rtime.c

   1 #if 0
   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
  46 #define __FORCE_GLIBC
  47 #include <features.h>
  48
  49 #include <stdio.h>
  50 #include <unistd.h>
  51 #include <rpc/rpc.h>
  52 #include <rpc/clnt.h>
  53 #include <sys/types.h>
  54 #include <poll.h>
  55 #include <sys/socket.h>
  56 #include <sys/time.h>
  57 #include <rpc/auth_des.h>
  58 #include <errno.h>
  59 #include <netinet/in.h>
  60
  61 #ifndef IPPORT_TIMESERVER
  62 #define IPPORT_TIMESERVER 37
  63 #endif
  64
  65 #define NYEARS  (u_long)(1970 - 1900)
  66 #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  67
  68 static void do_close (int);
  69
  70 static void
  71 do_close (int s)
  72 {
  73   int save;
  74
  75   save = errno;
  76   close (s);
  77   __set_errno (save);
  78 }
  79
  80 int
  81 rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
  82        struct rpc_timeval *timeout)
  83 {
  84   int s;
  85   struct pollfd fd;
  86   int milliseconds;
  87   int res;
  88   /* RFC 868 says the time is transmitted as a 32-bit value.  */
  89   uint32_t thetime;
  90   struct sockaddr_in from;
  91   socklen_t fromlen;
  92   int type;
  93
  94   if (timeout == NULL)
  95     type = SOCK_STREAM;
  96   else
  97     type = SOCK_DGRAM;
  98
  99   s = socket (AF_INET, type, 0);
 100   if (s < 0)
 101     return (-1);
 102
 103   addrp->sin_family = AF_INET;
 104   addrp->sin_port = htons (IPPORT_TIMESERVER);
 105   if (type == SOCK_DGRAM)
 106     {
 107       res = sendto (s, (char *) &thetime, sizeof (thetime), 0,
 108                       (struct sockaddr *) addrp, sizeof (*addrp));
 109       if (res < 0)
 110         {
 111           do_close (s);
 112           return -1;
 113         }
 114       milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
 115       fd.fd = s;
 116       fd.events = POLLIN;
 117       do
 118         res = poll (&fd, 1, milliseconds);
 119       while (res < 0 && errno == EINTR);
 120       if (res <= 0)
 121         {
 122           if (res == 0)
 123             __set_errno (ETIMEDOUT);
 124           do_close (s);
 125           return (-1);
 126         }
 127       fromlen = sizeof (from);
 128       res = recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
 129                         (struct sockaddr *) &from, &fromlen);
 130       do_close (s);
 131       if (res < 0)
 132         return -1;
 133     }
 134   else
 135     {
 136       if (connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
 137         {
 138           do_close (s);
 139           return -1;
 140         }
 141       res = read (s, (char *) &thetime, sizeof (thetime));
 142       do_close (s);
 143       if (res < 0)
 144         return (-1);
 145     }
 146   if (res != sizeof (thetime))
 147     {
 148       __set_errno (EIO);
 149       return -1;
 150     }
 151   thetime = ntohl (thetime);
 152   timep->tv_sec = thetime - TOFFSET;
 153   timep->tv_usec = 0;
 154   return 0;
 155 }
 156 libc_hidden_def (rtime)