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7db7d9f3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
cfa55c6d | 2 | /* Copyright (C) B.A.T.M.A.N. contributors: |
d353d8d4 MH |
3 | * |
4 | * Martin Hundebøll, Jeppe Ledet-Pedersen | |
d353d8d4 MH |
5 | */ |
6 | ||
1e2c2a4f SE |
7 | #include "network-coding.h" |
8 | #include "main.h" | |
9 | ||
10 | #include <linux/atomic.h> | |
4635469f | 11 | #include <linux/bitops.h> |
1e2c2a4f SE |
12 | #include <linux/byteorder/generic.h> |
13 | #include <linux/compiler.h> | |
eb7da4f1 | 14 | #include <linux/container_of.h> |
1e2c2a4f SE |
15 | #include <linux/errno.h> |
16 | #include <linux/etherdevice.h> | |
b92b94ac | 17 | #include <linux/gfp.h> |
1e2c2a4f SE |
18 | #include <linux/if_ether.h> |
19 | #include <linux/if_packet.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/jhash.h> | |
22 | #include <linux/jiffies.h> | |
daf99b48 | 23 | #include <linux/kref.h> |
1e2c2a4f SE |
24 | #include <linux/list.h> |
25 | #include <linux/lockdep.h> | |
3a64469e | 26 | #include <linux/net.h> |
1e2c2a4f | 27 | #include <linux/netdevice.h> |
0093870a | 28 | #include <linux/prandom.h> |
1e2c2a4f | 29 | #include <linux/printk.h> |
1e2c2a4f SE |
30 | #include <linux/rculist.h> |
31 | #include <linux/rcupdate.h> | |
1e2c2a4f SE |
32 | #include <linux/skbuff.h> |
33 | #include <linux/slab.h> | |
34 | #include <linux/spinlock.h> | |
1e2c2a4f SE |
35 | #include <linux/stddef.h> |
36 | #include <linux/string.h> | |
37 | #include <linux/workqueue.h> | |
fec149f5 | 38 | #include <uapi/linux/batadv_packet.h> |
d56b1705 | 39 | |
95332477 | 40 | #include "hash.h" |
ba412080 | 41 | #include "log.h" |
d56b1705 | 42 | #include "originator.h" |
2df5278b | 43 | #include "routing.h" |
1e2c2a4f | 44 | #include "send.h" |
1f8dce49 | 45 | #include "tvlv.h" |
d353d8d4 | 46 | |
95332477 | 47 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
612d2b4f | 48 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
95332477 | 49 | |
d353d8d4 | 50 | static void batadv_nc_worker(struct work_struct *work); |
2df5278b MH |
51 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
52 | struct batadv_hard_iface *recv_if); | |
d353d8d4 | 53 | |
6c519bad | 54 | /** |
7e9a8c2c | 55 | * batadv_nc_init() - one-time initialization for network coding |
672e7978 SE |
56 | * |
57 | * Return: 0 on success or negative error number in case of failure | |
6c519bad MS |
58 | */ |
59 | int __init batadv_nc_init(void) | |
60 | { | |
6c519bad | 61 | /* Register our packet type */ |
cde3fac5 MC |
62 | return batadv_recv_handler_register(BATADV_CODED, |
63 | batadv_nc_recv_coded_packet); | |
6c519bad MS |
64 | } |
65 | ||
d353d8d4 | 66 | /** |
7e9a8c2c | 67 | * batadv_nc_start_timer() - initialise the nc periodic worker |
d353d8d4 MH |
68 | * @bat_priv: the bat priv with all the soft interface information |
69 | */ | |
70 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
71 | { | |
72 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
73 | msecs_to_jiffies(10)); | |
74 | } | |
75 | ||
3f4841ff | 76 | /** |
7e9a8c2c | 77 | * batadv_nc_tvlv_container_update() - update the network coding tvlv container |
3f4841ff ML |
78 | * after network coding setting change |
79 | * @bat_priv: the bat priv with all the soft interface information | |
80 | */ | |
81 | static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv) | |
82 | { | |
83 | char nc_mode; | |
84 | ||
85 | nc_mode = atomic_read(&bat_priv->network_coding); | |
86 | ||
87 | switch (nc_mode) { | |
88 | case 0: | |
89 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
90 | break; | |
91 | case 1: | |
92 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1, | |
93 | NULL, 0); | |
94 | break; | |
95 | } | |
96 | } | |
97 | ||
98 | /** | |
7e9a8c2c | 99 | * batadv_nc_status_update() - update the network coding tvlv container after |
3f4841ff ML |
100 | * network coding setting change |
101 | * @net_dev: the soft interface net device | |
102 | */ | |
103 | void batadv_nc_status_update(struct net_device *net_dev) | |
104 | { | |
105 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 106 | |
3f4841ff ML |
107 | batadv_nc_tvlv_container_update(bat_priv); |
108 | } | |
109 | ||
110 | /** | |
7e9a8c2c | 111 | * batadv_nc_tvlv_ogm_handler_v1() - process incoming nc tvlv container |
3f4841ff ML |
112 | * @bat_priv: the bat priv with all the soft interface information |
113 | * @orig: the orig_node of the ogm | |
114 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
115 | * @tvlv_value: tvlv buffer containing the gateway data | |
116 | * @tvlv_value_len: tvlv buffer length | |
117 | */ | |
118 | static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
119 | struct batadv_orig_node *orig, | |
6b5e971a SE |
120 | u8 flags, |
121 | void *tvlv_value, u16 tvlv_value_len) | |
3f4841ff ML |
122 | { |
123 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
4635469f | 124 | clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); |
3f4841ff | 125 | else |
4635469f | 126 | set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); |
3f4841ff ML |
127 | } |
128 | ||
d353d8d4 | 129 | /** |
bccb48c8 | 130 | * batadv_nc_mesh_init() - initialise coding hash table and start housekeeping |
d353d8d4 | 131 | * @bat_priv: the bat priv with all the soft interface information |
672e7978 SE |
132 | * |
133 | * Return: 0 on success or negative error number in case of failure | |
d353d8d4 | 134 | */ |
6c519bad | 135 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
d353d8d4 | 136 | { |
95332477 | 137 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 138 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 139 | |
612d2b4f | 140 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
141 | return 0; |
142 | ||
143 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
144 | if (!bat_priv->nc.coding_hash) | |
145 | goto err; | |
146 | ||
147 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
148 | &batadv_nc_coding_hash_lock_class_key); | |
149 | ||
612d2b4f | 150 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
6f68cd63 PS |
151 | if (!bat_priv->nc.decoding_hash) { |
152 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f | 153 | goto err; |
6f68cd63 | 154 | } |
612d2b4f | 155 | |
f44d5407 | 156 | batadv_hash_set_lock_class(bat_priv->nc.decoding_hash, |
612d2b4f MH |
157 | &batadv_nc_decoding_hash_lock_class_key); |
158 | ||
d353d8d4 MH |
159 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
160 | batadv_nc_start_timer(bat_priv); | |
161 | ||
3f4841ff ML |
162 | batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1, |
163 | NULL, BATADV_TVLV_NC, 1, | |
164 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
165 | batadv_nc_tvlv_container_update(bat_priv); | |
d353d8d4 | 166 | return 0; |
95332477 MH |
167 | |
168 | err: | |
169 | return -ENOMEM; | |
d353d8d4 MH |
170 | } |
171 | ||
172 | /** | |
7e9a8c2c | 173 | * batadv_nc_init_bat_priv() - initialise the nc specific bat_priv variables |
d353d8d4 MH |
174 | * @bat_priv: the bat priv with all the soft interface information |
175 | */ | |
176 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
177 | { | |
dab7b621 | 178 | atomic_set(&bat_priv->network_coding, 0); |
d56b1705 | 179 | bat_priv->nc.min_tq = 200; |
95332477 | 180 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 181 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
182 | } |
183 | ||
184 | /** | |
7e9a8c2c | 185 | * batadv_nc_init_orig() - initialise the nc fields of an orig_node |
d56b1705 MH |
186 | * @orig_node: the orig_node which is going to be initialised |
187 | */ | |
188 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
189 | { | |
190 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
191 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
192 | spin_lock_init(&orig_node->in_coding_list_lock); | |
193 | spin_lock_init(&orig_node->out_coding_list_lock); | |
194 | } | |
195 | ||
196 | /** | |
7e9a8c2c SE |
197 | * batadv_nc_node_release() - release nc_node from lists and queue for free |
198 | * after rcu grace period | |
daf99b48 | 199 | * @ref: kref pointer of the nc_node |
d56b1705 | 200 | */ |
daf99b48 | 201 | static void batadv_nc_node_release(struct kref *ref) |
d56b1705 | 202 | { |
daf99b48 SE |
203 | struct batadv_nc_node *nc_node; |
204 | ||
205 | nc_node = container_of(ref, struct batadv_nc_node, refcount); | |
206 | ||
5d967310 | 207 | batadv_orig_node_put(nc_node->orig_node); |
44e8e7e9 | 208 | kfree_rcu(nc_node, rcu); |
d56b1705 MH |
209 | } |
210 | ||
211 | /** | |
7e9a8c2c | 212 | * batadv_nc_node_put() - decrement the nc_node refcounter and possibly |
44e8e7e9 | 213 | * release it |
daf99b48 | 214 | * @nc_node: nc_node to be free'd |
d56b1705 | 215 | */ |
27ad7545 | 216 | static void batadv_nc_node_put(struct batadv_nc_node *nc_node) |
d56b1705 | 217 | { |
6340dcbd SE |
218 | if (!nc_node) |
219 | return; | |
220 | ||
daf99b48 | 221 | kref_put(&nc_node->refcount, batadv_nc_node_release); |
d56b1705 MH |
222 | } |
223 | ||
95332477 | 224 | /** |
7e9a8c2c SE |
225 | * batadv_nc_path_release() - release nc_path from lists and queue for free |
226 | * after rcu grace period | |
727e0cd5 SE |
227 | * @ref: kref pointer of the nc_path |
228 | */ | |
229 | static void batadv_nc_path_release(struct kref *ref) | |
230 | { | |
231 | struct batadv_nc_path *nc_path; | |
232 | ||
233 | nc_path = container_of(ref, struct batadv_nc_path, refcount); | |
