net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "hard-interface.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/errno.h>
  13 #include <linux/gfp.h>
  14 #include <linux/if.h>
  15 #include <linux/if_arp.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/kernel.h>
  18 #include <linux/kref.h>
  19 #include <linux/limits.h>
  20 #include <linux/list.h>
  21 #include <linux/mutex.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/printk.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rtnetlink.h>
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <net/net_namespace.h>
  29 #include <net/rtnetlink.h>
  30 #include <uapi/linux/batadv_packet.h>
  31
  32 #include "bat_v.h"
  33 #include "bridge_loop_avoidance.h"
  34 #include "debugfs.h"
  35 #include "distributed-arp-table.h"
  36 #include "gateway_client.h"
  37 #include "log.h"
  38 #include "originator.h"
  39 #include "send.h"
  40 #include "soft-interface.h"
  41 #include "sysfs.h"
  42 #include "translation-table.h"
  43
  44 /**
  45  * batadv_hardif_release() - release hard interface from lists and queue for
  46  *  free after rcu grace period
  47  * @ref: kref pointer of the hard interface
  48  */
  49 void batadv_hardif_release(struct kref *ref)
  50 {
  51         struct batadv_hard_iface *hard_iface;
  52
  53         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  54         dev_put(hard_iface->net_dev);
  55
  56         kfree_rcu(hard_iface, rcu);
  57 }
  58
  59 /**
  60  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  61  * @net_dev: net_device to search for
  62  *
  63  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  64  */
  65 struct batadv_hard_iface *
  66 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  67 {
  68         struct batadv_hard_iface *hard_iface;
  69
  70         rcu_read_lock();
  71         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  72                 if (hard_iface->net_dev == net_dev &&
  73                     kref_get_unless_zero(&hard_iface->refcount))
  74                         goto out;
  75         }
  76
  77         hard_iface = NULL;
  78
  79 out:
  80         rcu_read_unlock();
  81         return hard_iface;
  82 }
  83
  84 /**
  85  * batadv_getlink_net() - return link net namespace (of use fallback)
  86  * @netdev: net_device to check
  87  * @fallback_net: return in case get_link_net is not available for @netdev
  88  *
  89  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
  90  */
  91 static struct net *batadv_getlink_net(const struct net_device *netdev,
  92                                       struct net *fallback_net)
  93 {
  94         if (!netdev->rtnl_link_ops)
  95                 return fallback_net;
  96
  97         if (!netdev->rtnl_link_ops->get_link_net)
  98                 return fallback_net;
  99
 100         return netdev->rtnl_link_ops->get_link_net(netdev);
 101 }
 102
 103 /**
 104  * batadv_mutual_parents() - check if two devices are each others parent
 105  * @dev1: 1st net dev
 106  * @net1: 1st devices netns
 107  * @dev2: 2nd net dev
 108  * @net2: 2nd devices netns
 109  *
 110  * veth devices come in pairs and each is the parent of the other!
 111  *
 112  * Return: true if the devices are each others parent, otherwise false
 113  */
 114 static bool batadv_mutual_parents(const struct net_device *dev1,
 115                                   struct net *net1,
 116                                   const struct net_device *dev2,
 117                                   struct net *net2)
 118 {
 119         int dev1_parent_iflink = dev_get_iflink(dev1);
 120         int dev2_parent_iflink = dev_get_iflink(dev2);
 121         const struct net *dev1_parent_net;
 122         const struct net *dev2_parent_net;
 123
 124         dev1_parent_net = batadv_getlink_net(dev1, net1);
 125         dev2_parent_net = batadv_getlink_net(dev2, net2);
 126
 127         if (!dev1_parent_iflink || !dev2_parent_iflink)
 128                 return false;
 129
 130         return (dev1_parent_iflink == dev2->ifindex) &&
 131                (dev2_parent_iflink == dev1->ifindex) &&
 132                net_eq(dev1_parent_net, net2) &&
 133                net_eq(dev2_parent_net, net1);
 134 }
 135
 136 /**
 137  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 138  * @net_dev: the device to check
 139  *
 140  * If the user creates any virtual device on top of a batman-adv interface, it
 141  * is important to prevent this new interface from being used to create a new
 142  * mesh network (this behaviour would lead to a batman-over-batman
 143  * configuration). This function recursively checks all the fathers of the
 144  * device passed as argument looking for a batman-adv soft interface.
