Foreign assets creation via token reserve

pallets/moonbeam-foreign-assets/src/benchmarks.rs

@@ -16,18 +16,27 @@
 
 #![cfg(feature = "runtime-benchmarks")]
 
-use crate::{AssetStatus, Call, Config, Pallet};
-use frame_benchmarking::{benchmarks, impl_benchmark_test_suite};
+use crate::{pallet, AssetStatus, Call, Config, Pallet};
+use frame_benchmarking::{account, benchmarks, impl_benchmark_test_suite};
 use frame_support::pallet_prelude::*;
+use frame_support::traits::Currency;
 use frame_system::RawOrigin;
 use sp_runtime::traits::ConstU32;
 use sp_runtime::BoundedVec;
 use xcm::latest::prelude::*;
 
+fn create_funded_user<T: Config>(string: &'static str, n: u32, balance: u32) -> T::AccountId {
+	const SEED: u32 = 0;
+	let user = account(string, n, SEED);
+	let _ = <T as pallet::Config>::Currency::make_free_balance_be(&user, balance.into());
+	let _ = <T as pallet::Config>::Currency::issue(balance.into());
+	user
+}
 fn create_n_foreign_asset<T: Config>(n: u32) -> DispatchResult {
+	let user: T::AccountId = create_funded_user::<T>("user", n, 100);
 	for i in 1..=n {
 		Pallet::<T>::create_foreign_asset(
-			RawOrigin::Root.into(),
+			RawOrigin::Signed(user.clone()).into(),
 			i as u128,
 			location_of(i),
 			18,
@@ -53,7 +62,7 @@ benchmarks! {
 	create_foreign_asset {
 		create_n_foreign_asset::<T>(T::MaxForeignAssets::get().saturating_sub(1))?;
 		let asset_id = T::MaxForeignAssets::get() as u128;
-	}: _(RawOrigin::Root, asset_id, Location::parent(), 18, str_to_bv("MT"), str_to_bv("Mytoken"))
+	}: _(RawOrigin::Signed(create_funded_user::<T>("user", 1, 100)), asset_id, Location::parent(), 18, str_to_bv("MT"), str_to_bv("Mytoken"))
 	verify {
 		assert_eq!(
 			Pallet::<T>::assets_by_id(asset_id),

pallets/moonbeam-foreign-assets/src/lib.rs

@@ -107,8 +107,9 @@ pub enum AssetStatus {
 #[pallet]
 pub mod pallet {
 	use super::*;
+	use frame_support::traits::{Currency, ReservableCurrency};
 	use pallet_evm::{GasWeightMapping, Runner};
-	use sp_runtime::traits::{AccountIdConversion, Convert};
+	use sp_runtime::traits::{AccountIdConversion, AtLeast32BitUnsigned, Convert};
 	use xcm_executor::traits::ConvertLocation;
 	use xcm_executor::traits::Error as MatchError;
 	use xcm_executor::AssetsInHolding;
@@ -121,7 +122,7 @@ pub mod pallet {
 	pub const PALLET_ID: frame_support::PalletId = frame_support::PalletId(*b"forgasst");
 
 	#[pallet::config]
-	pub trait Config: frame_system::Config + pallet_evm::Config {
+	pub trait Config: frame_system::Config + pallet_evm::Config + scale_info::TypeInfo {
 		// Convert AccountId to H160
 		type AccountIdToH160: Convert<Self::AccountId, H160>;
 
@@ -131,23 +132,13 @@ pub mod pallet {
 		/// EVM runner
 		type EvmRunner: Runner<Self>;
 
-		/// Origin that is allowed to create a new foreign assets
-		type ForeignAssetCreatorOrigin: EnsureOrigin<Self::RuntimeOrigin>;
-
-		/// Origin that is allowed to freeze all tokens of a foreign asset
-		type ForeignAssetFreezerOrigin: EnsureOrigin<Self::RuntimeOrigin>;
-
-		/// Origin that is allowed to modify asset information for foreign assets
-		type ForeignAssetModifierOrigin: EnsureOrigin<Self::RuntimeOrigin>;
-
-		/// Origin that is allowed to unfreeze all tokens of a foreign asset that was previously
-		/// frozen
-		type ForeignAssetUnfreezerOrigin: EnsureOrigin<Self::RuntimeOrigin>;
+		/// Origin that is allowed to create new foreign assets
+		type EnsureXcmLocation: EnsureXcmLocation<Self>;
 
 		/// Hook to be called when new foreign asset is registered.
 		type OnForeignAssetCreated: ForeignAssetCreatedHook<Location>;
 
-		/// Maximum nulmbers of differnt foreign assets
+		/// Maximum numbers of differnt foreign assets
 		type MaxForeignAssets: Get<u32>;
 
