Synnefo

# Copyright 2013 GRNET S.A. All rights reserved.

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from logging import getLogger

from snf_django.lib import api

from django.conf.urls import patterns

from django.http import HttpResponse

from django.utils import simplejson as json

from django.db.models import Q

from snf_django.lib.api import utils

from synnefo.db.models import Subnet

from synnefo.logic import subnets

from synnefo.api import util

import ipaddr

log = getLogger(__name__)

urlpatterns = patterns(

    'synnefo.api.subnets',

    (r'^(?:/|.json|.xml)?$', 'demux'),

    (r'^/([-\w]+)(?:/|.json|.xml)?$', 'subnet_demux'))

def demux(request):

    if request.method == 'GET':

        return list_subnets(request)

    elif request.method == 'POST':

        return create_subnet(request)

    else:

        return api.api_method_not_allowed(request)

def subnet_demux(request, sub_id):

    if request.method == 'GET':

        return get_subnet(request, sub_id)

    elif request.method == 'DELETE':

        return delete_subnet(request, sub_id)

    elif request.method == 'PUT':

        return update_subnet(request, sub_id)

    else:

        return api.api_method_not_allowed(request)

@api.api_method(http_method='GET', user_required=True, logger=log)

def list_subnets(request):

    """List all subnets of a user"""

    userid = request.user_uniq

    subnets_list = Subnet.objects.filter(Q(network__public=True) |

                                         (Q(network__userid=userid) &

                                          Q(network__public=False)))\

                                 .order_by("id")

    subnets_list = subnets_list.prefetch_related("ip_pools")\

                               .select_related("network")

    subnets_list = api.utils.filter_modified_since(request,

                                                   objects=subnets_list)

    subnets_dict = [subnet_to_dict(sub) for sub in subnets_list]

    data = json.dumps({'subnets': subnets_dict})

    return HttpResponse(data, status=200)

@api.api_method(http_method='POST', user_required=True, logger=log)

def create_subnet(request):

    """Create a subnet

    network_id and the desired cidr are mandatory, everything else is optional

    """

    dictionary = utils.get_request_dict(request)

    log.info('create subnet %s', dictionary)

    try:

        subnet = dictionary['subnet']

        network_id = subnet['network_id']

        cidr = subnet['cidr']

    except KeyError:

        raise api.faults.BadRequest("Malformed request")

    name = subnet.get('name', None)

    ipversion = subnet.get('ip_version', 4)

    allocation_pools = subnet.get('allocation_pools', None)

    if allocation_pools is not None:

        allocation_pools = parse_ip_pools(allocation_pools)

    try:

        cidr_ip = ipaddr.IPNetwork(cidr)

    except ValueError:

        raise api.faults.BadRequest("Malformed CIDR '%s'" % cidr)

    # If no gateway is specified, send an empty string, because None is used

    # if the user wants no gateway at all

    gateway = subnet.get('gateway_ip', "")

    if gateway is "":

        gateway = str(cidr_ip.network + 1)

    dhcp = subnet.get('enable_dhcp', True)

    slaac = subnet.get('enable_slaac', None)

    if ipversion == 6:

        if slaac is not None:

            dhcp = check_boolean_value(slaac, "enable_slaac")

        else:

            dhcp = check_boolean_value(dhcp, "dhcp")

    else:

        dhcp = check_boolean_value(dhcp, "dhcp")

    dns = subnet.get('dns_nameservers', None)

    hosts = subnet.get('host_routes', None)

    sub = subnets.create_subnet(network_id=network_id,

                                cidr=cidr,

                                name=name,

                                ipversion=ipversion,

                                gateway=gateway,

                                dhcp=dhcp,

                                slaac=slaac,

                                dns_nameservers=dns,

                                allocation_pools=allocation_pools,

                                host_routes=hosts,

                                user_id=request.user_uniq)

    subnet_dict = subnet_to_dict(sub)

    data = json.dumps({'subnet': subnet_dict})

    return HttpResponse(data, status=201)

