Microsoft Internet Security and Acceleration Server 2004 SDK


The SendTo method sends a buffer asynchronously on UDP sockets to a specified address. It performs an overlapped sendto operation.

  IFWXIOBuffer* pIOBuffer,
  SOCKADDR* Address,
  INT AddressLength,
  IFWXIOCompletion* pIFWXIOCompletion,
  UserContextType UserData


[in] Pointer to the buffer to send.
[in] When calling this method on an external socket, this sockaddr structure should contain the target address for a UDP datagram. When calling this method on an internal socket, this parameter should contain the address of the datagram source. This is typically the Internet address from which the pIOBuffer packet originated. That is, the internal socket is associated with the Internet address of the pIOBuffer packet.
[in] Length, in bytes, of the Address parameter.
[in] Pointer to an IFWXIOCompletion interface that receives a notification when the sendto operation is completed. Set this parameter to NULL if notification is not required.
[in] An opaque value to pass to the IFWXIOCompletion::CompleteAsyncIO notification method. This parameter provides a context to the notification.

Return Values

This method returns S_OK if the call is successful; otherwise, it returns an error code.

For an IFWXNetworkSocket interface created by a call to IFWXFirewall2::CreateSSLNetworkSocket, this method returns E_NOTIMPL.


To receive a notification when the sendto operation is completed, specify an IFWXIOCompletion interface pointer in the pIFWXIOCompletion parameter.


Server: Requires Windows Server 2003 or Windows 2000.
Version: Requires Internet Security and Acceleration Server 2004.
Header: Declared in Wspfwext.idl.

See Also