ipv4: Remove flowi from struct rtable.
[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(void *data1, void *data2)
72 {
73         struct vis_info *d1, *d2;
74         struct vis_packet *p1, *p2;
75         d1 = data1;
76         d2 = data2;
77         p1 = (struct vis_packet *)d1->skb_packet->data;
78         p2 = (struct vis_packet *)d2->skb_packet->data;
79         return compare_orig(p1->vis_orig, p2->vis_orig);
80 }
81
82 /* hash function to choose an entry in a hash table of given size */
83 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
84 static int vis_info_choose(void *data, int size)
85 {
86         struct vis_info *vis_info = data;
87         struct vis_packet *packet;
88         unsigned char *key;
89         uint32_t hash = 0;
90         size_t i;
91
92         packet = (struct vis_packet *)vis_info->skb_packet->data;
93         key = packet->vis_orig;
94         for (i = 0; i < ETH_ALEN; i++) {
95                 hash += key[i];
96                 hash += (hash << 10);
97                 hash ^= (hash >> 6);
98         }
99
100         hash += (hash << 3);
101         hash ^= (hash >> 11);
102         hash += (hash << 15);
103
104         return hash % size;
105 }
106
107 /* insert interface to the list of interfaces of one originator, if it
108  * does not already exist in the list */
109 static void vis_data_insert_interface(const uint8_t *interface,
110                                       struct hlist_head *if_list,
111                                       bool primary)
112 {
113         struct if_list_entry *entry;
114         struct hlist_node *pos;
115
116         hlist_for_each_entry(entry, pos, if_list, list) {
117                 if (compare_orig(entry->addr, (void *)interface))
118                         return;
119         }
120
121         /* its a new address, add it to the list */
122         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
123         if (!entry)
124                 return;
125         memcpy(entry->addr, interface, ETH_ALEN);
126         entry->primary = primary;
127         hlist_add_head(&entry->list, if_list);
128 }
129
130 static ssize_t vis_data_read_prim_sec(char *buff, struct hlist_head *if_list)
131 {
132         struct if_list_entry *entry;
133         struct hlist_node *pos;
134         size_t len = 0;
135
136         hlist_for_each_entry(entry, pos, if_list, list) {
137                 if (entry->primary)
138                         len += sprintf(buff + len, "PRIMARY, ");
139                 else
140                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
141         }
142
143         return len;
144 }
145
146 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
147 {
148         struct if_list_entry *entry;
149         struct hlist_node *pos;
150         size_t count = 0;
151
152         hlist_for_each_entry(entry, pos, if_list, list) {
153                 if (entry->primary)
154                         count += 9;
155                 else
156                         count += 23;
157         }
158
159         return count;
160 }
161
162 /* read an entry  */
163 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
164                                    uint8_t *src, bool primary)
165 {
166         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
167         if (primary && entry->quality == 0)
168                 return sprintf(buff, "HNA %pM, ", entry->dest);
169         else if (compare_orig(entry->src, src))
170                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
171                                entry->quality);
172
173         return 0;
174 }
175
176 int vis_seq_print_text(struct seq_file *seq, void *offset)
177 {
178         struct hlist_node *walk;
179         struct hlist_head *head;
180         struct element_t *bucket;
181         struct vis_info *info;
182         struct vis_packet *packet;
183         struct vis_info_entry *entries;
184         struct net_device *net_dev = (struct net_device *)seq->private;
185         struct bat_priv *bat_priv = netdev_priv(net_dev);
186         struct hashtable_t *hash = bat_priv->vis_hash;
187         HLIST_HEAD(vis_if_list);
188         struct if_list_entry *entry;
189         struct hlist_node *pos, *n;
190         int i, j;
191         int vis_server = atomic_read(&bat_priv->vis_mode);
192         size_t buff_pos, buf_size;
193         char *buff;
194         int compare;
195
196         if ((!bat_priv->primary_if) ||
197             (vis_server == VIS_TYPE_CLIENT_UPDATE))
198                 return 0;
199
200         buf_size = 1;
201         /* Estimate length */
202         spin_lock_bh(&bat_priv->vis_hash_lock);
203         for (i = 0; i < hash->size; i++) {
204                 head = &hash->table[i];
205
206                 hlist_for_each_entry(bucket, walk, head, hlist) {
207                         info = bucket->data;
208                         packet = (struct vis_packet *)info->skb_packet->data;
209                         entries = (struct vis_info_entry *)
