[pkg-wpa-devel] Bug#403045: wpasupplicant: race condition in wpa_action disconnect between ifdown and if_post_down_up

[Henning Glawe]

Package: wpasupplicant
Version: 0.5.5-3
Severity: normal
Tags: patch

I have configured a roaming wpa configuration on my laptop using

allow-hotplug wlan0
iface wlan0 inet manual
        wpa-driver wext
		wpa-roam /etc/wpa_supplicant.conf

in /etc/network/interfaces.

If a disconnect event occurs, wpa_action is called with the action
DISCONNECTED, which "ifdown"s the interface and then should immediately
re-enable the scanning mode by calling 
/etc/wpa_supplicant/functions.sh::if_post_down_up

the problem is, at least in my case, that the link is _down_ afterwards,
so wpasupplicant is not able to scan further. This seems to be caused by
the interface not being completely downed yet when ifdown finishes;
putting a 'sleep 1' into functions.sh::ifdown immediately after the call
to /sbin/ifdown "solves" this problem.

Furter system configuration info:
- madwifi-ng wlan, using wpa_supplicants 'wext' driver
- dhcpcd dhcp client


-- System Information:
Debian Release: 4.0
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-3-686
Locale: LANG=C, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)

Versions of packages wpasupplicant depends on:
ii  libc6                        2.3.6.ds1-9 GNU C Library: Shared libraries
ii  libdbus-1-3                  1.0.1-2     simple interprocess messaging syst
ii  libncurses5                  5.5-5       Shared libraries for terminal hand
ii  libreadline5                 5.2-1       GNU readline and history libraries
ii  libssl0.9.8                  0.9.8c-4    SSL shared libraries
ii  lsb-base                     3.1-22      Linux Standard Base 3.1 init scrip

Versions of packages wpasupplicant recommends:
pn  dhcp3-client                  <none>     (no description available)

-- no debconf information