_ 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, Readable};
  11 use std::fs;
  12 use std::io::Error;
  13 use std::path::{Path, PathBuf};
  14
  15 #[cfg(test)]
  16 use {
  17         bitcoin::{BlockHash, Txid},
  18         bitcoin::hashes::hex::FromHex,
  19         std::collections::HashMap,
  20         std::io::Cursor
  21 };
  22
  23 #[cfg(not(target_os = "windows"))]
  24 use std::os::unix::io::AsRawFd;
  25
  26 /// FilesystemPersister persists channel data on disk, where each channel's
  27 /// data is stored in a file named after its funding outpoint.
  28 ///
  29 /// Warning: this module does the best it can with calls to persist data, but it
  30 /// can only guarantee that the data is passed to the drive. It is up to the
  31 /// drive manufacturers to do the actual persistence properly, which they often
  32 /// don't (especially on consumer-grade hardware). Therefore, it is up to the
  33 /// user to validate their entire storage stack, to ensure the writes are
  34 /// persistent.
  35 /// Corollary: especially when dealing with larger amounts of money, it is best
  36 /// practice to have multiple channel data backups and not rely only on one
  37 /// FilesystemPersister.
  38 pub struct FilesystemPersister {
  39         path_to_channel_data: String,
  40 }
  41
  42 trait DiskWriteable {
  43         fn write(&self, writer: &mut fs::File) -> Result<(), Error>;
  44 }
  45
  46 impl<ChanSigner: ChannelKeys + Writeable> DiskWriteable for ChannelMonitor<ChanSigner> {
  47         fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
  48                 self.serialize_for_disk(writer)
  49         }
  50 }
  51
  52 impl FilesystemPersister {
  53         /// Initialize a new FilesystemPersister and set the path to the individual channels'
  54         /// files.
  55         pub fn new(path_to_channel_data: String) -> Self {
  56                 return Self {
  57                         path_to_channel_data,
  58                 }
  59         }
  60
  61         fn get_full_filepath(&self, funding_txo: OutPoint) -> String {
  62                 let mut path = PathBuf::from(&self.path_to_channel_data);
  63                 path.push(format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index));
  64                 path.to_str().unwrap().to_string()
  65         }
  66
  67         // Utility to write a file to disk.
  68         fn write_channel_data(&self, funding_txo: OutPoint, monitor: &dyn DiskWriteable) -> std::io::Result<()> {
  69                 fs::create_dir_all(&self.path_to_channel_data)?;
  70                 // Do a crazy dance with lots of fsync()s to be overly cautious here...
  71                 // We never want to end up in a state where we've lost the old data, or end up using the
  72                 // old data on power loss after we've returned.
  73                 // The way to atomically write a file on Unix platforms is:
  74                 // open(tmpname), write(tmpfile), fsync(tmpfile), close(tmpfile), rename(), fsync(dir)
  75                 let filename = self.get_full_filepath(funding_txo);
  76                 let tmp_filename = format!("{}.tmp", filename.clone());
  77
  78                 {
  79                         // Note that going by rust-lang/rust@d602a6b, on MacOS it is only safe to use
  80                         // rust stdlib 1.36 or higher.
  81                         let mut f = fs::File::create(&tmp_filename)?;
  82                         monitor.write(&mut f)?;
  83                         f.sync_all()?;
  84                 }
  85                 fs::rename(&tmp_filename, &filename)?;
  86                 // Fsync the parent directory on Unix.
