[deliverable/linux.git] / net / mac80211 / wpa.c

/*
 * 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/iw_handler.h>

#include <net/mac80211.h>
#include "ieee80211_common.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->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->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->u.rx.ra_match)
			return TXRX_DROP;

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

		do {
			struct ieee80211_hdr *hdr;
			union iwreq_data wrqu;
			char *buf = kmalloc(128, GFP_ATOMIC);
			if (!buf)
				break;

			/* TODO: needed parameters: count, key type, TSC */
			hdr = (struct ieee80211_hdr *) skb->data;
			sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
				"keyid=%d %scast addr=" MAC_FMT ")",
				rx->key->keyidx,
				hdr->addr1[0] & 0x01 ? "broad" : "uni",
				MAC_ARG(hdr->addr2));
			memset(&wrqu, 0, sizeof(wrqu));
			wrqu.data.length = strlen(buf);
			wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
			kfree(buf);
		} while (0);

		if (!rx->local->apdev)
			return TXRX_DROP;

		ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
				  ieee80211_msg_michael_mic_failure);

		return TXRX_QUEUED;
	}

 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;
}
Commit	Line	Data
f0706e82 JB	1	/*
	2	* Copyright 2002-2004, Instant802 Networks, Inc.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/netdevice.h>
	10	#include <linux/types.h>
	11	#include <linux/slab.h>
	12	#include <linux/skbuff.h>
	13	#include <linux/compiler.h>
	14	#include <net/iw_handler.h>
	15
	16	#include <net/mac80211.h>
	17	#include "ieee80211_common.h"
	18	#include "ieee80211_i.h"
	19	#include "michael.h"
	20	#include "tkip.h"
	21	#include "aes_ccm.h"
	22	#include "wpa.h"
	23
	24	static int ieee80211_get_hdr_info(const struct sk_buff skb, u8 sa, u8 *da,
	25	u8 qos_tid, u8 data, size_t data_len)
	26	{
	27	struct ieee80211_hdr *hdr;
	28	size_t hdrlen;
	29	u16 fc;
	30	int a4_included;
	31	u8 *pos;
	32
	33	hdr = (struct ieee80211_hdr *) skb->data;
	34	fc = le16_to_cpu(hdr->frame_control);
	35
	36	hdrlen = 24;
	37	if ((fc & (IEEE80211_FCTL_FROMDS \| IEEE80211_FCTL_TODS)) ==
	38	(IEEE80211_FCTL_FROMDS \| IEEE80211_FCTL_TODS)) {
	39	hdrlen += ETH_ALEN;
	40	*sa = hdr->addr4;
	41	*da = hdr->addr3;
	42	} else if (fc & IEEE80211_FCTL_FROMDS) {
	43	*sa = hdr->addr3;
	44	*da = hdr->addr1;
	45	} else if (fc & IEEE80211_FCTL_TODS) {
	46	*sa = hdr->addr2;
	47	*da = hdr->addr3;
	48	} else {
	49	*sa = hdr->addr2;
	50	*da = hdr->addr1;
	51	}
	52
	53	if (fc & 0x80)
	54	hdrlen += 2;
	55
	56	*data = skb->data + hdrlen;
	57	*data_len = skb->len - hdrlen;
	58
	59	a4_included = (fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
	60	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS);
	61	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
	62	fc & IEEE80211_STYPE_QOS_DATA) {
	63	pos = (u8 *) &hdr->addr4;
	64	if (a4_included)
65	pos += 6;
66	*qos_tid = pos[0] & 0x0f;
67	qos_tid \|= 0x80; / qos_included flag */
68	} else
69	*qos_tid = 0;
70
71	return skb->len < hdrlen ? -1 : 0;
72	}
73
74
75	ieee80211_txrx_result
76	ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
77	{
78	u8 data, sa, da, key, *mic, qos_tid;
79	size_t data_len;
80	u16 fc;
81	struct sk_buff *skb = tx->skb;
82	int authenticator;
83	int wpa_test = 0;
84
85	fc = tx->fc;
86
87	if (!tx->key \|\| tx->key->alg != ALG_TKIP \|\| skb->len < 24 \|\|
88	!WLAN_FC_DATA_PRESENT(fc))
89	return TXRX_CONTINUE;
90
91	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
92	return TXRX_DROP;
93
94	if (!tx->key->force_sw_encrypt &&
95	!tx->fragmented &&
96	!(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
97	!wpa_test) {
98	/* hwaccel - with no need for preallocated room for Michael MIC
99	*/
100	return TXRX_CONTINUE;
101	}
102
103	if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
104	I802_DEBUG_INC(tx->local->tx_expand_skb_head);
105	if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
106	MICHAEL_MIC_LEN + TKIP_ICV_LEN,
107	GFP_ATOMIC))) {
