stacd: add authentication support (DHCHAP)

Signed-off-by: Martin Belanger <[email protected]>

Author: Martin Belanger

.github/workflows/pylint.yml

@@ -59,8 +59,8 @@ jobs:
 
       - name: "INSTALL: pip packages"
         run: |
-          pip install pylint --upgrade
-          pip install PyGObject --upgrade
+          pip install pylint
+      #    pip install PyGObject
 
       - name: "BUILD: [libnvme, nvme-stas]"
         uses: BSFishy/[email protected]

coverage.sh.in

@@ -377,7 +377,7 @@ persistent-connections            = false
 zeroconf-connections-persistence  = 1:01
 
 [Controllers]
-controller = transport = tcp ; traddr = localhost ; ; ; kato=31; dhchap-ctrl-secret=not-so-secret
+controller = transport = tcp ; traddr = localhost ; ; ; kato=31; dhchap-ctrl-secret=DHHC-1:00:not-so-secret/not-so-secret/not-so-secret/not-so: ; dhchap-secret=DHHC-1:00:very-secret/very-secret/very-secret/very-secret/:
 controller=transport=tcp;traddr=1.1.1.1
 controller=transport=tcp;traddr=100.100.100.100
 controller=transport=tcp;traddr=2607:f8b0:4002:c2c::71

doc/standard-conf.xml

@@ -376,6 +376,21 @@
                             </listitem>
                         </varlistentry>
 
+                        <varlistentry id='dhchap-secret'>
+                            <term><varname>dhchap-secret=</varname></term>
+                            <listitem>
+                                <para>
+                                    NVMe In-band authentication host secret (i.e. key);
+                                    needs to be in ASCII format as specified in NVMe 2.0
+                                    section 8.13.5.8 Secret representation. If this
+                                    option is not specified, the default is read
+                                    from /etc/stas/sys.conf (see the 'key' parameter
+                                    under the [Host] section). In-band authentication
+                                    is attempted when this is present.
+                                </para>
+                            </listitem>
+                        </varlistentry>
+
                         <varlistentry id='dhchap-ctrl-secret'>
                             <term><varname>dhchap-ctrl-secret=</varname></term>
                             <listitem>

etc/stas/stacd.conf

@@ -235,6 +235,14 @@
 #               This forces the connection to be made on a specific interface
 #               instead of letting the system decide.
 #
+#             dhchap-secret         [OPTIONAL]
+#               NVMe In-band authentication host secret (i.e. key); needs to be
+#               in ASCII format as specified in NVMe 2.0 section 8.13.5.8 Secret
+#               representation. If this option is not specified, the default is
+#               read from /etc/stas/sys.conf (see the 'key' parameter under the
+#               [Host] section). In-band authentication is attempted when this
+#               is present.
+#
 #             dhchap-ctrl-secret    [OPTIONAL]
 #               NVMe In-band authentication controller secret (i.e. key) for
 #               bi-directional authentication; needs to be in ASCII format as

staslib/conf.py

@@ -341,6 +341,7 @@ def get_controllers(self):
             'host-traddr':        [TRADDR],
             'host-iface':         [IFACE],
             'host-nqn':           [NQN],
+            'dhchap-secret':      [KEY],
             'dhchap-ctrl-secret': [KEY],
             'hdr-digest':         [BOOL]
             'data-digest':        [BOOL]

staslib/ctrl.py

@@ -221,23 +221,39 @@ def _do_connect(self):
             host_traddr=self.tid.host_traddr if self.tid.host_traddr else None,
             host_iface=host_iface,
         )
-        self._ctrl.discovery_ctrl_set(self._discovery_ctrl)
+        self._ctrl.discovery_ctrl = self._discovery_ctrl
 