234 | ||
235 | kfree_rcu(nc_path, rcu); | |
236 | } | |
237 | ||
238 | /** | |
7e9a8c2c | 239 | * batadv_nc_path_put() - decrement the nc_path refcounter and possibly |
727e0cd5 SE |
240 | * release it |
241 | * @nc_path: nc_path to be free'd | |
95332477 | 242 | */ |
5fff2825 | 243 | static void batadv_nc_path_put(struct batadv_nc_path *nc_path) |
95332477 | 244 | { |
6340dcbd SE |
245 | if (!nc_path) |
246 | return; | |
247 | ||
727e0cd5 | 248 | kref_put(&nc_path->refcount, batadv_nc_path_release); |
95332477 MH |
249 | } |
250 | ||
251 | /** | |
7e9a8c2c | 252 | * batadv_nc_packet_free() - frees nc packet |
95332477 | 253 | * @nc_packet: the nc packet to free |
21ba5ab2 | 254 | * @dropped: whether the packet is freed because is dropped |
95332477 | 255 | */ |
bd687fe4 SE |
256 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet, |
257 | bool dropped) | |
95332477 | 258 | { |
bd687fe4 SE |
259 | if (dropped) |
260 | kfree_skb(nc_packet->skb); | |
261 | else | |
262 | consume_skb(nc_packet->skb); | |
263 | ||
5fff2825 | 264 | batadv_nc_path_put(nc_packet->nc_path); |
95332477 MH |
265 | kfree(nc_packet); |
266 | } | |
267 | ||
d56b1705 | 268 | /** |
7e9a8c2c | 269 | * batadv_nc_to_purge_nc_node() - checks whether an nc node has to be purged |
d56b1705 MH |
270 | * @bat_priv: the bat priv with all the soft interface information |
271 | * @nc_node: the nc node to check | |
272 | * | |
62fe710f | 273 | * Return: true if the entry has to be purged now, false otherwise |
d56b1705 MH |
274 | */ |
275 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
276 | struct batadv_nc_node *nc_node) | |
277 | { | |
278 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
279 | return true; | |
280 | ||
281 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
282 | } | |
283 | ||
95332477 | 284 | /** |
7e9a8c2c | 285 | * batadv_nc_to_purge_nc_path_coding() - checks whether an nc path has timed out |
95332477 MH |
286 | * @bat_priv: the bat priv with all the soft interface information |
287 | * @nc_path: the nc path to check | |
288 | * | |
62fe710f | 289 | * Return: true if the entry has to be purged now, false otherwise |
95332477 MH |
290 | */ |
291 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
292 | struct batadv_nc_path *nc_path) | |
293 | { | |
294 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
295 | return true; | |
296 | ||
297 | /* purge the path when no packets has been added for 10 times the | |
298 | * max_fwd_delay time | |
299 | */ | |
300 | return batadv_has_timed_out(nc_path->last_valid, | |
301 | bat_priv->nc.max_fwd_delay * 10); | |
302 | } | |
303 | ||
612d2b4f | 304 | /** |
7e9a8c2c SE |
305 | * batadv_nc_to_purge_nc_path_decoding() - checks whether an nc path has timed |
306 | * out | |
612d2b4f MH |
307 | * @bat_priv: the bat priv with all the soft interface information |
308 | * @nc_path: the nc path to check | |
309 | * | |
62fe710f | 310 | * Return: true if the entry has to be purged now, false otherwise |
612d2b4f MH |
311 | */ |
312 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
313 | struct batadv_nc_path *nc_path) | |
314 | { | |
315 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
316 | return true; | |
317 | ||
318 | /* purge the path when no packets has been added for 10 times the | |
319 | * max_buffer time | |
320 | */ | |
321 | return batadv_has_timed_out(nc_path->last_valid, | |
fc1f8693 | 322 | bat_priv->nc.max_buffer_time * 10); |
612d2b4f MH |
323 | } |
324 | ||
d56b1705 | 325 | /** |
7e9a8c2c | 326 | * batadv_nc_purge_orig_nc_nodes() - go through list of nc nodes and purge stale |
d56b1705 MH |
327 | * entries |
328 | * @bat_priv: the bat priv with all the soft interface information | |
329 | * @list: list of nc nodes | |
330 | * @lock: nc node list lock | |
331 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
332 | * not. This function takes the nc node as argument and has to return | |
333 | * a boolean value: true if the entry has to be deleted, false | |
334 | * otherwise | |
335 | */ | |
336 | static void | |
337 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
338 | struct list_head *list, | |
339 | spinlock_t *lock, | |
340 | bool (*to_purge)(struct batadv_priv *, | |
341 | struct batadv_nc_node *)) | |
342 | { | |
343 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
344 | ||
345 | /* For each nc_node in list */ | |
346 | spin_lock_bh(lock); | |
347 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
348 | /* if an helper function has been passed as parameter, | |
349 | * ask it if the entry has to be purged or not | |
350 | */ | |
351 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
352 | continue; | |
353 | ||
354 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
355 | "Removing nc_node %pM -> %pM\n", | |
356 | nc_node->addr, nc_node->orig_node->orig); | |
357 | list_del_rcu(&nc_node->list); | |
27ad7545 | 358 | batadv_nc_node_put(nc_node); |
d56b1705 MH |
359 | } |
360 | spin_unlock_bh(lock); | |
361 | } | |
362 | ||
363 | /** | |
7e9a8c2c | 364 | * batadv_nc_purge_orig() - purges all nc node data attached of the given |
d56b1705 MH |
365 | * originator |
366 | * @bat_priv: the bat priv with all the soft interface information | |
367 | * @orig_node: orig_node with the nc node entries to be purged | |
368 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
369 | * not. This function takes the nc node as argument and has to return | |
370 | * a boolean value: true is the entry has to be deleted, false | |
371 | * otherwise | |
372 | */ | |
373 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
374 | struct batadv_orig_node *orig_node, | |
375 | bool (*to_purge)(struct batadv_priv *, | |
376 | struct batadv_nc_node *)) | |
377 | { | |
378 | /* Check ingoing nc_node's of this orig_node */ | |
379 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
380 | &orig_node->in_coding_list_lock, | |
381 | to_purge); | |
382 | ||
383 | /* Check outgoing nc_node's of this orig_node */ | |
384 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
385 | &orig_node->out_coding_list_lock, | |
386 | to_purge); | |
387 | } | |
388 | ||
389 | /** | |
7e9a8c2c SE |
390 | * batadv_nc_purge_orig_hash() - traverse entire originator hash to check if |
391 | * they have timed out nc nodes | |
d56b1705 MH |
392 | * @bat_priv: the bat priv with all the soft interface information |
393 | */ | |
394 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
395 | { | |
396 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
397 | struct hlist_head *head; | |
398 | struct batadv_orig_node *orig_node; | |
6b5e971a | 399 | u32 i; |
d56b1705 MH |
400 | |
401 | if (!hash) | |
402 | return; | |
403 | ||
404 | /* For each orig_node */ | |
405 | for (i = 0; i < hash->size; i++) { | |
406 | head = &hash->table[i]; | |
407 | ||
408 | rcu_read_lock(); | |
409 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
410 | batadv_nc_purge_orig(bat_priv, orig_node, | |
411 | batadv_nc_to_purge_nc_node); | |
412 | rcu_read_unlock(); | |
413 | } | |
d353d8d4 MH |
414 | } |
415 | ||
95332477 | 416 | /** |
7e9a8c2c | 417 | * batadv_nc_purge_paths() - traverse all nc paths part of the hash and remove |
95332477 MH |
418 | * unused ones |
419 | * @bat_priv: the bat priv with all the soft interface information | |
420 | * @hash: hash table containing the nc paths to check | |
421 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
422 | * not. This function takes the nc node as argument and has to return | |
423 | * a boolean value: true is the entry has to be deleted, false | |
424 | * otherwise | |
425 | */ | |
426 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
427 | struct batadv_hashtable *hash, | |
428 | bool (*to_purge)(struct batadv_priv *, | |
429 | struct batadv_nc_path *)) | |
430 | { | |
431 | struct hlist_head *head; | |
432 | struct hlist_node *node_tmp; | |
433 | struct batadv_nc_path *nc_path; | |
434 | spinlock_t *lock; /* Protects lists in hash */ | |
6b5e971a | 435 | u32 i; |
95332477 MH |
436 | |
437 | for (i = 0; i < hash->size; i++) { | |
438 | head = &hash->table[i]; | |
439 | lock = &hash->list_locks[i]; | |
440 | ||
441 | /* For each nc_path in this bin */ | |
442 | spin_lock_bh(lock); | |
443 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
444 | /* if an helper function has been passed as parameter, | |
445 | * ask it if the entry has to be purged or not | |
446 | */ | |
447 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
448 | continue; | |
449 | ||
450 | /* purging an non-empty nc_path should never happen, but | |
451 | * is observed under high CPU load. Delay the purging | |
452 | * until next iteration to allow the packet_list to be | |
453 | * emptied first. | |
454 | */ | |
455 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
456 | net_ratelimited_function(printk, | |
457 | KERN_WARNING | |
458 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
459 | nc_path->prev_hop, | |
460 | nc_path->next_hop); | |
461 | continue; | |
462 | } | |
463 | ||
464 | /* nc_path is unused, so remove it */ | |
465 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
466 | "Remove nc_path %pM -> %pM\n", | |
467 | nc_path->prev_hop, nc_path->next_hop); | |
468 | hlist_del_rcu(&nc_path->hash_entry); | |
5fff2825 | 469 | batadv_nc_path_put(nc_path); |
95332477 MH |
470 | } |
471 | spin_unlock_bh(lock); | |
472 | } | |
473 | } | |
474 | ||
475 | /** | |
