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/netfilter/nf_tables.h>
18#include <net/netfilter/nf_conntrack.h>
19#include <net/netfilter/nf_conntrack_tuple.h>
20#include <net/netfilter/nf_conntrack_helper.h>
21
22struct nft_ct {
23 enum nft_ct_keys key:8;
24 enum ip_conntrack_dir dir:8;
25 enum nft_registers dreg:8;
26 uint8_t family;
27};
28
29static void nft_ct_eval(const struct nft_expr *expr,
30 struct nft_data data[NFT_REG_MAX + 1],
31 const struct nft_pktinfo *pkt)
32{
33 const struct nft_ct *priv = nft_expr_priv(expr);
34 struct nft_data *dest = &data[priv->dreg];
35 enum ip_conntrack_info ctinfo;
36 const struct nf_conn *ct;
37 const struct nf_conn_help *help;
38 const struct nf_conntrack_tuple *tuple;
39 const struct nf_conntrack_helper *helper;
40 long diff;
41 unsigned int state;
42
43 ct = nf_ct_get(pkt->skb, &ctinfo);
44
45 switch (priv->key) {
46 case NFT_CT_STATE:
47 if (ct == NULL)
48 state = NF_CT_STATE_INVALID_BIT;
49 else if (nf_ct_is_untracked(ct))
50 state = NF_CT_STATE_UNTRACKED_BIT;
51 else
52 state = NF_CT_STATE_BIT(ctinfo);
53 dest->data[0] = state;
54 return;
55 }
56
57 if (ct == NULL)
58 goto err;
59
60 switch (priv->key) {
61 case NFT_CT_DIRECTION:
62 dest->data[0] = CTINFO2DIR(ctinfo);
63 return;
64 case NFT_CT_STATUS:
65 dest->data[0] = ct->status;
66 return;
67#ifdef CONFIG_NF_CONNTRACK_MARK
68 case NFT_CT_MARK:
69 dest->data[0] = ct->mark;
70 return;
71#endif
72#ifdef CONFIG_NF_CONNTRACK_SECMARK
73 case NFT_CT_SECMARK:
74 dest->data[0] = ct->secmark;
75 return;
76#endif
77 case NFT_CT_EXPIRATION:
78 diff = (long)jiffies - (long)ct->timeout.expires;
79 if (diff < 0)
80 diff = 0;
81 dest->data[0] = jiffies_to_msecs(diff);
82 return;
83 case NFT_CT_HELPER:
84 if (ct->master == NULL)
85 goto err;
86 help = nfct_help(ct->master);
87 if (help == NULL)
88 goto err;
89 helper = rcu_dereference(help->helper);
90 if (helper == NULL)
91 goto err;
92 if (strlen(helper->name) >= sizeof(dest->data))
93 goto err;
94 strncpy((char *)dest->data, helper->name, sizeof(dest->data));
95 return;
96 }
97
98 tuple = &ct->tuplehash[priv->dir].tuple;
99 switch (priv->key) {
100 case NFT_CT_L3PROTOCOL:
101 dest->data[0] = nf_ct_l3num(ct);
102 return;
103 case NFT_CT_SRC:
104 memcpy(dest->data, tuple->src.u3.all,
105 nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
106 return;
107 case NFT_CT_DST:
108 memcpy(dest->data, tuple->dst.u3.all,
109 nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
110 return;
111 case NFT_CT_PROTOCOL:
112 dest->data[0] = nf_ct_protonum(ct);
113 return;
114 case NFT_CT_PROTO_SRC:
115 dest->data[0] = (__force __u16)tuple->src.u.all;
116 return;
117 case NFT_CT_PROTO_DST:
118 dest->data[0] = (__force __u16)tuple->dst.u.all;
119 return;
120 }
121 return;
122err:
123 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
124}
125
126static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = {
127 [NFTA_CT_DREG] = { .type = NLA_U32 },
128 [NFTA_CT_KEY] = { .type = NLA_U32 },
129 [NFTA_CT_DIRECTION] = { .type = NLA_U8 },
130};
131
132static int nft_ct_init(const struct nft_ctx *ctx,
133 const struct nft_expr *expr,
