external/bsd/libbind/dist/nameser/ns_date.c

   1 /*      $NetBSD$        */
   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 #ifndef lint
  21 static const char rcsid[] = "Id: ns_date.c,v 1.6 2005/04/27 04:56:39 sra Exp";
  22 #endif
  23
  24 /* Import. */
  25
  26 #include "port_before.h"
  27
  28 #include <arpa/nameser.h>
  29
  30 #include <ctype.h>
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <time.h>
  35
  36 #include "port_after.h"
  37
  38 #ifdef SPRINTF_CHAR
  39 # define SPRINTF(x) strlen(sprintf/**/x)
  40 #else
  41 # define SPRINTF(x) ((size_t)sprintf x)
  42 #endif
  43
  44 /* Forward. */
  45
  46 static int      datepart(const char *, int, int, int, int *);
  47
  48 /* Public. */
  49
  50 /*%
  51  * Convert a date in ASCII into the number of seconds since
  52  * 1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
  53  * digits required, no spaces allowed.
  54  */
  55
  56 u_int32_t
  57 ns_datetosecs(const char *cp, int *errp) {
  58         struct tm time;
  59         u_int32_t result;
  60         int mdays, i;
  61         static const int days_per_month[12] =
  62                 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  63
  64         if (strlen(cp) != 14U) {
  65                 *errp = 1;
  66                 return (0);
  67         }
  68         *errp = 0;
  69
  70         memset(&time, 0, sizeof time);
  71         time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
  72         time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
  73         time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
  74         time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
  75         time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
  76         time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
  77         if (*errp)              /*%< Any parse errors? */
  78                 return (0);
  79
  80         /*
  81          * OK, now because timegm() is not available in all environments,
  82          * we will do it by hand.  Roll up sleeves, curse the gods, begin!
  83          */
  84
  85 #define SECS_PER_DAY    ((u_int32_t)24*60*60)
  86 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  87
  88         result  = time.tm_sec;                          /*%< Seconds */
  89         result += time.tm_min * 60;                     /*%< Minutes */
  90         result += time.tm_hour * (60*60);               /*%< Hours */
  91         result += (time.tm_mday - 1) * SECS_PER_DAY;    /*%< Days */
  92         /* Months are trickier.  Look without leaping, then leap */
  93         mdays = 0;
  94         for (i = 0; i < time.tm_mon; i++)
  95                 mdays += days_per_month[i];
  96         result += mdays * SECS_PER_DAY;                 /*%< Months */
  97         if (time.tm_mon > 1 && isleap(1900+time.tm_year))
  98                 result += SECS_PER_DAY;         /*%< Add leapday for this year */
  99         /* First figure years without leapdays, then add them in.  */
 100         /* The loop is slow, FIXME, but simple and accurate.  */
 101         result += (time.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
 102         for (i = 70; i < time.tm_year; i++)
 103                 if (isleap(1900+i))
 104                         result += SECS_PER_DAY; /*%< Add leapday for prev year */
 105         return (result);
 106 }
 107
 108 /* Private. */
 109
 110 /*%
 111  * Parse part of a date.  Set error flag if any error.
 112  * Don't reset the flag if there is no error.
 113  */
 114 static int
 115 datepart(const char *buf, int size, int min, int max, int *errp) {
 116         int result = 0;
 117         int i;
 118
 119         for (i = 0; i < size; i++) {
 120                 if (!isdigit((unsigned char)(buf[i])))
 121                         *errp = 1;
 122                 result = (result * 10) + buf[i] - '0';
 123         }
 124         if (result < min)
 125                 *errp = 1;
 126         if (result > max)
 127                 *errp = 1;
 128         return (result);
 129 }
 130
 131 /*! \file */