Deposit xcm fees to treasury (#1036)

* wip

* Fist version working

* Test trader and assets to treasury for para-to-para too

* Clean non-affecting changes

* Make a struct in xcm_primitives with the required bounds

* Remove comment

* Add a bit of docu

* IsZero import trait

* PR suggestions

* Apply more pr suggestions

* We cannot lod error since xcmerror does not implement dbug

Co-authored-by: librelois <c@elo.tf>

primitives/xcm/src/lib.rs

@@ -19,21 +19,20 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use frame_support::{
-	traits::{Get, OriginTrait},
+	traits::{tokens::fungibles::Mutate, Get, OriginTrait},
 	weights::{constants::WEIGHT_PER_SECOND, Weight},
 };
+use sp_runtime::traits::Zero;
+use sp_std::borrow::Borrow;
+use sp_std::{convert::TryInto, marker::PhantomData};
 use xcm::latest::{
 	AssetId as xcmAssetId, Error as XcmError, Fungibility,
 	Junction::{AccountKey20, Parachain},
 	Junctions::*,
 	MultiAsset, MultiLocation, NetworkId,
 };
 use xcm_builder::TakeRevenue;
-use xcm_executor::traits::FilterAssetLocation;
-use xcm_executor::traits::WeightTrader;
-
-use sp_std::borrow::Borrow;
-use sp_std::{convert::TryInto, marker::PhantomData};
+use xcm_executor::traits::{FilterAssetLocation, MatchesFungibles, WeightTrader};
 
 use sp_std::vec::Vec;
 
@@ -215,6 +214,21 @@ impl<
 	}
 }
 
+/// Deal with spent fees, deposit them as dictated by R
+impl<
+		AssetId: From<AssetType> + Clone,
+		AssetType: From<MultiLocation> + Clone,
+		AssetIdInfoGetter: UnitsToWeightRatio<AssetId>,
+		R: TakeRevenue,
+	> Drop for FirstAssetTrader<AssetId, AssetType, AssetIdInfoGetter, R>
+{
+	fn drop(&mut self) {
+		if let Some((id, amount, _)) = self.1.clone() {
+			R::take_revenue((id, amount).into());
+		}
+	}
+}
+
 pub trait Reserve {
 	/// Returns assets reserve location.
 	fn reserve(&self) -> Option<MultiLocation>;
@@ -296,3 +310,32 @@ pub trait AccountIdToCurrencyId<Account, CurrencyId> {
 	// Get assetId from account
 	fn account_to_currency_id(account: Account) -> Option<CurrencyId>;
 }
+
+/// XCM fee depositor to which we implement the TakeRevenue trait
+/// It receives a fungibles::Mutate implemented argument, a matcher to convert MultiAsset into
+/// AssetId and amount, and the fee receiver account
+pub struct XcmFeesToAccount<Assets, Matcher, AccountId, ReceiverAccount>(
+	PhantomData<(Assets, Matcher, AccountId, ReceiverAccount)>,
+);
+impl<
+		Assets: Mutate<AccountId>,
+		Matcher: MatchesFungibles<Assets::AssetId, Assets::Balance>,
+		AccountId: Clone,
+		ReceiverAccount: Get<AccountId>,
+	> TakeRevenue for XcmFeesToAccount<Assets, Matcher, AccountId, ReceiverAccount>
+{
+	fn take_revenue(revenue: MultiAsset) {
+		match Matcher::matches_fungibles(&revenue) {
+			Ok((asset_id, amount)) => {
+				if !amount.is_zero() {
+					let ok = Assets::mint_into(asset_id, &ReceiverAccount::get(), amount).is_ok();
+					debug_assert!(ok, "`mint_into` cannot generally fail; qed");
+				}
+			}
+			Err(_) => log::debug!(
+				target: "xcm",
+				"take revenue failed matching fungible"
+			),
+		}
+	}
+}

