re2o/topologie/models.py

# -*- mode: python; coding: utf-8 -*-
# Re2o est un logiciel d'administration développé initiallement au rezometz. Il
# se veut agnostique au réseau considéré, de manière à être installable en
# quelques clics.
#
# Copyright © 2017  Gabriel Détraz
# Copyright © 2017  Lara Kermarec
# Copyright © 2017  Augustin Lemesle
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""
Definition of models for the 'topologie' app.

The following models are defined:
    * stack (grouping switches): id, id_min, id_max and name
    * switch: name, number of ports, related interface and machine (MAC
    address, IP address etc.) (see machines.models.interface)
    * port: related to a switch by foreign_key, number of the port, related
    exclusively to another port, machine (server or AP) or room outlets
    * room: list of outlets, name and comments about the plug's state
"""

from __future__ import unicode_literals

import itertools

from django.db import models
from django.db.models.signals import post_save, post_delete
from django.utils.functional import cached_property
from django.core.cache import cache
from django.dispatch import receiver
from django.core.exceptions import ValidationError
from django.db import IntegrityError
from django.db import transaction
from django.utils.translation import ugettext_lazy as _
from reversion import revisions as reversion

from preferences.models import OptionalTopologie, RadiusKey, SwitchManagementCred
from machines.models import Machine, regen, Role, MachineType, Ipv6List
from re2o.mixins import AclMixin, RevMixin


class Stack(AclMixin, RevMixin, models.Model):
    """Switch stack.

    Attributes:
        name: the name of the stack.
        stack_id: the ID of the stack, as a text chosen by the user.
        details: the description to provide details about the stack.
        member_id_min: the minimum switch ID in the stack.
        member_id_max: the maximum switch ID in the stack.
    """

    name = models.CharField(max_length=32, blank=True, null=True)
    stack_id = models.CharField(max_length=32, unique=True)
    details = models.CharField(max_length=255, blank=True, null=True)
    member_id_min = models.PositiveIntegerField()
    member_id_max = models.PositiveIntegerField()

    class Meta:
        permissions = (("view_stack", _("Can view a stack object")),)
        verbose_name = _("switches stack")
        verbose_name_plural = _("switches stacks")

    def __str__(self):
        return " ".join([self.name, self.stack_id])

    def save(self, *args, **kwargs):
        self.clean()
        if not self.name:
            self.name = self.stack_id
        super(Stack, self).save(*args, **kwargs)

    def clean(self):
        """Check if id_max < id_min."""
        if self.member_id_max < self.member_id_min:
            raise ValidationError(
                {"member_id_max": _("The maximum ID is less than the minimum ID.")}
            )


class AccessPoint(Machine):
    """Wireless Access Point. Inherits from machines.interfaces.

    Attributes:
        location: the text to provide details about the AP's location.
    """

    location = models.CharField(
        max_length=255,
        help_text=_("Details about the AP's location."),
        blank=True,
        null=True,
    )

    class Meta:
        permissions = (("view_accesspoint", _("Can view an access point object")),)
        verbose_name = _("access point")
        verbose_name_plural = _("access points")

    def port(self):
        """Return the queryset of ports for this device."""
        return Port.objects.filter(machine_interface__machine=self)

    def switch(self):
        """Return the switch where this is plugged."""
        return Switch.objects.filter(ports__machine_interface__machine=self)

    def building(self):
        """Return the building of the AP/Server (building of the switches
        connected to...).
        """
        return Building.objects.filter(switchbay__switch=self.switch())

    @cached_property
    def short_name(self):
        return str(self.interface_set.first().domain.name)

    @classmethod
    def all_ap_in(cls, building_instance):
        """Get all the APs of the given building.

        Args:
            building_instance: the building used to find APs.

