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d353d8d4 MH |
1 | /* 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 | ||
d56b1705 MH |
20 | #include <linux/debugfs.h> |
21 | ||
d353d8d4 | 22 | #include "main.h" |
95332477 | 23 | #include "hash.h" |
d353d8d4 | 24 | #include "network-coding.h" |
95332477 | 25 | #include "send.h" |
d56b1705 MH |
26 | #include "originator.h" |
27 | #include "hard-interface.h" | |
2df5278b | 28 | #include "routing.h" |
d353d8d4 | 29 | |
95332477 | 30 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
612d2b4f | 31 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
95332477 | 32 | |
d353d8d4 | 33 | static void batadv_nc_worker(struct work_struct *work); |
2df5278b MH |
34 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
35 | struct batadv_hard_iface *recv_if); | |
d353d8d4 MH |
36 | |
37 | /** | |
38 | * batadv_nc_start_timer - initialise the nc periodic worker | |
39 | * @bat_priv: the bat priv with all the soft interface information | |
40 | */ | |
41 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
42 | { | |
43 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
44 | msecs_to_jiffies(10)); | |
45 | } | |
46 | ||
47 | /** | |
48 | * batadv_nc_init - initialise coding hash table and start house keeping | |
49 | * @bat_priv: the bat priv with all the soft interface information | |
50 | */ | |
51 | int batadv_nc_init(struct batadv_priv *bat_priv) | |
52 | { | |
95332477 | 53 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 54 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 55 | |
612d2b4f | 56 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
57 | return 0; |
58 | ||
59 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
60 | if (!bat_priv->nc.coding_hash) | |
61 | goto err; | |
62 | ||
63 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
64 | &batadv_nc_coding_hash_lock_class_key); | |
65 | ||
612d2b4f MH |
66 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
67 | if (!bat_priv->nc.decoding_hash) | |
68 | goto err; | |
69 | ||
70 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
71 | &batadv_nc_decoding_hash_lock_class_key); | |
72 | ||
2df5278b MH |
73 | /* Register our packet type */ |
74 | if (batadv_recv_handler_register(BATADV_CODED, | |
75 | batadv_nc_recv_coded_packet) < 0) | |
76 | goto err; | |
77 | ||
d353d8d4 MH |
78 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
79 | batadv_nc_start_timer(bat_priv); | |
80 | ||
81 | return 0; | |
95332477 MH |
82 | |
83 | err: | |
84 | return -ENOMEM; | |
d353d8d4 MH |
85 | } |
86 | ||
87 | /** | |
88 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables | |
89 | * @bat_priv: the bat priv with all the soft interface information | |
90 | */ | |
91 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
92 | { | |
93 | atomic_set(&bat_priv->network_coding, 1); | |
d56b1705 | 94 | bat_priv->nc.min_tq = 200; |
95332477 | 95 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 96 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
97 | } |
98 | ||
99 | /** | |
100 | * batadv_nc_init_orig - initialise the nc fields of an orig_node | |
101 | * @orig_node: the orig_node which is going to be initialised | |
102 | */ | |
103 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
104 | { | |
105 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
106 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
107 | spin_lock_init(&orig_node->in_coding_list_lock); | |
108 | spin_lock_init(&orig_node->out_coding_list_lock); | |
109 | } | |
110 | ||
111 | /** | |
112 | * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove | |
113 | * its refcount on the orig_node | |
114 | * @rcu: rcu pointer of the nc node | |
115 | */ | |
116 | static void batadv_nc_node_free_rcu(struct rcu_head *rcu) | |
117 | { | |
118 | struct batadv_nc_node *nc_node; | |
119 | ||
120 | nc_node = container_of(rcu, struct batadv_nc_node, rcu); | |
121 | batadv_orig_node_free_ref(nc_node->orig_node); | |
122 | kfree(nc_node); | |
123 | } | |
124 | ||
125 | /** | |
126 | * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly | |
127 | * frees it | |
128 | * @nc_node: the nc node to free | |
129 | */ | |
130 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) | |
131 | { | |
132 | if (atomic_dec_and_test(&nc_node->refcount)) | |
133 | call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu); | |
134 | } | |
135 | ||
95332477 MH |
136 | /** |
137 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly | |
138 | * frees it | |
139 | * @nc_path: the nc node to free | |
140 | */ | |
141 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) | |
142 | { | |
143 | if (atomic_dec_and_test(&nc_path->refcount)) | |
144 | kfree_rcu(nc_path, rcu); | |
145 | } | |
146 | ||
147 | /** | |
148 | * batadv_nc_packet_free - frees nc packet | |
149 | * @nc_packet: the nc packet to free | |
150 | */ | |
151 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) | |
152 | { | |
153 | if (nc_packet->skb) | |
154 | kfree_skb(nc_packet->skb); | |
155 | ||
156 | batadv_nc_path_free_ref(nc_packet->nc_path); | |
157 | kfree(nc_packet); | |
158 | } | |
159 | ||
d56b1705 MH |
160 | /** |
161 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged | |
162 | * @bat_priv: the bat priv with all the soft interface information | |
163 | * @nc_node: the nc node to check | |
164 | * | |
165 | * Returns true if the entry has to be purged now, false otherwise | |
166 | */ | |
167 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
168 | struct batadv_nc_node *nc_node) | |
169 | { | |
170 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
171 | return true; | |
172 | ||
173 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
174 | } | |
175 | ||
95332477 MH |
176 | /** |
177 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out | |
178 | * @bat_priv: the bat priv with all the soft interface information | |
179 | * @nc_path: the nc path to check | |
180 | * | |
181 | * Returns true if the entry has to be purged now, false otherwise | |
182 | */ | |
183 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
184 | struct batadv_nc_path *nc_path) | |
185 | { | |
186 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
187 | return true; | |
188 | ||
189 | /* purge the path when no packets has been added for 10 times the | |
190 | * max_fwd_delay time | |
191 | */ | |
192 | return batadv_has_timed_out(nc_path->last_valid, | |
193 | bat_priv->nc.max_fwd_delay * 10); | |
194 | } | |
195 | ||
612d2b4f MH |
196 | /** |
197 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out | |
198 | * @bat_priv: the bat priv with all the soft interface information | |
199 | * @nc_path: the nc path to check | |
200 | * | |
201 | * Returns true if the entry has to be purged now, false otherwise | |
202 | */ | |
203 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
204 | struct batadv_nc_path *nc_path) | |
205 | { | |
206 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
207 | return true; | |
208 | ||
209 | /* purge the path when no packets has been added for 10 times the | |
210 | * max_buffer time | |
211 | */ | |
212 | return batadv_has_timed_out(nc_path->last_valid, | |
213 | bat_priv->nc.max_buffer_time*10); | |
214 | } | |
215 | ||
d56b1705 MH |
216 | /** |
217 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale | |
218 | * entries | |
219 | * @bat_priv: the bat priv with all the soft interface information | |
220 | * @list: list of nc nodes | |
221 | * @lock: nc node list lock | |
222 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
223 | * not. This function takes the nc node as argument and has to return | |
224 | * a boolean value: true if the entry has to be deleted, false | |
225 | * otherwise | |
226 | */ | |
227 | static void | |
228 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
229 | struct list_head *list, | |
230 | spinlock_t *lock, | |
231 | bool (*to_purge)(struct batadv_priv *, | |
232 | struct batadv_nc_node *)) | |
233 | { | |
234 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
235 | ||
236 | /* For each nc_node in list */ | |
237 | spin_lock_bh(lock); | |
238 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
239 | /* if an helper function has been passed as parameter, | |
240 | * ask it if the entry has to be purged or not | |
241 | */ | |
242 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
243 | continue; | |
244 | ||
245 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
246 | "Removing nc_node %pM -> %pM\n", | |
