sockets.cxx

mgcp协议源代码。支持多种编码：g711

/*
 * sockets.cxx
 *
 * Berkley sockets classes.
 *
 * 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: sockets.cxx,v $
 * Revision 1.103  2000/06/26 11:17:21  robertj
 * Nucleus++ port (incomplete).
 *
 * Revision 1.102  2000/06/21 01:01:22  robertj
 * AIX port, thanks Wolfgang Platzer ([e-mail]).
 *
 * Revision 1.101  2000/05/02 08:14:40  craigs
 * Fixed problem with "memory leak" reporting under Unix
 *
 * Revision 1.100  2000/04/27 02:43:45  robertj
 * Fixed warning about signedness mismatch.
 *
 * Revision 1.99  2000/04/19 00:13:52  robertj
 * BeOS port changes.
 *
 * Revision 1.98  2000/02/18 09:55:21  robertj
 * Added parameter so get/setsockopt can have other levels to SOL_SOCKET.
 *
 * Revision 1.97  1999/10/27 01:21:44  robertj
 * Improved portability of copy from host_info struct to IP address.
 *
 * Revision 1.96  1999/08/30 02:21:03  robertj
 * Added ability to listen to specific interfaces for IP sockets.
 *
 * Revision 1.95  1999/08/27 08:18:52  robertj
 * Added ability to get the host/port of the the last packet read/written to UDP socket.
 *
 * Revision 1.94  1999/08/08 09:04:01  robertj
 * Added operator>> for PIPSocket::Address class.
 *
 * Revision 1.93  1999/07/11 13:42:13  craigs
 * pthreads support for Linux
 *
 * Revision 1.92  1999/06/01 08:04:35  robertj
 * Fixed mistake from previous fix.
 *
 * Revision 1.91  1999/06/01 07:39:23  robertj
 * Added retries to DNS lookup if get temporary error.
 *
 * Revision 1.90  1999/03/09 08:13:52  robertj
 * Fixed race condition in doing Select() on closed sockets. Could go into infinite wait.
 *
 * Revision 1.89  1999/03/02 05:41:58  robertj
 * More BeOS changes
 *
 * Revision 1.88  1999/02/26 04:10:39  robertj
 * More BeOS port changes
 *
 * Revision 1.87  1999/02/25 03:43:35  robertj
 * Fixed warning when PINDEX is unsigned.
 *
 * Revision 1.86  1999/02/23 07:19:22  robertj
 * Added [] operator PIPSocket::Address to get the bytes out of an IP address.
 *
 * Revision 1.85  1999/02/16 08:08:06  robertj
 * MSVC 6.0 compatibility changes.
 *
 * Revision 1.84  1999/01/08 01:29:47  robertj
 * Support for pthreads under FreeBSD
 *
 * Revision 1.83  1999/01/06 10:58:01  robertj
 * Fixed subtle mutex bug in returning string hostname from DNS cache.
 *
 * Revision 1.82  1998/12/22 10:25:01  robertj
 * Added clone() function to support SOCKS in FTP style protocols.
 * Fixed internal use of new operator in IP cache.
 *
 * Revision 1.81  1998/12/18 04:34:37  robertj
 * PPC Linux GNU C compatibility.
 *
 * Revision 1.80  1998/11/30 04:47:52  robertj
 * New directory structure
 *
 * Revision 1.79  1998/11/14 06:28:36  robertj
 * Changed senatics of os_sendto to return TRUE if ANY bytes are sent.
 *
 * Revision 1.78  1998/11/08 12:05:04  robertj
 * Fixed multiple thread access problem with DNS aliases array.
 *
 * Revision 1.77  1998/10/01 09:05:35  robertj
 * Added check that port number is between 1 and 65535.
 *
 * Revision 1.76  1998/09/23 06:22:44  robertj
 * Added open source copyright license.
 *
 * Revision 1.75  1998/08/31 13:00:34  robertj
 * Prevented dependency on snmpapi.dll for all ptlib apps.
 *
 * Revision 1.74  1998/08/27 00:58:42  robertj
 * Resolved signedness problems with various GNU libraries.
 *
 * Revision 1.73  1998/08/25 14:07:43  robertj
 * Added getprotobyxxx wrapper functions.
 *
 * Revision 1.72  1998/08/25 11:09:20  robertj
 * Fixed parsing of 802.x header on ethernet frames.
 * Changed DNS cache to not cache temporary lookup failures, only an authoratative 'no such host'.
 *
 * Revision 1.71  1998/08/21 05:26:10  robertj
