LPNSPV2SETSERVICEEX callback function (ws2spi.h)

Article
10/13/2021

The NSPv2SetServiceEx function registers or deregisters a name or service instance within a namespace of a namespace service provider version-2 (NSPv2) provider.

Syntax

LPNSPV2SETSERVICEEX Lpnspv2setserviceex;

void Lpnspv2setserviceex(
  [in] HANDLE hAsyncCall,
  [in] LPGUID lpProviderId,
  [in] LPWSAQUERYSET2W lpqsRegInfo,
  [in] WSAESETSERVICEOP essOperation,
  [in] DWORD dwControlFlags,
  [in] LPVOID lpvClientSessionArg
)
{...}

Parameters

[in] hAsyncCall

A handle returned from the previous call to NSPv2LookupServiceBegin used for asynchronous calls.

[in] lpProviderId

A pointer to the GUID of the specific namespace provider in which the name or service is registered.

[in] lpqsRegInfo

The property information to be updated upon registration.

[in] essOperation

The type of operation requested.

This parameter can be one of the values from the WSAESETSERVICEOP enumeration type defined in the Winsock2.h header file.

Value	Meaning
RNRSERVICE_REGISTER 0	Register the service. For the Service Advertising Protocol (SAP) namespace used within a NetWare environment, this means sending a periodic broadcast. This is an NOP for the Domain Name System (DNS) namespace. For persistent data stores this means updating the address information.
RNRSERVICE_DEREGISTER 1	Deregister the service. For the SAP namespace, this means stop sending the periodic broadcast. This is a NOP for the DNS namespace. For persistent data stores this means deleting address information.
RNRSERVICE_DELETE 2	Delete the service from dynamic name and persistent spaces. For services represented by multiple CSADDR_INFO structures (using the SERVICE_MULTIPLE flag), only the supplied address will be deleted, and this must match exactly the corresponding CSADDR_INFO structure supplied when the service was registered.

[in] dwControlFlags

A set of flags that controls the operation requested.

The possible values for this parameter are defined in the Winsock2.h header file.

Value	Meaning
SERVICE_MULTIPLE 0x00000001	Control the scope of the operation. When this value is set, the action is only performed on the given address set. A register operation does not invalidate existing addresses and a deregister operation only invalidates the given set of addresses. When this value is absent, service addresses are managed as a group. A register or deregister invalidates all existing addresses before adding the given address set.

Value

Meaning

SERVICE_MULTIPLE

0x00000001

Control the scope of the operation.

When this value is set, the action is only performed on the given address set. A register operation does not invalidate existing addresses and a deregister operation only invalidates the given set of addresses.

When this value is absent, service addresses are managed as a group. A register or deregister invalidates all existing addresses before adding the given address set.

[in] lpvClientSessionArg

A pointer to the client session.

Return value

The function should return NO_ERROR (zero) if the routine succeeds. It should return SOCKET_ERROR (that is, 1) if the routine fails and it must set the appropriate error code using WSASetLastError.

Error code	Meaning
WSA_NOT_ENOUGH_MEMORY	There is not enough memory available to perform this operation.
WSAEACCES	The calling routine does not have sufficient privileges to install the service.
WSAEINVAL	One or more parameters were invalid, or missing, for this provider.
WSAEOPNOTSUPP	The operation is not supported. This error is returned if the namespace provider does not implement this function. This error can also be returned if the specified dwControlCode is an unrecognized command.
WSASERVICE_NOT_FOUND	Service is unknown. The service cannot be found in the specified namespace.

Remarks

The NSPv2SetServiceEx function is used as part of the namespace service provider version-2 (NSPv2) architecture available on Windows Vista and later.

On Windows Vista and Windows Server 2008, the NSPv2SetServiceEx function can only be used for operations on NS_EMAIL namespace providers.

The NSPv2Startup function is called each time a new client process begins using namespace provider. Providers may use the client session argument pointed to by the ppvClientSessionArg parameter to store information about this session. This client session argument can be passed to the NSPv2SetServiceEx function in the lpvClientSessionArg parameter.

The NSPv2SetServiceEx function is optional, dependent on the requirements of the NSPv2 provider. If the NSPv2SetServiceEx function isn't implemented, then the NSPv2 function pointer can be to a stub function that always returns NO_ERROR.

