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[linux-2.6/next.git] / net / mac80211 / key.c
blobe8f6e3b252d8b8ee3ef4210695dfc44283534bc4
1 /*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
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.
12 #include <linux/if_ether.h>
13 #include <linux/etherdevice.h>
14 #include <linux/list.h>
15 #include <linux/rcupdate.h>
16 #include <linux/rtnetlink.h>
17 #include <linux/slab.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "driver-ops.h"
21 #include "debugfs_key.h"
22 #include "aes_ccm.h"
23 #include "aes_cmac.h"
26 /**
27 * DOC: Key handling basics
29 * Key handling in mac80211 is done based on per-interface (sub_if_data)
30 * keys and per-station keys. Since each station belongs to an interface,
31 * each station key also belongs to that interface.
33 * Hardware acceleration is done on a best-effort basis, for each key
34 * that is eligible the hardware is asked to enable that key but if
35 * it cannot do that they key is simply kept for software encryption.
36 * There is currently no way of knowing this except by looking into
37 * debugfs.
39 * All key operations are protected internally so you can call them at
40 * any time.
42 * Within mac80211, key references are, just as STA structure references,
43 * protected by RCU. Note, however, that some things are unprotected,
44 * namely the key->sta dereferences within the hardware acceleration
45 * functions. This means that sta_info_destroy() must flush the key todo
46 * list.
48 * All the direct key list manipulation functions must not sleep because
49 * they can operate on STA info structs that are protected by RCU.
52 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
54 /* key mutex: used to synchronise todo runners */
55 static DEFINE_MUTEX(key_mutex);
56 static DEFINE_SPINLOCK(todo_lock);
57 static LIST_HEAD(todo_list);
59 static void key_todo(struct work_struct *work)
61 ieee80211_key_todo();
64 static DECLARE_WORK(todo_work, key_todo);
66 /**
67 * add_todo - add todo item for a key
69 * @key: key to add to do item for
70 * @flag: todo flag(s)
72 * Must be called with IRQs or softirqs disabled.
74 static void add_todo(struct ieee80211_key *key, u32 flag)
76 if (!key)
77 return;
79 spin_lock(&todo_lock);
80 key->flags |= flag;
82 * Remove again if already on the list so that we move it to the end.
84 if (!list_empty(&key->todo))
85 list_del(&key->todo);
86 list_add_tail(&key->todo, &todo_list);
87 schedule_work(&todo_work);
88 spin_unlock(&todo_lock);
91 /**
92 * ieee80211_key_lock - lock the mac80211 key operation lock
94 * This locks the (global) mac80211 key operation lock, all
95 * key operations must be done under this lock.
97 static void ieee80211_key_lock(void)
99 mutex_lock(&key_mutex);
103 * ieee80211_key_unlock - unlock the mac80211 key operation lock
105 static void ieee80211_key_unlock(void)
107 mutex_unlock(&key_mutex);
110 static void assert_key_lock(void)
112 WARN_ON(!mutex_is_locked(&key_mutex));
115 static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
117 if (key->sta)
118 return &key->sta->sta;
120 return NULL;
123 static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
125 struct ieee80211_sub_if_data *sdata;
126 struct ieee80211_sta *sta;
127 int ret;
129 assert_key_lock();
130 might_sleep();
132 if (!key->local->ops->set_key)
133 return;
135 sta = get_sta_for_key(key);
137 sdata = key->sdata;
138 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
139 sdata = container_of(sdata->bss,
140 struct ieee80211_sub_if_data,
141 u.ap);
143 ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
145 if (!ret) {
146 spin_lock_bh(&todo_lock);
147 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
148 spin_unlock_bh(&todo_lock);
151 if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
