Proxy: Add MASQUE outbound & transport (IETF CONNECT-IP, RFC 9484) (#6807)

Closes https://github.com/XTLS/Xray-core/issues/5495#issuecomment-3710683679

infra/conf/masque.go

@@ -0,0 +1,37 @@
+package conf
+
+import (
+	"net/netip"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/proxy/masque"
+	"google.golang.org/protobuf/proto"
+)
+
+type MasqueClientConfig struct {
+	Address   *Address `json:"address"`
+	Port      uint16   `json:"port"`
+	RemoteDNS []string `json:"remoteDNS"`
+}
+
+func (c *MasqueClientConfig) Build() (proto.Message, error) {
+	if c.Address == nil {
+		return nil, errors.New(`MASQUE: "address" is not set`)
+	}
+	if c.Port == 0 {
+		return nil, errors.New(`MASQUE: "port" is not set`)
+	}
+	for _, s := range c.RemoteDNS {
+		if _, err := netip.ParseAddr(s); err != nil {
+			return nil, errors.New(`MASQUE: invalid "remoteDNS" `, s).Base(err)
+		}
+	}
+	return &masque.ClientConfig{
+		Server: &protocol.ServerEndpoint{
+			Address: c.Address.Build(),
+			Port:    uint32(c.Port),
+		},
+		RemoteDns: c.RemoteDNS,
+	}, nil
+}

infra/conf/masque_test.go

@@ -0,0 +1,85 @@
+package conf_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	. "github.com/xtls/xray-core/infra/conf"
+	"github.com/xtls/xray-core/transport/internet/masque"
+)
+
+func TestMasqueConfig(t *testing.T) {
+	creator := func() Buildable {
+		return new(MasqueConfig)
+	}
+
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  `{}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{Path: "/.well-known/masque/ip/*/*/"},
+		},
+		{
+			Input: `{
+				"host": "example.com:8443",
+				"path": "/.well-known/masque/ip/{target}/{ipproto}/",
+				"headers": {"Authorization": "Basic dTpw"}
+			}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Host:    "example.com:8443",
+				Path:    "/.well-known/masque/ip/*/*/",
+				Headers: map[string]string{"Authorization": "Basic dTpw"},
+			},
+		},
+		{
+			Input:  `{"path": "/masque/ip{?target,ipproto}"}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{Path: "/masque/ip?target=*&ipproto=*"},
+		},
+	})
+
+	for _, input := range []string{
+		`{"path": "/masque/{target}/{ipproto}/{dns}"}`,
+		`{"path": "masque"}`,
+		`{"host": "example.com/path"}`,
+		`{"headers": {"host": "example.com"}}`,
+		`{"headers": {"Capsule-Protocol": "?0"}}`,
+		`{"headers": {"X Token": "a"}}`,
+		`{"headers": {"X-Token": "a\r\nb"}}`,
+	} {
+		if _, err := loadJSON(creator)(input); err == nil {
+			t.Errorf("expected an error for %s", input)
+		}
+	}
+}
+
+func TestMasqueOutboundConfig(t *testing.T) {
+	build := func(s string) error {
+		c := new(OutboundDetourConfig)
+		if err := json.Unmarshal([]byte(s), c); err != nil {
+			return err
+		}
+		_, err := c.Build()
+		return err
+	}
+
+	if err := build(`{
+		"protocol": "masque",
+		"settings": {"address": "example.com", "port": 443},
+		"streamSettings": {"network": "masque", "security": "tls"},
+		"mux": {"enabled": false, "concurrency": -1}
+	}`); err != nil {
+		t.Error(err)
+	}
+	for _, input := range []string{
+		`{"protocol": "masque", "settings": {"address": "example.com"}, "streamSettings": {"network": "masque", "security": "tls"}}`,
+		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true}}`,
+		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true, "concurrency": -1}}`,
+		`{"protocol": "freedom", "streamSettings": {"network": "masque", "security": "tls"}}`,
+	} {
+		if err := build(input); err == nil {
+			t.Errorf("expected an error for %s", input)
+		}
+	}
+}

infra/conf/transport_internet.go

@@ -36,6 +36,8 @@ func (p TransportProtocol) Build() (string, error) {
 		return "", errors.PrintRemovedFeatureError("QUIC transport (without web service, etc.)", "XHTTP stream-one H3")
 	case "hysteria":
 		return "hysteria", nil
+	case "masque":
+		return "masque", nil
 	case "xdrive":
 		return "xdrive", nil
 	default:
@@ -61,6 +63,7 @@ type StreamConfig struct {
 	WSSettings          *WebSocketConfig   `json:"wsSettings"`
 	HTTPUPGRADESettings *HttpUpgradeConfig `json:"httpupgradeSettings"`
 	HysteriaSettings    *HysteriaConfig    `json:"hysteriaSettings"`
+	MASQUESettings      *MasqueConfig      `json:"masqueSettings"`
 	XDRIVESettings      *XDriveConfig      `json:"xdriveSettings"`
 	SocketSettings      *SocketConfig      `json:"sockopt"`
 }
@@ -195,6 +198,16 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 			Settings:     serial.ToTypedMessage(hs),
 		})
 	}
+	if c.MASQUESettings != nil {
+		ms, err := c.MASQUESettings.Build()
+		if err != nil {
+			return nil, errors.New("Failed to build MASQUE config.").Base(err)
+		}
+		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
+			ProtocolName: "masque",
+			Settings:     serial.ToTypedMessage(ms),
+		})
+	}
 	if c.XDRIVESettings != nil {
 		xs, err := c.XDRIVESettings.Build()
 		if err != nil {

