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 WARN_ON(!mutex_is_locked(&local->key_mtx));
55 static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
58 return &key->sta->sta;
63 static void 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 (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
80 sdata = container_of(sdata->bss,
81 struct ieee80211_sub_if_data,
84 ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
87 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
89 if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
90 printk(KERN_ERR "mac80211-%s: failed to set key "
91 "(%d, %pM) to hardware (%d)\n",
92 wiphy_name(key->local->hw.wiphy),
93 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
96 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
98 struct ieee80211_sub_if_data *sdata;
99 struct ieee80211_sta *sta;
104 if (!key || !key->local->ops->set_key)
107 assert_key_lock(key->local);
109 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
112 sta = get_sta_for_key(key);
115 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
116 sdata = container_of(sdata->bss,
117 struct ieee80211_sub_if_data,
120 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
124 printk(KERN_ERR "mac80211-%s: failed to remove key "
125 "(%d, %pM) from hardware (%d)\n",
126 wiphy_name(key->local->hw.wiphy),
127 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
129 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
132 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
135 struct ieee80211_key *key = NULL;
137 assert_key_lock(sdata->local);
139 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
140 key = sdata->keys[idx];
142 rcu_assign_pointer(sdata->default_key, key);
145 ieee80211_debugfs_key_remove_default(key->sdata);
146 ieee80211_debugfs_key_add_default(key->sdata);
150 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
152 mutex_lock(&sdata->local->key_mtx);
153 __ieee80211_set_default_key(sdata, idx);
154 mutex_unlock(&sdata->local->key_mtx);
158 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
160 struct ieee80211_key *key = NULL;
162 assert_key_lock(sdata->local);
164 if (idx >= NUM_DEFAULT_KEYS &&
165 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
166 key = sdata->keys[idx];
168 rcu_assign_pointer(sdata->default_mgmt_key, key);
171 ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
172 ieee80211_debugfs_key_add_mgmt_default(key->sdata);
176 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
179 mutex_lock(&sdata->local->key_mtx);
180 __ieee80211_set_default_mgmt_key(sdata, idx);
181 mutex_unlock(&sdata->local->key_mtx);
185 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
186 struct sta_info *sta,
187 struct ieee80211_key *old,
188 struct ieee80211_key *new)
190 int idx, defkey, defmgmtkey;
193 list_add(&new->list, &sdata->key_list);
196 rcu_assign_pointer(sta->key, new);
198 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
201 idx = old->conf.keyidx;
203 idx = new->conf.keyidx;
205 defkey = old && sdata->default_key == old;
206 defmgmtkey = old && sdata->default_mgmt_key == old;
209 __ieee80211_set_default_key(sdata, -1);
210 if (defmgmtkey && !new)
211 __ieee80211_set_default_mgmt_key(sdata, -1);
213 rcu_assign_pointer(sdata->keys[idx], new);
215 __ieee80211_set_default_key(sdata, new->conf.keyidx);
216 if (defmgmtkey && new)
217 __ieee80211_set_default_mgmt_key(sdata,
223 * We'll use an empty list to indicate that the key
224 * has already been removed.
226 list_del_init(&old->list);
230 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
232 size_t seq_len, const u8 *seq)
234 struct ieee80211_key *key;
237 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
239 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
241 return ERR_PTR(-ENOMEM);
244 * Default to software encryption; we'll later upload the
245 * key to the hardware if possible.
250 key->conf.cipher = cipher;
251 key->conf.keyidx = idx;
252 key->conf.keylen = key_len;
254 case WLAN_CIPHER_SUITE_WEP40:
255 case WLAN_CIPHER_SUITE_WEP104:
256 key->conf.iv_len = WEP_IV_LEN;
257 key->conf.icv_len = WEP_ICV_LEN;
259 case WLAN_CIPHER_SUITE_TKIP:
260 key->conf.iv_len = TKIP_IV_LEN;
261 key->conf.icv_len = TKIP_ICV_LEN;
263 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
264 key->u.tkip.rx[i].iv32 =
265 get_unaligned_le32(&seq[2]);
266 key->u.tkip.rx[i].iv16 =
267 get_unaligned_le16(seq);
271 case WLAN_CIPHER_SUITE_CCMP:
272 key->conf.iv_len = CCMP_HDR_LEN;
273 key->conf.icv_len = CCMP_MIC_LEN;
275 for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
276 for (j = 0; j < CCMP_PN_LEN; j++)
277 key->u.ccmp.rx_pn[i][j] =
278 seq[CCMP_PN_LEN - j - 1];
281 * Initialize AES key state here as an optimization so that
282 * it does not need to be initialized for every packet.
