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 list_for_each_entry(m
, &xt
[af
].match
, list
) {
334 if (strcmp(m
->name
, name
) == 0) {
335 if (m
->revision
> *bestp
)
336 *bestp
= m
->revision
;
337 if (m
->revision
== revision
)
342 if (af
!= NFPROTO_UNSPEC
&& !have_rev
)
343 return match_revfn(NFPROTO_UNSPEC
, name
, revision
, bestp
);
348 static int target_revfn(u8 af
, const char *name
, u8 revision
, int *bestp
)
350 const struct xt_target
*t
;
353 list_for_each_entry(t
, &xt
[af
].target
, list
) {
354 if (strcmp(t
->name
, name
) == 0) {
355 if (t
->revision
> *bestp
)
356 *bestp
= t
->revision
;
357 if (t
->revision
== revision
)
362 if (af
!= NFPROTO_UNSPEC
&& !have_rev
)
363 return target_revfn(NFPROTO_UNSPEC
, name
, revision
, bestp
);
368 /* Returns true or false (if no such extension at all) */
369 int xt_find_revision(u8 af
, const char *name
, u8 revision
, int target
,
372 int have_rev
, best
= -1;
374 mutex_lock(&xt
[af
].mutex
);
376 have_rev
= target_revfn(af
, name
, revision
, &best
);
378 have_rev
= match_revfn(af
, name
, revision
, &best
);
379 mutex_unlock(&xt
[af
].mutex
);
381 /* Nothing at all? Return 0 to try loading module. */
389 *err
= -EPROTONOSUPPORT
;
392 EXPORT_SYMBOL_GPL(xt_find_revision
);
395 textify_hooks(char *buf
, size_t size
, unsigned int mask
, uint8_t nfproto
)
397 static const char *const inetbr_names
[] = {
398 "PREROUTING", "INPUT", "FORWARD",
399 "OUTPUT", "POSTROUTING", "BROUTING",
401 static const char *const arp_names
[] = {
402 "INPUT", "FORWARD", "OUTPUT",
404 const char *const *names
;
410 names
= (nfproto
== NFPROTO_ARP
) ? arp_names
: inetbr_names
;
411 max
= (nfproto
== NFPROTO_ARP
) ? ARRAY_SIZE(arp_names
) :
412 ARRAY_SIZE(inetbr_names
);
414 for (i
= 0; i
< max
; ++i
) {
415 if (!(mask
& (1 << i
)))
417 res
= snprintf(p
, size
, "%s%s", np
? "/" : "", names
[i
]);
429 * xt_check_proc_name - check that name is suitable for /proc file creation
431 * @name: file name candidate
432 * @size: length of buffer
434 * some x_tables modules wish to create a file in /proc.
435 * This function makes sure that the name is suitable for this
436 * purpose, it checks that name is NUL terminated and isn't a 'special'
439 * returns negative number on error or 0 if name is useable.
441 int xt_check_proc_name(const char *name
, unsigned int size
)
446 if (strnlen(name
, size
) == size
)
447 return -ENAMETOOLONG
;
449 if (strcmp(name
, ".") == 0 ||
450 strcmp(name
, "..") == 0 ||
456 EXPORT_SYMBOL(xt_check_proc_name
);
458 int xt_check_match(struct xt_mtchk_param
*par
,
459 unsigned int size
, u16 proto
, bool inv_proto
)
463 if (XT_ALIGN(par
->match
->matchsize
) != size
&&
464 par
->match
->matchsize
!= -1) {
466 * ebt_among is exempt from centralized matchsize checking
467 * because it uses a dynamic-size data set.
469 pr_err_ratelimited("%s_tables: %s.%u match: invalid size %u (kernel) != (user) %u\n",
470 xt_prefix
[par
->family
], par
->match
->name
,
471 par
->match
->revision
,
472 XT_ALIGN(par
->match
->matchsize
), size
);
475 if (par
->match
->table
!= NULL
&&
476 strcmp(par
->match
->table
, par
->table
) != 0) {
477 pr_info_ratelimited("%s_tables: %s match: only valid in %s table, not %s\n",
478 xt_prefix
[par
->family
], par
->match
->name
,
479 par
->match
->table
, par
->table
);
482 if (par
->match
->hooks
&& (par
->hook_mask
& ~par
->match
->hooks
) != 0) {
483 char used
[64], allow
[64];
485 pr_info_ratelimited("%s_tables: %s match: used from hooks %s, but only valid from %s\n",
486 xt_prefix
[par
->family
], par
->match
->name
,
487 textify_hooks(used
, sizeof(used
),
488 par
->hook_mask
, par
->family
),
489 textify_hooks(allow
, sizeof(allow
),
494 if (par
->match
->proto
&& (par
->match
->proto
!= proto
|| inv_proto
)) {
495 pr_info_ratelimited("%s_tables: %s match: only valid for protocol %u\n",
496 xt_prefix
[par
->family
], par
->match
->name
,
500 if (par
->match
->checkentry
!= NULL
) {
501 ret
= par
->match
->checkentry(par
);
505 /* Flag up potential errors. */
510 EXPORT_SYMBOL_GPL(xt_check_match
);
512 /** xt_check_entry_match - check that matches end before start of target
514 * @match: beginning of xt_entry_match
515 * @target: beginning of this rules target (alleged end of matches)
516 * @alignment: alignment requirement of match structures
518 * Validates that all matches add up to the beginning of the target,
519 * and that each match covers at least the base structure size.
521 * Return: 0 on success, negative errno on failure.
523 static int xt_check_entry_match(const char *match
, const char *target
,
524 const size_t alignment
)
526 const struct xt_entry_match
*pos
;
527 int length
= target
- match
;
529 if (length
== 0) /* no matches */
532 pos
= (struct xt_entry_match
*)match
;
534 if ((unsigned long)pos
% alignment
)
537 if (length
< (int)sizeof(struct xt_entry_match
))
540 if (pos
->u
.match_size
< sizeof(struct xt_entry_match
))
543 if (pos
->u
.match_size
> length
)
546 length
-= pos
->u
.match_size
;
547 pos
= ((void *)((char *)(pos
) + (pos
)->u
.match_size
));
548 } while (length
> 0);
553 /** xt_check_table_hooks - check hook entry points are sane
555 * @info xt_table_info to check
556 * @valid_hooks - hook entry points that we can enter from
558 * Validates that the hook entry and underflows points are set up.
