>Number:         156743
>Category:       kern
>Synopsis:       [lagg] [patch] if_lagg should not treat vlan-tagged frames as 
>LACP frames
>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:   Sat Apr 30 19:20:11 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Dmitrij Tejblum
>Release:        8.2-STABLE
>Organization:
OOO Yandex
>Environment:
>Description:
When if_lagg check if an input frame is a LACP (slow protocol) frame,  it can 
treat VLAN-tagged LACP frames as LACP frames, since the NIC could have removed 
the VLAN tag. Since LACP frames must not be send VLAN-tagged, if_lagg should 
check for that.

(Some broken switches sometimes incorrectly forward LACP frames to other ports, 
rather than handle them as LACP. It can result in VLAN-tagged LACP frames. If 
if_lagg receive such a forwarded LACP packet, it becomes confused. This patch 
provide some protection against this misbehaviour.)
>How-To-Repeat:

>Fix:


Patch attached with submission follows:

--- sys/net/if_lagg.c.00        2011-02-25 14:05:35.000000000 +0300
+++ sys/net/if_lagg.c   2011-04-28 15:24:00.000000000 +0400
@@ -1831,11 +1831,11 @@ lagg_lacp_input(struct lagg_softc *sc, s
 
        eh = mtod(m, struct ether_header *);
        etype = ntohs(eh->ether_type);
 
        /* Tap off LACP control messages */
-       if (etype == ETHERTYPE_SLOW) {
+       if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_SLOW) {
                m = lacp_input(lp, m);
                if (m == NULL)
                        return (NULL);
        }
 


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