Merge pull request #116 from wpaulino/anchors

Add support for opening anchor outputs channels

Author: TheBlueMatt

src/bitcoind_client.rs

@@ -1,13 +1,19 @@
 use crate::convert::{
-	BlockchainInfo, FeeResponse, FundedTx, MempoolMinFeeResponse, NewAddress, RawTx, SignedTx,
+	BlockchainInfo, FeeResponse, FundedTx, ListUnspentResponse, MempoolMinFeeResponse, NewAddress,
+	RawTx, SignedTx,
 };
 use crate::disk::FilesystemLogger;
+use crate::hex_utils;
 use base64;
+use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
 use bitcoin::blockdata::transaction::Transaction;
-use bitcoin::consensus::encode;
+use bitcoin::consensus::{encode, Decodable, Encodable};
 use bitcoin::hash_types::{BlockHash, Txid};
-use bitcoin::util::address::Address;
+use bitcoin::hashes::Hash;
+use bitcoin::util::address::{Address, Payload, WitnessVersion};
+use bitcoin::{OutPoint, Script, TxOut, WPubkeyHash, XOnlyPublicKey};
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
+use lightning::events::bump_transaction::{Utxo, WalletSource};
 use lightning::log_error;
 use lightning::routing::utxo::{UtxoLookup, UtxoResult};
 use lightning::util::logger::Logger;
@@ -250,6 +256,13 @@ impl BitcoindClient {
 			.await
 			.unwrap()
 	}
+
+	pub async fn list_unspent(&self) -> ListUnspentResponse {
+		self.bitcoind_rpc_client
+			.call_method::<ListUnspentResponse>("listunspent", &vec![])
+			.await
+			.unwrap()
+	}
 }
 
 impl FeeEstimator for BitcoindClient {
@@ -308,3 +321,55 @@ impl UtxoLookup for BitcoindClient {
 		todo!();
 	}
 }
+
+impl WalletSource for BitcoindClient {
+	fn list_confirmed_utxos(&self) -> Result<Vec<Utxo>, ()> {
+		let utxos = tokio::task::block_in_place(move || {
+			self.handle.block_on(async move { self.list_unspent().await }).0
+		});
+		Ok(utxos
+			.into_iter()
+			.filter_map(|utxo| {
+				let outpoint = OutPoint { txid: utxo.txid, vout: utxo.vout };
+				match utxo.address.payload {
+					Payload::WitnessProgram { version, ref program } => match version {
+						WitnessVersion::V0 => WPubkeyHash::from_slice(program)
+							.map(|wpkh| Utxo::new_v0_p2wpkh(outpoint, utxo.amount, &wpkh))
+							.ok(),
+						// TODO: Add `Utxo::new_v1_p2tr` upstream.
+						WitnessVersion::V1 => XOnlyPublicKey::from_slice(program)
+							.map(|_| Utxo {
+								outpoint,
+								output: TxOut {
+									value: utxo.amount,
+									script_pubkey: Script::new_witness_program(version, program),
+								},
+								satisfaction_weight: 1 /* empty script_sig */ * WITNESS_SCALE_FACTOR as u64 +
+									1 /* witness items */ + 1 /* schnorr sig len */ + 64, /* schnorr sig */
+							})
+							.ok(),
+						_ => None,
+					},
+					_ => None,
+				}
+			})
+			.collect())
+	}
+
+	fn get_change_script(&self) -> Result<Script, ()> {
+		tokio::task::block_in_place(move || {
+			Ok(self.handle.block_on(async move { self.get_new_address().await.script_pubkey() }))
+		})
+	}
+
+	fn sign_tx(&self, tx: Transaction) -> Result<Transaction, ()> {
+		let mut tx_bytes = Vec::new();
+		let _ = tx.consensus_encode(&mut tx_bytes).map_err(|_| ());
+		let tx_hex = hex_utils::hex_str(&tx_bytes);
+		let signed_tx = tokio::task::block_in_place(move || {
+			self.handle.block_on(async move { self.sign_raw_transaction_with_wallet(tx_hex).await })
+		});
+		let signed_tx_bytes = hex_utils::to_vec(&signed_tx.hex).ok_or(())?;
+		Transaction::consensus_decode(&mut signed_tx_bytes.as_slice()).map_err(|_| ())
+	}
+}

src/cli.rs

@@ -93,7 +93,7 @@ pub(crate) async fn poll_for_user_input(
 					let peer_pubkey_and_ip_addr = words.next();
 					let channel_value_sat = words.next();
 					if peer_pubkey_and_ip_addr.is_none() || channel_value_sat.is_none() {
-						println!("ERROR: openchannel has 2 required arguments: `openchannel pubkey@host:port channel_amt_satoshis` [--public]");
+						println!("ERROR: openchannel has 2 required arguments: `openchannel pubkey@host:port channel_amt_satoshis` [--public] [--with-anchors]");
 						continue;
 					}
 					let peer_pubkey_and_ip_addr = peer_pubkey_and_ip_addr.unwrap();
@@ -119,20 +119,25 @@ pub(crate) async fn poll_for_user_input(
 						continue;
 					};
 
