[pox-dev] Defining Dictionary in POX controller

[Sayed Qaiser Ali Shah]

Hello Murphy First of all Thank you so much for your help. I did what I
wanted to achieve. I used following code. but the problem is after sending
some packets (I am using Ping) then ping operation stops. When I checked
dictionary I didn't find all the records which were present in dictionary
before receiving Flow removed message.


 def _handle_FlowRemoved (self, event):
      if not event.idleTimeout: return # Only care about idle timeouts
      print "entry for %s -> %s removed" % (event.ofp.match.dl_src,
event.ofp.match.dl_dst)
      for a in self.macaddrtable:
      # macaddrtable dictionary contains source mac, destination mac,
nw_proto and dl_type
      if
(event.ofp.match.dl_src,event.ofp.match.dl_dst,ipproto_to_str(event.ofp.match.nw_proto),ethtype_to_str(event.ofp.match.dl_type))
==self.macaddrtable[a]:
        #Replace entry which is deleted from switch and when message
received then the same entry is removed from macaddrtable dictionary.
        self.macaddrtable[a]=''
      # sorting records in macaddrtable dictionary and move empty records
at the end.
      for a in self.macaddrtable:
        if self.macaddrtable[a]=='':
           for b in self.macaddrtable:
             if b>a and self.macaddrtable[b]!='':
                self.macaddrtable[a]=self.macaddrtable[b]
                self.macaddrtable[b]=''
                print a, "is replaced by",b
                break


On Thu, Nov 28, 2013 at 12:48 AM, Murphy McCauley <murphy.mccauley at gmail.com
> wrote:

> It’s not too surprising that the code doesn’t work.  Among other things, I
> think it’s from Ryu and not POX.
>
> I mentioned this before, but with some additional detail, you need to do
> the following three things:
>
> 1. Write a handler for flow removed messages.  It might be a method in
> which case it’ll have a "self" parameter, or vary in other ways, but it
> might look something more or less like:
>
> def _handle_FlowRemoved (event):
>   if not event.idleTimeout: return # Only care about idle timeouts
>   print "entry for %s -> %s removed" % (event.match.dl_src,
> event.match.dl_dst)
>
>
> 2. Listen to the FlowRemoved event.  There are several ways to do this;
> the best one may depend on other aspects of your code.  You could listen to
> the event for all switches (core.openflow), or from a specific connection.
>  But it might look something like:
>
> core.openflow.addListenerByName("FlowRemoved", _handle_FlowRemoved)
>
>
> 3. When you create a table entry, set the flag so that the switch sends a
> flow removed message.  This might look something like:
>
> fm = of.ofp_flow_mod()
> …
> fm.flags = of.OFPFF_SEND_FLOW_REM
> …
> connection.send(fm)
>
>
> Some recommended reading from the manual:
>
> The Event System (introduction)
> Handling Events
> OpenFlow in POX (introduction)
> OpenFlow Events
>
>
> Hope that helps.
>
> -- Murphy
>
> On Nov 27, 2013, at 11:07 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
>
> > I used code below for flow removed handling. I got it from internet
> >
> >   def flow_removed_handler(self, ev):
> >       msg = ev.msg
> >       print msg
> >       dp = msg.datapath
> >       ofp = dp.ofproto
> >       if msg.reason == ofp.OFPRR_IDLE_TIMEOUT:
> >           reason = 'IDLE TIMEOUT'
> >       elif msg.reason == ofp.OFPRR_HARD_TIMEOUT:
> >           reason = 'HARD TIMEOUT'
> >       elif msg.reason == ofp.OFPRR_DELETE:
> >           reason = 'DELETE'
> >       else:
> >           reason = 'unknown'
> >       self.logger.info('OFPFlowRemoved received: '
> >                         'match=%s cookie=%d priority=%d reason=%s '
> >                         'duration_sec=%d duration_nsec=%d '
> >                         'idle_timeout=%d packet_count=%d byte_count=%d',
> >                         msg.match, msg.cookie, msg.priority, reason,
> >                         msg.duration_sec, msg.duration_nsec,
> >                         msg.idle_timeout, msg.packet_count,
> msg.byte_count)
> >
> >
> > The code I used didn't work. How to make the code functional. I know it
> is not listening to flow removed message. How to make it enable so that it
> can listen flow removed message.
> >
> >
> >
> > On Wed, Nov 27, 2013 at 4:45 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > Yup dear thank you so much. I will try this.
