Bridges subtree sync (#3022)

* Squashed 'bridges/' changes from edf33a2c85..277f0d5496

277f0d5496 Dynamic fees for bridges-v1 (#2294)
b1c51f7dd2 Finality loop refactoring (#2357)
620db2b10f Add equivocation detector crate and implement clients (#2348) (#2353)
3fe4b13eb4 Add basic equivocation detection pipeline schema (#2338) (#2341)

git-subtree-dir: bridges
git-subtree-split: 277f0d54961c800b231d8123c6445f378b1deb89

* [dynfees] Rococo/Wococo does not need congestion and dynamic fees (for now)

* Fix

* ".git/.scripts/commands/fmt/fmt.sh"

* Forgotten bridges/Cargo.lock

---------

Co-authored-by: command-bot <>

cumulus/bridges/modules/grandpa/src/lib.rs

@@ -40,10 +40,10 @@ pub use storage_types::StoredAuthoritySet;
 
 use bp_header_chain::{
 	justification::GrandpaJustification, AuthoritySet, ChainWithGrandpa, GrandpaConsensusLogReader,
-	HeaderChain, HeaderGrandpaInfo, InitializationData, StoredHeaderData, StoredHeaderDataBuilder,
+	HeaderChain, InitializationData, StoredHeaderData, StoredHeaderDataBuilder,
+	StoredHeaderGrandpaInfo,
 };
 use bp_runtime::{BlockNumberOf, HashOf, HasherOf, HeaderId, HeaderOf, OwnedBridgeModule};
-use finality_grandpa::voter_set::VoterSet;
 use frame_support::{dispatch::PostDispatchInfo, ensure, DefaultNoBound};
 use sp_runtime::{
 	traits::{Header as HeaderT, Zero},
@@ -241,9 +241,9 @@ pub mod pallet {
 			Self::deposit_event(Event::UpdatedBestFinalizedHeader {
 				number,
 				hash,
-				grandpa_info: HeaderGrandpaInfo {
-					justification,
-					authority_set: maybe_new_authority_set,
+				grandpa_info: StoredHeaderGrandpaInfo {
+					finality_proof: justification,
+					new_verification_context: maybe_new_authority_set,
 				},
 			});
 
@@ -411,7 +411,7 @@ pub mod pallet {
 			number: BridgedBlockNumber<T, I>,
 			hash: BridgedBlockHash<T, I>,
 			/// The Grandpa info associated to the new best finalized header.
-			grandpa_info: HeaderGrandpaInfo<BridgedHeader<T, I>>,
+			grandpa_info: StoredHeaderGrandpaInfo<BridgedHeader<T, I>>,
 		},
 	}
 
@@ -505,14 +505,9 @@ pub mod pallet {
 	) -> Result<(), sp_runtime::DispatchError> {
 		use bp_header_chain::justification::verify_justification;
 
-		let voter_set =
-			VoterSet::new(authority_set.authorities).ok_or(<Error<T, I>>::InvalidAuthoritySet)?;
-		let set_id = authority_set.set_id;
-
 		Ok(verify_justification::<BridgedHeader<T, I>>(
 			(hash, number),
-			set_id,
-			&voter_set,
+			&authority_set.try_into().map_err(|_| <Error<T, I>>::InvalidAuthoritySet)?,
 			justification,
 		)
 		.map_err(|e| {
@@ -617,7 +612,7 @@ where
 	<T as frame_system::Config>::RuntimeEvent: TryInto<Event<T, I>>,
 {
 	/// Get the GRANDPA justifications accepted in the current block.
-	pub fn synced_headers_grandpa_info() -> Vec<HeaderGrandpaInfo<BridgedHeader<T, I>>> {
+	pub fn synced_headers_grandpa_info() -> Vec<StoredHeaderGrandpaInfo<BridgedHeader<T, I>>> {
 		frame_system::Pallet::<T>::read_events_no_consensus()
 			.filter_map(|event| {
 				if let Event::<T, I>::UpdatedBestFinalizedHeader { grandpa_info, .. } =
@@ -934,9 +929,9 @@ mod tests {
 					event: TestEvent::Grandpa(Event::UpdatedBestFinalizedHeader {
 						number: *header.number(),
 						hash: header.hash(),
-						grandpa_info: HeaderGrandpaInfo {
-							justification: justification.clone(),
-							authority_set: None,
+						grandpa_info: StoredHeaderGrandpaInfo {
+							finality_proof: justification.clone(),
+							new_verification_context: None,
 						},
 					}),
 					topics: vec![],
@@ -944,7 +939,10 @@ mod tests {
 			);
 			assert_eq!(
 				Pallet::<TestRuntime>::synced_headers_grandpa_info(),
-				vec![HeaderGrandpaInfo { justification, authority_set: None }]
+				vec![StoredHeaderGrandpaInfo {
+					finality_proof: justification,
+					new_verification_context: None
+				}]
 			);
 		})
 	}
@@ -1075,9 +1073,11 @@ mod tests {
 					event: TestEvent::Grandpa(Event::UpdatedBestFinalizedHeader {
 						number: *header.number(),
 						hash: header.hash(),
-						grandpa_info: HeaderGrandpaInfo {
-							justification: justification.clone(),
-							authority_set: Some(<CurrentAuthoritySet<TestRuntime>>::get().into()),
+						grandpa_info: StoredHeaderGrandpaInfo {
+							finality_proof: justification.clone(),
+							new_verification_context: Some(
+								<CurrentAuthoritySet<TestRuntime>>::get().into()
+							),
 						},
 					}),
 					topics: vec![],
@@ -1085,9 +1085,11 @@ mod tests {
 			);
 			assert_eq!(
 				Pallet::<TestRuntime>::synced_headers_grandpa_info(),
-				vec![HeaderGrandpaInfo {
-					justification,
-					authority_set: Some(<CurrentAuthoritySet<TestRuntime>>::get().into()),
+				vec![StoredHeaderGrandpaInfo {
+					finality_proof: justification,
+					new_verification_context: Some(
+						<CurrentAuthoritySet<TestRuntime>>::get().into()
+					),
 				}]
 			);
 		})

cumulus/bridges/modules/messages/src/lib.rs

@@ -53,7 +53,8 @@ use crate::{
 
 use bp_messages::{
 	source_chain::{
-		DeliveryConfirmationPayments, LaneMessageVerifier, SendMessageArtifacts, TargetHeaderChain,
+		DeliveryConfirmationPayments, LaneMessageVerifier, OnMessagesDelivered,
+		SendMessageArtifacts, TargetHeaderChain,
 	},
 	target_chain::{
 		DeliveryPayments, DispatchMessage, MessageDispatch, ProvedLaneMessages, ProvedMessages,
@@ -63,7 +64,9 @@ use bp_messages::{
 	MessagePayload, MessagesOperatingMode, OutboundLaneData, OutboundMessageDetails,
 	UnrewardedRelayersState, VerificationError,
 };
-use bp_runtime::{BasicOperatingMode, ChainId, OwnedBridgeModule, PreComputedSize, Size};
+use bp_runtime::{
+	BasicOperatingMode, ChainId, OwnedBridgeModule, PreComputedSize, RangeInclusiveExt, Size,
+};
 use codec::{Decode, Encode, MaxEncodedLen};
 use frame_support::{dispatch::PostDispatchInfo, ensure, fail, traits::Get, DefaultNoBound};
 use sp_runtime::traits::UniqueSaturatedFrom;
@@ -156,6 +159,8 @@ pub mod pallet {
 		type LaneMessageVerifier: LaneMessageVerifier<Self::OutboundPayload>;
 		/// Delivery confirmation payments.
 		type DeliveryConfirmationPayments: DeliveryConfirmationPayments<Self::AccountId>;
+		/// Delivery confirmation callback.
+		type OnMessagesDelivered: OnMessagesDelivered;
 
 		// Types that are used by inbound_lane (on target chain).
 