 145  *
 146  * Return: true if the device is descendant of a batman-adv mesh interface (or
 147  * if it is a batman-adv interface itself), false otherwise
 148  */
 149 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 150 {
 151         struct net *net = dev_net(net_dev);
 152         struct net_device *parent_dev;
 153         struct net *parent_net;
 154         int iflink;
 155         bool ret;
 156
 157         /* check if this is a batman-adv mesh interface */
 158         if (batadv_softif_is_valid(net_dev))
 159                 return true;
 160
 161         iflink = dev_get_iflink(net_dev);
 162         if (iflink == 0)
 163                 return false;
 164
 165         parent_net = batadv_getlink_net(net_dev, net);
 166
 167         /* iflink to itself, most likely physical device */
 168         if (net == parent_net && iflink == net_dev->ifindex)
 169                 return false;
 170
 171         /* recurse over the parent device */
 172         parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
 173         /* if we got a NULL parent_dev there is something broken.. */
 174         if (!parent_dev) {
 175                 pr_err("Cannot find parent device\n");
 176                 return false;
 177         }
 178
 179         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 180                 return false;
 181
 182         ret = batadv_is_on_batman_iface(parent_dev);
 183
 184         return ret;
 185 }
 186
 187 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 188 {
 189         if (net_dev->flags & IFF_LOOPBACK)
 190                 return false;
 191
 192         if (net_dev->type != ARPHRD_ETHER)
 193                 return false;
 194
 195         if (net_dev->addr_len != ETH_ALEN)
 196                 return false;
 197
 198         /* no batman over batman */
 199         if (batadv_is_on_batman_iface(net_dev))
 200                 return false;
 201
 202         return true;
 203 }
 204
 205 /**
 206  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 207  *  interface on top of another 'real' interface
 208  * @netdev: the device to check
 209  *
 210  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 211  * instead of this.
 212  *
 213  * Return: the 'real' net device or the original net device and NULL in case
 214  *  of an error.
 215  */
 216 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 217 {
 218         struct batadv_hard_iface *hard_iface = NULL;
 219         struct net_device *real_netdev = NULL;
 220         struct net *real_net;
 221         struct net *net;
 222         int iflink;
 223
 224         ASSERT_RTNL();
 225
 226         if (!netdev)
 227                 return NULL;
 228
 229         iflink = dev_get_iflink(netdev);
 230         if (iflink == 0) {
 231                 dev_hold(netdev);
 232                 return netdev;
 233         }
 234
 235         hard_iface = batadv_hardif_get_by_netdev(netdev);
 236         if (!hard_iface || !hard_iface->soft_iface)
 237                 goto out;
 238
 239         net = dev_net(hard_iface->soft_iface);
 240         real_net = batadv_getlink_net(netdev, net);
 241
 242         /* iflink to itself, most likely physical device */
 243         if (net == real_net && netdev->ifindex == iflink) {
 244                 real_netdev = netdev;
 245                 dev_hold(real_netdev);
 246                 goto out;
 247         }
 248
 249         real_netdev = dev_get_by_index(real_net, iflink);
 250
 251 out:
 252         if (hard_iface)
 253                 batadv_hardif_put(hard_iface);
 254         return real_netdev;
 255 }
 256
 257 /**
 258  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 259  *  interface on top of another 'real' interface
 260  * @net_device: the device to check
 261  *
 262  * Return: the 'real' net device or the original net device and NULL in case
 263  *  of an error.
