1  #!/usr/bin/env python3
  2  # Copyright (c) 2020-2021 The Bitcoin Core developers
  3  # Distributed under the MIT software license, see the accompanying
  4  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  5  """Test block-relay-only anchors functionality"""
  6  
  7  import os
  8  
  9  from test_framework.p2p import P2PInterface, P2P_SERVICES
 10  from test_framework.socks5 import Socks5Configuration, Socks5Server
 11  from test_framework.messages import CAddress, hash256
 12  from test_framework.test_framework import BitcoinTestFramework
 13  from test_framework.util import check_node_connections, assert_equal, p2p_port
 14  
 15  INBOUND_CONNECTIONS = 5
 16  BLOCK_RELAY_CONNECTIONS = 2
 17  ONION_ADDR = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion:8333"
 18  
 19  
 20  class AnchorsTest(BitcoinTestFramework):
 21      def set_test_params(self):
 22          self.num_nodes = 1
 23          self.disable_autoconnect = False
 24  
 25      def run_test(self):
 26          node_anchors_path = self.nodes[0].chain_path / "anchors.dat"
 27  
 28          self.log.info("When node starts, check if anchors.dat doesn't exist")
 29          assert not os.path.exists(node_anchors_path)
 30  
 31          self.log.info(f"Add {BLOCK_RELAY_CONNECTIONS} block-relay-only connections to node")
 32          for i in range(BLOCK_RELAY_CONNECTIONS):
 33              self.log.debug(f"block-relay-only: {i}")
 34              self.nodes[0].add_outbound_p2p_connection(
 35                  P2PInterface(), p2p_idx=i, connection_type="block-relay-only"
 36              )
 37  
 38          self.log.info(f"Add {INBOUND_CONNECTIONS} inbound connections to node")
 39          for i in range(INBOUND_CONNECTIONS):
 40              self.log.debug(f"inbound: {i}")
 41              self.nodes[0].add_p2p_connection(P2PInterface())
 42  
 43          self.log.info("Check node connections")
 44          check_node_connections(node=self.nodes[0], num_in=5, num_out=2)
 45  
 46          # 127.0.0.1
 47          ip = "7f000001"
 48  
 49          # Since the ip is always 127.0.0.1 for this case,
 50          # we store only the port to identify the peers
 51          block_relay_nodes_port = []
 52          inbound_nodes_port = []
 53          for p in self.nodes[0].getpeerinfo():
 54              addr_split = p["addr"].split(":")
 55              if p["connection_type"] == "block-relay-only":
 56                  block_relay_nodes_port.append(hex(int(addr_split[1]))[2:])
 57              else:
 58                  inbound_nodes_port.append(hex(int(addr_split[1]))[2:])
 59  
 60          self.log.debug("Stop node")
 61          self.stop_node(0)
 62  
 63          # It should contain only the block-relay-only addresses
 64          self.log.info("Check the addresses in anchors.dat")
 65  
 66          with open(node_anchors_path, "rb") as file_handler:
 67              anchors = file_handler.read()
 68  
 69          anchors_hex = anchors.hex()
 70          for port in block_relay_nodes_port:
 71              ip_port = ip + port
 72              assert ip_port in anchors_hex
 73          for port in inbound_nodes_port:
 74              ip_port = ip + port
 75              assert ip_port not in anchors_hex
 76  
 77          self.log.info("Perturb anchors.dat to test it doesn't throw an error during initialization")
 78          with self.nodes[0].assert_debug_log(["0 block-relay-only anchors will be tried for connections."]):
 79              with open(node_anchors_path, "wb") as out_file_handler:
 80                  tweaked_contents = bytearray(anchors)
 81                  tweaked_contents[20:20] = b'1'
 82                  out_file_handler.write(bytes(tweaked_contents))
 83  
 84              self.log.debug("Start node")
 85              self.start_node(0)
 86  
 87          self.log.info("When node starts, check if anchors.dat doesn't exist anymore")
 88          assert not os.path.exists(node_anchors_path)
 89  
 90          self.log.info("Ensure addrv2 support")
 91          # Use proxies to catch outbound connections to networks with 256-bit addresses
 92          onion_conf = Socks5Configuration()
 93          onion_conf.auth = True
 94          onion_conf.unauth = True
 95          onion_conf.addr = ('127.0.0.1', p2p_port(self.num_nodes))
 96          onion_conf.keep_alive = True
 97          onion_proxy = Socks5Server(onion_conf)
 98          onion_proxy.start()
 99          self.restart_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
100  
101          self.log.info("Add 256-bit-address block-relay-only connections to node")
102          self.nodes[0].addconnection(ONION_ADDR, 'block-relay-only', v2transport=False)
103  
104          self.log.debug("Stop node")
105          with self.nodes[0].assert_debug_log([f"DumpAnchors: Flush 1 outbound block-relay-only peer addresses to anchors.dat"]):
106              self.stop_node(0)
107          # Manually close keep_alive proxy connection
108          onion_proxy.stop()
109  
110          self.log.info("Check for addrv2 addresses in anchors.dat")
111          caddr = CAddress()
112          caddr.net = CAddress.NET_TORV3
113          caddr.ip, port_str = ONION_ADDR.split(":")
114          caddr.port = int(port_str)
115          # TorV3 addrv2 serialization:
116          # time(4) | services(1) | networkID(1) | address length(1) | address(32)
117          expected_pubkey = caddr.serialize_v2()[7:39].hex()
118  
119          # position of services byte of first addr in anchors.dat
120          # network magic, vector length, version, nTime
121          services_index = 4 + 1 + 4 + 4
122          data = bytes()
123          with open(node_anchors_path, "rb") as file_handler:
124              data = file_handler.read()
125              assert_equal(data[services_index], 0x00)  # services == NONE
126              anchors2 = data.hex()
127              assert expected_pubkey in anchors2
128  
129          with open(node_anchors_path, "wb") as file_handler:
130              # Modify service flags for this address even though we never connected to it.
131              # This is necessary because on restart we will not attempt an anchor connection
132              # to a host without our required services, even if its address is in the anchors.dat file
133              new_data = bytearray(data)[:-32]
134              new_data[services_index] = P2P_SERVICES
135              new_data_hash = hash256(new_data)
136              file_handler.write(new_data + new_data_hash)
137  
138          self.log.info("Restarting node attempts to reconnect to anchors")
139          with self.nodes[0].assert_debug_log([f"Trying to make an anchor connection to {ONION_ADDR}"]):
140              self.start_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
141  
142  
143  if __name__ == "__main__":
144      AnchorsTest().main()