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
  65         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  66
  67         if (!batadv_event_workqueue)
  68                 return -ENOMEM;
  69
  70         batadv_socket_init();
  71         batadv_debugfs_init();
  72
  73         register_netdevice_notifier(&batadv_hard_if_notifier);
  74         rtnl_link_register(&batadv_link_ops);
  75
  76         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  77                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  78
  79         return 0;
  80 }
  81
  82 static void __exit batadv_exit(void)
  83 {
  84         batadv_debugfs_destroy();
  85         rtnl_link_unregister(&batadv_link_ops);
  86         unregister_netdevice_notifier(&batadv_hard_if_notifier);
  87         batadv_hardif_remove_interfaces();
  88
  89         flush_workqueue(batadv_event_workqueue);
  90         destroy_workqueue(batadv_event_workqueue);
  91         batadv_event_workqueue = NULL;
  92
  93         rcu_barrier();
  94 }
  95
  96 int batadv_mesh_init(struct net_device *soft_iface)
  97 {
  98         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  99         int ret;
 100
 101         spin_lock_init(&bat_priv->forw_bat_list_lock);
 102         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 103         spin_lock_init(&bat_priv->tt.changes_list_lock);
 104         spin_lock_init(&bat_priv->tt.req_list_lock);
 105         spin_lock_init(&bat_priv->tt.roam_list_lock);
 106         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 107         spin_lock_init(&bat_priv->gw.list_lock);
 108         spin_lock_init(&bat_priv->vis.hash_lock);
 109         spin_lock_init(&bat_priv->vis.list_lock);
 110
 111         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 112         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 113         INIT_HLIST_HEAD(&bat_priv->gw.list);
 114         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 115         INIT_LIST_HEAD(&bat_priv->tt.req_list);
 116         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 117
 118         ret = batadv_originator_init(bat_priv);
 119         if (ret < 0)
 120                 goto err;
 121
 122         ret = batadv_tt_init(bat_priv);
 123         if (ret < 0)
 124                 goto err;
 125
 126         batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 127                             BATADV_NULL_IFINDEX);
 128
 129         ret = batadv_vis_init(bat_priv);
 130         if (ret < 0)
 131                 goto err;
 132
 133         ret = batadv_bla_init(bat_priv);
 134         if (ret < 0)
 135                 goto err;
 136
 137         ret = batadv_dat_init(bat_priv);
 138         if (ret < 0)
 139                 goto err;
 140
 141         ret = batadv_nc_init(bat_priv);
 142         if (ret < 0)
 143                 goto err;
 144
 145         atomic_set(&bat_priv->gw.reselect, 0);
 146         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 147
 148         return 0;
 149
 150 err:
 151         batadv_mesh_free(soft_iface);
 152         return ret;
 153 }
 154
 155 void batadv_mesh_free(struct net_device *soft_iface)
 156 {
 157         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 158
 159         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 160
 161         batadv_purge_outstanding_packets(bat_priv, NULL);
 162
 163         batadv_vis_quit(bat_priv);
 164
 165         batadv_gw_node_purge(bat_priv);
 166         batadv_nc_free(bat_priv);
 167         batadv_dat_free(bat_priv);
 168         batadv_bla_free(bat_priv);
 169
 170         /* Free the TT and the originator tables only after having terminated
 171          * all the other depending components which may use these structures for
 172          * their purposes.
 173          */
 174         batadv_tt_free(bat_priv);
 175
 176         /* Since the originator table clean up routine is accessing the TT
 177          * tables as well, it has to be invoked after the TT tables have been
 178          * freed and marked as empty. This ensures that no cleanup RCU callbacks
 179          * accessing the TT data are scheduled for later execution.
 180          */
 181         batadv_originator_free(bat_priv);
 182
 183         free_percpu(bat_priv->bat_counters);
 184
 185         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 186 }
 187
 188 /**
 189  * batadv_is_my_mac - check if the given mac address belongs to any of the real
 190  * interfaces in the current mesh
 191  * @bat_priv: the bat priv with all the soft interface information
 192  * @addr: the address to check
 193  */
 194 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
 195 {
 196         const struct batadv_hard_iface *hard_iface;
 197
 198         rcu_read_lock();
 199         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 200                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 201                         continue;
 202
 203                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 204                         continue;
 205
 206                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 207                         rcu_read_unlock();
 208                         return 1;
 209                 }
 210         }
 211         rcu_read_unlock();
 212         return 0;
 213 }
 214
 215 /**
 216  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 217  *  function that requires the primary interface
 218  * @seq: debugfs table seq_file struct
 219  *
 220  * Returns primary interface if found or NULL otherwise.
