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 pad
, 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
));
746 pad
= XT_ALIGN(match
->matchsize
) - match
->matchsize
;
748 memset(m
->data
+ match
->matchsize
, 0, pad
);
751 m
->u
.user
.match_size
= msize
;
752 strlcpy(name
, match
->name
, sizeof(name
));
753 module_put(match
->me
);
754 strncpy(m
->u
.user
.name
, name
, sizeof(m
->u
.user
.name
));
759 EXPORT_SYMBOL_GPL(xt_compat_match_from_user
);
761 #define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
762 xt_data_to_user(U->data, K->data, \
763 K->u.kernel.TYPE->usersize, \
765 COMPAT_XT_ALIGN(C_SIZE))
767 int xt_compat_match_to_user(const struct xt_entry_match
*m
,
768 void __user
**dstptr
, unsigned int *size
)
770 const struct xt_match
*match
= m
->u
.kernel
.match
;
771 struct compat_xt_entry_match __user
*cm
= *dstptr
;
772 int off
= xt_compat_match_offset(match
);
773 u_int16_t msize
= m
->u
.user
.match_size
- off
;
775 if (XT_OBJ_TO_USER(cm
, m
, match
, msize
))
778 if (match
->compat_to_user
) {
779 if (match
->compat_to_user((void __user
*)cm
->data
, m
->data
))
782 if (COMPAT_XT_DATA_TO_USER(cm
, m
, match
, msize
- sizeof(*cm
)))
790 EXPORT_SYMBOL_GPL(xt_compat_match_to_user
);
792 /* non-compat version may have padding after verdict */
793 struct compat_xt_standard_target
{
794 struct compat_xt_entry_target t
;
795 compat_uint_t verdict
;
798 struct compat_xt_error_target
{
799 struct compat_xt_entry_target t
;
800 char errorname
[XT_FUNCTION_MAXNAMELEN
];
803 int xt_compat_check_entry_offsets(const void *base
, const char *elems
,
804 unsigned int target_offset
,
805 unsigned int next_offset
)
807 long size_of_base_struct
= elems
- (const char *)base
;
808 const struct compat_xt_entry_target
*t
;
809 const char *e
= base
;
811 if (target_offset
< size_of_base_struct
)
814 if (target_offset
+ sizeof(*t
) > next_offset
)
817 t
= (void *)(e
+ target_offset
);
818 if (t
->u
.target_size
< sizeof(*t
))
821 if (target_offset
+ t
->u
.target_size
> next_offset
)
824 if (strcmp(t
->u
.user
.name
, XT_STANDARD_TARGET
) == 0) {
825 const struct compat_xt_standard_target
*st
= (const void *)t
;
827 if (COMPAT_XT_ALIGN(target_offset
+ sizeof(*st
)) != next_offset
)
830 if (!verdict_ok(st
->verdict
))
832 } else if (strcmp(t
->u
.user
.name
, XT_ERROR_TARGET
) == 0) {
833 const struct compat_xt_error_target
*et
= (const void *)t
;
835 if (!error_tg_ok(t
->u
.target_size
, sizeof(*et
),
836 et
->errorname
, sizeof(et
->errorname
)))
840 /* compat_xt_entry match has less strict alignment requirements,
841 * otherwise they are identical. In case of padding differences
842 * we need to add compat version of xt_check_entry_match.
844 BUILD_BUG_ON(sizeof(struct compat_xt_entry_match
) != sizeof(struct xt_entry_match
));
846 return xt_check_entry_match(elems
, base
+ target_offset
,
847 __alignof__(struct compat_xt_entry_match
));
849 EXPORT_SYMBOL(xt_compat_check_entry_offsets
);
850 #endif /* CONFIG_COMPAT */
853 * xt_check_entry_offsets - validate arp/ip/ip6t_entry
855 * @base: pointer to arp/ip/ip6t_entry
856 * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems
857 * @target_offset: the arp/ip/ip6_t->target_offset
858 * @next_offset: the arp/ip/ip6_t->next_offset
860 * validates that target_offset and next_offset are sane and that all
861 * match sizes (if any) align with the target offset.
863 * This function does not validate the targets or matches themselves, it
864 * only tests that all the offsets and sizes are correct, that all
865 * match structures are aligned, and that the last structure ends where
866 * the target structure begins.
868 * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
870 * The arp/ip/ip6t_entry structure @base must have passed following tests:
871 * - it must point to a valid memory location
872 * - base to base + next_offset must be accessible, i.e. not exceed allocated
875 * A well-formed entry looks like this:
877 * ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry
878 * e->elems[]-----' | |
882 * target_offset---------------------------------' |
883 * next_offset---------------------------------------------------'
885 * elems[]: flexible array member at end of ip(6)/arpt_entry struct.