210                                 ((char *)packet + sizeof(struct vis_packet));
211
212                         for (j = 0; j < packet->entries; j++) {
213                                 if (entries[j].quality == 0)
214                                         continue;
215                                 compare =
216                                  compare_orig(entries[j].src, packet->vis_orig);
217                                 vis_data_insert_interface(entries[j].src,
218                                                           &vis_if_list,
219                                                           compare);
220                         }
221
222                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
223                                 buf_size += 18 + 26 * packet->entries;
224
225                                 /* add primary/secondary records */
226                                 if (compare_orig(entry->addr, packet->vis_orig))
227                                         buf_size +=
228                                           vis_data_count_prim_sec(&vis_if_list);
229
230                                 buf_size += 1;
231                         }
232
233                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
234                                                   list) {
235                                 hlist_del(&entry->list);
236                                 kfree(entry);
237                         }
238                 }
239         }
240
241         buff = kmalloc(buf_size, GFP_ATOMIC);
242         if (!buff) {
243                 spin_unlock_bh(&bat_priv->vis_hash_lock);
244                 return -ENOMEM;
245         }
246         buff[0] = '\0';
247         buff_pos = 0;
248
249         for (i = 0; i < hash->size; i++) {
250                 head = &hash->table[i];
251
252                 hlist_for_each_entry(bucket, walk, head, hlist) {
253                         info = bucket->data;
254                         packet = (struct vis_packet *)info->skb_packet->data;
255                         entries = (struct vis_info_entry *)
256                                 ((char *)packet + sizeof(struct vis_packet));
257
258                         for (j = 0; j < packet->entries; j++) {
259                                 if (entries[j].quality == 0)
260                                         continue;
261                                 compare =
262                                  compare_orig(entries[j].src, packet->vis_orig);
263                                 vis_data_insert_interface(entries[j].src,
264                                                           &vis_if_list,
265                                                           compare);
266                         }
267
268                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
269                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
270                                                 entry->addr);
271
272                                 for (j = 0; j < packet->entries; j++)
273                                         buff_pos += vis_data_read_entry(
274                                                         buff + buff_pos,
275                                                         &entries[j],
276                                                         entry->addr,
277                                                         entry->primary);
278
279                                 /* add primary/secondary records */
280                                 if (compare_orig(entry->addr, packet->vis_orig))
281                                         buff_pos +=
282                                          vis_data_read_prim_sec(buff + buff_pos,
283                                                                 &vis_if_list);
284
285                                 buff_pos += sprintf(buff + buff_pos, "\n");
286                         }
287
288                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
289                                                   list) {
290                                 hlist_del(&entry->list);
291                                 kfree(entry);
292                         }
293                 }
294         }
295
296         spin_unlock_bh(&bat_priv->vis_hash_lock);
297
298         seq_printf(seq, "%s", buff);
299         kfree(buff);
300
301         return 0;
302 }
303
304 /* add the info packet to the send list, if it was not
305  * already linked in. */
306 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
307 {
308         if (list_empty(&info->send_list)) {
309                 kref_get(&info->refcount);
310                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
311         }
312 }
313
314 /* delete the info packet from the send list, if it was
315  * linked in. */
316 static void send_list_del(struct vis_info *info)
317 {
318         if (!list_empty(&info->send_list)) {
319                 list_del_init(&info->send_list);
320                 kref_put(&info->refcount, free_info);
