Add relay type outbound

adapter/experimental.go

@@ -114,6 +114,11 @@ type URLTestGroup interface {
 	URLTest(ctx context.Context) (map[string]uint16, error)
 }
 
+type RelayGroup interface {
+	OutboundGroup
+	IsRelay() bool
+}
+
 func OutboundTag(detour Outbound) string {
 	if group, isGroup := detour.(OutboundGroup); isGroup {
 		return group.Now()

adapter/outbound.go

@@ -24,3 +24,7 @@ type Outbound interface {
 type OutboundUseIP interface {
 	UseIP() bool
 }
+
+type OutboundRelay interface {
+	SetRelay(detour N.Dialer) Outbound
+}

common/dialer/detour.go

@@ -23,6 +23,12 @@ func NewDetour(router adapter.Router, detour string) N.Dialer {
 	return &DetourDialer{router: router, detour: detour}
 }
 
+func NewDetourWithDialer(router adapter.Router, detour adapter.Outbound) N.Dialer {
+	d := DetourDialer{router: router, detour: detour.Tag()}
+	d.initOnce.Do(func() { d.dialer = detour })
+	return &d
+}
+
 func (d *DetourDialer) Start() error {
 	_, err := d.Dialer()
 	return err

constant/proxy.go

@@ -28,6 +28,7 @@ const (
 const (
 	TypeSelector = "selector"
 	TypeURLTest  = "urltest"
+	TypeRelay    = "relay"
 )
 
 func ProxyDisplayName(proxyType string) string {
@@ -72,6 +73,8 @@ func ProxyDisplayName(proxyType string) string {
 		return "Selector"
 	case TypeURLTest:
 		return "URLTest"
+	case TypeRelay:
+		return "Relay"
 	default:
 		return "Unknown"
 	}

docs/configuration/outbound/index.md

@@ -35,6 +35,7 @@
 | `dns`          | [DNS](./dns/)                   |
 | `selector`     | [Selector](./selector/)         |
 | `urltest`      | [URLTest](./urltest/)           |
+| `relay`        | [Relay](./relay)               |
 
 #### tag
 

docs/configuration/outbound/index.zh.md

@@ -35,6 +35,7 @@
 | `dns`          | [DNS](./dns/)                   |
 | `selector`     | [Selector](./selector/)         |
 | `urltest`      | [URLTest](./urltest/)           |
+| `relay`        | [Relay](./relay)               |
 
 #### tag
 

docs/configuration/outbound/relay.md

@@ -0,0 +1,29 @@
+### Structure
+
+```json
+{
+  "type": "relay",
+  "tag": "relay",
+
+  "outbounds": [
+    "proxy-a",
+    "proxy-b",
+    "proxy-c"
+  ],
+  "interrupt_exist_connections": false
+}
+```
+
+### Fields
+
+#### outbounds
+
+==Required==
+
+List of outbound tags to relay.
+
+#### interrupt_exist_connections
+
+Interrupt existing connections when the selected outbound has changed.
+
+Only inbound connections are affected by this setting, internal connections will always be interrupted.

docs/configuration/outbound/relay.zh.md

@@ -0,0 +1,29 @@
+### 结构
+
+```json
+{
+  "type": "relay",
+  "tag": "relay",
+
+  "outbounds": [
+    "proxy-a",
+    "proxy-b",
+    "proxy-c"
+  ],
+  "interrupt_exist_connections": false
+}
+```
+
+### 字段
+
+#### outbounds
+
+==必填==
+
+用于链接的出站标签列表。
+
+#### interrupt_exist_connections
+
+当选定的出站发生更改时，中断现有连接。
+
+仅入站连接受此设置影响，内部连接将始终被中断。

option/group.go

@@ -24,3 +24,8 @@ type URLTestOutboundOptions struct {
 	IdleTimeout               Duration `json:"idle_timeout,omitempty"`
 	InterruptExistConnections bool     `json:"interrupt_exist_connections,omitempty"`
 }
+
+type RelayOutboundOptions struct {
+	Outbounds                 []string `json:"outbounds"`
+	InterruptExistConnections bool     `json:"interrupt_exist_connections,omitempty"`
+}

