Add orml-xcm module. (#539)

* Add Xcm module.

* Remove unused deps.

* Make clippy happy.

* Add unit tests for orml-xcm.

Author: shaunxw

Cargo.dev.toml

@@ -17,6 +17,7 @@ members = [
 	"vesting",
 	"rewards",
 	"nft",
+	"xcm",
 	"xtokens",
 	"xcm-support",
 	"unknown-tokens",
@@ -92,6 +93,7 @@ parachain-info = { git = "https://github.com/paritytech//cumulus", rev = "c5c3ab
 xcm = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
 xcm-executor = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
 xcm-builder = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
+pallet-xcm = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
 polkadot-core-primitives = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
 polkadot-runtime-parachains = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }
 polkadot-parachain = { git = "https://github.com/paritytech//polkadot", rev = "5d35bac7408a4cb12a578764217d06f3920b36aa" }

xcm/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "orml-xcm"
+description = "XCM message helpers."
+repository = "https://github.com/open-web3-stack/open-runtime-module-library/tree/master/xcm"
+license = "Apache-2.0"
+version = "0.4.1-dev"
+authors = ["Acala Developers"]
+edition = "2018"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "2.0.0", default-features = false }
+
+frame-support = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.7", default-features = false }
+frame-system = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.7", default-features = false }
+
+xcm = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.7", default-features = false }
+pallet-xcm = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.7", default-features = false }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"xcm/std",
+	"pallet-xcm/std",
+]
+try-runtime = ["frame-support/try-runtime"]

xcm/src/lib.rs

@@ -0,0 +1,63 @@
+//! # Xcm Module
+
+#![cfg_attr(not(feature = "std"), no_std)]
+#![allow(clippy::large_enum_variant)]
+
+use frame_support::{pallet_prelude::*, traits::EnsureOrigin};
+use frame_system::pallet_prelude::*;
+
+use xcm::v0::prelude::*;
+
+pub use module::*;
+
+#[frame_support::pallet]
+pub mod module {
+	use super::*;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config + pallet_xcm::Config {
+		type Event: From<Event<Self>> + IsType<<Self as frame_system::Config>::Event>;
+
+		/// The required origin for sending XCM as parachain sovereign.
+		///
+		/// Typically root or the majority of collective.
+		type SovereignOrigin: EnsureOrigin<Self::Origin>;
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		/// XCM message sent. \[from, to, message\]
+		Sent(MultiLocation, MultiLocation, Xcm<()>),
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		/// The message and destination combination was not recognized as being
+		/// reachable.
+		Unreachable,
+		/// The message and destination was recognized as being reachable but
+		/// the operation could not be completed.
+		SendFailure,
+	}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		/// Send an XCM message as parachain sovereign.
+		#[pallet::weight(100_000_000)]
+		pub fn send_as_sovereign(origin: OriginFor<T>, dest: MultiLocation, message: Xcm<()>) -> DispatchResult {
+			let _ = T::SovereignOrigin::ensure_origin(origin)?;
+			pallet_xcm::Pallet::<T>::send_xcm(MultiLocation::Null, dest.clone(), message.clone()).map_err(
+				|e| match e {
+					XcmError::CannotReachDestination(..) => Error::<T>::Unreachable,
+					_ => Error::<T>::SendFailure,
+				},
+			)?;
+			Self::deposit_event(Event::Sent(MultiLocation::Null, dest, message));
+			Ok(())
+		}
+	}
+}

xtokens/Cargo.toml

@@ -45,6 +45,7 @@ pallet-xcm = { git = "https://github.com/paritytech/polkadot", branch = "release
 polkadot-runtime-parachains = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.7" }
 
 orml-tokens = { path = "../tokens" }
+orml-xcm = { path = "../xcm" }
 xcm-simulator = { git = "https://github.com/shaunxw/xcm-simulator.git", branch = "polkadot-v0.9.7"}
 
 [features]

xtokens/src/mock/para.rs

@@ -231,6 +231,11 @@ impl orml_xtokens::Config for Runtime {
 	type BaseXcmWeight = BaseXcmWeight;
 }
 
