net/batman-adv/hard-interface.c

   1 /*
   2  * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "hard-interface.h"
  24 #include "soft-interface.h"
  25 #include "send.h"
  26 #include "translation-table.h"
  27 #include "routing.h"
  28 #include "bat_sysfs.h"
  29 #include "originator.h"
  30 #include "hash.h"
  31 #include "bridge_loop_avoidance.h"
  32
  33 #include <linux/if_arp.h>
  34
  35 void hardif_free_rcu(struct rcu_head *rcu)
  36 {
  37         struct hard_iface *hard_iface;
  38
  39         hard_iface = container_of(rcu, struct hard_iface, rcu);
  40         dev_put(hard_iface->net_dev);
  41         kfree(hard_iface);
  42 }
  43
  44 struct hard_iface *hardif_get_by_netdev(const struct net_device *net_dev)
  45 {
  46         struct hard_iface *hard_iface;
  47
  48         rcu_read_lock();
  49         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  50                 if (hard_iface->net_dev == net_dev &&
  51                     atomic_inc_not_zero(&hard_iface->refcount))
  52                         goto out;
  53         }
  54
  55         hard_iface = NULL;
  56
  57 out:
  58         rcu_read_unlock();
  59         return hard_iface;
  60 }
  61
  62 static int is_valid_iface(const struct net_device *net_dev)
  63 {
  64         if (net_dev->flags & IFF_LOOPBACK)
  65                 return 0;
  66
  67         if (net_dev->type != ARPHRD_ETHER)
  68                 return 0;
  69
  70         if (net_dev->addr_len != ETH_ALEN)
  71                 return 0;
  72
  73         /* no batman over batman */
  74         if (softif_is_valid(net_dev))
  75                 return 0;
  76
  77         /* Device is being bridged */
  78         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
  79                 return 0; */
  80
  81         return 1;
  82 }
  83
  84 static struct hard_iface *hardif_get_active(const struct net_device *soft_iface)
  85 {
  86         struct hard_iface *hard_iface;
  87
  88         rcu_read_lock();
  89         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  90                 if (hard_iface->soft_iface != soft_iface)
  91                         continue;
  92
  93                 if (hard_iface->if_status == IF_ACTIVE &&
  94                     atomic_inc_not_zero(&hard_iface->refcount))
  95                         goto out;
  96         }
  97
  98         hard_iface = NULL;
  99
 100 out:
 101         rcu_read_unlock();
 102         return hard_iface;
 103 }
 104
 105 static void primary_if_update_addr(struct bat_priv *bat_priv,
 106                                    struct hard_iface *oldif)
 107 {
 108         struct vis_packet *vis_packet;
 109         struct hard_iface *primary_if;
 110
 111         primary_if = primary_if_get_selected(bat_priv);
 112         if (!primary_if)
 113                 goto out;
 114
 115         vis_packet = (struct vis_packet *)
 116                                 bat_priv->my_vis_info->skb_packet->data;
 117         memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 118         memcpy(vis_packet->sender_orig,
 119                primary_if->net_dev->dev_addr, ETH_ALEN);
 120
 121         bla_update_orig_address(bat_priv, primary_if, oldif);
 122 out:
 123         if (primary_if)
 124                 hardif_free_ref(primary_if);
 125 }
 126
 127 static void primary_if_select(struct bat_priv *bat_priv,
 128                               struct hard_iface *new_hard_iface)
 129 {
 130         struct hard_iface *curr_hard_iface;
 131
 132         ASSERT_RTNL();
 133
 134         if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
 135                 new_hard_iface = NULL;
 136
 137         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 138         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 139
 140         if (!new_hard_iface)
 141                 goto out;
 142
 143         bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
 144         primary_if_update_addr(bat_priv, curr_hard_iface);
 145
 146 out:
 147         if (curr_hard_iface)
 148                 hardif_free_ref(curr_hard_iface);
 149 }
 150
 151 static bool hardif_is_iface_up(const struct hard_iface *hard_iface)
 152 {
 153         if (hard_iface->net_dev->flags & IFF_UP)
 154                 return true;
 155
 156         return false;
 157 }
 158
 159 static void check_known_mac_addr(const struct net_device *net_dev)
 160 {
 161         const struct hard_iface *hard_iface;
 162
 163         rcu_read_lock();
 164         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 165                 if ((hard_iface->if_status != IF_ACTIVE) &&
 166                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 167                         continue;
 168
 169                 if (hard_iface->net_dev == net_dev)
 170                         continue;
 171
 172                 if (!compare_eth(hard_iface->net_dev->dev_addr,
 173                                  net_dev->dev_addr))
 174                         continue;
