net/batman-adv/vis.c

   1 /* Copyright (C) 2008-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * 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 "main.h"
  21 #include "send.h"
  22 #include "translation-table.h"
  23 #include "vis.h"
  24 #include "soft-interface.h"
  25 #include "hard-interface.h"
  26 #include "hash.h"
  27 #include "originator.h"
  28
  29 #define BATADV_MAX_VIS_PACKET_SIZE 1000
  30
  31 static void batadv_start_vis_timer(struct bat_priv *bat_priv);
  32
  33 /* free the info */
  34 static void batadv_free_info(struct kref *ref)
  35 {
  36         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  37         struct bat_priv *bat_priv = info->bat_priv;
  38         struct recvlist_node *entry, *tmp;
  39
  40         list_del_init(&info->send_list);
  41         spin_lock_bh(&bat_priv->vis_list_lock);
  42         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  43                 list_del(&entry->list);
  44                 kfree(entry);
  45         }
  46
  47         spin_unlock_bh(&bat_priv->vis_list_lock);
  48         kfree_skb(info->skb_packet);
  49         kfree(info);
  50 }
  51
  52 /* Compare two vis packets, used by the hashing algorithm */
  53 static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
  54 {
  55         const struct vis_info *d1, *d2;
  56         const struct vis_packet *p1, *p2;
  57
  58         d1 = container_of(node, struct vis_info, hash_entry);
  59         d2 = data2;
  60         p1 = (struct vis_packet *)d1->skb_packet->data;
  61         p2 = (struct vis_packet *)d2->skb_packet->data;
  62         return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
  63 }
  64
  65 /* hash function to choose an entry in a hash table of given size
  66  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  67  */
  68 static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
  69 {
  70         const struct vis_info *vis_info = data;
  71         const struct vis_packet *packet;
  72         const unsigned char *key;
  73         uint32_t hash = 0;
  74         size_t i;
  75
  76         packet = (struct vis_packet *)vis_info->skb_packet->data;
  77         key = packet->vis_orig;
  78         for (i = 0; i < ETH_ALEN; i++) {
  79                 hash += key[i];
  80                 hash += (hash << 10);
  81                 hash ^= (hash >> 6);
  82         }
  83
  84         hash += (hash << 3);
  85         hash ^= (hash >> 11);
  86         hash += (hash << 15);
  87
  88         return hash % size;
  89 }
  90
  91 static struct vis_info *batadv_vis_hash_find(struct bat_priv *bat_priv,
  92                                              const void *data)
  93 {
  94         struct hashtable_t *hash = bat_priv->vis_hash;
  95         struct hlist_head *head;
  96         struct hlist_node *node;
  97         struct vis_info *vis_info, *vis_info_tmp = NULL;
  98         uint32_t index;
  99
 100         if (!hash)
 101                 return NULL;
 102
 103         index = batadv_vis_info_choose(data, hash->size);
 104         head = &hash->table[index];
 105
 106         rcu_read_lock();
 107         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 108                 if (!batadv_vis_info_cmp(node, data))
 109                         continue;
 110
 111                 vis_info_tmp = vis_info;
 112                 break;
 113         }
 114         rcu_read_unlock();
 115
 116         return vis_info_tmp;
 117 }
 118
 119 /* insert interface to the list of interfaces of one originator, if it
 120  * does not already exist in the list
 121  */
 122 static void batadv_vis_data_insert_interface(const uint8_t *interface,
 123                                              struct hlist_head *if_list,
 124                                              bool primary)
 125 {
 126         struct if_list_entry *entry;
 127         struct hlist_node *pos;
 128
 129         hlist_for_each_entry(entry, pos, if_list, list) {
 130                 if (batadv_compare_eth(entry->addr, interface))
 131                         return;
 132         }
 133
 134         /* it's a new address, add it to the list */
 135         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 136         if (!entry)
 137                 return;
 138         memcpy(entry->addr, interface, ETH_ALEN);
 139         entry->primary = primary;
 140         hlist_add_head(&entry->list, if_list);
 141 }
 142
 143 static void batadv_vis_data_read_prim_sec(struct seq_file *seq,
 144                                           const struct hlist_head *if_list)
 145 {
 146         struct if_list_entry *entry;
 147         struct hlist_node *pos;
 148
 149         hlist_for_each_entry(entry, pos, if_list, list) {
 150                 if (entry->primary)
 151                         seq_printf(seq, "PRIMARY, ");
 152                 else
 153                         seq_printf(seq,  "SEC %pM, ", entry->addr);
