Disabled validators runtime API (#1257)

Exposes disabled validators list via a runtime API.

---------

Co-authored-by: ordian <noreply@reusable.software>
Co-authored-by: ordian <write@reusable.software>

cumulus/client/relay-chain-minimal-node/src/blockchain_rpc_client.rs

@@ -346,6 +346,13 @@ impl RuntimeApiSubsystemClient for BlockChainRpcClient {
 		Ok(self.rpc_client.parachain_host_minimum_backing_votes(at, session_index).await?)
 	}
 
+	async fn disabled_validators(
+		&self,
+		at: Hash,
+	) -> Result<Vec<polkadot_primitives::ValidatorIndex>, ApiError> {
+		Ok(self.rpc_client.parachain_host_disabled_validators(at).await?)
+	}
+
 	async fn async_backing_params(&self, at: Hash) -> Result<AsyncBackingParams, ApiError> {
 		Ok(self.rpc_client.parachain_host_async_backing_params(at).await?)
 	}

cumulus/client/relay-chain-rpc-interface/src/rpc_client.rs

@@ -597,6 +597,14 @@ impl RelayChainRpcClient {
 			.await
 	}
 
+	pub async fn parachain_host_disabled_validators(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<ValidatorIndex>, RelayChainError> {
+		self.call_remote_runtime_function("ParachainHost_disabled_validators", at, None::<()>)
+			.await
+	}
+
 	#[allow(missing_docs)]
 	pub async fn parachain_host_async_backing_params(
 		&self,

cumulus/parachains/integration-tests/emulated/common/src/lib.rs

@@ -33,7 +33,7 @@ use xcm_emulator::{
 };
 
 decl_test_relay_chains! {
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Westend {
 		genesis = westend::genesis(),
 		on_init = (),
@@ -50,7 +50,7 @@ decl_test_relay_chains! {
 			AssetRate: westend_runtime::AssetRate,
 		}
 	},
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Rococo {
 		genesis = rococo::genesis(),
 		on_init = (),
@@ -65,7 +65,7 @@ decl_test_relay_chains! {
 			Balances: rococo_runtime::Balances,
 		}
 	},
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Wococo {
 		genesis = rococo::genesis(),
 		on_init = (),

polkadot/node/core/runtime-api/src/cache.rs

@@ -64,6 +64,7 @@ pub(crate) struct RequestResultCache {
 	unapplied_slashes: LruMap<Hash, Vec<(SessionIndex, CandidateHash, slashing::PendingSlashes)>>,
 	key_ownership_proof: LruMap<(Hash, ValidatorId), Option<slashing::OpaqueKeyOwnershipProof>>,
 	minimum_backing_votes: LruMap<SessionIndex, u32>,
+	disabled_validators: LruMap<Hash, Vec<ValidatorIndex>>,
 	para_backing_state: LruMap<(Hash, ParaId), Option<async_backing::BackingState>>,
 	async_backing_params: LruMap<Hash, async_backing::AsyncBackingParams>,
 }
@@ -96,6 +97,7 @@ impl Default for RequestResultCache {
 			unapplied_slashes: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			key_ownership_proof: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			minimum_backing_votes: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
+			disabled_validators: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			para_backing_state: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			async_backing_params: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 		}
@@ -444,6 +446,21 @@ impl RequestResultCache {
 		self.minimum_backing_votes.insert(session_index, minimum_backing_votes);
 	}
 
+	pub(crate) fn disabled_validators(
+		&mut self,
+		relay_parent: &Hash,
+	) -> Option<&Vec<ValidatorIndex>> {
+		self.disabled_validators.get(relay_parent).map(|v| &*v)
+	}
+
+	pub(crate) fn cache_disabled_validators(
+		&mut self,
+		relay_parent: Hash,
+		disabled_validators: Vec<ValidatorIndex>,
+	) {
+		self.disabled_validators.insert(relay_parent, disabled_validators);
+	}
+
 	pub(crate) fn para_backing_state(
 		&mut self,
 		key: (Hash, ParaId),
@@ -520,6 +537,7 @@ pub(crate) enum RequestResult {
 		slashing::OpaqueKeyOwnershipProof,
 		Option<()>,
 	),
+	DisabledValidators(Hash, Vec<ValidatorIndex>),
 	ParaBackingState(Hash, ParaId, Option<async_backing::BackingState>),
 	AsyncBackingParams(Hash, async_backing::AsyncBackingParams),
 }

