lib/dns/ttl.c

	ttl.c revision e851ea826066ac5a5b01c2c23218faa0273a12e8
/*
 * Copyright (C) 2004, 2005, 2007, 2011-2013  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2001  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 <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include <isc/buffer.h>
#include <isc/parseint.h>
#include <isc/print.h>
#include <isc/region.h>
#include <isc/string.h>
#include <isc/util.h>

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

#define RETERR(x) do { \
    isc_result_t _r = (x); \
    if (_r != ISC_R_SUCCESS) \
        return (_r); \
    } while (0)


static isc_result_t bind_ttl(isc_textregion_t *source, isc_uint32_t *ttl);

/*
 * Helper for dns_ttl_totext().
 */
static isc_result_t
ttlfmt(unsigned int t, const char *s, isc_boolean_t verbose,
       isc_boolean_t space, isc_buffer_t *target)
{
    char tmp[60];
    unsigned int len;
    isc_region_t region;

    if (verbose)
        len = snprintf(tmp, sizeof(tmp), "%s%u %s%s",
                   space ? " " : "",
                   t, s,
                   t == 1 ? "" : "s");
    else
        len = snprintf(tmp, sizeof(tmp), "%u%c", t, s[0]);

    INSIST(len + 1 <= sizeof(tmp));
    isc_buffer_availableregion(target, &region);
    if (len > region.length)
        return (ISC_R_NOSPACE);
    memmove(region.base, tmp, len);
    isc_buffer_add(target, len);

    return (ISC_R_SUCCESS);
}

/*
 * Derived from bind8 ns_format_ttl().
 */
isc_result_t
dns_ttl_totext(isc_uint32_t src, isc_boolean_t verbose, isc_buffer_t *target) {
    unsigned secs, mins, hours, days, weeks, x;

    secs = src % 60;   src /= 60;
    mins = src % 60;   src /= 60;
    hours = src % 24;  src /= 24;
    days = src % 7;    src /= 7;
    weeks = src;       src = 0;
    POST(src);

    x = 0;
    if (weeks != 0) {
        RETERR(ttlfmt(weeks, "week", verbose, ISC_TF(x > 0), target));
        x++;
    }
    if (days != 0) {
        RETERR(ttlfmt(days, "day", verbose, ISC_TF(x > 0), target));
        x++;
    }
    if (hours != 0) {
        RETERR(ttlfmt(hours, "hour", verbose, ISC_TF(x > 0), target));
        x++;
    }
    if (mins != 0) {
        RETERR(ttlfmt(mins, "minute", verbose, ISC_TF(x > 0), target));
        x++;
    }
    if (secs != 0 ||
        (weeks == 0 && days == 0 && hours == 0 && mins == 0)) {
        RETERR(ttlfmt(secs, "second", verbose, ISC_TF(x > 0), target));
        x++;
    }
    INSIST (x > 0);
    /*
     * If only a single unit letter is printed, print it
     * in upper case. (Why?  Because BIND 8 does that.
     * Presumably it has a reason.)
     */
    if (x == 1 && !verbose) {
        isc_region_t region;
        /*
         * The unit letter is the last character in the
         * used region of the buffer.
         *
         * toupper() does not need its argument to be masked of cast
         * here because region.base is type unsigned char *.
         */
        isc_buffer_usedregion(target, &region);
        region.base[region.length - 1] =
            toupper(region.base[region.length - 1]);
    }
    return (ISC_R_SUCCESS);
}

isc_result_t
dns_counter_fromtext(isc_textregion_t *source, isc_uint32_t *ttl) {
    return (bind_ttl(source, ttl));
}

isc_result_t
dns_ttl_fromtext(isc_textregion_t *source, isc_uint32_t *ttl) {
    isc_result_t result;

    result = bind_ttl(source, ttl);
    if (result != ISC_R_SUCCESS)
        result = DNS_R_BADTTL;
    return (result);
}

static isc_result_t
bind_ttl(isc_textregion_t *source, isc_uint32_t *ttl) {
    isc_uint32_t tmp = 0;
    isc_uint32_t n;
    char *s;
    char buf[64];
    char nbuf[64]; /* Number buffer */

    /*
     * Copy the buffer as it may not be NULL terminated.
     * No legal counter / ttl is longer that 63 characters.
     */
    if (source->length > sizeof(buf) - 1)
        return (DNS_R_SYNTAX);
    strncpy(buf, source->base, source->length);
    buf[source->length] = '\0';
    s = buf;

    do {
        isc_result_t result;

        char *np = nbuf;
        while (*s != '\0' && isdigit((unsigned char)*s))
            *np++ = *s++;
        *np++ = '\0';
        INSIST(np - nbuf <= (int)sizeof(nbuf));
        result = isc_parse_uint32(&n, nbuf, 10);
        if (result != ISC_R_SUCCESS)
            return (DNS_R_SYNTAX);
        switch (*s) {
        case 'w':
        case 'W':
            tmp += n * 7 * 24 * 3600;
            s++;
            break;
        case 'd':
        case 'D':
            tmp += n * 24 * 3600;
            s++;
            break;
        case 'h':
        case 'H':
            tmp += n * 3600;
            s++;
            break;
        case 'm':
        case 'M':
            tmp += n * 60;
            s++;
            break;
        case 's':
        case 'S':
            tmp += n;
            s++;
            break;
        case '\0':
            /* Plain number? */
            if (tmp != 0)
                return (DNS_R_SYNTAX);
            tmp = n;
            break;
        default:
            return (DNS_R_SYNTAX);
        }
    } while (*s != '\0');
    *ttl = tmp;
    return (ISC_R_SUCCESS);
}