consensus, core, eth/downloader, params: 4844 chain validation (#27382)

eth/downloader/queue.go

@@ -31,6 +31,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 const (
@@ -796,6 +797,21 @@ func (q *queue) DeliverBodies(id string, txLists [][]*types.Transaction, txListH
 				return errInvalidBody
 			}
 		}
+		// Blocks must have a number of blobs corresponding to the header gas usage,
+		// and zero before the Cancun hardfork
+		var blobs int
+		for _, tx := range txLists[index] {
+			blobs += len(tx.BlobHashes())
+		}
+		if header.DataGasUsed != nil {
+			if want := *header.DataGasUsed / params.BlobTxDataGasPerBlob; uint64(blobs) != want { // div because the header is surely good vs the body might be bloated
+				return errInvalidBody
+			}
+		} else {
+			if blobs != 0 {
+				return errInvalidBody
+			}
+		}
 		return nil
 	}