ipv6: updates to privacy addresses per RFC 4941
[linux-2.6.git] / net / ax25 / ax25_route.c
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
8  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
9  * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
10  * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
11  * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
12  * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
13  */
14
15 #include <linux/capability.h>
16 #include <linux/errno.h>
17 #include <linux/types.h>
18 #include <linux/socket.h>
19 #include <linux/timer.h>
20 #include <linux/in.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/string.h>
24 #include <linux/sockios.h>
25 #include <linux/net.h>
26 #include <linux/slab.h>
27 #include <net/ax25.h>
28 #include <linux/inet.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/skbuff.h>
32 #include <linux/spinlock.h>
33 #include <net/sock.h>
34 #include <asm/uaccess.h>
35 #include <asm/system.h>
36 #include <linux/fcntl.h>
37 #include <linux/mm.h>
38 #include <linux/interrupt.h>
39 #include <linux/init.h>
40 #include <linux/seq_file.h>
41
42 static ax25_route *ax25_route_list;
43 static DEFINE_RWLOCK(ax25_route_lock);
44
45 void ax25_rt_device_down(struct net_device *dev)
46 {
47         ax25_route *s, *t, *ax25_rt;
48
49         write_lock_bh(&ax25_route_lock);
50         ax25_rt = ax25_route_list;
51         while (ax25_rt != NULL) {
52                 s       = ax25_rt;
53                 ax25_rt = ax25_rt->next;
54
55                 if (s->dev == dev) {
56                         if (ax25_route_list == s) {
57                                 ax25_route_list = s->next;
58                                 kfree(s->digipeat);
59                                 kfree(s);
60                         } else {
61                                 for (t = ax25_route_list; t != NULL; t = t->next) {
62                                         if (t->next == s) {
63                                                 t->next = s->next;
64                                                 kfree(s->digipeat);
65                                                 kfree(s);
66                                                 break;
67                                         }
68                                 }
69                         }
70                 }
71         }
72         write_unlock_bh(&ax25_route_lock);
73 }
74
75 static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
76 {
77         ax25_route *ax25_rt;
78         ax25_dev *ax25_dev;
79         int i;
80
81         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
82                 return -EINVAL;
83         if (route->digi_count > AX25_MAX_DIGIS)
84                 return -EINVAL;
85
86         write_lock_bh(&ax25_route_lock);
87
88         ax25_rt = ax25_route_list;
89         while (ax25_rt != NULL) {
90                 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 &&
91                             ax25_rt->dev == ax25_dev->dev) {
92                         kfree(ax25_rt->digipeat);
93                         ax25_rt->digipeat = NULL;
94                         if (route->digi_count != 0) {
95                                 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
96                                         write_unlock_bh(&ax25_route_lock);
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                         return 0;
108                 }
109                 ax25_rt = ax25_rt->next;
110         }
111
112         if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
113                 write_unlock_bh(&ax25_route_lock);
114                 return -ENOMEM;
115         }
116
117         atomic_set(&ax25_rt->refcount, 1);
118         ax25_rt->callsign     = route->dest_addr;
119         ax25_rt->dev          = ax25_dev->dev;
120         ax25_rt->digipeat     = NULL;
121         ax25_rt->ip_mode      = ' ';
122         if (route->digi_count != 0) {
123                 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
124                         write_unlock_bh(&ax25_route_lock);
125                         kfree(ax25_rt);
126                         return -ENOMEM;
127                 }
128                 ax25_rt->digipeat->lastrepeat = -1;
129                 ax25_rt->digipeat->ndigi      = route->digi_count;
130                 for (i = 0; i < route->digi_count; i++) {
131                         ax25_rt->digipeat->repeated[i] = 0;
132                         ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
133                 }
134         }
135         ax25_rt->next   = ax25_route_list;
136         ax25_route_list = ax25_rt;
137         write_unlock_bh(&ax25_route_lock);
138
139         return 0;
140 }
141
142 void __ax25_put_route(ax25_route *ax25_rt)
143 {
144         kfree(ax25_rt->digipeat);
145         kfree(ax25_rt);
146 }
147
148 static int ax25_rt_del(struct ax25_routes_struct *route)
149 {
150         ax25_route *s, *t, *ax25_rt;
151         ax25_dev *ax25_dev;
152
153         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
154                 return -EINVAL;
155
156         write_lock_bh(&ax25_route_lock);
157
158         ax25_rt = ax25_route_list;
159         while (ax25_rt != NULL) {
160                 s       = ax25_rt;
161                 ax25_rt = ax25_rt->next;
162                 if (s->dev == ax25_dev->dev &&
163                     ax25cmp(&route->dest_addr, &s->callsign) == 0) {
164                         if (ax25_route_list == s) {
165                                 ax25_route_list = s->next;
166                                 ax25_put_route(s);
167                         } else {
168                                 for (t = ax25_route_list; t != NULL; t = t->next) {
169                                         if (t->next == s) {
170                                                 t->next = s->next;
