# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2013 IBM Corp.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.


import contextlib
import functools
import httplib
import os
import shutil
import socket
import time

from oslo.config import cfg

from nova import block_device
from nova.compute import power_state
from nova.openstack.common import excutils
from nova.openstack.common.gettextutils import _
from nova.openstack.common import jsonutils
from nova.openstack.common import log as logging
from nova.virt import driver
from nova.virt.zvm import const
from nova.virt.zvm import exception


LOG = logging.getLogger(__name__)

CONF = cfg.CONF
CONF.import_opt('instances_path', 'nova.compute.manager')


class XCATUrl(object):
    """To return xCAT url for invoking xCAT REST API."""

    def __init__(self):
        """Set constant that used to form xCAT url."""
        self.PREFIX = '/xcatws'
        self.SUFFIX = '?userName=' + CONF.zvm_xcat_username + \
                      '&password=' + CONF.zvm_xcat_password + \
                      '&format=json'

        self.NODES = '/nodes'
        self.VMS = '/vms'
        self.IMAGES = '/images'
        self.OBJECTS = '/objects/osimage'
        self.OS = '/OS'
        self.TABLES = '/tables'
        self.HV = '/hypervisor'
        self.NETWORK = '/networks'

        self.POWER = '/power'
        self.INVENTORY = '/inventory'
        self.STATUS = '/status'
        self.MIGRATE = '/migrate'
        self.CAPTURE = '/capture'
        self.EXPORT = '/export'
        self.IMGIMPORT = '/import'
        self.BOOTSTAT = '/bootstate'
        self.XDSH = '/dsh'

    def _nodes(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.SUFFIX

    def _vms(self, arg=''):
        return self.PREFIX + self.VMS + arg + self.SUFFIX

    def _hv(self, arg=''):
        return self.PREFIX + self.HV + arg + self.SUFFIX

    def rpower(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.POWER + self.SUFFIX

    def nodels(self, arg=''):
        return self._nodes(arg)

    def rinv(self, arg='', addp=None):
        rurl = self.PREFIX + self.NODES + arg + self.INVENTORY + self.SUFFIX
        return self._append_addp(rurl, addp)

    def mkdef(self, arg=''):
        return self._nodes(arg)

    def rmdef(self, arg=''):
        return self._nodes(arg)

    def nodestat(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.STATUS + self.SUFFIX

    def chvm(self, arg=''):
        return self._vms(arg)

    def lsvm(self, arg=''):
        return self._vms(arg)

    def chhv(self, arg=''):
        return self._hv(arg)

    def mkvm(self, arg=''):
        return self._vms(arg)

    def rmvm(self, arg=''):
        return self._vms(arg)

    def tabdump(self, arg='', addp=None):
        rurl = self.PREFIX + self.TABLES + arg + self.SUFFIX
        return self._append_addp(rurl, addp)

    def _append_addp(self, rurl, addp=None):
        if addp is not None:
            return rurl + addp
        else:
            return rurl

    def imgcapture(self, arg=''):
        return self.PREFIX + self.IMAGES + arg + self.CAPTURE + self.SUFFIX

    def imgexport(self, arg=''):
        return self.PREFIX + self.IMAGES + arg + self.EXPORT + self.SUFFIX

    def rmimage(self, arg=''):
        return self.PREFIX + self.IMAGES + arg + self.SUFFIX

    def rmobject(self, arg=''):
        return self.PREFIX + self.OBJECTS + arg + self.SUFFIX

    def lsdef_node(self, arg='', addp=None):
        rurl = self.PREFIX + self.NODES + arg + self.SUFFIX
        return self._append_addp(rurl, addp)

    def lsdef_image(self, arg='', addp=None):
        rurl = self.PREFIX + self.IMAGES + arg + self.SUFFIX
        return self._append_addp(rurl, addp)

    def imgimport(self, arg=''):
        return self.PREFIX + self.IMAGES + self.IMGIMPORT + arg + self.SUFFIX

