![Al Viro](/assets/img/avatar_default.png)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
256 lines
7.2 KiB
C
256 lines
7.2 KiB
C
/*
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* Format of an ARP firewall descriptor
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*
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* src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in
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* network byte order.
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* flags are stored in host byte order (of course).
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*/
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#ifndef _ARPTABLES_H
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#define _ARPTABLES_H
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#ifdef __KERNEL__
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#include <linux/if.h>
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#include <linux/types.h>
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#include <linux/in.h>
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#include <linux/if_arp.h>
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#include <linux/skbuff.h>
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#endif
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#include <linux/compiler.h>
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#include <linux/netfilter_arp.h>
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#include <linux/netfilter/x_tables.h>
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#define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
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#define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
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#define arpt_target xt_target
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#define arpt_table xt_table
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#define ARPT_DEV_ADDR_LEN_MAX 16
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struct arpt_devaddr_info {
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char addr[ARPT_DEV_ADDR_LEN_MAX];
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char mask[ARPT_DEV_ADDR_LEN_MAX];
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};
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/* Yes, Virginia, you have to zero the padding. */
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struct arpt_arp {
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/* Source and target IP addr */
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struct in_addr src, tgt;
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/* Mask for src and target IP addr */
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struct in_addr smsk, tmsk;
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/* Device hw address length, src+target device addresses */
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u_int8_t arhln, arhln_mask;
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struct arpt_devaddr_info src_devaddr;
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struct arpt_devaddr_info tgt_devaddr;
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/* ARP operation code. */
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__be16 arpop, arpop_mask;
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/* ARP hardware address and protocol address format. */
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__be16 arhrd, arhrd_mask;
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__be16 arpro, arpro_mask;
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/* The protocol address length is only accepted if it is 4
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* so there is no use in offering a way to do filtering on it.
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*/
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char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
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unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
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/* Flags word */
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u_int8_t flags;
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/* Inverse flags */
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u_int16_t invflags;
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};
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#define arpt_entry_target xt_entry_target
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#define arpt_standard_target xt_standard_target
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/* Values for "flag" field in struct arpt_ip (general arp structure).
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* No flags defined yet.
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*/
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#define ARPT_F_MASK 0x00 /* All possible flag bits mask. */
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/* Values for "inv" field in struct arpt_arp. */
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#define ARPT_INV_VIA_IN 0x0001 /* Invert the sense of IN IFACE. */
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#define ARPT_INV_VIA_OUT 0x0002 /* Invert the sense of OUT IFACE */
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#define ARPT_INV_SRCIP 0x0004 /* Invert the sense of SRC IP. */
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#define ARPT_INV_TGTIP 0x0008 /* Invert the sense of TGT IP. */
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#define ARPT_INV_SRCDEVADDR 0x0010 /* Invert the sense of SRC DEV ADDR. */
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#define ARPT_INV_TGTDEVADDR 0x0020 /* Invert the sense of TGT DEV ADDR. */
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#define ARPT_INV_ARPOP 0x0040 /* Invert the sense of ARP OP. */
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#define ARPT_INV_ARPHRD 0x0080 /* Invert the sense of ARP HRD. */
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#define ARPT_INV_ARPPRO 0x0100 /* Invert the sense of ARP PRO. */
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#define ARPT_INV_ARPHLN 0x0200 /* Invert the sense of ARP HLN. */
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#define ARPT_INV_MASK 0x03FF /* All possible flag bits mask. */
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/* This structure defines each of the firewall rules. Consists of 3
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parts which are 1) general ARP header stuff 2) match specific
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stuff 3) the target to perform if the rule matches */
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struct arpt_entry
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{
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struct arpt_arp arp;
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/* Size of arpt_entry + matches */
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u_int16_t target_offset;
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/* Size of arpt_entry + matches + target */
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u_int16_t next_offset;
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/* Back pointer */
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unsigned int comefrom;
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/* Packet and byte counters. */
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struct xt_counters counters;
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/* The matches (if any), then the target. */
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unsigned char elems[0];
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};
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/*
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* New IP firewall options for [gs]etsockopt at the RAW IP level.
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* Unlike BSD Linux inherits IP options so you don't have to use a raw
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* socket for this. Instead we check rights in the calls.
