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 #include <shlib-compat.h>
  53
  54 #define NYEARS  (u_long)(1970 - 1900)
  55 #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  56
  57 static void do_close (int);
  58
  59 static void
  60 do_close (int s)
  61 {
  62   int save;
  63
  64   save = errno;
  65   __close (s);
  66   __set_errno (save);
  67 }
  68
  69 int
  70 rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
  71        struct rpc_timeval *timeout)
  72 {
  73   int s;
  74   struct pollfd fd;
  75   int milliseconds;
  76   int res;
  77   /* RFC 868 says the time is transmitted as a 32-bit value.  */
  78   uint32_t thetime;
  79   struct sockaddr_in from;
  80   socklen_t 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       milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
 104       fd.fd = s;
 105       fd.events = POLLIN;
 106       do
 107         res = __poll (&fd, 1, milliseconds);
 108       while (res < 0 && errno == EINTR);
 109       if (res <= 0)
 110         {
 111           if (res == 0)
 112             __set_errno (ETIMEDOUT);
 113           do_close (s);
 114           return (-1);
 115         }
 116       fromlen = sizeof (from);
 117       res = __recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
 118                         (struct sockaddr *) &from, &fromlen);
 119       do_close (s);
 120       if (res < 0)
 121         return -1;
 122     }
 123   else
 124     {
 125       if (__connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
 126         {
 127           do_close (s);
 128           return -1;
 129         }
 130       res = __read (s, (char *) &thetime, sizeof (thetime));
 131       do_close (s);
 132       if (res < 0)
 133         return (-1);
 134     }
 135   if (res != sizeof (thetime))
 136     {
 137       __set_errno (EIO);
 138       return -1;
 139     }
 140   thetime = ntohl (thetime);
 141   timep->tv_sec = thetime - TOFFSET;
 142   timep->tv_usec = 0;
 143   return 0;
 144 }
 145 libc_hidden_nolink_sunrpc (rtime, GLIBC_2_1)