 264  */
 265 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 266 {
 267         struct net_device *real_netdev;
 268
 269         rtnl_lock();
 270         real_netdev = batadv_get_real_netdevice(net_device);
 271         rtnl_unlock();
 272
 273         return real_netdev;
 274 }
 275
 276 /**
 277  * batadv_is_wext_netdev() - check if the given net_device struct is a
 278  *  wext wifi interface
 279  * @net_device: the device to check
 280  *
 281  * Return: true if the net device is a wext wireless device, false
 282  *  otherwise.
 283  */
 284 static bool batadv_is_wext_netdev(struct net_device *net_device)
 285 {
 286         if (!net_device)
 287                 return false;
 288
 289 #ifdef CONFIG_WIRELESS_EXT
 290         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 291          * check for wireless_handlers != NULL
 292          */
 293         if (net_device->wireless_handlers)
 294                 return true;
 295 #endif
 296
 297         return false;
 298 }
 299
 300 /**
 301  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 302  *  cfg80211 wifi interface
 303  * @net_device: the device to check
 304  *
 305  * Return: true if the net device is a cfg80211 wireless device, false
 306  *  otherwise.
 307  */
 308 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 309 {
 310         if (!net_device)
 311                 return false;
 312
 313         /* cfg80211 drivers have to set ieee80211_ptr */
 314         if (net_device->ieee80211_ptr)
 315                 return true;
 316
 317         return false;
 318 }
 319
 320 /**
 321  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 322  * @net_device: the device to check
 323  *
 324  * Return: batadv_hard_iface_wifi_flags flags of the device
 325  */
 326 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 327 {
 328         u32 wifi_flags = 0;
 329         struct net_device *real_netdev;
 330
 331         if (batadv_is_wext_netdev(net_device))
 332                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 333
 334         if (batadv_is_cfg80211_netdev(net_device))
 335                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 336
 337         real_netdev = batadv_get_real_netdevice(net_device);
 338         if (!real_netdev)
 339                 return wifi_flags;
 340
 341         if (real_netdev == net_device)
 342                 goto out;
 343
 344         if (batadv_is_wext_netdev(real_netdev))
 345                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 346
 347         if (batadv_is_cfg80211_netdev(real_netdev))
 348                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 349
 350 out:
 351         dev_put(real_netdev);
 352         return wifi_flags;
 353 }
 354
 355 /**
 356  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 357  *  interface
 358  * @hard_iface: the device to check
 359  *
 360  * Return: true if the net device is a cfg80211 wireless device, false
 361  *  otherwise.
 362  */
 363 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 364 {
 365         u32 allowed_flags = 0;
 366
 367         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 368         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 369
 370         return !!(hard_iface->wifi_flags & allowed_flags);
 371 }
 372
 373 /**
 374  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 375  * @hard_iface: the device to check
 376  *
 377  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 378  */
 379 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 380 {
 381         if (!hard_iface)
 382                 return false;
 383
 384         return hard_iface->wifi_flags != 0;
 385 }
 386
 387 /**
 388  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 389  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 390  * @orig_addr: the originator of this packet
 391  * @orig_neigh: originator address of the forwarder we just got the packet from
 392  *  (NULL if we originated)
 393  *
 394  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 395  *
 396  * Return:
 397  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 398  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 399  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 400  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 401  */
 402 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 403                                u8 *orig_addr, u8 *orig_neigh)
 404 {
 405         struct batadv_hardif_neigh_node *hardif_neigh;
 406         struct hlist_node *first;
 407         int ret = BATADV_HARDIF_BCAST_OK;
 408
 409         rcu_read_lock();
 410
 411         /* 0 neighbors -> no (re)broadcast */
 412         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 413         if (!first) {
 414                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 415                 goto out;
 416         }
 417
 418         /* >1 neighbors -> (re)brodcast */
 419         if (rcu_dereference(hlist_next_rcu(first)))
 420                 goto out;
 421
 422         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 423                                    list);
 424
 425         /* 1 neighbor, is the originator -> no rebroadcast */
 426         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 427                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 428         /* 1 neighbor, is the one we received from -> no rebroadcast */
 429         } else if (orig_neigh &&
 430                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 431                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 432         }
 433
 434 out:
 435         rcu_read_unlock();
 436         return ret;
 437 }
 438
 439 static struct batadv_hard_iface *
 440 batadv_hardif_get_active(const struct net_device *soft_iface)
 441 {
 442         struct batadv_hard_iface *hard_iface;
 443
 444         rcu_read_lock();
 445         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 446                 if (hard_iface->soft_iface != soft_iface)
 447                         continue;
 448
 449                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 450                     kref_get_unless_zero(&hard_iface->refcount))
 451                         goto out;
 452         }
 453
 454         hard_iface = NULL;
 455
 456 out:
 457         rcu_read_unlock();
 458         return hard_iface;
 459 }
 460
 461 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 462                                           struct batadv_hard_iface *oldif)
 463 {
 464         struct batadv_hard_iface *primary_if;
 465
 466         primary_if = batadv_primary_if_get_selected(bat_priv);
 467         if (!primary_if)
 468                 goto out;
 469
 470         batadv_dat_init_own_addr(bat_priv, primary_if);
 471         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 472 out:
 473         if (primary_if)
 474                 batadv_hardif_put(primary_if);
 475 }
 476
 477 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 478                                      struct batadv_hard_iface *new_hard_iface)
 479 {
 480         struct batadv_hard_iface *curr_hard_iface;
 481
 482         ASSERT_RTNL();
 483
 484         if (new_hard_iface)
 485                 kref_get(&new_hard_iface->refcount);
 486
 487         curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
 488                                               new_hard_iface, 1);
 489
 490         if (!new_hard_iface)
 491                 goto out;
 492
 493         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 494         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 495
 496 out:
 497         if (curr_hard_iface)
 498                 batadv_hardif_put(curr_hard_iface);
 499 }
 500
 501 static bool
 502 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 503 {
 504         if (hard_iface->net_dev->flags & IFF_UP)
 505                 return true;
 506
 507         return false;
 508 }
 509
 510 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 511 {
 512         const struct batadv_hard_iface *hard_iface;
 513
 514         rcu_read_lock();
 515         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 516                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 517                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 518                         continue;
 519
 520                 if (hard_iface->net_dev == net_dev)
 521                         continue;
 522
 523                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 524                                         net_dev->dev_addr))
 525                         continue;
 526
 527                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 528                         net_dev->dev_addr, hard_iface->net_dev->name);
 529                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 530         }
 531         rcu_read_unlock();
 532 }
 533
 534 /**
 535  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 536  * @soft_iface: netdev struct of the mesh interface
 537  */
 538 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 539 {
 540         const struct batadv_hard_iface *hard_iface;
 541         unsigned short lower_header_len = ETH_HLEN;
 542         unsigned short lower_headroom = 0;
 543         unsigned short lower_tailroom = 0;
 544         unsigned short needed_headroom;
 545
 546         rcu_read_lock();
 547         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 548                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 549                         continue;
 550
 551                 if (hard_iface->soft_iface != soft_iface)
 552                         continue;
 553
 554                 lower_header_len = max_t(unsigned short, lower_header_len,
 555                                          hard_iface->net_dev->hard_header_len);
 556
 557                 lower_headroom = max_t(unsigned short, lower_headroom,
 558                                        hard_iface->net_dev->needed_headroom);
 559
 560                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 561                                        hard_iface->net_dev->needed_tailroom);
 562         }
 563         rcu_read_unlock();
 564
 565         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 566         needed_headroom += batadv_max_header_len();
 567
 568         /* fragmentation headers don't strip the unicast/... header */
 569         needed_headroom += sizeof(struct batadv_frag_packet);
 570
 571         soft_iface->needed_headroom = needed_headroom;
 572         soft_iface->needed_tailroom = lower_tailroom;
 573 }
 574
 575 /**
 576  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 577  * @soft_iface: netdev struct of the soft interface
 578  *
 579  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 580  *  slave interfaces)
 581  */
 582 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 583 {
 584         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 585         const struct batadv_hard_iface *hard_iface;
 586         int min_mtu = INT_MAX;
 587
 588         rcu_read_lock();
 589         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 590                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 591                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 592                         continue;
 593
 594                 if (hard_iface->soft_iface != soft_iface)
 595                         continue;
 596
 597                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 598         }
 599         rcu_read_unlock();
 600
 601         if (atomic_read(&bat_priv->fragmentation) == 0)
 602                 goto out;
 603
 604         /* with fragmentation enabled the maximum size of internally generated
 605          * packets such as translation table exchanges or tvlv containers, etc
 606          * has to be calculated
 607          */
 608         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 609         min_mtu -= sizeof(struct batadv_frag_packet);
 610         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 611
 612 out:
 613         /* report to the other components the maximum amount of bytes that
 614          * batman-adv can send over the wire (without considering the payload
 615          * overhead). For example, this value is used by TT to compute the
 616          * maximum local table size
 617          */
 618         atomic_set(&bat_priv->packet_size_max, min_mtu);
 619
 620         /* the real soft-interface MTU is computed by removing the payload
 621          * overhead from the maximum amount of bytes that was just computed.