-        # Set the DHCHAP key on the controller
-        # NOTE that this will eventually have to
+        # Set the DHCHAP host key on the controller
+        # NOTE that this may eventually have to
         # change once we have support for AVE (TP8019)
-        ctrl_dhchap_key = self.tid.cfg.get('dhchap-ctrl-secret')
-        if ctrl_dhchap_key and self._nvme_options.dhchap_ctrlkey_supp:
-            has_dhchap_key = hasattr(self._ctrl, 'dhchap_key')
-            if not has_dhchap_key:
+        # This is used for in-band authentication
+        dhchap_host_key = self.tid.cfg.get('dhchap-secret')
+        if dhchap_host_key and self._nvme_options.dhchap_hostkey_supp:
+            try:
+                self._ctrl.dhchap_host_key = dhchap_host_key
+            except AttributeError:
                 logging.warning(
-                    '%s | %s - libnvme-%s does not allow setting the controller DHCHAP key. Please upgrade libnvme.',
+                    '%s | %s - libnvme-%s does not allow setting the host DHCHAP key on the controller. Please upgrade libnvme.',
+                    self.id,
+                    self.device,
+                    defs.LIBNVME_VERSION,
+                )
+
+        # Set the DHCHAP controller key on the controller
+        # NOTE that this may eventually have to
+        # change once we have support for AVE (TP8019)
+        # This is used for bidirectional authentication
+        dhchap_ctrl_key = self.tid.cfg.get('dhchap-ctrl-secret')
+        if dhchap_ctrl_key and self._nvme_options.dhchap_ctrlkey_supp:
+            try:
+                self._ctrl.dhchap_key = dhchap_ctrl_key
+            except AttributeError:
+                logging.warning(
+                    '%s | %s - libnvme-%s does not allow setting the controller DHCHAP key on the controller. Please upgrade libnvme.',
                     self.id,
                     self.device,
                     defs.LIBNVME_VERSION,
                 )
-            else:
-                self._ctrl.dhchap_key = ctrl_dhchap_key
 
         # Audit existing nvme devices. If we find a match, then
         # we'll just borrow that device instead of creating a new one.

staslib/gutil.py

@@ -123,7 +123,7 @@ def resolve_ctrl_async(self, cancellable, controllers_in: list, callback):
         The callback @callback will be called once all hostnames have
         been resolved.
 
-        @param controllers: List of trid.TID
+        @param controllers_in: List of trid.TID
         '''
         pending_resolution_count = 0
         controllers_out = []

staslib/trid.py

@@ -33,6 +33,7 @@ def __init__(self, cid: dict):
             'host-nqn':    str, # [optional]
 
             # Connection parameters
+            'dhchap-secret':      str, # [optional]
             'dhchap-ctrl-secret': str, # [optional]
             'hdr-digest':         str, # [optional]
             'data-digest':        str, # [optional]

utils/nvmet/auth.conf

@@ -0,0 +1,34 @@
+# Config file format: Python, i.e. dict(), list(), int, str, etc...
+# port ids (id) are integers 0...N
+# namespaces are integers 0..N
+# subsysnqn can be integers or strings
+{
+    'ports': [
+        {
+            'id': 1,
+            #'adrfam': 'ipv6',
+            #'traddr': '::',
+            'adrfam': 'ipv4',
+            'traddr': '0.0.0.0',
+            'trsvcid': 4420,
+            'trtype': 'tcp',
+        }
+    ],
+
+    'subsystems': [
+        {
+            'subsysnqn': 'nqn.1988-11.com.dell:PowerSANxxx:01:20210225100113-454f73093ceb4847a7bdfc6e34ae8e28',
+            'port': 1,
+            'namespaces': [1],
+            'allowed_hosts': [
+                {
+                    # Must match with the NQN and key configured on the host
+                    # Key was generated with:
+                    #    nvme gen-dhchap-key ...
+                    'nqn': 'nqn.2014-08.org.nvmexpress:uuid:46ba5037-7ce5-41fa-9452-48477bf00080',
+                    'key': 'DHHC-1:00:2kx1hDTUPdvwtxHYUXFRl8pzn5hYZH7K3Z77IYM4hNN6/fQT:',
+                },
+            ],
+        },
+    ]
+}

utils/nvmet/nvmet.py

@@ -52,19 +52,26 @@ def _get_loaded_nvmet_modules():
     return output
 
 
-def _runcmd(cmd: list, quiet=False):
+def _runcmd(cmd: list, quiet=False, capture_output=False):
     if not quiet:
         print(' '.join(cmd))
     if args.dry_run:
         return
-    subprocess.run(cmd)
+
+    try:
+        cp = subprocess.run(cmd, capture_output=capture_output, text=True)
+    except TypeError:
+        # For older Python versions that don't support "capture_output" or "text"
+        cp = subprocess.run(cmd, stdout=subprocess.PIPE, universal_newlines=True)
+
+    return cp.stdout if capture_output else None
 
 
 def _modprobe(module: str, args: list = None, quiet=False):
     cmd = ['/usr/sbin/modprobe', module]
     if args:
         cmd.extend(args)
-    _runcmd(cmd, quiet)
+    _runcmd(cmd, quiet=quiet)
 
 
 def _mkdir(dname: str):
@@ -93,12 +100,32 @@ def _symlink(port: str, subsysnqn: str):
     link.symlink_to(target)
 
