WSAEnumNameSpaceProvidersA function (winsock2.h)
The WSAEnumNameSpaceProviders function retrieves information on available namespace providers.
Syntax
INT WSAAPI WSAEnumNameSpaceProvidersA(
[in, out] LPDWORD lpdwBufferLength,
[out] LPWSANAMESPACE_INFOA lpnspBuffer
);
Parameters
[in, out] lpdwBufferLength
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.
[out] lpnspBuffer
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.
Return value
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.
| Error code | Meaning |
|---|---|
| The lpnspBuffer parameter was a NULL pointer or the buffer length, lpdwBufferLength, was too small to receive all the relevant WSANAMESPACE_INFO structures and associated information. When this error is returned, the buffer length required is returned in the lpdwBufferLength parameter. | |
| The WS2_32.DLL has not been initialized. The application must first call WSAStartup before calling any Windows Sockets functions. | |
| There was insufficient memory to perform the operation. |
Remarks
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;
}
Windows Phone 8: The WSAEnumNameSpaceProvidersW function is supported for Windows Phone Store apps on Windows Phone 8 and later.
Windows 8.1 and Windows Server 2012 R2: The WSAEnumNameSpaceProvidersW function is supported for Windows Store apps on Windows 8.1, Windows Server 2012 R2, and later.
Note
The winsock2.h header defines WSAEnumNameSpaceProviders as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 8.1, Windows Vista [desktop apps | UWP apps] |
| Minimum supported server | Windows Server 2003 [desktop apps | UWP apps] |
| Target Platform | Windows |
| Header | winsock2.h |
| Library | Ws2_32.lib |
| DLL | Ws2_32.dll |