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 /* Returns the smallest signed integer in two's complement with the sizeof x */
  31 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  32
  33 /* Checks if a sequence number x is a predecessor/successor of y.
  34    they handle overflows/underflows and can correctly check for a
  35    predecessor/successor unless the variable sequence number has grown by
  36    more then 2**(bitwidth(x)-1)-1.
  37    This means that for a uint8_t with the maximum value 255, it would think:
  38     * when adding nothing - it is neither a predecessor nor a successor
  39     * before adding more than 127 to the starting value - it is a predecessor,
  40     * when adding 128 - it is neither a predecessor nor a successor,
  41     * after adding more than 127 to the starting value - it is a successor */
  42 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  43                         _dummy > smallest_signed_int(_dummy); })
  44 #define seq_after(x, y) seq_before(y, x)
  45
  46 struct hashtable_t *vis_hash;
  47 DEFINE_SPINLOCK(vis_hash_lock);
  48 static DEFINE_SPINLOCK(recv_list_lock);
  49 static struct vis_info *my_vis_info;
  50 static struct list_head send_list;      /* always locked with vis_hash_lock */
  51
  52 static void start_vis_timer(void);
  53
  54 /* free the info */
  55 static void free_info(struct kref *ref)
  56 {
  57         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  58         struct recvlist_node *entry, *tmp;
  59         unsigned long flags;
  60
  61         list_del_init(&info->send_list);
  62         spin_lock_irqsave(&recv_list_lock, flags);
  63         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  64                 list_del(&entry->list);
  65                 kfree(entry);
  66         }
  67         spin_unlock_irqrestore(&recv_list_lock, flags);
  68         kfree(info);
  69 }
  70
  71 /* Compare two vis packets, used by the hashing algorithm */
  72 static int vis_info_cmp(void *data1, void *data2)
  73 {
  74         struct vis_info *d1, *d2;
  75         d1 = data1;
  76         d2 = data2;
  77         return compare_orig(d1->packet.vis_orig, d2->packet.vis_orig);
  78 }
  79
  80 /* hash function to choose an entry in a hash table of given size */
  81 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  82 static int vis_info_choose(void *data, int size)
  83 {
  84         struct vis_info *vis_info = data;
  85         unsigned char *key;
  86         uint32_t hash = 0;
  87         size_t i;
  88
  89         key = vis_info->packet.vis_orig;
  90         for (i = 0; i < ETH_ALEN; i++) {
  91                 hash += key[i];
  92                 hash += (hash << 10);
  93                 hash ^= (hash >> 6);
  94         }
  95
  96         hash += (hash << 3);
  97         hash ^= (hash >> 11);
  98         hash += (hash << 15);
  99
 100         return hash % size;
 101 }
 102
 103 /* insert interface to the list of interfaces of one originator, if it
 104  * does not already exist in the list */
 105 static void vis_data_insert_interface(const uint8_t *interface,
 106                                       struct hlist_head *if_list,
 107                                       bool primary)
 108 {
 109         struct if_list_entry *entry;
 110         struct hlist_node *pos;
 111
 112         hlist_for_each_entry(entry, pos, if_list, list) {
 113                 if (compare_orig(entry->addr, (void *)interface))
 114                         return;
 115         }
 116
 117         /* its a new address, add it to the list */
 118         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 119         if (!entry)
 120                 return;
 121         memcpy(entry->addr, interface, ETH_ALEN);
 122         entry->primary = primary;
 123         hlist_add_head(&entry->list, if_list);
 124 }
 125
 126 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
 127 {
 128         struct if_list_entry *entry;
 129         struct hlist_node *pos;
 130         char tmp_addr_str[ETH_STR_LEN];
 131         size_t len = 0;
 132
 133         hlist_for_each_entry(entry, pos, if_list, list) {
 134                 if (entry->primary)
