--- /dev/null
+extern crate lightning;
+extern crate bitcoin;
+extern crate libc;
+
+use bitcoin::hashes::hex::ToHex;
+use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr};
+use lightning::chain::channelmonitor;
+use lightning::chain::keysinterface::ChannelKeys;
+use lightning::chain::transaction::OutPoint;
+use lightning::util::ser::{Writeable, Readable};
+use std::fs;
+use std::io::Error;
+use std::path::{Path, PathBuf};
+
+#[cfg(test)]
+use {
+ bitcoin::{BlockHash, Txid},
+ bitcoin::hashes::hex::FromHex,
+ std::collections::HashMap,
+ std::io::Cursor
+};
+
+#[cfg(not(target_os = "windows"))]
+use std::os::unix::io::AsRawFd;
+
+/// FilesystemPersister persists channel data on disk, where each channel's
+/// data is stored in a file named after its funding outpoint.
+///
+/// Warning: this module does the best it can with calls to persist data, but it
+/// can only guarantee that the data is passed to the drive. It is up to the
+/// drive manufacturers to do the actual persistence properly, which they often
+/// don't (especially on consumer-grade hardware). Therefore, it is up to the
+/// user to validate their entire storage stack, to ensure the writes are
+/// persistent.
+/// Corollary: especially when dealing with larger amounts of money, it is best
+/// practice to have multiple channel data backups and not rely only on one
+/// FilesystemPersister.
+pub struct FilesystemPersister {
+ path_to_channel_data: String,
+}
+
+trait DiskWriteable {
+ fn write(&self, writer: &mut fs::File) -> Result<(), Error>;
+}
+
+impl<ChanSigner: ChannelKeys + Writeable> DiskWriteable for ChannelMonitor<ChanSigner> {
+ fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
+ self.write_for_disk(writer)
+ }
+}
+
+impl FilesystemPersister {
+ /// Initialize a new FilesystemPersister and set the path to the individual channels'
+ /// files.
+ pub fn new(path_to_channel_data: String) -> Self {
+ return Self {
+ path_to_channel_data,
+ }
+ }
+
+ fn get_full_filepath(&self, funding_txo: OutPoint) -> String {
+ let mut path = PathBuf::from(&self.path_to_channel_data);
+ path.push(format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index));
+ path.to_str().unwrap().to_string()
+ }
+
+ // Utility to write a file to disk.
+ fn write_channel_data(&self, funding_txo: OutPoint, monitor: &dyn DiskWriteable) -> std::io::Result<()> {
+ fs::create_dir_all(&self.path_to_channel_data)?;
+ // Do a crazy dance with lots of fsync()s to be overly cautious here...
+ // We never want to end up in a state where we've lost the old data, or end up using the
+ // old data on power loss after we've returned.
+ // The way to atomically write a file on Unix platforms is:
+ // open(tmpname), write(tmpfile), fsync(tmpfile), close(tmpfile), rename(), fsync(dir)
+ let filename = self.get_full_filepath(funding_txo);
+ let tmp_filename = format!("{}.tmp", filename.clone());
+
+ {
+ // Note that going by rust-lang/rust@d602a6b, on MacOS it is only safe to use
+ // rust stdlib 1.36 or higher.
+ let mut f = fs::File::create(&tmp_filename)?;
+ monitor.write(&mut f)?;
+ f.sync_all()?;
+ }
+ fs::rename(&tmp_filename, &filename)?;
+ // Fsync the parent directory on Unix.