infra/conf/transport_method.go

@@ -20,10 +20,12 @@ import (
 	"github.com/xtls/xray-core/transport/internet/httpupgrade"
 	"github.com/xtls/xray-core/transport/internet/hysteria"
 	"github.com/xtls/xray-core/transport/internet/kcp"
+	"github.com/xtls/xray-core/transport/internet/masque"
 	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/tcp"
 	"github.com/xtls/xray-core/transport/internet/websocket"
 	"github.com/xtls/xray-core/transport/internet/xdrive"
+	"golang.org/x/net/http/httpguts"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -786,6 +788,46 @@ func (c *HysteriaConfig) Build() (proto.Message, error) {
 	return config, nil
 }
 
+type MasqueConfig struct {
+	Host    string            `json:"host"`
+	Path    string            `json:"path"`
+	Headers map[string]string `json:"headers"`
+}
+
+func (c *MasqueConfig) Build() (proto.Message, error) {
+	path := c.Path
+	if path == "" {
+		path = masque.DefaultPath
+	}
+	path = strings.NewReplacer(
+		"{target}", "*", "{ipproto}", "*",
+		"{?target,ipproto}", "?target=*&ipproto=*", "{?ipproto,target}", "?ipproto=*&target=*",
+		"{&target,ipproto}", "&target=*&ipproto=*", "{&ipproto,target}", "&ipproto=*&target=*",
+	).Replace(path)
+	if !strings.HasPrefix(path, "/") || strings.ContainsAny(path, "{}") {
+		return nil, errors.New(`invalid "path": `, path, `, only the variables {target} and {ipproto} are supported`)
+	}
+	if c.Host != "" {
+		if u, err := url.Parse("https://" + c.Host); err != nil || u.Host != c.Host {
+			return nil, errors.New(`invalid "host": `, c.Host)
+		}
+	}
+	for k, v := range c.Headers {
+		if !httpguts.ValidHeaderFieldName(k) || !httpguts.ValidHeaderFieldValue(v) {
+			return nil, errors.New(`invalid header in "headers": `, strconv.Quote(k))
+		}
+		switch strings.ToLower(k) {
+		case "host", "capsule-protocol":
+			return nil, errors.New(`"headers" can't contain "`, k, `"`)
+		}
+	}
+	return &masque.Config{
+		Host:    c.Host,
+		Path:    path,
+		Headers: c.Headers,
+	}, nil
+}
+
 func readFileOrString(f string, s []string) ([]byte, error) {
 	if len(f) > 0 {
 		return filesystem.ReadCert(f)

infra/conf/xray.go

@@ -16,6 +16,7 @@ import (
 	"github.com/xtls/xray-core/common/serial"
 	core "github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/proxy/freedom"
+	"github.com/xtls/xray-core/proxy/masque"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
@@ -48,6 +49,7 @@ var (
 		"vmess":       func() interface{} { return new(VMessOutboundConfig) },
 		"trojan":      func() interface{} { return new(TrojanClientConfig) },
 		"hysteria":    func() interface{} { return new(HysteriaClientConfig) },
+		"masque":      func() interface{} { return new(MasqueClientConfig) },
 		"dns":         func() interface{} { return new(DNSOutboundConfig) },
 		"wireguard":   func() interface{} { return &WireGuardConfig{IsClient: true} },
 	}, "protocol", "settings")
@@ -338,6 +340,14 @@ func (c *OutboundDetourConfig) Build() (*core.OutboundHandlerConfig, error) {
 		return nil, err
 	}
 
+	if _, ok := ts.(*masque.ClientConfig); ok {
+		if ms := senderSettings.MultiplexSettings; ms != nil && ms.Enabled {
+			return nil, errors.New(`masque outbound does not support "mux"`)
+		}
+	} else if senderSettings.StreamSettings != nil && senderSettings.StreamSettings.ProtocolName == "masque" {
+		return nil, errors.New("the masque transport can only be used by the masque outbound")
+	}
+
 	if fc, ok := ts.(*freedom.Config); ok {
 		if senderSettings.StreamSettings != nil &&
 			senderSettings.StreamSettings.SocketSettings != nil &&