From 17a8ffd8020375d60428695858558f2be264aa36 Mon Sep 17 00:00:00 2001 From: glozow Date: Tue, 20 Jul 2021 13:26:26 +0100 Subject: [packages/policy] use package feerate in package validation This allows CPFP within a package prior to submission to mempool. --- src/test/fuzz/tx_pool.cpp | 14 +++++++++----- src/validation.cpp | 45 +++++++++++++++++++++++++++++++++++---------- src/validation.h | 8 ++++++++ 3 files changed, 52 insertions(+), 15 deletions(-) (limited to 'src') diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp index df5b271d06..f686f4fd86 100644 --- a/src/test/fuzz/tx_pool.cpp +++ b/src/test/fuzz/tx_pool.cpp @@ -234,14 +234,18 @@ FUZZ_TARGET_INIT(tx_pool_standard, initialize_tx_pool) const bool bypass_limits = fuzzed_data_provider.ConsumeBool(); ::fRequireStandard = fuzzed_data_provider.ConsumeBool(); - // Make sure ProcessNewPackage on one transaction works and always fully validates the transaction. + // Make sure ProcessNewPackage on one transaction works. // The result is not guaranteed to be the same as what is returned by ATMP. const auto result_package = WITH_LOCK(::cs_main, return ProcessNewPackage(chainstate, tx_pool, {tx}, true)); - auto it = result_package.m_tx_results.find(tx->GetWitnessHash()); - Assert(it != result_package.m_tx_results.end()); - Assert(it->second.m_result_type == MempoolAcceptResult::ResultType::VALID || - it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID); + // If something went wrong due to a package-specific policy, it might not return a + // validation result for the transaction. + if (result_package.m_state.GetResult() != PackageValidationResult::PCKG_POLICY) { + auto it = result_package.m_tx_results.find(tx->GetWitnessHash()); + Assert(it != result_package.m_tx_results.end()); + Assert(it->second.m_result_type == MempoolAcceptResult::ResultType::VALID || + it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID); + } const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx, GetTime(), bypass_limits, /*test_accept=*/false)); const bool accepted = res.m_result_type == MempoolAcceptResult::ResultType::VALID; diff --git a/src/validation.cpp b/src/validation.cpp index 6db13f1f70..42c2189668 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -460,6 +460,10 @@ public: * partially submitted. */ const bool m_package_submission; + /** When true, use package feerates instead of individual transaction feerates for fee-based + * policies such as mempool min fee and min relay fee. + */ + const bool m_package_feerates; /** Parameters for single transaction mempool validation. */ static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time, @@ -472,6 +476,7 @@ public: /* m_test_accept */ test_accept, /* m_allow_bip125_replacement */ true, /* m_package_submission */ false, + /* m_package_feerates */ false, }; } @@ -485,6 +490,7 @@ public: /* m_test_accept */ true, /* m_allow_bip125_replacement */ false, /* m_package_submission */ false, // not submitting to mempool + /* m_package_feerates */ false, }; } @@ -498,6 +504,7 @@ public: /* m_test_accept */ false, /* m_allow_bip125_replacement */ false, /* m_package_submission */ true, + /* m_package_feerates */ true, }; } @@ -510,14 +517,16 @@ public: std::vector& coins_to_uncache, bool test_accept, bool allow_bip125_replacement, - bool package_submission) + bool package_submission, + bool package_feerates) : m_chainparams{chainparams}, m_accept_time{accept_time}, m_bypass_limits{bypass_limits}, m_coins_to_uncache{coins_to_uncache}, m_test_accept{test_accept}, m_allow_bip125_replacement{allow_bip125_replacement}, - m_package_submission{package_submission} + m_package_submission{package_submission}, + m_package_feerates{package_feerates} { } }; @@ -819,9 +828,10 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws) return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops", strprintf("%d", nSigOpsCost)); - // No transactions are allowed below minRelayTxFee except from disconnected - // blocks - if (!bypass_limits && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false; + // No individual transactions are allowed below minRelayTxFee and mempool min fee except from + // disconnected blocks and transactions in a package. Package transactions will be checked using + // package feerate later. + if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false; ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts); // Calculate in-mempool ancestors, up to a limit. @@ -1205,12 +1215,27 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std:: m_viewmempool.PackageAddTransaction(ws.m_ptx); } + // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee. + // For transactions consisting of exactly one child and its parents, it suffices to use the + // package feerate (total modified fees / total virtual size) to check this requirement. + const auto m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0}, + [](int64_t sum, auto& ws) { return sum + ws.m_vsize; }); + const auto m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0}, + [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; }); + const CFeeRate package_feerate(m_total_modified_fees, m_total_vsize); + TxValidationState placeholder_state; + if (args.m_package_feerates && + !CheckFeeRate(m_total_vsize, m_total_modified_fees, placeholder_state)) { + package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-fee-too-low"); + return PackageMempoolAcceptResult(package_state, package_feerate, {}); + } + // Apply package mempool ancestor/descendant limits. Skip if there is only one transaction, // because it's unnecessary. Also, CPFP carve out can increase the limit for individual // transactions, but this exemption is not extended to packages in CheckPackageLimits(). std::string err_string; if (txns.size() > 1 && !PackageMempoolChecks(txns, package_state)) { - return PackageMempoolAcceptResult(package_state, std::move(results)); + return PackageMempoolAcceptResult(package_state, package_feerate, std::move(results)); } for (Workspace& ws : workspaces) { @@ -1218,7 +1243,7 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std:: // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); - return PackageMempoolAcceptResult(package_state, std::move(results)); + return PackageMempoolAcceptResult(package_state, package_feerate, std::move(results)); } if (args.m_test_accept) { // When test_accept=true, transactions that pass PolicyScriptChecks are valid because there are @@ -1229,14 +1254,14 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std:: } } - if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results)); + if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, package_feerate, std::move(results)); if (!SubmitPackage(args, workspaces, package_state, results)) { // PackageValidationState filled in by SubmitPackage(). - return PackageMempoolAcceptResult(package_state, std::move(results)); + return PackageMempoolAcceptResult(package_state, package_feerate, std::move(results)); } - return PackageMempoolAcceptResult(package_state, std::move(results)); + return PackageMempoolAcceptResult(package_state, package_feerate, std::move(results)); } PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args) diff --git a/src/validation.h b/src/validation.h index b13e7f3d8b..53ea2d4aea 100644 --- a/src/validation.h +++ b/src/validation.h @@ -234,11 +234,19 @@ struct PackageMempoolAcceptResult * was a package-wide error (see result in m_state), m_tx_results will be empty. */ std::map m_tx_results; + /** Package feerate, defined as the aggregated modified fees divided by the total virtual size + * of all transactions in the package. May be unavailable if some inputs were not available or + * a transaction failure caused validation to terminate early. */ + std::optional m_package_feerate; explicit PackageMempoolAcceptResult(PackageValidationState state, std::map&& results) : m_state{state}, m_tx_results(std::move(results)) {} + explicit PackageMempoolAcceptResult(PackageValidationState state, CFeeRate feerate, + std::map&& results) + : m_state{state}, m_tx_results(std::move(results)), m_package_feerate{feerate} {} + /** Constructor to create a PackageMempoolAcceptResult from a single MempoolAcceptResult */ explicit PackageMempoolAcceptResult(const uint256& wtxid, const MempoolAcceptResult& result) : m_tx_results{ {wtxid, result} } {} -- cgit v1.2.3