[Fix] Overlapping stored flows

CHANGELOG.rst

@@ -21,6 +21,13 @@ Removed
 Security
 ========
 
+[5.1.0] - 2021-11.08
+********************
+
+Added
+=====
+- Augmented ``_add_flow_store`` to overwrite overlapping flows
+
 [5.0.0] - 2021-11.05
 ********************
 

kytos.json

@@ -3,7 +3,7 @@
   "username": "kytos",
   "name": "flow_manager",
   "description": "Manage switches' flows through a REST API.",
-  "version": "5.0.0",
+  "version": "5.1.0",
   "napp_dependencies": ["kytos/of_core", "kytos/storehouse"],
   "license": "MIT",
   "url": "https://github.com/kytos/flow_manager.git",

main.py

@@ -314,9 +314,8 @@ def _del_matched_flows_store(self, flow_dict, switch):
             del stored_flows_box["id"]
             self.stored_flows = deepcopy(stored_flows_box)
 
-    # pylint: disable=fixme
     def _add_flow_store(self, flow_dict, switch):
-        """Try to add a flow dict in the store."""
+        """Try to add a flow dict in the store idempotently."""
         installed_flow = {}
         installed_flow["flow"] = flow_dict
         installed_flow["created_at"] = now().strftime("%Y-%m-%dT%H:%M:%S")
@@ -326,11 +325,23 @@ def _add_flow_store(self, flow_dict, switch):
         if switch.id not in stored_flows_box:
             stored_flows_box[switch.id] = OrderedDict()
 
-        # TODO handle issue 23 (overlapping FlowMod add)
         if not stored_flows_box[switch.id].get(cookie):
             stored_flows_box[switch.id][cookie] = [installed_flow]
         else:
-            stored_flows_box[switch.id][cookie].append(installed_flow)
+            version = switch.connection.protocol.version
+            stored_flows = stored_flows_box[switch.id].get(cookie, [])
+            for i, stored_flow in enumerate(stored_flows):
+                if all(
+                    (
+                        stored_flow["flow"].get("priority", 0)
+                        == flow_dict.get("priority", 0),
+                        match_flow(flow_dict, version, stored_flow["flow"]),
+                    )
+                ):
+                    stored_flows_box[switch.id][cookie][i] = installed_flow
+                    break
+            else:
+                stored_flows_box[switch.id][cookie].append(installed_flow)
 
         stored_flows_box["id"] = "flow_persistence"
         self.storehouse.save_flow(stored_flows_box)

setup.py

@@ -24,7 +24,7 @@
 BASE_ENV = Path(os.environ.get("VIRTUAL_ENV", "/"))
 
 NAPP_NAME = "flow_manager"
-NAPP_VERSION = "5.0.0"
+NAPP_VERSION = "5.1.0"
 
 # Kytos var folder
 VAR_PATH = BASE_ENV / "var" / "lib" / "kytos"

tests/unit/test_main.py

@@ -2,6 +2,9 @@
 from unittest import TestCase
 from unittest.mock import MagicMock, patch
 
+# pylint: disable=too-many-lines,fixme
+# TODO split this test suite in smaller ones
+
 from kytos.core.helpers import now
 from kytos.lib.helpers import (
     get_connection_mock,
@@ -405,6 +408,89 @@ def test_check_switch_consistency_add(self, *args):
         self.napp.check_switch_consistency(switch)
         mock_install_flows.assert_called()
 
+    @patch("napps.kytos.flow_manager.storehouse.StoreHouse.save_flow")
+    def test_add_overlapping_flow(self, *args):
+        """Test add an overlapping flow."""
+        (_,) = args
+        dpid = "00:00:00:00:00:00:00:01"
+        switch = get_switch_mock(dpid, 0x04)
+        switch.id = dpid
+        cookie = 0x20
+
+        self.napp.stored_flows = {
+            dpid: {
+                cookie: [
+                    {
+                        "flow": {
+                            "priority": 10,
+                            "cookie": 84114904,
+                            "match": {
+                                "ipv4_src": "192.168.1.1",
+                                "ipv4_dst": "192.168.0.2",
+                            },
+                            "actions": [{"action_type": "output", "port": 2}],
+                        }
+                    }
+                ]
+            }
+        }
+
+        new_actions = [{"action_type": "output", "port": 3}]
+        flow_dict = {
+            "priority": 10,
+            "cookie": cookie,
+            "match": {
+                "ipv4_src": "192.168.1.1",
+                "ipv4_dst": "192.168.0.2",
+            },
+            "actions": new_actions,
+        }
+
+        self.napp._add_flow_store(flow_dict, switch)
+        assert len(self.napp.stored_flows[dpid]) == 1
+        assert self.napp.stored_flows[dpid][0x20][0]["flow"]["actions"] == new_actions
+
+    @patch("napps.kytos.flow_manager.storehouse.StoreHouse.save_flow")
+    def test_add_overlapping_flow_diff_priority(self, *args):
+        """Test that a different priority wouldn't overlap."""
+        (_,) = args
+        dpid = "00:00:00:00:00:00:00:01"
+        switch = get_switch_mock(dpid, 0x04)
+        switch.id = dpid
+
+        cookie = 0x20
+        self.napp.stored_flows = {
+            dpid: {
+                cookie: [
+                    {
+                        "flow": {
+                            "priority": 10,
+                            "cookie": 84114904,
+                            "match": {
+                                "ipv4_src": "192.168.1.1",
+                                "ipv4_dst": "192.168.0.2",
+                            },
+                            "actions": [{"action_type": "output", "port": 2}],
+                        }
+                    }
+                ]
+            }
+        }
+
+        new_actions = [{"action_type": "output", "port": 3}]
+        flow_dict = {
+            "priority": 11,
+            "cookie": cookie,
+            "match": {
+                "ipv4_src": "192.168.1.1",
+                "ipv4_dst": "192.168.0.2",
+            },
+            "actions": new_actions,
+        }
+
+        self.napp._add_flow_store(flow_dict, switch)
+        assert len(self.napp.stored_flows[dpid][cookie]) == 2
+
     @patch("napps.kytos.flow_manager.main.Main._install_flows")
     @patch("napps.kytos.flow_manager.main.FlowFactory.get_class")
     def test_check_switch_flow_not_missing(self, *args):