net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "hard-interface.h"
  20 #include "main.h"
  21
  22 #include <linux/atomic.h>
  23 #include <linux/bug.h>
  24 #include <linux/byteorder/generic.h>
  25 #include <linux/errno.h>
  26 #include <linux/fs.h>
  27 #include <linux/if.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/kernel.h>
  31 #include <linux/kref.h>
  32 #include <linux/list.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/printk.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rtnetlink.h>
  37 #include <linux/slab.h>
  38 #include <linux/spinlock.h>
  39 #include <net/net_namespace.h>
  40 #include <net/rtnetlink.h>
  41
  42 #include "bat_v.h"
  43 #include "bridge_loop_avoidance.h"
  44 #include "debugfs.h"
  45 #include "distributed-arp-table.h"
  46 #include "gateway_client.h"
  47 #include "log.h"
  48 #include "originator.h"
  49 #include "packet.h"
  50 #include "send.h"
  51 #include "soft-interface.h"
  52 #include "sysfs.h"
  53 #include "translation-table.h"
  54
  55 /**
  56  * batadv_hardif_release - release hard interface from lists and queue for
  57  *  free after rcu grace period
  58  * @ref: kref pointer of the hard interface
  59  */
  60 void batadv_hardif_release(struct kref *ref)
  61 {
  62         struct batadv_hard_iface *hard_iface;
  63
  64         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  65         dev_put(hard_iface->net_dev);
  66
  67         kfree_rcu(hard_iface, rcu);
  68 }
  69
  70 struct batadv_hard_iface *
  71 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  72 {
  73         struct batadv_hard_iface *hard_iface;
  74
  75         rcu_read_lock();
  76         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  77                 if (hard_iface->net_dev == net_dev &&
  78                     kref_get_unless_zero(&hard_iface->refcount))
  79                         goto out;
  80         }
  81
  82         hard_iface = NULL;
  83
  84 out:
  85         rcu_read_unlock();
  86         return hard_iface;
  87 }
  88
  89 /**
  90  * batadv_getlink_net - return link net namespace (of use fallback)
  91  * @netdev: net_device to check
  92  * @fallback_net: return in case get_link_net is not available for @netdev
  93  *
  94  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  95  */
  96 static struct net *batadv_getlink_net(const struct net_device *netdev,
  97                                       struct net *fallback_net)
  98 {
  99         if (!netdev->rtnl_link_ops)
 100                 return fallback_net;
 101
 102         if (!netdev->rtnl_link_ops->get_link_net)
 103                 return fallback_net;
 104
 105         return netdev->rtnl_link_ops->get_link_net(netdev);
 106 }
 107
 108 /**
 109  * batadv_mutual_parents - check if two devices are each others parent
 110  * @dev1: 1st net dev
 111  * @net1: 1st devices netns
 112  * @dev2: 2nd net dev
 113  * @net2: 2nd devices netns
 114  *
 115  * veth devices come in pairs and each is the parent of the other!
 116  *
 117  * Return: true if the devices are each others parent, otherwise false
 118  */
 119 static bool batadv_mutual_parents(const struct net_device *dev1,
 120                                   struct net *net1,
 121                                   const struct net_device *dev2,
 122                                   struct net *net2)
 123 {
 124         int dev1_parent_iflink = dev_get_iflink(dev1);
 125         int dev2_parent_iflink = dev_get_iflink(dev2);
 126         const struct net *dev1_parent_net;
 127         const struct net *dev2_parent_net;
 128
 129         dev1_parent_net = batadv_getlink_net(dev1, net1);
 130         dev2_parent_net = batadv_getlink_net(dev2, net2);
 131
 132         if (!dev1_parent_iflink || !dev2_parent_iflink)
 133                 return false;
 134
 135         return (dev1_parent_iflink == dev2->ifindex) &&
 136                (dev2_parent_iflink == dev1->ifindex) &&
 137                net_eq(dev1_parent_net, net2) &&
 138                net_eq(dev2_parent_net, net1);
 139 }
 140
 141 /**
 142  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
 143  * @net_dev: the device to check
 144  *
 145  * If the user creates any virtual device on top of a batman-adv interface, it
 146  * is important to prevent this new interface to be used to create a new mesh
 147  * network (this behaviour would lead to a batman-over-batman configuration).
