net/batman-adv/vis.c

   1 /* Copyright (C) 2008-2013 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 /* hash class keys */
  32 static struct lock_class_key batadv_vis_hash_lock_class_key;
  33
  34 /* free the info */
  35 static void batadv_free_info(struct kref *ref)
  36 {
  37         struct batadv_vis_info *info;
  38         struct batadv_priv *bat_priv;
  39         struct batadv_vis_recvlist_node *entry, *tmp;
  40
  41         info = container_of(ref, struct batadv_vis_info, refcount);
  42         bat_priv = info->bat_priv;
  43
  44         list_del_init(&info->send_list);
  45         spin_lock_bh(&bat_priv->vis.list_lock);
  46         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  47                 list_del(&entry->list);
  48                 kfree(entry);
  49         }
  50
  51         spin_unlock_bh(&bat_priv->vis.list_lock);
  52         kfree_skb(info->skb_packet);
  53         kfree(info);
  54 }
  55
  56 /* Compare two vis packets, used by the hashing algorithm */
  57 static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
  58 {
  59         const struct batadv_vis_info *d1, *d2;
  60         const struct batadv_vis_packet *p1, *p2;
  61
  62         d1 = container_of(node, struct batadv_vis_info, hash_entry);
  63         d2 = data2;
  64         p1 = (struct batadv_vis_packet *)d1->skb_packet->data;
  65         p2 = (struct batadv_vis_packet *)d2->skb_packet->data;
  66         return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
  67 }
  68
  69 /* hash function to choose an entry in a hash table of given size
  70  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  71  */
  72 static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
  73 {
  74         const struct batadv_vis_info *vis_info = data;
  75         const struct batadv_vis_packet *packet;
  76         const unsigned char *key;
  77         uint32_t hash = 0;
  78         size_t i;
  79
  80         packet = (struct batadv_vis_packet *)vis_info->skb_packet->data;
  81         key = packet->vis_orig;
  82         for (i = 0; i < ETH_ALEN; i++) {
  83                 hash += key[i];
  84                 hash += (hash << 10);
  85                 hash ^= (hash >> 6);
  86         }
  87
  88         hash += (hash << 3);
  89         hash ^= (hash >> 11);
  90         hash += (hash << 15);
  91
  92         return hash % size;
  93 }
  94
  95 static struct batadv_vis_info *
  96 batadv_vis_hash_find(struct batadv_priv *bat_priv, const void *data)
  97 {
  98         struct batadv_hashtable *hash = bat_priv->vis.hash;
  99         struct hlist_head *head;
 100         struct batadv_vis_info *vis_info, *vis_info_tmp = NULL;
 101         uint32_t index;
 102
 103         if (!hash)
 104                 return NULL;
 105
 106         index = batadv_vis_info_choose(data, hash->size);
 107         head = &hash->table[index];
 108
 109         rcu_read_lock();
 110         hlist_for_each_entry_rcu(vis_info, head, hash_entry) {
 111                 if (!batadv_vis_info_cmp(&vis_info->hash_entry, data))
 112                         continue;
 113
 114                 vis_info_tmp = vis_info;
 115                 break;
 116         }
 117         rcu_read_unlock();
 118
 119         return vis_info_tmp;
 120 }
 121
 122 /* insert interface to the list of interfaces of one originator, if it
 123  * does not already exist in the list
 124  */
 125 static void batadv_vis_data_insert_interface(const uint8_t *interface,
 126                                              struct hlist_head *if_list,
 127                                              bool primary)
 128 {
 129         struct batadv_vis_if_list_entry *entry;
 130
 131         hlist_for_each_entry(entry, if_list, list) {
 132                 if (batadv_compare_eth(entry->addr, interface))
 133                         return;
 134         }
 135
 136         /* it's a new address, add it to the list */
 137         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 138         if (!entry)
 139                 return;
 140         memcpy(entry->addr, interface, ETH_ALEN);
 141         entry->primary = primary;
 142         hlist_add_head(&entry->list, if_list);
 143 }
 144
 145 static void batadv_vis_data_read_prim_sec(struct seq_file *seq,
 146                                           const struct hlist_head *if_list)
 147 {
 148         struct batadv_vis_if_list_entry *entry;
 149
 150         hlist_for_each_entry(entry, if_list, list) {
 151                 if (entry->primary)
 152                         seq_puts(seq, "PRIMARY, ");
 153                 else
 154                         seq_printf(seq,  "SEC %pM, ", entry->addr);
 155         }
 156 }
 157
 158 /* read an entry  */
 159 static ssize_t
 160 batadv_vis_data_read_entry(struct seq_file *seq,