+ #[cfg(not(target_os = "windows"))]
+ {
+ let path = Path::new(&filename).parent().unwrap();
+ let dir_file = fs::OpenOptions::new().read(true).open(path)?;
+ unsafe { libc::fsync(dir_file.as_raw_fd()); }
+ }
+ Ok(())
+ }
+
+ #[cfg(test)]
+ fn load_channel_data<ChanSigner: ChannelKeys + Readable + Writeable>(&self) ->
+ Result<HashMap<OutPoint, ChannelMonitor<ChanSigner>>, ChannelMonitorUpdateErr> {
+ if let Err(_) = fs::create_dir_all(&self.path_to_channel_data) {
+ return Err(ChannelMonitorUpdateErr::PermanentFailure);
+ }
+ let mut res = HashMap::new();
+ for file_option in fs::read_dir(&self.path_to_channel_data).unwrap() {
+ let file = file_option.unwrap();
+ let owned_file_name = file.file_name();
+ let filename = owned_file_name.to_str();
+ if !filename.is_some() || !filename.unwrap().is_ascii() || filename.unwrap().len() < 65 {
+ return Err(ChannelMonitorUpdateErr::PermanentFailure);
+ }
+
+ let txid = Txid::from_hex(filename.unwrap().split_at(64).0);
+ if txid.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
+
+ let index = filename.unwrap().split_at(65).1.split('.').next().unwrap().parse();
+ if index.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
+
+ let contents = fs::read(&file.path());
+ if contents.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
+
+ if let Ok((_, loaded_monitor)) =
+ <(BlockHash, ChannelMonitor<ChanSigner>)>::read(&mut Cursor::new(&contents.unwrap())) {
+ res.insert(OutPoint { txid: txid.unwrap(), index: index.unwrap() }, loaded_monitor);
+ } else {
+ return Err(ChannelMonitorUpdateErr::PermanentFailure);
+ }
+ }
+ Ok(res)
+ }
+}
+
+impl<ChanSigner: ChannelKeys + Readable + Writeable + Send + Sync> channelmonitor::Persist<ChanSigner> for FilesystemPersister {
+ fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
+ self.write_channel_data(funding_txo, monitor)
+ .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
+ }
+
+ fn update_persisted_channel(&self, funding_txo: OutPoint, _update: &ChannelMonitorUpdate, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
+ self.write_channel_data(funding_txo, monitor)
+ .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
+ }
+}
+
+#[cfg(test)]
+impl Drop for FilesystemPersister {
+ fn drop(&mut self) {
+ // We test for invalid directory names, so it's OK if directory removal
+ // fails.
+ match fs::remove_dir_all(&self.path_to_channel_data) {
+ Err(e) => println!("Failed to remove test persister directory: {}", e),
+ _ => {}
+ }
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ extern crate lightning;
+ extern crate bitcoin;
+ use crate::FilesystemPersister;
+ use bitcoin::blockdata::block::{Block, BlockHeader};
+ use bitcoin::hashes::hex::FromHex;
+ use bitcoin::Txid;
+ use DiskWriteable;
+ use Error;
+ use lightning::chain::channelmonitor::{Persist, ChannelMonitorUpdateErr};
+ use lightning::chain::transaction::OutPoint;
+ use lightning::{check_closed_broadcast, check_added_monitors};
+ use lightning::ln::features::InitFeatures;
+ use lightning::ln::functional_test_utils::*;
+ use lightning::ln::msgs::ErrorAction;
+ use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
+ use lightning::util::events::{MessageSendEventsProvider, MessageSendEvent};
+ use lightning::util::ser::Writer;
+ use lightning::util::test_utils;
+ use std::fs;
+ use std::io;
+ #[cfg(target_os = "windows")]
+ use {
+ lightning::get_event_msg,
+ lightning::ln::msgs::ChannelMessageHandler,
+ };
+
+ struct TestWriteable{}
+ impl DiskWriteable for TestWriteable {
+ fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
+ writer.write_all(&[42; 1])
+ }
+ }
+
+ // Integration-test the FilesystemPersister. Test relaying a few payments
+ // and check that the persisted data is updated the appropriate number of
+ // times.
+ #[test]
+ fn test_filesystem_persister() {
+ // Create the nodes, giving them FilesystemPersisters for data persisters.
+ let persister_0 = FilesystemPersister::new("test_filesystem_persister_0".to_string());
+ let persister_1 = FilesystemPersister::new("test_filesystem_persister_1".to_string());
+ let chanmon_cfgs = create_chanmon_cfgs(2);
+ let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ 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);
+ 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[0].chain_monitor = chain_mon_0;
+ node_cfgs[1].chain_monitor = chain_mon_1;
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+ // Check that the persisted channel data is empty before any channels are
+ // open.
