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linux/drivers/net/wireless/ath/key.c
Jouni Malinen 8e5461041f ath: Fix clearing of secondary key cache entry for TKIP 
All register writes to the key cache have to be done in pairs. However,
the clearing of a separate MIC entry with hardware revisions that use
combined MIC key layout did not do that with one of the registers. Add
the matching register write to the following register to make the KEY4
register write actually complete.

This is mostly a fix for a theoretical issue since the incorrect entry
that could potentially be left behind in the key cache would not match
with received frames. Anyway, better make this code clean the entry
correctly using paired register writes.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-02-04 16:29:52 -05:00

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/*
* Copyright (c) 2009 Atheros Communications Inc.
* Copyright (c) 2010 Bruno Randolf <br1@einfach.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <asm/unaligned.h>
#include <net/mac80211.h>
#include "ath.h"
#include "reg.h"
#define REG_READ (common->ops->read)
#define REG_WRITE(_ah, _reg, _val) (common->ops->write)(_ah, _val, _reg)
#define IEEE80211_WEP_NKID 4 /* number of key ids */
/************************/
/* Key Cache Management */
/************************/
bool ath_hw_keyreset(struct ath_common *common, u16 entry)
{
u32 keyType;
void *ah = common->ah;
if (entry >= common->keymax) {
ath_err(common, "keycache entry %u out of range\n", entry);
return false;
}
keyType = REG_READ(ah, AR_KEYTABLE_TYPE(entry));
REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), AR_KEYTABLE_TYPE_CLR);
REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), 0);
REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), 0);
if (keyType == AR_KEYTABLE_TYPE_TKIP) {
u16 micentry = entry + 64;
REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
AR_KEYTABLE_TYPE_CLR);
}
}
return true;
}
EXPORT_SYMBOL(ath_hw_keyreset);
static bool ath_hw_keysetmac(struct ath_common *common,
u16 entry, const u8 *mac)
{
u32 macHi, macLo;
u32 unicast_flag = AR_KEYTABLE_VALID;
void *ah = common->ah;
if (entry >= common->keymax) {
ath_err(common, "keycache entry %u out of range\n", entry);
return false;
}
if (mac != NULL) {
/*
* AR_KEYTABLE_VALID indicates that the address is a unicast
* address, which must match the transmitter address for
* decrypting frames.
* Not setting this bit allows the hardware to use the key
* for multicast frame decryption.
*/
if (mac[0] & 0x01)
unicast_flag = 0;
macHi = (mac[5] << 8) | mac[4];
macLo = (mac[3] << 24) |
(mac[2] << 16) |
(mac[1] << 8) |
mac[0];
macLo >>= 1;
macLo |= (macHi & 1) << 31;
macHi >>= 1;
} else {
macLo = macHi = 0;
}
REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), macLo);
REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | unicast_flag);
return true;
}
static bool ath_hw_set_keycache_entry(struct ath_common *common, u16 entry,
const struct ath_keyval *k,
const u8 *mac)
{
void *ah = common->ah;
u32 key0, key1, key2, key3, key4;
u32 keyType;
if (entry >= common->keymax) {
ath_err(common, "keycache entry %u out of range\n", entry);
return false;
}
switch (k->kv_type) {
case ATH_CIPHER_AES_OCB:
keyType = AR_KEYTABLE_TYPE_AES;
break;
case ATH_CIPHER_AES_CCM:
if (!(common->crypt_caps & ATH_CRYPT_CAP_CIPHER_AESCCM)) {
ath_dbg(common, ATH_DBG_ANY,
"AES-CCM not supported by this mac rev\n");
return false;
}
keyType = AR_KEYTABLE_TYPE_CCM;
break;
case ATH_CIPHER_TKIP:
keyType = AR_KEYTABLE_TYPE_TKIP;
if (entry + 64 >= common->keymax) {
ath_dbg(common, ATH_DBG_ANY,
"entry %u inappropriate for TKIP\n", entry);
return false;
}
break;
case ATH_CIPHER_WEP:
if (k->kv_len < WLAN_KEY_LEN_WEP40) {
