X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2FIPUtil.py;h=4b6e2766d892f0c9554da86954ddebad455c7a00;hb=5db24a985316c70a707f2a11b30dd00f7a98dca7;hp=8ad01c491bb00785bdc68efe8c0ec33f201107fd;hpb=8c12ff59f1a5e750151f5eb0e806dcc80e91c3c2;p=csit.git

diff --git a/resources/libraries/python/IPUtil.py b/resources/libraries/python/IPUtil.py
index 8ad01c491b..4b6e2766d8 100644
--- a/resources/libraries/python/IPUtil.py
+++ b/resources/libraries/python/IPUtil.py
@@ -12,6 +12,7 @@
 # limitations under the License.
 
 """Common IP utilities library."""
+from ipaddress import IPv4Network
 
 from resources.libraries.python.ssh import SSH
 from resources.libraries.python.constants import Constants
@@ -40,3 +41,24 @@ class IPUtil(object):
         if int(ret_code) != 0:
             raise Exception('VPP ip probe {dev} {ip} failed on {h}'.format(
                 dev=interface, ip=addr, h=node['host']))
+
+
+def convert_ipv4_netmask_prefix(network):
+    """Convert network mask to equivalent network prefix length or vice versa.
+
+    Example: mask 255.255.0.0 -> prefix length 16
+    :param network: Network mask or network prefix length.
+    :type network: str or int
+    :return: Network mask or network prefix length.
+    :rtype: str or int
+    """
+    temp_address = "0.0.0.0"
+    net = IPv4Network(u"{0}/{1}".format(temp_address, network), False)
+
+    if isinstance(network, int) and (0 < network < 33):
+        return net.netmask
+    elif isinstance(network, basestring):
+        return net.prefixlen
+    else:
+        raise Exception("Value {0} is not a valid ipv4 netmask or network"
+                        " prefix length".format(network))