2 * Packet matching code for ARP packets.
4 * Based heavily, if not almost entirely, upon ip_tables.c framework.
6 * Some ARP specific bits are:
8 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
9 * Copyright (C) 2006-2009 Patrick McHardy <kaber@trash.net>
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/capability.h>
17 #include <linux/if_arp.h>
18 #include <linux/kmod.h>
19 #include <linux/vmalloc.h>
20 #include <linux/proc_fs.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/mutex.h>
24 #include <linux/err.h>
25 #include <net/compat.h>
27 #include <linux/uaccess.h>
29 #include <linux/netfilter/x_tables.h>
30 #include <linux/netfilter_arp/arp_tables.h>
31 #include "../../netfilter/xt_repldata.h"
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
35 MODULE_DESCRIPTION("arptables core");
37 void *arpt_alloc_initial_table(const struct xt_table
*info
)
39 return xt_alloc_initial_table(arpt
, ARPT
);
41 EXPORT_SYMBOL_GPL(arpt_alloc_initial_table
);
43 static inline int arp_devaddr_compare(const struct arpt_devaddr_info
*ap
,
44 const char *hdr_addr
, int len
)
48 if (len
> ARPT_DEV_ADDR_LEN_MAX
)
49 len
= ARPT_DEV_ADDR_LEN_MAX
;
52 for (i
= 0; i
< len
; i
++)
53 ret
|= (hdr_addr
[i
] ^ ap
->addr
[i
]) & ap
->mask
[i
];
59 * Unfortunately, _b and _mask are not aligned to an int (or long int)
60 * Some arches dont care, unrolling the loop is a win on them.
61 * For other arches, we only have a 16bit alignement.
63 static unsigned long ifname_compare(const char *_a
, const char *_b
, const char *_mask
)
65 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
66 unsigned long ret
= ifname_compare_aligned(_a
, _b
, _mask
);
68 unsigned long ret
= 0;
69 const u16
*a
= (const u16
*)_a
;
70 const u16
*b
= (const u16
*)_b
;
71 const u16
*mask
= (const u16
*)_mask
;
74 for (i
= 0; i
< IFNAMSIZ
/sizeof(u16
); i
++)
75 ret
|= (a
[i
] ^ b
[i
]) & mask
[i
];
80 /* Returns whether packet matches rule or not. */
81 static inline int arp_packet_match(const struct arphdr
*arphdr
,
82 struct net_device
*dev
,
85 const struct arpt_arp
*arpinfo
)
87 const char *arpptr
= (char *)(arphdr
+ 1);
88 const char *src_devaddr
, *tgt_devaddr
;
89 __be32 src_ipaddr
, tgt_ipaddr
;
92 if (NF_INVF(arpinfo
, ARPT_INV_ARPOP
,
93 (arphdr
->ar_op
& arpinfo
->arpop_mask
) != arpinfo
->arpop
))
96 if (NF_INVF(arpinfo
, ARPT_INV_ARPHRD
,
97 (arphdr
->ar_hrd
& arpinfo
->arhrd_mask
) != arpinfo
->arhrd
))
100 if (NF_INVF(arpinfo
, ARPT_INV_ARPPRO
,
101 (arphdr
->ar_pro
& arpinfo
->arpro_mask
) != arpinfo
->arpro
))
104 if (NF_INVF(arpinfo
, ARPT_INV_ARPHLN
,
105 (arphdr
->ar_hln
& arpinfo
->arhln_mask
) != arpinfo
->arhln
))
108 src_devaddr
= arpptr
;
109 arpptr
+= dev
->addr_len
;
110 memcpy(&src_ipaddr
, arpptr
, sizeof(u32
));
111 arpptr
+= sizeof(u32
);
112 tgt_devaddr
= arpptr
;
113 arpptr
+= dev
->addr_len
;
114 memcpy(&tgt_ipaddr
, arpptr
, sizeof(u32
));
116 if (NF_INVF(arpinfo
, ARPT_INV_SRCDEVADDR
,
117 arp_devaddr_compare(&arpinfo
->src_devaddr
, src_devaddr
,
119 NF_INVF(arpinfo
, ARPT_INV_TGTDEVADDR
,
120 arp_devaddr_compare(&arpinfo
->tgt_devaddr
, tgt_devaddr
,
124 if (NF_INVF(arpinfo
, ARPT_INV_SRCIP
,
125 (src_ipaddr
& arpinfo
->smsk
.s_addr
) != arpinfo
->src
.s_addr
) ||
126 NF_INVF(arpinfo
, ARPT_INV_TGTIP
,
127 (tgt_ipaddr
& arpinfo
->tmsk
.s_addr
) != arpinfo
->tgt
.s_addr
))
130 /* Look for ifname matches. */
131 ret
= ifname_compare(indev
, arpinfo
->iniface
, arpinfo
->iniface_mask
);
133 if (NF_INVF(arpinfo
, ARPT_INV_VIA_IN
, ret
!= 0))
136 ret
= ifname_compare(outdev
, arpinfo
->outiface
, arpinfo
->outiface_mask
);
138 if (NF_INVF(arpinfo
, ARPT_INV_VIA_OUT
, ret
!= 0))
144 static inline int arp_checkentry(const struct arpt_arp
*arp
)
146 if (arp
->flags
& ~ARPT_F_MASK
)
148 if (arp
->invflags
& ~ARPT_INV_MASK
)
155 arpt_error(struct sk_buff
*skb
, const struct xt_action_param
*par
)
157 net_err_ratelimited("arp_tables: error: '%s'\n",
158 (const char *)par
->targinfo
);
163 static inline const struct xt_entry_target
*
164 arpt_get_target_c(const struct arpt_entry
*e
)
166 return arpt_get_target((struct arpt_entry
*)e
);
169 static inline struct arpt_entry
*
170 get_entry(const void *base
, unsigned int offset
)
172 return (struct arpt_entry
*)(base
+ offset
);
176 struct arpt_entry
*arpt_next_entry(const struct arpt_entry
*entry
)
178 return (void *)entry
+ entry
->next_offset
;
181 unsigned int arpt_do_table(struct sk_buff
*skb
,
182 const struct nf_hook_state
*state
,
183 struct xt_table
*table
)
185 unsigned int hook
= state
->hook
;
186 static const char nulldevname
[IFNAMSIZ
] __attribute__((aligned(sizeof(long))));
187 unsigned int verdict
= NF_DROP
;
188 const struct arphdr
*arp
;
189 struct arpt_entry
*e
, **jumpstack
;
190 const char *indev
, *outdev
;
191 const void *table_base
;
192 unsigned int cpu
, stackidx
= 0;
193 const struct xt_table_info
*private;
194 struct xt_action_param acpar
;
197 if (!pskb_may_pull(skb
, arp_hdr_len(skb
->dev
)))
200 indev
= state
->in
? state
->in
->name
: nulldevname
;
201 outdev
= state
->out
? state
->out
->name
: nulldevname
;
204 addend
= xt_write_recseq_begin();
205 private = READ_ONCE(table
->private); /* Address dependency. */
206 cpu
= smp_processor_id();
207 table_base
= private->entries
;
208 jumpstack
= (struct arpt_entry
**)private->jumpstack
[cpu
];
210 /* No TEE support for arptables, so no need to switch to alternate
211 * stack. All targets that reenter must return absolute verdicts.
