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Diffstat (limited to 'src/policy/truc_policy.h')
| -rw-r--r-- | src/policy/truc_policy.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/src/policy/truc_policy.h b/src/policy/truc_policy.h new file mode 100644 index 0000000000..f553110df3 --- /dev/null +++ b/src/policy/truc_policy.h @@ -0,0 +1,93 @@ +// 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 (with version=3) which help make +// RBF abilities more robust. +static constexpr decltype(CTransaction::version) TRUC_VERSION{3}; + +// v3 only allows 1 parent and 1 child when unconfirmed. +/** Maximum number of transactions including an unconfirmed tx and its descendants. */ +static constexpr unsigned int V3_DESCENDANT_LIMIT{2}; +/** Maximum number of transactions including a V3 tx and all its mempool ancestors. */ +static constexpr unsigned int V3_ANCESTOR_LIMIT{2}; + +/** Maximum sigop-adjusted virtual size of all v3 transactions. */ +static constexpr int64_t V3_MAX_VSIZE{10000}; +/** Maximum sigop-adjusted virtual size of a tx which spends from an unconfirmed v3 transaction. */ +static constexpr int64_t V3_CHILD_MAX_VSIZE{1000}; +// These limits are within the default ancestor/descendant limits. +static_assert(V3_MAX_VSIZE + V3_CHILD_MAX_VSIZE <= DEFAULT_ANCESTOR_SIZE_LIMIT_KVB * 1000); +static_assert(V3_MAX_VSIZE + V3_CHILD_MAX_VSIZE <= DEFAULT_DESCENDANT_SIZE_LIMIT_KVB * 1000); + +/** Must be called for every transaction, even if not v3. Not strictly necessary for transactions + * accepted through AcceptMultipleTransactions. + * + * Checks the following rules: + * 1. A v3 tx must only have v3 unconfirmed ancestors. + * 2. A non-v3 tx must only have non-v3 unconfirmed ancestors. + * 3. A v3's ancestor set, including itself, must be within V3_ANCESTOR_LIMIT. + * 4. A v3's descendant set, including itself, must be within V3_DESCENDANT_LIMIT. + * 5. If a v3 tx has any unconfirmed ancestors, the tx's sigop-adjusted vsize must be within + * V3_CHILD_MAX_VSIZE. + * 6. A v3 tx must be within V3_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 v3 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 v3 rule and sibling eviction is not + * applicable. + */ +std::optional<std::pair<std::string, CTransactionRef>> SingleV3Checks(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 v3. + * + * For each transaction in a package: + * If it's not a v3 transaction, verify it has no direct v3 parents in the mempool or the package. + + * If it is a v3 transaction, verify that any direct parents in the mempool or the package are v3. + * 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 v3 violations in the package exist, this test will fail for one of them: + * - if a v3 transaction T has a parent in the mempool and a child in the package, then PV3C(T) will fail + * - if a v3 transaction T has a parent in the package and a child in the package, then PV3C(T) will fail + * - if a v3 transaction T and a v3 (sibling) transaction U have some parent in the mempool, + * then PV3C(T) and PV3C(U) will fail + * - if a v3 transaction T and a v3 (sibling) transaction U have some parent in the package, + * then PV3C(T) and PV3C(U) will fail + * - if a v3 transaction T has a parent P and a grandparent G in the package, then + * PV3C(P) will fail (though PV3C(G) and PV3C(T) might succeed). + * + * @returns debug string if an error occurs, std::nullopt otherwise. + * */ +std::optional<std::string> PackageV3Checks(const CTransactionRef& ptx, int64_t vsize, + const Package& package, + const CTxMemPool::setEntries& mempool_ancestors); + +#endif // BITCOIN_POLICY_TRUC_POLICY_H |