 * Fixed bug where write streams out to non-stream socket.
 * Added ethernet socket.
 *
 * Revision 1.70  1998/05/07 05:20:25  robertj
 * Fixed DNS lookup so only works around bug in old Win95 and not OSR2
 *
 * Revision 1.69  1998/03/20 03:18:21  robertj
 * Added special classes for specific sepahores, PMutex and PSyncPoint.
 *
 * Revision 1.68  1998/03/05 12:45:48  robertj
 * DNS cache and NT bug fix attempts.
 *
 * Revision 1.67  1998/01/26 02:49:22  robertj
 * GNU support.
 *
 * Revision 1.66  1998/01/26 00:49:28  robertj
 * Fixed bug in detecting local host on NT, 95 bug kludge was interfering with it.
 *
 * Revision 1.65  1998/01/06 12:43:23  craigs
 * Added definition of REENTRANT_BUFFER_LEN
 *
 * Revision 1.64  1998/01/04 07:25:09  robertj
 * Added pthreads compatible calls for gethostbyx functions.
 *
 * Revision 1.63  1997/12/18 05:06:13  robertj
 * Moved IsLocalHost() to platform dependent code.
 *
 * Revision 1.62  1997/12/11 10:30:35  robertj
 * Added operators for IP address to DWORD conversions.
 *
 * Revision 1.61  1997/10/03 13:33:22  robertj
 * Added workaround for NT winsock bug with RAS and DNS lookups.
 *
 * Revision 1.60  1997/09/27 00:58:39  robertj
 * Fixed race condition on socket close in Select() function.
 *
 * Revision 1.59  1997/06/06 10:56:36  craigs
 * Added new functions for connectionless UDP writes
 *
 * Revision 1.58  1997/01/04 07:42:18  robertj
 * Fixed GCC Warnings.
 *
 * Revision 1.57  1997/01/04 06:54:38  robertj
 * Added missing canonical name to alias list.
 *
 * Revision 1.56  1996/12/17 11:07:05  robertj
 * Added clear of name cache.
 *
 * Revision 1.55  1996/12/12 09:23:27  robertj
 * Fixed name cache to cache missing names as well.
 * Fixed new connect with specific local port so can be re-used (simultaneous FTP session bug)
 *
 * Revision 1.54  1996/12/05 11:46:39  craigs
 * Fixed problem with Win95 recvfrom not having timeouts
 *
 * Revision 1.53  1996/11/30 12:08:17  robertj
 * Added Connect() variant so can set the local port number on link.
 *
 * Revision 1.52  1996/11/16 10:49:03  robertj
 * Fixed missing const in PIPSocket::Address stream output operator..
 *
 * Revision 1.51  1996/11/16 01:43:49  craigs
 * Fixed problem with ambiguous DNS cache keys
 *
 * Revision 1.50  1996/11/10 21:08:31  robertj
 * Added host name caching.
 *
 * Revision 1.49  1996/11/04 03:40:22  robertj
 * Moved address printer from inline to source.
 *
 * Revision 1.48  1996/10/26 01:41:09  robertj
 * Compensated for Win'95 gethostbyaddr bug.
 *
 * Revision 1.47  1996/09/14 13:09:40  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 1.46  1996/08/25 09:33:32  robertj
 * Added function to detect "local" host name.
 *
 * Revision 1.45  1996/07/30 12:24:53  robertj
 * Fixed incorrect conditional stopping Select() from working.
 *
 * Revision 1.44  1996/07/27 04:10:35  robertj
 * Changed Select() calls to return error codes.
 *
 * Revision 1.43  1996/06/10 09:58:21  robertj
 * Fixed win95 compatibility with looking up zero address (got a response and shouldn't).
 *
 * Revision 1.42  1996/05/26 03:47:03  robertj
 * Compatibility to GNU 2.7.x
 *
 * Revision 1.39  1996/04/29 12:20:01  robertj
 * Fixed GetHostAliases() so doesn't overwrite names with IP numbers.
 *
 * Revision 1.38  1996/04/15 10:59:41  robertj
 * Opened socket on UDP sockets so ReadFrom/WriteTo work when no Connect/Listen.
 *
 * Revision 1.37  1996/03/31 09:06:41  robertj
 * Added socket shutdown function.
 *
 * Revision 1.35  1996/03/18 13:33:18  robertj
 * Fixed incompatibilities to GNU compiler where PINDEX != int.
 *
 * Revision 1.34  1996/03/17 05:51:18  robertj
 * Fixed strange bug in accept cant have NULL address.
