From 0f0f979c062055c28383bd4b06f69be90380fe53 Mon Sep 17 00:00:00 2001 From: glozow Date: Fri, 22 Nov 2024 07:17:36 -0500 Subject: [PATCH 1/2] relax child-with-unconfirmed-parents rule This rule was originally introduced along with a very early proposal for package relay as a way to verify that the "correct" child-with-unconfirmed-parents package was provided for a transaction, where correctness was defined as all of the transactions unconfirmed parents. However, we are not planning to introduce a protocol where peers would be asked to send these packages. This rule has downsides: if a transaction has multiple parents but only 1 that requires package CPFP to be accepted, the current rule prevents us from accepting that package. Even if the other parents are already in mempool, the p2p logic will only submit the 1p1c package, which fails this check. See the test in p2p_1p1c_network.py --- doc/policy/packages.md | 8 +--- src/policy/packages.h | 2 +- src/test/txpackage_tests.cpp | 14 ------- src/validation.cpp | 48 +++-------------------- test/functional/p2p_1p1c_network.py | 2 +- test/functional/p2p_opportunistic_1p1c.py | 32 ++++++++------- test/functional/rpc_packages.py | 6 ++- 7 files changed, 29 insertions(+), 83 deletions(-) diff --git a/doc/policy/packages.md b/doc/policy/packages.md index 9bd9becfdc4..a2ce1f6fc9e 100644 --- a/doc/policy/packages.md +++ b/doc/policy/packages.md @@ -8,12 +8,6 @@ Graph (a directed edge exists between a transaction that spends the output of an For every transaction `t` in a **topologically sorted** package, if any of its parents are present in the package, they appear somewhere in the list before `t`. -A **child-with-unconfirmed-parents** package is a topologically sorted package that consists of -exactly one child and all of its unconfirmed parents (no other transactions may be present). -The last transaction in the package is the child, and its package can be canonically defined based -on the current state: each of its inputs must be available in the UTXO set as of the current chain -tip or some preceding transaction in the package. - ## Package Mempool Acceptance Rules The following rules are enforced for all packages: @@ -73,7 +67,7 @@ The following rules are enforced for all packages: The following rules are only enforced for packages to be submitted to the mempool (not enforced for test accepts): -* Packages must be child-with-unconfirmed-parents packages. This also means packages must contain at +* Packages must be child-with-parents packages. This also means packages must contain at least 1 transaction. (#31096) - *Rationale*: This allows for fee-bumping by CPFP. Allowing multiple parents makes it possible diff --git a/src/policy/packages.h b/src/policy/packages.h index 30503201226..9e9959c88a4 100644 --- a/src/policy/packages.h +++ b/src/policy/packages.h @@ -26,7 +26,7 @@ static_assert(MAX_PACKAGE_WEIGHT >= MAX_STANDARD_TX_WEIGHT); // If a package is to be evaluated, it must be at least as large as the mempool's ancestor/descendant limits, // otherwise transactions that would be individually accepted may be rejected in a package erroneously. -// Since a submitted package must be child-with-unconfirmed-parents (all of the transactions are an ancestor +// Since a submitted package must be child-with-parents (all of the transactions are an ancestor // of the child), package limits are ultimately bounded by mempool package limits. Ensure that the // defaults reflect this constraint. static_assert(DEFAULT_DESCENDANT_LIMIT >= MAX_PACKAGE_COUNT); diff --git a/src/test/txpackage_tests.cpp b/src/test/txpackage_tests.cpp index 3c36b782604..09e719ff4cc 100644 --- a/src/test/txpackage_tests.cpp +++ b/src/test/txpackage_tests.cpp @@ -441,20 +441,6 @@ BOOST_AUTO_TEST_CASE(package_submission_tests) BOOST_CHECK_EQUAL(result_quit_early.m_state.GetResult(), PackageValidationResult::PCKG_TX); } - // Child with missing parent. - mtx_child.vin.emplace_back(COutPoint(package_unrelated[0]->GetHash(), 0)); - Package package_missing_parent; - package_missing_parent.push_back(tx_parent); - package_missing_parent.push_back(MakeTransactionRef(mtx_child)); - { - const auto result_missing_parent = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool, - package_missing_parent, /*test_accept=*/false, /*client_maxfeerate=*/{}); - BOOST_CHECK(result_missing_parent.m_state.IsInvalid()); - BOOST_CHECK_EQUAL(result_missing_parent.m_state.GetResult(), PackageValidationResult::PCKG_POLICY); - BOOST_CHECK_EQUAL(result_missing_parent.m_state.GetRejectReason(), "package-not-child-with-unconfirmed-parents"); - BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size); - } - // Submit