 221  */
 222 struct batadv_hard_iface *
 223 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 224 {
 225         struct net_device *net_dev = (struct net_device *)seq->private;
 226         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 227         struct batadv_hard_iface *primary_if;
 228
 229         primary_if = batadv_primary_if_get_selected(bat_priv);
 230
 231         if (!primary_if) {
 232                 seq_printf(seq,
 233                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 234                            net_dev->name);
 235                 goto out;
 236         }
 237
 238         if (primary_if->if_status == BATADV_IF_ACTIVE)
 239                 goto out;
 240
 241         seq_printf(seq,
 242                    "BATMAN mesh %s disabled - primary interface not active\n",
 243                    net_dev->name);
 244         batadv_hardif_free_ref(primary_if);
 245         primary_if = NULL;
 246
 247 out:
 248         return primary_if;
 249 }
 250
 251 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 252                                         struct batadv_hard_iface *recv_if)
 253 {
 254         return NET_RX_DROP;
 255 }
 256
 257 /* incoming packets with the batman ethertype received on any active hard
 258  * interface
 259  */
 260 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 261                            struct packet_type *ptype,
 262                            struct net_device *orig_dev)
 263 {
 264         struct batadv_priv *bat_priv;
 265         struct batadv_ogm_packet *batadv_ogm_packet;
 266         struct batadv_hard_iface *hard_iface;
 267         uint8_t idx;
 268         int ret;
 269
 270         hard_iface = container_of(ptype, struct batadv_hard_iface,
 271                                   batman_adv_ptype);
 272         skb = skb_share_check(skb, GFP_ATOMIC);
 273
 274         /* skb was released by skb_share_check() */
 275         if (!skb)
 276                 goto err_out;
 277
 278         /* packet should hold at least type and version */
 279         if (unlikely(!pskb_may_pull(skb, 2)))
 280                 goto err_free;
 281
 282         /* expect a valid ethernet header here. */
 283         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 284                 goto err_free;
 285
 286         if (!hard_iface->soft_iface)
 287                 goto err_free;
 288
 289         bat_priv = netdev_priv(hard_iface->soft_iface);
 290
 291         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 292                 goto err_free;
 293
 294         /* discard frames on not active interfaces */
 295         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 296                 goto err_free;
 297
 298         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 299
 300         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 301                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 302                            "Drop packet: incompatible batman version (%i)\n",
 303                            batadv_ogm_packet->header.version);
 304                 goto err_free;
 305         }
 306
 307         /* all receive handlers return whether they received or reused
 308          * the supplied skb. if not, we have to free the skb.
 309          */
 310         idx = batadv_ogm_packet->header.packet_type;
 311         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 312
 313         if (ret == NET_RX_DROP)
 314                 kfree_skb(skb);
 315
 316         /* return NET_RX_SUCCESS in any case as we
 317          * most probably dropped the packet for
 318          * routing-logical reasons.