247 | nc_node->addr, nc_node->orig_node->orig); | |
248 | list_del_rcu(&nc_node->list); | |
249 | batadv_nc_node_free_ref(nc_node); | |
250 | } | |
251 | spin_unlock_bh(lock); | |
252 | } | |
253 | ||
254 | /** | |
255 | * batadv_nc_purge_orig - purges all nc node data attached of the given | |
256 | * originator | |
257 | * @bat_priv: the bat priv with all the soft interface information | |
258 | * @orig_node: orig_node with the nc node entries to be purged | |
259 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
260 | * not. This function takes the nc node as argument and has to return | |
261 | * a boolean value: true is the entry has to be deleted, false | |
262 | * otherwise | |
263 | */ | |
264 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
265 | struct batadv_orig_node *orig_node, | |
266 | bool (*to_purge)(struct batadv_priv *, | |
267 | struct batadv_nc_node *)) | |
268 | { | |
269 | /* Check ingoing nc_node's of this orig_node */ | |
270 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
271 | &orig_node->in_coding_list_lock, | |
272 | to_purge); | |
273 | ||
274 | /* Check outgoing nc_node's of this orig_node */ | |
275 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
276 | &orig_node->out_coding_list_lock, | |
277 | to_purge); | |
278 | } | |
279 | ||
280 | /** | |
281 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they | |
282 | * have timed out nc nodes | |
283 | * @bat_priv: the bat priv with all the soft interface information | |
284 | */ | |
285 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
286 | { | |
287 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
288 | struct hlist_head *head; | |
289 | struct batadv_orig_node *orig_node; | |
290 | uint32_t i; | |
291 | ||
292 | if (!hash) | |
293 | return; | |
294 | ||
295 | /* For each orig_node */ | |
296 | for (i = 0; i < hash->size; i++) { | |
297 | head = &hash->table[i]; | |
298 | ||
299 | rcu_read_lock(); | |
300 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
301 | batadv_nc_purge_orig(bat_priv, orig_node, | |
302 | batadv_nc_to_purge_nc_node); | |
303 | rcu_read_unlock(); | |
304 | } | |
d353d8d4 MH |
305 | } |
306 | ||
95332477 MH |
307 | /** |
308 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove | |
309 | * unused ones | |
310 | * @bat_priv: the bat priv with all the soft interface information | |
311 | * @hash: hash table containing the nc paths to check | |
312 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
313 | * not. This function takes the nc node as argument and has to return | |
314 | * a boolean value: true is the entry has to be deleted, false | |
315 | * otherwise | |
316 | */ | |
317 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
318 | struct batadv_hashtable *hash, | |
319 | bool (*to_purge)(struct batadv_priv *, | |
320 | struct batadv_nc_path *)) | |
321 | { | |
322 | struct hlist_head *head; | |
323 | struct hlist_node *node_tmp; | |
324 | struct batadv_nc_path *nc_path; | |
325 | spinlock_t *lock; /* Protects lists in hash */ | |
326 | uint32_t i; | |
327 | ||
328 | for (i = 0; i < hash->size; i++) { | |
329 | head = &hash->table[i]; | |
330 | lock = &hash->list_locks[i]; | |
331 | ||
332 | /* For each nc_path in this bin */ | |
333 | spin_lock_bh(lock); | |
334 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
335 | /* if an helper function has been passed as parameter, | |
336 | * ask it if the entry has to be purged or not | |
337 | */ | |
338 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
339 | continue; | |
340 | ||
341 | /* purging an non-empty nc_path should never happen, but | |
342 | * is observed under high CPU load. Delay the purging | |
343 | * until next iteration to allow the packet_list to be | |
344 | * emptied first. | |
345 | */ | |
346 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
347 | net_ratelimited_function(printk, | |
348 | KERN_WARNING | |
349 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
350 | nc_path->prev_hop, | |
351 | nc_path->next_hop); | |
352 | continue; | |
353 | } | |
354 | ||
355 | /* nc_path is unused, so remove it */ | |
356 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
357 | "Remove nc_path %pM -> %pM\n", | |
358 | nc_path->prev_hop, nc_path->next_hop); | |
359 | hlist_del_rcu(&nc_path->hash_entry); | |
360 | batadv_nc_path_free_ref(nc_path); | |
361 | } | |
362 | spin_unlock_bh(lock); | |
363 | } | |
364 | } | |
365 | ||
366 | /** | |
367 | * batadv_nc_hash_key_gen - computes the nc_path hash key | |
368 | * @key: buffer to hold the final hash key | |
369 | * @src: source ethernet mac address going into the hash key | |
370 | * @dst: destination ethernet mac address going into the hash key | |
371 | */ | |
372 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
373 | const char *dst) | |
374 | { | |
375 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
376 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
377 | } | |
378 | ||
379 | /** | |
380 | * batadv_nc_hash_choose - compute the hash value for an nc path | |
381 | * @data: data to hash | |
382 | * @size: size of the hash table | |
383 | * | |
384 | * Returns the selected index in the hash table for the given data. | |
385 | */ | |
386 | static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) | |
387 | { | |
388 | const struct batadv_nc_path *nc_path = data; | |
389 | uint32_t hash = 0; | |
390 | ||
391 | hash = batadv_hash_bytes(hash, &nc_path->prev_hop, | |
392 | sizeof(nc_path->prev_hop)); | |
393 | hash = batadv_hash_bytes(hash, &nc_path->next_hop, | |
394 | sizeof(nc_path->next_hop)); | |
395 | ||
396 | hash += (hash << 3); | |
397 | hash ^= (hash >> 11); | |
398 | hash += (hash << 15); | |
399 | ||
400 | return hash % size; | |
401 | } | |
402 | ||
403 | /** | |
404 | * batadv_nc_hash_compare - comparing function used in the network coding hash | |
405 | * tables | |
406 | * @node: node in the local table | |
407 | * @data2: second object to compare the node to | |
408 | * | |
409 | * Returns 1 if the two entry are the same, 0 otherwise | |
410 | */ | |
411 | static int batadv_nc_hash_compare(const struct hlist_node *node, | |
412 | const void *data2) | |
413 | { | |
414 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
415 | ||
416 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
417 | nc_path2 = data2; | |
418 | ||
419 | /* Return 1 if the two keys are identical */ | |
420 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, | |
421 | sizeof(nc_path1->prev_hop)) != 0) | |
422 | return 0; | |
423 | ||
424 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, | |
425 | sizeof(nc_path1->next_hop)) != 0) | |
426 | return 0; | |
427 | ||
428 | return 1; | |
429 | } | |
430 | ||
431 | /** | |
432 | * batadv_nc_hash_find - search for an existing nc path and return it | |
433 | * @hash: hash table containing the nc path | |
434 | * @data: search key | |
435 | * | |
436 | * Returns the nc_path if found, NULL otherwise. | |
437 | */ | |
438 | static struct batadv_nc_path * | |
439 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
440 | void *data) | |
441 | { | |
442 | struct hlist_head *head; | |
443 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
444 | int index; | |
445 | ||
446 | if (!hash) | |
447 | return NULL; | |
448 | ||
449 | index = batadv_nc_hash_choose(data, hash->size); | |
450 | head = &hash->table[index]; | |
451 | ||
452 | rcu_read_lock(); | |
453 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
454 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
455 | continue; | |
456 | ||
457 | if (!atomic_inc_not_zero(&nc_path->refcount)) | |
458 | continue; | |
459 | ||
460 | nc_path_tmp = nc_path; | |
461 | break; | |
462 | } | |
463 | rcu_read_unlock(); | |
464 | ||
465 | return nc_path_tmp; | |
466 | } | |
467 | ||
468 | /** | |
469 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct | |
470 | * @nc_packet: the nc packet to send | |
471 | */ | |
472 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
473 | { | |
474 | batadv_send_skb_packet(nc_packet->skb, | |
475 | nc_packet->neigh_node->if_incoming, | |
476 | nc_packet->nc_path->next_hop); | |
477 | nc_packet->skb = NULL; | |
478 | batadv_nc_packet_free(nc_packet); | |
479 | } | |
480 | ||
612d2b4f MH |
481 | /** |
482 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. | |
483 | * @bat_priv: the bat priv with all the soft interface information | |
484 | * @nc_path: the nc path the packet belongs to | |
485 | * @nc_packet: the nc packet to be checked | |
