net/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 #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 }
  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         size_t len = 0;
 134
 135         hlist_for_each_entry(entry, pos, if_list, list) {
 136                 if (entry->primary)
 137                         len += sprintf(buff + len, "PRIMARY, ");
 138                 else
 139                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 140         }
 141
 142         return len;
 143 }
 144
 145 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 146 {
 147         struct if_list_entry *entry;
 148         struct hlist_node *pos;
 149         size_t count = 0;
 150
 151         hlist_for_each_entry(entry, pos, if_list, list) {
 152                 if (entry->primary)
 153                         count += 9;
 154                 else
 155                         count += 23;
 156         }
 157
 158         return count;
 159 }
 160
 161 /* read an entry  */
 162 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 163                                    uint8_t *src, bool primary)
 164 {
 165         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 166         if (primary && entry->quality == 0)
 167                 return sprintf(buff, "HNA %pM, ", entry->dest);
 168         else if (compare_orig(entry->src, src))
 169                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 170                                entry->quality);
 171
 172         return 0;
 173 }
 174
 175 int vis_seq_print_text(struct seq_file *seq, void *offset)
 176 {
 177         struct hlist_node *walk;
 178         struct hlist_head *head;
 179         struct element_t *bucket;
 180         struct vis_info *info;
 181         struct vis_packet *packet;
 182         struct vis_info_entry *entries;
 183         struct net_device *net_dev = (struct net_device *)seq->private;
 184         struct bat_priv *bat_priv = netdev_priv(net_dev);
 185         struct hashtable_t *hash = bat_priv->vis_hash;
 186         HLIST_HEAD(vis_if_list);
 187         struct if_list_entry *entry;
 188         struct hlist_node *pos, *n;
 189         int i, j;
 190         int vis_server = atomic_read(&bat_priv->vis_mode);
 191         size_t buff_pos, buf_size;
 192         char *buff;
 193         int compare;
 194
 195         if ((!bat_priv->primary_if) ||
 196             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 197                 return 0;
 198
 199         buf_size = 1;
 200         /* Estimate length */
 201         spin_lock_bh(&bat_priv->vis_hash_lock);
 202         for (i = 0; i < hash->size; i++) {
 203                 head = &hash->table[i];
 204
 205                 hlist_for_each_entry(bucket, walk, head, hlist) {
 206                         info = bucket->data;
 207                         packet = (struct vis_packet *)info->skb_packet->data;
 208                         entries = (struct vis_info_entry *)
 209                                 ((char *)packet + sizeof(struct vis_packet));
 210
 211                         for (j = 0; j < packet->entries; j++) {
 212                                 if (entries[j].quality == 0)
 213                                         continue;
 214                                 compare =
 215                                  compare_orig(entries[j].src, packet->vis_orig);
 216                                 vis_data_insert_interface(entries[j].src,
 217                                                           &vis_if_list,
 218                                                           compare);
 219                         }
 220
 221                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 222                                 buf_size += 18 + 26 * packet->entries;
 223
 224                                 /* add primary/secondary records */
 225                                 if (compare_orig(entry->addr, packet->vis_orig))
 226                                         buf_size +=
 227                                           vis_data_count_prim_sec(&vis_if_list);
 228
 229                                 buf_size += 1;
 230                         }
 231
 232                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 233                                                   list) {
 234                                 hlist_del(&entry->list);
 235                                 kfree(entry);
 236                         }
 237                 }
 238         }
 239
 240         buff = kmalloc(buf_size, GFP_ATOMIC);
 241         if (!buff) {
 242                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 243                 return -ENOMEM;
 244         }
 245         buff[0] = '\0';
 246         buff_pos = 0;
 247
 248         for (i = 0; i < hash->size; i++) {
 249                 head = &hash->table[i];
 250
 251                 hlist_for_each_entry(bucket, walk, head, hlist) {
 252                         info = bucket->data;
 253                         packet = (struct vis_packet *)info->skb_packet->data;
 254                         entries = (struct vis_info_entry *)
 255                                 ((char *)packet + sizeof(struct vis_packet));
 256
 257                         for (j = 0; j < packet->entries; j++) {
 258                                 if (entries[j].quality == 0)
 259                                         continue;
 260                                 compare =
 261                                  compare_orig(entries[j].src, packet->vis_orig);
