Fix VLAN range of setChain
[osm/vim-emu.git] / src / emuvim / dcemulator / net.py
index 1adc8bc..3eee2e5 100755 (executable)
@@ -1,26 +1,61 @@
 """
 """
-Distributed Cloud Emulator (dcemulator)
-(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+Copyright (c) 2015 SONATA-NFV and Paderborn University
+ALL RIGHTS RESERVED.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
+nor the names of its contributors may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+This work has been performed in the framework of the SONATA project,
+funded by the European Commission under Grant number 671517 through
+the Horizon 2020 and 5G-PPP programmes. The authors would like to
+acknowledge the contributions of their colleagues of the SONATA
+partner consortium (www.sonata-nfv.eu).
 """
 import logging
 
 import site
 import time
 from subprocess import Popen
 """
 import logging
 
 import site
 import time
 from subprocess import Popen
-import os
 import re
 import re
-import urllib2
-from functools import partial
+import requests
+import os
+import json
 
 from mininet.net import Containernet
 from mininet.node import Controller, DefaultController, OVSSwitch, OVSKernelSwitch, Docker, RemoteController
 from mininet.cli import CLI
 from mininet.link import TCLink
 
 from mininet.net import Containernet
 from mininet.node import Controller, DefaultController, OVSSwitch, OVSKernelSwitch, Docker, RemoteController
 from mininet.cli import CLI
 from mininet.link import TCLink
+from mininet.clean import cleanup
 import networkx as nx
 from emuvim.dcemulator.monitoring import DCNetworkMonitor
 import networkx as nx
 from emuvim.dcemulator.monitoring import DCNetworkMonitor
-from emuvim.dcemulator.node import Datacenter, EmulatorCompute
+from emuvim.dcemulator.node import Datacenter, EmulatorCompute, EmulatorExtSAP
 from emuvim.dcemulator.resourcemodel import ResourceModelRegistrar
 
 from emuvim.dcemulator.resourcemodel import ResourceModelRegistrar
 
+LOG = logging.getLogger("dcemulator.net")
+LOG.setLevel(logging.DEBUG)
+
+# default CPU period used for cpu percentage-based cfs values (microseconds)
+CPU_PERIOD = 1000000
+
+# default priority setting for added flow-rules
+DEFAULT_PRIORITY = 1000
+# default cookie number for new flow-rules
+DEFAULT_COOKIE = 10
+
 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides
 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides
@@ -30,7 +65,7 @@ class DCNetwork(Containernet):
     """
 
     def __init__(self, controller=RemoteController, monitor=False,
     """
 
     def __init__(self, controller=RemoteController, monitor=False,
-                 enable_learning = True,   # in case of RemoteController (Ryu), learning switch behavior can be turned off/on
+                 enable_learning=False, # learning switch behavior of the default ovs switches icw Ryu controller can be turned off/on, needed for E-LAN functionality
                  dc_emulation_max_cpu=1.0,  # fraction of overall CPU time for emulation
                  dc_emulation_max_mem=512,  # emulation max mem in MB
                  **kwargs):
                  dc_emulation_max_cpu=1.0,  # fraction of overall CPU time for emulation
                  dc_emulation_max_mem=512,  # emulation max mem in MB
                  **kwargs):
@@ -40,18 +75,36 @@ class DCNetwork(Containernet):
         :param kwargs: path through for Mininet parameters
         :return:
         """
         :param kwargs: path through for Mininet parameters
         :return:
         """
+        # members
         self.dcs = {}
         self.dcs = {}
+        self.ryu_process = None
+        #list of deployed nsds.E_Lines and E_LANs (uploaded from the dummy gatekeeper)
+        self.deployed_nsds = []
+        self.deployed_elines = []
+        self.deployed_elans = []
+        self.installed_chains = []
+
+
+        # always cleanup environment before we start the emulator
+        self.killRyu()
+        cleanup()
 
         # call original Docker.__init__ and setup default controller
         Containernet.__init__(
             self, switch=OVSKernelSwitch, controller=controller, **kwargs)
 
 
         # call original Docker.__init__ and setup default controller
         Containernet.__init__(
             self, switch=OVSKernelSwitch, controller=controller, **kwargs)
 
+        # default switch configuration
+        enable_ryu_learning = False
+        if enable_learning :
+            self.failMode = 'standalone'
+            enable_ryu_learning = True
+        else:
+            self.failMode = 'secure'
 
         # Ryu management
 
         # Ryu management
-        self.ryu_process = None
         if controller == RemoteController:
             # start Ryu controller
         if controller == RemoteController:
             # start Ryu controller
-            self.startRyu(learning_switch=enable_learning)
+            self.startRyu(learning_switch=enable_ryu_learning)
 
         # add the specified controller
         self.addController('c0', controller=controller)
 
         # add the specified controller
         self.addController('c0', controller=controller)
@@ -60,12 +113,13 @@ class DCNetwork(Containernet):
         self.DCNetwork_graph = nx.MultiDiGraph()
 
         # initialize pool of vlan tags to setup the SDN paths
         self.DCNetwork_graph = nx.MultiDiGraph()
 
         # initialize pool of vlan tags to setup the SDN paths
-        self.vlans = range(4096)[::-1]
+        self.vlans = range(1, 4096)[::-1]
 
