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1/*
2 * x_tables core - Backend for {ip,ip6,arp}_tables
3 *
4 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
5 * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
6 *
7 * Based on existing ip_tables code which is
8 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
9 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 */
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/socket.h>
20#include <linux/net.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/string.h>
24#include <linux/vmalloc.h>
25#include <linux/mutex.h>
26#include <linux/mm.h>
27#include <linux/slab.h>
28#include <linux/audit.h>
29#include <linux/user_namespace.h>
30#include <net/net_namespace.h>
31
32#include <linux/netfilter/x_tables.h>
33#include <linux/netfilter_arp.h>
34#include <linux/netfilter_ipv4/ip_tables.h>
35#include <linux/netfilter_ipv6/ip6_tables.h>
36#include <linux/netfilter_arp/arp_tables.h>
37
38MODULE_LICENSE("GPL");
39MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
40MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
41
42#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
43#define XT_PCPU_BLOCK_SIZE 4096
44
45struct compat_delta {
46 unsigned int offset; /* offset in kernel */
47 int delta; /* delta in 32bit user land */
48};
49
50struct xt_af {
51 struct mutex mutex;
52 struct list_head match;
53 struct list_head target;
54#ifdef CONFIG_COMPAT
55 struct mutex compat_mutex;
56 struct compat_delta *compat_tab;
57 unsigned int number; /* number of slots in compat_tab[] */
58 unsigned int cur; /* number of used slots in compat_tab[] */
59#endif
60};
61
62static struct xt_af *xt;
63
64static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
65 [NFPROTO_UNSPEC] = "x",
66 [NFPROTO_IPV4] = "ip",
67 [NFPROTO_ARP] = "arp",
68 [NFPROTO_BRIDGE] = "eb",
69 [NFPROTO_IPV6] = "ip6",
70};
71
72/* Registration hooks for targets. */
73int xt_register_target(struct xt_target *target)
74{
75 u_int8_t af = target->family;
76
77 mutex_lock(&xt[af].mutex);
78 list_add(&target->list, &xt[af].target);
79 mutex_unlock(&xt[af].mutex);
80 return 0;
81}
82EXPORT_SYMBOL(xt_register_target);
83
84void
85xt_unregister_target(struct xt_target *target)
86{
87 u_int8_t af = target->family;
88
89 mutex_lock(&xt[af].mutex);
90 list_del(&target->list);
91 mutex_unlock(&xt[af].mutex);
92}
93EXPORT_SYMBOL(xt_unregister_target);
94
95int
96xt_register_targets(struct xt_target *target, unsigned int n)
97{
98 unsigned int i;
99 int err = 0;
100
101 for (i = 0; i < n; i++) {
102 err = xt_register_target(&target[i]);
103 if (err)
104 goto err;
105 }
106 return err;
107
108err:
109 if (i > 0)
110 xt_unregister_targets(target, i);
111 return err;
112}
113EXPORT_SYMBOL(xt_register_targets);
114
115void
116xt_unregister_targets(struct xt_target *target, unsigned int n)
117{
118 while (n-- > 0)
119 xt_unregister_target(&target[n]);
120}
121EXPORT_SYMBOL(xt_unregister_targets);
122
123int xt_register_match(struct xt_match *match)
124{
125 u_int8_t af = match->family;
126
127 mutex_lock(&xt[af].mutex);
128 list_add(&match->list, &xt[af].match);
129 mutex_unlock(&xt[af].mutex);
130 return 0;
131}
132EXPORT_SYMBOL(xt_register_match);
133
134void
135xt_unregister_match(struct xt_match *match)
136{
137 u_int8_t af = match->family;
138
139 mutex_lock(&xt[af].mutex);
140 list_del(&match->list);
141 mutex_unlock(&xt[af].mutex);
142}
143EXPORT_SYMBOL(xt_unregister_match);
144
145int
146xt_register_matches(struct xt_match *match, unsigned int n)
147{
148 unsigned int i;
149 int err = 0;
150
151 for (i = 0; i < n; i++) {
152 err = xt_register_match(&match[i]);
153 if (err)
154 goto err;
155 }
156 return err;
157
158err:
159 if (i > 0)
160 xt_unregister_matches(match, i);
161 return err;
162}
163EXPORT_SYMBOL(xt_register_matches);
164
165void
166xt_unregister_matches(struct xt_match *match, unsigned int n)
167{
168 while (n-- > 0)
169 xt_unregister_match(&match[n]);
170}
171EXPORT_SYMBOL(xt_unregister_matches);
172
173
174/*
175 * These are weird, but module loading must not be done with mutex
176 * held (since they will register), and we have to have a single
177 * function to use.
178 */
179
180/* Find match, grabs ref. Returns ERR_PTR() on error. */
181struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
182{
183 struct xt_match *m;
184 int err = -ENOENT;
185
186 mutex_lock(&xt[af].mutex);
187 list_for_each_entry(m, &xt[af].match, list) {
188 if (strcmp(m->name, name) == 0) {
189 if (m->revision == revision) {
190 if (try_module_get(m->me)) {
191 mutex_unlock(&xt[af].mutex);
192 return m;
193 }
194 } else
195 err = -EPROTOTYPE; /* Found something. */
196 }
197 }
198 mutex_unlock(&xt[af].mutex);
199
200 if (af != NFPROTO_UNSPEC)
201 /* Try searching again in the family-independent list */
202 return xt_find_match(NFPROTO_UNSPEC, name, revision);
203
204 return ERR_PTR(err);
205}
206EXPORT_SYMBOL(xt_find_match);
207
208struct xt_match *
209xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
210{
211 struct xt_match *match;
212
213 match = xt_find_match(nfproto, name, revision);
214 if (IS_ERR(match)) {
215 request_module("%st_%s", xt_prefix[nfproto], name);
216 match = xt_find_match(nfproto, name, revision);
217 }
218
219 return match;
220}
221EXPORT_SYMBOL_GPL(xt_request_find_match);
222
223/* Find target, grabs ref. Returns ERR_PTR() on error. */
224struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
225{
226 struct xt_target *t;
227 int err = -ENOENT;
228
229 mutex_lock(&xt[af].mutex);
230 list_for_each_entry(t, &xt[af].target, list) {
231 if (strcmp(t->name, name) == 0) {
232 if (t->revision == revision) {
233 if (try_module_get(t->me)) {
234 mutex_unlock(&xt[af].mutex);
235 return t;
236 }
237 } else
238 err = -EPROTOTYPE; /* Found something. */
239 }
240 }
241 mutex_unlock(&xt[af].mutex);
242
243 if (af != NFPROTO_UNSPEC)
244 /* Try searching again in the family-independent list */
245 return xt_find_target(NFPROTO_UNSPEC, name, revision);
246
247 return ERR_PTR(err);
248}
249EXPORT_SYMBOL(xt_find_target);
250
251struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
252{
253 struct xt_target *target;
254
255 target = xt_find_target(af, name, revision);
256 if (IS_ERR(target)) {
257 request_module("%st_%s", xt_prefix[af], name);
258 target = xt_find_target(af, name, revision);
259 }
260
261 return target;
262}
263EXPORT_SYMBOL_GPL(xt_request_find_target);
264
265static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
266{
267 const struct xt_match *m;
268 int have_rev = 0;
269
270 list_for_each_entry(m, &xt[af].match, list) {
271 if (strcmp(m->name, name) == 0) {
272 if (m->revision > *bestp)
273 *bestp = m->revision;
274 if (m->revision == revision)
275 have_rev = 1;
276 }
277 }
278
279 if (af != NFPROTO_UNSPEC && !have_rev)
280 return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
281
282 return have_rev;
283}
284
285static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
286{
287 const struct xt_target *t;
288 int have_rev = 0;
289
290 list_for_each_entry(t, &xt[af].target, list) {
291 if (strcmp(t->name, name) == 0) {
292 if (t->revision > *bestp)
293 *bestp = t->revision;
294 if (t->revision == revision)
295 have_rev = 1;
296 }
297 }
298
299 if (af != NFPROTO_UNSPEC && !have_rev)
300 return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
301
302 return have_rev;
303}
304
305/* Returns true or false (if no such extension at all) */
306int xt_find_revision(u8 af, const char *name, u8 revision, int target,
307 int *err)
308{
309 int have_rev, best = -1;
310
