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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 | 36 | |
6c519bad MS |
37 | /** |
38 | * batadv_nc_init - one-time initialization for network coding | |
39 | */ | |
40 | int __init batadv_nc_init(void) | |
41 | { | |
42 | int ret; | |
43 | ||
44 | /* Register our packet type */ | |
45 | ret = batadv_recv_handler_register(BATADV_CODED, | |
46 | batadv_nc_recv_coded_packet); | |
47 | ||
48 | return ret; | |
49 | } | |
50 | ||
d353d8d4 MH |
51 | /** |
52 | * batadv_nc_start_timer - initialise the nc periodic worker | |
53 | * @bat_priv: the bat priv with all the soft interface information | |
54 | */ | |
55 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
56 | { | |
57 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
58 | msecs_to_jiffies(10)); | |
59 | } | |
60 | ||
61 | /** | |
6c519bad | 62 | * batadv_nc_mesh_init - initialise coding hash table and start house keeping |
d353d8d4 MH |
63 | * @bat_priv: the bat priv with all the soft interface information |
64 | */ | |
6c519bad | 65 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
d353d8d4 | 66 | { |
95332477 | 67 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 68 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 69 | |
612d2b4f | 70 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
71 | return 0; |
72 | ||
73 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
74 | if (!bat_priv->nc.coding_hash) | |
75 | goto err; | |
76 | ||
77 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
78 | &batadv_nc_coding_hash_lock_class_key); | |
79 | ||
612d2b4f MH |
80 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
81 | if (!bat_priv->nc.decoding_hash) | |
82 | goto err; | |
83 | ||
84 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
85 | &batadv_nc_decoding_hash_lock_class_key); | |
86 | ||
d353d8d4 MH |
87 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
88 | batadv_nc_start_timer(bat_priv); | |
89 | ||
90 | return 0; | |
95332477 MH |
91 | |
92 | err: | |
93 | return -ENOMEM; | |
d353d8d4 MH |
94 | } |
95 | ||
96 | /** | |
97 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables | |
98 | * @bat_priv: the bat priv with all the soft interface information | |
99 | */ | |
100 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
101 | { | |
102 | atomic_set(&bat_priv->network_coding, 1); | |
d56b1705 | 103 | bat_priv->nc.min_tq = 200; |
95332477 | 104 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 105 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
106 | } |
107 | ||
108 | /** | |
109 | * batadv_nc_init_orig - initialise the nc fields of an orig_node | |
110 | * @orig_node: the orig_node which is going to be initialised | |
111 | */ | |
112 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
113 | { | |
114 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
115 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
116 | spin_lock_init(&orig_node->in_coding_list_lock); | |
117 | spin_lock_init(&orig_node->out_coding_list_lock); | |
118 | } | |
119 | ||
120 | /** | |
121 | * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove | |
122 | * its refcount on the orig_node | |
123 | * @rcu: rcu pointer of the nc node | |
124 | */ | |
125 | static void batadv_nc_node_free_rcu(struct rcu_head *rcu) | |
126 | { | |
127 | struct batadv_nc_node *nc_node; | |
128 | ||
129 | nc_node = container_of(rcu, struct batadv_nc_node, rcu); | |
130 | batadv_orig_node_free_ref(nc_node->orig_node); | |
131 | kfree(nc_node); | |
132 | } | |
133 | ||
134 | /** | |
135 | * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly | |
136 | * frees it | |
137 | * @nc_node: the nc node to free | |
138 | */ | |
139 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) | |
140 | { | |
141 | if (atomic_dec_and_test(&nc_node->refcount)) | |
142 | call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu); | |
143 | } | |
144 | ||
95332477 MH |
145 | /** |
146 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly | |
147 | * frees it | |
148 | * @nc_path: the nc node to free | |
149 | */ | |
150 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) | |
151 | { | |
152 | if (atomic_dec_and_test(&nc_path->refcount)) | |
153 | kfree_rcu(nc_path, rcu); | |
154 | } | |
155 | ||
156 | /** | |
157 | * batadv_nc_packet_free - frees nc packet | |
158 | * @nc_packet: the nc packet to free | |
159 | */ | |
160 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) | |
161 | { | |
162 | if (nc_packet->skb) | |
163 | kfree_skb(nc_packet->skb); | |
164 | ||
165 | batadv_nc_path_free_ref(nc_packet->nc_path); | |
166 | kfree(nc_packet); | |
167 | } | |
168 | ||
d56b1705 MH |
169 | /** |
170 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged | |
171 | * @bat_priv: the bat priv with all the soft interface information | |
172 | * @nc_node: the nc node to check | |
173 | * | |
174 | * Returns true if the entry has to be purged now, false otherwise | |
175 | */ | |
176 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
177 | struct batadv_nc_node *nc_node) | |
178 | { | |
179 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
180 | return true; | |
181 | ||
182 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
183 | } | |
184 | ||
95332477 MH |
185 | /** |
186 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out | |
187 | * @bat_priv: the bat priv with all the soft interface information | |
188 | * @nc_path: the nc path to check | |
189 | * | |
190 | * Returns true if the entry has to be purged now, false otherwise | |
191 | */ | |
192 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
193 | struct batadv_nc_path *nc_path) | |
194 | { | |
195 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
196 | return true; | |
197 | ||
198 | /* purge the path when no packets has been added for 10 times the | |
199 | * max_fwd_delay time | |
200 | */ | |
201 | return batadv_has_timed_out(nc_path->last_valid, | |
202 | bat_priv->nc.max_fwd_delay * 10); | |
203 | } | |
204 | ||
612d2b4f MH |
205 | /** |
206 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out | |
207 | * @bat_priv: the bat priv with all the soft interface information | |
208 | * @nc_path: the nc path to check | |
209 | * | |
210 | * Returns true if the entry has to be purged now, false otherwise | |
211 | */ | |
212 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
213 | struct batadv_nc_path *nc_path) | |
214 | { | |
215 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
216 | return true; | |
217 | ||
218 | /* purge the path when no packets has been added for 10 times the | |
219 | * max_buffer time | |
220 | */ | |
221 | return batadv_has_timed_out(nc_path->last_valid, | |
222 | bat_priv->nc.max_buffer_time*10); | |
223 | } | |
224 | ||
d56b1705 MH |
225 | /** |
226 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale | |
227 | * entries | |
228 | * @bat_priv: the bat priv with all the soft interface information | |
229 | * @list: list of nc nodes | |
230 | * @lock: nc node list lock | |
231 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
232 | * not. This function takes the nc node as argument and has to return | |
233 | * a boolean value: true if the entry has to be deleted, false | |
234 | * otherwise | |
235 | */ | |
236 | static void | |
237 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
238 | struct list_head *list, | |
239 | spinlock_t *lock, | |
240 | bool (*to_purge)(struct batadv_priv *, | |
241 | struct batadv_nc_node *)) | |
242 | { | |
243 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
244 | ||
245 | /* For each nc_node in list */ | |
246 | spin_lock_bh(lock); | |
247 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
248 | /* if an helper function has been passed as parameter, | |
249 | * ask it if the entry has to be purged or not | |
250 | */ | |
251 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
252 | continue; | |
253 | ||
254 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
255 | "Removing nc_node %pM -> %pM\n", | |
256 | nc_node->addr, nc_node->orig_node->orig); | |
257 | list_del_rcu(&nc_node->list); | |
258 | batadv_nc_node_free_ref(nc_node); | |
259 | } | |
260 | spin_unlock_bh(lock); | |
261 | } | |
262 | ||
263 | /** | |
264 | * batadv_nc_purge_orig - purges all nc node data attached of the given | |
265 | * originator | |
266 | * @bat_priv: the bat priv with all the soft interface information | |
267 | * @orig_node: orig_node with the nc node entries to be purged | |
