blob: f1b604d88dc3c2124c86083f36e5bafaad50b9bc [file] [log] [blame]
Simon Wunderliche19f9752014-01-04 18:04:25 +01001/* Copyright (C) 2012-2014 B.A.T.M.A.N. contributors:
Martin Hundebølld353d8d2013-01-25 11:12:38 +01002 *
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
Antonio Quartulliebf38fb2013-11-03 20:40:48 +010015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Martin Hundebølld353d8d2013-01-25 11:12:38 +010016 */
17
Martin Hundebølld56b1702013-01-25 11:12:39 +010018#include <linux/debugfs.h>
19
Martin Hundebølld353d8d2013-01-25 11:12:38 +010020#include "main.h"
Martin Hundebøll95332472013-01-25 11:12:40 +010021#include "hash.h"
Martin Hundebølld353d8d2013-01-25 11:12:38 +010022#include "network-coding.h"
Martin Hundebøll95332472013-01-25 11:12:40 +010023#include "send.h"
Martin Hundebølld56b1702013-01-25 11:12:39 +010024#include "originator.h"
25#include "hard-interface.h"
Martin Hundebøll2df52782013-01-25 11:12:43 +010026#include "routing.h"
Martin Hundebølld353d8d2013-01-25 11:12:38 +010027
Martin Hundebøll95332472013-01-25 11:12:40 +010028static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
Martin Hundebøll612d2b42013-01-25 11:12:42 +010029static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
Martin Hundebøll95332472013-01-25 11:12:40 +010030
Martin Hundebølld353d8d2013-01-25 11:12:38 +010031static void batadv_nc_worker(struct work_struct *work);
Martin Hundebøll2df52782013-01-25 11:12:43 +010032static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
33 struct batadv_hard_iface *recv_if);
Martin Hundebølld353d8d2013-01-25 11:12:38 +010034
35/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +020036 * batadv_nc_init - one-time initialization for network coding
37 */
38int __init batadv_nc_init(void)
39{
40 int ret;
41
42 /* Register our packet type */
43 ret = batadv_recv_handler_register(BATADV_CODED,
44 batadv_nc_recv_coded_packet);
45
46 return ret;
47}
48
49/**
Martin Hundebølld353d8d2013-01-25 11:12:38 +010050 * batadv_nc_start_timer - initialise the nc periodic worker
51 * @bat_priv: the bat priv with all the soft interface information
52 */
53static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
54{
55 queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
56 msecs_to_jiffies(10));
57}
58
59/**
Marek Lindner3f4841f2013-04-23 21:40:00 +080060 * batadv_nc_tvlv_container_update - update the network coding tvlv container
61 * after network coding setting change
62 * @bat_priv: the bat priv with all the soft interface information
63 */
64static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv)
65{
66 char nc_mode;
67
68 nc_mode = atomic_read(&bat_priv->network_coding);
69
70 switch (nc_mode) {
71 case 0:
72 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
73 break;
74 case 1:
75 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1,
76 NULL, 0);
77 break;
78 }
79}
80
81/**
82 * batadv_nc_status_update - update the network coding tvlv container after
83 * network coding setting change
84 * @net_dev: the soft interface net device
85 */
86void batadv_nc_status_update(struct net_device *net_dev)
87{
88 struct batadv_priv *bat_priv = netdev_priv(net_dev);
89 batadv_nc_tvlv_container_update(bat_priv);
90}
91
92/**
93 * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
94 * @bat_priv: the bat priv with all the soft interface information
95 * @orig: the orig_node of the ogm
96 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
97 * @tvlv_value: tvlv buffer containing the gateway data
98 * @tvlv_value_len: tvlv buffer length
99 */
100static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
101 struct batadv_orig_node *orig,
102 uint8_t flags,
103 void *tvlv_value,
104 uint16_t tvlv_value_len)
105{
106 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
107 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC;
108 else
109 orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC;
110}
111
112/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +0200113 * batadv_nc_mesh_init - initialise coding hash table and start house keeping
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100114 * @bat_priv: the bat priv with all the soft interface information
115 */
Matthias Schiffer6c519ba2013-09-27 18:03:39 +0200116int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100117{
Martin Hundebøll95332472013-01-25 11:12:40 +0100118 bat_priv->nc.timestamp_fwd_flush = jiffies;
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100119 bat_priv->nc.timestamp_sniffed_purge = jiffies;
Martin Hundebøll95332472013-01-25 11:12:40 +0100120
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100121 if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
Martin Hundebøll95332472013-01-25 11:12:40 +0100122 return 0;
123
124 bat_priv->nc.coding_hash = batadv_hash_new(128);
125 if (!bat_priv->nc.coding_hash)
126 goto err;
127
128 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
129 &batadv_nc_coding_hash_lock_class_key);
130
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100131 bat_priv->nc.decoding_hash = batadv_hash_new(128);
132 if (!bat_priv->nc.decoding_hash)
133 goto err;
134
135 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
136 &batadv_nc_decoding_hash_lock_class_key);
137
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100138 INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
139 batadv_nc_start_timer(bat_priv);
140
Marek Lindner3f4841f2013-04-23 21:40:00 +0800141 batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1,
142 NULL, BATADV_TVLV_NC, 1,
143 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
144 batadv_nc_tvlv_container_update(bat_priv);
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100145 return 0;
Martin Hundebøll95332472013-01-25 11:12:40 +0100146
147err:
148 return -ENOMEM;
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100149}
150
151/**
152 * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
153 * @bat_priv: the bat priv with all the soft interface information
154 */
155void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
156{
157 atomic_set(&bat_priv->network_coding, 1);
Martin Hundebølld56b1702013-01-25 11:12:39 +0100158 bat_priv->nc.min_tq = 200;
Martin Hundebøll95332472013-01-25 11:12:40 +0100159 bat_priv->nc.max_fwd_delay = 10;
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100160 bat_priv->nc.max_buffer_time = 200;
Martin Hundebølld56b1702013-01-25 11:12:39 +0100161}
162
163/**
164 * batadv_nc_init_orig - initialise the nc fields of an orig_node
165 * @orig_node: the orig_node which is going to be initialised
166 */
167void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
168{
169 INIT_LIST_HEAD(&orig_node->in_coding_list);
170 INIT_LIST_HEAD(&orig_node->out_coding_list);
171 spin_lock_init(&orig_node->in_coding_list_lock);
172 spin_lock_init(&orig_node->out_coding_list_lock);
173}
174
175/**
176 * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove
177 * its refcount on the orig_node
178 * @rcu: rcu pointer of the nc node
179 */
180static void batadv_nc_node_free_rcu(struct rcu_head *rcu)
181{
182 struct batadv_nc_node *nc_node;
183
184 nc_node = container_of(rcu, struct batadv_nc_node, rcu);
185 batadv_orig_node_free_ref(nc_node->orig_node);
186 kfree(nc_node);
187}
188
189/**
190 * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly
191 * frees it
192 * @nc_node: the nc node to free
193 */
194static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
195{
196 if (atomic_dec_and_test(&nc_node->refcount))
197 call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu);
198}
199
200/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100201 * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
202 * frees it
203 * @nc_path: the nc node to free
204 */
205static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path)
206{
207 if (atomic_dec_and_test(&nc_path->refcount))
208 kfree_rcu(nc_path, rcu);
209}
210
211/**
212 * batadv_nc_packet_free - frees nc packet
213 * @nc_packet: the nc packet to free
214 */
215static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet)
216{
217 if (nc_packet->skb)
218 kfree_skb(nc_packet->skb);
219
220 batadv_nc_path_free_ref(nc_packet->nc_path);
221 kfree(nc_packet);
222}
223
224/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100225 * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
226 * @bat_priv: the bat priv with all the soft interface information
227 * @nc_node: the nc node to check
228 *
229 * Returns true if the entry has to be purged now, false otherwise
230 */
231static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
232 struct batadv_nc_node *nc_node)
233{
234 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
