text: #!/usr/bin/env python3
  # Copyright (c) 2010 ArtForz -- public domain half-a-node
  # Copyright (c) 2012 Jeff Garzik
  # Copyright (c) 2010-2016 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Mgc P2P network half-a-node.
  
  This python code was modified from ArtForz' public domain half-a-node, as
  found in the mini-node branch of http://github.com/jgarzik/pynode.
  
  P2PConnection: A low-level connection object to a node's P2P interface
  P2PInterface: A high-level interface object for communicating to a node over P2P
  P2PDataStore: A p2p interface class that keeps a store of transactions and blocks
                and can respond correctly to getdata and getheaders messages
  """
  import asyncore
  from collections import defaultdict
  from io import BytesIO
  import logging
  import socket
  import struct
  import sys
  import threading
  
  from test_framework.messages import *
  from test_framework.util import wait_until
  
  MSG_TX = 1
  MSG_BLOCK = 2
  MSG_TYPE_MASK = 0xffffffff >> 2
  
  logger = logging.getLogger("TestFramework.mininode")
  
  MESSAGEMAP = {
      b"addr": msg_addr,
      b"block": msg_block,
      b"blocktxn": msg_blocktxn,
      b"cmpctblock": msg_cmpctblock,
      b"getaddr": msg_getaddr,
      b"getblocks": msg_getblocks,
      b"getblocktxn": msg_getblocktxn,
      b"getdata": msg_getdata,
      b"getheaders": msg_getheaders,
      b"headers": msg_headers,
      b"inv": msg_inv,
      b"mempool": msg_mempool,
      b"ping": msg_ping,
      b"pong": msg_pong,
      b"reject": msg_reject,
      b"sendcmpct": msg_sendcmpct,
      b"sendheaders": msg_sendheaders,
      b"tx": msg_tx,
      b"verack": msg_verack,
      b"version": msg_version,
      # Mgc Specific
      b"clsig": msg_clsig,
      b"getmnlistd": msg_getmnlistd,
      b"getsporks": None,
      b"govsync": None,
      b"islock": msg_islock,
      b"mnlistdiff": msg_mnlistdiff,
      b"notfound": None,
      b"qfcommit": None,
      b"qsendrecsigs": None,
      b"qgetdata": msg_qgetdata,
      b"qdata": msg_qdata,
      b"qwatch" : None,
      b"senddsq": None,
      b"spork": None,
  }
  
  MAGIC_BYTES = {
      "mainnet": b"\xbf\x0c\x6b\xbd",   # mainnet
      "testnet3": b"\xce\xe2\xca\xff",  # testnet3
      "regtest": b"\xfc\xc1\xb7\xdc",   # regtest
      "devnet": b"\xe2\xca\xff\xce",    # devnet
  }
  
  class P2PConnection(asyncore.dispatcher):
      """A low-level connection object to a node's P2P interface.
  
      This class is responsible for:
  
      - 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."""
  
      def __init__(self):
          super().__init__(map=mininode_socket_map)
  
          self._conn_open = False
  
      @property
      def is_connected(self):
          return self._conn_open
  
      def peer_connect(self, dstaddr, dstport, *, net, devnet_name=None, uacomment=None):
          self.dstaddr = dstaddr
          self.dstport = dstport
          self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
          self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
          self.sendbuf = b""
          self.recvbuf = b""
          self._asyncore_pre_connection = True
          self.network = net
          self.devnet_name = devnet_name
          self.uacomment = uacomment
          self.disconnect = False
  
          if self.network == "devnet" and self.devnet_name is not None:
              if self.uacomment is None:
                  self.strSubVer = MY_SUBVERSION % ("(devnet=devnet-%s)" % self.devnet_name).encode()
              else:
                  self.strSubVer = MY_SUBVERSION % ("(devnet=devnet-%s,%s)" % (self.devnet_name, self.uacomment)).encode()
          elif self.uacomment is not None:
              self.strSubVer = MY_SUBVERSION % ("(%s)" % self.uacomment).encode()
          else:
              self.strSubVer = MY_SUBVERSION % b""
  
          logger.debug('Connecting to Mgc Node: %s:%d' % (self.dstaddr, self.dstport))
  
          try:
              self.connect((dstaddr, dstport))
          except:
              self.handle_close()
  
      def peer_disconnect(self):
          # Connection could have already been closed by other end.
          if self.is_connected:
              self.disconnect = True  # Signal asyncore to disconnect
  
