1 files changed, 95 insertions, 0 deletions
diff --git a/src/libfreeswan/initsubnet.c b/src/libfreeswan/initsubnet.c
new file mode 100644
index 000000000..75ca72f36
--- /dev/null
+++ b/src/libfreeswan/initsubnet.c
@@ -0,0 +1,95 @@
+/*
+ * initialize subnet structure
+ * Copyright (C) 2000, 2002  Henry Spencer.
+ * 
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/lgpl.txt>.
+ * 
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
+ * License for more details.
+ *
+ * RCSID $Id: initsubnet.c,v 1.1 2004/03/15 20:35:26 as Exp $
+ */
+#include "internal.h"
+#include "freeswan.h"
+
+/*
+ - initsubnet - initialize ip_subnet from address and count
+ *
+ * The only hard part is checking for host-part bits turned on.
+ */
+err_t				/* NULL for success, else string literal */
+initsubnet(addr, count, clash, dst)
+const ip_address *addr;
+int count;
+int clash;			/* '0' zero host-part bits, 'x' die on them */
+ip_subnet *dst;
+{
+	unsigned char *p;
+	int n;
+	int c;
+	unsigned m;
+	int die;
+
+	dst->addr = *addr;
+	n = addrbytesptr(&dst->addr, (const unsigned char **)&p);
+	if (n == 0)
+		return "unknown address family";
+
+	switch (clash) {
+	case '0':
+		die = 0;
+		break;
+	case 'x':
+		die = 1;
+		break;
+	default:
+		return "unknown clash-control value in initsubnet";
+		break;
+	}
+
+	c = count / 8;
+	if (c > n)
+		return "impossible mask count";
+	p += c;
+	n -= c;
+
+	m = 0xff;
+	c = count % 8;
+	if (n > 0 && c != 0)	/* partial byte */
+		m >>= c;
+	for (; n > 0; n--) {
+		if ((*p & m) != 0) {
+			if (die)
+				return "improper subnet, host-part bits on";
+			*p &= ~m;
+		}
+		m = 0xff;
+		p++;
+	}
+
+	dst->maskbits = count;
+	return NULL;
+}
+
+/*
+ - addrtosubnet - initialize ip_subnet from a single address
+ */
+err_t				/* NULL for success, else string literal */
+addrtosubnet(addr, dst)
+const ip_address *addr;
+ip_subnet *dst;
+{
+	int n;
+
+	dst->addr = *addr;
+	n = addrbytesptr(&dst->addr, (const unsigned char **)NULL);
+	if (n == 0)
+		return "unknown address family";
+	dst->maskbits = n*8;
+	return NULL;
+}