sysdeps/unix/sysv/linux/adjtime.c

   1 /* Copyright (C) 1995-2013 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 #include <kernel-features.h>
  24
  25 #define MAX_SEC (INT_MAX / 1000000L - 2)
  26 #define MIN_SEC (INT_MIN / 1000000L + 2)
  27
  28 #ifndef MOD_OFFSET
  29 #define modes mode
  30 #endif
  31
  32 #ifndef TIMEVAL
  33 #define TIMEVAL timeval
  34 #endif
  35
  36 #ifndef TIMEX
  37 #define TIMEX timex
  38 #endif
  39
  40 #ifndef ADJTIME
  41 #define ADJTIME __adjtime
  42 #endif
  43
  44 #ifndef ADJTIMEX
  45 #define NO_LOCAL_ADJTIME
  46 #define ADJTIMEX(x) INTUSE(__adjtimex) (x)
  47 extern int INTUSE(__adjtimex) (struct timex *__ntx);
  48 #endif
  49
  50 #ifndef LINKAGE
  51 #define LINKAGE
  52 #endif
  53
  54 LINKAGE int
  55 ADJTIME (const struct TIMEVAL *itv, struct TIMEVAL *otv)
  56 {
  57   struct TIMEX tntx;
  58
  59   if (itv)
  60     {
  61       struct TIMEVAL tmp;
  62
  63       /* We will do some check here. */
  64       tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
  65       tmp.tv_usec = itv->tv_usec % 1000000L;
  66       if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
  67         {
  68           __set_errno (EINVAL);
  69           return -1;
  70         }
  71       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
  72       tntx.modes = ADJ_OFFSET_SINGLESHOT;
  73     }
  74   else
  75     {
  76 #ifdef ADJ_OFFSET_SS_READ
  77       tntx.modes = ADJ_OFFSET_SS_READ;
  78 #else
  79       tntx.modes = 0;
  80 #endif
  81     }
  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