blob: 511d7e1eea38b6d6e13247df0f8d4399deea8382 [file] [log] [blame]
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001/* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
2 *
3 * Martin Hundebøll, Jeppe Ledet-Pedersen
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
18 */
19
Martin Hundebølld56b1702013-01-25 11:12:39 +010020#include <linux/debugfs.h>
21
Martin Hundebølld353d8d2013-01-25 11:12:38 +010022#include "main.h"
Martin Hundebøll95332472013-01-25 11:12:40 +010023#include "hash.h"
Martin Hundebølld353d8d2013-01-25 11:12:38 +010024#include "network-coding.h"
Martin Hundebøll95332472013-01-25 11:12:40 +010025#include "send.h"
Martin Hundebølld56b1702013-01-25 11:12:39 +010026#include "originator.h"
27#include "hard-interface.h"
Martin Hundebøll2df52782013-01-25 11:12:43 +010028#include "routing.h"
Martin Hundebølld353d8d2013-01-25 11:12:38 +010029
Martin Hundebøll95332472013-01-25 11:12:40 +010030static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
Martin Hundebøll612d2b42013-01-25 11:12:42 +010031static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
Martin Hundebøll95332472013-01-25 11:12:40 +010032
Martin Hundebølld353d8d2013-01-25 11:12:38 +010033static void batadv_nc_worker(struct work_struct *work);
Martin Hundebøll2df52782013-01-25 11:12:43 +010034static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
35 struct batadv_hard_iface *recv_if);
Martin Hundebølld353d8d2013-01-25 11:12:38 +010036
37/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +020038 * batadv_nc_init - one-time initialization for network coding
39 */
40int __init batadv_nc_init(void)
41{
42 int ret;
43
44 /* Register our packet type */
45 ret = batadv_recv_handler_register(BATADV_CODED,
46 batadv_nc_recv_coded_packet);
47
48 return ret;
49}
50
51/**
Martin Hundebølld353d8d2013-01-25 11:12:38 +010052 * batadv_nc_start_timer - initialise the nc periodic worker
53 * @bat_priv: the bat priv with all the soft interface information
54 */
55static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
56{
57 queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
58 msecs_to_jiffies(10));
59}
60
61/**
Marek Lindner3f4841f2013-04-23 21:40:00 +080062 * batadv_nc_tvlv_container_update - update the network coding tvlv container
63 * after network coding setting change
64 * @bat_priv: the bat priv with all the soft interface information
65 */
66static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv)
67{
68 char nc_mode;
69
70 nc_mode = atomic_read(&bat_priv->network_coding);
71
72 switch (nc_mode) {
73 case 0:
74 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
75 break;
76 case 1:
77 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1,
78 NULL, 0);
79 break;
80 }
81}
82
83/**
84 * batadv_nc_status_update - update the network coding tvlv container after
85 * network coding setting change
86 * @net_dev: the soft interface net device
87 */
88void batadv_nc_status_update(struct net_device *net_dev)
89{
90 struct batadv_priv *bat_priv = netdev_priv(net_dev);
91 batadv_nc_tvlv_container_update(bat_priv);
92}
93
94/**
95 * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
96 * @bat_priv: the bat priv with all the soft interface information
97 * @orig: the orig_node of the ogm
98 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
99 * @tvlv_value: tvlv buffer containing the gateway data
100 * @tvlv_value_len: tvlv buffer length
101 */
102static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
103 struct batadv_orig_node *orig,
104 uint8_t flags,
105 void *tvlv_value,
106 uint16_t tvlv_value_len)
107{
108 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
109 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC;
110 else
111 orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC;
112}
113
114/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +0200115 * batadv_nc_mesh_init - initialise coding hash table and start house keeping
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100116 * @bat_priv: the bat priv with all the soft interface information
117 */
Matthias Schiffer6c519ba2013-09-27 18:03:39 +0200118int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100119{
Martin Hundebøll95332472013-01-25 11:12:40 +0100120 bat_priv->nc.timestamp_fwd_flush = jiffies;
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100121 bat_priv->nc.timestamp_sniffed_purge = jiffies;
Martin Hundebøll95332472013-01-25 11:12:40 +0100122
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100123 if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
Martin Hundebøll95332472013-01-25 11:12:40 +0100124 return 0;
125
126 bat_priv->nc.coding_hash = batadv_hash_new(128);
127 if (!bat_priv->nc.coding_hash)
128 goto err;
129
130 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
131 &batadv_nc_coding_hash_lock_class_key);
132
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100133 bat_priv->nc.decoding_hash = batadv_hash_new(128);
134 if (!bat_priv->nc.decoding_hash)
135 goto err;
136
137 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
138 &batadv_nc_decoding_hash_lock_class_key);
139
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100140 INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
141 batadv_nc_start_timer(bat_priv);
142
Marek Lindner3f4841f2013-04-23 21:40:00 +0800143 batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1,
144 NULL, BATADV_TVLV_NC, 1,
145 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
146 batadv_nc_tvlv_container_update(bat_priv);
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100147 return 0;
Martin Hundebøll95332472013-01-25 11:12:40 +0100148
149err:
150 return -ENOMEM;
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100151}
152
153/**
154 * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
155 * @bat_priv: the bat priv with all the soft interface information
156 */
157void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
158{
159 atomic_set(&bat_priv->network_coding, 1);
Martin Hundebølld56b1702013-01-25 11:12:39 +0100160 bat_priv->nc.min_tq = 200;
Martin Hundebøll95332472013-01-25 11:12:40 +0100161 bat_priv->nc.max_fwd_delay = 10;
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100162 bat_priv->nc.max_buffer_time = 200;
Martin Hundebølld56b1702013-01-25 11:12:39 +0100163}
164
165/**
166 * batadv_nc_init_orig - initialise the nc fields of an orig_node
167 * @orig_node: the orig_node which is going to be initialised
168 */
169void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
170{
171 INIT_LIST_HEAD(&orig_node->in_coding_list);
172 INIT_LIST_HEAD(&orig_node->out_coding_list);
173 spin_lock_init(&orig_node->in_coding_list_lock);
174 spin_lock_init(&orig_node->out_coding_list_lock);
175}
176
177/**
178 * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove
179 * its refcount on the orig_node
180 * @rcu: rcu pointer of the nc node
181 */
182static void batadv_nc_node_free_rcu(struct rcu_head *rcu)
183{
184 struct batadv_nc_node *nc_node;
185
186 nc_node = container_of(rcu, struct batadv_nc_node, rcu);
187 batadv_orig_node_free_ref(nc_node->orig_node);
188 kfree(nc_node);
189}
190
191/**
192 * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly
193 * frees it
194 * @nc_node: the nc node to free
195 */
196static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
197{
198 if (atomic_dec_and_test(&nc_node->refcount))
199 call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu);
200}
201
202/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100203 * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
204 * frees it
205 * @nc_path: the nc node to free
206 */
207static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path)
208{
209 if (atomic_dec_and_test(&nc_path->refcount))
210 kfree_rcu(nc_path, rcu);
211}
212
213/**
214 * batadv_nc_packet_free - frees nc packet
215 * @nc_packet: the nc packet to free
216 */
217static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet)
218{
219 if (nc_packet->skb)
220 kfree_skb(nc_packet->skb);
221
222 batadv_nc_path_free_ref(nc_packet->nc_path);
223 kfree(nc_packet);
224}
225
226/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100227 * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
228 * @bat_priv: the bat priv with all the soft interface information
229 * @nc_node: the nc node to check
230 *
231 * Returns true if the entry has to be purged now, false otherwise
232 */
233static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
234 struct batadv_nc_node *nc_node)
235{
236 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
237 return true;
238
239 return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