  87                 #[cfg(not(target_os = "windows"))]
  88                 {
  89                         let path = Path::new(&filename).parent().unwrap();
  90                         let dir_file = fs::OpenOptions::new().read(true).open(path)?;
  91                         unsafe { libc::fsync(dir_file.as_raw_fd()); }
  92                 }
  93                 Ok(())
  94         }
  95
  96         #[cfg(test)]
  97         fn load_channel_data<ChanSigner: ChannelKeys + Readable + Writeable>(&self) ->
  98                 Result<HashMap<OutPoint, ChannelMonitor<ChanSigner>>, ChannelMonitorUpdateErr> {
  99                 if let Err(_) = fs::create_dir_all(&self.path_to_channel_data) {
 100                         return Err(ChannelMonitorUpdateErr::PermanentFailure);
 101                 }
 102                 let mut res = HashMap::new();
 103                 for file_option in fs::read_dir(&self.path_to_channel_data).unwrap() {
 104                         let file = file_option.unwrap();
 105                         let owned_file_name = file.file_name();
 106                         let filename = owned_file_name.to_str();
 107                         if !filename.is_some() || !filename.unwrap().is_ascii() || filename.unwrap().len() < 65 {
 108                                 return Err(ChannelMonitorUpdateErr::PermanentFailure);
 109                         }
 110
 111                         let txid = Txid::from_hex(filename.unwrap().split_at(64).0);
 112                         if txid.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 113
 114                         let index = filename.unwrap().split_at(65).1.split('.').next().unwrap().parse();
 115                         if index.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 116
 117                         let contents = fs::read(&file.path());
 118                         if contents.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
 119
 120                         if let Ok((_, loaded_monitor)) =
 121                                 <(BlockHash, ChannelMonitor<ChanSigner>)>::read(&mut Cursor::new(&contents.unwrap())) {
 122                                 res.insert(OutPoint { txid: txid.unwrap(), index: index.unwrap() }, loaded_monitor);
 123                         } else {
 124                                 return Err(ChannelMonitorUpdateErr::PermanentFailure);
 125                         }
 126                 }
 127                 Ok(res)
 128         }
 129 }
 130
 131 impl<ChanSigner: ChannelKeys + Readable + Writeable + Send + Sync> channelmonitor::Persist<ChanSigner> for FilesystemPersister {
 132         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 133                 self.write_channel_data(funding_txo, monitor)
 134                   .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
 135         }
 136
 137         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: &ChannelMonitorUpdate, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 138                 self.write_channel_data(funding_txo, monitor)
 139                   .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
 140         }
 141 }
 142
 143 #[cfg(test)]
 144 impl Drop for FilesystemPersister {
 145         fn drop(&mut self) {
 146                 // We test for invalid directory names, so it's OK if directory removal
 147                 // fails.
 148                 match fs::remove_dir_all(&self.path_to_channel_data) {
 149                         Err(e) => println!("Failed to remove test persister directory: {}", e),
 150                         _ => {}
 151                 }
 152         }
 153 }
 154
 155 #[cfg(test)]
 156 mod tests {
 157         extern crate lightning;
 158         extern crate bitcoin;
 159         use crate::FilesystemPersister;
 160         use bitcoin::blockdata::block::{Block, BlockHeader};
 161         use bitcoin::hashes::hex::FromHex;
 162         use bitcoin::Txid;
 163         use DiskWriteable;
 164         use Error;
 165         use lightning::chain::channelmonitor::{Persist, ChannelMonitorUpdateErr};
 166         use lightning::chain::transaction::OutPoint;
 167         use lightning::{check_closed_broadcast, check_added_monitors};
 168         use lightning::ln::features::InitFeatures;
 169         use lightning::ln::functional_test_utils::*;
 170         use lightning::ln::msgs::ErrorAction;
 171         use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
 172         use lightning::util::events::{MessageSendEventsProvider, MessageSendEvent};
 173         use lightning::util::ser::Writer;
 174         use lightning::util::test_utils;
 175         use std::fs;
 176         use std::io;
 177         #[cfg(target_os = "windows")]
 178         use {
 179                 lightning::get_event_msg,
 180                 lightning::ln::msgs::ChannelMessageHandler,
 181         };
 182
 183         struct TestWriteable{}
 184         impl DiskWriteable for TestWriteable {
 185                 fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
 186                         writer.write_all(&[42; 1])
 187                 }
 188         }
 189
 190         // Integration-test the FilesystemPersister. Test relaying a few payments
 191         // and check that the persisted data is updated the appropriate number of
 192         // times.
 193         #[test]
 194         fn test_filesystem_persister() {
 195                 // Create the nodes, giving them FilesystemPersisters for data persisters.
 196                 let persister_0 = FilesystemPersister::new("test_filesystem_persister_0".to_string());
 197                 let persister_1 = FilesystemPersister::new("test_filesystem_persister_1".to_string());
 198                 let chanmon_cfgs = create_chanmon_cfgs(2);
 199                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 200                 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);
 201                 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);
 202                 node_cfgs[0].chain_monitor = chain_mon_0;
 203                 node_cfgs[1].chain_monitor = chain_mon_1;
 204                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 205                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 206
 207                 // Check that the persisted channel data is empty before any channels are
 208                 // open.
