python: cleanup

python/tools/virtual_network_builder.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+# Copyright (C) 2015 Savoir-Faire Linux Inc.
+# Author: Adrien Béraud <adrien.beraud@savoirfairelinux.com>
+
+import argparse, subprocess
+
+from pyroute2 import IPDB, NetNS
+from pyroute2.netns.process.proxy import NSPopen
+
+parser = argparse.ArgumentParser(description='Creates a virtual network topology for testing')
+parser.add_argument('-i', '--ifname', help='interface name', default='ethdht')
+parser.add_argument('-n', '--ifnum', type=int, help='number of isolated interfaces to create', default=1)
+parser.add_argument('-r', '--remove', help='remove instead of adding network interfaces', action="store_true")
+parser.add_argument('-l', '--loss', help='simulated packet loss (percent)', type=int, default=0)
+parser.add_argument('-d', '--delay', help='simulated latency (ms)', type=int, default=0)
+parser.add_argument('-4', '--ipv4', help='Enable IPv4', action="store_true")
+parser.add_argument('-6', '--ipv6', help='Enable IPv6', action="store_true")
+
+args = parser.parse_args()
+
+local_addr4 = '10.0.42.'
+local_addr6 = '2001:db9::'
+brige_name = 'br'+args.ifname
+
+ip = None
+try:
+    ip = IPDB()
+    if args.remove:
+        # cleanup interfaces
+        for ifn in range(args.ifnum):
+            iface = args.ifname+str(ifn)
+            if iface in ip.interfaces:
+                with ip.interfaces[iface] as i:
+                    i.remove()
+        if 'tap'+args.ifname in ip.interfaces:
+            with ip.interfaces['tap'+args.ifname] as i:
+                i.remove()
+        if brige_name in ip.interfaces:
+            with ip.interfaces[brige_name] as i:
+                i.remove()
+        for ifn in range(args.ifnum):
+            netns = NetNS('node'+str(ifn))
+            netns.close()
+            netns.remove()
+    else:
+        for ifn in range(args.ifnum):
+            iface = args.ifname+str(ifn)
+            if not iface in ip.interfaces:
+                ip.create(kind='veth', ifname=iface, peer=iface+'.1').commit()
+
+        ip.create(kind='tuntap', ifname='tap'+args.ifname, mode='tap').commit()
+
+        with ip.create(kind='bridge', ifname=brige_name) as i:
+            for ifn in range(args.ifnum):
+                iface = args.ifname+str(ifn)
+                i.add_port(ip.interfaces[iface])
+            i.add_port(ip.interfaces['tap'+args.ifname])
+            if args.ipv4:
+                i.add_ip(local_addr4+'1/24')
+            if args.ipv6:
+                i.add_ip(local_addr6+'1/64')
+            i.up()
+
+        with ip.interfaces['tap'+args.ifname] as tap:
+            tap.up()
+
+        for ifn in range(args.ifnum):
+            iface = args.ifname+str(ifn)
+
+            nns = NetNS('node'+str(ifn))
+            iface1 = iface+'.1'
+            with ip.interfaces[iface1] as i:
+                i.net_ns_fd = nns.netns
+
+            with ip.interfaces[iface] as i:
+                i.up()
+
+            ip_ns = IPDB(nl=nns)
+            try:
+                with ip_ns.interfaces.lo as lo:
+                    lo.up()
+                with ip_ns.interfaces[iface1] as i:
+                    if args.ipv4:
+                        i.add_ip(local_addr4+str(ifn+8)+'/24')
+                    if args.ipv6:
+                        i.add_ip(local_addr6+str(ifn+8)+'/64')
+                    i.up()
+            finally:
+                ip_ns.release()
+
+            nsp = NSPopen(nns.netns, ["tc", "qdisc", "add", "dev", iface1, "root", "netem", "delay", str(args.delay)+"ms", str(int(args.delay/2))+"ms", "loss", str(args.loss)+"%", "25%"], stdout=subprocess.PIPE)
+            #print(nsp.communicate()[0].decode())
+            nsp.communicate()
+            nsp.wait()
+            nsp.release()
+
+        if args.ipv4:
+            subprocess.call(["sysctl", "-w", "net.ipv4.conf."+brige_name+".forwarding=1"])
+        if args.ipv6:
+            subprocess.call(["sysctl", "-w", "net.ipv6.conf."+brige_name+".forwarding=1"])
+
+except Exception as e:
+      print('Error',e)
+finally:
+    if ip:
+        ip.release()