![Johannes Berg](/assets/img/avatar_default.png)
This adds API to allow adding per-station GTKs, updates mac80211 to support it, and also allows drivers to remove a key from hwaccel again when this may be necessary due to multiple GTKs. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
513 lines
12 KiB
C
513 lines
12 KiB
C
/*
|
|
* Copyright 2002-2005, Instant802 Networks, Inc.
|
|
* Copyright 2005-2006, Devicescape Software, Inc.
|
|
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
|
|
* Copyright 2007-2008 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 <linux/rtnetlink.h>
|
|
#include <linux/slab.h>
|
|
#include <net/mac80211.h>
|
|
#include "ieee80211_i.h"
|
|
#include "driver-ops.h"
|
|
#include "debugfs_key.h"
|
|
#include "aes_ccm.h"
|
|
#include "aes_cmac.h"
|
|
|
|
|
|
/**
|
|
* DOC: 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 key operations are protected internally.
|
|
*
|
|
* Within mac80211, key references are, just as STA structure references,
|
|
* protected by RCU. Note, however, that some things are unprotected,
|
|
* namely the key->sta dereferences within the hardware acceleration
|
|
* functions. This means that sta_info_destroy() must remove the key
|
|
* which waits for an RCU grace period.
|
|
*/
|
|
|
|
static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
|
|
|
static void assert_key_lock(struct ieee80211_local *local)
|
|
{
|
|
lockdep_assert_held(&local->key_mtx);
|
|
}
|
|
|
|
static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
|
|
{
|
|
if (key->sta)
|
|
return &key->sta->sta;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
|
|
{
|
|
struct ieee80211_sub_if_data *sdata;
|
|
struct ieee80211_sta *sta;
|
|
int ret;
|
|
|
|
might_sleep();
|
|
|
|
if (!key->local->ops->set_key)
|
|
goto out_unsupported;
|
|
|
|
assert_key_lock(key->local);
|
|
|
|
sta = get_sta_for_key(key);
|
|
|
|
/*
|
|
* If this is a per-STA GTK, check if it
|
|
* is supported; if not, return.
|
|
*/
|
|
if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
|
|
!(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
|
|
goto out_unsupported;
|
|
|
|
sdata = key->sdata;
|
|
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
|
|
sdata = container_of(sdata->bss,
|
|
struct ieee80211_sub_if_data,
|
|
u.ap);
|
|
|
|
ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
|
|
|
|
if (!ret) {
|
|
key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
|
|
return 0;
|
|
}
|
|
|
|
if (ret != -ENOSPC && ret != -EOPNOTSUPP)
|
|
wiphy_err(key->local->hw.wiphy,
|
|
"failed to set key (%d, %pM) to hardware (%d)\n",
|
|
key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
|
|
|
|
out_unsupported:
|
|
switch (key->conf.cipher) {
|
|
case WLAN_CIPHER_SUITE_WEP40:
|
|
case WLAN_CIPHER_SUITE_WEP104:
|
|
case WLAN_CIPHER_SUITE_TKIP:
|
|
case WLAN_CIPHER_SUITE_CCMP:
|
|
case WLAN_CIPHER_SUITE_AES_CMAC:
|
|
/* all of these we can do in software */
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
|
|
{
|
|
struct ieee80211_sub_if_data *sdata;
|
|
struct ieee80211_sta *sta;
|
|
int ret;
|
|
|
|
might_sleep();
|
|
|
|
if (!key || !key->local->ops->set_key)
|
|
return;
|
|
|
|
assert_key_lock(key->local);
|
|
|
|
if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
|
|
return;
|
|
|
|
sta = get_sta_for_key(key);
|
|
sdata = key->sdata;
|
|
|
|
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
|
|
sdata = container_of(sdata->bss,
|
|
struct ieee80211_sub_if_data,
|
|
u.ap);
|
|
|
|
ret = drv_set_key(key->local, DISABLE_KEY, sdata,
|
|
sta, &key->conf);
|
|
|
|
if (ret)
|
|
wiphy_err(key->local->hw.wiphy,
|
|
"failed to remove key (%d, %pM) from hardware (%d)\n",
|
|
key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
|
|
|
|
key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
|
|
}
|
|
|
|
void ieee80211_key_removed(struct ieee80211_key_conf *key_conf)
|
|
{
|
|
struct ieee80211_key *key;
|
|
|
|
key = container_of(key_conf, struct ieee80211_key, conf);
|
|
|
|
might_sleep();
|
|
assert_key_lock(key->local);
|
|
|
|
key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
|
|
|
|
/*
|
|
* Flush TX path to avoid attempts to use this key
|
|
* after this function returns. Until then, drivers
|
|
* must be prepared to handle the key.
