower_headroom,
 553                                        hard_iface->net_dev->needed_headroom);
 554
 555                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 556                                        hard_iface->net_dev->needed_tailroom);
 557         }
 558         rcu_read_unlock();
 559
 560         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 561         needed_headroom += batadv_max_header_len();
 562
 563         /* fragmentation headers don't strip the unicast/... header */
 564         needed_headroom += sizeof(struct batadv_frag_packet);
 565
 566         soft_iface->needed_headroom = needed_headroom;
 567         soft_iface->needed_tailroom = lower_tailroom;
 568 }
 569
 570 /**
 571  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 572  * @soft_iface: netdev struct of the soft interface
 573  *
 574  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 575  *  slave interfaces)
 576  */
 577 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 578 {
 579         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 580         const struct batadv_hard_iface *hard_iface;
 581         int min_mtu = INT_MAX;
 582
 583         rcu_read_lock();
 584         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 585                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 586                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 587                         continue;
 588
 589                 if (hard_iface->soft_iface != soft_iface)
 590                         continue;
 591
 592                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 593         }
 594         rcu_read_unlock();
 595
 596         if (atomic_read(&bat_priv->fragmentation) == 0)
 597                 goto out;
 598
 599         /* with fragmentation enabled the maximum size of internally generated
 600          * packets such as translation table exchanges or tvlv containers, etc
 601          * has to be calculated
 602          */
 603         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 604         min_mtu -= sizeof(struct batadv_frag_packet);
 605         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 606
 607 out:
 608         /* report to the other components the maximum amount of bytes that
 609          * batman-adv can send over the wire (without considering the payload
 610          * overhead). For example, this value is used by TT to compute the
 611          * maximum local table size
 612          */
 613         atomic_set(&bat_priv->packet_size_max, min_mtu);
 614
 615         /* the real soft-interface MTU is computed by removing the payload
 616          * overhead from the maximum amount of bytes that was just computed.
 617          *
 618          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 619          */
 620         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 621 }
 622
 623 /**
 624  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 625  *  MTU appeared
 626  * @soft_iface: netdev struct of the soft interface
 627  */
 628 void batadv_update_min_mtu(struct net_device *soft_iface)
 629 {
 630         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 631
 632         /* Check if the local translate table should be cleaned up to match a
 633          * new (and smaller) MTU.
 634          */
 635         batadv_tt_local_resize_to_mtu(soft_iface);
 636 }
 637
 638 static void
 639 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 640 {
 641         struct batadv_priv *bat_priv;
 642         struct batadv_hard_iface *primary_if = NULL;
 643
 644         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 645                 goto out;
 646
 647         bat_priv = netdev_priv(hard_iface->soft_iface);
 648
 649         bat_priv->algo_ops->iface.update_mac(hard_iface);
 650         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 651
 652         /* the first active interface becomes our primary interface or
 653          * the next active interface after the old primary interface was removed
 654          */
 655         primary_if = batadv_primary_if_get_selected(bat_priv);
 656         if (!primary_if)
 657                 batadv_primary_if_select(bat_priv, hard_iface);
 658
 659         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 660                     hard_iface->net_dev->name);
 661
 662         batadv_update_min_mtu(hard_iface->soft_iface);
 663
 664         if (bat_priv->algo_ops->iface.activate)
 665                 bat_priv->algo_ops->iface.activate(hard_iface);
 666
 667 out:
 668         batadv_hardif_put(primary_if);
 669 }
 670
 671 static void
 672 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 673 {
 674         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 675             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 676                 return;
 677
 678         hard_iface->if_status = BATADV_IF_INACTIVE;
 679
 680         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 681                     hard_iface->net_dev->name);
 682
 683         batadv_update_min_mtu(hard_iface->soft_iface);
 684 }
 685
 686 /**
 687  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 688  * @hard_iface: hard interface to add to soft interface
 689  * @soft_iface: netdev struct of the mesh interface
 690  *
 691  * Return: 0 on success or negative error number in case of failure
 692  */
 693 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 694                                    struct net_device *soft_iface)
 695 {
 696         struct batadv_priv *bat_priv;
 697         __be16 ethertype = htons(ETH_P_BATMAN);
 698         int max_header_len = batadv_max_header_len();