284 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
285 if (IS_ERR(key->u.ccmp.tfm)) {
286 err = PTR_ERR(key->u.ccmp.tfm);
291 case WLAN_CIPHER_SUITE_AES_CMAC:
292 key->conf.iv_len = 0;
293 key->conf.icv_len = sizeof(struct ieee80211_mmie);
295 for (j = 0; j < 6; j++)
296 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
298 * Initialize AES key state here as an optimization so that
299 * it does not need to be initialized for every packet.
301 key->u.aes_cmac.tfm =
302 ieee80211_aes_cmac_key_setup(key_data);
303 if (IS_ERR(key->u.aes_cmac.tfm)) {
304 err = PTR_ERR(key->u.aes_cmac.tfm);
310 memcpy(key->conf.key, key_data, key_len);
311 INIT_LIST_HEAD(&key->list);
316 static void __ieee80211_key_destroy(struct ieee80211_key *key)
322 ieee80211_key_disable_hw_accel(key);
324 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
325 ieee80211_aes_key_free(key->u.ccmp.tfm);
326 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
327 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
329 ieee80211_debugfs_key_remove(key);
334 void ieee80211_key_link(struct ieee80211_key *key,
335 struct ieee80211_sub_if_data *sdata,
336 struct sta_info *sta)
338 struct ieee80211_key *old_key;
344 idx = key->conf.keyidx;
345 key->local = sdata->local;
351 * some hardware cannot handle TKIP with QoS, so
352 * we indicate whether QoS could be in use.
354 if (test_sta_flags(sta, WLAN_STA_WME))
355 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
358 * This key is for a specific sta interface,
359 * inform the driver that it should try to store
360 * this key as pairwise key.
362 key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
364 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
368 * We're getting a sta pointer in,
369 * so must be under RCU read lock.
372 /* same here, the AP could be using QoS */
373 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
375 if (test_sta_flags(ap, WLAN_STA_WME))
377 IEEE80211_KEY_FLAG_WMM_STA;
382 mutex_lock(&sdata->local->key_mtx);
387 old_key = sdata->keys[idx];
389 __ieee80211_key_replace(sdata, sta, old_key, key);
390 __ieee80211_key_destroy(old_key);
392 ieee80211_debugfs_key_add(key);
394 ieee80211_key_enable_hw_accel(key);
396 mutex_unlock(&sdata->local->key_mtx);
399 static void __ieee80211_key_free(struct ieee80211_key *key)
402 * Replace key with nothingness if it was ever used.
405 __ieee80211_key_replace(key->sdata, key->sta,
407 __ieee80211_key_destroy(key);
410 void ieee80211_key_free(struct ieee80211_local *local,
411 struct ieee80211_key *key)
416 mutex_lock(&local->key_mtx);
417 __ieee80211_key_free(key);
418 mutex_unlock(&local->key_mtx);
421 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
423 struct ieee80211_key *key;
427 if (WARN_ON(!ieee80211_sdata_running(sdata)))
430 mutex_lock(&sdata->local->key_mtx);
432 list_for_each_entry(key, &sdata->key_list, list)
433 ieee80211_key_enable_hw_accel(key);
435 mutex_unlock(&sdata->local->key_mtx);
438 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
440 struct ieee80211_key *key;
444 mutex_lock(&sdata->local->key_mtx);
446 list_for_each_entry(key, &sdata->key_list, list)
447 ieee80211_key_disable_hw_accel(key);
449 mutex_unlock(&sdata->local->key_mtx);
452 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
454 struct ieee80211_key *key, *tmp;
456 mutex_lock(&sdata->local->key_mtx);
458 ieee80211_debugfs_key_remove_default(sdata);
459 ieee80211_debugfs_key_remove_mgmt_default(sdata);
461 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
462 __ieee80211_key_free(key);
464 mutex_unlock(&sdata->local->key_mtx);