         # link to Ryu REST_API
 
         # link to Ryu REST_API
-        ryu_ip = '0.0.0.0'
+        ryu_ip = 'localhost'
         ryu_port = '8080'
         self.ryu_REST_api = 'http://{0}:{1}'.format(ryu_ip, ryu_port)
         ryu_port = '8080'
         self.ryu_REST_api = 'http://{0}:{1}'.format(ryu_ip, ryu_port)
+        self.RyuSession = requests.Session()
 
         # monitoring agent
         if monitor:
 
         # monitoring agent
         if monitor:
@@ -76,6 +130,7 @@ class DCNetwork(Containernet):
         # initialize resource model registrar
         self.rm_registrar = ResourceModelRegistrar(
             dc_emulation_max_cpu, dc_emulation_max_mem)
         # initialize resource model registrar
         self.rm_registrar = ResourceModelRegistrar(
             dc_emulation_max_cpu, dc_emulation_max_mem)
+        self.cpu_period = CPU_PERIOD
 
     def addDatacenter(self, label, metadata={}, resource_log_path=None):
         """
 
     def addDatacenter(self, label, metadata={}, resource_log_path=None):
         """
@@ -87,7 +142,7 @@ class DCNetwork(Containernet):
         dc.net = self  # set reference to network
         self.dcs[label] = dc
         dc.create()  # finally create the data center in our Mininet instance
         dc.net = self  # set reference to network
         self.dcs[label] = dc
         dc.create()  # finally create the data center in our Mininet instance
-        logging.info("added data center: %s" % label)
+        LOG.info("added data center: %s" % label)
         return dc
 
     def addLink(self, node1, node2, **params):
         return dc
 
     def addLink(self, node1, node2, **params):
@@ -97,7 +152,7 @@ class DCNetwork(Containernet):
         """
         assert node1 is not None
         assert node2 is not None
         """
         assert node1 is not None
         assert node2 is not None
-        logging.debug("addLink: n1=%s n2=%s" % (str(node1), str(node2)))
+
         # ensure type of node1
         if isinstance( node1, basestring ):
             if node1 in self.dcs:
         # ensure type of node1
         if isinstance( node1, basestring ):
             if node1 in self.dcs:
@@ -153,7 +208,7 @@ class DCNetwork(Containernet):
         edge_attributes = [p for p in params if p in weight_metrics]
         for attr in edge_attributes:
             # if delay: strip ms (need number as weight in graph)
         edge_attributes = [p for p in params if p in weight_metrics]
         for attr in edge_attributes:
             # if delay: strip ms (need number as weight in graph)
-            match = re.search('([0-9]*\.?[0-9]+)', params[attr])
+            match = re.search('([0-9]*\.?[0-9]+)', str(params[attr]))
             if match:
                 attr_number = match.group(1)
             else:
             if match:
                 attr_number = match.group(1)
             else:
@@ -175,29 +230,79 @@ class DCNetwork(Containernet):
         attr_dict2.update(attr_dict)
         self.DCNetwork_graph.add_edge(node2.name, node1.name, attr_dict=attr_dict2)
 
         attr_dict2.update(attr_dict)
         self.DCNetwork_graph.add_edge(node2.name, node1.name, attr_dict=attr_dict2)
 
+        LOG.debug("addLink: n1={0} intf1={1} -- n2={2} intf2={3}".format(
+            str(node1),node1_port_name, str(node2), node2_port_name))
+
         return link
 
         return link
 
+    def removeLink(self, link=None, node1=None, node2=None):
+        """
+        Remove the link from the Containernet and the networkx graph
+        """
+        if link is not None:
+            node1 = link.intf1.node
+            node2 = link.intf2.node
+        assert node1 is not None
+        assert node2 is not None
+        Containernet.removeLink(self, link=link, node1=node1, node2=node2)
+        # TODO we might decrease the loglevel to debug:
+        try:
+            self.DCNetwork_graph.remove_edge(node2.name, node1.name)
+        except:
+            LOG.warning("%s, %s not found in DCNetwork_graph." % ((node2.name, node1.name)))
+        try:
+            self.DCNetwork_graph.remove_edge(node1.name, node2.name)
+        except:
+            LOG.warning("%s, %s not found in DCNetwork_graph." % ((node1.name, node2.name)))
+
     def addDocker( self, label, **params ):
         """
         Wrapper for addDocker method to use custom container class.
         """
     def addDocker( self, label, **params ):
         """
         Wrapper for addDocker method to use custom container class.
         """
-        self.DCNetwork_graph.add_node(label)
+        self.DCNetwork_graph.add_node(label, type=params.get('type', 'docker'))
         return Containernet.addDocker(self, label, cls=EmulatorCompute, **params)
 
         return Containernet.addDocker(self, label, cls=EmulatorCompute, **params)
 
-    def removeDocker( self, label, **params ):
+    def removeDocker( self, label, **params):
         """
         Wrapper for removeDocker method to update graph.
         """
         self.DCNetwork_graph.remove_node(label)
         return Containernet.removeDocker(self, label, **params)
 
         """
         Wrapper for removeDocker method to update graph.
         """
         self.DCNetwork_graph.remove_node(label)
         return Containernet.removeDocker(self, label, **params)
 
