Added a way to handle 4096/4096 and 0

CHANGELOG.rst

@@ -6,6 +6,11 @@ All notable changes to the of_core NApp will be documented in this file.
 [UNRELEASED] - Under development
 ********************************
 
+Changed
+=======
+- ``MatchDLVLAN`` can handle values such as ``"4096/4096"`` and 0
+
+
 [2022.3.1] - 2023-02-23
 ***********************
 

tests/integration/v0x04/test_match.py

@@ -20,3 +20,17 @@ def test_dl_vlan_pyof(self):
         of_tlv = expected.as_of_tlv()
         actual = MatchDLVLAN.from_of_tlv(of_tlv)
         self.assertEqual(expected, actual)
+
+    def test_dl_vlan_mask_pyof(self):
+        """Convert to and from pyog OxmTLV with mask"""
+        expected = MatchDLVLAN("4096/4096")
+        of_tlv = expected.as_of_tlv()
+        actual = MatchDLVLAN.from_of_tlv(of_tlv)
+        self.assertEqual(expected, actual)
+
+    def test_dl_vlan_zero_pyof(self):
+        """Convert to and from pyog OxmTLV with 0"""
+        expected = MatchDLVLAN(0)
+        of_tlv = expected.as_of_tlv()
+        actual = MatchDLVLAN.from_of_tlv(of_tlv)
+        self.assertEqual(expected, actual)

v0x04/match_fields.py

@@ -42,7 +42,10 @@ def as_of_tlv(self):
         except ValueError:
             value, mask = map(int, self.value.split('/'))
             oxm_hasmask = True
-        value = value | VlanId.OFPVID_PRESENT
+        if value == 0:
+            value = VlanId.OFPVID_NONE
+        else:
+            value = value | VlanId.OFPVID_PRESENT
         value_bytes = value.to_bytes(2, 'big')
         if mask:
             mask = mask | VlanId.OFPVID_PRESENT
@@ -53,11 +56,20 @@ def as_of_tlv(self):
 
     @classmethod
     def from_of_tlv(cls, tlv):
-        """Return an instance from a pyof OXM TLV."""
-        vlan_id = int.from_bytes(tlv.oxm_value[:2], 'big') & 4095
+        """Return an instance from a pyof OXM TLV.
+        *oxm_value=0x1000/0x1000 is a valid case. It's necessary to
+        deserialize 0x1000 as 4096 thus it is ignore to not obtain 0
+        """
+        vlan_id = int.from_bytes(tlv.oxm_value[:2], 'big')
+        if vlan_id != 4096:
+            # Ignore 4096
+            vlan_id &= 4095
         value = vlan_id
         if tlv.oxm_hasmask:
-            vlan_mask = int.from_bytes(tlv.oxm_value[2:], 'big') & 4095
+            vlan_mask = int.from_bytes(tlv.oxm_value[2:], 'big')
+            if vlan_mask != 4096:
+                # Ignore 4096
+                vlan_mask &= 4095
             value = f'{vlan_id}/{vlan_mask}'
         return cls(value)