feat: wire up proposer_preferences gossip topic

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

@@ -106,6 +106,7 @@ import {
   SeenExecutionPayloadBids,
   SeenPayloadAttesters,
   SeenPayloadEnvelopeInput,
+  SeenProposerPreferences,
   SeenSyncCommitteeMessages,
 } from "./seenCache/index.js";
 import {SeenAggregatedAttestations} from "./seenCache/seenAggregateAndProof.js";
@@ -186,6 +187,7 @@ export class BeaconChain implements IBeaconChain {
   readonly seenPayloadAttesters = new SeenPayloadAttesters();
   readonly seenAggregatedAttestations: SeenAggregatedAttestations;
   readonly seenExecutionPayloadBids = new SeenExecutionPayloadBids();
+  readonly seenProposerPreferences = new SeenProposerPreferences();
   readonly seenBlockProposers = new SeenBlockProposers();
   readonly seenSyncCommitteeMessages = new SeenSyncCommitteeMessages();
   readonly seenContributionAndProof: SeenContributionAndProof;
@@ -1437,6 +1439,7 @@ export class BeaconChain implements IBeaconChain {
     this.payloadAttestationPool.prune(slot);
     this.executionPayloadBidPool.prune(slot);
     this.seenExecutionPayloadBids.prune(slot);
+    this.seenProposerPreferences.prune(slot);
     this.seenAttestationDatas.onSlot(slot);
     this.reprocessController.onSlot(slot);
 

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

@@ -8,6 +8,7 @@ export * from "./executionPayloadBid.js";
 export * from "./executionPayloadEnvelope.js";
 export * from "./gossipValidation.js";
 export * from "./payloadAttestation.js";
+export * from "./proposerPreferences.js";
 export * from "./proposerSlashingError.js";
 export * from "./syncCommitteeError.js";
 export * from "./voluntaryExitError.js";

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

@@ -0,0 +1,39 @@
+import {Slot, ValidatorIndex} from "@lodestar/types";
+import {GossipActionError} from "./gossipValidation.js";
+
+export enum ProposerPreferencesErrorCode {
+  INVALID_EPOCH = "PROPOSER_PREFERENCES_ERROR_INVALID_EPOCH",
+  PROPOSAL_SLOT_PASSED = "PROPOSER_PREFERENCES_ERROR_PROPOSAL_SLOT_PASSED",
+  INVALID_PROPOSER = "PROPOSER_PREFERENCES_ERROR_INVALID_PROPOSER",
+  ALREADY_KNOWN = "PROPOSER_PREFERENCES_ERROR_ALREADY_KNOWN",
+  INVALID_SIGNATURE = "PROPOSER_PREFERENCES_ERROR_INVALID_SIGNATURE",
+}
+
+export type ProposerPreferencesErrorType =
+  | {
+      code: ProposerPreferencesErrorCode.INVALID_EPOCH;
+      proposalSlot: Slot;
+      currentEpoch: number;
+    }
+  | {
+      code: ProposerPreferencesErrorCode.PROPOSAL_SLOT_PASSED;
+      proposalSlot: Slot;
+      currentSlot: Slot;
+    }
+  | {
+      code: ProposerPreferencesErrorCode.INVALID_PROPOSER;
+      proposalSlot: Slot;
+      validatorIndex: ValidatorIndex;
+    }
+  | {
+      code: ProposerPreferencesErrorCode.ALREADY_KNOWN;
+      proposalSlot: Slot;
+      validatorIndex: ValidatorIndex;
+    }
+  | {
+      code: ProposerPreferencesErrorCode.INVALID_SIGNATURE;
+      proposalSlot: Slot;
+      validatorIndex: ValidatorIndex;
+    };
+
+export class ProposerPreferencesError extends GossipActionError<ProposerPreferencesErrorType> {}

