drivers/staging/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2010 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
  30 #define MAX_VIS_PACKET_SIZE 1000
  31
  32 /* Returns the smallest signed integer in two's complement with the sizeof x */
  33 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  34
  35 /* Checks if a sequence number x is a predecessor/successor of y.
  36    they handle overflows/underflows and can correctly check for a
  37    predecessor/successor unless the variable sequence number has grown by
  38    more then 2**(bitwidth(x)-1)-1.
  39    This means that for a uint8_t with the maximum value 255, it would think:
  40     * when adding nothing - it is neither a predecessor nor a successor
  41     * before adding more than 127 to the starting value - it is a predecessor,
  42     * when adding 128 - it is neither a predecessor nor a successor,
  43     * after adding more than 127 to the starting value - it is a successor */
  44 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  45                         _dummy > smallest_signed_int(_dummy); })
  46 #define seq_after(x, y) seq_before(y, x)
  47
  48 static void start_vis_timer(struct bat_priv *bat_priv);
  49
  50 /* free the info */
  51 static void free_info(struct kref *ref)
  52 {
  53         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  54         struct bat_priv *bat_priv = info->bat_priv;
  55         struct recvlist_node *entry, *tmp;
  56         unsigned long flags;
  57
  58         list_del_init(&info->send_list);
  59         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
  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_irqrestore(&bat_priv->vis_list_lock, flags);
  66         kfree_skb(info->skb_packet);
  67 }
  68
  69 /* Compare two vis packets, used by the hashing algorithm */
  70 static int vis_info_cmp(void *data1, void *data2)
  71 {
  72         struct vis_info *d1, *d2;
  73         struct vis_packet *p1, *p2;
  74         d1 = data1;
  75         d2 = data2;
  76         p1 = (struct vis_packet *)d1->skb_packet->data;
  77         p2 = (struct vis_packet *)d2->skb_packet->data;
  78         return compare_orig(p1->vis_orig, p2->vis_orig);
  79 }
  80
  81 /* hash function to choose an entry in a hash table of given size */
  82 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  83 static int vis_info_choose(void *data, int size)
  84 {
  85         struct vis_info *vis_info = data;
  86         struct vis_packet *packet;
  87         unsigned char *key;
  88         uint32_t hash = 0;
  89         size_t i;
  90
  91         packet = (struct vis_packet *)vis_info->skb_packet->data;
  92         key = packet->vis_orig;
  93         for (i = 0; i < ETH_ALEN; i++) {
  94                 hash += key[i];
  95                 hash += (hash << 10);
  96                 hash ^= (hash >> 6);
  97         }
  98
  99         hash += (hash << 3);
 100         hash ^= (hash >> 11);
 101         hash += (hash << 15);
 102
 103         return hash % size;
 104 }
 105
 106 /* insert interface to the list of interfaces of one originator, if it
 107  * does not already exist in the list */
 108 static void vis_data_insert_interface(const uint8_t *interface,
 109                                       struct hlist_head *if_list,
 110                                       bool primary)
 111 {
 112         struct if_list_entry *entry;
 113         struct hlist_node *pos;
 114
 115         hlist_for_each_entry(entry, pos, if_list, list) {
 116                 if (compare_orig(entry->addr, (void *)interface))
 117                         return;
 118         }
 119
 120         /* its a new address, add it to the list */
 121         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 122         if (!entry)
 123                 return;
 124         memcpy(entry->addr, interface, ETH_ALEN);
 125         entry->primary = primary;
 126         hlist_add_head(&entry->list, if_list);
 127 }
 128
 129 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
 130 {
 131         struct if_list_entry *entry;
 132         struct hlist_node *pos;
 133         char tmp_addr_str[ETH_STR_LEN];
 134         size_t len = 0;
 135
 136         hlist_for_each_entry(entry, pos, if_list, list) {
 137                 if (entry->primary)
 138                         len += sprintf(buff + len, "PRIMARY, ");
 139                 else {
 140                         addr_to_string(tmp_addr_str, entry->addr);
 141                         len += sprintf(buff + len,  "SEC %s, ", tmp_addr_str);
 142                 }
 143         }
 144
 145         return len;
 146 }
 147
 148 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 149 {
 150         struct if_list_entry *entry;
 151         struct hlist_node *pos;
 152         size_t count = 0;
 153
 154         hlist_for_each_entry(entry, pos, if_list, list) {
 155                 if (entry->primary)
 156                         count += 9;
