net/batman-adv/hard-interface.c

   1 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "hard-interface.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/bug.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/fs.h>
  26 #include <linux/if.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kref.h>
  31 #include <linux/list.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/printk.h>
  34 #include <linux/rculist.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <net/net_namespace.h>
  39 #include <net/rtnetlink.h>
  40
  41 #include "bat_v.h"
  42 #include "bridge_loop_avoidance.h"
  43 #include "debugfs.h"
  44 #include "distributed-arp-table.h"
  45 #include "gateway_client.h"
  46 #include "log.h"
  47 #include "originator.h"
  48 #include "packet.h"
  49 #include "send.h"
  50 #include "soft-interface.h"
  51 #include "sysfs.h"
  52 #include "translation-table.h"
  53
  54 /**
  55  * batadv_hardif_release - release hard interface from lists and queue for
  56  *  free after rcu grace period
  57  * @ref: kref pointer of the hard interface
  58  */
  59 void batadv_hardif_release(struct kref *ref)
  60 {
  61         struct batadv_hard_iface *hard_iface;
  62
  63         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  64         dev_put(hard_iface->net_dev);
  65
  66         kfree_rcu(hard_iface, rcu);
  67 }
  68
  69 struct batadv_hard_iface *
  70 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  71 {
  72         struct batadv_hard_iface *hard_iface;
  73
  74         rcu_read_lock();
  75         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  76                 if (hard_iface->net_dev == net_dev &&
  77                     kref_get_unless_zero(&hard_iface->refcount))
  78                         goto out;
  79         }
  80
  81         hard_iface = NULL;
  82
  83 out:
  84         rcu_read_unlock();
  85         return hard_iface;
  86 }
  87
  88 /**
  89  * batadv_getlink_net - return link net namespace (of use fallback)
  90  * @netdev: net_device to check
  91  * @fallback_net: return in case get_link_net is not available for @netdev
  92  *
  93  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  94  */
  95 static struct net *batadv_getlink_net(const struct net_device *netdev,
  96                                       struct net *fallback_net)
  97 {
  98         if (!netdev->rtnl_link_ops)
  99                 return fallback_net;
 100
 101         if (!netdev->rtnl_link_ops->get_link_net)
 102                 return fallback_net;
 103
 104         return netdev->rtnl_link_ops->get_link_net(netdev);
 105 }
 106
 107 /**
 108  * batadv_mutual_parents - check if two devices are each others parent
 109  * @dev1: 1st net dev
 110  * @net1: 1st devices netns
 111  * @dev2: 2nd net dev
 112  * @net2: 2nd devices netns
 113  *
 114  * veth devices come in pairs and each is the parent of the other!
 115  *
 116  * Return: true if the devices are each others parent, otherwise false
 117  */
 118 static bool batadv_mutual_parents(const struct net_device *dev1,
 119                                   struct net *net1,
 120                                   const struct net_device *dev2,
 121                                   struct net *net2)
 122 {
 123         int dev1_parent_iflink = dev_get_iflink(dev1);
 124         int dev2_parent_iflink = dev_get_iflink(dev2);
 125         const struct net *dev1_parent_net;
 126         const struct net *dev2_parent_net;
 127
 128         dev1_parent_net = batadv_getlink_net(dev1, net1);
 129         dev2_parent_net = batadv_getlink_net(dev2, net2);
 130
 131         if (!dev1_parent_iflink || !dev2_parent_iflink)
 132                 return false;
 133
 134         return (dev1_parent_iflink == dev2->ifindex) &&
 135                (dev2_parent_iflink == dev1->ifindex) &&
 136                net_eq(dev1_parent_net, net2) &&
 137                net_eq(dev2_parent_net, net1);
 138 }
 139
 140 /**
 141  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
 142  * @net_dev: the device to check
 143  *
 144  * If the user creates any virtual device on top of a batman-adv interface, it
 145  * is important to prevent this new interface to be used to create a new mesh
 146  * network (this behaviour would lead to a batman-over-batman configuration).
 147  * This function recursively checks all the fathers of the device passed as
 148  * argument looking for a batman-adv soft interface.
