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#ifndef _IP_NAT_H
#define _IP_NAT_H
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
#define IP_NAT_MAPPING_TYPE_MAX_NAMELEN 16
enum ip_nat_manip_type
{
IP_NAT_MANIP_SRC,
IP_NAT_MANIP_DST
};
/* SRC manip occurs POST_ROUTING or LOCAL_IN */
#define HOOK2MANIP(hooknum) ((hooknum) != NF_IP_POST_ROUTING && (hooknum) != NF_IP_LOCAL_IN)
#define IP_NAT_RANGE_MAP_IPS 1
#define IP_NAT_RANGE_PROTO_SPECIFIED 2
/* NAT sequence number modifications */
struct ip_nat_seq {
/* position of the last TCP sequence number
* modification (if any) */
u_int32_t correction_pos;
/* sequence number offset before and after last modification */
int32_t offset_before, offset_after;
};
/* Single range specification. */
struct ip_nat_range
{
/* Set to OR of flags above. */
unsigned int flags;
/* Inclusive: network order. */
u_int32_t min_ip, max_ip;
/* Inclusive: network order */
union ip_conntrack_manip_proto min, max;
};
/* For backwards compat: don't use in modern code. */
struct ip_nat_multi_range_compat
{
unsigned int rangesize; /* Must be 1. */
/* hangs off end. */
struct ip_nat_range range[1];
};
/* Worst case: local-out manip + 1 post-routing, and reverse dirn. */
#define IP_NAT_MAX_MANIPS (2*2)
struct ip_nat_info_manip
{
/* The direction. */
u_int8_t direction;
/* Which hook the manipulation happens on. */
u_int8_t hooknum;
/* The manipulation type. */
u_int8_t maniptype;
/* Manipulations to occur at each conntrack in this dirn. */
struct ip_conntrack_manip manip;
};
#ifdef __KERNEL__
#include <linux/list.h>
#include <linux/netfilter_ipv4/lockhelp.h>
/* Protects NAT hash tables, and NAT-private part of conntracks. */
DECLARE_RWLOCK_EXTERN(ip_nat_lock);
/* The structure embedded in the conntrack structure. */
struct ip_nat_info
{
/* Set to zero when conntrack created: bitmask of maniptypes */
u_int16_t initialized;
u_int16_t num_manips;
/* Manipulations to be done on this conntrack. */
struct ip_nat_info_manip manips[IP_NAT_MAX_MANIPS];
struct list_head bysource;
/* Helper (NULL if none). */
struct ip_nat_helper *helper;
struct ip_nat_seq seq[IP_CT_DIR_MAX];
};
/* Set up the info structure to map into this range. */
extern unsigned int ip_nat_setup_info(struct ip_conntrack *conntrack,
const struct ip_nat_range *range,
unsigned int hooknum);
/* Is this tuple already taken? (not by us)*/
extern int ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple,
const struct ip_conntrack *ignored_conntrack);
/* Calculate relative checksum. */
extern u_int16_t ip_nat_cheat_check(u_int32_t oldvalinv,
u_int32_t newval,
u_int16_t oldcheck);
#else /* !__KERNEL__: iptables wants this to compile. */
#define ip_nat_multi_range ip_nat_multi_range_compat
#endif /*__KERNEL__*/
#endif
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