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