refactor ♻️: Refactored WOL packet capture and validation logic

Improved the efficiency and readability of the WOL packet handling by refactoring the existing code. This includes restructuring the validation logic and optimizing the capture process.

tasks/main.yml

@@ -115,11 +115,11 @@
       WOL Mode: {{ wol_mode }}
       MAC Addresses: {{ wol_mac_addresses | join(', ') }}
 
-
 - name: Start tcpdump to capture WOL packet
   become: true
   ansible.builtin.shell: |
-    tcpdump -i {{ en_interfaces[0] }} -nn -c 1 udp port {{ wol_port }}
+    timeout 10 tcpdump -i {{ en_interfaces[0] }} -nn -c 1 \
+    'udp and port {{ wol_port }} and (udp[8:4] = 0xffffffff)'
   register: tcpdump_result
   async: 12
   poll: 0
@@ -142,6 +142,6 @@
 - name: Check if WOL packet was received
   ansible.builtin.assert:
     that:
-      - "'UDP' in tcpdump_status.stdout"
-    success_msg: "✅ Wake-on-LAN packet received by host"
-    fail_msg: "❌ No Wake-on-LAN packet detected"
+      - tcpdump_status.rc == 0
+    success_msg: "✅ Wake-on-LAN magic packet received by host"
+    fail_msg: "❌ Wake-on-LAN magic packet NOT detected"