mKCP transport: Add cwndMultiplier; Apply unaggressive strategy by default (#5890)

https://github.com/XTLS/Xray-core/issues/4846#issuecomment-4150329444

https://github.com/XTLS/Xray-core/pull/5872#issuecomment-4184774915

https://github.com/XTLS/Xray-core/pull/5890#issuecomment-4240052251

infra/conf/transport_internet.go

@@ -14,6 +14,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/platform/filesystem"
@@ -54,64 +55,57 @@ var (
 )
 
 type KCPConfig struct {
-	Mtu             *uint32         `json:"mtu"`
+	Mtu              *uint32 `json:"mtu"`
-	Tti             *uint32         `json:"tti"`
+	Tti              *uint32 `json:"tti"`
-	UpCap           *uint32         `json:"uplinkCapacity"`
+	UpCap            *uint32 `json:"uplinkCapacity"`
-	DownCap         *uint32         `json:"downlinkCapacity"`
+	DownCap          *uint32 `json:"downlinkCapacity"`
-	Congestion      *bool           `json:"congestion"`
+	CwndMultiplier   *uint32 `json:"cwndMultiplier"`
-	ReadBufferSize  *uint32         `json:"readBufferSize"`
+	MaxSendingWindow *uint32 `json:"maxSendingWindow"`
-	WriteBufferSize *uint32         `json:"writeBufferSize"`
+
-	HeaderConfig    json.RawMessage `json:"header"`
+	HeaderConfig json.RawMessage `json:"header"`
-	Seed            *string         `json:"seed"`
+	Seed         *string         `json:"seed"`
 }
 
 // Build implements Buildable.
 func (c *KCPConfig) Build() (proto.Message, error) {
-	config := new(kcp.Config)
-
-	if c.Mtu != nil {
-		mtu := *c.Mtu
-		// if mtu < 576 || mtu > 1460 {
-		// 	return nil, errors.New("invalid mKCP MTU size: ", mtu).AtError()
-		// }
-		config.Mtu = &kcp.MTU{Value: mtu}
-	}
-	if c.Tti != nil {
-		tti := *c.Tti
-		if tti < 10 || tti > 5000 {
-			return nil, errors.New("invalid mKCP TTI: ", tti).AtError()
-		}
-		config.Tti = &kcp.TTI{Value: tti}
-	}
-	if c.UpCap != nil {
-		config.UplinkCapacity = &kcp.UplinkCapacity{Value: *c.UpCap}
-	}
-	if c.DownCap != nil {
-		config.DownlinkCapacity = &kcp.DownlinkCapacity{Value: *c.DownCap}
-	}
-	if c.Congestion != nil {
-		config.Congestion = *c.Congestion
-	}
-	if c.ReadBufferSize != nil {
-		size := *c.ReadBufferSize
-		if size > 0 {
-			config.ReadBuffer = &kcp.ReadBuffer{Size: size * 1024 * 1024}
-		} else {
-			config.ReadBuffer = &kcp.ReadBuffer{Size: 512 * 1024}
-		}
-	}
-	if c.WriteBufferSize != nil {
-		size := *c.WriteBufferSize
-		if size > 0 {
-			config.WriteBuffer = &kcp.WriteBuffer{Size: size * 1024 * 1024}
-		} else {
-			config.WriteBuffer = &kcp.WriteBuffer{Size: 512 * 1024}
-		}
-	}
 	if c.HeaderConfig != nil || c.Seed != nil {
 		return nil, errors.PrintRemovedFeatureError("mkcp header & seed", "finalmask/udp header-* & mkcp-original & mkcp-aes128gcm")
 	}
 
+	config := common.Must2(internet.CreateTransportConfig(kcp.ProtocolName)).(*kcp.Config)
+
+	if c.Mtu != nil {
+		config.Mtu = *c.Mtu
+	}
+	if c.Tti != nil {
+		config.Tti = *c.Tti
+	}
+	if c.UpCap != nil {
+		config.UplinkCapacity = *c.UpCap
+	}
+	if c.DownCap != nil {
+		config.DownlinkCapacity = *c.DownCap
+	}
+	if c.CwndMultiplier != nil {
+		config.CwndMultiplier = *c.CwndMultiplier
+	}
+	if c.MaxSendingWindow != nil {
+		config.MaxSendingWindow = *c.MaxSendingWindow
+	}
+
+	if config.Mtu < 21 {
+		return nil, errors.New("Mtu must be at least 21").AtError()
+	}
+	if config.Tti < 10 || config.Tti > 1000 {
+		return nil, errors.New("invalid mKCP TTI: ", c.Tti).AtError()
+	}
+	if config.CwndMultiplier < 1 {
+		return nil, errors.New("CwndMultiplier must be at least 1").AtError()
+	}
+	if config.GetSendingBufferSize() == 0 {
+		return nil, errors.New("MaxSendingWindow must be >= Mtu").AtError()
+	}
+
 	return config, nil
 }
 