311 mutex_lock(&xt[af].mutex);
312 if (target == 1)
313 have_rev = target_revfn(af, name, revision, &best);
314 else
315 have_rev = match_revfn(af, name, revision, &best);
316 mutex_unlock(&xt[af].mutex);
317
318 /* Nothing at all? Return 0 to try loading module. */
319 if (best == -1) {
320 *err = -ENOENT;
321 return 0;
322 }
323
324 *err = best;
325 if (!have_rev)
326 *err = -EPROTONOSUPPORT;
327 return 1;
328}
329EXPORT_SYMBOL_GPL(xt_find_revision);
330
331static char *
332textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
333{
334 static const char *const inetbr_names[] = {
335 "PREROUTING", "INPUT", "FORWARD",
336 "OUTPUT", "POSTROUTING", "BROUTING",
337 };
338 static const char *const arp_names[] = {
339 "INPUT", "FORWARD", "OUTPUT",
340 };
341 const char *const *names;
342 unsigned int i, max;
343 char *p = buf;
344 bool np = false;
345 int res;
346
347 names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
348 max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
349 ARRAY_SIZE(inetbr_names);
350 *p = '\0';
351 for (i = 0; i < max; ++i) {
352 if (!(mask & (1 << i)))
353 continue;
354 res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
355 if (res > 0) {
356 size -= res;
357 p += res;
358 }
359 np = true;
360 }
361
362 return buf;
363}
364
365int xt_check_match(struct xt_mtchk_param *par,
366 unsigned int size, u_int8_t proto, bool inv_proto)
367{
368 int ret;
369
370 if (XT_ALIGN(par->match->matchsize) != size &&
371 par->match->matchsize != -1) {
372 /*
373 * ebt_among is exempt from centralized matchsize checking
374 * because it uses a dynamic-size data set.
375 */
376 pr_err("%s_tables: %s.%u match: invalid size "
377 "%u (kernel) != (user) %u\n",
378 xt_prefix[par->family], par->match->name,
379 par->match->revision,
380 XT_ALIGN(par->match->matchsize), size);
381 return -EINVAL;
382 }
383 if (par->match->table != NULL &&
384 strcmp(par->match->table, par->table) != 0) {
385 pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
386 xt_prefix[par->family], par->match->name,
387 par->match->table, par->table);
388 return -EINVAL;
389 }
390 if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
391 char used[64], allow[64];
392
393 pr_err("%s_tables: %s match: used from hooks %s, but only "
394 "valid from %s\n",
395 xt_prefix[par->family], par->match->name,
396 textify_hooks(used, sizeof(used), par->hook_mask,
397 par->family),
398 textify_hooks(allow, sizeof(allow), par->match->hooks,
399 par->family));
400 return -EINVAL;
401 }
402 if (par->match->proto && (par->match->proto != proto || inv_proto)) {
403 pr_err("%s_tables: %s match: only valid for protocol %u\n",
404 xt_prefix[par->family], par->match->name,
405 par->match->proto);
406 return -EINVAL;
407 }
408 if (par->match->checkentry != NULL) {
409 ret = par->match->checkentry(par);
410 if (ret < 0)
411 return ret;
412 else if (ret > 0)
413 /* Flag up potential errors. */
414 return -EIO;
415 }
416 return 0;
417}
418EXPORT_SYMBOL_GPL(xt_check_match);
419
420/** xt_check_entry_match - check that matches end before start of target
421 *
422 * @match: beginning of xt_entry_match
423 * @target: beginning of this rules target (alleged end of matches)
424 * @alignment: alignment requirement of match structures
425 *
426 * Validates that all matches add up to the beginning of the target,
427 * and that each match covers at least the base structure size.
428 *
429 * Return: 0 on success, negative errno on failure.
430 */
431static int xt_check_entry_match(const char *match, const char *target,
432 const size_t alignment)
433{
434 const struct xt_entry_match *pos;
435 int length = target - match;
436
437 if (length == 0) /* no matches */
438 return 0;
439
440 pos = (struct xt_entry_match *)match;
441 do {
442 if ((unsigned long)pos % alignment)
443 return -EINVAL;
444
445 if (length < (int)sizeof(struct xt_entry_match))
446 return -EINVAL;
447
448 if (pos->u.match_size < sizeof(struct xt_entry_match))
449 return -EINVAL;
450
451 if (pos->u.match_size > length)
452 return -EINVAL;
453
454 length -= pos->u.match_size;
455 pos = ((void *)((char *)(pos) + (pos)->u.match_size));
456 } while (length > 0);
457
458 return 0;
459}
460
461#ifdef CONFIG_COMPAT
462int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
463{
464 struct xt_af *xp = &xt[af];
465
466 if (!xp->compat_tab) {
467 if (!xp->number)
468 return -EINVAL;
469 xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
470 if (!xp->compat_tab)
471 return -ENOMEM;
472 xp->cur = 0;
473 }
474
475 if (xp->cur >= xp->number)
476 return -EINVAL;
477
478 if (xp->cur)
479 delta += xp->compat_tab[xp->cur - 1].delta;
480 xp->compat_tab[xp->cur].offset = offset;
481 xp->compat_tab[xp->cur].delta = delta;
482 xp->cur++;
483 return 0;
484}
485EXPORT_SYMBOL_GPL(xt_compat_add_offset);
486
487void xt_compat_flush_offsets(u_int8_t af)
488{
489 if (xt[af].compat_tab) {
490 vfree(xt[af].compat_tab);
491 xt[af].compat_tab = NULL;
492 xt[af].number = 0;
493 xt[af].cur = 0;
494 }
495}
496EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
497
498int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
499{
500 struct compat_delta *tmp = xt[af].compat_tab;
501 int mid, left = 0, right = xt[af].cur - 1;
502
503 while (left <= right) {
504 mid = (left + right) >> 1;
505 if (offset > tmp[mid].offset)
506 left = mid + 1;
507 else if (offset < tmp[mid].offset)
508 right = mid - 1;
509 else
510 return mid ? tmp[mid - 1].delta : 0;
511 }
512 return left ? tmp[left - 1].delta : 0;
513}
514EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
515
516void xt_compat_init_offsets(u_int8_t af, unsigned int number)
517{
518 xt[af].number = number;
519 xt[af].cur = 0;
520}
521EXPORT_SYMBOL(xt_compat_init_offsets);
522
523int xt_compat_match_offset(const struct xt_match *match)
524{
525 u_int16_t csize = match->compatsize ? : match->matchsize;
526 return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
527}
528EXPORT_SYMBOL_GPL(xt_compat_match_offset);
529
530void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
531 unsigned int *size)
532{
533 const struct xt_match *match = m->u.kernel.match;
534 struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
535 int pad, off = xt_compat_match_offset(match);
536 u_int16_t msize = cm->u.user.match_size;
537 char name[sizeof(m->u.user.name)];
538
539 m = *dstptr;
540 memcpy(m, cm, sizeof(*cm));
541 if (match->compat_from_user)
542 match->compat_from_user(m->data, cm->data);
543 else
544 memcpy(m->data, cm->data, msize - sizeof(*cm));
545 pad = XT_ALIGN(match->matchsize) - match->matchsize;
546 if (pad > 0)
547 memset(m->data + match->matchsize, 0, pad);
548
549 msize += off;
550 m->u.user.match_size = msize;
551 strlcpy(name, match->name, sizeof(name));
552 module_put(match->me);
553 strncpy(m->u.user.name, name, sizeof(m->u.user.name));
554
555 *size += off;
556 *dstptr += msize;
557}
558EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
559
560int xt_compat_match_to_user(const struct xt_entry_match *m,
561 void __user **dstptr, unsigned int *size)
562{
563 const struct xt_match *match = m->u.kernel.match;
564 struct compat_xt_entry_match __user *cm = *dstptr;
565 int off = xt_compat_match_offset(match);
566 u_int16_t msize = m->u.user.match_size - off;
567
568 if (copy_to_user(cm, m, sizeof(*cm)) ||
569 put_user(msize, &cm->u.user.match_size) ||
570 copy_to_user(cm->u.user.name, m->u.kernel.match->name,
571 strlen(m->u.kernel.match->name) + 1))
572 return -EFAULT;
573
574 if (match->compat_to_user) {
575 if (match->compat_to_user((void __user *)cm->data, m->data))
