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Move ChannelMonitorUpdateErr to chain as it is a chain::Watch val
[rust-lightning] / lightning-persister / src / lib.rs
1 //! Utilities that handle persisting Rust-Lightning data to disk via standard filesystem APIs.
2
3 #![deny(broken_intra_doc_links)]
4 #![deny(missing_docs)]
5
6 #![cfg_attr(all(test, feature = "unstable"), feature(test))]
7 #[cfg(all(test, feature = "unstable"))] extern crate test;
8
9 mod util;
10
11 extern crate lightning;
12 extern crate bitcoin;
13 extern crate libc;
14
15 use bitcoin::hash_types::{BlockHash, Txid};
16 use bitcoin::hashes::hex::{FromHex, ToHex};
17 use crate::util::DiskWriteable;
18 use lightning::chain;
19 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
20 use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate};
21 use lightning::chain::chainmonitor;
22 use lightning::chain::keysinterface::{Sign, KeysInterface};
23 use lightning::chain::transaction::OutPoint;
24 use lightning::ln::channelmanager::ChannelManager;
25 use lightning::util::logger::Logger;
26 use lightning::util::ser::{ReadableArgs, Writeable};
27 use std::fs;
28 use std::io::{Cursor, Error};
29 use std::ops::Deref;
30 use std::path::{Path, PathBuf};
31
32 /// FilesystemPersister persists channel data on disk, where each channel's
33 /// data is stored in a file named after its funding outpoint.
34 ///
35 /// Warning: this module does the best it can with calls to persist data, but it
36 /// can only guarantee that the data is passed to the drive. It is up to the
37 /// drive manufacturers to do the actual persistence properly, which they often
38 /// don't (especially on consumer-grade hardware). Therefore, it is up to the
39 /// user to validate their entire storage stack, to ensure the writes are
40 /// persistent.
41 /// Corollary: especially when dealing with larger amounts of money, it is best
42 /// practice to have multiple channel data backups and not rely only on one
43 /// FilesystemPersister.
44 pub struct FilesystemPersister {
45         path_to_channel_data: String,
46 }
47
48 impl<Signer: Sign> DiskWriteable for ChannelMonitor<Signer> {
49         fn write_to_file(&self, writer: &mut fs::File) -> Result<(), Error> {
50                 self.write(writer)
51         }
52 }
53
54 impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> DiskWriteable for ChannelManager<Signer, M, T, K, F, L>
55 where
56         M::Target: chain::Watch<Signer>,
57         T::Target: BroadcasterInterface,
58         K::Target: KeysInterface<Signer=Signer>,
59         F::Target: FeeEstimator,
60         L::Target: Logger,
61 {
62         fn write_to_file(&self, writer: &mut fs::File) -> Result<(), std::io::Error> {
63                 self.write(writer)
64         }
65 }
66
67 impl FilesystemPersister {
68         /// Initialize a new FilesystemPersister and set the path to the individual channels'
69         /// files.
70         pub fn new(path_to_channel_data: String) -> Self {
71                 return Self {
72                         path_to_channel_data,
73                 }
74         }
75
76         /// Get the directory which was provided when this persister was initialized.
77         pub fn get_data_dir(&self) -> String {
78                 self.path_to_channel_data.clone()
79         }
80
81         pub(crate) fn path_to_monitor_data(&self) -> PathBuf {
82                 let mut path = PathBuf::from(self.path_to_channel_data.clone());
83                 path.push("monitors");
84                 path
85         }
86
87         /// Writes the provided `ChannelManager` to the path provided at `FilesystemPersister`
88         /// initialization, within a file called "manager".
