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 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 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 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 * 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