The Net: Ultimate Internet Guide/WWLCD1.ISO/pc/java/in4wjcxu/other/irc/common/inet_addr.c

C/C++ Source or Header | 1996-08-14 | 5.3 KB | 177 lines

/*
 * ++Copyright++ 1983, 1990, 1993
 * -
 * Copyright (c) 1983, 1990, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *     This product includes software developed by the University of
 *     California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * -
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * 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, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION 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.
 * -
 * --Copyright--
 */

#include "sys.h"
#include "common.h"
#include <netinet/in.h>
#include "nameser.h"
#include "resolv.h"

/* this is a compatibility routine, not needed on recent BSD releases */
#ifdef    NEED_INET_ADDR
/*
 * Ascii internet address interpretation routine.
 * The value returned is in network order.
 */
u_long
inet_addr(cp)
    register const char *cp;
{
    struct in_addr val;

    if (inet_aton(cp, &val))
        return (val.s_addr);
    return (INADDR_NONE);
}
#endif

/*
 * Check whether "cp" is a valid ascii representation
 * of an Internet address and convert to a binary address.
 * Returns 1 if the address is valid, 0 if not.
 * This replaces inet_addr, the return value from which
 * cannot distinguish between failure and a local broadcast address.
 */
#ifdef    NEED_INET_ATON
int
inet_aton(cp, addr)
    register const char *cp;
    struct in_addr *addr;
{
    register u_long val;
    register int base, n;
    register char c;
    u_int parts[4];
    register u_int *pp = parts;

    for (;;) {
        /*
         * Collect number up to ``.''.
         * Values are specified as for C:
         * 0x=hex, 0=octal, other=decimal.
         */
        val = 0; base = 10;
        if (*cp == '0') {
            if (*++cp == 'x' || *cp == 'X')
                base = 16, cp++;
            else
                base = 8;
        }
        while ((c = *cp) != '\0') {
            if (isascii(c) && isdigit(c)) {
                val = (val * base) + (c - '0');
                cp++;
                continue;
            }
            if (base == 16 && isascii(c) && isxdigit(c)) {
                val = (val << 4) +
                    (c + 10 - (islower(c) ? 'a' : 'A'));
                cp++;
                continue;
            }
            break;
        }
        if (*cp == '.') {
            /*
             * Internet format:
             *    a.b.c.d
             *    a.b.c    (with c treated as 16-bits)
             *    a.b    (with b treated as 24 bits)
             */
            if (pp >= parts + 3 || val > 0xff)
                return (0);
            *pp++ = val, cp++;
        } else
            break;
    }
    /*
     * Check for trailing characters.
     */
    if (*cp && (!isascii(*cp) || !isspace(*cp)))
        return (0);
    /*
     * Concoct the address according to
     * the number of parts specified.
     */
    n = pp - parts + 1;
    switch (n) {

    case 1:                /* a -- 32 bits */
        break;

    case 2:                /* a.b -- 8.24 bits */
        if (val > 0xffffff)
            return (0);
        val |= parts[0] << 24;
        break;

    case 3:                /* a.b.c -- 8.8.16 bits */
        if (val > 0xffff)
            return (0);
        val |= (parts[0] << 24) | (parts[1] << 16);
        break;

    case 4:                /* a.b.c.d -- 8.8.8.8 bits */
        if (val > 0xff)
            return (0);
        val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
        break;
    }
    if (addr)
        addr->s_addr = htonl(val);
    return (1);
}
#endif