Xcm trap assets ed

runtime/acala/src/lib.rs

@@ -103,6 +103,7 @@ pub use primitives::{
 	AuctionId, AuthoritysOriginId, Balance, BlockNumber, CurrencyId, DataProviderId, EraIndex, Hash, Moment, Nonce,
 	ReserveIdentifier, Share, Signature, TokenSymbol, TradingPair,
 };
+use runtime_common::AcalaDropAssets;
 pub use runtime_common::{
 	cent, dollar, microcent, millicent, EnsureRootOrAllGeneralCouncil, EnsureRootOrAllTechnicalCommittee,
 	EnsureRootOrHalfFinancialCouncil, EnsureRootOrHalfGeneralCouncil, EnsureRootOrHalfHomaCouncil,
@@ -1450,7 +1451,14 @@ impl xcm_executor::Config for XcmConfig {
 	type Weigher = FixedWeightBounds<UnitWeightCost, Call, MaxInstructions>;
 	type Trader = Trader;
 	type ResponseHandler = PolkadotXcm;
-	type AssetTrap = PolkadotXcm;
+	type AssetTrap = AcalaDropAssets<
+		PolkadotXcm,
+		ToTreasury,
+		CurrencyIdConvert,
+		GetNativeCurrencyId,
+		NativeTokenExistentialDeposit,
+		ExistentialDeposits,
+	>;
 	type AssetClaims = PolkadotXcm;
 	type SubscriptionService = PolkadotXcm;
 }

runtime/common/Cargo.toml

@@ -38,6 +38,10 @@ module-transaction-payment = { path = "../../modules/transaction-payment", defau
 module-nft = { path = "../../modules/nft", default-features = false }
 module-dex = { path = "../../modules/dex", default-features = false }
 
+xcm = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.12", default-features = false }
+xcm-executor = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.12", default-features = false }
+xcm-builder = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.12", default-features = false }
+
 [dev-dependencies]
 serde_json = "1.0.64"
 hex-literal = "0.3.1"
@@ -87,6 +91,10 @@ std = [
 	"module-transaction-payment/std",
 	"module-nft/std",
 	"module-dex/std",
+
+	"xcm/std",
+	"xcm-executor/std",
+	"xcm-builder/std",
 ]
 with-ethereum-compatibility = [
 	"module-evm/with-ethereum-compatibility",

runtime/common/src/lib.rs

@@ -21,6 +21,7 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use codec::{Decode, Encode, MaxEncodedLen};
+use frame_support::traits::Get;
 use frame_support::{
 	parameter_types,
 	traits::Contains,
@@ -49,6 +50,7 @@ mod homa;
 pub use homa::*;
 
 pub mod precompile;
+use orml_traits::GetByKey;
 pub use precompile::{
 	AllPrecompiles, DexPrecompile, MultiCurrencyPrecompile, NFTPrecompile, OraclePrecompile, ScheduleCallPrecompile,
 	StateRentPrecompile,
@@ -57,6 +59,10 @@ pub use primitives::{
 	currency::{TokenInfo, ACA, AUSD, BNC, DOT, KAR, KSM, KUSD, LDOT, LKSM, PHA, RENBTC, VSKSM},
 	AccountId,
 };
+use sp_std::{marker::PhantomData, prelude::*};
+pub use xcm::latest::prelude::*;
+pub use xcm_builder::TakeRevenue;
+pub use xcm_executor::{traits::DropAssets, Assets};
 
 pub type TimeStampedPrice = orml_oracle::TimestampedValue<Price, primitives::Moment>;
 
@@ -331,6 +337,73 @@ pub enum RelayChainSubAccountId {
 	HomaLite = 0,
 }
 
+/// `DropAssets` implementation support asset amount lower thant ED handled by `TakeRevenue`.
+///
+/// parameters type:
+/// - `NC`: native currency_id type.
+/// - `NB`: the ExistentialDeposit amount of native currency_id.
+/// - `GK`: the ExistentialDeposit amount of tokens.
+pub struct AcalaDropAssets<X, T, C, NC, NB, GK>(PhantomData<(X, T, C, NC, NB, GK)>);
+impl<X, T, C, NC, NB, GK> DropAssets for AcalaDropAssets<X, T, C, NC, NB, GK>
+where
+	X: DropAssets,
+	T: TakeRevenue,
+	C: Convert<MultiLocation, Option<CurrencyId>>,
+	NC: Get<CurrencyId>,
+	NB: Get<Balance>,
+	GK: GetByKey<CurrencyId, Balance>,
+{
+	fn drop_assets(origin: &MultiLocation, assets: Assets) -> Weight {
+		let multi_assets: Vec<MultiAsset> = assets.into();
+		let mut asset_traps: Vec<MultiAsset> = vec![];
+		for asset in multi_assets {
+			if let MultiAsset {
+				id: Concrete(location),
+				fun: Fungible(amount),
+			} = asset.clone()
+			{
+				let currency_id = C::convert(location);
+				// burn asset(do nothing here) if convert result is None
+				if let Some(currency_id) = currency_id {
+					let ed = ExistentialDepositsForDropAssets::<NC, NB, GK>::get(&currency_id);
+					if amount < ed {
+						T::take_revenue(asset);
+					} else {
+						asset_traps.push(asset);
+					}
+				}
+			}
+		}
+		if !asset_traps.is_empty() {
+			X::drop_assets(origin, asset_traps.into());
+		}
+		0
+	}
+}
+
+/// `ExistentialDeposit` for tokens, give priority to match native token, then handled by
+/// `ExistentialDeposits`.
+///
+/// parameters type:
+/// - `NC`: native currency_id type.
+/// - `NB`: the ExistentialDeposit amount of native currency_id.
+/// - `GK`: the ExistentialDeposit amount of tokens.
+pub struct ExistentialDepositsForDropAssets<NC, NB, GK>(PhantomData<(NC, NB, GK)>);
+impl<NC, NB, GK> ExistentialDepositsForDropAssets<NC, NB, GK>
+where
+	NC: Get<CurrencyId>,
+	NB: Get<Balance>,
+	GK: GetByKey<CurrencyId, Balance>,
+{
+	fn get(currency_id: &CurrencyId) -> Balance {
+		if currency_id == &NC::get() {
+			NB::get()
+		} else {
+			GK::get(currency_id)
+		}
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

