_ Git - ldk-sample/blob - src/main.rs

   1 pub mod bitcoind_client;
   2 mod cli;
   3 mod convert;
   4 mod disk;
   5 mod hex_utils;
   6
   7 use crate::bitcoind_client::BitcoindClient;
   8 use crate::disk::FilesystemLogger;
   9 use bitcoin::blockdata::constants::genesis_block;
  10 use bitcoin::blockdata::transaction::Transaction;
  11 use bitcoin::consensus::encode;
  12 use bitcoin::hashes::sha256::Hash as Sha256;
  13 use bitcoin::hashes::Hash;
  14 use bitcoin::network::constants::Network;
  15 use bitcoin::secp256k1::Secp256k1;
  16 use bitcoin::BlockHash;
  17 use bitcoin_bech32::WitnessProgram;
  18 use lightning::chain;
  19 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
  20 use lightning::chain::chainmonitor;
  21 use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
  22 use lightning::chain::{BestBlock, Filter, Watch};
  23 use lightning::ln::channelmanager;
  24 use lightning::ln::channelmanager::{
  25         ChainParameters, ChannelManagerReadArgs, SimpleArcChannelManager,
  26 };
  27 use lightning::ln::peer_handler::{IgnoringMessageHandler, MessageHandler, SimpleArcPeerManager};
  28 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
  29 use lightning::routing::network_graph::NetGraphMsgHandler;
  30 use lightning::util::config::UserConfig;
  31 use lightning::util::events::{Event, PaymentPurpose};
  32 use lightning::util::ser::ReadableArgs;
  33 use lightning_background_processor::BackgroundProcessor;
  34 use lightning_block_sync::init;
  35 use lightning_block_sync::poll;
  36 use lightning_block_sync::SpvClient;
  37 use lightning_block_sync::UnboundedCache;
  38 use lightning_net_tokio::SocketDescriptor;
  39 use lightning_persister::FilesystemPersister;
  40 use rand::{thread_rng, Rng};
  41 use std::collections::hash_map::Entry;
  42 use std::collections::HashMap;
  43 use std::fmt;
  44 use std::fs;
  45 use std::fs::File;
  46 use std::io;
  47 use std::io::Write;
  48 use std::ops::Deref;
  49 use std::path::Path;
  50 use std::sync::{Arc, Mutex};
  51 use std::time::{Duration, SystemTime};
  52
  53 pub(crate) enum HTLCStatus {
  54         Pending,
  55         Succeeded,
  56         Failed,
  57 }
  58
  59 pub(crate) struct MillisatAmount(Option<u64>);
  60
  61 impl fmt::Display for MillisatAmount {
  62         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  63                 match self.0 {
  64                         Some(amt) => write!(f, "{}", amt),
  65                         None => write!(f, "unknown"),
  66                 }
  67         }
  68 }
  69
  70 pub(crate) struct PaymentInfo {
  71         preimage: Option<PaymentPreimage>,
  72         secret: Option<PaymentSecret>,
  73         status: HTLCStatus,
  74         amt_msat: MillisatAmount,
  75 }
  76
  77 pub(crate) type PaymentInfoStorage = Arc<Mutex<HashMap<PaymentHash, PaymentInfo>>>;
  78
  79 type ChainMonitor = chainmonitor::ChainMonitor<
  80         InMemorySigner,
  81         Arc<dyn Filter + Send + Sync>,
  82         Arc<BitcoindClient>,
  83         Arc<BitcoindClient>,
  84         Arc<FilesystemLogger>,
  85         Arc<FilesystemPersister>,
  86 >;
  87
  88 pub(crate) type PeerManager = SimpleArcPeerManager<
  89         SocketDescriptor,
  90         ChainMonitor,
  91         BitcoindClient,
  92         BitcoindClient,
  93         dyn chain::Access + Send + Sync,
  94         FilesystemLogger,
  95 >;
  96
  97 pub(crate) type ChannelManager =
  98         SimpleArcChannelManager<ChainMonitor, BitcoindClient, BitcoindClient, FilesystemLogger>;
  99
 100 async fn handle_ldk_events(
 101         channel_manager: Arc<ChannelManager>, bitcoind_client: Arc<BitcoindClient>,
 102         keys_manager: Arc<KeysManager>, inbound_payments: PaymentInfoStorage,
 103         outbound_payments: PaymentInfoStorage, network: Network, event: &Event,
 104 ) {
 105         match event {
 106                 Event::FundingGenerationReady {
 107                         temporary_channel_id,
 108                         channel_value_satoshis,
 109                         output_script,
 110                         ..
