Hi Iwase Yusuke, thank you for your reply at my question.

I check your reply and its correct, but i don't understand one point:

Why the packet_in genereted from switch never stop to coming? And i make a 
ping, the controller install the flow (correctly) and in this method a new ping 
between hosts dont create a new packet_in. Something dosent work or i miss 
something?

Thank you for your time

Luca Spinazzè

________________________________
Da: Iwase Yusuke <[email protected]>
Inviato: mercoledì 30 novembre 2016 01.12.08
A: Spinazze' Luca
Cc: [email protected]
Oggetto: Re: [Ryu-devel] Some question about how manage packet_in

Hi.

Sorry for the delay.

On 2016年11月28日 16:45, Spinazze' Luca wrote:
> Thank you for your answer!
>
> I see these pages, but when i print the ipv4_src (if the packet have it) this 
> is ip of switch and not of host. This is correct, because the packet is 
> encapsulated with eth(ipv4/6(tcp/udp( packet_in()))). I need to read the ipv4 
> of host that generated the packet_in, not the switch that send it. Is it 
> possibile?

Well, that sounds strange...
If you analyze the packet data of the Packet-In messages (e.g., ev.msg.data),
the contained packets should be from hosts.

As you say, the destination of the Packet-In message is the controller,
OTOH, the Packet-In messages should contain the packets from hosts.

Here is a sample for parsing IPv4 packets extracted from the Packet-In messages.

$ git diff
diff --git a/ryu/app/simple_switch_13.py b/ryu/app/simple_switch_13.py
index 3e7c598..322ed3a 100644
--- a/ryu/app/simple_switch_13.py
+++ b/ryu/app/simple_switch_13.py
@@ -21,6 +21,7 @@ from ryu.ofproto import ofproto_v1_3
  from ryu.lib.packet import packet
  from ryu.lib.packet import ethernet
  from ryu.lib.packet import ether_types
+from ryu.lib.packet import ipv4


  class SimpleSwitch13(app_manager.RyuApp):
@@ -90,6 +91,11 @@ class SimpleSwitch13(app_manager.RyuApp):

          self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)

+        ipv4_pkt = pkt.get_protocol(ipv4.ipv4)
+        if ipv4_pkt:
+            self.logger.info("IPv4 packet: src=%s, dst=%s",
+                             ipv4_pkt.src, ipv4_pkt.dst)
+
          # learn a mac address to avoid FLOOD next time.
          self.mac_to_port[dpid][src] = in_port


$ sudo mn --controller remote
...
mininet> h1 ping -c 1 h2
PING 10.0.0.2 (10.0.0.2) 56(84) bytes of data.
64 bytes from 10.0.0.2: icmp_seq=1 ttl=64 time=5.71 ms

--- 10.0.0.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 5.717/5.717/5.717/0.000 ms
mininet>


$ ryu-manager ryu/app/simple_switch_13.py
loading app ryu/app/simple_switch_13.py
loading app ryu.controller.ofp_handler
instantiating app ryu/app/simple_switch_13.py of SimpleSwitch13
instantiating app ryu.controller.ofp_handler of OFPHandler
...
IPv4 packet: src=10.0.0.1, dst=10.0.0.2


The src and dst addresses are hosts' address.

mininet> h1 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group 
default qlen 1
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
        valid_lft forever preferred_lft forever
     inet6 ::1/128 scope host
        valid_lft forever preferred_lft forever
2: h1-eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state 
UP group default qlen 1000
     link/ether 96:ca:df:96:02:5c brd ff:ff:ff:ff:ff:ff link-netnsid 0
     inet 10.0.0.1/8 brd 10.255.255.255 scope global h1-eth0
        valid_lft forever preferred_lft forever
     inet6 fe80::94ca:dfff:fe96:25c/64 scope link
        valid_lft forever preferred_lft forever
mininet>
mininet> h2 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group 
default qlen 1
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
        valid_lft forever preferred_lft forever
     inet6 ::1/128 scope host
        valid_lft forever preferred_lft forever
2: h2-eth0@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state 
UP group default qlen 1000
     link/ether 92:77:ef:99:58:53 brd ff:ff:ff:ff:ff:ff link-netnsid 0
     inet 10.0.0.2/8 brd 10.255.255.255 scope global h2-eth0
        valid_lft forever preferred_lft forever
     inet6 fe80::9077:efff:fe99:5853/64 scope link
        valid_lft forever preferred_lft forever
mininet>


Thanks,
Iwase


>
> I read that i can ask at the switch what match field it must send at the 
> controller, with switch_features_handler but nothing happenz.
>
> I have write a code like this:
>
>  mod = parser.OFPFlowMod(datapath=datapath,
>                                 priority=0,
>                                 #Requires eth_type: 0x0800 (IPv4) or 
> eth_type: 0x86dd (IPv6) in match conditions
>                                 
> match=parser.OFPMatch(eth_type=0x0800),#ether_types.ETH_TYPE_IP),
>                                 instructions=inst)
>  datapath.send_msg(mod)
>
> (in switch_features_handler)
>
>
> Thank you for your time, Luca Spinazzè
>
> ________________________________
> Da: Iwase Yusuke <[email protected]>
> Inviato: lunedì 28 novembre 2016 00.47.27
> A: Spinazze' Luca
> Cc: [email protected]
> Oggetto: Re: [Ryu-devel] Some question about how manage packet_in
>
> Hi,
>
> You can use "Packet Library" to analyze packet data in Packet-In messages.
> Please refer to Ryu-Book:
>    http://osrg.github.io/ryu-book/en/html/packet_lib.html
> or API reference of Ryu-Documentation:
>    http://ryu.readthedocs.io/en/latest/library_packet.html
>
> Thanks,
> Iwase
>
>
> On 2016年11月28日 02:34, Spinazze' Luca wrote:
>> Hello, i'm Luca Spinazzè an italian student from Udine. I study for my 
>> thesis Openflow and SDN.
>>
>> I'm trying to use the controller ryu for manage the packet_in in this method:
>>
>> if the controller have a packet_in i want see the ip source of the packet_in 
>> (not about switch) that generated the "problem".
>>
>> My problem is set how switch give me the fields on packet_in, now when i 
>> print the message i can see only port_in or mac_address. Can i set that i 
>> want a packet_in with the fields like :eth.src, eth.dst, ipv4.src, ipv4.dst 
>> ... ?
>>
>> I hope that my bad english explane enough my problem, thank you for a answer!
>>
>> Luca Spinazzè
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
>>
>> _______________________________________________
>> Ryu-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/ryu-devel
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
>> _______________________________________________
>> Ryu-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/ryu-devel
------------------------------------------------------------------------------
_______________________________________________
Ryu-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ryu-devel

Reply via email to