 175
 176                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 177                         net_dev->dev_addr, hard_iface->net_dev->name);
 178                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 179         }
 180         rcu_read_unlock();
 181 }
 182
 183 int hardif_min_mtu(struct net_device *soft_iface)
 184 {
 185         const struct bat_priv *bat_priv = netdev_priv(soft_iface);
 186         const struct hard_iface *hard_iface;
 187         /* allow big frames if all devices are capable to do so
 188          * (have MTU > 1500 + BAT_HEADER_LEN) */
 189         int min_mtu = ETH_DATA_LEN;
 190
 191         if (atomic_read(&bat_priv->fragmentation))
 192                 goto out;
 193
 194         rcu_read_lock();
 195         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 196                 if ((hard_iface->if_status != IF_ACTIVE) &&
 197                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 198                         continue;
 199
 200                 if (hard_iface->soft_iface != soft_iface)
 201                         continue;
 202
 203                 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
 204                                 min_mtu);
 205         }
 206         rcu_read_unlock();
 207 out:
 208         return min_mtu;
 209 }
 210
 211 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 212 void update_min_mtu(struct net_device *soft_iface)
 213 {
 214         int min_mtu;
 215
 216         min_mtu = hardif_min_mtu(soft_iface);
 217         if (soft_iface->mtu != min_mtu)
 218                 soft_iface->mtu = min_mtu;
 219 }
 220
 221 static void hardif_activate_interface(struct hard_iface *hard_iface)
 222 {
 223         struct bat_priv *bat_priv;
 224         struct hard_iface *primary_if = NULL;
 225
 226         if (hard_iface->if_status != IF_INACTIVE)
 227                 goto out;
 228
 229         bat_priv = netdev_priv(hard_iface->soft_iface);
 230
 231         bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 232         hard_iface->if_status = IF_TO_BE_ACTIVATED;
 233
 234         /**
 235          * the first active interface becomes our primary interface or
 236          * the next active interface after the old primary interface was removed
 237          */
 238         primary_if = primary_if_get_selected(bat_priv);
 239         if (!primary_if)
 240                 primary_if_select(bat_priv, hard_iface);
 241
 242         bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
 243                  hard_iface->net_dev->name);
 244
 245         update_min_mtu(hard_iface->soft_iface);
 246
 247 out:
 248         if (primary_if)
 249                 hardif_free_ref(primary_if);
 250 }
 251
 252 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
 253 {
 254         if ((hard_iface->if_status != IF_ACTIVE) &&
 255             (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 256                 return;
 257
 258         hard_iface->if_status = IF_INACTIVE;
 259
 260         bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 261                  hard_iface->net_dev->name);
 262
 263         update_min_mtu(hard_iface->soft_iface);
 264 }
 265
 266 int hardif_enable_interface(struct hard_iface *hard_iface,
 267                             const char *iface_name)
 268 {
 269         struct bat_priv *bat_priv;
 270         struct net_device *soft_iface;
 271         int ret;
 272
 273         if (hard_iface->if_status != IF_NOT_IN_USE)
 274                 goto out;
 275
 276         if (!atomic_inc_not_zero(&hard_iface->refcount))
 277                 goto out;
 278
 279         /* hard-interface is part of a bridge */
 280         if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT)
 281                 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",
 282                        hard_iface->net_dev->name);
 283
 284         soft_iface = dev_get_by_name(&init_net, iface_name);
 285
 286         if (!soft_iface) {
 287                 soft_iface = softif_create(iface_name);
 288
 289                 if (!soft_iface) {
 290                         ret = -ENOMEM;
 291                         goto err;
 292                 }
 293
 294                 /* dev_get_by_name() increases the reference counter for us */
 295                 dev_hold(soft_iface);
 296         }
 297
 298         if (!softif_is_valid(soft_iface)) {
 299                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 300                        soft_iface->name);
 301                 ret = -EINVAL;
 302                 goto err_dev;
 303         }
 304
 305         hard_iface->soft_iface = soft_iface;
 306         bat_priv = netdev_priv(hard_iface->soft_iface);
 307
 308         ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
 309         if (ret < 0) {
 310                 ret = -ENOMEM;
 311                 goto err_dev;
 312         }
 313
 314         hard_iface->if_num = bat_priv->num_ifaces;