 111                 } => {
 112                         // Construct the raw transaction with one output, that is paid the amount of the
 113                         // channel.
 114                         let addr = WitnessProgram::from_scriptpubkey(
 115                                 &output_script[..],
 116                                 match network {
 117                                         Network::Bitcoin => bitcoin_bech32::constants::Network::Bitcoin,
 118                                         Network::Testnet => bitcoin_bech32::constants::Network::Testnet,
 119                                         Network::Regtest => bitcoin_bech32::constants::Network::Regtest,
 120                                         Network::Signet => panic!("Signet unsupported"),
 121                                 },
 122                         )
 123                         .expect("Lightning funding tx should always be to a SegWit output")
 124                         .to_address();
 125                         let mut outputs = vec![HashMap::with_capacity(1)];
 126                         outputs[0].insert(addr, *channel_value_satoshis as f64 / 100_000_000.0);
 127                         let raw_tx = bitcoind_client.create_raw_transaction(outputs).await;
 128
 129                         // Have your wallet put the inputs into the transaction such that the output is
 130                         // satisfied.
 131                         let funded_tx = bitcoind_client.fund_raw_transaction(raw_tx).await;
 132
 133                         // Sign the final funding transaction and broadcast it.
 134                         let signed_tx = bitcoind_client.sign_raw_transaction_with_wallet(funded_tx.hex).await;
 135                         assert_eq!(signed_tx.complete, true);
 136                         let final_tx: Transaction =
 137                                 encode::deserialize(&hex_utils::to_vec(&signed_tx.hex).unwrap()).unwrap();
 138                         // Give the funding transaction back to LDK for opening the channel.
 139                         if channel_manager
 140                                 .funding_transaction_generated(&temporary_channel_id, final_tx)
 141                                 .is_err()
 142                         {
 143                                 println!(
 144                                         "\nERROR: Channel went away before we could fund it. The peer disconnected or refused the channel.");
 145                                 print!("> ");
 146                                 io::stdout().flush().unwrap();
 147                         }
 148                 }
 149                 Event::PaymentReceived { payment_hash, purpose, amt, .. } => {
 150                         let mut payments = inbound_payments.lock().unwrap();
 151                         let (payment_preimage, payment_secret) = match purpose {
 152                                 PaymentPurpose::InvoicePayment { payment_preimage, payment_secret, .. } => {
 153                                         (*payment_preimage, Some(*payment_secret))
 154                                 }
 155                                 PaymentPurpose::SpontaneousPayment(preimage) => (Some(*preimage), None),
 156                         };
 157                         let status = match channel_manager.claim_funds(payment_preimage.unwrap()) {
 158                                 true => {
 159                                         println!(
 160                                                 "\nEVENT: received payment from payment hash {} of {} millisatoshis",
 161                                                 hex_utils::hex_str(&payment_hash.0),
 162                                                 amt
 163                                         );
 164                                         print!("> ");
 165                                         io::stdout().flush().unwrap();
 166                                         HTLCStatus::Succeeded
 167                                 }
 168                                 _ => HTLCStatus::Failed,
 169                         };
 170                         match payments.entry(*payment_hash) {
 171                                 Entry::Occupied(mut e) => {
 172                                         let payment = e.get_mut();
 173                                         payment.status = status;
 174                                         payment.preimage = payment_preimage;
 175                                         payment.secret = payment_secret;
 176                                 }
 177                                 Entry::Vacant(e) => {
 178                                         e.insert(PaymentInfo {
 179                                                 preimage: payment_preimage,
 180                                                 secret: payment_secret,
 181                                                 status,
 182                                                 amt_msat: MillisatAmount(Some(*amt)),
 183                                         });
 184                                 }
 185                         }
 186                 }
 187                 Event::PaymentSent { payment_preimage } => {
 188                         let hashed = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 189                         let mut payments = outbound_payments.lock().unwrap();
 190                         for (payment_hash, payment) in payments.iter_mut() {
 191                                 if *payment_hash == hashed {
 192                                         payment.preimage = Some(*payment_preimage);