testing/scenarios/vmess_test.go

@@ -22,7 +22,6 @@ import (
 	"github.com/xtls/xray-core/testing/servers/tcp"
 	"github.com/xtls/xray-core/testing/servers/udp"
 	"github.com/xtls/xray-core/transport/internet"
-	"github.com/xtls/xray-core/transport/internet/kcp"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -94,9 +93,9 @@ func TestVMessGCM(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
-								Id:               userID.String(),
+								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
 									Type: protocol.SecurityType_AES128_GCM,
 								},
@@ -192,9 +191,9 @@ func TestVMessGCMReadv(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
-								Id:               userID.String(),
+								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
 									Type: protocol.SecurityType_AES128_GCM,
 								},
@@ -293,9 +292,9 @@ func TestVMessGCMUDP(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
-								Id:               userID.String(),
+								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
 									Type: protocol.SecurityType_AES128_GCM,
 								},
@@ -388,9 +387,9 @@ func TestVMessChacha20(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
-								Id:               userID.String(),
+								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
 									Type: protocol.SecurityType_CHACHA20_POLY1305,
 								},
@@ -484,7 +483,7 @@ func TestVMessNone(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -638,25 +637,6 @@ func TestVMessKCPLarge(t *testing.T) {
 					Listen:   net.NewIPOrDomain(net.LocalHostIP),
 					StreamSettings: &internet.StreamConfig{
 						ProtocolName: "mkcp",
-						TransportSettings: []*internet.TransportConfig{
-							{
-								ProtocolName: "mkcp",
-								Settings: serial.ToTypedMessage(&kcp.Config{
-									ReadBuffer: &kcp.ReadBuffer{
-										Size: 512 * 1024,
-									},
-									WriteBuffer: &kcp.WriteBuffer{
-										Size: 512 * 1024,
-									},
-									UplinkCapacity: &kcp.UplinkCapacity{
-										Value: 20,
-									},
-									DownlinkCapacity: &kcp.DownlinkCapacity{
-										Value: 20,
-									},
-								}),
-							},
-						},
 					},
 				}),
 				ProxySettings: serial.ToTypedMessage(&inbound.Config{
@@ -704,7 +684,7 @@ func TestVMessKCPLarge(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -717,25 +697,6 @@ func TestVMessKCPLarge(t *testing.T) {
 				SenderSettings: serial.ToTypedMessage(&proxyman.SenderConfig{
 					StreamSettings: &internet.StreamConfig{
 						ProtocolName: "mkcp",
-						TransportSettings: []*internet.TransportConfig{
-							{
-								ProtocolName: "mkcp",
-								Settings: serial.ToTypedMessage(&kcp.Config{
-									ReadBuffer: &kcp.ReadBuffer{
-										Size: 512 * 1024,
-									},
-									WriteBuffer: &kcp.WriteBuffer{
-										Size: 512 * 1024,
-									},
-									UplinkCapacity: &kcp.UplinkCapacity{
-										Value: 20,
-									},
-									DownlinkCapacity: &kcp.DownlinkCapacity{
-										Value: 20,
-									},
-								}),
-							},
-						},
 					},
 				}),
 			},
@@ -833,7 +794,7 @@ func TestVMessGCMMux(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -956,7 +917,7 @@ func TestVMessGCMMuxUDP(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -1059,7 +1020,7 @@ func TestVMessZero(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -1154,7 +1115,7 @@ func TestVMessGCMLengthAuth(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{
@@ -1254,7 +1215,7 @@ func TestVMessGCMLengthAuthPlusNoTerminationSignal(t *testing.T) {
 					Receiver: &protocol.ServerEndpoint{
 						Address: net.NewIPOrDomain(net.LocalHostIP),
 						Port:    uint32(serverPort),
-						User:    &protocol.User{
+						User: &protocol.User{
 							Account: serial.ToTypedMessage(&vmess.Account{
 								Id: userID.String(),
 								SecuritySettings: &protocol.SecurityConfig{

transport/internet/hysteria/config.go

@@ -48,6 +48,8 @@ const protocolName = "hysteria"
 
 func init() {
 	common.Must(internet.RegisterProtocolConfigCreator(protocolName, func() interface{} {
-		return new(Config)
+		return &Config{
+			UdpIdleTimeout: 60,
+		}
 	}))
 }

transport/internet/kcp/config.go

@@ -5,56 +5,8 @@ import (
 	"github.com/xtls/xray-core/transport/internet"
 )
 
