net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2018  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/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/gfp.h>
  26 #include <linux/if.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kref.h>
  31 #include <linux/list.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/printk.h>
  34 #include <linux/rculist.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <net/net_namespace.h>
  39 #include <net/rtnetlink.h>
  40 #include <uapi/linux/batadv_packet.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 "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 /**
  70  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  71  * @net_dev: net_device to search for
  72  *
  73  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  74  */
  75 struct batadv_hard_iface *
  76 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  77 {
  78         struct batadv_hard_iface *hard_iface;
  79
  80         rcu_read_lock();
  81         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  82                 if (hard_iface->net_dev == net_dev &&
  83                     kref_get_unless_zero(&hard_iface->refcount))
  84                         goto out;
  85         }
  86
  87         hard_iface = NULL;
  88
  89 out:
  90         rcu_read_unlock();
  91         return hard_iface;
  92 }
  93
  94 /**
  95  * batadv_getlink_net() - return link net namespace (of use fallback)
  96  * @netdev: net_device to check
  97  * @fallback_net: return in case get_link_net is not available for @netdev
  98  *
  99  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
 100  */
 101 static struct net *batadv_getlink_net(const struct net_device *netdev,
 102                                       struct net *fallback_net)
 103 {
 104         if (!netdev->rtnl_link_ops)
 105                 return fallback_net;
 106
 107         if (!netdev->rtnl_link_ops->get_link_net)
 108                 return fallback_net;
 109
 110         return netdev->rtnl_link_ops->get_link_net(netdev);
 111 }
 112
 113 /**
 114  * batadv_mutual_parents() - check if two devices are each others parent
 115  * @dev1: 1st net dev
 116  * @net1: 1st devices netns
 117  * @dev2: 2nd net dev
 118  * @net2: 2nd devices netns
 119  *
 120  * veth devices come in pairs and each is the parent of the other!
 121  *
 122  * Return: true if the devices are each others parent, otherwise false
 123  */
 124 static bool batadv_mutual_parents(const struct net_device *dev1,
 125                                   struct net *net1,
 126                                   const struct net_device *dev2,
 127                                   struct net *net2)
 128 {
 129         int dev1_parent_iflink = dev_get_iflink(dev1);
 130         int dev2_parent_iflink = dev_get_iflink(dev2);
 131         const struct net *dev1_parent_net;
 132         const struct net *dev2_parent_net;
 133
 134         dev1_parent_net = batadv_getlink_net(dev1, net1);
 135         dev2_parent_net = batadv_getlink_net(dev2, net2);
 136
 137         if (!dev1_parent_iflink || !dev2_parent_iflink)
 138                 return false;
 139
 140         return (dev1_parent_iflink == dev2->ifindex) &&
 141                (dev2_parent_iflink == dev1->ifindex) &&
 142                net_eq(dev1_parent_net, net2) &&
 143                net_eq(dev2_parent_net, net1);
 144 }
 145
 146 /**
 147  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 148  * @net_dev: the device to check
 149  *
 150  * If the user creates any virtual device on top of a batman-adv interface, it
 151  * is important to prevent this new interface to be used to create a new mesh
 152  * network (this behaviour would lead to a batman-over-batman configuration).
 153  * This function recursively checks all the fathers of the device passed as
 154  * argument looking for a batman-adv soft interface.
 155  *
 156  * Return: true if the device is descendant of a batman-adv mesh interface (or
 157  * if it is a batman-adv interface itself), false otherwise
 158  */
 159 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 160 {
 161         struct net *net = dev_net(net_dev);
 162         struct net_device *parent_dev;
 163         struct net *parent_net;
 164         bool ret;
 165
 166         /* check if this is a batman-adv mesh interface */
 167         if (batadv_softif_is_valid(net_dev))
 168                 return true;
 169
 170         /* no more parents..stop recursion */
 171         if (dev_get_iflink(net_dev) == 0 ||
 172             dev_get_iflink(net_dev) == net_dev->ifindex)
 173                 return false;
 174
 175         parent_net = batadv_getlink_net(net_dev, net);
 176
 177         /* recurse over the parent device */
 178         parent_dev = __dev_get_by_index((struct net *)parent_net,
 179                                         dev_get_iflink(net_dev));
 180         /* if we got a NULL parent_dev there is something broken.. */
 181         if (!parent_dev) {
 182                 pr_err("Cannot find parent device\n");
 183                 return false;
 184         }
 185
 186         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 187                 return false;
 188
 189         ret = batadv_is_on_batman_iface(parent_dev);
 190
 191         return ret;
 192 }
 193
 194 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 195 {
 196         if (net_dev->flags & IFF_LOOPBACK)
 197                 return false;
 198
 199         if (net_dev->type != ARPHRD_ETHER)
 200                 return false;
 201
 202         if (net_dev->addr_len != ETH_ALEN)
 203                 return false;
 204
 205         /* no batman over batman */
 206         if (batadv_is_on_batman_iface(net_dev))
 207                 return false;
 208
 209         return true;
 210 }
 211
 212 /**
 213  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 214  *  interface on top of another 'real' interface
 215  * @netdev: the device to check
 216  *
 217  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 218  * instead of this.
