Allow withdrawing xcm gateway protocol fees (#623)

Author: Wizdave97

modules/ismp/clients/parachain/client/src/consensus.rs

@@ -56,7 +56,7 @@ pub const PASSET_HUB_TESTNET_CHAIN_ID: u32 = 420420422;
 pub const ASSET_HUB_MAINNET_PARA_ID: u32 = 1000;
 
 /// AssetHub mainnet EVM chain ID (TBD)
-pub const ASSET_HUB_MAINNET_CHAIN_ID: u32 = 1000;
+pub const ASSET_HUB_MAINNET_CHAIN_ID: u32 = 420420419;
 
 /// The state machine provider that resolves to a `StateMachineClient`
 pub trait ParachainStateMachineProvider<T> {

modules/ismp/core/src/host.rs

@@ -25,7 +25,11 @@ use crate::{
 	prelude::Vec,
 	router::{IsmpRouter, PostResponse, Request, Response},
 };
-use alloc::{boxed::Box, format, string::String};
+use alloc::{
+	boxed::Box,
+	format,
+	string::{String, ToString},
+};
 use codec::{Decode, DecodeWithMemTracking, Encode};
 use core::{fmt::Display, str::FromStr, time::Duration};
 use primitive_types::H256;
@@ -312,19 +316,23 @@ impl Display for StateMachine {
 			},
 			StateMachine::Polkadot(id) => format!("POLKADOT-{id}"),
 			StateMachine::Kusama(id) => format!("KUSAMA-{id}"),
+			// Invalid byte sequence will result in a default state machine id rendering the request
+			// invalid and undeliverable
 			StateMachine::Substrate(id) => {
 				format!(
 					"SUBSTRATE-{}",
-					String::from_utf8(id.to_vec()).map_err(|_| core::fmt::Error)?
+					String::from_utf8(id.to_vec()).unwrap_or("XXXX".to_string())
 				)
 			},
-			StateMachine::Tendermint(id) => format!(
-				"TNDRMINT-{}",
-				String::from_utf8(id.to_vec()).map_err(|_| core::fmt::Error)?
-			),
+			// Invalid byte sequence will result in a default state machine id rendering the request
+			// invalid and undeliverable
+			StateMachine::Tendermint(id) =>
+				format!("TNDRMINT-{}", String::from_utf8(id.to_vec()).unwrap_or("XXXX".to_string())),
+			// Invalid byte sequence will result in a default state machine id rendering the request
+			// invalid and undeliverable
 			StateMachine::Relay { relay, para_id } => format!(
 				"RELAY-{}-{para_id}",
-				String::from_utf8(relay.to_vec()).map_err(|_| core::fmt::Error)?
+				String::from_utf8(relay.to_vec()).unwrap_or("XXXX".to_string())
 			),
 		};
 		write!(f, "{}", str)
@@ -430,4 +438,22 @@ mod tests {
 		assert_eq!(beefy, StateMachine::from_str(&beefy_string).unwrap());
 		assert_eq!(solo_relay, StateMachine::from_str(&solo_string).unwrap());
 	}
+
+	#[test]
+	fn invalid_state_machine_conversions() {
+		let grandpa = StateMachine::Substrate(*b"\xf0\x28\x8c\xbc");
+		let beefy = StateMachine::Tendermint(*b"\xf0\x28\x8c\xbc");
+		let solo_relay = StateMachine::Relay { relay: *b"\xf0\x28\x8c\xbc", para_id: 1000 };
+
+		let grandpa_string = grandpa.to_string();
+		let beefy_string = beefy.to_string();
+		let solo_string = solo_relay.to_string();
+		dbg!(&grandpa_string);
+		dbg!(&beefy_string);
+		dbg!(&solo_string);
+
+		assert_eq!(grandpa_string, "SUBSTRATE-XXXX".to_string());
+		assert_eq!(beefy_string, "TNDRMINT-XXXX".to_string());
+		assert_eq!(solo_string, "RELAY-XXXX-1000".to_string());
+	}
 }

modules/pallets/testsuite/src/tests/pallet_xcm_gateway.rs

@@ -22,10 +22,8 @@ use pallet_xcm_gateway::Module;
 use polkadot_sdk::{
 	sp_runtime::traits::AccountIdConversion,
 	xcm_simulator::{
-		All, AllCounted, Asset, AssetFilter, AssetId, BuyExecution, DepositAsset, Fungibility,
-		GeneralIndex, Here, InitiateTransfer, PalletInstance, ParaId, Parachain, Parent,
-		Reanchorable, SetFeesMode, TransferAsset, TransferReserveAsset, VersionedXcm, Weight, Wild,
-		Xcm,
+		All, Asset, AssetId, BuyExecution, DepositAsset, Fungibility, Here, ParaId, Parachain,
+		SetFeesMode, TransferReserveAsset, VersionedXcm, Weight, Wild, Xcm,
 	},
 };
 use sp_core::{ByteArray, H160, H256};
@@ -46,7 +44,6 @@ fn reserve_transfer_on_ah() {
 		Junction::GeneralIndex(1),
 	]))
 	.into_location();
-	let weight_limit = WeightLimit::Unlimited;
 
 	let asset_location_on_assethub = Location::new(1, Here);
 
