glibc/sunrpc/rtime.c

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
#endif
/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 * 
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 * 
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 * 
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 * 
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.
 */
/*
 * 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 <rpc/rpc.h>
#include <rpc/clnt.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <rpc/auth_des.h>
#include <errno.h>
#include <netinet/in.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 timeval *timep,
       struct timeval *timeout)
{
  int s;
  fd_set readfds;
  int res;
  unsigned long thetime;
  struct sockaddr_in from;
  int 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;
	}
      do
	{
	  FD_ZERO (&readfds);
	  FD_SET (s, &readfds);
	  res = select (_rpc_dtablesize (), &readfds, (void *) NULL,
			(void *) NULL, timeout);
	}
      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;
}