108	printk(KERN_DEBUG "%s: failed to allocate more memory "
109	"for Michael MIC\n", tx->dev->name);
110	return TXRX_DROP;
111	}
112	}
113
114	#if 0
115	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
116	#else
117	authenticator = 1;
118	#endif
119	key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
120	ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
121	mic = skb_put(skb, MICHAEL_MIC_LEN);
122	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
123
124	return TXRX_CONTINUE;
125	}
126
127
128	ieee80211_txrx_result
129	ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
130	{
131	u8 data, sa, da, key = NULL, qos_tid;
132	size_t data_len;
133	u16 fc;
134	u8 mic[MICHAEL_MIC_LEN];
135	struct sk_buff *skb = rx->skb;
136	int authenticator = 1, wpa_test = 0;
137
138	fc = rx->fc;
139
3017b80b JB	140	/*
	141	* No way to verify the MIC if the hardware stripped it
	142	*/
	143	if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
f0706e82 JB	144	return TXRX_CONTINUE;
	145
	146	if (!rx->key \|\| rx->key->alg != ALG_TKIP \|\|
	147	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\| !WLAN_FC_DATA_PRESENT(fc))
	148	return TXRX_CONTINUE;
	149
	150	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	151	!rx->key->force_sw_encrypt) {
	152	if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
	153	if (skb->len < MICHAEL_MIC_LEN)
	154	return TXRX_DROP;
	155	}
	156	/* Need to verify Michael MIC sometimes in software even when
	157	* hwaccel is used. Atheros ar5212: fragmented frames and QoS
	158	* frames. */
	159	if (!rx->fragmented && !wpa_test)
	160	goto remove_mic;
	161	}
	162
	163	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
	164	\|\| data_len < MICHAEL_MIC_LEN)
	165	return TXRX_DROP;
	166
	167	data_len -= MICHAEL_MIC_LEN;
	168
	169	#if 0
	170	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
	171	#else
	172	authenticator = 1;
	173	#endif
	174	key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
	175	ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
	176	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
	177	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 \|\| wpa_test) {
	178	if (!rx->u.rx.ra_match)
	179	return TXRX_DROP;
	180
	181	printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
	182	MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
	183
	184	do {
	185	struct ieee80211_hdr *hdr;
	186	union iwreq_data wrqu;
	187	char *buf = kmalloc(128, GFP_ATOMIC);
	188	if (!buf)
	189	break;
	190
	191	/* TODO: needed parameters: count, key type, TSC */
	192	hdr = (struct ieee80211_hdr *) skb->data;
	193	sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
	194	"keyid=%d %scast addr=" MAC_FMT ")",
	195	rx->key->keyidx,
	196	hdr->addr1[0] & 0x01 ? "broad" : "uni",
	197	MAC_ARG(hdr->addr2));
	198	memset(&wrqu, 0, sizeof(wrqu));
	199	wrqu.data.length = strlen(buf);
	200	wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
	201	kfree(buf);
	202	} while (0);
	203
	204	if (!rx->local->apdev)
	205	return TXRX_DROP;
	206
	207	ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
208	ieee80211_msg_michael_mic_failure);
209
210	return TXRX_QUEUED;
211	}
212
213	remove_mic:
214	/* remove Michael MIC from payload */
215	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
216
217	return TXRX_CONTINUE;
218	}
219
220
221	static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
222	struct sk_buff *skb, int test)
223	{
224	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
225	struct ieee80211_key *key = tx->key;
226	int hdrlen, len, tailneed;
227	u16 fc;
228	u8 *pos;
229
230	fc = le16_to_cpu(hdr->frame_control);
231	hdrlen = ieee80211_get_hdrlen(fc);
232	len = skb->len - hdrlen;
233
234	tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN;
235	if ((skb_headroom(skb) < TKIP_IV_LEN \|\|
236	skb_tailroom(skb) < tailneed)) {
237	I802_DEBUG_INC(tx->local->tx_expand_skb_head);
238	if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
239	GFP_ATOMIC)))
240	return -1;
241	}
242
