Bridges subtree update (#2602)

## Summary

This PR aligns Rococo/Westend bridge with latest Bridges repo
development:
- https://github.com/paritytech/parity-bridges-common/pull/2727
- https://github.com/paritytech/parity-bridges-common/pull/2728
- https://github.com/paritytech/parity-bridges-common/pull/2729




Part of: https://github.com/paritytech/parity-bridges-common/issues/2452

Cargo.lock

@@ -1817,6 +1817,13 @@ dependencies = [
  "sp-std 8.0.0",
 ]
 
+[[package]]
+name = "bp-xcm-bridge-hub"
+version = "0.1.0"
+dependencies = [
+ "sp-std 8.0.0",
+]
+
 [[package]]
 name = "bp-xcm-bridge-hub-router"
 version = "0.1.0"
@@ -1915,6 +1922,7 @@ dependencies = [
  "pallet-utility",
  "pallet-xcm",
  "pallet-xcm-benchmarks",
+ "pallet-xcm-bridge-hub",
  "parachains-common",
  "parity-scale-codec",
  "polkadot-core-primitives",
@@ -2032,6 +2040,7 @@ dependencies = [
 name = "bridge-hub-westend-runtime"
 version = "0.1.0"
 dependencies = [
+ "bp-asset-hub-rococo",
  "bp-asset-hub-westend",
  "bp-bridge-hub-rococo",
  "bp-bridge-hub-westend",
@@ -2078,6 +2087,7 @@ dependencies = [
  "pallet-utility",
  "pallet-xcm",
  "pallet-xcm-benchmarks",
+ "pallet-xcm-bridge-hub",
  "parachains-common",
  "parity-scale-codec",
  "polkadot-core-primitives",
@@ -2121,6 +2131,7 @@ dependencies = [
  "bp-relayers",
  "bp-runtime",
  "bp-test-utils",
+ "bp-xcm-bridge-hub",
  "bp-xcm-bridge-hub-router",
  "frame-support",
  "frame-system",
@@ -11072,6 +11083,31 @@ dependencies = [
  "staging-xcm-executor",
 ]
 
+[[package]]
+name = "pallet-xcm-bridge-hub"
+version = "0.1.0"
+dependencies = [
+ "bp-header-chain",
+ "bp-messages",
+ "bp-runtime",
+ "bp-xcm-bridge-hub",
+ "bridge-runtime-common",
+ "frame-support",
+ "frame-system",
+ "log",
+ "pallet-balances",
+ "pallet-bridge-messages",
+ "parity-scale-codec",
+ "scale-info",
+ "sp-core",
+ "sp-io",
+ "sp-runtime",
+ "sp-std 8.0.0",
+ "staging-xcm",
+ "staging-xcm-builder",
+ "staging-xcm-executor",
+]
+
 [[package]]
 name = "pallet-xcm-bridge-hub-router"
 version = "0.1.0"

Cargo.toml

@@ -13,6 +13,7 @@ members = [
 	"bridges/modules/messages",
 	"bridges/modules/parachains",
 	"bridges/modules/relayers",
+	"bridges/modules/xcm-bridge-hub",
 	"bridges/modules/xcm-bridge-hub-router",
 	"bridges/primitives/chain-asset-hub-rococo",
 	"bridges/primitives/chain-asset-hub-westend",
@@ -33,6 +34,7 @@ members = [
 	"bridges/primitives/relayers",
 	"bridges/primitives/runtime",
 	"bridges/primitives/test-utils",
+	"bridges/primitives/xcm-bridge-hub",
 	"bridges/primitives/xcm-bridge-hub-router",
 	"cumulus/client/cli",
 	"cumulus/client/collator",

bridges/bin/runtime-common/Cargo.toml

@@ -22,6 +22,7 @@ bp-parachains = { path = "../../primitives/parachains", default-features = false
 bp-polkadot-core = { path = "../../primitives/polkadot-core", default-features = false }
 bp-relayers = { path = "../../primitives/relayers", default-features = false }
 bp-runtime = { path = "../../primitives/runtime", default-features = false }
+bp-xcm-bridge-hub = { path = "../../primitives/xcm-bridge-hub", default-features = false }
 bp-xcm-bridge-hub-router = { path = "../../primitives/xcm-bridge-hub-router", default-features = false }
 pallet-bridge-grandpa = { path = "../../modules/grandpa", default-features = false }
 pallet-bridge-messages = { path = "../../modules/messages", default-features = false }
@@ -59,6 +60,7 @@ std = [
 	"bp-relayers/std",
 	"bp-runtime/std",
 	"bp-xcm-bridge-hub-router/std",
+	"bp-xcm-bridge-hub/std",
 	"codec/std",
 	"frame-support/std",
 	"frame-system/std",

bridges/bin/runtime-common/src/messages_xcm_extension.rs

@@ -22,26 +22,23 @@
 //! `XcmRouter` <- `MessageDispatch` <- `InboundMessageQueue`
 
 use bp_messages::{
-	source_chain::{MessagesBridge, OnMessagesDelivered},
+	source_chain::OnMessagesDelivered,
 	target_chain::{DispatchMessage, MessageDispatch},
 	LaneId, MessageNonce,
 };
 use bp_runtime::messages::MessageDispatchResult;
+pub use bp_xcm_bridge_hub::XcmAsPlainPayload;
 use bp_xcm_bridge_hub_router::XcmChannelStatusProvider;
 use codec::{Decode, Encode};
 use frame_support::{traits::Get, weights::Weight, CloneNoBound, EqNoBound, PartialEqNoBound};
 use pallet_bridge_messages::{
-	Config as MessagesConfig, OutboundLanesCongestedSignals, Pallet as MessagesPallet,
-	WeightInfoExt as MessagesPalletWeights,
+	Config as MessagesConfig, OutboundLanesCongestedSignals, WeightInfoExt as MessagesPalletWeights,
 };
 use scale_info::TypeInfo;
 use sp_runtime::SaturatedConversion;
 use sp_std::{fmt::Debug, marker::PhantomData};
 use xcm::prelude::*;
-use xcm_builder::{DispatchBlob, DispatchBlobError, HaulBlob, HaulBlobError};
-
-/// Plain "XCM" payload, which we transfer through bridge
-pub type XcmAsPlainPayload = sp_std::prelude::Vec<u8>;
+use xcm_builder::{DispatchBlob, DispatchBlobError};
 
 /// Message dispatch result type for single message
 #[derive(CloneNoBound, EqNoBound, PartialEqNoBound, Encode, Decode, Debug, TypeInfo)]
@@ -123,6 +120,7 @@ impl<
 
 /// A pair of sending chain location and message lane, used by this chain to send messages
 /// over the bridge.
+#[cfg_attr(feature = "std", derive(Debug, Eq, PartialEq))]
 pub struct SenderAndLane {
 	/// Sending chain relative location.
 	pub location: MultiLocation,
@@ -144,8 +142,6 @@ pub trait XcmBlobHauler {
 	type Runtime: MessagesConfig<Self::MessagesInstance>;
 	/// Instance of the messages pallet that is used to send messages.
 	type MessagesInstance: 'static;
-	/// Returns lane used by this hauler.
-	type SenderAndLane: Get<SenderAndLane>;
 
 	/// Actual XCM message sender (`HRMP` or `UMP`) to the source chain
 	/// location (`Self::SenderAndLane::get().location`).
@@ -166,54 +162,25 @@ pub trait XcmBlobHauler {
 /// makes sure that XCM blob is sent to the outbound lane to be relayed.
 ///
 /// It needs to be used at the source bridge hub.
-pub struct XcmBlobHaulerAdapter<XcmBlobHauler>(sp_std::marker::PhantomData<XcmBlobHauler>);
+pub struct XcmBlobHaulerAdapter<XcmBlobHauler, Lanes>(
+	sp_std::marker::PhantomData<(XcmBlobHauler, Lanes)>,
+);
 
-impl<H: XcmBlobHauler> HaulBlob for XcmBlobHaulerAdapter<H>
-where
-	H::Runtime: MessagesConfig<H::MessagesInstance, OutboundPayload = XcmAsPlainPayload>,
+impl<
+		H: XcmBlobHauler,
+		Lanes: Get<sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))>>,
+	> OnMessagesDelivered for XcmBlobHaulerAdapter<H, Lanes>
 {
-	fn haul_blob(blob: sp_std::prelude::Vec<u8>) -> Result<(), HaulBlobError> {
-		let sender_and_lane = H::SenderAndLane::get();
-		MessagesPallet::<H::Runtime, H::MessagesInstance>::send_message(sender_and_lane.lane, blob)
-			.map(|artifacts| {
-				log::info!(
-					target: crate::LOG_TARGET_BRIDGE_DISPATCH,
-					"haul_blob result - ok: {:?} on lane: {:?}. Enqueued messages: {}",
-					artifacts.nonce,
-					sender_and_lane.lane,
-					artifacts.enqueued_messages,
-				);
-
-				// notify XCM queue manager about updated lane state
-				LocalXcmQueueManager::<H>::on_bridge_message_enqueued(
-					&sender_and_lane,
-					artifacts.enqueued_messages,
-				);
-			})
-			.map_err(|error| {
-				log::error!(
-					target: crate::LOG_TARGET_BRIDGE_DISPATCH,
-					"haul_blob result - error: {:?} on lane: {:?}",
-					error,
-					sender_and_lane.lane,
-				);
-				HaulBlobError::Transport("MessageSenderError")
-			})
-	}
-}
-
-impl<H: XcmBlobHauler> OnMessagesDelivered for XcmBlobHaulerAdapter<H> {
 	fn on_messages_delivered(lane: LaneId, enqueued_messages: MessageNonce) {
-		let sender_and_lane = H::SenderAndLane::get();
-		if sender_and_lane.lane != lane {
-			return
+		if let Some(sender_and_lane) =
+			Lanes::get().iter().find(|link| link.0.lane == lane).map(|link| &link.0)
+		{
+			// notify XCM queue manager about updated lane state
+			LocalXcmQueueManager::<H>::on_bridge_messages_delivered(
+				sender_and_lane,
+				enqueued_messages,
+			);
 		}
-
-		// notify XCM queue manager about updated lane state
-		LocalXcmQueueManager::<H>::on_bridge_messages_delivered(
-			&sender_and_lane,
-			enqueued_messages,
-		);
 	}
 }
 