576 return -EFAULT;
577 } else {
578 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
579 return -EFAULT;
580 }
581
582 *size -= off;
583 *dstptr += msize;
584 return 0;
585}
586EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
587
588/* non-compat version may have padding after verdict */
589struct compat_xt_standard_target {
590 struct compat_xt_entry_target t;
591 compat_uint_t verdict;
592};
593
594int xt_compat_check_entry_offsets(const void *base, const char *elems,
595 unsigned int target_offset,
596 unsigned int next_offset)
597{
598 long size_of_base_struct = elems - (const char *)base;
599 const struct compat_xt_entry_target *t;
600 const char *e = base;
601
602 if (target_offset < size_of_base_struct)
603 return -EINVAL;
604
605 if (target_offset + sizeof(*t) > next_offset)
606 return -EINVAL;
607
608 t = (void *)(e + target_offset);
609 if (t->u.target_size < sizeof(*t))
610 return -EINVAL;
611
612 if (target_offset + t->u.target_size > next_offset)
613 return -EINVAL;
614
615 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
616 COMPAT_XT_ALIGN(target_offset + sizeof(struct compat_xt_standard_target)) != next_offset)
617 return -EINVAL;
618
619 /* compat_xt_entry match has less strict aligment requirements,
620 * otherwise they are identical. In case of padding differences
621 * we need to add compat version of xt_check_entry_match.
622 */
623 BUILD_BUG_ON(sizeof(struct compat_xt_entry_match) != sizeof(struct xt_entry_match));
624
625 return xt_check_entry_match(elems, base + target_offset,
626 __alignof__(struct compat_xt_entry_match));
627}
628EXPORT_SYMBOL(xt_compat_check_entry_offsets);
629#endif /* CONFIG_COMPAT */
630
631/**
632 * xt_check_entry_offsets - validate arp/ip/ip6t_entry
633 *
634 * @base: pointer to arp/ip/ip6t_entry
635 * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems
636 * @target_offset: the arp/ip/ip6_t->target_offset
637 * @next_offset: the arp/ip/ip6_t->next_offset
638 *
639 * validates that target_offset and next_offset are sane and that all
640 * match sizes (if any) align with the target offset.
641 *
642 * This function does not validate the targets or matches themselves, it
643 * only tests that all the offsets and sizes are correct, that all
644 * match structures are aligned, and that the last structure ends where
645 * the target structure begins.
646 *
647 * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
648 *
649 * The arp/ip/ip6t_entry structure @base must have passed following tests:
650 * - it must point to a valid memory location
651 * - base to base + next_offset must be accessible, i.e. not exceed allocated
652 * length.
653 *
654 * A well-formed entry looks like this:
655 *
656 * ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry
657 * e->elems[]-----' | |
658 * matchsize | |
659 * matchsize | |
660 * | |
661 * target_offset---------------------------------' |
662 * next_offset---------------------------------------------------'
663 *
664 * elems[]: flexible array member at end of ip(6)/arpt_entry struct.
665 * This is where matches (if any) and the target reside.
666 * target_offset: beginning of target.
667 * next_offset: start of the next rule; also: size of this rule.
668 * Since targets have a minimum size, target_offset + minlen <= next_offset.
669 *
670 * Every match stores its size, sum of sizes must not exceed target_offset.
671 *
672 * Return: 0 on success, negative errno on failure.
673 */
674int xt_check_entry_offsets(const void *base,
675 const char *elems,
676 unsigned int target_offset,
677 unsigned int next_offset)
678{
679 long size_of_base_struct = elems - (const char *)base;
680 const struct xt_entry_target *t;
681 const char *e = base;
682
683 /* target start is within the ip/ip6/arpt_entry struct */
684 if (target_offset < size_of_base_struct)
685 return -EINVAL;
686
687 if (target_offset + sizeof(*t) > next_offset)
688 return -EINVAL;
689
690 t = (void *)(e + target_offset);
691 if (t->u.target_size < sizeof(*t))
692 return -EINVAL;
693
694 if (target_offset + t->u.target_size > next_offset)
695 return -EINVAL;
696
697 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
698 XT_ALIGN(target_offset + sizeof(struct xt_standard_target)) != next_offset)
699 return -EINVAL;
700
701 return xt_check_entry_match(elems, base + target_offset,
702 __alignof__(struct xt_entry_match));
703}
704EXPORT_SYMBOL(xt_check_entry_offsets);
705
706/**
707 * xt_alloc_entry_offsets - allocate array to store rule head offsets
708 *
709 * @size: number of entries
710 *
711 * Return: NULL or kmalloc'd or vmalloc'd array
712 */
713unsigned int *xt_alloc_entry_offsets(unsigned int size)
714{
715 unsigned int *off;
716
717 off = kcalloc(size, sizeof(unsigned int), GFP_KERNEL | __GFP_NOWARN);
718
719 if (off)
720 return off;
721
722 if (size < (SIZE_MAX / sizeof(unsigned int)))
723 off = vmalloc(size * sizeof(unsigned int));
724
725 return off;
726}
727EXPORT_SYMBOL(xt_alloc_entry_offsets);
728
729/**
730 * xt_find_jump_offset - check if target is a valid jump offset
731 *
732 * @offsets: array containing all valid rule start offsets of a rule blob
733 * @target: the jump target to search for
734 * @size: entries in @offset
735 */
736bool xt_find_jump_offset(const unsigned int *offsets,
737 unsigned int target, unsigned int size)
738{
739 int m, low = 0, hi = size;
740
741 while (hi > low) {
742 m = (low + hi) / 2u;
743
744 if (offsets[m] > target)
745 hi = m;
746 else if (offsets[m] < target)
747 low = m + 1;
748 else
749 return true;
750 }
751
752 return false;
753}
754EXPORT_SYMBOL(xt_find_jump_offset);
755
756int xt_check_target(struct xt_tgchk_param *par,
757 unsigned int size, u_int8_t proto, bool inv_proto)
758{
759 int ret;
760
761 if (XT_ALIGN(par->target->targetsize) != size) {
762 pr_err("%s_tables: %s.%u target: invalid size "
763 "%u (kernel) != (user) %u\n",
764 xt_prefix[par->family], par->target->name,
765 par->target->revision,
766 XT_ALIGN(par->target->targetsize), size);
767 return -EINVAL;
768 }
769 if (par->target->table != NULL &&
770 strcmp(par->target->table, par->table) != 0) {
771 pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
772 xt_prefix[par->family], par->target->name,
773 par->target->table, par->table);
774 return -EINVAL;
775 }
776 if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
777 char used[64], allow[64];
778
779 pr_err("%s_tables: %s target: used from hooks %s, but only "
780 "usable from %s\n",
781 xt_prefix[par->family], par->target->name,
782 textify_hooks(used, sizeof(used), par->hook_mask,
783 par->family),
784 textify_hooks(allow, sizeof(allow), par->target->hooks,
785 par->family));
786 return -EINVAL;
787 }
788 if (par->target->proto && (par->target->proto != proto || inv_proto)) {
789 pr_err("%s_tables: %s target: only valid for protocol %u\n",
790 xt_prefix[par->family], par->target->name,
791 par->target->proto);
792 return -EINVAL;
793 }
794 if (par->target->checkentry != NULL) {
795 ret = par->target->checkentry(par);
796 if (ret < 0)
797 return ret;
798 else if (ret > 0)
799 /* Flag up potential errors. */
800 return -EIO;
801 }
802 return 0;
803}
804EXPORT_SYMBOL_GPL(xt_check_target);
805
806/**
807 * xt_copy_counters_from_user - copy counters and metadata from userspace
808 *
809 * @user: src pointer to userspace memory
810 * @len: alleged size of userspace memory
811 * @info: where to store the xt_counters_info metadata
812 * @compat: true if we setsockopt call is done by 32bit task on 64bit kernel
813 *
814 * Copies counter meta data from @user and stores it in @info.
