1 files changed, 96 insertions, 0 deletions
diff --git a/sflow-rt/extras/sflow.py b/sflow-rt/extras/sflow.py
new file mode 100644
index 0000000..4941093
--- /dev/null
+++ b/sflow-rt/extras/sflow.py
@@ -0,0 +1,96 @@
+from mininet.net import Mininet
+from mininet.util import quietRun
+from requests import put
+from os import listdir, environ
+import re
+import socket
+import fcntl
+import array
+import struct
+import sys
+
+def wrapper(fn):
+
+  def getIfInfo(dst):
+    is_64bits = sys.maxsize > 2**32
+    struct_size = 40 if is_64bits else 32
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    max_possible = 8 # initial value
+    while True:
+      bytes = max_possible * struct_size
+      names = array.array('B')
+      for i in range(0, bytes):
+        names.append(0)
+      outbytes = struct.unpack('iL', fcntl.ioctl(
+        s.fileno(),
+        0x8912,  # SIOCGIFCONF
+        struct.pack('iL', bytes, names.buffer_info()[0])
+      ))[0]
+      if outbytes == bytes:
+        max_possible *= 2
+      else:
+        break
+    try: 
+      namestr = names.tobytes()
+      namestr = namestr.decode('utf-8')
+    except AttributeError:
+      namestr = names.tostring()
+    s.connect((dst, 0))
+    ip = s.getsockname()[0]
+    for i in range(0, outbytes, struct_size):
+      name = namestr[i:i+16].split('\0', 1)[0]
+      addr = socket.inet_ntoa(namestr[i+20:i+24].encode('utf-8'))
+      if addr == ip:
+        return (name,addr)
+
+  def configSFlow(net,collector,ifname,sampling,polling):
+    print("*** Enabling sFlow:")
+    sflow = 'ovs-vsctl -- --id=@sflow create sflow agent=%s target=%s sampling=%s polling=%s --' % (ifname,collector,sampling,polling)
+    for s in net.switches:
+      sflow += ' -- set bridge %s sflow=@sflow' % s
+    print(' '.join([s.name for s in net.switches]))
+    quietRun(sflow)
+
+  def sendTopology(net,agent,collector):
+    print("*** Sending topology")
+    topo = {'nodes':{}, 'links':{}}
+    for s in net.switches:
+      topo['nodes'][s.name] = {'agent':agent, 'ports':{}}
+    path = '/sys/devices/virtual/net/'
+    for child in listdir(path):
+      parts = re.match('(^.+)-(.+)', child)
+      if parts == None: continue
+      if parts.group(1) in topo['nodes']:
+        ifindex = open(path+child+'/ifindex').read().split('\n',1)[0]
+        topo['nodes'][parts.group(1)]['ports'][child] = {'ifindex': ifindex}
+    i = 0
+    for s1 in net.switches:
+      j = 0
+      for s2 in net.switches:
+        if j > i:
+          intfs = s1.connectionsTo(s2)
+          for intf in intfs:
+            s1ifIdx = topo['nodes'][s1.name]['ports'][intf[0].name]['ifindex']
+            s2ifIdx = topo['nodes'][s2.name]['ports'][intf[1].name]['ifindex']
+            linkName = '%s-%s' % (s1.name, s2.name)
+            topo['links'][linkName] = {'node1': s1.name, 'port1': intf[0].name, 'node2': s2.name, 'port2': intf[1].name}
+        j += 1
+      i += 1
+
+    put('http://%s:8008/topology/json' % collector, json=topo)
+
+  def result(*args,**kwargs):
+    res = fn(*args,**kwargs)
+    net = args[0]
+    collector = environ.get('COLLECTOR','127.0.0.1')
+    sampling = environ.get('SAMPLING','10')
+    polling = environ.get('POLLING','10')
+    (ifname, agent) = getIfInfo(collector)
+    configSFlow(net,collector,ifname,sampling,polling)
+    sendTopology(net,agent,collector) 
+    return res
+
+  return result
+
+setattr(Mininet, 'start', wrapper(Mininet.__dict__['start']))
+