1 // SPDX-License-Identifier: GPL-2.0-only
3 * x_tables core - Backend for {ip,ip6,arp}_tables
5 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
6 * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
8 * Based on existing ip_tables code which is
9 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
10 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/socket.h>
16 #include <linux/net.h>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/string.h>
20 #include <linux/vmalloc.h>
21 #include <linux/mutex.h>
23 #include <linux/slab.h>
24 #include <linux/audit.h>
25 #include <linux/user_namespace.h>
26 #include <net/net_namespace.h>
28 #include <linux/netfilter/x_tables.h>
29 #include <linux/netfilter_arp.h>
30 #include <linux/netfilter_ipv4/ip_tables.h>
31 #include <linux/netfilter_ipv6/ip6_tables.h>
32 #include <linux/netfilter_arp/arp_tables.h>
34 MODULE_LICENSE("GPL");
35 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
36 MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
38 #define XT_PCPU_BLOCK_SIZE 4096
39 #define XT_MAX_TABLE_SIZE (512 * 1024 * 1024)
42 unsigned int offset; /* offset in kernel */
43 int delta; /* delta in 32bit user land */
48 struct list_head match;
49 struct list_head target;
51 struct mutex compat_mutex;
52 struct compat_delta *compat_tab;
53 unsigned int number; /* number of slots in compat_tab[] */
54 unsigned int cur; /* number of used slots in compat_tab[] */
58 static struct xt_af *xt;
60 static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
61 [NFPROTO_UNSPEC] = "x",
62 [NFPROTO_IPV4] = "ip",
63 [NFPROTO_ARP] = "arp",
64 [NFPROTO_BRIDGE] = "eb",
65 [NFPROTO_IPV6] = "ip6",
68 /* Registration hooks for targets. */
69 int xt_register_target(struct xt_target *target)
71 u_int8_t af = target->family;
73 mutex_lock(&xt[af].mutex);
74 list_add(&target->list, &xt[af].target);
75 mutex_unlock(&xt[af].mutex);
78 EXPORT_SYMBOL(xt_register_target);
81 xt_unregister_target(struct xt_target *target)
83 u_int8_t af = target->family;
85 mutex_lock(&xt[af].mutex);
86 list_del(&target->list);
87 mutex_unlock(&xt[af].mutex);
89 EXPORT_SYMBOL(xt_unregister_target);
92 xt_register_targets(struct xt_target *target, unsigned int n)
97 for (i = 0; i < n; i++) {
98 err = xt_register_target(&target[i]);
106 xt_unregister_targets(target, i);
109 EXPORT_SYMBOL(xt_register_targets);
112 xt_unregister_targets(struct xt_target *target, unsigned int n)
115 xt_unregister_target(&target[n]);
117 EXPORT_SYMBOL(xt_unregister_targets);
119 int xt_register_match(struct xt_match *match)
121 u_int8_t af = match->family;
123 mutex_lock(&xt[af].mutex);
124 list_add(&match->list, &xt[af].match);
125 mutex_unlock(&xt[af].mutex);
128 EXPORT_SYMBOL(xt_register_match);
131 xt_unregister_match(struct xt_match *match)
133 u_int8_t af = match->family;
135 mutex_lock(&xt[af].mutex);
136 list_del(&match->list);
137 mutex_unlock(&xt[af].mutex);
139 EXPORT_SYMBOL(xt_unregister_match);
142 xt_register_matches(struct xt_match *match, unsigned int n)
147 for (i = 0; i < n; i++) {
148 err = xt_register_match(&match[i]);
156 xt_unregister_matches(match, i);
159 EXPORT_SYMBOL(xt_register_matches);
162 xt_unregister_matches(struct xt_match *match, unsigned int n)
165 xt_unregister_match(&match[n]);
167 EXPORT_SYMBOL(xt_unregister_matches);
171 * These are weird, but module loading must not be done with mutex
172 * held (since they will register), and we have to have a single
176 /* Find match, grabs ref. Returns ERR_PTR() on error. */
177 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
182 if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
183 return ERR_PTR(-EINVAL);
185 mutex_lock(&xt[af].mutex);
186 list_for_each_entry(m, &xt[af].match, list) {
187 if (strcmp(m->name, name) == 0) {
188 if (m->revision == revision) {
189 if (try_module_get(m->me)) {
190 mutex_unlock(&xt[af].mutex);
194 err = -EPROTOTYPE; /* Found something. */
197 mutex_unlock(&xt[af].mutex);
199 if (af != NFPROTO_UNSPEC)
200 /* Try searching again in the family-independent list */
201 return xt_find_match(NFPROTO_UNSPEC, name, revision);
205 EXPORT_SYMBOL(xt_find_match);
208 xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
210 struct xt_match *match;
212 if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
213 return ERR_PTR(-EINVAL);
215 match = xt_find_match(nfproto, name, revision);
217 request_module("%st_%s", xt_prefix[nfproto], name);
218 match = xt_find_match(nfproto, name, revision);
223 EXPORT_SYMBOL_GPL(xt_request_find_match);
225 /* Find target, grabs ref. Returns ERR_PTR() on error. */
226 static struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
231 if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
232 return ERR_PTR(-EINVAL);
234 mutex_lock(&xt[af].mutex);
235 list_for_each_entry(t, &xt[af].target, list) {
236 if (strcmp(t->name, name) == 0) {
237 if (t->revision == revision) {
238 if (try_module_get(t->me)) {
239 mutex_unlock(&xt[af].mutex);
243 err = -EPROTOTYPE; /* Found something. */
246 mutex_unlock(&xt[af].mutex);
248 if (af != NFPROTO_UNSPEC)
249 /* Try searching again in the family-independent list */
250 return xt_find_target(NFPROTO_UNSPEC, name, revision);
255 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
257 struct xt_target *target;
259 if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
260 return ERR_PTR(-EINVAL);
262 target = xt_find_target(af, name, revision);
263 if (IS_ERR(target)) {
264 request_module("%st_%s", xt_prefix[af], name);
265 target = xt_find_target(af, name, revision);
270 EXPORT_SYMBOL_GPL(xt_request_find_target);
273 static int xt_obj_to_user(u16 __user *psize, u16 size,
