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         kfree(info);
  68 }
  69
  70 /* Compare two vis packets, used by the hashing algorithm */
  71 static int vis_info_cmp(void *data1, void *data2)
  72 {
  73         struct vis_info *d1, *d2;
  74         struct vis_packet *p1, *p2;
  75         d1 = data1;
  76         d2 = data2;
  77         p1 = (struct vis_packet *)d1->skb_packet->data;
  78         p2 = (struct vis_packet *)d2->skb_packet->data;
  79         return compare_orig(p1->vis_orig, p2->vis_orig);
  80 }
  81
  82 /* hash function to choose an entry in a hash table of given size */
  83 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  84 static int vis_info_choose(void *data, int size)
  85 {
  86         struct vis_info *vis_info = data;
  87         struct vis_packet *packet;
  88         unsigned char *key;
  89         uint32_t hash = 0;
  90         size_t i;
  91
  92         packet = (struct vis_packet *)vis_info->skb_packet->data;
  93         key = packet->vis_orig;
  94         for (i = 0; i < ETH_ALEN; i++) {
  95                 hash += key[i];
  96                 hash += (hash << 10);
  97                 hash ^= (hash >> 6);
  98         }
  99
 100         hash += (hash << 3);
 101         hash ^= (hash >> 11);
 102         hash += (hash << 15);
 103
 104         return hash % size;
 105 }
 106
 107 /* insert interface to the list of interfaces of one originator, if it
 108  * does not already exist in the list */
 109 static void vis_data_insert_interface(const uint8_t *interface,
 110                                       struct hlist_head *if_list,
 111                                       bool primary)
 112 {
 113         struct if_list_entry *entry;
 114         struct hlist_node *pos;
 115
 116         hlist_for_each_entry(entry, pos, if_list, list) {
 117                 if (compare_orig(entry->addr, (void *)interface))
 118                         return;
 119         }
 120
 121         /* its a new address, add it to the list */
 122         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 123         if (!entry)
 124                 return;
 125         memcpy(entry->addr, interface, ETH_ALEN);
 126         entry->primary = primary;
 127         hlist_add_head(&entry->list, if_list);
 128 }
 129
 130 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
 131 {
 132         struct if_list_entry *entry;
 133         struct hlist_node *pos;
 134         size_t len = 0;
 135
 136         hlist_for_each_entry(entry, pos, if_list, list) {
 137                 if (entry->primary)
 138                         len += sprintf(buff + len, "PRIMARY, ");
 139                 else
 140                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 141         }
 142
 143         return len;
 144 }
 145
 146 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 147 {
 148         struct if_list_entry *entry;
 149         struct hlist_node *pos;
 150         size_t count = 0;
 151
 152         hlist_for_each_entry(entry, pos, if_list, list) {
 153                 if (entry->primary)
 154                         count += 9;
 155                 else
 156                         count += 23;
 157         }
 158
 159         return count;
 160 }
 161
 162 /* read an entry  */
 163 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 164                                    uint8_t *src, bool primary)
 165 {
 166         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 167         if (primary && entry->quality == 0)
 168                 return sprintf(buff, "HNA %pM, ", entry->dest);
 169         else if (compare_orig(entry->src, src))
 170                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 171                                entry->quality);
 172
 173         return 0;
 174 }
 175
 176 int vis_seq_print_text(struct seq_file *seq, void *offset)
 177 {
 178         struct hlist_node *walk;
 179         struct hlist_head *head;
 180         struct element_t *bucket;
 181         struct vis_info *info;
 182         struct vis_packet *packet;
 183         struct vis_info_entry *entries;
 184         struct net_device *net_dev = (struct net_device *)seq->private;
 185         struct bat_priv *bat_priv = netdev_priv(net_dev);
 186         struct hashtable_t *hash = bat_priv->vis_hash;
 187         HLIST_HEAD(vis_if_list);
 188         struct if_list_entry *entry;
 189         struct hlist_node *pos, *n;
 190         int i, j;
 191         int vis_server = atomic_read(&bat_priv->vis_mode);
 192         size_t buff_pos, buf_size;
 193         char *buff;
 194         int compare;
 195
 196         if ((!bat_priv->primary_if) ||
 197             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 198                 return 0;
 199
 200         buf_size = 1;
 201         /* Estimate length */
 202         spin_lock_bh(&bat_priv->vis_hash_lock);
 203         for (i = 0; i < hash->size; i++) {
 204                 head = &hash->table[i];
 205
 206                 hlist_for_each_entry(bucket, walk, head, hlist) {
 207                         info = bucket->data;
 208                         packet = (struct vis_packet *)info->skb_packet->data;
