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 }
88