274 void __user *pname, const char *name,
275 u8 __user *prev, u8 rev)
277 if (put_user(size, psize))
279 if (copy_to_user(pname, name, strlen(name) + 1))
281 if (put_user(rev, prev))
287 #define XT_OBJ_TO_USER(U, K, TYPE, C_SIZE) \
288 xt_obj_to_user(&U->u.TYPE##_size, C_SIZE ? : K->u.TYPE##_size, \
289 U->u.user.name, K->u.kernel.TYPE->name, \
290 &U->u.user.revision, K->u.kernel.TYPE->revision)
292 int xt_data_to_user(void __user *dst, const void *src,
293 int usersize, int size, int aligned_size)
295 usersize = usersize ? : size;
296 if (copy_to_user(dst, src, usersize))
298 if (usersize != aligned_size &&
299 clear_user(dst + usersize, aligned_size - usersize))
304 EXPORT_SYMBOL_GPL(xt_data_to_user);
306 #define XT_DATA_TO_USER(U, K, TYPE) \
307 xt_data_to_user(U->data, K->data, \
308 K->u.kernel.TYPE->usersize, \
309 K->u.kernel.TYPE->TYPE##size, \
310 XT_ALIGN(K->u.kernel.TYPE->TYPE##size))
312 int xt_match_to_user(const struct xt_entry_match *m,
313 struct xt_entry_match __user *u)
315 return XT_OBJ_TO_USER(u, m, match, 0) ||
316 XT_DATA_TO_USER(u, m, match);
318 EXPORT_SYMBOL_GPL(xt_match_to_user);
320 int xt_target_to_user(const struct xt_entry_target *t,
321 struct xt_entry_target __user *u)
323 return XT_OBJ_TO_USER(u, t, target, 0) ||
324 XT_DATA_TO_USER(u, t, target);
326 EXPORT_SYMBOL_GPL(xt_target_to_user);
328 static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
330 const struct xt_match *m;
333 mutex_lock(&xt[af].mutex);
334 list_for_each_entry(m, &xt[af].match, list) {
335 if (strcmp(m->name, name) == 0) {
336 if (m->revision > *bestp)
337 *bestp = m->revision;
338 if (m->revision == revision)
342 mutex_unlock(&xt[af].mutex);
344 if (af != NFPROTO_UNSPEC && !have_rev)
345 return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
350 static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
352 const struct xt_target *t;
355 mutex_lock(&xt[af].mutex);
356 list_for_each_entry(t, &xt[af].target, list) {
357 if (strcmp(t->name, name) == 0) {
358 if (t->revision > *bestp)
359 *bestp = t->revision;
360 if (t->revision == revision)
364 mutex_unlock(&xt[af].mutex);
366 if (af != NFPROTO_UNSPEC && !have_rev)
367 return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
372 /* Returns true or false (if no such extension at all) */
373 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
376 int have_rev, best = -1;
379 have_rev = target_revfn(af, name, revision, &best);
381 have_rev = match_revfn(af, name, revision, &best);
383 /* Nothing at all? Return 0 to try loading module. */
391 *err = -EPROTONOSUPPORT;
394 EXPORT_SYMBOL_GPL(xt_find_revision);
397 textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
399 static const char *const inetbr_names[] = {
400 "PREROUTING", "INPUT", "FORWARD",
401 "OUTPUT", "POSTROUTING", "BROUTING",
403 static const char *const arp_names[] = {
404 "INPUT", "FORWARD", "OUTPUT",
406 const char *const *names;
412 names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
413 max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
414 ARRAY_SIZE(inetbr_names);
416 for (i = 0; i < max; ++i) {
417 if (!(mask & (1 << i)))
419 res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
431 * xt_check_proc_name - check that name is suitable for /proc file creation
433 * @name: file name candidate
434 * @size: length of buffer
436 * some x_tables modules wish to create a file in /proc.
437 * This function makes sure that the name is suitable for this
438 * purpose, it checks that name is NUL terminated and isn't a 'special'
441 * returns negative number on error or 0 if name is useable.
443 int xt_check_proc_name(const char *name, unsigned int size)
448 if (strnlen(name, size) == size)
449 return -ENAMETOOLONG;
451 if (strcmp(name, ".") == 0 ||
452 strcmp(name, "..") == 0 ||
458 EXPORT_SYMBOL(xt_check_proc_name);
460 int xt_check_match(struct xt_mtchk_param *par,
461 unsigned int size, u16 proto, bool inv_proto)
465 if (XT_ALIGN(par->match->matchsize) != size &&
466 par->match->matchsize != -1) {
468 * ebt_among is exempt from centralized matchsize checking
469 * because it uses a dynamic-size data set.
471 pr_err_ratelimited("%s_tables: %s.%u match: invalid size %u (kernel) != (user) %u\n",
472 xt_prefix[par->family], par->match->name,
473 par->match->revision,
474 XT_ALIGN(par->match->matchsize), size);
477 if (par->match->table != NULL &&
478 strcmp(par->match->table, par->table) != 0) {
479 pr_info_ratelimited("%s_tables: %s match: only valid in %s table, not %s\n",
480 xt_prefix[par->family], par->match->name,
481 par->match->table, par->table);
484 if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
485 char used[64], allow[64];
487 pr_info_ratelimited("%s_tables: %s match: used from hooks %s, but only valid from %s\n",
488 xt_prefix[par->family], par->match->name,
489 textify_hooks(used, sizeof(used),
490 par->hook_mask, par->family),
491 textify_hooks(allow, sizeof(allow),
496 if (par->match->proto && (par->match->proto != proto || inv_proto)) {
497 pr_info_ratelimited("%s_tables: %s match: only valid for protocol %u\n",
498 xt_prefix[par->family], par->match->name,
502 if (par->match->checkentry != NULL) {
503 ret = par->match->checkentry(par);
507 /* Flag up potential errors. */
512 EXPORT_SYMBOL_GPL(xt_check_match);
514 /** xt_check_entry_match - check that matches end before start of target
516 * @match: beginning of xt_entry_match
517 * @target: beginning of this rules target (alleged end of matches)
518 * @alignment: alignment requirement of match structures
520 * Validates that all matches add up to the beginning of the target,
521 * and that each match covers at least the base structure size.
