Synnefo

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

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from logging import getLogger

from snf_django.lib import api

from snf_django.lib.api import faults

from django.http import HttpResponse

from django.utils import simplejson as json

from snf_django.lib.api import utils

from models import Subnet, Network

from synnefo.logic import networks

from ipaddr import IPv4Network, IPv6Network

log = getLogger(__name__)

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'''

    log.debug('list_subnets')

    user_subnets = Subnet.objects.filter(network__userid=request.user_uniq)

    subnets_dict = [subnet_to_dict(sub)

                    for sub in user_subnets.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'''

    dictionary = utils.get_request_dict(request)

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

    user_id = request.user_uniq

    try:

        subnet = dictionary['subnet']

        network_id = subnet['network_id']

        cidr = subnet['cidr']

    except KeyError:

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

    try:

        network = Network.objects.get(id=network_id)

    except Network.DoesNotExist:

        raise api.faults.ItemNotFound("No networks found with that id")

    if user_id != network.userid:

        raise api.faults.Unauthorized("Unauthorized operation")

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

    if ipversion not in [4, 6]:

        raise api.faults.BadRequest("Malformed IP version type")

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

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

    # Returns the first available IP in the subnet

    if ipversion == 6:

        potential_gateway = str(IPv6Network(cidr).network + 1)

        check_number_of_subnets(network, 6)

    else:

        potential_gateway = str(IPv4Network(cidr).network + 1)

        check_number_of_subnets(network, 4)

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

    if ipversion == 6:

        networks.validate_network_params(None, None, cidr, gateway)

    else:

        networks.validate_network_params(cidr, gateway)

    check_for_hosts_dns(subnet)

    # FIX ME

    try:

        sub = Subnet.objects.create(name=name, network=network, cidr=cidr,

                                    ipversion=ipversion, gateway=gateway,

                                    dhcp=dhcp)

    except:

        return "Error"

    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'''

    log.debug('get_subnet %s', sub_id)

    user_id = request.user_uniq

    try:

        subnet = Subnet.objects.get(id=sub_id)

    except Subnet.DoesNotExist:

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

    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 -- Operation not allowed'''

    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 info of a subnet'''

    dictionary = utils.get_request_dict(request)

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

    user_id = request.user_uniq

    try:

        subnet = dictionary['subnet']

    except KeyError:

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

    original_subnet = get_subnet_fromdb(sub_id, user_id)

    original_dict = subnet_to_dict(original_subnet)

    if subnet.get('ip_version', None):

        raise api.faults.BadRequest("Malformed request, ip_version cannot be "

                                    "updated")

    if subnet.get('cidr', None):

        raise api.faults.BadRequest("Malformed request, cidr cannot be "

                                    "updated")

    if subnet.get('allocation_pools', None):

        raise api.faults.BadRequest("Malformed request, allocation pools "

                                    "cannot be updated")

    check_for_hosts_dns(subnet)

    name = subnet.get('name', original_dict['name'])

    if name:

        check_name_length(name)

    dhcp = subnet.get('enable_dhcp', original_dict['enable_dhcp'])

    check_dhcp_value(dhcp)

    gateway = subnet.get('gateway_ip', original_dict['gateway_ip'])

    #FIX ME, check if IP is in use

    if original_dict['ip_version'] == 6:

        networks.validate_network_params(None, None, original_dict['cidr'],

                                         gateway)

    else:

        networks.validate_network_params(original_dict['cidr'], gateway)

    try:

        original_subnet.gateway = gateway

        original_subnet.name = name

        original_subnet.dhcp = dhcp

        original_subnet.save()

    except:

        #Fix me

        return "Unknown Error"

    subnet_dict = subnet_to_dict(original_subnet)

    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'''

    # FIX ME, allocation pools

    dictionary = dict({'id': subnet.id, 'network_id': subnet.network.id,

                       'name': subnet.name, 'tenant_id': subnet.network.userid,

                       'gateway_ip': subnet.gateway,

                       'ip_version': subnet.ipversion, 'cidr': subnet.cidr,

                       'enable_dhcp': subnet.dhcp, 'dns_nameservers': [],

                       'host_routes': [], 'allocation_pools': []})

    return dictionary

def check_number_of_subnets(network, version):

    '''Check if a user can add a subnet in a network'''

    if network.subnet_set.filter(ipversion=version):

        raise api.faults.BadRequest("Only one subnet of IPv4/IPv6 per "

                                    "network is allowed")

def check_dhcp_value(dhcp):

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

    if dhcp not in [True, False]:

        raise api.faults.BadRequest("Malformed request, enable_dhcp must be "

                                    "True or False")

    return dhcp

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 check_for_hosts_dns(subnet):

    '''

    Check if a request contains host_routes or dns_nameservers options

    Expects the request in a dictionary format

    '''

    if subnet.get('host_routes', None):

        raise api.faults.BadRequest("Setting host routes isn't supported")

    if subnet.get('dns_nameservers', None):

        raise api.faults.BadRequest("Setting dns nameservers isn't supported")

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.')