inet.c revision 147072 
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 * Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of The Internet Software Consortium nor the names
21 *    of its contributors may be used to endorse or promote products derived
22 *    from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
25 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
26 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
28 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
29 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
32 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
33 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
34 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
35 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * This software has been written for the Internet Software Consortium
39 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
40 * Enterprises.  To learn more about the Internet Software Consortium,
41 * see ``http://www.vix.com/isc''.  To learn more about Vixie
42 * Enterprises, see ``http://www.vix.com''.
43 */
44
45#include "dhcpd.h"
46
47/*
48 * Return just the network number of an internet address...
49 */
50struct iaddr
51subnet_number(struct iaddr addr, struct iaddr mask)
52{
53	struct iaddr rv;
54	int i;
55
56	rv.len = 0;
57
58	/* Both addresses must have the same length... */
59	if (addr.len != mask.len)
60		return (rv);
61
62	rv.len = addr.len;
63	for (i = 0; i < rv.len; i++)
64		rv.iabuf[i] = addr.iabuf[i] & mask.iabuf[i];
65	return (rv);
66}
67
68/*
69 * Given a subnet number and netmask, return the address on that subnet
70 * for which the host portion of the address is all ones (the standard
71 * broadcast address).
72 */
73struct iaddr
74broadcast_addr(struct iaddr subnet, struct iaddr mask)
75{
76	struct iaddr rv;
77	int i;
78
79	if (subnet.len != mask.len) {
80		rv.len = 0;
81		return (rv);
82	}
83
84	for (i = 0; i < subnet.len; i++)
85		rv.iabuf[i] = subnet.iabuf[i] | (~mask.iabuf[i] & 255);
86	rv.len = subnet.len;
87
88	return (rv);
89}
90
91int
92addr_eq(struct iaddr addr1, struct iaddr addr2)
93{
94	if (addr1.len != addr2.len)
95		return (0);
96	return (memcmp(addr1.iabuf, addr2.iabuf, addr1.len) == 0);
97}
98
99char *
100piaddr(struct iaddr addr)
101{
102	static char pbuf[32];
103	struct in_addr a;
104	char *s;
105
106	memcpy(&a, &(addr.iabuf), sizeof(struct in_addr));
107
108	if (addr.len == 0)
109		strlcpy(pbuf, "<null address>", sizeof(pbuf));
110	else {
111		s = inet_ntoa(a);
112		if (s != NULL)
113			strlcpy(pbuf, s, sizeof(pbuf));
114		else
115			strlcpy(pbuf, "<invalid address>", sizeof(pbuf));
116	}
117	return (pbuf);
118}
119