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netfilter: xtables: move ipt_ecn to xt_ecn

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Prepare the ECN match for augmentation by an IPv6 counterpart. Since
no symbol dependencies to ipv6.ko are added, having a single ecn match
module is the more so welcome.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Jan Engelhardt
2011-06-09 21:03:07 +02:00
committed by Pablo Neira Ayuso
parent c0d2b8376a
commit d446a8202c
8 changed files with 53 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv4/netfilter/Kconfig
View File

@@ -76,11 +76,11 @@ config IP_NF_MATCH_AH
config IP_NF_MATCH_ECN
tristate '"ecn" match support'
depends on NETFILTER_ADVANCED
help
This option adds a `ECN' match, which allows you to match against
the IPv4 and TCP header ECN fields.
To compile it as a module, choose M here. If unsure, say N.
select NETFILTER_XT_MATCH_ECN
---help---
This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_MATCH_ECN.
config IP_NF_MATCH_RPFILTER
tristate '"rpfilter" reverse path filter match support'

1
net/ipv4/netfilter/Makefile
View File

@@ -49,7 +49,6 @@ obj-$(CONFIG_IP_NF_SECURITY) += iptable_security.o
# matches
obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o
obj-$(CONFIG_IP_NF_MATCH_ECN) += ipt_ecn.o
obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o
# targets

127
net/ipv4/netfilter/ipt_ecn.c
View File

@@ -1,127 +0,0 @@
/* IP tables module for matching the value of the IPv4 and TCP ECN bits
*
* (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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_ecn.h>
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match for IPv4");
MODULE_LICENSE("GPL");
static inline bool match_ip(const struct sk_buff *skb,
const struct ipt_ecn_info *einfo)
{
return ((ip_hdr(skb)->tos & IPT_ECN_IP_MASK) == einfo->ip_ect) ^
!!(einfo->invert & IPT_ECN_OP_MATCH_IP);
}
static inline bool match_tcp(const struct sk_buff *skb,
const struct ipt_ecn_info *einfo,
bool *hotdrop)
{
struct tcphdr _tcph;
const struct tcphdr *th;
/* In practice, TCP match does this, so can't fail. But let's
* be good citizens.
*/
th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
if (th == NULL) {
*hotdrop = false;
return false;
}
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
if (th->ece == 1)
return false;
} else {
if (th->ece == 0)
return false;
}
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
if (th->cwr == 1)
return false;
} else {
if (th->cwr == 0)
return false;
}
}
return true;
}
static bool ecn_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct ipt_ecn_info *info = par->matchinfo;
if (info->operation & IPT_ECN_OP_MATCH_IP)
if (!match_ip(skb, info))
return false;
if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
if (!match_tcp(skb, info, &par->hotdrop))
return false;
}
return true;
}
static int ecn_mt_check(const struct xt_mtchk_param *par)
{
const struct ipt_ecn_info *info = par->matchinfo;
const struct ipt_ip *ip = par->entryinfo;
if (info->operation & IPT_ECN_OP_MATCH_MASK)
return -EINVAL;
if (info->invert & IPT_ECN_OP_MATCH_MASK)
return -EINVAL;
if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) &&
(ip->proto != IPPROTO_TCP || ip->invflags & IPT_INV_PROTO)) {
pr_info("cannot match TCP bits in rule for non-tcp packets\n");
return -EINVAL;
}
return 0;
}
static struct xt_match ecn_mt_reg __read_mostly = {
.name = "ecn",
.family = NFPROTO_IPV4,
.match = ecn_mt,
.matchsize = sizeof(struct ipt_ecn_info),
.checkentry = ecn_mt_check,
.me = THIS_MODULE,
};
static int __init ecn_mt_init(void)
{
return xt_register_match(&ecn_mt_reg);
}
static void __exit ecn_mt_exit(void)
{
xt_unregister_match(&ecn_mt_reg);
}
module_init(ecn_mt_init);
module_exit(ecn_mt_exit);