      # Connection and disconnection methods
  
      def handle_connect(self):
          """asyncore callback when a connection is opened."""
          if not self.is_connected:
              logger.debug("Connected & Listening: %s:%d" % (self.dstaddr, self.dstport))
              self._conn_open = True
              self._asyncore_pre_connection = False
              self.on_open()
  
      def handle_close(self):
          """asyncore callback when a connection is closed."""
          logger.debug("Closing connection to: %s:%d" % (self.dstaddr, self.dstport))
          self._conn_open = False
          self.recvbuf = b""
          self.sendbuf = b""
          try:
              self.close()
          except:
              pass
          self.on_close()
  
      # Socket read methods
  
      def handle_read(self):
          """asyncore callback when data is read from the socket."""
          t = self.recv(8192)
          if len(t) > 0:
              self.recvbuf += t
              self._on_data()
  
      def _on_data(self):
          """Try to read P2P messages from the recv buffer.
  
          This method reads data from the buffer in a loop. It deserializes,
          parses and verifies the P2P header, then passes the P2P payload to
          the on_message callback for processing."""
          try:
              while True:
                  if len(self.recvbuf) < 4:
                      return
                  if self.recvbuf[:4] != MAGIC_BYTES[self.network]:
                      raise ValueError("got garbage %s" % repr(self.recvbuf))
                  if len(self.recvbuf) < 4 + 12 + 4 + 4:
                      return
                  command = self.recvbuf[4:4+12].split(b"\x00", 1)[0]
                  msglen = struct.unpack("<i", self.recvbuf[4+12:4+12+4])[0]
                  checksum = self.recvbuf[4+12+4:4+12+4+4]
                  if len(self.recvbuf) < 4 + 12 + 4 + 4 + msglen:
                      return
                  msg = self.recvbuf[4+12+4+4:4+12+4+4+msglen]
                  th = sha256(msg)
                  h = sha256(th)
                  if checksum != h[:4]:
                      raise ValueError("got bad checksum " + repr(self.recvbuf))
                  self.recvbuf = self.recvbuf[4+12+4+4+msglen:]
                  if command not in MESSAGEMAP:
                      raise ValueError("Received unknown command from %s:%d: '%s' %s" % (self.dstaddr, self.dstport, command, repr(msg)))
                  if MESSAGEMAP[command] is None:
                      # Command is known but we don't want/need to handle it
                      continue
                  f = BytesIO(msg)
                  t = MESSAGEMAP[command]()
                  t.deserialize(f)
                  self._log_message("receive", t)
                  self.on_message(t)
          except Exception as e:
              logger.exception('Error reading message:', repr(e))
              raise
  
      def on_message(self, message):
          """Callback for processing a P2P payload. Must be overridden by derived class."""
          raise NotImplementedError
  
      # Socket write methods
  
      def writable(self):
          """asyncore method to determine whether the handle_write() callback should be called on the next loop."""
          with mininode_lock:
              length = len(self.sendbuf)
          return length > 0 or self._asyncore_pre_connection
  
      def handle_write(self):
          """asyncore callback when data should be written to the socket."""
          with mininode_lock:
              # asyncore does not expose socket connection, only the first read/write
              # event, thus we must check connection manually here to know when we
              # actually connect
              if self._asyncore_pre_connection:
                  self.handle_connect()
              if not self.writable():
                  return
  
              try:
                  sent = self.send(self.sendbuf)
              except:
                  self.handle_close()
                  return
              self.sendbuf = self.sendbuf[sent:]
  
      def send_message(self, message):
          """Send a P2P message over the socket.
  
