net/batman-adv/hard-interface.c

   1 /* Copyright (C) 2007-2016  B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "hard-interface.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/bug.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/fs.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/if_ether.h>
  28 #include <linux/if.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 <linux/workqueue.h>
  39 #include <net/net_namespace.h>
  40
  41 #include "bridge_loop_avoidance.h"
  42 #include "debugfs.h"
  43 #include "distributed-arp-table.h"
  44 #include "gateway_client.h"
  45 #include "originator.h"
  46 #include "packet.h"
  47 #include "send.h"
  48 #include "soft-interface.h"
  49 #include "sysfs.h"
  50 #include "translation-table.h"
  51
  52 /**
  53  * batadv_hardif_release - release hard interface from lists and queue for
  54  *  free after rcu grace period
  55  * @ref: kref pointer of the hard interface
  56  */
  57 void batadv_hardif_release(struct kref *ref)
  58 {
  59         struct batadv_hard_iface *hard_iface;
  60
  61         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  62         dev_put(hard_iface->net_dev);
  63
  64         kfree_rcu(hard_iface, rcu);
  65 }
  66
  67 struct batadv_hard_iface *
  68 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  69 {
  70         struct batadv_hard_iface *hard_iface;
  71
  72         rcu_read_lock();
  73         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  74                 if (hard_iface->net_dev == net_dev &&
  75                     kref_get_unless_zero(&hard_iface->refcount))
  76                         goto out;
  77         }
  78
  79         hard_iface = NULL;
  80
  81 out:
  82         rcu_read_unlock();
  83         return hard_iface;
  84 }
  85
  86 /**
  87  * batadv_mutual_parents - check if two devices are each others parent
  88  * @dev1: 1st net_device
  89  * @dev2: 2nd net_device
  90  *
  91  * veth devices come in pairs and each is the parent of the other!
  92  *
  93  * Return: true if the devices are each others parent, otherwise false
  94  */
  95 static bool batadv_mutual_parents(const struct net_device *dev1,
  96                                   const struct net_device *dev2)
  97 {
  98         int dev1_parent_iflink = dev_get_iflink(dev1);
  99         int dev2_parent_iflink = dev_get_iflink(dev2);
 100
 101         if (!dev1_parent_iflink || !dev2_parent_iflink)
 102                 return false;
 103
 104         return (dev1_parent_iflink == dev2->ifindex) &&
 105                (dev2_parent_iflink == dev1->ifindex);
 106 }
 107
 108 /**
 109  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
 110  * @net_dev: the device to check
 111  *
 112  * If the user creates any virtual device on top of a batman-adv interface, it
 113  * is important to prevent this new interface to be used to create a new mesh
 114  * network (this behaviour would lead to a batman-over-batman configuration).
 115  * This function recursively checks all the fathers of the device passed as
 116  * argument looking for a batman-adv soft interface.
 117  *
 118  * Return: true if the device is descendant of a batman-adv mesh interface (or
 119  * if it is a batman-adv interface itself), false otherwise
 120  */
 121 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 122 {
 123         struct net_device *parent_dev;
 124         bool ret;
 125
 126         /* check if this is a batman-adv mesh interface */
 127         if (batadv_softif_is_valid(net_dev))
 128                 return true;
 129
 130         /* no more parents..stop recursion */
 131         if (dev_get_iflink(net_dev) == 0 ||
 132             dev_get_iflink(net_dev) == net_dev->ifindex)
 133                 return false;
 134
 135         /* recurse over the parent device */
 136         parent_dev = __dev_get_by_index(&init_net, dev_get_iflink(net_dev));
 137         /* if we got a NULL parent_dev there is something broken.. */
 138         if (WARN(!parent_dev, "Cannot find parent device"))
 139                 return false;
 140
 141         if (batadv_mutual_parents(net_dev, parent_dev))
 142                 return false;
 143
 144         ret = batadv_is_on_batman_iface(parent_dev);
 145
 146         return ret;
 147 }
 148
 149 static int batadv_is_valid_iface(const struct net_device *net_dev)
 150 {
 151         if (net_dev->flags & IFF_LOOPBACK)
 152                 return 0;
 153
 154         if (net_dev->type != ARPHRD_ETHER)
 155                 return 0;
 156
 157         if (net_dev->addr_len != ETH_ALEN)
 158                 return 0;
 159
 160         /* no batman over batman */
 161         if (batadv_is_on_batman_iface(net_dev))
 162                 return 0;
 163
 164         return 1;
 165 }
 166
 167 /**
 168  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
 169  *  interface
 170  * @net_device: the device to check
 171  *
 172  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 173  */
 174 bool batadv_is_wifi_netdev(struct net_device *net_device)
 175 {
 176         if (!net_device)
 177                 return false;
 178
 179 #ifdef CONFIG_WIRELESS_EXT
 180         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 181          * check for wireless_handlers != NULL
 182          */
 183         if (net_device->wireless_handlers)
 184                 return true;
 185 #endif
 186
 187         /* cfg80211 drivers have to set ieee80211_ptr */
 188         if (net_device->ieee80211_ptr)
 189                 return true;
 190
 191         return false;
 192 }
 193
 194 static struct batadv_hard_iface *
 195 batadv_hardif_get_active(const struct net_device *soft_iface)
 196 {
 197         struct batadv_hard_iface *hard_iface;
 198
 199         rcu_read_lock();
 200         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 201                 if (hard_iface->soft_iface != soft_iface)
 202                         continue;
 203
 204                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 205                     kref_get_unless_zero(&hard_iface->refcount))
 206                         goto out;
