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 snf_django.lib.api import utils

from synnefo.db.models import Subnet

from synnefo.logic import subnets

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"""

    subnet_list = subnets.list_subnets(request.user_uniq)

    subnets_dict = [subnet_to_dict(sub)

                    for sub in subnet_list.order_by('id')]

    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")

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

    if allocation_pools is not None:

        pool = parse_ip_pools(allocation_pools)

        allocation_pools = string_to_ipaddr(pool)

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

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

    # 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', "")

    try:

        cidr_ip = ipaddr.IPNetwork(cidr)

    except ValueError:

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

    potential_gateway = str(ipaddr.IPNetwork(cidr).network + 1)

    if gateway is "":

        gateway = potential_gateway

    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=200)

@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)

    if subnet.network.userid != user_id:

        raise api.failts.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 = subnet.ip_pools.all()

    pools = list()

    if allocation_pools:

        for pool in allocation_pools:

            cidr = ipaddr.IPNetwork(pool.base)

            start = str(cidr.network + pool.offset)

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

            pools.append({"start": start, "end": end})

    dictionary = dict({'id': str(subnet.id),

                       'network_id': str(subnet.network.id),

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

                       'tenant_id': subnet.network.userid,

                       'user_id': subnet.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': pools if pools is not None else []})

    if subnet.ipversion == 6:

        dictionary['enable_slaac'] = subnet.dhcp

    return dictionary

def string_to_ipaddr(pools):

    """Convert [["192.168.42.1", "192.168.42.15"],

                ["192.168.42.30", "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')]]

    and sort the output

    """

    pool_list = [(map(lambda ip_str: ipaddr.IPAddress(ip_str), pool))

                 for pool in pools]

    pool_list.sort()

    return pool_list

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_name_length(name):

    """Check if the length of a name is within acceptable value"""

    if len(str(name)) > Subnet.SUBNET_NAME_LENGTH:

        raise api.faults.BadRequest("Subnet name too long")

    return name

def get_subnet_fromdb(subnet_id, user_id, for_update=False):

    """Return a Subnet instance or raise ItemNotFound.

    This is the same as util.get_network

    """

    try:

        subnet_id = int(subnet_id)

        if for_update:

            return Subnet.objects.select_for_update().get(id=subnet_id,

                                                          network__userid=

                                                          user_id)

        return Subnet.objects.get(id=subnet_id, network__userid=user_id)

    except (ValueError, Subnet.DoesNotExist):

        raise api.faults.ItemNotFound('Subnet not found')

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

            [["192.168.42.1", "192.168.42.15"],

             ["192.168.42.30", "192.168.42.60"]]

    """

    pool_list = list()

    for pool in pools:

        parse = [pool["start"], pool["end"]]

        pool_list.append(parse)

    return pool_list

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