89         pub fn persist_manager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>(
90                 data_dir: String,
91                 manager: &ChannelManager<Signer, M, T, K, F, L>
92         ) -> Result<(), std::io::Error>
93         where
94                 M::Target: chain::Watch<Signer>,
95                 T::Target: BroadcasterInterface,
96                 K::Target: KeysInterface<Signer=Signer>,
97                 F::Target: FeeEstimator,
98                 L::Target: Logger,
99         {
100                 let path = PathBuf::from(data_dir);
101                 util::write_to_file(path, "manager".to_string(), manager)
102         }
103
104         /// Read `ChannelMonitor`s from disk.
105         pub fn read_channelmonitors<Signer: Sign, K: Deref> (
106                 &self, keys_manager: K
107         ) -> Result<Vec<(BlockHash, ChannelMonitor<Signer>)>, std::io::Error>
108                 where K::Target: KeysInterface<Signer=Signer> + Sized,
109         {
110                 let path = self.path_to_monitor_data();
111                 if !Path::new(&path).exists() {
112                         return Ok(Vec::new());
113                 }
114                 let mut res = Vec::new();
115                 for file_option in fs::read_dir(path).unwrap() {
116                         let file = file_option.unwrap();
117                         let owned_file_name = file.file_name();
118                         let filename = owned_file_name.to_str();
119                         if !filename.is_some() || !filename.unwrap().is_ascii() || filename.unwrap().len() < 65 {
120                                 return Err(std::io::Error::new(
121                                         std::io::ErrorKind::InvalidData,
122                                         "Invalid ChannelMonitor file name",
123                                 ));
124                         }
125
126                         let txid = Txid::from_hex(filename.unwrap().split_at(64).0);
127                         if txid.is_err() {
128                                 return Err(std::io::Error::new(
129                                         std::io::ErrorKind::InvalidData,
130                                         "Invalid tx ID in filename",
131                                 ));
132                         }
133
134                         let index = filename.unwrap().split_at(65).1.parse();
135                         if index.is_err() {
136                                 return Err(std::io::Error::new(
137                                         std::io::ErrorKind::InvalidData,
138                                         "Invalid tx index in filename",
139                                 ));
140                         }
141
142                         let contents = fs::read(&file.path())?;
143                         let mut buffer = Cursor::new(&contents);
144                         match <(BlockHash, ChannelMonitor<Signer>)>::read(&mut buffer, &*keys_manager) {
145                                 Ok((blockhash, channel_monitor)) => {
146                                         if channel_monitor.get_funding_txo().0.txid != txid.unwrap() || channel_monitor.get_funding_txo().0.index != index.unwrap() {
147                                                 return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "ChannelMonitor was stored in the wrong file"));
148                                         }
149                                         res.push((blockhash, channel_monitor));
150                                 }
151                                 Err(e) => return Err(std::io::Error::new(
152                                         std::io::ErrorKind::InvalidData,
153                                         format!("Failed to deserialize ChannelMonitor: {}", e),
154                                 ))
155                         }
156                 }
157                 Ok(res)
158         }
159 }
160
161 impl<ChannelSigner: Sign> chainmonitor::Persist<ChannelSigner> for FilesystemPersister {
162         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>) -> Result<(), chain::ChannelMonitorUpdateErr> {
163                 let filename = format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
164                 util::write_to_file(self.path_to_monitor_data(), filename, monitor)
165                         .map_err(|_| chain::ChannelMonitorUpdateErr::PermanentFailure)
166         }
167
168         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: &ChannelMonitorUpdate, monitor: &ChannelMonitor<ChannelSigner>) -> Result<(), chain::ChannelMonitorUpdateErr> {
169                 let filename = format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
170                 util::write_to_file(self.path_to_monitor_data(), filename, monitor)
171                         .map_err(|_| chain::ChannelMonitorUpdateErr::PermanentFailure)
172         }
173 }
174
175 #[cfg(test)]
176 mod tests {
177         extern crate lightning;
178         extern crate bitcoin;
179         use crate::FilesystemPersister;
180         use bitcoin::blockdata::block::{Block, BlockHeader};
181         use bitcoin::hashes::hex::FromHex;
182         use bitcoin::Txid;
183         use lightning::chain::ChannelMonitorUpdateErr;
184         use lightning::chain::chainmonitor::Persist;
185         use lightning::chain::transaction::OutPoint;
186         use lightning::{check_closed_broadcast, check_closed_event, check_added_monitors};
187         use lightning::ln::features::InitFeatures;
188         use lightning::ln::functional_test_utils::*;
189         use lightning::ln::msgs::ErrorAction;
190         use lightning::util::events::{ClosureReason, Event, MessageSendEventsProvider, MessageSendEvent};
191         use lightning::util::test_utils;
192         use std::fs;
193         #[cfg(target_os = "windows")]
194         use {
195                 lightning::get_event_msg,
196                 lightning::ln::msgs::ChannelMessageHandler,
197         };
198
199         impl Drop for FilesystemPersister {
200                 fn drop(&mut self) {
201                         // We test for invalid directory names, so it's OK if directory removal
202                         // fails.
