sysdeps/unix/sysv/linux/adjtime.c

   1 /* Copyright (C) 1995-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  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 #ifndef TIMEVAL
  31 #define TIMEVAL timeval
  32 #endif
  33
  34 #ifndef TIMEX
  35 #define TIMEX timex
  36 #endif
  37
  38 #ifndef ADJTIME
  39 #define ADJTIME __adjtime
  40 #endif
  41
  42 #ifndef ADJTIMEX
  43 #define NO_LOCAL_ADJTIME
  44 #define ADJTIMEX(x) INTUSE(__adjtimex) (x)
  45 extern int INTUSE(__adjtimex) (struct timex *__ntx);
  46 #endif
  47
  48 #ifndef LINKAGE
  49 #define LINKAGE
  50 #endif
  51
  52 LINKAGE int
  53 ADJTIME (const struct TIMEVAL *itv, struct TIMEVAL *otv)
  54 {
  55   struct TIMEX tntx;
  56
  57   if (itv)
  58     {
  59       struct TIMEVAL tmp;
  60
  61       /* We will do some check here. */
  62       tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
  63       tmp.tv_usec = itv->tv_usec % 1000000L;
  64       if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
  65         {
  66           __set_errno (EINVAL);
  67           return -1;
  68         }
  69       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
  70       tntx.modes = ADJ_OFFSET_SINGLESHOT;
  71     }
  72   else
  73     tntx.modes = ADJ_OFFSET_SS_READ;
  74
  75   if (__glibc_unlikely (ADJTIMEX (&tntx) < 0))
  76     return -1;
  77
  78   if (otv)
  79     {
  80       if (tntx.offset < 0)
  81         {
  82           otv->tv_usec = -(-tntx.offset % 1000000);
  83           otv->tv_sec  = -(-tntx.offset / 1000000);
  84         }
  85       else
  86         {
  87           otv->tv_usec = tntx.offset % 1000000;
  88           otv->tv_sec  = tntx.offset / 1000000;
  89         }
  90     }
  91   return 0;
  92 }
  93
  94 #ifdef NO_LOCAL_ADJTIME
  95 weak_alias (__adjtime, adjtime)
  96 #endif