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0046b040 | 1 | /* Copyright (C) 2012-2016 B.A.T.M.A.N. contributors: |
d353d8d4 MH |
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 | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
d353d8d4 MH |
16 | */ |
17 | ||
1e2c2a4f SE |
18 | #include "network-coding.h" |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/atomic.h> | |
4635469f | 22 | #include <linux/bitops.h> |
1e2c2a4f SE |
23 | #include <linux/byteorder/generic.h> |
24 | #include <linux/compiler.h> | |
d56b1705 | 25 | #include <linux/debugfs.h> |
1e2c2a4f SE |
26 | #include <linux/errno.h> |
27 | #include <linux/etherdevice.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/if_ether.h> | |
30 | #include <linux/if_packet.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/jhash.h> | |
33 | #include <linux/jiffies.h> | |
34 | #include <linux/kernel.h> | |
35 | #include <linux/list.h> | |
36 | #include <linux/lockdep.h> | |
37 | #include <linux/netdevice.h> | |
38 | #include <linux/printk.h> | |
39 | #include <linux/random.h> | |
40 | #include <linux/rculist.h> | |
41 | #include <linux/rcupdate.h> | |
42 | #include <linux/seq_file.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/slab.h> | |
45 | #include <linux/spinlock.h> | |
46 | #include <linux/stat.h> | |
47 | #include <linux/stddef.h> | |
48 | #include <linux/string.h> | |
49 | #include <linux/workqueue.h> | |
d56b1705 | 50 | |
1e2c2a4f | 51 | #include "hard-interface.h" |
95332477 | 52 | #include "hash.h" |
d56b1705 | 53 | #include "originator.h" |
1e2c2a4f | 54 | #include "packet.h" |
2df5278b | 55 | #include "routing.h" |
1e2c2a4f | 56 | #include "send.h" |
d353d8d4 | 57 | |
95332477 | 58 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
612d2b4f | 59 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
95332477 | 60 | |
d353d8d4 | 61 | static void batadv_nc_worker(struct work_struct *work); |
2df5278b MH |
62 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
63 | struct batadv_hard_iface *recv_if); | |
d353d8d4 | 64 | |
6c519bad MS |
65 | /** |
66 | * batadv_nc_init - one-time initialization for network coding | |
672e7978 SE |
67 | * |
68 | * Return: 0 on success or negative error number in case of failure | |
6c519bad MS |
69 | */ |
70 | int __init batadv_nc_init(void) | |
71 | { | |
72 | int ret; | |
73 | ||
74 | /* Register our packet type */ | |
75 | ret = batadv_recv_handler_register(BATADV_CODED, | |
76 | batadv_nc_recv_coded_packet); | |
77 | ||
78 | return ret; | |
79 | } | |
80 | ||
d353d8d4 MH |
81 | /** |
82 | * batadv_nc_start_timer - initialise the nc periodic worker | |
83 | * @bat_priv: the bat priv with all the soft interface information | |
84 | */ | |
85 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
86 | { | |
87 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
88 | msecs_to_jiffies(10)); | |
89 | } | |
90 | ||
3f4841ff ML |
91 | /** |
92 | * batadv_nc_tvlv_container_update - update the network coding tvlv container | |
93 | * after network coding setting change | |
94 | * @bat_priv: the bat priv with all the soft interface information | |
95 | */ | |
96 | static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv) | |
97 | { | |
98 | char nc_mode; | |
99 | ||
100 | nc_mode = atomic_read(&bat_priv->network_coding); | |
101 | ||
102 | switch (nc_mode) { | |
103 | case 0: | |
104 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
105 | break; | |
106 | case 1: | |
107 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1, | |
108 | NULL, 0); | |
109 | break; | |
110 | } | |
111 | } | |
112 | ||
113 | /** | |
114 | * batadv_nc_status_update - update the network coding tvlv container after | |
115 | * network coding setting change | |
116 | * @net_dev: the soft interface net device | |
117 | */ | |
118 | void batadv_nc_status_update(struct net_device *net_dev) | |
119 | { | |
120 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 121 | |
3f4841ff ML |
122 | batadv_nc_tvlv_container_update(bat_priv); |
123 | } | |
124 | ||
125 | /** | |
126 | * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container | |
127 | * @bat_priv: the bat priv with all the soft interface information | |
128 | * @orig: the orig_node of the ogm | |
129 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
130 | * @tvlv_value: tvlv buffer containing the gateway data | |
131 | * @tvlv_value_len: tvlv buffer length | |
132 | */ | |
133 | static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
134 | struct batadv_orig_node *orig, | |
6b5e971a SE |
135 | u8 flags, |
136 | void *tvlv_value, u16 tvlv_value_len) | |
3f4841ff ML |
137 | { |
138 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
4635469f | 139 | clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); |
3f4841ff | 140 | else |
4635469f | 141 | set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); |
3f4841ff ML |
142 | } |
143 | ||
d353d8d4 | 144 | /** |
6c519bad | 145 | * batadv_nc_mesh_init - initialise coding hash table and start house keeping |
d353d8d4 | 146 | * @bat_priv: the bat priv with all the soft interface information |
672e7978 SE |
147 | * |
148 | * Return: 0 on success or negative error number in case of failure | |
d353d8d4 | 149 | */ |
6c519bad | 150 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
d353d8d4 | 151 | { |
95332477 | 152 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 153 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 154 | |
612d2b4f | 155 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
156 | return 0; |
157 | ||
158 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
159 | if (!bat_priv->nc.coding_hash) | |
160 | goto err; | |
161 | ||
162 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
163 | &batadv_nc_coding_hash_lock_class_key); | |
164 | ||
612d2b4f MH |
165 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
166 | if (!bat_priv->nc.decoding_hash) | |
167 | goto err; | |
168 | ||
f44d5407 | 169 | batadv_hash_set_lock_class(bat_priv->nc.decoding_hash, |
612d2b4f MH |
170 | &batadv_nc_decoding_hash_lock_class_key); |
171 | ||
d353d8d4 MH |
172 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
173 | batadv_nc_start_timer(bat_priv); | |
174 | ||
3f4841ff ML |
175 | batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1, |
176 | NULL, BATADV_TVLV_NC, 1, | |
177 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
178 | batadv_nc_tvlv_container_update(bat_priv); | |
d353d8d4 | 179 | return 0; |
95332477 MH |
180 | |
181 | err: | |
182 | return -ENOMEM; | |
d353d8d4 MH |
183 | } |
184 | ||
185 | /** | |
186 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables | |
187 | * @bat_priv: the bat priv with all the soft interface information | |
188 | */ | |
189 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
190 | { | |
dab7b621 | 191 | atomic_set(&bat_priv->network_coding, 0); |
d56b1705 | 192 | bat_priv->nc.min_tq = 200; |
95332477 | 193 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 194 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
195 | } |
196 | ||
197 | /** | |
198 | * batadv_nc_init_orig - initialise the nc fields of an orig_node | |
199 | * @orig_node: the orig_node which is going to be initialised | |
200 | */ | |
201 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
202 | { | |
203 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
204 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
205 | spin_lock_init(&orig_node->in_coding_list_lock); | |
206 | spin_lock_init(&orig_node->out_coding_list_lock); | |
207 | } | |
208 | ||
209 | /** | |
44e8e7e9 SE |
210 | * batadv_nc_node_release - release nc_node from lists and queue for free after |
211 | * rcu grace period | |
212 | * @nc_node: the nc node to free | |
d56b1705 | 213 | */ |
44e8e7e9 | 214 | static void batadv_nc_node_release(struct batadv_nc_node *nc_node) |
d56b1705 | 215 | { |
d56b1705 | 216 | batadv_orig_node_free_ref(nc_node->orig_node); |
44e8e7e9 | 217 | kfree_rcu(nc_node, rcu); |
d56b1705 MH |
218 | } |
219 | ||
220 | /** | |
44e8e7e9 SE |
221 | * batadv_nc_node_free_ref - decrement the nc node refcounter and possibly |
222 | * release it | |
d56b1705 MH |
223 | * @nc_node: the nc node to free |
224 | */ | |
225 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) | |
226 | { | |
227 | if (atomic_dec_and_test(&nc_node->refcount)) | |
44e8e7e9 | 228 | batadv_nc_node_release(nc_node); |
d56b1705 MH |
229 | } |
230 | ||
95332477 MH |
231 | /** |
232 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly | |
233 | * frees it | |
234 | * @nc_path: the nc node to free | |
235 | */ | |
236 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) | |
237 | { | |
238 | if (atomic_dec_and_test(&nc_path->refcount)) | |
239 | kfree_rcu(nc_path, rcu); | |
240 | } | |
241 | ||
242 | /** | |
243 | * batadv_nc_packet_free - frees nc packet | |
244 | * @nc_packet: the nc packet to free | |
245 | */ | |
246 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) | |
247 | { | |
c799443e | 248 | kfree_skb(nc_packet->skb); |
95332477 MH |
249 | batadv_nc_path_free_ref(nc_packet->nc_path); |
250 | kfree(nc_packet); | |
251 | } | |
252 | ||
d56b1705 MH |
253 | /** |
254 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged | |
255 | * @bat_priv: the bat priv with all the soft interface information | |
256 | * @nc_node: the nc node to check | |
257 | * | |
62fe710f | 258 | * Return: true if the entry has to be purged now, false otherwise |
d56b1705 MH |
