ifupdown2/addons/dhcp.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014-2017 Cumulus Networks, Inc. All rights reserved.
   4 # Author: Roopa Prabhu, roopa@cumulusnetworks.com
   5 #
   6
   7 import re
   8 import time
   9
  10 try:
  11     import ifupdown2.ifupdown.policymanager as policymanager
  12     import ifupdown2.ifupdown.ifupdownflags as ifupdownflags
  13
  14     from ifupdown2.ifupdown.iface import *
  15     from ifupdown2.ifupdown.utils import utils
  16
  17     from ifupdown2.ifupdownaddons.dhclient import dhclient
  18     from ifupdown2.ifupdownaddons.LinkUtils import LinkUtils
  19     from ifupdown2.ifupdownaddons.modulebase import moduleBase
  20 except ImportError:
  21     import ifupdown.policymanager as policymanager
  22     import ifupdown.ifupdownflags as ifupdownflags
  23
  24     from ifupdown.iface import *
  25     from ifupdown.utils import utils
  26
  27     from ifupdownaddons.dhclient import dhclient
  28     from ifupdownaddons.LinkUtils import LinkUtils
  29     from ifupdownaddons.modulebase import moduleBase
  30
  31
  32 class dhcp(moduleBase):
  33     """ ifupdown2 addon module to configure dhcp on interface """
  34
  35     def __init__(self, *args, **kargs):
  36         moduleBase.__init__(self, *args, **kargs)
  37         self.dhclientcmd = dhclient(**kargs)
  38         self.ipcmd = None
  39
  40     def syntax_check(self, ifaceobj, ifaceobj_getfunc):
  41         return self.is_dhcp_allowed_on(ifaceobj, syntax_check=True)
  42
  43     def is_dhcp_allowed_on(self, ifaceobj, syntax_check):
  44         if ifaceobj.addr_method and 'dhcp' in ifaceobj.addr_method:
  45             return utils.is_addr_ip_allowed_on(ifaceobj, syntax_check=True)
  46         return True
  47
  48     def _up(self, ifaceobj):
  49         # if dhclient is already running do not stop and start it
  50         dhclient4_running = self.dhclientcmd.is_running(ifaceobj.name)
  51         dhclient6_running = self.dhclientcmd.is_running6(ifaceobj.name)
  52
  53         # today if we have an interface with both inet and inet6, if we
  54         # remove the inet or inet6 or both then execute ifreload, we need
  55         # to release/kill the appropriate dhclient(4/6) if they are running
  56         self._down_stale_dhcp_config(ifaceobj, 'inet', dhclient4_running)
  57         self._down_stale_dhcp_config(ifaceobj, 'inet6', dhclient6_running)
  58
  59         try:
  60             dhclient_cmd_prefix = None
  61             dhcp_wait = policymanager.policymanager_api.get_attr_default(
  62                 module_name=self.__class__.__name__, attr='dhcp-wait')
  63             wait = not str(dhcp_wait).lower() == "no"
  64             vrf = ifaceobj.get_attr_value_first('vrf')
  65             if (vrf and self.vrf_exec_cmd_prefix and
  66                 self.ipcmd.link_exists(vrf)):
  67                 dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
  68
  69             if 'inet' in ifaceobj.addr_family:
  70                 if dhclient4_running:
  71                     self.logger.info('dhclient4 already running on %s. '
  72                                      'Not restarting.' % ifaceobj.name)
  73                 else:
  74                     # First release any existing dhclient processes
  75                     try:
  76                         if not ifupdownflags.flags.PERFMODE:
  77                             self.dhclientcmd.stop(ifaceobj.name)
  78                     except:
  79                         pass
  80                     self.dhclientcmd.start(ifaceobj.name, wait=wait,
  81                                            cmd_prefix=dhclient_cmd_prefix)
  82             if 'inet6' in ifaceobj.addr_family:
  83                 if dhclient6_running:
  84                     self.logger.info('dhclient6 already running on %s. '
  85                                      'Not restarting.' % ifaceobj.name)
  86                 else:
  87                     accept_ra = ifaceobj.get_attr_value_first('accept_ra')
  88                     if accept_ra:
  89                         # XXX: Validate value
  90                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  91                                 '.accept_ra', accept_ra)
  92                     autoconf = ifaceobj.get_attr_value_first('autoconf')
  93                     if autoconf:
  94                         # XXX: Validate value
  95                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  96                                 '.autoconf', autoconf)
  97                         try:
  98                             self.dhclientcmd.stop6(ifaceobj.name)
  99                         except:
 100                             pass
 101                     #add delay before starting IPv6 dhclient to
 102                     #make sure the configured interface/link is up.