    def chtab(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.SUFFIX

    def nodeset(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.BOOTSTAT + self.SUFFIX

    def rmigrate(self, arg=''):
        return self.PREFIX + self.NODES + arg + self.MIGRATE + self.SUFFIX

    def gettab(self, arg='', addp=None):
        rurl = self.PREFIX + self.TABLES + arg + self.SUFFIX
        return self._append_addp(rurl, addp)

    def tabch(self, arg='', addp=None):
        """Add/update/delete row(s) in table arg, with attribute addp."""
        rurl = self.PREFIX + self.TABLES + arg + self.SUFFIX
        return self._append_addp(rurl, addp)

    def xdsh(self, arg=''):
        """Run shell command."""
        return self.PREFIX + self.NODES + arg + self.XDSH + self.SUFFIX

    def network(self, arg='', addp=None):
        rurl = self.PREFIX + self.NETWORK + arg + self.SUFFIX
        if addp is not None:
            return rurl + addp
        else:
            return rurl


class XCATConnection():
    """Https requests to xCAT web service."""

    def __init__(self):
        """Initialize https connection to xCAT service."""
        self.host = CONF.zvm_xcat_server
        self.conn = httplib.HTTPSConnection(self.host,
                        timeout=CONF.zvm_xcat_connection_timeout)

    def request(self, method, url, body=None, headers={}):
        """Send https request to xCAT server.

        Will return a python dictionary including:
        {'status': http return code,
         'reason': http reason,
         'message': response message}

        """
        if body is not None:
            body = jsonutils.dumps(body)
            headers = {'content-type': 'text/plain',
                       'content-length': len(body)}

        try:
            self.conn.request(method, url, body, headers)
        except socket.gaierror as err:
            msg = _("Failed to find address: %s") % err
            raise exception.ZVMXCATRequestFailed(xcatserver=self.host, msg=msg)
        except (socket.error, socket.timeout) as err:
            msg = _("Communication error: %s") % err
            raise exception.ZVMXCATRequestFailed(xcatserver=self.host, msg=msg)

        try:
            res = self.conn.getresponse()
        except Exception as err:
            msg = _("Failed to get response from xCAT: %s") % err
            raise exception.ZVMXCATRequestFailed(xcatserver=self.host, msg=msg)

        msg = res.read()
        resp = {
            'status': res.status,
            'reason': res.reason,
            'message': msg}

        # Only "200" or "201" returned from xCAT can be considered
        # as good status
        err = None
        if method == "POST":
            if res.status != 201:
                err = str(resp)
        else:
            if res.status != 200:
                err = str(resp)

        if err is not None:
            raise exception.ZVMXCATRequestFailed(xcatserver=self.host,
                                                 msg=err)

        return resp


def xcat_request(method, url, body=None, headers={}):
    conn = XCATConnection()
    resp = conn.request(method, url, body, headers)
    return load_xcat_resp(resp['message'])


def jsonloads(jsonstr):
    try:
        return jsonutils.loads(jsonstr)
    except ValueError:
        errmsg = _("xCAT response data is not in JSON format")
        LOG.error(errmsg)
        raise exception.ZVMDriverError(msg=errmsg)


@contextlib.contextmanager
def expect_invalid_xcat_resp_data():
    """Catch exceptions when using xCAT response data."""
    try:
        yield
    except (ValueError, TypeError, IndexError, AttributeError,
            KeyError) as err:
        raise exception.ZVMInvalidXCATResponseDataError(msg=err)


def wrap_invalid_xcat_resp_data_error(function):
    """Catch exceptions when using xCAT response data."""