 219  *
 220  * Return: the 'real' net device or the original net device and NULL in case
 221  *  of an error.
 222  */
 223 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 224 {
 225         struct batadv_hard_iface *hard_iface = NULL;
 226         struct net_device *real_netdev = NULL;
 227         struct net *real_net;
 228         struct net *net;
 229         int ifindex;
 230
 231         ASSERT_RTNL();
 232
 233         if (!netdev)
 234                 return NULL;
 235
 236         if (netdev->ifindex == dev_get_iflink(netdev)) {
 237                 dev_hold(netdev);
 238                 return netdev;
 239         }
 240
 241         hard_iface = batadv_hardif_get_by_netdev(netdev);
 242         if (!hard_iface || !hard_iface->soft_iface)
 243                 goto out;
 244
 245         net = dev_net(hard_iface->soft_iface);
 246         ifindex = dev_get_iflink(netdev);
 247         real_net = batadv_getlink_net(netdev, net);
 248         real_netdev = dev_get_by_index(real_net, ifindex);
 249
 250 out:
 251         if (hard_iface)
 252                 batadv_hardif_put(hard_iface);
 253         return real_netdev;
 254 }
 255
 256 /**
 257  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 258  *  interface on top of another 'real' interface
 259  * @net_device: the device to check
 260  *
 261  * Return: the 'real' net device or the original net device and NULL in case
 262  *  of an error.
 263  */
 264 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 265 {
 266         struct net_device *real_netdev;
 267
 268         rtnl_lock();
 269         real_netdev = batadv_get_real_netdevice(net_device);
 270         rtnl_unlock();
 271
 272         return real_netdev;
 273 }
 274
 275 /**
 276  * batadv_is_wext_netdev() - check if the given net_device struct is a
 277  *  wext wifi interface
 278  * @net_device: the device to check
 279  *
 280  * Return: true if the net device is a wext wireless device, false
 281  *  otherwise.
 282  */
 283 static bool batadv_is_wext_netdev(struct net_device *net_device)
 284 {
 285         if (!net_device)
 286                 return false;
 287
 288 #ifdef CONFIG_WIRELESS_EXT
 289         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 290          * check for wireless_handlers != NULL
 291          */
 292         if (net_device->wireless_handlers)
 293                 return true;
 294 #endif
 295
 296         return false;
 297 }
 298
 299 /**
 300  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 301  *  cfg80211 wifi interface
 302  * @net_device: the device to check
 303  *
 304  * Return: true if the net device is a cfg80211 wireless device, false
 305  *  otherwise.
 306  */
 307 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 308 {
 309         if (!net_device)
 310                 return false;
 311
 312         /* cfg80211 drivers have to set ieee80211_ptr */
 313         if (net_device->ieee80211_ptr)
 314                 return true;
 315
 316         return false;
 317 }
 318
 319 /**
 320  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 321  * @net_device: the device to check
 322  *
 323  * Return: batadv_hard_iface_wifi_flags flags of the device
 324  */
 325 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 326 {
 327         u32 wifi_flags = 0;
 328         struct net_device *real_netdev;
 329
 330         if (batadv_is_wext_netdev(net_device))
 331                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 332
 333         if (batadv_is_cfg80211_netdev(net_device))
 334                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 335
 336         real_netdev = batadv_get_real_netdevice(net_device);
 337         if (!real_netdev)
 338                 return wifi_flags;
 339
 340         if (real_netdev == net_device)
 341                 goto out;
 342
 343         if (batadv_is_wext_netdev(real_netdev))
 344                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 345
 346         if (batadv_is_cfg80211_netdev(real_netdev))
 347                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 348
 349 out:
 350         dev_put(real_netdev);
 351         return wifi_flags;
 352 }
 353
 354 /**
 355  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 356  *  interface
 357  * @hard_iface: the device to check
 358  *
 359  * Return: true if the net device is a cfg80211 wireless device, false
 360  *  otherwise.
