aboutsummaryrefslogtreecommitdiff
path: root/net/netfilter/x_tables.c
blob: 99293c63ff7348c71c38c9eaf3a3406876a0a3f3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
/*
 * x_tables core - Backend for {ip,ip6,arp}_tables
 *
 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
 *
 * Based on existing ip_tables code which is
 *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_arp.h>


MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");

#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))

struct xt_af {
	struct mutex mutex;
	struct list_head match;
	struct list_head target;
	struct list_head tables;
	struct mutex compat_mutex;
};

static struct xt_af *xt;

#ifdef DEBUG_IP_FIREWALL_USER
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif

enum {
	TABLE,
	TARGET,
	MATCH,
};

static const char *xt_prefix[NPROTO] = {
	[AF_INET] 	= "ip",
	[AF_INET6] 	= "ip6",
	[NF_ARP]	= "arp",
};

/* Registration hooks for targets. */
int
xt_register_target(struct xt_target *target)
{
	int ret, af = target->family;

	ret = mutex_lock_interruptible(&xt[af].mutex);
	if (ret != 0)
		return ret;
	list_add(&target->list, &xt[af].target);
	mutex_unlock(&xt[af].mutex);
	return ret;
}
EXPORT_SYMBOL(xt_register_target);

void
xt_unregister_target(struct xt_target *target)
{
	int af = target->family;

	mutex_lock(&xt[af].mutex);
	LIST_DELETE(&xt[af].target, target);
	mutex_unlock(&xt[af].mutex);
}
EXPORT_SYMBOL(xt_unregister_target);

int
xt_register_match(struct xt_match *match)
{
	int ret, af = match->family;

	ret = mutex_lock_interruptible(&xt[af].mutex);
	if (ret != 0)
		return ret;

	list_add(&match->list, &xt[af].match);
	mutex_unlock(&xt[af].mutex);

	return ret;
}
EXPORT_SYMBOL(xt_register_match);

void
xt_unregister_match(struct xt_match *match)
{
	int af =  match->family;

	mutex_lock(&xt[af].mutex);
	LIST_DELETE(&xt[af].match, match);
	mutex_unlock(&xt[af].mutex);
}
EXPORT_SYMBOL(xt_unregister_match);


/*
 * These are weird, but module loading must not be done with mutex
 * held (since they will register), and we have to have a single
 * function to use try_then_request_module().
 */

/* Find match, grabs ref.  Returns ERR_PTR() on error. */
struct xt_match *xt_find_match(int af, const char *name, u8 revision)
{
	struct xt_match *m;
	int err = 0;

	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
		return ERR_PTR(-EINTR);

	list_for_each_entry(m, &xt[af].match, list) {
		if (strcmp(m->name, name) == 0) {
			if (m->revision == revision) {
				if (try_module_get(m->me)) {
					mutex_unlock(&xt[af].mutex);
					return m;
				}
			} else
				err = -EPROTOTYPE; /* Found something. */
		}
	}
	mutex_unlock(&xt[af].mutex);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(xt_find_match);

/* Find target, grabs ref.  Returns ERR_PTR() on error. */
struct xt_target *xt_find_target(int af, const char *name, u8 revision)
{
	struct xt_target *t;
	int err = 0;

	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
		return ERR_PTR(-EINTR);

	list_for_each_entry(t, &xt[af].target, list) {
		if (strcmp(t->name, name) == 0) {
			if (t->revision == revision) {
				if (try_module_get(t->me)) {
					mutex_unlock(&xt[af].mutex);
					return t;
				}
			} else
				err = -EPROTOTYPE; /* Found something. */
		}
	}
	mutex_unlock(&xt[af].mutex);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(xt_find_target);

struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
{
	struct xt_target *target;

	target = try_then_request_module(xt_find_target(af, name, revision),
					 "%st_%s", xt_prefix[af], name);
	if (IS_ERR(target) || !target)
		return NULL;
	return target;
}
EXPORT_SYMBOL_GPL(xt_request_find_target);

static int match_revfn(int af, const char *name, u8 revision, int *bestp)
{
	struct xt_match *m;
	int have_rev = 0;

