[NET]: kfree cleanup
[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 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/socket.h>
17 #include <linux/timer.h>
18 #include <linux/in.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/string.h>
22 #include <linux/sockios.h>
23 #include <linux/net.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 <asm/uaccess.h>
32 #include <asm/system.h>
33 #include <linux/fcntl.h>
34 #include <linux/mm.h>
35 #include <linux/interrupt.h>
36 #include <linux/init.h>
37 #include <linux/seq_file.h>
38
39 static ax25_route *ax25_route_list;
40 static DEFINE_RWLOCK(ax25_route_lock);
41
42 static ax25_route *ax25_get_route(ax25_address *, struct net_device *);
43
44 void ax25_rt_device_down(struct net_device *dev)
45 {
46         ax25_route *s, *t, *ax25_rt;
47
48         write_lock(&ax25_route_lock);
49         ax25_rt = ax25_route_list;
50         while (ax25_rt != NULL) {
51                 s       = ax25_rt;
52                 ax25_rt = ax25_rt->next;
53
54                 if (s->dev == dev) {
55                         if (ax25_route_list == s) {
56                                 ax25_route_list = s->next;
57                                 kfree(s->digipeat);
58                                 kfree(s);
59                         } else {
60                                 for (t = ax25_route_list; t != NULL; t = t->next) {
61                                         if (t->next == s) {
62                                                 t->next = s->next;
63                                                 kfree(s->digipeat);
64                                                 kfree(s);
65                                                 break;
66                                         }
67                                 }
68                         }
69                 }
70         }
71         write_unlock(&ax25_route_lock);
72 }
73
74 static int ax25_rt_add(struct ax25_routes_struct *route)
75 {
76         ax25_route *ax25_rt;
77         ax25_dev *ax25_dev;
78         int i;
79
80         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
81                 return -EINVAL;
82         if (route->digi_count > AX25_MAX_DIGIS)
83                 return -EINVAL;
84
85         write_lock(&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(&ax25_route_lock);
96                                         return -ENOMEM;
97                                 }
98                                 ax25_rt->digipeat->lastrepeat = -1;
99                                 ax25_rt->digipeat->ndigi      = route->digi_count;
100                                 for (i = 0; i < route->digi_count; i++) {
101                                         ax25_rt->digipeat->repeated[i] = 0;
102                                         ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
103                                 }
104                         }
105                         write_unlock(&ax25_route_lock);
106                         return 0;
107                 }
108                 ax25_rt = ax25_rt->next;
109         }
110
111         if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
112                 write_unlock(&ax25_route_lock);
113                 return -ENOMEM;
114         }
115
116         atomic_set(&ax25_rt->ref, 0);
117         ax25_rt->callsign     = route->dest_addr;
118         ax25_rt->dev          = ax25_dev->dev;
119         ax25_rt->digipeat     = NULL;
120         ax25_rt->ip_mode      = ' ';
121         if (route->digi_count != 0) {
122                 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
123                         write_unlock(&ax25_route_lock);
124                         kfree(ax25_rt);
125                         return -ENOMEM;
126                 }
127                 ax25_rt->digipeat->lastrepeat = -1;
128                 ax25_rt->digipeat->ndigi      = route->digi_count;
129                 for (i = 0; i < route->digi_count; i++) {
130                         ax25_rt->digipeat->repeated[i] = 0;
131                         ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
132                 }
133         }
134         ax25_rt->next   = ax25_route_list;
135         ax25_route_list = ax25_rt;
136         write_unlock(&ax25_route_lock);
137
138         return 0;
139 }
140
141 static void ax25_rt_destroy(ax25_route *ax25_rt)
142 {
143         if (atomic_read(&ax25_rt->ref) == 0) {
144                 kfree(ax25_rt->digipeat);
145                 kfree(ax25_rt);
146                 return;
147         }
148
149         /*
150          * Uh...  Route is still in use; we can't yet destroy it.  Retry later.
