Handle server version and prevent backward issues with clients

main.go

@@ -1389,7 +1389,12 @@ persistent_keepalive_interval=5`, util.FixKey(privateKey.String()), util.FixKey(
 				"noCloud": noCloud,
 			}, 3*time.Second)
 			logger.Debug("Requesting exit nodes from server")
-			clientsOnConnect()
+
+			if client.GetServerVersion() != "" { // to prevent issues with running newt > 1.7 versions with older servers
+				clientsOnConnect()
+			} else {
+				logger.Warn("CLIENTS WILL NOT WORK ON THIS VERSION OF NEWT WITH THIS VERSION OF PANGOLIN, PLEASE UPDATE THE SERVER TO 1.13 OR HIGHER OR DOWNGRADE NEWT")
+			}
 		}
 
 		// Send registration message to the server for backward compatibility

websocket/client.go

@@ -46,6 +46,7 @@ type Client struct {
 	metricsCtxMu      sync.RWMutex
 	metricsCtx        context.Context
 	configNeedsSave   bool // Flag to track if config needs to be saved
+	serverVersion     string
 }
 
 type ClientOption func(*Client)
@@ -149,6 +150,10 @@ func (c *Client) GetConfig() *Config {
 	return c.config
 }
 
+func (c *Client) GetServerVersion() string {
+	return c.serverVersion
+}
+
 // Connect establishes the WebSocket connection
 func (c *Client) Connect() error {
 	go c.connectWithRetry()
@@ -351,9 +356,11 @@ func (c *Client) getToken() (string, error) {
 	}
 	defer resp.Body.Close()
 
+	body, _ := io.ReadAll(resp.Body)
+	logger.Debug("Token response body: %s", string(body))
+
 	if resp.StatusCode != http.StatusOK {
-		body, _ := io.ReadAll(resp.Body)
-		logger.Error("Failed to get token with status code: %d, body: %s", resp.StatusCode, string(body))
+		logger.Error("Failed to get token with status code: %d", resp.StatusCode)
 		telemetry.IncConnAttempt(ctx, "auth", "failure")
 		etype := "io_error"
 		if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
@@ -368,7 +375,7 @@ func (c *Client) getToken() (string, error) {
 	}
 
 	var tokenResp TokenResponse
-	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
+	if err := json.Unmarshal(body, &tokenResp); err != nil {
 		logger.Error("Failed to decode token response.")
 		return "", fmt.Errorf("failed to decode token response: %w", err)
 	}
@@ -381,6 +388,11 @@ func (c *Client) getToken() (string, error) {
 		return "", fmt.Errorf("received empty token from server")
 	}
 
+	// print server version
+	logger.Info("Server version: %s", tokenResp.Data.ServerVersion)
+
+	c.serverVersion = tokenResp.Data.ServerVersion
+
 	logger.Debug("Received token: %s", tokenResp.Data.Token)
 	telemetry.IncConnAttempt(ctx, "auth", "success")
 

websocket/types.go

@@ -9,7 +9,8 @@ type Config struct {
 
 type TokenResponse struct {
 	Data struct {
-		Token string `json:"token"`
+		Token         string `json:"token"`
+		ServerVersion string `json:"serverVersion"`
 	} `json:"data"`
 	Success bool   `json:"success"`
 	Message string `json:"message"`