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mac80211: allow drivers to access key sequence counter

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In order to implement GTK rekeying, the device needs
to be able to encrypt frames with the right PN/IV and
check the PN/IV in RX frames. To be able to tell it
about all those counters, we need to be able to get
them from mac80211, this adds the required API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2011-07-07 18:58:00 +02:00 committed by John W. Linville
parent 9e26297a56
commit 3ea542d3c2
3 changed files with 137 additions and 2 deletions
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60
include/net/mac80211.h
View File

@ -2591,6 +2591,66 @@ void ieee80211_get_tkip_p1k(struct ieee80211_key_conf *keyconf,
void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
struct sk_buff *skb, u8 *p2k);
/**
* struct ieee80211_key_seq - key sequence counter
*
* @tkip: TKIP data, containing IV32 and IV16 in host byte order
* @ccmp: PN data, most significant byte first (big endian,
* reverse order than in packet)
* @aes_cmac: PN data, most significant byte first (big endian,
* reverse order than in packet)
*/
struct ieee80211_key_seq {
union {
struct {
u32 iv32;
u16 iv16;
} tkip;
struct {
u8 pn[6];
} ccmp;
struct {
u8 pn[6];
} aes_cmac;
};
};
/**
* ieee80211_get_key_tx_seq - get key TX sequence counter
*
* @keyconf: the parameter passed with the set key
* @seq: buffer to receive the sequence data
*
* This function allows a driver to retrieve the current TX IV/PN
* for the given key. It must not be called if IV generation is
* offloaded to the device.
*
* Note that this function may only be called when no TX processing
* can be done concurrently, for example when queues are stopped
* and the stop has been synchronized.
*/
void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
struct ieee80211_key_seq *seq);
/**
* ieee80211_get_key_rx_seq - get key RX sequence counter
*
* @keyconf: the parameter passed with the set key
* @tid: The TID, or -1 for the management frame value (CCMP only);
* the value on TID 0 is also used for non-QoS frames. For
* CMAC, only TID 0 is valid.
* @seq: buffer to receive the sequence data
*
* This function allows a driver to retrieve the current RX IV/PNs
* for the given key. It must not be called if IV checking is done
* by the device and not by mac80211.
*
* Note that this function may only be called when no RX processing
* can be done concurrently.
*/
void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
int tid, struct ieee80211_key_seq *seq);
/**
* ieee80211_gtk_rekey_notify - notify userspace supplicant of rekeying
* @vif: virtual interface the rekeying was done on

74
net/mac80211/key.c
View File

@ -626,3 +626,77 @@ void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
struct ieee80211_key_seq *seq)
{
struct ieee80211_key *key;
u64 pn64;
if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
return;
key = container_of(keyconf, struct ieee80211_key, conf);
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_TKIP:
seq->tkip.iv32 = key->u.tkip.tx.iv32;
seq->tkip.iv16 = key->u.tkip.tx.iv16;
break;
case WLAN_CIPHER_SUITE_CCMP:
pn64 = atomic64_read(&key->u.ccmp.tx_pn);
seq->ccmp.pn[5] = pn64;
seq->ccmp.pn[4] = pn64 >> 8;
seq->ccmp.pn[3] = pn64 >> 16;
seq->ccmp.pn[2] = pn64 >> 24;
seq->ccmp.pn[1] = pn64 >> 32;
seq->ccmp.pn[0] = pn64 >> 40;
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
seq->ccmp.pn[5] = pn64;
seq->ccmp.pn[4] = pn64 >> 8;
seq->ccmp.pn[3] = pn64 >> 16;
seq->ccmp.pn[2] = pn64 >> 24;
seq->ccmp.pn[1] = pn64 >> 32;
seq->ccmp.pn[0] = pn64 >> 40;
break;
default:
WARN_ON(1);
}
}
EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
int tid, struct ieee80211_key_seq *seq)
{
struct ieee80211_key *key;
const u8 *pn;
key = container_of(keyconf, struct ieee80211_key, conf);
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_TKIP:
if (WARN_ON(tid < 0 || tid >= NUM_RX_DATA_QUEUES))
return;
seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
break;
case WLAN_CIPHER_SUITE_CCMP:
if (WARN_ON(tid < -1 || tid >= NUM_RX_DATA_QUEUES))
return;
if (tid < 0)
pn = key->u.ccmp.rx_pn[NUM_RX_DATA_QUEUES];
else
pn = key->u.ccmp.rx_pn[tid];
memcpy(seq->ccmp.pn, pn, CCMP_PN_LEN);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
if (WARN_ON(tid != 0))
return;
pn = key->u.aes_cmac.rx_pn;
memcpy(seq->aes_cmac.pn, pn, CMAC_PN_LEN);
break;
}
}
EXPORT_SYMBOL(ieee80211_get_key_rx_seq);

5
net/mac80211/key.h
View File

@ -28,6 +28,7 @@
#define CCMP_PN_LEN 6
#define TKIP_IV_LEN 8
#define TKIP_ICV_LEN 4
#define CMAC_PN_LEN 6
#define NUM_RX_DATA_QUEUES 16
@ -89,13 +90,13 @@ struct ieee80211_key {
* frames and the last counter is used with Robust
* Management frames.
*/
u8 rx_pn[NUM_RX_DATA_QUEUES + 1][6];
u8 rx_pn[NUM_RX_DATA_QUEUES + 1][CCMP_PN_LEN];
struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCCMPReplays */
} ccmp;
struct {
atomic64_t tx_pn;
u8 rx_pn[6];
u8 rx_pn[CMAC_PN_LEN];
struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCMACReplays */
u32 icverrors; /* dot11RSNAStatsCMACICVErrors */