-// GetMTUValue returns the value of MTU settings.
-func (c *Config) GetMTUValue() uint32 {
-	if c == nil || c.Mtu == nil {
-		return 1350
-	}
-	return c.Mtu.Value
-}
-
-// GetTTIValue returns the value of TTI settings.
-func (c *Config) GetTTIValue() uint32 {
-	if c == nil || c.Tti == nil {
-		return 50
-	}
-	return c.Tti.Value
-}
-
-// GetUplinkCapacityValue returns the value of UplinkCapacity settings.
-func (c *Config) GetUplinkCapacityValue() uint32 {
-	if c == nil || c.UplinkCapacity == nil {
-		return 5
-	}
-	return c.UplinkCapacity.Value
-}
-
-// GetDownlinkCapacityValue returns the value of DownlinkCapacity settings.
-func (c *Config) GetDownlinkCapacityValue() uint32 {
-	if c == nil || c.DownlinkCapacity == nil {
-		return 20
-	}
-	return c.DownlinkCapacity.Value
-}
-
-// GetWriteBufferSize returns the size of WriterBuffer in bytes.
-func (c *Config) GetWriteBufferSize() uint32 {
-	if c == nil || c.WriteBuffer == nil {
-		return 2 * 1024 * 1024
-	}
-	return c.WriteBuffer.Size
-}
-
-// GetReadBufferSize returns the size of ReadBuffer in bytes.
-// func (c *Config) GetReadBufferSize() uint32 {
-// 	if c == nil || c.ReadBuffer == nil {
-// 		return 2 * 1024 * 1024
-// 	}
-// 	return c.ReadBuffer.Size
-// }
-
 func (c *Config) GetSendingInFlightSize() uint32 {
-	size := c.GetUplinkCapacityValue() * 1024 * 1024 / c.GetMTUValue() / (1000 / c.GetTTIValue())
+	size := c.UplinkCapacity * 1024 * 1024 / c.Mtu / (1000 / c.Tti)
 	if size < 8 {
 		size = 8
 	}
@@ -62,23 +14,26 @@ func (c *Config) GetSendingInFlightSize() uint32 {
 }
 
 func (c *Config) GetSendingBufferSize() uint32 {
-	return c.GetWriteBufferSize() / c.GetMTUValue()
+	return c.MaxSendingWindow / c.Mtu
 }
 
 func (c *Config) GetReceivingInFlightSize() uint32 {
-	size := c.GetDownlinkCapacityValue() * 1024 * 1024 / c.GetMTUValue() / (1000 / c.GetTTIValue())
+	size := c.DownlinkCapacity * 1024 * 1024 / c.Mtu / (1000 / c.Tti)
 	if size < 8 {
 		size = 8
 	}
 	return size
 }
 
-// func (c *Config) GetReceivingBufferSize() uint32 {
-// 	return c.GetReadBufferSize() / c.GetMTUValue()
-// }
-
 func init() {
-	common.Must(internet.RegisterProtocolConfigCreator(protocolName, func() interface{} {
+	common.Must(internet.RegisterProtocolConfigCreator(ProtocolName, func() interface{} {
-		return new(Config)
+		return &Config{
+			Mtu:              1350,
+			Tti:              50,
+			UplinkCapacity:   5,
+			DownlinkCapacity: 20,
+			CwndMultiplier:   1,
+			MaxSendingWindow: 2 * 1024 * 1024,
+		}
 	}))
 }

