net/batman-adv/hard-interface.c

   1 /* Copyright (C) 2007-2012 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, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "hard-interface.h"
  22 #include "soft-interface.h"
  23 #include "send.h"
  24 #include "translation-table.h"
  25 #include "routing.h"
  26 #include "bat_sysfs.h"
  27 #include "originator.h"
  28 #include "hash.h"
  29 #include "bridge_loop_avoidance.h"
  30
  31 #include <linux/if_arp.h>
  32
  33 void batadv_hardif_free_rcu(struct rcu_head *rcu)
  34 {
  35         struct hard_iface *hard_iface;
  36
  37         hard_iface = container_of(rcu, struct hard_iface, rcu);
  38         dev_put(hard_iface->net_dev);
  39         kfree(hard_iface);
  40 }
  41
  42 struct hard_iface *batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  43 {
  44         struct hard_iface *hard_iface;
  45
  46         rcu_read_lock();
  47         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  48                 if (hard_iface->net_dev == net_dev &&
  49                     atomic_inc_not_zero(&hard_iface->refcount))
  50                         goto out;
  51         }
  52
  53         hard_iface = NULL;
  54
  55 out:
  56         rcu_read_unlock();
  57         return hard_iface;
  58 }
  59
  60 static int batadv_is_valid_iface(const struct net_device *net_dev)
  61 {
  62         if (net_dev->flags & IFF_LOOPBACK)
  63                 return 0;
  64
  65         if (net_dev->type != ARPHRD_ETHER)
  66                 return 0;
  67
  68         if (net_dev->addr_len != ETH_ALEN)
  69                 return 0;
  70
  71         /* no batman over batman */
  72         if (batadv_softif_is_valid(net_dev))
  73                 return 0;
  74
  75         return 1;
  76 }
  77
  78 static struct hard_iface *
  79 batadv_hardif_get_active(const struct net_device *soft_iface)
  80 {
  81         struct hard_iface *hard_iface;
  82
  83         rcu_read_lock();
  84         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  85                 if (hard_iface->soft_iface != soft_iface)
  86                         continue;
  87
  88                 if (hard_iface->if_status == IF_ACTIVE &&
  89                     atomic_inc_not_zero(&hard_iface->refcount))
  90                         goto out;
  91         }
  92
  93         hard_iface = NULL;
  94
  95 out:
  96         rcu_read_unlock();
  97         return hard_iface;
  98 }
  99
 100 static void batadv_primary_if_update_addr(struct bat_priv *bat_priv,
 101                                           struct hard_iface *oldif)
 102 {
 103         struct vis_packet *vis_packet;
 104         struct hard_iface *primary_if;
 105
 106         primary_if = batadv_primary_if_get_selected(bat_priv);
 107         if (!primary_if)
 108                 goto out;
 109
 110         vis_packet = (struct vis_packet *)
 111                                 bat_priv->my_vis_info->skb_packet->data;
 112         memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 113         memcpy(vis_packet->sender_orig,
 114                primary_if->net_dev->dev_addr, ETH_ALEN);
 115
 116         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 117 out:
 118         if (primary_if)
 119                 batadv_hardif_free_ref(primary_if);
 120 }
 121
 122 static void batadv_primary_if_select(struct bat_priv *bat_priv,
 123                                      struct hard_iface *new_hard_iface)
 124 {
 125         struct hard_iface *curr_hard_iface;
 126
 127         ASSERT_RTNL();
 128
 129         if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
 130                 new_hard_iface = NULL;
 131
 132         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 133         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 134
 135         if (!new_hard_iface)
 136                 goto out;
 137
 138         bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
 139         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 140
 141 out:
 142         if (curr_hard_iface)
 143                 batadv_hardif_free_ref(curr_hard_iface);
 144 }
 145
 146 static bool batadv_hardif_is_iface_up(const struct hard_iface *hard_iface)
 147 {
 148         if (hard_iface->net_dev->flags & IFF_UP)
 149                 return true;
 150
 151         return false;
 152 }
 153
 154 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 155 {
 156         const struct hard_iface *hard_iface;
 157
 158         rcu_read_lock();
 159         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 160                 if ((hard_iface->if_status != IF_ACTIVE) &&
 161                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 162                         continue;
 163
 164                 if (hard_iface->net_dev == net_dev)
 165                         continue;
 166
 167                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 168                                         net_dev->dev_addr))
 169                         continue;
 170
 171                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 172                         net_dev->dev_addr, hard_iface->net_dev->name);