886 * This is where matches (if any) and the target reside.
887 * target_offset: beginning of target.
888 * next_offset: start of the next rule; also: size of this rule.
889 * Since targets have a minimum size, target_offset + minlen <= next_offset.
891 * Every match stores its size, sum of sizes must not exceed target_offset.
893 * Return: 0 on success, negative errno on failure.
895 int xt_check_entry_offsets(const void *base
,
897 unsigned int target_offset
,
898 unsigned int next_offset
)
900 long size_of_base_struct
= elems
- (const char *)base
;
901 const struct xt_entry_target
*t
;
902 const char *e
= base
;
904 /* target start is within the ip/ip6/arpt_entry struct */
905 if (target_offset
< size_of_base_struct
)
908 if (target_offset
+ sizeof(*t
) > next_offset
)
911 t
= (void *)(e
+ target_offset
);
912 if (t
->u
.target_size
< sizeof(*t
))
915 if (target_offset
+ t
->u
.target_size
> next_offset
)
918 if (strcmp(t
->u
.user
.name
, XT_STANDARD_TARGET
) == 0) {
919 const struct xt_standard_target
*st
= (const void *)t
;
921 if (XT_ALIGN(target_offset
+ sizeof(*st
)) != next_offset
)
924 if (!verdict_ok(st
->verdict
))
926 } else if (strcmp(t
->u
.user
.name
, XT_ERROR_TARGET
) == 0) {
927 const struct xt_error_target
*et
= (const void *)t
;
929 if (!error_tg_ok(t
->u
.target_size
, sizeof(*et
),
930 et
->errorname
, sizeof(et
->errorname
)))
934 return xt_check_entry_match(elems
, base
+ target_offset
,
935 __alignof__(struct xt_entry_match
));
937 EXPORT_SYMBOL(xt_check_entry_offsets
);
940 * xt_alloc_entry_offsets - allocate array to store rule head offsets
942 * @size: number of entries
944 * Return: NULL or zeroed kmalloc'd or vmalloc'd array
946 unsigned int *xt_alloc_entry_offsets(unsigned int size
)
948 if (size
> XT_MAX_TABLE_SIZE
/ sizeof(unsigned int))
951 return kvcalloc(size
, sizeof(unsigned int), GFP_KERNEL
);
954 EXPORT_SYMBOL(xt_alloc_entry_offsets
);
957 * xt_find_jump_offset - check if target is a valid jump offset
959 * @offsets: array containing all valid rule start offsets of a rule blob
960 * @target: the jump target to search for
961 * @size: entries in @offset
963 bool xt_find_jump_offset(const unsigned int *offsets
,
964 unsigned int target
, unsigned int size
)
966 int m
, low
= 0, hi
= size
;
971 if (offsets
[m
] > target
)
973 else if (offsets
[m
] < target
)
981 EXPORT_SYMBOL(xt_find_jump_offset
);
983 int xt_check_target(struct xt_tgchk_param
*par
,
984 unsigned int size
, u16 proto
, bool inv_proto
)
988 if (XT_ALIGN(par
->target
->targetsize
) != size
) {
989 pr_err_ratelimited("%s_tables: %s.%u target: invalid size %u (kernel) != (user) %u\n",
990 xt_prefix
[par
->family
], par
->target
->name
,
991 par
->target
->revision
,
992 XT_ALIGN(par
->target
->targetsize
), size
);
995 if (par
->target
->table
!= NULL
&&
996 strcmp(par
->target
->table
, par
->table
) != 0) {
997 pr_info_ratelimited("%s_tables: %s target: only valid in %s table, not %s\n",
998 xt_prefix
[par
->family
], par
->target
->name
,
999 par
->target
->table
, par
->table
);
1002 if (par
->target
->hooks
&& (par
->hook_mask
& ~par
->target
->hooks
) != 0) {
1003 char used
[64], allow
[64];
1005 pr_info_ratelimited("%s_tables: %s target: used from hooks %s, but only usable from %s\n",
1006 xt_prefix
[par
->family
], par
->target
->name
,
1007 textify_hooks(used
, sizeof(used
),
1008 par
->hook_mask
, par
->family
),
1009 textify_hooks(allow
, sizeof(allow
),
1014 if (par
->target
->proto
&& (par
->target
->proto
!= proto
|| inv_proto
)) {
1015 pr_info_ratelimited("%s_tables: %s target: only valid for protocol %u\n",
1016 xt_prefix
[par
->family
], par
->target
->name
,
1017 par
->target
->proto
);
1020 if (par
->target
->checkentry
!= NULL
) {
1021 ret
= par
->target
->checkentry(par
);
1025 /* Flag up potential errors. */
1030 EXPORT_SYMBOL_GPL(xt_check_target
);
1033 * xt_copy_counters - copy counters and metadata from a sockptr_t
1036 * @len: alleged size of userspace memory
1037 * @info: where to store the xt_counters_info metadata
1039 * Copies counter meta data from @user and stores it in @info.
