![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
491 lines
12 KiB
C
491 lines
12 KiB
C
/*
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* 25-Jul-1998 Major changes to allow for ip chain table
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*
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* 3-Jan-2000 Named tables to allow packet selection for different uses.
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*/
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/*
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* Format of an IP firewall descriptor
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*
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* src, dst, src_mask, dst_mask are always stored in network byte order.
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* flags are stored in host byte order (of course).
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* Port numbers are stored in HOST byte order.
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*/
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#ifndef _IPTABLES_H
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#define _IPTABLES_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/ip.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_ipv4.h>
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#define IPT_FUNCTION_MAXNAMELEN 30
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#define IPT_TABLE_MAXNAMELEN 32
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/* Yes, Virginia, you have to zero the padding. */
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struct ipt_ip {
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/* Source and destination IP addr */
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struct in_addr src, dst;
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/* Mask for src and dest IP addr */
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struct in_addr smsk, dmsk;
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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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/* Protocol, 0 = ANY */
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u_int16_t proto;
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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_int8_t invflags;
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};
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struct ipt_entry_match
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{
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union {
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struct {
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u_int16_t match_size;
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/* Used by userspace */
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char name[IPT_FUNCTION_MAXNAMELEN-1];
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u_int8_t revision;
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} user;
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struct {
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u_int16_t match_size;
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/* Used inside the kernel */
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struct ipt_match *match;
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} kernel;
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/* Total length */
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u_int16_t match_size;
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} u;
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unsigned char data[0];
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};
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struct ipt_entry_target
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{
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union {
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struct {
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u_int16_t target_size;
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/* Used by userspace */
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char name[IPT_FUNCTION_MAXNAMELEN-1];
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u_int8_t revision;
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} user;
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struct {
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u_int16_t target_size;
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/* Used inside the kernel */
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struct ipt_target *target;
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} kernel;
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/* Total length */
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u_int16_t target_size;
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} u;
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unsigned char data[0];
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};
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struct ipt_standard_target
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{
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struct ipt_entry_target target;
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int verdict;
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};
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struct ipt_counters
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{
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u_int64_t pcnt, bcnt; /* Packet and byte counters */
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};
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/* Values for "flag" field in struct ipt_ip (general ip structure). */
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#define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
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#define IPT_F_MASK 0x01 /* All possible flag bits mask. */
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/* Values for "inv" field in struct ipt_ip. */
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#define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
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#define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */
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#define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */
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#define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */
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#define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */
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#define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */
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#define IPT_INV_PROTO 0x40 /* Invert the sense of PROTO. */
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#define IPT_INV_MASK 0x7F /* 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 IP header stuff 2) match specific
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stuff 3) the target to perform if the rule matches */
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struct ipt_entry
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{
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struct ipt_ip ip;
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/* Mark with fields that we care about. */
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unsigned int nfcache;
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/* Size of ipt_entry + matches */
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u_int16_t target_offset;
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/* Size of ipt_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 ipt_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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#define IPT_BASE_CTL 64 /* base for firewall socket options */
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#define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
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#define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
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#define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS
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#define IPT_SO_GET_INFO (IPT_BASE_CTL)
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#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
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#define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2)
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#define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3)
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#define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET
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/* CONTINUE verdict for targets */
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#define IPT_CONTINUE 0xFFFFFFFF
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/* For standard target */
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#define IPT_RETURN (-NF_REPEAT - 1)
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/* TCP matching stuff */
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struct ipt_tcp
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{
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u_int16_t spts[2]; /* Source port range. */
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u_int16_t dpts[2]; /* Destination port range. */
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u_int8_t option; /* TCP Option iff non-zero*/
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u_int8_t flg_mask; /* TCP flags mask byte */
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u_int8_t flg_cmp; /* TCP flags compare byte */
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u_int8_t invflags; /* Inverse flags */
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};
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/* Values for "inv" field in struct ipt_tcp. */
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#define IPT_TCP_INV_SRCPT 0x01 /* Invert the sense of source ports. */
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#define IPT_TCP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */
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#define IPT_TCP_INV_FLAGS 0x04 /* Invert the sense of TCP flags. */
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#define IPT_TCP_INV_OPTION 0x08 /* Invert the sense of option test. */
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#define IPT_TCP_INV_MASK 0x0F /* All possible flags. */
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/* UDP matching stuff */
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struct ipt_udp
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{
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u_int16_t spts[2]; /* Source port range. */
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u_int16_t dpts[2]; /* Destination port range. */
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u_int8_t invflags; /* Inverse flags */
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};
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/* Values for "invflags" field in struct ipt_udp. */
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#define IPT_UDP_INV_SRCPT 0x01 /* Invert the sense of source ports. */
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#define IPT_UDP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */
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#define IPT_UDP_INV_MASK 0x03 /* All possible flags. */
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/* ICMP matching stuff */
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struct ipt_icmp
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{
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u_int8_t type; /* type to match */
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u_int8_t code[2]; /* range of code */
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u_int8_t invflags; /* Inverse flags */
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};
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/* Values for "inv" field for struct ipt_icmp. */
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#define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */
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/* The argument to IPT_SO_GET_INFO */
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struct ipt_getinfo
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{
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/* Which table: caller fills this in. */
