Bridge hub kusama polkadot with dynamic fees

Cargo.toml

@@ -7,6 +7,7 @@ members = [
 	"bridges/modules/messages",
 	"bridges/modules/parachains",
 	"bridges/modules/relayers",
+	"bridges/modules/xcm-bridge-hub-router",
 	"client/cli",
 	"client/collator",
 	"client/consensus/aura",

pallets/xcmp-queue/Cargo.toml

@@ -28,6 +28,9 @@ cumulus-primitives-core = { path = "../../primitives/core", default-features = f
 # Optional import for benchmarking
 frame-benchmarking = { default-features = false, optional = true, git = "https://github.com/paritytech/substrate", branch = "master" }
 
+# Bridges
+bp-xcm-bridge-hub-router = { path = "../../bridges/primitives/xcm-bridge-hub-router", default-features = false, optional = true }
+
 [dev-dependencies]
 
 # Substrate
@@ -55,6 +58,7 @@ std = [
 	"sp-std/std",
 	"xcm-executor/std",
 	"xcm/std",
+	"bp-xcm-bridge-hub-router/std",
 ]
 
 runtime-benchmarks = [
@@ -64,3 +68,7 @@ runtime-benchmarks = [
 	"xcm-builder/runtime-benchmarks",
 ]
 try-runtime = ["frame-support/try-runtime"]
+
+bridging = [
+	"bp-xcm-bridge-hub-router",
+]

