xref: /netbsd-src/lib/libresolv/ns_date.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: ns_date.c,v 1.1 2012/11/15 18:48:48 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5  * Copyright (c) 1999 by Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/cdefs.h>
21 #if 0
22 static const char rcsid[] = "Id: ns_date.c,v 1.6 2005/04/27 04:56:39 sra Exp ";
23 #else
24 __RCSID("$NetBSD: ns_date.c,v 1.1 2012/11/15 18:48:48 christos Exp $");
25 #endif
26 
27 /* Import. */
28 
29 #include "port_before.h"
30 
31 #include <arpa/nameser.h>
32 
33 #include <ctype.h>
34 #include <errno.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <time.h>
38 
39 #include "port_after.h"
40 
41 #ifdef SPRINTF_CHAR
42 # define SPRINTF(x) strlen(sprintf/**/x)
43 #else
44 # define SPRINTF(x) ((size_t)sprintf x)
45 #endif
46 
47 /* Forward. */
48 
49 static int	datepart(const char *, int, int, int, int *);
50 
51 /* Public. */
52 
53 /*%
54  * Convert a date in ASCII into the number of seconds since
55  * 1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
56  * digits required, no spaces allowed.
57  */
58 
59 u_int32_t
60 ns_datetosecs(const char *cp, int *errp) {
61 	struct tm tim;
62 	u_int32_t result;
63 	int mdays, i;
64 	static const int days_per_month[12] =
65 		{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
66 
67 	if (strlen(cp) != 14U) {
68 		*errp = 1;
69 		return (0);
70 	}
71 	*errp = 0;
72 
73 	memset(&tim, 0, sizeof tim);
74 	tim.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
75 	tim.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
76 	tim.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
77 	tim.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
78 	tim.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
79 	tim.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
80 	if (*errp)		/*%< Any parse errors? */
81 		return (0);
82 
83 	/*
84 	 * OK, now because timegm() is not available in all environments,
85 	 * we will do it by hand.  Roll up sleeves, curse the gods, begin!
86 	 */
87 
88 #define SECS_PER_DAY    ((u_int32_t)24*60*60)
89 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
90 
91 	result  = tim.tm_sec;				/*%< Seconds */
92 	result += tim.tm_min * 60;			/*%< Minutes */
93 	result += tim.tm_hour * (60*60);		/*%< Hours */
94 	result += (tim.tm_mday - 1) * SECS_PER_DAY;	/*%< Days */
95 	/* Months are trickier.  Look without leaping, then leap */
96 	mdays = 0;
97 	for (i = 0; i < tim.tm_mon; i++)
98 		mdays += days_per_month[i];
99 	result += mdays * SECS_PER_DAY;			/*%< Months */
100 	if (tim.tm_mon > 1 && isleap(1900+tim.tm_year))
101 		result += SECS_PER_DAY;		/*%< Add leapday for this year */
102 	/* First figure years without leapdays, then add them in.  */
103 	/* The loop is slow, FIXME, but simple and accurate.  */
104 	result += (tim.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
105 	for (i = 70; i < tim.tm_year; i++)
106 		if (isleap(1900+i))
107 			result += SECS_PER_DAY; /*%< Add leapday for prev year */
108 	return (result);
109 }
110 
111 /* Private. */
112 
113 /*%
114  * Parse part of a date.  Set error flag if any error.
115  * Don't reset the flag if there is no error.
116  */
117 static int
118 datepart(const char *buf, int size, int min, int max, int *errp) {
119 	int result = 0;
120 	int i;
121 
122 	for (i = 0; i < size; i++) {
123 		if (!isdigit((unsigned char)(buf[i])))
124 			*errp = 1;
125 		result = (result * 10) + buf[i] - '0';
126 	}
127 	if (result < min)
128 		*errp = 1;
129 	if (result > max)
130 		*errp = 1;
131 	return (result);
132 }
133 
134 /*! \file */
135