2 Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
3 <http://rt2x00.serialmonkey.com>
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.
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.
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.
23 Abstract: rt2x00 crypto specific routines.
26 #include <linux/kernel.h>
27 #include <linux/module.h>
30 #include "rt2x00lib.h"
32 enum cipher
rt2x00crypto_key_to_cipher(struct ieee80211_key_conf
*key
)
34 switch (key
->cipher
) {
35 case WLAN_CIPHER_SUITE_WEP40
:
37 case WLAN_CIPHER_SUITE_WEP104
:
39 case WLAN_CIPHER_SUITE_TKIP
:
41 case WLAN_CIPHER_SUITE_CCMP
:
48 void rt2x00crypto_create_tx_descriptor(struct rt2x00_dev
*rt2x00dev
,
50 struct txentry_desc
*txdesc
)
52 struct ieee80211_tx_info
*tx_info
= IEEE80211_SKB_CB(skb
);
53 struct ieee80211_key_conf
*hw_key
= tx_info
->control
.hw_key
;
55 if (!test_bit(CAPABILITY_HW_CRYPTO
, &rt2x00dev
->cap_flags
) || !hw_key
)
58 __set_bit(ENTRY_TXD_ENCRYPT
, &txdesc
->flags
);
60 txdesc
->cipher
= rt2x00crypto_key_to_cipher(hw_key
);
62 if (hw_key
->flags
& IEEE80211_KEY_FLAG_PAIRWISE
)
63 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE
, &txdesc
->flags
);
65 txdesc
->key_idx
= hw_key
->hw_key_idx
;
66 txdesc
->iv_offset
= txdesc
->header_length
;
67 txdesc
->iv_len
= hw_key
->iv_len
;
69 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
70 __set_bit(ENTRY_TXD_ENCRYPT_IV
, &txdesc
->flags
);
72 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
))
73 __set_bit(ENTRY_TXD_ENCRYPT_MMIC
, &txdesc
->flags
);
76 unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev
*rt2x00dev
,
79 struct ieee80211_tx_info
*tx_info
= IEEE80211_SKB_CB(skb
);
80 struct ieee80211_key_conf
*key
= tx_info
->control
.hw_key
;
81 unsigned int overhead
= 0;
83 if (!test_bit(CAPABILITY_HW_CRYPTO
, &rt2x00dev
->cap_flags
) || !key
)
87 * Extend frame length to include IV/EIV/ICV/MMIC,
88 * note that these lengths should only be added when
89 * mac80211 does not generate it.
91 overhead
+= key
->icv_len
;
93 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
94 overhead
+= key
->iv_len
;
96 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
)) {
97 if (key
->cipher
== WLAN_CIPHER_SUITE_TKIP
)
104 void rt2x00crypto_tx_copy_iv(struct sk_buff
*skb
, struct txentry_desc
*txdesc
)
106 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
108 if (unlikely(!txdesc
->iv_len
))
111 /* Copy IV/EIV data */
112 memcpy(skbdesc
->iv
, skb
->data
+ txdesc
->iv_offset
, txdesc
->iv_len
);
115 void rt2x00crypto_tx_remove_iv(struct sk_buff
*skb
, struct txentry_desc
*txdesc
)
117 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
119 if (unlikely(!txdesc
->iv_len
))
122 /* Copy IV/EIV data */
123 memcpy(skbdesc
->iv
, skb
->data
+ txdesc
->iv_offset
, txdesc
->iv_len
);
125 /* Move ieee80211 header */
126 memmove(skb
->data
+ txdesc
->iv_len
, skb
->data
, txdesc
->iv_offset
);
128 /* Pull buffer to correct size */
129 skb_pull(skb
, txdesc
->iv_len
);
130 txdesc
->length
-= txdesc
->iv_len
;
132 /* IV/EIV data has officially been stripped */
133 skbdesc
->flags
|= SKBDESC_IV_STRIPPED
;
136 void rt2x00crypto_tx_insert_iv(struct sk_buff
*skb
, unsigned int header_length
)
138 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
139 const unsigned int iv_len
=
140 ((!!(skbdesc
->iv
[0])) * 4) + ((!!(skbdesc
->iv
[1])) * 4);
142 if (!(skbdesc
->flags
& SKBDESC_IV_STRIPPED
))
145 skb_push(skb
, iv_len
);
147 /* Move ieee80211 header */
148 memmove(skb
->data
, skb
->data
+ iv_len
, header_length
);
150 /* Copy IV/EIV data */
151 memcpy(skb
->data
+ header_length
, skbdesc
->iv
, iv_len
);
153 /* IV/EIV data has returned into the frame */
154 skbdesc
->flags
&= ~SKBDESC_IV_STRIPPED
;
157 void rt2x00crypto_rx_insert_iv(struct sk_buff
*skb
,
158 unsigned int header_length
,
159 struct rxdone_entry_desc
*rxdesc
)
161 unsigned int payload_len
= rxdesc
->size
- header_length
;
162 unsigned int align
= ALIGN_SIZE(skb
, header_length
);
164 unsigned int icv_len
;
165 unsigned int transfer
= 0;
168 * WEP64/WEP128: Provides IV & ICV
169 * TKIP: Provides IV/EIV & ICV
170 * AES: Provies IV/EIV & ICV
172 switch (rxdesc
->cipher
) {
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
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.
202 if (rxdesc
->dev_flags
& RXDONE_L2PAD
) {
203 skb_push(skb
, iv_len
- align
);
204 skb_put(skb
, icv_len
);
206 /* Move ieee80211 header */
207 memmove(skb
->data
+ transfer
,
208 skb
->data
+ transfer
+ (iv_len
- align
),
210 transfer
+= header_length
;
212 skb_push(skb
, iv_len
+ align
);
214 skb_put(skb
, icv_len
- align
);
215 else if (align
> icv_len
)
216 skb_trim(skb
, rxdesc
->size
+ iv_len
+ icv_len
);
218 /* Move ieee80211 header */
219 memmove(skb
->data
+ transfer
,
220 skb
->data
+ transfer
+ iv_len
+ align
,
222 transfer
+= header_length
;
225 /* Copy IV/EIV data */
226 memcpy(skb
->data
+ transfer
, rxdesc
->iv
, iv_len
);
230 * Move payload for alignment purposes. Note that
231 * this is only needed when no l2 padding is present.
233 if (!(rxdesc
->dev_flags
& RXDONE_L2PAD
)) {
234 memmove(skb
->data
+ transfer
,
235 skb
->data
+ transfer
+ align
,
240 * NOTE: Always count the payload as transferred,
241 * even when alignment was set to zero. This is required
242 * for determining the correct offset for the ICV data.
244 transfer
+= payload_len
;
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.
252 memcpy(skb
->data
+ transfer
, &rxdesc
->icv
, 4);
255 /* IV/EIV/ICV has been inserted into frame */
256 rxdesc
->size
= transfer
;
257 rxdesc
->flags
&= ~RX_FLAG_IV_STRIPPED
;