packages/beacon-node/src/chain/interface.ts

@@ -61,6 +61,7 @@ import {
   SeenContributionAndProof,
   SeenExecutionPayloadBids,
   SeenPayloadAttesters,
+  SeenProposerPreferences,
   SeenSyncCommitteeMessages,
 } from "./seenCache/index.js";
 import {SeenAggregatedAttestations} from "./seenCache/seenAggregateAndProof.js";
@@ -131,6 +132,7 @@ export interface IBeaconChain {
   readonly seenPayloadAttesters: SeenPayloadAttesters;
   readonly seenAggregatedAttestations: SeenAggregatedAttestations;
   readonly seenExecutionPayloadBids: SeenExecutionPayloadBids;
+  readonly seenProposerPreferences: SeenProposerPreferences;
   readonly seenBlockProposers: SeenBlockProposers;
   readonly seenSyncCommitteeMessages: SeenSyncCommitteeMessages;
   readonly seenContributionAndProof: SeenContributionAndProof;

packages/beacon-node/src/chain/regen/interface.ts

@@ -21,6 +21,7 @@ export enum RegenCaller {
   validateGossipAttestation = "validateGossipAttestation",
   validateGossipVoluntaryExit = "validateGossipVoluntaryExit",
   validateGossipExecutionPayloadBid = "validateGossipExecutionPayloadBid",
+  validateGossipProposerPreferences = "validateGossipProposerPreferences",
   onForkChoiceFinalized = "onForkChoiceFinalized",
   restApi = "restApi",
 }

packages/beacon-node/src/chain/seenCache/index.ts

@@ -5,3 +5,4 @@ export {SeenContributionAndProof} from "./seenCommitteeContribution.js";
 export {SeenExecutionPayloadBids} from "./seenExecutionPayloadBids.js";
 export {SeenBlockInput} from "./seenGossipBlockInput.js";
 export {PayloadEnvelopeInput, SeenPayloadEnvelopeInput} from "./seenPayloadEnvelopeInput.js";
+export {SeenProposerPreferences} from "./seenProposerPreferences.js";

packages/beacon-node/src/chain/seenCache/seenProposerPreferences.ts

@@ -0,0 +1,29 @@
+import {Slot, ValidatorIndex} from "@lodestar/types";
+import {MapDef} from "@lodestar/utils";
+
+/**
+ * Tracks signed proposer preferences we've already seen per (proposal_slot, validator_index).
+ */
+export class SeenProposerPreferences {
+  private readonly validatorIndexesBySlot = new MapDef<Slot, Set<ValidatorIndex>>(() => new Set<ValidatorIndex>());
+
+  isKnown(proposalSlot: Slot, validatorIndex: ValidatorIndex): boolean {
+    return this.validatorIndexesBySlot.get(proposalSlot)?.has(validatorIndex) === true;
+  }
+
+  add(proposalSlot: Slot, validatorIndex: ValidatorIndex): void {
+    this.validatorIndexesBySlot.getOrDefault(proposalSlot).add(validatorIndex);
+  }
+
+  /**
+   * Entries are only load-bearing while `proposal_slot > state.slot`. Once the slot has passed the
+   * `[IGNORE] proposal_slot > state.slot` gossip rule takes over, so drop them on each slot tick.
+   */
+  prune(currentSlot: Slot): void {
+    for (const slot of this.validatorIndexesBySlot.keys()) {
+      if (slot < currentSlot) {
+        this.validatorIndexesBySlot.delete(slot);
+      }
+    }
+  }
+}

