# Copyright 2019 VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/>.

import os
import re
import jinja2
import json
import glob
import time
from copy import deepcopy

import vyos.interfaces

from vyos.validate import *
from vyos.config import Config
from vyos import ConfigError

from ipaddress import IPv4Network, IPv6Address
from netifaces import ifaddresses, AF_INET, AF_INET6
from subprocess import Popen, PIPE, STDOUT
from time import sleep
from os.path import isfile
from tabulate import tabulate
from hurry.filesize import size,alternative
from datetime import timedelta

dhclient_base = r'/var/lib/dhcp/dhclient_'
dhcp_cfg = """
# generated by ifconfig.py
option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
timeout 60;
retry 300;

interface "{{ intf }}" {
    send host-name "{{ hostname }}";
    {% if client_id -%}
    send dhcp-client-identifier "{{ client_id }}";
    {% endif -%}
    {% if vendor_class_id -%}
    send vendor-class-identifier "{{ vendor_class_id }}";
    {% endif -%}
    request subnet-mask, broadcast-address, routers, domain-name-servers,
        rfc3442-classless-static-routes, domain-name, interface-mtu;
    require subnet-mask;
}

"""

dhcpv6_cfg = """
# generated by ifconfig.py
interface "{{ intf }}" {
    request routers, domain-name-servers, domain-name;
}

"""

class Interface:
    options = []
    required = []
    default = {
        'type': '',
    }

    def __init__(self, ifname, **kargs):
        """
        This is the base interface class which supports basic IP/MAC address
        operations as well as DHCP(v6). Other interface which represent e.g.
        and ethernet bridge are implemented as derived classes adding all
        additional functionality.

        For creation you will need to provide the interface type, otherwise
        the existing interface is used

        DEBUG:
        This class has embedded debugging (print) which can be enabled by
        creating the following file:
        vyos@vyos# touch /tmp/vyos.ifconfig.debug

        Example:
        >>> from vyos.ifconfig import Interface
        >>> i = Interface('eth0')
        """

        self.config = deepcopy(self.default)
        self.config['ifname'] = ifname

        for k in kargs:
            if k not in self.options:
                raise ConfigError('invalid option {} for {}'.format(k,self.__class__))
            self.config[k] = kargs[k]

        for k in self.required:
            if k not in kargs:
                raise ConfigError('missing required option {} for {}'.format(k,self.__class__))

        if not os.path.exists('/sys/class/net/{}'.format(self.config['ifname'])):
            if not self.config['type']:
                raise Exception('interface "{}" not found'.format(self.config['ifname']))
            self._create()

        # per interface DHCP config files
        self._dhcp_cfg_file = dhclient_base + self.config['ifname'] + '.conf'
        self._dhcp_pid_file = dhclient_base + self.config['ifname'] + '.pid'
        self._dhcp_lease_file = dhclient_base + self.config['ifname'] + '.leases'

        # per interface DHCPv6 config files
        self._dhcpv6_cfg_file = dhclient_base + self.config['ifname'] + '.v6conf'
        self._dhcpv6_pid_file = dhclient_base + self.config['ifname'] + '.v6pid'
        self._dhcpv6_lease_file = dhclient_base + self.config['ifname'] + '.v6leases'

        # DHCP options
        self._dhcp_options = {
            'intf' : self.config['ifname'],
            'hostname' : '',
            'client_id' : '',
            'vendor_class_id' : ''
        }

        # DHCPv6 options
        self._dhcpv6_options = {
            'intf' : self.config['ifname'],
            'dhcpv6_prm_only' : False,
            'dhcpv6_temporary' : False
        }

        # list of assigned IP addresses
        self._addr = []

    def _create(self):
        cmd = 'ip link add dev {ifname} type {type}'.format(**self.config)
        self._cmd(cmd)

    def _debug_msg(self, msg):
        if os.path.isfile('/tmp/vyos.ifconfig.debug'):
            print('DEBUG/{:<6} {}'.format(self.config['ifname'], msg))

    def _cmd(self, command):
        p = Popen(command, stdout=PIPE, stderr=STDOUT, shell=True)
        tmp = p.communicate()[0].strip()
        self._debug_msg("cmd '{}'".format(command))
        if tmp.decode():
            self._debug_msg("returned:\n{}".format(tmp.decode()))

        # do we need some error checking code here?
        return tmp.decode()

    def _read_sysfs(self, filename):
        """
        Provide a single primitive w/ error checking for reading from sysfs.
        """
        value = None
        with open(filename, 'r') as f:
            value = f.read().rstrip('\n')

        self._debug_msg("read '{}' < '{}'".format(value, filename))
        return value

    def _write_sysfs(self, filename, value):
        """
        Provide a single primitive w/ error checking for writing to sysfs.
        """
        self._debug_msg("write '{}' > '{}'".format(value, filename))
        with open(filename, 'w') as f:
            f.write(str(value))

        return None

    def remove(self):
        """
        Remove interface from operating system. Removing the interface
        deconfigures all assigned IP addresses and clear possible DHCP(v6)
        client processes.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> i = Interface('eth0')
        >>> i.remove()
        """
        # stop DHCP(v6) if running
        self._del_dhcp()
        self._del_dhcpv6()

        # remove all assigned IP addresses from interface - this is a bit redundant
        # as the kernel will remove all addresses on interface deletion, but we
        # can not delete ALL interfaces, see below
        for addr in self.get_addr():
            self.del_addr(addr)

        # ---------------------------------------------------------------------
        # A code refactoring is required as this type check is present as 
        # Interface implement behaviour for one of it's sub-class.

        # It is required as the current pattern for vlan is:
        # Interface('name').remove() to delete an interface
        # The code should be modified to have a class method called connect and
        # have Interface.connect('name').remove()

        # each subclass should register within Interface the pattern for that
        # interface ie: (ethX, etc.) and use this to create an instance of
        # the right class (EthernetIf, ...)

        # Ethernet interfaces can not be removed
        if self.__class__ == EthernetIf:
            return

        # ---------------------------------------------------------------------

        self._delete()

    def _delete(self):
        # NOTE (Improvement):
        # after interface removal no other commands should be allowed
        # to be called and instead should raise an Exception:
        cmd = 'ip link del dev {}'.format(self.config['ifname'])
        return self._cmd(cmd)

    def get_mtu(self):
        """
        Get/set interface mtu in bytes.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').get_mtu()
        '1500'
        """
        return self._read_sysfs('/sys/class/net/{}/mtu'
                                .format(self.config['ifname']))

    def set_mtu(self, mtu):
        """
        Get/set interface mtu in bytes.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_mtu(1400)
        >>> Interface('eth0').get_mtu()
        '1400'
        """
        if mtu < 68 or mtu > 9000:
            raise ValueError('Invalid MTU size: "{}"'.format(mru))

        return self._write_sysfs('/sys/class/net/{}/mtu'
                                 .format(self.config['ifname']), mtu)

    def set_mac(self, mac):
        """
        Set interface MAC (Media Access Contrl) address to given value.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_mac('00:50:ab:cd:ef:01')
        """
        # on interface removal (ethernet) an empty string is passed - ignore it
        if not mac:
            return None

        # a mac address consits out of 6 octets
        octets = len(mac.split(':'))
        if octets != 6:
            raise ValueError('wrong number of MAC octets: {} '.format(octets))

        # validate against the first mac address byte if it's a multicast
        # address
        if int(mac.split(':')[0], 16) & 1:
            raise ValueError('{} is a multicast MAC address'.format(mac))

        # overall mac address is not allowed to be 00:00:00:00:00:00
        if sum(int(i, 16) for i in mac.split(':')) == 0:
            raise ValueError('00:00:00:00:00:00 is not a valid MAC address')

