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