// licenses.
use bitcoin::blockdata::transaction::{Transaction, TxOut};
-use bitcoin::blockdata::script::Script;
+use bitcoin::blockdata::script::ScriptBuf;
use bitcoin::consensus::Encodable;
use bitcoin::consensus::encode::VarInt;
-use ln::msgs::MAX_VALUE_MSAT;
+use crate::ln::msgs::MAX_VALUE_MSAT;
+#[allow(unused_imports)]
+use crate::prelude::*;
+
+use crate::io_extras::sink;
use core::cmp::Ordering;
pub fn sort_outputs<T, C : Fn(&T, &T) -> Ordering>(outputs: &mut Vec<(TxOut, T)>, tie_breaker: C) {
});
}
-fn get_dust_value(output_script: &Script) -> u64 {
- //TODO: This belongs in rust-bitcoin (https://github.com/rust-bitcoin/rust-bitcoin/pull/566)
- if output_script.is_op_return() {
- 0
- } else if output_script.is_witness_program() {
- 294
- } else {
- 546
- }
-}
-
/// Possibly adds a change output to the given transaction, always doing so if there are excess
/// funds available beyond the requested feerate.
/// Assumes at least one input will have a witness (ie spends a segwit output).
/// Returns an Err(()) if the requested feerate cannot be met.
-pub(crate) fn maybe_add_change_output(tx: &mut Transaction, input_value: u64, witness_max_weight: usize, feerate_sat_per_1000_weight: u32, change_destination_script: Script) -> Result<(), ()> {
+/// Returns the expected maximum weight of the fully signed transaction on success.
+pub(crate) fn maybe_add_change_output(tx: &mut Transaction, input_value: u64, witness_max_weight: u64, feerate_sat_per_1000_weight: u32, change_destination_script: ScriptBuf) -> Result<u64, ()> {
if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
+ const WITNESS_FLAG_BYTES: u64 = 2;
+
let mut output_value = 0;
for output in tx.output.iter() {
output_value += output.value;
if output_value >= input_value { return Err(()); }
}
- let dust_value = get_dust_value(&change_destination_script);
+ let dust_value = change_destination_script.dust_value();
let mut change_output = TxOut {
script_pubkey: change_destination_script,
value: 0,
};
- let change_len = change_output.consensus_encode(&mut std::io::sink()).unwrap();
- let mut weight_with_change: i64 = tx.get_weight() as i64 + 2 + witness_max_weight as i64 + change_len as i64 * 4;
+ let change_len = change_output.consensus_encode(&mut sink()).unwrap();
+ let starting_weight = tx.weight().to_wu() + WITNESS_FLAG_BYTES + witness_max_weight as u64;
+ let mut weight_with_change: i64 = starting_weight as i64 + change_len as i64 * 4;
// Include any extra bytes required to push an extra output.
weight_with_change += (VarInt(tx.output.len() as u64 + 1).len() - VarInt(tx.output.len() as u64).len()) as i64 * 4;
// When calculating weight, add two for the flag bytes
let change_value: i64 = (input_value - output_value) as i64 - weight_with_change * feerate_sat_per_1000_weight as i64 / 1000;
- if change_value >= dust_value as i64 {
+ if change_value >= dust_value.to_sat() as i64 {
change_output.value = change_value as u64;
tx.output.push(change_output);
- } else if (input_value - output_value) as i64 - (tx.get_weight() as i64 + 2 + witness_max_weight as i64) * feerate_sat_per_1000_weight as i64 / 1000 < 0 {
- return Err(());
+ Ok(weight_with_change as u64)
+ } else if (input_value - output_value) as i64 - (starting_weight as i64) * feerate_sat_per_1000_weight as i64 / 1000 < 0 {
+ Err(())
+ } else {
+ Ok(starting_weight)
}
-
- Ok(())
}
#[cfg(test)]
mod tests {
use super::*;
- use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, OutPoint};
- use bitcoin::blockdata::script::{Script, Builder};
- use bitcoin::hash_types::Txid;
+ use bitcoin::blockdata::locktime::absolute::LockTime;
+ use bitcoin::blockdata::transaction::{TxIn, OutPoint};
+ use bitcoin::blockdata::script::Builder;
+ use bitcoin::hash_types::{PubkeyHash, Txid};
+ use bitcoin::hashes::Hash;
+ use bitcoin::hashes::hex::FromHex;
+ use bitcoin::{Sequence, Witness};
