crypto/external/bsd/heimdal/dist/lib/roken/timegm.c

   1 /*      $NetBSD: timegm.c,v 1.1.1.1 2011/04/13 18:15:43 elric Exp $     */
   2
   3 /*
   4  * Copyright (c) 1997, 2006 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #include <krb5/roken.h>
  39
  40 static int
  41 is_leap(unsigned y)
  42 {
  43     y += 1900;
  44     return (y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0);
  45 }
  46
  47 /*
  48  * XXX This is a simplifed version of timegm, it needs to support out of
  49  * bounds values.
  50  */
  51
  52 time_t
  53 rk_timegm (struct tm *tm)
  54 {
  55   static const unsigned ndays[2][12] ={
  56     {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
  57     {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
  58   time_t res = 0;
  59   unsigned i;
  60
  61   if (tm->tm_year < 0)
  62       return -1;
  63   if (tm->tm_mon < 0 || tm->tm_mon > 11)
  64       return -1;
  65   if (tm->tm_mday < 1 || tm->tm_mday > ndays[is_leap(tm->tm_year)][tm->tm_mon])
  66       return -1;
  67   if (tm->tm_hour < 0 || tm->tm_hour > 23)
  68       return -1;
  69   if (tm->tm_min < 0 || tm->tm_min > 59)
  70       return -1;
  71   if (tm->tm_sec < 0 || tm->tm_sec > 59)
  72       return -1;
  73
  74   for (i = 70; i < tm->tm_year; ++i)
  75     res += is_leap(i) ? 366 : 365;
  76
  77   for (i = 0; i < tm->tm_mon; ++i)
  78     res += ndays[is_leap(tm->tm_year)][i];
  79   res += tm->tm_mday - 1;
  80   res *= 24;
  81   res += tm->tm_hour;
  82   res *= 60;
  83   res += tm->tm_min;
  84   res *= 60;
  85   res += tm->tm_sec;
  86   return res;
  87 }