Unregistering a Peer Name

Artykuł
01/07/2021

When you unregister a peer name, a registered name is removed from a Peer Name Resolution Protocol (PNRP) cloud.

Unregistering a Peer Name

To unregister a peer name, call WSASetService. The essOperation parameter must have a value of RNRSERVICE_DELETE. Use the guidelines in the following sections of this topic to make the required configurations to the WSASetService parameters and the WSAQUERYSET structure.

Configuring WSASetService

When an application calls WSASetService, the parameters must be configured according to the following specifications:

essOperation must have a value of RNRSERVICE_DELETE.
dwFlags must be zero (0).
lpqsRegInfo must point to a WSAQUERYSET structure, which must be configured by using the guidelines in the following section of this topic.

Configuring WSAQUERYSET

The WSAQUERYSET structure must be configured according to the following specifications:

dwSize must specify the size the WSAQUERYSET structure.
lpszServiceInstanceName must point to the peer name that is being unregistered.
lpBlob must point to a PNRPINFO structure.
lpcsaBuffer must point to the address list.

Note

The remaining members are described in PNRP and WSASetService.

An Example of Unregistering a Peer Name

The following code snippet shows you how to unregister a peer name by providing the correct information when calling WSASetService using the WSAQUERYSET structure.

#define UNICODE
#include <initguid.h>
#include <p2p.h>

#pragma comment(lib, "ws2_32.lib")

//-------------------------------------------------------------------------
// Function: PnrpUnregister
//
// Purpose:  Unregister the given name from a PNRP cloud
//
// Arguments:
//   pwzIdentity : identity string originally used to register the name
//   pwzName     : name to unregister from PNRP
//   pwzCloud    : name of the cloud to unregister from, NULL = global cloud
//
// Returns:  HRESULT
//
HRESULT PnrpUnregister(PWSTR pwzIdentity, PWSTR pwzName, PWSTR pwzCloud)
{
    HRESULT         hr = S_OK;
    PNRPINFO        pnrpInfo = {0};
    BLOB            blPnrpData = {0};
    WSAQUERYSET     querySet = {0};
    INT             iRet;

    //
    // build the WSAQUERYSET required to unregister
    //
    pnrpInfo.dwSize = sizeof(pnrpInfo);
    pnrpInfo.dwLifetime = 60 * 60 * 8; // 8 hours
    pnrpInfo.lpwszIdentity = pwzIdentity;

    blPnrpData.cbSize = sizeof(pnrpInfo);
    blPnrpData.pBlobData = (BYTE*)&pnrpInfo;

    querySet.dwSize = sizeof(querySet);
    querySet.dwNameSpace = NS_PNRPNAME;
    querySet.lpServiceClassId = (LPGUID)&SVCID_PNRPNAME;
    querySet.lpszServiceInstanceName = pwzName;
    querySet.lpszContext = pwzCloud;
    querySet.lpBlob = &blPnrpData;

    // unregister the name with PNRP
    iRet = WSASetService(&querySet, RNRSERVICE_DELETE, 0);
    if (iRet != 0)
    {
        hr = HRESULT_FROM_WIN32(WSAGetLastError());
    }

    return hr;
}

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Unregistering a Peer Name