 149  *
 150  * Return: true if the device is descendant of a batman-adv mesh interface (or
 151  * if it is a batman-adv interface itself), false otherwise
 152  */
 153 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 154 {
 155         struct net *net = dev_net(net_dev);
 156         struct net_device *parent_dev;
 157         struct net *parent_net;
 158         bool ret;
 159
 160         /* check if this is a batman-adv mesh interface */
 161         if (batadv_softif_is_valid(net_dev))
 162                 return true;
 163
 164         /* no more parents..stop recursion */
 165         if (dev_get_iflink(net_dev) == 0 ||
 166             dev_get_iflink(net_dev) == net_dev->ifindex)
 167                 return false;
 168
 169         parent_net = batadv_getlink_net(net_dev, net);
 170
 171         /* recurse over the parent device */
 172         parent_dev = __dev_get_by_index((struct net *)parent_net,
 173                                         dev_get_iflink(net_dev));
 174         /* if we got a NULL parent_dev there is something broken.. */
 175         if (WARN(!parent_dev, "Cannot find parent device"))
 176                 return false;
 177
 178         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 179                 return false;
 180
 181         ret = batadv_is_on_batman_iface(parent_dev);
 182
 183         return ret;
 184 }
 185
 186 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 187 {
 188         if (net_dev->flags & IFF_LOOPBACK)
 189                 return false;
 190
 191         if (net_dev->type != ARPHRD_ETHER)
 192                 return false;
 193
 194         if (net_dev->addr_len != ETH_ALEN)
 195                 return false;
 196
 197         /* no batman over batman */
 198         if (batadv_is_on_batman_iface(net_dev))
 199                 return false;
 200
 201         return true;
 202 }
 203
 204 /**
 205  * batadv_get_real_netdevice - check if the given netdev struct is a virtual
 206  *  interface on top of another 'real' interface
 207  * @netdev: the device to check
 208  *
 209  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 210  * instead of this.
 211  *
 212  * Return: the 'real' net device or the original net device and NULL in case
 213  *  of an error.
 214  */
 215 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 216 {
 217         struct batadv_hard_iface *hard_iface = NULL;
 218         struct net_device *real_netdev = NULL;
 219         struct net *real_net;
 220         struct net *net;
 221         int ifindex;
 222
 223         ASSERT_RTNL();
 224
 225         if (!netdev)
 226                 return NULL;
 227
 228         if (netdev->ifindex == dev_get_iflink(netdev)) {
 229                 dev_hold(netdev);
 230                 return netdev;
 231         }
 232
 233         hard_iface = batadv_hardif_get_by_netdev(netdev);
 234         if (!hard_iface || !hard_iface->soft_iface)
 235                 goto out;
 236
 237         net = dev_net(hard_iface->soft_iface);
 238         ifindex = dev_get_iflink(netdev);
 239         real_net = batadv_getlink_net(netdev, net);
 240         real_netdev = dev_get_by_index(real_net, ifindex);
 241
 242 out:
 243         if (hard_iface)
 244                 batadv_hardif_put(hard_iface);
 245         return real_netdev;
 246 }
 247
 248 /**
 249  * batadv_get_real_netdev - check if the given net_device struct is a virtual
 250  *  interface on top of another 'real' interface
 251  * @net_device: the device to check
 252  *
 253  * Return: the 'real' net device or the original net device and NULL in case
 254  *  of an error.
 255  */
 256 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 257 {
 258         struct net_device *real_netdev;
 259
 260         rtnl_lock();
 261         real_netdev = batadv_get_real_netdevice(net_device);
 262         rtnl_unlock();
 263
 264         return real_netdev;
 265 }
 266
 267 /**
 268  * batadv_is_wext_netdev - check if the given net_device struct is a
 269  *  wext wifi interface
 270  * @net_device: the device to check
 271  *
 272  * Return: true if the net device is a wext wireless device, false
 273  *  otherwise.
 274  */
 275 static bool batadv_is_wext_netdev(struct net_device *net_device)
 276 {
 277         if (!net_device)
 278                 return false;
 279
 280 #ifdef CONFIG_WIRELESS_EXT
 281         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 282          * check for wireless_handlers != NULL
 283          */
 284         if (net_device->wireless_handlers)
 285                 return true;
 286 #endif
 287
 288         return false;
 289 }
 290
 291 /**
 292  * batadv_is_cfg80211_netdev - check if the given net_device struct is a
 293  *  cfg80211 wifi interface
 294  * @net_device: the device to check
 295  *
 296  * Return: true if the net device is a cfg80211 wireless device, false
 297  *  otherwise.
