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1f5a7e47 JB |
1 | /* |
2 | * Copyright 2002-2005, Instant802 Networks, Inc. | |
3 | * Copyright 2005-2006, Devicescape Software, Inc. | |
4 | * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> | |
11a843b7 | 5 | * Copyright 2007 Johannes Berg <johannes@sipsolutions.net> |
1f5a7e47 JB |
6 | * |
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. | |
10 | */ | |
11 | ||
11a843b7 JB |
12 | #include <linux/if_ether.h> |
13 | #include <linux/etherdevice.h> | |
14 | #include <linux/list.h> | |
d4e46a3d | 15 | #include <linux/rcupdate.h> |
db4d1169 | 16 | #include <linux/rtnetlink.h> |
1f5a7e47 JB |
17 | #include <net/mac80211.h> |
18 | #include "ieee80211_i.h" | |
19 | #include "debugfs_key.h" | |
20 | #include "aes_ccm.h" | |
21 | ||
11a843b7 JB |
22 | |
23 | /* | |
24 | * Key handling basics | |
25 | * | |
26 | * Key handling in mac80211 is done based on per-interface (sub_if_data) | |
27 | * keys and per-station keys. Since each station belongs to an interface, | |
28 | * each station key also belongs to that interface. | |
29 | * | |
30 | * Hardware acceleration is done on a best-effort basis, for each key | |
31 | * that is eligible the hardware is asked to enable that key but if | |
32 | * it cannot do that they key is simply kept for software encryption. | |
33 | * There is currently no way of knowing this except by looking into | |
34 | * debugfs. | |
35 | * | |
36 | * All operations here are called under RTNL so no extra locking is | |
37 | * required. | |
db4d1169 JB |
38 | * |
39 | * NOTE: This code requires that sta info *destruction* is done under | |
40 | * RTNL, otherwise it can try to access already freed STA structs | |
41 | * when a STA key is being freed. | |
11a843b7 JB |
42 | */ |
43 | ||
44 | static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; | |
45 | static const u8 zero_addr[ETH_ALEN]; | |
46 | ||
47 | static const u8 *get_mac_for_key(struct ieee80211_key *key) | |
48 | { | |
49 | const u8 *addr = bcast_addr; | |
50 | ||
51 | /* | |
52 | * If we're an AP we won't ever receive frames with a non-WEP | |
53 | * group key so we tell the driver that by using the zero MAC | |
54 | * address to indicate a transmit-only key. | |
55 | */ | |
56 | if (key->conf.alg != ALG_WEP && | |
51fb61e7 JB |
57 | (key->sdata->vif.type == IEEE80211_IF_TYPE_AP || |
58 | key->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) | |
11a843b7 JB |
59 | addr = zero_addr; |
60 | ||
61 | if (key->sta) | |
62 | addr = key->sta->addr; | |
63 | ||
64 | return addr; | |
65 | } | |
66 | ||
67 | static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key) | |
68 | { | |
69 | const u8 *addr; | |
70 | int ret; | |
0795af57 | 71 | DECLARE_MAC_BUF(mac); |
11a843b7 JB |
72 | |
73 | if (!key->local->ops->set_key) | |
74 | return; | |
75 | ||
76 | addr = get_mac_for_key(key); | |
77 | ||
78 | ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY, | |
79 | key->sdata->dev->dev_addr, addr, | |
80 | &key->conf); | |
81 | ||
11a843b7 JB |
82 | if (!ret) |
83 | key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE; | |
84 | ||
85 | if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP) | |
86 | printk(KERN_ERR "mac80211-%s: failed to set key " | |
0795af57 | 87 | "(%d, %s) to hardware (%d)\n", |
11a843b7 | 88 | wiphy_name(key->local->hw.wiphy), |
0795af57 | 89 | key->conf.keyidx, print_mac(mac, addr), ret); |
11a843b7 JB |
90 | } |
91 | ||
db4d1169 JB |
92 | static void ieee80211_key_mark_hw_accel_off(struct ieee80211_key *key) |
93 | { | |
94 | if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { | |
95 | key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; | |
96 | key->flags |= KEY_FLAG_REMOVE_FROM_HARDWARE; | |
97 | } | |
98 | } | |
99 | ||
11a843b7 JB |
100 | static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) |
101 | { | |
102 | const u8 *addr; | |
103 | int ret; | |
0795af57 | 104 | DECLARE_MAC_BUF(mac); |
