/usr/lib/python3/dist-packages/os_win/utils/storage/initiator/iscsi_utils.py is in python3-os-win 3.0.0-0ubuntu1.
This file is owned by root:root, with mode 0o644.
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#
# All Rights Reserved.
#
# 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 ctypes
import functools
import inspect
import socket
import time
from oslo_log import log as logging
import six
from os_win import _utils
from os_win import constants
from os_win import exceptions
from os_win.utils.storage import diskutils
from os_win.utils import win32utils
from os_win.utils.winapi import constants as w_const
from os_win.utils.winapi.errmsg import iscsierr
from os_win.utils.winapi import libs as w_lib
from os_win.utils.winapi.libs import iscsidsc as iscsi_struct
iscsidsc = w_lib.get_shared_lib_handle(w_lib.ISCSIDSC)
LOG = logging.getLogger(__name__)
def _get_buff(size, item_type):
buff = (ctypes.c_ubyte * size)()
return ctypes.cast(buff, ctypes.POINTER(item_type))
def ensure_buff_and_retrieve_items(struct_type,
func_requests_buff_sz=True,
parse_output=True):
# The iscsidsc.dll functions retrieving data accept a buffer, which will
# be used for passing back the requested data. If the buffer is too small,
# the error code will show it. In this case, the decorator will adjust the
# buffer size based on the buffer size or the element count provided by
# the function, attempting to call it again.
#
# We need to provide a buffer large enough to store the retrieved data.
# This may be more than the size of the retrieved structures as those
# may contain pointers. We're also casting the buffer to the appropriate
# type as function parameters are validated.
def wrapper(f):
@functools.wraps(f)
def inner(*args, **kwargs):
call_args = inspect.getcallargs(f, *args, **kwargs)
call_args['element_count'] = ctypes.c_ulong(0)
call_args['buff'] = _get_buff(0, struct_type)
call_args['buff_size'] = ctypes.c_ulong(0)
while True:
try:
ret_val = f(**call_args)
if parse_output:
return _get_items_from_buff(
call_args['buff'],
struct_type,
call_args['element_count'].value)
else:
return ret_val
except exceptions.Win32Exception as ex:
if (ex.error_code & 0xFFFF ==
w_const.ERROR_INSUFFICIENT_BUFFER):
if func_requests_buff_sz:
buff_size = call_args['buff_size'].value
else:
buff_size = (ctypes.sizeof(struct_type) *
call_args['element_count'].value)
call_args['buff'] = _get_buff(buff_size, struct_type)
else:
raise
return inner
return wrapper
def _get_items_from_buff(buff, item_type, element_count):
array_type = item_type * element_count
return ctypes.cast(buff, ctypes.POINTER(array_type)).contents
retry_decorator = functools.partial(
_utils.retry_decorator,
max_retry_count=10,
exceptions=exceptions.ISCSIInitiatorAPIException)
class ISCSIInitiatorUtils(object):
_DEFAULT_RESCAN_ATTEMPTS = 3
_MS_IQN_PREFIX = "iqn.1991-05.com.microsoft"
_DEFAULT_ISCSI_PORT = 3260
def __init__(self):
self._win32utils = win32utils.Win32Utils()
self._diskutils = diskutils.DiskUtils()
def _run_and_check_output(self, *args, **kwargs):
kwargs['error_msg_src'] = iscsierr.err_msg_dict
kwargs['failure_exc'] = exceptions.ISCSIInitiatorAPIException
self._win32utils.run_and_check_output(*args, **kwargs)
@ensure_buff_and_retrieve_items(
struct_type=iscsi_struct.PERSISTENT_ISCSI_LOGIN_INFO)
def _get_iscsi_persistent_logins(self, buff=None, buff_size=None,
element_count=None):
self._run_and_check_output(
iscsidsc.ReportIScsiPersistentLoginsW,
ctypes.byref(element_count),
buff,
ctypes.byref(buff_size))
@ensure_buff_and_retrieve_items(
struct_type=ctypes.c_wchar,
func_requests_buff_sz=False,
parse_output=False)
def get_targets(self, forced_update=False, buff=None,
buff_size=None, element_count=None):
"""Get the list of iSCSI targets seen by the initiator service."""
self._run_and_check_output(
iscsidsc.ReportIScsiTargetsW,
forced_update,
ctypes.byref(element_count),
buff)
return self._parse_string_list(buff, element_count.value)
def get_iscsi_initiator(self):
"""Returns the initiator node name."""
