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/bug.h>
  24 #include <linux/byteorder/generic.h>
  25 #include <linux/errno.h>
  26 #include <linux/gfp.h>
  27 #include <linux/if.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/kernel.h>
  31 #include <linux/kref.h>
  32 #include <linux/list.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/printk.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rtnetlink.h>
  37 #include <linux/slab.h>
  38 #include <linux/spinlock.h>
  39 #include <net/net_namespace.h>
  40 #include <net/rtnetlink.h>
  41 #include <uapi/linux/batadv_packet.h>
  42
  43 #include "bat_v.h"
  44 #include "bridge_loop_avoidance.h"
  45 #include "debugfs.h"
  46 #include "distributed-arp-table.h"
  47 #include "gateway_client.h"
  48 #include "log.h"
  49 #include "originator.h"
  50 #include "send.h"
  51 #include "soft-interface.h"
  52 #include "sysfs.h"
  53 #include "translation-table.h"
  54
  55 /**
  56  * batadv_hardif_release() - release hard interface from lists and queue for
  57  *  free after rcu grace period
  58  * @ref: kref pointer of the hard interface
  59  */
  60 void batadv_hardif_release(struct kref *ref)
  61 {
  62         struct batadv_hard_iface *hard_iface;
  63
  64         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  65         dev_put(hard_iface->net_dev);
  66
  67         kfree_rcu(hard_iface, rcu);
  68 }
  69
  70 /**
  71  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  72  * @net_dev: net_device to search for
  73  *
  74  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  75  */
  76 struct batadv_hard_iface *
  77 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  78 {
  79         struct batadv_hard_iface *hard_iface;
  80
  81         rcu_read_lock();
  82         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  83                 if (hard_iface->net_dev == net_dev &&
  84                     kref_get_unless_zero(&hard_iface->refcount))
  85                         goto out;
  86         }
  87
  88         hard_iface = NULL;
  89
  90 out:
  91         rcu_read_unlock();
  92         return hard_iface;
  93 }
  94
  95 /**
  96  * batadv_getlink_net() - return link net namespace (of use fallback)
  97  * @netdev: net_device to check
  98  * @fallback_net: return in case get_link_net is not available for @netdev
  99  *
 100  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
 101  */
 102 static struct net *batadv_getlink_net(const struct net_device *netdev,
 103                                       struct net *fallback_net)
 104 {
 105         if (!netdev->rtnl_link_ops)
 106                 return fallback_net;
 107
 108         if (!netdev->rtnl_link_ops->get_link_net)
 109                 return fallback_net;
 110
 111         return netdev->rtnl_link_ops->get_link_net(netdev);
 112 }
 113
 114 /**
 115  * batadv_mutual_parents() - check if two devices are each others parent
 116  * @dev1: 1st net dev
 117  * @net1: 1st devices netns
 118  * @dev2: 2nd net dev
 119  * @net2: 2nd devices netns
 120  *
 121  * veth devices come in pairs and each is the parent of the other!
 122  *
 123  * Return: true if the devices are each others parent, otherwise false
 124  */
 125 static bool batadv_mutual_parents(const struct net_device *dev1,
 126                                   struct net *net1,
 127                                   const struct net_device *dev2,
 128                                   struct net *net2)
 129 {
 130         int dev1_parent_iflink = dev_get_iflink(dev1);
 131         int dev2_parent_iflink = dev_get_iflink(dev2);
 132         const struct net *dev1_parent_net;
 133         const struct net *dev2_parent_net;
 134
 135         dev1_parent_net = batadv_getlink_net(dev1, net1);
 136         dev2_parent_net = batadv_getlink_net(dev2, net2);
 137
 138         if (!dev1_parent_iflink || !dev2_parent_iflink)
 139                 return false;
 140
 141         return (dev1_parent_iflink == dev2->ifindex) &&
 142                (dev2_parent_iflink == dev1->ifindex) &&
 143                net_eq(dev1_parent_net, net2) &&
 144                net_eq(dev2_parent_net, net1);
 145 }
 146
 147 /**
 148  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 149  * @net_dev: the device to check
 150  *
 151  * If the user creates any virtual device on top of a batman-adv interface, it
 152  * is important to prevent this new interface to be used to create a new mesh
 153  * network (this behaviour would lead to a batman-over-batman configuration).
