1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
5 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
6 * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
7 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
8 * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
9 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
10 */
11
12 #include <linux/capability.h>
13 #include <linux/errno.h>
14 #include <linux/types.h>
15 #include <linux/socket.h>
16 #include <linux/timer.h>
17 #include <linux/in.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/string.h>
21 #include <linux/sockios.h>
22 #include <linux/net.h>
23 #include <linux/slab.h>
24 #include <net/ax25.h>
25 #include <linux/inet.h>
26 #include <linux/netdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/skbuff.h>
29 #include <linux/spinlock.h>
30 #include <net/sock.h>
31 #include <linux/uaccess.h>
32 #include <linux/fcntl.h>
33 #include <linux/mm.h>
34 #include <linux/interrupt.h>
35 #include <linux/init.h>
36 #include <linux/seq_file.h>
37 #include <linux/export.h>
38
39 static ax25_route *ax25_route_list;
40 DEFINE_RWLOCK(ax25_route_lock);
41
42 void ax25_rt_device_down(struct net_device *dev)
43 {
44 ax25_route *s, *t, *ax25_rt;
45
46 write_lock_bh(&ax25_route_lock);
47 ax25_rt = ax25_route_list;
48 while (ax25_rt != NULL) {
49 s = ax25_rt;
50 ax25_rt = ax25_rt->next;
51
52 if (s->dev == dev) {
53 if (ax25_route_list == s) {
54 ax25_route_list = s->next;
55 kfree(s->digipeat);
56 kfree(s);
57 } else {
58 for (t = ax25_route_list; t != NULL; t = t->next) {
59 if (t->next == s) {
60 t->next = s->next;
61 kfree(s->digipeat);
62 kfree(s);
63 break;
64 }
65 }
66 }
67 }
68 }
69 write_unlock_bh(&ax25_route_lock);
70 }
71
72 static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
73 {
74 ax25_route *ax25_rt;
75 ax25_dev *ax25_dev;
76 int i;
77
78 if (route->digi_count > AX25_MAX_DIGIS)
79 return -EINVAL;
80
81 ax25_dev = ax25_addr_ax25dev(&route->port_addr);
82 if (!ax25_dev)
83 return -EINVAL;
84
85 write_lock_bh(&ax25_route_lock);
86
87 ax25_rt = ax25_route_list;
88 while (ax25_rt != NULL) {
89 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 &&
90 ax25_rt->dev == ax25_dev->dev) {
91 kfree(ax25_rt->digipeat);
92 ax25_rt->digipeat = NULL;
93 if (route->digi_count != 0) {
94 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
95 write_unlock_bh(&ax25_route_lock);
96 ax25_dev_put(ax25_dev);
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 ax25_dev_put(ax25_dev);
108 return 0;
109 }
110 ax25_rt = ax25_rt->next;
111 }
112
113 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
114 write_unlock_bh(&ax25_route_lock);
115 ax25_dev_put(ax25_dev);
116 return -ENOMEM;
117 }
118
119 ax25_rt->callsign = route->dest_addr;
120 ax25_rt->dev = ax25_dev->dev;
121 ax25_rt->digipeat = NULL;
122 ax25_rt->ip_mode = ' ';
123 if (route->digi_count != 0) {
124 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
125 write_unlock_bh(&ax25_route_lock);
126 kfree(ax25_rt);
127 ax25_dev_put(ax25_dev);
128 return -ENOMEM;
129 }
130 ax25_rt->digipeat->lastrepeat = -1;
131 ax25_rt->digipeat->ndigi = route->digi_count;
132 for (i = 0; i < route->digi_count; i++) {
133 ax25_rt->digipeat->repeated[i] = 0;
134 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
135 }
136 }
137 ax25_rt->next = ax25_route_list;
138 ax25_route_list = ax25_rt;
139 write_unlock_bh(&ax25_route_lock);
140 ax25_dev_put(ax25_dev);
141
142 return 0;
143 }
144
145 void __ax25_put_route(ax25_route *ax25_rt)
146 {
147 kfree(ax25_rt->digipeat);
148 kfree(ax25_rt);
149 }
150
151 static int ax25_rt_del(struct ax25_routes_struct *route)
152 {
153 ax25_route *s, *t, *ax25_rt;
154 ax25_dev *ax25_dev;
155
156 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
157 return -EINVAL;
158
159 write_lock_bh(&ax25_route_lock);
160
161 ax25_rt = ax25_route_list;
162 while (ax25_rt != NULL) {
163 s = ax25_rt;