268 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
269 | * not. This function takes the nc node as argument and has to return | |
270 | * a boolean value: true is the entry has to be deleted, false | |
271 | * otherwise | |
272 | */ | |
273 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
274 | struct batadv_orig_node *orig_node, | |
275 | bool (*to_purge)(struct batadv_priv *, | |
276 | struct batadv_nc_node *)) | |
277 | { | |
278 | /* Check ingoing nc_node's of this orig_node */ | |
279 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
280 | &orig_node->in_coding_list_lock, | |
281 | to_purge); | |
282 | ||
283 | /* Check outgoing nc_node's of this orig_node */ | |
284 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
285 | &orig_node->out_coding_list_lock, | |
286 | to_purge); | |
287 | } | |
288 | ||
289 | /** | |
290 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they | |
291 | * have timed out nc nodes | |
292 | * @bat_priv: the bat priv with all the soft interface information | |
293 | */ | |
294 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
295 | { | |
296 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
297 | struct hlist_head *head; | |
298 | struct batadv_orig_node *orig_node; | |
299 | uint32_t i; | |
300 | ||
301 | if (!hash) | |
302 | return; | |
303 | ||
304 | /* For each orig_node */ | |
305 | for (i = 0; i < hash->size; i++) { | |
306 | head = &hash->table[i]; | |
307 | ||
308 | rcu_read_lock(); | |
309 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
310 | batadv_nc_purge_orig(bat_priv, orig_node, | |
311 | batadv_nc_to_purge_nc_node); | |
312 | rcu_read_unlock(); | |
313 | } | |
d353d8d4 MH |
314 | } |
315 | ||
95332477 MH |
316 | /** |
317 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove | |
318 | * unused ones | |
319 | * @bat_priv: the bat priv with all the soft interface information | |
320 | * @hash: hash table containing the nc paths to check | |
321 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
322 | * not. This function takes the nc node as argument and has to return | |
323 | * a boolean value: true is the entry has to be deleted, false | |
324 | * otherwise | |
325 | */ | |
326 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
327 | struct batadv_hashtable *hash, | |
328 | bool (*to_purge)(struct batadv_priv *, | |
329 | struct batadv_nc_path *)) | |
330 | { | |
331 | struct hlist_head *head; | |
332 | struct hlist_node *node_tmp; | |
333 | struct batadv_nc_path *nc_path; | |
334 | spinlock_t *lock; /* Protects lists in hash */ | |
335 | uint32_t i; | |
336 | ||
337 | for (i = 0; i < hash->size; i++) { | |
338 | head = &hash->table[i]; | |
339 | lock = &hash->list_locks[i]; | |
340 | ||
341 | /* For each nc_path in this bin */ | |
342 | spin_lock_bh(lock); | |
343 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
344 | /* if an helper function has been passed as parameter, | |
345 | * ask it if the entry has to be purged or not | |
346 | */ | |
347 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
348 | continue; | |
349 | ||
350 | /* purging an non-empty nc_path should never happen, but | |
351 | * is observed under high CPU load. Delay the purging | |
352 | * until next iteration to allow the packet_list to be | |
353 | * emptied first. | |
354 | */ | |
355 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
356 | net_ratelimited_function(printk, | |
357 | KERN_WARNING | |
358 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
359 | nc_path->prev_hop, | |
360 | nc_path->next_hop); | |
361 | continue; | |
362 | } | |
363 | ||
364 | /* nc_path is unused, so remove it */ | |
365 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
366 | "Remove nc_path %pM -> %pM\n", | |
367 | nc_path->prev_hop, nc_path->next_hop); | |
368 | hlist_del_rcu(&nc_path->hash_entry); | |
369 | batadv_nc_path_free_ref(nc_path); | |
370 | } | |
371 | spin_unlock_bh(lock); | |
372 | } | |
373 | } | |
374 | ||
375 | /** | |
376 | * batadv_nc_hash_key_gen - computes the nc_path hash key | |
377 | * @key: buffer to hold the final hash key | |
378 | * @src: source ethernet mac address going into the hash key | |
379 | * @dst: destination ethernet mac address going into the hash key | |
380 | */ | |
381 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
382 | const char *dst) | |
383 | { | |
384 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
385 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
386 | } | |
387 | ||
388 | /** | |
389 | * batadv_nc_hash_choose - compute the hash value for an nc path | |
390 | * @data: data to hash | |
391 | * @size: size of the hash table | |
392 | * | |
393 | * Returns the selected index in the hash table for the given data. | |
394 | */ | |
395 | static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) | |
396 | { | |
397 | const struct batadv_nc_path *nc_path = data; | |
398 | uint32_t hash = 0; | |
399 | ||
400 | hash = batadv_hash_bytes(hash, &nc_path->prev_hop, | |
401 | sizeof(nc_path->prev_hop)); | |
402 | hash = batadv_hash_bytes(hash, &nc_path->next_hop, | |
403 | sizeof(nc_path->next_hop)); | |
404 | ||
405 | hash += (hash << 3); | |
406 | hash ^= (hash >> 11); | |
407 | hash += (hash << 15); | |
408 | ||
409 | return hash % size; | |
410 | } | |
411 | ||
412 | /** | |
413 | * batadv_nc_hash_compare - comparing function used in the network coding hash | |
414 | * tables | |
415 | * @node: node in the local table | |
416 | * @data2: second object to compare the node to | |
417 | * | |
418 | * Returns 1 if the two entry are the same, 0 otherwise | |
419 | */ | |
420 | static int batadv_nc_hash_compare(const struct hlist_node *node, | |
421 | const void *data2) | |
422 | { | |
423 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
424 | ||
425 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
426 | nc_path2 = data2; | |
427 | ||
428 | /* Return 1 if the two keys are identical */ | |
429 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, | |
430 | sizeof(nc_path1->prev_hop)) != 0) | |
431 | return 0; | |
432 | ||
433 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, | |
434 | sizeof(nc_path1->next_hop)) != 0) | |
435 | return 0; | |
436 | ||
437 | return 1; | |
438 | } | |
439 | ||
440 | /** | |
441 | * batadv_nc_hash_find - search for an existing nc path and return it | |
442 | * @hash: hash table containing the nc path | |
443 | * @data: search key | |
444 | * | |
445 | * Returns the nc_path if found, NULL otherwise. | |
446 | */ | |
447 | static struct batadv_nc_path * | |
448 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
449 | void *data) | |
450 | { | |
451 | struct hlist_head *head; | |
452 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
453 | int index; | |
454 | ||
455 | if (!hash) | |
456 | return NULL; | |
457 | ||
458 | index = batadv_nc_hash_choose(data, hash->size); | |
459 | head = &hash->table[index]; | |
460 | ||
461 | rcu_read_lock(); | |
462 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
463 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
464 | continue; | |
465 | ||
466 | if (!atomic_inc_not_zero(&nc_path->refcount)) | |
467 | continue; | |
468 | ||
469 | nc_path_tmp = nc_path; | |
470 | break; | |
471 | } | |
472 | rcu_read_unlock(); | |
473 | ||
474 | return nc_path_tmp; | |
475 | } | |
476 | ||
477 | /** | |
478 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct | |
479 | * @nc_packet: the nc packet to send | |
480 | */ | |
481 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
482 | { | |
483 | batadv_send_skb_packet(nc_packet->skb, | |
484 | nc_packet->neigh_node->if_incoming, | |
485 | nc_packet->nc_path->next_hop); | |
486 | nc_packet->skb = NULL; | |
487 | batadv_nc_packet_free(nc_packet); | |
488 | } | |
489 | ||
612d2b4f MH |
490 | /** |
491 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. | |
492 | * @bat_priv: the bat priv with all the soft interface information | |
493 | * @nc_path: the nc path the packet belongs to | |
494 | * @nc_packet: the nc packet to be checked | |
495 | * | |
496 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
497 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
498 | * queue. Has to be called with the appropriate locks. | |
499 | * | |
500 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
501 | * yet and true otherwise. | |
502 | */ | |
503 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
504 | struct batadv_nc_path *nc_path, | |
