use isinstance( intf, OVSIntf )

Unfortunately disabling IPv6 via sysctl doesn't actually
disable it on all of the interfaces by default. Disabling
it via grub disables it entirely in the VM.

Helps with #454

bin/mn

@@ -30,7 +30,7 @@ from mininet.node import ( Host, CPULimitedHost, Controller, OVSController,
                            UserSwitch, OVSSwitch, OVSBridge,
                            OVSLegacyKernelSwitch, IVSSwitch )
 from mininet.nodelib import LinuxBridge
-from mininet.link import Link, TCLink
+from mininet.link import Link, TCLink, OVSLink
 from mininet.topo import SingleSwitchTopo, LinearTopo, SingleSwitchReversedTopo
 from mininet.topolib import TreeTopo, TorusTopo
 from mininet.util import customConstructor, splitArgs
@@ -82,7 +82,8 @@ CONTROLLERS = { 'ref': Controller,
 
 LINKDEF = 'default'
 LINKS = { 'default': Link,
-          'tc': TCLink }
+          'tc': TCLink,
+          'ovs': OVSLink }
 
 
 # optional tests to run

examples/clustercli.py

@@ -30,12 +30,14 @@ class ClusterCLI( CLI ):
         global nx, plt
         if not nx:
             try:
+                # pylint: disable=import-error
                 import networkx
                 nx = networkx  # satisfy pylint
                 from matplotlib import pyplot
                 plt = pyplot   # satisfiy pylint
                 import pygraphviz
                 assert pygraphviz  # silence pyflakes
+                # pylint: enable=import-error
             except ImportError:
                 error( 'plot requires networkx, matplotlib and pygraphviz - '
                        'please install them and try again\n' )

mininet/link.py

@@ -26,6 +26,7 @@ Link: basic link class for creating veth pairs
 
 from mininet.log import info, error, debug
 from mininet.util import makeIntfPair, quietRun
+import mininet.node
 import re
 
 class Intf( object ):
@@ -453,6 +454,38 @@ class Link( object ):
     def __str__( self ):
         return '%s<->%s' % ( self.intf1, self.intf2 )
 
+
+class OVSIntf( Intf ):
+    "Patch interface on an OVSSwitch"
+
+    def ifconfig( self, cmd ):
+        if cmd == 'up':
+            "OVSIntf is always up"
+            return
+        else:
+            raise Exception( 'OVSIntf cannot do ifconfig ' + cmd )
+
+
+class OVSLink( Link ):
+    "Link that makes patch links between OVSSwitches"
+
+    def __init__( self, node1, node2, **kwargs ):
+        "See Link.__init__() for options"
+        self.isPatchLink = False
+        if ( type( node1 ) is mininet.node.OVSSwitch and
+             type( node2 ) is mininet.node.OVSSwitch ):
+             self.isPatchLink = True
+             kwargs.update( cls1=OVSIntf, cls2=OVSIntf )
+        Link.__init__( self, node1, node2, **kwargs )
+
+    def makeIntfPair( self, *args, **kwargs ):
+        "Usually delegated to OVSSwitch"
+        if self.isPatchLink:
+            return None, None
+        else:
+            return Link.makeIntfPair( *args, **kwargs )
+
+
 class TCLink( Link ):
     "Link with symmetric TC interfaces configured via opts"
     def __init__( self, node1, node2, port1=None, port2=None,

mininet/node.py

@@ -52,14 +52,13 @@ import re
 import signal
 import select
 from subprocess import Popen, PIPE
-from operator import or_
 from time import sleep
 
 from mininet.log import info, error, warn, debug
 from mininet.util import ( quietRun, errRun, errFail, moveIntf, isShellBuiltin,
                            numCores, retry, mountCgroups )
 from mininet.moduledeps import moduleDeps, pathCheck, OVS_KMOD, OF_KMOD, TUN
-from mininet.link import Link, Intf, TCIntf
+from mininet.link import Link, Intf, TCIntf, OVSIntf
 from re import findall
 from distutils.version import StrictVersion
 
@@ -1066,6 +1065,7 @@ class OVSSwitch( Switch ):
         self.datapath = datapath
         self.inband = inband
         self.protocols = protocols
+        self._uuids = []  # controller UUIDs
 
     @classmethod
     def setup( cls ):
@@ -1124,22 +1124,38 @@ class OVSSwitch( Switch ):
         "Disconnect a data port"
         self.cmd( 'ovs-vsctl del-port', self, intf )
 