package with parent + child. { const auto submit_parent_child = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool, diff --git a/src/validation.cpp b/src/validation.cpp index 74f4e80485e..dd5274ee928 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -518,7 +518,7 @@ public: }; } - /** Parameters for child-with-unconfirmed-parents package validation. */ + /** Parameters for child-with-parents package validation. */ static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time, std::vector& coins_to_uncache, const std::optional& client_maxfeerate) { return ATMPArgs{/* m_chainparams */ chainparams, @@ -1692,7 +1692,7 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, // There are two topologies we are able to handle through this function: // (1) A single transaction - // (2) A child-with-unconfirmed-parents package. + // (2) A child-with-parents package. // Check that the package is well-formed. If it isn't, we won't try to validate any of the // transactions and thus won't return any MempoolAcceptResults, just a package-wide error. @@ -1701,49 +1701,11 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, return PackageMempoolAcceptResult(package_state_quit_early, {}); } - if (package.size() > 1) { + if (package.size() > 1 && !IsChildWithParents(package)) { // All transactions in the package must be a parent of the last transaction. This is just an // opportunity for us to fail fast on a context-free check without taking the mempool lock. - if (!IsChildWithParents(package)) { - package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents"); - return PackageMempoolAcceptResult(package_state_quit_early, {}); - } - - // IsChildWithParents() guarantees the package is > 1 transactions. - assert(package.size() > 1); - // The package must be 1 child with all of its unconfirmed parents. The package is expected to - // be sorted, so the last transaction is the child. - const auto& child = package.back(); - std::unordered_set unconfirmed_parent_txids; - std::transform(package.cbegin(), package.cend() - 1, - std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()), - [](const auto& tx) { return tx->GetHash(); }); - - // All child inputs must refer to a preceding package transaction or a confirmed UTXO. The only - // way to verify this is to look up the child's inputs in our current coins view (not including - // mempool), and enforce that all parents not present in the package be available at chain tip. - // Since this check can bring new coins into the coins cache, keep track of these coins and - // uncache them if we don't end up submitting this package to the mempool. - const CCoinsViewCache& coins_tip_cache = m_active_chainstate.CoinsTip(); - for (const auto& input : child->vin) { - if (!coins_tip_cache.HaveCoinInCache(input.prevout)) { - args.m_coins_to_uncache.push_back(input.prevout); - } - } - // Using the MemPoolAccept m_view cache allows us to look up these same coins faster later. - // This should be connecting directly to CoinsTip, not to m_viewmempool, because we specifically - // require inputs to be confirmed if they aren't in the package. - m_view.SetBackend(m_active_chainstate.CoinsTip()); - const auto package_or_confirmed = [this, &unconfirmed_parent_txids](const auto& input) { - return unconfirmed_parent_txids.count(input.prevout.hash) > 0 || m_view.HaveCoin(input.prevout); - }; - if (!std::all_of(child->vin.cbegin(), child->vin.cend(), package_or_confirmed)) { - package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-unconfirmed-parents"); - return PackageMempoolAcceptResult(package_state_quit_early, {}); - } - // Protect against bugs where we pull more inputs from disk that miss being added to - // coins_to_uncache. The backend will be connected again when needed in PreChecks. - m_view.SetBackend(m_dummy); + package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents"); + return PackageMempoolAcceptResult(package_state_quit_early, {}); } LOCK(m_pool.cs); diff --git a/test/functional/p2p_1p1c_network.py b/test/functional/p2p_1p1c_network.py index cdc4e1691d6..6a7774ded35 100755 --- a/test/functional/p2p_1p1c_network.py +++ b/test/functional/p2p_1p1c_network.py @@ -103,7 +103,7 @@ class PackageRelayTest(BitcoinTestFramework): package_hex_2, parent_2, child_2 = self.create_basic_1p1c(self.wallet_nonsegwit) # 3: 2-parent-1-child package. Both parents are above mempool min feerate. No package submission happens. - # We require packages to be child-with-unconfirmed-parents and only allow 1-parent-1-child packages. + # We require packages