240}
241
242/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100243 * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
244 * @bat_priv: the bat priv with all the soft interface information
245 * @nc_path: the nc path to check
246 *
247 * Returns true if the entry has to be purged now, false otherwise
248 */
249static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
250 struct batadv_nc_path *nc_path)
251{
252 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
253 return true;
254
255 /* purge the path when no packets has been added for 10 times the
256 * max_fwd_delay time
257 */
258 return batadv_has_timed_out(nc_path->last_valid,
259 bat_priv->nc.max_fwd_delay * 10);
260}
261
262/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100263 * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
264 * @bat_priv: the bat priv with all the soft interface information
265 * @nc_path: the nc path to check
266 *
267 * Returns true if the entry has to be purged now, false otherwise
268 */
269static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
270 struct batadv_nc_path *nc_path)
271{
272 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
273 return true;
274
275 /* purge the path when no packets has been added for 10 times the
276 * max_buffer time
277 */
278 return batadv_has_timed_out(nc_path->last_valid,
279 bat_priv->nc.max_buffer_time*10);
280}
281
282/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100283 * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
284 * entries
285 * @bat_priv: the bat priv with all the soft interface information
286 * @list: list of nc nodes
287 * @lock: nc node list lock
288 * @to_purge: function in charge to decide whether an entry has to be purged or
289 * not. This function takes the nc node as argument and has to return
290 * a boolean value: true if the entry has to be deleted, false
291 * otherwise
292 */
293static void
294batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
295 struct list_head *list,
296 spinlock_t *lock,
297 bool (*to_purge)(struct batadv_priv *,
298 struct batadv_nc_node *))
299{
300 struct batadv_nc_node *nc_node, *nc_node_tmp;
301
302 /* For each nc_node in list */
303 spin_lock_bh(lock);
304 list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
305 /* if an helper function has been passed as parameter,
306 * ask it if the entry has to be purged or not
307 */
308 if (to_purge && !to_purge(bat_priv, nc_node))
309 continue;
310
311 batadv_dbg(BATADV_DBG_NC, bat_priv,
312 "Removing nc_node %pM -> %pM\n",
313 nc_node->addr, nc_node->orig_node->orig);
314 list_del_rcu(&nc_node->list);
315 batadv_nc_node_free_ref(nc_node);
316 }
317 spin_unlock_bh(lock);
318}
319
320/**
321 * batadv_nc_purge_orig - purges all nc node data attached of the given
322 * originator
323 * @bat_priv: the bat priv with all the soft interface information
324 * @orig_node: orig_node with the nc node entries to be purged
325 * @to_purge: function in charge to decide whether an entry has to be purged or
326 * not. This function takes the nc node as argument and has to return
327 * a boolean value: true is the entry has to be deleted, false
328 * otherwise
329 */
330void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
331 struct batadv_orig_node *orig_node,
332 bool (*to_purge)(struct batadv_priv *,
333 struct batadv_nc_node *))
334{
335 /* Check ingoing nc_node's of this orig_node */
336 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
337 &orig_node->in_coding_list_lock,
338 to_purge);
339
340 /* Check outgoing nc_node's of this orig_node */
341 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
342 &orig_node->out_coding_list_lock,
343 to_purge);
344}
345
346/**
347 * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
348 * have timed out nc nodes
349 * @bat_priv: the bat priv with all the soft interface information
350 */
351static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
352{
353 struct batadv_hashtable *hash = bat_priv->orig_hash;
354 struct hlist_head *head;
355 struct batadv_orig_node *orig_node;
356 uint32_t i;
357
358 if (!hash)
359 return;
360
361 /* For each orig_node */
362 for (i = 0; i < hash->size; i++) {
363 head = &hash->table[i];
364
365 rcu_read_lock();
366 hlist_for_each_entry_rcu(orig_node, head, hash_entry)
367 batadv_nc_purge_orig(bat_priv, orig_node,
368 batadv_nc_to_purge_nc_node);
369 rcu_read_unlock();
370 }
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100371}
372
373/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100374 * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
375 * unused ones
376 * @bat_priv: the bat priv with all the soft interface information
377 * @hash: hash table containing the nc paths to check
378 * @to_purge: function in charge to decide whether an entry has to be purged or
379 * not. This function takes the nc node as argument and has to return
380 * a boolean value: true is the entry has to be deleted, false
381 * otherwise
382 */
383static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,
384 struct batadv_hashtable *hash,
385 bool (*to_purge)(struct batadv_priv *,
386 struct batadv_nc_path *))
387{
388 struct hlist_head *head;
389 struct hlist_node *node_tmp;
390 struct batadv_nc_path *nc_path;
391 spinlock_t *lock; /* Protects lists in hash */
392 uint32_t i;
393
394 for (i = 0; i < hash->size; i++) {
395 head = &hash->table[i];
396 lock = &hash->list_locks[i];
397
398 /* For each nc_path in this bin */
399 spin_lock_bh(lock);
400 hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) {
401 /* if an helper function has been passed as parameter,
402 * ask it if the entry has to be purged or not
403 */
404 if (to_purge && !to_purge(bat_priv, nc_path))
405 continue;
406
407 /* purging an non-empty nc_path should never happen, but
408 * is observed under high CPU load. Delay the purging
409 * until next iteration to allow the packet_list to be
410 * emptied first.
411 */
412 if (!unlikely(list_empty(&nc_path->packet_list))) {
413 net_ratelimited_function(printk,
414 KERN_WARNING
415 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
416 nc_path->prev_hop,
417 nc_path->next_hop);
418 continue;
419 }
420
421 /* nc_path is unused, so remove it */
422 batadv_dbg(BATADV_DBG_NC, bat_priv,
423 "Remove nc_path %pM -> %pM\n",
424 nc_path->prev_hop, nc_path->next_hop);
425 hlist_del_rcu(&nc_path->hash_entry);
426 batadv_nc_path_free_ref(nc_path);
427 }
428 spin_unlock_bh(lock);
429 }
430}
431
432/**
433 * batadv_nc_hash_key_gen - computes the nc_path hash key
434 * @key: buffer to hold the final hash key
435 * @src: source ethernet mac address going into the hash key
436 * @dst: destination ethernet mac address going into the hash key
437 */
438static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src,
439 const char *dst)
440{
441 memcpy(key->prev_hop, src, sizeof(key->prev_hop));
442 memcpy(key->next_hop, dst, sizeof(key->next_hop));
443}
444
445/**
446 * batadv_nc_hash_choose - compute the hash value for an nc path
447 * @data: data to hash
448 * @size: size of the hash table
449 *
450 * Returns the selected index in the hash table for the given data.
451 */
452static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size)
453{
454 const struct batadv_nc_path *nc_path = data;
455 uint32_t hash = 0;
456
457 hash = batadv_hash_bytes(hash, &nc_path->prev_hop,
458 sizeof(nc_path->prev_hop));
459 hash = batadv_hash_bytes(hash, &nc_path->next_hop,
460 sizeof(nc_path->next_hop));
461
462 hash += (hash << 3);
463 hash ^= (hash >> 11);
464 hash += (hash << 15);
465
466 return hash % size;
467}
468
469/**
470 * batadv_nc_hash_compare - comparing function used in the network coding hash
471 * tables
472 * @node: node in the local table
473 * @data2: second object to compare the node to
474 *
475 * Returns 1 if the two entry are the same, 0 otherwise
476 */
477static int batadv_nc_hash_compare(const struct hlist_node *node,
478 const void *data2)
479{
480 const struct batadv_nc_path *nc_path1, *nc_path2;
481
482 nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
483 nc_path2 = data2;
484
485 /* Return 1 if the two keys are identical */
486 if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop,
487 sizeof(nc_path1->prev_hop)) != 0)
488 return 0;
489
490 if (memcmp(nc_path1->next_hop, nc_path2->next_hop,
491 sizeof(nc_path1->next_hop)) != 0)
492 return 0;
493
494 return 1;
495}
496
497/**
498 * batadv_nc_hash_find - search for an existing nc path and return it
499 * @hash: hash table containing the nc path
500 * @data: search key
501 *
502 * Returns the nc_path if found, NULL otherwise.
