ddwrt.py

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#!/usr/bin/env python
#
# Copyright 2017 Fraunhofer Institute for Manufacturing Engineering and Automation (IPA)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import os, sys, string, time, getopt, re
import io

import mechanize
import csv
import gc

import rospy
from std_msgs.msg import Header
from cob_msgs.msg import AccessPoint, Network, SiteSurvey

def breakUpTrash():
    for item in gc.garbage:
        if type(item) == dict:
            for s in item.keys_iter():
                del item[s]
        del gc.garbage[:]

class WifiAP:
  def __init__(self, hostname, username, password):
    self.hostname = hostname
    self.username = username
    self.password = password

  def newBrowser(self):
    # Create new browsers all the time because its data structures grow
    # unboundedly (texas#135)
    br = mechanize.Browser()
    #br.add_password(self.hostname, self.username, self.password)
    #br.set_handle_robots(None)
    return br

  def fetchSiteSurvey(self):
    url = "http://%s/Site_Survey.asp" % self.hostname

    browser = self.newBrowser()
    response = browser.open(url)  # pylint: disable=assignment-from-none

    body = response.read()

    #make sure that we put a stamp on things
    header = Header()
    header.stamp = rospy.Time.now()
    networks = []
    survey = SiteSurvey(header, networks)

    lines = body.split("\n")
    for i in range(len(lines)):
      if lines[i].startswith("var table = "):
        break

    aplines = []
    for j in range(i+1, len(lines)):
      if lines[j].startswith(");"): break
      line = lines[j].strip()
      if not line: continue
      if line[0] == ",": line = line[1:]

      aplines.append(line)

    fp = io.StringIO('\n'.join(aplines))
    reader = csv.reader(fp)
    for row in reader:
      essid = row[0]
      macattr = row[2]
      channel = row[3]
      rssi = row[4]
      noise = row[5]
      beacon = row[6]

      network = Network(macattr, essid, channel, rssi, noise, beacon)
      survey.networks.append(network)
    return survey

  def fetchBandwidthStats(self, interface):
    url = "http://%s/fetchif.cgi?%s" % (self.hostname, interface)

    browser = self.newBrowser()
    response = browser.open(url)  # pylint: disable=assignment-from-none
    body = response.read()

    lines = body.split("\n")

    if len(lines) > 1:
      line = lines[1].strip()
      iparts = line.split(":", 1)
      parts = iparts[1].split()
      print(interface, parts)


  def fetchCurrentAP(self):
    url = "http://%s/Status_Wireless.live.asp" % self.hostname

    browser = self.newBrowser()
    response = browser.open(url)  # pylint: disable=assignment-from-none
    body = response.read()

    line = None
    lines = body.split("\n")

    d = {}
    for line in lines:
      line = line[1:-1]
      line = line.replace(" ", "")
      parts = line.split("::", 1)
      if len(parts) == 2:
        d[parts[0]] = parts[1]

    essid = d.get('wl_ssid', '')
    wl_channel = d.get('wl_channel', '').split()[0]
    channel = int(wl_channel)
    rate = d.get('wl_rate', '')

    signal = None
    noise = None
    snr = None
    quality = None

    tx_power = d.get('wl_xmit', '')

    active_wireless = d.get('active_wireless', None)
    ap = None
    if active_wireless:
      active_wireless = active_wireless.replace("'", "")
      parts = active_wireless.split(",")
      macaddr = parts[0]
      #interface = parts[1]
      if len(parts) == 7:
        signal = int(parts[4])
        noise = int(parts[5])
        snr = int(parts[6])
        quality = signal * 1.24 + 116
      else:
        signal = int(parts[5])
        noise = int(parts[6])
        snr = int(parts[7])
        quality = int(parts[8])/10

      #self.fetchBandwidthStats(interface)

      #make sure that we put a stamp on things
      header = Header()
      header.stamp = rospy.Time.now()

      ap = AccessPoint(header=header,
                       essid=essid,
                       macaddr=macaddr,
                       signal=signal,
                       noise=noise,
                       snr=snr,
                       channel=channel,
                       rate=rate,
                       quality=quality,
                       tx_power=tx_power)

    return ap


def loop():
  rospy.init_node("wifi_ddwrt")

  router_ip = rospy.get_param('~router', 'wifi-router')
  username = rospy.get_param('~username', 'root')
  password = rospy.get_param('~password', '')

  ap = WifiAP(router_ip, username, password)

  pub1 = rospy.Publisher("ddwrt/sitesurvey", SiteSurvey, queue_size=50 )
  pub2 = rospy.Publisher("ddwrt/accesspoint", AccessPoint, queue_size=50 )

  r = rospy.Rate(.5)
  lastTime = 0
  last_ex = ''
  while not rospy.is_shutdown():
    breakUpTrash() # Needed because mechanize leaves data structures that the GC sees as uncollectable (texas#135)
    try:
      if time.time() - lastTime > 60:
        survey = ap.fetchSiteSurvey()
        pub1.publish(survey)
        lastTime = time.time()
      node = ap.fetchCurrentAP()
      if node: pub2.publish(node)
      last_ex = ''
    except Exception as e:
      if e != last_ex:
          rospy.logwarn("Caught exception %s" % e)
      last_ex = e
    r.sleep()

def test():
  router_ip = rospy.get_param('~router_ip', 'wifi-router')
  username = rospy.get_param('~username', 'root')
  password = rospy.get_param('~password', '')

  ap = WifiAP(router_ip, username, password)
  while 1:
    if 0:
      survey = ap.fetchSiteSurvey()
      print(survey)
    if 1:
      node = ap.fetchCurrentAP()
      print(node)

def usage(progname):
  print(__doc__ % vars())

def main(argv, stdout, environ):
  progname = argv[0]
  optlist, _ = getopt.getopt(argv[1:], "", ["help", "test",])

  testflag = 0

  for (field, _) in optlist:
    if field == "--help":
      usage(progname)
      return
    elif field == "--test":
      testflag = 1

  if testflag:
    test()
    return

  loop()

if __name__ == "__main__":
  main(sys.argv, sys.stdout, os.environ)