validation_block_tests.cpp raw

   1  // Copyright (c) 2018-present The Bitcoin Core developers
   2  // Distributed under the MIT software license, see the accompanying
   3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4  
   5  #include <chain.h>
   6  #include <chainparams.h>
   7  #include <consensus/consensus.h>
   8  #include <consensus/merkle.h>
   9  #include <consensus/validation.h>
  10  #include <interfaces/mining.h>
  11  #include <node/blockstorage.h>
  12  #include <pow.h>
  13  #include <primitives/block.h>
  14  #include <primitives/transaction.h>
  15  #include <random.h>
  16  #include <script/script.h>
  17  #include <sync.h>
  18  #include <test/util/common.h>
  19  #include <test/util/script.h>
  20  #include <test/util/setup_common.h>
  21  #include <txmempool.h>
  22  #include <uint256.h>
  23  #include <util/check.h>
  24  #include <validation.h>
  25  #include <validationinterface.h>
  26  
  27  #include <boost/test/unit_test.hpp>
  28  
  29  #include <cstddef>
  30  #include <cstdint>
  31  #include <memory>
  32  #include <span>
  33  #include <thread>
  34  #include <utility>
  35  #include <vector>
  36  
  37  using kernel::ChainstateRole;
  38  
  39  namespace validation_block_tests {
  40  struct MinerTestingSetup : public RegTestingSetup {
  41      std::shared_ptr<CBlock> Block(const uint256& prev_hash);
  42      std::shared_ptr<const CBlock> GoodBlock(const uint256& prev_hash);
  43      std::shared_ptr<const CBlock> BadBlock(const uint256& prev_hash);
  44      std::shared_ptr<CBlock> FinalizeBlock(std::shared_ptr<CBlock> pblock);
  45      void BuildChain(const uint256& root, int height, unsigned int invalid_rate, unsigned int branch_rate, unsigned int max_size, std::vector<std::shared_ptr<const CBlock>>& blocks);
  46  };
  47  } // namespace validation_block_tests
  48  
  49  BOOST_FIXTURE_TEST_SUITE(validation_block_tests, MinerTestingSetup)
  50  
  51  struct TestSubscriber final : public CValidationInterface {
  52      uint256 m_expected_tip;
  53  
  54      explicit TestSubscriber(uint256 tip) : m_expected_tip(tip) {}
  55  
  56      void UpdatedBlockTip(const CBlockIndex* pindexNew, const CBlockIndex* pindexFork, bool fInitialDownload) override
  57      {
  58          BOOST_CHECK_EQUAL(m_expected_tip, pindexNew->GetBlockHash());
  59      }
  60  
  61      void BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
  62      {
  63          BOOST_CHECK_EQUAL(m_expected_tip, block->hashPrevBlock);
  64          BOOST_CHECK_EQUAL(m_expected_tip, pindex->pprev->GetBlockHash());
  65  
  66          m_expected_tip = block->GetHash();
  67      }
  68  
  69      void BlockDisconnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
  70      {
  71          BOOST_CHECK_EQUAL(m_expected_tip, block->GetHash());
  72          BOOST_CHECK_EQUAL(m_expected_tip, pindex->GetBlockHash());
  73  
  74          m_expected_tip = block->hashPrevBlock;
  75      }
  76  };
  77  
  78  std::shared_ptr<CBlock> MinerTestingSetup::Block(const uint256& prev_hash)
  79  {
  80      static int i = 0;
  81      static uint64_t time = Params().GenesisBlock().nTime;
  82  
  83      auto mining{interfaces::MakeMining(m_node)};
  84      auto block_template{mining->createNewBlock({
  85          .coinbase_output_script = CScript{} << i++ << OP_TRUE,
  86      }, /*cooldown=*/false)};
  87      BOOST_REQUIRE(block_template);
  88      auto pblock = std::make_shared<CBlock>(block_template->getBlock());
  89      pblock->hashPrevBlock = prev_hash;
  90      pblock->nTime = ++time;
  91  
  92      // Make the coinbase transaction with two outputs:
  93      // One zero-value one that has a unique pubkey to make sure that blocks at the same height can have a different hash
  94      // Another one that has the coinbase reward in a P2WSH with OP_TRUE as witness program to make it easy to spend
  95      CMutableTransaction txCoinbase(*pblock->vtx[0]);
  96      txCoinbase.vout.resize(2);
  97      txCoinbase.vout[1].scriptPubKey = P2WSH_OP_TRUE;
  98      txCoinbase.vout[1].nValue = txCoinbase.vout[0].nValue;
  99      txCoinbase.vout[0].nValue = 0;
 100      txCoinbase.vin[0].scriptWitness.SetNull();
 101      // Always pad with OP_0 as dummy extraNonce (also avoids bad-cb-length error for block <=16)
 102      const int prev_height{WITH_LOCK(::cs_main, return m_node.chainman->m_blockman.LookupBlockIndex(prev_hash)->nHeight)};
