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ns_date.c revision 1.1 
      1 /*	$NetBSD: ns_date.c,v 1.1 2012/11/15 18:48:48 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 #include <sys/cdefs.h>
     21 #if 0
     22 static const char rcsid[] = "Id: ns_date.c,v 1.6 2005/04/27 04:56:39 sra Exp ";
     23 #else
     24 __RCSID("$NetBSD: ns_date.c,v 1.1 2012/11/15 18:48:48 christos Exp $");
     25 #endif
     26 
     27 /* Import. */
     28 
     29 #include "port_before.h"
     30 
     31 #include <arpa/nameser.h>
     32 
     33 #include <ctype.h>
     34 #include <errno.h>
     35 #include <stdio.h>
     36 #include <string.h>
     37 #include <time.h>
     38 
     39 #include "port_after.h"
     40 
     41 #ifdef SPRINTF_CHAR
     42 # define SPRINTF(x) strlen(sprintf/**/x)
     43 #else
     44 # define SPRINTF(x) ((size_t)sprintf x)
     45 #endif
     46 
     47 /* Forward. */
     48 
     49 static int	datepart(const char *, int, int, int, int *);
     50 
     51 /* Public. */
     52 
     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  */
     58 
     59 u_int32_t
     60 ns_datetosecs(const char *cp, int *errp) {
     61 	struct tm tim;
     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) != 14U) {
     68 		*errp = 1;
     69 		return (0);
     70 	}
     71 	*errp = 0;
     72 
     73 	memset(&tim, 0, sizeof tim);
     74 	tim.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
     75 	tim.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
     76 	tim.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
     77 	tim.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
     78 	tim.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
     79 	tim.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  = tim.tm_sec;				/*%< Seconds */
     92 	result += tim.tm_min * 60;			/*%< Minutes */
     93 	result += tim.tm_hour * (60*60);		/*%< Hours */
     94 	result += (tim.tm_mday - 1) * SECS_PER_DAY;	/*%< Days */
     95 	/* Months are trickier.  Look without leaping, then leap */
     96 	mdays = 0;
     97 	for (i = 0; i < tim.tm_mon; i++)
     98 		mdays += days_per_month[i];
     99 	result += mdays * SECS_PER_DAY;			/*%< Months */
    100 	if (tim.tm_mon > 1 && isleap(1900+tim.tm_year))
    101 		result += SECS_PER_DAY;		/*%< Add leapday for this year */
    102 	/* First figure years without leapdays, then add them in.  */
    103 	/* The loop is slow, FIXME, but simple and accurate.  */
    104 	result += (tim.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
    105 	for (i = 70; i < tim.tm_year; i++)
    106 		if (isleap(1900+i))
    107 			result += SECS_PER_DAY; /*%< Add leapday for prev year */
    108 	return (result);
    109 }
    110 
    111 /* Private. */
    112 
    113 /*%
    114  * Parse part of a date.  Set error flag if any error.
    115  * Don't reset the flag if there is no error.
    116  */
    117 static int
    118 datepart(const char *buf, int size, int min, int max, int *errp) {
    119 	int result = 0;
    120 	int i;
    121 
    122 	for (i = 0; i < size; i++) {
    123 		if (!isdigit((unsigned char)(buf[i])))
    124 			*errp = 1;
    125 		result = (result * 10) + buf[i] - '0';
    126 	}
    127 	if (result < min)
    128 		*errp = 1;
    129 	if (result > max)
    130 		*errp = 1;
    131 	return (result);
    132 }
    133 
    134 /*! \file */
    135