Hi Ben:
Got it ! So should we change the ofproto/trace cmd parameter from "dpname +
odp_flow + packet" to "dpname + origin packet" or "dpname + in_port +origin
packet" for convenience ?
Timo
------------------------------------------------------------------
Ben Pfaff <b...@ovn.org>
txfh2007 <txfh2...@aliyun.com>
Aaron Conole <acon...@redhat.com>; dev <d...@openvswitch.org>
Re: [ovs-dev] Re：Question about ovs-tcpundump
The packet is not needed for most purposes (a few exceptions are in the
documentation), but if you supply it you don't have to specify all of
the field values by hand.
On Wed, Jul 24, 2019 at 09:57:31AM +0800, txfh2007 via dev wrote:
> Hi Aaron:
> Perfect Answer! Thanks very much !!
> I have another question: how could the result of ovs-tcpundump get used
> in ofproto/trace ? From the document ovs-vswitchd I have found the
> ofproto/trace command shoud be formatted as "dpname + odp_flow + packet", but
> it seems the dpname + odp_flow is enough. The original packet from
> ovs-tcpundump is necessary?
>
>
> Timo
>
>
>
> ------------------------------------------------------------------
> Aaron Conole <acon...@redhat.com>
> 2019年7月23日(星期二) 22:06
> txfh2007 <txfh2...@aliyun.com>
> dev <d...@openvswitch.org>
> Re: Question about ovs-tcpundump
>
>
> "txfh2007" <txfh2...@aliyun.com> writes:
>
> > Hi Aaron:
>
> Hi Timo,
>
> > Sorry to bother, I have found your patch about
> > ovs-tcpundump(https://patchwork.ozlabs.org/patch/860190/), but I don't know
> > how to use this script. From the ovs-tcpundump -help I know this command
> > need a file as its arg（am i right?）, but I don't know which file type could
> > be use, the .pcap file?
> > Could you please explain the usage of the ovs-tcpundump script ?
>
> Glad to help. I've CC'd the ovs-dev list, also. First, from the manpage:
>
> The ovs-tcpundump program reads 'tcpdump -xx' output on stdin, looking
> for hexadecimal packet data, and dumps each Ethernet as a single
> hexadecimal string on stdout. This format is suitable for use with the
> 'ofproto/trace' command supported by ovs-vswitchd(8) via ovs-appctl(8).
>
> So the purpose of the program is to take output from tcpdump (or
> ovs-tcpdump - maybe it would be a good idea to update that manpage?) and
> convert it into something that can be passed to ofproto/trace. I think
> it could also be used as a way to generate data to pass to the
> 'packet-out' utility of the 'ovs-ofctl(8)' command.
>
> The 'file' appearing in the command synopsis section of the manpage
> might be misleading. It isn't an argument. I read it as indicating
> that the 'ovs-tcpundump' utility takes input via stdin and that input
> should be formatted in the same manner as 'tcpdump -xx' appears (so not
> a pcap, but the actual text output).
>
> ex:
>
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on enp0s31f6, link-type EN10MB (Ethernet), capture size 262144 bytes
> 09:59:08.246074 ARP, Request who-has 10.18.25.205 tell _gateway, length 46
> 0x0000: ffff ffff ffff 54e0 3230 be81 0806 0001
> 0x0010: 0800 0604 0001 54e0 3230 be81 0a12 19fe
> 0x0020: 0000 0000 0000 0a12 19cd 0000 0000 0000
> 0x0030: 0000 0000 0000 0000 0000 0000
>
> I take that and pipe it into ovs-tcpundump:
>
> 10:01:36 aconole@dhcp-25 {ct_error} ~/git/ovs/tests$
> ../utilities/ovs-tcpundump < /tmp/foo.txt
>
> ffffffffffff54e03230be810806000108000604000154e03230be810a1219fe0000000000000a1219cd000000000000000000000000000000000000
>
> If you have a pcap, it's possible to use tcpdump like:
>
> tcpdump -r some.pcap -xx | ./utilities/ovs-tcpundump
>
> Did I answer the question?
>
> > Thanks !
> >
> > Timo
>
> _______________________________________________
> dev mailing list
> d...@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
