1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2014 Fraunhofer ITWM
4 *
5 * Written by:
6 * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
7 */
8
9 #include <linux/ieee802154.h>
10
11 #include <net/mac802154.h>
12 #include <net/ieee802154_netdev.h>
13
14 static int
15 ieee802154_hdr_push_addr(u8 *buf, const struct ieee802154_addr *addr,
16 bool omit_pan)
17 {
18 int pos = 0;
19
20 if (addr->mode == IEEE802154_ADDR_NONE)
21 return 0;
22
23 if (!omit_pan) {
24 memcpy(buf + pos, &addr->pan_id, 2);
25 pos += 2;
26 }
27
28 switch (addr->mode) {
29 case IEEE802154_ADDR_SHORT:
30 memcpy(buf + pos, &addr->short_addr, 2);
31 pos += 2;
32 break;
33
34 case IEEE802154_ADDR_LONG:
35 memcpy(buf + pos, &addr->extended_addr, IEEE802154_ADDR_LEN);
36 pos += IEEE802154_ADDR_LEN;
37 break;
38
39 default:
40 return -EINVAL;
41 }
42
43 return pos;
44 }
45
46 static int
47 ieee802154_hdr_push_sechdr(u8 *buf, const struct ieee802154_sechdr *hdr)
48 {
49 int pos = 5;
50
51 memcpy(buf, hdr, 1);
52 memcpy(buf + 1, &hdr->frame_counter, 4);
53
54 switch (hdr->key_id_mode) {
55 case IEEE802154_SCF_KEY_IMPLICIT:
56 return pos;
57
58 case IEEE802154_SCF_KEY_INDEX:
59 break;
60
61 case IEEE802154_SCF_KEY_SHORT_INDEX:
62 memcpy(buf + pos, &hdr->short_src, 4);
63 pos += 4;
64 break;
65
66 case IEEE802154_SCF_KEY_HW_INDEX:
67 memcpy(buf + pos, &hdr->extended_src, IEEE802154_ADDR_LEN);
68 pos += IEEE802154_ADDR_LEN;
69 break;
70 }
71
72 buf[pos++] = hdr->key_id;
73
74 return pos;
75 }
76
77 int
78 ieee802154_hdr_push(struct sk_buff *skb, struct ieee802154_hdr *hdr)
79 {
80 u8 buf[IEEE802154_MAX_HEADER_LEN];
81 int pos = 2;
82 int rc;
83 struct ieee802154_hdr_fc *fc = &hdr->fc;
84
85 buf[pos++] = hdr->seq;
86
87 fc->dest_addr_mode = hdr->dest.mode;
88
89 rc = ieee802154_hdr_push_addr(buf + pos, &hdr->dest, false);
90 if (rc < 0)
91 return -EINVAL;
92 pos += rc;
93
94 fc->source_addr_mode = hdr->source.mode;
95
96 if (hdr->source.pan_id == hdr->dest.pan_id &&
97 hdr->dest.mode != IEEE802154_ADDR_NONE)
98 fc->intra_pan = true;
99
100 rc = ieee802154_hdr_push_addr(buf + pos, &hdr->source, fc->intra_pan);
101 if (rc < 0)
102 return -EINVAL;
103 pos += rc;
104
105 if (fc->security_enabled) {
106 fc->version = 1;
107
108 rc = ieee802154_hdr_push_sechdr(buf + pos, &hdr->sec);
109 if (rc < 0)
110 return -EINVAL;
111
112 pos += rc;
113 }
114
115 memcpy(buf, fc, 2);
116
117 memcpy(skb_push(skb, pos), buf, pos);
118
119 return pos;
120 }
121 EXPORT_SYMBOL_GPL(ieee802154_hdr_push);
122
123 int ieee802154_mac_cmd_push(struct sk_buff *skb, void *f,
124 const void *pl, unsigned int pl_len)
125 {
126 struct ieee802154_mac_cmd_frame *frame = f;
127 struct ieee802154_mac_cmd_pl *mac_pl = &frame->mac_pl;
128 struct ieee802154_hdr *mhr = &frame->mhr;
129 int ret;
130
131 skb_reserve(skb, sizeof(*mhr));
132 ret = ieee802154_hdr_push(skb, mhr);
133 if (ret < 0)
134 return ret;
135
136 skb_reset_mac_header(skb);
137 skb->mac_len = ret;
138
139 skb_put_data(skb, mac_pl, sizeof(*mac_pl));