7e9a8c2c | 476 | * batadv_nc_hash_key_gen() - computes the nc_path hash key |
95332477 MH |
477 | * @key: buffer to hold the final hash key |
478 | * @src: source ethernet mac address going into the hash key | |
479 | * @dst: destination ethernet mac address going into the hash key | |
480 | */ | |
481 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
482 | const char *dst) | |
483 | { | |
484 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
485 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
486 | } | |
487 | ||
488 | /** | |
7e9a8c2c | 489 | * batadv_nc_hash_choose() - compute the hash value for an nc path |
95332477 MH |
490 | * @data: data to hash |
491 | * @size: size of the hash table | |
492 | * | |
62fe710f | 493 | * Return: the selected index in the hash table for the given data. |
95332477 | 494 | */ |
6b5e971a | 495 | static u32 batadv_nc_hash_choose(const void *data, u32 size) |
95332477 MH |
496 | { |
497 | const struct batadv_nc_path *nc_path = data; | |
6b5e971a | 498 | u32 hash = 0; |
95332477 | 499 | |
36fd61cb SE |
500 | hash = jhash(&nc_path->prev_hop, sizeof(nc_path->prev_hop), hash); |
501 | hash = jhash(&nc_path->next_hop, sizeof(nc_path->next_hop), hash); | |
95332477 MH |
502 | |
503 | return hash % size; | |
504 | } | |
505 | ||
506 | /** | |
7e9a8c2c | 507 | * batadv_nc_hash_compare() - comparing function used in the network coding hash |
95332477 MH |
508 | * tables |
509 | * @node: node in the local table | |
510 | * @data2: second object to compare the node to | |
511 | * | |
4b426b10 | 512 | * Return: true if the two entry are the same, false otherwise |
95332477 | 513 | */ |
4b426b10 SE |
514 | static bool batadv_nc_hash_compare(const struct hlist_node *node, |
515 | const void *data2) | |
95332477 MH |
516 | { |
517 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
518 | ||
519 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
520 | nc_path2 = data2; | |
521 | ||
522 | /* Return 1 if the two keys are identical */ | |
676970e5 | 523 | if (!batadv_compare_eth(nc_path1->prev_hop, nc_path2->prev_hop)) |
4b426b10 | 524 | return false; |
95332477 | 525 | |
676970e5 | 526 | if (!batadv_compare_eth(nc_path1->next_hop, nc_path2->next_hop)) |
4b426b10 | 527 | return false; |
95332477 | 528 | |
4b426b10 | 529 | return true; |
95332477 MH |
530 | } |
531 | ||
532 | /** | |
7e9a8c2c | 533 | * batadv_nc_hash_find() - search for an existing nc path and return it |
95332477 MH |
534 | * @hash: hash table containing the nc path |
535 | * @data: search key | |
536 | * | |
62fe710f | 537 | * Return: the nc_path if found, NULL otherwise. |
95332477 MH |
538 | */ |
539 | static struct batadv_nc_path * | |
540 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
541 | void *data) | |
542 | { | |
543 | struct hlist_head *head; | |
544 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
545 | int index; | |
546 | ||
547 | if (!hash) | |
548 | return NULL; | |
549 | ||
550 | index = batadv_nc_hash_choose(data, hash->size); | |
551 | head = &hash->table[index]; | |
552 | ||
553 | rcu_read_lock(); | |
554 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
555 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
556 | continue; | |
557 | ||
727e0cd5 | 558 | if (!kref_get_unless_zero(&nc_path->refcount)) |
95332477 MH |
559 | continue; |
560 | ||
561 | nc_path_tmp = nc_path; | |
562 | break; | |
563 | } | |
564 | rcu_read_unlock(); | |
565 | ||
566 | return nc_path_tmp; | |
567 | } | |
568 | ||
569 | /** | |
7e9a8c2c | 570 | * batadv_nc_send_packet() - send non-coded packet and free nc_packet struct |
95332477 MH |
571 | * @nc_packet: the nc packet to send |
572 | */ | |
573 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
574 | { | |
95d39278 | 575 | batadv_send_unicast_skb(nc_packet->skb, nc_packet->neigh_node); |
95332477 | 576 | nc_packet->skb = NULL; |
bd687fe4 | 577 | batadv_nc_packet_free(nc_packet, false); |
95332477 MH |
578 | } |
579 | ||
612d2b4f | 580 | /** |
7e9a8c2c | 581 | * batadv_nc_sniffed_purge() - Checks timestamp of given sniffed nc_packet. |
612d2b4f MH |
582 | * @bat_priv: the bat priv with all the soft interface information |
583 | * @nc_path: the nc path the packet belongs to | |
584 | * @nc_packet: the nc packet to be checked | |
585 | * | |
586 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
587 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
588 | * queue. Has to be called with the appropriate locks. | |
589 | * | |
62fe710f | 590 | * Return: false as soon as the entry in the fifo queue has not been timed out |
612d2b4f MH |
591 | * yet and true otherwise. |
592 | */ | |
593 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
594 | struct batadv_nc_path *nc_path, | |
595 | struct batadv_nc_packet *nc_packet) | |
596 | { | |
597 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
598 | bool res = false; | |
599 | ||
2c72d655 SE |
600 | lockdep_assert_held(&nc_path->packet_list_lock); |
601 | ||
612d2b4f MH |
602 | /* Packets are added to tail, so the remaining packets did not time |
603 | * out and we can stop processing the current queue | |
604 | */ | |
605 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
606 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
607 | goto out; | |
608 | ||
609 | /* purge nc packet */ | |
610 | list_del(&nc_packet->list); | |
bd687fe4 | 611 | batadv_nc_packet_free(nc_packet, true); |
612d2b4f MH |
612 | |
613 | res = true; | |
614 | ||
615 | out: | |
616 | return res; | |
617 | } | |
618 | ||
95332477 | 619 | /** |
7e9a8c2c | 620 | * batadv_nc_fwd_flush() - Checks the timestamp of the given nc packet. |
95332477 MH |
621 | * @bat_priv: the bat priv with all the soft interface information |
622 | * @nc_path: the nc path the packet belongs to | |
623 | * @nc_packet: the nc packet to be checked | |
624 | * | |
625 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
626 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
627 | * queue. Has to be called with the appropriate locks. | |
628 | * | |
62fe710f | 629 | * Return: false as soon as the entry in the fifo queue has not been timed out |
95332477 MH |
630 | * yet and true otherwise. |
631 | */ | |
632 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
633 | struct batadv_nc_path *nc_path, | |
634 | struct batadv_nc_packet *nc_packet) | |
635 | { | |
636 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
637 | ||
2c72d655 SE |
638 | lockdep_assert_held(&nc_path->packet_list_lock); |
639 | ||
95332477 MH |
640 | /* Packets are added to tail, so the remaining packets did not time |
641 | * out and we can stop processing the current queue | |
642 | */ | |
643 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
644 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
645 | return false; | |
646 | ||
647 | /* Send packet */ | |
648 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
649 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
650 | nc_packet->skb->len + ETH_HLEN); | |
651 | list_del(&nc_packet->list); | |
652 | batadv_nc_send_packet(nc_packet); | |
653 | ||
654 | return true; | |
655 | } | |
656 | ||
657 | /** | |
7e9a8c2c SE |
658 | * batadv_nc_process_nc_paths() - traverse given nc packet pool and free timed |
659 | * out nc packets | |
95332477 MH |
660 | * @bat_priv: the bat priv with all the soft interface information |
661 | * @hash: to be processed hash table | |
662 | * @process_fn: Function called to process given nc packet. Should return true | |
663 | * to encourage this function to proceed with the next packet. | |
664 | * Otherwise the rest of the current queue is skipped. | |
665 | */ | |
666 | static void | |
667 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
668 | struct batadv_hashtable *hash, | |
669 | bool (*process_fn)(struct batadv_priv *, | |
670 | struct batadv_nc_path *, | |
671 | struct batadv_nc_packet *)) | |
672 | { | |
673 | struct hlist_head *head; | |
674 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
675 | struct batadv_nc_path *nc_path; | |
676 | bool ret; | |
677 | int i; | |
678 | ||
679 | if (!hash) | |
680 | return; | |
681 | ||
682 | /* Loop hash table bins */ | |
683 | for (i = 0; i < hash->size; i++) { | |
684 | head = &hash->table[i]; | |
685 | ||
686 | /* Loop coding paths */ | |
687 | rcu_read_lock(); | |
688 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
689 | /* Loop packets */ | |
690 | spin_lock_bh(&nc_path->packet_list_lock); | |
691 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
692 | &nc_path->packet_list, list) { | |
693 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
694 | if (!ret) | |
695 | break; | |
696 | } | |
697 | spin_unlock_bh(&nc_path->packet_list_lock); | |
698 | } | |
699 | rcu_read_unlock(); | |
700 | } | |
701 | } | |
702 | ||
d353d8d4 | 703 | /** |
bccb48c8 | 704 | * batadv_nc_worker() - periodic task for housekeeping related to network |
7e9a8c2c | 705 | * coding |
d353d8d4 MH |
706 | * @work: kernel work struct |
707 | */ | |
708 | static void batadv_nc_worker(struct work_struct *work) | |
709 | { | |
710 | struct delayed_work *delayed_work; | |
711 | struct batadv_priv_nc *priv_nc; | |
712 | struct batadv_priv *bat_priv; | |
95332477 | 713 | unsigned long timeout; |
d353d8d4 | 714 | |
4ba4bc0f | 715 | delayed_work = to_delayed_work(work); |
d353d8d4 MH |
716 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); |
717 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
718 | ||
