67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
/* Length Match - IPv6 Port */
|
|
|
|
/* (C) 1999-2001 James Morris <jmorros@intercode.com.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/netfilter_ipv6/ip6t_length.h>
|
|
#include <linux/netfilter_ipv6/ip6_tables.h>
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
|
|
MODULE_DESCRIPTION("IPv6 packet length match");
|
|
|
|
static int
|
|
match(const struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
const void *matchinfo,
|
|
int offset,
|
|
unsigned int protoff,
|
|
int *hotdrop)
|
|
{
|
|
const struct ip6t_length_info *info = matchinfo;
|
|
u_int16_t pktlen = ntohs(skb->nh.ipv6h->payload_len) + sizeof(struct ipv6hdr);
|
|
|
|
return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
|
|
}
|
|
|
|
static int
|
|
checkentry(const char *tablename,
|
|
const struct ip6t_ip6 *ip,
|
|
void *matchinfo,
|
|
unsigned int matchsize,
|
|
unsigned int hook_mask)
|
|
{
|
|
if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_length_info)))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct ip6t_match length_match = {
|
|
.name = "length",
|
|
.match = &match,
|
|
.checkentry = &checkentry,
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init init(void)
|
|
{
|
|
return ip6t_register_match(&length_match);
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
ip6t_unregister_match(&length_match);
|
|
}
|
|
|
|
module_init(init);
|
|
module_exit(fini);
|