 193                                         payment.status = HTLCStatus::Succeeded;
 194                                         println!(
 195                                                 "\nEVENT: successfully sent payment of {} millisatoshis from \
 196                                                                  payment hash {:?} with preimage {:?}",
 197                                                 payment.amt_msat,
 198                                                 hex_utils::hex_str(&payment_hash.0),
 199                                                 hex_utils::hex_str(&payment_preimage.0)
 200                                         );
 201                                         print!("> ");
 202                                         io::stdout().flush().unwrap();
 203                                 }
 204                         }
 205                 }
 206                 Event::PaymentPathFailed {
 207                         payment_hash,
 208                         rejected_by_dest,
 209                         network_update: _,
 210                         all_paths_failed,
 211                         path: _,
 212                 } => {
 213                         print!(
 214                                 "\nEVENT: Failed to send payment{} to payment hash {:?}: ",
 215                                 if *all_paths_failed { "" } else { " along MPP path" },
 216                                 hex_utils::hex_str(&payment_hash.0)
 217                         );
 218                         if *rejected_by_dest {
 219                                 println!("re-attempting the payment will not succeed");
 220                         } else {
 221                                 println!("payment may be retried");
 222                         }
 223                         print!("> ");
 224                         io::stdout().flush().unwrap();
 225
 226                         let mut payments = outbound_payments.lock().unwrap();
 227                         if payments.contains_key(&payment_hash) {
 228                                 let payment = payments.get_mut(&payment_hash).unwrap();
 229                                 payment.status = HTLCStatus::Failed;
 230                         }
 231                 }
 232                 Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
 233                         let from_onchain_str = if *claim_from_onchain_tx {
 234                                 "from onchain downstream claim"
 235                         } else {
 236                                 "from HTLC fulfill message"
 237                         };
 238                         if let Some(fee_earned) = fee_earned_msat {
 239                                 println!(
 240                                         "\nEVENT: Forwarded payment, earning {} msat {}",
 241                                         fee_earned, from_onchain_str
 242                                 );
 243                         } else {
 244                                 println!("\nEVENT: Forwarded payment, claiming onchain {}", from_onchain_str);
 245                         }
 246                         print!("> ");
 247                         io::stdout().flush().unwrap();
 248                 }
 249                 Event::PendingHTLCsForwardable { time_forwardable } => {
 250                         let forwarding_channel_manager = channel_manager.clone();
 251                         let min = time_forwardable.as_millis() as u64;
 252                         tokio::spawn(async move {
 253                                 let millis_to_sleep = thread_rng().gen_range(min, min * 5) as u64;
 254                                 tokio::time::sleep(Duration::from_millis(millis_to_sleep)).await;
 255                                 forwarding_channel_manager.process_pending_htlc_forwards();
 256                         });
 257                 }
 258                 Event::SpendableOutputs { outputs } => {
 259                         let destination_address = bitcoind_client.get_new_address().await;
 260                         let output_descriptors = &outputs.iter().map(|a| a).collect::<Vec<_>>();
 261                         let tx_feerate =
 262                                 bitcoind_client.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 263                         let spending_tx = keys_manager
 264                                 .spend_spendable_outputs(
 265                                         output_descriptors,
 266                                         Vec::new(),
 267                                         destination_address.script_pubkey(),
 268                                         tx_feerate,
 269                                         &Secp256k1::new(),
 270                                 )
 271                                 .unwrap();
 272                         bitcoind_client.broadcast_transaction(&spending_tx);
 273                 }
 274                 Event::ChannelClosed { channel_id, reason } => {
 275                         println!(
 276                                 "\nEVENT: Channel {} closed due to: {:?}",
 277                                 hex_utils::hex_str(channel_id),
 278                                 reason
 279                         );
 280                         print!("> ");
 281                         io::stdout().flush().unwrap();
 282                 }
 283         }
 284 }
 285
 286 async fn start_ldk() {
 287         let args = match cli::parse_startup_args() {
 288                 Ok(user_args) => user_args,
 289                 Err(()) => return,
 290         };
 291
 292         // Initialize the LDK data directory if necessary.