259 | */ |
260 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
261 | struct batadv_nc_node *nc_node) | |
262 | { | |
263 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
264 | return true; | |
265 | ||
266 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
267 | } | |
268 | ||
95332477 MH |
269 | /** |
270 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out | |
271 | * @bat_priv: the bat priv with all the soft interface information | |
272 | * @nc_path: the nc path to check | |
273 | * | |
62fe710f | 274 | * Return: true if the entry has to be purged now, false otherwise |
95332477 MH |
275 | */ |
276 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
277 | struct batadv_nc_path *nc_path) | |
278 | { | |
279 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
280 | return true; | |
281 | ||
282 | /* purge the path when no packets has been added for 10 times the | |
283 | * max_fwd_delay time | |
284 | */ | |
285 | return batadv_has_timed_out(nc_path->last_valid, | |
286 | bat_priv->nc.max_fwd_delay * 10); | |
287 | } | |
288 | ||
612d2b4f MH |
289 | /** |
290 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out | |
291 | * @bat_priv: the bat priv with all the soft interface information | |
292 | * @nc_path: the nc path to check | |
293 | * | |
62fe710f | 294 | * Return: true if the entry has to be purged now, false otherwise |
612d2b4f MH |
295 | */ |
296 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
297 | struct batadv_nc_path *nc_path) | |
298 | { | |
299 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
300 | return true; | |
301 | ||
302 | /* purge the path when no packets has been added for 10 times the | |
303 | * max_buffer time | |
304 | */ | |
305 | return batadv_has_timed_out(nc_path->last_valid, | |
fc1f8693 | 306 | bat_priv->nc.max_buffer_time * 10); |
612d2b4f MH |
307 | } |
308 | ||
d56b1705 MH |
309 | /** |
310 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale | |
311 | * entries | |
312 | * @bat_priv: the bat priv with all the soft interface information | |
313 | * @list: list of nc nodes | |
314 | * @lock: nc node list lock | |
315 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
316 | * not. This function takes the nc node as argument and has to return | |
317 | * a boolean value: true if the entry has to be deleted, false | |
318 | * otherwise | |
319 | */ | |
320 | static void | |
321 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
322 | struct list_head *list, | |
323 | spinlock_t *lock, | |
324 | bool (*to_purge)(struct batadv_priv *, | |
325 | struct batadv_nc_node *)) | |
326 | { | |
327 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
328 | ||
329 | /* For each nc_node in list */ | |
330 | spin_lock_bh(lock); | |
331 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
332 | /* if an helper function has been passed as parameter, | |
333 | * ask it if the entry has to be purged or not | |
334 | */ | |
335 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
336 | continue; | |
337 | ||
338 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
339 | "Removing nc_node %pM -> %pM\n", | |
340 | nc_node->addr, nc_node->orig_node->orig); | |
341 | list_del_rcu(&nc_node->list); | |
342 | batadv_nc_node_free_ref(nc_node); | |
343 | } | |
344 | spin_unlock_bh(lock); | |
345 | } | |
346 | ||
347 | /** | |
348 | * batadv_nc_purge_orig - purges all nc node data attached of the given | |
349 | * originator | |
350 | * @bat_priv: the bat priv with all the soft interface information | |
351 | * @orig_node: orig_node with the nc node entries to be purged | |
352 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
353 | * not. This function takes the nc node as argument and has to return | |
354 | * a boolean value: true is the entry has to be deleted, false | |
355 | * otherwise | |
356 | */ | |
357 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
358 | struct batadv_orig_node *orig_node, | |
359 | bool (*to_purge)(struct batadv_priv *, | |
360 | struct batadv_nc_node *)) | |
361 | { | |
362 | /* Check ingoing nc_node's of this orig_node */ | |
363 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
364 | &orig_node->in_coding_list_lock, | |
365 | to_purge); | |
366 | ||
367 | /* Check outgoing nc_node's of this orig_node */ | |
368 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
369 | &orig_node->out_coding_list_lock, | |
370 | to_purge); | |
371 | } | |
372 | ||
373 | /** | |
374 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they | |
375 | * have timed out nc nodes | |
376 | * @bat_priv: the bat priv with all the soft interface information | |
377 | */ | |
378 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
379 | { | |
380 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
381 | struct hlist_head *head; | |
382 | struct batadv_orig_node *orig_node; | |
6b5e971a | 383 | u32 i; |
d56b1705 MH |
384 | |
385 | if (!hash) | |
386 | return; | |
387 | ||
388 | /* For each orig_node */ | |
389 | for (i = 0; i < hash->size; i++) { | |
390 | head = &hash->table[i]; | |
391 | ||
392 | rcu_read_lock(); | |
393 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
394 | batadv_nc_purge_orig(bat_priv, orig_node, | |
395 | batadv_nc_to_purge_nc_node); | |
396 | rcu_read_unlock(); | |
397 | } | |
d353d8d4 MH |
398 | } |
399 | ||
95332477 MH |
400 | /** |
401 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove | |
402 | * unused ones | |
403 | * @bat_priv: the bat priv with all the soft interface information | |
404 | * @hash: hash table containing the nc paths to check | |
405 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
406 | * not. This function takes the nc node as argument and has to return | |
407 | * a boolean value: true is the entry has to be deleted, false | |
408 | * otherwise | |
409 | */ | |
410 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
411 | struct batadv_hashtable *hash, | |
412 | bool (*to_purge)(struct batadv_priv *, | |
413 | struct batadv_nc_path *)) | |
414 | { | |
415 | struct hlist_head *head; | |
416 | struct hlist_node *node_tmp; | |
417 | struct batadv_nc_path *nc_path; | |
418 | spinlock_t *lock; /* Protects lists in hash */ | |
6b5e971a | 419 | u32 i; |
95332477 MH |
420 | |
421 | for (i = 0; i < hash->size; i++) { | |
422 | head = &hash->table[i]; | |
423 | lock = &hash->list_locks[i]; | |
424 | ||
425 | /* For each nc_path in this bin */ | |
426 | spin_lock_bh(lock); | |
427 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
428 | /* if an helper function has been passed as parameter, | |
429 | * ask it if the entry has to be purged or not | |
430 | */ | |
431 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
432 | continue; | |
433 | ||
434 | /* purging an non-empty nc_path should never happen, but | |
435 | * is observed under high CPU load. Delay the purging | |
436 | * until next iteration to allow the packet_list to be | |
437 | * emptied first. | |
438 | */ | |
439 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
440 | net_ratelimited_function(printk, | |
441 | KERN_WARNING | |
442 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
443 | nc_path->prev_hop, | |
444 | nc_path->next_hop); | |
445 | continue; | |
446 | } | |
447 | ||
448 | /* nc_path is unused, so remove it */ | |
449 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
450 | "Remove nc_path %pM -> %pM\n", | |
451 | nc_path->prev_hop, nc_path->next_hop); | |
452 | hlist_del_rcu(&nc_path->hash_entry); | |
453 | batadv_nc_path_free_ref(nc_path); | |
454 | } | |
455 | spin_unlock_bh(lock); | |
456 | } | |
457 | } | |
458 | ||
459 | /** | |
460 | * batadv_nc_hash_key_gen - computes the nc_path hash key | |
461 | * @key: buffer to hold the final hash key | |
462 | * @src: source ethernet mac address going into the hash key | |
463 | * @dst: destination ethernet mac address going into the hash key | |
464 | */ | |
465 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
466 | const char *dst) | |
467 | { | |
468 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
469 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
470 | } | |
471 | ||
472 | /** | |
473 | * batadv_nc_hash_choose - compute the hash value for an nc path | |
474 | * @data: data to hash | |
475 | * @size: size of the hash table | |
476 | * | |
62fe710f | 477 | * Return: the selected index in the hash table for the given data. |
95332477 | 478 | */ |
6b5e971a | 479 | static u32 batadv_nc_hash_choose(const void *data, u32 size) |
95332477 MH |
480 | { |
481 | const struct batadv_nc_path *nc_path = data; | |
6b5e971a | 482 | u32 hash = 0; |
95332477 | 483 | |
36fd61cb SE |
484 | hash = jhash(&nc_path->prev_hop, sizeof(nc_path->prev_hop), hash); |
485 | hash = jhash(&nc_path->next_hop, sizeof(nc_path->next_hop), hash); | |
95332477 MH |
486 | |
487 | return hash % size; | |
488 | } | |
489 | ||
490 | /** | |
491 | * batadv_nc_hash_compare - comparing function used in the network coding hash | |
492 | * tables | |
493 | * @node: node in the local table | |
494 | * @data2: second object to compare the node to | |
495 | * | |
62fe710f | 496 | * Return: 1 if the two entry are the same, 0 otherwise |
95332477 MH |
497 | */ |
498 | static int batadv_nc_hash_compare(const struct hlist_node *node, | |
499 | const void *data2) | |
500 | { | |
501 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
502 | ||
503 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
504 | nc_path2 = data2; | |
505 | ||
