代理服务器，IE已经完全显示网页时又突然消失,不知道大家知道我说什么？

Question

我写了个转发器，在IE中设置代理地址为我的转发器地址，转发器把IE的请求数据转发给代理服务器，把代理服务器返回的数据转发给IE.
当在IE中打开www.yahoo.com，IE中已经完全显示网页时突然刷的一下又没了，显示“该页无法显示”。请问这是怎么回事？
我估计是要返回状态码之类的东西给IE,我不知道是什么

Answer 1

你的转发是要实现http proxy?
参看http 的rfc,如果是成功，你需要返回success http200 ok 字样，如果错误，返回http404，...

Answer 2

#include "stdafx.h"
#include "Proxy.h"
#include <winsock2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <afxmt.h>
//#include <afx.h>#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif/////////////////////////////////////////////////////////////////////////////
// The one and only application object#define PROXYPORT    5060    //Proxy Listen Port
#define BUFSIZE   10240      //Buffer size
CWinApp theApp;using namespace std;UINT ProxyToServer(LPVOID pParam);
UINT UserToProxyThread(void *pParam);struct SocketPair{
SOCKET  user_proxy;      //socket : local machine to proxy server
SOCKET  proxy_server;    //socket : proxy sever to remote server
BOOL    IsUser_ProxyClosed; // status of local machine to proxy server
BOOL    IsProxy_ServerClosed; // status of proxy server to remote server
HANDLE  User_SvrOK;    // status of setup connection between proxy server and remote server
CCriticalSection cs;
};SOCKET    gListen_Socket;   
//CRITICAL_SECTION csMemDebug2;VOID DebugPrint(LPCSTR lpFormat, ...) // 打印调试信息
{
static CStdioFile fDebugFile("log.txt", CFile::typeText | CFile::modeReadWrite | CFile::modeCreate);
va_list Marker;
char szBuf[10500];
CString szRecord;

va_start(Marker, lpFormat);
vsprintf(szBuf, lpFormat, Marker);
va_end(Marker);

szRecord.Format("%s\n", szBuf);
fDebugFile.WriteString((LPCSTR)szRecord);
fDebugFile.Flush();
}
int StartServer()
{
     WSADATA wsaData;
 sockaddr_in local;
 SOCKET listen_socket; if(::WSAStartup(0x202,&wsaData)!=0)
{printf("\nError in Startup session.\n");WSACleanup();return -1;}; local.sin_family=AF_INET;
local.sin_addr.s_addr=INADDR_ANY;
local.sin_port=htons(PROXYPORT); listen_socket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if(listen_socket==INVALID_SOCKET)
{printf("\nError in New a Socket.");WSACleanup();return -2;}
if(::bind(listen_socket,(sockaddr *)&local,sizeof(local))!=0)
{printf("\n Errorcode %d in Binding socket.",WSAGetLastError());WSACleanup();return -3; };
if(::listen(listen_socket,5)!=0)
{printf("\n Error in Listen."); WSACleanup(); return -4;}
gListen_Socket=listen_socket;  AfxBeginThread(UserToProxyThread,NULL);   //Start accept function
return 1;
}int CloseServer()
{
closesocket(gListen_Socket);
WSACleanup();
return 1;
}
// Setup chanel and read data from local , send data to remote
UINT UserToProxyThread(void *pParam)
{
 char Buffer[BUFSIZE];
//  char log[15000];
 int  Len;
 sockaddr_in from;
 SOCKET msg_socket;
 int fromlen,retval;
 SocketPair SPair;

 CWinThread *pChildThread;
     fromlen=sizeof(from);
 msg_socket=accept(gListen_Socket,(struct sockaddr*)&from,&fromlen);
   AfxBeginThread(UserToProxyThread,pParam); //Start another thread to listen.
 if( msg_socket==INVALID_SOCKET)
{ printf( "\nError  in accept "); return -5;}
 
//recieve the first line of client  SPair.IsUser_ProxyClosed=FALSE;
 SPair.IsProxy_ServerClosed=TRUE;
 SPair.user_proxy=msg_socket;  retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);
 
 if(retval==SOCKET_ERROR)
{ printf("Errorcode=%d Recv from client,ThreadID=%d",WSAGetLastError(),GetCurrentThreadId()); 
      if(SPair.IsUser_ProxyClosed==FALSE)
{closesocket(SPair.user_proxy);
 SPair.IsUser_ProxyClosed=TRUE;
}
}
 if(retval==0)
{printf("\nClient Close connection,ThreadID=%d",GetCurrentThreadId());
     if(SPair.IsUser_ProxyClosed==FALSE)
{closesocket(SPair.user_proxy);
 SPair.IsUser_ProxyClosed=TRUE;
}
}
 Len=retval;
#ifdef _DEBUG
if (Len==-1) Buffer[0]=0;
else Buffer[Len]=0;
SPair.cs.Lock();
 DebugPrint("\n Received %d bytes,data[\n%s\n]from client\n",retval,Buffer);
 SPair.cs.Unlock();
 
 
#endif
 //
 SPair.IsUser_ProxyClosed=FALSE;
 SPair.IsProxy_ServerClosed=TRUE;
 SPair.user_proxy=msg_socket;
 SPair.User_SvrOK=CreateEvent(NULL,TRUE,FALSE,NULL);  pChildThread=AfxBeginThread(ProxyToServer,(LPVOID)&SPair);
 ::WaitForSingleObject(SPair.User_SvrOK,60000);  //Wait for connection between proxy and remote server
 ::CloseHandle(SPair.User_SvrOK);  while(SPair.IsProxy_ServerClosed ==FALSE && SPair.IsUser_ProxyClosed==FALSE)
 {
   retval=send(SPair.proxy_server,Buffer,Len,0);
   if(retval==SOCKET_ERROR)
{ SPair.cs.Lock();
   DebugPrint("\nErrorcode=%d, Send to server,ThreadID=%d\n",WSAGetLastError(),GetCurrentThreadId());
     SPair.cs.Unlock();
 
 
     if(SPair.IsProxy_ServerClosed==FALSE)
{
closesocket(SPair.proxy_server);