@@ -281,6 +286,9 @@ pub mod pallet {
 				Error::<T, I>::TooManyMessagesInTheProof
 			);
 
+			// if message dispatcher is currently inactive, we won't accept any messages
+			ensure!(T::MessageDispatch::is_active(), Error::<T, I>::MessageDispatchInactive);
+
 			// why do we need to know the weight of this (`receive_messages_proof`) call? Because
 			// we may want to return some funds for not-dispatching (or partially dispatching) some
 			// messages to the call origin (relayer). And this is done by returning actual weight
@@ -487,6 +495,12 @@ pub mod pallet {
 				lane_id,
 			);
 
+			// notify others about messages delivery
+			T::OnMessagesDelivered::on_messages_delivered(
+				lane_id,
+				lane.data().queued_messages().saturating_len(),
+			);
+
 			// because of lags, the inbound lane state (`lane_data`) may have entries for
 			// already rewarded relayers and messages (if all entries are duplicated, then
 			// this transaction must be filtered out by our signed extension)
@@ -518,6 +532,8 @@ pub mod pallet {
 		NotOperatingNormally,
 		/// The outbound lane is inactive.
 		InactiveOutboundLane,
+		/// The inbound message dispatcher is inactive.
+		MessageDispatchInactive,
 		/// Message has been treated as invalid by chain verifier.
 		MessageRejectedByChainVerifier(VerificationError),
 		/// Message has been treated as invalid by lane verifier.
@@ -580,6 +596,25 @@ pub mod pallet {
 		MaxValues = MaybeOutboundLanesCount<T, I>,
 	>;
 
+	/// Map of lane id => is congested signal sent. It is managed by the
+	/// `bridge_runtime_common::LocalXcmQueueManager`.
+	///
+	/// **bridges-v1**: this map is a temporary hack and will be dropped in the `v2`. We can emulate
+	/// a storage map using `sp_io::unhashed` storage functions, but then benchmarks are not
+	/// accounting its `proof_size`, so it is missing from the final weights. So we need to make it
+	/// a map inside some pallet. We could use a simply value instead of map here, because
+	/// in `v1` we'll only have a single lane. But in the case of adding another lane before `v2`,
+	/// it'll be easier to deal with the isolated storage map instead.
+	#[pallet::storage]
+	pub type OutboundLanesCongestedSignals<T: Config<I>, I: 'static = ()> = StorageMap<
+		Hasher = Blake2_128Concat,
+		Key = LaneId,
+		Value = bool,
+		QueryKind = ValueQuery,
+		OnEmpty = GetDefault,
+		MaxValues = MaybeOutboundLanesCount<T, I>,
+	>;
+
 	/// All queued outbound messages.
 	#[pallet::storage]
 	pub type OutboundMessages<T: Config<I>, I: 'static = ()> =
@@ -627,6 +662,11 @@ pub mod pallet {
 			}
 		}
 
+		/// Return outbound lane data.
+		pub fn outbound_lane_data(lane: LaneId) -> OutboundLaneData {
+			OutboundLanes::<T, I>::get(lane)
+		}
+
 		/// Return inbound lane data.
 		pub fn inbound_lane_data(lane: LaneId) -> InboundLaneData<T::InboundRelayer> {
 			InboundLanes::<T, I>::get(lane).0
@@ -703,6 +743,9 @@ fn send_message<T: Config<I>, I: 'static>(
 		.send_message(encoded_payload)
 		.map_err(Error::<T, I>::MessageRejectedByPallet)?;
 
+	// return number of messages in the queue to let sender know about its state
+	let enqueued_messages = lane.data().queued_messages().saturating_len();
+
 	log::trace!(
 		target: LOG_TARGET,
 		"Accepted message {} to lane {:?}. Message size: {:?}",
@@ -713,7 +756,7 @@ fn send_message<T: Config<I>, I: 'static>(
 
 	Pallet::<T, I>::deposit_event(Event::MessageAccepted { lane_id, nonce });
 
-	Ok(SendMessageArtifacts { nonce })
+	Ok(SendMessageArtifacts { nonce, enqueued_messages })
 }
 
 /// Ensure that the pallet is in normal operational mode.
@@ -881,8 +924,9 @@ mod tests {
 		mock::{
 			inbound_unrewarded_relayers_state, message, message_payload, run_test,
 			unrewarded_relayer, AccountId, DbWeight, RuntimeEvent as TestEvent, RuntimeOrigin,
-			TestDeliveryConfirmationPayments, TestDeliveryPayments, TestMessagesDeliveryProof,
-			TestMessagesProof, TestRelayer, TestRuntime, TestWeightInfo, MAX_OUTBOUND_PAYLOAD_SIZE,
+			TestDeliveryConfirmationPayments, TestDeliveryPayments, TestMessageDispatch,
+			TestMessagesDeliveryProof, TestMessagesProof, TestOnMessagesDelivered, TestRelayer,
+			TestRuntime, TestWeightInfo, MAX_OUTBOUND_PAYLOAD_SIZE,
 			PAYLOAD_REJECTED_BY_TARGET_CHAIN, REGULAR_PAYLOAD, TEST_LANE_ID, TEST_LANE_ID_2,
 			TEST_LANE_ID_3, TEST_RELAYER_A, TEST_RELAYER_B,
 		},
@@ -908,10 +952,12 @@ mod tests {
 	fn send_regular_message() {
 		get_ready_for_events();
 
-		let message_nonce =
-			outbound_lane::<TestRuntime, ()>(TEST_LANE_ID).data().latest_generated_nonce + 1;
-		send_message::<TestRuntime, ()>(TEST_LANE_ID, REGULAR_PAYLOAD)
+		let outbound_lane = outbound_lane::<TestRuntime, ()>(TEST_LANE_ID);
+		let message_nonce = outbound_lane.data().latest_generated_nonce + 1;
+		let prev_enqueud_messages = outbound_lane.data().queued_messages().saturating_len();
+		let artifacts = send_message::<TestRuntime, ()>(TEST_LANE_ID, REGULAR_PAYLOAD)
 			.expect("send_message has failed");
+		assert_eq!(artifacts.enqueued_messages, prev_enqueud_messages + 1);
 
 		// check event with assigned nonce
 		assert_eq!(
@@ -1201,6 +1247,23 @@ mod tests {
 		});
 	}
 