 361  */
 362 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 363 {
 364         u32 allowed_flags = 0;
 365
 366         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 367         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 368
 369         return !!(hard_iface->wifi_flags & allowed_flags);
 370 }
 371
 372 /**
 373  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 374  * @hard_iface: the device to check
 375  *
 376  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 377  */
 378 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 379 {
 380         if (!hard_iface)
 381                 return false;
 382
 383         return hard_iface->wifi_flags != 0;
 384 }
 385
 386 /**
 387  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 388  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 389  * @orig_addr: the originator of this packet
 390  * @orig_neigh: originator address of the forwarder we just got the packet from
 391  *  (NULL if we originated)
 392  *
 393  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 394  *
 395  * Return:
 396  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 397  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 398  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 399  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 400  */
 401 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 402                                u8 *orig_addr, u8 *orig_neigh)
 403 {
 404         struct batadv_hardif_neigh_node *hardif_neigh;
 405         struct hlist_node *first;
 406         int ret = BATADV_HARDIF_BCAST_OK;
 407
 408         rcu_read_lock();
 409
 410         /* 0 neighbors -> no (re)broadcast */
 411         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 412         if (!first) {
 413                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 414                 goto out;
 415         }
 416
 417         /* >1 neighbors -> (re)brodcast */
 418         if (rcu_dereference(hlist_next_rcu(first)))
 419                 goto out;
 420
 421         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 422                                    list);
 423
 424         /* 1 neighbor, is the originator -> no rebroadcast */
 425         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 426                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 427         /* 1 neighbor, is the one we received from -> no rebroadcast */
 428         } else if (orig_neigh &&
 429                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 430                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 431         }
 432
 433 out:
 434         rcu_read_unlock();
 435         return ret;
 436 }
 437
 438 static struct batadv_hard_iface *
 439 batadv_hardif_get_active(const struct net_device *soft_iface)
 440 {
 441         struct batadv_hard_iface *hard_iface;
 442
 443         rcu_read_lock();
 444         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 445                 if (hard_iface->soft_iface != soft_iface)
 446                         continue;
 447
 448                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 449                     kref_get_unless_zero(&hard_iface->refcount))
 450                         goto out;
 451         }
 452
 453         hard_iface = NULL;
 454
 455 out:
 456         rcu_read_unlock();
 457         return hard_iface;
 458 }
 459
 460 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 461                                           struct batadv_hard_iface *oldif)
 462 {
 463         struct batadv_hard_iface *primary_if;
 464
 465         primary_if = batadv_primary_if_get_selected(bat_priv);
 466         if (!primary_if)
 467                 goto out;
 468
 469         batadv_dat_init_own_addr(bat_priv, primary_if);
 470         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 471 out:
 472         if (primary_if)
 473                 batadv_hardif_put(primary_if);
 474 }
 475
 476 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 477                                      struct batadv_hard_iface *new_hard_iface)
 478 {
 479         struct batadv_hard_iface *curr_hard_iface;
 480
 481         ASSERT_RTNL();
 482
 483         if (new_hard_iface)
 484                 kref_get(&new_hard_iface->refcount);
 485
 486         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 487         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 488
 489         if (!new_hard_iface)
 490                 goto out;
 491
 492         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 493         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 494
 495 out:
 496         if (curr_hard_iface)
 497                 batadv_hardif_put(curr_hard_iface);
 498 }
 499
 500 static bool
 501 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 502 {
 503         if (hard_iface->net_dev->flags & IFF_UP)
 504                 return true;
 505
 506         return false;
 507 }
 508
 509 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 510 {
 511         const struct batadv_hard_iface *hard_iface;
 512
 513         rcu_read_lock();
 514         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 515                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 516                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 517                         continue;
 518
 519                 if (hard_iface->net_dev == net_dev)
 520                         continue;
 521
 522                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 523                                         net_dev->dev_addr))
 524                         continue;
 525
 526                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 527                         net_dev->dev_addr, hard_iface->net_dev->name);
 528                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 529         }
 530         rcu_read_unlock();
 531 }
 532
 533 /**
 534  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 535  * @soft_iface: netdev struct of the mesh interface
 536  */
 537 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 538 {