 154  * This function recursively checks all the fathers of the device passed as
 155  * argument looking for a batman-adv soft interface.
 156  *
 157  * Return: true if the device is descendant of a batman-adv mesh interface (or
 158  * if it is a batman-adv interface itself), false otherwise
 159  */
 160 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 161 {
 162         struct net *net = dev_net(net_dev);
 163         struct net_device *parent_dev;
 164         struct net *parent_net;
 165         bool ret;
 166
 167         /* check if this is a batman-adv mesh interface */
 168         if (batadv_softif_is_valid(net_dev))
 169                 return true;
 170
 171         /* no more parents..stop recursion */
 172         if (dev_get_iflink(net_dev) == 0 ||
 173             dev_get_iflink(net_dev) == net_dev->ifindex)
 174                 return false;
 175
 176         parent_net = batadv_getlink_net(net_dev, net);
 177
 178         /* recurse over the parent device */
 179         parent_dev = __dev_get_by_index((struct net *)parent_net,
 180                                         dev_get_iflink(net_dev));
 181         /* if we got a NULL parent_dev there is something broken.. */
 182         if (WARN(!parent_dev, "Cannot find parent device"))
 183                 return false;
 184
 185         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 186                 return false;
 187
 188         ret = batadv_is_on_batman_iface(parent_dev);
 189
 190         return ret;
 191 }
 192
 193 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 194 {
 195         if (net_dev->flags & IFF_LOOPBACK)
 196                 return false;
 197
 198         if (net_dev->type != ARPHRD_ETHER)
 199                 return false;
 200
 201         if (net_dev->addr_len != ETH_ALEN)
 202                 return false;
 203
 204         /* no batman over batman */
 205         if (batadv_is_on_batman_iface(net_dev))
 206                 return false;
 207
 208         return true;
 209 }
 210
 211 /**
 212  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 213  *  interface on top of another 'real' interface
 214  * @netdev: the device to check
 215  *
 216  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 217  * instead of this.
 218  *
 219  * Return: the 'real' net device or the original net device and NULL in case
 220  *  of an error.
 221  */
 222 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 223 {
 224         struct batadv_hard_iface *hard_iface = NULL;
 225         struct net_device *real_netdev = NULL;
 226         struct net *real_net;
 227         struct net *net;
 228         int ifindex;
 229
 230         ASSERT_RTNL();
 231
 232         if (!netdev)
 233                 return NULL;
 234
 235         if (netdev->ifindex == dev_get_iflink(netdev)) {
 236                 dev_hold(netdev);
 237                 return netdev;
 238         }
 239
 240         hard_iface = batadv_hardif_get_by_netdev(netdev);
 241         if (!hard_iface || !hard_iface->soft_iface)
 242                 goto out;
 243
 244         net = dev_net(hard_iface->soft_iface);
 245         ifindex = dev_get_iflink(netdev);
 246         real_net = batadv_getlink_net(netdev, net);
 247         real_netdev = dev_get_by_index(real_net, ifindex);
 248
 249 out:
 250         if (hard_iface)
 251                 batadv_hardif_put(hard_iface);
 252         return real_netdev;
 253 }
 254
 255 /**
 256  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 257  *  interface on top of another 'real' interface
 258  * @net_device: the device to check
 259  *
 260  * Return: the 'real' net device or the original net device and NULL in case
 261  *  of an error.