pallets/xcmp-queue/src/bridging.rs

@@ -0,0 +1,111 @@
+// 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.
+
+use crate::pallet;
+use cumulus_primitives_core::ParaId;
+use frame_support::pallet_prelude::Get;
+
+/// Adapter implementation for `bp_xcm_bridge_hub_router::XcmChannelStatusProvider` which checks
+/// both `OutboundXcmpStatus` and `InboundXcmpStatus` for defined `ParaId` if any of those is
+/// suspended.
+pub struct InboundAndOutboundXcmpChannelCongestionStatusProvider<SiblingBridgeHubParaId, Runtime>(
+	sp_std::marker::PhantomData<(SiblingBridgeHubParaId, Runtime)>,
+);
+impl<SiblingBridgeHubParaId: Get<ParaId>, Runtime: crate::Config>
+	bp_xcm_bridge_hub_router::XcmChannelStatusProvider
+	for InboundAndOutboundXcmpChannelCongestionStatusProvider<SiblingBridgeHubParaId, Runtime>
+{
+	fn is_congested() -> bool {
+		// if the outbound channel with recipient is suspended, it means that one of further
+		// bridge queues (e.g. bridge queue between two bridge hubs) is overloaded, so we shall
+		// take larger fee for our outbound messages
+		let sibling_bridge_hub_id: ParaId = SiblingBridgeHubParaId::get();
+		let outbound_channels = pallet::OutboundXcmpStatus::<Runtime>::get();
+		let outbound_channel =
+			outbound_channels.iter().find(|c| c.recipient == sibling_bridge_hub_id);
+		let is_outbound_channel_suspended =
+			outbound_channel.map(|c| c.is_suspended()).unwrap_or(false);
+		if is_outbound_channel_suspended {
+			return true
+		}
+
+		// if the inbound channel with recipient is suspended, it means that we are unable to
+		// receive congestion reports from the bridge hub. So we assume the bridge pipeline is
+		// congested too
+		let inbound_channels = pallet::InboundXcmpStatus::<Runtime>::get();
+		let inbound_channel = inbound_channels.iter().find(|c| c.sender == sibling_bridge_hub_id);
+		let is_inbound_channel_suspended =
+			inbound_channel.map(|c| c.is_suspended()).unwrap_or(false);
+		if is_inbound_channel_suspended {
+			return true
+		}
+
+		// TODO: https://github.com/paritytech/cumulus/pull/2342 - once this PR is merged, we may
+		// remove the following code
+		//
+		// if the outbound channel has at least `N` pages enqueued, let's assume it is congested.
+		// Normally, the chain with a few opened HRMP channels, will "send" pages at every block.
+		// Having `N` pages means that for last `N` blocks we either have not sent any messages,
+		// or have sent signals.
+		const MAX_OUTBOUND_PAGES_BEFORE_CONGESTION: u16 = 4;
+		let is_outbound_channel_congested = outbound_channel.map(|c| c.queued_pages()).unwrap_or(0);
+		is_outbound_channel_congested > MAX_OUTBOUND_PAGES_BEFORE_CONGESTION
+	}
+}
+
+/// Adapter implementation for `bp_xcm_bridge_hub_router::XcmChannelStatusProvider` which checks
+/// only `OutboundXcmpStatus` for defined `SiblingParaId` if is suspended.
+pub struct OutboundXcmpChannelCongestionStatusProvider<SiblingBridgeHubParaId, Runtime>(
+	sp_std::marker::PhantomData<(SiblingBridgeHubParaId, Runtime)>,
+);
+impl<SiblingParaId: Get<ParaId>, Runtime: crate::Config>
+	bp_xcm_bridge_hub_router::XcmChannelStatusProvider
+	for OutboundXcmpChannelCongestionStatusProvider<SiblingParaId, Runtime>
+{
+	fn is_congested() -> bool {
+		// let's find the channel with the sibling parachain
+		let sibling_para_id: cumulus_primitives_core::ParaId = SiblingParaId::get();
+		let outbound_channels = pallet::OutboundXcmpStatus::<Runtime>::get();
+		let channel_with_sibling_parachain =
+			outbound_channels.iter().find(|c| c.recipient == sibling_para_id);
+
+		// no channel => it is empty, so not congested
+		let channel_with_sibling_parachain = match channel_with_sibling_parachain {
+			Some(channel_with_sibling_parachain) => channel_with_sibling_parachain,
+			None => return false,
+		};
+
+		// suspended channel => it is congested
+		if channel_with_sibling_parachain.is_suspended() {
+			return true
+		}
+
+		// TODO: the following restriction is arguable, we may live without that, assuming that
+		// there can't be more than some `N` messages queued at the bridge queue (at the source BH)
+		// AND before accepting next (or next-after-next) delivery transaction, we'll receive the
+		// suspension signal from the target parachain and stop accepting delivery transactions
+
+		// it takes some time for target parachain to suspend inbound channel with the target BH and
+		// during that we will keep accepting new message delivery transactions. Let's also reject
+		// new deliveries if there are too many "pages" (concatenated XCM messages) in the target BH
+		// -> target parachain queue.
+		const MAX_QUEUED_PAGES_BEFORE_DEACTIVATION: u16 = 4;
+		if channel_with_sibling_parachain.queued_pages() > MAX_QUEUED_PAGES_BEFORE_DEACTIVATION {
+			return true
+		}
+
+		true
+	}
+}

pallets/xcmp-queue/src/lib.rs

@@ -35,6 +35,8 @@ mod tests;
 
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmarking;
+#[cfg(feature = "bridging")]
+pub mod bridging;
 pub mod weights;
 pub use weights::WeightInfo;
 
@@ -400,6 +402,13 @@ pub struct InboundChannelDetails {
 	message_metadata: Vec<(RelayBlockNumber, XcmpMessageFormat)>,
 }
 
+impl InboundChannelDetails {
+	#[cfg(feature = "bridging")]
+	pub(crate) fn is_suspended(&self) -> bool {
+		self.state == InboundState::Suspended
+	}
+}
+
 /// Struct containing detailed information about the outbound channel.
 #[derive(Clone, Eq, PartialEq, Encode, Decode, TypeInfo)]
 pub struct OutboundChannelDetails {
@@ -435,6 +444,16 @@ impl OutboundChannelDetails {
 		self.state = OutboundState::Suspended;
 		self
 	}
+
+	#[cfg(feature = "bridging")]
+	pub(crate) fn is_suspended(&self) -> bool {
+		self.state == OutboundState::Suspended
+	}
+
+	#[cfg(feature = "bridging")]
+	pub(crate) fn queued_pages(&self) -> u16 {
+		self.last_index.saturating_sub(self.first_index)
+	}
 }
 