815 *
816 * vmallocs memory to hold the counters, then copies the counter data
817 * from @user to the new memory and returns a pointer to it.
818 *
819 * If @compat is true, @info gets converted automatically to the 64bit
820 * representation.
821 *
822 * The metadata associated with the counters is stored in @info.
823 *
824 * Return: returns pointer that caller has to test via IS_ERR().
825 * If IS_ERR is false, caller has to vfree the pointer.
826 */
827void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
828 struct xt_counters_info *info, bool compat)
829{
830 void *mem;
831 u64 size;
832
833#ifdef CONFIG_COMPAT
834 if (compat) {
835 /* structures only differ in size due to alignment */
836 struct compat_xt_counters_info compat_tmp;
837
838 if (len <= sizeof(compat_tmp))
839 return ERR_PTR(-EINVAL);
840
841 len -= sizeof(compat_tmp);
842 if (copy_from_user(&compat_tmp, user, sizeof(compat_tmp)) != 0)
843 return ERR_PTR(-EFAULT);
844
845 strlcpy(info->name, compat_tmp.name, sizeof(info->name));
846 info->num_counters = compat_tmp.num_counters;
847 user += sizeof(compat_tmp);
848 } else
849#endif
850 {
851 if (len <= sizeof(*info))
852 return ERR_PTR(-EINVAL);
853
854 len -= sizeof(*info);
855 if (copy_from_user(info, user, sizeof(*info)) != 0)
856 return ERR_PTR(-EFAULT);
857
858 info->name[sizeof(info->name) - 1] = '\0';
859 user += sizeof(*info);
860 }
861
862 size = sizeof(struct xt_counters);
863 size *= info->num_counters;
864
865 if (size != (u64)len)
866 return ERR_PTR(-EINVAL);
867
868 mem = vmalloc(len);
869 if (!mem)
870 return ERR_PTR(-ENOMEM);
871
872 if (copy_from_user(mem, user, len) == 0)
873 return mem;
874
875 vfree(mem);
876 return ERR_PTR(-EFAULT);
877}
878EXPORT_SYMBOL_GPL(xt_copy_counters_from_user);
879
880#ifdef CONFIG_COMPAT
881int xt_compat_target_offset(const struct xt_target *target)
882{
883 u_int16_t csize = target->compatsize ? : target->targetsize;
884 return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
885}
886EXPORT_SYMBOL_GPL(xt_compat_target_offset);
887
888void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
889 unsigned int *size)
890{
891 const struct xt_target *target = t->u.kernel.target;
892 struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
893 int pad, off = xt_compat_target_offset(target);
894 u_int16_t tsize = ct->u.user.target_size;
895 char name[sizeof(t->u.user.name)];
896
897 t = *dstptr;
898 memcpy(t, ct, sizeof(*ct));
899 if (target->compat_from_user)
900 target->compat_from_user(t->data, ct->data);
901 else
902 memcpy(t->data, ct->data, tsize - sizeof(*ct));
903 pad = XT_ALIGN(target->targetsize) - target->targetsize;
904 if (pad > 0)
905 memset(t->data + target->targetsize, 0, pad);
906
907 tsize += off;
908 t->u.user.target_size = tsize;
909 strlcpy(name, target->name, sizeof(name));
910 module_put(target->me);
911 strncpy(t->u.user.name, name, sizeof(t->u.user.name));
912
913 *size += off;
914 *dstptr += tsize;
915}
916EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
917
918int xt_compat_target_to_user(const struct xt_entry_target *t,
919 void __user **dstptr, unsigned int *size)
920{
921 const struct xt_target *target = t->u.kernel.target;
922 struct compat_xt_entry_target __user *ct = *dstptr;
923 int off = xt_compat_target_offset(target);
924 u_int16_t tsize = t->u.user.target_size - off;
925
926 if (copy_to_user(ct, t, sizeof(*ct)) ||
927 put_user(tsize, &ct->u.user.target_size) ||
928 copy_to_user(ct->u.user.name, t->u.kernel.target->name,
929 strlen(t->u.kernel.target->name) + 1))
930 return -EFAULT;
931
932 if (target->compat_to_user) {
933 if (target->compat_to_user((void __user *)ct->data, t->data))
934 return -EFAULT;
935 } else {
936 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
937 return -EFAULT;
938 }
939
940 *size -= off;
941 *dstptr += tsize;
942 return 0;
943}
944EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
945#endif
946
947struct xt_table_info *xt_alloc_table_info(unsigned int size)
948{
949 struct xt_table_info *info = NULL;
950 size_t sz = sizeof(*info) + size;
951
952 if (sz < sizeof(*info))
953 return NULL;
954
955 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
956 if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
957 return NULL;
958
959 if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
960 info = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
961 if (!info) {
962 info = __vmalloc(sz, GFP_KERNEL | __GFP_NOWARN |
963 __GFP_NORETRY | __GFP_HIGHMEM,
964 PAGE_KERNEL);
965 if (!info)
966 return NULL;
967 }
968 memset(info, 0, sizeof(*info));
969 info->size = size;
970 return info;
971}
972EXPORT_SYMBOL(xt_alloc_table_info);
973
974void xt_free_table_info(struct xt_table_info *info)
975{
976 int cpu;
977
978 if (info->jumpstack != NULL) {
979 for_each_possible_cpu(cpu)
980 kvfree(info->jumpstack[cpu]);
981 kvfree(info->jumpstack);
982 }
983
984 kvfree(info);
985}
986EXPORT_SYMBOL(xt_free_table_info);
987
988/* Find table by name, grabs mutex & ref. Returns NULL on error. */
989struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
990 const char *name)
991{
992 struct xt_table *t, *found = NULL;
993
994 mutex_lock(&xt[af].mutex);
995 list_for_each_entry(t, &net->xt.tables[af], list)
996 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
997 return t;
998
999 if (net == &init_net)
1000 goto out;
1001
1002 /* Table doesn't exist in this netns, re-try init */
1003 list_for_each_entry(t, &init_net.xt.tables[af], list) {
1004 if (strcmp(t->name, name))
1005 continue;
1006 if (!try_module_get(t->me))
1007 return NULL;
1008
1009 mutex_unlock(&xt[af].mutex);
1010 if (t->table_init(net) != 0) {
1011 module_put(t->me);
1012 return NULL;
1013 }
1014
1015 found = t;
1016
1017 mutex_lock(&xt[af].mutex);
1018 break;
1019 }
1020
1021 if (!found)
1022 goto out;
1023
1024 /* and once again: */
1025 list_for_each_entry(t, &net->xt.tables[af], list)
1026 if (strcmp(t->name, name) == 0)
1027 return t;
1028
1029 module_put(found->me);
1030 out:
1031 mutex_unlock(&xt[af].mutex);
1032 return NULL;
1033}
1034EXPORT_SYMBOL_GPL(xt_find_table_lock);
1035
1036void xt_table_unlock(struct xt_table *table)
1037{
1038 mutex_unlock(&xt[table->af].mutex);
1039}
1040EXPORT_SYMBOL_GPL(xt_table_unlock);
1041
1042#ifdef CONFIG_COMPAT
1043void xt_compat_lock(u_int8_t af)