 161                            const struct batadv_vis_info_entry *entry,
 162                            const uint8_t *src, bool primary)
 163 {
 164         if (primary && entry->quality == 0)
 165                 return seq_printf(seq, "TT %pM, ", entry->dest);
 166         else if (batadv_compare_eth(entry->src, src))
 167                 return seq_printf(seq, "TQ %pM %d, ", entry->dest,
 168                                   entry->quality);
 169
 170         return 0;
 171 }
 172
 173 static void
 174 batadv_vis_data_insert_interfaces(struct hlist_head *list,
 175                                   struct batadv_vis_packet *packet,
 176                                   struct batadv_vis_info_entry *entries)
 177 {
 178         int i;
 179
 180         for (i = 0; i < packet->entries; i++) {
 181                 if (entries[i].quality == 0)
 182                         continue;
 183
 184                 if (batadv_compare_eth(entries[i].src, packet->vis_orig))
 185                         continue;
 186
 187                 batadv_vis_data_insert_interface(entries[i].src, list, false);
 188         }
 189 }
 190
 191 static void batadv_vis_data_read_entries(struct seq_file *seq,
 192                                          struct hlist_head *list,
 193                                          struct batadv_vis_packet *packet,
 194                                          struct batadv_vis_info_entry *entries)
 195 {
 196         int i;
 197         struct batadv_vis_if_list_entry *entry;
 198
 199         hlist_for_each_entry(entry, list, list) {
 200                 seq_printf(seq, "%pM,", entry->addr);
 201
 202                 for (i = 0; i < packet->entries; i++)
 203                         batadv_vis_data_read_entry(seq, &entries[i],
 204                                                    entry->addr, entry->primary);
 205
 206                 /* add primary/secondary records */
 207                 if (batadv_compare_eth(entry->addr, packet->vis_orig))
 208                         batadv_vis_data_read_prim_sec(seq, list);
 209
 210                 seq_puts(seq, "\n");
 211         }
 212 }
 213
 214 static void batadv_vis_seq_print_text_bucket(struct seq_file *seq,
 215                                              const struct hlist_head *head)
 216 {
 217         struct batadv_vis_info *info;
 218         struct batadv_vis_packet *packet;
 219         uint8_t *entries_pos;
 220         struct batadv_vis_info_entry *entries;
 221         struct batadv_vis_if_list_entry *entry;
 222         struct hlist_node *n;
 223
 224         HLIST_HEAD(vis_if_list);
 225
 226         hlist_for_each_entry_rcu(info, head, hash_entry) {
 227                 packet = (struct batadv_vis_packet *)info->skb_packet->data;
 228                 entries_pos = (uint8_t *)packet + sizeof(*packet);
 229                 entries = (struct batadv_vis_info_entry *)entries_pos;
 230
 231                 batadv_vis_data_insert_interface(packet->vis_orig, &vis_if_list,
 232                                                  true);
 233                 batadv_vis_data_insert_interfaces(&vis_if_list, packet,
 234                                                   entries);
 235                 batadv_vis_data_read_entries(seq, &vis_if_list, packet,
 236                                              entries);
 237
 238                 hlist_for_each_entry_safe(entry, n, &vis_if_list, list) {
 239                         hlist_del(&entry->list);
 240                         kfree(entry);
 241                 }
 242         }
 243 }
 244
 245 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 246 {
 247         struct batadv_hard_iface *primary_if;
 248         struct hlist_head *head;
 249         struct net_device *net_dev = (struct net_device *)seq->private;
 250         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 251         struct batadv_hashtable *hash = bat_priv->vis.hash;
 252         uint32_t i;
 253         int ret = 0;
 254         int vis_server = atomic_read(&bat_priv->vis_mode);
 255
 256         primary_if = batadv_primary_if_get_selected(bat_priv);
 257         if (!primary_if)
 258                 goto out;
 259
 260         if (vis_server == BATADV_VIS_TYPE_CLIENT_UPDATE)
 261                 goto out;
 262
 263         spin_lock_bh(&bat_priv->vis.hash_lock);
 264         for (i = 0; i < hash->size; i++) {
 265                 head = &hash->table[i];
 266                 batadv_vis_seq_print_text_bucket(seq, head);
 267         }
 268         spin_unlock_bh(&bat_priv->vis.hash_lock);
 269
 270 out:
 271         if (primary_if)
 272                 batadv_hardif_free_ref(primary_if);
 273         return ret;
 274 }
 275
 276 /* add the info packet to the send list, if it was not
 277  * already linked in.
