_ Git - rust-lightning/blob - lightning/src/util/persist.rs

   1 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   2 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   3 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   4 // You may not use this file except in accordance with one or both of these
   5 // licenses.
   6
   7 //! This module contains a simple key-value store trait [`KVStore`] that
   8 //! allows one to implement the persistence for [`ChannelManager`], [`NetworkGraph`],
   9 //! and [`ChannelMonitor`] all in one place.
  10
  11 use core::cmp;
  12 use core::convert::{TryFrom, TryInto};
  13 use core::ops::Deref;
  14 use core::str::FromStr;
  15 use bitcoin::{BlockHash, Txid};
  16
  17 use crate::{io, log_error};
  18 use crate::alloc::string::ToString;
  19 use crate::prelude::*;
  20
  21 use crate::chain;
  22 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  23 use crate::chain::chainmonitor::{Persist, MonitorUpdateId};
  24 use crate::sign::{EntropySource, NodeSigner, ecdsa::WriteableEcdsaChannelSigner, SignerProvider};
  25 use crate::chain::transaction::OutPoint;
  26 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, CLOSED_CHANNEL_UPDATE_ID};
  27 use crate::ln::channelmanager::ChannelManager;
  28 use crate::routing::router::Router;
  29 use crate::routing::gossip::NetworkGraph;
  30 use crate::routing::scoring::WriteableScore;
  31 use crate::util::logger::Logger;
  32 use crate::util::ser::{Readable, ReadableArgs, Writeable};
  33
  34 /// The alphabet of characters allowed for namespaces and keys.
  35 pub const KVSTORE_NAMESPACE_KEY_ALPHABET: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
  36
  37 /// The maximum number of characters namespaces and keys may have.
  38 pub const KVSTORE_NAMESPACE_KEY_MAX_LEN: usize = 120;
  39
  40 /// The primary namespace under which the [`ChannelManager`] will be persisted.
  41 pub const CHANNEL_MANAGER_PERSISTENCE_PRIMARY_NAMESPACE: &str = "";
  42 /// The secondary namespace under which the [`ChannelManager`] will be persisted.
  43 pub const CHANNEL_MANAGER_PERSISTENCE_SECONDARY_NAMESPACE: &str = "";
  44 /// The key under which the [`ChannelManager`] will be persisted.
  45 pub const CHANNEL_MANAGER_PERSISTENCE_KEY: &str = "manager";
  46
  47 /// The primary namespace under which [`ChannelMonitor`]s will be persisted.
  48 pub const CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE: &str = "monitors";
  49 /// The secondary namespace under which [`ChannelMonitor`]s will be persisted.
  50 pub const CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE: &str = "";
  51 /// The primary namespace under which [`ChannelMonitorUpdate`]s will be persisted.
  52 pub const CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE: &str = "monitor_updates";
  53
  54 /// The primary namespace under which the [`NetworkGraph`] will be persisted.
  55 pub const NETWORK_GRAPH_PERSISTENCE_PRIMARY_NAMESPACE: &str = "";
  56 /// The secondary namespace under which the [`NetworkGraph`] will be persisted.
  57 pub const NETWORK_GRAPH_PERSISTENCE_SECONDARY_NAMESPACE: &str = "";
  58 /// The key under which the [`NetworkGraph`] will be persisted.
  59 pub const NETWORK_GRAPH_PERSISTENCE_KEY: &str = "network_graph";
  60
  61 /// The primary namespace under which the [`WriteableScore`] will be persisted.
  62 pub const SCORER_PERSISTENCE_PRIMARY_NAMESPACE: &str = "";
  63 /// The secondary namespace under which the [`WriteableScore`] will be persisted.
  64 pub const SCORER_PERSISTENCE_SECONDARY_NAMESPACE: &str = "";
  65 /// The key under which the [`WriteableScore`] will be persisted.
  66 pub const SCORER_PERSISTENCE_KEY: &str = "scorer";
  67
  68 /// A sentinel value to be prepended to monitors persisted by the [`MonitorUpdatingPersister`].
  69 ///
  70 /// This serves to prevent someone from accidentally loading such monitors (which may need
  71 /// updates applied to be current) with another implementation.
  72 pub const MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL: &[u8] = &[0xFF; 2];
  73
  74 /// Provides an interface that allows storage and retrieval of persisted values that are associated
  75 /// with given keys.
  76 ///
  77 /// In order to avoid collisions the key space is segmented based on the given `primary_namespace`s
  78 /// and `secondary_namespace`s. Implementations of this trait are free to handle them in different
  79 /// ways, as long as per-namespace key uniqueness is asserted.
  80 ///
  81 /// Keys and namespaces are required to be valid ASCII strings in the range of
  82 /// [`KVSTORE_NAMESPACE_KEY_ALPHABET`] and no longer than [`KVSTORE_NAMESPACE_KEY_MAX_LEN`]. Empty
  83 /// primary namespaces and secondary namespaces (`""`) are assumed to be a valid, however, if
  84 /// `primary_namespace` is empty, `secondary_namespace` is required to be empty, too. This means
  85 /// that concerns should always be separated by primary namespace first, before secondary
  86 /// namespaces are used. While the number of primary namespaces will be relatively small and is
  87 /// determined at compile time, there may be many secondary namespaces per primary namespace. Note
  88 /// that per-namespace uniqueness needs to also hold for keys *and* namespaces in any given
  89 /// namespace, i.e., conflicts between keys and equally named
  90 /// primary namespaces/secondary namespaces must be avoided.
  91 ///
  92 /// **Note:** Users migrating custom persistence backends from the pre-v0.0.117 `KVStorePersister`
  93 /// interface can use a concatenation of `[{primary_namespace}/[{secondary_namespace}/]]{key}` to
  94 /// recover a `key` compatible with the data model previously assumed by `KVStorePersister::persist`.
  95 pub trait KVStore {
  96         /// Returns the data stored for the given `primary_namespace`, `secondary_namespace`, and
  97         /// `key`.
  98         ///
  99         /// Returns an [`ErrorKind::NotFound`] if the given `key` could not be found in the given
 100         /// `primary_namespace` and `secondary_namespace`.
 101         ///
 102         /// [`ErrorKind::NotFound`]: io::ErrorKind::NotFound
 103         fn read(&self, primary_namespace: &str, secondary_namespace: &str, key: &str) -> Result<Vec<u8>, io::Error>;
 104         /// Persists the given data under the given `key`.
 105         ///
 106         /// Will create the given `primary_namespace` and `secondary_namespace` if not already present
 107         /// in the store.
 108         fn write(&self, primary_namespace: &str, secondary_namespace: &str, key: &str, buf: &[u8]) -> Result<(), io::Error>;
 109         /// Removes any data that had previously been persisted under the given `key`.
 110         ///
 111         /// If the `lazy` flag is set to `true`, the backend implementation might choose to lazily
 112         /// remove the given `key` at some point in time after the method returns, e.g., as part of an
 113         /// eventual batch deletion of multiple keys. As a consequence, subsequent calls to
 114         /// [`KVStore::list`] might include the removed key until the changes are actually persisted.
 115         ///
 116         /// Note that while setting the `lazy` flag reduces the I/O burden of multiple subsequent
 117         /// `remove` calls, it also influences the atomicity guarantees as lazy `remove`s could
 118         /// potentially get lost on crash after the method returns. Therefore, this flag should only be
 119         /// set for `remove` operations that can be safely replayed at a later time.
 120         ///
 121         /// Returns successfully if no data will be stored for the given `primary_namespace`,
 122         /// `secondary_namespace`, and `key`, independently of whether it was present before its
 123         /// invokation or not.
