f90212f420828f9b59ad8924b021ef23644da66b
[linux-3.10.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 /* 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(struct hlist_node *node, void *data2)
72 {
73         struct vis_info *d1, *d2;
74         struct vis_packet *p1, *p2;
75
76         d1 = container_of(node, struct vis_info, hash_entry);
77         d2 = data2;
78         p1 = (struct vis_packet *)d1->skb_packet->data;
79         p2 = (struct vis_packet *)d2->skb_packet->data;
80         return compare_eth(p1->vis_orig, p2->vis_orig);
81 }
82
83 /* hash function to choose an entry in a hash table of given size */
84 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
85 static int vis_info_choose(void *data, int size)
86 {
87         struct vis_info *vis_info = data;
88         struct vis_packet *packet;
89         unsigned char *key;
90         uint32_t hash = 0;
91         size_t i;
92
93         packet = (struct vis_packet *)vis_info->skb_packet->data;
94         key = packet->vis_orig;
95         for (i = 0; i < ETH_ALEN; i++) {
96                 hash += key[i];
97                 hash += (hash << 10);
98                 hash ^= (hash >> 6);
99         }
100
101         hash += (hash << 3);
102         hash ^= (hash >> 11);
103         hash += (hash << 15);
104
105         return hash % size;
106 }
107
108 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
109                                       void *data)
110 {
111         struct hashtable_t *hash = bat_priv->vis_hash;
112         struct hlist_head *head;
113         struct hlist_node *node;
114         struct vis_info *vis_info, *vis_info_tmp = NULL;
115         int index;
116
117         if (!hash)
118                 return NULL;
119
120         index = vis_info_choose(data, hash->size);
121         head = &hash->table[index];
122
123         rcu_read_lock();
124         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
125                 if (!vis_info_cmp(node, data))
126                         continue;
127
128                 vis_info_tmp = vis_info;
129                 break;
130         }
131         rcu_read_unlock();
132
133         return vis_info_tmp;
134 }
135
136 /* insert interface to the list of interfaces of one originator, if it
137  * does not already exist in the list */
138 static void vis_data_insert_interface(const uint8_t *interface,
139                                       struct hlist_head *if_list,
140                                       bool primary)
141 {
142         struct if_list_entry *entry;
143         struct hlist_node *pos;
144
145         hlist_for_each_entry(entry, pos, if_list, list) {
146                 if (compare_eth(entry->addr, (void *)interface))
147                         return;
148         }
149
150         /* its a new address, add it to the list */
151         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
152         if (!entry)
153                 return;
154         memcpy(entry->addr, interface, ETH_ALEN);
155         entry->primary = primary;
156         hlist_add_head(&entry->list, if_list);
157 }
158
159 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
160 {
161         struct if_list_entry *entry;
162         struct hlist_node *pos;
163         size_t len = 0;
164
165         hlist_for_each_entry(entry, pos, if_list, list) {
166                 if (entry->primary)
167                         len += sprintf(buff + len, "PRIMARY, ");
168                 else
169                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
170         }
171
172         return len;
173 }
174
175 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
176 {
177         struct if_list_entry *entry;
178         struct hlist_node *pos;
179         size_t count = 0;
180
181         hlist_for_each_entry(entry, pos, if_list, list) {
182                 if (entry->primary)
183                         count += 9;
184                 else
185                         count += 23;
186         }
187
188         return count;
189 }
190
191 /* read an entry  */
192 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
193                                    uint8_t *src, bool primary)
194 {
195         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
196         if (primary && entry->quality == 0)
197                 return sprintf(buff, "HNA %pM, ", entry->dest);
198         else if (compare_eth(entry->src, src))
199                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
200                                entry->quality);
201
202         return 0;
203 }
204
205 int vis_seq_print_text(struct seq_file *seq, void *offset)
206 {
207         struct hlist_node *node;
208         struct hlist_head *head;
209         struct vis_info *info;
210         struct vis_packet *packet;
211         struct vis_info_entry *entries;