+    def addExtSAP(self, sap_name, sap_ip, **params):
+        """
+        Wrapper for addExtSAP method to store SAP  also in graph.
+        """
+        # make sure that 'type' is set
+        params['type'] = params.get('type','sap_ext')
+        self.DCNetwork_graph.add_node(sap_name, type=params['type'])
+        return Containernet.addExtSAP(self, sap_name, sap_ip, **params)
+
+    def removeExtSAP(self, sap_name, **params):
+        """
+        Wrapper for removeExtSAP method to remove SAP  also from graph.
+        """
+        self.DCNetwork_graph.remove_node(sap_name)
+        return Containernet.removeExtSAP(self, sap_name)
+
     def addSwitch( self, name, add_to_graph=True, **params ):
         """
         Wrapper for addSwitch method to store switch also in graph.
         """
     def addSwitch( self, name, add_to_graph=True, **params ):
         """
         Wrapper for addSwitch method to store switch also in graph.
         """
+
+        # add this switch to the global topology overview
         if add_to_graph:
         if add_to_graph:
-            self.DCNetwork_graph.add_node(name)
-        return Containernet.addSwitch(self, name, protocols='OpenFlow10,OpenFlow12,OpenFlow13', **params)
+            self.DCNetwork_graph.add_node(name, type=params.get('type','switch'))
+
+        # set the learning switch behavior
+        if 'failMode' in params :
+            failMode = params['failMode']
+        else :
+            failMode = self.failMode
+
+        s = Containernet.addSwitch(self, name, protocols='OpenFlow10,OpenFlow12,OpenFlow13', failMode=failMode, **params)
+
+        return s
 
     def getAllContainers(self):
         """
 
     def getAllContainers(self):
         """
@@ -224,34 +329,77 @@ class DCNetwork(Containernet):
         Containernet.stop(self)
 
         # stop Ryu controller
         Containernet.stop(self)
 
         # stop Ryu controller
-        self.stopRyu()
+        self.killRyu()
 
 
     def CLI(self):
         CLI(self)
 
 
 
     def CLI(self):
         CLI(self)
 
-    # to remove chain do setChain( src, dst, cmd='del-flows')
-    def setChain(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
-        cmd = kwargs.get('cmd')
-        if cmd == 'add-flow':
-            ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
-            if kwargs.get('bidirectional'):
-                ret = ret +'\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
-
-        elif cmd == 'del-flows':  # TODO: del-flow to be implemented
-            ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
-            if kwargs.get('bidirectional'):
-                ret = ret + '\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
-
-        else:
-            ret = "Command unknown"
+    def setLAN(self, vnf_list):
+        """
+        setup an E-LAN network by assigning the same VLAN tag to each DC interface of the VNFs in the E-LAN
 
 
-        return ret
+        :param vnf_list: names of the VNFs in this E-LAN  [{name:,interface:},...]
+        :return:
+        """
+        src_sw = None
+        src_sw_inport_nr = 0
+        src_sw_inport_name = None
+
+        # get a vlan tag for this E-LAN
+        vlan = self.vlans.pop()
+
+        for vnf in vnf_list:
+            vnf_src_name = vnf['name']
+            vnf_src_interface = vnf['interface']
+
+            # check if port is specified (vnf:port)
+            if vnf_src_interface is None:
+                # take first interface by default
+                connected_sw = self.DCNetwork_graph.neighbors(vnf_src_name)[0]
+                link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+                vnf_src_interface = link_dict[0]['src_port_id']
+
+            for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+                link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+                for link in link_dict:
+                    if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                                link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                        # found the right link and connected switch
+                        src_sw = connected_sw
+                        src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                        src_sw_inport_name = link_dict[link]['dst_port_name']
+                        break
+
+            # set the tag on the dc switch interface
+            LOG.debug('set E-LAN: vnf name: {0} interface: {1} tag: {2}'.format(vnf_src_name, vnf_src_interface,vlan))
+            switch_node = self.getNodeByName(src_sw)
+            self._set_vlan_tag(switch_node, src_sw_inport_name, vlan)
+
+    def _addMonitorFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None,
+                       tag=None, **kwargs):
+        """
+        Add a monitoring flow entry that adds a special flowentry/counter at the begin or end of a chain.
+        So this monitoring flowrule exists on top of a previously defined chain rule and uses the same vlan tag/routing.
+        :param vnf_src_name:
+        :param vnf_dst_name:
+        :param vnf_src_interface:
+        :param vnf_dst_interface:
+        :param tag: vlan tag to be used for this chain (same tag as existing chain)
+        :param monitor_placement: 'tx' or 'rx' indicating to place the extra flowentry resp. at the beginning or end of the chain
+        :return:
+        """
 
 
+        src_sw = None
+        src_sw_inport_nr = 0
+        src_sw_inport_name = None
+        dst_sw = None
+        dst_sw_outport_nr = 0
+        dst_sw_outport_name = None
 
 
-    def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
+        LOG.debug("call AddMonitorFlow vnf_src_name=%r, vnf_src_interface=%r, vnf_dst_name=%r, vnf_dst_interface=%r",
+                  vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface)
 