        # check for VRRP mac address
        if mac.split(':')[0] == '0' and addr.split(':')[1] == '0' and mac.split(':')[2] == '94' and mac.split(':')[3] == '0' and mac.split(':')[4] == '1':
            raise ValueError('{} is a VRRP MAC address'.format(mac))

        # Assemble command executed on system. Unfortunately there is no way
        # of altering the MAC address via sysfs
        cmd = 'ip link set dev {} address {}'.format(self.config['ifname'], mac)
        return self._cmd(cmd)


    def set_arp_cache_tmo(self, tmo):
        """
        Set ARP cache timeout value in seconds. Internal Kernel representation
        is in milliseconds.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_arp_cache_tmo(40)
        """
        return self._write_sysfs('/proc/sys/net/ipv4/neigh/{0}/base_reachable_time_ms'
                                 .format(self.config['ifname']), (int(tmo) * 1000))

    def set_arp_filter(self, arp_filter):
        """
        Filter ARP requests

        1 - Allows you to have multiple network interfaces on the same
            subnet, and have the ARPs for each interface be answered
            based on whether or not the kernel would route a packet from
            the ARP'd IP out that interface (therefore you must use source
            based routing for this to work). In other words it allows control
            of which cards (usually 1) will respond to an arp request.

        0 - (default) The kernel can respond to arp requests with addresses
            from other interfaces. This may seem wrong but it usually makes
            sense, because it increases the chance of successful communication.
            IP addresses are owned by the complete host on Linux, not by
            particular interfaces. Only for more complex setups like load-
            balancing, does this behaviour cause problems.
        """
        if int(arp_filter) >= 0 and int(arp_filter) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{0}/arp_filter'
                                     .format(self.config['ifname']), arp_filter)
        else:
           raise ValueError("Value out of range")

    def set_arp_accept(self, arp_accept):
        """
        Define behavior for gratuitous ARP frames who's IP is not
        already present in the ARP table:
        0 - don't create new entries in the ARP table
        1 - create new entries in the ARP table

        Both replies and requests type gratuitous arp will trigger the
        ARP table to be updated, if this setting is on.

        If the ARP table already contains the IP address of the
        gratuitous arp frame, the arp table will be updated regardless
        if this setting is on or off.
        """
        if int(arp_accept) >= 0 and int(arp_accept) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{0}/arp_accept'
                                     .format(self.config['ifname']), arp_accept)
        else:
           raise ValueError("Value out of range")

    def set_arp_announce(self, arp_announce):
        """
        Define different restriction levels for announcing the local
        source IP address from IP packets in ARP requests sent on
        interface:
        0 - (default) Use any local address, configured on any interface
        1 - Try to avoid local addresses that are not in the target's
            subnet for this interface. This mode is useful when target
            hosts reachable via this interface require the source IP
            address in ARP requests to be part of their logical network
            configured on the receiving interface. When we generate the
            request we will check all our subnets that include the
            target IP and will preserve the source address if it is from
            such subnet.

        Increasing the restriction level gives more chance for
        receiving answer from the resolved target while decreasing
        the level announces more valid sender's information.
        """
        if int(arp_announce) >= 0 and int(arp_announce) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{0}/arp_announce'
                                     .format(self.config['ifname']), arp_announce)
        else:
           raise ValueError("Value out of range")

    def set_arp_ignore(self, arp_ignore):
        """
        Define different modes for sending replies in response to received ARP
        requests that resolve local target IP addresses:

        0 - (default): reply for any local target IP address, configured
            on any interface
        1 - reply only if the target IP address is local address
            configured on the incoming interface
        """
        if int(arp_ignore) >= 0 and int(arp_ignore) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{0}/arp_ignore'
                                     .format(self.config['ifname']), arp_ignore)
        else:
           raise ValueError("Value out of range")

    def set_link_detect(self, link_filter):
        """
        Configure kernel response in packets received on interfaces that are 'down'

        0 - Allow packets to be received for the address on this interface
            even if interface is disabled or no carrier.

        1 - Ignore packets received if interface associated with the incoming
            address is down.

        2 - Ignore packets received if interface associated with the incoming
            address is down or has no carrier.

        Default value is 0. Note that some distributions enable it in startup
        scripts.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_link_detect(1)
        """
        sysfs_file = '/proc/sys/net/ipv4/conf/{0}/link_filter'.format(self.config['ifname'])
        if os.path.exists(sysfs_file):
            if int(link_filter) >= 0 and int(link_filter) <= 2:
                return self._write_sysfs(sysfs_file, link_filter)
            else:
                raise ValueError("Value out of range")

    def set_alias(self, ifalias=None):
        """
        Set interface alias name used by e.g. SNMP

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_alias('VyOS upstream interface')

        to clear alias e.g. delete it use:

        >>> Interface('eth0').set_ifalias('')
        """
        if not ifalias:
            # clear interface alias
            ifalias = '\0'

        self._write_sysfs('/sys/class/net/{}/ifalias'
                          .format(self.config['ifname']), ifalias)

    def get_state(self):
        """
        Enable (up) / Disable (down) an interface

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').get_state()
        'up'
        """
        cmd = 'ip -json link show dev {}'.format(self.config['ifname'])
        tmp = self._cmd(cmd)
        out = json.loads(tmp)
        return out[0]['operstate'].lower()

    def set_state(self, state):
        """
        Enable (up) / Disable (down) an interface

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_state('down')
        >>> Interface('eth0').get_state()
        'down'
        """
        if state not in ['up', 'down']:
            raise ValueError('state must be "up" or "down"')

        # Assemble command executed on system. Unfortunately there is no way
        # to up/down an interface via sysfs
        cmd = 'ip link set dev {} {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)

    def set_proxy_arp(self, enable):
        """
        Set per interface proxy ARP configuration

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_proxy_arp(1)
        """
        if int(enable) >= 0 and int(enable) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{}/proxy_arp'
                                     .format(self.config['ifname']), enable)
        else:
            raise ValueError("Value out of range")

    def set_proxy_arp_pvlan(self, enable):
        """
        Private VLAN proxy arp.
        Basically allow proxy arp replies back to the same interface
        (from which the ARP request/solicitation was received).

        This is done to support (ethernet) switch features, like RFC
        3069, where the individual ports are NOT allowed to
        communicate with each other, but they are allowed to talk to
        the upstream router.  As described in RFC 3069, it is possible
        to allow these hosts to communicate through the upstream
        router by proxy_arp'ing. Don't need to be used together with
        proxy_arp.

        This technology is known by different names:
        In RFC 3069 it is called VLAN Aggregation.
        Cisco and Allied Telesyn call it Private VLAN.
        Hewlett-Packard call it Source-Port filtering or port-isolation.
        Ericsson call it MAC-Forced Forwarding (RFC Draft).