1041 * vmallocs memory to hold the counters, then copies the counter data
1042 * from @user to the new memory and returns a pointer to it.
1044 * If called from a compat syscall, @info gets converted automatically to the
1045 * 64bit representation.
1047 * The metadata associated with the counters is stored in @info.
1049 * Return: returns pointer that caller has to test via IS_ERR().
1050 * If IS_ERR is false, caller has to vfree the pointer.
1052 void *xt_copy_counters(sockptr_t arg
, unsigned int len
,
1053 struct xt_counters_info
*info
)
1059 #ifdef CONFIG_COMPAT
1060 if (in_compat_syscall()) {
1061 /* structures only differ in size due to alignment */
1062 struct compat_xt_counters_info compat_tmp
;
1064 if (len
<= sizeof(compat_tmp
))
1065 return ERR_PTR(-EINVAL
);
1067 len
-= sizeof(compat_tmp
);
1068 if (copy_from_sockptr(&compat_tmp
, arg
, sizeof(compat_tmp
)) != 0)
1069 return ERR_PTR(-EFAULT
);
1071 memcpy(info
->name
, compat_tmp
.name
, sizeof(info
->name
) - 1);
1072 info
->num_counters
= compat_tmp
.num_counters
;
1073 offset
= sizeof(compat_tmp
);
1077 if (len
<= sizeof(*info
))
1078 return ERR_PTR(-EINVAL
);
1080 len
-= sizeof(*info
);
1081 if (copy_from_sockptr(info
, arg
, sizeof(*info
)) != 0)
1082 return ERR_PTR(-EFAULT
);
1084 offset
= sizeof(*info
);
1086 info
->name
[sizeof(info
->name
) - 1] = '\0';
1088 size
= sizeof(struct xt_counters
);
1089 size
*= info
->num_counters
;
1091 if (size
!= (u64
)len
)
1092 return ERR_PTR(-EINVAL
);
1096 return ERR_PTR(-ENOMEM
);
1098 if (copy_from_sockptr_offset(mem
, arg
, offset
, len
) == 0)
1102 return ERR_PTR(-EFAULT
);
1104 EXPORT_SYMBOL_GPL(xt_copy_counters
);
1106 #ifdef CONFIG_COMPAT
1107 int xt_compat_target_offset(const struct xt_target
*target
)
1109 u_int16_t csize
= target
->compatsize
? : target
->targetsize
;
1110 return XT_ALIGN(target
->targetsize
) - COMPAT_XT_ALIGN(csize
);
1112 EXPORT_SYMBOL_GPL(xt_compat_target_offset
);
1114 void xt_compat_target_from_user(struct xt_entry_target
*t
, void **dstptr
,
1117 const struct xt_target
*target
= t
->u
.kernel
.target
;
1118 struct compat_xt_entry_target
*ct
= (struct compat_xt_entry_target
*)t
;
1119 int pad
, off
= xt_compat_target_offset(target
);
1120 u_int16_t tsize
= ct
->u
.user
.target_size
;
1121 char name
[sizeof(t
->u
.user
.name
)];
1124 memcpy(t
, ct
, sizeof(*ct
));
1125 if (target
->compat_from_user
)
1126 target
->compat_from_user(t
->data
, ct
->data
);
1128 memcpy(t
->data
, ct
->data
, tsize
- sizeof(*ct
));
1129 pad
= XT_ALIGN(target
->targetsize
) - target
->targetsize
;
1131 memset(t
->data
+ target
->targetsize
, 0, pad
);
1134 t
->u
.user
.target_size
= tsize
;
1135 strlcpy(name
, target
->name
, sizeof(name
));
1136 module_put(target
->me
);
1137 strncpy(t
->u
.user
.name
, name
, sizeof(t
->u
.user
.name
));
1142 EXPORT_SYMBOL_GPL(xt_compat_target_from_user
);
1144 int xt_compat_target_to_user(const struct xt_entry_target
*t
,
1145 void __user
**dstptr
, unsigned int *size
)
1147 const struct xt_target
*target
= t
->u
.kernel
.target
;
1148 struct compat_xt_entry_target __user
*ct
= *dstptr
;
1149 int off
= xt_compat_target_offset(target
);
1150 u_int16_t tsize
= t
->u
.user
.target_size
- off
;
1152 if (XT_OBJ_TO_USER(ct
, t
, target
, tsize
))
1155 if (target
->compat_to_user
) {
1156 if (target
->compat_to_user((void __user
*)ct