503 */
504static struct batadv_nc_path *
505batadv_nc_hash_find(struct batadv_hashtable *hash,
506 void *data)
507{
508 struct hlist_head *head;
509 struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
510 int index;
511
512 if (!hash)
513 return NULL;
514
515 index = batadv_nc_hash_choose(data, hash->size);
516 head = &hash->table[index];
517
518 rcu_read_lock();
519 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
520 if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
521 continue;
522
523 if (!atomic_inc_not_zero(&nc_path->refcount))
524 continue;
525
526 nc_path_tmp = nc_path;
527 break;
528 }
529 rcu_read_unlock();
530
531 return nc_path_tmp;
532}
533
534/**
535 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
536 * @nc_packet: the nc packet to send
537 */
538static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
539{
540 batadv_send_skb_packet(nc_packet->skb,
541 nc_packet->neigh_node->if_incoming,
542 nc_packet->nc_path->next_hop);
543 nc_packet->skb = NULL;
544 batadv_nc_packet_free(nc_packet);
545}
546
547/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100548 * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
549 * @bat_priv: the bat priv with all the soft interface information
550 * @nc_path: the nc path the packet belongs to
551 * @nc_packet: the nc packet to be checked
552 *
553 * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
554 * timeout. If so, the packet is no longer kept and the entry deleted from the
555 * queue. Has to be called with the appropriate locks.
556 *
557 * Returns false as soon as the entry in the fifo queue has not been timed out
558 * yet and true otherwise.
559 */
560static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
561 struct batadv_nc_path *nc_path,
562 struct batadv_nc_packet *nc_packet)
563{
564 unsigned long timeout = bat_priv->nc.max_buffer_time;
565 bool res = false;
566
567 /* Packets are added to tail, so the remaining packets did not time
568 * out and we can stop processing the current queue
569 */
570 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
571 !batadv_has_timed_out(nc_packet->timestamp, timeout))
572 goto out;
573
574 /* purge nc packet */
575 list_del(&nc_packet->list);
576 batadv_nc_packet_free(nc_packet);
577
578 res = true;
579
580out:
581 return res;
582}
583
584/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100585 * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
586 * @bat_priv: the bat priv with all the soft interface information
587 * @nc_path: the nc path the packet belongs to
588 * @nc_packet: the nc packet to be checked
589 *
590 * Checks whether the given nc packet has hit its forward timeout. If so, the
591 * packet is no longer delayed, immediately sent and the entry deleted from the
592 * queue. Has to be called with the appropriate locks.
593 *
594 * Returns false as soon as the entry in the fifo queue has not been timed out
595 * yet and true otherwise.
596 */
597static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,
598 struct batadv_nc_path *nc_path,
599 struct batadv_nc_packet *nc_packet)
600{
601 unsigned long timeout = bat_priv->nc.max_fwd_delay;
602
603 /* Packets are added to tail, so the remaining packets did not time
604 * out and we can stop processing the current queue
605 */
606 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
607 !batadv_has_timed_out(nc_packet->timestamp, timeout))
608 return false;
609
610 /* Send packet */
611 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
612 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
613 nc_packet->skb->len + ETH_HLEN);
614 list_del(&nc_packet->list);
615 batadv_nc_send_packet(nc_packet);
616
617 return true;
618}
619
620/**
621 * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
622 * nc packets
623 * @bat_priv: the bat priv with all the soft interface information
624 * @hash: to be processed hash table
625 * @process_fn: Function called to process given nc packet. Should return true
626 * to encourage this function to proceed with the next packet.
627 * Otherwise the rest of the current queue is skipped.
628 */
629static void
630batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,
631 struct batadv_hashtable *hash,
632 bool (*process_fn)(struct batadv_priv *,
633 struct batadv_nc_path *,
634 struct batadv_nc_packet *))
635{
636 struct hlist_head *head;
637 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
638 struct batadv_nc_path *nc_path;
639 bool ret;
640 int i;
641
642 if (!hash)
643 return;
644
645 /* Loop hash table bins */
646 for (i = 0; i < hash->size; i++) {
647 head = &hash->table[i];
648
649 /* Loop coding paths */
650 rcu_read_lock();
651 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
652 /* Loop packets */
653 spin_lock_bh(&nc_path->packet_list_lock);
654 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
655 &nc_path->packet_list, list) {
656 ret = process_fn(bat_priv, nc_path, nc_packet);
657 if (!ret)
658 break;
659 }
660 spin_unlock_bh(&nc_path->packet_list_lock);
661 }
662 rcu_read_unlock();
663 }
664}
665
666/**
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100667 * batadv_nc_worker - periodic task for house keeping related to network coding
668 * @work: kernel work struct
669 */
670static void batadv_nc_worker(struct work_struct *work)
671{
672 struct delayed_work *delayed_work;
673 struct batadv_priv_nc *priv_nc;
674 struct batadv_priv *bat_priv;
Martin Hundebøll95332472013-01-25 11:12:40 +0100675 unsigned long timeout;
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100676
677 delayed_work = container_of(work, struct delayed_work, work);
678 priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
679 bat_priv = container_of(priv_nc, struct batadv_priv, nc);
680
Martin Hundebølld56b1702013-01-25 11:12:39 +0100681 batadv_nc_purge_orig_hash(bat_priv);
Martin Hundebøll95332472013-01-25 11:12:40 +0100682 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
683 batadv_nc_to_purge_nc_path_coding);
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100684 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
685 batadv_nc_to_purge_nc_path_decoding);
Martin Hundebøll95332472013-01-25 11:12:40 +0100686
687 timeout = bat_priv->nc.max_fwd_delay;
688
689 if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {
690 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
691 batadv_nc_fwd_flush);
692 bat_priv->nc.timestamp_fwd_flush = jiffies;
693 }
Martin Hundebølld56b1702013-01-25 11:12:39 +0100694
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100695 if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
696 bat_priv->nc.max_buffer_time)) {
697 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
698 batadv_nc_sniffed_purge);
699 bat_priv->nc.timestamp_sniffed_purge = jiffies;
700 }
701
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100702 /* Schedule a new check */
703 batadv_nc_start_timer(bat_priv);
704}
705
706/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100707 * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
708 * coding or not
709 * @bat_priv: the bat priv with all the soft interface information
710 * @orig_node: neighboring orig node which may be used as nc candidate
711 * @ogm_packet: incoming ogm packet also used for the checks
712 *
713 * Returns true if:
714 * 1) The OGM must have the most recent sequence number.
715 * 2) The TTL must be decremented by one and only one.
716 * 3) The OGM must be received from the first hop from orig_node.
717 * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
718 */
719static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
720 struct batadv_orig_node *orig_node,
721 struct batadv_ogm_packet *ogm_packet)
722{
Martin Hundebølle6a0b492013-03-14 21:30:21 +0100723 if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno))
Martin Hundebølld56b1702013-01-25 11:12:39 +0100724 return false;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100725 if (orig_node->last_ttl != ogm_packet->ttl + 1)
Martin Hundebølld56b1702013-01-25 11:12:39 +0100726 return false;
727 if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
728 return false;
729 if (ogm_packet->tq < bat_priv->nc.min_tq)
730 return false;
731
732 return true;
733}
734
735/**
736 * batadv_nc_find_nc_node - search for an existing nc node and return it
737 * @orig_node: orig node originating the ogm packet
738 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
739 * (can be equal to orig_node)
740 * @in_coding: traverse incoming or outgoing network coding list
741 *
742 * Returns the nc_node if found, NULL otherwise.
