_ Git - rust-lightning/blob - lightning-persister/src/lib.rs

   1 extern crate lightning;
   2 extern crate bitcoin;
   3 extern crate libc;
   4
   5 use bitcoin::hashes::hex::ToHex;
   6 use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr};
   7 use lightning::chain::channelmonitor;
   8 use lightning::chain::keysinterface::ChannelKeys;
   9 use lightning::chain::transaction::OutPoint;
  10 use lightning::util::ser::Writeable;
  11 use std::fs;
  12 use std::io::Error;
  13 use std::path::{Path, PathBuf};
  14
  15 #[cfg(test)]
  16 use {
  17         lightning::chain::keysinterface::KeysInterface,
  18         lightning::util::ser::ReadableArgs,
  19         bitcoin::{BlockHash, Txid},
  20         bitcoin::hashes::hex::FromHex,
  21         std::collections::HashMap,
  22         std::io::Cursor
  23 };
  24
  25 #[cfg(not(target_os = "windows"))]
  26 use std::os::unix::io::AsRawFd;
  27
  28 /// FilesystemPersister persists channel data on disk, where each channel's
  29 /// data is stored in a file named after its funding outpoint.
  30 ///
  31 /// Warning: this module does the best it can with calls to persist data, but it
  32 /// can only guarantee that the data is passed to the drive. It is up to the
  33 /// drive manufacturers to do the actual persistence properly, which they often
  34 /// don't (especially on consumer-grade hardware). Therefore, it is up to the
  35 /// user to validate their entire storage stack, to ensure the writes are
  36 /// persistent.
  37 /// Corollary: especially when dealing with larger amounts of money, it is best
  38 /// practice to have multiple channel data backups and not rely only on one
  39 /// FilesystemPersister.
  40 pub struct FilesystemPersister {
  41         path_to_channel_data: String,
  42 }
  43
  44 trait DiskWriteable {
  45         fn write(&self, writer: &mut fs::File) -> Result<(), Error>;
  46 }
  47
  48 impl<ChanSigner: ChannelKeys> DiskWriteable for ChannelMonitor<ChanSigner> {
  49         fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
  50                 Writeable::write(self, writer)
  51         }
  52 }
  53
  54 impl FilesystemPersister {
  55         /// Initialize a new FilesystemPersister and set the path to the individual channels'
  56         /// files.
  57         pub fn new(path_to_channel_data: String) -> Self {
  58                 return Self {
  59                         path_to_channel_data,
  60                 }
  61         }
  62
  63         fn get_full_filepath(&self, funding_txo: OutPoint) -> String {
  64                 let mut path = PathBuf::from(&self.path_to_channel_data);
  65                 path.push(format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index));
  66                 path.to_str().unwrap().to_string()
  67         }
  68
  69         // Utility to write a file to disk.
  70         fn write_channel_data(&self, funding_txo: OutPoint, monitor: &dyn DiskWriteable) -> std::io::Result<()> {
  71                 fs::create_dir_all(&self.path_to_channel_data)?;
  72                 // Do a crazy dance with lots of fsync()s to be overly cautious here...
  73                 // We never want to end up in a state where we've lost the old data, or end up using the
  74                 // old data on power loss after we've returned.
  75                 // The way to atomically write a file on Unix platforms is:
  76                 // open(tmpname), write(tmpfile), fsync(tmpfile), close(tmpfile), rename(), fsync(dir)
  77                 let filename = self.get_full_filepath(funding_txo);
  78                 let tmp_filename = format!("{}.tmp", filename.clone());
  79
  80                 {
  81                         // Note that going by rust-lang/rust@d602a6b, on MacOS it is only safe to use
  82                         // rust stdlib 1.36 or higher.
  83                         let mut f = fs::File::create(&tmp_filename)?;
  84                         monitor.write(&mut f)?;
  85                         f.sync_all()?;
  86                 }
  87                 fs::rename(&tmp_filename, &filename)?;
  88                 // Fsync the parent directory on Unix.
