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)
77 * This makes sure that all pending flushes have
78 * actually completed prior to uploading new key
79 * material to the hardware. That is necessary to
80 * avoid races between flushing STAs and adding
83 __ieee80211_run_pending_flush(key->local);
85 addr = get_mac_for_key(key);
87 ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY,
88 key->sdata->dev->dev_addr, addr,
92 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
94 if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
95 printk(KERN_ERR "mac80211-%s: failed to set key "
96 "(%d, %s) to hardware (%d)\n",
97 wiphy_name(key->local->hw.wiphy),
98 key->conf.keyidx, print_mac(mac, addr), ret);
101 static void ieee80211_key_mark_hw_accel_off(struct ieee80211_key *key)
103 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
104 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
105 key->flags |= KEY_FLAG_REMOVE_FROM_HARDWARE;
109 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
113 DECLARE_MAC_BUF(mac);
115 if (!key || !key->local->ops->set_key)
118 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
119 !(key->flags & KEY_FLAG_REMOVE_FROM_HARDWARE))
122 addr = get_mac_for_key(key);
124 ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY,
125 key->sdata->dev->dev_addr, addr,
129 printk(KERN_ERR "mac80211-%s: failed to remove key "
130 "(%d, %s) from hardware (%d)\n",
131 wiphy_name(key->local->hw.wiphy),
132 key->conf.keyidx, print_mac(mac, addr), ret);
134 key->flags &= ~(KEY_FLAG_UPLOADED_TO_HARDWARE |
135 KEY_FLAG_REMOVE_FROM_HARDWARE);
138 struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
143 struct ieee80211_key *key;
145 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
147 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
152 * Default to software encryption; we'll later upload the
153 * key to the hardware if possible.
159 key->conf.keyidx = idx;
160 key->conf.keylen = key_len;
161 memcpy(key->conf.key, key_data, key_len);
162 INIT_LIST_HEAD(&key->list);
164 if (alg == ALG_CCMP) {
166 * Initialize AES key state here as an optimization so that
167 * it does not need to be initialized for every packet.
169 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
170 if (!key->u.ccmp.tfm) {
171 ieee80211_key_free(key);
179 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
180 struct sta_info *sta,
181 struct ieee80211_key *key,
182 struct ieee80211_key *new)
187 list_add(&new->list, &sdata->key_list);
190 rcu_assign_pointer(sta->key, new);
192 WARN_ON(new && key && new->conf.keyidx != key->conf.keyidx);
195 idx = key->conf.keyidx;
197 idx = new->conf.keyidx;
199 defkey = key && sdata->default_key == key;
202 ieee80211_set_default_key(sdata, -1);
204 rcu_assign_pointer(sdata->keys[idx], new);
206 ieee80211_set_default_key(sdata, new->conf.keyidx);
210 ieee80211_key_mark_hw_accel_off(key);
212 * We'll use an empty list to indicate that the key
213 * has already been removed.
215 list_del_init(&key->list);
219 void ieee80211_key_link(struct ieee80211_key *key,
220 struct ieee80211_sub_if_data *sdata,
221 struct sta_info *sta)
223 struct ieee80211_key *old_key;
232 idx = key->conf.keyidx;
233 key->local = sdata->local;
237 ieee80211_debugfs_key_add(key->local, key);
240 ieee80211_debugfs_key_sta_link(key, sta);
243 * some hardware cannot handle TKIP with QoS, so
244 * we indicate whether QoS could be in use.
246 if (sta->flags & WLAN_STA_WME)
247 key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
249 if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
254 /* same here, the AP could be using QoS */
255 ap = sta_info_get(key->local, key->sdata->u.sta.bssid);
257 if (ap->flags & WLAN_STA_WME)
259 IEEE80211_KEY_FLAG_WMM_STA;
269 old_key = sdata->keys[idx];
271 __ieee80211_key_replace(sdata, sta, old_key, key);
275 ieee80211_key_free(old_key);
278 if (netif_running(sdata->dev))
279 ieee80211_key_enable_hw_accel(key);
282 void ieee80211_key_free(struct ieee80211_key *key)
292 * Replace key with nothingness.
294 * Because other code may have key reference (RCU protected)
295 * right now, we then wait for a grace period before freeing
297 * An empty list indicates it was never added to the key list
298 * or has been removed already. It may, however, still be in
299 * hardware for acceleration.
301 if (!list_empty(&key->list))
302 __ieee80211_key_replace(key->sdata, key->sta,
306 * Do NOT remove this without looking at sta_info_destroy()
311 * Remove from hwaccel if appropriate, this will
312 * only happen when the key is actually unlinked,
313 * it will already be done when the key was replaced.
315 ieee80211_key_disable_hw_accel(key);
318 if (key->conf.alg == ALG_CCMP)
319 ieee80211_aes_key_free(key->u.ccmp.tfm);
320 ieee80211_debugfs_key_remove(key);
325 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
327 struct ieee80211_key *key = NULL;
329 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
330 key = sdata->keys[idx];
332 if (sdata->default_key != key) {
333 ieee80211_debugfs_key_remove_default(sdata);
335 rcu_assign_pointer(sdata->default_key, key);
337 if (sdata->default_key)
338 ieee80211_debugfs_key_add_default(sdata);
342 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
344 struct ieee80211_key *key, *tmp;
350 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
351 ieee80211_key_free(key);
354 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
356 struct ieee80211_key *key;
361 if (WARN_ON(!netif_running(sdata->dev)))
364 list_for_each_entry(key, &sdata->key_list, list)
365 ieee80211_key_enable_hw_accel(key);
368 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
370 struct ieee80211_key *key;
375 list_for_each_entry(key, &sdata->key_list, list)
376 ieee80211_key_disable_hw_accel(key);