SNO-624: Charge fee for outbound operations

parachain/pallets/control/Cargo.toml

@@ -21,6 +21,7 @@ frame-benchmarking = { git = "https://github.com/paritytech/substrate.git", bran
 frame-support = { git = "https://github.com/paritytech/substrate.git", branch = "master", default-features = false }
 frame-system = { git = "https://github.com/paritytech/substrate.git", branch = "master", default-features = false }
 snowbridge-core = { path = "../../primitives/core", default-features = false }
+snowbridge-router-primitives = { path = "../../primitives/router", default-features = false }
 
 sp-core = { git = "https://github.com/paritytech/substrate.git", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate.git", branch = "master", default-features = false }
@@ -36,6 +37,7 @@ ethabi = { git = "https://github.com/Snowfork/ethabi-decode.git", package = "eth
 [dev-dependencies]
 hex = "0.4.1"
 hex-literal = { version = "0.4.1" }
+pallet-balances = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
 
 [features]
 default = ["std"]
@@ -52,7 +54,8 @@ std = [
 	"xcm/std",
 	"xcm-builder/std",
 	"xcm-executor/std",
-	"ethabi/std"
+	"ethabi/std",
+	"snowbridge-router-primitives/std",
 ]
 runtime-benchmarks = [
 	"frame-benchmarking/runtime-benchmarks",

parachain/pallets/control/src/lib.rs

@@ -17,6 +17,7 @@ mod benchmarking;
 pub mod weights;
 pub use weights::*;
 
+use frame_support::traits::fungible::{Inspect, Mutate};
 use snowbridge_core::{
 	outbound::{Command, Message, OperatingMode, OutboundQueue as OutboundQueueTrait, ParaId},
 	AgentId,
@@ -31,17 +32,27 @@ pub use pallet::*;
 
 pub const LOG_TARGET: &str = "snowbridge-control";
 
+type BalanceOf<T> =
+	<<T as pallet::Config>::Token as Inspect<<T as frame_system::Config>::AccountId>>::Balance;
+
 #[frame_support::pallet]
 pub mod pallet {
 	use super::*;
-	use frame_support::{log, pallet_prelude::*, traits::EnsureOrigin};
+	use frame_support::{
+		log,
+		pallet_prelude::*,
+		sp_runtime::{traits::AccountIdConversion, AccountId32},
+		traits::{tokens::Preservation, EnsureOrigin},
+		PalletId,
+	};
 	use frame_system::pallet_prelude::*;
+	use snowbridge_core::outbound::ControlOperation;
 
 	#[pallet::pallet]
 	pub struct Pallet<T>(_);
 
 	#[pallet::config]
-	pub trait Config: frame_system::Config {
+	pub trait Config: frame_system::Config<AccountId = AccountId32> {
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// General-purpose hasher
@@ -63,26 +74,41 @@ pub mod pallet {
 		type ChannelOrigin: EnsureOrigin<Self::RuntimeOrigin, Success = MultiLocation>;
 
 		/// Converts MultiLocation to H256 in a way that is stable across multiple versions of XCM
-		type AgentHashedDescription: ConvertLocation<H256>;
+		type AgentIdOf: ConvertLocation<H256>;
+
+		type SovereignAccountOf: ConvertLocation<Self::AccountId>;
 
 		/// The universal location
 		type UniversalLocation: Get<InteriorMultiLocation>;
 
 		/// Location of the relay chain
 		type RelayLocation: Get<MultiLocation>;
 
+		/// Token reserved for control operations
+		type Token: Mutate<Self::AccountId>;
+
 		type WeightInfo: WeightInfo;
 	}
 
 	#[pallet::event]
 	#[pallet::generate_deposit(pub(super) fn deposit_event)]
 	pub enum Event<T: Config> {
 		/// An Upgrade message was sent to the Gateway
-		Upgrade { impl_address: H160, impl_code_hash: H256, params_hash: Option<H256> },
+		Upgrade {
+			impl_address: H160,
+			impl_code_hash: H256,
+			params_hash: Option<H256>,
+		},
 		/// An CreateAgent message was sent to the Gateway
-		CreateAgent { location: Box<MultiLocation>, agent_id: AgentId },
+		CreateAgent {
+			location: Box<MultiLocation>,
+			agent_id: AgentId,
+		},
 		/// An CreateChannel message was sent to the Gateway
-		CreateChannel { para_id: ParaId, agent_id: AgentId },
+		CreateChannel {
+			para_id: ParaId,
+			agent_id: AgentId,
+		},
 		/// An UpdateChannel message was sent to the Gateway
 		UpdateChannel {
 			para_id: ParaId,
@@ -92,9 +118,19 @@ pub mod pallet {
 			reward: u128,
 		},
 		/// An SetOperatingMode message was sent to the Gateway
-		SetOperatingMode { mode: OperatingMode },
+		SetOperatingMode {
+			mode: OperatingMode,
+		},
 		/// An TransferNativeFromAgent message was sent to the Gateway
-		TransferNativeFromAgent { agent_id: AgentId, recipient: H160, amount: u128 },
+		TransferNativeFromAgent {
+			agent_id: AgentId,
+			recipient: H160,
+			amount: u128,
+		},
+		FeeUpdated {
+			operation: ControlOperation,
+			fee: BalanceOf<T>,
+		},
 	}
 