523 * Return: 0 on success, negative errno on failure.
525 static int xt_check_entry_match(const char *match, const char *target,
526 const size_t alignment)
528 const struct xt_entry_match *pos;
529 int length = target - match;
531 if (length == 0) /* no matches */
534 pos = (struct xt_entry_match *)match;
536 if ((unsigned long)pos % alignment)
539 if (length < (int)sizeof(struct xt_entry_match))
542 if (pos->u.match_size < sizeof(struct xt_entry_match))
545 if (pos->u.match_size > length)
548 length -= pos->u.match_size;
549 pos = ((void *)((char *)(pos) + (pos)->u.match_size));
550 } while (length > 0);
555 /** xt_check_table_hooks - check hook entry points are sane
557 * @info xt_table_info to check
558 * @valid_hooks - hook entry points that we can enter from
560 * Validates that the hook entry and underflows points are set up.
562 * Return: 0 on success, negative errno on failure.
564 int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks)
566 const char *err = "unsorted underflow";
567 unsigned int i, max_uflow, max_entry;
568 bool check_hooks = false;
570 BUILD_BUG_ON(ARRAY_SIZE(info->hook_entry) != ARRAY_SIZE(info->underflow));
575 for (i = 0; i < ARRAY_SIZE(info->hook_entry); i++) {
576 if (!(valid_hooks & (1 << i)))
579 if (info->hook_entry[i] == 0xFFFFFFFF)
581 if (info->underflow[i] == 0xFFFFFFFF)
585 if (max_uflow > info->underflow[i])
588 if (max_uflow == info->underflow[i]) {
589 err = "duplicate underflow";
592 if (max_entry > info->hook_entry[i]) {
593 err = "unsorted entry";
596 if (max_entry == info->hook_entry[i]) {
597 err = "duplicate entry";
601 max_entry = info->hook_entry[i];
602 max_uflow = info->underflow[i];
608 pr_err_ratelimited("%s at hook %d\n", err, i);
611 EXPORT_SYMBOL(xt_check_table_hooks);
613 static bool verdict_ok(int verdict)
619 int v = -verdict - 1;
621 if (verdict == XT_RETURN)
625 case NF_ACCEPT: return true;
626 case NF_DROP: return true;
627 case NF_QUEUE: return true;
638 static bool error_tg_ok(unsigned int usersize, unsigned int kernsize,
639 const char *msg, unsigned int msglen)
641 return usersize == kernsize && strnlen(msg, msglen) < msglen;
645 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
647 struct xt_af *xp = &xt[af];
649 WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
651 if (WARN_ON(!xp->compat_tab))
654 if (xp->cur >= xp->number)
658 delta += xp->compat_tab[xp->cur - 1].delta;
659 xp->compat_tab[xp->cur].offset = offset;
660 xp->compat_tab[xp->cur].delta = delta;
664 EXPORT_SYMBOL_GPL(xt_compat_add_offset);
666 void xt_compat_flush_offsets(u_int8_t af)
668 WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
670 if (xt[af].compat_tab) {
671 vfree(xt[af].compat_tab);
672 xt[af].compat_tab = NULL;
677 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
679 int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
681 struct compat_delta *tmp = xt[af].compat_tab;
682 int mid, left = 0, right = xt[af].cur - 1;
684 while (left <= right) {
685 mid = (left + right) >> 1;
686 if (offset > tmp[mid].offset)
688 else if (offset < tmp[mid].offset)
691 return mid ? tmp[mid - 1].delta : 0;
693 return left ? tmp[left - 1].delta : 0;
695 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
697 int xt_compat_init_offsets(u8 af, unsigned int number)
701 WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
703 if (!number || number > (INT_MAX / sizeof(struct compat_delta)))
706 if (WARN_ON(xt[af].compat_tab))
709 mem = sizeof(struct compat_delta) * number;
710 if (mem > XT_MAX_TABLE_SIZE)
713 xt[af].compat_tab = vmalloc(mem);
714 if (!xt[af].compat_tab)
717 xt[af].number = number;
722 EXPORT_SYMBOL(xt_compat_init_offsets);
724 int xt_compat_match_offset(const struct xt_match *match)
726 u_int16_t csize = match->compatsize ? : match->matchsize;
727 return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
729 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
731 void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
734 const struct xt_match *match = m->u.kernel.match;
735 struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
736 int off = xt_compat_match_offset(match);
737 u_int16_t msize = cm->u.user.match_size;
738 char name[sizeof(m->u.user.name)];
741 memcpy(m, cm, sizeof(*cm));
742 if (match->compat_from_user)
743 match->compat_from_user(m->data, cm->data);
745 memcpy(m->data, cm->data, msize - sizeof(*cm));
748 m->u.user.match_size = msize;
749 strlcpy(name, match->name, sizeof(name));
750 module_put(match->me);
751 strncpy(m->u.user.name, name, sizeof(m->u.user.name));
756 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
758 #define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
759 xt_data_to_user(U->data, K->data, \
760 K->u.kernel.TYPE->usersize, \
762 COMPAT_XT_ALIGN(C_SIZE))
764 int xt_compat_match_to_user(const struct xt_entry_match *m,
765 void __user **dstptr, unsigned int *size)
767 const struct xt_match *match = m->u.kernel.match;
768 struct compat_xt_entry_match __user *cm = *dstptr;
769 int off = xt_compat_match_offset(match);
770 u_int16_t msize = m->u.user.match_size - off;
772 if (XT_OBJ_TO_USER(cm, m, match, msize))
775 if (match->compat_to_user) {
776 if (match->compat_to_user((void __user *)cm->data, m->data))
779 if (COMPAT_XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm)))
787 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
789 /* non-compat version may have padding after verdict */
790 struct compat_xt_standard_target {
791 struct compat_xt_entry_target t;
792 compat_uint_t verdict;
795 struct compat_xt_error_target {
796 struct compat_xt_entry_target t;
797 char errorname[XT_FUNCTION_MAXNAMELEN];
800 int xt_compat_check_entry_offsets(const void *base, const char *elems,
801 unsigned int target_offset,
802 unsigned int next_offset)
804 long size_of_base_struct = elems - (const char *)base;
805 const struct compat_xt_entry_target *t;
806 const char *e = base;
808 if (target_offset < size_of_base_struct)
811 if (target_offset + sizeof(*t) > next_offset)
814 t = (void *)(e + target_offset);
815 if (t->u.target_size < sizeof(*t))
818 if (target_offset + t->u.target_size > next_offset)
821 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) {
822 const struct compat_xt_standard_target *st = (const void *)t;
824 if (COMPAT_XT_ALIGN(target_offset + sizeof(*st)) != next_offset)
827 if (!verdict_ok(st->verdict))
829 } else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) {
830 const struct compat_xt_error_target *et = (const void *)t;
832 if (!error_tg_ok(t->u.target_size, sizeof(*et),
833 et->errorname, sizeof(et->errorname)))
837 /* compat_xt_entry match has less strict alignment requirements,
838 * otherwise they are identical. In case of padding differences
839 * we need to add compat version of xt_check_entry_match.
