The NFSv4 SECINFO operation returns a list of security flavors that
the server supports for a particular share. An NFSv4 client is
supposed to pick a pseudoflavor it supports that corresponds to one
of the flavors returned by the server.
GSS flavors in this list have a GSS tuple that identify a specific
GSS pseudoflavor.
Currently our client ignores the GSS tuple's "qop" value. A
matching pseudoflavor is chosen based only on the OID and service
value.
So far this omission has not had much effect on Linux. The NFSv4
protocol currently supports only one qop value: GSS_C_QOP_DEFAULT,
also known as zero.
However, if an NFSv4 server happens to return something other than
zero in the qop field, our client won't notice. This could cause
the client to behave in incorrect ways that could have security
implications.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The current GSS mech switch can find and load GSS pseudoflavor
modules by name ("krb5") or pseudoflavor number ("390003"), but
cannot find GSS modules by GSS tuple:
[ "1.2.840.113554.1.2.2", GSS_C_QOP_DEFAULT, RPC_GSS_SVC_NONE ]
This is important when dealing with a SECINFO request. A SECINFO
reply contains a list of flavors the server supports for the
requested export, but GSS flavors also have a GSS tuple that maps
to a pseudoflavor (like 390003 for krb5).
If the GSS module that supports the OID in the tuple is not loaded,
our client is not able to load that module dynamically to support
that pseudoflavor.
Add a way for the GSS mech switch to load GSS pseudoflavor support
by OID before searching for the pseudoflavor that matches the OID
and service.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
A SECINFO reply may contain flavors whose kernel module is not
yet loaded by the client's kernel. A new RPC client API, called
rpcauth_get_pseudoflavor(), is introduced to do proper checking
for support of a security flavor.
When this API is invoked, the RPC client now tries to load the
module for each flavor first before performing the "is this
supported?" check. This means if a module is available on the
client, but has not been loaded yet, it will be loaded and
registered automatically when the SECINFO reply is processed.
The new API can take a full GSS tuple (OID, QoP, and service).
Previously only the OID and service were considered.
nfs_find_best_sec() is updated to verify all flavors requested in a
SECINFO reply, including AUTH_NULL and AUTH_UNIX. Previously these
two flavors were simply assumed to be supported without consulting
the RPC client.
Note that the replaced version of nfs_find_best_sec() can return
RPC_AUTH_MAXFLAVOR if the server returns a recognized OID but an
unsupported "service" value. nfs_find_best_sec() now returns
RPC_AUTH_UNIX in this case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The NFSv4 SECINFO procedure returns a list of security flavors. Any
GSS flavor also has a GSS tuple containing an OID, a quality-of-
protection value, and a service value, which specifies a particular
GSS pseudoflavor.
For simplicity and efficiency, I'd like to return each GSS tuple
from the NFSv4 SECINFO XDR decoder and pass it straight into the RPC
client.
Define a data structure that is visible to both the NFS client and
the RPC client. Take structure and field names from the relevant
standards to avoid confusion.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I've built with NFSv4 enabled and disabled. This forward
declaration does not seem to be required.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Commit f344f6df "SUNRPC: Auto-load RPC authentication kernel
modules", Mon Mar 20 13:44:08 2006, adds a request_module() call
in rpcauth_create() to auto-load RPC security modules when a ULP
tries to create a credential of that flavor.
In rpcauth_create(), the name of the module to load is built like
this:
request_module("rpc-auth-%u", flavor);
This means that for, say, RPC_AUTH_GSS, request_module() is looking
for a module or alias called "rpc-auth-6".
The GSS module is named "auth_rpcgss", and commit f344f6df does not
add any new module aliases. There is also no such alias provided in
/etc/modprobe.d on my system (Fedora 16). Without this alias, the
GSS module is not loaded on demand.
This is used by rpcauth_create(). The pseudoflavor_to_flavor() call
can return RPC_AUTH_GSS, which is passed to request_module().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server sends us a pathname with more components than the client
limit of NFS4_PATHNAME_MAXCOMPONENTS, more server entries than the client
limit of NFS4_FS_LOCATION_MAXSERVERS, or sends a total number of
fs_locations entries than the client limit of NFS4_FS_LOCATIONS_MAXENTRIES
then we will currently Oops because the limit checks are done _after_ we've
decoded the data into the arrays.
