net: introduce DST_NOPEER dst flag
[linux-2.6.git] / 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 static void start_vis_timer(struct bat_priv *bat_priv);
34
35 /* free the info */
36 static void free_info(struct kref *ref)
37 {
38         struct vis_info *info = container_of(ref, struct vis_info, refcount);
39         struct bat_priv *bat_priv = info->bat_priv;
40         struct recvlist_node *entry, *tmp;
41
42         list_del_init(&info->send_list);
43         spin_lock_bh(&bat_priv->vis_list_lock);
44         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
45                 list_del(&entry->list);
46                 kfree(entry);
47         }
48
49         spin_unlock_bh(&bat_priv->vis_list_lock);
50         kfree_skb(info->skb_packet);
51         kfree(info);
52 }
53
54 /* Compare two vis packets, used by the hashing algorithm */
55 static int vis_info_cmp(const struct hlist_node *node, const void *data2)
56 {
57         const struct vis_info *d1, *d2;
58         const struct vis_packet *p1, *p2;
59
60         d1 = container_of(node, struct vis_info, hash_entry);
61         d2 = data2;
62         p1 = (struct vis_packet *)d1->skb_packet->data;
63         p2 = (struct vis_packet *)d2->skb_packet->data;
64         return compare_eth(p1->vis_orig, p2->vis_orig);
65 }
66
67 /* hash function to choose an entry in a hash table of given size */
68 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
69 static int vis_info_choose(const void *data, int size)
70 {
71         const struct vis_info *vis_info = data;
72         const struct vis_packet *packet;
73         const unsigned char *key;
74         uint32_t hash = 0;
75         size_t i;
76
77         packet = (struct vis_packet *)vis_info->skb_packet->data;
78         key = packet->vis_orig;
79         for (i = 0; i < ETH_ALEN; i++) {
80                 hash += key[i];
81                 hash += (hash << 10);
82                 hash ^= (hash >> 6);
83         }
84
85         hash += (hash << 3);
86         hash ^= (hash >> 11);
87         hash += (hash << 15);
88
89         return hash % size;
90 }
91
92 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
93                                       const void *data)
94 {
95         struct hashtable_t *hash = bat_priv->vis_hash;
96         struct hlist_head *head;
97         struct hlist_node *node;
98         struct vis_info *vis_info, *vis_info_tmp = NULL;
99         int index;
100
101         if (!hash)
102                 return NULL;
103
104         index = vis_info_choose(data, hash->size);
105         head = &hash->table[index];
106
107         rcu_read_lock();
108         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
109                 if (!vis_info_cmp(node, data))
110                         continue;
111
112                 vis_info_tmp = vis_info;
113                 break;
114         }
115         rcu_read_unlock();
116
117         return vis_info_tmp;
118 }
119
120 /* insert interface to the list of interfaces of one originator, if it
121  * does not already exist in the list */
122 static void vis_data_insert_interface(const uint8_t *interface,
123                                       struct hlist_head *if_list,
124                                       bool primary)
125 {
126         struct if_list_entry *entry;
127         struct hlist_node *pos;
128
129         hlist_for_each_entry(entry, pos, if_list, list) {
130                 if (compare_eth(entry->addr, interface))
131                         return;
132         }
133
134         /* its a new address, add it to the list */
135         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
136         if (!entry)
137                 return;
138         memcpy(entry->addr, interface, ETH_ALEN);
139         entry->primary = primary;
140         hlist_add_head(&entry->list, if_list);
141 }
142
143 static ssize_t vis_data_read_prim_sec(char *buff,
144                                       const struct hlist_head *if_list)
145 {
146         struct if_list_entry *entry;
147         struct hlist_node *pos;
148         size_t len = 0;
149
150         hlist_for_each_entry(entry, pos, if_list, list) {
151                 if (entry->primary)
152                         len += sprintf(buff + len, "PRIMARY, ");
153                 else
154                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
155         }
156
157         return len;
158 }
159
160 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
161 {
162         struct if_list_entry *entry;
163         struct hlist_node *pos;
164         size_t count = 0;
165
166         hlist_for_each_entry(entry, pos, if_list, list) {
167                 if (entry->primary)
168                         count += 9;
169                 else
170                         count += 23;
171         }
172
173         return count;
174 }
175
176 /* read an entry  */
177 static ssize_t vis_data_read_entry(char *buff,
178                                    const struct vis_info_entry *entry,
179                                    const uint8_t *src, bool primary)
180 {
