From 2b777485fa1ee34a3d347acde9fcaaf5fbbf8e53 Mon Sep 17 00:00:00 2001 From: Antoine Poinsot Date: Mon, 5 Apr 2021 14:58:36 +0200 Subject: [PATCH] policy: introduce p2p constants from the reference implementation This introduces some constants defined by Bitcoin Core which as a consequence define some network rules in a new 'policy' module. Only some were picked, which are very unlikely to change. Nonetheless a Warning has been put in the module documentation. Script-level constants are left into rust-miniscript where they are already defined (src/miniscript/limits.rs). --- src/blockdata/constants.rs | 3 ++- src/lib.rs | 1 + src/policy/mod.rs | 54 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 57 insertions(+), 1 deletion(-) create mode 100644 src/policy/mod.rs diff --git a/src/blockdata/constants.rs b/src/blockdata/constants.rs index a7108d53..8458b95b 100644 --- a/src/blockdata/constants.rs +++ b/src/blockdata/constants.rs @@ -46,7 +46,8 @@ pub const MAX_BLOCK_WEIGHT: u32 = 4_000_000; pub const MIN_TRANSACTION_WEIGHT: u32 = 4 * 60; /// The factor that non-witness serialization data is multiplied by during weight calculation pub const WITNESS_SCALE_FACTOR: usize = 4; - +/// The maximum allowed number of signature check operations in a block +pub const MAX_BLOCK_SIGOPS_COST: i64 = 80_000; /// In Bitcoind this is insanely described as ~((u256)0 >> 32) pub fn max_target(_: Network) -> Uint256 { diff --git a/src/lib.rs b/src/lib.rs index 26bf991e..71395090 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -68,6 +68,7 @@ pub mod blockdata; pub mod util; pub mod consensus; pub mod hash_types; +pub mod policy; pub use hash_types::*; pub use blockdata::block::Block; diff --git a/src/policy/mod.rs b/src/policy/mod.rs new file mode 100644 index 00000000..e6cdc26e --- /dev/null +++ b/src/policy/mod.rs @@ -0,0 +1,54 @@ +// Rust Bitcoin Library +// Written in 2014 by +// Andrew Poelstra +// +// To the extent possible under law, the author(s) have dedicated all +// copyright and related and neighboring rights to this software to +// the public domain worldwide. This software is distributed without +// any warranty. +// +// You should have received a copy of the CC0 Public Domain Dedication +// along with this software. +// If not, see . +// + +//! Policy +//! +//! This module exposes some constants and functions used in the reference implementation and which +//! as a consequence defines some network rules. +//! +//! # *Warning* +//! While the constants present in this module are very unlikely to change, they do not define +//! Bitcoin. As such they must not be relied upon as if they were consensus rules. +//! +//! These values were taken from bitcoind v0.21.1 (194b9b8792d9b0798fdb570b79fa51f1d1f5ebaf). + +use super::blockdata::constants::MAX_BLOCK_SIGOPS_COST; + +/// Maximum weight of a transaction for it to be relayed by most nodes on the network +pub const MAX_STANDARD_TX_WEIGHT: u32 = 400_000; + +/// Minimum non-witness size for a standard transaction (1 segwit input + 1 P2WPKH output = 82 bytes) +pub const MIN_STANDARD_TX_NONWITNESS_SIZE: u32 = 82; + +/// Maximum number of sigops in a standard tx. +pub const MAX_STANDARD_TX_SIGOPS_COST: u32 = MAX_BLOCK_SIGOPS_COST as u32 / 5; + +/// The minimum incremental *feerate* (despite the name), in sats per virtual kilobyte for RBF. +pub const DEFAULT_INCREMENTAL_RELAY_FEE: u32 = 1_000; + +/// The number of bytes equivalent per signature operation. Affects transaction relay through the +/// virtual size computation. +pub const DEFAULT_BYTES_PER_SIGOP: u32 = 20; + +/// The minimum feerate, in sats per kilo-virtualbyte, for defining dust. An output is considered +/// dust if spending it under this feerate would cost more in fee. +pub const DUST_RELAY_TX_FEE: u32 = 3_000; + +/// Minimum feerate, in sats per virtual kilobyte, for a transaction to be relayed by most nodes on +/// the network. +pub const DEFAULT_MIN_RELAY_TX_FEE: u32 = 1_000; + +/// Default number of hours for an unconfirmed transaction to expire in most of the network nodes' +/// mempools. +pub const DEFAULT_MEMPOOL_EXPIRY: u32 = 336;