Commit | Line | Data |
---|---|---|
1f5a7e47 JB |
1 | /* |
2 | * Copyright 2002-2005, Instant802 Networks, Inc. | |
3 | * Copyright 2005-2006, Devicescape Software, Inc. | |
4 | * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> | |
3b96766f | 5 | * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net> |
1f5a7e47 JB |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
11a843b7 JB |
12 | #include <linux/if_ether.h> |
13 | #include <linux/etherdevice.h> | |
14 | #include <linux/list.h> | |
d4e46a3d | 15 | #include <linux/rcupdate.h> |
db4d1169 | 16 | #include <linux/rtnetlink.h> |
1f5a7e47 JB |
17 | #include <net/mac80211.h> |
18 | #include "ieee80211_i.h" | |
19 | #include "debugfs_key.h" | |
20 | #include "aes_ccm.h" | |
21 | ||
11a843b7 | 22 | |
dbbea671 JB |
23 | /** |
24 | * DOC: Key handling basics | |
11a843b7 JB |
25 | * |
26 | * Key handling in mac80211 is done based on per-interface (sub_if_data) | |
27 | * keys and per-station keys. Since each station belongs to an interface, | |
28 | * each station key also belongs to that interface. | |
29 | * | |
30 | * Hardware acceleration is done on a best-effort basis, for each key | |
31 | * that is eligible the hardware is asked to enable that key but if | |
32 | * it cannot do that they key is simply kept for software encryption. | |
33 | * There is currently no way of knowing this except by looking into | |
34 | * debugfs. | |
35 | * | |
3b96766f JB |
36 | * All key operations are protected internally so you can call them at |
37 | * any time. | |
db4d1169 | 38 | * |
3b96766f JB |
39 | * Within mac80211, key references are, just as STA structure references, |
40 | * protected by RCU. Note, however, that some things are unprotected, | |
41 | * namely the key->sta dereferences within the hardware acceleration | |
42 | * functions. This means that sta_info_destroy() must flush the key todo | |
43 | * list. | |
44 | * | |
45 | * All the direct key list manipulation functions must not sleep because | |
46 | * they can operate on STA info structs that are protected by RCU. | |
11a843b7 JB |
47 | */ |
48 | ||
49 | static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; | |
50 | static const u8 zero_addr[ETH_ALEN]; | |
51 | ||
3b96766f JB |
52 | /* key mutex: used to synchronise todo runners */ |
53 | static DEFINE_MUTEX(key_mutex); | |
54 | static DEFINE_SPINLOCK(todo_lock); | |
55 | static LIST_HEAD(todo_list); | |
56 | ||
57 | static void key_todo(struct work_struct *work) | |
58 | { | |
59 | ieee80211_key_todo(); | |
60 | } | |
61 | ||
62 | static DECLARE_WORK(todo_work, key_todo); | |
63 | ||
64 | /** | |
65 | * add_todo - add todo item for a key | |
66 | * | |
67 | * @key: key to add to do item for | |
68 | * @flag: todo flag(s) | |
69 | */ | |
70 | static void add_todo(struct ieee80211_key *key, u32 flag) | |
71 | { | |
72 | if (!key) | |
73 | return; | |
74 | ||
75 | spin_lock(&todo_lock); | |
76 | key->flags |= flag; | |
77 | /* only add if not already added */ | |
78 | if (list_empty(&key->todo)) | |
79 | list_add(&key->todo, &todo_list); | |
80 | schedule_work(&todo_work); | |
81 | spin_unlock(&todo_lock); | |
82 | } | |
83 | ||
84 | /** | |
85 | * ieee80211_key_lock - lock the mac80211 key operation lock | |
86 | * | |
87 | * This locks the (global) mac80211 key operation lock, all | |
88 | * key operations must be done under this lock. | |
