addons/dhcp.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014 Cumulus Networks, Inc. All rights reserved.
   4 # Author: Roopa Prabhu, roopa@cumulusnetworks.com
   5 #
   6
   7 try:
   8     import re
   9     from ipaddr import IPNetwork
  10     from sets import Set
  11     from ifupdown.iface import *
  12     import ifupdown.policymanager as policymanager
  13     from ifupdownaddons.modulebase import moduleBase
  14     from ifupdownaddons.dhclient import dhclient
  15     from ifupdownaddons.iproute2 import iproute2
  16     import ifupdown.ifupdownflags as ifupdownflags
  17     from ifupdown.utils import utils
  18     import time
  19     from ifupdown.netlink import netlink
  20 except ImportError, e:
  21     raise ImportError (str(e) + "- required module not found")
  22
  23 class dhcp(moduleBase):
  24     """ ifupdown2 addon module to configure dhcp on interface """
  25
  26     def __init__(self, *args, **kargs):
  27         moduleBase.__init__(self, *args, **kargs)
  28         self.dhclientcmd = dhclient(**kargs)
  29         self.ipcmd = None
  30
  31     def syntax_check(self, ifaceobj, ifaceobj_getfunc):
  32         return self.is_dhcp_allowed_on(ifaceobj, syntax_check=True)
  33
  34     def is_dhcp_allowed_on(self, ifaceobj, syntax_check):
  35         if ifaceobj.addr_method and 'dhcp' in ifaceobj.addr_method:
  36             return utils.is_addr_ip_allowed_on(ifaceobj, syntax_check=True)
  37         return True
  38
  39     def _up(self, ifaceobj):
  40         # if dhclient is already running do not stop and start it
  41         dhclient4_running = self.dhclientcmd.is_running(ifaceobj.name)
  42         dhclient6_running = self.dhclientcmd.is_running6(ifaceobj.name)
  43
  44         # today if we have an interface with both inet and inet6, if we
  45         # remove the inet or inet6 or both then execute ifreload, we need
  46         # to release/kill the appropriate dhclient(4/6) if they are running
  47         self._down_stale_dhcp_config(ifaceobj, 'inet', dhclient4_running)
  48         self._down_stale_dhcp_config(ifaceobj, 'inet6', dhclient6_running)
  49
  50         try:
  51             dhclient_cmd_prefix = None
  52             dhcp_wait = policymanager.policymanager_api.get_attr_default(
  53                 module_name=self.__class__.__name__, attr='dhcp-wait')
  54             wait = not str(dhcp_wait).lower() == "no"
  55             vrf = ifaceobj.get_attr_value_first('vrf')
  56             if (vrf and self.vrf_exec_cmd_prefix and
  57                 self.ipcmd.link_exists(vrf)):
  58                 dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
  59
  60             if 'inet' in ifaceobj.addr_family:
  61                 if dhclient4_running:
  62                     self.logger.info('dhclient4 already running on %s. '
  63                                      'Not restarting.' % ifaceobj.name)
  64                 else:
  65                     # First release any existing dhclient processes
  66                     try:
  67                         if not ifupdownflags.flags.PERFMODE:
  68                             self.dhclientcmd.stop(ifaceobj.name)
  69                     except:
  70                         pass
  71                     self.dhclientcmd.start(ifaceobj.name, wait=wait,
  72                                            cmd_prefix=dhclient_cmd_prefix)
  73             if 'inet6' in ifaceobj.addr_family:
  74                 if dhclient6_running:
  75                     self.logger.info('dhclient6 already running on %s. '
  76                                      'Not restarting.' % ifaceobj.name)
  77                 else:
  78                     accept_ra = ifaceobj.get_attr_value_first('accept_ra')
  79                     if accept_ra:
  80                         # XXX: Validate value
  81                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  82                                 '.accept_ra', accept_ra)
  83                     autoconf = ifaceobj.get_attr_value_first('autoconf')
  84                     if autoconf:
  85                         # XXX: Validate value
  86                         self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  87                                 '.autoconf', autoconf)
  88                         try:
  89                             self.dhclientcmd.stop6(ifaceobj.name)
  90                         except:
  91                             pass
  92                     #add delay before starting IPv6 dhclient to
  93                     #make sure the configured interface/link is up.
