sioc.py

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