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