 262                                 vis_data_insert_interface(entries[j].src,
 263                                                           &vis_if_list,
 264                                                           compare);
 265                         }
 266
 267                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 268                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 269                                                 entry->addr);
 270
 271                                 for (i = 0; i < packet->entries; i++)
 272                                         buff_pos += vis_data_read_entry(
 273                                                         buff + buff_pos,
 274                                                         &entries[i],
 275                                                         entry->addr,
 276                                                         entry->primary);
 277
 278                                 /* add primary/secondary records */
 279                                 if (compare_orig(entry->addr, packet->vis_orig))
 280                                         buff_pos +=
 281                                          vis_data_read_prim_sec(buff + buff_pos,
 282                                                                 &vis_if_list);
 283
 284                                 buff_pos += sprintf(buff + buff_pos, "\n");
 285                         }
 286
 287                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 288                                                   list) {
 289                                 hlist_del(&entry->list);
 290                                 kfree(entry);
 291                         }
 292                 }
 293         }
 294
 295         spin_unlock_bh(&bat_priv->vis_hash_lock);
 296
 297         seq_printf(seq, "%s", buff);
 298         kfree(buff);
 299
 300         return 0;
 301 }
 302
 303 /* add the info packet to the send list, if it was not
 304  * already linked in. */
 305 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 306 {
 307         if (list_empty(&info->send_list)) {
 308                 kref_get(&info->refcount);
 309                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 310         }
 311 }
 312
 313 /* delete the info packet from the send list, if it was
 314  * linked in. */
 315 static void send_list_del(struct vis_info *info)
 316 {
 317         if (!list_empty(&info->send_list)) {
 318                 list_del_init(&info->send_list);
 319                 kref_put(&info->refcount, free_info);
 320         }
 321 }
 322
 323 /* tries to add one entry to the receive list. */
 324 static void recv_list_add(struct bat_priv *bat_priv,
 325                           struct list_head *recv_list, char *mac)
 326 {
 327         struct recvlist_node *entry;
 328
 329         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 330         if (!entry)
 331                 return;
 332
 333         memcpy(entry->mac, mac, ETH_ALEN);
 334         spin_lock_bh(&bat_priv->vis_list_lock);
 335         list_add_tail(&entry->list, recv_list);
 336         spin_unlock_bh(&bat_priv->vis_list_lock);
 337 }
 338
 339 /* returns 1 if this mac is in the recv_list */
 340 static int recv_list_is_in(struct bat_priv *bat_priv,
 341                            struct list_head *recv_list, char *mac)
 342 {
 343         struct recvlist_node *entry;
 344
 345         spin_lock_bh(&bat_priv->vis_list_lock);
 346         list_for_each_entry(entry, recv_list, list) {
 347                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
 348                         spin_unlock_bh(&bat_priv->vis_list_lock);
 349                         return 1;
 350                 }
 351         }
 352         spin_unlock_bh(&bat_priv->vis_list_lock);
 353         return 0;
 354 }
 355
 356 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 357  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 358  * is newer than old entries in the hash. */
 359 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 360                                    struct vis_packet *vis_packet,
 361                                    int vis_info_len, int *is_new,
 362                                    int make_broadcast)
 363 {
 364         struct vis_info *info, *old_info;
 365         struct vis_packet *search_packet, *old_packet;
 366         struct vis_info search_elem;
 367         struct vis_packet *packet;
 368         int hash_added;
 369
 370         *is_new = 0;
 371         /* sanity check */
 372         if (!bat_priv->vis_hash)
 373                 return NULL;
 374
 375         /* see if the packet is already in vis_hash */
 376         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
 377         if (!search_elem.skb_packet)
 378                 return NULL;
 379         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 380                                                      sizeof(struct vis_packet));
 381
 382         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 383         old_info = hash_find(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 384                              &search_elem);
 385         kfree_skb(search_elem.skb_packet);
 386
 387         if (old_info) {
 388                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 389                 if (!seq_after(ntohl(vis_packet->seqno),
 390                                ntohl(old_packet->seqno))) {
 391                         if (old_packet->seqno == vis_packet->seqno) {
