net/batman-adv/main.c

   1 /* Copyright (C) 2007-2013 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 <linux/crc32c.h>
  21 #include <linux/highmem.h>
  22 #include "main.h"
  23 #include "sysfs.h"
  24 #include "debugfs.h"
  25 #include "routing.h"
  26 #include "send.h"
  27 #include "originator.h"
  28 #include "soft-interface.h"
  29 #include "icmp_socket.h"
  30 #include "translation-table.h"
  31 #include "hard-interface.h"
  32 #include "gateway_client.h"
  33 #include "bridge_loop_avoidance.h"
  34 #include "distributed-arp-table.h"
  35 #include "vis.h"
  36 #include "hash.h"
  37 #include "bat_algo.h"
  38 #include "network-coding.h"
  39
  40
  41 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  42  * list traversals just rcu-locked
  43  */
  44 struct list_head batadv_hardif_list;
  45 static int (*batadv_rx_handler[256])(struct sk_buff *,
  46                                      struct batadv_hard_iface *);
  47 char batadv_routing_algo[20] = "BATMAN_IV";
  48 static struct hlist_head batadv_algo_list;
  49
  50 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  51
  52 struct workqueue_struct *batadv_event_workqueue;
  53
  54 static void batadv_recv_handler_init(void);
  55
  56 static int __init batadv_init(void)
  57 {
  58         INIT_LIST_HEAD(&batadv_hardif_list);
  59         INIT_HLIST_HEAD(&batadv_algo_list);
  60
  61         batadv_recv_handler_init();
  62
  63         batadv_iv_init();
  64         batadv_nc_init();
  65
  66         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  67
  68         if (!batadv_event_workqueue)
  69                 return -ENOMEM;
  70
  71         batadv_socket_init();
  72         batadv_debugfs_init();
  73
  74         register_netdevice_notifier(&batadv_hard_if_notifier);
  75         rtnl_link_register(&batadv_link_ops);
  76
  77         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  78                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  79
  80         return 0;
  81 }
  82
  83 static void __exit batadv_exit(void)
  84 {
  85         batadv_debugfs_destroy();
  86         rtnl_link_unregister(&batadv_link_ops);
  87         unregister_netdevice_notifier(&batadv_hard_if_notifier);
  88         batadv_hardif_remove_interfaces();
  89
  90         flush_workqueue(batadv_event_workqueue);
  91         destroy_workqueue(batadv_event_workqueue);
  92         batadv_event_workqueue = NULL;
  93
  94         rcu_barrier();
  95 }
  96
  97 int batadv_mesh_init(struct net_device *soft_iface)
  98 {
  99         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 100         int ret;
 101
 102         spin_lock_init(&bat_priv->forw_bat_list_lock);
 103         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 104         spin_lock_init(&bat_priv->tt.changes_list_lock);
 105         spin_lock_init(&bat_priv->tt.req_list_lock);
 106         spin_lock_init(&bat_priv->tt.roam_list_lock);
 107         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 108         spin_lock_init(&bat_priv->gw.list_lock);
 109         spin_lock_init(&bat_priv->vis.hash_lock);
 110         spin_lock_init(&bat_priv->vis.list_lock);
 111
 112         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 113         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 114         INIT_HLIST_HEAD(&bat_priv->gw.list);
 115         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 116         INIT_LIST_HEAD(&bat_priv->tt.req_list);
 117         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 118
 119         ret = batadv_originator_init(bat_priv);
 120         if (ret < 0)
 121                 goto err;
 122
 123         ret = batadv_tt_init(bat_priv);
 124         if (ret < 0)
 125                 goto err;
 126
 127         batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 128                             BATADV_NULL_IFINDEX);
 129
 130         ret = batadv_vis_init(bat_priv);
 131         if (ret < 0)
 132                 goto err;
 133
 134         ret = batadv_bla_init(bat_priv);
 135         if (ret < 0)
 136                 goto err;
 137
 138         ret = batadv_dat_init(bat_priv);
 139         if (ret < 0)
 140                 goto err;
 141
 142         ret = batadv_nc_mesh_init(bat_priv);
 143         if (ret < 0)
 144                 goto err;
 145
 146         atomic_set(&bat_priv->gw.reselect, 0);
 147         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 148
 149         return 0;
 150
 151 err:
 152         batadv_mesh_free(soft_iface);
 153         return ret;
 154 }
 155
 156 void batadv_mesh_free(struct net_device *soft_iface)
 157 {
 158         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 159
 160         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 161
 162         batadv_purge_outstanding_packets(bat_priv, NULL);
 163
 164         batadv_vis_quit(bat_priv);
 165
 166         batadv_gw_node_purge(bat_priv);
 167         batadv_nc_mesh_free(bat_priv);
 168         batadv_dat_free(bat_priv);
 169         batadv_bla_free(bat_priv);
 170
 171         /* Free the TT and the originator tables only after having terminated
 172          * all the other depending components which may use these structures for
 173          * their purposes.
