Forward message id to destination chain (#134)

* forward message id to destination chain

* fix import

Author: alistair-singh

bridges/snowbridge/pallets/inbound-queue/src/lib.rs

@@ -52,8 +52,7 @@ use sp_core::{H160, H256};
 use sp_runtime::traits::Zero;
 use sp_std::{convert::TryFrom, vec};
 use xcm::prelude::{
-	send_xcm, Instruction::SetTopic, Junction::*, Location, SendError as XcmpSendError, SendXcm,
-	Xcm, XcmContext, XcmHash,
+	send_xcm, Junction::*, Location, SendError as XcmpSendError, SendXcm, Xcm, XcmContext, XcmHash,
 };
 use xcm_executor::traits::TransactAsset;
 
@@ -279,7 +278,8 @@ pub mod pallet {
 			// Decode message into XCM
 			let (xcm, fee) =
 				match inbound::VersionedMessage::decode_all(&mut envelope.payload.as_ref()) {
-					Ok(message) => Self::do_convert(envelope.message_id, message)?,
+					Ok(message) => T::MessageConverter::convert(envelope.message_id, message)
+						.map_err(|e| Error::<T>::ConvertMessage(e))?,
 					Err(_) => return Err(Error::<T>::InvalidPayload.into()),
 				};
 
@@ -321,17 +321,6 @@ pub mod pallet {
 	}
 
 	impl<T: Config> Pallet<T> {
-		pub fn do_convert(
-			message_id: H256,
-			message: inbound::VersionedMessage,
-		) -> Result<(Xcm<()>, BalanceOf<T>), Error<T>> {
-			let (mut xcm, fee) =
-				T::MessageConverter::convert(message).map_err(|e| Error::<T>::ConvertMessage(e))?;
-			// Append the message id as an XCM topic
-			xcm.inner_mut().extend(vec![SetTopic(message_id.into())]);
-			Ok((xcm, fee))
-		}
-
 		pub fn send_xcm(xcm: Xcm<()>, dest: ParaId) -> Result<XcmHash, Error<T>> {
 			let dest = Location::new(1, [Parachain(dest.into())]);
 			let (xcm_hash, _) = send_xcm::<T::XcmSender>(dest, xcm).map_err(Error::<T>::from)?;

bridges/snowbridge/primitives/router/src/inbound/mod.rs

@@ -9,7 +9,7 @@ use codec::{Decode, Encode};
 use core::marker::PhantomData;
 use frame_support::{traits::tokens::Balance as BalanceT, weights::Weight, PalletError};
 use scale_info::TypeInfo;
-use sp_core::{Get, RuntimeDebug, H160};
+use sp_core::{Get, RuntimeDebug, H160, H256};
 use sp_io::hashing::blake2_256;
 use sp_runtime::MultiAddress;
 use sp_std::prelude::*;
@@ -115,7 +115,10 @@ pub trait ConvertMessage {
 	type Balance: BalanceT + From<u128>;
 	type AccountId;
 	/// Converts a versioned message into an XCM message and an optional topicID
-	fn convert(message: VersionedMessage) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError>;
+	fn convert(
+		message_id: H256,
+		message: VersionedMessage,
+	) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError>;
 }
 
 pub type CallIndex = [u8; 2];
@@ -138,14 +141,17 @@ impl<CreateAssetCall, CreateAssetDeposit, InboundQueuePalletInstance, AccountId,
 	type Balance = Balance;
 	type AccountId = AccountId;
 