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_proxy_arp_pvlan(1)
        """
        if int(enable) >= 0 and int(enable) <= 1:
            return self._write_sysfs('/proc/sys/net/ipv4/conf/{}/proxy_arp_pvlan'
                                     .format(self.config['ifname']), enable)
        else:
            raise ValueError("Value out of range")

    def get_addr(self):
        """
        Retrieve assigned IPv4 and IPv6 addresses from given interface.
        This is done using the netifaces and ipaddress python modules.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').get_addrs()
        ['172.16.33.30/24', 'fe80::20c:29ff:fe11:a174/64']
        """

        ipv4 = []
        ipv6 = []

        if AF_INET in ifaddresses(self.config['ifname']).keys():
            for v4_addr in ifaddresses(self.config['ifname'])[AF_INET]:
                # we need to manually assemble a list of IPv4 address/prefix
                prefix = '/' + \
                    str(IPv4Network('0.0.0.0/' + v4_addr['netmask']).prefixlen)
                ipv4.append(v4_addr['addr'] + prefix)

        if AF_INET6 in ifaddresses(self.config['ifname']).keys():
            for v6_addr in ifaddresses(self.config['ifname'])[AF_INET6]:
                # Note that currently expanded netmasks are not supported. That means
                # 2001:db00::0/24 is a valid argument while 2001:db00::0/ffff:ff00:: not.
                # see https://docs.python.org/3/library/ipaddress.html
                bits = bin(
                    int(v6_addr['netmask'].replace(':', ''), 16)).count('1')
                prefix = '/' + str(bits)

                # we alsoneed to remove the interface suffix on link local
                # addresses
                v6_addr['addr'] = v6_addr['addr'].split('%')[0]
                ipv6.append(v6_addr['addr'] + prefix)

        return ipv4 + ipv6

    def add_addr(self, addr):
        """
        Add IP(v6) address to interface. Address is only added if it is not
        already assigned to that interface.

        addr: can be an IPv4 address, IPv6 address, dhcp or dhcpv6!
              IPv4: add IPv4 address to interface
              IPv6: add IPv6 address to interface
              dhcp: start dhclient (IPv4) on interface
              dhcpv6: start dhclient (IPv6) on interface

        Example:
        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.add_addr('192.0.2.1/24')
        >>> j.add_addr('2001:db8::ffff/64')
        >>> j.get_addr()
        ['192.0.2.1/24', '2001:db8::ffff/64']
        """

        # cache new IP address which is assigned to interface
        self._addr.append(addr)

        # we can not have both DHCP and static IPv4 addresses assigned to an interface
        if 'dhcp' in self._addr:
            for addr in self._addr:
                # do not change below 'if' ordering esle you will get an exception as:
                #   ValueError: 'dhcp' does not appear to be an IPv4 or IPv6 address
                if addr != 'dhcp' and is_ipv4(addr):
                    raise ConfigError("Can't configure both static IPv4 and DHCP address on the same interface")

        if addr == 'dhcp':
            self._set_dhcp()
        elif addr == 'dhcpv6':
            self._set_dhcpv6()
        else:
            if not is_intf_addr_assigned(self.config['ifname'], addr):
                cmd = 'ip addr add "{}" dev "{}"'.format(addr, self.config['ifname'])
                return self._cmd(cmd)

    def del_addr(self, addr):
        """
        Delete IP(v6) address to interface. Address is only added if it is
        assigned to that interface.

        addr: can be an IPv4 address, IPv6 address, dhcp or dhcpv6!
              IPv4: delete IPv4 address from interface
              IPv6: delete IPv6 address from interface
              dhcp: stop dhclient (IPv4) on interface
              dhcpv6: stop dhclient (IPv6) on interface

        Example:
        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.add_addr('2001:db8::ffff/64')
        >>> j.add_addr('192.0.2.1/24')
        >>> j.get_addr()
        ['192.0.2.1/24', '2001:db8::ffff/64']
        >>> j.del_addr('192.0.2.1/24')
        >>> j.get_addr()
        ['2001:db8::ffff/64']
        """
        if addr == 'dhcp':
            self._del_dhcp()
        elif addr == 'dhcpv6':
            self._del_dhcpv6()
        else:
            if is_intf_addr_assigned(self.config['ifname'], addr):
                cmd = 'ip addr del "{}" dev "{}"'.format(addr, self.config['ifname'])
                return self._cmd(cmd)


    def get_dhcp_options(self):
        """
        Return dictionary with supported DHCP options.

        Dictionary should be altered and send back via set_dhcp_options()
        so those options are applied when DHCP is run.
        """
        return self._dhcp_options

    def set_dhcp_options(self, options):
        """
        Store new DHCP options used by next run of DHCP client.
        """
        self._dhcp_options = options

    def get_dhcpv6_options(self):
        """
        Return dictionary with supported DHCPv6 options.

        Dictionary should be altered and send back via set_dhcp_options()
        so those options are applied when DHCP is run.
        """
        return self._dhcpv6_options

    def set_dhcpv6_options(self, options):
        """
        Store new DHCP options used by next run of DHCP client.
        """
        self._dhcpv6_options = options

    # replace dhcpv4/v6 with systemd.networkd?
    def _set_dhcp(self):
        """
        Configure interface as DHCP client. The dhclient binary is automatically
        started in background!

        Example:

        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.set_dhcp()
        """

        dhcp = self.get_dhcp_options()
        if not dhcp['hostname']:
            # read configured system hostname.
            # maybe change to vyos hostd client ???
            with open('/etc/hostname', 'r') as f:
                dhcp['hostname'] = f.read().rstrip('\n')

        # render DHCP configuration
        tmpl = jinja2.Template(dhcp_cfg)
        dhcp_text = tmpl.render(dhcp)
        with open(self._dhcp_cfg_file, 'w') as f:
            f.write(dhcp_text)

        cmd  = 'start-stop-daemon --start --quiet --pidfile ' + \
            self._dhcp_pid_file
        cmd += ' --exec /sbin/dhclient --'
        # now pass arguments to dhclient binary
        cmd += ' -4 -nw -cf {} -pf {} -lf {} {}'.format(
            self._dhcp_cfg_file, self._dhcp_pid_file, self._dhcp_lease_file, self.config['ifname'])
        return self._cmd(cmd)


    def _del_dhcp(self):
        """
        De-configure interface as DHCP clinet. All auto generated files like
        pid, config and lease will be removed.

        Example:

        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.del_dhcp()
        """
        pid = 0
        if os.path.isfile(self._dhcp_pid_file):
            with open(self._dhcp_pid_file, 'r') as f:
                pid = int(f.read())
        else:
            self._debug_msg('No DHCP client PID found')
            return None

        # stop dhclient, we need to call dhclient and tell it should release the
        # aquired IP address. tcpdump tells me:
        # 172.16.35.103.68 > 172.16.35.254.67: [bad udp cksum 0xa0cb -> 0xb943!] BOOTP/DHCP, Request from 00:50:56:9d:11:df, length 300, xid 0x620e6946, Flags [none] (0x0000)
        #  Client-IP 172.16.35.103
        #  Client-Ethernet-Address 00:50:56:9d:11:df
        #  Vendor-rfc1048 Extensions
        #    Magic Cookie 0x63825363
        #    DHCP-Message Option 53, length 1: Release
        #    Server-ID Option 54, length 4: 172.16.35.254
        #    Hostname Option 12, length 10: "vyos"
        #
        cmd = '/sbin/dhclient -cf {} -pf {} -lf {} -r {}'.format(
                self._dhcp_cfg_file, self._dhcp_pid_file, self._dhcp_lease_file, self.config['ifname'])
        self._cmd(cmd)

        # cleanup old config file
        if os.path.isfile(self._dhcp_cfg_file):
            os.remove(self._dhcp_cfg_file)

        # cleanup old pid file
        if os.path.isfile(self._dhcp_pid_file):
            os.remove(self._dhcp_pid_file)

        # cleanup old lease file
        if os.path.isfile(self._dhcp_lease_file):
            os.remove(self._dhcp_lease_file)


    def _set_dhcpv6(self):
        """
        Configure interface as DHCPv6 client. The dhclient binary is automatically
        started in background!

        Example:

        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.set_dhcpv6()
        """
        dhcpv6 = self.get_dhcpv6_options()

        # better save then sorry .. should be checked in interface script
        # but if you missed it we are safe!
        if dhcpv6['dhcpv6_prm_only'] and dhcpv6['dhcpv6_temporary']:
            raise Exception('DHCPv6 temporary and parameters-only options are mutually exclusive!')