->data
, t
->data
))
1159 if (COMPAT_XT_DATA_TO_USER(ct
, t
, target
, tsize
- sizeof(*ct
)))
1167 EXPORT_SYMBOL_GPL(xt_compat_target_to_user
);
1170 struct xt_table_info
*xt_alloc_table_info(unsigned int size
)
1172 struct xt_table_info
*info
= NULL
;
1173 size_t sz
= sizeof(*info
) + size
;
1175 if (sz
< sizeof(*info
) || sz
>= XT_MAX_TABLE_SIZE
)
1178 info
= kvmalloc(sz
, GFP_KERNEL_ACCOUNT
);
1182 memset(info
, 0, sizeof(*info
));
1186 EXPORT_SYMBOL(xt_alloc_table_info
);
1188 void xt_free_table_info(struct xt_table_info
*info
)
1192 if (info
->jumpstack
!= NULL
) {
1193 for_each_possible_cpu(cpu
)
1194 kvfree(info
->jumpstack
[cpu
]);
1195 kvfree(info
->jumpstack
);
1200 EXPORT_SYMBOL(xt_free_table_info
);
1202 /* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */
1203 struct xt_table
*xt_find_table_lock(struct net
*net
, u_int8_t af
,
1206 struct xt_table
*t
, *found
= NULL
;
1208 mutex_lock(&xt
[af
].mutex
);
1209 list_for_each_entry(t
, &net
->xt
.tables
[af
], list
)
1210 if (strcmp(t
->name
, name
) == 0 && try_module_get(t
->me
))
1213 if (net
== &init_net
)
1216 /* Table doesn't exist in this netns, re-try init */
1217 list_for_each_entry(t
, &init_net
.xt
.tables
[af
], list
) {
1220 if (strcmp(t
->name
, name
))
1222 if (!try_module_get(t
->me
))
1224 mutex_unlock(&xt
[af
].mutex
);
1225 err
= t
->table_init(net
);
1228 return ERR_PTR(err
);
1233 mutex_lock(&xt
[af
].mutex
);
1240 /* and once again: */
1241 list_for_each_entry(t
, &net
->xt
.tables
[af
], list
)
1242 if (strcmp(t
->name
, name
) == 0)
1245 module_put(found
->me
);
1247 mutex_unlock(&xt
[af
].mutex
);
1248 return ERR_PTR(-ENOENT
);
1250 EXPORT_SYMBOL_GPL(xt_find_table_lock
);
1252 struct xt_table
*xt_request_find_table_lock(struct net
*net
, u_int8_t af
,
1255 struct xt_table
*t
= xt_find_table_lock(net
, af
, name
);
1257 #ifdef CONFIG_MODULES
1259 int err
= request_module("%stable_%s", xt_prefix
[af
], name
);
1261 return ERR_PTR(err
);
1262 t
= xt_find_table_lock(net
, af
, name
);
1268 EXPORT_SYMBOL_GPL(xt_request_find_table_lock
);
1270 void xt_table_unlock(struct xt_table
*table
)
1272 mutex_unlock(&xt
[table
->af
].mutex
);
1274 EXPORT_SYMBOL_GPL(xt_table_unlock
);
1276 #ifdef CONFIG_COMPAT
1277 void xt_compat_lock(u_int8_t af
)
1279 mutex_lock(&xt
[af
].compat_mutex
);
1281 EXPORT_SYMBOL_GPL(xt_compat_lock
);
1283 void xt_compat_unlock(u_int8_t af
)
1285 mutex_unlock(&xt
[af
].compat_mutex
);
1287 EXPORT_SYMBOL_GPL(xt_compat_unlock
);
1290 DEFINE_PER_CPU(seqcount_t
, xt_recseq
);
1291 EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq
);
1293 struct static_key xt_tee_enabled __read_mostly
;
1294 EXPORT_SYMBOL_GPL(xt_tee_enabled
);
1296 static int xt_jumpstack_alloc(struct xt_table_info
*i
)
1301 size
= sizeof(void **) * nr_cpu_ids
;
1302 if (size
> PAGE_SIZE
)
1303 i
->jumpstack
= kvzalloc(size
, GFP_KERNEL
);
1305 i
->jumpstack
= kzalloc(size
, GFP_KERNEL
);
1306 if (i
->jumpstack
== NULL
)
1309 /* ruleset without jumps -- no stack needed */
1310 if (i
->stacksize
== 0)
1313 /* Jumpstack needs to be able to record two full callchains, one
1314 * from the first rule set traversal, plus one table reentrancy
1315 * via -j TEE without clobbering the callchain that brought us to
1318 * This is done by allocating two jumpstacks per cpu, on reentry
1319 * the upper half of the stack is used.