 622          *
 623          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 624          */
 625         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 626 }
 627
 628 /**
 629  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 630  *  MTU appeared
 631  * @soft_iface: netdev struct of the soft interface
 632  */
 633 void batadv_update_min_mtu(struct net_device *soft_iface)
 634 {
 635         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 636         int limit_mtu;
 637         int mtu;
 638
 639         mtu = batadv_hardif_min_mtu(soft_iface);
 640
 641         if (bat_priv->mtu_set_by_user)
 642                 limit_mtu = bat_priv->mtu_set_by_user;
 643         else
 644                 limit_mtu = ETH_DATA_LEN;
 645
 646         mtu = min(mtu, limit_mtu);
 647         dev_set_mtu(soft_iface, mtu);
 648
 649         /* Check if the local translate table should be cleaned up to match a
 650          * new (and smaller) MTU.
 651          */
 652         batadv_tt_local_resize_to_mtu(soft_iface);
 653 }
 654
 655 static void
 656 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 657 {
 658         struct batadv_priv *bat_priv;
 659         struct batadv_hard_iface *primary_if = NULL;
 660
 661         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 662                 goto out;
 663
 664         bat_priv = netdev_priv(hard_iface->soft_iface);
 665
 666         bat_priv->algo_ops->iface.update_mac(hard_iface);
 667         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 668
 669         /* the first active interface becomes our primary interface or
 670          * the next active interface after the old primary interface was removed
 671          */
 672         primary_if = batadv_primary_if_get_selected(bat_priv);
 673         if (!primary_if)
 674                 batadv_primary_if_select(bat_priv, hard_iface);
 675
 676         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 677                     hard_iface->net_dev->name);
 678
 679         batadv_update_min_mtu(hard_iface->soft_iface);
 680
 681         if (bat_priv->algo_ops->iface.activate)
 682                 bat_priv->algo_ops->iface.activate(hard_iface);
 683
 684 out:
 685         if (primary_if)
 686                 batadv_hardif_put(primary_if);
 687 }
 688
 689 static void
 690 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 691 {
 692         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 693             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 694                 return;
 695
 696         hard_iface->if_status = BATADV_IF_INACTIVE;
 697
 698         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 699                     hard_iface->net_dev->name);
 700
 701         batadv_update_min_mtu(hard_iface->soft_iface);
 702 }
 703
 704 /**
 705  * batadv_master_del_slave() - remove hard_iface from the current master iface
 706  * @slave: the interface enslaved in another master
 707  * @master: the master from which slave has to be removed
 708  *
 709  * Invoke ndo_del_slave on master passing slave as argument. In this way the
 710  * slave is free'd and the master can correctly change its internal state.
