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  /* Import. */
      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  #define SPRINTF(x) ((size_t)sprintf x)
      29  
      30  /* Forward. */
      31  
      32  static int	datepart(const char *, int, int, int, int *);
      33  
      34  /* Public. */
      35  
      36  /*%
      37   * Convert a date in ASCII into the number of seconds since
      38   * 1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
      39   * digits required, no spaces allowed.
      40   */
      41  
      42  uint32_t
      43  ns_datetosecs(const char *cp, int *errp) {
      44  	struct tm time;
      45  	uint32_t result;
      46  	int mdays, i;
      47  	static const int days_per_month[12] =
      48  		{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
      49  
      50  	if (strlen(cp) != 14U) {
      51  		*errp = 1;
      52  		return (0);
      53  	}
      54  	*errp = 0;
      55  
      56  	memset(&time, 0, sizeof time);
      57  	time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
      58  	time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
      59  	time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
      60  	time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
      61  	time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
      62  	time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
      63  	if (*errp)		/*%< Any parse errors? */
      64  		return (0);
      65  
      66  	/*
      67  	 * OK, now because timegm() is not available in all environments,
      68  	 * we will do it by hand.  Roll up sleeves, curse the gods, begin!
      69  	 */
      70  
      71  #define SECS_PER_DAY    ((uint32_t)24*60*60)
      72  #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
      73  
      74  	result  = time.tm_sec;				/*%< Seconds */
      75  	result += time.tm_min * 60;			/*%< Minutes */
      76  	result += time.tm_hour * (60*60);		/*%< Hours */
      77  	result += (time.tm_mday - 1) * SECS_PER_DAY;	/*%< Days */
      78  	/* Months are trickier.  Look without leaping, then leap */
      79  	mdays = 0;
      80  	for (i = 0; i < time.tm_mon; i++)
      81  		mdays += days_per_month[i];
      82  	result += mdays * SECS_PER_DAY;			/*%< Months */
      83  	if (time.tm_mon > 1 && isleap(1900+time.tm_year))
      84  		result += SECS_PER_DAY;		/*%< Add leapday for this year */
      85  	/* First figure years without leapdays, then add them in.  */
      86  	/* The loop is slow, FIXME, but simple and accurate.  */
      87  	result += (time.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
      88  	for (i = 70; i < time.tm_year; i++)
      89  		if (isleap(1900+i))
      90  			result += SECS_PER_DAY; /*%< Add leapday for prev year */
      91  	return (result);
      92  }
      93  
      94  /* Private. */
      95  
      96  /*%
      97   * Parse part of a date.  Set error flag if any error.
      98   * Don't reset the flag if there is no error.
      99   */
     100  static int
     101  datepart(const char *buf, int size, int min, int max, int *errp) {
     102  	int result = 0;
     103  	int i;
     104  
     105  	for (i = 0; i < size; i++) {
     106  		if (!isdigit((unsigned char)(buf[i])))
     107  			*errp = 1;
     108  		result = (result * 10) + buf[i] - '0';
     109  	}
     110  	if (result < min)
     111  		*errp = 1;
     112  	if (result > max)
     113  		*errp = 1;
     114  	return (result);
     115  }
     116  
     117  /*! \file */