 207         }
 208
 209         hard_iface = NULL;
 210
 211 out:
 212         rcu_read_unlock();
 213         return hard_iface;
 214 }
 215
 216 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 217                                           struct batadv_hard_iface *oldif)
 218 {
 219         struct batadv_hard_iface *primary_if;
 220
 221         primary_if = batadv_primary_if_get_selected(bat_priv);
 222         if (!primary_if)
 223                 goto out;
 224
 225         batadv_dat_init_own_addr(bat_priv, primary_if);
 226         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 227 out:
 228         if (primary_if)
 229                 batadv_hardif_put(primary_if);
 230 }
 231
 232 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 233                                      struct batadv_hard_iface *new_hard_iface)
 234 {
 235         struct batadv_hard_iface *curr_hard_iface;
 236
 237         ASSERT_RTNL();
 238
 239         if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount))
 240                 new_hard_iface = NULL;
 241
 242         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 243         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 244
 245         if (!new_hard_iface)
 246                 goto out;
 247
 248         bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
 249         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 250
 251 out:
 252         if (curr_hard_iface)
 253                 batadv_hardif_put(curr_hard_iface);
 254 }
 255
 256 static bool
 257 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 258 {
 259         if (hard_iface->net_dev->flags & IFF_UP)
 260                 return true;
 261
 262         return false;
 263 }
 264
 265 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 266 {
 267         const struct batadv_hard_iface *hard_iface;
 268
 269         rcu_read_lock();
 270         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 271                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 272                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 273                         continue;
 274
 275                 if (hard_iface->net_dev == net_dev)
 276                         continue;
 277
 278                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 279                                         net_dev->dev_addr))
 280                         continue;
 281
 282                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 283                         net_dev->dev_addr, hard_iface->net_dev->name);
 284                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 285         }
 286         rcu_read_unlock();
 287 }
 288
 289 /**
 290  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 291  * @soft_iface: netdev struct of the mesh interface
 292  */
 293 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 294 {
 295         const struct batadv_hard_iface *hard_iface;
 296         unsigned short lower_header_len = ETH_HLEN;
 297         unsigned short lower_headroom = 0;
 298         unsigned short lower_tailroom = 0;
 299         unsigned short needed_headroom;
 300
 301         rcu_read_lock();
 302         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 303                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 304                         continue;
 305
 306                 if (hard_iface->soft_iface != soft_iface)
 307                         continue;
 308
 309                 lower_header_len = max_t(unsigned short, lower_header_len,
 310                                          hard_iface->net_dev->hard_header_len);
 311
 312                 lower_headroom = max_t(unsigned short, lower_headroom,
 313                                        hard_iface->net_dev->needed_headroom);
 314
 315                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 316                                        hard_iface->net_dev->needed_tailroom);
 317         }
 318         rcu_read_unlock();
 319
 320         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 321         needed_headroom += batadv_max_header_len();
 322
 323         soft_iface->needed_headroom = needed_headroom;
 324         soft_iface->needed_tailroom = lower_tailroom;
 325 }
 326
 327 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 328 {
 329         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 330         const struct batadv_hard_iface *hard_iface;
 331         int min_mtu = INT_MAX;
 332
 333         rcu_read_lock();
 334         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 335                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 336                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 337                         continue;
 338
 339                 if (hard_iface->soft_iface != soft_iface)
 340                         continue;
 341
 342                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 343         }
 344         rcu_read_unlock();
 345
 346         if (atomic_read(&bat_priv->fragmentation) == 0)
 347                 goto out;
 348
 349         /* with fragmentation enabled the maximum size of internally generated
 350          * packets such as translation table exchanges or tvlv containers, etc
 351          * has to be calculated
 352          */
 353         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 354         min_mtu -= sizeof(struct batadv_frag_packet);
 355         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 356
 357 out:
 358         /* report to the other components the maximum amount of bytes that
 359          * batman-adv can send over the wire (without considering the payload
 360          * overhead). For example, this value is used by TT to compute the
 361          * maximum local table table size
 362          */
 363         atomic_set(&bat_priv->packet_size_max, min_mtu);
 364
 365         /* the real soft-interface MTU is computed by removing the payload
 366          * overhead from the maximum amount of bytes that was just computed.