 262  */
 263 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 264 {
 265         struct net_device *real_netdev;
 266
 267         rtnl_lock();
 268         real_netdev = batadv_get_real_netdevice(net_device);
 269         rtnl_unlock();
 270
 271         return real_netdev;
 272 }
 273
 274 /**
 275  * batadv_is_wext_netdev() - check if the given net_device struct is a
 276  *  wext wifi interface
 277  * @net_device: the device to check
 278  *
 279  * Return: true if the net device is a wext wireless device, false
 280  *  otherwise.
 281  */
 282 static bool batadv_is_wext_netdev(struct net_device *net_device)
 283 {
 284         if (!net_device)
 285                 return false;
 286
 287 #ifdef CONFIG_WIRELESS_EXT
 288         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 289          * check for wireless_handlers != NULL
 290          */
 291         if (net_device->wireless_handlers)
 292                 return true;
 293 #endif
 294
 295         return false;
 296 }
 297
 298 /**
 299  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 300  *  cfg80211 wifi interface
 301  * @net_device: the device to check
 302  *
 303  * Return: true if the net device is a cfg80211 wireless device, false
 304  *  otherwise.
 305  */
 306 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 307 {
 308         if (!net_device)
 309                 return false;
 310
 311         /* cfg80211 drivers have to set ieee80211_ptr */
 312         if (net_device->ieee80211_ptr)
 313                 return true;
 314
 315         return false;
 316 }
 317
 318 /**
 319  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 320  * @net_device: the device to check
 321  *
 322  * Return: batadv_hard_iface_wifi_flags flags of the device
 323  */
 324 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 325 {
 326         u32 wifi_flags = 0;
 327         struct net_device *real_netdev;
 328
 329         if (batadv_is_wext_netdev(net_device))
 330                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 331
 332         if (batadv_is_cfg80211_netdev(net_device))
 333                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 334
 335         real_netdev = batadv_get_real_netdevice(net_device);
 336         if (!real_netdev)
 337                 return wifi_flags;
 338
 339         if (real_netdev == net_device)
 340                 goto out;
 341
 342         if (batadv_is_wext_netdev(real_netdev))
 343                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 344
 345         if (batadv_is_cfg80211_netdev(real_netdev))
 346                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 347
 348 out:
 349         dev_put(real_netdev);
 350         return wifi_flags;
 351 }
 352
 353 /**
 354  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 355  *  interface
 356  * @hard_iface: the device to check
 357  *
 358  * Return: true if the net device is a cfg80211 wireless device, false
 359  *  otherwise.
 360  */
 361 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 362 {
 363         u32 allowed_flags = 0;
 364
 365         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 366         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 367
 368         return !!(hard_iface->wifi_flags & allowed_flags);
 369 }
 370
 371 /**
 372  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 373  * @hard_iface: the device to check
 374  *
 375  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 376  */
 377 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 378 {
 379         if (!hard_iface)
 380                 return false;
 381
 382         return hard_iface->wifi_flags != 0;
 383 }
 384
 385 /**
 386  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 387  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 388  * @orig_addr: the originator of this packet
 389  * @orig_neigh: originator address of the forwarder we just got the packet from
 390  *  (NULL if we originated)
 391  *
 392  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 393  *
 394  * Return:
 395  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 396  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 397  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 398  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 399  */
 400 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 401                                u8 *orig_addr, u8 *orig_neigh)
 402 {
 403         struct batadv_hardif_neigh_node *hardif_neigh;
 404         struct hlist_node *first;
 405         int ret = BATADV_HARDIF_BCAST_OK;
 406
 407         rcu_read_lock();
 408
 409         /* 0 neighbors -> no (re)broadcast */
 410         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 411         if (!first) {
 412                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 413                 goto out;
 414         }
 415
 416         /* >1 neighbors -> (re)brodcast */
 417         if (rcu_dereference(hlist_next_rcu(first)))
 418                 goto out;
 419
 420         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 421                                    list);