	list_for_each_entry(m, &xt[af].match, list) {
		if (strcmp(m->name, name) == 0) {
			if (m->revision > *bestp)
				*bestp = m->revision;
			if (m->revision == revision)
				have_rev = 1;
		}
	}
	return have_rev;
}

static int target_revfn(int af, const char *name, u8 revision, int *bestp)
{
	struct xt_target *t;
	int have_rev = 0;

	list_for_each_entry(t, &xt[af].target, list) {
		if (strcmp(t->name, name) == 0) {
			if (t->revision > *bestp)
				*bestp = t->revision;
			if (t->revision == revision)
				have_rev = 1;
		}
	}
	return have_rev;
}

/* Returns true or false (if no such extension at all) */
int xt_find_revision(int af, const char *name, u8 revision, int target,
		     int *err)
{
	int have_rev, best = -1;

	if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
		*err = -EINTR;
		return 1;
	}
	if (target == 1)
		have_rev = target_revfn(af, name, revision, &best);
	else
		have_rev = match_revfn(af, name, revision, &best);
	mutex_unlock(&xt[af].mutex);

	/* Nothing at all?  Return 0 to try loading module. */
	if (best == -1) {
		*err = -ENOENT;
		return 0;
	}

	*err = best;
	if (!have_rev)
		*err = -EPROTONOSUPPORT;
	return 1;
}
EXPORT_SYMBOL_GPL(xt_find_revision);

int xt_check_match(const struct xt_match *match, unsigned short family,
                   unsigned int size, const char *table, unsigned int hook_mask,
		   unsigned short proto, int inv_proto)
{
	if (XT_ALIGN(match->matchsize) != size) {
		printk("%s_tables: %s match: invalid size %Zu != %u\n",
		       xt_prefix[family], match->name,
		       XT_ALIGN(match->matchsize), size);
		return -EINVAL;
	}
	if (match->table && strcmp(match->table, table)) {
		printk("%s_tables: %s match: only valid in %s table, not %s\n",
		       xt_prefix[family], match->name, match->table, table);
		return -EINVAL;
	}
	if (match->hooks && (hook_mask & ~match->hooks) != 0) {
		printk("%s_tables: %s match: bad hook_mask %u\n",
		       xt_prefix[family], match->name, hook_mask);
		return -EINVAL;
	}
	if (match->proto && (match->proto != proto || inv_proto)) {
		printk("%s_tables: %s match: only valid for protocol %u\n",
		       xt_prefix[family], match->name, match->proto);
		return -EINVAL;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(xt_check_match);

#ifdef CONFIG_COMPAT
int xt_compat_match(void *match, void **dstptr, int *size, int convert)
{
	struct xt_match *m;
	struct compat_xt_entry_match *pcompat_m;
	struct xt_entry_match *pm;
	u_int16_t msize;
	int off, ret;

	ret = 0;
	m = ((struct xt_entry_match *)match)->u.kernel.match;
	off = XT_ALIGN(m->matchsize) - COMPAT_XT_ALIGN(m->matchsize);
	switch (convert) {
		case COMPAT_TO_USER:
			pm = (struct xt_entry_match *)match;
			msize = pm->u.user.match_size;
			if (copy_to_user(*dstptr, pm, msize)) {
				ret = -EFAULT;
				break;
			}
			msize -= off;
			if (put_user(msize, (u_int16_t *)*dstptr))
				ret = -EFAULT;
			*size -= off;
			*dstptr += msize;
			break;
		case COMPAT_FROM_USER:
			pcompat_m = (struct compat_xt_entry_match *)match;
			pm = (struct xt_entry_match *)*dstptr;
			msize = pcompat_m->u.user.match_size;
			memcpy(pm, pcompat_m, msize);
			msize += off;
			pm->u.user.match_size = msize;
			*size += off;
			*dstptr += msize;
			break;
		case COMPAT_CALC_SIZE:
			*size += off;
			break;
		default:
			ret = -ENOPROTOOPT;
			break;
	}
	return ret;
}
EXPORT_SYMBOL_GPL(xt_compat_match);
#endif