transport/internet/kcp/config.pb.go

@@ -7,7 +7,6 @@
 package kcp
 
 import (
-	serial "github.com/xtls/xray-core/common/serial"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
@@ -22,385 +21,21 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
-// Maximum Transmission Unit, in bytes.
-type MTU struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Value         uint32                 `protobuf:"varint,1,opt,name=value,proto3" json:"value,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *MTU) Reset() {
-	*x = MTU{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[0]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *MTU) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*MTU) ProtoMessage() {}
-
-func (x *MTU) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[0]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use MTU.ProtoReflect.Descriptor instead.
-func (*MTU) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{0}
-}
-
-func (x *MTU) GetValue() uint32 {
-	if x != nil {
-		return x.Value
-	}
-	return 0
-}
-
-// Transmission Time Interview, in milli-sec.
-type TTI struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Value         uint32                 `protobuf:"varint,1,opt,name=value,proto3" json:"value,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *TTI) Reset() {
-	*x = TTI{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[1]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *TTI) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*TTI) ProtoMessage() {}
-
-func (x *TTI) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[1]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use TTI.ProtoReflect.Descriptor instead.
-func (*TTI) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{1}
-}
-
-func (x *TTI) GetValue() uint32 {
-	if x != nil {
-		return x.Value
-	}
-	return 0
-}
-
-// Uplink capacity, in MB.
-type UplinkCapacity struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Value         uint32                 `protobuf:"varint,1,opt,name=value,proto3" json:"value,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *UplinkCapacity) Reset() {
-	*x = UplinkCapacity{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[2]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *UplinkCapacity) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*UplinkCapacity) ProtoMessage() {}
-
-func (x *UplinkCapacity) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[2]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use UplinkCapacity.ProtoReflect.Descriptor instead.
-func (*UplinkCapacity) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{2}
-}
-
-func (x *UplinkCapacity) GetValue() uint32 {
-	if x != nil {
-		return x.Value
-	}
-	return 0
-}
-
-// Downlink capacity, in MB.
-type DownlinkCapacity struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Value         uint32                 `protobuf:"varint,1,opt,name=value,proto3" json:"value,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *DownlinkCapacity) Reset() {
-	*x = DownlinkCapacity{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[3]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *DownlinkCapacity) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*DownlinkCapacity) ProtoMessage() {}
-
-func (x *DownlinkCapacity) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[3]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use DownlinkCapacity.ProtoReflect.Descriptor instead.
-func (*DownlinkCapacity) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{3}
-}
-
-func (x *DownlinkCapacity) GetValue() uint32 {
-	if x != nil {
-		return x.Value
-	}
-	return 0
-}
-
-type WriteBuffer struct {
-	state protoimpl.MessageState `protogen:"open.v1"`
-	// Buffer size in bytes.
-	Size          uint32 `protobuf:"varint,1,opt,name=size,proto3" json:"size,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *WriteBuffer) Reset() {
-	*x = WriteBuffer{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[4]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *WriteBuffer) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*WriteBuffer) ProtoMessage() {}
-
-func (x *WriteBuffer) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[4]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use WriteBuffer.ProtoReflect.Descriptor instead.
-func (*WriteBuffer) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{4}
-}
-
-func (x *WriteBuffer) GetSize() uint32 {
-	if x != nil {
-		return x.Size
-	}
-	return 0
-}
-
-type ReadBuffer struct {
-	state protoimpl.MessageState `protogen:"open.v1"`
-	// Buffer size in bytes.
-	Size          uint32 `protobuf:"varint,1,opt,name=size,proto3" json:"size,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *ReadBuffer) Reset() {
-	*x = ReadBuffer{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[5]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *ReadBuffer) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*ReadBuffer) ProtoMessage() {}
-
-func (x *ReadBuffer) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[5]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use ReadBuffer.ProtoReflect.Descriptor instead.
-func (*ReadBuffer) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{5}
-}
-
-func (x *ReadBuffer) GetSize() uint32 {
-	if x != nil {
-		return x.Size
-	}
-	return 0
-}
-
-type ConnectionReuse struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Enable        bool                   `protobuf:"varint,1,opt,name=enable,proto3" json:"enable,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *ConnectionReuse) Reset() {
-	*x = ConnectionReuse{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[6]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *ConnectionReuse) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*ConnectionReuse) ProtoMessage() {}
-
-func (x *ConnectionReuse) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[6]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use ConnectionReuse.ProtoReflect.Descriptor instead.
-func (*ConnectionReuse) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{6}
-}
-
-func (x *ConnectionReuse) GetEnable() bool {
-	if x != nil {
-		return x.Enable
-	}
-	return false
-}
-
-// Pre-shared secret between client and server. It is used for traffic obfuscation.
-// Note that if seed is absent in the config, the traffic will still be obfuscated,
-// but by a predefined algorithm.
-type EncryptionSeed struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Seed          string                 `protobuf:"bytes,1,opt,name=seed,proto3" json:"seed,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
-}
-
-func (x *EncryptionSeed) Reset() {
-	*x = EncryptionSeed{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[7]
-	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-	ms.StoreMessageInfo(mi)
-}
-
-func (x *EncryptionSeed) String() string {
-	return protoimpl.X.MessageStringOf(x)
-}
-
-func (*EncryptionSeed) ProtoMessage() {}
-
-func (x *EncryptionSeed) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[7]
-	if x != nil {
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		if ms.LoadMessageInfo() == nil {
-			ms.StoreMessageInfo(mi)
-		}
-		return ms
-	}
-	return mi.MessageOf(x)
-}
-
-// Deprecated: Use EncryptionSeed.ProtoReflect.Descriptor instead.
-func (*EncryptionSeed) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{7}
-}
-
-func (x *EncryptionSeed) GetSeed() string {
-	if x != nil {
-		return x.Seed
-	}
-	return ""
-}
-
 type Config struct {
 	state            protoimpl.MessageState `protogen:"open.v1"`
-	Mtu              *MTU                   `protobuf:"bytes,1,opt,name=mtu,proto3" json:"mtu,omitempty"`
+	Mtu              uint32                 `protobuf:"varint,1,opt,name=mtu,proto3" json:"mtu,omitempty"`
-	Tti              *TTI                   `protobuf:"bytes,2,opt,name=tti,proto3" json:"tti,omitempty"`
+	Tti              uint32                 `protobuf:"varint,2,opt,name=tti,proto3" json:"tti,omitempty"`
-	UplinkCapacity   *UplinkCapacity        `protobuf:"bytes,3,opt,name=uplink_capacity,json=uplinkCapacity,proto3" json:"uplink_capacity,omitempty"`
+	UplinkCapacity   uint32                 `protobuf:"varint,3,opt,name=uplink_capacity,json=uplinkCapacity,proto3" json:"uplink_capacity,omitempty"`
-	DownlinkCapacity *DownlinkCapacity      `protobuf:"bytes,4,opt,name=downlink_capacity,json=downlinkCapacity,proto3" json:"downlink_capacity,omitempty"`
+	DownlinkCapacity uint32                 `protobuf:"varint,4,opt,name=downlink_capacity,json=downlinkCapacity,proto3" json:"downlink_capacity,omitempty"`
-	Congestion       bool                   `protobuf:"varint,5,opt,name=congestion,proto3" json:"congestion,omitempty"`
+	CwndMultiplier   uint32                 `protobuf:"varint,5,opt,name=cwnd_multiplier,json=cwndMultiplier,proto3" json:"cwnd_multiplier,omitempty"`
-	WriteBuffer      *WriteBuffer           `protobuf:"bytes,6,opt,name=write_buffer,json=writeBuffer,proto3" json:"write_buffer,omitempty"`
+	MaxSendingWindow uint32                 `protobuf:"varint,6,opt,name=max_sending_window,json=maxSendingWindow,proto3" json:"max_sending_window,omitempty"`
-	ReadBuffer       *ReadBuffer            `protobuf:"bytes,7,opt,name=read_buffer,json=readBuffer,proto3" json:"read_buffer,omitempty"`
-	HeaderConfig     *serial.TypedMessage   `protobuf:"bytes,8,opt,name=header_config,json=headerConfig,proto3" json:"header_config,omitempty"`
-	Seed             *EncryptionSeed        `protobuf:"bytes,10,opt,name=seed,proto3" json:"seed,omitempty"`
 	unknownFields    protoimpl.UnknownFields
 	sizeCache        protoimpl.SizeCache
 }
 