 
-        # TODO: this needs to be cleaned up
         #check if port is specified (vnf:port)
         if vnf_src_interface is None:
             # take first interface by default
         #check if port is specified (vnf:port)
         if vnf_src_interface is None:
             # take first interface by default
@@ -262,11 +410,12 @@ class DCNetwork(Containernet):
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
             link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
             for link in link_dict:
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
             link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
             for link in link_dict:
-                if link_dict[link]['src_port_id'] == vnf_src_interface:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
                     # found the right link and connected switch
                     src_sw = connected_sw
                     # found the right link and connected switch
                     src_sw = connected_sw
-
                     src_sw_inport_nr = link_dict[link]['dst_port_nr']
                     src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
                     break
 
         if vnf_dst_interface is None:
                     break
 
         if vnf_dst_interface is None:
@@ -279,12 +428,16 @@ class DCNetwork(Containernet):
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_dst_name):
             link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
             for link in link_dict:
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_dst_name):
             link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
             for link in link_dict:
-                if link_dict[link]['dst_port_id'] == vnf_dst_interface:
+                if link_dict[link]['dst_port_id'] == vnf_dst_interface or \
+                        link_dict[link]['dst_port_name'] == vnf_dst_interface:  # Fix: we might also get interface names, e.g, from a son-emu-cli call
                     # found the right link and connected switch
                     dst_sw = connected_sw
                     dst_sw_outport_nr = link_dict[link]['src_port_nr']
                     # found the right link and connected switch
                     dst_sw = connected_sw
                     dst_sw_outport_nr = link_dict[link]['src_port_nr']
+                    dst_sw_outport_name = link_dict[link]['src_port_name']
                     break
 
                     break
 
+        if not tag >= 0:
+            LOG.exception('tag not valid: {0}'.format(tag))
 
         # get shortest path
         try:
 
         # get shortest path
         try:
@@ -292,21 +445,22 @@ class DCNetwork(Containernet):
             # if all shortest paths are wanted, use: all_shortest_paths
             path = nx.shortest_path(self.DCNetwork_graph, src_sw, dst_sw, weight=kwargs.get('weight'))
         except:
             # if all shortest paths are wanted, use: all_shortest_paths
             path = nx.shortest_path(self.DCNetwork_graph, src_sw, dst_sw, weight=kwargs.get('weight'))
         except:
-            logging.info("No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name))
+            LOG.exception("No path could be found between {0} and {1} using src_sw={2} and dst_sw={3}".format(
+                vnf_src_name, vnf_dst_name, src_sw, dst_sw))
+            LOG.debug("Graph nodes: %r" % self.DCNetwork_graph.nodes())
+            LOG.debug("Graph edges: %r" % self.DCNetwork_graph.edges())
+            for e, v in self.DCNetwork_graph.edges():
+                LOG.debug("%r" % self.DCNetwork_graph[e][v])
             return "No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name)
 
             return "No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name)
 
-        logging.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
+        LOG.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
 
         current_hop = src_sw
         switch_inport_nr = src_sw_inport_nr
 
 
         current_hop = src_sw
         switch_inport_nr = src_sw_inport_nr
 
-        # choose free vlan if path contains more than 1 switch
         cmd = kwargs.get('cmd')
         cmd = kwargs.get('cmd')
-        vlan = None
-        if cmd == 'add-flow':
-            if len(path) > 1:
-                vlan = self.vlans.pop()
 
 
+        #iterate through the path to install the flow-entries
         for i in range(0,len(path)):
             current_node = self.getNodeByName(current_hop)
 
         for i in range(0,len(path)):
             current_node = self.getNodeByName(current_hop)
 
@@ -320,9 +474,9 @@ class DCNetwork(Containernet):
 
             if next_hop == vnf_dst_name:
                 switch_outport_nr = dst_sw_outport_nr
 
             if next_hop == vnf_dst_name:
                 switch_outport_nr = dst_sw_outport_nr
-                logging.info("end node reached: {0}".format(vnf_dst_name))
+                LOG.info("end node reached: {0}".format(vnf_dst_name))
             elif not isinstance( next_node, OVSSwitch ):
             elif not isinstance( next_node, OVSSwitch ):
-                logging.info("Next node: {0} is not a switch".format(next_hop))
+                LOG.info("Next node: {0} is not a switch".format(next_hop))
                 return "Next node: {0} is not a switch".format(next_hop)
             else:
                 # take first link between switches by default
                 return "Next node: {0} is not a switch".format(next_hop)
             else:
                 # take first link between switches by default
@@ -331,10 +485,224 @@ class DCNetwork(Containernet):
 