 148  * This function recursively checks all the fathers of the device passed as
 149  * argument looking for a batman-adv soft interface.
 150  *
 151  * Return: true if the device is descendant of a batman-adv mesh interface (or
 152  * if it is a batman-adv interface itself), false otherwise
 153  */
 154 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 155 {
 156         struct net *net = dev_net(net_dev);
 157         struct net_device *parent_dev;
 158         struct net *parent_net;
 159         bool ret;
 160
 161         /* check if this is a batman-adv mesh interface */
 162         if (batadv_softif_is_valid(net_dev))
 163                 return true;
 164
 165         /* no more parents..stop recursion */
 166         if (dev_get_iflink(net_dev) == 0 ||
 167             dev_get_iflink(net_dev) == net_dev->ifindex)
 168                 return false;
 169
 170         parent_net = batadv_getlink_net(net_dev, net);
 171
 172         /* recurse over the parent device */
 173         parent_dev = __dev_get_by_index((struct net *)parent_net,
 174                                         dev_get_iflink(net_dev));
 175         /* if we got a NULL parent_dev there is something broken.. */
 176         if (WARN(!parent_dev, "Cannot find parent device"))
 177                 return false;
 178
 179         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 180                 return false;
 181
 182         ret = batadv_is_on_batman_iface(parent_dev);
 183
 184         return ret;
 185 }
 186
 187 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 188 {
 189         if (net_dev->flags & IFF_LOOPBACK)
 190                 return false;
 191
 192         if (net_dev->type != ARPHRD_ETHER)
 193                 return false;
 194
 195         if (net_dev->addr_len != ETH_ALEN)
 196                 return false;
 197
 198         /* no batman over batman */
 199         if (batadv_is_on_batman_iface(net_dev))
 200                 return false;
 201
 202         return true;
 203 }
 204
 205 /**
 206  * batadv_get_real_netdevice - check if the given netdev struct is a virtual
 207  *  interface on top of another 'real' interface
 208  * @netdev: the device to check
 209  *
 210  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 211  * instead of this.
 212  *
 213  * Return: the 'real' net device or the original net device and NULL in case
 214  *  of an error.
 215  */
 216 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 217 {
 218         struct batadv_hard_iface *hard_iface = NULL;
 219         struct net_device *real_netdev = NULL;
 220         struct net *real_net;
 221         struct net *net;
 222         int ifindex;
 223
 224         ASSERT_RTNL();
 225
 226         if (!netdev)
 227                 return NULL;
 228
 229         if (netdev->ifindex == dev_get_iflink(netdev)) {
 230                 dev_hold(netdev);
 231                 return netdev;
 232         }
 233
 234         hard_iface = batadv_hardif_get_by_netdev(netdev);
 235         if (!hard_iface || !hard_iface->soft_iface)
 236                 goto out;
 237
 238         net = dev_net(hard_iface->soft_iface);
 239         ifindex = dev_get_iflink(netdev);
 240         real_net = batadv_getlink_net(netdev, net);
 241         real_netdev = dev_get_by_index(real_net, ifindex);
 242
 243 out:
 244         if (hard_iface)
 245                 batadv_hardif_put(hard_iface);
 246         return real_netdev;
 247 }
 248
 249 /**
 250  * batadv_get_real_netdev - check if the given net_device struct is a virtual
 251  *  interface on top of another 'real' interface
 252  * @net_device: the device to check
 253  *
 254  * Return: the 'real' net device or the original net device and NULL in case
 255  *  of an error.
 256  */
 257 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 258 {
 259         struct net_device *real_netdev;
 260
 261         rtnl_lock();
 262         real_netdev = batadv_get_real_netdevice(net_device);
 263         rtnl_unlock();
 264
 265         return real_netdev;
 266 }
 267
 268 /**
 269  * batadv_is_wext_netdev - check if the given net_device struct is a
 270  *  wext wifi interface
 271  * @net_device: the device to check
 272  *
 273  * Return: true if the net device is a wext wireless device, false
 274  *  otherwise.
