1 /*
2  * x_tables core - Backend for {ip,ip6,arp}_tables
3  *
4  * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
5  *
6  * Based on existing ip_tables code which is
7  *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
8  *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  */
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/socket.h>
19 #include <linux/net.h>
20 #include <linux/proc_fs.h>
21 #include <linux/seq_file.h>
22 #include <linux/string.h>
23 #include <linux/vmalloc.h>
24 #include <linux/mutex.h>
25 #include <linux/mm.h>
26 #include <linux/slab.h>
27 #include <linux/audit.h>
28 #include <net/net_namespace.h>
29 
30 #include <linux/netfilter/x_tables.h>
31 #include <linux/netfilter_arp.h>
32 #include <linux/netfilter_ipv4/ip_tables.h>
33 #include <linux/netfilter_ipv6/ip6_tables.h>
34 #include <linux/netfilter_arp/arp_tables.h>
35 
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
38 MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
39 
40 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
41 
42 struct compat_delta {
43 	unsigned int offset; /* offset in kernel */
44 	int delta; /* delta in 32bit user land */
45 };
46 
47 struct xt_af {
48 	struct mutex mutex;
49 	struct list_head match;
50 	struct list_head target;
51 #ifdef CONFIG_COMPAT
52 	struct mutex compat_mutex;
53 	struct compat_delta *compat_tab;
54 	unsigned int number; /* number of slots in compat_tab[] */
55 	unsigned int cur; /* number of used slots in compat_tab[] */
56 #endif
57 };
58 
59 static struct xt_af *xt;
60 
61 static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
62 	[NFPROTO_UNSPEC] = "x",
63 	[NFPROTO_IPV4]   = "ip",
64 	[NFPROTO_ARP]    = "arp",
65 	[NFPROTO_BRIDGE] = "eb",
66 	[NFPROTO_IPV6]   = "ip6",
67 };
68 
69 /* Allow this many total (re)entries. */
70 static const unsigned int xt_jumpstack_multiplier = 2;
71 
72 /* Registration hooks for targets. */
73 int
xt_register_target(struct xt_target * target)74 xt_register_target(struct xt_target *target)
75 {
76 	u_int8_t af = target->family;
77 	int ret;
78 
79 	ret = mutex_lock_interruptible(&xt[af].mutex);
80 	if (ret != 0)
81 		return ret;
82 	list_add(&target->list, &xt[af].target);
83 	mutex_unlock(&xt[af].mutex);
84 	return ret;
85 }
86 EXPORT_SYMBOL(xt_register_target);
87 
88 void
xt_unregister_target(struct xt_target * target)89 xt_unregister_target(struct xt_target *target)
90 {
91 	u_int8_t af = target->family;
92 
93 	mutex_lock(&xt[af].mutex);
94 	list_del(&target->list);
95 	mutex_unlock(&xt[af].mutex);
96 }
97 EXPORT_SYMBOL(xt_unregister_target);
98 
99 int
xt_register_targets(struct xt_target * target,unsigned int n)100 xt_register_targets(struct xt_target *target, unsigned int n)
101 {
102 	unsigned int i;
103 	int err = 0;
104 
105 	for (i = 0; i < n; i++) {
106 		err = xt_register_target(&target[i]);
107 		if (err)
108 			goto err;
109 	}
110 	return err;
111 
112 err:
113 	if (i > 0)
114 		xt_unregister_targets(target, i);
115 	return err;
116 }
117 EXPORT_SYMBOL(xt_register_targets);
118 
119 void
xt_unregister_targets(struct xt_target * target,unsigned int n)120 xt_unregister_targets(struct xt_target *target, unsigned int n)
121 {
122 	while (n-- > 0)
123 		xt_unregister_target(&target[n]);
124 }
125 EXPORT_SYMBOL(xt_unregister_targets);
126 
127 int
xt_register_match(struct xt_match * match)128 xt_register_match(struct xt_match *match)
129 {
130 	u_int8_t af = match->family;
131 	int ret;
132 
133 	ret = mutex_lock_interruptible(&xt[af].mutex);
134 	if (ret != 0)
135 		return ret;
136 
137 	list_add(&match->list, &xt[af].match);
138 	mutex_unlock(&xt[af].mutex);
139 
140 	return ret;
141 }
142 EXPORT_SYMBOL(xt_register_match);
143 
144 void
xt_unregister_match(struct xt_match * match)145 xt_unregister_match(struct xt_match *match)
146 {
147 	u_int8_t af = match->family;
148 
149 	mutex_lock(&xt[af].mutex);
150 	list_del(&match->list);
151 	mutex_unlock(&xt[af].mutex);
152 }
153 EXPORT_SYMBOL(xt_unregister_match);
154 
155 int
xt_register_matches(struct xt_match * match,unsigned int n)156 xt_register_matches(struct xt_match *match, unsigned int n)
157 {
158 	unsigned int i;
159 	int err = 0;
160 
161 	for (i = 0; i < n; i++) {
162 		err = xt_register_match(&match[i]);
163 		if (err)
164 			goto err;
165 	}
166 	return err;
167 
168 err:
169 	if (i > 0)
170 		xt_unregister_matches(match, i);
171 	return err;
172 }
173 EXPORT_SYMBOL(xt_register_matches);
174 
175 void
xt_unregister_matches(struct xt_match * match,unsigned int n)176 xt_unregister_matches(struct xt_match *match, unsigned int n)
177 {
178 	while (n-- > 0)
179 		xt_unregister_match(&match[n]);
180 }
181 EXPORT_SYMBOL(xt_unregister_matches);
182 
183 
184 /*
185  * These are weird, but module loading must not be done with mutex
186  * held (since they will register), and we have to have a single
187  * function to use.