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

@@ -0,0 +1,91 @@
+import {SLOTS_PER_EPOCH} from "@lodestar/params";
+import {
+  computeEpochAtSlot,
+  createSingleSignatureSetFromComponents,
+  getProposerPreferencesSigningRoot,
+  isStatePostGloas,
+} from "@lodestar/state-transition";
+import {gloas} from "@lodestar/types";
+import {GossipAction, ProposerPreferencesError, ProposerPreferencesErrorCode} from "../errors/index.js";
+import {IBeaconChain} from "../index.js";
+import {RegenCaller} from "../regen/index.js";
+
+/**
+ * Validates a gossiped `SignedProposerPreferences` per
+ * https://github.com/ethereum/consensus-specs/blob/master/specs/gloas/p2p-interface.md#proposer_preferences
+ */
+export async function validateGossipProposerPreferences(
+  chain: IBeaconChain,
+  signedProposerPreferences: gloas.SignedProposerPreferences
+): Promise<void> {
+  const preferences = signedProposerPreferences.message;
+  const {proposalSlot, validatorIndex} = preferences;
+  const proposalEpoch = computeEpochAtSlot(proposalSlot);
+
+  // [IGNORE] `preferences.proposal_slot` is in the current or next epoch.
+  const currentEpoch = chain.clock.currentEpoch;
+  if (proposalEpoch < currentEpoch || proposalEpoch > currentEpoch + 1) {
+    throw new ProposerPreferencesError(GossipAction.IGNORE, {
+      code: ProposerPreferencesErrorCode.INVALID_EPOCH,
+      proposalSlot,
+      currentEpoch,
+    });
+  }
+
+  // [IGNORE] `preferences.proposal_slot` has not already passed.
+  const currentSlot = chain.clock.currentSlot;
+  if (proposalSlot <= currentSlot) {
+    throw new ProposerPreferencesError(GossipAction.IGNORE, {
+      code: ProposerPreferencesErrorCode.PROPOSAL_SLOT_PASSED,
+      proposalSlot,
+      currentSlot,
+    });
+  }
+
+  const state = await chain.getHeadStateAtCurrentEpoch(RegenCaller.validateGossipProposerPreferences);
+  if (!isStatePostGloas(state)) {
+    throw new Error(`Expected gloas+ state for proposer preferences validation, got fork=${state.forkName}`);
+  }
+
+  // [REJECT] `preferences.validator_index` is present at the correct slot in the current or next
+  // epoch's portion of `state.proposer_lookahead` — i.e. `is_valid_proposal_slot(state, preferences)`
+  // returns True.
+  const epochOffset = proposalEpoch - state.epoch;
+  const proposers = epochOffset === 0 ? state.currentProposers : state.nextProposers;
+  const expectedProposer = proposers[proposalSlot % SLOTS_PER_EPOCH];
+  if (epochOffset < 0 || epochOffset > 1 || expectedProposer !== validatorIndex) {
+    throw new ProposerPreferencesError(GossipAction.REJECT, {
+      code: ProposerPreferencesErrorCode.INVALID_PROPOSER,
+      proposalSlot,
+      validatorIndex,
+    });
+  }
+
+  // [IGNORE] The `signed_proposer_preferences` is the first valid message received from the validator
+  // with index `preferences.validator_index` and the given slot `preferences.proposal_slot`.
+  if (chain.seenProposerPreferences.isKnown(proposalSlot, validatorIndex)) {
+    throw new ProposerPreferencesError(GossipAction.IGNORE, {
+      code: ProposerPreferencesErrorCode.ALREADY_KNOWN,
+      proposalSlot,
+      validatorIndex,
+    });
+  }
+
+  // [REJECT] `signed_proposer_preferences.signature` is valid with respect to the validator's public key.
+  const signatureSet = createSingleSignatureSetFromComponents(
+    chain.pubkeyCache.getOrThrow(validatorIndex),
+    getProposerPreferencesSigningRoot(chain.config, preferences),
+    signedProposerPreferences.signature
+  );
+
+  if (!(await chain.bls.verifySignatureSets([signatureSet], {batchable: true}))) {
+    throw new ProposerPreferencesError(GossipAction.REJECT, {
+      code: ProposerPreferencesErrorCode.INVALID_SIGNATURE,
+      proposalSlot,
+      validatorIndex,
+    });
+  }
+
+  // Valid
+  chain.seenProposerPreferences.add(proposalSlot, validatorIndex);
+}