> > :)
> >
> >
> > On Wed, Nov 27, 2013 at 4:49 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > On Nov 26, 2013, at 12:26 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> >
> > > Dear Murphy I tried a lot but I am unable to use the flag properly.
> Kindly help me out in the scenario. I want to remove all entries from
> dictionary defined after idle_time_out. The pseudocode is as below.
> > >     msg.idle_timeout = 10
> > >     if msg.idle_timeout== True:
> > >         self.macaddrtable=' '
> >
> > This isn't the right logic.  You tell the switch you want a flow to
> expire if it has timed out.  Only the switch knows when this has happened.
>  If you want to find out at the controller, you need to switch to tell you.
> >
> > So when you install the flow entry with an idle_timeout, set the
> flow-mod's .flag attribute to OFPFF_SEND_FLOW_REM.
> >
> > Additionally, set a handler for the OpenFlow componet's FlowRemoved
> event.
> >
> > When the FlowRemoved handler is executed, it's because a flow has been
> removed.
> >
> > See the POX manual for more info on the FlowRemoved event and setting
> event handlers.
> >
> > As a last note, you probably want to do self.macaddrtable.clear() or
> something rather than assigning it to be an empty string?
> >
> > Hope that gets you started.
> >
> > -- Murphy
> >
> > > Kindly help me out because I am unable to do this.
> > >
> > >
> > > On Sun, Nov 24, 2013 at 2:50 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > > Like the rest of OpenFlow, it's described in the OpenFlow
> specification:
> > > http://archive.openflow.org/documents/openflow-spec-v1.0.0.pdf
> > >
> > > Also, if you google "OFPFF_SEND_FLOW_REM pox" you should get several
> examples of setting the flag.
> > >
> > > In the POX wiki manual, there is some description of the FlowRemoved
> event and of handling events in general.
> > >
> > >
> > > -- Murphy
> > >
> > > On Nov 23, 2013, at 10:51 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >
> > >> I tried to used OFPFF_SEND_FLOW_REM flag and also searched on net but
> didn't get any specific answer. Please tell me how to use this flag? or
> give me a link from which I can get help.
> > >> Thanks
> > >>
> > >>
> > >> On Sat, Nov 23, 2013 at 7:28 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >> I think so. I want to delete entry from dictionary defined on
> controller. Thanks. I will try this.
> > >>
> > >>
> > >> On Sat, Nov 23, 2013 at 11:04 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>
> > >> On Nov 22, 2013, at 12:57 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>
> > >>> Hello Murphy McCauley,
> > >>>
> > >>> I solved the duplication problem now I want to refresh the
> dictionary I have defined after an idle_timeout. I want to set idle_timeout
> to 10. I tried this but didn't get what I wanted.
> > >>>
> > >>> msg.idle_timeout = 10
> > >>>     if msg.idle_timeout== True:
> > >>>         self.macaddrtable=' '
> > >>>
> > >>> This will destroy all entries in dictionary. Is there any other way
> so that only that entry whose idle_timeout has expired is removed and then
> rearrange remaining entries in dictionary.
> > >>> Just as a reminder. macaddrtable is dictionary defined which
> contains source and destination mac addresses. When a packet arrives
> controller its entry is saved in the dictionary macaddrtable.
> > >>
> > >> If you set the OFPFF_SEND_FLOW_REM flag when installing the table
> entry, you'll get a FlowRemoved event when it expires.  Maybe that's what
> you need?
> > >>
> > >> -- Murphy
> > >>
> > >>> On Fri, Nov 15, 2013 at 6:05 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>> Ok thank you I will check it out.
> > >>>
> > >>>
> > >>> On Fri, Nov 15, 2013 at 5:54 PM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>> I'm just suggesting you work backwards to find the problem.  Use
> Wireshark to monitor the traffic to help determine where the duplicates are
> coming from.  If they're coming from a switch, I suggest you inspect the
> table on that switch to see which table entry the switch.  Then analyze the
> OpenFlow traffic to that switch to find the OpenFlow messages which
> installed the problematic entries.  Then analyze your controller code to
> see where you sent those problematic entries.
> > >>> -- Murphy
> > >>>
> > >>>
> > >>> On Nov 15, 2013, at 4:49 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>>
> > >>>> Thank you so much. Yes you are right about what you said but is
> there is any other way, so that I can do this. I can read individual
> entries statically but the problem is I want to get it dynamic.
