dns bootstrap

Cargo.toml

@@ -28,10 +28,14 @@ chrono = { version = "0.4", default-features = false, features = ["clock"] }
 rand = "0.4"
 serde_json = { version = "1.0" }
 serde = { version = "1.0", features = ["derive"] }
+toml = { version = "0.8" }
 tokio = { version = "1", features = [ "io-util", "macros", "rt", "rt-multi-thread", "sync", "net", "time", "io-std" ] }
 reqwest = { version = "0.11", features = ["tokio-native-tls", "stream"] }
 futures-util = "0.3"
 
+# DNS bootstrap (BOLT-0010)
+hickory-resolver = { version = "0.24", features = ["tokio-runtime"] }
+
 [profile.release]
 panic = "abort"
 

README.md

@@ -12,49 +12,57 @@ cd ldk-sample
 cargo run <ldk_storage_directory_path>
 ```
 The only CLI argument is the storage directory path. All configuration is read from
-`<ldk_storage_directory_path>/.ldk/config.json`.
+`<ldk_storage_directory_path>/.ldk/config.toml`.
 
-Use `config.example.json` in the repo root as a template for your config file.
+Use `config.example.toml` in the repo root as a template for your config file.
 
 ## Configuration
 
-Config is loaded from `<storage_dir>/.ldk/config.json` and strictly validated. Unknown
+Config is loaded from `<storage_dir>/.ldk/config.toml` and strictly validated. Unknown
 fields cause an error (`deny_unknown_fields`).
 
 Required sections: `bitcoind`.
-Optional sections: `ldk`, `rapid_gossip_sync`, and `probing` (probing is disabled if
-missing).
+Optional sections: `ldk`, `rapid_gossip_sync`, `probing` (probing is disabled if
+missing), and `dns_bootstrap` (enabled by default with sensible defaults).
 
 Network options: `mainnet`, `testnet`, `regtest`, `signet` (default is `testnet`).
 
 ### Example config
 
-```json
-{
-  "bitcoind": {
-    "rpc_host": "127.0.0.1",
-    "rpc_port": 8332,
-    "rpc_username": "your_rpc_user",
-    "rpc_password": "your_rpc_password"
-  },
-  "network": "testnet",
-  "ldk": {
-    "peer_listening_port": 9735,
-    "announced_node_name": "MyLDKNode",
-    "announced_listen_addr": []
-  },
-  "rapid_gossip_sync": {
-    "enabled": true,
-    "url": "https://rapidsync.lightningdevkit.org/snapshot/",
-    "interval_hours": 6
-  },
-  "probing": {
-    "interval_sec": 300,
-    "peers": ["02abc123...@1.2.3.4:9735"],
-    "amount_msats": [1000, 10000, 100000, 1000000],
-    "timeout_sec": 60
-  }
-}
+```toml
+network = "testnet"
+
+[bitcoind]
+rpc_host = "127.0.0.1"
+rpc_port = 8332
+rpc_username = "your_rpc_user"
+rpc_password = "your_rpc_password"
+
+# [ldk]
+# peer_listening_port = 9735
+# announced_node_name = "MyLDKNode"
+# announced_listen_addr = []
+
+[rapid_gossip_sync]
+enabled = true
+url = "https://rapidsync.lightningdevkit.org/snapshot/"
+interval_hours = 6
+
+[probing]
+interval_sec = 300
+peers = ["02abc123...@1.2.3.4:9735"]
+amount_msats = [1000, 10000, 100000, 1000000]
+timeout_sec = 60
+
+probe_delay_sec = 1
+peer_delay_sec = 2
+
+[dns_bootstrap]
+enabled = true
+seeds = [ "nodes.lightning.wiki", "lseed.bitcoinstats.com" ]
+timeout_secs = 30
+num_peers = 10
+interval_secs = 300
 ```
 
 ### Key options
@@ -80,6 +88,12 @@ fails, the node falls back to P2P gossip sync. `url` defaults to
 Optional. If omitted, probing is disabled. Configure probe interval, peers, probe
 amounts in millisatoshis, and timeout.
 
+`dns_bootstrap`:
+Optional. Enabled by default. Discovers peers via DNS SRV lookups per BOLT-0010.
+`seeds` defaults to `nodes.lightning.wiki` and `lseed.bitcoinstats.com`.
+`timeout_secs` defaults to 30, `num_peers` defaults to 10, `interval_secs`
+defaults to 300. Set `enabled` to `false` to disable.
+
 ## License
 