321         }
322 }
323
324 /* tries to add one entry to the receive list. */
325 static void recv_list_add(struct bat_priv *bat_priv,
326                           struct list_head *recv_list, char *mac)
327 {
328         struct recvlist_node *entry;
329
330         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
331         if (!entry)
332                 return;
333
334         memcpy(entry->mac, mac, ETH_ALEN);
335         spin_lock_bh(&bat_priv->vis_list_lock);
336         list_add_tail(&entry->list, recv_list);
337         spin_unlock_bh(&bat_priv->vis_list_lock);
338 }
339
340 /* returns 1 if this mac is in the recv_list */
341 static int recv_list_is_in(struct bat_priv *bat_priv,
342                            struct list_head *recv_list, char *mac)
343 {
344         struct recvlist_node *entry;
345
346         spin_lock_bh(&bat_priv->vis_list_lock);
347         list_for_each_entry(entry, recv_list, list) {
348                 if (memcmp(entry->mac, mac, ETH_ALEN) == 0) {
349                         spin_unlock_bh(&bat_priv->vis_list_lock);
350                         return 1;
351                 }
352         }
353         spin_unlock_bh(&bat_priv->vis_list_lock);
354         return 0;
355 }
356
357 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
358  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
359  * is newer than old entries in the hash. */
360 static struct vis_info *add_packet(struct bat_priv *bat_priv,
361                                    struct vis_packet *vis_packet,
362                                    int vis_info_len, int *is_new,
363                                    int make_broadcast)
364 {
365         struct vis_info *info, *old_info;
366         struct vis_packet *search_packet, *old_packet;
367         struct vis_info search_elem;
368         struct vis_packet *packet;
369         int hash_added;
370
371         *is_new = 0;
372         /* sanity check */
373         if (!bat_priv->vis_hash)
374                 return NULL;
375
376         /* see if the packet is already in vis_hash */
377         search_elem.skb_packet = dev_alloc_skb(sizeof(struct vis_packet));
378         if (!search_elem.skb_packet)
379                 return NULL;
380         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
381                                                      sizeof(struct vis_packet));
382
383         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
384         old_info = hash_find(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
385                              &search_elem);
386         kfree_skb(search_elem.skb_packet);
387
388         if (old_info) {
389                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
390                 if (!seq_after(ntohl(vis_packet->seqno),
391                                ntohl(old_packet->seqno))) {
392                         if (old_packet->seqno == vis_packet->seqno) {
393                                 recv_list_add(bat_priv, &old_info->recv_list,
394                                               vis_packet->sender_orig);
395                                 return old_info;
396                         } else {
397                                 /* newer packet is already in hash. */
398                                 return NULL;
399                         }
400                 }
401                 /* remove old entry */
402                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
403                             old_info);
404                 send_list_del(old_info);
405                 kref_put(&old_info->refcount, free_info);
406         }
407
408         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
409         if (!info)
410                 return NULL;
411
412         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
413                                          vis_info_len + sizeof(struct ethhdr));
414         if (!info->skb_packet) {
415                 kfree(info);
416                 return NULL;
417         }
418         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
419         packet = (struct vis_packet *)skb_put(info->skb_packet,
420                                               sizeof(struct vis_packet) +
421                                               vis_info_len);
422
423         kref_init(&info->refcount);
424         INIT_LIST_HEAD(&info->send_list);
425         INIT_LIST_HEAD(&info->recv_list);
426         info->first_seen = jiffies;
427         info->bat_priv = bat_priv;
428         memcpy(packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);
429
430         /* initialize and add new packet. */
431         *is_new = 1;
432
433         /* Make it a broadcast packet, if required */
434         if (make_broadcast)
435                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
436
437         /* repair if entries is longer than packet. */
438         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
439                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