        # render DHCP configuration
        tmpl = jinja2.Template(dhcpv6_cfg)
        dhcpv6_text = tmpl.render(dhcpv6)
        with open(self._dhcpv6_cfg_file, 'w') as f:
            f.write(dhcpv6_text)

        # https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1447715
        #
        # wee need to wait for IPv6 DAD to finish once and interface is added
        # this suxx :-(
        sleep(5)

        # no longer accept router announcements on this interface
        self._write_sysfs('/proc/sys/net/ipv6/conf/{}/accept_ra'
              .format(self.config['ifname']), 0)

        # assemble command-line to start DHCPv6 client (dhclient)
        cmd  = 'start-stop-daemon --start --quiet --pidfile ' + \
            self._dhcpv6_pid_file
        cmd += ' --exec /sbin/dhclient --'
        # now pass arguments to dhclient binary
        cmd += ' -6 -nw -cf {} -pf {} -lf {}'.format(
            self._dhcpv6_cfg_file, self._dhcpv6_pid_file, self._dhcpv6_lease_file)

        # add optional arguments
        if dhcpv6['dhcpv6_prm_only']:
            cmd += ' -S'
        if dhcpv6['dhcpv6_temporary']:
            cmd += ' -T'

        cmd += ' {}'.format(self.config['ifname'])
        return self._cmd(cmd)


    def _del_dhcpv6(self):
        """
        De-configure interface as DHCPv6 clinet. All auto generated files like
        pid, config and lease will be removed.

        Example:

        >>> from vyos.ifconfig import Interface
        >>> j = Interface('eth0')
        >>> j.del_dhcpv6()
        """
        pid = 0
        if os.path.isfile(self._dhcpv6_pid_file):
            with open(self._dhcpv6_pid_file, 'r') as f:
                pid = int(f.read())
        else:
            self._debug_msg('No DHCPv6 client PID found')
            return None

        # stop dhclient
        cmd = 'start-stop-daemon --stop --quiet --pidfile {}'.format(self._dhcpv6_pid_file)
        self._cmd(cmd)

        # accept router announcements on this interface
        self._write_sysfs('/proc/sys/net/ipv6/conf/{}/accept_ra'
              .format(self.config['ifname']), 1)

        # cleanup old config file
        if os.path.isfile(self._dhcpv6_cfg_file):
            os.remove(self._dhcpv6_cfg_file)

        # cleanup old pid file
        if os.path.isfile(self._dhcpv6_pid_file):
            os.remove(self._dhcpv6_pid_file)

        # cleanup old lease file
        if os.path.isfile(self._dhcpv6_lease_file):
            os.remove(self._dhcpv6_lease_file)

    def op_show_interface_stats(self):
        stats = self.get_interface_stats()
        rx = [['bytes','packets','errors','dropped','overrun','mcast'],[stats['rx_bytes'],stats['rx_packets'],stats['rx_errors'],stats['rx_dropped'],stats['rx_over_errors'],stats['multicast']]]
        tx = [['bytes','packets','errors','dropped','carrier','collisions'],[stats['tx_bytes'],stats['tx_packets'],stats['tx_errors'],stats['tx_dropped'],stats['tx_carrier_errors'],stats['collisions']]]
        output = "RX: \n"
        output += tabulate(rx,headers="firstrow",numalign="right",tablefmt="plain")
        output += "\n\nTX: \n"
        output += tabulate(tx,headers="firstrow",numalign="right",tablefmt="plain")
        print('  '.join(('\n'+output.lstrip()).splitlines(True)))

    def get_interface_stats(self):
        interface_stats = dict()
        devices = [f for f in glob.glob("/sys/class/net/**/statistics")]
        for dev_path in devices:
            metrics = [f for f in glob.glob(dev_path +"/**")]
            dev = re.findall(r"/sys/class/net/(.*)/statistics",dev_path)[0]
            dev_dict = dict()
            for metric_path in metrics:
                metric = metric_path.replace(dev_path+"/","")
                if isfile(metric_path):
                    data = open(metric_path, 'r').read()[:-1]
                    dev_dict[metric] = int(data)
            interface_stats[dev] = dev_dict

        return interface_stats[self.config['ifname']]

class LoopbackIf(Interface):
    """
    The loopback device is a special, virtual network interface that your router
    uses to communicate with itself.
    """

    default = {
        'type': 'loopback',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def remove(self):
        """
        Loopback interface can not be deleted from operating system. We can
        only remove all assigned IP addresses.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> i = LoopbackIf('lo').remove()
        """
        # remove all assigned IP addresses from interface
        for addr in self.get_addr():
            if addr in ["127.0.0.1/8", "::1/128"]:
                # Do not allow deletion of the default loopback addresses as
                # this will cause weird system behavior like snmp/ssh no longer
                # operating as expected, see https://phabricator.vyos.net/T2034.
                continue

            self.del_addr(addr)

class DummyIf(Interface):
    """
    A dummy interface is entirely virtual like, for example, the loopback
    interface. The purpose of a dummy interface is to provide a device to route
    packets through without actually transmitting them.
    """

    default = {
        'type': 'dummy',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)


class STPIf(Interface):
    """
    A spanning-tree capable interface. This applies only to bridge port member
    interfaces!
    """

    default = {
        'type': 'stp',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def set_path_cost(self, cost):
        """
        Set interface path cost, only relevant for STP enabled interfaces

        Example:

        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_path_cost(4)
        """
        if not os.path.isfile('/sys/class/net/{}/brport/path_cost'
                              .format(self.config['ifname'])):
            raise TypeError('{} is not a bridge port member'.format(self.config['ifname']))

        return self._write_sysfs('/sys/class/net/{}/brport/path_cost'
                                 .format(self.config['ifname']), cost)

    def set_path_priority(self, priority):
        """
        Set interface path priority, only relevant for STP enabled interfaces

        Example:

        >>> from vyos.ifconfig import Interface
        >>> Interface('eth0').set_path_priority(4)
        """
        if not os.path.isfile('/sys/class/net/{}/brport/priority'
                              .format(self.config['ifname'])):
            raise TypeError('{} is not a bridge port member'.format(self.config['ifname']))

        return self._write_sysfs('/sys/class/net/{}/brport/priority'
                                 .format(self.config['ifname']), priority)


class BridgeIf(Interface):
    """
    A bridge is a way to connect two Ethernet segments together in a protocol
    independent way. Packets are forwarded based on Ethernet address, rather
    than IP address (like a router). Since forwarding is done at Layer 2, all
    protocols can go transparently through a bridge.

    The Linux bridge code implements a subset of the ANSI/IEEE 802.1d standard.
    """

    default = {
        'type': 'bridge',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def set_ageing_time(self, time):
        """
        Set bridge interface MAC address aging time in seconds. Internal kernel
        representation is in centiseconds. Kernel default is 300 seconds.

        Example:
        >>> from vyos.ifconfig import BridgeIf
        >>> BridgeIf('br0').ageing_time(2)
        """
        time = int(time) * 100
        return self._write_sysfs('/sys/class/net/{}/bridge/ageing_time'
                                 .format(self.config['ifname']), time)

    def set_forward_delay(self, time):
        """
        Set bridge forwarding delay in seconds. Internal Kernel representation
        is in centiseconds.

        Example:
        >>> from vyos.ifconfig import BridgeIf
        >>> BridgeIf('br0').forward_delay(15)
        """
        return self._write_sysfs('/sys/class/net/{}/bridge/forward_delay'
                                 .format(self.config['ifname']), (int(time) * 100))

    def set_hello_time(self, time):
        """
        Set bridge hello time in seconds. Internal Kernel representation
        is in centiseconds.

        Example:
        >>> from vyos.ifconfig import BridgeIf
        >>> BridgeIf('br0').set_hello_time(2)
        """
        return self._write_sysfs('/sys/class/net/{}/bridge/hello_time'
                                 .format(self.config['ifname']), (int(time) * 100))

    def set_max_age(self, time):
        """
        Set bridge max message age in seconds. Internal Kernel representation
        is in centiseconds.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> BridgeIf('br0').set_max_age(30)
        """
        return self._write_sysfs('/sys/class/net/{}/bridge/max_age'
                                 .format(self.config['ifname']), (int(time) * 100))

    def set_priority(self, priority):
        """
        Set bridge max aging time in seconds.

