xref: /onnv-gate/usr/src/lib/libbc/libc/net/ether_addr.c (revision 722:636b850d4ee9)

/*
 * 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
 */
/*
 * Copyright 1990 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * 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.
 *
 * Arguments
 *	s:		the string to be parsed
 *	e:		ethernet address struct to be filled in
 *	hostname:	hosts name to be set
 */
int
ether_line(char *s, struct ether_addr *e, char *hostname)
{
	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(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(char *s)
{
	static struct ether_addr *ep;
	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);
}