drivers/staging/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2010 B.A.T.M.A.N. contributors:
   3  *
   4  * Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "translation-table.h"
  25 #include "vis.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "hash.h"
  29
  30 #define MAX_VIS_PACKET_SIZE 1000
  31
  32 /* Returns the smallest signed integer in two's complement with the sizeof x */
  33 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  34
  35 /* Checks if a sequence number x is a predecessor/successor of y.
  36  * they handle overflows/underflows and can correctly check for a
  37  * predecessor/successor unless the variable sequence number has grown by
  38  * more then 2**(bitwidth(x)-1)-1.
  39  * This means that for a uint8_t with the maximum value 255, it would think:
  40  *  - when adding nothing - it is neither a predecessor nor a successor
  41  *  - before adding more than 127 to the starting value - it is a predecessor,
  42  *  - when adding 128 - it is neither a predecessor nor a successor,
  43  *  - after adding more than 127 to the starting value - it is a successor */
  44 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  45                         _dummy > smallest_signed_int(_dummy); })
  46 #define seq_after(x, y) seq_before(y, x)
  47
  48 static void start_vis_timer(struct bat_priv *bat_priv);
  49
  50 /* free the info */
  51 static void free_info(struct kref *ref)
  52 {
  53         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  54         struct bat_priv *bat_priv = info->bat_priv;
  55         struct recvlist_node *entry, *tmp;
  56         unsigned long flags;
  57
  58         list_del_init(&info->send_list);
  59         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
  60         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  61                 list_del(&entry->list);
  62                 kfree(entry);
  63         }
  64
  65         spin_unlock_irqrestore(&bat_priv->vis_list_lock, flags);
  66         kfree_skb(info->skb_packet);
  67 }
  68
  69 /* Compare two vis packets, used by the hashing algorithm */
  70 static int vis_info_cmp(void *data1, void *data2)
  71 {
  72         struct vis_info *d1, *d2;
  73         struct vis_packet *p1, *p2;
  74         d1 = data1;
  75         d2 = data2;
  76         p1 = (struct vis_packet *)d1->skb_packet->data;
  77         p2 = (struct vis_packet *)d2->skb_packet->data;
  78         return compare_orig(p1->vis_orig, p2->vis_orig);
  79 }
  80
  81 /* hash function to choose an entry in a hash table of given size */
  82 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  83 static int vis_info_choose(void *data, int size)
  84 {
  85         struct vis_info *vis_info = data;
  86         struct vis_packet *packet;
  87         unsigned char *key;
  88         uint32_t hash = 0;
  89         size_t i;
  90
  91         packet = (struct vis_packet *)vis_info->skb_packet->data;
  92         key = packet->vis_orig;
  93         for (i = 0; i < ETH_ALEN; i++) {
  94                 hash += key[i];
  95                 hash += (hash << 10);
  96                 hash ^= (hash >> 6);
  97         }
  98
  99         hash += (hash << 3);
 100         hash ^= (hash >> 11);
 101         hash += (hash << 15);
 102
 103         return hash % size;
 104 }
 105
 106 /* insert interface to the list of interfaces of one originator, if it
 107  * does not already exist in the list */
 108 static void vis_data_insert_interface(const uint8_t *interface,
 109                                       struct hlist_head *if_list,
 110                                       bool primary)
 111 {
 112         struct if_list_entry *entry;
 113         struct hlist_node *pos;
 114
 115         hlist_for_each_entry(entry, pos, if_list, list) {
 116                 if (compare_orig(entry->addr, (void *)interface))
 117                         return;
 118         }
 119
 120         /* its a new address, add it to the list */
 121         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 122         if (!entry)
 123                 return;
 124         memcpy(entry->addr, interface, ETH_ALEN);
 125         entry->primary = primary;
 126         hlist_add_head(&entry->list, if_list);
 127 }
 128
 129 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
 130 {
 131         struct if_list_entry *entry;
 132         struct hlist_node *pos;
 133         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
 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         HASHIT(hashit);