 124         fn remove(&self, primary_namespace: &str, secondary_namespace: &str, key: &str, lazy: bool) -> Result<(), io::Error>;
 125         /// Returns a list of keys that are stored under the given `secondary_namespace` in
 126         /// `primary_namespace`.
 127         ///
 128         /// Returns the keys in arbitrary order, so users requiring a particular order need to sort the
 129         /// returned keys. Returns an empty list if `primary_namespace` or `secondary_namespace` is unknown.
 130         fn list(&self, primary_namespace: &str, secondary_namespace: &str) -> Result<Vec<String>, io::Error>;
 131 }
 132
 133 /// Trait that handles persisting a [`ChannelManager`], [`NetworkGraph`], and [`WriteableScore`] to disk.
 134 pub trait Persister<'a, M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref, S: WriteableScore<'a>>
 135         where M::Target: 'static + chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
 136                 T::Target: 'static + BroadcasterInterface,
 137                 ES::Target: 'static + EntropySource,
 138                 NS::Target: 'static + NodeSigner,
 139                 SP::Target: 'static + SignerProvider,
 140                 F::Target: 'static + FeeEstimator,
 141                 R::Target: 'static + Router,
 142                 L::Target: 'static + Logger,
 143 {
 144         /// Persist the given ['ChannelManager'] to disk, returning an error if persistence failed.
 145         fn persist_manager(&self, channel_manager: &ChannelManager<M, T, ES, NS, SP, F, R, L>) -> Result<(), io::Error>;
 146
 147         /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
 148         fn persist_graph(&self, network_graph: &NetworkGraph<L>) -> Result<(), io::Error>;
 149
 150         /// Persist the given [`WriteableScore`] to disk, returning an error if persistence failed.
 151         fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error>;
 152 }
 153
 154
 155 impl<'a, A: KVStore, M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, M, T, ES, NS, SP, F, R, L, S> for A
 156         where M::Target: 'static + chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
 157                 T::Target: 'static + BroadcasterInterface,
 158                 ES::Target: 'static + EntropySource,
 159                 NS::Target: 'static + NodeSigner,
 160                 SP::Target: 'static + SignerProvider,
 161                 F::Target: 'static + FeeEstimator,
 162                 R::Target: 'static + Router,
 163                 L::Target: 'static + Logger,
 164 {
 165         /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed.
 166         fn persist_manager(&self, channel_manager: &ChannelManager<M, T, ES, NS, SP, F, R, L>) -> Result<(), io::Error> {
 167                 self.write(CHANNEL_MANAGER_PERSISTENCE_PRIMARY_NAMESPACE,
 168                         CHANNEL_MANAGER_PERSISTENCE_SECONDARY_NAMESPACE,
 169                         CHANNEL_MANAGER_PERSISTENCE_KEY,
 170                         &channel_manager.encode())
 171         }
 172
 173         /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
 174         fn persist_graph(&self, network_graph: &NetworkGraph<L>) -> Result<(), io::Error> {
 175                 self.write(NETWORK_GRAPH_PERSISTENCE_PRIMARY_NAMESPACE,
 176                         NETWORK_GRAPH_PERSISTENCE_SECONDARY_NAMESPACE,
 177                         NETWORK_GRAPH_PERSISTENCE_KEY,
 178                         &network_graph.encode())
 179         }
 180
 181         /// Persist the given [`WriteableScore`] to disk, returning an error if persistence failed.
 182         fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error> {
 183                 self.write(SCORER_PERSISTENCE_PRIMARY_NAMESPACE,
 184                         SCORER_PERSISTENCE_SECONDARY_NAMESPACE,
 185                         SCORER_PERSISTENCE_KEY,
 186                         &scorer.encode())
 187         }
 188 }
 189
 190 impl<'a, M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, M, T, ES, NS, SP, F, R, L, S> for dyn KVStore + Send + Sync
 191         where M::Target: 'static + chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
 192                 T::Target: 'static + BroadcasterInterface,
 193                 ES::Target: 'static + EntropySource,
 194                 NS::Target: 'static + NodeSigner,
 195                 SP::Target: 'static + SignerProvider,
 196                 F::Target: 'static + FeeEstimator,
 197                 R::Target: 'static + Router,
 198                 L::Target: 'static + Logger,
 199 {
 200         /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed.
 201         fn persist_manager(&self, channel_manager: &ChannelManager<M, T, ES, NS, SP, F, R, L>) -> Result<(), io::Error> {
 202                 self.write(CHANNEL_MANAGER_PERSISTENCE_PRIMARY_NAMESPACE,
 203                         CHANNEL_MANAGER_PERSISTENCE_SECONDARY_NAMESPACE,
 204                         CHANNEL_MANAGER_PERSISTENCE_KEY,
 205                         &channel_manager.encode())
 206         }
 207
 208         /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
 209         fn persist_graph(&self, network_graph: &NetworkGraph<L>) -> Result<(), io::Error> {
 210                 self.write(NETWORK_GRAPH_PERSISTENCE_PRIMARY_NAMESPACE,
 211                         NETWORK_GRAPH_PERSISTENCE_SECONDARY_NAMESPACE,
 212                         NETWORK_GRAPH_PERSISTENCE_KEY,
 213                         &network_graph.encode())
 214         }
 215
 216         /// Persist the given [`WriteableScore`] to disk, returning an error if persistence failed.
 217         fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error> {
 218                 self.write(SCORER_PERSISTENCE_PRIMARY_NAMESPACE,
 219                         SCORER_PERSISTENCE_SECONDARY_NAMESPACE,
 220                         SCORER_PERSISTENCE_KEY,
 221                         &scorer.encode())
 222         }
 223 }
 224
 225 impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStore> Persist<ChannelSigner> for K {
 226         // TODO: We really need a way for the persister to inform the user that its time to crash/shut
 227         // down once these start returning failure.
 228         // Then we should return InProgress rather than UnrecoverableError, implying we should probably
 229         // just shut down the node since we're not retrying persistence!
 230
 231         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
 232                 let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
 233                 match self.write(
 234                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 235                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 236                         &key, &monitor.encode())
 237                 {
 238                         Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
 239                         Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
 240                 }
 241         }
 242
 243         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: Option<&ChannelMonitorUpdate>, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
 244                 let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
 245                 match self.write(
 246                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 247                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 248                         &key, &monitor.encode())
 249                 {
 250                         Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
 251                         Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
 252                 }
 253         }
 254 }
 255
 256 impl<ChannelSigner: WriteableEcdsaChannelSigner> Persist<ChannelSigner> for dyn KVStore + Send + Sync {
 257         // TODO: We really need a way for the persister to inform the user that its time to crash/shut
 258         // down once these start returning failure.
 259         // Then we should return InProgress rather than UnrecoverableError, implying we should probably
 260         // just shut down the node since we're not retrying persistence!
 261
 262         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
 263                 let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
 264                 match self.write(
 265                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 266                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 267                         &key, &monitor.encode())
 268                 {
 269                         Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
 270                         Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
 271                 }
 272         }
 273
 274         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: Option<&ChannelMonitorUpdate>, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
 275                 let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
 276                 match self.write(
 277                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 278                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 279                         &key, &monitor.encode())
 280                 {
 281                         Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
 282                         Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
 283                 }
 284         }
 285 }
 286
 287 /// Read previously persisted [`ChannelMonitor`]s from the store.