- use bitcoin::hashes::sha256d::Hash as Sha256dHash;
-
- use hex::decode;
+ use alloc::vec;
#[test]
fn sort_output_by_value() {
);
}
- fn script_from_hex(hex_str: &str) -> Script {
- Script::from(decode(hex_str).unwrap())
+ fn script_from_hex(hex_str: &str) -> ScriptBuf {
+ ScriptBuf::from(<Vec<u8>>::from_hex(hex_str).unwrap())
}
macro_rules! bip_txout_tests {
#[test]
fn test_tx_value_overrun() {
// If we have a bogus input amount or outputs valued more than inputs, we should fail
- let mut tx = Transaction { version: 2, lock_time: 0, input: Vec::new(), output: vec![TxOut {
- script_pubkey: Script::new(), value: 1000
+ let mut tx = Transaction { version: 2, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
+ script_pubkey: ScriptBuf::new(), value: 1000
}] };
- assert!(maybe_add_change_output(&mut tx, 21_000_000_0000_0001, 0, 253, Script::new()).is_err());
- assert!(maybe_add_change_output(&mut tx, 400, 0, 253, Script::new()).is_err());
- assert!(maybe_add_change_output(&mut tx, 4000, 0, 253, Script::new()).is_ok());
+ assert!(maybe_add_change_output(&mut tx, 21_000_000_0000_0001, 0, 253, ScriptBuf::new()).is_err());
+ assert!(maybe_add_change_output(&mut tx, 400, 0, 253, ScriptBuf::new()).is_err());
+ assert!(maybe_add_change_output(&mut tx, 4000, 0, 253, ScriptBuf::new()).is_ok());
}
#[test]
fn test_tx_change_edge() {
// Check that we never add dust outputs
- let mut tx = Transaction { version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
+ let mut tx = Transaction { version: 2, lock_time: LockTime::ZERO, input: Vec::new(), output: Vec::new() };
let orig_wtxid = tx.wtxid();
+ let output_spk = ScriptBuf::new_p2pkh(&PubkeyHash::hash(&[0; 0]));
+ assert_eq!(output_spk.dust_value().to_sat(), 546);
// 9 sats isn't enough to pay fee on a dummy transaction...
- assert_eq!(tx.get_weight() as u64, 40); // ie 10 vbytes
- assert!(maybe_add_change_output(&mut tx, 9, 0, 253, Script::new()).is_err());
+ assert_eq!(tx.weight().to_wu(), 40); // ie 10 vbytes
+ assert!(maybe_add_change_output(&mut tx, 9, 0, 250, output_spk.clone()).is_err());
assert_eq!(tx.wtxid(), orig_wtxid); // Failure doesn't change the transaction
// but 10-564 is, just not enough to add a change output...
- assert!(maybe_add_change_output(&mut tx, 10, 0, 253, Script::new()).is_ok());
+ assert!(maybe_add_change_output(&mut tx, 10, 0, 250, output_spk.clone()).is_ok());
assert_eq!(tx.output.len(), 0);
assert_eq!(tx.wtxid(), orig_wtxid); // If we don't add an output, we don't change the transaction
- assert!(maybe_add_change_output(&mut tx, 564, 0, 253, Script::new()).is_ok());
+ assert!(maybe_add_change_output(&mut tx, 549, 0, 250, output_spk.clone()).is_ok());
assert_eq!(tx.output.len(), 0);
assert_eq!(tx.wtxid(), orig_wtxid); // If we don't add an output, we don't change the transaction
- // 565 is also not enough, if we anticipate 2 more weight units pushing us up to the next vbyte
+ // 590 is also not enough, if we anticipate 2 more weight units pushing us up to the next vbyte
// (considering the two bytes for segwit flags)
- assert!(maybe_add_change_output(&mut tx, 565, 2, 253, Script::new()).is_ok());
+ assert!(maybe_add_change_output(&mut tx, 590, 2, 250, output_spk.clone()).is_ok());
assert_eq!(tx.output.len(), 0);
assert_eq!(tx.wtxid(), orig_wtxid); // If we don't add an output, we don't change the transaction
- // at 565 we can afford the change output at the dust limit (546)
- assert!(maybe_add_change_output(&mut tx, 565, 0, 253, Script::new()).is_ok());
+ // at 590 we can afford the change output at the dust limit (546)
+ assert!(maybe_add_change_output(&mut tx, 590, 0, 250, output_spk.clone()).is_ok());
assert_eq!(tx.output.len(), 1);
assert_eq!(tx.output[0].value, 546);
- assert_eq!(tx.output[0].script_pubkey, Script::new());
- assert_eq!(tx.get_weight() / 4, 565-546); // New weight is exactly the fee we wanted.
