]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - drivers/net/wireless/rt2x00/rt2x00crypto.c
wireless: move some utility functions from mac80211 to cfg80211
[mirror_ubuntu-bionic-kernel.git] / drivers / net / wireless / rt2x00 / rt2x00crypto.c
1 /*
2 Copyright (C) 2004 - 2009 rt2x00 SourceForge Project
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
32 enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key)
33 {
34 switch (key->alg) {
35 case ALG_WEP:
36 if (key->keylen == WLAN_KEY_LEN_WEP40)
37 return CIPHER_WEP64;
38 else
39 return CIPHER_WEP128;
40 case ALG_TKIP:
41 return CIPHER_TKIP;
42 case ALG_CCMP:
43 return CIPHER_AES;
44 default:
45 return CIPHER_NONE;
46 }
47 }
48
49 void rt2x00crypto_create_tx_descriptor(struct queue_entry *entry,
50 struct txentry_desc *txdesc)
51 {
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;
55
56 if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) ||
57 !hw_key || entry->skb->do_not_encrypt)
58 return;
59
60 __set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags);
61
62 txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key);
63
64 if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
65 __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags);
66
67 txdesc->key_idx = hw_key->hw_key_idx;
68 txdesc->iv_offset = txdesc->header_length;
69 txdesc->iv_len = hw_key->iv_len;
70
71 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
72 __set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags);
73
74 if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
75 __set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags);
76 }
77
78 unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev,
79 struct sk_buff *skb)
80 {
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;
84
85 if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) ||
86 !key || skb->do_not_encrypt)
87 return overhead;
88
89 /*
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.
93 */
94 overhead += key->icv_len;
95
96 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
97 overhead += key->iv_len;
98
99 if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
100 if (key->alg == ALG_TKIP)
101 overhead += 8;
102 }
103
104 return overhead;
105 }
106
107 void rt2x00crypto_tx_copy_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
108 {
109 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
110
111 if (unlikely(!txdesc->iv_len))
112 return;
113
114 /* Copy IV/EIV data */
115 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
116 }
117
118 void rt2x00crypto_tx_remove_iv(struct sk_buff *skb, struct txentry_desc *txdesc)
119 {
120 struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
121
122 if (unlikely(!txdesc->iv_len))
123 return;
124
125 /* Copy IV/EIV data */
126 memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len);
127
128 /* Move ieee80211 header */
129 memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset);
130
131 /* Pull buffer to correct size */
132 skb_pull(skb, txdesc->iv_len);
133
134 /* IV/EIV data has officially be stripped */
135 skbdesc->flags |= SKBDESC_IV_STRIPPED;
136 }
137
138 void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length)
139 {
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);
143
144 if (!(skbdesc->flags & SKBDESC_IV_STRIPPED))
145 return;
146
147 skb_push(skb, iv_len);
148
149 /* Move ieee80211 header */
150 memmove(skb->data, skb->data + iv_len, header_length);
151
152 /* Copy IV/EIV data */
153 memcpy(skb->data + header_length, skbdesc->iv, iv_len);
154
155 /* IV/EIV data has returned into the frame */
156 skbdesc->flags &= ~SKBDESC_IV_STRIPPED;
157 }
158
159 void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, bool l2pad,
160 unsigned int header_length,
161 struct rxdone_entry_desc *rxdesc)
162 {
163 unsigned int payload_len = rxdesc->size - header_length;
164 unsigned int align = ALIGN_SIZE(skb, header_length);
165 unsigned int iv_len;
166 unsigned int icv_len;
167 unsigned int transfer = 0;
168
169 /*
170 * WEP64/WEP128: Provides IV & ICV
171 * TKIP: Provides IV/EIV & ICV
172 * AES: Provies IV/EIV & ICV
173 */
174 switch (rxdesc->cipher) {
175 case CIPHER_WEP64:
176 case CIPHER_WEP128:
177 iv_len = 4;
178 icv_len = 4;
179 break;
180 case CIPHER_TKIP:
181 iv_len = 8;
182 icv_len = 4;
183 break;
184 case CIPHER_AES:
185 iv_len = 8;
186 icv_len = 8;
187 break;
188 default:
189 /* Unsupport type */
190 return;
191 }
192
193 /*
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
199 * for the iv data.
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.
203 */
204 if (l2pad) {
205 skb_push(skb, iv_len - align);
206 skb_put(skb, icv_len);
207
208 /* Move ieee80211 header */
209 memmove(skb->data + transfer,
210 skb->data + transfer + (iv_len - align),
211 header_length);
212 transfer += header_length;
213 } else {
214 skb_push(skb, iv_len + align);
215 if (align < icv_len)
216 skb_put(skb, icv_len - align);
217 else if (align > icv_len)
218 skb_trim(skb, rxdesc->size + iv_len + icv_len);
219
220 /* Move ieee80211 header */
221 memmove(skb->data + transfer,
222 skb->data + transfer + iv_len + align,
223 header_length);
224 transfer += header_length;
225 }
226
227 /* Copy IV/EIV data */
228 memcpy(skb->data + transfer, rxdesc->iv, iv_len);
229 transfer += iv_len;
230
231 /*
232 * Move payload for alignment purposes. Note that
233 * this is only needed when no l2 padding is present.
234 */
235 if (!l2pad) {
236 memmove(skb->data + transfer,
237 skb->data + transfer + align,
238 payload_len);
239 }
240
241 /*
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.
245 */
246 transfer += payload_len;
247
248 /*
249 * Copy ICV data
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.
253 */
254 memcpy(skb->data + transfer, &rxdesc->icv, 4);
255 transfer += icv_len;
256
257 /* IV/EIV/ICV has been inserted into frame */
258 rxdesc->size = transfer;
259 rxdesc->flags &= ~RX_FLAG_IV_STRIPPED;
260 }