freebsd-nq/contrib/isc-dhcp/common/inet.c
2004-06-26 10:34:24 +00:00

234 lines
5.4 KiB
C

/* inet.c
Subroutines to manipulate internet addresses in a safely portable
way... */
/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1995-2003 by Internet Software Consortium
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Internet Systems Consortium, Inc.
* 950 Charter Street
* Redwood City, CA 94063
* <info@isc.org>
* http://www.isc.org/
*
* This software has been written for Internet Systems Consortium
* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about Internet Systems 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 1.8.2.5 2004/06/10 17:59:18 dhankins Exp $ Copyright (c) 2004 Internet Systems 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, "<null address>");
}
for (i = 0; i < addr.len; i++) {
sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
s += strlen (s);
}
return pbuf;
}
char *piaddr1 (addr)
struct iaddr addr;
{
static char pbuf [4 * 16];
char *s = pbuf;
int i;
if (addr.len == 0) {
strcpy (s, "<null address>");
}
for (i = 0; i < addr.len; i++) {
sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
s += strlen (s);
}
return pbuf;
}
char *piaddrmask (struct iaddr addr, struct iaddr mask,
const char *file, int line)
{
char *s, *t;
int i, mw;
unsigned len;
for (i = 0; i < 32; i++) {
if (!mask.iabuf [3 - i / 8])
i += 7;
else if (mask.iabuf [3 - i / 8] & (1 << (i % 8)))
break;
}
mw = 32 - i;
len = mw > 9 ? 2 : 1;
len += 4; /* three dots and a slash. */
for (i = 0; i < (mw / 8) + 1; i++) {
if (addr.iabuf [i] > 99)
len += 3;
else if (addr.iabuf [i] > 9)
len += 2;
else
len++;
}
s = dmalloc (len + 1, file, line);
if (!s)
return s;
t = s;
sprintf (t, "%d", addr.iabuf [0]);
t += strlen (t);
for (i = 1; i < (mw / 8) + 1; i++) {
sprintf (t, ".%d", addr.iabuf [i]);
t += strlen (t);
}
*t++ = '/';
sprintf (t, "%d", mw);
return s;
}