        Example:
        >>> from vyos.ifconfig import BridgeIf
        >>> BridgeIf('br0').set_priority(8192)
        """
        return self._write_sysfs('/sys/class/net/{}/bridge/priority'
                                 .format(self.config['ifname']), priority)

    def set_stp(self, state):
        """
        Set bridge STP (Spanning Tree) state. 0 -> STP disabled, 1 -> STP enabled

        Example:
        >>> from vyos.ifconfig import BridgeIf
        >>> BridgeIf('br0').set_stp(1)
        """

        if int(state) >= 0 and int(state) <= 1:
            return self._write_sysfs('/sys/class/net/{}/bridge/stp_state'
                                     .format(self.config['ifname']), state)
        else:
            raise ValueError("Value out of range")


    def set_multicast_querier(self, enable):
        """
        Sets whether the bridge actively runs a multicast querier or not. When a
        bridge receives a 'multicast host membership' query from another network
        host, that host is tracked based on the time that the query was received
        plus the multicast query interval time.

        Use enable=1 to enable or enable=0 to disable

        Example:
        >>> from vyos.ifconfig import Interface
        >>> BridgeIf('br0').set_multicast_querier(1)
        """
        if int(enable) >= 0 and int(enable) <= 1:
            return self._write_sysfs('/sys/class/net/{}/bridge/multicast_querier'
                                     .format(self.config['ifname']), enable)
        else:
            raise ValueError("Value out of range")


    def add_port(self, interface):
        """
        Add physical interface to bridge (member port)

        Example:
        >>> from vyos.ifconfig import Interface
        >>> BridgeIf('br0').add_port('eth0')
        >>> BridgeIf('br0').add_port('eth1')
        """
        cmd = 'ip link set dev {} master {}'.format(interface, self.config['ifname'])
        return self._cmd(cmd)

    def del_port(self, interface):
        """
        Remove member port from bridge instance.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> BridgeIf('br0').del_port('eth1')
        """
        cmd = 'ip link set dev {} nomaster'.format(interface)
        return self._cmd(cmd)

class VLANIf(Interface):
    """
    This class handels the creation and removal of a VLAN interface. It serves
    as base class for BondIf and EthernetIf.
    """

    default = {
        'type': 'vlan',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def remove(self):
        """
        Remove interface from operating system. Removing the interface
        deconfigures all assigned IP addresses and clear possible DHCP(v6)
        client processes.

        Example:
        >>> from vyos.ifconfig import Interface
        >>> i = Interface('eth0')
        >>> i.remove()
        """
        # Do we have sub interfaces (VLANs)? We apply a regex matching
        # subinterfaces (indicated by a .) of a parent interface.
        #
        # As interfaces need to be deleted "in order" starting from Q-in-Q
        # we delete them first.
        vlan_ifs = [f for f in os.listdir(r'/sys/class/net') \
                        if re.match(self.config['ifname'] + r'(?:\.\d+)(?:\.\d+)', f)]

        for vlan in vlan_ifs:
            Interface(vlan).remove()

        # After deleting all Q-in-Q interfaces delete other VLAN interfaces
        # which probably acted as parent to Q-in-Q or have been regular 802.1q
        # interface.
        vlan_ifs = [f for f in os.listdir(r'/sys/class/net') \
                        if re.match(self.config['ifname'] + r'(?:\.\d+)', f)]

        for vlan in vlan_ifs:
            Interface(vlan).remove()

        # All subinterfaces are now removed, continue on the physical interface
        super().remove()


    def add_vlan(self, vlan_id, ethertype='', ingress_qos='', egress_qos=''):
        """
        A virtual LAN (VLAN) is any broadcast domain that is partitioned and
        isolated in a computer network at the data link layer (OSI layer 2).
        Use this function to create a new VLAN interface on a given physical
        interface.

        This function creates both 802.1q and 802.1ad (Q-in-Q) interfaces. Proto
        parameter is used to indicate VLAN type.

        A new object of type VLANIf is returned once the interface has been
        created.

        @param ethertype: If specified, create 802.1ad or 802.1q Q-in-Q VLAN
                          interface
        @param ingress_qos: Defines a mapping of VLAN header prio field to the
                            Linux internal packet priority on incoming frames.
        @param ingress_qos: Defines a mapping of Linux internal packet priority
                            to VLAN header prio field but for outgoing frames.

        Example:
        >>> from vyos.ifconfig import VLANIf
        >>> i = VLANIf('eth0')
        >>> i.add_vlan(10)
        """
        vlan_ifname = self.config['ifname'] + '.' + str(vlan_id)
        if not os.path.exists('/sys/class/net/{}'.format(vlan_ifname)):
            self._vlan_id = int(vlan_id)

            if ethertype:
                self._ethertype = ethertype
                ethertype = 'proto {}'.format(ethertype)

            # Optional ingress QOS mapping
            opt_i = ''
            if ingress_qos:
                opt_i = 'ingress-qos-map ' + ingress_qos
            # Optional egress QOS mapping
            opt_e = ''
            if egress_qos:
                opt_e = 'egress-qos-map ' + egress_qos

            # create interface in the system
            cmd = 'ip link add link {intf} name {intf}.{vlan} type vlan {proto} id {vlan} {opt_e} {opt_i}' \
                   .format(intf=self.config['ifname'], vlan=self._vlan_id, proto=ethertype, opt_e=opt_e, opt_i=opt_i)
            self._cmd(cmd)

        # return new object mapping to the newly created interface
        # we can now work on this object for e.g. IP address setting
        # or interface description and so on
        return VLANIf(vlan_ifname)


    def del_vlan(self, vlan_id):
        """
        Remove VLAN interface from operating system. Removing the interface
        deconfigures all assigned IP addresses and clear possible DHCP(v6)
        client processes.

        Example:
        >>> from vyos.ifconfig import VLANIf
        >>> i = VLANIf('eth0.10')
        >>> i.del_vlan()
        """
        vlan_ifname = self.config['ifname'] + '.' + str(vlan_id)
        VLANIf(vlan_ifname).remove()


class EthernetIf(VLANIf):
    """
    Abstraction of a Linux Ethernet Interface
    """

    default = {
        'type': 'ethernet',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def _delete (self):
        # Ethernet interfaces can not be removed
        pass

    def get_driver_name(self):
        """
        Return the driver name used by NIC. Some NICs don't support all
        features e.g. changing link-speed, duplex

        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.get_driver_name()
        'vmxnet3'
        """
        sysfs_file = '/sys/class/net/{}/device/driver/module'.format(self.config['ifname'])
        if os.path.exists(sysfs_file):
            link = os.readlink(sysfs_file)
            return os.path.basename(link)
        else:
            return None

    def set_flow_control(self, enable):
        """
        Changes the pause parameters of the specified Ethernet device.

        @param enable: true -> enable pause frames, false -> disable pause frames

        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_flow_control(True)
        """
        if enable not in ['on', 'off']:
            raise ValueError("Value out of range")

        if self.get_driver_name() in ['vmxnet3', 'virtio_net']:
            self._debug_msg('{} driver does not support changing flow control settings!'
                            .format(self.get_driver_name()))
            return

        # Get current flow control settings:
        cmd = '/sbin/ethtool --show-pause {0}'.format(self.config['ifname'])
        tmp = self._cmd(cmd)

        # The above command returns - with tabs:
        #
        # Pause parameters for eth0:
        # Autonegotiate:  on
        # RX:             off
        # TX:             off
        if re.search("Autonegotiate:\ton", tmp):
            if enable == "on":
                # flowcontrol is already enabled - no need to re-enable it again
                # this will prevent the interface from flapping as applying the
                # flow-control settings will take the interface down and bring
                # it back up every time.
                return

        # Assemble command executed on system. Unfortunately there is no way
        # to change this setting via sysfs
        cmd = '/sbin/ethtool --pause {0} autoneg {1} tx {1} rx {1}'.format(
              self.config['ifname'], enable)
        try:
            # An exception will be thrown if the settings are not changed
            return self._cmd(cmd)
        except CalledProcessError:
            pass


    def set_speed_duplex(self, speed, duplex):
        """
        Set link speed in Mbit/s and duplex.