181         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
182         if (primary && entry->quality == 0)
183                 return sprintf(buff, "TT %pM, ", entry->dest);
184         else if (compare_eth(entry->src, src))
185                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
186                                entry->quality);
187
188         return 0;
189 }
190
191 int vis_seq_print_text(struct seq_file *seq, void *offset)
192 {
193         struct hard_iface *primary_if;
194         struct hlist_node *node;
195         struct hlist_head *head;
196         struct vis_info *info;
197         struct vis_packet *packet;
198         struct vis_info_entry *entries;
199         struct net_device *net_dev = (struct net_device *)seq->private;
200         struct bat_priv *bat_priv = netdev_priv(net_dev);
201         struct hashtable_t *hash = bat_priv->vis_hash;
202         HLIST_HEAD(vis_if_list);
203         struct if_list_entry *entry;
204         struct hlist_node *pos, *n;
205         int i, j, ret = 0;
206         int vis_server = atomic_read(&bat_priv->vis_mode);
207         size_t buff_pos, buf_size;
208         char *buff;
209         int compare;
210
211         primary_if = primary_if_get_selected(bat_priv);
212         if (!primary_if)
213                 goto out;
214
215         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
216                 goto out;
217
218         buf_size = 1;
219         /* Estimate length */
220         spin_lock_bh(&bat_priv->vis_hash_lock);
221         for (i = 0; i < hash->size; i++) {
222                 head = &hash->table[i];
223
224                 rcu_read_lock();
225                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
226                         packet = (struct vis_packet *)info->skb_packet->data;
227                         entries = (struct vis_info_entry *)
228                                 ((char *)packet + sizeof(*packet));
229
230                         for (j = 0; j < packet->entries; j++) {
231                                 if (entries[j].quality == 0)
232                                         continue;
233                                 compare =
234                                  compare_eth(entries[j].src, packet->vis_orig);
235                                 vis_data_insert_interface(entries[j].src,
236                                                           &vis_if_list,
237                                                           compare);
238                         }
239
240                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
241                                 buf_size += 18 + 26 * packet->entries;
242
243                                 /* add primary/secondary records */
244                                 if (compare_eth(entry->addr, packet->vis_orig))
245                                         buf_size +=
246                                           vis_data_count_prim_sec(&vis_if_list);
247
248                                 buf_size += 1;
249                         }
250
251                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
252                                                   list) {
253                                 hlist_del(&entry->list);
254                                 kfree(entry);
255                         }
256                 }
257                 rcu_read_unlock();
258         }
259
260         buff = kmalloc(buf_size, GFP_ATOMIC);
261         if (!buff) {
262                 spin_unlock_bh(&bat_priv->vis_hash_lock);
263                 ret = -ENOMEM;
264                 goto out;
265         }
266         buff[0] = '\0';
267         buff_pos = 0;
268
269         for (i = 0; i < hash->size; i++) {
270                 head = &hash->table[i];
271
272                 rcu_read_lock();
273                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
274                         packet = (struct vis_packet *)info->skb_packet->data;
275                         entries = (struct vis_info_entry *)
276                                 ((char *)packet + sizeof(*packet));
277
278                         for (j = 0; j < packet->entries; j++) {
279                                 if (entries[j].quality == 0)
280                                         continue;
281                                 compare =
282                                  compare_eth(entries[j].src, packet->vis_orig);
283                                 vis_data_insert_interface(entries[j].src,
284                                                           &vis_if_list,
285                                                           compare);
286                         }
287
288                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
289                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
290                                                 entry->addr);
291
292                                 for (j = 0; j < packet->entries; j++)
293                                         buff_pos += vis_data_read_entry(
