Merge v3.2-rc4 into usb-next
[zen-stable.git] / net / mac80211 / key.c
blobfb02ea52d2c2b46f760944de0f407f417d0fb492
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 <linux/export.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "driver-ops.h"
22 #include "debugfs_key.h"
23 #include "aes_ccm.h"
24 #include "aes_cmac.h"
27 /**
28 * DOC: Key handling basics
30 * Key handling in mac80211 is done based on per-interface (sub_if_data)
31 * keys and per-station keys. Since each station belongs to an interface,
32 * each station key also belongs to that interface.
34 * Hardware acceleration is done on a best-effort basis for algorithms
35 * that are implemented in software, for each key the hardware is asked
36 * to enable that key for offloading but if it cannot do that the key is
37 * simply kept for software encryption (unless it is for an algorithm
38 * that isn't implemented in software).
39 * There is currently no way of knowing whether a key is handled in SW
40 * or HW except by looking into debugfs.
42 * All key management is internally protected by a mutex. Within all
43 * other parts of mac80211, key references are, just as STA structure
44 * references, protected by RCU. Note, however, that some things are
45 * unprotected, namely the key->sta dereferences within the hardware
46 * acceleration functions. This means that sta_info_destroy() must
47 * remove the key which waits for an RCU grace period.
50 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
52 static void assert_key_lock(struct ieee80211_local *local)
54 lockdep_assert_held(&local->key_mtx);
57 static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
59 if (key->sta)
60 return &key->sta->sta;
62 return NULL;
65 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
68 * When this count is zero, SKB resizing for allocating tailroom
69 * for IV or MMIC is skipped. But, this check has created two race
70 * cases in xmit path while transiting from zero count to one:
72 * 1. SKB resize was skipped because no key was added but just before
73 * the xmit key is added and SW encryption kicks off.
75 * 2. SKB resize was skipped because all the keys were hw planted but
76 * just before xmit one of the key is deleted and SW encryption kicks
77 * off.
79 * In both the above case SW encryption will find not enough space for
80 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
82 * Solution has been explained at
83 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
86 if (!sdata->crypto_tx_tailroom_needed_cnt++) {
88 * Flush all XMIT packets currently using HW encryption or no
89 * encryption at all if the count transition is from 0 -> 1.
91 synchronize_net();
95 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
97 struct ieee80211_sub_if_data *sdata;
98 struct ieee80211_sta *sta;
99 int ret;
101 might_sleep();
103 if (!key->local->ops->set_key)
104 goto out_unsupported;
106 assert_key_lock(key->local);
108 sta = get_sta_for_key(key);
111 * If this is a per-STA GTK, check if it
112 * is supported; if not, return.
114 if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
115 !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
116 goto out_unsupported;
118 sdata = key->sdata;
119 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
121 * The driver doesn't know anything about VLAN interfaces.
122 * Hence, don't send GTKs for VLAN interfaces to the driver.
124 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
125 goto out_unsupported;
126 sdata = container_of(sdata->bss,
127 struct ieee80211_sub_if_data,
128 u.ap);
131 ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
133 if (!ret) {
134 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
136 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
137 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
138 sdata->crypto_tx_tailroom_needed_cnt--;
140 return 0;
143 if (ret != -ENOSPC && ret != -EOPNOTSUPP)
144 wiphy_err(key->local->hw.wiphy,
145 "failed to set key (%d, %pM) to hardware (%d)\n",
146 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
148 out_unsupported:
149 switch (key->conf.cipher) {
150 case WLAN_CIPHER_SUITE_WEP40:
151 case WLAN_CIPHER_SUITE_WEP104:
152 case WLAN_CIPHER_SUITE_TKIP:
153 case WLAN_CIPHER_SUITE_CCMP:
154 case WLAN_CIPHER_SUITE_AES_CMAC:
155 /* all of these we can do in software */
156 return 0;
157 default:
158 return -EINVAL;
162 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
164 struct ieee80211_sub_if_data *sdata;
165 struct ieee80211_sta *sta;
166 int ret;
168 might_sleep();
170 if (!key || !key->local->ops->set_key)
171 return;
173 assert_key_lock(key->local);
175 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
176 return;
178 sta = get_sta_for_key(key);
179 sdata = key->sdata;
181 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
182 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
183 increment_tailroom_need_count(sdata);
185 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
186 sdata = container_of(sdata->bss,
187 struct ieee80211_sub_if_data,
188 u.ap);
190 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
191 sta, &key->conf);
193 if (ret)
194 wiphy_err(key->local->hw.wiphy,
195 "failed to remove key (%d, %pM) from hardware (%d)\n",
196 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
198 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
201 void ieee80211_key_removed(struct ieee80211_key_conf *key_conf)
203 struct ieee80211_key *key;
205 key = container_of(key_conf, struct ieee80211_key, conf);
207 might_sleep();
208 assert_key_lock(key->local);
210 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
213 * Flush TX path to avoid attempts to use this key
214 * after this function returns. Until then, drivers
215 * must be prepared to handle the key.
