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Migrate deprecated spendable outputs persistence.
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Original file line number | Diff line number | Diff line change |
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@@ -1,151 +1,85 @@ | ||
use std::io::{Read, Seek, SeekFrom}; | ||
use std::path::PathBuf; | ||
use std::sync::Arc; | ||
use std::time::Duration; | ||
use std::{fs, io}; | ||
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use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator}; | ||
use lightning::sign::{EntropySource, KeysManager, OutputSpender, SpendableOutputDescriptor}; | ||
use lightning::util::logger::Logger; | ||
use lightning::sign::{EntropySource, KeysManager, SpendableOutputDescriptor}; | ||
use lightning::util::persist::KVStore; | ||
use lightning::util::ser::{Readable, WithoutLength, Writeable}; | ||
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use lightning_persister::fs_store::FilesystemStore; | ||
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use bitcoin::blockdata::locktime::absolute::LockTime; | ||
use bitcoin::secp256k1::Secp256k1; | ||
use rand::{thread_rng, Rng}; | ||
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use crate::hex_utils; | ||
use crate::BitcoindClient; | ||
use crate::ChannelManager; | ||
use crate::FilesystemLogger; | ||
use crate::OutputSweeper; | ||
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const DEPRECATED_PENDING_SPENDABLE_OUTPUT_DIR: &'static str = "pending_spendable_outputs"; | ||
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/// If we have any pending claimable outputs, we should slowly sweep them to our Bitcoin Core | ||
/// wallet. We technically don't need to do this - they're ours to spend when we want and can just | ||
/// use them to build new transactions instead, but we cannot feed them direclty into Bitcoin | ||
/// Core's wallet so we have to sweep. | ||
/// | ||
/// Note that this is unececssary for [`SpendableOutputDescriptor::StaticOutput`]s, which *do* have | ||
/// an associated secret key we could simply import into Bitcoin Core's wallet, but for consistency | ||
/// we don't do that here either. | ||
pub(crate) async fn periodic_sweep( | ||
ldk_data_dir: String, keys_manager: Arc<KeysManager>, logger: Arc<FilesystemLogger>, | ||
persister: Arc<FilesystemStore>, bitcoind_client: Arc<BitcoindClient>, | ||
channel_manager: Arc<ChannelManager>, | ||
/// We updated to use LDK's OutputSweeper as part of upgrading to LDK 0.0.123, so migrate away from | ||
/// the old sweep persistence. | ||
pub(crate) async fn migrate_deprecated_spendable_outputs( | ||
ldk_data_dir: String, keys_manager: Arc<KeysManager>, persister: Arc<FilesystemStore>, | ||
sweeper: Arc<OutputSweeper>, | ||
) { | ||
// Regularly claim outputs which are exclusively spendable by us and send them to Bitcoin Core. | ||
// Note that if you more tightly integrate your wallet with LDK you may not need to do this - | ||
// these outputs can just be treated as normal outputs during coin selection. | ||
let pending_spendables_dir = | ||
format!("{}/{}", ldk_data_dir, crate::PENDING_SPENDABLE_OUTPUT_DIR); | ||
format!("{}/{}", ldk_data_dir, DEPRECATED_PENDING_SPENDABLE_OUTPUT_DIR); | ||
let processing_spendables_dir = format!("{}/processing_spendable_outputs", ldk_data_dir); | ||
let spendables_dir = format!("{}/spendable_outputs", ldk_data_dir); | ||
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// We batch together claims of all spendable outputs generated each day, however only after | ||
// batching any claims of spendable outputs which were generated prior to restart. On a mobile | ||
// device we likely won't ever be online for more than a minute, so we have to ensure we sweep | ||
// any pending claims on startup, but for an always-online node you may wish to sweep even less | ||
// frequently than this (or move the interval await to the top of the loop)! | ||
// | ||
// There is no particular rush here, we just have to ensure funds are availably by the time we | ||
// need to send funds. | ||
let mut interval = tokio::time::interval(Duration::from_secs(60 * 60 * 24)); | ||
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loop { | ||
interval.tick().await; // Note that the first tick completes immediately | ||
if let Ok(dir_iter) = fs::read_dir(&pending_spendables_dir) { | ||
// Move any spendable descriptors from pending folder so that we don't have any | ||
// races with new files being added. | ||
for file_res in dir_iter { | ||
let file = file_res.unwrap(); | ||
// Only move a file if its a 32-byte-hex'd filename, otherwise it might be a | ||
// temporary file. | ||
if file.file_name().len() == 64 { | ||
fs::create_dir_all(&processing_spendables_dir).unwrap(); | ||
let mut holding_path = PathBuf::new(); | ||
holding_path.push(&processing_spendables_dir); | ||
holding_path.push(&file.file_name()); | ||
fs::rename(file.path(), holding_path).unwrap(); | ||
} | ||
if let Ok(dir_iter) = fs::read_dir(&pending_spendables_dir) { | ||
// Move any spendable descriptors from pending folder so that we don't have any | ||
// races with new files being added. | ||
for file_res in dir_iter { | ||
let file = file_res.unwrap(); | ||
// Only move a file if its a 32-byte-hex'd filename, otherwise it might be a | ||
// temporary file. | ||
if file.file_name().len() == 64 { | ||
fs::create_dir_all(&processing_spendables_dir).unwrap(); | ||
let mut holding_path = PathBuf::new(); | ||
