2 Copyright (C) 2004 - 2008 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
== LEN_WEP40
)
49 void rt2x00crypto_create_tx_descriptor(struct queue_entry
*entry
,
50 struct txentry_desc
*txdesc
)
52 struct ieee80211_tx_info
*tx_info
= IEEE80211_SKB_CB(entry
->skb
);
53 struct ieee80211_key_conf
*hw_key
= tx_info
->control
.hw_key
;
55 __set_bit(ENTRY_TXD_ENCRYPT
, &txdesc
->flags
);
57 txdesc
->cipher
= rt2x00crypto_key_to_cipher(hw_key
);
59 if (hw_key
->flags
& IEEE80211_KEY_FLAG_PAIRWISE
)
60 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE
, &txdesc
->flags
);
62 txdesc
->key_idx
= hw_key
->hw_key_idx
;
63 txdesc
->iv_offset
= ieee80211_get_hdrlen_from_skb(entry
->skb
);
65 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
66 __set_bit(ENTRY_TXD_ENCRYPT_IV
, &txdesc
->flags
);
68 if (!(hw_key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
))
69 __set_bit(ENTRY_TXD_ENCRYPT_MMIC
, &txdesc
->flags
);
72 unsigned int rt2x00crypto_tx_overhead(struct ieee80211_tx_info
*tx_info
)
74 struct ieee80211_key_conf
*key
= tx_info
->control
.hw_key
;
75 unsigned int overhead
= 0;
78 * Extend frame length to include IV/EIV/ICV/MMIC,
79 * note that these lengths should only be added when
80 * mac80211 does not generate it.
82 overhead
+= key
->icv_len
;
84 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
))
85 overhead
+= key
->iv_len
;
87 if (!(key
->flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
)) {
88 if (key
->alg
== ALG_TKIP
)
95 void rt2x00crypto_tx_copy_iv(struct sk_buff
*skb
, unsigned int iv_len
)
97 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
98 unsigned int header_length
= ieee80211_get_hdrlen_from_skb(skb
);
100 if (unlikely(!iv_len
))
103 /* Copy IV/EIV data */
104 memcpy(skbdesc
->iv
, skb
->data
+ header_length
, iv_len
);
107 void rt2x00crypto_tx_remove_iv(struct sk_buff
*skb
, unsigned int iv_len
)
109 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
110 unsigned int header_length
= ieee80211_get_hdrlen_from_skb(skb
);
112 if (unlikely(!iv_len
))
115 /* Copy IV/EIV data */
116 memcpy(skbdesc
->iv
, skb
->data
+ header_length
, iv_len
);
118 /* Move ieee80211 header */
119 memmove(skb
->data
+ iv_len
, skb
->data
, header_length
);
121 /* Pull buffer to correct size */
122 skb_pull(skb
, iv_len
);
124 /* IV/EIV data has officially be stripped */
125 skbdesc
->flags
|= FRAME_DESC_IV_STRIPPED
;
128 void rt2x00crypto_tx_insert_iv(struct sk_buff
*skb
)
130 struct skb_frame_desc
*skbdesc
= get_skb_frame_desc(skb
);
131 unsigned int header_length
= ieee80211_get_hdrlen_from_skb(skb
);
132 const unsigned int iv_len
=
133 ((!!(skbdesc
->iv
[0])) * 4) + ((!!(skbdesc
->iv
[1])) * 4);
135 if (!(skbdesc
->flags
& FRAME_DESC_IV_STRIPPED
))
138 skb_push(skb
, iv_len
);
140 /* Move ieee80211 header */
141 memmove(skb
->data
, skb
->data
+ iv_len
, header_length
);
143 /* Copy IV/EIV data */
144 memcpy(skb
->data
+ header_length
, skbdesc
->iv
, iv_len
);
146 /* IV/EIV data has returned into the frame */
147 skbdesc
->flags
&= ~FRAME_DESC_IV_STRIPPED
;
150 void rt2x00crypto_rx_insert_iv(struct sk_buff
*skb
, unsigned int align
,
151 unsigned int header_length
,
152 struct rxdone_entry_desc
*rxdesc
)
154 unsigned int payload_len
= rxdesc
->size
- header_length
;
156 unsigned int icv_len
;
157 unsigned int transfer
= 0;
160 * WEP64/WEP128: Provides IV & ICV
161 * TKIP: Provides IV/EIV & ICV
162 * AES: Provies IV/EIV & ICV
164 switch (rxdesc
->cipher
) {
184 * Make room for new data, note that we increase both
185 * headsize and tailsize when required. The tailsize is
186 * only needed when ICV data needs to be inserted and
187 * the padding is smaller than the ICV data.
188 * When alignment requirements is greater than the
189 * ICV data we must trim the skb to the correct size
190 * because we need to remove the extra bytes.
192 skb_push(skb
, iv_len
+ align
);
194 skb_put(skb
, icv_len
- align
);
195 else if (align
> icv_len
)
196 skb_trim(skb
, rxdesc
->size
+ iv_len
+ icv_len
);
198 /* Move ieee80211 header */
199 memmove(skb
->data
+ transfer
,
200 skb
->data
+ transfer
+ iv_len
+ align
,
202 transfer
+= header_length
;
204 /* Copy IV/EIV data */
205 memcpy(skb
->data
+ transfer
, rxdesc
->iv
, iv_len
);
210 memmove(skb
->data
+ transfer
,
211 skb
->data
+ transfer
+ align
,
216 * NOTE: Always count the payload as transfered,
217 * even when alignment was set to zero. This is required
218 * for determining the correct offset for the ICV data.
220 transfer
+= payload_len
;
224 * AES appends 8 bytes, we can't fill the upper
225 * 4 bytes, but mac80211 doesn't care about what
226 * we provide here anyway and strips it immediately.
228 memcpy(skb
->data
+ transfer
, &rxdesc
->icv
, 4);
231 /* IV/EIV/ICV has been inserted into frame */
232 rxdesc
->size
= transfer
;
233 rxdesc
->flags
&= ~RX_FLAG_IV_STRIPPED
;