294                                                         buff + buff_pos,
295                                                         &entries[j],
296                                                         entry->addr,
297                                                         entry->primary);
298
299                                 /* add primary/secondary records */
300                                 if (compare_eth(entry->addr, packet->vis_orig))
301                                         buff_pos +=
302                                          vis_data_read_prim_sec(buff + buff_pos,
303                                                                 &vis_if_list);
304
305                                 buff_pos += sprintf(buff + buff_pos, "\n");
306                         }
307
308                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
309                                                   list) {
310                                 hlist_del(&entry->list);
311                                 kfree(entry);
312                         }
313                 }
314                 rcu_read_unlock();
315         }
316
317         spin_unlock_bh(&bat_priv->vis_hash_lock);
318
319         seq_printf(seq, "%s", buff);
320         kfree(buff);
321
322 out:
323         if (primary_if)
324                 hardif_free_ref(primary_if);
325         return ret;
326 }
327
328 /* add the info packet to the send list, if it was not
329  * already linked in. */
330 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
331 {
332         if (list_empty(&info->send_list)) {
333                 kref_get(&info->refcount);
334                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
335         }
336 }
337
338 /* delete the info packet from the send list, if it was
339  * linked in. */
340 static void send_list_del(struct vis_info *info)
341 {
342         if (!list_empty(&info->send_list)) {
343                 list_del_init(&info->send_list);
344                 kref_put(&info->refcount, free_info);
345         }
346 }
347
348 /* tries to add one entry to the receive list. */
349 static void recv_list_add(struct bat_priv *bat_priv,
350                           struct list_head *recv_list, const char *mac)
351 {
352         struct recvlist_node *entry;
353
354         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
355         if (!entry)
356                 return;
357
358         memcpy(entry->mac, mac, ETH_ALEN);
359         spin_lock_bh(&bat_priv->vis_list_lock);
360         list_add_tail(&entry->list, recv_list);
361         spin_unlock_bh(&bat_priv->vis_list_lock);
362 }
363
364 /* returns 1 if this mac is in the recv_list */
365 static int recv_list_is_in(struct bat_priv *bat_priv,
366                            const struct list_head *recv_list, const char *mac)
367 {
368         const struct recvlist_node *entry;
369
370         spin_lock_bh(&bat_priv->vis_list_lock);
371         list_for_each_entry(entry, recv_list, list) {
372                 if (compare_eth(entry->mac, mac)) {
373                         spin_unlock_bh(&bat_priv->vis_list_lock);
374                         return 1;
375                 }
376         }
377         spin_unlock_bh(&bat_priv->vis_list_lock);
378         return 0;
379 }
380
381 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
382  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
383  * is newer than old entries in the hash. */
384 static struct vis_info *add_packet(struct bat_priv *bat_priv,
385                                    struct vis_packet *vis_packet,
386                                    int vis_info_len, int *is_new,
387                                    int make_broadcast)
388 {
389         struct vis_info *info, *old_info;
390         struct vis_packet *search_packet, *old_packet;
391         struct vis_info search_elem;
392         struct vis_packet *packet;
393         int hash_added;
394
395         *is_new = 0;
396         /* sanity check */
397         if (!bat_priv->vis_hash)
398                 return NULL;
399
400         /* see if the packet is already in vis_hash */
401         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
402         if (!search_elem.skb_packet)
403                 return NULL;
404         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
405                                                      sizeof(*search_packet));
406
407         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
408         old_info = vis_hash_find(bat_priv, &search_elem);
409         kfree_skb(search_elem.skb_packet);
410
411         if (old_info) {
412                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
413                 if (!seq_after(ntohl(vis_packet->seqno),
414                                ntohl(old_packet->seqno))) {
415                         if (old_packet->seqno == vis_packet->seqno) {
416                                 recv_list_add(bat_priv, &old_info->recv_list,
417                                               vis_packet->sender_orig);
418                                 return old_info;
