WSAEnumNameSpaceProviders Function

The WSAEnumNameSpaceProviders function retrieves information on available namespace providers.

Syntax

INT WSAAPI WSAEnumNameSpaceProviders(
  __inout  LPDWORD lpdwBufferLength,
  __out    LPWSANAMESPACE_INFO lpnspBuffer
);

Parameter

• lpdwBufferLength [in, out]
  On input, the number of bytes contained in the buffer pointed to by lpnspBuffer. On output (if the function fails, and the error is WSAEFAULT), the minimum number of bytes to pass for the lpnspBuffer to retrieve all the requested information. The buffer passed to WSAEnumNameSpaceProviders must be sufficient to hold all of the namespace information.

• lpnspBuffer [out]
  A buffer that is filled with WSANAMESPACE_INFO structures. The returned structures are located consecutively at the head of the buffer. Variable sized information referenced by pointers in the structures point to locations within the buffer located between the end of the fixed sized structures and the end of the buffer. The number of structures filled in is the return value of WSAEnumNameSpaceProviders.

Rückgabewert

The WSAEnumNameSpaceProviders function returns the number of WSANAMESPACE_INFO structures copied into lpnspBuffer. Otherwise, the value SOCKET_ERROR is returned, and a specific error number can be retrieved by calling WSAGetLastError.

Hinweise

The WSAEnumNameSpaceProviders function returns information on available namespace providers in the buffer pointed to by the lpnspBuffer parameter. The returned buffer contains an array of WSANAMESPACE_INFO structures located consecutively at the head of the buffer. Variable sized information referenced by pointers in the WSANAMESPACE_INFO structures point to locations within the buffer located between the end of the fixed WSANAMESPACE_INFO structures and the end of the buffer. The number of WSANAMESPACE_INFO structures filled in is returned by the WSAEnumNameSpaceProviders function.

Each WSANAMESPACE_INFO structure entry contains the provider-specific information on the namespace entry passed to the WSCInstallNameSpace and WSCInstallNameSpace32 functions when the namespace provider was installed.

The WSAEnumNameSpaceProvidersEx function is an enhanced version of the WSAEnumNameSpaceProviders function. The WSCEnumNameSpaceProvidersEx32 function is an enhanced version of the WSAEnumNameSpaceProviders function that returns information on available 32-bit namespace providers for use on 64-bit platforms.

Example Code

The following example demonstrates the use of the WSAEnumNameSpaceProviders function to retrieve information on available namespace providers.

#ifndef UNICODE
#define UNICODE 1
#endif

#include <winsock2.h>
#include <ws2tcpip.h>
#include <objbase.h>
#include <stdio.h>

// Link with ws2_32.lib and ole32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "ole32.lib")

#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
// Note: could also use malloc() and free()

int wmain()
{

    //-----------------------------------------
    // Declare and initialize variables
    WSADATA wsaData;
    int iResult;
    int iError = 0;

    INT iNuminfo = 0;

    int i;
    

    // Allocate a 4K buffer to retrieve all the namespace providers
    DWORD dwInitialBufferLen = 4096;
    DWORD dwBufferLen;
    LPWSANAMESPACE_INFO lpProviderInfo;
    
    
    // variables needed for converting provider GUID to a string
    int iRet = 0;
    WCHAR GuidString[40] = {0};

    // Set dwBufferLen to the initial buffer length
    dwBufferLen = dwInitialBufferLen;
    
    // Initialize Winsock
    iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        wprintf(L"WSAStartup failed: %d\n", iResult);
        return 1;
    }
    
    lpProviderInfo = (LPWSANAMESPACE_INFO) MALLOC(dwBufferLen);
    if (lpProviderInfo == NULL) {
        wprintf(L"Memory allocation for providers buffer failed\n");
        WSACleanup();
        return 1;
    }
    
    iNuminfo = WSAEnumNameSpaceProviders(&dwBufferLen, lpProviderInfo);
    if (iNuminfo == SOCKET_ERROR) {
        iError = WSAGetLastError();
        if (iError == WSAEFAULT && dwBufferLen != dwInitialBufferLen) {
            wprintf(L"WSAEnumNameSpaceProviders failed with too small a buffer\n");
            wprintf(L"  Increasing the buffer to %u\n\n", dwBufferLen);
            if (lpProviderInfo) {
               FREE(lpProviderInfo);
               lpProviderInfo = NULL;
            }        

