From d11ef8b62472edc6574a64798c849465a75cbe85 Mon Sep 17 00:00:00 2001
From: Jared Wasinger <j-wasinger@hotmail.com>
Date: Mon, 9 Jun 2025 13:41:48 +0200
Subject: [PATCH] core,miner,params: implement EIP-7934 - RLP Execution Block
 Size Limit

---
 core/block_validator.go   |  3 +++
 core/error.go             |  4 ++++
 miner/worker.go           | 12 ++++++++++++
 params/protocol_params.go |  2 ++
 4 files changed, 21 insertions(+)

diff --git a/core/block_validator.go b/core/block_validator.go
index 591e472bc1..a25fb7e69e 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -49,6 +49,9 @@ func NewBlockValidator(config *params.ChainConfig, blockchain *BlockChain) *Bloc
 // header's transaction and uncle roots. The headers are assumed to be already
 // validated at this point.
 func (v *BlockValidator) ValidateBody(block *types.Block) error {
+	if v.config.IsOsaka(block.Number(), block.Time()) && block.Size() > params.BlockRLPSizeCap {
+		return ErrBlockOversized
+	}
 	// Check whether the block is already imported.
 	if v.bc.HasBlockAndState(block.Hash(), block.NumberU64()) {
 		return ErrKnownBlock
diff --git a/core/error.go b/core/error.go
index de95e64636..e50780bf1b 100644
--- a/core/error.go
+++ b/core/error.go
@@ -28,6 +28,10 @@ var (
 
 	// ErrNoGenesis is returned when there is no Genesis Block.
 	ErrNoGenesis = errors.New("genesis not found in chain")
+
+	// ErrBlockOversized is returned if the size of the RLP-encoded block
+	// exceeds the cap established by EIP 7934
+	ErrBlockOversized = errors.New("block RLP-encoded size exceeds maximum")
 )
 
 // List of evm-call-message pre-checking errors. All state transition messages will
diff --git a/miner/worker.go b/miner/worker.go
index 198745ad27..09cd94aa46 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -19,6 +19,7 @@ package miner
 import (
 	"errors"
 	"fmt"
+	"github.com/ethereum/go-ethereum/trie"
 	"math/big"
 	"sync/atomic"
 	"time"
@@ -94,6 +95,13 @@ type generateParams struct {
 	noTxs       bool              // Flag whether an empty block without any transaction is expected
 }
 
+func (env *environment) encodedSizeWithTxAndReceipt(tx *types.Transaction) uint64 {
+	body := types.Body{Transactions: append(env.txs, tx), Withdrawals: make([]*types.Withdrawal, 0)}
+	env.header.RequestsHash = &common.Hash{}
+	block := types.NewBlock(env.header, &body, env.receipts, trie.NewStackTrie(nil))
+	return block.Size()
+}
+
 // generateWork generates a sealing block based on the given parameters.
 func (miner *Miner) generateWork(params *generateParams, witness bool) *newPayloadResult {
 	work, err := miner.prepareWork(params, witness)
@@ -391,6 +399,10 @@ func (miner *Miner) commitTransactions(env *environment, plainTxs, blobTxs *tran
 			continue
 		}
 
+		if miner.chainConfig.IsOsaka(env.header.Number, env.header.Time) && env.encodedSizeWithTxAndReceipt(tx) > params.BlockRLPSizeCap {
+			break
+		}
+
 		// Make sure all transactions after osaka have cell proofs
 		if miner.chainConfig.IsOsaka(env.header.Number, env.header.Time) {
 			if sidecar := tx.BlobTxSidecar(); sidecar != nil {
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 3676a7bdf1..029a52c5f3 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -178,6 +178,8 @@ const (
 	BlobBaseCost                       = 1 << 13 // Base execution gas cost for a blob.
 
 	HistoryServeWindow = 8192 // Number of blocks to serve historical block hashes for, EIP-2935.
+
+	BlockRLPSizeCap = 9_961_472 // maximum size of an RLP-encoded block
 )
 
 // Bls12381G1MultiExpDiscountTable is the gas discount table for BLS12-381 G1 multi exponentiation operation