1  // Copyright (c) 2023 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 <node/blockstorage.h>
  8  #include <test/fuzz/FuzzedDataProvider.h>
  9  #include <test/fuzz/fuzz.h>
 10  #include <test/fuzz/util.h>
 11  #include <test/util/setup_common.h>
 12  #include <txdb.h>
 13  #include <validation.h>
 14  
 15  namespace {
 16  
 17  const BasicTestingSetup* g_setup;
 18  
 19  // Hardcoded block hash and nBits to make sure the blocks we store pass the pow check.
 20  uint256 g_block_hash;
 21  
 22  bool operator==(const CBlockFileInfo& a, const CBlockFileInfo& b)
 23  {
 24      return a.nBlocks == b.nBlocks &&
 25          a.nSize == b.nSize &&
 26          a.nUndoSize == b.nUndoSize &&
 27          a.nHeightFirst == b.nHeightFirst &&
 28          a.nHeightLast == b.nHeightLast &&
 29          a.nTimeFirst == b.nTimeFirst &&
 30          a.nTimeLast == b.nTimeLast;
 31  }
 32  
 33  CBlockHeader ConsumeBlockHeader(FuzzedDataProvider& provider)
 34  {
 35      CBlockHeader header;
 36      header.nVersion = provider.ConsumeIntegral<decltype(header.nVersion)>();
 37      header.hashPrevBlock = g_block_hash;
 38      header.hashMerkleRoot = g_block_hash;
 39      header.nTime = provider.ConsumeIntegral<decltype(header.nTime)>();
 40      header.nBits = Params().GenesisBlock().nBits;
 41      header.nNonce = provider.ConsumeIntegral<decltype(header.nNonce)>();
 42      return header;
 43  }
 44  
 45  } // namespace
 46  
 47  void init_block_index()
 48  {
 49      static const auto testing_setup = MakeNoLogFileContext<>(ChainType::MAIN);
 50      g_setup = testing_setup.get();
 51      g_block_hash = Params().GenesisBlock().GetHash();
 52  }
 53  
 54  FUZZ_TARGET(block_index, .init = init_block_index)
 55  {
 56      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
 57      auto block_index = kernel::BlockTreeDB(DBParams{
 58          .path = "", // Memory only.
 59          .cache_bytes = 1 << 20, // 1MB.
 60          .memory_only = true,
 61      });
 62  
 63      // Generate a number of block files to be stored in the index.
 64      int files_count = fuzzed_data_provider.ConsumeIntegralInRange(1, 100);
 65      std::vector<std::unique_ptr<CBlockFileInfo>> files;
 66      files.reserve(files_count);
 67      std::vector<std::pair<int, const CBlockFileInfo*>> files_info;
 68      files_info.reserve(files_count);
 69      for (int i = 0; i < files_count; i++) {
 70          if (auto file_info = ConsumeDeserializable<CBlockFileInfo>(fuzzed_data_provider)) {
 71              files.push_back(std::make_unique<CBlockFileInfo>(std::move(*file_info)));
 72              files_info.emplace_back(i, files.back().get());
 73          } else {
 74              return;
 75          }
 76      }
 77  
 78      // Generate a number of block headers to be stored in the index.
 79      int blocks_count = fuzzed_data_provider.ConsumeIntegralInRange(files_count * 10, files_count * 100);
 80      std::vector<std::unique_ptr<CBlockIndex>> blocks;
 81      blocks.reserve(blocks_count);
 82      std::vector<const CBlockIndex*> blocks_info;
 83      blocks_info.reserve(blocks_count);
 84      for (int i = 0; i < blocks_count; i++) {
 85          CBlockHeader header{ConsumeBlockHeader(fuzzed_data_provider)};
 86          blocks.push_back(std::make_unique<CBlockIndex>(std::move(header)));
 87          blocks.back()->phashBlock = &g_block_hash;
 88          blocks_info.push_back(blocks.back().get());
 89      }
 90  
 91      // Store these files and blocks in the block index. It should not fail.
 92      assert(block_index.WriteBatchSync(files_info, files_count - 1, blocks_info));
 93  
 94      // We should be able to read every block file info we stored. Its value should correspond to
 95      // what we stored above.
 96      CBlockFileInfo info;
 97      for (const auto& [n, file_info]: files_info) {
 98          assert(block_index.ReadBlockFileInfo(n, info));
 99          assert(info == *file_info);
100      }
101  
102      // We should be able to read the last block file number. Its value should be consistent.
103      int last_block_file;
104      assert(block_index.ReadLastBlockFile(last_block_file));
105      assert(last_block_file == files_count - 1);
106  
107      // We should be able to flip and read the reindexing flag.
108      bool reindexing;
109      block_index.WriteReindexing(true);
110      block_index.ReadReindexing(reindexing);
111      assert(reindexing);
112      block_index.WriteReindexing(false);
113      block_index.ReadReindexing(reindexing);
114      assert(!reindexing);
115  
116      // We should be able to set and read the value of any random flag.
117      const std::string flag_name = fuzzed_data_provider.ConsumeRandomLengthString(100);
118      bool flag_value;
119      block_index.WriteFlag(flag_name, true);
120      block_index.ReadFlag(flag_name, flag_value);
121      assert(flag_value);
122      block_index.WriteFlag(flag_name, false);
123      block_index.ReadFlag(flag_name, flag_value);
124      assert(!flag_value);
125  
126      // We should be able to load everything we've previously stored. Note to assert on the
127      // return value we need to make sure all blocks pass the pow check.
128      const auto params{Params().GetConsensus()};
129      const auto inserter = [&](const uint256&) {
130          return blocks.back().get();
131      };
132      WITH_LOCK(::cs_main, assert(block_index.LoadBlockIndexGuts(params, inserter, g_setup->m_interrupt)));
133  }