560 * Return: 0 on success, negative errno on failure.
562 int xt_check_table_hooks(const struct xt_table_info
*info
, unsigned int valid_hooks
)
564 const char *err
= "unsorted underflow";
565 unsigned int i
, max_uflow
, max_entry
;
566 bool check_hooks
= false;
568 BUILD_BUG_ON(ARRAY_SIZE(info
->hook_entry
) != ARRAY_SIZE(info
->underflow
));
573 for (i
= 0; i
< ARRAY_SIZE(info
->hook_entry
); i
++) {
574 if (!(valid_hooks
& (1 << i
)))
577 if (info
->hook_entry
[i
] == 0xFFFFFFFF)
579 if (info
->underflow
[i
] == 0xFFFFFFFF)
583 if (max_uflow
> info
->underflow
[i
])
586 if (max_uflow
== info
->underflow
[i
]) {
587 err
= "duplicate underflow";
590 if (max_entry
> info
->hook_entry
[i
]) {
591 err
= "unsorted entry";
594 if (max_entry
== info
->hook_entry
[i
]) {
595 err
= "duplicate entry";
599 max_entry
= info
->hook_entry
[i
];
600 max_uflow
= info
->underflow
[i
];
606 pr_err_ratelimited("%s at hook %d\n", err
, i
);
609 EXPORT_SYMBOL(xt_check_table_hooks
);
611 static bool verdict_ok(int verdict
)
617 int v
= -verdict
- 1;
619 if (verdict
== XT_RETURN
)
623 case NF_ACCEPT
: return true;
624 case NF_DROP
: return true;
625 case NF_QUEUE
: return true;
636 static bool error_tg_ok(unsigned int usersize
, unsigned int kernsize
,
637 const char *msg
, unsigned int msglen
)
639 return usersize
== kernsize
&& strnlen(msg
, msglen
) < msglen
;
643 int xt_compat_add_offset(u_int8_t af
, unsigned int offset
, int delta
)
645 struct xt_af
*xp
= &xt
[af
];
647 WARN_ON(!mutex_is_locked(&xt
[af
].compat_mutex
));
649 if (WARN_ON(!xp
->compat_tab
))
652 if (xp
->cur
>= xp
->number
)
656 delta
+= xp
->compat_tab
[xp
->cur
- 1].delta
;
657 xp
->compat_tab
[xp
->cur
].offset
= offset
;
658 xp
->compat_tab
[xp
->cur
].delta
= delta
;
662 EXPORT_SYMBOL_GPL(xt_compat_add_offset
);
664 void xt_compat_flush_offsets(u_int8_t af
)
666 WARN_ON(!mutex_is_locked(&xt
[af
].compat_mutex
));
668 if (xt
[af
].compat_tab
) {
669 vfree(xt
[af
].compat_tab
);
670 xt
[af
].compat_tab
= NULL
;
675 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets
);
677 int xt_compat_calc_jump(u_int8_t af
, unsigned int offset
)
679 struct compat_delta
*tmp
= xt
[af
].compat_tab
;
680 int mid
, left
= 0, right
= xt
[af
].cur
- 1;
682 while (left
<= right
) {
683 mid
= (left
+ right
) >> 1;
684 if (offset
> tmp
[mid
].offset
)
686 else if (offset
< tmp
[mid
].offset
)
689 return mid
? tmp
[mid
- 1].delta
: 0;
691 return left
? tmp
[left
- 1].delta
: 0;
693 EXPORT_SYMBOL_GPL(xt_compat_calc_jump
);
695 int xt_compat_init_offsets(u8 af
, unsigned int number
)
699 WARN_ON(!mutex_is_locked(&xt
[af
].compat_mutex
));
701 if (!number
|| number
> (INT_MAX
/ sizeof(struct compat_delta
)))
704 if (WARN_ON(xt
[af
].compat_tab
))
707 mem
= sizeof(struct compat_delta
) * number
;
708 if (mem
> XT_MAX_TABLE_SIZE
)
711 xt
[af
].compat_tab
= vmalloc(mem
);
712 if (!xt
[af
].compat_tab
)
715 xt
[af
].number
= number
;
720 EXPORT_SYMBOL(xt_compat_init_offsets
);
722 int xt_compat_match_offset(const struct xt_match
*match
)
724 u_int16_t csize
= match
->compatsize
? : match
->matchsize
;
725 return XT_ALIGN(match
->matchsize
) - COMPAT_XT_ALIGN(csize
);
727 EXPORT_SYMBOL_GPL(xt_compat_match_offset
);
729 void xt_compat_match_from_user(struct xt_entry_match
*m
, void **dstptr
,
732 const struct xt_match
*match
= m
->u
.kernel
.match
;
733 struct compat_xt_entry_match
*cm
= (struct compat_xt_entry_match
*)m
;
734 int pad
, off
= xt_compat_match_offset(match
);
735 u_int16_t msize
= cm
->u
.user
.match_size
;
736 char name
[sizeof(m
->u
.user
.name
)];
739 memcpy(m
, cm
, sizeof(*cm
));
740 if (match
->compat_from_user
)
741 match
->compat_from_user(m
->data
, cm
->data
);
743 memcpy(m
->data
, cm
->data
, msize
- sizeof(*cm
));
744 pad
= XT_ALIGN(match
->matchsize
) - match
->matchsize
;
746 memset(m
->data
+ match
->matchsize
, 0, pad
);
749 m
->u
.user
.match_size
= msize
;
750 strlcpy(name
, match
->name
, sizeof(name
));
751 module_put(match
->me
);
752 strncpy(m
->u
.user
.name
, name
, sizeof(m
->u
.user
.name
));
757 EXPORT_SYMBOL_GPL(xt_compat_match_from_user
);
