linux/net/mac80211/wpa.c

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/*
* Copyright 2002-2004, Instant802 Networks, Inc.
*
* 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/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/compiler.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "michael.h"
#include "tkip.h"
#include "aes_ccm.h"
#include "wpa.h"
static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
u8 *qos_tid, u8 **data, size_t *data_len)
{
struct ieee80211_hdr *hdr;
size_t hdrlen;
u16 fc;
int a4_included;
u8 *pos;
hdr = (struct ieee80211_hdr *) skb->data;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = 24;
if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
hdrlen += ETH_ALEN;
*sa = hdr->addr4;
*da = hdr->addr3;
} else if (fc & IEEE80211_FCTL_FROMDS) {
*sa = hdr->addr3;
*da = hdr->addr1;
} else if (fc & IEEE80211_FCTL_TODS) {
*sa = hdr->addr2;
*da = hdr->addr3;
} else {
*sa = hdr->addr2;
*da = hdr->addr1;
}
if (fc & 0x80)
hdrlen += 2;
*data = skb->data + hdrlen;
*data_len = skb->len - hdrlen;
a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
fc & IEEE80211_STYPE_QOS_DATA) {
pos = (u8 *) &hdr->addr4;
if (a4_included)
pos += 6;
*qos_tid = pos[0] & 0x0f;
*qos_tid |= 0x80; /* qos_included flag */
} else
*qos_tid = 0;
return skb->len < hdrlen ? -1 : 0;
}
ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
{
u8 *data, *sa, *da, *key, *mic, qos_tid;
size_t data_len;
u16 fc;
struct sk_buff *skb = tx->skb;
int authenticator;
int wpa_test = 0;
fc = tx->fc;
if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
!WLAN_FC_DATA_PRESENT(fc))
return TX_CONTINUE;
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
return TX_DROP;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->flags & IEEE80211_TX_FRAGMENTED) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
!wpa_test) {
/* hwaccel - with no need for preallocated room for Michael MIC
*/
return TX_CONTINUE;
}
if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
MICHAEL_MIC_LEN + TKIP_ICV_LEN,
GFP_ATOMIC))) {
printk(KERN_DEBUG "%s: failed to allocate more memory "
"for Michael MIC\n", tx->dev->name);
return TX_DROP;
}
}
#if 0
authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
#else
authenticator = 1;
#endif
key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
mic = skb_put(skb, MICHAEL_MIC_LEN);
michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
{
u8 *data, *sa, *da, *key = NULL, qos_tid;
size_t data_len;
u16 fc;
u8 mic[MICHAEL_MIC_LEN];
struct sk_buff *skb = rx->skb;
int authenticator = 1, wpa_test = 0;
DECLARE_MAC_BUF(mac);
fc = rx->fc;
/*
* No way to verify the MIC if the hardware stripped it
*/
if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
return RX_CONTINUE;
if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
return RX_CONTINUE;
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
|| data_len < MICHAEL_MIC_LEN)
return RX_DROP_UNUSABLE;
data_len -= MICHAEL_MIC_LEN;
#if 0
authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
#else
authenticator = 1;
#endif
key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_DROP_UNUSABLE;
printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
"%s\n", rx->dev->name, print_mac(mac, sa));
mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
(void *) skb->data);
return RX_DROP_UNUSABLE;
}
/* remove Michael MIC from payload */
skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
/* update IV in key information to be able to detect replays */
rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
return RX_CONTINUE;
}
static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, len, tailneed;
u16 fc;
u8 *pos;
info->control.icv_len = TKIP_ICV_LEN;
info->control.iv_len = TKIP_IV_LEN;
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
/* hwaccel - with no need for preallocated room for IV/ICV */
info->control.hw_key = &tx->key->conf;
return TX_CONTINUE;
}
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
len = skb->len - hdrlen;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tailneed = 0;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
else
tailneed = TKIP_ICV_LEN;
if ((skb_headroom(skb) < TKIP_IV_LEN ||
skb_tailroom(skb) < tailneed)) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
GFP_ATOMIC)))
return -1;
}
pos = skb_push(skb, TKIP_IV_LEN);
memmove(pos, pos + TKIP_IV_LEN, hdrlen);
pos += hdrlen;
/* Increase IV for the frame */
key->u.tkip.tx.iv16++;
if (key->u.tkip.tx.iv16 == 0)
key->u.tkip.tx.iv32++;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
hdr = (struct ieee80211_hdr *)skb->data;
/* hwaccel - with preallocated room for IV */
ieee80211_tkip_add_iv(pos, key,
(u8) (key->u.tkip.tx.iv16 >> 8),
(u8) (((key->u.tkip.tx.iv16 >> 8) | 0x20) &
0x7f),
(u8) key->u.tkip.tx.iv16);
info->control.hw_key = &tx->key->conf;
return 0;
}
/* Add room for ICV */
skb_put(skb, TKIP_ICV_LEN);
hdr = (struct ieee80211_hdr *) skb->data;
ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
key, pos, len, hdr->addr2);
return 0;
}
ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
ieee80211_tx_set_protected(tx);
if (tkip_encrypt_skb(tx, skb) < 0)
return TX_DROP;
if (tx->extra_frag) {
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 0)
return TX_DROP;
}
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
u16 fc;
int hdrlen, res, hwaccel = 0, wpa_test = 0;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
DECLARE_MAC_BUF(mac);
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return RX_CONTINUE;
if (!rx->sta || skb->len - hdrlen < 12)
return RX_DROP_UNUSABLE;
if (rx->status->flag & RX_FLAG_DECRYPTED) {
if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
/*
* Hardware took care of all processing, including
* replay protection, and stripped the ICV/IV so
* we cannot do any checks here.
