1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/*
Copyright (C) 2004 - 2008 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;
}
}
unsigned int rt2x00crypto_tx_overhead(struct ieee80211_tx_info *tx_info)
{
struct ieee80211_key_conf *key = tx_info->control.hw_key;
unsigned int overhead = 0;
/*
* 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_remove_iv(struct sk_buff *skb, unsigned int iv_len)
{
struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
unsigned int header_length = ieee80211_get_hdrlen_from_skb(skb);
if (unlikely(!iv_len))
return;
/* Copy IV/EIV data */
memcpy(skbdesc->iv, skb->data + header_length, iv_len);
/* Move ieee80211 header */
memmove(skb->data + iv_len, skb->data, header_length);
/* Pull buffer to correct size */
skb_pull(skb, 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 then the ICV data.
* When alignment requirements is greater then 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;
}
|
