Re: tc match MAC destination - nothing matches on protocol 802_3

From: Doru Petrescu
Date: Thu Jun 16 2011 - 16:31:36 EST


On Thu, 2011-06-16 at 08:51 -0700, Stephen Hemminger wrote:
> On Thu, 16 Jun 2011 10:56:52 +0300
> Doru Theodor Petrescu <pdoru.kernel@xxxxxxx> wrote:
>
> >
> >
> > I updated my scripts to use the 'tc filter ... match ether src/dst'
> > syntax. it really makes reading the script easier. thanks for the tip!
> >
> > however the problem persists. I changed the rule to match ANY pachet of
> > type 802_3 and redirect it to ifb1. but nothing arrives on ifb1.
> >
> > I tried to redirect ARP pachets using 'protocol arp' filter and it works
> > perfectly as expected.
> >
> > so at this point the problem is no longer 'how to match ethernet header'
> > but rather 'how to match a pachet of type 802_3'. My feeling is that
> > there is a bug somewhere in kernel where the 'protocol 802_3' matching
> > happens.
> >
> >
> > I attach part of the script I use to generate the filters and classes. I
> > removed everything related to HTB and IP pachets because there is no
> > problem there. in case the formating is lost, you can download it from
> > here: http://evox.ro/kernel_netdev_tc_protocol_802.3/
> >
> >
> > Thx for any help,
> > Doru Theodor Petrescu
> > CTO, Evox Solutions SRL
> > http://evox.ro/
> >
> >
> >
> > for DEV in bond0.2199 bond1.2199 bond0.3000 bond1.3001 ; do
> >
> >
> > tc qdisc del dev $DEV root
> >
> > tc qdisc add dev $DEV root handle 1: htb default 2
> > tc class add dev $DEV parent 1: classid 1:1 htb rate 930000kbit ceil
> > 930000kbit quantum 1600
> >
> > tc filter add dev $DEV parent 1: prio 5 protocol ip u32
> > # ==> 800:
> >
> > tc filter add dev $DEV parent 1: prio 1 protocol 0x0806 u32
> > # ==> 801: protocol ARP
> > tc filter add dev $DEV parent 1: prio 1 handle 801:0:7 protocol
> > 0x0806 u32 match u32 0 0 flowid 1:3
> >
> > tc filter add dev $DEV parent 1: prio 2 protocol 802_3 u32
> > # ==> 802:
> >
> > tc filter add dev $DEV parent 1: prio 6 protocol ip u32
> > # ==> 803:
> >
> >
> > tc filter replace dev $DEV parent 1: prio 2 handle 802:0:3 protocol
> > 802_3 u32 match u16 0 0 at 0 flowid 1:3 action mirred egress mirror dev
> > ifb1
> > tc filter replace dev $DEV parent 1: prio 2 handle 802:0:9 protocol
> > 802_3 u32 match ether src 01:00:0c:cc:cc:cd flowid 1:3 action mirred
> > egress mirror dev ifb1
> > tc filter replace dev $DEV parent 1: prio 2 handle 802:0:10 protocol
> > 802_3 u32 match ether dst 01:00:0c:cc:cc:cd flowid 1:3 action mirred
> > egress mirror dev ifb1
> >
> > done
> >
> >
> > # the 802_3 pachet filter:
> > #
> > # 802:0:3 should match ANY pachet of type 802_3 and mirror it to ifb1
> > # 802:0:9 and 802:0:10 should match any pachet with src/dst
> > 01:00:0c:cc:cc:cd and mirror it to ifb1
> > #
> > # however NOTHING is going to ifb1 try 'tcpdump -nltve -i ifb1'
> > # at the same time 'tcpdump -nltve -i bond1.2199 ether host
> > 0100.0ccc.cccd' will show about one pachet every second
> > #
> >
> >
> > # at the same time the ARP filter works. you can mirror all ARP trafic
> > to IFB1 like this:
> > # tc filter replace dev $DEV parent 1: prio 1 handle 801:0:7 protocol
> > 0x0806 u32 match u32 0 0 flowid 1:3 action mirred egress mirror dev
> > ifb1
>
> I think you want 802_2 to match STP frames. 802_3 is a dummy value
> for the old Novell IPX encapsulation




well, this is what TCPDUMP will print:
00:1d:45:d7:19:7a > 01:00:0c:cc:cc:cd, 802.3, length 64: LLC, dsap SNAP
(0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Cisco
(0x00000c), pid Unknown (0x010b): Unnumbered, ui, Flags [Command],
length 50


it thinks it's 802.3 so this is why I used 802_3


I just tried your advice and created a filter with protocol 802_2 and
guess what ... IT WORKS !!!


so, don't use 'protocol 802.3' use 'protocol 802.2' in tc filters!

thanks everybody!
D.




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