1/*
2 * Copyright (c) 1999 by Internet Software Consortium.
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15 * SOFTWARE.
16 */
17
18#ifndef __APPLE__
19#ifndef lint
20static const char rcsid[] = "$Id: ns_date.c,v 1.1 2006/03/01 19:01:36 majka Exp $";
21#endif
22#endif
23
24/* Import. */
25
26#ifndef __APPLE__
27#include "port_before.h"
28#endif
29
30#include <arpa/nameser.h>
31
32#include <ctype.h>
33#include <errno.h>
34#include <stdio.h>
35#include <string.h>
36#include <time.h>
37
38#ifndef __APPLE__
39#include "port_after.h"
40#endif
41
42#ifdef SPRINTF_CHAR
43# define SPRINTF(x) strlen(sprintf/**/x)
44#else
45# define SPRINTF(x) ((size_t)sprintf x)
46#endif
47
48/* Forward. */
49
50static int	datepart(const char *, int, int, int, int *);
51
52/* Public. */
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
58u_int32_t
59ns_datetosecs(const char *cp, int *errp) {
60	struct tm time;
61	u_int32_t result;
62	int mdays, i;
63	static const int days_per_month[12] =
64		{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
65
66	if (strlen(cp) != 14) {
67		*errp = 1;
68		return (0);
69	}
70	*errp = 0;
71
72	memset(&time, 0, sizeof time);
73	time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
74	time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
75	time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
76	time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
77	time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
78	time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
79	if (*errp)		/* Any parse errors? */
80		return (0);
81
82	/*
83	 * OK, now because timegm() is not available in all environments,
84	 * we will do it by hand.  Roll up sleeves, curse the gods, begin!
85	 */
86
87#define SECS_PER_DAY    ((u_int32_t)24*60*60)
88#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
89
90	result  = time.tm_sec;				/* Seconds */
91	result += time.tm_min * 60;			/* Minutes */
92	result += time.tm_hour * (60*60);		/* Hours */
93	result += (time.tm_mday - 1) * SECS_PER_DAY;	/* Days */
94
95	/* Months are trickier.  Look without leaping, then leap */
96	mdays = 0;
97	for (i = 0; i < time.tm_mon; i++)
98		mdays += days_per_month[i];
99	result += mdays * SECS_PER_DAY;			/* Months */
100	if (time.tm_mon > 1 && isleap(1900+time.tm_year))
101		result += SECS_PER_DAY;		/* Add leapday for this year */
102
103	/* First figure years without leapdays, then add them in.  */
104	/* The loop is slow, FIXME, but simple and accurate.  */
105	result += (time.tm_year - 70) * (SECS_PER_DAY*365); /* Years */
106	for (i = 70; i < time.tm_year; i++)
107		if (isleap(1900+i))
108			result += SECS_PER_DAY; /* Add leapday for prev year */
109
110	return (result);
111}
112
113/* Private. */
114
115/*
116 * Parse part of a date.  Set error flag if any error.
117 * Don't reset the flag if there is no error.
118 */
119static int
120datepart(const char *buf, int size, int min, int max, int *errp) {
121	int result = 0;
122	int i;
123
124	for (i = 0; i < size; i++) {
125		if (!isdigit((unsigned char)(buf[i])))
126			*errp = 1;
127		result = (result * 10) + buf[i] - '0';
128	}
129	if (result < min)
130		*errp = 1;
131	if (result > max)
132		*errp = 1;
133	return (result);
134}
135