ns_date.c revision 1.1.1.2 
1/*	$NetBSD: ns_date.c,v 1.1.1.2 2012/09/09 16:08:03 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#ifndef lint
21static const char rcsid[] = "Id: ns_date.c,v 1.6 2005/04/27 04:56:39 sra Exp ";
22#endif
23
24/* Import. */
25
26#include "port_before.h"
27
28#include <arpa/nameser.h>
29
30#include <ctype.h>
31#include <errno.h>
32#include <stdio.h>
33#include <string.h>
34#include <time.h>
35
36#include "port_after.h"
37
38#ifdef SPRINTF_CHAR
39# define SPRINTF(x) strlen(sprintf/**/x)
40#else
41# define SPRINTF(x) ((size_t)sprintf x)
42#endif
43
44/* Forward. */
45
46static int	datepart(const char *, int, int, int, int *);
47
48/* Public. */
49
50/*%
51 * Convert a date in ASCII into the number of seconds since
52 * 1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
53 * digits required, no spaces allowed.
54 */
55
56u_int32_t
57ns_datetosecs(const char *cp, int *errp) {
58	struct tm time;
59	u_int32_t result;
60	int mdays, i;
61	static const int days_per_month[12] =
62		{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
63
64	if (strlen(cp) != 14U) {
65		*errp = 1;
66		return (0);
67	}
68	*errp = 0;
69
70	memset(&time, 0, sizeof time);
71	time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
72	time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
73	time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
74	time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
75	time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
76	time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
77	if (*errp)		/*%< Any parse errors? */
78		return (0);
79
80	/*
81	 * OK, now because timegm() is not available in all environments,
82	 * we will do it by hand.  Roll up sleeves, curse the gods, begin!
83	 */
84
85#define SECS_PER_DAY    ((u_int32_t)24*60*60)
86#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
87
88	result  = time.tm_sec;				/*%< Seconds */
89	result += time.tm_min * 60;			/*%< Minutes */
90	result += time.tm_hour * (60*60);		/*%< Hours */
91	result += (time.tm_mday - 1) * SECS_PER_DAY;	/*%< Days */
92	/* Months are trickier.  Look without leaping, then leap */
93	mdays = 0;
94	for (i = 0; i < time.tm_mon; i++)
95		mdays += days_per_month[i];
96	result += mdays * SECS_PER_DAY;			/*%< Months */
97	if (time.tm_mon > 1 && isleap(1900+time.tm_year))
98		result += SECS_PER_DAY;		/*%< Add leapday for this year */
99	/* First figure years without leapdays, then add them in.  */
100	/* The loop is slow, FIXME, but simple and accurate.  */
101	result += (time.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
102	for (i = 70; i < time.tm_year; i++)
103		if (isleap(1900+i))
104			result += SECS_PER_DAY; /*%< Add leapday for prev year */
105	return (result);
106}
107
108/* Private. */
109
110/*%
111 * Parse part of a date.  Set error flag if any error.
112 * Don't reset the flag if there is no error.
113 */
114static int
115datepart(const char *buf, int size, int min, int max, int *errp) {
116	int result = 0;
117	int i;
118
119	for (i = 0; i < size; i++) {
120		if (!isdigit((unsigned char)(buf[i])))
121			*errp = 1;
122		result = (result * 10) + buf[i] - '0';
123	}
124	if (result < min)
125		*errp = 1;
126	if (result > max)
127		*errp = 1;
128	return (result);
129}
130
131/*! \file */
132