506 | /* Return 1 if the two keys are identical */ | |
507 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, | |
508 | sizeof(nc_path1->prev_hop)) != 0) | |
509 | return 0; | |
510 | ||
511 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, | |
512 | sizeof(nc_path1->next_hop)) != 0) | |
513 | return 0; | |
514 | ||
515 | return 1; | |
516 | } | |
517 | ||
518 | /** | |
519 | * batadv_nc_hash_find - search for an existing nc path and return it | |
520 | * @hash: hash table containing the nc path | |
521 | * @data: search key | |
522 | * | |
62fe710f | 523 | * Return: the nc_path if found, NULL otherwise. |
95332477 MH |
524 | */ |
525 | static struct batadv_nc_path * | |
526 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
527 | void *data) | |
528 | { | |
529 | struct hlist_head *head; | |
530 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
531 | int index; | |
532 | ||
533 | if (!hash) | |
534 | return NULL; | |
535 | ||
536 | index = batadv_nc_hash_choose(data, hash->size); | |
537 | head = &hash->table[index]; | |
538 | ||
539 | rcu_read_lock(); | |
540 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
541 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
542 | continue; | |
543 | ||
544 | if (!atomic_inc_not_zero(&nc_path->refcount)) | |
545 | continue; | |
546 | ||
547 | nc_path_tmp = nc_path; | |
548 | break; | |
549 | } | |
550 | rcu_read_unlock(); | |
551 | ||
552 | return nc_path_tmp; | |
553 | } | |
554 | ||
555 | /** | |
556 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct | |
557 | * @nc_packet: the nc packet to send | |
558 | */ | |
559 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
560 | { | |
561 | batadv_send_skb_packet(nc_packet->skb, | |
562 | nc_packet->neigh_node->if_incoming, | |
563 | nc_packet->nc_path->next_hop); | |
564 | nc_packet->skb = NULL; | |
565 | batadv_nc_packet_free(nc_packet); | |
566 | } | |
567 | ||
612d2b4f MH |
568 | /** |
569 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. | |
570 | * @bat_priv: the bat priv with all the soft interface information | |
571 | * @nc_path: the nc path the packet belongs to | |
572 | * @nc_packet: the nc packet to be checked | |
573 | * | |
574 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
575 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
576 | * queue. Has to be called with the appropriate locks. | |
577 | * | |
62fe710f | 578 | * Return: false as soon as the entry in the fifo queue has not been timed out |
612d2b4f MH |
579 | * yet and true otherwise. |
580 | */ | |
581 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
582 | struct batadv_nc_path *nc_path, | |
583 | struct batadv_nc_packet *nc_packet) | |
584 | { | |
585 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
586 | bool res = false; | |
587 | ||
2c72d655 SE |
588 | lockdep_assert_held(&nc_path->packet_list_lock); |
589 | ||
612d2b4f MH |
590 | /* Packets are added to tail, so the remaining packets did not time |
591 | * out and we can stop processing the current queue | |
592 | */ | |
593 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
594 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
595 | goto out; | |
596 | ||
597 | /* purge nc packet */ | |
598 | list_del(&nc_packet->list); | |
599 | batadv_nc_packet_free(nc_packet); | |
600 | ||
601 | res = true; | |
602 | ||
603 | out: | |
604 | return res; | |
605 | } | |
606 | ||
95332477 MH |
607 | /** |
608 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. | |
609 | * @bat_priv: the bat priv with all the soft interface information | |
610 | * @nc_path: the nc path the packet belongs to | |
611 | * @nc_packet: the nc packet to be checked | |
612 | * | |
613 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
614 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
615 | * queue. Has to be called with the appropriate locks. | |
616 | * | |
62fe710f | 617 | * Return: false as soon as the entry in the fifo queue has not been timed out |
95332477 MH |
618 | * yet and true otherwise. |
619 | */ | |
620 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
621 | struct batadv_nc_path *nc_path, | |
622 | struct batadv_nc_packet *nc_packet) | |
623 | { | |
624 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
625 | ||
2c72d655 SE |
626 | lockdep_assert_held(&nc_path->packet_list_lock); |
627 | ||
95332477 MH |
628 | /* Packets are added to tail, so the remaining packets did not time |
629 | * out and we can stop processing the current queue | |
630 | */ | |
631 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
632 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
633 | return false; | |
634 | ||
635 | /* Send packet */ | |
636 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
637 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
638 | nc_packet->skb->len + ETH_HLEN); | |
639 | list_del(&nc_packet->list); | |
640 | batadv_nc_send_packet(nc_packet); | |
641 | ||
642 | return true; | |
643 | } | |
644 | ||
645 | /** | |
646 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out | |
647 | * nc packets | |
648 | * @bat_priv: the bat priv with all the soft interface information | |
649 | * @hash: to be processed hash table | |
650 | * @process_fn: Function called to process given nc packet. Should return true | |
651 | * to encourage this function to proceed with the next packet. | |
652 | * Otherwise the rest of the current queue is skipped. | |
653 | */ | |
654 | static void | |
655 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
656 | struct batadv_hashtable *hash, | |
657 | bool (*process_fn)(struct batadv_priv *, | |
658 | struct batadv_nc_path *, | |
659 | struct batadv_nc_packet *)) | |
660 | { | |
661 | struct hlist_head *head; | |
662 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
663 | struct batadv_nc_path *nc_path; | |
664 | bool ret; | |
665 | int i; | |
666 | ||
667 | if (!hash) | |
668 | return; | |
669 | ||
670 | /* Loop hash table bins */ | |
671 | for (i = 0; i < hash->size; i++) { | |
672 | head = &hash->table[i]; | |
673 | ||
674 | /* Loop coding paths */ | |
675 | rcu_read_lock(); | |
676 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
677 | /* Loop packets */ | |
678 | spin_lock_bh(&nc_path->packet_list_lock); | |
679 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
680 | &nc_path->packet_list, list) { | |
681 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
682 | if (!ret) | |
683 | break; | |
684 | } | |
685 | spin_unlock_bh(&nc_path->packet_list_lock); | |
686 | } | |
687 | rcu_read_unlock(); | |
688 | } | |
689 | } | |
690 | ||
d353d8d4 MH |
691 | /** |
692 | * batadv_nc_worker - periodic task for house keeping related to network coding | |
693 | * @work: kernel work struct | |
694 | */ | |
695 | static void batadv_nc_worker(struct work_struct *work) | |
696 | { | |
697 | struct delayed_work *delayed_work; | |
698 | struct batadv_priv_nc *priv_nc; | |
699 | struct batadv_priv *bat_priv; | |
95332477 | 700 | unsigned long timeout; |
d353d8d4 MH |
701 | |
702 | delayed_work = container_of(work, struct delayed_work, work); | |
703 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); | |
704 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
705 | ||
d56b1705 | 706 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
707 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
708 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
709 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
710 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
711 | |
712 | timeout = bat_priv->nc.max_fwd_delay; | |
713 | ||
714 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
715 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
716 | batadv_nc_fwd_flush); | |
717 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
718 | } | |
d56b1705 | 719 | |
612d2b4f MH |
720 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
721 | bat_priv->nc.max_buffer_time)) { | |
722 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
723 | batadv_nc_sniffed_purge); | |
724 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
725 | } | |
726 | ||
d353d8d4 MH |
727 | /* Schedule a new check */ |
728 | batadv_nc_start_timer(bat_priv); | |
729 | } | |
730 | ||
d56b1705 MH |
731 | /** |
732 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for | |
733 | * coding or not | |
734 | * @bat_priv: the bat priv with all the soft interface information | |
735 | * @orig_node: neighboring orig node which may be used as nc candidate | |
736 | * @ogm_packet: incoming ogm packet also used for the checks | |
737 | * | |
62fe710f | 738 | * Return: true if: |
d56b1705 MH |
739 | * 1) The OGM must have the most recent sequence number. |
740 | * 2) The TTL must be decremented by one and only one. | |
741 | * 3) The OGM must be received from the first hop from orig_node. | |
742 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
743 | */ | |
744 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
745 | struct batadv_orig_node *orig_node, | |
746 | struct batadv_ogm_packet *ogm_packet) | |
747 | { | |
7351a482 | 748 | struct batadv_orig_ifinfo *orig_ifinfo; |
6b5e971a SE |
749 | u32 last_real_seqno; |
750 | u8 last_ttl; | |
7351a482 SW |
751 | |
752 | orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT); | |
753 | if (!orig_ifinfo) | |
d56b1705 | 754 | return false; |
7351a482 SW |
755 | |
756 | last_ttl = orig_ifinfo->last_ttl; | |
757 | last_real_seqno = orig_ifinfo->last_real_seqno; | |
