Re: [RFC] mac80211_hwsim: Adds parameter use_hwsim_mon which can be used to disable hwism0

[Johannes Berg <johannes@sipsolutions.net>]

On Fri, 2015-10-30 at 17:05 -0400, arwelle@cert.org wrote:
> From: Adam Welle <arwelle@cert.org>
> 
> A new parameter, use_hwsim_mon has been created to implement new 
> functionalilty. use_hwsim_mon defaults to true so that normal 
> operation remains the same. When set to false, the hwsim0 device is 
> not created. This value is also checked before calling functions 
> which would transmit data to the hwsim0 device.

I understand the use case (since you explained it to me off-list), but
I don't think I want to apply this since in almost all cases having
hwsim0 around but unused isn't actually harmful.

FWIW,

> -	mac80211_hwsim_monitor_rx(hw, skb, channel);
> +	if (use_hwsim_mon)
> +		mac80211_hwsim_monitor_rx(hw, skb, channel);

Had I wanted to apply this, I'd probably have insisted to move the
check into the function instead of outside of it, since that leaves no
chances of getting it wrong when changing the code in the future.

johannes