 func (x *Config) Reset() {
 	*x = Config{}
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[8]
+	mi := &file_transport_internet_kcp_config_proto_msgTypes[0]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -412,7 +47,7 @@ func (x *Config) String() string {
 func (*Config) ProtoMessage() {}
 
 func (x *Config) ProtoReflect() protoreflect.Message {
-	mi := &file_transport_internet_kcp_config_proto_msgTypes[8]
+	mi := &file_transport_internet_kcp_config_proto_msgTypes[0]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -425,109 +60,63 @@ func (x *Config) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use Config.ProtoReflect.Descriptor instead.
 func (*Config) Descriptor() ([]byte, []int) {
-	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{8}
+	return file_transport_internet_kcp_config_proto_rawDescGZIP(), []int{0}
 }
 
-func (x *Config) GetMtu() *MTU {
+func (x *Config) GetMtu() uint32 {
 	if x != nil {
 		return x.Mtu
 	}
-	return nil
+	return 0
 }
 
-func (x *Config) GetTti() *TTI {
+func (x *Config) GetTti() uint32 {
 	if x != nil {
 		return x.Tti
 	}
-	return nil
+	return 0
 }
 
-func (x *Config) GetUplinkCapacity() *UplinkCapacity {
+func (x *Config) GetUplinkCapacity() uint32 {
 	if x != nil {
 		return x.UplinkCapacity
 	}
-	return nil
+	return 0
 }
 
-func (x *Config) GetDownlinkCapacity() *DownlinkCapacity {
+func (x *Config) GetDownlinkCapacity() uint32 {
 	if x != nil {
 		return x.DownlinkCapacity
 	}
-	return nil
+	return 0
 }
 
-func (x *Config) GetCongestion() bool {
+func (x *Config) GetCwndMultiplier() uint32 {
 	if x != nil {
-		return x.Congestion
+		return x.CwndMultiplier
 	}
-	return false
+	return 0
 }
 
-func (x *Config) GetWriteBuffer() *WriteBuffer {
+func (x *Config) GetMaxSendingWindow() uint32 {
 	if x != nil {
-		return x.WriteBuffer
+		return x.MaxSendingWindow
 	}
-	return nil
+	return 0
-}
-
-func (x *Config) GetReadBuffer() *ReadBuffer {
-	if x != nil {
-		return x.ReadBuffer
-	}
-	return nil
-}
-
-func (x *Config) GetHeaderConfig() *serial.TypedMessage {
-	if x != nil {
-		return x.HeaderConfig
-	}
-	return nil
-}
-
-func (x *Config) GetSeed() *EncryptionSeed {
-	if x != nil {
-		return x.Seed
-	}
-	return nil
 }
 
