net/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2011 B.A.T.M.A.N. contributors:
   3  *
   4  * Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "translation-table.h"
  25 #include "vis.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "hash.h"
  29 #include "originator.h"
  30
  31 #define MAX_VIS_PACKET_SIZE 1000
  32
  33 /* Returns the smallest signed integer in two's complement with the sizeof x */
  34 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  35
  36 /* Checks if a sequence number x is a predecessor/successor of y.
  37  * they handle overflows/underflows and can correctly check for a
  38  * predecessor/successor unless the variable sequence number has grown by
  39  * more then 2**(bitwidth(x)-1)-1.
  40  * This means that for a uint8_t with the maximum value 255, it would think:
  41  *  - when adding nothing - it is neither a predecessor nor a successor
  42  *  - before adding more than 127 to the starting value - it is a predecessor,
  43  *  - when adding 128 - it is neither a predecessor nor a successor,
  44  *  - after adding more than 127 to the starting value - it is a successor */
  45 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  46                         _dummy > smallest_signed_int(_dummy); })
  47 #define seq_after(x, y) seq_before(y, x)
  48
  49 static void start_vis_timer(struct bat_priv *bat_priv);
  50
  51 /* free the info */
  52 static void free_info(struct kref *ref)
  53 {
  54         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  55         struct bat_priv *bat_priv = info->bat_priv;
  56         struct recvlist_node *entry, *tmp;
  57
  58         list_del_init(&info->send_list);
  59         spin_lock_bh(&bat_priv->vis_list_lock);
  60         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  61                 list_del(&entry->list);
  62                 kfree(entry);
  63         }
  64
  65         spin_unlock_bh(&bat_priv->vis_list_lock);
  66         kfree_skb(info->skb_packet);
  67 }
  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_eth(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_eth(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_eth(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_eth(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_eth(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_eth(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_eth(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 (compare_eth(entry->mac, mac)) {
 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         rcu_read_lock();
 384         old_info = hash_find(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 385                              &search_elem);
 386         rcu_read_unlock();
 387         kfree_skb(search_elem.skb_packet);
 388
 389         if (old_info) {
 390                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 391                 if (!seq_after(ntohl(vis_packet->seqno),
 392                                ntohl(old_packet->seqno))) {
 393                         if (old_packet->seqno == vis_packet->seqno) {
 394                                 recv_list_add(bat_priv, &old_info->recv_list,
 395                                               vis_packet->sender_orig);
 396                                 return old_info;
 397                         } else {
 398                                 /* newer packet is already in hash. */
 399                                 return NULL;
 400                         }
 401                 }
 402                 /* remove old entry */
 403                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 404                             old_info);
 405                 send_list_del(old_info);
 406                 kref_put(&old_info->refcount, free_info);
 407         }
 408
 409         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 410         if (!info)
 411                 return NULL;
 412
 413         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 414                                          vis_info_len + sizeof(struct ethhdr));
 415         if (!info->skb_packet) {
 416                 kfree(info);
 417                 return NULL;
 418         }
 419         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 420         packet = (struct vis_packet *)skb_put(info->skb_packet,
 421                                               sizeof(struct vis_packet) +
 422                                               vis_info_len);
 423
 424         kref_init(&info->refcount);
 425         INIT_LIST_HEAD(&info->send_list);
 426         INIT_LIST_HEAD(&info->recv_list);
 427         info->first_seen = jiffies;
 428         info->bat_priv = bat_priv;
 429         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 430
 431         /* initialize and add new packet. */
 432         *is_new = 1;
 433
 434         /* Make it a broadcast packet, if required */
 435         if (make_broadcast)
 436                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 437
 438         /* repair if entries is longer than packet. */
 439         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 440                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 441
 442         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 443
