Normally when I run wpa_supplicant I'll get some output like this:
Successfully initialized wpa_supplicant
ioctl[SIOCSIWAP]: Operation not permitted
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWENCODEEXT]: Invalid argument
wlan3: Trying to associate with 9c:3d:cf:fb:95:96 (SSID='Bell420' freq=2462 MHz)
wlan3: Association request to the driver failed
wlan3: Associated with 9c:3d:cf:fb:95:96
wlan3: Authentication with 9c:3d:cf:fb:95:96 timed out.
ioctl[SIOCSIWAP]: Operation not permitted
wlan3: CTRL-EVENT-DISCONNECTED bssid=9c:3d:cf:fb:95:96 reason=3 locally_generated=1
wlan3: WPA: 4-Way Handshake failed - pre-shared key may be incorrect
The problem is it just keeps trying over and over.
Is there a way I can tell wpa_supplicant to quit as soon as it gets an obvious error like wrong key?
I'm on an older embedded device with wpa_supplicant v2.1.
I wrote a workaround for monitoring wpa_supplicant for incorrect keys. Using grep on wpa_supplicant (with stdbuf based on Stéphane Chazelas' comment here):
# Create conf file with ssid and password
wpa_passphrase "$ssid" "$password" > /etc/wpa_supplicant/wpa_supplicant.conf
# If wifi key is wrong kill subshell
subshell=$BASHPID
(sudo stdbuf -o0 wpa_supplicant -Dwext -iwlan1 -c/etc/wpa_supplicant/wpa_supplicant.conf 2>&1 \
| grep -m 1 "pre-shared key may be incorrect" \
&& kill -s PIPE "$subshell") &
Note: the above block is inside a subshell in a script.
It seemed to work initially but over time I found sometimes it would cause the whole script to fail when the password was fine. Other times it would work as expected.
There must be a better way to do this.
Edit: Maybe I should be using wpa_cli here instead?