188  */
189 
190 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
xt_find_match(u8 af,const char * name,u8 revision)191 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
192 {
193 	struct xt_match *m;
194 	int err = -ENOENT;
195 
196 	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
197 		return ERR_PTR(-EINTR);
198 
199 	list_for_each_entry(m, &xt[af].match, list) {
200 		if (strcmp(m->name, name) == 0) {
201 			if (m->revision == revision) {
202 				if (try_module_get(m->me)) {
203 					mutex_unlock(&xt[af].mutex);
204 					return m;
205 				}
206 			} else
207 				err = -EPROTOTYPE; /* Found something. */
208 		}
209 	}
210 	mutex_unlock(&xt[af].mutex);
211 
212 	if (af != NFPROTO_UNSPEC)
213 		/* Try searching again in the family-independent list */
214 		return xt_find_match(NFPROTO_UNSPEC, name, revision);
215 
216 	return ERR_PTR(err);
217 }
218 EXPORT_SYMBOL(xt_find_match);
219 
220 struct xt_match *
xt_request_find_match(uint8_t nfproto,const char * name,uint8_t revision)221 xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
222 {
223 	struct xt_match *match;
224 
225 	match = xt_find_match(nfproto, name, revision);
226 	if (IS_ERR(match)) {
227 		request_module("%st_%s", xt_prefix[nfproto], name);
228 		match = xt_find_match(nfproto, name, revision);
229 	}
230 
231 	return match;
232 }
233 EXPORT_SYMBOL_GPL(xt_request_find_match);
234 
235 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
xt_find_target(u8 af,const char * name,u8 revision)236 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
237 {
238 	struct xt_target *t;
239 	int err = -ENOENT;
240 
241 	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
242 		return ERR_PTR(-EINTR);
243 
244 	list_for_each_entry(t, &xt[af].target, list) {
245 		if (strcmp(t->name, name) == 0) {
246 			if (t->revision == revision) {
247 				if (try_module_get(t->me)) {
248 					mutex_unlock(&xt[af].mutex);
249 					return t;
250 				}
251 			} else
252 				err = -EPROTOTYPE; /* Found something. */
253 		}
254 	}
255 	mutex_unlock(&xt[af].mutex);
256 
257 	if (af != NFPROTO_UNSPEC)
258 		/* Try searching again in the family-independent list */
259 		return xt_find_target(NFPROTO_UNSPEC, name, revision);
260 
261 	return ERR_PTR(err);
262 }
263 EXPORT_SYMBOL(xt_find_target);
264 
xt_request_find_target(u8 af,const char * name,u8 revision)265 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
266 {
267 	struct xt_target *target;
268 
269 	target = xt_find_target(af, name, revision);
270 	if (IS_ERR(target)) {
271 		request_module("%st_%s", xt_prefix[af], name);
272 		target = xt_find_target(af, name, revision);
273 	}
274 
275 	return target;
276 }
277 EXPORT_SYMBOL_GPL(xt_request_find_target);
278 
match_revfn(u8 af,const char * name,u8 revision,int * bestp)279 static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
280 {
281 	const struct xt_match *m;
282 	int have_rev = 0;
283 
284 	list_for_each_entry(m, &xt[af].match, list) {
285 		if (strcmp(m->name, name) == 0) {
286 			if (m->revision > *bestp)
287 				*bestp = m->revision;
288 			if (m->revision == revision)
289 				have_rev = 1;
290 		}
291 	}
292 
293 	if (af != NFPROTO_UNSPEC && !have_rev)
294 		return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
295 
296 	return have_rev;
297 }
298 
target_revfn(u8 af,const char * name,u8 revision,int * bestp)299 static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
300 {
301 	const struct xt_target *t;
302 	int have_rev = 0;
303 
304 	list_for_each_entry(t, &xt[af].target, list) {
305 		if (strcmp(t->name, name) == 0) {
306 			if (t->revision > *bestp)
307 				*bestp = t->revision;
308 			if (t->revision == revision)
309 				have_rev = 1;
310 		}
311 	}
312 
313 	if (af != NFPROTO_UNSPEC && !have_rev)
314 		return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
315 
316 	return have_rev;
317 }
318 
319 /* Returns true or false (if no such extension at all) */
xt_find_revision(u8 af,const char * name,u8 revision,int target,int * err)320 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
321 		     int *err)
322 {
323 	int have_rev, best = -1;
324 
325 	if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
326 		*err = -EINTR;
327 		return 1;
328 	}
329 	if (target == 1)
330 		have_rev = target_revfn(af, name, revision, &best);
331 	else
332 		have_rev = match_revfn(af, name, revision, &best);
333 	mutex_unlock(&xt[af].mutex);
334 
335 	/* Nothing at all?  Return 0 to try loading module. */
336 	if (best == -1) {
337 		*err = -ENOENT;
338 		return 0;
339 	}
340 
341 	*err = best;
342 	if (!have_rev)
343 		*err = -EPROTONOSUPPORT;
344 	return 1;
345 }
346 EXPORT_SYMBOL_GPL(xt_find_revision);
347 
textify_hooks(char * buf,size_t size,unsigned int mask)348 static char *textify_hooks(char *buf, size_t size, unsigned int mask)
349 {
350 	static const char *const names[] = {
351 		"PREROUTING", "INPUT", "FORWARD",
352 		"OUTPUT", "POSTROUTING", "BROUTING",
353 	};
354 	unsigned int i;
355 	char *p = buf;
356 	bool np = false;
357 	int res;
358 
359 	*p = '\0';
360 	for (i = 0; i < ARRAY_SIZE(names); ++i) {
361 		if (!(mask & (1 << i)))
362 			continue;
363 		res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
364 		if (res > 0) {
365 			size -= res;
366 			p += res;
367 		}
368 		np = true;
369 	}
370 
371 	return buf;
372 }
373 
xt_check_match(struct xt_mtchk_param * par,unsigned int size,u_int8_t proto,bool inv_proto)374 int xt_check_match(struct xt_mtchk_param *par,
375 		   unsigned int size, u_int8_t proto, bool inv_proto)
376 {
377 	int ret;
378 
379 	if (XT_ALIGN(par->match->matchsize) != size &&
380 	    par->match->matchsize != -1) {
381 		/*
382 		 * ebt_among is exempt from centralized matchsize checking
383 		 * because it uses a dynamic-size data set.
