net/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2011 B.A.T.M.A.N. contributors:
   3  *
   4  * Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "translation-table.h"
  25 #include "vis.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "hash.h"
  29 #include "originator.h"
  30
  31 #define MAX_VIS_PACKET_SIZE 1000
  32
  33 static void start_vis_timer(struct bat_priv *bat_priv);
  34
  35 /* free the info */
  36 static void free_info(struct kref *ref)
  37 {
  38         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  39         struct bat_priv *bat_priv = info->bat_priv;
  40         struct recvlist_node *entry, *tmp;
  41
  42         list_del_init(&info->send_list);
  43         spin_lock_bh(&bat_priv->vis_list_lock);
  44         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  45                 list_del(&entry->list);
  46                 kfree(entry);
  47         }
  48
  49         spin_unlock_bh(&bat_priv->vis_list_lock);
  50         kfree_skb(info->skb_packet);
  51         kfree(info);
  52 }
  53
  54 /* Compare two vis packets, used by the hashing algorithm */
  55 static int vis_info_cmp(const struct hlist_node *node, const void *data2)
  56 {
  57         const struct vis_info *d1, *d2;
  58         const struct vis_packet *p1, *p2;
  59
  60         d1 = container_of(node, struct vis_info, hash_entry);
  61         d2 = data2;
  62         p1 = (struct vis_packet *)d1->skb_packet->data;
  63         p2 = (struct vis_packet *)d2->skb_packet->data;
  64         return compare_eth(p1->vis_orig, p2->vis_orig);
  65 }
  66
  67 /* hash function to choose an entry in a hash table of given size */
  68 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  69 static int vis_info_choose(const void *data, int size)
  70 {
  71         const struct vis_info *vis_info = data;
  72         const struct vis_packet *packet;
  73         const unsigned char *key;
  74         uint32_t hash = 0;
  75         size_t i;
  76
  77         packet = (struct vis_packet *)vis_info->skb_packet->data;
  78         key = packet->vis_orig;
  79         for (i = 0; i < ETH_ALEN; i++) {
  80                 hash += key[i];
  81                 hash += (hash << 10);
  82                 hash ^= (hash >> 6);
  83         }
  84
  85         hash += (hash << 3);
  86         hash ^= (hash >> 11);
  87         hash += (hash << 15);
  88
  89         return hash % size;
  90 }
  91
  92 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
  93                                       const void *data)
  94 {
  95         struct hashtable_t *hash = bat_priv->vis_hash;
  96         struct hlist_head *head;
  97         struct hlist_node *node;
  98         struct vis_info *vis_info, *vis_info_tmp = NULL;
  99         int index;
 100
 101         if (!hash)
 102                 return NULL;
 103
 104         index = vis_info_choose(data, hash->size);
 105         head = &hash->table[index];
 106
 107         rcu_read_lock();
 108         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 109                 if (!vis_info_cmp(node, data))
 110                         continue;
 111
 112                 vis_info_tmp = vis_info;
 113                 break;
 114         }
 115         rcu_read_unlock();
 116
 117         return vis_info_tmp;
 118 }
 119
 120 /* insert interface to the list of interfaces of one originator, if it
 121  * does not already exist in the list */
 122 static void 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 (compare_eth(entry->addr, interface))
 131                         return;
 132         }
 133
 134         /* its 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 ssize_t vis_data_read_prim_sec(char *buff,
 144                                       const struct hlist_head *if_list)
 145 {
 146         struct if_list_entry *entry;
 147         struct hlist_node *pos;
 148         size_t len = 0;
 149
 150         hlist_for_each_entry(entry, pos, if_list, list) {
 151                 if (entry->primary)
 152                         len += sprintf(buff + len, "PRIMARY, ");
 153                 else
 154                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 155         }
 156
 157         return len;
 158 }
 159
 160 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 161 {
 162         struct if_list_entry *entry;
 163         struct hlist_node *pos;
 164         size_t count = 0;
 165
 166         hlist_for_each_entry(entry, pos, if_list, list) {
 167                 if (entry->primary)
 168                         count += 9;
 169                 else
 170                         count += 23;
 171         }
 172
 173         return count;
 174 }
 175
 176 /* read an entry  */
 177 static ssize_t vis_data_read_entry(char *buff,
 178                                    const struct vis_info_entry *entry,
 179                                    const uint8_t *src, bool primary)
 180 {
 181         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 182         if (primary && entry->quality == 0)
 183                 return sprintf(buff, "TT %pM, ", entry->dest);