151          */
152         init_timer(&ax25_rt->timer);
153         ax25_rt->timer.data     = (unsigned long) ax25_rt;
154         ax25_rt->timer.function = (void *) ax25_rt_destroy;
155         ax25_rt->timer.expires  = jiffies + 5 * HZ;
156
157         add_timer(&ax25_rt->timer);
158 }
159
160 static int ax25_rt_del(struct ax25_routes_struct *route)
161 {
162         ax25_route *s, *t, *ax25_rt;
163         ax25_dev *ax25_dev;
164
165         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
166                 return -EINVAL;
167
168         write_lock(&ax25_route_lock);
169
170         ax25_rt = ax25_route_list;
171         while (ax25_rt != NULL) {
172                 s       = ax25_rt;
173                 ax25_rt = ax25_rt->next;
174                 if (s->dev == ax25_dev->dev &&
175                     ax25cmp(&route->dest_addr, &s->callsign) == 0) {
176                         if (ax25_route_list == s) {
177                                 ax25_route_list = s->next;
178                                 ax25_rt_destroy(s);
179                         } else {
180                                 for (t = ax25_route_list; t != NULL; t = t->next) {
181                                         if (t->next == s) {
182                                                 t->next = s->next;
183                                                 ax25_rt_destroy(s);
184                                                 break;
185                                         }
186                                 }
187                         }
188                 }
189         }
190         write_unlock(&ax25_route_lock);
191
192         return 0;
193 }
194
195 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
196 {
197         ax25_route *ax25_rt;
198         ax25_dev *ax25_dev;
199         int err = 0;
200
201         if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
202                 return -EINVAL;
203
204         write_lock(&ax25_route_lock);
205
206         ax25_rt = ax25_route_list;
207         while (ax25_rt != NULL) {
208                 if (ax25_rt->dev == ax25_dev->dev &&
209                     ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
210                         switch (rt_option->cmd) {
211                         case AX25_SET_RT_IPMODE:
212                                 switch (rt_option->arg) {
213                                 case ' ':
214                                 case 'D':
215                                 case 'V':
216                                         ax25_rt->ip_mode = rt_option->arg;
217                                         break;
218                                 default:
219                                         err = -EINVAL;
220                                         goto out;
221                                 }
222                                 break;
223                         default:
224                                 err = -EINVAL;
225                                 goto out;
226                         }
227                 }
228                 ax25_rt = ax25_rt->next;
229         }
230
231 out:
232         write_unlock(&ax25_route_lock);
233         return err;
234 }
235
236 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
237 {
238         struct ax25_route_opt_struct rt_option;
239         struct ax25_routes_struct route;
240
241         switch (cmd) {
242         case SIOCADDRT:
243                 if (copy_from_user(&route, arg, sizeof(route)))
244                         return -EFAULT;
245                 return ax25_rt_add(&route);
246
247         case SIOCDELRT:
248                 if (copy_from_user(&route, arg, sizeof(route)))
249                         return -EFAULT;
250                 return ax25_rt_del(&route);
251
252         case SIOCAX25OPTRT:
253                 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
254                         return -EFAULT;
255                 return ax25_rt_opt(&rt_option);
256
257         default:
258                 return -EINVAL;
259         }
260 }
261
262 #ifdef CONFIG_PROC_FS
263
264 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
265 {
266         struct ax25_route *ax25_rt;
267         int i = 1;
268  
269         read_lock(&ax25_route_lock);
270         if (*pos == 0)
271                 return SEQ_START_TOKEN;
272
273         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
274                 if (i == *pos)
275                         return ax25_rt;
276                 ++i;
277         }
278
279         return NULL;
280 }
281
282 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
283 {
284         ++*pos;
285         return (v == SEQ_START_TOKEN) ? ax25_route_list : 
286                 ((struct ax25_route *) v)->next;
287 }
288
289 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
290 {
291         read_unlock(&ax25_route_lock);
292 }
293
294 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
295 {
296         char buf[11];
297
298         if (v == SEQ_START_TOKEN)
299                 seq_puts(seq, "callsign  dev  mode digipeaters\n");
300         else {
301                 struct ax25_route *ax25_rt = v;
302                 const char *callsign;
303                 int i;
304
305                 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
306                         callsign = "default";
307                 else
308                         callsign = ax2asc(buf, &ax25_rt->callsign);
309
310                 seq_printf(seq, "%-9s %-4s",
311                         callsign,
312                         ax25_rt->dev ? ax25_rt->dev->name : "???");
313
314                 switch (ax25_rt->ip_mode) {
315                 case 'V':
316                         seq_puts(seq, "   vc");
317                         break;
318                 case 'D':
319                         seq_puts(seq, "   dg");
320                         break;
321                 default:
322                         seq_puts(seq, "    *");
323                         break;
324                 }
325
326                 if (ax25_rt->digipeat != NULL)
327                         for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
328                                 seq_printf(seq, " %s",
329                                      ax2asc(buf, &ax25_rt->digipeat->calls[i]));
330
331                 seq_puts(seq, "\n");
332         }
333         return 0;
334 }
335
336 static struct seq_operations ax25_rt_seqops = {
337         .start = ax25_rt_seq_start,
338         .next = ax25_rt_seq_next,
339         .stop = ax25_rt_seq_stop,
340         .show = ax25_rt_seq_show,
341 };
342
343 static int ax25_rt_info_open(struct inode *inode, struct file *file)
344 {
345         return seq_open(file, &ax25_rt_seqops);
346 }
347
348 struct file_operations ax25_route_fops = {
349         .owner = THIS_MODULE,
350         .open = ax25_rt_info_open,
351         .read = seq_read,
352         .llseek = seq_lseek,
353         .release = seq_release,
354 };
355
356 #endif
357
358 /*
359  *      Find AX.25 route
360  *
361  *      Only routes with a refernce rout of zero can be destroyed.