+impl orml_xcm::Config for Runtime {
+	type Event = Event;
+	type SovereignOrigin = EnsureRoot<AccountId>;
+}
+
 type UncheckedExtrinsic = frame_system::mocking::MockUncheckedExtrinsic<Runtime>;
 type Block = frame_system::mocking::MockBlock<Runtime>;
 
@@ -252,5 +257,6 @@ construct_runtime!(
 		XTokens: orml_xtokens::{Pallet, Storage, Call, Event<T>},
 
 		PolkadotXcm: pallet_xcm::{Pallet, Call, Event<T>, Origin},
+		OrmlXcm: orml_xcm::{Pallet, Call, Event<T>},
 	}
 );

xtokens/src/tests.rs

@@ -1,14 +1,15 @@
 #![cfg(test)]
 
 use super::*;
+use codec::Encode;
 use cumulus_primitives_core::ParaId;
-use frame_support::{assert_noop, assert_ok, traits::Currency};
+use frame_support::{assert_err, assert_noop, assert_ok, traits::Currency};
 use mock::*;
 use orml_traits::MultiCurrency;
 // use polkadot_parachain::primitives::{AccountIdConversion, Sibling};
 use polkadot_parachain::primitives::AccountIdConversion;
 use sp_runtime::AccountId32;
-use xcm::v0::{Junction, NetworkId};
+use xcm::v0::{Junction, NetworkId, Order};
 use xcm_simulator::TestExt;
 
 fn para_a_account() -> AccountId32 {
@@ -325,3 +326,88 @@ fn transfer_to_invalid_dest_fails() {
 		);
 	});
 }
+
+#[test]
+fn send_as_sovereign() {
+	TestNet::reset();
+
+	Relay::execute_with(|| {
+		let _ = RelayBalances::deposit_creating(&para_a_account(), 1_000_000_000_000);
+	});
+
+	ParaA::execute_with(|| {
+		use xcm::v0::OriginKind::SovereignAccount;
+
+		let call = relay::Call::System(frame_system::Call::<relay::Runtime>::remark_with_event(vec![1, 1, 1]));
+		assert_ok!(para::OrmlXcm::send_as_sovereign(
+			para::Origin::root(),
+			Junction::Parent.into(),
+			WithdrawAsset {
+				assets: vec![MultiAsset::ConcreteFungible {
+					id: MultiLocation::Null,
+					amount: 1_000_000_000_000
+				}],
+				effects: vec![Order::BuyExecution {
+					fees: MultiAsset::All,
+					weight: 10_000_000,
+					debt: 10_000_000,
+					halt_on_error: true,
+					xcm: vec![Transact {
+						origin_type: SovereignAccount,
+						require_weight_at_most: 1_000_000_000,
+						call: call.encode().into(),
+					}],
+				}]
+			}
+		));
+	});
+
+	Relay::execute_with(|| {
+		relay::System::events().iter().any(|r| {
+			if let relay::Event::System(frame_system::Event::<relay::Runtime>::Remarked(_, _)) = r.event {
+				true
+			} else {
+				false
+			}
+		});
+	})
+}
+
+#[test]
+fn send_as_sovereign_fails_if_bad_origin() {
+	TestNet::reset();
+
+	Relay::execute_with(|| {
+		let _ = RelayBalances::deposit_creating(&para_a_account(), 1_000_000_000_000);
+	});
+
+	ParaA::execute_with(|| {
+		use xcm::v0::OriginKind::SovereignAccount;
+
+		let call = relay::Call::System(frame_system::Call::<relay::Runtime>::remark_with_event(vec![1, 1, 1]));
+		assert_err!(
+			para::OrmlXcm::send_as_sovereign(
+				para::Origin::signed(ALICE),
+				Junction::Parent.into(),
+				WithdrawAsset {
+					assets: vec![MultiAsset::ConcreteFungible {
+						id: MultiLocation::Null,
+						amount: 1_000_000_000_000
+					}],
+					effects: vec![Order::BuyExecution {
+						fees: MultiAsset::All,
+						weight: 10_000_000,
+						debt: 10_000_000,
+						halt_on_error: true,
+						xcm: vec![Transact {
+							origin_type: SovereignAccount,
+							require_weight_at_most: 1_000_000_000,
+							call: call.encode().into(),
+						}],
+					}]
+				}
+			),
+			DispatchError::BadOrigin,
+		);
+	});
+}