Source Code for Module commons.networking

 1  # -*- mode: python; tab-width: 4; indent-tabs-mode: nil; py-indent-offset: 4; -*- 
 2  # vim:ft=python:et:sw=4:ts=4 
 3   
 4  """ 
 5  Networking tools. 
 6  """ 
 7   
 8  import os, socket, struct, sys 
 9  from time import * 
10  from contextlib import contextmanager 
11   
12 -class no_mac_addr_exception( Exception ): pass 
13   
14 -def get_mac_addr(): 
15      """ 
16      Simply parses the output of C{ifconfig} or C{ipconfig} to estimate 
17      this machine's IP address. This is not at all reliable, but tends 
18      to work "well enough" for my own purposes. 
19   
20      From U{http://mail.python.org/pipermail/python-list/2005-December/357300.html}. 
21   
22      @copyright: Frank Millman 
23   
24      Note that U{http://libdnet.sf.net/} provides this functionality and much 
25      more. 
26      """ 
27      mac = None 
28      if sys.platform == 'win32': 
29          for line in os.popen("ipconfig /all"): 
30              if line.lstrip().startswith('Physical Address'): 
31                  mac = line.split(':')[1].strip().replace('-',':') 
32                  break 
33      else: 
34          for line in os.popen("/sbin/ifconfig"): 
35              if line.find('Ether') > -1: 
36                  mac = line.split()[4] 
37                  break 
38      if mac is None: 
39          raise no_mac_addr_exception 
40      return mac 
41   
42 -def retry_exp_backoff(initial_backoff, multiplier, func): 
43      """ 
44      Repeatedly invoke L{func} until it succeeds (returns non-None), with 
45      exponentially growing backoff delay between each try. 
46   
47      @param initial_backoff: The initial backoff. 
48      @type initial_backoff: float 
49   
50      @param multiplier: The amount by which the backoff is multiplied on each 
51      failure. 
52      @type multiplier: float 
53   
54      @param func: The zero-argument function to be invoked that returns True on 
55      success and False on failure. 
56      @type func: function 
57   
58      @return: The result of the function 
59      """ 
60      backoff = initial_backoff 
61      while True: 
62          res = func() 
63          if res is not None: return res 
64          print 'backing off for', backoff 
65          sleep(backoff) 
66          backoff = multiplier * backoff 
67   
68  @contextmanager 
69 -def logout(x): 
70      "A context manager for calling the C{logout()} method of an object." 
71      try: yield x 
72      finally: x.logout() 
73   
74 -def inet_nltoa(x): 
75      "Convert an IPv4 address from an int in network byte order to a string." 
76      return socket.inet_ntoa(struct.pack('>L', x)) 
77   
78 -def inet_hltoa(x): 
79      "Convert an IPv4 address from an int in host byte order to a string." 
80      return socket.inet_ntoa(struct.pack('L', x)) 
81