-	fn convert(message: VersionedMessage) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError> {
+	fn convert(
+		message_id: H256,
+		message: VersionedMessage,
+	) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError> {
 		use Command::*;
 		use VersionedMessage::*;
 		match message {
 			V1(MessageV1 { chain_id, command: RegisterToken { token, fee } }) =>
-				Ok(Self::convert_register_token(chain_id, token, fee)),
+				Ok(Self::convert_register_token(message_id, chain_id, token, fee)),
 			V1(MessageV1 { chain_id, command: SendToken { token, destination, amount, fee } }) =>
-				Ok(Self::convert_send_token(chain_id, token, destination, amount, fee)),
+				Ok(Self::convert_send_token(message_id, chain_id, token, destination, amount, fee)),
 		}
 	}
 }
@@ -159,7 +165,12 @@ where
 	Balance: BalanceT + From<u128>,
 	AccountId: Into<[u8; 32]>,
 {
-	fn convert_register_token(chain_id: u64, token: H160, fee: u128) -> (Xcm<()>, Balance) {
+	fn convert_register_token(
+		message_id: H256,
+		chain_id: u64,
+		token: H160,
+		fee: u128,
+	) -> (Xcm<()>, Balance) {
 		let network = Ethereum { chain_id };
 		let xcm_fee: Asset = (Location::parent(), fee).into();
 		let deposit: Asset = (Location::parent(), CreateAssetDeposit::get()).into();
@@ -202,13 +213,16 @@ where
 			// Clear the origin so that remaining assets in holding
 			// are claimable by the physical origin (BridgeHub)
 			ClearOrigin,
+			// Forward message id to Asset Hub
+			SetTopic(message_id.into()),
 		]
 		.into();
 
 		(xcm, total_amount.into())
 	}
 
 	fn convert_send_token(
+		message_id: H256,
 		chain_id: u64,
 		token: H160,
 		destination: Destination,
@@ -266,6 +280,8 @@ where
 							BuyExecution { fees: dest_para_fee_asset, weight_limit: Unlimited },
 							// Deposit asset to beneficiary.
 							DepositAsset { assets: Definite(asset.into()), beneficiary },
+							// Forward message id to destination parachain.
+							SetTopic(message_id.into()),
 						]
 						.into(),
 					},
@@ -279,6 +295,9 @@ where
 			},
 		}
 
+		// Forward message id to Asset Hub.
+		instructions.push(SetTopic(message_id.into()));
+
 		(instructions.into(), total_fees.into())
 	}
 

cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-rococo/src/tests/snowbridge.rs

@@ -27,7 +27,7 @@ use snowbridge_pallet_inbound_queue_fixtures::{
 };
 use snowbridge_pallet_system;
 use snowbridge_router_primitives::inbound::{
-	Command, GlobalConsensusEthereumConvertsFor, MessageV1, VersionedMessage,
+	Command, ConvertMessage, GlobalConsensusEthereumConvertsFor, MessageV1, VersionedMessage,
 };
 use sp_core::H256;
 use sp_runtime::{DispatchError::Token, TokenError::FundsUnavailable};
@@ -527,6 +527,8 @@ fn register_weth_token_in_asset_hub_fail_for_insufficient_fee() {
 		type RuntimeEvent = <BridgeHubRococo as Chain>::RuntimeEvent;
 		type EthereumInboundQueue =
 			<BridgeHubRococo as BridgeHubRococoPallet>::EthereumInboundQueue;
+		type Converter = <bridge_hub_rococo_runtime::Runtime as snowbridge_pallet_inbound_queue::Config>::MessageConverter;
+
 		let message_id: H256 = [0; 32].into();
 		let message = VersionedMessage::V1(MessageV1 {
 			chain_id: CHAIN_ID,
@@ -536,7 +538,7 @@ fn register_weth_token_in_asset_hub_fail_for_insufficient_fee() {
 				fee: INSUFFICIENT_XCM_FEE,
 			},
 		});
-		let (xcm, _) = EthereumInboundQueue::do_convert(message_id, message).unwrap();
+		let (xcm, _) = Converter::convert(message_id, message).unwrap();
 		let _ = EthereumInboundQueue::send_xcm(xcm, AssetHubRococo::para_id().into()).unwrap();
 
 		assert_expected_events!(
@@ -553,7 +555,7 @@ fn register_weth_token_in_asset_hub_fail_for_insufficient_fee() {
 		assert_expected_events!(
 			AssetHubRococo,
 			vec![
-				RuntimeEvent::MessageQueue(pallet_message_queue::Event::Processed { success:false, .. }) => {},
+				RuntimeEvent::MessageQueue(pallet_message_queue::Event::Processed { success:false, .. }) => { },
 			]
 		);
 	});