Hello --
I want to *install and modify* flow entries* from the controller*. First, I
proactively install new rules into the flow table in this way:
*#flow generate-- simulated flows*
for i in "a set of ip addresses":
u = udp()
u.srcport = 1
u.dstport = 2
p = ipv4()
p.set_payload(u)
p.srcip =IPAddr(i)#i is increased ip address such as 192.168.0.1,
192.168.0.2, 192.168.0.3, ... 192.168.1.255 ...
p.dstip = IPAddr("192.168.56.100")
e =ethernet (...)
e.set_payload(p)
*#get a match from packet and tries to install a new rule...*
msg = of.ofp_flow_mod()
msg.match = of.ofp_match.from_packet(packet, event.port)
msg.idle_timeout = 10
msg.hard_timeout = 30
msg.actions.append(of.ofp_action_output(port = port))
self.connection.send(msg)
Till now, the results is what I expected-- a set of new rules are installed
in the flow table;
Next, I want to *modify* the installed (newly installed rules). At the
same time, I want to *send out a packet which matches a particular
rules*so that I know that modified rule takes effect.
The code is like this--
*#repeat the "**flow generate-- simulated flows" procedure
...
#*
*#get a match from packet and tries to modify that rule...
*
msg = of.ofp_flow_mod()
msg.command = of.OFPFC_MODIFY (make sure that this command is for
modification)
msg.match = of.ofp_match.from_packet(packet, event.port)
msg.idle_timeout = 10
msg.hard_timeout = 30
msg.data = e.pack()
msg.actions.append(of.ofp_action_output(port = port))
self.connection.send(msg)
Now, I get the error:
********error message*****************
File "/home/sdn/pox/pox/openflow/of_01.py", line 687, in send
data = data.pack()
File "/home/sdn/pox/pox/openflow/libopenflow_01.py", line 2191, in pack
self.buffer_id = self.data.buffer_id
*********error message end**********
I tested that If I change msg = of.ofp_flow_mod() to msg =
of.ofp_packet_out(), it is fine. But I do not just want to send packet out.
What I want to do is, first modify a rule and then send out a packet
matching that rule.
Can anyone help on the error? Thanks:)
AttributeError: 'str' object has no attribute 'buffer_id'