          This method takes a P2P payload, builds the P2P header and adds
          the message to the send buffer to be sent over the socket."""
          if not self.is_connected:
              raise IOError('Not connected')
          self._log_message("send", message)
          tmsg = self._build_message(message)
          with mininode_lock:
              if len(self.sendbuf) == 0:
                  try:
                      sent = self.send(tmsg)
                      self.sendbuf = tmsg[sent:]
                  except BlockingIOError:
                      self.sendbuf = tmsg
              else:
                  self.sendbuf += tmsg
  
      # Class utility methods
  
      def _build_message(self, message):
          """Build a serialized P2P message"""
          command = message.command
          data = message.serialize()
          tmsg = MAGIC_BYTES[self.network]
          tmsg += command
          tmsg += b"\x00" * (12 - len(command))
          tmsg += struct.pack("<I", len(data))
          th = sha256(data)
          h = sha256(th)
          tmsg += h[:4]
          tmsg += data
          return tmsg
  
      def _log_message(self, direction, msg):
          """Logs a message being sent or received over the connection."""
          if direction == "send":
              log_message = "Send message to "
          elif direction == "receive":
              log_message = "Received message from "
          log_message += "%s:%d: %s" % (self.dstaddr, self.dstport, repr(msg)[:500])
          if len(log_message) > 500:
              log_message += "... (msg truncated)"
          logger.debug(log_message)
  
  
  class P2PInterface(P2PConnection):
      """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."""
      def __init__(self):
          super().__init__()
  
          # Track number of messages of each type received and the most recent
          # message of each type
          self.message_count = defaultdict(int)
          self.last_message = {}
  
          # 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
  
      def peer_connect(self, *args, services=NODE_NETWORK, send_version=True, **kwargs):
          super().peer_connect(*args, **kwargs)
  
          if send_version:
              # Send a version msg
              vt = msg_version()
              vt.nServices = services
              vt.addrTo.ip = self.dstaddr
              vt.addrTo.port = self.dstport
              vt.addrFrom.ip = "0.0.0.0"
              vt.addrFrom.port = 0
              vt.strSubVer = self.strSubVer
              self.sendbuf = self._build_message(vt)  # Will be sent right after handle_connect
  
      # Message receiving methods
  
      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
          and the most recent message of each type."""
          with mininode_lock:
              try:
                  command = message.command.decode('ascii')
                  self.message_count[command] += 1
                  self.last_message[command] = message
                  getattr(self, 'on_' + command)(message)
              except:
                  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):
          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):
              self.send_message(want)
  
      def on_ping(self, message):
          self.send_message(msg_pong(message.nonce))
  
      def on_mnlistdiff(self, message): pass
      def on_clsig(self, message): pass
      def on_islock(self, message): pass
  
      def on_qgetdata(self, message): pass
      def on_qdata(self, message): pass
      def on_qwatch(self, message): pass
  
      def on_verack(self, message):
          self.verack_received = True
  
      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)
          self.send_message(msg_verack())
          self.nServices = message.nServices
  
      # Connection helper methods
  
      def wait_for_disconnect(self, timeout=60):
          test_function = lambda: not self.is_connected
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
          # This is a hack. The related issues should be fixed by bitcoin 14119 and 14457.
          time.sleep(1)
  
      # Message receiving helper methods
  
      def wait_for_block(self, blockhash, timeout=60):
          test_function = lambda: self.last_message.get("block") and self.last_message["block"].block.rehash() == blockhash
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
  
      def wait_for_getdata(self, timeout=60):
          """Waits for a getdata message.
  
          Receiving any getdata message will satisfy the predicate. the last_message["getdata"]
          value must be explicitly cleared before calling this method, or this will return
          immediately with success. TODO: change this method to take a hash value and only
          return true if the correct block/tx has been requested."""
          test_function = lambda: self.last_message.get("getdata")
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
  
      def wait_for_getheaders(self, timeout=60):
          """Waits for a getheaders message.
  