217 synchronize_rcu();
219 EXPORT_SYMBOL_GPL(ieee80211_key_removed);
221 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
222 int idx, bool uni, bool multi)
224 struct ieee80211_key *key = NULL;
226 assert_key_lock(sdata->local);
228 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
229 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
231 if (uni)
232 rcu_assign_pointer(sdata->default_unicast_key, key);
233 if (multi)
234 rcu_assign_pointer(sdata->default_multicast_key, key);
236 ieee80211_debugfs_key_update_default(sdata);
239 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
240 bool uni, bool multi)
242 mutex_lock(&sdata->local->key_mtx);
243 __ieee80211_set_default_key(sdata, idx, uni, multi);
244 mutex_unlock(&sdata->local->key_mtx);
247 static void
248 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
250 struct ieee80211_key *key = NULL;
252 assert_key_lock(sdata->local);
254 if (idx >= NUM_DEFAULT_KEYS &&
255 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
256 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
258 rcu_assign_pointer(sdata->default_mgmt_key, key);
260 ieee80211_debugfs_key_update_default(sdata);
263 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
264 int idx)
266 mutex_lock(&sdata->local->key_mtx);
267 __ieee80211_set_default_mgmt_key(sdata, idx);
268 mutex_unlock(&sdata->local->key_mtx);
272 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
273 struct sta_info *sta,
274 bool pairwise,
275 struct ieee80211_key *old,
276 struct ieee80211_key *new)
278 int idx;
279 bool defunikey, defmultikey, defmgmtkey;
281 if (new)
282 list_add_tail(&new->list, &sdata->key_list);
284 if (sta && pairwise) {
285 rcu_assign_pointer(sta->ptk, new);
286 } else if (sta) {
287 if (old)
288 idx = old->conf.keyidx;
289 else
290 idx = new->conf.keyidx;
291 rcu_assign_pointer(sta->gtk[idx], new);
292 } else {
293 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
295 if (old)
296 idx = old->conf.keyidx;
297 else
298 idx = new->conf.keyidx;
300 defunikey = old &&
301 old == key_mtx_dereference(sdata->local,
302 sdata->default_unicast_key);
303 defmultikey = old &&
304 old == key_mtx_dereference(sdata->local,
305 sdata->default_multicast_key);
306 defmgmtkey = old &&
307 old == key_mtx_dereference(sdata->local,
308 sdata->default_mgmt_key);
310 if (defunikey && !new)
311 __ieee80211_set_default_key(sdata, -1, true, false);
312 if (defmultikey && !new)
313 __ieee80211_set_default_key(sdata, -1, false, true);
314 if (defmgmtkey && !new)
315 __ieee80211_set_default_mgmt_key(sdata, -1);
317 rcu_assign_pointer(sdata->keys[idx], new);
318 if (defunikey && new)
319 __ieee80211_set_default_key(sdata, new->conf.keyidx,
320 true, false);
321 if (defmultikey && new)
322 __ieee80211_set_default_key(sdata, new->conf.keyidx,
323 false, true);
324 if (defmgmtkey && new)
325 __ieee80211_set_default_mgmt_key(sdata,
326 new->conf.keyidx);
329 if (old)
330 list_del(&old->list);
333 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
334 const u8 *key_data,
335 size_t seq_len, const u8 *seq)
337 struct ieee80211_key *key;
338 int i, j, err;
340 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
342 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
343 if (!key)
344 return ERR_PTR(-ENOMEM);
347 * Default to software encryption; we'll later upload the
348 * key to the hardware if possible.
350 key->conf.flags = 0;
351 key->flags = 0;
353 key->conf.cipher = cipher;
354 key->conf.keyidx = idx;
355 key->conf.keylen = key_len;
356 switch (cipher) {
357 case WLAN_CIPHER_SUITE_WEP40:
358 case WLAN_CIPHER_SUITE_WEP104:
359 key->conf.iv_len = WEP_IV_LEN;
360 key->conf.icv_len = WEP_ICV_LEN;
361 break;
362 case WLAN_CIPHER_SUITE_TKIP:
363 key->conf.iv_len = TKIP_IV_LEN;
364 key->conf.icv_len = TKIP_ICV_LEN;
365 if (seq) {
366 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
367 key->u.tkip.rx[i].iv32 =
368 get_unaligned_le32(&seq[2]);
369 key->u.tkip.rx[i].iv16 =
370 get_unaligned_le16(seq);
373 spin_lock_init(&key->u.tkip.txlock);
374 break;
375 case WLAN_CIPHER_SUITE_CCMP:
376 key->conf.iv_len = CCMP_HDR_LEN;
377 key->conf.icv_len = CCMP_MIC_LEN;
378 if (seq) {
379 for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
380 for (j = 0; j < CCMP_PN_LEN; j++)
381 key->u.ccmp.rx_pn[i][j] =
382 seq[CCMP_PN_LEN - j - 1];
385 * Initialize AES key state here as an optimization so that
386 * it does not need to be initialized for every packet.