759 #define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
760 xt_data_to_user(U->data, K->data, \
761 K->u.kernel.TYPE->usersize, \
763 COMPAT_XT_ALIGN(C_SIZE))
765 int xt_compat_match_to_user(const struct xt_entry_match
*m
,
766 void __user
**dstptr
, unsigned int *size
)
768 const struct xt_match
*match
= m
->u
.kernel
.match
;
769 struct compat_xt_entry_match __user
*cm
= *dstptr
;
770 int off
= xt_compat_match_offset(match
);
771 u_int16_t msize
= m
->u
.user
.match_size
- off
;
773 if (XT_OBJ_TO_USER(cm
, m
, match
, msize
))
776 if (match
->compat_to_user
) {
777 if (match
->compat_to_user((void __user
*)cm
->data
, m
->data
))
780 if (COMPAT_XT_DATA_TO_USER(cm
, m
, match
, msize
- sizeof(*cm
)))
788 EXPORT_SYMBOL_GPL(xt_compat_match_to_user
);
790 /* non-compat version may have padding after verdict */
791 struct compat_xt_standard_target
{
792 struct compat_xt_entry_target t
;
793 compat_uint_t verdict
;
796 struct compat_xt_error_target
{
797 struct compat_xt_entry_target t
;
798 char errorname
[XT_FUNCTION_MAXNAMELEN
];
801 int xt_compat_check_entry_offsets(const void *base
, const char *elems
,
802 unsigned int target_offset
,
803 unsigned int next_offset
)
805 long size_of_base_struct
= elems
- (const char *)base
;
806 const struct compat_xt_entry_target
*t
;
807 const char *e
= base
;
809 if (target_offset
< size_of_base_struct
)
812 if (target_offset
+ sizeof(*t
) > next_offset
)
815 t
= (void *)(e
+ target_offset
);
816 if (t
->u
.target_size
< sizeof(*t
))
819 if (target_offset
+ t
->u
.target_size
> next_offset
)
822 if (strcmp(t
->u
.user
.name
, XT_STANDARD_TARGET
) == 0) {
823 const struct compat_xt_standard_target
*st
= (const void *)t
;
825 if (COMPAT_XT_ALIGN(target_offset
+ sizeof(*st
)) != next_offset
)
828 if (!verdict_ok(st
->verdict
))
830 } else if (strcmp(t
->u
.user
.name
, XT_ERROR_TARGET
) == 0) {
831 const struct compat_xt_error_target
*et
= (const void *)t
;
833 if (!error_tg_ok(t
->u
.target_size
, sizeof(*et
),
834 et
->errorname
, sizeof(et
->errorname
)))
838 /* compat_xt_entry match has less strict alignment requirements,
839 * otherwise they are identical. In case of padding differences
840 * we need to add compat version of xt_check_entry_match.
842 BUILD_BUG_ON(sizeof(struct compat_xt_entry_match
) != sizeof(struct xt_entry_match
));
844 return xt_check_entry_match(elems
, base
+ target_offset
,
845 __alignof__(struct compat_xt_entry_match
));
847 EXPORT_SYMBOL(xt_compat_check_entry_offsets
);
848 #endif /* CONFIG_COMPAT */
851 * xt_check_entry_offsets - validate arp/ip/ip6t_entry
853 * @base: pointer to arp/ip/ip6t_entry
854 * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems
855 * @target_offset: the arp/ip/ip6_t->target_offset
856 * @next_offset: the arp/ip/ip6_t->next_offset
858 * validates that target_offset and next_offset are sane and that all
859 * match sizes (if any) align with the target offset.
861 * This function does not validate the targets or matches themselves, it
862 * only tests that all the offsets and sizes are correct, that all
863 * match structures are aligned, and that the last structure ends where
864 * the target structure begins.
866 * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
868 * The arp/ip/ip6t_entry structure @base must have passed following tests:
869 * - it must point to a valid memory location
870 * - base to base + next_offset must be accessible, i.e. not exceed allocated
873 * A well-formed entry looks like this:
875 * ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry
876 * e->elems[]-----' | |
880 * target_offset---------------------------------' |
881 * next_offset---------------------------------------------------'
883 * elems[]: flexible array member at end of ip(6)/arpt_entry struct.
884 * This is where matches (if any) and the target reside.
885 * target_offset: beginning of target.
886 * next_offset: start of the next rule; also: size of this rule.
887 * Since targets have a minimum size, target_offset + minlen <= next_offset.
889 * Every match stores its size, sum of sizes must not exceed target_offset.
891 * Return: 0 on success, negative errno on failure.
