xref: /freebsd/sbin/dhclient/inet.c (revision 24bd614bbdda9cf8065489d0c6c3ea469c9c4392)
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  */
50 struct iaddr
51 subnet_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  */
73 struct iaddr
74 broadcast_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 
91 int
92 addr_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 
99 char *
100 piaddr(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