 154         }
 155 }
 156
 157 /* read an entry  */
 158 static ssize_t batadv_vis_data_read_entry(struct seq_file *seq,
 159                                           const struct vis_info_entry *entry,
 160                                           const uint8_t *src, bool primary)
 161 {
 162         if (primary && entry->quality == 0)
 163                 return seq_printf(seq, "TT %pM, ", entry->dest);
 164         else if (batadv_compare_eth(entry->src, src))
 165                 return seq_printf(seq, "TQ %pM %d, ", entry->dest,
 166                                   entry->quality);
 167
 168         return 0;
 169 }
 170
 171 static void batadv_vis_data_insert_interfaces(struct hlist_head *list,
 172                                               struct vis_packet *packet,
 173                                               struct vis_info_entry *entries)
 174 {
 175         int i;
 176
 177         for (i = 0; i < packet->entries; i++) {
 178                 if (entries[i].quality == 0)
 179                         continue;
 180
 181                 if (batadv_compare_eth(entries[i].src, packet->vis_orig))
 182                         continue;
 183
 184                 batadv_vis_data_insert_interface(entries[i].src, list, false);
 185         }
 186 }
 187
 188 static void batadv_vis_data_read_entries(struct seq_file *seq,
 189                                          struct hlist_head *list,
 190                                          struct vis_packet *packet,
 191                                          struct vis_info_entry *entries)
 192 {
 193         int i;
 194         struct if_list_entry *entry;
 195         struct hlist_node *pos;
 196
 197         hlist_for_each_entry(entry, pos, list, list) {
 198                 seq_printf(seq, "%pM,", entry->addr);
 199
 200                 for (i = 0; i < packet->entries; i++)
 201                         batadv_vis_data_read_entry(seq, &entries[i],
 202                                                    entry->addr, entry->primary);
 203
 204                 /* add primary/secondary records */
 205                 if (batadv_compare_eth(entry->addr, packet->vis_orig))
 206                         batadv_vis_data_read_prim_sec(seq, list);
 207
 208                 seq_printf(seq, "\n");
 209         }
 210 }
 211
 212 static void batadv_vis_seq_print_text_bucket(struct seq_file *seq,
 213                                              const struct hlist_head *head)
 214 {
 215         struct hlist_node *node;
 216         struct vis_info *info;
 217         struct vis_packet *packet;
 218         uint8_t *entries_pos;
 219         struct vis_info_entry *entries;
 220         struct if_list_entry *entry;
 221         struct hlist_node *pos, *n;
 222
 223         HLIST_HEAD(vis_if_list);
 224
 225         hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 226                 packet = (struct vis_packet *)info->skb_packet->data;
 227                 entries_pos = (uint8_t *)packet + sizeof(*packet);
 228                 entries = (struct vis_info_entry *)entries_pos;
 229
 230                 batadv_vis_data_insert_interface(packet->vis_orig, &vis_if_list,
 231                                                  true);
 232                 batadv_vis_data_insert_interfaces(&vis_if_list, packet,
 233                                                   entries);
 234                 batadv_vis_data_read_entries(seq, &vis_if_list, packet,
 235                                              entries);
 236
 237                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 238                         hlist_del(&entry->list);
 239                         kfree(entry);
 240                 }
 241         }
 242 }
 243
 244 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 245 {
 246         struct hard_iface *primary_if;
 247         struct hlist_head *head;
 248         struct net_device *net_dev = (struct net_device *)seq->private;
 249         struct bat_priv *bat_priv = netdev_priv(net_dev);
 250         struct hashtable_t *hash = bat_priv->vis_hash;
 251         uint32_t i;
 252         int ret = 0;
 253         int vis_server = atomic_read(&bat_priv->vis_mode);
 254
 255         primary_if = batadv_primary_if_get_selected(bat_priv);
 256         if (!primary_if)
 257                 goto out;
 258
 259         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 260                 goto out;
 261
 262         spin_lock_bh(&bat_priv->vis_hash_lock);
 263         for (i = 0; i < hash->size; i++) {
 264                 head = &hash->table[i];
 265                 batadv_vis_seq_print_text_bucket(seq, head);
 266         }
 267         spin_unlock_bh(&bat_priv->vis_hash_lock);
 268
 269 out:
 270         if (primary_if)
 271                 batadv_hardif_free_ref(primary_if);
 272         return ret;
 273 }
 274
 275 /* add the info packet to the send list, if it was not
 276  * already linked in.
