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 /* Returns the smallest signed integer in two's complement with the sizeof x */
  34 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  35
  36 /* Checks if a sequence number x is a predecessor/successor of y.
  37  * they handle overflows/underflows and can correctly check for a
  38  * predecessor/successor unless the variable sequence number has grown by
  39  * more then 2**(bitwidth(x)-1)-1.
  40  * This means that for a uint8_t with the maximum value 255, it would think:
  41  *  - when adding nothing - it is neither a predecessor nor a successor
  42  *  - before adding more than 127 to the starting value - it is a predecessor,
  43  *  - when adding 128 - it is neither a predecessor nor a successor,
  44  *  - after adding more than 127 to the starting value - it is a successor */
  45 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  46                         _dummy > smallest_signed_int(_dummy); })
  47 #define seq_after(x, y) seq_before(y, x)
  48
  49 static void start_vis_timer(struct bat_priv *bat_priv);
  50
  51 /* free the info */
  52 static void free_info(struct kref *ref)
  53 {
  54         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  55         struct bat_priv *bat_priv = info->bat_priv;
  56         struct recvlist_node *entry, *tmp;
  57
  58         list_del_init(&info->send_list);
  59         spin_lock_bh(&bat_priv->vis_list_lock);
  60         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  61                 list_del(&entry->list);
  62                 kfree(entry);
  63         }
  64
  65         spin_unlock_bh(&bat_priv->vis_list_lock);
  66         kfree_skb(info->skb_packet);
  67         kfree(info);
  68 }
  69
  70 /* Compare two vis packets, used by the hashing algorithm */
  71 static int vis_info_cmp(struct hlist_node *node, void *data2)
  72 {
  73         struct vis_info *d1, *d2;
  74         struct vis_packet *p1, *p2;
  75
  76         d1 = container_of(node, struct vis_info, hash_entry);
  77         d2 = data2;
  78         p1 = (struct vis_packet *)d1->skb_packet->data;
  79         p2 = (struct vis_packet *)d2->skb_packet->data;
  80         return compare_eth(p1->vis_orig, p2->vis_orig);
  81 }
  82
  83 /* hash function to choose an entry in a hash table of given size */
  84 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  85 static int vis_info_choose(void *data, int size)
  86 {
  87         struct vis_info *vis_info = data;
  88         struct vis_packet *packet;
  89         unsigned char *key;
  90         uint32_t hash = 0;
  91         size_t i;
  92
  93         packet = (struct vis_packet *)vis_info->skb_packet->data;
  94         key = packet->vis_orig;
  95         for (i = 0; i < ETH_ALEN; i++) {
  96                 hash += key[i];
  97                 hash += (hash << 10);
  98                 hash ^= (hash >> 6);
  99         }
 100
 101         hash += (hash << 3);
 102         hash ^= (hash >> 11);
 103         hash += (hash << 15);
 104
 105         return hash % size;
 106 }
 107
 108 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
 109                                       void *data)
 110 {
 111         struct hashtable_t *hash = bat_priv->vis_hash;
 112         struct hlist_head *head;
 113         struct hlist_node *node;
 114         struct vis_info *vis_info, *vis_info_tmp = NULL;
 115         int index;
 116
 117         if (!hash)
 118                 return NULL;
 119
 120         index = vis_info_choose(data, hash->size);
 121         head = &hash->table[index];
 122
 123         rcu_read_lock();
 124         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 125                 if (!vis_info_cmp(node, data))
 126                         continue;
 127
 128                 vis_info_tmp = vis_info;
 129                 break;
 130         }
 131         rcu_read_unlock();
 132
 133         return vis_info_tmp;
 134 }
 135
 136 /* insert interface to the list of interfaces of one originator, if it
 137  * does not already exist in the list */
 138 static void vis_data_insert_interface(const uint8_t *interface,
 139                                       struct hlist_head *if_list,
 140                                       bool primary)
 141 {
 142         struct if_list_entry *entry;
 143         struct hlist_node *pos;
 144
 145         hlist_for_each_entry(entry, pos, if_list, list) {
 146                 if (compare_eth(entry->addr, (void *)interface))
 147                         return;
 148         }
 149
 150         /* its a new address, add it to the list */
 151         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 152         if (!entry)
 153                 return;
 154         memcpy(entry->addr, interface, ETH_ALEN);
 155         entry->primary = primary;
 156         hlist_add_head(&entry->list, if_list);
 157 }
 158
 159 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
 160 {
 161         struct if_list_entry *entry;
 162         struct hlist_node *pos;
 163         size_t len = 0;
 164
 165         hlist_for_each_entry(entry, pos, if_list, list) {
 166                 if (entry->primary)
 167                         len += sprintf(buff + len, "PRIMARY, ");
 168                 else
 169                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 170         }
 171