235 return true;
236
237 return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
238}
239
240/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100241 * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
242 * @bat_priv: the bat priv with all the soft interface information
243 * @nc_path: the nc path to check
244 *
245 * Returns true if the entry has to be purged now, false otherwise
246 */
247static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
248 struct batadv_nc_path *nc_path)
249{
250 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
251 return true;
252
253 /* purge the path when no packets has been added for 10 times the
254 * max_fwd_delay time
255 */
256 return batadv_has_timed_out(nc_path->last_valid,
257 bat_priv->nc.max_fwd_delay * 10);
258}
259
260/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100261 * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
262 * @bat_priv: the bat priv with all the soft interface information
263 * @nc_path: the nc path to check
264 *
265 * Returns true if the entry has to be purged now, false otherwise
266 */
267static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
268 struct batadv_nc_path *nc_path)
269{
270 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
271 return true;
272
273 /* purge the path when no packets has been added for 10 times the
274 * max_buffer time
275 */
276 return batadv_has_timed_out(nc_path->last_valid,
277 bat_priv->nc.max_buffer_time*10);
278}
279
280/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100281 * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
282 * entries
283 * @bat_priv: the bat priv with all the soft interface information
284 * @list: list of nc nodes
285 * @lock: nc node list lock
286 * @to_purge: function in charge to decide whether an entry has to be purged or
287 * not. This function takes the nc node as argument and has to return
288 * a boolean value: true if the entry has to be deleted, false
289 * otherwise
290 */
291static void
292batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
293 struct list_head *list,
294 spinlock_t *lock,
295 bool (*to_purge)(struct batadv_priv *,
296 struct batadv_nc_node *))
297{
298 struct batadv_nc_node *nc_node, *nc_node_tmp;
299
300 /* For each nc_node in list */
301 spin_lock_bh(lock);
302 list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
303 /* if an helper function has been passed as parameter,
304 * ask it if the entry has to be purged or not
305 */
306 if (to_purge && !to_purge(bat_priv, nc_node))
307 continue;
308
309 batadv_dbg(BATADV_DBG_NC, bat_priv,
310 "Removing nc_node %pM -> %pM\n",
311 nc_node->addr, nc_node->orig_node->orig);
312 list_del_rcu(&nc_node->list);
313 batadv_nc_node_free_ref(nc_node);
314 }
315 spin_unlock_bh(lock);
316}
317
318/**
319 * batadv_nc_purge_orig - purges all nc node data attached of the given
320 * originator
321 * @bat_priv: the bat priv with all the soft interface information
322 * @orig_node: orig_node with the nc node entries to be purged
323 * @to_purge: function in charge to decide whether an entry has to be purged or
324 * not. This function takes the nc node as argument and has to return
325 * a boolean value: true is the entry has to be deleted, false
326 * otherwise
327 */
328void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
329 struct batadv_orig_node *orig_node,
330 bool (*to_purge)(struct batadv_priv *,
331 struct batadv_nc_node *))
332{
333 /* Check ingoing nc_node's of this orig_node */
334 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
335 &orig_node->in_coding_list_lock,
336 to_purge);
337
338 /* Check outgoing nc_node's of this orig_node */
339 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
340 &orig_node->out_coding_list_lock,
341 to_purge);
342}
343
344/**
345 * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
346 * have timed out nc nodes
347 * @bat_priv: the bat priv with all the soft interface information
348 */
349static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
350{
351 struct batadv_hashtable *hash = bat_priv->orig_hash;
352 struct hlist_head *head;
353 struct batadv_orig_node *orig_node;
354 uint32_t i;
355
356 if (!hash)
357 return;
358
359 /* For each orig_node */
360 for (i = 0; i < hash->size; i++) {
361 head = &hash->table[i];
362
363 rcu_read_lock();
364 hlist_for_each_entry_rcu(orig_node, head, hash_entry)
365 batadv_nc_purge_orig(bat_priv, orig_node,
366 batadv_nc_to_purge_nc_node);
367 rcu_read_unlock();
368 }
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100369}
370
371/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100372 * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
373 * unused ones
374 * @bat_priv: the bat priv with all the soft interface information
375 * @hash: hash table containing the nc paths to check
376 * @to_purge: function in charge to decide whether an entry has to be purged or
377 * not. This function takes the nc node as argument and has to return
378 * a boolean value: true is the entry has to be deleted, false
379 * otherwise
380 */
381static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,
382 struct batadv_hashtable *hash,
383 bool (*to_purge)(struct batadv_priv *,
384 struct batadv_nc_path *))
385{
386 struct hlist_head *head;
387 struct hlist_node *node_tmp;
388 struct batadv_nc_path *nc_path;
389 spinlock_t *lock; /* Protects lists in hash */
390 uint32_t i;
391
392 for (i = 0; i < hash->size; i++) {
393 head = &hash->table[i];
394 lock = &hash->list_locks[i];
395
396 /* For each nc_path in this bin */
397 spin_lock_bh(lock);
398 hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) {
399 /* if an helper function has been passed as parameter,
400 * ask it if the entry has to be purged or not
401 */
402 if (to_purge && !to_purge(bat_priv, nc_path))
403 continue;
404
405 /* purging an non-empty nc_path should never happen, but
406 * is observed under high CPU load. Delay the purging
407 * until next iteration to allow the packet_list to be
408 * emptied first.
409 */
410 if (!unlikely(list_empty(&nc_path->packet_list))) {
411 net_ratelimited_function(printk,
412 KERN_WARNING
413 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
414 nc_path->prev_hop,
415 nc_path->next_hop);
416 continue;
417 }
418
419 /* nc_path is unused, so remove it */
420 batadv_dbg(BATADV_DBG_NC, bat_priv,
421 "Remove nc_path %pM -> %pM\n",
422 nc_path->prev_hop, nc_path->next_hop);
423 hlist_del_rcu(&nc_path->hash_entry);
424 batadv_nc_path_free_ref(nc_path);
425 }
426 spin_unlock_bh(lock);
427 }
428}
429
430/**
431 * batadv_nc_hash_key_gen - computes the nc_path hash key
432 * @key: buffer to hold the final hash key
433 * @src: source ethernet mac address going into the hash key
434 * @dst: destination ethernet mac address going into the hash key
435 */
436static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src,
437 const char *dst)
438{
439 memcpy(key->prev_hop, src, sizeof(key->prev_hop));
440 memcpy(key->next_hop, dst, sizeof(key->next_hop));
441}
442
443/**
444 * batadv_nc_hash_choose - compute the hash value for an nc path
445 * @data: data to hash
446 * @size: size of the hash table
447 *
448 * Returns the selected index in the hash table for the given data.
449 */
450static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size)
451{
452 const struct batadv_nc_path *nc_path = data;
453 uint32_t hash = 0;
454
455 hash = batadv_hash_bytes(hash, &nc_path->prev_hop,
456 sizeof(nc_path->prev_hop));
457 hash = batadv_hash_bytes(hash, &nc_path->next_hop,
458 sizeof(nc_path->next_hop));
459
460 hash += (hash << 3);
461 hash ^= (hash >> 11);
462 hash += (hash << 15);
463
464 return hash % size;
465}
466
467/**
468 * batadv_nc_hash_compare - comparing function used in the network coding hash
469 * tables
470 * @node: node in the local table
471 * @data2: second object to compare the node to
472 *
473 * Returns 1 if the two entry are the same, 0 otherwise
474 */
475static int batadv_nc_hash_compare(const struct hlist_node *node,
476 const void *data2)
477{
478 const struct batadv_nc_path *nc_path1, *nc_path2;
479
480 nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
481 nc_path2 = data2;
482
483 /* Return 1 if the two keys are identical */
484 if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop,
485 sizeof(nc_path1->prev_hop)) != 0)
486 return 0;
487
488 if (memcmp(nc_path1->next_hop, nc_path2->next_hop,
489 sizeof(nc_path1->next_hop)) != 0)
490 return 0;
491
492 return 1;
493}
494
495/**
496 * batadv_nc_hash_find - search for an existing nc path and return it
497 * @hash: hash table containing the nc path
498 * @data: search key
499 *
500 * Returns the nc_path if found, NULL otherwise.
