babe, grandpa: set longevity for equivocation report transactions (#8076)

* babe: set longevity for equivocation report transactions

* grandpa: set longevity for equivocation report transaction

* babe, grandpa: fix tests

* node: add ReportLongevity to babe and grandpa modules

* node: bump spec_version

substrate/frame/grandpa/src/equivocation.rs

@@ -40,7 +40,10 @@
 use sp_std::prelude::*;
 
 use codec::{self as codec, Decode, Encode};
-use frame_support::{debug, traits::KeyOwnerProofSystem};
+use frame_support::{
+	debug,
+	traits::{Get, KeyOwnerProofSystem},
+};
 use sp_finality_grandpa::{EquivocationProof, RoundNumber, SetId};
 use sp_runtime::{
 	transaction_validity::{
@@ -64,6 +67,10 @@ pub trait HandleEquivocation<T: Config> {
 	/// The offence type used for reporting offences on valid equivocation reports.
 	type Offence: GrandpaOffence<T::KeyOwnerIdentification>;
 
+	/// The longevity, in blocks, that the equivocation report is valid for. When using the staking
+	/// pallet this should be equal to the bonding duration (in blocks, not eras).
+	type ReportLongevity: Get<u64>;
+
 	/// Report an offence proved by the given reporters.
 	fn report_offence(
 		reporters: Vec<T::AccountId>,
@@ -88,6 +95,7 @@ pub trait HandleEquivocation<T: Config> {
 
 impl<T: Config> HandleEquivocation<T> for () {
 	type Offence = GrandpaEquivocationOffence<T::KeyOwnerIdentification>;
+	type ReportLongevity = ();
 
 	fn report_offence(
 		_reporters: Vec<T::AccountId>,
@@ -119,11 +127,11 @@ impl<T: Config> HandleEquivocation<T> for () {
 /// using existing subsystems that are part of frame (type bounds described
 /// below) and will dispatch to them directly, it's only purpose is to wire all
 /// subsystems together.
-pub struct EquivocationHandler<I, R, O = GrandpaEquivocationOffence<I>> {
-	_phantom: sp_std::marker::PhantomData<(I, R, O)>,
+pub struct EquivocationHandler<I, R, L, O = GrandpaEquivocationOffence<I>> {
+	_phantom: sp_std::marker::PhantomData<(I, R, L, O)>,
 }
 
-impl<I, R, O> Default for EquivocationHandler<I, R, O> {
+impl<I, R, L, O> Default for EquivocationHandler<I, R, L, O> {
 	fn default() -> Self {
 		Self {
 			_phantom: Default::default(),
@@ -131,7 +139,7 @@ impl<I, R, O> Default for EquivocationHandler<I, R, O> {
 	}
 }
 
-impl<T, R, O> HandleEquivocation<T> for EquivocationHandler<T::KeyOwnerIdentification, R, O>
+impl<T, R, L, O> HandleEquivocation<T> for EquivocationHandler<T::KeyOwnerIdentification, R, L, O>
 where
 	// We use the authorship pallet to fetch the current block author and use
 	// `offchain::SendTransactionTypes` for unsigned extrinsic creation and
@@ -140,10 +148,14 @@ where
 	// A system for reporting offences after valid equivocation reports are
 	// processed.
 	R: ReportOffence<T::AccountId, T::KeyOwnerIdentification, O>,
+	// The longevity (in blocks) that the equivocation report is valid for. When using the staking
+	// pallet this should be the bonding duration.
+	L: Get<u64>,
 	// The offence type that should be used when reporting.
 	O: GrandpaOffence<T::KeyOwnerIdentification>,
 {
 	type Offence = O;
+	type ReportLongevity = L;
 
 	fn report_offence(reporters: Vec<T::AccountId>, offence: O) -> Result<(), OffenceError> {
 		R::report_offence(reporters, offence)
@@ -207,6 +219,8 @@ impl<T: Config> frame_support::unsigned::ValidateUnsigned for Module<T> {
 			// check report staleness
 			is_known_offence::<T>(equivocation_proof, key_owner_proof)?;
 
+			let longevity = <T::HandleEquivocation as HandleEquivocation<T>>::ReportLongevity::get();
+
 			ValidTransaction::with_tag_prefix("GrandpaEquivocation")
 				// We assign the maximum priority for any equivocation report.
 				.priority(TransactionPriority::max_value())
@@ -216,6 +230,7 @@ impl<T: Config> frame_support::unsigned::ValidateUnsigned for Module<T> {
 					equivocation_proof.set_id(),
 					equivocation_proof.round(),
 				))
+				.longevity(longevity)
 				// We don't propagate this. This can never be included on a remote node.
 				.propagate(false)
 				.build()

substrate/frame/grandpa/src/mock.rs

@@ -226,6 +226,11 @@ impl pallet_offences::Config for Test {
 	type WeightSoftLimit = OffencesWeightSoftLimit;
 }
 
+parameter_types! {
+	pub const ReportLongevity: u64 =
+		BondingDuration::get() as u64 * SessionsPerEra::get() as u64 * Period::get();
+}
+
 impl Config for Test {
 	type Event = Event;
 	type Call = Call;
@@ -240,7 +245,8 @@ impl Config for Test {
 		AuthorityId,
 	)>>::IdentificationTuple;
 
-	type HandleEquivocation = super::EquivocationHandler<Self::KeyOwnerIdentification, Offences>;
+	type HandleEquivocation =
+		super::EquivocationHandler<Self::KeyOwnerIdentification, Offences, ReportLongevity>;
 
 	type WeightInfo = ();
 }

substrate/frame/grandpa/src/tests.rs

@@ -706,8 +706,8 @@ fn report_equivocation_invalid_equivocation_proof() {
 #[test]
 fn report_equivocation_validate_unsigned_prevents_duplicates() {
 	use sp_runtime::transaction_validity::{
-		InvalidTransaction, TransactionLongevity, TransactionPriority, TransactionSource,
-		TransactionValidity, ValidTransaction,
+		InvalidTransaction, TransactionPriority, TransactionSource, TransactionValidity,
+		ValidTransaction,
 	};
 
 	let authorities = test_authorities();
@@ -762,7 +762,7 @@ fn report_equivocation_validate_unsigned_prevents_duplicates() {
 				priority: TransactionPriority::max_value(),
 				requires: vec![],
 				provides: vec![("GrandpaEquivocation", tx_tag).encode()],
-				longevity: TransactionLongevity::max_value(),
+				longevity: ReportLongevity::get(),
 				propagate: false,
 			})
 		);