tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/netlink.h>
15#include <linux/netfilter.h>
16#include <linux/netfilter/nf_tables.h>
17#include <net/dst.h>
18#include <net/sock.h>
19#include <net/tcp_states.h> /* for TCP_TIME_WAIT */
20#include <net/netfilter/nf_tables.h>
21
22struct nft_meta {
23 enum nft_meta_keys key:8;
24 enum nft_registers dreg:8;
25};
26
27static void nft_meta_eval(const struct nft_expr *expr,
28 struct nft_data data[NFT_REG_MAX + 1],
29 const struct nft_pktinfo *pkt)
30{
31 const struct nft_meta *priv = nft_expr_priv(expr);
32 const struct sk_buff *skb = pkt->skb;
33 const struct net_device *in = pkt->in, *out = pkt->out;
34 struct nft_data *dest = &data[priv->dreg];
35
36 switch (priv->key) {
37 case NFT_META_LEN:
38 dest->data[0] = skb->len;
39 break;
40 case NFT_META_PROTOCOL:
41 *(__be16 *)dest->data = skb->protocol;
42 break;
43 case NFT_META_PRIORITY:
44 dest->data[0] = skb->priority;
45 break;
46 case NFT_META_MARK:
47 dest->data[0] = skb->mark;
48 break;
49 case NFT_META_IIF:
50 if (in == NULL)
51 goto err;
52 dest->data[0] = in->ifindex;
53 break;
54 case NFT_META_OIF:
55 if (out == NULL)
56 goto err;
57 dest->data[0] = out->ifindex;
58 break;
59 case NFT_META_IIFNAME:
60 if (in == NULL)
61 goto err;
62 strncpy((char *)dest->data, in->name, sizeof(dest->data));
63 break;
64 case NFT_META_OIFNAME:
65 if (out == NULL)
66 goto err;
67 strncpy((char *)dest->data, out->name, sizeof(dest->data));
68 break;
69 case NFT_META_IIFTYPE:
70 if (in == NULL)
71 goto err;
72 *(u16 *)dest->data = in->type;
73 break;
74 case NFT_META_OIFTYPE:
75 if (out == NULL)
76 goto err;
77 *(u16 *)dest->data = out->type;
78 break;
79 case NFT_META_SKUID:
80 if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
81 goto err;
82
83 read_lock_bh(&skb->sk->sk_callback_lock);
84 if (skb->sk->sk_socket == NULL ||
85 skb->sk->sk_socket->file == NULL) {
86 read_unlock_bh(&skb->sk->sk_callback_lock);
87 goto err;
88 }
89
90 dest->data[0] =
91 from_kuid_munged(&init_user_ns,
92 skb->sk->sk_socket->file->f_cred->fsuid);
93 read_unlock_bh(&skb->sk->sk_callback_lock);
94 break;
95 case NFT_META_SKGID:
96 if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
97 goto err;
98
99 read_lock_bh(&skb->sk->sk_callback_lock);
100 if (skb->sk->sk_socket == NULL ||
101 skb->sk->sk_socket->file == NULL) {
102 read_unlock_bh(&skb->sk->sk_callback_lock);
103 goto err;
104 }
105 dest->data[0] =
106 from_kgid_munged(&init_user_ns,
107 skb->sk->sk_socket->file->f_cred->fsgid);
108 read_unlock_bh(&skb->sk->sk_callback_lock);
109 break;
110#ifdef CONFIG_NET_CLS_ROUTE
111 case NFT_META_RTCLASSID: {
112 const struct dst_entry *dst = skb_dst(skb);
113
114 if (dst == NULL)
115 goto err;
116 dest->data[0] = dst->tclassid;
117 break;
118 }
119#endif
120#ifdef CONFIG_NETWORK_SECMARK
121 case NFT_META_SECMARK:
122 dest->data[0] = skb->secmark;
123 break;
124#endif
125 default:
126 WARN_ON(1);
127 goto err;
128 }
129 return;
130
131err:
132 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
133}
134
135static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
136 [NFTA_META_DREG] = { .type = NLA_U32 },
137 [NFTA_META_KEY] = { .type = NLA_U32 },
138};
139
140static int nft_meta_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
141 const struct nlattr * const tb[])
142{
143 struct nft_meta *priv = nft_expr_priv(expr);
144 int err;
145
146 if (tb[NFTA_META_DREG] == NULL ||
147 tb[NFTA_META_KEY] == NULL)
148 return -EINVAL;
149
150 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
151 switch (priv->key) {
152 case NFT_META_LEN:
153 case NFT_META_PROTOCOL:
154 case NFT_META_PRIORITY:
155 case NFT_META_MARK:
156 case NFT_META_IIF:
157 case NFT_META_OIF:
158 case NFT_META_IIFNAME:
159 case NFT_META_OIFNAME:
160 case NFT_META_IIFTYPE:
161 case NFT_META_OIFTYPE:
162 case NFT_META_SKUID:
163 case NFT_META_SKGID:
164#ifdef CONFIG_NET_CLS_ROUTE
165 case NFT_META_RTCLASSID:
166#endif
167#ifdef CONFIG_NETWORK_SECMARK
168 case NFT_META_SECMARK:
169#endif
170 break;
171 default:
172 return -EOPNOTSUPP;
173 }
174
175 priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG]));
176 err = nft_validate_output_register(priv->dreg);
177 if (err < 0)
178 return err;
179 return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
180}
181
182static int nft_meta_dump(struct sk_buff *skb, const struct nft_expr *expr)
183{
184 const struct nft_meta *priv = nft_expr_priv(expr);
185
186 if (nla_put_be32(skb, NFTA_META_DREG, htonl(priv->dreg)))
187 goto nla_put_failure;
188 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
189 goto nla_put_failure;
190 return 0;
191
192nla_put_failure:
193 return -1;
194}
195
196static struct nft_expr_type nft_meta_type;
197static const struct nft_expr_ops nft_meta_ops = {
198 .type = &nft_meta_type,
199 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
200 .eval = nft_meta_eval,
201 .init = nft_meta_init,
202 .dump = nft_meta_dump,
203};
204
205static struct nft_expr_type nft_meta_type __read_mostly = {
206 .name = "meta",
207 .ops = &nft_meta_ops,
208 .policy = nft_meta_policy,
209 .maxattr = NFTA_META_MAX,
210 .owner = THIS_MODULE,
211};
212
213static int __init nft_meta_module_init(void)
214{
215 return nft_register_expr(&nft_meta_type);
216}
217
218static void __exit nft_meta_module_exit(void)
219{
220 nft_unregister_expr(&nft_meta_type);
221}
222
223module_init(nft_meta_module_init);
224module_exit(nft_meta_module_exit);
225
226MODULE_LICENSE("GPL");
227MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
228MODULE_ALIAS_NFT_EXPR("meta");