test: Check that non empty version packet is ignored and no disconnection happens

This test type is represented using SEND_NON_EMPTY_VERSION_PACKET.

Author: stratospher

test/functional/p2p_v2_misbehaving.py

@@ -26,11 +26,13 @@ class TestType(Enum):
     2. EXCESS_GARBAGE - Disconnection happens when > MAX_GARBAGE_LEN bytes garbage is sent
     3. WRONG_GARBAGE_TERMINATOR - Disconnection happens when incorrect garbage terminator is sent
     4. WRONG_GARBAGE - Disconnection happens when garbage bytes that is sent is different from what the peer receives
+    5. SEND_NON_EMPTY_VERSION_PACKET - non-empty version packet is simply ignored
     """
     EARLY_KEY_RESPONSE = 0
     EXCESS_GARBAGE = 1
     WRONG_GARBAGE_TERMINATOR = 2
     WRONG_GARBAGE = 3
+    SEND_NON_EMPTY_VERSION_PACKET = 4
 
 
 class TestEncryptedP2PState(EncryptedP2PState):
@@ -79,9 +81,9 @@ def initiate_v2_handshake(self):
             return super().initiate_v2_handshake()
 
     def complete_handshake(self, response):
-        """Add option for sending wrong garbage terminator. Also option for when
+        """Add option for sending wrong garbage terminator or a non-empty transport version packet. Also option for when
         there's a mismatch between garbage bytes used here vs garbage bytes which were sent out.
-        For TestType = (WRONG_GARBAGE_TERMINATOR, WRONG_GARBAGE)
+        For TestType = (WRONG_GARBAGE_TERMINATOR, WRONG_GARBAGE, SEND_NON_EMPTY_VERSION_PACKET)
         """
         ellswift_theirs = self.received_prefix + response.read(64 - len(self.received_prefix))
         # return b"" if we need to receive more bytes
@@ -102,7 +104,10 @@ def complete_handshake(self, response):
             msg_to_send += self.v2_enc_packet(decoy_content_len * b'\x00', aad=aad, ignore=True)
             aad = b''
         # Send version packet.
-        msg_to_send += self.v2_enc_packet(TRANSPORT_VERSION, aad=aad)
+        if self.test_type == TestType.SEND_NON_EMPTY_VERSION_PACKET:
+            msg_to_send += self.v2_enc_packet(random.randbytes(5), aad=aad)
+        else:
+            msg_to_send += self.v2_enc_packet(TRANSPORT_VERSION, aad=aad)
         return 64 - len(self.received_prefix), msg_to_send
 
 
@@ -165,13 +170,18 @@ def test_v2disconnection(self):
             ["V2 transport error: missing garbage terminator, peer=1"],  # EXCESS_GARBAGE
             ["version handshake timeout peer=2"],  # WRONG_GARBAGE_TERMINATOR
             ["V2 transport error: packet decryption failure"],  # WRONG_GARBAGE
+            [],  # SEND_NON_EMPTY_VERSION_PACKET
         ]
         for test_type in TestType:
             if test_type == TestType.EARLY_KEY_RESPONSE:
                 continue
-            with self.nodes[0].assert_debug_log(expected_debug_message[test_type.value], timeout=5):
-                node0.add_p2p_connection(MisbehavingV2Peer(test_type), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_disconnect=True)
-            self.log.info(f"Expected disconnection for {test_type.name}")
+            elif test_type == TestType.SEND_NON_EMPTY_VERSION_PACKET:
+                node0.add_p2p_connection(MisbehavingV2Peer(test_type), wait_for_verack=True, send_version=True, supports_v2_p2p=True)
+                self.log.info(f"No disconnection for {test_type.name}")
+            else:
+                with self.nodes[0].assert_debug_log(expected_debug_message[test_type.value], timeout=5):
+                    node0.add_p2p_connection(MisbehavingV2Peer(test_type), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_disconnect=True)
+                self.log.info(f"Expected disconnection for {test_type.name}")
 
 
 if __name__ == '__main__':