text: #!/usr/bin/env python3
  # Copyright (c) 2015-2016 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test behavior of -maxuploadtarget.
  
  * Verify that getdata requests for old blocks (>1week) are dropped
  if uploadtarget has been reached.
  * Verify that getdata requests for recent blocks are respected even
  if uploadtarget has been reached.
  * Verify that the upload counters are reset after 24 hours.
  """
  
  from collections import defaultdict
  import time
  
  from test_framework.cdefs import LEGACY_MAX_BLOCK_SIZE
  from test_framework.blocktools import mine_big_block
  from test_framework.messages import CInv, msg_getdata
  from test_framework.mininode import P2PInterface
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import assert_equal
  
  
  class TestP2PConn(P2PInterface):
      def __init__(self):
          super().__init__()
          self.block_receive_map = defaultdict(int)
  
      def on_inv(self, message):
          pass
  
      def on_block(self, message):
          message.block.calc_sha256()
          self.block_receive_map[message.block.sha256] += 1
  
  
  class MaxUploadTest(BitcoinTestFramework):
      def set_test_params(self):
          self.setup_clean_chain = True
          self.num_nodes = 1
          # Start a node with maxuploadtarget of 200 MB (/24h)
          self.extra_args = [["-maxuploadtarget=200", "-acceptnonstdtxn=1"]]
  
          # Cache for utxos, as the listunspent may take a long time later in the
          # test
          self.utxo_cache = []
  
      def skip_test_if_missing_module(self):
          self.skip_if_no_wallet()
  
      def run_test(self):
          # Before we connect anything, we first set the time on the node
          # to be in the past, otherwise things break because the CNode
          # time counters can't be reset backward after initialization
          old_time = int(time.time() - 2 * 60 * 60 * 24 * 7)
          self.nodes[0].setmocktime(old_time)
  
          # Generate some old blocks
          self.nodes[0].generate(130)
  
          # p2p_conns[0] will only request old blocks
          # p2p_conns[1] will only request new blocks
          # p2p_conns[2] will test resetting the counters
          p2p_conns = []
  
          for _ in range(3):
              p2p_conns.append(self.nodes[0].add_p2p_connection(TestP2PConn()))
  
          # Now mine a big block
          mine_big_block(self.nodes[0], self.utxo_cache)
  
          # Store the hash; we'll request this later
          big_old_block = self.nodes[0].getbestblockhash()
          old_block_size = self.nodes[0].getblock(big_old_block, True)['size']
          big_old_block = int(big_old_block, 16)
  
          # Advance to two days ago
          self.nodes[0].setmocktime(int(time.time()) - 2 * 60 * 60 * 24)
  
          # Mine one more block, so that the prior block looks old
          mine_big_block(self.nodes[0], self.utxo_cache)
  
          # We'll be requesting this new block too
          big_new_block = self.nodes[0].getbestblockhash()
          big_new_block = int(big_new_block, 16)
  
          # p2p_conns[0] will test what happens if we just keep requesting the
          # the same big old block too many times (expect: disconnect)
  
          getdata_request = msg_getdata()
          getdata_request.inv.append(CInv(2, big_old_block))
  
          max_bytes_per_day = 200 * 1024 * 1024
          daily_buffer = 144 * LEGACY_MAX_BLOCK_SIZE
          max_bytes_available = max_bytes_per_day - daily_buffer
          success_count = max_bytes_available // old_block_size
  
          # 144MB will be reserved for relaying new blocks, so expect this to
          # succeed for ~70 tries.
          for i in range(success_count):
              p2p_conns[0].send_and_ping(getdata_request)
              assert_equal(p2p_conns[0].block_receive_map[big_old_block], i + 1)
  
          assert_equal(len(self.nodes[0].getpeerinfo()), 3)
          # At most a couple more tries should succeed (depending on how long
          # the test has been running so far).
          for i in range(3):
              p2p_conns[0].send_message(getdata_request)
          p2p_conns[0].wait_for_disconnect()
          assert_equal(len(self.nodes[0].getpeerinfo()), 2)
          self.log.info(
              "Peer 0 disconnected after downloading old block too many times")
  
          # Requesting the current block on p2p_conns[1] should succeed indefinitely,
          # even when over the max upload target.
          # We'll try 200 times
          getdata_request.inv = [CInv(2, big_new_block)]
          for i in range(200):
              p2p_conns[1].send_and_ping(getdata_request)
              assert_equal(p2p_conns[1].block_receive_map[big_new_block], i + 1)
  
          self.log.info("Peer 1 able to repeatedly download new block")
  
          # But if p2p_conns[1] tries for an old block, it gets disconnected
          # too.
          getdata_request.inv = [CInv(2, big_old_block)]
          p2p_conns[1].send_message(getdata_request)
          p2p_conns[1].wait_for_disconnect()
          assert_equal(len(self.nodes[0].getpeerinfo()), 1)
  
          self.log.info("Peer 1 disconnected after trying to download old block")
  
          self.log.info("Advancing system time on node to clear counters...")
  
          # If we advance the time by 24 hours, then the counters should reset,
          # and p2p_conns[2] should be able to retrieve the old block.
          self.nodes[0].setmocktime(int(time.time()))
          p2p_conns[2].sync_with_ping()
          p2p_conns[2].send_and_ping(getdata_request)
          assert_equal(p2p_conns[2].block_receive_map[big_old_block], 1)
  
          self.log.info("Peer 2 able to download old block")
  
          self.nodes[0].disconnect_p2ps()
  
          # stop and start node 0 with 1MB maxuploadtarget, whitelist 127.0.0.1
          self.log.info("Restarting nodes with -whitelist=127.0.0.1")
          self.stop_node(0)
          self.start_node(0, ["-whitelist=127.0.0.1",
                              "-maxuploadtarget=1", "-blockmaxsize=999000"])
  
          # Reconnect to self.nodes[0]
          self.nodes[0].add_p2p_connection(TestP2PConn())
  
          # retrieve 20 blocks which should be enough to break the 1MB limit
          getdata_request.inv = [CInv(2, big_new_block)]
          for i in range(20):
              self.nodes[0].p2p.send_and_ping(getdata_request)
              assert_equal(
                  self.nodes[0].p2p.block_receive_map[big_new_block], i + 1)
  
          getdata_request.inv = [CInv(2, big_old_block)]
          self.nodes[0].p2p.send_and_ping(getdata_request)
          # node is still connected because of the whitelist
          assert_equal(len(self.nodes[0].getpeerinfo()), 1)
  
          self.log.info(
              "Peer still connected after trying to download old block (whitelisted)")
  
  
  if __name__ == '__main__':
      MaxUploadTest().main()
  