 699         int ret;
 700
 701         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 702                 goto out;
 703
 704         kref_get(&hard_iface->refcount);
 705
 706         dev_hold(soft_iface);
 707         hard_iface->soft_iface = soft_iface;
 708         bat_priv = netdev_priv(hard_iface->soft_iface);
 709
 710         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 711                                            soft_iface, NULL, NULL, NULL);
 712         if (ret)
 713                 goto err_dev;
 714
 715         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 716         if (ret < 0)
 717                 goto err_upper;
 718
 719         hard_iface->if_status = BATADV_IF_INACTIVE;
 720
 721         kref_get(&hard_iface->refcount);
 722         hard_iface->batman_adv_ptype.type = ethertype;
 723         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 724         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 725         dev_add_pack(&hard_iface->batman_adv_ptype);
 726
 727         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 728                     hard_iface->net_dev->name);
 729
 730         if (atomic_read(&bat_priv->fragmentation) &&
 731             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 732                 batadv_info(hard_iface->soft_iface,
 733                             "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",
 734                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 735                             ETH_DATA_LEN + max_header_len);
 736
 737         if (!atomic_read(&bat_priv->fragmentation) &&
 738             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 739                 batadv_info(hard_iface->soft_iface,
 740                             "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",
 741                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 742                             ETH_DATA_LEN + max_header_len);
 743
 744         if (batadv_hardif_is_iface_up(hard_iface))
 745                 batadv_hardif_activate_interface(hard_iface);
 746         else
 747                 batadv_err(hard_iface->soft_iface,
 748                            "Not using interface %s (retrying later): interface not active\n",
 749                            hard_iface->net_dev->name);
 750
 751         batadv_hardif_recalc_extra_skbroom(soft_iface);
 752
 753         if (bat_priv->algo_ops->iface.enabled)
 754                 bat_priv->algo_ops->iface.enabled(hard_iface);
 755
 756 out:
 757         return 0;
 758
 759 err_upper:
 760         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 761 err_dev:
 762         hard_iface->soft_iface = NULL;
 763         dev_put(soft_iface);
 764         batadv_hardif_put(hard_iface);
 765         return ret;
 766 }
 767
 768 /**
 769  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 770  * @soft_iface: soft interface to check
 771  *
 772  * This function is only using RCU for locking - the result can therefore be
 773  * off when another function is modifying the list at the same time. The
 774  * caller can use the rtnl_lock to make sure that the count is accurate.
 775  *
 776  * Return: number of connected/enslaved hard interfaces
 777  */
 778 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 779 {
 780         struct batadv_hard_iface *hard_iface;
 781         size_t count = 0;
 782
 783         rcu_read_lock();
 784         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 785                 if (hard_iface->soft_iface != soft_iface)
 786                         continue;
 787
 788                 count++;
 789         }
 790         rcu_read_unlock();
 791
 792         return count;
 793 }
 794
 795 /**
 796  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 797  * @hard_iface: hard interface to be removed
 798  */
 799 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
 800 {
 801         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 802         struct batadv_hard_iface *primary_if = NULL;
 803
 804         batadv_hardif_deactivate_interface(hard_iface);
 805
 806         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 807                 goto out;
 808
 809         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 810                     hard_iface->net_dev->name);
 811         dev_remove_pack(&hard_iface->batman_adv_ptype);
 812         batadv_hardif_put(hard_iface);
 813
 814         primary_if = batadv_primary_if_get_selected(bat_priv);
 815         if (hard_iface == primary_if) {
 816                 struct batadv_hard_iface *new_if;
 817
 818                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 819                 batadv_primary_if_select(bat_priv, new_if);
 820
 821                 batadv_hardif_put(new_if);
 822         }
 823
 824         bat_priv->algo_ops->iface.disable(hard_iface);
 825         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 826
 827         /* delete all references to this hard_iface */
 828         batadv_purge_orig_ref(bat_priv);
 829         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 830         dev_put(hard_iface->soft_iface);
 831
 832         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 833         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 834
 835         /* nobody uses this interface anymore */
 836         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1)
 837                 batadv_gw_check_client_stop(bat_priv);
 838
 839         hard_iface->soft_iface = NULL;
 840         batadv_hardif_put(hard_iface);
 841
 842 out:
 843         batadv_hardif_put(primary_if);
 844 }
 845
 846 static struct batadv_hard_iface *
