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
13 enum 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 */
23 union 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. */
31 struct 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. */
39 unsigned int nf_nat_setup_info(struct nf_conn *ct,
40 const struct nf_nat_range2 *range,
41 enum nf_nat_manip_type maniptype);
42
43 extern unsigned int nf_nat_alloc_null_binding(struct nf_conn *ct,
44 unsigned int hooknum);
45
46 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct);
47
nfct_nat(const struct nf_conn * ct)48 static 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
nf_nat_oif_changed(unsigned int hooknum,enum ip_conntrack_info ctinfo,struct nf_conn_nat * nat,const struct net_device * out)57 static 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
71 int 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);
73 void nf_nat_unregister_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops,
74 unsigned int ops_count);
75
76 unsigned int nf_nat_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
77 unsigned int hooknum, struct sk_buff *skb);
78
79 unsigned 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);
82 void nf_nat_csum_recalc(struct sk_buff *skb,
83 u8 nfproto, u8 proto, void *data, __sum16 *check,
84 int datalen, int oldlen);
85
86 int nf_nat_icmp_reply_translation(struct sk_buff *skb, struct nf_conn *ct,
87 enum ip_conntrack_info ctinfo,
88 unsigned int hooknum);
89
90 int 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
94 int nf_nat_ipv4_register_fn(struct net *net, const struct nf_hook_ops *ops);
95 void nf_nat_ipv4_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
96
97 int nf_nat_ipv6_register_fn(struct net *net, const struct nf_hook_ops *ops);
98 void nf_nat_ipv6_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
99
100 int nf_nat_inet_register_fn(struct net *net, const struct nf_hook_ops *ops);
101 void nf_nat_inet_unregister_fn(struct net *net, const struct nf_hook_ops *ops);
102
103 unsigned int
104 nf_nat_inet_fn(void *priv, struct sk_buff *skb,
105 const struct nf_hook_state *state);
106
107 int nf_ct_nat(struct sk_buff *skb, struct nf_conn *ct,
108 enum ip_conntrack_info ctinfo, int *action,
109 const struct nf_nat_range2 *range, bool commit);
110
nf_nat_initialized(const struct nf_conn * ct,enum nf_nat_manip_type manip)111 static inline int nf_nat_initialized(const struct nf_conn *ct,
112 enum nf_nat_manip_type manip)
113 {
114 if (manip == NF_NAT_MANIP_SRC)
115 return ct->status & IPS_SRC_NAT_DONE;
116 else
117 return ct->status & IPS_DST_NAT_DONE;
118 }
119 #endif
120