440
441         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
442
443         /* try to add it */
444         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
445                               info);
446         if (hash_added < 0) {
447                 /* did not work (for some reason) */
448                 kref_put(&info->refcount, free_info);
449                 info = NULL;
450         }
451
452         return info;
453 }
454
455 /* handle the server sync packet, forward if needed. */
456 void receive_server_sync_packet(struct bat_priv *bat_priv,
457                                 struct vis_packet *vis_packet,
458                                 int vis_info_len)
459 {
460         struct vis_info *info;
461         int is_new, make_broadcast;
462         int vis_server = atomic_read(&bat_priv->vis_mode);
463
464         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
465
466         spin_lock_bh(&bat_priv->vis_hash_lock);
467         info = add_packet(bat_priv, vis_packet, vis_info_len,
468                           &is_new, make_broadcast);
469         if (!info)
470                 goto end;
471
472         /* only if we are server ourselves and packet is newer than the one in
473          * hash.*/
474         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
475                 send_list_add(bat_priv, info);
476 end:
477         spin_unlock_bh(&bat_priv->vis_hash_lock);
478 }
479
480 /* handle an incoming client update packet and schedule forward if needed. */
481 void receive_client_update_packet(struct bat_priv *bat_priv,
482                                   struct vis_packet *vis_packet,
483                                   int vis_info_len)
484 {
485         struct vis_info *info;
486         struct vis_packet *packet;
487         int is_new;
488         int vis_server = atomic_read(&bat_priv->vis_mode);
489         int are_target = 0;
490
491         /* clients shall not broadcast. */
492         if (is_broadcast_ether_addr(vis_packet->target_orig))
493                 return;
494
495         /* Are we the target for this VIS packet? */
496         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
497             is_my_mac(vis_packet->target_orig))
498                 are_target = 1;
499
500         spin_lock_bh(&bat_priv->vis_hash_lock);
501         info = add_packet(bat_priv, vis_packet, vis_info_len,
502                           &is_new, are_target);
503
504         if (!info)
505                 goto end;
506         /* note that outdated packets will be dropped at this point. */
507
508         packet = (struct vis_packet *)info->skb_packet->data;
509
510         /* send only if we're the target server or ... */
511         if (are_target && is_new) {
512                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
513                 send_list_add(bat_priv, info);
514
515                 /* ... we're not the recipient (and thus need to forward). */
516         } else if (!is_my_mac(packet->target_orig)) {
517                 send_list_add(bat_priv, info);
518         }
519
520 end:
521         spin_unlock_bh(&bat_priv->vis_hash_lock);
522 }
523
524 /* Walk the originators and find the VIS server with the best tq. Set the packet
525  * address to its address and return the best_tq.
526  *
527  * Must be called with the originator hash locked */
528 static int find_best_vis_server(struct bat_priv *bat_priv,
529                                 struct vis_info *info)
530 {
531         struct hashtable_t *hash = bat_priv->orig_hash;
532         struct hlist_node *walk;
533         struct hlist_head *head;
534         struct element_t *bucket;
535         struct orig_node *orig_node;
536         struct vis_packet *packet;
537         int best_tq = -1, i;
538
539         packet = (struct vis_packet *)info->skb_packet->data;
540
541         for (i = 0; i < hash->size; i++) {
542                 head = &hash->table[i];
543
544                 hlist_for_each_entry(bucket, walk, head, hlist) {
545                         orig_node = bucket->data;
546                         if ((orig_node) && (orig_node->router) &&
547                         (orig_node->flags & VIS_SERVER) &&
548                         (orig_node->router->tq_avg > best_tq)) {
549                                 best_tq = orig_node->router->tq_avg;
550                                 memcpy(packet->target_orig, orig_node->orig,
551                                        ETH_ALEN);
552                         }
553                 }
554         }
555
556         return best_tq;
557 }
558
559 /* Return true if the vis packet is full. */
560 static bool vis_packet_full(struct vis_info *info)
561 {
562         struct vis_packet *packet;
563         packet = (struct vis_packet *)info->skb_packet->data;
564
565         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
566                 < packet->entries + 1)
567                 return true;
568         return false;
569 }
570
571 /* generates a packet of own vis data,