 135                         len += sprintf(buff + len, "PRIMARY, ");
 136                 else {
 137                         addr_to_string(tmp_addr_str, entry->addr);
 138                         len += sprintf(buff + len,  "SEC %s, ", tmp_addr_str);
 139                 }
 140         }
 141
 142         return len;
 143 }
 144
 145 /* read an entry  */
 146 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 147                                    uint8_t *src, bool primary)
 148 {
 149         char to[40];
 150
 151         addr_to_string(to, entry->dest);
 152         if (primary && entry->quality == 0)
 153                 return sprintf(buff, "HNA %s, ", to);
 154         else if (compare_orig(entry->src, src))
 155                 return sprintf(buff, "TQ %s %d, ", to, entry->quality);
 156
 157         return 0;
 158 }
 159
 160 ssize_t vis_fill_buffer_text(struct net_device *net_dev, char *buff,
 161                               size_t count, loff_t off)
 162 {
 163         HASHIT(hashit);
 164         struct vis_info *info;
 165         struct vis_info_entry *entries;
 166         struct bat_priv *bat_priv = netdev_priv(net_dev);
 167         HLIST_HEAD(vis_if_list);
 168         struct if_list_entry *entry;
 169         struct hlist_node *pos, *n;
 170         size_t hdr_len, tmp_len;
 171         int i, bytes_written = 0;
 172         char tmp_addr_str[ETH_STR_LEN];
 173         unsigned long flags;
 174         int vis_server = atomic_read(&bat_priv->vis_mode);
 175
 176         if ((!bat_priv->primary_if) ||
 177             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 178                 return 0;
 179
 180         hdr_len = 0;
 181
 182         spin_lock_irqsave(&vis_hash_lock, flags);
 183         while (hash_iterate(vis_hash, &hashit)) {
 184                 info = hashit.bucket->data;
 185                 entries = (struct vis_info_entry *)
 186                         ((char *)info + sizeof(struct vis_info));
 187
 188                 /* estimated line length */
 189                 if (count < bytes_written + 200)
 190                         break;
 191
 192                 for (i = 0; i < info->packet.entries; i++) {
 193                         if (entries[i].quality == 0)
 194                                 continue;
 195                         vis_data_insert_interface(entries[i].src, &vis_if_list,
 196                                 compare_orig(entries[i].src,
 197                                                 info->packet.vis_orig));
 198                 }
 199
 200                 hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 201                         addr_to_string(tmp_addr_str, entry->addr);
 202                         tmp_len = sprintf(buff + bytes_written,
 203                                           "%s,", tmp_addr_str);
 204
 205                         for (i = 0; i < info->packet.entries; i++)
 206                                 tmp_len += vis_data_read_entry(
 207                                                 buff + bytes_written + tmp_len,
 208                                                 &entries[i], entry->addr,
 209                                                 entry->primary);
 210
 211                         /* add primary/secondary records */
 212                         if (compare_orig(entry->addr, info->packet.vis_orig))
 213                                 tmp_len += vis_data_read_prim_sec(
 214                                                 buff + bytes_written + tmp_len,
 215                                                 &vis_if_list);
 216
 217                         tmp_len += sprintf(buff + bytes_written + tmp_len,
 218                                           "\n");
 219
 220                         hdr_len += tmp_len;
 221
 222                         if (off >= hdr_len)
 223                                 continue;
 224
 225                         bytes_written += tmp_len;
 226                 }
 227
 228                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 229                         hlist_del(&entry->list);
 230                         kfree(entry);
 231                 }
 232         }
 233         spin_unlock_irqrestore(&vis_hash_lock, flags);
 234