 179         HASHIT(hashit_count);
 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         HLIST_HEAD(vis_if_list);
 186         struct if_list_entry *entry;
 187         struct hlist_node *pos, *n;
 188         int i;
 189         unsigned long flags;
 190         int vis_server = atomic_read(&bat_priv->vis_mode);
 191         size_t buff_pos, buf_size;
 192         char *buff;
 193
 194         if ((!bat_priv->primary_if) ||
 195             (vis_server == VIS_TYPE_CLIENT_UPDATE))
 196                 return 0;
 197
 198         buf_size = 1;
 199         /* Estimate length */
 200         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 201         while (hash_iterate(bat_priv->vis_hash, &hashit_count)) {
 202                 info = hashit_count.bucket->data;
 203                 packet = (struct vis_packet *)info->skb_packet->data;
 204                 entries = (struct vis_info_entry *)
 205                           ((char *)packet + sizeof(struct vis_packet));
 206
 207                 for (i = 0; i < packet->entries; i++) {
 208                         if (entries[i].quality == 0)
 209                                 continue;
 210                         vis_data_insert_interface(entries[i].src, &vis_if_list,
 211                                 compare_orig(entries[i].src, packet->vis_orig));
 212                 }
 213
 214                 hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 215                         buf_size += 18 + 26 * packet->entries;
 216
 217                         /* add primary/secondary records */
 218                         if (compare_orig(entry->addr, packet->vis_orig))
 219                                 buf_size +=
 220                                         vis_data_count_prim_sec(&vis_if_list);
 221
 222                         buf_size += 1;
 223                 }
 224
 225                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 226                         hlist_del(&entry->list);
 227                         kfree(entry);
 228                 }
 229         }
 230
 231         buff = kmalloc(buf_size, GFP_ATOMIC);
 232         if (!buff) {
 233                 spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 234                 return -ENOMEM;
 235         }
 236         buff[0] = '\0';
 237         buff_pos = 0;
 238
 239         while (hash_iterate(bat_priv->vis_hash, &hashit)) {
 240                 info = hashit.bucket->data;
 241                 packet = (struct vis_packet *)info->skb_packet->data;
 242                 entries = (struct vis_info_entry *)
 243                           ((char *)packet + sizeof(struct vis_packet));
 244
 245                 for (i = 0; i < packet->entries; i++) {
 246                         if (entries[i].quality == 0)
 247                                 continue;
 248                         vis_data_insert_interface(entries[i].src, &vis_if_list,
 249                                 compare_orig(entries[i].src, packet->vis_orig));
 250                 }
 251
 252                 hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 253                         buff_pos += sprintf(buff + buff_pos, "%pM,",
 254                                             entry->addr);
 255
 256                         for (i = 0; i < packet->entries; i++)
 257                                 buff_pos += vis_data_read_entry(buff + buff_pos,
 258                                                                 &entries[i],
 259                                                                 entry->addr,
 260                                                                 entry->primary);
 261
 262                         /* add primary/secondary records */
 263                         if (compare_orig(entry->addr, packet->vis_orig))
 264                                 buff_pos +=
 265                                         vis_data_read_prim_sec(buff + buff_pos,
 266                                                                &vis_if_list);
 267
 268                         buff_pos += sprintf(buff + buff_pos, "\n");
 269                 }
 270
 271                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 272                         hlist_del(&entry->list);
 273                         kfree(entry);
 274                 }
 275         }
 276
 277         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 278
 279         seq_printf(seq, "%s", buff);
 280         kfree(buff);
 281
 282         return 0;
 283 }
 284
 285 /* add the info packet to the send list, if it was not
 286  * already linked in. */