572  * returns 0 on success, -1 if no packet could be generated */
573 static int generate_vis_packet(struct bat_priv *bat_priv)
574 {
575         struct hashtable_t *hash = bat_priv->orig_hash;
576         struct hlist_node *walk;
577         struct hlist_head *head;
578         struct element_t *bucket;
579         struct orig_node *orig_node;
580         struct neigh_node *neigh_node;
581         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
582         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
583         struct vis_info_entry *entry;
584         struct hna_local_entry *hna_local_entry;
585         int best_tq = -1, i;
586
587         info->first_seen = jiffies;
588         packet->vis_type = atomic_read(&bat_priv->vis_mode);
589
590         spin_lock_bh(&bat_priv->orig_hash_lock);
591         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
592         packet->ttl = TTL;
593         packet->seqno = htonl(ntohl(packet->seqno) + 1);
594         packet->entries = 0;
595         skb_trim(info->skb_packet, sizeof(struct vis_packet));
596
597         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
598                 best_tq = find_best_vis_server(bat_priv, info);
599
600                 if (best_tq < 0) {
601                         spin_unlock_bh(&bat_priv->orig_hash_lock);
602                         return -1;
603                 }
604         }
605
606         for (i = 0; i < hash->size; i++) {
607                 head = &hash->table[i];
608
609                 hlist_for_each_entry(bucket, walk, head, hlist) {
610                         orig_node = bucket->data;
611                         neigh_node = orig_node->router;
612
613                         if (!neigh_node)
614                                 continue;
615
616                         if (!compare_orig(neigh_node->addr, orig_node->orig))
617                                 continue;
618
619                         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
620                                 continue;
621
622                         if (neigh_node->tq_avg < 1)
623                                 continue;
624
625                         /* fill one entry into buffer. */
626                         entry = (struct vis_info_entry *)
627                                       skb_put(info->skb_packet, sizeof(*entry));
628                         memcpy(entry->src,
629                                neigh_node->if_incoming->net_dev->dev_addr,
630                                ETH_ALEN);
631                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
632                         entry->quality = neigh_node->tq_avg;
633                         packet->entries++;
634
635                         if (vis_packet_full(info)) {
636                                 spin_unlock_bh(&bat_priv->orig_hash_lock);
637                                 return 0;
638                         }
639                 }
640         }
641
642         spin_unlock_bh(&bat_priv->orig_hash_lock);
643
644         hash = bat_priv->hna_local_hash;
645
646         spin_lock_bh(&bat_priv->hna_lhash_lock);
647         for (i = 0; i < hash->size; i++) {
648                 head = &hash->table[i];
649
650                 hlist_for_each_entry(bucket, walk, head, hlist) {
651                         hna_local_entry = bucket->data;
652                         entry = (struct vis_info_entry *)
653                                         skb_put(info->skb_packet,
654                                                 sizeof(*entry));
655                         memset(entry->src, 0, ETH_ALEN);
656                         memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
657                         entry->quality = 0; /* 0 means HNA */
658                         packet->entries++;
659
660                         if (vis_packet_full(info)) {
661                                 spin_unlock_bh(&bat_priv->hna_lhash_lock);
662                                 return 0;
663                         }
664                 }
665         }
666
667         spin_unlock_bh(&bat_priv->hna_lhash_lock);
668         return 0;
669 }
670
671 /* free old vis packets. Must be called with this vis_hash_lock
672  * held */
673 static void purge_vis_packets(struct bat_priv *bat_priv)
674 {
675         int i;
676         struct hashtable_t *hash = bat_priv->vis_hash;
677         struct hlist_node *walk, *safe;
678         struct hlist_head *head;
679         struct element_t *bucket;
680         struct vis_info *info;
681
682         for (i = 0; i < hash->size; i++) {
683                 head = &hash->table[i];
684
685                 hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
686                         info = bucket->data;
687
688                         /* never purge own data. */
689                         if (info == bat_priv->my_vis_info)
690                                 continue;
691
692                         if (time_after(jiffies,