 444         /* try to add it */
 445         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 446                               info);
 447         if (hash_added < 0) {
 448                 /* did not work (for some reason) */
 449                 kref_put(&old_info->refcount, free_info);
 450                 info = NULL;
 451         }
 452
 453         return info;
 454 }
 455
 456 /* handle the server sync packet, forward if needed. */
 457 void receive_server_sync_packet(struct bat_priv *bat_priv,
 458                                 struct vis_packet *vis_packet,
 459                                 int vis_info_len)
 460 {
 461         struct vis_info *info;
 462         int is_new, make_broadcast;
 463         int vis_server = atomic_read(&bat_priv->vis_mode);
 464
 465         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 466
 467         spin_lock_bh(&bat_priv->vis_hash_lock);
 468         info = add_packet(bat_priv, vis_packet, vis_info_len,
 469                           &is_new, make_broadcast);
 470         if (!info)
 471                 goto end;
 472
 473         /* only if we are server ourselves and packet is newer than the one in
 474          * hash.*/
 475         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 476                 send_list_add(bat_priv, info);
 477 end:
 478         spin_unlock_bh(&bat_priv->vis_hash_lock);
 479 }
 480
 481 /* handle an incoming client update packet and schedule forward if needed. */
 482 void receive_client_update_packet(struct bat_priv *bat_priv,
 483                                   struct vis_packet *vis_packet,
 484                                   int vis_info_len)
 485 {
 486         struct vis_info *info;
 487         struct vis_packet *packet;
 488         int is_new;
 489         int vis_server = atomic_read(&bat_priv->vis_mode);
 490         int are_target = 0;
 491
 492         /* clients shall not broadcast. */
 493         if (is_broadcast_ether_addr(vis_packet->target_orig))
 494                 return;
 495
 496         /* Are we the target for this VIS packet? */
 497         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 498             is_my_mac(vis_packet->target_orig))
 499                 are_target = 1;
 500
 501         spin_lock_bh(&bat_priv->vis_hash_lock);
 502         info = add_packet(bat_priv, vis_packet, vis_info_len,
 503                           &is_new, are_target);
 504
 505         if (!info)
 506                 goto end;
 507         /* note that outdated packets will be dropped at this point. */
 508
 509         packet = (struct vis_packet *)info->skb_packet->data;
 510
 511         /* send only if we're the target server or ... */
 512         if (are_target && is_new) {
 513                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 514                 send_list_add(bat_priv, info);
 515
 516                 /* ... we're not the recipient (and thus need to forward). */
 517         } else if (!is_my_mac(packet->target_orig)) {
 518                 send_list_add(bat_priv, info);
 519         }
 520
 521 end:
 522         spin_unlock_bh(&bat_priv->vis_hash_lock);
 523 }
 524
 525 /* Walk the originators and find the VIS server with the best tq. Set the packet
 526  * address to its address and return the best_tq.
 527  *
 528  * Must be called with the originator hash locked */
 529 static int find_best_vis_server(struct bat_priv *bat_priv,
 530                                 struct vis_info *info)
 531 {
 532         struct hashtable_t *hash = bat_priv->orig_hash;
 533         struct hlist_node *walk;
 534         struct hlist_head *head;
 535         struct element_t *bucket;
 536         struct orig_node *orig_node;
 537         struct vis_packet *packet;
 538         int best_tq = -1, i;
 539
 540         packet = (struct vis_packet *)info->skb_packet->data;
 541
 542         for (i = 0; i < hash->size; i++) {
 543                 head = &hash->table[i];
 544
 545                 rcu_read_lock();
 546                 hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
 547                         orig_node = bucket->data;
 548                         if ((orig_node) && (orig_node->router) &&
 549                         (orig_node->flags & VIS_SERVER) &&
 550                         (orig_node->router->tq_avg > best_tq)) {
 551                                 best_tq = orig_node->router->tq_avg;
 552                                 memcpy(packet->target_orig, orig_node->orig,
 553                                        ETH_ALEN);
 554                         }
 555                 }
 556                 rcu_read_unlock();
 557         }
 558
 559         return best_tq;
 560 }
 561
 562 /* Return true if the vis packet is full. */
 563 static bool vis_packet_full(struct vis_info *info)
 564 {
 565         struct vis_packet *packet;
 566         packet = (struct vis_packet *)info->skb_packet->data;
 567
 568         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 569                 < packet->entries + 1)
 570                 return true;
 571         return false;
 572 }
 573
 574 /* generates a packet of own vis data,
 575  * returns 0 on success, -1 if no packet could be generated */
 576 static int generate_vis_packet(struct bat_priv *bat_priv)
 577 {
 578         struct hashtable_t *hash = bat_priv->orig_hash;