89 | */ | |
90 | static void ieee80211_key_lock(void) | |
91 | { | |
92 | mutex_lock(&key_mutex); | |
93 | } | |
94 | ||
95 | /** | |
96 | * ieee80211_key_unlock - unlock the mac80211 key operation lock | |
97 | */ | |
98 | static void ieee80211_key_unlock(void) | |
99 | { | |
100 | mutex_unlock(&key_mutex); | |
101 | } | |
102 | ||
103 | static void assert_key_lock(void) | |
104 | { | |
105 | WARN_ON(!mutex_is_locked(&key_mutex)); | |
106 | } | |
107 | ||
11a843b7 JB |
108 | static const u8 *get_mac_for_key(struct ieee80211_key *key) |
109 | { | |
110 | const u8 *addr = bcast_addr; | |
111 | ||
112 | /* | |
113 | * If we're an AP we won't ever receive frames with a non-WEP | |
114 | * group key so we tell the driver that by using the zero MAC | |
115 | * address to indicate a transmit-only key. | |
116 | */ | |
117 | if (key->conf.alg != ALG_WEP && | |
51fb61e7 JB |
118 | (key->sdata->vif.type == IEEE80211_IF_TYPE_AP || |
119 | key->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) | |
11a843b7 JB |
120 | addr = zero_addr; |
121 | ||
122 | if (key->sta) | |
123 | addr = key->sta->addr; | |
124 | ||
125 | return addr; | |
126 | } | |
127 | ||
128 | static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key) | |
129 | { | |
130 | const u8 *addr; | |
131 | int ret; | |
0795af57 | 132 | DECLARE_MAC_BUF(mac); |
11a843b7 | 133 | |
3b96766f JB |
134 | assert_key_lock(); |
135 | might_sleep(); | |
136 | ||
11a843b7 JB |
137 | if (!key->local->ops->set_key) |
138 | return; | |
139 | ||
140 | addr = get_mac_for_key(key); | |
141 | ||
142 | ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY, | |
143 | key->sdata->dev->dev_addr, addr, | |
144 | &key->conf); | |
145 | ||
3b96766f JB |
146 | if (!ret) { |
147 | spin_lock(&todo_lock); | |
11a843b7 | 148 | key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE; |
3b96766f JB |
149 | spin_unlock(&todo_lock); |
150 | } | |
11a843b7 JB |
151 | |
152 | if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP) | |
153 | printk(KERN_ERR "mac80211-%s: failed to set key " | |
0795af57 | 154 | "(%d, %s) to hardware (%d)\n", |
11a843b7 | 155 | wiphy_name(key->local->hw.wiphy), |
0795af57 | 156 | key->conf.keyidx, print_mac(mac, addr), ret); |
11a843b7 JB |
157 | } |
158 | ||
159 | static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) | |
160 | { | |
161 | const u8 *addr; | |
162 | int ret; | |
0795af57 | 163 | DECLARE_MAC_BUF(mac); |
11a843b7 | 164 | |
3b96766f JB |
165 | assert_key_lock(); |
166 | might_sleep(); | |
167 | ||
db4d1169 | 168 | if (!key || !key->local->ops->set_key) |
11a843b7 JB |
169 | return; |
170 | ||
3b96766f JB |
171 | spin_lock(&todo_lock); |
172 | if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) { | |
173 | spin_unlock(&todo_lock); | |
11a843b7 | 174 | return; |
3b96766f JB |
175 | } |
176 | spin_unlock(&todo_lock); | |
11a843b7 JB |
177 | |
178 | addr = get_mac_for_key(key); | |
179 | ||
180 | ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY, | |
181 | key->sdata->dev->dev_addr, addr, | |
182 | &key->conf); | |
183 | ||
184 | if (ret) | |
185 | printk(KERN_ERR "mac80211-%s: failed to remove key " | |
0795af57 | 186 | "(%d, %s) from hardware (%d)\n", |
11a843b7 | 187 | wiphy_name(key->local->hw.wiphy), |
0795af57 | 188 | key->conf.keyidx, print_mac(mac, addr), ret); |
11a843b7 | 189 | |
3b96766f JB |
