cmd/devp2p: add duplicated tx test

cmd/devp2p/internal/ethtest/suite.go

@@ -90,6 +90,7 @@ func (s *Suite) EthTests() []utesting.Test {
 		{Name: "BlobViolations", Fn: s.TestBlobViolations},
 		{Name: "TestBlobTxWithoutSidecar", Fn: s.TestBlobTxWithoutSidecar},
 		{Name: "TestBlobTxWithMismatchedSidecar", Fn: s.TestBlobTxWithMismatchedSidecar},
+		{Name: "DuplicateTxs", Fn: s.TestDuplicateTxs},
 	}
 }
 
@@ -1187,3 +1188,32 @@ func (s *Suite) testBadBlobTx(t *utesting.T, tx *types.Transaction, badTx *types
 		t.Fatalf("%v", err)
 	}
 }
+
+func (s *Suite) TestDuplicateTxs(t *utesting.T) {
+	t.Log(`This test sends a TransactionsMsg containing duplicate transactions and expects the node to disconnect.`)
+
+	// Nudge client out of syncing mode to accept pending txs.
+	if err := s.engine.sendForkchoiceUpdated(); err != nil {
+		t.Fatalf("failed to send next block: %v", err)
+	}
+
+	from, nonce := s.chain.GetSender(0)
+	inner := &types.DynamicFeeTx{
+		ChainID:   s.chain.config.ChainID,
+		Nonce:     nonce,
+		GasTipCap: common.Big1,
+		GasFeeCap: s.chain.Head().BaseFee(),
+		Gas:       30000,
+		To:        &common.Address{0xaa},
+		Value:     common.Big1,
+	}
+	tx, err := s.chain.SignTx(from, types.NewTx(inner))
+	if err != nil {
+		t.Fatalf("failed to sign tx: %v", err)
+	}
+
+	txs := []*types.Transaction{tx, tx}
+	if err := s.sendDuplicateTxsInOneMsg(t, txs); err != nil {
+		t.Fatal(err)
+	}
+}

cmd/devp2p/internal/ethtest/transaction.go

@@ -176,3 +176,31 @@ func (s *Suite) sendInvalidTxs(t *utesting.T, txs []*types.Transaction) error {
 		}
 	}
 }
+
+// sendDuplicateTxsInOneMsg sends a transaction slice containing duplicates
+// in a single TransactionsMsg and expects the node to disconnect.
+func (s *Suite) sendDuplicateTxsInOneMsg(t *utesting.T, txs []*types.Transaction) error {
+	conn, err := s.dial()
+	if err != nil {
+		return fmt.Errorf("dial failed: %v", err)
+	}
+	defer conn.Close()
+
+	if err = conn.peer(s.chain, nil); err != nil {
+		return fmt.Errorf("peering failed: %v", err)
+	}
+
+	if err = conn.Write(ethProto, eth.TransactionsMsg, eth.TransactionsPacket(txs)); err != nil {
+		return fmt.Errorf("failed to write message to connection: %v", err)
+	}
+
+	// Expect disconnect.
+	code, _, err := conn.Read()
+	if err != nil {
+		return fmt.Errorf("error reading from connection: %v", err)
+	}
+	if code != discMsg {
+		return fmt.Errorf("expected disconnect, got msg code %d", code)
+	}
+	return nil
+}