Merge bitcoin/bitcoin#22674: validation: mempool validation and submission for packages of 1 child + parents

046e8ff264be6b888c0f9a9d822e32aa74e19b78 [unit test] package submission (glozow)
e12fafda2dfbbdf63f125e5af797ecfaa6488f66 [validation] de-duplicate package transactions already in mempool (glozow)
8310d942e046c5a9b6bd90afdcd3af68dd91e081 [packages] add sanity checks for package vs mempool limits (glozow)
be3ff151a1f9665720cdf70d072b098a2f9726a9 [validation] full package accept + mempool submission (glozow)
144a29099a865ac1dc3e5291d9529fbcca9c83a4 [policy] require submitted packages to be child-with-unconfirmed-parents (glozow)
d59ddc5c3d1c035474d7bc9fa9f8a0eeb1c8498c [packages/doc] define and document package rules (glozow)
ba26169f6035c238378a3c9647213328a006fa23 [unit test] context-free package checks (glozow)
9b2fdca7f03911ac40fe0f8a0b5da534bee4554b [packages] add static IsChildWithParents function (glozow)

Pull request description:

  This is 1 chunk of [Package Mempool Accept](https://gist.github.com/glozow/dc4e9d5c5b14ade7cdfac40f43adb18a); it restricts packages to 1 child with its parents, doesn't allow conflicts, and doesn't have CPFP (yet).  Future PRs (see #22290) will add RBF and CPFP within packages.

ACKs for top commit:
  laanwj:
    Code review ACK 046e8ff264be6b888c0f9a9d822e32aa74e19b78

Tree-SHA512: 37dbba37d527712f8efef71ee05c90a8308992615af35f5e0cfeafc60d859cc792737d125aac526e37742fe7683ac8c155ac24af562426213904333c01260c95