d56b1705 | 719 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
720 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
721 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
722 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
723 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
724 | |
725 | timeout = bat_priv->nc.max_fwd_delay; | |
726 | ||
727 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
728 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
729 | batadv_nc_fwd_flush); | |
730 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
731 | } | |
d56b1705 | 732 | |
612d2b4f MH |
733 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
734 | bat_priv->nc.max_buffer_time)) { | |
735 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
736 | batadv_nc_sniffed_purge); | |
737 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
738 | } | |
739 | ||
d353d8d4 MH |
740 | /* Schedule a new check */ |
741 | batadv_nc_start_timer(bat_priv); | |
742 | } | |
743 | ||
d56b1705 | 744 | /** |
7e9a8c2c SE |
745 | * batadv_can_nc_with_orig() - checks whether the given orig node is suitable |
746 | * for coding or not | |
d56b1705 MH |
747 | * @bat_priv: the bat priv with all the soft interface information |
748 | * @orig_node: neighboring orig node which may be used as nc candidate | |
749 | * @ogm_packet: incoming ogm packet also used for the checks | |
750 | * | |
62fe710f | 751 | * Return: true if: |
d56b1705 MH |
752 | * 1) The OGM must have the most recent sequence number. |
753 | * 2) The TTL must be decremented by one and only one. | |
754 | * 3) The OGM must be received from the first hop from orig_node. | |
755 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
756 | */ | |
757 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
758 | struct batadv_orig_node *orig_node, | |
759 | struct batadv_ogm_packet *ogm_packet) | |
760 | { | |
7351a482 | 761 | struct batadv_orig_ifinfo *orig_ifinfo; |
6b5e971a SE |
762 | u32 last_real_seqno; |
763 | u8 last_ttl; | |
7351a482 SW |
764 | |
765 | orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT); | |
766 | if (!orig_ifinfo) | |
d56b1705 | 767 | return false; |
7351a482 SW |
768 | |
769 | last_ttl = orig_ifinfo->last_ttl; | |
770 | last_real_seqno = orig_ifinfo->last_real_seqno; | |
35f94779 | 771 | batadv_orig_ifinfo_put(orig_ifinfo); |
7351a482 SW |
772 | |
773 | if (last_real_seqno != ntohl(ogm_packet->seqno)) | |
774 | return false; | |
775 | if (last_ttl != ogm_packet->ttl + 1) | |
d56b1705 MH |
776 | return false; |
777 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
778 | return false; | |
779 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
780 | return false; | |
781 | ||
782 | return true; | |
783 | } | |
784 | ||
785 | /** | |
7e9a8c2c | 786 | * batadv_nc_find_nc_node() - search for an existing nc node and return it |
d56b1705 MH |
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 | * @in_coding: traverse incoming or outgoing network coding list | |
791 | * | |
62fe710f | 792 | * Return: the nc_node if found, NULL otherwise. |
d56b1705 | 793 | */ |
6fc77a54 SE |
794 | static struct batadv_nc_node * |
795 | batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
796 | struct batadv_orig_node *orig_neigh_node, | |
797 | bool in_coding) | |
d56b1705 MH |
798 | { |
799 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
800 | struct list_head *list; | |
801 | ||
802 | if (in_coding) | |
803 | list = &orig_neigh_node->in_coding_list; | |
804 | else | |
805 | list = &orig_neigh_node->out_coding_list; | |
806 | ||
807 | /* Traverse list of nc_nodes to orig_node */ | |
808 | rcu_read_lock(); | |
809 | list_for_each_entry_rcu(nc_node, list, list) { | |
810 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
811 | continue; | |
812 | ||
daf99b48 | 813 | if (!kref_get_unless_zero(&nc_node->refcount)) |
d56b1705 MH |
814 | continue; |
815 | ||
816 | /* Found a match */ | |
817 | nc_node_out = nc_node; | |
818 | break; | |
819 | } | |
820 | rcu_read_unlock(); | |
821 | ||
822 | return nc_node_out; | |
823 | } | |
824 | ||
825 | /** | |
7e9a8c2c | 826 | * batadv_nc_get_nc_node() - retrieves an nc node or creates the entry if it was |
d56b1705 MH |
827 | * not found |
828 | * @bat_priv: the bat priv with all the soft interface information | |
829 | * @orig_node: orig node originating the ogm packet | |
830 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
831 | * (can be equal to orig_node) | |
832 | * @in_coding: traverse incoming or outgoing network coding list | |
833 | * | |
62fe710f | 834 | * Return: the nc_node if found or created, NULL in case of an error. |
d56b1705 | 835 | */ |
6fc77a54 SE |
836 | static struct batadv_nc_node * |
837 | batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
838 | struct batadv_orig_node *orig_node, | |
839 | struct batadv_orig_node *orig_neigh_node, | |
840 | bool in_coding) | |
d56b1705 MH |
841 | { |
842 | struct batadv_nc_node *nc_node; | |
843 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
844 | struct list_head *list; | |
845 | ||
fa122fec SE |
846 | /* Select ingoing or outgoing coding node */ |
847 | if (in_coding) { | |
848 | lock = &orig_neigh_node->in_coding_list_lock; | |
849 | list = &orig_neigh_node->in_coding_list; | |
850 | } else { | |
851 | lock = &orig_neigh_node->out_coding_list_lock; | |
852 | list = &orig_neigh_node->out_coding_list; | |
853 | } | |
854 | ||
855 | spin_lock_bh(lock); | |
856 | ||
d56b1705 MH |
857 | /* Check if nc_node is already added */ |
858 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
859 | ||
860 | /* Node found */ | |
861 | if (nc_node) | |
fa122fec | 862 | goto unlock; |
d56b1705 MH |
863 | |
864 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
865 | if (!nc_node) | |
fa122fec | 866 | goto unlock; |
d56b1705 | 867 | |
d56b1705 MH |
868 | /* Initialize nc_node */ |
869 | INIT_LIST_HEAD(&nc_node->list); | |
daf99b48 | 870 | kref_init(&nc_node->refcount); |
55db2d59 SE |
871 | ether_addr_copy(nc_node->addr, orig_node->orig); |
872 | kref_get(&orig_neigh_node->refcount); | |
873 | nc_node->orig_node = orig_neigh_node; | |
d56b1705 | 874 | |
d56b1705 MH |
875 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", |
876 | nc_node->addr, nc_node->orig_node->orig); | |
877 | ||
878 | /* Add nc_node to orig_node */ | |
da7a26af | 879 | kref_get(&nc_node->refcount); |
d56b1705 | 880 | list_add_tail_rcu(&nc_node->list, list); |
fa122fec SE |
881 | |
882 | unlock: | |
d56b1705 MH |
883 | spin_unlock_bh(lock); |
884 | ||
885 | return nc_node; | |
d56b1705 MH |
886 | } |
887 | ||
888 | /** | |
7e9a8c2c | 889 | * batadv_nc_update_nc_node() - updates stored incoming and outgoing nc node |
34473822 | 890 | * structs (best called on incoming OGMs) |
d56b1705 MH |
891 | * @bat_priv: the bat priv with all the soft interface information |
892 | * @orig_node: orig node originating the ogm packet | |
893 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
894 | * (can be equal to orig_node) | |
895 | * @ogm_packet: incoming ogm packet | |
896 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
897 | */ | |
898 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
899 | struct batadv_orig_node *orig_node, | |
900 | struct batadv_orig_node *orig_neigh_node, | |
901 | struct batadv_ogm_packet *ogm_packet, | |
902 | int is_single_hop_neigh) | |
903 | { | |
4f248cff SE |
904 | struct batadv_nc_node *in_nc_node = NULL; |
905 | struct batadv_nc_node *out_nc_node = NULL; | |
d56b1705 MH |
906 | |
907 | /* Check if network coding is enabled */ | |
908 | if (!atomic_read(&bat_priv->network_coding)) | |
909 | goto out; | |
910 | ||
3f4841ff | 911 | /* check if orig node is network coding enabled */ |
4635469f | 912 | if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities)) |
3f4841ff ML |
913 | goto out; |
914 | ||
d56b1705 MH |
915 | /* accept ogms from 'good' neighbors and single hop neighbors */ |
916 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
917 | !is_single_hop_neigh) | |
918 | goto out; | |
919 | ||
920 | /* Add orig_node as in_nc_node on hop */ | |
921 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
922 | orig_neigh_node, true); | |
923 | if (!in_nc_node) | |
924 | goto out; | |
925 | ||
926 | in_nc_node->last_seen = jiffies; | |
927 | ||
928 | /* Add hop as out_nc_node on orig_node */ | |
929 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
930 | orig_node, false); | |
931 | if (!out_nc_node) | |
932 | goto out; | |
933 | ||
934 | out_nc_node->last_seen = jiffies; | |
935 | ||
936 | out: | |
79a0bffb SE |
937 | batadv_nc_node_put(in_nc_node); |
938 | batadv_nc_node_put(out_nc_node); | |
d56b1705 MH |
939 | } |
940 | ||
95332477 | 941 | /** |
7e9a8c2c | 942 | * batadv_nc_get_path() - get existing nc_path or allocate a new one |
95332477 MH |
943 | * @bat_priv: the bat priv with all the soft interface information |
944 | * @hash: hash table containing the nc path | |
945 | * @src: ethernet source address - first half of the nc path search key | |
946 | * @dst: ethernet destination address - second half of the nc path search key | |
947 | * | |
62fe710f | 948 | * Return: pointer to nc_path if the path was found or created, returns NULL |
95332477 MH |
949 | * on error. |
950 | */ | |
951 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
952 | struct batadv_hashtable *hash, | |
6b5e971a SE |
953 | u8 *src, |
954 | u8 *dst) | |
95332477 MH |