  89                 #[cfg(not(target_os = "windows"))]
  90                 {
  91                         let path = Path::new(&filename).parent().unwrap();
  92                         let dir_file = fs::OpenOptions::new().read(true).open(path)?;
  93                         unsafe { libc::fsync(dir_file.as_raw_fd()); }
  94                 }
  95                 Ok(())
  96         }
  97
  98         #[cfg(test)]
  99         fn load_channel_data<Keys: KeysInterface>(&self, keys: &Keys) ->
 100                 Result<HashMap<OutPoint, ChannelMonitor<Keys::ChanKeySigner>>, ChannelMonitorUpdateErr> {
 101                 if let Err(_) = fs::create_dir_all(&self.path_to_channel_data) {
 102                         return Err(ChannelMonitorUpdateErr::PermanentFailure);
 103                 }
 104                 let mut res = HashMap::new();
 105                 for file_option in fs::read_dir(&self.path_to_channel_data).unwrap() {
 106                         let file = file_option.unwrap();
 107                         let owned_file_name = file.file_name();
 108                         let filename = owned_file_name.to_str();
 109                         if !filename.is_some() || !filename.unwrap().is_ascii() || filename.unwrap().len() < 65 {
 110                                 return Err(ChannelMonitorUpdateErr::PermanentFailure);
 111                         }
 112
 113                         let txid = Txid::from_hex(filename.unwrap().split_at(64).0);
 114                         if txid.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 115
 116                         let index = filename.unwrap().split_at(65).1.split('.').next().unwrap().parse();
 117                         if index.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 118
 119                         let contents = fs::read(&file.path());
 120                         if contents.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 121
 122                         if let Ok((_, loaded_monitor)) =
 123                                 <(BlockHash, ChannelMonitor<Keys::ChanKeySigner>)>::read(&mut Cursor::new(&contents.unwrap()), keys) {
 124                                 res.insert(OutPoint { txid: txid.unwrap(), index: index.unwrap() }, loaded_monitor);
 125                         } else {
 126                                 return Err(ChannelMonitorUpdateErr::PermanentFailure);
 127                         }
 128                 }
 129                 Ok(res)
 130         }
 131 }
 132
 133 impl<ChanSigner: ChannelKeys + Send + Sync> channelmonitor::Persist<ChanSigner> for FilesystemPersister {
 134         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 135                 self.write_channel_data(funding_txo, monitor)
 136                   .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
 137         }
 138
 139         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: &ChannelMonitorUpdate, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 140                 self.write_channel_data(funding_txo, monitor)
 141                   .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
 142         }
 143 }
 144
 145 #[cfg(test)]
 146 impl Drop for FilesystemPersister {
 147         fn drop(&mut self) {
 148                 // We test for invalid directory names, so it's OK if directory removal
 149                 // fails.
 150                 match fs::remove_dir_all(&self.path_to_channel_data) {
 151                         Err(e) => println!("Failed to remove test persister directory: {}", e),
 152                         _ => {}
 153                 }
 154         }
 155 }
 156
 157 #[cfg(test)]
 158 mod tests {
 159         extern crate lightning;
 160         extern crate bitcoin;
 161         use crate::FilesystemPersister;
 162         use bitcoin::blockdata::block::{Block, BlockHeader};
 163         use bitcoin::hashes::hex::FromHex;
 164         use bitcoin::Txid;
 165         use DiskWriteable;
 166         use Error;
 167         use lightning::chain::channelmonitor::{Persist, ChannelMonitorUpdateErr};
 168         use lightning::chain::transaction::OutPoint;
 169         use lightning::{check_closed_broadcast, check_added_monitors};
 170         use lightning::ln::features::InitFeatures;
 171         use lightning::ln::functional_test_utils::*;
 172         use lightning::ln::msgs::ErrorAction;
 173         use lightning::util::events::{MessageSendEventsProvider, MessageSendEvent};
 174         use lightning::util::ser::Writer;
 175         use lightning::util::test_utils;
 176         use std::fs;
 177         use std::io;
 178         #[cfg(target_os = "windows")]
 179         use {
 180                 lightning::get_event_msg,
 181                 lightning::ln::msgs::ChannelMessageHandler,
 182         };
 183
 184         struct TestWriteable{}
 185         impl DiskWriteable for TestWriteable {
 186                 fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
 187                         writer.write_all(&[42; 1])
 188                 }
 189         }
 190
 191         // Integration-test the FilesystemPersister. Test relaying a few payments
 192         // and check that the persisted data is updated the appropriate number of
 193         // times.
 194         #[test]
 195         fn test_filesystem_persister() {
 196                 // Create the nodes, giving them FilesystemPersisters for data persisters.