362  */
363 static ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
364 {
365         ax25_route *ax25_spe_rt = NULL;
366         ax25_route *ax25_def_rt = NULL;
367         ax25_route *ax25_rt;
368
369         read_lock(&ax25_route_lock);
370         /*
371          *      Bind to the physical interface we heard them on, or the default
372          *      route if none is found;
373          */
374         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
375                 if (dev == NULL) {
376                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
377                                 ax25_spe_rt = ax25_rt;
378                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
379                                 ax25_def_rt = ax25_rt;
380                 } else {
381                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
382                                 ax25_spe_rt = ax25_rt;
383                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
384                                 ax25_def_rt = ax25_rt;
385                 }
386         }
387
388         ax25_rt = ax25_def_rt;
389         if (ax25_spe_rt != NULL)
390                 ax25_rt = ax25_spe_rt;
391
392         if (ax25_rt != NULL)
393                 atomic_inc(&ax25_rt->ref);
394
395         read_unlock(&ax25_route_lock);
396
397         return ax25_rt;
398 }
399
400 /*
401  *      Adjust path: If you specify a default route and want to connect
402  *      a target on the digipeater path but w/o having a special route
403  *      set before, the path has to be truncated from your target on.
404  */
405 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
406 {
407         int k;
408
409         for (k = 0; k < digipeat->ndigi; k++) {
410                 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
411                         break;
412         }
413
414         digipeat->ndigi = k;
415 }
416
417
418 /*
419  *      Find which interface to use.
420  */
421 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
422 {
423         ax25_uid_assoc *user;
424         ax25_route *ax25_rt;
425         int err;
426
427         if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL)
428                 return -EHOSTUNREACH;
429
430         if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
431                 err = -EHOSTUNREACH;
432                 goto put;
433         }
434
435         user = ax25_findbyuid(current->euid);
436         if (user) {
437                 ax25->source_addr = user->call;
438                 ax25_uid_put(user);
439         } else {
440                 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
441                         err = -EPERM;
442                         goto put;
443                 }
444                 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
445         }
446
447         if (ax25_rt->digipeat != NULL) {
448                 if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
449                         err = -ENOMEM;
450                         goto put;
451                 }
452                 memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi));
453                 ax25_adjust_path(addr, ax25->digipeat);
454         }
455
456         if (ax25->sk != NULL) {
457                 bh_lock_sock(ax25->sk);
458                 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
459                 bh_unlock_sock(ax25->sk);
460         }
461
462 put:
463         ax25_put_route(ax25_rt);
464
465         return 0;
466 }
467
468 ax25_route *ax25_rt_find_route(ax25_route * route, ax25_address *addr,
469         struct net_device *dev)
470 {
471         ax25_route *ax25_rt;
472
473         if ((ax25_rt = ax25_get_route(addr, dev)))
474                 return ax25_rt;
475
476         route->next     = NULL;
477         atomic_set(&route->ref, 1);
478         route->callsign = *addr;
479         route->dev      = dev;
480         route->digipeat = NULL;
481         route->ip_mode  = ' ';
482
483         return route;
484 }
485
486 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
487         ax25_address *dest, ax25_digi *digi)
488 {
489         struct sk_buff *skbn;
490         unsigned char *bp;
491         int len;
492
493         len = digi->ndigi * AX25_ADDR_LEN;
494
495         if (skb_headroom(skb) < len) {
496                 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
497                         printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
498                         return NULL;
499                 }
500
501                 if (skb->sk != NULL)
502                         skb_set_owner_w(skbn, skb->sk);
503
504                 kfree_skb(skb);
505
506                 skb = skbn;
507         }
508
509         bp = skb_push(skb, len);
510
511         ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
512
513         return skb;
514 }
515
516 /*
517  *      Free all memory associated with routing structures.
518  */
519 void __exit ax25_rt_free(void)
520 {
521         ax25_route *s, *ax25_rt = ax25_route_list;
522
523         write_lock(&ax25_route_lock);
524         while (ax25_rt != NULL) {
525                 s       = ax25_rt;
526                 ax25_rt = ax25_rt->next;
527
528                 kfree(s->digipeat);
529                 kfree(s);
530         }
531         write_unlock(&ax25_route_lock);
532 }