ath_dbg(common, ATH_DBG_ANY,
"WEP key length %u too small\n", k->kv_len);
return false;
}
if (k->kv_len <= WLAN_KEY_LEN_WEP40)
keyType = AR_KEYTABLE_TYPE_40;
else if (k->kv_len <= WLAN_KEY_LEN_WEP104)
keyType = AR_KEYTABLE_TYPE_104;
else
keyType = AR_KEYTABLE_TYPE_128;
break;
case ATH_CIPHER_CLR:
keyType = AR_KEYTABLE_TYPE_CLR;
break;
default:
ath_err(common, "cipher %u not supported\n", k->kv_type);
return false;
}
key0 = get_unaligned_le32(k->kv_val + 0);
key1 = get_unaligned_le16(k->kv_val + 4);
key2 = get_unaligned_le32(k->kv_val + 6);
key3 = get_unaligned_le16(k->kv_val + 10);
key4 = get_unaligned_le32(k->kv_val + 12);
if (k->kv_len <= WLAN_KEY_LEN_WEP104)
key4 &= 0xff;
/*
* Note: Key cache registers access special memory area that requires
* two 32-bit writes to actually update the values in the internal
* memory. Consequently, the exact order and pairs used here must be
* maintained.
*/
if (keyType == AR_KEYTABLE_TYPE_TKIP) {
u16 micentry = entry + 64;
/*
* Write inverted key[47:0] first to avoid Michael MIC errors
* on frames that could be sent or received at the same time.
* The correct key will be written in the end once everything
* else is ready.
*/
REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), ~key0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), ~key1);
/* Write key[95:48] */
REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
/* Write key[127:96] and key type */
REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
/* Write MAC address for the entry */
(void) ath_hw_keysetmac(common, entry, mac);
if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
/*
* TKIP uses two key cache entries:
* Michael MIC TX/RX keys in the same key cache entry
* (idx = main index + 64):
* key0 [31:0] = RX key [31:0]
* key1 [15:0] = TX key [31:16]
* key1 [31:16] = reserved
* key2 [31:0] = RX key [63:32]
* key3 [15:0] = TX key [15:0]
* key3 [31:16] = reserved
* key4 [31:0] = TX key [63:32]
*/
u32 mic0, mic1, mic2, mic3, mic4;
mic0 = get_unaligned_le32(k->kv_mic + 0);
mic2 = get_unaligned_le32(k->kv_mic + 4);
mic1 = get_unaligned_le16(k->kv_txmic + 2) & 0xffff;
mic3 = get_unaligned_le16(k->kv_txmic + 0) & 0xffff;
mic4 = get_unaligned_le32(k->kv_txmic + 4);
/* Write RX[31:0] and TX[31:16] */
REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), mic1);
/* Write RX[63:32] and TX[15:0] */
REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), mic3);
/* Write TX[63:32] and keyType(reserved) */
REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), mic4);
REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
AR_KEYTABLE_TYPE_CLR);
} else {
/*
* TKIP uses four key cache entries (two for group
* keys):
* Michael MIC TX/RX keys are in different key cache
* entries (idx = main index + 64 for TX and
* main index + 32 + 96 for RX):
* key0 [31:0] = TX/RX MIC key [31:0]
* key1 [31:0] = reserved
* key2 [31:0] = TX/RX MIC key [63:32]
* key3 [31:0] = reserved
* key4 [31:0] = reserved
*
* Upper layer code will call this function separately
* for TX and RX keys when these registers offsets are
* used.
*/
u32 mic0, mic2;
mic0 = get_unaligned_le32(k->kv_mic + 0);
mic2 = get_unaligned_le32(k->kv_mic + 4);
/* Write MIC key[31:0] */
REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
/* Write MIC key[63:32] */
REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
/* Write TX[63:32] and keyType(reserved) */
REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
AR_KEYTABLE_TYPE_CLR);
}
/* MAC address registers are reserved for the MIC entry */
REG_WRITE(ah, AR_KEYTABLE_MAC0(micentry), 0);
REG_WRITE(ah, AR_KEYTABLE_MAC1(micentry), 0);
/*
* Write the correct (un-inverted) key[47:0] last to enable
* TKIP now that all other registers are set with correct
* values.