 157                 else
 158                         count += 23;
 159         }
 160
 161         return count;
 162 }
 163
 164 /* read an entry  */
 165 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 166                                    uint8_t *src, bool primary)
 167 {
 168         char to[18];
 169
 170         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 171         addr_to_string(to, entry->dest);
 172         if (primary && entry->quality == 0)
 173                 return sprintf(buff, "HNA %s, ", to);
 174         else if (compare_orig(entry->src, src))
 175                 return sprintf(buff, "TQ %s %d, ", to, entry->quality);
 176
 177         return 0;
 178 }
 179
 180 int vis_seq_print_text(struct seq_file *seq, void *offset)
 181 {
 182         HASHIT(hashit);
 183         HASHIT(hashit_count);
 184         struct vis_info *info;
 185         struct vis_packet *packet;
 186         struct vis_info_entry *entries;
 187         struct net_device *net_dev = (struct net_device *)seq->private;
 188         struct bat_priv *bat_priv = netdev_priv(net_dev);
 189         HLIST_HEAD(vis_if_list);
 190         struct if_list_entry *entry;
 191         struct hlist_node *pos, *n;
 192         int i;
 193         char tmp_addr_str[ETH_STR_LEN];
 194         unsigned long flags;
 195         int vis_server = atomic_read(&bat_priv->vis_mode);
 196         size_t buff_pos, buf_size;
 197         char *buff;
 198
 199         if ((!bat_priv->primary_if) ||
 200             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 201                 return 0;
 202
 203         buf_size = 1;
 204         /* Estimate length */
 205         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 206         while (hash_iterate(bat_priv->vis_hash, &hashit_count)) {
 207                 info = hashit_count.bucket->data;
 208                 packet = (struct vis_packet *)info->skb_packet->data;
 209                 entries = (struct vis_info_entry *)
 210                           ((char *)packet + sizeof(struct vis_packet));
 211
 212                 for (i = 0; i < packet->entries; i++) {
 213                         if (entries[i].quality == 0)
 214                                 continue;
 215                         vis_data_insert_interface(entries[i].src, &vis_if_list,
 216                                 compare_orig(entries[i].src, packet->vis_orig));
 217                 }
 218
 219                 hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 220                         buf_size += 18 + 26 * packet->entries;
 221
 222                         /* add primary/secondary records */
 223                         if (compare_orig(entry->addr, packet->vis_orig))
 224                                 buf_size +=
 225                                         vis_data_count_prim_sec(&vis_if_list);
 226
 227                         buf_size += 1;
 228                 }
 229
 230                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 231                         hlist_del(&entry->list);
 232                         kfree(entry);
 233                 }
 234         }
 235
 236         buff = kmalloc(buf_size, GFP_ATOMIC);
 237         if (!buff) {
 238                 spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 239                 return -ENOMEM;
 240         }
 241         buff[0] = '\0';
 242         buff_pos = 0;
 243
 244         while (hash_iterate(bat_priv->vis_hash, &hashit)) {
 245                 info = hashit.bucket->data;
 246                 packet = (struct vis_packet *)info->skb_packet->data;
 247                 entries = (struct vis_info_entry *)
 248                           ((char *)packet + sizeof(struct vis_packet));
 249
 250                 for (i = 0; i < packet->entries; i++) {
 251                         if (entries[i].quality == 0)
 252                                 continue;
 253                         vis_data_insert_interface(entries[i].src, &vis_if_list,
 254                                 compare_orig(entries[i].src, packet->vis_orig));
 255                 }
 256
 257                 hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 258                         addr_to_string(tmp_addr_str, entry->addr);
 259                         buff_pos += sprintf(buff + buff_pos, "%s,",
 260                                             tmp_addr_str);
 261
 262                         for (i = 0; i < packet->entries; i++)
 263                                 buff_pos += vis_data_read_entry(buff + buff_pos,
 264                                                                 &entries[i],
 265                                                                 entry->addr,
 266                                                                 entry->primary);
 267
 268                         /* add primary/secondary records */
 269                         if (compare_orig(entry->addr, packet->vis_orig))
