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

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

proxy/masque/client.go

@@ -0,0 +1,328 @@
+package masque
+
+import (
+	"context"
+	go_errors "errors"
+	"io"
+	"net/netip"
+	"slices"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"golang.zx2c4.com/wireguard/tun"
+
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/buf"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/common/session"
+	"github.com/xtls/xray-core/common/signal"
+	"github.com/xtls/xray-core/common/task"
+	"github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/features/policy"
+	"github.com/xtls/xray-core/proxy/wireguard"
+	"github.com/xtls/xray-core/transport"
+	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/masque"
+	"github.com/xtls/xray-core/transport/internet/stat"
+	"github.com/xtls/xray-core/transport/internet/tls"
+)
+
+const (
+	establishTimeout = 10 * time.Second
+	retryInterval    = time.Second
+)
+
+type Client struct {
+	server        *protocol.ServerSpec
+	policyManager policy.Manager
+	remoteDNS     []netip.Addr
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	tunnel atomic.Pointer[tunnel]
+
+	mu        sync.Mutex
+	lastErr   error
+	lastErrAt time.Time
+}
+
+func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
+	v := core.MustFromContext(ctx)
+	p := v.GetFeature(policy.ManagerType()).(policy.Manager)
+
+	streamSettings := session.StreamSettingsFromContext(ctx).(*internet.MemoryStreamConfig)
+	if _, ok := streamSettings.ProtocolSettings.(*masque.Config); !ok {
+		return nil, errors.New("not masque transport")
+	}
+	if tls.ConfigFromStreamSettings(streamSettings) == nil {
+		return nil, errors.New(`MASQUE requires "security": "tls"`)
+	}
+	if config.Server == nil {
+		return nil, errors.New(`no target server found`)
+	}
+	server, err := protocol.NewServerSpecFromPB(config.Server)
+	if err != nil {
+		return nil, errors.New("failed to get server spec").Base(err)
+	}
+
+	dns := config.RemoteDns
+	if len(dns) == 0 {
+		dns = []string{"1.1.1.1", "1.0.0.1", "2606:4700:4700::1111", "2606:4700:4700::1001"}
+	}
+	remoteDNS := make([]netip.Addr, 0, len(dns))
+	for _, s := range dns {
+		addr, err := netip.ParseAddr(s)
+		if err != nil {
+			return nil, errors.New("invalid remote DNS server ", s).Base(err)
+		}
+		remoteDNS = append(remoteDNS, addr)
+	}
+
+	c := &Client{
+		server:        server,
+		policyManager: p,
+		remoteDNS:     remoteDNS,
+	}
+	c.ctx, c.cancel = context.WithCancel(context.Background())
+	return c, nil
+}
+
+func (c *Client) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error {
+	outbounds := session.OutboundsFromContext(ctx)
+	ob := outbounds[len(outbounds)-1]
+	if !ob.Target.IsValid() {
+		return errors.New("target not specified")
+	}
+	ob.Name = "masque"
+	ob.CanSpliceCopy = 3
+
+	t, err := c.getTunnel(ctx, dialer)
+	if err != nil {
+		return errors.New("failed to establish CONNECT-IP tunnel").Base(err)
+	}
+
+	var newCtx context.Context
+	var newCancel context.CancelFunc
+	if session.TimeoutOnlyFromContext(ctx) {
+		newCtx, newCancel = context.WithCancel(context.Background())
+	}
+
+	sessionPolicy := c.policyManager.ForLevel(0)
+	ctx, cancel := context.WithCancel(ctx)
+	timer := signal.CancelAfterInactivity(ctx, func() {
+		cancel()
+		if newCancel != nil {
+			newCancel()
+		}
+	}, sessionPolicy.Timeouts.ConnectionIdle)
+
+	if newCtx != nil {
+		ctx = newCtx
+	}
+
+	var reader buf.Reader
+	var writer buf.Writer
+
+	switch ob.Target.Network {
+	case net.Network_TCP:
+		var conn net.Conn
+		var err error
+		if sessionPolicy.Timeouts.Handshake != 0 {
+			timeoutCtx, timeoutCancel := context.WithTimeout(ctx, sessionPolicy.Timeouts.Handshake)
+			conn, err = t.tnet.DialContext(timeoutCtx, "tcp", ob.Target.NetAddr())
+			timeoutCancel()
+		} else {
+			conn, err = t.tnet.Dial("tcp", ob.Target.NetAddr())
+		}
+		if err != nil {
+			return errors.New("failed to create TCP connection").Base(err)
+		}
+		defer conn.Close()
+		reader = buf.NewReader(conn)
+		writer = buf.NewWriter(conn)
+	case net.Network_UDP:
+		conn, err := t.tnet.Dial("udp", ob.Target.NetAddr())
+		if err != nil {
+			return errors.New("failed to create UDP connection").Base(err)
+		}
+		defer conn.Close()
