2 Copyright (C) 2004 - 2009 rt2x00 SourceForge Project
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
)
36 if (key
->keylen
== WLAN_KEY_LEN_WEP40
)
49 void rt2x00crypto_create_tx_descriptor(struct queue_entry
*entry
,
50 struct txentry_desc
*txdesc
)
52 struct rt2x00_dev
*rt2x00dev
= entry
->queue
->rt2x00dev
;
53 struct ieee80211_tx_info
*tx_info
= IEEE80211_SKB_CB(entry
->skb
);
54 struct ieee80211_key_conf
*hw_key
= tx_info
->control
.hw_key
;
56 if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO
, &rt2x00dev
->flags
) ||
57 !hw_key
|| entry
->skb
->do_not_encrypt
)
60 __set_bit(ENTRY_TXD_ENCRYPT
, &txdesc
->flags
);
62 txdesc
->cipher
= rt2x00crypto_key_to_cipher(hw_key
);
64 if (hw_key
->flags
& IEEE80211_KEY_FLAG_PAIRWISE
)
65 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE
, &txdesc
->flags
);
67 txdesc
->key_idx
= hw_key
->hw_key_idx
;
68 txdesc
->iv_offset
= txdesc
->header_length
;
69 txdesc
->iv_len
= hw_key
->iv_len
;
71 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
72 __set_bit(ENTRY_TXD_ENCRYPT_IV
, &txdesc
->flags
);
74 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
))
75 __set_bit(ENTRY_TXD_ENCRYPT_MMIC
, &txdesc
->flags
);
78 unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev
*rt2x00dev
,
81 struct ieee80211_tx_info
*tx_info
= IEEE80211_SKB_CB(skb
);
82 struct ieee80211_key_conf
*key
= tx_info
->control
.hw_key
;
83 unsigned int overhead
= 0;
85 if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO
, &rt2x00dev
->flags
) ||
86 !key
|| skb
->do_not_encrypt
)
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.
94 overhead
+= key
->icv_len
;
96 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
97 overhead
+= key
->iv_len
;
99 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
)) {
100 if (key
->alg
== ALG_TKIP
)
107 void rt2x00crypto_tx_copy_iv(struct sk_buff
*skb
, struct txentry_desc
*txdesc
)
109 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
111 if (unlikely(!txdesc
->iv_len
))
114 /* Copy IV/EIV data */
115 memcpy(skbdesc
->iv
, skb
->data
+ txdesc
->iv_offset
, txdesc
->iv_len
);
118 void rt2x00crypto_tx_remove_iv(struct sk_buff
*skb
, struct txentry_desc
*txdesc
)
120 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
122 if (unlikely(!txdesc
->iv_len
))
125 /* Copy IV/EIV data */
126 memcpy(skbdesc
->iv
, skb
->data
+ txdesc
->iv_offset
, txdesc
->iv_len
);
128 /* Move ieee80211 header */
129 memmove(skb
->data
+ txdesc
->iv_len
, skb
->data
, txdesc
->iv_offset
);
131 /* Pull buffer to correct size */
132 skb_pull(skb
, txdesc
->iv_len
);
134 /* IV/EIV data has officially be stripped */
135 skbdesc
->flags
|= SKBDESC_IV_STRIPPED
;
138 void rt2x00crypto_tx_insert_iv(struct sk_buff
*skb
, unsigned int header_length
)
140 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
141 const unsigned int iv_len
=
142 ((!!(skbdesc
->iv
[0])) * 4) + ((!!(skbdesc
->iv
[1])) * 4);
144 if (!(skbdesc
->flags
& SKBDESC_IV_STRIPPED
))
147 skb_push(skb
, iv_len
);
149 /* Move ieee80211 header */
150 memmove(skb
->data
, skb
->data
+ iv_len
, header_length
);
152 /* Copy IV/EIV data */
153 memcpy(skb
->data
+ header_length
, skbdesc
->iv
, iv_len
);
155 /* IV/EIV data has returned into the frame */
156 skbdesc
->flags
&= ~SKBDESC_IV_STRIPPED
;
159 void rt2x00crypto_rx_insert_iv(struct sk_buff
*skb
, bool l2pad
,
160 unsigned int header_length
,
161 struct rxdone_entry_desc
*rxdesc
)
163 unsigned int payload_len
= rxdesc
->size
- header_length
;
164 unsigned int align
= ALIGN_SIZE(skb
, header_length
);
166 unsigned int icv_len
;
167 unsigned int transfer
= 0;
170 * WEP64/WEP128: Provides IV & ICV
171 * TKIP: Provides IV/EIV & ICV
172 * AES: Provies IV/EIV & ICV
174 switch (rxdesc
->cipher
) {
194 * Make room for new data. There are 2 possibilities
195 * either the alignment is already present between
196 * the 802.11 header and payload. In that case we
197 * we have to move the header less then the iv_len
198 * since we can use the already available l2pad bytes
200 * When the alignment must be added manually we must
201 * move the header more then iv_len since we must
202 * make room for the payload move as well.
205 skb_push(skb
, iv_len
- align
);
206 skb_put(skb
, icv_len
);
208 /* Move ieee80211 header */
209 memmove(skb
->data
+ transfer
,
210 skb
->data
+ transfer
+ (iv_len
- align
),
212 transfer
+= header_length
;
214 skb_push(skb
, iv_len
+ align
);
216 skb_put(skb
, icv_len
- align
);
217 else if (align
> icv_len
)
218 skb_trim(skb
, rxdesc
->size
+ iv_len
+ icv_len
);
220 /* Move ieee80211 header */
221 memmove(skb
->data
+ transfer
,
222 skb
->data
+ transfer
+ iv_len
+ align
,
224 transfer
+= header_length
;
227 /* Copy IV/EIV data */
228 memcpy(skb
->data
+ transfer
, rxdesc
->iv
, iv_len
);
232 * Move payload for alignment purposes. Note that
233 * this is only needed when no l2 padding is present.
236 memmove(skb
->data
+ transfer
,
237 skb
->data
+ transfer
+ align
,
242 * NOTE: Always count the payload as transfered,
243 * even when alignment was set to zero. This is required
244 * for determining the correct offset for the ICV data.
246 transfer
+= payload_len
;
250 * AES appends 8 bytes, we can't fill the upper
251 * 4 bytes, but mac80211 doesn't care about what
252 * we provide here anyway and strips it immediately.
254 memcpy(skb
->data
+ transfer
, &rxdesc
->icv
, 4);
257 /* IV/EIV/ICV has been inserted into frame */
258 rxdesc
->size
= transfer
;
259 rxdesc
->flags
&= ~RX_FLAG_IV_STRIPPED
;