841 BUILD_BUG_ON(sizeof(struct compat_xt_entry_match) != sizeof(struct xt_entry_match));
843 return xt_check_entry_match(elems, base + target_offset,
844 __alignof__(struct compat_xt_entry_match));
846 EXPORT_SYMBOL(xt_compat_check_entry_offsets);
847 #endif /* CONFIG_COMPAT */
850 * xt_check_entry_offsets - validate arp/ip/ip6t_entry
852 * @base: pointer to arp/ip/ip6t_entry
853 * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems
854 * @target_offset: the arp/ip/ip6_t->target_offset
855 * @next_offset: the arp/ip/ip6_t->next_offset
857 * validates that target_offset and next_offset are sane and that all
858 * match sizes (if any) align with the target offset.
860 * This function does not validate the targets or matches themselves, it
861 * only tests that all the offsets and sizes are correct, that all
862 * match structures are aligned, and that the last structure ends where
863 * the target structure begins.
865 * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
867 * The arp/ip/ip6t_entry structure @base must have passed following tests:
868 * - it must point to a valid memory location
869 * - base to base + next_offset must be accessible, i.e. not exceed allocated
872 * A well-formed entry looks like this:
874 * ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry
875 * e->elems[]-----' | |
879 * target_offset---------------------------------' |
880 * next_offset---------------------------------------------------'
882 * elems[]: flexible array member at end of ip(6)/arpt_entry struct.
883 * This is where matches (if any) and the target reside.
884 * target_offset: beginning of target.
885 * next_offset: start of the next rule; also: size of this rule.
886 * Since targets have a minimum size, target_offset + minlen <= next_offset.
888 * Every match stores its size, sum of sizes must not exceed target_offset.
890 * Return: 0 on success, negative errno on failure.
892 int xt_check_entry_offsets(const void *base,
894 unsigned int target_offset,
895 unsigned int next_offset)
897 long size_of_base_struct = elems - (const char *)base;
898 const struct xt_entry_target *t;
899 const char *e = base;
901 /* target start is within the ip/ip6/arpt_entry struct */
902 if (target_offset < size_of_base_struct)
905 if (target_offset + sizeof(*t) > next_offset)
908 t = (void *)(e + target_offset);
909 if (t->u.target_size < sizeof(*t))
912 if (target_offset + t->u.target_size > next_offset)
915 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) {
916 const struct xt_standard_target *st = (const void *)t;
918 if (XT_ALIGN(target_offset + sizeof(*st)) != next_offset)
921 if (!verdict_ok(st->verdict))
923 } else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) {
924 const struct xt_error_target *et = (const void *)t;
926 if (!error_tg_ok(t->u.target_size, sizeof(*et),
927 et->errorname, sizeof(et->errorname)))
931 return xt_check_entry_match(elems, base + target_offset,
932 __alignof__(struct xt_entry_match));
934 EXPORT_SYMBOL(xt_check_entry_offsets);
937 * xt_alloc_entry_offsets - allocate array to store rule head offsets
939 * @size: number of entries
941 * Return: NULL or zeroed kmalloc'd or vmalloc'd array
943 unsigned int *xt_alloc_entry_offsets(unsigned int size)
945 if (size > XT_MAX_TABLE_SIZE / sizeof(unsigned int))
948 return kvcalloc(size, sizeof(unsigned int), GFP_KERNEL);
951 EXPORT_SYMBOL(xt_alloc_entry_offsets);
954 * xt_find_jump_offset - check if target is a valid jump offset
956 * @offsets: array containing all valid rule start offsets of a rule blob
957 * @target: the jump target to search for
958 * @size: entries in @offset
960 bool xt_find_jump_offset(const unsigned int *offsets,
961 unsigned int target, unsigned int size)
963 int m, low = 0, hi = size;
968 if (offsets[m] > target)
970 else if (offsets[m] < target)
978 EXPORT_SYMBOL(xt_find_jump_offset);
980 int xt_check_target(struct xt_tgchk_param *par,
981 unsigned int size, u16 proto, bool inv_proto)
985 if (XT_ALIGN(par->target->targetsize) != size) {
986 pr_err_ratelimited("%s_tables: %s.%u target: invalid size %u (kernel) != (user) %u\n",
987 xt_prefix[par->family], par->target->name,
988 par->target->revision,
989 XT_ALIGN(par->target->targetsize), size);
992 if (par->target->table != NULL &&
993 strcmp(par->target->table, par->table) != 0) {
994 pr_info_ratelimited("%s_tables: %s target: only valid in %s table, not %s\n",
995 xt_prefix[par->family], par->target->name,
996 par->target->table, par->table);
999 if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
1000 char used[64], allow[64];
1002 pr_info_ratelimited("%s_tables: %s target: used from hooks %s, but only usable from %s\n",
1003 xt_prefix[par->family], par->target->name,
1004 textify_hooks(used, sizeof(used),
1005 par->hook_mask, par->family),
1006 textify_hooks(allow, sizeof(allow),
1011 if (par->target->proto && (par->target->proto != proto || inv_proto)) {
1012 pr_info_ratelimited("%s_tables: %s target: only valid for protocol %u\n",
1013 xt_prefix[par->family], par->target->name,
1014 par->target->proto);
1017 if (par->target->checkentry != NULL) {
1018 ret = par->target->checkentry(par);
1022 /* Flag up potential errors. */
1027 EXPORT_SYMBOL_GPL(xt_check_target);
1030 * xt_copy_counters - copy counters and metadata from a sockptr_t
1033 * @len: alleged size of userspace memory
1034 * @info: where to store the xt_counters_info metadata
1036 * Copies counter meta data from @user and stores it in @info.