 270                                 buff_pos +=
 271                                         vis_data_read_prim_sec(buff + buff_pos,
 272                                                                &vis_if_list);
 273
 274                         buff_pos += sprintf(buff + buff_pos, "\n");
 275                 }
 276
 277                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 278                         hlist_del(&entry->list);
 279                         kfree(entry);
 280                 }
 281         }
 282
 283         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 284
 285         seq_printf(seq, "%s", buff);
 286         kfree(buff);
 287
 288         return 0;
 289 }
 290
 291 /* add the info packet to the send list, if it was not
 292  * already linked in. */
 293 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 294 {
 295         if (list_empty(&info->send_list)) {
 296                 kref_get(&info->refcount);
 297                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 298         }
 299 }
 300
 301 /* delete the info packet from the send list, if it was
 302  * linked in. */
 303 static void send_list_del(struct vis_info *info)
 304 {
 305         if (!list_empty(&info->send_list)) {
 306                 list_del_init(&info->send_list);
 307                 kref_put(&info->refcount, free_info);
 308         }
 309 }
 310
 311 /* tries to add one entry to the receive list. */
 312 static void recv_list_add(struct bat_priv *bat_priv,
 313                           struct list_head *recv_list, char *mac)
 314 {
 315         struct recvlist_node *entry;
 316         unsigned long flags;
 317
 318         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 319         if (!entry)
 320                 return;
 321
 322         memcpy(entry->mac, mac, ETH_ALEN);
 323         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
 324         list_add_tail(&entry->list, recv_list);
 325         spin_unlock_irqrestore(&bat_priv->vis_list_lock, flags);
 326 }
 327
 328 /* returns 1 if this mac is in the recv_list */
 329 static int recv_list_is_in(struct bat_priv *bat_priv,
 330                            struct list_head *recv_list, char *mac)
 331 {
 332         struct recvlist_node *entry;
 333         unsigned long flags;
 334
 335         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
 336         list_for_each_entry(entry, recv_list, list) {
 337                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
 338                         spin_unlock_irqrestore(&bat_priv->vis_list_lock,
 339                                                flags);
 340                         return 1;
 341                 }
 342         }
 343         spin_unlock_irqrestore(&bat_priv->vis_list_lock, flags);
 344         return 0;
 345 }
 346
 347 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 348  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 349  * is newer than old entries in the hash. */
 350 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 351                                    struct vis_packet *vis_packet,
 352                                    int vis_info_len, int *is_new,
 353                                    int make_broadcast)
 354 {
 355         struct vis_info *info, *old_info;
 356         struct vis_packet *search_packet, *old_packet;
 357         struct vis_info search_elem;
 358         struct vis_packet *packet;
 359
 360         *is_new = 0;
 361         /* sanity check */
 362         if (!bat_priv->vis_hash)
 363                 return NULL;
 364
 365         /* see if the packet is already in vis_hash */
 366         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
 367         if (!search_elem.skb_packet)
 368                 return NULL;
 369         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 370                                                      sizeof(struct vis_packet));
 371
 372         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 373         old_info = hash_find(bat_priv->vis_hash, &search_elem);
 374         kfree_skb(search_elem.skb_packet);
 375
 376         if (old_info != NULL) {
 377                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 378                 if (!seq_after(ntohl(vis_packet->seqno),
 379                                ntohl(old_packet->seqno))) {
 380                         if (old_packet->seqno == vis_packet->seqno) {
 381                                 recv_list_add(bat_priv, &old_info->recv_list,
 382                                               vis_packet->sender_orig);
 383                                 return old_info;
 384                         } else {
 385                                 /* newer packet is already in hash. */
 386                                 return NULL;
 387                         }
 388                 }
 389                 /* remove old entry */
 390                 hash_remove(bat_priv->vis_hash, old_info);