*/
return RX_CONTINUE;
}
/* let TKIP code verify IV, but skip decryption */
hwaccel = 1;
}
res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
key, skb->data + hdrlen,
skb->len - hdrlen, rx->sta->addr,
hdr->addr1, hwaccel, rx->queue,
&rx->tkip_iv32,
&rx->tkip_iv16);
if (res != TKIP_DECRYPT_OK || wpa_test) {
#ifdef CONFIG_MAC80211_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
"frame from %s (res=%d)\n", rx->dev->name,
print_mac(mac, rx->sta->addr), res);
#endif /* CONFIG_MAC80211_DEBUG */
return RX_DROP_UNUSABLE;
}
/* Trim ICV */
skb_trim(skb, skb->len - TKIP_ICV_LEN);
/* Remove IV */
memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
skb_pull(skb, TKIP_IV_LEN);
return RX_CONTINUE;
}
static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
int encrypted)
{
u16 fc;
int a4_included, qos_included;
u8 qos_tid, *fc_pos, *data, *sa, *da;
int len_a;
size_t data_len;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
fc_pos = (u8 *) &hdr->frame_control;
fc = fc_pos[0] ^ (fc_pos[1] << 8);
a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
if (qos_tid & 0x80) {
qos_included = 1;
qos_tid &= 0x0f;
} else
qos_included = 0;
/* First block, b_0 */
b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
/* Nonce: QoS Priority | A2 | PN */
b_0[1] = qos_tid;
memcpy(&b_0[2], hdr->addr2, 6);
memcpy(&b_0[8], pn, CCMP_PN_LEN);
/* l(m) */
b_0[14] = (data_len >> 8) & 0xff;
b_0[15] = data_len & 0xff;
/* AAD (extra authenticate-only data) / masked 802.11 header
* FC | A1 | A2 | A3 | SC | [A4] | [QC] */
len_a = a4_included ? 28 : 22;
if (qos_included)
len_a += 2;
aad[0] = 0; /* (len_a >> 8) & 0xff; */
aad[1] = len_a & 0xff;
/* Mask FC: zero subtype b4 b5 b6 */
aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
/* Retry, PwrMgt, MoreData; set Protected */
aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
memcpy(&aad[4], &hdr->addr1, 18);
/* Mask Seq#, leave Frag# */
aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
aad[23] = 0;
if (a4_included) {
memcpy(&aad[24], hdr->addr4, 6);
aad[30] = 0;
aad[31] = 0;
} else
memset(&aad[24], 0, 8);
if (qos_included) {
u8 *dpos = &aad[a4_included ? 30 : 24];
/* Mask QoS Control field */
dpos[0] = qos_tid;
dpos[1] = 0;
}
}
static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
{
hdr[0] = pn[5];
hdr[1] = pn[4];
hdr[2] = 0;
hdr[3] = 0x20 | (key_id << 6);
hdr[4] = pn[3];
hdr[5] = pn[2];
hdr[6] = pn[1];
hdr[7] = pn[0];
}
static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
{
pn[0] = hdr[7];
pn[1] = hdr[6];
pn[2] = hdr[5];
pn[3] = hdr[4];
pn[4] = hdr[1];
pn[5] = hdr[0];
return (hdr[3] >> 6) & 0x03;
}
static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, len, tailneed;
u16 fc;
u8 *pos, *pn, *b_0, *aad, *scratch;
int i;
info->control.icv_len = CCMP_MIC_LEN;
info->control.iv_len = CCMP_HDR_LEN;
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
/* hwaccel - with no need for preallocated room for CCMP "
* header or MIC fields */
info->control.hw_key = &tx->key->conf;
return TX_CONTINUE;
}
scratch = key->u.ccmp.tx_crypto_buf;
b_0 = scratch + 3 * AES_BLOCK_LEN;
aad = scratch + 4 * AES_BLOCK_LEN;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
len = skb->len - hdrlen;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tailneed = 0;
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
else
tailneed = CCMP_MIC_LEN;
if ((skb_headroom(skb) < CCMP_HDR_LEN ||
skb_tailroom(skb) < tailneed)) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
GFP_ATOMIC)))
return -1;
}
pos = skb_push(skb, CCMP_HDR_LEN);
memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
hdr = (struct ieee80211_hdr *) pos;
pos += hdrlen;
/* PN = PN + 1 */
pn = key->u.ccmp.tx_pn;
for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
pn[i]++;
if (pn[i])
break;
}
ccmp_pn2hdr(pos, pn, key->conf.keyidx);