 278  */
 279 static void batadv_send_list_add(struct batadv_priv *bat_priv,
 280                                  struct batadv_vis_info *info)
 281 {
 282         if (list_empty(&info->send_list)) {
 283                 kref_get(&info->refcount);
 284                 list_add_tail(&info->send_list, &bat_priv->vis.send_list);
 285         }
 286 }
 287
 288 /* delete the info packet from the send list, if it was
 289  * linked in.
 290  */
 291 static void batadv_send_list_del(struct batadv_vis_info *info)
 292 {
 293         if (!list_empty(&info->send_list)) {
 294                 list_del_init(&info->send_list);
 295                 kref_put(&info->refcount, batadv_free_info);
 296         }
 297 }
 298
 299 /* tries to add one entry to the receive list. */
 300 static void batadv_recv_list_add(struct batadv_priv *bat_priv,
 301                                  struct list_head *recv_list, const char *mac)
 302 {
 303         struct batadv_vis_recvlist_node *entry;
 304
 305         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 306         if (!entry)
 307                 return;
 308
 309         memcpy(entry->mac, mac, ETH_ALEN);
 310         spin_lock_bh(&bat_priv->vis.list_lock);
 311         list_add_tail(&entry->list, recv_list);
 312         spin_unlock_bh(&bat_priv->vis.list_lock);
 313 }
 314
 315 /* returns 1 if this mac is in the recv_list */
 316 static int batadv_recv_list_is_in(struct batadv_priv *bat_priv,
 317                                   const struct list_head *recv_list,
 318                                   const char *mac)
 319 {
 320         const struct batadv_vis_recvlist_node *entry;
 321
 322         spin_lock_bh(&bat_priv->vis.list_lock);
 323         list_for_each_entry(entry, recv_list, list) {
 324                 if (batadv_compare_eth(entry->mac, mac)) {
 325                         spin_unlock_bh(&bat_priv->vis.list_lock);
 326                         return 1;
 327                 }
 328         }
 329         spin_unlock_bh(&bat_priv->vis.list_lock);
 330         return 0;
 331 }
 332
 333 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 334  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 335  * is newer than old entries in the hash.