 277  */
 278 static void batadv_send_list_add(struct bat_priv *bat_priv,
 279                                  struct vis_info *info)
 280 {
 281         if (list_empty(&info->send_list)) {
 282                 kref_get(&info->refcount);
 283                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 284         }
 285 }
 286
 287 /* delete the info packet from the send list, if it was
 288  * linked in.
 289  */
 290 static void batadv_send_list_del(struct vis_info *info)
 291 {
 292         if (!list_empty(&info->send_list)) {
 293                 list_del_init(&info->send_list);
 294                 kref_put(&info->refcount, batadv_free_info);
 295         }
 296 }
 297
 298 /* tries to add one entry to the receive list. */
 299 static void batadv_recv_list_add(struct bat_priv *bat_priv,
 300                                  struct list_head *recv_list, const char *mac)
 301 {
 302         struct recvlist_node *entry;
 303
 304         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 305         if (!entry)
 306                 return;
 307
 308         memcpy(entry->mac, mac, ETH_ALEN);
 309         spin_lock_bh(&bat_priv->vis_list_lock);
 310         list_add_tail(&entry->list, recv_list);
 311         spin_unlock_bh(&bat_priv->vis_list_lock);
 312 }
 313
 314 /* returns 1 if this mac is in the recv_list */
 315 static int batadv_recv_list_is_in(struct bat_priv *bat_priv,
 316                                   const struct list_head *recv_list,
 317                                   const char *mac)
 318 {
 319         const struct recvlist_node *entry;
 320
 321         spin_lock_bh(&bat_priv->vis_list_lock);
 322         list_for_each_entry(entry, recv_list, list) {
 323                 if (batadv_compare_eth(entry->mac, mac)) {
 324                         spin_unlock_bh(&bat_priv->vis_list_lock);
 325                         return 1;
 326                 }
 327         }
 328         spin_unlock_bh(&bat_priv->vis_list_lock);
 329         return 0;
 330 }
 331
 332 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 333  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 334  * is newer than old entries in the hash.