to be child-with-parents and only allow 1-parent-1-child packages. package_hex_3, parent_31, _parent_32, child_3 = self.create_package_2p1c(self.wallet) # 4: parent + child package where the child spends 2 different outputs from the parent. diff --git a/test/functional/p2p_opportunistic_1p1c.py b/test/functional/p2p_opportunistic_1p1c.py index 4477046c8d6..f439783fc71 100755 --- a/test/functional/p2p_opportunistic_1p1c.py +++ b/test/functional/p2p_opportunistic_1p1c.py @@ -25,7 +25,6 @@ from test_framework.p2p import ( ) from test_framework.test_framework import BitcoinTestFramework from test_framework.util import ( - assert_equal, assert_greater_than, ) from test_framework.wallet import ( @@ -64,14 +63,14 @@ class PackageRelayTest(BitcoinTestFramework): ]] self.supports_cli = False - def create_tx_below_mempoolminfee(self, wallet): + def create_tx_below_mempoolminfee(self, wallet, utxo_to_spend=None): """Create a 1-input 1sat/vB transaction using a confirmed UTXO. Decrement and use self.sequence so that subsequent calls to this function result in unique transactions.""" self.sequence -= 1 assert_greater_than(self.nodes[0].getmempoolinfo()["mempoolminfee"], FEERATE_1SAT_VB) - return wallet.create_self_transfer(fee_rate=FEERATE_1SAT_VB, sequence=self.sequence, confirmed_only=True) + return wallet.create_self_transfer(fee_rate=FEERATE_1SAT_VB, sequence=self.sequence, utxo_to_spend=utxo_to_spend, confirmed_only=True) @cleanup def test_basic_child_then_parent(self): @@ -340,11 +339,14 @@ class PackageRelayTest(BitcoinTestFramework): @cleanup def test_other_parent_in_mempool(self): - self.log.info("Check opportunistic 1p1c fails if child already has another parent in mempool") + self.log.info("Check opportunistic 1p1c works even if child already has another parent in mempool") node = self.nodes[0] + # Grandparent will enter mempool by itself + grandparent_high = self.wallet.create_self_transfer(fee_rate=FEERATE_1SAT_VB*10, confirmed_only=True) + # This parent needs CPFP - parent_low = self.create_tx_below_mempoolminfee(self.wallet) + parent_low = self.create_tx_below_mempoolminfee(self.wallet, utxo_to_spend=grandparent_high["new_utxo"]) # This parent does not need CPFP and can be submitted alone ahead of time parent_high = self.wallet.create_self_transfer(fee_rate=FEERATE_1SAT_VB*10, confirmed_only=True) child = self.wallet.create_self_transfer_multi( @@ -354,27 +356,27 @@ class PackageRelayTest(BitcoinTestFramework): peer_sender = node.add_outbound_p2p_connection(P2PInterface(), p2p_idx=1, connection_type="outbound-full-relay") - # 1. Send first parent which will be accepted. + # 1. Send grandparent which is accepted + peer_sender.send_and_ping(msg_tx(grandparent_high["tx"])) + assert grandparent_high["txid"] in node.getrawmempool() + + # 2. Send first parent which is accepted. peer_sender.send_and_ping(msg_tx(parent_high["tx"])) assert parent_high["txid"] in node.getrawmempool() - # 2. Send child. + # 3. Send child which is handled as an orphan. peer_sender.send_and_ping(msg_tx(child["tx"])) - # 3. Node requests parent_low. However, 1p1c fails because package-not-child-with-unconfirmed-parents + # 4. Node requests parent_low. parent_low_txid_int = int(parent_low["txid"], 16) peer_sender.wait_for_getdata([parent_low_txid_int]) peer_sender.send_and_ping(msg_tx(parent_low["tx"])) node_mempool = node.getrawmempool() + assert grandparent_high["txid"] in node_mempool assert parent_high["txid"] in node_mempool - assert parent_low["txid"] not in node_mempool - assert child["txid"] not in node_mempool - - # Same error if submitted through submitpackage without parent_high - package_hex_missing_parent = [parent_low["hex"], child["hex"]] - result_missing_parent = node.submitpackage(package_hex_missing_parent) - assert_equal(result_missing_parent["package_msg"], "package-not-child-with-unconfirmed-parents") + assert parent_low["txid"] in node_mempool + assert child["txid"] in node_mempool def run_test(self): node = self.nodes[0] diff --git a/test/functional/rpc_packages.py b/test/functional/rpc_packages.py index f5d42d0c343..586d3d5b510 100755 --- a/test/functional/rpc_packages.py +++ b/test/functional/rpc_packages.py @@ -267,9 +267,11 @@ class RPCPackagesTest(BitcoinTestFramework): assert_equal(submitres, {'package_msg': 'conflict-in-package', 'tx-results': {}, 'replaced-transactions': []}) assert tx_child["txid"] not in node.getrawmempool() - # ... and without the in-mempool ancestor tx1 included in the call + # without the in-mempool ancestor tx1 included in the call, tx2 can be submitted, but + # tx_child is missing an input. submitres = node.submitpackage([tx2["hex"], tx_child["hex"]]) - assert_equal(submitres, {'package_msg': 'package-not-child-with-unconfirmed-parents', 'tx-results': {}, 'replaced-transactions': []}) + assert_equal(submitres["tx-results"][tx_child["wtxid"]], {"txid": tx_child["txid"], "error": "bad-txns-inputs-missingorspent"}) + assert tx2["txid"] in node.getrawmempool() # Regardless of error type, the child can never enter the mempool assert tx_child["txid"] not in node.getrawmempool() From b14e1a86886dd48d6206f95757bbbe26609892e4 Mon Sep 17 00:00:00 2001 From: glozow Date: Tue, 10 Dec 2024 07:35:11 -0500 Subject: [PATCH 2/2] [unit test] package submission 2p1c with 1 parent missing --- src/test/txpackage_tests.cpp | 57 ++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/src/test/txpackage_tests.cpp b/src/test/txpackage_tests.cpp index 09e719ff4cc..173a4ea4c52 100644 --- a/src/test/txpackage_tests.cpp +++ b/src/test/txpackage_tests.cpp @@ -355,6 +355,9 @@ BOOST_AUTO_TEST_CASE(noncontextual_package_tests) BOOST_AUTO_TEST_CASE(package_submission_tests) { + // Mine blocks to mature coinbases. + mineBlocks(3); + MockMempoolMinFee(CFeeRate(5000)); LOCK(cs_main); unsigned int expected_pool_size = m_node.mempool->size(); CKey parent_key = GenerateRandomKey(); @@ -478,6 +481,60 @@ BOOST_AUTO_TEST_CASE(package_submission_tests) BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size); } + + // In-mempool parent and child with missing parent. + { + auto tx_parent_1 = MakeTransactionRef(CreateValidMempoolTransaction(/*input_transaction=*/m_coinbase_txns[1], /*input_vout=*/0, + /*input_height=*/0, /*input_signing_key=*/coinbaseKey, + /*output_destination=*/parent_locking_script, + /*output_amount=*/CAmount(50 * COIN - low_fee_amt), /*submit=*/false)); + auto tx_parent_2 = MakeTransactionRef(CreateValidMempoolTransaction(/*input_transaction=*/m_coinbase_txns[2], /*input_vout=*/0, + /*input_height=*/0, /*input_signing_key=*/coinbaseKey, + /*output_destination=*/parent_locking_script, + /*output_amount=*/CAmount(50 * COIN - 800), /*submit=*/false)); + + auto tx_child_missing_parent = MakeTransactionRef(CreateValidMempoolTransaction({tx_parent_1, tx_parent_2}, + {{tx_parent_1->GetHash(), 0}, {tx_parent_2->GetHash(), 0}}, + /*input_height=*/0, {parent_key}, + {{49 * COIN, child_locking_script}}, /*submit=*/false)); + + Package package_missing_parent{tx_parent_1, tx_child_missing_parent}; + + const auto result_missing_parent = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool, + package_missing_parent, /*test_accept=*/false, /*client_maxfeerate=*/{}); + if (auto err_missing_parent{CheckPackageMempoolAcceptResult(package_missing_parent, result_missing_parent, /*expect_valid=*/false, m_node.mempool.get())}) { + BOOST_ERROR(err_missing_parent.value()); + } else { + auto it_parent = result_missing_parent.m_tx_results.find(tx_parent_1->GetWitnessHash()); + auto it_child = result_missing_parent.m_tx_results.find(tx_child_missing_parent->GetWitnessHash()); + + BOOST_CHECK_EQUAL(result_missing_parent.m_state.GetResult(), PackageValidationResult::PCKG_TX); + BOOST_CHECK_EQUAL(result_missing_parent.m_state.GetRejectReason(), "transaction failed"); + + BOOST_CHECK_EQUAL(it_parent->second.m_state.GetResult(), TxValidationResult::TX_RECONSIDERABLE); + BOOST_CHECK_EQUAL(it_child->second.m_state.GetResult(), TxValidationResult::TX_MISSING_INPUTS); + BOOST_CHECK_EQUAL(it_child->second.m_state.GetRejectReason(), "bad-txns-inputs-missingorspent"); + BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size); + } + + // Submit parent2 ahead of time, should become ok. + Package package_just_parent2{tx_parent_2}; + expected_pool_size += 1; + const auto result_just_parent2 = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool, + package_just_parent2, /*test_accept=*/false, /*client_maxfeerate=*/{}); + if (auto err_parent2{CheckPackageMempoolAcceptResult(package_just_parent2, result_just_parent2, /*expect_valid=*/true, m_node.mempool.get())}) { + BOOST_ERROR(err_parent2.value()); + } + BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size); + + const auto result_parent_already_in = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool, + package_missing_parent, /*test_accept=*/false, /*client_maxfeerate=*/{}); + expected_pool_size += 2; + if (auto err_parent_already_in{CheckPackageMempoolAcceptResult(package_missing_parent, result_parent_already_in, /*expect_valid=*/true, m_node.mempool.get())}) { + BOOST_ERROR(err_parent_already_in.value()); + } + BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size); + } } // Tests for packages containing a single transaction