893 int xt_check_entry_offsets(const void *base
,
895 unsigned int target_offset
,
896 unsigned int next_offset
)
898 long size_of_base_struct
= elems
- (const char *)base
;
899 const struct xt_entry_target
*t
;
900 const char *e
= base
;
902 /* target start is within the ip/ip6/arpt_entry struct */
903 if (target_offset
< size_of_base_struct
)
906 if (target_offset
+ sizeof(*t
) > next_offset
)
909 t
= (void *)(e
+ target_offset
);
910 if (t
->u
.target_size
< sizeof(*t
))
913 if (target_offset
+ t
->u
.target_size
> next_offset
)
916 if (strcmp(t
->u
.user
.name
, XT_STANDARD_TARGET
) == 0) {
917 const struct xt_standard_target
*st
= (const void *)t
;
919 if (XT_ALIGN(target_offset
+ sizeof(*st
)) != next_offset
)
922 if (!verdict_ok(st
->verdict
))
924 } else if (strcmp(t
->u
.user
.name
, XT_ERROR_TARGET
) == 0) {
925 const struct xt_error_target
*et
= (const void *)t
;
927 if (!error_tg_ok(t
->u
.target_size
, sizeof(*et
),
928 et
->errorname
, sizeof(et
->errorname
)))
932 return xt_check_entry_match(elems
, base
+ target_offset
,
933 __alignof__(struct xt_entry_match
));
935 EXPORT_SYMBOL(xt_check_entry_offsets
);
938 * xt_alloc_entry_offsets - allocate array to store rule head offsets
940 * @size: number of entries
942 * Return: NULL or zeroed kmalloc'd or vmalloc'd array
944 unsigned int *xt_alloc_entry_offsets(unsigned int size
)
946 if (size
> XT_MAX_TABLE_SIZE
/ sizeof(unsigned int))
949 return kvcalloc(size
, sizeof(unsigned int), GFP_KERNEL
);
952 EXPORT_SYMBOL(xt_alloc_entry_offsets
);
955 * xt_find_jump_offset - check if target is a valid jump offset
957 * @offsets: array containing all valid rule start offsets of a rule blob
958 * @target: the jump target to search for
959 * @size: entries in @offset
961 bool xt_find_jump_offset(const unsigned int *offsets
,
962 unsigned int target
, unsigned int size
)
964 int m
, low
= 0, hi
= size
;
969 if (offsets
[m
] > target
)
971 else if (offsets
[m
] < target
)
979 EXPORT_SYMBOL(xt_find_jump_offset
);
981 int xt_check_target(struct xt_tgchk_param
*par
,
982 unsigned int size
, u16 proto
, bool inv_proto
)
986 if (XT_ALIGN(par
->target
->targetsize
) != size
) {
987 pr_err_ratelimited("%s_tables: %s.%u target: invalid size %u (kernel) != (user) %u\n",
988 xt_prefix
[par
->family
], par
->target
->name
,
989 par
->target
->revision
,
990 XT_ALIGN(par
->target
->targetsize
), size
);
993 if (par
->target
->table
!= NULL
&&
994 strcmp(par
->target
->table
, par
->table
) != 0) {
995 pr_info_ratelimited("%s_tables: %s target: only valid in %s table, not %s\n",
996 xt_prefix
[par
->family
], par
->target
->name
,
997 par
->target
->table
, par
->table
);
1000 if (par
->target
->hooks
&& (par
->hook_mask
& ~par
->target
->hooks
) != 0) {
1001 char used
[64], allow
[64];
1003 pr_info_ratelimited("%s_tables: %s target: used from hooks %s, but only usable from %s\n",
1004 xt_prefix
[par
->family
], par
->target
->name
,
1005 textify_hooks(used
, sizeof(used
),
1006 par
->hook_mask
, par
->family
),
1007 textify_hooks(allow
, sizeof(allow
),
1012 if (par
->target
->proto
&& (par
->target
->proto
!= proto
|| inv_proto
)) {
1013 pr_info_ratelimited("%s_tables: %s target: only valid for protocol %u\n",
1014 xt_prefix
[par
->family
], par
->target
->name
,
1015 par
->target
->proto
);
1018 if (par
->target
->checkentry
!= NULL
) {
1019 ret
= par
->target
->checkentry(par
);
1023 /* Flag up potential errors. */
1028 EXPORT_SYMBOL_GPL(xt_check_target
);
1031 * xt_copy_counters - copy counters and metadata from a sockptr_t
1034 * @len: alleged size of userspace memory
1035 * @info: where to store the xt_counters_info metadata
1037 * Copies counter meta data from @user and stores it in @info.
1039 * vmallocs memory to hold the counters, then copies the counter data
1040 * from @user to the new memory and returns a pointer to it.
1042 * If called from a compat syscall, @info gets converted automatically to the
1043 * 64bit representation.
1045 * The metadata associated with the counters is stored in @info.
1047 * Return: returns pointer that caller has to test via IS_ERR().
1048 * If IS_ERR is false, caller has to vfree the pointer.
1050 void *xt_copy_counters(sockptr_t arg
, unsigned int len
,
1051 struct xt_counters_info
*info
)
1057 #ifdef CONFIG_COMPAT
1058 if (in_compat_syscall()) {
1059 /* structures only differ in size due to alignment */
1060 struct compat_xt_counters_info compat_tmp
;
1062 if (len
<= sizeof(compat_tmp
))
1063 return ERR_PTR(-EINVAL
);
1065 len
-= sizeof(compat_tmp
);
1066 if (copy_from_sockptr(&compat_tmp
, arg
, sizeof(compat_tmp
)) != 0)
1067 return ERR_PTR(-EFAULT
);
1069 memcpy(info
->name
, compat_tmp
.name
, sizeof(info
->name
) - 1);
1070 info
->num_counters
= compat_tmp
.num_counters
;
1071 offset
= sizeof(compat_tmp
);
1075 if (len
<= sizeof(*info
))
1076 return ERR_PTR(-EINVAL
);
1078 len
-= sizeof(*info
);
1079 if (copy_from_sockptr(info
, arg
, sizeof(*info
)) != 0)
1080 return ERR_PTR(-EFAULT
);
1082 offset
= sizeof(*info
);
1084 info
->name
[sizeof(info
->name
) - 1] = '\0';
1086 size
= sizeof(struct xt_counters
);
1087 size
*= info
->num_counters
;
1089 if (size
!= (u64
)len
)
1090 return ERR_PTR(-EINVAL
);
