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,
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];
190 rcu_assign_pointer(sdata->default_key, key);
193 ieee80211_debugfs_key_remove_default(key->sdata);
194 ieee80211_debugfs_key_add_default(key->sdata);
198 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
200 mutex_lock(&sdata->local->key_mtx);
201 __ieee80211_set_default_key(sdata, idx);
202 mutex_unlock(&sdata->local->key_mtx);
206 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
208 struct ieee80211_key *key = NULL;
210 assert_key_lock(sdata->local);
212 if (idx >= NUM_DEFAULT_KEYS &&
213 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
214 key = sdata->keys[idx];
216 rcu_assign_pointer(sdata->default_mgmt_key, key);
219 ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
220 ieee80211_debugfs_key_add_mgmt_default(key->sdata);
224 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
227 mutex_lock(&sdata->local->key_mtx);
228 __ieee80211_set_default_mgmt_key(sdata, idx);
229 mutex_unlock(&sdata->local->key_mtx);
233 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
234 struct sta_info *sta,
236 struct ieee80211_key *old,
237 struct ieee80211_key *new)
239 int idx, defkey, defmgmtkey;
242 list_add(&new->list, &sdata->key_list);
244 if (sta && pairwise) {
245 rcu_assign_pointer(sta->ptk, new);
248 idx = old->conf.keyidx;
250 idx = new->conf.keyidx;
251 rcu_assign_pointer(sta->gtk[idx], new);
253 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
256 idx = old->conf.keyidx;
258 idx = new->conf.keyidx;
260 defkey = old && sdata->default_key == old;
261 defmgmtkey = old && sdata->default_mgmt_key == old;
264 __ieee80211_set_default_key(sdata, -1);
265 if (defmgmtkey && !new)
266 __ieee80211_set_default_mgmt_key(sdata, -1);
268 rcu_assign_pointer(sdata->keys[idx], new);
270 __ieee80211_set_default_key(sdata, new->conf.keyidx);
271 if (defmgmtkey && new)
272 __ieee80211_set_default_mgmt_key(sdata,
278 * We'll use an empty list to indicate that the key
279 * has already been removed.
281 list_del_init(&old->list);
285 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
287 size_t seq_len, const u8 *seq)
289 struct ieee80211_key *key;
292 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
294 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
296 return ERR_PTR(-ENOMEM);
299 * Default to software encryption; we'll later upload the
300 * key to the hardware if possible.
305 key->conf.cipher = cipher;
306 key->conf.keyidx = idx;
307 key->conf.keylen = key_len;
309 case WLAN_CIPHER_SUITE_WEP40:
310 case WLAN_CIPHER_SUITE_WEP104:
311 key->conf.iv_len = WEP_IV_LEN;
312 key->conf.icv_len = WEP_ICV_LEN;
314 case WLAN_CIPHER_SUITE_TKIP:
315 key->conf.iv_len = TKIP_IV_LEN;
316 key->conf.icv_len = TKIP_ICV_LEN;
318 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
319 key->u.tkip.rx[i].iv32 =
320 get_unaligned_le32(&seq[2]);
321 key->u.tkip.rx[i].iv16 =
322 get_unaligned_le16(seq);
326 case WLAN_CIPHER_SUITE_CCMP:
327 key->conf.iv_len = CCMP_HDR_LEN;
328 key->conf.icv_len = CCMP_MIC_LEN;
330 for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
331 for (j = 0; j < CCMP_PN_LEN; j++)
332 key->u.ccmp.rx_pn[i][j] =
333 seq[CCMP_PN_LEN - j - 1];
336 * Initialize AES key state here as an optimization so that
337 * it does not need to be initialized for every packet.
339 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
340 if (IS_ERR(key->u.ccmp.tfm)) {
341 err = PTR_ERR(key->u.ccmp.tfm);
346 case WLAN_CIPHER_SUITE_AES_CMAC:
347 key->conf.iv_len = 0;
348 key->conf.icv_len = sizeof(struct ieee80211_mmie);
350 for (j = 0; j < 6; j++)
351 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
353 * Initialize AES key state here as an optimization so that
354 * it does not need to be initialized for every packet.
356 key->u.aes_cmac.tfm =
357 ieee80211_aes_cmac_key_setup(key_data);
358 if (IS_ERR(key->u.aes_cmac.tfm)) {
359 err = PTR_ERR(key->u.aes_cmac.tfm);
365 memcpy(key->conf.key, key_data, key_len);
366 INIT_LIST_HEAD(&key->list);
371 static void __ieee80211_key_destroy(struct ieee80211_key *key)
377 ieee80211_key_disable_hw_accel(key);
379 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
380 ieee80211_aes_key_free(key->u.ccmp.tfm);
381 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
382 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
384 ieee80211_debugfs_key_remove(key);
389 int ieee80211_key_link(struct ieee80211_key *key,
390 struct ieee80211_sub_if_data *sdata,
391 struct sta_info *sta)
393 struct ieee80211_key *old_key;
395 bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
400 idx = key->conf.keyidx;
401 key->local = sdata->local;
407 * some hardware cannot handle TKIP with QoS, so
408 * we indicate whether QoS could be in use.
410 if (test_sta_flags(sta, WLAN_STA_WME))
411 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
413 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
417 * We're getting a sta pointer in,
418 * so must be under RCU read lock.
421 /* same here, the AP could be using QoS */
422 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
424 if (test_sta_flags(ap, WLAN_STA_WME))
426 IEEE80211_KEY_FLAG_WMM_STA;
431 mutex_lock(&sdata->local->key_mtx);
436 old_key = sta->gtk[idx];
438 old_key = sdata->keys[idx];
440 __ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
441 __ieee80211_key_destroy(old_key);
443 ieee80211_debugfs_key_add(key);
445 ret = ieee80211_key_enable_hw_accel(key);
447 mutex_unlock(&sdata->local->key_mtx);
452 static void __ieee80211_key_free(struct ieee80211_key *key)
455 * Replace key with nothingness if it was ever used.
458 __ieee80211_key_replace(key->sdata, key->sta,
459 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
461 __ieee80211_key_destroy(key);
464 void ieee80211_key_free(struct ieee80211_local *local,
465 struct ieee80211_key *key)
470 mutex_lock(&local->key_mtx);
471 __ieee80211_key_free(key);
472 mutex_unlock(&local->key_mtx);
475 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
477 struct ieee80211_key *key;
481 if (WARN_ON(!ieee80211_sdata_running(sdata)))
484 mutex_lock(&sdata->local->key_mtx);
486 list_for_each_entry(key, &sdata->key_list, list)
487 ieee80211_key_enable_hw_accel(key);
489 mutex_unlock(&sdata->local->key_mtx);
492 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
494 struct ieee80211_key *key;
498 mutex_lock(&sdata->local->key_mtx);
500 list_for_each_entry(key, &sdata->key_list, list)
501 ieee80211_key_disable_hw_accel(key);
503 mutex_unlock(&sdata->local->key_mtx);
506 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
508 struct ieee80211_key *key, *tmp;
510 mutex_lock(&sdata->local->key_mtx);
512 ieee80211_debugfs_key_remove_default(sdata);
513 ieee80211_debugfs_key_remove_mgmt_default(sdata);
515 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
516 __ieee80211_key_free(key);
518 mutex_unlock(&sdata->local->key_mtx);