[tests] Make NodeConnCB a subclass of NodeConn

This makes NodeConnCB a subclass of NodeConn, and
removes the need for the client code to know
anything about the implementation details of NodeConnCB.

NodeConn can now be swapped out for any other implementation
of a low-level connection without changing client code.

14 files changed, 197 insertions, 197 deletions

diff --git a/test/functional/assumevalid.py b/test/functional/assumevalid.py
index 36761d359e..72da955641 100755
--- a/test/functional/assumevalid.py
+++ b/test/functional/assumevalid.py
@@ -67,7 +67,7 @@ class AssumeValidTest(BitcoinTestFramework):
     def send_blocks_until_disconnected(self, p2p_conn):
         """Keep sending blocks to the node until we're disconnected."""
         for i in range(len(self.blocks)):
-            if not p2p_conn.connection:
+            if p2p_conn.state != "connected":
                 break
             try:
                 p2p_conn.send_message(msg_block(self.blocks[i]))
diff --git a/test/functional/bip9-softforks.py b/test/functional/bip9-softforks.py
index 904789301a..ec4d1d9365 100755
--- a/test/functional/bip9-softforks.py
+++ b/test/functional/bip9-softforks.py
@@ -246,7 +246,7 @@ class BIP9SoftForksTest(ComparisonTestFramework):
         self.setup_network()
         self.test.add_all_connections(self.nodes)
         NetworkThread().start()
-        self.test.test_nodes[0].wait_for_verack()
+        self.test.p2p_connections[0].wait_for_verack()
 
     def get_tests(self):
         for test in itertools.chain(
diff --git a/test/functional/example_test.py b/test/functional/example_test.py
index ba40f33016..54cabee51c 100755
--- a/test/functional/example_test.py
+++ b/test/functional/example_test.py
@@ -49,14 +49,14 @@ class BaseNode(NodeConnCB):
         # Stores a dictionary of all blocks received
         self.block_receive_map = defaultdict(int)
 
-    def on_block(self, conn, message):
+    def on_block(self, message):
         """Override the standard on_block callback
 
         Store the hash of a received block in the dictionary."""
         message.block.calc_sha256()
         self.block_receive_map[message.block.sha256] += 1
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         """Override the standard on_inv callback"""
         pass
 
diff --git a/test/functional/maxuploadtarget.py b/test/functional/maxuploadtarget.py
index 88e2ff2e16..beb0d599d2 100755
--- a/test/functional/maxuploadtarget.py
+++ b/test/functional/maxuploadtarget.py
@@ -22,10 +22,10 @@ class TestNode(NodeConnCB):
         super().__init__()
         self.block_receive_map = defaultdict(int)
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         pass
 
-    def on_block(self, conn, message):
+    def on_block(self, message):
         message.block.calc_sha256()
         self.block_receive_map[message.block.sha256] += 1
 
diff --git a/test/functional/p2p-compactblocks.py b/test/functional/p2p-compactblocks.py
index d2c4d39305..5aba1db873 100755
--- a/test/functional/p2p-compactblocks.py
+++ b/test/functional/p2p-compactblocks.py
@@ -25,21 +25,21 @@ class TestNode(NodeConnCB):
         # so we can eg wait until a particular block is announced.
         self.announced_blockhashes = set()
 
-    def on_sendcmpct(self, conn, message):
+    def on_sendcmpct(self, message):
         self.last_sendcmpct.append(message)
 
-    def on_cmpctblock(self, conn, message):
+    def on_cmpctblock(self, message):
         self.block_announced = True
         self.last_message["cmpctblock"].header_and_shortids.header.calc_sha256()
         self.announced_blockhashes.add(self.last_message["cmpctblock"].header_and_shortids.header.sha256)
 
-    def on_headers(self, conn, message):
+    def on_headers(self, message):
         self.block_announced = True
         for x in self.last_message["headers"].headers:
             x.calc_sha256()
             self.announced_blockhashes.add(x.sha256)
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         for x in self.last_message["inv"].inv:
             if x.type == 2:
                 self.block_announced = True
@@ -60,7 +60,7 @@ class TestNode(NodeConnCB):
         msg = msg_getheaders()
         msg.locator.vHave = locator
         msg.hashstop = hashstop
-        self.connection.send_message(msg)
+        self.send_message(msg)
 
     def send_header_for_blocks(self, new_blocks):
         headers_message = msg_headers()
@@ -86,7 +86,7 @@ class TestNode(NodeConnCB):
         This is used when we want to send a message into the node that we expect
         will get us disconnected, eg an invalid block."""
         self.send_message(message)
-        wait_until(lambda: not self.connected, timeout=timeout, lock=mininode_lock)
+        wait_until(lambda: self.state != "connected", timeout=timeout, lock=mininode_lock)
 
 class CompactBlocksTest(BitcoinTestFramework):
     def set_test_params(self):
diff --git a/test/functional/p2p-feefilter.py b/test/functional/p2p-feefilter.py
index 624278df40..0ce3c3f429 100755
--- a/test/functional/p2p-feefilter.py
+++ b/test/functional/p2p-feefilter.py
@@ -27,7 +27,7 @@ class TestNode(NodeConnCB):
         super().__init__()
         self.txinvs = []
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         for i in message.inv:
             if (i.type == 1):
                 self.txinvs.append(hashToHex(i.hash))
diff --git a/test/functional/p2p-leaktests.py b/test/functional/p2p-leaktests.py
index 719a03914d..3634f3836d 100755
--- a/test/functional/p2p-leaktests.py
+++ b/test/functional/p2p-leaktests.py
@@ -30,43 +30,42 @@ class CLazyNode(NodeConnCB):
         self.unexpected_msg = True
         self.log.info("should not have received message: %s" % message.command)
 