 #[derive(Copy, Clone, Eq, PartialEq, Encode, Decode, RuntimeDebug, TypeInfo)]

parachains/runtimes/bridge-hubs/README.md

@@ -269,7 +269,9 @@ This initialization does several things:
 - drips SA for AssetHubKusama on AssetHubPolkadot (and vice versa) which holds reserved assets on source chains
 ```
 ./scripts/bridges_kusama_polkadot.sh init-asset-hub-kusama-local
+./scripts/bridges_kusama_polkadot.sh init-bridge-hub-kusama-local
 ./scripts/bridges_kusama_polkadot.sh init-asset-hub-polkadot-local
+./scripts/bridges_kusama_polkadot.sh init-bridge-hub-polkadot-local
 ```
 
 ### 4. Send messages - transfer asset over bridge (DOTs/KSMs)

parachains/runtimes/bridge-hubs/bridge-hub-kusama/Cargo.toml

@@ -63,7 +63,7 @@ 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 }
@@ -72,6 +72,7 @@ parachain-info = { path = "../../../../parachains/pallets/parachain-info", defau
 parachains-common = { path = "../../../../parachains/common", default-features = false }
 
 # Bridges
+bp-asset-hub-kusama = { path = "../../../../bridges/primitives/chain-asset-hub-kusama", default-features = false }
 bp-bridge-hub-kusama = { path = "../../../../bridges/primitives/chain-bridge-hub-kusama", default-features = false }
 bp-bridge-hub-polkadot = { path = "../../../../bridges/primitives/chain-bridge-hub-polkadot", default-features = false }
 bp-header-chain = { path = "../../../../bridges/primitives/header-chain", default-features = false }
@@ -99,6 +100,7 @@ default = [
 	"std",
 ]
 std = [
+	"bp-asset-hub-kusama/std",
 	"bp-bridge-hub-kusama/std",
 	"bp-bridge-hub-polkadot/std",
 	"bp-header-chain/std",

parachains/runtimes/bridge-hubs/bridge-hub-kusama/src/bridge_hub_config.rs

@@ -33,6 +33,7 @@ use bridge_runtime_common::{
 		RefundableParachain,
 	},
 };
+use codec::Encode;
 use frame_support::{parameter_types, traits::PalletInfoAccess, RuntimeDebug};
 use xcm::{latest::prelude::*, prelude::NetworkId};
 use xcm_builder::{BridgeBlobDispatcher, HaulBlobExporter};
@@ -54,6 +55,28 @@ parameter_types! {
 		ParentThen(X1(Parachain(AssetHubKusamaParaId::get().into()))).into(),
 		ASSET_HUB_KUSAMA_TO_ASSET_HUB_POLKADOT_LANE_ID,
 	);
+
+	pub CongestedMessage: Xcm<()> = sp_std::vec![Transact {
+		origin_kind: OriginKind::Xcm,
+		require_weight_at_most: bp_asset_hub_kusama::XcmBridgeHubRouterTransactCallMaxWeight::get(),
+		call: bp_asset_hub_kusama::Call::ToPolkadotXcmRouter(
+			bp_asset_hub_kusama::XcmBridgeHubRouterCall::report_bridge_status {
+				bridge_id: Default::default(),
+				is_congested: true,
+			}
+		).encode().into(),
+	}].into();
+
+	pub UncongestedMessage: Xcm<()> = sp_std::vec![Transact {
+		origin_kind: OriginKind::Xcm,
+		require_weight_at_most: bp_asset_hub_kusama::XcmBridgeHubRouterTransactCallMaxWeight::get(),
+		call: bp_asset_hub_kusama::Call::ToPolkadotXcmRouter(
+			bp_asset_hub_kusama::XcmBridgeHubRouterCall::report_bridge_status {
+				bridge_id: Default::default(),
+				is_congested: false,
+			}
+		).encode().into(),
+	}].into();
 }
 
