sioc.py

   1 # $Id$
   2 # vim:set ts=4 sw=4 expandtab:
   3 # (c) Copyright 2008 The Trustees of Princeton University
   4
   5 import os
   6 import socket
   7 import fcntl
   8 import struct
   9 import subprocess
  10
  11 SIOCGIFADDR = 0x8915
  12 SIOCGIFADDR_struct = "16xH2xI8x"
  13 SIOCGIFHWADDR = 0x8927
  14 SIOCGIFHWADDR_struct = "16x2x6B8x"
  15
  16 def _format_ip(nip):
  17     ip = socket.ntohl(nip)
  18     return "%d.%d.%d.%d" % ((ip & 0xff000000) >> 24,
  19                             (ip & 0x00ff0000) >> 16,
  20                             (ip & 0x0000ff00) >> 8,
  21                             (ip & 0x000000ff))
  22
  23 def gifaddr(interface):
  24     s = None
  25     try:
  26         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
  27         ifreq = fcntl.ioctl(s.fileno(), SIOCGIFADDR, struct.pack("16s16x", interface))
  28         (family, ip) = struct.unpack(SIOCGIFADDR_struct, ifreq)
  29         if family == socket.AF_INET:
  30             return _format_ip(ip)
  31     finally:
  32         if s is not None:
  33             s.close()
  34     return None
  35
  36 def gifconf():
  37     ret = {}
  38     ip = subprocess.Popen(["/sbin/ip", "-4", "addr", "ls"],
  39                           stdin=subprocess.PIPE, stdout=subprocess.PIPE,
  40                           stderr=subprocess.PIPE, close_fds=True)
  41     (stdout, stderr) = ip.communicate()
  42     # no wait is needed when using communicate
  43     for line in stdout.split("\n"):
  44         fields = [ field.strip() for field in line.split() ]
  45         if fields and fields[0] == "inet":
  46             # fields[-1] is the last column in fields, which has the interface name
  47             # fields[1] has the IP address / netmask width
  48             ret[fields[-1]] = fields[1].split("/")[0]
  49     return ret
  50
  51 def gifhwaddr(interface):
  52     s = None
  53     try:
  54         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
  55         ifreq = fcntl.ioctl(s.fileno(), SIOCGIFHWADDR, struct.pack("16s16x", interface))
  56         mac = struct.unpack(SIOCGIFHWADDR_struct, ifreq)
  57         return "%02x:%02x:%02x:%02x:%02x:%02x" % mac
  58     finally:
  59         s.close()
  60     return None