-    def on_open(self, conn):
-        self.connected = True
+    def on_open(self):
         self.ever_connected = True
 
-    def on_version(self, conn, message): self.bad_message(message)
-    def on_verack(self, conn, message): self.bad_message(message)
-    def on_reject(self, conn, message): self.bad_message(message)
-    def on_inv(self, conn, message): self.bad_message(message)
-    def on_addr(self, conn, message): self.bad_message(message)
-    def on_getdata(self, conn, message): self.bad_message(message)
-    def on_getblocks(self, conn, message): self.bad_message(message)
-    def on_tx(self, conn, message): self.bad_message(message)
-    def on_block(self, conn, message): self.bad_message(message)
-    def on_getaddr(self, conn, message): self.bad_message(message)
-    def on_headers(self, conn, message): self.bad_message(message)
-    def on_getheaders(self, conn, message): self.bad_message(message)
-    def on_ping(self, conn, message): self.bad_message(message)
-    def on_mempool(self, conn): self.bad_message(message)
-    def on_pong(self, conn, message): self.bad_message(message)
-    def on_feefilter(self, conn, message): self.bad_message(message)
-    def on_sendheaders(self, conn, message): self.bad_message(message)
-    def on_sendcmpct(self, conn, message): self.bad_message(message)
-    def on_cmpctblock(self, conn, message): self.bad_message(message)
-    def on_getblocktxn(self, conn, message): self.bad_message(message)
-    def on_blocktxn(self, conn, message): self.bad_message(message)
+    def on_version(self, message): self.bad_message(message)
+    def on_verack(self, message): self.bad_message(message)
+    def on_reject(self, message): self.bad_message(message)
+    def on_inv(self, message): self.bad_message(message)
+    def on_addr(self, message): self.bad_message(message)
+    def on_getdata(self, message): self.bad_message(message)
+    def on_getblocks(self, message): self.bad_message(message)
+    def on_tx(self, message): self.bad_message(message)
+    def on_block(self, message): self.bad_message(message)
+    def on_getaddr(self, message): self.bad_message(message)
+    def on_headers(self, message): self.bad_message(message)
+    def on_getheaders(self, message): self.bad_message(message)
+    def on_ping(self, message): self.bad_message(message)
+    def on_mempool(self, message): self.bad_message(message)
+    def on_pong(self, message): self.bad_message(message)
+    def on_feefilter(self, message): self.bad_message(message)
+    def on_sendheaders(self, message): self.bad_message(message)
+    def on_sendcmpct(self, message): self.bad_message(message)
+    def on_cmpctblock(self, message): self.bad_message(message)
+    def on_getblocktxn(self, message): self.bad_message(message)
+    def on_blocktxn(self, message): self.bad_message(message)
 
 # Node that never sends a version. We'll use this to send a bunch of messages
 # anyway, and eventually get disconnected.
 class CNodeNoVersionBan(CLazyNode):
     # send a bunch of veracks without sending a message. This should get us disconnected.
     # NOTE: implementation-specific check here. Remove if bitcoind ban behavior changes
-    def on_open(self, conn):
-        super().on_open(conn)
+    def on_open(self):
+        super().on_open()
         for i in range(banscore):
             self.send_message(msg_verack())
 
-    def on_reject(self, conn, message): pass
+    def on_reject(self, message): pass
 
 # Node that never sends a version. This one just sits idle and hopes to receive
 # any message (it shouldn't!)
@@ -80,15 +79,15 @@ class CNodeNoVerackIdle(CLazyNode):
         self.version_received = False
         super().__init__()
 
-    def on_reject(self, conn, message): pass
-    def on_verack(self, conn, message): pass
+    def on_reject(self, message): pass
+    def on_verack(self, message): pass
     # When version is received, don't reply with a verack. Instead, see if the
     # node will give us a message that it shouldn't. This is not an exhaustive
     # list!
-    def on_version(self, conn, message):
+    def on_version(self, message):
         self.version_received = True
-        conn.send_message(msg_ping())
-        conn.send_message(msg_getaddr())
+        self.send_message(msg_ping())
+        self.send_message(msg_getaddr())
 
 class P2PLeakTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -119,11 +118,11 @@ class P2PLeakTest(BitcoinTestFramework):
         time.sleep(5)
 
