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CAsyncsocket bind function urgent plz

Posted on 2004-09-08
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Last Modified: 2013-11-20
Hi all,
I am developing a server application using the CAsynsocket class. I have used a windows32 console application and had managed to create a socket. But the problem is to bind it to the local port. I have a query whether its necessary to bind the server socket. My code is as follows

#include "stdafx.h"
#include <stdio.h>
#include <iostream>
#include <afxsock.h>
#include <winsock.h>


//using namespace std;
//TCHAR szError[100];


int main(int argc, char* argv[])

{
       // TODO: Place code here.

      int nRetCode =0 ;
      UINT nPort = 0;
      char* Socketaddr = "localhost";
//      SOCKADDR_IN sockaddr;
//      hostent *he;

//************************************************************************************//
      //test address structure

      
//      sockaddr.sin_addr. =


//*************************************************************************************//       
      //initialising MFC and print error on failure
      if(!AfxWinInit(::GetModuleHandle(NULL),NULL,::GetCommandLine(),0))
      {
            printf( _T("Fatal Error: MFC initialization failed"));//<< endl;
            return 1;
      }
//************************************************************************************//
      //Establish a connection to the server socket
      if(!AfxSocketInit())
      {
            AfxMessageBox("AfxSocketInit() Failed");
      }

      CAsyncSocket* pSocket = new CAsyncSocket;

      printf("Creating Socket Object\n");
      
//*************************************************************************************//

      //  creation
      int test = 0;
      test = pSocket->Create(nPort,SOCK_STREAM);
   
      if(test !=0)
      {
            printf("Succesfully Created Socket on %d\n",nPort,GetLastError());
      }
     
      else
      {
            printf("Cannot initialise socket\n",pSocket->GetLastError());
      }

//**************************************************************************************//


    //bind operation
      int bindtest = 0;


      bindtest =  pSocket->Bind(nPort,NULL);

      if(bindtest == 0)
      {

      printf("test value for bind printed %d",pSocket->GetLastError());

      }






   
//test line      printf("The value of create is ",test );

return 0;
}


The bind function always returns zero...hope some one could help me on this as i m stuck with this point
0
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Question by:Vignaesh
  • 4
4 Comments
 
LVL 19

Expert Comment

by:drichards
ID: 12007331
It is not legal to bind to port 0 (value of nPort at call to Bind).  Try another port.
0
 
LVL 19

Expert Comment

by:drichards
ID: 12007380
Also, why are you binding to a port after Create?  Create binds to a port.  If you pass 0 to create, Windows picks a port.  For client-side, this is usually correct.  The client usually does not have to use a specific port.
0
 
LVL 19

Accepted Solution

by:
drichards earned 500 total points
ID: 12007399
Here are a couple of lines from the Create docs:

"Parameters
nSocketPort
  A well-known port to be used with the socket, or 0 if you want Windows Sockets to select a port. "

"Create then calls Bind to bind the socket to the specified address. The following socket types are supported"
0
 
LVL 19

Expert Comment

by:drichards
ID: 12008462
It's the second comment that is the problem (socket already bound).  I looked at the implementation of Bind and it would select a port for you if you specify port 0 and TCP.
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