 335  */
 336 static struct vis_info *batadv_add_packet(struct bat_priv *bat_priv,
 337                                           struct vis_packet *vis_packet,
 338                                           int vis_info_len, int *is_new,
 339                                           int make_broadcast)
 340 {
 341         struct vis_info *info, *old_info;
 342         struct vis_packet *search_packet, *old_packet;
 343         struct vis_info search_elem;
 344         struct vis_packet *packet;
 345         int hash_added;
 346
 347         *is_new = 0;
 348         /* sanity check */
 349         if (!bat_priv->vis_hash)
 350                 return NULL;
 351
 352         /* see if the packet is already in vis_hash */
 353         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 354         if (!search_elem.skb_packet)
 355                 return NULL;
 356         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 357                                                      sizeof(*search_packet));
 358
 359         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 360         old_info = batadv_vis_hash_find(bat_priv, &search_elem);
 361         kfree_skb(search_elem.skb_packet);
 362
 363         if (old_info) {
 364                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 365                 if (!batadv_seq_after(ntohl(vis_packet->seqno),
 366                                       ntohl(old_packet->seqno))) {
 367                         if (old_packet->seqno == vis_packet->seqno) {
 368                                 batadv_recv_list_add(bat_priv,
 369                                                      &old_info->recv_list,
 370                                                      vis_packet->sender_orig);
 371                                 return old_info;
 372                         } else {
 373                                 /* newer packet is already in hash. */
 374                                 return NULL;
 375                         }
 376                 }
 377                 /* remove old entry */
 378                 batadv_hash_remove(bat_priv->vis_hash, batadv_vis_info_cmp,
 379                                    batadv_vis_info_choose, old_info);
 380                 batadv_send_list_del(old_info);
 381                 kref_put(&old_info->refcount, batadv_free_info);
 382         }
 383
 384         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 385         if (!info)
 386                 return NULL;
 387
 388         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 389                                          ETH_HLEN);
 390         if (!info->skb_packet) {
 391                 kfree(info);
 392                 return NULL;
 393         }
 394         skb_reserve(info->skb_packet, ETH_HLEN);
 395         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 396                                               + vis_info_len);
 397
 398         kref_init(&info->refcount);
 399         INIT_LIST_HEAD(&info->send_list);
 400         INIT_LIST_HEAD(&info->recv_list);
 401         info->first_seen = jiffies;
 402         info->bat_priv = bat_priv;
 403         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 404
 405         /* initialize and add new packet. */
 406         *is_new = 1;
 407
 408         /* Make it a broadcast packet, if required */
 409         if (make_broadcast)
 410                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 411
 412         /* repair if entries is longer than packet. */
 413         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 414                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 415
 416         batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 417
 418         /* try to add it */
 419         hash_added = batadv_hash_add(bat_priv->vis_hash, batadv_vis_info_cmp,
 420                                      batadv_vis_info_choose, info,
 421                                      &info->hash_entry);
 422         if (hash_added != 0) {
 423                 /* did not work (for some reason) */
 424                 kref_put(&info->refcount, batadv_free_info);
 425                 info = NULL;
 426         }
 427
 428         return info;
 429 }
 430
 431 /* handle the server sync packet, forward if needed. */
 432 void batadv_receive_server_sync_packet(struct bat_priv *bat_priv,
 433                                        struct vis_packet *vis_packet,
 434                                        int vis_info_len)
 435 {
 436         struct vis_info *info;
 437         int is_new, make_broadcast;
 438         int vis_server = atomic_read(&bat_priv->vis_mode);
 439
 440         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 441
 442         spin_lock_bh(&bat_priv->vis_hash_lock);
 443         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 444                                  &is_new, make_broadcast);
 445         if (!info)
 446                 goto end;
 447
 448         /* only if we are server ourselves and packet is newer than the one in
 449          * hash.
 450          */
 451         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 452                 batadv_send_list_add(bat_priv, info);
 453 end:
 454         spin_unlock_bh(&bat_priv->vis_hash_lock);
 455 }
 456
 457 /* handle an incoming client update packet and schedule forward if needed. */
 458 void batadv_receive_client_update_packet(struct bat_priv *bat_priv,
 459                                          struct vis_packet *vis_packet,
 460                                          int vis_info_len)
 461 {
 462         struct vis_info *info;
 463         struct vis_packet *packet;
 464         int is_new;
 465         int vis_server = atomic_read(&bat_priv->vis_mode);
 466         int are_target = 0;
 467
 468         /* clients shall not broadcast. */
 469         if (is_broadcast_ether_addr(vis_packet->target_orig))
 470                 return;
 471
 472         /* Are we the target for this VIS packet? */
 473         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 474             batadv_is_my_mac(vis_packet->target_orig))
 475                 are_target = 1;
 476
 477         spin_lock_bh(&bat_priv->vis_hash_lock);
 478         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 479                                  &is_new, are_target);
 480
 481         if (!info)
 482                 goto end;
 483         /* note that outdated packets will be dropped at this point. */
 484
 485         packet = (struct vis_packet *)info->skb_packet->data;
 486
 487         /* send only if we're the target server or ... */
 488         if (are_target && is_new) {
 489                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 490                 batadv_send_list_add(bat_priv, info);
 491
 492                 /* ... we're not the recipient (and thus need to forward). */
 493         } else if (!batadv_is_my_mac(packet->target_orig)) {
 494                 batadv_send_list_add(bat_priv, info);
 495         }
 496
 497 end:
 498         spin_unlock_bh(&bat_priv->vis_hash_lock);
 499 }
 500
 501 /* Walk the originators and find the VIS server with the best tq. Set the packet
 502  * address to its address and return the best_tq.
