kern/72933: promisc mode on vlan interface does not work correctly

[Lenar D. Tukhvatullin]

>Number:         72933
>Category:       kern
>Synopsis:       promisc mode on vlan interface does not work correctly
>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:   Wed Oct 20 17:40:14 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Lenar D. Tukhvatullin
>Release:        5.3-STABLE
>Organization:
Ulyanovsk State Technical University
>Environment:
FreeBSD xxx.com 5.3-STABLE FreeBSD 5.3-STABLE #2: Wed Oct 20 12:22:08 MSD 2004     lenar at xxx.com:/usr/obj/usr/src/sys/GENERIC  i386

FreeBSD 5.3-STABLE, RELENG_5 cvsup'ed at Oct 20 2004
>Description:
Promiscuous mode on vlan interface does not work if parent interface
supports VLAN_HWTAGGING. Probably bug in sys/net/if_ethersubr.c:650
(packet with non-parents ethernet-address is rejected by ether_demux)
>How-To-Repeat:
(bge0 supports VLAN_HW_TAGGING)

# ifconfig vlan0 create
# infconfig vlan0 vlan 1 vlandev bge0
# ifconfig bge0 up
# ifconfig vlan0 up

configure bridging beetwen vlan0 and another interface (bge1):

# ifconfig bge1 172.16.0.1 netmask 255.255.255.0
# kldload bridge
# sysctl.net.link.ether.bridge.config="vlan0 bge1"
# sysctl.net.link.ether.bridge.enable=1

log messages:
.. kernel: bge1: promiscuous mode enabled
.. kernel: bge0: promiscuous mode enabled
.. kernel: vlan0: promiscuous mode enabled

pinging host (172.16.0.2 located on bge0 side in vlan 1)

# ping 172.16.0.2
..
Host is down
Host is down

-----

tcpdump's in another console:

# tcpdump -e -i bge0

21:20:24.753738 00:08:02:91:d5:61 > Broadcast, ethertype ARP (0x0806), length 42: arp who-has 172.16
.0.2 tell 172.16.0.1

21:20:24.755528 00:11:20:11:34:c0 > 00:08:02:91:d5:61, ethertype ARP (0x0806), length 60: arp reply
172.16.0.2 is-at 00:11:20:11:34:c0

21:20:25.758096 00:08:02:91:d5:61 > Broadcast, ethertype ARP (0x0806), length 42: arp who-has 172.16
.0.2 tell 172.16.0.1

21:20:25.759672 00:11:20:11:34:c0 > 00:08:02:91:d5:61, ethertype ARP (0x0806), length 60: arp reply
172.16.0.2 is-at 00:11:20:11:34:c0

...

# tcpdump -e -i vlan0

21:22:35.649629 00:08:02:91:d5:61 > Broadcast, ethertype ARP (0x0806), length 42: arp who-has 172.16
.0.2 tell 172.16.0.1

21:22:36.650105 00:08:02:91:d5:61 > Broadcast, ethertype ARP (0x0806), length 42: arp who-has 172.16
.0.2 tell 172.16.0.1

..

-----

incoming packet on bge0 is not delivered to vlan0 interface.
>Fix:
fix sys/net/if_ethersubr.c:650 (in function ether_demux)

original:

!(ether_type == ETHERTYPE_VLAN && ifp->if_nvlans > 0)) {

fixed:

!((ether_type == ETHERTYPE_VLAN || m_tag_locate(m, MTAG_VLAN, MTAG_VLAN_TAG, NULL) != NULL) && ifp->if_nvlans > 0)) {

this is an example, may be fixed by other way...

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