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/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 "debugfs.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 "sysfs.h"
  42 #include "translation-table.h"
  43
  44 /**
  45  * batadv_hardif_release() - release hard interface from lists and queue for
  46  *  free after rcu grace period
  47  * @ref: kref pointer of the hard interface
  48  */
  49 void batadv_hardif_release(struct kref *ref)
  50 {
  51         struct batadv_hard_iface *hard_iface;
  52
  53         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  54         dev_put(hard_iface->net_dev);
  55
  56         kfree_rcu(hard_iface, rcu);
  57 }
  58
  59 /**
  60  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  61  * @net_dev: net_device to search for
  62  *
  63  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  64  */
  65 struct batadv_hard_iface *
  66 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  67 {
  68         struct batadv_hard_iface *hard_iface;
  69
  70         rcu_read_lock();
  71         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  72                 if (hard_iface->net_dev == net_dev &&
  73                     kref_get_unless_zero(&hard_iface->refcount))
  74                         goto out;
  75         }
  76
  77         hard_iface = NULL;
  78
  79 out:
  80         rcu_read_unlock();
  81         return hard_iface;
  82 }
  83
  84 /**
  85  * batadv_getlink_net() - return link net namespace (of use fallback)
  86  * @netdev: net_device to check
  87  * @fallback_net: return in case get_link_net is not available for @netdev
  88  *
  89  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  90  */
  91 static struct net *batadv_getlink_net(const struct net_device *netdev,
  92                                       struct net *fallback_net)
  93 {
  94         if (!netdev->rtnl_link_ops)
  95                 return fallback_net;
  96
  97         if (!netdev->rtnl_link_ops->get_link_net)
  98                 return fallback_net;
  99
 100         return netdev->rtnl_link_ops->get_link_net(netdev);
 101 }
 102
 103 /**
 104  * batadv_mutual_parents() - check if two devices are each others parent
 105  * @dev1: 1st net dev
 106  * @net1: 1st devices netns
 107  * @dev2: 2nd net dev
 108  * @net2: 2nd devices netns
 109  *
 110  * veth devices come in pairs and each is the parent of the other!
 111  *
 112  * Return: true if the devices are each others parent, otherwise false
 113  */
 114 static bool batadv_mutual_parents(const struct net_device *dev1,
 115                                   struct net *net1,
 116                                   const struct net_device *dev2,
 117                                   struct net *net2)
 118 {
 119         int dev1_parent_iflink = dev_get_iflink(dev1);
 120         int dev2_parent_iflink = dev_get_iflink(dev2);
 121         const struct net *dev1_parent_net;
 122         const struct net *dev2_parent_net;
 123
 124         dev1_parent_net = batadv_getlink_net(dev1, net1);
 125         dev2_parent_net = batadv_getlink_net(dev2, net2);
 126
 127         if (!dev1_parent_iflink || !dev2_parent_iflink)
 128                 return false;
 129
 130         return (dev1_parent_iflink == dev2->ifindex) &&
 131                (dev2_parent_iflink == dev1->ifindex) &&
 132                net_eq(dev1_parent_net, net2) &&
 133                net_eq(dev2_parent_net, net1);
 134 }
 135
 136 /**
 137  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 138  * @net_dev: the device to check
 139  *
 140  * If the user creates any virtual device on top of a batman-adv interface, it
 141  * is important to prevent this new interface from being used to create a new
 142  * mesh network (this behaviour would lead to a batman-over-batman
 143  * configuration). This function recursively checks all the fathers of the
 144  * device passed as argument looking for a batman-adv soft interface.