384 		 */
385 		pr_err("%s_tables: %s.%u match: invalid size "
386 		       "%u (kernel) != (user) %u\n",
387 		       xt_prefix[par->family], par->match->name,
388 		       par->match->revision,
389 		       XT_ALIGN(par->match->matchsize), size);
390 		return -EINVAL;
391 	}
392 	if (par->match->table != NULL &&
393 	    strcmp(par->match->table, par->table) != 0) {
394 		pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
395 		       xt_prefix[par->family], par->match->name,
396 		       par->match->table, par->table);
397 		return -EINVAL;
398 	}
399 	if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
400 		char used[64], allow[64];
401 
402 		pr_err("%s_tables: %s match: used from hooks %s, but only "
403 		       "valid from %s\n",
404 		       xt_prefix[par->family], par->match->name,
405 		       textify_hooks(used, sizeof(used), par->hook_mask),
406 		       textify_hooks(allow, sizeof(allow), par->match->hooks));
407 		return -EINVAL;
408 	}
409 	if (par->match->proto && (par->match->proto != proto || inv_proto)) {
410 		pr_err("%s_tables: %s match: only valid for protocol %u\n",
411 		       xt_prefix[par->family], par->match->name,
412 		       par->match->proto);
413 		return -EINVAL;
414 	}
415 	if (par->match->checkentry != NULL) {
416 		ret = par->match->checkentry(par);
417 		if (ret < 0)
418 			return ret;
419 		else if (ret > 0)
420 			/* Flag up potential errors. */
421 			return -EIO;
422 	}
423 	return 0;
424 }
425 EXPORT_SYMBOL_GPL(xt_check_match);
426 
427 #ifdef CONFIG_COMPAT
xt_compat_add_offset(u_int8_t af,unsigned int offset,int delta)428 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
429 {
430 	struct xt_af *xp = &xt[af];
431 
432 	if (!xp->compat_tab) {
433 		if (!xp->number)
434 			return -EINVAL;
435 		xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
436 		if (!xp->compat_tab)
437 			return -ENOMEM;
438 		xp->cur = 0;
439 	}
440 
441 	if (xp->cur >= xp->number)
442 		return -EINVAL;
443 
444 	if (xp->cur)
445 		delta += xp->compat_tab[xp->cur - 1].delta;
446 	xp->compat_tab[xp->cur].offset = offset;
447 	xp->compat_tab[xp->cur].delta = delta;
448 	xp->cur++;
449 	return 0;
450 }
451 EXPORT_SYMBOL_GPL(xt_compat_add_offset);
452 
xt_compat_flush_offsets(u_int8_t af)453 void xt_compat_flush_offsets(u_int8_t af)
454 {
455 	if (xt[af].compat_tab) {
456 		vfree(xt[af].compat_tab);
457 		xt[af].compat_tab = NULL;
458 		xt[af].number = 0;
459 		xt[af].cur = 0;
460 	}
461 }
462 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
463 
xt_compat_calc_jump(u_int8_t af,unsigned int offset)464 int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
465 {
466 	struct compat_delta *tmp = xt[af].compat_tab;
467 	int mid, left = 0, right = xt[af].cur - 1;
468 
469 	while (left <= right) {
470 		mid = (left + right) >> 1;
471 		if (offset > tmp[mid].offset)
472 			left = mid + 1;
473 		else if (offset < tmp[mid].offset)
474 			right = mid - 1;
475 		else
476 			return mid ? tmp[mid - 1].delta : 0;
477 	}
478 	return left ? tmp[left - 1].delta : 0;
479 }
480 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
481 
xt_compat_init_offsets(u_int8_t af,unsigned int number)482 void xt_compat_init_offsets(u_int8_t af, unsigned int number)
483 {
484 	xt[af].number = number;
485 	xt[af].cur = 0;
486 }
487 EXPORT_SYMBOL(xt_compat_init_offsets);
488 
xt_compat_match_offset(const struct xt_match * match)489 int xt_compat_match_offset(const struct xt_match *match)
490 {
491 	u_int16_t csize = match->compatsize ? : match->matchsize;
492 	return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
493 }
494 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
495 
xt_compat_match_from_user(struct xt_entry_match * m,void ** dstptr,unsigned int * size)496 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
497 			      unsigned int *size)
498 {
499 	const struct xt_match *match = m->u.kernel.match;
500 	struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
501 	int pad, off = xt_compat_match_offset(match);
502 	u_int16_t msize = cm->u.user.match_size;
503 
504 	m = *dstptr;
505 	memcpy(m, cm, sizeof(*cm));
506 	if (match->compat_from_user)
507 		match->compat_from_user(m->data, cm->data);
508 	else
509 		memcpy(m->data, cm->data, msize - sizeof(*cm));
510 	pad = XT_ALIGN(match->matchsize) - match->matchsize;
511 	if (pad > 0)
512 		memset(m->data + match->matchsize, 0, pad);
513 
514 	msize += off;
515 	m->u.user.match_size = msize;
516 
517 	*size += off;
518 	*dstptr += msize;
519 	return 0;
520 }
521 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
522 
xt_compat_match_to_user(const struct xt_entry_match * m,void __user ** dstptr,unsigned int * size)523 int xt_compat_match_to_user(const struct xt_entry_match *m,
524 			    void __user **dstptr, unsigned int *size)
525 {
526 	const struct xt_match *match = m->u.kernel.match;
527 	struct compat_xt_entry_match __user *cm = *dstptr;
528 	int off = xt_compat_match_offset(match);
529 	u_int16_t msize = m->u.user.match_size - off;