1094 return ERR_PTR(-ENOMEM
);
1096 if (copy_from_sockptr_offset(mem
, arg
, offset
, len
) == 0)
1100 return ERR_PTR(-EFAULT
);
1102 EXPORT_SYMBOL_GPL(xt_copy_counters
);
1104 #ifdef CONFIG_COMPAT
1105 int xt_compat_target_offset(const struct xt_target
*target
)
1107 u_int16_t csize
= target
->compatsize
? : target
->targetsize
;
1108 return XT_ALIGN(target
->targetsize
) - COMPAT_XT_ALIGN(csize
);
1110 EXPORT_SYMBOL_GPL(xt_compat_target_offset
);
1112 void xt_compat_target_from_user(struct xt_entry_target
*t
, void **dstptr
,
1115 const struct xt_target
*target
= t
->u
.kernel
.target
;
1116 struct compat_xt_entry_target
*ct
= (struct compat_xt_entry_target
*)t
;
1117 int pad
, off
= xt_compat_target_offset(target
);
1118 u_int16_t tsize
= ct
->u
.user
.target_size
;
1119 char name
[sizeof(t
->u
.user
.name
)];
1122 memcpy(t
, ct
, sizeof(*ct
));
1123 if (target
->compat_from_user
)
1124 target
->compat_from_user(t
->data
, ct
->data
);
1126 memcpy(t
->data
, ct
->data
, tsize
- sizeof(*ct
));
1127 pad
= XT_ALIGN(target
->targetsize
) - target
->targetsize
;
1129 memset(t
->data
+ target
->targetsize
, 0, pad
);
1132 t
->u
.user
.target_size
= tsize
;
1133 strlcpy(name
, target
->name
, sizeof(name
));
1134 module_put(target
->me
);
1135 strncpy(t
->u
.user
.name
, name
, sizeof(t
->u
.user
.name
));
1140 EXPORT_SYMBOL_GPL(xt_compat_target_from_user
);
1142 int xt_compat_target_to_user(const struct xt_entry_target
*t
,
1143 void __user
**dstptr
, unsigned int *size
)
1145 const struct xt_target
*target
= t
->u
.kernel
.target
;
1146 struct compat_xt_entry_target __user
*ct
= *dstptr
;
1147 int off
= xt_compat_target_offset(target
);
1148 u_int16_t tsize
= t
->u
.user
.target_size
- off
;
1150 if (XT_OBJ_TO_USER(ct
, t
, target
, tsize
))
1153 if (target
->compat_to_user
) {
1154 if (target
->compat_to_user((void __user
*)ct
->data
, t
->data
))
1157 if (COMPAT_XT_DATA_TO_USER(ct
, t
, target
, tsize
- sizeof(*ct
)))
1165 EXPORT_SYMBOL_GPL(xt_compat_target_to_user
);
1168 struct xt_table_info
*xt_alloc_table_info(unsigned int size
)
1170 struct xt_table_info
*info
= NULL
;
1171 size_t sz
= sizeof(*info
) + size
;
1173 if (sz
< sizeof(*info
) || sz
>= XT_MAX_TABLE_SIZE
)
1176 info
= kvmalloc(sz
, GFP_KERNEL_ACCOUNT
);
1180 memset(info
, 0, sizeof(*info
));
1184 EXPORT_SYMBOL(xt_alloc_table_info
);
1186 void xt_free_table_info(struct xt_table_info
*info
)
1190 if (info
->jumpstack
!= NULL
) {
1191 for_each_possible_cpu(cpu
)
1192 kvfree(info
->jumpstack
[cpu
]);
1193 kvfree(info
->jumpstack
);
1198 EXPORT_SYMBOL(xt_free_table_info
);
1200 /* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */
1201 struct xt_table
*xt_find_table_lock(struct net
*net
, u_int8_t af
,
1204 struct xt_table
*t
, *found
= NULL
;
1206 mutex_lock(&xt
[af
].mutex
);
1207 list_for_each_entry(t
, &net
->xt
.tables
[af
], list
)
1208 if (strcmp(t
->name
, name
) == 0 && try_module_get(t
->me
))
1211 if (net
== &init_net
)
1214 /* Table doesn't exist in this netns, re-try init */
1215 list_for_each_entry(t
, &init_net
.xt
.tables
[af
], list
) {
1218 if (strcmp(t
->name
, name
))
1220 if (!try_module_get(t
->me
))
1222 mutex_unlock(&xt
[af
].mutex
);
1223 err
= t
->table_init(net
);
1226 return ERR_PTR(err
);
1231 mutex_lock(&xt
[af
].mutex
);
1238 /* and once again: */
1239 list_for_each_entry(t
, &net
->xt
.tables
[af
], list
)
1240 if (strcmp(t
->name
, name
) == 0)
1243 module_put(found
->me
);
1245 mutex_unlock(&xt
[af
].mutex
);
1246 return ERR_PTR(-ENOENT
);
1248 EXPORT_SYMBOL_GPL(xt_find_table_lock
);
1250 struct xt_table
*xt_request_find_table_lock(struct net
*net
, u_int8_t af
,
1253 struct xt_table
*t
= xt_find_table_lock(net
, af
, name
);
1255 #ifdef CONFIG_MODULES
1257 int err
= request_module("%stable_%s", xt_prefix
[af
], name
);
1259 return ERR_PTR(err
);
1260 t
= xt_find_table_lock(net
, af
, name
);
1266 EXPORT_SYMBOL_GPL(xt_request_find_table_lock
);
1268 void xt_table_unlock(struct xt_table
*table
)
1270 mutex_unlock(&xt
[table
->af
].mutex
);
1272 EXPORT_SYMBOL_GPL(xt_table_unlock
);
1274 #ifdef CONFIG_COMPAT
1275 void xt_compat_lock(u_int8_t af
)
1277 mutex_lock(&xt
[af
].compat_mutex
);
1279 EXPORT_SYMBOL_GPL(xt_compat_lock
);
1281 void xt_compat_unlock(u_int8_t af
)
1283 mutex_unlock(&xt
[af
].compat_mutex
);
1285 EXPORT_SYMBOL_GPL(xt_compat_unlock
);
1288 DEFINE_PER_CPU(seqcount_t
, xt_recseq
);
1289 EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq
);
1291 struct static_key xt_tee_enabled __read_mostly
;
1292 EXPORT_SYMBOL_GPL(xt_tee_enabled
);
1294 static int xt_jumpstack_alloc(struct xt_table_info
*i
)
1299 size
= sizeof(void **) * nr_cpu_ids
;
1300 if (size
> PAGE_SIZE
)
1301 i
->jumpstack
= kvzalloc(size
, GFP_KERNEL
);
1303 i
->jumpstack
= kzalloc(size
, GFP_KERNEL
);
1304 if (i
->jumpstack
== NULL
)
1307 /* ruleset without jumps -- no stack needed */
1308 if (i
->stacksize
== 0)
1311 /* Jumpstack needs to be able to record two full callchains, one
1312 * from the first rule set traversal, plus one table reentrancy
1313 * via -j TEE without clobbering the callchain that brought us to
1316 * This is done by allocating two jumpstacks per cpu, on reentry
1317 * the upper half of the stack is used.