        Returns:
            The queryset of all APs in the given building.
        """
        return cls.objects.filter(
            interface__port__switch__switchbay__building=building_instance
        )

    def __str__(self):
        return str(self.interface_set.first())

    # We want to retrieve the default behaviour given by AclMixin rather
    # than the one overwritten by Machine. If you are not familiar with
    # the behaviour of `super`, please check https://docs.python.org/3/library/functions.html#super

    @classmethod
    def get_instance(cls, *args, **kwargs):
        return super(Machine, cls).get_instance(*args, **kwargs)

    @classmethod
    def can_create(cls, *args, **kwargs):
        return super(Machine, cls).can_create(*args, **kwargs)

    def can_edit(self, *args, **kwargs):
        return super(Machine, self).can_edit(*args, **kwargs)

    def can_delete(self, *args, **kwargs):
        return super(Machine, self).can_delete(*args, **kwargs)

    def can_view(self, *args, **kwargs):
        return super(Machine, self).can_view(*args, **kwargs)


class Server(Machine):
    """Dummy class, to retrieve servers of a building, or get switch of a
    server.
    """

    class Meta:
        proxy = True

    def port(self):
        """Return the queryset of ports for this device."""
        return Port.objects.filter(machine_interface__machine=self)

    def switch(self):
        """Return the switch where this is plugged."""
        return Switch.objects.filter(ports__machine_interface__machine=self)

    def building(self):
        """Return the building of the AP/Server (building of the switches
        connected to...).
        """
        return Building.objects.filter(switchbay__switch=self.switch())

    @cached_property
    def short_name(self):
        return str(self.interface_set.first().domain.name)

    @classmethod
    def all_server_in(cls, building_instance):
        """Get all the servers of the given building.

        Args:
            building_instance: the building used to find servers.

        Returns:
            The queryset of all servers in the given building.
        """
        return cls.objects.filter(
            interface__port__switch__switchbay__building=building_instance
        ).exclude(accesspoint__isnull=False)

    def __str__(self):
        return str(self.interface_set.first())

    # We want to retrieve the default behaviour given by AclMixin rather
    # than the one overwritten by Machine. If you are not familiar with
    # the behaviour of `super`, please check https://docs.python.org/3/library/functions.html#super

    @classmethod
    def get_instance(cls, *args, **kwargs):
        return super(Machine, cls).get_instance(*args, **kwargs)

    @classmethod
    def can_create(cls, *args, **kwargs):
        return super(Machine, cls).can_create(*args, **kwargs)

    def can_edit(self, *args, **kwargs):
        return super(Machine, self).can_edit(*args, **kwargs)

    def can_delete(self, *args, **kwargs):
        return super(Machine, self).can_delete(*args, **kwargs)

    def can_view(self, *args, **kwargs):
        return super(Machine, self).can_view(*args, **kwargs)


class Switch(Machine):
    """Switch.

    Attributes:
        number: the number of ports of the switch.
        stack: the stack the switch is a part of.
        stack_member_id: the ID of the switch in the related stack.
        model: the model of the switch.
        switchbay: the bay in which the switch is located.
        radius_key: the RADIUS key of the switch.
        management_creds: the management credentials of the switch.
        automatic_provision: whether automatic provision is enabled for the
            switch.
    """

    number = models.PositiveIntegerField(help_text=_("Number of ports."))
    stack = models.ForeignKey(
        "topologie.Stack", blank=True, null=True, on_delete=models.SET_NULL
    )
    stack_member_id = models.PositiveIntegerField(blank=True, null=True)
    model = models.ForeignKey(
        "topologie.ModelSwitch",
        blank=True,
        null=True,
        on_delete=models.SET_NULL,
        help_text=_("Switch model."),
    )
    switchbay = models.ForeignKey(
        "topologie.SwitchBay", blank=True, null=True, on_delete=models.SET_NULL
    )
    radius_key = models.ForeignKey(
        "preferences.RadiusKey",
        blank=True,
        null=True,
        on_delete=models.PROTECT,
        help_text=_("RADIUS key of the switch."),
    )
    management_creds = models.ForeignKey(
        "preferences.SwitchManagementCred",
        blank=True,
        null=True,
        on_delete=models.PROTECT,
        help_text=_("Management credentials for the switch."),
    )
    automatic_provision = models.BooleanField(
        default=False, help_text=_("Automatic provision for the switch.")
    )

    class Meta:
        unique_together = ("stack", "stack_member_id")
        permissions = (("view_switch", _("Can view a switch object")),)
        verbose_name = _("switch")
        verbose_name_plural = _("switches")

    def clean(self):
        """Check if the stack member ID is in the range of the stack's IDs and
        calls the clean of the parent class.
        """
        super(Switch, self).clean()
        if self.stack is not None:
            if self.stack_member_id is not None:
                if (self.stack_member_id > self.stack.member_id_max) or (
                    self.stack_member_id < self.stack.member_id_min
                ):
                    raise ValidationError(
                        {
                            "stack_member_id": _(
                                "The switch ID exceeds the"
                                " limits allowed by the stack."
                            )
                        }
                    )
            else:
                raise ValidationError(
                    {"stack_member_id": _("The stack member ID can't be void.")}
                )

    def create_ports(self, begin, end):
        """Create ports for the switch if the values are consistent.