530 
531 	if (copy_to_user(cm, m, sizeof(*cm)) ||
532 	    put_user(msize, &cm->u.user.match_size) ||
533 	    copy_to_user(cm->u.user.name, m->u.kernel.match->name,
534 			 strlen(m->u.kernel.match->name) + 1))
535 		return -EFAULT;
536 
537 	if (match->compat_to_user) {
538 		if (match->compat_to_user((void __user *)cm->data, m->data))
539 			return -EFAULT;
540 	} else {
541 		if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
542 			return -EFAULT;
543 	}
544 
545 	*size -= off;
546 	*dstptr += msize;
547 	return 0;
548 }
549 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
550 #endif /* CONFIG_COMPAT */
551 
xt_check_target(struct xt_tgchk_param * par,unsigned int size,u_int8_t proto,bool inv_proto)552 int xt_check_target(struct xt_tgchk_param *par,
553 		    unsigned int size, u_int8_t proto, bool inv_proto)
554 {
555 	int ret;
556 
557 	if (XT_ALIGN(par->target->targetsize) != size) {
558 		pr_err("%s_tables: %s.%u target: invalid size "
559 		       "%u (kernel) != (user) %u\n",
560 		       xt_prefix[par->family], par->target->name,
561 		       par->target->revision,
562 		       XT_ALIGN(par->target->targetsize), size);
563 		return -EINVAL;
564 	}
565 	if (par->target->table != NULL &&
566 	    strcmp(par->target->table, par->table) != 0) {
567 		pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
568 		       xt_prefix[par->family], par->target->name,
569 		       par->target->table, par->table);
570 		return -EINVAL;
571 	}
572 	if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
573 		char used[64], allow[64];
574 
575 		pr_err("%s_tables: %s target: used from hooks %s, but only "
576 		       "usable from %s\n",
577 		       xt_prefix[par->family], par->target->name,
578 		       textify_hooks(used, sizeof(used), par->hook_mask),
579 		       textify_hooks(allow, sizeof(allow), par->target->hooks));
580 		return -EINVAL;
581 	}
582 	if (par->target->proto && (par->target->proto != proto || inv_proto)) {
583 		pr_err("%s_tables: %s target: only valid for protocol %u\n",
584 		       xt_prefix[par->family], par->target->name,
585 		       par->target->proto);
586 		return -EINVAL;
587 	}
588 	if (par->target->checkentry != NULL) {
589 		ret = par->target->checkentry(par);
590 		if (ret < 0)
591 			return ret;
592 		else if (ret > 0)
593 			/* Flag up potential errors. */
594 			return -EIO;
595 	}
596 	return 0;
597 }
598 EXPORT_SYMBOL_GPL(xt_check_target);
599 
600 #ifdef CONFIG_COMPAT
xt_compat_target_offset(const struct xt_target * target)601 int xt_compat_target_offset(const struct xt_target *target)
602 {
603 	u_int16_t csize = target->compatsize ? : target->targetsize;
604 	return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
605 }
606 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
607 
xt_compat_target_from_user(struct xt_entry_target * t,void ** dstptr,unsigned int * size)608 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
609 				unsigned int *size)
610 {
611 	const struct xt_target *target = t->u.kernel.target;
612 	struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
613 	int pad, off = xt_compat_target_offset(target);
614 	u_int16_t tsize = ct->u.user.target_size;
615 
616 	t = *dstptr;
617 	memcpy(t, ct, sizeof(*ct));
618 	if (target->compat_from_user)
619 		target->compat_from_user(t->data, ct->data);
620 	else
621 		memcpy(t->data, ct->data, tsize - sizeof(*ct));
622 	pad = XT_ALIGN(target->targetsize) - target->targetsize;
623 	if (pad > 0)
624 		memset(t->data + target->targetsize, 0, pad);
625 
626 	tsize += off;
627 	t->u.user.target_size = tsize;
628 
629 	*size += off;
630 	*dstptr += tsize;
631 }
632 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
633 
xt_compat_target_to_user(const struct xt_entry_target * t,void __user ** dstptr,unsigned int * size)634 int xt_compat_target_to_user(const struct xt_entry_target *t,
635 			     void __user **dstptr, unsigned int *size)
636 {
637 	const struct xt_target *target = t->u.kernel.target;
638 	struct compat_xt_entry_target __user *ct = *dstptr;
639 	int off = xt_compat_target_offset(target);
640 	u_int16_t tsize = t->u.user.target_size - off;
641 
642 	if (copy_to_user(ct, t, sizeof(*ct)) ||
643 	    put_user(tsize, &ct->u.user.target_size) ||
644 	    copy_to_user(ct->u.user.name, t->u.kernel.target->name,
645 			 strlen(t->u.kernel.target->name) + 1))
646 		return -EFAULT;
647 
648 	if (target->compat_to_user) {
649 		if (target->compat_to_user((void __user *)ct->data, t->data))
650 			return -EFAULT;
651 	} else {
652 		if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
653 			return -EFAULT;
654 	}
655 
656 	*size -= off;
657 	*dstptr += tsize;
658 	return 0;
659 }
660 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
661 #endif
662 
xt_alloc_table_info(unsigned int size)663 struct xt_table_info *xt_alloc_table_info(unsigned int size)
664 {
665 	struct xt_table_info *newinfo;
666 	int cpu;
667 
668 	/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