 var File_transport_internet_kcp_config_proto protoreflect.FileDescriptor
 
 const file_transport_internet_kcp_config_proto_rawDesc = "" +
 	"\n" +
-	"#transport/internet/kcp/config.proto\x12\x1bxray.transport.internet.kcp\x1a!common/serial/typed_message.proto\"\x1b\n" +
+	"#transport/internet/kcp/config.proto\x12\x1bxray.transport.internet.kcp\"\xd9\x01\n" +
-	"\x03MTU\x12\x14\n" +
+	"\x06Config\x12\x10\n" +
-	"\x05value\x18\x01 \x01(\rR\x05value\"\x1b\n" +
+	"\x03mtu\x18\x01 \x01(\rR\x03mtu\x12\x10\n" +
-	"\x03TTI\x12\x14\n" +
+	"\x03tti\x18\x02 \x01(\rR\x03tti\x12'\n" +
-	"\x05value\x18\x01 \x01(\rR\x05value\"&\n" +
+	"\x0fuplink_capacity\x18\x03 \x01(\rR\x0euplinkCapacity\x12+\n" +
-	"\x0eUplinkCapacity\x12\x14\n" +
+	"\x11downlink_capacity\x18\x04 \x01(\rR\x10downlinkCapacity\x12'\n" +
-	"\x05value\x18\x01 \x01(\rR\x05value\"(\n" +
+	"\x0fcwnd_multiplier\x18\x05 \x01(\rR\x0ecwndMultiplier\x12,\n" +
-	"\x10DownlinkCapacity\x12\x14\n" +
+	"\x12max_sending_window\x18\x06 \x01(\rR\x10maxSendingWindowBs\n" +
-	"\x05value\x18\x01 \x01(\rR\x05value\"!\n" +
-	"\vWriteBuffer\x12\x12\n" +
-	"\x04size\x18\x01 \x01(\rR\x04size\" \n" +
-	"\n" +
-	"ReadBuffer\x12\x12\n" +
-	"\x04size\x18\x01 \x01(\rR\x04size\")\n" +
-	"\x0fConnectionReuse\x12\x16\n" +
-	"\x06enable\x18\x01 \x01(\bR\x06enable\"$\n" +
-	"\x0eEncryptionSeed\x12\x12\n" +
-	"\x04seed\x18\x01 \x01(\tR\x04seed\"\xe7\x04\n" +
-	"\x06Config\x122\n" +
-	"\x03mtu\x18\x01 \x01(\v2 .xray.transport.internet.kcp.MTUR\x03mtu\x122\n" +
-	"\x03tti\x18\x02 \x01(\v2 .xray.transport.internet.kcp.TTIR\x03tti\x12T\n" +
-	"\x0fuplink_capacity\x18\x03 \x01(\v2+.xray.transport.internet.kcp.UplinkCapacityR\x0euplinkCapacity\x12Z\n" +
-	"\x11downlink_capacity\x18\x04 \x01(\v2-.xray.transport.internet.kcp.DownlinkCapacityR\x10downlinkCapacity\x12\x1e\n" +
-	"\n" +
-	"congestion\x18\x05 \x01(\bR\n" +
-	"congestion\x12K\n" +
-	"\fwrite_buffer\x18\x06 \x01(\v2(.xray.transport.internet.kcp.WriteBufferR\vwriteBuffer\x12H\n" +
-	"\vread_buffer\x18\a \x01(\v2'.xray.transport.internet.kcp.ReadBufferR\n" +
-	"readBuffer\x12E\n" +
-	"\rheader_config\x18\b \x01(\v2 .xray.common.serial.TypedMessageR\fheaderConfig\x12?\n" +
-	"\x04seed\x18\n" +
-	" \x01(\v2+.xray.transport.internet.kcp.EncryptionSeedR\x04seedJ\x04\b\t\x10\n" +
-	"Bs\n" +
 	"\x1fcom.xray.transport.internet.kcpP\x01Z0github.com/xtls/xray-core/transport/internet/kcp\xaa\x02\x1bXray.Transport.Internet.Kcpb\x06proto3"
 
 var (
@@ -542,33 +131,16 @@ func file_transport_internet_kcp_config_proto_rawDescGZIP() []byte {
 	return file_transport_internet_kcp_config_proto_rawDescData
 }
 
-var file_transport_internet_kcp_config_proto_msgTypes = make([]protoimpl.MessageInfo, 9)
+var file_transport_internet_kcp_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
 var file_transport_internet_kcp_config_proto_goTypes = []any{
-	(*MTU)(nil),                 // 0: xray.transport.internet.kcp.MTU
+	(*Config)(nil), // 0: xray.transport.internet.kcp.Config
-	(*TTI)(nil),                 // 1: xray.transport.internet.kcp.TTI
-	(*UplinkCapacity)(nil),      // 2: xray.transport.internet.kcp.UplinkCapacity
-	(*DownlinkCapacity)(nil),    // 3: xray.transport.internet.kcp.DownlinkCapacity
-	(*WriteBuffer)(nil),         // 4: xray.transport.internet.kcp.WriteBuffer
-	(*ReadBuffer)(nil),          // 5: xray.transport.internet.kcp.ReadBuffer
-	(*ConnectionReuse)(nil),     // 6: xray.transport.internet.kcp.ConnectionReuse
-	(*EncryptionSeed)(nil),      // 7: xray.transport.internet.kcp.EncryptionSeed
-	(*Config)(nil),              // 8: xray.transport.internet.kcp.Config
-	(*serial.TypedMessage)(nil), // 9: xray.common.serial.TypedMessage
 }
 var file_transport_internet_kcp_config_proto_depIdxs = []int32{
-	0, // 0: xray.transport.internet.kcp.Config.mtu:type_name -> xray.transport.internet.kcp.MTU
+	0, // [0:0] is the sub-list for method output_type
-	1, // 1: xray.transport.internet.kcp.Config.tti:type_name -> xray.transport.internet.kcp.TTI
+	0, // [0:0] is the sub-list for method input_type
-	2, // 2: xray.transport.internet.kcp.Config.uplink_capacity:type_name -> xray.transport.internet.kcp.UplinkCapacity
+	0, // [0:0] is the sub-list for extension type_name
-	3, // 3: xray.transport.internet.kcp.Config.downlink_capacity:type_name -> xray.transport.internet.kcp.DownlinkCapacity
+	0, // [0:0] is the sub-list for extension extendee
-	4, // 4: xray.transport.internet.kcp.Config.write_buffer:type_name -> xray.transport.internet.kcp.WriteBuffer
+	0, // [0:0] is the sub-list for field type_name
-	5, // 5: xray.transport.internet.kcp.Config.read_buffer:type_name -> xray.transport.internet.kcp.ReadBuffer
-	9, // 6: xray.transport.internet.kcp.Config.header_config:type_name -> xray.common.serial.TypedMessage
-	7, // 7: xray.transport.internet.kcp.Config.seed:type_name -> xray.transport.internet.kcp.EncryptionSeed
-	8, // [8:8] is the sub-list for method output_type
-	8, // [8:8] is the sub-list for method input_type
-	8, // [8:8] is the sub-list for extension type_name
-	8, // [8:8] is the sub-list for extension extendee
-	0, // [0:8] is the sub-list for field type_name
 }
 
