From 3ea542d3c2862142ae511fac5ce2dfc7419dcc53 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 7 Jul 2011 18:58:00 +0200 Subject: [PATCH] mac80211: allow drivers to access key sequence counter 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 Signed-off-by: John W. Linville --- include/net/mac80211.h | 60 ++++++++++++++++++++++++++++++++++ net/mac80211/key.c | 74 ++++++++++++++++++++++++++++++++++++++++++ net/mac80211/key.h | 5 +-- 3 files changed, 137 insertions(+), 2 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 0aae7bc1eeae..84770cedae2d 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -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 diff --git a/net/mac80211/key.c b/net/mac80211/key.c index d930d4d4876d..739bee13e813 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -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); diff --git a/net/mac80211/key.h b/net/mac80211/key.h index beb9c20ff48c..86b216b01415 100644 --- a/net/mac80211/key.h +++ b/net/mac80211/key.h @@ -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 */ -- 2.30.2