669 	if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
670 		return NULL;
671 
672 	newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
673 	if (!newinfo)
674 		return NULL;
675 
676 	newinfo->size = size;
677 
678 	for_each_possible_cpu(cpu) {
679 		if (size <= PAGE_SIZE)
680 			newinfo->entries[cpu] = kmalloc_node(size,
681 							GFP_KERNEL,
682 							cpu_to_node(cpu));
683 		else
684 			newinfo->entries[cpu] = vmalloc_node(size,
685 							cpu_to_node(cpu));
686 
687 		if (newinfo->entries[cpu] == NULL) {
688 			xt_free_table_info(newinfo);
689 			return NULL;
690 		}
691 	}
692 
693 	return newinfo;
694 }
695 EXPORT_SYMBOL(xt_alloc_table_info);
696 
xt_free_table_info(struct xt_table_info * info)697 void xt_free_table_info(struct xt_table_info *info)
698 {
699 	int cpu;
700 
701 	for_each_possible_cpu(cpu) {
702 		if (info->size <= PAGE_SIZE)
703 			kfree(info->entries[cpu]);
704 		else
705 			vfree(info->entries[cpu]);
706 	}
707 
708 	if (info->jumpstack != NULL) {
709 		if (sizeof(void *) * info->stacksize > PAGE_SIZE) {
710 			for_each_possible_cpu(cpu)
711 				vfree(info->jumpstack[cpu]);
712 		} else {
713 			for_each_possible_cpu(cpu)
714 				kfree(info->jumpstack[cpu]);
715 		}
716 	}
717 
718 	if (sizeof(void **) * nr_cpu_ids > PAGE_SIZE)
719 		vfree(info->jumpstack);
720 	else
721 		kfree(info->jumpstack);
722 
723 	free_percpu(info->stackptr);
724 
725 	kfree(info);
726 }
727 EXPORT_SYMBOL(xt_free_table_info);
728 
729 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
xt_find_table_lock(struct net * net,u_int8_t af,const char * name)730 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
731 				    const char *name)
732 {
733 	struct xt_table *t;
734 
735 	if (mutex_lock_interruptible(&xt[af].mutex) != 0)
736 		return ERR_PTR(-EINTR);
737 
738 	list_for_each_entry(t, &net->xt.tables[af], list)
739 		if (strcmp(t->name, name) == 0 && try_module_get(t->me))
740 			return t;
741 	mutex_unlock(&xt[af].mutex);
742 	return NULL;
743 }
744 EXPORT_SYMBOL_GPL(xt_find_table_lock);
745 
xt_table_unlock(struct xt_table * table)746 void xt_table_unlock(struct xt_table *table)
747 {
748 	mutex_unlock(&xt[table->af].mutex);
749 }
750 EXPORT_SYMBOL_GPL(xt_table_unlock);
751 
752 #ifdef CONFIG_COMPAT
xt_compat_lock(u_int8_t af)753 void xt_compat_lock(u_int8_t af)
754 {
755 	mutex_lock(&xt[af].compat_mutex);
756 }
757 EXPORT_SYMBOL_GPL(xt_compat_lock);
758 
xt_compat_unlock(u_int8_t af)759 void xt_compat_unlock(u_int8_t af)
760 {
761 	mutex_unlock(&xt[af].compat_mutex);
762 }
763 EXPORT_SYMBOL_GPL(xt_compat_unlock);
764 #endif
765 
766 DEFINE_PER_CPU(seqcount_t, xt_recseq);
767 EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
768 
xt_jumpstack_alloc(struct xt_table_info * i)769 static int xt_jumpstack_alloc(struct xt_table_info *i)
770 {
771 	unsigned int size;
772 	int cpu;
773 
774 	i->stackptr = alloc_percpu(unsigned int);
775 	if (i->stackptr == NULL)
776 		return -ENOMEM;
777 
778 	size = sizeof(void **) * nr_cpu_ids;
779 	if (size > PAGE_SIZE)
780 		i->jumpstack = vzalloc(size);
781 	else
782 		i->jumpstack = kzalloc(size, GFP_KERNEL);
783 	if (i->jumpstack == NULL)
784 		return -ENOMEM;
785 
786 	i->stacksize *= xt_jumpstack_multiplier;
787 	size = sizeof(void *) * i->stacksize;
788 	for_each_possible_cpu(cpu) {
789 		if (size > PAGE_SIZE)
790 			i->jumpstack[cpu] = vmalloc_node(size,
791 				cpu_to_node(cpu));
792 		else
793 			i->jumpstack[cpu] = kmalloc_node(size,
794 				GFP_KERNEL, cpu_to_node(cpu));
795 		if (i->jumpstack[cpu] == NULL)
796 			/*
797 			 * Freeing will be done later on by the callers. The
798 			 * chain is: xt_replace_table -> __do_replace ->
799 			 * do_replace -> xt_free_table_info.
800 			 */
801 			return -ENOMEM;
802 	}
803 
804 	return 0;
805 }
806 
807 struct xt_table_info *
xt_replace_table(struct xt_table * table,unsigned int num_counters,struct xt_table_info * newinfo,int * error)808 xt_replace_table(struct xt_table *table,
809 	      unsigned int num_counters,
810 	      struct xt_table_info *newinfo,
811 	      int *error)
812 {
813 	struct xt_table_info *private;
814 	int ret;
815 
816 	ret = xt_jumpstack_alloc(newinfo);
817 	if (ret < 0) {
818 		*error = ret;
819 		return NULL;
820 	}
821 
822 	/* Do the substitution. */
823 	local_bh_disable();
824 	private = table->private;
825 
826 	/* Check inside lock: is the old number correct? */
827 	if (num_counters != private->number) {
828 		pr_debug("num_counters != table->private->number (%u/%u)\n",
829 			 num_counters, private->number);
830 		local_bh_enable();
831 		*error = -EAGAIN;
832 		return NULL;
833 	}
834 
835 	table->private = newinfo;
836 	newinfo->initial_entries = private->initial_entries;
837 
838 	/*
839 	 * Even though table entries have now been swapped, other CPU's
840 	 * may still be using the old entries. This is okay, because
841 	 * resynchronization happens because of the locking done
842 	 * during the get_counters() routine.
