#!/usr/bin/env python3 # Copyright (c) 2015-2022 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 processing of unrequested blocks. Setup: two nodes, node0 + node1, not connected to each other. Node1 will have nMinimumChainWork set to 0x10, so it won't process low-work unrequested blocks. We have one P2PInterface connection to node0 called test_node, and one to node1 called min_work_node. The test: 1. Generate one block on each node, to leave IBD. 2. Mine a new block on each tip, and deliver to each node from node's peer. The tip should advance for node0, but node1 should skip processing due to nMinimumChainWork. Node1 is unused in tests 3-7: 3. Mine a block that forks from the genesis block, and deliver to test_node. Node0 should not process this block (just accept the header), because it is unrequested and doesn't have more or equal work to the tip. 4a,b. Send another two blocks that build on the forking block. Node0 should process the second block but be stuck on the shorter chain, because it's missing an intermediate block. 4c.Send 288 more blocks on the longer chain (the number of blocks ahead we currently store). Node0 should process all but the last block (too far ahead in height). 5. Send a duplicate of the block in #3 to Node0. Node0 should not process the block because it is unrequested, and stay on the shorter chain. 6. Send Node0 an inv for the height 3 block produced in #4 above. Node0 should figure out that Node0 has the missing height 2 block and send a getdata. 7. Send Node0 the missing block again. Node0 should process and the tip should advance. 8. Create a fork which is invalid at a height longer than the current chain (ie to which the node will try to reorg) but which has headers built on top of the invalid block. Check that we get disconnected if we send more headers on the chain the node now knows to be invalid. 9. Test Node1 is able to sync when connected to node0 (which should have sufficient work on its chain). """ import time from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script from test_framework.messages import CBlockHeader, CInv, MSG_BLOCK, msg_block, msg_headers, msg_inv from test_framework.p2p import p2p_lock, P2PInterface from test_framework.test_framework import BitcoinTestFramework from test_framework.util import ( assert_equal, assert_raises_rpc_error, ) class AcceptBlockTest(BitcoinTestFramework): def set_test_params(self): self.setup_clean_chain = True self.num_nodes = 2 self.extra_args = [[], ["-minimumchainwork=0x10"]] def setup_network(self): self.setup_nodes() def check_hash_in_chaintips(self, node, blockhash): tips = node.getchaintips() for x in tips: if x["hash"] == blockhash: return True return False def run_test(self): test_node = self.nodes[0].add_p2p_connection(P2PInterface()) min_work_node = self.nodes[1].add_p2p_connection(P2PInterface()) # 1. Have nodes mine a block (leave IBD) [self.generate(n, 1, sync_fun=self.no_op) for n in self.nodes] tips = [int("0x" + n.getbestblockhash(), 0) for n in self.nodes] # 2. Send one block that builds on each tip. # This should be accepted by node0 blocks_h2 = [] # the height 2 blocks on each node's chain block_time = int(time.time()) + 1 for i in range(2): blocks_h2.append(create_block(tips[i], create_coinbase(2), block_time)) blocks_h2[i].solve() block_time += 1 test_node.send_and_ping(msg_block(blocks_h2[0])) with self.nodes[1].assert_debug_log(expected_msgs=[f"AcceptBlockHeader: not adding new block header {blocks_h2[1].hash}, missing anti-dos proof-of-work validation"]): min_work_node.send_and_ping(msg_block(blocks_h2[1])) assert_equal(self.nodes[0].getblockcount(), 2) assert_equal(self.nodes[1].getblockcount(), 1) # Ensure that the header of the second block was also not accepted by node1 assert_equal(self.check_hash_in_chaintips(self.nodes[1], blocks_h2[1].hash), False) self.log.info("First height 2 block accepted by node0; correctly rejected by node1") # 3. Send another block that builds on genesis. block_h1f = create_block(int("0x" + self.nodes[0].getblockhash(0), 0), create_coinbase(1), block_time) block_time += 1 block_h1f.solve() test_node.send_and_ping(msg_block(block_h1f)) tip_entry_found = False for x in self.nodes[0].getchaintips(): if x['hash'] == block_h1f.hash: assert_equal(x['status'], "headers-only") tip_entry_found = True assert tip_entry_found assert_raises_rpc_error(-1, "Block not available (not fully downloaded)", self.nodes[0].getblock, block_h1f.hash) # 4. Send another two block that build on the fork. block_h2f = create_block(block_h1f.sha256, create_coinbase(2), block_time) block_time += 1 block_h2f.solve() test_node.send_and_ping(msg_block(block_h2f)) # Since the earlier block was not processed by node, the new block # can't be fully validated. tip_entry_found = False for x in self.nodes[0].getchaintips(): if x['hash'] == block_h2f.hash: assert_equal(x['status'], "headers-only") tip_entry_found = True assert tip_entry_found # But this block should be accepted by node since it has equal work. self.nodes[0].getblock(block_h2f.hash) self.log.info("Second height 2 block accepted, but not reorg'ed to") # 4b. Now send another block that builds on the forking chain. block_h3 = create_block(block_h2f.sha256, create_coinbase(3), block_h2f.nTime+1) block_h3.solve() test_node.send_and_ping(msg_block(block_h3)) # Since the earlier block was not processed by node, the new block # can't be fully validated. tip_entry_found = False for x in self.nodes[0].getchaintips(): if x['hash'] == block_h3.hash: assert_equal(x['status'], "headers-only") tip_entry_found = True assert tip_entry_found self.nodes[0].getblock(block_h3.hash) # But this block should be accepted by node since it has more work. self.nodes[0].getblock(block_h3.hash) self.log.info("Unrequested more-work