486 | * | |
487 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
488 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
489 | * queue. Has to be called with the appropriate locks. | |
490 | * | |
491 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
492 | * yet and true otherwise. | |
493 | */ | |
494 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
495 | struct batadv_nc_path *nc_path, | |
496 | struct batadv_nc_packet *nc_packet) | |
497 | { | |
498 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
499 | bool res = false; | |
500 | ||
501 | /* Packets are added to tail, so the remaining packets did not time | |
502 | * out and we can stop processing the current queue | |
503 | */ | |
504 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
505 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
506 | goto out; | |
507 | ||
508 | /* purge nc packet */ | |
509 | list_del(&nc_packet->list); | |
510 | batadv_nc_packet_free(nc_packet); | |
511 | ||
512 | res = true; | |
513 | ||
514 | out: | |
515 | return res; | |
516 | } | |
517 | ||
95332477 MH |
518 | /** |
519 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. | |
520 | * @bat_priv: the bat priv with all the soft interface information | |
521 | * @nc_path: the nc path the packet belongs to | |
522 | * @nc_packet: the nc packet to be checked | |
523 | * | |
524 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
525 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
526 | * queue. Has to be called with the appropriate locks. | |
527 | * | |
528 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
529 | * yet and true otherwise. | |
530 | */ | |
531 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
532 | struct batadv_nc_path *nc_path, | |
533 | struct batadv_nc_packet *nc_packet) | |
534 | { | |
535 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
536 | ||
537 | /* Packets are added to tail, so the remaining packets did not time | |
538 | * out and we can stop processing the current queue | |
539 | */ | |
540 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
541 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
542 | return false; | |
543 | ||
544 | /* Send packet */ | |
545 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
546 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
547 | nc_packet->skb->len + ETH_HLEN); | |
548 | list_del(&nc_packet->list); | |
549 | batadv_nc_send_packet(nc_packet); | |
550 | ||
551 | return true; | |
552 | } | |
553 | ||
554 | /** | |
555 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out | |
556 | * nc packets | |
557 | * @bat_priv: the bat priv with all the soft interface information | |
558 | * @hash: to be processed hash table | |
559 | * @process_fn: Function called to process given nc packet. Should return true | |
560 | * to encourage this function to proceed with the next packet. | |
561 | * Otherwise the rest of the current queue is skipped. | |
562 | */ | |
563 | static void | |
564 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
565 | struct batadv_hashtable *hash, | |
566 | bool (*process_fn)(struct batadv_priv *, | |
567 | struct batadv_nc_path *, | |
568 | struct batadv_nc_packet *)) | |
569 | { | |
570 | struct hlist_head *head; | |
571 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
572 | struct batadv_nc_path *nc_path; | |
573 | bool ret; | |
574 | int i; | |
575 | ||
576 | if (!hash) | |
577 | return; | |
578 | ||
579 | /* Loop hash table bins */ | |
580 | for (i = 0; i < hash->size; i++) { | |
581 | head = &hash->table[i]; | |
582 | ||
583 | /* Loop coding paths */ | |
584 | rcu_read_lock(); | |
585 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
586 | /* Loop packets */ | |
587 | spin_lock_bh(&nc_path->packet_list_lock); | |
588 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
589 | &nc_path->packet_list, list) { | |
590 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
591 | if (!ret) | |
592 | break; | |
593 | } | |
594 | spin_unlock_bh(&nc_path->packet_list_lock); | |
595 | } | |
596 | rcu_read_unlock(); | |
597 | } | |
598 | } | |
599 | ||
d353d8d4 MH |
600 | /** |
601 | * batadv_nc_worker - periodic task for house keeping related to network coding | |
602 | * @work: kernel work struct | |
603 | */ | |
604 | static void batadv_nc_worker(struct work_struct *work) | |
605 | { | |
606 | struct delayed_work *delayed_work; | |
607 | struct batadv_priv_nc *priv_nc; | |
608 | struct batadv_priv *bat_priv; | |
95332477 | 609 | unsigned long timeout; |
d353d8d4 MH |
610 | |
611 | delayed_work = container_of(work, struct delayed_work, work); | |
612 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); | |
613 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
614 | ||
d56b1705 | 615 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
616 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
617 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
618 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
619 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
620 | |
621 | timeout = bat_priv->nc.max_fwd_delay; | |
622 | ||
623 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
624 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
625 | batadv_nc_fwd_flush); | |
626 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
627 | } | |
d56b1705 | 628 | |
612d2b4f MH |
629 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
630 | bat_priv->nc.max_buffer_time)) { | |
631 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
632 | batadv_nc_sniffed_purge); | |
633 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
634 | } | |
635 | ||
d353d8d4 MH |
636 | /* Schedule a new check */ |
637 | batadv_nc_start_timer(bat_priv); | |
638 | } | |
639 | ||
d56b1705 MH |
640 | /** |
641 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for | |
642 | * coding or not | |
643 | * @bat_priv: the bat priv with all the soft interface information | |
644 | * @orig_node: neighboring orig node which may be used as nc candidate | |
645 | * @ogm_packet: incoming ogm packet also used for the checks | |
646 | * | |
647 | * Returns true if: | |
648 | * 1) The OGM must have the most recent sequence number. | |
649 | * 2) The TTL must be decremented by one and only one. | |
650 | * 3) The OGM must be received from the first hop from orig_node. | |
651 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
652 | */ | |
653 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
654 | struct batadv_orig_node *orig_node, | |
655 | struct batadv_ogm_packet *ogm_packet) | |
656 | { | |
e6a0b495 | 657 | if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno)) |
d56b1705 MH |
658 | return false; |
659 | if (orig_node->last_ttl != ogm_packet->header.ttl + 1) | |
660 | return false; | |
661 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
662 | return false; | |
663 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
664 | return false; | |
665 | ||
666 | return true; | |
667 | } | |
668 | ||
669 | /** | |
670 | * batadv_nc_find_nc_node - search for an existing nc node and return it | |
671 | * @orig_node: orig node originating the ogm packet | |
672 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
673 | * (can be equal to orig_node) | |
674 | * @in_coding: traverse incoming or outgoing network coding list | |
675 | * | |
676 | * Returns the nc_node if found, NULL otherwise. | |
677 | */ | |
678 | static struct batadv_nc_node | |
679 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
680 | struct batadv_orig_node *orig_neigh_node, | |
681 | bool in_coding) | |
682 | { | |
683 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
684 | struct list_head *list; | |
685 | ||
686 | if (in_coding) | |
687 | list = &orig_neigh_node->in_coding_list; | |
688 | else | |
689 | list = &orig_neigh_node->out_coding_list; | |
690 | ||
691 | /* Traverse list of nc_nodes to orig_node */ | |
692 | rcu_read_lock(); | |
693 | list_for_each_entry_rcu(nc_node, list, list) { | |
694 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
695 | continue; | |
696 | ||
697 | if (!atomic_inc_not_zero(&nc_node->refcount)) | |
698 | continue; | |
699 | ||
700 | /* Found a match */ | |
701 | nc_node_out = nc_node; | |
702 | break; | |
703 | } | |
704 | rcu_read_unlock(); | |
705 | ||
706 | return nc_node_out; | |
707 | } | |
708 | ||
709 | /** | |
710 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was | |
711 | * not found | |
712 | * @bat_priv: the bat priv with all the soft interface information | |
