add git checkout support
[openwrt/openwrt.git] / package / mac80211 / src / mac80211 / key.c
1 /*
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 Johannes Berg <johannes@sipsolutions.net>
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
12 #include <linux/if_ether.h>
13 #include <linux/etherdevice.h>
14 #include <linux/list.h>
15 #include <linux/rcupdate.h>
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "debugfs_key.h"
19 #include "aes_ccm.h"
20
21
22 /*
23 * Key handling basics
24 *
25 * Key handling in mac80211 is done based on per-interface (sub_if_data)
26 * keys and per-station keys. Since each station belongs to an interface,
27 * each station key also belongs to that interface.
28 *
29 * Hardware acceleration is done on a best-effort basis, for each key
30 * that is eligible the hardware is asked to enable that key but if
31 * it cannot do that they key is simply kept for software encryption.
32 * There is currently no way of knowing this except by looking into
33 * debugfs.
34 *
35 * All operations here are called under RTNL so no extra locking is
36 * required.
37 */
38
39 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
40 static const u8 zero_addr[ETH_ALEN];
41
42 static const u8 *get_mac_for_key(struct ieee80211_key *key)
43 {
44 const u8 *addr = bcast_addr;
45
46 /*
47 * If we're an AP we won't ever receive frames with a non-WEP
48 * group key so we tell the driver that by using the zero MAC
49 * address to indicate a transmit-only key.
50 */
51 if (key->conf.alg != ALG_WEP &&
52 (key->sdata->type == IEEE80211_IF_TYPE_AP ||
53 key->sdata->type == IEEE80211_IF_TYPE_VLAN))
54 addr = zero_addr;
55
56 if (key->sta)
57 addr = key->sta->addr;
58
59 return addr;
60 }
61
62 static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
63 {
64 const u8 *addr;
65 int ret;
66
67 if (!key->local->ops->set_key)
68 return;
69
70 addr = get_mac_for_key(key);
71
72 ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY,
73 key->sdata->dev->dev_addr, addr,
74 &key->conf);
75
76 if (!ret)
77 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
78
79 if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
80 printk(KERN_ERR "mac80211-%s: failed to set key "
81 "(%d, " MAC_FMT ") to hardware (%d)\n",
82 wiphy_name(key->local->hw.wiphy),
83 key->conf.keyidx, MAC_ARG(addr), ret);
84 }
85
86 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
87 {
88 const u8 *addr;
89 int ret;
90
91 if (!key->local->ops->set_key)
92 return;
93
94 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
95 return;
96
97 addr = get_mac_for_key(key);
98
99 ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY,
100 key->sdata->dev->dev_addr, addr,
101 &key->conf);
102
103 if (ret)
104 printk(KERN_ERR "mac80211-%s: failed to remove key "
105 "(%d, " MAC_FMT ") from hardware (%d)\n",
106 wiphy_name(key->local->hw.wiphy),
107 key->conf.keyidx, MAC_ARG(addr), ret);
108
109 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
110 }
111
112 struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
113 struct sta_info *sta,
114 enum ieee80211_key_alg alg,
115 int idx,
116 size_t key_len,
117 const u8 *key_data)
118 {
119 struct ieee80211_key *key;
120
121 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
122
123 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
124 if (!key)
125 return NULL;
126
127 /*
128 * Default to software encryption; we'll later upload the
129 * key to the hardware if possible.
130 */
131 key->conf.flags = 0;
132 key->flags = 0;
133
134 key->conf.alg = alg;
135 key->conf.keyidx = idx;
136 key->conf.keylen = key_len;
137 memcpy(key->conf.key, key_data, key_len);
138
139 key->local = sdata->local;
140 key->sdata = sdata;
141 key->sta = sta;
142
143 if (alg == ALG_CCMP) {
144 /*
145 * Initialize AES key state here as an optimization so that
146 * it does not need to be initialized for every packet.
147 */
148 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
149 if (!key->u.ccmp.tfm) {
150 ieee80211_key_free(key);
151 return NULL;
152 }
153 }
154
155 ieee80211_debugfs_key_add(key->local, key);
156
157 /* remove key first */
158 if (sta)
159 ieee80211_key_free(sta->key);
160 else
161 ieee80211_key_free(sdata->keys[idx]);
162
163 if (sta) {
164 ieee80211_debugfs_key_sta_link(key, sta);
165
166 /*
167 * some hardware cannot handle TKIP with QoS, so
168 * we indicate whether QoS could be in use.
169 */
170 if (sta->flags & WLAN_STA_WME)
171 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
172 } else {
173 if (sdata->type == IEEE80211_IF_TYPE_STA) {
174 struct sta_info *ap;
175
176 /* same here, the AP could be using QoS */
177 ap = sta_info_get(key->local, key->sdata->u.sta.bssid);
178 if (ap) {
179 if (ap->flags & WLAN_STA_WME)
180 key->conf.flags |=
181 IEEE80211_KEY_FLAG_WMM_STA;
182 sta_info_put(ap);
183 }
184 }
185 }
186
187 /* enable hwaccel if appropriate */
188 if (netif_running(key->sdata->dev))
189 ieee80211_key_enable_hw_accel(key);
190
191 if (sta)
192 rcu_assign_pointer(sta->key, key);
193 else
194 rcu_assign_pointer(sdata->keys[idx], key);
195
196 list_add(&key->list, &sdata->key_list);
197
198 return key;
199 }
200
201 void ieee80211_key_free(struct ieee80211_key *key)
202 {
203 if (!key)
204 return;
205
206 if (key->sta) {
207 rcu_assign_pointer(key->sta->key, NULL);
208 } else {
209 if (key->sdata->default_key == key)
210 ieee80211_set_default_key(key->sdata, -1);
211 if (key->conf.keyidx >= 0 &&
212 key->conf.keyidx < NUM_DEFAULT_KEYS)
213 rcu_assign_pointer(key->sdata->keys[key->conf.keyidx],
214 NULL);
215 else
216 WARN_ON(1);
217 }
218
219 /* wait for all key users to complete */
220 synchronize_rcu();
221
222 /* remove from hwaccel if appropriate */
223 ieee80211_key_disable_hw_accel(key);
224
225 if (key->conf.alg == ALG_CCMP)
226 ieee80211_aes_key_free(key->u.ccmp.tfm);
227 ieee80211_debugfs_key_remove(key);
228
229 list_del(&key->list);
230
231 kfree(key);
232 }
233
234 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
235 {
236 struct ieee80211_key *key = NULL;
237
238 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
239 key = sdata->keys[idx];
240
241 if (sdata->default_key != key) {
242 ieee80211_debugfs_key_remove_default(sdata);
243
244 rcu_assign_pointer(sdata->default_key, key);
245
246 if (sdata->default_key)
247 ieee80211_debugfs_key_add_default(sdata);
248 }
249 }
250
251 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
252 {
253 struct ieee80211_key *key, *tmp;
254
255 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
256 ieee80211_key_free(key);
257 }
258
259 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
260 {
261 struct ieee80211_key *key;
262
263 WARN_ON(!netif_running(sdata->dev));
264 if (!netif_running(sdata->dev))
265 return;
266
267 list_for_each_entry(key, &sdata->key_list, list)
268 ieee80211_key_enable_hw_accel(key);
269 }
270
271 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
272 {
273 struct ieee80211_key *key;
274
275 list_for_each_entry(key, &sdata->key_list, list)
276 ieee80211_key_disable_hw_accel(key);
277 }