        Args:
            begin: the number of the start port.
            end: the number of the end port.
        """
        if end < begin:
            raise ValidationError(_("The end port is less than the start port."))
        ports_to_create = range(begin, end + 1)
        existing_ports = Port.objects.filter(switch=self.switch).values_list(
            "port", flat=True
        )
        non_existing_ports = list(set(ports_to_create) - set(existing_ports))

        if len(non_existing_ports) + existing_ports.count() > self.number:
            raise ValidationError(_("This switch can't have that many ports."))
        with transaction.atomic(), reversion.create_revision():
            reversion.set_comment("Creation")
            Port.objects.bulk_create(
                [
                    Port(switch=self.switch, port=port_id)
                    for port_id in non_existing_ports
                ]
            )

    def main_interface(self):
        """Get the main interface of the switch (the management interface)."""
        switch_iptype = OptionalTopologie.get_cached_value("switchs_ip_type")
        if switch_iptype:
            return (
                self.interface_set.filter(machine_type__ip_type=switch_iptype).first()
                or self.interface_set.first()
            )
        return self.interface_set.first()

    @cached_property
    def get_name(self):
        return self.name or getattr(self.main_interface(), "domain", "Unknown")

    @cached_property
    def get_radius_key(self):
        """Get the RADIUS key object related to the switch."""
        return self.radius_key or RadiusKey.objects.filter(default_switch=True).first()

    @cached_property
    def get_radius_key_value(self):
        """Get the RADIUS key as a string, or None if there are no RADIUS key
        related to the switch.
        """
        if self.get_radius_key:
            return self.get_radius_key.radius_key
        else:
            return None

    @cached_property
    def get_radius_servers_objects(self):
        """Return radius servers objects for Switchs provisioning, via REST API.
        
        Returns :
            Interfaces objects query_set for the Role type radius-server
        """
        return Role.all_interfaces_for_roletype("radius-server").filter(
            machine_type__in=MachineType.objects.filter(
                interface__in=self.interface_set.all()
            )
        )

    @cached_property
    def get_radius_servers(self):
        """Return radius servers string, ipv4 and ipv6 for Switchs provisioning,
        via REST API.
        
        Returns :
            Ip dict of interfaces for the Role type radius-server
        """
        def return_ips_dict(interfaces):
            return {
                "ipv4": [str(interface.ipv4) for interface in interfaces],
                "ipv6": Ipv6List.objects.filter(interface__in=interfaces).filter(active=True).values_list(
                    "ipv6", flat=True
                ),
            }

        return return_ips_dict(self.get_radius_servers_objects)

    @cached_property
    def get_management_cred(self):
        """Get the management credentials objects of the switch."""
        return (
            self.management_creds
            or SwitchManagementCred.objects.filter(default_switch=True).first()
        )

    @cached_property
    def get_management_cred_value(self):
        """Get the management credentials as a dictionary, or None if there are
        no management credentials related to the switch.
        """
        if self.get_management_cred:
            return {
                "id": self.get_management_cred.management_id,
                "pass": self.get_management_cred.management_pass,
            }
        else:
            return None

    @cached_property
    def rest_enabled(self):
        return (
            OptionalTopologie.get_cached_value("switchs_rest_management")
            or self.automatic_provision
        )

    @cached_property
    def web_management_enabled(self):
        sw_management = OptionalTopologie.get_cached_value("switchs_web_management")
        sw_management_ssl = OptionalTopologie.get_cached_value(
            "switchs_web_management_ssl"
        )
        if sw_management_ssl:
            return "ssl"
        elif sw_management:
            return "plain"
        else:
            return self.automatic_provision