 711  *
 712  * Return: 0 on success, a negative value representing the error otherwise
 713  */
 714 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 715                                    struct net_device *master)
 716 {
 717         int ret;
 718
 719         if (!master)
 720                 return 0;
 721
 722         ret = -EBUSY;
 723         if (master->netdev_ops->ndo_del_slave)
 724                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 725
 726         return ret;
 727 }
 728
 729 /**
 730  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 731  * @hard_iface: hard interface to add to soft interface
 732  * @net: the applicable net namespace
 733  * @iface_name: name of the soft interface
 734  *
 735  * Return: 0 on success or negative error number in case of failure
 736  */
 737 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 738                                    struct net *net, const char *iface_name)
 739 {
 740         struct batadv_priv *bat_priv;
 741         struct net_device *soft_iface, *master;
 742         __be16 ethertype = htons(ETH_P_BATMAN);
 743         int max_header_len = batadv_max_header_len();
 744         int ret;
 745
 746         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 747                 goto out;
 748
 749         kref_get(&hard_iface->refcount);
 750
 751         soft_iface = dev_get_by_name(net, iface_name);
 752
 753         if (!soft_iface) {
 754                 soft_iface = batadv_softif_create(net, iface_name);
 755
 756                 if (!soft_iface) {
 757                         ret = -ENOMEM;
 758                         goto err;
 759                 }
 760
 761                 /* dev_get_by_name() increases the reference counter for us */
 762                 dev_hold(soft_iface);
 763         }
 764
 765         if (!batadv_softif_is_valid(soft_iface)) {
 766                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 767                        soft_iface->name);
 768                 ret = -EINVAL;
 769                 goto err_dev;
 770         }
 771
 772         /* check if the interface is enslaved in another virtual one and
 773          * in that case unlink it first
 774          */
 775         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 776         ret = batadv_master_del_slave(hard_iface, master);
 777         if (ret)
 778                 goto err_dev;
 779
 780         hard_iface->soft_iface = soft_iface;
 781         bat_priv = netdev_priv(hard_iface->soft_iface);
 782
 783         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 784                                            soft_iface, NULL, NULL, NULL);
 785         if (ret)
 786                 goto err_dev;
 787
 788         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 789         if (ret < 0)
 790                 goto err_upper;
 791
 792         hard_iface->if_status = BATADV_IF_INACTIVE;
 793
 794         kref_get(&hard_iface->refcount);
 795         hard_iface->batman_adv_ptype.type = ethertype;
 796         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 797         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 798         dev_add_pack(&hard_iface->batman_adv_ptype);
 799
 800         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 801                     hard_iface->net_dev->name);
 802
 803         if (atomic_read(&bat_priv->fragmentation) &&
 804             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 805                 batadv_info(hard_iface->soft_iface,
 806                             "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",
 807                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 808                             ETH_DATA_LEN + max_header_len);
 809
 810         if (!atomic_read(&bat_priv->fragmentation) &&
 811             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 812                 batadv_info(hard_iface->soft_iface,
 813                             "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",
 814                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 815                             ETH_DATA_LEN + max_header_len);
 816
 817         if (batadv_hardif_is_iface_up(hard_iface))
 818                 batadv_hardif_activate_interface(hard_iface);
 819         else
 820                 batadv_err(hard_iface->soft_iface,
 821                            "Not using interface %s (retrying later): interface not active\n",
 822                            hard_iface->net_dev->name);
 823
 824         batadv_hardif_recalc_extra_skbroom(soft_iface);
 825
 826         if (bat_priv->algo_ops->iface.enabled)
 827                 bat_priv->algo_ops->iface.enabled(hard_iface);
 828
 829 out:
 830         return 0;
 831
 832 err_upper:
 833         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 834 err_dev:
 835         hard_iface->soft_iface = NULL;
 836         dev_put(soft_iface);
 837 err:
 838         batadv_hardif_put(hard_iface);
 839         return ret;
 840 }
 841
 842 /**
 843  * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
 844  * @soft_iface: soft interface to check
 845  *
 846  * This function is only using RCU for locking - the result can therefore be
 847  * off when another function is modifying the list at the same time. The
 848  * caller can use the rtnl_lock to make sure that the count is accurate.
