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         /* fragmentation headers don't strip the unicast/... header */
 558         needed_headroom += sizeof(struct batadv_frag_packet);
 559
 560         soft_iface->needed_headroom = needed_headroom;
 561         soft_iface->needed_tailroom = lower_tailroom;
 562 }
 563
 564 /**
 565  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 566  * @soft_iface: netdev struct of the soft interface
 567  *
 568  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 569  *  slave interfaces)
 570  */
 571 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 572 {
 573         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 574         const struct batadv_hard_iface *hard_iface;
 575         int min_mtu = INT_MAX;
 576
 577         rcu_read_lock();
 578         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 579                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 580                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 581                         continue;
 582
 583                 if (hard_iface->soft_iface != soft_iface)
 584                         continue;
 585
 586                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 587         }
 588         rcu_read_unlock();
 589
 590         if (atomic_read(&bat_priv->fragmentation) == 0)
 591                 goto out;
 592
 593         /* with fragmentation enabled the maximum size of internally generated
 594          * packets such as translation table exchanges or tvlv containers, etc
 595          * has to be calculated
 596          */
 597         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 598         min_mtu -= sizeof(struct batadv_frag_packet);
 599         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 600
 601 out:
 602         /* report to the other components the maximum amount of bytes that
 603          * batman-adv can send over the wire (without considering the payload
 604          * overhead). For example, this value is used by TT to compute the
 605          * maximum local table size
 606          */
 607         atomic_set(&bat_priv->packet_size_max, min_mtu);
 608
 609         /* the real soft-interface MTU is computed by removing the payload
 610          * overhead from the maximum amount of bytes that was just computed.
 611          *
 612          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 613          */
 614         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 615 }
 616
 617 /**
 618  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 619  *  MTU appeared
 620  * @soft_iface: netdev struct of the soft interface
 621  */
 622 void batadv_update_min_mtu(struct net_device *soft_iface)
 623 {
 624         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 625
 626         /* Check if the local translate table should be cleaned up to match a
 627          * new (and smaller) MTU.
 628          */
 629         batadv_tt_local_resize_to_mtu(soft_iface);
 630 }
 631
 632 static void
 633 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 634 {
 635         struct batadv_priv *bat_priv;
 636         struct batadv_hard_iface *primary_if = NULL;
 637
 638         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 639                 goto out;
 640
 641         bat_priv = netdev_priv(hard_iface->soft_iface);
 642
 643         bat_priv->algo_ops->iface.update_mac(hard_iface);
 644         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 645
 646         /* the first active interface becomes our primary interface or
 647          * the next active interface after the old primary interface was removed
 648          */
 649         primary_if = batadv_primary_if_get_selected(bat_priv);
 650         if (!primary_if)
 651                 batadv_primary_if_select(bat_priv, hard_iface);
 652
 653         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 654                     hard_iface->net_dev->name);
 655
 656         batadv_update_min_mtu(hard_iface->soft_iface);
 657
 658         if (bat_priv->algo_ops->iface.activate)
 659                 bat_priv->algo_ops->iface.activate(hard_iface);
 660
 661 out:
 662         if (primary_if)
 663                 batadv_hardif_put(primary_if);
 664 }
 665
 666 static void
 667 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 668 {
 669         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 670             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 671                 return;
 672
 673         hard_iface->if_status = BATADV_IF_INACTIVE;
 674
 675         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 676                     hard_iface->net_dev->name);
 677
 678         batadv_update_min_mtu(hard_iface->soft_iface);
 679 }
 680
 681 /**
 682  * batadv_master_del_slave() - remove hard_iface from the current master iface
 683  * @slave: the interface enslaved in another master
 684  * @master: the master from which slave has to be removed
 685  *
 686  * Invoke ndo_del_slave on master passing slave as argument. In this way the
 687  * slave is free'd and the master can correctly change its internal state.