 847 batadv_hardif_add_interface(struct net_device *net_dev)
 848 {
 849         struct batadv_hard_iface *hard_iface;
 850
 851         ASSERT_RTNL();
 852
 853         if (!batadv_is_valid_iface(net_dev))
 854                 goto out;
 855
 856         dev_hold(net_dev);
 857
 858         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 859         if (!hard_iface)
 860                 goto release_dev;
 861
 862         hard_iface->net_dev = net_dev;
 863         hard_iface->soft_iface = NULL;
 864         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 865
 866         INIT_LIST_HEAD(&hard_iface->list);
 867         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 868
 869         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 870         spin_lock_init(&hard_iface->neigh_list_lock);
 871         kref_init(&hard_iface->refcount);
 872
 873         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 874         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 875         if (batadv_is_wifi_hardif(hard_iface))
 876                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 877
 878         atomic_set(&hard_iface->hop_penalty, 0);
 879
 880         batadv_v_hardif_init(hard_iface);
 881
 882         batadv_check_known_mac_addr(hard_iface->net_dev);
 883         kref_get(&hard_iface->refcount);
 884         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 885         batadv_hardif_generation++;
 886
 887         return hard_iface;
 888
 889 release_dev:
 890         dev_put(net_dev);
 891 out:
 892         return NULL;
 893 }
 894
 895 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 896 {
 897         ASSERT_RTNL();
 898
 899         /* first deactivate interface */
 900         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 901                 batadv_hardif_disable_interface(hard_iface);
 902
 903         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 904                 return;
 905
 906         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 907         batadv_hardif_put(hard_iface);
 908 }
 909
 910 /**
 911  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 912  * @event: NETDEV_* event to handle
 913  * @net_dev: net_device which generated an event
 914  *
 915  * Return: NOTIFY_* result
 916  */
 917 static int batadv_hard_if_event_softif(unsigned long event,
 918                                        struct net_device *net_dev)
 919 {
 920         struct batadv_priv *bat_priv;
 921
 922         switch (event) {
 923         case NETDEV_REGISTER:
 924                 bat_priv = netdev_priv(net_dev);
 925                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 926                 break;
 927         }
 928
 929         return NOTIFY_DONE;
 930 }
 931
 932 static int batadv_hard_if_event(struct notifier_block *this,
 933                                 unsigned long event, void *ptr)
 934 {
 935         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 936         struct batadv_hard_iface *hard_iface;
 937         struct batadv_hard_iface *primary_if = NULL;
 938         struct batadv_priv *bat_priv;
 939
 940         if (batadv_softif_is_valid(net_dev))
 941                 return batadv_hard_if_event_softif(event, net_dev);
 942
 943         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 944         if (!hard_iface && (event == NETDEV_REGISTER ||
 945                             event == NETDEV_POST_TYPE_CHANGE))
 946                 hard_iface = batadv_hardif_add_interface(net_dev);
 947
 948         if (!hard_iface)
 949                 goto out;
 950
 951         switch (event) {
 952         case NETDEV_UP:
 953                 batadv_hardif_activate_interface(hard_iface);
 954                 break;
 955         case NETDEV_GOING_DOWN:
 956         case NETDEV_DOWN:
 957                 batadv_hardif_deactivate_interface(hard_iface);
 958                 break;
 959         case NETDEV_UNREGISTER:
 960         case NETDEV_PRE_TYPE_CHANGE:
 961                 list_del_rcu(&hard_iface->list);
 962                 batadv_hardif_generation++;
 963
 964                 batadv_hardif_remove_interface(hard_iface);
 965                 break;
 966         case NETDEV_CHANGEMTU:
 967                 if (hard_iface->soft_iface)
 968                         batadv_update_min_mtu(hard_iface->soft_iface);
 969                 break;
 970         case NETDEV_CHANGEADDR:
 971                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 972                         goto hardif_put;
 973
 974                 batadv_check_known_mac_addr(hard_iface->net_dev);
 975
 976                 bat_priv = netdev_priv(hard_iface->soft_iface);
 977                 bat_priv->algo_ops->iface.update_mac(hard_iface);
 978
 979                 primary_if = batadv_primary_if_get_selected(bat_priv);
 980                 if (!primary_if)
 981                         goto hardif_put;
 982
 983                 if (hard_iface == primary_if)
 984                         batadv_primary_if_update_addr(bat_priv, NULL);
 985                 break;
 986         case NETDEV_CHANGEUPPER:
 987                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 988                 if (batadv_is_wifi_hardif(hard_iface))
 989                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 990                 break;
 991         default:
 992                 break;
 993         }
 994
 995 hardif_put:
 996         batadv_hardif_put(hard_iface);
 997 out:
 998         batadv_hardif_put(primary_if);
 999         return NOTIFY_DONE;
1000 }
1001
1002 struct notifier_block batadv_hard_if_notifier = {
1003         .notifier_call = batadv_hard_if_event,
1004 };