213 e
= get_entry(table_base
, private->hook_entry
[hook
]);
216 acpar
.hotdrop
= false;
220 const struct xt_entry_target
*t
;
221 struct xt_counters
*counter
;
223 if (!arp_packet_match(arp
, skb
->dev
, indev
, outdev
, &e
->arp
)) {
224 e
= arpt_next_entry(e
);
228 counter
= xt_get_this_cpu_counter(&e
->counters
);
229 ADD_COUNTER(*counter
, arp_hdr_len(skb
->dev
), 1);
231 t
= arpt_get_target_c(e
);
233 /* Standard target? */
234 if (!t
->u
.kernel
.target
->target
) {
237 v
= ((struct xt_standard_target
*)t
)->verdict
;
239 /* Pop from stack? */
240 if (v
!= XT_RETURN
) {
241 verdict
= (unsigned int)(-v
) - 1;
245 e
= get_entry(table_base
,
246 private->underflow
[hook
]);
248 e
= jumpstack
[--stackidx
];
249 e
= arpt_next_entry(e
);
254 != arpt_next_entry(e
)) {
255 if (unlikely(stackidx
>= private->stacksize
)) {
259 jumpstack
[stackidx
++] = e
;
262 e
= get_entry(table_base
, v
);
266 acpar
.target
= t
->u
.kernel
.target
;
267 acpar
.targinfo
= t
->data
;
268 verdict
= t
->u
.kernel
.target
->target(skb
, &acpar
);
270 if (verdict
== XT_CONTINUE
) {
271 /* Target might have changed stuff. */
273 e
= arpt_next_entry(e
);
278 } while (!acpar
.hotdrop
);
279 xt_write_recseq_end(addend
);
288 /* All zeroes == unconditional rule. */
289 static inline bool unconditional(const struct arpt_entry
*e
)
291 static const struct arpt_arp uncond
;
293 return e
->target_offset
== sizeof(struct arpt_entry
) &&
294 memcmp(&e
->arp
, &uncond
, sizeof(uncond
)) == 0;
297 /* Figures out from what hook each rule can be called: returns 0 if
298 * there are loops. Puts hook bitmask in comefrom.
300 static int mark_source_chains(const struct xt_table_info
*newinfo
,
301 unsigned int valid_hooks
, void *entry0
,
302 unsigned int *offsets
)
306 /* No recursion; use packet counter to save back ptrs (reset
307 * to 0 as we leave), and comefrom to save source hook bitmask.
309 for (hook
= 0; hook
< NF_ARP_NUMHOOKS
; hook
++) {
310 unsigned int pos
= newinfo
->hook_entry
[hook
];
311 struct arpt_entry
*e
= entry0
+ pos
;
313 if (!(valid_hooks
& (1 << hook
)))
316 /* Set initial back pointer. */
317 e
->counters
.pcnt
= pos
;
320 const struct xt_standard_target
*t
321 = (void *)arpt_get_target_c(e
);
322 int visited
= e
->comefrom
& (1 << hook
);
324 if (e
->comefrom
& (1 << NF_ARP_NUMHOOKS
))
328 |= ((1 << hook
) | (1 << NF_ARP_NUMHOOKS
));
330 /* Unconditional return/END. */
331 if ((unconditional(e
) &&
332 (strcmp(t
->target
.u
.user
.name
,
333 XT_STANDARD_TARGET
) == 0) &&
334 t
->verdict
< 0) || visited
) {
335 unsigned int oldpos
, size
;
337 /* Return: backtrack through the last
341 e
->comefrom
^= (1<<NF_ARP_NUMHOOKS
);
343 pos
= e
->counters
.pcnt
;
344 e
->counters
.pcnt
= 0;
346 /* We're at the start. */
351 } while (oldpos
== pos
+ e
->next_offset
);
354 size
= e
->next_offset
;
355 e
= entry0
+ pos
+ size
;
356 if (pos
+ size
>= newinfo
->size
)
358 e
->counters
.pcnt
= pos
;
361 int newpos
= t
->verdict
;
363 if (strcmp(t
->target
.u
.user
.name
,
364 XT_STANDARD_TARGET
) == 0 &&
366 /* This a jump; chase it. */
367 if (!xt_find_jump_offset(offsets
, newpos
,
371 /* ... this is a fallthru */
372 newpos
= pos
+ e
->next_offset
;
373 if (newpos
>= newinfo
->size
)
377 e
->counters
.pcnt
= pos
;
386 static inline int check_target(struct arpt_entry
*e
, const char *name
)
388 struct xt_entry_target
*t
= arpt_get_target(e
);
389 struct xt_tgchk_param par
= {
392 .target
= t
->u
.kernel
.target
,
394 .hook_mask
= e
->comefrom
,
395 .family
= NFPROTO_ARP
,
398 return xt_check_target(&par
, t
->u
.target_size
- sizeof(*t
), 0, false);
402 find_check_entry(struct arpt_entry
*e
, const char *name
, unsigned int size
,
403 struct xt_percpu_counter_alloc_state
*alloc_state
)
405 struct xt_entry_target
*t
;
406 struct xt_target
*target
;
409 if (!xt_percpu_counter_alloc(alloc_state
, &e
->counters
))
412 t
= arpt_get_target(e
);
413 target
= xt_request_find_target(NFPROTO_ARP
, t
->u
.user
.name
,
415 if (IS_ERR(target
)) {
416 ret
= PTR_ERR(target
);
419 t
->u
.kernel
.target
= target
;
421 ret
= check_target(e
, name
);
426 module_put(t
->u
.kernel
.target
->me
);
428 xt_percpu_counter_free(&e
->counters
);
433 static bool check_underflow(const struct arpt_entry
*e
)