 235         return bytes_written;
 236 }
 237
 238 /* add the info packet to the send list, if it was not
 239  * already linked in. */
 240 static void send_list_add(struct vis_info *info)
 241 {
 242         if (list_empty(&info->send_list)) {
 243                 kref_get(&info->refcount);
 244                 list_add_tail(&info->send_list, &send_list);
 245         }
 246 }
 247
 248 /* delete the info packet from the send list, if it was
 249  * linked in. */
 250 static void send_list_del(struct vis_info *info)
 251 {
 252         if (!list_empty(&info->send_list)) {
 253                 list_del_init(&info->send_list);
 254                 kref_put(&info->refcount, free_info);
 255         }
 256 }
 257
 258 /* tries to add one entry to the receive list. */
 259 static void recv_list_add(struct list_head *recv_list, char *mac)
 260 {
 261         struct recvlist_node *entry;
 262         unsigned long flags;
 263
 264         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 265         if (!entry)
 266                 return;
 267
 268         memcpy(entry->mac, mac, ETH_ALEN);
 269         spin_lock_irqsave(&recv_list_lock, flags);
 270         list_add_tail(&entry->list, recv_list);
 271         spin_unlock_irqrestore(&recv_list_lock, flags);
 272 }
 273
 274 /* returns 1 if this mac is in the recv_list */
 275 static int recv_list_is_in(struct list_head *recv_list, char *mac)
 276 {
 277         struct recvlist_node *entry;
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&recv_list_lock, flags);
 281         list_for_each_entry(entry, recv_list, list) {
 282                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
 283                         spin_unlock_irqrestore(&recv_list_lock, flags);
 284                         return 1;
 285                 }
 286         }
 287         spin_unlock_irqrestore(&recv_list_lock, flags);
 288         return 0;
 289 }
 290
 291 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 292  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 293  * is newer than old entries in the hash. */
 294 static struct vis_info *add_packet(struct vis_packet *vis_packet,
 295                                    int vis_info_len, int *is_new,
 296                                    int make_broadcast)
 297 {
 298         struct vis_info *info, *old_info;
 299         struct vis_info search_elem;
 300
 301         *is_new = 0;
 302         /* sanity check */
 303         if (vis_hash == NULL)
 304                 return NULL;
 305
 306         /* see if the packet is already in vis_hash */
 307         memcpy(search_elem.packet.vis_orig, vis_packet->vis_orig, ETH_ALEN);
 308         old_info = hash_find(vis_hash, &search_elem);
 309
 310         if (old_info != NULL) {
 311                 if (!seq_after(vis_packet->seqno, old_info->packet.seqno)) {
 312                         if (old_info->packet.seqno == vis_packet->seqno) {
 313                                 recv_list_add(&old_info->recv_list,
 314                                               vis_packet->sender_orig);
 315                                 return old_info;
 316                         } else {
 317                                 /* newer packet is already in hash. */
 318                                 return NULL;
 319                         }
 320                 }
 321                 /* remove old entry */
 322                 hash_remove(vis_hash, old_info);
 323                 send_list_del(old_info);
 324                 kref_put(&old_info->refcount, free_info);
 325         }
 326
 327         info = kmalloc(sizeof(struct vis_info) + vis_info_len, GFP_ATOMIC);
 328         if (info == NULL)
 329                 return NULL;
 330
 331         kref_init(&info->refcount);
 332         INIT_LIST_HEAD(&info->send_list);
 333         INIT_LIST_HEAD(&info->recv_list);
 334         info->first_seen = jiffies;
 335         memcpy(&info->packet, vis_packet,
 336                sizeof(struct vis_packet) + vis_info_len);
 337
 338         /* initialize and add new packet. */
 339         *is_new = 1;
 340
 341         /* Make it a broadcast packet, if required */
 342         if (make_broadcast)
 343                 memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);