 392                                 recv_list_add(bat_priv, &old_info->recv_list,
 393                                               vis_packet->sender_orig);
 394                                 return old_info;
 395                         } else {
 396                                 /* newer packet is already in hash. */
 397                                 return NULL;
 398                         }
 399                 }
 400                 /* remove old entry */
 401                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 402                             old_info);
 403                 send_list_del(old_info);
 404                 kref_put(&old_info->refcount, free_info);
 405         }
 406
 407         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 408         if (!info)
 409                 return NULL;
 410
 411         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 412                                          vis_info_len + sizeof(struct ethhdr));
 413         if (!info->skb_packet) {
 414                 kfree(info);
 415                 return NULL;
 416         }
 417         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 418         packet = (struct vis_packet *)skb_put(info->skb_packet,
 419                                               sizeof(struct vis_packet) +
 420                                               vis_info_len);
 421
 422         kref_init(&info->refcount);
 423         INIT_LIST_HEAD(&info->send_list);
 424         INIT_LIST_HEAD(&info->recv_list);
 425         info->first_seen = jiffies;
 426         info->bat_priv = bat_priv;
 427         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 428
 429         /* initialize and add new packet. */
 430         *is_new = 1;
 431
 432         /* Make it a broadcast packet, if required */
 433         if (make_broadcast)
 434                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 435
 436         /* repair if entries is longer than packet. */
 437         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 438                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 439
 440         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 441
 442         /* try to add it */
 443         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 444                               info);
 445         if (hash_added < 0) {
 446                 /* did not work (for some reason) */
 447                 kref_put(&old_info->refcount, free_info);
 448                 info = NULL;
 449         }
 450
 451         return info;
 452 }
 453
 454 /* handle the server sync packet, forward if needed. */
 455 void receive_server_sync_packet(struct bat_priv *bat_priv,
 456                                 struct vis_packet *vis_packet,
 457                                 int vis_info_len)
 458 {
 459         struct vis_info *info;
 460         int is_new, make_broadcast;
 461         int vis_server = atomic_read(&bat_priv->vis_mode);
 462
 463         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 464
 465         spin_lock_bh(&bat_priv->vis_hash_lock);
 466         info = add_packet(bat_priv, vis_packet, vis_info_len,
 467                           &is_new, make_broadcast);
 468         if (!info)
 469                 goto end;
 470
 471         /* only if we are server ourselves and packet is newer than the one in
 472          * hash.*/
 473         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 474                 send_list_add(bat_priv, info);
 475 end:
 476         spin_unlock_bh(&bat_priv->vis_hash_lock);
 477 }
 478
 479 /* handle an incoming client update packet and schedule forward if needed. */
 480 void receive_client_update_packet(struct bat_priv *bat_priv,
 481                                   struct vis_packet *vis_packet,
 482                                   int vis_info_len)
 483 {
 484         struct vis_info *info;
 485         struct vis_packet *packet;
 486         int is_new;
 487         int vis_server = atomic_read(&bat_priv->vis_mode);
 488         int are_target = 0;
 489
 490         /* clients shall not broadcast. */
 491         if (is_broadcast_ether_addr(vis_packet->target_orig))
 492                 return;
 493
 494         /* Are we the target for this VIS packet? */
 495         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 496             is_my_mac(vis_packet->target_orig))
 497                 are_target = 1;
 498
 499         spin_lock_bh(&bat_priv->vis_hash_lock);
 500         info = add_packet(bat_priv, vis_packet, vis_info_len,
 501                           &is_new, are_target);
 502
 503         if (!info)
 504                 goto end;
 505         /* note that outdated packets will be dropped at this point. */
 506
 507         packet = (struct vis_packet *)info->skb_packet->data;
 508
 509         /* send only if we're the target server or ... */
 510         if (are_target && is_new) {
 511                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 512                 send_list_add(bat_priv, info);
 513
 514                 /* ... we're not the recipient (and thus need to forward). */
 515         } else if (!is_my_mac(packet->target_orig)) {
 516                 send_list_add(bat_priv, info);
 517         }
 518
 519 end:
 520         spin_unlock_bh(&bat_priv->vis_hash_lock);
 521 }
 522
 523 /* Walk the originators and find the VIS server with the best tq. Set the packet
 524  * address to its address and return the best_tq.
