os-brick/os_brick/initiator/linuxfc.py
Angus Lees dbf77fba10 Trivial rootwrap -> privsep replacement
This change replaces all uses of rootwrap with a trivial privsep-based
equivalent.  This replacement simply executes commands as the privsep
user *without any additional checks*.

There are 2 reasons why this is a reasonable thing to do:

1. We don't have a good workflow for merging rootwrap filter changes
   into parent projects (nova/cinder) for a loosely-coupled library like
   os-brick.

2. The previous situation was also insecure.  The os-brick.filters
   rootwrap config permitted commands like "dd" and "cp" with any
   arguments, as root.  This would have posed only a mild inconvenience
   to an attacker.  With privsep we can at least (in principle) limit
   the commands to the privsep uid/gid and Linux
   capabilities (CAP_SYS_ADMIN by default with this change).

This change addresses the urgency of (1).   Later refactors will take
greater advantage of privsep to address (2).

Change-Id: I0af542eba97d2f89b1c283bf1e1e985d9690f5de
Depends-On: I90dc41bc77993bd83b80c92286e015e14f290b45
 # nova: nova.conf: Set privsep_rootwrap.helper_command
Depends-On: I4e333e73ddfd45c045b9d32dac1506fc25858c4d
 # nova: Add os-brick rootwrap filter for privsep
Depends-On: I8a0b1728cc66c4861f69623b1b16b1f759b57b25
 # cinder: cinder.conf: Set privsep_rootwrap.helper_command
Depends-On: I3b2e337321875cf4abc0ab9b44fe17cf9327d88b
 # cinder: Add os-brick rootwrap filter for privsep
Depends-On: I4299c2fc059807610f83e12a2d470e020930c64c
 # privsep: Switch to msgpack for serialization
Depends-On: Ied1ef4fc945e18516b39d1f20d58425cb633dc74
 # requirements: require oslo.privsep>=1.5.0 for msgpack fix
2016-04-15 15:29:25 +00:00

