Enhance dispatch module (#121)

modules/dispatch/src/lib.rs

@@ -25,7 +25,9 @@
 // Generated by `decl_event!`
 #![allow(clippy::unused_unit)]
 
-use bp_message_dispatch::{CallOrigin, MessageDispatch, MessagePayload, SpecVersion};
+use bp_message_dispatch::{
+	CallFilter, CallOrigin, IntoDispatchOrigin, MessageDispatch, MessagePayload, SpecVersion,
+};
 use bp_runtime::{
 	derive_account_id,
 	messages::{DispatchFeePayment, MessageDispatchResult},
@@ -35,7 +37,7 @@ use codec::Encode;
 use frame_support::{
 	dispatch::Dispatchable,
 	ensure,
-	traits::{Contains, Get},
+	traits::Get,
 	weights::{extract_actual_weight, GetDispatchInfo},
 };
 use frame_system::RawOrigin;
@@ -81,7 +83,7 @@ pub mod pallet {
 		///
 		/// The pallet will filter all incoming calls right before they're dispatched. If this
 		/// filter rejects the call, special event (`Event::MessageCallRejected`) is emitted.
-		type CallFilter: Contains<<Self as Config<I>>::Call>;
+		type CallFilter: CallFilter<Self::Origin, <Self as Config<I>>::Call>;
 		/// The type that is used to wrap the `Self::Call` when it is moved over bridge.
 		///
 		/// The idea behind this is to avoid `Call` conversion/decoding until we'll be sure
@@ -93,6 +95,12 @@ pub mod pallet {
 		///
 		/// Used when deriving target chain AccountIds from source chain AccountIds.
 		type AccountIdConverter: sp_runtime::traits::Convert<sp_core::hash::H256, Self::AccountId>;
+		/// The type is used to customize the dispatch call origin.
+		type IntoDispatchOrigin: IntoDispatchOrigin<
+			Self::AccountId,
+			<Self as Config<I>>::Call,
+			Self::Origin,
+		>;
 	}
 
 	type BridgeMessageIdOf<T, I> = <T as Config<I>>::BridgeMessageId;
@@ -138,7 +146,9 @@ pub mod pallet {
 	}
 }
 
-impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId> for Pallet<T, I> {
+impl<T: Config<I>, I: 'static>
+	MessageDispatch<T::Origin, T::BridgeMessageId, <T as pallet::Config<I>>::Call> for Pallet<T, I>
+{
 	type Message = MessagePayload<
 		T::SourceChainAccountId,
 		T::TargetChainAccountPublic,
@@ -150,7 +160,7 @@ impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId>
 		message.weight
 	}
 
-	fn dispatch<P: FnOnce(&T::AccountId, bp_message_dispatch::Weight) -> Result<(), ()>>(
+	fn dispatch<P: FnOnce(&T::Origin, &<T as pallet::Config<I>>::Call) -> Result<(), ()>>(
 		source_chain: ChainId,
 		target_chain: ChainId,
 		id: T::BridgeMessageId,
@@ -217,7 +227,7 @@ impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId>
 		};
 
 		// prepare dispatch origin
-		let origin_account = match message.origin {
+		let origin_derived_account = match message.origin {
 			CallOrigin::SourceRoot => {
 				let hex_id =
 					derive_account_id::<T::SourceChainAccountId>(source_chain, SourceAccount::Root);
@@ -260,8 +270,12 @@ impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId>
 			},
 		};
 
+		// generate dispatch origin from origin account
+		let dispatch_origin =
+			T::IntoDispatchOrigin::into_dispatch_origin(&origin_derived_account, &call);
+
 		// filter the call
-		if !T::CallFilter::contains(&call) {
+		if !T::CallFilter::contains(&dispatch_origin, &call) {
 			log::trace!(
 				target: "runtime::bridge-dispatch",
 				"Message {:?}/{:?}: the call ({:?}) is rejected by filter",
@@ -299,9 +313,7 @@ impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId>
 		// pay dispatch fee right before dispatch
 		let pay_dispatch_fee_at_target_chain =
 			message.dispatch_fee_payment == DispatchFeePayment::AtTargetChain;
-		if pay_dispatch_fee_at_target_chain
-			&& pay_dispatch_fee(&origin_account, message.weight).is_err()
-		{
+		if pay_dispatch_fee_at_target_chain && pay_dispatch_fee(&dispatch_origin, &call).is_err() {
 			log::trace!(
 				target: "runtime::bridge-dispatch",
 				"Failed to pay dispatch fee for dispatching message {:?}/{:?} with weight {}",
@@ -312,18 +324,15 @@ impl<T: Config<I>, I: 'static> MessageDispatch<T::AccountId, T::BridgeMessageId>
 			Self::deposit_event(Event::MessageDispatchPaymentFailed(
 				source_chain,
 				id,
-				origin_account,
+				origin_derived_account,
 				message.weight,
 			));
 			return dispatch_result;
 		}
 		dispatch_result.dispatch_fee_paid_during_dispatch = pay_dispatch_fee_at_target_chain;
 