1044{
1045 mutex_lock(&xt[af].compat_mutex);
1046}
1047EXPORT_SYMBOL_GPL(xt_compat_lock);
1048
1049void xt_compat_unlock(u_int8_t af)
1050{
1051 mutex_unlock(&xt[af].compat_mutex);
1052}
1053EXPORT_SYMBOL_GPL(xt_compat_unlock);
1054#endif
1055
1056DEFINE_PER_CPU(seqcount_t, xt_recseq);
1057EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
1058
1059struct static_key xt_tee_enabled __read_mostly;
1060EXPORT_SYMBOL_GPL(xt_tee_enabled);
1061
1062static int xt_jumpstack_alloc(struct xt_table_info *i)
1063{
1064 unsigned int size;
1065 int cpu;
1066
1067 size = sizeof(void **) * nr_cpu_ids;
1068 if (size > PAGE_SIZE)
1069 i->jumpstack = vzalloc(size);
1070 else
1071 i->jumpstack = kzalloc(size, GFP_KERNEL);
1072 if (i->jumpstack == NULL)
1073 return -ENOMEM;
1074
1075 /* ruleset without jumps -- no stack needed */
1076 if (i->stacksize == 0)
1077 return 0;
1078
1079 /* Jumpstack needs to be able to record two full callchains, one
1080 * from the first rule set traversal, plus one table reentrancy
1081 * via -j TEE without clobbering the callchain that brought us to
1082 * TEE target.
1083 *
1084 * This is done by allocating two jumpstacks per cpu, on reentry
1085 * the upper half of the stack is used.
1086 *
1087 * see the jumpstack setup in ipt_do_table() for more details.
1088 */
1089 size = sizeof(void *) * i->stacksize * 2u;
1090 for_each_possible_cpu(cpu) {
1091 if (size > PAGE_SIZE)
1092 i->jumpstack[cpu] = vmalloc_node(size,
1093 cpu_to_node(cpu));
1094 else
1095 i->jumpstack[cpu] = kmalloc_node(size,
1096 GFP_KERNEL, cpu_to_node(cpu));
1097 if (i->jumpstack[cpu] == NULL)
1098 /*
1099 * Freeing will be done later on by the callers. The
1100 * chain is: xt_replace_table -> __do_replace ->
1101 * do_replace -> xt_free_table_info.
1102 */
1103 return -ENOMEM;
1104 }
1105
1106 return 0;
1107}
1108
1109struct xt_table_info *
1110xt_replace_table(struct xt_table *table,
1111 unsigned int num_counters,
1112 struct xt_table_info *newinfo,
1113 int *error)
1114{
1115 struct xt_table_info *private;
1116 int ret;
1117
1118 ret = xt_jumpstack_alloc(newinfo);
1119 if (ret < 0) {
1120 *error = ret;
1121 return NULL;
1122 }
1123
1124 /* Do the substitution. */
1125 local_bh_disable();
1126 private = table->private;
1127
1128 /* Check inside lock: is the old number correct? */
1129 if (num_counters != private->number) {
1130 pr_debug("num_counters != table->private->number (%u/%u)\n",
1131 num_counters, private->number);
1132 local_bh_enable();
1133 *error = -EAGAIN;
1134 return NULL;
1135 }
1136
1137 newinfo->initial_entries = private->initial_entries;
1138 /*
1139 * Ensure contents of newinfo are visible before assigning to
1140 * private.
1141 */
1142 smp_wmb();
1143 table->private = newinfo;
1144
1145 /*
1146 * Even though table entries have now been swapped, other CPU's
1147 * may still be using the old entries. This is okay, because
1148 * resynchronization happens because of the locking done
1149 * during the get_counters() routine.
1150 */
1151 local_bh_enable();
1152
1153#ifdef CONFIG_AUDIT
1154 if (audit_enabled) {
1155 struct audit_buffer *ab;
1156
1157 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1158 AUDIT_NETFILTER_CFG);
1159 if (ab) {
1160 audit_log_format(ab, "table=%s family=%u entries=%u",
1161 table->name, table->af,
1162 private->number);
1163 audit_log_end(ab);
1164 }
1165 }
1166#endif
1167
1168 return private;
1169}
1170EXPORT_SYMBOL_GPL(xt_replace_table);
1171
1172struct xt_table *xt_register_table(struct net *net,
1173 const struct xt_table *input_table,
1174 struct xt_table_info *bootstrap,
1175 struct xt_table_info *newinfo)
1176{
1177 int ret;
1178 struct xt_table_info *private;
1179 struct xt_table *t, *table;
1180
1181 /* Don't add one object to multiple lists. */
1182 table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
1183 if (!table) {
1184 ret = -ENOMEM;
1185 goto out;
1186 }
1187
1188 mutex_lock(&xt[table->af].mutex);
1189 /* Don't autoload: we'd eat our tail... */
1190 list_for_each_entry(t, &net->xt.tables[table->af], list) {
1191 if (strcmp(t->name, table->name) == 0) {
1192 ret = -EEXIST;
1193 goto unlock;
1194 }
1195 }
1196
1197 /* Simplifies replace_table code. */
1198 table->private = bootstrap;
1199
1200 if (!xt_replace_table(table, 0, newinfo, &ret))
1201 goto unlock;
1202
1203 private = table->private;
1204 pr_debug("table->private->number = %u\n", private->number);
1205
1206 /* save number of initial entries */
1207 private->initial_entries = private->number;
1208
1209 list_add(&table->list, &net->xt.tables[table->af]);
1210 mutex_unlock(&xt[table->af].mutex);
1211 return table;
1212
1213unlock:
1214 mutex_unlock(&xt[table->af].mutex);
1215 kfree(table);
1216out:
1217 return ERR_PTR(ret);
1218}
1219EXPORT_SYMBOL_GPL(xt_register_table);
1220
1221void *xt_unregister_table(struct xt_table *table)
1222{
1223 struct xt_table_info *private;
1224
1225 mutex_lock(&xt[table->af].mutex);
1226 private = table->private;
1227 list_del(&table->list);
1228 mutex_unlock(&xt[table->af].mutex);
1229 kfree(table);
1230
1231 return private;
1232}
1233EXPORT_SYMBOL_GPL(xt_unregister_table);
1234
1235#ifdef CONFIG_PROC_FS
1236struct xt_names_priv {
1237 struct seq_net_private p;
1238 u_int8_t af;
1239};
1240static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
1241{
1242 struct xt_names_priv *priv = seq->private;
1243 struct net *net = seq_file_net(seq);
1244 u_int8_t af = priv->af;
1245
1246 mutex_lock(&xt[af].mutex);
1247 return seq_list_start(&net->xt.tables[af], *pos);
1248}
1249
1250static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1251{
1252 struct xt_names_priv *priv = seq->private;
1253 struct net *net = seq_file_net(seq);
1254 u_int8_t af = priv->af;
1255
1256 return seq_list_next(v, &net->xt.tables[af], pos);
1257}
1258
1259static void xt_table_seq_stop(struct seq_file *seq, void *v)
1260{
1261 struct xt_names_priv *priv = seq->private;
1262 u_int8_t af = priv->af;
1263
1264 mutex_unlock(&xt[af].mutex);
1265}
1266
1267static int xt_table_seq_show(struct seq_file *seq, void *v)
1268{
1269 struct xt_table *table = list_entry(v, struct xt_table, list);
1270
1271 if (*table->name)
1272 seq_printf(seq, "%s\n", table->name);
1273 return 0;
1274}
1275
1276static const struct seq_operations xt_table_seq_ops = {
