sysdeps/unix/sysv/linux/adjtime.c

   1 /* Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   2
   3 The GNU C Library is free software; you can redistribute it and/or
   4 modify it under the terms of the GNU Library General Public License as
   5 published by the Free Software Foundation; either version 2 of the
   6 License, or (at your option) any later version.
   7
   8 The GNU C Library is distributed in the hope that it will be useful,
   9 but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 Library General Public License for more details.
  12
  13 You should have received a copy of the GNU Library General Public
  14 License along with the GNU C Library; see the file COPYING.LIB.  If
  15 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 Boston, MA 02111-1307, USA.  */
  17
  18 #include <errno.h>
  19 #include <limits.h>
  20 #include <sys/time.h>
  21 #include <sys/timex.h>
  22
  23 #define MAX_SEC (INT_MAX / 1000000L - 2)
  24 #define MIN_SEC (INT_MIN / 1000000L + 2)
  25
  26 #ifndef MOD_OFFSET
  27 #define modes mode
  28 #endif
  29
  30 int
  31 __adjtime (itv, otv)
  32      const struct timeval *itv;
  33      struct timeval *otv;
  34 {
  35   struct timex tntx;
  36
  37   if (itv)
  38     {
  39       struct timeval tmp;
  40
  41       /* We will do some check here. */
  42       tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
  43       tmp.tv_usec = itv->tv_usec % 1000000L;
  44       if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
  45         {
  46           __set_errno (EINVAL);
  47           return -1;
  48         }
  49       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
  50       tntx.modes = ADJ_OFFSET_SINGLESHOT;
  51     }
  52   else
  53     tntx.modes = 0;
  54
  55   if (__adjtimex (&tntx) < 0) return -1;
  56
  57   if (otv)
  58     {
  59       if (tntx.offset < 0)
  60         {
  61           otv->tv_usec = -(-tntx.offset % 1000000);
  62           otv->tv_sec  = -(-tntx.offset / 1000000);
  63         }
  64       else
  65         {
  66           otv->tv_usec = tntx.offset % 1000000;
  67           otv->tv_sec  = tntx.offset / 1000000;
  68         }
  69     }
  70   return 0;
  71 }
  72
  73 weak_alias (__adjtime, adjtime)