 172         return len;
 173 }
 174
 175 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 176 {
 177         struct if_list_entry *entry;
 178         struct hlist_node *pos;
 179         size_t count = 0;
 180
 181         hlist_for_each_entry(entry, pos, if_list, list) {
 182                 if (entry->primary)
 183                         count += 9;
 184                 else
 185                         count += 23;
 186         }
 187
 188         return count;
 189 }
 190
 191 /* read an entry  */
 192 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 193                                    uint8_t *src, bool primary)
 194 {
 195         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 196         if (primary && entry->quality == 0)
 197                 return sprintf(buff, "HNA %pM, ", entry->dest);
 198         else if (compare_eth(entry->src, src))
 199                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 200                                entry->quality);
 201
 202         return 0;
 203 }
 204
 205 int vis_seq_print_text(struct seq_file *seq, void *offset)
 206 {
 207         struct hlist_node *node;
 208         struct hlist_head *head;
 209         struct vis_info *info;
 210         struct vis_packet *packet;
 211         struct vis_info_entry *entries;
 212         struct net_device *net_dev = (struct net_device *)seq->private;
 213         struct bat_priv *bat_priv = netdev_priv(net_dev);
 214         struct hashtable_t *hash = bat_priv->vis_hash;
 215         HLIST_HEAD(vis_if_list);
 216         struct if_list_entry *entry;
 217         struct hlist_node *pos, *n;
 218         int i, j;
 219         int vis_server = atomic_read(&bat_priv->vis_mode);
 220         size_t buff_pos, buf_size;
 221         char *buff;
 222         int compare;
 223
 224         if ((!bat_priv->primary_if) ||
 225             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 226                 return 0;
 227
 228         buf_size = 1;
 229         /* Estimate length */
 230         spin_lock_bh(&bat_priv->vis_hash_lock);
 231         for (i = 0; i < hash->size; i++) {
 232                 head = &hash->table[i];
 233
 234                 rcu_read_lock();
 235                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 236                         packet = (struct vis_packet *)info->skb_packet->data;
 237                         entries = (struct vis_info_entry *)
 238                                 ((char *)packet + sizeof(struct vis_packet));
 239
 240                         for (j = 0; j < packet->entries; j++) {
 241                                 if (entries[j].quality == 0)
 242                                         continue;
 243                                 compare =
 244                                  compare_eth(entries[j].src, packet->vis_orig);
 245                                 vis_data_insert_interface(entries[j].src,
 246                                                           &vis_if_list,
 247                                                           compare);
 248                         }
 249
 250                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 251                                 buf_size += 18 + 26 * packet->entries;
 252
 253                                 /* add primary/secondary records */
 254                                 if (compare_eth(entry->addr, packet->vis_orig))
 255                                         buf_size +=
 256                                           vis_data_count_prim_sec(&vis_if_list);
 257
 258                                 buf_size += 1;
 259                         }
 260
 261                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 262                                                   list) {
 263                                 hlist_del(&entry->list);
 264                                 kfree(entry);
 265                         }
 266                 }
 267                 rcu_read_unlock();
 268         }
 269
 270         buff = kmalloc(buf_size, GFP_ATOMIC);
 271         if (!buff) {
 272                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 273                 return -ENOMEM;
 274         }
 275         buff[0] = '\0';
 276         buff_pos = 0;
 277
 278         for (i = 0; i < hash->size; i++) {
 279                 head = &hash->table[i];
 280
 281                 rcu_read_lock();
 282                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 283                         packet = (struct vis_packet *)info->skb_packet->data;
 284                         entries = (struct vis_info_entry *)
 285                                 ((char *)packet + sizeof(struct vis_packet));
 286
 287                         for (j = 0; j < packet->entries; j++) {
 288                                 if (entries[j].quality == 0)
 289                                         continue;
 290                                 compare =
 291                                  compare_eth(entries[j].src, packet->vis_orig);
 292                                 vis_data_insert_interface(entries[j].src,
 293                                                           &vis_if_list,
 294                                                           compare);
 295                         }
 296
