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 ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
79 return -EINVAL;
80 if (route->digi_count > AX25_MAX_DIGIS)
81 return -EINVAL;
82
83 write_lock_bh(&ax25_route_lock);
84
85 ax25_rt = ax25_route_list;
86 while (ax25_rt != NULL) {
87 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 &&
88 ax25_rt->dev == ax25_dev->dev) {
89 kfree(ax25_rt->digipeat);
90 ax25_rt->digipeat = NULL;
91 if (route->digi_count != 0) {
92 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
93 write_unlock_bh(&ax25_route_lock);
94 return -ENOMEM;
95 }
96 ax25_rt->digipeat->lastrepeat = -1;
97 ax25_rt->digipeat->ndigi = route->digi_count;
98 for (i = 0; i < route->digi_count; i++) {
99 ax25_rt->digipeat->repeated[i] = 0;
100 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
101 }
102 }
103 write_unlock_bh(&ax25_route_lock);
104 return 0;
105 }
106 ax25_rt = ax25_rt->next;
107 }
108
109 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
110 write_unlock_bh(&ax25_route_lock);
111 return -ENOMEM;
112 }
113
114 refcount_set(&ax25_rt->refcount, 1);
115 ax25_rt->callsign = route->dest_addr;
116 ax25_rt->dev = ax25_dev->dev;
117 ax25_rt->digipeat = NULL;
118 ax25_rt->ip_mode = ' ';
119 if (route->digi_count != 0) {
120 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
121 write_unlock_bh(&ax25_route_lock);
122 kfree(ax25_rt);
123 return -ENOMEM;
124 }
125 ax25_rt->digipeat->lastrepeat = -1;
126 ax25_rt->digipeat->ndigi = route->digi_count;
127 for (i = 0; i < route->digi_count; i++) {
128 ax25_rt->digipeat->repeated[i] = 0;
129 ax25_rt->digipeat->calls[i] = route->digi_addr[i];
130 }
131 }
132 ax25_rt->next = ax25_route_list;
133 ax25_route_list = ax25_rt;
134 write_unlock_bh(&ax25_route_lock);
135
136 return 0;
137 }
138
__ax25_put_route(ax25_route * ax25_rt)139 void __ax25_put_route(ax25_route *ax25_rt)
140 {
141 kfree(ax25_rt->digipeat);
142 kfree(ax25_rt);
143 }
144
ax25_rt_del(struct ax25_routes_struct * route)145 static int ax25_rt_del(struct ax25_routes_struct *route)
146 {
147 ax25_route *s, *t, *ax25_rt;
148 ax25_dev *ax25_dev;
149
150 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
151 return -EINVAL;
152
153 write_lock_bh(&ax25_route_lock);
154
155 ax25_rt = ax25_route_list;
156 while (ax25_rt != NULL) {
157 s = ax25_rt;
158 ax25_rt = ax25_rt->next;
159 if (s->dev == ax25_dev->dev &&
160 ax25cmp(&route->dest_addr, &s->callsign) == 0) {
161 if (ax25_route_list == s) {
162 ax25_route_list = s->next;
163 ax25_put_route(s);
164 } else {
165 for (t = ax25_route_list; t != NULL; t = t->next) {
166 if (t->next == s) {
167 t->next = s->next;
168 ax25_put_route(s);
169 break;
170 }
171 }
172 }
173 }
174 }
175 write_unlock_bh(&ax25_route_lock);
176
177 return 0;
178 }
179
ax25_rt_opt(struct ax25_route_opt_struct * rt_option)180 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
181 {
182 ax25_route *ax25_rt;
183 ax25_dev *ax25_dev;
184 int err = 0;
185
186 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
187 return -EINVAL;
188
189 write_lock_bh(&ax25_route_lock);
190
191 ax25_rt = ax25_route_list;
192 while (ax25_rt != NULL) {
193 if (ax25_rt->dev == ax25_dev->dev &&
194 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
195 switch (rt_option->cmd) {