    @cached_property
    def ipv4(self):
        """Get the IPv4 address of the switch's management interface."""
        return str(self.main_interface().ipv4)

    @cached_property
    def ipv6(self):
        """Get the IPv6 address of the switch's management interface."""
        return str(self.main_interface().ipv6().first())

    @cached_property
    def interfaces_subnet(self):
        """Get a dictionary of IPv4 addresses:subnets of all the switch's
        interfaces.
        """
        return dict(
            (
                str(interface.ipv4),
                interface.machine_type.ip_type.ip_net_full_info
                or interface.machine_type.ip_type.ip_set_full_info[0],
            )
            for interface in self.interface_set.all()
        )

    @cached_property
    def interfaces6_subnet(self):
        """Get a dictionary of IPv6 addresses:subnets of all the switch's
        interfaces.
        """
        return dict(
            (
                str(interface.ipv6().first()),
                interface.machine_type.ip_type.ip6_set_full_info,
            )
            for interface in self.interface_set.all()
        )

    @cached_property
    def list_modules(self):
        """Get the list of dictionaries (rank, reference) of modules related to
        the switch.
        """
        modules = []
        if getattr(self.model, "is_modular", None):
            if self.model.is_itself_module:
                modules.append((1, self.model.reference))
            for module_of_self in self.moduleonswitch_set.all():
                modules.append((module_of_self.slot, module_of_self.module.reference))
        return modules

    @cached_property
    def get_dormitory(self):
        """Get the dormitory in which the switch is located."""
        if self.switchbay:
            return self.switchbay.building.dormitory
        else:
            return None

    @classmethod
    def nothing_profile(cls):
        """Return default nothing port profile."""
        nothing_profile, _created = PortProfile.objects.get_or_create(
            profil_default="nothing", name="nothing", radius_type="NO"
        )
        return nothing_profile

    def profile_type_or_nothing(self, profile_type):
        """Return the profile for a profile_type of this switch.

        If it exists, return the defined default profile for a profile type on
        the dormitory which the switch belongs.
        Otherwise, return the nothing profile.
        """
        profile_queryset = PortProfile.objects.filter(profil_default=profile_type)
        if self.get_dormitory:
            port_profile = (
                profile_queryset.filter(on_dormitory=self.get_dormitory).first()
                or profile_queryset.first()
            )
        else:
            port_profile = profile_queryset.first()
        return port_profile or Switch.nothing_profile()

    @cached_property
    def default_uplink_profile(self):
        """Default uplink profile for that switch -- in cache."""
        return self.profile_type_or_nothing("uplink")

    @cached_property
    def default_access_point_profile(self):
        """Default AP profile for that switch -- in cache."""
        return self.profile_type_or_nothing("access_point")

    @cached_property
    def default_room_profile(self):
        """Default room profile for that switch -- in cache."""
        return self.profile_type_or_nothing("room")

    @cached_property
    def default_asso_machine_profile(self):
        """Default asso machine profile for that switch -- in cache."""
        return self.profile_type_or_nothing("asso_machine")

    def __str__(self):
        return str(self.get_name)

    # We want to retrieve the default behaviour given by AclMixin rather
    # than the one overwritten by Machine. If you are not familiar with
    # the behaviour of `super`, please check https://docs.python.org/3/library/functions.html#super

    @classmethod
    def get_instance(cls, *args, **kwargs):
        return super(Machine, cls).get_instance(*args, **kwargs)

    @classmethod
    def can_create(cls, *args, **kwargs):
        return super(Machine, cls).can_create(*args, **kwargs)

    def can_edit(self, *args, **kwargs):
        return super(Machine, self).can_edit(*args, **kwargs)

    def can_delete(self, *args, **kwargs):
        return super(Machine, self).can_delete(*args, **kwargs)

    def can_view(self, *args, **kwargs):
        return super(Machine, self).can_view(*args, **kwargs)


class ModelSwitch(AclMixin, RevMixin, models.Model):
    """Switch model.

