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Merged
ryanofsky merged 1 commit into from
Jul 9, 2024
Merged

fuzz: improve utxo_snapshot target #30329

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9 changes: 8 additions & 1 deletion src/kernel/chainparams.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -495,12 +495,19 @@ class CRegTestParams : public CChainParams
};

m_assumeutxo_data = {
{
{ // For use by unit tests

@maflcko maflcko Jul 3, 2024

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nit: maybe also list the filename here, like in the other cases.

@mzumsande mzumsande Jul 5, 2024

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I didn't do that because there are already multiple files that use it (validation_chainstatemanager_tests, validation_chainstate_tests). Seems less likely that the same would happen for fuzz tests.

.height = 110,
.hash_serialized = AssumeutxoHash{uint256S("0x6657b736d4fe4db0cbc796789e812d5dba7f5c143764b1b6905612f1830609d1")},
.nChainTx = 111,
.blockhash = uint256S("0x696e92821f65549c7ee134edceeeeaaa4105647a3c4fd9f298c0aec0ab50425c")
},
{
// For use by fuzz target src/test/fuzz/utxo_snapshot.cpp
.height = 200,
.hash_serialized = AssumeutxoHash{uint256S("0x4f34d431c3e482f6b0d67b64609ece3964dc8d7976d02ac68dd7c9c1421738f2")},
.nChainTx = 201,
.blockhash = uint256S("0x5e93653318f294fb5aa339d00bbf8cf1c3515488ad99412c37608b139ea63b27"),
Comment on lines +506 to +509

@ryanofsky ryanofsky Jul 9, 2024

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In commit "fuzz: improve utxo_snapshot target" (de71d4d)

Since fuzz test is not deterministic, and doesn't give us an easy way to know hash values here actually allow snapshot to be loaded, it might be good to write a separate regtest generating a an empty chain with height 200 and verifying these hashes.

},
{
// For use by test/functional/feature_assumeutxo.py
.height = 299,
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46 changes: 38 additions & 8 deletions src/test/fuzz/utxo_snapshot.cpp
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Expand Up @@ -41,13 +41,39 @@ FUZZ_TARGET(utxo_snapshot, .init = initialize_chain)

{
AutoFile outfile{fsbridge::fopen(snapshot_path, "wb")};
const auto file_data{ConsumeRandomLengthByteVector(fuzzed_data_provider)};
outfile << Span{file_data};
// Metadata
if (fuzzed_data_provider.ConsumeBool()) {
std::vector<uint8_t> metadata{ConsumeRandomLengthByteVector(fuzzed_data_provider)};
outfile << Span{metadata};
} else {
DataStream data_stream{};
auto msg_start = chainman.GetParams().MessageStart();
int base_blockheight{fuzzed_data_provider.ConsumeIntegralInRange<int>(1, 2 * COINBASE_MATURITY)};
uint256 base_blockhash{g_chain->at(base_blockheight - 1)->GetHash()};
uint64_t m_coins_count{fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(1, 3 * COINBASE_MATURITY)};
SnapshotMetadata metadata{msg_start, base_blockhash, base_blockheight, m_coins_count};
outfile << metadata;
}
// Coins
if (fuzzed_data_provider.ConsumeBool()) {
std::vector<uint8_t> file_data{ConsumeRandomLengthByteVector(fuzzed_data_provider)};
outfile << Span{file_data};
} else {
int height{0};
for (const auto& block : *g_chain) {
auto coinbase{block->vtx.at(0)};
outfile << coinbase->GetHash();
WriteCompactSize(outfile, 1); // number of coins for the hash
WriteCompactSize(outfile, 0); // index of coin
outfile << Coin(coinbase->vout[0], height, /*fCoinBaseIn=*/1);
height++;
}
}
}

const auto ActivateFuzzedSnapshot{[&] {
AutoFile infile{fsbridge::fopen(snapshot_path, "rb")};
auto msg_start = Params().MessageStart();
auto msg_start = chainman.GetParams().MessageStart();
SnapshotMetadata metadata{msg_start};
try {
infile >> metadata;
Expand All @@ -73,16 +99,20 @@ FUZZ_TARGET(utxo_snapshot, .init = initialize_chain)
Assert(*chainman.ActiveChainstate().m_from_snapshot_blockhash ==
*chainman.SnapshotBlockhash());
const auto& coinscache{chainman.ActiveChainstate().CoinsTip()};
int64_t chain_tx{};
for (const auto& block : *g_chain) {
Assert(coinscache.HaveCoin(COutPoint{block->vtx.at(0)->GetHash(), 0}));
const auto* index{chainman.m_blockman.LookupBlockIndex(block->GetHash())};
const auto num_tx{Assert(index)->nTx};
Assert(num_tx == 1);
chain_tx += num_tx;
Assert(index);
Assert(index->nTx == 0);
if (index->nHeight == chainman.GetSnapshotBaseHeight()) {
auto params{chainman.GetParams().AssumeutxoForHeight(index->nHeight)};
Assert(params.has_value());
Assert(params.value().nChainTx == index->nChainTx);
} else {
Assert(index->nChainTx == 0);
}
}
Assert(g_chain->size() == coinscache.GetCacheSize());
Assert(chain_tx == chainman.ActiveTip()->nChainTx);
} else {
Assert(!chainman.SnapshotBlockhash());
Assert(!chainman.ActiveChainstate().m_from_snapshot_blockhash);
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2 changes: 1 addition & 1 deletion test/functional/feature_assumeutxo.py
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Expand Up @@ -117,7 +117,7 @@ def expected_error(log_msg="", rpc_details=""):
with open(bad_snapshot_path, 'wb') as f:
f.write(valid_snapshot_contents[:11] + bogus_height.to_bytes(4, "little") + bytes.fromhex(bad_block_hash)[::-1] + valid_snapshot_contents[47:])

msg = f"Unable to load UTXO snapshot: assumeutxo block hash in snapshot metadata not recognized (hash: {bad_block_hash}, height: {bogus_height}). The following snapshot heights are available: 110, 299."
msg = f"Unable to load UTXO snapshot: assumeutxo block hash in snapshot metadata not recognized (hash: {bad_block_hash}, height: {bogus_height}). The following snapshot heights are available: 110, 200, 299."
assert_raises_rpc_error(-32603, msg, node.loadtxoutset, bad_snapshot_path)

self.log.info(" - snapshot file with wrong number of coins")
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