1#ifndef _NF_NAT_H
2#define _NF_NAT_H
3#include <linux/netfilter_ipv4.h>
4#include <net/netfilter/nf_conntrack_tuple.h>
5
6#define NF_NAT_MAPPING_TYPE_MAX_NAMELEN 16
7
8enum nf_nat_manip_type
9{
10	IP_NAT_MANIP_SRC,
11	IP_NAT_MANIP_DST
12};
13
14/* SRC manip occurs POST_ROUTING or LOCAL_IN */
15#define HOOK2MANIP(hooknum) ((hooknum) != NF_IP_POST_ROUTING && (hooknum) != NF_IP_LOCAL_IN)
16
17#define IP_NAT_RANGE_MAP_IPS 1
18#define IP_NAT_RANGE_PROTO_SPECIFIED 2
19#define IP_NAT_RANGE_PROTO_RANDOM 4
20
21/* NAT sequence number modifications */
22struct nf_nat_seq {
23	/* position of the last TCP sequence number modification (if any) */
24	u_int32_t correction_pos;
25
26	/* sequence number offset before and after last modification */
27	int16_t offset_before, offset_after;
28};
29
30/* Single range specification. */
31struct nf_nat_range
32{
33	/* Set to OR of flags above. */
34	unsigned int flags;
35
36	/* Inclusive: network order. */
37	__be32 min_ip, max_ip;
38
39	/* Inclusive: network order */
40	union nf_conntrack_man_proto min, max;
41};
42
43/* For backwards compat: don't use in modern code. */
44struct nf_nat_multi_range_compat
45{
46	unsigned int rangesize; /* Must be 1. */
47
48	/* hangs off end. */
49	struct nf_nat_range range[1];
50};
51
52#ifdef __KERNEL__
53#include <linux/list.h>
54
55/* The structure embedded in the conntrack structure. */
56struct nf_nat_info
57{
58	struct list_head bysource;
59
60	/* cone NAT or Symmetric NAT */
61	struct list_head bycone;
62	u_int32_t nat_type;
63
64	struct nf_nat_seq seq[IP_CT_DIR_MAX];
65};
66
67struct nf_conn;
68
69/* Set up the info structure to map into this range. */
70extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
71				      const struct nf_nat_range *range,
72				      unsigned int hooknum);
73
74/* Is this tuple already taken? (not by us)*/
75extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
76			     const struct nf_conn *ignored_conntrack);
77
78extern int nf_nat_module_is_loaded;
79
80#else  /* !__KERNEL__: iptables wants this to compile. */
81#define nf_nat_multi_range nf_nat_multi_range_compat
82#endif /*__KERNEL__*/
83#endif
84