megaping.py

Network Administration Visualized 网络管理可视化源码

# -*- coding: ISO8859-1 -*-
#
# Copyright 2002-2004 Norwegian University of Science and Technology
#
# This file is part of Network Administration Visualized (NAV)
#
# NAV is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# NAV is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with NAV; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#
# Authors: Magnus Nordseth <[e-mail]>
#          Stian Soiland   <[e-mail]>

"""Ping multiple hosts at once."""

import threading
import sys
import time
import socket
import select
import os
import random
import struct
import circbuf
import config
from debug import debug

# Do we really need this?
# from netbox import Netbox

# From our friend:
import ip
import icmp

# updating rrd should be moved out
# import rrd

PINGSTRING="Stian og Magnus ruler verden"

def makeSocket():
  sock = socket.socket(socket.AF_INET,
                       socket.SOCK_RAW,
                       socket.IPPROTO_ICMP)
  sock.setblocking(1)
  return sock

class Host:
  def __init__(self, ip):
    self.rnd = random.randint(0,2**16-1)
    self.certain = 0
    self.ip = ip
    self.pkt = icmp.Packet()
    self.pkt.type = icmp.ICMP_ECHO
    self.pkt.id = os.getpid() % 65536
    self.pkt.seq = 0
    self.replies = circbuf.CircBuf()

  def makePacket(self, pingstring=PINGSTRING):
    self.pkt.data = pingstring
    return self.pkt.assemble()

  def getseq(self):
    return self.pkt.seq
  
  def nextseq(self):
    self.pkt.seq = (self.pkt.seq + 1) % 2**16
    if not self.certain and self.pkt.seq > 2:
      self.certain = 1

  def __hash__(self):
    return self.ip.__hash__()

  def __eq__(self, obj):
    if type(obj) == type(''):
      return self.ip == obj
    else:
      return self.ip == obj.ip
  def __repr__(self):
    return "megaping.Host instance for ip %s " % self.ip

  def getState(self, nrping=3):
    # This is the reoundtrip time. Not sure if we need
    # status bit as well...
    return self.replies[0]

class MegaPing:
  """
  Sends icmp echo to multiple hosts in parallell.
  Typical use:
  pinger = megaping.MegaPing()
  pinger.setHosts(['127.0.0.1','10.0.0.1'])
  timeUsed = pinger.ping()
  hostsUp = pinger.answers()
  hostsDown = pinger.noAnswers()
  """
  def __init__(self, socket=None, conf=None):
    if conf is None:
      try:
        self._conf=config.pingconf()
      except:
        debug("Failed to open config file. Using default values.", 2)
        self._conf={}
    else:
      self._conf=conf
    # delay between each packet is transmitted
    self._delay=float(self._conf.get('delay',2))/1000   # convert from ms
    # Timeout before considering hosts as down
    self._timeout = int(self._conf.get('timeout', 5))
    self._hosts = {}
    packetsize = int(self._conf.get('packetsize', 64))
    if packetsize < 44:
      raise """Packetsize (%s) too small to create a proper cookie.
               Must be at least 44."""%packetsize
    self._packetsize=packetsize
    self._pid = os.getpid() % 65536
    self._elapsedtime=0
    
    # Create our common socket
    if socket is None:
      self._sock = makeSocket()
    else:
      self._sock = socket

  def setHosts(self,ips):
    """
    Specify a list of ip addresses to ping. If we alredy have the host
    in our list, we reuse that host object to ensure proper sequence
    increment
    """
    # add new hosts
    currenthosts = {}
    for ip in ips:
      if not self._hosts.has_key(ip):
        currenthosts[ip] = Host(ip)
      else:
        currenthosts[ip] = self._hosts[ip]
    self._hosts = currenthosts
    
  def reset(self):
    self._requests = {}
    self.responses = {}
    self._senderFinished = 0

  def ping(self):
    """
    Send icmp echo to all configured hosts. Returns the
    time used.
    """
    # Start working
    self.reset()
    #kwargs = {'mySocket': makeSocket()}
    self._sender = threading.Thread(target=self._sendRequests, name="sender")
    self._getter = threading.Thread(target=self._getResponses, name="getter")
    self._sender.setDaemon(1)
    self._getter.setDaemon(1)
    self._sender.start()
    self._getter.start()
    self._getter.join()
    return self._elapsedtime
  