holding_path.push(&processing_spendables_dir); | ||
holding_path.push(&file.file_name()); | ||
fs::rename(file.path(), holding_path).unwrap(); | ||
} | ||
// Now concatenate all the pending files we moved into one file in the | ||
// `spendable_outputs` directory and drop the processing directory. | ||
let mut outputs = Vec::new(); | ||
if let Ok(processing_iter) = fs::read_dir(&processing_spendables_dir) { | ||
for file_res in processing_iter { | ||
outputs.append(&mut fs::read(file_res.unwrap().path()).unwrap()); | ||
} | ||
} | ||
if !outputs.is_empty() { | ||
let key = hex_utils::hex_str(&keys_manager.get_secure_random_bytes()); | ||
persister | ||
.write("spendable_outputs", "", &key, &WithoutLength(&outputs).encode()) | ||
.unwrap(); | ||
fs::remove_dir_all(&processing_spendables_dir).unwrap(); | ||
} | ||
// Now concatenate all the pending files we moved into one file in the | ||
// `spendable_outputs` directory and drop the processing directory. | ||
let mut outputs = Vec::new(); | ||
if let Ok(processing_iter) = fs::read_dir(&processing_spendables_dir) { | ||
for file_res in processing_iter { | ||
outputs.append(&mut fs::read(file_res.unwrap().path()).unwrap()); | ||
} | ||
} | ||
// Iterate over all the sets of spendable outputs in `spendables_dir` and try to claim | ||
// them. | ||
// Note that here we try to claim each set of spendable outputs over and over again | ||
// forever, even long after its been claimed. While this isn't an issue per se, in practice | ||
// you may wish to track when the claiming transaction has confirmed and remove the | ||
// spendable outputs set. You may also wish to merge groups of unspent spendable outputs to | ||
// combine batches. | ||
if let Ok(dir_iter) = fs::read_dir(&spendables_dir) { | ||
for file_res in dir_iter { | ||
let mut outputs: Vec<SpendableOutputDescriptor> = Vec::new(); | ||
let mut file = fs::File::open(file_res.unwrap().path()).unwrap(); | ||
loop { | ||
// Check if there are any bytes left to read, and if so read a descriptor. | ||
match file.read_exact(&mut [0; 1]) { | ||
Ok(_) => { | ||
file.seek(SeekFrom::Current(-1)).unwrap(); | ||
}, | ||
Err(e) if e.kind() == io::ErrorKind::UnexpectedEof => break, | ||
Err(e) => Err(e).unwrap(), | ||
} | ||
outputs.push(Readable::read(&mut file).unwrap()); | ||
} | ||
let destination_address = bitcoind_client.get_new_address().await; | ||
let output_descriptors = &outputs.iter().map(|a| a).collect::<Vec<_>>(); | ||
let tx_feerate = bitcoind_client | ||
.get_est_sat_per_1000_weight(ConfirmationTarget::ChannelCloseMinimum); | ||
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// We set nLockTime to the current height to discourage fee sniping. | ||
// Occasionally randomly pick a nLockTime even further back, so | ||
// that transactions that are delayed after signing for whatever reason, | ||
// e.g. high-latency mix networks and some CoinJoin implementations, have | ||
// better privacy. | ||
// Logic copied from core: https://github.com/bitcoin/bitcoin/blob/1d4846a8443be901b8a5deb0e357481af22838d0/src/wallet/spend.cpp#L936 | ||
let mut cur_height = channel_manager.current_best_block().height; | ||
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// 10% of the time | ||
if thread_rng().gen_range(0, 10) == 0 { | ||
// subtract random number between 0 and 100 | ||
cur_height = cur_height.saturating_sub(thread_rng().gen_range(0, 100)); | ||
} | ||
if !outputs.is_empty() { | ||
let key = hex_utils::hex_str(&keys_manager.get_secure_random_bytes()); | ||
persister | ||
.write("spendable_outputs", "", &key, &WithoutLength(&outputs).encode()) | ||
.unwrap(); | ||
fs::remove_dir_all(&processing_spendables_dir).unwrap(); | ||
} | ||
} | ||
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let locktime = | ||
LockTime::from_height(cur_height).map_or(LockTime::ZERO, |l| l.into()); | ||
let best_block = sweeper.current_best_block(); | ||
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if let Ok(spending_tx) = keys_manager.spend_spendable_outputs( | ||
output_descriptors, | ||
Vec::new(), | ||
destination_address.script_pubkey(), | ||
tx_feerate, | ||
Some(locktime), | ||
&Secp256k1::new(), | ||
) { | ||
// Note that, most likely, we've already sweeped this set of outputs | ||
// and they're already confirmed on-chain, so this broadcast will fail. | ||
bitcoind_client.broadcast_transactions(&[&spending_tx]); | ||
} else { | ||
lightning::log_error!( | ||
logger, | ||
"Failed to sweep spendable outputs! This may indicate the outputs are dust. Will try again in a day."); | ||
let mut outputs: Vec<SpendableOutputDescriptor> = Vec::new(); | ||
if let Ok(dir_iter) = fs::read_dir(&spendables_dir) { | ||
for file_res in dir_iter { | ||
let mut file = fs::File::open(file_res.unwrap().path()).unwrap(); | ||
loop { | ||
// Check if there are any bytes left to read, and if so read a descriptor. | ||
match file.read_exact(&mut [0; 1]) { | ||
Ok(_) => { | ||
file.seek(SeekFrom::Current(-1)).unwrap(); | ||
}, | ||
Err(e) if e.kind() == io::ErrorKind::UnexpectedEof => break, | ||
Err(e) => Err(e).unwrap(), | ||
} | ||
outputs.push(Readable::read(&mut file).unwrap()); | ||
} | ||
} | ||
} | ||
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let spend_delay = Some(best_block.height + 2); | ||
sweeper.track_spendable_outputs(outputs.clone(), None, true, spend_delay).unwrap(); | ||
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fs::remove_dir_all(&spendables_dir).unwrap(); | ||
fs::remove_dir_all(&pending_spendables_dir).unwrap(); | ||
} |