try:
buff = (ctypes.c_wchar * (w_const.MAX_ISCSI_NAME_LEN + 1))()
self._run_and_check_output(iscsidsc.GetIScsiInitiatorNodeNameW,
buff)
return buff.value
except exceptions.ISCSIInitiatorAPIException as ex:
LOG.info("The ISCSI initiator node name can't be found. "
"Choosing the default one. Exception: %s", ex)
return "%s:%s" % (self._MS_IQN_PREFIX, socket.getfqdn().lower())
@ensure_buff_and_retrieve_items(
struct_type=ctypes.c_wchar,
func_requests_buff_sz=False,
parse_output=False)
def get_iscsi_initiators(self, buff=None, buff_size=None,
element_count=None):
"""Get the list of available iSCSI initiator HBAs."""
self._run_and_check_output(
iscsidsc.ReportIScsiInitiatorListW,
ctypes.byref(element_count),
buff)
return self._parse_string_list(buff, element_count.value)
@staticmethod
def _parse_string_list(buff, element_count):
buff = ctypes.cast(buff, ctypes.POINTER(ctypes.c_wchar))
str_list = buff[:element_count].strip('\x00')
# Avoid returning a list with an empty string
str_list = str_list.split('\x00') if str_list else []
return str_list
@retry_decorator(error_codes=w_const.ERROR_INSUFFICIENT_BUFFER)
def _login_iscsi_target(self, target_name, portal=None, login_opts=None,
is_persistent=True, initiator_name=None):
session_id = iscsi_struct.ISCSI_UNIQUE_SESSION_ID()
connection_id = iscsi_struct.ISCSI_UNIQUE_CONNECTION_ID()
portal_ref = ctypes.byref(portal) if portal else None
login_opts_ref = ctypes.byref(login_opts) if login_opts else None
initiator_name_ref = (ctypes.c_wchar_p(initiator_name)
if initiator_name else None)
# If the portal is not provided, the initiator will try to reach any
# portal exporting the requested target.
self._run_and_check_output(
iscsidsc.LoginIScsiTargetW,
ctypes.c_wchar_p(target_name),
False, # IsInformationalSession
initiator_name_ref,
ctypes.c_ulong(w_const.ISCSI_ANY_INITIATOR_PORT),
portal_ref,
iscsi_struct.ISCSI_SECURITY_FLAGS(),
None, # Security flags / mappings (using default / auto)
login_opts_ref,
ctypes.c_ulong(0),
None, # Preshared key size / key
is_persistent,
ctypes.byref(session_id),
ctypes.byref(connection_id),
ignored_error_codes=[w_const.ISDSC_TARGET_ALREADY_LOGGED_IN])
return session_id, connection_id
@ensure_buff_and_retrieve_items(
struct_type=iscsi_struct.ISCSI_SESSION_INFO)
def _get_iscsi_sessions(self, buff=None, buff_size=None,
element_count=None):
self._run_and_check_output(
iscsidsc.GetIScsiSessionListW,
ctypes.byref(buff_size),
ctypes.byref(element_count),
buff)
def _get_iscsi_target_sessions(self, target_name, connected_only=True):
sessions = self._get_iscsi_sessions()
return [session for session in sessions
if session.TargetNodeName
and session.TargetNodeName.upper() == target_name.upper()
and (session.ConnectionCount > 0 or not connected_only)]
@retry_decorator(error_codes=(w_const.ISDSC_SESSION_BUSY,
w_const.ISDSC_DEVICE_BUSY_ON_SESSION))
@ensure_buff_and_retrieve_items(
struct_type=iscsi_struct.ISCSI_DEVICE_ON_SESSION,
func_requests_buff_sz=False)
def _get_iscsi_session_devices(self, session_id,
buff=None, buff_size=None,
element_count=None):
self._run_and_check_output(
iscsidsc.GetDevicesForIScsiSessionW,
ctypes.byref(session_id),
ctypes.byref(element_count),
buff)
def _get_iscsi_session_disk_luns(self, session_id):
devices = self._get_iscsi_session_devices(session_id)
luns = [device.ScsiAddress.Lun for device in devices
if (device.StorageDeviceNumber.DeviceType ==
w_const.FILE_DEVICE_DISK)]
return luns
def _get_iscsi_device_from_session(self, session_id, target_lun):
devices = self._get_iscsi_session_devices(session_id)
for device in devices:
if device.ScsiAddress.Lun == target_lun:
return device
def get_device_number_for_target(self, target_name, target_lun,
fail_if_not_found=False):
# This method is preserved as it's used by the Hyper-V Nova driver.
return self.get_device_number_and_path(target_name, target_lun,
fail_if_not_found)[0]
def get_device_number_and_path(self, target_name, target_lun,
fail_if_not_found=False,
retry_attempts=10,
retry_interval=0.1,
rescan_disks=False,
ensure_mpio_claimed=False):
# We try to avoid the need to seek the disk twice as this may take
# unnecessary time.
device_number, device_path = None, None
try:
# Even if the disk was already discovered, under heavy load we may
# fail to locate it, in which case some retries will be performed.
(device_number,
device_path) = self.ensure_lun_available(
target_name, target_lun,
rescan_attempts=retry_attempts,
retry_interval=retry_interval,
rescan_disks=rescan_disks,
ensure_mpio_claimed=ensure_mpio_claimed)
except exceptions.ISCSILunNotAvailable:
if fail_if_not_found:
raise
return device_number, device_path
def get_target_luns(self, target_name):
# We only care about disk LUNs.
sessions = self._get_iscsi_target_sessions(target_name)
if sessions:
luns = self._get_iscsi_session_disk_luns(sessions[0].SessionId)
return luns
return []
def get_target_lun_count(self, target_name):
return len(self.get_target_luns(target_name))
@retry_decorator(error_codes=w_const.ISDSC_SESSION_BUSY)
def _logout_iscsi_target(self, session_id):
self._run_and_check_output(
iscsidsc.LogoutIScsiTarget,
ctypes.byref(session_id))
def _add_static_target(self, target_name, is_persistent=True):
self._run_and_check_output(iscsidsc.AddIScsiStaticTargetW,
ctypes.c_wchar_p(target_name),
None, # Target alias
0, # Target flags
is_persistent,
None, # Predefined mappings
None, # Login opts
None) # Portal group
def _remove_static_target(self, target_name):
ignored_error_codes = [w_const.ISDSC_TARGET_NOT_FOUND]
self._run_and_check_output(iscsidsc.RemoveIScsiStaticTargetW,
ctypes.c_wchar_p(target_name),
ignored_error_codes=ignored_error_codes)
def _get_login_opts(self, auth_username=None, auth_password=None,
auth_type=None, login_flags=0):
if auth_type is None:
auth_type = (constants.ISCSI_CHAP_AUTH_TYPE
if auth_username and auth_password
else constants.ISCSI_NO_AUTH_TYPE)
login_opts = iscsi_struct.ISCSI_LOGIN_OPTIONS()
info_bitmap = 0
if auth_username:
login_opts.Username = six.b(auth_username)
login_opts.UsernameLength = len(auth_username)
info_bitmap |= w_const.ISCSI_LOGIN_OPTIONS_USERNAME
if auth_password:
login_opts.Password = six.b(auth_password)
login_opts.PasswordLength = len(auth_password)
info_bitmap |= w_const.ISCSI_LOGIN_OPTIONS_PASSWORD
login_opts.AuthType = auth_type
info_bitmap |= w_const.ISCSI_LOGIN_OPTIONS_AUTH_TYPE
login_opts.InformationSpecified = info_bitmap
login_opts.LoginFlags = login_flags
return login_opts
def _session_on_path_exists(self, target_sessions, portal_addr,
portal_port, initiator_name):
for session in target_sessions:
connections = session.Connections[:session.ConnectionCount]
uses_requested_initiator = False
# Note(lpetrut): unfortunately, the InitiatorName field of the
# session structure actually represents the initiator node name.
#
# We assume that an active path should present at least one device
# so we get the initiator name from the device info.
if initiator_name:
devices = self._get_iscsi_session_devices(session.SessionId)
for device in devices:
if device.InitiatorName == initiator_name:
uses_requested_initiator = True
break
else:
uses_requested_initiator = True
for conn in connections:
is_requested_path = (uses_requested_initiator and
conn.TargetAddress == portal_addr and
conn.TargetSocket == portal_port)
if is_requested_path:
return True
return False
def _new_session_required(self, target_iqn, portal_addr, portal_port,
initiator_name, mpio_enabled):
login_required = False
sessions = self._get_iscsi_target_sessions(target_iqn)
if not sessions:
login_required = True
elif mpio_enabled:
login_required = not self._session_on_path_exists(
sessions, portal_addr, portal_port, initiator_name)
return login_required
def login_storage_target(self, target_lun, target_iqn, target_portal,
auth_username=None, auth_password=None,
auth_type=None,
mpio_enabled=False,
ensure_lun_available=True,
initiator_name=None,
rescan_attempts=_DEFAULT_RESCAN_ATTEMPTS):
portal_addr, portal_port = _utils.parse_server_string(target_portal)
portal_port = (int(portal_port)
if portal_port else self._DEFAULT_ISCSI_PORT)
known_targets = self.get_targets()
if target_iqn not in known_targets:
self._add_static_target(target_iqn)
login_required = self._new_session_required(
target_iqn, portal_addr, portal_port,
initiator_name, mpio_enabled)
if login_required:
LOG.debug("Logging in iSCSI target %(target_iqn)s",
dict(target_iqn=target_iqn))