 579         struct hlist_node *walk;
 580         struct hlist_head *head;
 581         struct element_t *bucket;
 582         struct orig_node *orig_node;
 583         struct neigh_node *neigh_node;
 584         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 585         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 586         struct vis_info_entry *entry;
 587         struct hna_local_entry *hna_local_entry;
 588         int best_tq = -1, i;
 589
 590         info->first_seen = jiffies;
 591         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 592
 593         spin_lock_bh(&bat_priv->orig_hash_lock);
 594         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 595         packet->ttl = TTL;
 596         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 597         packet->entries = 0;
 598         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 599
 600         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 601                 best_tq = find_best_vis_server(bat_priv, info);
 602
 603                 if (best_tq < 0) {
 604                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 605                         return -1;
 606                 }
 607         }
 608
 609         for (i = 0; i < hash->size; i++) {
 610                 head = &hash->table[i];
 611
 612                 rcu_read_lock();
 613                 hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
 614                         orig_node = bucket->data;
 615                         neigh_node = orig_node->router;
 616
 617                         if (!neigh_node)
 618                                 continue;
 619
 620                         if (!compare_eth(neigh_node->addr, orig_node->orig))
 621                                 continue;
 622
 623                         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
 624                                 continue;
 625
 626                         if (neigh_node->tq_avg < 1)
 627                                 continue;
 628
 629                         /* fill one entry into buffer. */
 630                         entry = (struct vis_info_entry *)
 631                                       skb_put(info->skb_packet, sizeof(*entry));
 632                         memcpy(entry->src,
 633                                neigh_node->if_incoming->net_dev->dev_addr,
 634                                ETH_ALEN);
 635                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 636                         entry->quality = neigh_node->tq_avg;
 637                         packet->entries++;
 638
 639                         if (vis_packet_full(info)) {
 640                                 rcu_read_unlock();
 641                                 spin_unlock_bh(&bat_priv->orig_hash_lock);
 642                                 return 0;
 643                         }
 644                 }
 645                 rcu_read_unlock();
 646         }
 647
 648         spin_unlock_bh(&bat_priv->orig_hash_lock);
 649
 650         hash = bat_priv->hna_local_hash;
 651
 652         spin_lock_bh(&bat_priv->hna_lhash_lock);
 653         for (i = 0; i < hash->size; i++) {
 654                 head = &hash->table[i];
 655
 656                 hlist_for_each_entry(bucket, walk, head, hlist) {
 657                         hna_local_entry = bucket->data;
 658                         entry = (struct vis_info_entry *)
 659                                         skb_put(info->skb_packet,
 660                                                 sizeof(*entry));
 661                         memset(entry->src, 0, ETH_ALEN);
 662                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 663                         entry->quality = 0; /* 0 means HNA */
 664                         packet->entries++;
 665
 666                         if (vis_packet_full(info)) {
 667                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
 668                                 return 0;
 669                         }
 670                 }
 671         }
 672
 673         spin_unlock_bh(&bat_priv->hna_lhash_lock);
 674         return 0;
 675 }
 676
 677 /* free old vis packets. Must be called with this vis_hash_lock
 678  * held */
 679 static void purge_vis_packets(struct bat_priv *bat_priv)
 680 {
 681         int i;
 682         struct hashtable_t *hash = bat_priv->vis_hash;
 683         struct hlist_node *walk, *safe;
 684         struct hlist_head *head;
 685         struct element_t *bucket;
 686         struct vis_info *info;
 687
 688         for (i = 0; i < hash->size; i++) {
 689                 head = &hash->table[i];
 690
 691                 hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
 692                         info = bucket->data;
 693
 694                         /* never purge own data. */
 695                         if (info == bat_priv->my_vis_info)
 696                                 continue;
 697
 698                         if (time_after(jiffies,
 699                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 700                                 hlist_del(walk);
 701                                 kfree(bucket);
 702                                 send_list_del(info);
 703                                 kref_put(&info->refcount, free_info);