713 | * @orig_node: orig node originating the ogm packet | |
714 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
715 | * (can be equal to orig_node) | |
716 | * @in_coding: traverse incoming or outgoing network coding list | |
717 | * | |
718 | * Returns the nc_node if found or created, NULL in case of an error. | |
719 | */ | |
720 | static struct batadv_nc_node | |
721 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
722 | struct batadv_orig_node *orig_node, | |
723 | struct batadv_orig_node *orig_neigh_node, | |
724 | bool in_coding) | |
725 | { | |
726 | struct batadv_nc_node *nc_node; | |
727 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
728 | struct list_head *list; | |
729 | ||
730 | /* Check if nc_node is already added */ | |
731 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
732 | ||
733 | /* Node found */ | |
734 | if (nc_node) | |
735 | return nc_node; | |
736 | ||
737 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
738 | if (!nc_node) | |
739 | return NULL; | |
740 | ||
741 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) | |
742 | goto free; | |
743 | ||
744 | /* Initialize nc_node */ | |
745 | INIT_LIST_HEAD(&nc_node->list); | |
746 | memcpy(nc_node->addr, orig_node->orig, ETH_ALEN); | |
747 | nc_node->orig_node = orig_neigh_node; | |
748 | atomic_set(&nc_node->refcount, 2); | |
749 | ||
750 | /* Select ingoing or outgoing coding node */ | |
751 | if (in_coding) { | |
752 | lock = &orig_neigh_node->in_coding_list_lock; | |
753 | list = &orig_neigh_node->in_coding_list; | |
754 | } else { | |
755 | lock = &orig_neigh_node->out_coding_list_lock; | |
756 | list = &orig_neigh_node->out_coding_list; | |
757 | } | |
758 | ||
759 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", | |
760 | nc_node->addr, nc_node->orig_node->orig); | |
761 | ||
762 | /* Add nc_node to orig_node */ | |
763 | spin_lock_bh(lock); | |
764 | list_add_tail_rcu(&nc_node->list, list); | |
765 | spin_unlock_bh(lock); | |
766 | ||
767 | return nc_node; | |
768 | ||
769 | free: | |
770 | kfree(nc_node); | |
771 | return NULL; | |
772 | } | |
773 | ||
774 | /** | |
775 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs | |
776 | * (best called on incoming OGMs) | |
777 | * @bat_priv: the bat priv with all the soft interface information | |
778 | * @orig_node: orig node originating the ogm packet | |
779 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
780 | * (can be equal to orig_node) | |
781 | * @ogm_packet: incoming ogm packet | |
782 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
783 | */ | |
784 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
785 | struct batadv_orig_node *orig_node, | |
786 | struct batadv_orig_node *orig_neigh_node, | |
787 | struct batadv_ogm_packet *ogm_packet, | |
788 | int is_single_hop_neigh) | |
789 | { | |
790 | struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL; | |
791 | ||
792 | /* Check if network coding is enabled */ | |
793 | if (!atomic_read(&bat_priv->network_coding)) | |
794 | goto out; | |
795 | ||
796 | /* accept ogms from 'good' neighbors and single hop neighbors */ | |
797 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
798 | !is_single_hop_neigh) | |
799 | goto out; | |
800 | ||
801 | /* Add orig_node as in_nc_node on hop */ | |
802 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
803 | orig_neigh_node, true); | |
804 | if (!in_nc_node) | |
805 | goto out; | |
806 | ||
807 | in_nc_node->last_seen = jiffies; | |
808 | ||
809 | /* Add hop as out_nc_node on orig_node */ | |
810 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
811 | orig_node, false); | |
812 | if (!out_nc_node) | |
813 | goto out; | |
814 | ||
815 | out_nc_node->last_seen = jiffies; | |
816 | ||
817 | out: | |
818 | if (in_nc_node) | |
819 | batadv_nc_node_free_ref(in_nc_node); | |
820 | if (out_nc_node) | |
821 | batadv_nc_node_free_ref(out_nc_node); | |
822 | } | |
823 | ||
95332477 MH |
824 | /** |
825 | * batadv_nc_get_path - get existing nc_path or allocate a new one | |
826 | * @bat_priv: the bat priv with all the soft interface information | |
827 | * @hash: hash table containing the nc path | |
828 | * @src: ethernet source address - first half of the nc path search key | |
829 | * @dst: ethernet destination address - second half of the nc path search key | |
830 | * | |
831 | * Returns pointer to nc_path if the path was found or created, returns NULL | |
832 | * on error. | |
833 | */ | |
834 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
835 | struct batadv_hashtable *hash, | |
836 | uint8_t *src, | |
837 | uint8_t *dst) | |
838 | { | |
839 | int hash_added; | |
840 | struct batadv_nc_path *nc_path, nc_path_key; | |
841 | ||
842 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
843 | ||
844 | /* Search for existing nc_path */ | |
845 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
846 | ||
847 | if (nc_path) { | |
848 | /* Set timestamp to delay removal of nc_path */ | |
849 | nc_path->last_valid = jiffies; | |
850 | return nc_path; | |
851 | } | |
852 | ||
853 | /* No existing nc_path was found; create a new */ | |
854 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
855 | ||
856 | if (!nc_path) | |
857 | return NULL; | |
858 | ||
859 | /* Initialize nc_path */ | |
860 | INIT_LIST_HEAD(&nc_path->packet_list); | |
861 | spin_lock_init(&nc_path->packet_list_lock); | |
862 | atomic_set(&nc_path->refcount, 2); | |
863 | nc_path->last_valid = jiffies; | |
864 | memcpy(nc_path->next_hop, dst, ETH_ALEN); | |
865 | memcpy(nc_path->prev_hop, src, ETH_ALEN); | |
866 | ||
867 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
868 | nc_path->prev_hop, | |
869 | nc_path->next_hop); | |
870 | ||
871 | /* Add nc_path to hash table */ | |
872 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, | |
873 | batadv_nc_hash_choose, &nc_path_key, | |
874 | &nc_path->hash_entry); | |
875 | ||
876 | if (hash_added < 0) { | |
877 | kfree(nc_path); | |
878 | return NULL; | |
879 | } | |
880 | ||
881 | return nc_path; | |
882 | } | |
883 | ||
3c12de9a MH |
884 | /** |
885 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair | |
886 | * selection of a receiver with slightly lower TQ than the other | |
887 | * @tq: to be weighted tq value | |
888 | */ | |
889 | static uint8_t batadv_nc_random_weight_tq(uint8_t tq) | |
890 | { | |
891 | uint8_t rand_val, rand_tq; | |
892 | ||
893 | get_random_bytes(&rand_val, sizeof(rand_val)); | |
894 | ||
895 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ | |
896 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); | |
897 | ||
898 | /* normalize the randomized packet loss */ | |
899 | rand_tq /= BATADV_TQ_MAX_VALUE; | |
900 | ||
901 | /* convert to (randomized) estimated tq again */ | |
902 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
903 | } | |
904 | ||
905 | /** | |
906 | * batadv_nc_memxor - XOR destination with source | |
907 | * @dst: byte array to XOR into | |
908 | * @src: byte array to XOR from | |
909 | * @len: length of destination array | |
910 | */ | |
911 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
912 | { | |
913 | unsigned int i; | |
914 | ||
915 | for (i = 0; i < len; ++i) | |
916 | dst[i] ^= src[i]; | |
917 | } | |
918 | ||
919 | /** | |
920 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet | |
921 | * into a coded_packet and send it | |
922 | * @bat_priv: the bat priv with all the soft interface information | |
923 | * @skb: data skb to forward | |
924 | * @ethhdr: pointer to the ethernet header inside the skb | |
925 | * @nc_packet: structure containing the packet to the skb can be coded with | |
926 | * @neigh_node: next hop to forward packet to | |
927 | * | |
928 | * Returns true if both packets are consumed, false otherwise. | |
929 | */ | |
930 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
931 | struct sk_buff *skb, | |
932 | struct ethhdr *ethhdr, | |
933 | struct batadv_nc_packet *nc_packet, | |
934 | struct batadv_neigh_node *neigh_node) | |
935 | { | |
936 | uint8_t tq_weighted_neigh, tq_weighted_coding; | |
937 | struct sk_buff *skb_dest, *skb_src; | |
938 | struct batadv_unicast_packet *packet1; | |
939 | struct batadv_unicast_packet *packet2; | |
940 | struct batadv_coded_packet *coded_packet; | |
941 | struct batadv_neigh_node *neigh_tmp, *router_neigh; | |
942 | struct batadv_neigh_node *router_coding = NULL; | |
943 | uint8_t *first_source, *first_dest, *second_source, *second_dest; | |
944 | __be32 packet_id1, packet_id2; | |