743 */
744static struct batadv_nc_node
745*batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
746 struct batadv_orig_node *orig_neigh_node,
747 bool in_coding)
748{
749 struct batadv_nc_node *nc_node, *nc_node_out = NULL;
750 struct list_head *list;
751
752 if (in_coding)
753 list = &orig_neigh_node->in_coding_list;
754 else
755 list = &orig_neigh_node->out_coding_list;
756
757 /* Traverse list of nc_nodes to orig_node */
758 rcu_read_lock();
759 list_for_each_entry_rcu(nc_node, list, list) {
760 if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
761 continue;
762
763 if (!atomic_inc_not_zero(&nc_node->refcount))
764 continue;
765
766 /* Found a match */
767 nc_node_out = nc_node;
768 break;
769 }
770 rcu_read_unlock();
771
772 return nc_node_out;
773}
774
775/**
776 * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
777 * not found
778 * @bat_priv: the bat priv with all the soft interface information
779 * @orig_node: orig node originating the ogm packet
780 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
781 * (can be equal to orig_node)
782 * @in_coding: traverse incoming or outgoing network coding list
783 *
784 * Returns the nc_node if found or created, NULL in case of an error.
785 */
786static struct batadv_nc_node
787*batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
788 struct batadv_orig_node *orig_node,
789 struct batadv_orig_node *orig_neigh_node,
790 bool in_coding)
791{
792 struct batadv_nc_node *nc_node;
793 spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
794 struct list_head *list;
795
796 /* Check if nc_node is already added */
797 nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
798
799 /* Node found */
800 if (nc_node)
801 return nc_node;
802
803 nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
804 if (!nc_node)
805 return NULL;
806
807 if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
808 goto free;
809
810 /* Initialize nc_node */
811 INIT_LIST_HEAD(&nc_node->list);
812 memcpy(nc_node->addr, orig_node->orig, ETH_ALEN);
813 nc_node->orig_node = orig_neigh_node;
814 atomic_set(&nc_node->refcount, 2);
815
816 /* Select ingoing or outgoing coding node */
817 if (in_coding) {
818 lock = &orig_neigh_node->in_coding_list_lock;
819 list = &orig_neigh_node->in_coding_list;
820 } else {
821 lock = &orig_neigh_node->out_coding_list_lock;
822 list = &orig_neigh_node->out_coding_list;
823 }
824
825 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
826 nc_node->addr, nc_node->orig_node->orig);
827
828 /* Add nc_node to orig_node */
829 spin_lock_bh(lock);
830 list_add_tail_rcu(&nc_node->list, list);
831 spin_unlock_bh(lock);
832
833 return nc_node;
834
835free:
836 kfree(nc_node);
837 return NULL;
838}
839
840/**
841 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs
842 * (best called on incoming OGMs)
843 * @bat_priv: the bat priv with all the soft interface information
844 * @orig_node: orig node originating the ogm packet
845 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
846 * (can be equal to orig_node)
847 * @ogm_packet: incoming ogm packet
848 * @is_single_hop_neigh: orig_node is a single hop neighbor
849 */
850void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
851 struct batadv_orig_node *orig_node,
852 struct batadv_orig_node *orig_neigh_node,
853 struct batadv_ogm_packet *ogm_packet,
854 int is_single_hop_neigh)
855{
856 struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL;
857
858 /* Check if network coding is enabled */
859 if (!atomic_read(&bat_priv->network_coding))
860 goto out;
861
Marek Lindner3f4841f2013-04-23 21:40:00 +0800862 /* check if orig node is network coding enabled */
863 if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC))
864 goto out;
865
Martin Hundebølld56b1702013-01-25 11:12:39 +0100866 /* accept ogms from 'good' neighbors and single hop neighbors */
867 if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
868 !is_single_hop_neigh)
869 goto out;
870
871 /* Add orig_node as in_nc_node on hop */
872 in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
873 orig_neigh_node, true);
874 if (!in_nc_node)
875 goto out;
876
877 in_nc_node->last_seen = jiffies;
878
879 /* Add hop as out_nc_node on orig_node */
880 out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
881 orig_node, false);
882 if (!out_nc_node)
883 goto out;
884
885 out_nc_node->last_seen = jiffies;
886
887out:
888 if (in_nc_node)
889 batadv_nc_node_free_ref(in_nc_node);
890 if (out_nc_node)
891 batadv_nc_node_free_ref(out_nc_node);
892}
893
894/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100895 * batadv_nc_get_path - get existing nc_path or allocate a new one
896 * @bat_priv: the bat priv with all the soft interface information
897 * @hash: hash table containing the nc path
898 * @src: ethernet source address - first half of the nc path search key
899 * @dst: ethernet destination address - second half of the nc path search key
900 *
901 * Returns pointer to nc_path if the path was found or created, returns NULL
902 * on error.
903 */
904static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
905 struct batadv_hashtable *hash,
906 uint8_t *src,
907 uint8_t *dst)
908{
909 int hash_added;
910 struct batadv_nc_path *nc_path, nc_path_key;
911
912 batadv_nc_hash_key_gen(&nc_path_key, src, dst);
913
914 /* Search for existing nc_path */
915 nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
916
917 if (nc_path) {
918 /* Set timestamp to delay removal of nc_path */
919 nc_path->last_valid = jiffies;
920 return nc_path;
921 }
922
923 /* No existing nc_path was found; create a new */
924 nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
925
926 if (!nc_path)
927 return NULL;
928
929 /* Initialize nc_path */
930 INIT_LIST_HEAD(&nc_path->packet_list);
931 spin_lock_init(&nc_path->packet_list_lock);
932 atomic_set(&nc_path->refcount, 2);
933 nc_path->last_valid = jiffies;
934 memcpy(nc_path->next_hop, dst, ETH_ALEN);
935 memcpy(nc_path->prev_hop, src, ETH_ALEN);
936
937 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",
938 nc_path->prev_hop,
939 nc_path->next_hop);
940
941 /* Add nc_path to hash table */
942 hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,
943 batadv_nc_hash_choose, &nc_path_key,
944 &nc_path->hash_entry);
945
946 if (hash_added < 0) {
947 kfree(nc_path);
948 return NULL;
949 }
950
951 return nc_path;
952}
953
954/**
Martin Hundebøll3c12de92013-01-25 11:12:41 +0100955 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
956 * selection of a receiver with slightly lower TQ than the other
957 * @tq: to be weighted tq value
958 */
959static uint8_t batadv_nc_random_weight_tq(uint8_t tq)
960{
961 uint8_t rand_val, rand_tq;
962
963 get_random_bytes(&rand_val, sizeof(rand_val));
964
965 /* randomize the estimated packet loss (max TQ - estimated TQ) */
966 rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
967
968 /* normalize the randomized packet loss */
969 rand_tq /= BATADV_TQ_MAX_VALUE;
970
971 /* convert to (randomized) estimated tq again */
972 return BATADV_TQ_MAX_VALUE - rand_tq;
973}
974
975/**
976 * batadv_nc_memxor - XOR destination with source
977 * @dst: byte array to XOR into
978 * @src: byte array to XOR from
979 * @len: length of destination array
980 */
981static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
982{
983 unsigned int i;
984
985 for (i = 0; i < len; ++i)
986 dst[i] ^= src[i];
987}
988
989/**
990 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
991 * into a coded_packet and send it
992 * @bat_priv: the bat priv with all the soft interface information
993 * @skb: data skb to forward
994 * @ethhdr: pointer to the ethernet header inside the skb
995 * @nc_packet: structure containing the packet to the skb can be coded with
996 * @neigh_node: next hop to forward packet to
997 *
998 * Returns true if both packets are consumed, false otherwise.