 173                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 174         }
 175         rcu_read_unlock();
 176 }
 177
 178 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 179 {
 180         const struct bat_priv *bat_priv = netdev_priv(soft_iface);
 181         const struct hard_iface *hard_iface;
 182         /* allow big frames if all devices are capable to do so
 183          * (have MTU > 1500 + BAT_HEADER_LEN)
 184          */
 185         int min_mtu = ETH_DATA_LEN;
 186
 187         if (atomic_read(&bat_priv->fragmentation))
 188                 goto out;
 189
 190         rcu_read_lock();
 191         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 192                 if ((hard_iface->if_status != IF_ACTIVE) &&
 193                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 194                         continue;
 195
 196                 if (hard_iface->soft_iface != soft_iface)
 197                         continue;
 198
 199                 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
 200                                 min_mtu);
 201         }
 202         rcu_read_unlock();
 203 out:
 204         return min_mtu;
 205 }
 206
 207 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 208 void batadv_update_min_mtu(struct net_device *soft_iface)
 209 {
 210         int min_mtu;
 211
 212         min_mtu = batadv_hardif_min_mtu(soft_iface);
 213         if (soft_iface->mtu != min_mtu)
 214                 soft_iface->mtu = min_mtu;
 215 }
 216
 217 static void batadv_hardif_activate_interface(struct hard_iface *hard_iface)
 218 {
 219         struct bat_priv *bat_priv;
 220         struct hard_iface *primary_if = NULL;
 221
 222         if (hard_iface->if_status != IF_INACTIVE)
 223                 goto out;
 224
 225         bat_priv = netdev_priv(hard_iface->soft_iface);
 226
 227         bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 228         hard_iface->if_status = IF_TO_BE_ACTIVATED;
 229
 230         /* the first active interface becomes our primary interface or
 231          * the next active interface after the old primary interface was removed
 232          */
 233         primary_if = batadv_primary_if_get_selected(bat_priv);
 234         if (!primary_if)
 235                 batadv_primary_if_select(bat_priv, hard_iface);
 236
 237         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 238                     hard_iface->net_dev->name);
 239
 240         batadv_update_min_mtu(hard_iface->soft_iface);
 241
 242 out:
 243         if (primary_if)
 244                 batadv_hardif_free_ref(primary_if);
 245 }
 246
 247 static void batadv_hardif_deactivate_interface(struct hard_iface *hard_iface)
 248 {
 249         if ((hard_iface->if_status != IF_ACTIVE) &&
 250             (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 251                 return;
 252
 253         hard_iface->if_status = IF_INACTIVE;
 254
 255         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 256                     hard_iface->net_dev->name);
 257
 258         batadv_update_min_mtu(hard_iface->soft_iface);
 259 }
 260
 261 int batadv_hardif_enable_interface(struct hard_iface *hard_iface,
 262                                    const char *iface_name)
 263 {
 264         struct bat_priv *bat_priv;
 265         struct net_device *soft_iface;
 266         __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
 267         int ret;
 268
 269         if (hard_iface->if_status != IF_NOT_IN_USE)
 270                 goto out;
 271
 272         if (!atomic_inc_not_zero(&hard_iface->refcount))
 273                 goto out;
 274
 275         /* hard-interface is part of a bridge */
 276         if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT)
 277                 pr_err("You are about to enable batman-adv on '%s' which already is part of a bridge. Unless you know exactly what you are doing this is probably wrong and won't work the way you think it would.\n",
 278                        hard_iface->net_dev->name);
 279
 280         soft_iface = dev_get_by_name(&init_net, iface_name);
 281
 282         if (!soft_iface) {
 283                 soft_iface = batadv_softif_create(iface_name);
 284
 285                 if (!soft_iface) {
 286                         ret = -ENOMEM;
 287                         goto err;
 288                 }
 289
 290                 /* dev_get_by_name() increases the reference counter for us */
 291                 dev_hold(soft_iface);
 292         }
 293
 294         if (!batadv_softif_is_valid(soft_iface)) {
 295                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 296                        soft_iface->name);
 297                 ret = -EINVAL;
 298                 goto err_dev;
 299         }
 300
 301         hard_iface->soft_iface = soft_iface;
 302         bat_priv = netdev_priv(hard_iface->soft_iface);
 303
 304         ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
 305         if (ret < 0)
 306                 goto err_dev;
 307
 308         hard_iface->if_num = bat_priv->num_ifaces;
 309         bat_priv->num_ifaces++;