 184         else if (compare_eth(entry->src, src))
 185                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 186                                entry->quality);
 187
 188         return 0;
 189 }
 190
 191 int vis_seq_print_text(struct seq_file *seq, void *offset)
 192 {
 193         struct hard_iface *primary_if;
 194         struct hlist_node *node;
 195         struct hlist_head *head;
 196         struct vis_info *info;
 197         struct vis_packet *packet;
 198         struct vis_info_entry *entries;
 199         struct net_device *net_dev = (struct net_device *)seq->private;
 200         struct bat_priv *bat_priv = netdev_priv(net_dev);
 201         struct hashtable_t *hash = bat_priv->vis_hash;
 202         HLIST_HEAD(vis_if_list);
 203         struct if_list_entry *entry;
 204         struct hlist_node *pos, *n;
 205         int i, j, ret = 0;
 206         int vis_server = atomic_read(&bat_priv->vis_mode);
 207         size_t buff_pos, buf_size;
 208         char *buff;
 209         int compare;
 210
 211         primary_if = primary_if_get_selected(bat_priv);
 212         if (!primary_if)
 213                 goto out;
 214
 215         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 216                 goto out;
 217
 218         buf_size = 1;
 219         /* Estimate length */
 220         spin_lock_bh(&bat_priv->vis_hash_lock);
 221         for (i = 0; i < hash->size; i++) {
 222                 head = &hash->table[i];
 223
 224                 rcu_read_lock();
 225                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 226                         packet = (struct vis_packet *)info->skb_packet->data;
 227                         entries = (struct vis_info_entry *)
 228                                 ((char *)packet + sizeof(*packet));
 229
 230                         for (j = 0; j < packet->entries; j++) {
 231                                 if (entries[j].quality == 0)
 232                                         continue;
 233                                 compare =
 234                                  compare_eth(entries[j].src, packet->vis_orig);
 235                                 vis_data_insert_interface(entries[j].src,
 236                                                           &vis_if_list,
 237                                                           compare);
 238                         }
 239
 240                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 241                                 buf_size += 18 + 26 * packet->entries;
 242
 243                                 /* add primary/secondary records */
 244                                 if (compare_eth(entry->addr, packet->vis_orig))
 245                                         buf_size +=
 246                                           vis_data_count_prim_sec(&vis_if_list);
 247
 248                                 buf_size += 1;
 249                         }
 250
 251                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 252                                                   list) {
 253                                 hlist_del(&entry->list);
 254                                 kfree(entry);
 255                         }
 256                 }
 257                 rcu_read_unlock();
 258         }
 259
 260         buff = kmalloc(buf_size, GFP_ATOMIC);
 261         if (!buff) {
 262                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 263                 ret = -ENOMEM;
 264                 goto out;
 265         }
 266         buff[0] = '\0';
 267         buff_pos = 0;
 268
 269         for (i = 0; i < hash->size; i++) {
 270                 head = &hash->table[i];
 271
 272                 rcu_read_lock();
 273                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 274                         packet = (struct vis_packet *)info->skb_packet->data;
 275                         entries = (struct vis_info_entry *)
 276                                 ((char *)packet + sizeof(*packet));
 277
 278                         for (j = 0; j < packet->entries; j++) {
 279                                 if (entries[j].quality == 0)
 280                                         continue;
 281                                 compare =
 282                                  compare_eth(entries[j].src, packet->vis_orig);
 283                                 vis_data_insert_interface(entries[j].src,
 284                                                           &vis_if_list,
 285                                                           compare);
 286                         }
 287
 288                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 289                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 290                                                 entry->addr);
 291
 292                                 for (j = 0; j < packet->entries; j++)
 293                                         buff_pos += vis_data_read_entry(
 294                                                         buff + buff_pos,
 295                                                         &entries[j],
