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PNRP and WSANSPIoctl

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PNRP uses the WSANSPIoctl function to receive notifications about changes to the following:

  • A network cloud list
  • Availability of results of a name resolution request

The first call to WSALookupServiceBegin defines the type of information that a client is notified about. A client can be notified with a Windows message, a completion routine, a handle to a WSAEVENT object, or a port. For more information about options and setting the lpCompletion parameter, see WSANSPIoctl.

To continue receiving notifications after a call to WSALookupServiceNext, an application must call WSANSPIoctl again.

The WSALookupServiceNext function blocks even if WSANSPIoctl is called. Before calling WSALookupServiceNext, an application must wait until it receives a notification—if blocking is an issue.

When calling this function, the parameters must have the following values:

hLookup

Specifies the handle that WSALookupServiceBegin returns.

dwControlCode

Must be SIO_NSP_NOTIFY_CHANGE.

lpvInBuffer

Must be NULL.

cbInBuffer

Must be zero (0).

lpvOutBuffer

Must be NULL.

cbOutBuffer

Must be zero (0).

lpcbBytesReturned

Must be NULL.

lpCompletion

Specifies either NULL or a pointer to a WSACOMPLETION structure.

After a notification is received, call WSALookupServiceNext one time to obtain the results.

To end a search, call WSALookupServiceEnd.

Resolution Notifications

A client can be notified any time that a name resolution entry is added. The client then calls WSALookupServiceNext to obtain the resolution data.

If the client does not use this technique, a call to WSALookupServiceNext can be blocked until the specified timeout occurs.

Cloud List Notifications

A client can be notified any time there is a change to a set of clouds.

The WSALookupServiceNext function returns WSA_E_NO_MORE as a set delimiter. The client application must enumerate existing clouds until this message is returned, and then use a notification scheme to retrieve subsequent changes as they occur. A client application can also call WSALookupServiceNext, but the call is blocked until a change occurs.

The WSALookupServiceNext function returns a cloud in a WSAQUERYSET structure. One of the following flags is returned in the dwOutputFlags member.

Value Description
RESULT_IS_ADDED The cloud that is returned is added.
RESULT_IS_CHANGED The cloud that is returned is changed.
RESULT_IS_DELETED The cloud that is returned is deleted and is not valid.

 

PNRP and WSALookupServiceBegin

PNRP and WSALookupServiceEnd

PNRP and WSAQUERYSET

PNRP NSP Error Codes

WSANSPIoctl

WSALookupServiceBegin

WSALookupServiceEnd

WSAQUERYSET