> > >>>> Like I can print individual entries by using:
> > >>>>
> > >>>> print self.macaddrtable[1]
> > >>>> print self.macaddrtable[2]
> > >>>> print self.macaddrtable[3]
> > >>>> print self.macaddrtable[4]
> > >>>>
> > >>>> To get desired result dynamically I used loop. But you know what I
> got. :(
> > >>>>
> > >>>>
> > >>>> On Fri, Nov 15, 2013 at 3:36 PM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>>>
> > >>>> On Nov 15, 2013, at 2:20 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>>>
> > >>>>> Hello Murphy actually I am working on Traffic Engineering. I am
> now learning that how to forward traffic when we have dictionary on
> controller. I want to forward some entries of dictionary via queue-1 and
> some entries via queue-2. For this I have created dictionary and it created
> successfully with you help. Those entries of dictionary contain Source Mac
> Address and Destination Mac address. I created 2 queues on Interface 1 of
> switch. I then Pinged host 2 from host 1 and host 1 from host 3. It
> inserted four entries in dictionary created on controller. Entries in
> Dictionary are
> > >>>>> {1: (EthAddr('00:00:00:00:00:02'), EthAddr('00:00:00:00:00:01')),
> > >>>>>  2: (EthAddr('00:00:00:00:00:01'), EthAddr('00:00:00:00:00:02')),
> > >>>>>  3: (EthAddr('00:00:00:00:00:01'), EthAddr('00:00:00:00:00:03')),
> > >>>>>  4: (EthAddr('00:00:00:00:00:03'), EthAddr('00:00:00:00:00:01')) }
> > >>>>> Dear Murphy you asked earlier that you didn't get what I wanted to
> do. I think that I am just explaining it in easy way that I just want to
> forward two entries of dictionary via queue-1 and other 2 entries of
> dictionary via queue-2. I am just doing practice on different techniques of
> Traffic Engineering.  I used the following code for forwarding traffic via
> queues:
> > >>>>>
> > >>>>> if self.macaddrtable=='':      //When we have no entry in
> macaddrtable dictionary
> > >>>>>         queue=1
> > >>>>>         msg.actions.append(of.ofp_action_enqueue(port = port,
> queue_id = queue))
> > >>>>> else:
> > >>>>>     for a in self.macaddrtable:
> > >>>>>          if a<=2:
> > >>>>>             queue=1
> > >>>>>             msg.actions.append(of.ofp_action_enqueue(port = port,
> queue_id = queue))
> > >>>>>          elif a>2:
> > >>>>>             queue=2
> > >>>>>             msg.actions.append(of.ofp_action_enqueue(port = port,
> queue_id = queue))
> > >>>>>
> > >>>>> The code worked fine and forwarded traffic via desired queues but
> after about 10 seconds of pinging, duplicate packets were detected. I don't
> know why duplicate packets were detected. Can you please tell the reason?
> > >>>>
> > >>>> My best guesses are that you are somehow creating a flow entry with
> multiple actions or a loop, but it's hard to say.  I'd suggest that you try
> to use Wireshark or a similar tool to figure out where the duplicates are
> coming from.  You should see the duplicates at the port of the destination
> host and the egress port of the last switch.  Work backwards from there.
>  If you find the source of the duplications is a switch, examine the flow
> table of that switch and see if you can spot the reason.
> > >>>>
> > >>>> -- Murphy
> > >>>>
> > >>>>> On Tue, Nov 12, 2013 at 2:00 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>>>> It's still hard for me to answer questions since I still don't
> know what you're really trying to accomplish here.
> > >>>>>
> > >>>>> If you want entries to time out on the switch, set timeouts when
> installing the table entry (sending the flow_mod).  If you want
> notifications when flows are removed on the switch, that's also an option
> you can set when installing the entry; then listen to the FlowRemoved event
> to tell when it has actually happened.
> > >>>>>
> > >>>>> I'm not sure what you mean by "exact mac".  Your code records the
> address the packets were sent to.  If they were sent to the broadcast
> address, then... that's the destination.
> > >>>>>
> > >>>>> -- Murphy
> > >>>>>
> > >>>>> On Nov 11, 2013, at 9:42 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>>>>
> > >>>>>> Thank you so much Murphy for your help. I did it the way you
> explained. But how can I refresh entries in the table. i.e. how to set idle
> timeout and hard timeout for this so that the table can be refreshed or how
> the entries can be updated when a flow is removed from flow table on Switch.
