]> Pileus Git - ~andy/linux/blobdiff - net/mac80211/key.c
Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6
[~andy/linux] / net / mac80211 / key.c
index b67558c246397b0df151a33669f52b223c6c82ad..ed57fb8e82fc13ab9052fb4992524c572b1d2c6e 100644 (file)
  * 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"
 
-struct ieee80211_key_conf *
-ieee80211_key_data2conf(struct ieee80211_local *local,
-                       const struct ieee80211_key *data)
+
+/*
+ * 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)
 {
-       struct ieee80211_key_conf *conf;
+       const u8 *addr = bcast_addr;
 
-       conf = kmalloc(sizeof(*conf) + data->keylen, GFP_ATOMIC);
-       if (!conf)
-               return NULL;
+       /*
+        * 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;
 
-       conf->hw_key_idx = data->hw_key_idx;
-       conf->alg = data->alg;
-       conf->keylen = data->keylen;
-       conf->flags = 0;
-       if (data->force_sw_encrypt)
-               conf->flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
-       conf->keyidx = data->keyidx;
-       if (data->default_tx_key)
-               conf->flags |= IEEE80211_KEY_DEFAULT_TX_KEY;
-       if (local->default_wep_only)
-               conf->flags |= IEEE80211_KEY_DEFAULT_WEP_ONLY;
-       memcpy(conf->key, data->key, data->keylen);
-
-       return conf;
+       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;
 
-       key = container_of(kref, struct ieee80211_key, kref);
-       if (key->alg == ALG_CCMP)
+       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);
+
+       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);
 }