 344
 345         /* repair if entries is longer than packet. */
 346         if (info->packet.entries * sizeof(struct vis_info_entry) > vis_info_len)
 347                 info->packet.entries = vis_info_len /
 348                         sizeof(struct vis_info_entry);
 349
 350         recv_list_add(&info->recv_list, info->packet.sender_orig);
 351
 352         /* try to add it */
 353         if (hash_add(vis_hash, info) < 0) {
 354                 /* did not work (for some reason) */
 355                 kref_put(&old_info->refcount, free_info);
 356                 info = NULL;
 357         }
 358
 359         return info;
 360 }
 361
 362 /* handle the server sync packet, forward if needed. */
 363 void receive_server_sync_packet(struct bat_priv *bat_priv,
 364                                 struct vis_packet *vis_packet,
 365                                 int vis_info_len)
 366 {
 367         struct vis_info *info;
 368         int is_new, make_broadcast;
 369         unsigned long flags;
 370         int vis_server = atomic_read(&bat_priv->vis_mode);
 371
 372         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 373
 374         spin_lock_irqsave(&vis_hash_lock, flags);
 375         info = add_packet(vis_packet, vis_info_len, &is_new, make_broadcast);
 376         if (info == NULL)
 377                 goto end;
 378
 379         /* only if we are server ourselves and packet is newer than the one in
 380          * hash.*/
 381         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 382                 send_list_add(info);
 383 end:
 384         spin_unlock_irqrestore(&vis_hash_lock, flags);
 385 }
 386
 387 /* handle an incoming client update packet and schedule forward if needed. */
 388 void receive_client_update_packet(struct bat_priv *bat_priv,
 389                                   struct vis_packet *vis_packet,
 390                                   int vis_info_len)
 391 {
 392         struct vis_info *info;
 393         int is_new;
 394         unsigned long flags;
 395         int vis_server = atomic_read(&bat_priv->vis_mode);
 396         int are_target = 0;
 397
 398         /* clients shall not broadcast. */
 399         if (is_bcast(vis_packet->target_orig))
 400                 return;
 401
 402         /* Are we the target for this VIS packet? */
 403         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 404             is_my_mac(vis_packet->target_orig))
 405                 are_target = 1;
 406
 407         spin_lock_irqsave(&vis_hash_lock, flags);
 408         info = add_packet(vis_packet, vis_info_len, &is_new, are_target);
 409         if (info == NULL)
 410                 goto end;
 411         /* note that outdated packets will be dropped at this point. */
 412
 413
 414         /* send only if we're the target server or ... */
 415         if (are_target && is_new) {
 416                 info->packet.vis_type = VIS_TYPE_SERVER_SYNC;   /* upgrade! */
 417                 send_list_add(info);
 418
 419                 /* ... we're not the recipient (and thus need to forward). */
 420         } else if (!is_my_mac(info->packet.target_orig)) {
 421                 send_list_add(info);
 422         }
 423 end:
 424         spin_unlock_irqrestore(&vis_hash_lock, flags);
 425 }
 426
 427 /* Walk the originators and find the VIS server with the best tq. Set the packet
 428  * address to its address and return the best_tq.
 429  *
 430  * Must be called with the originator hash locked */
 431 static int find_best_vis_server(struct vis_info *info)
 432 {
 433         HASHIT(hashit);
 434         struct orig_node *orig_node;
 435         int best_tq = -1;
 436
 437         while (hash_iterate(orig_hash, &hashit)) {
 438                 orig_node = hashit.bucket->data;
 439                 if ((orig_node != NULL) &&
 440                     (orig_node->router != NULL) &&
 441                     (orig_node->flags & VIS_SERVER) &&
 442                     (orig_node->router->tq_avg > best_tq)) {
 443                         best_tq = orig_node->router->tq_avg;
 444                         memcpy(info->packet.target_orig, orig_node->orig,
 445                                ETH_ALEN);