@@ -356,6 +323,9 @@ mod tests {
 			location: MultiLocation::new(1, X1(Parachain(1000))),
 			lane: TEST_LANE_ID,
 		};
+		pub TestLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+			(TestSenderAndLane::get(), (NetworkId::ByGenesis([0; 32]), InteriorMultiLocation::Here))
+		];
 		pub DummyXcmMessage: Xcm<()> = Xcm::new();
 	}
 
@@ -389,37 +359,44 @@ mod tests {
 	impl XcmBlobHauler for TestBlobHauler {
 		type Runtime = TestRuntime;
 		type MessagesInstance = ();
-		type SenderAndLane = TestSenderAndLane;
 
 		type ToSourceChainSender = DummySendXcm;
 		type CongestedMessage = DummyXcmMessage;
 		type UncongestedMessage = DummyXcmMessage;
 	}
 
-	type TestBlobHaulerAdapter = XcmBlobHaulerAdapter<TestBlobHauler>;
+	type TestBlobHaulerAdapter = XcmBlobHaulerAdapter<TestBlobHauler, TestLanes>;
 
-	fn fill_up_lane_to_congestion() {
+	fn fill_up_lane_to_congestion() -> MessageNonce {
+		let latest_generated_nonce = OUTBOUND_LANE_CONGESTED_THRESHOLD;
 		OutboundLanes::<TestRuntime, ()>::insert(
 			TEST_LANE_ID,
 			OutboundLaneData {
 				oldest_unpruned_nonce: 0,
 				latest_received_nonce: 0,
-				latest_generated_nonce: OUTBOUND_LANE_CONGESTED_THRESHOLD,
+				latest_generated_nonce,
 			},
 		);
+		latest_generated_nonce
 	}
 
 	#[test]
 	fn congested_signal_is_not_sent_twice() {
 		run_test(|| {
-			fill_up_lane_to_congestion();
+			let enqueued = fill_up_lane_to_congestion();
 
 			// next sent message leads to congested signal
-			TestBlobHaulerAdapter::haul_blob(vec![42]).unwrap();
+			LocalXcmQueueManager::<TestBlobHauler>::on_bridge_message_enqueued(
+				&TestSenderAndLane::get(),
+				enqueued + 1,
+			);
 			assert_eq!(DummySendXcm::messages_sent(), 1);
 
 			// next sent message => we don't sent another congested signal
-			TestBlobHaulerAdapter::haul_blob(vec![42]).unwrap();
+			LocalXcmQueueManager::<TestBlobHauler>::on_bridge_message_enqueued(
+				&TestSenderAndLane::get(),
+				enqueued,
+			);
 			assert_eq!(DummySendXcm::messages_sent(), 1);
 		});
 	}
@@ -427,7 +404,10 @@ mod tests {
 	#[test]
 	fn congested_signal_is_not_sent_when_outbound_lane_is_not_congested() {
 		run_test(|| {
-			TestBlobHaulerAdapter::haul_blob(vec![42]).unwrap();
+			LocalXcmQueueManager::<TestBlobHauler>::on_bridge_message_enqueued(
+				&TestSenderAndLane::get(),
+				1,
+			);
 			assert_eq!(DummySendXcm::messages_sent(), 0);
 		});
 	}
@@ -435,10 +415,13 @@ mod tests {
 	#[test]
 	fn congested_signal_is_sent_when_outbound_lane_is_congested() {
 		run_test(|| {
-			fill_up_lane_to_congestion();
+			let enqueued = fill_up_lane_to_congestion();
 
 			// next sent message leads to congested signal
-			TestBlobHaulerAdapter::haul_blob(vec![42]).unwrap();
+			LocalXcmQueueManager::<TestBlobHauler>::on_bridge_message_enqueued(
+				&TestSenderAndLane::get(),
+				enqueued + 1,
+			);
 			assert_eq!(DummySendXcm::messages_sent(), 1);
 			assert!(LocalXcmQueueManager::<TestBlobHauler>::is_congested_signal_sent(TEST_LANE_ID));
 		});

bridges/bin/runtime-common/src/mock.rs

@@ -376,8 +376,8 @@ impl ChainWithGrandpa for BridgedUnderlyingChain {
 	const WITH_CHAIN_GRANDPA_PALLET_NAME: &'static str = "";
 	const MAX_AUTHORITIES_COUNT: u32 = 16;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 8;
-	const MAX_HEADER_SIZE: u32 = 256;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = 64;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = 256;
+	const AVERAGE_HEADER_SIZE: u32 = 64;
 }
 
 impl Chain for BridgedUnderlyingParachain {

bridges/modules/grandpa/src/call_ext.rs

@@ -15,7 +15,10 @@
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
 use crate::{weights::WeightInfo, BridgedBlockNumber, BridgedHeader, Config, Error, Pallet};
-use bp_header_chain::{justification::GrandpaJustification, ChainWithGrandpa};
+use bp_header_chain::{
+	justification::GrandpaJustification, max_expected_submit_finality_proof_arguments_size,
+	ChainWithGrandpa, GrandpaConsensusLogReader,
+};
 use bp_runtime::{BlockNumberOf, OwnedBridgeModule};
 use codec::Encode;
 use frame_support::{dispatch::CallableCallFor, traits::IsSubType, weights::Weight};
@@ -169,28 +172,28 @@ pub(crate) fn submit_finality_proof_info_from_args<T: Config<I>, I: 'static>(
 			Weight::zero()
 		};
 
+	// check if the `finality_target` is a mandatory header. If so, we are ready to refund larger
+	// size
+	let is_mandatory_finality_target =
+		GrandpaConsensusLogReader::<BridgedBlockNumber<T, I>>::find_scheduled_change(
+			finality_target.digest(),
+		)
+		.is_some();
+
 	// we can estimate extra call size easily, without any additional significant overhead
 	let actual_call_size: u32 = finality_target
 		.encoded_size()
 		.saturating_add(justification.encoded_size())
 		.saturated_into();
-	let max_expected_call_size = max_expected_call_size::<T, I>(required_precommits);
+	let max_expected_call_size = max_expected_submit_finality_proof_arguments_size::<T::BridgedChain>(
+		is_mandatory_finality_target,
+		required_precommits,
+	);
 	let extra_size = actual_call_size.saturating_sub(max_expected_call_size);
 
 	SubmitFinalityProofInfo { block_number, extra_weight, extra_size }
 }
 
-/// Returns maximal expected size of `submit_finality_proof` call arguments.
-fn max_expected_call_size<T: Config<I>, I: 'static>(required_precommits: u32) -> u32 {
-	let max_expected_justification_size =
-		GrandpaJustification::<BridgedHeader<T, I>>::max_reasonable_size::<T::BridgedChain>(
-			required_precommits,
-		);
-
-	// call arguments are header and justification
-	T::BridgedChain::MAX_HEADER_SIZE.saturating_add(max_expected_justification_size)
-}
-
 #[cfg(test)]
 mod tests {
 	use crate::{

bridges/modules/grandpa/src/mock.rs

@@ -86,8 +86,8 @@ impl ChainWithGrandpa for TestBridgedChain {
 	const WITH_CHAIN_GRANDPA_PALLET_NAME: &'static str = "";
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_BRIDGED_AUTHORITIES;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 8;
-	const MAX_HEADER_SIZE: u32 = 256;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = 64;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = 256;
+	const AVERAGE_HEADER_SIZE: u32 = 64;
 }
 
 /// Return test externalities to use in tests.

bridges/modules/parachains/src/mock.rs

@@ -252,8 +252,8 @@ impl ChainWithGrandpa for TestBridgedChain {
 	const WITH_CHAIN_GRANDPA_PALLET_NAME: &'static str = "";
 	const MAX_AUTHORITIES_COUNT: u32 = 16;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 8;
-	const MAX_HEADER_SIZE: u32 = 256;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = 64;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = 256;
+	const AVERAGE_HEADER_SIZE: u32 = 64;
 }
 
 #[derive(Debug)]
@@ -283,8 +283,8 @@ impl ChainWithGrandpa for OtherBridgedChain {
 	const WITH_CHAIN_GRANDPA_PALLET_NAME: &'static str = "";
 	const MAX_AUTHORITIES_COUNT: u32 = 16;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 8;
-	const MAX_HEADER_SIZE: u32 = 256;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = 64;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = 256;
+	const AVERAGE_HEADER_SIZE: u32 = 64;
 }
 
 /// Return test externalities to use in tests.

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

@@ -0,0 +1,74 @@
+[package]
+name = "pallet-xcm-bridge-hub"
+description = "Module that adds dynamic bridges/lanes support to XCM infrastucture at the bridge hub."
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+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 = "0.4.20", default-features = false }
+scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
+
+# Bridge Dependencies
+bp-messages = { path = "../../primitives/messages", default-features = false }
+bp-runtime = { path = "../../primitives/runtime", default-features = false }
+bp-xcm-bridge-hub = { path = "../../primitives/xcm-bridge-hub", default-features = false }
+pallet-bridge-messages = { path = "../messages", default-features = false }
+bridge-runtime-common = { path = "../../bin/runtime-common", default-features = false }
+
+# Substrate Dependencies
+frame-support = { path = "../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../substrate/frame/system", default-features = false }
+sp-core = { path = "../../../substrate/primitives/core", default-features = false }
+sp-runtime = { path = "../../../substrate/primitives/runtime", default-features = false }
+sp-std = { path = "../../../substrate/primitives/std", default-features = false }
+
+# Polkadot Dependencies
+xcm = { package = "staging-xcm", path = "../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../polkadot/xcm/xcm-builder", default-features = false }
+xcm-executor = { package = "staging-xcm-executor", path = "../../../polkadot/xcm/xcm-executor", default-features = false }
+
+[dev-dependencies]
+bp-header-chain = { path = "../../primitives/header-chain" }
+pallet-balances = { path = "../../../substrate/frame/balances" }
+sp-io = { path = "../../../substrate/primitives/io" }
+
+[features]
+default = ["std"]
+std = [
+	"bp-messages/std",
+	"bp-runtime/std",
+	"bp-xcm-bridge-hub/std",
+	"bridge-runtime-common/std",
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"pallet-bridge-messages/std",
+	"scale-info/std",
+	"sp-core/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"bridge-runtime-common/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
+	"pallet-bridge-messages/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+	"xcm-executor/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
+	"pallet-bridge-messages/try-runtime",
+	"sp-runtime/try-runtime",
+]