-					let announce_channel = match words.next() {
-						Some("--public") | Some("--public=true") => true,
-						Some("--public=false") => false,
-						Some(_) => {
-							println!("ERROR: invalid `--public` command format. Valid formats: `--public`, `--public=true` `--public=false`");
-							continue;
+					let (mut announce_channel, mut with_anchors) = (false, false);
+					while let Some(word) = words.next() {
+						match word {
+							"--public" | "--public=true" => announce_channel = true,
+							"--public=false" => announce_channel = false,
+							"--with-anchors" | "--with-anchors=true" => with_anchors = true,
+							"--with-anchors=false" => with_anchors = false,
+							_ => {
+								println!("ERROR: invalid boolean flag format. Valid formats: `--option`, `--option=true` `--option=false`");
+								continue;
+							}
 						}
-						None => false,
-					};
+					}
 
 					if open_channel(
 						pubkey,
 						chan_amt_sat.unwrap(),
 						announce_channel,
+						with_anchors,
 						channel_manager.clone(),
 					)
 					.is_ok()
@@ -455,7 +460,7 @@ fn help() {
 	println!("  help\tShows a list of commands.");
 	println!("  quit\tClose the application.");
 	println!("\n  Channels:");
-	println!("      openchannel pubkey@host:port <amt_satoshis> [--public]");
+	println!("      openchannel pubkey@host:port <amt_satoshis> [--public] [--with-anchors]");
 	println!("      closechannel <channel_id> <peer_pubkey>");
 	println!("      forceclosechannel <channel_id> <peer_pubkey>");
 	println!("      listchannels");
@@ -638,7 +643,7 @@ fn do_disconnect_peer(
 }
 
 fn open_channel(
-	peer_pubkey: PublicKey, channel_amt_sat: u64, announced_channel: bool,
+	peer_pubkey: PublicKey, channel_amt_sat: u64, announced_channel: bool, with_anchors: bool,
 	channel_manager: Arc<ChannelManager>,
 ) -> Result<(), ()> {
 	let config = UserConfig {
@@ -649,6 +654,7 @@ fn open_channel(
 		},
 		channel_handshake_config: ChannelHandshakeConfig {
 			announced_channel,
+			negotiate_anchors_zero_fee_htlc_tx: with_anchors,
 			..Default::default()
 		},
 		..Default::default()

src/convert.rs

@@ -1,7 +1,8 @@
 use bitcoin::hashes::hex::FromHex;
-use bitcoin::BlockHash;
+use bitcoin::{Address, BlockHash, Txid};
 use lightning_block_sync::http::JsonResponse;
 use std::convert::TryInto;
+use std::str::FromStr;
 
 pub struct FundedTx {
 	pub changepos: i64,
@@ -116,3 +117,33 @@ impl TryInto<BlockchainInfo> for JsonResponse {
 		})
 	}
 }
+
+pub struct ListUnspentUtxo {
+	pub txid: Txid,
+	pub vout: u32,
+	pub amount: u64,
+	pub address: Address,
+}
+
+pub struct ListUnspentResponse(pub Vec<ListUnspentUtxo>);
+
+impl TryInto<ListUnspentResponse> for JsonResponse {
+	type Error = std::io::Error;
+	fn try_into(self) -> Result<ListUnspentResponse, Self::Error> {
+		let utxos = self
+			.0
+			.as_array()
+			.unwrap()
+			.iter()
+			.map(|utxo| ListUnspentUtxo {
+				txid: Txid::from_str(&utxo["txid"].as_str().unwrap().to_string()).unwrap(),
+				vout: utxo["vout"].as_u64().unwrap() as u32,
+				amount: bitcoin::Amount::from_btc(utxo["amount"].as_f64().unwrap())
+					.unwrap()
+					.to_sat(),
+				address: Address::from_str(&utxo["address"].as_str().unwrap().to_string()).unwrap(),
+			})
+			.collect();
+		Ok(ListUnspentResponse(utxos))
+	}
+}

src/main.rs

@@ -16,6 +16,7 @@ use bitcoin_bech32::WitnessProgram;
 use disk::{INBOUND_PAYMENTS_FNAME, OUTBOUND_PAYMENTS_FNAME};
 use lightning::chain::{chainmonitor, ChannelMonitorUpdateStatus};
 use lightning::chain::{Filter, Watch};
+use lightning::events::bump_transaction::{BumpTransactionEventHandler, Wallet};
 use lightning::events::{Event, PaymentFailureReason, PaymentPurpose};
 use lightning::ln::channelmanager::{self, RecentPaymentDetails};
 use lightning::ln::channelmanager::{
@@ -141,10 +142,17 @@ pub(crate) type NetworkGraph = gossip::NetworkGraph<Arc<FilesystemLogger>>;
 
 type OnionMessenger = SimpleArcOnionMessenger<FilesystemLogger>;
 