435 const struct xt_entry_target
*t
;
436 unsigned int verdict
;
438 if (!unconditional(e
))
440 t
= arpt_get_target_c(e
);
441 if (strcmp(t
->u
.user
.name
, XT_STANDARD_TARGET
) != 0)
443 verdict
= ((struct xt_standard_target
*)t
)->verdict
;
444 verdict
= -verdict
- 1;
445 return verdict
== NF_DROP
|| verdict
== NF_ACCEPT
;
448 static inline int check_entry_size_and_hooks(struct arpt_entry
*e
,
449 struct xt_table_info
*newinfo
,
450 const unsigned char *base
,
451 const unsigned char *limit
,
452 const unsigned int *hook_entries
,
453 const unsigned int *underflows
,
454 unsigned int valid_hooks
)
459 if ((unsigned long)e
% __alignof__(struct arpt_entry
) != 0 ||
460 (unsigned char *)e
+ sizeof(struct arpt_entry
) >= limit
||
461 (unsigned char *)e
+ e
->next_offset
> limit
)
465 < sizeof(struct arpt_entry
) + sizeof(struct xt_entry_target
))
468 if (!arp_checkentry(&e
->arp
))
471 err
= xt_check_entry_offsets(e
, e
->elems
, e
->target_offset
,
476 /* Check hooks & underflows */
477 for (h
= 0; h
< NF_ARP_NUMHOOKS
; h
++) {
478 if (!(valid_hooks
& (1 << h
)))
480 if ((unsigned char *)e
- base
== hook_entries
[h
])
481 newinfo
->hook_entry
[h
] = hook_entries
[h
];
482 if ((unsigned char *)e
- base
== underflows
[h
]) {
483 if (!check_underflow(e
))
486 newinfo
->underflow
[h
] = underflows
[h
];
490 /* Clear counters and comefrom */
491 e
->counters
= ((struct xt_counters
) { 0, 0 });
496 static inline void cleanup_entry(struct arpt_entry
*e
)
498 struct xt_tgdtor_param par
;
499 struct xt_entry_target
*t
;
501 t
= arpt_get_target(e
);
502 par
.target
= t
->u
.kernel
.target
;
503 par
.targinfo
= t
->data
;
504 par
.family
= NFPROTO_ARP
;
505 if (par
.target
->destroy
!= NULL
)
506 par
.target
->destroy(&par
);
507 module_put(par
.target
->me
);
508 xt_percpu_counter_free(&e
->counters
);
511 /* Checks and translates the user-supplied table segment (held in
514 static int translate_table(struct xt_table_info
*newinfo
, void *entry0
,
515 const struct arpt_replace
*repl
)
517 struct xt_percpu_counter_alloc_state alloc_state
= { 0 };
518 struct arpt_entry
*iter
;
519 unsigned int *offsets
;
523 newinfo
->size
= repl
->size
;
524 newinfo
->number
= repl
->num_entries
;
526 /* Init all hooks to impossible value. */
527 for (i
= 0; i
< NF_ARP_NUMHOOKS
; i
++) {
528 newinfo
->hook_entry
[i
] = 0xFFFFFFFF;
529 newinfo
->underflow
[i
] = 0xFFFFFFFF;
532 offsets
= xt_alloc_entry_offsets(newinfo
->number
);
537 /* Walk through entries, checking offsets. */
538 xt_entry_foreach(iter
, entry0
, newinfo
->size
) {
539 ret
= check_entry_size_and_hooks(iter
, newinfo
, entry0
,
546 if (i
< repl
->num_entries
)
547 offsets
[i
] = (void *)iter
- entry0
;
549 if (strcmp(arpt_get_target(iter
)->u
.user
.name
,
550 XT_ERROR_TARGET
) == 0)
551 ++newinfo
->stacksize
;
555 if (i
!= repl
->num_entries
)
558 ret
= xt_check_table_hooks(newinfo
, repl
->valid_hooks
);
562 if (!mark_source_chains(newinfo
, repl
->valid_hooks
, entry0
, offsets
)) {
568 /* Finally, each sanity check must pass */
570 xt_entry_foreach(iter
, entry0
, newinfo
->size
) {
571 ret
= find_check_entry(iter
, repl
->name
, repl
->size
,
579 xt_entry_foreach(iter
, entry0
, newinfo
->size
) {
593 static void get_counters(const struct xt_table_info
*t
,
594 struct xt_counters counters
[])
596 struct arpt_entry
*iter
;
600 for_each_possible_cpu(cpu
) {
601 seqcount_t
*s
= &per_cpu(xt_recseq
, cpu
);
604 xt_entry_foreach(iter
, t
->entries
, t
->size
) {
605 struct xt_counters
*tmp
;
609 tmp
= xt_get_per_cpu_counter(&iter
->counters
, cpu
);
611 start
= read_seqcount_begin(s
);
614 } while (read_seqcount_retry(s
, start
));
616 ADD_COUNTER(counters
[i
], bcnt
, pcnt
);
623 static void get_old_counters(const struct xt_table_info
*t
,
624 struct xt_counters counters
[])
626 struct arpt_entry
*iter
;
629 for_each_possible_cpu(cpu
) {
631 xt_entry_foreach(iter
, t
->entries
, t
->size
) {
632 struct xt_counters
*tmp
;
634 tmp
= xt_get_per_cpu_counter(&iter
->counters
, cpu
);
635 ADD_COUNTER(counters
[i
], tmp
->bcnt
, tmp
->pcnt
);
642 static struct xt_counters
*alloc_counters(const struct xt_table
*table
)
644 unsigned int countersize
;
645 struct xt_counters
*counters
;
646 const struct xt_table_info
*private = table
->private;
