Loading...
1/*
2 Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
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
32enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
33{
34 switch (key->cipher) {
35 case WLAN_CIPHER_SUITE_WEP40:
36 return CIPHER_WEP64;
37 case WLAN_CIPHER_SUITE_WEP104:
38 return CIPHER_WEP128;
39 case WLAN_CIPHER_SUITE_TKIP:
40 return CIPHER_TKIP;
41 case WLAN_CIPHER_SUITE_CCMP:
42 return CIPHER_AES;
43 default:
44 return CIPHER_NONE;
45 }
46}
47
48void rt2x00crypto_create_tx_descriptor(struct rt2x00_dev *rt2x00dev,
49 struct sk_buff *skb,
50 struct txentry_desc *txdesc)
51{
52 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
53 struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
54
55 if (!test_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags) || !hw_key)
56 return;
57
58 __set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
59
60 txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
61
62 if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
63 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
64
65 txdesc->key_idx = hw_key->hw_key_idx;
66 txdesc->iv_offset = txdesc->header_length;
67 txdesc->iv_len = hw_key->iv_len;
68
69 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
70 __set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
71
72 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
73 __set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
74}
75
76unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
77 struct sk_buff *skb)
78{
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;
82
83 if (!test_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags) || !key)
84 return overhead;
85
86 /*
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.
90 */
91 overhead += key->icv_len;
92
93 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
94 overhead += key->iv_len;
95
96 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
97 if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
98 overhead += 8;
99 }
100
101 return overhead;
102}
103
104void rt2x00crypto_tx_copy_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
105{
106 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
107
108 if (unlikely(!txdesc->iv_len))
109 return;
110
111 /* Copy IV/EIV data */
112 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
113}
114
115void rt2x00crypto_tx_remove_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
116{
117 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
118
119 if (unlikely(!txdesc->iv_len))
120 return;
121
122 /* Copy IV/EIV data */
123 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
124
125 /* Move ieee80211 header */
126 memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
127
128 /* Pull buffer to correct size */
129 skb_pull(skb, txdesc->iv_len);
130 txdesc->length -= txdesc->iv_len;
131
132 /* IV/EIV data has officially been stripped */
133 skbdesc->flags |= SKBDESC_IV_STRIPPED;
134}
135
136void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
137{
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);
141
142 if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
143 return;
144
145 skb_push(skb, iv_len);
146
147 /* Move ieee80211 header */
148 memmove(skb->data, skb->data + iv_len, header_length);
149
150 /* Copy IV/EIV data */
151 memcpy(skb->data + header_length, skbdesc->iv, iv_len);
152
153 /* IV/EIV data has returned into the frame */
154 skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
155}
156
157void rt2x00crypto_rx_insert_iv(struct sk_buff *skb,
158 unsigned int header_length,
159 struct rxdone_entry_desc *rxdesc)
160{
161 unsigned int payload_len = rxdesc->size - header_length;
162 unsigned int align = ALIGN_SIZE(skb, header_length);
163 unsigned int iv_len;
164 unsigned int icv_len;
165 unsigned int transfer = 0;
166
167 /*
168 * WEP64/WEP128: Provides IV & ICV
169 * TKIP: Provides IV/EIV & ICV
170 * AES: Provies IV/EIV & ICV
171 */
172 switch (rxdesc->cipher) {
173 case CIPHER_WEP64:
174 case CIPHER_WEP128:
175 iv_len = 4;
176 icv_len = 4;
177 break;
178 case CIPHER_TKIP:
179 iv_len = 8;
180 icv_len = 4;
181 break;
182 case CIPHER_AES:
183 iv_len = 8;
184 icv_len = 8;
185 break;
186 default:
187 /* Unsupport type */
188 return;
189 }
190
191 /*
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
197 * for the iv data.
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.