171                                                 ax25_put_route(s);
172                                                 break;
173                                         }
174                                 }
175                         }
176                 }
177         }
178         write_unlock_bh(&ax25_route_lock);
179
180         return 0;
181 }
182
183 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
184 {
185         ax25_route *ax25_rt;
186         ax25_dev *ax25_dev;
187         int err = 0;
188
189         if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
190                 return -EINVAL;
191
192         write_lock_bh(&ax25_route_lock);
193
194         ax25_rt = ax25_route_list;
195         while (ax25_rt != NULL) {
196                 if (ax25_rt->dev == ax25_dev->dev &&
197                     ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
198                         switch (rt_option->cmd) {
199                         case AX25_SET_RT_IPMODE:
200                                 switch (rt_option->arg) {
201                                 case ' ':
202                                 case 'D':
203                                 case 'V':
204                                         ax25_rt->ip_mode = rt_option->arg;
205                                         break;
206                                 default:
207                                         err = -EINVAL;
208                                         goto out;
209                                 }
210                                 break;
211                         default:
212                                 err = -EINVAL;
213                                 goto out;
214                         }
215                 }
216                 ax25_rt = ax25_rt->next;
217         }
218
219 out:
220         write_unlock_bh(&ax25_route_lock);
221         return err;
222 }
223
224 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
225 {
226         struct ax25_route_opt_struct rt_option;
227         struct ax25_routes_struct route;
228
229         switch (cmd) {
230         case SIOCADDRT:
231                 if (copy_from_user(&route, arg, sizeof(route)))
232                         return -EFAULT;
233                 return ax25_rt_add(&route);
234
235         case SIOCDELRT:
236                 if (copy_from_user(&route, arg, sizeof(route)))
237                         return -EFAULT;
238                 return ax25_rt_del(&route);
239
240         case SIOCAX25OPTRT:
241                 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
242                         return -EFAULT;
243                 return ax25_rt_opt(&rt_option);
244
245         default:
246                 return -EINVAL;
247         }
248 }
249
250 #ifdef CONFIG_PROC_FS
251
252 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
253         __acquires(ax25_route_lock)
254 {
255         struct ax25_route *ax25_rt;
256         int i = 1;
257
258         read_lock(&ax25_route_lock);
259         if (*pos == 0)
260                 return SEQ_START_TOKEN;
261
262         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
263                 if (i == *pos)
264                         return ax25_rt;
265                 ++i;
266         }
267
268         return NULL;
269 }
270
271 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
272 {
273         ++*pos;
274         return (v == SEQ_START_TOKEN) ? ax25_route_list :
275                 ((struct ax25_route *) v)->next;
276 }
277
278 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
279         __releases(ax25_route_lock)
280 {
281         read_unlock(&ax25_route_lock);
282 }
283
284 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
285 {
286         char buf[11];
287
288         if (v == SEQ_START_TOKEN)
289                 seq_puts(seq, "callsign  dev  mode digipeaters\n");
290         else {
291                 struct ax25_route *ax25_rt = v;
292                 const char *callsign;
293                 int i;
294
295                 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
296                         callsign = "default";
297                 else
298                         callsign = ax2asc(buf, &ax25_rt->callsign);
299
300                 seq_printf(seq, "%-9s %-4s",
301                         callsign,
302                         ax25_rt->dev ? ax25_rt->dev->name : "???");
303
304                 switch (ax25_rt->ip_mode) {
305                 case 'V':
306                         seq_puts(seq, "   vc");
307                         break;
308                 case 'D':
309                         seq_puts(seq, "   dg");
310                         break;
311                 default:
312                         seq_puts(seq, "    *");
313                         break;
314                 }
315
316                 if (ax25_rt->digipeat != NULL)
317                         for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
318                                 seq_printf(seq, " %s",
319                                      ax2asc(buf, &ax25_rt->digipeat->calls[i]));
320
321                 seq_puts(seq, "\n");
322         }
323         return 0;
324 }
325
326 static const struct seq_operations ax25_rt_seqops = {
327         .start = ax25_rt_seq_start,
328         .next = ax25_rt_seq_next,
329         .stop = ax25_rt_seq_stop,
330         .show = ax25_rt_seq_show,
331 };
332
333 static int ax25_rt_info_open(struct inode *inode, struct file *file)
334 {
335         return seq_open(file, &ax25_rt_seqops);
336 }
337
338 const struct file_operations ax25_route_fops = {
339         .owner = THIS_MODULE,
340         .open = ax25_rt_info_open,
341         .read = seq_read,
342         .llseek = seq_lseek,
343         .release = seq_release,
344 };
345
346 #endif
347
348 /*
349  *      Find AX.25 route
350  *
351  *      Only routes with a reference count of zero can be destroyed.