 209                         entries = (struct vis_info_entry *)
 210                                 ((char *)packet + sizeof(struct vis_packet));
 211
 212                         for (j = 0; j < packet->entries; j++) {
 213                                 if (entries[j].quality == 0)
 214                                         continue;
 215                                 compare =
 216                                  compare_orig(entries[j].src, packet->vis_orig);
 217                                 vis_data_insert_interface(entries[j].src,
 218                                                           &vis_if_list,
 219                                                           compare);
 220                         }
 221
 222                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 223                                 buf_size += 18 + 26 * packet->entries;
 224
 225                                 /* add primary/secondary records */
 226                                 if (compare_orig(entry->addr, packet->vis_orig))
 227                                         buf_size +=
 228                                           vis_data_count_prim_sec(&vis_if_list);
 229
 230                                 buf_size += 1;
 231                         }
 232
 233                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 234                                                   list) {
 235                                 hlist_del(&entry->list);
 236                                 kfree(entry);
 237                         }
 238                 }
 239         }
 240
 241         buff = kmalloc(buf_size, GFP_ATOMIC);
 242         if (!buff) {
 243                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 244                 return -ENOMEM;
 245         }
 246         buff[0] = '\0';
 247         buff_pos = 0;
 248
 249         for (i = 0; i < hash->size; i++) {
 250                 head = &hash->table[i];
 251
 252                 hlist_for_each_entry(bucket, walk, head, hlist) {
 253                         info = bucket->data;
 254                         packet = (struct vis_packet *)info->skb_packet->data;
 255                         entries = (struct vis_info_entry *)
 256                                 ((char *)packet + sizeof(struct vis_packet));
 257
 258                         for (j = 0; j < packet->entries; j++) {
 259                                 if (entries[j].quality == 0)
 260                                         continue;
 261                                 compare =
 262                                  compare_orig(entries[j].src, packet->vis_orig);
 263                                 vis_data_insert_interface(entries[j].src,
 264                                                           &vis_if_list,
 265                                                           compare);
 266                         }
 267
 268                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 269                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 270                                                 entry->addr);
 271
 272                                 for (j = 0; j < packet->entries; j++)
 273                                         buff_pos += vis_data_read_entry(
 274                                                         buff + buff_pos,
 275                                                         &entries[j],
 276                                                         entry->addr,
 277                                                         entry->primary);
 278
 279                                 /* add primary/secondary records */
 280                                 if (compare_orig(entry->addr, packet->vis_orig))
 281                                         buff_pos +=
 282                                          vis_data_read_prim_sec(buff + buff_pos,
 283                                                                 &vis_if_list);
 284
 285                                 buff_pos += sprintf(buff + buff_pos, "\n");
 286                         }
 287
 288                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 289                                                   list) {
 290                                 hlist_del(&entry->list);
 291                                 kfree(entry);
 292                         }
 293                 }
 294         }
 295
 296         spin_unlock_bh(&bat_priv->vis_hash_lock);
 297
 298         seq_printf(seq, "%s", buff);
 299         kfree(buff);
 300
 301         return 0;
 302 }
 303
 304 /* add the info packet to the send list, if it was not
 305  * already linked in. */
 306 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 307 {
 308         if (list_empty(&info->send_list)) {
 309                 kref_get(&info->refcount);
 310                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 311         }
 312 }
 313
 314 /* delete the info packet from the send list, if it was
 315  * linked in. */
 316 static void send_list_del(struct vis_info *info)
 317 {
 318         if (!list_empty(&info->send_list)) {