 422
 423         /* 1 neighbor, is the originator -> no rebroadcast */
 424         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 425                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 426         /* 1 neighbor, is the one we received from -> no rebroadcast */
 427         } else if (orig_neigh &&
 428                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 429                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 430         }
 431
 432 out:
 433         rcu_read_unlock();
 434         return ret;
 435 }
 436
 437 static struct batadv_hard_iface *
 438 batadv_hardif_get_active(const struct net_device *soft_iface)
 439 {
 440         struct batadv_hard_iface *hard_iface;
 441
 442         rcu_read_lock();
 443         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 444                 if (hard_iface->soft_iface != soft_iface)
 445                         continue;
 446
 447                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 448                     kref_get_unless_zero(&hard_iface->refcount))
 449                         goto out;
 450         }
 451
 452         hard_iface = NULL;
 453
 454 out:
 455         rcu_read_unlock();
 456         return hard_iface;
 457 }
 458
 459 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 460                                           struct batadv_hard_iface *oldif)
 461 {
 462         struct batadv_hard_iface *primary_if;
 463
 464         primary_if = batadv_primary_if_get_selected(bat_priv);
 465         if (!primary_if)
 466                 goto out;
 467
 468         batadv_dat_init_own_addr(bat_priv, primary_if);
 469         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 470 out:
 471         if (primary_if)
 472                 batadv_hardif_put(primary_if);
 473 }
 474
 475 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 476                                      struct batadv_hard_iface *new_hard_iface)
 477 {
 478         struct batadv_hard_iface *curr_hard_iface;
 479
 480         ASSERT_RTNL();
 481
 482         if (new_hard_iface)
 483                 kref_get(&new_hard_iface->refcount);
 484
 485         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 486         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 487
 488         if (!new_hard_iface)
 489                 goto out;
 490
 491         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 492         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 493
 494 out:
 495         if (curr_hard_iface)
 496                 batadv_hardif_put(curr_hard_iface);
 497 }
 498
 499 static bool
 500 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 501 {
 502         if (hard_iface->net_dev->flags & IFF_UP)
 503                 return true;
 504
 505         return false;
 506 }
 507
 508 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 509 {
 510         const struct batadv_hard_iface *hard_iface;
 511
 512         rcu_read_lock();
 513         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 514                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 515                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 516                         continue;
 517
 518                 if (hard_iface->net_dev == net_dev)
 519                         continue;
 520
 521                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 522                                         net_dev->dev_addr))
 523                         continue;
 524
 525                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 526                         net_dev->dev_addr, hard_iface->net_dev->name);
 527                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 528         }
 529         rcu_read_unlock();
 530 }
 531
 532 /**
 533  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 534  * @soft_iface: netdev struct of the mesh interface
 535  */
 536 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 537 {
 538         const struct batadv_hard_iface *hard_iface;
 539         unsigned short lower_header_len = ETH_HLEN;
 540         unsigned short lower_headroom = 0;
 541         unsigned short lower_tailroom = 0;
 542         unsigned short needed_headroom;
 543
 544         rcu_read_lock();
 545         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 546                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 547                         continue;
 548
 549                 if (hard_iface->soft_iface != soft_iface)
 550                         continue;
 551
 552                 lower_header_len = max_t(unsigned short, lower_header_len,
 553                                          hard_iface->net_dev->hard_header_len);
 554
 555                 lower_headroom = max_t(unsigned short, lower_headroom,
 556                                        hard_iface->net_dev->needed_headroom);
 557
 558                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 559                                        hard_iface->net_dev->needed_tailroom);
 560         }