501 */
502static struct batadv_nc_path *
503batadv_nc_hash_find(struct batadv_hashtable *hash,
504 void *data)
505{
506 struct hlist_head *head;
507 struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
508 int index;
509
510 if (!hash)
511 return NULL;
512
513 index = batadv_nc_hash_choose(data, hash->size);
514 head = &hash->table[index];
515
516 rcu_read_lock();
517 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
518 if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
519 continue;
520
521 if (!atomic_inc_not_zero(&nc_path->refcount))
522 continue;
523
524 nc_path_tmp = nc_path;
525 break;
526 }
527 rcu_read_unlock();
528
529 return nc_path_tmp;
530}
531
532/**
533 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
534 * @nc_packet: the nc packet to send
535 */
536static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
537{
538 batadv_send_skb_packet(nc_packet->skb,
539 nc_packet->neigh_node->if_incoming,
540 nc_packet->nc_path->next_hop);
541 nc_packet->skb = NULL;
542 batadv_nc_packet_free(nc_packet);
543}
544
545/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100546 * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
547 * @bat_priv: the bat priv with all the soft interface information
548 * @nc_path: the nc path the packet belongs to
549 * @nc_packet: the nc packet to be checked
550 *
551 * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
552 * timeout. If so, the packet is no longer kept and the entry deleted from the
553 * queue. Has to be called with the appropriate locks.
554 *
555 * Returns false as soon as the entry in the fifo queue has not been timed out
556 * yet and true otherwise.
557 */
558static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
559 struct batadv_nc_path *nc_path,
560 struct batadv_nc_packet *nc_packet)
561{
562 unsigned long timeout = bat_priv->nc.max_buffer_time;
563 bool res = false;
564
565 /* Packets are added to tail, so the remaining packets did not time
566 * out and we can stop processing the current queue
567 */
568 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
569 !batadv_has_timed_out(nc_packet->timestamp, timeout))
570 goto out;
571
572 /* purge nc packet */
573 list_del(&nc_packet->list);
574 batadv_nc_packet_free(nc_packet);
575
576 res = true;
577
578out:
579 return res;
580}
581
582/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100583 * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
584 * @bat_priv: the bat priv with all the soft interface information
585 * @nc_path: the nc path the packet belongs to
586 * @nc_packet: the nc packet to be checked
587 *
588 * Checks whether the given nc packet has hit its forward timeout. If so, the
589 * packet is no longer delayed, immediately sent and the entry deleted from the
590 * queue. Has to be called with the appropriate locks.
591 *
592 * Returns false as soon as the entry in the fifo queue has not been timed out
593 * yet and true otherwise.
594 */
595static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,
596 struct batadv_nc_path *nc_path,
597 struct batadv_nc_packet *nc_packet)
598{
599 unsigned long timeout = bat_priv->nc.max_fwd_delay;
600
601 /* Packets are added to tail, so the remaining packets did not time
602 * out and we can stop processing the current queue
603 */
604 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
605 !batadv_has_timed_out(nc_packet->timestamp, timeout))
606 return false;
607
608 /* Send packet */
609 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
610 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
611 nc_packet->skb->len + ETH_HLEN);
612 list_del(&nc_packet->list);
613 batadv_nc_send_packet(nc_packet);
614
615 return true;
616}
617
618/**
619 * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
620 * nc packets
621 * @bat_priv: the bat priv with all the soft interface information
622 * @hash: to be processed hash table
623 * @process_fn: Function called to process given nc packet. Should return true
624 * to encourage this function to proceed with the next packet.
625 * Otherwise the rest of the current queue is skipped.
626 */
627static void
628batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,
629 struct batadv_hashtable *hash,
630 bool (*process_fn)(struct batadv_priv *,
631 struct batadv_nc_path *,
632 struct batadv_nc_packet *))
633{
634 struct hlist_head *head;
635 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
636 struct batadv_nc_path *nc_path;
637 bool ret;
638 int i;
639
640 if (!hash)
641 return;
642
643 /* Loop hash table bins */
644 for (i = 0; i < hash->size; i++) {
645 head = &hash->table[i];
646
647 /* Loop coding paths */
648 rcu_read_lock();
649 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
650 /* Loop packets */
651 spin_lock_bh(&nc_path->packet_list_lock);
652 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
653 &nc_path->packet_list, list) {
654 ret = process_fn(bat_priv, nc_path, nc_packet);
655 if (!ret)
656 break;
657 }
658 spin_unlock_bh(&nc_path->packet_list_lock);
659 }
660 rcu_read_unlock();
661 }
662}
663
664/**
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100665 * batadv_nc_worker - periodic task for house keeping related to network coding
666 * @work: kernel work struct
667 */
668static void batadv_nc_worker(struct work_struct *work)
669{
670 struct delayed_work *delayed_work;
671 struct batadv_priv_nc *priv_nc;
672 struct batadv_priv *bat_priv;
Martin Hundebøll95332472013-01-25 11:12:40 +0100673 unsigned long timeout;
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100674
675 delayed_work = container_of(work, struct delayed_work, work);
676 priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
677 bat_priv = container_of(priv_nc, struct batadv_priv, nc);
678
Martin Hundebølld56b1702013-01-25 11:12:39 +0100679 batadv_nc_purge_orig_hash(bat_priv);
Martin Hundebøll95332472013-01-25 11:12:40 +0100680 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
681 batadv_nc_to_purge_nc_path_coding);
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100682 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
683 batadv_nc_to_purge_nc_path_decoding);
Martin Hundebøll95332472013-01-25 11:12:40 +0100684
685 timeout = bat_priv->nc.max_fwd_delay;
686
687 if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {
688 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
689 batadv_nc_fwd_flush);
690 bat_priv->nc.timestamp_fwd_flush = jiffies;
691 }
Martin Hundebølld56b1702013-01-25 11:12:39 +0100692
Martin Hundebøll612d2b42013-01-25 11:12:42 +0100693 if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
694 bat_priv->nc.max_buffer_time)) {
695 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
696 batadv_nc_sniffed_purge);
697 bat_priv->nc.timestamp_sniffed_purge = jiffies;
698 }
699
Martin Hundebølld353d8d2013-01-25 11:12:38 +0100700 /* Schedule a new check */
701 batadv_nc_start_timer(bat_priv);
702}
703
704/**
Martin Hundebølld56b1702013-01-25 11:12:39 +0100705 * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
706 * coding or not
707 * @bat_priv: the bat priv with all the soft interface information
708 * @orig_node: neighboring orig node which may be used as nc candidate
709 * @ogm_packet: incoming ogm packet also used for the checks
710 *
711 * Returns true if:
712 * 1) The OGM must have the most recent sequence number.
713 * 2) The TTL must be decremented by one and only one.
714 * 3) The OGM must be received from the first hop from orig_node.
715 * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
716 */
717static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
718 struct batadv_orig_node *orig_node,
719 struct batadv_ogm_packet *ogm_packet)
720{
Simon Wunderlich7351a4822013-11-13 19:14:47 +0100721 struct batadv_orig_ifinfo *orig_ifinfo;
722 uint32_t last_real_seqno;
723 uint8_t last_ttl;
724
725 orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT);
726 if (!orig_ifinfo)
Martin Hundebølld56b1702013-01-25 11:12:39 +0100727 return false;
Simon Wunderlich7351a4822013-11-13 19:14:47 +0100728
729 last_ttl = orig_ifinfo->last_ttl;
730 last_real_seqno = orig_ifinfo->last_real_seqno;
731 batadv_orig_ifinfo_free_ref(orig_ifinfo);
732
733 if (last_real_seqno != ntohl(ogm_packet->seqno))
734 return false;
735 if (last_ttl != ogm_packet->ttl + 1)
Martin Hundebølld56b1702013-01-25 11:12:39 +0100736 return false;
737 if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
738 return false;
739 if (ogm_packet->tq < bat_priv->nc.min_tq)
740 return false;
741
742 return true;
743}
744
745/**
746 * batadv_nc_find_nc_node - search for an existing nc node and return it
747 * @orig_node: orig node originating the ogm packet
748 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
749 * (can be equal to orig_node)
750 * @in_coding: traverse incoming or outgoing network coding list
751 *
752 * Returns the nc_node if found, NULL otherwise.
