[stable2603] Backport #11306

polkadot/node/network/collator-protocol/src/lib.rs

@@ -22,25 +22,32 @@
 #![recursion_limit = "256"]
 
 use std::{
-	collections::HashSet,
+	collections::{HashMap, HashSet},
 	sync::Arc,
 	time::{Duration, Instant},
 };
 
 use futures::{
+	channel::oneshot,
 	stream::{FusedStream, StreamExt},
 	FutureExt, TryFutureExt,
 };
 
+use polkadot_node_subsystem::CollatorProtocolSenderTrait;
 use polkadot_node_subsystem_util::{database::Database, reputation::ReputationAggregator};
+use sp_consensus_babe::digests::CompatibleDigestItem;
+use sp_core::H256;
 use sp_keystore::KeystorePtr;
 
 use polkadot_node_network_protocol::{
 	request_response::{v2 as protocol_v2, IncomingRequestReceiver},
 	PeerId, UnifiedReputationChange as Rep,
 };
-use polkadot_node_subsystem::{errors::SubsystemError, overseer, DummySubsystem, SpawnedSubsystem};
-use polkadot_primitives::CollatorPair;
+use polkadot_node_subsystem::{
+	errors::SubsystemError, messages::ChainApiMessage, overseer, DummySubsystem, SpawnedSubsystem,
+};
+use polkadot_primitives::{CollatorPair, Hash, RELAY_CHAIN_SLOT_DURATION_MILLIS};
+use sp_consensus_slots::SlotDuration;
 pub use validator_side_experimental::ReputationConfig;
 
 mod collator_side;
@@ -206,3 +213,48 @@ fn tick_stream(period: Duration) -> impl FusedStream<Item = ()> {
 	})
 	.fuse()
 }
+
+/// Scheduling info tracked per active leaf, used for V3 scheduling parent validation.
+/// Stores the leaf's BABE slot and parent hash so the validator can determine whether
+/// the scheduling parent corresponds to the last finished relay chain slot.
+struct LeafSchedulingInfo {
+	/// The parent hash of the leaf block.
+	parent_hash: Hash,
+	/// The BABE slot of the leaf block.
+	slot: sp_consensus_slots::Slot,
+}
+
+pub(crate) async fn extract_leaf_scheduling_info<Sender: CollatorProtocolSenderTrait>(
+	sender: &mut Sender,
+	leaf: H256,
+) -> Option<LeafSchedulingInfo> {
+	// Fetch leaf header to extract BABE slot for V3 scheduling parent validation.
+	// Without this info, V3 advertisements referencing this leaf will be rejected.
+	let (tx, rx) = oneshot::channel();
+	sender.send_message(ChainApiMessage::BlockHeader(leaf, tx)).await;
+	let header = rx.await.ok().and_then(|r| r.ok().flatten());
+	header.and_then(|header| {
+		let slot = header.digest.logs().iter().find_map(|log| log.as_babe_pre_digest())?.slot();
+		Some(LeafSchedulingInfo { parent_hash: header.parent_hash, slot })
+	})
+}
+
+pub(crate) fn is_scheduling_parent_valid(
+	scheduling_parent: &Hash,
+	leaf_scheduling_info: &HashMap<Hash, LeafSchedulingInfo>,
+) -> bool {
+	let slot_duration = SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS);
+	let current_slot =
+		sp_consensus_slots::Slot::from_timestamp(sp_timestamp::Timestamp::current(), slot_duration);
+	if let Some(info) = leaf_scheduling_info.get(scheduling_parent) {
+		// scheduling_parent is a leaf. This is allowed only when the leaf's slot is
+		// the previous slot.
+		*current_slot == *info.slot + 1
+	} else {
+		// scheduling_parent is not a leaf. This is allowed only if the sp is the parent of
+		// any leaf whose slot is still in progress.
+		leaf_scheduling_info
+			.iter()
+			.any(|(_, info)| *current_slot == *info.slot && *scheduling_parent == info.parent_hash)
+	}
+}

polkadot/node/network/collator-protocol/src/validator_side/mod.rs

@@ -143,6 +143,7 @@ use tokio_util::sync::CancellationToken;
 
 use sp_keystore::KeystorePtr;
 
