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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>
14#include <linux/module.h>
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>
25#include <linux/fcntl.h>
26#include <linux/mm.h>
27#include <linux/interrupt.h>
28
29/*
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.
33 */
34
35const ax25_address ax25_bcast =
36 {{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
37const ax25_address ax25_defaddr =
38 {{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
39const ax25_address null_ax25_address =
40 {{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
41
42EXPORT_SYMBOL_GPL(ax25_bcast);
43EXPORT_SYMBOL_GPL(ax25_defaddr);
44EXPORT_SYMBOL(null_ax25_address);
45
46/*
47 * ax25 -> ascii conversion
48 */
49char *ax2asc(char *buf, const ax25_address *a)
50{
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
77EXPORT_SYMBOL(ax2asc);
78
79/*
80 * ascii -> ax25 conversion
81 */
82void asc2ax(ax25_address *addr, const char *callsign)
83{
84 const char *s;
85 int n;
86
87 for (s = callsign, n = 0; n < 6; n++) {
88 if (*s != '\0' && *s != '-')
89 addr->ax25_call[n] = *s++;
90 else
91 addr->ax25_call[n] = ' ';
92 addr->ax25_call[n] <<= 1;
93 addr->ax25_call[n] &= 0xFE;
94 }
95
96 if (*s++ == '\0') {
97 addr->ax25_call[6] = 0x00;
98 return;
99 }
100
101 addr->ax25_call[6] = *s++ - '0';
102
103 if (*s != '\0') {
104 addr->ax25_call[6] *= 10;
105 addr->ax25_call[6] += *s++ - '0';
106 }
107
108 addr->ax25_call[6] <<= 1;
109 addr->ax25_call[6] &= 0x1E;
110}
111
112EXPORT_SYMBOL(asc2ax);
113
114/*
115 * Compare two ax.25 addresses
116 */
117int ax25cmp(const ax25_address *a, const ax25_address *b)
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
127 if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
128 return 0;
129
130 return 2; /* Partial match */
131}
132
133EXPORT_SYMBOL(ax25cmp);
134
135/*
136 * Compare two AX.25 digipeater paths.
137 */
138int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
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 */
159const 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)
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)
193 return NULL;
194 if (len < AX25_ADDR_LEN)
195 return NULL;
196
197 memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
198 digi->ndigi = d + 1;
199
200 if (buf[6] & AX25_HBIT) {
201 digi->repeated[d] = 1;
202 digi->lastrepeat = d;
203 } else {
204 digi->repeated[d] = 0;
205 }
206
207 buf += AX25_ADDR_LEN;
208 len -= AX25_ADDR_LEN;
209 d++;
210 }
211
212 return buf;
213}
214
215/*
216 * Assemble an AX.25 header from the bits
217 */
218int ax25_addr_build(unsigned char *buf, const ax25_address *src,
219 const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
220{
221 int len = 0;
222 int ct = 0;
223
224 memcpy(buf, dest, AX25_ADDR_LEN);
225 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
226 buf[6] |= AX25_SSSID_SPARE;
227
228 if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
229
230 buf += AX25_ADDR_LEN;
231 len += AX25_ADDR_LEN;
232
233 memcpy(buf, src, AX25_ADDR_LEN);
234 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
235 buf[6] &= ~AX25_SSSID_SPARE;
236
237 if (modulus == AX25_MODULUS)
238 buf[6] |= AX25_SSSID_SPARE;
239 else
240 buf[6] |= AX25_ESSID_SPARE;
241
242 if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
243
244 /*
245 * Fast path the normal digiless path
246 */
247 if (d == NULL || d->ndigi == 0) {
248 buf[6] |= AX25_EBIT;
249 return 2 * AX25_ADDR_LEN;
250 }
251
252 buf += AX25_ADDR_LEN;
253 len += AX25_ADDR_LEN;
254
255 while (ct < d->ndigi) {
256 memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
257
258 if (d->repeated[ct])
259 buf[6] |= AX25_HBIT;
260 else