 503  *
 504  * Must be called with the originator hash locked
 505  */
 506 static int batadv_find_best_vis_server(struct bat_priv *bat_priv,
 507                                        struct vis_info *info)
 508 {
 509         struct hashtable_t *hash = bat_priv->orig_hash;
 510         struct neigh_node *router;
 511         struct hlist_node *node;
 512         struct hlist_head *head;
 513         struct orig_node *orig_node;
 514         struct vis_packet *packet;
 515         int best_tq = -1;
 516         uint32_t i;
 517
 518         packet = (struct vis_packet *)info->skb_packet->data;
 519
 520         for (i = 0; i < hash->size; i++) {
 521                 head = &hash->table[i];
 522
 523                 rcu_read_lock();
 524                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 525                         router = batadv_orig_node_get_router(orig_node);
 526                         if (!router)
 527                                 continue;
 528
 529                         if ((orig_node->flags & VIS_SERVER) &&
 530                             (router->tq_avg > best_tq)) {
 531                                 best_tq = router->tq_avg;
 532                                 memcpy(packet->target_orig, orig_node->orig,
 533                                        ETH_ALEN);
 534                         }
 535                         batadv_neigh_node_free_ref(router);
 536                 }
 537                 rcu_read_unlock();
 538         }
 539
 540         return best_tq;
 541 }
 542
 543 /* Return true if the vis packet is full. */
 544 static bool batadv_vis_packet_full(const struct vis_info *info)
 545 {
 546         const struct vis_packet *packet;
 547         size_t num_items;
 548
 549         packet = (struct vis_packet *)info->skb_packet->data;
 550         num_items = BATADV_MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry);
 551
 552         if (num_items < packet->entries + 1)
 553                 return true;
 554         return false;
 555 }
 556
 557 /* generates a packet of own vis data,
 558  * returns 0 on success, -1 if no packet could be generated
 559  */
 560 static int batadv_generate_vis_packet(struct bat_priv *bat_priv)
 561 {
 562         struct hashtable_t *hash = bat_priv->orig_hash;
 563         struct hlist_node *node;
 564         struct hlist_head *head;
 565         struct orig_node *orig_node;
 566         struct neigh_node *router;
 567         struct vis_info *info = bat_priv->my_vis_info;
 568         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 569         struct vis_info_entry *entry;
 570         struct tt_common_entry *tt_common_entry;
 571         int best_tq = -1;
 572         uint32_t i;
 573
 574         info->first_seen = jiffies;
 575         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 576
 577         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 578         packet->header.ttl = BATADV_TTL;
 579         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 580         packet->entries = 0;
 581         skb_trim(info->skb_packet, sizeof(*packet));
 582
 583         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 584                 best_tq = batadv_find_best_vis_server(bat_priv, info);
 585
 586                 if (best_tq < 0)
 587                         return best_tq;
 588         }
 589
 590         for (i = 0; i < hash->size; i++) {
 591                 head = &hash->table[i];
 592
 593                 rcu_read_lock();
 594                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 595                         router = batadv_orig_node_get_router(orig_node);
 596                         if (!router)
 597                                 continue;
 598
 599                         if (!batadv_compare_eth(router->addr, orig_node->orig))
 600                                 goto next;
 601
 602                         if (router->if_incoming->if_status != BATADV_IF_ACTIVE)
 603                                 goto next;
 604
 605                         if (router->tq_avg < 1)
 606                                 goto next;
 607
 608                         /* fill one entry into buffer. */
 609                         entry = (struct vis_info_entry *)
 610                                       skb_put(info->skb_packet, sizeof(*entry));