753 */
754static struct batadv_nc_node
755*batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
756 struct batadv_orig_node *orig_neigh_node,
757 bool in_coding)
758{
759 struct batadv_nc_node *nc_node, *nc_node_out = NULL;
760 struct list_head *list;
761
762 if (in_coding)
763 list = &orig_neigh_node->in_coding_list;
764 else
765 list = &orig_neigh_node->out_coding_list;
766
767 /* Traverse list of nc_nodes to orig_node */
768 rcu_read_lock();
769 list_for_each_entry_rcu(nc_node, list, list) {
770 if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
771 continue;
772
773 if (!atomic_inc_not_zero(&nc_node->refcount))
774 continue;
775
776 /* Found a match */
777 nc_node_out = nc_node;
778 break;
779 }
780 rcu_read_unlock();
781
782 return nc_node_out;
783}
784
785/**
786 * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
787 * not found
788 * @bat_priv: the bat priv with all the soft interface information
789 * @orig_node: orig node originating the ogm packet
790 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
791 * (can be equal to orig_node)
792 * @in_coding: traverse incoming or outgoing network coding list
793 *
794 * Returns the nc_node if found or created, NULL in case of an error.
795 */
796static struct batadv_nc_node
797*batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
798 struct batadv_orig_node *orig_node,
799 struct batadv_orig_node *orig_neigh_node,
800 bool in_coding)
801{
802 struct batadv_nc_node *nc_node;
803 spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
804 struct list_head *list;
805
806 /* Check if nc_node is already added */
807 nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
808
809 /* Node found */
810 if (nc_node)
811 return nc_node;
812
813 nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
814 if (!nc_node)
815 return NULL;
816
817 if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
818 goto free;
819
820 /* Initialize nc_node */
821 INIT_LIST_HEAD(&nc_node->list);
822 memcpy(nc_node->addr, orig_node->orig, ETH_ALEN);
823 nc_node->orig_node = orig_neigh_node;
824 atomic_set(&nc_node->refcount, 2);
825
826 /* Select ingoing or outgoing coding node */
827 if (in_coding) {
828 lock = &orig_neigh_node->in_coding_list_lock;
829 list = &orig_neigh_node->in_coding_list;
830 } else {
831 lock = &orig_neigh_node->out_coding_list_lock;
832 list = &orig_neigh_node->out_coding_list;
833 }
834
835 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
836 nc_node->addr, nc_node->orig_node->orig);
837
838 /* Add nc_node to orig_node */
839 spin_lock_bh(lock);
840 list_add_tail_rcu(&nc_node->list, list);
841 spin_unlock_bh(lock);
842
843 return nc_node;
844
845free:
846 kfree(nc_node);
847 return NULL;
848}
849
850/**
851 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs
852 * (best called on incoming OGMs)
853 * @bat_priv: the bat priv with all the soft interface information
854 * @orig_node: orig node originating the ogm packet
855 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
856 * (can be equal to orig_node)
857 * @ogm_packet: incoming ogm packet
858 * @is_single_hop_neigh: orig_node is a single hop neighbor
859 */
860void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
861 struct batadv_orig_node *orig_node,
862 struct batadv_orig_node *orig_neigh_node,
863 struct batadv_ogm_packet *ogm_packet,
864 int is_single_hop_neigh)
865{
866 struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL;
867
868 /* Check if network coding is enabled */
869 if (!atomic_read(&bat_priv->network_coding))
870 goto out;
871
Marek Lindner3f4841f2013-04-23 21:40:00 +0800872 /* check if orig node is network coding enabled */
873 if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC))
874 goto out;
875
Martin Hundebølld56b1702013-01-25 11:12:39 +0100876 /* accept ogms from 'good' neighbors and single hop neighbors */
877 if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
878 !is_single_hop_neigh)
879 goto out;
880
881 /* Add orig_node as in_nc_node on hop */
882 in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
883 orig_neigh_node, true);
884 if (!in_nc_node)
885 goto out;
886
887 in_nc_node->last_seen = jiffies;
888
889 /* Add hop as out_nc_node on orig_node */
890 out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
891 orig_node, false);
892 if (!out_nc_node)
893 goto out;
894
895 out_nc_node->last_seen = jiffies;
896
897out:
898 if (in_nc_node)
899 batadv_nc_node_free_ref(in_nc_node);
900 if (out_nc_node)
901 batadv_nc_node_free_ref(out_nc_node);
902}
903
904/**
Martin Hundebøll95332472013-01-25 11:12:40 +0100905 * batadv_nc_get_path - get existing nc_path or allocate a new one
906 * @bat_priv: the bat priv with all the soft interface information
907 * @hash: hash table containing the nc path
908 * @src: ethernet source address - first half of the nc path search key
909 * @dst: ethernet destination address - second half of the nc path search key
910 *
911 * Returns pointer to nc_path if the path was found or created, returns NULL
912 * on error.
913 */
914static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
915 struct batadv_hashtable *hash,
916 uint8_t *src,
917 uint8_t *dst)
918{
919 int hash_added;
920 struct batadv_nc_path *nc_path, nc_path_key;
921
922 batadv_nc_hash_key_gen(&nc_path_key, src, dst);
923
924 /* Search for existing nc_path */
925 nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
926
927 if (nc_path) {
928 /* Set timestamp to delay removal of nc_path */
929 nc_path->last_valid = jiffies;
930 return nc_path;
931 }
932
933 /* No existing nc_path was found; create a new */
934 nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
935
936 if (!nc_path)
937 return NULL;
938
939 /* Initialize nc_path */
940 INIT_LIST_HEAD(&nc_path->packet_list);
941 spin_lock_init(&nc_path->packet_list_lock);
942 atomic_set(&nc_path->refcount, 2);
943 nc_path->last_valid = jiffies;
944 memcpy(nc_path->next_hop, dst, ETH_ALEN);
945 memcpy(nc_path->prev_hop, src, ETH_ALEN);
946
947 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",
948 nc_path->prev_hop,
949 nc_path->next_hop);
950
951 /* Add nc_path to hash table */
952 hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,
953 batadv_nc_hash_choose, &nc_path_key,
954 &nc_path->hash_entry);
955
956 if (hash_added < 0) {
957 kfree(nc_path);
958 return NULL;
959 }
960
961 return nc_path;
962}
963
964/**
Martin Hundebøll3c12de92013-01-25 11:12:41 +0100965 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
966 * selection of a receiver with slightly lower TQ than the other
967 * @tq: to be weighted tq value
968 */
969static uint8_t batadv_nc_random_weight_tq(uint8_t tq)
970{
971 uint8_t rand_val, rand_tq;
972
973 get_random_bytes(&rand_val, sizeof(rand_val));
974
975 /* randomize the estimated packet loss (max TQ - estimated TQ) */
976 rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
977
978 /* normalize the randomized packet loss */
979 rand_tq /= BATADV_TQ_MAX_VALUE;
980
981 /* convert to (randomized) estimated tq again */
982 return BATADV_TQ_MAX_VALUE - rand_tq;
983}
984
985/**
986 * batadv_nc_memxor - XOR destination with source
987 * @dst: byte array to XOR into
988 * @src: byte array to XOR from
989 * @len: length of destination array
990 */
991static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
992{
993 unsigned int i;
994
995 for (i = 0; i < len; ++i)
996 dst[i] ^= src[i];
997}
998
999/**
1000 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
1001 * into a coded_packet and send it
1002 * @bat_priv: the bat priv with all the soft interface information
1003 * @skb: data skb to forward
1004 * @ethhdr: pointer to the ethernet header inside the skb
1005 * @nc_packet: structure containing the packet to the skb can be coded with
1006 * @neigh_node: next hop to forward packet to
1007 *
1008 * Returns true if both packets are consumed, false otherwise.
1009 */
1010static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
1011 struct sk_buff *skb,
1012 struct ethhdr *ethhdr,
1013 struct batadv_nc_packet *nc_packet,
1014 struct batadv_neigh_node *neigh_node)
1015{
Antonio Quartulli0538f752013-09-02 12:15:01 +02001016 uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001017 struct sk_buff *skb_dest, *skb_src;
1018 struct batadv_unicast_packet *packet1;
1019 struct batadv_unicast_packet *packet2;
1020 struct batadv_coded_packet *coded_packet;
1021 struct batadv_neigh_node *neigh_tmp, *router_neigh;
1022 struct batadv_neigh_node *router_coding = NULL;
Simon Wunderlich89652332013-11-13 19:14:46 +01001023 struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL;
1024 struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001025 uint8_t *first_source, *first_dest, *second_source, *second_dest;
1026 __be32 packet_id1, packet_id2;
1027 size_t count;
1028 bool res = false;
1029 int coding_len;
1030 int unicast_size = sizeof(*packet1);
1031 int coded_size = sizeof(*coded_packet);
1032 int header_add = coded_size - unicast_size;
1033
Simon Wunderlich7351a4822013-11-13 19:14:47 +01001034 /* TODO: do we need to consider the outgoing interface for
1035 * coded packets?