 319                 list_del_init(&info->send_list);
 320                 kref_put(&info->refcount, free_info);
 321         }
 322 }
 323
 324 /* tries to add one entry to the receive list. */
 325 static void recv_list_add(struct bat_priv *bat_priv,
 326                           struct list_head *recv_list, char *mac)
 327 {
 328         struct recvlist_node *entry;
 329
 330         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 331         if (!entry)
 332                 return;
 333
 334         memcpy(entry->mac, mac, ETH_ALEN);
 335         spin_lock_bh(&bat_priv->vis_list_lock);
 336         list_add_tail(&entry->list, recv_list);
 337         spin_unlock_bh(&bat_priv->vis_list_lock);
 338 }
 339
 340 /* returns 1 if this mac is in the recv_list */
 341 static int recv_list_is_in(struct bat_priv *bat_priv,
 342                            struct list_head *recv_list, char *mac)
 343 {
 344         struct recvlist_node *entry;
 345
 346         spin_lock_bh(&bat_priv->vis_list_lock);
 347         list_for_each_entry(entry, recv_list, list) {
 348                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
 349                         spin_unlock_bh(&bat_priv->vis_list_lock);
 350                         return 1;
 351                 }
 352         }
 353         spin_unlock_bh(&bat_priv->vis_list_lock);
 354         return 0;
 355 }
 356
 357 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 358  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 359  * is newer than old entries in the hash. */
 360 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 361                                    struct vis_packet *vis_packet,
 362                                    int vis_info_len, int *is_new,
 363                                    int make_broadcast)
 364 {
 365         struct vis_info *info, *old_info;
 366         struct vis_packet *search_packet, *old_packet;
 367         struct vis_info search_elem;
 368         struct vis_packet *packet;
 369         int hash_added;
 370
 371         *is_new = 0;
 372         /* sanity check */
 373         if (!bat_priv->vis_hash)
 374                 return NULL;
 375
 376         /* see if the packet is already in vis_hash */
 377         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
 378         if (!search_elem.skb_packet)
 379                 return NULL;
 380         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 381                                                      sizeof(struct vis_packet));
 382
 383         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 384         old_info = hash_find(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 385                              &search_elem);
 386         kfree_skb(search_elem.skb_packet);
 387
 388         if (old_info) {
 389                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 390                 if (!seq_after(ntohl(vis_packet->seqno),
 391                                ntohl(old_packet->seqno))) {
 392                         if (old_packet->seqno == vis_packet->seqno) {
 393                                 recv_list_add(bat_priv, &old_info->recv_list,
 394                                               vis_packet->sender_orig);
 395                                 return old_info;
 396                         } else {
 397                                 /* newer packet is already in hash. */
 398                                 return NULL;
 399                         }
 400                 }
 401                 /* remove old entry */
 402                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 403                             old_info);
 404                 send_list_del(old_info);
 405                 kref_put(&old_info->refcount, free_info);
 406         }
 407
 408         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 409         if (!info)
 410                 return NULL;
 411
 412         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 413                                          vis_info_len + sizeof(struct ethhdr));
 414         if (!info->skb_packet) {
 415                 kfree(info);
 416                 return NULL;
 417         }
 418         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 419         packet = (struct vis_packet *)skb_put(info->skb_packet,
 420                                               sizeof(struct vis_packet) +
 421                                               vis_info_len);
 422
 423         kref_init(&info->refcount);
 424         INIT_LIST_HEAD(&info->send_list);
 425         INIT_LIST_HEAD(&info->recv_list);
 426         info->first_seen = jiffies;
 427         info->bat_priv = bat_priv;
 428         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 429
 430         /* initialize and add new packet. */
 431         *is_new = 1;
 432
 433         /* Make it a broadcast packet, if required */
 434         if (make_broadcast)
 435                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 436
 437         /* repair if entries is longer than packet. */