505 | struct batadv_nc_packet *nc_packet) | |
506 | { | |
507 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
508 | bool res = false; | |
509 | ||
510 | /* Packets are added to tail, so the remaining packets did not time | |
511 | * out and we can stop processing the current queue | |
512 | */ | |
513 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
514 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
515 | goto out; | |
516 | ||
517 | /* purge nc packet */ | |
518 | list_del(&nc_packet->list); | |
519 | batadv_nc_packet_free(nc_packet); | |
520 | ||
521 | res = true; | |
522 | ||
523 | out: | |
524 | return res; | |
525 | } | |
526 | ||
95332477 MH |
527 | /** |
528 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. | |
529 | * @bat_priv: the bat priv with all the soft interface information | |
530 | * @nc_path: the nc path the packet belongs to | |
531 | * @nc_packet: the nc packet to be checked | |
532 | * | |
533 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
534 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
535 | * queue. Has to be called with the appropriate locks. | |
536 | * | |
537 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
538 | * yet and true otherwise. | |
539 | */ | |
540 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
541 | struct batadv_nc_path *nc_path, | |
542 | struct batadv_nc_packet *nc_packet) | |
543 | { | |
544 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
545 | ||
546 | /* Packets are added to tail, so the remaining packets did not time | |
547 | * out and we can stop processing the current queue | |
548 | */ | |
549 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
550 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
551 | return false; | |
552 | ||
553 | /* Send packet */ | |
554 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
555 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
556 | nc_packet->skb->len + ETH_HLEN); | |
557 | list_del(&nc_packet->list); | |
558 | batadv_nc_send_packet(nc_packet); | |
559 | ||
560 | return true; | |
561 | } | |
562 | ||
563 | /** | |
564 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out | |
565 | * nc packets | |
566 | * @bat_priv: the bat priv with all the soft interface information | |
567 | * @hash: to be processed hash table | |
568 | * @process_fn: Function called to process given nc packet. Should return true | |
569 | * to encourage this function to proceed with the next packet. | |
570 | * Otherwise the rest of the current queue is skipped. | |
571 | */ | |
572 | static void | |
573 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
574 | struct batadv_hashtable *hash, | |
575 | bool (*process_fn)(struct batadv_priv *, | |
576 | struct batadv_nc_path *, | |
577 | struct batadv_nc_packet *)) | |
578 | { | |
579 | struct hlist_head *head; | |
580 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
581 | struct batadv_nc_path *nc_path; | |
582 | bool ret; | |
583 | int i; | |
584 | ||
585 | if (!hash) | |
586 | return; | |
587 | ||
588 | /* Loop hash table bins */ | |
589 | for (i = 0; i < hash->size; i++) { | |
590 | head = &hash->table[i]; | |
591 | ||
592 | /* Loop coding paths */ | |
593 | rcu_read_lock(); | |
594 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
595 | /* Loop packets */ | |
596 | spin_lock_bh(&nc_path->packet_list_lock); | |
597 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
598 | &nc_path->packet_list, list) { | |
599 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
600 | if (!ret) | |
601 | break; | |
602 | } | |
603 | spin_unlock_bh(&nc_path->packet_list_lock); | |
604 | } | |
605 | rcu_read_unlock(); | |
606 | } | |
607 | } | |
608 | ||
d353d8d4 MH |
609 | /** |
610 | * batadv_nc_worker - periodic task for house keeping related to network coding | |
611 | * @work: kernel work struct | |
612 | */ | |
613 | static void batadv_nc_worker(struct work_struct *work) | |
614 | { | |
615 | struct delayed_work *delayed_work; | |
616 | struct batadv_priv_nc *priv_nc; | |
617 | struct batadv_priv *bat_priv; | |
95332477 | 618 | unsigned long timeout; |
d353d8d4 MH |
619 | |
620 | delayed_work = container_of(work, struct delayed_work, work); | |
621 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); | |
622 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
623 | ||
d56b1705 | 624 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
625 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
626 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
627 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
628 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
629 | |
630 | timeout = bat_priv->nc.max_fwd_delay; | |
631 | ||
632 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
633 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
634 | batadv_nc_fwd_flush); | |
635 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
636 | } | |
d56b1705 | 637 | |
612d2b4f MH |
638 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
639 | bat_priv->nc.max_buffer_time)) { | |
640 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
641 | batadv_nc_sniffed_purge); | |
642 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
643 | } | |
644 | ||
d353d8d4 MH |
645 | /* Schedule a new check */ |
646 | batadv_nc_start_timer(bat_priv); | |
647 | } | |
648 | ||
d56b1705 MH |
649 | /** |
650 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for | |
651 | * coding or not | |
652 | * @bat_priv: the bat priv with all the soft interface information | |
653 | * @orig_node: neighboring orig node which may be used as nc candidate | |
654 | * @ogm_packet: incoming ogm packet also used for the checks | |
655 | * | |
656 | * Returns true if: | |
657 | * 1) The OGM must have the most recent sequence number. | |
658 | * 2) The TTL must be decremented by one and only one. | |
659 | * 3) The OGM must be received from the first hop from orig_node. | |
660 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
661 | */ | |
662 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
663 | struct batadv_orig_node *orig_node, | |
664 | struct batadv_ogm_packet *ogm_packet) | |
665 | { | |
e6a0b495 | 666 | if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno)) |
d56b1705 MH |
667 | return false; |
668 | if (orig_node->last_ttl != ogm_packet->header.ttl + 1) | |
669 | return false; | |
670 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
671 | return false; | |
672 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
673 | return false; | |
674 | ||
675 | return true; | |
676 | } | |
677 | ||
678 | /** | |
679 | * batadv_nc_find_nc_node - search for an existing nc node and return it | |
680 | * @orig_node: orig node originating the ogm packet | |
681 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
682 | * (can be equal to orig_node) | |
683 | * @in_coding: traverse incoming or outgoing network coding list | |
684 | * | |
685 | * Returns the nc_node if found, NULL otherwise. | |
686 | */ | |
687 | static struct batadv_nc_node | |
688 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
689 | struct batadv_orig_node *orig_neigh_node, | |
690 | bool in_coding) | |
691 | { | |
692 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
693 | struct list_head *list; | |
694 | ||
695 | if (in_coding) | |
696 | list = &orig_neigh_node->in_coding_list; | |
697 | else | |
698 | list = &orig_neigh_node->out_coding_list; | |
699 | ||
700 | /* Traverse list of nc_nodes to orig_node */ | |
701 | rcu_read_lock(); | |
702 | list_for_each_entry_rcu(nc_node, list, list) { | |
703 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
704 | continue; | |
705 | ||
706 | if (!atomic_inc_not_zero(&nc_node->refcount)) | |
707 | continue; | |
708 | ||
709 | /* Found a match */ | |
710 | nc_node_out = nc_node; | |
711 | break; | |
712 | } | |
713 | rcu_read_unlock(); | |
714 | ||
715 | return nc_node_out; | |
716 | } | |
717 | ||
718 | /** | |
719 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was | |
720 | * not found | |
721 | * @bat_priv: the bat priv with all the soft interface information | |
722 | * @orig_node: orig node originating the ogm packet | |
723 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
724 | * (can be equal to orig_node) | |
725 | * @in_coding: traverse incoming or outgoing network coding list | |
726 | * | |
727 | * Returns the nc_node if found or created, NULL in case of an error. | |
728 | */ | |
729 | static struct batadv_nc_node | |
