[tproxy] tproxy4, kernel 2.6.22 and squid-2.6.stable13

[Ming-Ching Tiew]

From: "KOVACS Krisztian" <hidden at sch.bme.hu>
> 
> Could you try if applying the attached patch on top of 4.0.3 helps you
> with SNAT? (The patch is completely untested but at the moment I can't do
> any testing.)
> 

I have got more conclusive testing results now after doing 
further isolation of the problem :-

1. The packet path for SNAT works now.

2. The packet path without SNAT has problem working together 
    with 'mangle' table OUTPUT chain ( maybe also with other chains
    in the mangle table as well). 

    It happens that I have iptables command which mark the packets 
    on the OUTPUT chain, then squid will fail to work. If I flush the 
    entire OUTPUT chain in the mangle table, then squid will work.

    However I am doing policy routing, I hope to use the fwmark
    to route the packets accordingly.

    I guess it is because tproxy is sharing the mark values with all  
    other packet mark and as soon as something else is making a mark, 
    it will mess up tproxy ? 

Regards