 849  *
 850  * Return: number of connected/enslaved hard interfaces
 851  */
 852 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
 853 {
 854         struct batadv_hard_iface *hard_iface;
 855         size_t count = 0;
 856
 857         rcu_read_lock();
 858         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 859                 if (hard_iface->soft_iface != soft_iface)
 860                         continue;
 861
 862                 count++;
 863         }
 864         rcu_read_unlock();
 865
 866         return count;
 867 }
 868
 869 /**
 870  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 871  * @hard_iface: hard interface to be removed
 872  * @autodel: whether to delete soft interface when it doesn't contain any other
 873  *  slave interfaces
 874  */
 875 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 876                                      enum batadv_hard_if_cleanup autodel)
 877 {
 878         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 879         struct batadv_hard_iface *primary_if = NULL;
 880
 881         batadv_hardif_deactivate_interface(hard_iface);
 882
 883         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 884                 goto out;
 885
 886         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 887                     hard_iface->net_dev->name);
 888         dev_remove_pack(&hard_iface->batman_adv_ptype);
 889         batadv_hardif_put(hard_iface);
 890
 891         primary_if = batadv_primary_if_get_selected(bat_priv);
 892         if (hard_iface == primary_if) {
 893                 struct batadv_hard_iface *new_if;
 894
 895                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 896                 batadv_primary_if_select(bat_priv, new_if);
 897
 898                 if (new_if)
 899                         batadv_hardif_put(new_if);
 900         }
 901
 902         bat_priv->algo_ops->iface.disable(hard_iface);
 903         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 904
 905         /* delete all references to this hard_iface */
 906         batadv_purge_orig_ref(bat_priv);
 907         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 908         dev_put(hard_iface->soft_iface);
 909
 910         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 911         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 912
 913         /* nobody uses this interface anymore */
 914         if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 915                 batadv_gw_check_client_stop(bat_priv);
 916
 917                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 918                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 919         }
 920
 921         hard_iface->soft_iface = NULL;
 922         batadv_hardif_put(hard_iface);
 923
 924 out:
 925         if (primary_if)
 926                 batadv_hardif_put(primary_if);
 927 }
 928
 929 static struct batadv_hard_iface *
 930 batadv_hardif_add_interface(struct net_device *net_dev)
 931 {
 932         struct batadv_hard_iface *hard_iface;
 933         int ret;
 934
 935         ASSERT_RTNL();
 936
 937         if (!batadv_is_valid_iface(net_dev))
 938                 goto out;
 939
 940         dev_hold(net_dev);
 941
 942         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 943         if (!hard_iface)
 944                 goto release_dev;
 945
 946         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 947         if (ret)
 948                 goto free_if;
 949
 950         hard_iface->net_dev = net_dev;
 951         hard_iface->soft_iface = NULL;
 952         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 953
 954         batadv_debugfs_add_hardif(hard_iface);
 955
 956         INIT_LIST_HEAD(&hard_iface->list);
 957         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 958
 959         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 960         spin_lock_init(&hard_iface->neigh_list_lock);
 961         kref_init(&hard_iface->refcount);
 962
 963         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 964         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 965         if (batadv_is_wifi_hardif(hard_iface))
 966                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 967
 968         atomic_set(&hard_iface->hop_penalty, 0);
 969
 970         batadv_v_hardif_init(hard_iface);
 971
 972         batadv_check_known_mac_addr(hard_iface->net_dev);
 973         kref_get(&hard_iface->refcount);
 974         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 975         batadv_hardif_generation++;
 976
 977         return hard_iface;
 978
 979 free_if:
 980         kfree(hard_iface);
 981 release_dev:
 982         dev_put(net_dev);
 983 out:
 984         return NULL;
 985 }
 986
 987 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 988 {
 989         ASSERT_RTNL();
 990
 991         /* first deactivate interface */
 992         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 993                 batadv_hardif_disable_interface(hard_iface,
 994                                                 BATADV_IF_CLEANUP_KEEP);
 995
 996         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 997                 return;
 998
 999         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
1000         batadv_debugfs_del_hardif(hard_iface);
1001         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
1002         batadv_hardif_put(hard_iface);
1003 }
1004
1005 /**
1006  * batadv_hard_if_event_softif() - Handle events for soft interfaces
1007  * @event: NETDEV_* event to handle
1008  * @net_dev: net_device which generated an event
1009  *
1010  * Return: NOTIFY_* result
1011  */
1012 static int batadv_hard_if_event_softif(unsigned long event,
1013                                        struct net_device *net_dev)
1014 {
1015         struct batadv_priv *bat_priv;
1016
1017         switch (event) {
1018         case NETDEV_REGISTER:
1019                 batadv_sysfs_add_meshif(net_dev);
1020                 bat_priv = netdev_priv(net_dev);
1021                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1022                 break;
1023         case NETDEV_CHANGENAME:
1024                 batadv_debugfs_rename_meshif(net_dev);
1025                 break;
1026         }
1027
1028         return NOTIFY_DONE;
1029 }
1030
1031 static int batadv_hard_if_event(struct notifier_block *this,
1032                                 unsigned long event, void *ptr)
1033 {
1034         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1035         struct batadv_hard_iface *hard_iface;
1036         struct batadv_hard_iface *primary_if = NULL;
1037         struct batadv_priv *bat_priv;
1038
1039         if (batadv_softif_is_valid(net_dev))
1040                 return batadv_hard_if_event_softif(event, net_dev);
1041
1042         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1043         if (!hard_iface && (event == NETDEV_REGISTER ||
1044                             event == NETDEV_POST_TYPE_CHANGE))
1045                 hard_iface = batadv_hardif_add_interface(net_dev);
1046
1047         if (!hard_iface)
1048                 goto out;
1049
1050         switch (event) {
1051         case NETDEV_UP:
1052                 batadv_hardif_activate_interface(hard_iface);
1053                 break;
1054         case NETDEV_GOING_DOWN:
1055         case NETDEV_DOWN:
1056                 batadv_hardif_deactivate_interface(hard_iface);
1057                 break;
1058         case NETDEV_UNREGISTER:
1059         case NETDEV_PRE_TYPE_CHANGE:
1060                 list_del_rcu(&hard_iface->list);
1061                 batadv_hardif_generation++;
1062
1063                 batadv_hardif_remove_interface(hard_iface);
1064                 break;
1065         case NETDEV_CHANGEMTU:
1066                 if (hard_iface->soft_iface)
1067                         batadv_update_min_mtu(hard_iface->soft_iface);
1068                 break;
1069         case NETDEV_CHANGEADDR:
1070                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1071                         goto hardif_put;
1072
1073                 batadv_check_known_mac_addr(hard_iface->net_dev);
1074
1075                 bat_priv = netdev_priv(hard_iface->soft_iface);
1076                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1077
1078                 primary_if = batadv_primary_if_get_selected(bat_priv);
1079                 if (!primary_if)
1080                         goto hardif_put;
1081
1082                 if (hard_iface == primary_if)
1083                         batadv_primary_if_update_addr(bat_priv, NULL);
1084                 break;
1085         case NETDEV_CHANGEUPPER:
1086                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1087                 if (batadv_is_wifi_hardif(hard_iface))
1088                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1089                 break;
1090         case NETDEV_CHANGENAME:
1091                 batadv_debugfs_rename_hardif(hard_iface);
1092                 break;
1093         default:
1094                 break;
1095         }
1096
1097 hardif_put:
1098         batadv_hardif_put(hard_iface);
1099 out:
1100         if (primary_if)
1101                 batadv_hardif_put(primary_if);
1102         return NOTIFY_DONE;
1103 }
1104
1105 struct notifier_block batadv_hard_if_notifier = {
1106         .notifier_call = batadv_hard_if_event,
1107 };