static List<Tuple<IPEndPoint, List<IPEndPoint>>> GetConfig()
{
    var result = new List<Tuple<IPEndPoint, List<IPEndPoint>>>();
    var lines = File.ReadAllLines("forward.txt");       //从配置文件中读取所有行
    foreach (var line in lines)
    {
        string[] fields = line.Split('|');  //按|进行切割
        if (fields.Length < 2) continue;    //过滤空行
        IPEndPoint main = new IPEndPoint(IPAddress.Any, int.Parse(fields[0]));  //提取监听端口
        List<IPEndPoint> forwordingList = new List<IPEndPoint>();
        for (int i = 1; i < fields.Length; i++)     //提取转发列表
        {
            int index = fields[i].IndexOf(":");
            if (index != -1)
            {
                forwordingList.Add(new IPEndPoint(IPAddress.Parse(fields[i].Substring(0, index)), int.Parse(fields[i].Substring(index+1))));
            }
        }
        if (forwordingList.Count > 0)   //过滤掉空列表
        {
            result.Add(new Tuple<IPEndPoint, List<IPEndPoint>>(main, forwordingList));
        }
    }
    return result;
}

static List<Tuple<IPEndPoint, List<IPEndPoint>>> GetConfig1()
{
    var result = new List<Tuple<IPEndPoint, List<IPEndPoint>>>();
    Regex r = new Regex(@"^(\d+)(\|.+:\d+)+");
    Regex r2 = new Regex(@"\G\|([\d\.]+):(\d+)");
    var lines = File.ReadAllLines("forward.txt");

    foreach (var line in lines)
    {
        if (r.IsMatch(line))
        {
            var match = r.Match(line);
            IPEndPoint main = new IPEndPoint(IPAddress.Any, int.Parse(match.Groups[1].Value));
            List<IPEndPoint> forwordingList = new List<IPEndPoint>();
            foreach (Match match2 in r2.Matches(match.Groups[2].Value))
            {
                forwordingList.Add(new IPEndPoint(IPAddress.Parse(match2.Groups[1].Value), int.Parse(match2.Groups[2].Value)));
            }
            result.Add(new Tuple<IPEndPoint, List<IPEndPoint>>(main, forwordingList));
        }
    }
    return result;
}

static List<Tuple<IPEndPoint, List<IPEndPoint>>> GetConfig2()
{
    Regex r = new Regex(@"^(\d+)(\|.+:\d+)+");
    Regex r2 = new Regex(@"\G\|([\d\.]+):(\d+)");

    return File.ReadAllLines("forward.txt").ToList()
        .Where( i => r.IsMatch(i))
        .Select( i=> r.Match(i))
        .Select( i=> new  Tuple<IPEndPoint, List<IPEndPoint>>(
            new IPEndPoint(IPAddress.Any, int.Parse(i.Groups[1].Value)),
            (from Match j in r2.Matches(i.Groups[2].Value) select new IPEndPoint(IPAddress.Parse(j.Groups[1].Value), int.Parse(j.Groups[2].Value))).ToList()
            )           
        ).ToList();
}

server = new TcpListener(listen);
server.Start(1);
client = server.AcceptTcpClient();
server.Stop();      //停止监听, 同一时间只接收一个连接
server = null;
listenStream = client.GetStream();
listenStream.ReadTimeout = READ_TIMEOUT;
while (true)
{
    int len = listenStream.Read(buffer, 0, BUFF_SIZE);
    if (len > 0)
    {
        byte[] tmp = new byte[len];
        Array.Copy(buffer, tmp, len);
        Forwarding(tmp);  //转发数据
    }
    else
    {
        //.. 处理连接中断
    }
}

client = new TcpClient();
var result = client.BeginConnect(currentEndPoint.Address, currentEndPoint.Port, null, null);
var success = result.AsyncWaitHandle.WaitOne(TimeSpan.FromMilliseconds(CONNECT_TIMEOUT));
if (!success)   //超时处理
{
    Console.WriteLine("connect {0} timeout", currentEndPoint);
    continue;
}
client.EndConnect(result);
forwardingStream = client.GetStream();
forwardingStream.ReadTimeout = READ_TIMEOUT;
while (true)
{
    int len = forwardingStream.Read(buffer, 0, BUFF_SIZE);
    if (len > 0)
    {
        byte[] tmp = new byte[len];
        Array.Copy(buffer, tmp, len);
        Response(tmp);
    }
    else
    {
        //.. 处理连接中断
    }
}