 275  */
 276 static bool batadv_is_wext_netdev(struct net_device *net_device)
 277 {
 278         if (!net_device)
 279                 return false;
 280
 281 #ifdef CONFIG_WIRELESS_EXT
 282         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 283          * check for wireless_handlers != NULL
 284          */
 285         if (net_device->wireless_handlers)
 286                 return true;
 287 #endif
 288
 289         return false;
 290 }
 291
 292 /**
 293  * batadv_is_cfg80211_netdev - check if the given net_device struct is a
 294  *  cfg80211 wifi interface
 295  * @net_device: the device to check
 296  *
 297  * Return: true if the net device is a cfg80211 wireless device, false
 298  *  otherwise.
 299  */
 300 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 301 {
 302         if (!net_device)
 303                 return false;
 304
 305         /* cfg80211 drivers have to set ieee80211_ptr */
 306         if (net_device->ieee80211_ptr)
 307                 return true;
 308
 309         return false;
 310 }
 311
 312 /**
 313  * batadv_wifi_flags_evaluate - calculate wifi flags for net_device
 314  * @net_device: the device to check
 315  *
 316  * Return: batadv_hard_iface_wifi_flags flags of the device
 317  */
 318 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 319 {
 320         u32 wifi_flags = 0;
 321         struct net_device *real_netdev;
 322
 323         if (batadv_is_wext_netdev(net_device))
 324                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 325
 326         if (batadv_is_cfg80211_netdev(net_device))
 327                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 328
 329         real_netdev = batadv_get_real_netdevice(net_device);
 330         if (!real_netdev)
 331                 return wifi_flags;
 332
 333         if (real_netdev == net_device)
 334                 goto out;
 335
 336         if (batadv_is_wext_netdev(real_netdev))
 337                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 338
 339         if (batadv_is_cfg80211_netdev(real_netdev))
 340                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 341
 342 out:
 343         dev_put(real_netdev);
 344         return wifi_flags;
 345 }
 346
 347 /**
 348  * batadv_is_cfg80211_hardif - check if the given hardif is a cfg80211 wifi
 349  *  interface
 350  * @hard_iface: the device to check
 351  *
 352  * Return: true if the net device is a cfg80211 wireless device, false
 353  *  otherwise.
 354  */
 355 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 356 {
 357         u32 allowed_flags = 0;
 358
 359         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 360         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 361
 362         return !!(hard_iface->wifi_flags & allowed_flags);
 363 }
 364
 365 /**
 366  * batadv_is_wifi_hardif - check if the given hardif is a wifi interface
 367  * @hard_iface: the device to check
 368  *
 369  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 370  */
 371 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 372 {
 373         if (!hard_iface)
 374                 return false;
 375
 376         return hard_iface->wifi_flags != 0;
 377 }
 378
 379 /**
 380  * batadv_hardif_no_broadcast - check whether (re)broadcast is necessary
 381  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 382  * @orig_addr: the originator of this packet
 383  * @orig_neigh: originator address of the forwarder we just got the packet from
 384  *  (NULL if we originated)
 385  *
 386  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 387  *
 388  * Return:
 389  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 390  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 391  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 392  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 393  */
 394 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 395                                u8 *orig_addr, u8 *orig_neigh)
 396 {
 397         struct batadv_hardif_neigh_node *hardif_neigh;
 398         struct hlist_node *first;
 399         int ret = BATADV_HARDIF_BCAST_OK;
 400
 401         rcu_read_lock();
 402
 403         /* 0 neighbors -> no (re)broadcast */
 404         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 405         if (!first) {
 406                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 407                 goto out;
 408         }
 409
 410         /* >1 neighbors -> (re)brodcast */
 411         if (rcu_dereference(hlist_next_rcu(first)))
 412                 goto out;
 413
 414         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 415                                    list);
 416
 417         /* 1 neighbor, is the originator -> no rebroadcast */
 418         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 419                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 420         /* 1 neighbor, is the one we received from -> no rebroadcast */
 421         } else if (orig_neigh &&
 422                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 423                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 424         }
 425
 426 out:
 427         rcu_read_unlock();
 428         return ret;
 429 }
 430
 431 static struct batadv_hard_iface *
 432 batadv_hardif_get_active(const struct net_device *soft_iface)
 433 {
 434         struct batadv_hard_iface *hard_iface;
 435
 436         rcu_read_lock();
 437         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 438                 if (hard_iface->soft_iface != soft_iface)
 439                         continue;
 440
 441                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 442                     kref_get_unless_zero(&hard_iface->refcount))
 443                         goto out;
 444         }
 445
 446         hard_iface = NULL;
 447
 448 out:
 449         rcu_read_unlock();
 450         return hard_iface;