 367          *
 368          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 369          */
 370         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 371 }
 372
 373 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 374 void batadv_update_min_mtu(struct net_device *soft_iface)
 375 {
 376         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 377
 378         /* Check if the local translate table should be cleaned up to match a
 379          * new (and smaller) MTU.
 380          */
 381         batadv_tt_local_resize_to_mtu(soft_iface);
 382 }
 383
 384 static void
 385 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 386 {
 387         struct batadv_priv *bat_priv;
 388         struct batadv_hard_iface *primary_if = NULL;
 389
 390         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 391                 goto out;
 392
 393         bat_priv = netdev_priv(hard_iface->soft_iface);
 394
 395         bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 396         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 397
 398         /* the first active interface becomes our primary interface or
 399          * the next active interface after the old primary interface was removed
 400          */
 401         primary_if = batadv_primary_if_get_selected(bat_priv);
 402         if (!primary_if)
 403                 batadv_primary_if_select(bat_priv, hard_iface);
 404
 405         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 406                     hard_iface->net_dev->name);
 407
 408         batadv_update_min_mtu(hard_iface->soft_iface);
 409
 410 out:
 411         if (primary_if)
 412                 batadv_hardif_put(primary_if);
 413 }
 414
 415 static void
 416 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 417 {
 418         if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 419             (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 420                 return;
 421
 422         hard_iface->if_status = BATADV_IF_INACTIVE;
 423
 424         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 425                     hard_iface->net_dev->name);
 426
 427         batadv_update_min_mtu(hard_iface->soft_iface);
 428 }
 429
 430 /**
 431  * batadv_master_del_slave - remove hard_iface from the current master interface
 432  * @slave: the interface enslaved in another master
 433  * @master: the master from which slave has to be removed
 434  *
 435  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 436  * is free'd and master can correctly change its internal state.
 437  *
 438  * Return: 0 on success, a negative value representing the error otherwise
 439  */
 440 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 441                                    struct net_device *master)
 442 {
 443         int ret;
 444
 445         if (!master)
 446                 return 0;
 447
 448         ret = -EBUSY;
 449         if (master->netdev_ops->ndo_del_slave)
 450                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 451
 452         return ret;
 453 }
 454
 455 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 456                                    const char *iface_name)
 457 {
 458         struct batadv_priv *bat_priv;
 459         struct net_device *soft_iface, *master;
 460         __be16 ethertype = htons(ETH_P_BATMAN);
 461         int max_header_len = batadv_max_header_len();
 462         int ret;
 463
 464         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 465                 goto out;
 466
 467         if (!kref_get_unless_zero(&hard_iface->refcount))
 468                 goto out;
 469
 470         soft_iface = dev_get_by_name(&init_net, iface_name);
 471
 472         if (!soft_iface) {
 473                 soft_iface = batadv_softif_create(iface_name);
 474
 475                 if (!soft_iface) {
 476                         ret = -ENOMEM;
 477                         goto err;
 478                 }
 479
 480                 /* dev_get_by_name() increases the reference counter for us */
 481                 dev_hold(soft_iface);
 482         }
 483
 484         if (!batadv_softif_is_valid(soft_iface)) {
 485                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 486                        soft_iface->name);
 487                 ret = -EINVAL;
 488                 goto err_dev;
 489         }
 490
 491         /* check if the interface is enslaved in another virtual one and
 492          * in that case unlink it first
 493          */
 494         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 495         ret = batadv_master_del_slave(hard_iface, master);
 496         if (ret)
 497                 goto err_dev;
 498
 499         hard_iface->soft_iface = soft_iface;
 500         bat_priv = netdev_priv(hard_iface->soft_iface);
 501
 502         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 503                                            soft_iface, NULL, NULL);
 504         if (ret)
 505                 goto err_dev;
 506
 507         ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