runtime/integration-tests/src/relaychain/kusama_cross_chain_transfer.rs

@@ -23,7 +23,7 @@ use crate::setup::*;
 
 use frame_support::assert_ok;
 
-use karura_runtime::AssetRegistry;
+use karura_runtime::{AssetRegistry, KaruraTreasuryAccount};
 use module_asset_registry::AssetMetadata;
 use orml_traits::MultiCurrency;
 use xcm_emulator::TestExt;
@@ -475,3 +475,178 @@ fn test_asset_registry_module() {
 		);
 	});
 }
+
+#[test]
+fn trap_assets_larger_than_ed_works() {
+	TestNet::reset();
+
+	let mut kar_treasury_amount = 0;
+	let (ksm_asset_amount, kar_asset_amount) = (dollar(KSM), dollar(KAR));
+	let trader_weight_to_treasury: u128 = 96_000_000;
+
+	Karura::execute_with(|| {
+		assert_ok!(Tokens::deposit(KSM, &AccountId::from(DEFAULT), 100 * dollar(KSM)));
+		let _ = pallet_balances::Pallet::<Runtime>::deposit_creating(&AccountId::from(DEFAULT), 100 * dollar(KAR));
+
+		kar_treasury_amount = Currencies::free_balance(KAR, &KaruraTreasuryAccount::get());
+	});
+
+	let assets: MultiAsset = (Parent, ksm_asset_amount).into();
+	KusamaNet::execute_with(|| {
+		let xcm = vec![
+			WithdrawAsset(assets.clone().into()),
+			BuyExecution {
+				fees: assets,
+				weight_limit: Limited(dollar(KSM) as u64),
+			},
+			WithdrawAsset(
+				(
+					(Parent, X2(Parachain(2000), GeneralKey(KAR.encode()))),
+					kar_asset_amount,
+				)
+					.into(),
+			),
+		];
+		assert_ok!(pallet_xcm::Pallet::<kusama_runtime::Runtime>::send_xcm(
+			Here,
+			Parachain(2000).into(),
+			Xcm(xcm),
+		));
+	});
+	Karura::execute_with(|| {
+		assert!(System::events()
+			.iter()
+			.any(|r| matches!(r.event, Event::PolkadotXcm(pallet_xcm::Event::AssetsTrapped(_, _, _)))));
+
+		assert_eq!(
+			trader_weight_to_treasury,
+			Currencies::free_balance(KSM, &KaruraTreasuryAccount::get())
+		);
+		assert_eq!(
+			kar_treasury_amount,
+			Currencies::free_balance(KAR, &KaruraTreasuryAccount::get())
+		);
+	});
+}
+
+#[test]
+fn trap_assets_lower_than_ed_works() {
+	TestNet::reset();
+
+	let mut kar_treasury_amount = 0;
+	let (ksm_asset_amount, kar_asset_amount) = (cent(KSM) / 100, cent(KAR));
+
+	Karura::execute_with(|| {
+		assert_ok!(Tokens::deposit(KSM, &AccountId::from(DEFAULT), dollar(KSM)));
+		let _ = pallet_balances::Pallet::<Runtime>::deposit_creating(&AccountId::from(DEFAULT), dollar(KAR));
+		kar_treasury_amount = Currencies::free_balance(KAR, &KaruraTreasuryAccount::get());
+	});
+
+	let assets: MultiAsset = (Parent, ksm_asset_amount).into();
+	KusamaNet::execute_with(|| {
+		let xcm = vec![
+			WithdrawAsset(assets.clone().into()),
+			BuyExecution {
+				fees: assets,
+				weight_limit: Limited(dollar(KSM) as u64),
+			},
+			WithdrawAsset(
+				(
+					(Parent, X2(Parachain(2000), GeneralKey(KAR.encode()))),
+					kar_asset_amount,
+				)
+					.into(),
+			),
+			// two asset left in holding register, they both lower than ED, so goes to treasury.
+		];
+		assert_ok!(pallet_xcm::Pallet::<kusama_runtime::Runtime>::send_xcm(
+			Here,
+			Parachain(2000).into(),
+			Xcm(xcm),
+		));
+	});
+
+	Karura::execute_with(|| {
+		assert_eq!(
+			System::events()
+				.iter()
+				.find(|r| matches!(r.event, Event::PolkadotXcm(pallet_xcm::Event::AssetsTrapped(_, _, _)))),
+			None
+		);
+
+		assert_eq!(
+			ksm_asset_amount,
+			Currencies::free_balance(KSM, &KaruraTreasuryAccount::get())
+		);
+		assert_eq!(
+			kar_asset_amount,
+			Currencies::free_balance(KAR, &KaruraTreasuryAccount::get()) - kar_treasury_amount
+		);
+	});
+}
+
+#[test]
+fn sibling_trap_assets_works() {
+	TestNet::reset();
+
+	let mut kar_treasury_amount = 0;
+	let (bnc_asset_amount, kar_asset_amount) = (cent(BNC) / 10, cent(KAR));
+
+	fn sibling_account() -> AccountId {
+		use sp_runtime::traits::AccountIdConversion;
+		polkadot_parachain::primitives::Sibling::from(2001).into_account()
+	}
+
+	Karura::execute_with(|| {
+		assert_ok!(Tokens::deposit(BNC, &sibling_account(), dollar(BNC)));
+		let _ = pallet_balances::Pallet::<Runtime>::deposit_creating(&sibling_account(), dollar(KAR));
+		kar_treasury_amount = Currencies::free_balance(KAR, &KaruraTreasuryAccount::get());
+	});
+
+	Sibling::execute_with(|| {
+		let assets: MultiAsset = (
+			(Parent, X2(Parachain(2000), GeneralKey(KAR.encode()))),
+			kar_asset_amount,
+		)
+			.into();
+		let xcm = vec![
+			WithdrawAsset(assets.clone().into()),
+			BuyExecution {
+				fees: assets,
+				weight_limit: Unlimited,
+			},
+			WithdrawAsset(
+				(
+					(
+						Parent,
+						X2(Parachain(2001), GeneralKey(parachains::bifrost::BNC_KEY.to_vec())),
+					),
+					bnc_asset_amount,
+				)
+					.into(),
+			),
+		];
+		assert_ok!(pallet_xcm::Pallet::<Runtime>::send_xcm(
+			Here,
+			(Parent, Parachain(2000)),
+			Xcm(xcm),
+		));
+	});
+
+	Karura::execute_with(|| {
+		assert_eq!(
+			System::events()
+				.iter()
+				.find(|r| matches!(r.event, Event::PolkadotXcm(pallet_xcm::Event::AssetsTrapped(_, _, _)))),
+			None
+		);
+		assert_eq!(
+			Currencies::free_balance(KAR, &KaruraTreasuryAccount::get()) - kar_treasury_amount,
+			kar_asset_amount
+		);
+		assert_eq!(
+			Currencies::free_balance(BNC, &KaruraTreasuryAccount::get()),
+			bnc_asset_amount
+		);
+	});
+}

