time.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2009-2012, 2014  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.
 */

/* $Id$ */

/*! \file */

#include <config.h>

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

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

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

static const 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;

/*
 * Warning. Do NOT use arguments with side effects with these macros.
 */
#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 (t < 0) {
                if (tm.tm_year == 0)
                        return (ISC_R_RANGE);
                tm.tm_year--;
                secs = year_secs(tm.tm_year + 1900);
                t += secs;
        }
        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);

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

isc_int64_t
dns_time64_from32(isc_uint32_t value) {
        isc_stdtime_t now;
        isc_int64_t start;
        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;
        if (isc_serial_gt(value, now))
                t = start + (value - now);
        else
                t = start - (now - value);

        return (t);
}

isc_result_t
dns_time32_totext(isc_uint32_t value, isc_buffer_t *target) {
        return (dns_time64_totext(dns_time64_from32(value), 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);
        /*
         * Confirm the source only consists digits.  sscanf() allows some
         * minor exceptions.
         */
        for (i = 0; i < 14; i++) {
                if (!isdigit((unsigned char)source[i]))
                        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(0, 9999, year);
        RANGE(1, 12, month);
        RANGE(1, days[month - 1] +
                 ((month == 2 && is_leap(year)) ? 1 : 0), day);
#ifdef __COVERITY__
        /*
         * Use a simplified range to silence Coverity warning (in
         * arithmetic with day below).
         */
        RANGE(1, 31, day);
#endif /* __COVERITY__ */

        RANGE(0, 23, hour);
        RANGE(0, 59, minute);
        RANGE(0, 60, second);           /* 60 == leap second. */

        /*
         * Calculate seconds from epoch.
         * Note: this uses a idealized calendar.
         */
        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;
        if (year < 1970) {
                for (i = 1969; i >= year; i--) {
                        secs = (is_leap(i) ? 366 : 365) * 86400;
                        value -= secs;
                }
        } else {
                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);
}

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