 *
 * Revision 1.33  1996/03/16 04:52:20  robertj
 * Changed all the get host name and get host address functions to be more consistent.
 *
 * Revision 1.32  1996/03/04 12:21:00  robertj
 * Split file into telnet.cxx
 *
 * Revision 1.31  1996/03/03 07:38:45  robertj
 * Added Reusability clause to the Listen() function on sockets.
 *
 * Revision 1.30  1996/03/02 03:25:13  robertj
 * Added Capability to get and set Berkeley socket options.
 *
 * Revision 1.29  1996/02/25 11:30:08  robertj
 * Changed Listen so can do a listen on a socket that is connected.
 *
 * Revision 1.28  1996/02/25 03:10:55  robertj
 * Moved some socket functions to platform dependent code.
 *
 * Revision 1.27  1996/02/19 13:30:15  robertj
 * Fixed bug in getting port by service name when specifying service by string number.
 * Added SO_LINGER option to socket to stop data loss on close.
 *
 * Revision 1.26  1996/02/15 14:46:44  robertj
 * Added Select() function to PSocket.
 *
 * Revision 1.25  1996/02/13 13:08:09  robertj
 * Fixed usage of sock_addr structure, not being cleared correctly.
 *
 * Revision 1.24  1996/02/08 12:27:22  robertj
 * Added function to get peer port as well as IP number..
 *
 * Revision 1.23  1996/02/03 11:07:37  robertj
 * Fixed buf in assuring error when converting string to IP number and string is empty.
 *
 * Revision 1.22  1996/01/28 14:08:13  robertj
 * Changed service parameter to PString for ease of use in GetPortByService function
 * Fixed up comments.
 * Added default value in string for service name.
 *
 * Revision 1.21  1996/01/23 13:19:13  robertj
 * Moved Accept() function to platform dependent code.
 *
 * Revision 1.20  1995/12/23 03:42:53  robertj
 * Unix portability issues.
 *
 * Revision 1.19  1995/12/10 11:42:23  robertj
 * Numerous fixes for sockets.
 *
 * Revision 1.18  1995/10/14 15:11:31  robertj
 * Added internet address to string conversion functionality.
 *
 * Revision 1.17  1995/07/02 01:21:23  robertj
 * Added static functions to get the current host name/address.
 *
 * Revision 1.16  1995/06/17 00:47:01  robertj
 * Changed overloaded Open() calls to 3 separate function names.
 * More logical design of port numbers and service names.
 *
 * Revision 1.15  1995/06/04 12:45:33  robertj
 * Added application layer protocol sockets.
 * Slight redesign of port numbers on sockets.
 *
 * Revision 1.14  1995/04/25 11:12:44  robertj
 * Fixed functions hiding ancestor virtuals.
 *
 * Revision 1.13  1995/04/01 08:31:54  robertj
 * Finally got a working TELNET.
 *
 * Revision 1.12  1995/03/18 06:27:49  robertj
 * Rewrite of telnet socket protocol according to RFC1143.
 *
 * Revision 1.11  1995/03/12  04:46:29  robertj
 * Added more functionality.
 *
 * Revision 1.10  1995/02/21  11:25:29  robertj
 * Further implementation of telnet socket, feature complete now.
 *
 * Revision 1.9  1995/01/27  11:16:16  robertj
 * Fixed missing cast in function, required by some platforms.
 *
 * Revision 1.8  1995/01/15  04:55:47  robertj
 * Moved all Berkley socket functions inside #ifdef.
 *
 * Revision 1.7  1995/01/04  10:57:08  robertj
 * Changed for HPUX and GNU2.6.x
 *
 * Revision 1.6  1995/01/03  09:37:52  robertj
 * Added constructor to open TCP socket.
 *
 * Revision 1.5  1995/01/02  12:28:25  robertj
 * Documentation.
 * Added more socket functions.
 *
 * Revision 1.4  1995/01/01  01:06:58  robertj
 * More implementation.
 *
 * Revision 1.3  1994/11/28  12:38:49  robertj
 * Added DONT and WONT states.
 *
 * Revision 1.2  1994/08/21  23:43:02  robertj
 * Some implementation.
 *
 * Revision 1.1  1994/08/01  03:39:05  robertj
 * Initial revision
 *
 */