730 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
731 | struct batadv_orig_node *orig_node, | |
732 | struct batadv_orig_node *orig_neigh_node, | |
733 | bool in_coding) | |
734 | { | |
735 | struct batadv_nc_node *nc_node; | |
736 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
737 | struct list_head *list; | |
738 | ||
739 | /* Check if nc_node is already added */ | |
740 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
741 | ||
742 | /* Node found */ | |
743 | if (nc_node) | |
744 | return nc_node; | |
745 | ||
746 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
747 | if (!nc_node) | |
748 | return NULL; | |
749 | ||
750 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) | |
751 | goto free; | |
752 | ||
753 | /* Initialize nc_node */ | |
754 | INIT_LIST_HEAD(&nc_node->list); | |
755 | memcpy(nc_node->addr, orig_node->orig, ETH_ALEN); | |
756 | nc_node->orig_node = orig_neigh_node; | |
757 | atomic_set(&nc_node->refcount, 2); | |
758 | ||
759 | /* Select ingoing or outgoing coding node */ | |
760 | if (in_coding) { | |
761 | lock = &orig_neigh_node->in_coding_list_lock; | |
762 | list = &orig_neigh_node->in_coding_list; | |
763 | } else { | |
764 | lock = &orig_neigh_node->out_coding_list_lock; | |
765 | list = &orig_neigh_node->out_coding_list; | |
766 | } | |
767 | ||
768 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", | |
769 | nc_node->addr, nc_node->orig_node->orig); | |
770 | ||
771 | /* Add nc_node to orig_node */ | |
772 | spin_lock_bh(lock); | |
773 | list_add_tail_rcu(&nc_node->list, list); | |
774 | spin_unlock_bh(lock); | |
775 | ||
776 | return nc_node; | |
777 | ||
778 | free: | |
779 | kfree(nc_node); | |
780 | return NULL; | |
781 | } | |
782 | ||
783 | /** | |
784 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs | |
785 | * (best called on incoming OGMs) | |
786 | * @bat_priv: the bat priv with all the soft interface information | |
787 | * @orig_node: orig node originating the ogm packet | |
788 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
789 | * (can be equal to orig_node) | |
790 | * @ogm_packet: incoming ogm packet | |
791 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
792 | */ | |
793 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
794 | struct batadv_orig_node *orig_node, | |
795 | struct batadv_orig_node *orig_neigh_node, | |
796 | struct batadv_ogm_packet *ogm_packet, | |
797 | int is_single_hop_neigh) | |
798 | { | |
799 | struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL; | |
800 | ||
801 | /* Check if network coding is enabled */ | |
802 | if (!atomic_read(&bat_priv->network_coding)) | |
803 | goto out; | |
804 | ||
805 | /* accept ogms from 'good' neighbors and single hop neighbors */ | |
806 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
807 | !is_single_hop_neigh) | |
808 | goto out; | |
809 | ||
810 | /* Add orig_node as in_nc_node on hop */ | |
811 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
812 | orig_neigh_node, true); | |
813 | if (!in_nc_node) | |
814 | goto out; | |
815 | ||
816 | in_nc_node->last_seen = jiffies; | |
817 | ||
818 | /* Add hop as out_nc_node on orig_node */ | |
819 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
820 | orig_node, false); | |
821 | if (!out_nc_node) | |
822 | goto out; | |
823 | ||
824 | out_nc_node->last_seen = jiffies; | |
825 | ||
826 | out: | |
827 | if (in_nc_node) | |
828 | batadv_nc_node_free_ref(in_nc_node); | |
829 | if (out_nc_node) | |
830 | batadv_nc_node_free_ref(out_nc_node); | |
831 | } | |
832 | ||
95332477 MH |
833 | /** |
834 | * batadv_nc_get_path - get existing nc_path or allocate a new one | |
835 | * @bat_priv: the bat priv with all the soft interface information | |
836 | * @hash: hash table containing the nc path | |
837 | * @src: ethernet source address - first half of the nc path search key | |
838 | * @dst: ethernet destination address - second half of the nc path search key | |
839 | * | |
840 | * Returns pointer to nc_path if the path was found or created, returns NULL | |
841 | * on error. | |
842 | */ | |
843 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
844 | struct batadv_hashtable *hash, | |
845 | uint8_t *src, | |
846 | uint8_t *dst) | |
847 | { | |
848 | int hash_added; | |
849 | struct batadv_nc_path *nc_path, nc_path_key; | |
850 | ||
851 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
852 | ||
853 | /* Search for existing nc_path */ | |
854 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
855 | ||
856 | if (nc_path) { | |
857 | /* Set timestamp to delay removal of nc_path */ | |
858 | nc_path->last_valid = jiffies; | |
859 | return nc_path; | |
860 | } | |
861 | ||
862 | /* No existing nc_path was found; create a new */ | |
863 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
864 | ||
865 | if (!nc_path) | |
866 | return NULL; | |
867 | ||
868 | /* Initialize nc_path */ | |
869 | INIT_LIST_HEAD(&nc_path->packet_list); | |
870 | spin_lock_init(&nc_path->packet_list_lock); | |
871 | atomic_set(&nc_path->refcount, 2); | |
872 | nc_path->last_valid = jiffies; | |
873 | memcpy(nc_path->next_hop, dst, ETH_ALEN); | |
874 | memcpy(nc_path->prev_hop, src, ETH_ALEN); | |
875 | ||
876 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
877 | nc_path->prev_hop, | |
878 | nc_path->next_hop); | |
879 | ||
880 | /* Add nc_path to hash table */ | |
881 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, | |
882 | batadv_nc_hash_choose, &nc_path_key, | |
883 | &nc_path->hash_entry); | |
884 | ||
885 | if (hash_added < 0) { | |
886 | kfree(nc_path); | |
887 | return NULL; | |
888 | } | |
889 | ||
890 | return nc_path; | |
891 | } | |
892 | ||
3c12de9a MH |
893 | /** |
894 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair | |
895 | * selection of a receiver with slightly lower TQ than the other | |
896 | * @tq: to be weighted tq value | |
897 | */ | |
898 | static uint8_t batadv_nc_random_weight_tq(uint8_t tq) | |
899 | { | |
900 | uint8_t rand_val, rand_tq; | |
901 | ||
902 | get_random_bytes(&rand_val, sizeof(rand_val)); | |
903 | ||
904 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ | |
905 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); | |
906 | ||
907 | /* normalize the randomized packet loss */ | |
908 | rand_tq /= BATADV_TQ_MAX_VALUE; | |
909 | ||
910 | /* convert to (randomized) estimated tq again */ | |
911 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
912 | } | |
913 | ||
914 | /** | |
915 | * batadv_nc_memxor - XOR destination with source | |
916 | * @dst: byte array to XOR into | |
917 | * @src: byte array to XOR from | |
918 | * @len: length of destination array | |
919 | */ | |
920 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
921 | { | |
922 | unsigned int i; | |
923 | ||
924 | for (i = 0; i < len; ++i) | |
925 | dst[i] ^= src[i]; | |
926 | } | |
927 | ||
928 | /** | |
929 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet | |
930 | * into a coded_packet and send it | |
931 | * @bat_priv: the bat priv with all the soft interface information | |
932 | * @skb: data skb to forward | |
933 | * @ethhdr: pointer to the ethernet header inside the skb | |
934 | * @nc_packet: structure containing the packet to the skb can be coded with | |
935 | * @neigh_node: next hop to forward packet to | |
936 | * | |
937 | * Returns true if both packets are consumed, false otherwise. | |
938 | */ | |
939 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
940 | struct sk_buff *skb, | |
941 | struct ethhdr *ethhdr, | |
942 | struct batadv_nc_packet *nc_packet, | |
943 | struct batadv_neigh_node *neigh_node) | |
944 | { | |
945 | uint8_t tq_weighted_neigh, tq_weighted_coding; | |
946 | struct sk_buff *skb_dest, *skb_src; | |
947 | struct batadv_unicast_packet *packet1; | |
948 | struct batadv_unicast_packet *packet2; | |
949 | struct batadv_coded_packet *coded_packet; | |
950 | struct batadv_neigh_node *neigh_tmp, *router_neigh; | |
951 | struct batadv_neigh_node *router_coding = NULL; | |
952 | uint8_t *first_source, *first_dest, *second_source, *second_dest; | |
953 | __be32 packet_id1, packet_id2; | |
954 | size_t count; | |
955 | bool res = false; | |
956 | int coding_len; | |
957 | int unicast_size = sizeof(*packet1); | |
958 | int coded_size = sizeof(*coded_packet); | |
959 | int header_add = coded_size - unicast_size; | |
960 | ||
961 | router_neigh = batadv_orig_node_get_router(neigh_node->orig_node); | |
962 | if (!router_neigh) | |
963 | goto out; | |