 561         rcu_read_unlock();
 562
 563         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 564         needed_headroom += batadv_max_header_len();
 565
 566         soft_iface->needed_headroom = needed_headroom;
 567         soft_iface->needed_tailroom = lower_tailroom;
 568 }
 569
 570 /**
 571  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 572  * @soft_iface: netdev struct of the soft interface
 573  *
 574  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 575  *  slave interfaces)
 576  */
 577 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 578 {
 579         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 580         const struct batadv_hard_iface *hard_iface;
 581         int min_mtu = INT_MAX;
 582
 583         rcu_read_lock();
 584         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 585                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 586                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 587                         continue;
 588
 589                 if (hard_iface->soft_iface != soft_iface)
 590                         continue;
 591
 592                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 593         }
 594         rcu_read_unlock();
 595
 596         if (atomic_read(&bat_priv->fragmentation) == 0)
 597                 goto out;
 598
 599         /* with fragmentation enabled the maximum size of internally generated
 600          * packets such as translation table exchanges or tvlv containers, etc
 601          * has to be calculated
 602          */
 603         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 604         min_mtu -= sizeof(struct batadv_frag_packet);
 605         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 606
 607 out:
 608         /* report to the other components the maximum amount of bytes that
 609          * batman-adv can send over the wire (without considering the payload
 610          * overhead). For example, this value is used by TT to compute the
 611          * maximum local table table size
 612          */
 613         atomic_set(&bat_priv->packet_size_max, min_mtu);
 614
 615         /* the real soft-interface MTU is computed by removing the payload
 616          * overhead from the maximum amount of bytes that was just computed.
 617          *
 618          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 619          */
 620         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 621 }
 622
 623 /**
 624  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 625  *  MTU appeared
 626  * @soft_iface: netdev struct of the soft interface
 627  */
 628 void batadv_update_min_mtu(struct net_device *soft_iface)
 629 {
 630         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 631
 632         /* Check if the local translate table should be cleaned up to match a
 633          * new (and smaller) MTU.
 634          */
 635         batadv_tt_local_resize_to_mtu(soft_iface);
 636 }
 637
 638 static void
 639 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 640 {
 641         struct batadv_priv *bat_priv;
 642         struct batadv_hard_iface *primary_if = NULL;
 643
 644         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 645                 goto out;
 646
 647         bat_priv = netdev_priv(hard_iface->soft_iface);
 648
 649         bat_priv->algo_ops->iface.update_mac(hard_iface);
 650         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 651
 652         /* the first active interface becomes our primary interface or
 653          * the next active interface after the old primary interface was removed
 654          */
 655         primary_if = batadv_primary_if_get_selected(bat_priv);
 656         if (!primary_if)
 657                 batadv_primary_if_select(bat_priv, hard_iface);
 658
 659         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 660                     hard_iface->net_dev->name);
 661
 662         batadv_update_min_mtu(hard_iface->soft_iface);
 663
 664         if (bat_priv->algo_ops->iface.activate)
 665                 bat_priv->algo_ops->iface.activate(hard_iface);
 666
 667 out:
 668         if (primary_if)
 669                 batadv_hardif_put(primary_if);
 670 }
 671
 672 static void
 673 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 674 {
 675         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 676             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 677                 return;
 678
 679         hard_iface->if_status = BATADV_IF_INACTIVE;
 680
 681         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 682                     hard_iface->net_dev->name);
 683
 684         batadv_update_min_mtu(hard_iface->soft_iface);
 685 }
 686
 687 /**
 688  * batadv_master_del_slave() - remove hard_iface from the current master iface
 689  * @slave: the interface enslaved in another master
 690  * @master: the master from which slave has to be removed
 691  *
 692  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 693  * is free'd and master can correctly change its internal state.