196 case AX25_SET_RT_IPMODE:
197 switch (rt_option->arg) {
198 case ' ':
199 case 'D':
200 case 'V':
201 ax25_rt->ip_mode = rt_option->arg;
202 break;
203 default:
204 err = -EINVAL;
205 goto out;
206 }
207 break;
208 default:
209 err = -EINVAL;
210 goto out;
211 }
212 }
213 ax25_rt = ax25_rt->next;
214 }
215
216 out:
217 write_unlock_bh(&ax25_route_lock);
218 return err;
219 }
220
ax25_rt_ioctl(unsigned int cmd,void __user * arg)221 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
222 {
223 struct ax25_route_opt_struct rt_option;
224 struct ax25_routes_struct route;
225
226 switch (cmd) {
227 case SIOCADDRT:
228 if (copy_from_user(&route, arg, sizeof(route)))
229 return -EFAULT;
230 return ax25_rt_add(&route);
231
232 case SIOCDELRT:
233 if (copy_from_user(&route, arg, sizeof(route)))
234 return -EFAULT;
235 return ax25_rt_del(&route);
236
237 case SIOCAX25OPTRT:
238 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
239 return -EFAULT;
240 return ax25_rt_opt(&rt_option);
241
242 default:
243 return -EINVAL;
244 }
245 }
246
247 #ifdef CONFIG_PROC_FS
248
ax25_rt_seq_start(struct seq_file * seq,loff_t * pos)249 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
250 __acquires(ax25_route_lock)
251 {
252 struct ax25_route *ax25_rt;
253 int i = 1;
254
255 read_lock(&ax25_route_lock);
256 if (*pos == 0)
257 return SEQ_START_TOKEN;
258
259 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
260 if (i == *pos)
261 return ax25_rt;
262 ++i;
263 }
264
265 return NULL;
266 }
267
ax25_rt_seq_next(struct seq_file * seq,void * v,loff_t * pos)268 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
269 {
270 ++*pos;
271 return (v == SEQ_START_TOKEN) ? ax25_route_list :
272 ((struct ax25_route *) v)->next;
273 }
274
ax25_rt_seq_stop(struct seq_file * seq,void * v)275 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
276 __releases(ax25_route_lock)
277 {
278 read_unlock(&ax25_route_lock);
279 }
280
ax25_rt_seq_show(struct seq_file * seq,void * v)281 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
282 {
283 char buf[11];
284
285 if (v == SEQ_START_TOKEN)
286 seq_puts(seq, "callsign dev mode digipeaters\n");
287 else {
288 struct ax25_route *ax25_rt = v;
289 const char *callsign;
290 int i;
291
292 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
293 callsign = "default";
294 else
295 callsign = ax2asc(buf, &ax25_rt->callsign);
296
297 seq_printf(seq, "%-9s %-4s",
298 callsign,
299 ax25_rt->dev ? ax25_rt->dev->name : "???");
300
301 switch (ax25_rt->ip_mode) {
302 case 'V':
303 seq_puts(seq, " vc");
304 break;
305 case 'D':
306 seq_puts(seq, " dg");
307 break;
308 default:
309 seq_puts(seq, " *");
310 break;
311 }
312
313 if (ax25_rt->digipeat != NULL)
314 for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
315 seq_printf(seq, " %s",
316 ax2asc(buf, &ax25_rt->digipeat->calls[i]));
317
318 seq_puts(seq, "\n");
319 }
320 return 0;
321 }
322
323 const struct seq_operations ax25_rt_seqops = {
324 .start = ax25_rt_seq_start,
325 .next = ax25_rt_seq_next,
326 .stop = ax25_rt_seq_stop,
327 .show = ax25_rt_seq_show,
328 };
329 #endif
330
331 /*
332 * Find AX.25 route
333 *
334 * Only routes with a reference count of zero can be destroyed.
335 * Must be called with ax25_route_lock read locked.
