Re: [Bugme-new] [Bug 41152] New: kernel 3.0 and above fails to handle vlan id 0 (802.1p) packets properly without hardware acceleration

(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Sun, 14 Aug 2011 12:48:16 GMT
bugzilla-daemon@bugzilla.kernel.org wrote:

https://bugzilla.kernel.org/show_bug.cgi?id=41152

           Summary: kernel 3.0 and above fails to handle vlan id 0
                    (802.1p) packets properly without hardware
                    acceleration
           Product: Networking
           Version: 2.5
    Kernel Version: 3.0
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Other
        AssignedTo: acme@ghostprotocols.net
        ReportedBy: mike.auty@gmail.com
        Regression: Yes


Hi there,

I recently found that packets tagged with a vlan id of 0 are no longer received
on the main interface.  There were no dmesg entries on the dropped packets.  I
attempted to setup a vlan 0 interface and configure it, but couldn't
successfully route traffic to the device.  I can recreate this on two of the
three networking devices I have, my guess is that the third does successfully
handle hardware acceleration of vlan tags. 

After a bisection this appears to be related to commit
bcc6d47903612c3861201cc3a866fb604f26b8b2, which seems to try to merge the
non-hardware accelerated and hardware accelerated code paths for handling
vlans.  In the process, it appears vlan id 0 (802.1p) packets are no longer
handled correctly.

Unfortunately I don't know the code paths well enough to figure out what's
going wrong, but I'd be happy to provide more information, run tests or try out
patches if it would help, just let me know.  Thanks...  5:)

Mike  5:)