11a843b7 | 105 | |
db4d1169 | 106 | if (!key || !key->local->ops->set_key) |
11a843b7 JB |
107 | return; |
108 | ||
db4d1169 JB |
109 | if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && |
110 | !(key->flags & KEY_FLAG_REMOVE_FROM_HARDWARE)) | |
11a843b7 JB |
111 | return; |
112 | ||
113 | addr = get_mac_for_key(key); | |
114 | ||
115 | ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY, | |
116 | key->sdata->dev->dev_addr, addr, | |
117 | &key->conf); | |
118 | ||
119 | if (ret) | |
120 | printk(KERN_ERR "mac80211-%s: failed to remove key " | |
0795af57 | 121 | "(%d, %s) from hardware (%d)\n", |
11a843b7 | 122 | wiphy_name(key->local->hw.wiphy), |
0795af57 | 123 | key->conf.keyidx, print_mac(mac, addr), ret); |
11a843b7 | 124 | |
db4d1169 JB |
125 | key->flags &= ~(KEY_FLAG_UPLOADED_TO_HARDWARE | |
126 | KEY_FLAG_REMOVE_FROM_HARDWARE); | |
11a843b7 JB |
127 | } |
128 | ||
db4d1169 | 129 | struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg, |
11a843b7 JB |
130 | int idx, |
131 | size_t key_len, | |
132 | const u8 *key_data) | |
1f5a7e47 JB |
133 | { |
134 | struct ieee80211_key *key; | |
135 | ||
d4e46a3d | 136 | BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS); |
11a843b7 JB |
137 | |
138 | key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL); | |
1f5a7e47 JB |
139 | if (!key) |
140 | return NULL; | |
11a843b7 JB |
141 | |
142 | /* | |
143 | * Default to software encryption; we'll later upload the | |
144 | * key to the hardware if possible. | |
145 | */ | |
11a843b7 JB |
146 | key->conf.flags = 0; |
147 | key->flags = 0; | |
148 | ||
149 | key->conf.alg = alg; | |
150 | key->conf.keyidx = idx; | |
151 | key->conf.keylen = key_len; | |
152 | memcpy(key->conf.key, key_data, key_len); | |
153 | ||
11a843b7 JB |
154 | if (alg == ALG_CCMP) { |
155 | /* | |
156 | * Initialize AES key state here as an optimization so that | |
157 | * it does not need to be initialized for every packet. | |
158 | */ | |
159 | key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data); | |
160 | if (!key->u.ccmp.tfm) { | |
161 | ieee80211_key_free(key); | |
162 | return NULL; | |
163 | } | |
164 | } | |
165 | ||
db4d1169 JB |
166 | return key; |
167 | } | |
11a843b7 | 168 | |
db4d1169 JB |
169 | static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, |
170 | struct sta_info *sta, | |
171 | struct ieee80211_key *key, | |
172 | struct ieee80211_key *new) | |
173 | { | |
174 | int idx, defkey; | |
175 | ||
176 | if (sta) { | |
177 | rcu_assign_pointer(sta->key, new); | |
178 | } else { | |
179 | WARN_ON(new && key && new->conf.keyidx != key->conf.keyidx); | |
180 | ||
181 | if (key) | |
182 | idx = key->conf.keyidx; | |
183 | else | |
184 | idx = new->conf.keyidx; | |
185 | ||
186 | defkey = key && sdata->default_key == key; | |
187 | ||
188 | if (defkey && !new) | |
189 | ieee80211_set_default_key(sdata, -1); | |
190 | ||
191 | rcu_assign_pointer(sdata->keys[idx], new); | |
192 | ||
193 | if (defkey && new) | |
194 | ieee80211_set_default_key(sdata, new->conf.keyidx); | |
195 | } | |
196 | ||
197 | if (key) { | |
198 | ieee80211_key_mark_hw_accel_off(key); | |
199 | list_del(&key->list); | |
200 | } | |
201 | } | |
202 | ||
203 | void ieee80211_key_link(struct ieee80211_key *key, | |
204 | struct ieee80211_sub_if_data *sdata, | |
205 | struct sta_info *sta) | |
206 | { | |
207 | struct ieee80211_key *old_key; | |
208 | int idx; | |
209 | ||
210 | ASSERT_RTNL(); | |
211 | might_sleep(); | |
212 | ||
213 | BUG_ON(!sdata); | |
214 | BUG_ON(!key); | |
215 | ||
216 | idx = key->conf.keyidx; | |
217 | key->local = sdata->local; | |
218 | key->sdata = sdata; | |
219 | key->sta = sta; | |
220 | ||
221 | ieee80211_debugfs_key_add(key->local, key); | |
d4e46a3d | 222 | |
11a843b7 JB |
223 | if (sta) { |
224 | ieee80211_debugfs_key_sta_link(key, sta); | |
d4e46a3d | 225 | |
11a843b7 JB |
226 | /* |
227 | * some hardware cannot handle TKIP with QoS, so | |
