[Patch v3] supplicant: add dbus getter method for nl80211 iftype

[Johannes Berg]

On Mon, 2014-12-22 at 15:11 +0530, Avinash Patil wrote:


> Implementations may vary from vendor to vendor. One vendor implements
> it this way does not mean all should follow the same, isnt it?
> Interface capabilities/combination advertised by wiphy are per
> hardware device and there is no restriction on how these this
> combination can be supported. Single hardware device can be emulated
> to support multiple virtual interfaces with different capabilities and
> that's what we intend to do.
> 
> So when wiphy capabilities indicate support for AP interface, it does
> not mean we should expect very first interface to be of AP type.
> Driver can have multiple virtual interfaces and one of them would
> support AP operation. So having right to know interface type is
> something that is not expected??

I disagree. The API makes no representation about interface order or
interface to type assignment, neither in the documention nor in the code
that checks the validity of adding a given interface. As a consequence,
users of the API need not expect such restrictions.

Similarly, before multi-interface was even supported, drivers would just
advertise the interface types they support and of course userspace had
to be able to switch a given interface's type.

> Our current implementation cannot modify interface type(AP<=>STA) but
> still we are able to support simultaneous AP/STA operations using
> hostapd/wpa_supplicant.

Then I would argue that this is a bug in your implementation.

> Connman expects to control both using wpa_supplicant and this is where
> we need to have support from supplicant to know interface type.

The connman people seem to be missing from this discussion, but I doubt
they really want to have to deal with such restrictions?

> Also about notification handlers, if you are not OK with it, I would
> completely remove notification handler related code.

I have no idea, I wasn't really commenting much on the code itself.

johannes