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"
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
39 * All key operations are protected internally.
41 * Within mac80211, key references are, just as STA structure references,
42 * protected by RCU. Note, however, that some things are unprotected,
43 * namely the key->sta dereferences within the hardware acceleration
44 * functions. This means that sta_info_destroy() must remove the key
45 * which waits for an RCU grace period.
48 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
50 static void assert_key_lock(struct ieee80211_local *local)
52 lockdep_assert_held(&local->key_mtx);
55 static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
58 return &key->sta->sta;
63 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
65 struct ieee80211_sub_if_data *sdata;
66 struct ieee80211_sta *sta;
71 if (!key->local->ops->set_key)
74 assert_key_lock(key->local);
76 sta = get_sta_for_key(key);
79 * If this is a per-STA GTK, check if it
80 * is supported; if not, return.
82 if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
83 !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
87 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
89 * The driver doesn't know anything about VLAN interfaces.
90 * Hence, don't send GTKs for VLAN interfaces to the driver.
92 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
94 sdata = container_of(sdata->bss,
95 struct ieee80211_sub_if_data,
99 ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
102 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
106 if (ret != -ENOSPC && ret != -EOPNOTSUPP)
107 wiphy_err(key->local->hw.wiphy,
108 "failed to set key (%d, %pM) to hardware (%d)\n",
109 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
112 switch (key->conf.cipher) {
113 case WLAN_CIPHER_SUITE_WEP40:
114 case WLAN_CIPHER_SUITE_WEP104:
115 case WLAN_CIPHER_SUITE_TKIP:
116 case WLAN_CIPHER_SUITE_CCMP:
117 case WLAN_CIPHER_SUITE_AES_CMAC:
118 /* all of these we can do in software */
125 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
127 struct ieee80211_sub_if_data *sdata;
128 struct ieee80211_sta *sta;
133 if (!key || !key->local->ops->set_key)
136 assert_key_lock(key->local);
138 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
141 sta = get_sta_for_key(key);
144 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
145 sdata = container_of(sdata->bss,
146 struct ieee80211_sub_if_data,
149 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
153 wiphy_err(key->local->hw.wiphy,
154 "failed to remove key (%d, %pM) from hardware (%d)\n",
155 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
157 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
160 void ieee80211_key_removed(struct ieee80211_key_conf *key_conf)
162 struct ieee80211_key *key;
164 key = container_of(key_conf, struct ieee80211_key, conf);
167 assert_key_lock(key->local);
169 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
172 * Flush TX path to avoid attempts to use this key
173 * after this function returns. Until then, drivers
174 * must be prepared to handle the key.
178 EXPORT_SYMBOL_GPL(ieee80211_key_removed);
180 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
181 int idx, bool uni, bool multi)
183 struct ieee80211_key *key = NULL;
185 assert_key_lock(sdata->local);
187 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
188 key = sdata->keys[idx];
191 rcu_assign_pointer(sdata->default_unicast_key, key);
193 rcu_assign_pointer(sdata->default_multicast_key, key);
195 ieee80211_debugfs_key_update_default(sdata);
198 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
199 bool uni, bool multi)
201 mutex_lock(&sdata->local->key_mtx);
202 __ieee80211_set_default_key(sdata, idx, uni, multi);
203 mutex_unlock(&sdata->local->key_mtx);
207 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
209 struct ieee80211_key *key = NULL;
211 assert_key_lock(sdata->local);
213 if (idx >= NUM_DEFAULT_KEYS &&
214 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
215 key = sdata->keys[idx];
217 rcu_assign_pointer(sdata->default_mgmt_key, key);
219 ieee80211_debugfs_key_update_default(sdata);
222 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
225 mutex_lock(&sdata->local->key_mtx);
226 __ieee80211_set_default_mgmt_key(sdata, idx);
227 mutex_unlock(&sdata->local->key_mtx);
231 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
232 struct sta_info *sta,
234 struct ieee80211_key *old,
235 struct ieee80211_key *new)
238 bool defunikey, defmultikey, defmgmtkey;
241 list_add(&new->list, &sdata->key_list);
243 if (sta && pairwise) {
244 rcu_assign_pointer(sta->ptk, new);
247 idx = old->conf.keyidx;
249 idx = new->conf.keyidx;
250 rcu_assign_pointer(sta->gtk[idx], new);
252 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
255 idx = old->conf.keyidx;
257 idx = new->conf.keyidx;
259 defunikey = old && sdata->default_unicast_key == old;
260 defmultikey = old && sdata->default_multicast_key == old;
261 defmgmtkey = old && sdata->default_mgmt_key == old;
263 if (defunikey && !new)
264 __ieee80211_set_default_key(sdata, -1, true, false);
265 if (defmultikey && !new)
266 __ieee80211_set_default_key(sdata, -1, false, true);
267 if (defmgmtkey && !new)
268 __ieee80211_set_default_mgmt_key(sdata, -1);
270 rcu_assign_pointer(sdata->keys[idx], new);
271 if (defunikey && new)
272 __ieee80211_set_default_key(sdata, new->conf.keyidx,
274 if (defmultikey && new)
275 __ieee80211_set_default_key(sdata, new->conf.keyidx,
277 if (defmgmtkey && new)
278 __ieee80211_set_default_mgmt_key(sdata,
284 * We'll use an empty list to indicate that the key
285 * has already been removed.
