#!/bin/sh
if ping -c 4 9.9.9.9;
then
  echo "4G seems good"
else
  echo -ne "AT^NDISDUP=1,0\r\n" > /dev/ttyUSB0
  sleep 1
  echo -ne "AT^NDISDUP=1,1,\"sl2sfr\"\r\n" > /dev/ttyUSB0
  sleep 1
  udhcpc -i wwan0
  iptables -t nat -A POSTROUTING -o wwan0 -j MASQUERADE
  iptables -A FORWARD -i br0 -j ACCEPT
  iptables -t mangle -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
fi