> > >>>>>> Another Problem is:
> > >>>>>> The code is as below.
> > >>>>>>
> > >>>>>> if (packet.src,packet.dst) not in self.macaddrs and
> (packet.dst,packet.src) not in self.macaddrs:
> > >>>>>>         self.macaddrs.add((packet.src,packet.dst))
> > >>>>>>         self.macaddrtable[f_id]=(packet.src,packet.dst)
> > >>>>>>         f_id=f_id+1
> > >>>>>> print "Mac Table is "
> > >>>>>> print self.macaddrtable
> > >>>>>>
> > >>>>>> When I created a topology with 3 hosts the following result was
> shown
> > >>>>>>
> > >>>>>> Mac Table is
> > >>>>>> {1: (EthAddr('00:00:00:00:00:01'), EthAddr('ff:ff:ff:ff:ff:ff')),
> 2: (EthAddr('00:00:00:00:00:02'), EthAddr('00:00:00:00:00:01')), 3:
> (EthAddr('00:00:00:00:00:03'), EthAddr('00:00:00:00:00:01')), 4:
> (EthAddr('00:00:00:00:00:02'), EthAddr('ff:ff:ff:ff:ff:ff')), 5:
> (EthAddr('00:00:00:00:00:03'), EthAddr('00:00:00:00:00:02'))}
> > >>>>>>
> > >>>>>> The result I expected is little bit different in terms of
> broadcast address. Like in 1 destination mac is ff:ff:ff:ff:ff:ff but I was
> expecting 00:00:00:00:00:02 and similar is the case with some other entries
> as well.
> > >>>>>> Is there any way so that I can get desired exact mac, not
> broadcast?
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>> On Sun, Nov 10, 2013 at 5:00 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>>>>> It sounds like you need to record them as a pair to get what you
> want, so ... put them in as a pair.
> > >>>>>>
> > >>>>>> It looks like I may have been responsible for the problem you
> were seeing -- a little typo inserted an errant right square bracket.  Try:
> > >>>>>> self.macaddrs.add((packet.src,packet.dst))
> > >>>>>>
> > >>>>>> It's still not clear from context whether ordering matters to you
> (is A sending to B the same as B sending to A?).  If it isn't, you might
> want to sort the two addresses or just check for both...
> > >>>>>>
> > >>>>>> if (packet.src,packet.dst) not in self.macaddrs and
> (packet.dst,packet.src) not in self.macaddrs:
> > >>>>>>
> > >>>>>> -- Murphy
> > >>>>>>
> > >>>>>> On Nov 9, 2013, at 3:32 PM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>>>>>
> > >>>>>>> Thank you so much Murphy. I tried it but got little problem in
> add function i.e. when I used
> > >>>>>>> self.macaddrs.add((packet.src,packet.dst])) it generated error
> in this function then I tried
> > >>>>>>> self.macaddrs.add(packet.src,packet.dst)
> > >>>>>>> It also generated an error that add must have 1 argument where
> as 2 given. Then I tried
> > >>>>>>>
> > >>>>>>> if (packet.src,packet.dst) not in self.macaddrs:
> > >>>>>>>   self.macaddrs.add(packet.src)
> > >>>>>>>   self.macaddrs.add(packet.dst)
> > >>>>>>>   self.macaddrtable[f_id]=(packet.src,packet.dst)
> > >>>>>>>   f_id=f_id+1
> > >>>>>>>
> > >>>>>>> It didn't generate an error and I didn't get any repeated result
> but there was some problem in the code I got results as below.
> > >>>>>>> When I ping host1 from host 2 it added record in dictionary.
> Then I ping host 3 from h1 record was inserted again but the problem was,
> as record of host 1, host 2 and host 3 was saved in macaddrs and two
> records were there but when I pinged the hosts present in macaddrs i.e. 1,
> 2, 3 like I ping host 2 from h3 as record was not present in macaddrtable
> still record was not added to dictionary. It is because addresses are
> saving in macaddrs one by one individually i.e. first source and then
> destination address. When packet arrives controller it checks for source
> and destination address in macaddrs as when there are individual record of
> each host it then doesn't execute IF body because source and destination
> addresses are already there as individual address. What to do with this????
> Kindly help.