The following table lists the possible combination of values for essOperation and dwControlFlags parameters.

essOperation	dwControlFlags	Service already exists	Service does not exist
RNRSERVICE_REGISTER	None	Overwrites the object. Uses only addresses specified. Object is REGISTERED.	Creates a new object. Uses only addresses specified. Object is REGISTERED.
RNRSERVICE_REGISTER	SERVICE_MULTIPLE	Updates object. Adds new addresses to existing set. Object is REGISTERED.	Creates a new object. Uses all addresses specified. Object is REGISTERED.
RNRSERVICE_DEREGISTER	None	Removes all addresses, but does not remove object from namespace. Object is DEREGISTERED.	WSASERVICE_NOT_FOUND
RNRSERVICE_DEREGISTER	SERVICE_MULTIPLE	Updates object. Removes only addresses that are specified. Only mark object as DEREGISTERED if no addresses are present. Does not remove from the namespace.	WSASERVICE_NOT_FOUND
RNRSERVICE_DELETE	None	Removes object from the namespace.	WSASERVICE_NOT_FOUND
RNRSERVICE_DELETE	SERVICE_MULTIPLE	Removes only addresses that are specified. Only removes object from the namespace if no addresses remain.	WSASERVICE_NOT_FOUND

When the dwControlFlags parameter is set to SERVICE_MULTIPLE, this enables an application to manage its addresses independently. This is useful when the application must manage its protocols individually or when the service resides on more than one computer. For example, when a service uses more than one protocol, one listening socket may abort, but the other sockets remain operational. In this example, the service could deregister the aborted address without affecting the other addresses.

When using SERVICE_MULTIPLE, an application must not let old addresses remain in the object. This can happen if the application aborts without issuing a RNRSERVICE_DEREGISTER request. When a service registers, it should store its addresses. On its next call, the service should explicitly deregister these old addresses before registering new addresses.

If the NSPv2SetServiceEx function isn't implemented, then calls to that function should be intercepted by a stub function that returns WSAEOPNOTSUPP. The NSPv2 function pointer to the unimplemented NSPv2SetServiceEx function in the NSPV2_ROUTINE structure should point be to the stub function.

Service Properties

The following table lists WSAQUERYSET2 member names and describes how service property data is represented. Members labeled as optional and dependent on the requirements of the NSPv2 provider may be supplied as a **NULL** pointer when unused by the namespace provider.

WSAQUERYSET2 member name	Service property description
dwSize	Set to the sizeof(WSAQUERYSET2). This is a versioning mechanism.
lpszServiceInstanceName	A string that contains the service instance name.
lpVersion	The service instance version number. This member is optional, dependent on the requirements of the NSPv2 service provider.
lpszComment	A comment string. This member is optional, dependent on the requirements of the NSPv2 service provider.
dwNameSpace	The namespace identifier. This member is optional, dependent on the requirements of the NSPv2 service provider.
lpNSProviderId	The provider identifier. Note that the namespace provider identifier is also passed in the lpProviderId parameter. This member is optional, dependent on the requirements of the NSPv2 service provider.
lpszContext	The starting point of the query in a hierarchical namespace. This member is optional, dependent on the requirements of the NSPv2 service provider.
dwNumberOfProtocols	The size, in bytes, of the number of entries in the protocol constraint array. This member can be zero.This member is optional, dependent on the requirements of the NSPv2 service provider.
lpafpProtocols	An array of AFPROTOCOLS structures. This member is optional, dependent on the requirements of the NSPv2 service provider.
lpszQueryString	Some namespaces (such as whois++) support rich SQL-like queries contained in a simple text string. This parameter is used to specify that string.This member is optional, dependent on the requirements of the NSPv2 service provider.
dwNumberOfCsAddrs	The number of elements in the array of CSADDR_INFO structures referenced by lpcsaBuffer.
lpcsaBuffer	A pointer to an array of CSADDR_INFO structures that contain the address or addresses that the service is listening on.
dwOutputFlags	This member is optional, dependent on the requirements of the NSPv2 service provider.
lpBlob	A pointer to a provider-specific entity. This member is required for the NS_EMAIL namespace. This member is optional, dependent on the requirements for other NSPv2 service providers.

**Note** It is acceptable for the **iProtocol** member of the CSADDR_INFO structure to contain the manifest constant **IPROTOCOL_ANY**, indicating a wildcard value. The namespace provider should substitute an acceptable value for the given address family and socket type.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Target Platform	Windows
Header	ws2spi.h