summaryrefslogtreecommitdiff
path: root/net/netfilter/xt_connmark.c
blob: aaa1b96691f942c43dd393945264917c661c49fd (plain)
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
/*
 *	xt_connmark - Netfilter module to match connection mark values
 *
 *	Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
 *	by Henrik Nordstrom <hno@marasystems.com>
 *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *	Jan Engelhardt <jengelh@computergmbh.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_connmark.h>

MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
MODULE_DESCRIPTION("Xtables: connection mark match");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_connmark");
MODULE_ALIAS("ip6t_connmark");

static bool
connmark_mt(const struct sk_buff *skb, const struct net_device *in,
            const struct net_device *out, const struct xt_match *match,
            const void *matchinfo, int offset, unsigned int protoff,
            bool *hotdrop)
{
	const struct xt_connmark_mtinfo1 *info = matchinfo;
	enum ip_conntrack_info ctinfo;
	const struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct == NULL)
		return false;

	return ((ct->mark & info->mask) == info->mark) ^ info->invert;
}

static bool
connmark_mt_v0(const struct sk_buff *skb, const struct net_device *in,
               const struct net_device *out, const struct xt_match *match,
               const void *matchinfo, int offset, unsigned int protoff,
               bool *hotdrop)
{
	const struct xt_connmark_info *info = matchinfo;
	const struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;

	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		return false;

	return ((ct->mark & info->mask) == info->mark) ^ info->invert;
}

static bool
connmark_mt_check_v0(const char *tablename, const void *ip,
                     const struct xt_match *match, void *matchinfo,
                     unsigned int hook_mask)
{
	const struct xt_connmark_info *cm = matchinfo;

	if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) {
		printk(KERN_WARNING "connmark: only support 32bit mark\n");
		return false;
	}
	if (nf_ct_l3proto_try_module_get(match->family) < 0) {
		printk(KERN_WARNING "can't load conntrack support for "
				    "proto=%u\n", match->family);
		return false;
	}
	return true;
}

static bool
connmark_mt_check(const char *tablename, const void *ip,
                  const struct xt_match *match, void *matchinfo,
                  unsigned int hook_mask)
{
	if (nf_ct_l3proto_try_module_get(match->family) < 0) {
		printk(KERN_WARNING "cannot load conntrack support for "
		       "proto=%u\n", match->family);
		return false;
	}
	return true;
}

static void
connmark_mt_destroy(const struct xt_match *match, void *matchinfo)
{
	nf_ct_l3proto_module_put(match->family);
}

#ifdef CONFIG_COMPAT
struct compat_xt_connmark_info {
	compat_ulong_t	mark, mask;
	u_int8_t	invert;
	u_int8_t	__pad1;
	u_int16_t	__pad2;
};

static void connmark_mt_compat_from_user_v0(void *dst, void *src)
{
	const struct compat_xt_connmark_info *cm = src;
	struct xt_connmark_info m = {
		.mark	= cm->mark,
		.mask	= cm->mask,
		.invert	= cm->invert,
	};
	memcpy(dst, &m, sizeof(m));
}

static int connmark_mt_compat_to_user_v0(void __user *dst, void *src)
{
	const struct xt_connmark_info *m = src;
	struct compat_xt_connmark_info cm = {
		.mark	= m->mark,
		.mask	= m->mask,
		.invert	= m->invert,
	};
	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
}
#endif /* CONFIG_COMPAT */

static struct xt_match connmark_mt_reg[] __read_mostly = {
	{
		.name		= "connmark",
		.revision	= 0,
		.family		= AF_INET,
		.checkentry	= connmark_mt_check_v0,
		.match		= connmark_mt_v0,
		.destroy	= connmark_mt_destroy,
		.matchsize	= sizeof(struct xt_connmark_info),
#ifdef CONFIG_COMPAT
		.compatsize	= sizeof(struct compat_xt_connmark_info),
		.compat_from_user = connmark_mt_compat_from_user_v0,
		.compat_to_user	= connmark_mt_compat_to_user_v0,
#endif
		.me		= THIS_MODULE
	},
	{
		.name		= "connmark",
		.revision	= 0,
		.family		= AF_INET6,
		.checkentry	= connmark_mt_check_v0,
		.match		= connmark_mt_v0,
		.destroy	= connmark_mt_destroy,
		.matchsize	= sizeof(struct xt_connmark_info),
#ifdef CONFIG_COMPAT
		.compatsize	= sizeof(struct compat_xt_connmark_info),
		.compat_from_user = connmark_mt_compat_from_user_v0,
		.compat_to_user	= connmark_mt_compat_to_user_v0,
#endif
		.me		= THIS_MODULE
	},
	{
		.name           = "connmark",
		.revision       = 1,
		.family         = AF_INET,
		.checkentry     = connmark_mt_check,
		.match          = connmark_mt,
		.matchsize      = sizeof(struct xt_connmark_mtinfo1),
		.destroy        = connmark_mt_destroy,
		.me             = THIS_MODULE,
	},
	{
		.name           = "connmark",
		.revision       = 1,
		.family         = AF_INET6,
		.checkentry     = connmark_mt_check,
		.match          = connmark_mt,
		.matchsize      = sizeof(struct xt_connmark_mtinfo1),
		.destroy        = connmark_mt_destroy,
		.me             = THIS_MODULE,
	},
};

static int __init connmark_mt_init(void)
{
	return xt_register_matches(connmark_mt_reg,
	       ARRAY_SIZE(connmark_mt_reg));
}

static void __exit connmark_mt_exit(void)
{
	xt_unregister_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg));
}

module_init(connmark_mt_init);
module_exit(connmark_mt_exit);