    @functools.wraps(function)
    def decorated_function(*arg, **kwargs):
        try:
            return function(*arg, **kwargs)
        except (ValueError, TypeError, IndexError, AttributeError,
                KeyError) as err:
            raise exception.ZVMInvalidXCATResponseDataError(msg=err)

    return decorated_function


@contextlib.contextmanager
def ignore_errors():
    """Only execute the clauses and ignore the results."""

    try:
        yield
    except Exception as err:
        LOG.debug(_("Ignore an error: %s") % err)
        pass


@contextlib.contextmanager
def except_xcat_call_failed_and_reraise(exc, **kwargs):
    """Catch all kinds of xCAT call failure and reraise.

    exc: the exception that would be raised.
    """
    try:
        yield
    except (exception.ZVMXCATRequestFailed,
            exception.ZVMInvalidXCATResponseDataError,
            exception.ZVMXCATInternalError) as err:
        kwargs['msg'] = err
        raise exc(**kwargs)


def convert_to_mb(s):
    """Convert memory size from GB to MB."""
    s = s.upper()
    try:
        if s.endswith('G'):
            return float(s[:-1].strip()) * 1024
        else:
            return float(s[:-1].strip())
    except (IndexError, ValueError, KeyError, TypeError) as e:
        errmsg = _("Invalid memory format: %s") % e
        raise exception.ZVMDriverError(msg=errmsg)


@wrap_invalid_xcat_resp_data_error
def translate_xcat_resp(rawdata, dirt):
    """Translate xCAT response JSON stream to a python dictionary.

    xCAT response example:
    node: keyword1: value1\n
    node: keyword2: value2\n
    ...
    node: keywordn: valuen\n

    Will return a python dictionary:
    {keyword1: value1,
     keyword2: value2,
     ...
     keywordn: valuen,}

    """
    data_list = rawdata.split("\n")

    data = {}

    for ls in data_list:
        for k in dirt.keys():
            if ls.__contains__(dirt[k]):
                data[k] = ls[(ls.find(dirt[k]) + len(dirt[k])):].strip()
                break

    if data == {}:
        msg = _("No value matched with keywords. Raw Data: %(raw)s; "
                "Keywords: %(kws)s") % {'raw': rawdata, 'kws': str(dirt)}
        raise exception.ZVMInvalidXCATResponseDataError(msg=msg)

    return data


def mapping_power_stat(power_stat):
    """Translate power state to OpenStack defined constants."""
    return const.ZVM_POWER_STAT.get(power_stat, power_state.NOSTATE)


@wrap_invalid_xcat_resp_data_error
def load_xcat_resp(message):
    """Abstract information from xCAT REST response body.

    As default, xCAT response will in format of JSON and can be
    converted to Python dictionary, would looks like:
    {"data": [{"info": [info,]}, {"data": [data,]}, ..., {"error": [error,]}]}

    Returns a Python dictionary, looks like:
    {'info': [info,],
     'data': [data,],
     ...
     'error': [error,]}

    """
    resp_list = jsonloads(message)['data']
    keys = const.XCAT_RESPONSE_KEYS

    resp = {}

    for k in keys:
        resp[k] = []

    for d in resp_list:
        for k in keys:
            if d.get(k) is not None:
                resp[k].append(d.get(k))

    err = resp.get('error')
    if err != []:
        for e in err:
            if _is_warning(str(e)):
                # ignore known warnings
                continue
            else:
                raise exception.ZVMXCATInternalError(msg=message)

    _log_warnings(resp)

    return resp


def _log_warnings(resp):
    for msg in (resp['info'], resp['node'], resp['data']):
        msgstr = str(msg)
        if 'warn' in msgstr.lower():
            LOG.warn(_("Warning from xCAT: %s") % msgstr)


def _is_warning(err_str):
    ignore_list = (
        'Warning: the RSA host key for',
        'Warning: Permanently added',
        'WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED',
    )

    for im in ignore_list:
        if im in err_str:
            return True

    return False


def volume_in_mapping(mount_device, block_device_info):
    block_device_list = [block_device.strip_dev(vol['mount_device'])
                         for vol in
                         driver.block_device_info_get_mapping(
                             block_device_info)]
    swap = driver.block_device_info_get_swap(block_device_info)
    if driver.swap_is_usable(swap):
        block_device_list.append(
            block_device.strip_dev(swap['device_name']))
    block_device_list += [block_device.strip_dev(ephemeral['device_name'])
                          for ephemeral in
                          driver.block_device_info_get_ephemerals(
                              block_device_info)]