203                         match fs::remove_dir_all(&self.path_to_channel_data) {
204                                 Err(e) => println!("Failed to remove test persister directory: {}", e),
205                                 _ => {}
206                         }
207                 }
208         }
209
210         // Integration-test the FilesystemPersister. Test relaying a few payments
211         // and check that the persisted data is updated the appropriate number of
212         // times.
213         #[test]
214         fn test_filesystem_persister() {
215                 // Create the nodes, giving them FilesystemPersisters for data persisters.
216                 let persister_0 = FilesystemPersister::new("test_filesystem_persister_0".to_string());
217                 let persister_1 = FilesystemPersister::new("test_filesystem_persister_1".to_string());
218                 let chanmon_cfgs = create_chanmon_cfgs(2);
219                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
220                 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);
221                 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);
222                 node_cfgs[0].chain_monitor = chain_mon_0;
223                 node_cfgs[1].chain_monitor = chain_mon_1;
224                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
225                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
226
227                 // Check that the persisted channel data is empty before any channels are
228                 // open.
229                 let mut persisted_chan_data_0 = persister_0.read_channelmonitors(nodes[0].keys_manager).unwrap();
230                 assert_eq!(persisted_chan_data_0.len(), 0);
231                 let mut persisted_chan_data_1 = persister_1.read_channelmonitors(nodes[1].keys_manager).unwrap();
232                 assert_eq!(persisted_chan_data_1.len(), 0);
233
234                 // Helper to make sure the channel is on the expected update ID.
235                 macro_rules! check_persisted_data {
236                         ($expected_update_id: expr) => {
237                                 persisted_chan_data_0 = persister_0.read_channelmonitors(nodes[0].keys_manager).unwrap();
238                                 assert_eq!(persisted_chan_data_0.len(), 1);
239                                 for (_, mon) in persisted_chan_data_0.iter() {
240                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
241                                 }
242                                 persisted_chan_data_1 = persister_1.read_channelmonitors(nodes[1].keys_manager).unwrap();
243                                 assert_eq!(persisted_chan_data_1.len(), 1);
244                                 for (_, mon) in persisted_chan_data_1.iter() {
245                                         assert_eq!(mon.get_latest_update_id(), $expected_update_id);
246                                 }
247                         }
248                 }
249
250                 // Create some initial channel and check that a channel was persisted.
251                 let _ = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
252                 check_persisted_data!(0);
253
254                 // Send a few payments and make sure the monitors are updated to the latest.
255                 send_payment(&nodes[0], &vec!(&nodes[1])[..], 8000000);
256                 check_persisted_data!(5);
257                 send_payment(&nodes[1], &vec!(&nodes[0])[..], 4000000);
258                 check_persisted_data!(10);
259
260                 // Force close because cooperative close doesn't result in any persisted
261                 // updates.