 /// Proof of messages, coming from BridgeHubPolkadot.
@@ -80,10 +103,13 @@ impl XcmBlobHauler for ToBridgeHubPolkadotXcmBlobHauler {
 	type SenderAndLane = FromAssetHubKusamaToAssetHubPolkadotRoute;
 
 	type ToSourceChainSender = crate::XcmRouter;
-	type CongestedMessage = ();
-	type UncongestedMessage = ();
+	type CongestedMessage = CongestedMessage;
+	type UncongestedMessage = UncongestedMessage;
 }
 
+/// On messages delivered callback.
+pub type OnMessagesDelivered = XcmBlobHaulerAdapter<ToBridgeHubPolkadotXcmBlobHauler>;
+
 /// Messaging Bridge configuration for ThisChain -> BridgeHubPolkadot
 pub struct WithBridgeHubPolkadotMessageBridge;
 impl MessageBridge for WithBridgeHubPolkadotMessageBridge {

parachains/runtimes/bridge-hubs/bridge-hub-kusama/src/lib.rs

@@ -485,9 +485,15 @@ impl pallet_bridge_messages::Config<WithBridgeHubPolkadotMessagesInstance> for R
 		DeliveryRewardInBalance,
 	>;
 	type SourceHeaderChain = SourceHeaderChainAdapter<WithBridgeHubPolkadotMessageBridge>;
-	type MessageDispatch =
-		XcmBlobMessageDispatch<OnThisChainBlobDispatcher<UniversalLocation>, Self::WeightInfo, ()>;
-	type OnMessagesDelivered = ();
+	type MessageDispatch = XcmBlobMessageDispatch<
+		OnThisChainBlobDispatcher<UniversalLocation>,
+		Self::WeightInfo,
+		cumulus_pallet_xcmp_queue::bridging::OutboundXcmpChannelCongestionStatusProvider<
+			bridge_hub_config::AssetHubKusamaParaId,
+			Runtime,
+		>,
+	>;
+	type OnMessagesDelivered = bridge_hub_config::OnMessagesDelivered;
 }
 
 /// Allows collect and claim rewards for relayers

parachains/runtimes/bridge-hubs/bridge-hub-kusama/src/xcm_config.rs

@@ -112,12 +112,6 @@ match_types! {
 		MultiLocation { parents: 1, interior: Here } |
 		MultiLocation { parents: 1, interior: X1(_) }
 	};
-	// TODO:check-parameter - (https://github.com/paritytech/parity-bridges-common/issues/2084)
-	// remove this and extend `AllowExplicitUnpaidExecutionFrom` with "or SystemParachains" once merged https://github.com/paritytech/polkadot/pull/7005
-	pub type SystemParachains: impl Contains<MultiLocation> = {
-		// Statemine
-		MultiLocation { parents: 1, interior: X1(Parachain(1000)) }
-	};
 }
 
 /// A call filter for the XCM Transact instruction. This is a temporary measure until we properly
@@ -191,9 +185,8 @@ pub type Barrier = TrailingSetTopicAsId<
 					// If the message is one that immediately attemps to pay for execution, then
 					// allow it.
 					AllowTopLevelPaidExecutionFrom<Everything>,
-					// Parent, its pluralities (i.e. governance bodies) and system parachains get
-					// free execution.
-					AllowExplicitUnpaidExecutionFrom<(ParentOrParentsPlurality, SystemParachains)>,
+					// Parent and its pluralities (i.e. governance bodies) get free execution.
+					AllowExplicitUnpaidExecutionFrom<(ParentOrParentsPlurality,)>,
 					// Subscriptions for version tracking are OK.
 					AllowSubscriptionsFrom<ParentOrSiblings>,
 				),