    LOG.debug(_("block_device_list %s"), block_device_list)
    return block_device.strip_dev(mount_device) in block_device_list


def get_host():
    return ''.join([os.environ["USER"], '@', CONF.my_ip])


def get_userid(node_name):
    """Returns z/VM userid for the xCAT node."""
    url = XCATUrl().lsdef_node(''.join(['/', node_name]))
    info = xcat_request('GET', url)['info']

    with expect_invalid_xcat_resp_data():
        for s in info[0]:
            if s.__contains__('userid='):
                return s.strip().rpartition('=')[2]


def xdsh(node, commands):
    """"Run command on xCAT node."""
    LOG.debug(_('Run command %(cmd)s on xCAT node %(node)s') %
              {'cmd': commands, 'node': node})

    def xdsh_execute(node, commands):
        """Invoke xCAT REST API to execute command on node."""
        xdsh_commands = 'command=%s' % commands
        body = [xdsh_commands]
        url = XCATUrl().xdsh('/' + node)
        return xcat_request("PUT", url, body)

    with except_xcat_call_failed_and_reraise(
            exception.ZVMXCATXdshFailed):
        res_dict = xdsh_execute(node, commands)

    return res_dict


def punch_file(node, fn, fclass):
    body = [" ".join(['--punchfile', fn, fclass, get_host()])]
    url = XCATUrl().chvm('/' + node)

    try:
        xcat_request("PUT", url, body)
    except Exception as err:
        with excutils.save_and_reraise_exception():
            LOG.error(_('Punch file to %(node)s failed: %(msg)s') %
                      {'node': node, 'msg': err})
    finally:
        os.remove(fn)


def punch_adminpass_file(instance_path, instance_name, admin_password):
    adminpass_fn = ''.join([instance_path, '/adminpwd.sh'])
    _generate_adminpass_file(adminpass_fn, admin_password)
    punch_file(instance_name, adminpass_fn, 'X')


def punch_xcat_auth_file(instance_path, instance_name):
    """Make xCAT MN authorized by virtual machines."""
    mn_pub_key = get_mn_pub_key()
    auth_fn = ''.join([instance_path, '/xcatauth.sh'])
    _generate_auth_file(auth_fn, mn_pub_key)
    punch_file(instance_name, auth_fn, 'X')


def punch_eph_info_file(instance_path, instance_name, vdev=None, fmt=None,
                         mntdir=None):
    if not fmt:
        fmt = CONF.default_ephemeral_format or const.DEFAULT_EPH_DISK_FMT
    eph_fn = ''.join([instance_path, '/eph.disk'])
    _generate_ephinfo_file(eph_fn, vdev, fmt, mntdir)
    punch_file(instance_name, eph_fn, 'X')


def generate_vdev(base, offset=1):
    """Generate virtual device number base on base vdev.

    :param base: base virtual device number, string of 4 bit hex.
    :param offset: offset to base, integer.

    :output: virtual device number, string of 4 bit hex.
    """
    vdev = hex(int(base, 16) + offset)[2:]
    return vdev.rjust(4, '0')


def generate_eph_vdev(offset=1):
    """Generate virtual device number for ephemeral disks.

    :parm offset: offset to zvm_user_adde_vdev.