 336  */
 337 static struct batadv_vis_info *
 338 batadv_add_packet(struct batadv_priv *bat_priv,
 339                   struct batadv_vis_packet *vis_packet, int vis_info_len,
 340                   int *is_new, int make_broadcast)
 341 {
 342         struct batadv_vis_info *info, *old_info;
 343         struct batadv_vis_packet *search_packet, *old_packet;
 344         struct batadv_vis_info search_elem;
 345         struct batadv_vis_packet *packet;
 346         struct sk_buff *tmp_skb;
 347         int hash_added;
 348         size_t len;
 349         size_t max_entries;
 350
 351         *is_new = 0;
 352         /* sanity check */
 353         if (!bat_priv->vis.hash)
 354                 return NULL;
 355
 356         /* see if the packet is already in vis_hash */
 357         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 358         if (!search_elem.skb_packet)
 359                 return NULL;
 360         len = sizeof(*search_packet);
 361         tmp_skb = search_elem.skb_packet;
 362         search_packet = (struct batadv_vis_packet *)skb_put(tmp_skb, len);
 363
 364         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 365         old_info = batadv_vis_hash_find(bat_priv, &search_elem);
 366         kfree_skb(search_elem.skb_packet);
 367
 368         if (old_info) {
 369                 tmp_skb = old_info->skb_packet;
 370                 old_packet = (struct batadv_vis_packet *)tmp_skb->data;
 371                 if (!batadv_seq_after(ntohl(vis_packet->seqno),
 372                                       ntohl(old_packet->seqno))) {
 373                         if (old_packet->seqno == vis_packet->seqno) {
 374                                 batadv_recv_list_add(bat_priv,
 375                                                      &old_info->recv_list,
 376                                                      vis_packet->sender_orig);
 377                                 return old_info;
 378                         } else {
 379                                 /* newer packet is already in hash. */
 380                                 return NULL;
 381                         }
 382                 }
 383                 /* remove old entry */
 384                 batadv_hash_remove(bat_priv->vis.hash, batadv_vis_info_cmp,
 385                                    batadv_vis_info_choose, old_info);
 386                 batadv_send_list_del(old_info);
 387                 kref_put(&old_info->refcount, batadv_free_info);
 388         }
 389
 390         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 391         if (!info)
 392                 return NULL;
 393
 394         len = sizeof(*packet) + vis_info_len;
 395         info->skb_packet = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN);
 396         if (!info->skb_packet) {
 397                 kfree(info);
 398                 return NULL;
 399         }
 400         skb_reserve(info->skb_packet, ETH_HLEN);
 401         packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
 402
 403         kref_init(&info->refcount);
 404         INIT_LIST_HEAD(&info->send_list);
 405         INIT_LIST_HEAD(&info->recv_list);
 406         info->first_seen = jiffies;
 407         info->bat_priv = bat_priv;
 408         memcpy(packet, vis_packet, len);
 409
 410         /* initialize and add new packet. */
 411         *is_new = 1;
 412
 413         /* Make it a broadcast packet, if required */
 414         if (make_broadcast)
 415                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 416
 417         /* repair if entries is longer than packet. */
 418         max_entries = vis_info_len / sizeof(struct batadv_vis_info_entry);
 419         if (packet->entries > max_entries)
 420                 packet->entries = max_entries;
 421
 422         batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 423
 424         /* try to add it */
 425         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 426                                      batadv_vis_info_choose, info,
 427                                      &info->hash_entry);
 428         if (hash_added != 0) {
 429                 /* did not work (for some reason) */
 430                 kref_put(&info->refcount, batadv_free_info);
 431                 info = NULL;
 432         }
 433
 434         return info;
 435 }
 436
 437 /* handle the server sync packet, forward if needed. */
 438 void batadv_receive_server_sync_packet(struct batadv_priv *bat_priv,
 439                                        struct batadv_vis_packet *vis_packet,
 440                                        int vis_info_len)
 441 {
 442         struct batadv_vis_info *info;
 443         int is_new, make_broadcast;
 444         int vis_server = atomic_read(&bat_priv->vis_mode);
 445
 446         make_broadcast = (vis_server == BATADV_VIS_TYPE_SERVER_SYNC);
 447
 448         spin_lock_bh(&bat_priv->vis.hash_lock);
 449         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 450                                  &is_new, make_broadcast);
 451         if (!info)
 452                 goto end;
 453
 454         /* only if we are server ourselves and packet is newer than the one in
 455          * hash.