1038 * vmallocs memory to hold the counters, then copies the counter data
1039 * from @user to the new memory and returns a pointer to it.
1041 * If called from a compat syscall, @info gets converted automatically to the
1042 * 64bit representation.
1044 * The metadata associated with the counters is stored in @info.
1046 * Return: returns pointer that caller has to test via IS_ERR().
1047 * If IS_ERR is false, caller has to vfree the pointer.
1049 void *xt_copy_counters(sockptr_t arg, unsigned int len,
1050 struct xt_counters_info *info)
1056 #ifdef CONFIG_COMPAT
1057 if (in_compat_syscall()) {
1058 /* structures only differ in size due to alignment */
1059 struct compat_xt_counters_info compat_tmp;
1061 if (len <= sizeof(compat_tmp))
1062 return ERR_PTR(-EINVAL);
1064 len -= sizeof(compat_tmp);
1065 if (copy_from_sockptr(&compat_tmp, arg, sizeof(compat_tmp)) != 0)
1066 return ERR_PTR(-EFAULT);
1068 memcpy(info->name, compat_tmp.name, sizeof(info->name) - 1);
1069 info->num_counters = compat_tmp.num_counters;
1070 offset = sizeof(compat_tmp);
1074 if (len <= sizeof(*info))
1075 return ERR_PTR(-EINVAL);
1077 len -= sizeof(*info);
1078 if (copy_from_sockptr(info, arg, sizeof(*info)) != 0)
1079 return ERR_PTR(-EFAULT);
1081 offset = sizeof(*info);
1083 info->name[sizeof(info->name) - 1] = '\0';
1085 size = sizeof(struct xt_counters);
1086 size *= info->num_counters;
1088 if (size != (u64)len)
1089 return ERR_PTR(-EINVAL);
1093 return ERR_PTR(-ENOMEM);
1095 if (copy_from_sockptr_offset(mem, arg, offset, len) == 0)
1099 return ERR_PTR(-EFAULT);
1101 EXPORT_SYMBOL_GPL(xt_copy_counters);
1103 #ifdef CONFIG_COMPAT
1104 int xt_compat_target_offset(const struct xt_target *target)
1106 u_int16_t csize = target->compatsize ? : target->targetsize;
1107 return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
1109 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
1111 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
1114 const struct xt_target *target = t->u.kernel.target;
1115 struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
1116 int off = xt_compat_target_offset(target);
1117 u_int16_t tsize = ct->u.user.target_size;
1118 char name[sizeof(t->u.user.name)];
1121 memcpy(t, ct, sizeof(*ct));
1122 if (target->compat_from_user)
1123 target->compat_from_user(t->data, ct->data);
1125 memcpy(t->data, ct->data, tsize - sizeof(*ct));
1128 t->u.user.target_size = tsize;
1129 strlcpy(name, target->name, sizeof(name));
1130 module_put(target->me);
1131 strncpy(t->u.user.name, name, sizeof(t->u.user.name));
1136 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
1138 int xt_compat_target_to_user(const struct xt_entry_target *t,
1139 void __user **dstptr, unsigned int *size)
1141 const struct xt_target *target = t->u.kernel.target;
1142 struct compat_xt_entry_target __user *ct = *dstptr;
1143 int off = xt_compat_target_offset(target);
1144 u_int16_t tsize = t->u.user.target_size - off;
1146 if (XT_OBJ_TO_USER(ct, t, target, tsize))
1149 if (target->compat_to_user) {
1150 if (target->compat_to_user((void __user *)ct->data, t->data))
1153 if (COMPAT_XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct)))
1161 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
1164 struct xt_table_info *xt_alloc_table_info(unsigned int size)
1166 struct xt_table_info *info = NULL;
1167 size_t sz = sizeof(*info) + size;
1169 if (sz < sizeof(*info) || sz >= XT_MAX_TABLE_SIZE)
1172 info = kvmalloc(sz, GFP_KERNEL_ACCOUNT);
1176 memset(info, 0, sizeof(*info));
1180 EXPORT_SYMBOL(xt_alloc_table_info);
1182 void xt_free_table_info(struct xt_table_info *info)
1186 if (info->jumpstack != NULL) {
1187 for_each_possible_cpu(cpu)
1188 kvfree(info->jumpstack[cpu]);
1189 kvfree(info->jumpstack);
1194 EXPORT_SYMBOL(xt_free_table_info);
1196 /* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */
1197 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
1200 struct xt_table *t, *found = NULL;
1202 mutex_lock(&xt[af].mutex);
1203 list_for_each_entry(t, &net->xt.tables[af], list)
1204 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
1207 if (net == &init_net)
1210 /* Table doesn't exist in this netns, re-try init */
1211 list_for_each_entry(t, &init_net.xt.tables[af], list) {
1214 if (strcmp(t->name, name))
1216 if (!try_module_get(t->me))
1218 mutex_unlock(&xt[af].mutex);
1219 err = t->table_init(net);
1222 return ERR_PTR(err);
1227 mutex_lock(&xt[af].mutex);
1234 /* and once again: */
1235 list_for_each_entry(t, &net->xt.tables[af], list)
1236 if (strcmp(t->name, name) == 0)
1239 module_put(found->me);
1241 mutex_unlock(&xt[af].mutex);
1242 return ERR_PTR(-ENOENT);
1244 EXPORT_SYMBOL_GPL(xt_find_table_lock);
1246 struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
1249 struct xt_table *t = xt_find_table_lock(net, af, name);
1251 #ifdef CONFIG_MODULES
1253 int err = request_module("%stable_%s", xt_prefix[af], name);
1255 return ERR_PTR(err);
1256 t = xt_find_table_lock(net, af, name);
1262 EXPORT_SYMBOL_GPL(xt_request_find_table_lock);
1264 void xt_table_unlock(struct xt_table *table)
1266 mutex_unlock(&xt[table->af].mutex);
1268 EXPORT_SYMBOL_GPL(xt_table_unlock);
1270 #ifdef CONFIG_COMPAT
1271 void xt_compat_lock(u_int8_t af)
1273 mutex_lock(&xt[af].compat_mutex);
1275 EXPORT_SYMBOL_GPL(xt_compat_lock);
1277 void xt_compat_unlock(u_int8_t af)
1279 mutex_unlock(&xt[af].compat_mutex);
