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.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kref.h>
  31 #include <linux/list.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/printk.h>
  34 #include <linux/rculist.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/workqueue.h>
  39
  40 #include "bat_algo.h"
  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         struct net *net = dev_net(net_dev);
 125         bool ret;
 126
 127         /* check if this is a batman-adv mesh interface */
 128         if (batadv_softif_is_valid(net_dev))
 129                 return true;
 130
 131         /* no more parents..stop recursion */
 132         if (dev_get_iflink(net_dev) == 0 ||
 133             dev_get_iflink(net_dev) == net_dev->ifindex)
 134                 return false;
 135
 136         /* recurse over the parent device */
 137         parent_dev = __dev_get_by_index(net, dev_get_iflink(net_dev));
 138         /* if we got a NULL parent_dev there is something broken.. */
 139         if (WARN(!parent_dev, "Cannot find parent device"))
 140                 return false;
 141
 142         if (batadv_mutual_parents(net_dev, parent_dev))
 143                 return false;
 144
 145         ret = batadv_is_on_batman_iface(parent_dev);
 146
 147         return ret;
 148 }
 149
 150 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 151 {
 152         if (net_dev->flags & IFF_LOOPBACK)
 153                 return false;
 154
 155         if (net_dev->type != ARPHRD_ETHER)
 156                 return false;
 157
 158         if (net_dev->addr_len != ETH_ALEN)
 159                 return false;
 160
 161         /* no batman over batman */
 162         if (batadv_is_on_batman_iface(net_dev))
 163                 return false;
 164
 165         return true;
 166 }
 167
 168 /**
 169  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
 170  *  interface
 171  * @net_device: the device to check
 172  *
 173  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 174  */
 175 bool batadv_is_wifi_netdev(struct net_device *net_device)
 176 {
 177         if (!net_device)
 178                 return false;
 179
 180 #ifdef CONFIG_WIRELESS_EXT
 181         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 182          * check for wireless_handlers != NULL
 183          */
 184         if (net_device->wireless_handlers)
 185                 return true;
 186 #endif
 187
 188         /* cfg80211 drivers have to set ieee80211_ptr */
 189         if (net_device->ieee80211_ptr)
 190                 return true;
 191
 192         return false;
 193 }
 194
 195 static struct batadv_hard_iface *
 196 batadv_hardif_get_active(const struct net_device *soft_iface)
 197 {
 198         struct batadv_hard_iface *hard_iface;
 199
 200         rcu_read_lock();
 201         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 202                 if (hard_iface->soft_iface != soft_iface)
 203                         continue;
 204
 205                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 206                     kref_get_unless_zero(&hard_iface->refcount))
 207                         goto out;
 208         }
 209
 210         hard_iface = NULL;
 211
 212 out:
 213         rcu_read_unlock();
 214         return hard_iface;
 215 }
 216
 217 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 218                                           struct batadv_hard_iface *oldif)
 219 {
 220         struct batadv_hard_iface *primary_if;
 221
 222         primary_if = batadv_primary_if_get_selected(bat_priv);
 223         if (!primary_if)
 224                 goto out;
 225
 226         batadv_dat_init_own_addr(bat_priv, primary_if);
 227         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 228 out:
 229         if (primary_if)
 230                 batadv_hardif_put(primary_if);
 231 }
 232
 233 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 234                                      struct batadv_hard_iface *new_hard_iface)
 235 {
 236         struct batadv_hard_iface *curr_hard_iface;
 237
 238         ASSERT_RTNL();
 239
 240         if (new_hard_iface)
 241                 kref_get(&new_hard_iface->refcount);
 242
 243         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 244         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 245
 246         if (!new_hard_iface)
 247                 goto out;
 248
 249         bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
 250         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 251
 252 out:
 253         if (curr_hard_iface)
 254                 batadv_hardif_put(curr_hard_iface);
 255 }
 256
 257 static bool
 258 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 259 {
 260         if (hard_iface->net_dev->flags & IFF_UP)
 261                 return true;
 262
 263         return false;
 264 }
 265
 266 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 267 {
 268         const struct batadv_hard_iface *hard_iface;
 269
 270         rcu_read_lock();
 271         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 272                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 273                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 274                         continue;
 275
 276                 if (hard_iface->net_dev == net_dev)
 277                         continue;
 278
 279                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 280                                         net_dev->dev_addr))
 281                         continue;
 282
 283                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 284                         net_dev->dev_addr, hard_iface->net_dev->name);
 285                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 286         }
 287         rcu_read_unlock();
 288 }
 289
 290 /**
 291  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 292  * @soft_iface: netdev struct of the mesh interface