option/outbound.go

@@ -27,6 +27,7 @@ type _Outbound struct {
 	Hysteria2Options    Hysteria2OutboundOptions    `json:"-"`
 	SelectorOptions     SelectorOutboundOptions     `json:"-"`
 	URLTestOptions      URLTestOutboundOptions      `json:"-"`
+	RelayOptions        RelayOutboundOptions        `json:"-"`
 }
 
 type Outbound _Outbound
@@ -70,6 +71,8 @@ func (h *Outbound) RawOptions() (any, error) {
 		rawOptionsPtr = &h.SelectorOptions
 	case C.TypeURLTest:
 		rawOptionsPtr = &h.URLTestOptions
+	case C.TypeRelay:
+		rawOptionsPtr = &h.RelayOptions
 	case "":
 		return nil, E.New("missing outbound type")
 	default:

outbound/builder.go

@@ -59,6 +59,8 @@ func New(ctx context.Context, router adapter.Router, logger log.ContextLogger, t
 		return NewSelector(ctx, router, logger, tag, options.SelectorOptions)
 	case C.TypeURLTest:
 		return NewURLTest(ctx, router, logger, tag, options.URLTestOptions)
+	case C.TypeRelay:
+		return NewRelay(router, logger, tag, options.RelayOptions)
 	default:
 		return nil, E.New("unknown outbound type: ", options.Type)
 	}

outbound/http.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net"
 	"os"
+	"reflect"
 
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/common/dialer"
@@ -17,7 +18,10 @@ import (
 	sHTTP "github.com/sagernet/sing/protocol/http"
 )
 
-var _ adapter.Outbound = (*HTTP)(nil)
+var (
+	_ adapter.Outbound      = (*HTTP)(nil)
+	_ adapter.OutboundRelay = (*HTTP)(nil)
+)
 
 type HTTP struct {
 	myOutboundAdapter
@@ -73,3 +77,15 @@ func (h *HTTP) NewConnection(ctx context.Context, conn net.Conn, metadata adapte
 func (h *HTTP) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
 	return os.ErrInvalid
 }
+
+func (h *HTTP) SetRelay(detour N.Dialer) adapter.Outbound {
+	c := *h.client
+	client := c
+	r := reflect.ValueOf(client)
+	r.FieldByName("dialer").Set(reflect.ValueOf(detour))
+	outbound := HTTP{
+		myOutboundAdapter: h.myOutboundAdapter,
+		client:            &client,
+	}
+	return &outbound
+}

outbound/hysteria.go

@@ -6,6 +6,7 @@ import (
 	"context"
 	"net"
 	"os"
+	"reflect"
 
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/common/dialer"
@@ -24,6 +25,7 @@ import (
 
 var (
 	_ adapter.Outbound                = (*Hysteria)(nil)
+	_ adapter.OutboundRelay           = (*Hysteria)(nil)
 	_ adapter.InterfaceUpdateListener = (*Hysteria)(nil)
 )
 
@@ -138,3 +140,15 @@ func (h *Hysteria) InterfaceUpdated() {
 func (h *Hysteria) Close() error {
 	return h.client.CloseWithError(os.ErrClosed)
 }
+
+func (h *Hysteria) SetRelay(detour N.Dialer) adapter.Outbound {
+	c := *h.client
+	client := c
+	r := reflect.ValueOf(client)
+	r.FieldByName("dialer").Set(reflect.ValueOf(detour))
+	outbound := Hysteria{
+		myOutboundAdapter: h.myOutboundAdapter,
+		client:            &client,
+	}
+	return &outbound
+}

outbound/hysteria2.go

@@ -6,6 +6,7 @@ import (
 	"context"
 	"net"
 	"os"
+	"reflect"
 
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/common/dialer"
@@ -24,6 +25,7 @@ import (
 
 var (
 	_ adapter.Outbound                = (*Hysteria2)(nil)
+	_ adapter.OutboundRelay           = (*Hysteria2)(nil)
 	_ adapter.InterfaceUpdateListener = (*Hysteria2)(nil)
 )
 
