/* $OpenBSD: inet.c,v 1.5 2004/09/16 21:27:44 claudio Exp $ */ /* * Subroutines to manipulate internet addresses in a safely portable * way... */ /* * Copyright (c) 1996 The Internet Software Consortium. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of The Internet Software Consortium nor the names * of its contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * This software has been written for the Internet Software Consortium * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie * Enterprises. To learn more about the Internet Software Consortium, * see ``http://www.vix.com/isc''. To learn more about Vixie * Enterprises, see ``http://www.vix.com''. */ #include "dhcpd.h" /* * Return just the network number of an internet address... */ struct iaddr subnet_number(struct iaddr addr, struct iaddr mask) { struct iaddr rv; int i; rv.len = 0; /* Both addresses must have the same length... */ if (addr.len != mask.len) return (rv); rv.len = addr.len; for (i = 0; i < rv.len; i++) rv.iabuf[i] = addr.iabuf[i] & mask.iabuf[i]; return (rv); } /* * Combine a network number and a integer to produce an internet address. * This won't work for subnets with more than 32 bits of host address, but * maybe this isn't a problem. */ struct iaddr ip_addr(struct iaddr subnet, struct iaddr mask, u_int32_t host_address) { int i, j, k; u_int32_t swaddr; unsigned char habuf[sizeof(swaddr)]; struct iaddr rv; swaddr = htonl(host_address); memcpy(habuf, &swaddr, sizeof(swaddr)); /* * Combine the subnet address and the host address. If the * host address is bigger than can fit in the subnet, return a * zero-length iaddr structure. */ rv = subnet; j = rv.len - sizeof(habuf); for (i = sizeof(habuf) - 1; i >= 0; i--) { if (mask.iabuf[i + j]) { if (habuf[i] > (mask.iabuf[i + j] ^ 0xFF)) { rv.len = 0; return (rv); } for (k = i - 1; k >= 0; k--) if (habuf[k]) { rv.len = 0; return (rv); } rv.iabuf[i + j] |= habuf[i]; break; } else rv.iabuf[i + j] = habuf[i]; } return (rv); } u_int32_t host_addr(struct iaddr addr, struct iaddr mask) { int i; u_int32_t swaddr; struct iaddr rv; rv.len = 0; /* Mask out the network bits... */ rv.len = addr.len; for (i = 0; i < rv.len; i++) rv.iabuf[i] = addr.iabuf[i] & ~mask.iabuf[i]; /* Copy out up to 32 bits... */ memcpy(&swaddr, &rv.iabuf[rv.len - sizeof(swaddr)], sizeof(swaddr)); /* Swap it and return it. */ return (ntohl(swaddr)); } int addr_eq(struct iaddr addr1, struct iaddr addr2) { if (addr1.len != addr2.len) return (0); return (memcmp(addr1.iabuf, addr2.iabuf, addr1.len) == 0); } char * piaddr(struct iaddr addr) { static char pbuf[32]; const char *s; if (addr.len == 0) strlcpy(pbuf, "<null address>", sizeof(pbuf)); else { s = inet_ntop(AF_INET, &addr.iabuf, pbuf, sizeof pbuf); if (s == NULL) strlcpy(pbuf, "<invalid address>", sizeof(pbuf)); } return (pbuf); }