955 | { |
956 | int hash_added; | |
957 | struct batadv_nc_path *nc_path, nc_path_key; | |
958 | ||
959 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
960 | ||
961 | /* Search for existing nc_path */ | |
962 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
963 | ||
964 | if (nc_path) { | |
965 | /* Set timestamp to delay removal of nc_path */ | |
966 | nc_path->last_valid = jiffies; | |
967 | return nc_path; | |
968 | } | |
969 | ||
970 | /* No existing nc_path was found; create a new */ | |
971 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
972 | ||
973 | if (!nc_path) | |
974 | return NULL; | |
975 | ||
976 | /* Initialize nc_path */ | |
977 | INIT_LIST_HEAD(&nc_path->packet_list); | |
978 | spin_lock_init(&nc_path->packet_list_lock); | |
727e0cd5 | 979 | kref_init(&nc_path->refcount); |
95332477 | 980 | nc_path->last_valid = jiffies; |
8fdd0153 AQ |
981 | ether_addr_copy(nc_path->next_hop, dst); |
982 | ether_addr_copy(nc_path->prev_hop, src); | |
95332477 MH |
983 | |
984 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
985 | nc_path->prev_hop, | |
986 | nc_path->next_hop); | |
987 | ||
988 | /* Add nc_path to hash table */ | |
f489eab5 | 989 | kref_get(&nc_path->refcount); |
95332477 MH |
990 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, |
991 | batadv_nc_hash_choose, &nc_path_key, | |
992 | &nc_path->hash_entry); | |
993 | ||
994 | if (hash_added < 0) { | |
995 | kfree(nc_path); | |
996 | return NULL; | |
997 | } | |
998 | ||
999 | return nc_path; | |
1000 | } | |
1001 | ||
3c12de9a | 1002 | /** |
7e9a8c2c | 1003 | * batadv_nc_random_weight_tq() - scale the receivers TQ-value to avoid unfair |
3c12de9a MH |
1004 | * selection of a receiver with slightly lower TQ than the other |
1005 | * @tq: to be weighted tq value | |
672e7978 SE |
1006 | * |
1007 | * Return: scaled tq value | |
3c12de9a | 1008 | */ |
6b5e971a | 1009 | static u8 batadv_nc_random_weight_tq(u8 tq) |
3c12de9a | 1010 | { |
3c12de9a | 1011 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ |
fd0c42c4 | 1012 | u8 rand_tq = prandom_u32_max(BATADV_TQ_MAX_VALUE + 1 - tq); |
3c12de9a MH |
1013 | |
1014 | /* convert to (randomized) estimated tq again */ | |
1015 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
1016 | } | |
1017 | ||
1018 | /** | |
7e9a8c2c | 1019 | * batadv_nc_memxor() - XOR destination with source |
3c12de9a MH |
1020 | * @dst: byte array to XOR into |
1021 | * @src: byte array to XOR from | |
1022 | * @len: length of destination array | |
1023 | */ | |
1024 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
1025 | { | |
1026 | unsigned int i; | |
1027 | ||
1028 | for (i = 0; i < len; ++i) | |
1029 | dst[i] ^= src[i]; | |
1030 | } | |
1031 | ||
1032 | /** | |
7e9a8c2c | 1033 | * batadv_nc_code_packets() - code a received unicast_packet with an nc packet |
3c12de9a MH |
1034 | * into a coded_packet and send it |
1035 | * @bat_priv: the bat priv with all the soft interface information | |
1036 | * @skb: data skb to forward | |
1037 | * @ethhdr: pointer to the ethernet header inside the skb | |
1038 | * @nc_packet: structure containing the packet to the skb can be coded with | |
1039 | * @neigh_node: next hop to forward packet to | |
1040 | * | |
62fe710f | 1041 | * Return: true if both packets are consumed, false otherwise. |
3c12de9a MH |
1042 | */ |
1043 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
1044 | struct sk_buff *skb, | |
1045 | struct ethhdr *ethhdr, | |
1046 | struct batadv_nc_packet *nc_packet, | |
1047 | struct batadv_neigh_node *neigh_node) | |
1048 | { | |
6b5e971a | 1049 | u8 tq_weighted_neigh, tq_weighted_coding, tq_tmp; |
3c12de9a MH |
1050 | struct sk_buff *skb_dest, *skb_src; |
1051 | struct batadv_unicast_packet *packet1; | |
1052 | struct batadv_unicast_packet *packet2; | |
1053 | struct batadv_coded_packet *coded_packet; | |
95d39278 AQ |
1054 | struct batadv_neigh_node *neigh_tmp, *router_neigh, *first_dest; |
1055 | struct batadv_neigh_node *router_coding = NULL, *second_dest; | |
89652331 SW |
1056 | struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL; |
1057 | struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL; | |
95d39278 | 1058 | u8 *first_source, *second_source; |
3c12de9a MH |
1059 | __be32 packet_id1, packet_id2; |
1060 | size_t count; | |
1061 | bool res = false; | |
1062 | int coding_len; | |
1063 | int unicast_size = sizeof(*packet1); | |
1064 | int coded_size = sizeof(*coded_packet); | |
1065 | int header_add = coded_size - unicast_size; | |
1066 | ||
7351a482 SW |
1067 | /* TODO: do we need to consider the outgoing interface for |
1068 | * coded packets? | |
1069 | */ | |
1070 | router_neigh = batadv_orig_router_get(neigh_node->orig_node, | |
1071 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1072 | if (!router_neigh) |
1073 | goto out; | |
1074 | ||
89652331 SW |
1075 | router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh, |
1076 | BATADV_IF_DEFAULT); | |
1077 | if (!router_neigh_ifinfo) | |
1078 | goto out; | |
1079 | ||
3c12de9a | 1080 | neigh_tmp = nc_packet->neigh_node; |
7351a482 SW |
1081 | router_coding = batadv_orig_router_get(neigh_tmp->orig_node, |
1082 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1083 | if (!router_coding) |
1084 | goto out; | |
1085 | ||
89652331 SW |
1086 | router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding, |
1087 | BATADV_IF_DEFAULT); | |
1088 | if (!router_coding_ifinfo) | |
1089 | goto out; | |
1090 | ||
1091 | tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg; | |
1092 | tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp); | |
1093 | tq_tmp = router_coding_ifinfo->bat_iv.tq_avg; | |
1094 | tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp); | |
3c12de9a MH |
1095 | |
1096 | /* Select one destination for the MAC-header dst-field based on | |
1097 | * weighted TQ-values. | |
1098 | */ | |
1099 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
1100 | /* Destination from nc_packet is selected for MAC-header */ | |
95d39278 | 1101 | first_dest = nc_packet->neigh_node; |
3c12de9a | 1102 | first_source = nc_packet->nc_path->prev_hop; |
95d39278 | 1103 | second_dest = neigh_node; |
3c12de9a MH |
1104 | second_source = ethhdr->h_source; |
1105 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1106 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
1107 | packet_id1 = nc_packet->packet_id; | |
1108 | packet_id2 = batadv_skb_crc32(skb, | |
1109 | skb->data + sizeof(*packet2)); | |
1110 | } else { | |
1111 | /* Destination for skb is selected for MAC-header */ | |
95d39278 | 1112 | first_dest = neigh_node; |
3c12de9a | 1113 | first_source = ethhdr->h_source; |
95d39278 | 1114 | second_dest = nc_packet->neigh_node; |
3c12de9a MH |
1115 | second_source = nc_packet->nc_path->prev_hop; |
1116 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
1117 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1118 | packet_id1 = batadv_skb_crc32(skb, | |
1119 | skb->data + sizeof(*packet1)); | |
1120 | packet_id2 = nc_packet->packet_id; | |
1121 | } | |
1122 | ||
1123 | /* Instead of zero padding the smallest data buffer, we | |
1124 | * code into the largest. | |
1125 | */ | |
1126 | if (skb->len <= nc_packet->skb->len) { | |
1127 | skb_dest = nc_packet->skb; | |
1128 | skb_src = skb; | |
1129 | } else { | |
1130 | skb_dest = skb; | |
1131 | skb_src = nc_packet->skb; | |
1132 | } | |
1133 | ||
1134 | /* coding_len is used when decoding the packet shorter packet */ | |
1135 | coding_len = skb_src->len - unicast_size; | |
1136 | ||
1137 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1138 | goto out; | |
1139 | ||
1140 | skb_push(skb_dest, header_add); | |
1141 | ||
1142 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1143 | skb_reset_mac_header(skb_dest); | |
1144 | ||
a40d9b07 SW |
1145 | coded_packet->packet_type = BATADV_CODED; |
1146 | coded_packet->version = BATADV_COMPAT_VERSION; | |
1147 | coded_packet->ttl = packet1->ttl; | |
3c12de9a MH |
1148 | |
1149 | /* Info about first unicast packet */ | |
8fdd0153 AQ |
1150 | ether_addr_copy(coded_packet->first_source, first_source); |
1151 | ether_addr_copy(coded_packet->first_orig_dest, packet1->dest); | |
3c12de9a MH |
1152 | coded_packet->first_crc = packet_id1; |
1153 | coded_packet->first_ttvn = packet1->ttvn; | |
1154 | ||
1155 | /* Info about second unicast packet */ | |
95d39278 | 1156 | ether_addr_copy(coded_packet->second_dest, second_dest->addr); |
8fdd0153 AQ |
1157 | ether_addr_copy(coded_packet->second_source, second_source); |
1158 | ether_addr_copy(coded_packet->second_orig_dest, packet2->dest); | |
3c12de9a | 1159 | coded_packet->second_crc = packet_id2; |
a40d9b07 | 1160 | coded_packet->second_ttl = packet2->ttl; |
3c12de9a MH |
1161 | coded_packet->second_ttvn = packet2->ttvn; |
1162 | coded_packet->coded_len = htons(coding_len); | |
1163 | ||
1164 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1165 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1166 | skb_src->data + unicast_size, coding_len); | |
1167 | ||
1168 | /* Update counters accordingly */ | |
1169 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1170 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1171 | /* Both packets are recoded */ | |
1172 | count = skb_src->len + ETH_HLEN; | |
1173 | count += skb_dest->len + ETH_HLEN; | |
