Hi,
I tested the code and view the packets in Wireshark. For ETH packets, it
works. For IPV4, some errors when I complie it.
(1) I tried ETH packets and the host can receive the packets.
eth_packet= ethernet()
eth_packet.set_payload(str("hello"))
eth_packet.dst = packet.dst
eth_packet.src = packet.src
eth_packet.type = ethenet.IP_TYPE
self.send_openflow_packet(dpid,eth_packet.tostring(),inport)
(2) I tried IPV4 and this time an error " "H" format requires
<=number<=65535 " , here's the following code
ipv4_packet = ipv4()
payload = str("hello")
ipv4_packet.iplen = ipv4.MIN_LEN + len(payload)
ipv4_packet.set_payload(payload)
ipv4_packet.dstip = str("10.0.0.3")
ipv4_packet.srcip = str("192.168.56.102")
eth_packet= ethernet()
eth_packet.set_payload(ipv4_packet)
packet.dst = packet.dst
eth_packet.src = packet.src
eth_packet.type = ethenet.IP_TYPE
ipv4_packet.csum = ipv4_packet.checksum()
self.send_openflow_packet(dpid,ipv4_packet.tostring(),inport)
I guess why it is failed maybe due to such line ipv4_packet.dstip
= str("10.0.0.3") is not acceptable. Or other reasons?
Thanks very much.
Weiyang
2012/4/25 Aaron Rosen <[email protected]>
> Hi Weiyang,
>
> You can inject packets from the controller into the switch like this.
> Here is some code that I've used to send UDP packets from the
> controller to hosts.
>
> Aaron
>
> def send_udp(mac, dstip, srcip, port, payload):
> l4 = udp()
> l4.srcport = port
> l4.dstport = AGENT_MESSAGE_PORT
> l4.len = udp.MIN_LEN + len(payload)
> l4.set_payload(payload)
> l4.arr = l4.tostring()
> l3 = ipv4()
> l3.iplen = ipv4.MIN_LEN + l4.len
> l3.protocol = ipv4.UDP_PROTOCOL
> l3.dstip = dstip
> l3.srcip = srcip
> l3.set_payload(l4)
> l2 = ethernet()
> l2.set_payload(l3)
> l2.dst = mac
> l2.src = octstr_to_array(CONTROLLER_MAC)
> l2.type = ethernet.IP_TYPE
> l4.csum = l4.checksum()
> return l2
>
>
> inform_dest = send_udp(mac, dstip, srcip, port, payload)
> inst.send_openflow_packet(HA, inform_dest.tostring(),
> inst.Agent[HA]['inport'], openflow.OFPP_NONE)
>
>
> On Wed, Apr 25, 2012 at 3:02 PM, Weiyang Mo <[email protected]>
> wrote:
> > Thanks very much for your quick reply.
> >
> > But I am still confused. do you mean that "the controller instruct a
> switch
> > to send a packet" is not an OpenFlow feature? Or I misunderstand what you
> > mean.
> >
> > I am sending packets from a client to a server through multiple OpenFlow
> > switches. I already have this functionality that the controller inserts
> > flow-entries and then the packets can be sent to the server.
> >
> > Now, I want to have another action that " when the controller receives
> the
> > first packet-in message, it can instruct a switch to send a packet which
> > contains some data(e.g, hello). And this new packet can be sent to
> another
> > host. If so, the host can run other applications automatically upon
> receving
> > the packet "hello".
> >
> > Is it possible?( Packet in->controller controller-> instrucrt the
> > switch to create a new packet new packet(Hello) ->host). How should I
> > write the pseudo code.
> >
> > Thanks
> >
> > Weiyang
> >
> > 2012/4/25 Murphy McCauley <[email protected]>
> >>
> >> There are no examples of this because this is not an OpenFlow feature --
> >> only the controller can instruct a switch to send a packet.
> >>
> >> Unless maybe there is some vendor extension for some switches…
> >>
> >> -- Murphy
> >>
> >> On Apr 25, 2012, at 11:28 AM, Weiyang Mo wrote:
> >>
> >> BTW,any example code for this? For instance, the controller wishes to
> send
> >> a packet which contains the data "Hello" through the switch to the
> Output.
> >>
> >> How should I write the code? Is it like
> "actions=[openflow.ofp_packet_out,
> >> ...]" ?
> >>
> >> I am not clear because I don't find sample codes. Could anyone
> provides a
> >> simple sample code?
> >>
> >> Regards
> >>
> >> Weiyang
> >> ---------- Forwarded message ----------
> >> From: Weiyang Mo <[email protected]>
> >> Date: 2012/4/25
> >> Subject: instruct the swtich to create a new packet.
> >> To: [email protected]
> >>
> >>
> >> Hi,all,
> >>
> >> I want to insert an action in to flow entry. The action can tell the
> >> switch to create a new arbitary packet. What command should I use?
> >>
> >> Thanks a lot
> >>
> >> Weiyang
> >>
> >>
> >
>
>
>
> --
> Aaron O. Rosen
> Masters Student - Network Communication
> 306B Fluor Daniel
>
