meshenger/main.py

#!/usr/bin/python

import socket, os, time, select, urllib, sys, threading, subprocess

class Meshenger:
  devices = {} #the dictionary of all the nodes this this node has seen
  serve_port = "13338"
  announce_port = 13337
  #own_ip = "0.0.0.0"
  msg_dir = os.path.relpath('msg/')
  exitapp = False #to kill all threads on
  index_last_update = "0" #str(int(time.time()))

  def __init__(self):

    os.system("echo 1 >> /proc/sys/net/ipv6/conf/br-lan/disable_ipv6")
    os.system("echo 1 >> /proc/sys/net/ipv6/conf/br-hotspot/disable_ipv6")
    self.own_ip = self.get_ip_adress()

    if not os.path.exists(self.msg_dir):
      os.mkdir(self.msg_dir)
      print 'Making message directory'

    try:
      d = threading.Thread(target=self.discover)
      d.daemon = True
      d.start()

      a = threading.Thread(target=self.announce)
      a.daemon = True
      a.start()

      n = threading.Thread(target=self.nodeserve)
      n.daemon = True
      n.start()

      c = threading.Thread(target=self.clientserve)
      c.daemon = True
      c.start()

      b = threading.Thread(target=self.build_index)
      b.daemon = True
      b.start()

      #os.system("python meshenger_clientserve.py")

    except (KeyboardInterrupt, SystemExit):
      print 'exiting discovery thread'
      d.join()
      a.join()
      b.join()
      n.join()
      c.join()
      sys.exit()

    while True:
      print 'Entering main loop'
      #
      if len(self.devices) > 0:
        print 'found', len(self.devices),'device(s)'

        for device in self.devices.keys():
          nodepath = self.ip_to_hash_path(device) #make a folder for the node (nodes/'hash'/)
          nodeupdatepath = os.path.join(self.ip_to_hash_path(device), 'lastupdate')


          print 'Checking age of foreign node index'
          print self.devices[device], 'Foreign announce timestamp'
          try:
            foreign_node_update = open(nodeupdatepath).read()
          except:
            foreign_node_update = 0 #means it was never seen before

          print foreign_node_update, 'Locally stored timestamp for device'


          if self.devices[device] > foreign_node_update:
            print 'Foreign node"s index is newer, proceed to download index'
            if not self.get_index(device, nodepath):
              print 'index wget failed'
              continue

            print 'downloading messages'
            if not self.get_messages(device, nodepath):
              print 'getting messages failed'
              continue

            print 'updating node timestamp'
            self.node_timestamp(device)

      time.sleep(5) #free process or ctrl+c

  def node_timestamp(self, ip):
      nodepath = os.path.abspath(os.path.join('nodes', self.hasj(ip)))
      updatepath = os.path.join(nodepath, 'lastupdate')
      with open(updatepath, 'wb') as lastupdate:
        lastupdate.write(self.devices[ip])
      #return updatepath



  def announce(self):
    """
Announce the node's existance to other nodes
"""
    print 'Announcing'
    while not self.exitapp:
      sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
      sock.sendto(self.index_last_update, ("ff02::1", self.announce_port))
      sock.close()
      time.sleep(5)

  def discover(self):
    """
Discover other devices by listening to the Meshenger announce port
"""

    print 'Discovering'
    bufferSize = 1024 # whatever you need?

    s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    s.bind(('::', self.announce_port))
    s.setblocking(0)
    while not self.exitapp:
      result = select.select([s],[],[])[0][0].recvfrom(bufferSize)
      ip = result[1][0]
      print ip, "*"*45
      node_path = os.path.join(os.path.abspath('nodes'), self.hasj(ip))

      if not os.path.exists(node_path) and ip != self.own_ip: 
        #loop for first timef
        self.ip_to_hash_path(ip) #make a folder /nodes/hash
        self.devices[ip] = result[0]
        #self.node_timestamp(ip) #make a local copy of the timestamp in /nodes/hash/updatetimestamp
        print 'New node', ip

      elif os.path.exists(node_path) and ip != self.own_ip:
        print 'Known node', ip
        self.devices[ip] = result[0]


      time.sleep(1)

  def nodeserve(self):
    """
Initialize the nodeserver
"""
    print 'Serving to nodes'
    import meshenger_nodeserve
    meshenger_nodeserve.main()