1174 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1175 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1176 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1177 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1178 | /* Both packets are newly coded */ | |
1179 | count = skb_src->len + ETH_HLEN; | |
1180 | count += skb_dest->len + ETH_HLEN; | |
1181 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1182 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1183 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1184 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1185 | /* skb_src recoded and skb_dest is newly coded */ | |
1186 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1187 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1188 | skb_src->len + ETH_HLEN); | |
1189 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1190 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1191 | skb_dest->len + ETH_HLEN); | |
1192 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1193 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1194 | /* skb_src is newly coded and skb_dest is recoded */ | |
1195 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1196 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1197 | skb_src->len + ETH_HLEN); | |
1198 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1199 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1200 | skb_dest->len + ETH_HLEN); | |
1201 | } | |
1202 | ||
1203 | /* skb_src is now coded into skb_dest, so free it */ | |
bd687fe4 | 1204 | consume_skb(skb_src); |
3c12de9a MH |
1205 | |
1206 | /* avoid duplicate free of skb from nc_packet */ | |
1207 | nc_packet->skb = NULL; | |
bd687fe4 | 1208 | batadv_nc_packet_free(nc_packet, false); |
3c12de9a MH |
1209 | |
1210 | /* Send the coded packet and return true */ | |
95d39278 | 1211 | batadv_send_unicast_skb(skb_dest, first_dest); |
3c12de9a MH |
1212 | res = true; |
1213 | out: | |
79a0bffb SE |
1214 | batadv_neigh_node_put(router_neigh); |
1215 | batadv_neigh_node_put(router_coding); | |
1216 | batadv_neigh_ifinfo_put(router_neigh_ifinfo); | |
1217 | batadv_neigh_ifinfo_put(router_coding_ifinfo); | |
3c12de9a MH |
1218 | return res; |
1219 | } | |
1220 | ||
1221 | /** | |
7e9a8c2c | 1222 | * batadv_nc_skb_coding_possible() - true if a decoded skb is available at dst. |
3c12de9a MH |
1223 | * @skb: data skb to forward |
1224 | * @dst: destination mac address of the other skb to code with | |
1225 | * @src: source mac address of skb | |
1226 | * | |
1227 | * Whenever we network code a packet we have to check whether we received it in | |
1228 | * a network coded form. If so, we may not be able to use it for coding because | |
1229 | * some neighbors may also have received (overheard) the packet in the network | |
1230 | * coded form without being able to decode it. It is hard to know which of the | |
1231 | * neighboring nodes was able to decode the packet, therefore we can only | |
1232 | * re-code the packet if the source of the previous encoded packet is involved. | |
1233 | * Since the source encoded the packet we can be certain it has all necessary | |
1234 | * decode information. | |
1235 | * | |
62fe710f | 1236 | * Return: true if coding of a decoded packet is allowed. |
3c12de9a | 1237 | */ |
6b5e971a | 1238 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, u8 *dst, u8 *src) |
3c12de9a MH |
1239 | { |
1240 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1241 | return false; | |
24820df1 | 1242 | return true; |
3c12de9a MH |
1243 | } |
1244 | ||
1245 | /** | |
7e9a8c2c | 1246 | * batadv_nc_path_search() - Find the coding path matching in_nc_node and |
3c12de9a MH |
1247 | * out_nc_node to retrieve a buffered packet that can be used for coding. |
1248 | * @bat_priv: the bat priv with all the soft interface information | |
1249 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1250 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1251 | * @skb: data skb to forward | |
1252 | * @eth_dst: next hop mac address of skb | |
1253 | * | |
62fe710f | 1254 | * Return: true if coding of a decoded skb is allowed. |
3c12de9a MH |
1255 | */ |
1256 | static struct batadv_nc_packet * | |
1257 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1258 | struct batadv_nc_node *in_nc_node, | |
1259 | struct batadv_nc_node *out_nc_node, | |
1260 | struct sk_buff *skb, | |
6b5e971a | 1261 | u8 *eth_dst) |
3c12de9a MH |
1262 | { |
1263 | struct batadv_nc_path *nc_path, nc_path_key; | |
1264 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1265 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1266 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1267 | int idx; | |
1268 | ||
1269 | if (!hash) | |
1270 | return NULL; | |
1271 | ||
1272 | /* Create almost path key */ | |
1273 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1274 | out_nc_node->addr); | |
1275 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1276 | ||
1277 | /* Check for coding opportunities in this nc_path */ | |
1278 | rcu_read_lock(); | |
1279 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1280 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1281 | continue; | |
1282 | ||
1283 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1284 | continue; | |
1285 | ||
1286 | spin_lock_bh(&nc_path->packet_list_lock); | |
1287 | if (list_empty(&nc_path->packet_list)) { | |
1288 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1289 | continue; | |
1290 | } | |
1291 | ||
1292 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1293 | &nc_path->packet_list, list) { | |
1294 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1295 | eth_dst, | |
1296 | in_nc_node->addr)) | |
1297 | continue; | |
1298 | ||
1299 | /* Coding opportunity is found! */ | |
1300 | list_del(&nc_packet->list); | |
1301 | nc_packet_out = nc_packet; | |
1302 | break; | |
1303 | } | |
1304 | ||
1305 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1306 | break; | |
1307 | } | |
1308 | rcu_read_unlock(); | |
1309 | ||
1310 | return nc_packet_out; | |
1311 | } | |
1312 | ||
1313 | /** | |
bccb48c8 | 1314 | * batadv_nc_skb_src_search() - Loops through the list of neighboring nodes of |
7e9a8c2c | 1315 | * the skb's sender (may be equal to the originator). |
3c12de9a MH |
1316 | * @bat_priv: the bat priv with all the soft interface information |
1317 | * @skb: data skb to forward | |
1318 | * @eth_dst: next hop mac address of skb | |
1319 | * @eth_src: source mac address of skb | |
1320 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1321 | * | |
62fe710f | 1322 | * Return: an nc packet if a suitable coding packet was found, NULL otherwise. |
3c12de9a MH |
1323 | */ |
1324 | static struct batadv_nc_packet * | |
1325 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1326 | struct sk_buff *skb, | |
6b5e971a SE |
1327 | u8 *eth_dst, |
1328 | u8 *eth_src, | |
3c12de9a MH |
1329 | struct batadv_nc_node *in_nc_node) |
1330 | { | |
1331 | struct batadv_orig_node *orig_node; | |
1332 | struct batadv_nc_node *out_nc_node; | |
1333 | struct batadv_nc_packet *nc_packet = NULL; | |
1334 | ||
1335 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1336 | if (!orig_node) | |
1337 | return NULL; | |
1338 | ||
1339 | rcu_read_lock(); | |
1340 | list_for_each_entry_rcu(out_nc_node, | |
1341 | &orig_node->out_coding_list, list) { | |
1342 | /* Check if the skb is decoded and if recoding is possible */ | |
1343 | if (!batadv_nc_skb_coding_possible(skb, | |
1344 | out_nc_node->addr, eth_src)) | |
1345 | continue; | |
1346 | ||
1347 | /* Search for an opportunity in this nc_path */ | |
1348 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1349 | out_nc_node, skb, eth_dst); | |
1350 | if (nc_packet) | |
1351 | break; | |
1352 | } | |
1353 | rcu_read_unlock(); | |
1354 | ||
5d967310 | 1355 | batadv_orig_node_put(orig_node); |
3c12de9a MH |
1356 | return nc_packet; |
1357 | } | |
1358 | ||
612d2b4f | 1359 | /** |
7e9a8c2c | 1360 | * batadv_nc_skb_store_before_coding() - set the ethernet src and dst of the |
612d2b4f MH |
1361 | * unicast skb before it is stored for use in later decoding |
1362 | * @bat_priv: the bat priv with all the soft interface information | |
1363 | * @skb: data skb to store | |
1364 | * @eth_dst_new: new destination mac address of skb | |
1365 | */ | |
1366 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1367 | struct sk_buff *skb, | |
6b5e971a | 1368 | u8 *eth_dst_new) |
612d2b4f MH |
1369 | { |
1370 | struct ethhdr *ethhdr; | |
1371 | ||
1372 | /* Copy skb header to change the mac header */ | |
bad93e9d | 1373 | skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
612d2b4f MH |
1374 | if (!skb) |
1375 | return; | |
1376 | ||
1377 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1378 | ethhdr = eth_hdr(skb); |
8fdd0153 AQ |
1379 | ether_addr_copy(ethhdr->h_source, ethhdr->h_dest); |
1380 | ether_addr_copy(ethhdr->h_dest, eth_dst_new); | |
612d2b4f MH |
1381 | |
1382 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1383 | skb_push(skb, ETH_HLEN); | |
1384 | ||
1385 | /* Add the packet to the decoding packet pool */ | |
1386 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1387 | ||
1388 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1389 | * our ref | |
1390 | */ | |
bd687fe4 | 1391 | consume_skb(skb); |
612d2b4f MH |
1392 | } |
1393 | ||
3c12de9a | 1394 | /** |
7e9a8c2c | 1395 | * batadv_nc_skb_dst_search() - Loops through list of neighboring nodes to dst. |
3c12de9a MH |
1396 | * @skb: data skb to forward |
