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 #include <linux/list.h>
  17 #include <linux/netfilter/nf_conntrack_pptp.h>
  18 #include <net/netfilter/nf_conntrack_extend.h>
  19
  20 /* per conntrack: nat application helper private data */
  21 union nf_conntrack_nat_help {
  22         /* insert nat helper private data here */
  23 #if defined(CONFIG_NF_NAT_PPTP) || defined(CONFIG_NF_NAT_PPTP_MODULE)
  24         struct nf_nat_pptp nat_pptp_info;
  25 #endif
  26 };
  27
  28 struct nf_conn;
  29
  30 /* The structure embedded in the conntrack structure. */
  31 struct nf_conn_nat {
  32         struct hlist_node bysource;
  33         struct nf_conn *ct;
  34         union nf_conntrack_nat_help help;
  35 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
  36     defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE) || \
  37     defined(CONFIG_IP6_NF_TARGET_MASQUERADE) || \
  38     defined(CONFIG_IP6_NF_TARGET_MASQUERADE_MODULE)
  39         int masq_index;
  40 #endif
  41 };
  42
  43 /* Set up the info structure to map into this range. */
  44 extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
  45                                       const struct nf_nat_range *range,
  46                                       enum nf_nat_manip_type maniptype);
  47
  48 /* Is this tuple already taken? (not by us)*/
  49 extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
  50                              const struct nf_conn *ignored_conntrack);
  51
  52 static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
  53 {
  54 #if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
  55         return nf_ct_ext_find(ct, NF_CT_EXT_NAT);
  56 #else
  57         return NULL;
  58 #endif
  59 }
  60
  61 static inline bool nf_nat_oif_changed(unsigned int hooknum,
  62                                       enum ip_conntrack_info ctinfo,
  63                                       struct nf_conn_nat *nat,
  64                                       const struct net_device *out)
  65 {
  66 #if IS_ENABLED(CONFIG_IP_NF_TARGET_MASQUERADE) || \
  67     IS_ENABLED(CONFIG_IP6_NF_TARGET_MASQUERADE)
  68         return nat->masq_index && hooknum == NF_INET_POST_ROUTING &&
  69                CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL &&
  70                nat->masq_index != out->ifindex;
  71 #else
  72         return false;
  73 #endif
  74 }
  75
  76 #endif