From fd158d79d33d3c8b693e3e2d8c0e3068d529c2dc Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 29 Jul 2013 15:41:52 +0200 Subject: [PATCH] netfilter: tproxy: remove nf_tproxy_core, keep tw sk assigned to skb 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 d503b30bd648b3cb4e5f50b65d27e389960cc6d9 (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 Signed-off-by: Pablo Neira Ayuso --- Documentation/networking/tproxy.txt | 5 ++- include/net/netfilter/nf_tproxy_core.h | 4 --- net/netfilter/Kconfig | 22 +++--------- net/netfilter/Makefile | 3 -- net/netfilter/nf_tproxy_core.c | 62 ---------------------------------- net/netfilter/xt_TPROXY.c | 9 +++++ 6 files changed, 16 insertions(+), 89 deletions(-) delete mode 100644 net/netfilter/nf_tproxy_core.c diff --git a/Documentation/networking/tproxy.txt b/Documentation/networking/tproxy.txt index 7b5996d..ec11429 100644 --- a/Documentation/networking/tproxy.txt +++ b/Documentation/networking/tproxy.txt @@ -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 diff --git a/include/net/netfilter/nf_tproxy_core.h b/include/net/netfilter/nf_tproxy_core.h index 36d9379..975ffa4 100644 --- a/include/net/netfilter/nf_tproxy_core.h +++ b/include/net/netfilter/nf_tproxy_core.h @@ -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 diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 56d22ca..c45fc1a 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -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 diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index a1abf87..ebfa7dc 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -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 diff --git a/net/netfilter/nf_tproxy_core.c b/net/netfilter/nf_tproxy_core.c deleted file mode 100644 index 474d621..0000000 --- a/net/netfilter/nf_tproxy_core.c +++ /dev/null @@ -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 - -#include -#include -#include -#include -#include - - -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"); diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c index d7f1953..17c40de 100644 --- a/net/netfilter/xt_TPROXY.c +++ b/net/netfilter/xt_TPROXY.c @@ -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) -- 2.7.4