 297                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 298                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 299                                                 entry->addr);
 300
 301                                 for (j = 0; j < packet->entries; j++)
 302                                         buff_pos += vis_data_read_entry(
 303                                                         buff + buff_pos,
 304                                                         &entries[j],
 305                                                         entry->addr,
 306                                                         entry->primary);
 307
 308                                 /* add primary/secondary records */
 309                                 if (compare_eth(entry->addr, packet->vis_orig))
 310                                         buff_pos +=
 311                                          vis_data_read_prim_sec(buff + buff_pos,
 312                                                                 &vis_if_list);
 313
 314                                 buff_pos += sprintf(buff + buff_pos, "\n");
 315                         }
 316
 317                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 318                                                   list) {
 319                                 hlist_del(&entry->list);
 320                                 kfree(entry);
 321                         }
 322                 }
 323                 rcu_read_unlock();
 324         }
 325
 326         spin_unlock_bh(&bat_priv->vis_hash_lock);
 327
 328         seq_printf(seq, "%s", buff);
 329         kfree(buff);
 330
 331         return 0;
 332 }
 333
 334 /* add the info packet to the send list, if it was not
 335  * already linked in. */
 336 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 337 {
 338         if (list_empty(&info->send_list)) {
 339                 kref_get(&info->refcount);
 340                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 341         }
 342 }
 343
 344 /* delete the info packet from the send list, if it was
 345  * linked in. */
 346 static void send_list_del(struct vis_info *info)
 347 {
 348         if (!list_empty(&info->send_list)) {
 349                 list_del_init(&info->send_list);
 350                 kref_put(&info->refcount, free_info);
 351         }
 352 }
 353
 354 /* tries to add one entry to the receive list. */
 355 static void recv_list_add(struct bat_priv *bat_priv,
 356                           struct list_head *recv_list, char *mac)
 357 {
 358         struct recvlist_node *entry;
 359
 360         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 361         if (!entry)
 362                 return;
 363
 364         memcpy(entry->mac, mac, ETH_ALEN);
 365         spin_lock_bh(&bat_priv->vis_list_lock);
 366         list_add_tail(&entry->list, recv_list);
 367         spin_unlock_bh(&bat_priv->vis_list_lock);
 368 }
 369
 370 /* returns 1 if this mac is in the recv_list */
 371 static int recv_list_is_in(struct bat_priv *bat_priv,
 372                            struct list_head *recv_list, char *mac)
 373 {
 374         struct recvlist_node *entry;
 375
 376         spin_lock_bh(&bat_priv->vis_list_lock);
 377         list_for_each_entry(entry, recv_list, list) {
 378                 if (compare_eth(entry->mac, mac)) {
 379                         spin_unlock_bh(&bat_priv->vis_list_lock);
 380                         return 1;
 381                 }
 382         }
 383         spin_unlock_bh(&bat_priv->vis_list_lock);
 384         return 0;
 385 }
 386
 387 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 388  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 389  * is newer than old entries in the hash. */
 390 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 391                                    struct vis_packet *vis_packet,
 392                                    int vis_info_len, int *is_new,
 393                                    int make_broadcast)
 394 {
 395         struct vis_info *info, *old_info;
 396         struct vis_packet *search_packet, *old_packet;
 397         struct vis_info search_elem;
 398         struct vis_packet *packet;
 399         int hash_added;
 400
 401         *is_new = 0;
 402         /* sanity check */
 403         if (!bat_priv->vis_hash)
 404                 return NULL;
 405
 406         /* see if the packet is already in vis_hash */
 407         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
 408         if (!search_elem.skb_packet)
 409                 return NULL;
 410         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 411                                                      sizeof(struct vis_packet));
 412
 413         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 414         old_info = vis_hash_find(bat_priv, &search_elem);
 415         kfree_skb(search_elem.skb_packet);
 416
 417         if (old_info) {
 418                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 419                 if (!seq_after(ntohl(vis_packet->seqno),
 420                                ntohl(old_packet->seqno))) {
 421                         if (old_packet->seqno == vis_packet->seqno) {
 422                                 recv_list_add(bat_priv, &old_info->recv_list,
 423                                               vis_packet->sender_orig);