 
-def _create_subsystem(subsysnqn: str) -> str:
+def _symlink_allowed_hosts(hostnqn: str, subsysnqn: str):
+    print(
+        f'$( cd "/sys/kernel/config/nvmet/subsystems/{subsysnqn}/allowed_hosts" && ln -s "../../../hosts/{hostnqn}" "{hostnqn}" )'
+    )
+    if args.dry_run:
+        return
+    target = os.path.join('/sys/kernel/config/nvmet/hosts', hostnqn)
+    link = pathlib.Path(os.path.join('/sys/kernel/config/nvmet/subsystems', subsysnqn, 'allowed_hosts', hostnqn))
+    link.symlink_to(target)
+
+
+def _create_subsystem(subsysnqn: str, allowed_hosts: list) -> str:
     print(f'###{Fore.GREEN} Create subsystem: {subsysnqn}{Style.RESET_ALL}')
     dname = os.path.join('/sys/kernel/config/nvmet/subsystems/', subsysnqn)
     _mkdir(dname)
-    _echo(1, os.path.join(dname, 'attr_allow_any_host'))
-    return dname
+    _echo(0 if allowed_hosts else 1, os.path.join(dname, 'attr_allow_any_host'))
+
+    # Configure all the hosts that are allowed to access this subsystem
+    for host in allowed_hosts:
+        hostnqn = host.get('nqn')
+        hostkey = host.get('key')
+        if all([hostnqn, hostkey]):
+            dname = os.path.join('/sys/kernel/config/nvmet/hosts/', hostnqn)
+            _mkdir(dname)
+            _echo(hostkey, os.path.join(dname, 'dhchap_key'))
+            _symlink_allowed_hosts(hostnqn, subsysnqn)
 
 
 def _create_namespace(subsysnqn: str, id: str, node: str) -> str:
@@ -107,7 +134,6 @@ def _create_namespace(subsysnqn: str, id: str, node: str) -> str:
     _mkdir(dname)
     _echo(node, os.path.join(dname, 'device_path'))
     _echo(1, os.path.join(dname, 'enable'))
-    return dname
 
 
 def _args_valid(id, traddr, trsvcid, trtype, adrfam):
@@ -215,8 +241,9 @@ def create(args):
             str(subsystem.get('port')),
             subsystem.get('namespaces'),
         )
+
         if None not in (subsysnqn, port, namespaces):
-            _create_subsystem(subsysnqn)
+            _create_subsystem(subsysnqn, subsystem.get('allowed_hosts', []))
             for id in namespaces:
                 _create_namespace(subsysnqn, str(id), dev_node)
         else:
@@ -235,10 +262,16 @@ def clean(args):
     if not args.dry_run and os.geteuid() != 0:
         sys.exit(f'Permission denied. You need root privileges to run {os.path.basename(__file__)}.')
 
+    print(f'###{Fore.GREEN} 1st) Remove the symlinks{Style.RESET_ALL}')
     print('rm -f /sys/kernel/config/nvmet/ports/*/subsystems/*')
     for dname in pathlib.Path('/sys/kernel/config/nvmet/ports').glob('*/subsystems/*'):
         _runcmd(['rm', '-f', str(dname)], quiet=True)
 
+    print('rm -f /sys/kernel/config/nvmet/subsystems/*/allowed_hosts/*')
+    for dname in pathlib.Path('/sys/kernel/config/nvmet/subsystems').glob('*/allowed_hosts/*'):
+        _runcmd(['rm', '-f', str(dname)], quiet=True)
+
+    print(f'###{Fore.GREEN} 2nd) Remove directories{Style.RESET_ALL}')
     print('rmdir /sys/kernel/config/nvmet/ports/*')
     for dname in pathlib.Path('/sys/kernel/config/nvmet/ports').glob('*'):
         _runcmd(['rmdir', str(dname)], quiet=True)
@@ -251,6 +284,11 @@ def clean(args):
     for dname in pathlib.Path('/sys/kernel/config/nvmet/subsystems').glob('*'):
         _runcmd(['rmdir', str(dname)], quiet=True)
 
+    print('rmdir /sys/kernel/config/nvmet/hosts/*')
+    for dname in pathlib.Path('/sys/kernel/config/nvmet/hosts').glob('*'):
+        _runcmd(['rmdir', str(dname)], quiet=True)
+
+    print(f'###{Fore.GREEN} 3rd) Unload kernel modules{Style.RESET_ALL}')
     for module in _get_loaded_nvmet_modules():
         _modprobe(module, ['--remove'])