Add commons crate for BridgeHub runtime

Cargo.toml

@@ -83,6 +83,7 @@ members = [
 	"cumulus/parachains/runtimes/bridge-hubs/bridge-hub-polkadot",
 	"cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo",
 	"cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend",
+	"cumulus/parachains/runtimes/bridge-hubs/common",
 	"cumulus/parachains/runtimes/bridge-hubs/test-utils",
 	"cumulus/parachains/runtimes/collectives/collectives-polkadot",
 	"cumulus/parachains/runtimes/contracts/contracts-rococo",

cumulus/parachains/runtimes/bridge-hubs/common/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name = "bridge-hub-common"
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+description = "Bridge hub common utilities"
+license = "Apache-2.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
+scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+cumulus-primitives-core = { path = "../../../../primitives/core", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false}
+
+
+[features]
+default = [ "std" ]
+std = [
+	"codec/std",
+	"scale-info/std",
+	"frame-support/std",
+	"sp-std/std",
+	"sp-runtime/std",
+	"cumulus-primitives-core/std",
+	"xcm/std"
+]
+
+runtime-benchmarks = [
+	"frame-support/runtime-benchmarks",
+	"cumulus-primitives-core/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks"
+]

cumulus/parachains/runtimes/bridge-hubs/common/src/lib.rs

@@ -0,0 +1,19 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod message_queue;
+
+pub use message_queue::{AggregateMessageOrigin, BridgeHubMessageRouter};

cumulus/parachains/runtimes/bridge-hubs/common/src/message_queue.rs

@@ -0,0 +1,107 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//! Runtime configuration for MessageQueue pallet
+use sp_std::{prelude::*, marker::PhantomData};
+use codec::{Decode, Encode, MaxEncodedLen};
+use frame_support::{weights::WeightMeter, traits::{ProcessMessage, ProcessMessageError}};
+use scale_info::TypeInfo;
+use cumulus_primitives_core::ParaId;
+use xcm::v3::{MultiLocation, Junction};
+
+/// The aggregate origin of an inbound message.
+/// This is specialized for BridgeHub, as the snowbridge-outbound-queue pallet is also using
+/// the shared MessageQueue pallet.
+#[derive(Encode, Decode, MaxEncodedLen, Clone, Eq, PartialEq, TypeInfo, Debug)]
+pub enum AggregateMessageOrigin {
+	/// The message came from the para-chain itself.
+	Here,
+	/// The message came from the relay-chain.
+	///
+	/// This is used by the DMP queue.
+	Parent,
+	/// The message came from a sibling para-chain.
+	///
+	/// This is used by the HRMP queue.
+	Sibling(ParaId),
+	Snowbridge(SnowbridgeMessageOrigin),
+}
+
+/// The origin of an inbound message for Snowbridge.
+#[derive(Encode, Decode, MaxEncodedLen, Clone, Eq, PartialEq, TypeInfo, Debug)]
+pub enum SnowbridgeMessageOrigin {
+	/// The message came from the para-chain itself.
+	Here,
+	/// The message came from a sibling para-chain.
+	Sibling(ParaId),
+}
+
+impl From<AggregateMessageOrigin> for MultiLocation {
+	fn from(origin: AggregateMessageOrigin) -> Self {
+		use AggregateMessageOrigin::*;
+		match origin {
+			Here => MultiLocation::here(),
+			Parent => MultiLocation::parent(),
+			Sibling(id) =>
+				MultiLocation::new(1, Junction::Parachain(id.into())),
+			// NOTE: We don't need this conversion for Snowbridge. However we have to
+			// implement it anyway as xcm_builder::ProcessXcmMessage requires it.
+			Snowbridge(_) => MultiLocation::default(),
+		}
+	}
+}
+
+#[cfg(feature = "runtime-benchmarks")]
+impl From<u32> for AggregateMessageOrigin {
+	fn from(x: u32) -> Self {
+		match x {
+			0 => Self::Here,
+			1 => Self::Parent,
+			p => Self::Sibling(ParaId::from(p)),
+		}
+	}
+}
+
+/// Routes messages to either the XCMP or Snowbridge processor.
+pub struct BridgeHubMessageRouter<XcmpProcessor, SnowbridgeProcessor>(PhantomData<(XcmpProcessor, SnowbridgeProcessor)>)
+where
+	XcmpProcessor: ProcessMessage<Origin = AggregateMessageOrigin>,
+	SnowbridgeProcessor: ProcessMessage<Origin = AggregateMessageOrigin>;
+
+impl<
+	XcmpProcessor,
+	SnowbridgeProcessor
+> ProcessMessage for BridgeHubMessageRouter<
+	XcmpProcessor,
+	SnowbridgeProcessor
+>
+where
+	XcmpProcessor: ProcessMessage<Origin = AggregateMessageOrigin>,
+	SnowbridgeProcessor: ProcessMessage<Origin = AggregateMessageOrigin>
+{
+	type Origin = AggregateMessageOrigin;
+
+	fn process_message(
+		message: &[u8],
+		origin: Self::Origin,
+		meter: &mut WeightMeter,
+		id: &mut [u8; 32],
+	) -> Result<bool, ProcessMessageError> {
+		use AggregateMessageOrigin::*;
+		match origin {
+			Here | Parent | Sibling(_) => XcmpProcessor::process_message(message, origin, meter, id),
+			Snowbridge(_) => SnowbridgeProcessor::process_message(message, origin, meter, id)
+		}
+	}
+}