945 | size_t count; | |
946 | bool res = false; | |
947 | int coding_len; | |
948 | int unicast_size = sizeof(*packet1); | |
949 | int coded_size = sizeof(*coded_packet); | |
950 | int header_add = coded_size - unicast_size; | |
951 | ||
952 | router_neigh = batadv_orig_node_get_router(neigh_node->orig_node); | |
953 | if (!router_neigh) | |
954 | goto out; | |
955 | ||
956 | neigh_tmp = nc_packet->neigh_node; | |
957 | router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node); | |
958 | if (!router_coding) | |
959 | goto out; | |
960 | ||
961 | tq_weighted_neigh = batadv_nc_random_weight_tq(router_neigh->tq_avg); | |
962 | tq_weighted_coding = batadv_nc_random_weight_tq(router_coding->tq_avg); | |
963 | ||
964 | /* Select one destination for the MAC-header dst-field based on | |
965 | * weighted TQ-values. | |
966 | */ | |
967 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
968 | /* Destination from nc_packet is selected for MAC-header */ | |
969 | first_dest = nc_packet->nc_path->next_hop; | |
970 | first_source = nc_packet->nc_path->prev_hop; | |
971 | second_dest = neigh_node->addr; | |
972 | second_source = ethhdr->h_source; | |
973 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
974 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
975 | packet_id1 = nc_packet->packet_id; | |
976 | packet_id2 = batadv_skb_crc32(skb, | |
977 | skb->data + sizeof(*packet2)); | |
978 | } else { | |
979 | /* Destination for skb is selected for MAC-header */ | |
980 | first_dest = neigh_node->addr; | |
981 | first_source = ethhdr->h_source; | |
982 | second_dest = nc_packet->nc_path->next_hop; | |
983 | second_source = nc_packet->nc_path->prev_hop; | |
984 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
985 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
986 | packet_id1 = batadv_skb_crc32(skb, | |
987 | skb->data + sizeof(*packet1)); | |
988 | packet_id2 = nc_packet->packet_id; | |
989 | } | |
990 | ||
991 | /* Instead of zero padding the smallest data buffer, we | |
992 | * code into the largest. | |
993 | */ | |
994 | if (skb->len <= nc_packet->skb->len) { | |
995 | skb_dest = nc_packet->skb; | |
996 | skb_src = skb; | |
997 | } else { | |
998 | skb_dest = skb; | |
999 | skb_src = nc_packet->skb; | |
1000 | } | |
1001 | ||
1002 | /* coding_len is used when decoding the packet shorter packet */ | |
1003 | coding_len = skb_src->len - unicast_size; | |
1004 | ||
1005 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1006 | goto out; | |
1007 | ||
1008 | skb_push(skb_dest, header_add); | |
1009 | ||
1010 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1011 | skb_reset_mac_header(skb_dest); | |
1012 | ||
1013 | coded_packet->header.packet_type = BATADV_CODED; | |
1014 | coded_packet->header.version = BATADV_COMPAT_VERSION; | |
1015 | coded_packet->header.ttl = packet1->header.ttl; | |
1016 | ||
1017 | /* Info about first unicast packet */ | |
1018 | memcpy(coded_packet->first_source, first_source, ETH_ALEN); | |
1019 | memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN); | |
1020 | coded_packet->first_crc = packet_id1; | |
1021 | coded_packet->first_ttvn = packet1->ttvn; | |
1022 | ||
1023 | /* Info about second unicast packet */ | |
1024 | memcpy(coded_packet->second_dest, second_dest, ETH_ALEN); | |
1025 | memcpy(coded_packet->second_source, second_source, ETH_ALEN); | |
1026 | memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN); | |
1027 | coded_packet->second_crc = packet_id2; | |
1028 | coded_packet->second_ttl = packet2->header.ttl; | |
1029 | coded_packet->second_ttvn = packet2->ttvn; | |
1030 | coded_packet->coded_len = htons(coding_len); | |
1031 | ||
1032 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1033 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1034 | skb_src->data + unicast_size, coding_len); | |
1035 | ||
1036 | /* Update counters accordingly */ | |
1037 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1038 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1039 | /* Both packets are recoded */ | |
1040 | count = skb_src->len + ETH_HLEN; | |
1041 | count += skb_dest->len + ETH_HLEN; | |
1042 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1043 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1044 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1045 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1046 | /* Both packets are newly coded */ | |
1047 | count = skb_src->len + ETH_HLEN; | |
1048 | count += skb_dest->len + ETH_HLEN; | |
1049 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1050 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1051 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1052 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1053 | /* skb_src recoded and skb_dest is newly coded */ | |
1054 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1055 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1056 | skb_src->len + ETH_HLEN); | |
1057 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1058 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1059 | skb_dest->len + ETH_HLEN); | |
1060 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1061 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1062 | /* skb_src is newly coded and skb_dest is recoded */ | |
1063 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1064 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1065 | skb_src->len + ETH_HLEN); | |
1066 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1067 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1068 | skb_dest->len + ETH_HLEN); | |
1069 | } | |
1070 | ||
1071 | /* skb_src is now coded into skb_dest, so free it */ | |
1072 | kfree_skb(skb_src); | |
1073 | ||
1074 | /* avoid duplicate free of skb from nc_packet */ | |
1075 | nc_packet->skb = NULL; | |
1076 | batadv_nc_packet_free(nc_packet); | |
1077 | ||
1078 | /* Send the coded packet and return true */ | |
1079 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); | |
1080 | res = true; | |
1081 | out: | |
1082 | if (router_neigh) | |
1083 | batadv_neigh_node_free_ref(router_neigh); | |
1084 | if (router_coding) | |
1085 | batadv_neigh_node_free_ref(router_coding); | |
1086 | return res; | |
1087 | } | |
1088 | ||
1089 | /** | |
1090 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. | |
1091 | * @skb: data skb to forward | |
1092 | * @dst: destination mac address of the other skb to code with | |
1093 | * @src: source mac address of skb | |
1094 | * | |
1095 | * Whenever we network code a packet we have to check whether we received it in | |
1096 | * a network coded form. If so, we may not be able to use it for coding because | |
1097 | * some neighbors may also have received (overheard) the packet in the network | |
1098 | * coded form without being able to decode it. It is hard to know which of the | |
1099 | * neighboring nodes was able to decode the packet, therefore we can only | |
1100 | * re-code the packet if the source of the previous encoded packet is involved. | |
1101 | * Since the source encoded the packet we can be certain it has all necessary | |
1102 | * decode information. | |
1103 | * | |
1104 | * Returns true if coding of a decoded packet is allowed. | |
1105 | */ | |
1106 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, | |
1107 | uint8_t *dst, uint8_t *src) | |
1108 | { | |
1109 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1110 | return false; | |
1111 | else | |
1112 | return true; | |
1113 | } | |
1114 | ||
1115 | /** | |
1116 | * batadv_nc_path_search - Find the coding path matching in_nc_node and | |
1117 | * out_nc_node to retrieve a buffered packet that can be used for coding. | |
1118 | * @bat_priv: the bat priv with all the soft interface information | |
1119 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1120 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1121 | * @skb: data skb to forward | |
1122 | * @eth_dst: next hop mac address of skb | |
1123 | * | |
1124 | * Returns true if coding of a decoded skb is allowed. | |
1125 | */ | |
1126 | static struct batadv_nc_packet * | |
1127 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1128 | struct batadv_nc_node *in_nc_node, | |
1129 | struct batadv_nc_node *out_nc_node, | |
1130 | struct sk_buff *skb, | |
1131 | uint8_t *eth_dst) | |
1132 | { | |
1133 | struct batadv_nc_path *nc_path, nc_path_key; | |
1134 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1135 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1136 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1137 | int idx; | |