 446                 }
 447         }
 448         return best_tq;
 449 }
 450
 451 /* Return true if the vis packet is full. */
 452 static bool vis_packet_full(struct vis_info *info)
 453 {
 454         if (info->packet.entries + 1 >
 455             (1000 - sizeof(struct vis_info)) / sizeof(struct vis_info_entry))
 456                 return true;
 457         return false;
 458 }
 459
 460 /* generates a packet of own vis data,
 461  * returns 0 on success, -1 if no packet could be generated */
 462 static int generate_vis_packet(struct bat_priv *bat_priv)
 463 {
 464         HASHIT(hashit_local);
 465         HASHIT(hashit_global);
 466         struct orig_node *orig_node;
 467         struct vis_info *info = (struct vis_info *)my_vis_info;
 468         struct vis_info_entry *entry, *entry_array;
 469         struct hna_local_entry *hna_local_entry;
 470         int best_tq = -1;
 471         unsigned long flags;
 472
 473         info->first_seen = jiffies;
 474         info->packet.vis_type = atomic_read(&bat_priv->vis_mode);
 475
 476         spin_lock_irqsave(&orig_hash_lock, flags);
 477         memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);
 478         info->packet.ttl = TTL;
 479         info->packet.seqno++;
 480         info->packet.entries = 0;
 481
 482         if (info->packet.vis_type == VIS_TYPE_CLIENT_UPDATE) {
 483                 best_tq = find_best_vis_server(info);
 484                 if (best_tq < 0) {
 485                         spin_unlock_irqrestore(&orig_hash_lock, flags);
 486                         return -1;
 487                 }
 488         }
 489
 490         entry_array = (struct vis_info_entry *)
 491                 ((char *)info + sizeof(struct vis_info));
 492
 493         while (hash_iterate(orig_hash, &hashit_global)) {
 494                 orig_node = hashit_global.bucket->data;
 495                 if (orig_node->router != NULL
 496                         && compare_orig(orig_node->router->addr,
 497                                         orig_node->orig)
 498                         && (orig_node->router->if_incoming->if_status ==
 499                                                                 IF_ACTIVE)
 500                     && orig_node->router->tq_avg > 0) {
 501
 502                         /* fill one entry into buffer. */
 503                         entry = &entry_array[info->packet.entries];
 504                         memcpy(entry->src,
 505                              orig_node->router->if_incoming->net_dev->dev_addr,
 506                                ETH_ALEN);
 507                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 508                         entry->quality = orig_node->router->tq_avg;
 509                         info->packet.entries++;
 510
 511                         if (vis_packet_full(info)) {
 512                                 spin_unlock_irqrestore(&orig_hash_lock, flags);
 513                                 return 0;
 514                         }
 515                 }
 516         }
 517
 518         spin_unlock_irqrestore(&orig_hash_lock, flags);
 519
 520         spin_lock_irqsave(&hna_local_hash_lock, flags);
 521         while (hash_iterate(hna_local_hash, &hashit_local)) {
 522                 hna_local_entry = hashit_local.bucket->data;
 523                 entry = &entry_array[info->packet.entries];
 524                 memset(entry->src, 0, ETH_ALEN);
 525                 memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 526                 entry->quality = 0; /* 0 means HNA */
 527                 info->packet.entries++;
 528
 529                 if (vis_packet_full(info)) {
 530                         spin_unlock_irqrestore(&hna_local_hash_lock, flags);
 531                         return 0;
 532                 }
 533         }
 534         spin_unlock_irqrestore(&hna_local_hash_lock, flags);
 535         return 0;
 536 }
 537
 538 /* free old vis packets. Must be called with this vis_hash_lock
 539  * held */
 540 static void purge_vis_packets(void)
 541 {
 542         HASHIT(hashit);
 543         struct vis_info *info;
 544
 545         while (hash_iterate(vis_hash, &hashit)) {
 546                 info = hashit.bucket->data;