693                                        info->first_seen + VIS_TIMEOUT * HZ)) {
694                                 hlist_del(walk);
695                                 kfree(bucket);
696                                 send_list_del(info);
697                                 kref_put(&info->refcount, free_info);
698                         }
699                 }
700         }
701 }
702
703 static void broadcast_vis_packet(struct bat_priv *bat_priv,
704                                  struct vis_info *info)
705 {
706         struct hashtable_t *hash = bat_priv->orig_hash;
707         struct hlist_node *walk;
708         struct hlist_head *head;
709         struct element_t *bucket;
710         struct orig_node *orig_node;
711         struct vis_packet *packet;
712         struct sk_buff *skb;
713         struct batman_if *batman_if;
714         uint8_t dstaddr[ETH_ALEN];
715         int i;
716
717
718         spin_lock_bh(&bat_priv->orig_hash_lock);
719         packet = (struct vis_packet *)info->skb_packet->data;
720
721         /* send to all routers in range. */
722         for (i = 0; i < hash->size; i++) {
723                 head = &hash->table[i];
724
725                 hlist_for_each_entry(bucket, walk, head, hlist) {
726                         orig_node = bucket->data;
727
728                         /* if it's a vis server and reachable, send it. */
729                         if ((!orig_node) || (!orig_node->router))
730                                 continue;
731                         if (!(orig_node->flags & VIS_SERVER))
732                                 continue;
733                         /* don't send it if we already received the packet from
734                         * this node. */
735                         if (recv_list_is_in(bat_priv, &info->recv_list,
736                                             orig_node->orig))
737                                 continue;
738
739                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
740                         batman_if = orig_node->router->if_incoming;
741                         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
742                         spin_unlock_bh(&bat_priv->orig_hash_lock);
743
744                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
745                         if (skb)
746                                 send_skb_packet(skb, batman_if, dstaddr);
747
748                         spin_lock_bh(&bat_priv->orig_hash_lock);
749                 }
750
751         }
752
753         spin_unlock_bh(&bat_priv->orig_hash_lock);
754 }
755
756 static void unicast_vis_packet(struct bat_priv *bat_priv,
757                                struct vis_info *info)
758 {
759         struct orig_node *orig_node;
760         struct sk_buff *skb;
761         struct vis_packet *packet;
762         struct batman_if *batman_if;
763         uint8_t dstaddr[ETH_ALEN];
764
765         spin_lock_bh(&bat_priv->orig_hash_lock);
766         packet = (struct vis_packet *)info->skb_packet->data;
767         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
768                                                    compare_orig, choose_orig,
769                                                    packet->target_orig));
770
771         if ((!orig_node) || (!orig_node->router))
772                 goto out;
773
774         /* don't lock while sending the packets ... we therefore
775          * copy the required data before sending */
776         batman_if = orig_node->router->if_incoming;
777         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
778         spin_unlock_bh(&bat_priv->orig_hash_lock);
779
780         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
781         if (skb)
782                 send_skb_packet(skb, batman_if, dstaddr);
783
784         return;
785
786 out:
787         spin_unlock_bh(&bat_priv->orig_hash_lock);
788 }
789
790 /* only send one vis packet. called from send_vis_packets() */
791 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
792 {
793         struct vis_packet *packet;
794
795         packet = (struct vis_packet *)info->skb_packet->data;
796         if (packet->ttl < 2) {
797                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
798                 return;
799         }
800
801         memcpy(packet->sender_orig, bat_priv->primary_if->net_dev->dev_addr,
802                ETH_ALEN);
803         packet->ttl--;
804
805         if (is_broadcast_ether_addr(packet->target_orig))
806                 broadcast_vis_packet(bat_priv, info);
807         else
808                 unicast_vis_packet(bat_priv, info);
809         packet->ttl++; /* restore TTL */
810 }
811
812 /* called from timer; send (and maybe generate) vis packet. */
813 static void send_vis_packets(struct work_struct *work)
814 {
815         struct delayed_work *delayed_work =
816                 container_of(work, struct delayed_work, work);
817         struct bat_priv *bat_priv =
818                 container_of(delayed_work, struct bat_priv, vis_work);