    :output: virtual device number, string of 4 bit hex.
    """
    vdev = generate_vdev(CONF.zvm_user_adde_vdev, offset + 1)
    if offset >= 0 and offset < 254:
        return vdev
    else:
        msg = _("Invalid virtual device number for ephemeral disk: %s") % vdev
        LOG.error(msg)
        raise exception.ZVMDriverError(msg=msg)


def _generate_ephinfo_file(fname, vdev, fmt, mntdir):
    vdev = vdev or CONF.zvm_user_adde_vdev
    mntdir = mntdir or CONF.zvm_default_ephemeral_mntdir

    lines = [
        '# xCAT Init\n',
        'action=addMdisk\n',
        'vaddr=' + vdev + '\n',
        'filesys=' + fmt + '\n',
        'mntdir=' + mntdir + '\n'
        ]

    with open(fname, 'w') as genfile:
        try:
            genfile.writelines(lines)
        except Exception as err:
            with excutils.save_and_reraise_exception():
                LOG.error(_('Generate ephemeral info file failed: %s') % err)


def _generate_auth_file(fn, pub_key):
    lines = ['#!/bin/bash\n',
    'echo "%s" >> /root/.ssh/authorized_keys' % pub_key]
    with open(fn, 'w') as f:
        f.writelines(lines)


def _generate_adminpass_file(fn, admin_password):
    lines = ['#! /bin/bash\n',
    'echo %s|passwd --stdin root' % admin_password]
    with open(fn, 'w') as f:
        f.writelines(lines)


@wrap_invalid_xcat_resp_data_error
def get_mn_pub_key():
    cmd = 'cat /root/.ssh/id_rsa.pub'
    resp = xdsh(CONF.zvm_xcat_master, cmd)
    key = resp['data'][0][0]
    start_idx = key.find('ssh-rsa')
    key = key[start_idx:]
    return key


def parse_os_version(os_version):
    """Separate os and version from os_version.
    Possible return value are only:
    ('rhel', x.y) and ('sles', x.y) where x.y may not be digits
    """
    supported = {'rhel': ['rhel', 'redhat', 'red hat'],
                'sles': ['suse', 'sles']}
    os_version = os_version.lower()
    for distro, patterns in supported.items():
        for i in patterns:
            if os_version.startswith(i):
                # Not guarrentee the version is digital
                return distro, os_version.split(i, 2)[1]
    else:
        raise exception.ZVMImageError(msg='Unknown os_version property')


class PathUtils(object):
    def open(self, path, mode):
        """Wrapper on __builin__.open used to simplify unit testing."""
        import __builtin__
        return __builtin__.open(path, mode)

    def _get_image_tmp_path(self):
        image_tmp_path = os.path.normpath(CONF.zvm_image_tmp_path)
        if not os.path.exists(image_tmp_path):
            LOG.debug(_('Creating folder %s for image temp files') %
                     image_tmp_path)
            os.makedirs(image_tmp_path)
        return image_tmp_path

    def get_bundle_tmp_path(self, tmp_file_fn):
        bundle_tmp_path = os.path.join(self._get_image_tmp_path(), "spawn_tmp",
                                       tmp_file_fn)
        if not os.path.exists(bundle_tmp_path):
            LOG.debug(_('Creating folder %s for image bundle temp file') %
                      bundle_tmp_path)
            os.makedirs(bundle_tmp_path)
        return bundle_tmp_path

    def get_img_path(self, bundle_file_path, image_name):
        return os.path.join(bundle_file_path, image_name)

    def _get_snapshot_path(self):
        snapshot_folder = os.path.join(self._get_image_tmp_path(),
                                       "snapshot_tmp")
        if not os.path.exists(snapshot_folder):
            LOG.debug(_("Creating the snapshot folder %s") % snapshot_folder)
            os.makedirs(snapshot_folder)
        return snapshot_folder

    def _get_punch_path(self):
        punch_folder = os.path.join(self._get_image_tmp_path(), "punch_tmp")
        if not os.path.exists(punch_folder):
            LOG.debug(_("Creating the punch folder %s") % punch_folder)
            os.makedirs(punch_folder)
        return punch_folder

    def _make_short_time_stamp(self):
        # tmp_file_fn = time.strftime('%d%H%M%S',
        #                            time.localtime(time.time()))
        # return tmp_file_fn
        return '0'

    def get_punch_time_path(self):
        punch_time_path = os.path.join(self._get_punch_path(),
                                       self._make_short_time_stamp())
        if not os.path.exists(punch_time_path):
            LOG.debug(_("Creating punch time folder %s") % punch_time_path)
            os.makedirs(punch_time_path)
        return punch_time_path

