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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; /* cgroupv2 level to extract */
13 u8 level_user; /* cgroupv2 level provided by userspace */
14 u8 len;
15 union {
16 u8 dreg;
17 };
18};
19
20static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
21 struct nft_regs *regs, struct sock *sk,
22 u32 *dest)
23{
24 switch (nft_pf(pkt)) {
25 case NFPROTO_IPV4:
26 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
27 break;
28#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
29 case NFPROTO_IPV6:
30 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
31 break;
32#endif
33 default:
34 regs->verdict.code = NFT_BREAK;
35 return;
36 }
37}
38
39#ifdef CONFIG_SOCK_CGROUP_DATA
40static noinline bool
41nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level)
42{
43 struct cgroup *cgrp;
44 u64 cgid;
45
46 if (!sk_fullsock(sk))
47 return false;
48
49 cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level);
50 if (!cgrp)
51 return false;
52
53 cgid = cgroup_id(cgrp);
54 memcpy(dest, &cgid, sizeof(u64));
55 return true;
56}
57
58/* process context only, uses current->nsproxy. */
59static noinline int nft_socket_cgroup_subtree_level(void)
60{
61 struct cgroup *cgrp = cgroup_get_from_path("/");
62 int level;
63
64 if (IS_ERR(cgrp))
65 return PTR_ERR(cgrp);
66
67 level = cgrp->level;
68
69 cgroup_put(cgrp);
70
71 if (level > 255)
72 return -ERANGE;
73
74 if (WARN_ON_ONCE(level < 0))
75 return -EINVAL;
76
77 return level;
78}
79#endif
80
81static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt)
82{
83 const struct net_device *indev = nft_in(pkt);
84 const struct sk_buff *skb = pkt->skb;
85 struct sock *sk = NULL;
86
87 if (!indev)
88 return NULL;
89
90 switch (nft_pf(pkt)) {
91 case NFPROTO_IPV4:
92 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev);
93 break;
94#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
95 case NFPROTO_IPV6:
96 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev);
97 break;
98#endif
99 default:
100 WARN_ON_ONCE(1);
101 break;
102 }
103
104 return sk;
105}
106
107static void nft_socket_eval(const struct nft_expr *expr,
108 struct nft_regs *regs,
109 const struct nft_pktinfo *pkt)
110{
111 const struct nft_socket *priv = nft_expr_priv(expr);
112 struct sk_buff *skb = pkt->skb;
113 struct sock *sk = skb->sk;
114 u32 *dest = ®s->data[priv->dreg];
115
116 if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
117 sk = NULL;
118
119 if (!sk)
120 sk = nft_socket_do_lookup(pkt);
121
122 if (!sk) {
123 regs->verdict.code = NFT_BREAK;
124 return;
125 }
126
127 switch(priv->key) {
128 case NFT_SOCKET_TRANSPARENT:
129 nft_reg_store8(dest, inet_sk_transparent(sk));
130 break;
131 case NFT_SOCKET_MARK:
132 if (sk_fullsock(sk)) {
133 *dest = READ_ONCE(sk->sk_mark);
134 } else {
135 regs->verdict.code = NFT_BREAK;
136 goto out_put_sk;
137 }
138 break;
139 case NFT_SOCKET_WILDCARD:
140 if (!sk_fullsock(sk)) {
141 regs->verdict.code = NFT_BREAK;
142 goto out_put_sk;
143 }
144 nft_socket_wildcard(pkt, regs, sk, dest);
145 break;
146#ifdef CONFIG_SOCK_CGROUP_DATA
147 case NFT_SOCKET_CGROUPV2:
148 if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) {
149 regs->verdict.code = NFT_BREAK;
150 goto out_put_sk;
151 }
152 break;
153#endif
154 default:
155 WARN_ON(1);
156 regs->verdict.code = NFT_BREAK;
157 }
158
159out_put_sk:
160 if (sk != skb->sk)
161 sock_gen_put(sk);
162}
163
164static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
165 [NFTA_SOCKET_KEY] = NLA_POLICY_MAX(NLA_BE32, 255),
166 [NFTA_SOCKET_DREG] = { .type = NLA_U32 },
167 [NFTA_SOCKET_LEVEL] = NLA_POLICY_MAX(NLA_BE32, 255),
168};
169
170static int nft_socket_init(const struct nft_ctx *ctx,
171 const struct nft_expr *expr,
172 const struct nlattr * const tb[])
173{
174 struct nft_socket *priv = nft_expr_priv(expr);
175 unsigned int len;
176
