include/net/netfilter/nf_nat.h

   1 #ifndef _NF_NAT_H
   2 #define _NF_NAT_H
   3 #include <linux/netfilter_ipv4.h>
   4 #include <linux/netfilter/nf_nat.h>
   5 #include <net/netfilter/nf_conntrack_tuple.h>
   6
   7 enum nf_nat_manip_type {
   8         NF_NAT_MANIP_SRC,
   9         NF_NAT_MANIP_DST
  10 };
  11
  12 /* SRC manip occurs POST_ROUTING or LOCAL_IN */
  13 #define HOOK2MANIP(hooknum) ((hooknum) != NF_INET_POST_ROUTING && \
  14                              (hooknum) != NF_INET_LOCAL_IN)
  15
  16 /* NAT sequence number modifications */
  17 struct nf_nat_seq {
  18         /* position of the last TCP sequence number modification (if any) */
  19         u_int32_t correction_pos;
  20
  21         /* sequence number offset before and after last modification */
  22         int16_t offset_before, offset_after;
  23 };
  24
  25 #include <linux/list.h>
  26 #include <linux/netfilter/nf_conntrack_pptp.h>
  27 #include <net/netfilter/nf_conntrack_extend.h>
  28
  29 /* per conntrack: nat application helper private data */
  30 union nf_conntrack_nat_help {
  31         /* insert nat helper private data here */
  32 #if defined(CONFIG_NF_NAT_PPTP) || defined(CONFIG_NF_NAT_PPTP_MODULE)
  33         struct nf_nat_pptp nat_pptp_info;
  34 #endif
  35 };
  36
  37 struct nf_conn;
  38
  39 /* The structure embedded in the conntrack structure. */
  40 struct nf_conn_nat {
  41         struct hlist_node bysource;
  42         struct nf_nat_seq seq[IP_CT_DIR_MAX];
  43         struct nf_conn *ct;
  44         union nf_conntrack_nat_help help;
  45 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
  46     defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
  47         int masq_index;
  48 #endif
  49 };
  50
  51 /* Set up the info structure to map into this range. */
  52 extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
  53                                       const struct nf_nat_ipv4_range *range,
  54                                       enum nf_nat_manip_type maniptype);
  55
  56 /* Is this tuple already taken? (not by us)*/
  57 extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
  58                              const struct nf_conn *ignored_conntrack);
  59
  60 static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
  61 {
  62 #if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
  63         return nf_ct_ext_find(ct, NF_CT_EXT_NAT);
  64 #else
  65         return NULL;
  66 #endif
  67 }
  68
  69 #endif