+		uc := &wireguard.UDPConnClient{
+			PacketConn: conn.(*internet.PacketConnWrapper).PacketConn,
+			Dest:       conn.RemoteAddr().(*net.UDPAddr),
+		}
+		reader = uc
+		writer = uc
+	default:
+		panic(ob.Target.Network)
+	}
+
+	requestFunc := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
+		return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
+	}
+
+	responseFunc := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
+		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
+	}
+
+	responseDonePost := task.OnSuccess(responseFunc, task.Close(link.Writer))
+	if err := task.Run(ctx, requestFunc, responseDonePost); err != nil {
+		common.Interrupt(link.Reader)
+		common.Interrupt(link.Writer)
+		return errors.New("connection ends").Base(err)
+	}
+
+	return nil
+}
+
+func (c *Client) getTunnel(ctx context.Context, dialer internet.Dialer) (*tunnel, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.ctx.Err() != nil {
+		return nil, errors.New("closed")
+	}
+	if t := c.tunnel.Load(); t != nil {
+		select {
+		case <-t.done:
+		default:
+			return t, nil
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if c.lastErr != nil && time.Since(c.lastErrAt) < retryInterval {
+		return nil, c.lastErr
+	}
+
+	t, err := c.establish(ctx, dialer)
+	if err != nil {
+		c.lastErr, c.lastErrAt = err, time.Now()
+		return nil, err
+	}
+	c.lastErr = nil
+	c.tunnel.Store(t)
+	if c.ctx.Err() != nil {
+		if c.tunnel.CompareAndSwap(t, nil) {
+			t.close()
+		}
+		return nil, errors.New("closed")
+	}
+	return t, nil
+}
+
+func (c *Client) establish(ctx context.Context, dialer internet.Dialer) (*tunnel, error) {
+	ctx, cancel := context.WithTimeout(context.WithoutCancel(ctx), establishTimeout)
+	defer cancel()
+	defer context.AfterFunc(c.ctx, cancel)()
+	conn, err := dialer.Dial(ctx, c.server.Destination)
+	if err != nil {
+		return nil, err
+	}
+	mconn, ok := stat.TryUnwrapStatsConn(conn).(*masque.Conn)
+	if !ok {
+		conn.Close()
+		return nil, errors.New("not a CONNECT-IP connection")
+	}
+	t, err := newTunnel(conn, mconn.LocalAddrs(), c.remoteDNS)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	errors.LogInfo(ctx, "MASQUE: tunnel established from ", mconn.LocalAddrs())
+	return t, nil
+}
+
+func (c *Client) Close() error {
+	c.cancel()
+	if t := c.tunnel.Swap(nil); t != nil {
+		t.close()
+	}
+	return nil
+}
+
+type tunnel struct {
+	conn      stat.Connection
+	dev       tun.Device
+	tnet      *wireguard.Net
+	done      chan struct{}
+	closeOnce sync.Once
+}
+
+func newTunnel(conn stat.Connection, local []netip.Addr, remoteDNS []netip.Addr) (*tunnel, error) {
+	var dns []netip.Addr
+	for _, addr := range remoteDNS {
+		if slices.ContainsFunc(local, func(l netip.Addr) bool { return l.Is4() == addr.Is4() }) {
+			dns = append(dns, addr)
+		}
+	}
+	if len(dns) == 0 {
+		errors.LogWarning(context.Background(), "MASQUE: no remote DNS server is reachable from the assigned addresses ", local, ", domain names will fail to resolve")
+		dns = remoteDNS
+	}
+
+	dev, tnet, _, err := wireguard.CreateNetTUN(local, dns, masque.MinPacketSize, true)
+	if err != nil {
+		return nil, err
+	}
+	t := &tunnel{
+		conn: conn,
+		dev:  dev,
+		tnet: tnet,
+		done: make(chan struct{}),
+	}
+	go t.readFromTunnel()
+	go t.writeToTunnel()
+	return t, nil
+}
+
+func (t *tunnel) readFromTunnel() {
+	defer t.close()
+	b := make([]byte, buf.Size)
+	for {
+		n, err := t.conn.Read(b)
+		if err != nil {
+			if go_errors.Is(err, io.ErrShortBuffer) {
+				continue
+			}
+			errors.LogInfoInner(context.Background(), err, "MASQUE: tunnel closed")
+			return
+		}
+		t.dev.Write([][]byte{b[:n]}, 0)
+	}
+}
+
+func (t *tunnel) writeToTunnel() {
+	bufs := [][]byte{make([]byte, masque.MinPacketSize)}
+	sizes := []int{0}
+	for {
+		if _, err := t.dev.Read(bufs, sizes, 0); err != nil {
+			return
+		}
+		if _, err := t.conn.Write(bufs[0][:sizes[0]]); err != nil {
+			var ptb *masque.PacketTooBigError
+			if go_errors.As(err, &ptb) {
+				go t.dev.Write([][]byte{ptb.ICMP}, 0)
+			}
+		}
+	}
+}
+
+func (t *tunnel) close() {
+	t.closeOnce.Do(func() {
+		close(t.done)
+		t.conn.Close()
+		t.dev.Close()
+	})
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
+		return NewClient(ctx, config.(*ClientConfig))
+	}))
+}

