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/*
* xt_CONNMARK - Netfilter module to modify the 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 <linux/ip.h>
#include <net/checksum.h>
MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
MODULE_DESCRIPTION("Xtables: connection mark modification");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_CONNMARK");
MODULE_ALIAS("ip6t_CONNMARK");
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_CONNMARK.h>
#include <net/netfilter/nf_conntrack_ecache.h>
static unsigned int
connmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
const struct xt_connmark_tginfo1 *info = par->targinfo;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
u_int32_t newmark;
ct = nf_ct_get(skb, &ctinfo);
if (ct == NULL)
return XT_CONTINUE;
switch (info->mode) {
case XT_CONNMARK_SET:
newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
if (ct->mark != newmark) {
ct->mark = newmark;
nf_conntrack_event_cache(IPCT_MARK, ct);
}
break;
case XT_CONNMARK_SAVE:
newmark = (ct->mark & ~info->ctmask) ^
(skb->mark & info->nfmask);
if (ct->mark != newmark) {
ct->mark = newmark;
nf_conntrack_event_cache(IPCT_MARK, ct);
}
break;
case XT_CONNMARK_RESTORE:
newmark = (skb->mark & ~info->nfmask) ^
(ct->mark & info->ctmask);
skb->mark = newmark;
break;
}
return XT_CONTINUE;
}
static bool connmark_tg_check(const struct xt_tgchk_param *par)
{
if (nf_ct_l3proto_try_module_get(par->family) < 0) {
printk(KERN_WARNING "cannot load conntrack support for "
"proto=%u\n", par->family);
return false;
}
return true;
}
static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
{
nf_ct_l3proto_module_put(par->family);
}
static struct xt_target connmark_tg_reg __read_mostly = {
.name = "CONNMARK",
.revision = 1,
.family = NFPROTO_UNSPEC,
.checkentry = connmark_tg_check,
.target = connmark_tg,
.targetsize = sizeof(struct xt_connmark_tginfo1),
.destroy = connmark_tg_destroy,
.me = THIS_MODULE,
};
static int __init connmark_tg_init(void)
{
return xt_register_target(&connmark_tg_reg);
}
static void __exit connmark_tg_exit(void)
{
xt_unregister_target(&connmark_tg_reg);
}
module_init(connmark_tg_init);
module_exit(connmark_tg_exit);
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