[PATCH] xt_socket: checks for the state of nf_conntrack

[PATCH] xt_socket: checks for the state of nf_conntrack

[Laszlo Attila Toth]

xt_socket can use connection tracking, and checks whether it is a module.

Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>
---
 net/netfilter/Kconfig |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 881203c..cb3ad74 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -837,6 +837,7 @@ config NETFILTER_XT_MATCH_SOCKET
 	depends on NETFILTER_TPROXY
 	depends on NETFILTER_XTABLES
 	depends on NETFILTER_ADVANCED
+	depends on !NF_CONNTRACK || NF_CONNTRACK
 	select NF_DEFRAG_IPV4
 	help
 	  This option adds a `socket' match, which can be used to match
-- 
1.6.2.2.404.ge96f3

Re: [PATCH] xt_socket: checks for the state of nf_conntrack

[David Miller]

From: Laszlo Attila Toth <panther@balabit.hu>
Date: Thu, 30 Apr 2009 17:35:55 +0200

> xt_socket can use connection tracking, and checks whether it is a module.
> 
> Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>

I don't understand why we want what this is doing....

> +	depends on !NF_CONNTRACK || NF_CONNTRACK

This means that if NF_CONNTRACK is modular, it won't allow
the xt_socket code to be built.

However, all of this stuff should be buildable modular.

Re: [PATCH] xt_socket: checks for the state of nf_conntrack

[Tóth László Attila]

Hi Dave,

On 2009.04.30., at 18:39, David Miller wrote:

> From: Laszlo Attila Toth <panther@balabit.hu>
> Date: Thu, 30 Apr 2009 17:35:55 +0200
>
>> xt_socket can use connection tracking, and checks whether it is a  
>> module.
>>
>> Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>
>
> I don't understand why we want what this is doing....
>

Most of the time the source / destination addresses and ports of the  
packet are enough to lookup the corresponding socket. With the SNAT  
target this kind of lookup is broken. The socket match is in the  
mangle table, before nat, thus it can see only the destination address  
set by the SNAT target (this is the reply direction). If we want to  
support SNAT, we need nf_conntrack.  But this is optional, if  
connection tracking is not in the kernel, the socket match will  
compiled without it....

>> +	depends on !NF_CONNTRACK || NF_CONNTRACK
>
> This means that if NF_CONNTRACK is modular, it won't allow
> the xt_socket code to be built.
>

I checked that if NF_\x10CONNTRACK is disabled, the socket match will be  
allowed to be built either into a module, or into vmlinuz. If  
NF_CONNTRACK is "y", it is exactly the same. If NF_CONNTRACK=m, the  
socket match can only be a module.

> However, all of this stuff should be buildable modular.

--
Attila

Re: [PATCH] xt_socket: checks for the state of nf_conntrack

[David Miller]

From: Laszlo Attila Toth <panther@balabit.hu>
Date: Thu, 30 Apr 2009 17:35:55 +0200

> xt_socket can use connection tracking, and checks whether it is a module.
> 
> Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>

Applied, thanks.