190 | spin_lock(&todo_lock); |
191 | key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; | |
192 | spin_unlock(&todo_lock); | |
193 | } | |
194 | ||
195 | static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, | |
196 | int idx) | |
197 | { | |
198 | struct ieee80211_key *key = NULL; | |
199 | ||
200 | if (idx >= 0 && idx < NUM_DEFAULT_KEYS) | |
201 | key = sdata->keys[idx]; | |
202 | ||
203 | rcu_assign_pointer(sdata->default_key, key); | |
204 | ||
205 | if (key) | |
206 | add_todo(key, KEY_FLAG_TODO_DEFKEY); | |
207 | } | |
208 | ||
209 | void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx) | |
210 | { | |
211 | unsigned long flags; | |
212 | ||
213 | spin_lock_irqsave(&sdata->local->sta_lock, flags); | |
214 | __ieee80211_set_default_key(sdata, idx); | |
215 | spin_unlock_irqrestore(&sdata->local->sta_lock, flags); | |
216 | } | |
217 | ||
218 | ||
219 | static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, | |
220 | struct sta_info *sta, | |
221 | struct ieee80211_key *old, | |
222 | struct ieee80211_key *new) | |
223 | { | |
224 | int idx, defkey; | |
225 | ||
226 | if (new) | |
227 | list_add(&new->list, &sdata->key_list); | |
228 | ||
229 | if (sta) { | |
230 | rcu_assign_pointer(sta->key, new); | |
231 | } else { | |
232 | WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx); | |
233 | ||
234 | if (old) | |
235 | idx = old->conf.keyidx; | |
236 | else | |
237 | idx = new->conf.keyidx; | |
238 | ||
239 | defkey = old && sdata->default_key == old; | |
240 | ||
241 | if (defkey && !new) | |
242 | __ieee80211_set_default_key(sdata, -1); | |
243 | ||
244 | rcu_assign_pointer(sdata->keys[idx], new); | |
245 | if (defkey && new) | |
246 | __ieee80211_set_default_key(sdata, new->conf.keyidx); | |
247 | } | |
248 | ||
249 | if (old) { | |
250 | /* | |
251 | * We'll use an empty list to indicate that the key | |
252 | * has already been removed. | |
253 | */ | |
254 | list_del_init(&old->list); | |
255 | } | |
11a843b7 JB |
256 | } |
257 | ||
db4d1169 | 258 | struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg, |
11a843b7 JB |
259 | int idx, |
260 | size_t key_len, | |
261 | const u8 *key_data) | |
1f5a7e47 JB |
262 | { |
263 | struct ieee80211_key *key; | |
264 | ||
d4e46a3d | 265 | BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS); |
11a843b7 JB |
266 | |
267 | key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL); | |
1f5a7e47 JB |
268 | if (!key) |
269 | return NULL; | |
11a843b7 JB |
270 | |
271 | /* | |
272 | * Default to software encryption; we'll later upload the | |
273 | * key to the hardware if possible. | |
274 | */ | |
11a843b7 JB |
275 | key->conf.flags = 0; |
276 | key->flags = 0; | |
277 | ||
278 | key->conf.alg = alg; | |
279 | key->conf.keyidx = idx; | |
280 | key->conf.keylen = key_len; | |
281 | memcpy(key->conf.key, key_data, key_len); | |
e4861829 | 282 | INIT_LIST_HEAD(&key->list); |
3b96766f | 283 | INIT_LIST_HEAD(&key->todo); |
11a843b7 | 284 | |
11a843b7 JB |
285 | if (alg == ALG_CCMP) { |
286 | /* | |
287 | * Initialize AES key state here as an optimization so that | |
288 | * it does not need to be initialized for every packet. | |
289 | */ | |
290 | key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data); | |
291 | if (!key->u.ccmp.tfm) { | |
3b96766f | 292 | kfree(key); |
11a843b7 JB |
293 | return NULL; |
294 | } | |