 func init() { file_transport_internet_kcp_config_proto_init() }
@@ -582,7 +154,7 @@ func file_transport_internet_kcp_config_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_kcp_config_proto_rawDesc), len(file_transport_internet_kcp_config_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   9,
+			NumMessages:   1,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

transport/internet/kcp/config.proto

@@ -6,58 +6,11 @@ option go_package = "github.com/xtls/xray-core/transport/internet/kcp";
 option java_package = "com.xray.transport.internet.kcp";
 option java_multiple_files = true;
 
-import "common/serial/typed_message.proto";
-
-// Maximum Transmission Unit, in bytes.
-message MTU {
-  uint32 value = 1;
-}
-
-// Transmission Time Interview, in milli-sec.
-message TTI {
-  uint32 value = 1;
-}
-
-// Uplink capacity, in MB.
-message UplinkCapacity {
-  uint32 value = 1;
-}
-
-// Downlink capacity, in MB.
-message DownlinkCapacity {
-  uint32 value = 1;
-}
-
-message WriteBuffer {
-  // Buffer size in bytes.
-  uint32 size = 1;
-}
-
-message ReadBuffer {
-  // Buffer size in bytes.
-  uint32 size = 1;
-}
-
-message ConnectionReuse {
-  bool enable = 1;
-}
-
-// Pre-shared secret between client and server. It is used for traffic obfuscation.
-// Note that if seed is absent in the config, the traffic will still be obfuscated,
-// but by a predefined algorithm.
-message EncryptionSeed {
-  string seed = 1;
-}
-
 message Config {
-  MTU mtu = 1;
+  uint32 mtu = 1;
-  TTI tti = 2;
+  uint32 tti = 2;
-  UplinkCapacity uplink_capacity = 3;
+  uint32 uplink_capacity = 3;
-  DownlinkCapacity downlink_capacity = 4;
+  uint32 downlink_capacity = 4;
-  bool congestion = 5;
+  uint32 cwnd_multiplier = 5;
-  WriteBuffer write_buffer = 6;
+  uint32 max_sending_window = 6;
-  ReadBuffer read_buffer = 7;
+}
-  xray.common.serial.TypedMessage header_config = 8;
-  reserved 9;
-  EncryptionSeed seed = 10;
-}

transport/internet/kcp/connection.go

@@ -215,10 +215,10 @@ func NewConnection(meta ConnMetadata, writer io.Writer, closer io.Closer, config
 		dataOutput: signal.NewNotifier(),
 		Config:     config,
 		output:     NewRetryableWriter(NewSegmentWriter(writer)),
-		mss:        config.GetMTUValue() - DataSegmentOverhead,
+		mss:        config.Mtu - DataSegmentOverhead,
 		roundTrip: &RoundTripInfo{
 			rto:    100,
-			minRtt: config.GetTTIValue(),
+			minRtt: config.Tti,
 		},
 	}
 
