xref: /titanic_41/usr/src/lib/libresolv2/common/nameser/ns_date.c (revision c037192b037119c9fd354732fc29b38ce097d356)
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
19 static 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 
44 static 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 
54 u_int32_t
55 ns_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  */
112 static int
113 datepart(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