Contracts expose pallet-xcm (#1248)

This PR introduces: - XCM host functions `xcm_send`, `xcm_execute` - An Xcm trait into the config. that proxy these functions to to `pallet_xcm`, or disable their usage by using `()`. - A mock_network and xcm_test files to test the newly added xcm-related functions. --------- Co-authored-by: Keith Yeung <kungfukeith11@gmail.com> Co-authored-by: Sasha Gryaznov <hi@agryaznov.com> Co-authored-by: command-bot <> Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com> Co-authored-by: Alexander Theißen <alex.theissen@me.com>
2026-05-30 16:21:02 +00:00 · 2023-11-14 21:32:14 +01:00
parent fc12f435e3
commit f517900a48
23 changed files with 1797 additions and 15 deletions
@@ -0,0 +1,168 @@
+// Copyright Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Parachain runtime mock.
+
+use codec::{Decode, Encode};
+
+use frame_support::weights::Weight;
+use polkadot_parachain_primitives::primitives::{
+	DmpMessageHandler, Id as ParaId, XcmpMessageFormat, XcmpMessageHandler,
+};
+use polkadot_primitives::BlockNumber as RelayBlockNumber;
+use sp_runtime::traits::{Get, Hash};
+
+use sp_std::prelude::*;
+use xcm::{latest::prelude::*, VersionedXcm};
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+	use frame_support::pallet_prelude::*;
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+		type XcmExecutor: ExecuteXcm<Self::RuntimeCall>;
+	}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {}
+
+	#[pallet::pallet]
+	#[pallet::without_storage_info]
+	pub struct Pallet<T>(_);
+
+	#[pallet::storage]
+	#[pallet::getter(fn parachain_id)]
+	pub(super) type ParachainId<T: Config> = StorageValue<_, ParaId, ValueQuery>;
+
+	#[pallet::storage]
+	#[pallet::getter(fn received_dmp)]
+	/// A queue of received DMP messages
+	pub(super) type ReceivedDmp<T: Config> = StorageValue<_, Vec<Xcm<T::RuntimeCall>>, ValueQuery>;
+
+	impl<T: Config> Get<ParaId> for Pallet<T> {
+		fn get() -> ParaId {
+			Self::parachain_id()
+		}
+	}
+
+	pub type MessageId = [u8; 32];
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		/// Some XCM was executed OK.
+		Success(Option<T::Hash>),
+		/// Some XCM failed.
+		Fail(Option<T::Hash>, XcmError),
+		/// Bad XCM version used.
+		BadVersion(Option<T::Hash>),
+		/// Bad XCM format used.
+		BadFormat(Option<T::Hash>),
+
+		// DMP
+		/// Downward message is invalid XCM.
+		InvalidFormat(MessageId),
+		/// Downward message is unsupported version of XCM.
+		UnsupportedVersion(MessageId),
+		/// Downward message executed with the given outcome.
+		ExecutedDownward(MessageId, Outcome),
+	}
+
+	impl<T: Config> Pallet<T> {
+		pub fn set_para_id(para_id: ParaId) {
+			ParachainId::<T>::put(para_id);
+		}
+
+		fn handle_xcmp_message(
+			sender: ParaId,
+			_sent_at: RelayBlockNumber,
+			xcm: VersionedXcm<T::RuntimeCall>,
+			max_weight: Weight,
+		) -> Result<Weight, XcmError> {
+			let hash = Encode::using_encoded(&xcm, T::Hashing::hash);
+			let message_hash = Encode::using_encoded(&xcm, sp_io::hashing::blake2_256);
+			let (result, event) = match Xcm::<T::RuntimeCall>::try_from(xcm) {
+				Ok(xcm) => {
+					let location = (Parent, Parachain(sender.into()));
+					match T::XcmExecutor::execute_xcm(location, xcm, message_hash, max_weight) {
+						Outcome::Error(e) => (Err(e), Event::Fail(Some(hash), e)),
+						Outcome::Complete(w) => (Ok(w), Event::Success(Some(hash))),
+						// As far as the caller is concerned, this was dispatched without error, so
+						// we just report the weight used.
