simple-network.configure: Add function to convert mask to cidr suffix

255.255.255.0 -> 24

1 files changed, 7 insertions, 0 deletions

diff --git a/morphlib/exts/simple-network.configure b/morphlib/exts/simple-network.configure
index 258bf7a1..1981dcda 100755
--- a/morphlib/exts/simple-network.configure
+++ b/morphlib/exts/simple-network.configure
@@ -62,6 +62,13 @@ class SimpleNetworkConfigurationExtension(cliapp.Application):
             with open(path, "w") as f:
                 f.write(iface_file)
 
+    def convert_net_mask_to_cidr_suffix(self, mask):
+        """Convert dotted decimal form (255.255.255.0) of a subnet mask to CIDR
+           suffix notation (24)
+        """
+
+        return sum([bin(int(x)).count('1') for x in mask.split('.')])
+
     def generate_iface_file(self, stanza):
         """Generate an interfaces stanza from the provided data."""