1  // Copyright (c) 2023-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 <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  using kernel::CBlockFileInfo;
 16  
 17  namespace {
 18  
 19  const BasicTestingSetup* g_setup;
 20  
 21  // Hardcoded block hash and nBits to make sure the blocks we store pass the pow check.
 22  uint256 g_block_hash;
 23  
 24  bool operator==(const CBlockFileInfo& a, const CBlockFileInfo& b)
 25  {
 26      return a.nBlocks == b.nBlocks &&
 27          a.nSize == b.nSize &&
 28          a.nUndoSize == b.nUndoSize &&
 29          a.nHeightFirst == b.nHeightFirst &&
 30          a.nHeightLast == b.nHeightLast &&
 31          a.nTimeFirst == b.nTimeFirst &&
 32          a.nTimeLast == b.nTimeLast;
 33  }
 34  
 35  CBlockHeader ConsumeBlockHeader(FuzzedDataProvider& provider)
 36  {
 37      CBlockHeader header;
 38      header.nVersion = provider.ConsumeIntegral<decltype(header.nVersion)>();
 39      header.hashPrevBlock = g_block_hash;
 40      header.hashMerkleRoot = g_block_hash;
 41      header.nTime = provider.ConsumeIntegral<decltype(header.nTime)>();
 42      header.nBits = Params().GenesisBlock().nBits;
 43      header.nNonce = provider.ConsumeIntegral<decltype(header.nNonce)>();
 44      return header;
 45  }
 46  
 47  } // namespace
 48  
 49  void init_block_index()
 50  {
 51      static const auto testing_setup = MakeNoLogFileContext<>(ChainType::MAIN);
 52      g_setup = testing_setup.get();
 53      g_block_hash = Params().GenesisBlock().GetHash();
 54  }
 55  
 56  FUZZ_TARGET(block_index, .init = init_block_index)
 57  {
 58      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
 59      auto block_index = kernel::BlockTreeDB(DBParams{
 60          .path = "", // Memory only.
 61          .cache_bytes = 1 << 20, // 1MB.
 62          .memory_only = true,
 63      });
 64  
 65      // Generate a number of block files to be stored in the index.
 66      int files_count = fuzzed_data_provider.ConsumeIntegralInRange(1, 100);
 67      std::vector<std::unique_ptr<CBlockFileInfo>> files;
 68      files.reserve(files_count);
 69      std::vector<std::pair<int, const CBlockFileInfo*>> files_info;
 70      files_info.reserve(files_count);
 71      for (int i = 0; i < files_count; i++) {
 72          if (auto file_info = ConsumeDeserializable<CBlockFileInfo>(fuzzed_data_provider)) {
 73              files.push_back(std::make_unique<CBlockFileInfo>(std::move(*file_info)));
 74              files_info.emplace_back(i, files.back().get());
 75          } else {
 76              return;
 77          }
 78      }
 79  
 80      // Generate a number of block headers to be stored in the index.
 81      int blocks_count = fuzzed_data_provider.ConsumeIntegralInRange(files_count * 10, files_count * 100);
 82      std::vector<std::unique_ptr<CBlockIndex>> blocks;
 83      blocks.reserve(blocks_count);
 84      std::vector<const CBlockIndex*> blocks_info;
 85      blocks_info.reserve(blocks_count);
 86      for (int i = 0; i < blocks_count; i++) {
 87          CBlockHeader header{ConsumeBlockHeader(fuzzed_data_provider)};
 88          blocks.push_back(std::make_unique<CBlockIndex>(std::move(header)));
 89          blocks.back()->phashBlock = &g_block_hash;
 90          blocks_info.push_back(blocks.back().get());
 91      }
 92  
 93      // Store these files and blocks in the block index. It should not fail.
 94      block_index.WriteBatchSync(files_info, files_count - 1, blocks_info);
 95  
 96      // We should be able to read every block file info we stored. Its value should correspond to
 97      // what we stored above.
 98      CBlockFileInfo info;
 99      for (const auto& [n, file_info]: files_info) {
100          assert(block_index.ReadBlockFileInfo(n, info));
101          assert(info == *file_info);
102      }
103  
104      // We should be able to read the last block file number. Its value should be consistent.
105      int last_block_file;
106      assert(block_index.ReadLastBlockFile(last_block_file));
107      assert(last_block_file == files_count - 1);
108  
109      // We should be able to flip and read the reindexing flag.
110      bool reindexing;
111      block_index.WriteReindexing(true);
112      block_index.ReadReindexing(reindexing);
113      assert(reindexing);
114      block_index.WriteReindexing(false);
115      block_index.ReadReindexing(reindexing);
116      assert(!reindexing);
117  
118      // We should be able to set and read the value of any random flag.
119      const std::string flag_name = fuzzed_data_provider.ConsumeRandomLengthString(100);
120      bool flag_value;
121      block_index.WriteFlag(flag_name, true);
122      block_index.ReadFlag(flag_name, flag_value);
123      assert(flag_value);
124      block_index.WriteFlag(flag_name, false);
125      block_index.ReadFlag(flag_name, flag_value);
126      assert(!flag_value);
127  
128      // We should be able to load everything we've previously stored. Note to assert on the
129      // return value we need to make sure all blocks pass the pow check.
130      const auto params{Params().GetConsensus()};
131      const auto inserter = [&](const uint256&) {
132          return blocks.back().get();
133      };
134      WITH_LOCK(::cs_main, assert(block_index.LoadBlockIndexGuts(params, inserter, g_setup->m_interrupt)));
135  }