1/*	$OpenBSD: inet.c,v 1.7 2004/05/04 21:48:16 deraadt Exp $	*/
2
3/*
4 * Subroutines to manipulate internet addresses in a safely portable
5 * way...
6 */
7
8/*-
9 * SPDX-License-Identifier: BSD-3-Clause
10 *
11 * Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of The Internet Software Consortium nor the names
23 *    of its contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
27 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
28 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
30 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
31 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
34 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
35 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
36 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
37 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * This software has been written for the Internet Software Consortium
41 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
42 * Enterprises.  To learn more about the Internet Software Consortium,
43 * see ``http://www.vix.com/isc''.  To learn more about Vixie
44 * Enterprises, see ``http://www.vix.com''.
45 */
46
47#include <sys/cdefs.h>
48__FBSDID("$FreeBSD$");
49
50#include "dhcpd.h"
51
52/*
53 * Return just the network number of an internet address...
54 */
55struct iaddr
56subnet_number(struct iaddr addr, struct iaddr mask)
57{
58	struct iaddr rv;
59	unsigned i;
60
61	rv.len = 0;
62
63	/* Both addresses must have the same length... */
64	if (addr.len != mask.len)
65		return (rv);
66
67	rv.len = addr.len;
68	for (i = 0; i < rv.len; i++)
69		rv.iabuf[i] = addr.iabuf[i] & mask.iabuf[i];
70	return (rv);
71}
72
73/*
74 * Given a subnet number and netmask, return the address on that subnet
75 * for which the host portion of the address is all ones (the standard
76 * broadcast address).
77 */
78struct iaddr
79broadcast_addr(struct iaddr subnet, struct iaddr mask)
80{
81	struct iaddr rv;
82	unsigned i;
83
84	if (subnet.len != mask.len) {
85		rv.len = 0;
86		return (rv);
87	}
88
89	for (i = 0; i < subnet.len; i++)
90		rv.iabuf[i] = subnet.iabuf[i] | (~mask.iabuf[i] & 255);
91	rv.len = subnet.len;
92
93	return (rv);
94}
95
96int
97addr_eq(struct iaddr addr1, struct iaddr addr2)
98{
99	if (addr1.len != addr2.len)
100		return (0);
101	return (memcmp(addr1.iabuf, addr2.iabuf, addr1.len) == 0);
102}
103
104char *
105piaddr(struct iaddr addr)
106{
107	static char pbuf[32];
108	struct in_addr a;
109	char *s;
110
111	memcpy(&a, &(addr.iabuf), sizeof(struct in_addr));
112
113	if (addr.len == 0)
114		strlcpy(pbuf, "<null address>", sizeof(pbuf));
115	else {
116		s = inet_ntoa(a);
117		if (s != NULL)
118			strlcpy(pbuf, s, sizeof(pbuf));
119		else
120			strlcpy(pbuf, "<invalid address>", sizeof(pbuf));
121	}
122	return (pbuf);
123}
124