        @speed can be any link speed in MBit/s, e.g. 10, 100, 1000 auto
        @duplex can be half, full, auto

        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_speed_duplex('auto', 'auto')
        """

        if speed not in ['auto', '10', '100', '1000', '2500', '5000', '10000', '25000', '40000', '50000', '100000', '400000']:
            raise ValueError("Value out of range (speed)")

        if duplex not in ['auto', 'full', 'half']:
            raise ValueError("Value out of range (duplex)")

        if self.get_driver_name() in ['vmxnet3', 'virtio_net']:
            self._debug_msg('{} driver does not support changing speed/duplex settings!'
                            .format(self.get_driver_name()))
            return

        # Get current speed and duplex settings:
        cmd = '/sbin/ethtool {0}'.format(self.config['ifname'])
        tmp = self._cmd(cmd)

        if re.search("\tAuto-negotiation: on", tmp):
            if speed == 'auto' and duplex == 'auto':
                # bail out early as nothing is to change
                return
        else:
            # read in current speed and duplex settings
            cur_speed = 0
            cur_duplex = ''
            for line in tmp.splitlines():
                if line.lstrip().startswith("Speed:"):
                    non_decimal = re.compile(r'[^\d.]+')
                    cur_speed = non_decimal.sub('', line)
                    continue

                if line.lstrip().startswith("Duplex:"):
                    cur_duplex = line.split()[-1].lower()
                    break

            if (cur_speed == speed) and (cur_duplex == duplex):
                # bail out early as nothing is to change
                return

        cmd = '/sbin/ethtool -s {}'.format(self.config['ifname'])
        if speed == 'auto' or duplex == 'auto':
            cmd += ' autoneg on'
        else:
            cmd += ' speed {} duplex {} autoneg off'.format(speed, duplex)

        return self._cmd(cmd)


    def set_gro(self, state):
        """
        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_gro('on')
        """
        if state not in ['on', 'off']:
            raise ValueError('state must be "on" or "off"')

        cmd = '/sbin/ethtool -K {} gro {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)


    def set_gso(self, state):
        """
        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_gso('on')
        """
        if state not in ['on', 'off']:
            raise ValueError('state must be "on" or "off"')

        cmd = '/sbin/ethtool -K {} gso {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)


    def set_sg(self, state):
        """
        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_sg('on')
        """
        if state not in ['on', 'off']:
            raise ValueError('state must be "on" or "off"')

        cmd = '/sbin/ethtool -K {} sg {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)


    def set_tso(self, state):
        """
        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_tso('on')
        """
        if state not in ['on', 'off']:
            raise ValueError('state must be "on" or "off"')

        cmd = '/sbin/ethtool -K {} tso {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)


    def set_ufo(self, state):
        """
        Example:
        >>> from vyos.ifconfig import EthernetIf
        >>> i = EthernetIf('eth0')
        >>> i.set_udp_offload('on')
        """
        if state not in ['on', 'off']:
            raise ValueError('state must be "on" or "off"')

        cmd = '/sbin/ethtool -K {} ufo {}'.format(self.config['ifname'], state)
        return self._cmd(cmd)

class MACVLANIf(VLANIf):
    """
    Abstraction of a Linux MACvlan interface
    """

    options = VLANIf.options + ['link', 'mode']
    default = {
        'type': 'macvlan',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def _create(self):
        cmd = 'ip link add {intf} link {link} type macvlan mode {mode}'.format(**self.config)
        self._cmd(cmd)

    @staticmethod
    def get_config():
        """
        VXLAN interfaces require a configuration when they are added using
        iproute2. This static method will provide the configuration dictionary
        used by this class.

        Example:
        >> dict = MACVLANIf().get_config()
        """
        config = {
            'address': '',
            'link': 0,
            'mode': ''
        }
        return config

    def set_mode(self, mode):
        """
        """

        cmd = 'ip link set dev {} type macvlan mode {}'.format(self.config['ifname'], mode)
        return self._cmd(cmd)


class BondIf(VLANIf):
    """
    The Linux bonding driver provides a method for aggregating multiple network
    interfaces into a single logical "bonded" interface. The behavior of the
    bonded interfaces depends upon the mode; generally speaking, modes provide
    either hot standby or load balancing services. Additionally, link integrity
    monitoring may be performed.
    """

    default = {
        'type': 'bond',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def remove(self):
        """
        Remove interface from operating system. Removing the interface
        deconfigures all assigned IP addresses and clear possible DHCP(v6)
        client processes.
        Example:
        >>> from vyos.ifconfig import Interface
        >>> i = Interface('eth0')
        >>> i.remove()
        """
        # when a bond member gets deleted, all members are placed in A/D state
        # even when they are enabled inside CLI. This will make the config
        # and system look async.
        slave_list = []
        for s in self.get_slaves():
            slave = {
                'ifname' : s,
                'state': Interface(s).get_state()
            }
            slave_list.append(slave)

        # remove bond master which places members in disabled state
        super().remove()

        # replicate previous interface state before bond destruction back to
        # physical interface
        for slave in slave_list:
             i = Interface(slave['ifname'])
             i.set_state(slave['state'])


    def set_hash_policy(self, mode):
        """
        Selects the transmit hash policy to use for slave selection in
        balance-xor, 802.3ad, and tlb modes. Possible values are: layer2,
        layer2+3, layer3+4, encap2+3, encap3+4.

        The default value is layer2

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').set_hash_policy('layer2+3')
        """
        if not mode in ['layer2', 'layer2+3', 'layer3+4', 'encap2+3', 'encap3+4']:
            raise ValueError("Value out of range")
        return self._write_sysfs('/sys/class/net/{}/bonding/xmit_hash_policy'
                                 .format(self.config['ifname']), mode)

    def set_arp_interval(self, interval):
        """
        Specifies the ARP link monitoring frequency in milliseconds.

        The ARP monitor works by periodically checking the slave devices
        to determine whether they have sent or received traffic recently
        (the precise criteria depends upon the bonding mode, and the
        state of the slave). Regular traffic is generated via ARP probes
        issued for the addresses specified by the arp_ip_target option.

        If ARP monitoring is used in an etherchannel compatible mode
        (modes 0 and 2), the switch should be configured in a mode that
        evenly distributes packets across all links. If the switch is
        configured to distribute the packets in an XOR fashion, all
        replies from the ARP targets will be received on the same link
        which could cause the other team members to fail.

        value of 0 disables ARP monitoring. The default value is 0.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').set_arp_interval('100')
        """
        if int(interval) == 0:
            """
            Specifies the MII link monitoring frequency in milliseconds.
            This determines how often the link state of each slave is
            inspected for link failures. A value of zero disables MII
            link monitoring. A value of 100 is a good starting point.
            """
            return self._write_sysfs('/sys/class/net/{}/bonding/miimon'
                                     .format(self.config['ifname']), interval)
        else:
            return self._write_sysfs('/sys/class/net/{}/bonding/arp_interval'
                                     .format(self.config['ifname']), interval)

    def get_arp_ip_target(self):
        """
        Specifies the IP addresses to use as ARP monitoring peers when
        arp_interval is > 0. These are the targets of the ARP request sent to
        determine the health of the link to the targets. Specify these values
        in ddd.ddd.ddd.ddd format. Multiple IP addresses must be separated by
        a comma. At least one IP address must be given for ARP monitoring to
        function. The maximum number of targets that can be specified is 16.