  def clientserve(self):
    """
Initialize the clientserver
"""
    print 'Serving to client'
    import meshenger_clientserve
    meshenger_clientserve.main()


  def build_index(self):
    """
Make an index file of all the messages present on the node.
Save the time of the last update.
"""


    index_file = os.path.relpath( 'index' )
    previous_index = []
    if not os.path.exists( index_file ):
      with open('index','wb') as index:
        index.write('')
    else:
      previous_index = open( index_file ).read().split()

    index_last_update_file = os.path.relpath( 'index_last_update' )
    if os.path.exists( index_last_update_file ):
      self.index_last_update = open( index_last_update_file ).read()

    while not self.exitapp:

      current_index = []
      for root, folders, files in os.walk( self.msg_dir ):
        if root == 'msg':
          folders.sort()
        else:
          files.sort()
          current_index += [root + '/' + f for f in files]

      if current_index != previous_index:
        with open( index_file, 'w' ) as f:
          f.write( '\n'.join( current_index ))

        self.index_last_update = str( int( time.time()))
        print 'Index updated:', current_index

        with open( os.path.relpath('index_last_update'), 'w') as f:
          f.write( self.index_last_update )

        previous_index = current_index

      time.sleep( 5 )

    """
    print 'Building own index for the first time\n'

    if not os.path.exists('index'):
      with open('index','wb') as index:
        index.write('')
      previous_index = []
    else:
      previous_index = open('index').readlines()

    while not self.exitapp:
      current_index = os.listdir(self.msg_dir)
      if current_index != previous_index:
        with open('index', 'wb') as index:
          for message in os.listdir(self.msg_dir):
            index.write(message)
            index.write('\n')
        self.index_last_update = str(int(time.time()))

        print 'Index updated:', current_index
        with open('index_last_update', 'wb') as indexupdate: 
          indexupdate.write(self.index_last_update) ### misschien moet dit index_last_update zijn

      previous_index = current_index
      time.sleep(5)
      """

  def get_index(self,ip, path):
    """
Download the indices from other nodes.
"""
    # time.sleep(0) # hack to prevent wget bug
    # os.system('wget http://['+ip+'%adhoc0]:'+self.serve_port+'/index -O '+os.path.join(path,'index'))
    command = 'wget http://['+ip+'%adhoc0]:'+self.serve_port+'/index -O '+os.path.join(path,'index')
    print 'get_index: ', command
    status = subprocess.call( command, shell=True )
    return status == 0

  def get_messages(self, ip, path ):
    """
Get new messages from other node based on it's index file
"""


    try:
      with open(os.path.join(path,'index')) as index:
        index = index.read().split('\n')
        for message in index:
          parts = message.split('/')
          dirpath = os.path.join( parts[0], parts[1])
          if not os.path.isdir( dirpath ):
            os.mkdir( dirpath )

          messagepath = os.path.relpath( message )
          if not os.path.exists(messagepath):
            print 'downloading', message, 'to', messagepath
            command = 'wget http://['+ip+'%adhoc0]:' + self.serve_port + '/' + message+' -O ' + messagepath
            status = subprocess.call( command, shell=True)
            if status != 0:
              return False
        # succesfuly downloaded all messages, return true
        return True
    except:
      print 'Failed to download messages'
      return False

  def ip_to_hash_path(self, ip):
    """
Convert a node's ip into a hash and make a directory to store it's files
"""
    if not os.path.exists('nodes'):
      os.mkdir('nodes')

    nodepath = os.path.join(os.path.abspath('nodes'), self.hasj(ip))
    if not os.path.exists(nodepath):
      os.mkdir(nodepath)

    return nodepath

  def hasj(self, ip):
        """
        Convert a node's ip into a hash
        """
        import hashlib
        hasj = hashlib.md5(ip).hexdigest()
        return hasj

  def get_ip_adress(self):
    """
Hack to adhoc0's inet6 adress
"""
    if not os.path.isfile('interfaceip6adress'):
      os.system('ifconfig -a adhoc0 | grep inet6 > /root/meshenger/interfaceip6adress')
    with open('interfaceip6adress', 'r') as a:
      return a.read().split()[2].split('/')[0]



if __name__ == "__main__":
  print "test"
  try:
    meshenger = Meshenger()
  except (KeyboardInterrupt, SystemExit):
    exitapp = True
    raise