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PROTOCOL_INFO (Compact 2013)

  • Article

3/26/2014

This structure contains information about a protocol.

Syntax

typedef struct _PROTOCOL_INFO { 
  DWORD dwServiceFlags; 
  INT iAddressFamily; 
  INT iMaxSockAddr; 
  INT iMinSockAddr; 
  INT iSocketType; 
  INT iProtocol; 
  DWORD dwMessageSize; 
  LPTSTR lpProtocol;
} PROTOCOL_INFO;

Members

  • dwServiceFlags
    A set of bit flags that specifies the services provided by the protocol. The following table shows the bit flags you may set.

    Value

    Description

    XP_CONNECTIONLESS

    If this flag is set, the protocol provides connectionless (datagram) service. If this flag is clear, the protocol provides connection-oriented data transfer.

    XP_GUARANTEED_DELIVERY

    If this flag is set, the protocol guarantees that all data sent will reach the intended destination. If this flag is clear, there is no such guarantee.

    XP_GUARANTEED_ORDER

    If this flag is set, the protocol guarantees that data will arrive in the order in which it was sent. Note that this characteristic does not guarantee delivery of the data, only its order. If this flag is clear, the order of data sent is not guaranteed.

    XP_MESSAGE_ORIENTED

    If this flag is set, the protocol is message-oriented. A message-oriented protocol honors message boundaries. If this flag is clear, the protocol is stream oriented, and the concept of message boundaries is irrelevant.

    XP_PSEUDO_STREAM

    If this flag is set, the protocol is a message-oriented protocol that ignores message boundaries for all receive operations.

    This optional capability is useful when you do not want the protocol to frame messages. An application that requires stream-oriented characteristics can open a socket with type SOCK_STREAM for transport protocols that support this functionality, regardless of the value of iSocketType.

    XP_GRACEFUL_CLOSE

    If this flag is set, the protocol supports two-phase close operations, also known as graceful close operations. If this flag is clear, the protocol supports only abortive close operations.

    XP_EXPEDITED_DATA

    If this flag is set, the protocol supports expedited data, also known as urgent data.

    XP_CONNECT_DATA

    If this flag is set, the protocol supports connect data.

    XP_DISCONNECT_DATA

    If this flag is set, the protocol supports disconnect data.

    XP_SUPPORTS_BROADCAST

    If this flag is set, the protocol supports a broadcast mechanism.

    XP_SUPPORTS_MULTICAST

    If this flag is set, the protocol supports a multicast mechanism.

    XP_BANDWIDTH_ALLOCATION

    If this flag is set, the protocol supports a mechanism for allocating a guaranteed bandwidth to an application.

    XP_FRAGMENTATION

    If this flag is set, the protocol supports message fragmentation; physical network MTU is hidden from applications.

    XP_ENCRYPTS

    If this flag is set, the protocol supports data encryption.
  • iAddressFamily
    Value to pass as the af parameter when the socket (Windows Sockets) function is called to open a socket for the protocol. This address family value uniquely defines the structure of protocol addresses, also known as sockaddr structures, used by the protocol.
  • iMaxSockAddr
    Maximum length of a socket address supported by the protocol.
  • iMinSockAddr
    Minimum length of a socket address supported by the protocol.

  • iSocketType
    Value to pass as the type parameter when the socket (Windows Sockets) function is called to open a socket for the protocol.

    Note

    If XP_PSEUDO_STREAM is set in dwServiceFlags, the application can specify SOCK_STREAM as the type parameter to socket, regardless of the value of iSocketType.

  • iProtocol
    Value to pass as the protocol parameter when the socket (Windows Sockets) function is called to open a socket for the protocol.

  • dwMessageSize
    Maximum message size supported by the protocol. This is the maximum size of a message that can be sent from or received by the host. For protocols that do not support message framing, the actual maximum size of a message that can be sent to a given address may be less than this value.

    The following table shows the special message size values that are defined.

    Value

    Description

    0

    The protocol is stream-oriented; the concept of message size is not relevant.

    0xFFFFFFFF

    The protocol is message-oriented, but there is no maximum message size.
  • lpProtocol
    Points to a zero-terminated string that supplies a name for the protocol, for example, SPX2.

Requirements

Header

winsock2.h

See Also

Reference

Winsock Structures
socket (Windows Sockets)