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 wiphy_err(key->local->hw.wiphy,
91 "failed to set key (%d, %pM) to hardware (%d)\n",
92 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
95 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
97 struct ieee80211_sub_if_data *sdata;
98 struct ieee80211_sta *sta;
103 if (!key || !key->local->ops->set_key)
106 assert_key_lock(key->local);
108 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
111 sta = get_sta_for_key(key);
114 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
115 sdata = container_of(sdata->bss,
116 struct ieee80211_sub_if_data,
119 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
123 wiphy_err(key->local->hw.wiphy,
124 "failed to remove key (%d, %pM) from hardware (%d)\n",
125 key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
127 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
130 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
133 struct ieee80211_key *key = NULL;
135 assert_key_lock(sdata->local);
137 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
138 key = sdata->keys[idx];
140 rcu_assign_pointer(sdata->default_key, key);
143 ieee80211_debugfs_key_remove_default(key->sdata);
144 ieee80211_debugfs_key_add_default(key->sdata);
148 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
150 mutex_lock(&sdata->local->key_mtx);
151 __ieee80211_set_default_key(sdata, idx);
152 mutex_unlock(&sdata->local->key_mtx);
156 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
158 struct ieee80211_key *key = NULL;
160 assert_key_lock(sdata->local);
162 if (idx >= NUM_DEFAULT_KEYS &&
163 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
164 key = sdata->keys[idx];
166 rcu_assign_pointer(sdata->default_mgmt_key, key);
169 ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
170 ieee80211_debugfs_key_add_mgmt_default(key->sdata);
174 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
177 mutex_lock(&sdata->local->key_mtx);
178 __ieee80211_set_default_mgmt_key(sdata, idx);
179 mutex_unlock(&sdata->local->key_mtx);
183 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
184 struct sta_info *sta,
185 struct ieee80211_key *old,
186 struct ieee80211_key *new)
188 int idx, defkey, defmgmtkey;
191 list_add(&new->list, &sdata->key_list);
194 rcu_assign_pointer(sta->key, new);
196 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
199 idx = old->conf.keyidx;
201 idx = new->conf.keyidx;
203 defkey = old && sdata->default_key == old;
204 defmgmtkey = old && sdata->default_mgmt_key == old;
207 __ieee80211_set_default_key(sdata, -1);
208 if (defmgmtkey && !new)
209 __ieee80211_set_default_mgmt_key(sdata, -1);
211 rcu_assign_pointer(sdata->keys[idx], new);
213 __ieee80211_set_default_key(sdata, new->conf.keyidx);
214 if (defmgmtkey && new)
215 __ieee80211_set_default_mgmt_key(sdata,
221 * We'll use an empty list to indicate that the key
222 * has already been removed.
224 list_del_init(&old->list);
228 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
230 size_t seq_len, const u8 *seq)
232 struct ieee80211_key *key;
235 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
237 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
239 return ERR_PTR(-ENOMEM);
242 * Default to software encryption; we'll later upload the
243 * key to the hardware if possible.
248 key->conf.cipher = cipher;
249 key->conf.keyidx = idx;
250 key->conf.keylen = key_len;
252 case WLAN_CIPHER_SUITE_WEP40:
253 case WLAN_CIPHER_SUITE_WEP104:
254 key->conf.iv_len = WEP_IV_LEN;
255 key->conf.icv_len = WEP_ICV_LEN;
257 case WLAN_CIPHER_SUITE_TKIP:
258 key->conf.iv_len = TKIP_IV_LEN;
259 key->conf.icv_len = TKIP_ICV_LEN;
261 for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
262 key->u.tkip.rx[i].iv32 =
263 get_unaligned_le32(&seq[2]);
264 key->u.tkip.rx[i].iv16 =
265 get_unaligned_le16(seq);
269 case WLAN_CIPHER_SUITE_CCMP:
270 key->conf.iv_len = CCMP_HDR_LEN;
271 key->conf.icv_len = CCMP_MIC_LEN;
273 for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
274 for (j = 0; j < CCMP_PN_LEN; j++)
275 key->u.ccmp.rx_pn[i][j] =
276 seq[CCMP_PN_LEN - j - 1];
279 * Initialize AES key state here as an optimization so that
280 * it does not need to be initialized for every packet.
