meta tx marker

Cargo.lock

@@ -30929,6 +30929,7 @@ dependencies = [
  "pallet-transaction-payment-rpc-runtime-api 28.0.0",
  "pallet-treasury 27.0.0",
  "pallet-utility 28.0.0",
+ "pallet-verify-signature",
  "pallet-vesting 28.0.0",
  "pallet-whitelist 27.0.0",
  "pallet-xcm 7.0.0",

polkadot/runtime/westend/Cargo.toml

@@ -97,6 +97,7 @@ pallet-transaction-payment = { workspace = true }
 pallet-transaction-payment-rpc-runtime-api = { workspace = true }
 pallet-treasury = { workspace = true }
 pallet-utility = { workspace = true }
+pallet-verify-signature = { workspace = true }
 pallet-vesting = { workspace = true }
 pallet-whitelist = { workspace = true }
 pallet-xcm = { workspace = true }

polkadot/runtime/westend/src/lib.rs

@@ -1588,6 +1588,8 @@ impl OnSwap for SwapLeases {
 }
 
 pub type MetaTxExtension = (
+	pallet_verify_signature::VerifySignature<Runtime>,
+	pallet_meta_tx::MetaTxMarker<Runtime>,
 	frame_system::CheckNonZeroSender<Runtime>,
 	frame_system::CheckSpecVersion<Runtime>,
 	frame_system::CheckTxVersion<Runtime>,

substrate/bin/node/runtime/src/lib.rs

@@ -2357,6 +2357,8 @@ impl pallet_parameters::Config for Runtime {
 }
 
 pub type MetaTxExtension = (
+	pallet_verify_signature::VerifySignature<Runtime>,
+	pallet_meta_tx::MetaTxMarker<Runtime>,
 	frame_system::CheckNonZeroSender<Runtime>,
 	frame_system::CheckSpecVersion<Runtime>,
 	frame_system::CheckTxVersion<Runtime>,

substrate/frame/meta-tx/src/extension.rs

+// This file is part of Substrate.
+
+// Copyright (C) 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 super::*;
+use sp_runtime::impl_tx_ext_default;
+
+/// This type serves as a marker extension to differentiate meta-transactions from regular
+/// transactions. It implements the `TransactionExtension` trait and carries constant implicit data
+/// ("_meta_tx").
+#[derive(Encode, Decode, Clone, Eq, PartialEq, TypeInfo, DebugNoBound)]
+#[scale_info(skip_type_params(T))]
+pub struct MetaTxMarker<T> {
+	_phantom: core::marker::PhantomData<T>,
+}
+
+impl<T> MetaTxMarker<T> {
+	/// Creates new `TransactionExtension` with implicit meta tx marked.
+	pub fn new() -> Self {
+		Self { _phantom: Default::default() }
+	}
+}
+
+impl<T: Config + Send + Sync> TransactionExtension<T::RuntimeCall> for MetaTxMarker<T> {
+	const IDENTIFIER: &'static str = "MetaTxMarker";
+	type Implicit = [u8; 8];
+	type Val = ();
+	type Pre = ();
+	fn implicit(&self) -> Result<Self::Implicit, TransactionValidityError> {
+		Ok(*b"_meta_tx")
+	}
+	fn weight(&self, _: &T::RuntimeCall) -> Weight {
+		Weight::zero()
+	}
+	impl_tx_ext_default!(T::RuntimeCall; validate prepare);
+}

substrate/frame/meta-tx/src/lib.rs

@@ -62,6 +62,8 @@ pub mod weights;
 pub use benchmarking::types::WeightlessExtension;
 pub use pallet::*;
 pub use weights::WeightInfo;
+mod extension;
+pub use extension::MetaTxMarker;
 
 use core::ops::Add;
 use frame_support::{

substrate/frame/meta-tx/src/mock.rs

@@ -76,6 +76,7 @@ mod tx_ext {
 	///
 	/// Helper type used to decode the part of the extension which should be signed.
 	pub type MetaTxBareExtension = (
+		MetaTxMarker<Runtime>,
 		frame_system::CheckNonZeroSender<Runtime>,
 		frame_system::CheckSpecVersion<Runtime>,
 		frame_system::CheckTxVersion<Runtime>,

substrate/frame/meta-tx/src/tests.rs

@@ -45,6 +45,7 @@ fn create_tx_bare_ext(account: AccountId) -> TxBareExtension {
 
 pub fn create_meta_tx_bare_ext(account: AccountId) -> MetaTxBareExtension {
 	(
+		MetaTxMarker::new(),
 		frame_system::CheckNonZeroSender::<Runtime>::new(),
 		frame_system::CheckSpecVersion::<Runtime>::new(),
 		frame_system::CheckTxVersion::<Runtime>::new(),