 694  *
 695  * Return: 0 on success, a negative value representing the error otherwise
 696  */
 697 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 698                                    struct net_device *master)
 699 {
 700         int ret;
 701
 702         if (!master)
 703                 return 0;
 704
 705         ret = -EBUSY;
 706         if (master->netdev_ops->ndo_del_slave)
 707                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 708
 709         return ret;
 710 }
 711
 712 /**
 713  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 714  * @hard_iface: hard interface to add to soft interface
 715  * @net: the applicable net namespace
 716  * @iface_name: name of the soft interface
 717  *
 718  * Return: 0 on success or negative error number in case of failure
 719  */
 720 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 721                                    struct net *net, const char *iface_name)
 722 {
 723         struct batadv_priv *bat_priv;
 724         struct net_device *soft_iface, *master;
 725         __be16 ethertype = htons(ETH_P_BATMAN);
 726         int max_header_len = batadv_max_header_len();
 727         int ret;
 728
 729         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 730                 goto out;
 731
 732         kref_get(&hard_iface->refcount);
 733
 734         soft_iface = dev_get_by_name(net, iface_name);
 735
 736         if (!soft_iface) {
 737                 soft_iface = batadv_softif_create(net, iface_name);
 738
 739                 if (!soft_iface) {
 740                         ret = -ENOMEM;
 741                         goto err;
 742                 }
 743
 744                 /* dev_get_by_name() increases the reference counter for us */
 745                 dev_hold(soft_iface);
 746         }
 747
 748         if (!batadv_softif_is_valid(soft_iface)) {
 749                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 750                        soft_iface->name);
 751                 ret = -EINVAL;
 752                 goto err_dev;
 753         }
 754
 755         /* check if the interface is enslaved in another virtual one and
 756          * in that case unlink it first
 757          */
 758         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 759         ret = batadv_master_del_slave(hard_iface, master);
 760         if (ret)
 761                 goto err_dev;
 762
 763         hard_iface->soft_iface = soft_iface;
 764         bat_priv = netdev_priv(hard_iface->soft_iface);
 765
 766         if (bat_priv->num_ifaces >= UINT_MAX) {
 767                 ret = -ENOSPC;
 768                 goto err_dev;
 769         }
 770
 771         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 772                                            soft_iface, NULL, NULL, NULL);
 773         if (ret)
 774                 goto err_dev;
 775
 776         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 777         if (ret < 0)
 778                 goto err_upper;
 779
 780         hard_iface->if_num = bat_priv->num_ifaces;
 781         bat_priv->num_ifaces++;
 782         hard_iface->if_status = BATADV_IF_INACTIVE;
 783         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 784         if (ret < 0) {
 785                 bat_priv->algo_ops->iface.disable(hard_iface);
 786                 bat_priv->num_ifaces--;
 787                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 788                 goto err_upper;
 789         }
 790
 791         kref_get(&hard_iface->refcount);
 792         hard_iface->batman_adv_ptype.type = ethertype;
 793         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 794         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 795         dev_add_pack(&hard_iface->batman_adv_ptype);
 796
 797         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 798                     hard_iface->net_dev->name);
 799
 800         if (atomic_read(&bat_priv->fragmentation) &&
 801             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 802                 batadv_info(hard_iface->soft_iface,
 803                             "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",
 804                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 805                             ETH_DATA_LEN + max_header_len);
 806
 807         if (!atomic_read(&bat_priv->fragmentation) &&
 808             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 809                 batadv_info(hard_iface->soft_iface,
 810                             "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",
 811                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 812                             ETH_DATA_LEN + max_header_len);
 813
 814         if (batadv_hardif_is_iface_up(hard_iface))
 815                 batadv_hardif_activate_interface(hard_iface);
 816         else
 817                 batadv_err(hard_iface->soft_iface,