 451 }
 452
 453 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 454                                           struct batadv_hard_iface *oldif)
 455 {
 456         struct batadv_hard_iface *primary_if;
 457
 458         primary_if = batadv_primary_if_get_selected(bat_priv);
 459         if (!primary_if)
 460                 goto out;
 461
 462         batadv_dat_init_own_addr(bat_priv, primary_if);
 463         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 464 out:
 465         if (primary_if)
 466                 batadv_hardif_put(primary_if);
 467 }
 468
 469 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 470                                      struct batadv_hard_iface *new_hard_iface)
 471 {
 472         struct batadv_hard_iface *curr_hard_iface;
 473
 474         ASSERT_RTNL();
 475
 476         if (new_hard_iface)
 477                 kref_get(&new_hard_iface->refcount);
 478
 479         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 480         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 481
 482         if (!new_hard_iface)
 483                 goto out;
 484
 485         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 486         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 487
 488 out:
 489         if (curr_hard_iface)
 490                 batadv_hardif_put(curr_hard_iface);
 491 }
 492
 493 static bool
 494 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 495 {
 496         if (hard_iface->net_dev->flags & IFF_UP)
 497                 return true;
 498
 499         return false;
 500 }
 501
 502 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 503 {
 504         const struct batadv_hard_iface *hard_iface;
 505
 506         rcu_read_lock();
 507         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 508                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 509                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 510                         continue;
 511
 512                 if (hard_iface->net_dev == net_dev)
 513                         continue;
 514
 515                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 516                                         net_dev->dev_addr))
 517                         continue;
 518
 519                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 520                         net_dev->dev_addr, hard_iface->net_dev->name);
 521                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 522         }
 523         rcu_read_unlock();
 524 }
 525
 526 /**
 527  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 528  * @soft_iface: netdev struct of the mesh interface
 529  */
 530 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 531 {
 532         const struct batadv_hard_iface *hard_iface;
 533         unsigned short lower_header_len = ETH_HLEN;
 534         unsigned short lower_headroom = 0;
 535         unsigned short lower_tailroom = 0;
 536         unsigned short needed_headroom;
 537
 538         rcu_read_lock();
 539         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 540                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 541                         continue;
 542
 543                 if (hard_iface->soft_iface != soft_iface)
 544                         continue;
 545
 546                 lower_header_len = max_t(unsigned short, lower_header_len,
 547                                          hard_iface->net_dev->hard_header_len);
 548
 549                 lower_headroom = max_t(unsigned short, lower_headroom,
 550                                        hard_iface->net_dev->needed_headroom);
 551
 552                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 553                                        hard_iface->net_dev->needed_tailroom);
 554         }
 555         rcu_read_unlock();
 556
 557         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 558         needed_headroom += batadv_max_header_len();
 559
 560         soft_iface->needed_headroom = needed_headroom;
 561         soft_iface->needed_tailroom = lower_tailroom;
 562 }
 563
 564 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 565 {
 566         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 567         const struct batadv_hard_iface *hard_iface;
 568         int min_mtu = INT_MAX;
 569
 570         rcu_read_lock();
 571         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 572                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 573                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 574                         continue;
 575
 576                 if (hard_iface->soft_iface != soft_iface)
 577                         continue;
 578
 579                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 580         }
 581         rcu_read_unlock();
 582
 583         if (atomic_read(&bat_priv->fragmentation) == 0)
 584                 goto out;
 585
 586         /* with fragmentation enabled the maximum size of internally generated
 587          * packets such as translation table exchanges or tvlv containers, etc
 588          * has to be calculated
 589          */
 590         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 591         min_mtu -= sizeof(struct batadv_frag_packet);
 592         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 593
 594 out:
 595         /* report to the other components the maximum amount of bytes that
 596          * batman-adv can send over the wire (without considering the payload
 597          * overhead). For example, this value is used by TT to compute the
 598          * maximum local table table size
 599          */
 600         atomic_set(&bat_priv->packet_size_max, min_mtu);
 601
 602         /* the real soft-interface MTU is computed by removing the payload
 603          * overhead from the maximum amount of bytes that was just computed.