1397 | * @neigh_node: next hop to forward packet to | |
1398 | * @ethhdr: pointer to the ethernet header inside the skb | |
1399 | * | |
bccb48c8 SE |
1400 | * Loops through the list of neighboring nodes the next hop has a good |
1401 | * connection to (receives OGMs with a sufficient quality). We need to find a | |
1402 | * neighbor of our next hop that potentially sent a packet which our next hop | |
1403 | * also received (overheard) and has stored for later decoding. | |
3c12de9a | 1404 | * |
62fe710f | 1405 | * Return: true if the skb was consumed (encoded packet sent) or false otherwise |
3c12de9a MH |
1406 | */ |
1407 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1408 | struct batadv_neigh_node *neigh_node, | |
1409 | struct ethhdr *ethhdr) | |
1410 | { | |
1411 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1412 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1413 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1414 | struct batadv_nc_node *nc_node; | |
1415 | struct batadv_nc_packet *nc_packet = NULL; | |
1416 | ||
1417 | rcu_read_lock(); | |
1418 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1419 | /* Search for coding opportunity with this in_nc_node */ | |
1420 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1421 | neigh_node->addr, | |
1422 | ethhdr->h_source, nc_node); | |
1423 | ||
1424 | /* Opportunity was found, so stop searching */ | |
1425 | if (nc_packet) | |
1426 | break; | |
1427 | } | |
1428 | rcu_read_unlock(); | |
1429 | ||
1430 | if (!nc_packet) | |
1431 | return false; | |
1432 | ||
612d2b4f MH |
1433 | /* Save packets for later decoding */ |
1434 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1435 | neigh_node->addr); | |
1436 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1437 | nc_packet->neigh_node->addr); | |
1438 | ||
3c12de9a MH |
1439 | /* Code and send packets */ |
1440 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1441 | neigh_node)) | |
1442 | return true; | |
1443 | ||
1444 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1445 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1446 | * by the calling function. | |
1447 | */ | |
1448 | batadv_nc_send_packet(nc_packet); | |
1449 | return false; | |
1450 | } | |
1451 | ||
95332477 | 1452 | /** |
7e9a8c2c | 1453 | * batadv_nc_skb_add_to_path() - buffer skb for later encoding / decoding |
95332477 MH |
1454 | * @skb: skb to add to path |
1455 | * @nc_path: path to add skb to | |
1456 | * @neigh_node: next hop to forward packet to | |
1457 | * @packet_id: checksum to identify packet | |
1458 | * | |
62fe710f | 1459 | * Return: true if the packet was buffered or false in case of an error. |
95332477 MH |
1460 | */ |
1461 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1462 | struct batadv_nc_path *nc_path, | |
1463 | struct batadv_neigh_node *neigh_node, | |
1464 | __be32 packet_id) | |
1465 | { | |
1466 | struct batadv_nc_packet *nc_packet; | |
1467 | ||
1468 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1469 | if (!nc_packet) | |
1470 | return false; | |
1471 | ||
1472 | /* Initialize nc_packet */ | |
1473 | nc_packet->timestamp = jiffies; | |
1474 | nc_packet->packet_id = packet_id; | |
1475 | nc_packet->skb = skb; | |
1476 | nc_packet->neigh_node = neigh_node; | |
1477 | nc_packet->nc_path = nc_path; | |
1478 | ||
1479 | /* Add coding packet to list */ | |
1480 | spin_lock_bh(&nc_path->packet_list_lock); | |
1481 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1482 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1483 | ||
1484 | return true; | |
1485 | } | |
1486 | ||
1487 | /** | |
7e9a8c2c | 1488 | * batadv_nc_skb_forward() - try to code a packet or add it to the coding packet |
95332477 MH |
1489 | * buffer |
1490 | * @skb: data skb to forward | |
1491 | * @neigh_node: next hop to forward packet to | |
95332477 | 1492 | * |
62fe710f | 1493 | * Return: true if the skb was consumed (encoded packet sent) or false otherwise |
95332477 MH |
1494 | */ |
1495 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
e91ecfc6 | 1496 | struct batadv_neigh_node *neigh_node) |
95332477 MH |
1497 | { |
1498 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1499 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1500 | struct batadv_unicast_packet *packet; | |
1501 | struct batadv_nc_path *nc_path; | |
e91ecfc6 | 1502 | struct ethhdr *ethhdr = eth_hdr(skb); |
95332477 MH |
1503 | __be32 packet_id; |
1504 | u8 *payload; | |
1505 | ||
1506 | /* Check if network coding is enabled */ | |
1507 | if (!atomic_read(&bat_priv->network_coding)) | |
1508 | goto out; | |
1509 | ||
1510 | /* We only handle unicast packets */ | |
1511 | payload = skb_network_header(skb); | |
1512 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1513 | if (packet->packet_type != BATADV_UNICAST) |
95332477 MH |
1514 | goto out; |
1515 | ||
3c12de9a MH |
1516 | /* Try to find a coding opportunity and send the skb if one is found */ |
1517 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1518 | return true; | |
1519 | ||
95332477 MH |
1520 | /* Find or create a nc_path for this src-dst pair */ |
1521 | nc_path = batadv_nc_get_path(bat_priv, | |
1522 | bat_priv->nc.coding_hash, | |
1523 | ethhdr->h_source, | |
1524 | neigh_node->addr); | |
1525 | ||
1526 | if (!nc_path) | |
1527 | goto out; | |
1528 | ||
1529 | /* Add skb to nc_path */ | |
1530 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1531 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1532 | goto free_nc_path; | |
1533 | ||
1534 | /* Packet is consumed */ | |
1535 | return true; | |
1536 | ||
1537 | free_nc_path: | |
5fff2825 | 1538 | batadv_nc_path_put(nc_path); |
95332477 MH |
1539 | out: |
1540 | /* Packet is not consumed */ | |
1541 | return false; | |
1542 | } | |
1543 | ||
612d2b4f | 1544 | /** |
7e9a8c2c SE |
1545 | * batadv_nc_skb_store_for_decoding() - save a clone of the skb which can be |
1546 | * used when decoding coded packets | |
612d2b4f MH |
1547 | * @bat_priv: the bat priv with all the soft interface information |
1548 | * @skb: data skb to store | |
1549 | */ | |
1550 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1551 | struct sk_buff *skb) | |
1552 | { | |
1553 | struct batadv_unicast_packet *packet; | |
1554 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1555 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1556 | __be32 packet_id; |
1557 | u8 *payload; | |
1558 | ||
1559 | /* Check if network coding is enabled */ | |
1560 | if (!atomic_read(&bat_priv->network_coding)) | |
1561 | goto out; | |
1562 | ||
1563 | /* Check for supported packet type */ | |
1564 | payload = skb_network_header(skb); | |
1565 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1566 | if (packet->packet_type != BATADV_UNICAST) |
612d2b4f MH |
1567 | goto out; |
1568 | ||
1569 | /* Find existing nc_path or create a new */ | |
1570 | nc_path = batadv_nc_get_path(bat_priv, | |
1571 | bat_priv->nc.decoding_hash, | |
1572 | ethhdr->h_source, | |
1573 | ethhdr->h_dest); | |
1574 | ||
1575 | if (!nc_path) | |
1576 | goto out; | |
1577 | ||
1578 | /* Clone skb and adjust skb->data to point at batman header */ | |
1579 | skb = skb_clone(skb, GFP_ATOMIC); | |
1580 | if (unlikely(!skb)) | |
1581 | goto free_nc_path; | |
1582 | ||
1583 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1584 | goto free_skb; | |
1585 | ||
1586 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1587 | goto free_skb; | |
1588 | ||
1589 | /* Add skb to nc_path */ | |
1590 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1591 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1592 | goto free_skb; | |
1593 | ||
1594 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1595 | return; | |
1596 | ||
1597 | free_skb: | |
1598 | kfree_skb(skb); | |
1599 | free_nc_path: | |
5fff2825 | 1600 | batadv_nc_path_put(nc_path); |
612d2b4f MH |
1601 | out: |
1602 | return; | |
1603 | } | |
1604 | ||
1605 | /** | |
7e9a8c2c | 1606 | * batadv_nc_skb_store_sniffed_unicast() - check if a received unicast packet |
612d2b4f MH |
1607 | * should be saved in the decoding buffer and, if so, store it there |
1608 | * @bat_priv: the bat priv with all the soft interface information | |
1609 | * @skb: unicast skb to store | |
1610 | */ | |
1611 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1612 | struct sk_buff *skb) | |
1613 | { | |
7ed4be95 | 1614 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1615 | |
6e0895c2 | 1616 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1617 | return; |
1618 | ||
1619 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1620 | skb_push(skb, ETH_HLEN); | |
1621 | ||
1622 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1623 | } | |
1624 | ||
2df5278b | 1625 | /** |
7e9a8c2c | 1626 | * batadv_nc_skb_decode_packet() - decode given skb using the decode data stored |
2df5278b | 1627 | * in nc_packet |
6e0895c2 | 1628 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1629 | * @skb: unicast skb to decode |
1630 | * @nc_packet: decode data needed to decode the skb | |
1631 | * | |
62fe710f | 1632 | * Return: pointer to decoded unicast packet if the packet was decoded or NULL |
2df5278b MH |
1633 | * in case of an error. |
1634 | */ | |
1635 | static struct batadv_unicast_packet * | |
6e0895c2 | 1636 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1637 | struct batadv_nc_packet *nc_packet) |
1638 | { | |
