1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/module.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_socket.h>
#include <net/inet_sock.h>
#include <net/tcp.h>
struct nft_socket {
enum nft_socket_keys key:8;
u8 level;
union {
u8 dreg;
};
};
static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
struct nft_regs *regs, struct sock *sk,
u32 *dest)
{
switch (nft_pf(pkt)) {
case NFPROTO_IPV4:
nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
break;
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
case NFPROTO_IPV6:
nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
break;
#endif
default:
regs->verdict.code = NFT_BREAK;
return;
}
}
#ifdef CONFIG_CGROUPS
static noinline bool
nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level)
{
struct sock *sk = skb_to_full_sk(pkt->skb);
struct cgroup *cgrp;
if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
return false;
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
if (level > cgrp->level)
return false;
memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64));
return true;
}
#endif
static void nft_socket_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_socket *priv = nft_expr_priv(expr);
struct sk_buff *skb = pkt->skb;
struct sock *sk = skb->sk;
u32 *dest = ®s->data[priv->dreg];
if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
sk = NULL;
if (!sk)
switch(nft_pf(pkt)) {
case NFPROTO_IPV4:
sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
break;
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
case NFPROTO_IPV6:
sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
break;
#endif
default:
WARN_ON_ONCE(1);
regs->verdict.code = NFT_BREAK;
return;
}
if (!sk) {
regs->verdict.code = NFT_BREAK;
return;
}
switch(priv->key) {
case NFT_SOCKET_TRANSPARENT:
nft_reg_store8(dest, inet_sk_transparent(sk));
break;
case NFT_SOCKET_MARK:
if (sk_fullsock(sk)) {
*dest = sk->sk_mark;
} else {
regs->verdict.code = NFT_BREAK;
return;
}
break;
case NFT_SOCKET_WILDCARD:
if (!sk_fullsock(sk)) {
regs->verdict.code = NFT_BREAK;
return;
}
nft_socket_wildcard(pkt, regs, sk, dest);
break;
#ifdef CONFIG_CGROUPS
case NFT_SOCKET_CGROUPV2:
if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) {
regs->verdict.code = NFT_BREAK;
return;
}
break;
#endif
default:
WARN_ON(1);
regs->verdict.code = NFT_BREAK;
}
if (sk != skb->sk)
sock_gen_put(sk);
}
static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
[NFTA_SOCKET_KEY] = { .type = NLA_U32 },
[NFTA_SOCKET_DREG] = { .type = NLA_U32 },
[NFTA_SOCKET_LEVEL] = { .type = NLA_U32 },
};
static int nft_socket_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_socket *priv = nft_expr_priv(expr);
unsigned int len;
if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
return -EINVAL;
switch(ctx->family) {
case NFPROTO_IPV4:
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
case NFPROTO_IPV6:
#endif
case NFPROTO_INET:
break;
default:
return -EOPNOTSUPP;
}
priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
switch(priv->key) {
case NFT_SOCKET_TRANSPARENT:
case NFT_SOCKET_WILDCARD:
len = sizeof(u8);
break;
case NFT_SOCKET_MARK:
len = sizeof(u32);
break;
#ifdef CONFIG_CGROUPS
case NFT_SOCKET_CGROUPV2: {
unsigned int level;
if (!tb[NFTA_SOCKET_LEVEL])
return -EINVAL;
level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL]));
if (level > 255)
return -EOPNOTSUPP;
priv->level = level;
len = sizeof(u64);
break;
}
#endif
default:
return -EOPNOTSUPP;
}
return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
NULL, NFT_DATA_VALUE, len);
}
static int nft_socket_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_socket *priv = nft_expr_priv(expr);
if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
return -1;
if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
return -1;
if (priv->key == NFT_SOCKET_CGROUPV2 &&
nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level)))
return -1;
return 0;
}
static struct nft_expr_type nft_socket_type;
static const struct nft_expr_ops nft_socket_ops = {
.type = &nft_socket_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
.eval = nft_socket_eval,
.init = nft_socket_init,
.dump = nft_socket_dump,
};
static struct nft_expr_type nft_socket_type __read_mostly = {
.name = "socket",
.ops = &nft_socket_ops,
.policy = nft_socket_policy,
.maxattr = NFTA_SOCKET_MAX,
.owner = THIS_MODULE,
};
static int __init nft_socket_module_init(void)
{
return nft_register_expr(&nft_socket_type);
}
static void __exit nft_socket_module_exit(void)
{
nft_unregister_expr(&nft_socket_type);
}
module_init(nft_socket_module_init);
module_exit(nft_socket_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Máté Eckl");
MODULE_DESCRIPTION("nf_tables socket match module");
MODULE_ALIAS_NFT_EXPR("socket");
|
