- 根目录:
- include
- net
- netfilter
- nf_nat.h
#ifndef _NF_NAT_H
#define _NF_NAT_H
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/nf_nat.h>
#include <net/netfilter/nf_conntrack_tuple.h>
enum nf_nat_manip_type {
NF_NAT_MANIP_SRC,
NF_NAT_MANIP_DST
};
/* SRC manip occurs POST_ROUTING or LOCAL_IN */
#define HOOK2MANIP(hooknum) ((hooknum) != NF_INET_POST_ROUTING && \
(hooknum) != NF_INET_LOCAL_IN)
/* NAT sequence number modifications */
struct nf_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;
};
#include <linux/list.h>
#include <linux/netfilter/nf_conntrack_pptp.h>
#include <net/netfilter/nf_conntrack_extend.h>
/* per conntrack: nat application helper private data */
union nf_conntrack_nat_help {
/* insert nat helper private data here */
#if defined(CONFIG_NF_NAT_PPTP) || defined(CONFIG_NF_NAT_PPTP_MODULE)
struct nf_nat_pptp nat_pptp_info;
#endif
};
struct nf_conn;
/* The structure embedded in the conntrack structure. */
struct nf_conn_nat {
struct hlist_node bysource;
struct nf_nat_seq seq[IP_CT_DIR_MAX];
struct nf_conn *ct;
union nf_conntrack_nat_help help;
#if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE) || \
defined(CONFIG_IP6_NF_TARGET_MASQUERADE) || \
defined(CONFIG_IP6_NF_TARGET_MASQUERADE_MODULE)
int masq_index;
#endif
};
/* Set up the info structure to map into this range. */
extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
const struct nf_nat_range *range,
enum nf_nat_manip_type maniptype);
/* Is this tuple already taken? (not by us)*/
extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
{
#if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
return nf_ct_ext_find(ct, NF_CT_EXT_NAT);
#else
return NULL;
#endif
}
static inline bool nf_nat_oif_changed(unsigned int hooknum,
enum ip_conntrack_info ctinfo,
struct nf_conn_nat *nat,
const struct net_device *out)
{
#if IS_ENABLED(CONFIG_IP_NF_TARGET_MASQUERADE) || \
IS_ENABLED(CONFIG_IP6_NF_TARGET_MASQUERADE)
return nat->masq_index && hooknum == NF_INET_POST_ROUTING &&
CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL &&
nat->masq_index != out->ifindex;
#else
return false;
#endif
}
#endif