Add test program for netmask and prefixlen conversion

2 files changed, 67 insertions, 1 deletions

diff --git a/tools/Makefile.am b/tools/Makefile.am
index 407811c4..bafb4762 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -1,6 +1,6 @@
 
 if TOOLS
-noinst_PROGRAMS = wifi-scan tap-test
+noinst_PROGRAMS = wifi-scan tap-test addr-test
 
 wifi_scan_LDADD = @GLIB_LIBS@ @NETLINK_LIBS@
 endif
diff --git a/tools/addr-test.c b/tools/addr-test.c
new file mode 100644
index 00000000..44364204
--- /dev/null
+++ b/tools/addr-test.c
@@ -0,0 +1,66 @@
+/*
+ *
+ *  Connection Manager
+ *
+ *  Copyright (C) 2007-2009  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <arpa/inet.h>
+
+static unsigned char netmask2prefixlen(const char *netmask)
+{
+	unsigned char bits = 0;
+	in_addr_t mask = inet_network(netmask);
+	in_addr_t host = ~mask;
+
+	/* a valid netmask must be 2^n - 1 */
+	if ((host & (host + 1)) != 0)
+		return -1;
+
+	for (; mask; mask <<= 1)
+		++bits;
+
+	return bits;
+}
+
+int main(int argc, char *argv[])
+{
+	const char *masks[] = { "255.255.255.255", "255.255.255.0",
+						"255.255.0.0", "255.0.0.0" };
+	struct in_addr addr;
+	int i, len;
+
+	for (i = 0; i < 4; i++) {
+		printf("subnet %-16s  prefixlen %u\n", masks[i],
+						netmask2prefixlen(masks[i]));
+	}
+
+	printf("\n");
+
+	for (i = 0; i < 4; i++) {
+		len = (i + 1) * 8;
+		addr.s_addr = htonl(~(0xfffffffflu >> len));
+		printf("prefixlen %-2u  netmask %s\n", len, inet_ntoa(addr));
+	}
+
+	return 0;
+}