419                         } else {
420                                 /* newer packet is already in hash. */
421                                 return NULL;
422                         }
423                 }
424                 /* remove old entry */
425                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
426                             old_info);
427                 send_list_del(old_info);
428                 kref_put(&old_info->refcount, free_info);
429         }
430
431         info = kmalloc(sizeof(*info), GFP_ATOMIC);
432         if (!info)
433                 return NULL;
434
435         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
436                                          sizeof(struct ethhdr));
437         if (!info->skb_packet) {
438                 kfree(info);
439                 return NULL;
440         }
441         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
442         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
443                                               + vis_info_len);
444
445         kref_init(&info->refcount);
446         INIT_LIST_HEAD(&info->send_list);
447         INIT_LIST_HEAD(&info->recv_list);
448         info->first_seen = jiffies;
449         info->bat_priv = bat_priv;
450         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
451
452         /* initialize and add new packet. */
453         *is_new = 1;
454
455         /* Make it a broadcast packet, if required */
456         if (make_broadcast)
457                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
458
459         /* repair if entries is longer than packet. */
460         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
461                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
462
463         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
464
465         /* try to add it */
466         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
467                               info, &info->hash_entry);
468         if (hash_added < 0) {
469                 /* did not work (for some reason) */
470                 kref_put(&info->refcount, free_info);
471                 info = NULL;
472         }
473
474         return info;
475 }
476
477 /* handle the server sync packet, forward if needed. */
478 void receive_server_sync_packet(struct bat_priv *bat_priv,
479                                 struct vis_packet *vis_packet,
480                                 int vis_info_len)
481 {
482         struct vis_info *info;
483         int is_new, make_broadcast;
484         int vis_server = atomic_read(&bat_priv->vis_mode);
485
486         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
487
488         spin_lock_bh(&bat_priv->vis_hash_lock);
489         info = add_packet(bat_priv, vis_packet, vis_info_len,
490                           &is_new, make_broadcast);
491         if (!info)
492                 goto end;
493
494         /* only if we are server ourselves and packet is newer than the one in
495          * hash.*/
496         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
497                 send_list_add(bat_priv, info);
498 end:
499         spin_unlock_bh(&bat_priv->vis_hash_lock);
500 }
501
502 /* handle an incoming client update packet and schedule forward if needed. */
503 void receive_client_update_packet(struct bat_priv *bat_priv,
504                                   struct vis_packet *vis_packet,
505                                   int vis_info_len)
506 {
507         struct vis_info *info;
508         struct vis_packet *packet;
509         int is_new;
510         int vis_server = atomic_read(&bat_priv->vis_mode);
511         int are_target = 0;
512
513         /* clients shall not broadcast. */
514         if (is_broadcast_ether_addr(vis_packet->target_orig))
515                 return;
516
517         /* Are we the target for this VIS packet? */
518         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
519             is_my_mac(vis_packet->target_orig))
520                 are_target = 1;
521
522         spin_lock_bh(&bat_priv->vis_hash_lock);
523         info = add_packet(bat_priv, vis_packet, vis_info_len,
524                           &is_new, are_target);
525
526         if (!info)
527                 goto end;
528         /* note that outdated packets will be dropped at this point. */
529
530         packet = (struct vis_packet *)info->skb_packet->data;
531
532         /* send only if we're the target server or ... */
533         if (are_target && is_new) {
534                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
535                 send_list_add(bat_priv, info);
536
537                 /* ... we're not the recipient (and thus need to forward). */
538         } else if (!is_my_mac(packet->target_orig)) {
539                 send_list_add(bat_priv, info);
540         }
541
542 end:
543         spin_unlock_bh(&bat_priv->vis_hash_lock);
544 }
545
546 /* Walk the originators and find the VIS server with the best tq. Set the packet
547  * address to its address and return the best_tq.
