Add Payjoin Receiver Support

Cargo.toml

@@ -80,6 +80,8 @@ prost = { version = "0.11.6", default-features = false}
 #bitcoin-payment-instructions = { version = "0.6" }
 bitcoin-payment-instructions = { git = "https://github.com/tnull/bitcoin-payment-instructions", rev = "ea50a9d2a8da524b69a2af43233706666cf2ffa5" }
 
+payjoin = { git = "https://github.com/payjoin/rust-payjoin.git", package = "payjoin", default-features = false, features = ["v2", "io"] }
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["winbase"] }
 

src/builder.rs

@@ -45,7 +45,7 @@ use vss_client::headers::VssHeaderProvider;
 use crate::chain::ChainSource;
 use crate::config::{
 	default_user_config, may_announce_channel, AnnounceError, AsyncPaymentsRole,
-	BitcoindRestClientConfig, Config, ElectrumSyncConfig, EsploraSyncConfig,
+	BitcoindRestClientConfig, Config, ElectrumSyncConfig, EsploraSyncConfig, PayjoinConfig,
 	DEFAULT_ESPLORA_SERVER_URL, DEFAULT_LOG_FILENAME, DEFAULT_LOG_LEVEL,
 };
 use crate::connection::ConnectionManager;
@@ -56,12 +56,13 @@ use crate::gossip::GossipSource;
 use crate::io::sqlite_store::SqliteStore;
 use crate::io::utils::{
 	read_event_queue, read_external_pathfinding_scores_from_cache, read_network_graph,
-	read_node_metrics, read_output_sweeper, read_payments, read_peer_info, read_pending_payments,
-	read_scorer, write_node_metrics,
+	read_node_metrics, read_output_sweeper, read_payjoin_sessions, read_payments, read_peer_info,
+	read_pending_payments, read_scorer, write_node_metrics,
 };
 use crate::io::vss_store::VssStoreBuilder;
 use crate::io::{
-	self, PAYMENT_INFO_PERSISTENCE_PRIMARY_NAMESPACE, PAYMENT_INFO_PERSISTENCE_SECONDARY_NAMESPACE,
+	self, PAYJOIN_SESSION_STORE_PRIMARY_NAMESPACE, PAYJOIN_SESSION_STORE_SECONDARY_NAMESPACE,
+	PAYMENT_INFO_PERSISTENCE_PRIMARY_NAMESPACE, PAYMENT_INFO_PERSISTENCE_SECONDARY_NAMESPACE,
 	PENDING_PAYMENT_INFO_PERSISTENCE_PRIMARY_NAMESPACE,
 	PENDING_PAYMENT_INFO_PERSISTENCE_SECONDARY_NAMESPACE,
 };
@@ -71,13 +72,14 @@ use crate::liquidity::{
 use crate::logger::{log_error, LdkLogger, LogLevel, LogWriter, Logger};
 use crate::message_handler::NodeCustomMessageHandler;
 use crate::payment::asynchronous::om_mailbox::OnionMessageMailbox;
+use crate::payment::payjoin::manager::PayjoinManager;
 use crate::peer_store::PeerStore;
 use crate::runtime::{Runtime, RuntimeSpawner};
 use crate::tx_broadcaster::TransactionBroadcaster;
 use crate::types::{
 	AsyncPersister, ChainMonitor, ChannelManager, DynStore, DynStoreWrapper, GossipSync, Graph,
-	KeysManager, MessageRouter, OnionMessenger, PaymentStore, PeerManager, PendingPaymentStore,
-	Persister, SyncAndAsyncKVStore,
+	KeysManager, MessageRouter, OnionMessenger, PayjoinSessionStore, PaymentStore, PeerManager,
+	PendingPaymentStore, Persister, SyncAndAsyncKVStore,
 };
 use crate::wallet::persist::KVStoreWalletPersister;
 use crate::wallet::Wallet;
@@ -547,6 +549,15 @@ impl NodeBuilder {
 		Ok(self)
 	}
 