648 /* We need atomic snapshot of counters: rest doesn't change
649 * (other than comefrom, which userspace doesn't care
652 countersize
= sizeof(struct xt_counters
) * private->number
;
653 counters
= vzalloc(countersize
);
655 if (counters
== NULL
)
656 return ERR_PTR(-ENOMEM
);
658 get_counters(private, counters
);
663 static int copy_entries_to_user(unsigned int total_size
,
664 const struct xt_table
*table
,
665 void __user
*userptr
)
667 unsigned int off
, num
;
668 const struct arpt_entry
*e
;
669 struct xt_counters
*counters
;
670 struct xt_table_info
*private = table
->private;
674 counters
= alloc_counters(table
);
675 if (IS_ERR(counters
))
676 return PTR_ERR(counters
);
678 loc_cpu_entry
= private->entries
;
680 /* FIXME: use iterator macros --RR */
681 /* ... then go back and fix counters and names */
682 for (off
= 0, num
= 0; off
< total_size
; off
+= e
->next_offset
, num
++){
683 const struct xt_entry_target
*t
;
685 e
= loc_cpu_entry
+ off
;
686 if (copy_to_user(userptr
+ off
, e
, sizeof(*e
))) {
690 if (copy_to_user(userptr
+ off
691 + offsetof(struct arpt_entry
, counters
),
693 sizeof(counters
[num
])) != 0) {
698 t
= arpt_get_target_c(e
);
699 if (xt_target_to_user(t
, userptr
+ off
+ e
->target_offset
)) {
711 static void compat_standard_from_user(void *dst
, const void *src
)
713 int v
= *(compat_int_t
*)src
;
716 v
+= xt_compat_calc_jump(NFPROTO_ARP
, v
);
717 memcpy(dst
, &v
, sizeof(v
));
720 static int compat_standard_to_user(void __user
*dst
, const void *src
)
722 compat_int_t cv
= *(int *)src
;
725 cv
-= xt_compat_calc_jump(NFPROTO_ARP
, cv
);
726 return copy_to_user(dst
, &cv
, sizeof(cv
)) ? -EFAULT
: 0;
729 static int compat_calc_entry(const struct arpt_entry
*e
,
730 const struct xt_table_info
*info
,
731 const void *base
, struct xt_table_info
*newinfo
)
733 const struct xt_entry_target
*t
;
734 unsigned int entry_offset
;
737 off
= sizeof(struct arpt_entry
) - sizeof(struct compat_arpt_entry
);
738 entry_offset
= (void *)e
- base
;
740 t
= arpt_get_target_c(e
);
741 off
+= xt_compat_target_offset(t
->u
.kernel
.target
);
742 newinfo
->size
-= off
;
743 ret
= xt_compat_add_offset(NFPROTO_ARP
, entry_offset
, off
);
747 for (i
= 0; i
< NF_ARP_NUMHOOKS
; i
++) {
748 if (info
->hook_entry
[i
] &&
749 (e
< (struct arpt_entry
*)(base
+ info
->hook_entry
[i
])))
750 newinfo
->hook_entry
[i
] -= off
;
751 if (info
->underflow
[i
] &&
752 (e
< (struct arpt_entry
*)(base
+ info
->underflow
[i
])))
753 newinfo
->underflow
[i
] -= off
;
758 static int compat_table_info(const struct xt_table_info
*info
,
759 struct xt_table_info
*newinfo
)
761 struct arpt_entry
*iter
;
762 const void *loc_cpu_entry
;
765 if (!newinfo
|| !info
)
768 /* we dont care about newinfo->entries */
769 memcpy(newinfo
, info
, offsetof(struct xt_table_info
, entries
));
770 newinfo
->initial_entries
= 0;
771 loc_cpu_entry
= info
->entries
;
772 ret
= xt_compat_init_offsets(NFPROTO_ARP
, info
->number
);
775 xt_entry_foreach(iter
, loc_cpu_entry
, info
->size
) {
776 ret
= compat_calc_entry(iter
, info
, loc_cpu_entry
, newinfo
);
784 static int get_info(struct net
*net
, void __user
*user
,
785 const int *len
, int compat
)
787 char name
[XT_TABLE_MAXNAMELEN
];
791 if (*len
!= sizeof(struct arpt_getinfo
))
794 if (copy_from_user(name
, user
, sizeof(name
)) != 0)
797 name
[XT_TABLE_MAXNAMELEN
-1] = '\0';
800 xt_compat_lock(NFPROTO_ARP
);
802 t
= xt_request_find_table_lock(net
, NFPROTO_ARP
, name
);
804 struct arpt_getinfo info
;
805 const struct xt_table_info
*private = t
->private;
807 struct xt_table_info tmp
;
810 ret
= compat_table_info(private, &tmp
);
811 xt_compat_flush_offsets(NFPROTO_ARP
);
815 memset(&info
, 0, sizeof(info
));
816 info
.valid_hooks
= t
->valid_hooks
;
817 memcpy(info
.hook_entry
, private->hook_entry
,
818 sizeof(info
.hook_entry
));
819 memcpy(info
.underflow
, private->underflow
,
820 sizeof(info
.underflow
));
821 info
.num_entries
= private->number
;
822 info
.size
= private->size
;
823 strcpy(info
.name
, name
);
825 if (copy_to_user(user
, &info
, *len
) != 0)
835 xt_compat_unlock(NFPROTO_ARP
);
840 static int get_entries(struct net
*net
, struct arpt_get_entries __user
*uptr
,
844 struct arpt_get_entries get
;
847 if (*len
< sizeof(get
