Add APIError::IncompatibleShutdownScript

Author: jkczyz

fuzz/src/chanmon_consistency.rs

@@ -253,6 +253,7 @@ fn check_api_err(api_err: APIError) {
 		APIError::MonitorUpdateFailed => {
 			// We can (obviously) temp-fail a monitor update
 		},
+		APIError::IncompatibleShutdownScript { .. } => panic!("Cannot send an incompatible shutdown script"),
 	}
 }
 #[inline]

lightning/src/ln/channel.rs

@@ -601,8 +601,8 @@ impl<Signer: Sign> Channel<Signer> {
 		} else { None };
 
 		if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey {
-			if !shutdown_scriptpubkey.is_compatible(their_features) {
-				return Err(APIError::APIMisuseError { err: format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey) });
+			if !shutdown_scriptpubkey.is_compatible(&their_features) {
+				return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
 			}
 		}
 
@@ -4474,7 +4474,7 @@ impl<Signer: Sign> Channel<Signer> {
 			None => {
 				let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
 				if !shutdown_scriptpubkey.is_compatible(their_features) {
-					return Err(APIError::APIMisuseError { err: format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey) });
+					return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
 				}
 				self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
 				true

lightning/src/util/errors.rs

@@ -9,6 +9,8 @@
 
 //! Error types live here.
 
+use ln::script::ShutdownScript;
+
 use alloc::string::String;
 use core::fmt;
 
@@ -47,6 +49,15 @@ pub enum APIError {
 	/// An attempt to call watch/update_channel returned an Err (ie you did this!), causing the
 	/// attempted action to fail.
 	MonitorUpdateFailed,
+	/// [`KeysInterface::get_shutdown_scriptpubkey`] returned a shutdown scriptpubkey incompatible
+	/// with the channel counterparty as negotiated in [`InitFeatures`].
+	///
+	/// [`KeysInterface::get_shutdown_scriptpubkey`]: crate::chain::keysinterface::KeysInterface::get_shutdown_scriptpubkey
+	/// [`InitFeatures`]: crate::ln::features::InitFeatures
+	IncompatibleShutdownScript {
+		/// The incompatible shutdown script.
+		script: ShutdownScript,
+	},
 }
 
 impl fmt::Debug for APIError {
@@ -57,6 +68,9 @@ impl fmt::Debug for APIError {
 			APIError::RouteError {ref err} => f.write_str(err),
 			APIError::ChannelUnavailable {ref err} => f.write_str(err),
 			APIError::MonitorUpdateFailed => f.write_str("Client indicated a channel monitor update failed"),
+			APIError::IncompatibleShutdownScript { ref script } => {
+				write!(f, "Provided a scriptpubkey format not accepted by peer: {}", script)
+			},
 		}
 	}
 }