|
|
*/
|
|
synchronize_rcu();
|
|
}
|
|
EXPORT_SYMBOL_GPL(ieee80211_key_removed);
|
|
|
|
static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
|
|
int idx)
|
|
{
|
|
struct ieee80211_key *key = NULL;
|
|
|
|
assert_key_lock(sdata->local);
|
|
|
|
if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
|
|
key = sdata->keys[idx];
|
|
|
|
rcu_assign_pointer(sdata->default_key, key);
|
|
|
|
if (key) {
|
|
ieee80211_debugfs_key_remove_default(key->sdata);
|
|
ieee80211_debugfs_key_add_default(key->sdata);
|
|
}
|
|
}
|
|
|
|
void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
|
|
{
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
__ieee80211_set_default_key(sdata, idx);
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
}
|
|
|
|
static void
|
|
__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
|
|
{
|
|
struct ieee80211_key *key = NULL;
|
|
|
|
assert_key_lock(sdata->local);
|
|
|
|
if (idx >= NUM_DEFAULT_KEYS &&
|
|
idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
|
|
key = sdata->keys[idx];
|
|
|
|
rcu_assign_pointer(sdata->default_mgmt_key, key);
|
|
|
|
if (key) {
|
|
ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
|
|
ieee80211_debugfs_key_add_mgmt_default(key->sdata);
|
|
}
|
|
}
|
|
|
|
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
|
|
int idx)
|
|
{
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
__ieee80211_set_default_mgmt_key(sdata, idx);
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
}
|
|
|
|
|
|
static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
|
|
struct sta_info *sta,
|
|
bool pairwise,
|
|
struct ieee80211_key *old,
|
|
struct ieee80211_key *new)
|
|
{
|
|
int idx, defkey, defmgmtkey;
|
|
|
|
if (new)
|
|
list_add(&new->list, &sdata->key_list);
|
|
|
|
if (sta && pairwise) {
|
|
rcu_assign_pointer(sta->ptk, new);
|
|
} else if (sta) {
|
|
if (old)
|
|
idx = old->conf.keyidx;
|
|
else
|
|
idx = new->conf.keyidx;
|
|
rcu_assign_pointer(sta->gtk[idx], new);
|
|
} else {
|
|
WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
|
|
|
|
if (old)
|
|
idx = old->conf.keyidx;
|
|
else
|
|
idx = new->conf.keyidx;
|
|
|
|
defkey = old && sdata->default_key == old;
|
|
defmgmtkey = old && sdata->default_mgmt_key == old;
|
|
|
|
if (defkey && !new)
|
|
__ieee80211_set_default_key(sdata, -1);
|
|
if (defmgmtkey && !new)
|
|
__ieee80211_set_default_mgmt_key(sdata, -1);
|
|
|
|
rcu_assign_pointer(sdata->keys[idx], new);
|
|
if (defkey && new)
|
|
__ieee80211_set_default_key(sdata, new->conf.keyidx);
|
|
if (defmgmtkey && new)
|
|
__ieee80211_set_default_mgmt_key(sdata,
|
|
new->conf.keyidx);
|
|
}
|
|
|
|
if (old) {
|
|
/*
|
|
* We'll use an empty list to indicate that the key
|
|
* has already been removed.