 	#[pallet::error]
@@ -108,6 +144,7 @@ pub mod pallet {
 		AgentNotExist,
 		ChannelAlreadyCreated,
 		ChannelNotExist,
+		LocationToAgentAccountConversionFailed,
 	}
 
 	#[pallet::storage]
@@ -116,6 +153,10 @@ pub mod pallet {
 	#[pallet::storage]
 	pub type Channels<T: Config> = StorageMap<_, Twox64Concat, ParaId, (), OptionQuery>;
 
+	#[pallet::storage]
+	pub type ControlOperationFee<T: Config> =
+		StorageMap<_, Twox64Concat, ControlOperation, BalanceOf<T>, ValueQuery>;
+
 	#[pallet::call]
 	impl<T: Config> Pallet<T> {
 		/// Sends a message to the Gateway contract to upgrade itself.
@@ -170,6 +211,11 @@ pub mod pallet {
 				location
 			);
 
+			Self::reserve_deposit(
+				Self::agent_account_id(&location)?,
+				ControlOperationFee::<T>::get(ControlOperation::CreateAgent),
+			)?;
+
 			// Record the agent id or fail if it has already been created
 			ensure!(!Agents::<T>::contains_key(agent_id), Error::<T>::AgentAlreadyCreated);
 
@@ -197,14 +243,17 @@ pub mod pallet {
 		pub fn create_channel(origin: OriginFor<T>) -> DispatchResult {
 			let location: MultiLocation = T::ChannelOrigin::ensure_origin(origin)?;
 
-			let (agent_id, some_para_id, _) = Self::convert_location(location)?;
+			let (agent_id, para_id, location) = Self::convert_location(location)?;
 
 			ensure!(Agents::<T>::contains_key(agent_id), Error::<T>::AgentNotExist);
 
-			let para_id = some_para_id.ok_or(Error::<T>::LocationToParaIdConversionFailed)?;
-
 			ensure!(!Channels::<T>::contains_key(para_id), Error::<T>::ChannelAlreadyCreated);
 
+			Self::reserve_deposit(
+				Self::agent_account_id(&location)?,
+				ControlOperationFee::<T>::get(ControlOperation::CreateChannel),
+			)?;
+
 			Channels::<T>::insert(para_id, ());
 
 			let message = Message {
@@ -231,14 +280,17 @@ pub mod pallet {
 		) -> DispatchResult {
 			let location: MultiLocation = T::ChannelOrigin::ensure_origin(origin)?;
 
-			let (agent_id, some_para_id, _) = Self::convert_location(location)?;
+			let (agent_id, para_id, location) = Self::convert_location(location)?;
 
 			ensure!(Agents::<T>::contains_key(agent_id), Error::<T>::AgentNotExist);
 
-			let para_id = some_para_id.ok_or(Error::<T>::LocationToParaIdConversionFailed)?;
-
 			ensure!(Channels::<T>::contains_key(para_id), Error::<T>::ChannelNotExist);
 
+			Self::reserve_deposit(
+				Self::agent_account_id(&location)?,
+				ControlOperationFee::<T>::get(ControlOperation::UpdateChannel),
+			)?;
+
 			let message = Message {
 				origin: T::OwnParaId::get(),
 				command: Command::UpdateChannel { para_id, mode, fee, reward },
@@ -281,10 +333,15 @@ pub mod pallet {
 		) -> DispatchResult {
 			let location: MultiLocation = T::AgentOrigin::ensure_origin(origin)?;
 
-			let (agent_id, _, _) = Self::convert_location(location)?;
+			let (agent_id, _, location) = Self::convert_location(location)?;
 
 			ensure!(Agents::<T>::contains_key(agent_id), Error::<T>::AgentNotExist);
 
+			Self::reserve_deposit(
+				Self::agent_account_id(&location)?,
+				ControlOperationFee::<T>::get(ControlOperation::TransferNativeFromAgent),
+			)?;
+
 			let message = Message {
 				origin: T::OwnParaId::get(),
 				command: Command::TransferNativeFromAgent { agent_id, recipient, amount },
@@ -299,6 +356,27 @@ pub mod pallet {
 