758 | batadv_orig_ifinfo_free_ref(orig_ifinfo); | |
759 | ||
760 | if (last_real_seqno != ntohl(ogm_packet->seqno)) | |
761 | return false; | |
762 | if (last_ttl != ogm_packet->ttl + 1) | |
d56b1705 MH |
763 | return false; |
764 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
765 | return false; | |
766 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
767 | return false; | |
768 | ||
769 | return true; | |
770 | } | |
771 | ||
772 | /** | |
773 | * batadv_nc_find_nc_node - search for an existing nc node and return it | |
774 | * @orig_node: orig node originating the ogm packet | |
775 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
776 | * (can be equal to orig_node) | |
777 | * @in_coding: traverse incoming or outgoing network coding list | |
778 | * | |
62fe710f | 779 | * Return: the nc_node if found, NULL otherwise. |
d56b1705 MH |
780 | */ |
781 | static struct batadv_nc_node | |
782 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
783 | struct batadv_orig_node *orig_neigh_node, | |
784 | bool in_coding) | |
785 | { | |
786 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
787 | struct list_head *list; | |
788 | ||
789 | if (in_coding) | |
790 | list = &orig_neigh_node->in_coding_list; | |
791 | else | |
792 | list = &orig_neigh_node->out_coding_list; | |
793 | ||
794 | /* Traverse list of nc_nodes to orig_node */ | |
795 | rcu_read_lock(); | |
796 | list_for_each_entry_rcu(nc_node, list, list) { | |
797 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
798 | continue; | |
799 | ||
800 | if (!atomic_inc_not_zero(&nc_node->refcount)) | |
801 | continue; | |
802 | ||
803 | /* Found a match */ | |
804 | nc_node_out = nc_node; | |
805 | break; | |
806 | } | |
807 | rcu_read_unlock(); | |
808 | ||
809 | return nc_node_out; | |
810 | } | |
811 | ||
812 | /** | |
813 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was | |
814 | * not found | |
815 | * @bat_priv: the bat priv with all the soft interface information | |
816 | * @orig_node: orig node originating the ogm packet | |
817 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
818 | * (can be equal to orig_node) | |
819 | * @in_coding: traverse incoming or outgoing network coding list | |
820 | * | |
62fe710f | 821 | * Return: the nc_node if found or created, NULL in case of an error. |
d56b1705 MH |
822 | */ |
823 | static struct batadv_nc_node | |
824 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
825 | struct batadv_orig_node *orig_node, | |
826 | struct batadv_orig_node *orig_neigh_node, | |
827 | bool in_coding) | |
828 | { | |
829 | struct batadv_nc_node *nc_node; | |
830 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
831 | struct list_head *list; | |
832 | ||
833 | /* Check if nc_node is already added */ | |
834 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
835 | ||
836 | /* Node found */ | |
837 | if (nc_node) | |
838 | return nc_node; | |
839 | ||
840 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
841 | if (!nc_node) | |
842 | return NULL; | |
843 | ||
844 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) | |
845 | goto free; | |
846 | ||
847 | /* Initialize nc_node */ | |
848 | INIT_LIST_HEAD(&nc_node->list); | |
8fdd0153 | 849 | ether_addr_copy(nc_node->addr, orig_node->orig); |
d56b1705 MH |
850 | nc_node->orig_node = orig_neigh_node; |
851 | atomic_set(&nc_node->refcount, 2); | |
852 | ||
853 | /* Select ingoing or outgoing coding node */ | |
854 | if (in_coding) { | |
855 | lock = &orig_neigh_node->in_coding_list_lock; | |
856 | list = &orig_neigh_node->in_coding_list; | |
857 | } else { | |
858 | lock = &orig_neigh_node->out_coding_list_lock; | |
859 | list = &orig_neigh_node->out_coding_list; | |
860 | } | |
861 | ||
862 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", | |
863 | nc_node->addr, nc_node->orig_node->orig); | |
864 | ||
865 | /* Add nc_node to orig_node */ | |
866 | spin_lock_bh(lock); | |
867 | list_add_tail_rcu(&nc_node->list, list); | |
868 | spin_unlock_bh(lock); | |
869 | ||
870 | return nc_node; | |
871 | ||
872 | free: | |
873 | kfree(nc_node); | |
874 | return NULL; | |
875 | } | |
876 | ||
877 | /** | |
34473822 SE |
878 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node |
879 | * structs (best called on incoming OGMs) | |
d56b1705 MH |
880 | * @bat_priv: the bat priv with all the soft interface information |
881 | * @orig_node: orig node originating the ogm packet | |
882 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
883 | * (can be equal to orig_node) | |
884 | * @ogm_packet: incoming ogm packet | |
885 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
886 | */ | |
887 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
888 | struct batadv_orig_node *orig_node, | |
889 | struct batadv_orig_node *orig_neigh_node, | |
890 | struct batadv_ogm_packet *ogm_packet, | |
891 | int is_single_hop_neigh) | |
892 | { | |
4f248cff SE |
893 | struct batadv_nc_node *in_nc_node = NULL; |
894 | struct batadv_nc_node *out_nc_node = NULL; | |
d56b1705 MH |
895 | |
896 | /* Check if network coding is enabled */ | |
897 | if (!atomic_read(&bat_priv->network_coding)) | |
898 | goto out; | |
899 | ||
3f4841ff | 900 | /* check if orig node is network coding enabled */ |
4635469f | 901 | if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities)) |
3f4841ff ML |
902 | goto out; |
903 | ||
d56b1705 MH |
904 | /* accept ogms from 'good' neighbors and single hop neighbors */ |
905 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
906 | !is_single_hop_neigh) | |
907 | goto out; | |
908 | ||
909 | /* Add orig_node as in_nc_node on hop */ | |
910 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
911 | orig_neigh_node, true); | |
912 | if (!in_nc_node) | |
913 | goto out; | |
914 | ||
915 | in_nc_node->last_seen = jiffies; | |
916 | ||
917 | /* Add hop as out_nc_node on orig_node */ | |
918 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
919 | orig_node, false); | |
920 | if (!out_nc_node) | |
921 | goto out; | |
922 | ||
923 | out_nc_node->last_seen = jiffies; | |
924 | ||
925 | out: | |
926 | if (in_nc_node) | |
927 | batadv_nc_node_free_ref(in_nc_node); | |
928 | if (out_nc_node) | |
929 | batadv_nc_node_free_ref(out_nc_node); | |
930 | } | |
931 | ||
95332477 MH |
932 | /** |
933 | * batadv_nc_get_path - get existing nc_path or allocate a new one | |
934 | * @bat_priv: the bat priv with all the soft interface information | |
935 | * @hash: hash table containing the nc path | |
936 | * @src: ethernet source address - first half of the nc path search key | |
937 | * @dst: ethernet destination address - second half of the nc path search key | |
938 | * | |
62fe710f | 939 | * Return: pointer to nc_path if the path was found or created, returns NULL |
95332477 MH |
940 | * on error. |
941 | */ | |
942 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
943 | struct batadv_hashtable *hash, | |
6b5e971a SE |
944 | u8 *src, |
945 | u8 *dst) | |
95332477 MH |
946 | { |
947 | int hash_added; | |
948 | struct batadv_nc_path *nc_path, nc_path_key; | |
949 | ||
950 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
951 | ||
952 | /* Search for existing nc_path */ | |
953 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
954 | ||
955 | if (nc_path) { | |
956 | /* Set timestamp to delay removal of nc_path */ | |
957 | nc_path->last_valid = jiffies; | |
958 | return nc_path; | |
959 | } | |
960 | ||
961 | /* No existing nc_path was found; create a new */ | |
962 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
963 | ||
964 | if (!nc_path) | |
965 | return NULL; | |
966 | ||
967 | /* Initialize nc_path */ | |
968 | INIT_LIST_HEAD(&nc_path->packet_list); | |
969 | spin_lock_init(&nc_path->packet_list_lock); | |
970 | atomic_set(&nc_path->refcount, 2); | |
971 | nc_path->last_valid = jiffies; | |
8fdd0153 AQ |
972 | ether_addr_copy(nc_path->next_hop, dst); |
973 | ether_addr_copy(nc_path->prev_hop, src); | |
95332477 MH |
974 | |
975 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
976 | nc_path->prev_hop, | |
977 | nc_path->next_hop); | |
978 | ||
979 | /* Add nc_path to hash table */ | |
980 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, | |
981 | batadv_nc_hash_choose, &nc_path_key, | |
982 | &nc_path->hash_entry); | |
983 | ||
984 | if (hash_added < 0) { | |
985 | kfree(nc_path); | |
986 | return NULL; | |
987 | } | |
988 | ||
989 | return nc_path; | |
990 | } | |
991 | ||
3c12de9a MH |
992 | /** |
993 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair | |
994 | * selection of a receiver with slightly lower TQ than the other | |
995 | * @tq: to be weighted tq value | |
672e7978 SE |
996 | * |
997 | * Return: scaled tq value | |
3c12de9a | 998 | */ |
6b5e971a | 999 | static u8 batadv_nc_random_weight_tq(u8 tq) |
3c12de9a | 1000 | { |
6b5e971a | 1001 | u8 rand_val, rand_tq; |
3c12de9a MH |
1002 | |
1003 | get_random_bytes(&rand_val, sizeof(rand_val)); | |
1004 | ||
1005 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ | |
1006 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); | |
1007 | ||
1008 | /* normalize the randomized packet loss */ | |
1009 | rand_tq /= BATADV_TQ_MAX_VALUE; | |
1010 | ||
1011 | /* convert to (randomized) estimated tq again */ | |
1012 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
1013 | } | |
1014 | ||
1015 | /** | |
1016 | * batadv_nc_memxor - XOR destination with source | |
1017 | * @dst: byte array to XOR into | |
1018 | * @src: byte array to XOR from | |
