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