 			Ok(())
 		}
+
+		/// - `update`: (ControlOperation, Fee).
+		#[pallet::call_index(6)]
+		#[pallet::weight(T::WeightInfo::update_operation_fee())]
+		pub fn update_operation_fee(
+			origin: OriginFor<T>,
+			operation: ControlOperation,
+			update_fee: BalanceOf<T>,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			ControlOperationFee::<T>::mutate(&operation, |fee| {
+				*fee = update_fee;
+				Self::deposit_event(Event::<T>::FeeUpdated {
+					operation: operation.clone(),
+					fee: update_fee,
+				});
+			});
+
+			Ok(())
+		}
 	}
 
 	impl<T: Config> Pallet<T> {
@@ -311,25 +389,39 @@ pub mod pallet {
 
 		pub fn convert_location(
 			mut location: MultiLocation,
-		) -> Result<(H256, Option<ParaId>, MultiLocation), DispatchError> {
+		) -> Result<(H256, ParaId, MultiLocation), DispatchError> {
 			// Normalize all locations relative to the relay chain.
 			let relay_location = T::RelayLocation::get();
 			location
 				.reanchor(&relay_location, T::UniversalLocation::get())
 				.map_err(|_| Error::<T>::LocationReanchorFailed)?;
 
-			// Only allow Parachain as origin location
-			let para_id = match location {
-				MultiLocation { parents: 0, interior: X1(Parachain(index)) } =>
-					Some((index).into()),
+			let para_id = match location.interior.first() {
+				Some(Parachain(index)) => Some((*index).into()),
 				_ => None,
-			};
+			}
+			.ok_or(Error::<T>::LocationToParaIdConversionFailed)?;
 
 			// Hash the location to produce an agent id
-			let agent_id = T::AgentHashedDescription::convert_location(&location)
+			let agent_id = T::AgentIdOf::convert_location(&location)
 				.ok_or(Error::<T>::LocationToAgentIdConversionFailed)?;
 
 			Ok((agent_id, para_id, location))
 		}
+
+		pub fn account_id() -> T::AccountId {
+			PalletId(*b"snow/ctl").into_account_truncating()
+		}
+
+		pub fn reserve_deposit(payer: T::AccountId, amount: BalanceOf<T>) -> DispatchResult {
+			T::Token::transfer(&payer, &Self::account_id(), amount, Preservation::Preserve)?;
+			Ok(())
+		}
+
+		pub fn agent_account_id(location: &MultiLocation) -> Result<T::AccountId, DispatchError> {
+			let agent_account = T::SovereignAccountOf::convert_location(location)
+				.ok_or(Error::<T>::LocationToAgentAccountConversionFailed)?;
+			Ok(agent_account)
+		}
 	}
 }

parachain/pallets/control/src/mock.rs

@@ -32,6 +32,7 @@ frame_support::construct_runtime!(
 		UncheckedExtrinsic = UncheckedExtrinsic,
 	{
 		System: frame_system,
+		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
 		EthereumControl: snowbridge_control,
 	}
 );
@@ -54,7 +55,7 @@ impl frame_system::Config for Test {
 	type BlockHashCount = ConstU64<250>;
 	type Version = ();
 	type PalletInfo = PalletInfo;
-	type AccountData = ();
+	type AccountData = pallet_balances::AccountData<u64>;
 	type OnNewAccount = ();
 	type OnKilledAccount = ();
 	type SystemWeightInfo = ();
@@ -63,6 +64,22 @@ impl frame_system::Config for Test {
 	type MaxConsumers = frame_support::traits::ConstU32<16>;
 }
 
+impl pallet_balances::Config for Test {
+	type MaxLocks = ();
+	type MaxReserves = ();
+	type ReserveIdentifier = [u8; 8];
+	type Balance = u64;
+	type RuntimeEvent = RuntimeEvent;
+	type DustRemoval = ();
+	type ExistentialDeposit = ConstU64<1>;
+	type AccountStore = System;
+	type WeightInfo = ();
+	type FreezeIdentifier = ();
+	type MaxFreezes = ();
+	type RuntimeHoldReason = ();
+	type MaxHolds = ();
+}
+
 parameter_types! {
 	pub const OwnParaId: ParaId = ParaId::new(1013);
 	pub const MaxUpgradeDataSize: u32 = 1024;
@@ -195,7 +212,9 @@ impl snowbridge_control::Config for Test {
 	type ChannelOrigin = EnsureOriginFromTable;
 	type UniversalLocation = UniversalLocation;
 	type RelayLocation = RelayLocation;
-	type AgentHashedDescription = HashedDescription<H256, DescribeFamily<DescribeAllTerminal>>;
+	type AgentIdOf = HashedDescription<H256, DescribeFamily<DescribeAllTerminal>>;
+	type SovereignAccountOf = HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>;
+	type Token = Balances;
 	type WeightInfo = ();
 }