 209                 let mut persisted_chan_data_0 = persister_0.load_channel_data::<EnforcingChannelKeys>().unwrap();
 210                 assert_eq!(persisted_chan_data_0.keys().len(), 0);
 211                 let mut persisted_chan_data_1 = persister_1.load_channel_data::<EnforcingChannelKeys>().unwrap();
 212                 assert_eq!(persisted_chan_data_1.keys().len(), 0);
 213
 214                 // Helper to make sure the channel is on the expected update ID.
 215                 macro_rules! check_persisted_data {
 216                         ($expected_update_id: expr) => {
 217                                 persisted_chan_data_0 = persister_0.load_channel_data::<EnforcingChannelKeys>().unwrap();
 218                                 assert_eq!(persisted_chan_data_0.keys().len(), 1);
 219                                 for mon in persisted_chan_data_0.values() {
 220                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 221                                 }
 222                                 persisted_chan_data_1 = persister_1.load_channel_data::<EnforcingChannelKeys>().unwrap();
 223                                 assert_eq!(persisted_chan_data_1.keys().len(), 1);
 224                                 for mon in persisted_chan_data_1.values() {
 225                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
 226                                 }
 227                         }
 228                 }
 229
 230                 // Create some initial channel and check that a channel was persisted.
 231                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 232                 check_persisted_data!(0);
 233
 234                 // Send a few payments and make sure the monitors are updated to the latest.
 235                 send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000, 8_000_000);
 236                 check_persisted_data!(5);
 237                 send_payment(&nodes[1], &vec!(&nodes[0])[..], 4000000, 4_000_000);
 238                 check_persisted_data!(10);
 239
 240                 // Force close because cooperative close doesn't result in any persisted
 241                 // updates.
 242                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id);
 243                 check_closed_broadcast!(nodes[0], false);
 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: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
 250                 connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[0].clone()]}, 1);
 251                 check_closed_broadcast!(nodes[1], false);
 252                 check_added_monitors!(nodes[1], 1);
 253
 254                 // Make sure everything is persisted as expected after close.
 255                 check_persisted_data!(11);
 256         }
 257
 258         // Test that if the persister's path to channel data is read-only, writing
 259         // data to it fails. Windows ignores the read-only flag for folders, so this
 260         // test is Unix-only.
 261         #[cfg(not(target_os = "windows"))]
 262         #[test]
 263         fn test_readonly_dir() {
 264                 let persister = FilesystemPersister::new("test_readonly_dir_persister".to_string());
 265                 let test_writeable = TestWriteable{};
 266                 let test_txo = OutPoint {
 267                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 268                         index: 0
 269                 };
 270                 // Create the persister's directory and set it to read-only.
 271                 let path = &persister.path_to_channel_data;
 272                 fs::create_dir_all(path).unwrap();
 273                 let mut perms = fs::metadata(path).unwrap().permissions();
 274                 perms.set_readonly(true);
 275                 fs::set_permissions(path, perms).unwrap();
 276                 match persister.write_channel_data(test_txo, &test_writeable) {
 277                         Err(e) => assert_eq!(e.kind(), io::ErrorKind::PermissionDenied),
 278                         _ => panic!("Unexpected error message")
 279                 }
 280         }
 281
 282         // Test failure to rename in the process of atomically creating a channel
 283         // monitor's file. We induce this failure by making the `tmp` file a
 284         // directory.
 285         // Explanation: given "from" = the file being renamed, "to" = the
 286         // renamee that already exists: Windows should fail because it'll fail
 287         // whenever "to" is a directory, and Unix should fail because if "from" is a
 288         // file, then "to" is also required to be a file.
 289         #[test]
 290         fn test_rename_failure() {
 291                 let persister = FilesystemPersister::new("test_rename_failure".to_string());
 292                 let test_writeable = TestWriteable{};
 293                 let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
 294                 let outp_idx = 0;
 295                 let test_txo = OutPoint {
 296                         txid: Txid::from_hex(txid_hex).unwrap(),
 297                         index: outp_idx,
 298                 };
 299                 // Create the channel data file and make it a directory.