1281 EXPORT_SYMBOL_GPL(xt_compat_unlock);
1284 DEFINE_PER_CPU(seqcount_t, xt_recseq);
1285 EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
1287 struct static_key xt_tee_enabled __read_mostly;
1288 EXPORT_SYMBOL_GPL(xt_tee_enabled);
1290 static int xt_jumpstack_alloc(struct xt_table_info *i)
1295 size = sizeof(void **) * nr_cpu_ids;
1296 if (size > PAGE_SIZE)
1297 i->jumpstack = kvzalloc(size, GFP_KERNEL);
1299 i->jumpstack = kzalloc(size, GFP_KERNEL);
1300 if (i->jumpstack == NULL)
1303 /* ruleset without jumps -- no stack needed */
1304 if (i->stacksize == 0)
1307 /* Jumpstack needs to be able to record two full callchains, one
1308 * from the first rule set traversal, plus one table reentrancy
1309 * via -j TEE without clobbering the callchain that brought us to
1312 * This is done by allocating two jumpstacks per cpu, on reentry
1313 * the upper half of the stack is used.
1315 * see the jumpstack setup in ipt_do_table() for more details.
1317 size = sizeof(void *) * i->stacksize * 2u;
1318 for_each_possible_cpu(cpu) {
1319 i->jumpstack[cpu] = kvmalloc_node(size, GFP_KERNEL,
1321 if (i->jumpstack[cpu] == NULL)
1323 * Freeing will be done later on by the callers. The
1324 * chain is: xt_replace_table -> __do_replace ->
1325 * do_replace -> xt_free_table_info.
1333 struct xt_counters *xt_counters_alloc(unsigned int counters)
1335 struct xt_counters *mem;
1337 if (counters == 0 || counters > INT_MAX / sizeof(*mem))
1340 counters *= sizeof(*mem);
1341 if (counters > XT_MAX_TABLE_SIZE)
1344 return vzalloc(counters);
1346 EXPORT_SYMBOL(xt_counters_alloc);
1348 struct xt_table_info *
1349 xt_replace_table(struct xt_table *table,
1350 unsigned int num_counters,
1351 struct xt_table_info *newinfo,
1354 struct xt_table_info *private;
1358 ret = xt_jumpstack_alloc(newinfo);
1364 /* Do the substitution. */
1366 private = table->private;
1368 /* Check inside lock: is the old number correct? */
1369 if (num_counters != private->number) {
1370 pr_debug("num_counters != table->private->number (%u/%u)\n",
1371 num_counters, private->number);
1377 newinfo->initial_entries = private->initial_entries;
1379 * Ensure contents of newinfo are visible before assigning to
1383 table->private = newinfo;
1385 /* make sure all cpus see new ->private value */
1389 * Even though table entries have now been swapped, other CPU's
1390 * may still be using the old entries...
1394 /* ... so wait for even xt_recseq on all cpus */
1395 for_each_possible_cpu(cpu) {
1396 seqcount_t *s = &per_cpu(xt_recseq, cpu);
1397 u32 seq = raw_read_seqcount(s);
1403 } while (seq == raw_read_seqcount(s));
1407 audit_log_nfcfg(table->name, table->af, private->number,
1408 !private->number ? AUDIT_XT_OP_REGISTER :
1409 AUDIT_XT_OP_REPLACE,
1413 EXPORT_SYMBOL_GPL(xt_replace_table);
1415 struct xt_table *xt_register_table(struct net *net,
1416 const struct xt_table *input_table,
1417 struct xt_table_info *bootstrap,
1418 struct xt_table_info *newinfo)
1421 struct xt_table_info *private;
1422 struct xt_table *t, *table;
1424 /* Don't add one object to multiple lists. */
1425 table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
1431 mutex_lock(&xt[table->af].mutex);
1432 /* Don't autoload: we'd eat our tail... */
1433 list_for_each_entry(t, &net->xt.tables[table->af], list) {
1434 if (strcmp(t->name, table->name) == 0) {
1440 /* Simplifies replace_table code. */
1441 table->private = bootstrap;
1443 if (!xt_replace_table(table, 0, newinfo, &ret))
1446 private = table->private;
1447 pr_debug("table->private->number = %u\n", private->number);
1449 /* save number of initial entries */
1450 private->initial_entries = private->number;
1452 list_add(&table->list, &net->xt.tables[table->af]);
1453 mutex_unlock(&xt[table->af].mutex);
1457 mutex_unlock(&xt[table->af].mutex);
1460 return ERR_PTR(ret);
1462 EXPORT_SYMBOL_GPL(xt_register_table);
1464 void *xt_unregister_table(struct xt_table *table)
1466 struct xt_table_info *private;
1468 mutex_lock(&xt[table->af].mutex);
1469 private = table->private;
1470 list_del(&table->list);
1471 mutex_unlock(&xt[table->af].mutex);
1472 audit_log_nfcfg(table->name, table->af, private->number,
1473 AUDIT_XT_OP_UNREGISTER, GFP_KERNEL);
1478 EXPORT_SYMBOL_GPL(xt_unregister_table);
1480 #ifdef CONFIG_PROC_FS
1481 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
1483 struct net *net = seq_file_net(seq);
1484 u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
1486 mutex_lock(&xt[af].mutex);
1487 return seq_list_start(&net->xt.tables[af], *pos);
1490 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1492 struct net *net = seq_file_net(seq);
1493 u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
1495 return seq_list_next(v, &net->xt.tables[af], pos);
1498 static void xt_table_seq_stop(struct seq_file *seq, void *v)
1500 u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
1502 mutex_unlock(&xt[af].mutex);
1505 static int xt_table_seq_show(struct seq_file *seq, void *v)
1507 struct xt_table *table = list_entry(v, struct xt_table, list);
1510 seq_printf(seq, "%s\n", table->name);
1514 static const struct seq_operations xt_table_seq_ops = {
1515 .start = xt_table_seq_start,
1516 .next = xt_table_seq_next,
1517 .stop = xt_table_seq_stop,
1518 .show = xt_table_seq_show,
1522 * Traverse state for ip{,6}_{tables,matches} for helping crossing
1523 * the multi-AF mutexes.