388 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
389 if (IS_ERR(key->u.ccmp.tfm)) {
390 err = PTR_ERR(key->u.ccmp.tfm);
391 kfree(key);
392 return ERR_PTR(err);
394 break;
395 case WLAN_CIPHER_SUITE_AES_CMAC:
396 key->conf.iv_len = 0;
397 key->conf.icv_len = sizeof(struct ieee80211_mmie);
398 if (seq)
399 for (j = 0; j < 6; j++)
400 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
402 * Initialize AES key state here as an optimization so that
403 * it does not need to be initialized for every packet.
405 key->u.aes_cmac.tfm =
406 ieee80211_aes_cmac_key_setup(key_data);
407 if (IS_ERR(key->u.aes_cmac.tfm)) {
408 err = PTR_ERR(key->u.aes_cmac.tfm);
409 kfree(key);
410 return ERR_PTR(err);
412 break;
414 memcpy(key->conf.key, key_data, key_len);
415 INIT_LIST_HEAD(&key->list);
417 return key;
420 static void __ieee80211_key_destroy(struct ieee80211_key *key)
422 if (!key)
423 return;
426 * Synchronize so the TX path can no longer be using
427 * this key before we free/remove it.
429 synchronize_rcu();
431 if (key->local)
432 ieee80211_key_disable_hw_accel(key);
434 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
435 ieee80211_aes_key_free(key->u.ccmp.tfm);
436 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
437 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
438 if (key->local) {
439 ieee80211_debugfs_key_remove(key);
440 key->sdata->crypto_tx_tailroom_needed_cnt--;
443 kfree(key);
446 int ieee80211_key_link(struct ieee80211_key *key,
447 struct ieee80211_sub_if_data *sdata,
448 struct sta_info *sta)
450 struct ieee80211_key *old_key;
451 int idx, ret;
452 bool pairwise;
454 BUG_ON(!sdata);
455 BUG_ON(!key);
457 pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
458 idx = key->conf.keyidx;
459 key->local = sdata->local;
460 key->sdata = sdata;
461 key->sta = sta;
463 if (sta) {
465 * some hardware cannot handle TKIP with QoS, so
466 * we indicate whether QoS could be in use.
468 if (test_sta_flag(sta, WLAN_STA_WME))
469 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
470 } else {
471 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
472 struct sta_info *ap;
475 * We're getting a sta pointer in, so must be under
476 * appropriate locking for sta_info_get().
479 /* same here, the AP could be using QoS */
480 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
481 if (ap) {
482 if (test_sta_flag(ap, WLAN_STA_WME))
483 key->conf.flags |=
484 IEEE80211_KEY_FLAG_WMM_STA;
489 mutex_lock(&sdata->local->key_mtx);
491 if (sta && pairwise)
492 old_key = key_mtx_dereference(sdata->local, sta->ptk);
493 else if (sta)
494 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
495 else
496 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
498 increment_tailroom_need_count(sdata);
500 __ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
501 __ieee80211_key_destroy(old_key);
503 ieee80211_debugfs_key_add(key);
505 ret = ieee80211_key_enable_hw_accel(key);
507 mutex_unlock(&sdata->local->key_mtx);
509 return ret;
512 void __ieee80211_key_free(struct ieee80211_key *key)
514 if (!key)
515 return;
518 * Replace key with nothingness if it was ever used.