243	pos = skb_push(skb, TKIP_IV_LEN);
244	memmove(pos, pos + TKIP_IV_LEN, hdrlen);
245	pos += hdrlen;
246
247	/* Increase IV for the frame */
248	key->u.tkip.iv16++;
249	if (key->u.tkip.iv16 == 0)
250	key->u.tkip.iv32++;
251
252	if (!tx->key->force_sw_encrypt) {
253	u32 flags = tx->local->hw.flags;
254	hdr = (struct ieee80211_hdr *)skb->data;
255
256	/* hwaccel - with preallocated room for IV */
257	ieee80211_tkip_add_iv(pos, key,
258	(u8) (key->u.tkip.iv16 >> 8),
259	(u8) (((key->u.tkip.iv16 >> 8) \| 0x20) &
260	0x7f),
261	(u8) key->u.tkip.iv16);
262
263	if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
264	ieee80211_tkip_gen_rc4key(key, hdr->addr2,
265	tx->u.tx.control->tkip_key);
266	else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
267	if (key->u.tkip.iv16 == 0 \|\|
268	!key->u.tkip.tx_initialized) {
269	ieee80211_tkip_gen_phase1key(key, hdr->addr2,
270	(u16 *)tx->u.tx.control->tkip_key);
271	key->u.tkip.tx_initialized = 1;
272	tx->u.tx.control->flags \|=
273	IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
274	} else
275	tx->u.tx.control->flags &=
276	~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
277	}
278
279	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
280	return 0;
281	}
282
283	/* Add room for ICV */
284	skb_put(skb, TKIP_ICV_LEN);
285
286	hdr = (struct ieee80211_hdr *) skb->data;
287	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
288	key, pos, len, hdr->addr2);
289	return 0;
290	}
291
292
293	ieee80211_txrx_result
294	ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
295	{
296	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) tx->skb->data;
297	u16 fc;
298	struct ieee80211_key *key = tx->key;
299	struct sk_buff *skb = tx->skb;
300	int wpa_test = 0, test = 0;
301
302	fc = le16_to_cpu(hdr->frame_control);
303
304	if (!key \|\| key->alg != ALG_TKIP \|\| !WLAN_FC_DATA_PRESENT(fc))
305	return TXRX_CONTINUE;
306
307	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
308	tx->u.tx.control->iv_len = TKIP_IV_LEN;
309	ieee80211_tx_set_iswep(tx);
310
311	if (!tx->key->force_sw_encrypt &&
312	!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
313	!wpa_test) {
314	/* hwaccel - with no need for preallocated room for IV/ICV */
315	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
316	return TXRX_CONTINUE;
317	}
318
319	if (tkip_encrypt_skb(tx, skb, test) < 0)
320	return TXRX_DROP;
321
322	if (tx->u.tx.extra_frag) {
323	int i;
324	for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
325	if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
326	< 0)
327	return TXRX_DROP;
328	}
329	}
330
331	return TXRX_CONTINUE;
332	}
333
334
335	ieee80211_txrx_result
336	ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx)
337	{
338	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) rx->skb->data;
339	u16 fc;
340	int hdrlen, res, hwaccel = 0, wpa_test = 0;
341	struct ieee80211_key *key = rx->key;
342	struct sk_buff *skb = rx->skb;
343
344	fc = le16_to_cpu(hdr->frame_control);
345	hdrlen = ieee80211_get_hdrlen(fc);
346
347	if (!rx->key \|\| rx->key->alg != ALG_TKIP \|\|
348	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\|
349	(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
350	return TXRX_CONTINUE;
351
352	if (!rx->sta \|\| skb->len - hdrlen < 12)
353	return TXRX_DROP;
354
355	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
356	!rx->key->force_sw_encrypt) {
357	if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
358	/* Hardware takes care of all processing, including
359	* replay protection, so no need to continue here. */
360	return TXRX_CONTINUE;
361	}
362
363	/* let TKIP code verify IV, but skip decryption */
364	hwaccel = 1;
365	}
366
367	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
368	key, skb->data + hdrlen,
369	skb->len - hdrlen, rx->sta->addr,
370	hwaccel, rx->u.rx.queue);
371	if (res != TKIP_DECRYPT_OK \|\| wpa_test) {
372	printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
373	MAC_FMT " (res=%d)\n",
374	rx->dev->name, MAC_ARG(rx->sta->addr), res);
