Re: [libvirt-users] netfilter+libvirt=(smth got broken?)
Hi Nikolai,
On Wed, Mar 20, 2013 at 05:41:37PM +0400, Nikolai Zhubr wrote:
Hello,
20.03.2013 16:47, I wrote:
[...]
>This all looks to me as if "--ctdir" argument somehow magically changed
>its meaning to the opposite, but this just cannot be! I'm out of ideas
>and looking for insights. Any hints appreciated quite a lot.
Some more searching over maillists yielded this (quite astonishing):
net/netfilter/xt_conntrack.c
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 2c0086a..481a86f 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -195,7 +195,7 @@ conntrack_mt(const struct sk_buff *skb, struct
xt_action_param *par,
return info->match_flags & XT_CONNTRACK_STATE;
if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
(CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
- !!(info->invert_flags & XT_CONNTRACK_DIRECTION))
+ !(info->invert_flags & XT_CONNTRACK_DIRECTION))
return false;
if (info->match_flags & XT_CONNTRACK_ORIGSRC)
So apparently, netfilter's behaviour was indeed reversed at some
point, therefore libvirt stopped working properly.
--ctdir was broken and it was fixed in patch:
commit 96120d86fe302c006259baee9061eea9e1b9e486
Author: Florian Westphal <fw(a)strlen.de>
Date: Mon Apr 4 17:06:21 2011 +0200
netfilter: xt_conntrack: fix inverted conntrack direction test
--ctdir ORIGINAL matches REPLY packets, and vv:
userspace sets "invert_flags &= ~XT_CONNTRACK_DIRECTION" in ORIGINAL
case.
By looking at the changes you made:
--A FI-vnet0 -p tcp -m tcp --sport 110 -m conntrack --ctstate
ESTABLISHED -m conntrack --ctdir ORIGINAL -j RETURN
+-A FI-vnet0 -p tcp -m tcp --sport 110 -m conntrack --ctstate
ESTABLISHED -m conntrack --ctdir REPLY -j RETURN
The first rule looks wrong to me indeed, traffic coming in the
original direction will initiate the connection to destination port
TCP/110. Therefore, your change is correct.
It's unfortunate nobody noticed this rule was incorrect so far (even
if it was working).
I'd guess libvirt needs to be adapted then? Is it a known issue
or
should I fill in bugreport at Novell/Red Hat?
I think you should file the bug.