allow treasury to do reserve asset transfers

cumulus/parachains/integration-tests/emulated/common/src/constants.rs

@@ -15,16 +15,16 @@
 
 // Substrate
 use beefy_primitives::ecdsa_crypto::AuthorityId as BeefyId;
+use frame_support::PalletId;
 use grandpa::AuthorityId as GrandpaId;
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
 use sp_authority_discovery::AuthorityId as AuthorityDiscoveryId;
 use sp_consensus_babe::AuthorityId as BabeId;
 use sp_core::{sr25519, storage::Storage, Pair, Public};
 use sp_runtime::{
-	traits::{IdentifyAccount, Verify},
+	traits::{AccountIdConversion, IdentifyAccount, Verify},
 	BuildStorage, MultiSignature, Perbill,
 };
-
 // Cumulus
 use parachains_common::{AccountId, AssetHubPolkadotAuraId, AuraId, Balance, BlockNumber};
 use polkadot_primitives::{AssignmentId, ValidatorId};
@@ -70,6 +70,10 @@ pub mod accounts {
 	pub const FERDIE_STASH: &str = "Ferdie//stash";
 	pub const FERDIE_BEEFY: &str = "Ferdie//stash";
 
+	pub fn get_treasury_address() -> AccountId {
+		PalletId(*b"py/trsry").into_account_truncating()
+	}
+
 	pub fn init_balances() -> Vec<AccountId> {
 		vec![
 			get_account_id_from_seed::<sr25519::Public>(ALICE),
@@ -84,6 +88,7 @@ pub mod accounts {
 			get_account_id_from_seed::<sr25519::Public>(DAVE_STASH),
 			get_account_id_from_seed::<sr25519::Public>(EVE_STASH),
 			get_account_id_from_seed::<sr25519::Public>(FERDIE_STASH),
+			get_treasury_address(),
 		]
 	}
 }

polkadot/xcm/xcm-builder/src/lib.rs

@@ -34,8 +34,8 @@ pub use location_conversion::{
 	ChildParachainConvertsVia, DescribeAccountId32Terminal, DescribeAccountIdTerminal,
 	DescribeAccountKey20Terminal, DescribeAllTerminal, DescribeBodyTerminal, DescribeFamily,
 	DescribeLocation, DescribePalletTerminal, DescribeTerminus, GlobalConsensusConvertsFor,
-	GlobalConsensusParachainConvertsFor, HashedDescription, ParentIsPreset,
-	SiblingParachainConvertsVia,
+	GlobalConsensusParachainConvertsFor, HashedDescription, LocalTreasuryVoiceConvertsVia,
+	ParentIsPreset, SiblingParachainConvertsVia,
 };
 
 mod origin_conversion;

polkadot/xcm/xcm-builder/src/location_conversion.rs

@@ -84,6 +84,20 @@ impl DescribeLocation for DescribeAccountKey20Terminal {
 	}
 }
 
+/// Create a description of the remote treasury `location` if possible. No two locations should have
+/// the same descriptor.
+pub struct DescribeTreasuryVoiceTerminal;
+
+impl DescribeLocation for DescribeTreasuryVoiceTerminal {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, &l.interior) {
+			(0, X1(Plurality { id: BodyId::Treasury, part: BodyPart::Voice })) =>
+				Some(("Treasury").encode()),
+			_ => return None,
+		}
+	}
+}
+
 pub type DescribeAccountIdTerminal = (DescribeAccountId32Terminal, DescribeAccountKey20Terminal);
 
 pub struct DescribeBodyTerminal;
@@ -101,6 +115,7 @@ pub type DescribeAllTerminal = (
 	DescribePalletTerminal,
 	DescribeAccountId32Terminal,
 	DescribeAccountKey20Terminal,
+	DescribeTreasuryVoiceTerminal,
 	DescribeBodyTerminal,
 );
 
@@ -328,6 +343,25 @@ impl<Network: Get<Option<NetworkId>>, AccountId: From<[u8; 32]> + Into<[u8; 32]>
 	}
 }
 
+/// Returns specified `TreasuryAccount` as `AccountId32` if passed `location` matches Treasury plurality.
+pub struct LocalTreasuryVoiceConvertsVia<TreasuryAccount, AccountId>(
+	PhantomData<(TreasuryAccount, AccountId)>,
+);
+impl<TreasuryAccount: Get<AccountId>, AccountId: From<[u8; 32]> + Into<[u8; 32]> + Clone>
+	ConvertLocation<AccountId> for LocalTreasuryVoiceConvertsVia<TreasuryAccount, AccountId>
+{
+	fn convert_location(location: &MultiLocation) -> Option<AccountId> {
+		let id: [u8; 32] = match *location {
+			MultiLocation {
+				parents: 0,
+				interior: X1(Plurality { id: BodyId::Treasury, part: BodyPart::Voice }),
+			} => TreasuryAccount::get().into(),
+			_ => return None,
+		};
+		Some(id.into())
+	}
+}
+
 /// Conversion implementation which converts from a `[u8; 32]`-based `AccountId` into a
 /// `MultiLocation` consisting solely of a `AccountId32` junction with a fixed value for its
 /// network (provided by `Network`) and the `AccountId`'s `[u8; 32]` datum for the `id`.
@@ -446,6 +480,9 @@ mod tests {
 	pub type ForeignChainAliasAccount<AccountId> =
 		HashedDescription<AccountId, LegacyDescribeForeignChainAccount>;
 
+	pub type ForeignChainAliasTreasuryAccount<AccountId> =
+		HashedDescription<AccountId, DescribeFamily<DescribeTreasuryVoiceTerminal>>;
+
 	use frame_support::parameter_types;
 	use xcm::latest::Junction;
 
@@ -936,4 +973,22 @@ mod tests {
 		};
 		assert!(ForeignChainAliasAccount::<[u8; 32]>::convert_location(&mul).is_none());
 	}
+
+	#[test]
+	fn remote_account_convert_on_para_sending_relay_treasury() {
+		let location = MultiLocation {
+			parents: 1,
+			interior: X1(Plurality { id: BodyId::Treasury, part: BodyPart::Voice }),
+		};
+		let actual_description =
+			ForeignChainAliasTreasuryAccount::<[u8; 32]>::convert_location(&location).unwrap();
+
+		assert_eq!(
+			[
+				103, 157, 82, 57, 235, 216, 82, 162, 31, 148, 162, 21, 44, 34, 218, 173, 202, 123,
+				235, 14, 186, 214, 16, 211, 10, 13, 72, 194, 254, 71, 87, 96
+			],
+			actual_description
+		);
+	}
 }