+ let mut persisted_chan_data_0 = persister_0.load_channel_data::<EnforcingChannelKeys>().unwrap();
+ assert_eq!(persisted_chan_data_0.keys().len(), 0);
+ let mut persisted_chan_data_1 = persister_1.load_channel_data::<EnforcingChannelKeys>().unwrap();
+ assert_eq!(persisted_chan_data_1.keys().len(), 0);
+
+ // Helper to make sure the channel is on the expected update ID.
+ macro_rules! check_persisted_data {
+ ($expected_update_id: expr) => {
+ persisted_chan_data_0 = persister_0.load_channel_data::<EnforcingChannelKeys>().unwrap();
+ assert_eq!(persisted_chan_data_0.keys().len(), 1);
+ for mon in persisted_chan_data_0.values() {
+ assert_eq!(mon.get_latest_update_id(), $expected_update_id);
+ }
+ persisted_chan_data_1 = persister_1.load_channel_data::<EnforcingChannelKeys>().unwrap();
+ assert_eq!(persisted_chan_data_1.keys().len(), 1);
+ for mon in persisted_chan_data_1.values() {
+ assert_eq!(mon.get_latest_update_id(), $expected_update_id);
+ }
+ }
+ }
+
+ // Create some initial channel and check that a channel was persisted.
+ let _ = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+ check_persisted_data!(0);
+
+ // Send a few payments and make sure the monitors are updated to the latest.
+ send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000, 8_000_000);
+ check_persisted_data!(5);
+ send_payment(&nodes[1], &vec!(&nodes[0])[..], 4000000, 4_000_000);
+ check_persisted_data!(10);
+
+ // Force close because cooperative close doesn't result in any persisted
+ // updates.
+ nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id);
+ check_closed_broadcast!(nodes[0], false);
+ check_added_monitors!(nodes[0], 1);
+
+ let node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
+ assert_eq!(node_txn.len(), 1);
+
+ let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+ connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[0].clone()]}, 1);
+ check_closed_broadcast!(nodes[1], false);
+ check_added_monitors!(nodes[1], 1);
+
+ // Make sure everything is persisted as expected after close.
+ check_persisted_data!(11);
+ }
+
+ // Test that if the persister's path to channel data is read-only, writing
+ // data to it fails. Windows ignores the read-only flag for folders, so this
+ // test is Unix-only.
+ #[cfg(not(target_os = "windows"))]
+ #[test]
+ fn test_readonly_dir() {
+ let persister = FilesystemPersister::new("test_readonly_dir_persister".to_string());
+ let test_writeable = TestWriteable{};
+ let test_txo = OutPoint {
+ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
+ index: 0
+ };
+ // Create the persister's directory and set it to read-only.
+ let path = &persister.path_to_channel_data;
+ fs::create_dir_all(path).unwrap();
+ let mut perms = fs::metadata(path).unwrap().permissions();
+ perms.set_readonly(true);
+ fs::set_permissions(path, perms).unwrap();
+ match persister.write_channel_data(test_txo, &test_writeable) {
+ Err(e) => assert_eq!(e.kind(), io::ErrorKind::PermissionDenied),
+ _ => panic!("Unexpected error message")
+ }
+ }
+
+ // Test failure to rename in the process of atomically creating a channel
+ // monitor's file. We induce this failure by making the `tmp` file a
+ // directory.
+ // Explanation: given "from" = the file being renamed, "to" = the
+ // renamee that already exists: Windows should fail because it'll fail
+ // whenever "to" is a directory, and Unix should fail because if "from" is a
+ // file, then "to" is also required to be a file.
+ #[test]
+ fn test_rename_failure() {
+ let persister = FilesystemPersister::new("test_rename_failure".to_string());
+ let test_writeable = TestWriteable{};
+ let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
+ let outp_idx = 0;
+ let test_txo = OutPoint {
+ txid: Txid::from_hex(txid_hex).unwrap(),
+ index: outp_idx,
+ };
+ // Create the channel data file and make it a directory.