 298  */
 299 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 300 {
 301         if (!net_device)
 302                 return false;
 303
 304         /* cfg80211 drivers have to set ieee80211_ptr */
 305         if (net_device->ieee80211_ptr)
 306                 return true;
 307
 308         return false;
 309 }
 310
 311 /**
 312  * batadv_wifi_flags_evaluate - calculate wifi flags for net_device
 313  * @net_device: the device to check
 314  *
 315  * Return: batadv_hard_iface_wifi_flags flags of the device
 316  */
 317 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 318 {
 319         u32 wifi_flags = 0;
 320         struct net_device *real_netdev;
 321
 322         if (batadv_is_wext_netdev(net_device))
 323                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 324
 325         if (batadv_is_cfg80211_netdev(net_device))
 326                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 327
 328         real_netdev = batadv_get_real_netdevice(net_device);
 329         if (!real_netdev)
 330                 return wifi_flags;
 331
 332         if (real_netdev == net_device)
 333                 goto out;
 334
 335         if (batadv_is_wext_netdev(real_netdev))
 336                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 337
 338         if (batadv_is_cfg80211_netdev(real_netdev))
 339                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 340
 341 out:
 342         dev_put(real_netdev);
 343         return wifi_flags;
 344 }
 345
 346 /**
 347  * batadv_is_cfg80211_hardif - check if the given hardif is a cfg80211 wifi
 348  *  interface
 349  * @hard_iface: the device to check
 350  *
 351  * Return: true if the net device is a cfg80211 wireless device, false
 352  *  otherwise.
 353  */
 354 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 355 {
 356         u32 allowed_flags = 0;
 357
 358         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 359         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 360
 361         return !!(hard_iface->wifi_flags & allowed_flags);
 362 }
 363
 364 /**
 365  * batadv_is_wifi_hardif - check if the given hardif is a wifi interface
 366  * @hard_iface: the device to check
 367  *
 368  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 369  */
 370 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 371 {
 372         if (!hard_iface)
 373                 return false;
 374
 375         return hard_iface->wifi_flags != 0;
 376 }
 377
 378 /**
 379  * batadv_hardif_no_broadcast - check whether (re)broadcast is necessary
 380  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 381  * @orig_addr: the originator of this packet
 382  * @orig_neigh: originator address of the forwarder we just got the packet from
 383  *  (NULL if we originated)
 384  *
 385  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 386  *
 387  * Return:
 388  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 389  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 390  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 391  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 392  */
 393 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 394                                u8 *orig_addr, u8 *orig_neigh)
 395 {
 396         struct batadv_hardif_neigh_node *hardif_neigh;
 397         struct hlist_node *first;
 398         int ret = BATADV_HARDIF_BCAST_OK;
 399
 400         rcu_read_lock();
 401
 402         /* 0 neighbors -> no (re)broadcast */
 403         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 404         if (!first) {
 405                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 406                 goto out;
 407         }
 408
 409         /* >1 neighbors -> (re)brodcast */
 410         if (rcu_dereference(hlist_next_rcu(first)))
 411                 goto out;
 412
 413         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 414                                    list);
 415
 416         /* 1 neighbor, is the originator -> no rebroadcast */
 417         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 418                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 419         /* 1 neighbor, is the one we received from -> no rebroadcast */
 420         } else if (orig_neigh &&
 421                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 422                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 423         }
 424
 425 out:
 426         rcu_read_unlock();
 427         return ret;
 428 }
 429
 430 static struct batadv_hard_iface *
 431 batadv_hardif_get_active(const struct net_device *soft_iface)
 432 {
 433         struct batadv_hard_iface *hard_iface;
 434
 435         rcu_read_lock();
 436         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 437                 if (hard_iface->soft_iface != soft_iface)
 438                         continue;
 439
 440                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 441                     kref_get_unless_zero(&hard_iface->refcount))
 442                         goto out;
 443         }
 444
 445         hard_iface = NULL;
 446
 447 out:
 448         rcu_read_unlock();
 449         return hard_iface;
 450 }
 451
 452 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 453                                           struct batadv_hard_iface *oldif)
 454 {
 455         struct batadv_hard_iface *primary_if;
 456
 457         primary_if = batadv_primary_if_get_selected(bat_priv);
 458         if (!primary_if)
 459                 goto out;
 460