proxy/masque/config.pb.go

@@ -0,0 +1,136 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        v6.33.5
+// source: proxy/masque/config.proto
+
+package masque
+
+import (
+	protocol "github.com/xtls/xray-core/common/protocol"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+	unsafe "unsafe"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type ClientConfig struct {
+	state         protoimpl.MessageState   `protogen:"open.v1"`
+	Server        *protocol.ServerEndpoint `protobuf:"bytes,1,opt,name=server,proto3" json:"server,omitempty"`
+	RemoteDns     []string                 `protobuf:"bytes,2,rep,name=remote_dns,json=remoteDns,proto3" json:"remote_dns,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ClientConfig) Reset() {
+	*x = ClientConfig{}
+	mi := &file_proxy_masque_config_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ClientConfig) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ClientConfig) ProtoMessage() {}
+
+func (x *ClientConfig) ProtoReflect() protoreflect.Message {
+	mi := &file_proxy_masque_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 ClientConfig.ProtoReflect.Descriptor instead.
+func (*ClientConfig) Descriptor() ([]byte, []int) {
+	return file_proxy_masque_config_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *ClientConfig) GetServer() *protocol.ServerEndpoint {
+	if x != nil {
+		return x.Server
+	}
+	return nil
+}
+
+func (x *ClientConfig) GetRemoteDns() []string {
+	if x != nil {
+		return x.RemoteDns
+	}
+	return nil
+}
+
+var File_proxy_masque_config_proto protoreflect.FileDescriptor
+
+const file_proxy_masque_config_proto_rawDesc = "" +
+	"\n" +
+	"\x19proxy/masque/config.proto\x12\x11xray.proxy.masque\x1a!common/protocol/server_spec.proto\"k\n" +
+	"\fClientConfig\x12<\n" +
+	"\x06server\x18\x01 \x01(\v2$.xray.common.protocol.ServerEndpointR\x06server\x12\x1d\n" +
+	"\n" +
+	"remote_dns\x18\x02 \x03(\tR\tremoteDnsBU\n" +
+	"\x15com.xray.proxy.masqueP\x01Z&github.com/xtls/xray-core/proxy/masque\xaa\x02\x11Xray.Proxy.Masqueb\x06proto3"
+
+var (
+	file_proxy_masque_config_proto_rawDescOnce sync.Once
+	file_proxy_masque_config_proto_rawDescData []byte
+)
+
+func file_proxy_masque_config_proto_rawDescGZIP() []byte {
+	file_proxy_masque_config_proto_rawDescOnce.Do(func() {
+		file_proxy_masque_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_proxy_masque_config_proto_rawDesc), len(file_proxy_masque_config_proto_rawDesc)))
+	})
+	return file_proxy_masque_config_proto_rawDescData
+}
+
+var file_proxy_masque_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_proxy_masque_config_proto_goTypes = []any{
+	(*ClientConfig)(nil),            // 0: xray.proxy.masque.ClientConfig
+	(*protocol.ServerEndpoint)(nil), // 1: xray.common.protocol.ServerEndpoint
+}
+var file_proxy_masque_config_proto_depIdxs = []int32{
+	1, // 0: xray.proxy.masque.ClientConfig.server:type_name -> xray.common.protocol.ServerEndpoint
+	1, // [1:1] is the sub-list for method output_type
+	1, // [1:1] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_proxy_masque_config_proto_init() }
+func file_proxy_masque_config_proto_init() {
+	if File_proxy_masque_config_proto != nil {
+		return
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_proxy_masque_config_proto_rawDesc), len(file_proxy_masque_config_proto_rawDesc)),
+			NumEnums:      0,
+			NumMessages:   1,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_proxy_masque_config_proto_goTypes,
+		DependencyIndexes: file_proxy_masque_config_proto_depIdxs,
+		MessageInfos:      file_proxy_masque_config_proto_msgTypes,
+	}.Build()
+	File_proxy_masque_config_proto = out.File
+	file_proxy_masque_config_proto_goTypes = nil
+	file_proxy_masque_config_proto_depIdxs = nil
+}