 		/// The overarching event type.
@@ -158,8 +149,27 @@ pub mod pallet {
 
 		// Convert XCM Location to H160
 		type XcmLocationToH160: ConvertLocation<H160>;
+
+		/// Amount of tokens required to lock for creating a new foreign asset
+		type ForeignAssetCreationDeposit: Get<BalanceOf<Self>>;
+
+		/// The balance type for locking funds
+		type Balance: Member
+			+ Parameter
+			+ AtLeast32BitUnsigned
+			+ Default
+			+ Copy
+			+ MaybeSerializeDeserialize
+			+ MaxEncodedLen
+			+ TypeInfo;
+
+		/// The currency type for locking funds
+		type Currency: ReservableCurrency<Self::AccountId>;
 	}
 
+	type BalanceOf<T> =
+		<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;
+
 	pub type AssetBalance = U256;
 	pub type AssetId = u128;
 
@@ -177,6 +187,10 @@ pub mod pallet {
 		EvmCallPauseFail,
 		EvmCallUnpauseFail,
 		EvmInternalError,
+		/// Account has insufficient balance for locking
+		InsufficientBalance,
+		OriginIsNotAssetCreator,
+		CannotConvertLocationToAccount,
 		InvalidSymbol,
 		InvalidTokenName,
 		LocationAlreadyExists,
@@ -191,6 +205,7 @@ pub mod pallet {
 			contract_address: H160,
 			asset_id: AssetId,
 			xcm_location: Location,
+			deposit: Option<BalanceOf<T>>,
 		},
 		/// Changed the xcm type mapping for a given asset id
 		ForeignAssetXcmLocationChanged {
@@ -207,6 +222,10 @@ pub mod pallet {
 			asset_id: AssetId,
 			xcm_location: Location,
 		},
+		/// Tokens have been locked for asset creation
+		TokensLocked(T::AccountId, AssetId, AssetBalance),
+		/// Lock verification failed
+		LockVerificationFailed(T::AccountId, AssetId),
 	}
 
 	/// Mapping from an asset id to a Foreign asset type.
@@ -225,6 +244,18 @@ pub mod pallet {
 	pub type AssetsByLocation<T: Config> =
 		StorageMap<_, Blake2_128Concat, Location, (AssetId, AssetStatus)>;
 
+	/// Mapping from an asset id to its creation details
+	#[pallet::storage]
+	#[pallet::getter(fn assets_creation_details)]
+	pub type AssetsCreationDetails<T: Config> =
+		StorageMap<_, Blake2_128Concat, AssetId, AssetCreationDetails<T>>;
+
+	#[derive(Clone, Decode, Encode, Eq, PartialEq, Debug, TypeInfo, MaxEncodedLen)]
+	pub struct AssetCreationDetails<T: Config> {
+		pub owner: T::AccountId,
+		pub deposit: Option<BalanceOf<T>>,
+	}
+
 	impl<T: Config> Pallet<T> {
 		/// The account ID of this pallet
 		#[inline]
@@ -242,6 +273,8 @@ pub mod pallet {
 			H160(buffer)
 		}
 
+		/// This method only exists for migration purposes and will be deleted once the
+		/// foreign assets migration is finished.
 		pub fn register_foreign_asset(
 			asset_id: AssetId,
 			xcm_location: Location,
@@ -274,18 +307,26 @@ pub mod pallet {
 			let name = core::str::from_utf8(&name).map_err(|_| Error::<T>::InvalidTokenName)?;
 
 			let contract_address = EvmCaller::<T>::erc20_create(asset_id, decimals, symbol, name)?;
+			let owner = T::EnsureXcmLocation::account_for_location(&xcm_location)
+				.ok_or(Error::<T>::CannotConvertLocationToAccount)?;
 
 			// Insert the association assetId->foreigAsset
 			// Insert the association foreigAsset->assetId
 			AssetsById::<T>::insert(&asset_id, &xcm_location);
 			AssetsByLocation::<T>::insert(&xcm_location, (asset_id, AssetStatus::Active));
-
-			T::OnForeignAssetCreated::on_asset_created(&xcm_location, &asset_id);
+			AssetsCreationDetails::<T>::insert(
+				&asset_id,
+				AssetCreationDetails {
+					owner,
+					deposit: None,
+				},
+			);
 
 			Self::deposit_event(Event::ForeignAssetCreated {
 				contract_address,
 				asset_id,
 				xcm_location,
+				deposit: None,
 			});
 			Ok(())
 		}
@@ -355,7 +396,8 @@ pub mod pallet {
 			symbol: BoundedVec<u8, ConstU32<256>>,
 			name: BoundedVec<u8, ConstU32<256>>,
 		) -> DispatchResult {
-			T::ForeignAssetCreatorOrigin::ensure_origin(origin)?;
+			let owner_account =
+				T::EnsureXcmLocation::ensure_xcm_origin(origin.clone(), Some(&xcm_location))?;
 