282 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
283 if (IS_ERR(key->u.ccmp.tfm)) {
284 err = PTR_ERR(key->u.ccmp.tfm);
289 case WLAN_CIPHER_SUITE_AES_CMAC:
290 key->conf.iv_len = 0;
291 key->conf.icv_len = sizeof(struct ieee80211_mmie);
293 for (j = 0; j < 6; j++)
294 key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
296 * Initialize AES key state here as an optimization so that
297 * it does not need to be initialized for every packet.
299 key->u.aes_cmac.tfm =
300 ieee80211_aes_cmac_key_setup(key_data);
301 if (IS_ERR(key->u.aes_cmac.tfm)) {
302 err = PTR_ERR(key->u.aes_cmac.tfm);
308 memcpy(key->conf.key, key_data, key_len);
309 INIT_LIST_HEAD(&key->list);
314 static void __ieee80211_key_destroy(struct ieee80211_key *key)
320 ieee80211_key_disable_hw_accel(key);
322 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
323 ieee80211_aes_key_free(key->u.ccmp.tfm);
324 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
325 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
327 ieee80211_debugfs_key_remove(key);
332 void ieee80211_key_link(struct ieee80211_key *key,
333 struct ieee80211_sub_if_data *sdata,
334 struct sta_info *sta)
336 struct ieee80211_key *old_key;
342 idx = key->conf.keyidx;
343 key->local = sdata->local;
349 * some hardware cannot handle TKIP with QoS, so
350 * we indicate whether QoS could be in use.
352 if (test_sta_flags(sta, WLAN_STA_WME))
353 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
356 * This key is for a specific sta interface,
357 * inform the driver that it should try to store
358 * this key as pairwise key.
360 key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
362 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
366 * We're getting a sta pointer in,
367 * so must be under RCU read lock.
370 /* same here, the AP could be using QoS */
371 ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
373 if (test_sta_flags(ap, WLAN_STA_WME))
375 IEEE80211_KEY_FLAG_WMM_STA;
380 mutex_lock(&sdata->local->key_mtx);
385 old_key = sdata->keys[idx];
387 __ieee80211_key_replace(sdata, sta, old_key, key);
388 __ieee80211_key_destroy(old_key);
390 ieee80211_debugfs_key_add(key);
392 ieee80211_key_enable_hw_accel(key);
394 mutex_unlock(&sdata->local->key_mtx);
397 static void __ieee80211_key_free(struct ieee80211_key *key)
400 * Replace key with nothingness if it was ever used.
403 __ieee80211_key_replace(key->sdata, key->sta,
405 __ieee80211_key_destroy(key);
408 void ieee80211_key_free(struct ieee80211_local *local,
409 struct ieee80211_key *key)
414 mutex_lock(&local->key_mtx);
415 __ieee80211_key_free(key);
416 mutex_unlock(&local->key_mtx);
419 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
421 struct ieee80211_key *key;
425 if (WARN_ON(!ieee80211_sdata_running(sdata)))
428 mutex_lock(&sdata->local->key_mtx);
430 list_for_each_entry(key, &sdata->key_list, list)
431 ieee80211_key_enable_hw_accel(key);
433 mutex_unlock(&sdata->local->key_mtx);
436 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
438 struct ieee80211_key *key;
442 mutex_lock(&sdata->local->key_mtx);
444 list_for_each_entry(key, &sdata->key_list, list)
445 ieee80211_key_disable_hw_accel(key);
447 mutex_unlock(&sdata->local->key_mtx);
450 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
452 struct ieee80211_key *key, *tmp;
454 mutex_lock(&sdata->local->key_mtx);
456 ieee80211_debugfs_key_remove_default(sdata);
457 ieee80211_debugfs_key_remove_mgmt_default(sdata);
459 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
460 __ieee80211_key_free(key);
462 mutex_unlock(&sdata->local->key_mtx);