![Andrew Morton](/assets/img/avatar_default.png)
Every netfilter module uses `init' for its module_init() function and `fini' or `cleanup' for its module_exit() function. Problem is, this creates uninformative initcall_debug output and makes ctags rather useless. So go through and rename them all to $(filename)_init and $(filename)_fini. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
133 lines
3 KiB
C
133 lines
3 KiB
C
/* IP tables module for matching the value of the IPv4 and TCP ECN bits
|
|
*
|
|
* ipt_ecn.c,v 1.3 2002/05/29 15:09:00 laforge Exp
|
|
*
|
|
* (C) 2002 by Harald Welte <laforge@gnumonks.org>
|
|
*
|
|
* 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/tcp.h>
|
|
|
|
#include <linux/netfilter_ipv4/ip_tables.h>
|
|
#include <linux/netfilter_ipv4/ipt_ecn.h>
|
|
|
|
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
|
|
MODULE_DESCRIPTION("iptables ECN matching module");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static inline int match_ip(const struct sk_buff *skb,
|
|
const struct ipt_ecn_info *einfo)
|
|
{
|
|
return ((skb->nh.iph->tos&IPT_ECN_IP_MASK) == einfo->ip_ect);
|
|
}
|
|
|
|
static inline int match_tcp(const struct sk_buff *skb,
|
|
const struct ipt_ecn_info *einfo,
|
|
int *hotdrop)
|
|
{
|
|
struct tcphdr _tcph, *th;
|
|
|
|
/* In practice, TCP match does this, so can't fail. But let's
|
|
* be good citizens.
|
|
*/
|
|
th = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
|
|
sizeof(_tcph), &_tcph);
|
|
if (th == NULL) {
|
|
*hotdrop = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
|
|
if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
|
|
if (th->ece == 1)
|
|
return 0;
|
|
} else {
|
|
if (th->ece == 0)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
|
|
if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
|
|
if (th->cwr == 1)
|
|
return 0;
|
|
} else {
|
|
if (th->cwr == 0)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
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 ipt_ecn_info *info = matchinfo;
|
|
|
|
if (info->operation & IPT_ECN_OP_MATCH_IP)
|
|
if (!match_ip(skb, info))
|
|
return 0;
|
|
|
|
if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
|
|
if (skb->nh.iph->protocol != IPPROTO_TCP)
|
|
return 0;
|
|
if (!match_tcp(skb, info, hotdrop))
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int checkentry(const char *tablename, const void *ip_void,
|
|
const struct xt_match *match,
|
|
void *matchinfo, unsigned int matchsize,
|
|
unsigned int hook_mask)
|
|
{
|
|
const struct ipt_ecn_info *info = matchinfo;
|
|
const struct ipt_ip *ip = ip_void;
|
|
|
|
if (info->operation & IPT_ECN_OP_MATCH_MASK)
|
|
return 0;
|
|
|
|
if (info->invert & IPT_ECN_OP_MATCH_MASK)
|
|
return 0;
|
|
|
|
if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)
|
|
&& ip->proto != IPPROTO_TCP) {
|
|
printk(KERN_WARNING "ipt_ecn: can't match TCP bits in rule for"
|
|
" non-tcp packets\n");
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct ipt_match ecn_match = {
|
|
.name = "ecn",
|
|
.match = match,
|
|
.matchsize = sizeof(struct ipt_ecn_info),
|
|
.checkentry = checkentry,
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init ipt_ecn_init(void)
|
|
{
|
|
return ipt_register_match(&ecn_match);
|
|
}
|
|
|
|
static void __exit ipt_ecn_fini(void)
|
|
{
|
|
ipt_unregister_match(&ecn_match);
|
|
}
|
|
|
|
module_init(ipt_ecn_init);
|
|
module_exit(ipt_ecn_fini);
|