287 list_del_init(&old->list);
291 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
293 size_t seq_len, const u8 *seq)
295 struct ieee80211_key *key;
298 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
300 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
302 return ERR_PTR(-ENOMEM);
305 * Default to software encryption; we'll later upload the
306 * key to the hardware if possible.
311 key->conf.cipher = cipher;
312 key->conf.keyidx = idx;
313 key->conf.keylen = key_len;
315 case WLAN_CIPHER_SUITE_WEP40:
316 case WLAN_CIPHER_SUITE_WEP104:
317 key->conf.iv_len = WEP_IV_LEN;
318 key->conf.icv_len = WEP_ICV_LEN;
320 case WLAN_CIPHER_SUITE_TKIP:
321 key->conf.iv_len = TKIP_IV_LEN;
322 key->conf.icv_len = TKIP_ICV_LEN;
324 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
325 key->u.tkip.rx[i].iv32 =
326 get_unaligned_le32(&seq[2]);
327 key->u.tkip.rx[i].iv16 =
328 get_unaligned_le16(seq);
332 case WLAN_CIPHER_SUITE_CCMP:
333 key->conf.iv_len = CCMP_HDR_LEN;
334 key->conf.icv_len = CCMP_MIC_LEN;
336 for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
337 for (j = 0; j < CCMP_PN_LEN; j++)
338 key->u.ccmp.rx_pn[i][j] =
339 seq[CCMP_PN_LEN - j - 1];
342 * Initialize AES key state here as an optimization so that
343 * it does not need to be initialized for every packet.
345 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
346 if (IS_ERR(key->u.ccmp.tfm)) {
347 err = PTR_ERR(key->u.ccmp.tfm);
352 case WLAN_CIPHER_SUITE_AES_CMAC:
353 key->conf.iv_len = 0;
354 key->conf.icv_len = sizeof(struct ieee80211_mmie);
356 for (j = 0; j < 6; j++)
357 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
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.aes_cmac.tfm =
363 ieee80211_aes_cmac_key_setup(key_data);
364 if (IS_ERR(key->u.aes_cmac.tfm)) {
365 err = PTR_ERR(key->u.aes_cmac.tfm);
371 memcpy(key->conf.key, key_data, key_len);
372 INIT_LIST_HEAD(&key->list);
377 static void __ieee80211_key_destroy(struct ieee80211_key *key)
383 ieee80211_key_disable_hw_accel(key);
385 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
386 ieee80211_aes_key_free(key->u.ccmp.tfm);
387 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
388 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
390 ieee80211_debugfs_key_remove(key);
395 int ieee80211_key_link(struct ieee80211_key *key,
396 struct ieee80211_sub_if_data *sdata,
397 struct sta_info *sta)
399 struct ieee80211_key *old_key;
401 bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
406 idx = key->conf.keyidx;
407 key->local = sdata->local;
413 * some hardware cannot handle TKIP with QoS, so
414 * we indicate whether QoS could be in use.
416 if (test_sta_flags(sta, WLAN_STA_WME))
417 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
419 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
423 * We're getting a sta pointer in,
424 * so must be under RCU read lock.
427 /* same here, the AP could be using QoS */
428 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
430 if (test_sta_flags(ap, WLAN_STA_WME))
432 IEEE80211_KEY_FLAG_WMM_STA;
437 mutex_lock(&sdata->local->key_mtx);
442 old_key = sta->gtk[idx];
444 old_key = sdata->keys[idx];
446 __ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
447 __ieee80211_key_destroy(old_key);
449 ieee80211_debugfs_key_add(key);
451 ret = ieee80211_key_enable_hw_accel(key);
453 mutex_unlock(&sdata->local->key_mtx);
458 static void __ieee80211_key_free(struct ieee80211_key *key)
461 * Replace key with nothingness if it was ever used.
464 __ieee80211_key_replace(key->sdata, key->sta,
465 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
467 __ieee80211_key_destroy(key);
470 void ieee80211_key_free(struct ieee80211_local *local,
471 struct ieee80211_key *key)
476 mutex_lock(&local->key_mtx);
477 __ieee80211_key_free(key);
478 mutex_unlock(&local->key_mtx);
481 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
483 struct ieee80211_key *key;
487 if (WARN_ON(!ieee80211_sdata_running(sdata)))
490 mutex_lock(&sdata->local->key_mtx);
492 list_for_each_entry(key, &sdata->key_list, list)
493 ieee80211_key_enable_hw_accel(key);
495 mutex_unlock(&sdata->local->key_mtx);
498 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
500 struct ieee80211_key *key;
504 mutex_lock(&sdata->local->key_mtx);
506 list_for_each_entry(key, &sdata->key_list, list)
507 ieee80211_key_disable_hw_accel(key);
509 mutex_unlock(&sdata->local->key_mtx);
512 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
514 struct ieee80211_key *key, *tmp;
516 mutex_lock(&sdata->local->key_mtx);
518 ieee80211_debugfs_key_remove_mgmt_default(sdata);
520 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
521 __ieee80211_key_free(key);
523 ieee80211_debugfs_key_update_default(sdata);
525 mutex_unlock(&sdata->local->key_mtx);