 288 pub fn read_channel_monitors<K: Deref, ES: Deref, SP: Deref>(
 289         kv_store: K, entropy_source: ES, signer_provider: SP,
 290 ) -> Result<Vec<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>)>, io::Error>
 291 where
 292         K::Target: KVStore,
 293         ES::Target: EntropySource + Sized,
 294         SP::Target: SignerProvider + Sized,
 295 {
 296         let mut res = Vec::new();
 297
 298         for stored_key in kv_store.list(
 299                 CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE, CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE)?
 300         {
 301                 if stored_key.len() < 66 {
 302                         return Err(io::Error::new(
 303                                 io::ErrorKind::InvalidData,
 304                                 "Stored key has invalid length"));
 305                 }
 306
 307                 let txid = Txid::from_str(stored_key.split_at(64).0).map_err(|_| {
 308                         io::Error::new(io::ErrorKind::InvalidData, "Invalid tx ID in stored key")
 309                 })?;
 310
 311                 let index: u16 = stored_key.split_at(65).1.parse().map_err(|_| {
 312                         io::Error::new(io::ErrorKind::InvalidData, "Invalid tx index in stored key")
 313                 })?;
 314
 315                 match <(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>)>::read(
 316                         &mut io::Cursor::new(
 317                                 kv_store.read(CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE, CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE, &stored_key)?),
 318                         (&*entropy_source, &*signer_provider),
 319                 ) {
 320                         Ok((block_hash, channel_monitor)) => {
 321                                 if channel_monitor.get_funding_txo().0.txid != txid
 322                                         || channel_monitor.get_funding_txo().0.index != index
 323                                 {
 324                                         return Err(io::Error::new(
 325                                                 io::ErrorKind::InvalidData,
 326                                                 "ChannelMonitor was stored under the wrong key",
 327                                         ));
 328                                 }
 329                                 res.push((block_hash, channel_monitor));
 330                         }
 331                         Err(_) => {
 332                                 return Err(io::Error::new(
 333                                         io::ErrorKind::InvalidData,
 334                                         "Failed to read ChannelMonitor"
 335                                 ))
 336                         }
 337                 }
 338         }
 339         Ok(res)
 340 }
 341
 342 /// Implements [`Persist`] in a way that writes and reads both [`ChannelMonitor`]s and
 343 /// [`ChannelMonitorUpdate`]s.
 344 ///
 345 /// # Overview
 346 ///
 347 /// The main benefit this provides over the [`KVStore`]'s [`Persist`] implementation is decreased
 348 /// I/O bandwidth and storage churn, at the expense of more IOPS (including listing, reading, and
 349 /// deleting) and complexity. This is because it writes channel monitor differential updates,
 350 /// whereas the other (default) implementation rewrites the entire monitor on each update. For
 351 /// routing nodes, updates can happen many times per second to a channel, and monitors can be tens
 352 /// of megabytes (or more). Updates can be as small as a few hundred bytes.
 353 ///
 354 /// Note that monitors written with `MonitorUpdatingPersister` are _not_ backward-compatible with
 355 /// the default [`KVStore`]'s [`Persist`] implementation. They have a prepended byte sequence,
 356 /// [`MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL`], applied to prevent deserialization with other
 357 /// persisters. This is because monitors written by this struct _may_ have unapplied updates. In
 358 /// order to downgrade, you must ensure that all updates are applied to the monitor, and remove the
 359 /// sentinel bytes.
 360 ///
 361 /// # Storing monitors
 362 ///
 363 /// Monitors are stored by implementing the [`Persist`] trait, which has two functions:
 364 ///
 365 ///   - [`Persist::persist_new_channel`], which persists whole [`ChannelMonitor`]s.
 366 ///   - [`Persist::update_persisted_channel`], which persists only a [`ChannelMonitorUpdate`]
 367 ///
 368 /// Whole [`ChannelMonitor`]s are stored in the [`CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE`],
 369 /// using the familiar encoding of an [`OutPoint`] (for example, `[SOME-64-CHAR-HEX-STRING]_1`).
 370 ///
 371 /// Each [`ChannelMonitorUpdate`] is stored in a dynamic secondary namespace, as follows:
 372 ///
 373 ///   - primary namespace: [`CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE`]
 374 ///   - secondary namespace: [the monitor's encoded outpoint name]
 375 ///
 376 /// Under that secondary namespace, each update is stored with a number string, like `21`, which
 377 /// represents its `update_id` value.
 378 ///
 379 /// For example, consider this channel, named for its transaction ID and index, or [`OutPoint`]:
 380 ///
 381 ///   - Transaction ID: `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef`
 382 ///   - Index: `1`
 383 ///
 384 /// Full channel monitors would be stored at a single key:
 385 ///
 386 /// `[CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1`
 387 ///
 388 /// Updates would be stored as follows (with `/` delimiting primary_namespace/secondary_namespace/key):
 389 ///
 390 /// ```text
 391 /// [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/1
 392 /// [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/2
 393 /// [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/3
 394 /// ```
 395 /// ... and so on.
 396 ///
 397 /// # Reading channel state from storage
 398 ///
 399 /// Channel state can be reconstructed by calling
 400 /// [`MonitorUpdatingPersister::read_all_channel_monitors_with_updates`]. Alternatively, users can
 401 /// list channel monitors themselves and load channels individually using
 402 /// [`MonitorUpdatingPersister::read_channel_monitor_with_updates`].
 403 ///
 404 /// ## EXTREMELY IMPORTANT
 405 ///
 406 /// It is extremely important that your [`KVStore::read`] implementation uses the
 407 /// [`io::ErrorKind::NotFound`] variant correctly: that is, when a file is not found, and _only_ in
 408 /// that circumstance (not when there is really a permissions error, for example). This is because
 409 /// neither channel monitor reading function lists updates. Instead, either reads the monitor, and
 410 /// using its stored `update_id`, synthesizes update storage keys, and tries them in sequence until
 411 /// one is not found. All _other_ errors will be bubbled up in the function's [`Result`].
 412 ///
 413 /// # Pruning stale channel updates
 414 ///
 415 /// Stale updates are pruned when the consolidation threshold is reached according to `maximum_pending_updates`.
 416 /// Monitor updates in the range between the latest `update_id` and `update_id - maximum_pending_updates`
 417 /// are deleted.
 418 /// The `lazy` flag is used on the [`KVStore::remove`] method, so there are no guarantees that the deletions
 419 /// will complete. However, stale updates are not a problem for data integrity, since updates are
 420 /// only read that are higher than the stored [`ChannelMonitor`]'s `update_id`.
 421 ///
 422 /// If you have many stale updates stored (such as after a crash with pending lazy deletes), and
 423 /// would like to get rid of them, consider using the
 424 /// [`MonitorUpdatingPersister::cleanup_stale_updates`] function.
 425 pub struct MonitorUpdatingPersister<K: Deref, L: Deref, ES: Deref, SP: Deref>
 426 where
 427         K::Target: KVStore,
 428         L::Target: Logger,
 429         ES::Target: EntropySource + Sized,
 430         SP::Target: SignerProvider + Sized,
 431 {
 432         kv_store: K,
 433         logger: L,
 434         maximum_pending_updates: u64,
 435         entropy_source: ES,
 436         signer_provider: SP,
 437 }
 438
 439 #[allow(dead_code)]
 440 impl<K: Deref, L: Deref, ES: Deref, SP: Deref>
 441         MonitorUpdatingPersister<K, L, ES, SP>
 442 where
 443         K::Target: KVStore,
 444         L::Target: Logger,
 445         ES::Target: EntropySource + Sized,
 446         SP::Target: SignerProvider + Sized,
 447 {
 448         /// Constructs a new [`MonitorUpdatingPersister`].
