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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Ralf Baechle70868ea2006-05-03 23:25:17 -070014#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/sched.h>
16#include <linux/timer.h>
17#include <linux/string.h>
18#include <linux/sockios.h>
19#include <linux/net.h>
20#include <net/ax25.h>
21#include <linux/inet.h>
22#include <linux/netdevice.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <asm/uaccess.h>
26#include <asm/system.h>
27#include <linux/fcntl.h>
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30
31/*
32 * The null address is defined as a callsign of all spaces with an
33 * SSID of zero.
34 */
35ax25_address null_ax25_address = {{0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x00}};
36
Ralf Baechle70868ea2006-05-03 23:25:17 -070037EXPORT_SYMBOL(null_ax25_address);
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039/*
40 * ax25 -> ascii conversion
41 */
Ralf Baechlef75268c2005-09-06 15:49:39 -070042char *ax2asc(char *buf, ax25_address *a)
Linus Torvalds1da177e2005-04-16 15:20:36 -070043{
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 char c, *s;
45 int n;
46
47 for (n = 0, s = buf; n < 6; n++) {
48 c = (a->ax25_call[n] >> 1) & 0x7F;
49
50 if (c != ' ') *s++ = c;
51 }
52
53 *s++ = '-';
54
55 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
56 *s++ = '1';
57 n -= 10;
58 }
59
60 *s++ = n + '0';
61 *s++ = '\0';
62
63 if (*buf == '\0' || *buf == '-')
64 return "*";
65
66 return buf;
67
68}
69
Ralf Baechle70868ea2006-05-03 23:25:17 -070070EXPORT_SYMBOL(ax2asc);
71
Linus Torvalds1da177e2005-04-16 15:20:36 -070072/*
73 * ascii -> ax25 conversion
74 */
Ralf Baechlebaed16a2005-09-08 13:40:41 -070075void asc2ax(ax25_address *addr, char *callsign)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 char *s;
78 int n;
79
80 for (s = callsign, n = 0; n < 6; n++) {
81 if (*s != '\0' && *s != '-')
Ralf Baechlebaed16a2005-09-08 13:40:41 -070082 addr->ax25_call[n] = *s++;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 else
Ralf Baechlebaed16a2005-09-08 13:40:41 -070084 addr->ax25_call[n] = ' ';
85 addr->ax25_call[n] <<= 1;
86 addr->ax25_call[n] &= 0xFE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 }
88
89 if (*s++ == '\0') {
Ralf Baechlebaed16a2005-09-08 13:40:41 -070090 addr->ax25_call[6] = 0x00;
91 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 }
93
Ralf Baechlebaed16a2005-09-08 13:40:41 -070094 addr->ax25_call[6] = *s++ - '0';
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 if (*s != '\0') {
Ralf Baechlebaed16a2005-09-08 13:40:41 -070097 addr->ax25_call[6] *= 10;
98 addr->ax25_call[6] += *s++ - '0';
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 }
100
Ralf Baechlebaed16a2005-09-08 13:40:41 -0700101 addr->ax25_call[6] <<= 1;
102 addr->ax25_call[6] &= 0x1E;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
Ralf Baechle70868ea2006-05-03 23:25:17 -0700105EXPORT_SYMBOL(asc2ax);
106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107/*
108 * Compare two ax.25 addresses
109 */
110int ax25cmp(ax25_address *a, ax25_address *b)
111{
112 int ct = 0;
113
114 while (ct < 6) {
115 if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
116 return 1;
117 ct++;
118 }
119
120 if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
121 return 0;
122
123 return 2; /* Partial match */
124}
125
Ralf Baechle70868ea2006-05-03 23:25:17 -0700126EXPORT_SYMBOL(ax25cmp);
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128/*
129 * Compare two AX.25 digipeater paths.
