git.bitcoin.ninja Git - rust-lightning/blob - lightning-persister/src/lib.rs

   1 //! Utilities that handle persisting Rust-Lightning data to disk via standard filesystem APIs.
   2
   3 // Prefix these with `rustdoc::` when we update our MSRV to be >= 1.52 to remove warnings.
   4 #![deny(broken_intra_doc_links)]
   5 #![deny(private_intra_doc_links)]
   6
   7 #![deny(missing_docs)]
   8
   9 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
  10
  11 #![cfg_attr(all(test, feature = "_bench_unstable"), feature(test))]
  12 #[cfg(all(test, feature = "_bench_unstable"))] extern crate test;
  13
  14 mod util;
  15
  16 extern crate lightning;
  17 extern crate bitcoin;
  18 extern crate libc;
  19
  20 use bitcoin::hash_types::{BlockHash, Txid};
  21 use bitcoin::hashes::hex::FromHex;
  22 use lightning::chain::channelmonitor::ChannelMonitor;
  23 use lightning::chain::keysinterface::{EntropySource, SignerProvider};
  24 use lightning::util::ser::{ReadableArgs, Writeable};
  25 use lightning::util::persist::KVStorePersister;
  26 use std::fs;
  27 use std::io::Cursor;
  28 use std::ops::Deref;
  29 use std::path::{Path, PathBuf};
  30
  31 /// FilesystemPersister persists channel data on disk, where each channel's
  32 /// data is stored in a file named after its funding outpoint.
  33 ///
  34 /// Warning: this module does the best it can with calls to persist data, but it
  35 /// can only guarantee that the data is passed to the drive. It is up to the
  36 /// drive manufacturers to do the actual persistence properly, which they often
  37 /// don't (especially on consumer-grade hardware). Therefore, it is up to the
  38 /// user to validate their entire storage stack, to ensure the writes are
  39 /// persistent.
  40 /// Corollary: especially when dealing with larger amounts of money, it is best
  41 /// practice to have multiple channel data backups and not rely only on one
  42 /// FilesystemPersister.
  43 pub struct FilesystemPersister {
  44         path_to_channel_data: String,
  45 }
  46
  47 impl FilesystemPersister {
  48         /// Initialize a new FilesystemPersister and set the path to the individual channels'
  49         /// files.
  50         pub fn new(path_to_channel_data: String) -> Self {
  51                 Self {
  52                         path_to_channel_data,
  53                 }
  54         }
  55
  56         /// Get the directory which was provided when this persister was initialized.
  57         pub fn get_data_dir(&self) -> String {
  58                 self.path_to_channel_data.clone()
  59         }
  60
  61         /// Read `ChannelMonitor`s from disk.
  62         pub fn read_channelmonitors<ES: Deref, SP: Deref> (
  63                 &self, entropy_source: ES, signer_provider: SP
  64         ) -> std::io::Result<Vec<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::Signer>)>>
  65                 where
  66                         ES::Target: EntropySource + Sized,
  67                         SP::Target: SignerProvider + Sized
  68         {
  69                 let mut path = PathBuf::from(&self.path_to_channel_data);
  70                 path.push("monitors");
  71                 if !Path::new(&path).exists() {
  72                         return Ok(Vec::new());
  73                 }
  74                 let mut res = Vec::new();
  75                 for file_option in fs::read_dir(path)? {
  76                         let file = file_option.unwrap();
  77                         let owned_file_name = file.file_name();
  78                         let filename = owned_file_name.to_str()
  79                                 .ok_or_else(|| std::io::Error::new(std::io::ErrorKind::InvalidData,
  80                                         "File name is not a valid utf8 string"))?;
  81                         if !filename.is_ascii() || filename.len() < 65 {
  82                                 return Err(std::io::Error::new(
  83                                         std::io::ErrorKind::InvalidData,
  84                                         "Invalid ChannelMonitor file name",
  85                                 ));
  86                         }
  87                         if filename.ends_with(".tmp") {
  88                                 // If we were in the middle of committing an new update and crashed, it should be
  89                                 // safe to ignore the update - we should never have returned to the caller and
  90                                 // irrevocably committed to the new state in any way.