1019 | * @len: length of destination array | |
1020 | */ | |
1021 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
1022 | { | |
1023 | unsigned int i; | |
1024 | ||
1025 | for (i = 0; i < len; ++i) | |
1026 | dst[i] ^= src[i]; | |
1027 | } | |
1028 | ||
1029 | /** | |
1030 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet | |
1031 | * into a coded_packet and send it | |
1032 | * @bat_priv: the bat priv with all the soft interface information | |
1033 | * @skb: data skb to forward | |
1034 | * @ethhdr: pointer to the ethernet header inside the skb | |
1035 | * @nc_packet: structure containing the packet to the skb can be coded with | |
1036 | * @neigh_node: next hop to forward packet to | |
1037 | * | |
62fe710f | 1038 | * Return: true if both packets are consumed, false otherwise. |
3c12de9a MH |
1039 | */ |
1040 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
1041 | struct sk_buff *skb, | |
1042 | struct ethhdr *ethhdr, | |
1043 | struct batadv_nc_packet *nc_packet, | |
1044 | struct batadv_neigh_node *neigh_node) | |
1045 | { | |
6b5e971a | 1046 | u8 tq_weighted_neigh, tq_weighted_coding, tq_tmp; |
3c12de9a MH |
1047 | struct sk_buff *skb_dest, *skb_src; |
1048 | struct batadv_unicast_packet *packet1; | |
1049 | struct batadv_unicast_packet *packet2; | |
1050 | struct batadv_coded_packet *coded_packet; | |
1051 | struct batadv_neigh_node *neigh_tmp, *router_neigh; | |
1052 | struct batadv_neigh_node *router_coding = NULL; | |
89652331 SW |
1053 | struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL; |
1054 | struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL; | |
6b5e971a | 1055 | u8 *first_source, *first_dest, *second_source, *second_dest; |
3c12de9a MH |
1056 | __be32 packet_id1, packet_id2; |
1057 | size_t count; | |
1058 | bool res = false; | |
1059 | int coding_len; | |
1060 | int unicast_size = sizeof(*packet1); | |
1061 | int coded_size = sizeof(*coded_packet); | |
1062 | int header_add = coded_size - unicast_size; | |
1063 | ||
7351a482 SW |
1064 | /* TODO: do we need to consider the outgoing interface for |
1065 | * coded packets? | |
1066 | */ | |
1067 | router_neigh = batadv_orig_router_get(neigh_node->orig_node, | |
1068 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1069 | if (!router_neigh) |
1070 | goto out; | |
1071 | ||
89652331 SW |
1072 | router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh, |
1073 | BATADV_IF_DEFAULT); | |
1074 | if (!router_neigh_ifinfo) | |
1075 | goto out; | |
1076 | ||
3c12de9a | 1077 | neigh_tmp = nc_packet->neigh_node; |
7351a482 SW |
1078 | router_coding = batadv_orig_router_get(neigh_tmp->orig_node, |
1079 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1080 | if (!router_coding) |
1081 | goto out; | |
1082 | ||
89652331 SW |
1083 | router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding, |
1084 | BATADV_IF_DEFAULT); | |
1085 | if (!router_coding_ifinfo) | |
1086 | goto out; | |
1087 | ||
1088 | tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg; | |
1089 | tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp); | |
1090 | tq_tmp = router_coding_ifinfo->bat_iv.tq_avg; | |
1091 | tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp); | |
3c12de9a MH |
1092 | |
1093 | /* Select one destination for the MAC-header dst-field based on | |
1094 | * weighted TQ-values. | |
1095 | */ | |
1096 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
1097 | /* Destination from nc_packet is selected for MAC-header */ | |
1098 | first_dest = nc_packet->nc_path->next_hop; | |
1099 | first_source = nc_packet->nc_path->prev_hop; | |
1100 | second_dest = neigh_node->addr; | |
1101 | second_source = ethhdr->h_source; | |
1102 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1103 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
1104 | packet_id1 = nc_packet->packet_id; | |
1105 | packet_id2 = batadv_skb_crc32(skb, | |
1106 | skb->data + sizeof(*packet2)); | |
1107 | } else { | |
1108 | /* Destination for skb is selected for MAC-header */ | |
1109 | first_dest = neigh_node->addr; | |
1110 | first_source = ethhdr->h_source; | |
1111 | second_dest = nc_packet->nc_path->next_hop; | |
1112 | second_source = nc_packet->nc_path->prev_hop; | |
1113 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
1114 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1115 | packet_id1 = batadv_skb_crc32(skb, | |
1116 | skb->data + sizeof(*packet1)); | |
1117 | packet_id2 = nc_packet->packet_id; | |
1118 | } | |
1119 | ||
1120 | /* Instead of zero padding the smallest data buffer, we | |
1121 | * code into the largest. | |
1122 | */ | |
1123 | if (skb->len <= nc_packet->skb->len) { | |
1124 | skb_dest = nc_packet->skb; | |
1125 | skb_src = skb; | |
1126 | } else { | |
1127 | skb_dest = skb; | |
1128 | skb_src = nc_packet->skb; | |
1129 | } | |
1130 | ||
1131 | /* coding_len is used when decoding the packet shorter packet */ | |
1132 | coding_len = skb_src->len - unicast_size; | |
1133 | ||
1134 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1135 | goto out; | |
1136 | ||
1137 | skb_push(skb_dest, header_add); | |
1138 | ||
1139 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1140 | skb_reset_mac_header(skb_dest); | |
1141 | ||
a40d9b07 SW |
1142 | coded_packet->packet_type = BATADV_CODED; |
1143 | coded_packet->version = BATADV_COMPAT_VERSION; | |
1144 | coded_packet->ttl = packet1->ttl; | |
3c12de9a MH |
1145 | |
1146 | /* Info about first unicast packet */ | |
8fdd0153 AQ |
1147 | ether_addr_copy(coded_packet->first_source, first_source); |
1148 | ether_addr_copy(coded_packet->first_orig_dest, packet1->dest); | |
3c12de9a MH |
1149 | coded_packet->first_crc = packet_id1; |
1150 | coded_packet->first_ttvn = packet1->ttvn; | |
1151 | ||
1152 | /* Info about second unicast packet */ | |
8fdd0153 AQ |
1153 | ether_addr_copy(coded_packet->second_dest, second_dest); |
1154 | ether_addr_copy(coded_packet->second_source, second_source); | |
1155 | ether_addr_copy(coded_packet->second_orig_dest, packet2->dest); | |
3c12de9a | 1156 | coded_packet->second_crc = packet_id2; |
a40d9b07 | 1157 | coded_packet->second_ttl = packet2->ttl; |
3c12de9a MH |
1158 | coded_packet->second_ttvn = packet2->ttvn; |
1159 | coded_packet->coded_len = htons(coding_len); | |
1160 | ||
1161 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1162 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1163 | skb_src->data + unicast_size, coding_len); | |
1164 | ||
1165 | /* Update counters accordingly */ | |
1166 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1167 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1168 | /* Both packets are recoded */ | |
1169 | count = skb_src->len + ETH_HLEN; | |
1170 | count += skb_dest->len + ETH_HLEN; | |
1171 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1172 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1173 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1174 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1175 | /* Both packets are newly coded */ | |
1176 | count = skb_src->len + ETH_HLEN; | |
1177 | count += skb_dest->len + ETH_HLEN; | |
1178 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1179 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1180 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1181 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1182 | /* skb_src recoded and skb_dest is newly coded */ | |
1183 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1184 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1185 | skb_src->len + ETH_HLEN); | |
1186 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1187 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1188 | skb_dest->len + ETH_HLEN); | |
1189 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1190 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1191 | /* skb_src is newly coded and skb_dest is recoded */ | |
1192 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1193 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1194 | skb_src->len + ETH_HLEN); | |
1195 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1196 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1197 | skb_dest->len + ETH_HLEN); | |
1198 | } | |
1199 | ||
1200 | /* skb_src is now coded into skb_dest, so free it */ | |
1201 | kfree_skb(skb_src); | |
1202 | ||
1203 | /* avoid duplicate free of skb from nc_packet */ | |
1204 | nc_packet->skb = NULL; | |
1205 | batadv_nc_packet_free(nc_packet); | |
1206 | ||
1207 | /* Send the coded packet and return true */ | |
1208 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); | |
1209 | res = true; | |
1210 | out: | |
1211 | if (router_neigh) | |
1212 | batadv_neigh_node_free_ref(router_neigh); | |
1213 | if (router_coding) | |
1214 | batadv_neigh_node_free_ref(router_coding); | |
89652331 SW |
1215 | if (router_neigh_ifinfo) |
1216 | batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo); | |
1217 | if (router_coding_ifinfo) | |
1218 | batadv_neigh_ifinfo_free_ref(router_coding_ifinfo); | |
3c12de9a MH |
1219 | return res; |
1220 | } | |
1221 | ||
1222 | /** | |
1223 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. | |
1224 | * @skb: data skb to forward | |
1225 | * @dst: destination mac address of the other skb to code with | |
1226 | * @src: source mac address of skb | |
1227 | * | |
1228 | * Whenever we network code a packet we have to check whether we received it in | |
1229 | * a network coded form. If so, we may not be able to use it for coding because | |