    Attributes:
        reference: the reference of the switch model.
        commercial_name: the commercial name of the switch model.
        constructor: the constructor of the switch model.
        firmware: the firmware of the switch model.
        is_modular: whether the switch model is modular.
        is_itself_module: whether the switch is considered as a module.
    """

    reference = models.CharField(max_length=255)
    commercial_name = models.CharField(max_length=255, null=True, blank=True)
    constructor = models.ForeignKey(
        "topologie.ConstructorSwitch", on_delete=models.PROTECT
    )
    firmware = models.CharField(max_length=255, null=True, blank=True)
    is_modular = models.BooleanField(
        default=False, help_text=_("The switch model is modular.")
    )
    is_itself_module = models.BooleanField(
        default=False, help_text=_("The switch is considered as a module.")
    )

    class Meta:
        permissions = (("view_modelswitch", _("Can view a switch model object")),)
        verbose_name = _("switch model")
        verbose_name_plural = _("switch models")

    def __str__(self):
        if self.commercial_name:
            return str(self.constructor) + " " + str(self.commercial_name)
        else:
            return str(self.constructor) + " " + self.reference


class ModuleSwitch(AclMixin, RevMixin, models.Model):
    """Switch module.

    Attributes:
        reference: the reference of the switch module.
        comment: the comment to describe the switch module.
    """

    reference = models.CharField(
        max_length=255,
        help_text=_("Reference of a module."),
        verbose_name=_("module reference"),
    )
    comment = models.CharField(
        max_length=255,
        null=True,
        blank=True,
        help_text=_("Comment."),
        verbose_name=_("comment"),
    )

    class Meta:
        permissions = (("view_moduleswitch", _("Can view a switch module object")),)
        verbose_name = _("switch module")
        verbose_name_plural = _("switch modules")

    def __str__(self):
        return str(self.reference)


class ModuleOnSwitch(AclMixin, RevMixin, models.Model):
    """Link beetween module and switch.

    Attributes:
        module: the switch module related to the link.
        switch: the switch related to the link.
        slot: the slot on the switch related to the link.
    """

    module = models.ForeignKey("ModuleSwitch", on_delete=models.CASCADE)
    switch = models.ForeignKey("Switch", on_delete=models.CASCADE)
    slot = models.CharField(
        max_length=15, help_text=_("Slot on switch."), verbose_name=_("slot")
    )

    class Meta:
        permissions = (
            (
                "view_moduleonswitch",
                _("Can view a link between switch and module object"),
            ),
        )
        verbose_name = _("link between switch and module")
        verbose_name_plural = _("links between switch and module")
        unique_together = ["slot", "switch"]

    def __str__(self):
        return _("On slot %(slot)s of %(switch)s").format(
            slot=str(self.slot), switch=str(self.switch)
        )


class ConstructorSwitch(AclMixin, RevMixin, models.Model):
    """Switch constructor.

    Attributes:
        name: the name of the switch constructor.
    """

    name = models.CharField(max_length=255)

    class Meta:
        permissions = (
            ("view_constructorswitch", _("Can view a switch constructor object")),
        )
        verbose_name = _("switch constructor")
        verbose_name_plural = _("switch constructors")

    def __str__(self):
        return self.name


class SwitchBay(AclMixin, RevMixin, models.Model):
    """Switch bay.

    Attributes:
        name: the name of the switch bay.
        building: the building in which the switch bay is located.
        info: the information to describe to switch bay.
    """

    name = models.CharField(max_length=255)
    building = models.ForeignKey("Building", on_delete=models.PROTECT)
    info = models.CharField(max_length=255, blank=True, null=True)

    class Meta:
        permissions = (("view_switchbay", _("Can view a switch bay object")),)
        verbose_name = _("switch bay")
        verbose_name_plural = _("switch bays")

    def __str__(self):
        return self.name


class Dormitory(AclMixin, RevMixin, models.Model):
    """Dormitory.

    Attributes:
        name: the name of the dormitory.
    """

    name = models.CharField(max_length=255)

    class Meta:
        permissions = (("view_dormitory", _("Can view a dormitory object")),)
        verbose_name = _("dormitory")
        verbose_name_plural = _("dormitories")

    def all_ap_in(self):
        """Get all the APs in the dormitory."""
        return AccessPoint.all_ap_in(self.building_set.all())

    @classmethod
    def is_multiple_dorms(cls):
        multiple_dorms = cache.get("multiple_dorms")
        if multiple_dorms:
            return multiple_dorms
        else:
            return cache.get_or_set("multiple_dorms", cls.objects.count() > 1)

    def __str__(self):
        return self.name


class Building(AclMixin, RevMixin, models.Model):
    """Building.

