[Feature] Limit collectives teleports to DOT

parachains/common/src/xcm_config.rs

@@ -5,8 +5,9 @@ use frame_support::{
 	traits::{fungibles::Inspect, tokens::BalanceConversion},
 	weights::{Weight, WeightToFee, WeightToFeePolynomial},
 };
+use sp_runtime::traits::Get;
 use xcm::latest::prelude::*;
-use xcm_executor::traits::ShouldExecute;
+use xcm_executor::traits::{FilterAssetLocation, ShouldExecute};
 
 //TODO: move DenyThenTry to polkadot's xcm module.
 /// Deny executing the XCM if it matches any of the Deny filter regardless of anything else.
@@ -107,3 +108,14 @@ where
 		Ok(asset_amount)
 	}
 }
+
+/// Accepts an asset if it is a native asset from a particular `MultiLocation`.
+pub struct ConcreteNativeAssetFrom<Location>(PhantomData<Location>);
+impl<Location: Get<MultiLocation>> FilterAssetLocation for ConcreteNativeAssetFrom<Location> {
+	fn filter_asset_location(asset: &MultiAsset, origin: &MultiLocation) -> bool {
+		log::trace!(target: "xcm::filter_asset_location",
+			"ConcreteNativeAsset asset: {:?}, origin: {:?}, location: {:?}",
+			asset, origin, Location::get());
+		matches!(asset.id, Concrete(ref id) if id == origin && origin == &Location::get())
+	}
+}

parachains/runtimes/collectives/collectives-polkadot/src/xcm_config.rs

@@ -25,15 +25,15 @@ use frame_support::{
 use pallet_xcm::XcmPassthrough;
 use parachains_common::{
 	impls::ToStakingPot,
-	xcm_config::{DenyReserveTransferToRelayChain, DenyThenTry},
+	xcm_config::{ConcreteNativeAssetFrom, DenyReserveTransferToRelayChain, DenyThenTry},
 };
 use polkadot_parachain::primitives::Sibling;
 use xcm::latest::prelude::*;
 use xcm_builder::{
 	AccountId32Aliases, AllowKnownQueryResponses, AllowSubscriptionsFrom,
 	AllowTopLevelPaidExecutionFrom, AllowUnpaidExecutionFrom, CurrencyAdapter, EnsureXcmOrigin,
-	FixedWeightBounds, IsConcrete, LocationInverter, NativeAsset, ParentAsSuperuser,
-	ParentIsPreset, RelayChainAsNative, SiblingParachainAsNative, SiblingParachainConvertsVia,
+	FixedWeightBounds, IsConcrete, LocationInverter, ParentAsSuperuser, ParentIsPreset,
+	RelayChainAsNative, SiblingParachainAsNative, SiblingParachainConvertsVia,
 	SignedAccountId32AsNative, SignedToAccountId32, SovereignSignedViaLocation, TakeWeightCredit,
 	UsingComponents,
 };
@@ -140,7 +140,8 @@ impl xcm_executor::Config for XcmConfig {
 	// Collectives does not recognize a reserve location for any asset. Users must teleport DOT
 	// where allowed (e.g. with the Relay Chain).
 	type IsReserve = ();
-	type IsTeleporter = NativeAsset; // <- should be enough to allow teleportation of DOT
+	/// Only allow teleportation of DOT.
+	type IsTeleporter = ConcreteNativeAssetFrom<DotLocation>;
 	type LocationInverter = LocationInverter<Ancestry>;
 	type Barrier = Barrier;
 	type Weigher = FixedWeightBounds<UnitWeightCost, Call, MaxInstructions>;