common/inet/inet_neta.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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$Id: inet_neta.c,v 1.3 2005/04/27 04:56:20 sra Exp $";
#endif

#include "port_before.h"

#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 "port_after.h"

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

/*%
 * char *
 * inet_neta(src, dst, size)
 *  format a u_long network number into presentation format.
 * return:
 *  pointer to dst, or NULL if an error occurred (check errno).
 * note:
 *  format of ``src'' is as for inet_network().
 * author:
 *  Paul Vixie (ISC), July 1996
 */
char *
inet_neta(src, dst, size)
    u_long src;
    char *dst;
    size_t size;
{
    char *odst = dst;
    char *tp;

    while (src & 0xffffffff) {
        u_char b = (src & 0xff000000) >> 24;

        src <<= 8;
        if (b) {
            if (size < sizeof "255.")
                goto emsgsize;
            tp = dst;
            dst += SPRINTF((dst, "%u", b));
            if (src != 0L) {
                *dst++ = '.';
                *dst = '\0';
            }
            size -= (size_t)(dst - tp);
        }
    }
    if (dst == odst) {
        if (size < sizeof "0.0.0.0")
            goto emsgsize;
        strcpy(dst, "0.0.0.0");
    }
    return (odst);

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

/*! \file */