1 /*
2 * AX.25 release 037
3 *
4 * This code REQUIRES 2.1.15 or higher/ NET3.038
5 *
6 * This module:
7 * This module is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Other kernels modules in this kit are generally BSD derived. See the copyright headers.
13 *
14 *
15 * History
16 * AX.25 020 Jonathan(G4KLX) First go.
17 * AX.25 022 Jonathan(G4KLX) Added the actual meat to this - we now have a nice heard list.
18 * AX.25 025 Alan(GW4PTS) First cut at autobinding by route scan.
19 * AX.25 028b Jonathan(G4KLX) Extracted AX25 control block from the
20 * sock structure. Device removal now
21 * removes the heard structure.
22 * AX.25 029 Steven(GW7RRM) Added /proc information for uid/callsign mapping.
23 * Jonathan(G4KLX) Handling of IP mode in the routing list and /proc entry.
24 * AX.25 030 Jonathan(G4KLX) Added digi-peaters to routing table, and
25 * ioctls to manipulate them. Added port
26 * configuration.
27 * AX.25 031 Jonathan(G4KLX) Added concept of default route.
28 * Joerg(DL1BKE) ax25_rt_build_path() find digipeater list and device by
29 * destination call. Needed for IP routing via digipeater
30 * Jonathan(G4KLX) Added routing for IP datagram packets.
31 * Joerg(DL1BKE) Changed routing for IP datagram and VC to use a default
32 * route if available. Does not overwrite default routes
33 * on route-table overflow anymore.
34 * Joerg(DL1BKE) Fixed AX.25 routing of IP datagram and VC, new ioctl()
35 * "SIOCAX25OPTRT" to set IP mode and a 'permanent' flag
36 * on routes.
37 * AX.25 033 Jonathan(G4KLX) Remove auto-router.
38 * Joerg(DL1BKE) Moved BPQ Ethernet driver to separate device.
39 * AX.25 035 Frederic(F1OAT) Support for pseudo-digipeating.
40 * Jonathan(G4KLX) Support for packet forwarding.
41 * Arnaldo C. Melo s/suser/capable/
42 */
43
44 #include <linux/errno.h>
45 #include <linux/types.h>
46 #include <linux/socket.h>
47 #include <linux/in.h>
48 #include <linux/kernel.h>
49 #include <linux/sched.h>
50 #include <linux/timer.h>
51 #include <linux/string.h>
52 #include <linux/sockios.h>
53 #include <linux/net.h>
54 #include <net/ax25.h>
55 #include <linux/inet.h>
56 #include <linux/netdevice.h>
57 #include <linux/if_arp.h>
58 #include <linux/skbuff.h>
59 #include <net/sock.h>
60 #include <asm/uaccess.h>
61 #include <asm/system.h>
62 #include <linux/fcntl.h>
63 #include <linux/mm.h>
64 #include <linux/interrupt.h>
65 #include <linux/init.h>
66
67 static ax25_route *ax25_route_list;
68
69 static ax25_route *ax25_find_route(ax25_address *, struct net_device *);
70
71 /*
72 * small macro to drop non-digipeated digipeaters and reverse path
73 */
ax25_route_invert(ax25_digi * in,ax25_digi * out)74 static inline void ax25_route_invert(ax25_digi *in, ax25_digi *out)
75 {
76 int k;
77
78 for (k = 0; k < in->ndigi; k++)
79 if (!in->repeated[k])
80 break;
81
82 in->ndigi = k;
83
84 ax25_digi_invert(in, out);
85 }
86
ax25_rt_device_down(struct net_device * dev)87 void ax25_rt_device_down(struct net_device *dev)
88 {
89 ax25_route *s, *t, *ax25_rt = ax25_route_list;
90
91 while (ax25_rt != NULL) {
92 s = ax25_rt;
93 ax25_rt = ax25_rt->next;
94
95 if (s->dev == dev) {
96 if (ax25_route_list == s) {
97 ax25_route_list = s->next;
98 if (s->digipeat != NULL)
99 kfree(s->digipeat);
100 kfree(s);
101 } else {
102 for (t = ax25_route_list; t != NULL; t = t->next) {
103 if (t->next == s) {
104 t->next = s->next;
105 if (s->digipeat != NULL)
106 kfree(s->digipeat);
107 kfree(s);
108 break;
109 }
110 }
111 }
112 }
113 }
114 }
115
ax25_rt_ioctl(unsigned int cmd,void * arg)116 int ax25_rt_ioctl(unsigned int cmd, void *arg)
117 {
118 unsigned long flags;
119 ax25_route *s, *t, *ax25_rt;
120 struct ax25_routes_struct route;
121 struct ax25_route_opt_struct rt_option;
122 ax25_dev *ax25_dev;
123 int i;
124
125 switch (cmd) {
126 case SIOCADDRT:
127 if (copy_from_user(&route, arg, sizeof(route)))
128 return -EFAULT;
129 if ((ax25_dev = ax25_addr_ax25dev(&route.port_addr)) == NULL)
130 return -EINVAL;
131 if (route.digi_count > AX25_MAX_DIGIS)
132 return -EINVAL;
133 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