1230 | * some neighbors may also have received (overheard) the packet in the network | |
1231 | * coded form without being able to decode it. It is hard to know which of the | |
1232 | * neighboring nodes was able to decode the packet, therefore we can only | |
1233 | * re-code the packet if the source of the previous encoded packet is involved. | |
1234 | * Since the source encoded the packet we can be certain it has all necessary | |
1235 | * decode information. | |
1236 | * | |
62fe710f | 1237 | * Return: true if coding of a decoded packet is allowed. |
3c12de9a | 1238 | */ |
6b5e971a | 1239 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, u8 *dst, u8 *src) |
3c12de9a MH |
1240 | { |
1241 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1242 | return false; | |
24820df1 | 1243 | return true; |
3c12de9a MH |
1244 | } |
1245 | ||
1246 | /** | |
1247 | * batadv_nc_path_search - Find the coding path matching in_nc_node and | |
1248 | * out_nc_node to retrieve a buffered packet that can be used for coding. | |
1249 | * @bat_priv: the bat priv with all the soft interface information | |
1250 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1251 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1252 | * @skb: data skb to forward | |
1253 | * @eth_dst: next hop mac address of skb | |
1254 | * | |
62fe710f | 1255 | * Return: true if coding of a decoded skb is allowed. |
3c12de9a MH |
1256 | */ |
1257 | static struct batadv_nc_packet * | |
1258 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1259 | struct batadv_nc_node *in_nc_node, | |
1260 | struct batadv_nc_node *out_nc_node, | |
1261 | struct sk_buff *skb, | |
6b5e971a | 1262 | u8 *eth_dst) |
3c12de9a MH |
1263 | { |
1264 | struct batadv_nc_path *nc_path, nc_path_key; | |
1265 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1266 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1267 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1268 | int idx; | |
1269 | ||
1270 | if (!hash) | |
1271 | return NULL; | |
1272 | ||
1273 | /* Create almost path key */ | |
1274 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1275 | out_nc_node->addr); | |
1276 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1277 | ||
1278 | /* Check for coding opportunities in this nc_path */ | |
1279 | rcu_read_lock(); | |
1280 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1281 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1282 | continue; | |
1283 | ||
1284 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1285 | continue; | |
1286 | ||
1287 | spin_lock_bh(&nc_path->packet_list_lock); | |
1288 | if (list_empty(&nc_path->packet_list)) { | |
1289 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1290 | continue; | |
1291 | } | |
1292 | ||
1293 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1294 | &nc_path->packet_list, list) { | |
1295 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1296 | eth_dst, | |
1297 | in_nc_node->addr)) | |
1298 | continue; | |
1299 | ||
1300 | /* Coding opportunity is found! */ | |
1301 | list_del(&nc_packet->list); | |
1302 | nc_packet_out = nc_packet; | |
1303 | break; | |
1304 | } | |
1305 | ||
1306 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1307 | break; | |
1308 | } | |
1309 | rcu_read_unlock(); | |
1310 | ||
1311 | return nc_packet_out; | |
1312 | } | |
1313 | ||
1314 | /** | |
1315 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the | |
1316 | * skb's sender (may be equal to the originator). | |
1317 | * @bat_priv: the bat priv with all the soft interface information | |
1318 | * @skb: data skb to forward | |
1319 | * @eth_dst: next hop mac address of skb | |
1320 | * @eth_src: source mac address of skb | |
1321 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1322 | * | |
62fe710f | 1323 | * Return: an nc packet if a suitable coding packet was found, NULL otherwise. |
3c12de9a MH |
1324 | */ |
1325 | static struct batadv_nc_packet * | |
1326 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1327 | struct sk_buff *skb, | |
6b5e971a SE |
1328 | u8 *eth_dst, |
1329 | u8 *eth_src, | |
3c12de9a MH |
1330 | struct batadv_nc_node *in_nc_node) |
1331 | { | |
1332 | struct batadv_orig_node *orig_node; | |
1333 | struct batadv_nc_node *out_nc_node; | |
1334 | struct batadv_nc_packet *nc_packet = NULL; | |
1335 | ||
1336 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1337 | if (!orig_node) | |
1338 | return NULL; | |
1339 | ||
1340 | rcu_read_lock(); | |
1341 | list_for_each_entry_rcu(out_nc_node, | |
1342 | &orig_node->out_coding_list, list) { | |
1343 | /* Check if the skb is decoded and if recoding is possible */ | |
1344 | if (!batadv_nc_skb_coding_possible(skb, | |
1345 | out_nc_node->addr, eth_src)) | |
1346 | continue; | |
1347 | ||
1348 | /* Search for an opportunity in this nc_path */ | |
1349 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1350 | out_nc_node, skb, eth_dst); | |
1351 | if (nc_packet) | |
1352 | break; | |
1353 | } | |
1354 | rcu_read_unlock(); | |
1355 | ||
1356 | batadv_orig_node_free_ref(orig_node); | |
1357 | return nc_packet; | |
1358 | } | |
1359 | ||
612d2b4f MH |
1360 | /** |
1361 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the | |
1362 | * unicast skb before it is stored for use in later decoding | |
1363 | * @bat_priv: the bat priv with all the soft interface information | |
1364 | * @skb: data skb to store | |
1365 | * @eth_dst_new: new destination mac address of skb | |
1366 | */ | |
1367 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1368 | struct sk_buff *skb, | |
6b5e971a | 1369 | u8 *eth_dst_new) |
612d2b4f MH |
1370 | { |
1371 | struct ethhdr *ethhdr; | |
1372 | ||
1373 | /* Copy skb header to change the mac header */ | |
bad93e9d | 1374 | skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
612d2b4f MH |
1375 | if (!skb) |
1376 | return; | |
1377 | ||
1378 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1379 | ethhdr = eth_hdr(skb); |
8fdd0153 AQ |
1380 | ether_addr_copy(ethhdr->h_source, ethhdr->h_dest); |
1381 | ether_addr_copy(ethhdr->h_dest, eth_dst_new); | |
612d2b4f MH |
1382 | |
1383 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1384 | skb_push(skb, ETH_HLEN); | |
1385 | ||
1386 | /* Add the packet to the decoding packet pool */ | |
1387 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1388 | ||
1389 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1390 | * our ref | |
1391 | */ | |
1392 | kfree_skb(skb); | |
1393 | } | |
1394 | ||
3c12de9a MH |
1395 | /** |
1396 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. | |
1397 | * @skb: data skb to forward | |
1398 | * @neigh_node: next hop to forward packet to | |
1399 | * @ethhdr: pointer to the ethernet header inside the skb | |
1400 | * | |
1401 | * Loops through list of neighboring nodes the next hop has a good connection to | |
1402 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our | |
1403 | * next hop that potentially sent a packet which our next hop also received | |
1404 | * (overheard) and has stored for later decoding. | |
1405 | * | |
62fe710f | 1406 | * Return: true if the skb was consumed (encoded packet sent) or false otherwise |
3c12de9a MH |
1407 | */ |
1408 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1409 | struct batadv_neigh_node *neigh_node, | |
1410 | struct ethhdr *ethhdr) | |
1411 | { | |
1412 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1413 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1414 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1415 | struct batadv_nc_node *nc_node; | |
1416 | struct batadv_nc_packet *nc_packet = NULL; | |
1417 | ||
1418 | rcu_read_lock(); | |
1419 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1420 | /* Search for coding opportunity with this in_nc_node */ | |
1421 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1422 | neigh_node->addr, | |
1423 | ethhdr->h_source, nc_node); | |
1424 | ||
1425 | /* Opportunity was found, so stop searching */ | |
1426 | if (nc_packet) | |
1427 | break; | |
1428 | } | |
1429 | rcu_read_unlock(); | |
1430 | ||
1431 | if (!nc_packet) | |
1432 | return false; | |
1433 | ||
612d2b4f MH |
1434 | /* Save packets for later decoding */ |
1435 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1436 | neigh_node->addr); | |
1437 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1438 | nc_packet->neigh_node->addr); | |
1439 | ||
3c12de9a MH |
1440 | /* Code and send packets */ |
1441 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1442 | neigh_node)) | |
1443 | return true; | |
1444 | ||
1445 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1446 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1447 | * by the calling function. | |
1448 | */ | |
1449 | batadv_nc_send_packet(nc_packet); | |
1450 | return false; | |
1451 | } | |
1452 | ||
95332477 MH |
1453 | /** |
1454 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding | |
1455 | * @skb: skb to add to path | |
1456 | * @nc_path: path to add skb to | |
1457 | * @neigh_node: next hop to forward packet to | |
1458 | * @packet_id: checksum to identify packet | |
1459 | * | |
62fe710f | 1460 | * Return: true if the packet was buffered or false in case of an error. |
95332477 MH |
1461 | */ |
1462 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1463 | struct batadv_nc_path *nc_path, | |
1464 | struct batadv_neigh_node *neigh_node, | |
1465 | __be32 packet_id) | |
1466 | { | |
1467 | struct batadv_nc_packet *nc_packet; | |
