sysdeps/unix/sysv/linux/adjtime.c

   1 /* Copyright (C) 1995, 1996, 1997, 1998, 2002, 2004, 2007
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <sys/time.h>
  23 #include <sys/timex.h>
  24
  25 #include <kernel-features.h>
  26
  27 #define MAX_SEC (INT_MAX / 1000000L - 2)
  28 #define MIN_SEC (INT_MIN / 1000000L + 2)
  29
  30 #ifndef MOD_OFFSET
  31 #define modes mode
  32 #endif
  33
  34 #ifndef TIMEVAL
  35 #define TIMEVAL timeval
  36 #endif
  37
  38 #ifndef TIMEX
  39 #define TIMEX timex
  40 #endif
  41
  42 #ifndef ADJTIME
  43 #define ADJTIME __adjtime
  44 #endif
  45
  46 #ifndef ADJTIMEX
  47 #define NO_LOCAL_ADJTIME
  48 #define ADJTIMEX(x) INTUSE(__adjtimex) (x)
  49 extern int INTUSE(__adjtimex) (struct timex *__ntx);
  50 #endif
  51
  52 #ifndef LINKAGE
  53 #define LINKAGE
  54 #endif
  55
  56 LINKAGE int
  57 ADJTIME (const struct TIMEVAL *itv, struct TIMEVAL *otv)
  58 {
  59   struct TIMEX tntx;
  60
  61   if (itv)
  62     {
  63       struct TIMEVAL tmp;
  64
  65       /* We will do some check here. */
  66       tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
  67       tmp.tv_usec = itv->tv_usec % 1000000L;
  68       if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
  69         {
  70           __set_errno (EINVAL);
  71           return -1;
  72         }
  73       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
  74 #ifdef ADJ_OFFSET_SS_READ
  75       tntx.modes = ADJ_OFFSET_SS_READ;
  76 #else
  77       tntx.modes = ADJ_OFFSET_SINGLESHOT;
  78 #endif
  79     }
  80   else
  81     tntx.modes = 0;
  82
  83 #if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
  84  again:
  85 #endif
  86   if (__builtin_expect (ADJTIMEX (&tntx) < 0, 0))
  87     {
  88 #if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
  89       if (itv && errno == EINVAL && tntx.modes == ADJ_OFFSET_SS_READ)
  90         {
  91           tntx.modes = ADJ_OFFSET_SINGLESHOT;
  92           goto again;
  93         }
  94 #endif
  95       return -1;
  96     }
  97
  98   if (otv)
  99     {
 100       if (tntx.offset < 0)
 101         {
 102           otv->tv_usec = -(-tntx.offset % 1000000);
 103           otv->tv_sec  = -(-tntx.offset / 1000000);
 104         }
 105       else
 106         {
 107           otv->tv_usec = tntx.offset % 1000000;
 108           otv->tv_sec  = tntx.offset / 1000000;
 109         }
 110     }
 111   return 0;
 112 }
 113
 114 #ifdef NO_LOCAL_ADJTIME
 115 weak_alias (__adjtime, adjtime)
 116 #endif