 456          */
 457         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC && is_new)
 458                 batadv_send_list_add(bat_priv, info);
 459 end:
 460         spin_unlock_bh(&bat_priv->vis.hash_lock);
 461 }
 462
 463 /* handle an incoming client update packet and schedule forward if needed. */
 464 void batadv_receive_client_update_packet(struct batadv_priv *bat_priv,
 465                                          struct batadv_vis_packet *vis_packet,
 466                                          int vis_info_len)
 467 {
 468         struct batadv_vis_info *info;
 469         struct batadv_vis_packet *packet;
 470         int is_new;
 471         int vis_server = atomic_read(&bat_priv->vis_mode);
 472         int are_target = 0;
 473
 474         /* clients shall not broadcast. */
 475         if (is_broadcast_ether_addr(vis_packet->target_orig))
 476                 return;
 477
 478         /* Are we the target for this VIS packet? */
 479         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC   &&
 480             batadv_is_my_mac(bat_priv, vis_packet->target_orig))
 481                 are_target = 1;
 482
 483         spin_lock_bh(&bat_priv->vis.hash_lock);
 484         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 485                                  &is_new, are_target);
 486
 487         if (!info)
 488                 goto end;
 489         /* note that outdated packets will be dropped at this point. */
 490
 491         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 492
 493         /* send only if we're the target server or ... */
 494         if (are_target && is_new) {
 495                 packet->vis_type = BATADV_VIS_TYPE_SERVER_SYNC; /* upgrade! */
 496                 batadv_send_list_add(bat_priv, info);
 497
 498                 /* ... we're not the recipient (and thus need to forward). */
 499         } else if (!batadv_is_my_mac(bat_priv, packet->target_orig)) {
 500                 batadv_send_list_add(bat_priv, info);
 501         }
 502
 503 end:
 504         spin_unlock_bh(&bat_priv->vis.hash_lock);
 505 }
 506
 507 /* Walk the originators and find the VIS server with the best tq. Set the packet
 508  * address to its address and return the best_tq.
 509  *
 510  * Must be called with the originator hash locked
 511  */
 512 static int batadv_find_best_vis_server(struct batadv_priv *bat_priv,
 513                                        struct batadv_vis_info *info)
 514 {
 515         struct batadv_hashtable *hash = bat_priv->orig_hash;
 516         struct batadv_neigh_node *router;
 517         struct hlist_head *head;
 518         struct batadv_orig_node *orig_node;
 519         struct batadv_vis_packet *packet;
 520         int best_tq = -1;
 521         uint32_t i;
 522
 523         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 524
 525         for (i = 0; i < hash->size; i++) {
 526                 head = &hash->table[i];
 527
 528                 rcu_read_lock();
 529                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 530                         router = batadv_orig_node_get_router(orig_node);
 531                         if (!router)
 532                                 continue;
 533
 534                         if ((orig_node->flags & BATADV_VIS_SERVER) &&
 535                             (router->tq_avg > best_tq)) {
 536                                 best_tq = router->tq_avg;
 537                                 memcpy(packet->target_orig, orig_node->orig,
 538                                        ETH_ALEN);
 539                         }
 540                         batadv_neigh_node_free_ref(router);
 541                 }
 542                 rcu_read_unlock();
 543         }
 544
 545         return best_tq;
 546 }
 547
 548 /* Return true if the vis packet is full. */
 549 static bool batadv_vis_packet_full(const struct batadv_vis_info *info)
 550 {
 551         const struct batadv_vis_packet *packet;
 552         size_t num;
 553
 554         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 555         num = BATADV_MAX_VIS_PACKET_SIZE / sizeof(struct batadv_vis_info_entry);
 556
 557         if (num < packet->entries + 1)
 558                 return true;
 559         return false;
 560 }
 561
 562 /* generates a packet of own vis data,
 563  * returns 0 on success, -1 if no packet could be generated
 564  */
 565 static int batadv_generate_vis_packet(struct batadv_priv *bat_priv)
 566 {
 567         struct batadv_hashtable *hash = bat_priv->orig_hash;
 568         struct hlist_head *head;
 569         struct batadv_orig_node *orig_node;
 570         struct batadv_neigh_node *router;
 571         struct batadv_vis_info *info = bat_priv->vis.my_info;
 572         struct batadv_vis_packet *packet;
 573         struct batadv_vis_info_entry *entry;
 574         struct batadv_tt_common_entry *tt_common_entry;
 575         uint8_t *packet_pos;
 576         int best_tq = -1;
 577         uint32_t i;
 578
 579         info->first_seen = jiffies;
 580         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 581         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 582
 583         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 584         packet->header.ttl = BATADV_TTL;
 585         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 586         packet->entries = 0;