152 printk(KERN_ERR "mac80211-%s: failed to set key "
153 "(%d, %pM) to hardware (%d)\n",
154 wiphy_name(key->local->hw.wiphy),
155 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
158 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
160 struct ieee80211_sub_if_data *sdata;
161 struct ieee80211_sta *sta;
162 int ret;
164 assert_key_lock();
165 might_sleep();
167 if (!key || !key->local->ops->set_key)
168 return;
170 spin_lock_bh(&todo_lock);
171 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
172 spin_unlock_bh(&todo_lock);
173 return;
175 spin_unlock_bh(&todo_lock);
177 sta = get_sta_for_key(key);
178 sdata = key->sdata;
180 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
181 sdata = container_of(sdata->bss,
182 struct ieee80211_sub_if_data,
183 u.ap);
185 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
186 sta, &key->conf);
188 if (ret)
189 printk(KERN_ERR "mac80211-%s: failed to remove key "
190 "(%d, %pM) from hardware (%d)\n",
191 wiphy_name(key->local->hw.wiphy),
192 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
194 spin_lock_bh(&todo_lock);
195 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
196 spin_unlock_bh(&todo_lock);
199 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
200 int idx)
202 struct ieee80211_key *key = NULL;
204 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
205 key = sdata->keys[idx];
207 rcu_assign_pointer(sdata->default_key, key);
209 if (key)
210 add_todo(key, KEY_FLAG_TODO_DEFKEY);
213 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
215 unsigned long flags;
217 spin_lock_irqsave(&sdata->local->key_lock, flags);
218 __ieee80211_set_default_key(sdata, idx);
219 spin_unlock_irqrestore(&sdata->local->key_lock, flags);
222 static void
223 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
225 struct ieee80211_key *key = NULL;
227 if (idx >= NUM_DEFAULT_KEYS &&
228 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
229 key = sdata->keys[idx];
231 rcu_assign_pointer(sdata->default_mgmt_key, key);
233 if (key)
234 add_todo(key, KEY_FLAG_TODO_DEFMGMTKEY);
237 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
238 int idx)
240 unsigned long flags;
242 spin_lock_irqsave(&sdata->local->key_lock, flags);
243 __ieee80211_set_default_mgmt_key(sdata, idx);
244 spin_unlock_irqrestore(&sdata->local->key_lock, flags);
248 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
249 struct sta_info *sta,
250 struct ieee80211_key *old,
251 struct ieee80211_key *new)
253 int idx, defkey, defmgmtkey;
255 if (new)
256 list_add(&new->list, &sdata->key_list);
258 if (sta) {
259 rcu_assign_pointer(sta->key, new);
260 } else {
261 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
263 if (old)
264 idx = old->conf.keyidx;
265 else
266 idx = new->conf.keyidx;
268 defkey = old && sdata->default_key == old;
269 defmgmtkey = old && sdata->default_mgmt_key == old;
271 if (defkey && !new)
272 __ieee80211_set_default_key(sdata, -1);
273 if (defmgmtkey && !new)
274 __ieee80211_set_default_mgmt_key(sdata, -1);
276 rcu_assign_pointer(sdata->keys[idx], new);
277 if (defkey && new)
278 __ieee80211_set_default_key(sdata, new->conf.keyidx);
279 if (defmgmtkey && new)
280 __ieee80211_set_default_mgmt_key(sdata,
281 new->conf.keyidx);
284 if (old) {
286 * We'll use an empty list to indicate that the key
287 * has already been removed.
289 list_del_init(&old->list);
293 struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
294 int idx,
295 size_t key_len,
296 const u8 *key_data,
297 size_t seq_len, const u8 *seq)
299 struct ieee80211_key *key;
300 int i, j;
302 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
304 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
305 if (!key)
306 return NULL;
309 * Default to software encryption; we'll later upload the
310 * key to the hardware if possible.
