contrib/dhcp-3.0/minires/ns_date.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1999-2003 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  *   Internet Systems Consortium, Inc.
  18  *   950 Charter Street
  19  *   Redwood City, CA 94063
  20  *   <info@isc.org>
  21  *   http://www.isc.org/
  22  */
  23
  24 #ifndef lint
  25 static const char rcsid[] = "$Id: ns_date.c,v 1.2.2.1 2004/06/10 17:59:40 dhankins Exp $";
  26 #endif
  27
  28 /* Import. */
  29
  30 #include <ctype.h>
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <time.h>
  35
  36 #include <sys/types.h>
  37 #include <netinet/in.h>
  38 #include <sys/socket.h>
  39
  40 #include "minires/minires.h"
  41 #include "arpa/nameser.h"
  42
  43 #ifdef SPRINTF_CHAR
  44 # define SPRINTF(x) strlen(sprintf/**/x)
  45 #else
  46 # define SPRINTF(x) ((size_t)sprintf x)
  47 #endif
  48
  49 /* Forward. */
  50
  51 static int      datepart(const char *, int, int, int, int *);
  52
  53 /* Public. */
  54
  55 /* Convert a date in ASCII into the number of seconds since
  56    1 January 1970 (GMT assumed).  Format is yyyymmddhhmmss, all
  57    digits required, no spaces allowed.  */
  58
  59 u_int32_t
  60 ns_datetosecs(const char *cp, int *errp) {
  61         struct tm time;
  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) != 14) {
  68                 *errp = 1;
  69                 return (0);
  70         }
  71         *errp = 0;
  72
  73         memset(&time, 0, sizeof time);
  74         time.tm_year  = datepart(cp +  0, 4, 1990, 9999, errp) - 1900;
  75         time.tm_mon   = datepart(cp +  4, 2,   01,   12, errp) - 1;
  76         time.tm_mday  = datepart(cp +  6, 2,   01,   31, errp);
  77         time.tm_hour  = datepart(cp +  8, 2,   00,   23, errp);
  78         time.tm_min   = datepart(cp + 10, 2,   00,   59, errp);
  79         time.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  = time.tm_sec;                          /* Seconds */
  92         result += time.tm_min * 60;                     /* Minutes */
  93         result += time.tm_hour * (60*60);               /* Hours */
  94         result += (time.tm_mday - 1) * SECS_PER_DAY;    /* Days */
  95
  96         /* Months are trickier.  Look without leaping, then leap */
  97         mdays = 0;
  98         for (i = 0; i < time.tm_mon; i++)
  99                 mdays += days_per_month[i];
 100         result += mdays * SECS_PER_DAY;                 /* Months */
 101         if (time.tm_mon > 1 && isleap(1900+time.tm_year))
 102                 result += SECS_PER_DAY;         /* Add leapday for this year */
 103
 104         /* First figure years without leapdays, then add them in.  */
 105         /* The loop is slow, FIXME, but simple and accurate.  */
 106         result += (time.tm_year - 70) * (SECS_PER_DAY*365); /* Years */
 107         for (i = 70; i < time.tm_year; i++)
 108                 if (isleap(1900+i))
 109                         result += SECS_PER_DAY; /* Add leapday for prev year */
 110
 111         return (result);
 112 }
 113
 114 /* Private. */
 115
 116 /*
 117  * Parse part of a date.  Set error flag if any error.
 118  * Don't reset the flag if there is no error.
 119  */
 120 static int
 121 datepart(const char *buf, int size, int min, int max, int *errp) {
 122         int result = 0;
 123         int i;
 124
 125         for (i = 0; i < size; i++) {
 126                 if (!isdigit(buf[i]))
 127                         *errp = 1;
 128                 result = (result * 10) + buf[i] - '0';
 129         }
 130         if (result < min)
 131                 *errp = 1;
 132         if (result > max)
 133                 *errp = 1;
 134         return (result);
 135 }