 587         packet->reserved = 0;
 588         skb_trim(info->skb_packet, sizeof(*packet));
 589
 590         if (packet->vis_type == BATADV_VIS_TYPE_CLIENT_UPDATE) {
 591                 best_tq = batadv_find_best_vis_server(bat_priv, info);
 592
 593                 if (best_tq < 0)
 594                         return best_tq;
 595         }
 596
 597         for (i = 0; i < hash->size; i++) {
 598                 head = &hash->table[i];
 599
 600                 rcu_read_lock();
 601                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 602                         router = batadv_orig_node_get_router(orig_node);
 603                         if (!router)
 604                                 continue;
 605
 606                         if (!batadv_compare_eth(router->addr, orig_node->orig))
 607                                 goto next;
 608
 609                         if (router->if_incoming->if_status != BATADV_IF_ACTIVE)
 610                                 goto next;
 611
 612                         if (router->tq_avg < 1)
 613                                 goto next;
 614
 615                         /* fill one entry into buffer. */
 616                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 617                         entry = (struct batadv_vis_info_entry *)packet_pos;
 618                         memcpy(entry->src,
 619                                router->if_incoming->net_dev->dev_addr,
 620                                ETH_ALEN);
 621                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 622                         entry->quality = router->tq_avg;
 623                         packet->entries++;
 624
 625 next:
 626                         batadv_neigh_node_free_ref(router);
 627
 628                         if (batadv_vis_packet_full(info))
 629                                 goto unlock;
 630                 }
 631                 rcu_read_unlock();
 632         }
 633
 634         hash = bat_priv->tt.local_hash;
 635
 636         for (i = 0; i < hash->size; i++) {
 637                 head = &hash->table[i];
 638
 639                 rcu_read_lock();
 640                 hlist_for_each_entry_rcu(tt_common_entry, head,
 641                                          hash_entry) {
 642                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 643                         entry = (struct batadv_vis_info_entry *)packet_pos;
 644                         memset(entry->src, 0, ETH_ALEN);
 645                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 646                         entry->quality = 0; /* 0 means TT */
 647                         packet->entries++;
 648
 649                         if (batadv_vis_packet_full(info))
 650                                 goto unlock;
 651                 }
 652                 rcu_read_unlock();
 653         }
 654
 655         return 0;
 656
 657 unlock:
 658         rcu_read_unlock();
 659         return 0;
 660 }
 661
 662 /* free old vis packets. Must be called with this vis_hash_lock
 663  * held
 664  */
 665 static void batadv_purge_vis_packets(struct batadv_priv *bat_priv)
 666 {
 667         uint32_t i;
 668         struct batadv_hashtable *hash = bat_priv->vis.hash;
 669         struct hlist_node *node_tmp;
 670         struct hlist_head *head;
 671         struct batadv_vis_info *info;
 672
 673         for (i = 0; i < hash->size; i++) {
 674                 head = &hash->table[i];
 675
 676                 hlist_for_each_entry_safe(info, node_tmp,
 677                                           head, hash_entry) {
 678                         /* never purge own data. */
 679                         if (info == bat_priv->vis.my_info)
 680                                 continue;
 681
 682                         if (batadv_has_timed_out(info->first_seen,
 683                                                  BATADV_VIS_TIMEOUT)) {
 684                                 hlist_del(&info->hash_entry);
 685                                 batadv_send_list_del(info);
 686                                 kref_put(&info->refcount, batadv_free_info);
 687                         }
 688                 }
 689         }
 690 }
 691
 692 static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
 693                                         struct batadv_vis_info *info)
 694 {
 695         struct batadv_hashtable *hash = bat_priv->orig_hash;
 696         struct hlist_head *head;
 697         struct batadv_orig_node *orig_node;
 698         struct batadv_vis_packet *packet;
 699         struct sk_buff *skb;
 700         uint32_t i, res;
 701
 702
 703         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 704
 705         /* send to all routers in range. */
 706         for (i = 0; i < hash->size; i++) {
 707                 head = &hash->table[i];
 708
 709                 rcu_read_lock();
 710                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 711                         /* if it's a vis server and reachable, send it. */
 712                         if (!(orig_node->flags & BATADV_VIS_SERVER))
 713                                 continue;
 714
 715                         /* don't send it if we already received the packet from
 716                          * this node.