 438         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 439                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 440
 441         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 442
 443         /* try to add it */
 444         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 445                               info);
 446         if (hash_added < 0) {
 447                 /* did not work (for some reason) */
 448                 kref_put(&info->refcount, free_info);
 449                 info = NULL;
 450         }
 451
 452         return info;
 453 }
 454
 455 /* handle the server sync packet, forward if needed. */
 456 void receive_server_sync_packet(struct bat_priv *bat_priv,
 457                                 struct vis_packet *vis_packet,
 458                                 int vis_info_len)
 459 {
 460         struct vis_info *info;
 461         int is_new, make_broadcast;
 462         int vis_server = atomic_read(&bat_priv->vis_mode);
 463
 464         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 465
 466         spin_lock_bh(&bat_priv->vis_hash_lock);
 467         info = add_packet(bat_priv, vis_packet, vis_info_len,
 468                           &is_new, make_broadcast);
 469         if (!info)
 470                 goto end;
 471
 472         /* only if we are server ourselves and packet is newer than the one in
 473          * hash.*/
 474         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 475                 send_list_add(bat_priv, info);
 476 end:
 477         spin_unlock_bh(&bat_priv->vis_hash_lock);
 478 }
 479
 480 /* handle an incoming client update packet and schedule forward if needed. */
 481 void receive_client_update_packet(struct bat_priv *bat_priv,
 482                                   struct vis_packet *vis_packet,
 483                                   int vis_info_len)
 484 {
 485         struct vis_info *info;
 486         struct vis_packet *packet;
 487         int is_new;
 488         int vis_server = atomic_read(&bat_priv->vis_mode);
 489         int are_target = 0;
 490
 491         /* clients shall not broadcast. */
 492         if (is_broadcast_ether_addr(vis_packet->target_orig))
 493                 return;
 494
 495         /* Are we the target for this VIS packet? */
 496         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 497             is_my_mac(vis_packet->target_orig))
 498                 are_target = 1;
 499
 500         spin_lock_bh(&bat_priv->vis_hash_lock);
 501         info = add_packet(bat_priv, vis_packet, vis_info_len,
 502                           &is_new, are_target);
 503
 504         if (!info)
 505                 goto end;
 506         /* note that outdated packets will be dropped at this point. */
 507
 508         packet = (struct vis_packet *)info->skb_packet->data;
 509
 510         /* send only if we're the target server or ... */
 511         if (are_target && is_new) {
 512                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 513                 send_list_add(bat_priv, info);
 514
 515                 /* ... we're not the recipient (and thus need to forward). */
 516         } else if (!is_my_mac(packet->target_orig)) {
 517                 send_list_add(bat_priv, info);
 518         }
 519
 520 end:
 521         spin_unlock_bh(&bat_priv->vis_hash_lock);
 522 }
 523
 524 /* Walk the originators and find the VIS server with the best tq. Set the packet
 525  * address to its address and return the best_tq.
 526  *
 527  * Must be called with the originator hash locked */
 528 static int find_best_vis_server(struct bat_priv *bat_priv,
 529                                 struct vis_info *info)
 530 {
 531         struct hashtable_t *hash = bat_priv->orig_hash;
 532         struct hlist_node *walk;
 533         struct hlist_head *head;
 534         struct element_t *bucket;
 535         struct orig_node *orig_node;
 536         struct vis_packet *packet;
 537         int best_tq = -1, i;
 538
 539         packet = (struct vis_packet *)info->skb_packet->data;
 540
 541         for (i = 0; i < hash->size; i++) {
 542                 head = &hash->table[i];
 543
 544                 hlist_for_each_entry(bucket, walk, head, hlist) {
 545                         orig_node = bucket->data;
 546                         if ((orig_node) && (orig_node->router) &&
 547                         (orig_node->flags & VIS_SERVER) &&
 548                         (orig_node->router->tq_avg > best_tq)) {
 549                                 best_tq = orig_node->router->tq_avg;
 550                                 memcpy(packet->target_orig, orig_node->orig,
 551                                        ETH_ALEN);
 552                         }
 553                 }
 554         }
 555
 556         return best_tq;
 557 }
 558
 559 /* Return true if the vis packet is full. */
 560 static bool vis_packet_full(struct vis_info *info)
 561 {
 562         struct vis_packet *packet;
 563         packet = (struct vis_packet *)info->skb_packet->data;
 564
 565         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 566                 < packet->entries + 1)
 567                 return true;