  91                                 continue;
  92                         }
  93
  94                         let txid = Txid::from_hex(filename.split_at(64).0)
  95                                 .map_err(|_| std::io::Error::new(
  96                                         std::io::ErrorKind::InvalidData,
  97                                         "Invalid tx ID in filename",
  98                                 ))?;
  99
 100                         let index = filename.split_at(65).1.parse()
 101                                 .map_err(|_| std::io::Error::new(
 102                                         std::io::ErrorKind::InvalidData,
 103                                         "Invalid tx index in filename",
 104                                 ))?;
 105
 106                         let contents = fs::read(&file.path())?;
 107                         let mut buffer = Cursor::new(&contents);
 108                         match <(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::Signer>)>::read(&mut buffer, (&*entropy_source, &*signer_provider)) {
 109                                 Ok((blockhash, channel_monitor)) => {
 110                                         if channel_monitor.get_funding_txo().0.txid != txid || channel_monitor.get_funding_txo().0.index != index {
 111                                                 return Err(std::io::Error::new(std::io::ErrorKind::InvalidData,
 112                                                                                "ChannelMonitor was stored in the wrong file"));
 113                                         }
 114                                         res.push((blockhash, channel_monitor));
 115                                 }
 116                                 Err(e) => return Err(std::io::Error::new(
 117                                         std::io::ErrorKind::InvalidData,
 118                                         format!("Failed to deserialize ChannelMonitor: {}", e),
 119                                 ))
 120                         }
 121                 }
 122                 Ok(res)
 123         }
 124 }
 125
 126 impl KVStorePersister for FilesystemPersister {
 127         fn persist<W: Writeable>(&self, key: &str, object: &W) -> std::io::Result<()> {
 128                 let mut dest_file = PathBuf::from(self.path_to_channel_data.clone());
 129                 dest_file.push(key);
 130                 util::write_to_file(dest_file, object)
 131         }
 132 }
 133
 134 #[cfg(test)]
 135 mod tests {
 136         extern crate lightning;
 137         extern crate bitcoin;
 138         use crate::FilesystemPersister;
 139         use bitcoin::blockdata::block::{Block, BlockHeader};
 140         use bitcoin::hashes::hex::FromHex;
 141         use bitcoin::{Txid, TxMerkleNode};
 142         use lightning::chain::ChannelMonitorUpdateStatus;
 143         use lightning::chain::chainmonitor::Persist;
 144         use lightning::chain::transaction::OutPoint;
 145         use lightning::{check_closed_broadcast, check_closed_event, check_added_monitors};
 146         use lightning::ln::functional_test_utils::*;
 147         use lightning::util::events::{ClosureReason, MessageSendEventsProvider};
 148         use lightning::util::test_utils;
 149         use std::fs;
 150         use bitcoin::hashes::Hash;
 151         #[cfg(target_os = "windows")]
 152         use {
 153                 lightning::get_event_msg,
 154                 lightning::ln::msgs::ChannelMessageHandler,
 155         };
 156
 157         impl Drop for FilesystemPersister {
 158                 fn drop(&mut self) {
 159                         // We test for invalid directory names, so it's OK if directory removal
 160                         // fails.
 161                         match fs::remove_dir_all(&self.path_to_channel_data) {
 162                                 Err(e) => println!("Failed to remove test persister directory: {}", e),
 163                                 _ => {}
 164                         }
 165                 }
 166         }
 167
 168         #[test]
 169         fn test_if_monitors_is_not_dir() {
 170                 let persister = FilesystemPersister::new("test_monitors_is_not_dir".to_string());
 171
 172                 fs::create_dir_all(&persister.path_to_channel_data).unwrap();
 173                 let mut path = std::path::PathBuf::from(&persister.path_to_channel_data);
 174                 path.push("monitors");
 175                 fs::File::create(path).unwrap();
 176
 177                 let chanmon_cfgs = create_chanmon_cfgs(1);
 178                 let mut node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
 179                 let chain_mon_0 = test_utils::TestChainMonitor::new(Some(&chanmon_cfgs[0].chain_source), &chanmon_cfgs[0].tx_broadcaster, &chanmon_cfgs[0].logger, &chanmon_cfgs[0].fee_estimator, &persister, &node_cfgs[0].keys_manager);
 180                 node_cfgs[0].chain_monitor = chain_mon_0;
 181                 let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
 182                 let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 183
 184                 // Check that read_channelmonitors() returns error if monitors/ is not a
 185                 // directory.