+	#[test]
+	fn receive_messages_fails_if_dispatcher_is_inactive() {
+		run_test(|| {
+			TestMessageDispatch::deactivate();
+			assert_noop!(
+				Pallet::<TestRuntime>::receive_messages_proof(
+					RuntimeOrigin::signed(1),
+					TEST_RELAYER_A,
+					Ok(vec![message(1, REGULAR_PAYLOAD)]).into(),
+					1,
+					REGULAR_PAYLOAD.declared_weight,
+				),
+				Error::<TestRuntime, ()>::MessageDispatchInactive,
+			);
+		});
+	}
+
 	#[test]
 	fn receive_messages_proof_does_not_accept_message_if_dispatch_weight_is_not_enough() {
 		run_test(|| {
@@ -1304,6 +1367,7 @@ mod tests {
 			);
 			assert!(TestDeliveryConfirmationPayments::is_reward_paid(TEST_RELAYER_A, 1));
 			assert!(!TestDeliveryConfirmationPayments::is_reward_paid(TEST_RELAYER_B, 1));
+			assert_eq!(TestOnMessagesDelivered::call_arguments(), Some((TEST_LANE_ID, 1)));
 
 			// this reports delivery of both message 1 and message 2 => reward is paid only to
 			// TEST_RELAYER_B
@@ -1346,6 +1410,7 @@ mod tests {
 			);
 			assert!(!TestDeliveryConfirmationPayments::is_reward_paid(TEST_RELAYER_A, 1));
 			assert!(TestDeliveryConfirmationPayments::is_reward_paid(TEST_RELAYER_B, 1));
+			assert_eq!(TestOnMessagesDelivered::call_arguments(), Some((TEST_LANE_ID, 0)));
 		});
 	}
 

cumulus/bridges/modules/messages/src/mock.rs

@@ -21,7 +21,9 @@ use crate::Config;
 
 use bp_messages::{
 	calc_relayers_rewards,
-	source_chain::{DeliveryConfirmationPayments, LaneMessageVerifier, TargetHeaderChain},
+	source_chain::{
+		DeliveryConfirmationPayments, LaneMessageVerifier, OnMessagesDelivered, TargetHeaderChain,
+	},
 	target_chain::{
 		DeliveryPayments, DispatchMessage, DispatchMessageData, MessageDispatch,
 		ProvedLaneMessages, ProvedMessages, SourceHeaderChain,
@@ -161,6 +163,7 @@ impl Config for TestRuntime {
 	type TargetHeaderChain = TestTargetHeaderChain;
 	type LaneMessageVerifier = TestLaneMessageVerifier;
 	type DeliveryConfirmationPayments = TestDeliveryConfirmationPayments;
+	type OnMessagesDelivered = TestOnMessagesDelivered;
 
 	type SourceHeaderChain = TestSourceHeaderChain;
 	type MessageDispatch = TestMessageDispatch;
@@ -402,14 +405,26 @@ impl SourceHeaderChain for TestSourceHeaderChain {
 	}
 }
 
-/// Source header chain that is used in tests.
+/// Test message dispatcher.
 #[derive(Debug)]
 pub struct TestMessageDispatch;
 
+impl TestMessageDispatch {
+	pub fn deactivate() {
+		frame_support::storage::unhashed::put(b"TestMessageDispatch.IsCongested", &true)
+	}
+}
+
 impl MessageDispatch for TestMessageDispatch {
 	type DispatchPayload = TestPayload;
 	type DispatchLevelResult = TestDispatchLevelResult;
 
+	fn is_active() -> bool {
+		!frame_support::storage::unhashed::get_or_default::<bool>(
+			b"TestMessageDispatch.IsCongested",
+		)
+	}
+
 	fn dispatch_weight(message: &mut DispatchMessage<TestPayload>) -> Weight {
 		match message.data.payload.as_ref() {
 			Ok(payload) => payload.declared_weight,
@@ -427,6 +442,24 @@ impl MessageDispatch for TestMessageDispatch {
 	}
 }
 
+/// Test callback, called during message delivery confirmation transaction.
+pub struct TestOnMessagesDelivered;
+
+impl TestOnMessagesDelivered {
+	pub fn call_arguments() -> Option<(LaneId, MessageNonce)> {
+		frame_support::storage::unhashed::get(b"TestOnMessagesDelivered.OnMessagesDelivered")
+	}
+}
+
+impl OnMessagesDelivered for TestOnMessagesDelivered {
+	fn on_messages_delivered(lane: LaneId, enqueued_messages: MessageNonce) {
+		frame_support::storage::unhashed::put(
+			b"TestOnMessagesDelivered.OnMessagesDelivered",
+			&(lane, enqueued_messages),
+		);
+	}
+}
+
 /// Return test lane message with given nonce and payload.
 pub fn message(nonce: MessageNonce, payload: TestPayload) -> Message {
 	Message { key: MessageKey { lane_id: TEST_LANE_ID, nonce }, payload: payload.encode() }

cumulus/bridges/modules/parachains/src/lib.rs

@@ -697,7 +697,7 @@ pub(crate) mod tests {
 	use bp_test_utils::prepare_parachain_heads_proof;
 	use codec::Encode;
 
-	use bp_header_chain::{justification::GrandpaJustification, HeaderGrandpaInfo};
+	use bp_header_chain::{justification::GrandpaJustification, StoredHeaderGrandpaInfo};
 	use bp_parachains::{
 		BestParaHeadHash, BridgeParachainCall, ImportedParaHeadsKeyProvider, ParasInfoKeyProvider,
 	};
@@ -1036,9 +1036,9 @@ pub(crate) mod tests {
 							pallet_bridge_grandpa::Event::UpdatedBestFinalizedHeader {
 								number: 1,
 								hash: relay_1_hash,
-								grandpa_info: HeaderGrandpaInfo {
-									justification,
-									authority_set: None,
+								grandpa_info: StoredHeaderGrandpaInfo {
+									finality_proof: justification,
+									new_verification_context: None,
 								},
 							}
 						),
@@ -1177,9 +1177,9 @@ pub(crate) mod tests {
 							pallet_bridge_grandpa::Event::UpdatedBestFinalizedHeader {
 								number: 1,
 								hash: relay_1_hash,
-								grandpa_info: HeaderGrandpaInfo {
-									justification,
-									authority_set: None,
+								grandpa_info: StoredHeaderGrandpaInfo {
+									finality_proof: justification,
+									new_verification_context: None,
 								}
 							}
 						),
@@ -1230,9 +1230,9 @@ pub(crate) mod tests {
 							pallet_bridge_grandpa::Event::UpdatedBestFinalizedHeader {
 								number: 1,
 								hash: relay_1_hash,
-								grandpa_info: HeaderGrandpaInfo {
-									justification: justification.clone(),
-									authority_set: None,
+								grandpa_info: StoredHeaderGrandpaInfo {
+									finality_proof: justification.clone(),
+									new_verification_context: None,
 								}
 							}
 						),
@@ -1271,9 +1271,9 @@ pub(crate) mod tests {
 							pallet_bridge_grandpa::Event::UpdatedBestFinalizedHeader {
 								number: 1,
 								hash: relay_1_hash,
-								grandpa_info: HeaderGrandpaInfo {
-									justification,
-									authority_set: None,
+								grandpa_info: StoredHeaderGrandpaInfo {
+									finality_proof: justification,
+									new_verification_context: None,
 								}
 							}
 						),

