sunrpc/rtime.c

   1 /*
   2  * Copyright (c) 2010, Oracle America, Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  *       notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  *       copyright notice, this list of conditions and the following
  12  *       disclaimer in the documentation and/or other materials
  13  *       provided with the distribution.
  14  *     * Neither the name of the "Oracle America, Inc." nor the names of its
  15  *       contributors may be used to endorse or promote products derived
  16  *       from this software without specific prior written permission.
  17  *
  18  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  22  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  23  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  25  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 /*
  32  * rtime - get time from remote machine
  33  *
  34  * gets time, obtaining value from host
  35  * on the udp/time socket.  Since timeserver returns
  36  * with time of day in seconds since Jan 1, 1900,  must
  37  * subtract seconds before Jan 1, 1970 to get
  38  * what unix uses.
  39  */
  40 #include <stdio.h>
  41 #include <unistd.h>
  42 #include <stdint.h>
  43 #include <rpc/rpc.h>
  44 #include <rpc/clnt.h>
  45 #include <sys/types.h>
  46 #include <sys/poll.h>
  47 #include <sys/socket.h>
  48 #include <sys/time.h>
  49 #include <rpc/auth_des.h>
  50 #include <errno.h>
  51 #include <netinet/in.h>
  52
  53 #define NYEARS  (u_long)(1970 - 1900)
  54 #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  55
  56 static void do_close (int);
  57
  58 static void
  59 do_close (int s)
  60 {
  61   int save;
  62
  63   save = errno;
  64   __close (s);
  65   __set_errno (save);
  66 }
  67
  68 int
  69 rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
  70        struct rpc_timeval *timeout)
  71 {
  72   int s;
  73   struct pollfd fd;
  74   int milliseconds;
  75   int res;
  76   /* RFC 868 says the time is transmitted as a 32-bit value.  */
  77   uint32_t thetime;
  78   struct sockaddr_in from;
  79   socklen_t fromlen;
  80   int type;
  81
  82   if (timeout == NULL)
  83     type = SOCK_STREAM;
  84   else
  85     type = SOCK_DGRAM;
  86
  87   s = __socket (AF_INET, type, 0);
  88   if (s < 0)
  89     return (-1);
  90
  91   addrp->sin_family = AF_INET;
  92   addrp->sin_port = htons (IPPORT_TIMESERVER);
  93   if (type == SOCK_DGRAM)
  94     {
  95       res = __sendto (s, (char *) &thetime, sizeof (thetime), 0,
  96                       (struct sockaddr *) addrp, sizeof (*addrp));
  97       if (res < 0)
  98         {
  99           do_close (s);
 100           return -1;
 101         }
 102       milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
 103       fd.fd = s;
 104       fd.events = POLLIN;
 105       do
 106         res = __poll (&fd, 1, milliseconds);
 107       while (res < 0 && errno == EINTR);
 108       if (res <= 0)
 109         {
 110           if (res == 0)
 111             __set_errno (ETIMEDOUT);
 112           do_close (s);
 113           return (-1);
 114         }
 115       fromlen = sizeof (from);
 116       res = __recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
 117                         (struct sockaddr *) &from, &fromlen);
 118       do_close (s);
 119       if (res < 0)
 120         return -1;
 121     }
 122   else
 123     {
 124       if (__connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
 125         {
 126           do_close (s);
 127           return -1;
 128         }
 129       res = __read (s, (char *) &thetime, sizeof (thetime));
 130       do_close (s);
 131       if (res < 0)
 132         return (-1);
 133     }
 134   if (res != sizeof (thetime))
 135     {
 136       __set_errno (EIO);
 137       return -1;
 138     }
 139   thetime = ntohl (thetime);
 140   timep->tv_sec = thetime - TOFFSET;
 141   timep->tv_usec = 0;
 142   return 0;
 143 }
 144 libc_hidden_nolink_sunrpc (rtime, GLIBC_2_1)