xref: /freebsd/sbin/dhclient/inet.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
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  */
55 struct iaddr
56 subnet_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  */
78 struct iaddr
79 broadcast_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 
96 int
97 addr_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 
104 char *
105 piaddr(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