net/mac80211/wpa.c - kernel/msm-4.9 - Gitiles

 /*
  * 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_txrx_result
 ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_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->alg != ALG_TKIP || skb->len < 24 ||
 	    !WLAN_FC_DATA_PRESENT(fc))
 		return TXRX_CONTINUE;

 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
 		return TXRX_DROP;

 	if (!tx->key->force_sw_encrypt &&
 	    !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
 	    !(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
 	    !wpa_test) {
 		/* hwaccel - with no need for preallocated room for Michael MIC
 		 */
 		return TXRX_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 TXRX_DROP;
 		}
 	}

 #if 0
 	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
 #else
 	authenticator = 1;
 #endif
 	key = &tx->key->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 TXRX_CONTINUE;
 }


 ieee80211_txrx_result
 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_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;

 	fc = rx->fc;

 	/*
 	 * No way to verify the MIC if the hardware stripped it
 	 */
 	if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
 		return TXRX_CONTINUE;

 	if (!rx->key || rx->key->alg != ALG_TKIP ||
 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
 		return TXRX_CONTINUE;

 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 	    !rx->key->force_sw_encrypt) {
 		if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
 			if (skb->len < MICHAEL_MIC_LEN)
 				return TXRX_DROP;
 		}
 		/* Need to verify Michael MIC sometimes in software even when
 		 * hwaccel is used. Atheros ar5212: fragmented frames and QoS
 		 * frames. */
 		if (!(rx->flags & IEEE80211_TXRXD_FRAGMENTED) && !wpa_test)
 			goto remove_mic;
 	}

 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
 	    || data_len < MICHAEL_MIC_LEN)
 		return TXRX_DROP;

 	data_len -= MICHAEL_MIC_LEN;

 #if 0
 	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
 #else
 	authenticator = 1;
 #endif
 	key = &rx->key->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_TXRXD_RXRA_MATCH))
 			return TXRX_DROP;

 		printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
 		       MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));

 		mac80211_ev_michael_mic_failure(rx->dev, rx->key->keyidx,
 						(void *) skb->data);
 		return TXRX_DROP;
 	}

  remove_mic:
 	/* remove Michael MIC from payload */
 	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);

 	return TXRX_CONTINUE;
 }


 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
 			    struct sk_buff *skb, int test)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_key *key = tx->key;
 	int hdrlen, len, tailneed;
 	u16 fc;
 	u8 *pos;

 	fc = le16_to_cpu(hdr->frame_control);
 	hdrlen = ieee80211_get_hdrlen(fc);
 	len = skb->len - hdrlen;

 	tailneed = !tx->key->force_sw_encrypt ? 0 : 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.iv16++;
 	if (key->u.tkip.iv16 == 0)
 		key->u.tkip.iv32++;

 	if (!tx->key->force_sw_encrypt) {
 		u32 flags = tx->local->hw.flags;
 		hdr = (struct ieee80211_hdr *)skb->data;

 		/* hwaccel - with preallocated room for IV */
 		ieee80211_tkip_add_iv(pos, key,
 				      (u8) (key->u.tkip.iv16 >> 8),
 				      (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
 					    0x7f),
 				      (u8) key->u.tkip.iv16);

 		if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
 			ieee80211_tkip_gen_rc4key(key, hdr->addr2,
 						  tx->u.tx.control->tkip_key);
 		else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
 			if (key->u.tkip.iv16 == 0 ||
 			    !key->u.tkip.tx_initialized) {
 				ieee80211_tkip_gen_phase1key(key, hdr->addr2,
 					    (u16 *)tx->u.tx.control->tkip_key);
 				key->u.tkip.tx_initialized = 1;
 				tx->u.tx.control->flags |=
 					    IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
 			} else
 				tx->u.tx.control->flags &=
 					    ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
 		}

 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 		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_txrx_result
 ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 	u16 fc;
 	struct ieee80211_key *key = tx->key;
 	struct sk_buff *skb = tx->skb;
 	int wpa_test = 0, test = 0;

 	fc = le16_to_cpu(hdr->frame_control);

 	if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc))
 		return TXRX_CONTINUE;