@@ -124,3 +126,15 @@ func (h *Hysteria2) InterfaceUpdated() {
 func (h *Hysteria2) Close() error {
 	return h.client.CloseWithError(os.ErrClosed)
 }
+
+func (h *Hysteria2) SetRelay(detour N.Dialer) adapter.Outbound {
+	c := *h.client
+	client := c
+	r := reflect.ValueOf(client)
+	r.FieldByName("dialer").Set(reflect.ValueOf(detour))
+	outbound := Hysteria2{
+		myOutboundAdapter: h.myOutboundAdapter,
+		client:            &client,
+	}
+	return &outbound
+}

outbound/relay.go

@@ -0,0 +1,133 @@
+package outbound
+
+import (
+	"context"
+	"net"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/dialer"
+	"github.com/sagernet/sing-box/common/interrupt"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var (
+	_ adapter.Outbound      = (*Relay)(nil)
+	_ adapter.OutboundGroup = (*Relay)(nil)
+	_ adapter.RelayGroup    = (*Relay)(nil)
+)
+
+type Relay struct {
+	myOutboundAdapter
+	tags                         []string
+	interruptGroup               *interrupt.Group
+	interruptExternalConnections bool
+}
+
+func NewRelay(router adapter.Router, logger log.ContextLogger, tag string, options option.RelayOutboundOptions) (*Relay, error) {
+	outbound := &Relay{
+		myOutboundAdapter: myOutboundAdapter{
+			protocol:     C.TypeRelay,
+			router:       router,
+			logger:       logger,
+			tag:          tag,
+			dependencies: options.Outbounds,
+		},
+		tags:                         options.Outbounds,
+		interruptGroup:               interrupt.NewGroup(),
+		interruptExternalConnections: options.InterruptExistConnections,
+	}
+	if len(outbound.tags) == 0 {
+		return nil, E.New("missing tags")
+	}
+	return outbound, nil
+}
+
+func (r *Relay) Network() []string {
+	detour, _ := r.router.Outbound(r.tags[0])
+	return detour.Network()
+}
+
+func (r *Relay) Start() error {
+	for i, tag := range r.tags {
+		outbound, loaded := r.router.Outbound(tag)
+		if !loaded {
+			return E.New("outbound ", i, " not found: ", tag)
+		}
+		if _, isRelay := outbound.(adapter.RelayGroup); isRelay {
+			return E.New("relay outbound invalid: ", tag)
+		}
+	}
+	return nil
+}
+
+func (r *Relay) Now() string {
+	return ""
+}
+
+func (r *Relay) All() []string {
+	return r.tags
+}
+
+func (s *Relay) UpdateOutbounds(tag string) error {
+	return nil
+}
+
+func (s *Relay) IsRelay() bool {
+	return true
+}
+
+func (r *Relay) SelectedOutbound(network string) adapter.Outbound {
+	detour, _ := r.router.Outbound(r.tags[len(r.tags)-1])
+	return detour
+}
+
+func (r *Relay) createRelayChain(network string) adapter.Outbound {
+	len := len(r.tags)
+	detour, _ := r.router.Outbound(r.tags[0])
+	tag := RealOutboundTag(detour, network)
+	detour, _ = r.router.Outbound(tag)
+	for i := 1; i < len; i++ {
+		out, _ := r.router.Outbound(r.tags[i])
+		tag := RealOutboundTag(out, network)
+		out, _ = r.router.Outbound(tag)
+		outbound := out.(adapter.OutboundRelay)
+		d := dialer.NewDetourWithDialer(r.router, detour)
+		detour = outbound.SetRelay(d)
+	}
+	return detour
+}
+
+func (r *Relay) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	detour := r.createRelayChain(network)
+	conn, err := detour.DialContext(ctx, network, destination)
+	if err != nil {
+		return nil, err
+	}
+	return r.interruptGroup.NewConn(conn, interrupt.IsExternalConnectionFromContext(ctx)), nil
+}
+
+func (r *Relay) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	detour := r.createRelayChain(N.NetworkUDP)
+	conn, err := detour.ListenPacket(ctx, destination)
+	if err != nil {
+		return nil, err
+	}
+	return r.interruptGroup.NewPacketConn(conn, interrupt.IsExternalConnectionFromContext(ctx)), nil
+}
+
+func (r *Relay) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	detour := r.createRelayChain(metadata.Network)
+	ctx = interrupt.ContextWithIsExternalConnection(ctx)
+	return detour.NewConnection(ctx, conn, metadata)
+}
+
+func (r *Relay) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	detour := r.createRelayChain(metadata.Network)
+	ctx = interrupt.ContextWithIsExternalConnection(ctx)
+	return detour.NewPacketConnection(ctx, conn, metadata)
+}