843 	 */
844 	local_bh_enable();
845 
846 #ifdef CONFIG_AUDIT
847 	if (audit_enabled) {
848 		struct audit_buffer *ab;
849 
850 		ab = audit_log_start(current->audit_context, GFP_KERNEL,
851 				     AUDIT_NETFILTER_CFG);
852 		if (ab) {
853 			audit_log_format(ab, "table=%s family=%u entries=%u",
854 					 table->name, table->af,
855 					 private->number);
856 			audit_log_end(ab);
857 		}
858 	}
859 #endif
860 
861 	return private;
862 }
863 EXPORT_SYMBOL_GPL(xt_replace_table);
864 
xt_register_table(struct net * net,const struct xt_table * input_table,struct xt_table_info * bootstrap,struct xt_table_info * newinfo)865 struct xt_table *xt_register_table(struct net *net,
866 				   const struct xt_table *input_table,
867 				   struct xt_table_info *bootstrap,
868 				   struct xt_table_info *newinfo)
869 {
870 	int ret;
871 	struct xt_table_info *private;
872 	struct xt_table *t, *table;
873 
874 	/* Don't add one object to multiple lists. */
875 	table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
876 	if (!table) {
877 		ret = -ENOMEM;
878 		goto out;
879 	}
880 
881 	ret = mutex_lock_interruptible(&xt[table->af].mutex);
882 	if (ret != 0)
883 		goto out_free;
884 
885 	/* Don't autoload: we'd eat our tail... */
886 	list_for_each_entry(t, &net->xt.tables[table->af], list) {
887 		if (strcmp(t->name, table->name) == 0) {
888 			ret = -EEXIST;
889 			goto unlock;
890 		}
891 	}
892 
893 	/* Simplifies replace_table code. */
894 	table->private = bootstrap;
895 
896 	if (!xt_replace_table(table, 0, newinfo, &ret))
897 		goto unlock;
898 
899 	private = table->private;
900 	pr_debug("table->private->number = %u\n", private->number);
901 
902 	/* save number of initial entries */
903 	private->initial_entries = private->number;
904 
905 	list_add(&table->list, &net->xt.tables[table->af]);
906 	mutex_unlock(&xt[table->af].mutex);
907 	return table;
908 
909  unlock:
910 	mutex_unlock(&xt[table->af].mutex);
911 out_free:
912 	kfree(table);
913 out:
914 	return ERR_PTR(ret);
915 }
916 EXPORT_SYMBOL_GPL(xt_register_table);
917 
xt_unregister_table(struct xt_table * table)918 void *xt_unregister_table(struct xt_table *table)
919 {
920 	struct xt_table_info *private;
921 
922 	mutex_lock(&xt[table->af].mutex);
923 	private = table->private;
924 	list_del(&table->list);
925 	mutex_unlock(&xt[table->af].mutex);
926 	kfree(table);
927 
928 	return private;
929 }
930 EXPORT_SYMBOL_GPL(xt_unregister_table);
931 
932 #ifdef CONFIG_PROC_FS
933 struct xt_names_priv {
934 	struct seq_net_private p;
935 	u_int8_t af;
936 };
xt_table_seq_start(struct seq_file * seq,loff_t * pos)937 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
938 {
939 	struct xt_names_priv *priv = seq->private;
940 	struct net *net = seq_file_net(seq);
941 	u_int8_t af = priv->af;
942 
943 	mutex_lock(&xt[af].mutex);
944 	return seq_list_start(&net->xt.tables[af], *pos);
945 }
946 
xt_table_seq_next(struct seq_file * seq,void * v,loff_t * pos)947 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
948 {
949 	struct xt_names_priv *priv = seq->private;
950 	struct net *net = seq_file_net(seq);
951 	u_int8_t af = priv->af;
952 
953 	return seq_list_next(v, &net->xt.tables[af], pos);
954 }
955 
xt_table_seq_stop(struct seq_file * seq,void * v)956 static void xt_table_seq_stop(struct seq_file *seq, void *v)
957 {
958 	struct xt_names_priv *priv = seq->private;
959 	u_int8_t af = priv->af;
960 
961 	mutex_unlock(&xt[af].mutex);
962 }
963 
xt_table_seq_show(struct seq_file * seq,void * v)964 static int xt_table_seq_show(struct seq_file *seq, void *v)
965 {
966 	struct xt_table *table = list_entry(v, struct xt_table, list);
967 
968 	if (strlen(table->name))
969 		return seq_printf(seq, "%s\n", table->name);
970 	else
971 		return 0;
972 }
973 
974 static const struct seq_operations xt_table_seq_ops = {
975 	.start	= xt_table_seq_start,
976 	.next	= xt_table_seq_next,
977 	.stop	= xt_table_seq_stop,
978 	.show	= xt_table_seq_show,
979 };
980 
xt_table_open(struct inode * inode,struct file * file)981 static int xt_table_open(struct inode *inode, struct file *file)
982 {
983 	int ret;
984 	struct xt_names_priv *priv;
985 
986 	ret = seq_open_net(inode, file, &xt_table_seq_ops,
987 			   sizeof(struct xt_names_priv));
988 	if (!ret) {
989 		priv = ((struct seq_file *)file->private_data)->private;
990 		priv->af = (unsigned long)PDE(inode)->data;
991 	}
992 	return ret;
993 }
994 
995 static const struct file_operations xt_table_ops = {
996 	.owner	 = THIS_MODULE,
997 	.open	 = xt_table_open,
998 	.read	 = seq_read,
999 	.llseek	 = seq_lseek,
1000 	.release = seq_release_net,
1001 };
1002 
1003 /*
1004  * Traverse state for ip{,6}_{tables,matches} for helping crossing
1005  * the multi-AF mutexes.
1006  */
1007 struct nf_mttg_trav {
1008 	struct list_head *head, *curr;
1009 	uint8_t class, nfproto;
1010 };
1011 
1012 enum {
1013 	MTTG_TRAV_INIT,
1014 	MTTG_TRAV_NFP_UNSPEC,
1015 	MTTG_TRAV_NFP_SPEC,
1016 	MTTG_TRAV_DONE,
1017 };
1018 
xt_mttg_seq_next(struct seq_file * seq,void * v,loff_t * ppos,bool is_target)1019 static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
1020     bool is_target)
1021 {
1022 	static const uint8_t next_class[] = {
1023 		[MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
1024 		[MTTG_TRAV_NFP_SPEC]   = MTTG_TRAV_DONE,
1025 	};
1026 	struct nf_mttg_trav *trav = seq->private;
1027 
1028 	switch (trav->class) {
1029 	case MTTG_TRAV_INIT:
1030 		trav->class = MTTG_TRAV_NFP_UNSPEC;
1031 		mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
1032 		trav->head = trav->curr = is_target ?
1033 			&xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
1034  		break;
1035 	case MTTG_TRAV_NFP_UNSPEC:
1036 		trav->curr = trav->curr->next;
1037 		if (trav->curr != trav->head)
1038 			break;
1039 		mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1040 		mutex_lock(&xt[trav->nfproto].mutex);
1041 		trav->head = trav->curr = is_target ?