 461         batadv_dat_init_own_addr(bat_priv, primary_if);
 462         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 463 out:
 464         if (primary_if)
 465                 batadv_hardif_put(primary_if);
 466 }
 467
 468 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 469                                      struct batadv_hard_iface *new_hard_iface)
 470 {
 471         struct batadv_hard_iface *curr_hard_iface;
 472
 473         ASSERT_RTNL();
 474
 475         if (new_hard_iface)
 476                 kref_get(&new_hard_iface->refcount);
 477
 478         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 479         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 480
 481         if (!new_hard_iface)
 482                 goto out;
 483
 484         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 485         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 486
 487 out:
 488         if (curr_hard_iface)
 489                 batadv_hardif_put(curr_hard_iface);
 490 }
 491
 492 static bool
 493 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 494 {
 495         if (hard_iface->net_dev->flags & IFF_UP)
 496                 return true;
 497
 498         return false;
 499 }
 500
 501 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 502 {
 503         const struct batadv_hard_iface *hard_iface;
 504
 505         rcu_read_lock();
 506         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 507                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 508                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 509                         continue;
 510
 511                 if (hard_iface->net_dev == net_dev)
 512                         continue;
 513
 514                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 515                                         net_dev->dev_addr))
 516                         continue;
 517
 518                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 519                         net_dev->dev_addr, hard_iface->net_dev->name);
 520                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 521         }
 522         rcu_read_unlock();
 523 }
 524
 525 /**
 526  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 527  * @soft_iface: netdev struct of the mesh interface
 528  */
 529 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 530 {
 531         const struct batadv_hard_iface *hard_iface;
 532         unsigned short lower_header_len = ETH_HLEN;
 533         unsigned short lower_headroom = 0;
 534         unsigned short lower_tailroom = 0;
 535         unsigned short needed_headroom;
 536
 537         rcu_read_lock();
 538         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 539                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 540                         continue;
 541
 542                 if (hard_iface->soft_iface != soft_iface)
 543                         continue;
 544
 545                 lower_header_len = max_t(unsigned short, lower_header_len,
 546                                          hard_iface->net_dev->hard_header_len);
 547
 548                 lower_headroom = max_t(unsigned short, lower_headroom,
 549                                        hard_iface->net_dev->needed_headroom);
 550
 551                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 552                                        hard_iface->net_dev->needed_tailroom);
 553         }
 554         rcu_read_unlock();
 555
 556         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 557         needed_headroom += batadv_max_header_len();
 558
 559         soft_iface->needed_headroom = needed_headroom;
 560         soft_iface->needed_tailroom = lower_tailroom;
 561 }
 562
 563 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 564 {
 565         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 566         const struct batadv_hard_iface *hard_iface;
 567         int min_mtu = INT_MAX;
 568
 569         rcu_read_lock();
 570         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 571                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 572                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 573                         continue;
 574
 575                 if (hard_iface->soft_iface != soft_iface)
 576                         continue;
 577
 578                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 579         }
 580         rcu_read_unlock();
 581
 582         if (atomic_read(&bat_priv->fragmentation) == 0)
 583                 goto out;
 584
 585         /* with fragmentation enabled the maximum size of internally generated
 586          * packets such as translation table exchanges or tvlv containers, etc
 587          * has to be calculated
 588          */
 589         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 590         min_mtu -= sizeof(struct batadv_frag_packet);
 591         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 592
 593 out:
 594         /* report to the other components the maximum amount of bytes that
 595          * batman-adv can send over the wire (without considering the payload
 596          * overhead). For example, this value is used by TT to compute the
 597          * maximum local table table size
 598          */
 599         atomic_set(&bat_priv->packet_size_max, min_mtu);
 600
 601         /* the real soft-interface MTU is computed by removing the payload
 602          * overhead from the maximum amount of bytes that was just computed.
