[deliverable/linux.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 == 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 || entry->skb->do_not_encrypt)
		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 = ieee80211_get_hdrlen_from_skb(entry->skb);
	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 || skb->do_not_encrypt)
		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 |= FRAME_DESC_IV_STRIPPED;
}

void rt2x00crypto_tx_insert_iv(struct sk_buff *skb)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
	unsigned int header_length = ieee80211_get_hdrlen_from_skb(skb);
	const unsigned int iv_len =
	    ((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);

	if (!(skbdesc->flags & FRAME_DESC_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 &= ~FRAME_DESC_IV_STRIPPED;
}

void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, unsigned int align,
			       unsigned int header_length,
			       struct rxdone_entry_desc *rxdesc)
{
	unsigned int payload_len = rxdesc->size - 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, note that we increase both
	 * headsize and tailsize when required. The tailsize is
	 * only needed when ICV data needs to be inserted and
	 * the padding is smaller than the ICV data.
	 * When alignment requirements is greater than the
	 * ICV data we must trim the skb to the correct size
	 * because we need to remove the extra bytes.
	 */
	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 */
	if (align) {
		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:
	36	if (key->keylen == LEN_WEP40)
	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
7b40982e ID	56	if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) \|\|
	57	!hw_key \|\| entry->skb->do_not_encrypt)
	58	return;
	59
9c3444d3 ID	60	__set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
	61
	62	txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
	63
	64	if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
	65	__set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
	66
	67	txdesc->key_idx = hw_key->hw_key_idx;
	68	txdesc->iv_offset = ieee80211_get_hdrlen_from_skb(entry->skb);
9eb4e21e	69	txdesc->iv_len = hw_key->iv_len;
9c3444d3 ID	70
	71	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
	72	__set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
	73
	74	if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
	75	__set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
	76	}
	77
7b40982e ID	78	unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
7b40982e ID	79	struct sk_buff *skb)
2bb057d0	80	{
7b40982e	81	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
2bb057d0 ID	82	struct ieee80211_key_conf *key = tx_info->control.hw_key;
	83	unsigned int overhead = 0;
	84
7b40982e ID	85	if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) \|\|
	86	!key \|\| skb->do_not_encrypt)
	87	return overhead;
	88
2bb057d0 ID	89	/*
	90	* Extend frame length to include IV/EIV/ICV/MMIC,
	91	* note that these lengths should only be added when
	92	* mac80211 does not generate it.
	93	*/
76708dee	94	overhead += key->icv_len;
2bb057d0 ID	95
2bb057d0 ID	96	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
76708dee	97	overhead += key->iv_len;
2bb057d0 ID	98
	99	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
	100	if (key->alg == ALG_TKIP)
	101	overhead += 8;
	102	}
	103
	104	return overhead;
	105	}
	106
9eb4e21e	107	void rt2x00crypto_tx_copy_iv(struct sk_buff skb, struct txentry_desc txdesc)
dddfb478 ID	108	{
dddfb478 ID	109	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
dddfb478	110
9eb4e21e	111	if (unlikely(!txdesc->iv_len))
dddfb478 ID	112	return;
	113
	114	/* Copy IV/EIV data */
9eb4e21e	115	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
dddfb478 ID	116	}
dddfb478 ID	117
9eb4e21e	118	void rt2x00crypto_tx_remove_iv(struct sk_buff skb, struct txentry_desc txdesc)