1042 			&xt[trav->nfproto].target : &xt[trav->nfproto].match;
1043 		trav->class = next_class[trav->class];
1044 		break;
1045 	case MTTG_TRAV_NFP_SPEC:
1046 		trav->curr = trav->curr->next;
1047 		if (trav->curr != trav->head)
1048 			break;
1049 		/* fallthru, _stop will unlock */
1050 	default:
1051 		return NULL;
1052 	}
1053 
1054 	if (ppos != NULL)
1055 		++*ppos;
1056 	return trav;
1057 }
1058 
xt_mttg_seq_start(struct seq_file * seq,loff_t * pos,bool is_target)1059 static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
1060     bool is_target)
1061 {
1062 	struct nf_mttg_trav *trav = seq->private;
1063 	unsigned int j;
1064 
1065 	trav->class = MTTG_TRAV_INIT;
1066 	for (j = 0; j < *pos; ++j)
1067 		if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
1068 			return NULL;
1069 	return trav;
1070 }
1071 
xt_mttg_seq_stop(struct seq_file * seq,void * v)1072 static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
1073 {
1074 	struct nf_mttg_trav *trav = seq->private;
1075 
1076 	switch (trav->class) {
1077 	case MTTG_TRAV_NFP_UNSPEC:
1078 		mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1079 		break;
1080 	case MTTG_TRAV_NFP_SPEC:
1081 		mutex_unlock(&xt[trav->nfproto].mutex);
1082 		break;
1083 	}
1084 }
1085 
xt_match_seq_start(struct seq_file * seq,loff_t * pos)1086 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1087 {
1088 	return xt_mttg_seq_start(seq, pos, false);
1089 }
1090 
xt_match_seq_next(struct seq_file * seq,void * v,loff_t * ppos)1091 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1092 {
1093 	return xt_mttg_seq_next(seq, v, ppos, false);
1094 }
1095 
xt_match_seq_show(struct seq_file * seq,void * v)1096 static int xt_match_seq_show(struct seq_file *seq, void *v)
1097 {
1098 	const struct nf_mttg_trav *trav = seq->private;
1099 	const struct xt_match *match;
1100 
1101 	switch (trav->class) {
1102 	case MTTG_TRAV_NFP_UNSPEC:
1103 	case MTTG_TRAV_NFP_SPEC:
1104 		if (trav->curr == trav->head)
1105 			return 0;
1106 		match = list_entry(trav->curr, struct xt_match, list);
1107 		return (*match->name == '\0') ? 0 :
1108 		       seq_printf(seq, "%s\n", match->name);
1109 	}
1110 	return 0;
1111 }
1112 
1113 static const struct seq_operations xt_match_seq_ops = {
1114 	.start	= xt_match_seq_start,
1115 	.next	= xt_match_seq_next,
1116 	.stop	= xt_mttg_seq_stop,
1117 	.show	= xt_match_seq_show,
1118 };
1119 
xt_match_open(struct inode * inode,struct file * file)1120 static int xt_match_open(struct inode *inode, struct file *file)
1121 {
1122 	struct seq_file *seq;
1123 	struct nf_mttg_trav *trav;
1124 	int ret;
1125 
1126 	trav = kmalloc(sizeof(*trav), GFP_KERNEL);
1127 	if (trav == NULL)
1128 		return -ENOMEM;
1129 
1130 	ret = seq_open(file, &xt_match_seq_ops);
1131 	if (ret < 0) {
1132 		kfree(trav);
1133 		return ret;
1134 	}
1135 
1136 	seq = file->private_data;
1137 	seq->private = trav;
1138 	trav->nfproto = (unsigned long)PDE(inode)->data;
1139 	return 0;
1140 }
1141 
1142 static const struct file_operations xt_match_ops = {
1143 	.owner	 = THIS_MODULE,
1144 	.open	 = xt_match_open,
1145 	.read	 = seq_read,
1146 	.llseek	 = seq_lseek,
1147 	.release = seq_release_private,
1148 };
1149 
xt_target_seq_start(struct seq_file * seq,loff_t * pos)1150 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1151 {
1152 	return xt_mttg_seq_start(seq, pos, true);
1153 }
1154 
xt_target_seq_next(struct seq_file * seq,void * v,loff_t * ppos)1155 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1156 {
1157 	return xt_mttg_seq_next(seq, v, ppos, true);
1158 }
1159 
xt_target_seq_show(struct seq_file * seq,void * v)1160 static int xt_target_seq_show(struct seq_file *seq, void *v)
1161 {
1162 	const struct nf_mttg_trav *trav = seq->private;
1163 	const struct xt_target *target;
1164 
1165 	switch (trav->class) {
1166 	case MTTG_TRAV_NFP_UNSPEC:
1167 	case MTTG_TRAV_NFP_SPEC:
1168 		if (trav->curr == trav->head)
1169 			return 0;
1170 		target = list_entry(trav->curr, struct xt_target, list);
1171 		return (*target->name == '\0') ? 0 :
1172 		       seq_printf(seq, "%s\n", target->name);
1173 	}
1174 	return 0;
1175 }
1176 
1177 static const struct seq_operations xt_target_seq_ops = {
1178 	.start	= xt_target_seq_start,
1179 	.next	= xt_target_seq_next,
1180 	.stop	= xt_mttg_seq_stop,
1181 	.show	= xt_target_seq_show,
1182 };
1183 
xt_target_open(struct inode * inode,struct file * file)1184 static int xt_target_open(struct inode *inode, struct file *file)
1185 {
1186 	struct seq_file *seq;
1187 	struct nf_mttg_trav *trav;
1188 	int ret;
1189 
1190 	trav = kmalloc(sizeof(*trav), GFP_KERNEL);
1191 	if (trav == NULL)
1192 		return -ENOMEM;
1193 
1194 	ret = seq_open(file, &xt_target_seq_ops);
1195 	if (ret < 0) {
1196 		kfree(trav);
1197 		return ret;
1198 	}
1199 
1200 	seq = file->private_data;
1201 	seq->private = trav;
1202 	trav->nfproto = (unsigned long)PDE(inode)->data;
1203 	return 0;
1204 }
1205 
1206 static const struct file_operations xt_target_ops = {
1207 	.owner	 = THIS_MODULE,
1208 	.open	 = xt_target_open,
1209 	.read	 = seq_read,
1210 	.llseek	 = seq_lseek,
1211 	.release = seq_release_private,
1212 };
1213 
1214 #define FORMAT_TABLES	"_tables_names"
1215 #define	FORMAT_MATCHES	"_tables_matches"
1216 #define FORMAT_TARGETS 	"_tables_targets"
1217 
1218 #endif /* CONFIG_PROC_FS */
1219 
1220 /**
1221  * xt_hook_link - set up hooks for a new table
1222  * @table:	table with metadata needed to set up hooks
1223  * @fn:		Hook function
1224  *
1225  * This function will take care of creating and registering the necessary
1226  * Netfilter hooks for XT tables.