 717                          */
 718                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
 719                                                    orig_node->orig))
 720                                 continue;
 721
 722                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 723                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 724                         if (!skb)
 725                                 continue;
 726
 727                         res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 728                         if (res == NET_XMIT_DROP)
 729                                 kfree_skb(skb);
 730                 }
 731                 rcu_read_unlock();
 732         }
 733 }
 734
 735 static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
 736                                       struct batadv_vis_info *info)
 737 {
 738         struct batadv_orig_node *orig_node;
 739         struct sk_buff *skb;
 740         struct batadv_vis_packet *packet;
 741
 742         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 743
 744         orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
 745         if (!orig_node)
 746                 goto out;
 747
 748         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 749         if (!skb)
 750                 goto out;
 751
 752         if (batadv_send_skb_to_orig(skb, orig_node, NULL) == NET_XMIT_DROP)
 753                 kfree_skb(skb);
 754
 755 out:
 756         if (orig_node)
 757                 batadv_orig_node_free_ref(orig_node);
 758 }
 759
 760 /* only send one vis packet. called from batadv_send_vis_packets() */
 761 static void batadv_send_vis_packet(struct batadv_priv *bat_priv,
 762                                    struct batadv_vis_info *info)
 763 {
 764         struct batadv_hard_iface *primary_if;
 765         struct batadv_vis_packet *packet;
 766
 767         primary_if = batadv_primary_if_get_selected(bat_priv);
 768         if (!primary_if)
 769                 goto out;
 770
 771         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 772         if (packet->header.ttl < 2) {
 773                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 774                 goto out;
 775         }
 776
 777         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 778         packet->header.ttl--;
 779
 780         if (is_broadcast_ether_addr(packet->target_orig))
 781                 batadv_broadcast_vis_packet(bat_priv, info);
 782         else
 783                 batadv_unicast_vis_packet(bat_priv, info);
 784         packet->header.ttl++; /* restore TTL */
 785
 786 out:
 787         if (primary_if)
 788                 batadv_hardif_free_ref(primary_if);
 789 }
 790
 791 /* called from timer; send (and maybe generate) vis packet. */
 792 static void batadv_send_vis_packets(struct work_struct *work)
 793 {
 794         struct delayed_work *delayed_work;
 795         struct batadv_priv *bat_priv;
 796         struct batadv_priv_vis *priv_vis;
 797         struct batadv_vis_info *info;
 798
 799         delayed_work = container_of(work, struct delayed_work, work);
 800         priv_vis = container_of(delayed_work, struct batadv_priv_vis, work);
 801         bat_priv = container_of(priv_vis, struct batadv_priv, vis);
 802         spin_lock_bh(&bat_priv->vis.hash_lock);
 803         batadv_purge_vis_packets(bat_priv);
 804
 805         if (batadv_generate_vis_packet(bat_priv) == 0) {
 806                 /* schedule if generation was successful */
 807                 batadv_send_list_add(bat_priv, bat_priv->vis.my_info);
 808         }
 809
 810         while (!list_empty(&bat_priv->vis.send_list)) {
 811                 info = list_first_entry(&bat_priv->vis.send_list,
 812                                         typeof(*info), send_list);
 813
 814                 kref_get(&info->refcount);
 815                 spin_unlock_bh(&bat_priv->vis.hash_lock);
 816
 817                 batadv_send_vis_packet(bat_priv, info);
 818
 819                 spin_lock_bh(&bat_priv->vis.hash_lock);
 820                 batadv_send_list_del(info);
 821                 kref_put(&info->refcount, batadv_free_info);
 822         }
 823         spin_unlock_bh(&bat_priv->vis.hash_lock);
 824
 825         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
 826                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 827 }
