[mirror_ubuntu-artful-kernel.git] / drivers / net / wireless / rt2x00 / rt2x00crypto.c

/*
	Copyright (C) 2004 - 2009 rt2x00 SourceForge Project
	<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, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	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->alg) {
	case ALG_WEP:
		if (key->keylen == WLAN_KEY_LEN_WEP40)
			return CIPHER_WEP64;
		else
			return CIPHER_WEP128;
	case ALG_TKIP:
		return CIPHER_TKIP;
	case ALG_CCMP:
		return CIPHER_AES;
	default:
		return CIPHER_NONE;
	}
}

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

	if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) || !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 (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) || !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->alg == ALG_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);

	/* IV/EIV data has officially be 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, bool l2pad,
			       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 (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 (!l2pad) {
		memmove(skb->data + transfer,
			skb->data + transfer + align,
			payload_len);
	}

	/*
	 * NOTE: Always count the payload as transfered,
	 * 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	/*
4e54c711	2	Copyright (C) 2004 - 2009 rt2x00 SourceForge Project
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
	16	along with this program; if not, write to the
	17	Free Software Foundation, Inc.,
	18	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	19	*/
	20
	21	/*
	22	Module: rt2x00lib
	23	Abstract: rt2x00 crypto specific routines.
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/module.h>
	28
	29	#include "rt2x00.h"
	30	#include "rt2x00lib.h"
	31
	32	enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
	33	{
	34	switch (key->alg) {
	35	case ALG_WEP:
e31a16d6	36	if (key->keylen == WLAN_KEY_LEN_WEP40)
2bb057d0 ID	37	return CIPHER_WEP64;
	38	else
	39	return CIPHER_WEP128;
	40	case ALG_TKIP:
	41	return CIPHER_TKIP;
	42	case ALG_CCMP:
	43	return CIPHER_AES;
	44	default:
	45	return CIPHER_NONE;
	46	}
	47	}
	48
9c3444d3 ID	49	void rt2x00crypto_create_tx_descriptor(struct queue_entry *entry,
	50	struct txentry_desc *txdesc)
	51	{
7b40982e	52	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
9c3444d3 ID	53	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
	54	struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
	55
18ad01c4	56	if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) \|\| !hw_key)
7b40982e ID	57	return;
7b40982e ID	58
9c3444d3 ID	59	__set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
	60
	61	txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
	62
	63	if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
	64	__set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
	65
	66	txdesc->key_idx = hw_key->hw_key_idx;
9f166171	67	txdesc->iv_offset = txdesc->header_length;
9eb4e21e	68	txdesc->iv_len = hw_key->iv_len;
9c3444d3 ID	69
	70	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
	71	__set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
	72
	73	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
	74	__set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
	75	}
	76
7b40982e ID	77	unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
7b40982e ID	78	struct sk_buff *skb)
2bb057d0	79	{
7b40982e	80	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
2bb057d0 ID	81	struct ieee80211_key_conf *key = tx_info->control.hw_key;
	82	unsigned int overhead = 0;
	83
18ad01c4	84	if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) \|\| !key)
7b40982e ID	85	return overhead;
7b40982e ID	86
2bb057d0 ID	87	/*
	88	* Extend frame length to include IV/EIV/ICV/MMIC,
	89	* note that these lengths should only be added when
	90	* mac80211 does not generate it.
	91	*/
76708dee	92	overhead += key->icv_len;
2bb057d0 ID	93
2bb057d0 ID	94	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
76708dee	95	overhead += key->iv_len;
2bb057d0 ID	96
	97	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
	98	if (key->alg == ALG_TKIP)
	99	overhead += 8;
	100	}
	101
	102	return overhead;
	103	}
	104
9eb4e21e	105	void rt2x00crypto_tx_copy_iv(struct sk_buff skb, struct txentry_desc txdesc)
dddfb478 ID	106	{
dddfb478 ID	107	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
dddfb478	108
9eb4e21e	109	if (unlikely(!txdesc->iv_len))
dddfb478 ID	110	return;
	111
	112	/* Copy IV/EIV data */
9eb4e21e	113	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
dddfb478 ID	114	}
dddfb478 ID	115