))
849 if (copy_from_user(&get
, uptr
, sizeof(get
)) != 0)
851 if (*len
!= sizeof(struct arpt_get_entries
) + get
.size
)
854 get
.name
[sizeof(get
.name
) - 1] = '\0';
856 t
= xt_find_table_lock(net
, NFPROTO_ARP
, get
.name
);
858 const struct xt_table_info
*private = t
->private;
860 if (get
.size
== private->size
)
861 ret
= copy_entries_to_user(private->size
,
862 t
, uptr
->entrytable
);
874 static int __do_replace(struct net
*net
, const char *name
,
875 unsigned int valid_hooks
,
876 struct xt_table_info
*newinfo
,
877 unsigned int num_counters
,
878 void __user
*counters_ptr
)
882 struct xt_table_info
*oldinfo
;
883 struct xt_counters
*counters
;
884 void *loc_cpu_old_entry
;
885 struct arpt_entry
*iter
;
888 counters
= xt_counters_alloc(num_counters
);
894 t
= xt_request_find_table_lock(net
, NFPROTO_ARP
, name
);
897 goto free_newinfo_counters_untrans
;
901 if (valid_hooks
!= t
->valid_hooks
) {
906 oldinfo
= xt_replace_table(t
, num_counters
, newinfo
, &ret
);
910 /* Update module usage count based on number of rules */
911 if ((oldinfo
->number
> oldinfo
->initial_entries
) ||
912 (newinfo
->number
<= oldinfo
->initial_entries
))
914 if ((oldinfo
->number
> oldinfo
->initial_entries
) &&
915 (newinfo
->number
<= oldinfo
->initial_entries
))
920 get_old_counters(oldinfo
, counters
);
922 /* Decrease module usage counts and free resource */
923 loc_cpu_old_entry
= oldinfo
->entries
;
924 xt_entry_foreach(iter
, loc_cpu_old_entry
, oldinfo
->size
)
927 xt_free_table_info(oldinfo
);
928 if (copy_to_user(counters_ptr
, counters
,
929 sizeof(struct xt_counters
) * num_counters
) != 0) {
930 /* Silent error, can't fail, new table is already in place */
931 net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n");
939 free_newinfo_counters_untrans
:
945 static int do_replace(struct net
*net
, const void __user
*user
,
949 struct arpt_replace tmp
;
950 struct xt_table_info
*newinfo
;
952 struct arpt_entry
*iter
;
954 if (copy_from_user(&tmp
, user
, sizeof(tmp
)) != 0)
958 if (tmp
.num_counters
>= INT_MAX
/ sizeof(struct xt_counters
))
960 if (tmp
.num_counters
== 0)
963 tmp
.name
[sizeof(tmp
.name
)-1] = 0;
965 newinfo
= xt_alloc_table_info(tmp
.size
);
969 loc_cpu_entry
= newinfo
->entries
;
970 if (copy_from_user(loc_cpu_entry
, user
+ sizeof(tmp
),
976 ret
= translate_table(newinfo
, loc_cpu_entry
, &tmp
);
980 ret
= __do_replace(net
, tmp
.name
, tmp
.valid_hooks
, newinfo
,
981 tmp
.num_counters
, tmp
.counters
);
983 goto free_newinfo_untrans
;
986 free_newinfo_untrans
:
987 xt_entry_foreach(iter
, loc_cpu_entry
, newinfo
->size
)
990 xt_free_table_info(newinfo
);
994 static int do_add_counters(struct net
*net
, const void __user
*user
,
995 unsigned int len
, int compat
)
998 struct xt_counters_info tmp
;
999 struct xt_counters
*paddc
;
1001 const struct xt_table_info
*private;
1003 struct arpt_entry
*iter
;
1004 unsigned int addend
;
1006 paddc
= xt_copy_counters_from_user(user
, len
, &tmp
, compat
);
1008 return PTR_ERR(paddc
);
1010 t
= xt_find_table_lock(net
, NFPROTO_ARP
, tmp
.name
);
1017 private = t
->private;
1018 if (private->number
!= tmp
.num_counters
) {
1020 goto unlock_up_free
;
1025 addend
= xt_write_recseq_begin();
1026 xt_entry_foreach(iter
, private->entries
, private->size
) {
1027 struct xt_counters
*tmp
;
1029 tmp
= xt_get_this_cpu_counter(&iter
->counters
);
1030 ADD_COUNTER(*tmp
, paddc
[i
].bcnt
, paddc
[i
].pcnt
);
1033 xt_write_recseq_end(addend
);
1044 #ifdef CONFIG_COMPAT
1045 struct compat_arpt_replace
{
1046 char name
[XT_TABLE_MAXNAMELEN
];
1050 u32 hook_entry
[NF_ARP_NUMHOOKS
];
1051 u32 underflow
[NF_ARP_NUMHOOKS
];
1053 compat_uptr_t counters
;
1054 struct compat_arpt_entry entries
[0];
1057 static inline void compat_release_entry(struct compat_arpt_entry
*e
)
1059 struct xt_entry_target
*t
;
1061 t
= compat_arpt_get_target(e
);
1062 module_put(t
->u
.kernel
.target
->me
);
1066 check_compat_entry_size_and_hooks(struct compat_arpt_entry
*e
,
1067 struct xt_table_info
*newinfo
,
1069 const unsigned char *base
,
1070 const unsigned char *limit
)
1072 struct xt_entry_target
*t
;
1073 struct xt_target
*target
;
1074 unsigned int entry_offset
;
1077 if ((unsigned long)e
% __alignof__(struct compat_arpt_entry