#ifdef __NUCLEUS_PLUS__
#include <ConfigurationClass.h>
#endif

#include <ptlib.h>
#include <ptlib/sockets.h>

#include <ctype.h>

#if (defined(_WIN32) || defined(WINDOWS)) && !defined(__NUCLEUS_MNT__)
static PWinSock dummyForWinSock; // Assure winsock is initialised
#endif

#if (defined(P_PTHREADS) && !defined(P_THREAD_SAFE_CLIB)) || defined(__NUCLEUS_PLUS__)
#define REENTRANT_BUFFER_LEN 1024
#endif


class PIPCacheData : public PObject
{
  PCLASSINFO(PIPCacheData, PObject)
  public:
    PIPCacheData(struct hostent * ent, const char * original);
    const PString & GetHostName() const { return hostname; }
    const PIPSocket::Address & GetHostAddress() const { return address; }
    const PStringList & GetHostAliases() const { return aliases; }
    BOOL HasAged() const;
  private:
    PString            hostname;
    PIPSocket::Address address;
    PStringList        aliases;
    PTime              birthDate;
};


PDICTIONARY(PHostByName_private, PCaselessString, PIPCacheData);

class PHostByName : PHostByName_private
{
  public:
    BOOL GetHostName(const PString & name, PString & hostname);
    BOOL GetHostAddress(const PString & name, PIPSocket::Address & address);
    BOOL GetHostAliases(const PString & name, PStringArray & aliases);
  private:
    PIPCacheData * GetHost(const PString & name);
    PMutex mutex;
  friend void PIPSocket::ClearNameCache();
};

static PHostByName & pHostByName()
{
  static PHostByName t;
  return t;
}

class PIPCacheKey : public PObject
{
  PCLASSINFO(PIPCacheKey, PObject)
  public:
    PIPCacheKey(const PIPSocket::Address & a)
      { addr = a; }

    PObject * Clone() const
      { return new PIPCacheKey(*this); }

    PINDEX HashFunction() const
      { return (addr.Byte2() + addr.Byte3() + addr.Byte4())%41; }

  private:
    PIPSocket::Address addr;
};

PDICTIONARY(PHostByAddr_private, PIPCacheKey, PIPCacheData);

class PHostByAddr : PHostByAddr_private
{
  public:
    BOOL GetHostName(const PIPSocket::Address & addr, PString & hostname);
    BOOL GetHostAddress(const PIPSocket::Address & addr, PIPSocket::Address & address);
    BOOL GetHostAliases(const PIPSocket::Address & addr, PStringArray & aliases);
  private:
    PIPCacheData * GetHost(const PIPSocket::Address & addr);
    PMutex mutex;
  friend void PIPSocket::ClearNameCache();
};

static PHostByAddr & pHostByAddr()
{
  static PHostByAddr t;
  return t;
}

#define new PNEW


//////////////////////////////////////////////////////////////////////////////
// IP Caching

