Detecting router IP

netwatch.py

@@ -12,32 +12,33 @@ import curses.wrapper
 from gi.repository import GLib, GObject
 # Pinging
 import subprocess
+import socket, struct
 # Regex
 import re
 # Unicode
 import locale
+
+# Configure Unicode
 locale.setlocale(locale.LC_ALL, '')
 encoding = locale.getpreferredencoding()
 
-# Variables
-internet_host = "8.8.8.8"
-router_host = "192.168.1.1"
-ping_frequency = 5
-
 class Pinger:
   internet_log = []
   router_log = []
 
   def run(self):
-    internet_latency = self.ping(internet_host,self.internet_log)
-    self.draw("Internet:",self.internet_log,internet_latency,0)
+    self.stdscr.clear() # clear window during each run
 
-    router_latency = self.ping(router_host,self.router_log)
-    self.draw("Router:",self.router_log,router_latency,2)
+    internet_latency = self.ping(self.internet_host,self.internet_log)
+    self.draw("Internet:",self.internet_host,self.internet_log,internet_latency,0)
+
+    router_latency = self.ping(self.router_host,self.router_log)
+    self.draw("Router:",self.router_host,self.router_log,router_latency,2)
 
     # Schedule next run
     GObject.timeout_add_seconds(self.timeout, self.run)
 
+    self.stdscr.refresh() # output drawing to screen
 
   def ping(self,host,log):
 
@@ -67,61 +68,90 @@ class Pinger:
 
     return latency
 
-  def draw(self,title,log,latency,line):
+  def draw(self,title,subtitle,log,latency,line):
  
     # Draw internet heading on specified line
-    self.stdscr.addstr(line,0,title, curses.color_pair(3))
+    self.stdscr.addstr(line,0,title, self.COL_DEFAULT)
+    self.stdscr.addstr(line,len(title)+1,subtitle, self.COL_MUTE)
     interpret = self.interpret_ping(latency)
-    self.stdscr.addstr(line,10,interpret['subjective'], interpret['color'])
-    right_align = self.ping_log_max_size-16
-    self.stdscr.addstr(line,right_align,str(round(latency/1000,3))+" second lag", interpret['color'])
+    heading = str(round(latency/1000,3))+" second lag ("+interpret['subjective']+")"
+    right_align = self.ping_log_max_size-len(heading)
+    self.stdscr.addstr(line,right_align,heading, interpret['color'])
 
     # Draw graph on next line
     for idx,entry in enumerate(log):
       self.stdscr.addstr(line+1,idx,entry['graph'].encode(encoding), entry['color'])
-    self.stdscr.refresh()
 
   def interpret_ping(self, ping):
     ping = float(ping)
     if ping == -1:
       graph = "E "#u'\u2847' # Error
-      color = curses.color_pair(1)
+      color = self.COL_BAD
       subjective = "Down"
     elif ping < 30:
       graph = u'\u2840'
-      color = curses.color_pair(2)
+      color = self.COL_GOOD
       subjective = "Great"
     elif ping < 70:
       graph = u'\u2844'
-      color = curses.color_pair(2)
+      color = self.COL_GOOD
       subjective = "Good"
     elif ping < 120:
       graph = u'\u2846'
-      color = curses.color_pair(1)
+      color = self.COL_WARN
       subjective = "Fair"
     else:
       graph = u'\u2847'
-      color = curses.color_pair(1)
+      color = self.COL_BAD
       subjective = "Poor"
     return {'graph': graph, 'color': color, 'subjective': subjective, 'ping': float(ping)}
 
+#  def find_router_ip(self):
+#    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+#    s.connect((self.internet_host,80))
+#    my_ip = s.getsockname()[0]
+#    s.close()
+#    return my_ip
+
+  def get_default_gateway_linux(self):
+    # Read the default gateway directly from /proc.
+    with open("/proc/net/route") as fh:
+      for line in fh:
+        fields = line.strip().split()
+        if fields[1] != '00000000' or not int(fields[3], 16) & 2:
+          continue
+
+        return socket.inet_ntoa(struct.pack("<L", int(fields[2], 16)))
+
   def __init__(self, stdscr):
+    # Parameters
+    self.internet_host = "8.8.8.8"
+    self.router_host = self.get_default_gateway_linux()
+    self.timeout = 5 # Ping frequency
  
-    # Initialize color pairs
+    # Create color constants
     curses.use_default_colors()
+
     curses.init_pair(1, curses.COLOR_RED, -1)
     curses.init_pair(2, curses.COLOR_GREEN, -1)
     curses.init_pair(3, curses.COLOR_WHITE, -1)
+    curses.init_pair(4, curses.COLOR_YELLOW, -1)
+    curses.init_pair(5, curses.COLOR_WHITE, -1)
+
+    self.COL_BAD = curses.color_pair(1)
+    self.COL_GOOD = curses.color_pair(2)
+    self.COL_DEFAULT = curses.color_pair(3)|curses.A_BOLD
+    self.COL_WARN = curses.color_pair(4)
+    self.COL_MUTE = curses.color_pair(5)|curses.A_DIM
+
+    # Initialize screen
+    self.stdscr = stdscr
+    self.window_size = stdscr.getmaxyx() # returns an array [height,width]
+    self.ping_log_max_size = self.window_size[1] # max width
 
     # Hide cursor
     curses.curs_set(0)
 
-    # initialize screen and parameters
-    self.stdscr = stdscr
-    self.window_size = stdscr.getmaxyx() # returns an array [height,width]
-    self.ping_log_max_size = self.window_size[1] # max width
-    self.timeout = ping_frequency
- 
     # start the ping process
     self.run()