On 2/28/2025 6:20 PM, Johannes Berg wrote:
On Thu, 2025-01-23 at 06:39 +0530, Nithyanantham Paramasivam wrote:
Currently, in NO_VIRTUAL_MONITOR mode, when creating an
AP/STA + monitor, there is a restriction: if the AP/STA is running,
setting the channel for the monitor is not allowed. For example,
in a scenario with three supported radios where the AP uses only the
2 GHz and 5 GHz bands, the 6 GHz band remains available. However,
due to the restriction that rdev->num_running_ifaces must equal
rdev->num_running_monitor_ifaces in cfg80211_has_monitors_only(),
we are unable to create the monitor interface.
cfg80211_set_monitor_channel -> cfg80211_has_monitors_only()
static inline bool cfg80211_has_monitors_only() {
...
return rdev->num_running_ifaces == rdev->num_running_monitor_ifaces
&& rdev->num_running_ifaces > 0;
}
To address this, add the new wiphy flag
WIPHY_FLAG_SUPPORTS_NO_VIRTUAL_MONITOR to advertise no virtual monitor
support to cfg80211. This flag will allow the creation of a monitor
interface by bypassing the cfg80211_has_monitors_only() function.
I think it would make sense to call this differently in cfg80211, per
what it actually _achieves_, rather than per the *mac80211* logic about
it...
Sure. Perhaps I'll rename it to "WIPHY_FLAG_AP_MONITOR_SUPPORT"
There is no need for special handling after this, as
cfg80211_set_monitor_channel() will manage all interface combinations
and allowed radio conditions.
This sentence just can't be right - you're changing
cfg80211_set_monitor_channel() and there's no more code after it?
Sure. It's better if i remove this sentence.
johannes
Thank you for reviewing the code!
Nithi