 449         ///
 450         /// The `maximum_pending_updates` parameter controls how many updates may be stored before a
 451         /// [`MonitorUpdatingPersister`] consolidates updates by writing a full monitor. Note that
 452         /// consolidation will frequently occur with fewer updates than what you set here; this number
 453         /// is merely the maximum that may be stored. When setting this value, consider that for higher
 454         /// values of `maximum_pending_updates`:
 455         ///
 456         ///   - [`MonitorUpdatingPersister`] will tend to write more [`ChannelMonitorUpdate`]s than
 457         /// [`ChannelMonitor`]s, approaching one [`ChannelMonitor`] write for every
 458         /// `maximum_pending_updates` [`ChannelMonitorUpdate`]s.
 459         ///   - [`MonitorUpdatingPersister`] will issue deletes differently. Lazy deletes will come in
 460         /// "waves" for each [`ChannelMonitor`] write. A larger `maximum_pending_updates` means bigger,
 461         /// less frequent "waves."
 462         ///   - [`MonitorUpdatingPersister`] will potentially have more listing to do if you need to run
 463         /// [`MonitorUpdatingPersister::cleanup_stale_updates`].
 464         pub fn new(
 465                 kv_store: K, logger: L, maximum_pending_updates: u64, entropy_source: ES,
 466                 signer_provider: SP,
 467         ) -> Self {
 468                 MonitorUpdatingPersister {
 469                         kv_store,
 470                         logger,
 471                         maximum_pending_updates,
 472                         entropy_source,
 473                         signer_provider,
 474                 }
 475         }
 476
 477         /// Reads all stored channel monitors, along with any stored updates for them.
 478         ///
 479         /// It is extremely important that your [`KVStore::read`] implementation uses the
 480         /// [`io::ErrorKind::NotFound`] variant correctly. For more information, please see the
 481         /// documentation for [`MonitorUpdatingPersister`].
 482         pub fn read_all_channel_monitors_with_updates<B: Deref, F: Deref>(
 483                 &self, broadcaster: &B, fee_estimator: &F,
 484         ) -> Result<Vec<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>)>, io::Error>
 485         where
 486                 B::Target: BroadcasterInterface,
 487                 F::Target: FeeEstimator,
 488         {
 489                 let monitor_list = self.kv_store.list(
 490                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 491                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 492                 )?;
 493                 let mut res = Vec::with_capacity(monitor_list.len());
 494                 for monitor_key in monitor_list {
 495                         res.push(self.read_channel_monitor_with_updates(
 496                                 broadcaster,
 497                                 fee_estimator,
 498                                 monitor_key,
 499                         )?)
 500                 }
 501                 Ok(res)
 502         }
 503
 504         /// Read a single channel monitor, along with any stored updates for it.
 505         ///
 506         /// It is extremely important that your [`KVStore::read`] implementation uses the
 507         /// [`io::ErrorKind::NotFound`] variant correctly. For more information, please see the
 508         /// documentation for [`MonitorUpdatingPersister`].
 509         ///
 510         /// For `monitor_key`, channel storage keys be the channel's transaction ID and index, or
 511         /// [`OutPoint`], with an underscore `_` between them. For example, given:
 512         ///
 513         ///   - Transaction ID: `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef`
 514         ///   - Index: `1`
 515         ///
 516         /// The correct `monitor_key` would be:
 517         /// `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1`
 518         ///
 519         /// Loading a large number of monitors will be faster if done in parallel. You can use this
 520         /// function to accomplish this. Take care to limit the number of parallel readers.
 521         pub fn read_channel_monitor_with_updates<B: Deref, F: Deref>(
 522                 &self, broadcaster: &B, fee_estimator: &F, monitor_key: String,
 523         ) -> Result<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>), io::Error>
 524         where
 525                 B::Target: BroadcasterInterface,
 526                 F::Target: FeeEstimator,
 527         {
 528                 let monitor_name = MonitorName::new(monitor_key)?;
 529                 let (block_hash, monitor) = self.read_monitor(&monitor_name)?;
 530                 let mut current_update_id = monitor.get_latest_update_id();
 531                 loop {
 532                         current_update_id = match current_update_id.checked_add(1) {
 533                                 Some(next_update_id) => next_update_id,
 534                                 None => break,
 535                         };
 536                         let update_name = UpdateName::from(current_update_id);
 537                         let update = match self.read_monitor_update(&monitor_name, &update_name) {
 538                                 Ok(update) => update,
 539                                 Err(err) if err.kind() == io::ErrorKind::NotFound => {
 540                                         // We can't find any more updates, so we are done.
 541                                         break;
 542                                 }
 543                                 Err(err) => return Err(err),
 544                         };
 545
 546                         monitor.update_monitor(&update, broadcaster, fee_estimator, &self.logger)
 547                                 .map_err(|e| {
 548                                         log_error!(
 549                                                 self.logger,
 550                                                 "Monitor update failed. monitor: {} update: {} reason: {:?}",
 551                                                 monitor_name.as_str(),
 552                                                 update_name.as_str(),
 553                                                 e
 554                                         );
 555                                         io::Error::new(io::ErrorKind::Other, "Monitor update failed")
 556                                 })?;
 557                 }
 558                 Ok((block_hash, monitor))
 559         }
 560
 561         /// Read a channel monitor.
 562         fn read_monitor(
 563                 &self, monitor_name: &MonitorName,
 564         ) -> Result<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>), io::Error> {
 565                 let outpoint: OutPoint = monitor_name.try_into()?;
 566                 let mut monitor_cursor = io::Cursor::new(self.kv_store.read(
 567                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 568                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 569                         monitor_name.as_str(),
 570                 )?);
 571                 // Discard the sentinel bytes if found.
 572                 if monitor_cursor.get_ref().starts_with(MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL) {
 573                         monitor_cursor.set_position(MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL.len() as u64);
 574                 }
 575                 match <(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>)>::read(
 576                         &mut monitor_cursor,
 577                         (&*self.entropy_source, &*self.signer_provider),
 578                 ) {
 579                         Ok((blockhash, channel_monitor)) => {
 580                                 if channel_monitor.get_funding_txo().0.txid != outpoint.txid
 581                                         || channel_monitor.get_funding_txo().0.index != outpoint.index
 582                                 {
 583                                         log_error!(
 584                                                 self.logger,
 585                                                 "ChannelMonitor {} was stored under the wrong key!",
 586                                                 monitor_name.as_str()
 587                                         );
 588                                         Err(io::Error::new(
 589                                                 io::ErrorKind::InvalidData,
 590                                                 "ChannelMonitor was stored under the wrong key",
 591                                         ))
 592                                 } else {
 593                                         Ok((blockhash, channel_monitor))
 594                                 }
 595                         }
 596                         Err(e) => {
 597                                 log_error!(
 598                                         self.logger,
 599                                         "Failed to read ChannelMonitor {}, reason: {}",
 600                                         monitor_name.as_str(),
 601                                         e,
 602                                 );
 603                                 Err(io::Error::new(io::ErrorKind::InvalidData, "Failed to read ChannelMonitor"))
 604                         }
 605                 }
 606         }
 607
 608         /// Read a channel monitor update.
 609         fn read_monitor_update(
 610                 &self, monitor_name: &MonitorName, update_name: &UpdateName,
 611         ) -> Result<ChannelMonitorUpdate, io::Error> {
 612                 let update_bytes = self.kv_store.read(
 613                         CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 614                         monitor_name.as_str(),
 615                         update_name.as_str(),
 616                 )?;
 617                 ChannelMonitorUpdate::read(&mut io::Cursor::new(update_bytes)).map_err(|e| {
 618                         log_error!(
 619                                 self.logger,
 620                                 "Failed to read ChannelMonitorUpdate {}/{}/{}, reason: {}",
 621                                 CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 622                                 monitor_name.as_str(),
 623                                 update_name.as_str(),
 624                                 e,
 625                         );
 626                         io::Error::new(io::ErrorKind::InvalidData, "Failed to read ChannelMonitorUpdate")
 627                 })
 628         }
 629
 630         /// Cleans up stale updates for all monitors.