@@ -232,7 +232,7 @@ func NewConnection(meta ConnMetadata, writer io.Writer, closer io.Closer, config
 		return conn.State() == StateTerminated
 	}
 	conn.dataUpdater = NewUpdater(
-		config.GetTTIValue(),
+		config.Tti,
 		func() bool {
 			return !isTerminating() && (conn.sendingWorker.UpdateNecessary() || conn.receivingWorker.UpdateNecessary())
 		},

transport/internet/kcp/connection_test.go

@@ -16,7 +16,14 @@ func (NoOpCloser) Close() error {
 }
 
 func TestConnectionReadTimeout(t *testing.T) {
-	conn := NewConnection(ConnMetadata{Conversation: 1}, buf.DiscardBytes, NoOpCloser(0), &Config{})
+	conn := NewConnection(ConnMetadata{Conversation: 1}, buf.DiscardBytes, NoOpCloser(0), &Config{
+		Mtu:              1350,
+		Tti:              50,
+		UplinkCapacity:   5,
+		DownlinkCapacity: 20,
+		CwndMultiplier:   20,
+		MaxSendingWindow: 2 * 1024 * 1024,
+	})
 	conn.SetReadDeadline(time.Now().Add(time.Second))
 
 	b := make([]byte, 1024)

transport/internet/kcp/dialer.go

@@ -118,5 +118,5 @@ func DialKCP(ctx context.Context, dest net.Destination, streamSettings *internet
 }
 
 func init() {
-	common.Must(internet.RegisterTransportDialer(protocolName, DialKCP))
+	common.Must(internet.RegisterTransportDialer(ProtocolName, DialKCP))
 }

transport/internet/kcp/kcp.go

@@ -6,4 +6,4 @@
 //	xtaci@github for translating to Golang
 package kcp
 
-const protocolName = "mkcp"
+const ProtocolName = "mkcp"

transport/internet/kcp/kcp_test.go

@@ -19,8 +19,15 @@ import (
 
 func TestDialAndListen(t *testing.T) {
 	listerner, err := NewListener(context.Background(), net.LocalHostIP, net.Port(0), &internet.MemoryStreamConfig{
-		ProtocolName:     "mkcp",
+		ProtocolName: "mkcp",
-		ProtocolSettings: &Config{},
+		ProtocolSettings: &Config{
+			Mtu:              1350,
+			Tti:              50,
+			UplinkCapacity:   5,
+			DownlinkCapacity: 20,
+			CwndMultiplier:   20,
+			MaxSendingWindow: 2 * 1024 * 1024,
+		},
 	}, func(conn stat.Connection) {
 		go func(c stat.Connection) {
 			payload := make([]byte, 4096)
@@ -46,8 +53,15 @@ func TestDialAndListen(t *testing.T) {
 	for i := 0; i < 10; i++ {
 		errg.Go(func() error {
 			clientConn, err := DialKCP(context.Background(), net.UDPDestination(net.LocalHostIP, port), &internet.MemoryStreamConfig{
-				ProtocolName:     "mkcp",
+				ProtocolName: "mkcp",
-				ProtocolSettings: &Config{},
+				ProtocolSettings: &Config{
+					Mtu:              1350,
+					Tti:              50,
+					UplinkCapacity:   5,
+					DownlinkCapacity: 20,
+					CwndMultiplier:   20,
+					MaxSendingWindow: 2 * 1024 * 1024,
+				},
 			})
 			if err != nil {
 				return err

transport/internet/kcp/listener.go

@@ -174,5 +174,5 @@ func ListenKCP(ctx context.Context, address net.Address, port net.Port, streamSe
 }
 
 func init() {
-	common.Must(internet.RegisterTransportListener(protocolName, ListenKCP))
+	common.Must(internet.RegisterTransportListener(ProtocolName, ListenKCP))
 }

transport/internet/kcp/sending.go

@@ -288,20 +288,22 @@ func (w *SendingWorker) Write(seg Segment) error {
 }
 
 func (w *SendingWorker) OnPacketLoss(lossRate uint32) {
-	if !w.conn.Config.Congestion || w.conn.roundTrip.Timeout() == 0 {
+	if w.conn.roundTrip.Timeout() == 0 {
 		return
 	}
 
 	if lossRate >= 15 {
 		w.controlWindow = 3 * w.controlWindow / 4
-	} else if lossRate <= 5 {
+	}
+	if lossRate <= 5 {
 		w.controlWindow += w.controlWindow / 4
 	}
 	if w.controlWindow < 16 {
 		w.controlWindow = 16
 	}
-	if w.controlWindow > 2*w.conn.Config.GetSendingInFlightSize() {
+	cwnd := w.conn.Config.GetSendingInFlightSize()
-		w.controlWindow = 2 * w.conn.Config.GetSendingInFlightSize()
+	if w.controlWindow > cwnd {
+		w.controlWindow = cwnd
 	}
 }
 
@@ -317,11 +319,11 @@ func (w *SendingWorker) Flush(current uint32) {
 	if cwnd > w.remoteNextNumber-w.firstUnacknowledged {
 		cwnd = w.remoteNextNumber - w.firstUnacknowledged
 	}
-	if w.conn.Config.Congestion && cwnd > w.controlWindow {
+	if cwnd > w.controlWindow {
 		cwnd = w.controlWindow
 	}
 
-	cwnd *= 20 // magic
+	cwnd *= w.conn.Config.CwndMultiplier
 
 	if !w.window.IsEmpty() {
 		w.window.Flush(current, w.conn.roundTrip.Timeout(), cwnd)