1277 .start = xt_table_seq_start,
1278 .next = xt_table_seq_next,
1279 .stop = xt_table_seq_stop,
1280 .show = xt_table_seq_show,
1281};
1282
1283static int xt_table_open(struct inode *inode, struct file *file)
1284{
1285 int ret;
1286 struct xt_names_priv *priv;
1287
1288 ret = seq_open_net(inode, file, &xt_table_seq_ops,
1289 sizeof(struct xt_names_priv));
1290 if (!ret) {
1291 priv = ((struct seq_file *)file->private_data)->private;
1292 priv->af = (unsigned long)PDE_DATA(inode);
1293 }
1294 return ret;
1295}
1296
1297static const struct file_operations xt_table_ops = {
1298 .owner = THIS_MODULE,
1299 .open = xt_table_open,
1300 .read = seq_read,
1301 .llseek = seq_lseek,
1302 .release = seq_release_net,
1303};
1304
1305/*
1306 * Traverse state for ip{,6}_{tables,matches} for helping crossing
1307 * the multi-AF mutexes.
1308 */
1309struct nf_mttg_trav {
1310 struct list_head *head, *curr;
1311 uint8_t class, nfproto;
1312};
1313
1314enum {
1315 MTTG_TRAV_INIT,
1316 MTTG_TRAV_NFP_UNSPEC,
1317 MTTG_TRAV_NFP_SPEC,
1318 MTTG_TRAV_DONE,
1319};
1320
1321static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
1322 bool is_target)
1323{
1324 static const uint8_t next_class[] = {
1325 [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
1326 [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE,
1327 };
1328 struct nf_mttg_trav *trav = seq->private;
1329
1330 switch (trav->class) {
1331 case MTTG_TRAV_INIT:
1332 trav->class = MTTG_TRAV_NFP_UNSPEC;
1333 mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
1334 trav->head = trav->curr = is_target ?
1335 &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
1336 break;
1337 case MTTG_TRAV_NFP_UNSPEC:
1338 trav->curr = trav->curr->next;
1339 if (trav->curr != trav->head)
1340 break;
1341 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1342 mutex_lock(&xt[trav->nfproto].mutex);
1343 trav->head = trav->curr = is_target ?
1344 &xt[trav->nfproto].target : &xt[trav->nfproto].match;
1345 trav->class = next_class[trav->class];
1346 break;
1347 case MTTG_TRAV_NFP_SPEC:
1348 trav->curr = trav->curr->next;
1349 if (trav->curr != trav->head)
1350 break;
1351 /* fallthru, _stop will unlock */
1352 default:
1353 return NULL;
1354 }
1355
1356 if (ppos != NULL)
1357 ++*ppos;
1358 return trav;
1359}
1360
1361static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
1362 bool is_target)
1363{
1364 struct nf_mttg_trav *trav = seq->private;
1365 unsigned int j;
1366
1367 trav->class = MTTG_TRAV_INIT;
1368 for (j = 0; j < *pos; ++j)
1369 if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
1370 return NULL;
1371 return trav;
1372}
1373
1374static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
1375{
1376 struct nf_mttg_trav *trav = seq->private;
1377
1378 switch (trav->class) {
1379 case MTTG_TRAV_NFP_UNSPEC:
1380 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1381 break;
1382 case MTTG_TRAV_NFP_SPEC:
1383 mutex_unlock(&xt[trav->nfproto].mutex);
1384 break;
1385 }
1386}
1387
1388static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1389{
1390 return xt_mttg_seq_start(seq, pos, false);
1391}
1392
1393static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1394{
1395 return xt_mttg_seq_next(seq, v, ppos, false);
1396}
1397
1398static int xt_match_seq_show(struct seq_file *seq, void *v)
1399{
1400 const struct nf_mttg_trav *trav = seq->private;
1401 const struct xt_match *match;
1402
1403 switch (trav->class) {
1404 case MTTG_TRAV_NFP_UNSPEC:
1405 case MTTG_TRAV_NFP_SPEC:
1406 if (trav->curr == trav->head)
1407 return 0;
1408 match = list_entry(trav->curr, struct xt_match, list);
1409 if (*match->name)
1410 seq_printf(seq, "%s\n", match->name);
1411 }
1412 return 0;
1413}
1414
1415static const struct seq_operations xt_match_seq_ops = {
1416 .start = xt_match_seq_start,
1417 .next = xt_match_seq_next,
1418 .stop = xt_mttg_seq_stop,
1419 .show = xt_match_seq_show,
1420};
1421
1422static int xt_match_open(struct inode *inode, struct file *file)
1423{
1424 struct nf_mttg_trav *trav;
1425 trav = __seq_open_private(file, &xt_match_seq_ops, sizeof(*trav));
1426 if (!trav)
1427 return -ENOMEM;
1428
1429 trav->nfproto = (unsigned long)PDE_DATA(inode);
1430 return 0;
1431}
1432
1433static const struct file_operations xt_match_ops = {
1434 .owner = THIS_MODULE,
1435 .open = xt_match_open,
1436 .read = seq_read,
1437 .llseek = seq_lseek,
1438 .release = seq_release_private,
1439};
1440
1441static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1442{
1443 return xt_mttg_seq_start(seq, pos, true);
1444}
1445
1446static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1447{
1448 return xt_mttg_seq_next(seq, v, ppos, true);
1449}
1450
1451static int xt_target_seq_show(struct seq_file *seq, void *v)
1452{
1453 const struct nf_mttg_trav *trav = seq->private;
1454 const struct xt_target *target;
1455
1456 switch (trav->class) {
1457 case MTTG_TRAV_NFP_UNSPEC:
1458 case MTTG_TRAV_NFP_SPEC:
1459 if (trav->curr == trav->head)
1460 return 0;
1461 target = list_entry(trav->curr, struct xt_target, list);
1462 if (*target->name)
1463 seq_printf(seq, "%s\n", target->name);
1464 }
1465 return 0;
1466}
1467
1468static const struct seq_operations xt_target_seq_ops = {
1469 .start = xt_target_seq_start,
1470 .next = xt_target_seq_next,
1471 .stop = xt_mttg_seq_stop,
1472 .show = xt_target_seq_show,
1473};
1474
1475static int xt_target_open(struct inode *inode, struct file *file)
1476{
1477 struct nf_mttg_trav *trav;
1478 trav = __seq_open_private(file, &xt_target_seq_ops, sizeof(*trav));
1479 if (!trav)
1480 return -ENOMEM;
1481
1482 trav->nfproto = (unsigned long)PDE_DATA(inode);
1483 return 0;
1484}
1485
1486static const struct file_operations xt_target_ops = {
1487 .owner = THIS_MODULE,
1488 .open = xt_target_open,
1489 .read = seq_read,
1490 .llseek = seq_lseek,
1491 .release = seq_release_private,
1492};
1493
1494#define FORMAT_TABLES "_tables_names"
1495#define FORMAT_MATCHES "_tables_matches"
1496#define FORMAT_TARGETS "_tables_targets"
1497
1498#endif /* CONFIG_PROC_FS */
1499
1500/**
1501 * xt_hook_ops_alloc - set up hooks for a new table
1502 * @table: table with metadata needed to set up hooks
1503 * @fn: Hook function
1504 *
1505 * This function will create the nf_hook_ops that the x_table needs
1506 * to hand to xt_hook_link_net().
