fix(rpc): bind io streams to target agents

Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>

cmd/dashboard/controller/fm.go

@@ -46,7 +46,7 @@ func createFM(c *gin.Context) (*model.CreateFMResponse, error) {
 		return nil, err
 	}
 
-	rpc.NezhaHandlerSingleton.CreateStream(streamId, getUid(c))
+	rpc.NezhaHandlerSingleton.CreateStream(streamId, getUid(c), server.ID)
 
 	fmData, _ := json.Marshal(&model.TaskFM{
 		StreamID: streamId,

cmd/dashboard/controller/stream_ownership_test.go

@@ -50,7 +50,7 @@ func TestTerminalStreamRejectsForeignMember(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	ensureLocalizerForStreamTests(t)
 	rpc.NezhaHandlerSingleton = rpc.NewNezhaHandler()
-	rpc.NezhaHandlerSingleton.CreateStream("alice-terminal", 100)
+	rpc.NezhaHandlerSingleton.CreateStream("alice-terminal", 100, 1)
 
 	r := gin.New()
 	r.Use(func(c *gin.Context) {
@@ -76,7 +76,7 @@ func TestFMStreamRejectsForeignMember(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	ensureLocalizerForStreamTests(t)
 	rpc.NezhaHandlerSingleton = rpc.NewNezhaHandler()
-	rpc.NezhaHandlerSingleton.CreateStream("alice-fm", 100)
+	rpc.NezhaHandlerSingleton.CreateStream("alice-fm", 100, 1)
 
 	r := gin.New()
 	r.Use(func(c *gin.Context) {
@@ -160,4 +160,3 @@ func TestWriteOauth2StateCookieIsHttpOnly(t *testing.T) {
 		t.Fatalf("nz-o2s must be HttpOnly to prevent XSS reading OAuth state, got %q", header)
 	}
 }
-

cmd/dashboard/controller/terminal.go

@@ -44,7 +44,7 @@ func createTerminal(c *gin.Context) (*model.CreateTerminalResponse, error) {
 		return nil, err
 	}
 
-	rpc.NezhaHandlerSingleton.CreateStream(streamId, getUid(c))
+	rpc.NezhaHandlerSingleton.CreateStream(streamId, getUid(c), server.ID)
 
 	terminalData, _ := json.Marshal(&model.TerminalTask{
 		StreamID: streamId,

cmd/dashboard/rpc/rpc.go

@@ -140,8 +140,11 @@ func ServeNAT(w http.ResponseWriter, r *http.Request, natConfig *model.NAT) {
 
 	// NAT streams are anonymous HTTP-facing tunnels; they are NOT reachable
 	// via /ws/terminal or /ws/file (which check stream ownership), so the
-	// creator user ID does not need to identify a real user.
-	rpcService.NezhaHandlerSingleton.CreateStream(streamId, 0)
+	// creator user ID does not need to identify a real user. The targetServerID
+	// IS required though — the receiving agent must prove it is the server the
+	// NAT config addressed, otherwise any agent that snoops the streamId can
+	// answer NAT traffic on behalf of an unrelated host.
+	rpcService.NezhaHandlerSingleton.CreateStream(streamId, 0, server.ID)
 	defer rpcService.NezhaHandlerSingleton.CloseStream(streamId)
 
 	taskData, err := json.Marshal(model.TaskNAT{