Also, if flow for ARP or ICMP etc messages are set then does it mean for
TCP/UDP another flow will be set or can the flow set by the ARP/ICMP work
for TCP/UDP packet?
On Mon, Nov 29, 2010 at 2:16 AM, K Singh <kavites...@gmail.com> wrote:
> I would like to have the default behavior of the pyswitch for those
> packets. I just want to filter out TCP/UDP packets and change flows based on
> it? Are you suggesting that I only run the custom function after detecting
> the TCP/UDP packet and for other packets let the flow get installed?
>
>
> On Mon, Nov 29, 2010 at 12:32 AM, kk yap <yap...@stanford.edu> wrote:
>
>> Simple question, what do you do for packet without UDP/TCP port? Like
>> ICMP, ARP, etc? That logic seems missing.
>>
>> Regards
>> KK
>>
>> On 28 November 2010 16:22, K Singh <kavites...@gmail.com> wrote:
>> > Hi,
>> >
>> > I modified the code below for function def forward_l2_packet(...) in
>> > pyswitch.py.
>> >
>> > def forward_l2_packet(dpid, inport, packet, buf, bufid):
>> >
>> > dstaddr = packet.dst.tostring()
>> > if not ord(dstaddr[0]) & 1 and inst.st[dpid].has_key(dstaddr):
>> > prt = inst.st[dpid][dstaddr]
>> > if prt[0] == inport:
>> > log.err('**warning** learned port = inport',
>> system="pyswitch")
>> > inst.send_openflow(dpid, bufid, buf, openflow.OFPP_FLOOD,
>> > inport)
>> > else:
>> > # We know the outport, set up a flow
>> > log.msg('installing flow for ' + str(packet),
>> system="pyswitch")
>> > flow = extract_flow(packet)
>> > flow[core.IN_PORT] = inport
>> > actions = [[openflow.OFPAT_OUTPUT, [0, prt[0]]]]
>> > # openflow.OFP_FLOW_PERMANENT
>> > renewflag = flowpacketdecision(dpid, flow, packet, inport,
>> buf)
>> > print "renewflag",renewflag
>> > #print packet
>> > if renewflag == 1:
>> > inst.install_datapath_flow(dpid, flow, CACHE_TIMEOUT,5,
>> > actions,bufid, openflow.OFP_DEFAULT_PRIORITY,inport, buf)
>> >
>> > else:
>> > # haven't learned destination MAC. Flood
>> > inst.send_openflow(dpid, bufid, buf, openflow.OFPP_FLOOD,
>> inport)
>> >
>> >
>> > The red highlighted part is where i made changes. I am making decision
>> on
>> > setting flow based on port numbers whose logic is in
>> > flowpacketdecision(...). If the function returns 1 i renew or set the
>> flow
>> > else i reject the packet and wait for another packet to come.
>> >
>> > But this logic, fails for ARP packet. Because in my
>> flowpacketdecision(..) i
>> > am checking for TCP/UDP packet and renewing/setting the flow. If i
>> receive
>> > ARP packet then in the current code it is not renewing/setting the flow.
>> > This means i cant proceed with TCP/UDP code anyways connection timeout
>> when
>> > tested in iperf.
>> >
>> > If i check for ARP packets and set the reneweflag = 1 then anyways the
>> flow
>> > is getting set irrespective of my logic. I even tried commenting the
>> > timer_callback function which removes the MAC entries so that ARP
>> message
>> > are not sent again after initially learning about MAC addresses. It
>> didnt
>> > work. Is there anyway I can block the ARP messages once transmitted and
>> then
>> > only have TCP/UDP messages flowing in the network.
>> >
>> > --
>> > Regards,
>> > Kavitesh Singh.
>> >
>> >
>> > _______________________________________________
>> > nox-dev mailing list
>> > nox-dev@noxrepo.org
>> > http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org
>> >
>> >
>>
>
>
>
> --
> Regards,
> K Singh.
>
>
--
Regards,
K Singh.
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