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netfilter: tproxy: remove nf_tproxy_core, keep tw sk assigned to skb

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The module was "permanent", due to the special tproxy skb->destructor.
Nowadays we have tcp early demux and its sock_edemux destructor in
networking core which can be used instead.

Thanks to early demux changes the input path now also handles
"skb->sk is tw socket" correctly, so this no longer needs the special
handling introduced with commit d503b30bd6
(netfilter: tproxy: do not assign timewait sockets to skb->sk).

Thus:
- move assign_sock function to where its needed
- don't prevent timewait sockets from being assigned to the skb
- remove nf_tproxy_core.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2013-07-29 15:41:52 +02:00 committed by Pablo Neira Ayuso
parent 957bec3685
commit fd158d79d3
6 changed files with 16 additions and 89 deletions
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5
Documentation/networking/tproxy.txt
View File

@ -2,9 +2,8 @@ Transparent proxy support
=========================
This feature adds Linux 2.2-like transparent proxy support to current kernels.
To use it, enable NETFILTER_TPROXY, the socket match and the TPROXY target in
your kernel config. You will need policy routing too, so be sure to enable that
as well.
To use it, enable the socket match and the TPROXY target in your kernel config.
You will need policy routing too, so be sure to enable that as well.
1. Making non-local sockets work

4
include/net/netfilter/nf_tproxy_core.h
View File

@ -203,8 +203,4 @@ nf_tproxy_get_sock_v6(struct net *net, const u8 protocol,
}
#endif
/* assign a socket to the skb -- consumes sk */
void
nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk);
#endif

22
net/netfilter/Kconfig
View File

@ -410,20 +410,6 @@ config NF_NAT_TFTP
endif # NF_CONNTRACK
# transparent proxy support
config NETFILTER_TPROXY
tristate "Transparent proxying support"
depends on IP_NF_MANGLE
depends on NETFILTER_ADVANCED
help
This option enables transparent proxying support, that is,
support for handling non-locally bound IPv4 TCP and UDP sockets.
For it to work you will have to configure certain iptables rules
and use policy routing. For more information on how to set it up
see Documentation/networking/tproxy.txt.
To compile it as a module, choose M here. If unsure, say N.
config NETFILTER_XTABLES
tristate "Netfilter Xtables support (required for ip_tables)"
default m if NETFILTER_ADVANCED=n
@ -720,10 +706,10 @@ config NETFILTER_XT_TARGET_TEE
this clone be rerouted to another nexthop.
config NETFILTER_XT_TARGET_TPROXY
tristate '"TPROXY" target support'
depends on NETFILTER_TPROXY
tristate '"TPROXY" target transparent proxying support'
depends on NETFILTER_XTABLES
depends on NETFILTER_ADVANCED
depends on IP_NF_MANGLE
select NF_DEFRAG_IPV4
select NF_DEFRAG_IPV6 if IP6_NF_IPTABLES
help
@ -731,6 +717,9 @@ config NETFILTER_XT_TARGET_TPROXY
REDIRECT. It can only be used in the mangle table and is useful
to redirect traffic to a transparent proxy. It does _not_ depend
on Netfilter connection tracking and NAT, unlike REDIRECT.
For it to work you will have to configure certain iptables rules
and use policy routing. For more information on how to set it up
see Documentation/networking/tproxy.txt.
To compile it as a module, choose M here. If unsure, say N.
@ -1180,7 +1169,6 @@ config NETFILTER_XT_MATCH_SCTP
config NETFILTER_XT_MATCH_SOCKET
tristate '"socket" match support'
depends on NETFILTER_TPROXY
depends on NETFILTER_XTABLES
depends on NETFILTER_ADVANCED
depends on !NF_CONNTRACK || NF_CONNTRACK

3
net/netfilter/Makefile
View File

@ -61,9 +61,6 @@ obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o
# transparent proxy support
obj-$(CONFIG_NETFILTER_TPROXY) += nf_tproxy_core.o
# generic X tables
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o

62
net/netfilter/nf_tproxy_core.c
View File

@ -1,62 +0,0 @@
/*
* Transparent proxy support for Linux/iptables
*
* Copyright (c) 2006-2007 BalaBit IT Ltd.
* Author: Balazs Scheidler, Krisztian Kovacs
*
* 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/net.h>
#include <linux/if.h>
#include <linux/netdevice.h>
#include <net/udp.h>
#include <net/netfilter/nf_tproxy_core.h>
static void
nf_tproxy_destructor(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
skb->sk = NULL;
skb->destructor = NULL;
if (sk)
sock_put(sk);
}
/* consumes sk */
void
nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
{
/* assigning tw sockets complicates things; most
* skb->sk->X checks would have to test sk->sk_state first */
if (sk->sk_state == TCP_TIME_WAIT) {
inet_twsk_put(inet_twsk(sk));
return;
}
skb_orphan(skb);
skb->sk = sk;
skb->destructor = nf_tproxy_destructor;
}
EXPORT_SYMBOL_GPL(nf_tproxy_assign_sock);
static int __init nf_tproxy_init(void)
{
pr_info("NF_TPROXY: Transparent proxy support initialized, version 4.1.0\n");
pr_info("NF_TPROXY: Copyright (c) 2006-2007 BalaBit IT Ltd.\n");
return 0;
}
module_init(nf_tproxy_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Krisztian Kovacs");
MODULE_DESCRIPTION("Transparent proxy support core routines");

9
net/netfilter/xt_TPROXY.c
View File

@ -117,6 +117,15 @@ tproxy_handle_time_wait4(struct sk_buff *skb, __be32 laddr, __be16 lport,
return sk;
}
/* assign a socket to the skb -- consumes sk */
static void
nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
{
skb_orphan(skb);
skb->sk = sk;
skb->destructor = sock_edemux;
}
static unsigned int
tproxy_tg4(struct sk_buff *skb, __be32 laddr, __be16 lport,
u_int32_t mark_mask, u_int32_t mark_value)