1138 | ||
1139 | if (!hash) | |
1140 | return NULL; | |
1141 | ||
1142 | /* Create almost path key */ | |
1143 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1144 | out_nc_node->addr); | |
1145 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1146 | ||
1147 | /* Check for coding opportunities in this nc_path */ | |
1148 | rcu_read_lock(); | |
1149 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1150 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1151 | continue; | |
1152 | ||
1153 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1154 | continue; | |
1155 | ||
1156 | spin_lock_bh(&nc_path->packet_list_lock); | |
1157 | if (list_empty(&nc_path->packet_list)) { | |
1158 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1159 | continue; | |
1160 | } | |
1161 | ||
1162 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1163 | &nc_path->packet_list, list) { | |
1164 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1165 | eth_dst, | |
1166 | in_nc_node->addr)) | |
1167 | continue; | |
1168 | ||
1169 | /* Coding opportunity is found! */ | |
1170 | list_del(&nc_packet->list); | |
1171 | nc_packet_out = nc_packet; | |
1172 | break; | |
1173 | } | |
1174 | ||
1175 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1176 | break; | |
1177 | } | |
1178 | rcu_read_unlock(); | |
1179 | ||
1180 | return nc_packet_out; | |
1181 | } | |
1182 | ||
1183 | /** | |
1184 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the | |
1185 | * skb's sender (may be equal to the originator). | |
1186 | * @bat_priv: the bat priv with all the soft interface information | |
1187 | * @skb: data skb to forward | |
1188 | * @eth_dst: next hop mac address of skb | |
1189 | * @eth_src: source mac address of skb | |
1190 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1191 | * | |
1192 | * Returns an nc packet if a suitable coding packet was found, NULL otherwise. | |
1193 | */ | |
1194 | static struct batadv_nc_packet * | |
1195 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1196 | struct sk_buff *skb, | |
1197 | uint8_t *eth_dst, | |
1198 | uint8_t *eth_src, | |
1199 | struct batadv_nc_node *in_nc_node) | |
1200 | { | |
1201 | struct batadv_orig_node *orig_node; | |
1202 | struct batadv_nc_node *out_nc_node; | |
1203 | struct batadv_nc_packet *nc_packet = NULL; | |
1204 | ||
1205 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1206 | if (!orig_node) | |
1207 | return NULL; | |
1208 | ||
1209 | rcu_read_lock(); | |
1210 | list_for_each_entry_rcu(out_nc_node, | |
1211 | &orig_node->out_coding_list, list) { | |
1212 | /* Check if the skb is decoded and if recoding is possible */ | |
1213 | if (!batadv_nc_skb_coding_possible(skb, | |
1214 | out_nc_node->addr, eth_src)) | |
1215 | continue; | |
1216 | ||
1217 | /* Search for an opportunity in this nc_path */ | |
1218 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1219 | out_nc_node, skb, eth_dst); | |
1220 | if (nc_packet) | |
1221 | break; | |
1222 | } | |
1223 | rcu_read_unlock(); | |
1224 | ||
1225 | batadv_orig_node_free_ref(orig_node); | |
1226 | return nc_packet; | |
1227 | } | |
1228 | ||
612d2b4f MH |
1229 | /** |
1230 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the | |
1231 | * unicast skb before it is stored for use in later decoding | |
1232 | * @bat_priv: the bat priv with all the soft interface information | |
1233 | * @skb: data skb to store | |
1234 | * @eth_dst_new: new destination mac address of skb | |
1235 | */ | |
1236 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1237 | struct sk_buff *skb, | |
1238 | uint8_t *eth_dst_new) | |
1239 | { | |
1240 | struct ethhdr *ethhdr; | |
1241 | ||
1242 | /* Copy skb header to change the mac header */ | |
1243 | skb = pskb_copy(skb, GFP_ATOMIC); | |
1244 | if (!skb) | |
1245 | return; | |
1246 | ||
1247 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1248 | ethhdr = eth_hdr(skb); |
612d2b4f MH |
1249 | memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN); |
1250 | memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN); | |
1251 | ||
1252 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1253 | skb_push(skb, ETH_HLEN); | |
1254 | ||
1255 | /* Add the packet to the decoding packet pool */ | |
1256 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1257 | ||
1258 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1259 | * our ref | |
1260 | */ | |
1261 | kfree_skb(skb); | |
1262 | } | |
1263 | ||
3c12de9a MH |
1264 | /** |
1265 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. | |
1266 | * @skb: data skb to forward | |
1267 | * @neigh_node: next hop to forward packet to | |
1268 | * @ethhdr: pointer to the ethernet header inside the skb | |
1269 | * | |
1270 | * Loops through list of neighboring nodes the next hop has a good connection to | |
1271 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our | |
1272 | * next hop that potentially sent a packet which our next hop also received | |
1273 | * (overheard) and has stored for later decoding. | |
1274 | * | |
1275 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1276 | */ | |
1277 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1278 | struct batadv_neigh_node *neigh_node, | |
1279 | struct ethhdr *ethhdr) | |
1280 | { | |
1281 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1282 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1283 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1284 | struct batadv_nc_node *nc_node; | |
1285 | struct batadv_nc_packet *nc_packet = NULL; | |
1286 | ||
1287 | rcu_read_lock(); | |
1288 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1289 | /* Search for coding opportunity with this in_nc_node */ | |
1290 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1291 | neigh_node->addr, | |
1292 | ethhdr->h_source, nc_node); | |
1293 | ||
1294 | /* Opportunity was found, so stop searching */ | |
1295 | if (nc_packet) | |
1296 | break; | |
1297 | } | |
1298 | rcu_read_unlock(); | |
1299 | ||
1300 | if (!nc_packet) | |
1301 | return false; | |
1302 | ||
612d2b4f MH |
1303 | /* Save packets for later decoding */ |
1304 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1305 | neigh_node->addr); | |
1306 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1307 | nc_packet->neigh_node->addr); | |
1308 | ||
3c12de9a MH |
1309 | /* Code and send packets */ |
1310 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1311 | neigh_node)) | |
1312 | return true; | |
1313 | ||
1314 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1315 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1316 | * by the calling function. | |
1317 | */ | |
1318 | batadv_nc_send_packet(nc_packet); | |
1319 | return false; | |
1320 | } | |
1321 | ||
95332477 MH |
1322 | /** |
1323 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding | |
1324 | * @skb: skb to add to path | |
1325 | * @nc_path: path to add skb to | |
1326 | * @neigh_node: next hop to forward packet to | |
1327 | * @packet_id: checksum to identify packet | |
1328 | * | |
1329 | * Returns true if the packet was buffered or false in case of an error. | |
1330 | */ | |
1331 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1332 | struct batadv_nc_path *nc_path, | |
1333 | struct batadv_neigh_node *neigh_node, | |
1334 | __be32 packet_id) | |
1335 | { | |
1336 | struct batadv_nc_packet *nc_packet; | |
1337 | ||
1338 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1339 | if (!nc_packet) | |
1340 | return false; | |
1341 | ||
1342 | /* Initialize nc_packet */ | |
1343 | nc_packet->timestamp = jiffies; | |
1344 | nc_packet->packet_id = packet_id; | |
1345 | nc_packet->skb = skb; | |
1346 | nc_packet->neigh_node = neigh_node; | |
1347 | nc_packet->nc_path = nc_path; | |
1348 | ||
1349 | /* Add coding packet to list */ | |
1350 | spin_lock_bh(&nc_path->packet_list_lock); | |
1351 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1352 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1353 | ||
1354 | return true; | |
1355 | } | |
1356 | ||
1357 | /** | |
1358 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet | |
1359 | * buffer | |
1360 | * @skb: data skb to forward | |
1361 | * @neigh_node: next hop to forward packet to | |
1362 | * @ethhdr: pointer to the ethernet header inside the skb | |
1363 | * | |
1364 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1365 | */ | |
1366 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