1319 * see the jumpstack setup in ipt_do_table() for more details.
1321 size
= sizeof(void *) * i
->stacksize
* 2u;
1322 for_each_possible_cpu(cpu
) {
1323 i
->jumpstack
[cpu
] = kvmalloc_node(size
, GFP_KERNEL
,
1325 if (i
->jumpstack
[cpu
] == NULL
)
1327 * Freeing will be done later on by the callers. The
1328 * chain is: xt_replace_table -> __do_replace ->
1329 * do_replace -> xt_free_table_info.
1337 struct xt_counters
*xt_counters_alloc(unsigned int counters
)
1339 struct xt_counters
*mem
;
1341 if (counters
== 0 || counters
> INT_MAX
/ sizeof(*mem
))
1344 counters
*= sizeof(*mem
);
1345 if (counters
> XT_MAX_TABLE_SIZE
)
1348 return vzalloc(counters
);
1350 EXPORT_SYMBOL(xt_counters_alloc
);
1352 struct xt_table_info
1353 *xt_table_get_private_protected(const struct xt_table
*table
)
1355 return rcu_dereference_protected(table
->private,
1356 mutex_is_locked(&xt
[table
->af
].mutex
));
1358 EXPORT_SYMBOL(xt_table_get_private_protected
);
1360 struct xt_table_info
*
1361 xt_replace_table(struct xt_table
*table
,
1362 unsigned int num_counters
,
1363 struct xt_table_info
*newinfo
,
1366 struct xt_table_info
*private;
1369 ret
= xt_jumpstack_alloc(newinfo
);
1375 /* Do the substitution. */
1376 private = xt_table_get_private_protected(table
);
1378 /* Check inside lock: is the old number correct? */
1379 if (num_counters
!= private->number
) {
1380 pr_debug("num_counters != table->private->number (%u/%u)\n",
1381 num_counters
, private->number
);
1386 newinfo
->initial_entries
= private->initial_entries
;
1388 rcu_assign_pointer(table
->private, newinfo
);
1391 audit_log_nfcfg(table
->name
, table
->af
, private->number
,
1392 !private->number
? AUDIT_XT_OP_REGISTER
:
1393 AUDIT_XT_OP_REPLACE
,
1397 EXPORT_SYMBOL_GPL(xt_replace_table
);
1399 struct xt_table
*xt_register_table(struct net
*net
,
1400 const struct xt_table
*input_table
,
1401 struct xt_table_info
*bootstrap
,
1402 struct xt_table_info
*newinfo
)
1405 struct xt_table_info
*private;
1406 struct xt_table
*t
, *table
;
1408 /* Don't add one object to multiple lists. */
1409 table
= kmemdup(input_table
, sizeof(struct xt_table
), GFP_KERNEL
);
1415 mutex_lock(&xt
[table
->af
].mutex
);
1416 /* Don't autoload: we'd eat our tail... */
1417 list_for_each_entry(t
, &net
->xt
.tables
[table
->af
], list
) {
1418 if (strcmp(t
->name
, table
->name
) == 0) {
1424 /* Simplifies replace_table code. */
1425 rcu_assign_pointer(table
->private, bootstrap
);
1427 if (!xt_replace_table(table
, 0, newinfo
, &ret
))
1430 private = xt_table_get_private_protected(table
);
1431 pr_debug("table->private->number = %u\n", private->number
);
1433 /* save number of initial entries */
1434 private->initial_entries
= private->number
;
1436 list_add(&table
->list
, &net
->xt
.tables
[table
->af
]);
1437 mutex_unlock(&xt
[table
->af
].mutex
);
1441 mutex_unlock(&xt
[table
->af
].mutex
);
1444 return ERR_PTR(ret
);
1446 EXPORT_SYMBOL_GPL(xt_register_table
);
1448 void *xt_unregister_table(struct xt_table
*table
)
1450 struct xt_table_info
*private;
1452 mutex_lock(&xt
[table
->af
].mutex
);
1453 private = xt_table_get_private_protected(table
);
1454 RCU_INIT_POINTER(table
->private, NULL
);
1455 list_del(&table
->list
);
1456 mutex_unlock(&xt
[table
->af
].mutex
);
1457 audit_log_nfcfg(table
->name
, table
->af
, private->number
,
1458 AUDIT_XT_OP_UNREGISTER
, GFP_KERNEL
);
1463 EXPORT_SYMBOL_GPL(xt_unregister_table
);
1465 #ifdef CONFIG_PROC_FS
1466 static void *xt_table_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1468 struct net
*net
= seq_file_net(seq
);
1469 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1471 mutex_lock(&xt
[af
].mutex
);
1472 return seq_list_start(&net
->xt
.tables
[af
], *pos
);
1475 static void *xt_table_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
1477 struct net
*net
= seq_file_net(seq
);
1478 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1480 return seq_list_next(v
, &net
->xt
.tables
[af
], pos
);
1483 static void xt_table_seq_stop(struct seq_file
*seq
, void *v
)
1485 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1487 mutex_unlock(&xt
[af
].mutex
);
1490 static int xt_table_seq_show(struct seq_file
*seq
, void *v
)
1492 struct xt_table
*table
= list_entry(v
, struct xt_table
, list
);
1495 seq_printf(seq
, "%s\n", table
->name
);
1499 static const struct seq_operations xt_table_seq_ops
= {
1500 .start
= xt_table_seq_start
,
1501 .next
= xt_table_seq_next
,
1502 .stop
= xt_table_seq_stop
,
1503 .show
= xt_table_seq_show
,
1507 * Traverse state for ip{,6}_{tables,matches} for helping crossing
1508 * the multi-AF mutexes.