1507 */
1508struct nf_hook_ops *
1509xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn)
1510{
1511 unsigned int hook_mask = table->valid_hooks;
1512 uint8_t i, num_hooks = hweight32(hook_mask);
1513 uint8_t hooknum;
1514 struct nf_hook_ops *ops;
1515
1516 if (!num_hooks)
1517 return ERR_PTR(-EINVAL);
1518
1519 ops = kcalloc(num_hooks, sizeof(*ops), GFP_KERNEL);
1520 if (ops == NULL)
1521 return ERR_PTR(-ENOMEM);
1522
1523 for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
1524 hook_mask >>= 1, ++hooknum) {
1525 if (!(hook_mask & 1))
1526 continue;
1527 ops[i].hook = fn;
1528 ops[i].pf = table->af;
1529 ops[i].hooknum = hooknum;
1530 ops[i].priority = table->priority;
1531 ++i;
1532 }
1533
1534 return ops;
1535}
1536EXPORT_SYMBOL_GPL(xt_hook_ops_alloc);
1537
1538int xt_proto_init(struct net *net, u_int8_t af)
1539{
1540#ifdef CONFIG_PROC_FS
1541 char buf[XT_FUNCTION_MAXNAMELEN];
1542 struct proc_dir_entry *proc;
1543 kuid_t root_uid;
1544 kgid_t root_gid;
1545#endif
1546
1547 if (af >= ARRAY_SIZE(xt_prefix))
1548 return -EINVAL;
1549
1550
1551#ifdef CONFIG_PROC_FS
1552 root_uid = make_kuid(net->user_ns, 0);
1553 root_gid = make_kgid(net->user_ns, 0);
1554
1555 strlcpy(buf, xt_prefix[af], sizeof(buf));
1556 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1557 proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
1558 (void *)(unsigned long)af);
1559 if (!proc)
1560 goto out;
1561 if (uid_valid(root_uid) && gid_valid(root_gid))
1562 proc_set_user(proc, root_uid, root_gid);
1563
1564 strlcpy(buf, xt_prefix[af], sizeof(buf));
1565 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1566 proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
1567 (void *)(unsigned long)af);
1568 if (!proc)
1569 goto out_remove_tables;
1570 if (uid_valid(root_uid) && gid_valid(root_gid))
1571 proc_set_user(proc, root_uid, root_gid);
1572
1573 strlcpy(buf, xt_prefix[af], sizeof(buf));
1574 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1575 proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
1576 (void *)(unsigned long)af);
1577 if (!proc)
1578 goto out_remove_matches;
1579 if (uid_valid(root_uid) && gid_valid(root_gid))
1580 proc_set_user(proc, root_uid, root_gid);
1581#endif
1582
1583 return 0;
1584
1585#ifdef CONFIG_PROC_FS
1586out_remove_matches:
1587 strlcpy(buf, xt_prefix[af], sizeof(buf));
1588 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1589 remove_proc_entry(buf, net->proc_net);
1590
1591out_remove_tables:
1592 strlcpy(buf, xt_prefix[af], sizeof(buf));
1593 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1594 remove_proc_entry(buf, net->proc_net);
1595out:
1596 return -1;
1597#endif
1598}
1599EXPORT_SYMBOL_GPL(xt_proto_init);
1600
1601void xt_proto_fini(struct net *net, u_int8_t af)
1602{
1603#ifdef CONFIG_PROC_FS
1604 char buf[XT_FUNCTION_MAXNAMELEN];
1605
1606 strlcpy(buf, xt_prefix[af], sizeof(buf));
1607 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1608 remove_proc_entry(buf, net->proc_net);
1609
1610 strlcpy(buf, xt_prefix[af], sizeof(buf));
1611 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1612 remove_proc_entry(buf, net->proc_net);
1613
1614 strlcpy(buf, xt_prefix[af], sizeof(buf));
1615 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1616 remove_proc_entry(buf, net->proc_net);
1617#endif /*CONFIG_PROC_FS*/
1618}
1619EXPORT_SYMBOL_GPL(xt_proto_fini);
1620
1621/**
1622 * xt_percpu_counter_alloc - allocate x_tables rule counter
1623 *
1624 * @state: pointer to xt_percpu allocation state
1625 * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
1626 *
1627 * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
1628 * contain the address of the real (percpu) counter.
1629 *
1630 * Rule evaluation needs to use xt_get_this_cpu_counter() helper
1631 * to fetch the real percpu counter.
1632 *
1633 * To speed up allocation and improve data locality, a 4kb block is
1634 * allocated.
1635 *
1636 * xt_percpu_counter_alloc_state contains the base address of the
1637 * allocated page and the current sub-offset.
1638 *
1639 * returns false on error.