 391                 send_list_del(old_info);
 392                 kref_put(&old_info->refcount, free_info);
 393         }
 394
 395         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 396         if (!info)
 397                 return NULL;
 398
 399         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 400                                          vis_info_len + sizeof(struct ethhdr));
 401         if (!info->skb_packet) {
 402                 kfree(info);
 403                 return NULL;
 404         }
 405         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 406         packet = (struct vis_packet *)skb_put(info->skb_packet,
 407                                               sizeof(struct vis_packet) +
 408                                               vis_info_len);
 409
 410         kref_init(&info->refcount);
 411         INIT_LIST_HEAD(&info->send_list);
 412         INIT_LIST_HEAD(&info->recv_list);
 413         info->first_seen = jiffies;
 414         info->bat_priv = bat_priv;
 415         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 416
 417         /* initialize and add new packet. */
 418         *is_new = 1;
 419
 420         /* Make it a broadcast packet, if required */
 421         if (make_broadcast)
 422                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 423
 424         /* repair if entries is longer than packet. */
 425         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 426                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 427
 428         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 429
 430         /* try to add it */
 431         if (hash_add(bat_priv->vis_hash, info) < 0) {
 432                 /* did not work (for some reason) */
 433                 kref_put(&old_info->refcount, free_info);
 434                 info = NULL;
 435         }
 436
 437         return info;
 438 }
 439
 440 /* handle the server sync packet, forward if needed. */
 441 void receive_server_sync_packet(struct bat_priv *bat_priv,
 442                                 struct vis_packet *vis_packet,
 443                                 int vis_info_len)
 444 {
 445         struct vis_info *info;
 446         int is_new, make_broadcast;
 447         unsigned long flags;
 448         int vis_server = atomic_read(&bat_priv->vis_mode);
 449
 450         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 451
 452         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 453         info = add_packet(bat_priv, vis_packet, vis_info_len,
 454                           &is_new, make_broadcast);
 455         if (!info)
 456                 goto end;
 457
 458         /* only if we are server ourselves and packet is newer than the one in
 459          * hash.*/
 460         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 461                 send_list_add(bat_priv, info);
 462 end:
 463         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 464 }
 465
 466 /* handle an incoming client update packet and schedule forward if needed. */
 467 void receive_client_update_packet(struct bat_priv *bat_priv,
 468                                   struct vis_packet *vis_packet,
 469                                   int vis_info_len)
 470 {
 471         struct vis_info *info;
 472         struct vis_packet *packet;
 473         int is_new;
 474         unsigned long flags;
 475         int vis_server = atomic_read(&bat_priv->vis_mode);
 476         int are_target = 0;
 477
 478         /* clients shall not broadcast. */
 479         if (is_bcast(vis_packet->target_orig))
 480                 return;
 481
 482         /* Are we the target for this VIS packet? */
 483         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 484             is_my_mac(vis_packet->target_orig))
 485                 are_target = 1;
 486
 487         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 488         info = add_packet(bat_priv, vis_packet, vis_info_len,
 489                           &is_new, are_target);
 490
 491         if (!info)
 492                 goto end;
 493         /* note that outdated packets will be dropped at this point. */
 494
 495         packet = (struct vis_packet *)info->skb_packet->data;
 496
 497         /* send only if we're the target server or ... */
 498         if (are_target && is_new) {
 499                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 500                 send_list_add(bat_priv, info);
 501
 502                 /* ... we're not the recipient (and thus need to forward). */
 503         } else if (!is_my_mac(packet->target_orig)) {
 504                 send_list_add(bat_priv, info);
 505         }
 506
 507 end:
 508         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 509 }
 510
 511 /* Walk the originators and find the VIS server with the best tq. Set the packet
 512  * address to its address and return the best_tq.
