//客户机有数据来就触发这里,其实就是跟上面的一样套路，只是反过来
private void OnClientData(IAsyncResult result)
{
if (IsStop)
{
return;
}
try
{
ProxyInfo pi = result.AsyncState as ProxyInfo;
SocketError error;
int size = pi.client.Client.EndReceive(result, out error);
if (size > 0)
{
//转发给远程真实服务器
NetworkStream stream = pi.proxy.GetStream();
stream.Write(pi.up_buf, 0, size);
//继续等待下一个数据包
pi.client.Client.BeginReceive(pi.up_buf, 0, pi.up_buf.Length, SocketFlags.None, this.OnClientData, pi);
}
}
catch
{
}
}
private async void OnConnect(object _client)
{
if (IsStop)
{
return;
}
TcpClient client = _client as TcpClient;
try
{
byte[] up_buf = new byte[BufferLen];
byte[] down_buf = new byte[BufferLen];
NetworkStream stream = client.GetStream();
//====================================================================
//连上的第一件事情就是先处理握手包，我刚意识到这不需要丢到循环里面啊
int num = await stream.ReadAsync(up_buf, 0, 2); //读2字节客户端发上来的东西，第一字节是协议，第二字节是下个包的长度
//Debug(up_buf, num, "1");
if (num != 2)
{
return;
}
int packlen = 0;
packlen = up_buf[1];
num = await stream.ReadAsync(up_buf, 0, packlen);
//Debug(up_buf, num, "2");
//回应握手包
down_buf[0] = 0x05;
down_buf[1] = 0x00;//回复说不需要认证
await stream.WriteAsync(down_buf, 0, 2);
stream.Flush();
//====================================================================
//====================================================================
//然后就是收目标请求信息并回复
//先收个4字节的包头
IPAddress ip = null;
num = stream.Read(up_buf, 0, 4);
//Debug(up_buf, num, "3");
if (num <= 0)
{
return;
}
//如果目标是个ip
if (up_buf[3] == 1 || up_buf[3] == 4)
{
//是个IPV6有16字节，ipv4是4字节
int iplen = (up_buf[3] == 1) ? 4 : 16;
byte[] iparr = new byte[iplen];
num = stream.Read(iparr, 0, iplen);
if (num <= 0)
{
stream.Close();
client.Close();
return;
}
ip = new IPAddress(iparr);
Output(client.Client.RemoteEndPoint.ToString() + "请求ip:" + ip.ToString());
}
//是个域名
else if (up_buf[3] == 3)
{
num = stream.Read(up_buf, 0, 1);
int urllen = up_buf[0];
num = stream.Read(up_buf, 0, urllen);
string url = Encoding.ASCII.GetString(up_buf);
//域名反查ip
IPAddress[] iplist = Dns.GetHostAddresses(url);
if (iplist.Length == 0)
{
stream.Close();
client.Close();
return;
}
ip = iplist[0];
Output(client.Client.RemoteEndPoint.ToString() + "请求域名:" + url);
}
//协议之外的就不知道是个什么鬼了
else
{
stream.Close();
client.Close();
return;
}
//收端口号
int port = 0;
num = stream.Read(up_buf, 0, 2);
byte[] portArr = { up_buf[1], up_buf[0] };//反转字节序
port = BitConverter.ToUInt16(portArr, 0);
Output("目标:" + ip.ToString() + ":" + port.ToString());
//回复客户端,完成握手
byte[] myip = ((IPEndPoint)this.Tcp.LocalEndpoint).Address.GetAddressBytes();
byte[] myport = BitConverter.GetBytes((ushort)this.Port);
down_buf[0] = 5;
down_buf[1] = 0;
down_buf[2] = 0;
down_buf[3] = 1;
myip.CopyTo(down_buf, 4);
myport.CopyTo(down_buf, 8);
await stream.WriteAsync(down_buf, 0, 10);
//====================================================================
//====================================================================
//握手完毕就是正常的收发数据包了
TcpClient proxy = new TcpClient();
proxy.Connect(ip, port);//连上真实目标（握手包里得到的ip和端口）
//用事件来做比较我之前写的while更科学点
//此处需要写个结构体放proxy和client，因为我希望同时传递proxy和client的socket对象，数据接收事件却只能传递一个参数
ProxyInfo pi = new ProxyInfo();
pi.proxy = proxy;
pi.client = client;
pi.up_buf = new byte[BufferLen];
pi.down_buf = new byte[BufferLen];
proxy.Client.BeginReceive(pi.down_buf, 0, pi.down_buf.Length, SocketFlags.None, this.OnProxyData, pi);
client.Client.BeginReceive(pi.up_buf, 0, pi.up_buf.Length, SocketFlags.None, this.OnClientData, pi);
}catch (Exception ex) {
Output(ex.ToString());
}
}
