mm/memory-failure: send SIGBUS(BUS_MCEERR_AR) only to current thread
[linux-2.6-microblaze.git] / net / ax25 / ax25_route.c
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 ((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
139 void __ax25_put_route(ax25_route *ax25_rt)
140 {
141         kfree(ax25_rt->digipeat);
142         kfree(ax25_rt);
143 }
144
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
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
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
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
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
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
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  */
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  */
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  */
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
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  */
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 }