bridges/modules/xcm-bridge-hub/src/exporter.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/>.
+
+//! The code that allows to use the pallet (`pallet-xcm-bridge-hub`) as XCM message
+//! exporter at the sending bridge hub. Internally, it just enqueues outbound blob
+//! in the messages pallet queue.
+//!
+//! This code is executed at the source bridge hub.
+
+use crate::{Config, Pallet, LOG_TARGET};
+
+use bp_messages::source_chain::MessagesBridge;
+use bp_xcm_bridge_hub::XcmAsPlainPayload;
+use bridge_runtime_common::messages_xcm_extension::{LocalXcmQueueManager, SenderAndLane};
+use pallet_bridge_messages::{Config as BridgeMessagesConfig, Pallet as BridgeMessagesPallet};
+use xcm::prelude::*;
+use xcm_builder::{HaulBlob, HaulBlobError, HaulBlobExporter};
+use xcm_executor::traits::ExportXcm;
+
+/// An easy way to access `HaulBlobExporter`.
+pub type PalletAsHaulBlobExporter<T, I> = HaulBlobExporter<
+	DummyHaulBlob,
+	<T as Config<I>>::BridgedNetworkId,
+	<T as Config<I>>::MessageExportPrice,
+>;
+/// An easy way to access associated messages pallet.
+type MessagesPallet<T, I> = BridgeMessagesPallet<T, <T as Config<I>>::BridgeMessagesPalletInstance>;
+
+impl<T: Config<I>, I: 'static> ExportXcm for Pallet<T, I>
+where
+	T: BridgeMessagesConfig<
+		<T as Config<I>>::BridgeMessagesPalletInstance,
+		OutboundPayload = XcmAsPlainPayload,
+	>,
+{
+	type Ticket = (SenderAndLane, XcmAsPlainPayload, XcmHash);
+
+	fn validate(
+		network: NetworkId,
+		channel: u32,
+		universal_source: &mut Option<InteriorMultiLocation>,
+		destination: &mut Option<InteriorMultiLocation>,
+		message: &mut Option<Xcm<()>>,
+	) -> Result<(Self::Ticket, MultiAssets), SendError> {
+		// Find supported lane_id.
+		let sender_and_lane = Self::lane_for(
+			universal_source.as_ref().ok_or(SendError::MissingArgument)?,
+			(&network, destination.as_ref().ok_or(SendError::MissingArgument)?),
+		)
+		.ok_or(SendError::NotApplicable)?;
+
+		// check if we are able to route the message. We use existing `HaulBlobExporter` for that.
+		// It will make all required changes and will encode message properly, so that the
+		// `DispatchBlob` at the bridged bridge hub will be able to decode it
+		let ((blob, id), price) = PalletAsHaulBlobExporter::<T, I>::validate(
+			network,
+			channel,
+			universal_source,
+			destination,
+			message,
+		)?;
+
+		Ok(((sender_and_lane, blob, id), price))
+	}
+
+	fn deliver(
+		(sender_and_lane, blob, id): (SenderAndLane, XcmAsPlainPayload, XcmHash),
+	) -> Result<XcmHash, SendError> {
+		let lane_id = sender_and_lane.lane;
+		let send_result = MessagesPallet::<T, I>::send_message(lane_id, blob);
+
+		match send_result {
+			Ok(artifacts) => {
+				log::info!(
+					target: LOG_TARGET,
+					"XCM message {:?} has been enqueued at bridge {:?} with nonce {}",
+					id,
+					lane_id,
+					artifacts.nonce,
+				);
+
+				// notify XCM queue manager about updated lane state
+				LocalXcmQueueManager::<T::LanesSupport>::on_bridge_message_enqueued(
+					&sender_and_lane,
+					artifacts.enqueued_messages,
+				);
+			},
+			Err(error) => {
+				log::debug!(
+					target: LOG_TARGET,
+					"XCM message {:?} has been dropped because of bridge error {:?} on bridge {:?}",
+					id,
+					error,
+					lane_id,
+				);
+				return Err(SendError::Transport("BridgeSendError"))
+			},
+		}
+
+		Ok(id)
+	}
+}
+
+/// Dummy implementation of the `HaulBlob` trait that is never called.
+///
+/// We are using `HaulBlobExporter`, which requires `HaulBlob` implementation. It assumes that
+/// there's a single channel between two bridge hubs - `HaulBlob` only accepts the blob and nothing
+/// else. But bridge messages pallet may have a dedicated channel (lane) for every pair of bridged
+/// chains. So we are using our own `ExportXcm` implementation, but to utilize `HaulBlobExporter` we
+/// still need this `DummyHaulBlob`.
+pub struct DummyHaulBlob;
+
+impl HaulBlob for DummyHaulBlob {
+	fn haul_blob(_blob: XcmAsPlainPayload) -> Result<(), HaulBlobError> {
+		Err(HaulBlobError::Transport("DummyHaulBlob"))
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use crate::mock::*;
+	use frame_support::assert_ok;
+	use xcm_executor::traits::export_xcm;
+
+	fn universal_source() -> InteriorMultiLocation {
+		X2(GlobalConsensus(RelayNetwork::get()), Parachain(SIBLING_ASSET_HUB_ID))
+	}
+
+	fn universal_destination() -> InteriorMultiLocation {
+		BridgedDestination::get()
+	}
+
+	#[test]
+	fn export_works() {
+		run_test(|| {
+			assert_ok!(export_xcm::<XcmOverBridge>(
+				BridgedRelayNetwork::get(),
+				0,
+				universal_source(),
+				universal_destination(),
+				vec![Instruction::ClearOrigin].into(),
+			));
+		})
+	}
+
+	#[test]
+	fn export_fails_if_argument_is_missing() {
+		run_test(|| {
+			assert_eq!(
+				XcmOverBridge::validate(
+					BridgedRelayNetwork::get(),
+					0,
+					&mut None,
+					&mut Some(universal_destination()),
+					&mut Some(Vec::new().into()),
+				),
+				Err(SendError::MissingArgument),
+			);
+
+			assert_eq!(
+				XcmOverBridge::validate(
+					BridgedRelayNetwork::get(),
+					0,
+					&mut Some(universal_source()),
+					&mut None,
+					&mut Some(Vec::new().into()),
+				),
+				Err(SendError::MissingArgument),
+			);
+		})
+	}
+
+	#[test]
+	fn exporter_computes_correct_lane_id() {
+		run_test(|| {
+			let expected_lane_id = TEST_LANE_ID;
+
+			assert_eq!(
+				XcmOverBridge::validate(
+					BridgedRelayNetwork::get(),
+					0,
+					&mut Some(universal_source()),
+					&mut Some(universal_destination()),
+					&mut Some(Vec::new().into()),
+				)
+				.unwrap()
+				.0
+				 .0
+				.lane,
+				expected_lane_id,
+			);
+		})
+	}
+}

bridges/modules/xcm-bridge-hub/src/lib.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/>.
+
+//! Module that adds XCM support to bridge pallets.
+
+#![warn(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use bridge_runtime_common::messages_xcm_extension::XcmBlobHauler;
+use pallet_bridge_messages::Config as BridgeMessagesConfig;
+use xcm::prelude::*;
+
+pub use exporter::PalletAsHaulBlobExporter;
+pub use pallet::*;
+
+mod exporter;
+mod mock;
+
+/// The target that will be used when publishing logs related to this pallet.
+pub const LOG_TARGET: &str = "runtime::bridge-xcm";
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+	use bridge_runtime_common::messages_xcm_extension::SenderAndLane;
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::config]
+	#[pallet::disable_frame_system_supertrait_check]
+	pub trait Config<I: 'static = ()>:
+		BridgeMessagesConfig<Self::BridgeMessagesPalletInstance>
+	{
+		/// Runtime's universal location.
+		type UniversalLocation: Get<InteriorMultiLocation>;
+		// TODO: https://github.com/paritytech/parity-bridges-common/issues/1666 remove `ChainId` and
+		// replace it with the `NetworkId` - then we'll be able to use
+		// `T as pallet_bridge_messages::Config<T::BridgeMessagesPalletInstance>::BridgedChain::NetworkId`
+		/// Bridged network id.
+		#[pallet::constant]
+		type BridgedNetworkId: Get<NetworkId>;
+		/// Associated messages pallet instance that bridges us with the
+		/// `BridgedNetworkId` consensus.
+		type BridgeMessagesPalletInstance: 'static;
+
+		/// Price of single message export to the bridged consensus (`Self::BridgedNetworkId`).
+		type MessageExportPrice: Get<MultiAssets>;
+
+		/// Get point-to-point links with bridged consensus (`Self::BridgedNetworkId`).
+		/// (this will be replaced with dynamic on-chain bridges - `Bridges V2`)
+		type Lanes: Get<sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))>>;
+		/// Support for point-to-point links
+		/// (this will be replaced with dynamic on-chain bridges - `Bridges V2`)
+		type LanesSupport: XcmBlobHauler;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T, I = ()>(PhantomData<(T, I)>);
+
+	impl<T: Config<I>, I: 'static> Pallet<T, I> {
+		/// Returns dedicated/configured lane identifier.
+		pub(crate) fn lane_for(
+			source: &InteriorMultiLocation,
+			dest: (&NetworkId, &InteriorMultiLocation),
+		) -> Option<SenderAndLane> {
+			let source = source.relative_to(&T::UniversalLocation::get());
+
+			// Check that we have configured a point-to-point lane for 'source' and `dest`.
+			T::Lanes::get()
+				.into_iter()
+				.find_map(|(lane_source, (lane_dest_network, lane_dest))| {
+					if lane_source.location == source &&
+						&lane_dest_network == dest.0 &&
+						&T::BridgedNetworkId::get() == dest.0 &&
+						&lane_dest == dest.1
+					{
+						Some(lane_source)
+					} else {
+						None
+					}
+				})
+		}
+	}
+}