runtime/moonbase/src/lib.rs

@@ -33,7 +33,6 @@ use fp_rpc::TransactionStatus;
 use pallet_evm_precompile_assets_erc20::AccountIdAssetIdConversion;
 
 use account::AccountId20;
-
 use sp_runtime::traits::Hash as THash;
 
 use frame_support::{
@@ -98,17 +97,19 @@ use sp_std::{
 #[cfg(feature = "std")]
 use sp_version::NativeVersion;
 use sp_version::RuntimeVersion;
-use xcm::v1::{
-	BodyId,
-	Junction::{PalletInstance, Parachain},
-	Junctions, MultiLocation, NetworkId,
-};
+use xcm::latest::prelude::*;
 
 use nimbus_primitives::{CanAuthor, NimbusId};
 
 mod precompiles;
 use precompiles::{MoonbasePrecompiles, ASSET_PRECOMPILE_ADDRESS_PREFIX};
 
+use xcm_primitives::{
+	AccountIdToCurrencyId, AccountIdToMultiLocation, AsAssetType, FirstAssetTrader,
+	MultiNativeAsset, SignedToAccountId20, UtilityAvailableCalls, UtilityEncodeCall,
+	XcmFeesToAccount, XcmTransact,
+};
+
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
 
@@ -973,7 +974,7 @@ pub type FungiblesTransactor = FungiblesAdapter<
 		ConvertedConcreteAssetId<
 			AssetId,
 			Balance,
-			xcm_primitives::AsAssetType<AssetId, AssetType, AssetManager>,
+			AsAssetType<AssetId, AssetType, AssetManager>,
 			JustTry,
 		>,
 	),
@@ -1052,6 +1053,28 @@ pub type XcmBarrier = (
 	AllowSubscriptionsFrom<Everything>,
 );
 
+parameter_types! {
+	/// Xcm fees will go to the treasury account
+	pub XcmFeesAccount: AccountId = Treasury::account_id();
+}
+
+/// This is the struct that will handle the revenue from xcm fees
+/// We do not burn anything because we want to mimic exactly what
+/// the sovereign account has
+pub type XcmFeesToAccount_ = XcmFeesToAccount<
+	Assets,
+	(
+		ConvertedConcreteAssetId<
+			AssetId,
+			Balance,
+			AsAssetType<AssetId, AssetType, AssetManager>,
+			JustTry,
+		>,
+	),
+	AccountId,
+	XcmFeesAccount,
+>;
+
 pub struct XcmExecutorConfig;
 impl xcm_executor::Config for XcmExecutorConfig {
 	type Call = Call;
@@ -1060,7 +1083,7 @@ impl xcm_executor::Config for XcmExecutorConfig {
 	type AssetTransactor = AssetTransactors;
 	type OriginConverter = XcmOriginToTransactDispatchOrigin;
 	// Filter to the reserve withdraw operations
-	type IsReserve = xcm_primitives::MultiNativeAsset;
+	type IsReserve = MultiNativeAsset;
 	type IsTeleporter = (); // No teleport
 	type LocationInverter = LocationInverter<Ancestry>;
 	type Barrier = XcmBarrier;
@@ -1077,7 +1100,7 @@ impl xcm_executor::Config for XcmExecutorConfig {
 			Balances,
 			DealWithFees<Runtime>,
 		>,
-		xcm_primitives::FirstAssetTrader<AssetId, AssetType, AssetManager, ()>,
+		FirstAssetTrader<AssetId, AssetType, AssetManager, XcmFeesToAccount_>,
 	);
 	type ResponseHandler = PolkadotXcm;
 	type SubscriptionService = PolkadotXcm;
@@ -1092,8 +1115,7 @@ parameter_types! {
 }
 
 // Converts a Signed Local Origin into a MultiLocation
-pub type LocalOriginToLocation =
-	xcm_primitives::SignedToAccountId20<Origin, AccountId, RelayNetwork>;
+pub type LocalOriginToLocation = SignedToAccountId20<Origin, AccountId, RelayNetwork>;
 