 539         const struct batadv_hard_iface *hard_iface;
 540         unsigned short lower_header_len = ETH_HLEN;
 541         unsigned short lower_headroom = 0;
 542         unsigned short lower_tailroom = 0;
 543         unsigned short needed_headroom;
 544
 545         rcu_read_lock();
 546         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 547                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 548                         continue;
 549
 550                 if (hard_iface->soft_iface != soft_iface)
 551                         continue;
 552
 553                 lower_header_len = max_t(unsigned short, lower_header_len,
 554                                          hard_iface->net_dev->hard_header_len);
 555
 556                 lower_headroom = max_t(unsigned short, lower_headroom,
 557                                        hard_iface->net_dev->needed_headroom);
 558
 559                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 560                                        hard_iface->net_dev->needed_tailroom);
 561         }
 562         rcu_read_unlock();
 563
 564         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 565         needed_headroom += batadv_max_header_len();
 566
 567         soft_iface->needed_headroom = needed_headroom;
 568         soft_iface->needed_tailroom = lower_tailroom;
 569 }
 570
 571 /**
 572  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 573  * @soft_iface: netdev struct of the soft interface
 574  *
 575  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 576  *  slave interfaces)
 577  */
 578 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 579 {
 580         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 581         const struct batadv_hard_iface *hard_iface;
 582         int min_mtu = INT_MAX;
 583
 584         rcu_read_lock();
 585         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 586                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 587                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 588                         continue;
 589
 590                 if (hard_iface->soft_iface != soft_iface)
 591                         continue;
 592
 593                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 594         }
 595         rcu_read_unlock();
 596
 597         if (atomic_read(&bat_priv->fragmentation) == 0)
 598                 goto out;
 599
 600         /* with fragmentation enabled the maximum size of internally generated
 601          * packets such as translation table exchanges or tvlv containers, etc
 602          * has to be calculated
 603          */
 604         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 605         min_mtu -= sizeof(struct batadv_frag_packet);
 606         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 607
 608 out:
 609         /* report to the other components the maximum amount of bytes that
 610          * batman-adv can send over the wire (without considering the payload
 611          * overhead). For example, this value is used by TT to compute the
 612          * maximum local table table size
 613          */
 614         atomic_set(&bat_priv->packet_size_max, min_mtu);
 615
 616         /* the real soft-interface MTU is computed by removing the payload
 617          * overhead from the maximum amount of bytes that was just computed.
 618          *
 619          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 620          */
 621         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 622 }
 623
 624 /**
 625  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 626  *  MTU appeared
 627  * @soft_iface: netdev struct of the soft interface
 628  */
 629 void batadv_update_min_mtu(struct net_device *soft_iface)
 630 {
 631         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 632
 633         /* Check if the local translate table should be cleaned up to match a
 634          * new (and smaller) MTU.
 635          */
 636         batadv_tt_local_resize_to_mtu(soft_iface);
 637 }
 638
 639 static void
 640 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 641 {
 642         struct batadv_priv *bat_priv;
 643         struct batadv_hard_iface *primary_if = NULL;
 644
 645         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 646                 goto out;
 647
 648         bat_priv = netdev_priv(hard_iface->soft_iface);
 649
 650         bat_priv->algo_ops->iface.update_mac(hard_iface);
 651         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 652
 653         /* the first active interface becomes our primary interface or
 654          * the next active interface after the old primary interface was removed
 655          */
 656         primary_if = batadv_primary_if_get_selected(bat_priv);
 657         if (!primary_if)
 658                 batadv_primary_if_select(bat_priv, hard_iface);
 659
 660         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 661                     hard_iface->net_dev->name);
 662
 663         batadv_update_min_mtu(hard_iface->soft_iface);
 664
 665         if (bat_priv->algo_ops->iface.activate)
 666                 bat_priv->algo_ops->iface.activate(hard_iface);
 667
 668 out:
 669         if (primary_if)
 670                 batadv_hardif_put(primary_if);
 671 }
 672
 673 static void
 674 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 675 {
 676         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 677             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 678                 return;
 679
 680         hard_iface->if_status = BATADV_IF_INACTIVE;
 681
 682         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 683                     hard_iface->net_dev->name);
 684
 685         batadv_update_min_mtu(hard_iface->soft_iface);
 686 }
 687
 688 /**
 689  * batadv_master_del_slave() - remove hard_iface from the current master iface
 690  * @slave: the interface enslaved in another master
 691  * @master: the master from which slave has to be removed
 692  *
 693  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 694  * is free'd and master can correctly change its internal state.