1036 */
1037 router_neigh = batadv_orig_router_get(neigh_node->orig_node,
1038 BATADV_IF_DEFAULT);
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001039 if (!router_neigh)
1040 goto out;
1041
Simon Wunderlich89652332013-11-13 19:14:46 +01001042 router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh,
1043 BATADV_IF_DEFAULT);
1044 if (!router_neigh_ifinfo)
1045 goto out;
1046
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001047 neigh_tmp = nc_packet->neigh_node;
Simon Wunderlich7351a4822013-11-13 19:14:47 +01001048 router_coding = batadv_orig_router_get(neigh_tmp->orig_node,
1049 BATADV_IF_DEFAULT);
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001050 if (!router_coding)
1051 goto out;
1052
Simon Wunderlich89652332013-11-13 19:14:46 +01001053 router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding,
1054 BATADV_IF_DEFAULT);
1055 if (!router_coding_ifinfo)
1056 goto out;
1057
1058 tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg;
1059 tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp);
1060 tq_tmp = router_coding_ifinfo->bat_iv.tq_avg;
1061 tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp);
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001062
1063 /* Select one destination for the MAC-header dst-field based on
1064 * weighted TQ-values.
1065 */
1066 if (tq_weighted_neigh >= tq_weighted_coding) {
1067 /* Destination from nc_packet is selected for MAC-header */
1068 first_dest = nc_packet->nc_path->next_hop;
1069 first_source = nc_packet->nc_path->prev_hop;
1070 second_dest = neigh_node->addr;
1071 second_source = ethhdr->h_source;
1072 packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1073 packet2 = (struct batadv_unicast_packet *)skb->data;
1074 packet_id1 = nc_packet->packet_id;
1075 packet_id2 = batadv_skb_crc32(skb,
1076 skb->data + sizeof(*packet2));
1077 } else {
1078 /* Destination for skb is selected for MAC-header */
1079 first_dest = neigh_node->addr;
1080 first_source = ethhdr->h_source;
1081 second_dest = nc_packet->nc_path->next_hop;
1082 second_source = nc_packet->nc_path->prev_hop;
1083 packet1 = (struct batadv_unicast_packet *)skb->data;
1084 packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1085 packet_id1 = batadv_skb_crc32(skb,
1086 skb->data + sizeof(*packet1));
1087 packet_id2 = nc_packet->packet_id;
1088 }
1089
1090 /* Instead of zero padding the smallest data buffer, we
1091 * code into the largest.
1092 */
1093 if (skb->len <= nc_packet->skb->len) {
1094 skb_dest = nc_packet->skb;
1095 skb_src = skb;
1096 } else {
1097 skb_dest = skb;
1098 skb_src = nc_packet->skb;
1099 }
1100
1101 /* coding_len is used when decoding the packet shorter packet */
1102 coding_len = skb_src->len - unicast_size;
1103
1104 if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
1105 goto out;
1106
1107 skb_push(skb_dest, header_add);
1108
1109 coded_packet = (struct batadv_coded_packet *)skb_dest->data;
1110 skb_reset_mac_header(skb_dest);
1111
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001112 coded_packet->packet_type = BATADV_CODED;
1113 coded_packet->version = BATADV_COMPAT_VERSION;
1114 coded_packet->ttl = packet1->ttl;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001115
1116 /* Info about first unicast packet */
1117 memcpy(coded_packet->first_source, first_source, ETH_ALEN);
1118 memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN);
1119 coded_packet->first_crc = packet_id1;
1120 coded_packet->first_ttvn = packet1->ttvn;
1121
1122 /* Info about second unicast packet */
1123 memcpy(coded_packet->second_dest, second_dest, ETH_ALEN);
1124 memcpy(coded_packet->second_source, second_source, ETH_ALEN);
1125 memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN);
1126 coded_packet->second_crc = packet_id2;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001127 coded_packet->second_ttl = packet2->ttl;
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001128 coded_packet->second_ttvn = packet2->ttvn;
1129 coded_packet->coded_len = htons(coding_len);
1130
1131 /* This is where the magic happens: Code skb_src into skb_dest */
1132 batadv_nc_memxor(skb_dest->data + coded_size,
1133 skb_src->data + unicast_size, coding_len);
1134
1135 /* Update counters accordingly */
1136 if (BATADV_SKB_CB(skb_src)->decoded &&
1137 BATADV_SKB_CB(skb_dest)->decoded) {
1138 /* Both packets are recoded */
1139 count = skb_src->len + ETH_HLEN;
1140 count += skb_dest->len + ETH_HLEN;
1141 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
1142 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
1143 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1144 !BATADV_SKB_CB(skb_dest)->decoded) {
1145 /* Both packets are newly coded */
1146 count = skb_src->len + ETH_HLEN;
1147 count += skb_dest->len + ETH_HLEN;
1148 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
1149 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
1150 } else if (BATADV_SKB_CB(skb_src)->decoded &&
1151 !BATADV_SKB_CB(skb_dest)->decoded) {
1152 /* skb_src recoded and skb_dest is newly coded */
1153 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1154 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1155 skb_src->len + ETH_HLEN);
1156 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1157 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1158 skb_dest->len + ETH_HLEN);
1159 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1160 BATADV_SKB_CB(skb_dest)->decoded) {
1161 /* skb_src is newly coded and skb_dest is recoded */
1162 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1163 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1164 skb_src->len + ETH_HLEN);
1165 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1166 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1167 skb_dest->len + ETH_HLEN);
1168 }
1169
1170 /* skb_src is now coded into skb_dest, so free it */
1171 kfree_skb(skb_src);
1172
1173 /* avoid duplicate free of skb from nc_packet */
1174 nc_packet->skb = NULL;
1175 batadv_nc_packet_free(nc_packet);
1176
1177 /* Send the coded packet and return true */
1178 batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
1179 res = true;
1180out:
1181 if (router_neigh)
1182 batadv_neigh_node_free_ref(router_neigh);
1183 if (router_coding)
1184 batadv_neigh_node_free_ref(router_coding);
Simon Wunderlich89652332013-11-13 19:14:46 +01001185 if (router_neigh_ifinfo)
1186 batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo);
1187 if (router_coding_ifinfo)
1188 batadv_neigh_ifinfo_free_ref(router_coding_ifinfo);
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001189 return res;
1190}
1191
1192/**
1193 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1194 * @skb: data skb to forward
1195 * @dst: destination mac address of the other skb to code with
1196 * @src: source mac address of skb
1197 *
1198 * Whenever we network code a packet we have to check whether we received it in
1199 * a network coded form. If so, we may not be able to use it for coding because
1200 * some neighbors may also have received (overheard) the packet in the network
1201 * coded form without being able to decode it. It is hard to know which of the
1202 * neighboring nodes was able to decode the packet, therefore we can only
1203 * re-code the packet if the source of the previous encoded packet is involved.
1204 * Since the source encoded the packet we can be certain it has all necessary
1205 * decode information.
1206 *
1207 * Returns true if coding of a decoded packet is allowed.
1208 */
1209static bool batadv_nc_skb_coding_possible(struct sk_buff *skb,
1210 uint8_t *dst, uint8_t *src)
1211{
1212 if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
1213 return false;
1214 else
1215 return true;
1216}
1217
1218/**
1219 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1220 * out_nc_node to retrieve a buffered packet that can be used for coding.
1221 * @bat_priv: the bat priv with all the soft interface information
1222 * @in_nc_node: pointer to skb next hop's neighbor nc node
1223 * @out_nc_node: pointer to skb source's neighbor nc node
1224 * @skb: data skb to forward
1225 * @eth_dst: next hop mac address of skb
1226 *
1227 * Returns true if coding of a decoded skb is allowed.