 631         ///
 632         /// This function works by first listing all monitors, and then for each of them, listing all
 633         /// updates. The updates that have an `update_id` less than or equal to than the stored monitor
 634         /// are deleted. The deletion can either be lazy or non-lazy based on the `lazy` flag; this will
 635         /// be passed to [`KVStore::remove`].
 636         pub fn cleanup_stale_updates(&self, lazy: bool) -> Result<(), io::Error> {
 637                 let monitor_keys = self.kv_store.list(
 638                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 639                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 640                 )?;
 641                 for monitor_key in monitor_keys {
 642                         let monitor_name = MonitorName::new(monitor_key)?;
 643                         let (_, current_monitor) = self.read_monitor(&monitor_name)?;
 644                         let updates = self
 645                                 .kv_store
 646                                 .list(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str())?;
 647                         for update in updates {
 648                                 let update_name = UpdateName::new(update)?;
 649                                 // if the update_id is lower than the stored monitor, delete
 650                                 if update_name.0 <= current_monitor.get_latest_update_id() {
 651                                         self.kv_store.remove(
 652                                                 CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 653                                                 monitor_name.as_str(),
 654                                                 update_name.as_str(),
 655                                                 lazy,
 656                                         )?;
 657                                 }
 658                         }
 659                 }
 660                 Ok(())
 661         }
 662 }
 663
 664 impl<ChannelSigner: WriteableEcdsaChannelSigner, K: Deref, L: Deref, ES: Deref, SP: Deref>
 665         Persist<ChannelSigner> for MonitorUpdatingPersister<K, L, ES, SP>
 666 where
 667         K::Target: KVStore,
 668         L::Target: Logger,
 669         ES::Target: EntropySource + Sized,
 670         SP::Target: SignerProvider + Sized,
 671 {
 672         /// Persists a new channel. This means writing the entire monitor to the
 673         /// parametrized [`KVStore`].
 674         fn persist_new_channel(
 675                 &self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>,
 676                 _monitor_update_call_id: MonitorUpdateId,
 677         ) -> chain::ChannelMonitorUpdateStatus {
 678                 // Determine the proper key for this monitor
 679                 let monitor_name = MonitorName::from(funding_txo);
 680                 // Serialize and write the new monitor
 681                 let mut monitor_bytes = Vec::with_capacity(
 682                         MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL.len() + monitor.serialized_length(),
 683                 );
 684                 monitor_bytes.extend_from_slice(MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL);
 685                 monitor.write(&mut monitor_bytes).unwrap();
 686                 match self.kv_store.write(
 687                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 688                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 689                         monitor_name.as_str(),
 690                         &monitor_bytes,
 691                 ) {
 692                         Ok(_) => {
 693                                 chain::ChannelMonitorUpdateStatus::Completed
 694                         }
 695                         Err(e) => {
 696                                 log_error!(
 697                                         self.logger,
 698                                         "Failed to write ChannelMonitor {}/{}/{} reason: {}",
 699                                         CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
 700                                         CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
 701                                         monitor_name.as_str(),
 702                                         e
 703                                 );
 704                                 chain::ChannelMonitorUpdateStatus::UnrecoverableError
 705                         }
 706                 }
 707         }
 708
 709         /// Persists a channel update, writing only the update to the parameterized [`KVStore`] if possible.
 710         ///
 711         /// In some cases, this will forward to [`MonitorUpdatingPersister::persist_new_channel`]:
 712         ///
 713         ///   - No full monitor is found in [`KVStore`]
 714         ///   - The number of pending updates exceeds `maximum_pending_updates` as given to [`Self::new`]
 715         ///   - LDK commands re-persisting the entire monitor through this function, specifically when
 716         ///     `update` is `None`.
 717         ///   - The update is at [`CLOSED_CHANNEL_UPDATE_ID`]
 718         fn update_persisted_channel(
 719                 &self, funding_txo: OutPoint, update: Option<&ChannelMonitorUpdate>,
 720                 monitor: &ChannelMonitor<ChannelSigner>, monitor_update_call_id: MonitorUpdateId,
 721         ) -> chain::ChannelMonitorUpdateStatus {
 722                 // IMPORTANT: monitor_update_call_id: MonitorUpdateId is not to be confused with
 723                 // ChannelMonitorUpdate's update_id.
 724                 if let Some(update) = update {
 725                         if update.update_id != CLOSED_CHANNEL_UPDATE_ID
 726                                 && update.update_id % self.maximum_pending_updates != 0
 727                         {
 728                                 let monitor_name = MonitorName::from(funding_txo);
 729                                 let update_name = UpdateName::from(update.update_id);
 730                                 match self.kv_store.write(
 731                                         CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 732                                         monitor_name.as_str(),
 733                                         update_name.as_str(),
 734                                         &update.encode(),
 735                                 ) {
 736                                         Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
 737                                         Err(e) => {
 738                                                 log_error!(
 739                                                         self.logger,
 740                                                         "Failed to write ChannelMonitorUpdate {}/{}/{} reason: {}",
 741                                                         CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 742                                                         monitor_name.as_str(),
 743                                                         update_name.as_str(),
 744                                                         e
 745                                                 );
 746                                                 chain::ChannelMonitorUpdateStatus::UnrecoverableError
 747                                         }
 748                                 }
 749                         } else {
 750                                 let monitor_name = MonitorName::from(funding_txo);
 751                                 // In case of channel-close monitor update, we need to read old monitor before persisting
 752                                 // the new one in order to determine the cleanup range.
 753                                 let maybe_old_monitor = match monitor.get_latest_update_id() {
 754                                         CLOSED_CHANNEL_UPDATE_ID => self.read_monitor(&monitor_name).ok(),
 755                                         _ => None
 756                                 };
 757
 758                                 // We could write this update, but it meets criteria of our design that calls for a full monitor write.
 759                                 let monitor_update_status = self.persist_new_channel(funding_txo, monitor, monitor_update_call_id);
 760
 761                                 if let chain::ChannelMonitorUpdateStatus::Completed = monitor_update_status {
 762                                         let cleanup_range = if monitor.get_latest_update_id() == CLOSED_CHANNEL_UPDATE_ID {
 763                                                 // If there is an error while reading old monitor, we skip clean up.
 764                                                 maybe_old_monitor.map(|(_, ref old_monitor)| {
 765                                                         let start = old_monitor.get_latest_update_id();
 766                                                         // We never persist an update with update_id = CLOSED_CHANNEL_UPDATE_ID
 767                                                         let end = cmp::min(
 768                                                                 start.saturating_add(self.maximum_pending_updates),
 769                                                                 CLOSED_CHANNEL_UPDATE_ID - 1,
 770                                                         );
 771                                                         (start, end)
 772                                                 })
 773                                         } else {
 774                                                 let end = monitor.get_latest_update_id();
 775                                                 let start = end.saturating_sub(self.maximum_pending_updates);
 776                                                 Some((start, end))
 777                                         };
 778
 779                                         if let Some((start, end)) = cleanup_range {
 780                                                 self.cleanup_in_range(monitor_name, start, end);
 781                                         }
 782                                 }
 783
 784                                 monitor_update_status
 785                         }
 786                 } else {
 787                         // There is no update given, so we must persist a new monitor.