            lpProviderInfo = (LPWSANAMESPACE_INFO) MALLOC(dwBufferLen);
            if (lpProviderInfo == NULL) {
                wprintf(L"Memory allocation for providers buffer failed\n");
                WSACleanup();
               return 1;
            }

            iNuminfo = WSAEnumNameSpaceProviders(&dwBufferLen, lpProviderInfo);
            if (iNuminfo == SOCKET_ERROR) {
               wprintf(L"WSAEnumNameSpaceProviders failed with error: %d\n",
                  WSAGetLastError() );
               if (lpProviderInfo) {
                  FREE(lpProviderInfo);
                  lpProviderInfo = NULL;
               }        
               WSACleanup();
               return 1;
            }
            else
                wprintf(L"\n");   
        } 
        else {   
            wprintf(L"WSAEnumNameSpaceProviders failed with error: %d\n",
               WSAGetLastError() );
            if (lpProviderInfo) {
               FREE(lpProviderInfo);
               lpProviderInfo = NULL;
            }        
           WSACleanup();
           return 1;
        } 
     }

       wprintf(L"WSAEnumNameSpaceProviders succeeded with provider data count = %d\n\n",
           iNuminfo);
       for (i= 0; i < iNuminfo; i++) {
            iRet = StringFromGUID2(lpProviderInfo[i].NSProviderId, (LPOLESTR) &GuidString, 39); 
            if (iRet == 0)
                wprintf(L"StringFromGUID2 failed\n");
            else 
                wprintf(L"NameSpace ProviderId[%u] = %ws\n",i, GuidString);

           wprintf(L"NameSpace[%u] = ", i);
           switch (lpProviderInfo[i].dwNameSpace) {
           case NS_DNS:
               wprintf(L"Domain Name System (NS_DNS)\n");
               break;
           case NS_WINS:
               wprintf(L"Windows Internet Naming Service (NS_WINS)\n");
               break;
           case NS_NETBT:
               wprintf(L"NetBIOS (NS_NETBT)\n");
               break;
           case NS_NTDS:
               wprintf(L"Windows NT Directory Services (NS_NTDS)\n");
               break;
           case NS_NLA:
               wprintf(L"Network Location Awareness (NS_NLA)\n");
               break;
           // following values only defined on Vista and later
#if(_WIN32_WINNT >= 0x0600)
           case NS_BTH:
               wprintf(L"Bluetooth (NS_BTH)\n");
               break;
           case NS_EMAIL:
               wprintf(L"Email (NS_EMAIL)\n");
               break;
           case NS_PNRPNAME:
               wprintf(L"Peer-to-peer (NS_PNRPNAME)\n");
               break;
           case NS_PNRPCLOUD:
               wprintf(L"Peer-to-peer collection (NS_PNRPCLOUD)\n");
               break;
#endif
           default:
               wprintf(L"Other value (%u)\n", lpProviderInfo[i].dwNameSpace);             
               break;
           }    

           if (lpProviderInfo[i].fActive)
               wprintf(L"Namespace[%u] is active\n", i);
           else    
               wprintf(L"Namespace[%u] is inactive\n", i);

           wprintf(L"NameSpace Version[%u] = %u\n", i, lpProviderInfo[i].dwVersion);

           wprintf(L"Namespace Identifier[%u] = %ws\n\n", i, lpProviderInfo[i].lpszIdentifier);
       }           

    if (lpProviderInfo) {
        FREE(lpProviderInfo);
        lpProviderInfo = NULL;
    }        
    WSACleanup();
    
    return 0;
}

Anforderungen

Siehe auch

Winsock Reference

Winsock Functions

WSANAMESPACE_INFO

WSAEnumNameSpaceProvidersEx

WSCEnumNameSpaceProvidersEx32

WSAGetLastError

WSAStartup

WSCInstallNameSpace

WSCInstallNameSpaceEx