        The default value is no IP addresses.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').get_arp_ip_target()
        '192.0.2.1'
        """
        return self._read_sysfs('/sys/class/net/{}/bonding/arp_ip_target'
                                .format(self.config['ifname']))

    def set_arp_ip_target(self, target):
        """
        Specifies the IP addresses to use as ARP monitoring peers when
        arp_interval is > 0. These are the targets of the ARP request sent to
        determine the health of the link to the targets. Specify these values
        in ddd.ddd.ddd.ddd format. Multiple IP addresses must be separated by
        a comma. At least one IP address must be given for ARP monitoring to
        function. The maximum number of targets that can be specified is 16.

        The default value is no IP addresses.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').set_arp_ip_target('192.0.2.1')
        >>> BondIf('bond0').get_arp_ip_target()
        '192.0.2.1'
        """
        return self._write_sysfs('/sys/class/net/{}/bonding/arp_ip_target'
                                 .format(self.config['ifname']), target)

    def add_port(self, interface):
        """
        Enslave physical interface to bond.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').add_port('eth0')
        >>> BondIf('bond0').add_port('eth1')
        """
        # An interface can only be added to a bond if it is in 'down' state. If
        # interface is in 'up' state, the following Kernel error will  be thrown:
        # bond0: eth1 is up - this may be due to an out of date ifenslave.
        Interface(interface).set_state('down')

        return self._write_sysfs('/sys/class/net/{}/bonding/slaves'
                                 .format(self.config['ifname']), '+' + interface)

    def del_port(self, interface):
        """
        Remove physical port from bond

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').del_port('eth1')
        """
        return self._write_sysfs('/sys/class/net/{}/bonding/slaves'
                                 .format(self.config['ifname']), '-' + interface)

    def get_slaves(self):
        """
        Return a list with all configured slave interfaces on this bond.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').get_slaves()
        ['eth1', 'eth2']
        """
        enslaved_ifs = []
        # retrieve real enslaved interfaces from OS kernel
        sysfs_bond = '/sys/class/net/{}'.format(self.config['ifname'])
        if os.path.isdir(sysfs_bond):
            for directory in os.listdir(sysfs_bond):
                if 'lower_' in directory:
                    enslaved_ifs.append(directory.replace('lower_',''))

        return enslaved_ifs


    def set_primary(self, interface):
        """
        A string (eth0, eth2, etc) specifying which slave is the primary
        device. The specified device will always be the active slave while it
        is available. Only when the primary is off-line will alternate devices
        be used. This is useful when one slave is preferred over another, e.g.,
        when one slave has higher throughput than another.

        The primary option is only valid for active-backup, balance-tlb and
        balance-alb mode.

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').set_primary('eth2')
        """
        if not interface:
            # reset primary interface
            interface = '\0'

        return self._write_sysfs('/sys/class/net/{}/bonding/primary'
                                 .format(self.config['ifname']), interface)

    def set_mode(self, mode):
        """
        Specifies one of the bonding policies. The default is balance-rr
        (round robin).

        Possible values are: balance-rr, active-backup, balance-xor,
        broadcast, 802.3ad, balance-tlb, balance-alb

        NOTE: the bonding mode can not be changed when the bond itself has
        slaves

        Example:
        >>> from vyos.ifconfig import BondIf
        >>> BondIf('bond0').set_mode('802.3ad')
        """
        if not mode in [
            'balance-rr', 'active-backup', 'balance-xor', 'broadcast',
                        '802.3ad', 'balance-tlb', 'balance-alb']:
            raise ValueError("Value out of range")

        return self._write_sysfs('/sys/class/net/{}/bonding/mode'
                                 .format(self.config['ifname']), mode)

class WireGuardIf(Interface):
    options = ['port', 'private-key', 'pubkey', 'psk', 'allowed-ips', 'fwmark', 'endpoint', 'keepalive']

    default = {
        'type': 'wireguard',
        'port': 0,
        'private-key': None,
        'pubkey': None,
        'psk': '/dev/null',
        'allowed-ips': [],
        'fwmark': 0x00,
        'endpoint': None,
        'keepalive': 0
    }

    """
    Wireguard interface class, contains a comnfig dictionary since
    wireguard VPN is being comnfigured via the wg command rather than
    writing the config into a file. Otherwise if a pre-shared key is used
    (symetric enryption key), it would we exposed within multiple files.
    Currently it's only within the config.boot if the config was saved.

    Example:
    >>> from vyos.ifconfig import WireGuardIf as wg_if
    >>> wg_intfc = wg_if("wg01")
    >>> print (wg_intfc.wg_config)
    {'private-key': None, 'keepalive': 0, 'endpoint': None, 'port': 0,
    'allowed-ips': [], 'pubkey': None, 'fwmark': 0, 'psk': '/dev/null'}
    >>> wg_intfc.wg_config['keepalive'] = 100
    >>> print (wg_intfc.wg_config)
    {'private-key': None, 'keepalive': 100, 'endpoint': None, 'port': 0,
    'allowed-ips': [], 'pubkey': None, 'fwmark': 0, 'psk': '/dev/null'}
    """

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def update(self):
        if not self.config['private-key']:
            raise ValueError("private key required")
        else:
            # fmask permission check?
            pass

        cmd = "wg set {} ".format(self.config['ifname'])
        cmd += "listen-port {} ".format(self.config['port'])
        cmd += "fwmark {} ".format(str(self.config['fwmark']))
        cmd += "private-key {} ".format(self.config['private-key'])
        cmd += "peer {} ".format(self.config['pubkey'])
        cmd += " preshared-key {} ".format(self.config['psk'])
        cmd += " allowed-ips "
        for aip in self.config['allowed-ips']:
            if aip != self.config['allowed-ips'][-1]:
                cmd += aip + ","
            else:
                cmd += aip
        if self.config['endpoint']:
            cmd += " endpoint {}".format(self.config['endpoint'])
        cmd += " persistent-keepalive {}".format(self.config['keepalive'])

        self._cmd(cmd)

        # remove psk since it isn't required anymore and is saved in the cli
        # config only !!
        if self.config['psk'] != '/dev/null':
            if os.path.exists(self.config['psk']):
                os.remove(self.config['psk'])


    def remove_peer(self, peerkey):
        """
        Remove a peer of an interface, peers are identified by their public key.
        Giving it a readable name is a vyos feature, to remove a peer the pubkey
        and the interface is needed, to remove the entry.
        """
        cmd = "wg set {0} peer {1} remove".format(
            self.config['ifname'], str(peerkey))
        return self._cmd(cmd)

    def op_show_interface(self):
        wgdump = vyos.interfaces.wireguard_dump().get(self.config['ifname'],None)

        c = Config()
        c.set_level(["interfaces","wireguard",self.config['ifname']])
        description = c.return_effective_value(["description"])
        ips = c.return_effective_values(["address"])

        print ("interface: {}".format(self.config['ifname']))
        if (description):
            print ("  description: {}".format(description))

        if (ips):
            print ("  address: {}".format(", ".join(ips)))
        print ("  public key: {}".format(wgdump['public_key']))
        print ("  private key: (hidden)")
        print ("  listening port: {}".format(wgdump['listen_port']))
        print ()

        for peer in c.list_effective_nodes(["peer"]):
            if wgdump['peers']:
                pubkey = c.return_effective_value(["peer",peer,"pubkey"])
                if pubkey in wgdump['peers']:
                    wgpeer = wgdump['peers'][pubkey]

                    print ("  peer: {}".format(peer))
                    print ("    public key: {}".format(pubkey))