+pub(crate) type BumpTxEventHandler = BumpTransactionEventHandler<
+	Arc<BitcoindClient>,
+	Arc<Wallet<Arc<BitcoindClient>, Arc<FilesystemLogger>>>,
+	Arc<KeysManager>,
+	Arc<FilesystemLogger>,
+>;
+
 async fn handle_ldk_events(
 	channel_manager: &Arc<ChannelManager>, bitcoind_client: &BitcoindClient,
 	network_graph: &NetworkGraph, keys_manager: &KeysManager,
-	inbound_payments: Arc<Mutex<PaymentInfoStorage>>,
+	bump_tx_event_handler: &BumpTxEventHandler, inbound_payments: Arc<Mutex<PaymentInfoStorage>>,
 	outbound_payments: Arc<Mutex<PaymentInfoStorage>>, persister: &Arc<FilesystemPersister>,
 	network: Network, event: Event,
 ) {
@@ -278,8 +286,34 @@ async fn handle_ldk_events(
 			}
 			persister.persist(OUTBOUND_PAYMENTS_FNAME, &*outbound).unwrap();
 		}
-		Event::OpenChannelRequest { .. } => {
-			// Unreachable, we don't set manually_accept_inbound_channels
+		Event::OpenChannelRequest {
+			ref temporary_channel_id, ref counterparty_node_id, ..
+		} => {
+			let mut random_bytes = [0u8; 16];
+			random_bytes.copy_from_slice(&keys_manager.get_secure_random_bytes()[..16]);
+			let user_channel_id = u128::from_be_bytes(random_bytes);
+			let res = channel_manager.accept_inbound_channel(
+				temporary_channel_id,
+				counterparty_node_id,
+				user_channel_id,
+			);
+
+			if let Err(e) = res {
+				print!(
+					"\nEVENT: Failed to accept inbound channel ({}) from {}: {:?}",
+					hex_utils::hex_str(&temporary_channel_id[..]),
+					hex_utils::hex_str(&counterparty_node_id.serialize()),
+					e,
+				);
+			} else {
+				print!(
+					"\nEVENT: Accepted inbound channel ({}) from {}",
+					hex_utils::hex_str(&temporary_channel_id[..]),
+					hex_utils::hex_str(&counterparty_node_id.serialize()),
+				);
+			}
+			print!("> ");
+			io::stdout().flush().unwrap();
 		}
 		Event::PaymentPathSuccessful { .. } => {}
 		Event::PaymentPathFailed { .. } => {}
@@ -429,7 +463,7 @@ async fn handle_ldk_events(
 			// the funding transaction either confirms, or this event is generated.
 		}
 		Event::HTLCIntercepted { .. } => {}
-		Event::BumpTransaction(_) => {}
+		Event::BumpTransaction(event) => bump_tx_event_handler.handle_event(&event),
 	}
 }
 
@@ -532,6 +566,13 @@ async fn start_ldk() {
 	let cur = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
 	let keys_manager = Arc::new(KeysManager::new(&keys_seed, cur.as_secs(), cur.subsec_nanos()));
 
+	let bump_tx_event_handler = Arc::new(BumpTransactionEventHandler::new(
+		Arc::clone(&broadcaster),
+		Arc::new(Wallet::new(Arc::clone(&bitcoind_client), Arc::clone(&logger))),
+		Arc::clone(&keys_manager),
+		Arc::clone(&logger),
+	));
+
 	// Step 7: Read ChannelMonitor state from disk
 	let mut channelmonitors =
 		persister.read_channelmonitors(keys_manager.clone(), keys_manager.clone()).unwrap();
@@ -566,6 +607,8 @@ async fn start_ldk() {
 	// Step 11: Initialize the ChannelManager
 	let mut user_config = UserConfig::default();
 	user_config.channel_handshake_limits.force_announced_channel_preference = false;
+	user_config.channel_handshake_config.negotiate_anchors_zero_fee_htlc_tx = true;
+	user_config.manually_accept_inbound_channels = true;
 	let mut restarting_node = true;
 	let (channel_manager_blockhash, channel_manager) = {
 		if let Ok(mut f) = fs::File::open(format!("{}/manager", ldk_data_dir.clone())) {
@@ -778,6 +821,7 @@ async fn start_ldk() {
 		let bitcoind_client_event_listener = Arc::clone(&bitcoind_client_event_listener);
 		let network_graph_event_listener = Arc::clone(&network_graph_event_listener);
 		let keys_manager_event_listener = Arc::clone(&keys_manager_event_listener);
+		let bump_tx_event_handler = Arc::clone(&bump_tx_event_handler);
 		let inbound_payments_event_listener = Arc::clone(&inbound_payments_event_listener);
 		let outbound_payments_event_listener = Arc::clone(&outbound_payments_event_listener);
 		let persister_event_listener = Arc::clone(&persister_event_listener);
@@ -787,6 +831,7 @@ async fn start_ldk() {
 				&bitcoind_client_event_listener,
 				&network_graph_event_listener,
 				&keys_manager_event_listener,
+				&bump_tx_event_handler,
 				inbound_payments_event_listener,
 				outbound_payments_event_listener,
 				&persister_event_listener,