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
  39
  40 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  41  * list traversals just rcu-locked
  42  */
  43 struct list_head batadv_hardif_list;
  44 static int (*batadv_rx_handler[256])(struct sk_buff *,
  45                                      struct batadv_hard_iface *);
  46 char batadv_routing_algo[20] = "BATMAN_IV";
  47 static struct hlist_head batadv_algo_list;
  48
  49 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  50
  51 struct workqueue_struct *batadv_event_workqueue;
  52
  53 static void batadv_recv_handler_init(void);
  54
  55 static int __init batadv_init(void)
  56 {
  57         INIT_LIST_HEAD(&batadv_hardif_list);
  58         INIT_HLIST_HEAD(&batadv_algo_list);
  59
  60         batadv_recv_handler_init();
  61
  62         batadv_iv_init();
  63
  64         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  65
  66         if (!batadv_event_workqueue)
  67                 return -ENOMEM;
  68
  69         batadv_socket_init();
  70         batadv_debugfs_init();
  71
  72         register_netdevice_notifier(&batadv_hard_if_notifier);
  73
  74         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  75                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  76
  77         return 0;
  78 }
  79
  80 static void __exit batadv_exit(void)
  81 {
  82         batadv_debugfs_destroy();
  83         unregister_netdevice_notifier(&batadv_hard_if_notifier);
  84         batadv_hardif_remove_interfaces();
  85
  86         flush_workqueue(batadv_event_workqueue);
  87         destroy_workqueue(batadv_event_workqueue);
  88         batadv_event_workqueue = NULL;
  89
  90         rcu_barrier();
  91 }
  92
  93 int batadv_mesh_init(struct net_device *soft_iface)
  94 {
  95         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  96         int ret;
  97
  98         spin_lock_init(&bat_priv->forw_bat_list_lock);
  99         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 100         spin_lock_init(&bat_priv->tt.changes_list_lock);
 101         spin_lock_init(&bat_priv->tt.req_list_lock);
 102         spin_lock_init(&bat_priv->tt.roam_list_lock);
 103         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 104         spin_lock_init(&bat_priv->gw.list_lock);
 105         spin_lock_init(&bat_priv->vis.hash_lock);
 106         spin_lock_init(&bat_priv->vis.list_lock);
 107
 108         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 109         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 110         INIT_HLIST_HEAD(&bat_priv->gw.list);
 111         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 112         INIT_LIST_HEAD(&bat_priv->tt.req_list);
 113         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 114
 115         ret = batadv_originator_init(bat_priv);
 116         if (ret < 0)
 117                 goto err;
 118
 119         ret = batadv_tt_init(bat_priv);
 120         if (ret < 0)
 121                 goto err;
 122
 123         batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 124                             BATADV_NULL_IFINDEX);
 125
 126         ret = batadv_vis_init(bat_priv);
 127         if (ret < 0)
 128                 goto err;
 129
 130         ret = batadv_bla_init(bat_priv);
 131         if (ret < 0)
 132                 goto err;
 133
 134         ret = batadv_dat_init(bat_priv);
 135         if (ret < 0)
 136                 goto err;
 137
 138         atomic_set(&bat_priv->gw.reselect, 0);
 139         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 140
 141         return 0;
 142
 143 err:
 144         batadv_mesh_free(soft_iface);
 145         return ret;
 146 }
 147
 148 void batadv_mesh_free(struct net_device *soft_iface)
 149 {
 150         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 151
 152         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 153
 154         batadv_purge_outstanding_packets(bat_priv, NULL);
 155
 156         batadv_vis_quit(bat_priv);
 157
 158         batadv_gw_node_purge(bat_priv);
 159         batadv_originator_free(bat_priv);
 160
 161         batadv_tt_free(bat_priv);
 162
 163         batadv_bla_free(bat_priv);
 164
 165         batadv_dat_free(bat_priv);
 166
 167         free_percpu(bat_priv->bat_counters);
 168
 169         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 170 }
 171
 172 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
 173 {
 174         const struct batadv_hard_iface *hard_iface;
 175
 176         rcu_read_lock();
 177         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 178                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 179                         continue;
 180
 181                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 182                         continue;
 183
 184                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 185                         rcu_read_unlock();
 186                         return 1;
 187                 }
 188         }
 189         rcu_read_unlock();
 190         return 0;
 191 }
 192
 193 /**
 194  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 195  *  function that requires the primary interface
 196  * @seq: debugfs table seq_file struct
 197  *
 198  * Returns primary interface if found or NULL otherwise.