 513  *
 514  * Must be called with the originator hash locked */
 515 static int find_best_vis_server(struct bat_priv *bat_priv,
 516                                 struct vis_info *info)
 517 {
 518         HASHIT(hashit);
 519         struct orig_node *orig_node;
 520         struct vis_packet *packet;
 521         int best_tq = -1;
 522
 523         packet = (struct vis_packet *)info->skb_packet->data;
 524
 525         while (hash_iterate(bat_priv->orig_hash, &hashit)) {
 526                 orig_node = hashit.bucket->data;
 527                 if ((orig_node) && (orig_node->router) &&
 528                     (orig_node->flags & VIS_SERVER) &&
 529                     (orig_node->router->tq_avg > best_tq)) {
 530                         best_tq = orig_node->router->tq_avg;
 531                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 532                 }
 533         }
 534         return best_tq;
 535 }
 536
 537 /* Return true if the vis packet is full. */
 538 static bool vis_packet_full(struct vis_info *info)
 539 {
 540         struct vis_packet *packet;
 541         packet = (struct vis_packet *)info->skb_packet->data;
 542
 543         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 544                 < packet->entries + 1)
 545                 return true;
 546         return false;
 547 }
 548
 549 /* generates a packet of own vis data,
 550  * returns 0 on success, -1 if no packet could be generated */
 551 static int generate_vis_packet(struct bat_priv *bat_priv)
 552 {
 553         HASHIT(hashit_local);
 554         HASHIT(hashit_global);
 555         struct orig_node *orig_node;
 556         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 557         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 558         struct vis_info_entry *entry;
 559         struct hna_local_entry *hna_local_entry;
 560         int best_tq = -1;
 561         unsigned long flags;
 562
 563         info->first_seen = jiffies;
 564         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 565
 566         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 567         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 568         packet->ttl = TTL;
 569         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 570         packet->entries = 0;
 571         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 572
 573         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 574                 best_tq = find_best_vis_server(bat_priv, info);
 575
 576                 if (best_tq < 0) {
 577                         spin_unlock_irqrestore(&bat_priv->orig_hash_lock,
 578                                                flags);
 579                         return -1;
 580                 }
 581         }
 582
 583         while (hash_iterate(bat_priv->orig_hash, &hashit_global)) {
 584                 orig_node = hashit_global.bucket->data;
 585
 586                 if (!orig_node->router)
 587                         continue;
 588
 589                 if (!compare_orig(orig_node->router->addr, orig_node->orig))
 590                         continue;
 591
 592                 if (orig_node->router->if_incoming->if_status != IF_ACTIVE)
 593                         continue;
 594
 595                 if (orig_node->router->tq_avg < 1)
 596                         continue;
 597
 598                 /* fill one entry into buffer. */
 599                 entry = (struct vis_info_entry *)
 600                                 skb_put(info->skb_packet, sizeof(*entry));
 601                 memcpy(entry->src,
 602                        orig_node->router->if_incoming->net_dev->dev_addr,
 603                        ETH_ALEN);
 604                 memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 605                 entry->quality = orig_node->router->tq_avg;
 606                 packet->entries++;
 607
 608                 if (vis_packet_full(info)) {
 609                         spin_unlock_irqrestore(
 610                                         &bat_priv->orig_hash_lock, flags);
 611                         return 0;
 612                 }
 613         }
 614
 615         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 616
 617         spin_lock_irqsave(&bat_priv->hna_lhash_lock, flags);
 618         while (hash_iterate(bat_priv->hna_local_hash, &hashit_local)) {
 619                 hna_local_entry = hashit_local.bucket->data;
 620                 entry = (struct vis_info_entry *)skb_put(info->skb_packet,
 621                                                          sizeof(*entry));
 622                 memset(entry->src, 0, ETH_ALEN);
 623                 memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 624                 entry->quality = 0; /* 0 means HNA */
 625                 packet->entries++;
 626
 627                 if (vis_packet_full(info)) {
 628                         spin_unlock_irqrestore(&bat_priv->hna_lhash_lock,
 629                                                flags);
 630                         return 0;
 631                 }
 632         }
 633
 634         spin_unlock_irqrestore(&bat_priv->hna_lhash_lock, flags);
 635         return 0;
 636 }
 637
