sysdeps/unix/sysv/linux/adjtime.c

   1 /* Copyright (C) 1995, 1996, 1997, 1998, 2002, 2004, 2007, 2008
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <limits.h>
  21 #include <sys/time.h>
  22 #include <sys/timex.h>
  23
  24 #include <kernel-features.h>
  25
  26 #define MAX_SEC (INT_MAX / 1000000L - 2)
  27 #define MIN_SEC (INT_MIN / 1000000L + 2)
  28
  29 #ifndef MOD_OFFSET
  30 #define modes mode
  31 #endif
  32
  33 #ifndef TIMEVAL
  34 #define TIMEVAL timeval
  35 #endif
  36
  37 #ifndef TIMEX
  38 #define TIMEX timex
  39 #endif
  40
  41 #ifndef ADJTIME
  42 #define ADJTIME __adjtime
  43 #endif
  44
  45 #ifndef ADJTIMEX
  46 #define NO_LOCAL_ADJTIME
  47 #define ADJTIMEX(x) INTUSE(__adjtimex) (x)
  48 extern int INTUSE(__adjtimex) (struct timex *__ntx);
  49 #endif
  50
  51 #ifndef LINKAGE
  52 #define LINKAGE
  53 #endif
  54
  55 LINKAGE int
  56 ADJTIME (const struct TIMEVAL *itv, struct TIMEVAL *otv)
  57 {
  58   struct TIMEX tntx;
  59
  60   if (itv)
  61     {
  62       struct TIMEVAL tmp;
  63
  64       /* We will do some check here. */
  65       tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
  66       tmp.tv_usec = itv->tv_usec % 1000000L;
  67       if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
  68         {
  69           __set_errno (EINVAL);
  70           return -1;
  71         }
  72       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
  73       tntx.modes = ADJ_OFFSET_SINGLESHOT;
  74     }
  75   else
  76     {
  77 #ifdef ADJ_OFFSET_SS_READ
  78       tntx.modes = ADJ_OFFSET_SS_READ;
  79 #else
  80       tntx.modes = 0;
  81 #endif
  82     }
  83
  84 #if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
  85  again:
  86 #endif
  87   if (__builtin_expect (ADJTIMEX (&tntx) < 0, 0))
  88     {
  89 #if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
  90       if (itv && errno == EINVAL && tntx.modes == ADJ_OFFSET_SS_READ)
  91         {
  92           tntx.modes = ADJ_OFFSET_SINGLESHOT;
  93           goto again;
  94         }
  95 #endif
  96       return -1;
  97     }
  98
  99   if (otv)
 100     {
 101       if (tntx.offset < 0)
 102         {
 103           otv->tv_usec = -(-tntx.offset % 1000000);
 104           otv->tv_sec  = -(-tntx.offset / 1000000);
 105         }
 106       else
 107         {
 108           otv->tv_usec = tntx.offset % 1000000;
 109           otv->tv_sec  = tntx.offset / 1000000;
 110         }
 111     }
 112   return 0;
 113 }
 114
 115 #ifdef NO_LOCAL_ADJTIME
 116 weak_alias (__adjtime, adjtime)
 117 #endif