1 files changed, 213 insertions, 0 deletions

diff --git a/src/test/txpackage_tests.cpp b/src/test/txpackage_tests.cpp
index 2193e21780..6f78b43826 100644
--- a/src/test/txpackage_tests.cpp
+++ b/src/test/txpackage_tests.cpp
@@ -114,4 +114,217 @@ BOOST_FIXTURE_TEST_CASE(package_validation_tests, TestChain100Setup)
     // Check that mempool size hasn't changed.
     BOOST_CHECK_EQUAL(m_node.mempool->size(), initialPoolSize);
 }
+
+BOOST_FIXTURE_TEST_CASE(noncontextual_package_tests, TestChain100Setup)
+{
+    // The signatures won't be verified so we can just use a placeholder
+    CKey placeholder_key;
+    placeholder_key.MakeNewKey(true);
+    CScript spk = GetScriptForDestination(PKHash(placeholder_key.GetPubKey()));
+    CKey placeholder_key_2;
+    placeholder_key_2.MakeNewKey(true);
+    CScript spk2 = GetScriptForDestination(PKHash(placeholder_key_2.GetPubKey()));
+
+    // Parent and Child Package
+    {
+        auto mtx_parent = CreateValidMempoolTransaction(m_coinbase_txns[0], 0, 0, coinbaseKey, spk,
+                                                        CAmount(49 * COIN), /* submit */ false);
+        CTransactionRef tx_parent = MakeTransactionRef(mtx_parent);
+
+        auto mtx_child = CreateValidMempoolTransaction(tx_parent, 0, 101, placeholder_key, spk2,
+                                                       CAmount(48 * COIN), /* submit */ false);
+        CTransactionRef tx_child = MakeTransactionRef(mtx_child);
+
+        PackageValidationState state;
+        BOOST_CHECK(CheckPackage({tx_parent, tx_child}, state));
+        BOOST_CHECK(!CheckPackage({tx_child, tx_parent}, state));
+        BOOST_CHECK_EQUAL(state.GetResult(), PackageValidationResult::PCKG_POLICY);
+        BOOST_CHECK_EQUAL(state.GetRejectReason(), "package-not-sorted");
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_child}));
+    }
+
+    // 24 Parents and 1 Child
+    {
+        Package package;
+        CMutableTransaction child;
+        for (int i{0}; i < 24; ++i) {
+            auto parent = MakeTransactionRef(CreateValidMempoolTransaction(m_coinbase_txns[i + 1],
+                                             0, 0, coinbaseKey, spk, CAmount(48 * COIN), false));
+            package.emplace_back(parent);
+            child.vin.push_back(CTxIn(COutPoint(parent->GetHash(), 0)));
+        }
+        child.vout.push_back(CTxOut(47 * COIN, spk2));
+
+        // The child must be in the package.
+        BOOST_CHECK(!IsChildWithParents(package));
+
+        // The parents can be in any order.
+        FastRandomContext rng;
+        Shuffle(package.begin(), package.end(), rng);
+        package.push_back(MakeTransactionRef(child));
+
+        PackageValidationState state;
+        BOOST_CHECK(CheckPackage(package, state));
+        BOOST_CHECK(IsChildWithParents(package));
+
+        package.erase(package.begin());
+        BOOST_CHECK(IsChildWithParents(package));
+
+        // The package cannot have unrelated transactions.
+        package.insert(package.begin(), m_coinbase_txns[0]);
+        BOOST_CHECK(!IsChildWithParents(package));
+    }
+
+    // 2 Parents and 1 Child where one parent depends on the other.
+    {
+        CMutableTransaction mtx_parent;
+        mtx_parent.vin.push_back(CTxIn(COutPoint(m_coinbase_txns[0]->GetHash(), 0)));
+        mtx_parent.vout.push_back(CTxOut(20 * COIN, spk));
+        mtx_parent.vout.push_back(CTxOut(20 * COIN, spk2));
+        CTransactionRef tx_parent = MakeTransactionRef(mtx_parent);
+
+        CMutableTransaction mtx_parent_also_child;
+        mtx_parent_also_child.vin.push_back(CTxIn(COutPoint(tx_parent->GetHash(), 0)));
+        mtx_parent_also_child.vout.push_back(CTxOut(20 * COIN, spk));
+        CTransactionRef tx_parent_also_child = MakeTransactionRef(mtx_parent_also_child);
+
+        CMutableTransaction mtx_child;
+        mtx_child.vin.push_back(CTxIn(COutPoint(tx_parent->GetHash(), 1)));
+        mtx_child.vin.push_back(CTxIn(COutPoint(tx_parent_also_child->GetHash(), 0)));
+        mtx_child.vout.push_back(CTxOut(39 * COIN, spk));
+        CTransactionRef tx_child = MakeTransactionRef(mtx_child);
+
+        PackageValidationState state;
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_parent_also_child}));
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_child}));
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_parent_also_child, tx_child}));
+        // IsChildWithParents does not detect unsorted parents.
+        BOOST_CHECK(IsChildWithParents({tx_parent_also_child, tx_parent, tx_child}));
+        BOOST_CHECK(CheckPackage({tx_parent, tx_parent_also_child, tx_child}, state));
+        BOOST_CHECK(!CheckPackage({tx_parent_also_child, tx_parent, tx_child}, state));
+        BOOST_CHECK_EQUAL(state.GetResult(), PackageValidationResult::PCKG_POLICY);
+        BOOST_CHECK_EQUAL(state.GetRejectReason(), "package-not-sorted");
+    }
+}
+
+BOOST_FIXTURE_TEST_CASE(package_submission_tests, TestChain100Setup)
+{
+    LOCK(cs_main);
+    unsigned int expected_pool_size = m_node.mempool->size();
+    CKey parent_key;
+    parent_key.MakeNewKey(true);
+    CScript parent_locking_script = GetScriptForDestination(PKHash(parent_key.GetPubKey()));
+
+    // Unrelated transactions are not allowed in package submission.
+    Package package_unrelated;
+    for (size_t i{0}; i < 10; ++i) {
+        auto mtx = CreateValidMempoolTransaction(/* input_transaction */ m_coinbase_txns[i + 25], /* vout */ 0,
+                                                 /* input_height */ 0, /* input_signing_key */ coinbaseKey,
+                                                 /* output_destination */ parent_locking_script,
+                                                 /* output_amount */ CAmount(49 * COIN), /* submit */ false);
+        package_unrelated.emplace_back(MakeTransactionRef(mtx));
+    }
+    auto result_unrelated_submit = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool,