 
            # set of entry via ovs-ofctl
 
 
            # set of entry via ovs-ofctl
+            if isinstance( current_node, OVSSwitch ):
+                kwargs['vlan'] = tag
+                kwargs['path'] = path
+                kwargs['current_hop'] = current_hop
+                kwargs['switch_inport_name'] = src_sw_inport_name
+                kwargs['switch_outport_name'] = dst_sw_outport_name
+                kwargs['skip_vlan_tag'] = True
+                kwargs['pathindex'] = i
+
+                monitor_placement = kwargs.get('monitor_placement').strip()
+                # put monitor flow at the dst switch
+                insert_flow = False
+                if monitor_placement == 'tx' and path.index(current_hop) == 0:  # first node:
+                    insert_flow = True
+                # put monitoring flow at the src switch
+                elif monitor_placement == 'rx' and path.index(current_hop) == len(path) - 1:  # last node:
+                    insert_flow = True
+                elif monitor_placement not in ['rx', 'tx']:
+                    LOG.exception('invalid monitor command: {0}'.format(monitor_placement))
+
+
+                if self.controller == RemoteController and insert_flow:
+                    ## set flow entry via ryu rest api
+                    self._set_flow_entry_ryu_rest(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
+                    break
+                elif insert_flow:
+                    ## set flow entry via ovs-ofctl
+                    self._set_flow_entry_dpctl(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
+                    break
+
+            # take first link between switches by default
+            if isinstance( next_node, OVSSwitch ):
+                switch_inport_nr = self.DCNetwork_graph[current_hop][next_hop][0]['dst_port_nr']
+                current_hop = next_hop
+
+        return "path {2} between {0} and {1}".format(vnf_src_name, vnf_dst_name, cmd)
+
+
+    def setChain(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
+        """
+        Chain 2 vnf interfaces together by installing the flowrules in the switches along their path.
+        Currently the path is found using the default networkx shortest path function.
+        Each chain gets a unique vlan id , so different chains wil not interfere.
+
+        :param vnf_src_name: vnf name (string)
+        :param vnf_dst_name: vnf name (string)
+        :param vnf_src_interface: source interface name  (string)
+        :param vnf_dst_interface: destination interface name  (string)
+        :param cmd: 'add-flow' (default) to add a chain, 'del-flows' to remove a chain
+        :param cookie: cookie for the installed flowrules (can be used later as identifier for a set of installed chains)
+        :param match: custom match entry to be added to the flowrules (default: only in_port and vlan tag)
+        :param priority: custom flowrule priority
+        :param monitor: boolean to indicate whether this chain is a monitoring chain
+        :param tag: vlan tag to be used for this chain (pre-defined or new one if none is specified)
+        :param skip_vlan_tag: boolean to indicate if a vlan tag should be appointed to this flow or not
+        :param path: custom path between the two VNFs (list of switches)
+        :return: output log string
+        """
+
+        # special procedure for monitoring flows
+        if kwargs.get('monitor'):
+
+            # check if chain already exists
+            found_chains = [chain_dict for chain_dict in self.installed_chains if
+             (chain_dict['vnf_src_name'] == vnf_src_name and chain_dict['vnf_src_interface'] == vnf_src_interface
+             and chain_dict['vnf_dst_name'] == vnf_dst_name and chain_dict['vnf_dst_interface'] == vnf_dst_interface)]
+
+            if len(found_chains) > 0:
+                # this chain exists, so need an extra monitoring flow
+                # assume only 1 chain per vnf/interface pair
+                LOG.debug('*** installing monitoring chain on top of pre-defined chain from {0}:{1} -> {2}:{3}'.
+                            format(vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface))
+                tag = found_chains[0]['tag']
+                ret = self._addMonitorFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface,
+                                     tag=tag, table_id=0, **kwargs)
+                return ret
+            else:
+                # no chain existing (or E-LAN) -> install normal chain
+                LOG.warning('*** installing monitoring chain without pre-defined NSD chain from {0}:{1} -> {2}:{3}'.
+                            format(vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface))
+                pass
+
+
+        cmd = kwargs.get('cmd', 'add-flow')
+        if cmd == 'add-flow' or cmd == 'del-flows':
+            ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
+            if kwargs.get('bidirectional'):
+                if kwargs.get('path') is not None:
+                    kwargs['path'] = list(reversed(kwargs.get('path')))
+                ret = ret +'\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
+
+        else:
+            ret = "Command unknown"
+
+        return ret
+
+
+    def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
+
+        src_sw = None
+        src_sw_inport_nr = 0
+        src_sw_inport_name = None
+        dst_sw = None
+        dst_sw_outport_nr = 0
+        dst_sw_outport_name = None
+
+        LOG.debug("call chainAddFlow vnf_src_name=%r, vnf_src_interface=%r, vnf_dst_name=%r, vnf_dst_interface=%r",
+                  vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface)
+
+        #check if port is specified (vnf:port)
+        if vnf_src_interface is None:
+            # take first interface by default
+            connected_sw = self.DCNetwork_graph.neighbors(vnf_src_name)[0]
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            vnf_src_interface = link_dict[0]['src_port_id']
+
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            for link in link_dict:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    src_sw = connected_sw
+                    src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
+                    break
+
+        if vnf_dst_interface is None:
+            # take first interface by default
+            connected_sw = self.DCNetwork_graph.neighbors(vnf_dst_name)[0]
+            link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
+            vnf_dst_interface = link_dict[0]['dst_port_id']
+
+        vnf_dst_name = vnf_dst_name.split(':')[0]
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_dst_name):
+            link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
+            for link in link_dict:
+                if link_dict[link]['dst_port_id'] == vnf_dst_interface or \
+                        link_dict[link]['dst_port_name'] == vnf_dst_interface:  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    dst_sw = connected_sw
+                    dst_sw_outport_nr = link_dict[link]['src_port_nr']
+                    dst_sw_outport_name = link_dict[link]['src_port_name']
+                    break
+
+        path = kwargs.get('path')
+        if path is None:
+            # get shortest path
+            try:
+                # returns the first found shortest path
+                # if all shortest paths are wanted, use: all_shortest_paths
+                path = nx.shortest_path(self.DCNetwork_graph, src_sw, dst_sw, weight=kwargs.get('weight'))
+            except:
+                LOG.exception("No path could be found between {0} and {1} using src_sw={2} and dst_sw={3}".format(
+                    vnf_src_name, vnf_dst_name, src_sw, dst_sw))
+                LOG.debug("Graph nodes: %r" % self.DCNetwork_graph.nodes())
+                LOG.debug("Graph edges: %r" % self.DCNetwork_graph.edges())
+                for e, v in self.DCNetwork_graph.edges():
+                    LOG.debug("%r" % self.DCNetwork_graph[e][v])
+                return "No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name)
+
+        LOG.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
+
+        current_hop = src_sw
+        switch_inport_nr = src_sw_inport_nr
+
+        # choose free vlan
+        cmd = kwargs.get('cmd')
+        vlan = None
+        if cmd == 'add-flow':
+            if kwargs.get('tag'):
+                # use pre-defined tag
+                vlan = kwargs.get('tag')
+            else:
+                vlan = self.vlans.pop()
+
+        # store the used vlan tag to identify this chain
+        if not kwargs.get('monitor'):
+            chain_dict = {}
+            chain_dict['vnf_src_name'] = vnf_src_name
+            chain_dict['vnf_dst_name'] = vnf_dst_name
+            chain_dict['vnf_src_interface'] = vnf_src_interface
+            chain_dict['vnf_dst_interface'] = vnf_dst_interface
+            chain_dict['tag'] = vlan
+            self.installed_chains.append(chain_dict)
+
+        #iterate through the path to install the flow-entries
+        for i in range(0,len(path)):
+            current_node = self.getNodeByName(current_hop)
+
+            if i < len(path) - 1:
+                next_hop = path[i + 1]
+            else:
+                # last switch reached
+                next_hop = vnf_dst_name
+
+            next_node = self.getNodeByName(next_hop)
+
+            if next_hop == vnf_dst_name:
+                switch_outport_nr = dst_sw_outport_nr
+                LOG.info("end node reached: {0}".format(vnf_dst_name))
+            elif not isinstance( next_node, OVSSwitch ):
+                LOG.info("Next node: {0} is not a switch".format(next_hop))
+                return "Next node: {0} is not a switch".format(next_hop)
+            else:
+                # take first link between switches by default
+                index_edge_out = 0
+                switch_outport_nr = self.DCNetwork_graph[current_hop][next_hop][index_edge_out]['src_port_nr']
+
+
+           # set OpenFlow entry
             if isinstance( current_node, OVSSwitch ):
                 kwargs['vlan'] = vlan
                 kwargs['path'] = path
                 kwargs['current_hop'] = current_hop
             if isinstance( current_node, OVSSwitch ):
                 kwargs['vlan'] = vlan
                 kwargs['path'] = path
                 kwargs['current_hop'] = current_hop
+                kwargs['switch_inport_name'] = src_sw_inport_name
+                kwargs['switch_outport_name'] = dst_sw_outport_name
+                kwargs['pathindex'] = i
 