1367 | struct batadv_neigh_node *neigh_node, | |
1368 | struct ethhdr *ethhdr) | |
1369 | { | |
1370 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1371 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1372 | struct batadv_unicast_packet *packet; | |
1373 | struct batadv_nc_path *nc_path; | |
1374 | __be32 packet_id; | |
1375 | u8 *payload; | |
1376 | ||
1377 | /* Check if network coding is enabled */ | |
1378 | if (!atomic_read(&bat_priv->network_coding)) | |
1379 | goto out; | |
1380 | ||
1381 | /* We only handle unicast packets */ | |
1382 | payload = skb_network_header(skb); | |
1383 | packet = (struct batadv_unicast_packet *)payload; | |
1384 | if (packet->header.packet_type != BATADV_UNICAST) | |
1385 | goto out; | |
1386 | ||
3c12de9a MH |
1387 | /* Try to find a coding opportunity and send the skb if one is found */ |
1388 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1389 | return true; | |
1390 | ||
95332477 MH |
1391 | /* Find or create a nc_path for this src-dst pair */ |
1392 | nc_path = batadv_nc_get_path(bat_priv, | |
1393 | bat_priv->nc.coding_hash, | |
1394 | ethhdr->h_source, | |
1395 | neigh_node->addr); | |
1396 | ||
1397 | if (!nc_path) | |
1398 | goto out; | |
1399 | ||
1400 | /* Add skb to nc_path */ | |
1401 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1402 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1403 | goto free_nc_path; | |
1404 | ||
1405 | /* Packet is consumed */ | |
1406 | return true; | |
1407 | ||
1408 | free_nc_path: | |
1409 | batadv_nc_path_free_ref(nc_path); | |
1410 | out: | |
1411 | /* Packet is not consumed */ | |
1412 | return false; | |
1413 | } | |
1414 | ||
612d2b4f MH |
1415 | /** |
1416 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used | |
1417 | * when decoding coded packets | |
1418 | * @bat_priv: the bat priv with all the soft interface information | |
1419 | * @skb: data skb to store | |
1420 | */ | |
1421 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1422 | struct sk_buff *skb) | |
1423 | { | |
1424 | struct batadv_unicast_packet *packet; | |
1425 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1426 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1427 | __be32 packet_id; |
1428 | u8 *payload; | |
1429 | ||
1430 | /* Check if network coding is enabled */ | |
1431 | if (!atomic_read(&bat_priv->network_coding)) | |
1432 | goto out; | |
1433 | ||
1434 | /* Check for supported packet type */ | |
1435 | payload = skb_network_header(skb); | |
1436 | packet = (struct batadv_unicast_packet *)payload; | |
1437 | if (packet->header.packet_type != BATADV_UNICAST) | |
1438 | goto out; | |
1439 | ||
1440 | /* Find existing nc_path or create a new */ | |
1441 | nc_path = batadv_nc_get_path(bat_priv, | |
1442 | bat_priv->nc.decoding_hash, | |
1443 | ethhdr->h_source, | |
1444 | ethhdr->h_dest); | |
1445 | ||
1446 | if (!nc_path) | |
1447 | goto out; | |
1448 | ||
1449 | /* Clone skb and adjust skb->data to point at batman header */ | |
1450 | skb = skb_clone(skb, GFP_ATOMIC); | |
1451 | if (unlikely(!skb)) | |
1452 | goto free_nc_path; | |
1453 | ||
1454 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1455 | goto free_skb; | |
1456 | ||
1457 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1458 | goto free_skb; | |
1459 | ||
1460 | /* Add skb to nc_path */ | |
1461 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1462 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1463 | goto free_skb; | |
1464 | ||
1465 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1466 | return; | |
1467 | ||
1468 | free_skb: | |
1469 | kfree_skb(skb); | |
1470 | free_nc_path: | |
1471 | batadv_nc_path_free_ref(nc_path); | |
1472 | out: | |
1473 | return; | |
1474 | } | |
1475 | ||
1476 | /** | |
1477 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet | |
1478 | * should be saved in the decoding buffer and, if so, store it there | |
1479 | * @bat_priv: the bat priv with all the soft interface information | |
1480 | * @skb: unicast skb to store | |
1481 | */ | |
1482 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1483 | struct sk_buff *skb) | |
1484 | { | |
7ed4be95 | 1485 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1486 | |
6e0895c2 | 1487 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1488 | return; |
1489 | ||
1490 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1491 | skb_push(skb, ETH_HLEN); | |
1492 | ||
1493 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1494 | } | |
1495 | ||
2df5278b MH |
1496 | /** |
1497 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored | |
1498 | * in nc_packet | |
6e0895c2 | 1499 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1500 | * @skb: unicast skb to decode |
1501 | * @nc_packet: decode data needed to decode the skb | |
1502 | * | |
1503 | * Returns pointer to decoded unicast packet if the packet was decoded or NULL | |
1504 | * in case of an error. | |
1505 | */ | |
1506 | static struct batadv_unicast_packet * | |
6e0895c2 | 1507 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1508 | struct batadv_nc_packet *nc_packet) |
1509 | { | |
1510 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1511 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1512 | struct batadv_unicast_packet *unicast_packet; | |
1513 | struct batadv_coded_packet coded_packet_tmp; | |
1514 | struct ethhdr *ethhdr, ethhdr_tmp; | |
1515 | uint8_t *orig_dest, ttl, ttvn; | |
1516 | unsigned int coding_len; | |
7da19971 | 1517 | int err; |
2df5278b MH |
1518 | |
1519 | /* Save headers temporarily */ | |
1520 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1521 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1522 | ||
1523 | if (skb_cow(skb, 0) < 0) | |
1524 | return NULL; | |
1525 | ||
1526 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1527 | return NULL; | |
1528 | ||
1529 | /* Data points to batman header, so set mac header 14 bytes before | |
1530 | * and network to data | |
1531 | */ | |
1532 | skb_set_mac_header(skb, -ETH_HLEN); | |
1533 | skb_reset_network_header(skb); | |
1534 | ||
1535 | /* Reconstruct original mac header */ | |
7ed4be95 | 1536 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1537 | memcpy(ethhdr, ðhdr_tmp, sizeof(*ethhdr)); |
1538 | ||
1539 | /* Select the correct unicast header information based on the location | |
1540 | * of our mac address in the coded_packet header | |
1541 | */ | |
6e0895c2 | 1542 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1543 | /* If we are the second destination the packet was overheard, |
1544 | * so the Ethernet address must be copied to h_dest and | |
1545 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1546 | */ | |
1547 | memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN); | |
1548 | skb->pkt_type = PACKET_HOST; | |
1549 | ||
1550 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1551 | ttl = coded_packet_tmp.second_ttl; | |
1552 | ttvn = coded_packet_tmp.second_ttvn; | |
1553 | } else { | |
1554 | orig_dest = coded_packet_tmp.first_orig_dest; | |
1555 | ttl = coded_packet_tmp.header.ttl; | |
1556 | ttvn = coded_packet_tmp.first_ttvn; | |
1557 | } | |
1558 | ||
1559 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1560 | ||
1561 | if (coding_len > skb->len) | |
1562 | return NULL; | |
1563 | ||
1564 | /* Here the magic is reversed: | |
1565 | * extract the missing packet from the received coded packet | |
1566 | */ | |
1567 | batadv_nc_memxor(skb->data + h_size, | |
1568 | nc_packet->skb->data + h_size, | |
1569 | coding_len); | |
1570 | ||
1571 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1572 | if (nc_packet->skb->len > coding_len + h_size) { |
1573 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1574 | if (err) | |
1575 | return NULL; | |
1576 | } | |
2df5278b MH |
1577 | |
1578 | /* Create decoded unicast packet */ | |
1579 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
1580 | unicast_packet->header.packet_type = BATADV_UNICAST; | |
1581 | unicast_packet->header.version = BATADV_COMPAT_VERSION; | |
1582 | unicast_packet->header.ttl = ttl; | |
1583 | memcpy(unicast_packet->dest, orig_dest, ETH_ALEN); | |
1584 | unicast_packet->ttvn = ttvn; | |
1585 | ||
1586 | batadv_nc_packet_free(nc_packet); | |
1587 | return unicast_packet; | |
1588 | } | |
1589 | ||
1590 | /** | |
1591 | * batadv_nc_find_decoding_packet - search through buffered decoding data to | |
1592 | * find the data needed to decode the coded packet | |
1593 | * @bat_priv: the bat priv with all the soft interface information | |
