自动添加gfwlist域名的对应ip到路由表，实现动态自动翻墙

auto_vpn.sh

#!/bin/sh

while :
do
    dev=$(ip link | grep state | awk '{ sub(":", "", $2); print $2 }' | grep vpn)
    if [ $? -ne 0 ]; then
        sleep 5
        continue
    fi
    break
done

ip rule | grep "lookup vpn" || ip rule add table vpn
ip route add 8.8.8.8 dev pptp-vpn table vpn
ip route add 8.8.4.4 dev pptp-vpn table vpn

logread -f \
  | awk 'BEGIN {
    i=0;
    while (getline < "/root/gfwlist") {
      m = match($1, "^(\\|\\|)?[a-zA-Z0-9.]+$")
      if (m == 1) {
        if (match($1, "^\\|\\|") == 1) $1 = substr($1, 3);
        gfwlist[i++] = $1;
      }
    }
  }
  function gfw_match(domain) {
    for (i in gfwlist) {
      if (index(domain, gfwlist[i]) > 0)
        return 1;
    }
    return 0;
  }
  match($0, "dnsmasq\\[[0-9]+\\]: reply") {
     #Jan 15 15:13:01 OpenWrt daemon.info dnsmasq[20413]: reply js.users.51.la is 222.187.221.28
     domain_pos = match($0, ": reply [^ ]+ is");
     if (domain_pos != 0) {
       domain = substr($0, RSTART+8, RLENGTH-11);
       if (!gfw_match(domain)) {
         return;
       }
     }
     ip_pos = match($NF, "([0-9]+\.?){4}");
     if (ip_pos != 0) {
       ip = $NF;
       if (!(ip in added)) {
         added[ip] = 1;
         print "ip route add "ip" dev pptp-vpn table vpn"
         print domain, ip >> "/tmp/auto_vpn.log"
       }
     }
   }' | sh -x