 604          *
 605          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 606          */
 607         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 608 }
 609
 610 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 611 void batadv_update_min_mtu(struct net_device *soft_iface)
 612 {
 613         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 614
 615         /* Check if the local translate table should be cleaned up to match a
 616          * new (and smaller) MTU.
 617          */
 618         batadv_tt_local_resize_to_mtu(soft_iface);
 619 }
 620
 621 static void
 622 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 623 {
 624         struct batadv_priv *bat_priv;
 625         struct batadv_hard_iface *primary_if = NULL;
 626
 627         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 628                 goto out;
 629
 630         bat_priv = netdev_priv(hard_iface->soft_iface);
 631
 632         bat_priv->algo_ops->iface.update_mac(hard_iface);
 633         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 634
 635         /* the first active interface becomes our primary interface or
 636          * the next active interface after the old primary interface was removed
 637          */
 638         primary_if = batadv_primary_if_get_selected(bat_priv);
 639         if (!primary_if)
 640                 batadv_primary_if_select(bat_priv, hard_iface);
 641
 642         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 643                     hard_iface->net_dev->name);
 644
 645         batadv_update_min_mtu(hard_iface->soft_iface);
 646
 647         if (bat_priv->algo_ops->iface.activate)
 648                 bat_priv->algo_ops->iface.activate(hard_iface);
 649
 650 out:
 651         if (primary_if)
 652                 batadv_hardif_put(primary_if);
 653 }
 654
 655 static void
 656 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 657 {
 658         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 659             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 660                 return;
 661
 662         hard_iface->if_status = BATADV_IF_INACTIVE;
 663
 664         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 665                     hard_iface->net_dev->name);
 666
 667         batadv_update_min_mtu(hard_iface->soft_iface);
 668 }
 669
 670 /**
 671  * batadv_master_del_slave - remove hard_iface from the current master interface
 672  * @slave: the interface enslaved in another master
 673  * @master: the master from which slave has to be removed
 674  *
 675  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 676  * is free'd and master can correctly change its internal state.
 677  *
 678  * Return: 0 on success, a negative value representing the error otherwise
 679  */
 680 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 681                                    struct net_device *master)
 682 {
 683         int ret;
 684
 685         if (!master)
 686                 return 0;
 687
 688         ret = -EBUSY;
 689         if (master->netdev_ops->ndo_del_slave)
 690                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 691
 692         return ret;
 693 }
 694
 695 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 696                                    struct net *net, const char *iface_name)
 697 {
 698         struct batadv_priv *bat_priv;
 699         struct net_device *soft_iface, *master;
 700         __be16 ethertype = htons(ETH_P_BATMAN);
 701         int max_header_len = batadv_max_header_len();
 702         int ret;
 703
 704         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 705                 goto out;
 706
 707         kref_get(&hard_iface->refcount);
 708
 709         soft_iface = dev_get_by_name(net, iface_name);
 710
 711         if (!soft_iface) {
 712                 soft_iface = batadv_softif_create(net, iface_name);
 713
 714                 if (!soft_iface) {
 715                         ret = -ENOMEM;
 716                         goto err;
 717                 }
 718
 719                 /* dev_get_by_name() increases the reference counter for us */
 720                 dev_hold(soft_iface);
 721         }
 722
 723         if (!batadv_softif_is_valid(soft_iface)) {
 724                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 725                        soft_iface->name);
 726                 ret = -EINVAL;
 727                 goto err_dev;
 728         }
 729
 730         /* check if the interface is enslaved in another virtual one and
 731          * in that case unlink it first
 732          */
 733         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 734         ret = batadv_master_del_slave(hard_iface, master);
 735         if (ret)
 736                 goto err_dev;
 737
 738         hard_iface->soft_iface = soft_iface;
 739         bat_priv = netdev_priv(hard_iface->soft_iface);
 740
 741         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 742                                            soft_iface, NULL, NULL, NULL);
 743         if (ret)
 744                 goto err_dev;
 745
 746         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 747         if (ret < 0)
 748                 goto err_upper;
 749
 750         hard_iface->if_num = bat_priv->num_ifaces;
 751         bat_priv->num_ifaces++;