 	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
 	tx->u.tx.control->iv_len = TKIP_IV_LEN;
 	ieee80211_tx_set_iswep(tx);

 	if (!tx->key->force_sw_encrypt &&
 	    !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
 	    !wpa_test) {
 		/* hwaccel - with no need for preallocated room for IV/ICV */
 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 		return TXRX_CONTINUE;
 	}

 	if (tkip_encrypt_skb(tx, skb, test) < 0)
 		return TXRX_DROP;

 	if (tx->u.tx.extra_frag) {
 		int i;
 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 			if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 			    < 0)
 				return TXRX_DROP;
 		}
 	}

 	return TXRX_CONTINUE;
 }


 ieee80211_txrx_result
 ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_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;

 	fc = le16_to_cpu(hdr->frame_control);
 	hdrlen = ieee80211_get_hdrlen(fc);

 	if (!rx->key || rx->key->alg != ALG_TKIP ||
 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
 	    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 		return TXRX_CONTINUE;

 	if (!rx->sta || skb->len - hdrlen < 12)
 		return TXRX_DROP;

 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 	    !rx->key->force_sw_encrypt) {
 		if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
 			/* Hardware takes care of all processing, including
 			 * replay protection, so no need to continue here. */
 			return TXRX_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,
 					  hwaccel, rx->u.rx.queue);
 	if (res != TKIP_DECRYPT_OK || wpa_test) {
 		printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
 		       MAC_FMT " (res=%d)\n",
 		       rx->dev->name, MAC_ARG(rx->sta->addr), res);
 		return TXRX_DROP;
 	}

 	/* 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 TXRX_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_txrx_data *tx,
 			    struct sk_buff *skb, int test)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_key *key = tx->key;
 	int hdrlen, len, tailneed;
 	u16 fc;
 	u8 *pos, *pn, *b_0, *aad, *scratch;
 	int i;

 	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;

 	tailneed = !key->force_sw_encrypt ? 0 : 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->keyidx);

 	if (!key->force_sw_encrypt) {
 		/* hwaccel - with preallocated room for CCMP header */
 		tx->u.tx.control->key_idx = key->hw_key_idx;
 		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_txrx_result
 ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 	struct ieee80211_key *key = tx->key;
 	u16 fc;
 	struct sk_buff *skb = tx->skb;
 	int test = 0;

 	fc = le16_to_cpu(hdr->frame_control);

 	if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc))
 		return TXRX_CONTINUE;

 	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
 	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
 	ieee80211_tx_set_iswep(tx);

 	if (!tx->key->force_sw_encrypt &&
 	    !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
 		/* hwaccel - with no need for preallocated room for CCMP "
 		 * header or MIC fields */
 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 		return TXRX_CONTINUE;
 	}

 	if (ccmp_encrypt_skb(tx, skb, test) < 0)
 		return TXRX_DROP;

 	if (tx->u.tx.extra_frag) {
 		int i;

 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 			if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 			    < 0)
 				return TXRX_DROP;
 		}
 	}

 	return TXRX_CONTINUE;
 }


 ieee80211_txrx_result
 ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_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;

 	fc = le16_to_cpu(hdr->frame_control);
 	hdrlen = ieee80211_get_hdrlen(fc);

 	if (!key || key->alg != ALG_CCMP ||
 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
 	    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 		return TXRX_CONTINUE;

 	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
 	if (!rx->sta || data_len < 0)
 		return TXRX_DROP;

 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 	    !key->force_sw_encrypt &&
 	    !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
 		return TXRX_CONTINUE;

 	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);

 	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
 #ifdef CONFIG_MAC80211_DEBUG
 		u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
 		printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
 		       MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
 		       "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
 		       MAC_ARG(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 TXRX_DROP;
 	}

