Handle setting of first IP in IP range in SMF and UPF config file

upf/ip_utils.py

@@ -0,0 +1,71 @@
+# BSD 2-Clause License
+
+# Copyright (c) 2020, Supreeth Herle
+# 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.
+
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
+
+import click
+import sys
+import ipaddress
+
+"""
+Script used to fetch first IP address in a given IP range. i.e. the calling bash script reads the std output
+
+Usage in command line:
+e.g:
+$ python3 ip_utils.py --ip_range 192.168.100.0/24
+$ python3 ip_utils.py --ip_range 2001:230:cafe::/48
+"""
+
+
+def validate_ip_net(ctx, param, value):
+    try:
+        ip_net = ipaddress.ip_network(value)
+        return ip_net
+    except ValueError:
+        raise click.BadParameter(
+            'Value does not represent a valid IPv4/IPv6 range')
+
+
+@click.command()
+@click.option('--ip_range',
+              required=True,
+              callback=validate_ip_net,
+              help='UE IPv4/IPv6 Address range in CIDR format e.g. 192.168.100.0/24 or 2001:230:cafe::/48')
+def start(ip_range):
+
+    # Get the first IP address in the IP range and netmask prefix length
+    first_ip_addr = next(ip_range.hosts(), None)
+    if not first_ip_addr:
+        raise ValueError('Invalid UE IPv4 range. Only one IP given')
+    else:
+        first_ip_addr = first_ip_addr.exploded
+        ip_netmask_prefix = ip_range.prefixlen
+        print(str(first_ip_addr) + '/' + str(ip_netmask_prefix))
+
+if __name__ == '__main__':
+    try:
+        start()
+        sys.exit(0)
+    except ValueError:
+        sys.exit(1)