net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2019  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/list.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/printk.h>
  22 #include <linux/rculist.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26 #include <net/net_namespace.h>
  27 #include <net/rtnetlink.h>
  28 #include <uapi/linux/batadv_packet.h>
  29
  30 #include "bat_v.h"
  31 #include "bridge_loop_avoidance.h"
  32 #include "debugfs.h"
  33 #include "distributed-arp-table.h"
  34 #include "gateway_client.h"
  35 #include "log.h"
  36 #include "originator.h"
  37 #include "send.h"
  38 #include "soft-interface.h"
  39 #include "sysfs.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 to be used to create a new mesh
 140  * network (this behaviour would lead to a batman-over-batman configuration).
 141  * This function recursively checks all the fathers of the device passed as
 142  * 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         bool ret;
 153
 154         /* check if this is a batman-adv mesh interface */
 155         if (batadv_softif_is_valid(net_dev))
 156                 return true;
 157
 158         /* no more parents..stop recursion */
 159         if (dev_get_iflink(net_dev) == 0 ||
 160             dev_get_iflink(net_dev) == net_dev->ifindex)
 161                 return false;
 162
 163         parent_net = batadv_getlink_net(net_dev, net);
 164
 165         /* recurse over the parent device */
 166         parent_dev = __dev_get_by_index((struct net *)parent_net,
 167                                         dev_get_iflink(net_dev));
 168         /* if we got a NULL parent_dev there is something broken.. */
 169         if (!parent_dev) {
 170                 pr_err("Cannot find parent device\n");
 171                 return false;
 172         }
 173
 174         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 175                 return false;
 176
 177         ret = batadv_is_on_batman_iface(parent_dev);
 178
 179         return ret;
 180 }
 181
 182 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 183 {
 184         if (net_dev->flags & IFF_LOOPBACK)
 185                 return false;
 186
 187         if (net_dev->type != ARPHRD_ETHER)
 188                 return false;
 189
 190         if (net_dev->addr_len != ETH_ALEN)
 191                 return false;
 192
 193         /* no batman over batman */
 194         if (batadv_is_on_batman_iface(net_dev))
 195                 return false;
 196
 197         return true;
 198 }
 199
 200 /**
 201  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 202  *  interface on top of another 'real' interface
 203  * @netdev: the device to check
 204  *
 205  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 206  * instead of this.
 207  *
 208  * Return: the 'real' net device or the original net device and NULL in case
 209  *  of an error.
 210  */
 211 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 212 {
 213         struct batadv_hard_iface *hard_iface = NULL;
 214         struct net_device *real_netdev = NULL;
 215         struct net *real_net;
 216         struct net *net;
 217         int ifindex;
 218
 219         ASSERT_RTNL();
 220
 221         if (!netdev)
 222                 return NULL;
 223
 224         if (netdev->ifindex == dev_get_iflink(netdev)) {
 225                 dev_hold(netdev);
 226                 return netdev;
 227         }
 228
 229         hard_iface = batadv_hardif_get_by_netdev(netdev);
 230         if (!hard_iface || !hard_iface->soft_iface)
 231                 goto out;
 232
 233         net = dev_net(hard_iface->soft_iface);
 234         ifindex = dev_get_iflink(netdev);
 235         real_net = batadv_getlink_net(netdev, net);
 236         real_netdev = dev_get_by_index(real_net, ifindex);
 237
 238 out:
 239         if (hard_iface)
 240                 batadv_hardif_put(hard_iface);
 241         return real_netdev;
 242 }
 243
 244 /**
 245  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 246  *  interface on top of another 'real' interface
 247  * @net_device: the device to check
 248  *
 249  * Return: the 'real' net device or the original net device and NULL in case
 250  *  of an error.
