[0.6.x PATCH] SIGUSR1 changes debug level

[Jouni Malinen]

On Thu, Dec 06, 2007 at 04:45:17PM -0500, Dan Williams wrote:

> So you don't have to respawn wpa_supplicant with different debug
> options, or fire up a control interface or something.  Many *NIX
> programs have this functionality; bring it to wpa_supplicant too.

The functionality itself sounds fine, but use of SIGUSR1 in
wpa_supplicant.c is not portable and that file needs to build for all
targets. Furthermore, hostapd is already using SIGUSR1 for something
else (state dump into a file) which would make this somewhat conflicting
use of signals between hostapd and wpa_supplicant.

> --- a/wpa_supplicant/wpa_supplicant.c

> @@ -1918,6 +1934,8 @@ int wpa_supplicant_run(struct wpa_global *global)
>  	eloop_register_signal_terminate(wpa_supplicant_terminate, NULL);
>  	eloop_register_signal_reconfig(wpa_supplicant_reconfig, NULL);
>  
> +	eloop_register_signal(SIGUSR1, wpa_supplicant_handle_sigusr1, NULL);

I added those eloop_register_signal_{terminate,reconfig}() functions to
hide the signal (etc.) details into platform specific code (eloop*.c).
Something similar would be needed for SIGUSR1. Though, I would rather
not change eloop interface for 0.5.x, so this may end up only in 0.6.x
branch.

Another option would be to use ctrl_iface to change the debug level.
That would have the extra benefit of being able to take in the exact
debug level instead of just switching to another level. This sounds more
useful to me since the caller would know what the end result is
regardless of the current state. With just SIGUSR1 available, the caller
would not really be able to tell whether the next signal will enable or
disable debugging (or just change the level of already enabled
debugging).

-- 
Jouni Malinen                                            PGP id EFC895FA