 199  */
 200 struct batadv_hard_iface *
 201 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 202 {
 203         struct net_device *net_dev = (struct net_device *)seq->private;
 204         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 205         struct batadv_hard_iface *primary_if;
 206
 207         primary_if = batadv_primary_if_get_selected(bat_priv);
 208
 209         if (!primary_if) {
 210                 seq_printf(seq,
 211                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 212                            net_dev->name);
 213                 goto out;
 214         }
 215
 216         if (primary_if->if_status == BATADV_IF_ACTIVE)
 217                 goto out;
 218
 219         seq_printf(seq,
 220                    "BATMAN mesh %s disabled - primary interface not active\n",
 221                    net_dev->name);
 222         batadv_hardif_free_ref(primary_if);
 223         primary_if = NULL;
 224
 225 out:
 226         return primary_if;
 227 }
 228
 229 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 230                                         struct batadv_hard_iface *recv_if)
 231 {
 232         return NET_RX_DROP;
 233 }
 234
 235 /* incoming packets with the batman ethertype received on any active hard
 236  * interface
 237  */
 238 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 239                            struct packet_type *ptype,
 240                            struct net_device *orig_dev)
 241 {
 242         struct batadv_priv *bat_priv;
 243         struct batadv_ogm_packet *batadv_ogm_packet;
 244         struct batadv_hard_iface *hard_iface;
 245         uint8_t idx;
 246         int ret;
 247
 248         hard_iface = container_of(ptype, struct batadv_hard_iface,
 249                                   batman_adv_ptype);
 250         skb = skb_share_check(skb, GFP_ATOMIC);
 251
 252         /* skb was released by skb_share_check() */
 253         if (!skb)
 254                 goto err_out;
 255
 256         /* packet should hold at least type and version */
 257         if (unlikely(!pskb_may_pull(skb, 2)))
 258                 goto err_free;
 259
 260         /* expect a valid ethernet header here. */
 261         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 262                 goto err_free;
 263
 264         if (!hard_iface->soft_iface)
 265                 goto err_free;
 266
 267         bat_priv = netdev_priv(hard_iface->soft_iface);
 268
 269         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 270                 goto err_free;
 271
 272         /* discard frames on not active interfaces */
 273         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 274                 goto err_free;
 275
 276         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 277
 278         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 279                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 280                            "Drop packet: incompatible batman version (%i)\n",
 281                            batadv_ogm_packet->header.version);
 282                 goto err_free;
 283         }
 284
 285         /* all receive handlers return whether they received or reused
 286          * the supplied skb. if not, we have to free the skb.
 287          */
 288         idx = batadv_ogm_packet->header.packet_type;
 289         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 290
 291         if (ret == NET_RX_DROP)
 292                 kfree_skb(skb);
 293
 294         /* return NET_RX_SUCCESS in any case as we
 295          * most probably dropped the packet for
 296          * routing-logical reasons.