  def _getResponses(self):
    start = time.time()
    timeout=self._timeout

    while not self._senderFinished or self._requests:      
      if self._senderFinished:
        runtime=time.time()-self._senderFinished
        if runtime > self._timeout:
          break
        else:
          timeout=self._timeout-runtime
          
      startwait = time.time()
      rd, wt, er = select.select([self._sock], [], [], timeout)
      if rd:
        # okay to use time here, because select has told us
        # there is data and we don't care to measure the time
        # it takes the system to give us the packet.
        arrival = time.time()
        try:
          (pkt, (sender, blapp)) = self._sock.recvfrom(4096)
        except socket.error:
          debug("RealityError -2", 1)
          continue
        # could also use the ip module to get the payload

        repip = ip.Packet(pkt)
        try:
          reply = icmp.Packet(repip.data)
        except ValueError:
          debug("Recived illegeal packet from %s: %s" % (sender,
                                                         repr(repip.data)), 7)
          continue
        if reply.id <> self._pid:
          debug("The id field of the packet does not match for %s"% sender,7)
          continue

        cookie = reply.data[0:14]
        try:
          host = self._requests[cookie]
        except KeyError:
          debug("The packet recieved from %s does not match any of the packets we sent." % repr(sender),7)
          debug("Length of recieved packet: %i Cookie: [%s]" % (len(reply.data), cookie),7)
          continue

        # Puuh.. OK, it IS our package <--- Stain, you're a moron
        pingtime = arrival - host.time
        ### Insert answer to circbuf
        host.replies.push(pingtime)

        #host.logPingTime(pingtime)
        
        debug("Response from %-16s in %03.3f ms" % (sender, pingtime*1000),7)
        del self._requests[cookie]  
      elif self._senderFinished:
          break

    # Everything else timed out
    for host in self._requests.values():
      host.replies.push(None)
      #host.logPingTime(None)
    end = time.time()
    self._elapsedtime=end-start


  def _sendRequests(self, mySocket=None, hosts=None):
    if mySocket is None:
      mySocket = self._sock
    if hosts is None:
      hosts = self._hosts.values()
    for host in hosts:
      if self._requests.has_key(host):
        debug("Duplicate host %s ignored" % host,6)
        continue

      now = time.time()
      host.time = now
      #convert ip to chr (hex notation)
      chrip = "".join(map(lambda x:chr(int(x)), host.ip.split('.')))
      packedtime = struct.pack('d', now)
      packedrnd = struct.pack('H', host.rnd)
      identifier = ''.join([chrip, packedtime, packedrnd])
      cookie = identifier.ljust(self._packetsize-icmp.ICMP_MINLEN)
      # typical cookie: "\x81\xf18F\x06\xf13\xc9\x87\xa8\xceA\xe5m"
      # the cookie is 14 bytes long
      self._requests[identifier] = host
      packet = host.makePacket(cookie)
      host.nextseq()
      try:
        mySocket.sendto(packet, (host.ip, 0))
      except Exception, e:
        debug("Failed to ping %s [%s]" % (host.ip, str(e)), 5)
      time.sleep(self._delay)
    self._senderFinished = time.time()

  def results(self):
    """
    Returns a tuple of
    (ip, roundtriptime) for all hosts.
    Unreachable hosts will have roundtriptime = -1
    """
    reply=[]
    for host in self._hosts.values():
      if host.getState():
        reply.append((host.ip, host.replies[0]))
      else:
        reply.append((host.ip, -1))
    return reply
  
  def noAnswers(self):
    """
    Returns a tuple of
    (ip, timeout) for the unreachable hosts.
    """
    reply=[]
    for host in self._hosts.values():
      if not host.getState():
        reply.append((host.ip, self._timeout))
    return reply

  def answers(self):
    """
    Returns a tuple of
    (ip, roundtriptime) for reachable hosts.
    """
    reply=[]
    for host in self._hosts.values():
      if host.getState():
        reply.append((host.ip, host.replies[0]))
    return reply