964 | ||
965 | neigh_tmp = nc_packet->neigh_node; | |
966 | router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node); | |
967 | if (!router_coding) | |
968 | goto out; | |
969 | ||
970 | tq_weighted_neigh = batadv_nc_random_weight_tq(router_neigh->tq_avg); | |
971 | tq_weighted_coding = batadv_nc_random_weight_tq(router_coding->tq_avg); | |
972 | ||
973 | /* Select one destination for the MAC-header dst-field based on | |
974 | * weighted TQ-values. | |
975 | */ | |
976 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
977 | /* Destination from nc_packet is selected for MAC-header */ | |
978 | first_dest = nc_packet->nc_path->next_hop; | |
979 | first_source = nc_packet->nc_path->prev_hop; | |
980 | second_dest = neigh_node->addr; | |
981 | second_source = ethhdr->h_source; | |
982 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
983 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
984 | packet_id1 = nc_packet->packet_id; | |
985 | packet_id2 = batadv_skb_crc32(skb, | |
986 | skb->data + sizeof(*packet2)); | |
987 | } else { | |
988 | /* Destination for skb is selected for MAC-header */ | |
989 | first_dest = neigh_node->addr; | |
990 | first_source = ethhdr->h_source; | |
991 | second_dest = nc_packet->nc_path->next_hop; | |
992 | second_source = nc_packet->nc_path->prev_hop; | |
993 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
994 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
995 | packet_id1 = batadv_skb_crc32(skb, | |
996 | skb->data + sizeof(*packet1)); | |
997 | packet_id2 = nc_packet->packet_id; | |
998 | } | |
999 | ||
1000 | /* Instead of zero padding the smallest data buffer, we | |
1001 | * code into the largest. | |
1002 | */ | |
1003 | if (skb->len <= nc_packet->skb->len) { | |
1004 | skb_dest = nc_packet->skb; | |
1005 | skb_src = skb; | |
1006 | } else { | |
1007 | skb_dest = skb; | |
1008 | skb_src = nc_packet->skb; | |
1009 | } | |
1010 | ||
1011 | /* coding_len is used when decoding the packet shorter packet */ | |
1012 | coding_len = skb_src->len - unicast_size; | |
1013 | ||
1014 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1015 | goto out; | |
1016 | ||
1017 | skb_push(skb_dest, header_add); | |
1018 | ||
1019 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1020 | skb_reset_mac_header(skb_dest); | |
1021 | ||
1022 | coded_packet->header.packet_type = BATADV_CODED; | |
1023 | coded_packet->header.version = BATADV_COMPAT_VERSION; | |
1024 | coded_packet->header.ttl = packet1->header.ttl; | |
1025 | ||
1026 | /* Info about first unicast packet */ | |
1027 | memcpy(coded_packet->first_source, first_source, ETH_ALEN); | |
1028 | memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN); | |
1029 | coded_packet->first_crc = packet_id1; | |
1030 | coded_packet->first_ttvn = packet1->ttvn; | |
1031 | ||
1032 | /* Info about second unicast packet */ | |
1033 | memcpy(coded_packet->second_dest, second_dest, ETH_ALEN); | |
1034 | memcpy(coded_packet->second_source, second_source, ETH_ALEN); | |
1035 | memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN); | |
1036 | coded_packet->second_crc = packet_id2; | |
1037 | coded_packet->second_ttl = packet2->header.ttl; | |
1038 | coded_packet->second_ttvn = packet2->ttvn; | |
1039 | coded_packet->coded_len = htons(coding_len); | |
1040 | ||
1041 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1042 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1043 | skb_src->data + unicast_size, coding_len); | |
1044 | ||
1045 | /* Update counters accordingly */ | |
1046 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1047 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1048 | /* Both packets are recoded */ | |
1049 | count = skb_src->len + ETH_HLEN; | |
1050 | count += skb_dest->len + ETH_HLEN; | |
1051 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1052 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1053 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1054 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1055 | /* Both packets are newly coded */ | |
1056 | count = skb_src->len + ETH_HLEN; | |
1057 | count += skb_dest->len + ETH_HLEN; | |
1058 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1059 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1060 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1061 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1062 | /* skb_src recoded and skb_dest is newly coded */ | |
1063 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1064 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1065 | skb_src->len + ETH_HLEN); | |
1066 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1067 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1068 | skb_dest->len + ETH_HLEN); | |
1069 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1070 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1071 | /* skb_src is newly coded and skb_dest is recoded */ | |
1072 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1073 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1074 | skb_src->len + ETH_HLEN); | |
1075 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1076 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1077 | skb_dest->len + ETH_HLEN); | |
1078 | } | |
1079 | ||
1080 | /* skb_src is now coded into skb_dest, so free it */ | |
1081 | kfree_skb(skb_src); | |
1082 | ||
1083 | /* avoid duplicate free of skb from nc_packet */ | |
1084 | nc_packet->skb = NULL; | |
1085 | batadv_nc_packet_free(nc_packet); | |
1086 | ||
1087 | /* Send the coded packet and return true */ | |
1088 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); | |
1089 | res = true; | |
1090 | out: | |
1091 | if (router_neigh) | |
1092 | batadv_neigh_node_free_ref(router_neigh); | |
1093 | if (router_coding) | |
1094 | batadv_neigh_node_free_ref(router_coding); | |
1095 | return res; | |
1096 | } | |
1097 | ||
1098 | /** | |
1099 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. | |
1100 | * @skb: data skb to forward | |
1101 | * @dst: destination mac address of the other skb to code with | |
1102 | * @src: source mac address of skb | |
1103 | * | |
1104 | * Whenever we network code a packet we have to check whether we received it in | |
1105 | * a network coded form. If so, we may not be able to use it for coding because | |
1106 | * some neighbors may also have received (overheard) the packet in the network | |
1107 | * coded form without being able to decode it. It is hard to know which of the | |
1108 | * neighboring nodes was able to decode the packet, therefore we can only | |
1109 | * re-code the packet if the source of the previous encoded packet is involved. | |
1110 | * Since the source encoded the packet we can be certain it has all necessary | |
1111 | * decode information. | |
1112 | * | |
1113 | * Returns true if coding of a decoded packet is allowed. | |
1114 | */ | |
1115 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, | |
1116 | uint8_t *dst, uint8_t *src) | |
1117 | { | |
1118 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1119 | return false; | |
1120 | else | |
1121 | return true; | |
1122 | } | |
1123 | ||
1124 | /** | |
1125 | * batadv_nc_path_search - Find the coding path matching in_nc_node and | |
1126 | * out_nc_node to retrieve a buffered packet that can be used for coding. | |
1127 | * @bat_priv: the bat priv with all the soft interface information | |
1128 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1129 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1130 | * @skb: data skb to forward | |
1131 | * @eth_dst: next hop mac address of skb | |
1132 | * | |
1133 | * Returns true if coding of a decoded skb is allowed. | |
1134 | */ | |
1135 | static struct batadv_nc_packet * | |
1136 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1137 | struct batadv_nc_node *in_nc_node, | |
1138 | struct batadv_nc_node *out_nc_node, | |
1139 | struct sk_buff *skb, | |
1140 | uint8_t *eth_dst) | |
1141 | { | |
1142 | struct batadv_nc_path *nc_path, nc_path_key; | |
1143 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1144 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1145 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1146 | int idx; | |
1147 | ||
1148 | if (!hash) | |
1149 | return NULL; | |
1150 | ||
1151 | /* Create almost path key */ | |
1152 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1153 | out_nc_node->addr); | |
1154 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1155 | ||
