Adding paid xcm bridge hub router to AssetHubPolkadot

parachains/runtimes/assets/asset-hub-kusama/src/xcm_config.rs

@@ -482,7 +482,7 @@ type LocalXcmRouter = (
 /// queues.
 pub type XcmRouter = WithUniqueTopic<(
 	LocalXcmRouter,
-	// Router, which wraps and sends xcm to BridgeHub to be delivered to the Polkadot GlobalConsensus
+	// Router which wraps and sends xcm to BridgeHub to be delivered to the Polkadot GlobalConsensus
 	ToPolkadotXcmRouter,
 )>;
 

parachains/runtimes/assets/asset-hub-polkadot/Cargo.toml

@@ -65,7 +65,7 @@ cumulus-pallet-dmp-queue = { path = "../../../../pallets/dmp-queue", default-fea
 cumulus-pallet-parachain-system = { path = "../../../../pallets/parachain-system", default-features = false }
 cumulus-pallet-session-benchmarking = { path = "../../../../pallets/session-benchmarking", default-features = false, version = "3.0.0" }
 cumulus-pallet-xcm = { path = "../../../../pallets/xcm", default-features = false }
-cumulus-pallet-xcmp-queue = { path = "../../../../pallets/xcmp-queue", default-features = false }
+cumulus-pallet-xcmp-queue = { path = "../../../../pallets/xcmp-queue", default-features = false, features = ["bridging"] }
 cumulus-primitives-core = { path = "../../../../primitives/core", default-features = false }
 cumulus-primitives-timestamp = { path = "../../../../primitives/timestamp", default-features = false }
 cumulus-primitives-utility = { path = "../../../../primitives/utility", default-features = false }
@@ -74,6 +74,9 @@ parachain-info = { path = "../../../pallets/parachain-info", default-features =
 parachains-common = { path = "../../../common", default-features = false }
 assets-common = { path = "../common", default-features = false }
 
+# Bridges
+pallet-xcm-bridge-hub-router = { path = "../../../../bridges/modules/xcm-bridge-hub-router", default-features = false }
+
 [dev-dependencies]
 hex-literal = "0.4.1"
 asset-test-utils = { path = "../test-utils"}
@@ -107,6 +110,7 @@ runtime-benchmarks = [
 	"cumulus-pallet-xcmp-queue/runtime-benchmarks",
 	"pallet-xcm-benchmarks/runtime-benchmarks",
 	"assets-common/runtime-benchmarks",
+	"pallet-xcm-bridge-hub-router/runtime-benchmarks",
 ]
 try-runtime = [
 	"cumulus-pallet-aura-ext/try-runtime",
@@ -133,6 +137,7 @@ try-runtime = [
 	"pallet-utility/try-runtime",
 	"pallet-xcm/try-runtime",
 	"parachain-info/try-runtime",
+	"pallet-xcm-bridge-hub-router/try-runtime",
 ]
 std = [
 	"codec/std",
@@ -188,5 +193,6 @@ std = [
 	"parachain-info/std",
 	"parachains-common/std",
 	"assets-common/std",
+	"pallet-xcm-bridge-hub-router/std",
 	"substrate-wasm-builder",
 ]

parachains/runtimes/assets/asset-hub-polkadot/src/lib.rs

@@ -720,6 +720,27 @@ impl pallet_nfts::Config for Runtime {
 	type Helper = ();
 }
 
+/// XCM router instance to BridgeHub with bridging capabilities for `Kusama` global consensus with dynamic fees and back-pressure.
+pub type ToKusamaXcmRouterInstance = pallet_assets::Instance1;
+impl pallet_xcm_bridge_hub_router::Config<ToKusamaXcmRouterInstance> for Runtime {
+	type WeightInfo = (); // TODO: proper weights
+
+	type UniversalLocation = xcm_config::UniversalLocation;
+	type BridgedNetworkId = xcm_config::bridging::KusamaNetwork;
+	type Bridges = xcm_config::bridging::FilteredNetworkExportTable;
+
+	type BridgeHubOrigin = EnsureXcm<Equals<xcm_config::bridging::BridgeHubPolkadot>>;
+	type ToBridgeHubSender = XcmpQueue;
+	type WithBridgeHubChannel =
+		cumulus_pallet_xcmp_queue::bridging::InboundAndOutboundXcmpChannelCongestionStatusProvider<
+			xcm_config::bridging::BridgeHubPolkadotParaId,
+			Runtime,
+		>;
+
+	type ByteFee = xcm_config::bridging::XcmBridgeHubRouterByteFee;
+	type FeeAsset = xcm_config::bridging::XcmBridgeHubRouterFeeAssetId;
+}
+
 // Create the runtime by composing the FRAME pallets that were previously configured.
 construct_runtime!(
 	pub enum Runtime
@@ -756,6 +777,9 @@ construct_runtime!(
 		Multisig: pallet_multisig::{Pallet, Call, Storage, Event<T>} = 41,
 		Proxy: pallet_proxy::{Pallet, Call, Storage, Event<T>} = 42,
 
+		// Bridge utilities.
+		ToPolkadotXcmRouter: pallet_xcm_bridge_hub_router::<Instance1>::{Pallet, Storage, Call} = 43,
+
 		// The main stage.
 		Assets: pallet_assets::<Instance1>::{Pallet, Call, Storage, Event<T>} = 50,
 		Uniques: pallet_uniques::{Pallet, Call, Storage, Event<T>} = 51,

parachains/runtimes/assets/asset-hub-polkadot/src/xcm_config.rs

@@ -16,7 +16,7 @@
 use super::{
 	AccountId, AllPalletsWithSystem, Assets, Authorship, Balance, Balances, ForeignAssets,
 	ParachainInfo, ParachainSystem, PolkadotXcm, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin,
-	TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
+	ToKusamaXcmRouter, TransactionByteFee, TrustBackedAssetsInstance, WeightToFee, XcmpQueue,
 };
 use crate::ForeignAssetsInstance;
 use assets_common::matching::{
@@ -207,6 +207,14 @@ impl Contains<RuntimeCall> for SafeCallFilter {
 			}
 		}
 