) != 0 ||
1078 (unsigned char *)e
+ sizeof(struct compat_arpt_entry
) >= limit
||
1079 (unsigned char *)e
+ e
->next_offset
> limit
)
1082 if (e
->next_offset
< sizeof(struct compat_arpt_entry
) +
1083 sizeof(struct compat_xt_entry_target
))
1086 if (!arp_checkentry(&e
->arp
))
1089 ret
= xt_compat_check_entry_offsets(e
, e
->elems
, e
->target_offset
,
1094 off
= sizeof(struct arpt_entry
) - sizeof(struct compat_arpt_entry
);
1095 entry_offset
= (void *)e
- (void *)base
;
1097 t
= compat_arpt_get_target(e
);
1098 target
= xt_request_find_target(NFPROTO_ARP
, t
->u
.user
.name
,
1099 t
->u
.user
.revision
);
1100 if (IS_ERR(target
)) {
1101 ret
= PTR_ERR(target
);
1104 t
->u
.kernel
.target
= target
;
1106 off
+= xt_compat_target_offset(target
);
1108 ret
= xt_compat_add_offset(NFPROTO_ARP
, entry_offset
, off
);
1110 goto release_target
;
1115 module_put(t
->u
.kernel
.target
->me
);
1121 compat_copy_entry_from_user(struct compat_arpt_entry
*e
, void **dstptr
,
1123 struct xt_table_info
*newinfo
, unsigned char *base
)
1125 struct xt_entry_target
*t
;
1126 struct arpt_entry
*de
;
1127 unsigned int origsize
;
1132 memcpy(de
, e
, sizeof(struct arpt_entry
));
1133 memcpy(&de
->counters
, &e
->counters
, sizeof(e
->counters
));
1135 *dstptr
+= sizeof(struct arpt_entry
);
1136 *size
+= sizeof(struct arpt_entry
) - sizeof(struct compat_arpt_entry
);
1138 de
->target_offset
= e
->target_offset
- (origsize
- *size
);
1139 t
= compat_arpt_get_target(e
);
1140 xt_compat_target_from_user(t
, dstptr
, size
);
1142 de
->next_offset
= e
->next_offset
- (origsize
- *size
);
1143 for (h
= 0; h
< NF_ARP_NUMHOOKS
; h
++) {
1144 if ((unsigned char *)de
- base
< newinfo
->hook_entry
[h
])
1145 newinfo
->hook_entry
[h
] -= origsize
- *size
;
1146 if ((unsigned char *)de
- base
< newinfo
->underflow
[h
])
1147 newinfo
->underflow
[h
] -= origsize
- *size
;
1151 static int translate_compat_table(struct xt_table_info
**pinfo
,
1153 const struct compat_arpt_replace
*compatr
)
1156 struct xt_table_info
*newinfo
, *info
;
1157 void *pos
, *entry0
, *entry1
;
1158 struct compat_arpt_entry
*iter0
;
1159 struct arpt_replace repl
;
1165 size
= compatr
->size
;
1166 info
->number
= compatr
->num_entries
;
1169 xt_compat_lock(NFPROTO_ARP
);
1170 ret
= xt_compat_init_offsets(NFPROTO_ARP
, compatr
->num_entries
);
1173 /* Walk through entries, checking offsets. */
1174 xt_entry_foreach(iter0
, entry0
, compatr
->size
) {
1175 ret
= check_compat_entry_size_and_hooks(iter0
, info
, &size
,
1177 entry0
+ compatr
->size
);
1184 if (j
!= compatr
->num_entries
)
1188 newinfo
= xt_alloc_table_info(size
);
1192 newinfo
->number
= compatr
->num_entries
;
1193 for (i
= 0; i
< NF_ARP_NUMHOOKS
; i
++) {
1194 newinfo
->hook_entry
[i
] = compatr
->hook_entry
[i
];
1195 newinfo
->underflow
[i
] = compatr
->underflow
[i
];
1197 entry1
= newinfo
->entries
;
1199 size
= compatr
->size
;
1200 xt_entry_foreach(iter0
, entry0
, compatr
->size
)
1201 compat_copy_entry_from_user(iter0
, &pos
, &size
,
1204 /* all module references in entry0 are now gone */
1206 xt_compat_flush_offsets(NFPROTO_ARP
);
1207 xt_compat_unlock(NFPROTO_ARP
);
1209 memcpy(&repl
, compatr
, sizeof(*compatr
));
1211 for (i
= 0; i
< NF_ARP_NUMHOOKS
; i
++) {
1212 repl
.hook_entry
[i
] = newinfo
->hook_entry
[i
];
1213 repl
.underflow
[i
] = newinfo
->underflow
[i
];
1216 repl
.num_counters
= 0;
1217 repl
.counters
= NULL
;
1218 repl
.size
= newinfo
->size
;
1219 ret
= translate_table(newinfo
, entry1
, &repl
);
1225 xt_free_table_info(info
);
1229 xt_free_table_info(newinfo
);
1232 xt_compat_flush_offsets(NFPROTO_ARP
);
1233 xt_compat_unlock(NFPROTO_ARP
);
1234 xt_entry_foreach(iter0
, entry0
, compatr
->size
) {
1237 compat_release_entry(iter0
);
1242 static int compat_do_replace(struct net
*net
, void __user
*user
,
1246 struct compat_arpt_replace tmp
;
1247 struct xt_table_info
*newinfo
;
1248 void *loc_cpu_entry
;
1249 struct arpt_entry
*iter
;
1251 if (copy_from_user(&tmp
, user
, sizeof(tmp
)) != 0)
1254 /* overflow check */
1255 if (tmp
.num_counters
>= INT_MAX
/ sizeof(struct xt_counters
))
1257 if (tmp
.num_counters
== 0)
1260 tmp
.name
[sizeof(tmp
.name
)-1] = 0;
1262 newinfo
= xt_alloc_table_info(tmp
.size
);
1266 loc_cpu_entry
= newinfo