 508         if (ret < 0)
 509                 goto err_upper;
 510
 511         hard_iface->if_num = bat_priv->num_ifaces;
 512         bat_priv->num_ifaces++;
 513         hard_iface->if_status = BATADV_IF_INACTIVE;
 514         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 515         if (ret < 0) {
 516                 bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 517                 bat_priv->num_ifaces--;
 518                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 519                 goto err_upper;
 520         }
 521
 522         hard_iface->batman_adv_ptype.type = ethertype;
 523         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 524         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 525         dev_add_pack(&hard_iface->batman_adv_ptype);
 526
 527         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 528                     hard_iface->net_dev->name);
 529
 530         if (atomic_read(&bat_priv->fragmentation) &&
 531             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 532                 batadv_info(hard_iface->soft_iface,
 533                             "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",
 534                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 535                             ETH_DATA_LEN + max_header_len);
 536
 537         if (!atomic_read(&bat_priv->fragmentation) &&
 538             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 539                 batadv_info(hard_iface->soft_iface,
 540                             "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",
 541                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 542                             ETH_DATA_LEN + max_header_len);
 543
 544         if (batadv_hardif_is_iface_up(hard_iface))
 545                 batadv_hardif_activate_interface(hard_iface);
 546         else
 547                 batadv_err(hard_iface->soft_iface,
 548                            "Not using interface %s (retrying later): interface not active\n",
 549                            hard_iface->net_dev->name);
 550
 551         batadv_hardif_recalc_extra_skbroom(soft_iface);
 552
 553         /* begin scheduling originator messages on that interface */
 554         batadv_schedule_bat_ogm(hard_iface);
 555
 556 out:
 557         return 0;
 558
 559 err_upper:
 560         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 561 err_dev:
 562         hard_iface->soft_iface = NULL;
 563         dev_put(soft_iface);
 564 err:
 565         batadv_hardif_put(hard_iface);
 566         return ret;
 567 }
 568
 569 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 570                                      enum batadv_hard_if_cleanup autodel)
 571 {
 572         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 573         struct batadv_hard_iface *primary_if = NULL;
 574
 575         if (hard_iface->if_status == BATADV_IF_ACTIVE)
 576                 batadv_hardif_deactivate_interface(hard_iface);
 577
 578         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 579                 goto out;
 580
 581         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 582                     hard_iface->net_dev->name);
 583         dev_remove_pack(&hard_iface->batman_adv_ptype);
 584
 585         bat_priv->num_ifaces--;
 586         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 587
 588         primary_if = batadv_primary_if_get_selected(bat_priv);
 589         if (hard_iface == primary_if) {
 590                 struct batadv_hard_iface *new_if;
 591
 592                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 593                 batadv_primary_if_select(bat_priv, new_if);
 594
 595                 if (new_if)
 596                         batadv_hardif_put(new_if);
 597         }
 598
 599         bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 600         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 601
 602         /* delete all references to this hard_iface */
 603         batadv_purge_orig_ref(bat_priv);
 604         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 605         dev_put(hard_iface->soft_iface);
 606
 607         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 608         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 609
 610         /* nobody uses this interface anymore */
 611         if (!bat_priv->num_ifaces) {
 612                 batadv_gw_check_client_stop(bat_priv);
 613
 614                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 615                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 616         }
 617
 618         hard_iface->soft_iface = NULL;
 619         batadv_hardif_put(hard_iface);
 620
 621 out:
 622         if (primary_if)
 623                 batadv_hardif_put(primary_if);
 624 }
 625
 626 /**
 627  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
 628  * @work: work queue item
 629  *
 630  * Free the parts of the hard interface which can not be removed under
 631  * rtnl lock (to prevent deadlock situations).