 568         return false;
 569 }
 570
 571 /* generates a packet of own vis data,
 572  * returns 0 on success, -1 if no packet could be generated */
 573 static int generate_vis_packet(struct bat_priv *bat_priv)
 574 {
 575         struct hashtable_t *hash = bat_priv->orig_hash;
 576         struct hlist_node *walk;
 577         struct hlist_head *head;
 578         struct element_t *bucket;
 579         struct orig_node *orig_node;
 580         struct neigh_node *neigh_node;
 581         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 582         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 583         struct vis_info_entry *entry;
 584         struct hna_local_entry *hna_local_entry;
 585         int best_tq = -1, i;
 586
 587         info->first_seen = jiffies;
 588         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 589
 590         spin_lock_bh(&bat_priv->orig_hash_lock);
 591         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 592         packet->ttl = TTL;
 593         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 594         packet->entries = 0;
 595         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 596
 597         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 598                 best_tq = find_best_vis_server(bat_priv, info);
 599
 600                 if (best_tq < 0) {
 601                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 602                         return -1;
 603                 }
 604         }
 605
 606         for (i = 0; i < hash->size; i++) {
 607                 head = &hash->table[i];
 608
 609                 hlist_for_each_entry(bucket, walk, head, hlist) {
 610                         orig_node = bucket->data;
 611                         neigh_node = orig_node->router;
 612
 613                         if (!neigh_node)
 614                                 continue;
 615
 616                         if (!compare_orig(neigh_node->addr, orig_node->orig))
 617                                 continue;
 618
 619                         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
 620                                 continue;
 621
 622                         if (neigh_node->tq_avg < 1)
 623                                 continue;
 624
 625                         /* fill one entry into buffer. */
 626                         entry = (struct vis_info_entry *)
 627                                       skb_put(info->skb_packet, sizeof(*entry));
 628                         memcpy(entry->src,
 629                                neigh_node->if_incoming->net_dev->dev_addr,
 630                                ETH_ALEN);
 631                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 632                         entry->quality = neigh_node->tq_avg;
 633                         packet->entries++;
 634
 635                         if (vis_packet_full(info)) {
 636                                 spin_unlock_bh(&bat_priv->orig_hash_lock);
 637                                 return 0;
 638                         }
 639                 }
 640         }
 641
 642         spin_unlock_bh(&bat_priv->orig_hash_lock);
 643
 644         hash = bat_priv->hna_local_hash;
 645
 646         spin_lock_bh(&bat_priv->hna_lhash_lock);
 647         for (i = 0; i < hash->size; i++) {
 648                 head = &hash->table[i];
 649
 650                 hlist_for_each_entry(bucket, walk, head, hlist) {
 651                         hna_local_entry = bucket->data;
 652                         entry = (struct vis_info_entry *)
 653                                         skb_put(info->skb_packet,
 654                                                 sizeof(*entry));
 655                         memset(entry->src, 0, ETH_ALEN);
 656                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 657                         entry->quality = 0; /* 0 means HNA */
 658                         packet->entries++;
 659
 660                         if (vis_packet_full(info)) {
 661                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
 662                                 return 0;
 663                         }
 664                 }
 665         }
 666
 667         spin_unlock_bh(&bat_priv->hna_lhash_lock);
 668         return 0;
 669 }
 670
 671 /* free old vis packets. Must be called with this vis_hash_lock
 672  * held */
 673 static void purge_vis_packets(struct bat_priv *bat_priv)
 674 {
 675         int i;
 676         struct hashtable_t *hash = bat_priv->vis_hash;
 677         struct hlist_node *walk, *safe;
 678         struct hlist_head *head;
 679         struct element_t *bucket;
 680         struct vis_info *info;
 681
 682         for (i = 0; i < hash->size; i++) {
 683                 head = &hash->table[i];
 684
 685                 hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
 686                         info = bucket->data;
 687
 688                         /* never purge own data. */
 689                         if (info == bat_priv->my_vis_info)
 690                                 continue;
 691
 692                         if (time_after(jiffies,