 145  *
 146  * Return: true if the device is descendant of a batman-adv mesh interface (or
 147  * if it is a batman-adv interface itself), false otherwise
 148  */
 149 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 150 {
 151         struct net *net = dev_net(net_dev);
 152         struct net_device *parent_dev;
 153         struct net *parent_net;
 154         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         /* no more parents..stop recursion */
 161         if (dev_get_iflink(net_dev) == 0 ||
 162             dev_get_iflink(net_dev) == net_dev->ifindex)
 163                 return false;
 164
 165         parent_net = batadv_getlink_net(net_dev, net);
 166
 167         /* recurse over the parent device */
 168         parent_dev = __dev_get_by_index((struct net *)parent_net,
 169                                         dev_get_iflink(net_dev));
 170         /* if we got a NULL parent_dev there is something broken.. */
 171         if (!parent_dev) {
 172                 pr_err("Cannot find parent device\n");
 173                 return false;
 174         }
 175
 176         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 177                 return false;
 178
 179         ret = batadv_is_on_batman_iface(parent_dev);
 180
 181         return ret;
 182 }
 183
 184 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 185 {
 186         if (net_dev->flags & IFF_LOOPBACK)
 187                 return false;
 188
 189         if (net_dev->type != ARPHRD_ETHER)
 190                 return false;
 191
 192         if (net_dev->addr_len != ETH_ALEN)
 193                 return false;
 194
 195         /* no batman over batman */
 196         if (batadv_is_on_batman_iface(net_dev))
 197                 return false;
 198
 199         return true;
 200 }
 201
 202 /**
 203  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 204  *  interface on top of another 'real' interface
 205  * @netdev: the device to check
 206  *
 207  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 208  * instead of this.
 209  *
 210  * Return: the 'real' net device or the original net device and NULL in case
 211  *  of an error.
 212  */
 213 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 214 {
 215         struct batadv_hard_iface *hard_iface = NULL;
 216         struct net_device *real_netdev = NULL;
 217         struct net *real_net;
 218         struct net *net;
 219         int ifindex;
 220
 221         ASSERT_RTNL();
 222
 223         if (!netdev)
 224                 return NULL;
 225
 226         if (netdev->ifindex == dev_get_iflink(netdev)) {
 227                 dev_hold(netdev);
 228                 return netdev;
 229         }
 230
 231         hard_iface = batadv_hardif_get_by_netdev(netdev);
 232         if (!hard_iface || !hard_iface->soft_iface)
 233                 goto out;
 234
 235         net = dev_net(hard_iface->soft_iface);
 236         ifindex = dev_get_iflink(netdev);
 237         real_net = batadv_getlink_net(netdev, net);
 238         real_netdev = dev_get_by_index(real_net, ifindex);
 239
 240 out:
 241         if (hard_iface)
 242                 batadv_hardif_put(hard_iface);
 243         return real_netdev;
 244 }
 245
 246 /**
 247  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 248  *  interface on top of another 'real' interface
 249  * @net_device: the device to check
 250  *
 251  * Return: the 'real' net device or the original net device and NULL in case
 252  *  of an error.
 253  */
 254 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 255 {
 256         struct net_device *real_netdev;
 257
 258         rtnl_lock();
 259         real_netdev = batadv_get_real_netdevice(net_device);
 260         rtnl_unlock();
 261
 262         return real_netdev;
 263 }
 264
 265 /**
 266  * batadv_is_wext_netdev() - check if the given net_device struct is a
 267  *  wext wifi interface
 268  * @net_device: the device to check
 269  *
 270  * Return: true if the net device is a wext wireless device, false
 271  *  otherwise.
 272  */
 273 static bool batadv_is_wext_netdev(struct net_device *net_device)
 274 {
 275         if (!net_device)
 276                 return false;
 277
 278 #ifdef CONFIG_WIRELESS_EXT
 279         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 280          * check for wireless_handlers != NULL
 281          */
 282         if (net_device->wireless_handlers)
 283                 return true;
 284 #endif
 285
 286         return false;
 287 }
 288
 289 /**
 290  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 291  *  cfg80211 wifi interface
 292  * @net_device: the device to check
 293  *
 294  * Return: true if the net device is a cfg80211 wireless device, false
 295  *  otherwise.
 296  */
 297 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 298 {
 299         if (!net_device)
 300                 return false;
 301
 302         /* cfg80211 drivers have to set ieee80211_ptr */
 303         if (net_device->ieee80211_ptr)
 304                 return true;
 305
 306         return false;
 307 }
 308
 309 /**
 310  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 311  * @net_device: the device to check
 312  *
 313  * Return: batadv_hard_iface_wifi_flags flags of the device
 314  */
 315 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 316 {
 317         u32 wifi_flags = 0;
 318         struct net_device *real_netdev;
 319
 320         if (batadv_is_wext_netdev(net_device))
 321                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 322
 323         if (batadv_is_cfg80211_netdev(net_device))
 324                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 325
 326         real_netdev = batadv_get_real_netdevice(net_device);
 327         if (!real_netdev)
 328                 return wifi_flags;
 329
 330         if (real_netdev == net_device)
 331                 goto out;
 332
 333         if (batadv_is_wext_netdev(real_netdev))
 334                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 335
 336         if (batadv_is_cfg80211_netdev(real_netdev))
 337                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 338
 339 out:
 340         dev_put(real_netdev);
 341         return wifi_flags;
 342 }
 343
 344 /**
 345  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 346  *  interface
 347  * @hard_iface: the device to check
 348  *
 349  * Return: true if the net device is a cfg80211 wireless device, false
 350  *  otherwise.