 186                 assert!(persister.read_channelmonitors(nodes[0].keys_manager, nodes[0].keys_manager).is_err());
 187         }
 188
 189         // Integration-test the FilesystemPersister. Test relaying a few payments
 190         // and check that the persisted data is updated the appropriate number of
 191         // times.
 192         #[test]
 193         fn test_filesystem_persister() {
 194                 // Create the nodes, giving them FilesystemPersisters for data persisters.
 195                 let persister_0 = FilesystemPersister::new("test_filesystem_persister_0".to_string());
 196                 let persister_1 = FilesystemPersister::new("test_filesystem_persister_1".to_string());
 197                 let chanmon_cfgs = create_chanmon_cfgs(2);
 198                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 199                 let chain_mon_0 = test_utils::TestChainMonitor::new(Some(&chanmon_cfgs[0].chain_source), &chanmon_cfgs[0].tx_broadcaster, &chanmon_cfgs[0].logger, &chanmon_cfgs[0].fee_estimator, &persister_0, &node_cfgs[0].keys_manager);
 200                 let chain_mon_1 = test_utils::TestChainMonitor::new(Some(&chanmon_cfgs[1].chain_source), &chanmon_cfgs[1].tx_broadcaster, &chanmon_cfgs[1].logger, &chanmon_cfgs[1].fee_estimator, &persister_1, &node_cfgs[1].keys_manager);
 201                 node_cfgs[0].chain_monitor = chain_mon_0;
 202                 node_cfgs[1].chain_monitor = chain_mon_1;
 203                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 204                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 205
 206                 // Check that the persisted channel data is empty before any channels are
 207                 // open.
 208                 let mut persisted_chan_data_0 = persister_0.read_channelmonitors(nodes[0].keys_manager, nodes[0].keys_manager).unwrap();
 209                 assert_eq!(persisted_chan_data_0.len(), 0);
 210                 let mut persisted_chan_data_1 = persister_1.read_channelmonitors(nodes[1].keys_manager, nodes[1].keys_manager).unwrap();
 211                 assert_eq!(persisted_chan_data_1.len(), 0);
 212
 213                 // Helper to make sure the channel is on the expected update ID.
 214                 macro_rules! check_persisted_data {
 215                         ($expected_update_id: expr) => {
 216                                 persisted_chan_data_0 = persister_0.read_channelmonitors(nodes[0].keys_manager, nodes[0].keys_manager).unwrap();
 217                                 assert_eq!(persisted_chan_data_0.len(), 1);
 218                                 for (_, mon) in persisted_chan_data_0.iter() {
 219                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 220                                 }
 221                                 persisted_chan_data_1 = persister_1.read_channelmonitors(nodes[1].keys_manager, nodes[1].keys_manager).unwrap();
 222                                 assert_eq!(persisted_chan_data_1.len(), 1);
 223                                 for (_, mon) in persisted_chan_data_1.iter() {
 224                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 225                                 }
 226                         }
 227                 }
 228
 229                 // Create some initial channel and check that a channel was persisted.
 230                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1);
 231                 check_persisted_data!(0);
 232
 233                 // Send a few payments and make sure the monitors are updated to the latest.
 234                 send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000);
 235                 check_persisted_data!(5);
 236                 send_payment(&nodes[1], &vec!(&nodes[0])[..], 4000000);
 237                 check_persisted_data!(10);
 238
 239                 // Force close because cooperative close doesn't result in any persisted
 240                 // updates.
 241                 nodes[0].node.force_close_broadcasting_latest_txn(&nodes[0].node.list_channels()[0].channel_id, &nodes[1].node.get_our_node_id()).unwrap();
 242                 check_closed_event!(nodes[0], 1, ClosureReason::HolderForceClosed);
 243                 check_closed_broadcast!(nodes[0], true);
 244                 check_added_monitors!(nodes[0], 1);
 245
 246                 let node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
 247                 assert_eq!(node_txn.len(), 1);
 248
 249                 let header = BlockHeader { version: 0x20000000, prev_blockhash: nodes[0].best_block_hash(), merkle_root: TxMerkleNode::all_zeros(), time: 42, bits: 42, nonce: 42 };
 250                 connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[0].clone()]});
 251                 check_closed_broadcast!(nodes[1], true);
 252                 check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);
 253                 check_added_monitors!(nodes[1], 1);
 254
 255                 // Make sure everything is persisted as expected after close.
