Get dispatch weight from the target chain (when DispatchFeePayment::AtTargetChain is used)

bin/millau/runtime/src/lib.rs

@@ -833,16 +833,26 @@ impl_runtime_apis! {
 			lane: bp_messages::LaneId,
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
-		) -> Vec<bp_messages::MessageDetails<Balance>> {
+		) -> Vec<bp_messages::OutboundMessageDetails<Balance>> {
 			bridge_runtime_common::messages_api::outbound_message_details::<
 				Runtime,
 				WithRialtoMessagesInstance,
-				WithRialtoMessageBridge,
-				xcm_config::OutboundXcmWeigher,
 			>(lane, begin, end)
 		}
 	}
 
+	impl bp_rialto::FromRialtoInboundLaneApi<Block, bp_rialto::Balance> for Runtime {
+		fn message_details(
+			lane: bp_messages::LaneId,
+			messages: Vec<(bp_messages::MessagePayload, bp_messages::OutboundMessageDetails<bp_rialto::Balance>)>,
+		) -> Vec<bp_messages::InboundMessageDetails> {
+			bridge_runtime_common::messages_api::inbound_message_details::<
+				Runtime,
+				WithRialtoMessagesInstance,
+			>(lane, messages)
+		}
+	}
+
 	impl bp_rialto_parachain::ToRialtoParachainOutboundLaneApi<Block, Balance, ToRialtoParachainMessagePayload> for Runtime {
 		fn estimate_message_delivery_and_dispatch_fee(
 			_lane_id: bp_messages::LaneId,
@@ -860,16 +870,26 @@ impl_runtime_apis! {
 			lane: bp_messages::LaneId,
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
-		) -> Vec<bp_messages::MessageDetails<Balance>> {
+		) -> Vec<bp_messages::OutboundMessageDetails<Balance>> {
 			bridge_runtime_common::messages_api::outbound_message_details::<
 				Runtime,
 				WithRialtoParachainMessagesInstance,
-				WithRialtoParachainMessageBridge,
-				xcm_config::OutboundXcmWeigher,
 			>(lane, begin, end)
 		}
 	}
 
+	impl bp_rialto_parachain::FromRialtoParachainInboundLaneApi<Block, bp_rialto_parachain::Balance> for Runtime {
+		fn message_details(
+			lane: bp_messages::LaneId,
+			messages: Vec<(bp_messages::MessagePayload, bp_messages::OutboundMessageDetails<bp_rialto_parachain::Balance>)>,
+		) -> Vec<bp_messages::InboundMessageDetails> {
+			bridge_runtime_common::messages_api::inbound_message_details::<
+				Runtime,
+				WithRialtoParachainMessagesInstance,
+			>(lane, messages)
+		}
+	}
+
 	#[cfg(feature = "runtime-benchmarks")]
 	impl frame_benchmarking::Benchmark<Block> for Runtime {
 		fn benchmark_metadata(extra: bool) -> (

bin/millau/runtime/src/xcm_config.rs

@@ -122,8 +122,6 @@ pub type Barrier = (
 	AllowKnownQueryResponses<XcmPallet>,
 );
 
-/// Outbound XCM weigher type.
-pub type OutboundXcmWeigher = xcm_builder::FixedWeightBounds<BaseXcmWeight, (), MaxInstructions>;
 /// XCM weigher type.
 pub type XcmWeigher = xcm_builder::FixedWeightBounds<BaseXcmWeight, Call, MaxInstructions>;
 

bin/rialto-parachain/runtime/src/lib.rs

@@ -383,8 +383,6 @@ pub type Barrier = (
 	// ^^^ Parent & its unit plurality gets free execution
 );
 
-/// Outbound XCM weigher type.
-pub type OutboundXcmWeigher = FixedWeightBounds<UnitWeightCost, (), MaxInstructions>;
 /// XCM weigher type.
 pub type XcmWeigher = FixedWeightBounds<UnitWeightCost, Call, MaxInstructions>;
 