 296                                                         entry->addr,
 297                                                         entry->primary);
 298
 299                                 /* add primary/secondary records */
 300                                 if (compare_eth(entry->addr, packet->vis_orig))
 301                                         buff_pos +=
 302                                          vis_data_read_prim_sec(buff + buff_pos,
 303                                                                 &vis_if_list);
 304
 305                                 buff_pos += sprintf(buff + buff_pos, "\n");
 306                         }
 307
 308                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 309                                                   list) {
 310                                 hlist_del(&entry->list);
 311                                 kfree(entry);
 312                         }
 313                 }
 314                 rcu_read_unlock();
 315         }
 316
 317         spin_unlock_bh(&bat_priv->vis_hash_lock);
 318
 319         seq_printf(seq, "%s", buff);
 320         kfree(buff);
 321
 322 out:
 323         if (primary_if)
 324                 hardif_free_ref(primary_if);
 325         return ret;
 326 }
 327
 328 /* add the info packet to the send list, if it was not
 329  * already linked in. */
 330 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 331 {
 332         if (list_empty(&info->send_list)) {
 333                 kref_get(&info->refcount);
 334                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 335         }
 336 }
 337
 338 /* delete the info packet from the send list, if it was
 339  * linked in. */
 340 static void send_list_del(struct vis_info *info)
 341 {
 342         if (!list_empty(&info->send_list)) {
 343                 list_del_init(&info->send_list);
 344                 kref_put(&info->refcount, free_info);
 345         }
 346 }
 347
 348 /* tries to add one entry to the receive list. */
 349 static void recv_list_add(struct bat_priv *bat_priv,
 350                           struct list_head *recv_list, const char *mac)
 351 {
 352         struct recvlist_node *entry;
 353
 354         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 355         if (!entry)
 356                 return;
 357
 358         memcpy(entry->mac, mac, ETH_ALEN);
 359         spin_lock_bh(&bat_priv->vis_list_lock);
 360         list_add_tail(&entry->list, recv_list);
 361         spin_unlock_bh(&bat_priv->vis_list_lock);
 362 }
 363
 364 /* returns 1 if this mac is in the recv_list */
 365 static int recv_list_is_in(struct bat_priv *bat_priv,
 366                            const struct list_head *recv_list, const char *mac)
 367 {
 368         const struct recvlist_node *entry;
 369
 370         spin_lock_bh(&bat_priv->vis_list_lock);
 371         list_for_each_entry(entry, recv_list, list) {
 372                 if (compare_eth(entry->mac, mac)) {
 373                         spin_unlock_bh(&bat_priv->vis_list_lock);
 374                         return 1;
 375                 }
 376         }
 377         spin_unlock_bh(&bat_priv->vis_list_lock);
 378         return 0;
 379 }
 380
 381 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 382  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 383  * is newer than old entries in the hash. */
 384 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 385                                    struct vis_packet *vis_packet,
 386                                    int vis_info_len, int *is_new,
 387                                    int make_broadcast)
 388 {
 389         struct vis_info *info, *old_info;
 390         struct vis_packet *search_packet, *old_packet;
 391         struct vis_info search_elem;
 392         struct vis_packet *packet;
 393         int hash_added;
 394
 395         *is_new = 0;
 396         /* sanity check */
 397         if (!bat_priv->vis_hash)
 398                 return NULL;
 399
 400         /* see if the packet is already in vis_hash */
 401         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 402         if (!search_elem.skb_packet)
 403                 return NULL;
 404         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 405                                                      sizeof(*search_packet));
 406
 407         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 408         old_info = vis_hash_find(bat_priv, &search_elem);
 409         kfree_skb(search_elem.skb_packet);
 410
 411         if (old_info) {
 412                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 413                 if (!seq_after(ntohl(vis_packet->seqno),
 414                                ntohl(old_packet->seqno))) {
 415                         if (old_packet->seqno == vis_packet->seqno) {
 416                                 recv_list_add(bat_priv, &old_info->recv_list,
 417                                               vis_packet->sender_orig);
 418                                 return old_info;
 419                         } else {
 420                                 /* newer packet is already in hash. */
