[ovs-discuss] ovs-ofctl doesn't talk proper OF 1.2

Ben Pfaff blp at nicira.com
Wed Sep 11 16:32:00 UTC 2013


On Wed, Sep 11, 2013 at 03:51:51PM +0200, Torbjorn Tornkvist wrote:
> I'm implementing the OF 1.2 protocol and was trying to set an
> ipv4-src address in an action.
> It seems however that OVS (1.11) dosn't talk proper OF 1.2.

OpenFlow 1.1 and later support is experimental.  Thanks for trying it
out and reporting a problem.

> Have a look at two wireshark sessions at:
> 
>   http://picpaste.com/pics/of-1.2-CqqrPKPw.1378906446.png

That picture is almost unreadably fuzzy because it is an 1852 x 1113
image scaled down to 640 x 384.  If you post screenshots, please make
sure them readable.

> The left window is me talking 1.2 and the right window is the result
> of this command:
>
>   ovs-ofctl  --protocol=OpenFlow12 add-flow 'tcp:192.168.1.120:6633
> lsw' 'in_port=1,dl_src=86:d7:3c:a1:bb:d5,dl_type=0x8000
> actions=mod_nw_src:192.168.111.111'

"lsw"?

> Look at the Action Type!

I'm looking at it.  It looks like a bunch of fuzz.  It *might* say 00 10
on the left and 00 05 on the right.  Oh, I guess that "set-field" is 25
so that must be 00 19 on the left.

> Is it a bug? Is it intentional? or what?

OpenFlow 1.1 uses action 5 to mean OFPAT_SET_NW_SRC.

OpenFlow 1.2 action numbering is backward-compatible with OpenFlow 1.1,
so presumably it means that same thing in OpenFlow 1.2.

I guess the point you're trying to make is that OVS should translate
mod_nw_src into set_field for OF1.2?  That's reasonable; I'll make a
note.

> Btw: when I send the proper 1.2 message, I get the following in the
> daemon.log:
> 
>    ovs-vswitchd: ovs|11535|meta_flow|WARN|destination field ip_src
> lacks correct prerequisites

Based on the command you provided above, this is probably because you
think that 0x8000 is the ethernet type for IPv4.  It's not.

> Any ideas on how to perform some interop. testing of the various OF
> proto versions?

I don't know a good way, but this is already some useful feedback.
Thanks.



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