Q4-Send-probe-request
===========================================

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        Topics in this section,

                * :ref:`Learnings in this section <wifi_ldd_wi-fi_dev_sta_ques4_step_1>`

                * :ref:`Version Info <wifi_ldd_wi-fi_dev_sta_ques4_step_2>`

                * :ref:`Problem Statement <wifi_ldd_wi-fi_dev_sta_ques4_step_3>`

                * :ref:`Approach and code flow <wifi_ldd_wi-fi_dev_sta_ques4_step_4>`

                * :ref:`Actual change and Patch <wifi_ldd_wi-fi_dev_sta_ques4_step_5>`

                * :ref:`Wireshark capture <wifi_ldd_wi-fi_dev_sta_ques4_step_6>`


.. _wifi_ldd_wi-fi_dev_sta_ques4_step_1:
  
.. tab-set::

   .. tab-item:: Learnings in this section

        * In this section, you are going to learn


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                * How to send a probe-request every 30 seconds


.. _wifi_ldd_wi-fi_dev_sta_ques4_step_2:

.. tab-set::
 
    .. tab-item:: Version Info

        =============================== =======================================
        #                               Version
        =============================== =======================================
        Ubuntu                          Ubuntu 22.04 64 bit
        Linux Kernel                    6.9.2
	Supplicant                      wpa_supplicant 2.10
        =============================== =======================================


.. _wifi_ldd_wi-fi_dev_sta_ques4_step_3:
  
.. tab-set::

   .. tab-item:: Problem Statement

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                * Send a probe-request every 30 seconds
		
		* Add a configuration parameter called "periodic_probe=30" in supplicant conf file

		* If "periodic_probe=0", then this feature is disabled

		* If "periodic_probe=5", then probe is sent at every 5th second


.. _wifi_ldd_wi-fi_dev_sta_ques4_step_4:
  
.. tab-set::

   .. tab-item:: Approach and code flow

	* Call flow for send a probe-request every 30 seconds

	.. literalinclude:: send_probe_req_every_30sec_callflow.txt

.. _wifi_ldd_wi-fi_dev_sta_ques4_step_5:
  
.. tab-set::

   .. tab-item:: Actual change and Patch

	* Download the below patch file

	:download:`send_probe_req_every_30sec.patch <send_probe_req_every_30sec.patch>`

	.. dropdown:: See the full content of patch file

            .. literalinclude:: send_probe_req_every_30sec.patch

	.. code-block:: shell

                test:~$ pwd
                /home/test

        * Make sure internet is available in laptop to download supplicant package

        .. code-block:: shell

                test:~$ sudo wget https://w1.fi/releases/wpa_supplicant-2.10.tar.gz

        * Create a directory

        .. code-block:: shell

                test:~$ mkdir supplicant

        * Change directory to supplicant

        .. code-block:: shell

                test:~$ cd supplicant

        * Note : Your present working directory should be supplicant

        .. code-block:: shell
        
                test:~$ pwd
                /home/test/supplicant/

        * Extract wpa_supplicant

        .. code-block:: shell

                test:~$ sudo tar -xvf ~/wpa_supplicant-2.10.tar.gz

	* Run the below command to apply patch 

	.. code-block:: shell

		test:~$ patch -p1 < send_probe_req_every_30sec.patch
		patching file wpa_supplicant-2.10/src/utils/os.h
		patching file wpa_supplicant-2.10/src/utils/os_unix.c
		patching file wpa_supplicant-2.10/wpa_supplicant/config_file.c
		patching file wpa_supplicant-2.10/wpa_supplicant/config.h
		patching file wpa_supplicant-2.10/wpa_supplicant/scan.c

	* Change directory to wpa_supplicant

	.. code-block:: shell

                test:~$ cd wpa_supplicant-2.10/wpa_supplicant/

	* Check the current working directory using pwd command

	* Make sure your current working directory is wpa_supplicant

	.. code-block:: shell

                test:~$ pwd
		/home/test/supplicant/wpa_supplicant-2.10/wpa_supplicant

	* Copy the contents of defconfig file to .config file

	.. code-block:: shell

                test:~$ sudo cp defconfig .config

	* Compile wpa_supplicant

	.. code-block:: shell

                test:~$ sudo make

	* Create run_supplicant.conf

	.. code-block:: shell

                test:~$ sudo vim ./run_supplicant.conf

		ctrl_interface=/run/wpa_supplicant
		update_config=1
		periodic_probe=30

		network={
		ssid="test_open"
		key_mgmt=NONE
		}
	
	* Run wpa_supplicant

	.. code-block:: shell

                test:~$ sudo ./wpa_supplicant -Dnl80211 -i wlan1 -c ./run_supplicant.conf



.. _wifi_ldd_wi-fi_dev_sta_ques4_step_6:
  
.. tab-set::

   .. tab-item:: Wireshark capture

	* Download file to check wireshark output

	:download:`send_probe_req_every_30sec.pcapng <send_probe_req_every_30sec.pcapng>`

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                * Check for probe-request packet

		* Apply display filter

		* wlan.addr == 02:00:00:00:01:00 && wlan.fc.type_subtype == 4

	.. image:: probe_req_wireshark_image1.png
                :alt: Diagram
                :width: 800
                :height: 400

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		* Observe the probe-request packets with 30 sec time interval


	.. image:: probe_req_wireshark_image2.png
                :alt: Diagram
                :width: 800
                :height: 400