|
|
*/
|
|
list_del_init(&old->list);
|
|
}
|
|
}
|
|
|
|
struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
|
|
const u8 *key_data,
|
|
size_t seq_len, const u8 *seq)
|
|
{
|
|
struct ieee80211_key *key;
|
|
int i, j, err;
|
|
|
|
BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
|
|
|
|
key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
|
|
if (!key)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* Default to software encryption; we'll later upload the
|
|
* key to the hardware if possible.
|
|
*/
|
|
key->conf.flags = 0;
|
|
key->flags = 0;
|
|
|
|
key->conf.cipher = cipher;
|
|
key->conf.keyidx = idx;
|
|
key->conf.keylen = key_len;
|
|
switch (cipher) {
|
|
case WLAN_CIPHER_SUITE_WEP40:
|
|
case WLAN_CIPHER_SUITE_WEP104:
|
|
key->conf.iv_len = WEP_IV_LEN;
|
|
key->conf.icv_len = WEP_ICV_LEN;
|
|
break;
|
|
case WLAN_CIPHER_SUITE_TKIP:
|
|
key->conf.iv_len = TKIP_IV_LEN;
|
|
key->conf.icv_len = TKIP_ICV_LEN;
|
|
if (seq) {
|
|
for (i = 0; i < NUM_RX_DATA_QUEUES; i++) {
|
|
key->u.tkip.rx[i].iv32 =
|
|
get_unaligned_le32(&seq[2]);
|
|
key->u.tkip.rx[i].iv16 =
|
|
get_unaligned_le16(seq);
|
|
}
|
|
}
|
|
break;
|
|
case WLAN_CIPHER_SUITE_CCMP:
|
|
key->conf.iv_len = CCMP_HDR_LEN;
|
|
key->conf.icv_len = CCMP_MIC_LEN;
|
|
if (seq) {
|
|
for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++)
|
|
for (j = 0; j < CCMP_PN_LEN; j++)
|
|
key->u.ccmp.rx_pn[i][j] =
|
|
seq[CCMP_PN_LEN - j - 1];
|
|
}
|
|
/*
|
|
* 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 (IS_ERR(key->u.ccmp.tfm)) {
|
|
err = PTR_ERR(key->u.ccmp.tfm);
|
|
kfree(key);
|
|
key = ERR_PTR(err);
|
|
}
|
|
break;
|
|
case WLAN_CIPHER_SUITE_AES_CMAC:
|
|
key->conf.iv_len = 0;
|
|
key->conf.icv_len = sizeof(struct ieee80211_mmie);
|
|
if (seq)
|
|
for (j = 0; j < 6; j++)
|
|
key->u.aes_cmac.rx_pn[j] = seq[6 - j - 1];
|
|
/*
|
|
* Initialize AES key state here as an optimization so that
|
|
* it does not need to be initialized for every packet.