295 | } | |
296 | ||
db4d1169 JB |
297 | return key; |
298 | } | |
11a843b7 | 299 | |
db4d1169 JB |
300 | void ieee80211_key_link(struct ieee80211_key *key, |
301 | struct ieee80211_sub_if_data *sdata, | |
302 | struct sta_info *sta) | |
303 | { | |
304 | struct ieee80211_key *old_key; | |
3b96766f | 305 | unsigned long flags; |
db4d1169 JB |
306 | int idx; |
307 | ||
db4d1169 JB |
308 | BUG_ON(!sdata); |
309 | BUG_ON(!key); | |
310 | ||
311 | idx = key->conf.keyidx; | |
312 | key->local = sdata->local; | |
313 | key->sdata = sdata; | |
314 | key->sta = sta; | |
315 | ||
11a843b7 | 316 | if (sta) { |
11a843b7 JB |
317 | /* |
318 | * some hardware cannot handle TKIP with QoS, so | |
319 | * we indicate whether QoS could be in use. | |
320 | */ | |
321 | if (sta->flags & WLAN_STA_WME) | |
322 | key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA; | |
323 | } else { | |
51fb61e7 | 324 | if (sdata->vif.type == IEEE80211_IF_TYPE_STA) { |
11a843b7 JB |
325 | struct sta_info *ap; |
326 | ||
3b96766f JB |
327 | /* |
328 | * We're getting a sta pointer in, | |
329 | * so must be under RCU read lock. | |
330 | */ | |
d0709a65 | 331 | |
11a843b7 JB |
332 | /* same here, the AP could be using QoS */ |
333 | ap = sta_info_get(key->local, key->sdata->u.sta.bssid); | |
334 | if (ap) { | |
335 | if (ap->flags & WLAN_STA_WME) | |
336 | key->conf.flags |= | |
337 | IEEE80211_KEY_FLAG_WMM_STA; | |
11a843b7 JB |
338 | } |
339 | } | |
11a843b7 JB |
340 | } |
341 | ||
3b96766f JB |
342 | spin_lock_irqsave(&sdata->local->sta_lock, flags); |
343 | ||
d4e46a3d | 344 | if (sta) |
db4d1169 | 345 | old_key = sta->key; |
d4e46a3d | 346 | else |
db4d1169 JB |
347 | old_key = sdata->keys[idx]; |
348 | ||
349 | __ieee80211_key_replace(sdata, sta, old_key, key); | |
d4e46a3d | 350 | |
3b96766f JB |
351 | spin_unlock_irqrestore(&sdata->local->sta_lock, flags); |
352 | ||
353 | /* free old key later */ | |
354 | add_todo(old_key, KEY_FLAG_TODO_DELETE); | |
db4d1169 | 355 | |
3b96766f | 356 | add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS); |
e4861829 | 357 | if (netif_running(sdata->dev)) |
3b96766f | 358 | add_todo(key, KEY_FLAG_TODO_HWACCEL); |
1f5a7e47 JB |
359 | } |
360 | ||
8f37171a | 361 | void ieee80211_key_free(struct ieee80211_key *key) |
1f5a7e47 | 362 | { |
3b96766f | 363 | unsigned long flags; |
db4d1169 | 364 | |
8f37171a JB |
365 | if (!key) |
366 | return; | |
1f5a7e47 | 367 | |
3b96766f JB |
368 | /* |
369 | * Replace key with nothingness if it was ever used. | |
370 | */ | |
db4d1169 | 371 | if (key->sdata) { |
3b96766f JB |
372 | spin_lock_irqsave(&key->sdata->local->sta_lock, flags); |
373 | __ieee80211_key_replace(key->sdata, key->sta, | |
374 | key, NULL); | |
375 | spin_unlock_irqrestore(&key->sdata->local->sta_lock, flags); | |
376 | } | |
11a843b7 | 377 | |
3b96766f JB |
378 | add_todo(key, KEY_FLAG_TODO_DELETE); |
379 | } | |
d4e46a3d | 380 | |
3b96766f JB |
381 | void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata) |
382 | { | |
383 | struct ieee80211_key *key; | |
d4e46a3d | 384 | |
3b96766f | 385 | might_sleep(); |
11a843b7 | 386 | |
3b96766f JB |
387 | if (WARN_ON(!netif_running(sdata->dev))) |
388 | return; | |
389 | ||
390 | ieee80211_key_lock(); | |
391 | ||
392 | list_for_each_entry(key, &sdata->key_list, list) | |
393 | ieee80211_key_enable_hw_accel(key); | |
394 | ||