 /// The means for routing XCM messages which are not for local execution into the right message
 /// queues.
@@ -1280,7 +1302,7 @@ pub enum CurrencyId {
 	OtherReserve(AssetId),
 }
 
-impl xcm_primitives::AccountIdToCurrencyId<AccountId, CurrencyId> for Runtime {
+impl AccountIdToCurrencyId<AccountId, CurrencyId> for Runtime {
 	fn account_to_currency_id(account: AccountId) -> Option<CurrencyId> {
 		match account {
 			// the self-reserve currency is identified by the pallet-balances address
@@ -1326,9 +1348,9 @@ impl orml_xtokens::Config for Runtime {
 	type Event = Event;
 	type Balance = Balance;
 	type CurrencyId = CurrencyId;
-	type AccountIdToMultiLocation = xcm_primitives::AccountIdToMultiLocation<AccountId>;
+	type AccountIdToMultiLocation = AccountIdToMultiLocation<AccountId>;
 	type CurrencyIdConvert =
-		CurrencyIdtoMultiLocation<xcm_primitives::AsAssetType<AssetId, AssetType, AssetManager>>;
+		CurrencyIdtoMultiLocation<AsAssetType<AssetId, AssetType, AssetManager>>;
 	type XcmExecutor = XcmExecutor;
 	type SelfLocation = SelfLocation;
 	type Weigher = XcmWeigher;
@@ -1354,8 +1376,8 @@ impl TryFrom<u8> for Transactors {
 	}
 }
 
-impl xcm_primitives::UtilityEncodeCall for Transactors {
-	fn encode_call(self, call: xcm_primitives::UtilityAvailableCalls) -> Vec<u8> {
+impl UtilityEncodeCall for Transactors {
+	fn encode_call(self, call: UtilityAvailableCalls) -> Vec<u8> {
 		match self {
 			// Shall we use westend for moonbase? The tests are probably based on rococo
 			// but moonbase-alpha is attached to westend-runtime I think
@@ -1364,7 +1386,7 @@ impl xcm_primitives::UtilityEncodeCall for Transactors {
 	}
 }
 
-impl xcm_primitives::XcmTransact for Transactors {
+impl XcmTransact for Transactors {
 	fn destination(self) -> MultiLocation {
 		match self {
 			Transactors::Relay => MultiLocation::parent(),
@@ -1379,9 +1401,9 @@ impl xcm_transactor::Config for Runtime {
 	type DerivativeAddressRegistrationOrigin = EnsureRoot<AccountId>;
 	type SovereignAccountDispatcherOrigin = EnsureRoot<AccountId>;
 	type CurrencyId = CurrencyId;
-	type AccountIdToMultiLocation = xcm_primitives::AccountIdToMultiLocation<AccountId>;
+	type AccountIdToMultiLocation = AccountIdToMultiLocation<AccountId>;
 	type CurrencyIdToMultiLocation =
-		CurrencyIdtoMultiLocation<xcm_primitives::AsAssetType<AssetId, AssetType, AssetManager>>;
+		CurrencyIdtoMultiLocation<AsAssetType<AssetId, AssetType, AssetManager>>;
 	type XcmExecutor = XcmExecutor;
 	type XcmSender = XcmRouter;
 	type SelfLocation = SelfLocation;

runtime/moonbase/tests/xcm_mock/mod.rs

@@ -118,6 +118,7 @@ pub fn relay_ext() -> sp_io::TestExternalities {
 pub type RelayChainPalletXcm = pallet_xcm::Pallet<relay_chain::Runtime>;
 pub type ParachainPalletXcm = pallet_xcm::Pallet<parachain::Runtime>;
 pub type Assets = pallet_assets::Pallet<parachain::Runtime>;
+pub type Treasury = pallet_treasury::Pallet<parachain::Runtime>;
 pub type AssetManager = pallet_asset_manager::Pallet<parachain::Runtime>;
 pub type XTokens = orml_xtokens::Pallet<parachain::Runtime>;
 pub type RelayBalances = pallet_balances::Pallet<relay_chain::Runtime>;