1228 */
1229static struct batadv_nc_packet *
1230batadv_nc_path_search(struct batadv_priv *bat_priv,
1231 struct batadv_nc_node *in_nc_node,
1232 struct batadv_nc_node *out_nc_node,
1233 struct sk_buff *skb,
1234 uint8_t *eth_dst)
1235{
1236 struct batadv_nc_path *nc_path, nc_path_key;
1237 struct batadv_nc_packet *nc_packet_out = NULL;
1238 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
1239 struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
1240 int idx;
1241
1242 if (!hash)
1243 return NULL;
1244
1245 /* Create almost path key */
1246 batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
1247 out_nc_node->addr);
1248 idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
1249
1250 /* Check for coding opportunities in this nc_path */
1251 rcu_read_lock();
1252 hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
1253 if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
1254 continue;
1255
1256 if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
1257 continue;
1258
1259 spin_lock_bh(&nc_path->packet_list_lock);
1260 if (list_empty(&nc_path->packet_list)) {
1261 spin_unlock_bh(&nc_path->packet_list_lock);
1262 continue;
1263 }
1264
1265 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
1266 &nc_path->packet_list, list) {
1267 if (!batadv_nc_skb_coding_possible(nc_packet->skb,
1268 eth_dst,
1269 in_nc_node->addr))
1270 continue;
1271
1272 /* Coding opportunity is found! */
1273 list_del(&nc_packet->list);
1274 nc_packet_out = nc_packet;
1275 break;
1276 }
1277
1278 spin_unlock_bh(&nc_path->packet_list_lock);
1279 break;
1280 }
1281 rcu_read_unlock();
1282
1283 return nc_packet_out;
1284}
1285
1286/**
1287 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1288 * skb's sender (may be equal to the originator).
1289 * @bat_priv: the bat priv with all the soft interface information
1290 * @skb: data skb to forward
1291 * @eth_dst: next hop mac address of skb
1292 * @eth_src: source mac address of skb
1293 * @in_nc_node: pointer to skb next hop's neighbor nc node
1294 *
1295 * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
1296 */
1297static struct batadv_nc_packet *
1298batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
1299 struct sk_buff *skb,
1300 uint8_t *eth_dst,
1301 uint8_t *eth_src,
1302 struct batadv_nc_node *in_nc_node)
1303{
1304 struct batadv_orig_node *orig_node;
1305 struct batadv_nc_node *out_nc_node;
1306 struct batadv_nc_packet *nc_packet = NULL;
1307
1308 orig_node = batadv_orig_hash_find(bat_priv, eth_src);
1309 if (!orig_node)
1310 return NULL;
1311
1312 rcu_read_lock();
1313 list_for_each_entry_rcu(out_nc_node,
1314 &orig_node->out_coding_list, list) {
1315 /* Check if the skb is decoded and if recoding is possible */
1316 if (!batadv_nc_skb_coding_possible(skb,
1317 out_nc_node->addr, eth_src))
1318 continue;
1319
1320 /* Search for an opportunity in this nc_path */
1321 nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
1322 out_nc_node, skb, eth_dst);
1323 if (nc_packet)
1324 break;
1325 }
1326 rcu_read_unlock();
1327
1328 batadv_orig_node_free_ref(orig_node);
1329 return nc_packet;
1330}
1331
1332/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001333 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1334 * unicast skb before it is stored for use in later decoding
1335 * @bat_priv: the bat priv with all the soft interface information
1336 * @skb: data skb to store
1337 * @eth_dst_new: new destination mac address of skb
1338 */
1339static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
1340 struct sk_buff *skb,
1341 uint8_t *eth_dst_new)
1342{
1343 struct ethhdr *ethhdr;
1344
1345 /* Copy skb header to change the mac header */
1346 skb = pskb_copy(skb, GFP_ATOMIC);
1347 if (!skb)
1348 return;
1349
1350 /* Set the mac header as if we actually sent the packet uncoded */
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001351 ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001352 memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN);
1353 memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN);
1354
1355 /* Set data pointer to MAC header to mimic packets from our tx path */
1356 skb_push(skb, ETH_HLEN);
1357
1358 /* Add the packet to the decoding packet pool */
1359 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1360
1361 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1362 * our ref
1363 */
1364 kfree_skb(skb);
1365}
1366
1367/**
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001368 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1369 * @skb: data skb to forward
1370 * @neigh_node: next hop to forward packet to
1371 * @ethhdr: pointer to the ethernet header inside the skb
1372 *
1373 * Loops through list of neighboring nodes the next hop has a good connection to
1374 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1375 * next hop that potentially sent a packet which our next hop also received
1376 * (overheard) and has stored for later decoding.
1377 *
1378 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1379 */
1380static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
1381 struct batadv_neigh_node *neigh_node,
1382 struct ethhdr *ethhdr)
1383{
1384 struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1385 struct batadv_priv *bat_priv = netdev_priv(netdev);
1386 struct batadv_orig_node *orig_node = neigh_node->orig_node;
1387 struct batadv_nc_node *nc_node;
1388 struct batadv_nc_packet *nc_packet = NULL;
1389
1390 rcu_read_lock();
1391 list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
1392 /* Search for coding opportunity with this in_nc_node */
1393 nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
1394 neigh_node->addr,
1395 ethhdr->h_source, nc_node);
1396
1397 /* Opportunity was found, so stop searching */
1398 if (nc_packet)
1399 break;
1400 }
1401 rcu_read_unlock();
1402
1403 if (!nc_packet)
1404 return false;
1405
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001406 /* Save packets for later decoding */
1407 batadv_nc_skb_store_before_coding(bat_priv, skb,
1408 neigh_node->addr);
1409 batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
1410 nc_packet->neigh_node->addr);
1411
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001412 /* Code and send packets */
1413 if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
1414 neigh_node))
1415 return true;
1416
1417 /* out of mem ? Coding failed - we have to free the buffered packet
1418 * to avoid memleaks. The skb passed as argument will be dealt with
1419 * by the calling function.
1420 */
1421 batadv_nc_send_packet(nc_packet);
1422 return false;
1423}
1424
1425/**
Martin Hundebøll95332472013-01-25 11:12:40 +01001426 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1427 * @skb: skb to add to path
1428 * @nc_path: path to add skb to
1429 * @neigh_node: next hop to forward packet to
1430 * @packet_id: checksum to identify packet
1431 *
1432 * Returns true if the packet was buffered or false in case of an error.
