Collectives: teleport slashed assets

parachains/common/src/impls.rs

@@ -49,23 +49,6 @@ where
 	}
 }
 
-/*
-TODO:COLLECTIVES
-
-pub struct ToParentTreasury<R>(PhantomData<R>);
-impl<R> OnUnbalanced<NegativeImbalance<R>> for ToParentTreasury<R>
-where
-	R: pallet_balances::Config,
-	AccountIdOf<R>:
-		From<polkadot_primitives::v2::AccountId> + Into<polkadot_primitives::v2::AccountId>,
-	<R as frame_system::Config>::Event: From<pallet_balances::Event<R>>,
-{
-	fn on_unbalanced(amount: NegativeImbalance<R>) {
-		polkadot_xcm::Pallet::<R>::teleport();
-	}
-}
-*/
-
 /// Implementation of `OnUnbalanced` that deals with the fees by combining tip and fee and passing
 /// the result on to `ToStakingPot`.
 pub struct DealWithFees<R>(PhantomData<R>);

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

@@ -13,6 +13,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+pub mod account {
+	use frame_support::PalletId;
+	use sp_runtime::AccountId32;
+
+	/// Relay Chain treasury pallet id, used to convert into AccountId
+	pub const RELAY_TREASURY_PALL_ID: PalletId = PalletId(*b"py/trsry");
+	/// account used to temporarily deposit slashed imbalance before teleporting
+	pub const SLASHED_IMBALANCE_ACC_ID: AccountId32 = AccountId32::new([7u8; 32]);
+}
+
 pub mod currency {
 	use polkadot_core_primitives::Balance;
 	use polkadot_runtime_constants as constants;

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

@@ -0,0 +1,73 @@
+// Copyright (C) 2021 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use frame_support::{
+	log,
+	traits::{Currency, Get, Imbalance, OnUnbalanced, OriginTrait},
+};
+use sp_std::{boxed::Box, marker::PhantomData};
+use xcm::latest::{Fungibility, Junction, NetworkId, Parent};
+
+type AccountIdOf<T> = <T as frame_system::Config>::AccountId;
+
+type NegativeImbalanceOf<T, I> = <<T as pallet_alliance::Config<I>>::Currency as Currency<
+	<T as frame_system::Config>::AccountId,
+>>::NegativeImbalance;
+
+type CurrencyOf<T, I> = <T as pallet_alliance::Config<I>>::Currency;
+
+type BalanceOf<T, I> = <<T as pallet_alliance::Config<I>>::Currency as Currency<
+	<T as frame_system::Config>::AccountId,
+>>::Balance;
+
+pub struct ToParentTreasury<TreasuryAcc, TempAcc, T, I = ()>(
+	PhantomData<(TreasuryAcc, TempAcc, T, I)>,
+);
+
+impl<TreasuryAcc, TempAcc, T, I: 'static> OnUnbalanced<NegativeImbalanceOf<T, I>>
+	for ToParentTreasury<TreasuryAcc, TempAcc, T, I>
+where
+	TreasuryAcc: Get<AccountIdOf<T>>,
+	TempAcc: Get<AccountIdOf<T>>,
+	T: pallet_xcm::Config + frame_system::Config + pallet_alliance::Config<I>,
+	[u8; 32]: From<AccountIdOf<T>>,
+	BalanceOf<T, I>: Into<Fungibility>,
+	<<T as frame_system::Config>::Origin as OriginTrait>::AccountId: From<AccountIdOf<T>>,
+{
+	fn on_unbalanced(amount: NegativeImbalanceOf<T, I>) {
+		let temp_account: AccountIdOf<T> = TempAcc::get();
+		let treasury_acc: AccountIdOf<T> = TreasuryAcc::get();
+		let imbalance = amount.peek();
+
+		<CurrencyOf<T, I>>::resolve_creating(&temp_account, amount);
+
+		let result = pallet_xcm::Pallet::<T>::teleport_assets(
+			<T as frame_system::Config>::Origin::signed(temp_account.into()),
+			Box::new(Parent.into()),
+			Box::new(
+				Junction::AccountId32 { network: NetworkId::Any, id: treasury_acc.into() }
+					.into()
+					.into(),
+			),
+			Box::new((Parent, imbalance).into()),
+			0,
+		);
+
+		match result {
+			Err(err) => log::warn!("Failed to teleport slashed assets: {:?}", err),
+			_ => (),
+		};
+	}
+}

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

@@ -38,15 +38,17 @@
 include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
 
 pub mod constants;
+pub mod impls;
 mod weights;
 pub mod xcm_config;
 
 use cumulus_pallet_parachain_system::RelayNumberStrictlyIncreases;
+use impls::ToParentTreasury;
 use sp_api::impl_runtime_apis;
 use sp_core::{crypto::KeyTypeId, OpaqueMetadata};
 use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
-	traits::{AccountIdLookup, BlakeTwo256, Block as BlockT},
+	traits::{AccountIdConversion, AccountIdLookup, BlakeTwo256, Block as BlockT},
 	transaction_validity::{TransactionSource, TransactionValidity},
 	ApplyExtrinsicResult,
 };
@@ -482,6 +484,9 @@ pub const MAX_ALLIES: u32 = 100;
 
 parameter_types! {
 	pub const AllyDeposit: Balance = 1_000 * UNITS; // 1,000 DOT bond to join as an Ally
+	// account used to temporarily deposit slashed imbalance before teleporting
+	pub SlashedImbalanceAccId: AccountId = constants::account::SLASHED_IMBALANCE_ACC_ID.into();
+	pub RelayTreasuryAccId: AccountId = constants::account::RELAY_TREASURY_PALL_ID.into_account_truncating();
 }
 
 impl pallet_alliance::Config for Runtime {
@@ -500,7 +505,7 @@ impl pallet_alliance::Config for Runtime {
 		pallet_collective::EnsureProportionMoreThan<AccountId, AllianceCollective, 2, 3>,
 	>;
 	type Currency = Balances;
-	type Slashed = (); // TODO:COLLECTIVES add handler to send teleport to Relay Treasury
+	type Slashed = ToParentTreasury<RelayTreasuryAccId, SlashedImbalanceAccId, Runtime>;
 	type InitializeMembers = AllianceMotion;
 	type MembershipChanged = AllianceMotion;
 	type IdentityVerifier = (); // Don't block accounts on identity criteria