 287 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 288 {
 289         if (list_empty(&info->send_list)) {
 290                 kref_get(&info->refcount);
 291                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 292         }
 293 }
 294
 295 /* delete the info packet from the send list, if it was
 296  * linked in. */
 297 static void send_list_del(struct vis_info *info)
 298 {
 299         if (!list_empty(&info->send_list)) {
 300                 list_del_init(&info->send_list);
 301                 kref_put(&info->refcount, free_info);
 302         }
 303 }
 304
 305 /* tries to add one entry to the receive list. */
 306 static void recv_list_add(struct bat_priv *bat_priv,
 307                           struct list_head *recv_list, char *mac)
 308 {
 309         struct recvlist_node *entry;
 310         unsigned long flags;
 311
 312         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 313         if (!entry)
 314                 return;
 315
 316         memcpy(entry->mac, mac, ETH_ALEN);
 317         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
 318         list_add_tail(&entry->list, recv_list);
 319         spin_unlock_irqrestore(&bat_priv->vis_list_lock, flags);
 320 }
 321
 322 /* returns 1 if this mac is in the recv_list */
 323 static int recv_list_is_in(struct bat_priv *bat_priv,
 324                            struct list_head *recv_list, char *mac)
 325 {
 326         struct recvlist_node *entry;
 327         unsigned long flags;
 328
 329         spin_lock_irqsave(&bat_priv->vis_list_lock, flags);
 330         list_for_each_entry(entry, recv_list, list) {
 331                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
 332                         spin_unlock_irqrestore(&bat_priv->vis_list_lock,
 333                                                flags);
 334                         return 1;
 335                 }
 336         }
 337         spin_unlock_irqrestore(&bat_priv->vis_list_lock, flags);
 338         return 0;
 339 }
 340
 341 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 342  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 343  * is newer than old entries in the hash. */
 344 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 345                                    struct vis_packet *vis_packet,
 346                                    int vis_info_len, int *is_new,
 347                                    int make_broadcast)
 348 {
 349         struct vis_info *info, *old_info;
 350         struct vis_packet *search_packet, *old_packet;
 351         struct vis_info search_elem;
 352         struct vis_packet *packet;
 353
 354         *is_new = 0;
 355         /* sanity check */
 356         if (!bat_priv->vis_hash)
 357                 return NULL;
 358
 359         /* see if the packet is already in vis_hash */
 360         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
 361         if (!search_elem.skb_packet)
 362                 return NULL;
 363         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 364                                                      sizeof(struct vis_packet));
 365
 366         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 367         old_info = hash_find(bat_priv->vis_hash, &search_elem);
 368         kfree_skb(search_elem.skb_packet);
 369
 370         if (old_info != NULL) {
 371                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 372                 if (!seq_after(ntohl(vis_packet->seqno),
 373                                ntohl(old_packet->seqno))) {
 374                         if (old_packet->seqno == vis_packet->seqno) {
 375                                 recv_list_add(bat_priv, &old_info->recv_list,
 376                                               vis_packet->sender_orig);
 377                                 return old_info;
 378                         } else {
 379                                 /* newer packet is already in hash. */
 380                                 return NULL;
 381                         }
 382                 }
 383                 /* remove old entry */
 384                 hash_remove(bat_priv->vis_hash, old_info);
 385                 send_list_del(old_info);
 386                 kref_put(&old_info->refcount, free_info);
 387         }
 388
 389         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 390         if (!info)
 391                 return NULL;
 392
 393         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 394                                          vis_info_len + sizeof(struct ethhdr));
