Added TorusTopo, a 2D torus topology

bin/mn

@@ -30,7 +30,7 @@ from mininet.node import ( Host, CPULimitedHost, Controller, OVSController,
 from mininet.nodelib import LinuxBridge
 from mininet.link import Link, TCLink
 from mininet.topo import SingleSwitchTopo, LinearTopo, SingleSwitchReversedTopo
-from mininet.topolib import TreeTopo
+from mininet.topolib import TreeTopo, TorusTopo
 from mininet.util import custom, customConstructor
 from mininet.util import buildTopo
 
@@ -41,7 +41,8 @@ TOPOS = { 'minimal': lambda: SingleSwitchTopo( k=2 ),
           'linear': LinearTopo,
           'reversed': SingleSwitchReversedTopo,
           'single': SingleSwitchTopo,
-          'tree': TreeTopo }
+          'tree': TreeTopo,
+          'torus': TorusTopo }
 
 SWITCHDEF = 'ovsk'
 SWITCHES = { 'user': UserSwitch,

mininet/topolib.py

@@ -34,3 +34,37 @@ def TreeNet( depth=1, fanout=2, **kwargs ):
     "Convenience function for creating tree networks."
     topo = TreeTopo( depth, fanout )
     return Mininet( topo, **kwargs )
+
+
+class TorusTopo( Topo ):
+    """2-D Torus topology
+       WARNING: this topology has LOOPS and WILL NOT WORK
+       with the default controller or any Ethernet bridge
+       without STP turned on! It can be used with STP, e.g.:
+       # mn --topo torus,3,3 --switch lxbr,stp=1 --test pingall"""
+    def __init__( self, x, y, *args, **kwargs ):
+        Topo.__init__( self, *args, **kwargs )
+        if x < 3 or y < 3:
+            raise Exception( 'Please use 3x3 or greater for compatibility '
+                            'with Mininet 2.1.0' )
+        hosts, switches, dpid = {}, {}, 0
+        # Create and wire interior
+        for i in range( 0, x ):
+            for j in range( 0, y ):
+                loc = '%dx%d' % ( i + 1, j + 1 )
+                # dpid cannot be zero for OVS
+                dpid = ( i + 1 ) * 256 + ( j + 1 )
+                switch = switches[ i, j ] = self.addSwitch( 's' + loc, dpid='%016x' % dpid )
+                host = hosts[ i, j ] = self.addHost( 'h' + loc )
+                self.addLink( host, switch )
+        # Connect switches
+        for i in range( 0, x ):
+            for j in range( 0, y ):
+                sw1 = switches[ i, j ]
+                sw2 = switches[ i, ( j + 1 ) % y ]
+                sw3 = switches[ ( i + 1 ) % x, j ]
+                self.addLink( sw1, sw2 )
+                self.addLink( sw1, sw3 )
+
+    
+