 421                                 return NULL;
 422                         }
 423                 }
 424                 /* remove old entry */
 425                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 426                             old_info);
 427                 send_list_del(old_info);
 428                 kref_put(&old_info->refcount, free_info);
 429         }
 430
 431         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 432         if (!info)
 433                 return NULL;
 434
 435         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 436                                          sizeof(struct ethhdr));
 437         if (!info->skb_packet) {
 438                 kfree(info);
 439                 return NULL;
 440         }
 441         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 442         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 443                                               + vis_info_len);
 444
 445         kref_init(&info->refcount);
 446         INIT_LIST_HEAD(&info->send_list);
 447         INIT_LIST_HEAD(&info->recv_list);
 448         info->first_seen = jiffies;
 449         info->bat_priv = bat_priv;
 450         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 451
 452         /* initialize and add new packet. */
 453         *is_new = 1;
 454
 455         /* Make it a broadcast packet, if required */
 456         if (make_broadcast)
 457                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 458
 459         /* repair if entries is longer than packet. */
 460         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 461                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 462
 463         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 464
 465         /* try to add it */
 466         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 467                               info, &info->hash_entry);
 468         if (hash_added < 0) {
 469                 /* did not work (for some reason) */
 470                 kref_put(&info->refcount, free_info);
 471                 info = NULL;
 472         }
 473
 474         return info;
 475 }
 476
 477 /* handle the server sync packet, forward if needed. */
 478 void receive_server_sync_packet(struct bat_priv *bat_priv,
 479                                 struct vis_packet *vis_packet,
 480                                 int vis_info_len)
 481 {
 482         struct vis_info *info;
 483         int is_new, make_broadcast;
 484         int vis_server = atomic_read(&bat_priv->vis_mode);
 485
 486         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 487
 488         spin_lock_bh(&bat_priv->vis_hash_lock);
 489         info = add_packet(bat_priv, vis_packet, vis_info_len,
 490                           &is_new, make_broadcast);
 491         if (!info)
 492                 goto end;
 493
 494         /* only if we are server ourselves and packet is newer than the one in
 495          * hash.*/
 496         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 497                 send_list_add(bat_priv, info);
 498 end:
 499         spin_unlock_bh(&bat_priv->vis_hash_lock);
 500 }
 501
 502 /* handle an incoming client update packet and schedule forward if needed. */
 503 void receive_client_update_packet(struct bat_priv *bat_priv,
 504                                   struct vis_packet *vis_packet,
 505                                   int vis_info_len)
 506 {
 507         struct vis_info *info;
 508         struct vis_packet *packet;
 509         int is_new;
 510         int vis_server = atomic_read(&bat_priv->vis_mode);
 511         int are_target = 0;
 512
 513         /* clients shall not broadcast. */
 514         if (is_broadcast_ether_addr(vis_packet->target_orig))
 515                 return;
 516
 517         /* Are we the target for this VIS packet? */
 518         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 519             is_my_mac(vis_packet->target_orig))
 520                 are_target = 1;
 521
 522         spin_lock_bh(&bat_priv->vis_hash_lock);
 523         info = add_packet(bat_priv, vis_packet, vis_info_len,
 524                           &is_new, are_target);
 525
 526         if (!info)
 527                 goto end;
 528         /* note that outdated packets will be dropped at this point. */
 529
 530         packet = (struct vis_packet *)info->skb_packet->data;
 531
 532         /* send only if we're the target server or ... */
 533         if (are_target && is_new) {
 534                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 535                 send_list_add(bat_priv, info);
 536
 537                 /* ... we're not the recipient (and thus need to forward). */
 538         } else if (!is_my_mac(packet->target_orig)) {
 539                 send_list_add(bat_priv, info);
 540         }
 541
 542 end:
 543         spin_unlock_bh(&bat_priv->vis_hash_lock);
 544 }
 545
 546 /* Walk the originators and find the VIS server with the best tq. Set the packet
 547  * address to its address and return the best_tq.