548  *
549  * Must be called with the originator hash locked */
550 static int find_best_vis_server(struct bat_priv *bat_priv,
551                                 struct vis_info *info)
552 {
553         struct hashtable_t *hash = bat_priv->orig_hash;
554         struct neigh_node *router;
555         struct hlist_node *node;
556         struct hlist_head *head;
557         struct orig_node *orig_node;
558         struct vis_packet *packet;
559         int best_tq = -1, i;
560
561         packet = (struct vis_packet *)info->skb_packet->data;
562
563         for (i = 0; i < hash->size; i++) {
564                 head = &hash->table[i];
565
566                 rcu_read_lock();
567                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
568                         router = orig_node_get_router(orig_node);
569                         if (!router)
570                                 continue;
571
572                         if ((orig_node->flags & VIS_SERVER) &&
573                             (router->tq_avg > best_tq)) {
574                                 best_tq = router->tq_avg;
575                                 memcpy(packet->target_orig, orig_node->orig,
576                                        ETH_ALEN);
577                         }
578                         neigh_node_free_ref(router);
579                 }
580                 rcu_read_unlock();
581         }
582
583         return best_tq;
584 }
585
586 /* Return true if the vis packet is full. */
587 static bool vis_packet_full(const struct vis_info *info)
588 {
589         const struct vis_packet *packet;
590         packet = (struct vis_packet *)info->skb_packet->data;
591
592         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
593                 < packet->entries + 1)
594                 return true;
595         return false;
596 }
597
598 /* generates a packet of own vis data,
599  * returns 0 on success, -1 if no packet could be generated */
600 static int generate_vis_packet(struct bat_priv *bat_priv)
601 {
602         struct hashtable_t *hash = bat_priv->orig_hash;
603         struct hlist_node *node;
604         struct hlist_head *head;
605         struct orig_node *orig_node;
606         struct neigh_node *router;
607         struct vis_info *info = bat_priv->my_vis_info;
608         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
609         struct vis_info_entry *entry;
610         struct tt_local_entry *tt_local_entry;
611         int best_tq = -1, i;
612
613         info->first_seen = jiffies;
614         packet->vis_type = atomic_read(&bat_priv->vis_mode);
615
616         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
617         packet->ttl = TTL;
618         packet->seqno = htonl(ntohl(packet->seqno) + 1);
619         packet->entries = 0;
620         skb_trim(info->skb_packet, sizeof(*packet));
621
622         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
623                 best_tq = find_best_vis_server(bat_priv, info);
624
625                 if (best_tq < 0)
626                         return -1;
627         }
628
629         for (i = 0; i < hash->size; i++) {
630                 head = &hash->table[i];
631
632                 rcu_read_lock();
633                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
634                         router = orig_node_get_router(orig_node);
635                         if (!router)
636                                 continue;
637
638                         if (!compare_eth(router->addr, orig_node->orig))
639                                 goto next;
640
641                         if (router->if_incoming->if_status != IF_ACTIVE)
642                                 goto next;
643
644                         if (router->tq_avg < 1)
645                                 goto next;
646
647                         /* fill one entry into buffer. */
648                         entry = (struct vis_info_entry *)
649                                       skb_put(info->skb_packet, sizeof(*entry));
650                         memcpy(entry->src,
651                                router->if_incoming->net_dev->dev_addr,
652                                ETH_ALEN);
653                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
654                         entry->quality = router->tq_avg;
655                         packet->entries++;
656
657 next:
658                         neigh_node_free_ref(router);
659
660                         if (vis_packet_full(info))
661                                 goto unlock;
662                 }
663                 rcu_read_unlock();
664         }
665
666         hash = bat_priv->tt_local_hash;
667
668         for (i = 0; i < hash->size; i++) {
669                 head = &hash->table[i];
670
671                 rcu_read_lock();
672                 hlist_for_each_entry_rcu(tt_local_entry, node, head,
673                                          hash_entry) {
674                         entry = (struct vis_info_entry *)
675                                         skb_put(info->skb_packet,
676                                                 sizeof(*entry));
677                         memset(entry->src, 0, ETH_ALEN);
678                         memcpy(entry->dest, tt_local_entry->addr, ETH_ALEN);
679                         entry->quality = 0; /* 0 means TT */
680                         packet->entries++;
681
682                         if (vis_packet_full(info))