         #This node should have been banned
-        assert not no_version_bannode.connected
+        assert no_version_bannode.state != "connected"
 
         # These nodes should have been disconnected
-        assert not unsupported_service_bit5_node.connected
-        assert not unsupported_service_bit7_node.connected
+        assert unsupported_service_bit5_node.state != "connected"
+        assert unsupported_service_bit7_node.state != "connected"
 
         self.nodes[0].disconnect_p2ps()
 
diff --git a/test/functional/p2p-segwit.py b/test/functional/p2p-segwit.py
index 586f2d1b79..5776d99f6e 100755
--- a/test/functional/p2p-segwit.py
+++ b/test/functional/p2p-segwit.py
@@ -64,7 +64,7 @@ class TestNode(NodeConnCB):
         super().__init__()
         self.getdataset = set()
 
-    def on_getdata(self, conn, message):
+    def on_getdata(self, message):
         for inv in message.inv:
             self.getdataset.add(inv.hash)
 
@@ -148,7 +148,7 @@ class SegWitTest(BitcoinTestFramework):
     ''' Individual tests '''
     def test_witness_services(self):
         self.log.info("Verifying NODE_WITNESS service bit")
-        assert((self.test_node.connection.nServices & NODE_WITNESS) != 0)
+        assert((self.test_node.nServices & NODE_WITNESS) != 0)
 
 
     # See if sending a regular transaction works, and create a utxo
@@ -1876,11 +1876,11 @@ class SegWitTest(BitcoinTestFramework):
     def run_test(self):
         # Setup the p2p connections and start up the network thread.
         # self.test_node sets NODE_WITNESS|NODE_NETWORK
-        self.test_node = self.nodes[0].add_p2p_connection(p2p_conn=TestNode(), services=NODE_NETWORK|NODE_WITNESS)
+        self.test_node = self.nodes[0].add_p2p_connection(TestNode(), services=NODE_NETWORK|NODE_WITNESS)
         # self.old_node sets only NODE_NETWORK
-        self.old_node = self.nodes[0].add_p2p_connection(p2p_conn=TestNode(), services=NODE_NETWORK)
+        self.old_node = self.nodes[0].add_p2p_connection(TestNode(), services=NODE_NETWORK)
         # self.std_node is for testing node1 (fRequireStandard=true)
-        self.std_node = self.nodes[1].add_p2p_connection(p2p_conn=TestNode(), services=NODE_NETWORK|NODE_WITNESS)
+        self.std_node = self.nodes[1].add_p2p_connection(TestNode(), services=NODE_NETWORK|NODE_WITNESS)
 
         NetworkThread().start() # Start up network handling in another thread
 
diff --git a/test/functional/p2p-timeouts.py b/test/functional/p2p-timeouts.py
index 14a3bf48fb..21ae29eb6a 100755
--- a/test/functional/p2p-timeouts.py
+++ b/test/functional/p2p-timeouts.py
@@ -28,7 +28,7 @@ from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 
 class TestNode(NodeConnCB):
-    def on_version(self, conn, message):
+    def on_version(self, message):
         # Don't send a verack in response
         pass
 
diff --git a/test/functional/p2p-versionbits-warning.py b/test/functional/p2p-versionbits-warning.py
index 464ca5a312..a6265f6d9c 100755
--- a/test/functional/p2p-versionbits-warning.py
+++ b/test/functional/p2p-versionbits-warning.py
@@ -24,7 +24,7 @@ WARN_UNKNOWN_RULES_ACTIVE = "unknown new rules activated (versionbit {})".format
 VB_PATTERN = re.compile("^Warning.*versionbit")
 
 class TestNode(NodeConnCB):
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         pass
 
 class VersionBitsWarningTest(BitcoinTestFramework):
diff --git a/test/functional/sendheaders.py b/test/functional/sendheaders.py
index 68c0d95b4f..b589d0e8a5 100755
--- a/test/functional/sendheaders.py
+++ b/test/functional/sendheaders.py
@@ -113,6 +113,7 @@ DIRECT_FETCH_RESPONSE_TIME = 0.05
 class BaseNode(NodeConnCB):
     def __init__(self):
         super().__init__()
+
         self.block_announced = False
         self.last_blockhash_announced = None
 
@@ -121,18 +122,18 @@ class BaseNode(NodeConnCB):
         msg = msg_getdata()
         for x in block_hashes:
             msg.inv.append(CInv(2, x))
-        self.connection.send_message(msg)
+        self.send_message(msg)
 
     def send_get_headers(self, locator, hashstop):
         msg = msg_getheaders()
         msg.locator.vHave = locator
         msg.hashstop = hashstop
-        self.connection.send_message(msg)
+        self.send_message(msg)
 
     def send_block_inv(self, blockhash):
         msg = msg_inv()
         msg.inv = [CInv(2, blockhash)]
-        self.connection.send_message(msg)
+        self.send_message(msg)
 
     def send_header_for_blocks(self, new_blocks):
         headers_message = msg_headers()
@@ -155,11 +156,11 @@ class BaseNode(NodeConnCB):
         test_function = lambda: self.last_blockhash_announced == block_hash
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         self.block_announced = True
         self.last_blockhash_announced = message.inv[-1].hash
 