+ assert_eq!(tx.output[0].script_pubkey, output_spk);
+ assert_eq!(tx.weight().to_wu() / 4, 590-546); // New weight is exactly the fee we wanted.
tx.output.pop();
assert_eq!(tx.wtxid(), orig_wtxid); // The only change is the addition of one output.
#[test]
fn test_tx_extra_outputs() {
// Check that we correctly handle existing outputs
- let mut tx = Transaction { version: 2, lock_time: 0, input: vec![TxIn {
- previous_output: OutPoint::new(Txid::from_hash(Sha256dHash::default()), 0), script_sig: Script::new(), witness: Vec::new(), sequence: 0,
+ let mut tx = Transaction { version: 2, lock_time: LockTime::ZERO, input: vec![TxIn {
+ previous_output: OutPoint::new(Txid::all_zeros(), 0), script_sig: ScriptBuf::new(), witness: Witness::new(), sequence: Sequence::ZERO,
}], output: vec![TxOut {
script_pubkey: Builder::new().push_int(1).into_script(), value: 1000
}] };
let orig_wtxid = tx.wtxid();
- let orig_weight = tx.get_weight();
+ let orig_weight = tx.weight().to_wu();
assert_eq!(orig_weight / 4, 61);
+ assert_eq!(Builder::new().push_int(2).into_script().dust_value().to_sat(), 474);
+
// Input value of the output value + fee - 1 should fail:
assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100 - 1, 400, 250, Builder::new().push_int(2).into_script()).is_err());
assert_eq!(tx.wtxid(), orig_wtxid); // Failure doesn't change the transaction
// but one more input sat should succeed, without changing the transaction
assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100, 400, 250, Builder::new().push_int(2).into_script()).is_ok());
assert_eq!(tx.wtxid(), orig_wtxid); // If we don't add an output, we don't change the transaction
- // In order to get a change output, we need to add 546 plus the output's weight / 4 (10)...
- assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100 + 546 + 9, 400, 250, Builder::new().push_int(2).into_script()).is_ok());
+ // In order to get a change output, we need to add 474 plus the output's weight / 4 (10)...
+ assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100 + 474 + 9, 400, 250, Builder::new().push_int(2).into_script()).is_ok());
assert_eq!(tx.wtxid(), orig_wtxid); // If we don't add an output, we don't change the transaction
- assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100 + 546 + 10, 400, 250, Builder::new().push_int(2).into_script()).is_ok());
+ assert!(maybe_add_change_output(&mut tx, 1000 + 61 + 100 + 474 + 10, 400, 250, Builder::new().push_int(2).into_script()).is_ok());
assert_eq!(tx.output.len(), 2);
- assert_eq!(tx.output[1].value, 546);
+ assert_eq!(tx.output[1].value, 474);
assert_eq!(tx.output[1].script_pubkey, Builder::new().push_int(2).into_script());
- assert_eq!(tx.get_weight() - orig_weight, 40); // Weight difference matches what we had to add above
+ assert_eq!(tx.weight().to_wu() - orig_weight, 40); // Weight difference matches what we had to add above
tx.output.pop();
assert_eq!(tx.wtxid(), orig_wtxid); // The only change is the addition of one output.
}
projects / rust-lightning / blobdiff