test: cover addrv2 support in anchors.dat with a TorV3 address

Author: pinheadmz

test/functional/feature_anchors.py

@@ -6,12 +6,15 @@
 
 import os
 
-from test_framework.p2p import P2PInterface
+from test_framework.p2p import P2PInterface, P2P_SERVICES
+from test_framework.socks5 import Socks5Configuration, Socks5Server
+from test_framework.messages import CAddress, hash256
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import check_node_connections
+from test_framework.util import check_node_connections, assert_equal, p2p_port
 
 INBOUND_CONNECTIONS = 5
 BLOCK_RELAY_CONNECTIONS = 2
+ONION_ADDR = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion:8333"
 
 
 class AnchorsTest(BitcoinTestFramework):
@@ -54,7 +57,7 @@ def run_test(self):
             else:
                 inbound_nodes_port.append(hex(int(addr_split[1]))[2:])
 
-        self.log.info("Stop node 0")
+        self.log.debug("Stop node")
         self.stop_node(0)
 
         # It should contain only the block-relay-only addresses
@@ -78,12 +81,64 @@ def run_test(self):
                 tweaked_contents[20:20] = b'1'
                 out_file_handler.write(bytes(tweaked_contents))
 
-            self.log.info("Start node")
+            self.log.debug("Start node")
             self.start_node(0)
 
         self.log.info("When node starts, check if anchors.dat doesn't exist anymore")
         assert not os.path.exists(node_anchors_path)
 
+        self.log.info("Ensure addrv2 support")
+        # Use proxies to catch outbound connections to networks with 256-bit addresses
+        onion_conf = Socks5Configuration()
+        onion_conf.auth = True
+        onion_conf.unauth = True
+        onion_conf.addr = ('127.0.0.1', p2p_port(self.num_nodes))
+        onion_conf.keep_alive = True
+        onion_proxy = Socks5Server(onion_conf)
+        onion_proxy.start()
+        self.restart_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
+
+        self.log.info("Add 256-bit-address block-relay-only connections to node")
+        self.nodes[0].addconnection(ONION_ADDR, 'block-relay-only')
+
+        self.log.debug("Stop node")
+        with self.nodes[0].assert_debug_log([f"DumpAnchors: Flush 1 outbound block-relay-only peer addresses to anchors.dat"]):
+            self.stop_node(0)
+        # Manually close keep_alive proxy connection
+        onion_proxy.stop()
+
+        self.log.info("Check for addrv2 addresses in anchors.dat")
+        caddr = CAddress()
+        caddr.net = CAddress.NET_TORV3
+        caddr.ip, port_str = ONION_ADDR.split(":")
+        caddr.port = int(port_str)
+        # TorV3 addrv2 serialization:
+        # time(4) | services(1) | networkID(1) | address length(1) | address(32)
+        expected_pubkey = caddr.serialize_v2()[7:39].hex()
+
+        # position of services byte of first addr in anchors.dat
+        # network magic, vector length, version, nTime
+        services_index = 4 + 1 + 4 + 4
+        data = bytes()
+        with open(node_anchors_path, "rb") as file_handler:
+            data = file_handler.read()
+            assert_equal(data[services_index], 0x00)  # services == NONE
+            anchors2 = data.hex()
+            assert expected_pubkey in anchors2
+
+        with open(node_anchors_path, "wb") as file_handler:
+            # Modify service flags for this address even though we never connected to it.
+            # This is necessary because on restart we will not attempt an anchor connection
+            # to a host without our required services, even if its address is in the anchors.dat file
+            new_data = bytearray(data)[:-32]
+            new_data[services_index] = P2P_SERVICES
+            new_data_hash = hash256(new_data)
+            file_handler.write(new_data + new_data_hash)
+
+        self.log.info("Restarting node attempts to reconnect to anchors")
+        with self.nodes[0].assert_debug_log([f"Trying to make an anchor connection to {ONION_ADDR}"]):
+            self.start_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
+
 
 if __name__ == "__main__":
     AnchorsTest().main()