 293  */
 294 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 295 {
 296         const struct batadv_hard_iface *hard_iface;
 297         unsigned short lower_header_len = ETH_HLEN;
 298         unsigned short lower_headroom = 0;
 299         unsigned short lower_tailroom = 0;
 300         unsigned short needed_headroom;
 301
 302         rcu_read_lock();
 303         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 304                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 305                         continue;
 306
 307                 if (hard_iface->soft_iface != soft_iface)
 308                         continue;
 309
 310                 lower_header_len = max_t(unsigned short, lower_header_len,
 311                                          hard_iface->net_dev->hard_header_len);
 312
 313                 lower_headroom = max_t(unsigned short, lower_headroom,
 314                                        hard_iface->net_dev->needed_headroom);
 315
 316                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 317                                        hard_iface->net_dev->needed_tailroom);
 318         }
 319         rcu_read_unlock();
 320
 321         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 322         needed_headroom += batadv_max_header_len();
 323
 324         soft_iface->needed_headroom = needed_headroom;
 325         soft_iface->needed_tailroom = lower_tailroom;
 326 }
 327
 328 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 329 {
 330         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 331         const struct batadv_hard_iface *hard_iface;
 332         int min_mtu = INT_MAX;
 333
 334         rcu_read_lock();
 335         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 336                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 337                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 338                         continue;
 339
 340                 if (hard_iface->soft_iface != soft_iface)
 341                         continue;
 342
 343                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 344         }
 345         rcu_read_unlock();
 346
 347         if (atomic_read(&bat_priv->fragmentation) == 0)
 348                 goto out;
 349
 350         /* with fragmentation enabled the maximum size of internally generated
 351          * packets such as translation table exchanges or tvlv containers, etc
 352          * has to be calculated
 353          */
 354         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 355         min_mtu -= sizeof(struct batadv_frag_packet);
 356         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 357
 358 out:
 359         /* report to the other components the maximum amount of bytes that
 360          * batman-adv can send over the wire (without considering the payload
 361          * overhead). For example, this value is used by TT to compute the
 362          * maximum local table table size
 363          */
 364         atomic_set(&bat_priv->packet_size_max, min_mtu);
 365
 366         /* the real soft-interface MTU is computed by removing the payload
 367          * overhead from the maximum amount of bytes that was just computed.
 368          *
 369          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 370          */
 371         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 372 }
 373
 374 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 375 void batadv_update_min_mtu(struct net_device *soft_iface)
 376 {
 377         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 378
 379         /* Check if the local translate table should be cleaned up to match a
 380          * new (and smaller) MTU.
 381          */
 382         batadv_tt_local_resize_to_mtu(soft_iface);
 383 }
 384
 385 static void
 386 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 387 {
 388         struct batadv_priv *bat_priv;
 389         struct batadv_hard_iface *primary_if = NULL;
 390
 391         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 392                 goto out;
 393
 394         bat_priv = netdev_priv(hard_iface->soft_iface);
 395
 396         bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 397         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 398
 399         /* the first active interface becomes our primary interface or
 400          * the next active interface after the old primary interface was removed
 401          */
 402         primary_if = batadv_primary_if_get_selected(bat_priv);
 403         if (!primary_if)
 404                 batadv_primary_if_select(bat_priv, hard_iface);
 405
 406         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 407                     hard_iface->net_dev->name);
 408
 409         batadv_update_min_mtu(hard_iface->soft_iface);
 410
 411         if (bat_priv->bat_algo_ops->bat_iface_activate)
 412                 bat_priv->bat_algo_ops->bat_iface_activate(hard_iface);
 413
 414 out:
 415         if (primary_if)
 416                 batadv_hardif_put(primary_if);
 417 }
 418
 419 static void
 420 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 421 {
 422         if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
 423             (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
 424                 return;
 425
 426         hard_iface->if_status = BATADV_IF_INACTIVE;
 427
 428         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 429                     hard_iface->net_dev->name);
 430
 431         batadv_update_min_mtu(hard_iface->soft_iface);
 432 }
 433
 434 /**
 435  * batadv_master_del_slave - remove hard_iface from the current master interface
 436  * @slave: the interface enslaved in another master
 437  * @master: the master from which slave has to be removed
 438  *
 439  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 440  * is free'd and master can correctly change its internal state.