336 */
ax25_get_route(ax25_address * addr,struct net_device * dev)337 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
338 {
339 ax25_route *ax25_spe_rt = NULL;
340 ax25_route *ax25_def_rt = NULL;
341 ax25_route *ax25_rt;
342
343 /*
344 * Bind to the physical interface we heard them on, or the default
345 * route if none is found;
346 */
347 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
348 if (dev == NULL) {
349 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
350 ax25_spe_rt = ax25_rt;
351 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
352 ax25_def_rt = ax25_rt;
353 } else {
354 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
355 ax25_spe_rt = ax25_rt;
356 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
357 ax25_def_rt = ax25_rt;
358 }
359 }
360
361 ax25_rt = ax25_def_rt;
362 if (ax25_spe_rt != NULL)
363 ax25_rt = ax25_spe_rt;
364
365 return ax25_rt;
366 }
367
368 /*
369 * Adjust path: If you specify a default route and want to connect
370 * a target on the digipeater path but w/o having a special route
371 * set before, the path has to be truncated from your target on.
372 */
ax25_adjust_path(ax25_address * addr,ax25_digi * digipeat)373 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
374 {
375 int k;
376
377 for (k = 0; k < digipeat->ndigi; k++) {
378 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
379 break;
380 }
381
382 digipeat->ndigi = k;
383 }
384
385
386 /*
387 * Find which interface to use.
388 */
ax25_rt_autobind(ax25_cb * ax25,ax25_address * addr)389 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
390 {
391 ax25_uid_assoc *user;
392 ax25_route *ax25_rt;
393 int err = 0;
394
395 ax25_route_lock_use();
396 ax25_rt = ax25_get_route(addr, NULL);
397 if (!ax25_rt) {
398 ax25_route_lock_unuse();
399 return -EHOSTUNREACH;
400 }
401 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
402 err = -EHOSTUNREACH;
403 goto put;
404 }
405
406 user = ax25_findbyuid(current_euid());
407 if (user) {
408 ax25->source_addr = user->call;
409 ax25_uid_put(user);
410 } else {
411 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
412 err = -EPERM;
413 goto put;
414 }
415 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
416 }
417
418 if (ax25_rt->digipeat != NULL) {
419 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
420 GFP_ATOMIC);
421 if (ax25->digipeat == NULL) {
422 err = -ENOMEM;
423 goto put;
424 }
425 ax25_adjust_path(addr, ax25->digipeat);
426 }
427
428 if (ax25->sk != NULL) {
429 local_bh_disable();
430 bh_lock_sock(ax25->sk);
431 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
432 bh_unlock_sock(ax25->sk);
433 local_bh_enable();
434 }
435
436 put:
437 ax25_route_lock_unuse();
438 return err;
439 }
440
ax25_rt_build_path(struct sk_buff * skb,ax25_address * src,ax25_address * dest,ax25_digi * digi)441 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
442 ax25_address *dest, ax25_digi *digi)
443 {
444 struct sk_buff *skbn;
445 unsigned char *bp;
446 int len;
447
448 len = digi->ndigi * AX25_ADDR_LEN;
449
450 if (skb_headroom(skb) < len) {
451 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
452 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
453 return NULL;
454 }
455
456 if (skb->sk != NULL)
457 skb_set_owner_w(skbn, skb->sk);
458
459 consume_skb(skb);
460
461 skb = skbn;
462 }
463
464 bp = skb_push(skb, len);
465
466 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
467
468 return skb;
469 }
470
471 /*
472 * Free all memory associated with routing structures.
473 */
ax25_rt_free(void)474 void __exit ax25_rt_free(void)
475 {
476 ax25_route *s, *ax25_rt = ax25_route_list;
477
478 write_lock_bh(&ax25_route_lock);
479 while (ax25_rt != NULL) {
480 s = ax25_rt;
481 ax25_rt = ax25_rt->next;
482
483 kfree(s->digipeat);
484 kfree(s);
485 }
486 write_unlock_bh(&ax25_route_lock);
487 }
488