CumulusNetworks-ifupdown2/addons/vrf.py

#!/usr/bin/python
#
# Copyright 2014 Cumulus Networks, Inc. All rights reserved.
# Author: Roopa Prabhu, roopa@cumulusnetworks.com
#

import os
import atexit
from ifupdown.iface import *
import ifupdownaddons
from ifupdownaddons.modulebase import moduleBase
from ifupdownaddons.bondutil import bondutil
from ifupdownaddons.iproute2 import iproute2

class vrf(moduleBase):
    """  ifupdown2 addon module to configure vrfs """
    _modinfo = { 'mhelp' : 'vrf configuration module',
                    'attrs' : {
                    'vrf-table':
                         {'help' : 'vrf device table id. key to ' +
                                   'creating a vrf device',
                          'example': ['vrf-table-id 1']},
                    'vrf':
                         {'help' : 'vrf the interface is part of.',
                          'example': ['vrf blue']}}}

    iproute2_vrf_filename = '/etc/iproute2/rt_tables.d/ifupdown2.vrf_map'
    iproute2_vrf_filehdr = '# This file is autogenerated by ifupdown2.\n' + \
                           '# It contains the vrf name to table mapping.\n' + \
                           '# Reserved table range 150-200\n'
    vrf_table_reserved_start = 150
    vrf_table_reserved_end = 200

    def __init__(self, *args, **kargs):
        ifupdownaddons.modulebase.moduleBase.__init__(self, *args, **kargs)
        self.ipcmd = None
        self.bondcmd = None
        try:
            ip_rules = self.exec_command('/sbin/ip rule show').splitlines()
            self.ip_rule_cache = [' '.join(r.split()) for r in ip_rules]
        except Exception, e:
            self.ip_rule_cache = []
            self.logger.warn('%s' %str(e))

        try:
            ip_rules = self.exec_command('/sbin/ip -6 rule show').splitlines()
            self.ip6_rule_cache = [' '.join(r.split()) for r in ip_rules]
        except Exception, e:
            self.ip6_rule_cache = []
            self.logger.warn('%s' %str(e))

        #self.logger.debug("vrf: ip rule cache")
        #self.logger.info(self.ip_rule_cache)

        #self.logger.info("vrf: ip -6 rule cache")
        #self.logger.info(self.ip6_rule_cache)

        # XXX: check for vrf reserved overlap in /etc/iproute2/rt_tables
        self.iproute2_vrf_map = {}
        # read or create /etc/iproute2/rt_tables.d/ifupdown2.vrf_map
        if os.path.exists(self.iproute2_vrf_filename):
            self.vrf_map_fd = open(self.iproute2_vrf_filename, 'a+')
            lines = self.vrf_map_fd.readlines()
            for l in lines:
                l = l.strip()
                if l[0] == '#':
                    continue
                try:
                    (table, vrf_name) = l.strip().split()
                    self.iproute2_vrf_map[table] = vrf_name
                except Exception, e:
                    self.logger.info('vrf: iproute2_vrf_map: unable to parse %s'
                                     %l)
                    pass
        #self.logger.info("vrf: dumping iproute2_vrf_map")
        #self.logger.info(self.iproute2_vrf_map)

        # purge vrf table entries that are not around
        iproute2_vrf_map_pruned = {}
        for t, v in self.iproute2_vrf_map.iteritems():
            if os.path.exists('/sys/class/net/%s' %v):
                iproute2_vrf_map_pruned[t] = v
            else:
                try:
                    # cleanup rules
                    self._del_vrf_rules(v, t)
                except Exception:
                    pass
        self.iproute2_vrf_map = iproute2_vrf_map_pruned

        last_used_vrf_table = self.vrf_table_reserved_start
        for t in range(self.vrf_table_reserved_start,
                       self.vrf_table_reserved_end):
            last_used_vrf_table = t
            if not self.iproute2_vrf_map.get(t):
                break
        self.last_used_vrf_table = last_used_vrf_table
        self.iproute2_write_vrf_map = False
        atexit.register(self.iproute2_vrf_map_write)

    def iproute2_vrf_map_write(self):
        if not self.iproute2_write_vrf_map:
            return
        self.logger.info('vrf: writing table map to %s'
                         %self.iproute2_vrf_filename)
        with open(self.iproute2_vrf_filename, 'w') as f:
            f.write(self.iproute2_vrf_filehdr)
            for t, v in self.iproute2_vrf_map.iteritems():
                f.write('%s %s\n' %(t, v))

    def _is_vrf(self, ifaceobj):
        if ifaceobj.get_attr_value_first('vrf-table'):
            return True
        return False

    def get_dependent_ifacenames(self, ifaceobj, ifacenames_all=None):
        """ Returns list of interfaces dependent on ifaceobj """