-    def on_headers(self, conn, message):
+    def on_headers(self, message):
         if len(message.headers):
             self.block_announced = True
             message.headers[-1].calc_sha256()
diff --git a/test/functional/test_framework/comptool.py b/test/functional/test_framework/comptool.py
index 723826bae4..2f64fba753 100755
--- a/test/functional/test_framework/comptool.py
+++ b/test/functional/test_framework/comptool.py
@@ -43,7 +43,6 @@ class TestNode(NodeConnCB):
 
     def __init__(self, block_store, tx_store):
         super().__init__()
-        self.conn = None
         self.bestblockhash = None
         self.block_store = block_store
         self.block_request_map = {}
@@ -58,26 +57,23 @@ class TestNode(NodeConnCB):
         self.lastInv = []
         self.closed = False
 
-    def on_close(self, conn):
+    def on_close(self):
         self.closed = True
 
-    def add_connection(self, conn):
-        self.conn = conn
-
-    def on_headers(self, conn, message):
+    def on_headers(self, message):
         if len(message.headers) > 0:
             best_header = message.headers[-1]
             best_header.calc_sha256()
             self.bestblockhash = best_header.sha256
 
-    def on_getheaders(self, conn, message):
+    def on_getheaders(self, message):
         response = self.block_store.headers_for(message.locator, message.hashstop)
         if response is not None:
-            conn.send_message(response)
+            self.send_message(response)
 
-    def on_getdata(self, conn, message):
-        [conn.send_message(r) for r in self.block_store.get_blocks(message.inv)]
-        [conn.send_message(r) for r in self.tx_store.get_transactions(message.inv)]
+    def on_getdata(self, message):
+        [self.send_message(r) for r in self.block_store.get_blocks(message.inv)]
+        [self.send_message(r) for r in self.tx_store.get_transactions(message.inv)]
 
         for i in message.inv:
             if i.type == 1 or i.type == 1 | (1 << 30): # MSG_TX or MSG_WITNESS_TX
@@ -85,16 +81,16 @@ class TestNode(NodeConnCB):
             elif i.type == 2 or i.type == 2 | (1 << 30): # MSG_BLOCK or MSG_WITNESS_BLOCK
                 self.block_request_map[i.hash] = True
 
-    def on_inv(self, conn, message):
+    def on_inv(self, message):
         self.lastInv = [x.hash for x in message.inv]
 
-    def on_pong(self, conn, message):
+    def on_pong(self, message):
         try:
             del self.pingMap[message.nonce]
         except KeyError:
             raise AssertionError("Got pong for unknown ping [%s]" % repr(message))
 
-    def on_reject(self, conn, message):
+    def on_reject(self, message):
         if message.message == b'tx':
             self.tx_reject_map[message.data] = RejectResult(message.code, message.reason)
         if message.message == b'block':
@@ -102,30 +98,30 @@ class TestNode(NodeConnCB):
 
     def send_inv(self, obj):
         mtype = 2 if isinstance(obj, CBlock) else 1
-        self.conn.send_message(msg_inv([CInv(mtype, obj.sha256)]))
+        self.send_message(msg_inv([CInv(mtype, obj.sha256)]))
 
     def send_getheaders(self):
         # We ask for headers from their last tip.
         m = msg_getheaders()
         m.locator = self.block_store.get_locator(self.bestblockhash)
-        self.conn.send_message(m)
+        self.send_message(m)
 
     def send_header(self, header):
         m = msg_headers()
         m.headers.append(header)
-        self.conn.send_message(m)
+        self.send_message(m)
 
     # This assumes BIP31
     def send_ping(self, nonce):
         self.pingMap[nonce] = True
-        self.conn.send_message(msg_ping(nonce))
+        self.send_message(msg_ping(nonce))
 
     def received_ping_response(self, nonce):
         return nonce not in self.pingMap
 
     def send_mempool(self):
         self.lastInv = []
-        self.conn.send_message(msg_mempool())
+        self.send_message(msg_mempool())
 
 # TestInstance:
 #
@@ -166,8 +162,7 @@ class TestManager():
 
     def __init__(self, testgen, datadir):
         self.test_generator = testgen
-        self.connections    = []
-        self.test_nodes     = []
+        self.p2p_connections= []
         self.block_store    = BlockStore(datadir)
         self.tx_store       = TxStore(datadir)
         self.ping_counter   = 1
@@ -175,28 +170,24 @@ class TestManager():
     def add_all_connections(self, nodes):
         for i in range(len(nodes)):
             # Create a p2p connection to each node
-            test_node = TestNode(self.block_store, self.tx_store)
-            self.test_nodes.append(test_node)
-            self.connections.append(NodeConn('127.0.0.1', p2p_port(i), test_node))
-            # Make sure the TestNode (callback class) has a reference to its
-            # associated NodeConn
-            test_node.add_connection(self.connections[-1])
+            node = TestNode(self.block_store, self.tx_store)
+            node.peer_connect('127.0.0.1', p2p_port(i))
+            self.p2p_connections.append(node)
 