 695  *
 696  * Return: 0 on success, a negative value representing the error otherwise
 697  */
 698 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 699                                    struct net_device *master)
 700 {
 701         int ret;
 702
 703         if (!master)
 704                 return 0;
 705
 706         ret = -EBUSY;
 707         if (master->netdev_ops->ndo_del_slave)
 708                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 709
 710         return ret;
 711 }
 712
 713 /**
 714  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 715  * @hard_iface: hard interface to add to soft interface
 716  * @net: the applicable net namespace
 717  * @iface_name: name of the soft interface
 718  *
 719  * Return: 0 on success or negative error number in case of failure
 720  */
 721 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 722                                    struct net *net, const char *iface_name)
 723 {
 724         struct batadv_priv *bat_priv;
 725         struct net_device *soft_iface, *master;
 726         __be16 ethertype = htons(ETH_P_BATMAN);
 727         int max_header_len = batadv_max_header_len();
 728         int ret;
 729
 730         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 731                 goto out;
 732
 733         kref_get(&hard_iface->refcount);
 734
 735         soft_iface = dev_get_by_name(net, iface_name);
 736
 737         if (!soft_iface) {
 738                 soft_iface = batadv_softif_create(net, iface_name);
 739
 740                 if (!soft_iface) {
 741                         ret = -ENOMEM;
 742                         goto err;
 743                 }
 744
 745                 /* dev_get_by_name() increases the reference counter for us */
 746                 dev_hold(soft_iface);
 747         }
 748
 749         if (!batadv_softif_is_valid(soft_iface)) {
 750                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 751                        soft_iface->name);
 752                 ret = -EINVAL;
 753                 goto err_dev;
 754         }
 755
 756         /* check if the interface is enslaved in another virtual one and
 757          * in that case unlink it first
 758          */
 759         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 760         ret = batadv_master_del_slave(hard_iface, master);
 761         if (ret)
 762                 goto err_dev;
 763
 764         hard_iface->soft_iface = soft_iface;
 765         bat_priv = netdev_priv(hard_iface->soft_iface);
 766
 767         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 768                                            soft_iface, NULL, NULL, NULL);
 769         if (ret)
 770                 goto err_dev;
 771
 772         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 773         if (ret < 0)
 774                 goto err_upper;
 775
 776         hard_iface->if_status = BATADV_IF_INACTIVE;
 777
 778         kref_get(&hard_iface->refcount);
 779         hard_iface->batman_adv_ptype.type = ethertype;
 780         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 781         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 782         dev_add_pack(&hard_iface->batman_adv_ptype);
 783
 784         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 785                     hard_iface->net_dev->name);
 786
 787         if (atomic_read(&bat_priv->fragmentation) &&
 788             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 789                 batadv_info(hard_iface->soft_iface,
 790                             "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",
 791                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 792                             ETH_DATA_LEN + max_header_len);
 793
 794         if (!atomic_read(&bat_priv->fragmentation) &&
 795             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 796                 batadv_info(hard_iface->soft_iface,
 797                             "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",
 798                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 799                             ETH_DATA_LEN + max_header_len);
 800
 801         if (batadv_hardif_is_iface_up(hard_iface))
 802                 batadv_hardif_activate_interface(hard_iface);
 803         else
 804                 batadv_err(hard_iface->soft_iface,
 805                            "Not using interface %s (retrying later): interface not active\n",
 806                            hard_iface->net_dev->name);
 807
 808         batadv_hardif_recalc_extra_skbroom(soft_iface);
 809
 810 out:
 811         return 0;
 812
 813 err_upper:
 814         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 815 err_dev:
 816         hard_iface->soft_iface = NULL;
 817         dev_put(soft_iface);
 818 err:
 819         batadv_hardif_put(hard_iface);
 820         return ret;
 821 }
 822
 823 /**
 824  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 825  * @soft_iface: soft interface to check
 826  *
 827  * This function is only using RCU for locking - the result can therefore be
 828  * off when another functions is modifying the list at the same time. The
 829  * caller can use the rtnl_lock to make sure that the count is accurate.