 103                     time.sleep(2)
 104                     timeout = 10
 105                     while timeout:
 106                         timeout -= 2
 107                         addr_output = utils.exec_command('%s -6 addr show %s'
 108                                                          %(utils.ip_cmd, ifaceobj.name))
 109                         r = re.search('inet6 .* scope link', addr_output)
 110                         if r:
 111                             self.dhclientcmd.start6(ifaceobj.name,
 112                                                     wait=wait,
 113                                                     cmd_prefix=dhclient_cmd_prefix)
 114                             return
 115                         time.sleep(2)
 116
 117         except Exception, e:
 118             self.log_error(str(e), ifaceobj)
 119
 120     def _down_stale_dhcp_config(self, ifaceobj, family, dhclientX_running):
 121         addr_family = ifaceobj.addr_family
 122         try:
 123             if not family in ifaceobj.addr_family and dhclientX_running:
 124                 ifaceobj.addr_family = [family]
 125                 self._dhcp_down(ifaceobj)
 126         except:
 127             pass
 128         finally:
 129             ifaceobj.addr_family = addr_family
 130
 131     def _dhcp_down(self, ifaceobj):
 132         dhclient_cmd_prefix = None
 133         vrf = ifaceobj.get_attr_value_first('vrf')
 134         if (vrf and self.vrf_exec_cmd_prefix and
 135             self.ipcmd.link_exists(vrf)):
 136             dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
 137         if 'inet6' in ifaceobj.addr_family:
 138             self.dhclientcmd.release6(ifaceobj.name, dhclient_cmd_prefix)
 139         if 'inet' in ifaceobj.addr_family:
 140             self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
 141
 142     def _down(self, ifaceobj):
 143         self._dhcp_down(ifaceobj)
 144         self.ipcmd.link_down(ifaceobj.name)
 145
 146     def _query_check(self, ifaceobj, ifaceobjcurr):
 147         status = ifaceStatus.SUCCESS
 148         dhcp_running = False
 149
 150         dhcp_v4 = self.dhclientcmd.is_running(ifaceobjcurr.name)
 151         dhcp_v6 = self.dhclientcmd.is_running6(ifaceobjcurr.name)
 152
 153         if dhcp_v4:
 154             dhcp_running = True
 155             if 'inet' not in ifaceobj.addr_family and not dhcp_v6:
 156                 status = ifaceStatus.ERROR
 157             ifaceobjcurr.addr_method = 'dhcp'
 158         if dhcp_v6:
 159             dhcp_running = True
 160             if 'inet6' not in ifaceobj.addr_family and not dhcp_v4:
 161                 status = ifaceStatus.ERROR
 162             ifaceobjcurr.addr_method = 'dhcp'
 163         ifaceobjcurr.addr_family = ifaceobj.addr_family
 164         if not dhcp_running:
 165             ifaceobjcurr.addr_family = []
 166             status = ifaceStatus.ERROR
 167         ifaceobjcurr.status = status
 168
 169     def _query_running(self, ifaceobjrunning):
 170         if not self.ipcmd.link_exists(ifaceobjrunning.name):
 171             return
 172         if self.dhclientcmd.is_running(ifaceobjrunning.name):
 173             ifaceobjrunning.addr_family.append('inet')
 174             ifaceobjrunning.addr_method = 'dhcp'
 175         if self.dhclientcmd.is_running6(ifaceobjrunning.name):
 176             ifaceobjrunning.addr_family.append('inet6')
 177             ifaceobjrunning.addr_method = 'dhcp6'
 178
 179     _run_ops = {'up' : _up,
 180                'down' : _down,
 181                'pre-down' : _down,
 182                'query-checkcurr' : _query_check,
 183                'query-running' : _query_running }
 184
 185     def get_ops(self):
 186         """ returns list of ops supported by this module """
 187         return self._run_ops.keys()
 188
 189     def _init_command_handlers(self):
 190         if not self.ipcmd:
 191             self.ipcmd = LinkUtils()
 192
 193     def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
 194         """ run dhcp configuration on the interface object passed as argument
 195
 196         Args:
 197             **ifaceobj** (object): iface object
 198
 199             **operation** (str): any of 'up', 'down', 'query-checkcurr',
 200                                  'query-running'
 201
 202         Kwargs:
 203             **query_ifaceobj** (object): query check ifaceobject. This is only
 204                 valid when op is 'query-checkcurr'. It is an object same as
 205                 ifaceobj, but contains running attribute values and its config
 206                 status. The modules can use it to return queried running state
 207                 of interfaces. status is success if the running state is same
 208                 as user required state in ifaceobj. error otherwise.
 209         """
 210         op_handler = self._run_ops.get(operation)
 211         if not op_handler:
 212             return
 213         try:
 214             if (operation != 'query-running' and
 215                    (ifaceobj.addr_method != 'dhcp' and
 216                        ifaceobj.addr_method != 'dhcp6')):
 217                 return
 218         except:
 219             return
 220         if not self.is_dhcp_allowed_on(ifaceobj, syntax_check=False):
 221             return
 222         self._init_command_handlers()
 223         if operation == 'query-checkcurr':
 224             op_handler(self, ifaceobj, query_ifaceobj)
 225         else:
 226             op_handler(self, ifaceobj)