 174          */
 175         batadv_tt_free(bat_priv);
 176
 177         /* Since the originator table clean up routine is accessing the TT
 178          * tables as well, it has to be invoked after the TT tables have been
 179          * freed and marked as empty. This ensures that no cleanup RCU callbacks
 180          * accessing the TT data are scheduled for later execution.
 181          */
 182         batadv_originator_free(bat_priv);
 183
 184         free_percpu(bat_priv->bat_counters);
 185         bat_priv->bat_counters = NULL;
 186
 187         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 188 }
 189
 190 /**
 191  * batadv_is_my_mac - check if the given mac address belongs to any of the real
 192  * interfaces in the current mesh
 193  * @bat_priv: the bat priv with all the soft interface information
 194  * @addr: the address to check
 195  */
 196 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
 197 {
 198         const 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->if_status != BATADV_IF_ACTIVE)
 203                         continue;
 204
 205                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 206                         continue;
 207
 208                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 209                         rcu_read_unlock();
 210                         return 1;
 211                 }
 212         }
 213         rcu_read_unlock();
 214         return 0;
 215 }
 216
 217 /**
 218  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 219  *  function that requires the primary interface
 220  * @seq: debugfs table seq_file struct
 221  *
 222  * Returns primary interface if found or NULL otherwise.
 223  */
 224 struct batadv_hard_iface *
 225 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 226 {
 227         struct net_device *net_dev = (struct net_device *)seq->private;
 228         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 229         struct batadv_hard_iface *primary_if;
 230
 231         primary_if = batadv_primary_if_get_selected(bat_priv);
 232
 233         if (!primary_if) {
 234                 seq_printf(seq,
 235                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 236                            net_dev->name);
 237                 goto out;
 238         }
 239
 240         if (primary_if->if_status == BATADV_IF_ACTIVE)
 241                 goto out;
 242
 243         seq_printf(seq,
 244                    "BATMAN mesh %s disabled - primary interface not active\n",
 245                    net_dev->name);
 246         batadv_hardif_free_ref(primary_if);
 247         primary_if = NULL;
 248
 249 out:
 250         return primary_if;
 251 }
 252
 253 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 254                                         struct batadv_hard_iface *recv_if)
 255 {
 256         return NET_RX_DROP;
 257 }
 258
 259 /* incoming packets with the batman ethertype received on any active hard
 260  * interface
 261  */
 262 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 263                            struct packet_type *ptype,
 264                            struct net_device *orig_dev)
 265 {
 266         struct batadv_priv *bat_priv;
 267         struct batadv_ogm_packet *batadv_ogm_packet;
 268         struct batadv_hard_iface *hard_iface;
 269         uint8_t idx;
 270         int ret;
 271
 272         hard_iface = container_of(ptype, struct batadv_hard_iface,
 273                                   batman_adv_ptype);
 274         skb = skb_share_check(skb, GFP_ATOMIC);
 275
 276         /* skb was released by skb_share_check() */
 277         if (!skb)
 278                 goto err_out;
 279
 280         /* packet should hold at least type and version */
 281         if (unlikely(!pskb_may_pull(skb, 2)))
 282                 goto err_free;
 283
 284         /* expect a valid ethernet header here. */
 285         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 286                 goto err_free;
 287
 288         if (!hard_iface->soft_iface)
 289                 goto err_free;
 290
 291         bat_priv = netdev_priv(hard_iface->soft_iface);
 292
 293         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 294                 goto err_free;
 295
 296         /* discard frames on not active interfaces */
 297         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 298                 goto err_free;
 299
 300         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 301
 302         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 303                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 304                            "Drop packet: incompatible batman version (%i)\n",
 305                            batadv_ogm_packet->header.version);
 306                 goto err_free;
 307         }
 308
 309         /* all receive handlers return whether they received or reused
 310          * the supplied skb. if not, we have to free the skb.
 311          */
 312         idx = batadv_ogm_packet->header.packet_type;
 313         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 314
 315         if (ret == NET_RX_DROP)
 316                 kfree_skb(skb);
 317
 318         /* return NET_RX_SUCCESS in any case as we
 319          * most probably dropped the packet for
 320          * routing-logical reasons.