  94                     time.sleep(2)
  95                     timeout = 10
  96                     while timeout:
  97                         timeout -= 2
  98                         addr_output = utils.exec_command('ip -6 addr show %s'
  99                                                          % ifaceobj.name)
 100                         r = re.search('inet6 .* scope link', addr_output)
 101                         if r:
 102                             self.dhclientcmd.start6(ifaceobj.name,
 103                                                     wait=wait,
 104                                                     cmd_prefix=dhclient_cmd_prefix)
 105                             return
 106                         time.sleep(2)
 107
 108         except Exception, e:
 109             self.log_error(str(e), ifaceobj)
 110
 111     def _down_stale_dhcp_config(self, ifaceobj, family, dhclientX_running):
 112         addr_family = ifaceobj.addr_family
 113         try:
 114             if not family in ifaceobj.addr_family and dhclientX_running:
 115                 ifaceobj.addr_family = [family]
 116                 self._dhcp_down(ifaceobj)
 117         except:
 118             pass
 119         finally:
 120             ifaceobj.addr_family = addr_family
 121
 122     def _dhcp_down(self, ifaceobj):
 123         dhclient_cmd_prefix = None
 124         vrf = ifaceobj.get_attr_value_first('vrf')
 125         if (vrf and self.vrf_exec_cmd_prefix and
 126             self.ipcmd.link_exists(vrf)):
 127             dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
 128         if 'inet6' in ifaceobj.addr_family:
 129             self.dhclientcmd.release6(ifaceobj.name, dhclient_cmd_prefix)
 130         if 'inet' in ifaceobj.addr_family:
 131             self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
 132
 133     def _down(self, ifaceobj):
 134         self._dhcp_down(ifaceobj)
 135         self.ipcmd.link_down(ifaceobj.name)
 136
 137     def _query_check(self, ifaceobj, ifaceobjcurr):
 138         status = ifaceStatus.SUCCESS
 139         dhcp_running = False
 140
 141         dhcp_v4 = self.dhclientcmd.is_running(ifaceobjcurr.name)
 142         dhcp_v6 = self.dhclientcmd.is_running6(ifaceobjcurr.name)
 143
 144         if dhcp_v4:
 145             dhcp_running = True
 146             if 'inet' not in ifaceobj.addr_family and not dhcp_v6:
 147                 status = ifaceStatus.ERROR
 148             ifaceobjcurr.addr_method = 'dhcp'
 149         if dhcp_v6:
 150             dhcp_running = True
 151             if 'inet6' not in ifaceobj.addr_family and not dhcp_v4:
 152                 status = ifaceStatus.ERROR
 153             ifaceobjcurr.addr_method = 'dhcp'
 154         ifaceobjcurr.addr_family = ifaceobj.addr_family
 155         if not dhcp_running:
 156             ifaceobjcurr.addr_family = []
 157             status = ifaceStatus.ERROR
 158         ifaceobjcurr.status = status
 159
 160     def _query_running(self, ifaceobjrunning):
 161         if not self.ipcmd.link_exists(ifaceobjrunning.name):
 162             return
 163         if self.dhclientcmd.is_running(ifaceobjrunning.name):
 164             ifaceobjrunning.addr_family.append('inet')
 165             ifaceobjrunning.addr_method = 'dhcp'
 166         if self.dhclientcmd.is_running6(ifaceobjrunning.name):
 167             ifaceobjrunning.addr_family.append('inet6')
 168             ifaceobjrunning.addr_method = 'dhcp6'
 169
 170     _run_ops = {'up' : _up,
 171                'down' : _down,
 172                'pre-down' : _down,
 173                'query-checkcurr' : _query_check,
 174                'query-running' : _query_running }
 175
 176     def get_ops(self):
 177         """ returns list of ops supported by this module """
 178         return self._run_ops.keys()
 179
 180     def _init_command_handlers(self):
 181         if not self.ipcmd:
 182             self.ipcmd = iproute2()
 183
 184     def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
 185         """ run dhcp configuration on the interface object passed as argument
 186
 187         Args:
 188             **ifaceobj** (object): iface object
 189
 190             **operation** (str): any of 'up', 'down', 'query-checkcurr',
 191                                  'query-running'
 192
 193         Kwargs:
 194             **query_ifaceobj** (object): query check ifaceobject. This is only
 195                 valid when op is 'query-checkcurr'. It is an object same as
 196                 ifaceobj, but contains running attribute values and its config
 197                 status. The modules can use it to return queried running state
 198                 of interfaces. status is success if the running state is same
 199                 as user required state in ifaceobj. error otherwise.
 200         """
 201         op_handler = self._run_ops.get(operation)
 202         if not op_handler:
 203             return
 204         try:
 205             if (operation != 'query-running' and
 206                    (ifaceobj.addr_method != 'dhcp' and
 207                        ifaceobj.addr_method != 'dhcp6')):
 208                 return
 209         except:
 210             return
 211         if not self.is_dhcp_allowed_on(ifaceobj, syntax_check=False):
 212             return
 213         self._init_command_handlers()
 214         if operation == 'query-checkcurr':
 215             op_handler(self, ifaceobj, query_ifaceobj)
 216         else:
 217             op_handler(self, ifaceobj)