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1da177e4 LT |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License as published by | |
4 | * the Free Software Foundation; either version 2 of the License, or | |
5 | * (at your option) any later version. | |
6 | * | |
7 | * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) | |
8 | */ | |
9 | #include <linux/errno.h> | |
10 | #include <linux/types.h> | |
11 | #include <linux/socket.h> | |
12 | #include <linux/in.h> | |
13 | #include <linux/kernel.h> | |
70868eac | 14 | #include <linux/module.h> |
1da177e4 LT |
15 | #include <linux/timer.h> |
16 | #include <linux/string.h> | |
17 | #include <linux/sockios.h> | |
18 | #include <linux/net.h> | |
19 | #include <net/ax25.h> | |
20 | #include <linux/inet.h> | |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/skbuff.h> | |
23 | #include <net/sock.h> | |
24 | #include <asm/uaccess.h> | |
1da177e4 LT |
25 | #include <linux/fcntl.h> |
26 | #include <linux/mm.h> | |
27 | #include <linux/interrupt.h> | |
28 | ||
29 | /* | |
15b1c0e8 RB |
30 | * The default broadcast address of an interface is QST-0; the default address |
31 | * is LINUX-1. The null address is defined as a callsign of all spaces with | |
32 | * an SSID of zero. | |
1da177e4 | 33 | */ |
1da177e4 | 34 | |
15b1c0e8 RB |
35 | const ax25_address ax25_bcast = |
36 | {{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}}; | |
37 | const ax25_address ax25_defaddr = | |
38 | {{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}}; | |
39 | const ax25_address null_ax25_address = | |
40 | {{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}}; | |
41 | ||
42 | EXPORT_SYMBOL_GPL(ax25_bcast); | |
43 | EXPORT_SYMBOL_GPL(ax25_defaddr); | |
70868eac RB |
44 | EXPORT_SYMBOL(null_ax25_address); |
45 | ||
1da177e4 LT |
46 | /* |
47 | * ax25 -> ascii conversion | |
48 | */ | |
e8cc49bb | 49 | char *ax2asc(char *buf, const ax25_address *a) |
1da177e4 | 50 | { |
1da177e4 LT |
51 | char c, *s; |
52 | int n; | |
53 | ||
54 | for (n = 0, s = buf; n < 6; n++) { | |
55 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
56 | ||
57 | if (c != ' ') *s++ = c; | |
58 | } | |
59 | ||
60 | *s++ = '-'; | |
61 | ||
62 | if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { | |
63 | *s++ = '1'; | |
64 | n -= 10; | |
65 | } | |
66 | ||
67 | *s++ = n + '0'; | |
68 | *s++ = '\0'; | |
69 | ||
70 | if (*buf == '\0' || *buf == '-') | |
71 | return "*"; | |
72 | ||
73 | return buf; | |
74 | ||
75 | } | |
76 | ||
70868eac RB |
77 | EXPORT_SYMBOL(ax2asc); |
78 | ||
1da177e4 LT |
79 | /* |
80 | * ascii -> ax25 conversion | |
81 | */ | |
e8cc49bb | 82 | void asc2ax(ax25_address *addr, const char *callsign) |
1da177e4 | 83 | { |
f654c854 | 84 | const char *s; |
1da177e4 LT |
85 | int n; |
86 | ||
87 | for (s = callsign, n = 0; n < 6; n++) { | |
88 | if (*s != '\0' && *s != '-') | |
baed16a7 | 89 | addr->ax25_call[n] = *s++; |
1da177e4 | 90 | else |
baed16a7 RB |
91 | addr->ax25_call[n] = ' '; |
92 | addr->ax25_call[n] <<= 1; | |
93 | addr->ax25_call[n] &= 0xFE; | |
