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