212         struct net_device *net_dev = (struct net_device *)seq->private;
213         struct bat_priv *bat_priv = netdev_priv(net_dev);
214         struct hashtable_t *hash = bat_priv->vis_hash;
215         HLIST_HEAD(vis_if_list);
216         struct if_list_entry *entry;
217         struct hlist_node *pos, *n;
218         int i, j;
219         int vis_server = atomic_read(&bat_priv->vis_mode);
220         size_t buff_pos, buf_size;
221         char *buff;
222         int compare;
223
224         if ((!bat_priv->primary_if) ||
225             (vis_server == VIS_TYPE_CLIENT_UPDATE))
226                 return 0;
227
228         buf_size = 1;
229         /* Estimate length */
230         spin_lock_bh(&bat_priv->vis_hash_lock);
231         for (i = 0; i < hash->size; i++) {
232                 head = &hash->table[i];
233
234                 rcu_read_lock();
235                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
236                         packet = (struct vis_packet *)info->skb_packet->data;
237                         entries = (struct vis_info_entry *)
238                                 ((char *)packet + sizeof(struct vis_packet));
239
240                         for (j = 0; j < packet->entries; j++) {
241                                 if (entries[j].quality == 0)
242                                         continue;
243                                 compare =
244                                  compare_eth(entries[j].src, packet->vis_orig);
245                                 vis_data_insert_interface(entries[j].src,
246                                                           &vis_if_list,
247                                                           compare);
248                         }
249
250                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
251                                 buf_size += 18 + 26 * packet->entries;
252
253                                 /* add primary/secondary records */
254                                 if (compare_eth(entry->addr, packet->vis_orig))
255                                         buf_size +=
256                                           vis_data_count_prim_sec(&vis_if_list);
257
258                                 buf_size += 1;
259                         }
260
261                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
262                                                   list) {
263                                 hlist_del(&entry->list);
264                                 kfree(entry);
265                         }
266                 }
267                 rcu_read_unlock();
268         }
269
270         buff = kmalloc(buf_size, GFP_ATOMIC);
271         if (!buff) {
272                 spin_unlock_bh(&bat_priv->vis_hash_lock);
273                 return -ENOMEM;
274         }
275         buff[0] = '\0';
276         buff_pos = 0;
277
278         for (i = 0; i < hash->size; i++) {
279                 head = &hash->table[i];
280
281                 rcu_read_lock();
282                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
283                         packet = (struct vis_packet *)info->skb_packet->data;
284                         entries = (struct vis_info_entry *)
285                                 ((char *)packet + sizeof(struct vis_packet));
286
287                         for (j = 0; j < packet->entries; j++) {
288                                 if (entries[j].quality == 0)
289                                         continue;
290                                 compare =
291                                  compare_eth(entries[j].src, packet->vis_orig);
292                                 vis_data_insert_interface(entries[j].src,
293                                                           &vis_if_list,
294                                                           compare);
295                         }
296
297                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
298                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
299                                                 entry->addr);
300
301                                 for (j = 0; j < packet->entries; j++)
302                                         buff_pos += vis_data_read_entry(
303                                                         buff + buff_pos,
304                                                         &entries[j],
305                                                         entry->addr,
306                                                         entry->primary);
307
308                                 /* add primary/secondary records */
309                                 if (compare_eth(entry->addr, packet->vis_orig))
310                                         buff_pos +=