          Receiving any getheaders message will satisfy the predicate. the last_message["getheaders"]
          value must be explicitly cleared before calling this method, or this will return
          immediately with success. TODO: change this method to take a hash value and only
          return true if the correct block header has been requested."""
          test_function = lambda: self.last_message.get("getheaders")
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
  
      def wait_for_inv(self, expected_inv, timeout=60):
          """Waits for an INV message and checks that the first inv object in the message was as expected."""
          if len(expected_inv) > 1:
              raise NotImplementedError("wait_for_inv() will only verify the first inv object")
          test_function = lambda: self.last_message.get("inv") and \
                                  self.last_message["inv"].inv[0].type == expected_inv[0].type and \
                                  self.last_message["inv"].inv[0].hash == expected_inv[0].hash
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
  
      def wait_for_verack(self, timeout=60):
          test_function = lambda: self.message_count["verack"]
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
  
      # Message sending helper functions
  
      def send_and_ping(self, message):
          self.send_message(message)
          self.sync_with_ping()
  
      # Sync up with the node
      def sync_with_ping(self, timeout=60):
          self.send_message(msg_ping(nonce=self.ping_counter))
          test_function = lambda: self.last_message.get("pong") and self.last_message["pong"].nonce == self.ping_counter
          wait_until(test_function, timeout=timeout, lock=mininode_lock)
          self.ping_counter += 1
  
  
  # Keep our own socket map for asyncore, so that we can track disconnects
  # ourselves (to work around an issue with closing an asyncore socket when
  # using select)
  mininode_socket_map = dict()
  
  # One lock for synchronizing all data access between the networking thread (see
  # NetworkThread below) and the thread running the test logic.  For simplicity,
  # P2PConnection acquires this lock whenever delivering a message to a P2PInterface,
  # and whenever adding anything to the send buffer (in send_message()).  This
  # lock should be acquired in the thread running the test logic to synchronize
  # access to any data shared with the P2PInterface or P2PConnection.
  mininode_lock = threading.RLock()
  
  class NetworkThread(threading.Thread):
      def __init__(self):
          super().__init__(name="NetworkThread")
  
      def run(self):
          while mininode_socket_map:
              # We check for whether to disconnect outside of the asyncore
              # loop to work around the behavior of asyncore when using
              # select
              disconnected = []
              for fd, obj in mininode_socket_map.items():
                  if obj.disconnect:
                      disconnected.append(obj)
              [obj.handle_close() for obj in disconnected]
              asyncore.loop(0.1, use_poll=True, map=mininode_socket_map, count=1)
          logger.debug("Network thread closing")
  
  def network_thread_start():
      """Start the network thread."""
      # Only one network thread may run at a time
      assert not network_thread_running()
  
      NetworkThread().start()
  
  def network_thread_running():
      """Return whether the network thread is running."""
      return any([thread.name == "NetworkThread" for thread in threading.enumerate()])
  
  def network_thread_join(timeout=10):
      """Wait timeout seconds for the network thread to terminate.
  
      Throw if the network thread doesn't terminate in timeout seconds."""
      network_threads = [thread for thread in threading.enumerate() if thread.name == "NetworkThread"]
      assert len(network_threads) <= 1
      for thread in network_threads:
          thread.join(timeout)
          assert not thread.is_alive()
  
  class P2PDataStore(P2PInterface):
      """A P2P data store class.
  
      Keeps a block and transaction store and responds correctly to getdata and getheaders requests."""
  
      def __init__(self):
          super().__init__()
          self.reject_code_received = None
          self.reject_reason_received = None
          # store of blocks. key is block hash, value is a CBlock object
          self.block_store = {}
          self.last_block_hash = ''
          # store of txs. key is txid, value is a CTransaction object
          self.tx_store = {}
          self.getdata_requests = []
  
      def on_getdata(self, message):
          """Check for the tx/block in our stores and if found, reply with an inv message."""
          for inv in message.inv:
              self.getdata_requests.append(inv.hash)
              if (inv.type & MSG_TYPE_MASK) == MSG_TX and inv.hash in self.tx_store.keys():
                  self.send_message(msg_tx(self.tx_store[inv.hash]))
              elif (inv.type & MSG_TYPE_MASK) == MSG_BLOCK and inv.hash in self.block_store.keys():
                  self.send_message(msg_block(self.block_store[inv.hash]))
              else:
                  logger.debug('getdata message type {} received.'.format(hex(inv.type)))
  
      def on_getheaders(self, message):
          """Search back through our block store for the locator, and reply with a headers message if found."""
  
