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 #include "port_before.h"
19 
20 #include <arpa/nameser.h>
21 
22 #include <ctype.h>
23 #include <errno.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <time.h>
27 
28 #include "port_after.h"
29 
30 #ifdef SPRINTF_CHAR
31 # define SPRINTF(x) strlen(sprintf/**/x)
32 #else
33 # define SPRINTF(x) ((size_t)sprintf x)
34 #endif
35 
36 /* Forward. */
37 
38 static int	datepart(const char *, int, int, int, int *);
39 
40 /* Public. */
41 
42 /*%
43  * Convert a date in ASCII into the number of seconds since
44  * 1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
45  * digits required, no spaces allowed.
46  */
47 
48 u_int32_t
49 ns_datetosecs(const char *cp, int *errp) {
50 	struct tm time;
51 	u_int32_t result;
52 	int mdays, i;
53 	static const int days_per_month[12] =
54 		{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
55 
56 	if (strlen(cp) != 14U) {
57 		*errp = 1;
58 		return (0);
59 	}
60 	*errp = 0;
61 
62 	memset(&time, 0, sizeof time);
63 	time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
64 	time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
65 	time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
66 	time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
67 	time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
68 	time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
69 	if (*errp)		/*%< Any parse errors? */
70 		return (0);
71 
72 	/*
73 	 * OK, now because timegm() is not available in all environments,
74 	 * we will do it by hand.  Roll up sleeves, curse the gods, begin!
75 	 */
76 
77 #define SECS_PER_DAY    ((u_int32_t)24*60*60)
78 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
79 
80 	result  = time.tm_sec;				/*%< Seconds */
81 	result += time.tm_min * 60;			/*%< Minutes */
82 	result += time.tm_hour * (60*60);		/*%< Hours */
83 	result += (time.tm_mday - 1) * SECS_PER_DAY;	/*%< Days */
84 	/* Months are trickier.  Look without leaping, then leap */
85 	mdays = 0;
86 	for (i = 0; i < time.tm_mon; i++)
87 		mdays += days_per_month[i];
88 	result += mdays * SECS_PER_DAY;			/*%< Months */
89 	if (time.tm_mon > 1 && isleap(1900+time.tm_year))
90 		result += SECS_PER_DAY;		/*%< Add leapday for this year */
91 	/* First figure years without leapdays, then add them in.  */
92 	/* The loop is slow, FIXME, but simple and accurate.  */
93 	result += (time.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
94 	for (i = 70; i < time.tm_year; i++)
95 		if (isleap(1900+i))
96 			result += SECS_PER_DAY; /*%< Add leapday for prev year */
97 	return (result);
98 }
99 
100 /* Private. */
101 
102 /*%
103  * Parse part of a date.  Set error flag if any error.
104  * Don't reset the flag if there is no error.
105  */
106 static int
107 datepart(const char *buf, int size, int min, int max, int *errp) {
108 	int result = 0;
109 	int i;
110 
111 	for (i = 0; i < size; i++) {
112 		if (!isdigit((unsigned char)(buf[i])))
113 			*errp = 1;
114 		result = (result * 10) + buf[i] - '0';
115 	}
116 	if (result < min)
117 		*errp = 1;
118 	if (result > max)
119 		*errp = 1;
120 	return (result);
121 }
122 
123 /*! \file */
124