@@ -708,16 +706,26 @@ impl_runtime_apis! {
 			lane: bp_messages::LaneId,
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
-		) -> Vec<bp_messages::MessageDetails<Balance>> {
+		) -> Vec<bp_messages::OutboundMessageDetails<Balance>> {
 			bridge_runtime_common::messages_api::outbound_message_details::<
 				Runtime,
 				WithMillauMessagesInstance,
-				WithMillauMessageBridge,
-				OutboundXcmWeigher,
 			>(lane, begin, end)
 		}
 	}
 
+	impl bp_millau::FromMillauInboundLaneApi<Block, bp_millau::Balance> for Runtime {
+		fn message_details(
+			lane: bp_messages::LaneId,
+			messages: Vec<(bp_messages::MessagePayload, bp_messages::OutboundMessageDetails<bp_millau::Balance>)>,
+		) -> Vec<bp_messages::InboundMessageDetails> {
+			bridge_runtime_common::messages_api::inbound_message_details::<
+				Runtime,
+				WithMillauMessagesInstance,
+			>(lane, messages)
+		}
+	}
+
 	#[cfg(feature = "runtime-benchmarks")]
 	impl frame_benchmarking::Benchmark<Block> for Runtime {
 		fn dispatch_benchmark(

bin/rialto/runtime/src/lib.rs

@@ -893,15 +893,25 @@ impl_runtime_apis! {
 			lane: bp_messages::LaneId,
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
-		) -> Vec<bp_messages::MessageDetails<Balance>> {
+		) -> Vec<bp_messages::OutboundMessageDetails<Balance>> {
 			bridge_runtime_common::messages_api::outbound_message_details::<
 				Runtime,
 				WithMillauMessagesInstance,
-				WithMillauMessageBridge,
-				xcm_config::OutboundXcmWeigher,
 			>(lane, begin, end)
 		}
 	}
+
+	impl bp_millau::FromMillauInboundLaneApi<Block, bp_millau::Balance> for Runtime {
+		fn message_details(
+			lane: bp_messages::LaneId,
+			messages: Vec<(bp_messages::MessagePayload, bp_messages::OutboundMessageDetails<bp_millau::Balance>)>,
+		) -> Vec<bp_messages::InboundMessageDetails> {
+			bridge_runtime_common::messages_api::inbound_message_details::<
+				Runtime,
+				WithMillauMessagesInstance,
+			>(lane, messages)
+		}
+	}
 }
 
 #[cfg(test)]

bin/rialto/runtime/src/xcm_config.rs

@@ -122,8 +122,6 @@ pub type Barrier = (
 	AllowKnownQueryResponses<XcmPallet>,
 );
 
-/// Outbound XCM weigher type.
-pub type OutboundXcmWeigher = xcm_builder::FixedWeightBounds<BaseXcmWeight, (), MaxInstructions>;
 /// Incoming XCM weigher type.
 pub type XcmWeigher = xcm_builder::FixedWeightBounds<BaseXcmWeight, Call, MaxInstructions>;
 

bin/runtime-common/src/messages_api.rs

@@ -16,68 +16,54 @@
 
 //! Helpers for implementing various message-related runtime API mthods.
 
-use crate::messages::{target::FromBridgedChainMessagePayload, MessageBridge};
-
-use bp_messages::{LaneId, MessageDetails, MessageKey, MessageNonce};
-use codec::Decode;
-use frame_support::weights::Weight;
+use bp_messages::{
+	InboundMessageDetails, LaneId, MessageNonce, MessagePayload, OutboundMessageDetails,
+};
 use sp_std::vec::Vec;
 