runtime/moonbase/tests/xcm_mock/parachain.rs

@@ -20,13 +20,16 @@ use frame_support::{
 	construct_runtime, parameter_types,
 	traits::{Everything, Get, Nothing, PalletInfo as PalletInfoTrait},
 	weights::Weight,
+	PalletId,
 };
+
 use frame_system::EnsureRoot;
 use parity_scale_codec::{Decode, Encode};
 use sp_core::H256;
 use sp_runtime::{
 	testing::Header,
 	traits::{Hash, IdentityLookup},
+	Permill,
 };
 use sp_std::{convert::TryFrom, prelude::*};
 use xcm::{latest::prelude::*, Version as XcmVersion, VersionedXcm};
@@ -218,6 +221,27 @@ pub type Barrier = (
 	// Subscriptions for version tracking are OK.
 	AllowSubscriptionsFrom<Everything>,
 );
+
+parameter_types! {
+	/// Xcm fees will go to the treasury account
+	pub XcmFeesAccount: AccountId = Treasury::account_id();
+}
+
+/// This is the struct that will handle the revenue from xcm fees
+pub type XcmFeesToAccount_ = xcm_primitives::XcmFeesToAccount<
+	Assets,
+	(
+		ConvertedConcreteAssetId<
+			AssetId,
+			Balance,
+			xcm_primitives::AsAssetType<AssetId, AssetType, AssetManager>,
+			JustTry,
+		>,
+	),
+	AccountId,
+	XcmFeesAccount,
+>;
+
 parameter_types! {
 	// We cannot skip the native trader for some specific tests, so we will have to work with
 	// a native trader that charges same number of units as weight
@@ -249,7 +273,7 @@ impl Config for XcmConfig {
 	type Weigher = FixedWeightBounds<UnitWeightCost, Call, MaxInstructions>;
 	type Trader = (
 		FixedRateOfFungible<ParaTokensPerSecond, ()>,
-		xcm_primitives::FirstAssetTrader<AssetId, AssetType, AssetManager, ()>,
+		xcm_primitives::FirstAssetTrader<AssetId, AssetType, AssetManager, XcmFeesToAccount_>,
 	);
 
 	type ResponseHandler = PolkadotXcm;
@@ -313,6 +337,31 @@ impl orml_xtokens::Config for Runtime {
 	type LocationInverter = LocationInverter<Ancestry>;
 }
 
+parameter_types! {
+	pub const ProposalBond: Permill = Permill::from_percent(5);
+	pub const ProposalBondMinimum: Balance = 0;
+	pub const SpendPeriod: u64 = 0;
+	pub const TreasuryId: PalletId = PalletId(*b"pc/trsry");
+	pub const MaxApprovals: u32 = 100;
+}
+
+impl pallet_treasury::Config for Runtime {
+	type PalletId = TreasuryId;
+	type Currency = Balances;
+	type ApproveOrigin = EnsureRoot<AccountId>;
+	type RejectOrigin = EnsureRoot<AccountId>;
+	type Event = Event;
+	type OnSlash = Treasury;
+	type ProposalBond = ProposalBond;
+	type ProposalBondMinimum = ProposalBondMinimum;
+	type SpendPeriod = SpendPeriod;
+	type Burn = ();
+	type BurnDestination = ();
+	type MaxApprovals = MaxApprovals;
+	type WeightInfo = ();
+	type SpendFunds = ();
+}
+
 #[frame_support::pallet]
 pub mod mock_msg_queue {
 	use super::*;
@@ -700,6 +749,7 @@ construct_runtime!(
 		XTokens: orml_xtokens::{Pallet, Call, Storage, Event<T>},
 		AssetManager: pallet_asset_manager::{Pallet, Call, Storage, Event<T>},
 		XcmTransactor: xcm_transactor::{Pallet, Call, Storage, Event<T>},
+		Treasury: pallet_treasury::{Pallet, Storage, Config, Event<T>, Call}
 	}
 );