-		// finally dispatch message
-		let origin = RawOrigin::Signed(origin_account).into();
-
 		log::trace!(target: "runtime::bridge-dispatch", "Message being dispatched is: {:.4096?}", &call);
-		let result = call.dispatch(origin);
+		let result = call.dispatch(dispatch_origin);
 		let actual_call_weight = extract_actual_weight(&result, &dispatch_info);
 		dispatch_result.dispatch_result = result.is_ok();
 		dispatch_result.unspent_weight = message.weight.saturating_sub(actual_call_weight);
@@ -529,6 +538,7 @@ mod tests {
 		type CallFilter = TestCallFilter;
 		type EncodedCall = EncodedCall;
 		type Event = Event;
+		type IntoDispatchOrigin = TestIntoDispatchOrigin;
 		type SourceChainAccountId = AccountId;
 		type TargetChainAccountPublic = TestAccountPublic;
 		type TargetChainSignature = TestSignature;
@@ -545,12 +555,20 @@ mod tests {
 
 	pub struct TestCallFilter;
 
-	impl Contains<Call> for TestCallFilter {
-		fn contains(call: &Call) -> bool {
+	impl CallFilter<Origin, Call> for TestCallFilter {
+		fn contains(_origin: &Origin, call: &Call) -> bool {
 			!matches!(*call, Call::System(frame_system::Call::fill_block { .. }))
 		}
 	}
 
+	pub struct TestIntoDispatchOrigin;
+
+	impl IntoDispatchOrigin<AccountId, Call, Origin> for TestIntoDispatchOrigin {
+		fn into_dispatch_origin(id: &AccountId, _call: &Call) -> Origin {
+			frame_system::RawOrigin::Signed(*id).into()
+		}
+	}
+
 	const TEST_SPEC_VERSION: SpecVersion = 0;
 	const TEST_WEIGHT: Weight = 1_000_000_000;
 
@@ -563,8 +581,9 @@ mod tests {
 		origin: CallOrigin<AccountId, TestAccountPublic, TestSignature>,
 		call: Call,
 	) -> <Pallet<TestRuntime> as MessageDispatch<
-		AccountId,
+		<TestRuntime as frame_system::Config>::Origin,
 		<TestRuntime as Config>::BridgeMessageId,
+		<TestRuntime as Config>::Call,
 	>>::Message {
 		MessagePayload {
 			spec_version: TEST_SPEC_VERSION,
@@ -578,17 +597,19 @@ mod tests {
 	fn prepare_root_message(
 		call: Call,
 	) -> <Pallet<TestRuntime> as MessageDispatch<
-		AccountId,
+		<TestRuntime as frame_system::Config>::Origin,
 		<TestRuntime as Config>::BridgeMessageId,
+		<TestRuntime as Config>::Call,
 	>>::Message {
 		prepare_message(CallOrigin::SourceRoot, call)
 	}
 
 	fn prepare_target_message(
 		call: Call,
 	) -> <Pallet<TestRuntime> as MessageDispatch<
-		AccountId,
+		<TestRuntime as frame_system::Config>::Origin,
 		<TestRuntime as Config>::BridgeMessageId,
+		<TestRuntime as Config>::Call,
 	>>::Message {
 		let origin = CallOrigin::TargetAccount(1, TestAccountPublic(1), TestSignature(1));
 		prepare_message(origin, call)
@@ -597,8 +618,9 @@ mod tests {
 	fn prepare_source_message(
 		call: Call,
 	) -> <Pallet<TestRuntime> as MessageDispatch<
-		AccountId,
+		<TestRuntime as frame_system::Config>::Origin,
 		<TestRuntime as Config>::BridgeMessageId,
+		<TestRuntime as Config>::Call,
 	>>::Message {
 		let origin = CallOrigin::SourceAccount(1);
 		prepare_message(origin, call)

primitives/message-dispatch/src/lib.rs

@@ -35,7 +35,7 @@ pub type Weight = u64;
 pub type SpecVersion = u32;
 
 /// A generic trait to dispatch arbitrary messages delivered over the bridge.
-pub trait MessageDispatch<AccountId, BridgeMessageId> {
+pub trait MessageDispatch<Origin, BridgeMessageId, Call> {
 	/// A type of the message to be dispatched.
 	type Message: codec::Decode;
 
@@ -58,7 +58,7 @@ pub trait MessageDispatch<AccountId, BridgeMessageId> {
 	/// the whole message).
 	///
 	/// Returns unspent dispatch weight.
-	fn dispatch<P: FnOnce(&AccountId, Weight) -> Result<(), ()>>(
+	fn dispatch<P: FnOnce(&Origin, &Call) -> Result<(), ()>>(
 		source_chain: ChainId,
 		target_chain: ChainId,
 		id: BridgeMessageId,
@@ -140,3 +140,18 @@ impl<SourceChainAccountId, TargetChainAccountPublic, TargetChainSignature> Size
 		self.call.len() as _
 	}
 }
+
+/// Customize the dispatch origin before call dispatch.
+pub trait IntoDispatchOrigin<AccountId, Call, Origin> {
+	/// Generate the dispatch origin for the given call.
+	///
+	/// Normally, the dispatch origin is one kind of frame_system::RawOrigin, however, sometimes
+	/// it is useful for a dispatch call with a custom origin.
+	fn into_dispatch_origin(id: &AccountId, call: &Call) -> Origin;
+}
+
+/// A generic trait to filter calls that are allowed to be dispatched.
+pub trait CallFilter<Origin, Call> {
+	/// Filter the call, you might need origin to in the filter. return false, if not allowed.
+	fn contains(origin: &Origin, call: &Call) -> bool;
+}