+use crate::{extract_leaf_scheduling_info, is_scheduling_parent_valid, LeafSchedulingInfo};
 use polkadot_node_network_protocol::{
 	self as net_protocol,
 	peer_set::{CollationVersion, PeerSet, MAX_AUTHORITY_INCOMING_STREAMS},
@@ -156,9 +157,9 @@ use polkadot_node_network_protocol::{
 use polkadot_node_primitives::{SignedFullStatement, Statement};
 use polkadot_node_subsystem::{
 	messages::{
-		CanSecondRequest, CandidateBackingMessage, ChainApiMessage, CollatorProtocolMessage,
-		IfDisconnected, NetworkBridgeEvent, NetworkBridgeTxMessage, ParentHeadData,
-		ProspectiveParachainsMessage, ProspectiveValidationDataRequest,
+		CanSecondRequest, CandidateBackingMessage, CollatorProtocolMessage, IfDisconnected,
+		NetworkBridgeEvent, NetworkBridgeTxMessage, ParentHeadData, ProspectiveParachainsMessage,
+		ProspectiveValidationDataRequest,
 	},
 	overseer, CollatorProtocolSenderTrait, FromOrchestra, OverseerSignal, SubsystemError,
 };
@@ -170,10 +171,7 @@ use polkadot_node_subsystem_util::{
 use polkadot_primitives::{
 	CandidateDescriptorV2, CandidateDescriptorVersion, CandidateHash, CollatorId, CoreIndex, Hash,
 	HeadData, Id as ParaId, OccupiedCoreAssumption, PersistedValidationData, SessionIndex,
-	RELAY_CHAIN_SLOT_DURATION_MILLIS,
 };
-use sp_consensus_babe::digests::CompatibleDigestItem;
-use sp_consensus_slots::SlotDuration;
 
 use super::{modify_reputation, tick_stream, LOG_TARGET};
 
@@ -580,16 +578,6 @@ struct HeldOffAdvertisement {
 	advertised_descriptor_version: Option<CandidateDescriptorVersion>,
 }
 
-/// Scheduling info tracked per active leaf, used for V3 scheduling parent validation.
-/// Stores the leaf's BABE slot and parent hash so the validator can determine whether
-/// the scheduling parent corresponds to the last finished relay chain slot.
-struct LeafSchedulingInfo {
-	/// The parent hash of the leaf block.
-	parent_hash: Hash,
-	/// The BABE slot of the leaf block.
-	slot: sp_consensus_slots::Slot,
-}
-
 /// All state relevant for the validator side of the protocol lives here.
 #[derive(Default)]
 struct State {
@@ -1752,26 +1740,7 @@ where
 	// finished relay chain slot. We compare slot numbers rather than timestamps to keep
 	// the logic simple and aligned with how BABE/Aura reason about slots.
 	if candidate_descriptor_version == CandidateDescriptorVersion::V3 {
-		let slot_duration = SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS);
-		let current_slot = sp_consensus_slots::Slot::from_timestamp(
-			sp_timestamp::Timestamp::current(),
-			slot_duration,
-		);
-
-		let scheduling_parent_valid =
-			if let Some(info) = state.leaf_scheduling_info.get(&scheduling_parent) {
-				// scheduling_parent is a leaf — valid only if the leaf's slot is exactly
-				// one behind the current slot (i.e., it just finished).
-				*current_slot == *info.slot + 1
-			} else {
-				// scheduling_parent is not a leaf — valid if it's the parent of any leaf
-				// whose slot is the current slot (still in progress).
-				state.leaf_scheduling_info.iter().any(|(_leaf_hash, info)| {
-					*current_slot == *info.slot && scheduling_parent == info.parent_hash
-				})
-			};
-
-		if !scheduling_parent_valid {
+		if !is_scheduling_parent_valid(&scheduling_parent, &state.leaf_scheduling_info) {
 			return Err(AdvertisementError::SchedulingParentNotValid);
 		}
 	}
@@ -2001,15 +1970,7 @@ where
 		state.per_scheduling_parent.insert(*leaf, per_scheduling_parent);
 		state.leaf_claim_queues.insert(*leaf, leaf_claim_queue);
 
-		// Fetch leaf header to extract BABE slot for V3 scheduling parent validation.
-		// Without this info, V3 advertisements referencing this leaf will be rejected.
-		let (tx, rx) = oneshot::channel();
-		sender.send_message(ChainApiMessage::BlockHeader(*leaf, tx)).await;
-		let header = rx.await.ok().and_then(|r| r.ok()).flatten();
-		match header.and_then(|h| {
-			let slot = h.digest.logs().iter().find_map(|log| log.as_babe_pre_digest())?.slot();
-			Some(LeafSchedulingInfo { parent_hash: h.parent_hash, slot })
-		}) {
+		match extract_leaf_scheduling_info(sender, *leaf).await {
 			Some(info) => {
 				state.leaf_scheduling_info.insert(*leaf, info);
 			},

polkadot/node/network/collator-protocol/src/validator_side/tests/prospective_parachains.rs

@@ -22,7 +22,7 @@ use polkadot_node_subsystem::messages::ChainApiMessage;
 use polkadot_primitives::{
 	BlockNumber, CandidateCommitments, CandidateDescriptorVersion,
 	CommittedCandidateReceiptV2 as CommittedCandidateReceipt, Header, MutateDescriptorV2,
-	SigningContext, ValidatorId,
+	SigningContext, ValidatorId, RELAY_CHAIN_SLOT_DURATION_MILLIS,
 };
 use polkadot_primitives_test_helpers::{
 	dummy_committed_candidate_receipt_v2, dummy_committed_candidate_receipt_v3,