Outbound: One endpoint and at most one user only (#5144)

https://github.com/XTLS/Xray-core/pull/5124#issuecomment-3281091009

Fixes https://github.com/XTLS/Xray-core/pull/5124#pullrequestreview-3218097421

proxy/vmess/outbound/command.go

@@ -1,41 +1,14 @@
 package outbound
 
 import (
-	"time"
 
-	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
-	"github.com/xtls/xray-core/proxy/vmess"
 )
 
-func (h *Handler) handleSwitchAccount(cmd *protocol.CommandSwitchAccount) {
-	rawAccount := &vmess.Account{
-		Id: cmd.ID.String(),
-		SecuritySettings: &protocol.SecurityConfig{
-			Type: protocol.SecurityType_AUTO,
-		},
-	}
-
-	account, err := rawAccount.AsAccount()
-	common.Must(err)
-	user := &protocol.MemoryUser{
-		Email:   "",
-		Level:   cmd.Level,
-		Account: account,
-	}
-	dest := net.TCPDestination(cmd.Host, cmd.Port)
-	until := time.Now().Add(time.Duration(cmd.ValidMin) * time.Minute)
-	h.serverList.AddServer(protocol.NewServerSpec(dest, protocol.BeforeTime(until), user))
-}
-
+// As a stub command consumer.
 func (h *Handler) handleCommand(dest net.Destination, cmd protocol.ResponseCommand) {
-	switch typedCommand := cmd.(type) {
-	case *protocol.CommandSwitchAccount:
-		if typedCommand.Host == nil {
-			typedCommand.Host = dest.Address
-		}
-		h.handleSwitchAccount(typedCommand)
+	switch cmd.(type) {
 	default:
 	}
 }

proxy/vmess/outbound/config.pb.go

@@ -26,7 +26,7 @@ type Config struct {
 	sizeCache     protoimpl.SizeCache
 	unknownFields protoimpl.UnknownFields
 
-	Receiver []*protocol.ServerEndpoint `protobuf:"bytes,1,rep,name=Receiver,proto3" json:"Receiver,omitempty"`
+	Receiver *protocol.ServerEndpoint `protobuf:"bytes,1,opt,name=Receiver,proto3" json:"Receiver,omitempty"`
 }
 
 func (x *Config) Reset() {
@@ -59,7 +59,7 @@ func (*Config) Descriptor() ([]byte, []int) {
 	return file_proxy_vmess_outbound_config_proto_rawDescGZIP(), []int{0}
 }
 
-func (x *Config) GetReceiver() []*protocol.ServerEndpoint {
+func (x *Config) GetReceiver() *protocol.ServerEndpoint {
 	if x != nil {
 		return x.Receiver
 	}
@@ -76,7 +76,7 @@ var file_proxy_vmess_outbound_config_proto_rawDesc = []byte{
 	0x63, 0x6f, 0x6d, 0x6d, 0x6f, 0x6e, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x63, 0x6f, 0x6c, 0x2f,
 	0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x5f, 0x73, 0x70, 0x65, 0x63, 0x2e, 0x70, 0x72, 0x6f, 0x74,
 	0x6f, 0x22, 0x4a, 0x0a, 0x06, 0x43, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x12, 0x40, 0x0a, 0x08, 0x52,
-	0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x72, 0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x24, 0x2e,
+	0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x72, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x24, 0x2e,
 	0x78, 0x72, 0x61, 0x79, 0x2e, 0x63, 0x6f, 0x6d, 0x6d, 0x6f, 0x6e, 0x2e, 0x70, 0x72, 0x6f, 0x74,
 	0x6f, 0x63, 0x6f, 0x6c, 0x2e, 0x53, 0x65, 0x72, 0x76, 0x65, 0x72, 0x45, 0x6e, 0x64, 0x70, 0x6f,
 	0x69, 0x6e, 0x74, 0x52, 0x08, 0x52, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x72, 0x42, 0x6d, 0x0a,

proxy/vmess/outbound/config.proto

@@ -9,5 +9,5 @@ option java_multiple_files = true;
 import "common/protocol/server_spec.proto";
 
 message Config {
-  repeated xray.common.protocol.ServerEndpoint Receiver = 1;
+  xray.common.protocol.ServerEndpoint Receiver = 1;
 }

proxy/vmess/outbound/outbound.go

@@ -29,27 +29,24 @@ import (
 
 // Handler is an outbound connection handler for VMess protocol.
 type Handler struct {
-	serverList    *protocol.ServerList
-	serverPicker  protocol.ServerPicker
+	server        *protocol.ServerSpec
 	policyManager policy.Manager
 	cone          bool
 }
 
 // New creates a new VMess outbound handler.
 func New(ctx context.Context, config *Config) (*Handler, error) {
-	serverList := protocol.NewServerList()
-	for _, rec := range config.Receiver {
-		s, err := protocol.NewServerSpecFromPB(rec)
-		if err != nil {
-			return nil, errors.New("failed to parse server spec").Base(err)
-		}
-		serverList.AddServer(s)
+	if config.Receiver == nil {
+		return nil, errors.New(`no vnext found`)
+	}
+	server, err := protocol.NewServerSpecFromPB(config.Receiver)
+	if err != nil {
+		return nil, errors.New("failed to get server spec").Base(err)
 	}
 
 	v := core.MustFromContext(ctx)
 	handler := &Handler{
-		serverList:    serverList,
-		serverPicker:  protocol.NewRoundRobinServerPicker(serverList),
+		server:        server,
 		policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
 		cone:          ctx.Value("cone").(bool),
 	}
@@ -67,11 +64,11 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 	ob.Name = "vmess"
 	ob.CanSpliceCopy = 3
 
-	var rec *protocol.ServerSpec
+	rec := h.server
 	var conn stat.Connection
+
 	err := retry.ExponentialBackoff(5, 200).On(func() error {
-		rec = h.serverPicker.PickServer()
-		rawConn, err := dialer.Dial(ctx, rec.Destination())
+		rawConn, err := dialer.Dial(ctx, rec.Destination)
 		if err != nil {
 			return err
 		}
@@ -85,7 +82,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 	defer conn.Close()
 
 	target := ob.Target
-	errors.LogInfo(ctx, "tunneling request to ", target, " via ", rec.Destination().NetAddr())
+	errors.LogInfo(ctx, "tunneling request to ", target, " via ", rec.Destination.NetAddr())
 
 	command := protocol.RequestCommandTCP
 	if target.Network == net.Network_UDP {
@@ -95,7 +92,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		command = protocol.RequestCommandMux
 	}
 
-	user := rec.PickUser()
+	user := rec.User
 	request := &protocol.RequestHeader{
 		Version: encoding.Version,
 		User:    user,
@@ -202,7 +199,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		if err != nil {
 			return errors.New("failed to read header").Base(err)
 		}
-		h.handleCommand(rec.Destination(), header.Command)
+		h.handleCommand(rec.Destination, header.Command)
 
 		bodyReader, err := session.DecodeResponseBody(request, reader)
 		if err != nil {