1525 struct nf_mttg_trav {
1526 struct list_head *head, *curr;
1532 MTTG_TRAV_NFP_UNSPEC,
1537 static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
1540 static const uint8_t next_class[] = {
1541 [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
1542 [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE,
1544 uint8_t nfproto = (unsigned long)PDE_DATA(file_inode(seq->file));
1545 struct nf_mttg_trav *trav = seq->private;
1550 switch (trav->class) {
1551 case MTTG_TRAV_INIT:
1552 trav->class = MTTG_TRAV_NFP_UNSPEC;
1553 mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
1554 trav->head = trav->curr = is_target ?
1555 &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
1557 case MTTG_TRAV_NFP_UNSPEC:
1558 trav->curr = trav->curr->next;
1559 if (trav->curr != trav->head)
1561 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1562 mutex_lock(&xt[nfproto].mutex);
1563 trav->head = trav->curr = is_target ?
1564 &xt[nfproto].target : &xt[nfproto].match;
1565 trav->class = next_class[trav->class];
1567 case MTTG_TRAV_NFP_SPEC:
1568 trav->curr = trav->curr->next;
1569 if (trav->curr != trav->head)
1578 static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
1581 struct nf_mttg_trav *trav = seq->private;
1584 trav->class = MTTG_TRAV_INIT;
1585 for (j = 0; j < *pos; ++j)
1586 if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
1591 static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
1593 uint8_t nfproto = (unsigned long)PDE_DATA(file_inode(seq->file));
1594 struct nf_mttg_trav *trav = seq->private;
1596 switch (trav->class) {
1597 case MTTG_TRAV_NFP_UNSPEC:
1598 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1600 case MTTG_TRAV_NFP_SPEC:
1601 mutex_unlock(&xt[nfproto].mutex);
1606 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1608 return xt_mttg_seq_start(seq, pos, false);
1611 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1613 return xt_mttg_seq_next(seq, v, ppos, false);
1616 static int xt_match_seq_show(struct seq_file *seq, void *v)
1618 const struct nf_mttg_trav *trav = seq->private;
1619 const struct xt_match *match;
1621 switch (trav->class) {
1622 case MTTG_TRAV_NFP_UNSPEC:
1623 case MTTG_TRAV_NFP_SPEC:
1624 if (trav->curr == trav->head)
1626 match = list_entry(trav->curr, struct xt_match, list);
1628 seq_printf(seq, "%s\n", match->name);
1633 static const struct seq_operations xt_match_seq_ops = {
1634 .start = xt_match_seq_start,
1635 .next = xt_match_seq_next,
1636 .stop = xt_mttg_seq_stop,
1637 .show = xt_match_seq_show,
1640 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1642 return xt_mttg_seq_start(seq, pos, true);
1645 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1647 return xt_mttg_seq_next(seq, v, ppos, true);
1650 static int xt_target_seq_show(struct seq_file *seq, void *v)
1652 const struct nf_mttg_trav *trav = seq->private;
1653 const struct xt_target *target;
1655 switch (trav->class) {
1656 case MTTG_TRAV_NFP_UNSPEC:
1657 case MTTG_TRAV_NFP_SPEC:
1658 if (trav->curr == trav->head)
1660 target = list_entry(trav->curr, struct xt_target, list);
1662 seq_printf(seq, "%s\n", target->name);
1667 static const struct seq_operations xt_target_seq_ops = {
1668 .start = xt_target_seq_start,
1669 .next = xt_target_seq_next,
1670 .stop = xt_mttg_seq_stop,
1671 .show = xt_target_seq_show,
1674 #define FORMAT_TABLES "_tables_names"
1675 #define FORMAT_MATCHES "_tables_matches"
1676 #define FORMAT_TARGETS "_tables_targets"
1678 #endif /* CONFIG_PROC_FS */
1681 * xt_hook_ops_alloc - set up hooks for a new table
1682 * @table: table with metadata needed to set up hooks
1683 * @fn: Hook function
1685 * This function will create the nf_hook_ops that the x_table needs
1686 * to hand to xt_hook_link_net().
