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(objp: s->digipeat); |
56 | kfree(objp: 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(objp: s->digipeat); |
62 | kfree(objp: 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(objp: ax25_rt->digipeat); |
92 | ax25_rt->digipeat = NULL; |
93 | if (route->digi_count != 0) { |
94 | if ((ax25_rt->digipeat = kmalloc(size: 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(size: 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(size: sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { |
125 | write_unlock_bh(&ax25_route_lock); |
126 | kfree(objp: 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(objp: ax25_rt->digipeat); |
148 | kfree(objp: 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(ax25_rt: 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(ax25_rt: 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(to: &route, from: arg, n: sizeof(route))) |
237 | return -EFAULT; |
238 | return ax25_rt_add(route: &route); |
239 | |
240 | case SIOCDELRT: |
241 | if (copy_from_user(to: &route, from: arg, n: sizeof(route))) |
242 | return -EFAULT; |
243 | return ax25_rt_del(route: &route); |
244 | |
245 | case SIOCAX25OPTRT: |
246 | if (copy_from_user(to: &rt_option, from: arg, n: sizeof(rt_option))) |
247 | return -EFAULT; |
248 | return ax25_rt_opt(rt_option: &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(m: seq, s: "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(m: seq, fmt: "%-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(m: seq, s: " vc" ); |
312 | break; |
313 | case 'D': |
314 | seq_puts(m: seq, s: " dg" ); |
315 | break; |
316 | default: |
317 | seq_puts(m: seq, s: " *" ); |
318 | break; |
319 | } |
320 | |
321 | if (ax25_rt->digipeat != NULL) |
322 | for (i = 0; i < ax25_rt->digipeat->ndigi; i++) |
323 | seq_printf(m: seq, fmt: " %s" , |
324 | ax2asc(buf, &ax25_rt->digipeat->calls[i])); |
325 | |
326 | seq_puts(m: seq, s: "\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(dev: 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(assoc: 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(p: ax25_rt->digipeat, size: sizeof(ax25_digi), |
428 | GFP_ATOMIC); |
429 | if (ax25->digipeat == NULL) { |
430 | err = -ENOMEM; |
431 | goto put; |
432 | } |
433 | ax25_adjust_path(addr, digipeat: ax25->digipeat); |
434 | } |
435 | |
436 | if (ax25->sk != NULL) { |
437 | local_bh_disable(); |
438 | bh_lock_sock(ax25->sk); |
439 | sock_reset_flag(sk: ax25->sk, flag: 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, headroom: 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(objp: s->digipeat); |
485 | kfree(objp: s); |
486 | } |
487 | write_unlock_bh(&ax25_route_lock); |
488 | } |
489 | |