177 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
178 return -EINVAL;
179
180 switch(ctx->family) {
181 case NFPROTO_IPV4:
182#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
183 case NFPROTO_IPV6:
184#endif
185 case NFPROTO_INET:
186 break;
187 default:
188 return -EOPNOTSUPP;
189 }
190
191 priv->key = ntohl(nla_get_be32(tb[NFTA_SOCKET_KEY]));
192 switch(priv->key) {
193 case NFT_SOCKET_TRANSPARENT:
194 case NFT_SOCKET_WILDCARD:
195 len = sizeof(u8);
196 break;
197 case NFT_SOCKET_MARK:
198 len = sizeof(u32);
199 break;
200#ifdef CONFIG_SOCK_CGROUP_DATA
201 case NFT_SOCKET_CGROUPV2: {
202 unsigned int level;
203 int err;
204
205 if (!tb[NFTA_SOCKET_LEVEL])
206 return -EINVAL;
207
208 level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL]));
209 if (level > 255)
210 return -EOPNOTSUPP;
211
212 err = nft_socket_cgroup_subtree_level();
213 if (err < 0)
214 return err;
215
216 priv->level_user = level;
217
218 level += err;
219 /* Implies a giant cgroup tree */
220 if (WARN_ON_ONCE(level > 255))
221 return -EOPNOTSUPP;
222
223 priv->level = level;
224 len = sizeof(u64);
225 break;
226 }
227#endif
228 default:
229 return -EOPNOTSUPP;
230 }
231
232 priv->len = len;
233 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
234 NULL, NFT_DATA_VALUE, len);
235}
236
237static int nft_socket_dump(struct sk_buff *skb,
238 const struct nft_expr *expr, bool reset)
239{
240 const struct nft_socket *priv = nft_expr_priv(expr);
241
242 if (nla_put_be32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
243 return -1;
244 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
245 return -1;
246 if (priv->key == NFT_SOCKET_CGROUPV2 &&
247 nla_put_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level_user)))
248 return -1;
249 return 0;
250}
251
252static bool nft_socket_reduce(struct nft_regs_track *track,
253 const struct nft_expr *expr)
254{
255 const struct nft_socket *priv = nft_expr_priv(expr);
256 const struct nft_socket *socket;
257
258 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
259 nft_reg_track_update(track, expr, priv->dreg, priv->len);
260 return false;
261 }
262
263 socket = nft_expr_priv(track->regs[priv->dreg].selector);
264 if (priv->key != socket->key ||
265 priv->dreg != socket->dreg ||
266 priv->level != socket->level) {
267 nft_reg_track_update(track, expr, priv->dreg, priv->len);
268 return false;
269 }
270
271 if (!track->regs[priv->dreg].bitwise)
272 return true;
273
274 return nft_expr_reduce_bitwise(track, expr);
275}
276
277static int nft_socket_validate(const struct nft_ctx *ctx,
278 const struct nft_expr *expr)
279{
280 if (ctx->family != NFPROTO_IPV4 &&
281 ctx->family != NFPROTO_IPV6 &&
282 ctx->family != NFPROTO_INET)
283 return -EOPNOTSUPP;
284
285 return nft_chain_validate_hooks(ctx->chain,
286 (1 << NF_INET_PRE_ROUTING) |
287 (1 << NF_INET_LOCAL_IN) |
288 (1 << NF_INET_LOCAL_OUT));
289}
290
291static struct nft_expr_type nft_socket_type;
292static const struct nft_expr_ops nft_socket_ops = {
293 .type = &nft_socket_type,
294 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
295 .eval = nft_socket_eval,
296 .init = nft_socket_init,
297 .dump = nft_socket_dump,
298 .validate = nft_socket_validate,
299 .reduce = nft_socket_reduce,
300};
301
302static struct nft_expr_type nft_socket_type __read_mostly = {
303 .name = "socket",
304 .ops = &nft_socket_ops,
305 .policy = nft_socket_policy,
306 .maxattr = NFTA_SOCKET_MAX,
307 .owner = THIS_MODULE,
308};
309
310static int __init nft_socket_module_init(void)
311{
312 return nft_register_expr(&nft_socket_type);
313}
314
315static void __exit nft_socket_module_exit(void)
316{
317 nft_unregister_expr(&nft_socket_type);
318}
319
320module_init(nft_socket_module_init);
321module_exit(nft_socket_module_exit);
322
323MODULE_LICENSE("GPL");
324MODULE_AUTHOR("Máté Eckl");
325MODULE_DESCRIPTION("nf_tables socket match module");
326MODULE_ALIAS_NFT_EXPR("socket");