1640 */
1641bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
1642 struct xt_counters *counter)
1643{
1644 BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE < (sizeof(*counter) * 2));
1645
1646 if (nr_cpu_ids <= 1)
1647 return true;
1648
1649 if (!state->mem) {
1650 state->mem = __alloc_percpu(XT_PCPU_BLOCK_SIZE,
1651 XT_PCPU_BLOCK_SIZE);
1652 if (!state->mem)
1653 return false;
1654 }
1655 counter->pcnt = (__force unsigned long)(state->mem + state->off);
1656 state->off += sizeof(*counter);
1657 if (state->off > (XT_PCPU_BLOCK_SIZE - sizeof(*counter))) {
1658 state->mem = NULL;
1659 state->off = 0;
1660 }
1661 return true;
1662}
1663EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc);
1664
1665void xt_percpu_counter_free(struct xt_counters *counters)
1666{
1667 unsigned long pcnt = counters->pcnt;
1668
1669 if (nr_cpu_ids > 1 && (pcnt & (XT_PCPU_BLOCK_SIZE - 1)) == 0)
1670 free_percpu((void __percpu *)pcnt);
1671}
1672EXPORT_SYMBOL_GPL(xt_percpu_counter_free);
1673
1674static int __net_init xt_net_init(struct net *net)
1675{
1676 int i;
1677
1678 for (i = 0; i < NFPROTO_NUMPROTO; i++)
1679 INIT_LIST_HEAD(&net->xt.tables[i]);
1680 return 0;
1681}
1682
1683static struct pernet_operations xt_net_ops = {
1684 .init = xt_net_init,
1685};
1686
1687static int __init xt_init(void)
1688{
1689 unsigned int i;
1690 int rv;
1691
1692 for_each_possible_cpu(i) {
1693 seqcount_init(&per_cpu(xt_recseq, i));
1694 }
1695
1696 xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
1697 if (!xt)
1698 return -ENOMEM;
1699
1700 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
1701 mutex_init(&xt[i].mutex);
1702#ifdef CONFIG_COMPAT
1703 mutex_init(&xt[i].compat_mutex);
1704 xt[i].compat_tab = NULL;
1705#endif
1706 INIT_LIST_HEAD(&xt[i].target);
1707 INIT_LIST_HEAD(&xt[i].match);
1708 }
1709 rv = register_pernet_subsys(&xt_net_ops);
1710 if (rv < 0)
1711 kfree(xt);
1712 return rv;
1713}
1714
1715static void __exit xt_fini(void)
1716{
1717 unregister_pernet_subsys(&xt_net_ops);
1718 kfree(xt);
1719}
1720
1721module_init(xt_init);
1722module_exit(xt_fini);
1723
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
36MODULE_LICENSE("GPL");
37MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
38MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
39
40#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
41
42struct compat_delta {
43 unsigned int offset; /* offset in kernel */
44 int delta; /* delta in 32bit user land */
45};
46
47struct 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
59static struct xt_af *xt;
60
61static 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. */
70static const unsigned int xt_jumpstack_multiplier = 2;
71
72/* Registration hooks for targets. */
73int
74xt_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}
86EXPORT_SYMBOL(xt_register_target);
87
88void
89xt_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}
97EXPORT_SYMBOL(xt_unregister_target);
98
99int
100xt_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
112err:
113 if (i > 0)
114 xt_unregister_targets(target, i);
115 return err;
116}
117EXPORT_SYMBOL(xt_register_targets);
118
119void
120xt_unregister_targets(struct xt_target *target, unsigned int n)
121{
122 while (n-- > 0)
123 xt_unregister_target(&target[n]);
124}
125EXPORT_SYMBOL(xt_unregister_targets);
126
127int
128xt_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}
142EXPORT_SYMBOL(xt_register_match);
143
144void
145xt_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}
153EXPORT_SYMBOL(xt_unregister_match);
154
155int
156xt_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
168err:
169 if (i > 0)
170 xt_unregister_matches(match, i);
171 return err;
172}
173EXPORT_SYMBOL(xt_register_matches);
174
175void
176xt_unregister_matches(struct xt_match *match, unsigned int n)
177{
178 while (n-- > 0)
179 xt_unregister_match(&match[n]);
180}
181EXPORT_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. */
191struct 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}
218EXPORT_SYMBOL(xt_find_match);
219
220struct xt_match *
221xt_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}
233EXPORT_SYMBOL_GPL(xt_request_find_match);
234
235/* Find target, grabs ref. Returns ERR_PTR() on error. */
236struct 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}
263EXPORT_SYMBOL(xt_find_target);
264
265struct 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}
277EXPORT_SYMBOL_GPL(xt_request_find_target);
278
279static 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
299static 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) */
320int 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}
346EXPORT_SYMBOL_GPL(xt_find_revision);
347
348static 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
374int 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}
425EXPORT_SYMBOL_GPL(xt_check_match);
426
427#ifdef CONFIG_COMPAT
428int 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}
451EXPORT_SYMBOL_GPL(xt_compat_add_offset);
452
453void 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}
462EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
463
464int 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}
480EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
481
482void xt_compat_init_offsets(u_int8_t af, unsigned int number)
483{
484 xt[af].number = number;
485 xt[af].cur = 0;
486}
487EXPORT_SYMBOL(xt_compat_init_offsets);
488
489int 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}
494EXPORT_SYMBOL_GPL(xt_compat_match_offset);
495
496int 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}
521EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
522
523int 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}
549EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
550#endif /* CONFIG_COMPAT */
551
552int 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}
598EXPORT_SYMBOL_GPL(xt_check_target);
599
600#ifdef CONFIG_COMPAT
601int 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}
606EXPORT_SYMBOL_GPL(xt_compat_target_offset);
607
608void 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}
632EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
633
634int 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}
660EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
661#endif
662
663struct 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}
695EXPORT_SYMBOL(xt_alloc_table_info);
696
697void 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}
727EXPORT_SYMBOL(xt_free_table_info);
728
729/* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
730struct 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}
744EXPORT_SYMBOL_GPL(xt_find_table_lock);
745
746void xt_table_unlock(struct xt_table *table)
747{
748 mutex_unlock(&xt[table->af].mutex);
749}
750EXPORT_SYMBOL_GPL(xt_table_unlock);
751
752#ifdef CONFIG_COMPAT
753void xt_compat_lock(u_int8_t af)
754{
755 mutex_lock(&xt[af].compat_mutex);
756}
757EXPORT_SYMBOL_GPL(xt_compat_lock);
758
759void xt_compat_unlock(u_int8_t af)
760{
761 mutex_unlock(&xt[af].compat_mutex);
762}
763EXPORT_SYMBOL_GPL(xt_compat_unlock);
764#endif
765
766DEFINE_PER_CPU(seqcount_t, xt_recseq);
767EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
768
769static 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
807struct xt_table_info *
808xt_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}
863EXPORT_SYMBOL_GPL(xt_replace_table);
864
865struct 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);
911out_free:
912 kfree(table);
913out:
914 return ERR_PTR(ret);
915}
916EXPORT_SYMBOL_GPL(xt_register_table);
917
918void *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}
930EXPORT_SYMBOL_GPL(xt_unregister_table);
931
932#ifdef CONFIG_PROC_FS
933struct xt_names_priv {
934 struct seq_net_private p;
935 u_int8_t af;
936};
937static 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
947static 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
956static 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
964static 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
974static 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
981static 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
995static 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 */
1007struct nf_mttg_trav {
1008 struct list_head *head, *curr;
1009 uint8_t class, nfproto;
1010};
1011
1012enum {
1013 MTTG_TRAV_INIT,
1014 MTTG_TRAV_NFP_UNSPEC,
1015 MTTG_TRAV_NFP_SPEC,
1016 MTTG_TRAV_DONE,
1017};
1018
1019static 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
1059static 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
1072static 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
1086static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1087{
1088 return xt_mttg_seq_start(seq, pos, false);
1089}
1090
1091static 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
1096static 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
1113static 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
1120static 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
1142static 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
1150static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1151{
1152 return xt_mttg_seq_start(seq, pos, true);
1153}
1154
1155static 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
1160static 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
1177static 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
1184static 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
1206static 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 */
1228struct 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}
1260EXPORT_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 */
1267void 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}
1272EXPORT_SYMBOL_GPL(xt_hook_unlink);
1273
1274int 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
1311out_remove_matches:
1312 strlcpy(buf, xt_prefix[af], sizeof(buf));
1313 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1314 proc_net_remove(net, buf);
1315
1316out_remove_tables:
1317 strlcpy(buf, xt_prefix[af], sizeof(buf));
1318 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1319 proc_net_remove(net, buf);
1320out:
1321 return -1;
1322#endif
1323}
1324EXPORT_SYMBOL_GPL(xt_proto_init);
1325
1326void 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}
1344EXPORT_SYMBOL_GPL(xt_proto_fini);
1345
1346static 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
1355static struct pernet_operations xt_net_ops = {
1356 .init = xt_net_init,
1357};
1358
1359static 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
1387static void __exit xt_fini(void)
1388{
1389 unregister_pernet_subsys(&xt_net_ops);
1390 kfree(xt);
1391}
1392
1393module_init(xt_init);
1394module_exit(xt_fini);
1395