/* inet.c Subroutines to manipulate internet addresses in a safely portable way... */ /* * Copyright (c) 1995-1999 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 in cooperation with Vixie Enterprises and Nominum, Inc. * To learn more about the Internet Software Consortium, see * ``http://www.isc.org/''. To learn more about Vixie Enterprises, * see ``http://www.vix.com''. To learn more about Nominum, Inc., see * ``http://www.nominum.com''. */ #ifndef lint static char copyright[] = "$Id: inet.c,v 1.1.1.5 2000/04/22 07:11:34 mellon Exp $ Copyright (c) 1995-1999 The Internet Software Consortium. All rights reserved.\n"; #endif /* not lint */ #include "dhcpd.h" /* Return just the network number of an internet address... */ struct iaddr subnet_number (addr, mask) struct iaddr addr; struct iaddr mask; { int i; struct iaddr rv; 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 (subnet, mask, host_address) struct iaddr subnet; struct iaddr mask; u_int32_t host_address; { int i, j, k; u_int32_t swaddr; struct iaddr rv; unsigned char habuf [sizeof swaddr]; 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; } /* Given a subnet number and netmask, return the address on that subnet for which the host portion of the address is all ones (the standard broadcast address). */ struct iaddr broadcast_addr (subnet, mask) struct iaddr subnet; struct iaddr mask; { int i, j, k; struct iaddr rv; if (subnet.len != mask.len) { rv.len = 0; return rv; } for (i = 0; i < subnet.len; i++) { rv.iabuf [i] = subnet.iabuf [i] | (~mask.iabuf [i] & 255); } rv.len = subnet.len; return rv; } u_int32_t host_addr (addr, mask) 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 (addr1, addr2) struct iaddr addr1, addr2; { if (addr1.len != addr2.len) return 0; return memcmp (addr1.iabuf, addr2.iabuf, addr1.len) == 0; } char *piaddr (addr) struct iaddr addr; { static char pbuf [4 * 16]; char *s = pbuf; int i; if (addr.len == 0) { strcpy (s, ""); } for (i = 0; i < addr.len; i++) { sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]); s += strlen (s); } return pbuf; }