-    def controllerUUIDs( self ):
-        "Return ovsdb UUIDs for our controllers"
-        uuids = []
-        controllers = self.cmd( 'ovs-vsctl -- get Bridge', self,
-                                'Controller' ).strip()
-        if controllers.startswith( '[' ) and controllers.endswith( ']' ):
-            controllers = controllers[ 1 : -1 ]
-            uuids = [ c.strip() for c in controllers.split( ',' ) ]
-        return uuids
+    def controllerUUIDs( self, update=False ):
+        """Return ovsdb UUIDs for our controllers
+           update: update cached value"""
+        if not self._uuids or update:
+            controllers = self.cmd( 'ovs-vsctl -- get Bridge', self,
+                                    'Controller' ).strip()
+            if controllers.startswith( '[' ) and controllers.endswith( ']' ):
+                controllers = controllers[ 1 : -1 ]
+                if controllers:
+                    self._uuids = [ c.strip()
+                                    for c in controllers.split( ',' ) ]
+        return self._uuids
 
     def connected( self ):
         "Are we connected to at least one of our controllers?"
-        results = [ 'true' in self.cmd( 'ovs-vsctl -- get Controller',
-                                        uuid, 'is_connected' )
-                    for uuid in self.controllerUUIDs() ]
-        return reduce( or_, results, False )
+        for uuid in self.controllerUUIDs():
+            if 'true' in self.cmd( 'ovs-vsctl -- get Controller',
+                                            uuid, 'is_connected' ):
+                return True
+        return self.failMode == 'standalone'
+
+    @staticmethod
+    def patchOpts( intf ):
+        "Return OVS patch port options (if any) for intf"
+        if not isinstance( intf, OVSIntf ):
+            # Ignore if it's not a patch link
+            return ''
+        intf1, intf2 = intf.link.intf1, intf.link.intf2
+        peer = intf1 if intf1 != intf else intf2
+        return ( '-- set Interface %s type=patch '
+                 '-- set Interface %s options:peer=%s ' %
+                 ( intf, intf, peer ) )
 
     def start( self, controllers ):
         "Start up a new OVS OpenFlow switch using ovs-vsctl"
@@ -1153,6 +1169,7 @@ class OVSSwitch( Switch ):
         intfs = ' '.join( '-- add-port %s %s ' % ( self, intf ) +
                           '-- set Interface %s ' % intf +
                           'ofport_request=%s ' % self.ports[ intf ]
+                          + self.patchOpts( intf )
                           for intf in self.intfList()
                           if self.ports[ intf ] and not intf.IP() )
         clist = ' '.join( '%s:%s:%d' % ( c.protocol, c.IP(), c.port )
@@ -1184,15 +1201,14 @@ class OVSSwitch( Switch ):
             cmd += '-- set bridge %s datapath_type=netdev ' % self
         if self.protocols:
             cmd += '-- set bridge %s protocols=%s' % ( self, self.protocols )
-        # Reconnect quickly to controllers (1s vs. 15s max_backoff)
-        for uuid in self.controllerUUIDs():
-            if uuid.count( '-' ) != 4:
-                # Doesn't look like a UUID
-                continue
-            uuid = uuid.strip()
-            cmd += '-- set Controller %smax_backoff=1000 ' % uuid
         # Do it!!
         self.cmd( cmd )
+        # Reconnect quickly to controllers (1s vs. 15s max_backoff)
+        uuids = [ '-- set Controller %s max_backoff=1000' % uuid
+                  for uuid in self.controllerUUIDs() ]
+        if uuids:
+            self.cmd( 'ovs-vsctl', *uuids )
+        # If necessary, restore TC config overwritten by OVS
         for intf in self.intfList():
             self.TCReapply( intf )
 

util/install.sh

@@ -554,9 +554,9 @@ function vm_other {
     #    BLACKLIST=/etc/modprobe.d/blacklist
     #fi
     #sudo sh -c "echo 'blacklist net-pf-10\nblacklist ipv6' >> $BLACKLIST"
-
+    echo "Disabling IPv6"
     # Disable IPv6
-    if ! grep 'disable IPv6' /etc/sysctl.conf; then
+    if ! grep 'disable_ipv6' /etc/sysctl.conf; then
         echo 'Disabling IPv6'
         echo '
 # Mininet: disable IPv6
@@ -564,6 +564,13 @@ net.ipv6.conf.all.disable_ipv6 = 1
 net.ipv6.conf.default.disable_ipv6 = 1
 net.ipv6.conf.lo.disable_ipv6 = 1' | sudo tee -a /etc/sysctl.conf > /dev/null
     fi
+    # Since the above doesn't disable neighbor discovery, also do this:
+    if ! grep 'ipv6.disable' /etc/default/grub; then
+        sudo sed -i -e \
+        's/GRUB_CMDLINE_LINUX_DEFAULT="/GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1/' \
+        /etc/default/grub
+        sudo update-grub
+    fi
     # Disabling IPv6 breaks X11 forwarding via ssh
     line='AddressFamily inet'
     file='/etc/ssh/sshd_config'

util/vm/install-mininet-vm.sh

@@ -11,7 +11,8 @@ sudo sed -i -e 's/Default/#Default/' /etc/sudoers
 echo mininet-vm | sudo tee /etc/hostname > /dev/null
 sudo sed -i -e 's/ubuntu/mininet-vm/g' /etc/hosts
 sudo hostname `cat /etc/hostname`
-sudo sed -i -e 's/quiet splash/text/' /etc/default/grub
+sudo sed -i -e 's/splash//' /etc/default/grub
+sudo sed -i -e 's/quiet/text/' /etc/default/grub
 sudo update-grub
 # Update from official archive
 sudo apt-get update