 424                                 return old_info;
 425                         } else {
 426                                 /* newer packet is already in hash. */
 427                                 return NULL;
 428                         }
 429                 }
 430                 /* remove old entry */
 431                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 432                             old_info);
 433                 send_list_del(old_info);
 434                 kref_put(&old_info->refcount, free_info);
 435         }
 436
 437         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 438         if (!info)
 439                 return NULL;
 440
 441         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 442                                          vis_info_len + sizeof(struct ethhdr));
 443         if (!info->skb_packet) {
 444                 kfree(info);
 445                 return NULL;
 446         }
 447         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 448         packet = (struct vis_packet *)skb_put(info->skb_packet,
 449                                               sizeof(struct vis_packet) +
 450                                               vis_info_len);
 451
 452         kref_init(&info->refcount);
 453         INIT_LIST_HEAD(&info->send_list);
 454         INIT_LIST_HEAD(&info->recv_list);
 455         info->first_seen = jiffies;
 456         info->bat_priv = bat_priv;
 457         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 458
 459         /* initialize and add new packet. */
 460         *is_new = 1;
 461
 462         /* Make it a broadcast packet, if required */
 463         if (make_broadcast)
 464                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 465
 466         /* repair if entries is longer than packet. */
 467         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 468                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 469
 470         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 471
 472         /* try to add it */
 473         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 474                               info, &info->hash_entry);
 475         if (hash_added < 0) {
 476                 /* did not work (for some reason) */
 477                 kref_put(&info->refcount, free_info);
 478                 info = NULL;
 479         }
 480
 481         return info;
 482 }
 483
 484 /* handle the server sync packet, forward if needed. */
 485 void receive_server_sync_packet(struct bat_priv *bat_priv,
 486                                 struct vis_packet *vis_packet,
 487                                 int vis_info_len)
 488 {
 489         struct vis_info *info;
 490         int is_new, make_broadcast;
 491         int vis_server = atomic_read(&bat_priv->vis_mode);
 492
 493         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 494
 495         spin_lock_bh(&bat_priv->vis_hash_lock);
 496         info = add_packet(bat_priv, vis_packet, vis_info_len,
 497                           &is_new, make_broadcast);
 498         if (!info)
 499                 goto end;
 500
 501         /* only if we are server ourselves and packet is newer than the one in
 502          * hash.*/
 503         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 504                 send_list_add(bat_priv, info);
 505 end:
 506         spin_unlock_bh(&bat_priv->vis_hash_lock);
 507 }
 508
 509 /* handle an incoming client update packet and schedule forward if needed. */
 510 void receive_client_update_packet(struct bat_priv *bat_priv,
 511                                   struct vis_packet *vis_packet,
 512                                   int vis_info_len)
 513 {
 514         struct vis_info *info;
 515         struct vis_packet *packet;
 516         int is_new;
 517         int vis_server = atomic_read(&bat_priv->vis_mode);
 518         int are_target = 0;
 519
 520         /* clients shall not broadcast. */
 521         if (is_broadcast_ether_addr(vis_packet->target_orig))
 522                 return;
 523
 524         /* Are we the target for this VIS packet? */
 525         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 526             is_my_mac(vis_packet->target_orig))
 527                 are_target = 1;
 528
 529         spin_lock_bh(&bat_priv->vis_hash_lock);
 530         info = add_packet(bat_priv, vis_packet, vis_info_len,
 531                           &is_new, are_target);
 532
 533         if (!info)
 534                 goto end;
 535         /* note that outdated packets will be dropped at this point. */
 536
 537         packet = (struct vis_packet *)info->skb_packet->data;
 538
 539         /* send only if we're the target server or ... */
 540         if (are_target && is_new) {
 541                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 542                 send_list_add(bat_priv, info);
 543
 544                 /* ... we're not the recipient (and thus need to forward). */
 545         } else if (!is_my_mac(packet->target_orig)) {
 546                 send_list_add(bat_priv, info);
 547         }
 548
 549 end:
 550         spin_unlock_bh(&bat_priv->vis_hash_lock);
 551 }
 552
 553 /* Walk the originators and find the VIS server with the best tq. Set the packet
 554  * address to its address and return the best_tq.
