ifupdown2/addons/loopback.py

   1 #!/usr/bin/python
   2
   3 # This should be pretty simple and might not really even need to exist.
   4 # The key is that we need to call link_create with a type of "dummy"
   5 # since that will translate to 'ip link add loopbackX type dummy'
   6 # The config file should probably just indicate that the type is
   7 # loopback or dummy.
   8
   9 from ifupdown.iface import *
  10 from ifupdownaddons.modulebase import moduleBase
  11 from ifupdownaddons.iproute2 import iproute2
  12 import logging
  13
  14 class loopback(moduleBase):
  15     _modinfo = {'mhelp' : 'configure extra loopback module based on ' +
  16                           'dummy device' }
  17
  18     def __init__(self, *args, **kargs):
  19         moduleBase.__init__(self, *args, **kargs)
  20         self.ipcmd = None
  21
  22     def _is_loopback_by_name(self, ifacename):
  23         return 'loop' in ifacename
  24
  25     def _up(self, ifaceobj):
  26         if self._is_loopback_by_name(ifaceobj.name):
  27            self.ipcmd.link_create(ifaceobj.name, 'dummy')
  28
  29     def _down(self, ifaceobj):
  30         if not self.PERFMODE and not self.ipcmd.link_exists(ifaceobj.name):
  31            return
  32         try:
  33             self.ipcmd.link_delete(ifaceobj.name)
  34         except Exception, e:
  35             self.log_warn(str(e))
  36
  37     def _query_check(self, ifaceobj, ifaceobjcurr):
  38         if not self.ipcmd.link_exists(ifaceobj.name):
  39            return
  40
  41     _run_ops = {'pre-up' : _up,
  42                'post-down' : _down,
  43                'query-checkcurr' : _query_check}
  44
  45     def get_ops(self):
  46         return self._run_ops.keys()
  47
  48     def _init_command_handlers(self):
  49         if not self.ipcmd:
  50             self.ipcmd = iproute2(**self.get_flags())
  51
  52     def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
  53         op_handler = self._run_ops.get(operation)
  54         if not op_handler:
  55             return
  56         if (operation != 'query-running' and
  57                 not self._is_loopback_by_name(ifaceobj.name)):
  58             return
  59         self._init_command_handlers()
  60         if operation == 'query-checkcurr':
  61             op_handler(self, ifaceobj, query_ifaceobj)
  62         else:
  63             op_handler(self, ifaceobj)