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

@@ -0,0 +1,328 @@
+// 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;
+
+use bp_messages::{
+	source_chain::LaneMessageVerifier,
+	target_chain::{DispatchMessage, MessageDispatch},
+	LaneId, OutboundLaneData, VerificationError,
+};
+use bp_runtime::{messages::MessageDispatchResult, Chain, UnderlyingChainProvider};
+use bridge_runtime_common::{
+	messages::{
+		source::TargetHeaderChainAdapter, target::SourceHeaderChainAdapter,
+		BridgedChainWithMessages, HashOf, MessageBridge, ThisChainWithMessages,
+	},
+	messages_xcm_extension::{SenderAndLane, XcmBlobHauler},
+};
+use codec::Encode;
+use frame_support::{derive_impl, parameter_types, traits::ConstU32, weights::RuntimeDbWeight};
+use sp_core::H256;
+use sp_runtime::{
+	testing::Header as SubstrateHeader,
+	traits::{BlakeTwo256, IdentityLookup},
+	AccountId32, BuildStorage,
+};
+use xcm::prelude::*;
+
+pub type AccountId = AccountId32;
+pub type Balance = u64;
+
+type Block = frame_system::mocking::MockBlock<TestRuntime>;
+
+pub const SIBLING_ASSET_HUB_ID: u32 = 2001;
+pub const THIS_BRIDGE_HUB_ID: u32 = 2002;
+pub const BRIDGED_ASSET_HUB_ID: u32 = 1001;
+pub const TEST_LANE_ID: LaneId = LaneId([0, 0, 0, 1]);
+
+frame_support::construct_runtime! {
+	pub enum TestRuntime {
+		System: frame_system::{Pallet, Call, Config<T>, Storage, Event<T>},
+		Balances: pallet_balances::{Pallet, Event<T>},
+		Messages: pallet_bridge_messages::{Pallet, Call, Event<T>},
+		XcmOverBridge: pallet_xcm_bridge_hub::{Pallet},
+	}
+}
+
+parameter_types! {
+	pub const DbWeight: RuntimeDbWeight = RuntimeDbWeight { read: 1, write: 2 };
+	pub const ExistentialDeposit: Balance = 1;
+}
+
+#[derive_impl(frame_system::config_preludes::TestDefaultConfig as frame_system::DefaultConfig)]
+impl frame_system::Config for TestRuntime {
+	type AccountId = AccountId;
+	type AccountData = pallet_balances::AccountData<Balance>;
+	type Block = Block;
+	type Lookup = IdentityLookup<Self::AccountId>;
+}
+
+#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig as pallet_balances::DefaultConfig)]
+impl pallet_balances::Config for TestRuntime {
+	type AccountStore = System;
+}
+
+/// Lane message verifier that is used in tests.
+#[derive(Debug, Default)]
+pub struct TestLaneMessageVerifier;
+
+impl LaneMessageVerifier<Vec<u8>> for TestLaneMessageVerifier {
+	fn verify_message(
+		_lane: &LaneId,
+		_lane_outbound_data: &OutboundLaneData,
+		_payload: &Vec<u8>,
+	) -> Result<(), VerificationError> {
+		Ok(())
+	}
+}
+
+parameter_types! {
+	pub const ActiveOutboundLanes: &'static [LaneId] = &[TEST_LANE_ID];
+}
+
+impl pallet_bridge_messages::Config for TestRuntime {
+	type RuntimeEvent = RuntimeEvent;
+	type WeightInfo = TestMessagesWeights;
+
+	type BridgedChainId = ();
+	type ActiveOutboundLanes = ActiveOutboundLanes;
+	type MaxUnrewardedRelayerEntriesAtInboundLane = ();
+	type MaxUnconfirmedMessagesAtInboundLane = ();
+	type MaximalOutboundPayloadSize = ConstU32<2048>;
+	type OutboundPayload = Vec<u8>;
+	type InboundPayload = Vec<u8>;
+	type InboundRelayer = ();
+	type DeliveryPayments = ();
+	type TargetHeaderChain = TargetHeaderChainAdapter<OnThisChainBridge>;
+	type LaneMessageVerifier = TestLaneMessageVerifier;
+	type DeliveryConfirmationPayments = ();
+	type OnMessagesDelivered = ();
+	type SourceHeaderChain = SourceHeaderChainAdapter<OnThisChainBridge>;
+	type MessageDispatch = TestMessageDispatch;
+}
+
+pub struct TestMessagesWeights;
+
+impl pallet_bridge_messages::WeightInfo for TestMessagesWeights {
+	fn receive_single_message_proof() -> Weight {
+		Weight::zero()
+	}
+	fn receive_single_message_proof_with_outbound_lane_state() -> Weight {
+		Weight::zero()
+	}
+	fn receive_delivery_proof_for_single_message() -> Weight {
+		Weight::zero()
+	}
+	fn receive_delivery_proof_for_two_messages_by_single_relayer() -> Weight {
+		Weight::zero()
+	}
+	fn receive_delivery_proof_for_two_messages_by_two_relayers() -> Weight {
+		Weight::zero()
+	}
+
+	fn receive_two_messages_proof() -> Weight {
+		Weight::zero()
+	}
+
+	fn receive_single_message_proof_1_kb() -> Weight {
+		Weight::zero()
+	}
+
+	fn receive_single_message_proof_16_kb() -> Weight {
+		Weight::zero()
+	}
+
+	fn receive_single_message_proof_with_dispatch(_: u32) -> Weight {
+		Weight::from_parts(1, 0)
+	}
+}
+
+impl pallet_bridge_messages::WeightInfoExt for TestMessagesWeights {
+	fn expected_extra_storage_proof_size() -> u32 {
+		0
+	}
+
+	fn receive_messages_proof_overhead_from_runtime() -> Weight {
+		Weight::zero()
+	}
+
+	fn receive_messages_delivery_proof_overhead_from_runtime() -> Weight {
+		Weight::zero()
+	}
+}
+
+parameter_types! {
+	pub const RelayNetwork: NetworkId = NetworkId::Kusama;
+	pub const BridgedRelayNetwork: NetworkId = NetworkId::Polkadot;
+	pub const NonBridgedRelayNetwork: NetworkId = NetworkId::Rococo;
+	pub const BridgeReserve: Balance = 100_000;
+	pub UniversalLocation: InteriorMultiLocation = X2(
+		GlobalConsensus(RelayNetwork::get()),
+		Parachain(THIS_BRIDGE_HUB_ID),
+	);
+	pub const Penalty: Balance = 1_000;
+}
+
+impl pallet_xcm_bridge_hub::Config for TestRuntime {
+	type UniversalLocation = UniversalLocation;
+	type BridgedNetworkId = BridgedRelayNetwork;
+	type BridgeMessagesPalletInstance = ();
+
+	type MessageExportPrice = ();
+	type Lanes = TestLanes;
+	type LanesSupport = TestXcmBlobHauler;
+}
+
+parameter_types! {
+	pub TestSenderAndLane: SenderAndLane = SenderAndLane {
+		location: MultiLocation::new(1, X1(Parachain(SIBLING_ASSET_HUB_ID))),
+		lane: TEST_LANE_ID,
+	};
+	pub const BridgedDestination: InteriorMultiLocation = X1(
+		Parachain(BRIDGED_ASSET_HUB_ID)
+	);
+	pub TestLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+		(TestSenderAndLane::get(), (BridgedRelayNetwork::get(), BridgedDestination::get()))
+	];
+}
+
+pub struct TestXcmBlobHauler;
+impl XcmBlobHauler for TestXcmBlobHauler {
+	type Runtime = TestRuntime;
+	type MessagesInstance = ();
+	type ToSourceChainSender = ();
+	type CongestedMessage = ();
+	type UncongestedMessage = ();
+}
+
+pub struct ThisChain;
+
+impl Chain for ThisChain {
+	type BlockNumber = u64;
+	type Hash = H256;
+	type Hasher = BlakeTwo256;
+	type Header = SubstrateHeader;
+	type AccountId = AccountId;
+	type Balance = Balance;
+	type Nonce = u64;
+	type Signature = sp_runtime::MultiSignature;
+
+	fn max_extrinsic_size() -> u32 {
+		u32::MAX
+	}
+
+	fn max_extrinsic_weight() -> Weight {
+		Weight::MAX
+	}
+}
+
+pub struct BridgedChain;
+pub type BridgedHeaderHash = H256;
+pub type BridgedChainHeader = SubstrateHeader;
+
+impl Chain for BridgedChain {
+	type BlockNumber = u64;
+	type Hash = BridgedHeaderHash;
+	type Hasher = BlakeTwo256;
+	type Header = BridgedChainHeader;
+	type AccountId = AccountId;
+	type Balance = Balance;
+	type Nonce = u64;
+	type Signature = sp_runtime::MultiSignature;
+
+	fn max_extrinsic_size() -> u32 {
+		4096
+	}
+
+	fn max_extrinsic_weight() -> Weight {
+		Weight::MAX
+	}
+}
+
+/// Test message dispatcher.
+pub struct TestMessageDispatch;
+
+impl TestMessageDispatch {
+	pub fn deactivate(lane: LaneId) {
+		frame_support::storage::unhashed::put(&(b"inactive", lane).encode()[..], &false);
+	}
+}
+
+impl MessageDispatch for TestMessageDispatch {
+	type DispatchPayload = Vec<u8>;
+	type DispatchLevelResult = ();
+
+	fn is_active() -> bool {
+		frame_support::storage::unhashed::take::<bool>(&(b"inactive").encode()[..]) != Some(false)
+	}
+
+	fn dispatch_weight(_message: &mut DispatchMessage<Self::DispatchPayload>) -> Weight {
+		Weight::zero()
+	}
+
+	fn dispatch(
+		_: DispatchMessage<Self::DispatchPayload>,
+	) -> MessageDispatchResult<Self::DispatchLevelResult> {
+		MessageDispatchResult { unspent_weight: Weight::zero(), dispatch_level_result: () }
+	}
+}
+
+pub struct WrappedThisChain;
+impl UnderlyingChainProvider for WrappedThisChain {
+	type Chain = ThisChain;
+}
+impl ThisChainWithMessages for WrappedThisChain {
+	type RuntimeOrigin = RuntimeOrigin;
+}
+
+pub struct WrappedBridgedChain;
+impl UnderlyingChainProvider for WrappedBridgedChain {
+	type Chain = BridgedChain;
+}
+impl BridgedChainWithMessages for WrappedBridgedChain {}
+
+pub struct BridgedHeaderChain;
+impl bp_header_chain::HeaderChain<BridgedChain> for BridgedHeaderChain {
+	fn finalized_header_state_root(
+		_hash: HashOf<WrappedBridgedChain>,
+	) -> Option<HashOf<WrappedBridgedChain>> {
+		unreachable!()
+	}
+}
+
+/// Bridge that is deployed on `ThisChain` and allows sending/receiving messages to/from
+/// `BridgedChain`.
+#[derive(Debug, PartialEq, Eq)]
+pub struct OnThisChainBridge;
+
+impl MessageBridge for OnThisChainBridge {
+	const BRIDGED_MESSAGES_PALLET_NAME: &'static str = "";
+
+	type ThisChain = WrappedThisChain;
+	type BridgedChain = WrappedBridgedChain;
+	type BridgedHeaderChain = BridgedHeaderChain;
+}
+
+/// Run pallet test.
+pub fn run_test<T>(test: impl FnOnce() -> T) -> T {
+	sp_io::TestExternalities::new(
+		frame_system::GenesisConfig::<TestRuntime>::default().build_storage().unwrap(),
+	)
+	.execute_with(test)
+}

bridges/primitives/chain-kusama/src/lib.rs

@@ -52,8 +52,8 @@ impl ChainWithGrandpa for Kusama {
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = AVERAGE_HEADER_SIZE;
 }
 
