VLESS Reverse Proxy: Add "sniffing" to outbound's "reverse" (which is actually an inbound) (#5837)

Closes https://github.com/XTLS/Xray-core/issues/5662

---------

Co-authored-by: RPRX <63339210+RPRX@users.noreply.github.com>

proxy/vless/account.pb.go

@@ -7,6 +7,7 @@
 package vless
 
 import (
+	proxyman "github.com/xtls/xray-core/app/proxyman"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
@@ -22,8 +23,9 @@ const (
 )
 
 type Reverse struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Tag           string                 `protobuf:"bytes,1,opt,name=tag,proto3" json:"tag,omitempty"`
+	state         protoimpl.MessageState   `protogen:"open.v1"`
+	Tag           string                   `protobuf:"bytes,1,opt,name=tag,proto3" json:"tag,omitempty"`
+	Sniffing      *proxyman.SniffingConfig `protobuf:"bytes,2,opt,name=sniffing,proto3" json:"sniffing,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -65,6 +67,13 @@ func (x *Reverse) GetTag() string {
 	return ""
 }
 
+func (x *Reverse) GetSniffing() *proxyman.SniffingConfig {
+	if x != nil {
+		return x.Sniffing
+	}
+	return nil
+}
+
 type Account struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
 	// ID of the account, in the form of a UUID, e.g., "66ad4540-b58c-4ad2-9926-ea63445a9b57".
@@ -179,9 +188,10 @@ var File_proxy_vless_account_proto protoreflect.FileDescriptor
 
 const file_proxy_vless_account_proto_rawDesc = "" +
 	"\n" +
-	"\x19proxy/vless/account.proto\x12\x10xray.proxy.vless\"\x1b\n" +
+	"\x19proxy/vless/account.proto\x12\x10xray.proxy.vless\x1a\x19app/proxyman/config.proto\"Z\n" +
 	"\aReverse\x12\x10\n" +
-	"\x03tag\x18\x01 \x01(\tR\x03tag\"\x86\x02\n" +
+	"\x03tag\x18\x01 \x01(\tR\x03tag\x12=\n" +
+	"\bsniffing\x18\x02 \x01(\v2!.xray.app.proxyman.SniffingConfigR\bsniffing\"\x86\x02\n" +
 	"\aAccount\x12\x0e\n" +
 	"\x02id\x18\x01 \x01(\tR\x02id\x12\x12\n" +
 	"\x04flow\x18\x02 \x01(\tR\x04flow\x12\x1e\n" +
@@ -210,16 +220,18 @@ func file_proxy_vless_account_proto_rawDescGZIP() []byte {
 
 var file_proxy_vless_account_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
 var file_proxy_vless_account_proto_goTypes = []any{
-	(*Reverse)(nil), // 0: xray.proxy.vless.Reverse
-	(*Account)(nil), // 1: xray.proxy.vless.Account
+	(*Reverse)(nil),                 // 0: xray.proxy.vless.Reverse
+	(*Account)(nil),                 // 1: xray.proxy.vless.Account
+	(*proxyman.SniffingConfig)(nil), // 2: xray.app.proxyman.SniffingConfig
 }
 var file_proxy_vless_account_proto_depIdxs = []int32{
-	0, // 0: xray.proxy.vless.Account.reverse:type_name -> xray.proxy.vless.Reverse
-	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
+	2, // 0: xray.proxy.vless.Reverse.sniffing:type_name -> xray.app.proxyman.SniffingConfig
+	0, // 1: xray.proxy.vless.Account.reverse:type_name -> xray.proxy.vless.Reverse
+	2, // [2:2] is the sub-list for method output_type
+	2, // [2:2] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
 }
 
 func init() { file_proxy_vless_account_proto_init() }

proxy/vless/account.proto

@@ -6,8 +6,11 @@ option go_package = "github.com/xtls/xray-core/proxy/vless";
 option java_package = "com.xray.proxy.vless";
 option java_multiple_files = true;
 
+import "app/proxyman/config.proto";
+
 message Reverse {
   string tag = 1;
+  xray.app.proxyman.SniffingConfig sniffing = 2;
 }
 
 message Account {

proxy/vless/outbound/outbound.go

@@ -97,14 +97,26 @@ func New(ctx context.Context, config *Config) (*Handler, error) {
 	}
 
 	if a.Reverse != nil {
+		rvsCtx := session.ContextWithInbound(ctx, &session.Inbound{
+			Tag:  a.Reverse.Tag,
+			User: handler.server.User, // TODO: email
+		})
+		if sc := a.Reverse.Sniffing; sc != nil && sc.Enabled {
+			rvsCtx = session.ContextWithContent(rvsCtx, &session.Content{
+				SniffingRequest: session.SniffingRequest{
+					Enabled:                        sc.Enabled,
+					OverrideDestinationForProtocol: sc.DestinationOverride,
+					ExcludeForDomain:               sc.DomainsExcluded,
+					MetadataOnly:                   sc.MetadataOnly,
+					RouteOnly:                      sc.RouteOnly,
+				},
+			})
+		}
 		handler.reverse = &Reverse{
 			tag:        a.Reverse.Tag,
 			dispatcher: v.GetFeature(routing.DispatcherType()).(routing.Dispatcher),
-			ctx: session.ContextWithInbound(ctx, &session.Inbound{
-				Tag:  a.Reverse.Tag,
-				User: handler.server.User, // TODO: email
-			}),
-			handler: handler,
+			ctx:        rvsCtx,
+			handler:    handler,
 		}
 		handler.reverse.monitorTask = &task.Periodic{
 			Execute:  handler.reverse.monitor,