[deliverable/linux.git] / drivers / net / wireless / ralink / rt2x00 / rt2x00crypto.c

/*
	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

/*
	Module: rt2x00lib
	Abstract: rt2x00 crypto specific routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
{
	switch (key->cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
		return CIPHER_WEP64;
	case WLAN_CIPHER_SUITE_WEP104:
		return CIPHER_WEP128;
	case WLAN_CIPHER_SUITE_TKIP:
		return CIPHER_TKIP;
	case WLAN_CIPHER_SUITE_CCMP:
		return CIPHER_AES;
	default:
		return CIPHER_NONE;
	}
}

void rt2x00crypto_create_tx_descriptor(struct rt2x00_dev *rt2x00dev,
				       struct sk_buff *skb,
				       struct txentry_desc *txdesc)
{
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
	struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;

	if (!rt2x00_has_cap_hw_crypto(rt2x00dev) || !hw_key)
		return;

	__set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);

	txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);

	if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
		__set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);

	txdesc->key_idx = hw_key->hw_key_idx;
	txdesc->iv_offset = txdesc->header_length;
	txdesc->iv_len = hw_key->iv_len;

	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
		__set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);

	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
		__set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
}

unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
				      struct sk_buff *skb)
{
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
	struct ieee80211_key_conf *key = tx_info->control.hw_key;
	unsigned int overhead = 0;

	if (!rt2x00_has_cap_hw_crypto(rt2x00dev) || !key)
		return overhead;

	/*
	 * Extend frame length to include IV/EIV/ICV/MMIC,
	 * note that these lengths should only be added when
	 * mac80211 does not generate it.
	 */
	overhead += key->icv_len;

	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
		overhead += key->iv_len;

	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
		if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
			overhead += 8;
	}

	return overhead;
}

void rt2x00crypto_tx_copy_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	if (unlikely(!txdesc->iv_len))
		return;

	/* Copy IV/EIV data */
	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
}

void rt2x00crypto_tx_remove_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	if (unlikely(!txdesc->iv_len))
		return;

	/* Copy IV/EIV data */
	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);

	/* Move ieee80211 header */
	memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);

	/* Pull buffer to correct size */
	skb_pull(skb, txdesc->iv_len);
	txdesc->length -= txdesc->iv_len;

	/* IV/EIV data has officially been stripped */
	skbdesc->flags |= SKBDESC_IV_STRIPPED;
}

void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
	const unsigned int iv_len =
	    ((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);

	if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
		return;

	skb_push(skb, iv_len);

	/* Move ieee80211 header */
	memmove(skb->data, skb->data + iv_len, header_length);

	/* Copy IV/EIV data */
	memcpy(skb->data + header_length, skbdesc->iv, iv_len);

	/* IV/EIV data has returned into the frame */
	skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
}

void rt2x00crypto_rx_insert_iv(struct sk_buff *skb,
			       unsigned int header_length,
			       struct rxdone_entry_desc *rxdesc)
{
	unsigned int payload_len = rxdesc->size - header_length;
	unsigned int align = ALIGN_SIZE(skb, header_length);
	unsigned int iv_len;
	unsigned int icv_len;
	unsigned int transfer = 0;

	/*
	 * WEP64/WEP128: Provides IV & ICV
	 * TKIP: Provides IV/EIV & ICV
	 * AES: Provies IV/EIV & ICV
	 */
	switch (rxdesc->cipher) {
	case CIPHER_WEP64:
	case CIPHER_WEP128:
		iv_len = 4;
		icv_len = 4;
		break;
	case CIPHER_TKIP:
		iv_len = 8;
		icv_len = 4;
		break;
	case CIPHER_AES:
		iv_len = 8;
		icv_len = 8;
		break;
	default:
		/* Unsupport type */
		return;
	}

	/*
	 * Make room for new data. There are 2 possibilities
	 * either the alignment is already present between
	 * the 802.11 header and payload. In that case we
	 * we have to move the header less then the iv_len
	 * since we can use the already available l2pad bytes
	 * for the iv data.
	 * When the alignment must be added manually we must
	 * move the header more then iv_len since we must
	 * make room for the payload move as well.
	 */
	if (rxdesc->dev_flags & RXDONE_L2PAD) {
		skb_push(skb, iv_len - align);
		skb_put(skb, icv_len);

		/* Move ieee80211 header */
		memmove(skb->data + transfer,
			skb->data + transfer + (iv_len - align),
			header_length);
		transfer += header_length;
	} else {
		skb_push(skb, iv_len + align);
		if (align < icv_len)
			skb_put(skb, icv_len - align);
		else if (align > icv_len)
			skb_trim(skb, rxdesc->size + iv_len + icv_len);

		/* Move ieee80211 header */
		memmove(skb->data + transfer,
			skb->data + transfer + iv_len + align,
			header_length);
		transfer += header_length;
	}

	/* Copy IV/EIV data */
	memcpy(skb->data + transfer, rxdesc->iv, iv_len);
	transfer += iv_len;