9eb4e21e	116	void rt2x00crypto_tx_remove_iv(struct sk_buff skb, struct txentry_desc txdesc)
2bb057d0 ID	117	{
2bb057d0 ID	118	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
2bb057d0	119
9eb4e21e	120	if (unlikely(!txdesc->iv_len))
2bb057d0 ID	121	return;
	122
	123	/* Copy IV/EIV data */
9eb4e21e	124	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
2bb057d0 ID	125
2bb057d0 ID	126	/* Move ieee80211 header */
9eb4e21e	127	memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
2bb057d0 ID	128
2bb057d0 ID	129	/* Pull buffer to correct size */
9eb4e21e	130	skb_pull(skb, txdesc->iv_len);
2bb057d0 ID	131
2bb057d0 ID	132	/* IV/EIV data has officially be stripped */
9f166171	133	skbdesc->flags \|= SKBDESC_IV_STRIPPED;
2bb057d0 ID	134	}
2bb057d0 ID	135
9f166171	136	void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
2bb057d0 ID	137	{
2bb057d0 ID	138	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
2bb057d0	139	const unsigned int iv_len =
1ce9cdac	140	((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);
2bb057d0	141
9f166171	142	if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
2bb057d0 ID	143	return;
	144
	145	skb_push(skb, iv_len);
	146
	147	/* Move ieee80211 header */
	148	memmove(skb->data, skb->data + iv_len, header_length);
	149
	150	/* Copy IV/EIV data */
1ce9cdac	151	memcpy(skb->data + header_length, skbdesc->iv, iv_len);
2bb057d0 ID	152
2bb057d0 ID	153	/* IV/EIV data has returned into the frame */
9f166171	154	skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
2bb057d0 ID	155	}
2bb057d0 ID	156
9f166171	157	void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, bool l2pad,
2bb057d0 ID	158	unsigned int header_length,
	159	struct rxdone_entry_desc *rxdesc)
	160	{
	161	unsigned int payload_len = rxdesc->size - header_length;
9f166171	162	unsigned int align = ALIGN_SIZE(skb, header_length);
2bb057d0 ID	163	unsigned int iv_len;
	164	unsigned int icv_len;
	165	unsigned int transfer = 0;
	166
	167	/*
	168	* WEP64/WEP128: Provides IV & ICV
	169	* TKIP: Provides IV/EIV & ICV
	170	* AES: Provies IV/EIV & ICV
	171	*/
	172	switch (rxdesc->cipher) {
	173	case CIPHER_WEP64:
	174	case CIPHER_WEP128:
	175	iv_len = 4;
	176	icv_len = 4;
	177	break;
	178	case CIPHER_TKIP:
	179	iv_len = 8;
	180	icv_len = 4;
	181	break;
	182	case CIPHER_AES:
	183	iv_len = 8;
	184	icv_len = 8;
	185	break;
	186	default:
	187	/* Unsupport type */
	188	return;
	189	}
	190
	191	/*
9f166171 ID	192	* Make room for new data. There are 2 possibilities
	193	* either the alignment is already present between
	194	* the 802.11 header and payload. In that case we
	195	* we have to move the header less then the iv_len
	196	* since we can use the already available l2pad bytes
	197	* for the iv data.
	198	* When the alignment must be added manually we must
	199	* move the header more then iv_len since we must
	200	* make room for the payload move as well.
2bb057d0	201	*/
9f166171 ID	202	if (l2pad) {
	203	skb_push(skb, iv_len - align);
	204	skb_put(skb, icv_len);
2bb057d0	205
9f166171 ID	206	/* Move ieee80211 header */
	207	memmove(skb->data + transfer,
	208	skb->data + transfer + (iv_len - align),
	209	header_length);
	210	transfer += header_length;
	211	} else {
	212	skb_push(skb, iv_len + align);
	213	if (align < icv_len)
	214	skb_put(skb, icv_len - align);
	215	else if (align > icv_len)
	216	skb_trim(skb, rxdesc->size + iv_len + icv_len);
	217
	218	/* Move ieee80211 header */
	219	memmove(skb->data + transfer,
	220	skb->data + transfer + iv_len + align,
	221	header_length);
	222	transfer += header_length;
	223	}
2bb057d0	224
1ce9cdac ID	225	/* Copy IV/EIV data */
	226	memcpy(skb->data + transfer, rxdesc->iv, iv_len);
	227	transfer += iv_len;
2bb057d0	228
9f166171 ID	229	/*
	230	* Move payload for alignment purposes. Note that
	231	* this is only needed when no l2 padding is present.
	232	*/
	233	if (!l2pad) {
2bb057d0 ID	234	memmove(skb->data + transfer,
	235	skb->data + transfer + align,
	236	payload_len);
	237	}
	238
	239	/*
	240	* NOTE: Always count the payload as transfered,
	241	* even when alignment was set to zero. This is required
	242	* for determining the correct offset for the ICV data.
	243	*/
	244	transfer += payload_len;
	245
1ce9cdac ID	246	/*
	247	* Copy ICV data
	248	* AES appends 8 bytes, we can't fill the upper
	249	* 4 bytes, but mac80211 doesn't care about what
	250	* we provide here anyway and strips it immediately.
	251	*/
	252	memcpy(skb->data + transfer, &rxdesc->icv, 4);
	253	transfer += icv_len;
2bb057d0 ID	254
	255	/* IV/EIV/ICV has been inserted into frame */
	256	rxdesc->size = transfer;
	257	rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
	258	}