[MAC80211]: rework key handling This moves all the key handling code out from ieee80211_ioctl.c into key.c and also does the following changes including documentation updates in mac80211.h: 1) Turn off hardware acceleration for keys when the interface is down. This is necessary because otherwise monitor interfaces could be decrypting frames for other interfaces that are down at the moment. Also, it should go some way towards better suspend/resume support, in any case the routines used here could be used for that as well. Additionally, this makes the driver interface nicer, keys for a specific local MAC address are only ever present while an interface with that MAC address is enabled. 2) Change driver set_key() callback interface to allow only return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all other return values. This allows debugging the stack when a driver notices it's handed a key while it is down. 3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE. 4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we want to use it, we'll use DISABLE_KEY for each key. It is hard to use REMOVE_ALL_KEYS because we can handle multiple virtual interfaces with different key configuration, so we'd have to keep track of a lot of state for this and that isn't worth it. 5) Warn when disabling a key fails, it musn't. 6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself. 7) Tell driver that a (non-WEP) key is used only for transmission by using an all-zeroes station MAC address when configuring. 8) Change the set_key() callback to have access to the local MAC address the key is being added for. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Michael Wu <flamingice@sourmilk.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-28 21:01:55 +00:00
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
/* hwaccel - with preallocated room for CCMP header */
info->control.hw_key = &tx->key->conf;
return 0;
}
pos += CCMP_HDR_LEN;
ccmp_special_blocks(skb, pn, b_0, aad, 0);
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
pos, skb_put(skb, CCMP_MIC_LEN));
return 0;
}
ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
ieee80211_tx_set_protected(tx);
if (ccmp_encrypt_skb(tx, skb) < 0)
return TX_DROP;
if (tx->extra_frag) {
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
return TX_DROP;
}
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
u16 fc;
int hdrlen;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
u8 pn[CCMP_PN_LEN];
int data_len;
DECLARE_MAC_BUF(mac);
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return RX_CONTINUE;
data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
(rx->status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
#ifdef CONFIG_MAC80211_DEBUG
u8 *ppn = key->u.ccmp.rx_pn[rx->queue];
printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
"%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
"%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
print_mac(mac, rx->sta->addr),
pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
#endif /* CONFIG_MAC80211_DEBUG */
key->u.ccmp.replays++;
return RX_DROP_UNUSABLE;
}
if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
u8 *scratch, *b_0, *aad;
scratch = key->u.ccmp.rx_crypto_buf;
b_0 = scratch + 3 * AES_BLOCK_LEN;
aad = scratch + 4 * AES_BLOCK_LEN;
ccmp_special_blocks(skb, pn, b_0, aad, 1);
if (ieee80211_aes_ccm_decrypt(
key->u.ccmp.tfm, scratch, b_0, aad,
skb->data + hdrlen + CCMP_HDR_LEN, data_len,
skb->data + skb->len - CCMP_MIC_LEN,
skb->data + hdrlen + CCMP_HDR_LEN)) {
#ifdef CONFIG_MAC80211_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: CCMP decrypt failed "
"for RX frame from %s\n", rx->dev->name,
print_mac(mac, rx->sta->addr));
#endif /* CONFIG_MAC80211_DEBUG */
return RX_DROP_UNUSABLE;
}
}
memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
/* Remove CCMP header and MIC */
skb_trim(skb, skb->len - CCMP_MIC_LEN);
memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
skb_pull(skb, CCMP_HDR_LEN);
return RX_CONTINUE;
}