source: rtems/cpukit/libnetworking/libc/inet_net_ntop.c @ 09fdb5e8

/*
 * Copyright (c) 1996 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM 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.
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

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

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

static char *   inet_net_ntop_ipv4 __P((const u_char *src, int bits,
                                        char *dst, size_t size));

/*
 * char *
 * inet_net_ntop(af, src, bits, dst, size)
 *      convert network number from network to presentation format.
 *      generates CIDR style result always.
 * return:
 *      pointer to dst, or NULL if an error occurred (check errno).
 * author:
 *      Paul Vixie (ISC), July 1996
 */
char *
inet_net_ntop(af, src, bits, dst, size)
        int af;
        const void *src;
        int bits;
        char *dst;
        size_t size;
{
        switch (af) {
        case AF_INET:
                return (inet_net_ntop_ipv4(src, bits, dst, size));
        default:
                errno = EAFNOSUPPORT;
                return (NULL);
        }
}

/*
 * static char *
 * inet_net_ntop_ipv4(src, bits, dst, size)
 *      convert IPv4 network number from network to presentation format.
 *      generates CIDR style result always.
 * return:
 *      pointer to dst, or NULL if an error occurred (check errno).
 * note:
 *      network byte order assumed.  this means 192.5.5.240/28 has
 *      0x11110000 in its fourth octet.
 * author:
 *      Paul Vixie (ISC), July 1996
 */
static char *
inet_net_ntop_ipv4(src, bits, dst, size)
        const u_char *src;
        int bits;
        char *dst;
        size_t size;
{
        char *odst = dst;
        char *t;
        u_int m;
        int b;

        if (bits < 0 || bits > 32) {
                errno = EINVAL;
                return (NULL);
        }
        if (bits == 0) {
                if (size < sizeof "0")
                        goto emsgsize;
                *dst++ = '0';
                *dst = '\0';
        }

        /* Format whole octets. */
        for (b = bits / 8; b > 0; b--) {
                if (size < sizeof "255.")
                        goto emsgsize;
                t = dst;
                dst += SPRINTF((dst, "%u", *src++));
                if (b > 1) {
                        *dst++ = '.';
                        *dst = '\0';
                }
                size -= (size_t)(dst - t);
        }

        /* Format partial octet. */
        b = bits % 8;
        if (b > 0) {
                if (size < sizeof ".255")
                        goto emsgsize;
                t = dst;
                if (dst != odst)
                        *dst++ = '.';
                m = ((1 << b) - 1) << (8 - b);
                dst += SPRINTF((dst, "%u", *src & m));
                size -= (size_t)(dst - t);
        }

        /* Format CIDR /width. */
        if (size < sizeof "/32")
                goto emsgsize;
        dst += SPRINTF((dst, "/%u", bits));
        return (odst);

 emsgsize:
        errno = EMSGSIZE;
        return (NULL);
}