粗糙的C#版HTTP代理.docx

1、粗糙的C#版HTTP代理粗糙的C#版HTTP代理 2008-8-5 0:38:21 粗糙的C#版HTTP代理说说这段代码的问题吧。首先是字符串切割的问题，要将客户端提交过来的GET，POST等原始请求切割，分离出主机名，端口，URL等数据。这里用正则匹配是最好的，遗憾的是我不擅长此道，所以使用了手动切割的办法，很笨重繁琐，但是毕竟它工作得很好。第二个问题是Keep-Alive的问题，这里我没有处理好。最开始我在http proxy里面修改客户端请求，强行将keep-alive修改为close，但是发现在某些站点的时候会出错。于是使用了类似select的方法读取数据，直到超时关闭两端的连接。我猜

2、测，这里如果解析content-length会更好，但是略微繁琐了点，还是等我仔细阅读下RFC再看怎么修改吧。第三个是CONNECT方法的问题，这个到很简单，转发数据就行了，因此是这个代码中写得最好的一部分，用来登陆QQ还是不错的。 说实话，我不喜欢HTTP这种太宽松的协议，感觉灵活得让我难以把握。直接看代码吧，我加了很多debug信息，真的要用就去掉好了。调用这个类很简单，看main函数的实现就好了。为了方便贴代码，我写的时候就把三个类写到一个文件里面去了。顺便要说的是，虽然有类，但是没有任何面向对象的东西这也再次证明，其实我算不上一个程序员，最多是个代码爱好者。 using System;

3、 using System.Net; using System.Net.Sockets; using System.Text; using System.IO; using System.Threading; using System.Collections; namespace HttpProxy public class HttpProxy int ProxyPort; / / 代理服务器入口类构造函数 / / Http Proxy监听的端口 public HttpProxy( int Port) ProxyPort = Port; / / 启动Http代理服务器 / public voi

4、d Start( ) TcpListener tcplistener = null; try / 开始监听端口 tcplistener = new TcpListener(Dns.GetHostAddresses(Dns.GetHostName()0, ProxyPort); tcplistener.Start(); Console.WriteLine(侦听端口号: + ProxyPort.ToString(); catch (Exception e) Console.WriteLine(启动代理服务器失败: + e.Message); while (true) try / 接受客户端连接 S

5、ocket socket = tcplistener.AcceptSocket(); HttpSession Session = new HttpSession(socket); / 启动新线程，处理连接 Thread thread = new Thread(new ThreadStart(Session.Start); thread.Start(); catch( Exception e ) Console.WriteLine(接受客户端连接异常: + e.Message ); public class HttpSession / 客户端socket Socket ClientSocket;

6、 / 设定编码 Encoding ASCII = Encoding.ASCII; / / 构造函数 / / 客户端socket public HttpSession(Socket socket) this.ClientSocket = socket; public void Start() / 客户端缓冲区，读取客户端命令 Byte ReadBuff = new byte1024 * 10; try int Length = ClientSocket.Receive(ReadBuff); / 没有读到数据 if (0 = Length) Console.WriteLine(从客户端读取命令错误

7、); ClientSocket.Shutdown(SocketShutdown.Both); ClientSocket.Close(); return; / 读取出现异常 catch (Exception e) Console.WriteLine(读取客户端异常: + e.Message); / 来自客户端的HTTP请求字符串 string ClientMsg = ASCII.GetString(ReadBuff); / 根据rnrn截取请求行 string Line = ClientMsg.Substring(0, ClientMsg.IndexOf(rn); string CmdArray

8、 = Line.Split( ); / GET:80/index.php HTTP/1 / CONNECT :443 HTTP/1 string Cmd = CmdArray0; string RawUrl = CmdArray1; Console.WriteLine(原始请求: , Line); / CONNECT请求 if (Cmd = CONNECT) DoConnect(RawUrl); / GET,POST和其他 else DoOther(RawUrl, ClientMsg); / / 处理CONNECT命令，此处作用是支持QQ，MSN，以及多级代理串联等 / / private v

9、oid DoConnect( string RawUrl ) string Args = RawUrl.Split( : ); string Host = Args0; int Port = int.Parse(Args1); Socket ServerSocket = null; try IPAddress IpList = Dns.GetHostEntry(Host).AddressList; Console.WriteLine(尝试连接:, IpList0, Port); ServerSocket = new Socket(AddressFamily.InterNetwork, Sock

10、etType.Stream, ProtocolType.Tcp); ServerSocket.Connect(IpList0, Port); catch (Exception e) Console.WriteLine(连接真实服务器异常: + e.Message); / 连接真实服务器成功 if (ServerSocket.Connected) ClientSocket.Send( ASCII.GetBytes(HTTP/0 200 Connection establishedrnrn) ); else ClientSocket.Shutdown(SocketShutdown.Both); C

11、lientSocket.Close(); / 开始转发数据 ForwardTcpData(ClientSocket, ServerSocket); / / 处理GET，POST等命令。使用了POLL，在代理服务器中强制去掉了Keep-Alive能力 / / / public void DoOther(string RawUrl, string ClientMsg) RawUrl = RawUrl.Substring(0 + http:/.Length); int Port; string Host; string Url; / 下面是分割处理请求，此处应该用正则匹配，不过我不擅长，因此手动切割