 632  */
 633 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
 634 {
 635         struct batadv_hard_iface *hard_iface;
 636
 637         hard_iface = container_of(work, struct batadv_hard_iface,
 638                                   cleanup_work);
 639
 640         batadv_debugfs_del_hardif(hard_iface);
 641         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 642         batadv_hardif_put(hard_iface);
 643 }
 644
 645 static struct batadv_hard_iface *
 646 batadv_hardif_add_interface(struct net_device *net_dev)
 647 {
 648         struct batadv_hard_iface *hard_iface;
 649         int ret;
 650
 651         ASSERT_RTNL();
 652
 653         ret = batadv_is_valid_iface(net_dev);
 654         if (ret != 1)
 655                 goto out;
 656
 657         dev_hold(net_dev);
 658
 659         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 660         if (!hard_iface)
 661                 goto release_dev;
 662
 663         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 664         if (ret)
 665                 goto free_if;
 666
 667         hard_iface->if_num = -1;
 668         hard_iface->net_dev = net_dev;
 669         hard_iface->soft_iface = NULL;
 670         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 671
 672         ret = batadv_debugfs_add_hardif(hard_iface);
 673         if (ret)
 674                 goto free_sysfs;
 675
 676         INIT_LIST_HEAD(&hard_iface->list);
 677         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 678         INIT_WORK(&hard_iface->cleanup_work,
 679                   batadv_hardif_remove_interface_finish);
 680
 681         spin_lock_init(&hard_iface->neigh_list_lock);
 682
 683         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 684         if (batadv_is_wifi_netdev(net_dev))
 685                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 686
 687         /* extra reference for return */
 688         kref_init(&hard_iface->refcount);
 689         kref_get(&hard_iface->refcount);
 690
 691         batadv_check_known_mac_addr(hard_iface->net_dev);
 692         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 693
 694         return hard_iface;
 695
 696 free_sysfs:
 697         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 698 free_if:
 699         kfree(hard_iface);
 700 release_dev:
 701         dev_put(net_dev);
 702 out:
 703         return NULL;
 704 }
 705
 706 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 707 {
 708         ASSERT_RTNL();
 709
 710         /* first deactivate interface */
 711         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 712                 batadv_hardif_disable_interface(hard_iface,
 713                                                 BATADV_IF_CLEANUP_AUTO);
 714
 715         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 716                 return;
 717
 718         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 719         queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
 720 }
 721
 722 void batadv_hardif_remove_interfaces(void)
 723 {
 724         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 725
 726         rtnl_lock();
 727         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 728                                  &batadv_hardif_list, list) {
 729                 list_del_rcu(&hard_iface->list);
 730                 batadv_hardif_remove_interface(hard_iface);
 731         }
 732         rtnl_unlock();
 733 }
 734
 735 static int batadv_hard_if_event(struct notifier_block *this,
 736                                 unsigned long event, void *ptr)
 737 {
 738         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 739         struct batadv_hard_iface *hard_iface;
 740         struct batadv_hard_iface *primary_if = NULL;
 741         struct batadv_priv *bat_priv;
 742
 743         if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
 744                 batadv_sysfs_add_meshif(net_dev);
 745                 bat_priv = netdev_priv(net_dev);
 746                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 747                 return NOTIFY_DONE;
 748         }
 749
 750         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 751         if (!hard_iface && (event == NETDEV_REGISTER ||
 752                             event == NETDEV_POST_TYPE_CHANGE))
 753                 hard_iface = batadv_hardif_add_interface(net_dev);
 754
 755         if (!hard_iface)
 756                 goto out;
 757
 758         switch (event) {
 759         case NETDEV_UP:
 760                 batadv_hardif_activate_interface(hard_iface);
 761                 break;
 762         case NETDEV_GOING_DOWN:
 763         case NETDEV_DOWN:
 764                 batadv_hardif_deactivate_interface(hard_iface);
 765                 break;
 766         case NETDEV_UNREGISTER:
 767         case NETDEV_PRE_TYPE_CHANGE:
 768                 list_del_rcu(&hard_iface->list);
 769
 770                 batadv_hardif_remove_interface(hard_iface);
 771                 break;
 772         case NETDEV_CHANGEMTU:
 773                 if (hard_iface->soft_iface)
 774                         batadv_update_min_mtu(hard_iface->soft_iface);
 775                 break;
 776         case NETDEV_CHANGEADDR:
 777                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 778                         goto hardif_put;
 779
 780                 batadv_check_known_mac_addr(hard_iface->net_dev);
 781
 782                 bat_priv = netdev_priv(hard_iface->soft_iface);
 783                 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 784
 785                 primary_if = batadv_primary_if_get_selected(bat_priv);
 786                 if (!primary_if)
 787                         goto hardif_put;
 788
 789                 if (hard_iface == primary_if)
 790                         batadv_primary_if_update_addr(bat_priv, NULL);
 791                 break;
 792         default:
 793                 break;
 794         }
 795
 796 hardif_put:
 797         batadv_hardif_put(hard_iface);
 798 out:
 799         if (primary_if)
 800                 batadv_hardif_put(primary_if);
 801         return NOTIFY_DONE;
 802 }
 803
 804 struct notifier_block batadv_hard_if_notifier = {
 805         .notifier_call = batadv_hard_if_event,
 806 };