Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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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)
27 switch(nft_pf(pkt)) {
28 case NFPROTO_IPV4:
29 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
30 break;
31#if IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
32 case NFPROTO_IPV6:
33 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
34 break;
35#endif
36 default:
37 WARN_ON_ONCE(1);
38 regs->verdict.code = NFT_BREAK;
39 return;
40 }
41
42 if(!sk) {
43 nft_reg_store8(dest, 0);
44 return;
45 }
46
47 /* So that subsequent socket matching not to require other lookups. */
48 skb->sk = sk;
49
50 switch(priv->key) {
51 case NFT_SOCKET_TRANSPARENT:
52 nft_reg_store8(dest, inet_sk_transparent(sk));
53 break;
54 default:
55 WARN_ON(1);
56 regs->verdict.code = NFT_BREAK;
57 }
58}
59
60static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
61 [NFTA_SOCKET_KEY] = { .type = NLA_U32 },
62 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
63};
64
65static int nft_socket_init(const struct nft_ctx *ctx,
66 const struct nft_expr *expr,
67 const struct nlattr * const tb[])
68{
69 struct nft_socket *priv = nft_expr_priv(expr);
70 unsigned int len;
71
72 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
73 return -EINVAL;
74
75 switch(ctx->family) {
76 case NFPROTO_IPV4:
77#if IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
78 case NFPROTO_IPV6:
79#endif
80 case NFPROTO_INET:
81 break;
82 default:
83 return -EOPNOTSUPP;
84 }
85
86 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
87 switch(priv->key) {
88 case NFT_SOCKET_TRANSPARENT:
89 len = sizeof(u8);
90 break;
91 default:
92 return -EOPNOTSUPP;
93 }
94
95 priv->dreg = nft_parse_register(tb[NFTA_SOCKET_DREG]);
96 return nft_validate_register_store(ctx, priv->dreg, NULL,
97 NFT_DATA_VALUE, len);
98}
99
100static int nft_socket_dump(struct sk_buff *skb,
101 const struct nft_expr *expr)
102{
103 const struct nft_socket *priv = nft_expr_priv(expr);
104
105 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
106 return -1;
107 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
108 return -1;
109 return 0;
110}
111
112static struct nft_expr_type nft_socket_type;
113static const struct nft_expr_ops nft_socket_ops = {
114 .type = &nft_socket_type,
115 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
116 .eval = nft_socket_eval,
117 .init = nft_socket_init,
118 .dump = nft_socket_dump,
119};
120
121static struct nft_expr_type nft_socket_type __read_mostly = {
122 .name = "socket",
123 .ops = &nft_socket_ops,
124 .policy = nft_socket_policy,
125 .maxattr = NFTA_SOCKET_MAX,
126 .owner = THIS_MODULE,
127};
128
129static int __init nft_socket_module_init(void)
130{
131 return nft_register_expr(&nft_socket_type);
132}
133
134static void __exit nft_socket_module_exit(void)
135{
136 nft_unregister_expr(&nft_socket_type);
137}
138
139module_init(nft_socket_module_init);
140module_exit(nft_socket_module_exit);
141
142MODULE_LICENSE("GPL");
143MODULE_AUTHOR("Máté Eckl");
144MODULE_DESCRIPTION("nf_tables socket match module");
145MODULE_ALIAS_NFT_EXPR("socket");