 251  */
 252 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 253 {
 254         struct net_device *real_netdev;
 255
 256         rtnl_lock();
 257         real_netdev = batadv_get_real_netdevice(net_device);
 258         rtnl_unlock();
 259
 260         return real_netdev;
 261 }
 262
 263 /**
 264  * batadv_is_wext_netdev() - check if the given net_device struct is a
 265  *  wext wifi interface
 266  * @net_device: the device to check
 267  *
 268  * Return: true if the net device is a wext wireless device, false
 269  *  otherwise.
 270  */
 271 static bool batadv_is_wext_netdev(struct net_device *net_device)
 272 {
 273         if (!net_device)
 274                 return false;
 275
 276 #ifdef CONFIG_WIRELESS_EXT
 277         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 278          * check for wireless_handlers != NULL
 279          */
 280         if (net_device->wireless_handlers)
 281                 return true;
 282 #endif
 283
 284         return false;
 285 }
 286
 287 /**
 288  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 289  *  cfg80211 wifi interface
 290  * @net_device: the device to check
 291  *
 292  * Return: true if the net device is a cfg80211 wireless device, false
 293  *  otherwise.
 294  */
 295 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 296 {
 297         if (!net_device)
 298                 return false;
 299
 300         /* cfg80211 drivers have to set ieee80211_ptr */
 301         if (net_device->ieee80211_ptr)
 302                 return true;
 303
 304         return false;
 305 }
 306
 307 /**
 308  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 309  * @net_device: the device to check
 310  *
 311  * Return: batadv_hard_iface_wifi_flags flags of the device
 312  */
 313 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 314 {
 315         u32 wifi_flags = 0;
 316         struct net_device *real_netdev;
 317
 318         if (batadv_is_wext_netdev(net_device))
 319                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 320
 321         if (batadv_is_cfg80211_netdev(net_device))
 322                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 323
 324         real_netdev = batadv_get_real_netdevice(net_device);
 325         if (!real_netdev)
 326                 return wifi_flags;
 327
 328         if (real_netdev == net_device)
 329                 goto out;
 330
 331         if (batadv_is_wext_netdev(real_netdev))
 332                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 333
 334         if (batadv_is_cfg80211_netdev(real_netdev))
 335                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 336
 337 out:
 338         dev_put(real_netdev);
 339         return wifi_flags;
 340 }
 341
 342 /**
 343  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 344  *  interface
 345  * @hard_iface: the device to check
 346  *
 347  * Return: true if the net device is a cfg80211 wireless device, false
 348  *  otherwise.
 349  */
 350 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 351 {
 352         u32 allowed_flags = 0;
 353
 354         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 355         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 356
 357         return !!(hard_iface->wifi_flags & allowed_flags);
 358 }
 359
 360 /**
 361  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 362  * @hard_iface: the device to check
 363  *
 364  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 365  */
 366 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 367 {
 368         if (!hard_iface)
 369                 return false;
 370
 371         return hard_iface->wifi_flags != 0;
 372 }
 373
 374 /**
 375  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 376  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 377  * @orig_addr: the originator of this packet
 378  * @orig_neigh: originator address of the forwarder we just got the packet from
 379  *  (NULL if we originated)
 380  *
 381  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 382  *
 383  * Return:
 384  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 385  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 386  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 387  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 388  */
 389 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 390                                u8 *orig_addr, u8 *orig_neigh)
 391 {
 392         struct batadv_hardif_neigh_node *hardif_neigh;
 393         struct hlist_node *first;
 394         int ret = BATADV_HARDIF_BCAST_OK;
 395
 396         rcu_read_lock();
 397
 398         /* 0 neighbors -> no (re)broadcast */
 399         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 400         if (!first) {
 401                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 402                 goto out;
 403         }
 404
 405         /* >1 neighbors -> (re)brodcast */
 406         if (rcu_dereference(hlist_next_rcu(first)))
 407                 goto out;
 408
 409         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 410                                    list);
 411
 412         /* 1 neighbor, is the originator -> no rebroadcast */
 413         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 414                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 415         /* 1 neighbor, is the one we received from -> no rebroadcast */
 416         } else if (orig_neigh &&
 417                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 418                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 419         }
 420
 421 out:
 422         rcu_read_unlock();
 423         return ret;
 424 }
 425
 426 static struct batadv_hard_iface *
 427 batadv_hardif_get_active(const struct net_device *soft_iface)
 428 {
 429         struct batadv_hard_iface *hard_iface;
 430
 431         rcu_read_lock();
 432         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 433                 if (hard_iface->soft_iface != soft_iface)
 434                         continue;
 435
 436                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 437                     kref_get_unless_zero(&hard_iface->refcount))
 438                         goto out;
