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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 union {
14 u8 dreg;
15 };
16};
17
18static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
19 struct nft_regs *regs, struct sock *sk,
20 u32 *dest)
21{
22 switch (nft_pf(pkt)) {
23 case NFPROTO_IPV4:
24 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
25 break;
26#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
27 case NFPROTO_IPV6:
28 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
29 break;
30#endif
31 default:
32 regs->verdict.code = NFT_BREAK;
33 return;
34 }
35}
36
37#ifdef CONFIG_SOCK_CGROUP_DATA
38static noinline bool
39nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level)
40{
41 struct sock *sk = skb_to_full_sk(pkt->skb);
42 struct cgroup *cgrp;
43
44 if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
45 return false;
46
47 cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
48 if (level > cgrp->level)
49 return false;
50
51 memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64));
52
53 return true;
54}
55#endif
56
57static void nft_socket_eval(const struct nft_expr *expr,
58 struct nft_regs *regs,
59 const struct nft_pktinfo *pkt)
60{
61 const struct nft_socket *priv = nft_expr_priv(expr);
62 struct sk_buff *skb = pkt->skb;
63 struct sock *sk = skb->sk;
64 u32 *dest = ®s->data[priv->dreg];
65
66 if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
67 sk = NULL;
68
69 if (!sk)
70 switch(nft_pf(pkt)) {
71 case NFPROTO_IPV4:
72 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
73 break;
74#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
75 case NFPROTO_IPV6:
76 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
77 break;
78#endif
79 default:
80 WARN_ON_ONCE(1);
81 regs->verdict.code = NFT_BREAK;
82 return;
83 }
84
85 if (!sk) {
86 regs->verdict.code = NFT_BREAK;
87 return;
88 }
89
90 switch(priv->key) {
91 case NFT_SOCKET_TRANSPARENT:
92 nft_reg_store8(dest, inet_sk_transparent(sk));
93 break;
94 case NFT_SOCKET_MARK:
95 if (sk_fullsock(sk)) {
96 *dest = sk->sk_mark;
97 } else {
98 regs->verdict.code = NFT_BREAK;
99 return;
100 }
101 break;
102 case NFT_SOCKET_WILDCARD:
103 if (!sk_fullsock(sk)) {
104 regs->verdict.code = NFT_BREAK;
105 return;
106 }
107 nft_socket_wildcard(pkt, regs, sk, dest);
108 break;
109#ifdef CONFIG_SOCK_CGROUP_DATA
110 case NFT_SOCKET_CGROUPV2:
111 if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) {
112 regs->verdict.code = NFT_BREAK;
113 return;
114 }
115 break;
116#endif
117 default:
118 WARN_ON(1);
119 regs->verdict.code = NFT_BREAK;
120 }
121
122 if (sk != skb->sk)
123 sock_gen_put(sk);
124}
125
126static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
127 [NFTA_SOCKET_KEY] = { .type = NLA_U32 },
128 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
129 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 },
130};
131
132static int nft_socket_init(const struct nft_ctx *ctx,
133 const struct nft_expr *expr,
134 const struct nlattr * const tb[])
135{
136 struct nft_socket *priv = nft_expr_priv(expr);
137 unsigned int len;
138
139 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
140 return -EINVAL;
141
142 switch(ctx->family) {
143 case NFPROTO_IPV4:
144#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
145 case NFPROTO_IPV6:
146#endif
147 case NFPROTO_INET:
148 break;
149 default:
150 return -EOPNOTSUPP;
151 }
152
153 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
154 switch(priv->key) {
155 case NFT_SOCKET_TRANSPARENT:
156 case NFT_SOCKET_WILDCARD:
157 len = sizeof(u8);
158 break;
159 case NFT_SOCKET_MARK:
160 len = sizeof(u32);
161 break;
162#ifdef CONFIG_CGROUPS
163 case NFT_SOCKET_CGROUPV2: {
164 unsigned int level;
165
166 if (!tb[NFTA_SOCKET_LEVEL])
167 return -EINVAL;
168
169 level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL]));
170 if (level > 255)
171 return -EOPNOTSUPP;
172
173 priv->level = level;
174 len = sizeof(u64);
175 break;
176 }
177#endif