 351  */
 352 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 353 {
 354         u32 allowed_flags = 0;
 355
 356         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 357         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 358
 359         return !!(hard_iface->wifi_flags & allowed_flags);
 360 }
 361
 362 /**
 363  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 364  * @hard_iface: the device to check
 365  *
 366  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 367  */
 368 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 369 {
 370         if (!hard_iface)
 371                 return false;
 372
 373         return hard_iface->wifi_flags != 0;
 374 }
 375
 376 /**
 377  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 378  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 379  * @orig_addr: the originator of this packet
 380  * @orig_neigh: originator address of the forwarder we just got the packet from
 381  *  (NULL if we originated)
 382  *
 383  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 384  *
 385  * Return:
 386  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 387  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 388  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 389  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 390  */
 391 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 392                                u8 *orig_addr, u8 *orig_neigh)
 393 {
 394         struct batadv_hardif_neigh_node *hardif_neigh;
 395         struct hlist_node *first;
 396         int ret = BATADV_HARDIF_BCAST_OK;
 397
 398         rcu_read_lock();
 399
 400         /* 0 neighbors -> no (re)broadcast */
 401         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 402         if (!first) {
 403                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 404                 goto out;
 405         }
 406
 407         /* >1 neighbors -> (re)brodcast */
 408         if (rcu_dereference(hlist_next_rcu(first)))
 409                 goto out;
 410
 411         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 412                                    list);
 413
 414         /* 1 neighbor, is the originator -> no rebroadcast */
 415         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 416                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 417         /* 1 neighbor, is the one we received from -> no rebroadcast */
 418         } else if (orig_neigh &&
 419                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 420                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 421         }
 422
 423 out:
 424         rcu_read_unlock();
 425         return ret;
 426 }
 427
 428 static struct batadv_hard_iface *
 429 batadv_hardif_get_active(const struct net_device *soft_iface)
 430 {
 431         struct batadv_hard_iface *hard_iface;
 432
 433         rcu_read_lock();
 434         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 435                 if (hard_iface->soft_iface != soft_iface)
 436                         continue;
 437
 438                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 439                     kref_get_unless_zero(&hard_iface->refcount))
 440                         goto out;
 441         }
 442
 443         hard_iface = NULL;
 444
 445 out:
 446         rcu_read_unlock();
 447         return hard_iface;
 448 }
 449
 450 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 451                                           struct batadv_hard_iface *oldif)
 452 {
 453         struct batadv_hard_iface *primary_if;
 454
 455         primary_if = batadv_primary_if_get_selected(bat_priv);
 456         if (!primary_if)
 457                 goto out;
 458
 459         batadv_dat_init_own_addr(bat_priv, primary_if);
 460         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 461 out:
 462         if (primary_if)
 463                 batadv_hardif_put(primary_if);
 464 }
 465
 466 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 467                                      struct batadv_hard_iface *new_hard_iface)
 468 {
 469         struct batadv_hard_iface *curr_hard_iface;
 470
 471         ASSERT_RTNL();
 472
 473         if (new_hard_iface)
 474                 kref_get(&new_hard_iface->refcount);
 475
 476         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 477                                               new_hard_iface, 1);
 478
 479         if (!new_hard_iface)
 480                 goto out;
 481
 482         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 483         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 484
 485 out:
 486         if (curr_hard_iface)
 487                 batadv_hardif_put(curr_hard_iface);
 488 }
 489
 490 static bool
 491 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 492 {
 493         if (hard_iface->net_dev->flags & IFF_UP)
 494                 return true;
 495
 496         return false;
 497 }
 498
 499 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 500 {
 501         const struct batadv_hard_iface *hard_iface;
 502
 503         rcu_read_lock();
 504         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 505                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 506                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 507                         continue;
 508
 509                 if (hard_iface->net_dev == net_dev)
 510                         continue;
 511
 512                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 513                                         net_dev->dev_addr))
 514                         continue;
 515
 516                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 517                         net_dev->dev_addr, hard_iface->net_dev->name);
 518                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 519         }
 520         rcu_read_unlock();
 521 }
 522
 523 /**
 524  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 525  * @soft_iface: netdev struct of the mesh interface
 526  */
 527 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 528 {