1510 struct nf_mttg_trav
{
1511 struct list_head
*head
, *curr
;
1517 MTTG_TRAV_NFP_UNSPEC
,
1522 static void *xt_mttg_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
,
1525 static const uint8_t next_class
[] = {
1526 [MTTG_TRAV_NFP_UNSPEC
] = MTTG_TRAV_NFP_SPEC
,
1527 [MTTG_TRAV_NFP_SPEC
] = MTTG_TRAV_DONE
,
1529 uint8_t nfproto
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1530 struct nf_mttg_trav
*trav
= seq
->private;
1535 switch (trav
->class) {
1536 case MTTG_TRAV_INIT
:
1537 trav
->class = MTTG_TRAV_NFP_UNSPEC
;
1538 mutex_lock(&xt
[NFPROTO_UNSPEC
].mutex
);
1539 trav
->head
= trav
->curr
= is_target
?
1540 &xt
[NFPROTO_UNSPEC
].target
: &xt
[NFPROTO_UNSPEC
].match
;
1542 case MTTG_TRAV_NFP_UNSPEC
:
1543 trav
->curr
= trav
->curr
->next
;
1544 if (trav
->curr
!= trav
->head
)
1546 mutex_unlock(&xt
[NFPROTO_UNSPEC
].mutex
);
1547 mutex_lock(&xt
[nfproto
].mutex
);
1548 trav
->head
= trav
->curr
= is_target
?
1549 &xt
[nfproto
].target
: &xt
[nfproto
].match
;
1550 trav
->class = next_class
[trav
->class];
1552 case MTTG_TRAV_NFP_SPEC
:
1553 trav
->curr
= trav
->curr
->next
;
1554 if (trav
->curr
!= trav
->head
)
1563 static void *xt_mttg_seq_start(struct seq_file
*seq
, loff_t
*pos
,
1566 struct nf_mttg_trav
*trav
= seq
->private;
1569 trav
->class = MTTG_TRAV_INIT
;
1570 for (j
= 0; j
< *pos
; ++j
)
1571 if (xt_mttg_seq_next(seq
, NULL
, NULL
, is_target
) == NULL
)
1576 static void xt_mttg_seq_stop(struct seq_file
*seq
, void *v
)
1578 uint8_t nfproto
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1579 struct nf_mttg_trav
*trav
= seq
->private;
1581 switch (trav
->class) {
1582 case MTTG_TRAV_NFP_UNSPEC
:
1583 mutex_unlock(&xt
[NFPROTO_UNSPEC
].mutex
);
1585 case MTTG_TRAV_NFP_SPEC
:
1586 mutex_unlock(&xt
[nfproto
].mutex
);
1591 static void *xt_match_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1593 return xt_mttg_seq_start(seq
, pos
, false);
1596 static void *xt_match_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
)
1598 return xt_mttg_seq_next(seq
, v
, ppos
, false);
1601 static int xt_match_seq_show(struct seq_file
*seq
, void *v
)
1603 const struct nf_mttg_trav
*trav
= seq
->private;
1604 const struct xt_match
*match
;
1606 switch (trav
->class) {
1607 case MTTG_TRAV_NFP_UNSPEC
:
1608 case MTTG_TRAV_NFP_SPEC
:
1609 if (trav
->curr
== trav
->head
)
1611 match
= list_entry(trav
->curr
, struct xt_match
, list
);
1613 seq_printf(seq
, "%s\n", match
->name
);
1618 static const struct seq_operations xt_match_seq_ops
= {
1619 .start
= xt_match_seq_start
,
1620 .next
= xt_match_seq_next
,
1621 .stop
= xt_mttg_seq_stop
,
1622 .show
= xt_match_seq_show
,
1625 static void *xt_target_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1627 return xt_mttg_seq_start(seq
, pos
, true);
1630 static void *xt_target_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
)
1632 return xt_mttg_seq_next(seq
, v
, ppos
, true);
1635 static int xt_target_seq_show(struct seq_file
*seq
, void *v
)
1637 const struct nf_mttg_trav
*trav
= seq
->private;
1638 const struct xt_target
*target
;
1640 switch (trav
->class) {
1641 case MTTG_TRAV_NFP_UNSPEC
:
1642 case MTTG_TRAV_NFP_SPEC
:
1643 if (trav
->curr
== trav
->head
)
1645 target
= list_entry(trav
->curr
, struct xt_target
, list
);
1647 seq_printf(seq
, "%s\n", target
->name
);
1652 static const struct seq_operations xt_target_seq_ops
= {
1653 .start
= xt_target_seq_start
,
1654 .next
= xt_target_seq_next
,
1655 .stop
= xt_mttg_seq_stop
,
1656 .show
= xt_target_seq_show
,
1659 #define FORMAT_TABLES "_tables_names"
1660 #define FORMAT_MATCHES "_tables_matches"
1661 #define FORMAT_TARGETS "_tables_targets"
1663 #endif /* CONFIG_PROC_FS */
1666 * xt_hook_ops_alloc - set up hooks for a new table
1667 * @table: table with metadata needed to set up hooks
1668 * @fn: Hook function
1670 * This function will create the nf_hook_ops that the x_table needs
1671 * to hand to xt_hook_link_net().