 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 	    !key->force_sw_encrypt) {
 		/* hwaccel has already decrypted frame and verified MIC */
 	} else {
 		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)) {
 			printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
 			       "frame from " MAC_FMT "\n", rx->dev->name,
 			       MAC_ARG(rx->sta->addr));
 			return TXRX_DROP;
 		}
 	}

 	memcpy(key->u.ccmp.rx_pn[rx->u.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 TXRX_CONTINUE;
 }
	/*
	* 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_txrx_result
	ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_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->alg != ALG_TKIP \|\| skb->len < 24 \|\|
	!WLAN_FC_DATA_PRESENT(fc))
	return TXRX_CONTINUE;

	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
	return TXRX_DROP;

	if (!tx->key->force_sw_encrypt &&
	!(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
	!(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
	!wpa_test) {
	/* hwaccel - with no need for preallocated room for Michael MIC
	*/
	return TXRX_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 TXRX_DROP;
	}
	}

	#if 0
	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
	#else
	authenticator = 1;
	#endif
	key = &tx->key->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 TXRX_CONTINUE;
	}


	ieee80211_txrx_result
	ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_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;

	fc = rx->fc;

	/*
	* No way to verify the MIC if the hardware stripped it
	*/
	if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
	return TXRX_CONTINUE;

	if (!rx->key \|\| rx->key->alg != ALG_TKIP \|\|
	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\| !WLAN_FC_DATA_PRESENT(fc))
	return TXRX_CONTINUE;

	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	!rx->key->force_sw_encrypt) {
	if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
	if (skb->len < MICHAEL_MIC_LEN)
	return TXRX_DROP;
	}
	/* Need to verify Michael MIC sometimes in software even when
	* hwaccel is used. Atheros ar5212: fragmented frames and QoS
	* frames. */
	if (!(rx->flags & IEEE80211_TXRXD_FRAGMENTED) && !wpa_test)
	goto remove_mic;
	}

	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
	\|\| data_len < MICHAEL_MIC_LEN)
	return TXRX_DROP;

	data_len -= MICHAEL_MIC_LEN;

	#if 0
	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
	#else
	authenticator = 1;
	#endif
	key = &rx->key->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_TXRXD_RXRA_MATCH))
	return TXRX_DROP;

	printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
	MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));

	mac80211_ev_michael_mic_failure(rx->dev, rx->key->keyidx,
	(void *) skb->data);
	return TXRX_DROP;
	}

	remove_mic:
	/* remove Michael MIC from payload */
	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);

	return TXRX_CONTINUE;
	}


	static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
	struct sk_buff *skb, int test)
	{
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	struct ieee80211_key *key = tx->key;
	int hdrlen, len, tailneed;
	u16 fc;
	u8 *pos;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	len = skb->len - hdrlen;

	tailneed = !tx->key->force_sw_encrypt ? 0 : 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.iv16++;
	if (key->u.tkip.iv16 == 0)
	key->u.tkip.iv32++;

	if (!tx->key->force_sw_encrypt) {
	u32 flags = tx->local->hw.flags;
	hdr = (struct ieee80211_hdr *)skb->data;

	/* hwaccel - with preallocated room for IV */
	ieee80211_tkip_add_iv(pos, key,
	(u8) (key->u.tkip.iv16 >> 8),
	(u8) (((key->u.tkip.iv16 >> 8) \| 0x20) &
	0x7f),
	(u8) key->u.tkip.iv16);

	if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
	ieee80211_tkip_gen_rc4key(key, hdr->addr2,
	tx->u.tx.control->tkip_key);
	else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
	if (key->u.tkip.iv16 == 0 \|\|
	!key->u.tkip.tx_initialized) {
	ieee80211_tkip_gen_phase1key(key, hdr->addr2,
	(u16 *)tx->u.tx.control->tkip_key);
	key->u.tkip.tx_initialized = 1;
	tx->u.tx.control->flags \|=
	IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
	} else
	tx->u.tx.control->flags &=
	~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
	}

	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
	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_txrx_result
	ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
	{
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) tx->skb->data;
	u16 fc;
	struct ieee80211_key *key = tx->key;
	struct sk_buff *skb = tx->skb;
	int wpa_test = 0, test = 0;

	fc = le16_to_cpu(hdr->frame_control);

	if (!key \|\| key->alg != ALG_TKIP \|\| !WLAN_FC_DATA_PRESENT(fc))
	return TXRX_CONTINUE;