1594 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1595 | * @coded: coded packet we try to find decode data for | |
1596 | * | |
1597 | * Returns pointer to nc packet if the needed data was found or NULL otherwise. | |
1598 | */ | |
1599 | static struct batadv_nc_packet * | |
1600 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1601 | struct ethhdr *ethhdr, | |
1602 | struct batadv_coded_packet *coded) | |
1603 | { | |
1604 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1605 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1606 | struct batadv_nc_path *nc_path, nc_path_key; | |
1607 | uint8_t *dest, *source; | |
1608 | __be32 packet_id; | |
1609 | int index; | |
1610 | ||
1611 | if (!hash) | |
1612 | return NULL; | |
1613 | ||
1614 | /* Select the correct packet id based on the location of our mac-addr */ | |
1615 | dest = ethhdr->h_source; | |
6e0895c2 | 1616 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1617 | source = coded->second_source; |
1618 | packet_id = coded->second_crc; | |
1619 | } else { | |
1620 | source = coded->first_source; | |
1621 | packet_id = coded->first_crc; | |
1622 | } | |
1623 | ||
1624 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1625 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1626 | ||
1627 | /* Search for matching coding path */ | |
1628 | rcu_read_lock(); | |
1629 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1630 | /* Find matching nc_packet */ | |
1631 | spin_lock_bh(&nc_path->packet_list_lock); | |
1632 | list_for_each_entry(tmp_nc_packet, | |
1633 | &nc_path->packet_list, list) { | |
1634 | if (packet_id == tmp_nc_packet->packet_id) { | |
1635 | list_del(&tmp_nc_packet->list); | |
1636 | ||
1637 | nc_packet = tmp_nc_packet; | |
1638 | break; | |
1639 | } | |
1640 | } | |
1641 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1642 | ||
1643 | if (nc_packet) | |
1644 | break; | |
1645 | } | |
1646 | rcu_read_unlock(); | |
1647 | ||
1648 | if (!nc_packet) | |
1649 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1650 | "No decoding packet found for %u\n", packet_id); | |
1651 | ||
1652 | return nc_packet; | |
1653 | } | |
1654 | ||
1655 | /** | |
1656 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the | |
1657 | * resulting unicast packet | |
1658 | * @skb: incoming coded packet | |
1659 | * @recv_if: pointer to interface this packet was received on | |
1660 | */ | |
1661 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1662 | struct batadv_hard_iface *recv_if) | |
1663 | { | |
1664 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1665 | struct batadv_unicast_packet *unicast_packet; | |
1666 | struct batadv_coded_packet *coded_packet; | |
1667 | struct batadv_nc_packet *nc_packet; | |
1668 | struct ethhdr *ethhdr; | |
1669 | int hdr_size = sizeof(*coded_packet); | |
1670 | ||
1671 | /* Check if network coding is enabled */ | |
1672 | if (!atomic_read(&bat_priv->network_coding)) | |
1673 | return NET_RX_DROP; | |
1674 | ||
1675 | /* Make sure we can access (and remove) header */ | |
1676 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
1677 | return NET_RX_DROP; | |
1678 | ||
1679 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1680 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1681 | |
1682 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1683 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1684 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
2df5278b MH |
1685 | return NET_RX_DROP; |
1686 | ||
1687 | /* Update stat counter */ | |
6e0895c2 | 1688 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1689 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1690 | ||
1691 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1692 | coded_packet); | |
1693 | if (!nc_packet) { | |
1694 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1695 | return NET_RX_DROP; | |
1696 | } | |
1697 | ||
1698 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1699 | if (skb_linearize(skb) < 0) | |
1700 | goto free_nc_packet; | |
1701 | ||
1702 | if (skb_linearize(nc_packet->skb) < 0) | |
1703 | goto free_nc_packet; | |
1704 | ||
1705 | /* Decode the packet */ | |
6e0895c2 | 1706 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1707 | if (!unicast_packet) { |
1708 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1709 | goto free_nc_packet; | |
1710 | } | |
1711 | ||
1712 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1713 | BATADV_SKB_CB(skb)->decoded = true; | |
1714 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1715 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1716 | skb->len + ETH_HLEN); | |
1717 | return batadv_recv_unicast_packet(skb, recv_if); | |
1718 | ||
1719 | free_nc_packet: | |
1720 | batadv_nc_packet_free(nc_packet); | |
1721 | return NET_RX_DROP; | |
1722 | } | |
1723 | ||
d353d8d4 MH |
1724 | /** |
1725 | * batadv_nc_free - clean up network coding memory | |
1726 | * @bat_priv: the bat priv with all the soft interface information | |
1727 | */ | |
1728 | void batadv_nc_free(struct batadv_priv *bat_priv) | |
1729 | { | |
2df5278b | 1730 | batadv_recv_handler_unregister(BATADV_CODED); |
d353d8d4 | 1731 | cancel_delayed_work_sync(&bat_priv->nc.work); |
612d2b4f | 1732 | |
95332477 MH |
1733 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1734 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1735 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1736 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1737 | } |
d56b1705 MH |
1738 | |
1739 | /** | |
1740 | * batadv_nc_nodes_seq_print_text - print the nc node information | |
1741 | * @seq: seq file to print on | |
1742 | * @offset: not used | |
1743 | */ | |
1744 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) | |
1745 | { | |
1746 | struct net_device *net_dev = (struct net_device *)seq->private; | |
1747 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
1748 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
1749 | struct batadv_hard_iface *primary_if; | |
1750 | struct hlist_head *head; | |
1751 | struct batadv_orig_node *orig_node; | |
1752 | struct batadv_nc_node *nc_node; | |
1753 | int i; | |
1754 | ||
1755 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
1756 | if (!primary_if) | |
1757 | goto out; | |
1758 | ||
1759 | /* Traverse list of originators */ | |
1760 | for (i = 0; i < hash->size; i++) { | |
1761 | head = &hash->table[i]; | |
1762 | ||
1763 | /* For each orig_node in this bin */ | |
1764 | rcu_read_lock(); | |
1765 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { | |
1766 | seq_printf(seq, "Node: %pM\n", orig_node->orig); | |
1767 | ||
0c814653 | 1768 | seq_puts(seq, " Ingoing: "); |
d56b1705 MH |
1769 | /* For each in_nc_node to this orig_node */ |
1770 | list_for_each_entry_rcu(nc_node, | |
1771 | &orig_node->in_coding_list, | |
1772 | list) | |
1773 | seq_printf(seq, "%pM ", | |
1774 | nc_node->addr); | |
0c814653 | 1775 | seq_puts(seq, "\n"); |
d56b1705 | 1776 | |
0c814653 | 1777 | seq_puts(seq, " Outgoing: "); |
d56b1705 MH |
1778 | /* For out_nc_node to this orig_node */ |
1779 | list_for_each_entry_rcu(nc_node, | |
1780 | &orig_node->out_coding_list, | |
1781 | list) | |
1782 | seq_printf(seq, "%pM ", | |
1783 | nc_node->addr); | |
0c814653 | 1784 | seq_puts(seq, "\n\n"); |
d56b1705 MH |
1785 | } |
1786 | rcu_read_unlock(); | |
1787 | } | |
1788 | ||
1789 | out: | |
1790 | if (primary_if) | |
1791 | batadv_hardif_free_ref(primary_if); | |
1792 | return 0; | |
1793 | } | |
1794 | ||
1795 | /** | |
1796 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs | |
1797 | * @bat_priv: the bat priv with all the soft interface information | |
1798 | */ | |
1799 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) | |
1800 | { | |
1801 | struct dentry *nc_dir, *file; | |
1802 | ||
1803 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); | |
1804 | if (!nc_dir) | |
1805 | goto out; | |
1806 | ||
1807 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, | |
1808 | &bat_priv->nc.min_tq); | |
1809 | if (!file) | |
1810 | goto out; | |
1811 | ||
95332477 MH |
1812 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1813 | &bat_priv->nc.max_fwd_delay); | |
1814 | if (!file) | |
1815 | goto out; | |
1816 | ||
612d2b4f MH |
1817 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1818 | &bat_priv->nc.max_buffer_time); | |
1819 | if (!file) | |
1820 | goto out; | |
1821 | ||
d56b1705 MH |
1822 | return 0; |
1823 | ||
1824 | out: | |
1825 | return -ENOMEM; | |
1826 | } |