->entries
;
1267 if (copy_from_user(loc_cpu_entry
, user
+ sizeof(tmp
), tmp
.size
) != 0) {
1272 ret
= translate_compat_table(&newinfo
, &loc_cpu_entry
, &tmp
);
1276 ret
= __do_replace(net
, tmp
.name
, tmp
.valid_hooks
, newinfo
,
1277 tmp
.num_counters
, compat_ptr(tmp
.counters
));
1279 goto free_newinfo_untrans
;
1282 free_newinfo_untrans
:
1283 xt_entry_foreach(iter
, loc_cpu_entry
, newinfo
->size
)
1284 cleanup_entry(iter
);
1286 xt_free_table_info(newinfo
);
1290 static int compat_do_arpt_set_ctl(struct sock
*sk
, int cmd
, void __user
*user
,
1295 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
))
1299 case ARPT_SO_SET_REPLACE
:
1300 ret
= compat_do_replace(sock_net(sk
), user
, len
);
1303 case ARPT_SO_SET_ADD_COUNTERS
:
1304 ret
= do_add_counters(sock_net(sk
), user
, len
, 1);
1314 static int compat_copy_entry_to_user(struct arpt_entry
*e
, void __user
**dstptr
,
1315 compat_uint_t
*size
,
1316 struct xt_counters
*counters
,
1319 struct xt_entry_target
*t
;
1320 struct compat_arpt_entry __user
*ce
;
1321 u_int16_t target_offset
, next_offset
;
1322 compat_uint_t origsize
;
1327 if (copy_to_user(ce
, e
, sizeof(struct arpt_entry
)) != 0 ||
1328 copy_to_user(&ce
->counters
, &counters
[i
],
1329 sizeof(counters
[i
])) != 0)
1332 *dstptr
+= sizeof(struct compat_arpt_entry
);
1333 *size
-= sizeof(struct arpt_entry
) - sizeof(struct compat_arpt_entry
);
1335 target_offset
= e
->target_offset
- (origsize
- *size
);
1337 t
= arpt_get_target(e
);
1338 ret
= xt_compat_target_to_user(t
, dstptr
, size
);
1341 next_offset
= e
->next_offset
- (origsize
- *size
);
1342 if (put_user(target_offset
, &ce
->target_offset
) != 0 ||
1343 put_user(next_offset
, &ce
->next_offset
) != 0)
1348 static int compat_copy_entries_to_user(unsigned int total_size
,
1349 struct xt_table
*table
,
1350 void __user
*userptr
)
1352 struct xt_counters
*counters
;
1353 const struct xt_table_info
*private = table
->private;
1358 struct arpt_entry
*iter
;
1360 counters
= alloc_counters(table
);
1361 if (IS_ERR(counters
))
1362 return PTR_ERR(counters
);
1366 xt_entry_foreach(iter
, private->entries
, total_size
) {
1367 ret
= compat_copy_entry_to_user(iter
, &pos
,
1368 &size
, counters
, i
++);
1376 struct compat_arpt_get_entries
{
1377 char name
[XT_TABLE_MAXNAMELEN
];
1379 struct compat_arpt_entry entrytable
[0];
1382 static int compat_get_entries(struct net
*net
,
1383 struct compat_arpt_get_entries __user
*uptr
,
1387 struct compat_arpt_get_entries get
;
1390 if (*len
< sizeof(get
))
1392 if (copy_from_user(&get
, uptr
, sizeof(get
)) != 0)
1394 if (*len
!= sizeof(struct compat_arpt_get_entries
) + get
.size
)
1397 get
.name
[sizeof(get
.name
) - 1] = '\0';
1399 xt_compat_lock(NFPROTO_ARP
);
1400 t
= xt_find_table_lock(net
, NFPROTO_ARP
, get
.name
);
1402 const struct xt_table_info
*private = t
->private;
1403 struct xt_table_info info
;
1405 ret
= compat_table_info(private, &info
);
1406 if (!ret
&& get
.size
== info
.size
) {
1407 ret
= compat_copy_entries_to_user(private->size
,
1408 t
, uptr
->entrytable
);
1412 xt_compat_flush_offsets(NFPROTO_ARP
);
1418 xt_compat_unlock(NFPROTO_ARP
);
1422 static int do_arpt_get_ctl(struct sock
*, int, void __user
*, int *);
1424 static int compat_do_arpt_get_ctl(struct sock
*sk
, int cmd
, void __user
*user
,
1429 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
))
1433 case ARPT_SO_GET_INFO
:
1434 ret
= get_info(sock_net(sk
), user
, len
, 1);
1436 case ARPT_SO_GET_ENTRIES
:
1437 ret
= compat_get_entries(sock_net(sk
), user
, len
);
1440 ret
= do_arpt_get_ctl(sk
, cmd
, user
, len
);
1446 static int do_arpt_set_ctl(struct sock
*sk
, int cmd
, void __user
*user
, unsigned int len
)
1450 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
))
1454 case ARPT_SO_SET_REPLACE
:
1455 ret
= do_replace(sock_net(sk
), user
, len
);
1458 case ARPT_SO_SET_ADD_COUNTERS
:
1459 ret
= do_add_counters(sock_net(sk
), user
, len
, 0);
1469 static int do_arpt_get_ctl(struct sock
*sk
, int cmd
, void __user
*user
, int *len
)
1473 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
))
1477 case ARPT_SO_GET_INFO
:
1478 ret
= get_info(sock_net(sk
), user
, len
, 0);
1481 case ARPT_SO_GET_ENTRIES
:
1482 ret
= get_entries(sock_net(sk
), user
, len