 547                 if (info == my_vis_info)        /* never purge own data. */
 548                         continue;
 549                 if (time_after(jiffies,
 550                                info->first_seen + (VIS_TIMEOUT*HZ)/1000)) {
 551                         hash_remove_bucket(vis_hash, &hashit);
 552                         send_list_del(info);
 553                         kref_put(&info->refcount, free_info);
 554                 }
 555         }
 556 }
 557
 558 static void broadcast_vis_packet(struct vis_info *info, int packet_length)
 559 {
 560         HASHIT(hashit);
 561         struct orig_node *orig_node;
 562         unsigned long flags;
 563         struct batman_if *batman_if;
 564         uint8_t dstaddr[ETH_ALEN];
 565
 566         spin_lock_irqsave(&orig_hash_lock, flags);
 567
 568         /* send to all routers in range. */
 569         while (hash_iterate(orig_hash, &hashit)) {
 570                 orig_node = hashit.bucket->data;
 571
 572                 /* if it's a vis server and reachable, send it. */
 573                 if ((!orig_node) || (!orig_node->router))
 574                         continue;
 575                 if (!(orig_node->flags & VIS_SERVER))
 576                         continue;
 577                 /* don't send it if we already received the packet from
 578                  * this node. */
 579                 if (recv_list_is_in(&info->recv_list, orig_node->orig))
 580                         continue;
 581
 582                 memcpy(info->packet.target_orig, orig_node->orig, ETH_ALEN);
 583                 batman_if = orig_node->router->if_incoming;
 584                 memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 585                 spin_unlock_irqrestore(&orig_hash_lock, flags);
 586
 587                 send_raw_packet((unsigned char *)&info->packet,
 588                                 packet_length, batman_if, dstaddr);
 589
 590                 spin_lock_irqsave(&orig_hash_lock, flags);
 591
 592         }
 593         spin_unlock_irqrestore(&orig_hash_lock, flags);
 594         memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);
 595 }
 596
 597 static void unicast_vis_packet(struct vis_info *info, int packet_length)
 598 {
 599         struct orig_node *orig_node;
 600         unsigned long flags;
 601         struct batman_if *batman_if;
 602         uint8_t dstaddr[ETH_ALEN];
 603
 604         spin_lock_irqsave(&orig_hash_lock, flags);
 605         orig_node = ((struct orig_node *)
 606                      hash_find(orig_hash, info->packet.target_orig));
 607
 608         if ((!orig_node) || (!orig_node->router))
 609                 goto out;
 610
 611         /* don't lock while sending the packets ... we therefore
 612          * copy the required data before sending */
 613         batman_if = orig_node->router->if_incoming;
 614         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 615         spin_unlock_irqrestore(&orig_hash_lock, flags);
 616
 617         send_raw_packet((unsigned char *)&info->packet,
 618                         packet_length, batman_if, dstaddr);
 619         return;
 620
 621 out:
 622         spin_unlock_irqrestore(&orig_hash_lock, flags);
 623 }
 624
 625 /* only send one vis packet. called from send_vis_packets() */
 626 static void send_vis_packet(struct vis_info *info)
 627 {
 628         int packet_length;
 629
 630         if (info->packet.ttl < 2) {
 631                 printk(KERN_WARNING "batman-adv: Error - can't send vis packet: ttl exceeded\n");
 632                 return;
 633         }
 634
 635         memcpy(info->packet.sender_orig, mainIfAddr, ETH_ALEN);
 636         info->packet.ttl--;
 637
 638         packet_length = sizeof(struct vis_packet) +
 639                 info->packet.entries * sizeof(struct vis_info_entry);
 640
 641         if (is_bcast(info->packet.target_orig))
 642                 broadcast_vis_packet(info, packet_length);
 643         else
 644                 unicast_vis_packet(info, packet_length);
 645         info->packet.ttl++; /* restore TTL */
 646 }
 647
 648 /* called from timer; send (and maybe generate) vis packet. */
 649 static void send_vis_packets(struct work_struct *work)
