socket.h

mgcp协议源代码。支持多种编码：g711

/*
 * socket.h
 *
 * Berkley Socket channel ancestor class.
 *
 * Portable Windows Library
 *
 * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: socket.h,v $
 * Revision 1.34  2000/06/26 13:58:42  robertj
 * Nucleus port (again)
 *
 * Revision 1.33  2000/06/26 11:17:19  robertj
 * Nucleus++ port (incomplete).
 *
 * Revision 1.32  2000/02/18 09:55:21  robertj
 * Added parameter so get/setsockopt can have other levels to SOL_SOCKET.
 *
 * Revision 1.31  1999/03/09 02:59:51  robertj
 * Changed comments to doc++ compatible documentation.
 *
 * Revision 1.30  1999/02/16 08:11:10  robertj
 * MSVC 6.0 compatibility changes.
 *
 * Revision 1.29  1998/11/30 02:51:58  robertj
 * New directory structure
 *
 * Revision 1.28  1998/09/23 06:21:25  robertj
 * Added open source copyright license.
 *
 * Revision 1.27  1998/08/27 00:46:58  robertj
 * Resolved signedness problems with various GNU libraries.
 *
 * Revision 1.26  1998/08/25 14:07:42  robertj
 * Added getprotobyxxx wrapper functions.
 *
 * Revision 1.25  1998/01/26 00:35:21  robertj
 * Fixed documentation of PSocket::Select().
 *
 * Revision 1.24  1996/09/14 13:09:24  robertj
 * Major upgrade:
 *   rearranged sockets to help support IPX.
 *   added indirect channel class and moved all protocols to descend from it,
 *   separating the protocol from the low level byte transport.
 *
 * Revision 1.23  1996/07/27 04:14:00  robertj
 * Changed Select() calls to return error codes.
 *
 * Revision 1.22  1996/05/15 10:11:38  robertj
 * Added timeout to accept function.
 *
 * Revision 1.21  1996/03/31 08:52:36  robertj
 * Added socket shutdown function.
 *
 * Revision 1.20  1996/03/18 13:33:12  robertj
 * Fixed incompatibilities to GNU compiler where PINDEX != int.
 *
 * Revision 1.19  1996/03/03 07:37:58  robertj
 * Added Reusability clause to the Listen() function on sockets.
 *
 * Revision 1.18  1996/03/02 03:10:18  robertj
 * Added Apability to get and set Berkeley socket options.
 *
 * Revision 1.17  1996/02/25 03:02:14  robertj
 * Moved some socket functions to platform dependent code.
 * Added array of fds to os_select for unix threading support.
 *
 * Revision 1.16  1996/02/15 14:46:43  robertj
 * Added Select() function to PSocket.
 *
 * Revision 1.15  1995/12/23 03:46:54  robertj
 * Fixed portability issue with closingh sockets.
 *
 * Revision 1.14  1995/12/10 11:35:21  robertj
 * Numerous fixes for sockets.
 *
 * Revision 1.13  1995/10/14 15:05:54  robertj
 * Added functions for changing integer from host to network byte order.
 *
 * Revision 1.12  1995/06/17 11:13:25  robertj
 * Documentation update.
 *
 * Revision 1.11  1995/06/17 00:44:35  robertj
 * More logical design of port numbers and service names.
 * Changed overloaded Open() calls to 3 separate function names.
 *
 * Revision 1.10  1995/06/04 12:36:37  robertj
 * Slight redesign of port numbers on sockets.
 *
 * Revision 1.9  1995/03/14 12:42:39  robertj
 * Updated documentation to use HTML codes.
 *
 * Revision 1.8  1995/03/12  04:45:40  robertj
 * Added more functionality.
 *
 * Revision 1.7  1995/01/03  09:36:19  robertj
 * Documentation.
 *
 * Revision 1.6  1995/01/02  12:16:17  robertj
 * Moved constructor to platform dependent code.
 *
 * Revision 1.5  1994/08/23  11:32:52  robertj
 * Oops
 *
 * Revision 1.4  1994/08/22  00:46:48  robertj
 * Added pragma fro GNU C++ compiler.
 *
 * Revision 1.3  1994/08/21  23:43:02  robertj
 * Changed type of socket port number for better portability.
 *
 * Revision 1.2  1994/07/25  03:36:03  robertj
 * Added sockets to common, normalising to same comment standard.
 *
 */