134 const struct nlattr * const tb[])
135{
136 struct nft_ct *priv = nft_expr_priv(expr);
137 int err;
138
139 if (tb[NFTA_CT_DREG] == NULL ||
140 tb[NFTA_CT_KEY] == NULL)
141 return -EINVAL;
142
143 priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
144 if (tb[NFTA_CT_DIRECTION] != NULL) {
145 priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]);
146 switch (priv->dir) {
147 case IP_CT_DIR_ORIGINAL:
148 case IP_CT_DIR_REPLY:
149 break;
150 default:
151 return -EINVAL;
152 }
153 }
154
155 switch (priv->key) {
156 case NFT_CT_STATE:
157 case NFT_CT_DIRECTION:
158 case NFT_CT_STATUS:
159#ifdef CONFIG_NF_CONNTRACK_MARK
160 case NFT_CT_MARK:
161#endif
162#ifdef CONFIG_NF_CONNTRACK_SECMARK
163 case NFT_CT_SECMARK:
164#endif
165 case NFT_CT_EXPIRATION:
166 case NFT_CT_HELPER:
167 if (tb[NFTA_CT_DIRECTION] != NULL)
168 return -EINVAL;
169 break;
170 case NFT_CT_PROTOCOL:
171 case NFT_CT_SRC:
172 case NFT_CT_DST:
173 case NFT_CT_PROTO_SRC:
174 case NFT_CT_PROTO_DST:
175 if (tb[NFTA_CT_DIRECTION] == NULL)
176 return -EINVAL;
177 break;
178 default:
179 return -EOPNOTSUPP;
180 }
181
182 err = nf_ct_l3proto_try_module_get(ctx->afi->family);
183 if (err < 0)
184 return err;
185 priv->family = ctx->afi->family;
186
187 priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG]));
188 err = nft_validate_output_register(priv->dreg);
189 if (err < 0)
190 goto err1;
191
192 err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
193 if (err < 0)
194 goto err1;
195 return 0;
196
197err1:
198 nf_ct_l3proto_module_put(ctx->afi->family);
199 return err;
200}
201
202static void nft_ct_destroy(const struct nft_expr *expr)
203{
204 struct nft_ct *priv = nft_expr_priv(expr);
205
206 nf_ct_l3proto_module_put(priv->family);
207}
208
209static int nft_ct_dump(struct sk_buff *skb, const struct nft_expr *expr)
210{
211 const struct nft_ct *priv = nft_expr_priv(expr);
212
213 if (nla_put_be32(skb, NFTA_CT_DREG, htonl(priv->dreg)))
214 goto nla_put_failure;
215 if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key)))
216 goto nla_put_failure;
217 if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
218 goto nla_put_failure;
219 return 0;
220
221nla_put_failure:
222 return -1;
223}
224
225static struct nft_expr_type nft_ct_type;
226static const struct nft_expr_ops nft_ct_ops = {
227 .type = &nft_ct_type,
228 .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
229 .eval = nft_ct_eval,
230 .init = nft_ct_init,
231 .destroy = nft_ct_destroy,
232 .dump = nft_ct_dump,
233};
234
235static struct nft_expr_type nft_ct_type __read_mostly = {
236 .name = "ct",
237 .ops = &nft_ct_ops,
238 .policy = nft_ct_policy,
239 .maxattr = NFTA_CT_MAX,
240 .owner = THIS_MODULE,
241};
242
243static int __init nft_ct_module_init(void)
244{
245 return nft_register_expr(&nft_ct_type);
246}
247
248static void __exit nft_ct_module_exit(void)
249{
250 nft_unregister_expr(&nft_ct_type);
251}
252
253module_init(nft_ct_module_init);
254module_exit(nft_ct_module_exit);
255
256MODULE_LICENSE("GPL");
257MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
258MODULE_ALIAS_NFT_EXPR("ct");