375	return TXRX_DROP;
376	}
377
378	/* Trim ICV */
379	skb_trim(skb, skb->len - TKIP_ICV_LEN);
380
381	/* Remove IV */
382	memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
383	skb_pull(skb, TKIP_IV_LEN);
384
385	return TXRX_CONTINUE;
386	}
387
388
389	static void ccmp_special_blocks(struct sk_buff skb, u8 pn, u8 b_0, u8 aad,
390	int encrypted)
391	{
392	u16 fc;
393	int a4_included, qos_included;
394	u8 qos_tid, fc_pos, data, sa, da;
395	int len_a;
396	size_t data_len;
397	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
398
399	fc_pos = (u8 *) &hdr->frame_control;
400	fc = fc_pos[0] ^ (fc_pos[1] << 8);
401	a4_included = (fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
402	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS);
403
404	ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
405	data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
406	if (qos_tid & 0x80) {
407	qos_included = 1;
408	qos_tid &= 0x0f;
409	} else
410	qos_included = 0;
411	/* First block, b_0 */
412
413	b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
414	/* Nonce: QoS Priority \| A2 \| PN */
415	b_0[1] = qos_tid;
416	memcpy(&b_0[2], hdr->addr2, 6);
417	memcpy(&b_0[8], pn, CCMP_PN_LEN);
418	/* l(m) */
419	b_0[14] = (data_len >> 8) & 0xff;
420	b_0[15] = data_len & 0xff;
421
422
423	/* AAD (extra authenticate-only data) / masked 802.11 header
424	* FC \| A1 \| A2 \| A3 \| SC \| [A4] \| [QC] */
425
426	len_a = a4_included ? 28 : 22;
427	if (qos_included)
428	len_a += 2;
429
430	aad[0] = 0; /* (len_a >> 8) & 0xff; */
431	aad[1] = len_a & 0xff;
432	/* Mask FC: zero subtype b4 b5 b6 */
433	aad[2] = fc_pos[0] & ~(BIT(4) \| BIT(5) \| BIT(6));
434	/* Retry, PwrMgt, MoreData; set Protected */
435	aad[3] = (fc_pos[1] & ~(BIT(3) \| BIT(4) \| BIT(5))) \| BIT(6);
436	memcpy(&aad[4], &hdr->addr1, 18);
437
438	/* Mask Seq#, leave Frag# */
439	aad[22] = ((u8 ) &hdr->seq_ctrl) & 0x0f;
440	aad[23] = 0;
441	if (a4_included) {
442	memcpy(&aad[24], hdr->addr4, 6);
443	aad[30] = 0;
444	aad[31] = 0;
445	} else
446	memset(&aad[24], 0, 8);
447	if (qos_included) {
448	u8 *dpos = &aad[a4_included ? 30 : 24];
449
450	/* Mask QoS Control field */
451	dpos[0] = qos_tid;
452	dpos[1] = 0;
453	}
454	}
455
456
457	static inline void ccmp_pn2hdr(u8 hdr, u8 pn, int key_id)
458	{
459	hdr[0] = pn[5];
460	hdr[1] = pn[4];
461	hdr[2] = 0;
462	hdr[3] = 0x20 \| (key_id << 6);
463	hdr[4] = pn[3];
464	hdr[5] = pn[2];
465	hdr[6] = pn[1];
466	hdr[7] = pn[0];
467	}
468
469
470	static inline int ccmp_hdr2pn(u8 pn, u8 hdr)
471	{
472	pn[0] = hdr[7];
473	pn[1] = hdr[6];
474	pn[2] = hdr[5];
475	pn[3] = hdr[4];
476	pn[4] = hdr[1];
477	pn[5] = hdr[0];
478	return (hdr[3] >> 6) & 0x03;
479	}
480
481
482	static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
483	struct sk_buff *skb, int test)
484	{
485	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
486	struct ieee80211_key *key = tx->key;
487	int hdrlen, len, tailneed;
488	u16 fc;
489	u8 pos, pn, b_0, aad, *scratch;
490	int i;
491
492	scratch = key->u.ccmp.tx_crypto_buf;
493	b_0 = scratch + 3 * AES_BLOCK_LEN;
494	aad = scratch + 4 * AES_BLOCK_LEN;
495
496	fc = le16_to_cpu(hdr->frame_control);
497	hdrlen = ieee80211_get_hdrlen(fc);
498	len = skb->len - hdrlen;
499
500	tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN;
501
502	if ((skb_headroom(skb) < CCMP_HDR_LEN \|\|
503	skb_tailroom(skb) < tailneed)) {
504	I802_DEBUG_INC(tx->local->tx_expand_skb_head);
505	if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
506	GFP_ATOMIC)))
507	return -1;
508	}
509
510	pos = skb_push(skb, CCMP_HDR_LEN);
511	memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
512	hdr = (struct ieee80211_hdr *) pos;
513	pos += hdrlen;
514
515	/* PN = PN + 1 */
516	pn = key->u.ccmp.tx_pn;
517
518	for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
519	pn[i]++;
520	if (pn[i])
521	break;
522	}
523
524	ccmp_pn2hdr(pos, pn, key->keyidx);
525
526	if (!key->force_sw_encrypt) {
527	/* hwaccel - with preallocated room for CCMP header */