);
1485 case ARPT_SO_GET_REVISION_TARGET
: {
1486 struct xt_get_revision rev
;
1488 if (*len
!= sizeof(rev
)) {
1492 if (copy_from_user(&rev
, user
, sizeof(rev
)) != 0) {
1496 rev
.name
[sizeof(rev
.name
)-1] = 0;
1498 try_then_request_module(xt_find_revision(NFPROTO_ARP
, rev
.name
,
1499 rev
.revision
, 1, &ret
),
1500 "arpt_%s", rev
.name
);
1511 static void __arpt_unregister_table(struct xt_table
*table
)
1513 struct xt_table_info
*private;
1514 void *loc_cpu_entry
;
1515 struct module
*table_owner
= table
->me
;
1516 struct arpt_entry
*iter
;
1518 private = xt_unregister_table(table
);
1520 /* Decrease module usage counts and free resources */
1521 loc_cpu_entry
= private->entries
;
1522 xt_entry_foreach(iter
, loc_cpu_entry
, private->size
)
1523 cleanup_entry(iter
);
1524 if (private->number
> private->initial_entries
)
1525 module_put(table_owner
);
1526 xt_free_table_info(private);
1529 int arpt_register_table(struct net
*net
,
1530 const struct xt_table
*table
,
1531 const struct arpt_replace
*repl
,
1532 const struct nf_hook_ops
*ops
,
1533 struct xt_table
**res
)
1536 struct xt_table_info
*newinfo
;
1537 struct xt_table_info bootstrap
= {0};
1538 void *loc_cpu_entry
;
1539 struct xt_table
*new_table
;
1541 newinfo
= xt_alloc_table_info(repl
->size
);
1545 loc_cpu_entry
= newinfo
->entries
;
1546 memcpy(loc_cpu_entry
, repl
->entries
, repl
->size
);
1548 ret
= translate_table(newinfo
, loc_cpu_entry
, repl
);
1552 new_table
= xt_register_table(net
, table
, &bootstrap
, newinfo
);
1553 if (IS_ERR(new_table
)) {
1554 ret
= PTR_ERR(new_table
);
1558 /* set res now, will see skbs right after nf_register_net_hooks */
1559 WRITE_ONCE(*res
, new_table
);
1561 ret
= nf_register_net_hooks(net
, ops
, hweight32(table
->valid_hooks
));
1563 __arpt_unregister_table(new_table
);
1570 xt_free_table_info(newinfo
);
1574 void arpt_unregister_table(struct net
*net
, struct xt_table
*table
,
1575 const struct nf_hook_ops
*ops
)
1577 nf_unregister_net_hooks(net
, ops
, hweight32(table
->valid_hooks
));
1578 __arpt_unregister_table(table
);
1581 /* The built-in targets: standard (NULL) and error. */
1582 static struct xt_target arpt_builtin_tg
[] __read_mostly
= {
1584 .name
= XT_STANDARD_TARGET
,
1585 .targetsize
= sizeof(int),
1586 .family
= NFPROTO_ARP
,
1587 #ifdef CONFIG_COMPAT
1588 .compatsize
= sizeof(compat_int_t
),
1589 .compat_from_user
= compat_standard_from_user
,
1590 .compat_to_user
= compat_standard_to_user
,
1594 .name
= XT_ERROR_TARGET
,
1595 .target
= arpt_error
,
1596 .targetsize
= XT_FUNCTION_MAXNAMELEN
,
1597 .family
= NFPROTO_ARP
,
1601 static struct nf_sockopt_ops arpt_sockopts
= {
1603 .set_optmin
= ARPT_BASE_CTL
,
1604 .set_optmax
= ARPT_SO_SET_MAX
+1,
1605 .set
= do_arpt_set_ctl
,
1606 #ifdef CONFIG_COMPAT
1607 .compat_set
= compat_do_arpt_set_ctl
,
1609 .get_optmin
= ARPT_BASE_CTL
,
1610 .get_optmax
= ARPT_SO_GET_MAX
+1,
1611 .get
= do_arpt_get_ctl
,
1612 #ifdef CONFIG_COMPAT
1613 .compat_get
= compat_do_arpt_get_ctl
,
1615 .owner
= THIS_MODULE
,
1618 static int __net_init
arp_tables_net_init(struct net
*net
)
1620 return xt_proto_init(net
, NFPROTO_ARP
);
1623 static void __net_exit
arp_tables_net_exit(struct net
*net
)
1625 xt_proto_fini(net
, NFPROTO_ARP
);
1628 static struct pernet_operations arp_tables_net_ops
= {
1629 .init
= arp_tables_net_init
,
1630 .exit
= arp_tables_net_exit
,
1633 static int __init
arp_tables_init(void)
1637 ret
= register_pernet_subsys(&arp_tables_net_ops
);
1641 /* No one else will be downing sem now, so we won't sleep */
1642 ret
= xt_register_targets(arpt_builtin_tg
, ARRAY_SIZE(arpt_builtin_tg
));
1646 /* Register setsockopt */
1647 ret
= nf_register_sockopt(&arpt_sockopts
);
1654 xt_unregister_targets(arpt_builtin_tg
, ARRAY_SIZE(arpt_builtin_tg
));
1656 unregister_pernet_subsys(&arp_tables_net_ops
);
1661 static void __exit
arp_tables_fini(void)
1663 nf_unregister_sockopt(&arpt_sockopts
);
1664 xt_unregister_targets(arpt_builtin_tg
, ARRAY_SIZE(arpt_builtin_tg
));
1665 unregister_pernet_subsys(&arp_tables_net_ops
);
1668 EXPORT_SYMBOL(arpt_register_table
);
1669 EXPORT_SYMBOL(arpt_unregister_table
);
1670 EXPORT_SYMBOL(arpt_do_table
);
1672 module_init(arp_tables_init
);
1673 module_exit(arp_tables_fini
);