Line data    Source code

       1             : #include <arith_uint256.h>
       2             : #include <chain.h>
       3             : #include <chainparams.h>
       4             : #include <headerssync.h>
       5             : #include <test/fuzz/fuzz.h>
       6             : #include <test/fuzz/util.h>
       7             : #include <test/util/setup_common.h>
       8             : #include <uint256.h>
       9             : #include <util/chaintype.h>
      10             : #include <util/time.h>
      11             : #include <validation.h>
      12             : 
      13             : #include <iterator>
      14             : #include <vector>
      15             : 
      16           0 : static void initialize_headers_sync_state_fuzz()
      17           2 : {
      18           2 :     static const auto testing_setup = MakeNoLogFileContext<>(
      19             :         /*chain_type=*/ChainType::MAIN);
      20           0 : }
      21             : 
      22           0 : void MakeHeadersContinuous(
      23             :     const CBlockHeader& genesis_header,
      24             :     const std::vector<CBlockHeader>& all_headers,
      25             :     std::vector<CBlockHeader>& new_headers)
      26             : {
      27           0 :     Assume(!new_headers.empty());
      28             : 
      29           0 :     const CBlockHeader* prev_header{
      30           0 :         all_headers.empty() ? &genesis_header : &all_headers.back()};
      31             : 
      32           0 :     for (auto& header : new_headers) {
      33           0 :         header.hashPrevBlock = prev_header->GetHash();
      34             : 
      35           0 :         prev_header = &header;
      36             :     }
      37           0 : }
      38             : 
      39             : class FuzzedHeadersSyncState : public HeadersSyncState
      40             : {
      41             : public:
      42           0 :     FuzzedHeadersSyncState(const unsigned commit_offset, const CBlockIndex* chain_start, const arith_uint256& minimum_required_work)
      43           0 :         : HeadersSyncState(/*id=*/0, Params().GetConsensus(), chain_start, minimum_required_work)
      44             :     {
      45           0 :         const_cast<unsigned&>(m_commit_offset) = commit_offset;
      46           0 :     }
      47             : };
      48             : 
      49           4 : FUZZ_TARGET(headers_sync_state, .init = initialize_headers_sync_state_fuzz)
      50             : {
      51           0 :     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
      52           0 :     auto mock_time{ConsumeTime(fuzzed_data_provider)};
      53             : 
      54           0 :     CBlockHeader genesis_header{Params().GenesisBlock()};
      55           0 :     CBlockIndex start_index(genesis_header);
      56             : 
      57           0 :     if (mock_time < start_index.GetMedianTimePast()) return;
      58           0 :     SetMockTime(mock_time);
      59             : 
      60           0 :     const uint256 genesis_hash = genesis_header.GetHash();
      61           0 :     start_index.phashBlock = &genesis_hash;
      62             : 
      63           0 :     arith_uint256 min_work{UintToArith256(ConsumeUInt256(fuzzed_data_provider))};
      64           0 :     FuzzedHeadersSyncState headers_sync(
      65           0 :         /*commit_offset=*/fuzzed_data_provider.ConsumeIntegralInRange<unsigned>(1, 1024),
      66             :         /*chain_start=*/&start_index,
      67             :         /*minimum_required_work=*/min_work);
      68             : 
      69             :     // Store headers for potential redownload phase.
      70           0 :     std::vector<CBlockHeader> all_headers;
      71           0 :     std::vector<CBlockHeader>::const_iterator redownloaded_it;
      72           0 :     bool presync{true};
      73           0 :     bool requested_more{true};
      74           2 : 
      75           0 :     while (requested_more) {
      76           0 :         std::vector<CBlockHeader> headers;
      77             : 
      78             :         // Consume headers from fuzzer or maybe replay headers if we got to the
      79             :         // redownload phase.
      80           0 :         if (presync || fuzzed_data_provider.ConsumeBool()) {
      81           0 :             auto deser_headers = ConsumeDeserializable<std::vector<CBlockHeader>>(fuzzed_data_provider);
      82           0 :             if (!deser_headers || deser_headers->empty()) return;
      83           2 : 
      84           0 :             if (fuzzed_data_provider.ConsumeBool()) {
      85           0 :                 MakeHeadersContinuous(genesis_header, all_headers, *deser_headers);
      86           0 :             }
      87             : 
      88           0 :             headers.swap(*deser_headers);
      89           0 :         } else if (auto num_headers_left{std::distance(redownloaded_it, all_headers.cend())}; num_headers_left > 0) {
      90             :             // Consume some headers from the redownload buffer (At least one
      91             :             // header is consumed).
      92           0 :             auto begin_it{redownloaded_it};
      93           0 :             std::advance(redownloaded_it, fuzzed_data_provider.ConsumeIntegralInRange<int>(1, num_headers_left));
      94           0 :             headers.insert(headers.cend(), begin_it, redownloaded_it);
      95           0 :         }
      96             : 
      97           0 :         if (headers.empty()) return;
      98           0 :         auto result = headers_sync.ProcessNextHeaders(headers, fuzzed_data_provider.ConsumeBool());
      99           0 :         requested_more = result.request_more;
     100             : 
     101           0 :         if (result.request_more) {
     102           0 :             if (presync) {
     103           0 :                 all_headers.insert(all_headers.cend(), headers.cbegin(), headers.cend());
     104             : 
     105           0 :                 if (headers_sync.GetState() == HeadersSyncState::State::REDOWNLOAD) {
     106           0 :                     presync = false;
     107           0 :                     redownloaded_it = all_headers.cbegin();
     108             : 
     109             :                     // If we get to redownloading, the presynced headers need
     110             :                     // to have the min amount of work on them.
     111           0 :                     assert(CalculateHeadersWork(all_headers) >= min_work);
     112           0 :                 }
     113           0 :             }
     114             : 
     115           0 :             (void)headers_sync.NextHeadersRequestLocator();
     116           0 :         }
     117           0 :     }
     118           0 : }