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