 439         }
 440
 441         hard_iface = NULL;
 442
 443 out:
 444         rcu_read_unlock();
 445         return hard_iface;
 446 }
 447
 448 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 449                                           struct batadv_hard_iface *oldif)
 450 {
 451         struct batadv_hard_iface *primary_if;
 452
 453         primary_if = batadv_primary_if_get_selected(bat_priv);
 454         if (!primary_if)
 455                 goto out;
 456
 457         batadv_dat_init_own_addr(bat_priv, primary_if);
 458         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 459 out:
 460         if (primary_if)
 461                 batadv_hardif_put(primary_if);
 462 }
 463
 464 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 465                                      struct batadv_hard_iface *new_hard_iface)
 466 {
 467         struct batadv_hard_iface *curr_hard_iface;
 468
 469         ASSERT_RTNL();
 470
 471         if (new_hard_iface)
 472                 kref_get(&new_hard_iface->refcount);
 473
 474         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 475         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 476
 477         if (!new_hard_iface)
 478                 goto out;
 479
 480         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 481         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 482
 483 out:
 484         if (curr_hard_iface)
 485                 batadv_hardif_put(curr_hard_iface);
 486 }
 487
 488 static bool
 489 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 490 {
 491         if (hard_iface->net_dev->flags & IFF_UP)
 492                 return true;
 493
 494         return false;
 495 }
 496
 497 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 498 {
 499         const struct batadv_hard_iface *hard_iface;
 500
 501         rcu_read_lock();
 502         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 503                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 504                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 505                         continue;
 506
 507                 if (hard_iface->net_dev == net_dev)
 508                         continue;
 509
 510                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 511                                         net_dev->dev_addr))
 512                         continue;
 513
 514                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 515                         net_dev->dev_addr, hard_iface->net_dev->name);
 516                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 517         }
 518         rcu_read_unlock();
 519 }
 520
 521 /**
 522  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 523  * @soft_iface: netdev struct of the mesh interface
 524  */
 525 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 526 {
 527         const struct batadv_hard_iface *hard_iface;
 528         unsigned short lower_header_len = ETH_HLEN;
 529         unsigned short lower_headroom = 0;
 530         unsigned short lower_tailroom = 0;
 531         unsigned short needed_headroom;
 532
 533         rcu_read_lock();
 534         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 535                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 536                         continue;
 537
 538                 if (hard_iface->soft_iface != soft_iface)
 539                         continue;
 540
 541                 lower_header_len = max_t(unsigned short, lower_header_len,
 542                                          hard_iface->net_dev->hard_header_len);
 543
 544                 lower_headroom = max_t(unsigned short, lower_headroom,
 545                                        hard_iface->net_dev->needed_headroom);
 546
 547                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 548                                        hard_iface->net_dev->needed_tailroom);
 549         }
 550         rcu_read_unlock();
 551
 552         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 553         needed_headroom += batadv_max_header_len();
 554
 555         soft_iface->needed_headroom = needed_headroom;
 556         soft_iface->needed_tailroom = lower_tailroom;
 557 }
 558
 559 /**
 560  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 561  * @soft_iface: netdev struct of the soft interface
 562  *
 563  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 564  *  slave interfaces)
 565  */
 566 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 567 {
 568         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 569         const struct batadv_hard_iface *hard_iface;
 570         int min_mtu = INT_MAX;
 571
 572         rcu_read_lock();
 573         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 574                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 575                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 576                         continue;
 577
 578                 if (hard_iface->soft_iface != soft_iface)
 579                         continue;
 580
 581                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 582         }
 583         rcu_read_unlock();
 584
 585         if (atomic_read(&bat_priv->fragmentation) == 0)
 586                 goto out;
 587
 588         /* with fragmentation enabled the maximum size of internally generated
 589          * packets such as translation table exchanges or tvlv containers, etc
 590          * has to be calculated
 591          */
 592         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 593         min_mtu -= sizeof(struct batadv_frag_packet);
 594         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 595
 596 out:
 597         /* report to the other components the maximum amount of bytes that
 598          * batman-adv can send over the wire (without considering the payload
 599          * overhead). For example, this value is used by TT to compute the
 600          * maximum local table table size
 601          */
 602         atomic_set(&bat_priv->packet_size_max, min_mtu);
 603
 604         /* the real soft-interface MTU is computed by removing the payload
 605          * overhead from the maximum amount of bytes that was just computed.