 395         if (!info->skb_packet) {
 396                 kfree(info);
 397                 return NULL;
 398         }
 399         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 400         packet = (struct vis_packet *)skb_put(info->skb_packet,
 401                                               sizeof(struct vis_packet) +
 402                                               vis_info_len);
 403
 404         kref_init(&info->refcount);
 405         INIT_LIST_HEAD(&info->send_list);
 406         INIT_LIST_HEAD(&info->recv_list);
 407         info->first_seen = jiffies;
 408         info->bat_priv = bat_priv;
 409         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
 410
 411         /* initialize and add new packet. */
 412         *is_new = 1;
 413
 414         /* Make it a broadcast packet, if required */
 415         if (make_broadcast)
 416                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 417
 418         /* repair if entries is longer than packet. */
 419         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 420                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 421
 422         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 423
 424         /* try to add it */
 425         if (hash_add(bat_priv->vis_hash, info) < 0) {
 426                 /* did not work (for some reason) */
 427                 kref_put(&old_info->refcount, free_info);
 428                 info = NULL;
 429         }
 430
 431         return info;
 432 }
 433
 434 /* handle the server sync packet, forward if needed. */
 435 void receive_server_sync_packet(struct bat_priv *bat_priv,
 436                                 struct vis_packet *vis_packet,
 437                                 int vis_info_len)
 438 {
 439         struct vis_info *info;
 440         int is_new, make_broadcast;
 441         unsigned long flags;
 442         int vis_server = atomic_read(&bat_priv->vis_mode);
 443
 444         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 445
 446         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 447         info = add_packet(bat_priv, vis_packet, vis_info_len,
 448                           &is_new, make_broadcast);
 449         if (!info)
 450                 goto end;
 451
 452         /* only if we are server ourselves and packet is newer than the one in
 453          * hash.*/
 454         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 455                 send_list_add(bat_priv, info);
 456 end:
 457         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 458 }
 459
 460 /* handle an incoming client update packet and schedule forward if needed. */
 461 void receive_client_update_packet(struct bat_priv *bat_priv,
 462                                   struct vis_packet *vis_packet,
 463                                   int vis_info_len)
 464 {
 465         struct vis_info *info;
 466         struct vis_packet *packet;
 467         int is_new;
 468         unsigned long flags;
 469         int vis_server = atomic_read(&bat_priv->vis_mode);
 470         int are_target = 0;
 471
 472         /* clients shall not broadcast. */
 473         if (is_bcast(vis_packet->target_orig))
 474                 return;
 475
 476         /* Are we the target for this VIS packet? */
 477         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 478             is_my_mac(vis_packet->target_orig))
 479                 are_target = 1;
 480
 481         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 482         info = add_packet(bat_priv, vis_packet, vis_info_len,
 483                           &is_new, are_target);
 484
 485         if (!info)
 486                 goto end;
 487         /* note that outdated packets will be dropped at this point. */
 488
 489         packet = (struct vis_packet *)info->skb_packet->data;
 490
 491         /* send only if we're the target server or ... */
 492         if (are_target && is_new) {
 493                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 494                 send_list_add(bat_priv, info);
 495
 496                 /* ... we're not the recipient (and thus need to forward). */
 497         } else if (!is_my_mac(packet->target_orig)) {
 498                 send_list_add(bat_priv, info);
 499         }
 500
 501 end:
 502         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 503 }
 504
 505 /* Walk the originators and find the VIS server with the best tq. Set the packet
 506  * address to its address and return the best_tq.