520 if (key->sdata)
521 __ieee80211_key_replace(key->sdata, key->sta,
522 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
523 key, NULL);
524 __ieee80211_key_destroy(key);
527 void ieee80211_key_free(struct ieee80211_local *local,
528 struct ieee80211_key *key)
530 mutex_lock(&local->key_mtx);
531 __ieee80211_key_free(key);
532 mutex_unlock(&local->key_mtx);
535 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
537 struct ieee80211_key *key;
539 ASSERT_RTNL();
541 if (WARN_ON(!ieee80211_sdata_running(sdata)))
542 return;
544 mutex_lock(&sdata->local->key_mtx);
546 sdata->crypto_tx_tailroom_needed_cnt = 0;
548 list_for_each_entry(key, &sdata->key_list, list) {
549 increment_tailroom_need_count(sdata);
550 ieee80211_key_enable_hw_accel(key);
553 mutex_unlock(&sdata->local->key_mtx);
556 void ieee80211_iter_keys(struct ieee80211_hw *hw,
557 struct ieee80211_vif *vif,
558 void (*iter)(struct ieee80211_hw *hw,
559 struct ieee80211_vif *vif,
560 struct ieee80211_sta *sta,
561 struct ieee80211_key_conf *key,
562 void *data),
563 void *iter_data)
565 struct ieee80211_local *local = hw_to_local(hw);
566 struct ieee80211_key *key;
567 struct ieee80211_sub_if_data *sdata;
569 ASSERT_RTNL();
571 mutex_lock(&local->key_mtx);
572 if (vif) {
573 sdata = vif_to_sdata(vif);
574 list_for_each_entry(key, &sdata->key_list, list)
575 iter(hw, &sdata->vif,
576 key->sta ? &key->sta->sta : NULL,
577 &key->conf, iter_data);
578 } else {
579 list_for_each_entry(sdata, &local->interfaces, list)
580 list_for_each_entry(key, &sdata->key_list, list)
581 iter(hw, &sdata->vif,
582 key->sta ? &key->sta->sta : NULL,
583 &key->conf, iter_data);
585 mutex_unlock(&local->key_mtx);
587 EXPORT_SYMBOL(ieee80211_iter_keys);
589 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
591 struct ieee80211_key *key;
593 ASSERT_RTNL();
595 mutex_lock(&sdata->local->key_mtx);
597 list_for_each_entry(key, &sdata->key_list, list)
598 ieee80211_key_disable_hw_accel(key);
600 mutex_unlock(&sdata->local->key_mtx);
603 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
605 struct ieee80211_key *key, *tmp;
607 mutex_lock(&sdata->local->key_mtx);
609 ieee80211_debugfs_key_remove_mgmt_default(sdata);
611 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
612 __ieee80211_key_free(key);
614 ieee80211_debugfs_key_update_default(sdata);
616 mutex_unlock(&sdata->local->key_mtx);
620 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
621 const u8 *replay_ctr, gfp_t gfp)
623 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
625 trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
627 cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
629 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
631 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
632 struct ieee80211_key_seq *seq)
634 struct ieee80211_key *key;
635 u64 pn64;
637 if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
638 return;
640 key = container_of(keyconf, struct ieee80211_key, conf);
642 switch (key->conf.cipher) {
643 case WLAN_CIPHER_SUITE_TKIP:
644 seq->tkip.iv32 = key->u.tkip.tx.iv32;
645 seq->tkip.iv16 = key->u.tkip.tx.iv16;
646 break;
647 case WLAN_CIPHER_SUITE_CCMP:
648 pn64 = atomic64_read(&key->u.ccmp.tx_pn);
649 seq->ccmp.pn[5] = pn64;
650 seq->ccmp.pn[4] = pn64 >> 8;
651 seq->ccmp.pn[3] = pn64 >> 16;
652 seq->ccmp.pn[2] = pn64 >> 24;
653 seq->ccmp.pn[1] = pn64 >> 32;
654 seq->ccmp.pn[0] = pn64 >> 40;
655 break;
656 case WLAN_CIPHER_SUITE_AES_CMAC:
657 pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
658 seq->ccmp.pn[5] = pn64;
659 seq->ccmp.pn[4] = pn64 >> 8;
660 seq->ccmp.pn[3] = pn64 >> 16;
661 seq->ccmp.pn[2] = pn64 >> 24;
662 seq->ccmp.pn[1] = pn64 >> 32;
663 seq->ccmp.pn[0] = pn64 >> 40;
664 break;
665 default:
666 WARN_ON(1);
669 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
671 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
672 int tid, struct ieee80211_key_seq *seq)
674 struct ieee80211_key *key;
675 const u8 *pn;
677 key = container_of(keyconf, struct ieee80211_key, conf);
679 switch (key->conf.cipher) {
680 case WLAN_CIPHER_SUITE_TKIP:
681 if (WARN_ON(tid < 0 || tid >= NUM_RX_DATA_QUEUES))
682 return;
683 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
684 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
685 break;
686 case WLAN_CIPHER_SUITE_CCMP:
687 if (WARN_ON(tid < -1 || tid >= NUM_RX_DATA_QUEUES))
688 return;
689 if (tid < 0)
690 pn = key->u.ccmp.rx_pn[NUM_RX_DATA_QUEUES];
691 else
692 pn = key->u.ccmp.rx_pn[tid];
693 memcpy(seq->ccmp.pn, pn, CCMP_PN_LEN);
694 break;
695 case WLAN_CIPHER_SUITE_AES_CMAC:
696 if (WARN_ON(tid != 0))
697 return;
698 pn = key->u.aes_cmac.rx_pn;
699 memcpy(seq->aes_cmac.pn, pn, CMAC_PN_LEN);
700 break;
703 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);