 606          *
 607          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 608          */
 609         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 610 }
 611
 612 /**
 613  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 614  *  MTU appeared
 615  * @soft_iface: netdev struct of the soft interface
 616  */
 617 void batadv_update_min_mtu(struct net_device *soft_iface)
 618 {
 619         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 620
 621         /* Check if the local translate table should be cleaned up to match a
 622          * new (and smaller) MTU.
 623          */
 624         batadv_tt_local_resize_to_mtu(soft_iface);
 625 }
 626
 627 static void
 628 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 629 {
 630         struct batadv_priv *bat_priv;
 631         struct batadv_hard_iface *primary_if = NULL;
 632
 633         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 634                 goto out;
 635
 636         bat_priv = netdev_priv(hard_iface->soft_iface);
 637
 638         bat_priv->algo_ops->iface.update_mac(hard_iface);
 639         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 640
 641         /* the first active interface becomes our primary interface or
 642          * the next active interface after the old primary interface was removed
 643          */
 644         primary_if = batadv_primary_if_get_selected(bat_priv);
 645         if (!primary_if)
 646                 batadv_primary_if_select(bat_priv, hard_iface);
 647
 648         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 649                     hard_iface->net_dev->name);
 650
 651         batadv_update_min_mtu(hard_iface->soft_iface);
 652
 653         if (bat_priv->algo_ops->iface.activate)
 654                 bat_priv->algo_ops->iface.activate(hard_iface);
 655
 656 out:
 657         if (primary_if)
 658                 batadv_hardif_put(primary_if);
 659 }
 660
 661 static void
 662 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 663 {
 664         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 665             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 666                 return;
 667
 668         hard_iface->if_status = BATADV_IF_INACTIVE;
 669
 670         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 671                     hard_iface->net_dev->name);
 672
 673         batadv_update_min_mtu(hard_iface->soft_iface);
 674 }
 675
 676 /**
 677  * batadv_master_del_slave() - remove hard_iface from the current master iface
 678  * @slave: the interface enslaved in another master
 679  * @master: the master from which slave has to be removed
 680  *
 681  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 682  * is free'd and master can correctly change its internal state.