polkadot/node/core/runtime-api/src/lib.rs

@@ -166,6 +166,8 @@ where
 				.requests_cache
 				.cache_key_ownership_proof((relay_parent, validator_id), key_ownership_proof),
 			SubmitReportDisputeLost(_, _, _, _) => {},
+			DisabledValidators(relay_parent, disabled_validators) =>
+				self.requests_cache.cache_disabled_validators(relay_parent, disabled_validators),
 			ParaBackingState(relay_parent, para_id, constraints) => self
 				.requests_cache
 				.cache_para_backing_state((relay_parent, para_id), constraints),
@@ -296,6 +298,8 @@ where
 						Request::SubmitReportDisputeLost(dispute_proof, key_ownership_proof, sender)
 					},
 				),
+			Request::DisabledValidators(sender) => query!(disabled_validators(), sender)
+				.map(|sender| Request::DisabledValidators(sender)),
 			Request::ParaBackingState(para, sender) => query!(para_backing_state(para), sender)
 				.map(|sender| Request::ParaBackingState(para, sender)),
 			Request::AsyncBackingParams(sender) => query!(async_backing_params(), sender)
@@ -565,6 +569,12 @@ where
 			ver = Request::MINIMUM_BACKING_VOTES_RUNTIME_REQUIREMENT,
 			sender
 		),
+		Request::DisabledValidators(sender) => query!(
+			DisabledValidators,
+			disabled_validators(),
+			ver = Request::DISABLED_VALIDATORS_RUNTIME_REQUIREMENT,
+			sender
+		),
 		Request::ParaBackingState(para, sender) => {
 			query!(
 				ParaBackingState,

polkadot/node/core/runtime-api/src/tests.rs

@@ -268,6 +268,10 @@ impl RuntimeApiSubsystemClient for MockSubsystemClient {
 	async fn minimum_backing_votes(&self, _: Hash, _: SessionIndex) -> Result<u32, ApiError> {
 		todo!("Not required for tests")
 	}
+
+	async fn disabled_validators(&self, _: Hash) -> Result<Vec<ValidatorIndex>, ApiError> {
+		todo!("Not required for tests")
+	}
 }
 
 #[test]

polkadot/node/subsystem-types/src/messages.rs

@@ -695,6 +695,8 @@ pub enum RuntimeApiRequest {
 	),
 	/// Get the minimum required backing votes.
 	MinimumBackingVotes(SessionIndex, RuntimeApiSender<u32>),
+	/// Returns all disabled validators at a given block height.
+	DisabledValidators(RuntimeApiSender<Vec<ValidatorIndex>>),
 	/// Get the backing state of the given para.
 	ParaBackingState(ParaId, RuntimeApiSender<Option<async_backing::BackingState>>),
 	/// Get candidate's acceptance limitations for asynchronous backing for a relay parent.
@@ -726,6 +728,9 @@ impl RuntimeApiRequest {
 
 	/// Minimum version to enable asynchronous backing: `AsyncBackingParams` and `ParaBackingState`.
 	pub const ASYNC_BACKING_STATE_RUNTIME_REQUIREMENT: u32 = 7;
+
+	/// `DisabledValidators`
+	pub const DISABLED_VALIDATORS_RUNTIME_REQUIREMENT: u32 = 8;
 }
 
 /// A message to the Runtime API subsystem.

polkadot/node/subsystem-types/src/runtime_client.rs

@@ -255,6 +255,10 @@ pub trait RuntimeApiSubsystemClient {
 		at: Hash,
 		para_id: Id,
 	) -> Result<Option<async_backing::BackingState>, ApiError>;
+
+	// === v8 ===
+	/// Gets the disabled validators at a specific block height
+	async fn disabled_validators(&self, at: Hash) -> Result<Vec<ValidatorIndex>, ApiError>;
 }
 
 /// Default implementation of [`RuntimeApiSubsystemClient`] using the client.
@@ -497,11 +501,14 @@ where
 		self.client.runtime_api().para_backing_state(at, para_id)
 	}
 
-	/// Returns candidate's acceptance limitations for asynchronous backing for a relay parent.
 	async fn async_backing_params(
 		&self,
 		at: Hash,
 	) -> Result<async_backing::AsyncBackingParams, ApiError> {
 		self.client.runtime_api().async_backing_params(at)
 	}
+
+	async fn disabled_validators(&self, at: Hash) -> Result<Vec<ValidatorIndex>, ApiError> {
+		self.client.runtime_api().disabled_validators(at)
+	}
 }

polkadot/node/subsystem-util/src/lib.rs

@@ -226,6 +226,7 @@ specialize_requests! {
 	fn request_unapplied_slashes() -> Vec<(SessionIndex, CandidateHash, slashing::PendingSlashes)>; UnappliedSlashes;
 	fn request_key_ownership_proof(validator_id: ValidatorId) -> Option<slashing::OpaqueKeyOwnershipProof>; KeyOwnershipProof;
 	fn request_submit_report_dispute_lost(dp: slashing::DisputeProof, okop: slashing::OpaqueKeyOwnershipProof) -> Option<()>; SubmitReportDisputeLost;
+	fn request_disabled_validators() -> Vec<ValidatorIndex>; DisabledValidators;
 	fn request_async_backing_params() -> AsyncBackingParams; AsyncBackingParams;
 }
 

polkadot/primitives/src/runtime_api.rs

@@ -248,6 +248,7 @@ sp_api::decl_runtime_apis! {
 		#[api_version(6)]
 		fn minimum_backing_votes() -> u32;
 
