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
ax25_rt_device_down(struct net_device * dev)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
ax25_rt_add(struct ax25_routes_struct * route)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 refcount_set(&ax25_rt->refcount, 1);
120 ax25_rt->callsign = route->dest_addr;
121 ax25_rt->dev = ax25_dev->dev;
122 ax25_rt->digipeat = NULL;
123 ax25_rt->ip_mode = ' ';
124 if (route->digi_count != 0) {
125 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
126 write_unlock_bh(&ax25_route_lock);
127 kfree(ax25_rt);
128 ax25_dev_put(ax25_dev);
129 return -ENOMEM;
130 }
131 ax25_rt->digipeat->lastrepeat = -1;
132 ax25_rt->digipeat->ndigi = route->digi_count;
133 for (i = 0; i < route->digi_count; i++) {
134 ax25_rt->digipeat->repeated[i] = 0;
135 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
136 }
137 }
138 ax25_rt->next = ax25_route_list;
139 ax25_route_list = ax25_rt;
140 write_unlock_bh(&ax25_route_lock);
141 ax25_dev_put(ax25_dev);
142
143 return 0;
144 }
145
__ax25_put_route(ax25_route * ax25_rt)146 void __ax25_put_route(ax25_route *ax25_rt)
147 {
148 kfree(ax25_rt->digipeat);
149 kfree(ax25_rt);
150 }
151
ax25_rt_del(struct ax25_routes_struct * route)152 static int ax25_rt_del(struct ax25_routes_struct *route)
153 {
154 ax25_route *s, *t, *ax25_rt;
155 ax25_dev *ax25_dev;
156
157 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
158 return -EINVAL;
159
160 write_lock_bh(&ax25_route_lock);
161
162 ax25_rt = ax25_route_list;
163 while (ax25_rt != NULL) {
164 s = ax25_rt;
165 ax25_rt = ax25_rt->next;
166 if (s->dev == ax25_dev->dev &&
167 ax25cmp(&route->dest_addr, &s->callsign) == 0) {
168 if (ax25_route_list == s) {
169 ax25_route_list = s->next;
170 ax25_put_route(s);
171 } else {
172 for (t = ax25_route_list; t != NULL; t = t->next) {
173 if (t->next == s) {
174 t->next = s->next;
175 ax25_put_route(s);
176 break;
177 }
178 }
179 }
180 }
181 }
182 write_unlock_bh(&ax25_route_lock);
183 ax25_dev_put(ax25_dev);
184
185 return 0;
186 }
187
ax25_rt_opt(struct ax25_route_opt_struct * rt_option)188 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
189 {
190 ax25_route *ax25_rt;
191 ax25_dev *ax25_dev;
192 int err = 0;
193
194 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
195 return -EINVAL;
196
197 write_lock_bh(&ax25_route_lock);
198
199 ax25_rt = ax25_route_list;
200 while (ax25_rt != NULL) {
201 if (ax25_rt->dev == ax25_dev->dev &&
202 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
203 switch (rt_option->cmd) {
204 case AX25_SET_RT_IPMODE:
205 switch (rt_option->arg) {
206 case ' ':
207 case 'D':
208 case 'V':
209 ax25_rt->ip_mode = rt_option->arg;
210 break;
211 default:
212 err = -EINVAL;
213 goto out;
214 }
215 break;
216 default:
217 err = -EINVAL;
218 goto out;
219 }
220 }
221 ax25_rt = ax25_rt->next;
222 }
223
224 out:
225 write_unlock_bh(&ax25_route_lock);
226 ax25_dev_put(ax25_dev);
227 return err;
228 }
229
ax25_rt_ioctl(unsigned int cmd,void __user * arg)230 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
231 {
232 struct ax25_route_opt_struct rt_option;
233 struct ax25_routes_struct route;
234
235 switch (cmd) {
236 case SIOCADDRT:
237 if (copy_from_user(&route, arg, sizeof(route)))
238 return -EFAULT;
239 return ax25_rt_add(&route);
240
241 case SIOCDELRT:
242 if (copy_from_user(&route, arg, sizeof(route)))
243 return -EFAULT;
244 return ax25_rt_del(&route);
245
246 case SIOCAX25OPTRT:
247 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
248 return -EFAULT;
249 return ax25_rt_opt(&rt_option);
250
251 default:
252 return -EINVAL;
253 }
254 }
255
256 #ifdef CONFIG_PROC_FS
257
ax25_rt_seq_start(struct seq_file * seq,loff_t * pos)258 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
259 __acquires(ax25_route_lock)
260 {
261 struct ax25_route *ax25_rt;
262 int i = 1;
263
264 read_lock(&ax25_route_lock);
265 if (*pos == 0)
266 return SEQ_START_TOKEN;
267
268 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
269 if (i == *pos)
270 return ax25_rt;
271 ++i;
272 }
273
274 return NULL;
275 }
276
ax25_rt_seq_next(struct seq_file * seq,void * v,loff_t * pos)277 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
278 {
279 ++*pos;
280 return (v == SEQ_START_TOKEN) ? ax25_route_list :
281 ((struct ax25_route *) v)->next;
282 }
283
ax25_rt_seq_stop(struct seq_file * seq,void * v)284 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
285 __releases(ax25_route_lock)
286 {
287 read_unlock(&ax25_route_lock);
288 }
289
ax25_rt_seq_show(struct seq_file * seq,void * v)290 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
291 {
292 char buf[11];
293
294 if (v == SEQ_START_TOKEN)
295 seq_puts(seq, "callsign dev mode digipeaters\n");
296 else {
297 struct ax25_route *ax25_rt = v;
298 const char *callsign;
299 int i;
300
301 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
302 callsign = "default";
303 else
304 callsign = ax2asc(buf, &ax25_rt->callsign);
305
306 seq_printf(seq, "%-9s %-4s",
307 callsign,
308 ax25_rt->dev ? ax25_rt->dev->name : "???");
309
310 switch (ax25_rt->ip_mode) {
311 case 'V':
312 seq_puts(seq, " vc");
313 break;
314 case 'D':
315 seq_puts(seq, " dg");
316 break;
317 default:
318 seq_puts(seq, " *");
319 break;
320 }
321
322 if (ax25_rt->digipeat != NULL)
323 for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
324 seq_printf(seq, " %s",
325 ax2asc(buf, &ax25_rt->digipeat->calls[i]));
326
327 seq_puts(seq, "\n");
328 }
329 return 0;
330 }
331
332 const struct seq_operations ax25_rt_seqops = {
333 .start = ax25_rt_seq_start,
334 .next = ax25_rt_seq_next,
335 .stop = ax25_rt_seq_stop,
336 .show = ax25_rt_seq_show,
337 };
338 #endif
339
340 /*
341 * Find AX.25 route
342 *
343 * Only routes with a reference count of zero can be destroyed.
