acrn-kernel/net/mac80211/key.c

280 lines
6.7 KiB
C

/*
* 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->type == IEEE80211_IF_TYPE_AP ||
key->sdata->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,
struct sta_info *sta,
enum ieee80211_key_alg alg,
int idx,
size_t key_len,
const u8 *key_data)
{
struct ieee80211_key *key;
BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
if (!key)
return NULL;
/*
* 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->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;
}
void ieee80211_key_free(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);
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_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)
{
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);
}