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>
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 <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "debugfs_key.h"
24 * DOC: Key handling basics
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.
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
36 * All operations here are called under RTNL so no extra locking is
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.
44 static const u8 bcast_addr
[ETH_ALEN
] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
45 static const u8 zero_addr
[ETH_ALEN
];
47 static const u8
*get_mac_for_key(struct ieee80211_key
*key
)
49 const u8
*addr
= bcast_addr
;
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.
56 if (key
->conf
.alg
!= ALG_WEP
&&
57 (key
->sdata
->vif
.type
== IEEE80211_IF_TYPE_AP
||
58 key
->sdata
->vif
.type
== IEEE80211_IF_TYPE_VLAN
))
62 addr
= key
->sta
->addr
;
67 static void ieee80211_key_enable_hw_accel(struct ieee80211_key
*key
)
73 if (!key
->local
->ops
->set_key
)
76 addr
= get_mac_for_key(key
);
78 ret
= key
->local
->ops
->set_key(local_to_hw(key
->local
), SET_KEY
,
79 key
->sdata
->dev
->dev_addr
, addr
,
83 key
->flags
|= KEY_FLAG_UPLOADED_TO_HARDWARE
;
85 if (ret
&& ret
!= -ENOSPC
&& ret
!= -EOPNOTSUPP
)
86 printk(KERN_ERR
"mac80211-%s: failed to set key "
87 "(%d, %s) to hardware (%d)\n",
88 wiphy_name(key
->local
->hw
.wiphy
),
89 key
->conf
.keyidx
, print_mac(mac
, addr
), ret
);
92 static void ieee80211_key_mark_hw_accel_off(struct ieee80211_key
*key
)
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
;
100 static void ieee80211_key_disable_hw_accel(struct ieee80211_key
*key
)
104 DECLARE_MAC_BUF(mac
);
106 if (!key
|| !key
->local
->ops
->set_key
)
109 if (!(key
->flags
& KEY_FLAG_UPLOADED_TO_HARDWARE
) &&
110 !(key
->flags
& KEY_FLAG_REMOVE_FROM_HARDWARE
))
113 addr
= get_mac_for_key(key
);
115 ret
= key
->local
->ops
->set_key(local_to_hw(key
->local
), DISABLE_KEY
,
116 key
->sdata
->dev
->dev_addr
, addr
,
120 printk(KERN_ERR
"mac80211-%s: failed to remove key "
121 "(%d, %s) from hardware (%d)\n",
122 wiphy_name(key
->local
->hw
.wiphy
),
123 key
->conf
.keyidx
, print_mac(mac
, addr
), ret
);
125 key
->flags
&= ~(KEY_FLAG_UPLOADED_TO_HARDWARE
|
126 KEY_FLAG_REMOVE_FROM_HARDWARE
);
129 struct ieee80211_key
*ieee80211_key_alloc(enum ieee80211_key_alg alg
,
134 struct ieee80211_key
*key
;
136 BUG_ON(idx
< 0 || idx
>= NUM_DEFAULT_KEYS
);
138 key
= kzalloc(sizeof(struct ieee80211_key
) + key_len
, GFP_KERNEL
);
143 * Default to software encryption; we'll later upload the
144 * key to the hardware if possible.
150 key
->conf
.keyidx
= idx
;
151 key
->conf
.keylen
= key_len
;
152 memcpy(key
->conf
.key
, key_data
, key_len
);
153 INIT_LIST_HEAD(&key
->list
);
155 if (alg
== ALG_CCMP
) {
157 * Initialize AES key state here as an optimization so that
158 * it does not need to be initialized for every packet.
160 key
->u
.ccmp
.tfm
= ieee80211_aes_key_setup_encrypt(key_data
);
161 if (!key
->u
.ccmp
.tfm
) {
162 ieee80211_key_free(key
);
170 static void __ieee80211_key_replace(struct ieee80211_sub_if_data
*sdata
,
171 struct sta_info
*sta
,
172 struct ieee80211_key
*key
,
173 struct ieee80211_key
*new)
178 list_add(&new->list
, &sdata
->key_list
);
181 rcu_assign_pointer(sta
->key
, new);
183 WARN_ON(new && key
&& new->conf
.keyidx
!= key
->conf
.keyidx
);
186 idx
= key
->conf
.keyidx
;
188 idx
= new->conf
.keyidx
;
190 defkey
= key
&& sdata
->default_key
== key
;
193 ieee80211_set_default_key(sdata
, -1);
195 rcu_assign_pointer(sdata
->keys
[idx
], new);
197 ieee80211_set_default_key(sdata
, new->conf
.keyidx
);
201 ieee80211_key_mark_hw_accel_off(key
);
203 * We'll use an empty list to indicate that the key
204 * has already been removed.
