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From: Philip Craig <philipc@snapgear.com>
To: Frank Bulk <frnkblk@iname.com>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: conntrack ftp fails to handle PORT (and PASV?) command when split over multiple TCP packets
Date: Tue, 18 Nov 2008 10:30:01 +1000	[thread overview]
Message-ID: <49220C89.4040801@snapgear.com> (raw)
In-Reply-To: <!&!AAAAAAAAAAAuAAAAAAAAAKTyXRN5/+lGvU59a+P7CFMBAN6gY+ZG84BMpVQcAbDh1IQAAAATbSgAABAAAACjGmKcXUZtSrl15MejBLj+AQAAAAA=@iname.com>

Frank Bulk wrote:
> Can anyone confirm that iptables still behaves this way, and if so, code a
> fix so that no matter how many packets a PORT or PASV command are split over
> (in other words, no matter how small the client's MTU) that iptables ACKs
> each packet received on the LAN side and the ALG properly reassembles the
> command and sends it out the WAN interface?

iptables is a packet filter, not an ALG.  You could add more state to the
helper, but it would be hard to get right, and I don't think it is worth
the effort.  Try using a userspace ftp proxy instead.  (eg I've used frox
with no problems.)


  parent reply	other threads:[~2008-11-18  0:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-15 21:13 conntrack ftp fails to handle PORT (and PASV?) command when split over multiple TCP packets Frank Bulk
2008-11-17 11:08 ` Jozsef Kadlecsik
2008-11-18  0:30 ` Philip Craig [this message]
2008-11-18  2:36   ` Frank Bulk
2008-11-18  3:32     ` Philip Craig

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