312 key->conf.flags = 0;
313 key->flags = 0;
315 key->conf.alg = alg;
316 key->conf.keyidx = idx;
317 key->conf.keylen = key_len;
318 switch (alg) {
319 case ALG_WEP:
320 key->conf.iv_len = WEP_IV_LEN;
321 key->conf.icv_len = WEP_ICV_LEN;
322 break;
323 case ALG_TKIP:
324 key->conf.iv_len = TKIP_IV_LEN;
325 key->conf.icv_len = TKIP_ICV_LEN;
326 if (seq) {
327 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
328 key->u.tkip.rx[i].iv32 =
329 get_unaligned_le32(&seq[2]);
330 key->u.tkip.rx[i].iv16 =
331 get_unaligned_le16(seq);
334 break;
335 case ALG_CCMP:
336 key->conf.iv_len = CCMP_HDR_LEN;
337 key->conf.icv_len = CCMP_MIC_LEN;
338 if (seq) {
339 for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
340 for (j = 0; j < CCMP_PN_LEN; j++)
341 key->u.ccmp.rx_pn[i][j] =
342 seq[CCMP_PN_LEN - j - 1];
344 break;
345 case ALG_AES_CMAC:
346 key->conf.iv_len = 0;
347 key->conf.icv_len = sizeof(struct ieee80211_mmie);
348 if (seq)
349 for (j = 0; j < 6; j++)
350 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
351 break;
353 memcpy(key->conf.key, key_data, key_len);
354 INIT_LIST_HEAD(&key->list);
355 INIT_LIST_HEAD(&key->todo);
357 if (alg == ALG_CCMP) {
359 * Initialize AES key state here as an optimization so that
360 * it does not need to be initialized for every packet.
362 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
363 if (!key->u.ccmp.tfm) {
364 kfree(key);
365 return NULL;
369 if (alg == ALG_AES_CMAC) {
371 * Initialize AES key state here as an optimization so that
372 * it does not need to be initialized for every packet.
374 key->u.aes_cmac.tfm =
375 ieee80211_aes_cmac_key_setup(key_data);
376 if (!key->u.aes_cmac.tfm) {
377 kfree(key);
378 return NULL;
382 return key;
385 void ieee80211_key_link(struct ieee80211_key *key,
386 struct ieee80211_sub_if_data *sdata,
387 struct sta_info *sta)
389 struct ieee80211_key *old_key;
390 unsigned long flags;
391 int idx;
393 BUG_ON(!sdata);
394 BUG_ON(!key);
396 idx = key->conf.keyidx;
397 key->local = sdata->local;
398 key->sdata = sdata;
399 key->sta = sta;
401 if (sta) {
403 * some hardware cannot handle TKIP with QoS, so
404 * we indicate whether QoS could be in use.
406 if (test_sta_flags(sta, WLAN_STA_WME))
407 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
410 * This key is for a specific sta interface,
411 * inform the driver that it should try to store
412 * this key as pairwise key.
414 key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
415 } else {
416 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
417 struct sta_info *ap;
420 * We're getting a sta pointer in,
421 * so must be under RCU read lock.
424 /* same here, the AP could be using QoS */
425 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
426 if (ap) {
427 if (test_sta_flags(ap, WLAN_STA_WME))
428 key->conf.flags |=
429 IEEE80211_KEY_FLAG_WMM_STA;
434 spin_lock_irqsave(&sdata->local->key_lock, flags);
436 if (sta)
437 old_key = sta->key;
438 else
439 old_key = sdata->keys[idx];
441 __ieee80211_key_replace(sdata, sta, old_key, key);
443 /* free old key later */
444 add_todo(old_key, KEY_FLAG_TODO_DELETE);
446 add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS);
447 if (ieee80211_sdata_running(sdata))
448 add_todo(key, KEY_FLAG_TODO_HWACCEL_ADD);
450 spin_unlock_irqrestore(&sdata->local->key_lock, flags);
453 static void __ieee80211_key_free(struct ieee80211_key *key)
456 * Replace key with nothingness if it was ever used.
458 if (key->sdata)
459 __ieee80211_key_replace(key->sdata, key->sta,
460 key, NULL);
462 add_todo(key, KEY_FLAG_TODO_DELETE);
465 void ieee80211_key_free(struct ieee80211_key *key)
467 unsigned long flags;
469 if (!key)
470 return;
472 if (!key->sdata) {
473 /* The key has not been linked yet, simply free it
474 * and don't Oops */
475 if (key->conf.alg == ALG_CCMP)
476 ieee80211_aes_key_free(key->u.ccmp.tfm);
477 kfree(key);
478 return;
481 spin_lock_irqsave(&key->sdata->local->key_lock, flags);
482 __ieee80211_key_free(key);
483 spin_unlock_irqrestore(&key->sdata->local->key_lock, flags);
487 * To be safe against concurrent manipulations of the list (which shouldn't
488 * actually happen) we need to hold the spinlock. But under the spinlock we
489 * can't actually do much, so we defer processing to the todo list. Then run
490 * the todo list to be sure the operation and possibly previously pending
491 * operations are completed.