134 if (ax25cmp(&ax25_rt->callsign, &route.dest_addr) == 0 && ax25_rt->dev == ax25_dev->dev) {
135 if (ax25_rt->digipeat != NULL) {
136 kfree(ax25_rt->digipeat);
137 ax25_rt->digipeat = NULL;
138 }
139 if (route.digi_count != 0) {
140 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL)
141 return -ENOMEM;
142 ax25_rt->digipeat->lastrepeat = -1;
143 ax25_rt->digipeat->ndigi = route.digi_count;
144 for (i = 0; i < route.digi_count; i++) {
145 ax25_rt->digipeat->repeated[i] = 0;
146 ax25_rt->digipeat->calls[i] = route.digi_addr[i];
147 }
148 }
149 return 0;
150 }
151 }
152 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL)
153 return -ENOMEM;
154 ax25_rt->callsign = route.dest_addr;
155 ax25_rt->dev = ax25_dev->dev;
156 ax25_rt->digipeat = NULL;
157 ax25_rt->ip_mode = ' ';
158 if (route.digi_count != 0) {
159 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
160 kfree(ax25_rt);
161 return -ENOMEM;
162 }
163 ax25_rt->digipeat->lastrepeat = -1;
164 ax25_rt->digipeat->ndigi = route.digi_count;
165 for (i = 0; i < route.digi_count; i++) {
166 ax25_rt->digipeat->repeated[i] = 0;
167 ax25_rt->digipeat->calls[i] = route.digi_addr[i];
168 }
169 }
170 save_flags(flags); cli();
171 ax25_rt->next = ax25_route_list;
172 ax25_route_list = ax25_rt;
173 restore_flags(flags);
174 break;
175
176 case SIOCDELRT:
177 if (copy_from_user(&route, arg, sizeof(route)))
178 return -EFAULT;
179 if ((ax25_dev = ax25_addr_ax25dev(&route.port_addr)) == NULL)
180 return -EINVAL;
181 ax25_rt = ax25_route_list;
182 while (ax25_rt != NULL) {
183 s = ax25_rt;
184 ax25_rt = ax25_rt->next;
185 if (s->dev == ax25_dev->dev && ax25cmp(&route.dest_addr, &s->callsign) == 0) {
186 if (ax25_route_list == s) {
187 ax25_route_list = s->next;
188 if (s->digipeat != NULL)
189 kfree(s->digipeat);
190 kfree(s);
191 } else {
192 for (t = ax25_route_list; t != NULL; t = t->next) {
193 if (t->next == s) {
194 t->next = s->next;
195 if (s->digipeat != NULL)
196 kfree(s->digipeat);
197 kfree(s);
198 break;
199 }
200 }
201 }
202 }
203 }
204 break;
205
206 case SIOCAX25OPTRT:
207 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
208 return -EFAULT;
209 if ((ax25_dev = ax25_addr_ax25dev(&rt_option.port_addr)) == NULL)
210 return -EINVAL;
211 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
212 if (ax25_rt->dev == ax25_dev->dev && ax25cmp(&rt_option.dest_addr, &ax25_rt->callsign) == 0) {
213 switch (rt_option.cmd) {
214 case AX25_SET_RT_IPMODE:
215 switch (rt_option.arg) {
216 case ' ':
217 case 'D':
218 case 'V':
219 ax25_rt->ip_mode = rt_option.arg;
220 break;
221 default:
222 return -EINVAL;
223 }
224 break;
225 default:
226 return -EINVAL;
227 }
228 }
229 }
230 break;
231
232 default:
233 return -EINVAL;
234 }
235
236 return 0;
237 }
238
ax25_rt_get_info(char * buffer,char ** start,off_t offset,int length)239 int ax25_rt_get_info(char *buffer, char **start, off_t offset, int length)
240 {
241 ax25_route *ax25_rt;
242 int len = 0;
243 off_t pos = 0;
244 off_t begin = 0;
245 char *callsign;
246 int i;
247
248 cli();
249
250 len += sprintf(buffer, "callsign dev mode digipeaters\n");
251
252 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
253 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
254 callsign = "default";
255 else
256 callsign = ax2asc(&ax25_rt->callsign);
257 len += sprintf(buffer + len, "%-9s %-4s",
258 callsign,
259 ax25_rt->dev ? ax25_rt->dev->name : "???");
260
261 switch (ax25_rt->ip_mode) {
262 case 'V':
263 len += sprintf(buffer + len, " vc");
264 break;
265 case 'D':
266 len += sprintf(buffer + len, " dg");
267 break;
268 default:
269 len += sprintf(buffer + len, " *");
270 break;
271 }
272
273 if (ax25_rt->digipeat != NULL)
274 for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
275 len += sprintf(buffer + len, " %s", ax2asc(&ax25_rt->digipeat->calls[i]));
276
277 len += sprintf(buffer + len, "\n");
278
279 pos = begin + len;
280
281 if (pos < offset) {
282 len = 0;
283 begin = pos;
284 }
285
286 if (pos > offset + length)
287 break;
288 }
289
290 sti();
291
292 *start = buffer + (offset - begin);
293 len -= (offset - begin);
294