 310         hard_iface->if_status = IF_INACTIVE;
 311         batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 312
 313         hard_iface->batman_adv_ptype.type = ethertype;
 314         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 315         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 316         dev_add_pack(&hard_iface->batman_adv_ptype);
 317
 318         atomic_set(&hard_iface->frag_seqno, 1);
 319         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 320                     hard_iface->net_dev->name);
 321
 322         if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 323                 ETH_DATA_LEN + BAT_HEADER_LEN)
 324                 batadv_info(hard_iface->soft_iface,
 325                             "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 %zi would solve the problem.\n",
 326                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 327                             ETH_DATA_LEN + BAT_HEADER_LEN);
 328
 329         if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 330                 ETH_DATA_LEN + BAT_HEADER_LEN)
 331                 batadv_info(hard_iface->soft_iface,
 332                             "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 %zi.\n",
 333                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 334                             ETH_DATA_LEN + BAT_HEADER_LEN);
 335
 336         if (batadv_hardif_is_iface_up(hard_iface))
 337                 batadv_hardif_activate_interface(hard_iface);
 338         else
 339                 batadv_err(hard_iface->soft_iface,
 340                            "Not using interface %s (retrying later): interface not active\n",
 341                            hard_iface->net_dev->name);
 342
 343         /* begin scheduling originator messages on that interface */
 344         batadv_schedule_bat_ogm(hard_iface);
 345
 346 out:
 347         return 0;
 348
 349 err_dev:
 350         dev_put(soft_iface);
 351 err:
 352         batadv_hardif_free_ref(hard_iface);
 353         return ret;
 354 }
 355
 356 void batadv_hardif_disable_interface(struct hard_iface *hard_iface)
 357 {
 358         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 359         struct hard_iface *primary_if = NULL;
 360
 361         if (hard_iface->if_status == IF_ACTIVE)
 362                 batadv_hardif_deactivate_interface(hard_iface);
 363
 364         if (hard_iface->if_status != IF_INACTIVE)
 365                 goto out;
 366
 367         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 368                     hard_iface->net_dev->name);
 369         dev_remove_pack(&hard_iface->batman_adv_ptype);
 370
 371         bat_priv->num_ifaces--;
 372         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 373
 374         primary_if = batadv_primary_if_get_selected(bat_priv);
 375         if (hard_iface == primary_if) {
 376                 struct hard_iface *new_if;
 377
 378                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 379                 batadv_primary_if_select(bat_priv, new_if);
 380
 381                 if (new_if)
 382                         batadv_hardif_free_ref(new_if);
 383         }
 384
 385         bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 386         hard_iface->if_status = IF_NOT_IN_USE;
 387
 388         /* delete all references to this hard_iface */
 389         batadv_purge_orig_ref(bat_priv);
 390         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 391         dev_put(hard_iface->soft_iface);
 392
 393         /* nobody uses this interface anymore */
 394         if (!bat_priv->num_ifaces)
 395                 batadv_softif_destroy(hard_iface->soft_iface);
 396
 397         hard_iface->soft_iface = NULL;
 398         batadv_hardif_free_ref(hard_iface);
 399
 400 out:
 401         if (primary_if)
 402                 batadv_hardif_free_ref(primary_if);
 403 }
 404
 405 static struct hard_iface *
 406 batadv_hardif_add_interface(struct net_device *net_dev)
 407 {
 408         struct hard_iface *hard_iface;
 409         int ret;
 410
 411         ASSERT_RTNL();
 412
 413         ret = batadv_is_valid_iface(net_dev);
 414         if (ret != 1)
 415                 goto out;
 416
 417         dev_hold(net_dev);
 418
 419         hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC);
 420         if (!hard_iface)
 421                 goto release_dev;
 422
 423         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 424         if (ret)
 425                 goto free_if;
 426
 427         hard_iface->if_num = -1;
 428         hard_iface->net_dev = net_dev;
 429         hard_iface->soft_iface = NULL;
 430         hard_iface->if_status = IF_NOT_IN_USE;
 431         INIT_LIST_HEAD(&hard_iface->list);
 432         /* extra reference for return */
 433         atomic_set(&hard_iface->refcount, 2);
 434
 435         batadv_check_known_mac_addr(hard_iface->net_dev);
 436         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 437
 438         /* This can't be called via a bat_priv callback because
 439          * we have no bat_priv yet.