683                                 goto unlock;
684                 }
685                 rcu_read_unlock();
686         }
687
688         return 0;
689
690 unlock:
691         rcu_read_unlock();
692         return 0;
693 }
694
695 /* free old vis packets. Must be called with this vis_hash_lock
696  * held */
697 static void purge_vis_packets(struct bat_priv *bat_priv)
698 {
699         int i;
700         struct hashtable_t *hash = bat_priv->vis_hash;
701         struct hlist_node *node, *node_tmp;
702         struct hlist_head *head;
703         struct vis_info *info;
704
705         for (i = 0; i < hash->size; i++) {
706                 head = &hash->table[i];
707
708                 hlist_for_each_entry_safe(info, node, node_tmp,
709                                           head, hash_entry) {
710                         /* never purge own data. */
711                         if (info == bat_priv->my_vis_info)
712                                 continue;
713
714                         if (time_after(jiffies,
715                                        info->first_seen + VIS_TIMEOUT * HZ)) {
716                                 hlist_del(node);
717                                 send_list_del(info);
718                                 kref_put(&info->refcount, free_info);
719                         }
720                 }
721         }
722 }
723
724 static void broadcast_vis_packet(struct bat_priv *bat_priv,
725                                  struct vis_info *info)
726 {
727         struct neigh_node *router;
728         struct hashtable_t *hash = bat_priv->orig_hash;
729         struct hlist_node *node;
730         struct hlist_head *head;
731         struct orig_node *orig_node;
732         struct vis_packet *packet;
733         struct sk_buff *skb;
734         struct hard_iface *hard_iface;
735         uint8_t dstaddr[ETH_ALEN];
736         int i;
737
738
739         packet = (struct vis_packet *)info->skb_packet->data;
740
741         /* send to all routers in range. */
742         for (i = 0; i < hash->size; i++) {
743                 head = &hash->table[i];
744
745                 rcu_read_lock();
746                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
747                         /* if it's a vis server and reachable, send it. */
748                         if (!(orig_node->flags & VIS_SERVER))
749                                 continue;
750
751                         router = orig_node_get_router(orig_node);
752                         if (!router)
753                                 continue;
754
755                         /* don't send it if we already received the packet from
756                          * this node. */
757                         if (recv_list_is_in(bat_priv, &info->recv_list,
758                                             orig_node->orig)) {
759                                 neigh_node_free_ref(router);
760                                 continue;
761                         }
762
763                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
764                         hard_iface = router->if_incoming;
765                         memcpy(dstaddr, router->addr, ETH_ALEN);
766
767                         neigh_node_free_ref(router);
768
769                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
770                         if (skb)
771                                 send_skb_packet(skb, hard_iface, dstaddr);
772
773                 }
774                 rcu_read_unlock();
775         }
776 }
777
778 static void unicast_vis_packet(struct bat_priv *bat_priv,
779                                struct vis_info *info)
780 {
781         struct orig_node *orig_node;
782         struct neigh_node *router = NULL;
783         struct sk_buff *skb;
784         struct vis_packet *packet;
785
786         packet = (struct vis_packet *)info->skb_packet->data;
787
788         orig_node = orig_hash_find(bat_priv, packet->target_orig);
789         if (!orig_node)
790                 goto out;
791
792         router = orig_node_get_router(orig_node);
793         if (!router)
794                 goto out;
795
796         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
797         if (skb)
798                 send_skb_packet(skb, router->if_incoming, router->addr);
799
800 out:
801         if (router)
802                 neigh_node_free_ref(router);
803         if (orig_node)
804                 orig_node_free_ref(orig_node);
805 }
806
807 /* only send one vis packet. called from send_vis_packets() */
808 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
809 {
810         struct hard_iface *primary_if;
811         struct vis_packet *packet;
812
813         primary_if = primary_if_get_selected(bat_priv);
814         if (!primary_if)
815                 goto out;
816
817         packet = (struct vis_packet *)info->skb_packet->data;
818         if (packet->ttl < 2) {
819                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
820                 goto out;
821         }
822
823         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
824         packet->ttl--;
825
826         if (is_broadcast_ether_addr(packet->target_orig))
827                 broadcast_vis_packet(bat_priv, info);
828         else
829                 unicast_vis_packet(bat_priv, info);
830         packet->ttl++; /* restore TTL */
831
832 out:
833         if (primary_if)