164 ax25_rt = ax25_rt->next;
165 if (s->dev == ax25_dev->dev &&
166 ax25cmp(&route->dest_addr, &s->callsign) == 0) {
167 if (ax25_route_list == s) {
168 ax25_route_list = s->next;
169 __ax25_put_route(s);
170 } else {
171 for (t = ax25_route_list; t != NULL; t = t->next) {
172 if (t->next == s) {
173 t->next = s->next;
174 __ax25_put_route(s);
175 break;
176 }
177 }
178 }
179 }
180 }
181 write_unlock_bh(&ax25_route_lock);
182 ax25_dev_put(ax25_dev);
183
184 return 0;
185 }
186
187 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
188 {
189 ax25_route *ax25_rt;
190 ax25_dev *ax25_dev;
191 int err = 0;
192
193 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
194 return -EINVAL;
195
196 write_lock_bh(&ax25_route_lock);
197
198 ax25_rt = ax25_route_list;
199 while (ax25_rt != NULL) {
200 if (ax25_rt->dev == ax25_dev->dev &&
201 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
202 switch (rt_option->cmd) {
203 case AX25_SET_RT_IPMODE:
204 switch (rt_option->arg) {
205 case ' ':
206 case 'D':
207 case 'V':
208 ax25_rt->ip_mode = rt_option->arg;
209 break;
210 default:
211 err = -EINVAL;
212 goto out;
213 }
214 break;
215 default:
216 err = -EINVAL;
217 goto out;
218 }
219 }
220 ax25_rt = ax25_rt->next;
221 }
222
223 out:
224 write_unlock_bh(&ax25_route_lock);
225 ax25_dev_put(ax25_dev);
226 return err;
227 }
228
229 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
230 {
231 struct ax25_route_opt_struct rt_option;
232 struct ax25_routes_struct route;
233
234 switch (cmd) {
235 case SIOCADDRT:
236 if (copy_from_user(&route, arg, sizeof(route)))
237 return -EFAULT;
238 return ax25_rt_add(&route);
239
240 case SIOCDELRT:
241 if (copy_from_user(&route, arg, sizeof(route)))
242 return -EFAULT;
243 return ax25_rt_del(&route);
244
245 case SIOCAX25OPTRT:
246 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
247 return -EFAULT;
248 return ax25_rt_opt(&rt_option);
249
250 default:
251 return -EINVAL;
252 }
253 }
254
255 #ifdef CONFIG_PROC_FS
256
257 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
258 __acquires(ax25_route_lock)
259 {
260 struct ax25_route *ax25_rt;
261 int i = 1;
262
263 read_lock(&ax25_route_lock);
264 if (*pos == 0)
265 return SEQ_START_TOKEN;
266
267 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
268 if (i == *pos)
269 return ax25_rt;
270 ++i;
271 }
272
273 return NULL;
274 }
275
276 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
277 {
278 ++*pos;
279 return (v == SEQ_START_TOKEN) ? ax25_route_list :
280 ((struct ax25_route *) v)->next;
281 }
282
283 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
284 __releases(ax25_route_lock)
285 {
286 read_unlock(&ax25_route_lock);
287 }
288
289 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
290 {
291 char buf[11];
292
293 if (v == SEQ_START_TOKEN)
294 seq_puts(seq, "callsign dev mode digipeaters\n");
295 else {
296 struct ax25_route *ax25_rt = v;
297 const char *callsign;
298 int i;
299
300 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
301 callsign = "default";
302 else
303 callsign = ax2asc(buf, &ax25_rt->callsign);
304
305 seq_printf(seq, "%-9s %-4s",
306 callsign,
307 ax25_rt->dev ? ax25_rt->dev->name : "???");
308
309 switch (ax25_rt->ip_mode) {
310 case 'V':
311 seq_puts(seq, " vc");
312 break;
313 case 'D':
314 seq_puts(seq, " dg");
315 break;
316 default:
317 seq_puts(seq, " *");
318 break;
319 }
320
321 if (ax25_rt->digipeat != NULL)
322 for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
323 seq_printf(seq, " %s",
324 ax2asc(buf, &ax25_rt->digipeat->calls[i]));
325
326 seq_puts(seq, "\n");
327 }
328 return 0;
329 }
330
331 const struct seq_operations ax25_rt_seqops = {
332 .start = ax25_rt_seq_start,
333 .next = ax25_rt_seq_next,
334 .stop = ax25_rt_seq_stop,
335 .show = ax25_rt_seq_show,
336 };
337 #endif
338
339 /*
340 * Find AX.25 route
341 *
342 * Only routes with a reference count of zero can be destroyed.