 Licensed under either:

config.example.toml

@@ -0,0 +1,27 @@
+[bitcoind]
+rpc_host = "127.0.0.1"
+rpc_port = 8332
+rpc_username = "your_rpc_user"
+rpc_password = "your_rpc_password"
+
+network = "testnet"
+
+[ldk]
+peer_listening_port = 9735
+announced_node_name = "MyLDKNode"
+announced_listen_addr = []
+
+[rapid_gossip_sync]
+enabled = true
+url = "https://rapidsync.lightningdevkit.org/snapshot/"
+interval_hours = 6
+
+[probing]
+interval_sec = 300
+peers = [
+    "02abc123...@1.2.3.4:9735"
+]
+amount_msats = [1000, 10000, 100000, 1000000]
+timeout_sec = 60
+probe_delay_sec = 1
+peer_delay_sec = 2

src/args.rs

@@ -8,7 +8,7 @@ pub(crate) fn parse_startup_args() -> Result<LdkUserInfo, ()> {
 		println!("Usage: {} <ldk_storage_directory_path>", args[0]);
 		println!();
 		println!(
-			"The config.json file should be located at <ldk_storage_directory_path>/.ldk/config.json",
+			"The config.toml file should be located at <ldk_storage_directory_path>/.ldk/config.toml",
 		);
 		crate::config::print_config_help();
 		return Err(());

src/bitcoind_client.rs

@@ -239,10 +239,7 @@ impl BitcoindClient {
 	pub async fn create_raw_transaction(&self, outputs: Vec<HashMap<String, f64>>) -> RawTx {
 		let outputs_json = serde_json::json!(outputs);
 		self.bitcoind_rpc_client
-			.call_method::<RawTx>(
-				"createrawtransaction",
-				&[serde_json::json!([]), outputs_json],
-			)
+			.call_method::<RawTx>("createrawtransaction", &[serde_json::json!([]), outputs_json])
 			.await
 			.unwrap()
 	}
@@ -282,10 +279,7 @@ impl BitcoindClient {
 		let tx_hex_json = serde_json::json!(tx_hex);
 		let rpc_client = self.get_new_rpc_client();
 		async move {
-			rpc_client
-				.call_method("signrawtransactionwithwallet", &[tx_hex_json])
-				.await
-				.unwrap()
+			rpc_client.call_method("signrawtransactionwithwallet", &[tx_hex_json]).await.unwrap()
 		}
 	}
 
@@ -309,9 +303,7 @@ impl BitcoindClient {
 
 	pub fn list_unspent(&self) -> impl Future<Output = ListUnspentResponse> {
 		let rpc_client = self.get_new_rpc_client();
-		async move {
-			rpc_client.call_method::<ListUnspentResponse>("listunspent", &[]).await.unwrap()
-		}
+		async move { rpc_client.call_method::<ListUnspentResponse>("listunspent", &[]).await.unwrap() }
 	}
 }
 
@@ -392,7 +384,7 @@ impl WalletSource for BitcoindClient {
 										value,
 										script_pubkey: utxo.address.script_pubkey(),
 									},
-								satisfaction_weight: WITNESS_SCALE_FACTOR as u64 +
+									satisfaction_weight: WITNESS_SCALE_FACTOR as u64 +
 									1 /* witness items */ + 1 /* schnorr sig len */ + 64, /* schnorr sig */
 								})
 								.ok()

src/cli.rs

@@ -35,7 +35,7 @@ use std::time::Duration;
 
 use tokio::io::{AsyncBufReadExt, BufReader};
 
-/// Probing configuration passed from config.json
+/// Probing configuration passed from config.toml
 #[derive(Clone)]
 pub(crate) struct ProbingConfig {
 	pub(crate) interval_sec: u64,
@@ -60,6 +60,7 @@ pub(crate) struct LdkUserInfo {
 	pub(crate) rapid_gossip_sync_url: Option<String>,
 	pub(crate) rapid_gossip_sync_interval_hours: u64,
 	pub(crate) probing: Option<ProbingConfig>,
+	pub(crate) dns_bootstrap: Option<crate::dns_bootstrap::DnsBootstrapConfig>,
 }
 
 pub(crate) async fn poll_for_user_input(
@@ -322,10 +323,10 @@ pub(crate) async fn poll_for_user_input(
 									&invoice,
 									user_provided_amt,
 									&outbound_payments,
-							&fs_store,
-						)
-						.await
-					},
+									&fs_store,
+								)
+								.await
+							},
 							Err(e) => {
 								println!("ERROR: invalid invoice: {:?}", e);
 							},
@@ -360,15 +361,15 @@ pub(crate) async fn poll_for_user_input(
 							continue;
 						},
 					};
-				keysend(
-					&channel_manager,
-					dest_pubkey,
-					amt_msat,
-					&*keys_manager,
-					&outbound_payments,
-					&fs_store,
-				)
-				.await;
+					keysend(
+						&channel_manager,
+						dest_pubkey,
+						amt_msat,
+						&*keys_manager,
+						&outbound_payments,
+						&fs_store,
+					)
+					.await;
 				},
 				"getoffer" => {
 					let offer_builder = channel_manager.create_offer_builder();
@@ -1025,9 +1026,7 @@ pub(crate) fn parse_peer_info(
 
 	let pubkey = hex_utils::to_compressed_pubkey(pubkey.unwrap());
 	if pubkey.is_none() {
-		return Err(std::io::Error::other(
-			"ERROR: unable to parse given pubkey for node",
-		));
+		return Err(std::io::Error::other("ERROR: unable to parse given pubkey for node"));
 	}
 
 	Ok((pubkey.unwrap(), peer_addr.unwrap().unwrap()))