openwrt 获取 wan 口 IP（公网IP）
ifconfig -a | grep inet | grep -v inet6 | grep -v 127.0.0.1 | grep -v 192.168.100.1 | grep -v 192.168.223.1 | grep -v 172.17.0.1 | awk '{print $2}' | tr -d "addr:"
ifconfig -a | grep inet | grep -v inet6 | grep -v 127.0.0.1 | grep -v 192.168.100.1 | grep -v 192.168.223.1 | grep -v 172.17.0.1 | awk '{print $2}' | tr -d "addr:"
