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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
8 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
9 * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
10 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
11 * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
12 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
13 */
14
15 #include <linux/capability.h>
16 #include <linux/errno.h>
17 #include <linux/types.h>
18 #include <linux/socket.h>
19 #include <linux/timer.h>
20 #include <linux/in.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/string.h>
24 #include <linux/sockios.h>
25 #include <linux/net.h>
26 #include <linux/slab.h>
27 #include <net/ax25.h>
28 #include <linux/inet.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/skbuff.h>
32 #include <linux/spinlock.h>
33 #include <net/sock.h>
34 #include <asm/uaccess.h>
35 #include <linux/fcntl.h>
36 #include <linux/mm.h>
37 #include <linux/interrupt.h>
38 #include <linux/init.h>
39 #include <linux/seq_file.h>
40 #include <linux/export.h>
41
42 static ax25_route *ax25_route_list;
43 static DEFINE_RWLOCK(ax25_route_lock);
44
ax25_rt_device_down(struct net_device * dev)45 void ax25_rt_device_down(struct net_device *dev)
46 {
47 ax25_route *s, *t, *ax25_rt;
48
49 write_lock_bh(&ax25_route_lock);
50 ax25_rt = ax25_route_list;
51 while (ax25_rt != NULL) {
52 s = ax25_rt;
53 ax25_rt = ax25_rt->next;
54
55 if (s->dev == dev) {
56 if (ax25_route_list == s) {
57 ax25_route_list = s->next;
58 kfree(s->digipeat);
59 kfree(s);
60 } else {
61 for (t = ax25_route_list; t != NULL; t = t->next) {
62 if (t->next == s) {
63 t->next = s->next;
64 kfree(s->digipeat);
65 kfree(s);
66 break;
67 }
68 }
69 }
70 }
71 }
72 write_unlock_bh(&ax25_route_lock);
73 }
74
ax25_rt_add(struct ax25_routes_struct * route)75 static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
76 {
77 ax25_route *ax25_rt;
78 ax25_dev *ax25_dev;
79 int i;
80
81 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
82 return -EINVAL;
83 if (route->digi_count > AX25_MAX_DIGIS)
84 return -EINVAL;
85
86 write_lock_bh(&ax25_route_lock);
87
88 ax25_rt = ax25_route_list;
89 while (ax25_rt != NULL) {
90 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 &&
91 ax25_rt->dev == ax25_dev->dev) {
92 kfree(ax25_rt->digipeat);
93 ax25_rt->digipeat = NULL;
94 if (route->digi_count != 0) {
95 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
96 write_unlock_bh(&ax25_route_lock);
97 return -ENOMEM;
98 }
99 ax25_rt->digipeat->lastrepeat = -1;
100 ax25_rt->digipeat->ndigi = route->digi_count;
101 for (i = 0; i < route->digi_count; i++) {
102 ax25_rt->digipeat->repeated[i] = 0;
103 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
104 }
105 }
106 write_unlock_bh(&ax25_route_lock);
107 return 0;
108 }
109 ax25_rt = ax25_rt->next;
110 }
111
112 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
113 write_unlock_bh(&ax25_route_lock);
114 return -ENOMEM;
115 }
116
117 atomic_set(&ax25_rt->refcount, 1);
118 ax25_rt->callsign = route->dest_addr;
119 ax25_rt->dev = ax25_dev->dev;
120 ax25_rt->digipeat = NULL;
121 ax25_rt->ip_mode = ' ';
122 if (route->digi_count != 0) {
123 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
124 write_unlock_bh(&ax25_route_lock);
125 kfree(ax25_rt);
126 return -ENOMEM;
127 }
128 ax25_rt->digipeat->lastrepeat = -1;
129 ax25_rt->digipeat->ndigi = route->digi_count;
130 for (i = 0; i < route->digi_count; i++) {
131 ax25_rt->digipeat->repeated[i] = 0;
132 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
133 }
134 }
135 ax25_rt->next = ax25_route_list;
136 ax25_route_list = ax25_rt;
137 write_unlock_bh(&ax25_route_lock);
138
139 return 0;
140 }
141
__ax25_put_route(ax25_route * ax25_rt)142 void __ax25_put_route(ax25_route *ax25_rt)
143 {
144 kfree(ax25_rt->digipeat);
145 kfree(ax25_rt);
146 }
147
ax25_rt_del(struct ax25_routes_struct * route)148 static int ax25_rt_del(struct ax25_routes_struct *route)
149 {
150 ax25_route *s, *t, *ax25_rt;
151 ax25_dev *ax25_dev;
152
153 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
154 return -EINVAL;
155
156 write_lock_bh(&ax25_route_lock);
157
158 ax25_rt = ax25_route_list;
159 while (ax25_rt != NULL) {
160 s = ax25_rt;
161 ax25_rt = ax25_rt->next;
162 if (s->dev == ax25_dev->dev &&
163 ax25cmp(&route->dest_addr, &s->callsign) == 0) {
164 if (ax25_route_list == s) {
