thread.c

一个开源的VPN原码

/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single UDP port, with support for TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002 James Yonan <[e-mail]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#ifdef USE_PTHREAD

#include "syshead.h"

#include "thread.h"
#include "buffer.h"
#include "common.h"
#include "error.h"
#include "crypto.h"

#include "memdbg.h"

#if defined(USE_CRYPTO) && defined(USE_SSL)

static pthread_mutex_t *ssl_lock_cs;
static long *ssl_lock_count;

static void
ssl_pthreads_locking_callback (int mode, int type, char *file, int line)
{
  msg (D_OPENSSL_LOCK, "SSL LOCK thread=%4d mode=%s lock=%s %s:%d",
	   CRYPTO_thread_id (),
	   (mode & CRYPTO_LOCK) ? "l" : "u",
	   (type & CRYPTO_READ) ? "r" : "w", file, line);

  if (mode & CRYPTO_LOCK)
    {
      pthread_mutex_lock (&(ssl_lock_cs[type]));
      ssl_lock_count[type]++;
    }
  else
    {
      pthread_mutex_unlock (&(ssl_lock_cs[type]));
    }
}

static unsigned long
ssl_pthreads_thread_id (void)
{
  unsigned long ret;

  ret = (unsigned long) pthread_self ();
  return ret;
}

static void
ssl_thread_setup (void)
{
  int i;

  ssl_lock_cs = OPENSSL_malloc (CRYPTO_num_locks () * sizeof (pthread_mutex_t));
  ssl_lock_count = OPENSSL_malloc (CRYPTO_num_locks () * sizeof (long));
  for (i = 0; i < CRYPTO_num_locks (); i++)
    {
      ssl_lock_count[i] = 0;
      pthread_mutex_init (&(ssl_lock_cs[i]), NULL);
    }

  CRYPTO_set_id_callback ((unsigned long (*)()) ssl_pthreads_thread_id);
  CRYPTO_set_locking_callback ((void (*)()) ssl_pthreads_locking_callback);
}

static void
ssl_thread_cleanup (void)
{
  int i;

  msg (D_OPENSSL_LOCK, "SSL LOCK cleanup");
  CRYPTO_set_locking_callback (NULL);
  for (i = 0; i < CRYPTO_num_locks (); i++)
    pthread_mutex_destroy (&(ssl_lock_cs[i]));
  OPENSSL_free (ssl_lock_cs);
  OPENSSL_free (ssl_lock_count);
}

#endif /* defined(USE_CRYPTO) && defined(USE_SSL) */

pthread_t _main_thread_id;
pthread_t _work_thread_id;
pthread_mutex_t _lock_cs[N_MUTEXES];
bool _lock_cs_init;

void
work_thread_create (void *(*start_routine) (void *), void* arg)
{
  ASSERT (_main_thread_id);
  ASSERT (!_work_thread_id);
  ASSERT (!pthread_create (&_work_thread_id, NULL, start_routine, arg));
  msg (D_THREAD_DEBUG, "CREATE THREAD ID=%d", _work_thread_id);
}

void
work_thread_join ()
{
  if (_work_thread_id)
    {
      pthread_join (_work_thread_id, NULL);
      _work_thread_id = 0;
    }
}

void
thread_init ()
{
  int i;

  ASSERT (!_main_thread_id);
  ASSERT (!_work_thread_id);

  msg (M_INFO, "PTHREAD support initialized");

  _main_thread_id = pthread_self ();

  /* initialize OpenSSL library locking */
#if defined(USE_CRYPTO) && defined(USE_SSL)
  ssl_thread_setup();
#endif
  
  /* initialize static mutexes */
  ASSERT (!_lock_cs_init);
  for (i = 0; i < N_MUTEXES; i++)
    ASSERT (!pthread_mutex_init (&(_lock_cs[i]), NULL));
  _lock_cs_init = true;
}

void
thread_cleanup ()
{
  ASSERT (!_work_thread_id);
  if (_main_thread_id)
    {
      int i;

      /* cleanup OpenSSL library locking */
#if defined(USE_CRYPTO) && defined(USE_SSL)
      ssl_thread_cleanup();
#endif

      /* destroy static mutexes */
      if (_lock_cs_init)
	{
	  _lock_cs_init = false;
	  for (i = 0; i < N_MUTEXES; i++)
	    ASSERT (!pthread_mutex_destroy (&(_lock_cs[i])));
	}

      _main_thread_id = 0;
    }
}

#endif