 525  *
 526  * Must be called with the originator hash locked */
 527 static int find_best_vis_server(struct bat_priv *bat_priv,
 528                                 struct vis_info *info)
 529 {
 530         struct hashtable_t *hash = bat_priv->orig_hash;
 531         struct hlist_node *walk;
 532         struct hlist_head *head;
 533         struct element_t *bucket;
 534         struct orig_node *orig_node;
 535         struct vis_packet *packet;
 536         int best_tq = -1, i;
 537
 538         packet = (struct vis_packet *)info->skb_packet->data;
 539
 540         for (i = 0; i < hash->size; i++) {
 541                 head = &hash->table[i];
 542
 543                 hlist_for_each_entry(bucket, walk, head, hlist) {
 544                         orig_node = bucket->data;
 545                         if ((orig_node) && (orig_node->router) &&
 546                         (orig_node->flags & VIS_SERVER) &&
 547                         (orig_node->router->tq_avg > best_tq)) {
 548                                 best_tq = orig_node->router->tq_avg;
 549                                 memcpy(packet->target_orig, orig_node->orig,
 550                                        ETH_ALEN);
 551                         }
 552                 }
 553         }
 554
 555         return best_tq;
 556 }
 557
 558 /* Return true if the vis packet is full. */
 559 static bool vis_packet_full(struct vis_info *info)
 560 {
 561         struct vis_packet *packet;
 562         packet = (struct vis_packet *)info->skb_packet->data;
 563
 564         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 565                 < packet->entries + 1)
 566                 return true;
 567         return false;
 568 }
 569
 570 /* generates a packet of own vis data,
 571  * returns 0 on success, -1 if no packet could be generated */
 572 static int generate_vis_packet(struct bat_priv *bat_priv)
 573 {
 574         struct hashtable_t *hash = bat_priv->orig_hash;
 575         struct hlist_node *walk;
 576         struct hlist_head *head;
 577         struct element_t *bucket;
 578         struct orig_node *orig_node;
 579         struct neigh_node *neigh_node;
 580         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 581         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 582         struct vis_info_entry *entry;
 583         struct hna_local_entry *hna_local_entry;
 584         int best_tq = -1, i;
 585
 586         info->first_seen = jiffies;
 587         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 588
 589         spin_lock_bh(&bat_priv->orig_hash_lock);
 590         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 591         packet->ttl = TTL;
 592         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 593         packet->entries = 0;
 594         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 595
 596         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 597                 best_tq = find_best_vis_server(bat_priv, info);
 598
 599                 if (best_tq < 0) {
 600                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 601                         return -1;
 602                 }
 603         }
 604
 605         for (i = 0; i < hash->size; i++) {
 606                 head = &hash->table[i];
 607
 608                 hlist_for_each_entry(bucket, walk, head, hlist) {
 609                         orig_node = bucket->data;
 610                         neigh_node = orig_node->router;
 611
 612                         if (!neigh_node)
 613                                 continue;
 614
 615                         if (!compare_orig(neigh_node->addr, orig_node->orig))
 616                                 continue;
 617
 618                         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
 619                                 continue;
 620
 621                         if (neigh_node->tq_avg < 1)
 622                                 continue;
 623
 624                         /* fill one entry into buffer. */
 625                         entry = (struct vis_info_entry *)
 626                                       skb_put(info->skb_packet, sizeof(*entry));
 627                         memcpy(entry->src,
 628                                neigh_node->if_incoming->net_dev->dev_addr,
 629                                ETH_ALEN);
 630                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 631                         entry->quality = neigh_node->tq_avg;
 632                         packet->entries++;
 633
 634                         if (vis_packet_full(info)) {
 635                                 spin_unlock_bh(&bat_priv->orig_hash_lock);
 636                                 return 0;
 637                         }
 638                 }
 639         }
 640
 641         spin_unlock_bh(&bat_priv->orig_hash_lock);
 642
 643         hash = bat_priv->hna_local_hash;
 644
 645         spin_lock_bh(&bat_priv->hna_lhash_lock);
 646         for (i = 0; i < hash->size; i++) {
 647                 head = &hash->table[i];
 648
 649                 hlist_for_each_entry(bucket, walk, head, hlist) {
 650                         hna_local_entry = bucket->data;
 651                         entry = (struct vis_info_entry *)
 652                                         skb_put(info->skb_packet,
 653                                                 sizeof(*entry));
 654                         memset(entry->src, 0, ETH_ALEN);
 655                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 656                         entry->quality = 0; /* 0 means HNA */
 657                         packet->entries++;
 658
 659                         if (vis_packet_full(info)) {