 611                         memcpy(entry->src,
 612                                router->if_incoming->net_dev->dev_addr,
 613                                ETH_ALEN);
 614                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 615                         entry->quality = router->tq_avg;
 616                         packet->entries++;
 617
 618 next:
 619                         batadv_neigh_node_free_ref(router);
 620
 621                         if (batadv_vis_packet_full(info))
 622                                 goto unlock;
 623                 }
 624                 rcu_read_unlock();
 625         }
 626
 627         hash = bat_priv->tt_local_hash;
 628
 629         for (i = 0; i < hash->size; i++) {
 630                 head = &hash->table[i];
 631
 632                 rcu_read_lock();
 633                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 634                                          hash_entry) {
 635                         entry = (struct vis_info_entry *)
 636                                         skb_put(info->skb_packet,
 637                                                 sizeof(*entry));
 638                         memset(entry->src, 0, ETH_ALEN);
 639                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 640                         entry->quality = 0; /* 0 means TT */
 641                         packet->entries++;
 642
 643                         if (batadv_vis_packet_full(info))
 644                                 goto unlock;
 645                 }
 646                 rcu_read_unlock();
 647         }
 648
 649         return 0;
 650
 651 unlock:
 652         rcu_read_unlock();
 653         return 0;
 654 }
 655
 656 /* free old vis packets. Must be called with this vis_hash_lock
 657  * held
 658  */
 659 static void batadv_purge_vis_packets(struct bat_priv *bat_priv)
 660 {
 661         uint32_t i;
 662         struct hashtable_t *hash = bat_priv->vis_hash;
 663         struct hlist_node *node, *node_tmp;
 664         struct hlist_head *head;
 665         struct vis_info *info;
 666
 667         for (i = 0; i < hash->size; i++) {
 668                 head = &hash->table[i];
 669
 670                 hlist_for_each_entry_safe(info, node, node_tmp,
 671                                           head, hash_entry) {
 672                         /* never purge own data. */
 673                         if (info == bat_priv->my_vis_info)
 674                                 continue;
 675
 676                         if (batadv_has_timed_out(info->first_seen,
 677                                                  BATADV_VIS_TIMEOUT)) {
 678                                 hlist_del(node);
 679                                 batadv_send_list_del(info);
 680                                 kref_put(&info->refcount, batadv_free_info);
 681                         }
 682                 }
 683         }
 684 }
 685
 686 static void batadv_broadcast_vis_packet(struct bat_priv *bat_priv,
 687                                         struct vis_info *info)
 688 {
 689         struct neigh_node *router;
 690         struct hashtable_t *hash = bat_priv->orig_hash;
 691         struct hlist_node *node;
 692         struct hlist_head *head;
 693         struct orig_node *orig_node;
 694         struct vis_packet *packet;
 695         struct sk_buff *skb;
 696         struct hard_iface *hard_iface;
 697         uint8_t dstaddr[ETH_ALEN];
 698         uint32_t i;
 699
 700
 701         packet = (struct vis_packet *)info->skb_packet->data;
 702
 703         /* send to all routers in range. */
 704         for (i = 0; i < hash->size; i++) {
 705                 head = &hash->table[i];
 706
 707                 rcu_read_lock();
 708                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 709                         /* if it's a vis server and reachable, send it. */
 710                         if (!(orig_node->flags & VIS_SERVER))
 711                                 continue;
 712
 713                         router = batadv_orig_node_get_router(orig_node);
 714                         if (!router)
 715                                 continue;
 716
 717                         /* don't send it if we already received the packet from
 718                          * this node.
