1  // Copyright (c) 2024-present The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or https://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <chainparams.h>
 6  #include <node/miner.h>
 7  #include <net_processing.h>
 8  #include <pow.h>
 9  #include <test/util/setup_common.h>
10  #include <validation.h>
11  
12  #include <boost/test/unit_test.hpp>
13  
14  BOOST_FIXTURE_TEST_SUITE(peerman_tests, RegTestingSetup)
15  
16  /** Window, in blocks, for connecting to NODE_NETWORK_LIMITED peers */
17  static constexpr int64_t NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS = 144;
18  
19  static void mineBlock(const node::NodeContext& node, std::chrono::seconds block_time)
20  {
21      auto curr_time = GetTime<std::chrono::seconds>();
22      SetMockTime(block_time); // update time so the block is created with it
23      CBlock block = node::BlockAssembler{node.chainman->ActiveChainstate(), nullptr}.CreateNewBlock(CScript() << OP_TRUE)->block;
24      while (!CheckProofOfWork(block.GetHash(), block.nBits, node.chainman->GetConsensus())) ++block.nNonce;
25      block.fChecked = true; // little speedup
26      SetMockTime(curr_time); // process block at current time
27      Assert(node.chainman->ProcessNewBlock(std::make_shared<const CBlock>(block), /*force_processing=*/true, /*min_pow_checked=*/true, nullptr));
28      node.validation_signals->SyncWithValidationInterfaceQueue(); // drain events queue
29  }
30  
31  // Verifying when network-limited peer connections are desirable based on the node's proximity to the tip
32  BOOST_AUTO_TEST_CASE(connections_desirable_service_flags)
33  {
34      std::unique_ptr<PeerManager> peerman = PeerManager::make(*m_node.connman, *m_node.addrman, nullptr, *m_node.chainman, *m_node.mempool, {});
35      auto consensus = m_node.chainman->GetParams().GetConsensus();
36  
37      // Check we start connecting to full nodes
38      ServiceFlags peer_flags{NODE_WITNESS | NODE_NETWORK_LIMITED};
39      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK | NODE_WITNESS));
40  
41      // Make peerman aware of the initial best block and verify we accept limited peers when we start close to the tip time.
42      auto tip = WITH_LOCK(::cs_main, return m_node.chainman->ActiveChain().Tip());
43      uint64_t tip_block_time = tip->GetBlockTime();
44      int tip_block_height = tip->nHeight;
45      peerman->SetBestBlock(tip_block_height, std::chrono::seconds{tip_block_time});
46  
47      SetMockTime(tip_block_time + 1); // Set node time to tip time
48      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS));
49  
50      // Check we don't disallow limited peers connections when we are behind but still recoverable (below the connection safety window)
51      SetMockTime(GetTime<std::chrono::seconds>() + std::chrono::seconds{consensus.nPowTargetSpacing * (NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS - 1)});
52      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS));
53  
54      // Check we disallow limited peers connections when we are further than the limited peers safety window
55      SetMockTime(GetTime<std::chrono::seconds>() + std::chrono::seconds{consensus.nPowTargetSpacing * 2});
56      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK | NODE_WITNESS));
57  
58      // By now, we tested that the connections desirable services flags change based on the node's time proximity to the tip.
59      // Now, perform the same tests for when the node receives a block.
60      m_node.validation_signals->RegisterValidationInterface(peerman.get());
61  
62      // First, verify a block in the past doesn't enable limited peers connections
63      // At this point, our time is (NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS + 1) * 10 minutes ahead the tip's time.
64      mineBlock(m_node, /*block_time=*/std::chrono::seconds{tip_block_time + 1});
65      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK | NODE_WITNESS));
66  
67      // Verify a block close to the tip enables limited peers connections
68      mineBlock(m_node, /*block_time=*/GetTime<std::chrono::seconds>());
69      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS));
70  
71      // Lastly, verify the stale tip checks can disallow limited peers connections after not receiving blocks for a prolonged period.
72      SetMockTime(GetTime<std::chrono::seconds>() + std::chrono::seconds{consensus.nPowTargetSpacing * NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS + 1});
73      BOOST_CHECK(peerman->GetDesirableServiceFlags(peer_flags) == ServiceFlags(NODE_NETWORK | NODE_WITNESS));
74  }
75  
76  BOOST_AUTO_TEST_SUITE_END()