 830  *
 831  * Return: number of connected/enslaved hard interfaces
 832  */
 833 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 834 {
 835         struct batadv_hard_iface *hard_iface;
 836         size_t count = 0;
 837
 838         rcu_read_lock();
 839         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 840                 if (hard_iface->soft_iface != soft_iface)
 841                         continue;
 842
 843                 count++;
 844         }
 845         rcu_read_unlock();
 846
 847         return count;
 848 }
 849
 850 /**
 851  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 852  * @hard_iface: hard interface to be removed
 853  * @autodel: whether to delete soft interface when it doesn't contain any other
 854  *  slave interfaces
 855  */
 856 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 857                                      enum batadv_hard_if_cleanup autodel)
 858 {
 859         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 860         struct batadv_hard_iface *primary_if = NULL;
 861
 862         batadv_hardif_deactivate_interface(hard_iface);
 863
 864         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 865                 goto out;
 866
 867         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 868                     hard_iface->net_dev->name);
 869         dev_remove_pack(&hard_iface->batman_adv_ptype);
 870         batadv_hardif_put(hard_iface);
 871
 872         primary_if = batadv_primary_if_get_selected(bat_priv);
 873         if (hard_iface == primary_if) {
 874                 struct batadv_hard_iface *new_if;
 875
 876                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 877                 batadv_primary_if_select(bat_priv, new_if);
 878
 879                 if (new_if)
 880                         batadv_hardif_put(new_if);
 881         }
 882
 883         bat_priv->algo_ops->iface.disable(hard_iface);
 884         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 885
 886         /* delete all references to this hard_iface */
 887         batadv_purge_orig_ref(bat_priv);
 888         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 889         dev_put(hard_iface->soft_iface);
 890
 891         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 892         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 893
 894         /* nobody uses this interface anymore */
 895         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 896                 batadv_gw_check_client_stop(bat_priv);
 897
 898                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 899                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 900         }
 901
 902         hard_iface->soft_iface = NULL;
 903         batadv_hardif_put(hard_iface);
 904
 905 out:
 906         if (primary_if)
 907                 batadv_hardif_put(primary_if);
 908 }
 909
 910 static struct batadv_hard_iface *
 911 batadv_hardif_add_interface(struct net_device *net_dev)
 912 {
 913         struct batadv_hard_iface *hard_iface;
 914         int ret;
 915
 916         ASSERT_RTNL();
 917
 918         if (!batadv_is_valid_iface(net_dev))
 919                 goto out;
 920
 921         dev_hold(net_dev);
 922
 923         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 924         if (!hard_iface)
 925                 goto release_dev;
 926
 927         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 928         if (ret)
 929                 goto free_if;
 930
 931         hard_iface->net_dev = net_dev;
 932         hard_iface->soft_iface = NULL;
 933         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 934
 935         ret = batadv_debugfs_add_hardif(hard_iface);
 936         if (ret)
 937                 goto free_sysfs;
 938
 939         INIT_LIST_HEAD(&hard_iface->list);
 940         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 941
 942         spin_lock_init(&hard_iface->neigh_list_lock);
 943         kref_init(&hard_iface->refcount);
 944
 945         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 946         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 947         if (batadv_is_wifi_hardif(hard_iface))
 948                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 949
 950         batadv_v_hardif_init(hard_iface);
 951
 952         batadv_check_known_mac_addr(hard_iface->net_dev);
 953         kref_get(&hard_iface->refcount);
 954         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 955         batadv_hardif_generation++;
 956
 957         return hard_iface;
 958
 959 free_sysfs:
 960         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 961 free_if:
 962         kfree(hard_iface);
 963 release_dev:
 964         dev_put(net_dev);
 965 out:
 966         return NULL;
 967 }
 968
 969 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 970 {
 971         ASSERT_RTNL();
 972
 973         /* first deactivate interface */
 974         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 975                 batadv_hardif_disable_interface(hard_iface,