|
|
*/
|
|
key->u.aes_cmac.tfm =
|
|
ieee80211_aes_cmac_key_setup(key_data);
|
|
if (IS_ERR(key->u.aes_cmac.tfm)) {
|
|
err = PTR_ERR(key->u.aes_cmac.tfm);
|
|
kfree(key);
|
|
key = ERR_PTR(err);
|
|
}
|
|
break;
|
|
}
|
|
memcpy(key->conf.key, key_data, key_len);
|
|
INIT_LIST_HEAD(&key->list);
|
|
|
|
return key;
|
|
}
|
|
|
|
static void __ieee80211_key_destroy(struct ieee80211_key *key)
|
|
{
|
|
if (!key)
|
|
return;
|
|
|
|
if (key->local)
|
|
ieee80211_key_disable_hw_accel(key);
|
|
|
|
if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
|
|
ieee80211_aes_key_free(key->u.ccmp.tfm);
|
|
if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
|
|
ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
|
|
if (key->local)
|
|
ieee80211_debugfs_key_remove(key);
|
|
|
|
kfree(key);
|
|
}
|
|
|
|
int ieee80211_key_link(struct ieee80211_key *key,
|
|
struct ieee80211_sub_if_data *sdata,
|
|
struct sta_info *sta)
|
|
{
|
|
struct ieee80211_key *old_key;
|
|
int idx, ret;
|
|
bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
|
|
|
|
BUG_ON(!sdata);
|
|
BUG_ON(!key);
|
|
|
|
idx = key->conf.keyidx;
|
|
key->local = sdata->local;
|
|
key->sdata = sdata;
|
|
key->sta = sta;
|
|
|
|
if (sta) {
|
|
/*
|
|
* some hardware cannot handle TKIP with QoS, so
|
|
* we indicate whether QoS could be in use.
|
|
*/
|
|
if (test_sta_flags(sta, WLAN_STA_WME))
|
|
key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
|
|
} else {
|
|
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
|
|
struct sta_info *ap;
|
|
|
|
/*
|
|
* We're getting a sta pointer in,
|
|
* so must be under RCU read lock.
|
|
*/
|
|
|
|
/* same here, the AP could be using QoS */
|
|
ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
|
|
if (ap) {
|
|
if (test_sta_flags(ap, WLAN_STA_WME))
|
|
key->conf.flags |=
|
|
IEEE80211_KEY_FLAG_WMM_STA;
|
|
}
|
|
}
|
|
}
|
|
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
|
|
if (sta && pairwise)
|
|
old_key = sta->ptk;
|
|
else if (sta)
|
|
old_key = sta->gtk[idx];
|
|
else
|
|
old_key = sdata->keys[idx];
|
|
|
|
__ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
|
|
__ieee80211_key_destroy(old_key);
|
|
|
|
ieee80211_debugfs_key_add(key);
|
|
|
|
ret = ieee80211_key_enable_hw_accel(key);
|
|
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __ieee80211_key_free(struct ieee80211_key *key)
|
|
{
|
|
/*
|
|
* Replace key with nothingness if it was ever used.
|
|
*/
|
|
if (key->sdata)
|
|
__ieee80211_key_replace(key->sdata, key->sta,
|
|
key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
|
|
key, NULL);
|
|
__ieee80211_key_destroy(key);
|
|
}
|
|
|
|
void ieee80211_key_free(struct ieee80211_local *local,
|
|
struct ieee80211_key *key)
|
|
{
|
|
if (!key)
|
|
return;
|
|
|
|
mutex_lock(&local->key_mtx);
|
|
__ieee80211_key_free(key);
|
|
mutex_unlock(&local->key_mtx);
|
|
}
|
|
|
|
void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
|
|
{
|
|
struct ieee80211_key *key;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
if (WARN_ON(!ieee80211_sdata_running(sdata)))
|
|
return;
|
|
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
|
|
list_for_each_entry(key, &sdata->key_list, list)
|
|
ieee80211_key_enable_hw_accel(key);
|
|
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
}
|
|
|
|
void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
|
|
{
|
|
struct ieee80211_key *key;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
|
|
list_for_each_entry(key, &sdata->key_list, list)
|
|
ieee80211_key_disable_hw_accel(key);
|
|
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
}
|
|
|
|
void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
|
|
{
|
|
struct ieee80211_key *key, *tmp;
|
|
|
|
mutex_lock(&sdata->local->key_mtx);
|
|
|
|
ieee80211_debugfs_key_remove_default(sdata);
|
|
ieee80211_debugfs_key_remove_mgmt_default(sdata);
|
|
|
|
list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
|
|
__ieee80211_key_free(key);
|
|
|
|
mutex_unlock(&sdata->local->key_mtx);
|
|
}
|