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