 752         hard_iface->if_status = BATADV_IF_INACTIVE;
 753         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 754         if (ret < 0) {
 755                 bat_priv->algo_ops->iface.disable(hard_iface);
 756                 bat_priv->num_ifaces--;
 757                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 758                 goto err_upper;
 759         }
 760
 761         kref_get(&hard_iface->refcount);
 762         hard_iface->batman_adv_ptype.type = ethertype;
 763         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 764         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 765         dev_add_pack(&hard_iface->batman_adv_ptype);
 766
 767         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 768                     hard_iface->net_dev->name);
 769
 770         if (atomic_read(&bat_priv->fragmentation) &&
 771             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 772                 batadv_info(hard_iface->soft_iface,
 773                             "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",
 774                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 775                             ETH_DATA_LEN + max_header_len);
 776
 777         if (!atomic_read(&bat_priv->fragmentation) &&
 778             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 779                 batadv_info(hard_iface->soft_iface,
 780                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n",
 781                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 782                             ETH_DATA_LEN + max_header_len);
 783
 784         if (batadv_hardif_is_iface_up(hard_iface))
 785                 batadv_hardif_activate_interface(hard_iface);
 786         else
 787                 batadv_err(hard_iface->soft_iface,
 788                            "Not using interface %s (retrying later): interface not active\n",
 789                            hard_iface->net_dev->name);
 790
 791         batadv_hardif_recalc_extra_skbroom(soft_iface);
 792
 793 out:
 794         return 0;
 795
 796 err_upper:
 797         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 798 err_dev:
 799         hard_iface->soft_iface = NULL;
 800         dev_put(soft_iface);
 801 err:
 802         batadv_hardif_put(hard_iface);
 803         return ret;
 804 }
 805
 806 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 807                                      enum batadv_hard_if_cleanup autodel)
 808 {
 809         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 810         struct batadv_hard_iface *primary_if = NULL;
 811
 812         batadv_hardif_deactivate_interface(hard_iface);
 813
 814         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 815                 goto out;
 816
 817         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 818                     hard_iface->net_dev->name);
 819         dev_remove_pack(&hard_iface->batman_adv_ptype);
 820         batadv_hardif_put(hard_iface);
 821
 822         bat_priv->num_ifaces--;
 823         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 824
 825         primary_if = batadv_primary_if_get_selected(bat_priv);
 826         if (hard_iface == primary_if) {
 827                 struct batadv_hard_iface *new_if;
 828
 829                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 830                 batadv_primary_if_select(bat_priv, new_if);
 831
 832                 if (new_if)
 833                         batadv_hardif_put(new_if);
 834         }
 835
 836         bat_priv->algo_ops->iface.disable(hard_iface);
 837         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 838
 839         /* delete all references to this hard_iface */
 840         batadv_purge_orig_ref(bat_priv);
 841         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 842         dev_put(hard_iface->soft_iface);
 843
 844         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 845         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 846
 847         /* nobody uses this interface anymore */
 848         if (!bat_priv->num_ifaces) {
 849                 batadv_gw_check_client_stop(bat_priv);
 850
 851                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 852                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 853         }
 854
 855         hard_iface->soft_iface = NULL;
 856         batadv_hardif_put(hard_iface);
 857
 858 out:
 859         if (primary_if)
 860                 batadv_hardif_put(primary_if);
 861 }
 862
 863 static struct batadv_hard_iface *
 864 batadv_hardif_add_interface(struct net_device *net_dev)
 865 {
 866         struct batadv_hard_iface *hard_iface;
 867         int ret;
 868
 869         ASSERT_RTNL();
 870
 871         if (!batadv_is_valid_iface(net_dev))
 872                 goto out;
 873
 874         dev_hold(net_dev);
 875
 876         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 877         if (!hard_iface)
 878                 goto release_dev;
 879
 880         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 881         if (ret)
 882                 goto free_if;
 883
 884         hard_iface->if_num = -1;
 885         hard_iface->net_dev = net_dev;
 886         hard_iface->soft_iface = NULL;
 887         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 888