 719                          */
 720                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
 721                                                    orig_node->orig)) {
 722                                 batadv_neigh_node_free_ref(router);
 723                                 continue;
 724                         }
 725
 726                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 727                         hard_iface = router->if_incoming;
 728                         memcpy(dstaddr, router->addr, ETH_ALEN);
 729
 730                         batadv_neigh_node_free_ref(router);
 731
 732                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 733                         if (skb)
 734                                 batadv_send_skb_packet(skb, hard_iface,
 735                                                        dstaddr);
 736
 737                 }
 738                 rcu_read_unlock();
 739         }
 740 }
 741
 742 static void batadv_unicast_vis_packet(struct bat_priv *bat_priv,
 743                                       struct vis_info *info)
 744 {
 745         struct orig_node *orig_node;
 746         struct neigh_node *router = NULL;
 747         struct sk_buff *skb;
 748         struct vis_packet *packet;
 749
 750         packet = (struct vis_packet *)info->skb_packet->data;
 751
 752         orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
 753         if (!orig_node)
 754                 goto out;
 755
 756         router = batadv_orig_node_get_router(orig_node);
 757         if (!router)
 758                 goto out;
 759
 760         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 761         if (skb)
 762                 batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 763
 764 out:
 765         if (router)
 766                 batadv_neigh_node_free_ref(router);
 767         if (orig_node)
 768                 batadv_orig_node_free_ref(orig_node);
 769 }
 770
 771 /* only send one vis packet. called from batadv_send_vis_packets() */
 772 static void batadv_send_vis_packet(struct bat_priv *bat_priv,
 773                                    struct vis_info *info)
 774 {
 775         struct hard_iface *primary_if;
 776         struct vis_packet *packet;
 777
 778         primary_if = batadv_primary_if_get_selected(bat_priv);
 779         if (!primary_if)
 780                 goto out;
 781
 782         packet = (struct vis_packet *)info->skb_packet->data;
 783         if (packet->header.ttl < 2) {
 784                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 785                 goto out;
 786         }
 787
 788         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 789         packet->header.ttl--;
 790
 791         if (is_broadcast_ether_addr(packet->target_orig))
 792                 batadv_broadcast_vis_packet(bat_priv, info);
 793         else
 794                 batadv_unicast_vis_packet(bat_priv, info);
 795         packet->header.ttl++; /* restore TTL */
 796
 797 out:
 798         if (primary_if)
 799                 batadv_hardif_free_ref(primary_if);
 800 }
 801
 802 /* called from timer; send (and maybe generate) vis packet. */
 803 static void batadv_send_vis_packets(struct work_struct *work)
 804 {
 805         struct delayed_work *delayed_work =
 806                 container_of(work, struct delayed_work, work);
 807         struct bat_priv *bat_priv =
 808                 container_of(delayed_work, struct bat_priv, vis_work);
 809         struct vis_info *info;
 810
 811         spin_lock_bh(&bat_priv->vis_hash_lock);
 812         batadv_purge_vis_packets(bat_priv);
 813
 814         if (batadv_generate_vis_packet(bat_priv) == 0) {
 815                 /* schedule if generation was successful */
 816                 batadv_send_list_add(bat_priv, bat_priv->my_vis_info);
 817         }
 818
 819         while (!list_empty(&bat_priv->vis_send_list)) {
 820                 info = list_first_entry(&bat_priv->vis_send_list,
 821                                         typeof(*info), send_list);
 822
 823                 kref_get(&info->refcount);
 824                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 825
 826                 batadv_send_vis_packet(bat_priv, info);
 827
 828                 spin_lock_bh(&bat_priv->vis_hash_lock);
 829                 batadv_send_list_del(info);
 830                 kref_put(&info->refcount, batadv_free_info);