 319          */
 320         return NET_RX_SUCCESS;
 321
 322 err_free:
 323         kfree_skb(skb);
 324 err_out:
 325         return NET_RX_DROP;
 326 }
 327
 328 static void batadv_recv_handler_init(void)
 329 {
 330         int i;
 331
 332         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 333                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 334
 335         /* batman icmp packet */
 336         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 337         /* unicast with 4 addresses packet */
 338         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 339         /* unicast packet */
 340         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 341         /* fragmented unicast packet */
 342         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 343         /* broadcast packet */
 344         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 345         /* vis packet */
 346         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 347         /* Translation table query (request or response) */
 348         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 349         /* Roaming advertisement */
 350         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 351 }
 352
 353 int
 354 batadv_recv_handler_register(uint8_t packet_type,
 355                              int (*recv_handler)(struct sk_buff *,
 356                                                  struct batadv_hard_iface *))
 357 {
 358         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 359                 return -EBUSY;
 360
 361         batadv_rx_handler[packet_type] = recv_handler;
 362         return 0;
 363 }
 364
 365 void batadv_recv_handler_unregister(uint8_t packet_type)
 366 {
 367         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 368 }
 369
 370 static struct batadv_algo_ops *batadv_algo_get(char *name)
 371 {
 372         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 373
 374         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 375                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 376                         continue;
 377
 378                 bat_algo_ops = bat_algo_ops_tmp;
 379                 break;
 380         }
 381
 382         return bat_algo_ops;
 383 }
 384
 385 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 386 {
 387         struct batadv_algo_ops *bat_algo_ops_tmp;
 388         int ret;
 389
 390         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 391         if (bat_algo_ops_tmp) {
 392                 pr_info("Trying to register already registered routing algorithm: %s\n",
 393                         bat_algo_ops->name);
 394                 ret = -EEXIST;
 395                 goto out;
 396         }
 397
 398         /* all algorithms must implement all ops (for now) */
 399         if (!bat_algo_ops->bat_iface_enable ||
 400             !bat_algo_ops->bat_iface_disable ||
 401             !bat_algo_ops->bat_iface_update_mac ||
 402             !bat_algo_ops->bat_primary_iface_set ||
 403             !bat_algo_ops->bat_ogm_schedule ||
 404             !bat_algo_ops->bat_ogm_emit) {
 405                 pr_info("Routing algo '%s' does not implement required ops\n",
 406                         bat_algo_ops->name);
 407                 ret = -EINVAL;
 408                 goto out;
 409         }
 410
 411         INIT_HLIST_NODE(&bat_algo_ops->list);
 412         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 413         ret = 0;
 414
 415 out:
 416         return ret;
 417 }
 418
 419 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 420 {
 421         struct batadv_algo_ops *bat_algo_ops;
 422         int ret = -EINVAL;
 423
 424         bat_algo_ops = batadv_algo_get(name);
 425         if (!bat_algo_ops)
 426                 goto out;
 427
 428         bat_priv->bat_algo_ops = bat_algo_ops;
 429         ret = 0;
 430
 431 out:
 432         return ret;
 433 }
 434
 435 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 436 {
 437         struct batadv_algo_ops *bat_algo_ops;
 438
 439         seq_puts(seq, "Available routing algorithms:\n");
 440
 441         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 442                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 443         }
 444
 445         return 0;
 446 }
 447
 448 /**
 449  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 450  *  the header
 451  * @skb: skb pointing to fragmented socket buffers
 452  * @payload_ptr: Pointer to position inside the head buffer of the skb
 453  *  marking the start of the data to be CRC'ed
 454  *
 455  * payload_ptr must always point to an address in the skb head buffer and not to
 456  * a fragment.
 457  */
 458 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 459 {
 460         u32 crc = 0;
 461         unsigned int from;
 462         unsigned int to = skb->len;
 463         struct skb_seq_state st;
 464         const u8 *data;
 465         unsigned int len;
 466         unsigned int consumed = 0;
 467
 468         from = (unsigned int)(payload_ptr - skb->data);
 469
 470         skb_prepare_seq_read(skb, from, to, &st);
 471         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 472                 crc = crc32c(crc, data, len);
 473                 consumed += len;
 474         }
 475         skb_abort_seq_read(&st);
 476
 477         return htonl(crc);
 478 }
 479
 480 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 481 {
 482         struct batadv_algo_ops *bat_algo_ops;
 483         char *algo_name = (char *)val;
 484         size_t name_len = strlen(algo_name);
 485
 486         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 487                 algo_name[name_len - 1] = '\0';
 488
 489         bat_algo_ops = batadv_algo_get(algo_name);
 490         if (!bat_algo_ops) {
 491                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 492                 return -EINVAL;
 493         }
 494
 495         return param_set_copystring(algo_name, kp);
 496 }
 497
 498 static const struct kernel_param_ops batadv_param_ops_ra = {
 499         .set = batadv_param_set_ra,
 500         .get = param_get_string,
 501 };
 502
 503 static struct kparam_string batadv_param_string_ra = {
 504         .maxlen = sizeof(batadv_routing_algo),
 505         .string = batadv_routing_algo,
 506 };
 507
 508 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 509                 0644);
 510 module_init(batadv_init);
 511 module_exit(batadv_exit);
 512
 513 MODULE_LICENSE("GPL");
 514
 515 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 516 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 517 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 518 MODULE_VERSION(BATADV_SOURCE_VERSION);