1156 | /* Check for coding opportunities in this nc_path */ | |
1157 | rcu_read_lock(); | |
1158 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1159 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1160 | continue; | |
1161 | ||
1162 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1163 | continue; | |
1164 | ||
1165 | spin_lock_bh(&nc_path->packet_list_lock); | |
1166 | if (list_empty(&nc_path->packet_list)) { | |
1167 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1168 | continue; | |
1169 | } | |
1170 | ||
1171 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1172 | &nc_path->packet_list, list) { | |
1173 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1174 | eth_dst, | |
1175 | in_nc_node->addr)) | |
1176 | continue; | |
1177 | ||
1178 | /* Coding opportunity is found! */ | |
1179 | list_del(&nc_packet->list); | |
1180 | nc_packet_out = nc_packet; | |
1181 | break; | |
1182 | } | |
1183 | ||
1184 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1185 | break; | |
1186 | } | |
1187 | rcu_read_unlock(); | |
1188 | ||
1189 | return nc_packet_out; | |
1190 | } | |
1191 | ||
1192 | /** | |
1193 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the | |
1194 | * skb's sender (may be equal to the originator). | |
1195 | * @bat_priv: the bat priv with all the soft interface information | |
1196 | * @skb: data skb to forward | |
1197 | * @eth_dst: next hop mac address of skb | |
1198 | * @eth_src: source mac address of skb | |
1199 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1200 | * | |
1201 | * Returns an nc packet if a suitable coding packet was found, NULL otherwise. | |
1202 | */ | |
1203 | static struct batadv_nc_packet * | |
1204 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1205 | struct sk_buff *skb, | |
1206 | uint8_t *eth_dst, | |
1207 | uint8_t *eth_src, | |
1208 | struct batadv_nc_node *in_nc_node) | |
1209 | { | |
1210 | struct batadv_orig_node *orig_node; | |
1211 | struct batadv_nc_node *out_nc_node; | |
1212 | struct batadv_nc_packet *nc_packet = NULL; | |
1213 | ||
1214 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1215 | if (!orig_node) | |
1216 | return NULL; | |
1217 | ||
1218 | rcu_read_lock(); | |
1219 | list_for_each_entry_rcu(out_nc_node, | |
1220 | &orig_node->out_coding_list, list) { | |
1221 | /* Check if the skb is decoded and if recoding is possible */ | |
1222 | if (!batadv_nc_skb_coding_possible(skb, | |
1223 | out_nc_node->addr, eth_src)) | |
1224 | continue; | |
1225 | ||
1226 | /* Search for an opportunity in this nc_path */ | |
1227 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1228 | out_nc_node, skb, eth_dst); | |
1229 | if (nc_packet) | |
1230 | break; | |
1231 | } | |
1232 | rcu_read_unlock(); | |
1233 | ||
1234 | batadv_orig_node_free_ref(orig_node); | |
1235 | return nc_packet; | |
1236 | } | |
1237 | ||
612d2b4f MH |
1238 | /** |
1239 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the | |
1240 | * unicast skb before it is stored for use in later decoding | |
1241 | * @bat_priv: the bat priv with all the soft interface information | |
1242 | * @skb: data skb to store | |
1243 | * @eth_dst_new: new destination mac address of skb | |
1244 | */ | |
1245 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1246 | struct sk_buff *skb, | |
1247 | uint8_t *eth_dst_new) | |
1248 | { | |
1249 | struct ethhdr *ethhdr; | |
1250 | ||
1251 | /* Copy skb header to change the mac header */ | |
1252 | skb = pskb_copy(skb, GFP_ATOMIC); | |
1253 | if (!skb) | |
1254 | return; | |
1255 | ||
1256 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1257 | ethhdr = eth_hdr(skb); |
612d2b4f MH |
1258 | memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN); |
1259 | memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN); | |
1260 | ||
1261 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1262 | skb_push(skb, ETH_HLEN); | |
1263 | ||
1264 | /* Add the packet to the decoding packet pool */ | |
1265 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1266 | ||
1267 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1268 | * our ref | |
1269 | */ | |
1270 | kfree_skb(skb); | |
1271 | } | |
1272 | ||
3c12de9a MH |
1273 | /** |
1274 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. | |
1275 | * @skb: data skb to forward | |
1276 | * @neigh_node: next hop to forward packet to | |
1277 | * @ethhdr: pointer to the ethernet header inside the skb | |
1278 | * | |
1279 | * Loops through list of neighboring nodes the next hop has a good connection to | |
1280 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our | |
1281 | * next hop that potentially sent a packet which our next hop also received | |
1282 | * (overheard) and has stored for later decoding. | |
1283 | * | |
1284 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1285 | */ | |
1286 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1287 | struct batadv_neigh_node *neigh_node, | |
1288 | struct ethhdr *ethhdr) | |
1289 | { | |
1290 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1291 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1292 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1293 | struct batadv_nc_node *nc_node; | |
1294 | struct batadv_nc_packet *nc_packet = NULL; | |
1295 | ||
1296 | rcu_read_lock(); | |
1297 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1298 | /* Search for coding opportunity with this in_nc_node */ | |
1299 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1300 | neigh_node->addr, | |
1301 | ethhdr->h_source, nc_node); | |
1302 | ||
1303 | /* Opportunity was found, so stop searching */ | |
1304 | if (nc_packet) | |
1305 | break; | |
1306 | } | |
1307 | rcu_read_unlock(); | |
1308 | ||
1309 | if (!nc_packet) | |
1310 | return false; | |
1311 | ||
612d2b4f MH |
1312 | /* Save packets for later decoding */ |
1313 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1314 | neigh_node->addr); | |
1315 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1316 | nc_packet->neigh_node->addr); | |
1317 | ||
3c12de9a MH |
1318 | /* Code and send packets */ |
1319 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1320 | neigh_node)) | |
1321 | return true; | |
1322 | ||
1323 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1324 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1325 | * by the calling function. | |
1326 | */ | |
1327 | batadv_nc_send_packet(nc_packet); | |
1328 | return false; | |
1329 | } | |
1330 | ||
95332477 MH |
1331 | /** |
1332 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding | |
1333 | * @skb: skb to add to path | |
1334 | * @nc_path: path to add skb to | |
1335 | * @neigh_node: next hop to forward packet to | |
1336 | * @packet_id: checksum to identify packet | |
1337 | * | |
1338 | * Returns true if the packet was buffered or false in case of an error. | |
1339 | */ | |
1340 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1341 | struct batadv_nc_path *nc_path, | |
1342 | struct batadv_neigh_node *neigh_node, | |
1343 | __be32 packet_id) | |
1344 | { | |
1345 | struct batadv_nc_packet *nc_packet; | |
1346 | ||
1347 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1348 | if (!nc_packet) | |
1349 | return false; | |
1350 | ||
1351 | /* Initialize nc_packet */ | |
1352 | nc_packet->timestamp = jiffies; | |
1353 | nc_packet->packet_id = packet_id; | |
1354 | nc_packet->skb = skb; | |
1355 | nc_packet->neigh_node = neigh_node; | |
1356 | nc_packet->nc_path = nc_path; | |
1357 | ||
1358 | /* Add coding packet to list */ | |
1359 | spin_lock_bh(&nc_path->packet_list_lock); | |
1360 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1361 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1362 | ||
1363 | return true; | |
1364 | } | |
1365 | ||
1366 | /** | |
1367 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet | |
1368 | * buffer | |
1369 | * @skb: data skb to forward | |
1370 | * @neigh_node: next hop to forward packet to | |
95332477 MH |
1371 | * |
1372 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1373 | */ | |
1374 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
e91ecfc6 | 1375 | struct batadv_neigh_node *neigh_node) |
95332477 MH |
1376 | { |
1377 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1378 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1379 | struct batadv_unicast_packet *packet; | |
1380 | struct batadv_nc_path *nc_path; | |
e91ecfc6 | 1381 | struct ethhdr *ethhdr = eth_hdr(skb); |
95332477 MH |