 603          *
 604          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 605          */
 606         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 607 }
 608
 609 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 610 void batadv_update_min_mtu(struct net_device *soft_iface)
 611 {
 612         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 613
 614         /* Check if the local translate table should be cleaned up to match a
 615          * new (and smaller) MTU.
 616          */
 617         batadv_tt_local_resize_to_mtu(soft_iface);
 618 }
 619
 620 static void
 621 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 622 {
 623         struct batadv_priv *bat_priv;
 624         struct batadv_hard_iface *primary_if = NULL;
 625
 626         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 627                 goto out;
 628
 629         bat_priv = netdev_priv(hard_iface->soft_iface);
 630
 631         bat_priv->algo_ops->iface.update_mac(hard_iface);
 632         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 633
 634         /* the first active interface becomes our primary interface or
 635          * the next active interface after the old primary interface was removed
 636          */
 637         primary_if = batadv_primary_if_get_selected(bat_priv);
 638         if (!primary_if)
 639                 batadv_primary_if_select(bat_priv, hard_iface);
 640
 641         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 642                     hard_iface->net_dev->name);
 643
 644         batadv_update_min_mtu(hard_iface->soft_iface);
 645
 646         if (bat_priv->algo_ops->iface.activate)
 647                 bat_priv->algo_ops->iface.activate(hard_iface);
 648
 649 out:
 650         if (primary_if)
 651                 batadv_hardif_put(primary_if);
 652 }
 653
 654 static void
 655 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 656 {
 657         if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 658             (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 659                 return;
 660
 661         hard_iface->if_status = BATADV_IF_INACTIVE;
 662
 663         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 664                     hard_iface->net_dev->name);
 665
 666         batadv_update_min_mtu(hard_iface->soft_iface);
 667 }
 668
 669 /**
 670  * batadv_master_del_slave - remove hard_iface from the current master interface
 671  * @slave: the interface enslaved in another master
 672  * @master: the master from which slave has to be removed
 673  *
 674  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 675  * is free'd and master can correctly change its internal state.
 676  *
 677  * Return: 0 on success, a negative value representing the error otherwise
 678  */
 679 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 680                                    struct net_device *master)
 681 {
 682         int ret;
 683
 684         if (!master)
 685                 return 0;
 686
 687         ret = -EBUSY;
 688         if (master->netdev_ops->ndo_del_slave)
 689                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 690
 691         return ret;
 692 }
 693
 694 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 695                                    struct net *net, const char *iface_name)
 696 {
 697         struct batadv_priv *bat_priv;
 698         struct net_device *soft_iface, *master;
 699         __be16 ethertype = htons(ETH_P_BATMAN);
 700         int max_header_len = batadv_max_header_len();
 701         int ret;
 702
 703         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 704                 goto out;
 705
 706         kref_get(&hard_iface->refcount);
 707
 708         soft_iface = dev_get_by_name(net, iface_name);
 709
 710         if (!soft_iface) {
 711                 soft_iface = batadv_softif_create(net, iface_name);
 712
 713                 if (!soft_iface) {
 714                         ret = -ENOMEM;
 715                         goto err;
 716                 }
 717
 718                 /* dev_get_by_name() increases the reference counter for us */
 719                 dev_hold(soft_iface);
 720         }
 721
 722         if (!batadv_softif_is_valid(soft_iface)) {
 723                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 724                        soft_iface->name);
 725                 ret = -EINVAL;
 726                 goto err_dev;
 727         }
 728
 729         /* check if the interface is enslaved in another virtual one and
 730          * in that case unlink it first
 731          */
 732         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 733         ret = batadv_master_del_slave(hard_iface, master);
 734         if (ret)
 735                 goto err_dev;
 736
 737         hard_iface->soft_iface = soft_iface;
 738         bat_priv = netdev_priv(hard_iface->soft_iface);
 739
 740         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 741                                            soft_iface, NULL, NULL);
 742         if (ret)
 743                 goto err_dev;
 744
 745         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 746         if (ret < 0)
 747                 goto err_upper;
 748
 749         hard_iface->if_num = bat_priv->num_ifaces;
 750         bat_priv->num_ifaces++;