    Attributes:
        name: the name of the building.
        dormitory: the dormitory of the building (a Dormitory can contain
            multiple dormitories).
    """

    name = models.CharField(max_length=255)
    dormitory = models.ForeignKey("Dormitory", on_delete=models.PROTECT)

    class Meta:
        permissions = (("view_building", _("Can view a building object")),)
        verbose_name = _("building")
        verbose_name_plural = _("buildings")

    def all_ap_in(self):
        """Get all the APs in the building."""
        return AccessPoint.all_ap_in(self)

    def get_name(self):
        if Dormitory.is_multiple_dorms():
            return self.dormitory.name + " : " + self.name
        else:
            return self.name

    @cached_property
    def cached_name(self):
        return self.get_name()

    def __str__(self):
        return self.cached_name


class Port(AclMixin, RevMixin, models.Model):
    """Port of a switch.

    A port is related exclusively to either:
        * a room
        * a machine, e.g. server
        * another port
    Behaviour according to the RADIUS mode:
        * STRICT: connection only if the machine and room have access
        * COMMON: check only the machine's state
        * NO: accept only request coming from the port and set on the standard
        VLAN.
        * BLOQ: reject all requests.
    The VLAN can be forced to override the general policy for VLAN setting.
    This enables to force a port to a particular VLAN. It adds to the RADIUS
    policy.

    Attributes:
        switch: the switch to which the port belongs.
        port: the port number on the switch for the Port object.
        room: the room to which the port is related.
        machine_interface: the machine to which the port is related
        related: the other port to which is port is related.
        custom_profile: the port profile of the port.
        state: whether the port is active.
        details: the details to describre the port.
    """

    switch = models.ForeignKey("Switch", related_name="ports", on_delete=models.CASCADE)
    port = models.PositiveIntegerField()
    room = models.ForeignKey("Room", on_delete=models.PROTECT, blank=True, null=True)
    machine_interface = models.ForeignKey(
        "machines.Interface", on_delete=models.SET_NULL, blank=True, null=True
    )
    related = models.OneToOneField(
        "self", null=True, blank=True, related_name="related_port"
    )
    custom_profile = models.ForeignKey(
        "PortProfile", on_delete=models.PROTECT, blank=True, null=True
    )
    state = models.BooleanField(
        default=True,
        help_text=_("Port state Active."),
        verbose_name=_("port state Active"),
    )
    details = models.CharField(max_length=255, blank=True)

    class Meta:
        unique_together = ("switch", "port")
        permissions = (("view_port", _("Can view a port object")),)
        verbose_name = _("port")
        verbose_name_plural = _("ports")

    @cached_property
    def pretty_name(self):
        """More elaborated name for label on switch configuration."""
        if self.related:
            return _("Uplink: ") + self.related.switch.short_name
        elif self.machine_interface:
            return _("Machine: ") + str(self.machine_interface.domain)
        elif self.room:
            return _("Room: ") + str(self.room)
        else:
            return _("Unknown")

    @cached_property
    def get_port_profile(self):
        """Get the configuration profile for this port.

        Returns:
            The custom profile if it exists, else the default profile of the
            dormitory if it exists, else the global default profile, else the
            nothing profile.
        """
        if self.custom_profile:
            return self.custom_profile
        elif self.related:
            return self.switch.default_uplink_profile
        elif self.machine_interface:
            if hasattr(self.machine_interface.machine, "accesspoint"):
                return self.switch.default_access_point_profile
            else:
                return self.switch.default_asso_machine_profile
        elif self.room:
            return self.switch.default_room_profile
        else:
            return Switch.nothing_profile()

