Hi, I am sorry for sending in five attachments, I cloned the code from here
<https://bitbucket.org/msharif/hedera/src>: Let me explain it here:
Routing Base class defined in DCRouting.py:
import logging
from copy import copy
class Routing(object):
'''Base class for data center network routing.
Routing engines must implement the get_route() method.
'''
def __init__(self, topo):
'''Create Routing object.
@param topo Topo object from Net parent
'''
self.topo = topo
def get_route(self, src, dst, hash_):
'''Return flow path.
@param src source host
@param dst destination host
@param hash_ hash value
@return flow_path list of DPIDs to traverse (including hosts)
'''
raise NotImplementedError
def routes(self, src, dst):
''' Return list of paths
Only works for Fat-Tree topology
@ param src source host
@ param dst destination host
@ return list of DPIDs (including inputs)
'''
complete_paths = [] # List of complete dpid routes
src_paths = { src : [[src]] }
dst_paths = { dst : [[dst]] }
dst_layer = self.topo.layer(dst)
src_layer = self.topo.layer(src)
lower_layer = src_layer
if dst_layer > src_layer:
lower_layer = dst_layer
for front_layer in range(lower_layer-1, -1, -1):
if src_layer > front_layer:
# expand src frontier
new_src_paths = {}
for node in sorted(src_paths):
path_list = src_paths[node]
for path in path_list:
last_node = path[-1]
for frontier_node in
self.topo.upper_nodes(last_node):
new_src_paths[frontier_node] = [path +
[frontier_node]]
if frontier_node in dst_paths:
dst_path_list = dst_paths[frontier_node]
for dst_path in dst_path_list:
dst_path_copy = copy ( dst_path )
dst_path_copy.reverse()
complete_paths.append( path +
dst_path_copy)
src_paths = new_src_paths
if dst_layer > front_layer:
# expand dst frontier
new_dst_paths = {}
for node in sorted(dst_paths):
path_list = dst_paths[node]
for path in path_list:
last_node = path[-1]
for frontier_node in
self.topo.upper_nodes(last_node):
new_dst_paths[frontier_node] = [ path +
[frontier_node]]
if frontier_node in src_paths:
src_path_list = src_paths[frontier_node]
dst_path_copy = copy( path )
dst_path_copy.reverse()
for src_path in src_path_list:
complete_paths.append( src_path +
dst_path_copy)
dst_paths = new_dst_paths
if complete_paths:
return complete_paths
class HashedRouting(Routing):
''' Hashed routing '''
def __init__(self, topo):
self.topo = topo
def get_route(self, src, dst, hash_):
''' Return flow path. '''
if src == dst:
return [src]
paths = self.routes(src,dst)
if paths:
#print 'hash_:', hash_
choice = hash_ % len(paths)
#print 'choice:', choice
path = sorted(paths)[choice]
#print 'path:', path
return path
============>
Instantiated in util.py:
from DCTopo import FatTreeTopo
from mininet.util import makeNumeric
from DCRouting import HashedRouting, Routing
TOPOS = {'ft': FatTreeTopo}
ROUTING = {'ECMP' : HashedRouting}
def buildTopo(topo):
topo_name, topo_param = topo.split( ',' )
return TOPOS[topo_name](makeNumeric(topo_param))
def getRouting(routing, topo):
return ROUTING[routing](topo)
============================> utilized in HController. py:
A Piece of code which works with self.r.routes() method:
Following list of methods are defined in HController.py
def _ecmp_hash(self, packet):
''' Return an ECMP-style 5-tuple hash for TCP/IP packets, otherwise
0.
RFC2992 '''
hash_input = [0] * 5
if isinstance(packet.next, ipv4):
ip = packet.next
hash_input[0] = ip.srcip.toUnsigned()
hash_input[1] = ip.dstip.toUnsigned()
hash_input[2] = ip.protocol
if isinstance(ip.next, tcp) or isinstance(ip.next, udp):
l4 = ip.next
hash_input[3] = l4.srcport
hash_input[4] = l4.dstport
return crc32(pack('LLHHH', *hash_input))
return 0
def _install_reactive_path(self, event, out_dpid, final_out_port,
packet):
''' Install entries on route between two switches. '''
in_name = self.t.node_gen(dpid = event.dpid).name_str()
out_name = self.t.node_gen(dpid = out_dpid).name_str()
hash_ = self._ecmp_hash(packet)
paths = self.r.routes(src_name, dst_name)
if paths == None:
print "PATH is None :("
return
route = self.r.get_route(in_name, out_name, hash_)
print "Route:",route
print '-'*80
if route == None:
print None, "route between", in_name, "and", out_name
return
match = of.ofp_match.from_packet(packet)
for i, node in enumerate(route):
node_dpid = self.t.node_gen(name = node).dpid
if i < len(route) - 1:
next_node = route[i + 1]
out_port, next_in_port = self.t.port(node, next_node)
else:
out_port = final_out_port
self.switches[node_dpid].install(out_port, match, idle_timeout
= 10)
if isinstance(packet.next, of.ipv4) and
isinstance(packet.next.next, of.tcp):
self.matchDict[(packet.next.srcip, packet.next.dstip,
packet.next.next.srcport, packet.next.next.dstport)] = (route, match)
def _handle_PacketIn(self, event):
if not self.all_switches_up:
#log.info("Saw PacketIn before all switches were up -
ignoring." )