proxy/masque/config.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package xray.proxy.masque;
+option csharp_namespace = "Xray.Proxy.Masque";
+option go_package = "github.com/xtls/xray-core/proxy/masque";
+option java_package = "com.xray.proxy.masque";
+option java_multiple_files = true;
+
+import "common/protocol/server_spec.proto";
+
+message ClientConfig {
+  xray.common.protocol.ServerEndpoint server = 1;
+  repeated string remote_dns = 2;
+}

proxy/wireguard/client.go

@@ -199,9 +199,9 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 			return errors.New("failed to create UDP connection").Base(err)
 		}
 		defer conn.Close()
-		c := &udpConnClient{
+		c := &UDPConnClient{
 			PacketConn: conn.(*internet.PacketConnWrapper).PacketConn,
-			dest:       conn.RemoteAddr().(*net.UDPAddr),
+			Dest:       conn.RemoteAddr().(*net.UDPAddr),
 		}
 		reader = c
 		writer = c
@@ -378,12 +378,12 @@ func (h *Handler) resolveLocal(host string) (net.IP, error) {
 	return got[dice.Roll(len(got))], nil
 }
 
-type udpConnClient struct {
+type UDPConnClient struct {
 	net.PacketConn
-	dest *net.UDPAddr
+	Dest *net.UDPAddr
 }
 
-func (c *udpConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
+func (c *UDPConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	b := buf.New()
 	b.Resize(0, buf.Size)
 	n, addr, err := c.PacketConn.ReadFrom(b.Bytes())
@@ -402,9 +402,9 @@ func (c *udpConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	return buf.MultiBuffer{b}, nil
 }
 
-func (c *udpConnClient) WriteMultiBuffer(mb buf.MultiBuffer) error {
+func (c *UDPConnClient) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	for i, b := range mb {
-		dst := c.dest
+		dst := c.Dest
 		if b.UDP != nil {
 			if b.UDP.Address.Family().IsDomain() {
 				if b.UDP.Port != net.Port(dst.Port) {
@@ -462,20 +462,27 @@ func (c *cache) run() {
 		return
 	}
 	c.running = true
-	c.m = make(map[string]entry)
+	if c.m == nil {
+		c.m = make(map[string]entry)
+	}
 	go c.gc()
 }
 
 func (c *cache) gc() {
 	ticker := time.NewTicker(time.Minute)
-	for {
-		now := <-ticker.C
+	defer ticker.Stop()
+	for now := range ticker.C {
 		c.mu.Lock()
 		for key, entry := range c.m {
 			if now.After(entry.deadline) {
 				delete(c.m, key)
 			}
 		}
+		if len(c.m) == 0 {
+			c.running = false
+			c.mu.Unlock()
+			return
+		}
 		c.mu.Unlock()
 	}
 }