/*

 * Copyright (c) 2010, Oracle America, Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are

 * met:

 *

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above

 *       copyright notice, this list of conditions and the following

 *       disclaimer in the documentation and/or other materials

 *       provided with the distribution.

 *     * Neither the name of the "Oracle America, Inc." nor the names of its

 *       contributors may be used to endorse or promote products derived

 *       from this software without specific prior written permission.

 *

 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * rtime - get time from remote machine

 *

 * gets time, obtaining value from host

 * on the udp/time socket.  Since timeserver returns

 * with time of day in seconds since Jan 1, 1900,  must

 * subtract seconds before Jan 1, 1970 to get

 * what unix uses.

 */

#include <stdio.h>

#include <unistd.h>

#include <stdint.h>

#include <rpc/rpc.h>

#include <rpc/clnt.h>

#include <sys/types.h>

#include <sys/poll.h>

#include <sys/socket.h>

#include <sys/time.h>

#include <rpc/auth_des.h>

#include <errno.h>

#include <netinet/in.h>

#include <shlib-compat.h>

#define NYEARS	(u_long)(1970 - 1900)

#define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))

static void do_close (int);

static void

do_close (int s)

{

  int save;

  save = errno;

  __close (s);

  __set_errno (save);

}

int

rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,

       struct rpc_timeval *timeout)

{

  int s;

  struct pollfd fd;

  int milliseconds;

  int res;

  /* RFC 868 says the time is transmitted as a 32-bit value.  */

  uint32_t thetime;

  struct sockaddr_in from;

  socklen_t fromlen;

  int type;

  if (timeout == NULL)

    type = SOCK_STREAM;

  else

    type = SOCK_DGRAM;

  s = __socket (AF_INET, type, 0);

  if (s < 0)

    return (-1);

  addrp->sin_family = AF_INET;

  addrp->sin_port = htons (IPPORT_TIMESERVER);

  if (type == SOCK_DGRAM)

    {

      res = __sendto (s, (char *) &thetime, sizeof (thetime), 0,

		      (struct sockaddr *) addrp, sizeof (*addrp));

      if (res < 0)

	{

	  do_close (s);

	  return -1;

	}

      milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);

      fd.fd = s;

      fd.events = POLLIN;

      do

	res = __poll (&fd, 1, milliseconds);

      while (res < 0 && errno == EINTR);

      if (res <= 0)

	{

	  if (res == 0)

	    __set_errno (ETIMEDOUT);

	  do_close (s);

	  return (-1);

	}

      fromlen = sizeof (from);

      res = __recvfrom (s, (char *) &thetime, sizeof (thetime), 0,

			(struct sockaddr *) &from, &fromlen);

      do_close (s);

      if (res < 0)

	return -1;

    }

  else

    {

      if (__connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)

	{

	  do_close (s);

	  return -1;

	}

      res = __read (s, (char *) &thetime, sizeof (thetime));

      do_close (s);

      if (res < 0)

	return (-1);

    }

  if (res != sizeof (thetime))

    {

      __set_errno (EIO);

      return -1;

    }

  thetime = ntohl (thetime);

  timep->tv_sec = thetime - TOFFSET;

  timep->tv_usec = 0;

  return 0;

}

libc_hidden_nolink_sunrpc (rtime, GLIBC_2_1)