 828
 829 /* init the vis server. this may only be called when if_list is already
 830  * initialized (e.g. bat0 is initialized, interfaces have been added)
 831  */
 832 int batadv_vis_init(struct batadv_priv *bat_priv)
 833 {
 834         struct batadv_vis_packet *packet;
 835         int hash_added;
 836         unsigned int len;
 837         unsigned long first_seen;
 838         struct sk_buff *tmp_skb;
 839
 840         if (bat_priv->vis.hash)
 841                 return 0;
 842
 843         spin_lock_bh(&bat_priv->vis.hash_lock);
 844
 845         bat_priv->vis.hash = batadv_hash_new(256);
 846         if (!bat_priv->vis.hash) {
 847                 pr_err("Can't initialize vis_hash\n");
 848                 goto err;
 849         }
 850
 851         batadv_hash_set_lock_class(bat_priv->vis.hash,
 852                                    &batadv_vis_hash_lock_class_key);
 853
 854         bat_priv->vis.my_info = kmalloc(BATADV_MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 855         if (!bat_priv->vis.my_info)
 856                 goto err;
 857
 858         len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE + ETH_HLEN;
 859         bat_priv->vis.my_info->skb_packet = netdev_alloc_skb_ip_align(NULL,
 860                                                                       len);
 861         if (!bat_priv->vis.my_info->skb_packet)
 862                 goto free_info;
 863
 864         skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN);
 865         tmp_skb = bat_priv->vis.my_info->skb_packet;
 866         packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));
 867
 868         /* prefill the vis info */
 869         first_seen = jiffies - msecs_to_jiffies(BATADV_VIS_INTERVAL);
 870         bat_priv->vis.my_info->first_seen = first_seen;
 871         INIT_LIST_HEAD(&bat_priv->vis.my_info->recv_list);
 872         INIT_LIST_HEAD(&bat_priv->vis.my_info->send_list);
 873         kref_init(&bat_priv->vis.my_info->refcount);
 874         bat_priv->vis.my_info->bat_priv = bat_priv;
 875         packet->header.version = BATADV_COMPAT_VERSION;
 876         packet->header.packet_type = BATADV_VIS;
 877         packet->header.ttl = BATADV_TTL;
 878         packet->seqno = 0;
 879         packet->reserved = 0;
 880         packet->entries = 0;
 881
 882         INIT_LIST_HEAD(&bat_priv->vis.send_list);
 883
 884         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 885                                      batadv_vis_info_choose,
 886                                      bat_priv->vis.my_info,
 887                                      &bat_priv->vis.my_info->hash_entry);
 888         if (hash_added != 0) {
 889                 pr_err("Can't add own vis packet into hash\n");
 890                 /* not in hash, need to remove it manually. */
 891                 kref_put(&bat_priv->vis.my_info->refcount, batadv_free_info);
 892                 goto err;
 893         }
 894
 895         spin_unlock_bh(&bat_priv->vis.hash_lock);
 896
 897         INIT_DELAYED_WORK(&bat_priv->vis.work, batadv_send_vis_packets);
 898         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
 899                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 900
 901         return 0;
 902
 903 free_info:
 904         kfree(bat_priv->vis.my_info);
 905         bat_priv->vis.my_info = NULL;
 906 err:
 907         spin_unlock_bh(&bat_priv->vis.hash_lock);
 908         batadv_vis_quit(bat_priv);
 909         return -ENOMEM;
 910 }
 911
 912 /* Decrease the reference count on a hash item info */
 913 static void batadv_free_info_ref(struct hlist_node *node, void *arg)
 914 {
 915         struct batadv_vis_info *info;
 916
 917         info = container_of(node, struct batadv_vis_info, hash_entry);
 918         batadv_send_list_del(info);
 919         kref_put(&info->refcount, batadv_free_info);
 920 }
 921
 922 /* shutdown vis-server */
 923 void batadv_vis_quit(struct batadv_priv *bat_priv)
 924 {
 925         if (!bat_priv->vis.hash)
 926                 return;
 927
 928         cancel_delayed_work_sync(&bat_priv->vis.work);
 929
 930         spin_lock_bh(&bat_priv->vis.hash_lock);
 931         /* properly remove, kill timers ... */
 932         batadv_hash_delete(bat_priv->vis.hash, batadv_free_info_ref, NULL);
 933         bat_priv->vis.hash = NULL;
 934         bat_priv->vis.my_info = NULL;
 935         spin_unlock_bh(&bat_priv->vis.hash_lock);
 936 }