        vrf_iface_name = ifaceobj.get_attr_value_first('vrf')
        if not vrf_iface_name:
            return None
        return [vrf_iface_name]

    def get_dependent_ifacenames_running(self, ifaceobj):
        return None

    def _get_iproute2_vrf_table(self, vrf_dev_name):
        for t, v in self.iproute2_vrf_map.iteritems():
            if v == vrf_dev_name:
                return t
        return None

    def _get_avail_vrf_table_id(self):
        for t in range(self.last_used_vrf_table + 1,
                       self.vrf_table_reserved_end):
            if not self.iproute2_vrf_map.get(t):
                self.last_used_vrf_table = t
                return t
        return None

    def _iproute2_vrf_table_entry_add(self, vrf_dev_name, table_id):
        self.iproute2_vrf_map[table_id] = vrf_dev_name
        self.iproute2_write_vrf_map = True

    def _iproute2_vrf_table_entry_del(self, table_id):
        try:
            del self.iproute2_vrf_map[table_id]
            self.iproute2_write_vrf_map = True
        except Exception, e:
            self.logger.info('vrf: iproute2 vrf map del failed for %d (%s)'
                             %(table_id, str(e)))
            pass

    def _up_vrf_slave(self, ifaceobj, vrf):
        try:
            self.ipcmd.link_set(ifaceobj.name, 'master', vrf)
        except Exception, e:
            self.logger.warn('%s: %s' %(ifaceobj.name, str(e)))

    def _del_vrf_rules(self, vrf_dev_name, vrf_table):
        pref = 200
        ip_rule_out_format = '%s: from all %s %s lookup %s'
        ip_rule_cmd = 'ip %s rule del pref %s %s %s table %s' 

        rule = ip_rule_out_format %(pref, 'oif', vrf_dev_name, vrf_table)
        if rule in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('', pref, 'oif', vrf_dev_name, vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'iif', vrf_dev_name, vrf_table)
        if rule in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('', pref, 'iif', vrf_dev_name, vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'oif', vrf_dev_name, vrf_table)
        if rule in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('-6', pref, 'oif', vrf_dev_name,
                                     vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'iif', vrf_dev_name, vrf_table)
        if rule in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('-6', pref, 'iif', vrf_dev_name,
                                     vrf_table)
            self.exec_command(rule_cmd)

    def _add_vrf_rules(self, vrf_dev_name, vrf_table):
        pref = 200
        ip_rule_out_format = '%s: from all %s %s lookup %s'
        ip_rule_cmd = 'ip %s rule add pref %s %s %s table %s' 

        rule = ip_rule_out_format %(pref, 'oif', vrf_dev_name, vrf_table)
        if rule not in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('', pref, 'oif', vrf_dev_name, vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'iif', vrf_dev_name, vrf_table)
        if rule not in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('', pref, 'iif', vrf_dev_name, vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'oif', vrf_dev_name, vrf_table)
        if rule not in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('-6', pref, 'oif', vrf_dev_name,
                                     vrf_table)
            self.exec_command(rule_cmd)

        rule = ip_rule_out_format %(pref, 'iif', vrf_dev_name, vrf_table)
        if rule not in self.ip_rule_cache:
            rule_cmd = ip_rule_cmd %('-6', pref, 'iif', vrf_dev_name,
                                     vrf_table)
            self.exec_command(rule_cmd)


    def _up_vrf_dev(self, ifaceobj, vrf_table):
        if vrf_table == 'auto':
            vrf_table = _get_avail_vrf_table_id(ifaceobj.name)

        try:
            if not self.ipcmd.link_exists(ifaceobj.name):
                self.ipcmd.link_create(ifaceobj.name, 'vrf',
                                       {'table' : '%s' %vrf_table})
            self._iproute2_vrf_table_entry_add(ifaceobj.name, vrf_table)
            self._add_vrf_rules(ifaceobj.name, vrf_table)
        except Exception, e:
            self.logger.warn('%s: %s' %(ifaceobj.name, str(e)))

    def _up(self, ifaceobj):
        try:
            vrf_table = ifaceobj.get_attr_value_first('vrf-table')
            if vrf_table:
                self._up_vrf_dev(ifaceobj, vrf_table)
            else:
                vrf = ifaceobj.get_attr_value_first('vrf')
                if vrf:
                    self._up_vrf_slave(ifaceobj, vrf)
        except Exception, e:
            self.log_error(str(e))

    def _down_vrf_dev(self, ifaceobj, vrf_table):
        if vrf_table == 'auto':
            vrf_table = self._get_iproute2_vrf_table(ifaceobj.name)
        try:
            self.ipcmd.link_delete(ifaceobj.name)
            self._iproute2_vrf_table_entry_del(vrf_table)
            self._del_vrf_rules(ifaceobj.name, vrf_table)
        except Exception, e:
            self.logger.warn('%s: %s' %(ifaceobj.name, str(e)))

