root/include/net/netfilter/nf_nat_helper.h

DEFINITIONS

1. nf_nat_mangle_tcp_packet

#ifndef _NF_NAT_HELPER_H
#define _NF_NAT_HELPER_H
/* NAT protocol helper routines. */

#include <net/netfilter/nf_conntrack.h>

struct sk_buff;

/* These return true or false. */
int __nf_nat_mangle_tcp_packet(struct sk_buff *skb, struct nf_conn *ct,
                               enum ip_conntrack_info ctinfo,
                               unsigned int protoff, unsigned int match_offset,
                               unsigned int match_len, const char *rep_buffer,
                               unsigned int rep_len, bool adjust);

static inline int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
                                           struct nf_conn *ct,
                                           enum ip_conntrack_info ctinfo,
                                           unsigned int protoff,
                                           unsigned int match_offset,
                                           unsigned int match_len,
                                           const char *rep_buffer,
                                           unsigned int rep_len)
{
        return __nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
                                          match_offset, match_len,
                                          rep_buffer, rep_len, true);
}

int nf_nat_mangle_udp_packet(struct sk_buff *skb, struct nf_conn *ct,
                             enum ip_conntrack_info ctinfo,
                             unsigned int protoff, unsigned int match_offset,
                             unsigned int match_len, const char *rep_buffer,
                             unsigned int rep_len);

/* Setup NAT on this expected conntrack so it follows master, but goes
 * to port ct->master->saved_proto. */
void nf_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this);

#endif