fix incorrect error handling logic when a JWT is created wrongly; closes pterodactyl/panel#3295

Prior to this logic not only was the error response incorrect for events, but we registered event listeners before the authentication event; so if auth failed we flooded the socket with tons of output that was never going to be sent anyways.

This change now waits to register listeners until the socket is fully authenticated and we're guaranteed to have a token present.

router/router_server_ws.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"time"
 
-	"emperror.dev/errors"
 	"github.com/gin-gonic/gin"
 	ws "github.com/gorilla/websocket"
 
@@ -64,17 +63,6 @@ func getServerWebsocket(c *gin.Context) {
 		}
 	}()
 
-	go func() {
-		if err := handler.ListenForServerEvents(ctx); err != nil {
-			handler.Logger().Warn("error while processing server event; closing websocket connection")
-			if err := handler.Connection.Close(); err != nil {
-				handler.Logger().WithField("error", errors.WithStack(err)).Error("error closing websocket connection")
-			}
-		}
-	}()
-
-	go handler.ListenForExpiration(ctx)
-
 	for {
 		j := websocket.Message{}
 
@@ -94,7 +82,7 @@ func getServerWebsocket(c *gin.Context) {
 		}
 
 		go func(msg websocket.Message) {
-			if err := handler.HandleInbound(msg); err != nil {
+			if err := handler.HandleInbound(ctx, msg); err != nil {
 				handler.SendErrorJson(msg, err)
 			}
 		}(j)

router/websocket/listeners.go

@@ -10,11 +10,37 @@ import (
 	"github.com/pterodactyl/wings/server"
 )
 
+// RegisterListenerEvents will setup the server event listeners and expiration
+// timers. This is only triggered on first authentication with the websocket,
+// reconnections will not call it.
+//
+// This needs to be called once the socket is properly authenticated otherwise
+// you'll get a flood of error spam in the output that doesn't make sense because
+// Docker events being output to the socket will fail when it hasn't been
+// properly initialized yet.
+//
+// @see https://github.com/pterodactyl/panel/issues/3295
+func (h *Handler) registerListenerEvents(ctx context.Context) {
+	h.Logger().Debug("registering event listeners for connection")
+
+	go func() {
+		if err := h.listenForServerEvents(ctx); err != nil {
+			h.Logger().Warn("error while processing server event; closing websocket connection")
+			if err := h.Connection.Close(); err != nil {
+				h.Logger().WithField("error", errors.WithStack(err)).Error("error closing websocket connection")
+			}
+		}
+	}()
+
+	go h.listenForExpiration(ctx)
+}
+
+
 // ListenForExpiration checks the time to expiration on the JWT every 30 seconds
 // until the token has expired. If we are within 3 minutes of the token expiring,
 // send a notice over the socket that it is expiring soon. If it has expired,
 // send that notice as well.
-func (h *Handler) ListenForExpiration(ctx context.Context) {
+func (h *Handler) listenForExpiration(ctx context.Context) {
 	// Make a ticker and completion channel that is used to continuously poll the
 	// JWT stored in the session to send events to the socket when it is expiring.
 	ticker := time.NewTicker(time.Second * 30)
@@ -54,12 +80,11 @@ var e = []string{
 // ListenForServerEvents will listen for different events happening on a server
 // and send them along to the connected websocket client. This function will
 // block until the context provided to it is canceled.
-func (h *Handler) ListenForServerEvents(pctx context.Context) error {
+func (h *Handler) listenForServerEvents(pctx context.Context) error {
 	var o sync.Once
 	var err error
 	ctx, cancel := context.WithCancel(pctx)
 
-	h.Logger().Debug("listening for server events")
 	callback := func(e events.Event) {
 		if sendErr := h.SendJson(&Message{Event: e.Topic, Args: []string{e.Data}}); sendErr != nil {
 			h.Logger().WithField("event", e.Topic).WithField("error", sendErr).Error("failed to send event over server websocket")

router/websocket/websocket.go

@@ -269,7 +269,7 @@ func (h *Handler) setJwt(token *tokens.WebsocketPayload) {
 }
 
 // HandleInbound handles an inbound socket request and route it to the proper action.
-func (h *Handler) HandleInbound(m Message) error {
+func (h *Handler) HandleInbound(ctx context.Context, m Message) error {
 	if m.Event != AuthenticationEvent {
 		if err := h.TokenValid(); err != nil {
 			h.unsafeSendJson(Message{
@@ -285,13 +285,6 @@ func (h *Handler) HandleInbound(m Message) error {
 		{
 			token, err := NewTokenPayload([]byte(strings.Join(m.Args, "")))
 			if err != nil {
-				// If the error says the JWT expired, send a token expired
-				// event and hopefully the client renews the token.
-				if err == jwt.ErrExpValidation {
-					h.SendJson(&Message{Event: TokenExpiredEvent})
-					return nil
-				}
-
 				return err
 			}
 
@@ -304,10 +297,7 @@ func (h *Handler) HandleInbound(m Message) error {
 			h.setJwt(token)
 
 			// Tell the client they authenticated successfully.
-			h.unsafeSendJson(Message{
-				Event: AuthenticationSuccessEvent,
-				Args:  []string{},
-			})
+			h.unsafeSendJson(Message{Event: AuthenticationSuccessEvent})
 
 			// Check if the client was refreshing their authentication token
 			// instead of authenticating for the first time.
@@ -317,6 +307,11 @@ func (h *Handler) HandleInbound(m Message) error {
 				return nil
 			}
 
+			// Now that we've authenticated with the token and confirmed that we're not
+			// reconnecting to the socket, register the event listeners for the server and
+			// the token expiration.
+			h.registerListenerEvents(ctx)
+
 			// On every authentication event, send the current server status back
 			// to the client. :)
 			state := h.server.Environment.State()