cumulus/bridges/modules/xcm-bridge-hub-router/Cargo.toml

@@ -0,0 +1,59 @@
+[package]
+name = "pallet-xcm-bridge-hub-router"
+description = "Bridge hub interface for sibling/parent chains with dynamic fees support."
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2021"
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.1.5", default-features = false }
+log = { version = "0.4.19", default-features = false }
+scale-info = { version = "2.8.0", default-features = false, features = ["bit-vec", "derive", "serde"] }
+
+# Bridge dependencies
+
+bp-xcm-bridge-hub-router = { path = "../../primitives/xcm-bridge-hub-router", default-features = false }
+
+# Substrate Dependencies
+
+frame-benchmarking = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false, optional = true }
+frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+frame-system = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+
+# Polkadot Dependencies
+
+xcm = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false }
+xcm-builder = { git = "https://github.com/paritytech/polkadot", branch = "master", default-features = false }
+
+[dev-dependencies]
+sp-io = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sp-std = { git = "https://github.com/paritytech/substrate", branch = "master" }
+
+[features]
+default = ["std"]
+std = [
+	"bp-xcm-bridge-hub-router/std",
+	"codec/std",
+	"frame-benchmarking/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"scale-info/std",
+	"sp-core/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm/std",
+	"xcm-builder/std",
+]
+runtime-benchmarks = [
+	"frame-benchmarking/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+]

cumulus/bridges/modules/xcm-bridge-hub-router/src/benchmarking.rs

@@ -0,0 +1,96 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! XCM bridge hub router pallet benchmarks.
+
+#![cfg(feature = "runtime-benchmarks")]
+
+use crate::{Bridge, Call};
+
+use bp_xcm_bridge_hub_router::{BridgeState, MINIMAL_DELIVERY_FEE_FACTOR};
+use frame_benchmarking::benchmarks_instance_pallet;
+use frame_support::{
+	dispatch::UnfilteredDispatchable,
+	traits::{EnsureOrigin, Get, Hooks},
+};
+use sp_runtime::traits::Zero;
+use xcm::prelude::*;
+
+/// Pallet we're benchmarking here.
+pub struct Pallet<T: Config<I>, I: 'static = ()>(crate::Pallet<T, I>);
+
+/// Trait that must be implemented by runtime to be able to benchmark pallet properly.
+pub trait Config<I: 'static>: crate::Config<I> {
+	/// Fill up queue so it becomes congested.
+	fn make_congested();
+
+	/// Returns destination which is valid for this router instance.
+	/// (Needs to pass `T::Bridges`)
+	/// Make sure that `SendXcm` will pass.
+	fn ensure_bridged_target_destination() -> MultiLocation {
+		MultiLocation::new(
+			Self::UniversalLocation::get().len() as u8,
+			X1(GlobalConsensus(Self::BridgedNetworkId::get().unwrap())),
+		)
+	}
+}
+
+benchmarks_instance_pallet! {
+	on_initialize_when_non_congested {
+		Bridge::<T, I>::put(BridgeState {
+			is_congested: false,
+			delivery_fee_factor: MINIMAL_DELIVERY_FEE_FACTOR + MINIMAL_DELIVERY_FEE_FACTOR,
+		});
+	}: {
+		crate::Pallet::<T, I>::on_initialize(Zero::zero())
+	}
+
+	on_initialize_when_congested {
+		Bridge::<T, I>::put(BridgeState {
+			is_congested: false,
+			delivery_fee_factor: MINIMAL_DELIVERY_FEE_FACTOR + MINIMAL_DELIVERY_FEE_FACTOR,
+		});
+		T::make_congested();
+	}: {
+		crate::Pallet::<T, I>::on_initialize(Zero::zero())
+	}
+
+	report_bridge_status {
+		Bridge::<T, I>::put(BridgeState::default());
+
+		let origin: T::RuntimeOrigin = T::BridgeHubOrigin::try_successful_origin().expect("expected valid BridgeHubOrigin");
+		let bridge_id = Default::default();
+		let is_congested = true;
+
+		let call = Call::<T, I>::report_bridge_status { bridge_id, is_congested };
+	}: { call.dispatch_bypass_filter(origin)? }
+	verify {
+		assert!(Bridge::<T, I>::get().is_congested);
+	}
+
+	send_message {
+		// make local queue congested, because it means additional db write
+		T::make_congested();
+
+		let dest = T::ensure_bridged_target_destination();
+		let xcm = sp_std::vec![].into();
+	}: {
+		send_xcm::<crate::Pallet<T, I>>(dest, xcm).expect("message is sent")
+	}
+	verify {
+		assert!(Bridge::<T, I>::get().delivery_fee_factor > MINIMAL_DELIVERY_FEE_FACTOR);
+	}
+}