block accepted") # 4c. Now mine 288 more blocks and deliver; all should be processed but # the last (height-too-high) on node (as long as it is not missing any headers) tip = block_h3 all_blocks = [] for i in range(288): next_block = create_block(tip.sha256, create_coinbase(i + 4), tip.nTime+1) next_block.solve() all_blocks.append(next_block) tip = next_block # Now send the block at height 5 and check that it wasn't accepted (missing header) test_node.send_message(msg_block(all_blocks[1])) test_node.wait_for_disconnect() assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getblock, all_blocks[1].hash) assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getblockheader, all_blocks[1].hash) test_node = self.nodes[0].add_p2p_connection(P2PInterface()) # The block at height 5 should be accepted if we provide the missing header, though headers_message = msg_headers() headers_message.headers.append(CBlockHeader(all_blocks[0])) test_node.send_message(headers_message) test_node.send_and_ping(msg_block(all_blocks[1])) self.nodes[0].getblock(all_blocks[1].hash) # Now send the blocks in all_blocks for i in range(288): test_node.send_message(msg_block(all_blocks[i])) test_node.sync_with_ping() # Blocks 1-287 should be accepted, block 288 should be ignored because it's too far ahead for x in all_blocks[:-1]: self.nodes[0].getblock(x.hash) assert_raises_rpc_error(-1, "Block not available (not fully downloaded)", self.nodes[0].getblock, all_blocks[-1].hash) # 5. Test handling of unrequested block on the node that didn't process # Should still not be processed (even though it has a child that has more # work). # The node should have requested the blocks at some point, so # disconnect/reconnect first self.nodes[0].disconnect_p2ps() self.nodes[1].disconnect_p2ps() test_node = self.nodes[0].add_p2p_connection(P2PInterface()) test_node.send_and_ping(msg_block(block_h1f)) assert_equal(self.nodes[0].getblockcount(), 2) self.log.info("Unrequested block that would complete more-work chain was ignored") # 6. Try to get node to request the missing block. # Poke the node with an inv for block at height 3 and see if that # triggers a getdata on block 2 (it should if block 2 is missing). with p2p_lock: # Clear state so we can check the getdata request test_node.last_message.pop("getdata", None) test_node.send_message(msg_inv([CInv(MSG_BLOCK, block_h3.sha256)])) test_node.sync_with_ping() with p2p_lock: getdata = test_node.last_message["getdata"] # Check that the getdata includes the right block assert_equal(getdata.inv[0].hash, block_h1f.sha256) self.log.info("Inv at tip triggered getdata for unprocessed block") # 7. Send the missing block for the third time (now it is requested) test_node.send_and_ping(msg_block(block_h1f)) assert_equal(self.nodes[0].getblockcount(), 290) self.nodes[0].getblock(all_blocks[286].hash) assert_equal(self.nodes[0].getbestblockhash(), all_blocks[286].hash) assert_raises_rpc_error(-1, "Block not available (not fully downloaded)", self.nodes[0].getblock, all_blocks[287].hash) self.log.info("Successfully reorged to longer chain") # 8. Create a chain which is invalid at a height longer than the # current chain, but which has more blocks on top of that block_289f = create_block(all_blocks[284].sha256, create_coinbase(289), all_blocks[284].nTime+1) block_289f.solve() block_290f = create_block(block_289f.sha256, create_coinbase(290), block_289f.nTime+1) block_290f.solve() # block_291 spends a coinbase below maturity! tx_to_add = create_tx_with_script(block_290f.vtx[0], 0, script_sig=b"42", amount=1) block_291 = create_block(block_290f.sha256, create_coinbase(291), block_290f.nTime+1, txlist=[tx_to_add]) block_291.solve() block_292 = create_block(block_291.sha256, create_coinbase(292), block_291.nTime+1) block_292.solve() # Now send all the headers on the chain and enough blocks to trigger reorg headers_message = msg_headers() headers_message.headers.append(CBlockHeader(block_289f)) headers_message.headers.append(CBlockHeader(block_290f)) headers_message.headers.append(CBlockHeader(block_291)) headers_message.headers.append(CBlockHeader(block_292)) test_node.send_and_ping(headers_message) tip_entry_found = False for x in self.nodes[0].getchaintips(): if x['hash'] == block_292.hash: assert_equal(x['status'], "headers-only") tip_entry_found = True assert tip_entry_found assert_raises_rpc_error(-1, "Block not available (not fully downloaded)", self.nodes[0].getblock, block_292.hash) test_node.send_message(msg_block(block_289f)) test_node.send_and_ping(msg_block(block_290f)) self.nodes[0].getblock(block_289f.hash) self.nodes[0].getblock(block_290f.hash) test_node.send_message(msg_block(block_291)) # At this point we've sent an obviously-bogus block, wait for full processing # and assume disconnection test_node.wait_for_disconnect() self.nodes[0].disconnect_p2ps() test_node = self.nodes[0].add_p2p_connection(P2PInterface()) # We should have failed reorg and switched back to 290 (but have block 291) assert_equal(self.nodes[0].getblockcount(), 290) assert_equal(self.nodes[0].getbestblockhash(), all_blocks[286].hash) assert_equal(self.nodes[0].getblock(block_291.hash)["confirmations"], -1) # Now send a new header on the invalid chain, indicating we're forked off, and expect to get disconnected block_293 = create_block(block_292.sha256, create_coinbase(293), block_292.nTime+1) block_293.solve() headers_message = msg_headers() headers_message.headers.append(CBlockHeader(block_293)) test_node.send_message(headers_message) test_node.wait_for_disconnect() # 9. Connect node1 to node0 and ensure it is able to sync self.connect_nodes(0, 1) self.sync_blocks([self.nodes[0], self.nodes[1]]) self.log.info("Successfully synced nodes 1 and 0") if __name__ == '__main__': AcceptBlockTest(__file__).main()