130 */
131int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
132{
133 int i;
134
135 if (digi1->ndigi != digi2->ndigi)
136 return 1;
137
138 if (digi1->lastrepeat != digi2->lastrepeat)
139 return 1;
140
141 for (i = 0; i < digi1->ndigi; i++)
142 if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
143 return 1;
144
145 return 0;
146}
147
148/*
149 * Given an AX.25 address pull of to, from, digi list, command/response and the start of data
150 *
151 */
152unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
153{
154 int d = 0;
155
156 if (len < 14) return NULL;
157
158 if (flags != NULL) {
159 *flags = 0;
160
161 if (buf[6] & AX25_CBIT)
162 *flags = AX25_COMMAND;
163 if (buf[13] & AX25_CBIT)
164 *flags = AX25_RESPONSE;
165 }
166
167 if (dama != NULL)
168 *dama = ~buf[13] & AX25_DAMA_FLAG;
169
170 /* Copy to, from */
171 if (dest != NULL)
172 memcpy(dest, buf + 0, AX25_ADDR_LEN);
173 if (src != NULL)
174 memcpy(src, buf + 7, AX25_ADDR_LEN);
175
176 buf += 2 * AX25_ADDR_LEN;
177 len -= 2 * AX25_ADDR_LEN;
178
179 digi->lastrepeat = -1;
180 digi->ndigi = 0;
181
182 while (!(buf[-1] & AX25_EBIT)) {
183 if (d >= AX25_MAX_DIGIS) return NULL; /* Max of 6 digis */
184 if (len < 7) return NULL; /* Short packet */
185
186 memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
187 digi->ndigi = d + 1;
188
189 if (buf[6] & AX25_HBIT) {
190 digi->repeated[d] = 1;
191 digi->lastrepeat = d;
192 } else {
193 digi->repeated[d] = 0;
194 }
195
196 buf += AX25_ADDR_LEN;
197 len -= AX25_ADDR_LEN;
198 d++;
199 }
200
201 return buf;
202}
203
204/*
205 * Assemble an AX.25 header from the bits
206 */
207int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
208{
209 int len = 0;
210 int ct = 0;
211
212 memcpy(buf, dest, AX25_ADDR_LEN);
213 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
214 buf[6] |= AX25_SSSID_SPARE;
215
216 if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
217
218 buf += AX25_ADDR_LEN;
219 len += AX25_ADDR_LEN;
220
221 memcpy(buf, src, AX25_ADDR_LEN);
222 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
223 buf[6] &= ~AX25_SSSID_SPARE;
224
225 if (modulus == AX25_MODULUS)
226 buf[6] |= AX25_SSSID_SPARE;
227 else
228 buf[6] |= AX25_ESSID_SPARE;
229
230 if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
231
232 /*
233 * Fast path the normal digiless path
234 */
235 if (d == NULL || d->ndigi == 0) {
236 buf[6] |= AX25_EBIT;
237 return 2 * AX25_ADDR_LEN;
238 }
239
240 buf += AX25_ADDR_LEN;
241 len += AX25_ADDR_LEN;
242
243 while (ct < d->ndigi) {
244 memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
245
246 if (d->repeated[ct])
247 buf[6] |= AX25_HBIT;
248 else
249 buf[6] &= ~AX25_HBIT;
250
251 buf[6] &= ~AX25_EBIT;
252 buf[6] |= AX25_SSSID_SPARE;
253
254 buf += AX25_ADDR_LEN;
255 len += AX25_ADDR_LEN;
256 ct++;
257 }
258
259 buf[-1] |= AX25_EBIT;
260
261 return len;
262}
263
264int ax25_addr_size(ax25_digi *dp)
265{
266 if (dp == NULL)
267 return 2 * AX25_ADDR_LEN;
268
269 return AX25_ADDR_LEN * (2 + dp->ndigi);
270}
271
272/*
273 * Reverse Digipeat List. May not pass both parameters as same struct
274 */
275void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
276{
277 int ct;
278
279 out->ndigi = in->ndigi;
280 out->lastrepeat = in->ndigi - in->lastrepeat - 2;
281
282 /* Invert the digipeaters */
283 for (ct = 0; ct < in->ndigi; ct++) {
284 out->calls[ct] = in->calls[in->ndigi - ct - 1];
285
286 if (ct <= out->lastrepeat) {
287 out->calls[ct].ax25_call[6] |= AX25_HBIT;
288 out->repeated[ct] = 1;
289 } else {
290 out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
291 out->repeated[ct] = 0;
292 }
293 }
294}
295