262                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
263                 check_closed_event!(nodes[0], 1, ClosureReason::HolderForceClosed);
264                 check_closed_broadcast!(nodes[0], true);
265                 check_added_monitors!(nodes[0], 1);
266
267                 let node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
268                 assert_eq!(node_txn.len(), 1);
269
270                 let header = BlockHeader { version: 0x20000000, prev_blockhash: nodes[0].best_block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
271                 connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[0].clone()]});
272                 check_closed_broadcast!(nodes[1], true);
273                 check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);
274                 check_added_monitors!(nodes[1], 1);
275
276                 // Make sure everything is persisted as expected after close.
277                 check_persisted_data!(11);
278         }
279
280         // Test that if the persister's path to channel data is read-only, writing a
281         // monitor to it results in the persister returning a PermanentFailure.
282         // Windows ignores the read-only flag for folders, so this test is Unix-only.
283         #[cfg(not(target_os = "windows"))]
284         #[test]
285         fn test_readonly_dir_perm_failure() {
286                 let persister = FilesystemPersister::new("test_readonly_dir_perm_failure".to_string());
287                 fs::create_dir_all(&persister.path_to_channel_data).unwrap();
288
289                 // Set up a dummy channel and force close. This will produce a monitor
290                 // that we can then use to test persistence.
291                 let chanmon_cfgs = create_chanmon_cfgs(2);
292                 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
293                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
294                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
295                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
296                 nodes[1].node.force_close_channel(&chan.2).unwrap();
297                 check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
298                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
299
300                 // Set the persister's directory to read-only, which should result in
301                 // returning a permanent failure when we then attempt to persist a
302                 // channel update.
303                 let path = &persister.path_to_channel_data;
304                 let mut perms = fs::metadata(path).unwrap().permissions();
305                 perms.set_readonly(true);
306                 fs::set_permissions(path, perms).unwrap();
307
308                 let test_txo = OutPoint {
309                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
310                         index: 0
311                 };
312                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
313                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
314                         _ => panic!("unexpected result from persisting new channel")
315                 }
316
317                 nodes[1].node.get_and_clear_pending_msg_events();
318                 added_monitors.clear();
319         }
320
321         // Test that if a persister's directory name is invalid, monitor persistence
322         // will fail.
323         #[cfg(target_os = "windows")]
324         #[test]
325         fn test_fail_on_open() {
326                 // Set up a dummy channel and force close. This will produce a monitor
327                 // that we can then use to test persistence.
328                 let chanmon_cfgs = create_chanmon_cfgs(2);
329                 let mut node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
330                 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
331                 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
332                 let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
333                 nodes[1].node.force_close_channel(&chan.2).unwrap();
334                 check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
335                 let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
336
337                 // Create the persister with an invalid directory name and test that the
338                 // channel fails to open because the directories fail to be created. There
339                 // don't seem to be invalid filename characters on Unix that Rust doesn't
340                 // handle, hence why the test is Windows-only.
341                 let persister = FilesystemPersister::new(":<>/".to_string());
342
343                 let test_txo = OutPoint {
344                         txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(),
345                         index: 0
346                 };
347                 match persister.persist_new_channel(test_txo, &added_monitors[0].1) {
348                         Err(ChannelMonitorUpdateErr::PermanentFailure) => {},
349                         _ => panic!("unexpected result from persisting new channel")
350                 }
351
352                 nodes[1].node.get_and_clear_pending_msg_events();
353                 added_monitors.clear();
354         }
355 }
356
357 #[cfg(all(test, feature = "unstable"))]
358 pub mod bench {
359         use test::Bencher;
360
361         #[bench]
362         fn bench_sends(bench: &mut Bencher) {
363                 let persister_a = super::FilesystemPersister::new("bench_filesystem_persister_a".to_string());
364                 let persister_b = super::FilesystemPersister::new("bench_filesystem_persister_b".to_string());
365                 lightning::ln::channelmanager::bench::bench_two_sends(bench, persister_a, persister_b);
366         }
367 }