    @classmethod
    def get_instance(cls, port_id, *_args, **kwargs):
        return (
            cls.objects.select_related("machine_interface__domain__extension")
            .select_related("machine_interface__machine__switch")
            .select_related("room")
            .select_related("related")
            .prefetch_related("switch__interface_set__domain__extension")
            .get(pk=port_id)
        )

    def make_port_related(self):
        """Synchronise the related port with self."""
        related_port = self.related
        related_port.related = self
        related_port.save()

    def clean_port_related(self):
        """Delete the related relation on self."""
        related_port = self.related_port
        related_port.related = None
        related_port.save()

    def clean(self):
        """
        Check if the port is only related exclusively to either a room, a
        machine or another port.
        Check if the related port is not self and applies the relation to the
        related port if the relation is correct.
        Delete the relation if it points to self.
        """
        if hasattr(self, "switch"):
            if self.port > self.switch.number:
                raise ValidationError(
                    _("The port can't exist, its number is too great.")
                )
        if (
            self.room
            and self.machine_interface
            or self.room
            and self.related
            or self.machine_interface
            and self.related
        ):
            raise ValidationError(
                _("Room, interface and related port are mutually exclusive.")
            )
        if self.related == self:
            raise ValidationError(_("A port can't be related to itself."))
        if self.related and not self.related.related:
            if self.related.machine_interface or self.related.room:
                raise ValidationError(
                    _(
                        "The related port is already used, please clear it"
                        " before creating the relation."
                    )
                )
            else:
                self.make_port_related()
        elif hasattr(self, "related_port"):
            self.clean_port_related()

    def __str__(self):
        return str(self.switch) + " - " + str(self.port)


class Room(AclMixin, RevMixin, models.Model):
    """Room.

    Attributes:
        name: the name of the room.
        details: the details describing the room.
        building: the building in which the room is located.
    """

    name = models.CharField(max_length=255)
    details = models.CharField(max_length=255, blank=True)
    building = models.ForeignKey("Building", on_delete=models.PROTECT)

    class Meta:
        ordering = ["building__name"]
        permissions = (("view_room", _("Can view a room object")),)
        verbose_name = _("room")
        verbose_name_plural = _("rooms")
        unique_together = ("name", "building")

    def __str__(self):
        return self.building.cached_name + " " + self.name


class PortProfile(AclMixin, RevMixin, models.Model):
    """Port profile.

    Contains the information of the ports' configuration for a switch.

    Attributes:
        name: the name of the port profile.
        profil_default: the type of default profile (room, AP, uplink etc.).
        on_dormitory: the dormitory with this default port profile.
        vlan_untagged: the VLAN untagged of the port profile.
        vlan_tagged: the VLAN(s) tagged of the port profile.
        radius_type: the type of RADIUS authentication (inactive, MAC-address
            or 802.1X) of the port profile.
        radius_mode: the RADIUS mode of the port profile.
        speed: the port speed limit of the port profile.
        mac_limit: the MAC limit of the port profile.
        flow_control: whether flow control is enabled.
        dhcp_snooping: whether DHCP snooping is enabled.
        dhcpv6_snooping: whether DHCPv6 snooping is enabled.
        arp_protect: whether ARP protection is enabled.
        ra_guard: whether RA guard is enabled.
        loop_protect: whether loop protection is enabled.
    """