 638 /* free old vis packets. Must be called with this vis_hash_lock
 639  * held */
 640 static void purge_vis_packets(struct bat_priv *bat_priv)
 641 {
 642         HASHIT(hashit);
 643         struct vis_info *info;
 644
 645         while (hash_iterate(bat_priv->vis_hash, &hashit)) {
 646                 info = hashit.bucket->data;
 647
 648                 /* never purge own data. */
 649                 if (info == bat_priv->my_vis_info)
 650                         continue;
 651
 652                 if (time_after(jiffies,
 653                                info->first_seen + VIS_TIMEOUT * HZ)) {
 654                         hash_remove_bucket(bat_priv->vis_hash, &hashit);
 655                         send_list_del(info);
 656                         kref_put(&info->refcount, free_info);
 657                 }
 658         }
 659 }
 660
 661 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 662                                  struct vis_info *info)
 663 {
 664         HASHIT(hashit);
 665         struct orig_node *orig_node;
 666         struct vis_packet *packet;
 667         struct sk_buff *skb;
 668         unsigned long flags;
 669         struct batman_if *batman_if;
 670         uint8_t dstaddr[ETH_ALEN];
 671
 672
 673         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 674         packet = (struct vis_packet *)info->skb_packet->data;
 675
 676         /* send to all routers in range. */
 677         while (hash_iterate(bat_priv->orig_hash, &hashit)) {
 678                 orig_node = hashit.bucket->data;
 679
 680                 /* if it's a vis server and reachable, send it. */
 681                 if ((!orig_node) || (!orig_node->router))
 682                         continue;
 683                 if (!(orig_node->flags & VIS_SERVER))
 684                         continue;
 685                 /* don't send it if we already received the packet from
 686                  * this node. */
 687                 if (recv_list_is_in(bat_priv, &info->recv_list,
 688                                                         orig_node->orig))
 689                         continue;
 690
 691                 memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 692                 batman_if = orig_node->router->if_incoming;
 693                 memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 694                 spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 695
 696                 skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 697                 if (skb)
 698                         send_skb_packet(skb, batman_if, dstaddr);
 699
 700                 spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 701
 702         }
 703
 704         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 705 }
 706
 707 static void unicast_vis_packet(struct bat_priv *bat_priv,
 708                                struct vis_info *info)
 709 {
 710         struct orig_node *orig_node;
 711         struct sk_buff *skb;
 712         struct vis_packet *packet;
 713         unsigned long flags;
 714         struct batman_if *batman_if;
 715         uint8_t dstaddr[ETH_ALEN];
 716
 717         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 718         packet = (struct vis_packet *)info->skb_packet->data;
 719         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 720                                                    packet->target_orig));
 721
 722         if ((!orig_node) || (!orig_node->router))
 723                 goto out;
 724
 725         /* don't lock while sending the packets ... we therefore
 726          * copy the required data before sending */
 727         batman_if = orig_node->router->if_incoming;
 728         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 729         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 730
 731         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 732         if (skb)
 733                 send_skb_packet(skb, batman_if, dstaddr);
 734
 735         return;
 736
 737 out:
 738         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 739 }
 740
 741 /* only send one vis packet. called from send_vis_packets() */
 742 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 743 {
 744         struct vis_packet *packet;
 745
 746         packet = (struct vis_packet *)info->skb_packet->data;
 747         if (packet->ttl < 2) {
 748                 pr_warning("Error - can't send vis packet: ttl exceeded\n");
 749                 return;
 750         }
 751
 752         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 753                ETH_ALEN);
 754         packet->ttl--;
 755
 756         if (is_bcast(packet->target_orig))
 757                 broadcast_vis_packet(bat_priv, info);
 758         else
 759                 unicast_vis_packet(bat_priv, info);
 760         packet->ttl++; /* restore TTL */
 761 }
 762
 763 /* called from timer; send (and maybe generate) vis packet. */
 764 static void send_vis_packets(struct work_struct *work)
 765 {
 766         struct delayed_work *delayed_work =
 767                 container_of(work, struct delayed_work, work);
 768         struct bat_priv *bat_priv =
 769                 container_of(delayed_work, struct bat_priv, vis_work);