1da177e4 LT |
94 | } |
95 | ||
96 | if (*s++ == '\0') { | |
baed16a7 RB |
97 | addr->ax25_call[6] = 0x00; |
98 | return; | |
1da177e4 LT |
99 | } |
100 | ||
baed16a7 | 101 | addr->ax25_call[6] = *s++ - '0'; |
1da177e4 LT |
102 | |
103 | if (*s != '\0') { | |
baed16a7 RB |
104 | addr->ax25_call[6] *= 10; |
105 | addr->ax25_call[6] += *s++ - '0'; | |
1da177e4 LT |
106 | } |
107 | ||
baed16a7 RB |
108 | addr->ax25_call[6] <<= 1; |
109 | addr->ax25_call[6] &= 0x1E; | |
1da177e4 LT |
110 | } |
111 | ||
70868eac RB |
112 | EXPORT_SYMBOL(asc2ax); |
113 | ||
1da177e4 LT |
114 | /* |
115 | * Compare two ax.25 addresses | |
116 | */ | |
e8cc49bb | 117 | int ax25cmp(const ax25_address *a, const ax25_address *b) |
1da177e4 LT |
118 | { |
119 | int ct = 0; | |
120 | ||
121 | while (ct < 6) { | |
122 | if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */ | |
123 | return 1; | |
124 | ct++; | |
125 | } | |
126 | ||
528930b9 YH |
127 | if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */ |
128 | return 0; | |
1da177e4 | 129 | |
528930b9 | 130 | return 2; /* Partial match */ |
1da177e4 LT |
131 | } |
132 | ||
70868eac RB |
133 | EXPORT_SYMBOL(ax25cmp); |
134 | ||
1da177e4 LT |
135 | /* |
136 | * Compare two AX.25 digipeater paths. | |
137 | */ | |
e8cc49bb | 138 | int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2) |
1da177e4 LT |
139 | { |
140 | int i; | |
141 | ||
142 | if (digi1->ndigi != digi2->ndigi) | |
143 | return 1; | |
144 | ||
145 | if (digi1->lastrepeat != digi2->lastrepeat) | |
146 | return 1; | |
147 | ||
148 | for (i = 0; i < digi1->ndigi; i++) | |
149 | if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0) | |
150 | return 1; | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | /* | |
156 | * Given an AX.25 address pull of to, from, digi list, command/response and the start of data | |
157 | * | |
158 | */ | |
e8cc49bb RB |
159 | const unsigned char *ax25_addr_parse(const unsigned char *buf, int len, |
160 | ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, | |
161 | int *dama) | |
1da177e4 LT |
162 | { |
163 | int d = 0; | |
164 | ||
165 | if (len < 14) return NULL; | |
166 | ||
167 | if (flags != NULL) { | |
168 | *flags = 0; | |
169 | ||
170 | if (buf[6] & AX25_CBIT) | |
171 | *flags = AX25_COMMAND; | |
172 | if (buf[13] & AX25_CBIT) | |
173 | *flags = AX25_RESPONSE; | |
174 | } | |
175 | ||
176 | if (dama != NULL) | |
177 | *dama = ~buf[13] & AX25_DAMA_FLAG; | |
178 | ||
179 | /* Copy to, from */ | |
180 | if (dest != NULL) | |
181 | memcpy(dest, buf + 0, AX25_ADDR_LEN); | |
182 | if (src != NULL) | |
183 | memcpy(src, buf + 7, AX25_ADDR_LEN); | |
184 | ||
185 | buf += 2 * AX25_ADDR_LEN; | |
186 | len -= 2 * AX25_ADDR_LEN; | |
187 | ||
188 | digi->lastrepeat = -1; | |
189 | digi->ndigi = 0; | |
190 | ||
191 | while (!(buf[-1] & AX25_EBIT)) { | |
192 | if (d >= AX25_MAX_DIGIS) return NULL; /* Max of 6 digis */ | |
193 | if (len < 7) return NULL; /* Short packet */ | |
194 | ||
195 | memcpy(&digi->calls[d], buf, AX25_ADDR_LEN); | |