 831         }
 832         spin_unlock_bh(&bat_priv->vis_hash_lock);
 833         batadv_start_vis_timer(bat_priv);
 834 }
 835
 836 /* init the vis server. this may only be called when if_list is already
 837  * initialized (e.g. bat0 is initialized, interfaces have been added)
 838  */
 839 int batadv_vis_init(struct bat_priv *bat_priv)
 840 {
 841         struct vis_packet *packet;
 842         int hash_added;
 843         unsigned int len;
 844         unsigned long first_seen;
 845
 846         if (bat_priv->vis_hash)
 847                 return 0;
 848
 849         spin_lock_bh(&bat_priv->vis_hash_lock);
 850
 851         bat_priv->vis_hash = batadv_hash_new(256);
 852         if (!bat_priv->vis_hash) {
 853                 pr_err("Can't initialize vis_hash\n");
 854                 goto err;
 855         }
 856
 857         bat_priv->my_vis_info = kmalloc(BATADV_MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 858         if (!bat_priv->my_vis_info)
 859                 goto err;
 860
 861         len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE + ETH_HLEN;
 862         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(len);
 863         if (!bat_priv->my_vis_info->skb_packet)
 864                 goto free_info;
 865
 866         skb_reserve(bat_priv->my_vis_info->skb_packet, ETH_HLEN);
 867         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 868                                               sizeof(*packet));
 869
 870         /* prefill the vis info */
 871         first_seen = jiffies - msecs_to_jiffies(BATADV_VIS_INTERVAL);
 872         bat_priv->my_vis_info->first_seen = first_seen;
 873         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 874         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 875         kref_init(&bat_priv->my_vis_info->refcount);
 876         bat_priv->my_vis_info->bat_priv = bat_priv;
 877         packet->header.version = BATADV_COMPAT_VERSION;
 878         packet->header.packet_type = BAT_VIS;
 879         packet->header.ttl = BATADV_TTL;
 880         packet->seqno = 0;
 881         packet->entries = 0;
 882
 883         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 884
 885         hash_added = batadv_hash_add(bat_priv->vis_hash, batadv_vis_info_cmp,
 886                                      batadv_vis_info_choose,
 887                                      bat_priv->my_vis_info,
 888                                      &bat_priv->my_vis_info->hash_entry);
 889         if (hash_added != 0) {
 890                 pr_err("Can't add own vis packet into hash\n");
 891                 /* not in hash, need to remove it manually. */
 892                 kref_put(&bat_priv->my_vis_info->refcount, batadv_free_info);
 893                 goto err;
 894         }
 895
 896         spin_unlock_bh(&bat_priv->vis_hash_lock);
 897         batadv_start_vis_timer(bat_priv);
 898         return 0;
 899
 900 free_info:
 901         kfree(bat_priv->my_vis_info);
 902         bat_priv->my_vis_info = NULL;
 903 err:
 904         spin_unlock_bh(&bat_priv->vis_hash_lock);
 905         batadv_vis_quit(bat_priv);
 906         return -ENOMEM;
 907 }
 908
 909 /* Decrease the reference count on a hash item info */
 910 static void batadv_free_info_ref(struct hlist_node *node, void *arg)
 911 {
 912         struct vis_info *info;
 913
 914         info = container_of(node, struct vis_info, hash_entry);
 915         batadv_send_list_del(info);
 916         kref_put(&info->refcount, batadv_free_info);
 917 }
 918
 919 /* shutdown vis-server */
 920 void batadv_vis_quit(struct bat_priv *bat_priv)
 921 {
 922         if (!bat_priv->vis_hash)
 923                 return;
 924
 925         cancel_delayed_work_sync(&bat_priv->vis_work);
 926
 927         spin_lock_bh(&bat_priv->vis_hash_lock);
 928         /* properly remove, kill timers ... */
 929         batadv_hash_delete(bat_priv->vis_hash, batadv_free_info_ref, NULL);
 930         bat_priv->vis_hash = NULL;
 931         bat_priv->my_vis_info = NULL;
 932         spin_unlock_bh(&bat_priv->vis_hash_lock);
 933 }
 934
 935 /* schedule packets for (re)transmission */
 936 static void batadv_start_vis_timer(struct bat_priv *bat_priv)
 937 {
 938         INIT_DELAYED_WORK(&bat_priv->vis_work, batadv_send_vis_packets);
 939         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis_work,
 940                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 941 }