return
packet = event.parsed
dpid = event.dpid
in_port = event.port
# Learn MAC address of the sender on every packet-in.
self.macTable[packet.src] = (dpid, in_port)
sw_name = self.t.node_gen(dpid = dpid).name_str()
#print "Sw:", sw_name, packet.src, packet.dst,"port", in_port,
packet.dst.isMulticast(),"macTable", packet.dst in self.macTable
#print '-'*80
# Insert flow, deliver packet directly to destination.
if packet.dst in self.macTable:
out_dpid, out_port = self.macTable[packet.dst]
self._install_reactive_path(event, out_dpid, out_port, packet)
self.switches[out_dpid].send_packet_data(out_port, event.data)
else:
self._flood(event)
===================> code snippet which returns 'None' number of paths.
def _GlobalFirstFit(self,flow):
'''do the Hedera global first fit here'''
src_name = self.t.node_gen(dpid = flow['src']).name_str()
dst_name = self.t.node_gen(dpid = flow['dst']).name_str()
print 'Global Fisrt Fit for the elephant flow from ',src_name,'to',
dst_name
paths = self.r.routes(src_name,dst_name)
print 'all routes found for the big flow:\n',paths
GFF_route = None
if paths == None:
return
else:
for path in paths:
fitCheck = True
for i in range(1,len(path)):
fitCheck = False
if self.bwReservation.has_key(path[i-1]) and
self.bwReservation[path[i-1]].has_key(path[i]):
if
self.bwReservation[path[i-1]][path[i]]['reserveDemand'] + flow['demand'] >
1 :
break
else:
#self.bwReservation[path[i-1]][path[i]]['reserveDemand'] += flow['demand']
fitCheck = True
else:
self.bwReservation[path[i-1]]={}
self.bwReservation[path[i-1]][path[i]]={'reserveDemand':0}
fitCheck = True
if fitCheck == True:
for i in range(1,len(path)):
self.bwReservation[path[i-1]][path[i]]['reserveDemand']
+= flow['demand']
GFF_route = path
print "GFF route found:", path
break
if GFF_route != None:
"""install new GFF_path between source and destintaion"""
self. _install_GFF_path(GFF_route,flow['match'])
def launch(topo = None, routing = None, bw = None ):
#print topo
if not topo:
raise Exception ("Please specify the topology")
else:
t = buildTopo(topo)
r = getRouting(routing, t)
if bw == None:
bw = 10.0 #Mb/s
bw = float(bw/1000) #Gb/s
else:
bw = float(bw)/1000
core.registerNew(HController, t, r, bw)
log.info("** HController is running
I am really sorry for any inconvenience caused. I, ve tried to make it a
bit clear here. I am not even able to debug the code by setting a python
debugging point pdb. I need help from you guys. Thanks a lot again for your
time and help.
Best Regards,
David
On Sat, May 9, 2015 at 12:07 PM, Mark Lawrence <breamore...@yahoo.co.uk>
wrote:
> On 09/05/2015 07:41, david jhon wrote:
>
>> Hello everyone,
>>
>> I am new to python and trying to run an example code from mininet tests.
>> Basically, I am trying to call a method in Hcontroller.py from base class
>> Routing defined in DCRouting.py which runs and fetches all the required
>> results in install_reactive_path() method, but it returns None when it is
>> called from _GlobalFirstFit. I hope someone here could help me fix this
>> bug..
>>
>> I am attaching all the three files(DCRouting.py, HController.py, util.py)
>> to have a look into. Thanks in advance for your time, help or suggestion.
>> Thanks a lot!
>>
>> kind regards,
>> David
>>
>>
> I'm sorry but I'm not wading through nearly 30kb of code in five
> attachments. Please see http://sscce.org/ for how to put your question
> so you're more likely to get answers.
>
> --
> My fellow Pythonistas, ask not what our language can do for you, ask
> what you can do for our language.
>
> Mark Lawrence
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list