int xt_check_target(const struct xt_target *target, unsigned short family,
		    unsigned int size, const char *table, unsigned int hook_mask,
		    unsigned short proto, int inv_proto)
{
	if (XT_ALIGN(target->targetsize) != size) {
		printk("%s_tables: %s target: invalid size %Zu != %u\n",
		       xt_prefix[family], target->name,
		       XT_ALIGN(target->targetsize), size);
		return -EINVAL;
	}
	if (target->table && strcmp(target->table, table)) {
		printk("%s_tables: %s target: only valid in %s table, not %s\n",
		       xt_prefix[family], target->name, target->table, table);
		return -EINVAL;
	}
	if (target->hooks && (hook_mask & ~target->hooks) != 0) {
		printk("%s_tables: %s target: bad hook_mask %u\n",
		       xt_prefix[family], target->name, hook_mask);
		return -EINVAL;
	}
	if (target->proto && (target->proto != proto || inv_proto)) {
		printk("%s_tables: %s target: only valid for protocol %u\n",
		       xt_prefix[family], target->name, target->proto);
		return -EINVAL;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(xt_check_target);

#ifdef CONFIG_COMPAT
int xt_compat_target(void *target, void **dstptr, int *size, int convert)
{
	struct xt_target *t;
	struct compat_xt_entry_target *pcompat;
	struct xt_entry_target *pt;
	u_int16_t tsize;
	int off, ret;

	ret = 0;
	t = ((struct xt_entry_target *)target)->u.kernel.target;
	off = XT_ALIGN(t->targetsize) - COMPAT_XT_ALIGN(t->targetsize);
	switch (convert) {
		case COMPAT_TO_USER:
			pt = (struct xt_entry_target *)target;
			tsize = pt->u.user.target_size;
			if (copy_to_user(*dstptr, pt, tsize)) {
				ret = -EFAULT;
				break;
			}
			tsize -= off;
			if (put_user(tsize, (u_int16_t *)*dstptr))
				ret = -EFAULT;
			*size -= off;
			*dstptr += tsize;
			break;
		case COMPAT_FROM_USER:
			pcompat = (struct compat_xt_entry_target *)target;
			pt = (struct xt_entry_target *)*dstptr;
			tsize = pcompat->u.user.target_size;
			memcpy(pt, pcompat, tsize);
			tsize += off;
			pt->u.user.target_size = tsize;
			*size += off;
			*dstptr += tsize;
			break;
		case COMPAT_CALC_SIZE:
			*size += off;
			break;
		default:
			ret = -ENOPROTOOPT;
			break;
	}
	return ret;
}
EXPORT_SYMBOL_GPL(xt_compat_target);
#endif

struct xt_table_info *xt_alloc_table_info(unsigned int size)
{
	struct xt_table_info *newinfo;
	int cpu;

	/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
	if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
		return NULL;

	newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
	if (!newinfo)
		return NULL;

	newinfo->size = size;

	for_each_possible_cpu(cpu) {
		if (size <= PAGE_SIZE)
			newinfo->entries[cpu] = kmalloc_node(size,
							GFP_KERNEL,
							cpu_to_node(cpu));
		else
			newinfo->entries[cpu] = vmalloc_node(size,
							cpu_to_node(cpu));

		if (newinfo->entries[cpu] == NULL) {
			xt_free_table_info(newinfo);
			return NULL;
		}
	}

	return newinfo;
}
EXPORT_SYMBOL(xt_alloc_table_info);

void xt_free_table_info(struct xt_table_info *info)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		if (info->size <= PAGE_SIZE)
			kfree(info->entries[cpu]);
		else
			vfree(info->entries[cpu]);
	}
	kfree(info);
}
EXPORT_SYMBOL(xt_free_table_info);

/* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
struct xt_table *xt_find_table_lock(int af, const char *name)
{
	struct xt_table *t;