311                                          vis_data_read_prim_sec(buff + buff_pos,
312                                                                 &vis_if_list);
313
314                                 buff_pos += sprintf(buff + buff_pos, "\n");
315                         }
316
317                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
318                                                   list) {
319                                 hlist_del(&entry->list);
320                                 kfree(entry);
321                         }
322                 }
323                 rcu_read_unlock();
324         }
325
326         spin_unlock_bh(&bat_priv->vis_hash_lock);
327
328         seq_printf(seq, "%s", buff);
329         kfree(buff);
330
331         return 0;
332 }
333
334 /* add the info packet to the send list, if it was not
335  * already linked in. */
336 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
337 {
338         if (list_empty(&info->send_list)) {
339                 kref_get(&info->refcount);
340                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
341         }
342 }
343
344 /* delete the info packet from the send list, if it was
345  * linked in. */
346 static void send_list_del(struct vis_info *info)
347 {
348         if (!list_empty(&info->send_list)) {
349                 list_del_init(&info->send_list);
350                 kref_put(&info->refcount, free_info);
351         }
352 }
353
354 /* tries to add one entry to the receive list. */
355 static void recv_list_add(struct bat_priv *bat_priv,
356                           struct list_head *recv_list, char *mac)
357 {
358         struct recvlist_node *entry;
359
360         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
361         if (!entry)
362                 return;
363
364         memcpy(entry->mac, mac, ETH_ALEN);
365         spin_lock_bh(&bat_priv->vis_list_lock);
366         list_add_tail(&entry->list, recv_list);
367         spin_unlock_bh(&bat_priv->vis_list_lock);
368 }
369
370 /* returns 1 if this mac is in the recv_list */
371 static int recv_list_is_in(struct bat_priv *bat_priv,
372                            struct list_head *recv_list, char *mac)
373 {
374         struct recvlist_node *entry;
375
376         spin_lock_bh(&bat_priv->vis_list_lock);
377         list_for_each_entry(entry, recv_list, list) {
378                 if (compare_eth(entry->mac, mac)) {
379                         spin_unlock_bh(&bat_priv->vis_list_lock);
380                         return 1;
381                 }
382         }
383         spin_unlock_bh(&bat_priv->vis_list_lock);
384         return 0;
385 }
386
387 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
388  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
389  * is newer than old entries in the hash. */
390 static struct vis_info *add_packet(struct bat_priv *bat_priv,
391                                    struct vis_packet *vis_packet,
392                                    int vis_info_len, int *is_new,
393                                    int make_broadcast)
394 {
395         struct vis_info *info, *old_info;
396         struct vis_packet *search_packet, *old_packet;
397         struct vis_info search_elem;
398         struct vis_packet *packet;
399         int hash_added;
400
401         *is_new = 0;
402         /* sanity check */
403         if (!bat_priv->vis_hash)
404                 return NULL;
405
406         /* see if the packet is already in vis_hash */
407         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
408         if (!search_elem.skb_packet)
409                 return NULL;
410         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
411                                                      sizeof(struct vis_packet));
412
413         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
414         old_info = vis_hash_find(bat_priv, &search_elem);
415         kfree_skb(search_elem.skb_packet);
416
417         if (old_info) {
418                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
419                 if (!seq_after(ntohl(vis_packet->seqno),
420                                ntohl(old_packet->seqno))) {
421                         if (old_packet->seqno == vis_packet->seqno) {
422                                 recv_list_add(bat_priv, &old_info->recv_list,
423                                               vis_packet->sender_orig);
424                                 return old_info;
425                         } else {
426                                 /* newer packet is already in hash. */
427                                 return NULL;
428                         }
429                 }
430                 /* remove old entry */
431                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
432                             old_info);