cumulus/bridges/modules/xcm-bridge-hub-router/src/lib.rs

@@ -0,0 +1,557 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Pallet that may be used instead of `SovereignPaidRemoteExporter` in the XCM router
+//! configuration. The main thing that the pallet offers is the dynamic message fee,
+//! that is computed based on the bridge queues state. It starts exponentially increasing
+//! if the queue between this chain and the sibling/child bridge hub is congested.
+//!
+//! All other bridge hub queues offer some backpressure mechanisms. So if at least one
+//! of all queues is congested, it will eventually lead to the growth of the queue at
+//! this chain.
+//!
+//! **A note on terminology**: when we mention the bridge hub here, we mean the chain that
+//! has the messages pallet deployed (`pallet-bridge-grandpa`, `pallet-bridge-messages`,
+//! `pallet-xcm-bridge-hub`, ...). It may be the system bridge hub parachain or any other
+//! chain.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use bp_xcm_bridge_hub_router::{
+	BridgeState, XcmChannelStatusProvider, MINIMAL_DELIVERY_FEE_FACTOR,
+};
+use codec::Encode;
+use frame_support::traits::Get;
+use sp_core::H256;
+use sp_runtime::{FixedPointNumber, FixedU128, Saturating};
+use xcm::prelude::*;
+use xcm_builder::{ExporterFor, SovereignPaidRemoteExporter};
+
+pub use pallet::*;
+pub use weights::WeightInfo;
+
+pub mod benchmarking;
+pub mod weights;
+
+mod mock;
+
+/// The factor that is used to increase current message fee factor when bridge experiencing
+/// some lags.
+const EXPONENTIAL_FEE_BASE: FixedU128 = FixedU128::from_rational(105, 100); // 1.05
+/// The factor that is used to increase current message fee factor for every sent kilobyte.
+const MESSAGE_SIZE_FEE_BASE: FixedU128 = FixedU128::from_rational(1, 1000); // 0.001
+
+/// Maximal size of the XCM message that may be sent over bridge.
+///
+/// This should be less than the maximal size, allowed by the messages pallet, because
+/// the message itself is wrapped in other structs and is double encoded.
+pub const HARD_MESSAGE_SIZE_LIMIT: u32 = 32 * 1024;
+
+/// The target that will be used when publishing logs related to this pallet.
+///
+/// This doesn't match the pattern used by other bridge pallets (`runtime::bridge-*`). But this
+/// pallet has significant differences with those pallets. The main one is that is intended to
+/// be deployed at sending chains. Other bridge pallets are likely to be deployed at the separate
+/// bridge hub parachain.
+pub const LOG_TARGET: &str = "xcm::bridge-hub-router";
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::config]
+	pub trait Config<I: 'static = ()>: frame_system::Config {
+		/// Benchmarks results from runtime we're plugged into.
+		type WeightInfo: WeightInfo;
+
+		/// Universal location of this runtime.
+		type UniversalLocation: Get<InteriorMultiLocation>;
+		/// The bridged network that this config is for if specified.
+		/// Also used for filtering `Bridges` by `BridgedNetworkId`.
+		/// If not specified, allows all networks pass through.
+		type BridgedNetworkId: Get<Option<NetworkId>>;
+		/// Configuration for supported **bridged networks/locations** with **bridge location** and
+		/// **possible fee**. Allows to externalize better control over allowed **bridged
+		/// networks/locations**.
+		type Bridges: ExporterFor;
+
+		/// Origin of the sibling bridge hub that is allowed to report bridge status.
+		type BridgeHubOrigin: EnsureOrigin<Self::RuntimeOrigin>;
+		/// Actual message sender (`HRMP` or `DMP`) to the sibling bridge hub location.
+		type ToBridgeHubSender: SendXcm;
+		/// Underlying channel with the sibling bridge hub. It must match the channel, used
+		/// by the `Self::ToBridgeHubSender`.
+		type WithBridgeHubChannel: XcmChannelStatusProvider;
+
+		/// Additional fee that is paid for every byte of the outbound message.
+		type ByteFee: Get<u128>;
+		/// Asset that is used to paid bridge fee.
+		type FeeAsset: Get<AssetId>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T, I = ()>(PhantomData<(T, I)>);
+
+	#[pallet::hooks]
+	impl<T: Config<I>, I: 'static> Hooks<BlockNumberFor<T>> for Pallet<T, I> {
+		fn on_initialize(_n: BlockNumberFor<T>) -> Weight {
+			// TODO: make sure that `WithBridgeHubChannel::is_congested` returns true if either
+			// of XCM channels (outbound/inbound) is suspended. Because if outbound is suspended
+			// that is definitely congestion. If inbound is suspended, then we are not able to
+			// receive the "report_bridge_status" signal (that maybe sent by the bridge hub).
+
+			// if the channel with sibling/child bridge hub is suspended, we don't change
+			// anything
+			if T::WithBridgeHubChannel::is_congested() {
+				return T::WeightInfo::on_initialize_when_congested()
+			}
+
+			// if bridge has reported congestion, we don't change anything
+			let mut bridge = Self::bridge();
+			if bridge.is_congested {
+				return T::WeightInfo::on_initialize_when_congested()
+			}
+
+			// if fee factor is already minimal, we don't change anything
+			if bridge.delivery_fee_factor == MINIMAL_DELIVERY_FEE_FACTOR {
+				return T::WeightInfo::on_initialize_when_congested()
+			}
+
+			let previous_factor = bridge.delivery_fee_factor;
+			bridge.delivery_fee_factor =
+				MINIMAL_DELIVERY_FEE_FACTOR.max(bridge.delivery_fee_factor / EXPONENTIAL_FEE_BASE);
+			log::info!(
+				target: LOG_TARGET,
+				"Bridge queue is uncongested. Decreased fee factor from {} to {}",
+				previous_factor,
+				bridge.delivery_fee_factor,
+			);
+
+			Bridge::<T, I>::put(bridge);
+			T::WeightInfo::on_initialize_when_non_congested()
+		}
+	}
+
+	#[pallet::call]
+	impl<T: Config<I>, I: 'static> Pallet<T, I> {
+		/// Notification about congested bridge queue.
+		#[pallet::call_index(0)]
+		#[pallet::weight(T::WeightInfo::report_bridge_status())]
+		pub fn report_bridge_status(
+			origin: OriginFor<T>,
+			// this argument is not currently used, but to ease future migration, we'll keep it
+			// here
+			bridge_id: H256,
+			is_congested: bool,
+		) -> DispatchResult {
+			let _ = T::BridgeHubOrigin::ensure_origin(origin)?;
+
+			log::info!(
+				target: LOG_TARGET,
+				"Received bridge status from {:?}: congested = {}",
+				bridge_id,
+				is_congested,
+			);
+
+			Bridge::<T, I>::mutate(|bridge| {