 889         ret = batadv_debugfs_add_hardif(hard_iface);
 890         if (ret)
 891                 goto free_sysfs;
 892
 893         INIT_LIST_HEAD(&hard_iface->list);
 894         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 895
 896         spin_lock_init(&hard_iface->neigh_list_lock);
 897         kref_init(&hard_iface->refcount);
 898
 899         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 900         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 901         if (batadv_is_wifi_hardif(hard_iface))
 902                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 903
 904         batadv_v_hardif_init(hard_iface);
 905
 906         batadv_check_known_mac_addr(hard_iface->net_dev);
 907         kref_get(&hard_iface->refcount);
 908         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 909
 910         return hard_iface;
 911
 912 free_sysfs:
 913         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 914 free_if:
 915         kfree(hard_iface);
 916 release_dev:
 917         dev_put(net_dev);
 918 out:
 919         return NULL;
 920 }
 921
 922 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 923 {
 924         ASSERT_RTNL();
 925
 926         /* first deactivate interface */
 927         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 928                 batadv_hardif_disable_interface(hard_iface,
 929                                                 BATADV_IF_CLEANUP_KEEP);
 930
 931         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 932                 return;
 933
 934         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 935         batadv_debugfs_del_hardif(hard_iface);
 936         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 937         batadv_hardif_put(hard_iface);
 938 }
 939
 940 void batadv_hardif_remove_interfaces(void)
 941 {
 942         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 943
 944         rtnl_lock();
 945         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 946                                  &batadv_hardif_list, list) {
 947                 list_del_rcu(&hard_iface->list);
 948                 batadv_hardif_remove_interface(hard_iface);
 949         }
 950         rtnl_unlock();
 951 }
 952
 953 static int batadv_hard_if_event(struct notifier_block *this,
 954                                 unsigned long event, void *ptr)
 955 {
 956         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 957         struct batadv_hard_iface *hard_iface;
 958         struct batadv_hard_iface *primary_if = NULL;
 959         struct batadv_priv *bat_priv;
 960
 961         if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
 962                 batadv_sysfs_add_meshif(net_dev);
 963                 bat_priv = netdev_priv(net_dev);
 964                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 965                 return NOTIFY_DONE;
 966         }
 967
 968         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 969         if (!hard_iface && (event == NETDEV_REGISTER ||
 970                             event == NETDEV_POST_TYPE_CHANGE))
 971                 hard_iface = batadv_hardif_add_interface(net_dev);
 972
 973         if (!hard_iface)
 974                 goto out;
 975
 976         switch (event) {
 977         case NETDEV_UP:
 978                 batadv_hardif_activate_interface(hard_iface);
 979                 break;
 980         case NETDEV_GOING_DOWN:
 981         case NETDEV_DOWN:
 982                 batadv_hardif_deactivate_interface(hard_iface);
 983                 break;
 984         case NETDEV_UNREGISTER:
 985         case NETDEV_PRE_TYPE_CHANGE:
 986                 list_del_rcu(&hard_iface->list);
 987
 988                 batadv_hardif_remove_interface(hard_iface);
 989                 break;
 990         case NETDEV_CHANGEMTU:
 991                 if (hard_iface->soft_iface)
 992                         batadv_update_min_mtu(hard_iface->soft_iface);
 993                 break;
 994         case NETDEV_CHANGEADDR:
 995                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 996                         goto hardif_put;
 997
 998                 batadv_check_known_mac_addr(hard_iface->net_dev);
 999
1000                 bat_priv = netdev_priv(hard_iface->soft_iface);
1001                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1002
1003                 primary_if = batadv_primary_if_get_selected(bat_priv);
1004                 if (!primary_if)
1005                         goto hardif_put;
1006
1007                 if (hard_iface == primary_if)
1008                         batadv_primary_if_update_addr(bat_priv, NULL);
1009                 break;
1010         case NETDEV_CHANGEUPPER:
1011                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1012                 if (batadv_is_wifi_hardif(hard_iface))
1013                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1014                 break;
1015         default:
1016                 break;
1017         }
1018
1019 hardif_put:
1020         batadv_hardif_put(hard_iface);
1021 out:
1022         if (primary_if)
1023                 batadv_hardif_put(primary_if);
1024         return NOTIFY_DONE;
1025 }
1026
1027 struct notifier_block batadv_hard_if_notifier = {
1028         .notifier_call = batadv_hard_if_event,
1029 };