blob: bed42a48408c6cc71cf4a47ba5bd897603cfaf7b [file] [log] [blame]
Phoebe Buckheister94b4f6c2014-03-14 21:24:00 +01001/*
2 * Copyright (C) 2014 Fraunhofer ITWM
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * Written by:
14 * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
15 */
16
17#include <net/mac802154.h>
18#include <net/ieee802154.h>
19#include <net/ieee802154_netdev.h>
20
21static int
22ieee802154_hdr_push_addr(u8 *buf, const struct ieee802154_addr *addr,
23 bool omit_pan)
24{
25 int pos = 0;
26
27 if (addr->mode == IEEE802154_ADDR_NONE)
28 return 0;
29
30 if (!omit_pan) {
31 memcpy(buf + pos, &addr->pan_id, 2);
32 pos += 2;
33 }
34
35 switch (addr->mode) {
36 case IEEE802154_ADDR_SHORT:
37 memcpy(buf + pos, &addr->short_addr, 2);
38 pos += 2;
39 break;
40
41 case IEEE802154_ADDR_LONG:
42 memcpy(buf + pos, &addr->extended_addr, IEEE802154_ADDR_LEN);
43 pos += IEEE802154_ADDR_LEN;
44 break;
45
46 default:
47 return -EINVAL;
48 }
49
50 return pos;
51}
52
53static int
54ieee802154_hdr_push_sechdr(u8 *buf, const struct ieee802154_sechdr *hdr)
55{
56 int pos = 5;
57
58 memcpy(buf, hdr, 1);
59 memcpy(buf + 1, &hdr->frame_counter, 4);
60
61 switch (hdr->key_id_mode) {
62 case IEEE802154_SCF_KEY_IMPLICIT:
63 return pos;
64
65 case IEEE802154_SCF_KEY_INDEX:
66 break;
67
68 case IEEE802154_SCF_KEY_SHORT_INDEX:
69 memcpy(buf + pos, &hdr->short_src, 4);
70 pos += 4;
71 break;
72
73 case IEEE802154_SCF_KEY_HW_INDEX:
74 memcpy(buf + pos, &hdr->extended_src, IEEE802154_ADDR_LEN);
75 pos += IEEE802154_ADDR_LEN;
76 break;
77 }
78
79 buf[pos++] = hdr->key_id;
80
81 return pos;
82}
83
84int
85ieee802154_hdr_push(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
86{
87 u8 buf[MAC802154_FRAME_HARD_HEADER_LEN];
88 int pos = 2;
89 int rc;
90 struct ieee802154_hdr_fc fc = hdr->fc;
91
92 buf[pos++] = hdr->seq;
93
94 fc.dest_addr_mode = hdr->dest.mode;
95
96 rc = ieee802154_hdr_push_addr(buf + pos, &hdr->dest, false);
97 if (rc < 0)
98 return -EINVAL;
99 pos += rc;
100
101 fc.source_addr_mode = hdr->source.mode;
102
103 if (hdr->source.pan_id == hdr->dest.pan_id &&
104 hdr->dest.mode != IEEE802154_ADDR_NONE)
105 fc.intra_pan = true;
106
107 rc = ieee802154_hdr_push_addr(buf + pos, &hdr->source, fc.intra_pan);
108 if (rc < 0)
109 return -EINVAL;
110 pos += rc;
111
112 if (fc.security_enabled) {
113 fc.version = 1;
114
115 rc = ieee802154_hdr_push_sechdr(buf + pos, &hdr->sec);
116 if (rc < 0)
117 return -EINVAL;
118
119 pos += rc;
120 }
121
122 memcpy(buf, &fc, 2);
123
124 memcpy(skb_push(skb, pos), buf, pos);
125
126 return pos;
127}
128EXPORT_SYMBOL_GPL(ieee802154_hdr_push);
129
130static int
131ieee802154_hdr_get_addr(const u8 *buf, int mode, bool omit_pan,
132 struct ieee802154_addr *addr)
133{
134 int pos = 0;
135
136 addr->mode = mode;
137
138 if (mode == IEEE802154_ADDR_NONE)
139 return 0;
140
141 if (!omit_pan) {
142 memcpy(&addr->pan_id, buf + pos, 2);
143 pos += 2;
144 }
145
146 if (mode == IEEE802154_ADDR_SHORT) {
147 memcpy(&addr->short_addr, buf + pos, 2);
148 return pos + 2;
149 } else {
150 memcpy(&addr->extended_addr, buf + pos, IEEE802154_ADDR_LEN);
151 return pos + IEEE802154_ADDR_LEN;
152 }
153}
154
155static int ieee802154_hdr_addr_len(int mode, bool omit_pan)
156{