 660                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
 661                                 return 0;
 662                         }
 663                 }
 664         }
 665
 666         spin_unlock_bh(&bat_priv->hna_lhash_lock);
 667         return 0;
 668 }
 669
 670 /* free old vis packets. Must be called with this vis_hash_lock
 671  * held */
 672 static void purge_vis_packets(struct bat_priv *bat_priv)
 673 {
 674         int i;
 675         struct hashtable_t *hash = bat_priv->vis_hash;
 676         struct hlist_node *walk, *safe;
 677         struct hlist_head *head;
 678         struct element_t *bucket;
 679         struct vis_info *info;
 680
 681         for (i = 0; i < hash->size; i++) {
 682                 head = &hash->table[i];
 683
 684                 hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
 685                         info = bucket->data;
 686
 687                         /* never purge own data. */
 688                         if (info == bat_priv->my_vis_info)
 689                                 continue;
 690
 691                         if (time_after(jiffies,
 692                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 693                                 hlist_del(walk);
 694                                 kfree(bucket);
 695                                 send_list_del(info);
 696                                 kref_put(&info->refcount, free_info);
 697                         }
 698                 }
 699         }
 700 }
 701
 702 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 703                                  struct vis_info *info)
 704 {
 705         struct hashtable_t *hash = bat_priv->orig_hash;
 706         struct hlist_node *walk;
 707         struct hlist_head *head;
 708         struct element_t *bucket;
 709         struct orig_node *orig_node;
 710         struct vis_packet *packet;
 711         struct sk_buff *skb;
 712         struct batman_if *batman_if;
 713         uint8_t dstaddr[ETH_ALEN];
 714         int i;
 715
 716
 717         spin_lock_bh(&bat_priv->orig_hash_lock);
 718         packet = (struct vis_packet *)info->skb_packet->data;
 719
 720         /* send to all routers in range. */
 721         for (i = 0; i < hash->size; i++) {
 722                 head = &hash->table[i];
 723
 724                 hlist_for_each_entry(bucket, walk, head, hlist) {
 725                         orig_node = bucket->data;
 726
 727                         /* if it's a vis server and reachable, send it. */
 728                         if ((!orig_node) || (!orig_node->router))
 729                                 continue;
 730                         if (!(orig_node->flags & VIS_SERVER))
 731                                 continue;
 732                         /* don't send it if we already received the packet from
 733                         * this node. */
 734                         if (recv_list_is_in(bat_priv, &info->recv_list,
 735                                             orig_node->orig))
 736                                 continue;
 737
 738                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 739                         batman_if = orig_node->router->if_incoming;
 740                         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 741                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 742
 743                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 744                         if (skb)
 745                                 send_skb_packet(skb, batman_if, dstaddr);
 746
 747                         spin_lock_bh(&bat_priv->orig_hash_lock);
 748                 }
 749
 750         }
 751
 752         spin_unlock_bh(&bat_priv->orig_hash_lock);
 753 }
 754
 755 static void unicast_vis_packet(struct bat_priv *bat_priv,
 756                                struct vis_info *info)
 757 {
 758         struct orig_node *orig_node;
 759         struct sk_buff *skb;
 760         struct vis_packet *packet;
 761         struct batman_if *batman_if;
 762         uint8_t dstaddr[ETH_ALEN];
 763
 764         spin_lock_bh(&bat_priv->orig_hash_lock);
 765         packet = (struct vis_packet *)info->skb_packet->data;
 766         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 767                                                    compare_orig, choose_orig,
 768                                                    packet->target_orig));
 769
 770         if ((!orig_node) || (!orig_node->router))
 771                 goto out;
 772
 773         /* don't lock while sending the packets ... we therefore
 774          * copy the required data before sending */
 775         batman_if = orig_node->router->if_incoming;
 776         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 777         spin_unlock_bh(&bat_priv->orig_hash_lock);
 778
 779         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 780         if (skb)
 781                 send_skb_packet(skb, batman_if, dstaddr);
 782
 783         return;
 784
 785 out:
 786         spin_unlock_bh(&bat_priv->orig_hash_lock);
 787 }
 788
 789 /* only send one vis packet. called from send_vis_packets() */
 790 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 791 {
 792         struct vis_packet *packet;
 793
 794         packet = (struct vis_packet *)info->skb_packet->data;
 795         if (packet->ttl < 2) {
 796                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 797                 return;
 798         }
 799
 800         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 801                ETH_ALEN);
 802         packet->ttl--;
 803
