Fix SubtreeMIBEntry iter() (sonic-net#33)

There is a bug if query a SubtreeMIBEntry with a short OID, it will not
return the first element in the subtree. For example:

1.3.6.1.2.1.4.24.4.1.1: work
1.3.6.1.2.1.4.24.4.1: not work

src/ax_interface/mib.py

@@ -214,7 +214,7 @@ def __iter__(self):
             sub_id = self.iterator.get_next(sub_id)
             if sub_id is None:
                 break
-            yield self.subtree + sub_id
+            yield sub_id
 
     def __call__(self, sub_id):
         assert isinstance(sub_id, tuple)
@@ -352,7 +352,7 @@ def get_next(self, sr):
 
             val1 = mib_entry(key1)
             if val1 is None:
-                # handler returned None, which implies there's no data, keep walking.
+                logger.error('MIBTable.get_next found an invalid key: {}+{}'.format(mib_entry.subtree, key1))
                 remaining_oids = remaining_oids[1:]
                 continue
 

tests/test_forward.py

@@ -33,6 +33,25 @@ def test_network_order(self):
         ips = ".".join(str(int(x)) for x in list(ipb))
         self.assertEqual(ips, "0.1.2.3")
 
+    def test_getnextpdu_first(self):
+        # oid.include = 1
+        oid = ObjectIdentifier(10, 0, 1, 0, (1, 3, 6, 1, 2, 1, 4, 24, 4, 1))
+        get_pdu = GetNextPDU(
+            header=PDUHeader(1, PduTypes.GET, 16, 0, 42, 0, 0, 0),
+            oids=[oid]
+        )
+
+        encoded = get_pdu.encode()
+        response = get_pdu.make_response(self.lut)
+        print(response)
+
+        n = len(response.values)
+        # self.assertEqual(n, 7)
+        value0 = response.values[0]
+        self.assertEqual(value0.type_, ValueType.IP_ADDRESS)
+        self.assertEqual(str(value0.name), '.1.3.6.1.2.1.4.24.4.1.1.0.0.0.0.0.0.0.0.0.10.0.0.1')
+        self.assertEqual(str(value0.data), ipaddress.ip_address("0.0.0.0").packed.decode())
+
     def test_getpdu(self):
         oid = ObjectIdentifier(24, 0, 1, 0, (1, 3, 6, 1, 2, 1, 4, 24, 4, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 15))
         get_pdu = GetPDU(

tests/test_hc_interfaces.py

@@ -9,8 +9,13 @@
 
 from unittest import TestCase
 
+from ax_interface import ValueType
 from ax_interface.pdu import PDU
 from ax_interface.mib import MIBTable
+from ax_interface.pdu_implementations import GetPDU, GetNextPDU
+from ax_interface.encodings import ObjectIdentifier
+from ax_interface.constants import PduTypes
+from ax_interface.pdu import PDU, PDUHeader
 from sonic_ax_impl.mibs.ietf import rfc2863
 
 
@@ -19,6 +24,25 @@ class TestGetNextPDU(TestCase):
     def setUpClass(cls):
         cls.lut = MIBTable(rfc2863.InterfaceMIBObjects)
 
+    def test_getnextpdu_firstifalias(self):
+        # oid.include = 1
+        oid = ObjectIdentifier(10, 0, 1, 0, (1, 3, 6, 1, 2, 1, 31, 1, 1, 1, 18))
+        get_pdu = GetNextPDU(
+            header=PDUHeader(1, PduTypes.GET, 16, 0, 42, 0, 0, 0),
+            oids=[oid]
+        )
+
+        encoded = get_pdu.encode()
+        response = get_pdu.make_response(self.lut)
+        print(response)
+
+        n = len(response.values)
+        # self.assertEqual(n, 7)
+        value0 = response.values[0]
+        self.assertEqual(value0.type_, ValueType.OCTET_STRING)
+        self.assertEqual(str(value0.name), str(ObjectIdentifier(11, 0, 1, 0, (1, 3, 6, 1, 2, 1, 31, 1, 1, 1, 18, 1))))
+        self.assertEqual(str(value0.data), 'Ethernet0')
+
     def test_get_next_alias(self):
         if_alias = b'\x01\x06\x10\x00\x00\x00\x00o\x00\x01\xcc4\x00\x01\xcc5\x00\x00\x000\x07\x02\x00\x00\x00\x00\x00\x01\x00\x00\x00\x1f\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x11\x00\x00\x00}\x03\x02\x00\x00\x00\x00\x00\x01\x00\x00\x00\x1f\x00\x00\x00\x02'
         pdu = PDU.decode(if_alias)

tests/test_interfaces.py

@@ -38,7 +38,6 @@ def test_getnextpdu_noneifindex(self):
         # self.assertEqual(n, 7)
         value0 = response.values[0]
         self.assertEqual(value0.type_, ValueType.INTEGER)
-        print("test_getnextpdu_exactmatch: ", str(oid))
         self.assertEqual(str(value0.name), str(ObjectIdentifier(11, 0, 1, 0, (1, 3, 6, 1, 2, 1, 2, 2, 1, 1, 1))))
         self.assertEqual(value0.data, 0)
 
@@ -58,7 +57,6 @@ def test_getnextpdu_firstifindex(self):
         # self.assertEqual(n, 7)
         value0 = response.values[0]
         self.assertEqual(value0.type_, ValueType.INTEGER)
-        print("test_getnextpdu_exactmatch: ", str(oid))
         self.assertEqual(str(value0.name), str(ObjectIdentifier(11, 0, 1, 0, (1, 3, 6, 1, 2, 1, 2, 2, 1, 1, 1))))
         self.assertEqual(value0.data, 0)
 
@@ -77,7 +75,6 @@ def test_getnextpdu_secondifindex(self):
         # self.assertEqual(n, 7)
         value0 = response.values[0]
         self.assertEqual(value0.type_, ValueType.INTEGER)
-        print("test_getnextpdu_exactmatch: ", str(oid))
         self.assertEqual(str(value0.name), str(ObjectIdentifier(11, 0, 1, 0, (1, 3, 6, 1, 2, 1, 2, 2, 1, 1, 5))))
         self.assertEqual(value0.data, 4)