LXR linux/include/net/netfilter/nf

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _NF_NAT_H
   3#define _NF_NAT_H
   4
   5#include <linux/list.h>
   6#include <linux/netfilter_ipv4.h>
   7#include <linux/netfilter/nf_conntrack_pptp.h>
   8#include <net/netfilter/nf_conntrack.h>
   9#include <net/netfilter/nf_conntrack_extend.h>
  10#include <net/netfilter/nf_conntrack_tuple.h>
  11#include <uapi/linux/netfilter/nf_nat.h>
  12
  13enum nf_nat_manip_type {
  14        NF_NAT_MANIP_SRC,
  15        NF_NAT_MANIP_DST
  16};
  17
  18/* SRC manip occurs POST_ROUTING or LOCAL_IN */
  19#define HOOK2MANIP(hooknum) ((hooknum) != NF_INET_POST_ROUTING && \
  20                             (hooknum) != NF_INET_LOCAL_IN)
  21
  22/* per conntrack: nat application helper private data */
  23union nf_conntrack_nat_help {
  24        /* insert nat helper private data here */
  25#if IS_ENABLED(CONFIG_NF_NAT_PPTP)
  26        struct nf_nat_pptp nat_pptp_info;
  27#endif
  28};
  29
  30/* The structure embedded in the conntrack structure. */
  31struct nf_conn_nat {
  32        union nf_conntrack_nat_help help;
  33#if IS_ENABLED(CONFIG_NF_NAT_MASQUERADE)
  34        int masq_index;
  35#endif
  36};
  37
  38/* Set up the info structure to map into this range. */
  39unsigned int nf_nat_setup_info(struct nf_conn *ct,
  40                               const struct nf_nat_range2 *range,
  41                               enum nf_nat_manip_type maniptype);
  42
  43extern unsigned int nf_nat_alloc_null_binding(struct nf_conn *ct,
  44                                              unsigned int hooknum);
  45
  46struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct);
  47
  48static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
  49{
  50#if IS_ENABLED(CONFIG_NF_NAT)
  51        return nf_ct_ext_find(ct, NF_CT_EXT_NAT);
  52#else
  53        return NULL;
  54#endif
  55}
  56
  57static inline bool nf_nat_oif_changed(unsigned int hooknum,
  58                                      enum ip_conntrack_info ctinfo,
  59                                      struct nf_conn_nat *nat,
  60                                      const struct net_device *out)
  61{
  62#if IS_ENABLED(CONFIG_NF_NAT_MASQUERADE)
  63        return nat && nat->masq_index && hooknum == NF_INET_POST_ROUTING &&
  64               CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL &&
  65               nat->masq_index != out->ifindex;
  66#else
  67        return false;
  68#endif
  69}
  70
  71int nf_nat_register_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops,
  72                       const struct nf_hook_ops *nat_ops, unsigned int ops_count);
  73void nf_nat_unregister_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops,
  74                          unsigned int ops_count);
  75
  76unsigned int nf_nat_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
  77                           unsigned int hooknum, struct sk_buff *skb);
  78
  79unsigned int nf_nat_manip_pkt(struct sk_buff *skb, struct nf_conn *ct,
  80                              enum nf_nat_manip_type mtype,
  81                              enum ip_conntrack_dir dir);
  82void nf_nat_csum_recalc(struct sk_buff *skb,
  83                        u8 nfproto, u8 proto, void *data, __sum16 *check,
  84                        int datalen, int oldlen);
  85
  86int nf_nat_icmp_reply_translation(struct sk_buff *skb, struct nf_conn *ct,
  87                                  enum ip_conntrack_info ctinfo,
  88                                  unsigned int hooknum);
  89
  90int nf_nat_icmpv6_reply_translation(struct sk_buff *skb, struct nf_conn *ct,
  91                                    enum ip_conntrack_info ctinfo,
  92                                    unsigned int hooknum, unsigned int hdrlen);
  93
  94int nf_nat_ipv4_register_fn(struct net *net, const struct nf_hook_ops *ops);
  95void nf_nat_ipv4_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
  96
  97int nf_nat_ipv6_register_fn(struct net *net, const struct nf_hook_ops *ops);
  98void nf_nat_ipv6_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
  99
 100int nf_nat_inet_register_fn(struct net *net, const struct nf_hook_ops *ops);
 101void nf_nat_inet_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
 102
 103unsigned int
 104nf_nat_inet_fn(void *priv, struct sk_buff *skb,
 105               const struct nf_hook_state *state);
 106
 107int nf_xfrm_me_harder(struct net *n, struct sk_buff *s, unsigned int family);
 108
 109static inline int nf_nat_initialized(struct nf_conn *ct,
 110                                     enum nf_nat_manip_type manip)
 111{
 112        if (manip == NF_NAT_MANIP_SRC)
 113                return ct->status & IPS_SRC_NAT_DONE;
 114        else
 115                return ct->status & IPS_DST_NAT_DONE;
 116}
 117#endif
 118