+						Outcome::Incomplete(w, e) => (Ok(w), Event::Fail(Some(hash), e)),
+					}
+				},
+				Err(()) => (Err(XcmError::UnhandledXcmVersion), Event::BadVersion(Some(hash))),
+			};
+			Self::deposit_event(event);
+			result
+		}
+	}
+
+	impl<T: Config> XcmpMessageHandler for Pallet<T> {
+		fn handle_xcmp_messages<'a, I: Iterator<Item = (ParaId, RelayBlockNumber, &'a [u8])>>(
+			iter: I,
+			max_weight: Weight,
+		) -> Weight {
+			for (sender, sent_at, data) in iter {
+				let mut data_ref = data;
+				let _ = XcmpMessageFormat::decode(&mut data_ref)
+					.expect("Simulator encodes with versioned xcm format; qed");
+
+				let mut remaining_fragments = data_ref;
+				while !remaining_fragments.is_empty() {
+					if let Ok(xcm) =
+						VersionedXcm::<T::RuntimeCall>::decode(&mut remaining_fragments)
+					{
+						let _ = Self::handle_xcmp_message(sender, sent_at, xcm, max_weight);
+					} else {
+						debug_assert!(false, "Invalid incoming XCMP message data");
+					}
+				}
+			}
+			max_weight
+		}
+	}
+
+	impl<T: Config> DmpMessageHandler for Pallet<T> {
+		fn handle_dmp_messages(
+			iter: impl Iterator<Item = (RelayBlockNumber, Vec<u8>)>,
+			limit: Weight,
+		) -> Weight {
+			for (_i, (_sent_at, data)) in iter.enumerate() {
+				let id = sp_io::hashing::blake2_256(&data[..]);
+				let maybe_versioned = VersionedXcm::<T::RuntimeCall>::decode(&mut &data[..]);
+				match maybe_versioned {
+					Err(_) => {
+						Self::deposit_event(Event::InvalidFormat(id));
+					},
+					Ok(versioned) => match Xcm::try_from(versioned) {
+						Err(()) => Self::deposit_event(Event::UnsupportedVersion(id)),
+						Ok(x) => {
+							let outcome = T::XcmExecutor::execute_xcm(Parent, x.clone(), id, limit);
+							<ReceivedDmp<T>>::append(x);
+							Self::deposit_event(Event::ExecutedDownward(id, outcome));
+						},
+					},
+				}
+			}
+			limit
+		}
+	}
+}
@@ -0,0 +1,52 @@
+// Copyright Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use frame_support::{parameter_types, weights::Weight};
+use xcm::latest::prelude::*;
+use xcm_simulator::{
+	AggregateMessageOrigin, ProcessMessage, ProcessMessageError, UmpQueueId, WeightMeter,
+};
+
+use crate::relay_chain::{RuntimeCall, XcmConfig};
+
+parameter_types! {
+	/// Amount of weight that can be spent per block to service messages.
+	pub MessageQueueServiceWeight: Weight = Weight::from_parts(1_000_000_000, 1_000_000);
+	pub const MessageQueueHeapSize: u32 = 65_536;
+	pub const MessageQueueMaxStale: u32 = 16;
+}
+
+/// Message processor to handle any messages that were enqueued into the `MessageQueue` pallet.
+pub struct MessageProcessor;
+impl ProcessMessage for MessageProcessor {
+	type Origin = AggregateMessageOrigin;
+
+	fn process_message(
+		message: &[u8],
+		origin: Self::Origin,
+		meter: &mut WeightMeter,
+		id: &mut [u8; 32],
+	) -> Result<bool, ProcessMessageError> {
+		let para = match origin {
+			AggregateMessageOrigin::Ump(UmpQueueId::Para(para)) => para,
+		};
+		xcm_builder::ProcessXcmMessage::<
+			Junction,
+			xcm_executor::XcmExecutor<XcmConfig>,
+			RuntimeCall,
+		>::process_message(message, Junction::Parachain(para.into()), meter, id)
+	}
+}