 103      txCoinbase.vin[0].scriptSig = CScript{} << prev_height + 1 << OP_0;
 104      txCoinbase.nLockTime = static_cast<uint32_t>(prev_height);
 105      pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
 106  
 107      return pblock;
 108  }
 109  
 110  std::shared_ptr<CBlock> MinerTestingSetup::FinalizeBlock(std::shared_ptr<CBlock> pblock)
 111  {
 112      const CBlockIndex* prev_block{WITH_LOCK(::cs_main, return m_node.chainman->m_blockman.LookupBlockIndex(pblock->hashPrevBlock))};
 113      m_node.chainman->GenerateCoinbaseCommitment(*pblock, prev_block);
 114  
 115      pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
 116  
 117      while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
 118          ++(pblock->nNonce);
 119      }
 120  
 121      // submit block header, so that miner can get the block height from the
 122      // global state and the node has the topology of the chain
 123      BlockValidationState ignored;
 124      BOOST_CHECK(Assert(m_node.chainman)->ProcessNewBlockHeaders({{*pblock}}, true, ignored));
 125  
 126      return pblock;
 127  }
 128  
 129  // construct a valid block
 130  std::shared_ptr<const CBlock> MinerTestingSetup::GoodBlock(const uint256& prev_hash)
 131  {
 132      return FinalizeBlock(Block(prev_hash));
 133  }
 134  
 135  // construct an invalid block (but with a valid header)
 136  std::shared_ptr<const CBlock> MinerTestingSetup::BadBlock(const uint256& prev_hash)
 137  {
 138      auto pblock = Block(prev_hash);
 139  
 140      CMutableTransaction coinbase_spend;
 141      coinbase_spend.vin.emplace_back(COutPoint(pblock->vtx[0]->GetHash(), 0), CScript(), 0);
 142      coinbase_spend.vout.push_back(pblock->vtx[0]->vout[0]);
 143  
 144      CTransactionRef tx = MakeTransactionRef(coinbase_spend);
 145      pblock->vtx.push_back(tx);
 146  
 147      auto ret = FinalizeBlock(pblock);
 148      return ret;
 149  }
 150  
 151  // NOLINTNEXTLINE(misc-no-recursion)
 152  void MinerTestingSetup::BuildChain(const uint256& root, int height, const unsigned int invalid_rate, const unsigned int branch_rate, const unsigned int max_size, std::vector<std::shared_ptr<const CBlock>>& blocks)
 153  {
 154      if (height <= 0 || blocks.size() >= max_size) return;
 155  
 156      bool gen_invalid = m_rng.randrange(100U) < invalid_rate;
 157      bool gen_fork = m_rng.randrange(100U) < branch_rate;
 158  
 159      const std::shared_ptr<const CBlock> pblock = gen_invalid ? BadBlock(root) : GoodBlock(root);
 160      blocks.push_back(pblock);
 161      if (!gen_invalid) {
 162          BuildChain(pblock->GetHash(), height - 1, invalid_rate, branch_rate, max_size, blocks);
 163      }
 164  
 165      if (gen_fork) {
 166          blocks.push_back(GoodBlock(root));
 167          BuildChain(blocks.back()->GetHash(), height - 1, invalid_rate, branch_rate, max_size, blocks);
 168      }
 169  }
 170  
 171  BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering)
 172  {
 173      // build a large-ish chain that's likely to have some forks
 174      std::vector<std::shared_ptr<const CBlock>> blocks;
 175      while (blocks.size() < 50) {
 176          blocks.clear();
 177          BuildChain(Params().GenesisBlock().GetHash(), 100, 15, 10, 500, blocks);
 178      }
 179  
 180      bool ignored;
 181      // Connect the genesis block and drain any outstanding events
 182      BOOST_CHECK(Assert(m_node.chainman)->ProcessNewBlock(std::make_shared<CBlock>(Params().GenesisBlock()), true, true, &ignored));
 183      m_node.validation_signals->SyncWithValidationInterfaceQueue();
 184  
 185      // subscribe to events (this subscriber will validate event ordering)
 186      const CBlockIndex* initial_tip = nullptr;
 187      {
 188          LOCK(cs_main);
 189          initial_tip = m_node.chainman->ActiveChain().Tip();
 190      }
 191      auto sub = std::make_shared<TestSubscriber>(initial_tip->GetBlockHash());
 192      m_node.validation_signals->RegisterSharedValidationInterface(sub);
 193  
 194      // create a bunch of threads that repeatedly process a block generated above at random
 195      // this will create parallelism and randomness inside validation - the ValidationInterface
 196      // will subscribe to events generated during block validation and assert on ordering invariance
 197      std::vector<std::thread> threads;