1321 * see the jumpstack setup in ipt_do_table() for more details.
1323 size
= sizeof(void *) * i
->stacksize
* 2u;
1324 for_each_possible_cpu(cpu
) {
1325 i
->jumpstack
[cpu
] = kvmalloc_node(size
, GFP_KERNEL
,
1327 if (i
->jumpstack
[cpu
] == NULL
)
1329 * Freeing will be done later on by the callers. The
1330 * chain is: xt_replace_table -> __do_replace ->
1331 * do_replace -> xt_free_table_info.
1339 struct xt_counters
*xt_counters_alloc(unsigned int counters
)
1341 struct xt_counters
*mem
;
1343 if (counters
== 0 || counters
> INT_MAX
/ sizeof(*mem
))
1346 counters
*= sizeof(*mem
);
1347 if (counters
> XT_MAX_TABLE_SIZE
)
1350 return vzalloc(counters
);
1352 EXPORT_SYMBOL(xt_counters_alloc
);
1354 struct xt_table_info
1355 *xt_table_get_private_protected(const struct xt_table
*table
)
1357 return rcu_dereference_protected(table
->private,
1358 mutex_is_locked(&xt
[table
->af
].mutex
));
1360 EXPORT_SYMBOL(xt_table_get_private_protected
);
1362 struct xt_table_info
*
1363 xt_replace_table(struct xt_table
*table
,
1364 unsigned int num_counters
,
1365 struct xt_table_info
*newinfo
,
1368 struct xt_table_info
*private;
1371 ret
= xt_jumpstack_alloc(newinfo
);
1377 /* Do the substitution. */
1378 private = xt_table_get_private_protected(table
);
1380 /* Check inside lock: is the old number correct? */
1381 if (num_counters
!= private->number
) {
1382 pr_debug("num_counters != table->private->number (%u/%u)\n",
1383 num_counters
, private->number
);
1388 newinfo
->initial_entries
= private->initial_entries
;
1390 rcu_assign_pointer(table
->private, newinfo
);
1393 audit_log_nfcfg(table
->name
, table
->af
, private->number
,
1394 !private->number
? AUDIT_XT_OP_REGISTER
:
1395 AUDIT_XT_OP_REPLACE
,
1399 EXPORT_SYMBOL_GPL(xt_replace_table
);
1401 struct xt_table
*xt_register_table(struct net
*net
,
1402 const struct xt_table
*input_table
,
1403 struct xt_table_info
*bootstrap
,
1404 struct xt_table_info
*newinfo
)
1407 struct xt_table_info
*private;
1408 struct xt_table
*t
, *table
;
1410 /* Don't add one object to multiple lists. */
1411 table
= kmemdup(input_table
, sizeof(struct xt_table
), GFP_KERNEL
);
1417 mutex_lock(&xt
[table
->af
].mutex
);
1418 /* Don't autoload: we'd eat our tail... */
1419 list_for_each_entry(t
, &net
->xt
.tables
[table
->af
], list
) {
1420 if (strcmp(t
->name
, table
->name
) == 0) {
1426 /* Simplifies replace_table code. */
1427 rcu_assign_pointer(table
->private, bootstrap
);
1429 if (!xt_replace_table(table
, 0, newinfo
, &ret
))
1432 private = xt_table_get_private_protected(table
);
1433 pr_debug("table->private->number = %u\n", private->number
);
1435 /* save number of initial entries */
1436 private->initial_entries
= private->number
;
1438 list_add(&table
->list
, &net
->xt
.tables
[table
->af
]);
1439 mutex_unlock(&xt
[table
->af
].mutex
);
1443 mutex_unlock(&xt
[table
->af
].mutex
);
1446 return ERR_PTR(ret
);
1448 EXPORT_SYMBOL_GPL(xt_register_table
);
1450 void *xt_unregister_table(struct xt_table
*table
)
1452 struct xt_table_info
*private;
1454 mutex_lock(&xt
[table
->af
].mutex
);
1455 private = xt_table_get_private_protected(table
);
1456 RCU_INIT_POINTER(table
->private, NULL
);
1457 list_del(&table
->list
);
1458 mutex_unlock(&xt
[table
->af
].mutex
);
1459 audit_log_nfcfg(table
->name
, table
->af
, private->number
,
1460 AUDIT_XT_OP_UNREGISTER
, GFP_KERNEL
);
1465 EXPORT_SYMBOL_GPL(xt_unregister_table
);
1467 #ifdef CONFIG_PROC_FS
1468 static void *xt_table_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1470 struct net
*net
= seq_file_net(seq
);