 297          */
 298         return NET_RX_SUCCESS;
 299
 300 err_free:
 301         kfree_skb(skb);
 302 err_out:
 303         return NET_RX_DROP;
 304 }
 305
 306 static void batadv_recv_handler_init(void)
 307 {
 308         int i;
 309
 310         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 311                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 312
 313         /* batman icmp packet */
 314         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 315         /* unicast with 4 addresses packet */
 316         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 317         /* unicast packet */
 318         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 319         /* fragmented unicast packet */
 320         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 321         /* broadcast packet */
 322         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 323         /* vis packet */
 324         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 325         /* Translation table query (request or response) */
 326         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 327         /* Roaming advertisement */
 328         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 329 }
 330
 331 int
 332 batadv_recv_handler_register(uint8_t packet_type,
 333                              int (*recv_handler)(struct sk_buff *,
 334                                                  struct batadv_hard_iface *))
 335 {
 336         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 337                 return -EBUSY;
 338
 339         batadv_rx_handler[packet_type] = recv_handler;
 340         return 0;
 341 }
 342
 343 void batadv_recv_handler_unregister(uint8_t packet_type)
 344 {
 345         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 346 }
 347
 348 static struct batadv_algo_ops *batadv_algo_get(char *name)
 349 {
 350         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 351
 352         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 353                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 354                         continue;
 355
 356                 bat_algo_ops = bat_algo_ops_tmp;
 357                 break;
 358         }
 359
 360         return bat_algo_ops;
 361 }
 362
 363 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 364 {
 365         struct batadv_algo_ops *bat_algo_ops_tmp;
 366         int ret;
 367
 368         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 369         if (bat_algo_ops_tmp) {
 370                 pr_info("Trying to register already registered routing algorithm: %s\n",
 371                         bat_algo_ops->name);
 372                 ret = -EEXIST;
 373                 goto out;
 374         }
 375
 376         /* all algorithms must implement all ops (for now) */
 377         if (!bat_algo_ops->bat_iface_enable ||
 378             !bat_algo_ops->bat_iface_disable ||
 379             !bat_algo_ops->bat_iface_update_mac ||
 380             !bat_algo_ops->bat_primary_iface_set ||
 381             !bat_algo_ops->bat_ogm_schedule ||
 382             !bat_algo_ops->bat_ogm_emit) {
 383                 pr_info("Routing algo '%s' does not implement required ops\n",
 384                         bat_algo_ops->name);
 385                 ret = -EINVAL;
 386                 goto out;
 387         }
 388
 389         INIT_HLIST_NODE(&bat_algo_ops->list);
 390         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 391         ret = 0;
 392
 393 out:
 394         return ret;
 395 }
 396
 397 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 398 {
 399         struct batadv_algo_ops *bat_algo_ops;
 400         int ret = -EINVAL;
 401
 402         bat_algo_ops = batadv_algo_get(name);
 403         if (!bat_algo_ops)
 404                 goto out;
 405
 406         bat_priv->bat_algo_ops = bat_algo_ops;
 407         ret = 0;
 408
 409 out:
 410         return ret;
 411 }
 412
 413 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 414 {
 415         struct batadv_algo_ops *bat_algo_ops;
 416
 417         seq_printf(seq, "Available routing algorithms:\n");
 418
 419         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 420                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 421         }
 422
 423         return 0;
 424 }
 425
 426 /**
 427  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 428  *  the header
 429  * @skb: skb pointing to fragmented socket buffers
 430  * @payload_ptr: Pointer to position inside the head buffer of the skb
 431  *  marking the start of the data to be CRC'ed
 432  *
 433  * payload_ptr must always point to an address in the skb head buffer and not to
 434  * a fragment.
 435  */
 436 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 437 {
 438         u32 crc = 0;
 439         unsigned int from;
 440         unsigned int to = skb->len;
 441         struct skb_seq_state st;
 442         const u8 *data;
 443         unsigned int len;
 444         unsigned int consumed = 0;
 445
 446         from = (unsigned int)(payload_ptr - skb->data);
 447
 448         skb_prepare_seq_read(skb, from, to, &st);
 449         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 450                 crc = crc32c(crc, data, len);
 451                 consumed += len;
 452         }
 453         skb_abort_seq_read(&st);
 454
 455         return htonl(crc);
 456 }
 457
 458 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 459 {
 460         struct batadv_algo_ops *bat_algo_ops;
 461         char *algo_name = (char *)val;
 462         size_t name_len = strlen(algo_name);
 463
 464         if (algo_name[name_len - 1] == '\n')
 465                 algo_name[name_len - 1] = '\0';
 466
 467         bat_algo_ops = batadv_algo_get(algo_name);
 468         if (!bat_algo_ops) {
 469                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 470                 return -EINVAL;
 471         }
 472
 473         return param_set_copystring(algo_name, kp);
 474 }
 475
 476 static const struct kernel_param_ops batadv_param_ops_ra = {
 477         .set = batadv_param_set_ra,
 478         .get = param_get_string,
 479 };
 480
 481 static struct kparam_string batadv_param_string_ra = {
 482         .maxlen = sizeof(batadv_routing_algo),
 483         .string = batadv_routing_algo,
 484 };
 485
 486 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 487                 0644);
 488 module_init(batadv_init);
 489 module_exit(batadv_exit);
 490
 491 MODULE_LICENSE("GPL");
 492
 493 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 494 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 495 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 496 MODULE_VERSION(BATADV_SOURCE_VERSION);