When forwarding traffic we receive an "unsupported request"

[whakru]

I have an openwrt router and transfer the client to linux ubuntu via iptables:

iptables -t mangle -A PREROUTING -j ACCEPT -p tcp -m multiport --dports 80,443 -s 192.168.31.123
iptables -t mangle -A PREROUTING -j MARK --set-mark 3 -p tcp -s 192.168.31.5 -m multiport --dports 80,443
ip rule add fwmark 3 table 2
ip route add default via 192.168.31.123 dev br-lan table 2

Next on Linux on which green-tunnel is installed:

sysctl -w net.ipv4.ip_forward=1
sysctl -w net.ipv4.conf.all.send_redirects=0
iptables -t nat -I PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080
iptables -t nat -I PREROUTING -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8080

green-tunnel started: gt --ip 192.168.31.123 --port 8080 --verbose 'green-tunnel:*'
Packets leave and arrive at the green-tunnel
but he writes errors:

  green-tunnel:proxy Error: Unsupported request:  +640ms
  green-tunnel:proxy Error: Unsupported request:  +3s
  green-tunnel:proxy Error: Unsupported request:  +4s

and so on endlessly, as a result there is no Internet.

What am I doing wrong? How can I forward one client to a proxy?