 693                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 694                                 hlist_del(walk);
 695                                 kfree(bucket);
 696                                 send_list_del(info);
 697                                 kref_put(&info->refcount, free_info);
 698                         }
 699                 }
 700         }
 701 }
 702
 703 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 704                                  struct vis_info *info)
 705 {
 706         struct hashtable_t *hash = bat_priv->orig_hash;
 707         struct hlist_node *walk;
 708         struct hlist_head *head;
 709         struct element_t *bucket;
 710         struct orig_node *orig_node;
 711         struct vis_packet *packet;
 712         struct sk_buff *skb;
 713         struct batman_if *batman_if;
 714         uint8_t dstaddr[ETH_ALEN];
 715         int i;
 716
 717
 718         spin_lock_bh(&bat_priv->orig_hash_lock);
 719         packet = (struct vis_packet *)info->skb_packet->data;
 720
 721         /* send to all routers in range. */
 722         for (i = 0; i < hash->size; i++) {
 723                 head = &hash->table[i];
 724
 725                 hlist_for_each_entry(bucket, walk, head, hlist) {
 726                         orig_node = bucket->data;
 727
 728                         /* if it's a vis server and reachable, send it. */
 729                         if ((!orig_node) || (!orig_node->router))
 730                                 continue;
 731                         if (!(orig_node->flags & VIS_SERVER))
 732                                 continue;
 733                         /* don't send it if we already received the packet from
 734                         * this node. */
 735                         if (recv_list_is_in(bat_priv, &info->recv_list,
 736                                             orig_node->orig))
 737                                 continue;
 738
 739                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 740                         batman_if = orig_node->router->if_incoming;
 741                         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 742                         spin_unlock_bh(&bat_priv->orig_hash_lock);
 743
 744                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 745                         if (skb)
 746                                 send_skb_packet(skb, batman_if, dstaddr);
 747
 748                         spin_lock_bh(&bat_priv->orig_hash_lock);
 749                 }
 750
 751         }
 752
 753         spin_unlock_bh(&bat_priv->orig_hash_lock);
 754 }
 755
 756 static void unicast_vis_packet(struct bat_priv *bat_priv,
 757                                struct vis_info *info)
 758 {
 759         struct orig_node *orig_node;
 760         struct sk_buff *skb;
 761         struct vis_packet *packet;
 762         struct batman_if *batman_if;
 763         uint8_t dstaddr[ETH_ALEN];
 764
 765         spin_lock_bh(&bat_priv->orig_hash_lock);
 766         packet = (struct vis_packet *)info->skb_packet->data;
 767         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 768                                                    compare_orig, choose_orig,
 769                                                    packet->target_orig));
 770
 771         if ((!orig_node) || (!orig_node->router))
 772                 goto out;
 773
 774         /* don't lock while sending the packets ... we therefore
 775          * copy the required data before sending */
 776         batman_if = orig_node->router->if_incoming;
 777         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 778         spin_unlock_bh(&bat_priv->orig_hash_lock);
 779
 780         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 781         if (skb)
 782                 send_skb_packet(skb, batman_if, dstaddr);
 783
 784         return;
 785
 786 out:
 787         spin_unlock_bh(&bat_priv->orig_hash_lock);
 788 }
 789
 790 /* only send one vis packet. called from send_vis_packets() */
 791 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 792 {
 793         struct vis_packet *packet;
 794
 795         packet = (struct vis_packet *)info->skb_packet->data;
 796         if (packet->ttl < 2) {
 797                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 798                 return;
 799         }
 800
 801         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 802                ETH_ALEN);
 803         packet->ttl--;
 804
 805         if (is_broadcast_ether_addr(packet->target_orig))
 806                 broadcast_vis_packet(bat_priv, info);
 807         else
 808                 unicast_vis_packet(bat_priv, info);
 809         packet->ttl++; /* restore TTL */
 810 }
 811
 812 /* called from timer; send (and maybe generate) vis packet. */
 813 static void send_vis_packets(struct work_struct *work)
 814 {
 815         struct delayed_work *delayed_work =
 816                 container_of(work, struct delayed_work, work);
 817         struct bat_priv *bat_priv =
 818                 container_of(delayed_work, struct bat_priv, vis_work);