165 ax25_route_list = s->next;
166 ax25_put_route(s);
167 } else {
168 for (t = ax25_route_list; t != NULL; t = t->next) {
169 if (t->next == s) {
170 t->next = s->next;
171 ax25_put_route(s);
172 break;
173 }
174 }
175 }
176 }
177 }
178 write_unlock_bh(&ax25_route_lock);
179
180 return 0;
181 }
182
ax25_rt_opt(struct ax25_route_opt_struct * rt_option)183 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
184 {
185 ax25_route *ax25_rt;
186 ax25_dev *ax25_dev;
187 int err = 0;
188
189 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
190 return -EINVAL;
191
192 write_lock_bh(&ax25_route_lock);
193
194 ax25_rt = ax25_route_list;
195 while (ax25_rt != NULL) {
196 if (ax25_rt->dev == ax25_dev->dev &&
197 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
198 switch (rt_option->cmd) {
199 case AX25_SET_RT_IPMODE:
200 switch (rt_option->arg) {
201 case ' ':
202 case 'D':
203 case 'V':
204 ax25_rt->ip_mode = rt_option->arg;
205 break;
206 default:
207 err = -EINVAL;
208 goto out;
209 }
210 break;
211 default:
212 err = -EINVAL;
213 goto out;
214 }
215 }
216 ax25_rt = ax25_rt->next;
217 }
218
219 out:
220 write_unlock_bh(&ax25_route_lock);
221 return err;
222 }
223
ax25_rt_ioctl(unsigned int cmd,void __user * arg)224 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
225 {
226 struct ax25_route_opt_struct rt_option;
227 struct ax25_routes_struct route;
228
229 switch (cmd) {
230 case SIOCADDRT:
231 if (copy_from_user(&route, arg, sizeof(route)))
232 return -EFAULT;
233 return ax25_rt_add(&route);
234
235 case SIOCDELRT:
236 if (copy_from_user(&route, arg, sizeof(route)))
237 return -EFAULT;
238 return ax25_rt_del(&route);
239
240 case SIOCAX25OPTRT:
241 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
242 return -EFAULT;
243 return ax25_rt_opt(&rt_option);
244
245 default:
246 return -EINVAL;
247 }
248 }
249
250 #ifdef CONFIG_PROC_FS
251
ax25_rt_seq_start(struct seq_file * seq,loff_t * pos)252 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
253 __acquires(ax25_route_lock)
254 {
255 struct ax25_route *ax25_rt;
256 int i = 1;
257
258 read_lock(&ax25_route_lock);
259 if (*pos == 0)
260 return SEQ_START_TOKEN;
261
262 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
263 if (i == *pos)
264 return ax25_rt;
265 ++i;
266 }
267
268 return NULL;
269 }
270
ax25_rt_seq_next(struct seq_file * seq,void * v,loff_t * pos)271 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
272 {
273 ++*pos;
274 return (v == SEQ_START_TOKEN) ? ax25_route_list :
275 ((struct ax25_route *) v)->next;
276 }
277
ax25_rt_seq_stop(struct seq_file * seq,void * v)278 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
279 __releases(ax25_route_lock)
280 {
281 read_unlock(&ax25_route_lock);
282 }
283
ax25_rt_seq_show(struct seq_file * seq,void * v)284 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
285 {
286 char buf[11];
287
288 if (v == SEQ_START_TOKEN)
289 seq_puts(seq, "callsign dev mode digipeaters\n");
290 else {
291 struct ax25_route *ax25_rt = v;
292 const char *callsign;
293 int i;
294
295 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
296 callsign = "default";
297 else
298 callsign = ax2asc(buf, &ax25_rt->callsign);
299
300 seq_printf(seq, "%-9s %-4s",
301 callsign,
302 ax25_rt->dev ? ax25_rt->dev->name : "???");
303
304 switch (ax25_rt->ip_mode) {
305 case 'V':
306 seq_puts(seq, " vc");
307 break;
308 case 'D':
309 seq_puts(seq, " dg");
310 break;
311 default:
312 seq_puts(seq, " *");
313 break;
314 }
315
316 if (ax25_rt->digipeat != NULL)
317 for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
318 seq_printf(seq, " %s",
319 ax2asc(buf, &ax25_rt->digipeat->calls[i]));
320
321 seq_puts(seq, "\n");
322 }
323 return 0;
324 }
325
326 static const struct seq_operations ax25_rt_seqops = {
327 .start = ax25_rt_seq_start,
328 .next = ax25_rt_seq_next,
329 .stop = ax25_rt_seq_stop,
330 .show = ax25_rt_seq_show,
331 };
332
ax25_rt_info_open(struct inode * inode,struct file * file)333 static int ax25_rt_info_open(struct inode *inode, struct file *file)
334 {
335 return seq_open(file, &ax25_rt_seqops);
336 }
337
338 const struct file_operations ax25_route_fops = {
339 .owner = THIS_MODULE,
340 .open = ax25_rt_info_open,
341 .read = seq_read,
342 .llseek = seq_lseek,
343 .release = seq_release,
344 };
345
346 #endif
347
348 /*
349 * Find AX.25 route
350 *
351 * Only routes with a reference count of zero can be destroyed.