 // The SignedExtension used by Kusama.

bridges/primitives/chain-polkadot-bulletin/src/lib.rs

@@ -42,8 +42,8 @@ use sp_runtime::{traits::DispatchInfoOf, transaction_validity::TransactionValidi
 // This chain reuses most of Polkadot primitives.
 pub use bp_polkadot_core::{
 	AccountAddress, AccountId, Balance, Block, BlockNumber, Hash, Hasher, Header, Nonce, Signature,
-	SignedBlock, UncheckedExtrinsic, AVERAGE_HEADER_SIZE_IN_JUSTIFICATION,
-	EXTRA_STORAGE_PROOF_SIZE, MAX_HEADER_SIZE, REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY,
+	SignedBlock, UncheckedExtrinsic, AVERAGE_HEADER_SIZE, EXTRA_STORAGE_PROOF_SIZE,
+	MAX_MANDATORY_HEADER_SIZE, REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY,
 };
 
 /// Maximal number of GRANDPA authorities at Polkadot Bulletin chain.
@@ -207,8 +207,8 @@ impl ChainWithGrandpa for PolkadotBulletin {
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = AVERAGE_HEADER_SIZE;
 }
 
 decl_bridge_finality_runtime_apis!(polkadot_bulletin, grandpa);

bridges/primitives/chain-polkadot/src/lib.rs

@@ -52,8 +52,8 @@ impl ChainWithGrandpa for Polkadot {
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = AVERAGE_HEADER_SIZE;
 }
 
 /// The SignedExtension used by Polkadot.

bridges/primitives/chain-rococo/src/lib.rs

@@ -52,8 +52,8 @@ impl ChainWithGrandpa for Rococo {
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = AVERAGE_HEADER_SIZE;
 }
 
 parameter_types! {

bridges/primitives/chain-westend/src/lib.rs

@@ -52,8 +52,8 @@ impl ChainWithGrandpa for Westend {
 	const MAX_AUTHORITIES_COUNT: u32 = MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 = MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = AVERAGE_HEADER_SIZE;
 }
 
 parameter_types! {

bridges/primitives/header-chain/src/justification/mod.rs

@@ -82,8 +82,8 @@ impl<H: HeaderT> GrandpaJustification<H> {
 			.saturating_add(BlockNumberOf::<C>::max_encoded_len().saturated_into())
 			.saturating_add(HashOf::<C>::max_encoded_len().saturated_into());
 
-		let max_expected_votes_ancestries_size = C::REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY
-			.saturating_mul(C::AVERAGE_HEADER_SIZE_IN_JUSTIFICATION);
+		let max_expected_votes_ancestries_size =
+			C::REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY.saturating_mul(C::AVERAGE_HEADER_SIZE);
 
 		// justification is round number (u64=8b), a signed GRANDPA commit and the
 		// `votes_ancestries` vector

bridges/primitives/header-chain/src/lib.rs

@@ -266,23 +266,28 @@ pub trait ChainWithGrandpa: Chain {
 	/// to submitter.
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32;
 
-	/// Maximal size of the chain header. The header may be the header that enacts new GRANDPA
-	/// authorities set (so it has large digest inside).
+	/// Maximal size of the mandatory chain header. Mandatory header is the header that enacts new
+	/// GRANDPA authorities set (so it has large digest inside).
 	///
 	/// This isn't a strict limit. The relay may submit larger headers and the pallet will accept
 	/// the call. The limit is only used to compute maximal refund amount and doing calls which
 	/// exceed the limit, may be costly to submitter.
-	const MAX_HEADER_SIZE: u32;
+	const MAX_MANDATORY_HEADER_SIZE: u32;
 
-	/// Average size of the chain header from justification ancestry. We don't expect to see there
-	/// headers that change GRANDPA authorities set (GRANDPA will probably be able to finalize at
-	/// least one additional header per session on non test chains), so this is average size of
-	/// headers that aren't changing the set.
+	/// Average size of the chain header. We don't expect to see there headers that change GRANDPA
+	/// authorities set (GRANDPA will probably be able to finalize at least one additional header
+	/// per session on non test chains), so this is average size of headers that aren't changing the
+	/// set.
 	///
-	/// This isn't a strict limit. The relay may submit justifications with larger headers in its
-	/// ancestry and the pallet will accept the call. The limit is only used to compute maximal
-	/// refund amount and doing calls which exceed the limit, may be costly to submitter.
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32;
+	/// This isn't a strict limit. The relay may submit justifications with larger headers and the
+	/// pallet will accept the call. However, if the total size of all `submit_finality_proof`
+	/// arguments exceeds the maximal size, computed using this average size, relayer will only get
+	/// partial refund.
+	///
+	/// We expect some headers on production chains that are above this size. But they are rare and
+	/// if rellayer cares about its profitability, we expect it'll select other headers for
+	/// submission.
+	const AVERAGE_HEADER_SIZE: u32;
 }
 
 impl<T> ChainWithGrandpa for T
@@ -295,7 +300,67 @@ where
 	const MAX_AUTHORITIES_COUNT: u32 = <T::Chain as ChainWithGrandpa>::MAX_AUTHORITIES_COUNT;
 	const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 =
 		<T::Chain as ChainWithGrandpa>::REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY;
-	const MAX_HEADER_SIZE: u32 = <T::Chain as ChainWithGrandpa>::MAX_HEADER_SIZE;
-	const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 =
-		<T::Chain as ChainWithGrandpa>::AVERAGE_HEADER_SIZE_IN_JUSTIFICATION;
+	const MAX_MANDATORY_HEADER_SIZE: u32 =
+		<T::Chain as ChainWithGrandpa>::MAX_MANDATORY_HEADER_SIZE;
+	const AVERAGE_HEADER_SIZE: u32 = <T::Chain as ChainWithGrandpa>::AVERAGE_HEADER_SIZE;
+}
+
+/// Returns maximal expected size of `submit_finality_proof` call arguments.
+pub fn max_expected_submit_finality_proof_arguments_size<C: ChainWithGrandpa>(
+	is_mandatory_finality_target: bool,
+	precommits: u32,
+) -> u32 {
+	let max_expected_justification_size =
+		GrandpaJustification::<HeaderOf<C>>::max_reasonable_size::<C>(precommits);
+
+	// call arguments are header and justification
+	let max_expected_finality_target_size = if is_mandatory_finality_target {
+		C::MAX_MANDATORY_HEADER_SIZE
+	} else {
+		C::AVERAGE_HEADER_SIZE
+	};
+	max_expected_finality_target_size.saturating_add(max_expected_justification_size)
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use frame_support::weights::Weight;
+	use sp_runtime::{testing::H256, traits::BlakeTwo256, MultiSignature};
+
+	struct TestChain;
+
+	impl Chain for TestChain {
+		type BlockNumber = u32;
+		type Hash = H256;
+		type Hasher = BlakeTwo256;
+		type Header = sp_runtime::generic::Header<u32, BlakeTwo256>;
+		type AccountId = u64;
+		type Balance = u64;
+		type Nonce = u64;
+		type Signature = MultiSignature;
+
+		fn max_extrinsic_size() -> u32 {
+			0
+		}
+		fn max_extrinsic_weight() -> Weight {
+			Weight::zero()
+		}
+	}
+
+	impl ChainWithGrandpa for TestChain {
+		const WITH_CHAIN_GRANDPA_PALLET_NAME: &'static str = "Test";
+		const MAX_AUTHORITIES_COUNT: u32 = 128;
+		const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 2;
+		const MAX_MANDATORY_HEADER_SIZE: u32 = 100_000;
+		const AVERAGE_HEADER_SIZE: u32 = 1_024;
+	}
+
+	#[test]
+	fn max_expected_submit_finality_proof_arguments_size_respects_mandatory_argument() {
+		assert!(
+			max_expected_submit_finality_proof_arguments_size::<TestChain>(true, 100) >
+				max_expected_submit_finality_proof_arguments_size::<TestChain>(false, 100),
+		);
+	}
 }

bridges/primitives/polkadot-core/src/lib.rs

@@ -64,30 +64,28 @@ pub const MAX_AUTHORITIES_COUNT: u32 = 1_256;
 ///
 /// See [`bp-header-chain::ChainWithGrandpa`] for more details.
 ///
-/// This value comes from recent (February, 2023) Kusama and Polkadot headers. There are no
+/// This value comes from recent (December, 2023) Kusama and Polkadot headers. There are no
 /// justifications with any additional headers in votes ancestry, so reasonable headers may
 /// be set to zero. But we assume that there may be small GRANDPA lags, so we're leaving some
 /// reserve here.
 pub const REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY: u32 = 2;
 