201 */
202 if (rxdesc->dev_flags & RXDONE_L2PAD) {
203 skb_push(skb, iv_len - align);
204 skb_put(skb, icv_len);
205
206 /* Move ieee80211 header */
207 memmove(skb->data + transfer,
208 skb->data + transfer + (iv_len - align),
209 header_length);
210 transfer += header_length;
211 } else {
212 skb_push(skb, iv_len + align);
213 if (align < icv_len)
214 skb_put(skb, icv_len - align);
215 else if (align > icv_len)
216 skb_trim(skb, rxdesc->size + iv_len + icv_len);
217
218 /* Move ieee80211 header */
219 memmove(skb->data + transfer,
220 skb->data + transfer + iv_len + align,
221 header_length);
222 transfer += header_length;
223 }
224
225 /* Copy IV/EIV data */
226 memcpy(skb->data + transfer, rxdesc->iv, iv_len);
227 transfer += iv_len;
228
229 /*
230 * Move payload for alignment purposes. Note that
231 * this is only needed when no l2 padding is present.
232 */
233 if (!(rxdesc->dev_flags & RXDONE_L2PAD)) {
234 memmove(skb->data + transfer,
235 skb->data + transfer + align,
236 payload_len);
237 }
238
239 /*
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.
243 */
244 transfer += payload_len;
245
246 /*
247 * Copy ICV data
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.
251 */
252 memcpy(skb->data + transfer, &rxdesc->icv, 4);
253 transfer += icv_len;
254
255 /* IV/EIV/ICV has been inserted into frame */
256 rxdesc->size = transfer;
257 rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
258}
1/*
2 Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
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, see <http://www.gnu.org/licenses/>.
17 */
18
19/*
20 Module: rt2x00lib
21 Abstract: rt2x00 crypto specific routines.
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26
27#include "rt2x00.h"
28#include "rt2x00lib.h"
29
30enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
31{
32 switch (key->cipher) {
33 case WLAN_CIPHER_SUITE_WEP40:
34 return CIPHER_WEP64;
35 case WLAN_CIPHER_SUITE_WEP104:
36 return CIPHER_WEP128;
37 case WLAN_CIPHER_SUITE_TKIP:
38 return CIPHER_TKIP;
39 case WLAN_CIPHER_SUITE_CCMP:
40 return CIPHER_AES;
41 default:
42 return CIPHER_NONE;
43 }
44}
45
46void rt2x00crypto_create_tx_descriptor(struct rt2x00_dev *rt2x00dev,
47 struct sk_buff *skb,
48 struct txentry_desc *txdesc)
49{
50 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
51 struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
52
53 if (!rt2x00_has_cap_hw_crypto(rt2x00dev) || !hw_key)
54 return;
55
56 __set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
57
58 txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
59
60 if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
61 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
62
63 txdesc->key_idx = hw_key->hw_key_idx;
64 txdesc->iv_offset = txdesc->header_length;
65 txdesc->iv_len = hw_key->iv_len;
66
67 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
68 __set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
69
70 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
71 __set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
72}
73
74unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
75 struct sk_buff *skb)
76{
77 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
78 struct ieee80211_key_conf *key = tx_info->control.hw_key;
79 unsigned int overhead = 0;
80
81 if (!rt2x00_has_cap_hw_crypto(rt2x00dev) || !key)
82 return overhead;
83
84 /*
85 * Extend frame length to include IV/EIV/ICV/MMIC,
86 * note that these lengths should only be added when
87 * mac80211 does not generate it.