343 * Must be called with ax25_route_lock read locked.
344 */
345 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
346 {
347 ax25_route *ax25_spe_rt = NULL;
348 ax25_route *ax25_def_rt = NULL;
349 ax25_route *ax25_rt;
350
351 /*
352 * Bind to the physical interface we heard them on, or the default
353 * route if none is found;
354 */
355 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
356 if (dev == NULL) {
357 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
358 ax25_spe_rt = ax25_rt;
359 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
360 ax25_def_rt = ax25_rt;
361 } else {
362 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
363 ax25_spe_rt = ax25_rt;
364 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
365 ax25_def_rt = ax25_rt;
366 }
367 }
368
369 ax25_rt = ax25_def_rt;
370 if (ax25_spe_rt != NULL)
371 ax25_rt = ax25_spe_rt;
372
373 return ax25_rt;
374 }
375
376 /*
377 * Adjust path: If you specify a default route and want to connect
378 * a target on the digipeater path but w/o having a special route
379 * set before, the path has to be truncated from your target on.
380 */
381 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
382 {
383 int k;
384
385 for (k = 0; k < digipeat->ndigi; k++) {
386 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
387 break;
388 }
389
390 digipeat->ndigi = k;
391 }
392
393
394 /*
395 * Find which interface to use.
396 */
397 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
398 {
399 ax25_uid_assoc *user;
400 ax25_route *ax25_rt;
401 int err = 0;
402
403 ax25_route_lock_use();
404 ax25_rt = ax25_get_route(addr, NULL);
405 if (!ax25_rt) {
406 ax25_route_lock_unuse();
407 return -EHOSTUNREACH;
408 }
409 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
410 err = -EHOSTUNREACH;
411 goto put;
412 }
413
414 user = ax25_findbyuid(current_euid());
415 if (user) {
416 ax25->source_addr = user->call;
417 ax25_uid_put(user);
418 } else {
419 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
420 err = -EPERM;
421 goto put;
422 }
423 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
424 }
425
426 if (ax25_rt->digipeat != NULL) {
427 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
428 GFP_ATOMIC);
429 if (ax25->digipeat == NULL) {
430 err = -ENOMEM;
431 goto put;
432 }
433 ax25_adjust_path(addr, ax25->digipeat);
434 }
435
436 if (ax25->sk != NULL) {
437 local_bh_disable();
438 bh_lock_sock(ax25->sk);
439 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
440 bh_unlock_sock(ax25->sk);
441 local_bh_enable();
442 }
443
444 put:
445 ax25_route_lock_unuse();
446 return err;
447 }
448
449 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
450 ax25_address *dest, ax25_digi *digi)
451 {
452 unsigned char *bp;
453 int len;
454
455 len = digi->ndigi * AX25_ADDR_LEN;
456
457 if (unlikely(skb_headroom(skb) < len)) {
458 skb = skb_expand_head(skb, len);
459 if (!skb) {
460 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
461 return NULL;
462 }
463 }
464
465 bp = skb_push(skb, len);
466
467 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
468
469 return skb;
470 }
471
472 /*
473 * Free all memory associated with routing structures.
474 */
475 void __exit ax25_rt_free(void)
476 {
477 ax25_route *s, *ax25_rt = ax25_route_list;
478
479 write_lock_bh(&ax25_route_lock);
480 while (ax25_rt != NULL) {
481 s = ax25_rt;
482 ax25_rt = ax25_rt->next;
483
484 kfree(s->digipeat);
485 kfree(s);
486 }
487 write_unlock_bh(&ax25_route_lock);
488 }
489
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