	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
		return ERR_PTR(-EINTR);

	list_for_each_entry(t, &xt[af].tables, list)
		if (strcmp(t->name, name) == 0 && try_module_get(t->me))
			return t;
	mutex_unlock(&xt[af].mutex);
	return NULL;
}
EXPORT_SYMBOL_GPL(xt_find_table_lock);

void xt_table_unlock(struct xt_table *table)
{
	mutex_unlock(&xt[table->af].mutex);
}
EXPORT_SYMBOL_GPL(xt_table_unlock);

#ifdef CONFIG_COMPAT
void xt_compat_lock(int af)
{
	mutex_lock(&xt[af].compat_mutex);
}
EXPORT_SYMBOL_GPL(xt_compat_lock);

void xt_compat_unlock(int af)
{
	mutex_unlock(&xt[af].compat_mutex);
}
EXPORT_SYMBOL_GPL(xt_compat_unlock);
#endif

struct xt_table_info *
xt_replace_table(struct xt_table *table,
	      unsigned int num_counters,
	      struct xt_table_info *newinfo,
	      int *error)
{
	struct xt_table_info *oldinfo, *private;

	/* Do the substitution. */
	write_lock_bh(&table->lock);
	private = table->private;
	/* Check inside lock: is the old number correct? */
	if (num_counters != private->number) {
		duprintf("num_counters != table->private->number (%u/%u)\n",
			 num_counters, private->number);
		write_unlock_bh(&table->lock);
		*error = -EAGAIN;
		return NULL;
	}
	oldinfo = private;
	table->private = newinfo;
	newinfo->initial_entries = oldinfo->initial_entries;
	write_unlock_bh(&table->lock);

	return oldinfo;
}
EXPORT_SYMBOL_GPL(xt_replace_table);

int xt_register_table(struct xt_table *table,
		      struct xt_table_info *bootstrap,
		      struct xt_table_info *newinfo)
{
	int ret;
	struct xt_table_info *private;

	ret = mutex_lock_interruptible(&xt[table->af].mutex);
	if (ret != 0)
		return ret;

	/* Don't autoload: we'd eat our tail... */
	if (list_named_find(&xt[table->af].tables, table->name)) {
		ret = -EEXIST;
		goto unlock;
	}

	/* Simplifies replace_table code. */
	table->private = bootstrap;
	rwlock_init(&table->lock);
	if (!xt_replace_table(table, 0, newinfo, &ret))
		goto unlock;

	private = table->private;
	duprintf("table->private->number = %u\n", private->number);

	/* save number of initial entries */
	private->initial_entries = private->number;

	list_prepend(&xt[table->af].tables, table);

	ret = 0;
 unlock:
	mutex_unlock(&xt[table->af].mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(xt_register_table);

void *xt_unregister_table(struct xt_table *table)
{
	struct xt_table_info *private;

	mutex_lock(&xt[table->af].mutex);
	private = table->private;
	LIST_DELETE(&xt[table->af].tables, table);
	mutex_unlock(&xt[table->af].mutex);

	return private;
}
EXPORT_SYMBOL_GPL(xt_unregister_table);

#ifdef CONFIG_PROC_FS
static char *xt_proto_prefix[NPROTO] = {
	[AF_INET]	= "ip",
	[AF_INET6]	= "ip6",
	[NF_ARP]	= "arp",
};

static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
{
	struct list_head *head = list->next;

	if (!head || list_empty(list))
		return NULL;

	while (pos && (head = head->next)) {
		if (head == list)
			return NULL;
		pos--;
	}
	return pos ? NULL : head;
}

static struct list_head *type2list(u_int16_t af, u_int16_t type)
{
	struct list_head *list;

	switch (type) {
	case TARGET:
		list = &xt[af].target;
		break;
	case MATCH:
		list = &xt[af].match;
		break;
	case TABLE:
		list = &xt[af].tables;
		break;
	default:
		list = NULL;
		break;
	}

	return list;
}

static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
{
	struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
	u_int16_t af = (unsigned long)pde->data & 0xffff;
	u_int16_t type = (unsigned long)pde->data >> 16;
	struct list_head *list;

	if (af >= NPROTO)
		return NULL;

	list = type2list(af, type);
	if (!list)
		return NULL;