                    """ figure out if the tunnel is recently active or not """
                    status = "inactive"
                    if (wgpeer['latest_handshake'] is None):
                        """ no handshake ever """
                        status = "inactive"
                    else:
                        if int(wgpeer['latest_handshake']) > 0:
                            delta = timedelta(seconds=int(time.time() - wgpeer['latest_handshake']))
                            print ("    latest handshake: {}".format(delta))
                            if (time.time() - int(wgpeer['latest_handshake']) < (60*5)):
                                """ Five minutes and the tunnel is still active """
                                status = "active"
                            else:
                                """ it's been longer than 5 minutes """
                                status = "inactive"
                        elif int(wgpeer['latest_handshake']) == 0:
                            """ no handshake ever """
                            status = "inactive"
                        print ("    status: {}".format(status))

                    if wgpeer['endpoint'] is not None:
                        print ("    endpoint: {}".format(wgpeer['endpoint']))

                    if wgpeer['allowed_ips'] is not None:
                        print ("    allowed ips: {}".format(",".join(wgpeer['allowed_ips']).replace(",",", ")))

                    if wgpeer['transfer_rx'] > 0 or wgpeer['transfer_tx'] > 0:
                        rx_size =size(wgpeer['transfer_rx'],system=alternative)
                        tx_size =size(wgpeer['transfer_tx'],system=alternative)
                        print ("    transfer: {} received, {} sent".format(rx_size,tx_size))

                    if wgpeer['persistent_keepalive'] is not None:
                        print ("    persistent keepalive: every {} seconds".format(wgpeer['persistent_keepalive']))
                print()
        super().op_show_interface_stats()


class VXLANIf(Interface):
    """
    The VXLAN protocol is a tunnelling protocol designed to solve the
    problem of limited VLAN IDs (4096) in IEEE 802.1q. With VXLAN the
    size of the identifier is expanded to 24 bits (16777216).

    VXLAN is described by IETF RFC 7348, and has been implemented by a
    number of vendors.  The protocol runs over UDP using a single
    destination port.  This document describes the Linux kernel tunnel
    device, there is also a separate implementation of VXLAN for
    Openvswitch.

    Unlike most tunnels, a VXLAN is a 1 to N network, not just point to
    point. A VXLAN device can learn the IP address of the other endpoint
    either dynamically in a manner similar to a learning bridge, or make
    use of statically-configured forwarding entries.

    For more information please refer to:
    https://www.kernel.org/doc/Documentation/networking/vxlan.txt
    """

    default = {
        'type': 'vxlan',
        'vni': 0,
        'dev': '',
        'group': '',
        'remote': '',
        'port': 8472,   # The Linux implementation of VXLAN pre-dates
                        # the IANA's selection of a standard destination port
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def _create(self):
        # we assume that by default a multicast interface is created
        group = 'group {}'.format(self.config['group'])

        # if remote host is specified we ignore the multicast address
        if config['remote']:
            group = 'remote {}'.format(self.config['remote'])

        # an underlay device is not always specified
        dev = ''
        if self.config['dev']:
            dev = 'dev {}'.format(self.config['dev'])

        cmd = 'ip link add {intf} type vxlan id {vni} {grp_rem} {dev} dstport {port}' \
            .format(intf=self.config['ifname'], vni=self.config['vni'], grp_rem=group, dev=dev, port=self.config['port'])
        self._cmd(cmd)

    @staticmethod
    def get_config():
        """
        VXLAN interfaces require a configuration when they are added using
        iproute2. This static method will provide the configuration dictionary
        used by this class.

        Example:
        >> dict = VXLANIf().get_config()
        """
        config = {
            'vni': 0,
            'dev': '',
            'group': '',
            'port': 8472, # The Linux implementation of VXLAN pre-dates
                          # the IANA's selection of a standard destination port
            'remote': ''
        }
        return config

class GeneveIf(Interface):
    """
    Geneve: Generic Network Virtualization Encapsulation

    For more information please refer to:
    https://tools.ietf.org/html/draft-gross-geneve-00
    https://www.redhat.com/en/blog/what-geneve
    https://developers.redhat.com/blog/2019/05/17/an-introduction-to-linux-virtual-interfaces-tunnels/#geneve
    https://lwn.net/Articles/644938/
    """

    default = {
        'type': 'geneve',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def _create (self):
        cmd = 'ip link add name {} type geneve id {} remote {}' \
                .format(self.config['ifname'], config['vni'], config['remote'])
        self._cmd(cmd)

        # interface is always A/D down. It needs to be enabled explicitly
        self.set_state('down')

    @staticmethod
    def get_config():
        """
        GENEVE interfaces require a configuration when they are added using
        iproute2. This static method will provide the configuration dictionary
        used by this class.

        Example:
        >> dict = GeneveIf().get_config()
        """
        config = {
            'vni': 0,
            'remote': ''
        }
        return config

class L2TPv3If(Interface):
    """
    The Linux bonding driver provides a method for aggregating multiple network
    interfaces into a single logical "bonded" interface. The behavior of the
    bonded interfaces depends upon the mode; generally speaking, modes provide
    either hot standby or load balancing services. Additionally, link integrity
    monitoring may be performed.
    """

    options = Interface.options + \
        ['tunnel_id','peer_tunnel_id','local_port','remote_port','encapsulation','local_address','remote_address']
    default = {
        'type': 'l2tp',
    }

    def __init__(self, ifname, **kargs):
        super().__init__(ifname, **kargs)

    def _create (self):
        # create tunnel interface
        cmd = 'ip l2tp add tunnel tunnel_id {} '.format(config['tunnel_id'])
        cmd += 'peer_tunnel_id {} '.format(config['peer_tunnel_id'])
        cmd += 'udp_sport {} '.format(config['local_port'])
        cmd += 'udp_dport {} '.format(config['remote_port'])
        cmd += 'encap {} '.format(config['encapsulation'])
        cmd += 'local {} '.format(config['local_address'])
        cmd += 'remote {} '.format(config['remote_address'])
        self._cmd(cmd)

        # setup session
        cmd = 'ip l2tp add session name {} '.format(self.config['ifname'])
        cmd += 'tunnel_id {} '.format(config['tunnel_id'])
        cmd += 'session_id {} '.format(config['session_id'])
        cmd += 'peer_session_id  {} '.format(config['peer_session_id'])
        self._cmd(cmd)

        # interface is always A/D down. It needs to be enabled explicitly
        self.set_state('down')

    def remove(self):
        """
        Remove interface from operating system. Removing the interface
        deconfigures all assigned IP addresses.
        Example:
        >>> from vyos.ifconfig import L2TPv3If
        >>> i = L2TPv3If('l2tpeth0')
        >>> i.remove()
        """

        if os.path.exists('/sys/class/net/{}'.format(self.config['ifname'])):
            # interface is always A/D down. It needs to be enabled explicitly
            self.set_state('down')

            if self._config['tunnel_id'] and self._config['session_id']:
                cmd = 'ip l2tp del session tunnel_id {} '.format(self._config['tunnel_id'])
                cmd += 'session_id {} '.format(self._config['session_id'])
                self._cmd(cmd)

            if self._config['tunnel_id']:
                cmd = 'ip l2tp del tunnel tunnel_id {} '.format(self._config['tunnel_id'])
                self._cmd(cmd)

    @staticmethod
    def get_config():
        """
        L2TPv3 interfaces require a configuration when they are added using
        iproute2. This static method will provide the configuration dictionary
        used by this class.

        Example:
        >> dict = L2TPv3If().get_config()
        """
        config = {
            'peer_tunnel_id': '',
            'local_port': 0,
            'remote_port': 0,
            'encapsulation': 'udp',
            'local_address': '',
            'remote_address': '',
            'session_id': '',
            'tunnel_id': '',
            'peer_session_id': ''
        }
        return config