 198      threads.reserve(10);
 199      for (int i = 0; i < 10; i++) {
 200          threads.emplace_back([&]() {
 201              bool ignored;
 202              FastRandomContext insecure;
 203              for (int i = 0; i < 1000; i++) {
 204                  const auto& block = blocks[insecure.randrange(blocks.size() - 1)];
 205                  Assert(m_node.chainman)->ProcessNewBlock(block, true, true, &ignored);
 206              }
 207  
 208              // to make sure that eventually we process the full chain - do it here
 209              for (const auto& block : blocks) {
 210                  if (block->vtx.size() == 1) {
 211                      bool processed = Assert(m_node.chainman)->ProcessNewBlock(block, true, true, &ignored);
 212                      assert(processed);
 213                  }
 214              }
 215          });
 216      }
 217  
 218      for (auto& t : threads) {
 219          t.join();
 220      }
 221      m_node.validation_signals->SyncWithValidationInterfaceQueue();
 222  
 223      m_node.validation_signals->UnregisterSharedValidationInterface(sub);
 224  
 225      LOCK(cs_main);
 226      BOOST_CHECK_EQUAL(sub->m_expected_tip, m_node.chainman->ActiveChain().Tip()->GetBlockHash());
 227  }
 228  
 229  /**
 230   * Test that mempool updates happen atomically with reorgs.
 231   *
 232   * This prevents RPC clients, among others, from retrieving immediately-out-of-date mempool data
 233   * during large reorgs.
 234   *
 235   * The test verifies this by creating a chain of `num_txs` blocks, matures their coinbases, and then
 236   * submits txns spending from their coinbase to the mempool. A fork chain is then processed,
 237   * invalidating the txns and evicting them from the mempool.
 238   *
 239   * We verify that the mempool updates atomically by polling it continuously
 240   * from another thread during the reorg and checking that its size only changes
 241   * once. The size changing exactly once indicates that the polling thread's
 242   * view of the mempool is either consistent with the chain state before reorg,
 243   * or consistent with the chain state after the reorg, and not just consistent
 244   * with some intermediate state during the reorg.
 245   */
 246  BOOST_AUTO_TEST_CASE(mempool_locks_reorg)
 247  {
 248      bool ignored;
 249      auto ProcessBlock = [&](std::shared_ptr<const CBlock> block) -> bool {
 250          return Assert(m_node.chainman)->ProcessNewBlock(block, /*force_processing=*/true, /*min_pow_checked=*/true, /*new_block=*/&ignored);
 251      };
 252  
 253      // Process all mined blocks
 254      BOOST_REQUIRE(ProcessBlock(std::make_shared<CBlock>(Params().GenesisBlock())));
 255      auto last_mined = GoodBlock(Params().GenesisBlock().GetHash());
 256      BOOST_REQUIRE(ProcessBlock(last_mined));
 257  
 258      // Run the test multiple times
 259      for (int test_runs = 3; test_runs > 0; --test_runs) {
 260          BOOST_CHECK_EQUAL(last_mined->GetHash(), WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain().Tip()->GetBlockHash()));
 261  
 262          // Later on split from here
 263          const uint256 split_hash{last_mined->hashPrevBlock};
 264  
 265          // Create a bunch of transactions to spend the miner rewards of the
 266          // most recent blocks
 267          std::vector<CTransactionRef> txs;
 268          for (int num_txs = 22; num_txs > 0; --num_txs) {
 269              CMutableTransaction mtx;
 270              mtx.vin.emplace_back(COutPoint{last_mined->vtx[0]->GetHash(), 1}, CScript{});
 271              mtx.vin[0].scriptWitness.stack.push_back(WITNESS_STACK_ELEM_OP_TRUE);
 272              mtx.vout.push_back(last_mined->vtx[0]->vout[1]);
 273              mtx.vout[0].nValue -= 1000;
 274              txs.push_back(MakeTransactionRef(mtx));
 275  
 276              last_mined = GoodBlock(last_mined->GetHash());
 277              BOOST_REQUIRE(ProcessBlock(last_mined));
 278          }
 279  
 280          // Mature the inputs of the txs
 281          for (int j = COINBASE_MATURITY; j > 0; --j) {
 282              last_mined = GoodBlock(last_mined->GetHash());
 283              BOOST_REQUIRE(ProcessBlock(last_mined));
 284          }
 285  
 286          // Mine a reorg (and hold it back) before adding the txs to the mempool
 287          const uint256 tip_init{last_mined->GetHash()};
 288  