     def clear_all_connections(self):
-        self.connections    = []
-        self.test_nodes     = []
+        self.p2p_connections = []
 
     def wait_for_disconnections(self):
         def disconnected():
-            return all(node.closed for node in self.test_nodes)
+            return all(node.closed for node in self.p2p_connections)
         wait_until(disconnected, timeout=10, lock=mininode_lock)
 
     def wait_for_verack(self):
-        return all(node.wait_for_verack() for node in self.test_nodes)
+        return all(node.wait_for_verack() for node in self.p2p_connections)
 
     def wait_for_pings(self, counter):
         def received_pongs():
-            return all(node.received_ping_response(counter) for node in self.test_nodes)
+            return all(node.received_ping_response(counter) for node in self.p2p_connections)
         wait_until(received_pongs, lock=mininode_lock)
 
     # sync_blocks: Wait for all connections to request the blockhash given
@@ -206,17 +197,17 @@ class TestManager():
         def blocks_requested():
             return all(
                 blockhash in node.block_request_map and node.block_request_map[blockhash]
-                for node in self.test_nodes
+                for node in self.p2p_connections
             )
 
         # --> error if not requested
         wait_until(blocks_requested, attempts=20*num_blocks, lock=mininode_lock)
 
         # Send getheaders message
-        [ c.cb.send_getheaders() for c in self.connections ]
+        [ c.send_getheaders() for c in self.p2p_connections ]
 
         # Send ping and wait for response -- synchronization hack
-        [ c.cb.send_ping(self.ping_counter) for c in self.connections ]
+        [ c.send_ping(self.ping_counter) for c in self.p2p_connections ]
         self.wait_for_pings(self.ping_counter)
         self.ping_counter += 1
 
@@ -226,42 +217,42 @@ class TestManager():
         def transaction_requested():
             return all(
                 txhash in node.tx_request_map and node.tx_request_map[txhash]
-                for node in self.test_nodes
+                for node in self.p2p_connections
             )
 
         # --> error if not requested
         wait_until(transaction_requested, attempts=20*num_events, lock=mininode_lock)
 
         # Get the mempool
-        [ c.cb.send_mempool() for c in self.connections ]
+        [ c.send_mempool() for c in self.p2p_connections ]
 
         # Send ping and wait for response -- synchronization hack
-        [ c.cb.send_ping(self.ping_counter) for c in self.connections ]
+        [ c.send_ping(self.ping_counter) for c in self.p2p_connections ]
         self.wait_for_pings(self.ping_counter)
         self.ping_counter += 1
 
         # Sort inv responses from each node
         with mininode_lock:
-            [ c.cb.lastInv.sort() for c in self.connections ]
+            [ c.lastInv.sort() for c in self.p2p_connections ]
 
     # Verify that the tip of each connection all agree with each other, and
     # with the expected outcome (if given)
     def check_results(self, blockhash, outcome):
         with mininode_lock:
-            for c in self.connections:
+            for c in self.p2p_connections:
                 if outcome is None:
-                    if c.cb.bestblockhash != self.connections[0].cb.bestblockhash:
+                    if c.bestblockhash != self.p2p_connections[0].bestblockhash:
                         return False
                 elif isinstance(outcome, RejectResult): # Check that block was rejected w/ code
-                    if c.cb.bestblockhash == blockhash:
+                    if c.bestblockhash == blockhash:
                         return False
-                    if blockhash not in c.cb.block_reject_map:
+                    if blockhash not in c.block_reject_map:
                         logger.error('Block not in reject map: %064x' % (blockhash))
                         return False
-                    if not outcome.match(c.cb.block_reject_map[blockhash]):
-                        logger.error('Block rejected with %s instead of expected %s: %064x' % (c.cb.block_reject_map[blockhash], outcome, blockhash))
+                    if not outcome.match(c.block_reject_map[blockhash]):
+                        logger.error('Block rejected with %s instead of expected %s: %064x' % (c.block_reject_map[blockhash], outcome, blockhash))
                         return False
-                elif ((c.cb.bestblockhash == blockhash) != outcome):
+                elif ((c.bestblockhash == blockhash) != outcome):
                     return False
             return True
 