 555  *
 556  * Must be called with the originator hash locked */
 557 static int find_best_vis_server(struct bat_priv *bat_priv,
 558                                 struct vis_info *info)
 559 {
 560         struct hashtable_t *hash = bat_priv->orig_hash;
 561         struct neigh_node *router;
 562         struct hlist_node *node;
 563         struct hlist_head *head;
 564         struct orig_node *orig_node;
 565         struct vis_packet *packet;
 566         int best_tq = -1, i;
 567
 568         packet = (struct vis_packet *)info->skb_packet->data;
 569
 570         for (i = 0; i < hash->size; i++) {
 571                 head = &hash->table[i];
 572
 573                 rcu_read_lock();
 574                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 575                         router = orig_node_get_router(orig_node);
 576                         if (!router)
 577                                 continue;
 578
 579                         if ((orig_node->flags & VIS_SERVER) &&
 580                             (router->tq_avg > best_tq)) {
 581                                 best_tq = router->tq_avg;
 582                                 memcpy(packet->target_orig, orig_node->orig,
 583                                        ETH_ALEN);
 584                         }
 585                         neigh_node_free_ref(router);
 586                 }
 587                 rcu_read_unlock();
 588         }
 589
 590         return best_tq;
 591 }
 592
 593 /* Return true if the vis packet is full. */
 594 static bool vis_packet_full(struct vis_info *info)
 595 {
 596         struct vis_packet *packet;
 597         packet = (struct vis_packet *)info->skb_packet->data;
 598
 599         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 600                 < packet->entries + 1)
 601                 return true;
 602         return false;
 603 }
 604
 605 /* generates a packet of own vis data,
 606  * returns 0 on success, -1 if no packet could be generated */
 607 static int generate_vis_packet(struct bat_priv *bat_priv)
 608 {
 609         struct hashtable_t *hash = bat_priv->orig_hash;
 610         struct hlist_node *node;
 611         struct hlist_head *head;
 612         struct orig_node *orig_node;
 613         struct neigh_node *router;
 614         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 615         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 616         struct vis_info_entry *entry;
 617         struct hna_local_entry *hna_local_entry;
 618         int best_tq = -1, i;
 619
 620         info->first_seen = jiffies;
 621         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 622
 623         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 624         packet->ttl = TTL;
 625         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 626         packet->entries = 0;
 627         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 628
 629         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 630                 best_tq = find_best_vis_server(bat_priv, info);
 631
 632                 if (best_tq < 0)
 633                         return -1;
 634         }
 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(orig_node, node, head, hash_entry) {
 641                         router = orig_node_get_router(orig_node);
 642                         if (!router)
 643                                 continue;
 644
 645                         if (!compare_eth(router->addr, orig_node->orig))
 646                                 goto next;
 647
 648                         if (router->if_incoming->if_status != IF_ACTIVE)
 649                                 goto next;
 650
 651                         if (router->tq_avg < 1)
 652                                 goto next;
 653
 654                         /* fill one entry into buffer. */
 655                         entry = (struct vis_info_entry *)
 656                                       skb_put(info->skb_packet, sizeof(*entry));
 657                         memcpy(entry->src,
 658                                router->if_incoming->net_dev->dev_addr,
 659                                ETH_ALEN);
 660                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 661                         entry->quality = router->tq_avg;
 662                         packet->entries++;
 663
 664 next:
 665                         neigh_node_free_ref(router);
 666
 667                         if (vis_packet_full(info))
 668                                 goto unlock;
 669                 }
 670                 rcu_read_unlock();
 671         }
 672
 673         hash = bat_priv->hna_local_hash;
 674
 675         spin_lock_bh(&bat_priv->hna_lhash_lock);
 676         for (i = 0; i < hash->size; i++) {
 677                 head = &hash->table[i];
 678
 679                 hlist_for_each_entry(hna_local_entry, node, head, hash_entry) {
 680                         entry = (struct vis_info_entry *)
 681                                         skb_put(info->skb_packet,
 682                                                 sizeof(*entry));
 683                         memset(entry->src, 0, ETH_ALEN);
