SEBA-113 s-tag support for "any" and ranges

Change-Id: Ifcec2c42b16a835338b2e7f703dad0bc31931cfe
diff --git a/xos/synchronizer/models/models.py b/xos/synchronizer/models/models.py
new file mode 100755
index 0000000..75ebe1d
--- /dev/null
+++ b/xos/synchronizer/models/models.py
@@ -0,0 +1,52 @@
+# 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 xos.exceptions import XOSValidationError
+
+from models_decl import FabricCrossconnectService_decl, FabricCrossconnectServiceInstance_decl, BNGPortMapping_decl
+
+class FabricCrossconnectService(FabricCrossconnectService_decl):
+    class Meta:
+        proxy = True
+
+class FabricCrossconnectServiceInstance(FabricCrossconnectServiceInstance_decl):
+   class Meta:
+        proxy = True
+
+class BNGPortMapping(BNGPortMapping_decl):
+    class Meta:
+        proxy = True
+
+    def validate_range(self, pattern):
+        for this_range in pattern.split(","):
+            this_range = this_range.strip()
+            if "-" in this_range:
+                (first, last) = this_range.split("-")
+                try:
+                    int(first.strip())
+                    int(last.strip())
+                except ValueError:
+                    raise XOSValidationError("Malformed range %s" % pattern)
+            elif this_range.lower()=="any":
+                pass
+            else:
+                try:
+                    int(this_range)
+                except ValueError:
+                    raise XOSValidationError("Malformed range %s" % pattern)
+
+    def save(self, *args, **kwargs):
+        self.validate_range(self.s_tag)
+        super(BNGPortMapping, self).save(*args, **kwargs)
+