999 */
1000static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
1001 struct sk_buff *skb,
1002 struct ethhdr *ethhdr,
1003 struct batadv_nc_packet *nc_packet,
1004 struct batadv_neigh_node *neigh_node)
1005{
Antonio Quartulli0538f752013-09-02 12:15:01 +02001006 uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001007 struct sk_buff *skb_dest, *skb_src;
1008 struct batadv_unicast_packet *packet1;
1009 struct batadv_unicast_packet *packet2;
1010 struct batadv_coded_packet *coded_packet;
1011 struct batadv_neigh_node *neigh_tmp, *router_neigh;
1012 struct batadv_neigh_node *router_coding = NULL;
1013 uint8_t *first_source, *first_dest, *second_source, *second_dest;
1014 __be32 packet_id1, packet_id2;
1015 size_t count;
1016 bool res = false;
1017 int coding_len;
1018 int unicast_size = sizeof(*packet1);
1019 int coded_size = sizeof(*coded_packet);
1020 int header_add = coded_size - unicast_size;
1021
1022 router_neigh = batadv_orig_node_get_router(neigh_node->orig_node);
1023 if (!router_neigh)
1024 goto out;
1025
1026 neigh_tmp = nc_packet->neigh_node;
1027 router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node);
1028 if (!router_coding)
1029 goto out;
1030
Antonio Quartulli0538f752013-09-02 12:15:01 +02001031 tq_tmp = batadv_nc_random_weight_tq(router_neigh->bat_iv.tq_avg);
1032 tq_weighted_neigh = tq_tmp;
1033 tq_tmp = batadv_nc_random_weight_tq(router_coding->bat_iv.tq_avg);
1034 tq_weighted_coding = tq_tmp;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001035
1036 /* Select one destination for the MAC-header dst-field based on
1037 * weighted TQ-values.
1038 */
1039 if (tq_weighted_neigh >= tq_weighted_coding) {
1040 /* Destination from nc_packet is selected for MAC-header */
1041 first_dest = nc_packet->nc_path->next_hop;
1042 first_source = nc_packet->nc_path->prev_hop;
1043 second_dest = neigh_node->addr;
1044 second_source = ethhdr->h_source;
1045 packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1046 packet2 = (struct batadv_unicast_packet *)skb->data;
1047 packet_id1 = nc_packet->packet_id;
1048 packet_id2 = batadv_skb_crc32(skb,
1049 skb->data + sizeof(*packet2));
1050 } else {
1051 /* Destination for skb is selected for MAC-header */
1052 first_dest = neigh_node->addr;
1053 first_source = ethhdr->h_source;
1054 second_dest = nc_packet->nc_path->next_hop;
1055 second_source = nc_packet->nc_path->prev_hop;
1056 packet1 = (struct batadv_unicast_packet *)skb->data;
1057 packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1058 packet_id1 = batadv_skb_crc32(skb,
1059 skb->data + sizeof(*packet1));
1060 packet_id2 = nc_packet->packet_id;
1061 }
1062
1063 /* Instead of zero padding the smallest data buffer, we
1064 * code into the largest.
1065 */
1066 if (skb->len <= nc_packet->skb->len) {
1067 skb_dest = nc_packet->skb;
1068 skb_src = skb;
1069 } else {
1070 skb_dest = skb;
1071 skb_src = nc_packet->skb;
1072 }
1073
1074 /* coding_len is used when decoding the packet shorter packet */
1075 coding_len = skb_src->len - unicast_size;
1076
1077 if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
1078 goto out;
1079
1080 skb_push(skb_dest, header_add);
1081
1082 coded_packet = (struct batadv_coded_packet *)skb_dest->data;
1083 skb_reset_mac_header(skb_dest);
1084
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001085 coded_packet->packet_type = BATADV_CODED;
1086 coded_packet->version = BATADV_COMPAT_VERSION;
1087 coded_packet->ttl = packet1->ttl;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001088
1089 /* Info about first unicast packet */
1090 memcpy(coded_packet->first_source, first_source, ETH_ALEN);
1091 memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN);
1092 coded_packet->first_crc = packet_id1;
1093 coded_packet->first_ttvn = packet1->ttvn;
1094
1095 /* Info about second unicast packet */
1096 memcpy(coded_packet->second_dest, second_dest, ETH_ALEN);
1097 memcpy(coded_packet->second_source, second_source, ETH_ALEN);
1098 memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN);
1099 coded_packet->second_crc = packet_id2;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001100 coded_packet->second_ttl = packet2->ttl;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001101 coded_packet->second_ttvn = packet2->ttvn;
1102 coded_packet->coded_len = htons(coding_len);
1103
1104 /* This is where the magic happens: Code skb_src into skb_dest */
1105 batadv_nc_memxor(skb_dest->data + coded_size,
1106 skb_src->data + unicast_size, coding_len);
1107
1108 /* Update counters accordingly */
1109 if (BATADV_SKB_CB(skb_src)->decoded &&
1110 BATADV_SKB_CB(skb_dest)->decoded) {
1111 /* Both packets are recoded */
1112 count = skb_src->len + ETH_HLEN;
1113 count += skb_dest->len + ETH_HLEN;
1114 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
1115 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
1116 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1117 !BATADV_SKB_CB(skb_dest)->decoded) {
1118 /* Both packets are newly coded */
1119 count = skb_src->len + ETH_HLEN;
1120 count += skb_dest->len + ETH_HLEN;
1121 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
1122 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
1123 } else if (BATADV_SKB_CB(skb_src)->decoded &&
1124 !BATADV_SKB_CB(skb_dest)->decoded) {
1125 /* skb_src recoded and skb_dest is newly coded */
1126 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1127 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1128 skb_src->len + ETH_HLEN);
1129 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1130 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1131 skb_dest->len + ETH_HLEN);
1132 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1133 BATADV_SKB_CB(skb_dest)->decoded) {
1134 /* skb_src is newly coded and skb_dest is recoded */
1135 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1136 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1137 skb_src->len + ETH_HLEN);
1138 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1139 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1140 skb_dest->len + ETH_HLEN);
1141 }
1142
1143 /* skb_src is now coded into skb_dest, so free it */
1144 kfree_skb(skb_src);
1145
1146 /* avoid duplicate free of skb from nc_packet */
1147 nc_packet->skb = NULL;
1148 batadv_nc_packet_free(nc_packet);
1149
1150 /* Send the coded packet and return true */
1151 batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
1152 res = true;
1153out:
1154 if (router_neigh)
1155 batadv_neigh_node_free_ref(router_neigh);
1156 if (router_coding)
1157 batadv_neigh_node_free_ref(router_coding);
1158 return res;
1159}
1160
1161/**
1162 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1163 * @skb: data skb to forward
1164 * @dst: destination mac address of the other skb to code with
1165 * @src: source mac address of skb
1166 *
1167 * Whenever we network code a packet we have to check whether we received it in
1168 * a network coded form. If so, we may not be able to use it for coding because
1169 * some neighbors may also have received (overheard) the packet in the network
1170 * coded form without being able to decode it. It is hard to know which of the
1171 * neighboring nodes was able to decode the packet, therefore we can only
1172 * re-code the packet if the source of the previous encoded packet is involved.
1173 * Since the source encoded the packet we can be certain it has all necessary
1174 * decode information.
1175 *
1176 * Returns true if coding of a decoded packet is allowed.
1177 */
1178static bool batadv_nc_skb_coding_possible(struct sk_buff *skb,
1179 uint8_t *dst, uint8_t *src)
1180{
1181 if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
1182 return false;
1183 else
1184 return true;
1185}
1186
1187/**
1188 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1189 * out_nc_node to retrieve a buffered packet that can be used for coding.
1190 * @bat_priv: the bat priv with all the soft interface information
1191 * @in_nc_node: pointer to skb next hop's neighbor nc node
1192 * @out_nc_node: pointer to skb source's neighbor nc node
1193 * @skb: data skb to forward
1194 * @eth_dst: next hop mac address of skb
1195 *
1196 * Returns true if coding of a decoded skb is allowed.
