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LPWSPSHUTDOWN callback function (ws2spi.h)

  • Article

The LPWSPShutdown function disables sends and/or receives on a socket.

Syntax

LPWSPSHUTDOWN Lpwspshutdown;

int Lpwspshutdown(
  [in]  SOCKET s,
  [in]  int how,
  [out] LPINT lpErrno
)
{...}

Parameters

[in] s

Descriptor identifying a socket.

[in] how

Flag that describes what types of operation will no longer be allowed.

[out] lpErrno

Pointer to the error code.

Return value

If no error occurs, LPWSPShutdown returns zero. Otherwise, a value of SOCKET_ERROR is returned, and a specific error code is available in lpErrno.

Error Code Meaning
WSAENETDOWN
 The network subsystem has failed.
WSAEINVAL
 The how is not valid, or is not consistent with the socket type. For example, SD_SEND is used with a UNI_RECV socket type.
WSAEINPROGRESS
 Function is invoked when a callback is in progress.
WSAENOTCONN
 Socket is not connected (connection-oriented sockets only).
WSAENOTSOCK
 The descriptor is not a socket.

Remarks

The LPWSPShutdown function is used on all types of sockets to disable reception, transmission, or both.

If how is SD_RECEIVE, subsequent receives on the socket will be disallowed. This has no effect on the lower protocol layers. For TCP sockets, if there is still data queued on the socket waiting to be received, or data arrives subsequently, the connection is reset, since the data cannot be delivered to the user. For UDP sockets, incoming datagrams are accepted and queued. In no case will an ICMP error packet be generated.

If how is SD_SEND, subsequent sends on the socket are disallowed. For TCP sockets, a FIN will be sent. Setting how to SD_BOTH disables both sends and receives as described above.

Note that LPWSPShutdown does not close the socket, and resources attached to the socket will not be freed until LPWSPCloseSocket is invoked.

Note

The LPWSPShutdown function does not block regardless of the SO_LINGER setting on the socket. A Windows Sockets SPI client should not rely on being able to reuse a socket after it has been shut down. In particular, a Windows Sockets service provider is not required to support the use of LPWSPConnect on such a socket.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header ws2spi.h

See also

LPWSPConnect

LPWSPSocket