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_originator_free(bat_priv);
 167         batadv_nc_free(bat_priv);
 168
 169         batadv_tt_free(bat_priv);
 170
 171         batadv_bla_free(bat_priv);
 172
 173         batadv_dat_free(bat_priv);
 174
 175         free_percpu(bat_priv->bat_counters);
 176
 177         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 178 }
 179
 180 /**
 181  * batadv_is_my_mac - check if the given mac address belongs to any of the real
 182  * interfaces in the current mesh
 183  * @bat_priv: the bat priv with all the soft interface information
 184  * @addr: the address to check
 185  */
 186 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
 187 {
 188         const struct batadv_hard_iface *hard_iface;
 189
 190         rcu_read_lock();
 191         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 192                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 193                         continue;
 194
 195                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 196                         continue;
 197
 198                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 199                         rcu_read_unlock();
 200                         return 1;
 201                 }
 202         }
 203         rcu_read_unlock();
 204         return 0;
 205 }
 206
 207 /**
 208  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 209  *  function that requires the primary interface
 210  * @seq: debugfs table seq_file struct
 211  *
 212  * Returns primary interface if found or NULL otherwise.
 213  */
 214 struct batadv_hard_iface *
 215 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 216 {
 217         struct net_device *net_dev = (struct net_device *)seq->private;
 218         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 219         struct batadv_hard_iface *primary_if;
 220
 221         primary_if = batadv_primary_if_get_selected(bat_priv);
 222
 223         if (!primary_if) {
 224                 seq_printf(seq,
 225                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 226                            net_dev->name);
 227                 goto out;
 228         }
 229
 230         if (primary_if->if_status == BATADV_IF_ACTIVE)
 231                 goto out;
 232
 233         seq_printf(seq,
 234                    "BATMAN mesh %s disabled - primary interface not active\n",
 235                    net_dev->name);
 236         batadv_hardif_free_ref(primary_if);
 237         primary_if = NULL;
 238
 239 out:
 240         return primary_if;
 241 }
 242
 243 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 244                                         struct batadv_hard_iface *recv_if)
 245 {
 246         return NET_RX_DROP;
 247 }
 248
 249 /* incoming packets with the batman ethertype received on any active hard
 250  * interface
 251  */
 252 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 253                            struct packet_type *ptype,
 254                            struct net_device *orig_dev)
 255 {
 256         struct batadv_priv *bat_priv;
 257         struct batadv_ogm_packet *batadv_ogm_packet;
 258         struct batadv_hard_iface *hard_iface;
 259         uint8_t idx;
 260         int ret;
 261
 262         hard_iface = container_of(ptype, struct batadv_hard_iface,
 263                                   batman_adv_ptype);
 264         skb = skb_share_check(skb, GFP_ATOMIC);
 265
 266         /* skb was released by skb_share_check() */
 267         if (!skb)
 268                 goto err_out;
 269
 270         /* packet should hold at least type and version */
 271         if (unlikely(!pskb_may_pull(skb, 2)))
 272                 goto err_free;
 273
 274         /* expect a valid ethernet header here. */
 275         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 276                 goto err_free;
 277
 278         if (!hard_iface->soft_iface)
 279                 goto err_free;
 280
 281         bat_priv = netdev_priv(hard_iface->soft_iface);
 282
 283         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 284                 goto err_free;
 285
 286         /* discard frames on not active interfaces */
 287         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 288                 goto err_free;
 289
 290         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 291
 292         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 293                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 294                            "Drop packet: incompatible batman version (%i)\n",
 295                            batadv_ogm_packet->header.version);
 296                 goto err_free;
 297         }
 298
 299         /* all receive handlers return whether they received or reused
 300          * the supplied skb. if not, we have to free the skb.
 301          */
 302         idx = batadv_ogm_packet->header.packet_type;
 303         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 304
 305         if (ret == NET_RX_DROP)
 306                 kfree_skb(skb);
 307
 308         /* return NET_RX_SUCCESS in any case as we
 309          * most probably dropped the packet for
 310          * routing-logical reasons.