1197 */
1198static struct batadv_nc_packet *
1199batadv_nc_path_search(struct batadv_priv *bat_priv,
1200 struct batadv_nc_node *in_nc_node,
1201 struct batadv_nc_node *out_nc_node,
1202 struct sk_buff *skb,
1203 uint8_t *eth_dst)
1204{
1205 struct batadv_nc_path *nc_path, nc_path_key;
1206 struct batadv_nc_packet *nc_packet_out = NULL;
1207 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
1208 struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
1209 int idx;
1210
1211 if (!hash)
1212 return NULL;
1213
1214 /* Create almost path key */
1215 batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
1216 out_nc_node->addr);
1217 idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
1218
1219 /* Check for coding opportunities in this nc_path */
1220 rcu_read_lock();
1221 hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
1222 if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
1223 continue;
1224
1225 if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
1226 continue;
1227
1228 spin_lock_bh(&nc_path->packet_list_lock);
1229 if (list_empty(&nc_path->packet_list)) {
1230 spin_unlock_bh(&nc_path->packet_list_lock);
1231 continue;
1232 }
1233
1234 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
1235 &nc_path->packet_list, list) {
1236 if (!batadv_nc_skb_coding_possible(nc_packet->skb,
1237 eth_dst,
1238 in_nc_node->addr))
1239 continue;
1240
1241 /* Coding opportunity is found! */
1242 list_del(&nc_packet->list);
1243 nc_packet_out = nc_packet;
1244 break;
1245 }
1246
1247 spin_unlock_bh(&nc_path->packet_list_lock);
1248 break;
1249 }
1250 rcu_read_unlock();
1251
1252 return nc_packet_out;
1253}
1254
1255/**
1256 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1257 * skb's sender (may be equal to the originator).
1258 * @bat_priv: the bat priv with all the soft interface information
1259 * @skb: data skb to forward
1260 * @eth_dst: next hop mac address of skb
1261 * @eth_src: source mac address of skb
1262 * @in_nc_node: pointer to skb next hop's neighbor nc node
1263 *
1264 * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
1265 */
1266static struct batadv_nc_packet *
1267batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
1268 struct sk_buff *skb,
1269 uint8_t *eth_dst,
1270 uint8_t *eth_src,
1271 struct batadv_nc_node *in_nc_node)
1272{
1273 struct batadv_orig_node *orig_node;
1274 struct batadv_nc_node *out_nc_node;
1275 struct batadv_nc_packet *nc_packet = NULL;
1276
1277 orig_node = batadv_orig_hash_find(bat_priv, eth_src);
1278 if (!orig_node)
1279 return NULL;
1280
1281 rcu_read_lock();
1282 list_for_each_entry_rcu(out_nc_node,
1283 &orig_node->out_coding_list, list) {
1284 /* Check if the skb is decoded and if recoding is possible */
1285 if (!batadv_nc_skb_coding_possible(skb,
1286 out_nc_node->addr, eth_src))
1287 continue;
1288
1289 /* Search for an opportunity in this nc_path */
1290 nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
1291 out_nc_node, skb, eth_dst);
1292 if (nc_packet)
1293 break;
1294 }
1295 rcu_read_unlock();
1296
1297 batadv_orig_node_free_ref(orig_node);
1298 return nc_packet;
1299}
1300
1301/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001302 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1303 * unicast skb before it is stored for use in later decoding
1304 * @bat_priv: the bat priv with all the soft interface information
1305 * @skb: data skb to store
1306 * @eth_dst_new: new destination mac address of skb
1307 */
1308static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
1309 struct sk_buff *skb,
1310 uint8_t *eth_dst_new)
1311{
1312 struct ethhdr *ethhdr;
1313
1314 /* Copy skb header to change the mac header */
1315 skb = pskb_copy(skb, GFP_ATOMIC);
1316 if (!skb)
1317 return;
1318
1319 /* Set the mac header as if we actually sent the packet uncoded */
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001320 ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001321 memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN);
1322 memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN);
1323
1324 /* Set data pointer to MAC header to mimic packets from our tx path */
1325 skb_push(skb, ETH_HLEN);
1326
1327 /* Add the packet to the decoding packet pool */
1328 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1329
1330 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1331 * our ref
1332 */
1333 kfree_skb(skb);
1334}
1335
1336/**
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001337 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1338 * @skb: data skb to forward
1339 * @neigh_node: next hop to forward packet to
1340 * @ethhdr: pointer to the ethernet header inside the skb
1341 *
1342 * Loops through list of neighboring nodes the next hop has a good connection to
1343 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1344 * next hop that potentially sent a packet which our next hop also received
1345 * (overheard) and has stored for later decoding.
1346 *
1347 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1348 */
1349static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
1350 struct batadv_neigh_node *neigh_node,
1351 struct ethhdr *ethhdr)
1352{
1353 struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1354 struct batadv_priv *bat_priv = netdev_priv(netdev);
1355 struct batadv_orig_node *orig_node = neigh_node->orig_node;
1356 struct batadv_nc_node *nc_node;
1357 struct batadv_nc_packet *nc_packet = NULL;
1358
1359 rcu_read_lock();
1360 list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
1361 /* Search for coding opportunity with this in_nc_node */
1362 nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
1363 neigh_node->addr,
1364 ethhdr->h_source, nc_node);
1365
1366 /* Opportunity was found, so stop searching */
1367 if (nc_packet)
1368 break;
1369 }
1370 rcu_read_unlock();
1371
1372 if (!nc_packet)
1373 return false;
1374
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001375 /* Save packets for later decoding */
1376 batadv_nc_skb_store_before_coding(bat_priv, skb,
1377 neigh_node->addr);
1378 batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
1379 nc_packet->neigh_node->addr);
1380
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001381 /* Code and send packets */
1382 if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
1383 neigh_node))
1384 return true;
1385
1386 /* out of mem ? Coding failed - we have to free the buffered packet
1387 * to avoid memleaks. The skb passed as argument will be dealt with
1388 * by the calling function.
1389 */
1390 batadv_nc_send_packet(nc_packet);
1391 return false;
1392}
1393
1394/**
Martin Hundebøll95332472013-01-25 11:12:40 +01001395 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1396 * @skb: skb to add to path
1397 * @nc_path: path to add skb to
1398 * @neigh_node: next hop to forward packet to
1399 * @packet_id: checksum to identify packet
1400 *
1401 * Returns true if the packet was buffered or false in case of an error.
