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/* This kernel module matches connection mark values set by the
* CONNMARK target
*
* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
* by Henrik Nordstrom <hno@marasystems.com>
*
* 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("IP tables connmark match module");
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_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(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 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(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(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",
.family = AF_INET,
.checkentry = connmark_mt_check,
.match = connmark_mt,
.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,
.compat_to_user = connmark_mt_compat_to_user,
#endif
.me = THIS_MODULE
},
{
.name = "connmark",
.family = AF_INET6,
.checkentry = connmark_mt_check,
.match = connmark_mt,
.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,
.compat_to_user = connmark_mt_compat_to_user,
#endif
.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);
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