qa: Add p2p_invalid_locator test

Adds a custom mininode implementation to test connects and
disconnects based on the number of allowed locators

Inspired by: fa85c985
Original Author: MarcoFalke <falke.marco@gmail.com>

qa/pull-tester/rpc-tests.py

@@ -128,6 +128,7 @@ testScripts = [
     'rawtransactions.py',
     'reindex.py',
     # vv Tests less than 30s vv
+    'p2p_invalid_locator.py',
     'mempool_resurrect_test.py',
     'txn_doublespend.py --mineblock',
     'txn_clone.py',

qa/rpc-tests/p2p_invalid_locator.py

@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+# Copyright (c) 2015-2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""
+Test node responses to invalid locators.
+"""
+
+from test_framework.mininode import *
+from test_framework.util import *
+from test_framework.test_framework import BitcoinTestFramework
+
+class TestNode(SingleNodeConnCB):
+    def __init__(self):
+        SingleNodeConnCB.__init__(self)
+        self.last_headers = None
+        self.last_block = None
+        self.last_header_received = None
+
+    def on_block(self, conn, message):
+        self.last_block = message.block
+        self.last_block.calc_sha256()
+
+    def on_headers(self, conn, message):
+        self.last_headers = message
+        if len(message.headers):
+            message.headers[-1].calc_sha256()
+            self.last_header_received = message.headers[-1]
+
+    def on_close(self, conn):
+        self.disconnected = True
+
+    def wait_for_verack(self):
+        while True:
+            with mininode_lock:
+                if self.verack_received:
+                    return
+            time.sleep(0.05)
+
+    def wait_for_block(self, blockhash, timeout=60):
+        test_function = lambda: self.last_block != None and self.last_block.sha256 == blockhash
+        assert(wait_until(test_function, timeout=timeout))
+        return
+
+    def wait_for_header(self, blockhash, timeout=60):
+        test_function = lambda: self.last_header_received != None and self.last_header_received.sha256 == blockhash
+        assert(wait_until(test_function, timeout=timeout))
+        return
+
+    # wait for the socket to be in a closed state
+    def wait_for_disconnect(self, timeout=60):
+        if self.connection == None:
+            return True
+        sleep_time = 0.05
+        is_closed = self.connection.state == "closed"
+        while not is_closed and timeout > 0:
+            time.sleep(sleep_time)
+            timeout -= sleep_time
+            is_closed = self.connection.state == "closed"
+        return is_closed
+
+
+class InvalidLocatorTest(BitcoinTestFramework):
+    def __init__(self):
+        self.num_nodes = 1
+        self.setup_clean_chain = False
+        self.connections = []
+        self.test_nodes = []
+
+    def setup_network(self):
+        self.nodes = []
+        self.nodes.append(start_node(0, self.options.tmpdir, ["-debug=net"]))
+
+        for i in range(4):
+            self.test_nodes.append(TestNode())
+            self.connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], self.test_nodes[i]))
+            self.test_nodes[i].add_connection(self.connections[i])
+
+        NetworkThread().start()
+
+    def run_test(self):
+        node = self.nodes[0]  # convenience reference to the node
+        node.generate(1)  # Get node out of IBD
+
+        # Test max locator size
+        block_count = node.getblockcount()
+        for msg in [msg_getheaders(), msg_getblocks()]:
+            # Wait for disconnect when sending MAX_LOCATOR_SZ + 1 (102) hashes in locator
+            test_node = self.test_nodes.pop()
+            test_node.wait_for_verack()
+            msg.locator.vHave = [int(node.getblockhash(i - 1), 16) for i in range(block_count, block_count - (MAX_LOCATOR_SZ + 1), -1)]
+            test_node.connection.send_message(msg)
+            assert_equal(test_node.wait_for_disconnect(), True)
+
+            # Wait for response when sending MAX_LOCATOR_SZ (101) hashes in locator
+            test_node = self.test_nodes.pop()
+            test_node.wait_for_verack()
+            msg.locator.vHave = [int(node.getblockhash(i - 1), 16) for i in range(block_count, block_count - (MAX_LOCATOR_SZ), -1)]
+            test_node.connection.send_message(msg)
+            if type(msg) == msg_getheaders:
+                test_node.wait_for_header(int(node.getbestblockhash(), 16))
+            else:
+                test_node.wait_for_block(int(node.getbestblockhash(), 16))
+
+        [ c.disconnect_node() for c in self.connections ]
+
+if __name__ == '__main__':
+    InvalidLocatorTest().main()

qa/rpc-tests/test_framework/mininode.py

@@ -45,6 +45,7 @@ MY_SUBVERSION = b"/python-mininode-tester:0.0.3/"
 MY_RELAY = 1 # from version 70001 onwards, fRelay should be appended to version messages (BIP37)
 
 MAX_INV_SZ = 50000
+MAX_LOCATOR_SZ = 101
 MAX_BLOCK_BASE_SIZE = 1000000
 
 COIN = 100000000 # mlumin 5/2021: In terms of Dogecoin, 1 dogecoin or 100,000,000 koinu.