 688  *
 689  * Return: 0 on success, a negative value representing the error otherwise
 690  */
 691 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 692                                    struct net_device *master)
 693 {
 694         int ret;
 695
 696         if (!master)
 697                 return 0;
 698
 699         ret = -EBUSY;
 700         if (master->netdev_ops->ndo_del_slave)
 701                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 702
 703         return ret;
 704 }
 705
 706 /**
 707  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 708  * @hard_iface: hard interface to add to soft interface
 709  * @net: the applicable net namespace
 710  * @iface_name: name of the soft interface
 711  *
 712  * Return: 0 on success or negative error number in case of failure
 713  */
 714 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 715                                    struct net *net, const char *iface_name)
 716 {
 717         struct batadv_priv *bat_priv;
 718         struct net_device *soft_iface, *master;
 719         __be16 ethertype = htons(ETH_P_BATMAN);
 720         int max_header_len = batadv_max_header_len();
 721         int ret;
 722
 723         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 724                 goto out;
 725
 726         kref_get(&hard_iface->refcount);
 727
 728         soft_iface = dev_get_by_name(net, iface_name);
 729
 730         if (!soft_iface) {
 731                 soft_iface = batadv_softif_create(net, iface_name);
 732
 733                 if (!soft_iface) {
 734                         ret = -ENOMEM;
 735                         goto err;
 736                 }
 737
 738                 /* dev_get_by_name() increases the reference counter for us */
 739                 dev_hold(soft_iface);
 740         }
 741
 742         if (!batadv_softif_is_valid(soft_iface)) {
 743                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 744                        soft_iface->name);
 745                 ret = -EINVAL;
 746                 goto err_dev;
 747         }
 748
 749         /* check if the interface is enslaved in another virtual one and
 750          * in that case unlink it first
 751          */
 752         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 753         ret = batadv_master_del_slave(hard_iface, master);
 754         if (ret)
 755                 goto err_dev;
 756
 757         hard_iface->soft_iface = soft_iface;
 758         bat_priv = netdev_priv(hard_iface->soft_iface);
 759
 760         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 761                                            soft_iface, NULL, NULL, NULL);
 762         if (ret)
 763                 goto err_dev;
 764
 765         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 766         if (ret < 0)
 767                 goto err_upper;
 768
 769         hard_iface->if_status = BATADV_IF_INACTIVE;
 770
 771         kref_get(&hard_iface->refcount);
 772         hard_iface->batman_adv_ptype.type = ethertype;
 773         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 774         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 775         dev_add_pack(&hard_iface->batman_adv_ptype);
 776
 777         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 778                     hard_iface->net_dev->name);
 779
 780         if (atomic_read(&bat_priv->fragmentation) &&
 781             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 782                 batadv_info(hard_iface->soft_iface,
 783                             "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",
 784                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 785                             ETH_DATA_LEN + max_header_len);
 786
 787         if (!atomic_read(&bat_priv->fragmentation) &&
 788             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 789                 batadv_info(hard_iface->soft_iface,
 790                             "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",
 791                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 792                             ETH_DATA_LEN + max_header_len);
 793
 794         if (batadv_hardif_is_iface_up(hard_iface))
 795                 batadv_hardif_activate_interface(hard_iface);
 796         else
 797                 batadv_err(hard_iface->soft_iface,
 798                            "Not using interface %s (retrying later): interface not active\n",
 799                            hard_iface->net_dev->name);
 800
 801         batadv_hardif_recalc_extra_skbroom(soft_iface);
 802
 803         if (bat_priv->algo_ops->iface.enabled)
 804                 bat_priv->algo_ops->iface.enabled(hard_iface);
 805
 806 out:
 807         return 0;
 808
 809 err_upper:
 810         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 811 err_dev:
 812         hard_iface->soft_iface = NULL;
 813         dev_put(soft_iface);
 814 err:
 815         batadv_hardif_put(hard_iface);
 816         return ret;
 817 }
 818
 819 /**
 820  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 821  * @soft_iface: soft interface to check
 822  *
 823  * This function is only using RCU for locking - the result can therefore be
 824  * off when another function is modifying the list at the same time. The
 825  * caller can use the rtnl_lock to make sure that the count is accurate.