# If the multipath flag is set, multiple sessions to the same
# target may be established. MPIO must be enabled and configured
# to claim iSCSI disks, otherwise data corruption can occur.
login_flags = (w_const.ISCSI_LOGIN_FLAG_MULTIPATH_ENABLED
if mpio_enabled else 0)
login_opts = self._get_login_opts(auth_username,
auth_password,
auth_type,
login_flags)
portal = iscsi_struct.ISCSI_TARGET_PORTAL(Address=portal_addr,
Socket=portal_port)
# Note(lpetrut): The iscsidsc documentation states that if a
# persistent session is requested, the initiator should login
# the target only after saving the credentials.
#
# The issue is that although the Microsoft iSCSI service saves
# the credentials, it does not automatically login the target,
# for which reason we have two calls, one meant to save the
# credentials and another one actually creating the session.
self._login_iscsi_target(target_iqn, portal, login_opts,
is_persistent=True)
sid, cid = self._login_iscsi_target(target_iqn, portal,
login_opts,
is_persistent=False)
if ensure_lun_available:
self.ensure_lun_available(target_iqn, target_lun, rescan_attempts)
def ensure_lun_available(self, target_iqn, target_lun,
rescan_attempts=_DEFAULT_RESCAN_ATTEMPTS,
retry_interval=0,
rescan_disks=True,
ensure_mpio_claimed=False):
# This method should be called only after the iSCSI
# target has already been logged in.
for attempt in range(rescan_attempts + 1):
sessions = self._get_iscsi_target_sessions(target_iqn)
for session in sessions:
try:
sid = session.SessionId
device = self._get_iscsi_device_from_session(sid,
target_lun)
if not device:
continue
device_number = device.StorageDeviceNumber.DeviceNumber
device_path = device.LegacyName
if not device_path or device_number in (None, -1):
continue
if ensure_mpio_claimed and not (
self._diskutils.is_mpio_disk(device_number)):
LOG.debug("Disk %s was not claimed yet by the MPIO "
"service.", device_path)
continue
return device_number, device_path
except exceptions.ISCSIInitiatorAPIException:
err_msg = ("Could not find lun %(target_lun)s "
"for iSCSI target %(target_iqn)s.")
LOG.exception(err_msg,
dict(target_lun=target_lun,
target_iqn=target_iqn))
continue
if attempt <= rescan_attempts:
if retry_interval:
time.sleep(retry_interval)
if rescan_disks:
self._diskutils.rescan_disks()
raise exceptions.ISCSILunNotAvailable(target_lun=target_lun,
target_iqn=target_iqn)
@retry_decorator(error_codes=(w_const.ISDSC_SESSION_BUSY,
w_const.ISDSC_DEVICE_BUSY_ON_SESSION))
def logout_storage_target(self, target_iqn):
LOG.debug("Logging out iSCSI target %(target_iqn)s",
dict(target_iqn=target_iqn))
sessions = self._get_iscsi_target_sessions(target_iqn,
connected_only=False)
for session in sessions:
self._logout_iscsi_target(session.SessionId)
self._remove_target_persistent_logins(target_iqn)
self._remove_static_target(target_iqn)
def _remove_target_persistent_logins(self, target_iqn):
persistent_logins = self._get_iscsi_persistent_logins()
for persistent_login in persistent_logins:
if persistent_login.TargetName == target_iqn:
LOG.debug("Removing iSCSI target "
"persistent login: %(target_iqn)s",
dict(target_iqn=target_iqn))
self._remove_persistent_login(persistent_login)
def _remove_persistent_login(self, persistent_login):
self._run_and_check_output(
iscsidsc.RemoveIScsiPersistentTargetW,
ctypes.c_wchar_p(persistent_login.InitiatorInstance),
persistent_login.InitiatorPortNumber,
ctypes.c_wchar_p(persistent_login.TargetName),
ctypes.byref(persistent_login.TargetPortal))
|