1  #!/usr/bin/env python3
  2  # Copyright (c) 2022-present 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  """
  6  Test stalling logic during IBD
  7  """
  8  
  9  import time
 10  
 11  from test_framework.blocktools import (
 12          create_block,
 13  )
 14  from test_framework.messages import (
 15          MSG_BLOCK,
 16          MSG_TYPE_MASK,
 17  )
 18  from test_framework.p2p import (
 19          CBlockHeader,
 20          msg_block,
 21          msg_headers,
 22          P2PDataStore,
 23  )
 24  from test_framework.test_framework import BitcoinTestFramework
 25  from test_framework.util import (
 26          assert_equal,
 27  )
 28  
 29  
 30  class P2PStaller(P2PDataStore):
 31      def __init__(self, stall_blocks):
 32          self.stall_blocks = stall_blocks
 33          super().__init__()
 34  
 35      def on_getdata(self, message):
 36          for inv in message.inv:
 37              self.getdata_requests.append(inv.hash)
 38              if (inv.type & MSG_TYPE_MASK) == MSG_BLOCK:
 39                  if (inv.hash not in self.stall_blocks):
 40                      self.send_without_ping(msg_block(self.block_store[inv.hash]))
 41  
 42      def on_getheaders(self, message):
 43          pass
 44  
 45  
 46  class P2PIBDStallingTest(BitcoinTestFramework):
 47      def set_test_params(self):
 48          self.setup_clean_chain = True
 49          self.num_nodes = 1
 50  
 51      def run_test(self):
 52          NUM_BLOCKS = 1025
 53          NUM_PEERS = 5
 54          node = self.nodes[0]
 55          tip = int(node.getbestblockhash(), 16)
 56          blocks = []
 57          height = 1
 58          block_time = node.getblock(node.getbestblockhash())['time'] + 1
 59          self.log.info("Prepare blocks without sending them to the node")
 60          block_dict = {}
 61          for _ in range(NUM_BLOCKS):
 62              blocks.append(create_block(tip, height=height, ntime=block_time))
 63              blocks[-1].solve()
 64              tip = blocks[-1].hash_int
 65              block_time += 1
 66              height += 1
 67              block_dict[blocks[-1].hash_int] = blocks[-1]
 68          stall_index = 0
 69          second_stall_index = 500
 70          stall_blocks = [blocks[stall_index].hash_int, blocks[second_stall_index].hash_int]
 71  
 72          headers_message = msg_headers()
 73          headers_message.headers = [CBlockHeader(b) for b in blocks[:NUM_BLOCKS-1]]
 74          peers = []
 75  
 76          self.log.info("Check that a staller does not get disconnected if the 1024 block lookahead buffer is filled")
 77          self.mocktime = int(time.time()) + 1
 78          node.setmocktime(self.mocktime)
 79          for id in range(NUM_PEERS):
 80              peers.append(node.add_outbound_p2p_connection(P2PStaller(stall_blocks), p2p_idx=id, connection_type="outbound-full-relay"))
 81              peers[-1].block_store = block_dict
 82              peers[-1].send_and_ping(headers_message)
 83  
 84          # Wait until all blocks are received (except for the stall blocks), so that no other blocks are in flight.
 85          self.wait_until(lambda: sum(len(peer['inflight']) for peer in node.getpeerinfo()) == len(stall_blocks))
 86  
 87          self.all_sync_send_with_ping(peers)
 88          # If there was a peer marked for stalling, it would get disconnected
 89          self.mocktime += 3
 90          node.setmocktime(self.mocktime)
 91          self.all_sync_send_with_ping(peers)
 92          assert_equal(node.num_test_p2p_connections(), NUM_PEERS)
 93  
 94          self.log.info("Check that increasing the window beyond 1024 blocks triggers stalling logic")
 95          headers_message.headers = [CBlockHeader(b) for b in blocks]
 96          with node.assert_debug_log(expected_msgs=['Stall started']):
 97              for p in peers:
 98                  p.send_without_ping(headers_message)
 99              self.all_sync_send_with_ping(peers)
100  
101          self.log.info("Check that the stalling peer is disconnected after 2 seconds")
102          self.mocktime += 3
103          node.setmocktime(self.mocktime)
104          peers[0].wait_for_disconnect()
105          assert_equal(node.num_test_p2p_connections(), NUM_PEERS - 1)
106          self.wait_until(lambda: self.is_block_requested(peers, stall_blocks[0]))
107          # Make sure that SendMessages() is invoked, which assigns the missing block
108          # to another peer and starts the stalling logic for them
109          self.all_sync_send_with_ping(peers)
110  
111          self.log.info("Check that the stalling timeout gets doubled to 4 seconds for the next staller")
112          # No disconnect after just 3 seconds
113          self.mocktime += 3
114          node.setmocktime(self.mocktime)
115          self.all_sync_send_with_ping(peers)
116          assert_equal(node.num_test_p2p_connections(), NUM_PEERS - 1)
117  
118          self.mocktime += 2
119          node.setmocktime(self.mocktime)
120          self.wait_until(lambda: sum(x.is_connected for x in node.p2ps) == NUM_PEERS - 2)
121          self.wait_until(lambda: self.is_block_requested(peers, stall_blocks[0]))
122          self.all_sync_send_with_ping(peers)
123  
124          self.log.info("Check that the stalling timeout gets doubled to 8 seconds for the next staller")
125          # No disconnect after just 7 seconds
126          self.mocktime += 7
127          node.setmocktime(self.mocktime)
128          self.all_sync_send_with_ping(peers)
129          assert_equal(node.num_test_p2p_connections(), NUM_PEERS - 2)
130  
131          self.mocktime += 2
132          node.setmocktime(self.mocktime)
133          self.wait_until(lambda: sum(x.is_connected for x in node.p2ps) == NUM_PEERS - 3)
134          self.wait_until(lambda: self.is_block_requested(peers, stall_blocks[0]))
135          self.all_sync_send_with_ping(peers)
136  
137          self.log.info("Provide the first withheld block and check that stalling timeout gets reduced back to 2 seconds")
138          with node.assert_debug_log(expected_msgs=['Decreased stalling timeout to 2 seconds'], unexpected_msgs=['Stall started']):
139              for p in peers:
140                  if p.is_connected and (stall_blocks[0] in p.getdata_requests):
141                      p.send_without_ping(msg_block(block_dict[stall_blocks[0]]))
142              self.all_sync_send_with_ping(peers)
143  
144          self.log.info("Check that all outstanding blocks up to the second stall block get connected")
145          self.wait_until(lambda: node.getblockcount() == second_stall_index)
146  
147  
148      def all_sync_send_with_ping(self, peers):
149          for p in peers:
150              if p.is_connected:
151                  p.sync_with_ping()
152  
153      def is_block_requested(self, peers, hash):
154          for p in peers:
155              if p.is_connected and (hash in p.getdata_requests):
156                  return True
157          return False
158  
159  
160  if __name__ == '__main__':
161      P2PIBDStallingTest(__file__).main()