1227  */
xt_hook_link(const struct xt_table * table,nf_hookfn * fn)1228 struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn)
1229 {
1230 	unsigned int hook_mask = table->valid_hooks;
1231 	uint8_t i, num_hooks = hweight32(hook_mask);
1232 	uint8_t hooknum;
1233 	struct nf_hook_ops *ops;
1234 	int ret;
1235 
1236 	ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
1237 	if (ops == NULL)
1238 		return ERR_PTR(-ENOMEM);
1239 
1240 	for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
1241 	     hook_mask >>= 1, ++hooknum) {
1242 		if (!(hook_mask & 1))
1243 			continue;
1244 		ops[i].hook     = fn;
1245 		ops[i].owner    = table->me;
1246 		ops[i].pf       = table->af;
1247 		ops[i].hooknum  = hooknum;
1248 		ops[i].priority = table->priority;
1249 		++i;
1250 	}
1251 
1252 	ret = nf_register_hooks(ops, num_hooks);
1253 	if (ret < 0) {
1254 		kfree(ops);
1255 		return ERR_PTR(ret);
1256 	}
1257 
1258 	return ops;
1259 }
1260 EXPORT_SYMBOL_GPL(xt_hook_link);
1261 
1262 /**
1263  * xt_hook_unlink - remove hooks for a table
1264  * @ops:	nf_hook_ops array as returned by nf_hook_link
1265  * @hook_mask:	the very same mask that was passed to nf_hook_link
1266  */
xt_hook_unlink(const struct xt_table * table,struct nf_hook_ops * ops)1267 void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
1268 {
1269 	nf_unregister_hooks(ops, hweight32(table->valid_hooks));
1270 	kfree(ops);
1271 }
1272 EXPORT_SYMBOL_GPL(xt_hook_unlink);
1273 
xt_proto_init(struct net * net,u_int8_t af)1274 int xt_proto_init(struct net *net, u_int8_t af)
1275 {
1276 #ifdef CONFIG_PROC_FS
1277 	char buf[XT_FUNCTION_MAXNAMELEN];
1278 	struct proc_dir_entry *proc;
1279 #endif
1280 
1281 	if (af >= ARRAY_SIZE(xt_prefix))
1282 		return -EINVAL;
1283 
1284 
1285 #ifdef CONFIG_PROC_FS
1286 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1287 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
1288 	proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
1289 				(void *)(unsigned long)af);
1290 	if (!proc)
1291 		goto out;
1292 
1293 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1294 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1295 	proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
1296 				(void *)(unsigned long)af);
1297 	if (!proc)
1298 		goto out_remove_tables;
1299 
1300 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1301 	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1302 	proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
1303 				(void *)(unsigned long)af);
1304 	if (!proc)
1305 		goto out_remove_matches;
1306 #endif
1307 
1308 	return 0;
1309 
1310 #ifdef CONFIG_PROC_FS
1311 out_remove_matches:
1312 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1313 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1314 	proc_net_remove(net, buf);
1315 
1316 out_remove_tables:
1317 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1318 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
1319 	proc_net_remove(net, buf);
1320 out:
1321 	return -1;
1322 #endif
1323 }
1324 EXPORT_SYMBOL_GPL(xt_proto_init);
1325 
xt_proto_fini(struct net * net,u_int8_t af)1326 void xt_proto_fini(struct net *net, u_int8_t af)
1327 {
1328 #ifdef CONFIG_PROC_FS
1329 	char buf[XT_FUNCTION_MAXNAMELEN];
1330 
1331 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1332 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
1333 	proc_net_remove(net, buf);
1334 
1335 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1336 	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1337 	proc_net_remove(net, buf);
1338 
1339 	strlcpy(buf, xt_prefix[af], sizeof(buf));
1340 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1341 	proc_net_remove(net, buf);
1342 #endif /*CONFIG_PROC_FS*/
1343 }
1344 EXPORT_SYMBOL_GPL(xt_proto_fini);
1345 
xt_net_init(struct net * net)1346 static int __net_init xt_net_init(struct net *net)
1347 {
1348 	int i;
1349 
1350 	for (i = 0; i < NFPROTO_NUMPROTO; i++)
1351 		INIT_LIST_HEAD(&net->xt.tables[i]);
1352 	return 0;
1353 }
1354 
1355 static struct pernet_operations xt_net_ops = {
1356 	.init = xt_net_init,
1357 };
1358 
xt_init(void)1359 static int __init xt_init(void)
1360 {
1361 	unsigned int i;
1362 	int rv;
1363 
1364 	for_each_possible_cpu(i) {
1365 		seqcount_init(&per_cpu(xt_recseq, i));
1366 	}
1367 
1368 	xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
1369 	if (!xt)
1370 		return -ENOMEM;
1371 
1372 	for (i = 0; i < NFPROTO_NUMPROTO; i++) {
1373 		mutex_init(&xt[i].mutex);
1374 #ifdef CONFIG_COMPAT
1375 		mutex_init(&xt[i].compat_mutex);
1376 		xt[i].compat_tab = NULL;
1377 #endif
1378 		INIT_LIST_HEAD(&xt[i].target);
1379 		INIT_LIST_HEAD(&xt[i].match);
1380 	}
1381 	rv = register_pernet_subsys(&xt_net_ops);
1382 	if (rv < 0)
1383 		kfree(xt);
1384 	return rv;
1385 }
1386 
xt_fini(void)1387 static void __exit xt_fini(void)
1388 {
1389 	unregister_pernet_subsys(&xt_net_ops);
1390 	kfree(xt);
1391 }
1392 
1393 module_init(xt_init);
1394 module_exit(xt_fini);
1395 
1396