 440          */
 441         atomic_set(&hard_iface->seqno, 1);
 442         hard_iface->packet_buff = NULL;
 443
 444         return hard_iface;
 445
 446 free_if:
 447         kfree(hard_iface);
 448 release_dev:
 449         dev_put(net_dev);
 450 out:
 451         return NULL;
 452 }
 453
 454 static void batadv_hardif_remove_interface(struct hard_iface *hard_iface)
 455 {
 456         ASSERT_RTNL();
 457
 458         /* first deactivate interface */
 459         if (hard_iface->if_status != IF_NOT_IN_USE)
 460                 batadv_hardif_disable_interface(hard_iface);
 461
 462         if (hard_iface->if_status != IF_NOT_IN_USE)
 463                 return;
 464
 465         hard_iface->if_status = IF_TO_BE_REMOVED;
 466         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 467         batadv_hardif_free_ref(hard_iface);
 468 }
 469
 470 void batadv_hardif_remove_interfaces(void)
 471 {
 472         struct hard_iface *hard_iface, *hard_iface_tmp;
 473
 474         rtnl_lock();
 475         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 476                                  &batadv_hardif_list, list) {
 477                 list_del_rcu(&hard_iface->list);
 478                 batadv_hardif_remove_interface(hard_iface);
 479         }
 480         rtnl_unlock();
 481 }
 482
 483 static int batadv_hard_if_event(struct notifier_block *this,
 484                                 unsigned long event, void *ptr)
 485 {
 486         struct net_device *net_dev = ptr;
 487         struct hard_iface *hard_iface = batadv_hardif_get_by_netdev(net_dev);
 488         struct hard_iface *primary_if = NULL;
 489         struct bat_priv *bat_priv;
 490
 491         if (!hard_iface && event == NETDEV_REGISTER)
 492                 hard_iface = batadv_hardif_add_interface(net_dev);
 493
 494         if (!hard_iface)
 495                 goto out;
 496
 497         switch (event) {
 498         case NETDEV_UP:
 499                 batadv_hardif_activate_interface(hard_iface);
 500                 break;
 501         case NETDEV_GOING_DOWN:
 502         case NETDEV_DOWN:
 503                 batadv_hardif_deactivate_interface(hard_iface);
 504                 break;
 505         case NETDEV_UNREGISTER:
 506                 list_del_rcu(&hard_iface->list);
 507
 508                 batadv_hardif_remove_interface(hard_iface);
 509                 break;
 510         case NETDEV_CHANGEMTU:
 511                 if (hard_iface->soft_iface)
 512                         batadv_update_min_mtu(hard_iface->soft_iface);
 513                 break;
 514         case NETDEV_CHANGEADDR:
 515                 if (hard_iface->if_status == IF_NOT_IN_USE)
 516                         goto hardif_put;
 517
 518                 batadv_check_known_mac_addr(hard_iface->net_dev);
 519
 520                 bat_priv = netdev_priv(hard_iface->soft_iface);
 521                 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 522
 523                 primary_if = batadv_primary_if_get_selected(bat_priv);
 524                 if (!primary_if)
 525                         goto hardif_put;
 526
 527                 if (hard_iface == primary_if)
 528                         batadv_primary_if_update_addr(bat_priv, NULL);
 529                 break;
 530         default:
 531                 break;
 532         }
 533
 534 hardif_put:
 535         batadv_hardif_free_ref(hard_iface);
 536 out:
 537         if (primary_if)
 538                 batadv_hardif_free_ref(primary_if);
 539         return NOTIFY_DONE;
 540 }
 541
 542 /* This function returns true if the interface represented by ifindex is a
 543  * 802.11 wireless device
 544  */
 545 bool batadv_is_wifi_iface(int ifindex)
 546 {
 547         struct net_device *net_device = NULL;
 548         bool ret = false;
 549
 550         if (ifindex == NULL_IFINDEX)
 551                 goto out;
 552
 553         net_device = dev_get_by_index(&init_net, ifindex);
 554         if (!net_device)
 555                 goto out;
 556
 557 #ifdef CONFIG_WIRELESS_EXT
 558         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 559          * check for wireless_handlers != NULL
 560          */
 561         if (net_device->wireless_handlers)
 562                 ret = true;
 563         else
 564 #endif
 565                 /* cfg80211 drivers have to set ieee80211_ptr */
 566                 if (net_device->ieee80211_ptr)
 567                         ret = true;
 568 out:
 569         if (net_device)
 570                 dev_put(net_device);
 571         return ret;
 572 }
 573
 574 struct notifier_block batadv_hard_if_notifier = {
 575         .notifier_call = batadv_hard_if_event,
 576 };