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 #include "dhcpd.h"
49
50 /*
51 * Return just the network number of an internet address...
52 */
53 struct iaddr
subnet_number(struct iaddr addr,struct iaddr mask)54 subnet_number(struct iaddr addr, struct iaddr mask)
55 {
56 struct iaddr rv;
57 unsigned i;
58
59 rv.len = 0;
60
61 /* Both addresses must have the same length... */
62 if (addr.len != mask.len)
63 return (rv);
64
65 rv.len = addr.len;
66 for (i = 0; i < rv.len; i++)
67 rv.iabuf[i] = addr.iabuf[i] & mask.iabuf[i];
68 return (rv);
69 }
70
71 /*
72 * Given a subnet number and netmask, return the address on that subnet
73 * for which the host portion of the address is all ones (the standard
74 * broadcast address).
75 */
76 struct iaddr
broadcast_addr(struct iaddr subnet,struct iaddr mask)77 broadcast_addr(struct iaddr subnet, struct iaddr mask)
78 {
79 struct iaddr rv;
80 unsigned i;
81
82 if (subnet.len != mask.len) {
83 rv.len = 0;
84 return (rv);
85 }
86
87 for (i = 0; i < subnet.len; i++)
88 rv.iabuf[i] = subnet.iabuf[i] | (~mask.iabuf[i] & 255);
89 rv.len = subnet.len;
90
91 return (rv);
92 }
93
94 int
addr_eq(struct iaddr addr1,struct iaddr addr2)95 addr_eq(struct iaddr addr1, struct iaddr addr2)
96 {
97 if (addr1.len != addr2.len)
98 return (0);
99 return (memcmp(addr1.iabuf, addr2.iabuf, addr1.len) == 0);
100 }
101
102 char *
piaddr(struct iaddr addr)103 piaddr(struct iaddr addr)
104 {
105 static char pbuf[32];
106 struct in_addr a;
107 char *s;
108
109 memcpy(&a, &(addr.iabuf), sizeof(struct in_addr));
110
111 if (addr.len == 0)
112 strlcpy(pbuf, "<null address>", sizeof(pbuf));
113 else {
114 s = inet_ntoa(a);
115 if (s != NULL)
116 strlcpy(pbuf, s, sizeof(pbuf));
117 else
118 strlcpy(pbuf, "<invalid address>", sizeof(pbuf));
119 }
120 return (pbuf);
121 }
122