 650 {
 651         struct vis_info *info, *temp;
 652         unsigned long flags;
 653         /* FIXME: each batman_if will be attached to a softif */
 654         struct bat_priv *bat_priv = netdev_priv(soft_device);
 655
 656         spin_lock_irqsave(&vis_hash_lock, flags);
 657
 658         purge_vis_packets();
 659
 660         if (generate_vis_packet(bat_priv) == 0) {
 661                 /* schedule if generation was successful */
 662                 send_list_add(my_vis_info);
 663         }
 664
 665         list_for_each_entry_safe(info, temp, &send_list, send_list) {
 666
 667                 kref_get(&info->refcount);
 668                 spin_unlock_irqrestore(&vis_hash_lock, flags);
 669
 670                 send_vis_packet(info);
 671
 672                 spin_lock_irqsave(&vis_hash_lock, flags);
 673                 send_list_del(info);
 674                 kref_put(&info->refcount, free_info);
 675         }
 676         spin_unlock_irqrestore(&vis_hash_lock, flags);
 677         start_vis_timer();
 678 }
 679 static DECLARE_DELAYED_WORK(vis_timer_wq, send_vis_packets);
 680
 681 /* init the vis server. this may only be called when if_list is already
 682  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 683 int vis_init(void)
 684 {
 685         unsigned long flags;
 686         if (vis_hash)
 687                 return 1;
 688
 689         spin_lock_irqsave(&vis_hash_lock, flags);
 690
 691         vis_hash = hash_new(256, vis_info_cmp, vis_info_choose);
 692         if (!vis_hash) {
 693                 printk(KERN_ERR "batman-adv:Can't initialize vis_hash\n");
 694                 goto err;
 695         }
 696
 697         my_vis_info = kmalloc(1000, GFP_ATOMIC);
 698         if (!my_vis_info) {
 699                 printk(KERN_ERR "batman-adv:Can't initialize vis packet\n");
 700                 goto err;
 701         }
 702
 703         /* prefill the vis info */
 704         my_vis_info->first_seen = jiffies - atomic_read(&vis_interval);
 705         INIT_LIST_HEAD(&my_vis_info->recv_list);
 706         INIT_LIST_HEAD(&my_vis_info->send_list);
 707         kref_init(&my_vis_info->refcount);
 708         my_vis_info->packet.version = COMPAT_VERSION;
 709         my_vis_info->packet.packet_type = BAT_VIS;
 710         my_vis_info->packet.ttl = TTL;
 711         my_vis_info->packet.seqno = 0;
 712         my_vis_info->packet.entries = 0;
 713
 714         INIT_LIST_HEAD(&send_list);
 715
 716         memcpy(my_vis_info->packet.vis_orig, mainIfAddr, ETH_ALEN);
 717         memcpy(my_vis_info->packet.sender_orig, mainIfAddr, ETH_ALEN);
 718
 719         if (hash_add(vis_hash, my_vis_info) < 0) {
 720                 printk(KERN_ERR
 721                        "batman-adv:Can't add own vis packet into hash\n");
 722                 /* not in hash, need to remove it manually. */
 723                 kref_put(&my_vis_info->refcount, free_info);
 724                 goto err;
 725         }
 726
 727         spin_unlock_irqrestore(&vis_hash_lock, flags);
 728         start_vis_timer();
 729         return 1;
 730
 731 err:
 732         spin_unlock_irqrestore(&vis_hash_lock, flags);
 733         vis_quit();
 734         return 0;
 735 }
 736
 737 /* Decrease the reference count on a hash item info */
 738 static void free_info_ref(void *data)
 739 {
 740         struct vis_info *info = data;
 741
 742         send_list_del(info);
 743         kref_put(&info->refcount, free_info);
 744 }
 745
 746 /* shutdown vis-server */
 747 void vis_quit(void)
 748 {
 749         unsigned long flags;
 750         if (!vis_hash)
 751                 return;
 752
 753         cancel_delayed_work_sync(&vis_timer_wq);
 754
 755         spin_lock_irqsave(&vis_hash_lock, flags);
 756         /* properly remove, kill timers ... */
 757         hash_delete(vis_hash, free_info_ref);
 758         vis_hash = NULL;
 759         my_vis_info = NULL;
 760         spin_unlock_irqrestore(&vis_hash_lock, flags);
 761 }
 762
 763 /* schedule packets for (re)transmission */
 764 static void start_vis_timer(void)
 765 {
 766         queue_delayed_work(bat_event_workqueue, &vis_timer_wq,
 767                            (atomic_read(&vis_interval) * HZ) / 1000);
 768 }