261 buf[6] &= ~AX25_HBIT;
262
263 buf[6] &= ~AX25_EBIT;
264 buf[6] |= AX25_SSSID_SPARE;
265
266 buf += AX25_ADDR_LEN;
267 len += AX25_ADDR_LEN;
268 ct++;
269 }
270
271 buf[-1] |= AX25_EBIT;
272
273 return len;
274}
275
276int ax25_addr_size(const ax25_digi *dp)
277{
278 if (dp == NULL)
279 return 2 * AX25_ADDR_LEN;
280
281 return AX25_ADDR_LEN * (2 + dp->ndigi);
282}
283
284/*
285 * Reverse Digipeat List. May not pass both parameters as same struct
286 */
287void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
288{
289 int ct;
290
291 out->ndigi = in->ndigi;
292 out->lastrepeat = in->ndigi - in->lastrepeat - 2;
293
294 /* Invert the digipeaters */
295 for (ct = 0; ct < in->ndigi; ct++) {
296 out->calls[ct] = in->calls[in->ndigi - ct - 1];
297
298 if (ct <= out->lastrepeat) {
299 out->calls[ct].ax25_call[6] |= AX25_HBIT;
300 out->repeated[ct] = 1;
301 } else {
302 out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
303 out->repeated[ct] = 0;
304 }
305 }
306}
307
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 */
6#include <linux/errno.h>
7#include <linux/types.h>
8#include <linux/socket.h>
9#include <linux/in.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/timer.h>
13#include <linux/string.h>
14#include <linux/sockios.h>
15#include <linux/net.h>
16#include <net/ax25.h>
17#include <linux/inet.h>
18#include <linux/netdevice.h>
19#include <linux/skbuff.h>
20#include <net/sock.h>
21#include <linux/uaccess.h>
22#include <linux/fcntl.h>
23#include <linux/mm.h>
24#include <linux/interrupt.h>
25
26/*
27 * The default broadcast address of an interface is QST-0; the default address
28 * is LINUX-1. The null address is defined as a callsign of all spaces with
29 * an SSID of zero.
30 */
31
32const ax25_address ax25_bcast =
33 {{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
34const ax25_address ax25_defaddr =
35 {{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
36const ax25_address null_ax25_address =
37 {{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
38
39EXPORT_SYMBOL_GPL(ax25_bcast);
40EXPORT_SYMBOL_GPL(ax25_defaddr);
41EXPORT_SYMBOL(null_ax25_address);
42
43/*
44 * ax25 -> ascii conversion
45 */
46char *ax2asc(char *buf, const ax25_address *a)
47{
48 char c, *s;
49 int n;
50
51 for (n = 0, s = buf; n < 6; n++) {
52 c = (a->ax25_call[n] >> 1) & 0x7F;
53
54 if (c != ' ') *s++ = c;
55 }
56
57 *s++ = '-';
58
59 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
60 *s++ = '1';
61 n -= 10;
62 }
63
64 *s++ = n + '0';
65 *s++ = '\0';
66
67 if (*buf == '\0' || *buf == '-')
68 return "*";
69
70 return buf;
71
72}
73
74EXPORT_SYMBOL(ax2asc);
75
76/*
77 * ascii -> ax25 conversion
78 */
79void asc2ax(ax25_address *addr, const char *callsign)
80{
81 const char *s;
82 int n;
83
84 for (s = callsign, n = 0; n < 6; n++) {
85 if (*s != '\0' && *s != '-')
86 addr->ax25_call[n] = *s++;
87 else
88 addr->ax25_call[n] = ' ';
89 addr->ax25_call[n] <<= 1;
90 addr->ax25_call[n] &= 0xFE;
91 }
92
93 if (*s++ == '\0') {
94 addr->ax25_call[6] = 0x00;
95 return;
96 }
97
98 addr->ax25_call[6] = *s++ - '0';
99
100 if (*s != '\0') {
101 addr->ax25_call[6] *= 10;
102 addr->ax25_call[6] += *s++ - '0';
103 }
104
105 addr->ax25_call[6] <<= 1;
106 addr->ax25_call[6] &= 0x1E;
107}
108
109EXPORT_SYMBOL(asc2ax);
110
111/*
112 * Compare two ax.25 addresses
113 */
114int ax25cmp(const ax25_address *a, const ax25_address *b)
115{
116 int ct = 0;
117
118 while (ct < 6) {
119 if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
120 return 1;
121 ct++;
122 }
123
124 if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
125 return 0;
126
127 return 2; /* Partial match */
128}
129
130EXPORT_SYMBOL(ax25cmp);
131
132/*
133 * Compare two AX.25 digipeater paths.
