Your first call to install_datapath_flow() in the code below is wrong. The
last argument you're passing is priority. But the parameter at that position
is buffer_id. So what you're actually doing is telling the switch to use
buffer_id 5 over and over.
Either insert a "None" between actions and priority, or make the last argument
use a keyword argument ("priority=priority").
Hope that helps.
-- Murphy
On Dec 1, 2011, at 1:52 AM, Giorgio Mazza wrote:
> Hello,
> I have a problem in the communication between an OpenFlow switch (I use
> OpenVswitch) and my NOX controller, connected out-of-band.
> The two machines connects, but, after I install the first flow, I get the
> following error message:
> *openflow-event|ERR:received Openflow error packet from dpid=XXXXXX:
> type=1, code=7, 24 bytes of data*
>
> and the "*ovs-openflowd*" terminal showed following error
>
> *"attempt to reuse the buffer"*
>
> While discussing on ovs-discuss mailing list they suggest that "Send a given
> buffer_id only in a single OpenFlow request".
> I have also seen that there was a guy who wrote here an email as he had the
> same problem, so maybe you already solved this.
>
> In my controller I want to install flows after a miss in the flow table. Here
> is a part of the code.
>
> def packet_in_callback(self, dp_id, inport, ofp_reason,
> total_frame_len, buffer_id, packet):
> ethr_pkt = packet.find('ethernet')
>
> if (ofp_reason == openflow.OFPR_NO_MATCH) :
> print "!!!!!!!!!!!!!!!!!!! W A R N I N G
> !!!!!!!!!!!!!!!!!!!!"
> print "No matching rule in the flow table."
>
> if(ethr_pkt.type == ethernet.ARP_TYPE):
> m_arp = ethr_pkt.find('arp')
> src_ip = ip_to_str(m_arp.protosrc)
> dst_ip = ip_to_str(m_arp.protodst)
> print "Received an ARP packet with", "\n src_ip: ",
> src_ip, "dst_ip: ", dst_ip
> arp_type = m_arp.opcode
> if (arp_type == 1):
> print "This is an ARP REQUEST coming from port",
> inport
> elif (arp_type == 2):
> print "This is an ARP REPLY coming from port",
> inport
> attr = {}
> attr [core.IN_PORT] = inport
> attr [core.DL_TYPE] = ethr_pkt.type
> idle_timeout = openflow.OFP_FLOW_PERMANENT
> hard_timeout = openflow.OFP_FLOW_PERMANENT
> priority = 5
> if inport == 25:
> outport = 26
> elif inport == 26:
> outport = 25
> actions = [[openflow.OFPAT_OUTPUT, [0,outport]]]
> self.install_datapath_flow(dp_id,
> attr,
>
> idle_timeout,
>
> hard_timeout,
> actions,
> priority)
>
>
> elif(ethr_pkt.type == 0x0800):
> ip_pkt = packet.find('ipv4')
> src_ip = ip_to_str(ip_pkt.srcip)
> dst_ip = ip_to_str(ip_pkt.dstip)
> tos = ip_pkt.tos
> nw_proto = ip_pkt.protocol
>
> print "The incoming packet has the following
> structure: ", "\n L3 Protocol: ", nw_proto, "\n src_ip: ", src_ip
> print " dst_ip: ", dst_ip, "\n TOS: ", tos
>
>
> if (ip_pkt.protocol == 1):
> attrs = {}
> attrs[core.IN_PORT] = inport
> attrs[core.DL_TYPE] = ethr_pkt.type
> attrs[core.NW_SRC] = ip_pkt.srcip
> attrs[core.NW_DST] = ip_pkt.dstip
> attrs[core.NW_PROTO] = nw_proto
> attrs[core.NW_TOS] = tos
> idle_timeout = openflow.OFP_FLOW_PERMANENT
> hard_timeout = openflow.OFP_FLOW_PERMANENT
> if inport == 26:
> outport = 25
> elif inport == 25:
> outport = 26
> actions = [[openflow.OFPAT_OUTPUT, [0, outport]]]
> self.install_datapath_flow(dp_id,
> attrs,
>
> idle_timeout,
>
> hard_timeout,
>
> actions,
> None,
>
> openflow.OFP_DEFAULT_PRIORITY,
> inport,
> None)
>
>
>
> and so on with other if-else conditions.
> Do you have any ideas of what could be the cause of such a behaviour and how
> could I solve it?
>
> I also extended NOX source code a little in order to add a new L4 protocol
> for my work. Do you think this issue could be related to some mistakes I
> could have done?
>
>
> Thanks,
> Giorgio Mazza
> _______________________________________________
> nox-dev mailing list
> nox-dev@noxrepo.org
> http://noxrepo.org/mailman/listinfo/nox-dev
_______________________________________________
nox-dev mailing list
nox-dev@noxrepo.org
http://noxrepo.org/mailman/listinfo/nox-dev