1639 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1640 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1641 | struct batadv_unicast_packet *unicast_packet; | |
1642 | struct batadv_coded_packet coded_packet_tmp; | |
1643 | struct ethhdr *ethhdr, ethhdr_tmp; | |
6b5e971a | 1644 | u8 *orig_dest, ttl, ttvn; |
2df5278b | 1645 | unsigned int coding_len; |
7da19971 | 1646 | int err; |
2df5278b MH |
1647 | |
1648 | /* Save headers temporarily */ | |
1649 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1650 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1651 | ||
1652 | if (skb_cow(skb, 0) < 0) | |
1653 | return NULL; | |
1654 | ||
1655 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1656 | return NULL; | |
1657 | ||
1658 | /* Data points to batman header, so set mac header 14 bytes before | |
1659 | * and network to data | |
1660 | */ | |
1661 | skb_set_mac_header(skb, -ETH_HLEN); | |
1662 | skb_reset_network_header(skb); | |
1663 | ||
1664 | /* Reconstruct original mac header */ | |
7ed4be95 | 1665 | ethhdr = eth_hdr(skb); |
abae9479 | 1666 | *ethhdr = ethhdr_tmp; |
2df5278b MH |
1667 | |
1668 | /* Select the correct unicast header information based on the location | |
1669 | * of our mac address in the coded_packet header | |
1670 | */ | |
6e0895c2 | 1671 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1672 | /* If we are the second destination the packet was overheard, |
1673 | * so the Ethernet address must be copied to h_dest and | |
1674 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1675 | */ | |
8fdd0153 | 1676 | ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest); |
2df5278b MH |
1677 | skb->pkt_type = PACKET_HOST; |
1678 | ||
1679 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1680 | ttl = coded_packet_tmp.second_ttl; | |
1681 | ttvn = coded_packet_tmp.second_ttvn; | |
1682 | } else { | |
1683 | orig_dest = coded_packet_tmp.first_orig_dest; | |
a40d9b07 | 1684 | ttl = coded_packet_tmp.ttl; |
2df5278b MH |
1685 | ttvn = coded_packet_tmp.first_ttvn; |
1686 | } | |
1687 | ||
1688 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1689 | ||
1690 | if (coding_len > skb->len) | |
1691 | return NULL; | |
1692 | ||
1693 | /* Here the magic is reversed: | |
1694 | * extract the missing packet from the received coded packet | |
1695 | */ | |
1696 | batadv_nc_memxor(skb->data + h_size, | |
1697 | nc_packet->skb->data + h_size, | |
1698 | coding_len); | |
1699 | ||
1700 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1701 | if (nc_packet->skb->len > coding_len + h_size) { |
1702 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1703 | if (err) | |
1704 | return NULL; | |
1705 | } | |
2df5278b MH |
1706 | |
1707 | /* Create decoded unicast packet */ | |
1708 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
a40d9b07 SW |
1709 | unicast_packet->packet_type = BATADV_UNICAST; |
1710 | unicast_packet->version = BATADV_COMPAT_VERSION; | |
1711 | unicast_packet->ttl = ttl; | |
8fdd0153 | 1712 | ether_addr_copy(unicast_packet->dest, orig_dest); |
2df5278b MH |
1713 | unicast_packet->ttvn = ttvn; |
1714 | ||
bd687fe4 | 1715 | batadv_nc_packet_free(nc_packet, false); |
2df5278b MH |
1716 | return unicast_packet; |
1717 | } | |
1718 | ||
1719 | /** | |
7e9a8c2c | 1720 | * batadv_nc_find_decoding_packet() - search through buffered decoding data to |
2df5278b MH |
1721 | * find the data needed to decode the coded packet |
1722 | * @bat_priv: the bat priv with all the soft interface information | |
1723 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1724 | * @coded: coded packet we try to find decode data for | |
1725 | * | |
62fe710f | 1726 | * Return: pointer to nc packet if the needed data was found or NULL otherwise. |
2df5278b MH |
1727 | */ |
1728 | static struct batadv_nc_packet * | |
1729 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1730 | struct ethhdr *ethhdr, | |
1731 | struct batadv_coded_packet *coded) | |
1732 | { | |
1733 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1734 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1735 | struct batadv_nc_path *nc_path, nc_path_key; | |
6b5e971a | 1736 | u8 *dest, *source; |
2df5278b MH |
1737 | __be32 packet_id; |
1738 | int index; | |
1739 | ||
1740 | if (!hash) | |
1741 | return NULL; | |
1742 | ||
1743 | /* Select the correct packet id based on the location of our mac-addr */ | |
1744 | dest = ethhdr->h_source; | |
6e0895c2 | 1745 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1746 | source = coded->second_source; |
1747 | packet_id = coded->second_crc; | |
1748 | } else { | |
1749 | source = coded->first_source; | |
1750 | packet_id = coded->first_crc; | |
1751 | } | |
1752 | ||
1753 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1754 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1755 | ||
1756 | /* Search for matching coding path */ | |
1757 | rcu_read_lock(); | |
1758 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1759 | /* Find matching nc_packet */ | |
1760 | spin_lock_bh(&nc_path->packet_list_lock); | |
1761 | list_for_each_entry(tmp_nc_packet, | |
1762 | &nc_path->packet_list, list) { | |
1763 | if (packet_id == tmp_nc_packet->packet_id) { | |
1764 | list_del(&tmp_nc_packet->list); | |
1765 | ||
1766 | nc_packet = tmp_nc_packet; | |
1767 | break; | |
1768 | } | |
1769 | } | |
1770 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1771 | ||
1772 | if (nc_packet) | |
1773 | break; | |
1774 | } | |
1775 | rcu_read_unlock(); | |
1776 | ||
1777 | if (!nc_packet) | |
1778 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1779 | "No decoding packet found for %u\n", packet_id); | |
1780 | ||
1781 | return nc_packet; | |
1782 | } | |
1783 | ||
1784 | /** | |
7e9a8c2c | 1785 | * batadv_nc_recv_coded_packet() - try to decode coded packet and enqueue the |
2df5278b MH |
1786 | * resulting unicast packet |
1787 | * @skb: incoming coded packet | |
1788 | * @recv_if: pointer to interface this packet was received on | |
672e7978 SE |
1789 | * |
1790 | * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP | |
1791 | * otherwise. | |
2df5278b MH |
1792 | */ |
1793 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1794 | struct batadv_hard_iface *recv_if) | |
1795 | { | |
1796 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1797 | struct batadv_unicast_packet *unicast_packet; | |
1798 | struct batadv_coded_packet *coded_packet; | |
1799 | struct batadv_nc_packet *nc_packet; | |
1800 | struct ethhdr *ethhdr; | |
1801 | int hdr_size = sizeof(*coded_packet); | |
1802 | ||
1803 | /* Check if network coding is enabled */ | |
1804 | if (!atomic_read(&bat_priv->network_coding)) | |
b91a2543 | 1805 | goto free_skb; |
2df5278b MH |
1806 | |
1807 | /* Make sure we can access (and remove) header */ | |
1808 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
b91a2543 | 1809 | goto free_skb; |
2df5278b MH |
1810 | |
1811 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1812 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1813 | |
1814 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1815 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1816 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
b91a2543 | 1817 | goto free_skb; |
2df5278b MH |
1818 | |
1819 | /* Update stat counter */ | |
6e0895c2 | 1820 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1821 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1822 | ||
1823 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1824 | coded_packet); | |
1825 | if (!nc_packet) { | |
1826 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
b91a2543 | 1827 | goto free_skb; |
2df5278b MH |
1828 | } |
1829 | ||
1830 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1831 | if (skb_linearize(skb) < 0) | |
1832 | goto free_nc_packet; | |
1833 | ||
1834 | if (skb_linearize(nc_packet->skb) < 0) | |
1835 | goto free_nc_packet; | |
1836 | ||
1837 | /* Decode the packet */ | |
6e0895c2 | 1838 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1839 | if (!unicast_packet) { |
1840 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1841 | goto free_nc_packet; | |
1842 | } | |
1843 | ||
1844 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1845 | BATADV_SKB_CB(skb)->decoded = true; | |
1846 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1847 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1848 | skb->len + ETH_HLEN); | |
1849 | return batadv_recv_unicast_packet(skb, recv_if); | |
1850 | ||
1851 | free_nc_packet: | |
bd687fe4 | 1852 | batadv_nc_packet_free(nc_packet, true); |
b91a2543 SE |
1853 | free_skb: |
1854 | kfree_skb(skb); | |
1855 | ||
2df5278b MH |
1856 | return NET_RX_DROP; |
1857 | } | |
1858 | ||
d353d8d4 | 1859 | /** |
7e9a8c2c | 1860 | * batadv_nc_mesh_free() - clean up network coding memory |
d353d8d4 MH |
1861 | * @bat_priv: the bat priv with all the soft interface information |
1862 | */ | |
6c519bad | 1863 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
d353d8d4 | 1864 | { |
3f4841ff ML |
1865 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1866 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
d353d8d4 | 1867 | cancel_delayed_work_sync(&bat_priv->nc.work); |
612d2b4f | 1868 | |
95332477 MH |
1869 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1870 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1871 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1872 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1873 | } |