 548  *
 549  * Must be called with the originator hash locked */
 550 static int find_best_vis_server(struct bat_priv *bat_priv,
 551                                 struct vis_info *info)
 552 {
 553         struct hashtable_t *hash = bat_priv->orig_hash;
 554         struct neigh_node *router;
 555         struct hlist_node *node;
 556         struct hlist_head *head;
 557         struct orig_node *orig_node;
 558         struct vis_packet *packet;
 559         int best_tq = -1, i;
 560
 561         packet = (struct vis_packet *)info->skb_packet->data;
 562
 563         for (i = 0; i < hash->size; i++) {
 564                 head = &hash->table[i];
 565
 566                 rcu_read_lock();
 567                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 568                         router = orig_node_get_router(orig_node);
 569                         if (!router)
 570                                 continue;
 571
 572                         if ((orig_node->flags & VIS_SERVER) &&
 573                             (router->tq_avg > best_tq)) {
 574                                 best_tq = router->tq_avg;
 575                                 memcpy(packet->target_orig, orig_node->orig,
 576                                        ETH_ALEN);
 577                         }
 578                         neigh_node_free_ref(router);
 579                 }
 580                 rcu_read_unlock();
 581         }
 582
 583         return best_tq;
 584 }
 585
 586 /* Return true if the vis packet is full. */
 587 static bool vis_packet_full(const struct vis_info *info)
 588 {
 589         const struct vis_packet *packet;
 590         packet = (struct vis_packet *)info->skb_packet->data;
 591
 592         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 593                 < packet->entries + 1)
 594                 return true;
 595         return false;
 596 }
 597
 598 /* generates a packet of own vis data,
 599  * returns 0 on success, -1 if no packet could be generated */
 600 static int generate_vis_packet(struct bat_priv *bat_priv)
 601 {
 602         struct hashtable_t *hash = bat_priv->orig_hash;
 603         struct hlist_node *node;
 604         struct hlist_head *head;
 605         struct orig_node *orig_node;
 606         struct neigh_node *router;
 607         struct vis_info *info = bat_priv->my_vis_info;
 608         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 609         struct vis_info_entry *entry;
 610         struct tt_local_entry *tt_local_entry;
 611         int best_tq = -1, i;
 612
 613         info->first_seen = jiffies;
 614         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 615
 616         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 617         packet->ttl = TTL;
 618         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 619         packet->entries = 0;
 620         skb_trim(info->skb_packet, sizeof(*packet));
 621
 622         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 623                 best_tq = find_best_vis_server(bat_priv, info);
 624
 625                 if (best_tq < 0)
 626                         return -1;
 627         }
 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(orig_node, node, head, hash_entry) {
 634                         router = orig_node_get_router(orig_node);
 635                         if (!router)
 636                                 continue;
 637
 638                         if (!compare_eth(router->addr, orig_node->orig))
 639                                 goto next;
 640
 641                         if (router->if_incoming->if_status != IF_ACTIVE)
 642                                 goto next;
 643
 644                         if (router->tq_avg < 1)
 645                                 goto next;
 646
 647                         /* fill one entry into buffer. */
 648                         entry = (struct vis_info_entry *)
 649                                       skb_put(info->skb_packet, sizeof(*entry));
 650                         memcpy(entry->src,
 651                                router->if_incoming->net_dev->dev_addr,
 652                                ETH_ALEN);
 653                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 654                         entry->quality = router->tq_avg;
 655                         packet->entries++;
 656
 657 next:
 658                         neigh_node_free_ref(router);
 659
 660                         if (vis_packet_full(info))
 661                                 goto unlock;
 662                 }
 663                 rcu_read_unlock();
 664         }
 665
 666         hash = bat_priv->tt_local_hash;
 667
 668         for (i = 0; i < hash->size; i++) {
 669                 head = &hash->table[i];
 670
 671                 rcu_read_lock();
 672                 hlist_for_each_entry_rcu(tt_local_entry, node, head,
 673                                          hash_entry) {
 674                         entry = (struct vis_info_entry *)
 675                                         skb_put(info->skb_packet,
 676                                                 sizeof(*entry));
 677                         memset(entry->src, 0, ETH_ALEN);
 678                         memcpy(entry->dest, tt_local_entry->addr, ETH_ALEN);
 679                         entry->quality = 0; /* 0 means TT */
 680                         packet->entries++;
 681
 682                         if (vis_packet_full(info))
 683                                 goto unlock;