packages/beacon-node/src/network/gossip/interface.ts

@@ -41,6 +41,7 @@ export enum GossipType {
   execution_payload = "execution_payload",
   payload_attestation_message = "payload_attestation_message",
   execution_payload_bid = "execution_payload_bid",
+  proposer_preferences = "proposer_preferences",
 }
 
 export type SequentialGossipType = Exclude<GossipType, GossipType.beacon_attestation>;
@@ -78,6 +79,7 @@ export type GossipTopicTypeMap = {
   [GossipType.execution_payload]: {type: GossipType.execution_payload};
   [GossipType.payload_attestation_message]: {type: GossipType.payload_attestation_message};
   [GossipType.execution_payload_bid]: {type: GossipType.execution_payload_bid};
+  [GossipType.proposer_preferences]: {type: GossipType.proposer_preferences};
 };
 
 export type GossipTopicMap = {
@@ -110,6 +112,7 @@ export type GossipTypeMap = {
   [GossipType.execution_payload]: gloas.SignedExecutionPayloadEnvelope;
   [GossipType.payload_attestation_message]: gloas.PayloadAttestationMessage;
   [GossipType.execution_payload_bid]: gloas.SignedExecutionPayloadBid;
+  [GossipType.proposer_preferences]: gloas.SignedProposerPreferences;
 };
 
 export type GossipFnByType = {
@@ -141,6 +144,9 @@ export type GossipFnByType = {
     payloadAttestationMessage: gloas.PayloadAttestationMessage
   ) => Promise<void> | void;
   [GossipType.execution_payload_bid]: (executionPayloadBid: gloas.SignedExecutionPayloadBid) => Promise<void> | void;
+  [GossipType.proposer_preferences]: (
+    signedProposerPreferences: gloas.SignedProposerPreferences
+  ) => Promise<void> | void;
 };
 
 export type GossipFn = GossipFnByType[keyof GossipFnByType];

packages/beacon-node/src/network/gossip/scoringParameters.ts

@@ -27,6 +27,7 @@ const BLS_TO_EXECUTION_CHANGE_WEIGHT = 0.05;
 const EXECUTION_PAYLOAD_WEIGHT = 0.5;
 const PAYLOAD_ATTESTATION_WEIGHT = 0.05;
 const EXECUTION_PAYLOAD_BID_WEIGHT = 0.05;
+const PROPOSER_PREFERENCES_WEIGHT = 0.05;
 
 const beaconAttestationSubnetWeight = 1 / ATTESTATION_SUBNET_COUNT;
 const maxPositiveScore =
@@ -40,7 +41,8 @@ const maxPositiveScore =
     BLS_TO_EXECUTION_CHANGE_WEIGHT +
     EXECUTION_PAYLOAD_WEIGHT +
     PAYLOAD_ATTESTATION_WEIGHT +
-    EXECUTION_PAYLOAD_BID_WEIGHT);
+    EXECUTION_PAYLOAD_BID_WEIGHT +
+    PROPOSER_PREFERENCES_WEIGHT);
 
 /**
  * The following params is implemented by Lighthouse at
@@ -198,6 +200,17 @@ function getAllTopicsScoreParams(
       expectedMessageRate: 1024, // TODO GLOAS: Need an estimate for this
       firstMessageDecayTime: epochDurationMs * 100,
     });
+    topicsParams[
+      stringifyGossipTopic(config, {
+        type: GossipType.proposer_preferences,
+        boundary,
+      })
+    ] = getTopicScoreParams(config, precomputedParams, {
+      topicWeight: PROPOSER_PREFERENCES_WEIGHT,
+      // Upper bound ~64 messages per epoch: one per proposer across the current + next epoch.
+      expectedMessageRate: 64 / SLOTS_PER_EPOCH,
+      firstMessageDecayTime: epochDurationMs * 100,
+    });
 
