Date: Sat, 30 Apr 2011 19:12:37 GMT From: Dmitrij Tejblum <tejblum@yandex-team.ru> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/156743: [lagg] [patch] if_lagg should not treat vlan-tagged frames as LACP frames Message-ID: <201104301912.p3UJCbpX083631@red.freebsd.org> Resent-Message-ID: <201104301920.p3UJKB9b025809@freefall.freebsd.org>
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>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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