lib/dns/time.c

	time.c revision 70e5a7403f0e0a3bd292b8287c5fed5772c15270
/*
 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: time.c,v 1.31 2007/06/19 23:47:16 tbox Exp $ */

/*! \file */

#include <config.h>

#include <stdio.h>
#include <isc/string.h>     /* Required for HP/UX (and others?) */
#include <time.h>

#include <isc/print.h>
#include <isc/region.h>
#include <isc/stdtime.h>
#include <isc/util.h>

#include <dns/result.h>
#include <dns/time.h>

static int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

isc_result_t
dns_time64_totext(isc_int64_t t, isc_buffer_t *target) {
    struct tm tm;
    char buf[sizeof("YYYYMMDDHHMMSS")];
    int secs;
    unsigned int l;
    isc_region_t region;

    REQUIRE(t >= 0);

#define is_leap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
#define year_secs(y) ((is_leap(y) ? 366 : 365 ) * 86400)
#define month_secs(m,y) ((days[m] + ((m == 1 && is_leap(y)) ? 1 : 0 )) * 86400)

    tm.tm_year = 70;
    while ((secs = year_secs(tm.tm_year + 1900)) <= t) {
        t -= secs;
        tm.tm_year++;
        if (tm.tm_year + 1900 > 9999)
            return (ISC_R_RANGE);
    }
    tm.tm_mon = 0;
    while ((secs = month_secs(tm.tm_mon, tm.tm_year + 1900)) <= t) {
        t -= secs;
        tm.tm_mon++;
    }
    tm.tm_mday = 1;
    while (86400 <= t) {
        t -= 86400;
        tm.tm_mday++;
    }
    tm.tm_hour = 0;
    while (3600 <= t) {
        t -= 3600;
        tm.tm_hour++;
    }
    tm.tm_min = 0;
    while (60 <= t) {
        t -= 60;
        tm.tm_min++;
    }
    tm.tm_sec = (int)t;
                 /* yyyy  mm  dd  HH  MM  SS */
    snprintf(buf, sizeof(buf), "%04d%02d%02d%02d%02d%02d",
         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
         tm.tm_hour, tm.tm_min, tm.tm_sec);

    isc_buffer_availableregion(target, &region);
    l = strlen(buf);

    if (l > region.length)
        return (ISC_R_NOSPACE);

    memcpy(region.base, buf, l);
    isc_buffer_add(target, l);
    return (ISC_R_SUCCESS);
}

isc_result_t
dns_time32_totext(isc_uint32_t value, isc_buffer_t *target) {
    isc_stdtime_t now;
    isc_int64_t start;
    isc_int64_t base;
    isc_int64_t t;

    /*
     * Adjust the time to the closest epoch.  This should be changed
     * to use a 64-bit counterpart to isc_stdtime_get() if one ever
     * is defined, but even the current code is good until the year
     * 2106.
     */
    isc_stdtime_get(&now);
    start = (isc_int64_t) now;
    start -= 0x7fffffff;
    base = 0;
    while ((t = (base + value)) < start) {
        base += 0x80000000;
        base += 0x80000000;
    }
    return (dns_time64_totext(t, target));
}

isc_result_t
dns_time64_fromtext(const char *source, isc_int64_t *target) {
    int year, month, day, hour, minute, second;
    isc_int64_t value;
    int secs;
    int i;

#define RANGE(min, max, value) \
    do { \
        if (value < (min) || value > (max)) \
            return (ISC_R_RANGE); \
    } while (0)

    if (strlen(source) != 14U)
        return (DNS_R_SYNTAX);
    if (sscanf(source, "%4d%2d%2d%2d%2d%2d",
           &year, &month, &day, &hour, &minute, &second) != 6)
        return (DNS_R_SYNTAX);

    RANGE(1970, 9999, year);
    RANGE(1, 12, month);
    RANGE(1, days[month - 1] +
         ((month == 2 && is_leap(year)) ? 1 : 0), day);
    RANGE(0, 23, hour);
    RANGE(0, 59, minute);
    RANGE(0, 60, second);       /* 60 == leap second. */

    /*
     * Calulate seconds since epoch.
     */
    value = second + (60 * minute) + (3600 * hour) + ((day - 1) * 86400);
    for (i = 0; i < (month - 1); i++)
        value += days[i] * 86400;
    if (is_leap(year) && month > 2)
        value += 86400;
    for (i = 1970; i < year; i++) {
        secs = (is_leap(i) ? 366 : 365) * 86400;
        value += secs;
    }

    *target = value;
    return (ISC_R_SUCCESS);
}

isc_result_t
dns_time32_fromtext(const char *source, isc_uint32_t *target) {
    isc_int64_t value64;
    isc_result_t result;
    result = dns_time64_fromtext(source, &value64);
    if (result != ISC_R_SUCCESS)
        return (result);
    *target = (isc_uint32_t)value64;

    return (ISC_R_SUCCESS);
}