@@ -273,21 +264,21 @@ class TestManager():
     # a particular tx's existence in the mempool is the same across all nodes.
     def check_mempool(self, txhash, outcome):
         with mininode_lock:
-            for c in self.connections:
+            for c in self.p2p_connections:
                 if outcome is None:
                     # Make sure the mempools agree with each other
-                    if c.cb.lastInv != self.connections[0].cb.lastInv:
+                    if c.lastInv != self.p2p_connections[0].lastInv:
                         return False
                 elif isinstance(outcome, RejectResult): # Check that tx was rejected w/ code
-                    if txhash in c.cb.lastInv:
+                    if txhash in c.lastInv:
                         return False
-                    if txhash not in c.cb.tx_reject_map:
+                    if txhash not in c.tx_reject_map:
                         logger.error('Tx not in reject map: %064x' % (txhash))
                         return False
-                    if not outcome.match(c.cb.tx_reject_map[txhash]):
-                        logger.error('Tx rejected with %s instead of expected %s: %064x' % (c.cb.tx_reject_map[txhash], outcome, txhash))
+                    if not outcome.match(c.tx_reject_map[txhash]):
+                        logger.error('Tx rejected with %s instead of expected %s: %064x' % (c.tx_reject_map[txhash], outcome, txhash))
                         return False
-                elif ((txhash in c.cb.lastInv) != outcome):
+                elif ((txhash in c.lastInv) != outcome):
                     return False
             return True
 
@@ -332,25 +323,25 @@ class TestManager():
                         first_block_with_hash = False
                     with mininode_lock:
                         self.block_store.add_block(block)
-                        for c in self.connections:
-                            if first_block_with_hash and block.sha256 in c.cb.block_request_map and c.cb.block_request_map[block.sha256] == True:
+                        for c in self.p2p_connections:
+                            if first_block_with_hash and block.sha256 in c.block_request_map and c.block_request_map[block.sha256] == True:
                                 # There was a previous request for this block hash
                                 # Most likely, we delivered a header for this block
                                 # but never had the block to respond to the getdata
                                 c.send_message(msg_block(block))
                             else:
-                                c.cb.block_request_map[block.sha256] = False
+                                c.block_request_map[block.sha256] = False
                     # Either send inv's to each node and sync, or add
                     # to invqueue for later inv'ing.
                     if (test_instance.sync_every_block):
                         # if we expect success, send inv and sync every block
                         # if we expect failure, just push the block and see what happens.
                         if outcome == True:
-                            [ c.cb.send_inv(block) for c in self.connections ]
+                            [ c.send_inv(block) for c in self.p2p_connections ]
                             self.sync_blocks(block.sha256, 1)
                         else:
-                            [ c.send_message(msg_block(block)) for c in self.connections ]
-                            [ c.cb.send_ping(self.ping_counter) for c in self.connections ]
+                            [ c.send_message(msg_block(block)) for c in self.p2p_connections ]
+                            [ c.send_ping(self.ping_counter) for c in self.p2p_connections ]
                             self.wait_for_pings(self.ping_counter)
                             self.ping_counter += 1
                         if (not self.check_results(tip, outcome)):
@@ -360,7 +351,7 @@ class TestManager():
                 elif isinstance(b_or_t, CBlockHeader):
                     block_header = b_or_t
                     self.block_store.add_header(block_header)
-                    [ c.cb.send_header(block_header) for c in self.connections ]
+                    [ c.send_header(block_header) for c in self.p2p_connections ]
 
                 else:  # Tx test runner
                     assert(isinstance(b_or_t, CTransaction))
@@ -369,11 +360,11 @@ class TestManager():
                     # Add to shared tx store and clear map entry
                     with mininode_lock:
                         self.tx_store.add_transaction(tx)
-                        for c in self.connections:
-                            c.cb.tx_request_map[tx.sha256] = False
+                        for c in self.p2p_connections:
+                            c.tx_request_map[tx.sha256] = False
                     # Again, either inv to all nodes or save for later
                     if (test_instance.sync_every_tx):
-                        [ c.cb.send_inv(tx) for c in self.connections ]
+                        [ c.send_inv(tx) for c in self.p2p_connections ]
                         self.sync_transaction(tx.sha256, 1)
                         if (not self.check_mempool(tx.sha256, outcome)):
                             raise AssertionError("Test failed at test %d" % test_number)
@@ -381,26 +372,26 @@ class TestManager():
                         invqueue.append(CInv(1, tx.sha256))
                 # Ensure we're not overflowing the inv queue
                 if len(invqueue) == MAX_INV_SZ:
-                    [ c.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    [ c.send_message(msg_inv(invqueue)) for c in self.p2p_connections ]
                     invqueue = []
 
             # Do final sync if we weren't syncing on every block or every tx.
             if (not test_instance.sync_every_block and block is not None):
                 if len(invqueue) > 0:
-                    [ c.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    [ c.send_message(msg_inv(invqueue)) for c in self.p2p_connections ]
                     invqueue = []
                 self.sync_blocks(block.sha256, len(test_instance.blocks_and_transactions))
                 if (not self.check_results(tip, block_outcome)):
                     raise AssertionError("Block test failed at test %d" % test_number)
             if (not test_instance.sync_every_tx and tx is not None):
                 if len(invqueue) > 0:
-                    [ c.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    [ c.send_message(msg_inv(invqueue)) for c in self.p2p_connections ]
                     invqueue = []
                 self.sync_transaction(tx.sha256, len(test_instance.blocks_and_transactions))
                 if (not self.check_mempool(tx.sha256, tx_outcome)):
                     raise AssertionError("Mempool test failed at test %d" % test_number)
 
-        [ c.disconnect_node() for c in self.connections ]
+        [ c.disconnect_node() for c in self.p2p_connections ]
         self.wait_for_disconnections()
         self.block_store.close()
         self.tx_store.close()
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index 2b888949f4..09a382c727 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -23,6 +23,7 @@ import sys
 from threading import RLock, Thread
 
 from test_framework.messages import *
+from test_framework.util import wait_until
 
 logger = logging.getLogger("TestFramework.mininode")
 
@@ -57,12 +58,24 @@ MAGIC_BYTES = {
 }
 
 class NodeConn(asyncore.dispatcher):
-    """The actual NodeConn class
+    """A low-level connection object to a node's P2P interface.
 