 684                 }
 685                 rcu_read_unlock();
 686         }
 687
 688         return 0;
 689
 690 unlock:
 691         rcu_read_unlock();
 692         return 0;
 693 }
 694
 695 /* free old vis packets. Must be called with this vis_hash_lock
 696  * held */
 697 static void purge_vis_packets(struct bat_priv *bat_priv)
 698 {
 699         int i;
 700         struct hashtable_t *hash = bat_priv->vis_hash;
 701         struct hlist_node *node, *node_tmp;
 702         struct hlist_head *head;
 703         struct vis_info *info;
 704
 705         for (i = 0; i < hash->size; i++) {
 706                 head = &hash->table[i];
 707
 708                 hlist_for_each_entry_safe(info, node, node_tmp,
 709                                           head, hash_entry) {
 710                         /* never purge own data. */
 711                         if (info == bat_priv->my_vis_info)
 712                                 continue;
 713
 714                         if (time_after(jiffies,
 715                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 716                                 hlist_del(node);
 717                                 send_list_del(info);
 718                                 kref_put(&info->refcount, free_info);
 719                         }
 720                 }
 721         }
 722 }
 723
 724 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 725                                  struct vis_info *info)
 726 {
 727         struct neigh_node *router;
 728         struct hashtable_t *hash = bat_priv->orig_hash;
 729         struct hlist_node *node;
 730         struct hlist_head *head;
 731         struct orig_node *orig_node;
 732         struct vis_packet *packet;
 733         struct sk_buff *skb;
 734         struct hard_iface *hard_iface;
 735         uint8_t dstaddr[ETH_ALEN];
 736         int i;
 737
 738
 739         packet = (struct vis_packet *)info->skb_packet->data;
 740
 741         /* send to all routers in range. */
 742         for (i = 0; i < hash->size; i++) {
 743                 head = &hash->table[i];
 744
 745                 rcu_read_lock();
 746                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 747                         /* if it's a vis server and reachable, send it. */
 748                         if (!(orig_node->flags & VIS_SERVER))
 749                                 continue;
 750
 751                         router = orig_node_get_router(orig_node);
 752                         if (!router)
 753                                 continue;
 754
 755                         /* don't send it if we already received the packet from
 756                          * this node. */
 757                         if (recv_list_is_in(bat_priv, &info->recv_list,
 758                                             orig_node->orig)) {
 759                                 neigh_node_free_ref(router);
 760                                 continue;
 761                         }
 762
 763                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 764                         hard_iface = router->if_incoming;
 765                         memcpy(dstaddr, router->addr, ETH_ALEN);
 766
 767                         neigh_node_free_ref(router);
 768
 769                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 770                         if (skb)
 771                                 send_skb_packet(skb, hard_iface, dstaddr);
 772
 773                 }
 774                 rcu_read_unlock();
 775         }
 776 }
 777
 778 static void unicast_vis_packet(struct bat_priv *bat_priv,
 779                                struct vis_info *info)
 780 {
 781         struct orig_node *orig_node;
 782         struct neigh_node *router = NULL;
 783         struct sk_buff *skb;
 784         struct vis_packet *packet;
 785
 786         packet = (struct vis_packet *)info->skb_packet->data;
 787
 788         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 789         if (!orig_node)
 790                 goto out;
 791
 792         router = orig_node_get_router(orig_node);
 793         if (!router)
 794                 goto out;
 795
 796         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 797         if (skb)
 798                 send_skb_packet(skb, router->if_incoming, router->addr);
 799
 800 out:
 801         if (router)
 802                 neigh_node_free_ref(router);
 803         if (orig_node)
 804                 orig_node_free_ref(orig_node);
 805 }
 806
 807 /* only send one vis packet. called from send_vis_packets() */
 808 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 809 {
 810         struct hard_iface *primary_if;
 811         struct vis_packet *packet;
 812
 813         primary_if = primary_if_get_selected(bat_priv);
 814         if (!primary_if)
 815                 goto out;
 816
 817         packet = (struct vis_packet *)info->skb_packet->data;
 818         if (packet->ttl < 2) {
 819                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 820                 goto out;
 821         }
 822
 823         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 824         packet->ttl--;
 825
 826         if (is_broadcast_ether_addr(packet->target_orig))
 827                 broadcast_vis_packet(bat_priv, info);
 828         else
 829                 unicast_vis_packet(bat_priv, info);
 830         packet->ttl++; /* restore TTL */
 831
 832 out:
 833         if (primary_if)
 834                 hardif_free_ref(primary_if);