SPair.IsProxy_ServerClosed=TRUE;

}
  continue;
}
    retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);
 
if(retval==SOCKET_ERROR)
{
SPair.cs.Lock();
DebugPrint("\nErrorcode=%d, Recv from client,ThreadID=%d\n",WSAGetLastError(),GetCurrentThreadId());
SPair.cs.Unlock();
      if(SPair.IsUser_ProxyClosed==FALSE)
{closesocket(SPair.user_proxy);
 SPair.IsUser_ProxyClosed=TRUE;
}
      continue;
}
if(retval==0)
{SPair.cs.Lock();
DebugPrint("\nClient Close connection,ThreadID=%d",GetCurrentThreadId());
 SPair.cs.Unlock();
     if(SPair.IsUser_ProxyClosed==FALSE)
{closesocket(SPair.user_proxy);
 SPair.IsUser_ProxyClosed=TRUE;
}
 break;
}
Len=retval;
#ifdef _DEBUG
if (Len==-1) Buffer[0]=0;
else Buffer[Len]=0;
SPair.cs.Lock();
 DebugPrint("\n Received %d bytes,data[\n%s\n]from client\n",retval,Buffer);
 SPair.cs.Unlock();
#endif

  } //End While     if(SPair.IsProxy_ServerClosed==FALSE)
{
closesocket(SPair.proxy_server);
SPair.IsProxy_ServerClosed=TRUE;
}
 if(SPair.IsUser_ProxyClosed==FALSE)
{closesocket(SPair.user_proxy);
 SPair.IsUser_ProxyClosed=TRUE;
}
::WaitForSingleObject(pChildThread->m_hThread,INFINITE);  //Should check the reture value
return 0;
}

Answer 3

// Read data from remote and send data to local
UINT ProxyToServer(LPVOID pParam)
{
    SocketPair * pPar=(SocketPair*)pParam;
char Buffer[BUFSIZE];
// char log[15000];
int retval,Len;
struct sockaddr_in server;
SOCKET  conn_socket; server.sin_family=AF_INET;
//代理服务器的地址和端口
server.sin_port=htons(80);
server.sin_addr.s_addr=inet_addr("202.113.49.22"); conn_socket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); /* Open a socket */
if (conn_socket <0 ) {
fprintf(stderr,"Client: Error Opening socket: Error %d\n",
WSAGetLastError());
pPar->IsProxy_ServerClosed=TRUE;
::SetEvent(pPar->User_SvrOK);
return -1;
}
if (connect(conn_socket,(struct sockaddr*)&server,sizeof(server))
== SOCKET_ERROR) {
fprintf(stderr,"connect() failed: %d\n",WSAGetLastError());
pPar->IsProxy_ServerClosed=TRUE;
::SetEvent(pPar->User_SvrOK);
return -1;
}
pPar->proxy_server=conn_socket;
pPar->IsProxy_ServerClosed=FALSE;
    ::SetEvent(pPar->User_SvrOK);
// cook up a string to send
while(!pPar->IsProxy_ServerClosed &&!pPar->IsUser_ProxyClosed)
{
retval = recv(conn_socket,Buffer,sizeof (Buffer),0 );
if (retval == SOCKET_ERROR ) {
pPar->cs.Lock();
 DebugPrint("\nErrorcode=%d, Recv from server,ThreadID=%d\n",WSAGetLastError(),GetCurrentThreadId());
 pPar->cs.Unlock();
//closesocket(conn_socket);
pPar->IsProxy_ServerClosed=TRUE;
break;
}
Len=retval;
if (retval == 0) {           //对方已关闭
pPar->cs.Lock();
DebugPrint("\nServer Close connection,ThreadID=%d",GetCurrentThreadId());
 pPar->cs.Unlock();
//closesocket(conn_socket);
pPar->IsProxy_ServerClosed=TRUE;
break;
} retval = send(pPar->user_proxy,Buffer,Len,0);
if (retval == SOCKET_ERROR) {
pPar->cs.Lock();
DebugPrint("\nErrorcode=%d, Send to client,ThreadID=%d\n",WSAGetLastError(),GetCurrentThreadId());
 pPar->cs.Unlock();
//closesocket(pPar->pPair->user_proxy);
pPar->IsUser_ProxyClosed=TRUE;
break;
}
#ifdef _DEBUG
if (Len==-1) Buffer[0]=0;
else Buffer[Len]=0;
pPar->cs.Lock();
DebugPrint("Received %d bytes, data [%s] from server\n",retval,Buffer);
 pPar->cs.Unlock();
#endif
}
if(pPar->IsProxy_ServerClosed==FALSE)
{
closesocket(pPar->proxy_server);
pPar->IsProxy_ServerClosed=TRUE;
}
 if(pPar->IsUser_ProxyClosed==FALSE)
{closesocket(pPar->user_proxy);
 pPar->IsUser_ProxyClosed=TRUE;
}
 return 1;
}int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
int nRetCode = 0; // initialize MFC and print and error on failure
if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
{
// TODO: change error code to suit your needs
cerr << _T("Fatal Error: MFC initialization failed") << endl;
nRetCode = 1;
}
else
{
// TODO: code your application's behavior here.
StartServer();
while(1)
if(getchar()=='q') break;
CloseServer();
} return nRetCode;
}