-    This class provides an interface for a p2p connection to a specified node."""
+    This class is responsible for:
 
-    def __init__(self, dstaddr, dstport, callback, net="regtest", services=NODE_NETWORK|NODE_WITNESS, send_version=True):
-        asyncore.dispatcher.__init__(self, map=mininode_socket_map)
+    - opening and closing the TCP connection to the node
+    - reading bytes from and writing bytes to the socket
+    - deserializing and serializing the P2P message header
+    - logging messages as they are sent and received
+
+    This class contains no logic for handing the P2P message payloads. It must be
+    sub-classed and the on_message() callback overridden.
+
+    TODO: rename this class P2PConnection."""
+
+    def __init__(self):
+        super().__init__(map=mininode_socket_map)
+
+    def peer_connect(self, dstaddr, dstport, net="regtest", services=NODE_NETWORK|NODE_WITNESS, send_version=True):
         self.dstaddr = dstaddr
         self.dstport = dstport
         self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -71,9 +84,7 @@ class NodeConn(asyncore.dispatcher):
         self.recvbuf = b""
         self.state = "connecting"
         self.network = net
-        self.cb = callback
         self.disconnect = False
-        self.nServices = 0
 
         if send_version:
             # stuff version msg into sendbuf
@@ -92,6 +103,11 @@ class NodeConn(asyncore.dispatcher):
         except:
             self.handle_close()
 
+    def peer_disconnect(self):
+        # Connection could have already been closed by other end.
+        if self.state == "connected":
+            self.disconnect_node()
+
     # Connection and disconnection methods
 
     def handle_connect(self):
@@ -99,7 +115,7 @@ class NodeConn(asyncore.dispatcher):
         if self.state != "connected":
             logger.debug("Connected & Listening: %s:%d" % (self.dstaddr, self.dstport))
             self.state = "connected"
-            self.cb.on_open(self)
+            self.on_open()
 
     def handle_close(self):
         """asyncore callback when a connection is closed."""
@@ -111,7 +127,7 @@ class NodeConn(asyncore.dispatcher):
             self.close()
         except:
             pass
-        self.cb.on_close(self)
+        self.on_close()
 
     def disconnect_node(self):
         """Disconnect the p2p connection.
@@ -166,8 +182,8 @@ class NodeConn(asyncore.dispatcher):
             raise
 
     def on_message(self, message):
-        """Callback for processing a P2P payload. Calls into NodeConnCB."""
-        self.cb.on_message(self, message)
+        """Callback for processing a P2P payload. Must be overridden by derived class."""
+        raise NotImplementedError
 
     # Socket write methods
 
@@ -238,15 +254,19 @@ class NodeConn(asyncore.dispatcher):
         logger.debug(log_message)
 
 
-class NodeConnCB():
-    """Callback and helper functions for P2P connection to a bitcoind node.
+class NodeConnCB(NodeConn):
+    """A high-level P2P interface class for communicating with a Bitcoin node.
+
+    This class provides high-level callbacks for processing P2P message
+    payloads, as well as convenience methods for interacting with the
+    node over P2P.
 
     Individual testcases should subclass this and override the on_* methods
-    if they want to alter message handling behaviour."""
+    if they want to alter message handling behaviour.
+
+    TODO: rename this class P2PInterface"""
     def __init__(self):
-        # Track whether we have a P2P connection open to the node
-        self.connected = False
-        self.connection = None
+        super().__init__()
 
         # Track number of messages of each type received and the most recent
         # message of each type
@@ -256,9 +276,12 @@ class NodeConnCB():
         # A count of the number of ping messages we've sent to the node
         self.ping_counter = 1
 
+        # The network services received from the peer
+        self.nServices = 0
+
     # Message receiving methods
 
-    def on_message(self, conn, message):
+    def on_message(self, message):
         """Receive message and dispatch message to appropriate callback.
 
         We keep a count of how many of each message type has been received
@@ -268,66 +291,61 @@ class NodeConnCB():
                 command = message.command.decode('ascii')
                 self.message_count[command] += 1
                 self.last_message[command] = message
-                getattr(self, 'on_' + command)(conn, message)
+                getattr(self, 'on_' + command)(message)
             except:
-                print("ERROR delivering %s (%s)" % (repr(message),
-                                                    sys.exc_info()[0]))
+                print("ERROR delivering %s (%s)" % (repr(message), sys.exc_info()[0]))
                 raise
 
     # Callback methods. Can be overridden by subclasses in individual test
     # cases to provide custom message handling behaviour.
 
