Merge pull request #353 from mininet/devel/nat

Adding NAT class to NodeLib

examples/natnet.py

@@ -0,0 +1,70 @@
+#!/usr/bin/python
+
+"""
+natnet.py: Example network with NATs
+
+
+           h0
+           |
+           s0
+           |
+    ----------------
+    |              |
+   nat1           nat2
+    |              |
+   s1              s2
+    |              |
+   h1              h2 
+
+"""
+
+from mininet.topo import Topo
+from mininet.net import Mininet
+from mininet.nodelib import NAT
+from mininet.log import setLogLevel
+from mininet.cli import CLI
+from mininet.util import irange
+
+class InternetTopo(Topo):
+    "Single switch connected to n hosts."
+    def __init__(self, n=2, h=1, **opts):
+        Topo.__init__(self, **opts)
+
+        # set up inet switch
+        inetSwitch = self.addSwitch('s0')
+        # add inet host
+        inetHost = self.addHost('h0')
+        self.addLink(inetSwitch, inetHost)
+
+        # add local nets
+        for i in irange(1, n):
+            inetIntf = 'nat%d-eth0' % i
+            localIntf = 'nat%d-eth1' % i
+            localIP = '192.168.%d.1' % i
+            localSubnet = '192.168.%d.0/24' % i
+            natParams = { 'ip' : '%s/24' % localIP }
+            # add NAT to topology
+            nat = self.addNode('nat%d' % i, cls=NAT, subnet=localSubnet, 
+                               inetIntf=inetIntf, localIntf=localIntf)
+            switch = self.addSwitch('s%d' % i)
+            # connect NAT to inet and local switches
+            self.addLink(nat, inetSwitch, intfName1=inetIntf)
+            self.addLink(nat, switch, intfName1=localIntf, params1=natParams)
+            # add host and connect to local switch
+            host = self.addHost('h%d' % i, 
+                                ip='192.168.%d.100/24' % i, 
+                                defaultRoute='via %s' % localIP)
+            self.addLink(host, switch)
+
+def run():
+    "Create network and run the CLI"
+    topo = InternetTopo()
+    net = Mininet(topo=topo)
+    net.start()
+    CLI(net)
+    net.stop()
+
+if __name__ == '__main__':
+    setLogLevel('info')
+    run()
+    

examples/test/test_natnet.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+
+"""
+Test for natnet.py
+"""
+
+import unittest
+import pexpect
+from mininet.util import quietRun
+
+class testNATNet( unittest.TestCase ):
+
+    prompt = 'mininet>'
+
+    def setUp( self ):
+        self.net = pexpect.spawn( 'python -m mininet.examples.natnet' )
+        self.net.expect( self.prompt )
+
+    def testPublicPing( self ):
+        "Attempt to ping the public server (h0) from h1 and h2"
+        self.net.sendline( 'h1 ping -c 1 h0' )
+        self.net.expect ( '(\d+)% packet loss' )
+        percent = int( self.net.match.group( 1 ) ) if self.net.match else -1
+        self.assertEqual( percent, 0 )
+        self.net.expect( self.prompt )
+
+        self.net.sendline( 'h2 ping -c 1 h0' )
+        self.net.expect ( '(\d+)% packet loss' )
+        percent = int( self.net.match.group( 1 ) ) if self.net.match else -1
+        self.assertEqual( percent, 0 )
+        self.net.expect( self.prompt )
+
+    def testPrivatePing( self ):
+        "Attempt to ping h1 and h2 from public server"
+        self.net.sendline( 'h0 ping -c 1 -t 1 h1' )
+        result = self.net.expect ( [ 'unreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+        self.net.sendline( 'h0 ping -c 1 -t 1 h2' )
+        result = self.net.expect ( [ 'unreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+    def testPrivateToPrivatePing( self ):
+        "Attempt to ping from NAT'ed host h1 to NAT'ed host h2"
+        self.net.sendline( 'h1 ping -c 1 -t 1 h2' )
+        result = self.net.expect ( [ '[Uu]nreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+    def tearDown( self ):
+        self.net.sendline( 'exit' )
+        self.net.wait()
+
+if __name__ == '__main__':
+    unittest.main()