1  // Copyright (c) 2023-present The Bitcoin Core developers
  2  // Distributed under the MIT software license, see the accompanying
  3  // file COPYING or https://opensource.org/license/mit.
  4  
  5  #include <blockencodings.h>
  6  #include <consensus/merkle.h>
  7  #include <consensus/validation.h>
  8  #include <primitives/block.h>
  9  #include <primitives/transaction.h>
 10  #include <test/fuzz/FuzzedDataProvider.h>
 11  #include <test/fuzz/fuzz.h>
 12  #include <test/fuzz/util.h>
 13  #include <test/fuzz/util/mempool.h>
 14  #include <test/util/setup_common.h>
 15  #include <test/util/time.h>
 16  #include <test/util/txmempool.h>
 17  #include <txmempool.h>
 18  #include <util/check.h>
 19  #include <util/time.h>
 20  #include <util/translation.h>
 21  
 22  #include <cstddef>
 23  #include <cstdint>
 24  #include <limits>
 25  #include <memory>
 26  #include <optional>
 27  #include <set>
 28  #include <vector>
 29  
 30  namespace {
 31  const TestingSetup* g_setup;
 32  } // namespace
 33  
 34  void initialize_pdb()
 35  {
 36      static const auto testing_setup = MakeNoLogFileContext<const TestingSetup>();
 37      g_setup = testing_setup.get();
 38  }
 39  
 40  PartiallyDownloadedBlock::IsBlockMutatedFn FuzzedIsBlockMutated(bool result)
 41  {
 42      return [result](const CBlock& block, bool) {
 43          return result;
 44      };
 45  }
 46  
 47  FUZZ_TARGET(partially_downloaded_block, .init = initialize_pdb)
 48  {
 49      SeedRandomStateForTest(SeedRand::ZEROS);
 50      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
 51      NodeClockContext clock_ctx{ConsumeTime(fuzzed_data_provider)};
 52  
 53      auto block{ConsumeDeserializable<CBlock>(fuzzed_data_provider, TX_WITH_WITNESS)};
 54      if (!block || block->vtx.size() == 0 ||
 55          block->vtx.size() >= std::numeric_limits<uint16_t>::max()) {
 56          return;
 57      }
 58  
 59      CBlockHeaderAndShortTxIDs cmpctblock{*block, fuzzed_data_provider.ConsumeIntegral<uint64_t>()};
 60  
 61      bilingual_str error;
 62      CTxMemPool pool{MemPoolOptionsForTest(g_setup->m_node), error};
 63      Assert(error.empty());
 64      PartiallyDownloadedBlock pdb{&pool};
 65  
 66      // Set of available transactions (mempool or extra_txn)
 67      std::set<uint16_t> available;
 68      // The coinbase is always available
 69      available.insert(0);
 70  
 71      std::vector<std::pair<Wtxid, CTransactionRef>> extra_txn;
 72      for (size_t i = 1; i < block->vtx.size(); ++i) {
 73          auto tx{block->vtx[i]};
 74  
 75          bool add_to_extra_txn{fuzzed_data_provider.ConsumeBool()};
 76          bool add_to_mempool{fuzzed_data_provider.ConsumeBool()};
 77  
 78          if (add_to_extra_txn) {
 79              extra_txn.emplace_back(tx->GetWitnessHash(), tx);
 80              available.insert(i);
 81          }
 82  
 83          if (add_to_mempool && !pool.exists(tx->GetHash())) {
 84              LOCK2(cs_main, pool.cs);
 85              TryAddToMempool(pool, ConsumeTxMemPoolEntry(fuzzed_data_provider, *tx));
 86              available.insert(i);
 87          }
 88      }
 89  
 90      auto init_status{pdb.InitData(cmpctblock, extra_txn)};
 91  
 92      std::vector<CTransactionRef> missing;
 93      // Whether we skipped a transaction that should be included in `missing`.
 94      // FillBlock should never return READ_STATUS_OK if that is the case.
 95      bool skipped_missing{false};
 96      for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
 97          // If init_status == READ_STATUS_OK then a available transaction in the
 98          // compact block (i.e. IsTxAvailable(i) == true) implies that we marked
 99          // that transaction as available above (i.e. available.contains(i)).
100          // The reverse is not true, due to possible compact block short id
101          // collisions (i.e. available.contains(i) does not imply
102          // IsTxAvailable(i) == true).
103          if (init_status == READ_STATUS_OK) {
104              assert(!pdb.IsTxAvailable(i) || available.contains(i));
105          }
106  
107          bool skip{fuzzed_data_provider.ConsumeBool()};
108          if (!pdb.IsTxAvailable(i) && !skip) {
109              missing.push_back(block->vtx[i]);
110          }
111  
112          skipped_missing |= (!pdb.IsTxAvailable(i) && skip);
113      }
114  
115      bool segwit_active{fuzzed_data_provider.ConsumeBool()};
116  
117      // Mock IsBlockMutated
118      bool fail_block_mutated{fuzzed_data_provider.ConsumeBool()};
119      pdb.m_check_block_mutated_mock = FuzzedIsBlockMutated(fail_block_mutated);
120  
121      CBlock reconstructed_block;
122      auto fill_status{pdb.FillBlock(reconstructed_block, missing, segwit_active)};
123      switch (fill_status) {
124      case READ_STATUS_OK:
125          assert(!skipped_missing);
126          assert(!fail_block_mutated);
127          assert(block->GetHash() == reconstructed_block.GetHash());
128          break;
129      case READ_STATUS_FAILED:
130          assert(fail_block_mutated);
131          break;
132      case READ_STATUS_INVALID:
133          break;
134      }
135  }