 441  *
 442  * Return: 0 on success, a negative value representing the error otherwise
 443  */
 444 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 445                                    struct net_device *master)
 446 {
 447         int ret;
 448
 449         if (!master)
 450                 return 0;
 451
 452         ret = -EBUSY;
 453         if (master->netdev_ops->ndo_del_slave)
 454                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 455
 456         return ret;
 457 }
 458
 459 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 460                                    struct net *net, const char *iface_name)
 461 {
 462         struct batadv_priv *bat_priv;
 463         struct net_device *soft_iface, *master;
 464         __be16 ethertype = htons(ETH_P_BATMAN);
 465         int max_header_len = batadv_max_header_len();
 466         int ret;
 467
 468         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 469                 goto out;
 470
 471         kref_get(&hard_iface->refcount);
 472
 473         soft_iface = dev_get_by_name(net, iface_name);
 474
 475         if (!soft_iface) {
 476                 soft_iface = batadv_softif_create(net, iface_name);
 477
 478                 if (!soft_iface) {
 479                         ret = -ENOMEM;
 480                         goto err;
 481                 }
 482
 483                 /* dev_get_by_name() increases the reference counter for us */
 484                 dev_hold(soft_iface);
 485         }
 486
 487         if (!batadv_softif_is_valid(soft_iface)) {
 488                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 489                        soft_iface->name);
 490                 ret = -EINVAL;
 491                 goto err_dev;
 492         }
 493
 494         /* check if the interface is enslaved in another virtual one and
 495          * in that case unlink it first
 496          */
 497         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 498         ret = batadv_master_del_slave(hard_iface, master);
 499         if (ret)
 500                 goto err_dev;
 501
 502         hard_iface->soft_iface = soft_iface;
 503         bat_priv = netdev_priv(hard_iface->soft_iface);
 504
 505         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 506                                            soft_iface, NULL, NULL);
 507         if (ret)
 508                 goto err_dev;
 509
 510         ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
 511         if (ret < 0)
 512                 goto err_upper;
 513
 514         hard_iface->if_num = bat_priv->num_ifaces;
 515         bat_priv->num_ifaces++;
 516         hard_iface->if_status = BATADV_IF_INACTIVE;
 517         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 518         if (ret < 0) {
 519                 bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 520                 bat_priv->num_ifaces--;
 521                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 522                 goto err_upper;
 523         }
 524
 525         kref_get(&hard_iface->refcount);
 526         hard_iface->batman_adv_ptype.type = ethertype;
 527         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 528         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 529         dev_add_pack(&hard_iface->batman_adv_ptype);
 530
 531         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 532                     hard_iface->net_dev->name);
 533
 534         if (atomic_read(&bat_priv->fragmentation) &&
 535             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 536                 batadv_info(hard_iface->soft_iface,
 537                             "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",
 538                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 539                             ETH_DATA_LEN + max_header_len);
 540
 541         if (!atomic_read(&bat_priv->fragmentation) &&
 542             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 543                 batadv_info(hard_iface->soft_iface,
 544                             "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",
 545                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 546                             ETH_DATA_LEN + max_header_len);
 547
 548         if (batadv_hardif_is_iface_up(hard_iface))
 549                 batadv_hardif_activate_interface(hard_iface);
 550         else
 551                 batadv_err(hard_iface->soft_iface,
 552                            "Not using interface %s (retrying later): interface not active\n",
 553                            hard_iface->net_dev->name);
 554
 555         batadv_hardif_recalc_extra_skbroom(soft_iface);
 556
 557 out:
 558         return 0;
 559
 560 err_upper:
 561         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 562 err_dev:
 563         hard_iface->soft_iface = NULL;
 564         dev_put(soft_iface);
 565 err:
 566         batadv_hardif_put(hard_iface);
 567         return ret;
 568 }
 569
 570 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 571                                      enum batadv_hard_if_cleanup autodel)
 572 {
 573         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 574         struct batadv_hard_iface *primary_if = NULL;
 575
 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         batadv_hardif_put(hard_iface);
 585
 586         bat_priv->num_ifaces--;
 587         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 588
 589         primary_if = batadv_primary_if_get_selected(bat_priv);
 590         if (hard_iface == primary_if) {
 591                 struct batadv_hard_iface *new_if;
 592
 593                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 594                 batadv_primary_if_select(bat_priv, new_if);
 595
 596                 if (new_if)
 597                         batadv_hardif_put(new_if);
 598         }
 599
 600         bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 601         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 602
 603         /* delete all references to this hard_iface */
 604         batadv_purge_orig_ref(bat_priv);
 605         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 606         dev_put(hard_iface->soft_iface);
 607
 608         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 609         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 610
 611         /* nobody uses this interface anymore */
 612         if (!bat_priv->num_ifaces) {
 613                 batadv_gw_check_client_stop(bat_priv);
 614
 615                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 616                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 617         }
 618
 619         hard_iface->soft_iface = NULL;
 620         batadv_hardif_put(hard_iface);
 621
 622 out:
 623         if (primary_if)
 624                 batadv_hardif_put(primary_if);
 625 }
 626
 627 /**
 628  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
 629  * @work: work queue item
 630  *
 631  * Free the parts of the hard interface which can not be removed under
 632  * rtnl lock (to prevent deadlock situations).
