alistair23-linux/include/linux/netfilter_ipv4/ip_nat.h
Eric Leblond 41f4689a7c [NETFILTER]: NAT: optional source port randomization support
This patch adds support to NAT to randomize source ports.

Signed-off-by: Eric Leblond <eric@inl.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 12:39:17 -08:00

80 lines
2 KiB
C

#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
#define IP_NAT_RANGE_PROTO_RANDOM 4 /* add randomness to "port" selection */
/* 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 */
int16_t offset_before, offset_after;
};
/* Single range specification. */
struct ip_nat_range
{
/* Set to OR of flags above. */
unsigned int flags;
/* Inclusive: network order. */
__be32 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];
};
#ifdef __KERNEL__
#include <linux/list.h>
/* Protects NAT hash tables, and NAT-private part of conntracks. */
extern rwlock_t ip_nat_lock;
/* The structure embedded in the conntrack structure. */
struct ip_nat_info
{
struct list_head bysource;
struct ip_nat_seq seq[IP_CT_DIR_MAX];
};
struct ip_conntrack;
/* 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);
#else /* !__KERNEL__: iptables wants this to compile. */
#define ip_nat_multi_range ip_nat_multi_range_compat
#endif /*__KERNEL__*/
#endif