CORD-1253 Create AddressManager Service

Change-Id: Ibbeec65f3ebec3faadea175480e4b152d66974f9
diff --git a/xos/models.py b/xos/models.py
new file mode 100644
index 0000000..8c07f3c
--- /dev/null
+++ b/xos/models.py
@@ -0,0 +1,103 @@
+
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from core.models import AddressPool
+import os
+from django.db.models import *
+from xos.exceptions import *
+from models_decl import *
+
+class AddressManagerService (AddressManagerService_decl):
+    class Meta:
+        proxy = True
+
+    def ip_to_mac(self, ip):
+        (a, b, c, d) = ip.split('.')
+        return "02:42:%02x:%02x:%02x:%02x" % (int(a), int(b), int(c), int(d))
+
+    def get_gateways(self):
+        gateways = []
+        aps = self.addresspools.all()
+        for ap in aps:
+            gateways.append({"gateway_ip": ap.gateway_ip, "gateway_mac": ap.gateway_mac})
+
+        return gateways
+
+    def get_address_pool(self, name):
+        ap = AddressPool.objects.filter(name=name, service=self)
+        if not ap:
+            raise Exception("Address Manager unable to find addresspool %s" % name)
+        return ap[0]
+
+    def get_service_instance(self, **kwargs):
+        address_pool_name = kwargs.pop("address_pool_name")
+
+        ap = self.get_address_pool(address_pool_name)
+
+        ip = ap.get_address()
+        if not ip:
+            raise Exception("AddressPool '%s' has run out of addresses." % ap.name)
+
+        t = AddressManagerServiceInstance(owner=self, **kwargs)
+        t.public_ip = ip
+        t.public_mac = self.ip_to_mac(ip)
+        t.address_pool_id = ap.id
+        t.save()
+
+        return t
+
+class AddressManagerServiceInstance (AddressManagerServiceInstance_decl):
+
+    class Meta:
+        proxy = True
+
+    @property
+    def gateway_ip(self):
+        if not self.address_pool:
+            return None
+        return self.address_pool.gateway_ip
+
+    @property
+    def gateway_mac(self):
+        if not self.address_pool:
+            return None
+        return self.address_pool.gateway_mac
+
+    @property
+    def cidr(self):
+        if not self.address_pool:
+            return None
+        return self.address_pool.cidr
+
+    @property
+    def netbits(self):
+        # return number of bits in the network portion of the cidr
+        if self.cidr:
+            parts = self.cidr.split("/")
+            if len(parts) == 2:
+                return int(parts[1].strip())
+        return None
+
+    def cleanup_addresspool(self):
+        if self.address_pool:
+            ap = self.address_pool
+            if ap:
+                ap.put_address(self.public_ip)
+                self.public_ip = None
+
+    def delete(self, *args, **kwargs):
+        self.cleanup_addresspool()
+        super(AddressManagerServiceInstance, self).delete(*args, **kwargs)
+