[PATCH] Add an option to set secondary channel in hostapd conf

[Aaron Komisar]

On Fri, 26 Feb 2021 23:16:20 +0200, Jouni Malinen wrote:
> > Usefull in case we want to specify the secondary channel
> > or in case we want to be on 20mghz with 40mghz capabilities.
> > 
> > It is possible in chan_switch to set secondary channel,
> > however it was not possible to do so when hostapd start.
> > This commit adds this option.
> 
> Can you please clarify how this proposed new parameter differs from the
> existing ht_capab=[HT40+], ht_capab=[HT40-], and ht_capab=[HT40+][HT40-]
> options?
> 

The existing parameter enables setting capabilities but not the actual current
operating channel configuration.

> Please also note that the IEEE 802.11 standard has mandatory
> requirements for 40 MHz co-existence on when the primary and secondary
> channels have to be switched and I'm unlikely to accept changes
> that would allow the user to bypass those requirements.
> 

The purpose of the patch is to provide capabilities similar to chan_swich
command, which already supports setting secondary channel dynamically.

A similar commit has already been integrated to prplMESH project in order to
support cancel CAC command by disabling interfaces, setting a specific channel
and enabling the interfaces.
(https://gitlab.com/prpl-foundation/intel/iwlwav-hostap/-/merge_requests/5) 
Currently a 20Mhz channel cannot be set.

-- 
Aaron Komisar