	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
		return NULL;
	
	return xt_get_idx(list, seq, *pos);
}

static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct proc_dir_entry *pde = seq->private;
	u_int16_t af = (unsigned long)pde->data & 0xffff;
	u_int16_t type = (unsigned long)pde->data >> 16;
	struct list_head *list;

	if (af >= NPROTO)
		return NULL;
	
	list = type2list(af, type);
	if (!list)
		return NULL;

	(*pos)++;
	return xt_get_idx(list, seq, *pos);
}

static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
{
	struct proc_dir_entry *pde = seq->private;
	u_int16_t af = (unsigned long)pde->data & 0xffff;

	mutex_unlock(&xt[af].mutex);
}

static int xt_name_seq_show(struct seq_file *seq, void *v)
{
	char *name = (char *)v + sizeof(struct list_head);

	if (strlen(name))
		return seq_printf(seq, "%s\n", name);
	else
		return 0;
}

static struct seq_operations xt_tgt_seq_ops = {
	.start	= xt_tgt_seq_start,
	.next	= xt_tgt_seq_next,
	.stop	= xt_tgt_seq_stop,
	.show	= xt_name_seq_show,
};

static int xt_tgt_open(struct inode *inode, struct file *file)
{
	int ret;

	ret = seq_open(file, &xt_tgt_seq_ops);
	if (!ret) {
		struct seq_file *seq = file->private_data;
		struct proc_dir_entry *pde = PDE(inode);

		seq->private = pde;
	}

	return ret;
}

static struct file_operations xt_file_ops = {
	.owner	 = THIS_MODULE,
	.open	 = xt_tgt_open,
	.read	 = seq_read,
	.llseek	 = seq_lseek,
	.release = seq_release,
};

#define FORMAT_TABLES	"_tables_names"
#define	FORMAT_MATCHES	"_tables_matches"
#define FORMAT_TARGETS 	"_tables_targets"

#endif /* CONFIG_PROC_FS */

int xt_proto_init(int af)
{
#ifdef CONFIG_PROC_FS
	char buf[XT_FUNCTION_MAXNAMELEN];
	struct proc_dir_entry *proc;
#endif

	if (af >= NPROTO)
		return -EINVAL;


#ifdef CONFIG_PROC_FS
	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_TABLES, sizeof(buf));
	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
	if (!proc)
		goto out;
	proc->data = (void *) ((unsigned long) af | (TABLE << 16));


	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
	if (!proc)
		goto out_remove_tables;
	proc->data = (void *) ((unsigned long) af | (MATCH << 16));

	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
	if (!proc)
		goto out_remove_matches;
	proc->data = (void *) ((unsigned long) af | (TARGET << 16));
#endif

	return 0;

#ifdef CONFIG_PROC_FS
out_remove_matches:
	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
	proc_net_remove(buf);

out_remove_tables:
	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_TABLES, sizeof(buf));
	proc_net_remove(buf);
out:
	return -1;
#endif
}
EXPORT_SYMBOL_GPL(xt_proto_init);

void xt_proto_fini(int af)
{
#ifdef CONFIG_PROC_FS
	char buf[XT_FUNCTION_MAXNAMELEN];

	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_TABLES, sizeof(buf));
	proc_net_remove(buf);

	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
	proc_net_remove(buf);

	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
	proc_net_remove(buf);
#endif /*CONFIG_PROC_FS*/
}
EXPORT_SYMBOL_GPL(xt_proto_fini);


static int __init xt_init(void)
{
	int i;

	xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
	if (!xt)
		return -ENOMEM;

	for (i = 0; i < NPROTO; i++) {
		mutex_init(&xt[i].mutex);
#ifdef CONFIG_COMPAT
		mutex_init(&xt[i].compat_mutex);
#endif
		INIT_LIST_HEAD(&xt[i].target);
		INIT_LIST_HEAD(&xt[i].match);
		INIT_LIST_HEAD(&xt[i].tables);
	}
	return 0;
}

static void __exit xt_fini(void)
{
	kfree(xt);
}

module_init(xt_init);
module_exit(xt_fini);