243 lines
6.0 KiB
C
243 lines
6.0 KiB
C
/* inet.c
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Subroutines to manipulate internet addresses in a safely portable
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way... */
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/*
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* Copyright (c) 1995-2001 Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
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* To learn more about the Internet Software Consortium, see
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* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
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* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
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* ``http://www.nominum.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: inet.c,v 1.8.2.3 2001/06/21 16:59:00 mellon Exp $ Copyright (c) 1995-1999 The Internet Software Consortium. All rights reserved.\n";
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#endif /* not lint */
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#include "dhcpd.h"
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/* Return just the network number of an internet address... */
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struct iaddr subnet_number (addr, mask)
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struct iaddr addr;
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struct iaddr mask;
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{
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int i;
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struct iaddr rv;
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rv.len = 0;
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/* Both addresses must have the same length... */
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if (addr.len != mask.len)
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return rv;
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rv.len = addr.len;
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for (i = 0; i < rv.len; i++)
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rv.iabuf [i] = addr.iabuf [i] & mask.iabuf [i];
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return rv;
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}
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/* Combine a network number and a integer to produce an internet address.
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This won't work for subnets with more than 32 bits of host address, but
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maybe this isn't a problem. */
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struct iaddr ip_addr (subnet, mask, host_address)
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struct iaddr subnet;
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struct iaddr mask;
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u_int32_t host_address;
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{
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int i, j, k;
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u_int32_t swaddr;
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struct iaddr rv;
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unsigned char habuf [sizeof swaddr];
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swaddr = htonl (host_address);
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memcpy (habuf, &swaddr, sizeof swaddr);
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/* Combine the subnet address and the host address. If
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the host address is bigger than can fit in the subnet,
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return a zero-length iaddr structure. */
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rv = subnet;
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j = rv.len - sizeof habuf;
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for (i = sizeof habuf - 1; i >= 0; i--) {
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if (mask.iabuf [i + j]) {
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if (habuf [i] > (mask.iabuf [i + j] ^ 0xFF)) {
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rv.len = 0;
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return rv;
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}
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for (k = i - 1; k >= 0; k--) {
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if (habuf [k]) {
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rv.len = 0;
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return rv;
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}
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}
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rv.iabuf [i + j] |= habuf [i];
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break;
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} else
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rv.iabuf [i + j] = habuf [i];
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}
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return rv;
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}
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/* Given a subnet number and netmask, return the address on that subnet
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for which the host portion of the address is all ones (the standard
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broadcast address). */
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struct iaddr broadcast_addr (subnet, mask)
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struct iaddr subnet;
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struct iaddr mask;
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{
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int i, j, k;
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struct iaddr rv;
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if (subnet.len != mask.len) {
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rv.len = 0;
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return rv;
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}
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for (i = 0; i < subnet.len; i++) {
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rv.iabuf [i] = subnet.iabuf [i] | (~mask.iabuf [i] & 255);
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}
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rv.len = subnet.len;
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return rv;
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}
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u_int32_t host_addr (addr, mask)
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struct iaddr addr;
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struct iaddr mask;
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{
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int i;
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u_int32_t swaddr;
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struct iaddr rv;
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rv.len = 0;
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/* Mask out the network bits... */
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rv.len = addr.len;
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for (i = 0; i < rv.len; i++)
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rv.iabuf [i] = addr.iabuf [i] & ~mask.iabuf [i];
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/* Copy out up to 32 bits... */
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memcpy (&swaddr, &rv.iabuf [rv.len - sizeof swaddr], sizeof swaddr);
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/* Swap it and return it. */
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return ntohl (swaddr);
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}
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int addr_eq (addr1, addr2)
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struct iaddr addr1, addr2;
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{
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if (addr1.len != addr2.len)
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return 0;
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return memcmp (addr1.iabuf, addr2.iabuf, addr1.len) == 0;
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}
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char *piaddr (addr)
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struct iaddr addr;
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{
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static char pbuf [4 * 16];
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char *s = pbuf;
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int i;
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if (addr.len == 0) {
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strcpy (s, "<null address>");
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}
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for (i = 0; i < addr.len; i++) {
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sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
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s += strlen (s);
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}
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return pbuf;
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}
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char *piaddr1 (addr)
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struct iaddr addr;
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{
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static char pbuf [4 * 16];
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char *s = pbuf;
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int i;
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if (addr.len == 0) {
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strcpy (s, "<null address>");
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}
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for (i = 0; i < addr.len; i++) {
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sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
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s += strlen (s);
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}
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return pbuf;
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}
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char *piaddrmask (struct iaddr addr, struct iaddr mask,
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const char *file, int line)
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{
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char *s, *t;
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int i, mw;
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unsigned len;
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for (i = 0; i < 32; i++) {
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if (!mask.iabuf [3 - i / 8])
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i += 7;
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else if (mask.iabuf [3 - i / 8] & (1 << (i % 8)))
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break;
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}
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mw = 32 - i;
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len = mw > 9 ? 2 : 1;
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len += 4; /* three dots and a slash. */
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for (i = 0; i < (mw / 8) + 1; i++) {
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if (addr.iabuf [i] > 99)
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len += 3;
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else if (addr.iabuf [i] > 9)
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len += 2;
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else
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len++;
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}
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s = dmalloc (len + 1, file, line);
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if (!s)
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return s;
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t = s;
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sprintf (t, "%d", addr.iabuf [0]);
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t += strlen (t);
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for (i = 1; i < (mw / 8) + 1; i++) {
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sprintf (t, ".%d", addr.iabuf [i]);
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t += strlen (t);
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}
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*t++ = '/';
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sprintf (t, "%d", mw);
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return s;
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}
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