 507  *
 508  * Must be called with the originator hash locked */
 509 static int find_best_vis_server(struct bat_priv *bat_priv,
 510                                 struct vis_info *info)
 511 {
 512         HASHIT(hashit);
 513         struct orig_node *orig_node;
 514         struct vis_packet *packet;
 515         int best_tq = -1;
 516
 517         packet = (struct vis_packet *)info->skb_packet->data;
 518
 519         while (hash_iterate(bat_priv->orig_hash, &hashit)) {
 520                 orig_node = hashit.bucket->data;
 521                 if ((orig_node) && (orig_node->router) &&
 522                     (orig_node->flags & VIS_SERVER) &&
 523                     (orig_node->router->tq_avg > best_tq)) {
 524                         best_tq = orig_node->router->tq_avg;
 525                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 526                 }
 527         }
 528         return best_tq;
 529 }
 530
 531 /* Return true if the vis packet is full. */
 532 static bool vis_packet_full(struct vis_info *info)
 533 {
 534         struct vis_packet *packet;
 535         packet = (struct vis_packet *)info->skb_packet->data;
 536
 537         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 538                 < packet->entries + 1)
 539                 return true;
 540         return false;
 541 }
 542
 543 /* generates a packet of own vis data,
 544  * returns 0 on success, -1 if no packet could be generated */
 545 static int generate_vis_packet(struct bat_priv *bat_priv)
 546 {
 547         HASHIT(hashit_local);
 548         HASHIT(hashit_global);
 549         struct orig_node *orig_node;
 550         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 551         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 552         struct vis_info_entry *entry;
 553         struct hna_local_entry *hna_local_entry;
 554         int best_tq = -1;
 555         unsigned long flags;
 556
 557         info->first_seen = jiffies;
 558         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 559
 560         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 561         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 562         packet->ttl = TTL;
 563         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 564         packet->entries = 0;
 565         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 566
 567         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 568                 best_tq = find_best_vis_server(bat_priv, info);
 569
 570                 if (best_tq < 0) {
 571                         spin_unlock_irqrestore(&bat_priv->orig_hash_lock,
 572                                                flags);
 573                         return -1;
 574                 }
 575         }
 576
 577         while (hash_iterate(bat_priv->orig_hash, &hashit_global)) {
 578                 orig_node = hashit_global.bucket->data;
 579
 580                 if (!orig_node->router)
 581                         continue;
 582
 583                 if (!compare_orig(orig_node->router->addr, orig_node->orig))
 584                         continue;
 585
 586                 if (orig_node->router->if_incoming->if_status != IF_ACTIVE)
 587                         continue;
 588
 589                 if (orig_node->router->tq_avg < 1)
 590                         continue;
 591
 592                 /* fill one entry into buffer. */
 593                 entry = (struct vis_info_entry *)
 594                                 skb_put(info->skb_packet, sizeof(*entry));
 595                 memcpy(entry->src,
 596                        orig_node->router->if_incoming->net_dev->dev_addr,
 597                        ETH_ALEN);
 598                 memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 599                 entry->quality = orig_node->router->tq_avg;
 600                 packet->entries++;
 601
 602                 if (vis_packet_full(info)) {
 603                         spin_unlock_irqrestore(
 604                                         &bat_priv->orig_hash_lock, flags);
 605                         return 0;
 606                 }
 607         }
 608
 609         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 610
 611         spin_lock_irqsave(&bat_priv->hna_lhash_lock, flags);
 612         while (hash_iterate(bat_priv->hna_local_hash, &hashit_local)) {
 613                 hna_local_entry = hashit_local.bucket->data;
 614                 entry = (struct vis_info_entry *)skb_put(info->skb_packet,
 615                                                          sizeof(*entry));
 616                 memset(entry->src, 0, ETH_ALEN);
 617                 memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
 618                 entry->quality = 0; /* 0 means HNA */
 619                 packet->entries++;
 620
 621                 if (vis_packet_full(info)) {
 622                         spin_unlock_irqrestore(&bat_priv->hna_lhash_lock,
 623                                                flags);
 624                         return 0;
 625                 }
 626         }
 627
 628         spin_unlock_irqrestore(&bat_priv->hna_lhash_lock, flags);
 629         return 0;
 630 }
 631