 315         bat_priv->num_ifaces++;
 316         hard_iface->if_status = IF_INACTIVE;
 317         orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 318
 319         hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 320         hard_iface->batman_adv_ptype.func = batman_skb_recv;
 321         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 322         dev_add_pack(&hard_iface->batman_adv_ptype);
 323
 324         atomic_set(&hard_iface->frag_seqno, 1);
 325         bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
 326                  hard_iface->net_dev->name);
 327
 328         if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 329                 ETH_DATA_LEN + BAT_HEADER_LEN)
 330                 bat_info(hard_iface->soft_iface,
 331                          "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",
 332                          hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 333                          ETH_DATA_LEN + BAT_HEADER_LEN);
 334
 335         if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 336                 ETH_DATA_LEN + BAT_HEADER_LEN)
 337                 bat_info(hard_iface->soft_iface,
 338                          "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",
 339                          hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 340                          ETH_DATA_LEN + BAT_HEADER_LEN);
 341
 342         if (hardif_is_iface_up(hard_iface))
 343                 hardif_activate_interface(hard_iface);
 344         else
 345                 bat_err(hard_iface->soft_iface,
 346                         "Not using interface %s (retrying later): interface not active\n",
 347                         hard_iface->net_dev->name);
 348
 349         /* begin scheduling originator messages on that interface */
 350         schedule_bat_ogm(hard_iface);
 351
 352 out:
 353         return 0;
 354
 355 err_dev:
 356         dev_put(soft_iface);
 357 err:
 358         hardif_free_ref(hard_iface);
 359         return ret;
 360 }
 361
 362 void hardif_disable_interface(struct hard_iface *hard_iface)
 363 {
 364         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 365         struct hard_iface *primary_if = NULL;
 366
 367         if (hard_iface->if_status == IF_ACTIVE)
 368                 hardif_deactivate_interface(hard_iface);
 369
 370         if (hard_iface->if_status != IF_INACTIVE)
 371                 goto out;
 372
 373         bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
 374                  hard_iface->net_dev->name);
 375         dev_remove_pack(&hard_iface->batman_adv_ptype);
 376
 377         bat_priv->num_ifaces--;
 378         orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 379
 380         primary_if = primary_if_get_selected(bat_priv);
 381         if (hard_iface == primary_if) {
 382                 struct hard_iface *new_if;
 383
 384                 new_if = hardif_get_active(hard_iface->soft_iface);
 385                 primary_if_select(bat_priv, new_if);
 386
 387                 if (new_if)
 388                         hardif_free_ref(new_if);
 389         }
 390
 391         bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
 392         hard_iface->if_status = IF_NOT_IN_USE;
 393
 394         /* delete all references to this hard_iface */
 395         purge_orig_ref(bat_priv);
 396         purge_outstanding_packets(bat_priv, hard_iface);
 397         dev_put(hard_iface->soft_iface);
 398
 399         /* nobody uses this interface anymore */
 400         if (!bat_priv->num_ifaces)
 401                 softif_destroy(hard_iface->soft_iface);
 402
 403         hard_iface->soft_iface = NULL;
 404         hardif_free_ref(hard_iface);
 405
 406 out:
 407         if (primary_if)
 408                 hardif_free_ref(primary_if);
 409 }
 410
 411 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
 412 {
 413         struct hard_iface *hard_iface;
 414         int ret;
 415
 416         ASSERT_RTNL();
 417
 418         ret = is_valid_iface(net_dev);
 419         if (ret != 1)
 420                 goto out;
 421
 422         dev_hold(net_dev);
 423
 424         hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC);
 425         if (!hard_iface)
 426                 goto release_dev;
 427
 428         ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 429         if (ret)
 430                 goto free_if;
 431
 432         hard_iface->if_num = -1;
 433         hard_iface->net_dev = net_dev;
 434         hard_iface->soft_iface = NULL;
 435         hard_iface->if_status = IF_NOT_IN_USE;
 436         INIT_LIST_HEAD(&hard_iface->list);
 437         /* extra reference for return */
 438         atomic_set(&hard_iface->refcount, 2);
 439
 440         check_known_mac_addr(hard_iface->net_dev);
 441         list_add_tail_rcu(&hard_iface->list, &hardif_list);
 442
 443         /**
 444          * This can't be called via a bat_priv callback because
 445          * we have no bat_priv yet.
