fix(shutdown): Fix shutdown command

server/udp.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"encoding/hex"
 	"fmt"
 	"net"
 	"time"
@@ -69,13 +70,30 @@ func (s *UDPServer) Start(done chan bool) {
 				continue
 			}
 
+			packetData := buffer[:n]
+
+			// Debug: Display packet content
+			hexDump := hex.EncodeToString(packetData)
+			// Also try to show as string (for auth part)
+			stringPreview := ""
+			if len(packetData) > 0 && packetData[0] < 128 {
+				// Only show string preview if it looks like printable ASCII
+				maxLen := len(packetData)
+				if maxLen > 100 {
+					maxLen = 100
+				}
+				stringPreview = string(packetData[:maxLen])
+			}
+
 			masterlog.Info("Received UDP packet", map[string]interface{}{
-				"bytes":   n,
-				"address": clientAddr,
+				"bytes":          n,
+				"address":        clientAddr,
+				"hex":            hexDump,
+				"string_preview": stringPreview,
 			})
 
 			// Check authentication and magic packet
-			if s.isValidAuthenticatedMagicPacket(buffer[:n]) {
+			if s.isValidAuthenticatedMagicPacket(packetData) {
 				masterlog.Info("Authenticated Magic Packet detected! Shutting down system...", map[string]interface{}{
 					"address": clientAddr,
 				})
@@ -94,14 +112,38 @@ func (s *UDPServer) Start(done chan bool) {
 func (s *UDPServer) isValidAuthenticatedMagicPacket(data []byte) bool {
 	username, password, magicPacketData, ok := magicpacket.ExtractAuthFromPacket(data)
 	if !ok {
+		masterlog.Info("Packet does not contain valid auth format", map[string]interface{}{
+			"packet_size": len(data),
+		})
 		return false
 	}
 
+	masterlog.Info("Extracted authentication from packet", map[string]interface{}{
+		"username":          username,
+		"password_length":   len(password),
+		"magic_packet_size": len(magicPacketData),
+	})
+
 	// Verify authentication
 	if !s.authenticator.Verify(username, password) {
+		masterlog.Info("Authentication failed", map[string]interface{}{
+			"username": username,
+		})
 		return false
 	}
 
+	masterlog.Info("Authentication successful", map[string]interface{}{
+		"username": username,
+	})
+
 	// Check if it's a valid magic packet
-	return magicpacket.IsMagicPacket(magicPacketData)
+	isValid := magicpacket.IsMagicPacket(magicPacketData)
+	if !isValid {
+		masterlog.Info("Magic packet validation failed", map[string]interface{}{
+			"magic_packet_size": len(magicPacketData),
+			"magic_packet_hex":  hex.EncodeToString(magicPacketData),
+		})
+	}
+
+	return isValid
 }