Clean up intfs in root NS, and avoid deleting HW intfs

It appears that under certain conditions, such as when a
namespace exits, both ends of a veth pair may get dumped
into the root namespace. We therefore now remove an interface
both from its home namespace and from the root namespace.

mininet/link.py

@@ -25,7 +25,7 @@
 """
 
 from mininet.log import info, error, debug
-from mininet.util import makeIntfPair
+from mininet.util import makeIntfPair, quietRun
 from time import sleep
 import re
 
@@ -162,8 +162,9 @@ def config( self, mac=None, ip=None, ifconfig=None,
     def delete( self ):
         "Delete interface"
         self.cmd( 'ip link del ' + self.name )
-        # Does it help to sleep to let things run?
-        sleep( 0.001 )
+        if self.node.inNamespace:
+            # Link may have been dumped into root NS
+            quietRun( 'ip link del ' + self.name )
 
     def __repr__( self ):
         return '<%s %s>' % ( self.__class__.__name__, self.name )

mininet/net.py

@@ -372,16 +372,16 @@ def stop( self ):
         if self.terms:
             info( '*** Stopping %i terms\n' % len( self.terms ) )
             self.stopXterms()
-        info( '*** Stopping %i hosts\n' % len( self.hosts ) )
-        for host in self.hosts:
-            info( host.name + ' ' )
-            host.terminate()
-        info( '\n' )
         info( '*** Stopping %i switches\n' % len( self.switches ) )
         for switch in self.switches:
             info( switch.name + ' ' )
             switch.stop()
         info( '\n' )
+        info( '*** Stopping %i hosts\n' % len( self.hosts ) )
+        for host in self.hosts:
+            info( host.name + ' ' )
+            host.terminate()
+        info( '\n' )
         info( '*** Stopping %i controllers\n' % len( self.controllers ) )
         for controller in self.controllers:
             info( controller.name + ' ' )

mininet/node.py

@@ -141,10 +141,10 @@ def startShell( self ):
 
     def cleanup( self ):
         "Help python collect its garbage."
-        if not self.inNamespace:
-            for intfName in self.intfNames():
-                if self.name in intfName:
-                    quietRun( 'ip link del ' + intfName )
+        # Intfs may end up in root NS
+        for intfName in self.intfNames():
+            if self.name in intfName:
+                quietRun( 'ip link del ' + intfName )
         self.shell = None
 
     # Subshell I/O, commands and control
@@ -391,16 +391,19 @@ def connectionsTo( self, node):
                     connections += [ ( intf, link.intf1 ) ]
         return connections
 
-    def deleteIntfs( self ):
-        "Delete all of our interfaces."
+    def deleteIntfs( self, checkName=True ):
+        """Delete all of our interfaces.
+           checkName: only delete interfaces that contain our name"""
         # In theory the interfaces should go away after we shut down.
         # However, this takes time, so we're better off removing them
         # explicitly so that we won't get errors if we run before they
         # have been removed by the kernel. Unfortunately this is very slow,
         # at least with Linux kernels before 2.6.33
         for intf in self.intfs.values():
-            intf.delete()
-            info( '.' )
+            # Protect against deleting hardware interfaces
+            if ( self.name in intf.name ) or ( not checkName ):
+                intf.delete()
+                info( '.' )
 
     # Routing support