 /// Implementation of the `To*OutboundLaneApi::message_details`.
-pub fn outbound_message_details<Runtime, MessagesPalletInstance, BridgeConfig, XcmWeigher>(
+pub fn outbound_message_details<Runtime, MessagesPalletInstance>(
 	lane: LaneId,
 	begin: MessageNonce,
 	end: MessageNonce,
-) -> Vec<MessageDetails<Runtime::OutboundMessageFee>>
+) -> Vec<OutboundMessageDetails<Runtime::OutboundMessageFee>>
 where
 	Runtime: pallet_bridge_messages::Config<MessagesPalletInstance>,
 	MessagesPalletInstance: 'static,
-	BridgeConfig: MessageBridge,
-	XcmWeigher: xcm_executor::traits::WeightBounds<()>,
 {
 	(begin..=end)
 		.filter_map(|nonce| {
 			let message_data =
 				pallet_bridge_messages::Pallet::<Runtime, MessagesPalletInstance>::outbound_message_data(lane, nonce)?;
-			Some(MessageDetails {
+			Some(OutboundMessageDetails {
 				nonce,
-				// this shall match the similar code in the `FromBridgedChainMessageDispatch` - if we have failed
-				// to decode or estimate dispatch weight, we'll just return 0 to disable actual execution
-				dispatch_weight: compute_message_weight::<XcmWeigher>(
-					MessageKey { lane_id: lane, nonce },
-					&message_data.payload,
-				).unwrap_or(0),
+				// dispatch message weight is always zero at the source chain, since we're paying for
+				// dispatch at the target chain
+				dispatch_weight: 0,
 				size: message_data.payload.len() as _,
 				delivery_and_dispatch_fee: message_data.fee,
+				// we're delivering XCM messages here, so fee is always paid at the target chain
 				dispatch_fee_payment: bp_runtime::messages::DispatchFeePayment::AtTargetChain,
 			})
 		})
 		.collect()
 }
 
-// at the source chain we don't know the type of target chain `Call` => `()` is used (it is
-// similarly currently used in Polkadot codebase)
-fn compute_message_weight<XcmWeigher: xcm_executor::traits::WeightBounds<()>>(
-	message_key: MessageKey,
-	encoded_payload: &[u8],
-) -> Result<Weight, ()> {
-	let mut payload = FromBridgedChainMessagePayload::<()>::decode(&mut &encoded_payload[..])
-		.map_err(|e| {
-			log::debug!(
-				target: "runtime::bridge-dispatch",
-				"Failed to decode outbound XCM message {:?}: {:?}",
-				message_key,
-				e,
-			);
-		})?;
-	let weight = XcmWeigher::weight(&mut payload.xcm.1);
-	let weight = weight.map_err(|e| {
-		log::debug!(
-			target: "runtime::bridge-dispatch",
-			"Failed to compute dispatch weight of outbound XCM message {:?}: {:?}",
-			message_key,
-			e,
-		);
-	})?;
-	Ok(weight)
+/// Implementation of the `To*InboundLaneApi::message_details`.
+pub fn inbound_message_details<Runtime, MessagesPalletInstance>(
+	lane: LaneId,
+	messages: Vec<(MessagePayload, OutboundMessageDetails<Runtime::InboundMessageFee>)>,
+) -> Vec<InboundMessageDetails>
+where
+	Runtime: pallet_bridge_messages::Config<MessagesPalletInstance>,
+	MessagesPalletInstance: 'static,
+{
+	messages
+		.into_iter()
+		.map(|(payload, details)| {
+			pallet_bridge_messages::Pallet::<Runtime, MessagesPalletInstance>::inbound_message_data(
+				lane, payload, details,
+			)
+		})
+		.collect()
 }

modules/messages/src/lib.rs

@@ -56,9 +56,10 @@ use bp_messages::{
 	target_chain::{
 		DispatchMessage, MessageDispatch, ProvedLaneMessages, ProvedMessages, SourceHeaderChain,
 	},
-	total_unrewarded_messages, DeliveredMessages, InboundLaneData, LaneId, MessageData, MessageKey,
-	MessageNonce, OperatingMode, OutboundLaneData, Parameter as MessagesParameter,
-	UnrewardedRelayer, UnrewardedRelayersState,
+	total_unrewarded_messages, DeliveredMessages, InboundLaneData, InboundMessageDetails, LaneId,
+	MessageData, MessageKey, MessageNonce, MessagePayload, OperatingMode, OutboundLaneData,
+	OutboundMessageDetails, Parameter as MessagesParameter, UnrewardedRelayer,
+	UnrewardedRelayersState,
 };
 use bp_runtime::{ChainId, Size};
 use codec::{Decode, Encode};
@@ -156,7 +157,7 @@ pub mod pallet {
 		/// Payload type of inbound messages. This payload is dispatched on this chain.
 		type InboundPayload: Decode;
 		/// Message fee type of inbound messages. This fee is paid on the bridged chain.
-		type InboundMessageFee: Decode;
+		type InboundMessageFee: Decode + Zero;
 		/// Identifier of relayer that deliver messages to this chain. Relayer reward is paid on the
 		/// bridged chain.
 		type InboundRelayer: Parameter;
@@ -762,6 +763,22 @@ pub mod pallet {
 		) -> Option<MessageData<T::OutboundMessageFee>> {
 			OutboundMessages::<T, I>::get(MessageKey { lane_id: lane, nonce })
 		}
+
+		/// Prepare data, related to given inbound message.
+		pub fn inbound_message_data(
+			lane: LaneId,
+			payload: MessagePayload,
+			outbound_details: OutboundMessageDetails<T::InboundMessageFee>,
+		) -> InboundMessageDetails {
+			let mut dispatch_message = DispatchMessage {
+				key: MessageKey { lane_id: lane, nonce: outbound_details.nonce },
+				data: MessageData { payload, fee: outbound_details.delivery_and_dispatch_fee }
+					.into(),
+			};
+			InboundMessageDetails {
+				dispatch_weight: T::MessageDispatch::dispatch_weight(&mut dispatch_message),
+			}
+		}
 	}
 }
 