1382 | __be32 packet_id; |
1383 | u8 *payload; | |
1384 | ||
1385 | /* Check if network coding is enabled */ | |
1386 | if (!atomic_read(&bat_priv->network_coding)) | |
1387 | goto out; | |
1388 | ||
1389 | /* We only handle unicast packets */ | |
1390 | payload = skb_network_header(skb); | |
1391 | packet = (struct batadv_unicast_packet *)payload; | |
1392 | if (packet->header.packet_type != BATADV_UNICAST) | |
1393 | goto out; | |
1394 | ||
3c12de9a MH |
1395 | /* Try to find a coding opportunity and send the skb if one is found */ |
1396 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1397 | return true; | |
1398 | ||
95332477 MH |
1399 | /* Find or create a nc_path for this src-dst pair */ |
1400 | nc_path = batadv_nc_get_path(bat_priv, | |
1401 | bat_priv->nc.coding_hash, | |
1402 | ethhdr->h_source, | |
1403 | neigh_node->addr); | |
1404 | ||
1405 | if (!nc_path) | |
1406 | goto out; | |
1407 | ||
1408 | /* Add skb to nc_path */ | |
1409 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1410 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1411 | goto free_nc_path; | |
1412 | ||
1413 | /* Packet is consumed */ | |
1414 | return true; | |
1415 | ||
1416 | free_nc_path: | |
1417 | batadv_nc_path_free_ref(nc_path); | |
1418 | out: | |
1419 | /* Packet is not consumed */ | |
1420 | return false; | |
1421 | } | |
1422 | ||
612d2b4f MH |
1423 | /** |
1424 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used | |
1425 | * when decoding coded packets | |
1426 | * @bat_priv: the bat priv with all the soft interface information | |
1427 | * @skb: data skb to store | |
1428 | */ | |
1429 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1430 | struct sk_buff *skb) | |
1431 | { | |
1432 | struct batadv_unicast_packet *packet; | |
1433 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1434 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1435 | __be32 packet_id; |
1436 | u8 *payload; | |
1437 | ||
1438 | /* Check if network coding is enabled */ | |
1439 | if (!atomic_read(&bat_priv->network_coding)) | |
1440 | goto out; | |
1441 | ||
1442 | /* Check for supported packet type */ | |
1443 | payload = skb_network_header(skb); | |
1444 | packet = (struct batadv_unicast_packet *)payload; | |
1445 | if (packet->header.packet_type != BATADV_UNICAST) | |
1446 | goto out; | |
1447 | ||
1448 | /* Find existing nc_path or create a new */ | |
1449 | nc_path = batadv_nc_get_path(bat_priv, | |
1450 | bat_priv->nc.decoding_hash, | |
1451 | ethhdr->h_source, | |
1452 | ethhdr->h_dest); | |
1453 | ||
1454 | if (!nc_path) | |
1455 | goto out; | |
1456 | ||
1457 | /* Clone skb and adjust skb->data to point at batman header */ | |
1458 | skb = skb_clone(skb, GFP_ATOMIC); | |
1459 | if (unlikely(!skb)) | |
1460 | goto free_nc_path; | |
1461 | ||
1462 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1463 | goto free_skb; | |
1464 | ||
1465 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1466 | goto free_skb; | |
1467 | ||
1468 | /* Add skb to nc_path */ | |
1469 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1470 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1471 | goto free_skb; | |
1472 | ||
1473 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1474 | return; | |
1475 | ||
1476 | free_skb: | |
1477 | kfree_skb(skb); | |
1478 | free_nc_path: | |
1479 | batadv_nc_path_free_ref(nc_path); | |
1480 | out: | |
1481 | return; | |
1482 | } | |
1483 | ||
1484 | /** | |
1485 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet | |
1486 | * should be saved in the decoding buffer and, if so, store it there | |
1487 | * @bat_priv: the bat priv with all the soft interface information | |
1488 | * @skb: unicast skb to store | |
1489 | */ | |
1490 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1491 | struct sk_buff *skb) | |
1492 | { | |
7ed4be95 | 1493 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1494 | |
6e0895c2 | 1495 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1496 | return; |
1497 | ||
1498 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1499 | skb_push(skb, ETH_HLEN); | |
1500 | ||
1501 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1502 | } | |
1503 | ||
2df5278b MH |
1504 | /** |
1505 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored | |
1506 | * in nc_packet | |
6e0895c2 | 1507 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1508 | * @skb: unicast skb to decode |
1509 | * @nc_packet: decode data needed to decode the skb | |
1510 | * | |
1511 | * Returns pointer to decoded unicast packet if the packet was decoded or NULL | |
1512 | * in case of an error. | |
1513 | */ | |
1514 | static struct batadv_unicast_packet * | |
6e0895c2 | 1515 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1516 | struct batadv_nc_packet *nc_packet) |
1517 | { | |
1518 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1519 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1520 | struct batadv_unicast_packet *unicast_packet; | |
1521 | struct batadv_coded_packet coded_packet_tmp; | |
1522 | struct ethhdr *ethhdr, ethhdr_tmp; | |
1523 | uint8_t *orig_dest, ttl, ttvn; | |
1524 | unsigned int coding_len; | |
7da19971 | 1525 | int err; |
2df5278b MH |
1526 | |
1527 | /* Save headers temporarily */ | |
1528 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1529 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1530 | ||
1531 | if (skb_cow(skb, 0) < 0) | |
1532 | return NULL; | |
1533 | ||
1534 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1535 | return NULL; | |
1536 | ||
1537 | /* Data points to batman header, so set mac header 14 bytes before | |
1538 | * and network to data | |
1539 | */ | |
1540 | skb_set_mac_header(skb, -ETH_HLEN); | |
1541 | skb_reset_network_header(skb); | |
1542 | ||
1543 | /* Reconstruct original mac header */ | |
7ed4be95 | 1544 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1545 | memcpy(ethhdr, ðhdr_tmp, sizeof(*ethhdr)); |
1546 | ||
1547 | /* Select the correct unicast header information based on the location | |
1548 | * of our mac address in the coded_packet header | |
1549 | */ | |
6e0895c2 | 1550 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1551 | /* If we are the second destination the packet was overheard, |
1552 | * so the Ethernet address must be copied to h_dest and | |
1553 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1554 | */ | |
1555 | memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN); | |
1556 | skb->pkt_type = PACKET_HOST; | |
1557 | ||
1558 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1559 | ttl = coded_packet_tmp.second_ttl; | |
1560 | ttvn = coded_packet_tmp.second_ttvn; | |
1561 | } else { | |
1562 | orig_dest = coded_packet_tmp.first_orig_dest; | |
1563 | ttl = coded_packet_tmp.header.ttl; | |
1564 | ttvn = coded_packet_tmp.first_ttvn; | |
1565 | } | |
1566 | ||
1567 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1568 | ||
1569 | if (coding_len > skb->len) | |
1570 | return NULL; | |
1571 | ||
1572 | /* Here the magic is reversed: | |
1573 | * extract the missing packet from the received coded packet | |
1574 | */ | |
1575 | batadv_nc_memxor(skb->data + h_size, | |
1576 | nc_packet->skb->data + h_size, | |
1577 | coding_len); | |
1578 | ||
1579 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1580 | if (nc_packet->skb->len > coding_len + h_size) { |
1581 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1582 | if (err) | |
1583 | return NULL; | |
1584 | } | |
2df5278b MH |
1585 | |
1586 | /* Create decoded unicast packet */ | |
1587 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
1588 | unicast_packet->header.packet_type = BATADV_UNICAST; | |
1589 | unicast_packet->header.version = BATADV_COMPAT_VERSION; | |
1590 | unicast_packet->header.ttl = ttl; | |
1591 | memcpy(unicast_packet->dest, orig_dest, ETH_ALEN); | |
1592 | unicast_packet->ttvn = ttvn; | |
1593 | ||
1594 | batadv_nc_packet_free(nc_packet); | |
1595 | return unicast_packet; | |
1596 | } | |
1597 | ||
1598 | /** | |
1599 | * batadv_nc_find_decoding_packet - search through buffered decoding data to | |
1600 | * find the data needed to decode the coded packet | |
1601 | * @bat_priv: the bat priv with all the soft interface information | |
1602 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1603 | * @coded: coded packet we try to find decode data for | |
1604 | * | |
1605 | * Returns pointer to nc packet if the needed data was found or NULL otherwise. | |
1606 | */ | |
1607 | static struct batadv_nc_packet * | |
