InetConnect Function  
 
SOCKET WINAPI InetConnect(
  LPCTSTR lpszHostName,  
  UINT nPort,  
  UINT nProtocol,  
  UINT nTimeout,  
  DWORD dwOptions,  
  LPSECURITYCREDENTIALS lpCredentials  
);

Parameters

lpszHostName
A pointer to the name of the server to connect to; this may be a fully-qualified domain name or an IP address.
nPort
The port number the server is listening on. This value must be greater than zero.
nProtocol
The protocol to be used when establishing the connection. This may be one of the following values:
Constant Description
INET_PROTOCOL_TCP Specifies the Transmission Control Protocol. This protocol provides a reliable, bi-directional byte stream. This is the default protocol.
INET_PROTOCOL_UDP Specifies the User Datagram Protocol. This protocol is message oriented, sending data in discrete packets. Note that UDP is unreliable in that there is no way for the sender to know that the receiver has actually received the datagram.
nTimeout
The number of seconds to wait for the connection to complete before failing the current operation.
dwOptions
An unsigned long integer used to specify one or more socket options. This parameter is constructed by using the bitwise Or operator with any of the following values:
Constant Description
INET_OPTION_BROADCAST This option specifies that broadcasting should be enabled for datagrams. This option is invalid for stream sockets.
INET_OPTION_DONTROUTE This option specifies default routing should not be used. This option should not be specified unless absolutely necessary.
INET_OPTION_KEEPALIVE This option specifies that packets are to be sent to the remote system when no data is being exchanged to keep the connection active. This is only valid for stream sockets.
INET_OPTION_NODELAY This option disables the Nagle algorithm, which buffers unacknowledged data and insures that a full-size packet can be sent to the remote host.
INET_OPTION_SECURE This option specifies that a secure connection should be established with the remote host.
INET_OPTION_FREETHREAD This option specifies that the socket returned by this function may be used by any thread, and is not limited to the thread which created it. The application is responsible for ensuring that access to the socket is synchronized across multiple threads.
lpCredentials
A pointer to a SECURITYCREDENTIALS structure. This parameter is only used if INET_OPTION_SECURE is specified for a TCP connection. This parameter may be NULL, in which case no client credentials will be provided to the server. If client credentials are required, the fields dwSize, lpszCertStore, and lpszCertName must be defined, while other fields may be left undefined. Set dwSize to the size of the SECURITYCREDENTIALS structure.

Return Value

If the function succeeds, the return value is a handle to a socket. If the function fails, the return value is INVALID_SOCKET. To get extended error information, call InetGetLastError.

Remarks

When this function is called with UDP as the specified protocol, it does not actually establish a connection. Instead, it simply establishes a default destination IP address and port that is used with subsequent InetRead and InetWrite calls.

To enable asynchronous event notification, use the InetEnableEvents function.

Requirements

Client: Requires Windows 7, Windows Vista or Windows XP.
Server: Requires Windows Server 2008 or Windows Server 2003.
Header: Include cswsock7.h.
Library: Use cswskav7.lib.
Unicode: Implemented as Unicode and ANSI versions.

See Also

InetAsyncConnect, InetAsyncConnectEx, InetConnectEx, InetDisableEvents, InetDisconnect, InetEnableEvents, InetInitialize, InetRead, InetWrite