 446          */
 447         atomic_set(&hard_iface->seqno, 1);
 448         hard_iface->packet_buff = NULL;
 449
 450         return hard_iface;
 451
 452 free_if:
 453         kfree(hard_iface);
 454 release_dev:
 455         dev_put(net_dev);
 456 out:
 457         return NULL;
 458 }
 459
 460 static void hardif_remove_interface(struct hard_iface *hard_iface)
 461 {
 462         ASSERT_RTNL();
 463
 464         /* first deactivate interface */
 465         if (hard_iface->if_status != IF_NOT_IN_USE)
 466                 hardif_disable_interface(hard_iface);
 467
 468         if (hard_iface->if_status != IF_NOT_IN_USE)
 469                 return;
 470
 471         hard_iface->if_status = IF_TO_BE_REMOVED;
 472         sysfs_del_hardif(&hard_iface->hardif_obj);
 473         hardif_free_ref(hard_iface);
 474 }
 475
 476 void hardif_remove_interfaces(void)
 477 {
 478         struct hard_iface *hard_iface, *hard_iface_tmp;
 479
 480         rtnl_lock();
 481         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 482                                  &hardif_list, list) {
 483                 list_del_rcu(&hard_iface->list);
 484                 hardif_remove_interface(hard_iface);
 485         }
 486         rtnl_unlock();
 487 }
 488
 489 static int hard_if_event(struct notifier_block *this,
 490                          unsigned long event, void *ptr)
 491 {
 492         struct net_device *net_dev = ptr;
 493         struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
 494         struct hard_iface *primary_if = NULL;
 495         struct bat_priv *bat_priv;
 496
 497         if (!hard_iface && event == NETDEV_REGISTER)
 498                 hard_iface = hardif_add_interface(net_dev);
 499
 500         if (!hard_iface)
 501                 goto out;
 502
 503         switch (event) {
 504         case NETDEV_UP:
 505                 hardif_activate_interface(hard_iface);
 506                 break;
 507         case NETDEV_GOING_DOWN:
 508         case NETDEV_DOWN:
 509                 hardif_deactivate_interface(hard_iface);
 510                 break;
 511         case NETDEV_UNREGISTER:
 512                 list_del_rcu(&hard_iface->list);
 513
 514                 hardif_remove_interface(hard_iface);
 515                 break;
 516         case NETDEV_CHANGEMTU:
 517                 if (hard_iface->soft_iface)
 518                         update_min_mtu(hard_iface->soft_iface);
 519                 break;
 520         case NETDEV_CHANGEADDR:
 521                 if (hard_iface->if_status == IF_NOT_IN_USE)
 522                         goto hardif_put;
 523
 524                 check_known_mac_addr(hard_iface->net_dev);
 525
 526                 bat_priv = netdev_priv(hard_iface->soft_iface);
 527                 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
 528
 529                 primary_if = primary_if_get_selected(bat_priv);
 530                 if (!primary_if)
 531                         goto hardif_put;
 532
 533                 if (hard_iface == primary_if)
 534                         primary_if_update_addr(bat_priv, NULL);
 535                 break;
 536         default:
 537                 break;
 538         }
 539
 540 hardif_put:
 541         hardif_free_ref(hard_iface);
 542 out:
 543         if (primary_if)
 544                 hardif_free_ref(primary_if);
 545         return NOTIFY_DONE;
 546 }
 547
 548 /* This function returns true if the interface represented by ifindex is a
 549  * 802.11 wireless device */
 550 bool is_wifi_iface(int ifindex)
 551 {
 552         struct net_device *net_device = NULL;
 553         bool ret = false;
 554
 555         if (ifindex == NULL_IFINDEX)
 556                 goto out;
 557
 558         net_device = dev_get_by_index(&init_net, ifindex);
 559         if (!net_device)
 560                 goto out;
 561
 562 #ifdef CONFIG_WIRELESS_EXT
 563         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 564          * check for wireless_handlers != NULL */
 565         if (net_device->wireless_handlers)
 566                 ret = true;
 567         else
 568 #endif
 569                 /* cfg80211 drivers have to set ieee80211_ptr */
 570                 if (net_device->ieee80211_ptr)
 571                         ret = true;
 572 out:
 573         if (net_device)
 574                 dev_put(net_device);
 575         return ret;
 576 }
 577
 578 struct notifier_block hard_if_notifier = {
 579         .notifier_call = hard_if_event,
 580 };