819         struct vis_info *info;
820
821         spin_lock_bh(&bat_priv->vis_hash_lock);
822         purge_vis_packets(bat_priv);
823
824         if (generate_vis_packet(bat_priv) == 0) {
825                 /* schedule if generation was successful */
826                 send_list_add(bat_priv, bat_priv->my_vis_info);
827         }
828
829         while (!list_empty(&bat_priv->vis_send_list)) {
830                 info = list_first_entry(&bat_priv->vis_send_list,
831                                         typeof(*info), send_list);
832
833                 kref_get(&info->refcount);
834                 spin_unlock_bh(&bat_priv->vis_hash_lock);
835
836                 if (bat_priv->primary_if)
837                         send_vis_packet(bat_priv, info);
838
839                 spin_lock_bh(&bat_priv->vis_hash_lock);
840                 send_list_del(info);
841                 kref_put(&info->refcount, free_info);
842         }
843         spin_unlock_bh(&bat_priv->vis_hash_lock);
844         start_vis_timer(bat_priv);
845 }
846
847 /* init the vis server. this may only be called when if_list is already
848  * initialized (e.g. bat0 is initialized, interfaces have been added) */
849 int vis_init(struct bat_priv *bat_priv)
850 {
851         struct vis_packet *packet;
852         int hash_added;
853
854         if (bat_priv->vis_hash)
855                 return 1;
856
857         spin_lock_bh(&bat_priv->vis_hash_lock);
858
859         bat_priv->vis_hash = hash_new(256);
860         if (!bat_priv->vis_hash) {
861                 pr_err("Can't initialize vis_hash\n");
862                 goto err;
863         }
864
865         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
866         if (!bat_priv->my_vis_info) {
867                 pr_err("Can't initialize vis packet\n");
868                 goto err;
869         }
870
871         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
872                                                 sizeof(struct vis_packet) +
873                                                 MAX_VIS_PACKET_SIZE +
874                                                 sizeof(struct ethhdr));
875         if (!bat_priv->my_vis_info->skb_packet)
876                 goto free_info;
877
878         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
879         packet = (struct vis_packet *)skb_put(
880                                         bat_priv->my_vis_info->skb_packet,
881                                         sizeof(struct vis_packet));
882
883         /* prefill the vis info */
884         bat_priv->my_vis_info->first_seen = jiffies -
885                                                 msecs_to_jiffies(VIS_INTERVAL);
886         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
887         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
888         kref_init(&bat_priv->my_vis_info->refcount);
889         bat_priv->my_vis_info->bat_priv = bat_priv;
890         packet->version = COMPAT_VERSION;
891         packet->packet_type = BAT_VIS;
892         packet->ttl = TTL;
893         packet->seqno = 0;
894         packet->entries = 0;
895
896         INIT_LIST_HEAD(&bat_priv->vis_send_list);
897
898         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
899                               bat_priv->my_vis_info);
900         if (hash_added < 0) {
901                 pr_err("Can't add own vis packet into hash\n");
902                 /* not in hash, need to remove it manually. */
903                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
904                 goto err;
905         }
906
907         spin_unlock_bh(&bat_priv->vis_hash_lock);
908         start_vis_timer(bat_priv);
909         return 1;
910
911 free_info:
912         kfree(bat_priv->my_vis_info);
913         bat_priv->my_vis_info = NULL;
914 err:
915         spin_unlock_bh(&bat_priv->vis_hash_lock);
916         vis_quit(bat_priv);
917         return 0;
918 }
919
920 /* Decrease the reference count on a hash item info */
921 static void free_info_ref(void *data, void *arg)
922 {
923         struct vis_info *info = data;
924
925         send_list_del(info);
926         kref_put(&info->refcount, free_info);
927 }
928
929 /* shutdown vis-server */
930 void vis_quit(struct bat_priv *bat_priv)
931 {
932         if (!bat_priv->vis_hash)
933                 return;
934
935         cancel_delayed_work_sync(&bat_priv->vis_work);
936
937         spin_lock_bh(&bat_priv->vis_hash_lock);
938         /* properly remove, kill timers ... */
939         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
940         bat_priv->vis_hash = NULL;
941         bat_priv->my_vis_info = NULL;
942         spin_unlock_bh(&bat_priv->vis_hash_lock);
943 }
944
945 /* schedule packets for (re)transmission */
946 static void start_vis_timer(struct bat_priv *bat_priv)
947 {
948         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
949         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
950                            msecs_to_jiffies(VIS_INTERVAL));
951 }