More portable internet addresses; fix endian bug; fix parser bugs

common/inet.c

@@ -0,0 +1,154 @@
+/* inet.c
+
+   Subroutines to manipulate internet addresses in a safely portable
+   way... */
+
+/*
+ * Copyright (c) 1995 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 (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;
+	unsigned long host_address;
+{
+	int i, j, k;
+	unsigned long 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]) {
+				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;
+		}
+		rv.iabuf [i + j] = habuf [i];
+	}
+		
+	return rv;
+}
+
+unsigned long host_addr (addr, mask)
+	struct iaddr addr;
+	struct iaddr mask;
+{
+	int i;
+	unsigned long 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;
+}