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*/
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#define ARPT_CTL_OFFSET 32
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#define ARPT_BASE_CTL (XT_BASE_CTL+ARPT_CTL_OFFSET)
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#define ARPT_SO_SET_REPLACE (XT_SO_SET_REPLACE+ARPT_CTL_OFFSET)
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#define ARPT_SO_SET_ADD_COUNTERS (XT_SO_SET_ADD_COUNTERS+ARPT_CTL_OFFSET)
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#define ARPT_SO_SET_MAX (XT_SO_SET_MAX+ARPT_CTL_OFFSET)
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#define ARPT_SO_GET_INFO (XT_SO_GET_INFO+ARPT_CTL_OFFSET)
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#define ARPT_SO_GET_ENTRIES (XT_SO_GET_ENTRIES+ARPT_CTL_OFFSET)
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/* #define ARPT_SO_GET_REVISION_MATCH XT_SO_GET_REVISION_MATCH */
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#define ARPT_SO_GET_REVISION_TARGET (XT_SO_GET_REVISION_TARGET+ARPT_CTL_OFFSET)
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#define ARPT_SO_GET_MAX (XT_SO_GET_REVISION_TARGET+ARPT_CTL_OFFSET)
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/* CONTINUE verdict for targets */
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#define ARPT_CONTINUE XT_CONTINUE
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/* For standard target */
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#define ARPT_RETURN XT_RETURN
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/* The argument to ARPT_SO_GET_INFO */
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struct arpt_getinfo
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{
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/* Which table: caller fills this in. */
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char name[ARPT_TABLE_MAXNAMELEN];
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/* Kernel fills these in. */
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/* Which hook entry points are valid: bitmask */
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unsigned int valid_hooks;
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/* Hook entry points: one per netfilter hook. */
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unsigned int hook_entry[NF_ARP_NUMHOOKS];
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/* Underflow points. */
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unsigned int underflow[NF_ARP_NUMHOOKS];
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/* Number of entries */
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unsigned int num_entries;
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/* Size of entries. */
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unsigned int size;
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};
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/* The argument to ARPT_SO_SET_REPLACE. */
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struct arpt_replace
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{
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/* Which table. */
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char name[ARPT_TABLE_MAXNAMELEN];
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/* Which hook entry points are valid: bitmask. You can't
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change this. */
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unsigned int valid_hooks;
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/* Number of entries */
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unsigned int num_entries;
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/* Total size of new entries */
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unsigned int size;
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/* Hook entry points. */
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unsigned int hook_entry[NF_ARP_NUMHOOKS];
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/* Underflow points. */
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unsigned int underflow[NF_ARP_NUMHOOKS];
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/* Information about old entries: */
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/* Number of counters (must be equal to current number of entries). */
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unsigned int num_counters;
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/* The old entries' counters. */
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struct xt_counters __user *counters;
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/* The entries (hang off end: not really an array). */
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struct arpt_entry entries[0];
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};
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/* The argument to ARPT_SO_ADD_COUNTERS. */
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#define arpt_counters_info xt_counters_info
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/* The argument to ARPT_SO_GET_ENTRIES. */
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struct arpt_get_entries
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{
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/* Which table: user fills this in. */
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char name[ARPT_TABLE_MAXNAMELEN];
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/* User fills this in: total entry size. */
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unsigned int size;
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/* The entries. */
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struct arpt_entry entrytable[0];
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};
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/* Standard return verdict, or do jump. */
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#define ARPT_STANDARD_TARGET XT_STANDARD_TARGET
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/* Error verdict. */
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#define ARPT_ERROR_TARGET XT_ERROR_TARGET
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/* Helper functions */
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static __inline__ struct arpt_entry_target *arpt_get_target(struct arpt_entry *e)
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{
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return (void *)e + e->target_offset;
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}
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/* fn returns 0 to continue iteration */
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#define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
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({ \
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unsigned int __i; \
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int __ret = 0; \
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struct arpt_entry *__entry; \
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\
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for (__i = 0; __i < (size); __i += __entry->next_offset) { \
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__entry = (void *)(entries) + __i; \
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\
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__ret = fn(__entry , ## args); \
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if (__ret != 0) \
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break; \
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} \
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__ret; \
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})
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/*
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* Main firewall chains definitions and global var's definitions.
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*/
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#ifdef __KERNEL__
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#define arpt_register_target(tgt) \
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({ (tgt)->family = NF_ARP; \
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xt_register_target(tgt); })
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#define arpt_unregister_target(tgt) xt_unregister_target(tgt)
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extern int arpt_register_table(struct arpt_table *table,
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const struct arpt_replace *repl);
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extern void arpt_unregister_table(struct arpt_table *table);
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extern unsigned int arpt_do_table(struct sk_buff **pskb,
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unsigned int hook,
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const struct net_device *in,
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const struct net_device *out,
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struct arpt_table *table);
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#define ARPT_ALIGN(s) (((s) + (__alignof__(struct arpt_entry)-1)) & ~(__alignof__(struct arpt_entry)-1))
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#endif /*__KERNEL__*/
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#endif /* _ARPTABLES_H */
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