1433 */
1434static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,
1435 struct batadv_nc_path *nc_path,
1436 struct batadv_neigh_node *neigh_node,
1437 __be32 packet_id)
1438{
1439 struct batadv_nc_packet *nc_packet;
1440
1441 nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
1442 if (!nc_packet)
1443 return false;
1444
1445 /* Initialize nc_packet */
1446 nc_packet->timestamp = jiffies;
1447 nc_packet->packet_id = packet_id;
1448 nc_packet->skb = skb;
1449 nc_packet->neigh_node = neigh_node;
1450 nc_packet->nc_path = nc_path;
1451
1452 /* Add coding packet to list */
1453 spin_lock_bh(&nc_path->packet_list_lock);
1454 list_add_tail(&nc_packet->list, &nc_path->packet_list);
1455 spin_unlock_bh(&nc_path->packet_list_lock);
1456
1457 return true;
1458}
1459
1460/**
1461 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1462 * buffer
1463 * @skb: data skb to forward
1464 * @neigh_node: next hop to forward packet to
Martin Hundebøll95332472013-01-25 11:12:40 +01001465 *
1466 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1467 */
1468bool batadv_nc_skb_forward(struct sk_buff *skb,
Martin Hundebølle91ecfc2013-04-20 13:54:39 +02001469 struct batadv_neigh_node *neigh_node)
Martin Hundebøll95332472013-01-25 11:12:40 +01001470{
1471 const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1472 struct batadv_priv *bat_priv = netdev_priv(netdev);
1473 struct batadv_unicast_packet *packet;
1474 struct batadv_nc_path *nc_path;
Martin Hundebølle91ecfc2013-04-20 13:54:39 +02001475 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll95332472013-01-25 11:12:40 +01001476 __be32 packet_id;
1477 u8 *payload;
1478
1479 /* Check if network coding is enabled */
1480 if (!atomic_read(&bat_priv->network_coding))
1481 goto out;
1482
1483 /* We only handle unicast packets */
1484 payload = skb_network_header(skb);
1485 packet = (struct batadv_unicast_packet *)payload;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001486 if (packet->packet_type != BATADV_UNICAST)
Martin Hundebøll95332472013-01-25 11:12:40 +01001487 goto out;
1488
Martin Hundebøll3c12de92013-01-25 11:12:41 +01001489 /* Try to find a coding opportunity and send the skb if one is found */
1490 if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
1491 return true;
1492
Martin Hundebøll95332472013-01-25 11:12:40 +01001493 /* Find or create a nc_path for this src-dst pair */
1494 nc_path = batadv_nc_get_path(bat_priv,
1495 bat_priv->nc.coding_hash,
1496 ethhdr->h_source,
1497 neigh_node->addr);
1498
1499 if (!nc_path)
1500 goto out;
1501
1502 /* Add skb to nc_path */
1503 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1504 if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))
1505 goto free_nc_path;
1506
1507 /* Packet is consumed */
1508 return true;
1509
1510free_nc_path:
1511 batadv_nc_path_free_ref(nc_path);
1512out:
1513 /* Packet is not consumed */
1514 return false;
1515}
1516
1517/**
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001518 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1519 * when decoding coded packets
1520 * @bat_priv: the bat priv with all the soft interface information
1521 * @skb: data skb to store
1522 */
1523void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
1524 struct sk_buff *skb)
1525{
1526 struct batadv_unicast_packet *packet;
1527 struct batadv_nc_path *nc_path;
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001528 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001529 __be32 packet_id;
1530 u8 *payload;
1531
1532 /* Check if network coding is enabled */
1533 if (!atomic_read(&bat_priv->network_coding))
1534 goto out;
1535
1536 /* Check for supported packet type */
1537 payload = skb_network_header(skb);
1538 packet = (struct batadv_unicast_packet *)payload;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001539 if (packet->packet_type != BATADV_UNICAST)
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001540 goto out;
1541
1542 /* Find existing nc_path or create a new */
1543 nc_path = batadv_nc_get_path(bat_priv,
1544 bat_priv->nc.decoding_hash,
1545 ethhdr->h_source,
1546 ethhdr->h_dest);
1547
1548 if (!nc_path)
1549 goto out;
1550
1551 /* Clone skb and adjust skb->data to point at batman header */
1552 skb = skb_clone(skb, GFP_ATOMIC);
1553 if (unlikely(!skb))
1554 goto free_nc_path;
1555
1556 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
1557 goto free_skb;
1558
1559 if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
1560 goto free_skb;
1561
1562 /* Add skb to nc_path */
1563 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1564 if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
1565 goto free_skb;
1566
1567 batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
1568 return;
1569
1570free_skb:
1571 kfree_skb(skb);
1572free_nc_path:
1573 batadv_nc_path_free_ref(nc_path);
1574out:
1575 return;
1576}
1577
1578/**
1579 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1580 * should be saved in the decoding buffer and, if so, store it there
1581 * @bat_priv: the bat priv with all the soft interface information
1582 * @skb: unicast skb to store
1583 */
1584void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
1585 struct sk_buff *skb)
1586{
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001587 struct ethhdr *ethhdr = eth_hdr(skb);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001588
David S. Miller6e0895c2013-04-22 20:32:51 -04001589 if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001590 return;
1591
1592 /* Set data pointer to MAC header to mimic packets from our tx path */
1593 skb_push(skb, ETH_HLEN);
1594
1595 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1596}
1597
1598/**
Martin Hundebøll2df52782013-01-25 11:12:43 +01001599 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1600 * in nc_packet
David S. Miller6e0895c2013-04-22 20:32:51 -04001601 * @bat_priv: the bat priv with all the soft interface information
Martin Hundebøll2df52782013-01-25 11:12:43 +01001602 * @skb: unicast skb to decode
1603 * @nc_packet: decode data needed to decode the skb
1604 *
1605 * Returns pointer to decoded unicast packet if the packet was decoded or NULL
1606 * in case of an error.
1607 */
1608static struct batadv_unicast_packet *
David S. Miller6e0895c2013-04-22 20:32:51 -04001609batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
Martin Hundebøll2df52782013-01-25 11:12:43 +01001610 struct batadv_nc_packet *nc_packet)
1611{
1612 const int h_size = sizeof(struct batadv_unicast_packet);
1613 const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
1614 struct batadv_unicast_packet *unicast_packet;
1615 struct batadv_coded_packet coded_packet_tmp;
1616 struct ethhdr *ethhdr, ethhdr_tmp;
1617 uint8_t *orig_dest, ttl, ttvn;
1618 unsigned int coding_len;
Marek Lindner7da19972013-05-07 19:25:02 +08001619 int err;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001620
1621 /* Save headers temporarily */
1622 memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
1623 memcpy(&ethhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
1624
1625 if (skb_cow(skb, 0) < 0)
1626 return NULL;
1627
1628 if (unlikely(!skb_pull_rcsum(skb, h_diff)))
1629 return NULL;
1630
1631 /* Data points to batman header, so set mac header 14 bytes before
1632 * and network to data
1633 */
1634 skb_set_mac_header(skb, -ETH_HLEN);
1635 skb_reset_network_header(skb);
1636
1637 /* Reconstruct original mac header */
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001638 ethhdr = eth_hdr(skb);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001639 memcpy(ethhdr, &ethhdr_tmp, sizeof(*ethhdr));
1640
1641 /* Select the correct unicast header information based on the location
1642 * of our mac address in the coded_packet header
1643 */
David S. Miller6e0895c2013-04-22 20:32:51 -04001644 if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
Martin Hundebøll2df52782013-01-25 11:12:43 +01001645 /* If we are the second destination the packet was overheard,
1646 * so the Ethernet address must be copied to h_dest and
1647 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1648 */
1649 memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN);
1650 skb->pkt_type = PACKET_HOST;
1651
1652 orig_dest = coded_packet_tmp.second_orig_dest;
1653 ttl = coded_packet_tmp.second_ttl;
1654 ttvn = coded_packet_tmp.second_ttvn;
1655 } else {
1656 orig_dest = coded_packet_tmp.first_orig_dest;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001657 ttl = coded_packet_tmp.ttl;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001658 ttvn = coded_packet_tmp.first_ttvn;
1659 }
1660
1661 coding_len = ntohs(coded_packet_tmp.coded_len);
1662
1663 if (coding_len > skb->len)
1664 return NULL;
1665
1666 /* Here the magic is reversed:
1667 * extract the missing packet from the received coded packet
1668 */
1669 batadv_nc_memxor(skb->data + h_size,
1670 nc_packet->skb->data + h_size,
1671 coding_len);
1672
1673 /* Resize decoded skb if decoded with larger packet */
Marek Lindner7da19972013-05-07 19:25:02 +08001674 if (nc_packet->skb->len > coding_len + h_size) {
1675 err = pskb_trim_rcsum(skb, coding_len + h_size);
1676 if (err)
1677 return NULL;
1678 }
Martin Hundebøll2df52782013-01-25 11:12:43 +01001679
1680 /* Create decoded unicast packet */
1681 unicast_packet = (struct batadv_unicast_packet *)skb->data;
Simon Wunderlicha40d9b02013-12-02 20:38:31 +01001682 unicast_packet->packet_type = BATADV_UNICAST;
1683 unicast_packet->version = BATADV_COMPAT_VERSION;
1684 unicast_packet->ttl = ttl;
Martin Hundebøll2df52782013-01-25 11:12:43 +01001685 memcpy(unicast_packet->dest, orig_dest, ETH_ALEN);
1686 unicast_packet->ttvn = ttvn;
1687
1688 batadv_nc_packet_free(nc_packet);
1689 return unicast_packet;
1690}
1691
1692/**
1693 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1694 * find the data needed to decode the coded packet
1695 * @bat_priv: the bat priv with all the soft interface information
1696 * @ethhdr: pointer to the ethernet header inside the coded packet
1697 * @coded: coded packet we try to find decode data for
1698 *
1699 * Returns pointer to nc packet if the needed data was found or NULL otherwise.