433                 send_list_del(old_info);
434                 kref_put(&old_info->refcount, free_info);
435         }
436
437         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
438         if (!info)
439                 return NULL;
440
441         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
442                                          vis_info_len + sizeof(struct ethhdr));
443         if (!info->skb_packet) {
444                 kfree(info);
445                 return NULL;
446         }
447         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
448         packet = (struct vis_packet *)skb_put(info->skb_packet,
449                                               sizeof(struct vis_packet) +
450                                               vis_info_len);
451
452         kref_init(&info->refcount);
453         INIT_LIST_HEAD(&info->send_list);
454         INIT_LIST_HEAD(&info->recv_list);
455         info->first_seen = jiffies;
456         info->bat_priv = bat_priv;
457         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
458
459         /* initialize and add new packet. */
460         *is_new = 1;
461
462         /* Make it a broadcast packet, if required */
463         if (make_broadcast)
464                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
465
466         /* repair if entries is longer than packet. */
467         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
468                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
469
470         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
471
472         /* try to add it */
473         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
474                               info, &info->hash_entry);
475         if (hash_added < 0) {
476                 /* did not work (for some reason) */
477                 kref_put(&info->refcount, free_info);
478                 info = NULL;
479         }
480
481         return info;
482 }
483
484 /* handle the server sync packet, forward if needed. */
485 void receive_server_sync_packet(struct bat_priv *bat_priv,
486                                 struct vis_packet *vis_packet,
487                                 int vis_info_len)
488 {
489         struct vis_info *info;
490         int is_new, make_broadcast;
491         int vis_server = atomic_read(&bat_priv->vis_mode);
492
493         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
494
495         spin_lock_bh(&bat_priv->vis_hash_lock);
496         info = add_packet(bat_priv, vis_packet, vis_info_len,
497                           &is_new, make_broadcast);
498         if (!info)
499                 goto end;
500
501         /* only if we are server ourselves and packet is newer than the one in
502          * hash.*/
503         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
504                 send_list_add(bat_priv, info);
505 end:
506         spin_unlock_bh(&bat_priv->vis_hash_lock);
507 }
508
509 /* handle an incoming client update packet and schedule forward if needed. */
510 void receive_client_update_packet(struct bat_priv *bat_priv,
511                                   struct vis_packet *vis_packet,
512                                   int vis_info_len)
513 {
514         struct vis_info *info;
515         struct vis_packet *packet;
516         int is_new;
517         int vis_server = atomic_read(&bat_priv->vis_mode);
518         int are_target = 0;
519
520         /* clients shall not broadcast. */
521         if (is_broadcast_ether_addr(vis_packet->target_orig))
522                 return;
523
524         /* Are we the target for this VIS packet? */
525         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
526             is_my_mac(vis_packet->target_orig))
527                 are_target = 1;
528
529         spin_lock_bh(&bat_priv->vis_hash_lock);
530         info = add_packet(bat_priv, vis_packet, vis_info_len,
531                           &is_new, are_target);
532
533         if (!info)
534                 goto end;
535         /* note that outdated packets will be dropped at this point. */
536
537         packet = (struct vis_packet *)info->skb_packet->data;
538
539         /* send only if we're the target server or ... */
540         if (are_target && is_new) {
541                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
542                 send_list_add(bat_priv, info);
543
544                 /* ... we're not the recipient (and thus need to forward). */
545         } else if (!is_my_mac(packet->target_orig)) {
546                 send_list_add(bat_priv, info);
547         }
548
549 end:
550         spin_unlock_bh(&bat_priv->vis_hash_lock);
551 }
552
553 /* Walk the originators and find the VIS server with the best tq. Set the packet
554  * address to its address and return the best_tq.
