1/*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1999-2003 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 *   Internet Systems Consortium, Inc.
18 *   950 Charter Street
19 *   Redwood City, CA 94063
20 *   <info@isc.org>
21 *   http://www.isc.org/
22 */
23
24#ifndef lint
25static const char rcsid[] = "$Id: ns_date.c,v 1.3 2005/08/11 17:13:26 drochner Exp $";
26#endif
27
28/* Import. */
29
30#include <ctype.h>
31#include <errno.h>
32#include <stdio.h>
33#include <string.h>
34#include <time.h>
35
36#include <sys/types.h>
37#include <netinet/in.h>
38#include <sys/socket.h>
39
40#include "minires/minires.h"
41#include "arpa/nameser.h"
42
43#ifdef SPRINTF_CHAR
44# define SPRINTF(x) strlen(sprintf/**/x)
45#else
46# define SPRINTF(x) ((size_t)sprintf x)
47#endif
48
49/* Forward. */
50
51static int	datepart(const char *, int, int, int, int *);
52
53/* Public. */
54
55/* Convert a date in ASCII into the number of seconds since
56   1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
57   digits required, no spaces allowed.  */
58
59u_int32_t
60ns_datetosecs(const char *cp, int *errp) {
61	struct tm time;
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) != 14) {
68		*errp = 1;
69		return (0);
70	}
71	*errp = 0;
72
73	memset(&time, 0, sizeof time);
74	time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
75	time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
76	time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
77	time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
78	time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
79	time.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  = time.tm_sec;				/* Seconds */
92	result += time.tm_min * 60;			/* Minutes */
93	result += time.tm_hour * (60*60);		/* Hours */
94	result += (time.tm_mday - 1) * SECS_PER_DAY;	/* Days */
95
96	/* Months are trickier.  Look without leaping, then leap */
97	mdays = 0;
98	for (i = 0; i < time.tm_mon; i++)
99		mdays += days_per_month[i];
100	result += mdays * SECS_PER_DAY;			/* Months */
101	if (time.tm_mon > 1 && isleap(1900+time.tm_year))
102		result += SECS_PER_DAY;		/* Add leapday for this year */
103
104	/* First figure years without leapdays, then add them in.  */
105	/* The loop is slow, FIXME, but simple and accurate.  */
106	result += (time.tm_year - 70) * (SECS_PER_DAY*365); /* Years */
107	for (i = 70; i < time.tm_year; i++)
108		if (isleap(1900+i))
109			result += SECS_PER_DAY; /* Add leapday for prev year */
110
111	return (result);
112}
113
114/* Private. */
115
116/*
117 * Parse part of a date.  Set error flag if any error.
118 * Don't reset the flag if there is no error.
119 */
120static int
121datepart(const char *buf, int size, int min, int max, int *errp) {
122	int result = 0;
123	int i;
124
125	for (i = 0; i < size; i++) {
126		if (!isdigit((unsigned char)buf[i]))
127			*errp = 1;
128		result = (result * 10) + buf[i] - '0';
129	}
130	if (result < min)
131		*errp = 1;
132	if (result > max)
133		*errp = 1;
134	return (result);
135}
136