 818                            "Not using interface %s (retrying later): interface not active\n",
 819                            hard_iface->net_dev->name);
 820
 821         batadv_hardif_recalc_extra_skbroom(soft_iface);
 822
 823 out:
 824         return 0;
 825
 826 err_upper:
 827         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 828 err_dev:
 829         hard_iface->soft_iface = NULL;
 830         dev_put(soft_iface);
 831 err:
 832         batadv_hardif_put(hard_iface);
 833         return ret;
 834 }
 835
 836 /**
 837  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 838  * @hard_iface: hard interface to be removed
 839  * @autodel: whether to delete soft interface when it doesn't contain any other
 840  *  slave interfaces
 841  */
 842 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 843                                      enum batadv_hard_if_cleanup autodel)
 844 {
 845         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 846         struct batadv_hard_iface *primary_if = NULL;
 847
 848         batadv_hardif_deactivate_interface(hard_iface);
 849
 850         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 851                 goto out;
 852
 853         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 854                     hard_iface->net_dev->name);
 855         dev_remove_pack(&hard_iface->batman_adv_ptype);
 856         batadv_hardif_put(hard_iface);
 857
 858         bat_priv->num_ifaces--;
 859         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 860
 861         primary_if = batadv_primary_if_get_selected(bat_priv);
 862         if (hard_iface == primary_if) {
 863                 struct batadv_hard_iface *new_if;
 864
 865                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 866                 batadv_primary_if_select(bat_priv, new_if);
 867
 868                 if (new_if)
 869                         batadv_hardif_put(new_if);
 870         }
 871
 872         bat_priv->algo_ops->iface.disable(hard_iface);
 873         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 874
 875         /* delete all references to this hard_iface */
 876         batadv_purge_orig_ref(bat_priv);
 877         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 878         dev_put(hard_iface->soft_iface);
 879
 880         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 881         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 882
 883         /* nobody uses this interface anymore */
 884         if (bat_priv->num_ifaces == 0) {
 885                 batadv_gw_check_client_stop(bat_priv);
 886
 887                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 888                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 889         }
 890
 891         hard_iface->soft_iface = NULL;
 892         batadv_hardif_put(hard_iface);
 893
 894 out:
 895         if (primary_if)
 896                 batadv_hardif_put(primary_if);
 897 }
 898
 899 static struct batadv_hard_iface *
 900 batadv_hardif_add_interface(struct net_device *net_dev)
 901 {
 902         struct batadv_hard_iface *hard_iface;
 903         int ret;
 904
 905         ASSERT_RTNL();
 906
 907         if (!batadv_is_valid_iface(net_dev))
 908                 goto out;
 909
 910         dev_hold(net_dev);
 911
 912         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 913         if (!hard_iface)
 914                 goto release_dev;
 915
 916         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 917         if (ret)
 918                 goto free_if;
 919
 920         hard_iface->if_num = 0;
 921         hard_iface->net_dev = net_dev;
 922         hard_iface->soft_iface = NULL;
 923         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 924
 925         ret = batadv_debugfs_add_hardif(hard_iface);
 926         if (ret)
 927                 goto free_sysfs;
 928
 929         INIT_LIST_HEAD(&hard_iface->list);
 930         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 931
 932         spin_lock_init(&hard_iface->neigh_list_lock);
 933         kref_init(&hard_iface->refcount);
 934
 935         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 936         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 937         if (batadv_is_wifi_hardif(hard_iface))
 938                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 939
 940         batadv_v_hardif_init(hard_iface);
 941
 942         batadv_check_known_mac_addr(hard_iface->net_dev);
 943         kref_get(&hard_iface->refcount);
 944         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 945
 946         return hard_iface;
 947
 948 free_sysfs:
 949         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 950 free_if:
 951         kfree(hard_iface);
 952 release_dev:
 953         dev_put(net_dev);
 954 out:
 955         return NULL;
 956 }
 957
 958 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 959 {
 960         ASSERT_RTNL();
 961
 962         /* first deactivate interface */