1402 */
1403static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,
1404 struct batadv_nc_path *nc_path,
1405 struct batadv_neigh_node *neigh_node,
1406 __be32 packet_id)
1407{
1408 struct batadv_nc_packet *nc_packet;
1409
1410 nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
1411 if (!nc_packet)
1412 return false;
1413
1414 /* Initialize nc_packet */
1415 nc_packet->timestamp = jiffies;
1416 nc_packet->packet_id = packet_id;
1417 nc_packet->skb = skb;
1418 nc_packet->neigh_node = neigh_node;
1419 nc_packet->nc_path = nc_path;
1420
1421 /* Add coding packet to list */
1422 spin_lock_bh(&nc_path->packet_list_lock);
1423 list_add_tail(&nc_packet->list, &nc_path->packet_list);
1424 spin_unlock_bh(&nc_path->packet_list_lock);
1425
1426 return true;
1427}
1428
1429/**
1430 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1431 * buffer
1432 * @skb: data skb to forward
1433 * @neigh_node: next hop to forward packet to
Martin Hundebøll95332472013-01-25 11:12:40 +01001434 *
1435 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1436 */
1437bool batadv_nc_skb_forward(struct sk_buff *skb,
Martin Hundebølle91ecfc2013-04-20 13:54:39 +02001438 struct batadv_neigh_node *neigh_node)
Martin Hundebøll95332472013-01-25 11:12:40 +01001439{
1440 const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1441 struct batadv_priv *bat_priv = netdev_priv(netdev);
1442 struct batadv_unicast_packet *packet;
1443 struct batadv_nc_path *nc_path;
Martin Hundebølle91ecfc2013-04-20 13:54:39 +02001444 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll95332472013-01-25 11:12:40 +01001445 __be32 packet_id;
1446 u8 *payload;
1447
1448 /* Check if network coding is enabled */
1449 if (!atomic_read(&bat_priv->network_coding))
1450 goto out;
1451
1452 /* We only handle unicast packets */
1453 payload = skb_network_header(skb);
1454 packet = (struct batadv_unicast_packet *)payload;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001455 if (packet->packet_type != BATADV_UNICAST)
Martin Hundebøll95332472013-01-25 11:12:40 +01001456 goto out;
1457
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001458 /* Try to find a coding opportunity and send the skb if one is found */
1459 if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
1460 return true;
1461
Martin Hundebøll95332472013-01-25 11:12:40 +01001462 /* Find or create a nc_path for this src-dst pair */
1463 nc_path = batadv_nc_get_path(bat_priv,
1464 bat_priv->nc.coding_hash,
1465 ethhdr->h_source,
1466 neigh_node->addr);
1467
1468 if (!nc_path)
1469 goto out;
1470
1471 /* Add skb to nc_path */
1472 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1473 if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))
1474 goto free_nc_path;
1475
1476 /* Packet is consumed */
1477 return true;
1478
1479free_nc_path:
1480 batadv_nc_path_free_ref(nc_path);
1481out:
1482 /* Packet is not consumed */
1483 return false;
1484}
1485
1486/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001487 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1488 * when decoding coded packets
1489 * @bat_priv: the bat priv with all the soft interface information
1490 * @skb: data skb to store
1491 */
1492void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
1493 struct sk_buff *skb)
1494{
1495 struct batadv_unicast_packet *packet;
1496 struct batadv_nc_path *nc_path;
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001497 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001498 __be32 packet_id;
1499 u8 *payload;
1500
1501 /* Check if network coding is enabled */
1502 if (!atomic_read(&bat_priv->network_coding))
1503 goto out;
1504
1505 /* Check for supported packet type */
1506 payload = skb_network_header(skb);
1507 packet = (struct batadv_unicast_packet *)payload;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001508 if (packet->packet_type != BATADV_UNICAST)
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001509 goto out;
1510
1511 /* Find existing nc_path or create a new */
1512 nc_path = batadv_nc_get_path(bat_priv,
1513 bat_priv->nc.decoding_hash,
1514 ethhdr->h_source,
1515 ethhdr->h_dest);
1516
1517 if (!nc_path)
1518 goto out;
1519
1520 /* Clone skb and adjust skb->data to point at batman header */
1521 skb = skb_clone(skb, GFP_ATOMIC);
1522 if (unlikely(!skb))
1523 goto free_nc_path;
1524
1525 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
1526 goto free_skb;
1527
1528 if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
1529 goto free_skb;
1530
1531 /* Add skb to nc_path */
1532 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1533 if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
1534 goto free_skb;
1535
1536 batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
1537 return;
1538
1539free_skb:
1540 kfree_skb(skb);
1541free_nc_path:
1542 batadv_nc_path_free_ref(nc_path);
1543out:
1544 return;
1545}
1546
1547/**
1548 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1549 * should be saved in the decoding buffer and, if so, store it there
1550 * @bat_priv: the bat priv with all the soft interface information
1551 * @skb: unicast skb to store
1552 */
1553void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
1554 struct sk_buff *skb)
1555{
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001556 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001557
David S. Miller6e0895c2013-04-22 20:32:51 -04001558 if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001559 return;
1560
1561 /* Set data pointer to MAC header to mimic packets from our tx path */
1562 skb_push(skb, ETH_HLEN);
1563
1564 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1565}
1566
1567/**
Martin Hundebøll2df52782013-01-25 11:12:43 +01001568 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1569 * in nc_packet
David S. Miller6e0895c2013-04-22 20:32:51 -04001570 * @bat_priv: the bat priv with all the soft interface information
Martin Hundebøll2df52782013-01-25 11:12:43 +01001571 * @skb: unicast skb to decode
1572 * @nc_packet: decode data needed to decode the skb
1573 *
1574 * Returns pointer to decoded unicast packet if the packet was decoded or NULL
1575 * in case of an error.
1576 */
1577static struct batadv_unicast_packet *
David S. Miller6e0895c2013-04-22 20:32:51 -04001578batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
Martin Hundebøll2df52782013-01-25 11:12:43 +01001579 struct batadv_nc_packet *nc_packet)
1580{
1581 const int h_size = sizeof(struct batadv_unicast_packet);
1582 const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
1583 struct batadv_unicast_packet *unicast_packet;
1584 struct batadv_coded_packet coded_packet_tmp;
1585 struct ethhdr *ethhdr, ethhdr_tmp;
1586 uint8_t *orig_dest, ttl, ttvn;
1587 unsigned int coding_len;
Marek Lindner7da19972013-05-07 19:25:02 +08001588 int err;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001589
1590 /* Save headers temporarily */
1591 memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
1592 memcpy(&ethhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
1593
1594 if (skb_cow(skb, 0) < 0)
1595 return NULL;
1596
1597 if (unlikely(!skb_pull_rcsum(skb, h_diff)))
1598 return NULL;
1599
1600 /* Data points to batman header, so set mac header 14 bytes before
1601 * and network to data
1602 */
1603 skb_set_mac_header(skb, -ETH_HLEN);
1604 skb_reset_network_header(skb);
1605
1606 /* Reconstruct original mac header */
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001607 ethhdr = eth_hdr(skb);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001608 memcpy(ethhdr, &ethhdr_tmp, sizeof(*ethhdr));
1609
1610 /* Select the correct unicast header information based on the location
1611 * of our mac address in the coded_packet header
1612 */
David S. Miller6e0895c2013-04-22 20:32:51 -04001613 if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
Martin Hundebøll2df52782013-01-25 11:12:43 +01001614 /* If we are the second destination the packet was overheard,
1615 * so the Ethernet address must be copied to h_dest and
1616 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1617 */
1618 memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN);
1619 skb->pkt_type = PACKET_HOST;
1620
1621 orig_dest = coded_packet_tmp.second_orig_dest;
1622 ttl = coded_packet_tmp.second_ttl;
1623 ttvn = coded_packet_tmp.second_ttvn;
1624 } else {
1625 orig_dest = coded_packet_tmp.first_orig_dest;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001626 ttl = coded_packet_tmp.ttl;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001627 ttvn = coded_packet_tmp.first_ttvn;
1628 }
1629
1630 coding_len = ntohs(coded_packet_tmp.coded_len);
1631
1632 if (coding_len > skb->len)
1633 return NULL;
1634
1635 /* Here the magic is reversed:
1636 * extract the missing packet from the received coded packet
1637 */
1638 batadv_nc_memxor(skb->data + h_size,
1639 nc_packet->skb->data + h_size,
1640 coding_len);
1641
1642 /* Resize decoded skb if decoded with larger packet */
Marek Lindner7da19972013-05-07 19:25:02 +08001643 if (nc_packet->skb->len > coding_len + h_size) {
1644 err = pskb_trim_rcsum(skb, coding_len + h_size);
1645 if (err)
1646 return NULL;
1647 }
Martin Hundebøll2df52782013-01-25 11:12:43 +01001648
1649 /* Create decoded unicast packet */
1650 unicast_packet = (struct batadv_unicast_packet *)skb->data;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001651 unicast_packet->packet_type = BATADV_UNICAST;
1652 unicast_packet->version = BATADV_COMPAT_VERSION;
1653 unicast_packet->ttl = ttl;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001654 memcpy(unicast_packet->dest, orig_dest, ETH_ALEN);
1655 unicast_packet->ttvn = ttvn;
1656
1657 batadv_nc_packet_free(nc_packet);
1658 return unicast_packet;
1659}
1660
1661/**
1662 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1663 * find the data needed to decode the coded packet
1664 * @bat_priv: the bat priv with all the soft interface information
1665 * @ethhdr: pointer to the ethernet header inside the coded packet
1666 * @coded: coded packet we try to find decode data for
1667 *
1668 * Returns pointer to nc packet if the needed data was found or NULL otherwise.