 788                         self.persist_new_channel(funding_txo, monitor, monitor_update_call_id)
 789                 }
 790         }
 791 }
 792
 793 impl<K: Deref, L: Deref, ES: Deref, SP: Deref> MonitorUpdatingPersister<K, L, ES, SP>
 794 where
 795         ES::Target: EntropySource + Sized,
 796         K::Target: KVStore,
 797         L::Target: Logger,
 798         SP::Target: SignerProvider + Sized
 799 {
 800         // Cleans up monitor updates for given monitor in range `start..=end`.
 801         fn cleanup_in_range(&self, monitor_name: MonitorName, start: u64, end: u64) {
 802                 for update_id in start..=end {
 803                         let update_name = UpdateName::from(update_id);
 804                         if let Err(e) = self.kv_store.remove(
 805                                 CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
 806                                 monitor_name.as_str(),
 807                                 update_name.as_str(),
 808                                 true,
 809                         ) {
 810                                 log_error!(
 811                                         self.logger,
 812                                         "Failed to clean up channel monitor updates for monitor {}, reason: {}",
 813                                         monitor_name.as_str(),
 814                                         e
 815                                 );
 816                         };
 817                 }
 818         }
 819 }
 820
 821 /// A struct representing a name for a monitor.
 822 #[derive(Debug)]
 823 struct MonitorName(String);
 824
 825 impl MonitorName {
 826         /// Constructs a [`MonitorName`], after verifying that an [`OutPoint`] can
 827         /// be formed from the given `name`.
 828         pub fn new(name: String) -> Result<Self, io::Error> {
 829                 MonitorName::do_try_into_outpoint(&name)?;
 830                 Ok(Self(name))
 831         }
 832         /// Convert this monitor name to a str.
 833         pub fn as_str(&self) -> &str {
 834                 &self.0
 835         }
 836         /// Attempt to form a valid [`OutPoint`] from a given name string.
 837         fn do_try_into_outpoint(name: &str) -> Result<OutPoint, io::Error> {
 838                 let mut parts = name.splitn(2, '_');
 839                 let txid = if let Some(part) = parts.next() {
 840                         Txid::from_str(part).map_err(|_| {
 841                                 io::Error::new(io::ErrorKind::InvalidData, "Invalid tx ID in stored key")
 842                         })?
 843                 } else {
 844                         return Err(io::Error::new(
 845                                 io::ErrorKind::InvalidData,
 846                                 "Stored monitor key is not a splittable string",
 847                         ));
 848                 };
 849                 let index = if let Some(part) = parts.next() {
 850                         part.parse().map_err(|_| {
 851                                 io::Error::new(io::ErrorKind::InvalidData, "Invalid tx index in stored key")
 852                         })?
 853                 } else {
 854                         return Err(io::Error::new(
 855                                 io::ErrorKind::InvalidData,
 856                                 "No tx index value found after underscore in stored key",
 857                         ));
 858                 };
 859                 Ok(OutPoint { txid, index })
 860         }
 861 }
 862
 863 impl TryFrom<&MonitorName> for OutPoint {
 864         type Error = io::Error;
 865
 866         fn try_from(value: &MonitorName) -> Result<Self, io::Error> {
 867                 MonitorName::do_try_into_outpoint(&value.0)
 868         }
 869 }
 870
 871 impl From<OutPoint> for MonitorName {
 872         fn from(value: OutPoint) -> Self {
 873                 MonitorName(format!("{}_{}", value.txid.to_string(), value.index))
 874         }
 875 }
 876
 877 /// A struct representing a name for an update.
 878 #[derive(Debug)]
 879 struct UpdateName(u64, String);
 880
 881 impl UpdateName {
 882         /// Constructs an [`UpdateName`], after verifying that an update sequence ID
 883         /// can be derived from the given `name`.
 884         pub fn new(name: String) -> Result<Self, io::Error> {
 885                 match name.parse::<u64>() {
 886                         Ok(u) => Ok(u.into()),
 887                         Err(_) => {
 888                                 Err(io::Error::new(io::ErrorKind::InvalidData, "cannot parse u64 from update name"))
 889                         }
 890                 }
 891         }
 892
 893         /// Convert this monitor update name to a &str
 894         pub fn as_str(&self) -> &str {
 895                 &self.1
 896         }
 897 }
 898
 899 impl From<u64> for UpdateName {
 900         fn from(value: u64) -> Self {
 901                 Self(value, value.to_string())
 902         }
 903 }
 904
 905 #[cfg(test)]
 906 mod tests {
 907         use super::*;
 908         use crate::chain::chainmonitor::Persist;
 909         use crate::chain::ChannelMonitorUpdateStatus;
 910         use crate::events::{ClosureReason, MessageSendEventsProvider};
 911         use crate::ln::functional_test_utils::*;
 912         use crate::util::test_utils::{self, TestLogger, TestStore};
 913         use crate::{check_added_monitors, check_closed_broadcast};
 914
 915         const EXPECTED_UPDATES_PER_PAYMENT: u64 = 5;
 916
 917         #[test]
 918         fn converts_u64_to_update_name() {
 919                 assert_eq!(UpdateName::from(0).as_str(), "0");
 920                 assert_eq!(UpdateName::from(21).as_str(), "21");
 921                 assert_eq!(UpdateName::from(u64::MAX).as_str(), "18446744073709551615");
 922         }
 923
 924         #[test]
 925         fn bad_update_name_fails() {
 926                 assert!(UpdateName::new("deadbeef".to_string()).is_err());
 927                 assert!(UpdateName::new("-1".to_string()).is_err());
 928         }
 929
 930         #[test]
 931         fn monitor_from_outpoint_works() {
 932                 let monitor_name1 = MonitorName::from(OutPoint {
 933                         txid: Txid::from_str("deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef").unwrap(),
 934                         index: 1,
 935                 });
 936                 assert_eq!(monitor_name1.as_str(), "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1");
 937
 938                 let monitor_name2 = MonitorName::from(OutPoint {
 939                         txid: Txid::from_str("f33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeef").unwrap(),
 940                         index: u16::MAX,
 941                 });
 942                 assert_eq!(monitor_name2.as_str(), "f33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeeff33dbeef_65535");
 943         }
 944
 945         #[test]
 946         fn bad_monitor_string_fails() {
 947                 assert!(MonitorName::new("deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef".to_string()).is_err());
 948                 assert!(MonitorName::new("deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_65536".to_string()).is_err());
 949                 assert!(MonitorName::new("deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_21".to_string()).is_err());
 950         }
 951
 952         // Exercise the `MonitorUpdatingPersister` with real channels and payments.
 953         #[test]
 954         fn persister_with_real_monitors() {
 955                 // This value is used later to limit how many iterations we perform.
 956                 let persister_0_max_pending_updates = 7;
 957                 // Intentionally set this to a smaller value to test a different alignment.