 632 /* free old vis packets. Must be called with this vis_hash_lock
 633  * held */
 634 static void purge_vis_packets(struct bat_priv *bat_priv)
 635 {
 636         HASHIT(hashit);
 637         struct vis_info *info;
 638
 639         while (hash_iterate(bat_priv->vis_hash, &hashit)) {
 640                 info = hashit.bucket->data;
 641
 642                 /* never purge own data. */
 643                 if (info == bat_priv->my_vis_info)
 644                         continue;
 645
 646                 if (time_after(jiffies,
 647                                info->first_seen + VIS_TIMEOUT * HZ)) {
 648                         hash_remove_bucket(bat_priv->vis_hash, &hashit);
 649                         send_list_del(info);
 650                         kref_put(&info->refcount, free_info);
 651                 }
 652         }
 653 }
 654
 655 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 656                                  struct vis_info *info)
 657 {
 658         HASHIT(hashit);
 659         struct orig_node *orig_node;
 660         struct vis_packet *packet;
 661         struct sk_buff *skb;
 662         unsigned long flags;
 663         struct batman_if *batman_if;
 664         uint8_t dstaddr[ETH_ALEN];
 665
 666
 667         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 668         packet = (struct vis_packet *)info->skb_packet->data;
 669
 670         /* send to all routers in range. */
 671         while (hash_iterate(bat_priv->orig_hash, &hashit)) {
 672                 orig_node = hashit.bucket->data;
 673
 674                 /* if it's a vis server and reachable, send it. */
 675                 if ((!orig_node) || (!orig_node->router))
 676                         continue;
 677                 if (!(orig_node->flags & VIS_SERVER))
 678                         continue;
 679                 /* don't send it if we already received the packet from
 680                  * this node. */
 681                 if (recv_list_is_in(bat_priv, &info->recv_list,
 682                                                         orig_node->orig))
 683                         continue;
 684
 685                 memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 686                 batman_if = orig_node->router->if_incoming;
 687                 memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 688                 spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 689
 690                 skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 691                 if (skb)
 692                         send_skb_packet(skb, batman_if, dstaddr);
 693
 694                 spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 695
 696         }
 697
 698         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 699 }
 700
 701 static void unicast_vis_packet(struct bat_priv *bat_priv,
 702                                struct vis_info *info)
 703 {
 704         struct orig_node *orig_node;
 705         struct sk_buff *skb;
 706         struct vis_packet *packet;
 707         unsigned long flags;
 708         struct batman_if *batman_if;
 709         uint8_t dstaddr[ETH_ALEN];
 710
 711         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 712         packet = (struct vis_packet *)info->skb_packet->data;
 713         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 714                                                    packet->target_orig));
 715
 716         if ((!orig_node) || (!orig_node->router))
 717                 goto out;
 718
 719         /* don't lock while sending the packets ... we therefore
 720          * copy the required data before sending */
 721         batman_if = orig_node->router->if_incoming;
 722         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 723         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 724
 725         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 726         if (skb)
 727                 send_skb_packet(skb, batman_if, dstaddr);
 728
 729         return;
 730
 731 out:
 732         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 733 }
 734
 735 /* only send one vis packet. called from send_vis_packets() */
 736 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 737 {
 738         struct vis_packet *packet;
 739
 740         packet = (struct vis_packet *)info->skb_packet->data;
 741         if (packet->ttl < 2) {
 742                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 743                 return;
 744         }
 745
 746         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
 747                ETH_ALEN);
 748         packet->ttl--;
 749
 750         if (is_bcast(packet->target_orig))
 751                 broadcast_vis_packet(bat_priv, info);
 752         else
 753                 unicast_vis_packet(bat_priv, info);
 754         packet->ttl++; /* restore TTL */
 755 }
 756
 757 /* called from timer; send (and maybe generate) vis packet. */
 758 static void send_vis_packets(struct work_struct *work)
 759 {
 760         struct delayed_work *delayed_work =
 761                 container_of(work, struct delayed_work, work);
 762         struct bat_priv *bat_priv =
 763                 container_of(delayed_work, struct bat_priv, vis_work);