+	/// Configures the [`Node`] instance to enable payjoin payments.
+	///
+	/// The `payjoin_config` specifies the PayJoin directory and OHTTP relay URLs required
+	/// for payjoin V2 protocol.
+	pub fn set_payjoin_config(&mut self, payjoin_config: PayjoinConfig) -> &mut Self {
+		self.config.payjoin_config = Some(payjoin_config);
+		self
+	}
+
 	/// Configures the [`Node`] to resync chain data from genesis on first startup, recovering any
 	/// historical wallet funds.
 	///
@@ -933,6 +944,14 @@ impl ArcedNodeBuilder {
 		self.inner.write().unwrap().set_async_payments_role(role).map(|_| ())
 	}
 
+	/// Configures the [`Node`] instance to enable payjoin payments.
+	///
+	/// The `payjoin_config` specifies the PayJoin directory and OHTTP relay URLs required
+	/// for payjoin V2 protocol.
+	pub fn set_payjoin_config(&self, payjoin_config: PayjoinConfig) {
+		self.inner.write().unwrap().set_payjoin_config(payjoin_config);
+	}
+
 	/// Configures the [`Node`] to resync chain data from genesis on first startup, recovering any
 	/// historical wallet funds.
 	///
@@ -1083,12 +1102,13 @@ fn build_with_store_internal(
 
 	let kv_store_ref = Arc::clone(&kv_store);
 	let logger_ref = Arc::clone(&logger);
-	let (payment_store_res, node_metris_res, pending_payment_store_res) =
+	let (payment_store_res, node_metris_res, pending_payment_store_res, payjoin_session_store_res) =
 		runtime.block_on(async move {
 			tokio::join!(
 				read_payments(&*kv_store_ref, Arc::clone(&logger_ref)),
 				read_node_metrics(&*kv_store_ref, Arc::clone(&logger_ref)),
-				read_pending_payments(&*kv_store_ref, Arc::clone(&logger_ref))
+				read_pending_payments(&*kv_store_ref, Arc::clone(&logger_ref)),
+				read_payjoin_sessions(&*kv_store_ref, Arc::clone(&logger_ref))
 			)
 		});
 
@@ -1771,6 +1791,34 @@ fn build_with_store_internal(
 
 	let pathfinding_scores_sync_url = pathfinding_scores_sync_config.map(|c| c.url.clone());
 
+	let payjoin_session_store = match payjoin_session_store_res {
+		Ok(payjoin_sessions) => Arc::new(PayjoinSessionStore::new(
+			payjoin_sessions,
+			PAYJOIN_SESSION_STORE_PRIMARY_NAMESPACE.to_string(),
+			PAYJOIN_SESSION_STORE_SECONDARY_NAMESPACE.to_string(),
+			Arc::clone(&kv_store),
+			Arc::clone(&logger),
+		)),
+		Err(e) => {
+			log_error!(logger, "Failed to read payjoin session data from store: {}", e);
+			return Err(BuildError::ReadFailed);
+		},
+	};
+
+	let payjoin_manager = Arc::new(PayjoinManager::new(
+		Arc::clone(&payjoin_session_store),
+		Arc::clone(&logger),
+		Arc::clone(&config),
+		Arc::clone(&wallet),
+		Arc::clone(&fee_estimator),
+		Arc::clone(&chain_source),
+		Arc::clone(&channel_manager),
+		stop_sender.subscribe(),
+		Arc::clone(&payment_store),
+		Arc::clone(&pending_payment_store),
+		Arc::clone(&tx_broadcaster),
+	));
+
 	#[cfg(cycle_tests)]
 	let mut _leak_checker = crate::LeakChecker(Vec::new());
 	#[cfg(cycle_tests)]
@@ -1817,6 +1865,7 @@ fn build_with_store_internal(
 		hrn_resolver,
 		#[cfg(cycle_tests)]
 		_leak_checker,
+		payjoin_manager,
 	})
 }
 