 826  *
 827  * Return: number of connected/enslaved hard interfaces
 828  */
 829 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 830 {
 831         struct batadv_hard_iface *hard_iface;
 832         size_t count = 0;
 833
 834         rcu_read_lock();
 835         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 836                 if (hard_iface->soft_iface != soft_iface)
 837                         continue;
 838
 839                 count++;
 840         }
 841         rcu_read_unlock();
 842
 843         return count;
 844 }
 845
 846 /**
 847  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 848  * @hard_iface: hard interface to be removed
 849  * @autodel: whether to delete soft interface when it doesn't contain any other
 850  *  slave interfaces
 851  */
 852 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 853                                      enum batadv_hard_if_cleanup autodel)
 854 {
 855         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 856         struct batadv_hard_iface *primary_if = NULL;
 857
 858         batadv_hardif_deactivate_interface(hard_iface);
 859
 860         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 861                 goto out;
 862
 863         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 864                     hard_iface->net_dev->name);
 865         dev_remove_pack(&hard_iface->batman_adv_ptype);
 866         batadv_hardif_put(hard_iface);
 867
 868         primary_if = batadv_primary_if_get_selected(bat_priv);
 869         if (hard_iface == primary_if) {
 870                 struct batadv_hard_iface *new_if;
 871
 872                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 873                 batadv_primary_if_select(bat_priv, new_if);
 874
 875                 if (new_if)
 876                         batadv_hardif_put(new_if);
 877         }
 878
 879         bat_priv->algo_ops->iface.disable(hard_iface);
 880         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 881
 882         /* delete all references to this hard_iface */
 883         batadv_purge_orig_ref(bat_priv);
 884         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 885         dev_put(hard_iface->soft_iface);
 886
 887         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 888         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 889
 890         /* nobody uses this interface anymore */
 891         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 892                 batadv_gw_check_client_stop(bat_priv);
 893
 894                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 895                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 896         }
 897
 898         hard_iface->soft_iface = NULL;
 899         batadv_hardif_put(hard_iface);
 900
 901 out:
 902         if (primary_if)
 903                 batadv_hardif_put(primary_if);
 904 }
 905
 906 static struct batadv_hard_iface *
 907 batadv_hardif_add_interface(struct net_device *net_dev)
 908 {
 909         struct batadv_hard_iface *hard_iface;
 910         int ret;
 911
 912         ASSERT_RTNL();
 913
 914         if (!batadv_is_valid_iface(net_dev))
 915                 goto out;
 916
 917         dev_hold(net_dev);
 918
 919         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 920         if (!hard_iface)
 921                 goto release_dev;
 922
 923         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 924         if (ret)
 925                 goto free_if;
 926
 927         hard_iface->net_dev = net_dev;
 928         hard_iface->soft_iface = NULL;
 929         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 930
 931         batadv_debugfs_add_hardif(hard_iface);
 932
 933         INIT_LIST_HEAD(&hard_iface->list);
 934         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 935
 936         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 937         spin_lock_init(&hard_iface->neigh_list_lock);
 938         kref_init(&hard_iface->refcount);
 939
 940         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 941         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 942         if (batadv_is_wifi_hardif(hard_iface))
 943                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 944
 945         atomic_set(&hard_iface->hop_penalty, 0);
 946
 947         batadv_v_hardif_init(hard_iface);
 948
 949         batadv_check_known_mac_addr(hard_iface->net_dev);
 950         kref_get(&hard_iface->refcount);
 951         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 952         batadv_hardif_generation++;
 953
 954         return hard_iface;
 955
 956 free_if:
 957         kfree(hard_iface);
 958 release_dev:
 959         dev_put(net_dev);
 960 out:
 961         return NULL;
 962 }
 963
 964 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 965 {
 966         ASSERT_RTNL();
 967
 968         /* first deactivate interface */
 969         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 970                 batadv_hardif_disable_interface(hard_iface,
 971                                                 BATADV_IF_CLEANUP_KEEP);
 972
 973         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 974                 return;
 975
 976         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 977         batadv_debugfs_del_hardif(hard_iface);
 978         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 979         batadv_hardif_put(hard_iface);
 980 }
 981
 982 /**
 983  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 984  * @event: NETDEV_* event to handle
 985  * @net_dev: net_device which generated an event
 986  *
 987  * Return: NOTIFY_* result
 988  */
 989 static int batadv_hard_if_event_softif(unsigned long event,
 990                                        struct net_device *net_dev)
 991 {
 992         struct batadv_priv *bat_priv;
 993
 994         switch (event) {
 995         case NETDEV_REGISTER:
 996                 batadv_sysfs_add_meshif(net_dev);
 997                 bat_priv = netdev_priv(net_dev);
 998                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 999                 break;
1000         case NETDEV_CHANGENAME:
1001                 batadv_debugfs_rename_meshif(net_dev);
1002                 break;
1003         }
1004
1005         return NOTIFY_DONE;
1006 }
1007
1008 static int batadv_hard_if_event(struct notifier_block *this,
1009                                 unsigned long event, void *ptr)
1010 {
1011         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1012         struct batadv_hard_iface *hard_iface;
1013         struct batadv_hard_iface *primary_if = NULL;
1014         struct batadv_priv *bat_priv;
1015
1016         if (batadv_softif_is_valid(net_dev))
1017                 return batadv_hard_if_event_softif(event, net_dev);
1018
1019         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1020         if (!hard_iface && (event == NETDEV_REGISTER ||
1021                             event == NETDEV_POST_TYPE_CHANGE))
1022                 hard_iface = batadv_hardif_add_interface(net_dev);
1023
1024         if (!hard_iface)
1025                 goto out;
1026
1027         switch (event) {
1028         case NETDEV_UP:
1029                 batadv_hardif_activate_interface(hard_iface);
1030                 break;
1031         case NETDEV_GOING_DOWN:
1032         case NETDEV_DOWN:
1033                 batadv_hardif_deactivate_interface(hard_iface);
1034                 break;
1035         case NETDEV_UNREGISTER:
1036         case NETDEV_PRE_TYPE_CHANGE:
1037                 list_del_rcu(&hard_iface->list);
1038                 batadv_hardif_generation++;
1039
1040                 batadv_hardif_remove_interface(hard_iface);
1041                 break;
1042         case NETDEV_CHANGEMTU:
1043                 if (hard_iface->soft_iface)
1044                         batadv_update_min_mtu(hard_iface->soft_iface);
1045                 break;
1046         case NETDEV_CHANGEADDR:
1047                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1048                         goto hardif_put;
1049
1050                 batadv_check_known_mac_addr(hard_iface->net_dev);
1051
1052                 bat_priv = netdev_priv(hard_iface->soft_iface);
1053                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1054
1055                 primary_if = batadv_primary_if_get_selected(bat_priv);
1056                 if (!primary_if)
1057                         goto hardif_put;
1058
1059                 if (hard_iface == primary_if)
1060                         batadv_primary_if_update_addr(bat_priv, NULL);
1061                 break;
1062         case NETDEV_CHANGEUPPER:
1063                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1064                 if (batadv_is_wifi_hardif(hard_iface))
1065                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1066                 break;
1067         case NETDEV_CHANGENAME:
1068                 batadv_debugfs_rename_hardif(hard_iface);
1069                 break;
1070         default:
1071                 break;
1072         }
1073
1074 hardif_put:
1075         batadv_hardif_put(hard_iface);
1076 out:
1077         if (primary_if)
1078                 batadv_hardif_put(primary_if);
1079         return NOTIFY_DONE;
1080 }
1081
1082 struct notifier_block batadv_hard_if_notifier = {
1083         .notifier_call = batadv_hard_if_event,
1084 };