 770         struct vis_info *info, *temp;
 771         unsigned long flags;
 772
 773         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 774         purge_vis_packets(bat_priv);
 775
 776         if (generate_vis_packet(bat_priv) == 0) {
 777                 /* schedule if generation was successful */
 778                 send_list_add(bat_priv, bat_priv->my_vis_info);
 779         }
 780
 781         list_for_each_entry_safe(info, temp, &bat_priv->vis_send_list,
 782                                  send_list) {
 783
 784                 kref_get(&info->refcount);
 785                 spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 786
 787                 if (bat_priv->primary_if)
 788                         send_vis_packet(bat_priv, info);
 789
 790                 spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 791                 send_list_del(info);
 792                 kref_put(&info->refcount, free_info);
 793         }
 794         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 795         start_vis_timer(bat_priv);
 796 }
 797
 798 /* init the vis server. this may only be called when if_list is already
 799  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 800 int vis_init(struct bat_priv *bat_priv)
 801 {
 802         struct vis_packet *packet;
 803         unsigned long flags;
 804
 805         if (bat_priv->vis_hash)
 806                 return 1;
 807
 808         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 809
 810         bat_priv->vis_hash = hash_new(256, vis_info_cmp, vis_info_choose);
 811         if (!bat_priv->vis_hash) {
 812                 pr_err("Can't initialize vis_hash\n");
 813                 goto err;
 814         }
 815
 816         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 817         if (!bat_priv->my_vis_info) {
 818                 pr_err("Can't initialize vis packet\n");
 819                 goto err;
 820         }
 821
 822         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 823                                                 sizeof(struct vis_packet) +
 824                                                 MAX_VIS_PACKET_SIZE +
 825                                                 sizeof(struct ethhdr));
 826         if (!bat_priv->my_vis_info->skb_packet)
 827                 goto free_info;
 828
 829         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 830         packet = (struct vis_packet *)skb_put(
 831                                         bat_priv->my_vis_info->skb_packet,
 832                                         sizeof(struct vis_packet));
 833
 834         /* prefill the vis info */
 835         bat_priv->my_vis_info->first_seen = jiffies -
 836                                                 msecs_to_jiffies(VIS_INTERVAL);
 837         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 838         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 839         kref_init(&bat_priv->my_vis_info->refcount);
 840         bat_priv->my_vis_info->bat_priv = bat_priv;
 841         packet->version = COMPAT_VERSION;
 842         packet->packet_type = BAT_VIS;
 843         packet->ttl = TTL;
 844         packet->seqno = 0;
 845         packet->entries = 0;
 846
 847         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 848
 849         if (hash_add(bat_priv->vis_hash, bat_priv->my_vis_info) < 0) {
 850                 pr_err("Can't add own vis packet into hash\n");
 851                 /* not in hash, need to remove it manually. */
 852                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 853                 goto err;
 854         }
 855
 856         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 857         start_vis_timer(bat_priv);
 858         return 1;
 859
 860 free_info:
 861         kfree(bat_priv->my_vis_info);
 862         bat_priv->my_vis_info = NULL;
 863 err:
 864         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 865         vis_quit(bat_priv);
 866         return 0;
 867 }
 868
 869 /* Decrease the reference count on a hash item info */
 870 static void free_info_ref(void *data, void *arg)
 871 {
 872         struct vis_info *info = data;
 873
 874         send_list_del(info);
 875         kref_put(&info->refcount, free_info);
 876 }
 877
 878 /* shutdown vis-server */
 879 void vis_quit(struct bat_priv *bat_priv)
 880 {
 881         unsigned long flags;
 882         if (!bat_priv->vis_hash)
 883                 return;
 884
 885         cancel_delayed_work_sync(&bat_priv->vis_work);
 886
 887         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 888         /* properly remove, kill timers ... */
 889         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 890         bat_priv->vis_hash = NULL;
 891         bat_priv->my_vis_info = NULL;
 892         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 893 }
 894
 895 /* schedule packets for (re)transmission */
 896 static void start_vis_timer(struct bat_priv *bat_priv)
 897 {
 898         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 899         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 900                            msecs_to_jiffies(VIS_INTERVAL));
 901 }