    def _down_vrf_slave(self, ifaceobj, vrf):
        try:
            self.ipcmd.link_set(ifaceobj.name, 'nomaster')
        except Exception, e:
            self.logger.warn('%s: %s' %(ifaceobj.name, str(e)))

    def _down(self, ifaceobj):
        try:
            vrf_table = ifaceobj.get_attr_value_first('vrf-table')
            if vrf_table:
                self._down_vrf_dev(ifaceobj, vrf_table)
            else:
                vrf = ifaceobj.get_attr_value_first('vrf')
                if vrf:
                    self._down_vrf_slave(ifaceobj, vrf)
        except Exception, e:
            self.log_warn(str(e))

    def _query_check_vrf_slave(self, ifaceobj, ifaceobjcurr, vrf):
        try:
            master = self.ipcmd.link_get_master(ifacename)
            if not master or master != vrf:
                ifaceobjcurr.update_config_with_status('vrf', master, 1)
            else:
                ifaceobjcurr.update_config_with_status('vrf', master, 0)
        except Exception, e:
            self.log_warn(str(e))

    def _query_check_vrf_dev(self, ifaceobj, ifaceobjcurr, vrf_table):
        try:
            if not self.ipcmd.link_exists(ifaceobj.name):
                self.logger.info('%s: vrf: does not exist' %(ifaceobj.name))
                return
            if vrf_table == 'auto':
                config_table = self._get_iproute2_vrf_table(ifaceobj.name)
            else:
                config_table = vrf_table
            vrfdev_attrs = self.ipcmd.link_get_linkinfo_attrs(ifaceobj.name)
            if not vrfdev_attrs:
                ifaceobjcurr.update_config_with_status('vrf-table', 'None', 1)
                return
            running_table = vrfdev_attrs.get('table')
            if not running_table:
                ifaceobjcurr.update_config_with_status('vrf-table', 'None', 1)
                return
            if config_table != running_table:
                ifaceobjcurr.update_config_with_status('vrf-table',
                                                       running_table, 1)
            else:
                ifaceobjcurr.update_config_with_status('vrf-table',
                                                       running_table, 0)
        except Exception, e:
            self.log_warn(str(e))

    def _query_check(self, ifaceobj, ifaceobjcurr):
        try:
            vrf_table = ifaceobj.get_attr_value_first('vrf-table')
            if vrf_table:
                self._query_check_vrf_dev(ifaceobj, ifaceobjcurr, vrf_table)
            else:
                vrf = ifaceobj.get_attr_value_first('vrf')
                if vrf:
                    self._query_check_vrf_slave(ifaceobj, ifaceobjcurr, vrf)
        except Exception, e:
            self.log_warn(str(e))

    def _query_running(self, ifaceobjrunning):
        try:
            kind = self.ipcmd.link_get_kind(ifaceobjrunning.name)
            if kind == 'vrf':
                vrfdev_attrs = self.ipcmd.link_get_linkinfo_attrs(ifaceobj.name)
                if vrfdev_attrs:
                    running_table = vrfdev_attrs.get('table')
                    if running_table:
                        ifaceobjrunning.update_config('vrf-table',
                                                      running_table)
            elif kind == 'vrf_slave':
                vrf = self.link_get_master(ifaceobjrunning.name)
                if vrf:
                    ifaceobjrunning.update_config('vrf', vrf)
        except Exception, e:
            self.log_warn(str(e))

    _run_ops = {'pre-up' : _up,
               'post-down' : _down,
               'query-running' : _query_running,
               'query-checkcurr' : _query_check}

    def get_ops(self):
        """ returns list of ops supported by this module """
        return self._run_ops.keys()

    def _init_command_handlers(self):
        flags = self.get_flags()
        if not self.ipcmd:
            self.ipcmd = iproute2(**flags)
        if not self.bondcmd:
            self.bondcmd = bondutil(**flags)

    def run(self, ifaceobj, operation, query_ifaceobj=None, **extra_args):
        """ run bond configuration on the interface object passed as argument

        Args:
            **ifaceobj** (object): iface object

            **operation** (str): any of 'pre-up', 'post-down', 'query-checkcurr',
                'query-running'

        Kwargs:
            **query_ifaceobj** (object): query check ifaceobject. This is only
                valid when op is 'query-checkcurr'. It is an object same as
                ifaceobj, but contains running attribute values and its config
                status. The modules can use it to return queried running state
                of interfaces. status is success if the running state is same
                as user required state in ifaceobj. error otherwise.
        """
        op_handler = self._run_ops.get(operation)
        if not op_handler:
            return
        self._init_command_handlers()
        if operation == 'query-checkcurr':
            op_handler(self, ifaceobj, query_ifaceobj)
        else:
            op_handler(self, ifaceobj)