src/chain/bitcoind.rs

@@ -619,6 +619,57 @@ impl BitcoindChainSource {
 			}
 		}
 	}
+
+	pub(crate) async fn can_broadcast_transaction(&self, tx: &Transaction) -> Result<bool, Error> {
+		let timeout_fut = tokio::time::timeout(
+			Duration::from_secs(DEFAULT_TX_BROADCAST_TIMEOUT_SECS),
+			self.api_client.test_mempool_accept(tx),
+		);
+
+		match timeout_fut.await {
+			Ok(res) => res.map_err(|e| {
+				log_error!(
+					self.logger,
+					"Failed to test mempool accept for transaction {}: {}",
+					tx.compute_txid(),
+					e
+				);
+				Error::TxBroadcastFailed
+			}),
+			Err(e) => {
+				log_error!(
+					self.logger,
+					"Failed to test mempool accept for transaction {} due to timeout: {}",
+					tx.compute_txid(),
+					e
+				);
+				log_trace!(
+					self.logger,
+					"Failed test mempool accept transaction bytes: {}",
+					log_bytes!(tx.encode())
+				);
+				Err(Error::TxBroadcastFailed)
+			},
+		}
+	}
+
+	pub(crate) async fn get_transaction(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+		let timeout_fut = tokio::time::timeout(
+			Duration::from_secs(DEFAULT_TX_BROADCAST_TIMEOUT_SECS),
+			self.api_client.get_raw_transaction(txid),
+		);
+
+		match timeout_fut.await {
+			Ok(res) => res.map_err(|e| {
+				log_error!(self.logger, "Failed to get transaction {}: {}", txid, e);
+				Error::TxSyncFailed
+			}),
+			Err(e) => {
+				log_error!(self.logger, "Failed to get transaction {} due to timeout: {}", txid, e);
+				Err(Error::TxSyncTimeout)
+			},
+		}
+	}
 }
 
 #[derive(Clone)]
@@ -1229,6 +1280,46 @@ impl BitcoindClient {
 			.collect();
 		Ok(evicted_txids)
 	}
+
+	/// Tests whether the provided transaction would be accepted by the mempool.
+	pub(crate) async fn test_mempool_accept(&self, tx: &Transaction) -> std::io::Result<bool> {
+		match self {
+			BitcoindClient::Rpc { rpc_client, .. } => {
+				Self::test_mempool_accept_inner(Arc::clone(rpc_client), tx).await
+			},
+			BitcoindClient::Rest { rpc_client, .. } => {
+				// We rely on the internal RPC client to make this call, as this
+				// operation is not supported by Bitcoin Core's REST interface.
+				Self::test_mempool_accept_inner(Arc::clone(rpc_client), tx).await
+			},
+		}
+	}
+
+	async fn test_mempool_accept_inner(
+		rpc_client: Arc<RpcClient>, tx: &Transaction,
+	) -> std::io::Result<bool> {
+		let tx_serialized = bitcoin::consensus::encode::serialize_hex(tx);
+		let tx_array = serde_json::json!([tx_serialized]);
+
+		let resp =
+			rpc_client.call_method::<serde_json::Value>("testmempoolaccept", &[tx_array]).await?;
+
+		if let Some(array) = resp.as_array() {
+			if let Some(first_result) = array.first() {
+				Ok(first_result.get("allowed").and_then(|v| v.as_bool()).unwrap_or(false))
+			} else {
+				Err(std::io::Error::new(
+					std::io::ErrorKind::Other,
+					"Empty array response from testmempoolaccept",
+				))
+			}
+		} else {
+			Err(std::io::Error::new(
+				std::io::ErrorKind::InvalidData,
+				"testmempoolaccept did not return an array",
+			))
+		}
+	}
 }
 
 impl BlockSource for BitcoindClient {

src/chain/electrum.rs

@@ -288,6 +288,21 @@ impl ElectrumChainSource {
 			electrum_client.broadcast(tx).await;
 		}
 	}
+
+	pub(crate) async fn get_transaction(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+		let electrum_client: Arc<ElectrumRuntimeClient> =
+			if let Some(client) = self.electrum_runtime_status.read().unwrap().client().as_ref() {
+				Arc::clone(client)
+			} else {
+				debug_assert!(
+					false,
+					"We should have started the chain source before getting transactions"
+				);
+				return Err(Error::TxSyncFailed);
+			};
+
+		electrum_client.get_transaction(txid).await
+	}
 }
 
 impl Filter for ElectrumChainSource {
@@ -652,6 +667,48 @@ impl ElectrumRuntimeClient {
 
