检查网络并重连 wan 口，检测多个 url

chk_net_redail.sh

#!/bin/sh
# filename: /root/chk_net_redail.sh
# 4=network error/refused/timeout/dns err/
# need "opkg install wget ca-bundle"

log()
{
    #echo $*
    logger -t redail $*
}

check_network(){
    ping -c 3 $1 1>/dev/null 2>/dev/null
    return $?
}

count=0
HOSTS='www.baidu.com www.163.com www.qq.com www.sogou.com 223.5.5.5 223.6.6.6 8.8.8.8 8.8.4.4 114.114.114.114'
for host in $HOSTS; do
    log will check $host
    if check_network $host; then
        break
    else
        count=$((count+1))
    fi
done

HOST_CNT=$(echo $HOSTS|wc -w)
if [ $count -ge $HOST_CNT ]; then
    log will redail
    ifdown wan; sleep 5; ifup wan
else
    log check network ok
fi