 958                 let persister_1_max_pending_updates = 3;
 959                 let chanmon_cfgs = create_chanmon_cfgs(4);
 960                 let persister_0 = MonitorUpdatingPersister {
 961                         kv_store: &TestStore::new(false),
 962                         logger: &TestLogger::new(),
 963                         maximum_pending_updates: persister_0_max_pending_updates,
 964                         entropy_source: &chanmon_cfgs[0].keys_manager,
 965                         signer_provider: &chanmon_cfgs[0].keys_manager,
 966                 };
 967                 let persister_1 = MonitorUpdatingPersister {
 968                         kv_store: &TestStore::new(false),
 969                         logger: &TestLogger::new(),
 970                         maximum_pending_updates: persister_1_max_pending_updates,
 971                         entropy_source: &chanmon_cfgs[1].keys_manager,
 972                         signer_provider: &chanmon_cfgs[1].keys_manager,
 973                 };
 974                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 975                 let chain_mon_0 = test_utils::TestChainMonitor::new(
 976                         Some(&chanmon_cfgs[0].chain_source),
 977                         &chanmon_cfgs[0].tx_broadcaster,
 978                         &chanmon_cfgs[0].logger,
 979                         &chanmon_cfgs[0].fee_estimator,
 980                         &persister_0,
 981                         &chanmon_cfgs[0].keys_manager,
 982                 );
 983                 let chain_mon_1 = test_utils::TestChainMonitor::new(
 984                         Some(&chanmon_cfgs[1].chain_source),
 985                         &chanmon_cfgs[1].tx_broadcaster,
 986                         &chanmon_cfgs[1].logger,
 987                         &chanmon_cfgs[1].fee_estimator,
 988                         &persister_1,
 989                         &chanmon_cfgs[1].keys_manager,
 990                 );
 991                 node_cfgs[0].chain_monitor = chain_mon_0;
 992                 node_cfgs[1].chain_monitor = chain_mon_1;
 993                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 994                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 995                 let broadcaster_0 = &chanmon_cfgs[2].tx_broadcaster;
 996                 let broadcaster_1 = &chanmon_cfgs[3].tx_broadcaster;
 997
 998                 // Check that the persisted channel data is empty before any channels are
 999                 // open.
1000                 let mut persisted_chan_data_0 = persister_0.read_all_channel_monitors_with_updates(
1001                         &broadcaster_0, &&chanmon_cfgs[0].fee_estimator).unwrap();
1002                 assert_eq!(persisted_chan_data_0.len(), 0);
1003                 let mut persisted_chan_data_1 = persister_1.read_all_channel_monitors_with_updates(
1004                         &broadcaster_1, &&chanmon_cfgs[1].fee_estimator).unwrap();
1005                 assert_eq!(persisted_chan_data_1.len(), 0);
1006
1007                 // Helper to make sure the channel is on the expected update ID.
1008                 macro_rules! check_persisted_data {
1009                         ($expected_update_id: expr) => {
1010                                 persisted_chan_data_0 = persister_0.read_all_channel_monitors_with_updates(
1011                                         &broadcaster_0, &&chanmon_cfgs[0].fee_estimator).unwrap();
1012                                 // check that we stored only one monitor
1013                                 assert_eq!(persisted_chan_data_0.len(), 1);
1014                                 for (_, mon) in persisted_chan_data_0.iter() {
1015                                         // check that when we read it, we got the right update id
1016                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
1017
1018                                         // if the CM is at consolidation threshold, ensure no updates are stored.
1019                                         let monitor_name = MonitorName::from(mon.get_funding_txo().0);
1020                                         if mon.get_latest_update_id() % persister_0_max_pending_updates == 0
1021                                                         || mon.get_latest_update_id() == CLOSED_CHANNEL_UPDATE_ID {
1022                                                 assert_eq!(
1023                                                         persister_0.kv_store.list(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
1024                                                                 monitor_name.as_str()).unwrap().len(),
1025                                                         0,
1026                                                         "updates stored when they shouldn't be in persister 0"
1027                                                 );
1028                                         }
1029                                 }
1030                                 persisted_chan_data_1 = persister_1.read_all_channel_monitors_with_updates(
1031                                         &broadcaster_1, &&chanmon_cfgs[1].fee_estimator).unwrap();
1032                                 assert_eq!(persisted_chan_data_1.len(), 1);
1033                                 for (_, mon) in persisted_chan_data_1.iter() {
1034                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
1035                                         let monitor_name = MonitorName::from(mon.get_funding_txo().0);
1036                                         // if the CM is at consolidation threshold, ensure no updates are stored.
1037                                         if mon.get_latest_update_id() % persister_1_max_pending_updates == 0
1038                                                         || mon.get_latest_update_id() == CLOSED_CHANNEL_UPDATE_ID {
1039                                                 assert_eq!(
1040                                                         persister_1.kv_store.list(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE,
1041                                                                 monitor_name.as_str()).unwrap().len(),
1042                                                         0,
1043                                                         "updates stored when they shouldn't be in persister 1"
1044                                                 );
1045                                         }
1046                                 }
1047                         };
1048                 }
1049
1050                 // Create some initial channel and check that a channel was persisted.
1051                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1);
1052                 check_persisted_data!(0);
1053
1054                 // Send a few payments and make sure the monitors are updated to the latest.
1055                 send_payment(&nodes[0], &vec![&nodes[1]][..], 8_000_000);
1056                 check_persisted_data!(EXPECTED_UPDATES_PER_PAYMENT);
1057                 send_payment(&nodes[1], &vec![&nodes[0]][..], 4_000_000);
1058                 check_persisted_data!(2 * EXPECTED_UPDATES_PER_PAYMENT);
1059
1060                 // Send a few more payments to try all the alignments of max pending updates with
1061                 // updates for a payment sent and received.
1062                 let mut sender = 0;
1063                 for i in 3..=persister_0_max_pending_updates * 2 {
1064                         let receiver;
1065                         if sender == 0 {
1066                                 sender = 1;
1067                                 receiver = 0;
1068                         } else {
1069                                 sender = 0;
1070                                 receiver = 1;
1071                         }
1072                         send_payment(&nodes[sender], &vec![&nodes[receiver]][..], 21_000);
1073                         check_persisted_data!(i * EXPECTED_UPDATES_PER_PAYMENT);
1074                 }
1075
1076                 // Force close because cooperative close doesn't result in any persisted
1077                 // updates.
1078                 nodes[0].node.force_close_broadcasting_latest_txn(&nodes[0].node.list_channels()[0].channel_id, &nodes[1].node.get_our_node_id()).unwrap();
1079
1080                 check_closed_event(&nodes[0], 1, ClosureReason::HolderForceClosed, false, &[nodes[1].node.get_our_node_id()], 100000);
1081                 check_closed_broadcast!(nodes[0], true);
1082                 check_added_monitors!(nodes[0], 1);
1083
1084                 let node_txn = nodes[0].tx_broadcaster.txn_broadcast();
1085                 assert_eq!(node_txn.len(), 1);
1086
1087                 connect_block(&nodes[1], &create_dummy_block(nodes[0].best_block_hash(), 42, vec![node_txn[0].clone(), node_txn[0].clone()]));
1088
1089                 check_closed_broadcast!(nodes[1], true);
1090                 check_closed_event(&nodes[1], 1, ClosureReason::CommitmentTxConfirmed, false, &[nodes[0].node.get_our_node_id()], 100000);
1091                 check_added_monitors!(nodes[1], 1);
1092
1093                 // Make sure everything is persisted as expected after close.
1094                 check_persisted_data!(CLOSED_CHANNEL_UPDATE_ID);
1095
1096                 // Make sure the expected number of stale updates is present.
1097                 let persisted_chan_data = persister_0.read_all_channel_monitors_with_updates(&broadcaster_0, &&chanmon_cfgs[0].fee_estimator).unwrap();
1098                 let (_, monitor) = &persisted_chan_data[0];
1099                 let monitor_name = MonitorName::from(monitor.get_funding_txo().0);
1100                 // The channel should have 0 updates, as it wrote a full monitor and consolidated.
1101                 assert_eq!(persister_0.kv_store.list(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str()).unwrap().len(), 0);
1102                 assert_eq!(persister_1.kv_store.list(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str()).unwrap().len(), 0);
1103         }
1104
1105         // Test that if the `MonitorUpdatingPersister`'s can't actually write, trying to persist a
1106         // monitor or update with it results in the persister returning an UnrecoverableError status.