@@ -83,8 +80,6 @@ fn should_dispatch_ismp_request_when_assets_are_received_from_assethub() {
 	let asset_id_on_paraa: H256 =
 		sp_io::hashing::keccak_256(&Location::new(1, Here).encode()).into();
 
-	let asset_location_on_assethub = Location::new(1, Here);
-
 	reserve_transfer_on_ah();
 
 	ParaA::execute_with(|| {
@@ -119,18 +114,6 @@ fn should_dispatch_ismp_request_when_assets_are_received_from_assethub() {
 fn should_process_on_accept_module_callback_correctly() {
 	MockNet::reset();
 
-	let beneficiary: Location = Junctions::X4(Arc::new([
-		Junction::AccountId32 { network: None, id: ALICE.into() },
-		Junction::AccountKey20 {
-			network: Some(NetworkId::Ethereum { chain_id: 97 }),
-			key: [1u8; 20],
-		},
-		Junction::GeneralIndex(60 * 60),
-		Junction::GeneralIndex(1),
-	]))
-	.into_location();
-	let weight_limit = WeightLimit::Unlimited;
-
 	let asset_id: H256 = sp_io::hashing::keccak_256(&Location::new(1, Here).encode()).into();
 
 	reserve_transfer_on_ah();
@@ -224,18 +207,6 @@ fn should_process_on_timeout_module_callback_correctly() {
 
 	let asset_id: H256 = sp_io::hashing::keccak_256(&Location::new(1, Here).encode()).into();
 
-	let beneficiary: Location = Junctions::X4(Arc::new([
-		Junction::AccountId32 { network: None, id: ALICE.into() },
-		Junction::AccountKey20 {
-			network: Some(NetworkId::Ethereum { chain_id: 97 }),
-			key: [0u8; 20],
-		},
-		Junction::GeneralIndex(60 * 60),
-		Junction::GeneralIndex(1),
-	]))
-	.into_location();
-	let weight_limit = WeightLimit::Unlimited;
-
 	reserve_transfer_on_ah();
 
 	let alice_balance = ParaB::execute_with(|| {
@@ -321,3 +292,41 @@ fn should_process_on_timeout_module_callback_correctly() {
 		assert_eq!(current_balance, alice_balance + transferred);
 	})
 }
+
+#[test]
+fn should_withdraw_protocol_fees_successfully() {
+	MockNet::reset();
+
+	let asset_id: H256 = sp_io::hashing::keccak_256(&Location::new(1, Here).encode()).into();
+
+	// First, trigger a reserve transfer to accumulate protocol fees
+	reserve_transfer_on_ah();
+
+	ParaA::execute_with(|| {
+		let protocol_account = pallet_xcm_gateway::Pallet::<Test>::protocol_account_id();
+
+		// Verify protocol fees have accumulated
+		let protocol_balance_before = <runtime::Assets as Inspect<
+			<Test as frame_system::Config>::AccountId,
+		>>::balance(asset_id, &protocol_account);
+
+		let protocol_fee_percentage = pallet_xcm_gateway::Pallet::<Test>::protocol_fee_percentage();
+		let expected_protocol_fees = protocol_fee_percentage * SEND_AMOUNT;
+
+		assert_eq!(protocol_balance_before, expected_protocol_fees);
+		assert!(protocol_balance_before > 0, "Protocol fees should have accumulated");
+
+		// Withdraw protocol fees to BOB as beneficiary
+		assert_ok!(pallet_xcm_gateway::Pallet::<Test>::withdraw_protocol_fees(
+			frame_system::RawOrigin::Root.into(),
+			BOB
+		));
+
+		// Verify protocol account balance is now zero (all fees withdrawn)
+		let protocol_balance_after = <runtime::Assets as Inspect<
+			<Test as frame_system::Config>::AccountId,
+		>>::balance(asset_id, &protocol_account);
+
+		assert_eq!(protocol_balance_after, 0, "Protocol account should be empty after withdrawal");
+	});
+}

modules/pallets/xcm-gateway/Cargo.toml

@@ -36,6 +36,7 @@ features = [
     "staging-xcm",
     "staging-xcm-builder",
     "staging-xcm-executor",
+    "cumulus-primitives-core"
 ]
 
 [features]

modules/pallets/xcm-gateway/src/lib.rs

@@ -123,13 +123,15 @@ pub mod pallet {
 		DispatchPostError,
 		/// Pallet has not been initialized
 		NotInitialized,
+		/// No protocol fees
+		ProtocolFeeBalanceExhausted,
 	}
 