                 if self.controller == RemoteController:
                     ## set flow entry via ryu rest api
 
                 if self.controller == RemoteController:
                     ## set flow entry via ryu rest api
@@ -343,14 +711,20 @@ class DCNetwork(Containernet):
                     ## set flow entry via ovs-ofctl
                     self._set_flow_entry_dpctl(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
 
                     ## set flow entry via ovs-ofctl
                     self._set_flow_entry_dpctl(current_node, switch_inport_nr, switch_outport_nr, **kwargs)
 
-
-
             # take first link between switches by default
             if isinstance( next_node, OVSSwitch ):
                 switch_inport_nr = self.DCNetwork_graph[current_hop][next_hop][0]['dst_port_nr']
                 current_hop = next_hop
 
             # take first link between switches by default
             if isinstance( next_node, OVSSwitch ):
                 switch_inport_nr = self.DCNetwork_graph[current_hop][next_hop][0]['dst_port_nr']
                 current_hop = next_hop
 
-        return "path {2} between {0} and {1}".format(vnf_src_name, vnf_dst_name, cmd)
+        flow_options = {
+            'priority':kwargs.get('priority', DEFAULT_PRIORITY),
+            'cookie':kwargs.get('cookie', DEFAULT_COOKIE),
+            'vlan':kwargs['vlan'],
+            'path':kwargs['path'],
+            'match_input':kwargs.get('match')
+        }
+        flow_options_str = json.dumps(flow_options, indent=1)
+        return "success: {2} between {0} and {1} with options: {3}".format(vnf_src_name, vnf_dst_name, cmd, flow_options_str)
 
     def _set_flow_entry_ryu_rest(self, node, switch_inport_nr, switch_outport_nr, **kwargs):
         match = 'in_port=%s' % switch_inport_nr
 
     def _set_flow_entry_ryu_rest(self, node, switch_inport_nr, switch_outport_nr, **kwargs):
         match = 'in_port=%s' % switch_inport_nr
@@ -359,8 +733,16 @@ class DCNetwork(Containernet):
         match_input = kwargs.get('match')
         cmd = kwargs.get('cmd')
         path = kwargs.get('path')
         match_input = kwargs.get('match')
         cmd = kwargs.get('cmd')
         path = kwargs.get('path')
-        current_hop = kwargs.get('current_hop')
+        index = kwargs.get('pathindex')
+
         vlan = kwargs.get('vlan')
         vlan = kwargs.get('vlan')
+        priority = kwargs.get('priority', DEFAULT_PRIORITY)
+        # flag to not set the ovs port vlan tag
+        skip_vlan_tag = kwargs.get('skip_vlan_tag')
+        # table id to put this flowentry
+        table_id = kwargs.get('table_id')
+        if not table_id:
+            table_id = 0
 
         s = ','
         if match_input:
 
         s = ','
         if match_input:
@@ -371,7 +753,10 @@ class DCNetwork(Containernet):
 
         if cookie:
             flow['cookie'] = int(cookie)
 
         if cookie:
             flow['cookie'] = int(cookie)
+        if priority:
+            flow['priority'] = int(priority)
 
 
+        flow['table_id'] = table_id
 
         flow['actions'] = []
 
 
         flow['actions'] = []
 
