Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/module.h>
3#include <linux/netfilter/nf_tables.h>
4#include <net/netfilter/nf_tables.h>
5#include <net/netfilter/nf_tables_core.h>
6#include <net/netfilter/nf_socket.h>
7#include <net/inet_sock.h>
8#include <net/tcp.h>
9
10struct nft_socket {
11 enum nft_socket_keys key:8;
12 union {
13 enum nft_registers dreg:8;
14 };
15};
16
17static void nft_socket_eval(const struct nft_expr *expr,
18 struct nft_regs *regs,
19 const struct nft_pktinfo *pkt)
20{
21 const struct nft_socket *priv = nft_expr_priv(expr);
22 struct sk_buff *skb = pkt->skb;
23 struct sock *sk = skb->sk;
24 u32 *dest = ®s->data[priv->dreg];
25
26 if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
27 sk = NULL;
28
29 if (!sk)
30 switch(nft_pf(pkt)) {
31 case NFPROTO_IPV4:
32 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
33 break;
34#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
35 case NFPROTO_IPV6:
36 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
37 break;
38#endif
39 default:
40 WARN_ON_ONCE(1);
41 regs->verdict.code = NFT_BREAK;
42 return;
43 }
44
45 if (!sk) {
46 regs->verdict.code = NFT_BREAK;
47 return;
48 }
49
50 /* So that subsequent socket matching not to require other lookups. */
51 skb->sk = sk;
52
53 switch(priv->key) {
54 case NFT_SOCKET_TRANSPARENT:
55 nft_reg_store8(dest, inet_sk_transparent(sk));
56 break;
57 case NFT_SOCKET_MARK:
58 if (sk_fullsock(sk)) {
59 *dest = sk->sk_mark;
60 } else {
61 regs->verdict.code = NFT_BREAK;
62 return;
63 }
64 break;
65 default:
66 WARN_ON(1);
67 regs->verdict.code = NFT_BREAK;
68 }
69}
70
71static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
72 [NFTA_SOCKET_KEY] = { .type = NLA_U32 },
73 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
74};
75
76static int nft_socket_init(const struct nft_ctx *ctx,
77 const struct nft_expr *expr,
78 const struct nlattr * const tb[])
79{
80 struct nft_socket *priv = nft_expr_priv(expr);
81 unsigned int len;
82
83 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
84 return -EINVAL;
85
86 switch(ctx->family) {
87 case NFPROTO_IPV4:
88#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
89 case NFPROTO_IPV6:
90#endif
91 case NFPROTO_INET:
92 break;
93 default:
94 return -EOPNOTSUPP;
95 }
96
97 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
98 switch(priv->key) {
99 case NFT_SOCKET_TRANSPARENT:
100 len = sizeof(u8);
101 break;
102 case NFT_SOCKET_MARK:
103 len = sizeof(u32);
104 break;
105 default:
106 return -EOPNOTSUPP;
107 }
108
109 priv->dreg = nft_parse_register(tb[NFTA_SOCKET_DREG]);
110 return nft_validate_register_store(ctx, priv->dreg, NULL,
111 NFT_DATA_VALUE, len);
112}
113
114static int nft_socket_dump(struct sk_buff *skb,
115 const struct nft_expr *expr)
116{
117 const struct nft_socket *priv = nft_expr_priv(expr);
118
119 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
120 return -1;
121 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
122 return -1;
123 return 0;
124}
125
126static struct nft_expr_type nft_socket_type;
127static const struct nft_expr_ops nft_socket_ops = {
128 .type = &nft_socket_type,
129 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
130 .eval = nft_socket_eval,
131 .init = nft_socket_init,
132 .dump = nft_socket_dump,
133};
134
135static struct nft_expr_type nft_socket_type __read_mostly = {
136 .name = "socket",
137 .ops = &nft_socket_ops,
138 .policy = nft_socket_policy,
139 .maxattr = NFTA_SOCKET_MAX,
140 .owner = THIS_MODULE,
141};
142
143static int __init nft_socket_module_init(void)
144{
145 return nft_register_expr(&nft_socket_type);
146}
147
148static void __exit nft_socket_module_exit(void)
149{
150 nft_unregister_expr(&nft_socket_type);
151}
152
153module_init(nft_socket_module_init);
154module_exit(nft_socket_module_exit);
155
156MODULE_LICENSE("GPL");
157MODULE_AUTHOR("Máté Eckl");
158MODULE_DESCRIPTION("nf_tables socket match module");
159MODULE_ALIAS_NFT_EXPR("socket");