Reported-by: fanchaoting<fanchaoting@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the open_context for the file is not yet fully initialised,
then open recovery cannot succeed, and since nfs4_state_find_open_context
returns an ENOENT, we end up treating the file as being irrecoverable.
What we really want to do, is just defer the recovery until later.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
With unlink is an asynchronous operation in the sillyrename case, it
expects nfs4_async_handle_error() to map the error correctly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that we do CLAIM_FH opens, we may run into situations where we
get a delegation but don't have perfect knowledge of the file path.
When returning the delegation, we might therefore not be able to
us CLAIM_DELEGATE_CUR opens to convert the delegation into OPEN
stateids and locks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Sometimes, we actually _want_ to do open-by-filehandle, for instance
when recovering opens after a network partition, or when called
from nfs4_file_open.
Enable that functionality using a new capability NFS_CAP_ATOMIC_OPEN_V1,
and which is only enabled for NFSv4.1 servers that support it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Follow the practice described in section 8.2.2 of RFC5661: When sending a
read/write or setattr stateid, set the seqid field to zero in order to
signal that the NFS server should apply the most recent locking state.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up the setting of the nfs_server->caps, by shoving it all
into nfs4_server_common_setup().
Then add an 'initial capabilities' field into struct nfs4_minor_version_ops.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Adds logic to ensure that if the server returns a BAD_STATEID,
or other state related error, then we check if the stateid has
already changed. If it has, then rather than start state recovery,
we should just resend the failed RPC call with the new stateid.
Allow nfs4_select_rw_stateid to notify that the stateid is unstable by
having it return -EWOULDBLOCK if an RPC is underway that might change the
stateid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we replay a READ or WRITE call, we should not be changing the
stateid. Currently, we may end up doing so, because the stateid
is only selected at xdr encode time.
This patch ensures that we select the stateid after we get an NFSv4.1
session slot, and that we keep that same stateid across retries.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, we're forcing an unnecessary duplication of the
initial nfs_lock_context in calls to nfs_get_lock_context, since
__nfs_find_lock_context ignores the ctx->lock_context.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the state recovery failed, we want to ensure that the application
doesn't try to use the same file descriptor for more reads or writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If state recovery fails with an ESTALE or a ENOENT, then we shouldn't
keep retrying. Instead, mark the stateid as being invalid and
fail the I/O with an EIO error.
For other operations such as POSIX and BSD file locking, truncate
etc, fail with an EBADF to indicate that this file descriptor is no
longer valid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In the case of a SOFTCONN rpc task, we really want to ensure that it
reports errors like ENETUNREACH back to the caller. Currently, only
some of these errors are being reported back (connect errors are not),
and they are being converted by the RPC layer into EIO.
Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We need to be careful when testing task->tk_waitqueue in
rpc_wake_up_task_queue_locked, because it can be changed while we
are holding the queue->lock.
By adding appropriate memory barriers, we can ensure that it is safe to
test task->tk_waitqueue for equality if the RPC_TASK_QUEUED bit is set.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
In order to be able to safely return the layout in nfs4_proc_setattr,
we need to block new uses of the layout, wait for all outstanding
users of the layout to complete, commit the layout and then return it.
This patch adds a helper in order to do all this safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Note that clearing NFS_INO_LAYOUTCOMMIT is tricky, since it requires
you to also clear the NFS_LSEG_LAYOUTCOMMIT bits from the layout
segments.
The only two sites that need to do this are the ones that call
pnfs_return_layout() without first doing a layout commit.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the
NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations
where the two are out of sync.
The first half of the problem is to ensure that pnfs_layoutcommit_inode
clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg.
We still need to keep the reference to those segments until the RPC call
is finished, so in order to make it clear _where_ those references come
from, we add a helper pnfs_list_write_lseg_done() that cleans up after
pnfs_list_write_lseg.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
Chuck Lever
Trond Myklebust