 633  */
 634 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
 635 {
 636         struct batadv_hard_iface *hard_iface;
 637
 638         hard_iface = container_of(work, struct batadv_hard_iface,
 639                                   cleanup_work);
 640
 641         batadv_debugfs_del_hardif(hard_iface);
 642         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 643         batadv_hardif_put(hard_iface);
 644 }
 645
 646 static struct batadv_hard_iface *
 647 batadv_hardif_add_interface(struct net_device *net_dev)
 648 {
 649         struct batadv_hard_iface *hard_iface;
 650         int ret;
 651
 652         ASSERT_RTNL();
 653
 654         if (!batadv_is_valid_iface(net_dev))
 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         batadv_v_hardif_init(hard_iface);
 688
 689         /* extra reference for return */
 690         kref_init(&hard_iface->refcount);
 691         kref_get(&hard_iface->refcount);
 692
 693         batadv_check_known_mac_addr(hard_iface->net_dev);
 694         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 695
 696         return hard_iface;
 697
 698 free_sysfs:
 699         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 700 free_if:
 701         kfree(hard_iface);
 702 release_dev:
 703         dev_put(net_dev);
 704 out:
 705         return NULL;
 706 }
 707
 708 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 709 {
 710         ASSERT_RTNL();
 711
 712         /* first deactivate interface */
 713         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 714                 batadv_hardif_disable_interface(hard_iface,
 715                                                 BATADV_IF_CLEANUP_AUTO);
 716
 717         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 718                 return;
 719
 720         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 721         queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
 722 }
 723
 724 void batadv_hardif_remove_interfaces(void)
 725 {
 726         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 727
 728         rtnl_lock();
 729         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 730                                  &batadv_hardif_list, list) {
 731                 list_del_rcu(&hard_iface->list);
 732                 batadv_hardif_remove_interface(hard_iface);
 733         }
 734         rtnl_unlock();
 735 }
 736
 737 static int batadv_hard_if_event(struct notifier_block *this,
 738                                 unsigned long event, void *ptr)
 739 {
 740         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
 741         struct batadv_hard_iface *hard_iface;
 742         struct batadv_hard_iface *primary_if = NULL;
 743         struct batadv_priv *bat_priv;
 744
 745         if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
 746                 batadv_sysfs_add_meshif(net_dev);
 747                 bat_priv = netdev_priv(net_dev);
 748                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 749                 return NOTIFY_DONE;
 750         }
 751
 752         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 753         if (!hard_iface && (event == NETDEV_REGISTER ||
 754                             event == NETDEV_POST_TYPE_CHANGE))
 755                 hard_iface = batadv_hardif_add_interface(net_dev);
 756
 757         if (!hard_iface)
 758                 goto out;
 759
 760         switch (event) {
 761         case NETDEV_UP:
 762                 batadv_hardif_activate_interface(hard_iface);
 763                 break;
 764         case NETDEV_GOING_DOWN:
 765         case NETDEV_DOWN:
 766                 batadv_hardif_deactivate_interface(hard_iface);
 767                 break;
 768         case NETDEV_UNREGISTER:
 769         case NETDEV_PRE_TYPE_CHANGE:
 770                 list_del_rcu(&hard_iface->list);
 771
 772                 batadv_hardif_remove_interface(hard_iface);
 773                 break;
 774         case NETDEV_CHANGEMTU:
 775                 if (hard_iface->soft_iface)
 776                         batadv_update_min_mtu(hard_iface->soft_iface);
 777                 break;
 778         case NETDEV_CHANGEADDR:
 779                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 780                         goto hardif_put;
 781
 782                 batadv_check_known_mac_addr(hard_iface->net_dev);
 783
 784                 bat_priv = netdev_priv(hard_iface->soft_iface);
 785                 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 786
 787                 primary_if = batadv_primary_if_get_selected(bat_priv);
 788                 if (!primary_if)
 789                         goto hardif_put;
 790
 791                 if (hard_iface == primary_if)
 792                         batadv_primary_if_update_addr(bat_priv, NULL);
 793                 break;
 794         default:
 795                 break;
 796         }
 797
 798 hardif_put:
 799         batadv_hardif_put(hard_iface);
 800 out:
 801         if (primary_if)
 802                 batadv_hardif_put(primary_if);
 803         return NOTIFY_DONE;
 804 }
 805
 806 struct notifier_block batadv_hard_if_notifier = {
 807         .notifier_call = batadv_hard_if_event,
 808 };