getsockname

The Windows Sockets getsockname function retrieves the local name for a socket.

int getsockname (
  SOCKET s,                    
  struct sockaddr FAR*  name,  
  int FAR*  namelen            
);

Parameters

s: [in] A descriptor identifying a bound socket.
name: [out] Receives the address (name) of the socket.
namelen: [in/out] The size of the name buffer.

Remarks

The getsockname function retrieves the current name for the specified socket descriptor in name. It is used on the bound or connected socket specified by the s parameter. The local association is returned. This call is especially useful when a connect call has been made without doing a bind first; the getsockname function provides the only way to determine the local association that has been set by the system.

On call, the namelen argument contains the size of the name buffer, in bytes. On return, the namelen parameter contains the actual size in bytes of the name parameter.

The getsockname function does not always return information about the host address when the socket has been bound to an unspecified address, unless the socket has been connected with connect or accept (for example, using ADDR_ANY). A Windows Sockets application must not assume that the address will be specified unless the socket is connected. The address that will be used for the socket is unknown unless the socket is connected when used in a multihomed host. If the socket is using a connectionless protocol, the address may not be available until I/O occurs on the socket.

Return Values

If no error occurs, getsockname returns zero. Otherwise, a value of SOCKET_ERROR is returned, and a specific error code can be retrieved by calling WSAGetLastError.

Error Codes

WSANOTINITIALISED	A successful WSAStartup must occur before using this function.
WSAENETDOWN	The network subsystem has failed.
WSAEFAULT	The name or the namelen parameter is not a valid part of the user address space, or the namelen parameter is too small.
WSAEINPROGRESS	A blocking Windows Sockets 1.1 call is in progress, or the service provider is still processing a callback function.
WSAENOTSOCK	The descriptor is not a socket.
WSAEINVAL	The socket has not been bound to an address with bind, or ADDR_ANY is specified in bind but connection has not yet occurs.

QuickInfo