+
 		/***** Added in v7: Asynchronous backing *****/
 
 		/// Returns the state of parachain backing for a given para.
@@ -257,5 +258,11 @@ sp_api::decl_runtime_apis! {
 		/// Returns candidate's acceptance limitations for asynchronous backing for a relay parent.
 		#[api_version(7)]
 		fn async_backing_params() -> AsyncBackingParams;
+
+		/***** Added in v8 *****/
+
+		/// Returns a list of all disabled validators at the given block.
+		#[api_version(8)]
+		fn disabled_validators() -> Vec<ValidatorIndex>;
 	}
 }

polkadot/runtime/parachains/src/runtime_api_impl/vstaging.rs

@@ -15,3 +15,30 @@
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
 //! Put implementations of functions from staging APIs here.
+
+use crate::shared;
+use primitives::ValidatorIndex;
+use sp_std::{collections::btree_map::BTreeMap, prelude::Vec};
+
+/// Implementation for `DisabledValidators`
+// CAVEAT: this should only be called on the node side
+// as it might produce incorrect results on session boundaries
+pub fn disabled_validators<T>() -> Vec<ValidatorIndex>
+where
+	T: pallet_session::Config + shared::Config,
+{
+	let shuffled_indices = <shared::Pallet<T>>::active_validator_indices();
+	// mapping from raw validator index to `ValidatorIndex`
+	// this computation is the same within a session, but should be cheap
+	let reverse_index = shuffled_indices
+		.iter()
+		.enumerate()
+		.map(|(i, v)| (v.0, ValidatorIndex(i as u32)))
+		.collect::<BTreeMap<u32, ValidatorIndex>>();
+
+	// we might have disabled validators who are not parachain validators
+	<pallet_session::Pallet<T>>::disabled_validators()
+		.iter()
+		.filter_map(|v| reverse_index.get(v).cloned())
+		.collect()
+}

polkadot/runtime/rococo/src/lib.rs

@@ -49,7 +49,9 @@ use runtime_parachains::{
 	inclusion::{AggregateMessageOrigin, UmpQueueId},
 	initializer as parachains_initializer, origin as parachains_origin, paras as parachains_paras,
 	paras_inherent as parachains_paras_inherent,
-	runtime_api_impl::v7 as parachains_runtime_api_impl,
+	runtime_api_impl::{
+		v7 as parachains_runtime_api_impl, vstaging as parachains_staging_runtime_api_impl,
+	},
 	scheduler as parachains_scheduler, session_info as parachains_session_info,
 	shared as parachains_shared,
 };
@@ -1585,7 +1587,7 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 
-	#[api_version(7)]
+	#[api_version(8)]
 	impl primitives::runtime_api::ParachainHost<Block, Hash, BlockNumber> for Runtime {
 		fn validators() -> Vec<ValidatorId> {
 			parachains_runtime_api_impl::validators::<Runtime>()
@@ -1728,6 +1730,11 @@ sp_api::impl_runtime_apis! {
 		fn async_backing_params() -> primitives::AsyncBackingParams {
 			parachains_runtime_api_impl::async_backing_params::<Runtime>()
 		}
+
+		fn disabled_validators() -> Vec<ValidatorIndex> {
+			parachains_staging_runtime_api_impl::disabled_validators::<Runtime>()
+		}
+
 	}
 
 	#[api_version(3)]

polkadot/runtime/westend/src/lib.rs

@@ -70,7 +70,9 @@ use runtime_parachains::{
 	inclusion::{AggregateMessageOrigin, UmpQueueId},
 	initializer as parachains_initializer, origin as parachains_origin, paras as parachains_paras,
 	paras_inherent as parachains_paras_inherent, reward_points as parachains_reward_points,
-	runtime_api_impl::v7 as parachains_runtime_api_impl,
+	runtime_api_impl::{
+		v7 as parachains_runtime_api_impl, vstaging as parachains_staging_runtime_api_impl,
+	},
 	scheduler as parachains_scheduler, session_info as parachains_session_info,
 	shared as parachains_shared,
 };
@@ -1695,7 +1697,7 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 
-	#[api_version(7)]
+	#[api_version(8)]
 	impl primitives::runtime_api::ParachainHost<Block, Hash, BlockNumber> for Runtime {
 		fn validators() -> Vec<ValidatorId> {
 			parachains_runtime_api_impl::validators::<Runtime>()
@@ -1838,6 +1840,10 @@ sp_api::impl_runtime_apis! {
 		fn async_backing_params() -> primitives::AsyncBackingParams {
 			parachains_runtime_api_impl::async_backing_params::<Runtime>()
 		}
+
+		fn disabled_validators() -> Vec<ValidatorIndex> {
+			parachains_staging_runtime_api_impl::disabled_validators::<Runtime>()
+		}
 	}
 
 	impl beefy_primitives::BeefyApi<Block, BeefyId> for Runtime {