> > >>>>>>>
> > >>>>>>>
> > >>>>>>> On Sun, Nov 10, 2013 at 3:26 AM, Murphy McCauley <
> murphy.mccauley at gmail.com> wrote:
> > >>>>>>> One possible answer is that you should keep a set of the ones
> you've added so far...
> > >>>>>>> self.macaddrtable = {}
> > >>>>>>> self.macaddrs = set()
> > >>>>>>>
> > >>>>>>> ...
> > >>>>>>>
> > >>>>>>> if (packet.src,packet.dst) not in self.macaddrs:
> > >>>>>>>   self.macaddrs.add((packet.src,packet.dst]))
> > >>>>>>>   self.macaddrtable[f_id]=(packet.src,packet.dst)
> > >>>>>>>   f_id=f_id+1
> > >>>>>>>
> > >>>>>>>
> > >>>>>>> There might be better things to be done, but it's impossible to
> say without knowing more (e.g., what you're trying to accomplish, what f_id
> is used for, etc.).
> > >>>>>>>
> > >>>>>>> -- Murphy
> > >>>>>>>
> > >>>>>>> On Nov 9, 2013, at 10:35 AM, Sayed Qaiser Ali Shah <
> 11msitqshah at seecs.edu.pk> wrote:
> > >>>>>>>
> > >>>>>>> > Hello everybody,
> > >>>>>>> >
> > >>>>>>> > I have defined dictionary in POX controller and I by the name
> addrtable and I am saving two things in this dictionary i.e. Source mac and
> destination mac. What I have done is
> > >>>>>>> >
> > >>>>>>> >     self.macaddrtable = {}
> > >>>>>>> > ...
> > >>>>>>> >     f_id=1
> > >>>>>>> >     self.macaddrtable[f_id]={packet.src, packet.dst}
> > >>>>>>> >     print self.macaddrtable
> > >>>>>>> >     f_id=f_id+1
> > >>>>>>> >
> > >>>>>>> > It is saving source mac and destination mac in the dictionary
> but the problem is when f_id increases it then save same source and
> destination mac again and again.
> > >>>>>>> > What I want is to save mac address only if its not in
> dictionary.
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>> --
> > >>>>>>> Regards
> > >>>>>>>
> > >>>>>>> Sayed Qaiser Ali Shah
> > >>>>>>> MSIT-12
> > >>>>>>> NUST (SEECS)
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>> --
> > >>>>>> Regards
> > >>>>>>
> > >>>>>> Sayed Qaiser Ali Shah
> > >>>>>> MSIT-12
> > >>>>>> NUST (SEECS)
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>> --
> > >>>>> Regards
> > >>>>>
> > >>>>> Sayed Qaiser Ali Shah
> > >>>>> MSIT-12
> > >>>>> NUST (SEECS)
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>> --
> > >>>> Regards
> > >>>>
> > >>>> Sayed Qaiser Ali Shah
> > >>>> MSIT-12
> > >>>> NUST (SEECS)
> > >>>
> > >>>
> > >>>
> > >>>
> > >>> --
> > >>> Regards
> > >>>
> > >>> Sayed Qaiser Ali Shah
> > >>> MSIT-12
> > >>> NUST (SEECS)
> > >>>
> > >>>
> > >>>
> > >>> --
> > >>> Regards
> > >>>
> > >>> Sayed Qaiser Ali Shah
> > >>> MSIT-12
> > >>> NUST (SEECS)
> > >>
> > >>
> > >>
> > >>
> > >> --
> > >> Regards
> > >>
> > >> Sayed Qaiser Ali Shah
> > >> MSIT-12
> > >> NUST (SEECS)
> > >>
> > >>
> > >>
> > >> --
> > >> Regards
> > >>
> > >> Sayed Qaiser Ali Shah
> > >> MSIT-12
> > >> NUST (SEECS)
> > >
> > >
> > >
> > >
> > > --
> > > Regards
> > >
> > > Sayed Qaiser Ali Shah
> > > MSIT-12
> > > NUST (SEECS)
> >
> >
> >
> >
> > --
> > Regards
> >
> > Sayed Qaiser Ali Shah
> > MSIT-12
> > NUST (SEECS)
> >
> >
> >
> > --
> > Regards
> >
> > Sayed Qaiser Ali Shah
> > MSIT-12
> > NUST (SEECS)
>
>


-- 




*RegardsSayed Qaiser Ali ShahMSIT-12NUST (SEECS)*
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