206 list_del_init(&key
->list
);
210 void ieee80211_key_link(struct ieee80211_key
*key
,
211 struct ieee80211_sub_if_data
*sdata
,
212 struct sta_info
*sta
)
214 struct ieee80211_key
*old_key
;
223 idx
= key
->conf
.keyidx
;
224 key
->local
= sdata
->local
;
228 ieee80211_debugfs_key_add(key
->local
, key
);
231 ieee80211_debugfs_key_sta_link(key
, sta
);
234 * some hardware cannot handle TKIP with QoS, so
235 * we indicate whether QoS could be in use.
237 if (sta
->flags
& WLAN_STA_WME
)
238 key
->conf
.flags
|= IEEE80211_KEY_FLAG_WMM_STA
;
240 if (sdata
->vif
.type
== IEEE80211_IF_TYPE_STA
) {
245 /* same here, the AP could be using QoS */
246 ap
= sta_info_get(key
->local
, key
->sdata
->u
.sta
.bssid
);
248 if (ap
->flags
& WLAN_STA_WME
)
250 IEEE80211_KEY_FLAG_WMM_STA
;
260 old_key
= sdata
->keys
[idx
];
262 __ieee80211_key_replace(sdata
, sta
, old_key
, key
);
266 ieee80211_key_free(old_key
);
269 if (netif_running(sdata
->dev
))
270 ieee80211_key_enable_hw_accel(key
);
273 void ieee80211_key_free(struct ieee80211_key
*key
)
283 * Replace key with nothingness.
285 * Because other code may have key reference (RCU protected)
286 * right now, we then wait for a grace period before freeing
288 * An empty list indicates it was never added to the key list
289 * or has been removed already. It may, however, still be in
290 * hardware for acceleration.
292 if (!list_empty(&key
->list
))
293 __ieee80211_key_replace(key
->sdata
, key
->sta
,
297 * Do NOT remove this without looking at sta_info_destroy()
302 * Remove from hwaccel if appropriate, this will
303 * only happen when the key is actually unlinked,
304 * it will already be done when the key was replaced.
306 ieee80211_key_disable_hw_accel(key
);
309 if (key
->conf
.alg
== ALG_CCMP
)
310 ieee80211_aes_key_free(key
->u
.ccmp
.tfm
);
311 ieee80211_debugfs_key_remove(key
);
316 void ieee80211_set_default_key(struct ieee80211_sub_if_data
*sdata
, int idx
)
318 struct ieee80211_key
*key
= NULL
;
320 if (idx
>= 0 && idx
< NUM_DEFAULT_KEYS
)
321 key
= sdata
->keys
[idx
];
323 if (sdata
->default_key
!= key
) {
324 ieee80211_debugfs_key_remove_default(sdata
);
326 rcu_assign_pointer(sdata
->default_key
, key
);
328 if (sdata
->default_key
)
329 ieee80211_debugfs_key_add_default(sdata
);
333 void ieee80211_free_keys(struct ieee80211_sub_if_data
*sdata
)
335 struct ieee80211_key
*key
, *tmp
;
341 list_for_each_entry_safe(key
, tmp
, &sdata
->key_list
, list
)
342 ieee80211_key_free(key
);
345 void ieee80211_enable_keys(struct ieee80211_sub_if_data
*sdata
)
347 struct ieee80211_key
*key
;
352 if (WARN_ON(!netif_running(sdata
->dev
)))
355 list_for_each_entry(key
, &sdata
->key_list
, list
)
356 ieee80211_key_enable_hw_accel(key
);
359 void ieee80211_disable_keys(struct ieee80211_sub_if_data
*sdata
)
361 struct ieee80211_key
*key
;
366 list_for_each_entry(key
, &sdata
->key_list
, list
)
367 ieee80211_key_disable_hw_accel(key
);