+				bridge.is_congested = is_congested;
+			});
+			Ok(())
+		}
+	}
+
+	/// Bridge that we are using.
+	///
+	/// **bridges-v1** assumptions: all outbound messages through this router are using single lane
+	/// and to single remote consensus. If there is some other remote consensus that uses the same
+	/// bridge hub, the separate pallet instance shall be used, In `v2` we'll have all required
+	/// primitives (lane-id aka bridge-id, derived from XCM locations) to support multiple  bridges
+	/// by the same pallet instance.
+	#[pallet::storage]
+	#[pallet::getter(fn bridge)]
+	pub type Bridge<T: Config<I>, I: 'static = ()> = StorageValue<_, BridgeState, ValueQuery>;
+
+	impl<T: Config<I>, I: 'static> Pallet<T, I> {
+		/// Called when new message is sent (queued to local outbound XCM queue) over the bridge.
+		pub(crate) fn on_message_sent_to_bridge(message_size: u32) {
+			let _ = Bridge::<T, I>::try_mutate(|bridge| {
+				let is_channel_with_bridge_hub_congested = T::WithBridgeHubChannel::is_congested();
+				let is_bridge_congested = bridge.is_congested;
+
+				// if outbound queue is not congested AND bridge has not reported congestion, do
+				// nothing
+				if !is_channel_with_bridge_hub_congested && !is_bridge_congested {
+					return Err(())
+				}
+
+				// ok - we need to increase the fee factor, let's do that
+				let message_size_factor = FixedU128::from_u32(message_size.saturating_div(1024))
+					.saturating_mul(MESSAGE_SIZE_FEE_BASE);
+				let total_factor = EXPONENTIAL_FEE_BASE.saturating_add(message_size_factor);
+				let previous_factor = bridge.delivery_fee_factor;
+				bridge.delivery_fee_factor =
+					bridge.delivery_fee_factor.saturating_mul(total_factor);
+
+				log::info!(
+					target: LOG_TARGET,
+					"Bridge channel is congested. Increased fee factor from {} to {}",
+					previous_factor,
+					bridge.delivery_fee_factor,
+				);
+
+				Ok(())
+			});
+		}
+	}
+}
+
+/// We'll be using `SovereignPaidRemoteExporter` to send remote messages over the sibling/child
+/// bridge hub.
+type ViaBridgeHubExporter<T, I> = SovereignPaidRemoteExporter<
+	Pallet<T, I>,
+	<T as Config<I>>::ToBridgeHubSender,
+	<T as Config<I>>::UniversalLocation,
+>;
+
+// This pallet acts as the `ExporterFor` for the `SovereignPaidRemoteExporter` to compute
+// message fee using fee factor.
+impl<T: Config<I>, I: 'static> ExporterFor for Pallet<T, I> {
+	fn exporter_for(
+		network: &NetworkId,
+		remote_location: &InteriorMultiLocation,
+		message: &Xcm<()>,
+	) -> Option<(MultiLocation, Option<MultiAsset>)> {
+		// ensure that the message is sent to the expected bridged network (if specified).
+		if let Some(bridged_network) = T::BridgedNetworkId::get() {
+			if *network != bridged_network {
+				log::trace!(
+					target: LOG_TARGET,
+					"Router with bridged_network_id {:?} does not support bridging to network {:?}!",
+					bridged_network,
+					network,
+				);
+				return None
+			}
+		}
+
+		// ensure that the message is sent to the expected bridged network and location.
+		let Some((bridge_hub_location, maybe_payment)) =
+			T::Bridges::exporter_for(network, remote_location, message)
+		else {
+			log::trace!(
+				target: LOG_TARGET,
+				"Router with bridged_network_id {:?} does not support bridging to network {:?} and remote_location {:?}!",
+				T::BridgedNetworkId::get(),
+				network,
+				remote_location,
+			);
+			return None
+		};
+
+		// take `base_fee` from `T::Brides`, but it has to be the same `T::FeeAsset`
+		let base_fee = match maybe_payment {
+			Some(payment) => match payment {
+				MultiAsset { fun: Fungible(amount), id } if id.eq(&T::FeeAsset::get()) => amount,
+				invalid_asset => {
+					log::error!(
+						target: LOG_TARGET,
+						"Router with bridged_network_id {:?} is configured for `T::FeeAsset` {:?} which is not \
+						compatible with {:?} for bridge_hub_location: {:?} for bridging to {:?}/{:?}!",
+						T::BridgedNetworkId::get(),
+						T::FeeAsset::get(),
+						invalid_asset,
+						bridge_hub_location,
+						network,
+						remote_location,
+					);
+					return None
+				},
+			},
+			None => 0,
+		};
+
+		// compute fee amount. Keep in mind that this is only the bridge fee. The fee for sending
+		// message from this chain to child/sibling bridge hub is determined by the
+		// `Config::ToBridgeHubSender`
+		let message_size = message.encoded_size();
+		let message_fee = (message_size as u128).saturating_mul(T::ByteFee::get());
+		let fee_sum = base_fee.saturating_add(message_fee);
+		let fee_factor = Self::bridge().delivery_fee_factor;
+		let fee = fee_factor.saturating_mul_int(fee_sum);
+
+		let fee = if fee > 0 { Some((T::FeeAsset::get(), fee).into()) } else { None };
+
+		log::info!(
+			target: LOG_TARGET,
+			"Going to send message to {:?} ({} bytes) over bridge. Computed bridge fee {:?} using fee factor {}",
+			(network, remote_location),
+			message_size,
+			fee,
+			fee_factor
+		);
+
+		Some((bridge_hub_location, fee))
+	}
+}
+
+// This pallet acts as the `SendXcm` to the sibling/child bridge hub instead of regular
+// XCMP/DMP transport. This allows injecting dynamic message fees into XCM programs that
+// are going to the bridged network.
+impl<T: Config<I>, I: 'static> SendXcm for Pallet<T, I> {
+	type Ticket = (u32, <T::ToBridgeHubSender as SendXcm>::Ticket);
+
+	fn validate(
+		dest: &mut Option<MultiLocation>,
+		xcm: &mut Option<Xcm<()>>,
+	) -> SendResult<Self::Ticket> {
+		// we won't have an access to `dest` and `xcm` in the `delvier` method, so precompute
+		// everything required here
+		let message_size = xcm
+			.as_ref()
+			.map(|xcm| xcm.encoded_size() as _)
+			.ok_or(SendError::MissingArgument)?;
+
+		// bridge doesn't support oversized/overweight messages now. So it is better to drop such
+		// messages here than at the bridge hub. Let's check the message size.
+		if message_size > HARD_MESSAGE_SIZE_LIMIT {
+			return Err(SendError::ExceedsMaxMessageSize)
+		}
+
+		// just use exporter to validate destination and insert instructions to pay message fee
+		// at the sibling/child bridge hub
+		//
+		// the cost will include both cost of: (1) to-sibling bridg hub delivery (returned by
+		// the `Config::ToBridgeHubSender`) and (2) to-bridged bridge hub delivery (returned by
+		// `Self::exporter_for`)
+		ViaBridgeHubExporter::<T, I>::validate(dest, xcm)