 704                         }
 705                 }
 706         }
 707 }
 708
 709 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 710                                  struct vis_info *info)
 711 {
 712         struct hashtable_t *hash = bat_priv->orig_hash;
 713         struct hlist_node *walk;
 714         struct hlist_head *head;
 715         struct element_t *bucket;
 716         struct orig_node *orig_node;
 717         struct vis_packet *packet;
 718         struct sk_buff *skb;
 719         struct batman_if *batman_if;
 720         uint8_t dstaddr[ETH_ALEN];
 721         int i;
 722
 723
 724         spin_lock_bh(&bat_priv->orig_hash_lock);
 725         packet = (struct vis_packet *)info->skb_packet->data;
 726
 727         /* send to all routers in range. */
 728         for (i = 0; i < hash->size; i++) {
 729                 head = &hash->table[i];
 730
 731                 rcu_read_lock();
 732                 hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
 733                         orig_node = bucket->data;
 734
 735                         /* if it's a vis server and reachable, send it. */
 736                         if ((!orig_node) || (!orig_node->router))
 737                                 continue;
 738                         if (!(orig_node->flags & VIS_SERVER))
 739                                 continue;
 740                         /* don't send it if we already received the packet from
 741                         * this node. */
 742                         if (recv_list_is_in(bat_priv, &info->recv_list,
 743                                             orig_node->orig))
 744                                 continue;
 745
 746                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 747                         batman_if = orig_node->router->if_incoming;
 748                         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 749                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 750
 751                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 752                         if (skb)
 753                                 send_skb_packet(skb, batman_if, dstaddr);
 754
 755                         spin_lock_bh(&bat_priv->orig_hash_lock);
 756                 }
 757                 rcu_read_unlock();
 758         }
 759
 760         spin_unlock_bh(&bat_priv->orig_hash_lock);
 761 }
 762
 763 static void unicast_vis_packet(struct bat_priv *bat_priv,
 764                                struct vis_info *info)
 765 {
 766         struct orig_node *orig_node;
 767         struct neigh_node *neigh_node = NULL;
 768         struct sk_buff *skb;
 769         struct vis_packet *packet;
 770         struct batman_if *batman_if;
 771         uint8_t dstaddr[ETH_ALEN];
 772
 773         packet = (struct vis_packet *)info->skb_packet->data;
 774
 775         spin_lock_bh(&bat_priv->orig_hash_lock);
 776         rcu_read_lock();
 777         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 778                                                    compare_orig, choose_orig,
 779                                                    packet->target_orig));
 780
 781         if (!orig_node)
 782                 goto unlock;
 783
 784         kref_get(&orig_node->refcount);
 785         neigh_node = orig_node->router;
 786
 787         if (!neigh_node)
 788                 goto unlock;
 789
 790         if (!atomic_inc_not_zero(&neigh_node->refcount)) {
 791                 neigh_node = NULL;
 792                 goto unlock;
 793         }
 794
 795         rcu_read_unlock();
 796
 797         /* don't lock while sending the packets ... we therefore
 798          * copy the required data before sending */
 799         batman_if = orig_node->router->if_incoming;
 800         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 801         spin_unlock_bh(&bat_priv->orig_hash_lock);
 802
 803         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 804         if (skb)
 805                 send_skb_packet(skb, batman_if, dstaddr);
 806
 807         goto out;
 808
 809 unlock:
 810         rcu_read_unlock();
 811         spin_unlock_bh(&bat_priv->orig_hash_lock);
 812 out:
 813         if (neigh_node)
 814                 neigh_node_free_ref(neigh_node);
 815         if (orig_node)
 816                 kref_put(&orig_node->refcount, orig_node_free_ref);
 817         return;
 818 }
 819
 820 /* only send one vis packet. called from send_vis_packets() */
 821 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 822 {
 823         struct vis_packet *packet;
 824
 825         packet = (struct vis_packet *)info->skb_packet->data;
 826         if (packet->ttl < 2) {
 827                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 828                 return;
 829         }
 830
 831         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 832                ETH_ALEN);
 833         packet->ttl--;
 834
 835         if (is_broadcast_ether_addr(packet->target_orig))
 836                 broadcast_vis_packet(bat_priv, info);
 837         else
 838                 unicast_vis_packet(bat_priv, info);
 839         packet->ttl++; /* restore TTL */
 840 }
 841
 842 /* called from timer; send (and maybe generate) vis packet. */
 843 static void send_vis_packets(struct work_struct *work)