1669 */
1670static struct batadv_nc_packet *
1671batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
1672 struct ethhdr *ethhdr,
1673 struct batadv_coded_packet *coded)
1674{
1675 struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
1676 struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
1677 struct batadv_nc_path *nc_path, nc_path_key;
1678 uint8_t *dest, *source;
1679 __be32 packet_id;
1680 int index;
1681
1682 if (!hash)
1683 return NULL;
1684
1685 /* Select the correct packet id based on the location of our mac-addr */
1686 dest = ethhdr->h_source;
David S. Miller6e0895c2013-04-22 20:32:51 -04001687 if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
Martin Hundebøll2df52782013-01-25 11:12:43 +01001688 source = coded->second_source;
1689 packet_id = coded->second_crc;
1690 } else {
1691 source = coded->first_source;
1692 packet_id = coded->first_crc;
1693 }
1694
1695 batadv_nc_hash_key_gen(&nc_path_key, source, dest);
1696 index = batadv_nc_hash_choose(&nc_path_key, hash->size);
1697
1698 /* Search for matching coding path */
1699 rcu_read_lock();
1700 hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
1701 /* Find matching nc_packet */
1702 spin_lock_bh(&nc_path->packet_list_lock);
1703 list_for_each_entry(tmp_nc_packet,
1704 &nc_path->packet_list, list) {
1705 if (packet_id == tmp_nc_packet->packet_id) {
1706 list_del(&tmp_nc_packet->list);
1707
1708 nc_packet = tmp_nc_packet;
1709 break;
1710 }
1711 }
1712 spin_unlock_bh(&nc_path->packet_list_lock);
1713
1714 if (nc_packet)
1715 break;
1716 }
1717 rcu_read_unlock();
1718
1719 if (!nc_packet)
1720 batadv_dbg(BATADV_DBG_NC, bat_priv,
1721 "No decoding packet found for %u\n", packet_id);
1722
1723 return nc_packet;
1724}
1725
1726/**
1727 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1728 * resulting unicast packet
1729 * @skb: incoming coded packet
1730 * @recv_if: pointer to interface this packet was received on
1731 */
1732static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
1733 struct batadv_hard_iface *recv_if)
1734{
1735 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1736 struct batadv_unicast_packet *unicast_packet;
1737 struct batadv_coded_packet *coded_packet;
1738 struct batadv_nc_packet *nc_packet;
1739 struct ethhdr *ethhdr;
1740 int hdr_size = sizeof(*coded_packet);
1741
1742 /* Check if network coding is enabled */
1743 if (!atomic_read(&bat_priv->network_coding))
1744 return NET_RX_DROP;
1745
1746 /* Make sure we can access (and remove) header */
1747 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1748 return NET_RX_DROP;
1749
1750 coded_packet = (struct batadv_coded_packet *)skb->data;
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001751 ethhdr = eth_hdr(skb);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001752
1753 /* Verify frame is destined for us */
David S. Miller6e0895c2013-04-22 20:32:51 -04001754 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
1755 !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
Martin Hundebøll2df52782013-01-25 11:12:43 +01001756 return NET_RX_DROP;
1757
1758 /* Update stat counter */
David S. Miller6e0895c2013-04-22 20:32:51 -04001759 if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
Martin Hundebøll2df52782013-01-25 11:12:43 +01001760 batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
1761
1762 nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
1763 coded_packet);
1764 if (!nc_packet) {
1765 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1766 return NET_RX_DROP;
1767 }
1768
1769 /* Make skb's linear, because decoding accesses the entire buffer */
1770 if (skb_linearize(skb) < 0)
1771 goto free_nc_packet;
1772
1773 if (skb_linearize(nc_packet->skb) < 0)
1774 goto free_nc_packet;
1775
1776 /* Decode the packet */
David S. Miller6e0895c2013-04-22 20:32:51 -04001777 unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001778 if (!unicast_packet) {
1779 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1780 goto free_nc_packet;
1781 }
1782
1783 /* Mark packet as decoded to do correct recoding when forwarding */
1784 BATADV_SKB_CB(skb)->decoded = true;
1785 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
1786 batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
1787 skb->len + ETH_HLEN);
1788 return batadv_recv_unicast_packet(skb, recv_if);
1789
1790free_nc_packet:
1791 batadv_nc_packet_free(nc_packet);
1792 return NET_RX_DROP;
1793}
1794
1795/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +02001796 * batadv_nc_mesh_free - clean up network coding memory
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001797 * @bat_priv: the bat priv with all the soft interface information
1798 */
Matthias Schiffer6c519ba2013-09-27 18:03:39 +02001799void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001800{
Marek Lindner3f4841f2013-04-23 21:40:00 +08001801 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
1802 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1);
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001803 cancel_delayed_work_sync(&bat_priv->nc.work);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001804
Martin Hundebøll95332472013-01-25 11:12:40 +01001805 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
1806 batadv_hash_destroy(bat_priv->nc.coding_hash);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001807 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
1808 batadv_hash_destroy(bat_priv->nc.decoding_hash);
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001809}
Martin Hundebølld56b1702013-01-25 11:12:39 +01001810
1811/**
1812 * batadv_nc_nodes_seq_print_text - print the nc node information
1813 * @seq: seq file to print on
1814 * @offset: not used
1815 */
1816int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
1817{
1818 struct net_device *net_dev = (struct net_device *)seq->private;
1819 struct batadv_priv *bat_priv = netdev_priv(net_dev);
1820 struct batadv_hashtable *hash = bat_priv->orig_hash;
1821 struct batadv_hard_iface *primary_if;
1822 struct hlist_head *head;
1823 struct batadv_orig_node *orig_node;
1824 struct batadv_nc_node *nc_node;
1825 int i;
1826
1827 primary_if = batadv_seq_print_text_primary_if_get(seq);
1828 if (!primary_if)
1829 goto out;
1830
1831 /* Traverse list of originators */
1832 for (i = 0; i < hash->size; i++) {
1833 head = &hash->table[i];
1834
1835 /* For each orig_node in this bin */
1836 rcu_read_lock();
1837 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindneraa27c3122013-04-18 04:56:03 +08001838 /* no need to print the orig node if it does not have
1839 * network coding neighbors
1840 */
1841 if (list_empty(&orig_node->in_coding_list) &&
1842 list_empty(&orig_node->out_coding_list))
1843 continue;
1844
Martin Hundebølld56b1702013-01-25 11:12:39 +01001845 seq_printf(seq, "Node: %pM\n", orig_node->orig);
1846
Antonio Quartulli0c814652013-03-21 09:23:29 +01001847 seq_puts(seq, " Ingoing: ");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001848 /* For each in_nc_node to this orig_node */
1849 list_for_each_entry_rcu(nc_node,
1850 &orig_node->in_coding_list,
1851 list)
1852 seq_printf(seq, "%pM ",
1853 nc_node->addr);
Antonio Quartulli0c814652013-03-21 09:23:29 +01001854 seq_puts(seq, "\n");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001855
Antonio Quartulli0c814652013-03-21 09:23:29 +01001856 seq_puts(seq, " Outgoing: ");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001857 /* For out_nc_node to this orig_node */
1858 list_for_each_entry_rcu(nc_node,
1859 &orig_node->out_coding_list,
1860 list)
1861 seq_printf(seq, "%pM ",
1862 nc_node->addr);
Antonio Quartulli0c814652013-03-21 09:23:29 +01001863 seq_puts(seq, "\n\n");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001864 }
1865 rcu_read_unlock();
1866 }
1867
1868out:
1869 if (primary_if)
1870 batadv_hardif_free_ref(primary_if);
1871 return 0;
1872}
1873
1874/**
1875 * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1876 * @bat_priv: the bat priv with all the soft interface information
1877 */
1878int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
1879{
1880 struct dentry *nc_dir, *file;
1881
1882 nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
1883 if (!nc_dir)
1884 goto out;
1885
1886 file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
1887 &bat_priv->nc.min_tq);
1888 if (!file)
1889 goto out;
1890
Martin Hundebøll95332472013-01-25 11:12:40 +01001891 file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,
1892 &bat_priv->nc.max_fwd_delay);
1893 if (!file)
1894 goto out;
1895
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001896 file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
1897 &bat_priv->nc.max_buffer_time);
1898 if (!file)
1899 goto out;
1900
Martin Hundebølld56b1702013-01-25 11:12:39 +01001901 return 0;
1902
1903out:
1904 return -ENOMEM;
1905}