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char name[IPT_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_IP_NUMHOOKS];
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/* Underflow points. */
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unsigned int underflow[NF_IP_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 IPT_SO_SET_REPLACE. */
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struct ipt_replace
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{
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/* Which table. */
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char name[IPT_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_IP_NUMHOOKS];
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/* Underflow points. */
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unsigned int underflow[NF_IP_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 ipt_counters __user *counters;
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/* The entries (hang off end: not really an array). */
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struct ipt_entry entries[0];
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};
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/* The argument to IPT_SO_ADD_COUNTERS. */
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struct ipt_counters_info
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{
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/* Which table. */
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char name[IPT_TABLE_MAXNAMELEN];
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unsigned int num_counters;
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/* The counters (actually `number' of these). */
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struct ipt_counters counters[0];
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};
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/* The argument to IPT_SO_GET_ENTRIES. */
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struct ipt_get_entries
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{
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/* Which table: user fills this in. */
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char name[IPT_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 ipt_entry entrytable[0];
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};
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/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
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* kernel supports, if >= revision. */
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struct ipt_get_revision
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{
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char name[IPT_FUNCTION_MAXNAMELEN-1];
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u_int8_t revision;
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};
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/* Standard return verdict, or do jump. */
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#define IPT_STANDARD_TARGET ""
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/* Error verdict. */
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#define IPT_ERROR_TARGET "ERROR"
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/* Helper functions */
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static __inline__ struct ipt_entry_target *
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ipt_get_target(struct ipt_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 IPT_MATCH_ITERATE(e, 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 ipt_entry_match *__match; \
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\
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for (__i = sizeof(struct ipt_entry); \
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__i < (e)->target_offset; \
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__i += __match->u.match_size) { \
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__match = (void *)(e) + __i; \
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\
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__ret = fn(__match , ## 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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/* fn returns 0 to continue iteration */
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#define IPT_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 ipt_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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#include <linux/init.h>
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extern void ipt_init(void) __init;
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struct ipt_match
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{
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struct list_head list;
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const char name[IPT_FUNCTION_MAXNAMELEN-1];
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u_int8_t revision;
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/* Return true or false: return FALSE and set *hotdrop = 1 to
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force immediate packet drop. */
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/* Arguments changed since 2.4, as this must now handle
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non-linear skbs, using skb_copy_bits and
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skb_ip_make_writable. */
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int (*match)(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop);
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/* Called when user tries to insert an entry of this type. */
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/* Should return true or false. */
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int (*checkentry)(const char *tablename,
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const struct ipt_ip *ip,
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void *matchinfo,
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unsigned int matchinfosize,
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unsigned int hook_mask);
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/* Called when entry of this type deleted. */
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void (*destroy)(void *matchinfo, unsigned int matchinfosize);
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/* Set this to THIS_MODULE. */
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struct module *me;
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};
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/* Registration hooks for targets. */
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struct ipt_target
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{
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struct list_head list;
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const char name[IPT_FUNCTION_MAXNAMELEN-1];
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u_int8_t revision;
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/* Called when user tries to insert an entry of this type:
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hook_mask is a bitmask of hooks from which it can be
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called. */
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/* Should return true or false. */
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int (*checkentry)(const char *tablename,
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const struct ipt_entry *e,
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void *targinfo,
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unsigned int targinfosize,
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unsigned int hook_mask);
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/* Called when entry of this type deleted. */
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void (*destroy)(void *targinfo, unsigned int targinfosize);
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/* Returns verdict. Argument order changed since 2.4, as this
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must now handle non-linear skbs, using skb_copy_bits and
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skb_ip_make_writable. */
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unsigned int (*target)(struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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unsigned int hooknum,
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const void *targinfo,
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void *userdata);
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/* Set this to THIS_MODULE. */
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struct module *me;
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};
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extern int ipt_register_target(struct ipt_target *target);
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extern void ipt_unregister_target(struct ipt_target *target);
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extern int ipt_register_match(struct ipt_match *match);
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extern void ipt_unregister_match(struct ipt_match *match);
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/* Furniture shopping... */
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struct ipt_table
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{
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struct list_head list;
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/* A unique name... */
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char name[IPT_TABLE_MAXNAMELEN];
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/* What hooks you will enter on */
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unsigned int valid_hooks;
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/* Lock for the curtain */
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rwlock_t lock;
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/* Man behind the curtain... */
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struct ipt_table_info *private;
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/* Set to THIS_MODULE. */
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struct module *me;
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};
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/* net/sched/ipt.c: Gimme access to your targets! Gets target->me. */
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extern struct ipt_target *ipt_find_target(const char *name, u8 revision);
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/* Standard entry. */
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struct ipt_standard
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{
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struct ipt_entry entry;
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struct ipt_standard_target target;
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};
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struct ipt_error_target
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{
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struct ipt_entry_target target;
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char errorname[IPT_FUNCTION_MAXNAMELEN];
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};
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struct ipt_error
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{
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struct ipt_entry entry;
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struct ipt_error_target target;
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};
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extern int ipt_register_table(struct ipt_table *table,
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const struct ipt_replace *repl);
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extern void ipt_unregister_table(struct ipt_table *table);
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extern unsigned int ipt_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 ipt_table *table,
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void *userdata);
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#define IPT_ALIGN(s) (((s) + (__alignof__(struct ipt_entry)-1)) & ~(__alignof__(struct ipt_entry)-1))
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#endif /*__KERNEL__*/
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#endif /* _IPTABLES_H */
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