-/// Approximate average header size in `votes_ancestries` field of justification on Polkadot-like
+/// Average header size in `votes_ancestries` field of justification on Polkadot-like
 /// chains.
 ///
 /// See [`bp-header-chain::ChainWithGrandpa`] for more details.
 ///
-/// This value comes from recent (February, 2023) Kusama headers. Average is `336` there, but some
-/// non-mandatory headers has size `40kb` (they contain the BABE epoch descriptor with all
-/// authorities - just like our mandatory header). Since we assume `2` headers in justification
-/// votes ancestry, let's set average header to `40kb / 2`.
-pub const AVERAGE_HEADER_SIZE_IN_JUSTIFICATION: u32 = 20 * 1024;
+/// This value comes from recent (December, 2023) Kusama headers. Most of headers are `327` bytes
+/// there, but let's have some reserve and make it 1024.
+pub const AVERAGE_HEADER_SIZE: u32 = 1024;
 
 /// Approximate maximal header size on Polkadot-like chains.
 ///
 /// See [`bp-header-chain::ChainWithGrandpa`] for more details.
 ///
-/// This value comes from recent (February, 2023) Kusama headers. Maximal header is a mandatory
-/// header. In its SCALE-encoded form it is `80348` bytes. Let's have some reserve here.
-pub const MAX_HEADER_SIZE: u32 = 90_000;
+/// This value comes from recent (December, 2023) Kusama headers. Maximal header is a mandatory
+/// header. In its SCALE-encoded form it is `113407` bytes. Let's have some reserve here.
+pub const MAX_MANDATORY_HEADER_SIZE: u32 = 120 * 1024;
 
 /// Number of extra bytes (excluding size of storage value itself) of storage proof, built at
 /// Polkadot-like chain. This mostly depends on number of entries in the storage trie.

bridges/primitives/xcm-bridge-hub/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "bp-xcm-bridge-hub"
+description = "Primitives of the xcm-bridge-hub pallet."
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+
+[dependencies]
+
+# Substrate Dependencies
+sp-std = { path = "../../../substrate/primitives/std", default-features = false }
+
+[features]
+default = ["std"]
+std = ["sp-std/std"]

bridges/primitives/xcm-bridge-hub/src/lib.rs

@@ -0,0 +1,24 @@
+// 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/>.
+
+//! Primitives of the xcm-bridge-hub pallet.
+
+#![warn(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+/// Encoded XCM blob. We expect the bridge messages pallet to use this blob type for both inbound
+/// and outbound payloads.
+pub type XcmAsPlainPayload = sp_std::vec::Vec<u8>;

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

@@ -16,7 +16,7 @@
 use crate::*;
 
 #[test]
-fn send_xcm_from_rococo_relay_to_westend_asset_hub() {
+fn send_xcm_from_rococo_relay_to_westend_asset_hub_should_fail_on_not_applicable() {
 	// Init tests variables
 	// XcmPallet send arguments
 	let sudo_origin = <Rococo as Chain>::RuntimeOrigin::root();
@@ -53,7 +53,8 @@ fn send_xcm_from_rococo_relay_to_westend_asset_hub() {
 			]
 		);
 	});
-	// Receive XCM message in Bridge Hub source Parachain
+	// Receive XCM message in Bridge Hub source Parachain, it should fail, because we don't have
+	// opened bridge/lane.
 	BridgeHubRococo::execute_with(|| {
 		type RuntimeEvent = <BridgeHubRococo as Chain>::RuntimeEvent;
 
@@ -61,37 +62,7 @@ fn send_xcm_from_rococo_relay_to_westend_asset_hub() {
 			BridgeHubRococo,
 			vec![
 				RuntimeEvent::MessageQueue(pallet_message_queue::Event::Processed {
-					success: true,
-					..
-				}) => {},
-				RuntimeEvent::BridgeWestendMessages(pallet_bridge_messages::Event::MessageAccepted {
-					lane_id: LaneId([0, 0, 0, 2]),
-					nonce: 1,
-				}) => {},
-			]
-		);
-	});
-
-	// Westend Global Consensus
-	// Receive XCM message in Bridge Hub target Parachain
-	BridgeHubWestend::execute_with(|| {
-		type RuntimeEvent = <BridgeHubWestend as Chain>::RuntimeEvent;
-
-		assert_expected_events!(
-			BridgeHubWestend,
-			vec![
-				RuntimeEvent::XcmpQueue(cumulus_pallet_xcmp_queue::Event::XcmpMessageSent { .. }) => {},
-			]
-		);
-	});
-	// Receive embedded XCM message within `ExportMessage` in Parachain destination
-	AssetHubWestend::execute_with(|| {
-		type RuntimeEvent = <AssetHubWestend as Chain>::RuntimeEvent;
-
-		assert_expected_events!(
-			AssetHubWestend,
-			vec![
-				RuntimeEvent::MessageQueue(pallet_message_queue::Event::ProcessingFailed {
+					success: false,
 					..
 				}) => {},
 			]

cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-westend/src/tests/send_xcm.rs

@@ -16,7 +16,7 @@
 use crate::*;
 
 #[test]
-fn send_xcm_from_westend_relay_to_rococo_asset_hub() {
+fn send_xcm_from_westend_relay_to_rococo_asset_hub_should_fail_on_not_applicable() {
 	// Init tests variables
 	// XcmPallet send arguments
 	let sudo_origin = <Westend as Chain>::RuntimeOrigin::root();
@@ -53,7 +53,8 @@ fn send_xcm_from_westend_relay_to_rococo_asset_hub() {
 			]
 		);
 	});
-	// Receive XCM message in Bridge Hub source Parachain
+	// Receive XCM message in Bridge Hub source Parachain, it should fail, because we don't have
+	// opened bridge/lane.
 	BridgeHubWestend::execute_with(|| {
 		type RuntimeEvent = <BridgeHubWestend as Chain>::RuntimeEvent;
 
@@ -61,37 +62,7 @@ fn send_xcm_from_westend_relay_to_rococo_asset_hub() {
 			BridgeHubWestend,
 			vec![
 				RuntimeEvent::MessageQueue(pallet_message_queue::Event::Processed {
-					success: true,
-					..
-				}) => {},
-				RuntimeEvent::BridgeRococoMessages(pallet_bridge_messages::Event::MessageAccepted {
-					lane_id: LaneId([0, 0, 0, 2]),
-					nonce: 1,
-				}) => {},
-			]
-		);
-	});
-
-	// Rococo Global Consensus
-	// Receive XCM message in Bridge Hub target Parachain
-	BridgeHubRococo::execute_with(|| {
-		type RuntimeEvent = <BridgeHubRococo as Chain>::RuntimeEvent;
-
-		assert_expected_events!(
-			BridgeHubRococo,
-			vec![
-				RuntimeEvent::XcmpQueue(cumulus_pallet_xcmp_queue::Event::XcmpMessageSent { .. }) => {},
-			]
-		);
-	});
-	// Receive embedded XCM message within `ExportMessage` in Parachain destination
-	AssetHubRococo::execute_with(|| {
-		type RuntimeEvent = <AssetHubRococo as Chain>::RuntimeEvent;
-
-		assert_expected_events!(
-			AssetHubRococo,
-			vec![
-				RuntimeEvent::MessageQueue(pallet_message_queue::Event::ProcessingFailed {
+					success: false,
 					..
 				}) => {},
 			]

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/Cargo.toml

@@ -98,6 +98,7 @@ pallet-bridge-grandpa = { path = "../../../../../bridges/modules/grandpa", defau
 pallet-bridge-messages = { path = "../../../../../bridges/modules/messages", default-features = false }
 pallet-bridge-parachains = { path = "../../../../../bridges/modules/parachains", default-features = false }
 pallet-bridge-relayers = { path = "../../../../../bridges/modules/relayers", default-features = false }
+pallet-xcm-bridge-hub = { path = "../../../../../bridges/modules/xcm-bridge-hub", default-features = false }
 bridge-runtime-common = { path = "../../../../../bridges/bin/runtime-common", default-features = false }
 
 [dev-dependencies]
@@ -156,6 +157,7 @@ std = [
 	"pallet-transaction-payment/std",
 	"pallet-utility/std",
 	"pallet-xcm-benchmarks?/std",
+	"pallet-xcm-bridge-hub/std",
 	"pallet-xcm/std",
 	"parachain-info/std",
 	"parachains-common/std",
@@ -207,6 +209,7 @@ runtime-benchmarks = [
 	"pallet-timestamp/runtime-benchmarks",
 	"pallet-utility/runtime-benchmarks",
 	"pallet-xcm-benchmarks/runtime-benchmarks",
+	"pallet-xcm-bridge-hub/runtime-benchmarks",
 	"pallet-xcm/runtime-benchmarks",
 	"parachains-common/runtime-benchmarks",
 	"polkadot-parachain-primitives/runtime-benchmarks",
@@ -239,6 +242,7 @@ try-runtime = [
 	"pallet-timestamp/try-runtime",
 	"pallet-transaction-payment/try-runtime",
 	"pallet-utility/try-runtime",
+	"pallet-xcm-bridge-hub/try-runtime",
 	"pallet-xcm/try-runtime",
 	"parachain-info/try-runtime",
 	"polkadot-runtime-common/try-runtime",

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/bridge_to_westend_config.rs