 529         const struct batadv_hard_iface *hard_iface;
 530         unsigned short lower_header_len = ETH_HLEN;
 531         unsigned short lower_headroom = 0;
 532         unsigned short lower_tailroom = 0;
 533         unsigned short needed_headroom;
 534
 535         rcu_read_lock();
 536         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 537                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 538                         continue;
 539
 540                 if (hard_iface->soft_iface != soft_iface)
 541                         continue;
 542
 543                 lower_header_len = max_t(unsigned short, lower_header_len,
 544                                          hard_iface->net_dev->hard_header_len);
 545
 546                 lower_headroom = max_t(unsigned short, lower_headroom,
 547                                        hard_iface->net_dev->needed_headroom);
 548
 549                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 550                                        hard_iface->net_dev->needed_tailroom);
 551         }
 552         rcu_read_unlock();
 553
 554         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 555         needed_headroom += batadv_max_header_len();
 556
 557         soft_iface->needed_headroom = needed_headroom;
 558         soft_iface->needed_tailroom = lower_tailroom;
 559 }
 560
 561 /**
 562  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 563  * @soft_iface: netdev struct of the soft interface
 564  *
 565  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 566  *  slave interfaces)
 567  */
 568 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 569 {
 570         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 571         const struct batadv_hard_iface *hard_iface;
 572         int min_mtu = INT_MAX;
 573
 574         rcu_read_lock();
 575         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 576                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 577                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 578                         continue;
 579
 580                 if (hard_iface->soft_iface != soft_iface)
 581                         continue;
 582
 583                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 584         }
 585         rcu_read_unlock();
 586
 587         if (atomic_read(&bat_priv->fragmentation) == 0)
 588                 goto out;
 589
 590         /* with fragmentation enabled the maximum size of internally generated
 591          * packets such as translation table exchanges or tvlv containers, etc
 592          * has to be calculated
 593          */
 594         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 595         min_mtu -= sizeof(struct batadv_frag_packet);
 596         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 597
 598 out:
 599         /* report to the other components the maximum amount of bytes that
 600          * batman-adv can send over the wire (without considering the payload
 601          * overhead). For example, this value is used by TT to compute the
 602          * maximum local table size
 603          */
 604         atomic_set(&bat_priv->packet_size_max, min_mtu);
 605
 606         /* the real soft-interface MTU is computed by removing the payload
 607          * overhead from the maximum amount of bytes that was just computed.
 608          *
 609          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 610          */
 611         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 612 }
 613
 614 /**
 615  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 616  *  MTU appeared
 617  * @soft_iface: netdev struct of the soft interface
 618  */
 619 void batadv_update_min_mtu(struct net_device *soft_iface)
 620 {
 621         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 622
 623         /* Check if the local translate table should be cleaned up to match a
 624          * new (and smaller) MTU.
 625          */
 626         batadv_tt_local_resize_to_mtu(soft_iface);
 627 }
 628
 629 static void
 630 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 631 {
 632         struct batadv_priv *bat_priv;
 633         struct batadv_hard_iface *primary_if = NULL;
 634
 635         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 636                 goto out;
 637
 638         bat_priv = netdev_priv(hard_iface->soft_iface);
 639
 640         bat_priv->algo_ops->iface.update_mac(hard_iface);
 641         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 642
 643         /* the first active interface becomes our primary interface or
 644          * the next active interface after the old primary interface was removed
 645          */
 646         primary_if = batadv_primary_if_get_selected(bat_priv);
 647         if (!primary_if)
 648                 batadv_primary_if_select(bat_priv, hard_iface);
 649
 650         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 651                     hard_iface->net_dev->name);
 652
 653         batadv_update_min_mtu(hard_iface->soft_iface);
 654
 655         if (bat_priv->algo_ops->iface.activate)
 656                 bat_priv->algo_ops->iface.activate(hard_iface);
 657
 658 out:
 659         if (primary_if)
 660                 batadv_hardif_put(primary_if);
 661 }
 662
 663 static void
 664 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 665 {
 666         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 667             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 668                 return;
 669
 670         hard_iface->if_status = BATADV_IF_INACTIVE;
 671
 672         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 673                     hard_iface->net_dev->name);
 674
 675         batadv_update_min_mtu(hard_iface->soft_iface);
 676 }
 677
 678 /**
 679  * batadv_master_del_slave() - remove hard_iface from the current master iface
 680  * @slave: the interface enslaved in another master
 681  * @master: the master from which slave has to be removed
 682  *
 683  * Invoke ndo_del_slave on master passing slave as argument. In this way the
 684  * slave is free'd and the master can correctly change its internal state.
