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: buf + pos, addr: &hdr->dest, omit_pan: 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: buf + pos, addr: &hdr->source, omit_pan: 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: buf + pos, hdr: &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, len: 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, data: mac_pl, len: sizeof(*mac_pl)); |
140 | skb_put_data(skb, data: pl, len: 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, len: 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, data: mac_pl, len: 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(mode: hdr->fc.dest_addr_mode, omit_pan: false); |
255 | slen = ieee802154_hdr_addr_len(mode: hdr->fc.source_addr_mode, |
256 | omit_pan: 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: buf + pos, mode: hdr->fc.dest_addr_mode, |
270 | omit_pan: false, addr: &hdr->dest); |
271 | pos += ieee802154_hdr_get_addr(buf: buf + pos, mode: hdr->fc.source_addr_mode, |
272 | omit_pan: hdr->fc.intra_pan, addr: &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, len: 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, len: rc)) |
292 | return -EINVAL; |
293 | |
294 | pos += ieee802154_hdr_get_addrs(buf: skb->data + pos, hdr); |
295 | |
296 | if (hdr->fc.security_enabled) { |
297 | int want = pos + ieee802154_hdr_sechdr_len(sc: skb->data[pos]); |
298 | |
299 | if (!pskb_may_pull(skb, len: want)) |
300 | return -EINVAL; |
301 | |
302 | pos += ieee802154_hdr_get_sechdr(buf: skb->data + pos, hdr: &hdr->sec); |
303 | } |
304 | |
305 | skb_pull(skb, len: 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, len: sizeof(*mac_pl))) |
314 | return -EINVAL; |
315 | |
316 | memcpy(mac_pl, skb->data, sizeof(*mac_pl)); |
317 | skb_pull(skb, len: 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: 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: buf + pos, hdr: &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(sec: &hdr->sec); |
374 | } |
375 | |
376 | return IEEE802154_MTU - hlen - IEEE802154_MFR_SIZE; |
377 | } |
378 | EXPORT_SYMBOL_GPL(ieee802154_max_payload); |
379 | |