ipv4.c

/* ipv4.c
 *
 * IPv4 address class. They understand how to take netmasks into consideration
 * during equivalence testing.
 *
 * Gilbert Ramirez <gram@xiexie.org>
 *
 * $Id: ipv4.c,v 1.4 1999/11/19 23:01:13 gram Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@unicom.net>
 * Copyright 1998 Gerald Combs
 *
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

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

#include <glib.h>
#include <stdio.h>

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

#include "ipv4.h"
#include "packet.h" /* for ip_to_str */

static guint32 create_nmask(gint net_bits);

ipv4_addr*
ipv4_addr_new(void)
{
	ipv4_addr	*ipv4;

	ipv4 = g_new(ipv4_addr, 1);
	return ipv4;
}

void
ipv4_addr_free(ipv4_addr *ipv4)
{
	if (ipv4)
		g_free(ipv4);
}

void
ipv4_addr_set_host_order_addr(ipv4_addr *ipv4, guint32 new_addr)
{
	ipv4->addr = new_addr;
}

void
ipv4_addr_set_net_order_addr(ipv4_addr *ipv4, guint32 new_addr)
{
	ipv4->addr = ntohl(new_addr);
}

void
ipv4_addr_set_netmask_bits(ipv4_addr *ipv4, guint new_nmask_bits)
{
/*	ipv4->nmask_bits = new_nmask_bits;*/
	ipv4->nmask = create_nmask(new_nmask_bits);
}

guint32
ipv4_get_net_order_addr(ipv4_addr *ipv4)
{
	return htonl(ipv4->addr);
}

guint32
ipv4_get_host_order_addr(ipv4_addr *ipv4)
{
	return ipv4->addr;
}

gchar*
ipv4_addr_str(ipv4_addr *ipv4)
{
	guint32	ipv4_host_order = htonl(ipv4->addr);
	return ip_to_str((gchar*)&ipv4_host_order);
}

static guint32
create_nmask(gint net_bits)
{
	static guint32 bitmasks[33] = {
		0x00000000,
		0x80000000, 0xc0000000, 0xe0000000, 0xf0000000,
		0xf8000000, 0xfc000000, 0xfe000000, 0xff000000,
		0xff800000, 0xffc00000, 0xffe00000, 0xfff00000,
		0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000,
		0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000,
		0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00,
		0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0,
		0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff,
	};

	g_assert(net_bits <= 32);

	return bitmasks[net_bits];
}



/*
 * w.x.y.z/32 eq w.x.y.0/24    TRUE
 */

/* Returns TRUE if equal, FALSE if not */
gboolean
ipv4_addr_eq(ipv4_addr *a, ipv4_addr *b)
{
	guint32	val_a, val_b, nmask;

	nmask = MIN(a->nmask, b->nmask);
	val_a = a->addr & nmask;
	val_b = b->addr & nmask;
	return (val_a == val_b);
}

gboolean
ipv4_addr_gt(ipv4_addr *a, ipv4_addr *b)
{
	guint32	val_a, val_b, nmask;

	nmask = MIN(a->nmask, b->nmask);
	val_a = a->addr & nmask;
	val_b = b->addr & nmask;

	return (val_a > val_b);
}

gboolean
ipv4_addr_ge(ipv4_addr *a, ipv4_addr *b)
{
	guint32	val_a, val_b, nmask;

	nmask = MIN(a->nmask, b->nmask);
	val_a = a->addr & nmask;
	val_b = b->addr & nmask;

	return (val_a >= val_b);
}

gboolean
ipv4_addr_lt(ipv4_addr *a, ipv4_addr *b)
{
	guint32	val_a, val_b, nmask;

	nmask = MIN(a->nmask, b->nmask);
	val_a = a->addr & nmask;
	val_b = b->addr & nmask;

	return (val_a < val_b);
}

gboolean
ipv4_addr_le(ipv4_addr *a, ipv4_addr *b)
{
	guint32	val_a, val_b, nmask;

	nmask = MIN(a->nmask, b->nmask);
	val_a = a->addr & nmask;
	val_b = b->addr & nmask;

	return (val_a <= val_b);
}