runtime/integration-tests/src/setup.rs

@@ -150,6 +150,7 @@ const ORACLE3: [u8; 32] = [2u8; 32];
 const ORACLE4: [u8; 32] = [3u8; 32];
 const ORACLE5: [u8; 32] = [4u8; 32];
 
+pub const DEFAULT: [u8; 32] = [0u8; 32];
 pub const ALICE: [u8; 32] = [4u8; 32];
 pub const BOB: [u8; 32] = [5u8; 32];
 pub const CHARLIE: [u8; 32] = [6u8; 32];

runtime/karura/src/lib.rs

@@ -104,6 +104,7 @@ pub use primitives::{
 	AuctionId, AuthoritysOriginId, Balance, BlockNumber, CurrencyId, DataProviderId, EraIndex, Hash, Moment, Nonce,
 	ReserveIdentifier, Share, Signature, TokenSymbol, TradingPair,
 };
+use runtime_common::AcalaDropAssets;
 pub use runtime_common::{
 	cent, dollar, microcent, millicent, EnsureRootOrAllGeneralCouncil, EnsureRootOrAllTechnicalCommittee,
 	EnsureRootOrHalfFinancialCouncil, EnsureRootOrHalfGeneralCouncil, EnsureRootOrHalfHomaCouncil,
@@ -1513,7 +1514,14 @@ impl xcm_executor::Config for XcmConfig {
 	type Weigher = FixedWeightBounds<UnitWeightCost, Call, MaxInstructions>;
 	type Trader = Trader;
 	type ResponseHandler = PolkadotXcm;
-	type AssetTrap = PolkadotXcm;
+	type AssetTrap = AcalaDropAssets<
+		PolkadotXcm,
+		ToTreasury,
+		CurrencyIdConvert,
+		GetNativeCurrencyId,
+		NativeTokenExistentialDeposit,
+		ExistentialDeposits,
+	>;
 	type AssetClaims = PolkadotXcm;
 	type SubscriptionService = PolkadotXcm;
 }