352  */
353 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
354 {
355         ax25_route *ax25_spe_rt = NULL;
356         ax25_route *ax25_def_rt = NULL;
357         ax25_route *ax25_rt;
358
359         read_lock(&ax25_route_lock);
360         /*
361          *      Bind to the physical interface we heard them on, or the default
362          *      route if none is found;
363          */
364         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
365                 if (dev == NULL) {
366                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
367                                 ax25_spe_rt = ax25_rt;
368                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
369                                 ax25_def_rt = ax25_rt;
370                 } else {
371                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
372                                 ax25_spe_rt = ax25_rt;
373                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
374                                 ax25_def_rt = ax25_rt;
375                 }
376         }
377
378         ax25_rt = ax25_def_rt;
379         if (ax25_spe_rt != NULL)
380                 ax25_rt = ax25_spe_rt;
381
382         if (ax25_rt != NULL)
383                 ax25_hold_route(ax25_rt);
384
385         read_unlock(&ax25_route_lock);
386
387         return ax25_rt;
388 }
389
390 /*
391  *      Adjust path: If you specify a default route and want to connect
392  *      a target on the digipeater path but w/o having a special route
393  *      set before, the path has to be truncated from your target on.
394  */
395 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
396 {
397         int k;
398
399         for (k = 0; k < digipeat->ndigi; k++) {
400                 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
401                         break;
402         }
403
404         digipeat->ndigi = k;
405 }
406
407
408 /*
409  *      Find which interface to use.
410  */
411 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
412 {
413         ax25_uid_assoc *user;
414         ax25_route *ax25_rt;
415         int err = 0;
416
417         if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL)
418                 return -EHOSTUNREACH;
419
420         if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
421                 err = -EHOSTUNREACH;
422                 goto put;
423         }
424
425         user = ax25_findbyuid(current_euid());
426         if (user) {
427                 ax25->source_addr = user->call;
428                 ax25_uid_put(user);
429         } else {
430                 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
431                         err = -EPERM;
432                         goto put;
433                 }
434                 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
435         }
436
437         if (ax25_rt->digipeat != NULL) {
438                 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
439                                          GFP_ATOMIC);
440                 if (ax25->digipeat == NULL) {
441                         err = -ENOMEM;
442                         goto put;
443                 }
444                 ax25_adjust_path(addr, ax25->digipeat);
445         }
446
447         if (ax25->sk != NULL) {
448                 bh_lock_sock(ax25->sk);
449                 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
450                 bh_unlock_sock(ax25->sk);
451         }
452
453 put:
454         ax25_put_route(ax25_rt);
455
456         return err;
457 }
458
459 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
460         ax25_address *dest, ax25_digi *digi)
461 {
462         struct sk_buff *skbn;
463         unsigned char *bp;
464         int len;
465
466         len = digi->ndigi * AX25_ADDR_LEN;
467
468         if (skb_headroom(skb) < len) {
469                 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
470                         printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
471                         return NULL;
472                 }
473
474                 if (skb->sk != NULL)
475                         skb_set_owner_w(skbn, skb->sk);
476
477                 kfree_skb(skb);
478
479                 skb = skbn;
480         }
481
482         bp = skb_push(skb, len);
483
484         ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
485
486         return skb;
487 }
488
489 /*
490  *      Free all memory associated with routing structures.
491  */
492 void __exit ax25_rt_free(void)
493 {
494         ax25_route *s, *ax25_rt = ax25_route_list;
495
496         write_lock_bh(&ax25_route_lock);
497         while (ax25_rt != NULL) {
498                 s       = ax25_rt;
499                 ax25_rt = ax25_rt->next;
500
501                 kfree(s->digipeat);
502                 kfree(s);
503         }
504         write_unlock_bh(&ax25_route_lock);
505 }