 293         let ldk_data_dir = format!("{}/.ldk", args.ldk_storage_dir_path);
 294         fs::create_dir_all(ldk_data_dir.clone()).unwrap();
 295
 296         // Initialize our bitcoind client.
 297         let bitcoind_client = match BitcoindClient::new(
 298                 args.bitcoind_rpc_host.clone(),
 299                 args.bitcoind_rpc_port,
 300                 args.bitcoind_rpc_username.clone(),
 301                 args.bitcoind_rpc_password.clone(),
 302         )
 303         .await
 304         {
 305                 Ok(client) => Arc::new(client),
 306                 Err(e) => {
 307                         println!("Failed to connect to bitcoind client: {}", e);
 308                         return;
 309                 }
 310         };
 311
 312         // Check that the bitcoind we've connected to is running the network we expect
 313         let bitcoind_chain = bitcoind_client.get_blockchain_info().await.chain;
 314         if bitcoind_chain
 315                 != match args.network {
 316                         bitcoin::Network::Bitcoin => "main",
 317                         bitcoin::Network::Testnet => "test",
 318                         bitcoin::Network::Regtest => "regtest",
 319                         bitcoin::Network::Signet => "signet",
 320                 } {
 321                 println!(
 322                         "Chain argument ({}) didn't match bitcoind chain ({})",
 323                         args.network, bitcoind_chain
 324                 );
 325                 return;
 326         }
 327
 328         // ## Setup
 329         // Step 1: Initialize the FeeEstimator
 330
 331         // BitcoindClient implements the FeeEstimator trait, so it'll act as our fee estimator.
 332         let fee_estimator = bitcoind_client.clone();
 333
 334         // Step 2: Initialize the Logger
 335         let logger = Arc::new(FilesystemLogger::new(ldk_data_dir.clone()));
 336
 337         // Step 3: Initialize the BroadcasterInterface
 338
 339         // BitcoindClient implements the BroadcasterInterface trait, so it'll act as our transaction
 340         // broadcaster.
 341         let broadcaster = bitcoind_client.clone();
 342
 343         // Step 4: Initialize Persist
 344         let persister = Arc::new(FilesystemPersister::new(ldk_data_dir.clone()));
 345
 346         // Step 5: Initialize the ChainMonitor
 347         let chain_monitor: Arc<ChainMonitor> = Arc::new(chainmonitor::ChainMonitor::new(
 348                 None,
 349                 broadcaster.clone(),
 350                 logger.clone(),
 351                 fee_estimator.clone(),
 352                 persister.clone(),
 353         ));
 354
 355         // Step 6: Initialize the KeysManager
 356
 357         // The key seed that we use to derive the node privkey (that corresponds to the node pubkey) and
 358         // other secret key material.
