libc/net/ether_addr.c

	ether_addr.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Copyright (c) 1990 by Sun Microsystems, Inc.
 *
 * All routines necessary to deal with the file /etc/ethers.  The file
 * contains mappings from 48 bit ethernet addresses to their corresponding
 * hosts name.  The addresses have an ascii representation of the form
 * "x:x:x:x:x:x" where x is a hex number between 0x00 and 0xff;  the
 * bytes are always in network order.
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <net/if_arp.h>
#include <netinet/if_ether.h>

static char *domain; /* NIS domain name */
static int usingyellow;
static char *ethers = "/etc/ethers";

/*
 * Parses a line from /etc/ethers into its components.  The line has the form
 * 8:0:20:1:17:c8   krypton
 * where the first part is a 48 bit ethernet addrerss and the second is
 * the corresponding hosts name.
 * Returns zero if successful, non-zero otherwise.
 */
ether_line(s, e, hostname)
    char *s;        /* the string to be parsed */
    struct ether_addr *e;   /* ethernet address struct to be filled in */
    char *hostname;     /* hosts name to be set */
{
    register int i;
    unsigned int t[6];

    i = sscanf(s, " %x:%x:%x:%x:%x:%x %s",
        &t[0], &t[1], &t[2], &t[3], &t[4], &t[5], hostname);
    if (i != 7) {
        return (7 - i);
    }
    for (i = 0; i < 6; i++)
        e->ether_addr_octet[i] = t[i];
    return (0);
}

/*
 * Converts a 48 bit ethernet number to its string representation.
 */
#define EI(i)   (unsigned int)(e->ether_addr_octet[(i)])
char *
ether_ntoa(e)
    struct ether_addr *e;
{
    static char *s;

    if (s == 0) {
        s = (char *)malloc(18);
        if (s == 0)
            return (0);
    }
    s[0] = 0;
    sprintf(s, "%x:%x:%x:%x:%x:%x",
        EI(0), EI(1), EI(2), EI(3), EI(4), EI(5));
    return (s);
}

/*
 * Converts a ethernet address representation back into its 48 bits.
 */
struct ether_addr *
ether_aton(s)
    char *s;
{
    static struct ether_addr *ep;
    register int i;
    unsigned int t[6];

    if (ep == 0) {
        ep = (struct ether_addr *)calloc(1, sizeof (struct ether_addr));
        if (ep == 0)
            return (0);
    }
    i = sscanf(s, " %x:%x:%x:%x:%x:%x",
        &t[0], &t[1], &t[2], &t[3], &t[4], &t[5]);
    if (i != 6)
        return ((struct ether_addr *)NULL);
    for (i = 0; i < 6; i++)
        ep->ether_addr_octet[i] = t[i];
    return (ep);
}