178 default:
179 return -EOPNOTSUPP;
180 }
181
182 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
183 NULL, NFT_DATA_VALUE, len);
184}
185
186static int nft_socket_dump(struct sk_buff *skb,
187 const struct nft_expr *expr)
188{
189 const struct nft_socket *priv = nft_expr_priv(expr);
190
191 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
192 return -1;
193 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
194 return -1;
195 if (priv->key == NFT_SOCKET_CGROUPV2 &&
196 nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level)))
197 return -1;
198 return 0;
199}
200
201static struct nft_expr_type nft_socket_type;
202static const struct nft_expr_ops nft_socket_ops = {
203 .type = &nft_socket_type,
204 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
205 .eval = nft_socket_eval,
206 .init = nft_socket_init,
207 .dump = nft_socket_dump,
208};
209
210static struct nft_expr_type nft_socket_type __read_mostly = {
211 .name = "socket",
212 .ops = &nft_socket_ops,
213 .policy = nft_socket_policy,
214 .maxattr = NFTA_SOCKET_MAX,
215 .owner = THIS_MODULE,
216};
217
218static int __init nft_socket_module_init(void)
219{
220 return nft_register_expr(&nft_socket_type);
221}
222
223static void __exit nft_socket_module_exit(void)
224{
225 nft_unregister_expr(&nft_socket_type);
226}
227
228module_init(nft_socket_module_init);
229module_exit(nft_socket_module_exit);
230
231MODULE_LICENSE("GPL");
232MODULE_AUTHOR("Máté Eckl");
233MODULE_DESCRIPTION("nf_tables socket match module");
234MODULE_ALIAS_NFT_EXPR("socket");
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, struct sock *sk, const struct nft_pktinfo *pkt, u32 level)
41{
42 struct cgroup *cgrp;
43 u64 cgid;
44
45 if (!sk_fullsock(sk))
46 return false;
47
48 cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level);
49 if (!cgrp)
50 return false;
51
52 cgid = cgroup_id(cgrp);
53 memcpy(dest, &cgid, sizeof(u64));
54 return true;
55}
56#endif
57
58static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt)
59{
60 const struct net_device *indev = nft_in(pkt);
61 const struct sk_buff *skb = pkt->skb;
62 struct sock *sk = NULL;
63
64 if (!indev)
65 return NULL;
66
67 switch (nft_pf(pkt)) {
68 case NFPROTO_IPV4:
69 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev);
70 break;
71#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
72 case NFPROTO_IPV6:
73 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev);
74 break;
75#endif
76 default:
77 WARN_ON_ONCE(1);
78 break;
79 }
80
81 return sk;
82}
83
84static void nft_socket_eval(const struct nft_expr *expr,
85 struct nft_regs *regs,
86 const struct nft_pktinfo *pkt)
87{
88 const struct nft_socket *priv = nft_expr_priv(expr);
89 struct sk_buff *skb = pkt->skb;
90 struct sock *sk = skb->sk;
91 u32 *dest = ®s->data[priv->dreg];
92
93 if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
94 sk = NULL;
95
96 if (!sk)
97 sk = nft_socket_do_lookup(pkt);
98
99 if (!sk) {
100 regs->verdict.code = NFT_BREAK;
101 return;
102 }
103
104 switch(priv->key) {
105 case NFT_SOCKET_TRANSPARENT:
106 nft_reg_store8(dest, inet_sk_transparent(sk));
107 break;
108 case NFT_SOCKET_MARK:
109 if (sk_fullsock(sk)) {
110 *dest = READ_ONCE(sk->sk_mark);
111 } else {
112 regs->verdict.code = NFT_BREAK;
113 return;
114 }
115 break;
116 case NFT_SOCKET_WILDCARD:
117 if (!sk_fullsock(sk)) {
118 regs->verdict.code = NFT_BREAK;
119 return;
120 }
121 nft_socket_wildcard(pkt, regs, sk, dest);
122 break;
123#ifdef CONFIG_SOCK_CGROUP_DATA
124 case NFT_SOCKET_CGROUPV2:
125 if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) {
126 regs->verdict.code = NFT_BREAK;
127 return;
128 }
129 break;
130#endif
131 default:
132 WARN_ON(1);
133 regs->verdict.code = NFT_BREAK;
134 }
135
136 if (sk != skb->sk)
137 sock_gen_put(sk);
138}
139
140static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
141 [NFTA_SOCKET_KEY] = NLA_POLICY_MAX(NLA_BE32, 255),
142 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