 359         let keys_seed_path = format!("{}/keys_seed", ldk_data_dir.clone());
 360         let keys_seed = if let Ok(seed) = fs::read(keys_seed_path.clone()) {
 361                 assert_eq!(seed.len(), 32);
 362                 let mut key = [0; 32];
 363                 key.copy_from_slice(&seed);
 364                 key
 365         } else {
 366                 let mut key = [0; 32];
 367                 thread_rng().fill_bytes(&mut key);
 368                 match File::create(keys_seed_path.clone()) {
 369                         Ok(mut f) => {
 370                                 f.write_all(&key).expect("Failed to write node keys seed to disk");
 371                                 f.sync_all().expect("Failed to sync node keys seed to disk");
 372                         }
 373                         Err(e) => {
 374                                 println!("ERROR: Unable to create keys seed file {}: {}", keys_seed_path, e);
 375                                 return;
 376                         }
 377                 }
 378                 key
 379         };
 380         let cur = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 381         let keys_manager = Arc::new(KeysManager::new(&keys_seed, cur.as_secs(), cur.subsec_nanos()));
 382
 383         // Step 7: Read ChannelMonitor state from disk
 384         let mut channelmonitors = persister.read_channelmonitors(keys_manager.clone()).unwrap();
 385
 386         // Step 8: Initialize the ChannelManager
 387         let mut user_config = UserConfig::default();
 388         user_config.peer_channel_config_limits.force_announced_channel_preference = false;
 389         let mut restarting_node = true;
 390         let (channel_manager_blockhash, mut channel_manager) = {
 391                 if let Ok(mut f) = fs::File::open(format!("{}/manager", ldk_data_dir.clone())) {
 392                         let mut channel_monitor_mut_references = Vec::new();
 393                         for (_, channel_monitor) in channelmonitors.iter_mut() {
 394                                 channel_monitor_mut_references.push(channel_monitor);
 395                         }
 396                         let read_args = ChannelManagerReadArgs::new(
 397                                 keys_manager.clone(),
 398                                 fee_estimator.clone(),
 399                                 chain_monitor.clone(),
 400                                 broadcaster.clone(),
 401                                 logger.clone(),
 402                                 user_config,
 403                                 channel_monitor_mut_references,
 404                         );
 405                         <(BlockHash, ChannelManager)>::read(&mut f, read_args).unwrap()
 406                 } else {
 407                         // We're starting a fresh node.
 408                         restarting_node = false;
 409                         let getinfo_resp = bitcoind_client.get_blockchain_info().await;
 410
 411                         let chain_params = ChainParameters {
 412                                 network: args.network,
 413                                 best_block: BestBlock::new(
 414                                         getinfo_resp.latest_blockhash,
 415                                         getinfo_resp.latest_height as u32,
 416                                 ),
 417                         };
 418                         let fresh_channel_manager = channelmanager::ChannelManager::new(
 419                                 fee_estimator.clone(),
 420                                 chain_monitor.clone(),
 421                                 broadcaster.clone(),
 422                                 logger.clone(),
 423                                 keys_manager.clone(),
 424                                 user_config,
 425                                 chain_params,
 426                         );
 427                         (getinfo_resp.latest_blockhash, fresh_channel_manager)
 428                 }
 429         };
 430
 431         // Step 9: Sync ChannelMonitors and ChannelManager to chain tip
 432         let mut chain_listener_channel_monitors = Vec::new();
 433         let mut cache = UnboundedCache::new();
 434         let mut chain_tip: Option<poll::ValidatedBlockHeader> = None;
 435         if restarting_node {
 436                 let mut chain_listeners =
 437                         vec![(channel_manager_blockhash, &mut channel_manager as &mut dyn chain::Listen)];
 438
 439                 for (blockhash, channel_monitor) in channelmonitors.drain(..) {
 440                         let outpoint = channel_monitor.get_funding_txo().0;
 441                         chain_listener_channel_monitors.push((
 442                                 blockhash,
 443                                 (channel_monitor, broadcaster.clone(), fee_estimator.clone(), logger.clone()),
 444                                 outpoint,
 445                         ));
 446                 }
 447
 448                 for monitor_listener_info in chain_listener_channel_monitors.iter_mut() {
 449                         chain_listeners.push((
