Q311815: PRB: WSACleanUp() AV If Host Name Longer Than 54 Characters

Article: Q311815
Product(s): Microsoft Windows NT
Version(s): 4.0
Operating System(s): 
Keyword(s): kbAPI kbWinsock kbDSupport kbGrpDSNet
Last Modified: 10-DEC-2001

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Workstation version 4.0 
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SYMPTOMS
========

When you run gethostbyname(), gethostbyaddr(), or gethostname() on a Windows NT
4.0-based computer, the API returns the correct information. However, when you
call WSACleanUp(), an access violation occurs and the program fails.

NOTE: This problem does not occur on Windows 2000.

RESOLUTION
==========

To avoid this problem, do not use host names that contain more than 54
characters.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Right-click Network Neighborhood, and then click Properties.

2. Click the Protocol tab, and then select TCP/IP.

3. Click the Properties button.

4. Click the DNS tab. Change the host name to a name that has at least 54
  characters.

5. Run the following code:

  #include <Winsock2.h>
  #include <iostream.h>

  int main(int argc,char* argv[])
  {
  	WSADATA wsaData;
  	char pStr[512]={0};
  	int ret;
  	
  	if(WSAStartup(0x0101,&wsaData)) {
  		cout<<"WSAStartup ";
  		cout << " error: ?<<WSAGetLastError()<<endl;
  		return 0;
  	}
  	cout<<argv[1]<<endl;
  		
  	if(gethostname(pStr,512)) {
  		cout<<"gethostbyname ";
  		cout << " error: ?<<WSAGetLastError()<<endl;
  		WSACleanup();
  		return 0;
  	}
  	cout<<"host name: " <<pStr<<endl;
  	
  	ret=WSACleanup ();
  	if(ret) {
  		cout<<"WSACleanup ";
  		cout << " error: ?<<WSAGetLastError()<<endl;
  		return 0;
  	}
  	return 0;
  }

An access violation occurs when the call is made to WSACleanUp().

Additional query words:

======================================================================
Keywords          : kbAPI kbWinsock kbDSupport kbGrpDSNet 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400sp6 kbWinNTS400search kbWinNTS400 kbWinNTW400SP6a
Version           : :4.0
Issue type        : kbprb

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