	/*
	 * Move payload for alignment purposes. Note that
	 * this is only needed when no l2 padding is present.
	 */
	if (!(rxdesc->dev_flags & RXDONE_L2PAD)) {
		memmove(skb->data + transfer,
			skb->data + transfer + align,
			payload_len);
	}

	/*
	 * NOTE: Always count the payload as transferred,
	 * even when alignment was set to zero. This is required
	 * for determining the correct offset for the ICV data.
	 */
	transfer += payload_len;

	/*
	 * Copy ICV data
	 * AES appends 8 bytes, we can't fill the upper
	 * 4 bytes, but mac80211 doesn't care about what
	 * we provide here anyway and strips it immediately.
	 */
	memcpy(skb->data + transfer, &rxdesc->icv, 4);
	transfer += icv_len;

	/* IV/EIV/ICV has been inserted into frame */
	rxdesc->size = transfer;
	rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
}
Commit	Line	Data
2bb057d0	1	/*
9c9a0d14	2	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
2bb057d0 ID	3	<http://rt2x00.serialmonkey.com>
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
a05b8c58	16	along with this program; if not, see <http://www.gnu.org/licenses/>.
2bb057d0 ID	17	*/
	18
	19	/*
	20	Module: rt2x00lib
	21	Abstract: rt2x00 crypto specific routines.
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26
	27	#include "rt2x00.h"
	28	#include "rt2x00lib.h"
	29
	30	enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
	31	{
97359d12 JB	32	switch (key->cipher) {
	33	case WLAN_CIPHER_SUITE_WEP40:
	34	return CIPHER_WEP64;
	35	case WLAN_CIPHER_SUITE_WEP104:
	36	return CIPHER_WEP128;
	37	case WLAN_CIPHER_SUITE_TKIP:
2bb057d0	38	return CIPHER_TKIP;
97359d12	39	case WLAN_CIPHER_SUITE_CCMP:
2bb057d0 ID	40	return CIPHER_AES;
	41	default:
	42	return CIPHER_NONE;
	43	}
	44	}
	45
77b5621b GW	46	void rt2x00crypto_create_tx_descriptor(struct rt2x00_dev *rt2x00dev,
77b5621b GW	47	struct sk_buff *skb,
9c3444d3 ID	48	struct txentry_desc *txdesc)
9c3444d3 ID	49	{
77b5621b	50	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
9c3444d3 ID	51	struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
9c3444d3 ID	52
7b8a00dc	53	if (!rt2x00_has_cap_hw_crypto(rt2x00dev) \|\| !hw_key)
7b40982e ID	54	return;
7b40982e ID	55
9c3444d3 ID	56	__set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
	57
	58	txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
	59
	60	if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
	61	__set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
	62
	63	txdesc->key_idx = hw_key->hw_key_idx;
9f166171	64	txdesc->iv_offset = txdesc->header_length;
9eb4e21e	65	txdesc->iv_len = hw_key->iv_len;
9c3444d3 ID	66
	67	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
	68	__set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
	69
	70	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
	71	__set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
	72	}
	73
7b40982e ID	74	unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
7b40982e ID	75	struct sk_buff *skb)
2bb057d0	76	{
7b40982e	77	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
2bb057d0 ID	78	struct ieee80211_key_conf *key = tx_info->control.hw_key;
	79	unsigned int overhead = 0;
	80
7b8a00dc	81	if (!rt2x00_has_cap_hw_crypto(rt2x00dev) \|\| !key)
7b40982e ID	82	return overhead;
7b40982e ID	83
2bb057d0 ID	84	/*
	85	* Extend frame length to include IV/EIV/ICV/MMIC,
	86	* note that these lengths should only be added when
	87	* mac80211 does not generate it.
	88	*/
76708dee	89	overhead += key->icv_len;
2bb057d0 ID	90
2bb057d0 ID	91	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
76708dee	92	overhead += key->iv_len;
2bb057d0 ID	93
2bb057d0 ID	94	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
97359d12	95	if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
2bb057d0 ID	96	overhead += 8;
	97	}
	98
	99	return overhead;
	100	}
	101
9eb4e21e	102	void rt2x00crypto_tx_copy_iv(struct sk_buff skb, struct txentry_desc txdesc)
dddfb478 ID	103	{
dddfb478 ID	104	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
dddfb478	105
9eb4e21e	106	if (unlikely(!txdesc->iv_len))
dddfb478 ID	107	return;
	108
	109	/* Copy IV/EIV data */
9eb4e21e	110	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
dddfb478 ID	111	}
dddfb478 ID	112
9eb4e21e	113	void rt2x00crypto_tx_remove_iv(struct sk_buff skb, struct txentry_desc txdesc)
2bb057d0 ID	114	{
2bb057d0 ID	115	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
2bb057d0	116
9eb4e21e	117	if (unlikely(!txdesc->iv_len))
2bb057d0 ID	118	return;
	119
	120	/* Copy IV/EIV data */