157 int pan_len = omit_pan ? 0 : 2;
158
159 switch (mode) {
160 case IEEE802154_ADDR_NONE: return 0;
161 case IEEE802154_ADDR_SHORT: return 2 + pan_len;
162 case IEEE802154_ADDR_LONG: return IEEE802154_ADDR_LEN + pan_len;
163 default: return -EINVAL;
164 }
165}
166
167static int
168ieee802154_hdr_get_sechdr(const u8 *buf, struct ieee802154_sechdr *hdr)
169{
170 int pos = 5;
171
172 memcpy(hdr, buf, 1);
173 memcpy(&hdr->frame_counter, buf + 1, 4);
174
175 switch (hdr->key_id_mode) {
176 case IEEE802154_SCF_KEY_IMPLICIT:
177 return pos;
178
179 case IEEE802154_SCF_KEY_INDEX:
180 break;
181
182 case IEEE802154_SCF_KEY_SHORT_INDEX:
183 memcpy(&hdr->short_src, buf + pos, 4);
184 pos += 4;
185 break;
186
187 case IEEE802154_SCF_KEY_HW_INDEX:
188 memcpy(&hdr->extended_src, buf + pos, IEEE802154_ADDR_LEN);
189 pos += IEEE802154_ADDR_LEN;
190 break;
191 }
192
193 hdr->key_id = buf[pos++];
194
195 return pos;
196}
197
198static int ieee802154_hdr_sechdr_len(u8 sc)
199{
200 switch (IEEE802154_SCF_KEY_ID_MODE(sc)) {
201 case IEEE802154_SCF_KEY_IMPLICIT: return 5;
202 case IEEE802154_SCF_KEY_INDEX: return 6;
203 case IEEE802154_SCF_KEY_SHORT_INDEX: return 10;
204 case IEEE802154_SCF_KEY_HW_INDEX: return 14;
205 default: return -EINVAL;
206 }
207}
208
209static int ieee802154_hdr_minlen(const struct ieee802154_hdr *hdr)
210{
211 int dlen, slen;
212
213 dlen = ieee802154_hdr_addr_len(hdr->fc.dest_addr_mode, false);
214 slen = ieee802154_hdr_addr_len(hdr->fc.source_addr_mode,
215 hdr->fc.intra_pan);
216
217 if (slen < 0 || dlen < 0)
218 return -EINVAL;
219
220 return 3 + dlen + slen + hdr->fc.security_enabled;
221}
222
223static int
224ieee802154_hdr_get_addrs(const u8 *buf, struct ieee802154_hdr *hdr)
225{
226 int pos = 0;
227
228 pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.dest_addr_mode,
229 false, &hdr->dest);
230 pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.source_addr_mode,
231 hdr->fc.intra_pan, &hdr->source);
232
233 if (hdr->fc.intra_pan)
234 hdr->source.pan_id = hdr->dest.pan_id;
235
236 return pos;
237}
238
239int
240ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr)
241{
242 int pos = 3, rc;
243
244 if (!pskb_may_pull(skb, 3))
245 return -EINVAL;
246
247 memcpy(hdr, skb->data, 3);
248
249 rc = ieee802154_hdr_minlen(hdr);
250 if (rc < 0 || !pskb_may_pull(skb, rc))
251 return -EINVAL;
252
253 pos += ieee802154_hdr_get_addrs(skb->data + pos, hdr);
254
255 if (hdr->fc.security_enabled) {
256 int want = pos + ieee802154_hdr_sechdr_len(skb->data[pos]);
257
258 if (!pskb_may_pull(skb, want))
259 return -EINVAL;
260
261 pos += ieee802154_hdr_get_sechdr(skb->data + pos, &hdr->sec);
262 }
263
264 skb_pull(skb, pos);
265 return pos;
266}
267EXPORT_SYMBOL_GPL(ieee802154_hdr_pull);
268
269int
270ieee802154_hdr_peek_addrs(const struct sk_buff *skb, struct ieee802154_hdr *hdr)
271{
272 const u8 *buf = skb_mac_header(skb);
273 int pos = 3, rc;
274
275 if (buf + 3 > skb_tail_pointer(skb))
276 return -EINVAL;
277
278 memcpy(hdr, buf, 3);
279
280 rc = ieee802154_hdr_minlen(hdr);
281 if (rc < 0 || buf + rc > skb_tail_pointer(skb))
282 return -EINVAL;
283
284 pos += ieee802154_hdr_get_addrs(buf + pos, hdr);
285 return pos;
286}
287EXPORT_SYMBOL_GPL(ieee802154_hdr_peek_addrs);