iotop/genetlink.py

   1 '''
   2 Netlink message generation/parsing
   3
   4 Copyright 2007          Johannes Berg <johannes@sipsolutions.net>
   5
   6 GPLv2
   7 '''
   8
   9 import struct
  10 from netlink import *
  11
  12 CTRL_CMD_UNSPEC         = 0
  13 CTRL_CMD_NEWFAMILY      = 1
  14 CTRL_CMD_DELFAMILY      = 2
  15 CTRL_CMD_GETFAMILY      = 3
  16 CTRL_CMD_NEWOPS         = 4
  17 CTRL_CMD_DELOPS         = 5
  18 CTRL_CMD_GETOPS         = 6
  19
  20 CTRL_ATTR_UNSPEC        = 0
  21 CTRL_ATTR_FAMILY_ID     = 1
  22 CTRL_ATTR_FAMILY_NAME   = 2
  23 CTRL_ATTR_VERSION       = 3
  24 CTRL_ATTR_HDRSIZE       = 4
  25 CTRL_ATTR_MAXATTR       = 5
  26 CTRL_ATTR_OPS           = 6
  27
  28 class GenlHdr:
  29     def __init__(self, cmd, version = 0):
  30         self.cmd = cmd
  31         self.version = version
  32     def _dump(self):
  33         return struct.pack("BBxx", self.cmd, self.version)
  34
  35 def _genl_hdr_parse(data):
  36     return GenlHdr(*struct.unpack("BBxx", data))
  37
  38 GENL_ID_CTRL            = NLMSG_MIN_TYPE
  39
  40 class GeNlMessage(Message):
  41     def __init__(self, family, cmd, attrs=[], flags=0):
  42         self.cmd = cmd
  43         self.attrs = attrs
  44         self.family = family
  45         Message.__init__(self, family, flags=flags, payload=[GenlHdr(self.cmd)]+attrs)
  46
  47 class Controller:
  48     def __init__(self, conn):
  49         self.conn = conn
  50     def get_family_id(self, family):
  51         a = NulStrAttr(CTRL_ATTR_FAMILY_NAME, family)
  52         m = GeNlMessage(GENL_ID_CTRL, CTRL_CMD_GETFAMILY, flags=NLM_F_REQUEST, attrs=[a])
  53         m.send(self.conn)
  54         m = self.conn.recv()
  55         gh = _genl_hdr_parse(m.payload[:4])
  56         attrs = parse_attributes(m.payload[4:])
  57         return attrs[CTRL_ATTR_FAMILY_ID].u16()
  58
  59 connection = Connection(NETLINK_GENERIC)
  60 controller = Controller(connection)