*/
REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
} else {
/* Write key[47:0] */
REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
/* Write key[95:48] */
REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
/* Write key[127:96] and key type */
REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
/* Write MAC address for the entry */
(void) ath_hw_keysetmac(common, entry, mac);
}
return true;
}
static int ath_setkey_tkip(struct ath_common *common, u16 keyix, const u8 *key,
struct ath_keyval *hk, const u8 *addr,
bool authenticator)
{
const u8 *key_rxmic;
const u8 *key_txmic;
key_txmic = key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
key_rxmic = key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
if (addr == NULL) {
/*
* Group key installation - only two key cache entries are used
* regardless of splitmic capability since group key is only
* used either for TX or RX.
*/
if (authenticator) {
memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_mic));
} else {
memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
memcpy(hk->kv_txmic, key_rxmic, sizeof(hk->kv_mic));
}
return ath_hw_set_keycache_entry(common, keyix, hk, addr);
}
if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
/* TX and RX keys share the same key cache entry. */
memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_txmic));
return ath_hw_set_keycache_entry(common, keyix, hk, addr);
}
/* Separate key cache entries for TX and RX */
/* TX key goes at first index, RX key at +32. */
memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
if (!ath_hw_set_keycache_entry(common, keyix, hk, NULL)) {
/* TX MIC entry failed. No need to proceed further */
ath_err(common, "Setting TX MIC Key Failed\n");
return 0;
}
memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
/* XXX delete tx key on failure? */
return ath_hw_set_keycache_entry(common, keyix + 32, hk, addr);
}
static int ath_reserve_key_cache_slot_tkip(struct ath_common *common)
{
int i;
for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
if (test_bit(i, common->keymap) ||
test_bit(i + 64, common->keymap))
continue; /* At least one part of TKIP key allocated */
if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) &&
(test_bit(i + 32, common->keymap) ||
test_bit(i + 64 + 32, common->keymap)))
continue; /* At least one part of TKIP key allocated */
/* Found a free slot for a TKIP key */
return i;
}
return -1;
}
static int ath_reserve_key_cache_slot(struct ath_common *common,
u32 cipher)
{
int i;
if (cipher == WLAN_CIPHER_SUITE_TKIP)
return ath_reserve_key_cache_slot_tkip(common);
/* First, try to find slots that would not be available for TKIP. */
if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
for (i = IEEE80211_WEP_NKID; i < common->keymax / 4; i++) {
if (!test_bit(i, common->keymap) &&
(test_bit(i + 32, common->keymap) ||
test_bit(i + 64, common->keymap) ||
test_bit(i + 64 + 32, common->keymap)))
return i;
if (!test_bit(i + 32, common->keymap) &&
(test_bit(i, common->keymap) ||
test_bit(i + 64, common->keymap) ||
test_bit(i + 64 + 32, common->keymap)))
return i + 32;
if (!test_bit(i + 64, common->keymap) &&
(test_bit(i , common->keymap) ||
test_bit(i + 32, common->keymap) ||
test_bit(i + 64 + 32, common->keymap)))
return i + 64;
if (!test_bit(i + 64 + 32, common->keymap) &&
(test_bit(i, common->keymap) ||
test_bit(i + 32, common->keymap) ||
test_bit(i + 64, common->keymap)))
return i + 64 + 32;
}
} else {
for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
if (!test_bit(i, common->keymap) &&
test_bit(i + 64, common->keymap))
return i;
if (test_bit(i, common->keymap) &&
!test_bit(i + 64, common->keymap))
return i + 64;
}
}
/* No partially used TKIP slots, pick any available slot */
for (i = IEEE80211_WEP_NKID; i < common->keymax; i++) {
/* Do not allow slots that could be needed for TKIP group keys
* to be used. This limitation could be removed if we know that
* TKIP will not be used. */
if (i >= 64 && i < 64 + IEEE80211_WEP_NKID)
continue;
if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
if (i >= 32 && i < 32 + IEEE80211_WEP_NKID)
continue;
if (i >= 64 + 32 && i < 64 + 32 + IEEE80211_WEP_NKID)
continue;
}
if (!test_bit(i, common->keymap))
return i; /* Found a free slot for a key */
}
/* No free slot found */
return -1;
}
/*
* Configure encryption in the HW.
*/
int ath_key_config(struct ath_common *common,
struct ieee80211_vif *vif,
struct ieee80211_sta *sta,
struct ieee80211_key_conf *key)
{
struct ath_keyval hk;
const u8 *mac = NULL;
u8 gmac[ETH_ALEN];
int ret = 0;
int idx;
memset(&hk, 0, sizeof(hk));
switch (key->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
hk.kv_type = ATH_CIPHER_WEP;
break;
case WLAN_CIPHER_SUITE_TKIP:
hk.kv_type = ATH_CIPHER_TKIP;
break;
case WLAN_CIPHER_SUITE_CCMP:
hk.kv_type = ATH_CIPHER_AES_CCM;
break;
default:
return -EOPNOTSUPP;
}
hk.kv_len = key->keylen;
memcpy(hk.kv_val, key->key, key->keylen);
if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
switch (vif->type) {
case NL80211_IFTYPE_AP:
memcpy(gmac, vif->addr, ETH_ALEN);
gmac[0] |= 0x01;
mac = gmac;
idx = ath_reserve_key_cache_slot(common, key->cipher);
break;
case NL80211_IFTYPE_ADHOC:
if (!sta) {
idx = key->keyidx;
break;
}
memcpy(gmac, sta->addr, ETH_ALEN);
gmac[0] |= 0x01;
mac = gmac;
idx = ath_reserve_key_cache_slot(common, key->cipher);
break;
default:
idx = key->keyidx;
break;
}
} else if (key->keyidx) {
if (WARN_ON(!sta))
return -EOPNOTSUPP;
mac = sta->addr;
if (vif->type != NL80211_IFTYPE_AP) {
/* Only keyidx 0 should be used with unicast key, but
* allow this for client mode for now. */
idx = key->keyidx;
} else
return -EIO;
} else {
if (WARN_ON(!sta))
return -EOPNOTSUPP;
mac = sta->addr;
idx = ath_reserve_key_cache_slot(common, key->cipher);
}
if (idx < 0)
return -ENOSPC; /* no free key cache entries */
if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
ret = ath_setkey_tkip(common, idx, key->key, &hk, mac,
vif->type == NL80211_IFTYPE_AP);
else
ret = ath_hw_set_keycache_entry(common, idx, &hk, mac);
if (!ret)
return -EIO;
set_bit(idx, common->keymap);
if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
set_bit(idx + 64, common->keymap);
set_bit(idx, common->tkip_keymap);
set_bit(idx + 64, common->tkip_keymap);
if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
set_bit(idx + 32, common->keymap);
set_bit(idx + 64 + 32, common->keymap);
set_bit(idx + 32, common->tkip_keymap);
set_bit(idx + 64 + 32, common->tkip_keymap);
}
}
return idx;
}
EXPORT_SYMBOL(ath_key_config);
/*
* Delete Key.
*/
void ath_key_delete(struct ath_common *common, struct ieee80211_key_conf *key)
{
ath_hw_keyreset(common, key->hw_key_idx);
if (key->hw_key_idx < IEEE80211_WEP_NKID)
return;
clear_bit(key->hw_key_idx, common->keymap);
if (key->cipher != WLAN_CIPHER_SUITE_TKIP)
return;
clear_bit(key->hw_key_idx + 64, common->keymap);
clear_bit(key->hw_key_idx, common->tkip_keymap);
clear_bit(key->hw_key_idx + 64, common->tkip_keymap);
if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
ath_hw_keyreset(common, key->hw_key_idx + 32);
clear_bit(key->hw_key_idx + 32, common->keymap);
clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
clear_bit(key->hw_key_idx + 32, common->tkip_keymap);
clear_bit(key->hw_key_idx + 64 + 32, common->tkip_keymap);
}
}
EXPORT_SYMBOL(ath_key_delete);
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