+                                                     package_unrelated, /* test_accept */ false);
+    BOOST_CHECK(result_unrelated_submit.m_state.IsInvalid());
+    BOOST_CHECK_EQUAL(result_unrelated_submit.m_state.GetResult(), PackageValidationResult::PCKG_POLICY);
+    BOOST_CHECK_EQUAL(result_unrelated_submit.m_state.GetRejectReason(), "package-not-child-with-parents");
+    BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size);
+
+    // Parent and Child (and Grandchild) Package
+    Package package_parent_child;
+    Package package_3gen;
+    auto mtx_parent = CreateValidMempoolTransaction(/* input_transaction */ m_coinbase_txns[0], /* vout */ 0,
+                                                    /* input_height */ 0, /* input_signing_key */ coinbaseKey,
+                                                    /* output_destination */ parent_locking_script,
+                                                    /* output_amount */ CAmount(49 * COIN), /* submit */ false);
+    CTransactionRef tx_parent = MakeTransactionRef(mtx_parent);
+    package_parent_child.push_back(tx_parent);
+    package_3gen.push_back(tx_parent);
+
+    CKey child_key;
+    child_key.MakeNewKey(true);
+    CScript child_locking_script = GetScriptForDestination(PKHash(child_key.GetPubKey()));
+    auto mtx_child = CreateValidMempoolTransaction(/* input_transaction */ tx_parent, /* vout */ 0,
+                                                   /* input_height */ 101, /* input_signing_key */ parent_key,
+                                                   /* output_destination */ child_locking_script,
+                                                   /* output_amount */ CAmount(48 * COIN), /* submit */ false);
+    CTransactionRef tx_child = MakeTransactionRef(mtx_child);
+    package_parent_child.push_back(tx_child);
+    package_3gen.push_back(tx_child);
+
+    CKey grandchild_key;
+    grandchild_key.MakeNewKey(true);
+    CScript grandchild_locking_script = GetScriptForDestination(PKHash(grandchild_key.GetPubKey()));
+    auto mtx_grandchild = CreateValidMempoolTransaction(/* input_transaction */ tx_child, /* vout */ 0,
+                                                       /* input_height */ 101, /* input_signing_key */ child_key,
+                                                       /* output_destination */ grandchild_locking_script,
+                                                       /* output_amount */ CAmount(47 * COIN), /* submit */ false);
+    CTransactionRef tx_grandchild = MakeTransactionRef(mtx_grandchild);
+    package_3gen.push_back(tx_grandchild);
+
+    // 3 Generations is not allowed.
+    {
+        auto result_3gen_submit = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool,
+                                                    package_3gen, /* test_accept */ false);
+        BOOST_CHECK(result_3gen_submit.m_state.IsInvalid());
+        BOOST_CHECK_EQUAL(result_3gen_submit.m_state.GetResult(), PackageValidationResult::PCKG_POLICY);
+        BOOST_CHECK_EQUAL(result_3gen_submit.m_state.GetRejectReason(), "package-not-child-with-parents");
+        BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size);
+    }
+
+    // Child with missing parent.
+    mtx_child.vin.push_back(CTxIn(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);
+        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,
+                                                           package_parent_child, /* test_accept */ false);
+        expected_pool_size += 2;
+        BOOST_CHECK_MESSAGE(submit_parent_child.m_state.IsValid(),
+                            "Package validation unexpectedly failed: " << submit_parent_child.m_state.GetRejectReason());
+        auto it_parent = submit_parent_child.m_tx_results.find(tx_parent->GetWitnessHash());
+        auto it_child = submit_parent_child.m_tx_results.find(tx_child->GetWitnessHash());
+        BOOST_CHECK(it_parent != submit_parent_child.m_tx_results.end());
+        BOOST_CHECK(it_parent->second.m_state.IsValid());
+        BOOST_CHECK(it_child != submit_parent_child.m_tx_results.end());
+        BOOST_CHECK(it_child->second.m_state.IsValid());
+
+        BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size);
+        BOOST_CHECK(m_node.mempool->exists(GenTxid::Txid(tx_parent->GetHash())));
+        BOOST_CHECK(m_node.mempool->exists(GenTxid::Txid(tx_child->GetHash())));
+    }
+
+    // Already-in-mempool transactions should be detected and de-duplicated.
+    {
+        const auto submit_deduped = ProcessNewPackage(m_node.chainman->ActiveChainstate(), *m_node.mempool,
+                                                      package_parent_child, /* test_accept */ false);
+        BOOST_CHECK_MESSAGE(submit_deduped.m_state.IsValid(),
+                            "Package validation unexpectedly failed: " << submit_deduped.m_state.GetRejectReason());
+        auto it_parent_deduped = submit_deduped.m_tx_results.find(tx_parent->GetWitnessHash());
+        auto it_child_deduped = submit_deduped.m_tx_results.find(tx_child->GetWitnessHash());
+        BOOST_CHECK(it_parent_deduped != submit_deduped.m_tx_results.end());
+        BOOST_CHECK(it_parent_deduped->second.m_state.IsValid());
+        BOOST_CHECK(it_parent_deduped->second.m_result_type == MempoolAcceptResult::ResultType::MEMPOOL_ENTRY);
+        BOOST_CHECK(it_child_deduped != submit_deduped.m_tx_results.end());
+        BOOST_CHECK(it_child_deduped->second.m_state.IsValid());
+        BOOST_CHECK(it_child_deduped->second.m_result_type == MempoolAcceptResult::ResultType::MEMPOOL_ENTRY);
+
+        BOOST_CHECK_EQUAL(m_node.mempool->size(), expected_pool_size);
+        BOOST_CHECK(m_node.mempool->exists(GenTxid::Txid(tx_parent->GetHash())));
+        BOOST_CHECK(m_node.mempool->exists(GenTxid::Txid(tx_child->GetHash())));
+    }
+}
 BOOST_AUTO_TEST_SUITE_END()