          locator, hash_stop = message.locator, message.hashstop
  
          # Assume that the most recent block added is the tip
          if not self.block_store:
              return
  
          headers_list = [self.block_store[self.last_block_hash]]
          maxheaders = 2000
          while headers_list[-1].sha256 not in locator.vHave:
              # Walk back through the block store, adding headers to headers_list
              # as we go.
              prev_block_hash = headers_list[-1].hashPrevBlock
              if prev_block_hash in self.block_store:
                  prev_block_header = CBlockHeader(self.block_store[prev_block_hash])
                  headers_list.append(prev_block_header)
                  if prev_block_header.sha256 == hash_stop:
                      # if this is the hashstop header, stop here
                      break
              else:
                  logger.debug('block hash {} not found in block store'.format(hex(prev_block_hash)))
                  break
  
          # Truncate the list if there are too many headers
          headers_list = headers_list[:-maxheaders - 1:-1]
          response = msg_headers(headers_list)
  
          if response is not None:
              self.send_message(response)
  
      def on_reject(self, message):
          """Store reject reason and code for testing."""
          self.reject_code_received = message.code
          self.reject_reason_received = message.reason
  
      def send_blocks_and_test(self, blocks, rpc, success=True, request_block=True, reject_code=None, reject_reason=None, timeout=60):
          """Send blocks to test node and test whether the tip advances.
  
           - add all blocks to our block_store
           - send a headers message for the final block
           - the on_getheaders handler will ensure that any getheaders are responded to
           - if request_block is True: wait for getdata for each of the blocks. The on_getdata handler will
             ensure that any getdata messages are responded to
           - if success is True: assert that the node's tip advances to the most recent block
           - if success is False: assert that the node's tip doesn't advance
           - if reject_code and reject_reason are set: assert that the correct reject message is received"""
  
          with mininode_lock:
              self.reject_code_received = None
              self.reject_reason_received = None
  
              for block in blocks:
                  self.block_store[block.sha256] = block
                  self.last_block_hash = block.sha256
  
          self.send_message(msg_headers([CBlockHeader(blocks[-1])]))
  
          if request_block:
              wait_until(lambda: blocks[-1].sha256 in self.getdata_requests, timeout=timeout, lock=mininode_lock)
  
          if success:
              wait_until(lambda: rpc.getbestblockhash() == blocks[-1].hash, timeout=timeout)
          else:
              assert rpc.getbestblockhash() != blocks[-1].hash
  
          if reject_code is not None:
              wait_until(lambda: self.reject_code_received == reject_code, lock=mininode_lock)
          if reject_reason is not None:
              wait_until(lambda: self.reject_reason_received == reject_reason, lock=mininode_lock)
  
      def send_txs_and_test(self, txs, rpc, success=True, expect_disconnect=False, reject_code=None, reject_reason=None):
          """Send txs to test node and test whether they're accepted to the mempool.
  
           - add all txs to our tx_store
           - send tx messages for all txs
           - if success is True/False: assert that the txs are/are not accepted to the mempool
           - if expect_disconnect is True: Skip the sync with ping
           - if reject_code and reject_reason are set: assert that the correct reject message is received."""
  
          with mininode_lock:
              self.reject_code_received = None
              self.reject_reason_received = None
  
              for tx in txs:
                  self.tx_store[tx.sha256] = tx
  
          for tx in txs:
              self.send_message(msg_tx(tx))
  
          if expect_disconnect:
              self.wait_for_disconnect()
          else:
              self.sync_with_ping()
  
          raw_mempool = rpc.getrawmempool()
          if success:
              # Check that all txs are now in the mempool
              for tx in txs:
                  assert tx.hash in raw_mempool, "{} not found in mempool".format(tx.hash)
          else:
              # Check that none of the txs are now in the mempool
              for tx in txs:
                  assert tx.hash not in raw_mempool, "{} tx found in mempool".format(tx.hash)
  
          if reject_code is not None:
              wait_until(lambda: self.reject_code_received == reject_code, lock=mininode_lock)
          if reject_reason is not None:
              wait_until(lambda: self.reject_reason_received == reject_reason, lock=mininode_lock)
  