555  *
556  * Must be called with the originator hash locked */
557 static int find_best_vis_server(struct bat_priv *bat_priv,
558                                 struct vis_info *info)
559 {
560         struct hashtable_t *hash = bat_priv->orig_hash;
561         struct hlist_node *node;
562         struct hlist_head *head;
563         struct orig_node *orig_node;
564         struct vis_packet *packet;
565         int best_tq = -1, i;
566
567         packet = (struct vis_packet *)info->skb_packet->data;
568
569         for (i = 0; i < hash->size; i++) {
570                 head = &hash->table[i];
571
572                 rcu_read_lock();
573                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
574                         if ((orig_node) && (orig_node->router) &&
575                             (orig_node->flags & VIS_SERVER) &&
576                             (orig_node->router->tq_avg > best_tq)) {
577                                 best_tq = orig_node->router->tq_avg;
578                                 memcpy(packet->target_orig, orig_node->orig,
579                                        ETH_ALEN);
580                         }
581                 }
582                 rcu_read_unlock();
583         }
584
585         return best_tq;
586 }
587
588 /* Return true if the vis packet is full. */
589 static bool vis_packet_full(struct vis_info *info)
590 {
591         struct vis_packet *packet;
592         packet = (struct vis_packet *)info->skb_packet->data;
593
594         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
595                 < packet->entries + 1)
596                 return true;
597         return false;
598 }
599
600 /* generates a packet of own vis data,
601  * returns 0 on success, -1 if no packet could be generated */
602 static int generate_vis_packet(struct bat_priv *bat_priv)
603 {
604         struct hashtable_t *hash = bat_priv->orig_hash;
605         struct hlist_node *node;
606         struct hlist_head *head;
607         struct orig_node *orig_node;
608         struct neigh_node *neigh_node;
609         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
610         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
611         struct vis_info_entry *entry;
612         struct hna_local_entry *hna_local_entry;
613         int best_tq = -1, i;
614
615         info->first_seen = jiffies;
616         packet->vis_type = atomic_read(&bat_priv->vis_mode);
617
618         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
619         packet->ttl = TTL;
620         packet->seqno = htonl(ntohl(packet->seqno) + 1);
621         packet->entries = 0;
622         skb_trim(info->skb_packet, sizeof(struct vis_packet));
623
624         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
625                 best_tq = find_best_vis_server(bat_priv, info);
626
627                 if (best_tq < 0)
628                         return -1;
629         }
630
631         for (i = 0; i < hash->size; i++) {
632                 head = &hash->table[i];
633
634                 rcu_read_lock();
635                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
636                         neigh_node = orig_node->router;
637
638                         if (!neigh_node)
639                                 continue;
640
641                         if (!compare_eth(neigh_node->addr, orig_node->orig))
642                                 continue;
643
644                         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
645                                 continue;
646
647                         if (neigh_node->tq_avg < 1)
648                                 continue;
649
650                         /* fill one entry into buffer. */
651                         entry = (struct vis_info_entry *)
652                                       skb_put(info->skb_packet, sizeof(*entry));
653                         memcpy(entry->src,
654                                neigh_node->if_incoming->net_dev->dev_addr,
655                                ETH_ALEN);
656                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
657                         entry->quality = neigh_node->tq_avg;
658                         packet->entries++;
659
660                         if (vis_packet_full(info))
661                                 goto unlock;
662                 }
663                 rcu_read_unlock();
664         }
665
666         hash = bat_priv->hna_local_hash;
667
668         spin_lock_bh(&bat_priv->hna_lhash_lock);
669         for (i = 0; i < hash->size; i++) {
670                 head = &hash->table[i];
671
672                 hlist_for_each_entry(hna_local_entry, node, head, hash_entry) {
673                         entry = (struct vis_info_entry *)
674                                         skb_put(info->skb_packet,
675                                                 sizeof(*entry));
676                         memset(entry->src, 0, ETH_ALEN);
677                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
678                         entry->quality = 0; /* 0 means HNA */
679                         packet->entries++;
680