 819         struct vis_info *info;
 820
 821         spin_lock_bh(&bat_priv->vis_hash_lock);
 822         purge_vis_packets(bat_priv);
 823
 824         if (generate_vis_packet(bat_priv) == 0) {
 825                 /* schedule if generation was successful */
 826                 send_list_add(bat_priv, bat_priv->my_vis_info);
 827         }
 828
 829         while (!list_empty(&bat_priv->vis_send_list)) {
 830                 info = list_first_entry(&bat_priv->vis_send_list,
 831                                         typeof(*info), send_list);
 832
 833                 kref_get(&info->refcount);
 834                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 835
 836                 if (bat_priv->primary_if)
 837                         send_vis_packet(bat_priv, info);
 838
 839                 spin_lock_bh(&bat_priv->vis_hash_lock);
 840                 send_list_del(info);
 841                 kref_put(&info->refcount, free_info);
 842         }
 843         spin_unlock_bh(&bat_priv->vis_hash_lock);
 844         start_vis_timer(bat_priv);
 845 }
 846
 847 /* init the vis server. this may only be called when if_list is already
 848  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 849 int vis_init(struct bat_priv *bat_priv)
 850 {
 851         struct vis_packet *packet;
 852         int hash_added;
 853
 854         if (bat_priv->vis_hash)
 855                 return 1;
 856
 857         spin_lock_bh(&bat_priv->vis_hash_lock);
 858
 859         bat_priv->vis_hash = hash_new(256);
 860         if (!bat_priv->vis_hash) {
 861                 pr_err("Can't initialize vis_hash\n");
 862                 goto err;
 863         }
 864
 865         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 866         if (!bat_priv->my_vis_info) {
 867                 pr_err("Can't initialize vis packet\n");
 868                 goto err;
 869         }
 870
 871         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 872                                                 sizeof(struct vis_packet) +
 873                                                 MAX_VIS_PACKET_SIZE +
 874                                                 sizeof(struct ethhdr));
 875         if (!bat_priv->my_vis_info->skb_packet)
 876                 goto free_info;
 877
 878         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 879         packet = (struct vis_packet *)skb_put(
 880                                         bat_priv->my_vis_info->skb_packet,
 881                                         sizeof(struct vis_packet));
 882
 883         /* prefill the vis info */
 884         bat_priv->my_vis_info->first_seen = jiffies -
 885                                                 msecs_to_jiffies(VIS_INTERVAL);
 886         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 887         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 888         kref_init(&bat_priv->my_vis_info->refcount);
 889         bat_priv->my_vis_info->bat_priv = bat_priv;
 890         packet->version = COMPAT_VERSION;
 891         packet->packet_type = BAT_VIS;
 892         packet->ttl = TTL;
 893         packet->seqno = 0;
 894         packet->entries = 0;
 895
 896         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 897
 898         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 899                               bat_priv->my_vis_info);
 900         if (hash_added < 0) {
 901                 pr_err("Can't add own vis packet into hash\n");
 902                 /* not in hash, need to remove it manually. */
 903                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 904                 goto err;
 905         }
 906
 907         spin_unlock_bh(&bat_priv->vis_hash_lock);
 908         start_vis_timer(bat_priv);
 909         return 1;
 910
 911 free_info:
 912         kfree(bat_priv->my_vis_info);
 913         bat_priv->my_vis_info = NULL;
 914 err:
 915         spin_unlock_bh(&bat_priv->vis_hash_lock);
 916         vis_quit(bat_priv);
 917         return 0;
 918 }
 919
 920 /* Decrease the reference count on a hash item info */
 921 static void free_info_ref(void *data, void *arg)
 922 {
 923         struct vis_info *info = data;
 924
 925         send_list_del(info);
 926         kref_put(&info->refcount, free_info);
 927 }
 928
 929 /* shutdown vis-server */
 930 void vis_quit(struct bat_priv *bat_priv)
 931 {
 932         if (!bat_priv->vis_hash)
 933                 return;
 934
 935         cancel_delayed_work_sync(&bat_priv->vis_work);
 936
 937         spin_lock_bh(&bat_priv->vis_hash_lock);
 938         /* properly remove, kill timers ... */
 939         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 940         bat_priv->vis_hash = NULL;
 941         bat_priv->my_vis_info = NULL;
 942         spin_unlock_bh(&bat_priv->vis_hash_lock);
 943 }
 944
 945 /* schedule packets for (re)transmission */
 946 static void start_vis_timer(struct bat_priv *bat_priv)
 947 {
 948         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 949         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 950                            msecs_to_jiffies(VIS_INTERVAL));
 951 }