+			.map(|(ticket, cost)| ((message_size, ticket), cost))
+	}
+
+	fn deliver(ticket: Self::Ticket) -> Result<XcmHash, SendError> {
+		// use router to enqueue message to the sibling/child bridge hub. This also should handle
+		// payment for passing through this queue.
+		let (message_size, ticket) = ticket;
+		let xcm_hash = ViaBridgeHubExporter::<T, I>::deliver(ticket)?;
+
+		// increase delivery fee factor if required
+		Self::on_message_sent_to_bridge(message_size);
+
+		Ok(xcm_hash)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use mock::*;
+
+	use frame_support::traits::Hooks;
+	use sp_runtime::traits::One;
+
+	fn congested_bridge(delivery_fee_factor: FixedU128) -> BridgeState {
+		BridgeState { is_congested: true, delivery_fee_factor }
+	}
+
+	fn uncongested_bridge(delivery_fee_factor: FixedU128) -> BridgeState {
+		BridgeState { is_congested: false, delivery_fee_factor }
+	}
+
+	#[test]
+	fn initial_fee_factor_is_one() {
+		run_test(|| {
+			assert_eq!(
+				Bridge::<TestRuntime, ()>::get(),
+				uncongested_bridge(MINIMAL_DELIVERY_FEE_FACTOR),
+			);
+		})
+	}
+
+	#[test]
+	fn fee_factor_is_not_decreased_from_on_initialize_when_xcm_channel_is_congested() {
+		run_test(|| {
+			Bridge::<TestRuntime, ()>::put(uncongested_bridge(FixedU128::from_rational(125, 100)));
+			TestWithBridgeHubChannel::make_congested();
+
+			// it should not decrease, because xcm channel is congested
+			let old_bridge = XcmBridgeHubRouter::bridge();
+			XcmBridgeHubRouter::on_initialize(One::one());
+			assert_eq!(XcmBridgeHubRouter::bridge(), old_bridge);
+		})
+	}
+
+	#[test]
+	fn fee_factor_is_not_decreased_from_on_initialize_when_bridge_has_reported_congestion() {
+		run_test(|| {
+			Bridge::<TestRuntime, ()>::put(congested_bridge(FixedU128::from_rational(125, 100)));
+
+			// it should not decrease, because bridge congested
+			let old_bridge = XcmBridgeHubRouter::bridge();
+			XcmBridgeHubRouter::on_initialize(One::one());
+			assert_eq!(XcmBridgeHubRouter::bridge(), old_bridge);
+		})
+	}
+
+	#[test]
+	fn fee_factor_is_decreased_from_on_initialize_when_xcm_channel_is_uncongested() {
+		run_test(|| {
+			Bridge::<TestRuntime, ()>::put(uncongested_bridge(FixedU128::from_rational(125, 100)));
+
+			// it shold eventually decreased to one
+			while XcmBridgeHubRouter::bridge().delivery_fee_factor > MINIMAL_DELIVERY_FEE_FACTOR {
+				XcmBridgeHubRouter::on_initialize(One::one());
+			}
+
+			// verify that it doesn't decreases anymore
+			XcmBridgeHubRouter::on_initialize(One::one());
+			assert_eq!(
+				XcmBridgeHubRouter::bridge(),
+				uncongested_bridge(MINIMAL_DELIVERY_FEE_FACTOR)
+			);
+		})
+	}
+
+	#[test]
+	fn not_applicable_if_destination_is_within_other_network() {
+		run_test(|| {
+			assert_eq!(
+				send_xcm::<XcmBridgeHubRouter>(
+					MultiLocation::new(2, X2(GlobalConsensus(Rococo), Parachain(1000))),
+					vec![].into(),
+				),
+				Err(SendError::NotApplicable),
+			);
+		});
+	}
+
+	#[test]
+	fn exceeds_max_message_size_if_size_is_above_hard_limit() {
+		run_test(|| {
+			assert_eq!(
+				send_xcm::<XcmBridgeHubRouter>(
+					MultiLocation::new(2, X2(GlobalConsensus(Rococo), Parachain(1000))),
+					vec![ClearOrigin; HARD_MESSAGE_SIZE_LIMIT as usize].into(),
+				),
+				Err(SendError::ExceedsMaxMessageSize),
+			);
+		});
+	}
+
+	#[test]
+	fn returns_proper_delivery_price() {
+		run_test(|| {
+			let dest = MultiLocation::new(2, X1(GlobalConsensus(BridgedNetworkId::get())));
+			let xcm: Xcm<()> = vec![ClearOrigin].into();
+			let msg_size = xcm.encoded_size();
+
+			// initially the base fee is used: `BASE_FEE + BYTE_FEE * msg_size + HRMP_FEE`
+			let expected_fee = BASE_FEE + BYTE_FEE * (msg_size as u128) + HRMP_FEE;
+			assert_eq!(
+				XcmBridgeHubRouter::validate(&mut Some(dest), &mut Some(xcm.clone()))
+					.unwrap()
+					.1
+					.get(0),
+				Some(&(BridgeFeeAsset::get(), expected_fee).into()),
+			);
+
+			// but when factor is larger than one, it increases the fee, so it becomes:
+			// `(BASE_FEE + BYTE_FEE * msg_size) * F + HRMP_FEE`
+			let factor = FixedU128::from_rational(125, 100);
+			Bridge::<TestRuntime, ()>::put(uncongested_bridge(factor));
+			let expected_fee =
+				(FixedU128::saturating_from_integer(BASE_FEE + BYTE_FEE * (msg_size as u128)) *
+					factor)
+					.into_inner() / FixedU128::DIV +
+					HRMP_FEE;
+			assert_eq!(
+				XcmBridgeHubRouter::validate(&mut Some(dest), &mut Some(xcm)).unwrap().1.get(0),
+				Some(&(BridgeFeeAsset::get(), expected_fee).into()),
+			);
+		});
+	}
+
+	#[test]
+	fn sent_message_doesnt_increase_factor_if_xcm_channel_is_uncongested() {
+		run_test(|| {
+			let old_bridge = XcmBridgeHubRouter::bridge();
+			assert_eq!(
+				send_xcm::<XcmBridgeHubRouter>(
+					MultiLocation::new(
+						2,
+						X2(GlobalConsensus(BridgedNetworkId::get()), Parachain(1000))
+					),
+					vec![ClearOrigin].into(),
+				)
+				.map(drop),
+				Ok(()),
+			);
+
+			assert!(TestToBridgeHubSender::is_message_sent());
+			assert_eq!(old_bridge, XcmBridgeHubRouter::bridge());
+		});
+	}
+
+	#[test]
+	fn sent_message_increases_factor_if_xcm_channel_is_congested() {
+		run_test(|| {
+			TestWithBridgeHubChannel::make_congested();
+
+			let old_bridge = XcmBridgeHubRouter::bridge();
+			assert_eq!(
+				send_xcm::<XcmBridgeHubRouter>(
+					MultiLocation::new(
+						2,
+						X2(GlobalConsensus(BridgedNetworkId::get()), Parachain(1000))
+					),
+					vec![ClearOrigin].into(),
+				)
+				.map(drop),
+				Ok(()),
+			);
+
+			assert!(TestToBridgeHubSender::is_message_sent());
+			assert!(
+				old_bridge.delivery_fee_factor < XcmBridgeHubRouter::bridge().delivery_fee_factor
+			);
+		});
+	}
+
+	#[test]
+	fn sent_message_increases_factor_if_bridge_has_reported_congestion() {
+		run_test(|| {
+			Bridge::<TestRuntime, ()>::put(congested_bridge(MINIMAL_DELIVERY_FEE_FACTOR));
+
+			let old_bridge = XcmBridgeHubRouter::bridge();
+			assert_eq!(
+				send_xcm::<XcmBridgeHubRouter>(
+					MultiLocation::new(
+						2,
+						X2(GlobalConsensus(BridgedNetworkId::get()), Parachain(1000))
+					),
+					vec![ClearOrigin].into(),
+				)
+				.map(drop),
+				Ok(()),
+			);
+
+			assert!(TestToBridgeHubSender::is_message_sent());
+			assert!(
+				old_bridge.delivery_fee_factor < XcmBridgeHubRouter::bridge().delivery_fee_factor
+			);
+		});
+	}
+}