 804         if (is_broadcast_ether_addr(packet->target_orig))
 805                 broadcast_vis_packet(bat_priv, info);
 806         else
 807                 unicast_vis_packet(bat_priv, info);
 808         packet->ttl++; /* restore TTL */
 809 }
 810
 811 /* called from timer; send (and maybe generate) vis packet. */
 812 static void send_vis_packets(struct work_struct *work)
 813 {
 814         struct delayed_work *delayed_work =
 815                 container_of(work, struct delayed_work, work);
 816         struct bat_priv *bat_priv =
 817                 container_of(delayed_work, struct bat_priv, vis_work);
 818         struct vis_info *info, *temp;
 819
 820         spin_lock_bh(&bat_priv->vis_hash_lock);
 821         purge_vis_packets(bat_priv);
 822
 823         if (generate_vis_packet(bat_priv) == 0) {
 824                 /* schedule if generation was successful */
 825                 send_list_add(bat_priv, bat_priv->my_vis_info);
 826         }
 827
 828         list_for_each_entry_safe(info, temp, &bat_priv->vis_send_list,
 829                                  send_list) {
 830
 831                 kref_get(&info->refcount);
 832                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 833
 834                 if (bat_priv->primary_if)
 835                         send_vis_packet(bat_priv, info);
 836
 837                 spin_lock_bh(&bat_priv->vis_hash_lock);
 838                 send_list_del(info);
 839                 kref_put(&info->refcount, free_info);
 840         }
 841         spin_unlock_bh(&bat_priv->vis_hash_lock);
 842         start_vis_timer(bat_priv);
 843 }
 844
 845 /* init the vis server. this may only be called when if_list is already
 846  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 847 int vis_init(struct bat_priv *bat_priv)
 848 {
 849         struct vis_packet *packet;
 850         int hash_added;
 851
 852         if (bat_priv->vis_hash)
 853                 return 1;
 854
 855         spin_lock_bh(&bat_priv->vis_hash_lock);
 856
 857         bat_priv->vis_hash = hash_new(256);
 858         if (!bat_priv->vis_hash) {
 859                 pr_err("Can't initialize vis_hash\n");
 860                 goto err;
 861         }
 862
 863         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 864         if (!bat_priv->my_vis_info) {
 865                 pr_err("Can't initialize vis packet\n");
 866                 goto err;
 867         }
 868
 869         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 870                                                 sizeof(struct vis_packet) +
 871                                                 MAX_VIS_PACKET_SIZE +
 872                                                 sizeof(struct ethhdr));
 873         if (!bat_priv->my_vis_info->skb_packet)
 874                 goto free_info;
 875
 876         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 877         packet = (struct vis_packet *)skb_put(
 878                                         bat_priv->my_vis_info->skb_packet,
 879                                         sizeof(struct vis_packet));
 880
 881         /* prefill the vis info */
 882         bat_priv->my_vis_info->first_seen = jiffies -
 883                                                 msecs_to_jiffies(VIS_INTERVAL);
 884         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 885         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 886         kref_init(&bat_priv->my_vis_info->refcount);
 887         bat_priv->my_vis_info->bat_priv = bat_priv;
 888         packet->version = COMPAT_VERSION;
 889         packet->packet_type = BAT_VIS;
 890         packet->ttl = TTL;
 891         packet->seqno = 0;
 892         packet->entries = 0;
 893
 894         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 895
 896         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 897                               bat_priv->my_vis_info);
 898         if (hash_added < 0) {
 899                 pr_err("Can't add own vis packet into hash\n");
 900                 /* not in hash, need to remove it manually. */
 901                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 902                 goto err;
 903         }
 904
 905         spin_unlock_bh(&bat_priv->vis_hash_lock);
 906         start_vis_timer(bat_priv);
 907         return 1;
 908
 909 free_info:
 910         kfree(bat_priv->my_vis_info);
 911         bat_priv->my_vis_info = NULL;
 912 err:
 913         spin_unlock_bh(&bat_priv->vis_hash_lock);
 914         vis_quit(bat_priv);
 915         return 0;
 916 }
 917
 918 /* Decrease the reference count on a hash item info */
 919 static void free_info_ref(void *data, void *arg)
 920 {
 921         struct vis_info *info = data;
 922
 923         send_list_del(info);
 924         kref_put(&info->refcount, free_info);
 925 }
 926
 927 /* shutdown vis-server */
 928 void vis_quit(struct bat_priv *bat_priv)
 929 {
 930         if (!bat_priv->vis_hash)
 931                 return;
 932
 933         cancel_delayed_work_sync(&bat_priv->vis_work);
 934
 935         spin_lock_bh(&bat_priv->vis_hash_lock);
 936         /* properly remove, kill timers ... */
 937         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 938         bat_priv->vis_hash = NULL;
 939         bat_priv->my_vis_info = NULL;
 940         spin_unlock_bh(&bat_priv->vis_hash_lock);
 941 }
 942
 943 /* schedule packets for (re)transmission */
 944 static void start_vis_timer(struct bat_priv *bat_priv)
 945 {
 946         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 947         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 948                            msecs_to_jiffies(VIS_INTERVAL));
 949 }