1471 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1473 mutex_lock(&xt
[af
].mutex
);
1474 return seq_list_start(&net
->xt
.tables
[af
], *pos
);
1477 static void *xt_table_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
1479 struct net
*net
= seq_file_net(seq
);
1480 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1482 return seq_list_next(v
, &net
->xt
.tables
[af
], pos
);
1485 static void xt_table_seq_stop(struct seq_file
*seq
, void *v
)
1487 u_int8_t af
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1489 mutex_unlock(&xt
[af
].mutex
);
1492 static int xt_table_seq_show(struct seq_file
*seq
, void *v
)
1494 struct xt_table
*table
= list_entry(v
, struct xt_table
, list
);
1497 seq_printf(seq
, "%s\n", table
->name
);
1501 static const struct seq_operations xt_table_seq_ops
= {
1502 .start
= xt_table_seq_start
,
1503 .next
= xt_table_seq_next
,
1504 .stop
= xt_table_seq_stop
,
1505 .show
= xt_table_seq_show
,
1509 * Traverse state for ip{,6}_{tables,matches} for helping crossing
1510 * the multi-AF mutexes.
1512 struct nf_mttg_trav
{
1513 struct list_head
*head
, *curr
;
1519 MTTG_TRAV_NFP_UNSPEC
,
1524 static void *xt_mttg_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
,
1527 static const uint8_t next_class
[] = {
1528 [MTTG_TRAV_NFP_UNSPEC
] = MTTG_TRAV_NFP_SPEC
,
1529 [MTTG_TRAV_NFP_SPEC
] = MTTG_TRAV_DONE
,
1531 uint8_t nfproto
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1532 struct nf_mttg_trav
*trav
= seq
->private;
1537 switch (trav
->class) {
1538 case MTTG_TRAV_INIT
:
1539 trav
->class = MTTG_TRAV_NFP_UNSPEC
;
1540 mutex_lock(&xt
[NFPROTO_UNSPEC
].mutex
);
1541 trav
->head
= trav
->curr
= is_target
?
1542 &xt
[NFPROTO_UNSPEC
].target
: &xt
[NFPROTO_UNSPEC
].match
;
1544 case MTTG_TRAV_NFP_UNSPEC
:
1545 trav
->curr
= trav
->curr
->next
;
1546 if (trav
->curr
!= trav
->head
)
1548 mutex_unlock(&xt
[NFPROTO_UNSPEC
].mutex
);
1549 mutex_lock(&xt
[nfproto
].mutex
);
1550 trav
->head
= trav
->curr
= is_target
?
1551 &xt
[nfproto
].target
: &xt
[nfproto
].match
;
1552 trav
->class = next_class
[trav
->class];
1554 case MTTG_TRAV_NFP_SPEC
:
1555 trav
->curr
= trav
->curr
->next
;
1556 if (trav
->curr
!= trav
->head
)
1565 static void *xt_mttg_seq_start(struct seq_file
*seq
, loff_t
*pos
,
1568 struct nf_mttg_trav
*trav
= seq
->private;
1571 trav
->class = MTTG_TRAV_INIT
;
1572 for (j
= 0; j
< *pos
; ++j
)
1573 if (xt_mttg_seq_next(seq
, NULL
, NULL
, is_target
) == NULL
)
1578 static void xt_mttg_seq_stop(struct seq_file
*seq
, void *v
)
1580 uint8_t nfproto
= (unsigned long)PDE_DATA(file_inode(seq
->file
));
1581 struct nf_mttg_trav
*trav
= seq
->private;
1583 switch (trav
->class) {
1584 case MTTG_TRAV_NFP_UNSPEC
:
1585 mutex_unlock(&xt
[NFPROTO_UNSPEC
].mutex
);
1587 case MTTG_TRAV_NFP_SPEC
:
1588 mutex_unlock(&xt
[nfproto
].mutex
);
1593 static void *xt_match_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1595 return xt_mttg_seq_start(seq
, pos
, false);
1598 static void *xt_match_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
)
1600 return xt_mttg_seq_next(seq
, v
, ppos
, false);
1603 static int xt_match_seq_show(struct seq_file
*seq
, void *v
)
1605 const struct nf_mttg_trav
*trav
= seq
->private;
1606 const struct xt_match
*match
;
1608 switch (trav
->class) {
1609 case MTTG_TRAV_NFP_UNSPEC
:
1610 case MTTG_TRAV_NFP_SPEC
:
1611 if (trav
->curr
== trav
->head
)
1613 match
= list_entry(trav
->curr
, struct xt_match
, list
);
1615 seq_printf(seq
, "%s\n", match
->name
);
1620 static const struct seq_operations xt_match_seq_ops
= {
1621 .start
= xt_match_seq_start
,
1622 .next
= xt_match_seq_next
,
1623 .stop