 844 {
 845         struct delayed_work *delayed_work =
 846                 container_of(work, struct delayed_work, work);
 847         struct bat_priv *bat_priv =
 848                 container_of(delayed_work, struct bat_priv, vis_work);
 849         struct vis_info *info, *temp;
 850
 851         spin_lock_bh(&bat_priv->vis_hash_lock);
 852         purge_vis_packets(bat_priv);
 853
 854         if (generate_vis_packet(bat_priv) == 0) {
 855                 /* schedule if generation was successful */
 856                 send_list_add(bat_priv, bat_priv->my_vis_info);
 857         }
 858
 859         list_for_each_entry_safe(info, temp, &bat_priv->vis_send_list,
 860                                  send_list) {
 861
 862                 kref_get(&info->refcount);
 863                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 864
 865                 if (bat_priv->primary_if)
 866                         send_vis_packet(bat_priv, info);
 867
 868                 spin_lock_bh(&bat_priv->vis_hash_lock);
 869                 send_list_del(info);
 870                 kref_put(&info->refcount, free_info);
 871         }
 872         spin_unlock_bh(&bat_priv->vis_hash_lock);
 873         start_vis_timer(bat_priv);
 874 }
 875
 876 /* init the vis server. this may only be called when if_list is already
 877  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 878 int vis_init(struct bat_priv *bat_priv)
 879 {
 880         struct vis_packet *packet;
 881         int hash_added;
 882
 883         if (bat_priv->vis_hash)
 884                 return 1;
 885
 886         spin_lock_bh(&bat_priv->vis_hash_lock);
 887
 888         bat_priv->vis_hash = hash_new(256);
 889         if (!bat_priv->vis_hash) {
 890                 pr_err("Can't initialize vis_hash\n");
 891                 goto err;
 892         }
 893
 894         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 895         if (!bat_priv->my_vis_info) {
 896                 pr_err("Can't initialize vis packet\n");
 897                 goto err;
 898         }
 899
 900         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 901                                                 sizeof(struct vis_packet) +
 902                                                 MAX_VIS_PACKET_SIZE +
 903                                                 sizeof(struct ethhdr));
 904         if (!bat_priv->my_vis_info->skb_packet)
 905                 goto free_info;
 906
 907         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 908         packet = (struct vis_packet *)skb_put(
 909                                         bat_priv->my_vis_info->skb_packet,
 910                                         sizeof(struct vis_packet));
 911
 912         /* prefill the vis info */
 913         bat_priv->my_vis_info->first_seen = jiffies -
 914                                                 msecs_to_jiffies(VIS_INTERVAL);
 915         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 916         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 917         kref_init(&bat_priv->my_vis_info->refcount);
 918         bat_priv->my_vis_info->bat_priv = bat_priv;
 919         packet->version = COMPAT_VERSION;
 920         packet->packet_type = BAT_VIS;
 921         packet->ttl = TTL;
 922         packet->seqno = 0;
 923         packet->entries = 0;
 924
 925         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 926
 927         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 928                               bat_priv->my_vis_info);
 929         if (hash_added < 0) {
 930                 pr_err("Can't add own vis packet into hash\n");
 931                 /* not in hash, need to remove it manually. */
 932                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 933                 goto err;
 934         }
 935
 936         spin_unlock_bh(&bat_priv->vis_hash_lock);
 937         start_vis_timer(bat_priv);
 938         return 1;
 939
 940 free_info:
 941         kfree(bat_priv->my_vis_info);
 942         bat_priv->my_vis_info = NULL;
 943 err:
 944         spin_unlock_bh(&bat_priv->vis_hash_lock);
 945         vis_quit(bat_priv);
 946         return 0;
 947 }
 948
 949 /* Decrease the reference count on a hash item info */
 950 static void free_info_ref(void *data, void *arg)
 951 {
 952         struct vis_info *info = data;
 953
 954         send_list_del(info);
 955         kref_put(&info->refcount, free_info);
 956 }
 957
 958 /* shutdown vis-server */
 959 void vis_quit(struct bat_priv *bat_priv)
 960 {
 961         if (!bat_priv->vis_hash)
 962                 return;
 963
 964         cancel_delayed_work_sync(&bat_priv->vis_work);
 965
 966         spin_lock_bh(&bat_priv->vis_hash_lock);
 967         /* properly remove, kill timers ... */
 968         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 969         bat_priv->vis_hash = NULL;
 970         bat_priv->my_vis_info = NULL;
 971         spin_unlock_bh(&bat_priv->vis_hash_lock);
 972 }
 973
 974 /* schedule packets for (re)transmission */
 975 static void start_vis_timer(struct bat_priv *bat_priv)
 976 {
 977         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 978         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 979                            msecs_to_jiffies(VIS_INTERVAL));
 980 }