 684                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 685                         entry->quality = 0; /* 0 means HNA */
 686                         packet->entries++;
 687
 688                         if (vis_packet_full(info)) {
 689                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
 690                                 return 0;
 691                         }
 692                 }
 693         }
 694
 695         spin_unlock_bh(&bat_priv->hna_lhash_lock);
 696         return 0;
 697
 698 unlock:
 699         rcu_read_unlock();
 700         return 0;
 701 }
 702
 703 /* free old vis packets. Must be called with this vis_hash_lock
 704  * held */
 705 static void purge_vis_packets(struct bat_priv *bat_priv)
 706 {
 707         int i;
 708         struct hashtable_t *hash = bat_priv->vis_hash;
 709         struct hlist_node *node, *node_tmp;
 710         struct hlist_head *head;
 711         struct vis_info *info;
 712
 713         for (i = 0; i < hash->size; i++) {
 714                 head = &hash->table[i];
 715
 716                 hlist_for_each_entry_safe(info, node, node_tmp,
 717                                           head, hash_entry) {
 718                         /* never purge own data. */
 719                         if (info == bat_priv->my_vis_info)
 720                                 continue;
 721
 722                         if (time_after(jiffies,
 723                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 724                                 hlist_del(node);
 725                                 send_list_del(info);
 726                                 kref_put(&info->refcount, free_info);
 727                         }
 728                 }
 729         }
 730 }
 731
 732 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 733                                  struct vis_info *info)
 734 {
 735         struct neigh_node *router;
 736         struct hashtable_t *hash = bat_priv->orig_hash;
 737         struct hlist_node *node;
 738         struct hlist_head *head;
 739         struct orig_node *orig_node;
 740         struct vis_packet *packet;
 741         struct sk_buff *skb;
 742         struct hard_iface *hard_iface;
 743         uint8_t dstaddr[ETH_ALEN];
 744         int i;
 745
 746
 747         packet = (struct vis_packet *)info->skb_packet->data;
 748
 749         /* send to all routers in range. */
 750         for (i = 0; i < hash->size; i++) {
 751                 head = &hash->table[i];
 752
 753                 rcu_read_lock();
 754                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 755                         /* if it's a vis server and reachable, send it. */
 756                         if (!(orig_node->flags & VIS_SERVER))
 757                                 continue;
 758
 759                         router = orig_node_get_router(orig_node);
 760                         if (!router)
 761                                 continue;
 762
 763                         /* don't send it if we already received the packet from
 764                          * this node. */
 765                         if (recv_list_is_in(bat_priv, &info->recv_list,
 766                                             orig_node->orig)) {
 767                                 neigh_node_free_ref(router);
 768                                 continue;
 769                         }
 770
 771                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 772                         hard_iface = router->if_incoming;
 773                         memcpy(dstaddr, router->addr, ETH_ALEN);
 774
 775                         neigh_node_free_ref(router);
 776
 777                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 778                         if (skb)
 779                                 send_skb_packet(skb, hard_iface, dstaddr);
 780
 781                 }
 782                 rcu_read_unlock();
 783         }
 784 }
 785
 786 static void unicast_vis_packet(struct bat_priv *bat_priv,
 787                                struct vis_info *info)
 788 {
 789         struct orig_node *orig_node;
 790         struct neigh_node *router = NULL;
 791         struct sk_buff *skb;
 792         struct vis_packet *packet;
 793
 794         packet = (struct vis_packet *)info->skb_packet->data;
 795
 796         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 797         if (!orig_node)
 798                 goto out;
 799
 800         router = orig_node_get_router(orig_node);
 801         if (!router)
 802                 goto out;
 803
 804         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 805         if (skb)
 806                 send_skb_packet(skb, router->if_incoming, router->addr);
 807
 808 out:
 809         if (router)
 810                 neigh_node_free_ref(router);
 811         if (orig_node)
 812                 orig_node_free_ref(orig_node);
 813 }
 814
 815 /* only send one vis packet. called from send_vis_packets() */
 816 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 817 {
 818         struct vis_packet *packet;
 819
 820         packet = (struct vis_packet *)info->skb_packet->data;