1107         #[test]
1108         fn unrecoverable_error_on_write_failure() {
1109                 // Set up a dummy channel and force close. This will produce a monitor
1110                 // that we can then use to test persistence.
1111                 let chanmon_cfgs = create_chanmon_cfgs(2);
1112                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1113                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
1114                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1115                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1);
1116                 nodes[1].node.force_close_broadcasting_latest_txn(&chan.2, &nodes[0].node.get_our_node_id()).unwrap();
1117                 check_closed_event(&nodes[1], 1, ClosureReason::HolderForceClosed, false, &[nodes[0].node.get_our_node_id()], 100000);
1118                 {
1119                         let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
1120                         let update_map = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap();
1121                         let update_id = update_map.get(&added_monitors[0].1.channel_id()).unwrap();
1122                         let cmu_map = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
1123                         let cmu = &cmu_map.get(&added_monitors[0].1.channel_id()).unwrap()[0];
1124                         let test_txo = OutPoint { txid: Txid::from_str("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), index: 0 };
1125
1126                         let ro_persister = MonitorUpdatingPersister {
1127                                 kv_store: &TestStore::new(true),
1128                                 logger: &TestLogger::new(),
1129                                 maximum_pending_updates: 11,
1130                                 entropy_source: node_cfgs[0].keys_manager,
1131                                 signer_provider: node_cfgs[0].keys_manager,
1132                         };
1133                         match ro_persister.persist_new_channel(test_txo, &added_monitors[0].1, update_id.2) {
1134                                 ChannelMonitorUpdateStatus::UnrecoverableError => {
1135                                         // correct result
1136                                 }
1137                                 ChannelMonitorUpdateStatus::Completed => {
1138                                         panic!("Completed persisting new channel when shouldn't have")
1139                                 }
1140                                 ChannelMonitorUpdateStatus::InProgress => {
1141                                         panic!("Returned InProgress when shouldn't have")
1142                                 }
1143                         }
1144                         match ro_persister.update_persisted_channel(test_txo, Some(cmu), &added_monitors[0].1, update_id.2) {
1145                                 ChannelMonitorUpdateStatus::UnrecoverableError => {
1146                                         // correct result
1147                                 }
1148                                 ChannelMonitorUpdateStatus::Completed => {
1149                                         panic!("Completed persisting new channel when shouldn't have")
1150                                 }
1151                                 ChannelMonitorUpdateStatus::InProgress => {
1152                                         panic!("Returned InProgress when shouldn't have")
1153                                 }
1154                         }
1155                         added_monitors.clear();
1156                 }
1157                 nodes[1].node.get_and_clear_pending_msg_events();
1158         }
1159
1160         // Confirm that the `clean_stale_updates` function finds and deletes stale updates.
1161         #[test]
1162         fn clean_stale_updates_works() {
1163                 let test_max_pending_updates = 7;
1164                 let chanmon_cfgs = create_chanmon_cfgs(3);
1165                 let persister_0 = MonitorUpdatingPersister {
1166                         kv_store: &TestStore::new(false),
1167                         logger: &TestLogger::new(),
1168                         maximum_pending_updates: test_max_pending_updates,
1169                         entropy_source: &chanmon_cfgs[0].keys_manager,
1170                         signer_provider: &chanmon_cfgs[0].keys_manager,
1171                 };
1172                 let persister_1 = MonitorUpdatingPersister {
1173                         kv_store: &TestStore::new(false),
1174                         logger: &TestLogger::new(),
1175                         maximum_pending_updates: test_max_pending_updates,
1176                         entropy_source: &chanmon_cfgs[1].keys_manager,
1177                         signer_provider: &chanmon_cfgs[1].keys_manager,
1178                 };
1179                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1180                 let chain_mon_0 = test_utils::TestChainMonitor::new(
1181                         Some(&chanmon_cfgs[0].chain_source),
1182                         &chanmon_cfgs[0].tx_broadcaster,
1183                         &chanmon_cfgs[0].logger,
1184                         &chanmon_cfgs[0].fee_estimator,
1185                         &persister_0,
1186                         &chanmon_cfgs[0].keys_manager,
1187                 );
1188                 let chain_mon_1 = test_utils::TestChainMonitor::new(
1189                         Some(&chanmon_cfgs[1].chain_source),
1190                         &chanmon_cfgs[1].tx_broadcaster,
1191                         &chanmon_cfgs[1].logger,
1192                         &chanmon_cfgs[1].fee_estimator,
1193                         &persister_1,
1194                         &chanmon_cfgs[1].keys_manager,
1195                 );
1196                 node_cfgs[0].chain_monitor = chain_mon_0;
1197                 node_cfgs[1].chain_monitor = chain_mon_1;
1198                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
1199                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1200
1201                 let broadcaster_0 = &chanmon_cfgs[2].tx_broadcaster;
1202
1203                 // Check that the persisted channel data is empty before any channels are
1204                 // open.
1205                 let persisted_chan_data = persister_0.read_all_channel_monitors_with_updates(&broadcaster_0, &&chanmon_cfgs[0].fee_estimator).unwrap();
1206                 assert_eq!(persisted_chan_data.len(), 0);
1207
1208                 // Create some initial channel
1209                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1);
1210
1211                 // Send a few payments to advance the updates a bit
1212                 send_payment(&nodes[0], &vec![&nodes[1]][..], 8_000_000);
1213                 send_payment(&nodes[1], &vec![&nodes[0]][..], 4_000_000);
1214
1215                 // Get the monitor and make a fake stale update at update_id=1 (lowest height of an update possible)
1216                 let persisted_chan_data = persister_0.read_all_channel_monitors_with_updates(&broadcaster_0, &&chanmon_cfgs[0].fee_estimator).unwrap();
1217                 let (_, monitor) = &persisted_chan_data[0];
1218                 let monitor_name = MonitorName::from(monitor.get_funding_txo().0);
1219                 persister_0
1220                         .kv_store
1221                         .write(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str(), UpdateName::from(1).as_str(), &[0u8; 1])
1222                         .unwrap();
1223
1224                 // Do the stale update cleanup
1225                 persister_0.cleanup_stale_updates(false).unwrap();
1226
1227                 // Confirm the stale update is unreadable/gone
1228                 assert!(persister_0
1229                         .kv_store
1230                         .read(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str(), UpdateName::from(1).as_str())
1231                         .is_err());
1232
1233                 // Force close.
1234                 nodes[0].node.force_close_broadcasting_latest_txn(&nodes[0].node.list_channels()[0].channel_id, &nodes[1].node.get_our_node_id()).unwrap();
1235                 check_closed_event(&nodes[0], 1, ClosureReason::HolderForceClosed, false, &[nodes[1].node.get_our_node_id()], 100000);
1236                 check_closed_broadcast!(nodes[0], true);
1237                 check_added_monitors!(nodes[0], 1);
1238
1239                 // Write an update near u64::MAX
1240                 persister_0
1241                         .kv_store
1242                         .write(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str(), UpdateName::from(u64::MAX - 1).as_str(), &[0u8; 1])
1243                         .unwrap();
1244
1245                 // Do the stale update cleanup
1246                 persister_0.cleanup_stale_updates(false).unwrap();
1247
1248                 // Confirm the stale update is unreadable/gone
1249                 assert!(persister_0
1250                         .kv_store
1251                         .read(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str(), UpdateName::from(u64::MAX - 1).as_str())
1252                         .is_err());
1253         }
1254 }