1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/module.h>
4 #include <linux/netfilter/nf_tables.h>
5 #include <net/netfilter/nf_nat.h>
6 #include <net/netfilter/nf_tables.h>
7 #include <net/netfilter/nf_tables_ipv4.h>
8 #include <net/netfilter/nf_tables_ipv6.h>
9 
nft_nat_do_chain(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)10 static unsigned int nft_nat_do_chain(void *priv, struct sk_buff *skb,
11 				     const struct nf_hook_state *state)
12 {
13 	struct nft_pktinfo pkt;
14 
15 	nft_set_pktinfo(&pkt, skb, state);
16 
17 	switch (state->pf) {
18 #ifdef CONFIG_NF_TABLES_IPV4
19 	case NFPROTO_IPV4:
20 		nft_set_pktinfo_ipv4(&pkt);
21 		break;
22 #endif
23 #ifdef CONFIG_NF_TABLES_IPV6
24 	case NFPROTO_IPV6:
25 		nft_set_pktinfo_ipv6(&pkt);
26 		break;
27 #endif
28 	default:
29 		break;
30 	}
31 
32 	return nft_do_chain(&pkt, priv);
33 }
34 
35 #ifdef CONFIG_NF_TABLES_IPV4
36 static const struct nft_chain_type nft_chain_nat_ipv4 = {
37 	.name		= "nat",
38 	.type		= NFT_CHAIN_T_NAT,
39 	.family		= NFPROTO_IPV4,
40 	.owner		= THIS_MODULE,
41 	.hook_mask	= (1 << NF_INET_PRE_ROUTING) |
42 			  (1 << NF_INET_POST_ROUTING) |
43 			  (1 << NF_INET_LOCAL_OUT) |
44 			  (1 << NF_INET_LOCAL_IN),
45 	.hooks		= {
46 		[NF_INET_PRE_ROUTING]	= nft_nat_do_chain,
47 		[NF_INET_POST_ROUTING]	= nft_nat_do_chain,
48 		[NF_INET_LOCAL_OUT]	= nft_nat_do_chain,
49 		[NF_INET_LOCAL_IN]	= nft_nat_do_chain,
50 	},
51 	.ops_register = nf_nat_ipv4_register_fn,
52 	.ops_unregister = nf_nat_ipv4_unregister_fn,
53 };
54 #endif
55 
56 #ifdef CONFIG_NF_TABLES_IPV6
57 static const struct nft_chain_type nft_chain_nat_ipv6 = {
58 	.name		= "nat",
59 	.type		= NFT_CHAIN_T_NAT,
60 	.family		= NFPROTO_IPV6,
61 	.owner		= THIS_MODULE,
62 	.hook_mask	= (1 << NF_INET_PRE_ROUTING) |
63 			  (1 << NF_INET_POST_ROUTING) |
64 			  (1 << NF_INET_LOCAL_OUT) |
65 			  (1 << NF_INET_LOCAL_IN),
66 	.hooks		= {
67 		[NF_INET_PRE_ROUTING]	= nft_nat_do_chain,
68 		[NF_INET_POST_ROUTING]	= nft_nat_do_chain,
69 		[NF_INET_LOCAL_OUT]	= nft_nat_do_chain,
70 		[NF_INET_LOCAL_IN]	= nft_nat_do_chain,
71 	},
72 	.ops_register		= nf_nat_ipv6_register_fn,
73 	.ops_unregister		= nf_nat_ipv6_unregister_fn,
74 };
75 #endif
76 
77 #ifdef CONFIG_NF_TABLES_INET
nft_nat_inet_reg(struct net * net,const struct nf_hook_ops * ops)78 static int nft_nat_inet_reg(struct net *net, const struct nf_hook_ops *ops)
79 {
80 	return nf_nat_inet_register_fn(net, ops);
81 }
82 
nft_nat_inet_unreg(struct net * net,const struct nf_hook_ops * ops)83 static void nft_nat_inet_unreg(struct net *net, const struct nf_hook_ops *ops)
84 {
85 	nf_nat_inet_unregister_fn(net, ops);
86 }
87 
88 static const struct nft_chain_type nft_chain_nat_inet = {
89 	.name		= "nat",
90 	.type		= NFT_CHAIN_T_NAT,
91 	.family		= NFPROTO_INET,
92 	.owner		= THIS_MODULE,
93 	.hook_mask	= (1 << NF_INET_PRE_ROUTING) |
94 			  (1 << NF_INET_LOCAL_IN) |
95 			  (1 << NF_INET_LOCAL_OUT) |
96 			  (1 << NF_INET_POST_ROUTING),
97 	.hooks		= {
98 		[NF_INET_PRE_ROUTING]	= nft_nat_do_chain,
99 		[NF_INET_LOCAL_IN]	= nft_nat_do_chain,
100 		[NF_INET_LOCAL_OUT]	= nft_nat_do_chain,
101 		[NF_INET_POST_ROUTING]	= nft_nat_do_chain,
102 	},
103 	.ops_register		= nft_nat_inet_reg,
104 	.ops_unregister		= nft_nat_inet_unreg,
105 };
106 #endif
107 
nft_chain_nat_init(void)108 static int __init nft_chain_nat_init(void)
109 {
110 #ifdef CONFIG_NF_TABLES_IPV6
111 	nft_register_chain_type(&nft_chain_nat_ipv6);
112 #endif
113 #ifdef CONFIG_NF_TABLES_IPV4
114 	nft_register_chain_type(&nft_chain_nat_ipv4);
115 #endif
116 #ifdef CONFIG_NF_TABLES_INET
117 	nft_register_chain_type(&nft_chain_nat_inet);
118 #endif
119 
120 	return 0;
121 }
122 
nft_chain_nat_exit(void)123 static void __exit nft_chain_nat_exit(void)
124 {
125 #ifdef CONFIG_NF_TABLES_IPV4
126 	nft_unregister_chain_type(&nft_chain_nat_ipv4);
127 #endif
128 #ifdef CONFIG_NF_TABLES_IPV6
129 	nft_unregister_chain_type(&nft_chain_nat_ipv6);
130 #endif
131 #ifdef CONFIG_NF_TABLES_INET
132 	nft_unregister_chain_type(&nft_chain_nat_inet);
133 #endif
134 }
135 
136 module_init(nft_chain_nat_init);
137 module_exit(nft_chain_nat_exit);
138 
139 MODULE_LICENSE("GPL");
140 #ifdef CONFIG_NF_TABLES_IPV4
141 MODULE_ALIAS_NFT_CHAIN(AF_INET, "nat");
142 #endif
143 #ifdef CONFIG_NF_TABLES_IPV6
144 MODULE_ALIAS_NFT_CHAIN(AF_INET6, "nat");
145 #endif
146 #ifdef CONFIG_NF_TABLES_INET
147 MODULE_ALIAS_NFT_CHAIN(1, "nat");	/* NFPROTO_INET */
148 #endif
149