@@ -18,8 +18,10 @@
 
 use crate::{
 	bridge_common_config::{BridgeParachainWestendInstance, DeliveryRewardInBalance},
-	weights, AccountId, BridgeWestendMessages, ParachainInfo, Runtime, RuntimeEvent, RuntimeOrigin,
-	XcmRouter,
+	weights,
+	xcm_config::UniversalLocation,
+	AccountId, BridgeWestendMessages, Runtime, RuntimeEvent, RuntimeOrigin,
+	XcmOverBridgeHubWestend, XcmRouter,
 };
 use bp_messages::LaneId;
 use bridge_runtime_common::{
@@ -46,7 +48,7 @@ use xcm::{
 	latest::prelude::*,
 	prelude::{InteriorMultiLocation, NetworkId},
 };
-use xcm_builder::{BridgeBlobDispatcher, HaulBlobExporter};
+use xcm_builder::BridgeBlobDispatcher;
 
 parameter_types! {
 	pub const MaxUnrewardedRelayerEntriesAtInboundLane: bp_messages::MessageNonce =
@@ -55,23 +57,28 @@ parameter_types! {
 		bp_bridge_hub_rococo::MAX_UNCONFIRMED_MESSAGES_IN_CONFIRMATION_TX;
 	pub const BridgeHubWestendChainId: bp_runtime::ChainId = bp_runtime::BRIDGE_HUB_WESTEND_CHAIN_ID;
 	pub BridgeRococoToWestendMessagesPalletInstance: InteriorMultiLocation = X1(PalletInstance(<BridgeWestendMessages as PalletInfoAccess>::index() as u8));
-	pub BridgeHubRococoUniversalLocation: InteriorMultiLocation = X2(GlobalConsensus(Rococo), Parachain(ParachainInfo::parachain_id().into()));
 	pub WestendGlobalConsensusNetwork: NetworkId = NetworkId::Westend;
-	pub ActiveOutboundLanesToBridgeHubWestend: &'static [bp_messages::LaneId] = &[XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND];
-	pub const AssetHubRococoToAssetHubWestendMessagesLane: bp_messages::LaneId = XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND;
 	// see the `FEE_BOOST_PER_MESSAGE` constant to get the meaning of this value
 	pub PriorityBoostPerMessage: u64 = 182_044_444_444_444;
 
 	pub AssetHubRococoParaId: cumulus_primitives_core::ParaId = bp_asset_hub_rococo::ASSET_HUB_ROCOCO_PARACHAIN_ID.into();
 	pub AssetHubWestendParaId: cumulus_primitives_core::ParaId = bp_asset_hub_westend::ASSET_HUB_WESTEND_PARACHAIN_ID.into();
 
+	// Lanes
+	pub ActiveOutboundLanesToBridgeHubWestend: &'static [bp_messages::LaneId] = &[XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND];
+	pub const AssetHubRococoToAssetHubWestendMessagesLane: bp_messages::LaneId = XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND;
 	pub FromAssetHubRococoToAssetHubWestendRoute: SenderAndLane = SenderAndLane::new(
 		ParentThen(X1(Parachain(AssetHubRococoParaId::get().into()))).into(),
 		XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND,
 	);
+	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+			(
+				FromAssetHubRococoToAssetHubWestendRoute::get(),
+				(WestendGlobalConsensusNetwork::get(), X1(Parachain(AssetHubWestendParaId::get().into())))
+			)
+	];
 
 	pub CongestedMessage: Xcm<()> = build_congestion_message(true).into();
-
 	pub UncongestedMessage: Xcm<()> = build_congestion_message(false).into();
 }
 pub const XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND: LaneId = LaneId([0, 0, 0, 2]);
@@ -103,23 +110,16 @@ pub type ToWestendBridgeHubMessagesDeliveryProof =
 	FromBridgedChainMessagesDeliveryProof<bp_bridge_hub_westend::Hash>;
 
 /// Dispatches received XCM messages from other bridge
-type FromWestendMessageBlobDispatcher = BridgeBlobDispatcher<
-	XcmRouter,
-	BridgeHubRococoUniversalLocation,
-	BridgeRococoToWestendMessagesPalletInstance,
->;
+type FromWestendMessageBlobDispatcher =
+	BridgeBlobDispatcher<XcmRouter, UniversalLocation, BridgeRococoToWestendMessagesPalletInstance>;
 
 /// Export XCM messages to be relayed to the other side
-pub type ToBridgeHubWestendHaulBlobExporter = HaulBlobExporter<
-	XcmBlobHaulerAdapter<ToBridgeHubWestendXcmBlobHauler>,
-	WestendGlobalConsensusNetwork,
-	(),
->;
+pub type ToBridgeHubWestendHaulBlobExporter = XcmOverBridgeHubWestend;
+
 pub struct ToBridgeHubWestendXcmBlobHauler;
 impl XcmBlobHauler for ToBridgeHubWestendXcmBlobHauler {
 	type Runtime = Runtime;
 	type MessagesInstance = WithBridgeHubWestendMessagesInstance;
-	type SenderAndLane = FromAssetHubRococoToAssetHubWestendRoute;
 
 	type ToSourceChainSender = XcmRouter;
 	type CongestedMessage = CongestedMessage;
@@ -127,7 +127,8 @@ impl XcmBlobHauler for ToBridgeHubWestendXcmBlobHauler {
 }
 
 /// On messages delivered callback.
-type OnMessagesDeliveredFromWestend = XcmBlobHaulerAdapter<ToBridgeHubWestendXcmBlobHauler>;
+type OnMessagesDeliveredFromWestend =
+	XcmBlobHaulerAdapter<ToBridgeHubWestendXcmBlobHauler, ActiveLanes>;
 
 /// Messaging Bridge configuration for BridgeHubRococo -> BridgeHubWestend
 pub struct WithBridgeHubWestendMessageBridge;
@@ -229,6 +230,17 @@ impl pallet_bridge_messages::Config<WithBridgeHubWestendMessagesInstance> for Ru
 	type OnMessagesDelivered = OnMessagesDeliveredFromWestend;
 }
 
+/// Add support for the export and dispatch of XCM programs.
+pub type XcmOverBridgeHubWestendInstance = pallet_xcm_bridge_hub::Instance1;
+impl pallet_xcm_bridge_hub::Config<XcmOverBridgeHubWestendInstance> for Runtime {
+	type UniversalLocation = UniversalLocation;
+	type BridgedNetworkId = WestendGlobalConsensusNetwork;
+	type BridgeMessagesPalletInstance = WithBridgeHubWestendMessagesInstance;
+	type MessageExportPrice = ();
+	type Lanes = ActiveLanes;
+	type LanesSupport = ToBridgeHubWestendXcmBlobHauler;
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs

@@ -500,6 +500,8 @@ construct_runtime!(
 
 		BridgeRelayers: pallet_bridge_relayers::{Pallet, Call, Storage, Event<T>} = 47,
 
+		XcmOverBridgeHubWestend: pallet_xcm_bridge_hub::<Instance1>::{Pallet} = 52,
+
 		// Message Queue. Importantly, is registered last so that messages are processed after
 		// the `on_initialize` hooks of bridging pallets.
 		MessageQueue: pallet_message_queue::{Pallet, Call, Storage, Event<T>} = 250,
@@ -931,7 +933,13 @@ impl_runtime_apis! {
 
 				fn export_message_origin_and_destination(
 				) -> Result<(MultiLocation, NetworkId, InteriorMultiLocation), BenchmarkError> {
-					Ok((TokenLocation::get(), NetworkId::Westend, X1(Parachain(100))))
+					Ok(
+						(
+							bridge_to_westend_config::FromAssetHubRococoToAssetHubWestendRoute::get().location,
+							NetworkId::Westend,
+							X1(Parachain(bridge_to_westend_config::AssetHubWestendParaId::get().into()))
+						)
+					)
 				}
 
 				fn alias_origin() -> Result<(MultiLocation, MultiLocation), BenchmarkError> {

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/tests/tests.rs

@@ -191,7 +191,7 @@ mod bridge_hub_rococo_tests {
 					_ => None,
 				}
 			}),
-			|| ExportMessage { network: Westend, destination: X1(Parachain(1234)), xcm: Xcm(vec![]) },
+			|| ExportMessage { network: Westend, destination: X1(Parachain(bridge_to_westend_config::AssetHubWestendParaId::get().into())), xcm: Xcm(vec![]) },
 			XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND,
 			Some((TokenLocation::get(), ExistentialDeposit::get()).into()),
 			// value should be >= than value generated by `can_calculate_weight_for_paid_export_message_with_reserve_transfer`

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/Cargo.toml

@@ -74,6 +74,7 @@ parachain-info = { package = "staging-parachain-info", path = "../../../pallets/
 parachains-common = { path = "../../../common", default-features = false }
 
 # Bridges
+bp-asset-hub-rococo = { path = "../../../../../bridges/primitives/chain-asset-hub-rococo", default-features = false }
 bp-asset-hub-westend = { path = "../../../../../bridges/primitives/chain-asset-hub-westend", default-features = false }
 bp-bridge-hub-rococo = { path = "../../../../../bridges/primitives/chain-bridge-hub-rococo", default-features = false }
 bp-bridge-hub-westend = { path = "../../../../../bridges/primitives/chain-bridge-hub-westend", default-features = false }
@@ -89,6 +90,7 @@ pallet-bridge-grandpa = { path = "../../../../../bridges/modules/grandpa", defau
 pallet-bridge-messages = { path = "../../../../../bridges/modules/messages", default-features = false }
 pallet-bridge-parachains = { path = "../../../../../bridges/modules/parachains", default-features = false }
 pallet-bridge-relayers = { path = "../../../../../bridges/modules/relayers", default-features = false }
+pallet-xcm-bridge-hub = { path = "../../../../../bridges/modules/xcm-bridge-hub", default-features = false }
 bridge-runtime-common = { path = "../../../../../bridges/bin/runtime-common", default-features = false }
 
 [dev-dependencies]
@@ -100,6 +102,7 @@ sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
 [features]
 default = ["std"]
 std = [
+	"bp-asset-hub-rococo/std",
 	"bp-asset-hub-westend/std",
 	"bp-bridge-hub-rococo/std",
 	"bp-bridge-hub-westend/std",
@@ -144,6 +147,7 @@ std = [
 	"pallet-transaction-payment/std",
 	"pallet-utility/std",
 	"pallet-xcm-benchmarks?/std",
+	"pallet-xcm-bridge-hub/std",
 	"pallet-xcm/std",
 	"parachain-info/std",
 	"parachains-common/std",
@@ -195,6 +199,7 @@ runtime-benchmarks = [
 	"pallet-timestamp/runtime-benchmarks",
 	"pallet-utility/runtime-benchmarks",
 	"pallet-xcm-benchmarks/runtime-benchmarks",
+	"pallet-xcm-bridge-hub/runtime-benchmarks",
 	"pallet-xcm/runtime-benchmarks",
 	"parachains-common/runtime-benchmarks",
 	"polkadot-parachain-primitives/runtime-benchmarks",
@@ -227,6 +232,7 @@ try-runtime = [
 	"pallet-timestamp/try-runtime",
 	"pallet-transaction-payment/try-runtime",
 	"pallet-utility/try-runtime",
+	"pallet-xcm-bridge-hub/try-runtime",
 	"pallet-xcm/try-runtime",
 	"parachain-info/try-runtime",
 	"polkadot-runtime-common/try-runtime",