    def get_spawn_folder(self):
        spawn_folder = os.path.join(self._get_image_tmp_path(), "spawn_tmp")
        if not os.path.exists(spawn_folder):
            LOG.debug(_("Creating the spawn folder %s") % spawn_folder)
            os.makedirs(spawn_folder)
        return spawn_folder

    def make_time_stamp(self):
        tmp_file_fn = time.strftime('%Y%m%d%H%M%S',
                                            time.localtime(time.time()))
        return tmp_file_fn

    def get_snapshot_time_path(self):
        snapshot_time_path = os.path.join(self._get_snapshot_path(),
                                          self.make_time_stamp())
        if not os.path.exists(snapshot_time_path):
            LOG.debug(_('Creating folder %s for image bundle temp file') %
                      snapshot_time_path)
            os.makedirs(snapshot_time_path)
        return snapshot_time_path

    def clean_temp_folder(self, tmp_file_fn):
        if os.path.isdir(tmp_file_fn):
            LOG.debug(_('Removing existing folder %s '), tmp_file_fn)
            shutil.rmtree(tmp_file_fn)

    def _get_instances_path(self):
        return os.path.normpath(CONF.instances_path)

    def get_instance_path(self, os_node, instance_name):
        instance_folder = os.path.join(self._get_instances_path(), os_node,
                                       instance_name)
        if not os.path.exists(instance_folder):
            LOG.debug(_("Creating the instance path %s") % instance_folder)
            os.makedirs(instance_folder)
        return instance_folder

    def get_console_log_path(self, os_node, instance_name):
        return os.path.join(self.get_instance_path(os_node, instance_name),
                            "console.log")


class NetworkUtils(object):
    """Utilities for z/VM network operator."""

    def validate_ip_address(self, ip_address):
        """Check whether ip_address is valid."""
        # TODO(Leon): check IP address format
        pass

    def validate_network_mask(self, mask):
        """Check whether mask is valid."""
        # TODO(Leon): check network mask format
        pass

    def create_network_configuration_files(self, file_path, network_info,
                                           base_vdev, os_type):
        """Generate network configuration files to instance."""
        device_num = 0
        cfg_files = []
        cmd_strings = ''
        udev_cfg_str = ''
        dns_cfg_str = ''
        route_cfg_str = ''
        cmd_str = None
        cfg_str = ''
        # Red Hat
        file_path_rhel = '/etc/sysconfig/network-scripts/'
        # SuSE
        file_path_sles = '/etc/sysconfig/network/'
        file_name_route = file_path_sles + 'routes'

        # Check the OS type
        if (os_type == 'sles'):
            file_path = file_path_sles
        else:
            file_path = file_path_rhel
        file_name_dns = '/etc/resolv.conf'
        for vif in network_info:
            file_name = 'ifcfg-eth' + str(device_num)
            network = vif['network']
            (cfg_str, cmd_str, dns_str, route_str) =\
                self.generate_network_configration(network,
                    base_vdev, device_num, os_type)
            LOG.debug(_('Network configure file content is: %s') % cfg_str)
            target_net_conf_file_name = file_path + file_name
            cfg_files.append((target_net_conf_file_name, cfg_str))
            udev_cfg_str += self.generate_udev_configuration(device_num,
                                '0.0.' + str(base_vdev).zfill(4))
            if cmd_str is not None:
                cmd_strings += cmd_str
            if len(dns_str) > 0:
                dns_cfg_str += dns_str
            if len(route_str) > 0:
                route_cfg_str += route_str
            base_vdev = str(hex(int(base_vdev, 16) + 3))[2:]
            device_num += 1

        if len(dns_cfg_str) > 0:
            cfg_files.append((file_name_dns, dns_cfg_str))
        if os_type == 'sles':
            udev_file_name = '/etc/udev/rules.d/70-persistent-net.rules'
            cfg_files.append((udev_file_name, udev_cfg_str))
            if len(route_cfg_str) > 0:
                cfg_files.append((file_name_route, route_cfg_str))

