usr/src/lib/libinetutil/common/inetutil.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <unistd.h>
#include <netinet/in.h>
#include <libinetutil.h>

extern int getnetmaskbyaddr(const struct in_addr, struct in_addr *);

/*
 * Internet utility functions.
 */

/*
 * Given a host-order address, calculate client's default net mask.
 * Consult netmasks database to see if net is further subnetted.
 * We'll only snag the first netmask that matches our criteria.
 * We return the resultant netmask in host order.
 */
void
get_netmask4(const struct in_addr *n_addrp, struct in_addr *s_addrp)
{
	struct in_addr	hp, tp;

	/*
	 * First check if VLSM is in use.
	 */
	hp.s_addr = htonl(n_addrp->s_addr);
	if (getnetmaskbyaddr(hp, &tp) == 0) {
		s_addrp->s_addr = ntohl(tp.s_addr);
		return;
	}

	/*
	 * Fall back on standard classed networks.
	 */
	if (IN_CLASSA(n_addrp->s_addr))
		s_addrp->s_addr = IN_CLASSA_NET;
	else if (IN_CLASSB(n_addrp->s_addr))
		s_addrp->s_addr = IN_CLASSB_NET;
	else if (IN_CLASSC(n_addrp->s_addr))
		s_addrp->s_addr = IN_CLASSC_NET;
	else
		s_addrp->s_addr = IN_CLASSE_NET;
}

/*
 * Checks if the IP addresses `ssp1' and `ssp2' are equal.
 */
boolean_t
sockaddrcmp(const struct sockaddr_storage *ssp1,
    const struct sockaddr_storage *ssp2)
{
	struct in_addr addr1, addr2;
	const struct in6_addr *addr6p1, *addr6p2;

	if (ssp1->ss_family != ssp2->ss_family)
		return (B_FALSE);

	if (ssp1 == ssp2)
		return (B_TRUE);

	switch (ssp1->ss_family) {
	case AF_INET:
		addr1 = ((const struct sockaddr_in *)ssp1)->sin_addr;
		addr2 = ((const struct sockaddr_in *)ssp2)->sin_addr;
		return (addr1.s_addr == addr2.s_addr);
	case AF_INET6:
		addr6p1 = &((const struct sockaddr_in6 *)ssp1)->sin6_addr;
		addr6p2 = &((const struct sockaddr_in6 *)ssp2)->sin6_addr;
		return (IN6_ARE_ADDR_EQUAL(addr6p1, addr6p2));
	}
	return (B_FALSE);
}