Re: Interop problem with Quantum Fiber WiFi7 pods (duplicate RSNXE IE)

[Denis Kenzior <denkenz@gmail.com>]

Hi Vivek,

On 10/2/24 12:08 PM, Vivek Das Mohapatra wrote:
> Hi - we've had reports of an incompatibility between network manager and
> the wifi7 hardware mentioned when using iwd as the backend.
> 
>  From what we've been able to tell:
> 
> validate_mgmt_ies() fails
> cause: disallowed duplicate IEs in the AssocResponse frame
> 
> We appear to have two dupes:
> 
> 221 - IE_TYPE_VENDOR_SPECIFIC - allowed
> 244 - IE_TYPE_RSNX - not allowed as a dup.
> 
> We checked IEEE 80211-2020.pdf couldn't find specific details about IEs
> that can be duplicated vs the ones that can’t.
> [ Sections 9.4.2.1 and 9.4.2.241 ]

Refer to section 9.3.3.1:
"The frame body consists of fields and elements as defined for each management 
frame subtype. All fields and elements are mandatory unless stated otherwise. 
Fields and elements appear in the specified, relative order, skipping fields or 
elements that are not present. STAs that encounter an element ID they do not 
recognize in the frame body of a received Management frame ignore that element 
and continue to parse the remainder of the management frame body (if any) for 
additional elements with recognizable element IDs."

IEs that allow duplication are explicitly called out:
"Vendor Specific
One or more Vendor Specific elements are optionally present. These elements 
follow all other elements."

Why are the elements duplicated?  Are they the same or different?  If different, 
which one would iwd use?

> 
> We've tried various devices and software combinations (linux and non)
> and it seems to be an interop problem with iwd specifically - we think adding 
> IE_TYPE_RSNX to the allowed dups list in validate_mgmt_ies should
> do the trick.

How about fixing the firmware?

Regards,
-Denis