        return cfg_files, cmd_strings

    def generate_network_configration(self, network, vdev, device_num,
                                      os_type):
        """Generate network configuration items."""
        ip_v4 = netmask_v4 = gateway_v4 = broadcast_v4 = ''
        subchannels = None
        device = None
        cidr_v4 = None
        cmd_str = None
        dns_str = ''
        route_str = ''

        subnets_v4 = [s for s in network['subnets'] if s['version'] == 4]

        if len(subnets_v4[0]['ips']) > 0:
            ip_v4 = subnets_v4[0]['ips'][0]['address']
        if len(subnets_v4[0]['dns']) > 0:
            for dns in subnets_v4[0]['dns']:
                dns_str += 'nameserver ' + dns['address'] + '\n'

        netmask_v4 = str(subnets_v4[0].as_netaddr().netmask)
        gateway_v4 = subnets_v4[0]['gateway']['address']
        broadcast_v4 = str(subnets_v4[0].as_netaddr().broadcast)
        device = "eth" + str(device_num)
        address_read = str(vdev).zfill(4)
        address_write = str(hex(int(vdev, 16) + 1))[2:].zfill(4)
        address_data = str(hex(int(vdev, 16) + 2))[2:].zfill(4)
        subchannels = '0.0.%s' % address_read.lower()
        subchannels += ',0.0.%s' % address_write.lower()
        subchannels += ',0.0.%s' % address_data.lower()

        cfg_str = 'DEVICE=\"' + device + '\"\n' + 'BOOTPROTO=\"static\"\n'
        cfg_str += 'BROADCAST=\"' + broadcast_v4 + '\"\n'
        cfg_str += 'GATEWAY=\"' + gateway_v4 + '\"\nIPADDR=\"' + ip_v4 + '\"\n'
        cfg_str += 'NETMASK=\"' + netmask_v4 + '\"\n'
        cfg_str += 'NETTYPE=\"qeth\"\nONBOOT=\"yes\"\n'
        cfg_str += 'PORTNAME=\"PORT' + address_read + '\"\n'
        cfg_str += 'OPTIONS=\"layer2=1\"\n'
        cfg_str += 'SUBCHANNELS=\"' + subchannels + '\"\n'

        if os_type == 'sles':
            cidr_v4 = self._get_cidr_from_ip_netmask(ip_v4, netmask_v4)
            cmd_str = 'qeth_configure -l 0.0.%s ' % address_read.lower()
            cmd_str += '0.0.%(write)s 0.0.%(data)s 1\n' % {'write':
                           address_write.lower(), 'data': address_data.lower()}
            cfg_str = "BOOTPROTO=\'static\'\nIPADDR=\'%s\'\n" % cidr_v4
            cfg_str += "BROADCAST=\'%s\'\n" % broadcast_v4
            cfg_str += "STARTMODE=\'onboot\'\n"
            cfg_str += "NAME=\'OSA Express Network card (%s)\'\n" %\
                       address_read
            route_str += 'default %s - -\n' % gateway_v4

        return cfg_str, cmd_str, dns_str, route_str

    def generate_udev_configuration(self, device, dev_channel):
        cfg_str = 'SUBSYSTEM==\"net\", ACTION==\"add\", DRIVERS==\"qeth\",'
        cfg_str += ' KERNELS==\"%s\", ATTR{type}==\"1\",' % dev_channel
        cfg_str += ' KERNEL==\"eth*\", NAME=\"eth%s\"\n' % device

        return cfg_str

    def _get_cidr_from_ip_netmask(self, ip, netmask):
        netmask_fields = netmask.split('.')
        bin_str = ''
        for octet in netmask_fields:
            bin_str += bin(int(octet))[2:].zfill(8)
        mask = str(len(bin_str.rstrip('0')))
        cidr_v4 = ip + '/' + mask
        return cidr_v4