228 | * we indicate whether QoS could be in use. | |
229 | */ | |
230 | if (sta->flags & WLAN_STA_WME) | |
231 | key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA; | |
232 | } else { | |
51fb61e7 | 233 | if (sdata->vif.type == IEEE80211_IF_TYPE_STA) { |
11a843b7 JB |
234 | struct sta_info *ap; |
235 | ||
236 | /* same here, the AP could be using QoS */ | |
237 | ap = sta_info_get(key->local, key->sdata->u.sta.bssid); | |
238 | if (ap) { | |
239 | if (ap->flags & WLAN_STA_WME) | |
240 | key->conf.flags |= | |
241 | IEEE80211_KEY_FLAG_WMM_STA; | |
242 | sta_info_put(ap); | |
243 | } | |
244 | } | |
11a843b7 JB |
245 | } |
246 | ||
d4e46a3d | 247 | if (sta) |
db4d1169 | 248 | old_key = sta->key; |
d4e46a3d | 249 | else |
db4d1169 JB |
250 | old_key = sdata->keys[idx]; |
251 | ||
252 | __ieee80211_key_replace(sdata, sta, old_key, key); | |
d4e46a3d JB |
253 | |
254 | list_add(&key->list, &sdata->key_list); | |
255 | ||
db4d1169 JB |
256 | synchronize_rcu(); |
257 | ||
258 | ieee80211_key_free(old_key); | |
259 | ieee80211_key_enable_hw_accel(key); | |
1f5a7e47 JB |
260 | } |
261 | ||
8f37171a | 262 | void ieee80211_key_free(struct ieee80211_key *key) |
1f5a7e47 | 263 | { |
db4d1169 JB |
264 | ASSERT_RTNL(); |
265 | might_sleep(); | |
266 | ||
8f37171a JB |
267 | if (!key) |
268 | return; | |
1f5a7e47 | 269 | |
db4d1169 JB |
270 | if (key->sdata) { |
271 | /* | |
272 | * Replace key with nothingness. | |
273 | * | |
274 | * Because other code may have key reference (RCU protected) | |
275 | * right now, we then wait for a grace period before freeing | |
276 | * it. | |
277 | */ | |
278 | __ieee80211_key_replace(key->sdata, key->sta, key, NULL); | |
11a843b7 | 279 | |
db4d1169 | 280 | synchronize_rcu(); |
d4e46a3d | 281 | |
db4d1169 JB |
282 | /* |
283 | * Remove from hwaccel if appropriate, this will | |
284 | * only happen when the key is actually unlinked, | |
285 | * it will already be done when the key was replaced. | |
286 | */ | |
287 | ieee80211_key_disable_hw_accel(key); | |
288 | } | |
d4e46a3d | 289 | |
8f20fc24 | 290 | if (key->conf.alg == ALG_CCMP) |
1f5a7e47 JB |
291 | ieee80211_aes_key_free(key->u.ccmp.tfm); |
292 | ieee80211_debugfs_key_remove(key); | |
11a843b7 | 293 | |
1f5a7e47 JB |
294 | kfree(key); |
295 | } | |
11a843b7 JB |
296 | |
297 | void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx) | |
298 | { | |
299 | struct ieee80211_key *key = NULL; | |
300 | ||
301 | if (idx >= 0 && idx < NUM_DEFAULT_KEYS) | |
302 | key = sdata->keys[idx]; | |
303 | ||
304 | if (sdata->default_key != key) { | |
305 | ieee80211_debugfs_key_remove_default(sdata); | |
306 | ||
d4e46a3d | 307 | rcu_assign_pointer(sdata->default_key, key); |
11a843b7 JB |
308 | |
309 | if (sdata->default_key) | |
310 | ieee80211_debugfs_key_add_default(sdata); | |
11a843b7 JB |
311 | } |
312 | } | |
313 | ||
314 | void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata) | |
315 | { | |
316 | struct ieee80211_key *key, *tmp; | |
db4d1169 JB |
317 | LIST_HEAD(tmp_list); |
318 | ||
319 | ASSERT_RTNL(); | |
320 | might_sleep(); | |
11a843b7 JB |
321 | |
322 | list_for_each_entry_safe(key, tmp, &sdata->key_list, list) | |
323 | ieee80211_key_free(key); | |
324 | } | |
325 | ||
326 | void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata) | |
327 | { | |
328 | struct ieee80211_key *key; | |
329 | ||
db4d1169 JB |
330 | ASSERT_RTNL(); |
331 | might_sleep(); | |
332 | ||
333 | if (WARN_ON(!netif_running(sdata->dev))) | |
11a843b7 JB |
334 | return; |
335 | ||
336 | list_for_each_entry(key, &sdata->key_list, list) | |
337 | ieee80211_key_enable_hw_accel(key); | |
338 | } | |
339 | ||
340 | void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata) | |
341 | { | |
342 | struct ieee80211_key *key; | |
343 | ||
db4d1169 JB |
344 | ASSERT_RTNL(); |
345 | might_sleep(); | |
346 | ||
11a843b7 JB |
347 | list_for_each_entry(key, &sdata->key_list, list) |
348 | ieee80211_key_disable_hw_accel(key); | |
349 | } |