 683  *
 684  * Return: 0 on success, a negative value representing the error otherwise
 685  */
 686 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 687                                    struct net_device *master)
 688 {
 689         int ret;
 690
 691         if (!master)
 692                 return 0;
 693
 694         ret = -EBUSY;
 695         if (master->netdev_ops->ndo_del_slave)
 696                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 697
 698         return ret;
 699 }
 700
 701 /**
 702  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 703  * @hard_iface: hard interface to add to soft interface
 704  * @net: the applicable net namespace
 705  * @iface_name: name of the soft interface
 706  *
 707  * Return: 0 on success or negative error number in case of failure
 708  */
 709 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 710                                    struct net *net, const char *iface_name)
 711 {
 712         struct batadv_priv *bat_priv;
 713         struct net_device *soft_iface, *master;
 714         __be16 ethertype = htons(ETH_P_BATMAN);
 715         int max_header_len = batadv_max_header_len();
 716         int ret;
 717
 718         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 719                 goto out;
 720
 721         kref_get(&hard_iface->refcount);
 722
 723         soft_iface = dev_get_by_name(net, iface_name);
 724
 725         if (!soft_iface) {
 726                 soft_iface = batadv_softif_create(net, iface_name);
 727
 728                 if (!soft_iface) {
 729                         ret = -ENOMEM;
 730                         goto err;
 731                 }
 732
 733                 /* dev_get_by_name() increases the reference counter for us */
 734                 dev_hold(soft_iface);
 735         }
 736
 737         if (!batadv_softif_is_valid(soft_iface)) {
 738                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 739                        soft_iface->name);
 740                 ret = -EINVAL;
 741                 goto err_dev;
 742         }
 743
 744         /* check if the interface is enslaved in another virtual one and
 745          * in that case unlink it first
 746          */
 747         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 748         ret = batadv_master_del_slave(hard_iface, master);
 749         if (ret)
 750                 goto err_dev;
 751
 752         hard_iface->soft_iface = soft_iface;
 753         bat_priv = netdev_priv(hard_iface->soft_iface);
 754
 755         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 756                                            soft_iface, NULL, NULL, NULL);
 757         if (ret)
 758                 goto err_dev;
 759
 760         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 761         if (ret < 0)
 762                 goto err_upper;
 763
 764         hard_iface->if_status = BATADV_IF_INACTIVE;
 765
 766         kref_get(&hard_iface->refcount);
 767         hard_iface->batman_adv_ptype.type = ethertype;
 768         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 769         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 770         dev_add_pack(&hard_iface->batman_adv_ptype);
 771
 772         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 773                     hard_iface->net_dev->name);
 774
 775         if (atomic_read(&bat_priv->fragmentation) &&
 776             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 777                 batadv_info(hard_iface->soft_iface,
 778                             "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",
 779                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 780                             ETH_DATA_LEN + max_header_len);
 781
 782         if (!atomic_read(&bat_priv->fragmentation) &&
 783             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 784                 batadv_info(hard_iface->soft_iface,
 785                             "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",
 786                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 787                             ETH_DATA_LEN + max_header_len);
 788
 789         if (batadv_hardif_is_iface_up(hard_iface))
 790                 batadv_hardif_activate_interface(hard_iface);
 791         else
 792                 batadv_err(hard_iface->soft_iface,
 793                            "Not using interface %s (retrying later): interface not active\n",
 794                            hard_iface->net_dev->name);
 795
 796         batadv_hardif_recalc_extra_skbroom(soft_iface);
 797
 798 out:
 799         return 0;
 800
 801 err_upper:
 802         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 803 err_dev:
 804         hard_iface->soft_iface = NULL;
 805         dev_put(soft_iface);
 806 err:
 807         batadv_hardif_put(hard_iface);
 808         return ret;
 809 }
 810
 811 /**
 812  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 813  * @soft_iface: soft interface to check
 814  *
 815  * This function is only using RCU for locking - the result can therefore be
 816  * off when another functions is modifying the list at the same time. The
 817  * caller can use the rtnl_lock to make sure that the count is accurate.