681                         if (vis_packet_full(info)) {
682                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
683                                 return 0;
684                         }
685                 }
686         }
687
688         spin_unlock_bh(&bat_priv->hna_lhash_lock);
689         return 0;
690
691 unlock:
692         rcu_read_unlock();
693         return 0;
694 }
695
696 /* free old vis packets. Must be called with this vis_hash_lock
697  * held */
698 static void purge_vis_packets(struct bat_priv *bat_priv)
699 {
700         int i;
701         struct hashtable_t *hash = bat_priv->vis_hash;
702         struct hlist_node *node, *node_tmp;
703         struct hlist_head *head;
704         struct vis_info *info;
705
706         for (i = 0; i < hash->size; i++) {
707                 head = &hash->table[i];
708
709                 hlist_for_each_entry_safe(info, node, node_tmp,
710                                           head, hash_entry) {
711                         /* never purge own data. */
712                         if (info == bat_priv->my_vis_info)
713                                 continue;
714
715                         if (time_after(jiffies,
716                                        info->first_seen + VIS_TIMEOUT * HZ)) {
717                                 hlist_del(node);
718                                 send_list_del(info);
719                                 kref_put(&info->refcount, free_info);
720                         }
721                 }
722         }
723 }
724
725 static void broadcast_vis_packet(struct bat_priv *bat_priv,
726                                  struct vis_info *info)
727 {
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) || (!orig_node->router))
749                                 continue;
750                         if (!(orig_node->flags & VIS_SERVER))
751                                 continue;
752                         /* don't send it if we already received the packet from
753                         * this node. */
754                         if (recv_list_is_in(bat_priv, &info->recv_list,
755                                             orig_node->orig))
756                                 continue;
757
758                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
759                         hard_iface = orig_node->router->if_incoming;
760                         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
761
762                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
763                         if (skb)
764                                 send_skb_packet(skb, hard_iface, dstaddr);
765
766                 }
767                 rcu_read_unlock();
768         }
769 }
770
771 static void unicast_vis_packet(struct bat_priv *bat_priv,
772                                struct vis_info *info)
773 {
774         struct orig_node *orig_node;
775         struct neigh_node *neigh_node = NULL;
776         struct sk_buff *skb;
777         struct vis_packet *packet;
778
779         packet = (struct vis_packet *)info->skb_packet->data;
780
781         rcu_read_lock();
782         orig_node = orig_hash_find(bat_priv, packet->target_orig);
783
784         if (!orig_node)
785                 goto unlock;
786
787         neigh_node = orig_node->router;
788
789         if (!neigh_node)
790                 goto unlock;
791
792         if (!atomic_inc_not_zero(&neigh_node->refcount)) {
793                 neigh_node = NULL;
794                 goto unlock;
795         }
796
797         rcu_read_unlock();
798
799         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
800         if (skb)
801                 send_skb_packet(skb, neigh_node->if_incoming,
802                                 neigh_node->addr);
803
804         goto out;
805
806 unlock:
807         rcu_read_unlock();
808 out:
809         if (neigh_node)
810                 neigh_node_free_ref(neigh_node);
811         if (orig_node)
812                 orig_node_free_ref(orig_node);
813         return;
814 }
815
816 /* only send one vis packet. called from send_vis_packets() */
817 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
818 {
819         struct vis_packet *packet;
820
821         packet = (struct vis_packet *)info->skb_packet->data;
822         if (packet->ttl < 2) {
823                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
824                 return;
825         }
826
827         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
828                ETH_ALEN);
829         packet->ttl--;
830
831         if (is_broadcast_ether_addr(packet->target_orig))
832                 broadcast_vis_packet(bat_priv, info);
833         else
834                 unicast_vis_packet(bat_priv, info);
835         packet->ttl++; /* restore TTL */
836 }
837
838 /* called from timer; send (and maybe generate) vis packet. */
839 static void send_vis_packets(struct work_struct *work)
840 {
841         struct delayed_work *delayed_work =
842                 container_of(work, struct delayed_work, work);
843         struct bat_priv *bat_priv =
844                 container_of(delayed_work, struct bat_priv, vis_work);