528	tx->u.tx.control->key_idx = key->hw_key_idx;
529	return 0;
530	}
531
532	pos += CCMP_HDR_LEN;
533	ccmp_special_blocks(skb, pn, b_0, aad, 0);
534	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
535	pos, skb_put(skb, CCMP_MIC_LEN));
536
537	return 0;
538	}
539
540
541	ieee80211_txrx_result
542	ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
543	{
544	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) tx->skb->data;
545	struct ieee80211_key *key = tx->key;
546	u16 fc;
547	struct sk_buff *skb = tx->skb;
548	int test = 0;
549
550	fc = le16_to_cpu(hdr->frame_control);
551
552	if (!key \|\| key->alg != ALG_CCMP \|\| !WLAN_FC_DATA_PRESENT(fc))
553	return TXRX_CONTINUE;
554
555	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
556	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
557	ieee80211_tx_set_iswep(tx);
558
559	if (!tx->key->force_sw_encrypt &&
560	!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
561	/* hwaccel - with no need for preallocated room for CCMP "
562	* header or MIC fields */
563	tx->u.tx.control->key_idx = tx->key->hw_key_idx;
564	return TXRX_CONTINUE;
565	}
566
567	if (ccmp_encrypt_skb(tx, skb, test) < 0)
568	return TXRX_DROP;
569
570	if (tx->u.tx.extra_frag) {
571	int i;
572
573	for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
574	if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
575	< 0)
576	return TXRX_DROP;
577	}
578	}
579
580	return TXRX_CONTINUE;
581	}
582
583
584	ieee80211_txrx_result
585	ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx)
586	{
587	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) rx->skb->data;
588	u16 fc;
589	int hdrlen;
590	struct ieee80211_key *key = rx->key;
591	struct sk_buff *skb = rx->skb;
592	u8 pn[CCMP_PN_LEN];
593	int data_len;
594
595	fc = le16_to_cpu(hdr->frame_control);
596	hdrlen = ieee80211_get_hdrlen(fc);
597
598	if (!key \|\| key->alg != ALG_CCMP \|\|
599	!(rx->fc & IEEE80211_FCTL_PROTECTED) \|\|
600	(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
601	return TXRX_CONTINUE;
602
603	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
604	if (!rx->sta \|\| data_len < 0)
605	return TXRX_DROP;
606
607	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
608	!key->force_sw_encrypt &&
609	!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
610	return TXRX_CONTINUE;
611
612	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
613
614	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
615	#ifdef CONFIG_MAC80211_DEBUG
616	u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
617	printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
618	MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
619	"%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
620	MAC_ARG(rx->sta->addr),
621	pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
622	ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
623	#endif /* CONFIG_MAC80211_DEBUG */
624	key->u.ccmp.replays++;
625	return TXRX_DROP;
626	}
627
628	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
629	!key->force_sw_encrypt) {
630	/* hwaccel has already decrypted frame and verified MIC */
631	} else {
632	u8 scratch, b_0, *aad;
633
634	scratch = key->u.ccmp.rx_crypto_buf;
635	b_0 = scratch + 3 * AES_BLOCK_LEN;
636	aad = scratch + 4 * AES_BLOCK_LEN;
637
638	ccmp_special_blocks(skb, pn, b_0, aad, 1);
639
640	if (ieee80211_aes_ccm_decrypt(
641	key->u.ccmp.tfm, scratch, b_0, aad,
642	skb->data + hdrlen + CCMP_HDR_LEN, data_len,
643	skb->data + skb->len - CCMP_MIC_LEN,
644	skb->data + hdrlen + CCMP_HDR_LEN)) {
645	printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
646	"frame from " MAC_FMT "\n", rx->dev->name,
647	MAC_ARG(rx->sta->addr));
648	return TXRX_DROP;
649	}
650	}
651
652	memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
653
654	/* Remove CCMP header and MIC */
655	skb_trim(skb, skb->len - CCMP_MIC_LEN);
656	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
657	skb_pull(skb, CCMP_HDR_LEN);
658
659	return TXRX_CONTINUE;
660	}
661