2bb057d0 ID	119	{
2bb057d0 ID	120	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
2bb057d0	121
9eb4e21e	122	if (unlikely(!txdesc->iv_len))
2bb057d0 ID	123	return;
	124
	125	/* Copy IV/EIV data */
9eb4e21e	126	memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
2bb057d0 ID	127
2bb057d0 ID	128	/* Move ieee80211 header */
9eb4e21e	129	memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
2bb057d0 ID	130
2bb057d0 ID	131	/* Pull buffer to correct size */
9eb4e21e	132	skb_pull(skb, txdesc->iv_len);
2bb057d0 ID	133
	134	/* IV/EIV data has officially be stripped */
	135	skbdesc->flags \|= FRAME_DESC_IV_STRIPPED;
	136	}
	137
	138	void rt2x00crypto_tx_insert_iv(struct sk_buff *skb)
	139	{
	140	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
	141	unsigned int header_length = ieee80211_get_hdrlen_from_skb(skb);
	142	const unsigned int iv_len =
1ce9cdac	143	((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);
2bb057d0 ID	144
	145	if (!(skbdesc->flags & FRAME_DESC_IV_STRIPPED))
	146	return;
	147
	148	skb_push(skb, iv_len);
	149
	150	/* Move ieee80211 header */
	151	memmove(skb->data, skb->data + iv_len, header_length);
	152
	153	/* Copy IV/EIV data */
1ce9cdac	154	memcpy(skb->data + header_length, skbdesc->iv, iv_len);
2bb057d0 ID	155
	156	/* IV/EIV data has returned into the frame */
	157	skbdesc->flags &= ~FRAME_DESC_IV_STRIPPED;
	158	}
	159
	160	void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, unsigned int align,
	161	unsigned int header_length,
	162	struct rxdone_entry_desc *rxdesc)
	163	{
	164	unsigned int payload_len = rxdesc->size - header_length;
	165	unsigned int iv_len;
	166	unsigned int icv_len;
	167	unsigned int transfer = 0;
	168
	169	/*
	170	* WEP64/WEP128: Provides IV & ICV
	171	* TKIP: Provides IV/EIV & ICV
	172	* AES: Provies IV/EIV & ICV
	173	*/
	174	switch (rxdesc->cipher) {
	175	case CIPHER_WEP64:
	176	case CIPHER_WEP128:
	177	iv_len = 4;
	178	icv_len = 4;
	179	break;
	180	case CIPHER_TKIP:
	181	iv_len = 8;
	182	icv_len = 4;
	183	break;
	184	case CIPHER_AES:
	185	iv_len = 8;
	186	icv_len = 8;
	187	break;
	188	default:
	189	/* Unsupport type */
	190	return;
	191	}
	192
	193	/*
	194	* Make room for new data, note that we increase both
	195	* headsize and tailsize when required. The tailsize is
	196	* only needed when ICV data needs to be inserted and
025dfdaf FS	197	* the padding is smaller than the ICV data.
025dfdaf FS	198	* When alignment requirements is greater than the
2bb057d0 ID	199	* ICV data we must trim the skb to the correct size
	200	* because we need to remove the extra bytes.
	201	*/
	202	skb_push(skb, iv_len + align);
	203	if (align < icv_len)
	204	skb_put(skb, icv_len - align);
	205	else if (align > icv_len)
	206	skb_trim(skb, rxdesc->size + iv_len + icv_len);
	207
	208	/* Move ieee80211 header */
	209	memmove(skb->data + transfer,
	210	skb->data + transfer + iv_len + align,
	211	header_length);
	212	transfer += header_length;
	213
1ce9cdac ID	214	/* Copy IV/EIV data */
	215	memcpy(skb->data + transfer, rxdesc->iv, iv_len);
	216	transfer += iv_len;
2bb057d0 ID	217
	218	/* Move payload */
	219	if (align) {
	220	memmove(skb->data + transfer,
	221	skb->data + transfer + align,
	222	payload_len);
	223	}
	224
	225	/*
	226	* NOTE: Always count the payload as transfered,
	227	* even when alignment was set to zero. This is required
	228	* for determining the correct offset for the ICV data.
	229	*/
	230	transfer += payload_len;
	231
1ce9cdac ID	232	/*
	233	* Copy ICV data
	234	* AES appends 8 bytes, we can't fill the upper
	235	* 4 bytes, but mac80211 doesn't care about what
	236	* we provide here anyway and strips it immediately.
	237	*/
	238	memcpy(skb->data + transfer, &rxdesc->icv, 4);
	239	transfer += icv_len;
2bb057d0 ID	240
	241	/* IV/EIV/ICV has been inserted into frame */
	242	rxdesc->size = transfer;
	243	rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
	244	}