sunrpc/rtime.c

   1 #if defined(LIBC_SCCS) && !defined(lint)
   2 static char sccsid[] = "@(#)rtime.c     2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
   3 #endif
   4 /*
   5  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   6  * unrestricted use provided that this legend is included on all tape
   7  * media and as a part of the software program in whole or part.  Users
   8  * may copy or modify Sun RPC without charge, but are not authorized
   9  * to license or distribute it to anyone else except as part of a product or
  10  * program developed by the user.
  11  *
  12  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  13  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  14  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  15  *
  16  * Sun RPC is provided with no support and without any obligation on the
  17  * part of Sun Microsystems, Inc. to assist in its use, correction,
  18  * modification or enhancement.
  19  *
  20  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  21  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  22  * OR ANY PART THEREOF.
  23  *
  24  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  25  * or profits or other special, indirect and consequential damages, even if
  26  * Sun has been advised of the possibility of such damages.
  27  *
  28  * Sun Microsystems, Inc.
  29  * 2550 Garcia Avenue
  30  * Mountain View, California  94043
  31  */
  32
  33 /*
  34  * Copyright (c) 1988 by Sun Microsystems, Inc.
  35  */
  36 /*
  37  * rtime - get time from remote machine
  38  *
  39  * gets time, obtaining value from host
  40  * on the udp/time socket.  Since timeserver returns
  41  * with time of day in seconds since Jan 1, 1900,  must
  42  * subtract seconds before Jan 1, 1970 to get
  43  * what unix uses.
  44  */
  45 #include <stdio.h>
  46 #include <unistd.h>
  47 #include <rpc/rpc.h>
  48 #include <rpc/clnt.h>
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <sys/time.h>
  52 #include <rpc/auth_des.h>
  53 #include <errno.h>
  54 #include <netinet/in.h>
  55
  56 #define NYEARS  (u_long)(1970 - 1900)
  57 #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  58
  59 static void do_close (int);
  60
  61 static void
  62 do_close (int s)
  63 {
  64   int save;
  65
  66   save = errno;
  67   close (s);
  68   __set_errno (save);
  69 }
  70
  71 int
  72 rtime (struct sockaddr_in *addrp, struct timeval *timep,
  73        struct timeval *timeout)
  74 {
  75   int s;
  76   fd_set readfds;
  77   int res;
  78   unsigned long thetime;
  79   struct sockaddr_in from;
  80   int fromlen;
  81   int type;
  82
  83   if (timeout == NULL)
  84     type = SOCK_STREAM;
  85   else
  86     type = SOCK_DGRAM;
  87
  88   s = socket (AF_INET, type, 0);
  89   if (s < 0)
  90     return (-1);
  91
  92   addrp->sin_family = AF_INET;
  93   addrp->sin_port = htons (IPPORT_TIMESERVER);
  94   if (type == SOCK_DGRAM)
  95     {
  96       res = sendto (s, (char *) &thetime, sizeof (thetime), 0,
  97                     (struct sockaddr *) addrp, sizeof (*addrp));
  98       if (res < 0)
  99         {
 100           do_close (s);
 101           return -1;
 102         }
 103       do
 104         {
 105           FD_ZERO (&readfds);
 106           FD_SET (s, &readfds);
 107           res = select (_rpc_dtablesize (), &readfds, (void *) NULL,
 108                         (void *) NULL, timeout);
 109         }
 110       while (res < 0 && errno == EINTR);
 111       if (res <= 0)
 112         {
 113           if (res == 0)
 114             __set_errno (ETIMEDOUT);
 115           do_close (s);
 116           return (-1);
 117         }
 118       fromlen = sizeof (from);
 119       res = recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
 120                       (struct sockaddr *) &from, &fromlen);
 121       do_close (s);
 122       if (res < 0)
 123         return -1;
 124     }
 125   else
 126     {
 127       if (connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
 128         {
 129           do_close (s);
 130           return -1;
 131         }
 132       res = read (s, (char *) &thetime, sizeof (thetime));
 133       do_close (s);
 134       if (res < 0)
 135         return (-1);
 136     }
 137   if (res != sizeof (thetime))
 138     {
 139       __set_errno (EIO);
 140       return -1;
 141     }
 142   thetime = ntohl (thetime);
 143   timep->tv_sec = thetime - TOFFSET;
 144   timep->tv_usec = 0;
 145   return 0;
 146 }