 300                 let path = &persister.path_to_channel_data;
 301                 fs::create_dir_all(format!("{}/{}_{}", path, txid_hex, outp_idx)).unwrap();
 302                 match persister.write_channel_data(test_txo, &test_writeable) {
 303                         Err(e) => {
 304                                 #[cfg(not(target_os = "windows"))]
 305                                 assert_eq!(e.kind(), io::ErrorKind::Other);
 306                                 #[cfg(target_os = "windows")]
 307                                 assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
 308                         }
 309                         _ => panic!("Unexpected error message")
 310                 }
 311         }
 312
 313         // Test failure to create the temporary file in the persistence process.
 314         // We induce this failure by having the temp file already exist and be a
 315         // directory.
 316         #[test]
 317         fn test_tmp_file_creation_failure() {
 318                 let persister = FilesystemPersister::new("test_tmp_file_creation_failure".to_string());
 319                 let test_writeable = TestWriteable{};
 320                 let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
 321                 let outp_idx = 0;
 322                 let test_txo = OutPoint {
 323                         txid: Txid::from_hex(txid_hex).unwrap(),
 324                         index: outp_idx,
 325                 };
 326                 // Create the tmp file and make it a directory.
 327                 let path = &persister.path_to_channel_data;
 328                 fs::create_dir_all(format!("{}/{}_{}.tmp", path, txid_hex, outp_idx)).unwrap();
 329                 match persister.write_channel_data(test_txo, &test_writeable) {
 330                         Err(e) => {
 331                                 #[cfg(not(target_os = "windows"))]
 332                                 assert_eq!(e.kind(), io::ErrorKind::Other);
 333                                 #[cfg(target_os = "windows")]
 334                                 assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
 335                         }
 336                         _ => panic!("Unexpected error message")
 337                 }
 338         }
 339
 340         // Test that if the persister's path to channel data is read-only, writing a
 341         // monitor to it results in the persister returning a PermanentFailure.
 342         // Windows ignores the read-only flag for folders, so this test is Unix-only.
 343         #[cfg(not(target_os = "windows"))]
 344         #[test]
 345         fn test_readonly_dir_perm_failure() {
 346                 let persister = FilesystemPersister::new("test_readonly_dir_perm_failure".to_string());
 347                 fs::create_dir_all(&persister.path_to_channel_data).unwrap();
 348
 349                 // Set up a dummy channel and force close. This will produce a monitor
 350                 // that we can then use to test persistence.
 351                 let chanmon_cfgs = create_chanmon_cfgs(2);
 352                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 353                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 354                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 355                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 356                 nodes[1].node.force_close_channel(&chan.2);
 357                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 358
 359                 // Set the persister's directory to read-only, which should result in
 360                 // returning a permanent failure when we then attempt to persist a
 361                 // channel update.
 362                 let path = &persister.path_to_channel_data;
 363                 let mut perms = fs::metadata(path).unwrap().permissions();
 364                 perms.set_readonly(true);
 365                 fs::set_permissions(path, perms).unwrap();
 366
 367                 let test_txo = OutPoint {
 368                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 369                         index: 0
 370                 };
 371                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
 372                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
 373                         _ => panic!("unexpected result from persisting new channel")
 374                 }
 375
 376                 nodes[1].node.get_and_clear_pending_msg_events();
 377                 added_monitors.clear();
 378         }
 379
 380         // Test that if a persister's directory name is invalid, monitor persistence
 381         // will fail.
 382         #[cfg(target_os = "windows")]
 383         #[test]
 384         fn test_fail_on_open() {
 385                 // Set up a dummy channel and force close. This will produce a monitor
 386                 // that we can then use to test persistence.
 387                 let chanmon_cfgs = create_chanmon_cfgs(2);
 388                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 389                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 390                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 391                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 392                 nodes[1].node.force_close_channel(&chan.2);
 393                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
 394
 395                 // Create the persister with an invalid directory name and test that the
 396                 // channel fails to open because the directories fail to be created. There
 397                 // don't seem to be invalid filename characters on Unix that Rust doesn't
 398                 // handle, hence why the test is Windows-only.
 399                 let persister = FilesystemPersister::new(":<>/".to_string());
 400
 401                 let test_txo = OutPoint {
 402                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
 403                         index: 0
 404                 };
 405                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
 406                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
 407                         _ => panic!("unexpected result from persisting new channel")
 408                 }
 409
 410                 nodes[1].node.get_and_clear_pending_msg_events();
 411                 added_monitors.clear();
 412         }
 413 }