cumulus/bridges/modules/xcm-bridge-hub-router/src/mock.rs

@@ -0,0 +1,148 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+#![cfg(test)]
+
+use crate as pallet_xcm_bridge_hub_router;
+
+use bp_xcm_bridge_hub_router::XcmChannelStatusProvider;
+use frame_support::{construct_runtime, parameter_types};
+use frame_system::EnsureRoot;
+use sp_core::H256;
+use sp_runtime::{
+	traits::{BlakeTwo256, ConstU128, IdentityLookup},
+	BuildStorage,
+};
+use xcm::prelude::*;
+use xcm_builder::NetworkExportTable;
+
+pub type AccountId = u64;
+type Block = frame_system::mocking::MockBlock<TestRuntime>;
+
+/// HRMP fee.
+pub const HRMP_FEE: u128 = 500;
+/// Base bridge fee.
+pub const BASE_FEE: u128 = 1_000_000;
+/// Byte bridge fee.
+pub const BYTE_FEE: u128 = 1_000;
+
+construct_runtime! {
+	pub enum TestRuntime
+	{
+		System: frame_system::{Pallet, Call, Config<T>, Storage, Event<T>},
+		XcmBridgeHubRouter: pallet_xcm_bridge_hub_router::{Pallet, Storage},
+	}
+}
+
+parameter_types! {
+	pub ThisNetworkId: NetworkId = Polkadot;
+	pub BridgedNetworkId: NetworkId = Kusama;
+	pub UniversalLocation: InteriorMultiLocation = X2(GlobalConsensus(ThisNetworkId::get()), Parachain(1000));
+	pub SiblingBridgeHubLocation: MultiLocation = ParentThen(X1(Parachain(1002))).into();
+	pub BridgeFeeAsset: AssetId = MultiLocation::parent().into();
+	pub BridgeTable: Vec<(NetworkId, MultiLocation, Option<MultiAsset>)>
+		= vec![(BridgedNetworkId::get(), SiblingBridgeHubLocation::get(), Some((BridgeFeeAsset::get(), BASE_FEE).into()))];
+}
+
+impl frame_system::Config for TestRuntime {
+	type RuntimeOrigin = RuntimeOrigin;
+	type Nonce = u64;
+	type RuntimeCall = RuntimeCall;
+	type Block = Block;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type RuntimeEvent = RuntimeEvent;
+	type BlockHashCount = frame_support::traits::ConstU64<250>;
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type BaseCallFilter = frame_support::traits::Everything;
+	type SystemWeightInfo = ();
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+}
+
+impl pallet_xcm_bridge_hub_router::Config<()> for TestRuntime {
+	type WeightInfo = ();
+
+	type UniversalLocation = UniversalLocation;
+	type BridgedNetworkId = BridgedNetworkId;
+	type Bridges = NetworkExportTable<BridgeTable>;
+
+	type BridgeHubOrigin = EnsureRoot<AccountId>;
+	type ToBridgeHubSender = TestToBridgeHubSender;
+	type WithBridgeHubChannel = TestWithBridgeHubChannel;
+
+	type ByteFee = ConstU128<BYTE_FEE>;
+	type FeeAsset = BridgeFeeAsset;
+}
+
+pub struct TestToBridgeHubSender;
+
+impl TestToBridgeHubSender {
+	pub fn is_message_sent() -> bool {
+		frame_support::storage::unhashed::get_or_default(b"TestToBridgeHubSender.Sent")
+	}
+}
+
+impl SendXcm for TestToBridgeHubSender {
+	type Ticket = ();
+
+	fn validate(
+		_destination: &mut Option<MultiLocation>,
+		_message: &mut Option<Xcm<()>>,
+	) -> SendResult<Self::Ticket> {
+		Ok(((), (BridgeFeeAsset::get(), HRMP_FEE).into()))
+	}
+
+	fn deliver(_ticket: Self::Ticket) -> Result<XcmHash, SendError> {
+		frame_support::storage::unhashed::put(b"TestToBridgeHubSender.Sent", &true);
+		Ok([0u8; 32])
+	}
+}
+
+pub struct TestWithBridgeHubChannel;
+
+impl TestWithBridgeHubChannel {
+	pub fn make_congested() {
+		frame_support::storage::unhashed::put(b"TestWithBridgeHubChannel.Congested", &true);
+	}
+}
+
+impl XcmChannelStatusProvider for TestWithBridgeHubChannel {
+	fn is_congested() -> bool {
+		frame_support::storage::unhashed::get_or_default(b"TestWithBridgeHubChannel.Congested")
+	}
+}
+
+/// Return test externalities to use in tests.
+pub fn new_test_ext() -> sp_io::TestExternalities {
+	let t = frame_system::GenesisConfig::<TestRuntime>::default().build_storage().unwrap();
+	sp_io::TestExternalities::new(t)
+}
+
+/// Run pallet test.
+pub fn run_test<T>(test: impl FnOnce() -> T) -> T {
+	new_test_ext().execute_with(|| test())
+}

cumulus/bridges/modules/xcm-bridge-hub-router/src/weights.rs

@@ -0,0 +1,208 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Autogenerated weights for pallet_xcm_bridge_hub_router
+//!
+//! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
+//! DATE: 2023-08-03, STEPS: `50`, REPEAT: `20`, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! WORST CASE MAP SIZE: `1000000`
+//! HOSTNAME: `covid`, CPU: `11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz`
+//! EXECUTION: , WASM-EXECUTION: Compiled, CHAIN: Some("dev"), DB CACHE: 1024
+
+// Executed Command:
+// target/release/millau-bridge-node
+// benchmark
+// pallet
+// --chain=dev
+// --steps=50
+// --repeat=20
+// --pallet=pallet_xcm_bridge_hub_router
+// --extrinsic=*
+// --execution=wasm
+// --wasm-execution=Compiled
+// --heap-pages=4096
+// --output=./modules/xcm-bridge-hub-router/src/weights.rs
+// --template=./.maintain/bridge-weight-template.hbs
+
+#![allow(clippy::all)]
+#![allow(unused_parens)]
+#![allow(unused_imports)]
+#![allow(missing_docs)]
+
+use frame_support::{
+	traits::Get,
+	weights::{constants::RocksDbWeight, Weight},
+};
+use sp_std::marker::PhantomData;
+
+/// Weight functions needed for pallet_xcm_bridge_hub_router.
+pub trait WeightInfo {
+	fn on_initialize_when_non_congested() -> Weight;
+	fn on_initialize_when_congested() -> Weight;
+	fn report_bridge_status() -> Weight;
+	fn send_message() -> Weight;
+}
+
+/// Weights for `pallet_xcm_bridge_hub_router` that are generated using one of the Bridge testnets.
+///
+/// Those weights are test only and must never be used in production.
+pub struct BridgeWeight<T>(PhantomData<T>);
+impl<T: frame_system::Config> WeightInfo for BridgeWeight<T> {
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn on_initialize_when_non_congested() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `53`
+		//  Estimated: `3518`
+		// Minimum execution time: 11_934 nanoseconds.
+		Weight::from_parts(12_201_000, 3518)
+			.saturating_add(T::DbWeight::get().reads(2_u64))
+			.saturating_add(T::DbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn on_initialize_when_congested() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `94`
+		//  Estimated: `3559`
+		// Minimum execution time: 9_010 nanoseconds.
+		Weight::from_parts(9_594_000, 3559)
+			.saturating_add(T::DbWeight::get().reads(2_u64))
+			.saturating_add(T::DbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	fn report_bridge_status() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `53`
+		//  Estimated: `1502`
+		// Minimum execution time: 10_427 nanoseconds.
+		Weight::from_parts(10_682_000, 1502)
+			.saturating_add(T::DbWeight::get().reads(1_u64))
+			.saturating_add(T::DbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn send_message() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `52`
+		//  Estimated: `3517`
+		// Minimum execution time: 19_709 nanoseconds.
+		Weight::from_parts(20_110_000, 3517)
+			.saturating_add(T::DbWeight::get().reads(2_u64))
+			.saturating_add(T::DbWeight::get().writes(1_u64))
+	}
+}
+
+// For backwards compatibility and tests
+impl WeightInfo for () {
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn on_initialize_when_non_congested() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `53`
+		//  Estimated: `3518`
+		// Minimum execution time: 11_934 nanoseconds.
+		Weight::from_parts(12_201_000, 3518)
+			.saturating_add(RocksDbWeight::get().reads(2_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn on_initialize_when_congested() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `94`
+		//  Estimated: `3559`
+		// Minimum execution time: 9_010 nanoseconds.
+		Weight::from_parts(9_594_000, 3559)
+			.saturating_add(RocksDbWeight::get().reads(2_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	fn report_bridge_status() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `53`
+		//  Estimated: `1502`
+		// Minimum execution time: 10_427 nanoseconds.
+		Weight::from_parts(10_682_000, 1502)
+			.saturating_add(RocksDbWeight::get().reads(1_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+	/// Storage: `XcmBridgeHubRouter::Bridge` (r:1 w:1)
+	///
+	/// Proof: `XcmBridgeHubRouter::Bridge` (`max_values`: Some(1), `max_size`: Some(17), added:
+	/// 512, mode: `MaxEncodedLen`)
+	///
+	/// Storage: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765`
+	/// (r:1 w:0)
+	///
+	/// Proof: UNKNOWN KEY `0x456d756c617465645369626c696e6758636d704368616e6e656c2e436f6e6765` (r:1
+	/// w:0)
+	fn send_message() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `52`
+		//  Estimated: `3517`
+		// Minimum execution time: 19_709 nanoseconds.
+		Weight::from_parts(20_110_000, 3517)
+			.saturating_add(RocksDbWeight::get().reads(2_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+}