 		Ok(new_fee_rate_cache)
 	}
+
+	async fn get_transaction(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+		let electrum_client = Arc::clone(&self.electrum_client);
+		let txid_copy = *txid;
+
+		let spawn_fut =
+			self.runtime.spawn_blocking(move || electrum_client.transaction_get(&txid_copy));
+		let timeout_fut = tokio::time::timeout(
+			Duration::from_secs(
+				self.sync_config.timeouts_config.lightning_wallet_sync_timeout_secs,
+			),
+			spawn_fut,
+		);
+
+		match timeout_fut.await {
+			Ok(res) => match res {
+				Ok(inner_res) => match inner_res {
+					Ok(tx) => Ok(Some(tx)),
+					Err(e) => {
+						// Check if it's a "not found" error
+						let error_str = e.to_string();
+						if error_str.contains("No such mempool or blockchain transaction")
+							|| error_str.contains("not found")
+						{
+							Ok(None)
+						} else {
+							log_error!(self.logger, "Failed to get transaction {}: {}", txid, e);
+							Err(Error::TxSyncFailed)
+						}
+					},
+				},
+				Err(e) => {
+					log_error!(self.logger, "Failed to get transaction {}: {}", txid, e);
+					Err(Error::TxSyncFailed)
+				},
+			},
+			Err(e) => {
+				log_error!(self.logger, "Failed to get transaction {} due to timeout: {}", txid, e);
+				Err(Error::TxSyncTimeout)
+			},
+		}
+	}
 }
 
 impl Filter for ElectrumRuntimeClient {

src/chain/esplora.rs

@@ -422,6 +422,13 @@ impl EsploraChainSource {
 			}
 		}
 	}
+
+	pub(crate) async fn get_transaction(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+		self.esplora_client.get_tx(txid).await.map_err(|e| {
+			log_error!(self.logger, "Failed to get transaction {}: {}", txid, e);
+			Error::TxSyncFailed
+		})
+	}
 }
 
 impl Filter for EsploraChainSource {

src/chain/mod.rs

@@ -13,7 +13,7 @@ use std::collections::HashMap;
 use std::sync::{Arc, Mutex, RwLock};
 use std::time::Duration;
 
-use bitcoin::{Script, Txid};
+use bitcoin::{Script, Transaction, Txid};
 use lightning::chain::{BestBlock, Filter};
 
 use crate::chain::bitcoind::{BitcoindChainSource, UtxoSourceClient};
@@ -468,6 +468,38 @@ impl ChainSource {
 			}
 		}
 	}
+
+	pub(crate) fn can_broadcast_transaction(&self, tx: &Transaction) -> Result<bool, Error> {
+		tokio::task::block_in_place(|| {
+			tokio::runtime::Handle::current().block_on(async {
+				match &self.kind {
+					ChainSourceKind::Bitcoind(bitcoind_chain_source) => {
+						bitcoind_chain_source.can_broadcast_transaction(tx).await
+					},
+					ChainSourceKind::Esplora{..} => {
+						// Esplora doesn't support testmempoolaccept equivalent.
+						unreachable!("Mempool accept testing is not supported with Esplora backend. Use BitcoindRpc for this functionality.")
+					},
+					ChainSourceKind::Electrum{..} => {
+						// Electrum doesn't support testmempoolaccept equivalent.
+						unreachable!("Mempool accept testing is not supported with Electrum backend. Use BitcoindRpc for this functionality.")
+					},
+				}
+			})
+		})
+	}
+
+	pub(crate) fn get_transaction(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+		tokio::task::block_in_place(|| {
+			tokio::runtime::Handle::current().block_on(async {
+				match &self.kind {
+					ChainSourceKind::Bitcoind(bitcoind) => bitcoind.get_transaction(txid).await,
+					ChainSourceKind::Esplora(esplora) => esplora.get_transaction(txid).await,
+					ChainSourceKind::Electrum(electrum) => electrum.get_transaction(txid).await,
+				}
+			})
+		})
+	}
 }
 
 impl Filter for ChainSource {