 			// Ensure such an assetId does not exist
 			ensure!(
@@ -380,20 +422,34 @@ pub mod pallet {
 
 			let symbol = core::str::from_utf8(&symbol).map_err(|_| Error::<T>::InvalidSymbol)?;
 			let name = core::str::from_utf8(&name).map_err(|_| Error::<T>::InvalidTokenName)?;
-
 			let contract_address = EvmCaller::<T>::erc20_create(asset_id, decimals, symbol, name)?;
+			let deposit = T::ForeignAssetCreationDeposit::get();
+			let owner = owner_account.clone();
 
 			// Insert the association assetId->foreigAsset
 			// Insert the association foreigAsset->assetId
 			AssetsById::<T>::insert(&asset_id, &xcm_location);
 			AssetsByLocation::<T>::insert(&xcm_location, (asset_id, AssetStatus::Active));
 
+			// Reserve _deposit_ amount of funds from the caller
+			<T as Config>::Currency::reserve(&owner_account, deposit)?;
+
+			// Insert the amount that is reserved from the user
+			AssetsCreationDetails::<T>::insert(
+				&asset_id,
+				AssetCreationDetails {
+					owner,
+					deposit: Some(deposit),
+				},
+			);
+
 			T::OnForeignAssetCreated::on_asset_created(&xcm_location, &asset_id);
 
 			Self::deposit_event(Event::ForeignAssetCreated {
 				contract_address,
 				asset_id,
 				xcm_location,
+				deposit: Some(deposit),
 			});
 			Ok(())
 		}
@@ -408,11 +464,14 @@ pub mod pallet {
 			asset_id: AssetId,
 			new_xcm_location: Location,
 		) -> DispatchResult {
-			T::ForeignAssetModifierOrigin::ensure_origin(origin)?;
+			// Ensures that the origin is an XCM location that contains the asset
+			T::EnsureXcmLocation::ensure_xcm_origin(origin.clone(), Some(&new_xcm_location))?;
 
 			let previous_location =
 				AssetsById::<T>::get(&asset_id).ok_or(Error::<T>::AssetDoesNotExist)?;
 
+			T::EnsureXcmLocation::ensure_xcm_origin(origin, Some(&previous_location))?;
+
 			ensure!(
 				!AssetsByLocation::<T>::contains_key(&new_xcm_location),
 				Error::<T>::LocationAlreadyExists
@@ -441,11 +500,16 @@ pub mod pallet {
 			asset_id: AssetId,
 			allow_xcm_deposit: bool,
 		) -> DispatchResult {
-			T::ForeignAssetFreezerOrigin::ensure_origin(origin)?;
+			// Ensure that the origin is coming from an XCM.
+			T::EnsureXcmLocation::ensure_xcm_origin(origin.clone(), None)?;
 
 			let xcm_location =
 				AssetsById::<T>::get(&asset_id).ok_or(Error::<T>::AssetDoesNotExist)?;
 
+			// Ensures that the origin is an XCM location that owns the asset
+			// represented by the assets xcm location
+			T::EnsureXcmLocation::ensure_xcm_origin(origin, Some(&xcm_location))?;
+
 			let (_asset_id, asset_status) = AssetsByLocation::<T>::get(&xcm_location)
 				.ok_or(Error::<T>::CorruptedStorageOrphanLocation)?;
 
@@ -475,10 +539,12 @@ pub mod pallet {
 		#[pallet::call_index(3)]
 		#[pallet::weight(<T as Config>::WeightInfo::unfreeze_foreign_asset())]
 		pub fn unfreeze_foreign_asset(origin: OriginFor<T>, asset_id: AssetId) -> DispatchResult {
-			T::ForeignAssetUnfreezerOrigin::ensure_origin(origin)?;
+			T::EnsureXcmLocation::ensure_xcm_origin(origin.clone(), None)?;
 
 			let xcm_location =
 				AssetsById::<T>::get(&asset_id).ok_or(Error::<T>::AssetDoesNotExist)?;
+			// Ensures that the origin is an XCM location that contains the asset
+			T::EnsureXcmLocation::ensure_xcm_origin(origin, Some(&xcm_location))?;
 
 			let (_asset_id, asset_status) = AssetsByLocation::<T>::get(&xcm_location)
 				.ok_or(Error::<T>::CorruptedStorageOrphanLocation)?;
@@ -596,4 +662,13 @@ pub mod pallet {
 			AssetsById::<T>::get(asset_id)
 		}
 	}
+
+	/// A trait to ensure that the origin is an XCM location that contains the asset
+	pub trait EnsureXcmLocation<T: Config> {
+		fn ensure_xcm_origin(
+			origin: T::RuntimeOrigin,
+			location: Option<&Location>,
+		) -> Result<T::AccountId, DispatchError>;
+		fn account_for_location(location: &Location) -> Option<T::AccountId>;
+	}
 }