blob: 69f78e96fdb44a5c293a92e53a98559b1ddf2209 [file] [log] [blame]
/*
* xt_connmark - Netfilter module to operate on connection marks
*
* 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@medozas.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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_ecache.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 operations");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_CONNMARK");
MODULE_ALIAS("ip6t_CONNMARK");
MODULE_ALIAS("ipt_connmark");
MODULE_ALIAS("ip6t_connmark");
static unsigned int
connmark_tg(struct sk_buff *skb, const struct xt_action_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 int connmark_tg_check(const struct xt_tgchk_param *par)
{
int ret;
ret = nf_ct_l3proto_try_module_get(par->family);
if (ret < 0)
pr_info("cannot load conntrack support for proto=%u\n",
par->family);
return ret;
}
static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
{
nf_ct_l3proto_module_put(par->family);
}
static bool
connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_connmark_mtinfo1 *info = par->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 int connmark_mt_check(const struct xt_mtchk_param *par)
{
int ret;
ret = nf_ct_l3proto_try_module_get(par->family);
if (ret < 0)
pr_info("cannot load conntrack support for proto=%u\n",
par->family);
return ret;
}
static void connmark_mt_destroy(const struct xt_mtdtor_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 struct xt_match connmark_mt_reg __read_mostly = {
.name = "connmark",
.revision = 1,
.family = NFPROTO_UNSPEC,
.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)
{
int ret;
ret = xt_register_target(&connmark_tg_reg);
if (ret < 0)
return ret;
ret = xt_register_match(&connmark_mt_reg);
if (ret < 0) {
xt_unregister_target(&connmark_tg_reg);
return ret;
}
return 0;
}
static void __exit connmark_mt_exit(void)
{
xt_unregister_match(&connmark_mt_reg);
xt_unregister_target(&connmark_tg_reg);
}
module_init(connmark_mt_init);
module_exit(connmark_mt_exit);