 818  *
 819  * Return: number of connected/enslaved hard interfaces
 820  */
 821 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 822 {
 823         struct batadv_hard_iface *hard_iface;
 824         size_t count = 0;
 825
 826         rcu_read_lock();
 827         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 828                 if (hard_iface->soft_iface != soft_iface)
 829                         continue;
 830
 831                 count++;
 832         }
 833         rcu_read_unlock();
 834
 835         return count;
 836 }
 837
 838 /**
 839  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 840  * @hard_iface: hard interface to be removed
 841  * @autodel: whether to delete soft interface when it doesn't contain any other
 842  *  slave interfaces
 843  */
 844 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 845                                      enum batadv_hard_if_cleanup autodel)
 846 {
 847         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 848         struct batadv_hard_iface *primary_if = NULL;
 849
 850         batadv_hardif_deactivate_interface(hard_iface);
 851
 852         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 853                 goto out;
 854
 855         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 856                     hard_iface->net_dev->name);
 857         dev_remove_pack(&hard_iface->batman_adv_ptype);
 858         batadv_hardif_put(hard_iface);
 859
 860         primary_if = batadv_primary_if_get_selected(bat_priv);
 861         if (hard_iface == primary_if) {
 862                 struct batadv_hard_iface *new_if;
 863
 864                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 865                 batadv_primary_if_select(bat_priv, new_if);
 866
 867                 if (new_if)
 868                         batadv_hardif_put(new_if);
 869         }
 870
 871         bat_priv->algo_ops->iface.disable(hard_iface);
 872         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 873
 874         /* delete all references to this hard_iface */
 875         batadv_purge_orig_ref(bat_priv);
 876         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 877         dev_put(hard_iface->soft_iface);
 878
 879         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 880         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 881
 882         /* nobody uses this interface anymore */
 883         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 884                 batadv_gw_check_client_stop(bat_priv);
 885
 886                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 887                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 888         }
 889
 890         hard_iface->soft_iface = NULL;
 891         batadv_hardif_put(hard_iface);
 892
 893 out:
 894         if (primary_if)
 895                 batadv_hardif_put(primary_if);
 896 }
 897
 898 static struct batadv_hard_iface *
 899 batadv_hardif_add_interface(struct net_device *net_dev)
 900 {
 901         struct batadv_hard_iface *hard_iface;
 902         int ret;
 903
 904         ASSERT_RTNL();
 905
 906         if (!batadv_is_valid_iface(net_dev))
 907                 goto out;
 908
 909         dev_hold(net_dev);
 910
 911         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 912         if (!hard_iface)
 913                 goto release_dev;
 914
 915         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 916         if (ret)
 917                 goto free_if;
 918
 919         hard_iface->net_dev = net_dev;
 920         hard_iface->soft_iface = NULL;
 921         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 922
 923         ret = batadv_debugfs_add_hardif(hard_iface);
 924         if (ret)
 925                 goto free_sysfs;
 926
 927         INIT_LIST_HEAD(&hard_iface->list);
 928         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 929
 930         spin_lock_init(&hard_iface->neigh_list_lock);
 931         kref_init(&hard_iface->refcount);
 932
 933         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 934         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 935         if (batadv_is_wifi_hardif(hard_iface))
 936                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 937
 938         batadv_v_hardif_init(hard_iface);
 939
 940         batadv_check_known_mac_addr(hard_iface->net_dev);
 941         kref_get(&hard_iface->refcount);
 942         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 943         batadv_hardif_generation++;
 944
 945         return hard_iface;
 946
 947 free_sysfs:
 948         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 949 free_if:
 950         kfree(hard_iface);
 951 release_dev:
 952         dev_put(net_dev);
 953 out:
 954         return NULL;
 955 }
 956
 957 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 958 {
 959         ASSERT_RTNL();
 960
 961         /* first deactivate interface */
 962         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 963                 batadv_hardif_disable_interface(hard_iface,