1673 struct nf_hook_ops
*
1674 xt_hook_ops_alloc(const struct xt_table
*table
, nf_hookfn
*fn
)
1676 unsigned int hook_mask
= table
->valid_hooks
;
1677 uint8_t i
, num_hooks
= hweight32(hook_mask
);
1679 struct nf_hook_ops
*ops
;
1682 return ERR_PTR(-EINVAL
);
1684 ops
= kcalloc(num_hooks
, sizeof(*ops
), GFP_KERNEL
);
1686 return ERR_PTR(-ENOMEM
);
1688 for (i
= 0, hooknum
= 0; i
< num_hooks
&& hook_mask
!= 0;
1689 hook_mask
>>= 1, ++hooknum
) {
1690 if (!(hook_mask
& 1))
1693 ops
[i
].pf
= table
->af
;
1694 ops
[i
].hooknum
= hooknum
;
1695 ops
[i
].priority
= table
->priority
;
1701 EXPORT_SYMBOL_GPL(xt_hook_ops_alloc
);
1703 int xt_proto_init(struct net
*net
, u_int8_t af
)
1705 #ifdef CONFIG_PROC_FS
1706 char buf
[XT_FUNCTION_MAXNAMELEN
];
1707 struct proc_dir_entry
*proc
;
1712 if (af
>= ARRAY_SIZE(xt_prefix
))
1716 #ifdef CONFIG_PROC_FS
1717 root_uid
= make_kuid(net
->user_ns
, 0);
1718 root_gid
= make_kgid(net
->user_ns
, 0);
1720 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1721 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1722 proc
= proc_create_net_data(buf
, 0440, net
->proc_net
, &xt_table_seq_ops
,
1723 sizeof(struct seq_net_private
),
1724 (void *)(unsigned long)af
);
1727 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1728 proc_set_user(proc
, root_uid
, root_gid
);
1730 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1731 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1732 proc
= proc_create_seq_private(buf
, 0440, net
->proc_net
,
1733 &xt_match_seq_ops
, sizeof(struct nf_mttg_trav
),
1734 (void *)(unsigned long)af
);
1736 goto out_remove_tables
;
1737 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1738 proc_set_user(proc
, root_uid
, root_gid
);
1740 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1741 strlcat(buf
, FORMAT_TARGETS
, sizeof(buf
));
1742 proc
= proc_create_seq_private(buf
, 0440, net
->proc_net
,
1743 &xt_target_seq_ops
, sizeof(struct nf_mttg_trav
),
1744 (void *)(unsigned long)af
);
1746 goto out_remove_matches
;
1747 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1748 proc_set_user(proc
, root_uid
, root_gid
);
1753 #ifdef CONFIG_PROC_FS
1755 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1756 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1757 remove_proc_entry(buf
, net
->proc_net
);
1760 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1761 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1762 remove_proc_entry(buf
, net
->proc_net
);
1767 EXPORT_SYMBOL_GPL(xt_proto_init
);
1769 void xt_proto_fini(struct net
*net
, u_int8_t af
)
1771 #ifdef CONFIG_PROC_FS
1772 char buf
[XT_FUNCTION_MAXNAMELEN
];
1774 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1775 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1776 remove_proc_entry(buf
, net
->proc_net
);
1778 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1779 strlcat(buf
, FORMAT_TARGETS
, sizeof(buf
));
1780 remove_proc_entry(buf
, net
->proc_net
);
1782 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1783 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1784 remove_proc_entry(buf
, net
->proc_net
);
1785 #endif /*CONFIG_PROC_FS*/
1787 EXPORT_SYMBOL_GPL(xt_proto_fini
);
1790 * xt_percpu_counter_alloc - allocate x_tables rule counter
1792 * @state: pointer to xt_percpu allocation state
1793 * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
1795 * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
1796 * contain the address of the real (percpu) counter.
1798 * Rule evaluation needs to use xt_get_this_cpu_counter() helper
1799 * to fetch the real percpu counter.
1801 * To speed up allocation and improve data locality, a 4kb block is
1802 * allocated. Freeing any counter may free an entire block, so all
1803 * counters allocated using the same state must be freed at the same
1806 * xt_percpu_counter_alloc_state contains the base address of the
1807 * allocated page and the current sub-offset.
1809 * returns false on error.
1811 bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state
*state
,
1812 struct xt_counters
*counter
)
1814 BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE
< (sizeof(*counter
) * 2));
1816 if (nr_cpu_ids
<= 1)
1820 state
->mem
= __alloc_percpu(XT_PCPU_BLOCK_SIZE
,
1821 XT_PCPU_BLOCK_SIZE
);
1825 counter
->pcnt
= (__force
unsigned long)(state
->mem
+ state
->off
);
1826 state
->off
+= sizeof(*counter
);
1827 if (state
->off
> (XT_PCPU_BLOCK_SIZE
- sizeof(*counter
))) {
1833 EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc
);
1835 void xt_percpu_counter_free(struct xt_counters
*counters
)
1837 unsigned long pcnt
= counters
->pcnt
;
1839 if (nr_cpu_ids
> 1 && (pcnt
& (XT_PCPU_BLOCK_SIZE
- 1)) == 0)
1840 free_percpu((void __percpu
*)pcnt
);
1842 EXPORT_SYMBOL_GPL(xt_percpu_counter_free
);
1844 static int __net_init
xt_net_init(struct net
*net
)
1848 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
1849 INIT_LIST_HEAD(&net
->xt
.tables
[i
]);
1853 static void __net_exit
xt_net_exit(struct net
*net
)
1857 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
1858 WARN_ON_ONCE(!list_empty(&net
->xt
.tables
[i
]));
1861 static struct pernet_operations xt_net_ops
= {
1862 .init
= xt_net_init
,
1863 .exit
= xt_net_exit
,
1866 static int __init
xt_init(void)
1871 for_each_possible_cpu(i
) {
1872 seqcount_init(&per_cpu(xt_recseq
, i
));
1875 xt
= kcalloc(NFPROTO_NUMPROTO
, sizeof(struct xt_af
), GFP_KERNEL
);
1879 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++) {
1880 mutex_init(&xt
[i
].mutex
);
1881 #ifdef CONFIG_COMPAT
1882 mutex_init(&xt
[i
].compat_mutex
);
1883 xt
[i
].compat_tab
= NULL
;
1885 INIT_LIST_HEAD(&xt
[i
].target
);
1886 INIT_LIST_HEAD(&xt
[i
].match
);
1888 rv
= register_pernet_subsys(&xt_net_ops
);
1894 static void __exit
xt_fini(void)
1896 unregister_pernet_subsys(&xt_net_ops
);
1900 module_init(xt_init
);
1901 module_exit(xt_fini
);