 321          */
 322         return NET_RX_SUCCESS;
 323
 324 err_free:
 325         kfree_skb(skb);
 326 err_out:
 327         return NET_RX_DROP;
 328 }
 329
 330 static void batadv_recv_handler_init(void)
 331 {
 332         int i;
 333
 334         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 335                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 336
 337         /* batman icmp packet */
 338         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 339         /* unicast with 4 addresses packet */
 340         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 341         /* unicast packet */
 342         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 343         /* fragmented unicast packet */
 344         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 345         /* broadcast packet */
 346         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 347         /* vis packet */
 348         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 349         /* Translation table query (request or response) */
 350         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 351         /* Roaming advertisement */
 352         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 353 }
 354
 355 int
 356 batadv_recv_handler_register(uint8_t packet_type,
 357                              int (*recv_handler)(struct sk_buff *,
 358                                                  struct batadv_hard_iface *))
 359 {
 360         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 361                 return -EBUSY;
 362
 363         batadv_rx_handler[packet_type] = recv_handler;
 364         return 0;
 365 }
 366
 367 void batadv_recv_handler_unregister(uint8_t packet_type)
 368 {
 369         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 370 }
 371
 372 static struct batadv_algo_ops *batadv_algo_get(char *name)
 373 {
 374         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 375
 376         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 377                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 378                         continue;
 379
 380                 bat_algo_ops = bat_algo_ops_tmp;
 381                 break;
 382         }
 383
 384         return bat_algo_ops;
 385 }
 386
 387 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 388 {
 389         struct batadv_algo_ops *bat_algo_ops_tmp;
 390         int ret;
 391
 392         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 393         if (bat_algo_ops_tmp) {
 394                 pr_info("Trying to register already registered routing algorithm: %s\n",
 395                         bat_algo_ops->name);
 396                 ret = -EEXIST;
 397                 goto out;
 398         }
 399
 400         /* all algorithms must implement all ops (for now) */
 401         if (!bat_algo_ops->bat_iface_enable ||
 402             !bat_algo_ops->bat_iface_disable ||
 403             !bat_algo_ops->bat_iface_update_mac ||
 404             !bat_algo_ops->bat_primary_iface_set ||
 405             !bat_algo_ops->bat_ogm_schedule ||
 406             !bat_algo_ops->bat_ogm_emit) {
 407                 pr_info("Routing algo '%s' does not implement required ops\n",
 408                         bat_algo_ops->name);
 409                 ret = -EINVAL;
 410                 goto out;
 411         }
 412
 413         INIT_HLIST_NODE(&bat_algo_ops->list);
 414         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 415         ret = 0;
 416
 417 out:
 418         return ret;
 419 }
 420
 421 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 422 {
 423         struct batadv_algo_ops *bat_algo_ops;
 424         int ret = -EINVAL;
 425
 426         bat_algo_ops = batadv_algo_get(name);
 427         if (!bat_algo_ops)
 428                 goto out;
 429
 430         bat_priv->bat_algo_ops = bat_algo_ops;
 431         ret = 0;
 432
 433 out:
 434         return ret;
 435 }
 436
 437 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 438 {
 439         struct batadv_algo_ops *bat_algo_ops;
 440
 441         seq_puts(seq, "Available routing algorithms:\n");
 442
 443         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 444                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 445         }
 446
 447         return 0;
 448 }
 449
 450 /**
 451  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 452  *  the header
 453  * @skb: skb pointing to fragmented socket buffers
 454  * @payload_ptr: Pointer to position inside the head buffer of the skb
 455  *  marking the start of the data to be CRC'ed
 456  *
 457  * payload_ptr must always point to an address in the skb head buffer and not to
 458  * a fragment.
 459  */
 460 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 461 {
 462         u32 crc = 0;
 463         unsigned int from;
 464         unsigned int to = skb->len;
 465         struct skb_seq_state st;
 466         const u8 *data;
 467         unsigned int len;
 468         unsigned int consumed = 0;
 469
 470         from = (unsigned int)(payload_ptr - skb->data);
 471
 472         skb_prepare_seq_read(skb, from, to, &st);
 473         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 474                 crc = crc32c(crc, data, len);
 475                 consumed += len;
 476         }
 477         skb_abort_seq_read(&st);
 478
 479         return htonl(crc);
 480 }
 481
 482 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 483 {
 484         struct batadv_algo_ops *bat_algo_ops;
 485         char *algo_name = (char *)val;
 486         size_t name_len = strlen(algo_name);
 487
 488         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 489                 algo_name[name_len - 1] = '\0';
 490
 491         bat_algo_ops = batadv_algo_get(algo_name);
 492         if (!bat_algo_ops) {
 493                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 494                 return -EINVAL;
 495         }
 496
 497         return param_set_copystring(algo_name, kp);
 498 }
 499
 500 static const struct kernel_param_ops batadv_param_ops_ra = {
 501         .set = batadv_param_set_ra,
 502         .get = param_get_string,
 503 };
 504
 505 static struct kparam_string batadv_param_string_ra = {
 506         .maxlen = sizeof(batadv_routing_algo),
 507         .string = batadv_routing_algo,
 508 };
 509
 510 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 511                 0644);
 512 module_init(batadv_init);
 513 module_exit(batadv_exit);
 514
 515 MODULE_LICENSE("GPL");
 516
 517 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 518 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 519 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 520 MODULE_VERSION(BATADV_SOURCE_VERSION);