 964                                                 BATADV_IF_CLEANUP_KEEP);
 965
 966         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 967                 return;
 968
 969         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 970         batadv_debugfs_del_hardif(hard_iface);
 971         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 972         batadv_hardif_put(hard_iface);
 973 }
 974
 975 /**
 976  * batadv_hardif_remove_interfaces() - Remove all hard interfaces
 977  */
 978 void batadv_hardif_remove_interfaces(void)
 979 {
 980         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 981
 982         rtnl_lock();
 983         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 984                                  &batadv_hardif_list, list) {
 985                 list_del_rcu(&hard_iface->list);
 986                 batadv_hardif_generation++;
 987                 batadv_hardif_remove_interface(hard_iface);
 988         }
 989         rtnl_unlock();
 990 }
 991
 992 /**
 993  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 994  * @event: NETDEV_* event to handle
 995  * @net_dev: net_device which generated an event
 996  *
 997  * Return: NOTIFY_* result
 998  */
 999 static int batadv_hard_if_event_softif(unsigned long event,
1000                                        struct net_device *net_dev)
1001 {
1002         struct batadv_priv *bat_priv;
1003
1004         switch (event) {
1005         case NETDEV_REGISTER:
1006                 batadv_sysfs_add_meshif(net_dev);
1007                 bat_priv = netdev_priv(net_dev);
1008                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1009                 break;
1010         case NETDEV_CHANGENAME:
1011                 batadv_debugfs_rename_meshif(net_dev);
1012                 break;
1013         }
1014
1015         return NOTIFY_DONE;
1016 }
1017
1018 static int batadv_hard_if_event(struct notifier_block *this,
1019                                 unsigned long event, void *ptr)
1020 {
1021         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1022         struct batadv_hard_iface *hard_iface;
1023         struct batadv_hard_iface *primary_if = NULL;
1024         struct batadv_priv *bat_priv;
1025
1026         if (batadv_softif_is_valid(net_dev))
1027                 return batadv_hard_if_event_softif(event, net_dev);
1028
1029         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1030         if (!hard_iface && (event == NETDEV_REGISTER ||
1031                             event == NETDEV_POST_TYPE_CHANGE))
1032                 hard_iface = batadv_hardif_add_interface(net_dev);
1033
1034         if (!hard_iface)
1035                 goto out;
1036
1037         switch (event) {
1038         case NETDEV_UP:
1039                 batadv_hardif_activate_interface(hard_iface);
1040                 break;
1041         case NETDEV_GOING_DOWN:
1042         case NETDEV_DOWN:
1043                 batadv_hardif_deactivate_interface(hard_iface);
1044                 break;
1045         case NETDEV_UNREGISTER:
1046         case NETDEV_PRE_TYPE_CHANGE:
1047                 list_del_rcu(&hard_iface->list);
1048                 batadv_hardif_generation++;
1049
1050                 batadv_hardif_remove_interface(hard_iface);
1051                 break;
1052         case NETDEV_CHANGEMTU:
1053                 if (hard_iface->soft_iface)
1054                         batadv_update_min_mtu(hard_iface->soft_iface);
1055                 break;
1056         case NETDEV_CHANGEADDR:
1057                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1058                         goto hardif_put;
1059
1060                 batadv_check_known_mac_addr(hard_iface->net_dev);
1061
1062                 bat_priv = netdev_priv(hard_iface->soft_iface);
1063                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1064
1065                 primary_if = batadv_primary_if_get_selected(bat_priv);
1066                 if (!primary_if)
1067                         goto hardif_put;
1068
1069                 if (hard_iface == primary_if)
1070                         batadv_primary_if_update_addr(bat_priv, NULL);
1071                 break;
1072         case NETDEV_CHANGEUPPER:
1073                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1074                 if (batadv_is_wifi_hardif(hard_iface))
1075                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1076                 break;
1077         case NETDEV_CHANGENAME:
1078                 batadv_debugfs_rename_hardif(hard_iface);
1079                 break;
1080         default:
1081                 break;
1082         }
1083
1084 hardif_put:
1085         batadv_hardif_put(hard_iface);
1086 out:
1087         if (primary_if)
1088                 batadv_hardif_put(primary_if);
1089         return NOTIFY_DONE;
1090 }
1091
1092 struct notifier_block batadv_hard_if_notifier = {
1093         .notifier_call = batadv_hard_if_event,
1094 };