Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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 u8 level;
13 u8 len;
14 union {
15 u8 dreg;
16 };
17};
18
19static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
20 struct nft_regs *regs, struct sock *sk,
21 u32 *dest)
22{
23 switch (nft_pf(pkt)) {
24 case NFPROTO_IPV4:
25 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
26 break;
27#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
28 case NFPROTO_IPV6:
29 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
30 break;
31#endif
32 default:
33 regs->verdict.code = NFT_BREAK;
34 return;
35 }
36}
37
38#ifdef CONFIG_SOCK_CGROUP_DATA
39static noinline bool
40nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level)
41{
42 struct sock *sk = skb_to_full_sk(pkt->skb);
43 struct cgroup *cgrp;
44
45 if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
46 return false;
47
48 cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
49 if (level > cgrp->level)
50 return false;
51
52 memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64));
53
54 return true;
55}
56#endif
57
58static void nft_socket_eval(const struct nft_expr *expr,
59 struct nft_regs *regs,
60 const struct nft_pktinfo *pkt)
61{
62 const struct nft_socket *priv = nft_expr_priv(expr);
63 struct sk_buff *skb = pkt->skb;
64 struct sock *sk = skb->sk;
65 u32 *dest = ®s->data[priv->dreg];
66
67 if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
68 sk = NULL;
69
70 if (!sk)
71 switch(nft_pf(pkt)) {
72 case NFPROTO_IPV4:
73 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
74 break;
75#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
76 case NFPROTO_IPV6:
77 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
78 break;
79#endif
80 default:
81 WARN_ON_ONCE(1);
82 regs->verdict.code = NFT_BREAK;
83 return;
84 }
85
86 if (!sk) {
87 regs->verdict.code = NFT_BREAK;
88 return;
89 }
90
91 switch(priv->key) {
92 case NFT_SOCKET_TRANSPARENT:
93 nft_reg_store8(dest, inet_sk_transparent(sk));
94 break;
95 case NFT_SOCKET_MARK:
96 if (sk_fullsock(sk)) {
97 *dest = sk->sk_mark;
98 } else {
99 regs->verdict.code = NFT_BREAK;
100 return;
101 }
102 break;
103 case NFT_SOCKET_WILDCARD:
104 if (!sk_fullsock(sk)) {
105 regs->verdict.code = NFT_BREAK;
106 return;
107 }
108 nft_socket_wildcard(pkt, regs, sk, dest);
109 break;
110#ifdef CONFIG_SOCK_CGROUP_DATA
111 case NFT_SOCKET_CGROUPV2:
112 if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) {
113 regs->verdict.code = NFT_BREAK;
114 return;
115 }
116 break;
117#endif
118 default:
119 WARN_ON(1);
120 regs->verdict.code = NFT_BREAK;
121 }
122
123 if (sk != skb->sk)
124 sock_gen_put(sk);
125}
126
127static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
128 [NFTA_SOCKET_KEY] = { .type = NLA_U32 },
129 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
130 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 },
131};
132
133static int nft_socket_init(const struct nft_ctx *ctx,
134 const struct nft_expr *expr,
135 const struct nlattr * const tb[])
136{
137 struct nft_socket *priv = nft_expr_priv(expr);
138 unsigned int len;
139
140 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
141 return -EINVAL;
142
143 switch(ctx->family) {
144 case NFPROTO_IPV4:
145#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
146 case NFPROTO_IPV6:
147#endif
148 case NFPROTO_INET:
149 break;
150 default:
151 return -EOPNOTSUPP;
152 }
153
154 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
155 switch(priv->key) {
156 case NFT_SOCKET_TRANSPARENT:
157 case NFT_SOCKET_WILDCARD:
158 len = sizeof(u8);
159 break;
160 case NFT_SOCKET_MARK:
161 len = sizeof(u32);
162 break;
163#ifdef CONFIG_CGROUPS
164 case NFT_SOCKET_CGROUPV2: {
165 unsigned int level;
166
167 if (!tb[NFTA_SOCKET_LEVEL])
168 return -EINVAL;
169
170 level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL]));
171 if (level > 255)
172 return -EOPNOTSUPP;
173
174 priv->level = level;
175 len = sizeof(u64);
176 break;
177 }
178#endif
179 default:
180 return -EOPNOTSUPP;
181 }
182
183 priv->len = len;
184 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
185 NULL, NFT_DATA_VALUE, len);
186}
187
188static int nft_socket_dump(struct sk_buff *skb,
189 const struct nft_expr *expr)
190{
191 const struct nft_socket *priv = nft_expr_priv(expr);
192
193 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
194 return -1;
195 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
196 return -1;
197 if (priv->key == NFT_SOCKET_CGROUPV2 &&
198 nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level)))
199 return -1;
200 return 0;
201}
202
203static bool nft_socket_reduce(struct nft_regs_track *track,
204 const struct nft_expr *expr)
205{
206 const struct nft_socket *priv = nft_expr_priv(expr);
207 const struct nft_socket *socket;
208
209 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
210 nft_reg_track_update(track, expr, priv->dreg, priv->len);
211 return false;
212 }
213
214 socket = nft_expr_priv(track->regs[priv->dreg].selector);
215 if (priv->key != socket->key ||
216 priv->dreg != socket->dreg ||
217 priv->level != socket->level) {
218 nft_reg_track_update(track, expr, priv->dreg, priv->len);
219 return false;
220 }
221
222 if (!track->regs[priv->dreg].bitwise)
223 return true;
224
225 return nft_expr_reduce_bitwise(track, expr);
226}
227
228static struct nft_expr_type nft_socket_type;
229static const struct nft_expr_ops nft_socket_ops = {
230 .type = &nft_socket_type,
231 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
232 .eval = nft_socket_eval,
233 .init = nft_socket_init,
234 .dump = nft_socket_dump,
235 .reduce = nft_socket_reduce,
236};
237
238static struct nft_expr_type nft_socket_type __read_mostly = {
239 .name = "socket",
240 .ops = &nft_socket_ops,
241 .policy = nft_socket_policy,
242 .maxattr = NFTA_SOCKET_MAX,
243 .owner = THIS_MODULE,
244};
245
246static int __init nft_socket_module_init(void)
247{
248 return nft_register_expr(&nft_socket_type);
249}
250
251static void __exit nft_socket_module_exit(void)
252{
253 nft_unregister_expr(&nft_socket_type);
254}
255
256module_init(nft_socket_module_init);
257module_exit(nft_socket_module_exit);
258
259MODULE_LICENSE("GPL");
260MODULE_AUTHOR("Máté Eckl");
261MODULE_DESCRIPTION("nf_tables socket match module");
262MODULE_ALIAS_NFT_EXPR("socket");