 963         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 964                 batadv_hardif_disable_interface(hard_iface,
 965                                                 BATADV_IF_CLEANUP_KEEP);
 966
 967         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 968                 return;
 969
 970         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 971         batadv_debugfs_del_hardif(hard_iface);
 972         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 973         batadv_hardif_put(hard_iface);
 974 }
 975
 976 /**
 977  * batadv_hardif_remove_interfaces() - Remove all hard interfaces
 978  */
 979 void batadv_hardif_remove_interfaces(void)
 980 {
 981         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 982
 983         rtnl_lock();
 984         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 985                                  &batadv_hardif_list, list) {
 986                 list_del_rcu(&hard_iface->list);
 987                 batadv_hardif_remove_interface(hard_iface);
 988         }
 989         rtnl_unlock();
 990 }
 991
 992 /**
 993  * batadv_hard_if_event_softif() - Handle events for soft interfaces
 994  * @event: NETDEV_* event to handle
 995  * @net_dev: net_device which generated an event
 996  *
 997  * Return: NOTIFY_* result
 998  */
 999 static int batadv_hard_if_event_softif(unsigned long event,
1000                                        struct net_device *net_dev)
1001 {
1002         struct batadv_priv *bat_priv;
1003
1004         switch (event) {
1005         case NETDEV_REGISTER:
1006                 batadv_sysfs_add_meshif(net_dev);
1007                 bat_priv = netdev_priv(net_dev);
1008                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1009                 break;
1010         case NETDEV_CHANGENAME:
1011                 batadv_debugfs_rename_meshif(net_dev);
1012                 break;
1013         }
1014
1015         return NOTIFY_DONE;
1016 }
1017
1018 static int batadv_hard_if_event(struct notifier_block *this,
1019                                 unsigned long event, void *ptr)
1020 {
1021         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1022         struct batadv_hard_iface *hard_iface;
1023         struct batadv_hard_iface *primary_if = NULL;
1024         struct batadv_priv *bat_priv;
1025
1026         if (batadv_softif_is_valid(net_dev))
1027                 return batadv_hard_if_event_softif(event, net_dev);
1028
1029         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1030         if (!hard_iface && (event == NETDEV_REGISTER ||
1031                             event == NETDEV_POST_TYPE_CHANGE))
1032                 hard_iface = batadv_hardif_add_interface(net_dev);
1033
1034         if (!hard_iface)
1035                 goto out;
1036
1037         switch (event) {
1038         case NETDEV_UP:
1039                 batadv_hardif_activate_interface(hard_iface);
1040                 break;
1041         case NETDEV_GOING_DOWN:
1042         case NETDEV_DOWN:
1043                 batadv_hardif_deactivate_interface(hard_iface);
1044                 break;
1045         case NETDEV_UNREGISTER:
1046         case NETDEV_PRE_TYPE_CHANGE:
1047                 list_del_rcu(&hard_iface->list);
1048
1049                 batadv_hardif_remove_interface(hard_iface);
1050                 break;
1051         case NETDEV_CHANGEMTU:
1052                 if (hard_iface->soft_iface)
1053                         batadv_update_min_mtu(hard_iface->soft_iface);
1054                 break;
1055         case NETDEV_CHANGEADDR:
1056                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1057                         goto hardif_put;
1058
1059                 batadv_check_known_mac_addr(hard_iface->net_dev);
1060
1061                 bat_priv = netdev_priv(hard_iface->soft_iface);
1062                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1063
1064                 primary_if = batadv_primary_if_get_selected(bat_priv);
1065                 if (!primary_if)
1066                         goto hardif_put;
1067
1068                 if (hard_iface == primary_if)
1069                         batadv_primary_if_update_addr(bat_priv, NULL);
1070                 break;
1071         case NETDEV_CHANGEUPPER:
1072                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1073                 if (batadv_is_wifi_hardif(hard_iface))
1074                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1075                 break;
1076         case NETDEV_CHANGENAME:
1077                 batadv_debugfs_rename_hardif(hard_iface);
1078                 break;
1079         default:
1080                 break;
1081         }
1082
1083 hardif_put:
1084         batadv_hardif_put(hard_iface);
1085 out:
1086         if (primary_if)
1087                 batadv_hardif_put(primary_if);
1088         return NOTIFY_DONE;
1089 }
1090
1091 struct notifier_block batadv_hard_if_notifier = {
1092         .notifier_call = batadv_hard_if_event,
1093 };