295 if (len > length) len = length;
296
297 return len;
298 }
299
300 /*
301 * Find AX.25 route
302 */
ax25_find_route(ax25_address * addr,struct net_device * dev)303 static ax25_route *ax25_find_route(ax25_address *addr, struct net_device *dev)
304 {
305 ax25_route *ax25_spe_rt = NULL;
306 ax25_route *ax25_def_rt = NULL;
307 ax25_route *ax25_rt;
308
309 /*
310 * Bind to the physical interface we heard them on, or the default
311 * route if none is found;
312 */
313 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
314 if (dev == NULL) {
315 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
316 ax25_spe_rt = ax25_rt;
317 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
318 ax25_def_rt = ax25_rt;
319 } else {
320 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
321 ax25_spe_rt = ax25_rt;
322 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
323 ax25_def_rt = ax25_rt;
324 }
325 }
326
327 if (ax25_spe_rt != NULL)
328 return ax25_spe_rt;
329
330 return ax25_def_rt;
331 }
332
333 /*
334 * Adjust path: If you specify a default route and want to connect
335 * a target on the digipeater path but w/o having a special route
336 * set before, the path has to be truncated from your target on.
337 */
ax25_adjust_path(ax25_address * addr,ax25_digi * digipeat)338 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
339 {
340 int k;
341
342 for (k = 0; k < digipeat->ndigi; k++) {
343 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
344 break;
345 }
346
347 digipeat->ndigi = k;
348 }
349
350
351 /*
352 * Find which interface to use.
353 */
ax25_rt_autobind(ax25_cb * ax25,ax25_address * addr)354 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
355 {
356 ax25_route *ax25_rt;
357 ax25_address *call;
358
359 if ((ax25_rt = ax25_find_route(addr, NULL)) == NULL)
360 return -EHOSTUNREACH;
361
362 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL)
363 return -EHOSTUNREACH;
364
365 if ((call = ax25_findbyuid(current->euid)) == NULL) {
366 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE))
367 return -EPERM;
368 call = (ax25_address *)ax25->ax25_dev->dev->dev_addr;
369 }
370
371 ax25->source_addr = *call;
372
373 if (ax25_rt->digipeat != NULL) {
374 if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL)
375 return -ENOMEM;
376 memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi));
377 ax25_adjust_path(addr, ax25->digipeat);
378 }
379
380 if (ax25->sk != NULL)
381 ax25->sk->zapped = 0;
382
383 return 0;
384 }
385
386 /*
387 * dl1bke 960117: build digipeater path
388 * dl1bke 960301: use the default route if it exists
389 */
ax25_rt_find_route(ax25_address * addr,struct net_device * dev)390 ax25_route *ax25_rt_find_route(ax25_address *addr, struct net_device *dev)
391 {
392 static ax25_route route;
393 ax25_route *ax25_rt;
394
395 if ((ax25_rt = ax25_find_route(addr, dev)) == NULL) {
396 route.next = NULL;
397 route.callsign = *addr;
398 route.dev = dev;
399 route.digipeat = NULL;
400 route.ip_mode = ' ';
401 return &route;
402 }
403
404 return ax25_rt;
405 }
406
ax25_rt_build_path(struct sk_buff * skb,ax25_address * src,ax25_address * dest,ax25_digi * digi)407 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, ax25_address *dest, ax25_digi *digi)
408 {
409 struct sk_buff *skbn;
410 unsigned char *bp;
411 int len;
412
413 len = digi->ndigi * AX25_ADDR_LEN;
414
415 if (skb_headroom(skb) < len) {
416 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
417 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
418 return NULL;
419 }
420
421 if (skb->sk != NULL)
422 skb_set_owner_w(skbn, skb->sk);
423
424 kfree_skb(skb);
425
426 skb = skbn;
427 }
428
429 bp = skb_push(skb, len);
430
431 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
432
433 return skb;
434 }
435
436 /*
437 * Free all memory associated with routing structures.
438 */
ax25_rt_free(void)439 void __exit ax25_rt_free(void)
440 {
441 ax25_route *s, *ax25_rt = ax25_route_list;
442
443 while (ax25_rt != NULL) {
444 s = ax25_rt;
445 ax25_rt = ax25_rt->next;
446
447 if (s->digipeat != NULL)
448 kfree(s->digipeat);
449
450 kfree(s);
451 }
452 }
453