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/bridge_to_rococo_config.rs

@@ -17,8 +17,9 @@
 //! Bridge definitions used on BridgeHub with the Westend flavor.
 
 use crate::{
-	bridge_common_config::DeliveryRewardInBalance, weights, AccountId, BridgeRococoMessages,
-	ParachainInfo, Runtime, RuntimeEvent, RuntimeOrigin, XcmRouter,
+	bridge_common_config::DeliveryRewardInBalance, weights, xcm_config::UniversalLocation,
+	AccountId, BridgeRococoMessages, Runtime, RuntimeEvent, RuntimeOrigin, XcmOverBridgeHubRococo,
+	XcmRouter,
 };
 use bp_messages::LaneId;
 use bp_parachains::SingleParaStoredHeaderDataBuilder;
@@ -48,7 +49,7 @@ use xcm::{
 	latest::prelude::*,
 	prelude::{InteriorMultiLocation, NetworkId},
 };
-use xcm_builder::{BridgeBlobDispatcher, HaulBlobExporter};
+use xcm_builder::BridgeBlobDispatcher;
 
 parameter_types! {
 	pub const RelayChainHeadersToKeep: u32 = 1024;
@@ -62,23 +63,29 @@ parameter_types! {
 	pub const MaxUnconfirmedMessagesAtInboundLane: bp_messages::MessageNonce =
 		bp_bridge_hub_westend::MAX_UNCONFIRMED_MESSAGES_IN_CONFIRMATION_TX;
 	pub const BridgeHubRococoChainId: bp_runtime::ChainId = bp_runtime::BRIDGE_HUB_ROCOCO_CHAIN_ID;
-	pub BridgeHubWestendUniversalLocation: InteriorMultiLocation = X2(GlobalConsensus(Westend), Parachain(ParachainInfo::parachain_id().into()));
 	pub BridgeWestendToRococoMessagesPalletInstance: InteriorMultiLocation = X1(PalletInstance(<BridgeRococoMessages as PalletInfoAccess>::index() as u8));
 	pub RococoGlobalConsensusNetwork: NetworkId = NetworkId::Rococo;
-	pub ActiveOutboundLanesToBridgeHubRococo: &'static [bp_messages::LaneId] = &[XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO];
-	pub const AssetHubWestendToAssetHubRococoMessagesLane: bp_messages::LaneId = XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO;
 	// see the `FEE_BOOST_PER_MESSAGE` constant to get the meaning of this value
 	pub PriorityBoostPerMessage: u64 = 182_044_444_444_444;
 
 	pub AssetHubWestendParaId: cumulus_primitives_core::ParaId = bp_asset_hub_westend::ASSET_HUB_WESTEND_PARACHAIN_ID.into();
+	pub AssetHubRococoParaId: cumulus_primitives_core::ParaId = bp_asset_hub_rococo::ASSET_HUB_ROCOCO_PARACHAIN_ID.into();
 
+	// Lanes
+	pub ActiveOutboundLanesToBridgeHubRococo: &'static [bp_messages::LaneId] = &[XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO];
+	pub const AssetHubWestendToAssetHubRococoMessagesLane: bp_messages::LaneId = XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO;
 	pub FromAssetHubWestendToAssetHubRococoRoute: SenderAndLane = SenderAndLane::new(
 		ParentThen(X1(Parachain(AssetHubWestendParaId::get().into()))).into(),
 		XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO,
 	);
+	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+			(
+				FromAssetHubWestendToAssetHubRococoRoute::get(),
+				(RococoGlobalConsensusNetwork::get(), X1(Parachain(AssetHubRococoParaId::get().into())))
+			)
+	];
 
 	pub CongestedMessage: Xcm<()> = build_congestion_message(true).into();
-
 	pub UncongestedMessage: Xcm<()> = build_congestion_message(false).into();
 }
 pub const XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO: LaneId = LaneId([0, 0, 0, 2]);
@@ -110,23 +117,16 @@ pub type ToRococoBridgeHubMessagesDeliveryProof =
 	FromBridgedChainMessagesDeliveryProof<bp_bridge_hub_rococo::Hash>;
 
 /// Dispatches received XCM messages from other bridge
-type FromRococoMessageBlobDispatcher = BridgeBlobDispatcher<
-	XcmRouter,
-	BridgeHubWestendUniversalLocation,
-	BridgeWestendToRococoMessagesPalletInstance,
->;
+type FromRococoMessageBlobDispatcher =
+	BridgeBlobDispatcher<XcmRouter, UniversalLocation, BridgeWestendToRococoMessagesPalletInstance>;
 
 /// Export XCM messages to be relayed to the other side
-pub type ToBridgeHubRococoHaulBlobExporter = HaulBlobExporter<
-	XcmBlobHaulerAdapter<ToBridgeHubRococoXcmBlobHauler>,
-	RococoGlobalConsensusNetwork,
-	(),
->;
+pub type ToBridgeHubRococoHaulBlobExporter = XcmOverBridgeHubRococo;
+
 pub struct ToBridgeHubRococoXcmBlobHauler;
 impl XcmBlobHauler for ToBridgeHubRococoXcmBlobHauler {
 	type Runtime = Runtime;
 	type MessagesInstance = WithBridgeHubRococoMessagesInstance;
-	type SenderAndLane = FromAssetHubWestendToAssetHubRococoRoute;
 
 	type ToSourceChainSender = XcmRouter;
 	type CongestedMessage = CongestedMessage;
@@ -134,7 +134,7 @@ impl XcmBlobHauler for ToBridgeHubRococoXcmBlobHauler {
 }
 
 /// On messages delivered callback.
-type OnMessagesDelivered = XcmBlobHaulerAdapter<ToBridgeHubRococoXcmBlobHauler>;
+type OnMessagesDelivered = XcmBlobHaulerAdapter<ToBridgeHubRococoXcmBlobHauler, ActiveLanes>;
 
 /// Messaging Bridge configuration for BridgeHubWestend -> BridgeHubRococo
 pub struct WithBridgeHubRococoMessageBridge;
@@ -256,6 +256,17 @@ impl pallet_bridge_messages::Config<WithBridgeHubRococoMessagesInstance> for Run
 	type OnMessagesDelivered = OnMessagesDelivered;
 }
 
+/// Add support for the export and dispatch of XCM programs.
+pub type XcmOverBridgeHubRococoInstance = pallet_xcm_bridge_hub::Instance1;
+impl pallet_xcm_bridge_hub::Config<XcmOverBridgeHubRococoInstance> for Runtime {
+	type UniversalLocation = UniversalLocation;
+	type BridgedNetworkId = RococoGlobalConsensusNetwork;
+	type BridgeMessagesPalletInstance = WithBridgeHubRococoMessagesInstance;
+	type MessageExportPrice = ();
+	type Lanes = ActiveLanes;
+	type LanesSupport = ToBridgeHubRococoXcmBlobHauler;
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs

@@ -488,6 +488,7 @@ construct_runtime!(
 		BridgeRococoGrandpa: pallet_bridge_grandpa::<Instance1>::{Pallet, Call, Storage, Event<T>, Config<T>} = 42,
 		BridgeRococoParachains: pallet_bridge_parachains::<Instance1>::{Pallet, Call, Storage, Event<T>} = 43,
 		BridgeRococoMessages: pallet_bridge_messages::<Instance1>::{Pallet, Call, Storage, Event<T>, Config<T>} = 44,
+		XcmOverBridgeHubRococo: pallet_xcm_bridge_hub::<Instance1>::{Pallet} = 45,
 
 		// Message Queue. Importantly, is registered last so that messages are processed after
 		// the `on_initialize` hooks of bridging pallets.
@@ -921,7 +922,13 @@ impl_runtime_apis! {
 
 				fn export_message_origin_and_destination(
 				) -> Result<(MultiLocation, NetworkId, InteriorMultiLocation), BenchmarkError> {
-					Ok((WestendLocation::get(), NetworkId::Rococo, X1(Parachain(100))))
+					Ok(
+						(
+							bridge_to_rococo_config::FromAssetHubWestendToAssetHubRococoRoute::get().location,
+							NetworkId::Rococo,
+							X1(Parachain(bridge_to_rococo_config::AssetHubRococoParaId::get().into()))
+						)
+					)
 				}
 
 				fn alias_origin() -> Result<(MultiLocation, MultiLocation), BenchmarkError> {

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/tests/tests.rs

@@ -179,7 +179,7 @@ fn handle_export_message_from_system_parachain_add_to_outbound_queue_works() {
 					_ => None,
 				}
 			}),
-			|| ExportMessage { network: Rococo, destination: X1(Parachain(4321)), xcm: Xcm(vec![]) },
+			|| ExportMessage { network: Rococo, destination: X1(Parachain(bridge_to_rococo_config::AssetHubRococoParaId::get().into())), xcm: Xcm(vec![]) },
 			XCM_LANE_FOR_ASSET_HUB_WESTEND_TO_ASSET_HUB_ROCOCO,
 			Some((WestendLocation::get(), ExistentialDeposit::get()).into()),
 			// value should be >= than value generated by `can_calculate_weight_for_paid_export_message_with_reserve_transfer`

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases.rs

@@ -1457,9 +1457,9 @@ pub mod test_data {
 			);
 		// to compute proper cost of GRANDPA call, let's add some dummy bytes to header, so that the
 		// `submit_finality_proof` call size would be close to maximal expected (and refundable)
-		let expected_bytes_in_grandpa_call = BridgedRelayChain::AVERAGE_HEADER_SIZE_IN_JUSTIFICATION
+		let expected_bytes_in_grandpa_call = BridgedRelayChain::AVERAGE_HEADER_SIZE
 			.saturating_mul(BridgedRelayChain::REASONABLE_HEADERS_IN_JUSTIFICATON_ANCESTRY)
-			.saturating_add(BridgedRelayChain::MAX_HEADER_SIZE)
+			.saturating_add(BridgedRelayChain::MAX_MANDATORY_HEADER_SIZE)
 			as usize;
 		let extra_bytes_required =
 			expected_bytes_in_grandpa_call.saturating_sub(relay_chain_header.encoded_size());