+		// Allow to change dedicated storage items (called by governance-like)
+		match call {
+			RuntimeCall::System(frame_system::Call::set_storage { items })
+				if items.iter().any(|(k, _)| k.eq(&bridging::XcmBridgeHubRouterByteFee::key())) =>
+				return true,
+			_ => (),
+		};
+
 		matches!(
 			call,
 			RuntimeCall::PolkadotXcm(pallet_xcm::Call::force_xcm_version { .. }) |
@@ -460,6 +468,7 @@ impl xcm_executor::Config for XcmConfig {
 	type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
 	type AssetLocker = ();
 	type AssetExchanger = ();
+	// TODO:check-parameter: change and assert in tests when (https://github.com/paritytech/polkadot/pull/7005) merged
 	type FeeManager = ();
 	type MessageExporter = ();
 	type UniversalAliases = bridging::UniversalAliases;
@@ -482,7 +491,11 @@ type LocalXcmRouter = (
 
 /// The means for routing XCM messages which are not for local execution into the right message
 /// queues.
-pub type XcmRouter = WithUniqueTopic<(LocalXcmRouter, bridging::BridgingXcmRouter)>;
+pub type XcmRouter = WithUniqueTopic<(
+	LocalXcmRouter,
+	// Router which wraps and sends XCM to BridgeHub to be delivered to the Kusama GlobalConsensus
+	ToKusamaXcmRouter,
+)>;
 
 #[cfg(feature = "runtime-benchmarks")]
 parameter_types! {
@@ -577,7 +590,14 @@ pub mod bridging {
 		pub AssetHubKusama: MultiLocation =  MultiLocation::new(2, X2(GlobalConsensus(KusamaNetwork::get()), Parachain(1000)));
 		pub KsmLocation: MultiLocation =  MultiLocation::new(2, X1(GlobalConsensus(KusamaNetwork::get())));
 
+		/// Router expects payment with this `AssetId`.
+		/// (`AssetId` has to be aligned with `BridgeTable`)
+		pub XcmBridgeHubRouterFeeAssetId: AssetId = DotLocation::get().into();
+		/// Price per byte - can be adjusted via governance `set_storage` call.
+		pub storage XcmBridgeHubRouterByteFee: Balance = TransactionByteFee::get();
+
 		/// Set up exporters configuration.
+		/// `Option<MultiAsset>` represents static "base fee" which is used for total delivery fee calculation.
 		pub BridgeTable: sp_std::vec::Vec<(NetworkId, LocationFilter<InteriorMultiLocation>, MultiLocation, Option<MultiAsset>)> = sp_std::vec![
 			(
 				KusamaNetwork::get(),
@@ -586,7 +606,9 @@ pub mod bridging {
 					.add_equals(AssetHubKusama::get().interior.split_global().expect("invalid configuration for AssetHubKusama").1),
 					// and nothing else
 				BridgeHubPolkadot::get(),
-				None
+				// base delivery fee to local `BridgeHub`
+				// (initially was calculated `51220000` + 10% by test `BridgeHubPolkadot::can_calculate_weight_for_paid_export_message_with_reserve_transfer`)
+				Some((XcmBridgeHubRouterFeeAssetId::get(), 56342000).into())
 			)
 		];
 
@@ -637,10 +659,6 @@ pub mod bridging {
 	pub type FilteredNetworkExportTable =
 		parachains_common::xcm_config::FilteredNetworkExportTable<BridgeTable>;
 
-	/// Bridge router, which wraps and sends xcm to BridgeHub to be delivered to the different GlobalConsensus
-	pub type BridgingXcmRouter =
-		UnpaidRemoteExporter<FilteredNetworkExportTable, LocalXcmRouter, UniversalLocation>;
-
 	/// Reserve locations filter for `xcm_executor::Config::IsReserve`.
 	pub type IsTrustedBridgedReserveLocationForConcreteAsset =
 		matching::IsTrustedBridgedReserveLocationForConcreteAsset<

parachains/runtimes/assets/asset-hub-polkadot/tests/tests.rs

@@ -692,7 +692,7 @@ fn limited_reserve_transfer_assets_for_native_asset_over_bridge_works() {
 		}),
 		bridging_to_asset_hub_kusama,
 		WeightLimit::Unlimited,
-		None,
+		Some(xcm_config::bridging::XcmBridgeHubRouterFeeAssetId::get()),
 	)
 }
 
@@ -799,3 +799,29 @@ fn xcm_reserve_transfer_filter_works() {
 			}
 		})
 }
+
+#[test]
+fn change_xcm_bridge_hub_router_byte_fee_by_governance_works() {
+	asset_test_utils::test_cases::change_storage_constant_by_governance_works::<
+		Runtime,
+		bridging::XcmBridgeHubRouterByteFee,
+		Balance,
+	>(
+		collator_session_keys(),
+		1000,
+		Box::new(|call| RuntimeCall::System(call).encode()),
+		|| {
+			(
+				bridging::XcmBridgeHubRouterByteFee::key().to_vec(),
+				bridging::XcmBridgeHubRouterByteFee::get(),
+			)
+		},
+		|old_value| {
+			if let Some(new_value) = old_value.checked_add(1) {
+				new_value
+			} else {
+				old_value.checked_sub(1).unwrap()
+			}
+		},
+	)
+}