	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
	tx->u.tx.control->iv_len = TKIP_IV_LEN;
	ieee80211_tx_set_iswep(tx);

	if (!tx->key->force_sw_encrypt &&
	!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
	!wpa_test) {
	/* hwaccel - with no need for preallocated room for IV/ICV */
	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
	return TXRX_CONTINUE;
	}

	if (tkip_encrypt_skb(tx, skb, test) < 0)
	return TXRX_DROP;

	if (tx->u.tx.extra_frag) {
	int i;
	for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
	if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
	< 0)
	return TXRX_DROP;
	}
	}

	return TXRX_CONTINUE;
	}


	ieee80211_txrx_result
	ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_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;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);

	if (!rx->key \|\| rx->key->alg != ALG_TKIP \|\|
	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\|
	(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
	return TXRX_CONTINUE;

	if (!rx->sta \|\| skb->len - hdrlen < 12)
	return TXRX_DROP;

	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	!rx->key->force_sw_encrypt) {
	if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
	/* Hardware takes care of all processing, including
	* replay protection, so no need to continue here. */
	return TXRX_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,
	hwaccel, rx->u.rx.queue);
	if (res != TKIP_DECRYPT_OK \|\| wpa_test) {
	printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
	MAC_FMT " (res=%d)\n",
	rx->dev->name, MAC_ARG(rx->sta->addr), res);
	return TXRX_DROP;
	}

	/* 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 TXRX_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_txrx_data *tx,
	struct sk_buff *skb, int test)
	{
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	struct ieee80211_key *key = tx->key;
	int hdrlen, len, tailneed;
	u16 fc;
	u8 pos, pn, b_0, aad, *scratch;
	int i;

	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;

	tailneed = !key->force_sw_encrypt ? 0 : 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->keyidx);

	if (!key->force_sw_encrypt) {
	/* hwaccel - with preallocated room for CCMP header */
	tx->u.tx.control->key_idx = key->hw_key_idx;
	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_txrx_result
	ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
	{
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) tx->skb->data;
	struct ieee80211_key *key = tx->key;
	u16 fc;
	struct sk_buff *skb = tx->skb;
	int test = 0;

	fc = le16_to_cpu(hdr->frame_control);

	if (!key \|\| key->alg != ALG_CCMP \|\| !WLAN_FC_DATA_PRESENT(fc))
	return TXRX_CONTINUE;

	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
	ieee80211_tx_set_iswep(tx);

	if (!tx->key->force_sw_encrypt &&
	!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
	/* hwaccel - with no need for preallocated room for CCMP "
	* header or MIC fields */
	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
	return TXRX_CONTINUE;
	}

	if (ccmp_encrypt_skb(tx, skb, test) < 0)
	return TXRX_DROP;

	if (tx->u.tx.extra_frag) {
	int i;

	for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
	if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
	< 0)
	return TXRX_DROP;
	}
	}

	return TXRX_CONTINUE;
	}


	ieee80211_txrx_result
	ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_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;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);

	if (!key \|\| key->alg != ALG_CCMP \|\|
	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\|
	(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
	return TXRX_CONTINUE;

	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
	if (!rx->sta \|\| data_len < 0)
	return TXRX_DROP;

	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	!key->force_sw_encrypt &&
	!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
	return TXRX_CONTINUE;

	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);

	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
	#ifdef CONFIG_MAC80211_DEBUG
	u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
	printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
	MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
	"%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
	MAC_ARG(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 TXRX_DROP;
	}

	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	!key->force_sw_encrypt) {
	/* hwaccel has already decrypted frame and verified MIC */
	} else {
	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)) {
	printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
	"frame from " MAC_FMT "\n", rx->dev->name,
	MAC_ARG(rx->sta->addr));
	return TXRX_DROP;
	}
	}

	memcpy(key->u.ccmp.rx_pn[rx->u.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 TXRX_CONTINUE;
	}