From 76521ef1d4fbf114ca65cdbeb4fe5b16eda777c9 Mon Sep 17 00:00:00 2001
From: Bob Lantz <rlantz@cs.stanford.edu>
Date: Mon, 25 Oct 2010 21:53:29 -0700
Subject: [PATCH] Added example of adding hw interface to mininet.

---
 examples/hwintf.py | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100755 examples/hwintf.py

diff --git a/examples/hwintf.py b/examples/hwintf.py
new file mode 100755
index 0000000..d824729
--- /dev/null
+++ b/examples/hwintf.py
@@ -0,0 +1,43 @@
+#!/usr/bin/python
+
+"""
+This example shows how to add an interface (for example a real
+hardware interface) to a network after the network is created.
+"""
+
+import re
+
+from mininet.cli import CLI
+from mininet.log import setLogLevel, info, error
+from mininet.net import Mininet
+from mininet.topolib import TreeTopo
+from mininet.util import quietRun
+
+def checkIntf( intf ):
+    "Make sure intf exists and is not configured."
+    if ( ' %s:' % intf ) not in quietRun( 'ip link show' ):
+        error( 'Error:', intf, 'does not exist!\n' )
+        exit( 1 )
+    ips = re.findall( r'\d+\.\d+\.\d+\.\d+', quietRun( 'ifconfig ' + intf ) )
+    if ips:
+        error( 'Error:', intf, 'has an IP address,'
+            'and is probably in use!\n' )
+        exit( 1 )
+
+if __name__ == '__main__':
+    setLogLevel( 'info' )
+
+    newIntf = 'veth1'
+    info( '*** Checking', newIntf, '\n' )
+    checkIntf( newIntf )
+
+    info( '*** Creating network\n' )
+    net = Mininet( topo=TreeTopo( depth=1, fanout=2 ) )
+
+    switch = net.switches[ 0 ]
+    info( '*** Adding', newIntf, 'to switch', switch.name, '\n' )
+    switch.addIntf( newIntf )
+
+    net.start()
+    CLI( net )
+    net.stop()