 685  *
 686  * Return: 0 on success, a negative value representing the error otherwise
 687  */
 688 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 689                                    struct net_device *master)
 690 {
 691         int ret;
 692
 693         if (!master)
 694                 return 0;
 695
 696         ret = -EBUSY;
 697         if (master->netdev_ops->ndo_del_slave)
 698                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 699
 700         return ret;
 701 }
 702
 703 /**
 704  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 705  * @hard_iface: hard interface to add to soft interface
 706  * @net: the applicable net namespace
 707  * @iface_name: name of the soft interface
 708  *
 709  * Return: 0 on success or negative error number in case of failure
 710  */
 711 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 712                                    struct net *net, const char *iface_name)
 713 {
 714         struct batadv_priv *bat_priv;
 715         struct net_device *soft_iface, *master;
 716         __be16 ethertype = htons(ETH_P_BATMAN);
 717         int max_header_len = batadv_max_header_len();
 718         int ret;
 719
 720         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 721                 goto out;
 722
 723         kref_get(&hard_iface->refcount);
 724
 725         soft_iface = dev_get_by_name(net, iface_name);
 726
 727         if (!soft_iface) {
 728                 soft_iface = batadv_softif_create(net, iface_name);
 729
 730                 if (!soft_iface) {
 731                         ret = -ENOMEM;
 732                         goto err;
 733                 }
 734
 735                 /* dev_get_by_name() increases the reference counter for us */
 736                 dev_hold(soft_iface);
 737         }
 738
 739         if (!batadv_softif_is_valid(soft_iface)) {
 740                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 741                        soft_iface->name);
 742                 ret = -EINVAL;
 743                 goto err_dev;
 744         }
 745
 746         /* check if the interface is enslaved in another virtual one and
 747          * in that case unlink it first
 748          */
 749         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 750         ret = batadv_master_del_slave(hard_iface, master);
 751         if (ret)
 752                 goto err_dev;
 753
 754         hard_iface->soft_iface = soft_iface;
 755         bat_priv = netdev_priv(hard_iface->soft_iface);
 756
 757         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 758                                            soft_iface, NULL, NULL, NULL);
 759         if (ret)
 760                 goto err_dev;
 761
 762         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 763         if (ret < 0)
 764                 goto err_upper;
 765
 766         hard_iface->if_status = BATADV_IF_INACTIVE;
 767
 768         kref_get(&hard_iface->refcount);
 769         hard_iface->batman_adv_ptype.type = ethertype;
 770         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 771         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 772         dev_add_pack(&hard_iface->batman_adv_ptype);
 773
 774         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 775                     hard_iface->net_dev->name);
 776
 777         if (atomic_read(&bat_priv->fragmentation) &&
 778             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 779                 batadv_info(hard_iface->soft_iface,
 780                             "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",
 781                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 782                             ETH_DATA_LEN + max_header_len);
 783
 784         if (!atomic_read(&bat_priv->fragmentation) &&
 785             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 786                 batadv_info(hard_iface->soft_iface,
 787                             "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",
 788                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 789                             ETH_DATA_LEN + max_header_len);
 790
 791         if (batadv_hardif_is_iface_up(hard_iface))
 792                 batadv_hardif_activate_interface(hard_iface);
 793         else
 794                 batadv_err(hard_iface->soft_iface,
 795                            "Not using interface %s (retrying later): interface not active\n",
 796                            hard_iface->net_dev->name);
 797
 798         batadv_hardif_recalc_extra_skbroom(soft_iface);
 799
 800         if (bat_priv->algo_ops->iface.enabled)
 801                 bat_priv->algo_ops->iface.enabled(hard_iface);
 802
 803 out:
 804         return 0;
 805
 806 err_upper:
 807         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 808 err_dev:
 809         hard_iface->soft_iface = NULL;
 810         dev_put(soft_iface);
 811 err:
 812         batadv_hardif_put(hard_iface);
 813         return ret;
 814 }
 815
 816 /**
 817  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 818  * @soft_iface: soft interface to check
 819  *
 820  * This function is only using RCU for locking - the result can therefore be
 821  * off when another function is modifying the list at the same time. The
 822  * caller can use the rtnl_lock to make sure that the count is accurate.