 751         hard_iface->if_status = BATADV_IF_INACTIVE;
 752         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 753         if (ret < 0) {
 754                 bat_priv->algo_ops->iface.disable(hard_iface);
 755                 bat_priv->num_ifaces--;
 756                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 757                 goto err_upper;
 758         }
 759
 760         kref_get(&hard_iface->refcount);
 761         hard_iface->batman_adv_ptype.type = ethertype;
 762         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 763         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 764         dev_add_pack(&hard_iface->batman_adv_ptype);
 765
 766         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 767                     hard_iface->net_dev->name);
 768
 769         if (atomic_read(&bat_priv->fragmentation) &&
 770             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 771                 batadv_info(hard_iface->soft_iface,
 772                             "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",
 773                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 774                             ETH_DATA_LEN + max_header_len);
 775
 776         if (!atomic_read(&bat_priv->fragmentation) &&
 777             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 778                 batadv_info(hard_iface->soft_iface,
 779                             "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",
 780                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 781                             ETH_DATA_LEN + max_header_len);
 782
 783         if (batadv_hardif_is_iface_up(hard_iface))
 784                 batadv_hardif_activate_interface(hard_iface);
 785         else
 786                 batadv_err(hard_iface->soft_iface,
 787                            "Not using interface %s (retrying later): interface not active\n",
 788                            hard_iface->net_dev->name);
 789
 790         batadv_hardif_recalc_extra_skbroom(soft_iface);
 791
 792 out:
 793         return 0;
 794
 795 err_upper:
 796         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 797 err_dev:
 798         hard_iface->soft_iface = NULL;
 799         dev_put(soft_iface);
 800 err:
 801         batadv_hardif_put(hard_iface);
 802         return ret;
 803 }
 804
 805 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 806                                      enum batadv_hard_if_cleanup autodel)
 807 {
 808         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 809         struct batadv_hard_iface *primary_if = NULL;
 810
 811         batadv_hardif_deactivate_interface(hard_iface);
 812
 813         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 814                 goto out;
 815
 816         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 817                     hard_iface->net_dev->name);
 818         dev_remove_pack(&hard_iface->batman_adv_ptype);
 819         batadv_hardif_put(hard_iface);
 820
 821         bat_priv->num_ifaces--;
 822         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 823
 824         primary_if = batadv_primary_if_get_selected(bat_priv);
 825         if (hard_iface == primary_if) {
 826                 struct batadv_hard_iface *new_if;
 827
 828                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 829                 batadv_primary_if_select(bat_priv, new_if);
 830
 831                 if (new_if)
 832                         batadv_hardif_put(new_if);
 833         }
 834
 835         bat_priv->algo_ops->iface.disable(hard_iface);
 836         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 837
 838         /* delete all references to this hard_iface */
 839         batadv_purge_orig_ref(bat_priv);
 840         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 841         dev_put(hard_iface->soft_iface);
 842
 843         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 844         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 845
 846         /* nobody uses this interface anymore */
 847         if (!bat_priv->num_ifaces) {
 848                 batadv_gw_check_client_stop(bat_priv);
 849
 850                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 851                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 852         }
 853
 854         hard_iface->soft_iface = NULL;
 855         batadv_hardif_put(hard_iface);
 856
 857 out:
 858         if (primary_if)
 859                 batadv_hardif_put(primary_if);
 860 }
 861
 862 static struct batadv_hard_iface *
 863 batadv_hardif_add_interface(struct net_device *net_dev)
 864 {
 865         struct batadv_hard_iface *hard_iface;
 866         int ret;
 867
 868         ASSERT_RTNL();
 869
 870         if (!batadv_is_valid_iface(net_dev))
 871                 goto out;
 872
 873         dev_hold(net_dev);
 874
 875         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 876         if (!hard_iface)
 877                 goto release_dev;
 878
 879         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 880         if (ret)
 881                 goto free_if;
 882
 883         hard_iface->if_num = -1;
 884         hard_iface->net_dev = net_dev;
 885         hard_iface->soft_iface = NULL;
 886         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 887