@@ -380,23 +765,39 @@ class DCNetwork(Containernet):
         if cmd == 'add-flow':
             prefix = 'stats/flowentry/add'
             if vlan != None:
         if cmd == 'add-flow':
             prefix = 'stats/flowentry/add'
             if vlan != None:
-                if path.index(current_hop) == 0:  # first node
-                    action = {}
-                    action['type'] = 'PUSH_VLAN'  # Push a new VLAN tag if a input frame is non-VLAN-tagged
-                    action['ethertype'] = 33024   # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
-                    flow['actions'].append(action)
-                    action = {}
-                    action['type'] = 'SET_FIELD'
-                    action['field'] = 'vlan_vid'
-                    action['value'] = vlan
-                    flow['actions'].append(action)
-                elif path.index(current_hop) == len(path) - 1:  # last node
-                    match += ',dl_vlan=%s' % vlan
-                    action = {}
-                    action['type'] = 'POP_VLAN'
-                    flow['actions'].append(action)
+                if index == 0:  # first node
+                    # set vlan tag in ovs instance (to isolate E-LANs)
+                    if not skip_vlan_tag:
+                        in_port_name = kwargs.get('switch_inport_name')
+                        self._set_vlan_tag(node, in_port_name, vlan)
+                    # set vlan push action if more than 1 switch in the path
+                    if len(path) > 1:
+                        action = {}
+                        action['type'] = 'PUSH_VLAN'  # Push a new VLAN tag if a input frame is non-VLAN-tagged
+                        action['ethertype'] = 33024   # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
+                        flow['actions'].append(action)
+                        action = {}
+                        action['type'] = 'SET_FIELD'
+                        action['field'] = 'vlan_vid'
+                        # ryu expects the field to be masked
+                        action['value'] = vlan | 0x1000
+                        flow['actions'].append(action)
+
+                elif index == len(path) - 1:  # last node
+                    # set vlan tag in ovs instance (to isolate E-LANs)
+                    if not skip_vlan_tag:
+                        out_port_name = kwargs.get('switch_outport_name')
+                        self._set_vlan_tag(node, out_port_name, vlan)
+                    # set vlan pop action if more than 1 switch in the path
+                    if len(path) > 1:
+                        match += ',dl_vlan=%s' % vlan
+                        action = {}
+                        action['type'] = 'POP_VLAN'
+                        flow['actions'].append(action)
+
                 else:  # middle nodes
                     match += ',dl_vlan=%s' % vlan
                 else:  # middle nodes
                     match += ',dl_vlan=%s' % vlan
+
             # output action must come last
             action = {}
             action['type'] = 'OUTPUT'
             # output action must come last
             action = {}
             action['type'] = 'OUTPUT'
@@ -418,14 +819,19 @@ class DCNetwork(Containernet):
         flow['match'] = self._parse_match(match)
         self.ryu_REST(prefix, data=flow)
 
         flow['match'] = self._parse_match(match)
         self.ryu_REST(prefix, data=flow)
 
+    def _set_vlan_tag(self, node, switch_port, tag):
+        node.vsctl('set', 'port {0} tag={1}'.format(switch_port,tag))
+        LOG.debug("set vlan in switch: {0} in_port: {1} vlan tag: {2}".format(node.name, switch_port, tag))
+
     def _set_flow_entry_dpctl(self, node, switch_inport_nr, switch_outport_nr, **kwargs):
     def _set_flow_entry_dpctl(self, node, switch_inport_nr, switch_outport_nr, **kwargs):
+
         match = 'in_port=%s' % switch_inport_nr
 
         cookie = kwargs.get('cookie')
         match_input = kwargs.get('match')
         cmd = kwargs.get('cmd')
         path = kwargs.get('path')
         match = 'in_port=%s' % switch_inport_nr
 
         cookie = kwargs.get('cookie')
         match_input = kwargs.get('match')
         cmd = kwargs.get('cmd')
         path = kwargs.get('path')
-        current_hop = kwargs.get('current_hop')
+        index = kwargs.get('pathindex')
         vlan = kwargs.get('vlan')
 
         s = ','
         vlan = kwargs.get('vlan')
 
         s = ','
@@ -437,10 +843,10 @@ class DCNetwork(Containernet):
         if cmd == 'add-flow':
             action = 'action=%s' % switch_outport_nr
             if vlan != None:
         if cmd == 'add-flow':
             action = 'action=%s' % switch_outport_nr
             if vlan != None:
-                if path.index(current_hop) == 0:  # first node
+                if index == 0: # first node
                     action = ('action=mod_vlan_vid:%s' % vlan) + (',output=%s' % switch_outport_nr)
                     match = '-O OpenFlow13 ' + match
                     action = ('action=mod_vlan_vid:%s' % vlan) + (',output=%s' % switch_outport_nr)
                     match = '-O OpenFlow13 ' + match
-                elif path.index(current_hop) == len(path) - 1:  # last node
+                elif index == len(path) - 1:  # last node
                     match += ',dl_vlan=%s' % vlan
                     action = 'action=strip_vlan,output=%s' % switch_outport_nr
                 else:  # middle nodes
                     match += ',dl_vlan=%s' % vlan
                     action = 'action=strip_vlan,output=%s' % switch_outport_nr
                 else:  # middle nodes
@@ -452,14 +858,18 @@ class DCNetwork(Containernet):
             ofcmd = ''
 
         node.dpctl(cmd, ofcmd)
             ofcmd = ''
 
         node.dpctl(cmd, ofcmd)
-        logging.info("{3} in switch: {0} in_port: {1} out_port: {2}".format(node.name, switch_inport_nr,
+        LOG.info("{3} in switch: {0} in_port: {1} out_port: {2}".format(node.name, switch_inport_nr,
                                                                                  switch_outport_nr, cmd))
 