@api.api_method(http_method='GET', user_required=True, logger=log)

def get_subnet(request, sub_id):

    """Show info of a specific subnet"""

    user_id = request.user_uniq

    subnet = subnets.get_subnet(sub_id, prefetch_related=True)

    if (subnet.network.userid != user_id) and (subnet.network.public is False):

        raise api.faults.Unauthorized("You're not allowed to view this subnet")

    subnet_dict = subnet_to_dict(subnet)

    data = json.dumps({'subnet': subnet_dict})

    return HttpResponse(data, status=200)

@api.api_method(http_method='DELETE', user_required=True, logger=log)

def delete_subnet(request, sub_id):

    """Delete a subnet, raises BadRequest

    A subnet is deleted ONLY when the network that it belongs to is deleted

    """

    raise api.faults.BadRequest("Deletion of a subnet is not supported")

@api.api_method(http_method='PUT', user_required=True, logger=log)

def update_subnet(request, sub_id):

    """Update the fields of a subnet

    Only the name can be updated, everything else returns BadRequest

    """

    dictionary = utils.get_request_dict(request)

    user_id = request.user_uniq

    try:

        subnet = dictionary['subnet']

    except KeyError:

        raise api.faults.BadRequest("Malformed request")

    if len(subnet) != 1 or "name" not in subnet:

        raise api.faults.BadRequest("Only the name of subnet can be updated")

    name = subnet.get("name", None)

    subnet_dict = subnet_to_dict(subnets.update_subnet(sub_id, name, user_id))

    data = json.dumps({'subnet': subnet_dict})

    return HttpResponse(data, status=200)

#Utility functions

def subnet_to_dict(subnet):

    """Returns a dictionary containing the info of a subnet"""

    dns = check_empty_lists(subnet.dns_nameservers)

    hosts = check_empty_lists(subnet.host_routes)

    allocation_pools = [render_ip_pool(pool)

                        for pool in subnet.ip_pools.all()]

    network = subnet.network

    d = {'id': str(subnet.id),

         'network_id': str(subnet.network_id),

         'name': subnet.name if subnet.name is not None else "",

         'tenant_id': network.userid,

         'user_id': network.userid,

         'gateway_ip': subnet.gateway,

         'ip_version': subnet.ipversion,

         'cidr': subnet.cidr,

         'enable_dhcp': subnet.dhcp,

         'dns_nameservers': dns,

         'host_routes': hosts,

         'allocation_pools': allocation_pools}

    if subnet.ipversion == 6:

        d['enable_slaac'] = subnet.dhcp

    d['links'] = util.subnet_to_links(subnet.id)

    return d

def render_ip_pool(pool):

    network = ipaddr.IPNetwork(pool.base).network

    start = str(network + pool.offset)

    end = str(network + pool.offset + pool.size - 1)

    return {"start": start, "end": end}

def parse_ip_pools(pools):

    """Convert [{'start': '192.168.42.1', 'end': '192.168.42.15'},

             {'start': '192.168.42.30', 'end': '192.168.42.60'}]

    to

            [(IPv4Address("192.168.42.1"), IPv4Address("192.168.42.15")),

             (IPv4Address("192.168.42.30"), IPv4Address("192.168.42.60"))]

    """

    try:

        return sorted([(ipaddr.IPv4Address(p["start"]),

                        ipaddr.IPv4Address(p["end"])) for p in pools])

    except KeyError:

        raise api.faults.BadRequest("Malformed allocation pool.")

    except ipaddr.AddressValueError:

        raise api.faults.BadRequest("Allocation pools contain invalid IPv4"

                                    " address")

def check_empty_lists(value):

    """Check if value is Null/None, in which case we return an empty list"""

    if value is None:

        return []

    return value

def check_boolean_value(value, key):

    """Check if dhcp value is in acceptable values"""

    if value not in [True, False]:

        raise api.faults.BadRequest("Malformed request, %s must "

                                    "be True or False" % key)

    return value