140 skb_put_data(skb, pl, pl_len);
141
142 return 0;
143 }
144 EXPORT_SYMBOL_GPL(ieee802154_mac_cmd_push);
145
146 int ieee802154_beacon_push(struct sk_buff *skb,
147 struct ieee802154_beacon_frame *beacon)
148 {
149 struct ieee802154_beacon_hdr *mac_pl = &beacon->mac_pl;
150 struct ieee802154_hdr *mhr = &beacon->mhr;
151 int ret;
152
153 skb_reserve(skb, sizeof(*mhr));
154 ret = ieee802154_hdr_push(skb, mhr);
155 if (ret < 0)
156 return ret;
157
158 skb_reset_mac_header(skb);
159 skb->mac_len = ret;
160
161 skb_put_data(skb, mac_pl, sizeof(*mac_pl));
162
163 if (mac_pl->pend_short_addr_count || mac_pl->pend_ext_addr_count)
164 return -EOPNOTSUPP;
165
166 return 0;
167 }
168 EXPORT_SYMBOL_GPL(ieee802154_beacon_push);
169
170 static int
171 ieee802154_hdr_get_addr(const u8 *buf, int mode, bool omit_pan,
172 struct ieee802154_addr *addr)
173 {
174 int pos = 0;
175
176 addr->mode = mode;
177
178 if (mode == IEEE802154_ADDR_NONE)
179 return 0;
180
181 if (!omit_pan) {
182 memcpy(&addr->pan_id, buf + pos, 2);
183 pos += 2;
184 }
185
186 if (mode == IEEE802154_ADDR_SHORT) {
187 memcpy(&addr->short_addr, buf + pos, 2);
188 return pos + 2;
189 } else {
190 memcpy(&addr->extended_addr, buf + pos, IEEE802154_ADDR_LEN);
191 return pos + IEEE802154_ADDR_LEN;
192 }
193 }
194
195 static int ieee802154_hdr_addr_len(int mode, bool omit_pan)
196 {
197 int pan_len = omit_pan ? 0 : 2;
198
199 switch (mode) {
200 case IEEE802154_ADDR_NONE: return 0;
201 case IEEE802154_ADDR_SHORT: return 2 + pan_len;
202 case IEEE802154_ADDR_LONG: return IEEE802154_ADDR_LEN + pan_len;
203 default: return -EINVAL;
204 }
205 }
206
207 static int
208 ieee802154_hdr_get_sechdr(const u8 *buf, struct ieee802154_sechdr *hdr)
209 {
210 int pos = 5;
211
212 memcpy(hdr, buf, 1);
213 memcpy(&hdr->frame_counter, buf + 1, 4);
214
215 switch (hdr->key_id_mode) {
216 case IEEE802154_SCF_KEY_IMPLICIT:
217 return pos;
218
219 case IEEE802154_SCF_KEY_INDEX:
220 break;
221
222 case IEEE802154_SCF_KEY_SHORT_INDEX:
223 memcpy(&hdr->short_src, buf + pos, 4);
224 pos += 4;
225 break;
226
227 case IEEE802154_SCF_KEY_HW_INDEX:
228 memcpy(&hdr->extended_src, buf + pos, IEEE802154_ADDR_LEN);
229 pos += IEEE802154_ADDR_LEN;
230 break;
231 }
232
233 hdr->key_id = buf[pos++];
234
235 return pos;
236 }
237
238 static int ieee802154_sechdr_lengths[4] = {
239 [IEEE802154_SCF_KEY_IMPLICIT] = 5,
240 [IEEE802154_SCF_KEY_INDEX] = 6,
241 [IEEE802154_SCF_KEY_SHORT_INDEX] = 10,
242 [IEEE802154_SCF_KEY_HW_INDEX] = 14,
243 };
244
245 static int ieee802154_hdr_sechdr_len(u8 sc)
246 {
247 return ieee802154_sechdr_lengths[IEEE802154_SCF_KEY_ID_MODE(sc)];
248 }
249
250 static int ieee802154_hdr_minlen(const struct ieee802154_hdr *hdr)
251 {
252 int dlen, slen;
253
254 dlen = ieee802154_hdr_addr_len(hdr->fc.dest_addr_mode, false);
255 slen = ieee802154_hdr_addr_len(hdr->fc.source_addr_mode,
256 hdr->fc.intra_pan);
257
258 if (slen < 0 || dlen < 0)
259 return -EINVAL;
260
261 return 3 + dlen + slen + hdr->fc.security_enabled;
262 }
263
264 static int