493 static void ieee80211_todo_for_each_key(struct ieee80211_sub_if_data *sdata,
494 u32 todo_flags)
496 struct ieee80211_key *key;
497 unsigned long flags;
499 might_sleep();
501 spin_lock_irqsave(&sdata->local->key_lock, flags);
502 list_for_each_entry(key, &sdata->key_list, list)
503 add_todo(key, todo_flags);
504 spin_unlock_irqrestore(&sdata->local->key_lock, flags);
506 ieee80211_key_todo();
509 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
511 ASSERT_RTNL();
513 if (WARN_ON(!ieee80211_sdata_running(sdata)))
514 return;
516 ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_ADD);
519 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
521 ASSERT_RTNL();
523 ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_REMOVE);
526 static void __ieee80211_key_destroy(struct ieee80211_key *key)
528 if (!key)
529 return;
531 ieee80211_key_disable_hw_accel(key);
533 if (key->conf.alg == ALG_CCMP)
534 ieee80211_aes_key_free(key->u.ccmp.tfm);
535 if (key->conf.alg == ALG_AES_CMAC)
536 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
537 ieee80211_debugfs_key_remove(key);
539 kfree(key);
542 static void __ieee80211_key_todo(void)
544 struct ieee80211_key *key;
545 bool work_done;
546 u32 todoflags;
549 * NB: sta_info_destroy relies on this!
551 synchronize_rcu();
553 spin_lock_bh(&todo_lock);
554 while (!list_empty(&todo_list)) {
555 key = list_first_entry(&todo_list, struct ieee80211_key, todo);
556 list_del_init(&key->todo);
557 todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS |
558 KEY_FLAG_TODO_DEFKEY |
559 KEY_FLAG_TODO_DEFMGMTKEY |
560 KEY_FLAG_TODO_HWACCEL_ADD |
561 KEY_FLAG_TODO_HWACCEL_REMOVE |
562 KEY_FLAG_TODO_DELETE);
563 key->flags &= ~todoflags;
564 spin_unlock_bh(&todo_lock);
566 work_done = false;
568 if (todoflags & KEY_FLAG_TODO_ADD_DEBUGFS) {
569 ieee80211_debugfs_key_add(key);
570 work_done = true;
572 if (todoflags & KEY_FLAG_TODO_DEFKEY) {
573 ieee80211_debugfs_key_remove_default(key->sdata);
574 ieee80211_debugfs_key_add_default(key->sdata);
575 work_done = true;
577 if (todoflags & KEY_FLAG_TODO_DEFMGMTKEY) {
578 ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
579 ieee80211_debugfs_key_add_mgmt_default(key->sdata);
580 work_done = true;
582 if (todoflags & KEY_FLAG_TODO_HWACCEL_ADD) {
583 ieee80211_key_enable_hw_accel(key);
584 work_done = true;
586 if (todoflags & KEY_FLAG_TODO_HWACCEL_REMOVE) {
587 ieee80211_key_disable_hw_accel(key);
588 work_done = true;
590 if (todoflags & KEY_FLAG_TODO_DELETE) {
591 __ieee80211_key_destroy(key);
592 work_done = true;
595 WARN_ON(!work_done);
597 spin_lock_bh(&todo_lock);
599 spin_unlock_bh(&todo_lock);
602 void ieee80211_key_todo(void)
604 ieee80211_key_lock();
605 __ieee80211_key_todo();
606 ieee80211_key_unlock();
609 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
611 struct ieee80211_key *key, *tmp;
612 unsigned long flags;
614 ieee80211_key_lock();
616 ieee80211_debugfs_key_remove_default(sdata);
617 ieee80211_debugfs_key_remove_mgmt_default(sdata);
619 spin_lock_irqsave(&sdata->local->key_lock, flags);
620 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
621 __ieee80211_key_free(key);
622 spin_unlock_irqrestore(&sdata->local->key_lock, flags);
624 __ieee80211_key_todo();
626 ieee80211_key_unlock();