 197                 let persister_0 = FilesystemPersister::new("test_filesystem_persister_0".to_string());
 198                 let persister_1 = FilesystemPersister::new("test_filesystem_persister_1".to_string());
 199                 let chanmon_cfgs = create_chanmon_cfgs(2);
 200                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 201                 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);
 202                 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);
 203                 node_cfgs[0].chain_monitor = chain_mon_0;
 204                 node_cfgs[1].chain_monitor = chain_mon_1;
 205                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 206                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 207
 208                 // Check that the persisted channel data is empty before any channels are
 209                 // open.
 210                 let mut persisted_chan_data_0 = persister_0.load_channel_data(nodes[0].keys_manager).unwrap();
 211                 assert_eq!(persisted_chan_data_0.keys().len(), 0);
 212                 let mut persisted_chan_data_1 = persister_1.load_channel_data(nodes[1].keys_manager).unwrap();
 213                 assert_eq!(persisted_chan_data_1.keys().len(), 0);
 214
 215                 // Helper to make sure the channel is on the expected update ID.
 216                 macro_rules! check_persisted_data {
 217                         ($expected_update_id: expr) => {
 218                                 persisted_chan_data_0 = persister_0.load_channel_data(nodes[0].keys_manager).unwrap();
 219                                 assert_eq!(persisted_chan_data_0.keys().len(), 1);
 220                                 for mon in persisted_chan_data_0.values() {
 221                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 222                                 }
 223                                 persisted_chan_data_1 = persister_1.load_channel_data(nodes[1].keys_manager).unwrap();
 224                                 assert_eq!(persisted_chan_data_1.keys().len(), 1);
 225                                 for mon in persisted_chan_data_1.values() {
 226                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 227                                 }
 228                         }
 229                 }
 230
 231                 // Create some initial channel and check that a channel was persisted.
 232                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 233                 check_persisted_data!(0);
 234
 235                 // Send a few payments and make sure the monitors are updated to the latest.
 236                 send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000, 8_000_000);
 237                 check_persisted_data!(5);
 238                 send_payment(&nodes[1], &vec!(&nodes[0])[..], 4000000, 4_000_000);
 239                 check_persisted_data!(10);
 240
 241                 // Force close because cooperative close doesn't result in any persisted
 242                 // updates.
 243                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
 244                 check_closed_broadcast!(nodes[0], false);
 245                 check_added_monitors!(nodes[0], 1);
 246
 247                 let node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
 248                 assert_eq!(node_txn.len(), 1);
 249
 250                 let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
 251                 connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[0].clone()]}, 1);
 252                 check_closed_broadcast!(nodes[1], false);
 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
 260         // data to it fails. Windows ignores the read-only flag for folders, so this
 261         // test is Unix-only.
 262         #[cfg(not(target_os = "windows"))]
 263         #[test]
 264         fn test_readonly_dir() {
 265                 let persister = FilesystemPersister::new("test_readonly_dir_persister".to_string());
 266                 let test_writeable = TestWriteable{};
 267                 let test_txo = OutPoint {
 268                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 269                         index: 0
 270                 };
 271                 // Create the persister's directory and set it to read-only.
 272                 let path = &persister.path_to_channel_data;
 273                 fs::create_dir_all(path).unwrap();
 274                 let mut perms = fs::metadata(path).unwrap().permissions();
 275                 perms.set_readonly(true);
 276                 fs::set_permissions(path, perms).unwrap();
 277                 match persister.write_channel_data(test_txo, &test_writeable) {
 278                         Err(e) => assert_eq!(e.kind(), io::ErrorKind::PermissionDenied),
 279                         _ => panic!("Unexpected error message")
 280                 }
 281         }
 282
 283         // Test failure to rename in the process of atomically creating a channel
 284         // monitor's file. We induce this failure by making the `tmp` file a
 285         // directory.
 286         // Explanation: given "from" = the file being renamed, "to" = the
 287         // renamee that already exists: Windows should fail because it'll fail
 288         // whenever "to" is a directory, and Unix should fail because if "from" is a
 289         // file, then "to" is also required to be a file.
 290         #[test]
 291         fn test_rename_failure() {
 292                 let persister = FilesystemPersister::new("test_rename_failure".to_string());
 293                 let test_writeable = TestWriteable{};
 294                 let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
 295                 let outp_idx = 0;
 296                 let test_txo = OutPoint {
 297                         txid: Txid::from_hex(txid_hex).unwrap(),
 298                         index: outp_idx,
 299                 };
 300                 // Create the channel data file and make it a directory.