344 * Must be called with ax25_route_lock read locked.
345 */
ax25_get_route(ax25_address * addr,struct net_device * dev)346 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
347 {
348 ax25_route *ax25_spe_rt = NULL;
349 ax25_route *ax25_def_rt = NULL;
350 ax25_route *ax25_rt;
351
352 /*
353 * Bind to the physical interface we heard them on, or the default
354 * route if none is found;
355 */
356 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
357 if (dev == NULL) {
358 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
359 ax25_spe_rt = ax25_rt;
360 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
361 ax25_def_rt = ax25_rt;
362 } else {
363 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
364 ax25_spe_rt = ax25_rt;
365 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
366 ax25_def_rt = ax25_rt;
367 }
368 }
369
370 ax25_rt = ax25_def_rt;
371 if (ax25_spe_rt != NULL)
372 ax25_rt = ax25_spe_rt;
373
374 return ax25_rt;
375 }
376
377 /*
378 * Adjust path: If you specify a default route and want to connect
379 * a target on the digipeater path but w/o having a special route
380 * set before, the path has to be truncated from your target on.
381 */
ax25_adjust_path(ax25_address * addr,ax25_digi * digipeat)382 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
383 {
384 int k;
385
386 for (k = 0; k < digipeat->ndigi; k++) {
387 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
388 break;
389 }
390
391 digipeat->ndigi = k;
392 }
393
394
395 /*
396 * Find which interface to use.
397 */
ax25_rt_autobind(ax25_cb * ax25,ax25_address * addr)398 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
399 {
400 ax25_uid_assoc *user;
401 ax25_route *ax25_rt;
402 int err = 0;
403
404 ax25_route_lock_use();
405 ax25_rt = ax25_get_route(addr, NULL);
406 if (!ax25_rt) {
407 ax25_route_lock_unuse();
408 return -EHOSTUNREACH;
409 }
410 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
411 err = -EHOSTUNREACH;
412 goto put;
413 }
414
415 user = ax25_findbyuid(current_euid());
416 if (user) {
417 ax25->source_addr = user->call;
418 ax25_uid_put(user);
419 } else {
420 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
421 err = -EPERM;
422 goto put;
423 }
424 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
425 }
426
427 if (ax25_rt->digipeat != NULL) {
428 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
429 GFP_ATOMIC);
430 if (ax25->digipeat == NULL) {
431 err = -ENOMEM;
432 goto put;
433 }
434 ax25_adjust_path(addr, ax25->digipeat);
435 }
436
437 if (ax25->sk != NULL) {
438 local_bh_disable();
439 bh_lock_sock(ax25->sk);
440 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
441 bh_unlock_sock(ax25->sk);
442 local_bh_enable();
443 }
444
445 put:
446 ax25_route_lock_unuse();
447 return err;
448 }
449
ax25_rt_build_path(struct sk_buff * skb,ax25_address * src,ax25_address * dest,ax25_digi * digi)450 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
451 ax25_address *dest, ax25_digi *digi)
452 {
453 struct sk_buff *skbn;
454 unsigned char *bp;
455 int len;
456
457 len = digi->ndigi * AX25_ADDR_LEN;
458
459 if (skb_headroom(skb) < len) {
460 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
461 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
462 return NULL;
463 }
464
465 if (skb->sk != NULL)
466 skb_set_owner_w(skbn, skb->sk);
467
468 consume_skb(skb);
469
470 skb = skbn;
471 }
472
473 bp = skb_push(skb, len);
474
475 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
476
477 return skb;
478 }
479
480 /*
481 * Free all memory associated with routing structures.
482 */
ax25_rt_free(void)483 void __exit ax25_rt_free(void)
484 {
485 ax25_route *s, *ax25_rt = ax25_route_list;
486
487 write_lock_bh(&ax25_route_lock);
488 while (ax25_rt != NULL) {
489 s = ax25_rt;
490 ax25_rt = ax25_rt->next;
491
492 kfree(s->digipeat);
493 kfree(s);
494 }
495 write_unlock_bh(&ax25_route_lock);
496 }
497