845         struct vis_info *info;
846
847         spin_lock_bh(&bat_priv->vis_hash_lock);
848         purge_vis_packets(bat_priv);
849
850         if (generate_vis_packet(bat_priv) == 0) {
851                 /* schedule if generation was successful */
852                 send_list_add(bat_priv, bat_priv->my_vis_info);
853         }
854
855         while (!list_empty(&bat_priv->vis_send_list)) {
856                 info = list_first_entry(&bat_priv->vis_send_list,
857                                         typeof(*info), send_list);
858
859                 kref_get(&info->refcount);
860                 spin_unlock_bh(&bat_priv->vis_hash_lock);
861
862                 if (bat_priv->primary_if)
863                         send_vis_packet(bat_priv, info);
864
865                 spin_lock_bh(&bat_priv->vis_hash_lock);
866                 send_list_del(info);
867                 kref_put(&info->refcount, free_info);
868         }
869         spin_unlock_bh(&bat_priv->vis_hash_lock);
870         start_vis_timer(bat_priv);
871 }
872
873 /* init the vis server. this may only be called when if_list is already
874  * initialized (e.g. bat0 is initialized, interfaces have been added) */
875 int vis_init(struct bat_priv *bat_priv)
876 {
877         struct vis_packet *packet;
878         int hash_added;
879
880         if (bat_priv->vis_hash)
881                 return 1;
882
883         spin_lock_bh(&bat_priv->vis_hash_lock);
884
885         bat_priv->vis_hash = hash_new(256);
886         if (!bat_priv->vis_hash) {
887                 pr_err("Can't initialize vis_hash\n");
888                 goto err;
889         }
890
891         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
892         if (!bat_priv->my_vis_info) {
893                 pr_err("Can't initialize vis packet\n");
894                 goto err;
895         }
896
897         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
898                                                 sizeof(struct vis_packet) +
899                                                 MAX_VIS_PACKET_SIZE +
900                                                 sizeof(struct ethhdr));
901         if (!bat_priv->my_vis_info->skb_packet)
902                 goto free_info;
903
904         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
905         packet = (struct vis_packet *)skb_put(
906                                         bat_priv->my_vis_info->skb_packet,
907                                         sizeof(struct vis_packet));
908
909         /* prefill the vis info */
910         bat_priv->my_vis_info->first_seen = jiffies -
911                                                 msecs_to_jiffies(VIS_INTERVAL);
912         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
913         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
914         kref_init(&bat_priv->my_vis_info->refcount);
915         bat_priv->my_vis_info->bat_priv = bat_priv;
916         packet->version = COMPAT_VERSION;
917         packet->packet_type = BAT_VIS;
918         packet->ttl = TTL;
919         packet->seqno = 0;
920         packet->entries = 0;
921
922         INIT_LIST_HEAD(&bat_priv->vis_send_list);
923
924         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
925                               bat_priv->my_vis_info,
926                               &bat_priv->my_vis_info->hash_entry);
927         if (hash_added < 0) {
928                 pr_err("Can't add own vis packet into hash\n");
929                 /* not in hash, need to remove it manually. */
930                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
931                 goto err;
932         }
933
934         spin_unlock_bh(&bat_priv->vis_hash_lock);
935         start_vis_timer(bat_priv);
936         return 1;
937
938 free_info:
939         kfree(bat_priv->my_vis_info);
940         bat_priv->my_vis_info = NULL;
941 err:
942         spin_unlock_bh(&bat_priv->vis_hash_lock);
943         vis_quit(bat_priv);
944         return 0;
945 }
946
947 /* Decrease the reference count on a hash item info */
948 static void free_info_ref(struct hlist_node *node, void *arg)
949 {
950         struct vis_info *info;
951
952         info = container_of(node, struct vis_info, hash_entry);
953         send_list_del(info);
954         kref_put(&info->refcount, free_info);
955 }
956
957 /* shutdown vis-server */
958 void vis_quit(struct bat_priv *bat_priv)
959 {
960         if (!bat_priv->vis_hash)
961                 return;
962
963         cancel_delayed_work_sync(&bat_priv->vis_work);
964
965         spin_lock_bh(&bat_priv->vis_hash_lock);
966         /* properly remove, kill timers ... */
967         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
968         bat_priv->vis_hash = NULL;
969         bat_priv->my_vis_info = NULL;
970         spin_unlock_bh(&bat_priv->vis_hash_lock);
971 }
972
973 /* schedule packets for (re)transmission */
974 static void start_vis_timer(struct bat_priv *bat_priv)
975 {
976         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
977         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
978                            msecs_to_jiffies(VIS_INTERVAL));
979 }