220 lines
8.4 KiB
Python

# (c) Copyright 2013 Hewlett-Packard Development Company, L.P.
#
# 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.
"""Generic linux Fibre Channel utilities."""
import errno
import os
from oslo_concurrency import processutils as putils
from oslo_log import log as logging
from os_brick.i18n import _LW
from os_brick.initiator import linuxscsi
LOG = logging.getLogger(__name__)
class LinuxFibreChannel(linuxscsi.LinuxSCSI):
def rescan_hosts(self, hbas):
for hba in hbas:
self.echo_scsi_command("/sys/class/scsi_host/%s/scan"
% hba['host_device'], "- - -")
def get_fc_hbas(self):
"""Get the Fibre Channel HBA information."""
out = None
try:
out, _err = self._execute('systool', '-c', 'fc_host', '-v',
run_as_root=True,
root_helper=self._root_helper)
except putils.ProcessExecutionError as exc:
# This handles the case where rootwrap is used
# and systool is not installed
# 96 = nova.cmd.rootwrap.RC_NOEXECFOUND:
if exc.exit_code == 96:
LOG.warning(_LW("systool is not installed"))
return []
except OSError as exc:
# This handles the case where rootwrap is NOT used
# and systool is not installed
if exc.errno == errno.ENOENT:
LOG.warning(_LW("systool is not installed"))
return []
# No FC HBAs were found
if out is None:
return []
lines = out.split('\n')
# ignore the first 2 lines
lines = lines[2:]
hbas = []
hba = {}
lastline = None
for line in lines:
line = line.strip()
# 2 newlines denotes a new hba port
if line == '' and lastline == '':
if len(hba) > 0:
hbas.append(hba)
hba = {}
else:
val = line.split('=')
if len(val) == 2:
key = val[0].strip().replace(" ", "")
value = val[1].strip()
hba[key] = value.replace('"', '')
lastline = line
return hbas
def get_fc_hbas_info(self):
"""Get Fibre Channel WWNs and device paths from the system, if any."""
# Note(walter-boring) modern Linux kernels contain the FC HBA's in /sys
# and are obtainable via the systool app
hbas = self.get_fc_hbas()
if not hbas:
return []
hbas_info = []
for hba in hbas:
wwpn = hba['port_name'].replace('0x', '')
wwnn = hba['node_name'].replace('0x', '')
device_path = hba['ClassDevicepath']
device = hba['ClassDevice']
hbas_info.append({'port_name': wwpn,
'node_name': wwnn,
'host_device': device,
'device_path': device_path})
return hbas_info
def get_fc_wwpns(self):
"""Get Fibre Channel WWPNs from the system, if any."""
# Note(walter-boring) modern Linux kernels contain the FC HBA's in /sys
# and are obtainable via the systool app
hbas = self.get_fc_hbas()
wwpns = []
if hbas:
for hba in hbas:
if hba['port_state'] == 'Online':
wwpn = hba['port_name'].replace('0x', '')
wwpns.append(wwpn)
return wwpns
def get_fc_wwnns(self):
"""Get Fibre Channel WWNNs from the system, if any."""
# Note(walter-boring) modern Linux kernels contain the FC HBA's in /sys
# and are obtainable via the systool app
hbas = self.get_fc_hbas()
if not hbas:
return []
wwnns = []
if hbas:
for hba in hbas:
if hba['port_state'] == 'Online':
wwnn = hba['node_name'].replace('0x', '')
wwnns.append(wwnn)
return wwnns
class LinuxFibreChannelS390X(LinuxFibreChannel):
def get_fc_hbas_info(self):
"""Get Fibre Channel WWNs and device paths from the system, if any."""
hbas = self.get_fc_hbas()
if not hbas:
return []
hbas_info = []
for hba in hbas:
if hba['port_state'] == 'Online':
wwpn = hba['port_name'].replace('0x', '')
wwnn = hba['node_name'].replace('0x', '')
device_path = hba['ClassDevicepath']
device = hba['ClassDevice']
hbas_info.append({'port_name': wwpn,
'node_name': wwnn,
'host_device': device,
'device_path': device_path})
return hbas_info
def configure_scsi_device(self, device_number, target_wwn, lun):
"""Write the LUN to the port's unit_add attribute.
If auto-discovery of Fibre-Channel target ports is
disabled on s390 platforms, ports need to be added to
the configuration.
If auto-discovery of LUNs is disabled on s390 platforms
luns need to be added to the configuration through the
unit_add interface
"""
LOG.debug("Configure lun for s390: device_number=%(device_num)s "
"target_wwn=%(target_wwn)s target_lun=%(target_lun)s",
{'device_num': device_number,
'target_wwn': target_wwn,
'target_lun': lun})
filepath = ("/sys/bus/ccw/drivers/zfcp/%s/%s" %
(device_number, target_wwn))
if not (os.path.exists(filepath)):
zfcp_device_command = ("/sys/bus/ccw/drivers/zfcp/%s/port_rescan" %
(device_number))
LOG.debug("port_rescan call for s390: %s", zfcp_device_command)
try:
self.echo_scsi_command(zfcp_device_command, "1")
except putils.ProcessExecutionError as exc:
LOG.warning(_LW("port_rescan call for s390 failed exit"
" %(code)s, stderr %(stderr)s"),
{'code': exc.exit_code, 'stderr': exc.stderr})
zfcp_device_command = ("/sys/bus/ccw/drivers/zfcp/%s/%s/unit_add" %
(device_number, target_wwn))
LOG.debug("unit_add call for s390 execute: %s", zfcp_device_command)
try:
self.echo_scsi_command(zfcp_device_command, lun)
except putils.ProcessExecutionError as exc:
LOG.warning(_LW("unit_add call for s390 failed exit %(code)s, "
"stderr %(stderr)s"),
{'code': exc.exit_code, 'stderr': exc.stderr})
def deconfigure_scsi_device(self, device_number, target_wwn, lun):
"""Write the LUN to the port's unit_remove attribute.
If auto-discovery of LUNs is disabled on s390 platforms
luns need to be removed from the configuration through the
unit_remove interface
"""
LOG.debug("Deconfigure lun for s390: "
"device_number=%(device_num)s "
"target_wwn=%(target_wwn)s target_lun=%(target_lun)s",
{'device_num': device_number,
'target_wwn': target_wwn,
'target_lun': lun})
zfcp_device_command = ("/sys/bus/ccw/drivers/zfcp/%s/%s/unit_remove" %
(device_number, target_wwn))
LOG.debug("unit_remove call for s390 execute: %s", zfcp_device_command)
try:
self.echo_scsi_command(zfcp_device_command, lun)
except putils.ProcessExecutionError as exc:
LOG.warning(_LW("unit_remove call for s390 failed exit %(code)s, "
"stderr %(stderr)s"),
{'code': exc.exit_code, 'stderr': exc.stderr})