def restoresnmpiface(self): """ bind to an SNMP interface """ from snmpiface import SnmpIface self.snmpiface = SnmpIface(host=self.host) return self
class RouterSnmp(Router):
""" an extension for the Router data structure which binds a router object to an SNMP interface to this router """
def __init__(self,ip):
super(RouterSnmp,self).__init__(ip)
self.restoresnmpiface() # create an SNMP interface
def merge(self,router):
""" copy the information from the passed object to self """
if self.host == router.host:
self.name = router.name
self.ips = router.ips
self.neighbours = router.neighbours
self.num_ifs = router.num_ifs
self.interfaces = router.interfaces
def cleartopickle(self):
""" return Router data structure without SNMP interface """
del self.snmpiface
return self
def restoresnmpiface(self):
""" bind to an SNMP interface """
from snmpiface import SnmpIface
self.snmpiface = SnmpIface(host=self.host)
return self
def getTopologyInfo(self):
""" query the router for the topology-related information """
for i in range(10):
try:
self.neighbours = self.snmpiface.getSubtree(self.snmpiface.oid_ipRouteNextHop).values() # all the routing table Next-Hop values
self.ips = self.snmpiface.getSubtree(self.snmpiface.oid_ipAdEntAddr).values()
self.neighbours = list(set(self.neighbours).difference(self.ips)) # neighbours are only those which do not belong to the router itself
i=0
break
except Exception:
pass
if i>0:
raise Exception("Router did not respond for 10 retries")
def getNumIfs(self):
""" get the number of network interfaces """
try:
self.num_ifs = int(self.snmpiface.getObject(self.snmpiface.oid_ifNumber))
except Exception:
raise
def getInfo(self):
""" get the configuration information of the router """
for i in range(10):
try:
self.name = self.snmpiface.getObject(self.snmpiface.oid_sysName)
self.getNumIfs()
self.interfaces = self.snmpiface.getBulk(self.snmpiface.oid_ifDescr,self.num_ifs).values()
i=0
break
except Exception:
pass
if i>0:
raise Exception("Router did not respond for 10 retries")
def pollLinksLoad(self):
""" poll the router for the link states and compute the total router state """
try:
currLinksLoad=self.snmpiface.getBulk(self.snmpiface.oid_ifInOctets,self.num_ifs).values()
except Exception:
raise
currTime = time()
return (currTime, sum([ int(item) for item in currLinksLoad ]), 0)
def pollLinksOctetsPackets(self):
""" poll the router for the number of bytes and number of packets received on each link
computing the total router state"""
oid = self.snmpiface.oid_ifInOctets
bulksize = 5*self.num_ifs # polling the router for ifInOctets, ifInUcastPackets, ifInNUcastPackets, ifInDiscards, ifInErrors in a single query using getbulk
try:
currLinksLoad=self.snmpiface.getBulk(oid,bulksize,dontmatch=1) # dontmatch=1 because they are not in the same subtree
except Exception:
raise
octets, packets = (0,0)
for key in currLinksLoad:
if key[:len(oid)]==oid:
octets+=int(currLinksLoad[key]) # calculate the total number of bytes received
elif key[:len(oid)] in [oid[:len(oid)-1]+s for s in ('1','2','3','4')]:
packets+=int(currLinksLoad[key]) # calculate the total number of packets received
currTime = time()
return (currTime, octets, packets)