143 [NFTA_SOCKET_LEVEL] = NLA_POLICY_MAX(NLA_BE32, 255),
144};
145
146static int nft_socket_init(const struct nft_ctx *ctx,
147 const struct nft_expr *expr,
148 const struct nlattr * const tb[])
149{
150 struct nft_socket *priv = nft_expr_priv(expr);
151 unsigned int len;
152
153 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
154 return -EINVAL;
155
156 switch(ctx->family) {
157 case NFPROTO_IPV4:
158#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
159 case NFPROTO_IPV6:
160#endif
161 case NFPROTO_INET:
162 break;
163 default:
164 return -EOPNOTSUPP;
165 }
166
167 priv->key = ntohl(nla_get_be32(tb[NFTA_SOCKET_KEY]));
168 switch(priv->key) {
169 case NFT_SOCKET_TRANSPARENT:
170 case NFT_SOCKET_WILDCARD:
171 len = sizeof(u8);
172 break;
173 case NFT_SOCKET_MARK:
174 len = sizeof(u32);
175 break;
176#ifdef CONFIG_CGROUPS
177 case NFT_SOCKET_CGROUPV2: {
178 unsigned int level;
179
180 if (!tb[NFTA_SOCKET_LEVEL])
181 return -EINVAL;
182
183 level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL]));
184 if (level > 255)
185 return -EOPNOTSUPP;
186
187 priv->level = level;
188 len = sizeof(u64);
189 break;
190 }
191#endif
192 default:
193 return -EOPNOTSUPP;
194 }
195
196 priv->len = len;
197 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
198 NULL, NFT_DATA_VALUE, len);
199}
200
201static int nft_socket_dump(struct sk_buff *skb,
202 const struct nft_expr *expr, bool reset)
203{
204 const struct nft_socket *priv = nft_expr_priv(expr);
205
206 if (nla_put_be32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
207 return -1;
208 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
209 return -1;
210 if (priv->key == NFT_SOCKET_CGROUPV2 &&
211 nla_put_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level)))
212 return -1;
213 return 0;
214}
215
216static bool nft_socket_reduce(struct nft_regs_track *track,
217 const struct nft_expr *expr)
218{
219 const struct nft_socket *priv = nft_expr_priv(expr);
220 const struct nft_socket *socket;
221
222 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
223 nft_reg_track_update(track, expr, priv->dreg, priv->len);
224 return false;
225 }
226
227 socket = nft_expr_priv(track->regs[priv->dreg].selector);
228 if (priv->key != socket->key ||
229 priv->dreg != socket->dreg ||
230 priv->level != socket->level) {
231 nft_reg_track_update(track, expr, priv->dreg, priv->len);
232 return false;
233 }
234
235 if (!track->regs[priv->dreg].bitwise)
236 return true;
237
238 return nft_expr_reduce_bitwise(track, expr);
239}
240
241static int nft_socket_validate(const struct nft_ctx *ctx,
242 const struct nft_expr *expr,
243 const struct nft_data **data)
244{
245 if (ctx->family != NFPROTO_IPV4 &&
246 ctx->family != NFPROTO_IPV6 &&
247 ctx->family != NFPROTO_INET)
248 return -EOPNOTSUPP;
249
250 return nft_chain_validate_hooks(ctx->chain,
251 (1 << NF_INET_PRE_ROUTING) |
252 (1 << NF_INET_LOCAL_IN) |
253 (1 << NF_INET_LOCAL_OUT));
254}
255
256static struct nft_expr_type nft_socket_type;
257static const struct nft_expr_ops nft_socket_ops = {
258 .type = &nft_socket_type,
259 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
260 .eval = nft_socket_eval,
261 .init = nft_socket_init,
262 .dump = nft_socket_dump,
263 .validate = nft_socket_validate,
264 .reduce = nft_socket_reduce,
265};
266
267static struct nft_expr_type nft_socket_type __read_mostly = {
268 .name = "socket",
269 .ops = &nft_socket_ops,
270 .policy = nft_socket_policy,
271 .maxattr = NFTA_SOCKET_MAX,
272 .owner = THIS_MODULE,
273};
274
275static int __init nft_socket_module_init(void)
276{
277 return nft_register_expr(&nft_socket_type);
278}
279
280static void __exit nft_socket_module_exit(void)
281{
282 nft_unregister_expr(&nft_socket_type);
283}
284
285module_init(nft_socket_module_init);
286module_exit(nft_socket_module_exit);
287
288MODULE_LICENSE("GPL");
289MODULE_AUTHOR("Máté Eckl");
290MODULE_DESCRIPTION("nf_tables socket match module");
291MODULE_ALIAS_NFT_EXPR("socket");