     // other topics
     topicsParams[

packages/beacon-node/src/network/gossip/topic.ts

@@ -73,6 +73,7 @@ function stringifyGossipTopicType(topic: GossipTopic): string {
     case GossipType.execution_payload:
     case GossipType.payload_attestation_message:
     case GossipType.execution_payload_bid:
+    case GossipType.proposer_preferences:
       return topic.type;
     case GossipType.beacon_attestation:
     case GossipType.sync_committee:
@@ -124,6 +125,8 @@ export function getGossipSSZType(topic: GossipTopic) {
       return ssz.gloas.PayloadAttestationMessage;
     case GossipType.execution_payload_bid:
       return ssz.gloas.SignedExecutionPayloadBid;
+    case GossipType.proposer_preferences:
+      return ssz.gloas.SignedProposerPreferences;
   }
 }
 
@@ -203,6 +206,7 @@ export function parseGossipTopic(forkDigestContext: ForkDigestContext, topicStr:
       case GossipType.execution_payload:
       case GossipType.payload_attestation_message:
       case GossipType.execution_payload_bid:
+      case GossipType.proposer_preferences:
         return {type: gossipTypeStr, boundary, encoding};
     }
 
@@ -257,6 +261,7 @@ export function getCoreTopicsAtFork(
     topics.push({type: GossipType.execution_payload});
     topics.push({type: GossipType.payload_attestation_message});
     topics.push({type: GossipType.execution_payload_bid});
+    topics.push({type: GossipType.proposer_preferences});
   }
 
   // After fulu also track data_column_sidecar_{index}
@@ -351,4 +356,5 @@ export const gossipTopicIgnoreDuplicatePublishError: Record<GossipType, boolean>
   [GossipType.execution_payload]: true,
   [GossipType.payload_attestation_message]: true,
   [GossipType.execution_payload_bid]: true,
+  [GossipType.proposer_preferences]: true,
 };

packages/beacon-node/src/network/processor/gossipHandlers.ts

@@ -79,6 +79,7 @@ import {
 import {validateLightClientFinalityUpdate} from "../../chain/validation/lightClientFinalityUpdate.js";
 import {validateLightClientOptimisticUpdate} from "../../chain/validation/lightClientOptimisticUpdate.js";
 import {validateGossipPayloadAttestationMessage} from "../../chain/validation/payloadAttestationMessage.js";
+import {validateGossipProposerPreferences} from "../../chain/validation/proposerPreferences.js";
 import {OpSource} from "../../chain/validatorMonitor.js";
 import {Metrics} from "../../metrics/index.js";
 import {kzgCommitmentToVersionedHash} from "../../util/blobs.js";
@@ -1170,6 +1171,14 @@ function getSequentialHandlers(modules: ValidatorFnsModules, options: GossipHand
         data: executionPayloadBid,
       });
     },
+    [GossipType.proposer_preferences]: async ({
+      gossipData,
+      topic,
+    }: GossipHandlerParamGeneric<GossipType.proposer_preferences>) => {
+      const {serializedData} = gossipData;
+      const signedProposerPreferences = sszDeserialize(topic, serializedData);
+      await validateGossipProposerPreferences(chain, signedProposerPreferences);
+    },
   };
 }
 

packages/beacon-node/src/network/processor/gossipQueues/index.ts

@@ -83,6 +83,11 @@ const linearGossipQueueOpts: {
     type: QueueType.FIFO,
     dropOpts: {type: DropType.count, count: 1},
   },
+  [GossipType.proposer_preferences]: {
+    maxLength: 1024,
+    type: QueueType.FIFO,
+    dropOpts: {type: DropType.count, count: 1},
+  },
 };
 
 const indexedGossipQueueOpts: {

packages/beacon-node/src/network/processor/index.ts

@@ -91,6 +91,7 @@ const executeGossipWorkOrderObj: Record<GossipType, WorkOpts> = {
   [GossipType.execution_payload]: {bypassQueue: true},
   [GossipType.payload_attestation_message]: {},
   [GossipType.execution_payload_bid]: {},
+  [GossipType.proposer_preferences]: {},
 };
 const executeGossipWorkOrder = Object.keys(executeGossipWorkOrderObj) as (keyof typeof executeGossipWorkOrderObj)[];