1468 | ||
1469 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1470 | if (!nc_packet) | |
1471 | return false; | |
1472 | ||
1473 | /* Initialize nc_packet */ | |
1474 | nc_packet->timestamp = jiffies; | |
1475 | nc_packet->packet_id = packet_id; | |
1476 | nc_packet->skb = skb; | |
1477 | nc_packet->neigh_node = neigh_node; | |
1478 | nc_packet->nc_path = nc_path; | |
1479 | ||
1480 | /* Add coding packet to list */ | |
1481 | spin_lock_bh(&nc_path->packet_list_lock); | |
1482 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1483 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1484 | ||
1485 | return true; | |
1486 | } | |
1487 | ||
1488 | /** | |
1489 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet | |
1490 | * buffer | |
1491 | * @skb: data skb to forward | |
1492 | * @neigh_node: next hop to forward packet to | |
95332477 | 1493 | * |
62fe710f | 1494 | * Return: true if the skb was consumed (encoded packet sent) or false otherwise |
95332477 MH |
1495 | */ |
1496 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
e91ecfc6 | 1497 | struct batadv_neigh_node *neigh_node) |
95332477 MH |
1498 | { |
1499 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1500 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1501 | struct batadv_unicast_packet *packet; | |
1502 | struct batadv_nc_path *nc_path; | |
e91ecfc6 | 1503 | struct ethhdr *ethhdr = eth_hdr(skb); |
95332477 MH |
1504 | __be32 packet_id; |
1505 | u8 *payload; | |
1506 | ||
1507 | /* Check if network coding is enabled */ | |
1508 | if (!atomic_read(&bat_priv->network_coding)) | |
1509 | goto out; | |
1510 | ||
1511 | /* We only handle unicast packets */ | |
1512 | payload = skb_network_header(skb); | |
1513 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1514 | if (packet->packet_type != BATADV_UNICAST) |
95332477 MH |
1515 | goto out; |
1516 | ||
3c12de9a MH |
1517 | /* Try to find a coding opportunity and send the skb if one is found */ |
1518 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1519 | return true; | |
1520 | ||
95332477 MH |
1521 | /* Find or create a nc_path for this src-dst pair */ |
1522 | nc_path = batadv_nc_get_path(bat_priv, | |
1523 | bat_priv->nc.coding_hash, | |
1524 | ethhdr->h_source, | |
1525 | neigh_node->addr); | |
1526 | ||
1527 | if (!nc_path) | |
1528 | goto out; | |
1529 | ||
1530 | /* Add skb to nc_path */ | |
1531 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1532 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1533 | goto free_nc_path; | |
1534 | ||
1535 | /* Packet is consumed */ | |
1536 | return true; | |
1537 | ||
1538 | free_nc_path: | |
1539 | batadv_nc_path_free_ref(nc_path); | |
1540 | out: | |
1541 | /* Packet is not consumed */ | |
1542 | return false; | |
1543 | } | |
1544 | ||
612d2b4f MH |
1545 | /** |
1546 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used | |
1547 | * when decoding coded packets | |
1548 | * @bat_priv: the bat priv with all the soft interface information | |
1549 | * @skb: data skb to store | |
1550 | */ | |
1551 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1552 | struct sk_buff *skb) | |
1553 | { | |
1554 | struct batadv_unicast_packet *packet; | |
1555 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1556 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1557 | __be32 packet_id; |
1558 | u8 *payload; | |
1559 | ||
1560 | /* Check if network coding is enabled */ | |
1561 | if (!atomic_read(&bat_priv->network_coding)) | |
1562 | goto out; | |
1563 | ||
1564 | /* Check for supported packet type */ | |
1565 | payload = skb_network_header(skb); | |
1566 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1567 | if (packet->packet_type != BATADV_UNICAST) |
612d2b4f MH |
1568 | goto out; |
1569 | ||
1570 | /* Find existing nc_path or create a new */ | |
1571 | nc_path = batadv_nc_get_path(bat_priv, | |
1572 | bat_priv->nc.decoding_hash, | |
1573 | ethhdr->h_source, | |
1574 | ethhdr->h_dest); | |
1575 | ||
1576 | if (!nc_path) | |
1577 | goto out; | |
1578 | ||
1579 | /* Clone skb and adjust skb->data to point at batman header */ | |
1580 | skb = skb_clone(skb, GFP_ATOMIC); | |
1581 | if (unlikely(!skb)) | |
1582 | goto free_nc_path; | |
1583 | ||
1584 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1585 | goto free_skb; | |
1586 | ||
1587 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1588 | goto free_skb; | |
1589 | ||
1590 | /* Add skb to nc_path */ | |
1591 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1592 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1593 | goto free_skb; | |
1594 | ||
1595 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1596 | return; | |
1597 | ||
1598 | free_skb: | |
1599 | kfree_skb(skb); | |
1600 | free_nc_path: | |
1601 | batadv_nc_path_free_ref(nc_path); | |
1602 | out: | |
1603 | return; | |
1604 | } | |
1605 | ||
1606 | /** | |
1607 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet | |
1608 | * should be saved in the decoding buffer and, if so, store it there | |
1609 | * @bat_priv: the bat priv with all the soft interface information | |
1610 | * @skb: unicast skb to store | |
1611 | */ | |
1612 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1613 | struct sk_buff *skb) | |
1614 | { | |
7ed4be95 | 1615 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1616 | |
6e0895c2 | 1617 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1618 | return; |
1619 | ||
1620 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1621 | skb_push(skb, ETH_HLEN); | |
1622 | ||
1623 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1624 | } | |
1625 | ||
2df5278b MH |
1626 | /** |
1627 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored | |
1628 | * in nc_packet | |
6e0895c2 | 1629 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1630 | * @skb: unicast skb to decode |
1631 | * @nc_packet: decode data needed to decode the skb | |
1632 | * | |
62fe710f | 1633 | * Return: pointer to decoded unicast packet if the packet was decoded or NULL |
2df5278b MH |
1634 | * in case of an error. |
1635 | */ | |
1636 | static struct batadv_unicast_packet * | |
6e0895c2 | 1637 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1638 | struct batadv_nc_packet *nc_packet) |
1639 | { | |
1640 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1641 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1642 | struct batadv_unicast_packet *unicast_packet; | |
1643 | struct batadv_coded_packet coded_packet_tmp; | |
1644 | struct ethhdr *ethhdr, ethhdr_tmp; | |
6b5e971a | 1645 | u8 *orig_dest, ttl, ttvn; |
2df5278b | 1646 | unsigned int coding_len; |
7da19971 | 1647 | int err; |
2df5278b MH |
1648 | |
1649 | /* Save headers temporarily */ | |
1650 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1651 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1652 | ||
1653 | if (skb_cow(skb, 0) < 0) | |
1654 | return NULL; | |
1655 | ||
1656 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1657 | return NULL; | |
1658 | ||
1659 | /* Data points to batman header, so set mac header 14 bytes before | |
1660 | * and network to data | |
1661 | */ | |
1662 | skb_set_mac_header(skb, -ETH_HLEN); | |
1663 | skb_reset_network_header(skb); | |
1664 | ||
1665 | /* Reconstruct original mac header */ | |
7ed4be95 | 1666 | ethhdr = eth_hdr(skb); |
abae9479 | 1667 | *ethhdr = ethhdr_tmp; |
2df5278b MH |
1668 | |
1669 | /* Select the correct unicast header information based on the location | |
1670 | * of our mac address in the coded_packet header | |
1671 | */ | |
6e0895c2 | 1672 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1673 | /* If we are the second destination the packet was overheard, |
1674 | * so the Ethernet address must be copied to h_dest and | |
1675 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1676 | */ | |
8fdd0153 | 1677 | ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest); |
2df5278b MH |
1678 | skb->pkt_type = PACKET_HOST; |
1679 | ||
1680 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1681 | ttl = coded_packet_tmp.second_ttl; | |
1682 | ttvn = coded_packet_tmp.second_ttvn; | |
1683 | } else { | |
1684 | orig_dest = coded_packet_tmp.first_orig_dest; | |
a40d9b07 | 1685 | ttl = coded_packet_tmp.ttl; |
2df5278b MH |
1686 | ttvn = coded_packet_tmp.first_ttvn; |
1687 | } | |
1688 | ||
1689 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1690 | ||
1691 | if (coding_len > skb->len) | |
1692 | return NULL; | |
1693 | ||
1694 | /* Here the magic is reversed: | |
1695 | * extract the missing packet from the received coded packet | |
1696 | */ | |
1697 | batadv_nc_memxor(skb->data + h_size, | |
1698 | nc_packet->skb->data + h_size, | |
1699 | coding_len); | |
1700 | ||
1701 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1702 | if (nc_packet->skb->len > coding_len + h_size) { |
1703 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1704 | if (err) | |
1705 | return NULL; | |
1706 | } | |
2df5278b MH |
1707 | |
1708 | /* Create decoded unicast packet */ | |
1709 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
a40d9b07 SW |
1710 | unicast_packet->packet_type = BATADV_UNICAST; |
1711 | unicast_packet->version = BATADV_COMPAT_VERSION; | |
1712 | unicast_packet->ttl = ttl; | |
8fdd0153 | 1713 | ether_addr_copy(unicast_packet->dest, orig_dest); |
2df5278b MH |
1714 | unicast_packet->ttvn = ttvn; |
1715 | ||
1716 | batadv_nc_packet_free(nc_packet); | |
1717 | return unicast_packet; | |
1718 | } | |