     # start Ryu Openflow controller as Remote Controller for the DCNetwork
     def startRyu(self, learning_switch=True):
         # start Ryu controller with rest-API
         python_install_path = site.getsitepackages()[0]
                                                                                  switch_outport_nr, cmd))
 
     # start Ryu Openflow controller as Remote Controller for the DCNetwork
     def startRyu(self, learning_switch=True):
         # start Ryu controller with rest-API
         python_install_path = site.getsitepackages()[0]
-        ryu_path = python_install_path + '/ryu/app/simple_switch_13.py'
+        # ryu default learning switch
+        #ryu_path = python_install_path + '/ryu/app/simple_switch_13.py'
+        #custom learning switch that installs a default NORMAL action in the ovs switches
+        dir_path = os.path.dirname(os.path.realpath(__file__))
+        ryu_path = dir_path + '/son_emu_simple_switch_13.py'
         ryu_path2 = python_install_path + '/ryu/app/ofctl_rest.py'
         # change the default Openflow controller port to 6653 (official IANA-assigned port number), as used by Mininet
         # Ryu still uses 6633 as default
         ryu_path2 = python_install_path + '/ryu/app/ofctl_rest.py'
         # change the default Openflow controller port to 6653 (official IANA-assigned port number), as used by Mininet
         # Ryu still uses 6633 as default
@@ -469,33 +879,56 @@ class DCNetwork(Containernet):
         FNULL = open("/tmp/ryu.log", 'w')
         if learning_switch:
             self.ryu_process = Popen([ryu_cmd, ryu_path, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         FNULL = open("/tmp/ryu.log", 'w')
         if learning_switch:
             self.ryu_process = Popen([ryu_cmd, ryu_path, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path))
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path2))
         else:
             # no learning switch, but with rest api
             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         else:
             # no learning switch, but with rest api
             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
+            LOG.debug('starting ryu-controller with {0}'.format(ryu_path2))
         time.sleep(1)
 
         time.sleep(1)
 
-    def stopRyu(self):
+    def killRyu(self):
+        """
+        Stop the Ryu controller that might be started by son-emu.
+        :return:
+        """
+        # try it nicely
         if self.ryu_process is not None:
             self.ryu_process.terminate()
             self.ryu_process.kill()
         if self.ryu_process is not None:
             self.ryu_process.terminate()
             self.ryu_process.kill()
+        # ensure its death ;-)
+        Popen(['pkill', '-f', 'ryu-manager'])
 
     def ryu_REST(self, prefix, dpid=None, data=None):
 
     def ryu_REST(self, prefix, dpid=None, data=None):
-        try:
-            if dpid:
-                url = self.ryu_REST_api + '/' + str(prefix) + '/' + str(dpid)
-            else:
-                url = self.ryu_REST_api + '/' + str(prefix)
-            if data:
-                #logging.info('POST: {0}'.format(str(data)))
-                req = urllib2.Request(url, str(data))
-            else:
-                req = urllib2.Request(url)
 
 
-            ret = urllib2.urlopen(req).read()
+        if dpid:
+            url = self.ryu_REST_api + '/' + str(prefix) + '/' + str(dpid)
+        else:
+            url = self.ryu_REST_api + '/' + str(prefix)
+        if data:
+            req = self.RyuSession.post(url, json=data)
+        else:
+            req = self.RyuSession.get(url)
+
+
+        # do extra logging if status code is not 200 (OK)
+        if req.status_code is not requests.codes.ok:
+            logging.info(
+                'type {0}  encoding: {1} text: {2} headers: {3} history: {4}'.format(req.headers['content-type'],
+                                                                                     req.encoding, req.text,
+                                                                                     req.headers, req.history))
+            LOG.info('url: {0}'.format(str(url)))
+            if data: LOG.info('POST: {0}'.format(str(data)))
+            LOG.info('status: {0} reason: {1}'.format(req.status_code, req.reason))
+
+
+        if 'json' in req.headers['content-type']:
+            ret = req.json()
             return ret
             return ret
-        except:
-            logging.info('error url: {0}'.format(str(url)))
-            if data: logging.info('error POST: {0}'.format(str(data)))
+
+        ret = req.text.rstrip()
+        return ret
+
 
     # need to respect that some match fields must be integers
     # http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html#description-of-match-and-actions
 
     # need to respect that some match fields must be integers
     # http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html#description-of-match-and-actions
@@ -513,3 +946,21 @@ class DCNetwork(Containernet):
                 dict.update({match[0]:m2})
         return dict
 
                 dict.update({match[0]:m2})
         return dict
 
+    def find_connected_dc_interface(self, vnf_src_name, vnf_src_interface=None):
+
+        if vnf_src_interface is None:
+            # take first interface by default
+            connected_sw = self.DCNetwork_graph.neighbors(vnf_src_name)[0]
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            vnf_src_interface = link_dict[0]['src_port_id']
+
+        for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
+            link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
+            for link in link_dict:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
+                    # found the right link and connected switch
+                    src_sw = connected_sw
+                    src_sw_inport_nr = link_dict[link]['dst_port_nr']
+                    src_sw_inport_name = link_dict[link]['dst_port_name']
+                    return src_sw_inport_name