 301                 let path = &persister.path_to_channel_data;
 302                 fs::create_dir_all(format!("{}/{}_{}", path, txid_hex, outp_idx)).unwrap();
 303                 match persister.write_channel_data(test_txo, &test_writeable) {
 304                         Err(e) => {
 305                                 #[cfg(not(target_os = "windows"))]
 306                                 assert_eq!(e.kind(), io::ErrorKind::Other);
 307                                 #[cfg(target_os = "windows")]
 308                                 assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
 309                         }
 310                         _ => panic!("Unexpected error message")
 311                 }
 312         }
 313
 314         // Test failure to create the temporary file in the persistence process.
 315         // We induce this failure by having the temp file already exist and be a
 316         // directory.
 317         #[test]
 318         fn test_tmp_file_creation_failure() {
 319                 let persister = FilesystemPersister::new("test_tmp_file_creation_failure".to_string());
 320                 let test_writeable = TestWriteable{};
 321                 let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
 322                 let outp_idx = 0;
 323                 let test_txo = OutPoint {
 324                         txid: Txid::from_hex(txid_hex).unwrap(),
 325                         index: outp_idx,
 326                 };
 327                 // Create the tmp file and make it a directory.
 328                 let path = &persister.path_to_channel_data;
 329                 fs::create_dir_all(format!("{}/{}_{}.tmp", path, txid_hex, outp_idx)).unwrap();
 330                 match persister.write_channel_data(test_txo, &test_writeable) {
 331                         Err(e) => {
 332                                 #[cfg(not(target_os = "windows"))]
 333                                 assert_eq!(e.kind(), io::ErrorKind::Other);
 334                                 #[cfg(target_os = "windows")]
 335                                 assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
 336                         }
 337                         _ => panic!("Unexpected error message")
 338                 }
 339         }
 340
 341         // Test that if the persister's path to channel data is read-only, writing a
 342         // monitor to it results in the persister returning a PermanentFailure.
 343         // Windows ignores the read-only flag for folders, so this test is Unix-only.
 344         #[cfg(not(target_os = "windows"))]
 345         #[test]
 346         fn test_readonly_dir_perm_failure() {
 347                 let persister = FilesystemPersister::new("test_readonly_dir_perm_failure".to_string());
 348                 fs::create_dir_all(&persister.path_to_channel_data).unwrap();
 349
 350                 // Set up a dummy channel and force close. This will produce a monitor
 351                 // that we can then use to test persistence.
 352                 let chanmon_cfgs = create_chanmon_cfgs(2);
 353                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 354                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 355                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 356                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 357                 nodes[1].node.force_close_channel(&chan.2).unwrap();
 358                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 359
 360                 // Set the persister's directory to read-only, which should result in
 361                 // returning a permanent failure when we then attempt to persist a
 362                 // channel update.
 363                 let path = &persister.path_to_channel_data;
 364                 let mut perms = fs::metadata(path).unwrap().permissions();
 365                 perms.set_readonly(true);
 366                 fs::set_permissions(path, perms).unwrap();
 367
 368                 let test_txo = OutPoint {
 369                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 370                         index: 0
 371                 };
 372                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
 373                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
 374                         _ => panic!("unexpected result from persisting new channel")
 375                 }
 376
 377                 nodes[1].node.get_and_clear_pending_msg_events();
 378                 added_monitors.clear();
 379         }
 380
 381         // Test that if a persister's directory name is invalid, monitor persistence
 382         // will fail.
 383         #[cfg(target_os = "windows")]
 384         #[test]
 385         fn test_fail_on_open() {
 386                 // Set up a dummy channel and force close. This will produce a monitor
 387                 // that we can then use to test persistence.
 388                 let chanmon_cfgs = create_chanmon_cfgs(2);
 389                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 390                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 391                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 392                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 393                 nodes[1].node.force_close_channel(&chan.2).unwrap();
 394                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 395
 396                 // Create the persister with an invalid directory name and test that the
 397                 // channel fails to open because the directories fail to be created. There
 398                 // don't seem to be invalid filename characters on Unix that Rust doesn't
 399                 // handle, hence why the test is Windows-only.
 400                 let persister = FilesystemPersister::new(":<>/".to_string());
 401
 402                 let test_txo = OutPoint {
 403                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 404                         index: 0
 405                 };
 406                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
 407                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
 408                         _ => panic!("unexpected result from persisting new channel")
 409                 }
 410
 411                 nodes[1].node.get_and_clear_pending_msg_events();
 412                 added_monitors.clear();
 413         }
 414 }