2005-04-16 22:20:36 +00:00
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/* iptables module to match on related connections */
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/*
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* (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* 19 Mar 2002 Harald Welte <laforge@gnumonks.org>:
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* - Port to newnat infrastructure
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter.h>
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2006-01-06 21:15:11 +00:00
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#include <linux/interrupt.h>
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[NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-10 00:38:16 +00:00
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#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
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2005-04-16 22:20:36 +00:00
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#include <linux/netfilter_ipv4/ip_conntrack.h>
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#include <linux/netfilter_ipv4/ip_conntrack_core.h>
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#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
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[NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-10 00:38:16 +00:00
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#else
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#endif
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2005-04-16 22:20:36 +00:00
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv4/ipt_helper.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>");
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MODULE_DESCRIPTION("iptables helper match module");
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(format, args...)
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#endif
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[NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-10 00:38:16 +00:00
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#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
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2005-04-16 22:20:36 +00:00
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop)
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{
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const struct ipt_helper_info *info = matchinfo;
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struct ip_conntrack *ct;
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enum ip_conntrack_info ctinfo;
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int ret = info->invert;
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ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
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if (!ct) {
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DEBUGP("ipt_helper: Eek! invalid conntrack?\n");
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return ret;
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}
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if (!ct->master) {
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DEBUGP("ipt_helper: conntrack %p has no master\n", ct);
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return ret;
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}
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2005-06-21 21:01:30 +00:00
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read_lock_bh(&ip_conntrack_lock);
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2005-04-16 22:20:36 +00:00
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if (!ct->master->helper) {
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DEBUGP("ipt_helper: master ct %p has no helper\n",
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exp->expectant);
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goto out_unlock;
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}
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DEBUGP("master's name = %s , info->name = %s\n",
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ct->master->helper->name, info->name);
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if (info->name[0] == '\0')
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ret ^= 1;
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else
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ret ^= !strncmp(ct->master->helper->name, info->name,
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strlen(ct->master->helper->name));
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out_unlock:
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2005-06-21 21:01:30 +00:00
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read_unlock_bh(&ip_conntrack_lock);
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2005-04-16 22:20:36 +00:00
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return ret;
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}
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[NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-10 00:38:16 +00:00
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#else /* CONFIG_IP_NF_CONNTRACK */
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop)
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{
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const struct ipt_helper_info *info = matchinfo;
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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int ret = info->invert;
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ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
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if (!ct) {
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DEBUGP("ipt_helper: Eek! invalid conntrack?\n");
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return ret;
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}
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if (!ct->master) {
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DEBUGP("ipt_helper: conntrack %p has no master\n", ct);
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return ret;
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}
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read_lock_bh(&nf_conntrack_lock);
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if (!ct->master->helper) {
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DEBUGP("ipt_helper: master ct %p has no helper\n",
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exp->expectant);
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goto out_unlock;
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}
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DEBUGP("master's name = %s , info->name = %s\n",
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ct->master->helper->name, info->name);
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if (info->name[0] == '\0')
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ret ^= 1;
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else
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ret ^= !strncmp(ct->master->helper->name, info->name,
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strlen(ct->master->helper->name));
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out_unlock:
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read_unlock_bh(&nf_conntrack_lock);
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return ret;
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}
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#endif
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2005-04-16 22:20:36 +00:00
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static int check(const char *tablename,
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const struct ipt_ip *ip,
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void *matchinfo,
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unsigned int matchsize,
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unsigned int hook_mask)
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{
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struct ipt_helper_info *info = matchinfo;
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info->name[29] = '\0';
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/* verify size */
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if (matchsize != IPT_ALIGN(sizeof(struct ipt_helper_info)))
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return 0;
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return 1;
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}
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static struct ipt_match helper_match = {
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.name = "helper",
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.match = &match,
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.checkentry = &check,
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.me = THIS_MODULE,
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};
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static int __init init(void)
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{
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need_ip_conntrack();
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return ipt_register_match(&helper_match);
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}
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static void __exit fini(void)
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{
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ipt_unregister_match(&helper_match);
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}
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module_init(init);
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module_exit(fini);
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