[MAC80211]: remove ALG_NONE
[linux-2.6.git] / net / 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         DECLARE_MAC_BUF(mac);
67
68         if (!key->local->ops->set_key)
69                 return;
70
71         addr = get_mac_for_key(key);
72
73         ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY,
74                                        key->sdata->dev->dev_addr, addr,
75                                        &key->conf);
76
77         if (!ret)
78                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
79
80         if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
81                 printk(KERN_ERR "mac80211-%s: failed to set key "
82                        "(%d, %s) to hardware (%d)\n",
83                        wiphy_name(key->local->hw.wiphy),
84                        key->conf.keyidx, print_mac(mac, addr), ret);
85 }
86
87 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
88 {
89         const u8 *addr;
90         int ret;
91         DECLARE_MAC_BUF(mac);
92
93         if (!key->local->ops->set_key)
94                 return;
95
96         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
97                 return;
98
99         addr = get_mac_for_key(key);
100
101         ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY,
102                                        key->sdata->dev->dev_addr, addr,
103                                        &key->conf);
104
105         if (ret)
106                 printk(KERN_ERR "mac80211-%s: failed to remove key "
107                        "(%d, %s) from hardware (%d)\n",
108                        wiphy_name(key->local->hw.wiphy),
109                        key->conf.keyidx, print_mac(mac, addr), ret);
110
111         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
112 }
113
114 struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
115                                           struct sta_info *sta,
116                                           enum ieee80211_key_alg alg,
117                                           int idx,
118                                           size_t key_len,
119                                           const u8 *key_data)
120 {
121         struct ieee80211_key *key;
122
123         BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
124
125         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
126         if (!key)
127                 return NULL;
128
129         /*
130          * Default to software encryption; we'll later upload the
131          * key to the hardware if possible.
132          */
133         key->conf.flags = 0;
134         key->flags = 0;
135
136         key->conf.alg = alg;
137         key->conf.keyidx = idx;
138         key->conf.keylen = key_len;
139         memcpy(key->conf.key, key_data, key_len);
140
141         key->local = sdata->local;
142         key->sdata = sdata;
143         key->sta = sta;
144
145         if (alg == ALG_CCMP) {
146                 /*
147                  * Initialize AES key state here as an optimization so that
148                  * it does not need to be initialized for every packet.
149                  */
150                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
151                 if (!key->u.ccmp.tfm) {
152                         ieee80211_key_free(key);
153                         return NULL;
154                 }
155         }
156
157         ieee80211_debugfs_key_add(key->local, key);
158
159         /* remove key first */
160         if (sta)
161                 ieee80211_key_free(sta->key);
162         else
163                 ieee80211_key_free(sdata->keys[idx]);
164
165         if (sta) {
166                 ieee80211_debugfs_key_sta_link(key, sta);
167
168                 /*
169                  * some hardware cannot handle TKIP with QoS, so
170                  * we indicate whether QoS could be in use.
171                  */
172                 if (sta->flags & WLAN_STA_WME)
173                         key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
174         } else {
175                 if (sdata->type == IEEE80211_IF_TYPE_STA) {
176                         struct sta_info *ap;
177
178                         /* same here, the AP could be using QoS */
179                         ap = sta_info_get(key->local, key->sdata->u.sta.bssid);
180                         if (ap) {
181                                 if (ap->flags & WLAN_STA_WME)
182                                         key->conf.flags |=
183                                                 IEEE80211_KEY_FLAG_WMM_STA;
184                                 sta_info_put(ap);
185                         }
186                 }
187         }
188
189         /* enable hwaccel if appropriate */
190         if (netif_running(key->sdata->dev))
191                 ieee80211_key_enable_hw_accel(key);
192
193         if (sta)
194                 rcu_assign_pointer(sta->key, key);
195         else
196                 rcu_assign_pointer(sdata->keys[idx], key);
197
198         list_add(&key->list, &sdata->key_list);
199
200         return key;
201 }
202
203 void ieee80211_key_free(struct ieee80211_key *key)
204 {
205         if (!key)
206                 return;
207
208         if (key->sta) {
209                 rcu_assign_pointer(key->sta->key, NULL);
210         } else {
211                 if (key->sdata->default_key == key)
212                         ieee80211_set_default_key(key->sdata, -1);
213                 if (key->conf.keyidx >= 0 &&
214                     key->conf.keyidx < NUM_DEFAULT_KEYS)
215                         rcu_assign_pointer(key->sdata->keys[key->conf.keyidx],
216                                            NULL);
217                 else
218                         WARN_ON(1);
219         }
220
221         /* wait for all key users to complete */
222         synchronize_rcu();
223
224         /* remove from hwaccel if appropriate */
225         ieee80211_key_disable_hw_accel(key);
226
227         if (key->conf.alg == ALG_CCMP)
228                 ieee80211_aes_key_free(key->u.ccmp.tfm);
229         ieee80211_debugfs_key_remove(key);
230
231         list_del(&key->list);
232
233         kfree(key);
234 }
235
236 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
237 {
238         struct ieee80211_key *key = NULL;
239
240         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
241                 key = sdata->keys[idx];
242
243         if (sdata->default_key != key) {
244                 ieee80211_debugfs_key_remove_default(sdata);
245
246                 rcu_assign_pointer(sdata->default_key, key);
247
248                 if (sdata->default_key)
249                         ieee80211_debugfs_key_add_default(sdata);
250         }
251 }
252
253 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
254 {
255         struct ieee80211_key *key, *tmp;
256
257         list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
258                 ieee80211_key_free(key);
259 }
260
261 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
262 {
263         struct ieee80211_key *key;
264
265         WARN_ON(!netif_running(sdata->dev));
266         if (!netif_running(sdata->dev))
267                 return;
268
269         list_for_each_entry(key, &sdata->key_list, list)
270                 ieee80211_key_enable_hw_accel(key);
271 }
272
273 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
274 {
275         struct ieee80211_key *key;
276
277         list_for_each_entry(key, &sdata->key_list, list)
278                 ieee80211_key_disable_hw_accel(key);
279 }