include/net/netfilter/nf_nat_helper.h

   1 #ifndef _NF_NAT_HELPER_H
   2 #define _NF_NAT_HELPER_H
   3 /* NAT protocol helper routines. */
   4
   5 #include <net/netfilter/nf_conntrack.h>
   6
   7 struct sk_buff;
   8
   9 /* These return true or false. */
  10 extern int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
  11                                       struct nf_conn *ct,
  12                                       enum ip_conntrack_info ctinfo,
  13                                       unsigned int match_offset,
  14                                       unsigned int match_len,
  15                                       const char *rep_buffer,
  16                                       unsigned int rep_len, bool adjust);
  17
  18 static inline int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
  19                                            struct nf_conn *ct,
  20                                            enum ip_conntrack_info ctinfo,
  21                                            unsigned int match_offset,
  22                                            unsigned int match_len,
  23                                            const char *rep_buffer,
  24                                            unsigned int rep_len)
  25 {
  26         return __nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
  27                                           match_offset, match_len,
  28                                           rep_buffer, rep_len, true);
  29 }
  30
  31 extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
  32                                     struct nf_conn *ct,
  33                                     enum ip_conntrack_info ctinfo,
  34                                     unsigned int match_offset,
  35                                     unsigned int match_len,
  36                                     const char *rep_buffer,
  37                                     unsigned int rep_len);
  38
  39 extern void nf_nat_set_seq_adjust(struct nf_conn *ct,
  40                                   enum ip_conntrack_info ctinfo,
  41                                   __be32 seq, s16 off);
  42 extern int nf_nat_seq_adjust(struct sk_buff *skb,
  43                              struct nf_conn *ct,
  44                              enum ip_conntrack_info ctinfo);
  45 extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
  46                                      struct nf_conn *ct,
  47                                      enum ip_conntrack_info ctinfo);
  48
  49 /* Setup NAT on this expected conntrack so it follows master, but goes
  50  * to port ct->master->saved_proto. */
  51 extern void nf_nat_follow_master(struct nf_conn *ct,
  52                                  struct nf_conntrack_expect *this);
  53
  54 extern s16 nf_nat_get_offset(const struct nf_conn *ct,
  55                              enum ip_conntrack_dir dir,
  56                              u32 seq);
  57 #endif