 821         if (packet->ttl < 2) {
 822                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 823                 return;
 824         }
 825
 826         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 827                ETH_ALEN);
 828         packet->ttl--;
 829
 830         if (is_broadcast_ether_addr(packet->target_orig))
 831                 broadcast_vis_packet(bat_priv, info);
 832         else
 833                 unicast_vis_packet(bat_priv, info);
 834         packet->ttl++; /* restore TTL */
 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                 if (bat_priv->primary_if)
 862                         send_vis_packet(bat_priv, info);
 863
 864                 spin_lock_bh(&bat_priv->vis_hash_lock);
 865                 send_list_del(info);
 866                 kref_put(&info->refcount, free_info);
 867         }
 868         spin_unlock_bh(&bat_priv->vis_hash_lock);
 869         start_vis_timer(bat_priv);
 870 }
 871
 872 /* init the vis server. this may only be called when if_list is already
 873  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 874 int vis_init(struct bat_priv *bat_priv)
 875 {
 876         struct vis_packet *packet;
 877         int hash_added;
 878
 879         if (bat_priv->vis_hash)
 880                 return 1;
 881
 882         spin_lock_bh(&bat_priv->vis_hash_lock);
 883
 884         bat_priv->vis_hash = hash_new(256);
 885         if (!bat_priv->vis_hash) {
 886                 pr_err("Can't initialize vis_hash\n");
 887                 goto err;
 888         }
 889
 890         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 891         if (!bat_priv->my_vis_info) {
 892                 pr_err("Can't initialize vis packet\n");
 893                 goto err;
 894         }
 895
 896         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 897                                                 sizeof(struct vis_packet) +
 898                                                 MAX_VIS_PACKET_SIZE +
 899                                                 sizeof(struct ethhdr));
 900         if (!bat_priv->my_vis_info->skb_packet)
 901                 goto free_info;
 902
 903         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 904         packet = (struct vis_packet *)skb_put(
 905                                         bat_priv->my_vis_info->skb_packet,
 906                                         sizeof(struct vis_packet));
 907
 908         /* prefill the vis info */
 909         bat_priv->my_vis_info->first_seen = jiffies -
 910                                                 msecs_to_jiffies(VIS_INTERVAL);
 911         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 912         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 913         kref_init(&bat_priv->my_vis_info->refcount);
 914         bat_priv->my_vis_info->bat_priv = bat_priv;
 915         packet->version = COMPAT_VERSION;
 916         packet->packet_type = BAT_VIS;
 917         packet->ttl = TTL;
 918         packet->seqno = 0;
 919         packet->entries = 0;
 920
 921         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 922
 923         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 924                               bat_priv->my_vis_info,
 925                               &bat_priv->my_vis_info->hash_entry);
 926         if (hash_added < 0) {
 927                 pr_err("Can't add own vis packet into hash\n");
 928                 /* not in hash, need to remove it manually. */
 929                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 930                 goto err;
 931         }
 932
 933         spin_unlock_bh(&bat_priv->vis_hash_lock);
 934         start_vis_timer(bat_priv);
 935         return 1;
 936
 937 free_info:
 938         kfree(bat_priv->my_vis_info);
 939         bat_priv->my_vis_info = NULL;
 940 err:
 941         spin_unlock_bh(&bat_priv->vis_hash_lock);
 942         vis_quit(bat_priv);
 943         return 0;
 944 }
 945
 946 /* Decrease the reference count on a hash item info */
 947 static void free_info_ref(struct hlist_node *node, void *arg)
 948 {
 949         struct vis_info *info;
 950
 951         info = container_of(node, struct vis_info, hash_entry);
 952         send_list_del(info);
 953         kref_put(&info->refcount, free_info);
 954 }
 955
 956 /* shutdown vis-server */
 957 void vis_quit(struct bat_priv *bat_priv)
 958 {
 959         if (!bat_priv->vis_hash)
 960                 return;
 961
 962         cancel_delayed_work_sync(&bat_priv->vis_work);
 963
 964         spin_lock_bh(&bat_priv->vis_hash_lock);
 965         /* properly remove, kill timers ... */
 966         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 967         bat_priv->vis_hash = NULL;
 968         bat_priv->my_vis_info = NULL;
 969         spin_unlock_bh(&bat_priv->vis_hash_lock);
 970 }
 971
 972 /* schedule packets for (re)transmission */
 973 static void start_vis_timer(struct bat_priv *bat_priv)
 974 {
 975         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 976         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 977                            msecs_to_jiffies(VIS_INTERVAL));
 978 }