common/nameser/ns_ttl.c

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996,1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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.
 */

#ifndef lint
static const char rcsid[] = "$Id: ns_ttl.c,v 1.4 2005/07/28 06:51:49 marka Exp $";
#endif

/* Import. */

#include "port_before.h"

#include <arpa/nameser.h>

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include "port_after.h"

#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif

/* Forward. */

static int  fmt1(int t, char s, char **buf, size_t *buflen);

/* Macros. */

#define T(x) if ((x) < 0) return (-1); else (void)NULL

/* Public. */

int
ns_format_ttl(u_long src, char *dst, size_t dstlen) {
    char *odst = dst;
    int secs, mins, hours, days, weeks, x;
    char *p;

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

    x = 0;
    if (weeks) {
        T(fmt1(weeks, 'W', &dst, &dstlen));
        x++;
    }
    if (days) {
        T(fmt1(days, 'D', &dst, &dstlen));
        x++;
    }
    if (hours) {
        T(fmt1(hours, 'H', &dst, &dstlen));
        x++;
    }
    if (mins) {
        T(fmt1(mins, 'M', &dst, &dstlen));
        x++;
    }
    if (secs || !(weeks || days || hours || mins)) {
        T(fmt1(secs, 'S', &dst, &dstlen));
        x++;
    }

    if (x > 1) {
        int ch;

        for (p = odst; (ch = *p) != '\0'; p++)
            if (isascii(ch) && isupper(ch))
                *p = tolower(ch);
    }

    return (dst - odst);
}

int
ns_parse_ttl(const char *src, u_long *dst) {
    u_long ttl, tmp;
    int ch, digits, dirty;

    ttl = 0;
    tmp = 0;
    digits = 0;
    dirty = 0;
    while ((ch = *src++) != '\0') {
        if (!isascii(ch) || !isprint(ch))
            goto einval;
        if (isdigit(ch)) {
            tmp *= 10;
            tmp += (ch - '0');
            digits++;
            continue;
        }
        if (digits == 0)
            goto einval;
        if (islower(ch))
            ch = toupper(ch);
        switch (ch) {
        case 'W':  tmp *= 7;
        case 'D':  tmp *= 24;
        case 'H':  tmp *= 60;
        case 'M':  tmp *= 60;
        case 'S':  break;
        default:   goto einval;
        }
        ttl += tmp;
        tmp = 0;
        digits = 0;
        dirty = 1;
    }
    if (digits > 0) {
        if (dirty)
            goto einval;
        else
            ttl += tmp;
    } else if (!dirty)
        goto einval;
    *dst = ttl;
    return (0);

 einval:
    errno = EINVAL;
    return (-1);
}

/* Private. */

static int
fmt1(int t, char s, char **buf, size_t *buflen) {
    char tmp[50];
    size_t len;

    len = SPRINTF((tmp, "%d%c", t, s));
    if (len + 1 > *buflen)
        return (-1);
    strcpy(*buf, tmp);
    *buf += len;
    *buflen -= len;
    return (0);
}

/*! \file */