1719 | ||
1720 | /** | |
1721 | * batadv_nc_find_decoding_packet - search through buffered decoding data to | |
1722 | * find the data needed to decode the coded packet | |
1723 | * @bat_priv: the bat priv with all the soft interface information | |
1724 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1725 | * @coded: coded packet we try to find decode data for | |
1726 | * | |
62fe710f | 1727 | * Return: pointer to nc packet if the needed data was found or NULL otherwise. |
2df5278b MH |
1728 | */ |
1729 | static struct batadv_nc_packet * | |
1730 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1731 | struct ethhdr *ethhdr, | |
1732 | struct batadv_coded_packet *coded) | |
1733 | { | |
1734 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1735 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1736 | struct batadv_nc_path *nc_path, nc_path_key; | |
6b5e971a | 1737 | u8 *dest, *source; |
2df5278b MH |
1738 | __be32 packet_id; |
1739 | int index; | |
1740 | ||
1741 | if (!hash) | |
1742 | return NULL; | |
1743 | ||
1744 | /* Select the correct packet id based on the location of our mac-addr */ | |
1745 | dest = ethhdr->h_source; | |
6e0895c2 | 1746 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1747 | source = coded->second_source; |
1748 | packet_id = coded->second_crc; | |
1749 | } else { | |
1750 | source = coded->first_source; | |
1751 | packet_id = coded->first_crc; | |
1752 | } | |
1753 | ||
1754 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1755 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1756 | ||
1757 | /* Search for matching coding path */ | |
1758 | rcu_read_lock(); | |
1759 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1760 | /* Find matching nc_packet */ | |
1761 | spin_lock_bh(&nc_path->packet_list_lock); | |
1762 | list_for_each_entry(tmp_nc_packet, | |
1763 | &nc_path->packet_list, list) { | |
1764 | if (packet_id == tmp_nc_packet->packet_id) { | |
1765 | list_del(&tmp_nc_packet->list); | |
1766 | ||
1767 | nc_packet = tmp_nc_packet; | |
1768 | break; | |
1769 | } | |
1770 | } | |
1771 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1772 | ||
1773 | if (nc_packet) | |
1774 | break; | |
1775 | } | |
1776 | rcu_read_unlock(); | |
1777 | ||
1778 | if (!nc_packet) | |
1779 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1780 | "No decoding packet found for %u\n", packet_id); | |
1781 | ||
1782 | return nc_packet; | |
1783 | } | |
1784 | ||
1785 | /** | |
1786 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the | |
1787 | * resulting unicast packet | |
1788 | * @skb: incoming coded packet | |
1789 | * @recv_if: pointer to interface this packet was received on | |
672e7978 SE |
1790 | * |
1791 | * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP | |
1792 | * otherwise. | |
2df5278b MH |
1793 | */ |
1794 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1795 | struct batadv_hard_iface *recv_if) | |
1796 | { | |
1797 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1798 | struct batadv_unicast_packet *unicast_packet; | |
1799 | struct batadv_coded_packet *coded_packet; | |
1800 | struct batadv_nc_packet *nc_packet; | |
1801 | struct ethhdr *ethhdr; | |
1802 | int hdr_size = sizeof(*coded_packet); | |
1803 | ||
1804 | /* Check if network coding is enabled */ | |
1805 | if (!atomic_read(&bat_priv->network_coding)) | |
1806 | return NET_RX_DROP; | |
1807 | ||
1808 | /* Make sure we can access (and remove) header */ | |
1809 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
1810 | return NET_RX_DROP; | |
1811 | ||
1812 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1813 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1814 | |
1815 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1816 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1817 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
2df5278b MH |
1818 | return NET_RX_DROP; |
1819 | ||
1820 | /* Update stat counter */ | |
6e0895c2 | 1821 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1822 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1823 | ||
1824 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1825 | coded_packet); | |
1826 | if (!nc_packet) { | |
1827 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1828 | return NET_RX_DROP; | |
1829 | } | |
1830 | ||
1831 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1832 | if (skb_linearize(skb) < 0) | |
1833 | goto free_nc_packet; | |
1834 | ||
1835 | if (skb_linearize(nc_packet->skb) < 0) | |
1836 | goto free_nc_packet; | |
1837 | ||
1838 | /* Decode the packet */ | |
6e0895c2 | 1839 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1840 | if (!unicast_packet) { |
1841 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1842 | goto free_nc_packet; | |
1843 | } | |
1844 | ||
1845 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1846 | BATADV_SKB_CB(skb)->decoded = true; | |
1847 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1848 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1849 | skb->len + ETH_HLEN); | |
1850 | return batadv_recv_unicast_packet(skb, recv_if); | |
1851 | ||
1852 | free_nc_packet: | |
1853 | batadv_nc_packet_free(nc_packet); | |
1854 | return NET_RX_DROP; | |
1855 | } | |
1856 | ||
d353d8d4 | 1857 | /** |
6c519bad | 1858 | * batadv_nc_mesh_free - clean up network coding memory |
d353d8d4 MH |
1859 | * @bat_priv: the bat priv with all the soft interface information |
1860 | */ | |
6c519bad | 1861 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
d353d8d4 | 1862 | { |
3f4841ff ML |
1863 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1864 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
d353d8d4 | 1865 | cancel_delayed_work_sync(&bat_priv->nc.work); |
612d2b4f | 1866 | |
95332477 MH |
1867 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1868 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1869 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1870 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1871 | } |
d56b1705 MH |
1872 | |
1873 | /** | |
1874 | * batadv_nc_nodes_seq_print_text - print the nc node information | |
1875 | * @seq: seq file to print on | |
1876 | * @offset: not used | |
672e7978 SE |
1877 | * |
1878 | * Return: always 0 | |
d56b1705 MH |
1879 | */ |
1880 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) | |
1881 | { | |
1882 | struct net_device *net_dev = (struct net_device *)seq->private; | |
1883 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
1884 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
1885 | struct batadv_hard_iface *primary_if; | |
1886 | struct hlist_head *head; | |
1887 | struct batadv_orig_node *orig_node; | |
1888 | struct batadv_nc_node *nc_node; | |
1889 | int i; | |
1890 | ||
1891 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
1892 | if (!primary_if) | |
1893 | goto out; | |
1894 | ||
1895 | /* Traverse list of originators */ | |
1896 | for (i = 0; i < hash->size; i++) { | |
1897 | head = &hash->table[i]; | |
1898 | ||
1899 | /* For each orig_node in this bin */ | |
1900 | rcu_read_lock(); | |
1901 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { | |
aa27c312 ML |
1902 | /* no need to print the orig node if it does not have |
1903 | * network coding neighbors | |
1904 | */ | |
1905 | if (list_empty(&orig_node->in_coding_list) && | |
1906 | list_empty(&orig_node->out_coding_list)) | |
1907 | continue; | |
1908 | ||
d56b1705 MH |
1909 | seq_printf(seq, "Node: %pM\n", orig_node->orig); |
1910 | ||
0c814653 | 1911 | seq_puts(seq, " Ingoing: "); |
d56b1705 MH |
1912 | /* For each in_nc_node to this orig_node */ |
1913 | list_for_each_entry_rcu(nc_node, | |
1914 | &orig_node->in_coding_list, | |
1915 | list) | |
1916 | seq_printf(seq, "%pM ", | |
1917 | nc_node->addr); | |
0c814653 | 1918 | seq_puts(seq, "\n"); |
d56b1705 | 1919 | |
0c814653 | 1920 | seq_puts(seq, " Outgoing: "); |
d56b1705 MH |
1921 | /* For out_nc_node to this orig_node */ |
1922 | list_for_each_entry_rcu(nc_node, | |
1923 | &orig_node->out_coding_list, | |
1924 | list) | |
1925 | seq_printf(seq, "%pM ", | |
1926 | nc_node->addr); | |
0c814653 | 1927 | seq_puts(seq, "\n\n"); |
d56b1705 MH |
1928 | } |
1929 | rcu_read_unlock(); | |
1930 | } | |
1931 | ||
1932 | out: | |
1933 | if (primary_if) | |
1934 | batadv_hardif_free_ref(primary_if); | |
1935 | return 0; | |
1936 | } | |
1937 | ||
1938 | /** | |
1939 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs | |
1940 | * @bat_priv: the bat priv with all the soft interface information | |
672e7978 SE |
1941 | * |
1942 | * Return: 0 on success or negative error number in case of failure | |
d56b1705 MH |
1943 | */ |
1944 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) | |
1945 | { | |
1946 | struct dentry *nc_dir, *file; | |
1947 | ||
1948 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); | |
1949 | if (!nc_dir) | |
1950 | goto out; | |
1951 | ||
1952 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, | |
1953 | &bat_priv->nc.min_tq); | |
1954 | if (!file) | |
1955 | goto out; | |
1956 | ||
95332477 MH |
1957 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1958 | &bat_priv->nc.max_fwd_delay); | |
1959 | if (!file) | |
1960 | goto out; | |
1961 | ||
612d2b4f MH |
1962 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1963 | &bat_priv->nc.max_buffer_time); | |
1964 | if (!file) | |
1965 | goto out; | |
1966 | ||
d56b1705 MH |
1967 | return 0; |
1968 | ||
1969 | out: | |
1970 | return -ENOMEM; | |
1971 | } |