netdev - Re: PROBLEM: TPROXY and DNAT broken (bisected to 079096f103fa)

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Date:	Mon, 15 Aug 2016 16:28:22 +0000
From:	Brandon Cazander <brandon.cazander@...tapplied.net>
To:	Florian Westphal <fw@...len.de>
CC:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	Eric Dumazet <eric.dumazet@...il.com>
Subject: Re: PROBLEM: TPROXY and DNAT broken (bisected to 079096f103fa)

I can recreate the issue with these rules:

ip rule add fwmark 1 lookup 100
ip route add local 0.0.0.0/0 dev lo table 100
iptables -t mangle -A PREROUTING -p tcp -m tcp --dport 8080 -j TPROXY --on-port 9876 --on-ip 0.0.0.0 --tproxy-mark 0x1/0x1
iptables -t nat -A PREROUTING -d 192.168.7.20/32 -i eth0 -j DNAT --to-destination 192.168.8.1

If I add in the DIVERT chain it works:

iptables -t mangle -N DIVERT
iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
iptables -t mangle -A DIVERT -j MARK --set-mark 1
iptables -t mangle -A DIVERT -j ACCEPT
iptables -t mangle -A PREROUTING -p tcp -m tcp --dport 8080 -j TPROXY --on-port 9876 --on-ip 0.0.0.0 --tproxy-mark 0x1/0x1

But that's still a regression in my opinion.