1700 */
1701static struct batadv_nc_packet *
1702batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
1703 struct ethhdr *ethhdr,
1704 struct batadv_coded_packet *coded)
1705{
1706 struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
1707 struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
1708 struct batadv_nc_path *nc_path, nc_path_key;
1709 uint8_t *dest, *source;
1710 __be32 packet_id;
1711 int index;
1712
1713 if (!hash)
1714 return NULL;
1715
1716 /* Select the correct packet id based on the location of our mac-addr */
1717 dest = ethhdr->h_source;
David S. Miller6e0895c2013-04-22 20:32:51 -04001718 if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
Martin Hundebøll2df52782013-01-25 11:12:43 +01001719 source = coded->second_source;
1720 packet_id = coded->second_crc;
1721 } else {
1722 source = coded->first_source;
1723 packet_id = coded->first_crc;
1724 }
1725
1726 batadv_nc_hash_key_gen(&nc_path_key, source, dest);
1727 index = batadv_nc_hash_choose(&nc_path_key, hash->size);
1728
1729 /* Search for matching coding path */
1730 rcu_read_lock();
1731 hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
1732 /* Find matching nc_packet */
1733 spin_lock_bh(&nc_path->packet_list_lock);
1734 list_for_each_entry(tmp_nc_packet,
1735 &nc_path->packet_list, list) {
1736 if (packet_id == tmp_nc_packet->packet_id) {
1737 list_del(&tmp_nc_packet->list);
1738
1739 nc_packet = tmp_nc_packet;
1740 break;
1741 }
1742 }
1743 spin_unlock_bh(&nc_path->packet_list_lock);
1744
1745 if (nc_packet)
1746 break;
1747 }
1748 rcu_read_unlock();
1749
1750 if (!nc_packet)
1751 batadv_dbg(BATADV_DBG_NC, bat_priv,
1752 "No decoding packet found for %u\n", packet_id);
1753
1754 return nc_packet;
1755}
1756
1757/**
1758 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1759 * resulting unicast packet
1760 * @skb: incoming coded packet
1761 * @recv_if: pointer to interface this packet was received on
1762 */
1763static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
1764 struct batadv_hard_iface *recv_if)
1765{
1766 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1767 struct batadv_unicast_packet *unicast_packet;
1768 struct batadv_coded_packet *coded_packet;
1769 struct batadv_nc_packet *nc_packet;
1770 struct ethhdr *ethhdr;
1771 int hdr_size = sizeof(*coded_packet);
1772
1773 /* Check if network coding is enabled */
1774 if (!atomic_read(&bat_priv->network_coding))
1775 return NET_RX_DROP;
1776
1777 /* Make sure we can access (and remove) header */
1778 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1779 return NET_RX_DROP;
1780
1781 coded_packet = (struct batadv_coded_packet *)skb->data;
Antonio Quartulli7ed4be92013-04-08 15:08:18 +02001782 ethhdr = eth_hdr(skb);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001783
1784 /* Verify frame is destined for us */
David S. Miller6e0895c2013-04-22 20:32:51 -04001785 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
1786 !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
Martin Hundebøll2df52782013-01-25 11:12:43 +01001787 return NET_RX_DROP;
1788
1789 /* Update stat counter */
David S. Miller6e0895c2013-04-22 20:32:51 -04001790 if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
Martin Hundebøll2df52782013-01-25 11:12:43 +01001791 batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
1792
1793 nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
1794 coded_packet);
1795 if (!nc_packet) {
1796 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1797 return NET_RX_DROP;
1798 }
1799
1800 /* Make skb's linear, because decoding accesses the entire buffer */
1801 if (skb_linearize(skb) < 0)
1802 goto free_nc_packet;
1803
1804 if (skb_linearize(nc_packet->skb) < 0)
1805 goto free_nc_packet;
1806
1807 /* Decode the packet */
David S. Miller6e0895c2013-04-22 20:32:51 -04001808 unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
Martin Hundebøll2df52782013-01-25 11:12:43 +01001809 if (!unicast_packet) {
1810 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1811 goto free_nc_packet;
1812 }
1813
1814 /* Mark packet as decoded to do correct recoding when forwarding */
1815 BATADV_SKB_CB(skb)->decoded = true;
1816 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
1817 batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
1818 skb->len + ETH_HLEN);
1819 return batadv_recv_unicast_packet(skb, recv_if);
1820
1821free_nc_packet:
1822 batadv_nc_packet_free(nc_packet);
1823 return NET_RX_DROP;
1824}
1825
1826/**
Matthias Schiffer6c519ba2013-09-27 18:03:39 +02001827 * batadv_nc_mesh_free - clean up network coding memory
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001828 * @bat_priv: the bat priv with all the soft interface information
1829 */
Matthias Schiffer6c519ba2013-09-27 18:03:39 +02001830void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001831{
Marek Lindner3f4841f2013-04-23 21:40:00 +08001832 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
1833 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1);
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001834 cancel_delayed_work_sync(&bat_priv->nc.work);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001835
Martin Hundebøll95332472013-01-25 11:12:40 +01001836 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
1837 batadv_hash_destroy(bat_priv->nc.coding_hash);
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001838 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
1839 batadv_hash_destroy(bat_priv->nc.decoding_hash);
Martin Hundebølld353d8d2013-01-25 11:12:38 +01001840}
Martin Hundebølld56b1702013-01-25 11:12:39 +01001841
1842/**
1843 * batadv_nc_nodes_seq_print_text - print the nc node information
1844 * @seq: seq file to print on
1845 * @offset: not used
1846 */
1847int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
1848{
1849 struct net_device *net_dev = (struct net_device *)seq->private;
1850 struct batadv_priv *bat_priv = netdev_priv(net_dev);
1851 struct batadv_hashtable *hash = bat_priv->orig_hash;
1852 struct batadv_hard_iface *primary_if;
1853 struct hlist_head *head;
1854 struct batadv_orig_node *orig_node;
1855 struct batadv_nc_node *nc_node;
1856 int i;
1857
1858 primary_if = batadv_seq_print_text_primary_if_get(seq);
1859 if (!primary_if)
1860 goto out;
1861
1862 /* Traverse list of originators */
1863 for (i = 0; i < hash->size; i++) {
1864 head = &hash->table[i];
1865
1866 /* For each orig_node in this bin */
1867 rcu_read_lock();
1868 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindneraa27c3122013-04-18 04:56:03 +08001869 /* no need to print the orig node if it does not have
1870 * network coding neighbors
1871 */
1872 if (list_empty(&orig_node->in_coding_list) &&
1873 list_empty(&orig_node->out_coding_list))
1874 continue;
1875
Martin Hundebølld56b1702013-01-25 11:12:39 +01001876 seq_printf(seq, "Node: %pM\n", orig_node->orig);
1877
Antonio Quartulli0c814652013-03-21 09:23:29 +01001878 seq_puts(seq, " Ingoing: ");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001879 /* For each in_nc_node to this orig_node */
1880 list_for_each_entry_rcu(nc_node,
1881 &orig_node->in_coding_list,
1882 list)
1883 seq_printf(seq, "%pM ",
1884 nc_node->addr);
Antonio Quartulli0c814652013-03-21 09:23:29 +01001885 seq_puts(seq, "\n");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001886
Antonio Quartulli0c814652013-03-21 09:23:29 +01001887 seq_puts(seq, " Outgoing: ");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001888 /* For out_nc_node to this orig_node */
1889 list_for_each_entry_rcu(nc_node,
1890 &orig_node->out_coding_list,
1891 list)
1892 seq_printf(seq, "%pM ",
1893 nc_node->addr);
Antonio Quartulli0c814652013-03-21 09:23:29 +01001894 seq_puts(seq, "\n\n");
Martin Hundebølld56b1702013-01-25 11:12:39 +01001895 }
1896 rcu_read_unlock();
1897 }
1898
1899out:
1900 if (primary_if)
1901 batadv_hardif_free_ref(primary_if);
1902 return 0;
1903}
1904
1905/**
1906 * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1907 * @bat_priv: the bat priv with all the soft interface information
1908 */
1909int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
1910{
1911 struct dentry *nc_dir, *file;
1912
1913 nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
1914 if (!nc_dir)
1915 goto out;
1916
1917 file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
1918 &bat_priv->nc.min_tq);
1919 if (!file)
1920 goto out;
1921
Martin Hundebøll95332472013-01-25 11:12:40 +01001922 file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,
1923 &bat_priv->nc.max_fwd_delay);
1924 if (!file)
1925 goto out;
1926
Martin Hundebøll612d2b42013-01-25 11:12:42 +01001927 file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
1928 &bat_priv->nc.max_buffer_time);
1929 if (!file)
1930 goto out;
1931
Martin Hundebølld56b1702013-01-25 11:12:39 +01001932 return 0;
1933
1934out:
1935 return -ENOMEM;
1936}