= xt_mttg_seq_stop
,
1624 .show
= xt_match_seq_show
,
1627 static void *xt_target_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1629 return xt_mttg_seq_start(seq
, pos
, true);
1632 static void *xt_target_seq_next(struct seq_file
*seq
, void *v
, loff_t
*ppos
)
1634 return xt_mttg_seq_next(seq
, v
, ppos
, true);
1637 static int xt_target_seq_show(struct seq_file
*seq
, void *v
)
1639 const struct nf_mttg_trav
*trav
= seq
->private;
1640 const struct xt_target
*target
;
1642 switch (trav
->class) {
1643 case MTTG_TRAV_NFP_UNSPEC
:
1644 case MTTG_TRAV_NFP_SPEC
:
1645 if (trav
->curr
== trav
->head
)
1647 target
= list_entry(trav
->curr
, struct xt_target
, list
);
1649 seq_printf(seq
, "%s\n", target
->name
);
1654 static const struct seq_operations xt_target_seq_ops
= {
1655 .start
= xt_target_seq_start
,
1656 .next
= xt_target_seq_next
,
1657 .stop
= xt_mttg_seq_stop
,
1658 .show
= xt_target_seq_show
,
1661 #define FORMAT_TABLES "_tables_names"
1662 #define FORMAT_MATCHES "_tables_matches"
1663 #define FORMAT_TARGETS "_tables_targets"
1665 #endif /* CONFIG_PROC_FS */
1668 * xt_hook_ops_alloc - set up hooks for a new table
1669 * @table: table with metadata needed to set up hooks
1670 * @fn: Hook function
1672 * This function will create the nf_hook_ops that the x_table needs
1673 * to hand to xt_hook_link_net().
1675 struct nf_hook_ops
*
1676 xt_hook_ops_alloc(const struct xt_table
*table
, nf_hookfn
*fn
)
1678 unsigned int hook_mask
= table
->valid_hooks
;
1679 uint8_t i
, num_hooks
= hweight32(hook_mask
);
1681 struct nf_hook_ops
*ops
;
1684 return ERR_PTR(-EINVAL
);
1686 ops
= kcalloc(num_hooks
, sizeof(*ops
), GFP_KERNEL
);
1688 return ERR_PTR(-ENOMEM
);
1690 for (i
= 0, hooknum
= 0; i
< num_hooks
&& hook_mask
!= 0;
1691 hook_mask
>>= 1, ++hooknum
) {
1692 if (!(hook_mask
& 1))
1695 ops
[i
].pf
= table
->af
;
1696 ops
[i
].hooknum
= hooknum
;
1697 ops
[i
].priority
= table
->priority
;
1703 EXPORT_SYMBOL_GPL(xt_hook_ops_alloc
);
1705 int xt_proto_init(struct net
*net
, u_int8_t af
)
1707 #ifdef CONFIG_PROC_FS
1708 char buf
[XT_FUNCTION_MAXNAMELEN
];
1709 struct proc_dir_entry
*proc
;
1714 if (af
>= ARRAY_SIZE(xt_prefix
))
1718 #ifdef CONFIG_PROC_FS
1719 root_uid
= make_kuid(net
->user_ns
, 0);
1720 root_gid
= make_kgid(net
->user_ns
, 0);
1722 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1723 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1724 proc
= proc_create_net_data(buf
, 0440, net
->proc_net
, &xt_table_seq_ops
,
1725 sizeof(struct seq_net_private
),
1726 (void *)(unsigned long)af
);
1729 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1730 proc_set_user(proc
, root_uid
, root_gid
);
1732 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1733 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1734 proc
= proc_create_seq_private(buf
, 0440, net
->proc_net
,
1735 &xt_match_seq_ops
, sizeof(struct nf_mttg_trav
),
1736 (void *)(unsigned long)af
);
1738 goto out_remove_tables
;
1739 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1740 proc_set_user(proc
, root_uid
, root_gid
);
1742 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1743 strlcat(buf
, FORMAT_TARGETS
, sizeof(buf
));
1744 proc
= proc_create_seq_private(buf
, 0440, net
->proc_net
,
1745 &xt_target_seq_ops
, sizeof(struct nf_mttg_trav
),
1746 (void *)(unsigned long)af
);
1748 goto out_remove_matches
;
1749 if (uid_valid(root_uid
) && gid_valid(root_gid
))
1750 proc_set_user(proc
, root_uid
, root_gid
);
1755 #ifdef CONFIG_PROC_FS
1757 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1758 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1759 remove_proc_entry(buf
