diff options
Diffstat (limited to 'src/policy/truc_policy.h')
| -rw-r--r-- | src/policy/truc_policy.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/policy/truc_policy.h b/src/policy/truc_policy.h new file mode 100644 index 0000000000..dbc77696c6 --- /dev/null +++ b/src/policy/truc_policy.h @@ -0,0 +1,94 @@ +// Copyright (c) 2022 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_POLICY_TRUC_POLICY_H +#define BITCOIN_POLICY_TRUC_POLICY_H + +#include <consensus/amount.h> +#include <policy/packages.h> +#include <policy/policy.h> +#include <primitives/transaction.h> +#include <txmempool.h> +#include <util/result.h> + +#include <set> +#include <string> + +// This module enforces rules for BIP 431 TRUC transactions which help make +// RBF abilities more robust. A transaction with version=3 is treated as TRUC. +static constexpr decltype(CTransaction::version) TRUC_VERSION{3}; + +// TRUC only allows 1 parent and 1 child when unconfirmed. This translates to a descendant set size +// of 2 and ancestor set size of 2. +/** Maximum number of transactions including an unconfirmed tx and its descendants. */ +static constexpr unsigned int TRUC_DESCENDANT_LIMIT{2}; +/** Maximum number of transactions including a TRUC tx and all its mempool ancestors. */ +static constexpr unsigned int TRUC_ANCESTOR_LIMIT{2}; + +/** Maximum sigop-adjusted virtual size of all v3 transactions. */ +static constexpr int64_t TRUC_MAX_VSIZE{10000}; +/** Maximum sigop-adjusted virtual size of a tx which spends from an unconfirmed TRUC transaction. */ +static constexpr int64_t TRUC_CHILD_MAX_VSIZE{1000}; +// These limits are within the default ancestor/descendant limits. +static_assert(TRUC_MAX_VSIZE + TRUC_CHILD_MAX_VSIZE <= DEFAULT_ANCESTOR_SIZE_LIMIT_KVB * 1000); +static_assert(TRUC_MAX_VSIZE + TRUC_CHILD_MAX_VSIZE <= DEFAULT_DESCENDANT_SIZE_LIMIT_KVB * 1000); + +/** Must be called for every transaction, even if not TRUC. Not strictly necessary for transactions + * accepted through AcceptMultipleTransactions. + * + * Checks the following rules: + * 1. A TRUC tx must only have TRUC unconfirmed ancestors. + * 2. A non-TRUC tx must only have non-TRUC unconfirmed ancestors. + * 3. A TRUC's ancestor set, including itself, must be within TRUC_ANCESTOR_LIMIT. + * 4. A TRUC's descendant set, including itself, must be within TRUC_DESCENDANT_LIMIT. + * 5. If a TRUC tx has any unconfirmed ancestors, the tx's sigop-adjusted vsize must be within + * TRUC_CHILD_MAX_VSIZE. + * 6. A TRUC tx must be within TRUC_MAX_VSIZE. + * + * + * @param[in] mempool_ancestors The in-mempool ancestors of ptx. + * @param[in] direct_conflicts In-mempool transactions this tx conflicts with. These conflicts + * are used to more accurately calculate the resulting descendant + * count of in-mempool ancestors. + * @param[in] vsize The sigop-adjusted virtual size of ptx. + * + * @returns 3 possibilities: + * - std::nullopt if all TRUC checks were applied successfully + * - debug string + pointer to a mempool sibling if this transaction would be the second child in a + * 1-parent-1-child cluster; the caller may consider evicting the specified sibling or return an + * error with the debug string. + * - debug string + nullptr if this transaction violates some TRUC rule and sibling eviction is not + * applicable. + */ +std::optional<std::pair<std::string, CTransactionRef>> SingleTRUCChecks(const CTransactionRef& ptx, + const CTxMemPool::setEntries& mempool_ancestors, + const std::set<Txid>& direct_conflicts, + int64_t vsize); + +/** Must be called for every transaction that is submitted within a package, even if not TRUC. + * + * For each transaction in a package: + * If it's not a TRUC transaction, verify it has no direct TRUC parents in the mempool or the package. + + * If it is a TRUC transaction, verify that any direct parents in the mempool or the package are TRUC. + * If such a parent exists, verify that parent has no other children in the package or the mempool, + * and that the transaction itself has no children in the package. + * + * If any TRUC violations in the package exist, this test will fail for one of them: + * - if a TRUC transaction T has a parent in the mempool and a child in the package, then PTRUCC(T) will fail + * - if a TRUC transaction T has a parent in the package and a child in the package, then PTRUCC(T) will fail + * - if a TRUC transaction T and a TRUC (sibling) transaction U have some parent in the mempool, + * then PTRUCC(T) and PTRUCC(U) will fail + * - if a TRUC transaction T and a TRUC (sibling) transaction U have some parent in the package, + * then PTRUCC(T) and PTRUCC(U) will fail + * - if a TRUC transaction T has a parent P and a grandparent G in the package, then + * PTRUCC(P) will fail (though PTRUCC(G) and PTRUCC(T) might succeed). + * + * @returns debug string if an error occurs, std::nullopt otherwise. + * */ +std::optional<std::string> PackageTRUCChecks(const CTransactionRef& ptx, int64_t vsize, + const Package& package, + const CTxMemPool::setEntries& mempool_ancestors); + +#endif // BITCOIN_POLICY_TRUC_POLICY_H |