395 | ieee80211_key_unlock(); | |
1f5a7e47 | 396 | } |
11a843b7 | 397 | |
3b96766f | 398 | void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata) |
11a843b7 | 399 | { |
3b96766f | 400 | struct ieee80211_key *key; |
11a843b7 | 401 | |
3b96766f | 402 | might_sleep(); |
11a843b7 | 403 | |
3b96766f | 404 | ieee80211_key_lock(); |
11a843b7 | 405 | |
3b96766f JB |
406 | list_for_each_entry(key, &sdata->key_list, list) |
407 | ieee80211_key_disable_hw_accel(key); | |
11a843b7 | 408 | |
3b96766f | 409 | ieee80211_key_unlock(); |
11a843b7 JB |
410 | } |
411 | ||
3b96766f | 412 | static void __ieee80211_key_free(struct ieee80211_key *key) |
11a843b7 | 413 | { |
3b96766f JB |
414 | if (!key) |
415 | return; | |
db4d1169 | 416 | |
3b96766f | 417 | ieee80211_key_disable_hw_accel(key); |
11a843b7 | 418 | |
3b96766f JB |
419 | if (key->conf.alg == ALG_CCMP) |
420 | ieee80211_aes_key_free(key->u.ccmp.tfm); | |
421 | ieee80211_debugfs_key_remove(key); | |
422 | ||
423 | kfree(key); | |
11a843b7 JB |
424 | } |
425 | ||
3b96766f | 426 | static void __ieee80211_key_todo(void) |
11a843b7 JB |
427 | { |
428 | struct ieee80211_key *key; | |
3b96766f JB |
429 | bool work_done; |
430 | u32 todoflags; | |
11a843b7 | 431 | |
3b96766f JB |
432 | /* |
433 | * NB: sta_info_destroy relies on this! | |
434 | */ | |
435 | synchronize_rcu(); | |
436 | ||
437 | spin_lock(&todo_lock); | |
438 | while (!list_empty(&todo_list)) { | |
439 | key = list_first_entry(&todo_list, struct ieee80211_key, todo); | |
440 | list_del_init(&key->todo); | |
441 | todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS | | |
442 | KEY_FLAG_TODO_DEFKEY | | |
443 | KEY_FLAG_TODO_HWACCEL | | |
444 | KEY_FLAG_TODO_DELETE); | |
445 | key->flags &= ~todoflags; | |
446 | spin_unlock(&todo_lock); | |
447 | ||
448 | work_done = false; | |
449 | ||
450 | if (todoflags & KEY_FLAG_TODO_ADD_DEBUGFS) { | |
451 | ieee80211_debugfs_key_add(key); | |
452 | work_done = true; | |
453 | } | |
454 | if (todoflags & KEY_FLAG_TODO_DEFKEY) { | |
455 | ieee80211_debugfs_key_remove_default(key->sdata); | |
456 | ieee80211_debugfs_key_add_default(key->sdata); | |
457 | work_done = true; | |
458 | } | |
459 | if (todoflags & KEY_FLAG_TODO_HWACCEL) { | |
460 | ieee80211_key_enable_hw_accel(key); | |
461 | work_done = true; | |
462 | } | |
463 | if (todoflags & KEY_FLAG_TODO_DELETE) { | |
464 | __ieee80211_key_free(key); | |
465 | work_done = true; | |
466 | } | |
db4d1169 | 467 | |
3b96766f | 468 | WARN_ON(!work_done); |
11a843b7 | 469 | |
3b96766f JB |
470 | spin_lock(&todo_lock); |
471 | } | |
472 | spin_unlock(&todo_lock); | |
11a843b7 JB |
473 | } |
474 | ||
3b96766f | 475 | void ieee80211_key_todo(void) |
11a843b7 | 476 | { |
3b96766f JB |
477 | ieee80211_key_lock(); |
478 | __ieee80211_key_todo(); | |
479 | ieee80211_key_unlock(); | |
480 | } | |
11a843b7 | 481 | |
3b96766f JB |
482 | void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata) |
483 | { | |
484 | struct ieee80211_key *key, *tmp; | |
485 | LIST_HEAD(tmp_list); | |
db4d1169 | 486 | |
3b96766f JB |
487 | ieee80211_key_lock(); |
488 | ||
489 | ieee80211_debugfs_key_remove_default(sdata); | |
490 | ||
491 | list_for_each_entry_safe(key, tmp, &sdata->key_list, list) | |
492 | ieee80211_key_free(key); | |
493 | ||
494 | __ieee80211_key_todo(); | |
495 | ||
496 | ieee80211_key_unlock(); | |
11a843b7 | 497 | } |