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/*
* "IPMARK" target extension for Xtables
* Copyright © Grzegorz Janoszka <Grzegorz.Janoszka@pro.onet.pl>, 2003
* Jan Engelhardt, 2008
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License; either
* version 2 of the License, or any later version, as published by the
* Free Software Foundation.
*/
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/version.h>
#include <linux/netfilter/x_tables.h>
#include <net/checksum.h>
#include "xt_IPMARK.h"
#include "compat_xtables.h"
MODULE_AUTHOR("Grzegorz Janoszka <Grzegorz@Janoszka.pl>");
MODULE_DESCRIPTION("Xtables: mark based on IP address");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_IPMARK");
MODULE_ALIAS("ip6t_IPMARK");
static unsigned int
ipmark_tg4(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_ipmark_tginfo *ipmarkinfo = par->targinfo;
const struct iphdr *iph = ip_hdr(skb);
__u32 mark;
if (ipmarkinfo->selector == XT_IPMARK_SRC)
mark = ntohl(iph->saddr);
else
mark = ntohl(iph->daddr);
mark >>= ipmarkinfo->shift;
mark &= ipmarkinfo->andmask;
mark |= ipmarkinfo->ormask;
skb_nfmark(skb) = mark;
return XT_CONTINUE;
}
/* Function is safe for any value of @s */
static __u32 ipmark_from_ip6(const struct in6_addr *a, unsigned int s)
{
unsigned int q = s % 32;
__u32 mask;
if (s >= 128)
return 0;
mask = ntohl(a->s6_addr32[3 - s/32]) >> q;
if (s > 0 && s < 96 && q != 0)
mask |= ntohl(a->s6_addr32[2 - s/32]) << (32 - q);
return mask;
}
static unsigned int
ipmark_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_ipmark_tginfo *info = par->targinfo;
const struct ipv6hdr *iph = ipv6_hdr(skb);
__u32 mark;
if (info->selector == XT_IPMARK_SRC)
mark = ipmark_from_ip6(&iph->saddr, info->shift);
else
mark = ipmark_from_ip6(&iph->daddr, info->shift);
mark &= info->andmask;
mark |= info->ormask;
skb_nfmark(skb) = mark;
return XT_CONTINUE;
}
static struct xt_target ipmark_tg_reg[] __read_mostly = {
{
.name = "IPMARK",
.revision = 1,
.family = NFPROTO_IPV4,
.table = "mangle",
.target = ipmark_tg4,
.targetsize = sizeof(struct xt_ipmark_tginfo),
.me = THIS_MODULE,
},
{
.name = "IPMARK",
.revision = 1,
.family = NFPROTO_IPV6,
.table = "mangle",
.target = ipmark_tg6,
.targetsize = sizeof(struct xt_ipmark_tginfo),
.me = THIS_MODULE,
},
};
static int __init ipmark_tg_init(void)
{
return xt_register_targets(ipmark_tg_reg, ARRAY_SIZE(ipmark_tg_reg));
}
static void __exit ipmark_tg_exit(void)
{
xt_unregister_targets(ipmark_tg_reg, ARRAY_SIZE(ipmark_tg_reg));
}
module_init(ipmark_tg_init);
module_exit(ipmark_tg_exit);
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