Added a device tracker for dd-wrt routers

homeassistant/components/device_tracker/ddwrt.py

+""" Supports scanning a DD-WRT router. """
+import logging
+import json
+from datetime import timedelta
+import re
+import threading
+import requests
+
+from homeassistant.const import CONF_HOST, CONF_USERNAME, CONF_PASSWORD
+from homeassistant.helpers import validate_config
+from homeassistant.util import Throttle
+from homeassistant.components.device_tracker import DOMAIN
+
+# Return cached results if last scan was less then this time ago
+MIN_TIME_BETWEEN_SCANS = timedelta(seconds=5)
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def get_scanner(hass, config):
+    """ Validates config and returns a DdWrt scanner. """
+    if not validate_config(config,
+                           {DOMAIN: [CONF_HOST, CONF_USERNAME, CONF_PASSWORD]},
+                           _LOGGER):
+        return None
+
+    scanner = DdWrtDeviceScanner(config[DOMAIN])
+
+    return scanner if scanner.success_init else None
+
+
+# pylint: disable=too-many-instance-attributes
+class DdWrtDeviceScanner(object):
+    """ This class queries a wireless router running DD-WRT firmware
+    for connected devices. Adapted from Tomato scanner.
+    """
+
+    def __init__(self, config):
+        self.host = config[CONF_HOST]
+        self.username = config[CONF_USERNAME]
+        self.password = config[CONF_PASSWORD]        
+
+        self.lock = threading.Lock()
+
+        self.last_results = {}
+
+        self.mac2name = None
+
+        #test the router is accessible
+        url = 'http://{}/Status_Wireless.live.asp'.format(self.host)
+        data = self.get_ddwrt_data(url)
+        self.success_init = data is not None
+
+    def scan_devices(self):
+        """ Scans for new devices and return a
+            list containing found device ids. """
+
+        self._update_info()
+
+        return self.last_results
+
+    def get_device_name(self, device):
+        """ Returns the name of the given device or None if we don't know. """
+
+        with self.lock:
+            # if not initialised and not already scanned and not found
+            if self.mac2name is None or device not in self.mac2name:
+                url = 'http://{}/Status_Lan.live.asp'.format(self.host)
+                data = self.get_ddwrt_data(url)
+
+                if not data:
+                    return
+
+                dhcp_leases = data.get('dhcp_leases', None)
+                if dhcp_leases:
+                    
+                    # remove leading and trailing single quotes
+                    cleaned_str = dhcp_leases.strip().strip('"')
+                    elements = cleaned_str.split('","')                    
+                    num_clients = int(len(elements)/5)  
+                    self.mac2name = {}                  
+                    for x in range(0, num_clients):
+                        # this is stupid but the data is a single array
+                        # every 5 elements represents one hosts, the MAC
+                        # is the third element and the name is the first
+                        mac_index = (x * 5) + 2
+                        if mac_index < len(elements):                           
+                            self.mac2name[elements[mac_index]] = elements[x * 5]
+                                
+            return self.mac2name.get(device, None)
+
+    @Throttle(MIN_TIME_BETWEEN_SCANS)
+    def _update_info(self):
+        """ Ensures the information from the DdWrt router is up to date.
+            Returns boolean if scanning successful. """
+        if not self.success_init:
+            return False
+
+        with self.lock:
+            _LOGGER.info("Checking ARP")
+
+            url = 'http://{}/Status_Wireless.live.asp'.format(self.host)
+            data = self.get_ddwrt_data(url)
+
+            if not data:
+                return False
+
+            if data:
+                self.last_results = []
+                active_clients = data.get('active_wireless', None)
+                if active_clients:
+                    # This is really lame, instead of using JSON the ddwrt UI uses
+                    # it's own data format for some reason and then regex's out
+                    # values so I guess I have to do the same, LAME!!!
+                    
+                    # remove leading and trailing single quotes
+                    clean_str = active_clients.strip().strip("'")
+                    elements = clean_str.split("','")
+                    
+                    num_clients = int(len(elements)/9)                    
+                    for x in range(0, num_clients):
+                        # get every 9th element which is the MAC address
+                        index = x * 9
+                        if index < len(elements):                            
+                            self.last_results.append(elements[index])
+                            
+                    return True
+
+            return False
+
+    def get_ddwrt_data(self, url):
+        """ Retrieve data from DD-WRT and return parsed result  """
+        try:
+            response = requests.get(url, auth=(self.username, 
+                self.password), timeout=4)
+        except requests.exceptions.Timeout:
+            _LOGGER.exception("Connection to the router timed out")
+            return
+        if response.status_code == 200:
+            return _parse_ddwrt_response(response.text)
+        elif res.status_code == 401:
+        # Authentication error
+            _LOGGER.exception(
+                "Failed to authenticate, "
+                "please check your username and password")
+            return
+        else:
+            _LOGGER.error("Invalid response from ddwrt: %s", res)
+
+
+def _parse_ddwrt_response(data_str):
+    """ Parse the awful DD-WRT data format, why didn't they use JSON????. 
+        This code is a python version of how they are parsing in the JS  """
+    data = {}
+    pattern = re.compile(r'\{(\w+)::([^\}]*)\}')
+    for (key, val) in re.findall(pattern, data_str):
+        data[key] = val
+
+    return data
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