allow custom paths for chaining

[osm/vim-emu.git] / src / emuvim / dcemulator / net.py

diff --git a/src/emuvim/dcemulator/net.py b/src/emuvim/dcemulator/net.py
index 3556535..faf758c 100755 (executable)
--- a/src/emuvim/dcemulator/net.py
+++ b/src/emuvim/dcemulator/net.py
@@ -1,26 +1,51 @@
 """
 """

-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

 
 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
 from emuvim.dcemulator.node import Datacenter, EmulatorCompute
 from emuvim.dcemulator.resourcemodel import ResourceModelRegistrar
 
 import networkx as nx
 from emuvim.dcemulator.monitoring import DCNetworkMonitor
 from emuvim.dcemulator.node import Datacenter, EmulatorCompute
 from emuvim.dcemulator.resourcemodel import ResourceModelRegistrar
 

+LOG = logging.getLogger("dcemulator.net")
+LOG.setLevel(logging.DEBUG)
+

 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides
 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides


@@ -40,15 +65,19 @@ 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
+
+        # 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)
 

-

         # Ryu management
         # Ryu management

-        self.ryu_process = None

         if controller == RemoteController:
             # start Ryu controller
             self.startRyu(learning_switch=enable_learning)
         if controller == RemoteController:
             # start Ryu controller
             self.startRyu(learning_switch=enable_learning)


@@ -63,9 +92,10 @@ class DCNetwork(Containernet):
         self.vlans = range(4096)[::-1]
 
         # link to Ryu REST_API
         self.vlans = range(4096)[::-1]
 
         # 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:


@@ -87,7 +117,7 @@ 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 +127,7 @@ 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)))
+        LOG.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:


@@ -224,32 +254,60 @@ 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):
     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 path: custom path between the two VNFs (list of switches)
+        :return: output log string
+        """

         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'):
         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'):

-                return ret +'\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
+                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)

 
 

-        elif cmd == 'del-flows':  # TODO: del-flow to be implemented
+        elif cmd == 'del-flows':

             ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
             if kwargs.get('bidirectional'):
             ret = self._chainAddFlow(vnf_src_name, vnf_dst_name, vnf_src_interface, vnf_dst_interface, **kwargs)
             if kwargs.get('bidirectional'):

-                return ret + '\n' + self._chainAddFlow(vnf_dst_name, vnf_src_name, vnf_dst_interface, vnf_src_interface, **kwargs)
+                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:
 
         else:

-            return "Command unknown"
+            ret = "Command unknown"
+
+        return ret

 
 
     def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
 
 
 
     def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
 

-        # TODO: this needs to be cleaned up
+        src_sw = None
+        dst_sw = None
+        src_sw_inport_nr = 0
+        dst_sw_outport_nr = 0
+
+        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
         #check if port is specified (vnf:port)
         if vnf_src_interface is None:
             # take first interface by default


@@ -260,10 +318,10 @@ 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']
                     break
 
                     src_sw_inport_nr = link_dict[link]['dst_port_nr']
                     break
 


@@ -277,23 +335,30 @@ 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']
                     break
 
                     # found the right link and connected switch
                     dst_sw = connected_sw
                     dst_sw_outport_nr = link_dict[link]['src_port_nr']
                     break
 

-
-        # 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:
-            logging.info("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))
+        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
 
         current_hop = src_sw
         switch_inport_nr = src_sw_inport_nr


@@ -308,19 +373,19 @@ class DCNetwork(Containernet):
         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)
 

-            if path.index(current_hop) < len(path)-1:
-                next_hop = path[path.index(current_hop)+1]
+            if i < len(path) - 1:
+                next_hop = path[i + 1]

             else:
             else:

-                #last switch reached
+                # 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
                 next_hop = vnf_dst_name
 
             next_node = self.getNodeByName(next_hop)
 
             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


@@ -332,7 +397,7 @@ class DCNetwork(Containernet):
             if isinstance( current_node, OVSSwitch ):
                 kwargs['vlan'] = vlan
                 kwargs['path'] = path
             if isinstance( current_node, OVSSwitch ):
                 kwargs['vlan'] = vlan
                 kwargs['path'] = path

-                kwargs['current_hop'] = current_hop
+                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


@@ -357,8 +422,10 @@ 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')

 
         s = ','
         if match_input:
 
         s = ','
         if match_input:


@@ -369,7 +436,8 @@ class DCNetwork(Containernet):
 
         if cookie:
             flow['cookie'] = int(cookie)
 
         if cookie:
             flow['cookie'] = int(cookie)

-
+        if priority:
+            flow['priority'] = int(priority)

 
         flow['actions'] = []
 
 
         flow['actions'] = []
 


@@ -378,7 +446,7 @@ 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
+                if index == 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
                     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


@@ -386,9 +454,10 @@ class DCNetwork(Containernet):
                     action = {}
                     action['type'] = 'SET_FIELD'
                     action['field'] = 'vlan_vid'
                     action = {}
                     action['type'] = 'SET_FIELD'
                     action['field'] = 'vlan_vid'

-                    action['value'] = vlan
+                    # ryu expects the field to be masked
+                    action['value'] = vlan | 0x1000

                     flow['actions'].append(action)
                     flow['actions'].append(action)

-                elif path.index(current_hop) == len(path) - 1:  # last node
+                elif index == len(path) -1:  # last node

                     match += ',dl_vlan=%s' % vlan
                     action = {}
                     action['type'] = 'POP_VLAN'
                     match += ',dl_vlan=%s' % vlan
                     action = {}
                     action['type'] = 'POP_VLAN'


@@ -404,9 +473,8 @@ class DCNetwork(Containernet):
         elif cmd == 'del-flows':
             prefix = 'stats/flowentry/delete'
 
         elif cmd == 'del-flows':
             prefix = 'stats/flowentry/delete'
 

-            # if cookie is given, only delete flows by cookie
-            # do not specify other match -> also other cookies can be matched

             if cookie:
             if cookie:

+                # TODO: add cookie_mask as argument

                 flow['cookie_mask'] = int('0xffffffffffffffff', 16)  # need full mask to match complete cookie
 
             action = {}
                 flow['cookie_mask'] = int('0xffffffffffffffff', 16)  # need full mask to match complete cookie
 
             action = {}


@@ -424,7 +492,7 @@ 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')
 
         s = ','
         vlan = kwargs.get('vlan')
 
         s = ','


@@ -436,10 +504,10 @@ 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


@@ -451,7 +519,7 @@ 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
                                                                                  switch_outport_nr, cmd))
 
     # start Ryu Openflow controller as Remote Controller for the DCNetwork


@@ -469,33 +537,52 @@ class DCNetwork(Containernet):
         if learning_switch:
             self.ryu_process = Popen([ryu_cmd, ryu_path, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         else:
         if learning_switch:
             self.ryu_process = Popen([ryu_cmd, ryu_path, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         else:

-            # no learning switch
+            # no learning switch, but with rest api

             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         time.sleep(1)
 
             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         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):

-        if data: logging.info('log POST: {0}'.format(str(data)))
-        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