 	/// Events emiited by the relayer pallet
 	#[pallet::event]
 	#[pallet::generate_deposit(pub(super) fn deposit_event)]
 	pub enum Event<T: Config> {
-		/// An XCM transfer from the relay chain has been transformed into a crosschain message
+		/// An XCM transfer from  assethub has been transformed into a crosschain message
 		AssetTeleported {
 			/// Source account on the relaychain
 			from: T::AccountId,
@@ -148,7 +150,7 @@ pub mod pallet {
 		/// An asset has been received and transferred to the beneficiary's account on the
 		/// relaychain
 		AssetReceived {
-			/// beneficiary account on relaychain
+			/// beneficiary account on assethub
 			beneficiary: T::AccountId,
 			/// Amount transferred
 			amount: <T::Assets as fungibles::Inspect<T::AccountId>>::Balance,
@@ -159,13 +161,21 @@ pub mod pallet {
 		/// An asset has been refunded and transferred to the beneficiary's account on the
 		/// relaychain
 		AssetRefunded {
-			/// beneficiary account on relaychain
+			/// beneficiary account on assethub
 			beneficiary: T::AccountId,
 			/// Amount transferred
 			amount: <T::Assets as fungibles::Inspect<T::AccountId>>::Balance,
 			/// Destination chain
 			source: StateMachine,
 		},
+
+		/// Protocol Fees have been withdrawn to an account on assethub
+		ProtocolFeesWithdrawn {
+			/// beneficiary account on assethub
+			beneficiary: T::AccountId,
+			/// Amount transferred
+			amount: <T::Assets as fungibles::Inspect<T::AccountId>>::Balance,
+		},
 	}
 
 	#[derive(
@@ -207,6 +217,9 @@ pub mod pallet {
 	impl<T: Config> Pallet<T>
 	where
 		T::AccountId: From<[u8; 32]>,
+		T::AccountId: Into<[u8; 32]>,
+		u128: From<<T::Assets as fungibles::Inspect<T::AccountId>>::Balance>,
+		<T::Assets as fungibles::Inspect<T::AccountId>>::AssetId: From<[u8; 32]>,
 	{
 		#[pallet::weight(T::DbWeight::get().writes(1))]
 		#[pallet::call_index(0)]
@@ -224,6 +237,58 @@ pub mod pallet {
 			Params::<T>::put(current_params);
 			Ok(())
 		}
+
+		#[pallet::weight(T::DbWeight::get().writes(1))]
+		#[pallet::call_index(1)]
+		pub fn withdraw_protocol_fees(
+			origin: OriginFor<T>,
+			beneficiary: T::AccountId,
+		) -> DispatchResult {
+			T::GatewayOrigin::ensure_origin(origin)?;
+			let asset_id = Location::parent();
+
+			let local_asset_id = sp_io::hashing::keccak_256(&asset_id.encode());
+			let balance = <<T as Config>::Assets as fungibles::Inspect<T::AccountId>>::balance(
+				local_asset_id.into(),
+				&Self::protocol_account_id(),
+			);
+
+			if u128::from(balance) <= 0 {
+				Err(Error::<T>::ProtocolFeeBalanceExhausted)?
+			}
+
+			// Send the dot back to assethub using xcm
+			let xcm_beneficiary: Location =
+				Junction::AccountId32 { network: None, id: beneficiary.clone().into() }.into();
+
+			let xcm_dest = VersionedLocation::V5(Location::new(1, [Parachain(ASSET_HUB_PARA_ID)]));
+			let weight_limit = WeightLimit::Unlimited;
+			let asset = Asset { id: AssetId(asset_id), fun: Fungibility::Fungible(balance.into()) };
+
+			let mut assets = Assets::new();
+			assets.push(asset.clone());
+
+			let custom_xcm_on_dest = Xcm::<()>(vec![DepositAsset {
+				assets: Wild(AllCounted(assets.len() as u32)),
+				beneficiary: xcm_beneficiary.clone(),
+			}]);
+
+			// Send xcm back to assethub
+			pallet_xcm::Pallet::<T>::transfer_assets_using_type_and_then(
+				frame_system::RawOrigin::Signed(Pallet::<T>::protocol_account_id()).into(),
+				Box::new(xcm_dest),
+				Box::new(VersionedAssets::V5(assets.clone())),
+				Box::new(TransferType::DestinationReserve),
+				Box::new(asset.id.into()),
+				Box::new(TransferType::DestinationReserve),
+				Box::new(VersionedXcm::from(custom_xcm_on_dest)),
+				weight_limit,
+			)?;
+
+			Self::deposit_event(Event::<T>::ProtocolFeesWithdrawn { beneficiary, amount: balance });
+
+			Ok(())
+		}
 	}
 }
 

parachain/runtimes/nexus/src/lib.rs

@@ -229,7 +229,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: Cow::Borrowed("nexus"),
 	impl_name: Cow::Borrowed("nexus"),
 	authoring_version: 1,
-	spec_version: 6_100,
+	spec_version: 6_200,
 	impl_version: 0,
 	apis: RUNTIME_API_VERSIONS,
 	transaction_version: 1,