, net
->proc_net
);
1762 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1763 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1764 remove_proc_entry(buf
, net
->proc_net
);
1769 EXPORT_SYMBOL_GPL(xt_proto_init
);
1771 void xt_proto_fini(struct net
*net
, u_int8_t af
)
1773 #ifdef CONFIG_PROC_FS
1774 char buf
[XT_FUNCTION_MAXNAMELEN
];
1776 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1777 strlcat(buf
, FORMAT_TABLES
, sizeof(buf
));
1778 remove_proc_entry(buf
, net
->proc_net
);
1780 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1781 strlcat(buf
, FORMAT_TARGETS
, sizeof(buf
));
1782 remove_proc_entry(buf
, net
->proc_net
);
1784 strlcpy(buf
, xt_prefix
[af
], sizeof(buf
));
1785 strlcat(buf
, FORMAT_MATCHES
, sizeof(buf
));
1786 remove_proc_entry(buf
, net
->proc_net
);
1787 #endif /*CONFIG_PROC_FS*/
1789 EXPORT_SYMBOL_GPL(xt_proto_fini
);
1792 * xt_percpu_counter_alloc - allocate x_tables rule counter
1794 * @state: pointer to xt_percpu allocation state
1795 * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
1797 * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
1798 * contain the address of the real (percpu) counter.
1800 * Rule evaluation needs to use xt_get_this_cpu_counter() helper
1801 * to fetch the real percpu counter.
1803 * To speed up allocation and improve data locality, a 4kb block is
1804 * allocated. Freeing any counter may free an entire block, so all
1805 * counters allocated using the same state must be freed at the same
1808 * xt_percpu_counter_alloc_state contains the base address of the
1809 * allocated page and the current sub-offset.
1811 * returns false on error.
1813 bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state
*state
,
1814 struct xt_counters
*counter
)
1816 BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE
< (sizeof(*counter
) * 2));
1818 if (nr_cpu_ids
<= 1)
1822 state
->mem
= __alloc_percpu(XT_PCPU_BLOCK_SIZE
,
1823 XT_PCPU_BLOCK_SIZE
);
1827 counter
->pcnt
= (__force
unsigned long)(state
->mem
+ state
->off
);
1828 state
->off
+= sizeof(*counter
);
1829 if (state
->off
> (XT_PCPU_BLOCK_SIZE
- sizeof(*counter
))) {
1835 EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc
);
1837 void xt_percpu_counter_free(struct xt_counters
*counters
)
1839 unsigned long pcnt
= counters
->pcnt
;
1841 if (nr_cpu_ids
> 1 && (pcnt
& (XT_PCPU_BLOCK_SIZE
- 1)) == 0)
1842 free_percpu((void __percpu
*)pcnt
);
1844 EXPORT_SYMBOL_GPL(xt_percpu_counter_free
);
1846 static int __net_init
xt_net_init(struct net
*net
)
1850 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
1851 INIT_LIST_HEAD(&net
->xt
.tables
[i
]);
1855 static void __net_exit
xt_net_exit(struct net
*net
)
1859 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
1860 WARN_ON_ONCE(!list_empty(&net
->xt
.tables
[i
]));
1863 static struct pernet_operations xt_net_ops
= {
1864 .init
= xt_net_init
,
1865 .exit
= xt_net_exit
,
1868 static int __init
xt_init(void)
1873 for_each_possible_cpu(i
) {
1874 seqcount_init(&per_cpu(xt_recseq
, i
));
1877 xt
= kcalloc(NFPROTO_NUMPROTO
, sizeof(struct xt_af
), GFP_KERNEL
);
1881 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++) {
1882 mutex_init(&xt
[i
].mutex
);
1883 #ifdef CONFIG_COMPAT
1884 mutex_init(&xt
[i
].compat_mutex
);
1885 xt
[i
].compat_tab
= NULL
;
1887 INIT_LIST_HEAD(&xt
[i
].target
);
1888 INIT_LIST_HEAD(&xt
[i
].match
);
1890 rv
= register_pernet_subsys(&xt_net_ops
);
1896 static void __exit
xt_fini(void)
1898 unregister_pernet_subsys(&xt_net_ops
);
1902 module_init(xt_init
);
1903 module_exit(xt_fini
);