265 ieee802154_hdr_get_addrs(const u8 *buf, struct ieee802154_hdr *hdr)
266 {
267 int pos = 0;
268
269 pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.dest_addr_mode,
270 false, &hdr->dest);
271 pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.source_addr_mode,
272 hdr->fc.intra_pan, &hdr->source);
273
274 if (hdr->fc.intra_pan)
275 hdr->source.pan_id = hdr->dest.pan_id;
276
277 return pos;
278 }
279
280 int
281 ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr)
282 {
283 int pos = 3, rc;
284
285 if (!pskb_may_pull(skb, 3))
286 return -EINVAL;
287
288 memcpy(hdr, skb->data, 3);
289
290 rc = ieee802154_hdr_minlen(hdr);
291 if (rc < 0 || !pskb_may_pull(skb, rc))
292 return -EINVAL;
293
294 pos += ieee802154_hdr_get_addrs(skb->data + pos, hdr);
295
296 if (hdr->fc.security_enabled) {
297 int want = pos + ieee802154_hdr_sechdr_len(skb->data[pos]);
298
299 if (!pskb_may_pull(skb, want))
300 return -EINVAL;
301
302 pos += ieee802154_hdr_get_sechdr(skb->data + pos, &hdr->sec);
303 }
304
305 skb_pull(skb, pos);
306 return pos;
307 }
308 EXPORT_SYMBOL_GPL(ieee802154_hdr_pull);
309
310 int ieee802154_mac_cmd_pl_pull(struct sk_buff *skb,
311 struct ieee802154_mac_cmd_pl *mac_pl)
312 {
313 if (!pskb_may_pull(skb, sizeof(*mac_pl)))
314 return -EINVAL;
315
316 memcpy(mac_pl, skb->data, sizeof(*mac_pl));
317 skb_pull(skb, sizeof(*mac_pl));
318
319 return 0;
320 }
321 EXPORT_SYMBOL_GPL(ieee802154_mac_cmd_pl_pull);
322
323 int
324 ieee802154_hdr_peek_addrs(const struct sk_buff *skb, struct ieee802154_hdr *hdr)
325 {
326 const u8 *buf = skb_mac_header(skb);
327 int pos = 3, rc;
328
329 if (buf + 3 > skb_tail_pointer(skb))
330 return -EINVAL;
331
332 memcpy(hdr, buf, 3);
333
334 rc = ieee802154_hdr_minlen(hdr);
335 if (rc < 0 || buf + rc > skb_tail_pointer(skb))
336 return -EINVAL;
337
338 pos += ieee802154_hdr_get_addrs(buf + pos, hdr);
339 return pos;
340 }
341 EXPORT_SYMBOL_GPL(ieee802154_hdr_peek_addrs);
342
343 int
344 ieee802154_hdr_peek(const struct sk_buff *skb, struct ieee802154_hdr *hdr)
345 {
346 const u8 *buf = skb_mac_header(skb);
347 int pos;
348
349 pos = ieee802154_hdr_peek_addrs(skb, hdr);
350 if (pos < 0)
351 return -EINVAL;
352
353 if (hdr->fc.security_enabled) {
354 u8 key_id_mode = IEEE802154_SCF_KEY_ID_MODE(*(buf + pos));
355 int want = pos + ieee802154_sechdr_lengths[key_id_mode];
356
357 if (buf + want > skb_tail_pointer(skb))
358 return -EINVAL;
359
360 pos += ieee802154_hdr_get_sechdr(buf + pos, &hdr->sec);
361 }
362
363 return pos;
364 }
365 EXPORT_SYMBOL_GPL(ieee802154_hdr_peek);
366
367 int ieee802154_max_payload(const struct ieee802154_hdr *hdr)
368 {
369 int hlen = ieee802154_hdr_minlen(hdr);
370
371 if (hdr->fc.security_enabled) {
372 hlen += ieee802154_sechdr_lengths[hdr->sec.key_id_mode] - 1;
373 hlen += ieee802154_sechdr_authtag_len(&hdr->sec);
374 }
375
376 return IEEE802154_MTU - hlen - IEEE802154_MFR_SIZE;
377 }
378 EXPORT_SYMBOL_GPL(ieee802154_max_payload);
379
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