@@ -2332,4 +2349,25 @@ mod tests {
 			bp_messages::storage_keys::inbound_lane_data_key("Messages", &TEST_LANE_ID).0,
 		);
 	}
+
+	#[test]
+	fn inbound_message_details_works() {
+		run_test(|| {
+			assert_eq!(
+				Pallet::<TestRuntime>::inbound_message_data(
+					TEST_LANE_ID,
+					REGULAR_PAYLOAD.encode(),
+					OutboundMessageDetails {
+						nonce: 0,
+						dispatch_weight: 0,
+						size: 0,
+						delivery_and_dispatch_fee: 0,
+						dispatch_fee_payment:
+							bp_runtime::messages::DispatchFeePayment::AtTargetChain,
+					},
+				),
+				InboundMessageDetails { dispatch_weight: REGULAR_PAYLOAD.declared_weight },
+			);
+		});
+	}
 }

primitives/chain-kusama/src/lib.rs

@@ -18,7 +18,9 @@
 // RuntimeApi generated functions
 #![allow(clippy::too_many_arguments)]
 
-use bp_messages::{LaneId, MessageDetails, MessageNonce};
+use bp_messages::{
+	InboundMessageDetails, LaneId, MessageNonce, MessagePayload, OutboundMessageDetails,
+};
 use frame_support::weights::{
 	WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial,
 };
@@ -105,6 +107,9 @@ pub const TO_KUSAMA_ESTIMATE_MESSAGE_FEE_METHOD: &str =
 /// Name of the `ToKusamaOutboundLaneApi::message_details` runtime method.
 pub const TO_KUSAMA_MESSAGE_DETAILS_METHOD: &str = "ToKusamaOutboundLaneApi_message_details";
 
+/// Name of the `FromKusamaInboundLaneApi::message_details` runtime method.
+pub const FROM_KUSAMA_MESSAGE_DETAILS_METHOD: &str = "FromKusamaInboundLaneApi_message_details";
+
 sp_api::decl_runtime_apis! {
 	/// API for querying information about the finalized Kusama headers.
 	///
@@ -143,6 +148,21 @@ sp_api::decl_runtime_apis! {
 			lane: LaneId,
 			begin: MessageNonce,
 			end: MessageNonce,
-		) -> Vec<MessageDetails<OutboundMessageFee>>;
+		) -> Vec<OutboundMessageDetails<OutboundMessageFee>>;
+	}
+
+	/// Inbound message lane API for messages sent by Kusama chain.
+	///
+	/// This API is implemented by runtimes that are receiving messages from Kusama chain, not the
+	/// Kusama runtime itself.
+	///
+	/// Entries of the resulting vector are matching entries of the `messages` vector. Entries of the
+	/// `messages` vector may (and need to) be read using `To<ThisChain>OutboundLaneApi::message_details`.
+	pub trait FromKusamaInboundLaneApi<InboundMessageFee: Parameter> {
+		/// Return details of given inbound messages.
+		fn message_details(
+			lane: LaneId,
+			messages: Vec<(MessagePayload, OutboundMessageDetails<InboundMessageFee>)>,
+		) -> Vec<InboundMessageDetails>;
 	}
 }