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.db import transaction

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, Network, IPPoolTable

from synnefo.logic import networks

from ipaddr import IPv4Address, IPAddress, IPNetwork

log = getLogger(__name__)

def subnet_command(action):

    def decorator(func):

        @wraps(func)

        @transaction.commit_on_success()

        def wrapper(subnet, *args, **kwargs):

            return func(subnet, *args, **kwargs)

        return wrapper

    return decorator

def list_subnets(user_id):

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

    log.debug('list_subnets')

    user_subnets = Subnet.objects.filter(network__userid=user_id)

    return user_subnets

@transaction.commit_on_success

def create_subnet(network_id, cidr, name, ipversion, gateway, dhcp, slac,

                  dns_nameservers, allocation_pools, host_routes, user_id):

    """

    Create a subnet

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

    """

    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")

    if ipversion not in [4, 6]:

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

    check_number_of_subnets(network, ipversion)

    # Returns the first available IP in the subnet

    try:

        cidr_ip = IPNetwork(cidr)

    except ValueError:

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

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

    if gateway is "":

        gateway = potential_gateway

    if ipversion == 6:

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

        if slac is not None:

            dhcp = check_boolean_value(slac, "enable_slac")

        else:

            dhcp = check_boolean_value(dhcp, "dhcp")

    else:

        networks.validate_network_params(cidr, gateway)

        dhcp = check_boolean_value(dhcp, "dhcp")

    name = check_name_length(name)

    gateway_ip = IPAddress(gateway)

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

                                ipversion=ipversion, gateway=gateway,

                                dhcp=dhcp, host_routes=host_routes,

                                dns_nameservers=dns_nameservers)

    if allocation_pools is not None:

        # If the user specified IP allocation pools, validate them and use them

        if ipversion == 6:

            raise api.faults.Conflict("Can't allocate an IP Pool in IPv6")

        validate_subpools(allocation_pools, cidr_ip, gateway_ip)

    if allocation_pools is None and ipversion == 4:

        # Check if the gateway is the first IP of the subnet, in this case

        # create a single ip pool

        if int(gateway_ip) - int(cidr_ip) == 1:

            allocation_pools = [[gateway_ip + 1, cidr_ip.broadcast - 1]]

        else:

            # If the gateway isn't the first available ip, create two different

            # ip pools adjacent to said ip

            allocation_pools.append([cidr_ip.network + 1, gateway_ip - 1])

            allocation_pools.append([gateway_ip + 1, cidr_ip.broadcast - 1])

    if allocation_pools:

        create_ip_pools(allocation_pools, cidr_ip, sub)

    return sub

def get_subnet(sub_id):

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

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

    try:

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

    except Subnet.DoesNotExist:

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

    return subnet

def delete_subnet():

    """

    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")

@transaction.commit_on_success

def update_subnet(sub_id, name):

    """

    Update the fields of a subnet

    Only the name can be updated

    """

    log.info('Update subnet %s, name %s' % (sub_id, name))

    try:

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

    except:

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

    check_name_length(name)

    subnet.name = name

    subnet.save()

    return subnet

#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 = 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_slac'] = 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: IPAddress(ip_str), pool))

                 for pool in pools]

    pool_list.sort()

    return pool_list

def create_ip_pools(pools, cidr, subnet):

    """Create IP Pools in the database"""

    for pool in pools:

        size = int(pool[1]) - int(pool[0]) + 1

        base = str(cidr)

        offset = int(pool[0]) - int(cidr.network)

        ip_pool = IPPoolTable.objects.create(size=size, offset=offset,

                                             base=base, subnet=subnet)

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_number_of_subnets(network, version):

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

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

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

                                    "network is allowed")

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

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')

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 validate_subpools(pool_list, cidr, gateway):

    """

    Validate the given IP pools are inside the cidr range

    Validate there are no overlaps in the given pools

    Finally, validate the gateway isn't in the given ip pools

    Input must be a list containing a sublist with start/end ranges as

    ipaddr.IPAddress items eg.,

    [[IPv4Address('192.168.42.11'), IPv4Address('192.168.42.15')],

     [IPv4Address('192.168.42.30'), IPv4Address('192.168.42.60')]]

    """

    if pool_list[0][0] <= cidr.network:

        raise api.faults.Conflict("IP Pool out of bounds")

    elif pool_list[-1][1] >= cidr.broadcast:

        raise api.faults.Conflict("IP Pool out of bounds")

    for start, end in pool_list:

        if start > end:

            raise api.faults.Conflict("Invalid IP pool range")

        # Raise BadRequest if gateway is inside the pool range

        if not (gateway < start or gateway > end):

            raise api.faults.Conflict("Gateway cannot be in pool range")

    # Check if there is a conflict between the IP Poll ranges

    end = cidr.network

    for pool in pool_list:

        if end >= pool[0]:

            raise api.faults.Conflict("IP Pool range conflict")

        end = pool[1]