 256                 check_persisted_data!(11);
 257         }
 258
 259         // Test that if the persister's path to channel data is read-only, writing a
 260         // monitor to it results in the persister returning a PermanentFailure.
 261         // Windows ignores the read-only flag for folders, so this test is Unix-only.
 262         #[cfg(not(target_os = "windows"))]
 263         #[test]
 264         fn test_readonly_dir_perm_failure() {
 265                 let persister = FilesystemPersister::new("test_readonly_dir_perm_failure".to_string());
 266                 fs::create_dir_all(&persister.path_to_channel_data).unwrap();
 267
 268                 // Set up a dummy channel and force close. This will produce a monitor
 269                 // that we can then use to test persistence.
 270                 let chanmon_cfgs = create_chanmon_cfgs(2);
 271                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 272                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 273                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 274                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1);
 275                 nodes[1].node.force_close_broadcasting_latest_txn(&chan.2, &nodes[0].node.get_our_node_id()).unwrap();
 276                 check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
 277                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 278                 let update_map = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap();
 279                 let update_id = update_map.get(&added_monitors[0].0.to_channel_id()).unwrap();
 280
 281                 // Set the persister's directory to read-only, which should result in
 282                 // returning a permanent failure when we then attempt to persist a
 283                 // channel update.
 284                 let path = &persister.path_to_channel_data;
 285                 let mut perms = fs::metadata(path).unwrap().permissions();
 286                 perms.set_readonly(true);
 287                 fs::set_permissions(path, perms).unwrap();
 288
 289                 let test_txo = OutPoint {
 290                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 291                         index: 0
 292                 };
 293                 match persister.persist_new_channel(test_txo, &added_monitors[0].1, update_id.2) {
 294                         ChannelMonitorUpdateStatus::PermanentFailure => {},
 295                         _ => panic!("unexpected result from persisting new channel")
 296                 }
 297
 298                 nodes[1].node.get_and_clear_pending_msg_events();
 299                 added_monitors.clear();
 300         }
 301
 302         // Test that if a persister's directory name is invalid, monitor persistence
 303         // will fail.
 304         #[cfg(target_os = "windows")]
 305         #[test]
 306         fn test_fail_on_open() {
 307                 // Set up a dummy channel and force close. This will produce a monitor
 308                 // that we can then use to test persistence.
 309                 let chanmon_cfgs = create_chanmon_cfgs(2);
 310                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 311                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 312                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 313                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1);
 314                 nodes[1].node.force_close_broadcasting_latest_txn(&chan.2, &nodes[0].node.get_our_node_id()).unwrap();
 315                 check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
 316                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 317                 let update_map = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap();
 318                 let update_id = update_map.get(&added_monitors[0].0.to_channel_id()).unwrap();
 319
 320                 // Create the persister with an invalid directory name and test that the
 321                 // channel fails to open because the directories fail to be created. There
 322                 // don't seem to be invalid filename characters on Unix that Rust doesn't
 323                 // handle, hence why the test is Windows-only.
 324                 let persister = FilesystemPersister::new(":<>/".to_string());
 325
 326                 let test_txo = OutPoint {
 327                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 328                         index: 0
 329                 };
 330                 match persister.persist_new_channel(test_txo, &added_monitors[0].1, update_id.2) {
 331                         ChannelMonitorUpdateStatus::PermanentFailure => {},
 332                         _ => panic!("unexpected result from persisting new channel")
 333                 }
 334
 335                 nodes[1].node.get_and_clear_pending_msg_events();
 336                 added_monitors.clear();
 337         }
 338 }
 339
 340 #[cfg(all(test, feature = "_bench_unstable"))]
 341 pub mod bench {
 342         use test::Bencher;
 343
 344         #[bench]
 345         fn bench_sends(bench: &mut Bencher) {
 346                 let persister_a = super::FilesystemPersister::new("bench_filesystem_persister_a".to_string());
 347                 let persister_b = super::FilesystemPersister::new("bench_filesystem_persister_b".to_string());
 348                 lightning::ln::channelmanager::bench::bench_two_sends(bench, persister_a, persister_b);
 349         }
 350 }