134 */
135int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
136{
137 int i;
138
139 if (digi1->ndigi != digi2->ndigi)
140 return 1;
141
142 if (digi1->lastrepeat != digi2->lastrepeat)
143 return 1;
144
145 for (i = 0; i < digi1->ndigi; i++)
146 if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
147 return 1;
148
149 return 0;
150}
151
152/*
153 * Given an AX.25 address pull of to, from, digi list, command/response and the start of data
154 *
155 */
156const unsigned char *ax25_addr_parse(const unsigned char *buf, int len,
157 ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags,
158 int *dama)
159{
160 int d = 0;
161
162 if (len < 14) return NULL;
163
164 if (flags != NULL) {
165 *flags = 0;
166
167 if (buf[6] & AX25_CBIT)
168 *flags = AX25_COMMAND;
169 if (buf[13] & AX25_CBIT)
170 *flags = AX25_RESPONSE;
171 }
172
173 if (dama != NULL)
174 *dama = ~buf[13] & AX25_DAMA_FLAG;
175
176 /* Copy to, from */
177 if (dest != NULL)
178 memcpy(dest, buf + 0, AX25_ADDR_LEN);
179 if (src != NULL)
180 memcpy(src, buf + 7, AX25_ADDR_LEN);
181
182 buf += 2 * AX25_ADDR_LEN;
183 len -= 2 * AX25_ADDR_LEN;
184
185 digi->lastrepeat = -1;
186 digi->ndigi = 0;
187
188 while (!(buf[-1] & AX25_EBIT)) {
189 if (d >= AX25_MAX_DIGIS)
190 return NULL;
191 if (len < AX25_ADDR_LEN)
192 return NULL;
193
194 memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
195 digi->ndigi = d + 1;
196
197 if (buf[6] & AX25_HBIT) {
198 digi->repeated[d] = 1;
199 digi->lastrepeat = d;
200 } else {
201 digi->repeated[d] = 0;
202 }
203
204 buf += AX25_ADDR_LEN;
205 len -= AX25_ADDR_LEN;
206 d++;
207 }
208
209 return buf;
210}
211
212/*
213 * Assemble an AX.25 header from the bits
214 */
215int ax25_addr_build(unsigned char *buf, const ax25_address *src,
216 const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
217{
218 int len = 0;
219 int ct = 0;
220
221 memcpy(buf, dest, AX25_ADDR_LEN);
222 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
223 buf[6] |= AX25_SSSID_SPARE;
224
225 if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
226
227 buf += AX25_ADDR_LEN;
228 len += AX25_ADDR_LEN;
229
230 memcpy(buf, src, AX25_ADDR_LEN);
231 buf[6] &= ~(AX25_EBIT | AX25_CBIT);
232 buf[6] &= ~AX25_SSSID_SPARE;
233
234 if (modulus == AX25_MODULUS)
235 buf[6] |= AX25_SSSID_SPARE;
236 else
237 buf[6] |= AX25_ESSID_SPARE;
238
239 if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
240
241 /*
242 * Fast path the normal digiless path
243 */
244 if (d == NULL || d->ndigi == 0) {
245 buf[6] |= AX25_EBIT;
246 return 2 * AX25_ADDR_LEN;
247 }
248
249 buf += AX25_ADDR_LEN;
250 len += AX25_ADDR_LEN;
251
252 while (ct < d->ndigi) {
253 memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
254
255 if (d->repeated[ct])
256 buf[6] |= AX25_HBIT;
257 else
258 buf[6] &= ~AX25_HBIT;
259
260 buf[6] &= ~AX25_EBIT;
261 buf[6] |= AX25_SSSID_SPARE;
262
263 buf += AX25_ADDR_LEN;
264 len += AX25_ADDR_LEN;
265 ct++;
266 }
267
268 buf[-1] |= AX25_EBIT;
269
270 return len;
271}
272
273int ax25_addr_size(const ax25_digi *dp)
274{
275 if (dp == NULL)
276 return 2 * AX25_ADDR_LEN;
277
278 return AX25_ADDR_LEN * (2 + dp->ndigi);
279}
280
281/*
282 * Reverse Digipeat List. May not pass both parameters as same struct
283 */
284void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
285{
286 int ct;
287
288 out->ndigi = in->ndigi;
289 out->lastrepeat = in->ndigi - in->lastrepeat - 2;
290
291 /* Invert the digipeaters */
292 for (ct = 0; ct < in->ndigi; ct++) {
293 out->calls[ct] = in->calls[in->ndigi - ct - 1];
294
295 if (ct <= out->lastrepeat) {
296 out->calls[ct].ax25_call[6] |= AX25_HBIT;
297 out->repeated[ct] = 1;
298 } else {
299 out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
300 out->repeated[ct] = 0;
301 }
302 }
303}