PIPCacheData::PIPCacheData(struct hostent * host_info, const char * original)
{
  if (host_info == NULL) {
    address.s_addr = 0;
    return;
  }

  hostname = host_info->h_name;
  address = *(DWORD *)host_info->h_addr;

  aliases.AppendString(host_info->h_name);

  PINDEX i;
  for (i = 0; host_info->h_aliases[i] != NULL; i++)
    aliases.AppendString(host_info->h_aliases[i]);

  for (i = 0; host_info->h_addr_list[i] != NULL; i++)
    aliases.AppendString(inet_ntoa(*(struct in_addr *)host_info->h_addr_list[i]));

  for (i = 0; i < aliases.GetSize(); i++)
    if (aliases[i] *= original)
      return;

  aliases.AppendString(original);
}


static PTimeInterval GetConfigTime(const char * key, DWORD dflt)
{
  PConfig cfg("DNS Cache");
  return cfg.GetInteger(key, dflt);
}

BOOL PIPCacheData::HasAged() const
{
  static PTimeInterval retirement = GetConfigTime("Age Limit", 300000); // 5 minutes
  PTime now;
  PTimeInterval age = now - birthDate;
  return age > retirement;
}


BOOL PHostByName::GetHostName(const PString & name, PString & hostname)
{
  PIPCacheData * host = GetHost(name);

  if (host != NULL) {
    hostname = host->GetHostName();
    hostname.MakeUnique();
  }

  mutex.Signal();

  return host != NULL;
}


BOOL PHostByName::GetHostAddress(const PString & name, PIPSocket::Address & address)
{
  PIPCacheData * host = GetHost(name);

  if (host != NULL)
    address = host->GetHostAddress();

  mutex.Signal();

  return host != NULL;
}


BOOL PHostByName::GetHostAliases(const PString & name, PStringArray & aliases)
{
  PIPCacheData * host = GetHost(name);

  if (host != NULL) {
    const PStringList & a = host->GetHostAliases();
    aliases.SetSize(a.GetSize());
    for (PINDEX i = 0; i < a.GetSize(); i++)
      aliases[i] = a[i];
  }

  mutex.Signal();
  return host != NULL;
}


PIPCacheData * PHostByName::GetHost(const PString & name)
{
  mutex.Wait();

  PCaselessString key = name;
  PIPCacheData * host = GetAt(key);

  if (host != NULL && host->HasAged()) {
    SetAt(key, NULL);
    host = NULL;
  }

  if (host == NULL) {
    mutex.Signal();

#ifdef P_AIX
    struct hostent_data ht_data;
    memset(&ht_data, 0, sizeof(ht_data)); 
    struct hostent host_info;
#else
    struct hostent * host_info;
#endif

    int retry = 3;
    do {
#if ( ( defined(P_PTHREADS) && !defined(P_THREAD_SAFE_CLIB) ) || (defined(__NUCLEUS_PLUS__) ) )
      // this function should really be a static on PIPSocket, but this would
      // require allocating thread-local storage for the data and that's too much
      // of a pain!


#ifndef P_AIX	// that I get no warnings
      int localErrNo;
      char buffer[REENTRANT_BUFFER_LEN];
      struct hostent hostEnt;
#endif

#ifdef P_LINUX
      ::gethostbyname_r(name,
                        &hostEnt,
                        buffer, REENTRANT_BUFFER_LEN,
                        &host_info,
      		        &localErrNo);
      		      		        
      		        
#elif defined P_AIX
      ::gethostbyname_r(name,
                        &host_info,
                        &ht_data);		    
#else
      host_info = ::gethostbyname_r(name,
			 &hostEnt, buffer, REENTRANT_BUFFER_LEN,
			 &localErrNo);
#endif

#else
      host_info = ::gethostbyname(name);
#endif
    } while (h_errno == TRY_AGAIN && --retry > 0);

    mutex.Wait();

    if (retry == 0)
      return NULL;

#ifdef P_AIX
    host = new PIPCacheData (&host_info, (const char*) name);
#else
    host = new PIPCacheData(host_info, name);
#endif

    SetAt(key, host);