 450                                 monitor_listener_info.0,
 451                                 &mut monitor_listener_info.1 as &mut dyn chain::Listen,
 452                         ));
 453                 }
 454                 chain_tip = Some(
 455                         init::synchronize_listeners(
 456                                 &mut bitcoind_client.deref(),
 457                                 args.network,
 458                                 &mut cache,
 459                                 chain_listeners,
 460                         )
 461                         .await
 462                         .unwrap(),
 463                 );
 464         }
 465
 466         // Step 10: Give ChannelMonitors to ChainMonitor
 467         for item in chain_listener_channel_monitors.drain(..) {
 468                 let channel_monitor = item.1 .0;
 469                 let funding_outpoint = item.2;
 470                 chain_monitor.watch_channel(funding_outpoint, channel_monitor).unwrap();
 471         }
 472
 473         // Step 11: Optional: Initialize the NetGraphMsgHandler
 474         let genesis = genesis_block(args.network).header.block_hash();
 475         let network_graph_path = format!("{}/network_graph", ldk_data_dir.clone());
 476         let network_graph = disk::read_network(Path::new(&network_graph_path), genesis);
 477         let router = Arc::new(NetGraphMsgHandler::new(
 478                 network_graph,
 479                 None::<Arc<dyn chain::Access + Send + Sync>>,
 480                 logger.clone(),
 481         ));
 482         let router_persist = Arc::clone(&router);
 483         tokio::spawn(async move {
 484                 let mut interval = tokio::time::interval(Duration::from_secs(600));
 485                 loop {
 486                         interval.tick().await;
 487                         if disk::persist_network(Path::new(&network_graph_path), &router_persist.network_graph)
 488                                 .is_err()
 489                         {
 490                                 // Persistence errors here are non-fatal as we can just fetch the routing graph
 491                                 // again later, but they may indicate a disk error which could be fatal elsewhere.
 492                                 eprintln!(
 493                                         "Warning: Failed to persist network graph, check your disk and permissions"
 494                                 );
 495                         }
 496                 }
 497         });
 498
 499         // Step 12: Initialize the PeerManager
 500         let channel_manager: Arc<ChannelManager> = Arc::new(channel_manager);
 501         let mut ephemeral_bytes = [0; 32];
 502         rand::thread_rng().fill_bytes(&mut ephemeral_bytes);
 503         let lightning_msg_handler =
 504                 MessageHandler { chan_handler: channel_manager.clone(), route_handler: router.clone() };
 505         let peer_manager: Arc<PeerManager> = Arc::new(PeerManager::new(
 506                 lightning_msg_handler,
 507                 keys_manager.get_node_secret(),
 508                 &ephemeral_bytes,
 509                 logger.clone(),
 510                 Arc::new(IgnoringMessageHandler {}),
 511         ));
 512
 513         // ## Running LDK
 514         // Step 13: Initialize networking
 515
 516         let peer_manager_connection_handler = peer_manager.clone();
 517         let listening_port = args.ldk_peer_listening_port;
 518         tokio::spawn(async move {
 519                 let listener = tokio::net::TcpListener::bind(format!("0.0.0.0:{}", listening_port))
 520                         .await
 521                         .expect("Failed to bind to listen port - is something else already listening on it?");
 522                 loop {
 523                         let peer_mgr = peer_manager_connection_handler.clone();
 524                         let tcp_stream = listener.accept().await.unwrap().0;
 525                         tokio::spawn(async move {
 526                                 lightning_net_tokio::setup_inbound(
 527                                         peer_mgr.clone(),
 528                                         tcp_stream.into_std().unwrap(),
 529                                 )
 530                                 .await;
 531                         });
 532                 }
 533         });
 534
 535         // Step 14: Connect and Disconnect Blocks
 536         if chain_tip.is_none() {
 537                 chain_tip =
 538                         Some(init::validate_best_block_header(&mut bitcoind_client.deref()).await.unwrap());
 539         }
 540         let channel_manager_listener = channel_manager.clone();
 541         let chain_monitor_listener = chain_monitor.clone();
 542         let bitcoind_block_source = bitcoind_client.clone();
 543         let network = args.network;
 544         tokio::spawn(async move {
 545                 let mut derefed = bitcoind_block_source.deref();
 546                 let chain_poller = poll::ChainPoller::new(&mut derefed, network);
 547                 let chain_listener = (chain_monitor_listener, channel_manager_listener);
