feat: block gossip validation for parent payload (consensus-specs#4923)

packages/beacon-node/src/chain/errors/blockError.ts

@@ -70,6 +70,8 @@ export enum BlockErrorCode {
   TOO_MANY_KZG_COMMITMENTS = "BLOCK_ERROR_TOO_MANY_KZG_COMMITMENTS",
   /** Bid parent block root does not match block parent root */
   BID_PARENT_ROOT_MISMATCH = "BLOCK_ERROR_BID_PARENT_ROOT_MISMATCH",
+  /** Parent execution payload has not been seen */
+  PARENT_PAYLOAD_UNKNOWN = "BLOCK_ERROR_PARENT_PAYLOAD_UNKNOWN",
 }
 
 type ExecutionErrorStatus = Exclude<
@@ -114,7 +116,8 @@ export type BlockErrorType =
   | {code: BlockErrorCode.EXECUTION_ENGINE_ERROR; execStatus: ExecutionErrorStatus; errorMessage: string}
   | {code: BlockErrorCode.DATA_UNAVAILABLE}
   | {code: BlockErrorCode.TOO_MANY_KZG_COMMITMENTS; blobKzgCommitmentsLen: number; commitmentLimit: number}
-  | {code: BlockErrorCode.BID_PARENT_ROOT_MISMATCH; bidParentRoot: RootHex; blockParentRoot: RootHex};
+  | {code: BlockErrorCode.BID_PARENT_ROOT_MISMATCH; bidParentRoot: RootHex; blockParentRoot: RootHex}
+  | {code: BlockErrorCode.PARENT_PAYLOAD_UNKNOWN; parentBlockHash: RootHex};
 
 export class BlockGossipError extends GossipActionError<BlockErrorType> {}
 

packages/beacon-node/src/chain/validation/block.ts

@@ -153,6 +153,17 @@ export async function validateGossipBlock(
       });
     }
 
+    // [IGNORE] The block's parent execution payload (defined by bid.parent_block_hash) has been seen
+    // (via gossip or non-gossip sources) (a client MAY queue blocks for processing once the parent
+    // payload is retrieved).
+    const parentBlockHashHex = toRootHex(bid.parentBlockHash);
+    if (!chain.forkChoice.hasExecutionPayload(parentBlockHashHex)) {
+      throw new BlockGossipError(GossipAction.IGNORE, {
+        code: BlockErrorCode.PARENT_PAYLOAD_UNKNOWN,
+        parentBlockHash: parentBlockHashHex,
+      });
+    }
+
     // TODO GLOAS: [REJECT] The block's execution payload parent (defined by bid.parent_block_hash) passes all validation
     // This requires execution engine integration to verify the parent block hash
   }

packages/fork-choice/src/forkChoice/forkChoice.ts

@@ -1056,6 +1056,14 @@ export class ForkChoice implements IForkChoice {
     return this.protoArray.hasBlock(blockRoot);
   }
 
+  /**
+   * Check if an execution payload with the given block hash has been seen.
+   * Spec: gloas/p2p-interface.md — parent execution payload must have been seen
+   */
+  hasExecutionPayload(executionPayloadBlockHash: RootHex): boolean {
+    return this.protoArray.hasExecutionPayload(executionPayloadBlockHash);
+  }
+
   /**
    * Returns a MUTABLE `ProtoBlock` if the block is known **and** a descendant of the finalized root.
    */

packages/fork-choice/src/forkChoice/interface.ts

@@ -228,6 +228,11 @@ export interface IForkChoice {
    */
   hasBlockUnsafe(blockRoot: Root): boolean;
   hasBlockHexUnsafe(blockRoot: RootHex): boolean;
+  /**
+   * Check if an execution payload with the given block hash has been seen.
+   * For Gloas: checks if any block has a FULL variant with matching execution payload block hash.
+   */
+  hasExecutionPayload(executionPayloadBlockHash: RootHex): boolean;
   getSlotsPresent(windowStart: number): number;
   /**
    * Returns a `ProtoBlock` if the block is known **and** a descendant of the finalized root.

packages/fork-choice/src/protoArray/protoArray.ts

@@ -70,6 +70,13 @@ export class ProtoArray {
    */
   private ptcVotes = new Map<RootHex, BitArray>();
 
+  /**
+   * Secondary index: O(1) lookup by execution payload block hash.
+   * Maintained by onBlock() (pre-Gloas) and onExecutionPayload() (Gloas).
+   * Pruned in maybePrune().
+   */
+  private executionPayloadBlockHashes = new Set<RootHex>();
+
   constructor({
     pruneThreshold,
     justifiedEpoch,
@@ -515,6 +522,11 @@ export class ProtoArray {
       // Pre-Gloas: store FULL index instead of array
       this.indices.set(block.blockRoot, nodeIndex);
 
+      // Maintain secondary index for O(1) hasExecutionPayload lookups
+      if (block.executionPayloadBlockHash != null) {
+        this.executionPayloadBlockHashes.add(block.executionPayloadBlockHash);
+      }
+
       // If this node is valid, lets propagate the valid status up the chain
       // and throw error if we counter invalid, as this breaks consensus
       if (node.parent !== undefined) {
@@ -602,6 +614,9 @@ export class ProtoArray {
     // Add FULL variant to the indices array
     variants[PayloadStatus.FULL] = fullIndex;
 
+    // Maintain secondary index for O(1) hasExecutionPayload lookups
+    this.executionPayloadBlockHashes.add(executionPayloadBlockHash);
+
     // Update bestChild for PENDING node (may now prefer FULL over EMPTY)
     this.maybeUpdateBestChildAndDescendant(pendingIndex, fullIndex, currentSlot, proposerBoostRoot);
   }
@@ -1078,6 +1093,13 @@ export class ProtoArray {
       prunedRoots.add(node.blockRoot);
     }
 
+    // Clean up secondary execution payload block hash index
+    for (let i = 0; i < finalizedIndex; i++) {
+      const node = this.nodes[i];
+      if (node?.executionPayloadBlockHash != null) {
+        this.executionPayloadBlockHashes.delete(node.executionPayloadBlockHash);
+      }
+    }
     // Remove indices for pruned blocks and PTC votes
     for (const root of prunedRoots) {
       this.indices.delete(root);
@@ -1671,6 +1693,16 @@ export class ProtoArray {
     return this.getDefaultNodeIndex(blockRoot) !== undefined;
   }
 
+  /**
+   * Check if an execution payload with the given block hash has been seen.
+   * Used for Gloas gossip validation: parent execution payload must have been seen.
+   *
+   * O(1) via secondary index maintained in onBlock() (pre-Gloas) and onExecutionPayload() (Gloas).
+   */
+  hasExecutionPayload(executionPayloadBlockHash: RootHex): boolean {
+    return this.executionPayloadBlockHashes.has(executionPayloadBlockHash);
+  }
+
   /**
    * Return ProtoNode for blockRoot with explicit payload status
    *