    TYPES = (("NO", "NO"), ("802.1X", "802.1X"), ("MAC-radius", _("MAC-RADIUS")))
    MODES = (("STRICT", "STRICT"), ("COMMON", "COMMON"))
    SPEED = (
        ("10-half", "10-half"),
        ("100-half", "100-half"),
        ("10-full", "10-full"),
        ("100-full", "100-full"),
        ("1000-full", "1000-full"),
        ("auto", "auto"),
        ("auto-10", "auto-10"),
        ("auto-100", "auto-100"),
    )
    PROFIL_DEFAULT = (
        ("room", _("Room")),
        ("access_point", _("Access point")),
        ("uplink", _("Uplink")),
        ("asso_machine", _("Organisation machine")),
        ("nothing", _("Nothing")),
    )
    name = models.CharField(max_length=255, verbose_name=_("name"))
    profil_default = models.CharField(
        max_length=32,
        choices=PROFIL_DEFAULT,
        blank=True,
        null=True,
        verbose_name=_("default profile"),
    )
    on_dormitory = models.ForeignKey(
        "topologie.Dormitory",
        related_name="dormitory_ofprofil",
        on_delete=models.SET_NULL,
        blank=True,
        null=True,
        verbose_name=_("profile on dormitory"),
    )
    vlan_untagged = models.ForeignKey(
        "machines.Vlan",
        related_name="vlan_untagged",
        on_delete=models.SET_NULL,
        blank=True,
        null=True,
        verbose_name=_("VLAN untagged"),
    )
    vlan_tagged = models.ManyToManyField(
        "machines.Vlan",
        related_name="vlan_tagged",
        blank=True,
        verbose_name=_("VLAN(s) tagged"),
    )
    radius_type = models.CharField(
        max_length=32,
        choices=TYPES,
        help_text=_("Type of RADIUS authentication: inactive, MAC-address or 802.1X."),
        verbose_name=_("RADIUS type"),
    )
    radius_mode = models.CharField(
        max_length=32,
        choices=MODES,
        default="COMMON",
        help_text=_(
            "In case of MAC-authentication: mode COMMON or STRICT on this port."
        ),
        verbose_name=_("RADIUS mode"),
    )
    speed = models.CharField(
        max_length=32, choices=SPEED, default="auto", help_text=_("Port speed limit.")
    )
    mac_limit = models.IntegerField(
        null=True,
        blank=True,
        help_text=_("Limit of MAC-address on this port."),
        verbose_name=_("MAC limit"),
    )
    flow_control = models.BooleanField(default=False, help_text=_("Flow control."))
    dhcp_snooping = models.BooleanField(
        default=False,
        help_text=_("Protect against rogue DHCP."),
        verbose_name=_("DHCP snooping"),
    )
    dhcpv6_snooping = models.BooleanField(
        default=False,
        help_text=_("Protect against rogue DHCPv6."),
        verbose_name=_("DHCPv6 snooping"),
    )
    arp_protect = models.BooleanField(
        default=False,
        help_text=_("Check if IP address is DHCP assigned."),
        verbose_name=_("ARP protection"),
    )
    ra_guard = models.BooleanField(
        default=False,
        help_text=_("Protect against rogue RA."),
        verbose_name=_("RA guard"),
    )
    loop_protect = models.BooleanField(
        default=False,
        help_text=_("Protect against loop."),
        verbose_name=_("loop protection"),
    )

    class Meta:
        permissions = (("view_portprofile", _("Can view a port profile object")),)
        verbose_name = _("port profile")
        verbose_name_plural = _("port profiles")
        unique_together = ["on_dormitory", "profil_default"]

    security_parameters_fields = [
        "loop_protect",
        "ra_guard",
        "arp_protect",
        "dhcpv6_snooping",
        "dhcp_snooping",
        "flow_control",
    ]

    @cached_property
    def security_parameters_enabled(self):
        return [
            parameter
            for parameter in self.security_parameters_fields
            if getattr(self, parameter)
        ]

    @cached_property
    def security_parameters_as_str(self):
        return ",".join(self.security_parameters_enabled)

    def clean(self):
        """Check that there is only one generic profile default."""
        super(PortProfile, self).clean()
        if (
            self.profil_default
            and not self.on_dormitory
            and PortProfile.objects.exclude(id=self.id)
            .filter(profil_default=self.profil_default)
            .exclude(on_dormitory__isnull=False)
            .exists()
        ):
            raise ValidationError(
                {
                    "profil_default": _(
                        "A default profile for all dormitories of that type already exists."
                    )
                }
            )

    def __str__(self):
        return self.name


@receiver(post_save, sender=AccessPoint)
def ap_post_save(**_kwargs):
    """Regenerate the AP names towards the controller."""
    regen("unifi-ap-names")
    regen("graph_topo")


@receiver(post_delete, sender=AccessPoint)
def ap_post_delete(**_kwargs):
    """Regenerate the AP names towards the controller."""
    regen("unifi-ap-names")
    regen("graph_topo")


@receiver(post_delete, sender=Stack)
def stack_post_delete(**_kwargs):
    """Empty the stack member ID of switches when a stack is deleted."""
    Switch.objects.filter(stack=None).update(stack_member_id=None)


@receiver(post_save, sender=Port)
def port_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Port)
def port_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=ModelSwitch)
def modelswitch_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=ModelSwitch)
def modelswitch_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=Building)
def building_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Building)
def building_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=Switch)
def switch_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Switch)
def switch_post_delete(**_kwargs):
    regen("graph_topo")