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             inet6_ll_wait = policymanager.policymanager_api.get_iface_default(module_name=self.__class__.__name__, \
  65                 ifname=ifaceobj.name, attr='inet6-ll-wait')
  66             try:
  67                 ll_wait_time = int(inet6_ll_wait)
  68             except:
  69                 ll_wait_time = 10
  70                 pass
  71
  72             vrf = ifaceobj.get_attr_value_first('vrf')
  73             if (vrf and self.vrf_exec_cmd_prefix and
  74                 self.ipcmd.link_exists(vrf)):
  75                 dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
  76
  77             if 'inet' in ifaceobj.addr_family:
  78                 if dhclient4_running:
  79                     self.logger.info('dhclient4 already running on %s. '
  80                                      'Not restarting.' % ifaceobj.name)
  81                 else:
  82                     # First release any existing dhclient processes
  83                     try:
  84                         if not ifupdownflags.flags.PERFMODE:
  85                             self.dhclientcmd.stop(ifaceobj.name)
  86                     except:
  87                         pass
  88                     self.dhclientcmd.start(ifaceobj.name, wait=wait,
  89                                            cmd_prefix=dhclient_cmd_prefix)
  90             if 'inet6' in ifaceobj.addr_family:
  91                 if dhclient6_running:
  92                     self.logger.info('dhclient6 already running on %s. '
  93                                      'Not restarting.' % ifaceobj.name)
  94                 else:
  95                     accept_ra = ifaceobj.get_attr_value_first('accept_ra')
  96                     if accept_ra:
  97                         # XXX: Validate value
  98                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  99                                 '.accept_ra', accept_ra)
 100                     autoconf = ifaceobj.get_attr_value_first('autoconf')
 101                     if autoconf:
 102                         # XXX: Validate value
 103                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
 104                                 '.autoconf', autoconf)
 105                         try:
 106                             self.dhclientcmd.stop6(ifaceobj.name)
 107                         except:
 108                             pass
 109                     #add delay before starting IPv6 dhclient to
 110                     #make sure the configured interface/link is up.
 111                     if ll_wait_time:
 112                        timeout = ll_wait_time
 113                        time.sleep(1)
 114                     else:
 115                        timeout = ll_wait_time+1
 116
 117                     while timeout:
 118                         addr_output = utils.exec_command('%s -6 addr show %s'
 119                                                          %(utils.ip_cmd, ifaceobj.name))
 120                         r = re.search('inet6 .* scope link', addr_output)
 121                         if r:
 122                             self.dhclientcmd.start6(ifaceobj.name,
 123                                                     wait=wait,
 124                                                     cmd_prefix=dhclient_cmd_prefix)
 125                             return
 126                         timeout -= 1
 127                         if timeout:
 128                             time.sleep(1)
 129
 130         except Exception, e:
 131             self.log_error(str(e), ifaceobj)
 132
 133     def _down_stale_dhcp_config(self, ifaceobj, family, dhclientX_running):
 134         addr_family = ifaceobj.addr_family
 135         try:
 136             if not family in ifaceobj.addr_family and dhclientX_running:
 137                 ifaceobj.addr_family = [family]
 138                 self._dhcp_down(ifaceobj)
 139         except:
 140             pass
 141         finally:
 142             ifaceobj.addr_family = addr_family
 143
 144     def _dhcp_down(self, ifaceobj):
 145         dhclient_cmd_prefix = None
 146         vrf = ifaceobj.get_attr_value_first('vrf')
 147         if (vrf and self.vrf_exec_cmd_prefix and
 148             self.ipcmd.link_exists(vrf)):
 149             dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
 150         if 'inet6' in ifaceobj.addr_family:
 151             self.dhclientcmd.release6(ifaceobj.name, dhclient_cmd_prefix)
 152         if 'inet' in ifaceobj.addr_family:
 153             self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
 154
 155     def _down(self, ifaceobj):
 156         self._dhcp_down(ifaceobj)
 157         self.ipcmd.link_down(ifaceobj.name)
 158
 159     def _query_check(self, ifaceobj, ifaceobjcurr):
 160         status = ifaceStatus.SUCCESS
 161         dhcp_running = False
 162
 163         dhcp_v4 = self.dhclientcmd.is_running(ifaceobjcurr.name)
 164         dhcp_v6 = self.dhclientcmd.is_running6(ifaceobjcurr.name)
 165
 166         if dhcp_v4:
 167             dhcp_running = True
 168             if 'inet' not in ifaceobj.addr_family and not dhcp_v6:
 169                 status = ifaceStatus.ERROR
 170             ifaceobjcurr.addr_method = 'dhcp'
 171         if dhcp_v6:
 172             dhcp_running = True
 173             if 'inet6' not in ifaceobj.addr_family and not dhcp_v4:
 174                 status = ifaceStatus.ERROR
 175             ifaceobjcurr.addr_method = 'dhcp'
 176         ifaceobjcurr.addr_family = ifaceobj.addr_family
 177         if not dhcp_running:
 178             ifaceobjcurr.addr_family = []
 179             status = ifaceStatus.ERROR
 180         ifaceobjcurr.status = status
 181
 182     def _query_running(self, ifaceobjrunning):
 183         if not self.ipcmd.link_exists(ifaceobjrunning.name):
 184             return
 185         if self.dhclientcmd.is_running(ifaceobjrunning.name):
 186             ifaceobjrunning.addr_family.append('inet')
 187             ifaceobjrunning.addr_method = 'dhcp'
 188         if self.dhclientcmd.is_running6(ifaceobjrunning.name):
 189             ifaceobjrunning.addr_family.append('inet6')
 190             ifaceobjrunning.addr_method = 'dhcp6'
 191
 192     _run_ops = {'up' : _up,
 193                'down' : _down,
 194                'pre-down' : _down,
 195                'query-checkcurr' : _query_check,
 196                'query-running' : _query_running }
 197
 198     def get_ops(self):
 199         """ returns list of ops supported by this module """
 200         return self._run_ops.keys()
 201
 202     def _init_command_handlers(self):
 203         if not self.ipcmd:
 204             self.ipcmd = LinkUtils()
 205
 206     def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
 207         """ run dhcp configuration on the interface object passed as argument
 208
 209         Args:
 210             **ifaceobj** (object): iface object
 211
 212             **operation** (str): any of 'up', 'down', 'query-checkcurr',
 213                                  'query-running'
 214
 215         Kwargs:
 216             **query_ifaceobj** (object): query check ifaceobject. This is only
 217                 valid when op is 'query-checkcurr'. It is an object same as
 218                 ifaceobj, but contains running attribute values and its config
 219                 status. The modules can use it to return queried running state
 220                 of interfaces. status is success if the running state is same
 221                 as user required state in ifaceobj. error otherwise.
 222         """
 223         op_handler = self._run_ops.get(operation)
 224         if not op_handler:
 225             return
 226         try:
 227             if (operation != 'query-running' and
 228                    (ifaceobj.addr_method != 'dhcp' and
 229                        ifaceobj.addr_method != 'dhcp6')):
 230                 return
 231         except:
 232             return
 233         if not self.is_dhcp_allowed_on(ifaceobj, syntax_check=False):
 234             return
 235         self._init_command_handlers()
 236         if operation == 'query-checkcurr':
 237             op_handler(self, ifaceobj, query_ifaceobj)
 238         else:
 239             op_handler(self, ifaceobj)