 835 }
 836
 837 /* called from timer; send (and maybe generate) vis packet. */
 838 static void send_vis_packets(struct work_struct *work)
 839 {
 840         struct delayed_work *delayed_work =
 841                 container_of(work, struct delayed_work, work);
 842         struct bat_priv *bat_priv =
 843                 container_of(delayed_work, struct bat_priv, vis_work);
 844         struct vis_info *info;
 845
 846         spin_lock_bh(&bat_priv->vis_hash_lock);
 847         purge_vis_packets(bat_priv);
 848
 849         if (generate_vis_packet(bat_priv) == 0) {
 850                 /* schedule if generation was successful */
 851                 send_list_add(bat_priv, bat_priv->my_vis_info);
 852         }
 853
 854         while (!list_empty(&bat_priv->vis_send_list)) {
 855                 info = list_first_entry(&bat_priv->vis_send_list,
 856                                         typeof(*info), send_list);
 857
 858                 kref_get(&info->refcount);
 859                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 860
 861                 send_vis_packet(bat_priv, info);
 862
 863                 spin_lock_bh(&bat_priv->vis_hash_lock);
 864                 send_list_del(info);
 865                 kref_put(&info->refcount, free_info);
 866         }
 867         spin_unlock_bh(&bat_priv->vis_hash_lock);
 868         start_vis_timer(bat_priv);
 869 }
 870
 871 /* init the vis server. this may only be called when if_list is already
 872  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 873 int vis_init(struct bat_priv *bat_priv)
 874 {
 875         struct vis_packet *packet;
 876         int hash_added;
 877
 878         if (bat_priv->vis_hash)
 879                 return 1;
 880
 881         spin_lock_bh(&bat_priv->vis_hash_lock);
 882
 883         bat_priv->vis_hash = hash_new(256);
 884         if (!bat_priv->vis_hash) {
 885                 pr_err("Can't initialize vis_hash\n");
 886                 goto err;
 887         }
 888
 889         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 890         if (!bat_priv->my_vis_info) {
 891                 pr_err("Can't initialize vis packet\n");
 892                 goto err;
 893         }
 894
 895         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 896                                                           MAX_VIS_PACKET_SIZE +
 897                                                          sizeof(struct ethhdr));
 898         if (!bat_priv->my_vis_info->skb_packet)
 899                 goto free_info;
 900
 901         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 902         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 903                                               sizeof(*packet));
 904
 905         /* prefill the vis info */
 906         bat_priv->my_vis_info->first_seen = jiffies -
 907                                                 msecs_to_jiffies(VIS_INTERVAL);
 908         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 909         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 910         kref_init(&bat_priv->my_vis_info->refcount);
 911         bat_priv->my_vis_info->bat_priv = bat_priv;
 912         packet->version = COMPAT_VERSION;
 913         packet->packet_type = BAT_VIS;
 914         packet->ttl = TTL;
 915         packet->seqno = 0;
 916         packet->entries = 0;
 917
 918         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 919
 920         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 921                               bat_priv->my_vis_info,
 922                               &bat_priv->my_vis_info->hash_entry);
 923         if (hash_added < 0) {
 924                 pr_err("Can't add own vis packet into hash\n");
 925                 /* not in hash, need to remove it manually. */
 926                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 927                 goto err;
 928         }
 929
 930         spin_unlock_bh(&bat_priv->vis_hash_lock);
 931         start_vis_timer(bat_priv);
 932         return 1;
 933
 934 free_info:
 935         kfree(bat_priv->my_vis_info);
 936         bat_priv->my_vis_info = NULL;
 937 err:
 938         spin_unlock_bh(&bat_priv->vis_hash_lock);
 939         vis_quit(bat_priv);
 940         return 0;
 941 }
 942
 943 /* Decrease the reference count on a hash item info */
 944 static void free_info_ref(struct hlist_node *node, void *arg)
 945 {
 946         struct vis_info *info;
 947
 948         info = container_of(node, struct vis_info, hash_entry);
 949         send_list_del(info);
 950         kref_put(&info->refcount, free_info);
 951 }
 952
 953 /* shutdown vis-server */
 954 void vis_quit(struct bat_priv *bat_priv)
 955 {
 956         if (!bat_priv->vis_hash)
 957                 return;
 958
 959         cancel_delayed_work_sync(&bat_priv->vis_work);
 960
 961         spin_lock_bh(&bat_priv->vis_hash_lock);
 962         /* properly remove, kill timers ... */
 963         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 964         bat_priv->vis_hash = NULL;
 965         bat_priv->my_vis_info = NULL;
 966         spin_unlock_bh(&bat_priv->vis_hash_lock);
 967 }
 968
 969 /* schedule packets for (re)transmission */
 970 static void start_vis_timer(struct bat_priv *bat_priv)
 971 {
 972         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 973         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 974                            msecs_to_jiffies(VIS_INTERVAL));
 975 }