#define _PSOCKET

#ifdef __GNUC__
#pragma interface
#endif


#ifndef _PCHANNEL
#include <ptlib/channel.h>
#endif

#ifdef __NUCLEUS_PLUS__
#include <sys/socket.h>
#endif

class PSocket;

PLIST(PSocketList, PSocket);


/**A network communications channel. This is based on the concepts in the
   Berkley Sockets library.
   
   A socket represents a bidirectional communications channel to a {\it port}
   at a remote {\it host}.
 */
class PSocket : public PChannel
{
  PCLASSINFO(PSocket, PChannel);

  protected:
    PSocket();

  public:
  /**@name Socket establishment functions */
  //@{
    /**Connect a socket to a remote host on the specified port number. This is
       typically used by the client or initiator of a communications channel.
       This connects to a "listening" socket at the other end of the
       communications channel.

       @return
       TRUE if the channel was successfully connected to the remote host.
     */
    virtual BOOL Connect(
      const PString & address   /// Address of remote machine to connect to.
    );


    /// Flags to reuse of port numbers in Listen() function.
    enum Reusability {
      CanReuseAddress,
      AddressIsExclusive
    };

    /**Listen on a socket for a remote host on the specified port number. This
       may be used for server based applications. A "connecting" socket begins
       a connection by initiating a connection to this socket. An active socket
       of this type is then used to generate other "accepting" sockets which
       establish a two way communications channel with the "connecting" socket.

       If the #port# parameter is zero then the port number as
       defined by the object instance construction or the descendent classes
       SetPort() or SetService() function.

       @return
       TRUE if the channel was successfully opened.
     */
    virtual BOOL Listen(
      unsigned queueSize = 5,  /// Number of pending accepts that may be queued.
      WORD port = 0,           /// Port number to use for the connection.
      Reusability reuse = AddressIsExclusive /// Can/Cant listen more than once.
    );


    /**Open a socket to a remote host on the specified port number. This is an
       "accepting" socket. When a "listening" socket has a pending connection
       to make, this will accept a connection made by the "connecting" socket
       created to establish a link.

       The port that the socket uses is the one used in the #Listen()#
       command of the #socket# parameter. Note an error occurs if
       the #socket# parameter has not had the #Listen()#
       function called on it.

       Note that this function will block until a remote system connects to the
       port number specified in the "listening" socket. The time that the
       function will block is determined by the read timeout of the
       #socket# parameter. This will normally be
       #PMaxTimeInterval# which indicates an infinite time.

       The default behaviour is to assert.

       @return
       TRUE if the channel was successfully opened.
     */
    virtual BOOL Accept(
      PSocket & socket          /// Listening socket making the connection.
    );

    /**Close one or both of the data streams associated with a socket 

       @return
       TRUE if the shutdown was performed
     */
    virtual BOOL Shutdown(
      ShutdownValue option   /// Flag for shutdown of read, write or both.
    );
  //@}

  /**@name Socket options functions */
  //@{
    /**Set options on the socket. These options are defined as Berkeley socket
       options of the class SOL_SOCKET.

       @return
       TRUE if the option was successfully set.
     */
    BOOL SetOption(
      int option,             /// Option to set.
      int value,              /// New value for option.
      int level = SOL_SOCKET  /// Level for option
    );

    /**Set options on the socket. These options are defined as Berkeley socket
       options of the class SOL_SOCKET.

       @return
       TRUE if the option was successfully set.
     */
    BOOL SetOption(
      int option,             /// Option to set.
      const void * valuePtr,  /// Pointer to new value for option.
      PINDEX valueSize,       /// Size of new value.
      int level = SOL_SOCKET  /// Level for option
    );

    /**Get options on the socket. These options are defined as Berkeley socket
       options of the class SOL_SOCKET.

       @return
       TRUE if the option was successfully retreived.
     */
    BOOL GetOption(
      int option,             /// Option to get.
      int & value,            /// Integer to receive value.