fix

proxy/trojan/protocol.go

@@ -140,6 +140,7 @@ func (w *PacketWriter) writePacket(payload []byte, dest net.Destination) (int, e
 	binary.BigEndian.PutUint16(lengthBuf[:], uint16(length))
 
 	addrPortBuf := buf.StackNew()
+	defer addrPortBuf.Release()
 	if err := addrParser.WriteAddressPort(&addrPortBuf, dest.Address, dest.Port); err != nil {
 		return 0, err
 	}
@@ -150,7 +151,6 @@ func (w *PacketWriter) writePacket(payload []byte, dest net.Destination) (int, e
 	if _, err := buffer.Write(addrPortBuf.Bytes()); err != nil {
 		return 0, err
 	}
-	addrPortBuf.Release()
 	if _, err := buffer.Write(lengthBuf[:]); err != nil {
 		return 0, err
 	}

proxy/trojan/protocol_test.go

@@ -1,6 +1,7 @@
 package trojan_test
 
 import (
+	"crypto/rand"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -90,3 +91,48 @@ func TestUDPRequest(t *testing.T) {
 		t.Error("data: ", r)
 	}
 }
+
+func TestLargeUDPRequest(t *testing.T) {
+	user := &protocol.MemoryUser{
+		Email: "[email protected]",
+		Account: toAccount(&Account{
+			Password: "password",
+		}),
+	}
+
+	payload := make([]byte, 4096)
+	common.Must2(rand.Read(payload))
+	data := buf.NewWithSize(int32(len(payload)))
+	common.Must2(data.Write(payload))
+
+	buffer := buf.NewWithSize(2*data.Len() + 1)
+	defer buffer.Release()
+
+	destination := net.Destination{Network: net.Network_UDP, Address: net.LocalHostIP, Port: 1234}
+	writer := &PacketWriter{Writer: &ConnWriter{Writer: buffer, Target: destination, Account: user.Account.(*MemoryAccount)}, Target: destination}
+	common.Must(writer.WriteMultiBuffer(buf.MultiBuffer{data, data}))
+
+	connReader := &ConnReader{Reader: buffer}
+	common.Must(connReader.ParseHeader())
+
+	packetReader := &PacketReader{Reader: connReader}
+	for i := 0; i < 2; i++ {
+		p, err := packetReader.ReadMultiBufferWithMetadata()
+		common.Must(err)
+
+		if p.Buffer.IsEmpty() {
+			t.Error("no request data")
+		}
+
+		if r := cmp.Diff(p.Target, destination); r != "" {
+			t.Error("destination: ", r)
+		}
+
+		mb, decoded := buf.SplitFirst(p.Buffer)
+		buf.ReleaseMulti(mb)
+
+		if r := cmp.Diff(decoded.Bytes(), payload); r != "" {
+			t.Error("data: ", r)
+		}
+	}
+}