![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
Now the skb->nh union has just one member, .raw, i.e. it is just like the skb->mac union, strange, no? I'm just leaving it like that till the transport layer is done with, when we'll rename skb->mac.raw to skb->mac_header (or ->mac_header_offset?), ditto for ->{h,nh}. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/* Kernel module to match packet length. */
|
|
/* (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/ipv6.h>
|
|
#include <net/ip.h>
|
|
|
|
#include <linux/netfilter/xt_length.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
|
|
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
|
|
MODULE_DESCRIPTION("IP tables packet length matching module");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("ipt_length");
|
|
MODULE_ALIAS("ip6t_length");
|
|
|
|
static int
|
|
match(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,
|
|
int *hotdrop)
|
|
{
|
|
const struct xt_length_info *info = matchinfo;
|
|
u_int16_t pktlen = ntohs(ip_hdr(skb)->tot_len);
|
|
|
|
return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
|
|
}
|
|
|
|
static int
|
|
match6(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,
|
|
int *hotdrop)
|
|
{
|
|
const struct xt_length_info *info = matchinfo;
|
|
const u_int16_t pktlen = (ntohs(ipv6_hdr(skb)->payload_len) +
|
|
sizeof(struct ipv6hdr));
|
|
|
|
return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
|
|
}
|
|
|
|
static struct xt_match xt_length_match[] = {
|
|
{
|
|
.name = "length",
|
|
.family = AF_INET,
|
|
.match = match,
|
|
.matchsize = sizeof(struct xt_length_info),
|
|
.me = THIS_MODULE,
|
|
},
|
|
{
|
|
.name = "length",
|
|
.family = AF_INET6,
|
|
.match = match6,
|
|
.matchsize = sizeof(struct xt_length_info),
|
|
.me = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init xt_length_init(void)
|
|
{
|
|
return xt_register_matches(xt_length_match,
|
|
ARRAY_SIZE(xt_length_match));
|
|
}
|
|
|
|
static void __exit xt_length_fini(void)
|
|
{
|
|
xt_unregister_matches(xt_length_match, ARRAY_SIZE(xt_length_match));
|
|
}
|
|
|
|
module_init(xt_length_init);
|
|
module_exit(xt_length_fini);
|