 823  *
 824  * Return: number of connected/enslaved hard interfaces
 825  */
 826 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 827 {
 828         struct batadv_hard_iface *hard_iface;
 829         size_t count = 0;
 830
 831         rcu_read_lock();
 832         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 833                 if (hard_iface->soft_iface != soft_iface)
 834                         continue;
 835
 836                 count++;
 837         }
 838         rcu_read_unlock();
 839
 840         return count;
 841 }
 842
 843 /**
 844  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 845  * @hard_iface: hard interface to be removed
 846  * @autodel: whether to delete soft interface when it doesn't contain any other
 847  *  slave interfaces
 848  */
 849 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 850                                      enum batadv_hard_if_cleanup autodel)
 851 {
 852         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 853         struct batadv_hard_iface *primary_if = NULL;
 854
 855         batadv_hardif_deactivate_interface(hard_iface);
 856
 857         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 858                 goto out;
 859
 860         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 861                     hard_iface->net_dev->name);
 862         dev_remove_pack(&hard_iface->batman_adv_ptype);
 863         batadv_hardif_put(hard_iface);
 864
 865         primary_if = batadv_primary_if_get_selected(bat_priv);
 866         if (hard_iface == primary_if) {
 867                 struct batadv_hard_iface *new_if;
 868
 869                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 870                 batadv_primary_if_select(bat_priv, new_if);
 871
 872                 if (new_if)
 873                         batadv_hardif_put(new_if);
 874         }
 875
 876         bat_priv->algo_ops->iface.disable(hard_iface);
 877         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 878
 879         /* delete all references to this hard_iface */
 880         batadv_purge_orig_ref(bat_priv);
 881         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 882         dev_put(hard_iface->soft_iface);
 883
 884         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 885         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 886
 887         /* nobody uses this interface anymore */
 888         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 889                 batadv_gw_check_client_stop(bat_priv);
 890
 891                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 892                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 893         }
 894
 895         hard_iface->soft_iface = NULL;
 896         batadv_hardif_put(hard_iface);
 897
 898 out:
 899         if (primary_if)
 900                 batadv_hardif_put(primary_if);
 901 }
 902
 903 static struct batadv_hard_iface *
 904 batadv_hardif_add_interface(struct net_device *net_dev)
 905 {
 906         struct batadv_hard_iface *hard_iface;
 907         int ret;
 908
 909         ASSERT_RTNL();
 910
 911         if (!batadv_is_valid_iface(net_dev))
 912                 goto out;
 913
 914         dev_hold(net_dev);
 915
 916         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 917         if (!hard_iface)
 918                 goto release_dev;
 919
 920         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 921         if (ret)
 922                 goto free_if;
 923
 924         hard_iface->net_dev = net_dev;
 925         hard_iface->soft_iface = NULL;
 926         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 927
 928         batadv_debugfs_add_hardif(hard_iface);
 929
 930         INIT_LIST_HEAD(&hard_iface->list);
 931         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 932
 933         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 934         spin_lock_init(&hard_iface->neigh_list_lock);
 935         kref_init(&hard_iface->refcount);
 936
 937         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 938         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 939         if (batadv_is_wifi_hardif(hard_iface))
 940                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 941
 942         atomic_set(&hard_iface->hop_penalty, 0);
 943
 944         batadv_v_hardif_init(hard_iface);
 945
 946         batadv_check_known_mac_addr(hard_iface->net_dev);
 947         kref_get(&hard_iface->refcount);
 948         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 949         batadv_hardif_generation++;
 950
 951         return hard_iface;
 952
 953 free_if:
 954         kfree(hard_iface);
 955 release_dev:
 956         dev_put(net_dev);
 957 out:
 958         return NULL;
 959 }
 960
 961 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 962 {
 963         ASSERT_RTNL();
 964
 965         /* first deactivate interface */
 966         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 967                 batadv_hardif_disable_interface(hard_iface,
 968                                                 BATADV_IF_CLEANUP_KEEP);
 969
 970         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 971                 return;
 972
 973         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 974         batadv_debugfs_del_hardif(hard_iface);
 975         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 976         batadv_hardif_put(hard_iface);
 977 }
 978
 979 /**
 980  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 981  * @event: NETDEV_* event to handle
 982  * @net_dev: net_device which generated an event
 983  *
 984  * Return: NOTIFY_* result
 985  */
 986 static int batadv_hard_if_event_softif(unsigned long event,
 987                                        struct net_device *net_dev)
 988 {
 989         struct batadv_priv *bat_priv;
 990
 991         switch (event) {
 992         case NETDEV_REGISTER:
 993                 batadv_sysfs_add_meshif(net_dev);
 994                 bat_priv = netdev_priv(net_dev);
 995                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 996                 break;
 997         case NETDEV_CHANGENAME:
 998                 batadv_debugfs_rename_meshif(net_dev);
 999                 break;
1000         }
1001
1002         return NOTIFY_DONE;
1003 }
1004
1005 static int batadv_hard_if_event(struct notifier_block *this,
1006                                 unsigned long event, void *ptr)
1007 {
1008         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1009         struct batadv_hard_iface *hard_iface;
1010         struct batadv_hard_iface *primary_if = NULL;
1011         struct batadv_priv *bat_priv;
1012
1013         if (batadv_softif_is_valid(net_dev))
1014                 return batadv_hard_if_event_softif(event, net_dev);
1015
1016         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1017         if (!hard_iface && (event == NETDEV_REGISTER ||
1018                             event == NETDEV_POST_TYPE_CHANGE))
1019                 hard_iface = batadv_hardif_add_interface(net_dev);
1020
1021         if (!hard_iface)
1022                 goto out;
1023
1024         switch (event) {
1025         case NETDEV_UP:
1026                 batadv_hardif_activate_interface(hard_iface);
1027                 break;
1028         case NETDEV_GOING_DOWN:
1029         case NETDEV_DOWN:
1030                 batadv_hardif_deactivate_interface(hard_iface);
1031                 break;
1032         case NETDEV_UNREGISTER:
1033         case NETDEV_PRE_TYPE_CHANGE:
1034                 list_del_rcu(&hard_iface->list);
1035                 batadv_hardif_generation++;
1036
1037                 batadv_hardif_remove_interface(hard_iface);
1038                 break;
1039         case NETDEV_CHANGEMTU:
1040                 if (hard_iface->soft_iface)
1041                         batadv_update_min_mtu(hard_iface->soft_iface);
1042                 break;
1043         case NETDEV_CHANGEADDR:
1044                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1045                         goto hardif_put;
1046
1047                 batadv_check_known_mac_addr(hard_iface->net_dev);
1048
1049                 bat_priv = netdev_priv(hard_iface->soft_iface);
1050                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1051
1052                 primary_if = batadv_primary_if_get_selected(bat_priv);
1053                 if (!primary_if)
1054                         goto hardif_put;
1055
1056                 if (hard_iface == primary_if)
1057                         batadv_primary_if_update_addr(bat_priv, NULL);
1058                 break;
1059         case NETDEV_CHANGEUPPER:
1060                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1061                 if (batadv_is_wifi_hardif(hard_iface))
1062                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1063                 break;
1064         case NETDEV_CHANGENAME:
1065                 batadv_debugfs_rename_hardif(hard_iface);
1066                 break;
1067         default:
1068                 break;
1069         }
1070
1071 hardif_put:
1072         batadv_hardif_put(hard_iface);
1073 out:
1074         if (primary_if)
1075                 batadv_hardif_put(primary_if);
1076         return NOTIFY_DONE;
1077 }
1078
1079 struct notifier_block batadv_hard_if_notifier = {
1080         .notifier_call = batadv_hard_if_event,
1081 };