 888         ret = batadv_debugfs_add_hardif(hard_iface);
 889         if (ret)
 890                 goto free_sysfs;
 891
 892         INIT_LIST_HEAD(&hard_iface->list);
 893         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 894
 895         spin_lock_init(&hard_iface->neigh_list_lock);
 896         kref_init(&hard_iface->refcount);
 897
 898         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 899         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 900         if (batadv_is_wifi_hardif(hard_iface))
 901                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 902
 903         batadv_v_hardif_init(hard_iface);
 904
 905         batadv_check_known_mac_addr(hard_iface->net_dev);
 906         kref_get(&hard_iface->refcount);
 907         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 908
 909         return hard_iface;
 910
 911 free_sysfs:
 912         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 913 free_if:
 914         kfree(hard_iface);
 915 release_dev:
 916         dev_put(net_dev);
 917 out:
 918         return NULL;
 919 }
 920
 921 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 922 {
 923         ASSERT_RTNL();
 924
 925         /* first deactivate interface */
 926         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 927                 batadv_hardif_disable_interface(hard_iface,
 928                                                 BATADV_IF_CLEANUP_KEEP);
 929
 930         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 931                 return;
 932
 933         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 934         batadv_debugfs_del_hardif(hard_iface);
 935         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 936         batadv_hardif_put(hard_iface);
 937 }
 938
 939 void batadv_hardif_remove_interfaces(void)
 940 {
 941         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 942
 943         rtnl_lock();
 944         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 945                                  &batadv_hardif_list, list) {
 946                 list_del_rcu(&hard_iface->list);
 947                 batadv_hardif_remove_interface(hard_iface);
 948         }
 949         rtnl_unlock();
 950 }
 951
 952 static int batadv_hard_if_event(struct notifier_block *this,
 953                                 unsigned long event, void *ptr)
 954 {
 955         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 956         struct batadv_hard_iface *hard_iface;
 957         struct batadv_hard_iface *primary_if = NULL;
 958         struct batadv_priv *bat_priv;
 959
 960         if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
 961                 batadv_sysfs_add_meshif(net_dev);
 962                 bat_priv = netdev_priv(net_dev);
 963                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 964                 return NOTIFY_DONE;
 965         }
 966
 967         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 968         if (!hard_iface && (event == NETDEV_REGISTER ||
 969                             event == NETDEV_POST_TYPE_CHANGE))
 970                 hard_iface = batadv_hardif_add_interface(net_dev);
 971
 972         if (!hard_iface)
 973                 goto out;
 974
 975         switch (event) {
 976         case NETDEV_UP:
 977                 batadv_hardif_activate_interface(hard_iface);
 978                 break;
 979         case NETDEV_GOING_DOWN:
 980         case NETDEV_DOWN:
 981                 batadv_hardif_deactivate_interface(hard_iface);
 982                 break;
 983         case NETDEV_UNREGISTER:
 984         case NETDEV_PRE_TYPE_CHANGE:
 985                 list_del_rcu(&hard_iface->list);
 986
 987                 batadv_hardif_remove_interface(hard_iface);
 988                 break;
 989         case NETDEV_CHANGEMTU:
 990                 if (hard_iface->soft_iface)
 991                         batadv_update_min_mtu(hard_iface->soft_iface);
 992                 break;
 993         case NETDEV_CHANGEADDR:
 994                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 995                         goto hardif_put;
 996
 997                 batadv_check_known_mac_addr(hard_iface->net_dev);
 998
 999                 bat_priv = netdev_priv(hard_iface->soft_iface);
1000                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1001
1002                 primary_if = batadv_primary_if_get_selected(bat_priv);
1003                 if (!primary_if)
1004                         goto hardif_put;
1005
1006                 if (hard_iface == primary_if)
1007                         batadv_primary_if_update_addr(bat_priv, NULL);
1008                 break;
1009         case NETDEV_CHANGEUPPER:
1010                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1011                 if (batadv_is_wifi_hardif(hard_iface))
1012                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1013                 break;
1014         default:
1015                 break;
1016         }
1017
1018 hardif_put:
1019         batadv_hardif_put(hard_iface);
1020 out:
1021         if (primary_if)
1022                 batadv_hardif_put(primary_if);
1023         return NOTIFY_DONE;
1024 }
1025
1026 struct notifier_block batadv_hard_if_notifier = {
1027         .notifier_call = batadv_hard_if_event,
1028 };