kern/165517: [net80211] bgscan isn't triggered when invalid beacons are being sent

[Adrian Chadd]

>Number:         165517
>Category:       kern
>Synopsis:       [net80211] bgscan isn't triggered when invalid beacons are being sent
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 28 02:40:07 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Adrian Chadd
>Release:        -CURRENT
>Organization:
>Environment:
9.0-RELEASE with HEAD net80211/ath
>Description:
I was trying to figure out why bgscan isn't working in some instances.

What's happening is this:

* the bgscan is triggered via sta_recv_mgmt(), on a valid beacon frame
* but if the beacon frame isn't valid, it fails an earlier check, so the ieee80211_bg_scan() call is never made.

>How-To-Repeat:
Find an AP whose beacons fail the check.
>Fix:
* Fix ieee80211_parse_beacon() if it needs to be fixed
* potentially ignore the beacon contents _but_ still trigger a background scan if possible.


>Release-Note:
>Audit-Trail:
>Unformatted: