fix(p2p): fall back to maxTxsPerCheckpoint for per-block tx validation

yarn-project/p2p/src/config.ts

@@ -43,6 +43,9 @@ export interface P2PConfig
   /** Maximum transactions per block for validation. Overrides maxTxsPerBlock for gossip validation when set. */
   validateMaxTxsPerBlock?: number;
 
+  /** Maximum transactions per checkpoint for validation. Used as fallback for maxTxsPerBlock when that is not set. */
+  validateMaxTxsPerCheckpoint?: number;
+
   /** Maximum L2 gas per block for validation. When set, txs exceeding this limit are rejected. */
   validateMaxL2BlockGas?: number;
 
@@ -214,6 +217,12 @@ export const p2pConfigMappings: ConfigMappingsType<P2PConfig> = {
       'Maximum transactions per block for validation. Overrides maxTxsPerBlock for gossip validation when set.',
     parseEnv: (val: string) => (val ? parseInt(val, 10) : undefined),
   },
+  validateMaxTxsPerCheckpoint: {
+    env: 'VALIDATOR_MAX_TX_PER_CHECKPOINT',
+    description:
+      'Maximum transactions per checkpoint for validation. Used as fallback for maxTxsPerBlock when that is not set.',
+    parseEnv: (val: string) => (val ? parseInt(val, 10) : undefined),
+  },
   validateMaxL2BlockGas: {
     env: 'VALIDATOR_MAX_L2_BLOCK_GAS',
     description: 'Maximum L2 gas per block for validation. When set, txs exceeding this limit are rejected.',

yarn-project/p2p/src/services/libp2p/libp2p_service.ts

@@ -226,7 +226,7 @@ export class LibP2PService extends WithTracer implements P2PService {
 
     const proposalValidatorOpts = {
       txsPermitted: !config.disableTransactions,
-      maxTxsPerBlock: config.validateMaxTxsPerBlock,
+      maxTxsPerBlock: config.validateMaxTxsPerBlock ?? config.validateMaxTxsPerCheckpoint,
     };
     this.blockProposalValidator = new BlockProposalValidator(epochCache, proposalValidatorOpts);
     this.checkpointProposalValidator = new CheckpointProposalValidator(epochCache, proposalValidatorOpts);

yarn-project/validator-client/src/factory.ts

@@ -29,7 +29,7 @@ export function createBlockProposalHandler(
   const metrics = new ValidatorMetrics(deps.telemetry);
   const blockProposalValidator = new BlockProposalValidator(deps.epochCache, {
     txsPermitted: !config.disableTransactions,
-    maxTxsPerBlock: config.validateMaxTxsPerBlock,
+    maxTxsPerBlock: config.validateMaxTxsPerBlock ?? config.validateMaxTxsPerCheckpoint,
   });
   return new BlockProposalHandler(
     deps.checkpointsBuilder,