 976                                                 BATADV_IF_CLEANUP_KEEP);
 977
 978         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 979                 return;
 980
 981         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 982         batadv_debugfs_del_hardif(hard_iface);
 983         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 984         batadv_hardif_put(hard_iface);
 985 }
 986
 987 /**
 988  * batadv_hardif_remove_interfaces() - Remove all hard interfaces
 989  */
 990 void batadv_hardif_remove_interfaces(void)
 991 {
 992         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 993
 994         rtnl_lock();
 995         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 996                                  &batadv_hardif_list, list) {
 997                 list_del_rcu(&hard_iface->list);
 998                 batadv_hardif_generation++;
 999                 batadv_hardif_remove_interface(hard_iface);
1000         }
1001         rtnl_unlock();
1002 }
1003
1004 /**
1005  * batadv_hard_if_event_softif() - Handle events for soft interfaces
1006  * @event: NETDEV_* event to handle
1007  * @net_dev: net_device which generated an event
1008  *
1009  * Return: NOTIFY_* result
1010  */
1011 static int batadv_hard_if_event_softif(unsigned long event,
1012                                        struct net_device *net_dev)
1013 {
1014         struct batadv_priv *bat_priv;
1015
1016         switch (event) {
1017         case NETDEV_REGISTER:
1018                 batadv_sysfs_add_meshif(net_dev);
1019                 bat_priv = netdev_priv(net_dev);
1020                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1021                 break;
1022         case NETDEV_CHANGENAME:
1023                 batadv_debugfs_rename_meshif(net_dev);
1024                 break;
1025         }
1026
1027         return NOTIFY_DONE;
1028 }
1029
1030 static int batadv_hard_if_event(struct notifier_block *this,
1031                                 unsigned long event, void *ptr)
1032 {
1033         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1034         struct batadv_hard_iface *hard_iface;
1035         struct batadv_hard_iface *primary_if = NULL;
1036         struct batadv_priv *bat_priv;
1037
1038         if (batadv_softif_is_valid(net_dev))
1039                 return batadv_hard_if_event_softif(event, net_dev);
1040
1041         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1042         if (!hard_iface && (event == NETDEV_REGISTER ||
1043                             event == NETDEV_POST_TYPE_CHANGE))
1044                 hard_iface = batadv_hardif_add_interface(net_dev);
1045
1046         if (!hard_iface)
1047                 goto out;
1048
1049         switch (event) {
1050         case NETDEV_UP:
1051                 batadv_hardif_activate_interface(hard_iface);
1052                 break;
1053         case NETDEV_GOING_DOWN:
1054         case NETDEV_DOWN:
1055                 batadv_hardif_deactivate_interface(hard_iface);
1056                 break;
1057         case NETDEV_UNREGISTER:
1058         case NETDEV_PRE_TYPE_CHANGE:
1059                 list_del_rcu(&hard_iface->list);
1060                 batadv_hardif_generation++;
1061
1062                 batadv_hardif_remove_interface(hard_iface);
1063                 break;
1064         case NETDEV_CHANGEMTU:
1065                 if (hard_iface->soft_iface)
1066                         batadv_update_min_mtu(hard_iface->soft_iface);
1067                 break;
1068         case NETDEV_CHANGEADDR:
1069                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1070                         goto hardif_put;
1071
1072                 batadv_check_known_mac_addr(hard_iface->net_dev);
1073
1074                 bat_priv = netdev_priv(hard_iface->soft_iface);
1075                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1076
1077                 primary_if = batadv_primary_if_get_selected(bat_priv);
1078                 if (!primary_if)
1079                         goto hardif_put;
1080
1081                 if (hard_iface == primary_if)
1082                         batadv_primary_if_update_addr(bat_priv, NULL);
1083                 break;
1084         case NETDEV_CHANGEUPPER:
1085                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1086                 if (batadv_is_wifi_hardif(hard_iface))
1087                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1088                 break;
1089         case NETDEV_CHANGENAME:
1090                 batadv_debugfs_rename_hardif(hard_iface);
1091                 break;
1092         default:
1093                 break;
1094         }
1095
1096 hardif_put:
1097         batadv_hardif_put(hard_iface);
1098 out:
1099         if (primary_if)
1100                 batadv_hardif_put(primary_if);
1101         return NOTIFY_DONE;
1102 }
1103
1104 struct notifier_block batadv_hard_if_notifier = {
1105         .notifier_call = batadv_hard_if_event,
1106 };