Wi-Fi Protected Access (WPA) Supplicant

Updated: May 06, 2022

The WPA supplicant utility, wpa_supplicant, must be launched during startup and runs as a background process (daemon) that controls access to the Wi-Fi connection.

You must run this utility after loading the wireless device driver but before starting wpa_pps, which uses the utility to perform authentication when creating a new connection. Here, we provide a sample command for starting the service. The options needed in this case are:
  • -D—names the wireless driver
  • -t—adds timestamps to debugging messages
  • -i—specifies the interface to use (like with wpa_pps)
  • -c—provides the path to the configuration file
  • -g—provides the path to the global control interface socket

The full list of options can be obtained using the -h option for wpa_supplicant. For instance, wpa_supplicant-2.9 -h lists the options supported by version 2.9 of the utility.

The following is an example of starting the WPA supplicant utility for the Marvell Wi-Fi chip:
wpa_supplicant-2.9 -Dqwdi -t -i mrvl_mlan0 -c/var/etc/wpa_supplicant.conf \
 -g /var/run/wpa_supplicant_global &
You should then use waitfor to wait until the global control interface socket has been created before launching wpa_pps. To wait for the socket creation, use a command like this:
waitfor /var/run/wpa_supplicant_global 5
where the second argument refers to the number of seconds to wait.