352 */
ax25_get_route(ax25_address * addr,struct net_device * dev)353 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
354 {
355 ax25_route *ax25_spe_rt = NULL;
356 ax25_route *ax25_def_rt = NULL;
357 ax25_route *ax25_rt;
358
359 read_lock(&ax25_route_lock);
360 /*
361 * Bind to the physical interface we heard them on, or the default
362 * route if none is found;
363 */
364 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
365 if (dev == NULL) {
366 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
367 ax25_spe_rt = ax25_rt;
368 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
369 ax25_def_rt = ax25_rt;
370 } else {
371 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
372 ax25_spe_rt = ax25_rt;
373 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
374 ax25_def_rt = ax25_rt;
375 }
376 }
377
378 ax25_rt = ax25_def_rt;
379 if (ax25_spe_rt != NULL)
380 ax25_rt = ax25_spe_rt;
381
382 if (ax25_rt != NULL)
383 ax25_hold_route(ax25_rt);
384
385 read_unlock(&ax25_route_lock);
386
387 return ax25_rt;
388 }
389
390 /*
391 * Adjust path: If you specify a default route and want to connect
392 * a target on the digipeater path but w/o having a special route
393 * set before, the path has to be truncated from your target on.
394 */
ax25_adjust_path(ax25_address * addr,ax25_digi * digipeat)395 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
396 {
397 int k;
398
399 for (k = 0; k < digipeat->ndigi; k++) {
400 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
401 break;
402 }
403
404 digipeat->ndigi = k;
405 }
406
407
408 /*
409 * Find which interface to use.
410 */
ax25_rt_autobind(ax25_cb * ax25,ax25_address * addr)411 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
412 {
413 ax25_uid_assoc *user;
414 ax25_route *ax25_rt;
415 int err = 0;
416
417 if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL)
418 return -EHOSTUNREACH;
419
420 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
421 err = -EHOSTUNREACH;
422 goto put;
423 }
424
425 user = ax25_findbyuid(current_euid());
426 if (user) {
427 ax25->source_addr = user->call;
428 ax25_uid_put(user);
429 } else {
430 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
431 err = -EPERM;
432 goto put;
433 }
434 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
435 }
436
437 if (ax25_rt->digipeat != NULL) {
438 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
439 GFP_ATOMIC);
440 if (ax25->digipeat == NULL) {
441 err = -ENOMEM;
442 goto put;
443 }
444 ax25_adjust_path(addr, ax25->digipeat);
445 }
446
447 if (ax25->sk != NULL) {
448 bh_lock_sock(ax25->sk);
449 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
450 bh_unlock_sock(ax25->sk);
451 }
452
453 put:
454 ax25_put_route(ax25_rt);
455
456 return err;
457 }
458
ax25_rt_build_path(struct sk_buff * skb,ax25_address * src,ax25_address * dest,ax25_digi * digi)459 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
460 ax25_address *dest, ax25_digi *digi)
461 {
462 struct sk_buff *skbn;
463 unsigned char *bp;
464 int len;
465
466 len = digi->ndigi * AX25_ADDR_LEN;
467
468 if (skb_headroom(skb) < len) {
469 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
470 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
471 return NULL;
472 }
473
474 if (skb->sk != NULL)
475 skb_set_owner_w(skbn, skb->sk);
476
477 kfree_skb(skb);
478
479 skb = skbn;
480 }
481
482 bp = skb_push(skb, len);
483
484 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
485
486 return skb;
487 }
488
489 /*
490 * Free all memory associated with routing structures.
491 */
ax25_rt_free(void)492 void __exit ax25_rt_free(void)
493 {
494 ax25_route *s, *ax25_rt = ax25_route_list;
495
496 write_lock_bh(&ax25_route_lock);
497 while (ax25_rt != NULL) {
498 s = ax25_rt;
499 ax25_rt = ax25_rt->next;
500
501 kfree(s->digipeat);
502 kfree(s);
503 }
504 write_unlock_bh(&ax25_route_lock);
505 }
506