* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#include <linux/if_ether.h>
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "debugfs_key.h"
#include "aes_ccm.h"
+
+/*
+ * Key handling basics
+ *
+ * Key handling in mac80211 is done based on per-interface (sub_if_data)
+ * keys and per-station keys. Since each station belongs to an interface,
+ * each station key also belongs to that interface.
+ *
+ * Hardware acceleration is done on a best-effort basis, for each key
+ * that is eligible the hardware is asked to enable that key but if
+ * it cannot do that they key is simply kept for software encryption.
+ * There is currently no way of knowing this except by looking into
+ * debugfs.
+ *
+ * All operations here are called under RTNL so no extra locking is
+ * required.
+ */
+
+static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
+static const u8 zero_addr[ETH_ALEN];
+
+static const u8 *get_mac_for_key(struct ieee80211_key *key)
+{
+ const u8 *addr = bcast_addr;
+
+ /*
+ * If we're an AP we won't ever receive frames with a non-WEP
+ * group key so we tell the driver that by using the zero MAC
+ * address to indicate a transmit-only key.
+ */
+ if (key->conf.alg != ALG_WEP &&
+ (key->sdata->vif.type == IEEE80211_IF_TYPE_AP ||
+ key->sdata->vif.type == IEEE80211_IF_TYPE_VLAN))
+ addr = zero_addr;
+
+ if (key->sta)
+ addr = key->sta->addr;
+
+ return addr;
+}
+
+static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
+{
+ const u8 *addr;
+ int ret;
+ DECLARE_MAC_BUF(mac);
+
+ if (!key->local->ops->set_key)
+ return;
+
+ addr = get_mac_for_key(key);
+
+ ret = key->local->ops->set_key(local_to_hw(key->local), SET_KEY,
+ key->sdata->dev->dev_addr, addr,
+ &key->conf);
+
+ if (!ret)
+ key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
+
+ if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
+ printk(KERN_ERR "mac80211-%s: failed to set key "
+ "(%d, %s) to hardware (%d)\n",
+ wiphy_name(key->local->hw.wiphy),
+ key->conf.keyidx, print_mac(mac, addr), ret);
+}
+
+static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
+{
+ const u8 *addr;
+ int ret;
+ DECLARE_MAC_BUF(mac);
+
+ if (!key->local->ops->set_key)
+ return;
+
+ if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
+ return;
+
+ addr = get_mac_for_key(key);
+
+ ret = key->local->ops->set_key(local_to_hw(key->local), DISABLE_KEY,
+ key->sdata->dev->dev_addr, addr,
+ &key->conf);
+
+ if (ret)
+ printk(KERN_ERR "mac80211-%s: failed to remove key "
+ "(%d, %s) from hardware (%d)\n",
+ wiphy_name(key->local->hw.wiphy),
+ key->conf.keyidx, print_mac(mac, addr), ret);
+
+ key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
+}
+
struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
- int idx, size_t key_len, gfp_t flags)
+ struct sta_info *sta,
+ enum ieee80211_key_alg alg,
+ int idx,
+ size_t key_len,
+ const u8 *key_data)
{
struct ieee80211_key *key;
- key = kzalloc(sizeof(struct ieee80211_key) + key_len, flags);
+ BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
+
+ key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
if (!key)
return NULL;
- kref_init(&key->kref);
+
+ /*
+ * Default to software encryption; we'll later upload the
+ * key to the hardware if possible.
+ */
+ key->conf.flags = 0;
+ key->flags = 0;
+
+ key->conf.alg = alg;
+ key->conf.keyidx = idx;
+ key->conf.keylen = key_len;
+ memcpy(key->conf.key, key_data, key_len);
+
+ key->local = sdata->local;
+ key->sdata = sdata;
+ key->sta = sta;
+
+ if (alg == ALG_CCMP) {
+ /*
+ * Initialize AES key state here as an optimization so that
+ * it does not need to be initialized for every packet.
+ */
+ key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
+ if (!key->u.ccmp.tfm) {
+ ieee80211_key_free(key);
+ return NULL;
+ }
+ }
+
+ ieee80211_debugfs_key_add(key->local, key);
+
+ /* remove key first */
+ if (sta)
+ ieee80211_key_free(sta->key);
+ else
+ ieee80211_key_free(sdata->keys[idx]);
+
+ if (sta) {
+ ieee80211_debugfs_key_sta_link(key, sta);
+
+ /*
+ * some hardware cannot handle TKIP with QoS, so
+ * we indicate whether QoS could be in use.
+ */
+ if (sta->flags & WLAN_STA_WME)
+ key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
+ } else {
+ if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
+ struct sta_info *ap;
+
+ /* same here, the AP could be using QoS */
+ ap = sta_info_get(key->local, key->sdata->u.sta.bssid);
+ if (ap) {
+ if (ap->flags & WLAN_STA_WME)
+ key->conf.flags |=
+ IEEE80211_KEY_FLAG_WMM_STA;
+ sta_info_put(ap);
+ }
+ }
+ }
+
+ /* enable hwaccel if appropriate */
+ if (netif_running(key->sdata->dev))
+ ieee80211_key_enable_hw_accel(key);
+
+ if (sta)
+ rcu_assign_pointer(sta->key, key);
+ else
+ rcu_assign_pointer(sdata->keys[idx], key);
+
+ list_add(&key->list, &sdata->key_list);
+
return key;
}
-static void ieee80211_key_release(struct kref *kref)
+void ieee80211_key_free(struct ieee80211_key *key)
{
- struct ieee80211_key *key;
+ if (!key)
+ return;
+
+ if (key->sta) {
+ rcu_assign_pointer(key->sta->key, NULL);
+ } else {
+ if (key->sdata->default_key == key)
+ ieee80211_set_default_key(key->sdata, -1);
+ if (key->conf.keyidx >= 0 &&
+ key->conf.keyidx < NUM_DEFAULT_KEYS)
+ rcu_assign_pointer(key->sdata->keys[key->conf.keyidx],
+ NULL);
+ else
+ WARN_ON(1);
+ }
+
+ /* wait for all key users to complete */
+ synchronize_rcu();
+
+ /* remove from hwaccel if appropriate */
+ ieee80211_key_disable_hw_accel(key);
- key = container_of(kref, struct ieee80211_key, kref);
if (key->conf.alg == ALG_CCMP)
ieee80211_aes_key_free(key->u.ccmp.tfm);
ieee80211_debugfs_key_remove(key);
+
+ list_del(&key->list);
+
kfree(key);
}
-void ieee80211_key_free(struct ieee80211_key *key)
+void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ struct ieee80211_key *key = NULL;
+
+ if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
+ key = sdata->keys[idx];
+
+ if (sdata->default_key != key) {
+ ieee80211_debugfs_key_remove_default(sdata);
+
+ rcu_assign_pointer(sdata->default_key, key);
+
+ if (sdata->default_key)
+ ieee80211_debugfs_key_add_default(sdata);
+ }
+}
+
+void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_key *key, *tmp;
+
+ list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
+ ieee80211_key_free(key);
+}
+
+void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
{
- if (key)
- kref_put(&key->kref, ieee80211_key_release);
+ struct ieee80211_key *key;
+
+ WARN_ON(!netif_running(sdata->dev));
+ if (!netif_running(sdata->dev))
+ return;
+
+ list_for_each_entry(key, &sdata->key_list, list)
+ ieee80211_key_enable_hw_accel(key);
+}
+
+void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_key *key;
+
+ list_for_each_entry(key, &sdata->key_list, list)
+ ieee80211_key_disable_hw_accel(key);
}