1 /* $NetBSD: timegm.c,v 1.2 2017/01/28 21:31:50 christos 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
is_leap(unsigned y)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
rk_timegm(struct tm * tm)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