 548                 let mut spv_client =
 549                         SpvClient::new(chain_tip.unwrap(), chain_poller, &mut cache, &chain_listener);
 550                 loop {
 551                         spv_client.poll_best_tip().await.unwrap();
 552                         tokio::time::sleep(Duration::from_secs(1)).await;
 553                 }
 554         });
 555
 556         // Step 15: Handle LDK Events
 557         let channel_manager_event_listener = channel_manager.clone();
 558         let keys_manager_listener = keys_manager.clone();
 559         // TODO: persist payment info to disk
 560         let inbound_payments: PaymentInfoStorage = Arc::new(Mutex::new(HashMap::new()));
 561         let outbound_payments: PaymentInfoStorage = Arc::new(Mutex::new(HashMap::new()));
 562         let inbound_pmts_for_events = inbound_payments.clone();
 563         let outbound_pmts_for_events = outbound_payments.clone();
 564         let network = args.network;
 565         let bitcoind_rpc = bitcoind_client.clone();
 566         let handle = tokio::runtime::Handle::current();
 567         let event_handler = move |event: &Event| {
 568                 handle.block_on(handle_ldk_events(
 569                         channel_manager_event_listener.clone(),
 570                         bitcoind_rpc.clone(),
 571                         keys_manager_listener.clone(),
 572                         inbound_pmts_for_events.clone(),
 573                         outbound_pmts_for_events.clone(),
 574                         network,
 575                         event,
 576                 ));
 577         };
 578         // Step 16: Persist ChannelManager
 579         let data_dir = ldk_data_dir.clone();
 580         let persist_channel_manager_callback =
 581                 move |node: &ChannelManager| FilesystemPersister::persist_manager(data_dir.clone(), &*node);
 582         // Step 17: Background Processing
 583         let background_processor = BackgroundProcessor::start(
 584                 persist_channel_manager_callback,
 585                 event_handler,
 586                 chain_monitor.clone(),
 587                 channel_manager.clone(),
 588                 Some(router.clone()),
 589                 peer_manager.clone(),
 590                 logger.clone(),
 591         );
 592
 593         // Reconnect to channel peers if possible.
 594         let peer_data_path = format!("{}/channel_peer_data", ldk_data_dir.clone());
 595         match disk::read_channel_peer_data(Path::new(&peer_data_path)) {
 596                 Ok(mut info) => {
 597                         for (pubkey, peer_addr) in info.drain() {
 598                                 for chan_info in channel_manager.list_channels() {
 599                                         if pubkey == chan_info.counterparty.node_id {
 600                                                 let _ =
 601                                                         cli::connect_peer_if_necessary(pubkey, peer_addr, peer_manager.clone())
 602                                                                 .await;
 603                                         }
 604                                 }
 605                         }
 606                 }
 607                 Err(e) => println!("ERROR: errored reading channel peer info from disk: {:?}", e),
 608         }
 609
 610         // Regularly broadcast our node_announcement. This is only required (or possible) if we have
 611         // some public channels, and is only useful if we have public listen address(es) to announce.
 612         // In a production environment, this should occur only after the announcement of new channels
 613         // to avoid churn in the global network graph.
 614         let chan_manager = Arc::clone(&channel_manager);
 615         let network = args.network;
 616         if !args.ldk_announced_listen_addr.is_empty() {
 617                 tokio::spawn(async move {
 618                         let mut interval = tokio::time::interval(Duration::from_secs(60));
 619                         loop {
 620                                 interval.tick().await;
 621                                 chan_manager.broadcast_node_announcement(
 622                                         [0; 3],
 623                                         args.ldk_announced_node_name,
 624                                         args.ldk_announced_listen_addr.clone(),
 625                                 );
 626                         }
 627                 });
 628         }
 629
 630         // Start the CLI.
 631         cli::poll_for_user_input(
 632                 peer_manager.clone(),
 633                 channel_manager.clone(),
 634                 keys_manager.clone(),
 635                 router.clone(),
 636                 inbound_payments,
 637                 outbound_payments,
 638                 ldk_data_dir.clone(),
 639                 logger.clone(),
 640                 network,
 641         )
 642         .await;
 643
 644         // Stop the background processor.
 645         background_processor.stop().unwrap();
 646 }
 647
 648 #[tokio::main]
 649 pub async fn main() {
 650         start_ldk().await;
 651 }