 289          std::vector<std::shared_ptr<const CBlock>> reorg;
 290          last_mined = GoodBlock(split_hash);
 291          reorg.push_back(last_mined);
 292          for (size_t j = COINBASE_MATURITY + txs.size() + 1; j > 0; --j) {
 293              last_mined = GoodBlock(last_mined->GetHash());
 294              reorg.push_back(last_mined);
 295          }
 296  
 297          // Add the txs to the tx pool
 298          {
 299              LOCK(cs_main);
 300              for (const auto& tx : txs) {
 301                  const MempoolAcceptResult result = m_node.chainman->ProcessTransaction(tx);
 302                  BOOST_REQUIRE(result.m_result_type == MempoolAcceptResult::ResultType::VALID);
 303              }
 304          }
 305  
 306          // Check that all txs are in the pool
 307          {
 308              BOOST_CHECK_EQUAL(m_node.mempool->size(), txs.size());
 309          }
 310  
 311          // Run a thread that simulates an RPC caller that is polling while
 312          // validation is doing a reorg
 313          std::thread rpc_thread{[&]() {
 314              // This thread is checking that the mempool either contains all of
 315              // the transactions invalidated by the reorg, or none of them, and
 316              // not some intermediate amount.
 317              while (true) {
 318                  LOCK(m_node.mempool->cs);
 319                  if (m_node.mempool->size() == 0) {
 320                      // We are done with the reorg
 321                      break;
 322                  }
 323                  // Internally, we might be in the middle of the reorg, but
 324                  // externally the reorg to the most-proof-of-work chain should
 325                  // be atomic. So the caller assumes that the returned mempool
 326                  // is consistent. That is, it has all txs that were there
 327                  // before the reorg.
 328                  assert(m_node.mempool->size() == txs.size());
 329                  continue;
 330              }
 331              LOCK(cs_main);
 332              // We are done with the reorg, so the tip must have changed
 333              assert(tip_init != m_node.chainman->ActiveChain().Tip()->GetBlockHash());
 334          }};
 335  
 336          // Submit the reorg in this thread to invalidate and remove the txs from the tx pool
 337          for (const auto& b : reorg) {
 338              ProcessBlock(b);
 339          }
 340          // Check that the reorg was eventually successful
 341          BOOST_CHECK_EQUAL(last_mined->GetHash(), WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain().Tip()->GetBlockHash()));
 342  
 343          // We can join the other thread, which returns when the reorg was successful
 344          rpc_thread.join();
 345      }
 346  }
 347  
 348  BOOST_AUTO_TEST_CASE(witness_commitment_index)
 349  {
 350      LOCK(Assert(m_node.chainman)->GetMutex());
 351      CScript pubKey;
 352      pubKey << 1 << OP_TRUE;
 353      auto mining{interfaces::MakeMining(m_node)};
 354      auto block_template{mining->createNewBlock({
 355          .coinbase_output_script = pubKey,
 356      }, /*cooldown=*/false)};
 357      BOOST_REQUIRE(block_template);
 358      CBlock pblock{block_template->getBlock()};
 359  
 360      CTxOut witness;
 361      witness.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT);
 362      witness.scriptPubKey[0] = OP_RETURN;
 363      witness.scriptPubKey[1] = 0x24;
 364      witness.scriptPubKey[2] = 0xaa;
 365      witness.scriptPubKey[3] = 0x21;
 366      witness.scriptPubKey[4] = 0xa9;
 367      witness.scriptPubKey[5] = 0xed;
 368  
 369      // A witness larger than the minimum size is still valid
 370      CTxOut min_plus_one = witness;
 371      min_plus_one.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT + 1);
 372  
 373      CTxOut invalid = witness;
 374      invalid.scriptPubKey[0] = OP_VERIFY;
 375  
 376      CMutableTransaction txCoinbase(*pblock.vtx[0]);
 377      txCoinbase.vout.resize(4);
 378      txCoinbase.vout[0] = witness;
 379      txCoinbase.vout[1] = witness;
 380      txCoinbase.vout[2] = min_plus_one;
 381      txCoinbase.vout[3] = invalid;
 382      pblock.vtx[0] = MakeTransactionRef(std::move(txCoinbase));
 383  
 384      BOOST_CHECK_EQUAL(GetWitnessCommitmentIndex(pblock), 2);
 385  }
 386  BOOST_AUTO_TEST_SUITE_END()
 387