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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 5 insertions, 17 deletions

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