1688 struct nf_hook_ops *
1689 xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn)
1691 unsigned int hook_mask = table->valid_hooks;
1692 uint8_t i, num_hooks = hweight32(hook_mask);
1694 struct nf_hook_ops *ops;
1697 return ERR_PTR(-EINVAL);
1699 ops = kcalloc(num_hooks, sizeof(*ops), GFP_KERNEL);
1701 return ERR_PTR(-ENOMEM);
1703 for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
1704 hook_mask >>= 1, ++hooknum) {
1705 if (!(hook_mask & 1))
1708 ops[i].pf = table->af;
1709 ops[i].hooknum = hooknum;
1710 ops[i].priority = table->priority;
1716 EXPORT_SYMBOL_GPL(xt_hook_ops_alloc);
1718 int xt_proto_init(struct net *net, u_int8_t af)
1720 #ifdef CONFIG_PROC_FS
1721 char buf[XT_FUNCTION_MAXNAMELEN];
1722 struct proc_dir_entry *proc;
1727 if (af >= ARRAY_SIZE(xt_prefix))
1731 #ifdef CONFIG_PROC_FS
1732 root_uid = make_kuid(net->user_ns, 0);
1733 root_gid = make_kgid(net->user_ns, 0);
1735 strlcpy(buf, xt_prefix[af], sizeof(buf));
1736 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1737 proc = proc_create_net_data(buf, 0440, net->proc_net, &xt_table_seq_ops,
1738 sizeof(struct seq_net_private),
1739 (void *)(unsigned long)af);
1742 if (uid_valid(root_uid) && gid_valid(root_gid))
1743 proc_set_user(proc, root_uid, root_gid);
1745 strlcpy(buf, xt_prefix[af], sizeof(buf));
1746 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1747 proc = proc_create_seq_private(buf, 0440, net->proc_net,
1748 &xt_match_seq_ops, sizeof(struct nf_mttg_trav),
1749 (void *)(unsigned long)af);
1751 goto out_remove_tables;
1752 if (uid_valid(root_uid) && gid_valid(root_gid))
1753 proc_set_user(proc, root_uid, root_gid);
1755 strlcpy(buf, xt_prefix[af], sizeof(buf));
1756 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1757 proc = proc_create_seq_private(buf, 0440, net->proc_net,
1758 &xt_target_seq_ops, sizeof(struct nf_mttg_trav),
1759 (void *)(unsigned long)af);
1761 goto out_remove_matches;
1762 if (uid_valid(root_uid) && gid_valid(root_gid))
1763 proc_set_user(proc, root_uid, root_gid);
1768 #ifdef CONFIG_PROC_FS
1770 strlcpy(buf, xt_prefix[af], sizeof(buf));
1771 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1772 remove_proc_entry(buf, net->proc_net);
1775 strlcpy(buf, xt_prefix[af], sizeof(buf));
1776 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1777 remove_proc_entry(buf, net->proc_net);
1782 EXPORT_SYMBOL_GPL(xt_proto_init);
1784 void xt_proto_fini(struct net *net, u_int8_t af)
1786 #ifdef CONFIG_PROC_FS
1787 char buf[XT_FUNCTION_MAXNAMELEN];
1789 strlcpy(buf, xt_prefix[af], sizeof(buf));
1790 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1791 remove_proc_entry(buf, net->proc_net);
1793 strlcpy(buf, xt_prefix[af], sizeof(buf));
1794 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1795 remove_proc_entry(buf, net->proc_net);
1797 strlcpy(buf, xt_prefix[af], sizeof(buf));
1798 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1799 remove_proc_entry(buf, net->proc_net);
1800 #endif /*CONFIG_PROC_FS*/
1802 EXPORT_SYMBOL_GPL(xt_proto_fini);
1805 * xt_percpu_counter_alloc - allocate x_tables rule counter
1807 * @state: pointer to xt_percpu allocation state
1808 * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
1810 * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
1811 * contain the address of the real (percpu) counter.
1813 * Rule evaluation needs to use xt_get_this_cpu_counter() helper
1814 * to fetch the real percpu counter.
1816 * To speed up allocation and improve data locality, a 4kb block is
1817 * allocated. Freeing any counter may free an entire block, so all
1818 * counters allocated using the same state must be freed at the same
1821 * xt_percpu_counter_alloc_state contains the base address of the
1822 * allocated page and the current sub-offset.
1824 * returns false on error.
1826 bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
1827 struct xt_counters *counter)
1829 BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE < (sizeof(*counter) * 2));
1831 if (nr_cpu_ids <= 1)
1835 state->mem = __alloc_percpu(XT_PCPU_BLOCK_SIZE,
1836 XT_PCPU_BLOCK_SIZE);
1840 counter->pcnt = (__force unsigned long)(state->mem + state->off);
1841 state->off += sizeof(*counter);
1842 if (state->off > (XT_PCPU_BLOCK_SIZE - sizeof(*counter))) {
1848 EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc);
1850 void xt_percpu_counter_free(struct xt_counters *counters)
1852 unsigned long pcnt = counters->pcnt;
1854 if (nr_cpu_ids > 1 && (pcnt & (XT_PCPU_BLOCK_SIZE - 1)) == 0)
1855 free_percpu((void __percpu *)pcnt);
1857 EXPORT_SYMBOL_GPL(xt_percpu_counter_free);
1859 static int __net_init xt_net_init(struct net *net)
1863 for (i = 0; i < NFPROTO_NUMPROTO; i++)
1864 INIT_LIST_HEAD(&net->xt.tables[i]);
1868 static void __net_exit xt_net_exit(struct net *net)
1872 for (i = 0; i < NFPROTO_NUMPROTO; i++)
1873 WARN_ON_ONCE(!list_empty(&net->xt.tables[i]));
1876 static struct pernet_operations xt_net_ops = {
1877 .init = xt_net_init,
1878 .exit = xt_net_exit,
1881 static int __init xt_init(void)
1886 for_each_possible_cpu(i) {
1887 seqcount_init(&per_cpu(xt_recseq, i));
1890 xt = kcalloc(NFPROTO_NUMPROTO, sizeof(struct xt_af), GFP_KERNEL);
1894 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
1895 mutex_init(&xt[i].mutex);
1896 #ifdef CONFIG_COMPAT
1897 mutex_init(&xt[i].compat_mutex);
1898 xt[i].compat_tab = NULL;
1900 INIT_LIST_HEAD(&xt[i].target);
1901 INIT_LIST_HEAD(&xt[i].match);
1903 rv = register_pernet_subsys(&xt_net_ops);
1909 static void __exit xt_fini(void)
1911 unregister_pernet_subsys(&xt_net_ops);
1915 module_init(xt_init);
1916 module_exit(xt_fini);