88 */
89 overhead += key->icv_len;
90
91 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
92 overhead += key->iv_len;
93
94 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
95 if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
96 overhead += 8;
97 }
98
99 return overhead;
100}
101
102void rt2x00crypto_tx_copy_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
103{
104 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
105
106 if (unlikely(!txdesc->iv_len))
107 return;
108
109 /* Copy IV/EIV data */
110 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
111}
112
113void rt2x00crypto_tx_remove_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
114{
115 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
116
117 if (unlikely(!txdesc->iv_len))
118 return;
119
120 /* Copy IV/EIV data */
121 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
122
123 /* Move ieee80211 header */
124 memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
125
126 /* Pull buffer to correct size */
127 skb_pull(skb, txdesc->iv_len);
128 txdesc->length -= txdesc->iv_len;
129
130 /* IV/EIV data has officially been stripped */
131 skbdesc->flags |= SKBDESC_IV_STRIPPED;
132}
133
134void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
135{
136 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
137 const unsigned int iv_len =
138 ((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4);
139
140 if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
141 return;
142
143 skb_push(skb, iv_len);
144
145 /* Move ieee80211 header */
146 memmove(skb->data, skb->data + iv_len, header_length);
147
148 /* Copy IV/EIV data */
149 memcpy(skb->data + header_length, skbdesc->iv, iv_len);
150
151 /* IV/EIV data has returned into the frame */
152 skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
153}
154
155void rt2x00crypto_rx_insert_iv(struct sk_buff *skb,
156 unsigned int header_length,
157 struct rxdone_entry_desc *rxdesc)
158{
159 unsigned int payload_len = rxdesc->size - header_length;
160 unsigned int align = ALIGN_SIZE(skb, header_length);
161 unsigned int iv_len;
162 unsigned int icv_len;
163 unsigned int transfer = 0;
164
165 /*
166 * WEP64/WEP128: Provides IV & ICV
167 * TKIP: Provides IV/EIV & ICV
168 * AES: Provies IV/EIV & ICV
169 */
170 switch (rxdesc->cipher) {
171 case CIPHER_WEP64:
172 case CIPHER_WEP128:
173 iv_len = 4;
174 icv_len = 4;
175 break;
176 case CIPHER_TKIP:
177 iv_len = 8;
178 icv_len = 4;
179 break;
180 case CIPHER_AES:
181 iv_len = 8;
182 icv_len = 8;
183 break;
184 default:
185 /* Unsupport type */
186 return;
187 }
188
189 /*
190 * Make room for new data. There are 2 possibilities
191 * either the alignment is already present between
192 * the 802.11 header and payload. In that case we
193 * we have to move the header less then the iv_len
194 * since we can use the already available l2pad bytes
195 * for the iv data.
196 * When the alignment must be added manually we must
197 * move the header more then iv_len since we must
198 * make room for the payload move as well.
199 */
200 if (rxdesc->dev_flags & RXDONE_L2PAD) {
201 skb_push(skb, iv_len - align);
202 skb_put(skb, icv_len);
203
204 /* Move ieee80211 header */
205 memmove(skb->data + transfer,
206 skb->data + transfer + (iv_len - align),
207 header_length);
208 transfer += header_length;
209 } else {
210 skb_push(skb, iv_len + align);
211 if (align < icv_len)
212 skb_put(skb, icv_len - align);
213 else if (align > icv_len)
214 skb_trim(skb, rxdesc->size + iv_len + icv_len);
215
216 /* Move ieee80211 header */
217 memmove(skb->data + transfer,
218 skb->data + transfer + iv_len + align,
219 header_length);
220 transfer += header_length;
221 }
222
223 /* Copy IV/EIV data */
224 memcpy(skb->data + transfer, rxdesc->iv, iv_len);
225 transfer += iv_len;
226
227 /*
228 * Move payload for alignment purposes. Note that
229 * this is only needed when no l2 padding is present.
230 */
231 if (!(rxdesc->dev_flags & RXDONE_L2PAD)) {
232 memmove(skb->data + transfer,
233 skb->data + transfer + align,
234 payload_len);
235 }
236
237 /*
238 * NOTE: Always count the payload as transferred,
239 * even when alignment was set to zero. This is required
240 * for determining the correct offset for the ICV data.
241 */
242 transfer += payload_len;
243
244 /*
245 * Copy ICV data
246 * AES appends 8 bytes, we can't fill the upper
247 * 4 bytes, but mac80211 doesn't care about what
248 * we provide here anyway and strips it immediately.
249 */
250 memcpy(skb->data + transfer, &rxdesc->icv, 4);
251 transfer += icv_len;
252
253 /* IV/EIV/ICV has been inserted into frame */
254 rxdesc->size = transfer;
255 rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
256}