Add ping retry and handle ping exception

main.go

@@ -59,39 +59,86 @@ func fixKey(key string) string {
 	return hex.EncodeToString(decoded)
 }
 
-func ping(tnet *netstack.Net, dst string) {
+func ping(tnet *netstack.Net, dst string) error {
 	logger.Info("Pinging %s", dst)
 	socket, err := tnet.Dial("ping4", dst)
 	if err != nil {
-		logger.Error("Failed to create ICMP socket: %v", err)
+		return fmt.Errorf("failed to create ICMP socket: %w", err)
 	}
+	defer socket.Close()
+
 	requestPing := icmp.Echo{
 		Seq:  rand.Intn(1 << 16),
 		Data: []byte("gopher burrow"),
 	}
-	icmpBytes, _ := (&icmp.Message{Type: ipv4.ICMPTypeEcho, Code: 0, Body: &requestPing}).Marshal(nil)
-	socket.SetReadDeadline(time.Now().Add(time.Second * 10))
+
+	icmpBytes, err := (&icmp.Message{Type: ipv4.ICMPTypeEcho, Code: 0, Body: &requestPing}).Marshal(nil)
+	if err != nil {
+		return fmt.Errorf("failed to marshal ICMP message: %w", err)
+	}
+
+	if err := socket.SetReadDeadline(time.Now().Add(time.Second * 10)); err != nil {
+		return fmt.Errorf("failed to set read deadline: %w", err)
+	}
+
 	start := time.Now()
 	_, err = socket.Write(icmpBytes)
 	if err != nil {
-		logger.Error("Failed to write ICMP packet: %v", err)
+		return fmt.Errorf("failed to write ICMP packet: %w", err)
 	}
+
 	n, err := socket.Read(icmpBytes[:])
 	if err != nil {
-		logger.Error("Failed to read ICMP packet: %v", err)
+		return fmt.Errorf("failed to read ICMP packet: %w", err)
 	}
+
 	replyPacket, err := icmp.ParseMessage(1, icmpBytes[:n])
 	if err != nil {
-		logger.Error("Failed to parse ICMP packet: %v", err)
+		return fmt.Errorf("failed to parse ICMP packet: %w", err)
 	}
+
 	replyPing, ok := replyPacket.Body.(*icmp.Echo)
 	if !ok {
-		logger.Error("invalid reply type: %v", replyPacket)
+		return fmt.Errorf("invalid reply type: got %T, want *icmp.Echo", replyPacket.Body)
 	}
+
 	if !bytes.Equal(replyPing.Data, requestPing.Data) || replyPing.Seq != requestPing.Seq {
-		logger.Error("invalid ping reply: %v", replyPing)
+		return fmt.Errorf("invalid ping reply: got seq=%d data=%q, want seq=%d data=%q",
+			replyPing.Seq, replyPing.Data, requestPing.Seq, requestPing.Data)
 	}
+
 	logger.Info("Ping latency: %v", time.Since(start))
+	return nil
+}
+
+func pingWithRetry(tnet *netstack.Net, dst string) error {
+	const (
+		maxAttempts = 5
+		retryDelay  = 2 * time.Second
+	)
+
+	var lastErr error
+	for attempt := 1; attempt <= maxAttempts; attempt++ {
+		logger.Info("Ping attempt %d of %d", attempt, maxAttempts)
+
+		if err := ping(tnet, dst); err != nil {
+			lastErr = err
+			logger.Warn("Ping attempt %d failed: %v", attempt, err)
+
+			if attempt < maxAttempts {
+				time.Sleep(retryDelay)
+				continue
+			}
+			return fmt.Errorf("all ping attempts failed after %d tries, last error: %w",
+				maxAttempts, lastErr)
+		}
+
+		// Successful ping
+		return nil
+	}
+
+	// This shouldn't be reached due to the return in the loop, but added for completeness
+	return fmt.Errorf("unexpected error: all ping attempts failed")
 }
 
 func parseLogLevel(level string) logger.LogLevel {
@@ -237,7 +284,12 @@ func main() {
 
 		if connected {
 			logger.Info("Already connected! Put I will send a ping anyway...")
-			ping(tnet, wgData.ServerIP)
+			// ping(tnet, wgData.ServerIP)
+			err = pingWithRetry(tnet, wgData.ServerIP)
+			if err != nil {
+				// Handle complete failure after all retries
+				logger.Error("Failed to ping %s: %v", wgData.ServerIP, err)
+			}
 			return
 		}
 
@@ -293,7 +345,12 @@ persistent_keepalive_interval=5`, fixKey(fmt.Sprintf("%s", privateKey)), fixKey(
 
 		logger.Info("WireGuard device created. Lets ping the server now...")
 		// Ping to bring the tunnel up on the server side quickly
-		ping(tnet, wgData.ServerIP)
+		// ping(tnet, wgData.ServerIP)
+		err = pingWithRetry(tnet, wgData.ServerIP)
+		if err != nil {
+			// Handle complete failure after all retries
+			logger.Error("Failed to ping %s: %v", wgData.ServerIP, err)
+		}
 
 		// Create proxy manager
 		pm = proxy.NewProxyManager(tnet)