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         if self.dhclientcmd.is_running(ifaceobj.name) or \
  42                self.dhclientcmd.is_running6(ifaceobj.name):
  43             self.logger.info('dhclient already running on %s.  Not restarting.' % \
  44                              ifaceobj.name)
  45             return
  46         try:
  47             dhclient_cmd_prefix = None
  48             dhcp_wait = policymanager.policymanager_api.get_attr_default(
  49                 module_name=self.__class__.__name__, attr='dhcp-wait')
  50             wait = not str(dhcp_wait).lower() == "no"
  51             vrf = ifaceobj.get_attr_value_first('vrf')
  52             if (vrf and self.vrf_exec_cmd_prefix and
  53                 self.ipcmd.link_exists(vrf)):
  54                 dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
  55
  56             if 'inet' in ifaceobj.addr_family:
  57                 # First release any existing dhclient processes
  58                 try:
  59                     if not ifupdownflags.flags.PERFMODE:
  60                         self.dhclientcmd.stop(ifaceobj.name)
  61                 except:
  62                     pass
  63                 self.dhclientcmd.start(ifaceobj.name, wait=wait,
  64                                        cmd_prefix=dhclient_cmd_prefix)
  65             if 'inet6' in ifaceobj.addr_family:
  66                 accept_ra = ifaceobj.get_attr_value_first('accept_ra')
  67                 if accept_ra:
  68                     # XXX: Validate value
  69                     self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  70                             '.accept_ra', accept_ra)
  71                 autoconf = ifaceobj.get_attr_value_first('autoconf')
  72                 if autoconf:
  73                     # XXX: Validate value
  74                     self.sysctl_set('net.ipv6.conf.%s' %ifaceobj.name +
  75                             '.autoconf', autoconf)
  76                     try:
  77                         self.dhclientcmd.stop6(ifaceobj.name)
  78                     except:
  79                         pass
  80                 #add delay before starting IPv6 dhclient to
  81                 #make sure the configured interface/link is up.
  82                 time.sleep(2)
  83                 timeout = 10
  84                 while timeout:
  85                     timeout -= 2
  86                     addr_output = utils.exec_command('ip -6 addr show %s'
  87                                                      % ifaceobj.name)
  88                     r = re.search('inet6 .* scope link', addr_output)
  89                     if r:
  90                         self.dhclientcmd.start6(ifaceobj.name,
  91                                                 wait=wait,
  92                                                 cmd_prefix=dhclient_cmd_prefix)
  93                         return
  94                     time.sleep(2)
  95
  96
  97         except Exception, e:
  98             self.log_error(str(e), ifaceobj)
  99
 100     def _down(self, ifaceobj):
 101         dhclient_cmd_prefix = None
 102         vrf = ifaceobj.get_attr_value_first('vrf')
 103         if (vrf and self.vrf_exec_cmd_prefix and
 104             self.ipcmd.link_exists(vrf)):
 105             dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
 106         if 'inet6' in ifaceobj.addr_family:
 107             self.dhclientcmd.release6(ifaceobj.name, dhclient_cmd_prefix)
 108         if 'inet' in ifaceobj.addr_family:
 109             self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
 110         self.ipcmd.link_down(ifaceobj.name)
 111
 112     def _query_check(self, ifaceobj, ifaceobjcurr):
 113         status = ifaceStatus.SUCCESS
 114         dhcp_running = False
 115
 116         dhcp_v4 = self.dhclientcmd.is_running(ifaceobjcurr.name)
 117         dhcp_v6 = self.dhclientcmd.is_running6(ifaceobjcurr.name)
 118
 119         if dhcp_v4:
 120             dhcp_running = True
 121             if 'inet' not in ifaceobj.addr_family and not dhcp_v6:
 122                 status = ifaceStatus.ERROR
 123             ifaceobjcurr.addr_method = 'dhcp'
 124         if dhcp_v6:
 125             dhcp_running = True
 126             if 'inet6' not in ifaceobj.addr_family and not dhcp_v4:
 127                 status = ifaceStatus.ERROR
 128             ifaceobjcurr.addr_method = 'dhcp'
 129         ifaceobjcurr.addr_family = ifaceobj.addr_family
 130         if not dhcp_running:
 131             ifaceobjcurr.addr_family = []
 132             status = ifaceStatus.ERROR
 133         ifaceobjcurr.status = status
 134
 135     def _query_running(self, ifaceobjrunning):
 136         if not self.ipcmd.link_exists(ifaceobjrunning.name):
 137             return
 138         if self.dhclientcmd.is_running(ifaceobjrunning.name):
 139             ifaceobjrunning.addr_family.append('inet')
 140             ifaceobjrunning.addr_method = 'dhcp'
 141         if self.dhclientcmd.is_running6(ifaceobjrunning.name):
 142             ifaceobjrunning.addr_family.append('inet6')
 143             ifaceobjrunning.addr_method = 'dhcp6'
 144
 145     _run_ops = {'up' : _up,
 146                'down' : _down,
 147                'pre-down' : _down,
 148                'query-checkcurr' : _query_check,
 149                'query-running' : _query_running }
 150
 151     def get_ops(self):
 152         """ returns list of ops supported by this module """
 153         return self._run_ops.keys()
 154
 155     def _init_command_handlers(self):
 156         if not self.ipcmd:
 157             self.ipcmd = iproute2()
 158
 159     def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
 160         """ run dhcp configuration on the interface object passed as argument
 161
 162         Args:
 163             **ifaceobj** (object): iface object
 164
 165             **operation** (str): any of 'up', 'down', 'query-checkcurr',
 166                                  'query-running'
 167
 168         Kwargs:
 169             **query_ifaceobj** (object): query check ifaceobject. This is only
 170                 valid when op is 'query-checkcurr'. It is an object same as
 171                 ifaceobj, but contains running attribute values and its config
 172                 status. The modules can use it to return queried running state
 173                 of interfaces. status is success if the running state is same
 174                 as user required state in ifaceobj. error otherwise.
 175         """
 176         op_handler = self._run_ops.get(operation)
 177         if not op_handler:
 178             return
 179         try:
 180             if (operation != 'query-running' and
 181                    (ifaceobj.addr_method != 'dhcp' and
 182                        ifaceobj.addr_method != 'dhcp6')):
 183                 return
 184         except:
 185             return
 186         if not self.is_dhcp_allowed_on(ifaceobj, syntax_check=False):
 187             return
 188         self._init_command_handlers()
 189         if operation == 'query-checkcurr':
 190             op_handler(self, ifaceobj, query_ifaceobj)
 191         else:
 192             op_handler(self, ifaceobj)