-    def on_open(self, conn):
-        self.connected = True
-
-    def on_close(self, conn):
-        self.connected = False
-        self.connection = None
-
-    def on_addr(self, conn, message): pass
-    def on_block(self, conn, message): pass
-    def on_blocktxn(self, conn, message): pass
-    def on_cmpctblock(self, conn, message): pass
-    def on_feefilter(self, conn, message): pass
-    def on_getaddr(self, conn, message): pass
-    def on_getblocks(self, conn, message): pass
-    def on_getblocktxn(self, conn, message): pass
-    def on_getdata(self, conn, message): pass
-    def on_getheaders(self, conn, message): pass
-    def on_headers(self, conn, message): pass
-    def on_mempool(self, conn): pass
-    def on_pong(self, conn, message): pass
-    def on_reject(self, conn, message): pass
-    def on_sendcmpct(self, conn, message): pass
-    def on_sendheaders(self, conn, message): pass
-    def on_tx(self, conn, message): pass
-
-    def on_inv(self, conn, message):
+    def on_open(self):
+        pass
+
+    def on_close(self):
+        pass
+
+    def on_addr(self, message): pass
+    def on_block(self, message): pass
+    def on_blocktxn(self, message): pass
+    def on_cmpctblock(self, message): pass
+    def on_feefilter(self, message): pass
+    def on_getaddr(self, message): pass
+    def on_getblocks(self, message): pass
+    def on_getblocktxn(self, message): pass
+    def on_getdata(self, message): pass
+    def on_getheaders(self, message): pass
+    def on_headers(self, message): pass
+    def on_mempool(self, message): pass
+    def on_pong(self, message): pass
+    def on_reject(self, message): pass
+    def on_sendcmpct(self, message): pass
+    def on_sendheaders(self, message): pass
+    def on_tx(self, message): pass
+
+    def on_inv(self, message):
         want = msg_getdata()
         for i in message.inv:
             if i.type != 0:
                 want.inv.append(i)
         if len(want.inv):
-            conn.send_message(want)
+            self.send_message(want)
 
-    def on_ping(self, conn, message):
-        conn.send_message(msg_pong(message.nonce))
+    def on_ping(self, message):
+        self.send_message(msg_pong(message.nonce))
 
-    def on_verack(self, conn, message):
+    def on_verack(self, message):
         self.verack_received = True
 
-    def on_version(self, conn, message):
+    def on_version(self, message):
         assert message.nVersion >= MIN_VERSION_SUPPORTED, "Version {} received. Test framework only supports versions greater than {}".format(message.nVersion, MIN_VERSION_SUPPORTED)
-        conn.send_message(msg_verack())
-        conn.nServices = message.nServices
+        self.send_message(msg_verack())
+        self.nServices = message.nServices
 
     # Connection helper methods
 
-    def add_connection(self, conn):
-        self.connection = conn
-
     def wait_for_disconnect(self, timeout=60):
-        test_function = lambda: not self.connected
+        test_function = lambda: self.state != "connected"
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
 
     # Message receiving helper methods
@@ -359,12 +377,6 @@ class NodeConnCB():
 
     # Message sending helper functions
 
-    def send_message(self, message):
-        if self.connection:
-            self.connection.send_message(message)
-        else:
-            logger.error("Cannot send message. No connection to node!")
-
     def send_and_ping(self, message):
         self.send_message(message)
         self.sync_with_ping()
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 34b458482a..a9248c764e 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -14,7 +14,6 @@ import subprocess
 import time
 
 from .authproxy import JSONRPCException
-from .mininode import NodeConn
 from .util import (
     assert_equal,
     get_rpc_proxy,
@@ -158,7 +157,7 @@ class TestNode():
         self.encryptwallet(passphrase)
         self.wait_until_stopped()
 
-    def add_p2p_connection(self, p2p_conn, **kwargs):
+    def add_p2p_connection(self, p2p_conn, *args, **kwargs):
         """Add a p2p connection to the node.
 
         This method adds the p2p connection to the self.p2ps list and also
@@ -167,9 +166,9 @@ class TestNode():
             kwargs['dstport'] = p2p_port(self.index)
         if 'dstaddr' not in kwargs:
             kwargs['dstaddr'] = '127.0.0.1'
+
+        p2p_conn.peer_connect(*args, **kwargs)
         self.p2ps.append(p2p_conn)
-        kwargs.update({'callback': p2p_conn})
-        p2p_conn.add_connection(NodeConn(**kwargs))
 
         return p2p_conn
 
@@ -185,10 +184,8 @@ class TestNode():
     def disconnect_p2ps(self):
         """Close all p2p connections to the node."""
         for p in self.p2ps:
-            # Connection could have already been closed by other end.
-            if p.connection is not None:
-                p.connection.disconnect_node()
-        self.p2ps = []
+            p.peer_disconnect()
+        del self.p2ps[:]
 
 
 class TestNodeCLI():