1608 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1609 | struct ethhdr *ethhdr, | |
1610 | struct batadv_coded_packet *coded) | |
1611 | { | |
1612 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1613 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1614 | struct batadv_nc_path *nc_path, nc_path_key; | |
1615 | uint8_t *dest, *source; | |
1616 | __be32 packet_id; | |
1617 | int index; | |
1618 | ||
1619 | if (!hash) | |
1620 | return NULL; | |
1621 | ||
1622 | /* Select the correct packet id based on the location of our mac-addr */ | |
1623 | dest = ethhdr->h_source; | |
6e0895c2 | 1624 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1625 | source = coded->second_source; |
1626 | packet_id = coded->second_crc; | |
1627 | } else { | |
1628 | source = coded->first_source; | |
1629 | packet_id = coded->first_crc; | |
1630 | } | |
1631 | ||
1632 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1633 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1634 | ||
1635 | /* Search for matching coding path */ | |
1636 | rcu_read_lock(); | |
1637 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1638 | /* Find matching nc_packet */ | |
1639 | spin_lock_bh(&nc_path->packet_list_lock); | |
1640 | list_for_each_entry(tmp_nc_packet, | |
1641 | &nc_path->packet_list, list) { | |
1642 | if (packet_id == tmp_nc_packet->packet_id) { | |
1643 | list_del(&tmp_nc_packet->list); | |
1644 | ||
1645 | nc_packet = tmp_nc_packet; | |
1646 | break; | |
1647 | } | |
1648 | } | |
1649 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1650 | ||
1651 | if (nc_packet) | |
1652 | break; | |
1653 | } | |
1654 | rcu_read_unlock(); | |
1655 | ||
1656 | if (!nc_packet) | |
1657 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1658 | "No decoding packet found for %u\n", packet_id); | |
1659 | ||
1660 | return nc_packet; | |
1661 | } | |
1662 | ||
1663 | /** | |
1664 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the | |
1665 | * resulting unicast packet | |
1666 | * @skb: incoming coded packet | |
1667 | * @recv_if: pointer to interface this packet was received on | |
1668 | */ | |
1669 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1670 | struct batadv_hard_iface *recv_if) | |
1671 | { | |
1672 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1673 | struct batadv_unicast_packet *unicast_packet; | |
1674 | struct batadv_coded_packet *coded_packet; | |
1675 | struct batadv_nc_packet *nc_packet; | |
1676 | struct ethhdr *ethhdr; | |
1677 | int hdr_size = sizeof(*coded_packet); | |
1678 | ||
1679 | /* Check if network coding is enabled */ | |
1680 | if (!atomic_read(&bat_priv->network_coding)) | |
1681 | return NET_RX_DROP; | |
1682 | ||
1683 | /* Make sure we can access (and remove) header */ | |
1684 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
1685 | return NET_RX_DROP; | |
1686 | ||
1687 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1688 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1689 | |
1690 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1691 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1692 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
2df5278b MH |
1693 | return NET_RX_DROP; |
1694 | ||
1695 | /* Update stat counter */ | |
6e0895c2 | 1696 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1697 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1698 | ||
1699 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1700 | coded_packet); | |
1701 | if (!nc_packet) { | |
1702 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1703 | return NET_RX_DROP; | |
1704 | } | |
1705 | ||
1706 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1707 | if (skb_linearize(skb) < 0) | |
1708 | goto free_nc_packet; | |
1709 | ||
1710 | if (skb_linearize(nc_packet->skb) < 0) | |
1711 | goto free_nc_packet; | |
1712 | ||
1713 | /* Decode the packet */ | |
6e0895c2 | 1714 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1715 | if (!unicast_packet) { |
1716 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1717 | goto free_nc_packet; | |
1718 | } | |
1719 | ||
1720 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1721 | BATADV_SKB_CB(skb)->decoded = true; | |
1722 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1723 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1724 | skb->len + ETH_HLEN); | |
1725 | return batadv_recv_unicast_packet(skb, recv_if); | |
1726 | ||
1727 | free_nc_packet: | |
1728 | batadv_nc_packet_free(nc_packet); | |
1729 | return NET_RX_DROP; | |
1730 | } | |
1731 | ||
d353d8d4 | 1732 | /** |
6c519bad | 1733 | * batadv_nc_mesh_free - clean up network coding memory |
d353d8d4 MH |
1734 | * @bat_priv: the bat priv with all the soft interface information |
1735 | */ | |
6c519bad | 1736 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
d353d8d4 MH |
1737 | { |
1738 | cancel_delayed_work_sync(&bat_priv->nc.work); | |
612d2b4f | 1739 | |
95332477 MH |
1740 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1741 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1742 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1743 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1744 | } |
d56b1705 MH |
1745 | |
1746 | /** | |
1747 | * batadv_nc_nodes_seq_print_text - print the nc node information | |
1748 | * @seq: seq file to print on | |
1749 | * @offset: not used | |
1750 | */ | |
1751 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) | |
1752 | { | |
1753 | struct net_device *net_dev = (struct net_device *)seq->private; | |
1754 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
1755 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
1756 | struct batadv_hard_iface *primary_if; | |
1757 | struct hlist_head *head; | |
1758 | struct batadv_orig_node *orig_node; | |
1759 | struct batadv_nc_node *nc_node; | |
1760 | int i; | |
1761 | ||
1762 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
1763 | if (!primary_if) | |
1764 | goto out; | |
1765 | ||
1766 | /* Traverse list of originators */ | |
1767 | for (i = 0; i < hash->size; i++) { | |
1768 | head = &hash->table[i]; | |
1769 | ||
1770 | /* For each orig_node in this bin */ | |
1771 | rcu_read_lock(); | |
1772 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { | |
aa27c312 ML |
1773 | /* no need to print the orig node if it does not have |
1774 | * network coding neighbors | |
1775 | */ | |
1776 | if (list_empty(&orig_node->in_coding_list) && | |
1777 | list_empty(&orig_node->out_coding_list)) | |
1778 | continue; | |
1779 | ||
d56b1705 MH |
1780 | seq_printf(seq, "Node: %pM\n", orig_node->orig); |
1781 | ||
0c814653 | 1782 | seq_puts(seq, " Ingoing: "); |
d56b1705 MH |
1783 | /* For each in_nc_node to this orig_node */ |
1784 | list_for_each_entry_rcu(nc_node, | |
1785 | &orig_node->in_coding_list, | |
1786 | list) | |
1787 | seq_printf(seq, "%pM ", | |
1788 | nc_node->addr); | |
0c814653 | 1789 | seq_puts(seq, "\n"); |
d56b1705 | 1790 | |
0c814653 | 1791 | seq_puts(seq, " Outgoing: "); |
d56b1705 MH |
1792 | /* For out_nc_node to this orig_node */ |
1793 | list_for_each_entry_rcu(nc_node, | |
1794 | &orig_node->out_coding_list, | |
1795 | list) | |
1796 | seq_printf(seq, "%pM ", | |
1797 | nc_node->addr); | |
0c814653 | 1798 | seq_puts(seq, "\n\n"); |
d56b1705 MH |
1799 | } |
1800 | rcu_read_unlock(); | |
1801 | } | |
1802 | ||
1803 | out: | |
1804 | if (primary_if) | |
1805 | batadv_hardif_free_ref(primary_if); | |
1806 | return 0; | |
1807 | } | |
1808 | ||
1809 | /** | |
1810 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs | |
1811 | * @bat_priv: the bat priv with all the soft interface information | |
1812 | */ | |
1813 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) | |
1814 | { | |
1815 | struct dentry *nc_dir, *file; | |
1816 | ||
1817 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); | |
1818 | if (!nc_dir) | |
1819 | goto out; | |
1820 | ||
1821 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, | |
1822 | &bat_priv->nc.min_tq); | |
1823 | if (!file) | |
1824 | goto out; | |
1825 | ||
95332477 MH |
1826 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1827 | &bat_priv->nc.max_fwd_delay); | |
1828 | if (!file) | |
1829 | goto out; | |
1830 | ||
612d2b4f MH |
1831 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1832 | &bat_priv->nc.max_buffer_time); | |
1833 | if (!file) | |
1834 | goto out; | |
1835 | ||
d56b1705 MH |
1836 | return 0; |
1837 | ||
1838 | out: | |
1839 | return -ENOMEM; | |
1840 | } |