834                 hardif_free_ref(primary_if);
835 }
836
837 /* called from timer; send (and maybe generate) vis packet. */
838 static void send_vis_packets(struct work_struct *work)
839 {
840         struct delayed_work *delayed_work =
841                 container_of(work, struct delayed_work, work);
842         struct bat_priv *bat_priv =
843                 container_of(delayed_work, struct bat_priv, vis_work);
844         struct vis_info *info;
845
846         spin_lock_bh(&bat_priv->vis_hash_lock);
847         purge_vis_packets(bat_priv);
848
849         if (generate_vis_packet(bat_priv) == 0) {
850                 /* schedule if generation was successful */
851                 send_list_add(bat_priv, bat_priv->my_vis_info);
852         }
853
854         while (!list_empty(&bat_priv->vis_send_list)) {
855                 info = list_first_entry(&bat_priv->vis_send_list,
856                                         typeof(*info), send_list);
857
858                 kref_get(&info->refcount);
859                 spin_unlock_bh(&bat_priv->vis_hash_lock);
860
861                 send_vis_packet(bat_priv, info);
862
863                 spin_lock_bh(&bat_priv->vis_hash_lock);
864                 send_list_del(info);
865                 kref_put(&info->refcount, free_info);
866         }
867         spin_unlock_bh(&bat_priv->vis_hash_lock);
868         start_vis_timer(bat_priv);
869 }
870
871 /* init the vis server. this may only be called when if_list is already
872  * initialized (e.g. bat0 is initialized, interfaces have been added) */
873 int vis_init(struct bat_priv *bat_priv)
874 {
875         struct vis_packet *packet;
876         int hash_added;
877
878         if (bat_priv->vis_hash)
879                 return 1;
880
881         spin_lock_bh(&bat_priv->vis_hash_lock);
882
883         bat_priv->vis_hash = hash_new(256);
884         if (!bat_priv->vis_hash) {
885                 pr_err("Can't initialize vis_hash\n");
886                 goto err;
887         }
888
889         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
890         if (!bat_priv->my_vis_info) {
891                 pr_err("Can't initialize vis packet\n");
892                 goto err;
893         }
894
895         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
896                                                           MAX_VIS_PACKET_SIZE +
897                                                          sizeof(struct ethhdr));
898         if (!bat_priv->my_vis_info->skb_packet)
899                 goto free_info;
900
901         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
902         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
903                                               sizeof(*packet));
904
905         /* prefill the vis info */
906         bat_priv->my_vis_info->first_seen = jiffies -
907                                                 msecs_to_jiffies(VIS_INTERVAL);
908         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
909         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
910         kref_init(&bat_priv->my_vis_info->refcount);
911         bat_priv->my_vis_info->bat_priv = bat_priv;
912         packet->version = COMPAT_VERSION;
913         packet->packet_type = BAT_VIS;
914         packet->ttl = TTL;
915         packet->seqno = 0;
916         packet->entries = 0;
917
918         INIT_LIST_HEAD(&bat_priv->vis_send_list);
919
920         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
921                               bat_priv->my_vis_info,
922                               &bat_priv->my_vis_info->hash_entry);
923         if (hash_added < 0) {
924                 pr_err("Can't add own vis packet into hash\n");
925                 /* not in hash, need to remove it manually. */
926                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
927                 goto err;
928         }
929
930         spin_unlock_bh(&bat_priv->vis_hash_lock);
931         start_vis_timer(bat_priv);
932         return 1;
933
934 free_info:
935         kfree(bat_priv->my_vis_info);
936         bat_priv->my_vis_info = NULL;
937 err:
938         spin_unlock_bh(&bat_priv->vis_hash_lock);
939         vis_quit(bat_priv);
940         return 0;
941 }
942
943 /* Decrease the reference count on a hash item info */
944 static void free_info_ref(struct hlist_node *node, void *arg)
945 {
946         struct vis_info *info;
947
948         info = container_of(node, struct vis_info, hash_entry);
949         send_list_del(info);
950         kref_put(&info->refcount, free_info);
951 }
952
953 /* shutdown vis-server */
954 void vis_quit(struct bat_priv *bat_priv)
955 {
956         if (!bat_priv->vis_hash)
957                 return;
958
959         cancel_delayed_work_sync(&bat_priv->vis_work);
960
961         spin_lock_bh(&bat_priv->vis_hash_lock);
962         /* properly remove, kill timers ... */
963         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
964         bat_priv->vis_hash = NULL;
965         bat_priv->my_vis_info = NULL;
966         spin_unlock_bh(&bat_priv->vis_hash_lock);
967 }
968
969 /* schedule packets for (re)transmission */
970 static void start_vis_timer(struct bat_priv *bat_priv)
971 {
972         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
973         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
974                            msecs_to_jiffies(VIS_INTERVAL));
975 }