 311          */
 312         return NET_RX_SUCCESS;
 313
 314 err_free:
 315         kfree_skb(skb);
 316 err_out:
 317         return NET_RX_DROP;
 318 }
 319
 320 static void batadv_recv_handler_init(void)
 321 {
 322         int i;
 323
 324         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 325                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 326
 327         /* batman icmp packet */
 328         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 329         /* unicast with 4 addresses packet */
 330         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 331         /* unicast packet */
 332         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 333         /* fragmented unicast packet */
 334         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 335         /* broadcast packet */
 336         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 337         /* vis packet */
 338         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 339         /* Translation table query (request or response) */
 340         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 341         /* Roaming advertisement */
 342         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 343 }
 344
 345 int
 346 batadv_recv_handler_register(uint8_t packet_type,
 347                              int (*recv_handler)(struct sk_buff *,
 348                                                  struct batadv_hard_iface *))
 349 {
 350         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 351                 return -EBUSY;
 352
 353         batadv_rx_handler[packet_type] = recv_handler;
 354         return 0;
 355 }
 356
 357 void batadv_recv_handler_unregister(uint8_t packet_type)
 358 {
 359         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 360 }
 361
 362 static struct batadv_algo_ops *batadv_algo_get(char *name)
 363 {
 364         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 365
 366         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 367                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 368                         continue;
 369
 370                 bat_algo_ops = bat_algo_ops_tmp;
 371                 break;
 372         }
 373
 374         return bat_algo_ops;
 375 }
 376
 377 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 378 {
 379         struct batadv_algo_ops *bat_algo_ops_tmp;
 380         int ret;
 381
 382         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 383         if (bat_algo_ops_tmp) {
 384                 pr_info("Trying to register already registered routing algorithm: %s\n",
 385                         bat_algo_ops->name);
 386                 ret = -EEXIST;
 387                 goto out;
 388         }
 389
 390         /* all algorithms must implement all ops (for now) */
 391         if (!bat_algo_ops->bat_iface_enable ||
 392             !bat_algo_ops->bat_iface_disable ||
 393             !bat_algo_ops->bat_iface_update_mac ||
 394             !bat_algo_ops->bat_primary_iface_set ||
 395             !bat_algo_ops->bat_ogm_schedule ||
 396             !bat_algo_ops->bat_ogm_emit) {
 397                 pr_info("Routing algo '%s' does not implement required ops\n",
 398                         bat_algo_ops->name);
 399                 ret = -EINVAL;
 400                 goto out;
 401         }
 402
 403         INIT_HLIST_NODE(&bat_algo_ops->list);
 404         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 405         ret = 0;
 406
 407 out:
 408         return ret;
 409 }
 410
 411 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 412 {
 413         struct batadv_algo_ops *bat_algo_ops;
 414         int ret = -EINVAL;
 415
 416         bat_algo_ops = batadv_algo_get(name);
 417         if (!bat_algo_ops)
 418                 goto out;
 419
 420         bat_priv->bat_algo_ops = bat_algo_ops;
 421         ret = 0;
 422
 423 out:
 424         return ret;
 425 }
 426
 427 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 428 {
 429         struct batadv_algo_ops *bat_algo_ops;
 430
 431         seq_puts(seq, "Available routing algorithms:\n");
 432
 433         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 434                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 435         }
 436
 437         return 0;
 438 }
 439
 440 /**
 441  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 442  *  the header
 443  * @skb: skb pointing to fragmented socket buffers
 444  * @payload_ptr: Pointer to position inside the head buffer of the skb
 445  *  marking the start of the data to be CRC'ed
 446  *
 447  * payload_ptr must always point to an address in the skb head buffer and not to
 448  * a fragment.
 449  */
 450 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 451 {
 452         u32 crc = 0;
 453         unsigned int from;
 454         unsigned int to = skb->len;
 455         struct skb_seq_state st;
 456         const u8 *data;
 457         unsigned int len;
 458         unsigned int consumed = 0;
 459
 460         from = (unsigned int)(payload_ptr - skb->data);
 461
 462         skb_prepare_seq_read(skb, from, to, &st);
 463         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 464                 crc = crc32c(crc, data, len);
 465                 consumed += len;
 466         }
 467         skb_abort_seq_read(&st);
 468
 469         return htonl(crc);
 470 }
 471
 472 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 473 {
 474         struct batadv_algo_ops *bat_algo_ops;
 475         char *algo_name = (char *)val;
 476         size_t name_len = strlen(algo_name);
 477
 478         if (algo_name[name_len - 1] == '\n')
 479                 algo_name[name_len - 1] = '\0';
 480
 481         bat_algo_ops = batadv_algo_get(algo_name);
 482         if (!bat_algo_ops) {
 483                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 484                 return -EINVAL;
 485         }
 486
 487         return param_set_copystring(algo_name, kp);
 488 }
 489
 490 static const struct kernel_param_ops batadv_param_ops_ra = {
 491         .set = batadv_param_set_ra,
 492         .get = param_get_string,
 493 };
 494
 495 static struct kparam_string batadv_param_string_ra = {
 496         .maxlen = sizeof(batadv_routing_algo),
 497         .string = batadv_routing_algo,
 498 };
 499
 500 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 501                 0644);
 502 module_init(batadv_init);
 503 module_exit(batadv_exit);
 504
 505 MODULE_LICENSE("GPL");
 506
 507 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 508 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 509 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 510 MODULE_VERSION(BATADV_SOURCE_VERSION);