196 | digi->ndigi = d + 1; | |
197 | ||
198 | if (buf[6] & AX25_HBIT) { | |
199 | digi->repeated[d] = 1; | |
200 | digi->lastrepeat = d; | |
201 | } else { | |
202 | digi->repeated[d] = 0; | |
203 | } | |
204 | ||
205 | buf += AX25_ADDR_LEN; | |
206 | len -= AX25_ADDR_LEN; | |
207 | d++; | |
208 | } | |
209 | ||
210 | return buf; | |
211 | } | |
212 | ||
213 | /* | |
214 | * Assemble an AX.25 header from the bits | |
215 | */ | |
e8cc49bb RB |
216 | int ax25_addr_build(unsigned char *buf, const ax25_address *src, |
217 | const ax25_address *dest, const ax25_digi *d, int flag, int modulus) | |
1da177e4 LT |
218 | { |
219 | int len = 0; | |
220 | int ct = 0; | |
221 | ||
222 | memcpy(buf, dest, AX25_ADDR_LEN); | |
223 | buf[6] &= ~(AX25_EBIT | AX25_CBIT); | |
224 | buf[6] |= AX25_SSSID_SPARE; | |
225 | ||
226 | if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT; | |
227 | ||
228 | buf += AX25_ADDR_LEN; | |
229 | len += AX25_ADDR_LEN; | |
230 | ||
231 | memcpy(buf, src, AX25_ADDR_LEN); | |
232 | buf[6] &= ~(AX25_EBIT | AX25_CBIT); | |
233 | buf[6] &= ~AX25_SSSID_SPARE; | |
234 | ||
235 | if (modulus == AX25_MODULUS) | |
236 | buf[6] |= AX25_SSSID_SPARE; | |
237 | else | |
238 | buf[6] |= AX25_ESSID_SPARE; | |
239 | ||
240 | if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT; | |
241 | ||
242 | /* | |
243 | * Fast path the normal digiless path | |
244 | */ | |
245 | if (d == NULL || d->ndigi == 0) { | |
246 | buf[6] |= AX25_EBIT; | |
247 | return 2 * AX25_ADDR_LEN; | |
248 | } | |
249 | ||
250 | buf += AX25_ADDR_LEN; | |
251 | len += AX25_ADDR_LEN; | |
252 | ||
253 | while (ct < d->ndigi) { | |
254 | memcpy(buf, &d->calls[ct], AX25_ADDR_LEN); | |
255 | ||
256 | if (d->repeated[ct]) | |
257 | buf[6] |= AX25_HBIT; | |
258 | else | |
259 | buf[6] &= ~AX25_HBIT; | |
260 | ||
261 | buf[6] &= ~AX25_EBIT; | |
262 | buf[6] |= AX25_SSSID_SPARE; | |
263 | ||
264 | buf += AX25_ADDR_LEN; | |
265 | len += AX25_ADDR_LEN; | |
266 | ct++; | |
267 | } | |
268 | ||
269 | buf[-1] |= AX25_EBIT; | |
270 | ||
271 | return len; | |
272 | } | |
273 | ||
e8cc49bb | 274 | int ax25_addr_size(const ax25_digi *dp) |
1da177e4 LT |
275 | { |
276 | if (dp == NULL) | |
277 | return 2 * AX25_ADDR_LEN; | |
278 | ||
279 | return AX25_ADDR_LEN * (2 + dp->ndigi); | |
280 | } | |
281 | ||
282 | /* | |
283 | * Reverse Digipeat List. May not pass both parameters as same struct | |
284 | */ | |
e8cc49bb | 285 | void ax25_digi_invert(const ax25_digi *in, ax25_digi *out) |
1da177e4 LT |
286 | { |
287 | int ct; | |
288 | ||
289 | out->ndigi = in->ndigi; | |
290 | out->lastrepeat = in->ndigi - in->lastrepeat - 2; | |
291 | ||
292 | /* Invert the digipeaters */ | |
293 | for (ct = 0; ct < in->ndigi; ct++) { | |
294 | out->calls[ct] = in->calls[in->ndigi - ct - 1]; | |
295 | ||
296 | if (ct <= out->lastrepeat) { | |
297 | out->calls[ct].ax25_call[6] |= AX25_HBIT; | |
298 | out->repeated[ct] = 1; | |
299 | } else { | |
300 | out->calls[ct].ax25_call[6] &= ~AX25_HBIT; | |
301 | out->repeated[ct] = 0; | |
302 | } | |
303 | } | |
304 | } | |
305 |