 764         struct vis_info *info, *temp;
 765         unsigned long flags;
 766
 767         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 768         purge_vis_packets(bat_priv);
 769
 770         if (generate_vis_packet(bat_priv) == 0) {
 771                 /* schedule if generation was successful */
 772                 send_list_add(bat_priv, bat_priv->my_vis_info);
 773         }
 774
 775         list_for_each_entry_safe(info, temp, &bat_priv->vis_send_list,
 776                                  send_list) {
 777
 778                 kref_get(&info->refcount);
 779                 spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 780
 781                 if (bat_priv->primary_if)
 782                         send_vis_packet(bat_priv, info);
 783
 784                 spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 785                 send_list_del(info);
 786                 kref_put(&info->refcount, free_info);
 787         }
 788         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 789         start_vis_timer(bat_priv);
 790 }
 791
 792 /* init the vis server. this may only be called when if_list is already
 793  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 794 int vis_init(struct bat_priv *bat_priv)
 795 {
 796         struct vis_packet *packet;
 797         unsigned long flags;
 798
 799         if (bat_priv->vis_hash)
 800                 return 1;
 801
 802         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 803
 804         bat_priv->vis_hash = hash_new(256, vis_info_cmp, vis_info_choose);
 805         if (!bat_priv->vis_hash) {
 806                 pr_err("Can't initialize vis_hash\n");
 807                 goto err;
 808         }
 809
 810         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 811         if (!bat_priv->my_vis_info) {
 812                 pr_err("Can't initialize vis packet\n");
 813                 goto err;
 814         }
 815
 816         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 817                                                 sizeof(struct vis_packet) +
 818                                                 MAX_VIS_PACKET_SIZE +
 819                                                 sizeof(struct ethhdr));
 820         if (!bat_priv->my_vis_info->skb_packet)
 821                 goto free_info;
 822
 823         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 824         packet = (struct vis_packet *)skb_put(
 825                                         bat_priv->my_vis_info->skb_packet,
 826                                         sizeof(struct vis_packet));
 827
 828         /* prefill the vis info */
 829         bat_priv->my_vis_info->first_seen = jiffies -
 830                                                 msecs_to_jiffies(VIS_INTERVAL);
 831         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 832         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 833         kref_init(&bat_priv->my_vis_info->refcount);
 834         bat_priv->my_vis_info->bat_priv = bat_priv;
 835         packet->version = COMPAT_VERSION;
 836         packet->packet_type = BAT_VIS;
 837         packet->ttl = TTL;
 838         packet->seqno = 0;
 839         packet->entries = 0;
 840
 841         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 842
 843         if (hash_add(bat_priv->vis_hash, bat_priv->my_vis_info) < 0) {
 844                 pr_err("Can't add own vis packet into hash\n");
 845                 /* not in hash, need to remove it manually. */
 846                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 847                 goto err;
 848         }
 849
 850         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 851         start_vis_timer(bat_priv);
 852         return 1;
 853
 854 free_info:
 855         kfree(bat_priv->my_vis_info);
 856         bat_priv->my_vis_info = NULL;
 857 err:
 858         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 859         vis_quit(bat_priv);
 860         return 0;
 861 }
 862
 863 /* Decrease the reference count on a hash item info */
 864 static void free_info_ref(void *data, void *arg)
 865 {
 866         struct vis_info *info = data;
 867
 868         send_list_del(info);
 869         kref_put(&info->refcount, free_info);
 870 }
 871
 872 /* shutdown vis-server */
 873 void vis_quit(struct bat_priv *bat_priv)
 874 {
 875         unsigned long flags;
 876         if (!bat_priv->vis_hash)
 877                 return;
 878
 879         cancel_delayed_work_sync(&bat_priv->vis_work);
 880
 881         spin_lock_irqsave(&bat_priv->vis_hash_lock, flags);
 882         /* properly remove, kill timers ... */
 883         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 884         bat_priv->vis_hash = NULL;
 885         bat_priv->my_vis_info = NULL;
 886         spin_unlock_irqrestore(&bat_priv->vis_hash_lock, flags);
 887 }
 888
 889 /* schedule packets for (re)transmission */
 890 static void start_vis_timer(struct bat_priv *bat_priv)
 891 {
 892         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 893         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 894                            msecs_to_jiffies(VIS_INTERVAL));
 895 }