ns_date.c

   1 /*
   2  * Copyright (c) 1999 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 #ifndef __APPLE__
  19 #ifndef lint
  20 static const char rcsid[] = "$Id: ns_date.c,v 1.1 2006/03/01 19:01:36 majka Exp $";
  21 #endif
  22 #endif
  23
  24 /* Import. */
  25
  26 #ifndef __APPLE__
  27 #include "port_before.h"
  28 #endif
  29
  30 #include <arpa/nameser.h>
  31
  32 #include <ctype.h>
  33 #include <errno.h>
  34 #include <stdio.h>
  35 #include <string.h>
  36 #include <time.h>
  37
  38 #ifndef __APPLE__
  39 #include "port_after.h"
  40 #endif
  41
  42 #ifdef SPRINTF_CHAR
  43 # define SPRINTF(x) strlen(sprintf/**/x)
  44 #else
  45 # define SPRINTF(x) ((size_t)sprintf x)
  46 #endif
  47
  48 /* Forward. */
  49
  50 static int      datepart(const char *, int, int, int, int *);
  51
  52 /* Public. */
  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 u_int32_t
  59 ns_datetosecs(const char *cp, int *errp) {
  60         struct tm time;
  61         u_int32_t result;
  62         int mdays, i;
  63         static const int days_per_month[12] =
  64                 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  65
  66         if (strlen(cp) != 14) {
  67                 *errp = 1;
  68                 return (0);
  69         }
  70         *errp = 0;
  71
  72         memset(&time, 0, sizeof time);
  73         time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
  74         time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
  75         time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
  76         time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
  77         time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
  78         time.tm_sec   = datepart(cp + 12, 2,   00,   59, errp);
  79         if (*errp)              /* Any parse errors? */
  80                 return (0);
  81
  82         /*
  83          * OK, now because timegm() is not available in all environments,
  84          * we will do it by hand.  Roll up sleeves, curse the gods, begin!
  85          */
  86
  87 #define SECS_PER_DAY    ((u_int32_t)24*60*60)
  88 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  89
  90         result  = time.tm_sec;                          /* Seconds */
  91         result += time.tm_min * 60;                     /* Minutes */
  92         result += time.tm_hour * (60*60);               /* Hours */
  93         result += (time.tm_mday - 1) * SECS_PER_DAY;    /* Days */
  94
  95         /* Months are trickier.  Look without leaping, then leap */
  96         mdays = 0;
  97         for (i = 0; i < time.tm_mon; i++)
  98                 mdays += days_per_month[i];
  99         result += mdays * SECS_PER_DAY;                 /* Months */
 100         if (time.tm_mon > 1 && isleap(1900+time.tm_year))
 101                 result += SECS_PER_DAY;         /* Add leapday for this year */
 102
 103         /* First figure years without leapdays, then add them in.  */
 104         /* The loop is slow, FIXME, but simple and accurate.  */
 105         result += (time.tm_year - 70) * (SECS_PER_DAY*365); /* Years */
 106         for (i = 70; i < time.tm_year; i++)
 107                 if (isleap(1900+i))
 108                         result += SECS_PER_DAY; /* Add leapday for prev year */
 109
 110         return (result);
 111 }
 112
 113 /* Private. */
 114
 115 /*
 116  * Parse part of a date.  Set error flag if any error.
 117  * Don't reset the flag if there is no error.
 118  */
 119 static int
 120 datepart(const char *buf, int size, int min, int max, int *errp) {
 121         int result = 0;
 122         int i;
 123
 124         for (i = 0; i < size; i++) {
 125                 if (!isdigit((unsigned char)(buf[i])))
 126                         *errp = 1;
 127                 result = (result * 10) + buf[i] - '0';
 128         }
 129         if (result < min)
 130                 *errp = 1;
 131         if (result > max)
 132                 *errp = 1;
 133         return (result);
 134 }