12、，_! int index1 = RawUrl.IndexOf(:); / 没有端口 if (index1 = -1) Port = 80; int index2 = RawUrl.IndexOf(/); / 没有目录 if (index2 = -1) Host = RawUrl; Url = /; else Host = RawUrl.Substring(0, index2); Url = RawUrl.Substring(index2); else int index2 = RawUrl.IndexOf(/); / 没有目录 if (index2 = -1) Host = RawUrl.S

13、ubstring(0, index1); Port = IntParse(RawUrl.Substring(index1 + 1); Url = /; else / /出现在:之前，则说明:后面的不是端口 if (index2 index1) Host = RawUrl.Substring(0, index2); Port = 80; else Host = RawUrl.Substring(0, index1); Port = IntParse(RawUrl.Substring(index1 + 1, index2 - index1 - 1); Url = RawUrl.Substring(

14、index2); Console.WriteLine(Host is:, Port is:, Url is:, Host, Port, Url); IPAddress address = null; try IPHostEntry IPHost = Dns.GetHostEntry(Host); address = IPHost.AddressList; Console.WriteLine(Web服务器IP地址: + address0); catch( Exception e ) Console.WriteLine( 解析服务器地址异常: + e.Message ); Socket IPsoc

15、ket = null; try / 连接到真实WEB服务器 IPEndPoint ipEndpoint = new IPEndPoint(address0, Port); IPsocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); IPsocket.Connect(ipEndpoint); / 对WEB服务器端传送HTTP请求命令，将原始HTTP请求中HTTP PROXY部分包装去掉 string ReqData = ClientMsg; / 改写头中的URL, ReqData

16、= ReqData.Replace(http:/+RawUrl, Url); / 按照rn切分HTTP头 string ReqArray = ReqData.Split(new string1rn, StringSplitOptions.None); ReqData = ; / 改写Keep-Alive等字段 for (int index = 0; index ReqArray.Length; index+) /* if (ReqArrayindex.StartsWith(Accept-Encoding:) ReqArrayindex = Accept-Encoding: deflate; *

17、/ if (ReqArrayindex.StartsWith(Proxy-Connection:) ReqArrayindex = ReqArrayindex.Replace(Proxy-Connection:, Connection:); /ReqArrayindex = Connection: close; /* else if (ReqArrayindex.StartsWith(Keep-Alive:) ReqArrayindex = ; */ / 修改后的字段组合成请求 if( ReqArrayindex != ) ReqData = ReqData + ReqArrayindex +

18、 rn; ReqData = ReqData.Trim(); byte SendBuff = ASCII.GetBytes(ReqData); IPsocket.Send(SendBuff); catch( Exception e ) Console.WriteLine( 发送请求到服务器异常: + e.Message ); / 使用Poll来判断完成，某些站点会出问题 while (true) Byte RecvBuff = new byte1024 * 20; try if( !IPsocket.Poll( 15 * 1000 * 1000, SelectMode.SelectRead )

19、 ) Console.WriteLine(HTTP超时，关闭连接); break; catch (Exception e) Console.WriteLine(Poll: + e.Message); break; int Length = 0; try Length = IPsocket.Receive(RecvBuff); if (0 = Length) Console.WriteLine(服务端关闭); break; Console.WriteLine(从服务端收到字节, Length); catch (Exception e) Console.WriteLine(Recv: + e.Me

20、ssage); break; try Length = ClientSocket.Send(RecvBuff, Length, 0); Console.WriteLine(发送字节到客户端, Length); catch (Exception e) Console.WriteLine(Send: + e.Message); /* / 根据接收字节数来判断完成，某些站点会出问题 try while (true) Byte RecvBuff = new byte1024 * 10; int Length = IPsocket.Receive(RecvBuff); if (Length = 0) C

21、onsole.WriteLine(从服务端接收数据完成); break; Console.WriteLine(从服务端收到字节, Length); Length = ClientSocket.Send(RecvBuff, Length, 0); Console.WriteLine(发送字节到客户端, Length); catch (Exception e) Console.WriteLine(e.Message); */ try ClientSocket.Shutdown(SocketShutdown.Both); ClientSocket.Close(); IPsocket.Shutdown

22、(SocketShutdown.Both); IPsocket.Close(); catch (Exception e) /Console.WriteLine(e.Message); / / 在客户端和服务器之间中转数据 / / 客户端socket / 服务端socket private void ForwardTcpData(Socket client, Socket server) ArrayList ReadList = new ArrayList(2); while (true) ReadList.Clear(); ReadList.Add(client); ReadList.Add(

23、server); try Socket.Select(ReadList, null, null, 1 * 1000 * 1000); catch (SocketException e) Console.WriteLine(Select error: + e.Message); break; / 超时 if (ReadList.Count = 0) /Console.WriteLine(Time out); continue; / 客户端可读 if (ReadList.Contains(client) byte Recv = new byte1024 * 10; int Length = 0;

24、try Length = client.Receive(Recv, Recv.Length, 0); if (Length = 0) Console.WriteLine(Client is disconnect.); break; Console.WriteLine( Recv bytes from client, Length); catch (Exception e) Console.WriteLine(Read from client error: + e.Message); break; try Length = server.Send(Recv, Length, 0); Console.WriteLine( Write bytes to ser