9eb4e21e	121	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
2bb057d0 ID	122
2bb057d0 ID	123	/* Move ieee80211 header */
9eb4e21e	124	memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
2bb057d0 ID	125
2bb057d0 ID	126	/* Pull buffer to correct size */
9eb4e21e	127	skb_pull(skb, txdesc->iv_len);
d43e49ec	128	txdesc->length -= txdesc->iv_len;
2bb057d0	129
49513481	130	/* IV/EIV data has officially been stripped */
9f166171	131	skbdesc->flags \|= SKBDESC_IV_STRIPPED;
2bb057d0 ID	132	}
2bb057d0 ID	133
9f166171	134	void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
2bb057d0 ID	135	{
2bb057d0 ID	136	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
2bb057d0	137	const unsigned int iv_len =
1ce9cdac	138	((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);
2bb057d0	139
9f166171	140	if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
2bb057d0 ID	141	return;
	142
	143	skb_push(skb, iv_len);
	144
	145	/* Move ieee80211 header */
	146	memmove(skb->data, skb->data + iv_len, header_length);
	147
	148	/* Copy IV/EIV data */
1ce9cdac	149	memcpy(skb->data + header_length, skbdesc->iv, iv_len);
2bb057d0 ID	150
2bb057d0 ID	151	/* IV/EIV data has returned into the frame */
9f166171	152	skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
2bb057d0 ID	153	}
2bb057d0 ID	154
daee6c09	155	void rt2x00crypto_rx_insert_iv(struct sk_buff *skb,
2bb057d0 ID	156	unsigned int header_length,
	157	struct rxdone_entry_desc *rxdesc)
	158	{
	159	unsigned int payload_len = rxdesc->size - header_length;
9f166171	160	unsigned int align = ALIGN_SIZE(skb, header_length);
2bb057d0 ID	161	unsigned int iv_len;
	162	unsigned int icv_len;
	163	unsigned int transfer = 0;
	164
	165	/*
	166	* WEP64/WEP128: Provides IV & ICV
	167	* TKIP: Provides IV/EIV & ICV
	168	* AES: Provies IV/EIV & ICV
	169	*/
	170	switch (rxdesc->cipher) {
	171	case CIPHER_WEP64:
	172	case CIPHER_WEP128:
	173	iv_len = 4;
	174	icv_len = 4;
	175	break;
	176	case CIPHER_TKIP:
	177	iv_len = 8;
	178	icv_len = 4;
	179	break;
	180	case CIPHER_AES:
	181	iv_len = 8;
	182	icv_len = 8;
	183	break;
	184	default:
	185	/* Unsupport type */
	186	return;
	187	}
	188
	189	/*
9f166171 ID	190	* Make room for new data. There are 2 possibilities
	191	* either the alignment is already present between
	192	* the 802.11 header and payload. In that case we
	193	* we have to move the header less then the iv_len
	194	* since we can use the already available l2pad bytes
	195	* for the iv data.
	196	* When the alignment must be added manually we must
	197	* move the header more then iv_len since we must
	198	* make room for the payload move as well.
2bb057d0	199	*/
daee6c09	200	if (rxdesc->dev_flags & RXDONE_L2PAD) {
9f166171 ID	201	skb_push(skb, iv_len - align);
9f166171 ID	202	skb_put(skb, icv_len);
2bb057d0	203
9f166171 ID	204	/* Move ieee80211 header */
	205	memmove(skb->data + transfer,
	206	skb->data + transfer + (iv_len - align),
	207	header_length);
	208	transfer += header_length;
	209	} else {
	210	skb_push(skb, iv_len + align);
	211	if (align < icv_len)
	212	skb_put(skb, icv_len - align);
	213	else if (align > icv_len)
	214	skb_trim(skb, rxdesc->size + iv_len + icv_len);
	215
	216	/* Move ieee80211 header */
	217	memmove(skb->data + transfer,
	218	skb->data + transfer + iv_len + align,
	219	header_length);
	220	transfer += header_length;
	221	}
2bb057d0	222
1ce9cdac ID	223	/* Copy IV/EIV data */
	224	memcpy(skb->data + transfer, rxdesc->iv, iv_len);
	225	transfer += iv_len;
2bb057d0	226
9f166171 ID	227	/*
	228	* Move payload for alignment purposes. Note that
	229	* this is only needed when no l2 padding is present.
	230	*/
daee6c09	231	if (!(rxdesc->dev_flags & RXDONE_L2PAD)) {
2bb057d0 ID	232	memmove(skb->data + transfer,
	233	skb->data + transfer + align,
	234	payload_len);
	235	}
	236
	237	/*
25985edc	238	* NOTE: Always count the payload as transferred,
2bb057d0 ID	239	* even when alignment was set to zero. This is required
	240	* for determining the correct offset for the ICV data.
	241	*/
	242	transfer += payload_len;
	243
1ce9cdac ID	244	/*
	245	* Copy ICV data
	246	* AES appends 8 bytes, we can't fill the upper
	247	* 4 bytes, but mac80211 doesn't care about what
	248	* we provide here anyway and strips it immediately.
	249	*/
	250	memcpy(skb->data + transfer, &rxdesc->icv, 4);
	251	transfer += icv_len;
2bb057d0 ID	252
	253	/* IV/EIV/ICV has been inserted into frame */
	254	rxdesc->size = transfer;
	255	rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
	256	}