+ let path = &persister.path_to_channel_data;
+ fs::create_dir_all(format!("{}/{}_{}", path, txid_hex, outp_idx)).unwrap();
+ match persister.write_channel_data(test_txo, &test_writeable) {
+ Err(e) => {
+ #[cfg(not(target_os = "windows"))]
+ assert_eq!(e.kind(), io::ErrorKind::Other);
+ #[cfg(target_os = "windows")]
+ assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
+ }
+ _ => panic!("Unexpected error message")
+ }
+ }
+
+ // Test failure to create the temporary file in the persistence process.
+ // We induce this failure by having the temp file already exist and be a
+ // directory.
+ #[test]
+ fn test_tmp_file_creation_failure() {
+ let persister = FilesystemPersister::new("test_tmp_file_creation_failure".to_string());
+ let test_writeable = TestWriteable{};
+ let txid_hex = "8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be";
+ let outp_idx = 0;
+ let test_txo = OutPoint {
+ txid: Txid::from_hex(txid_hex).unwrap(),
+ index: outp_idx,
+ };
+ // Create the tmp file and make it a directory.
+ let path = &persister.path_to_channel_data;
+ fs::create_dir_all(format!("{}/{}_{}.tmp", path, txid_hex, outp_idx)).unwrap();
+ match persister.write_channel_data(test_txo, &test_writeable) {
+ Err(e) => {
+ #[cfg(not(target_os = "windows"))]
+ assert_eq!(e.kind(), io::ErrorKind::Other);
+ #[cfg(target_os = "windows")]
+ assert_eq!(e.kind(), io::ErrorKind::PermissionDenied);
+ }
+ _ => panic!("Unexpected error message")
+ }
+ }
+
+ // Test that if the persister's path to channel data is read-only, writing a
+ // monitor to it results in the persister returning a PermanentFailure.
+ // Windows ignores the read-only flag for folders, so this test is Unix-only.
+ #[cfg(not(target_os = "windows"))]
+ #[test]
+ fn test_readonly_dir_perm_failure() {
+ let persister = FilesystemPersister::new("test_readonly_dir_perm_failure".to_string());
+ fs::create_dir_all(&persister.path_to_channel_data).unwrap();
+
+ // Set up a dummy channel and force close. This will produce a monitor
+ // that we can then use to test persistence.
+ let chanmon_cfgs = create_chanmon_cfgs(2);
+ let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+ let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+ nodes[1].node.force_close_channel(&chan.2);
+ let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
+
+ // Set the persister's directory to read-only, which should result in
+ // returning a permanent failure when we then attempt to persist a
+ // channel update.
+ let path = &persister.path_to_channel_data;
+ let mut perms = fs::metadata(path).unwrap().permissions();
+ perms.set_readonly(true);
+ fs::set_permissions(path, perms).unwrap();
+
+ let test_txo = OutPoint {
+ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
+ index: 0
+ };
+ match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
+ Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
+ _ => panic!("unexpected result from persisting new channel")
+ }
+
+ nodes[1].node.get_and_clear_pending_msg_events();
+ added_monitors.clear();
+ }
+
+ // Test that if a persister's directory name is invalid, monitor persistence
+ // will fail.
+ #[cfg(target_os = "windows")]
+ #[test]
+ fn test_fail_on_open() {
+ // Set up a dummy channel and force close. This will produce a monitor
+ // that we can then use to test persistence.
+ let chanmon_cfgs = create_chanmon_cfgs(2);
+ let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+ let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+ nodes[1].node.force_close_channel(&chan.2);
+ let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
+
+ // Create the persister with an invalid directory name and test that the
+ // channel fails to open because the directories fail to be created. There
+ // don't seem to be invalid filename characters on Unix that Rust doesn't
+ // handle, hence why the test is Windows-only.
+ let persister = FilesystemPersister::new(":<>/".to_string());
+
+ let test_txo = OutPoint {
+ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
+ index: 0
+ };
+ match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
+ Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
+ _ => panic!("unexpected result from persisting new channel")
+ }
+
+ nodes[1].node.get_and_clear_pending_msg_events();
+ added_monitors.clear();
+ }
+}
projects / rust-lightning / commitdiff