commit a9b3cd7f (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The same function is used by idmap, gss and blocklayout code. Make it
generic.
Signed-off-by: NPeng Tao <peng_tao@emc.com>
Signed-off-by: NJim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the case labels the same indent as the switch.

git diff -w shows 80 column line reflowing.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a couple of instances where we were exiting the RPC client on
arbitrary signals. We should only do so on fatal signals.

Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There can be an infinite loop if gss_create_upcall() is called without
the userspace program running.  To prevent this, we return -EACCES if
we notice that pipe_version hasn't changed (indicating that the pipe
has not been opened).
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make the value in gm_upcall_enctypes just the enctype values.
This allows the values to be used more easily elsewhere.
Signed-off-by: NKevin Coffman <kwc@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make the value in gm_upcall_enctypes just the enctype values.
This allows the values to be used more easily elsewhere.
Signed-off-by: NKevin Coffman <kwc@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Now that all client-side XDR decoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC res *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each decoder function.

This is a refactoring change.  It should not cause different behavior.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.

Also, all the client-side encoder functions return 0 now, making a
return value superfluous.  Take this opportunity to convert them to
return void instead.

This is a refactoring change.  It should not cause different behavior.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If rpc_queue_upcall() adds a new upcall to the rpci->pipe list just
after rpc_pipe_release calls rpc_purge_list(), but before it calls
gss_pipe_release (as rpci->ops->release_pipe(inode)), then the latter
will free a message without deleting it from the rpci->pipe list.

We will be left with a freed object on the rpc->pipe list.  Most
frequent symptoms are kernel crashes in rpc.gssd system calls on the
pipe in question.
Reported-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

There is no need to delete the gss context separately from the rest
of the security context information, and doing so gives rise to a
an rcu_dereference_check() warning.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This will allow us to save the original generic cred in rpc_message, so
that if we migrate from one server to another, we can generate a new bound
cred without having to punt back to the NFS layer.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that the rpc.gssd daemon can explicitly tell us that the key expired,
we should cache that information to avoid spamming gssd.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Again, we can deadlock if the memory reclaim triggers a writeback that
requires a rpcsec_gss credential lookup.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The text based upcall now indicates which Kerberos encryption types are
supported by the kernel rpcsecgss code.  This is used by gssd to
determine which encryption types it should attempt to negotiate
when creating a context with a server.

The server principal's database and keytab encryption types are
what limits what it should negotiate.  Therefore, its keytab
should be created with only the enctypes listed by this file.

Currently we support des-cbc-crc, des-cbc-md4 and des-cbc-md5
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make the client and server code consistent regarding the extra buffer
space made available for the auth code when wrapping data.

Add some comments/documentation about the available buffer space
in the xdr_buf head and tail when gss_wrap is called.

Add a compile-time check to make sure we are not exceeding the available
buffer space.

Add a central function to shift head data.
Signed-off-by: NKevin Coffman <kwc@citi.umich.edu>
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The function alloc_enc_pages() currently fails to release the pointer
rqstp->rq_enc_pages in the error path.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: stable@kernel.org

The kernel currently ignores any error code sent by gssd and always
considers it to be -EACCES. In order to better handle the situation of
an expired KRB5 TGT, the kernel needs to be able to parse and deal with
the errors that gssd sends. Aside from -EACCES the only error we care
about is -EKEYEXPIRED, which we're using to indicate that the upper
layers should retry the call a little later.

To maintain backward compatibility with older gssd's, any error other
than -EKEYEXPIRED is interpreted as -EACCES.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix auth_gss printk format warning:

net/sunrpc/auth_gss/auth_gss.c:660: warning: format '%ld' expects type 'long int', but argument 3 has type 'ssize_t'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When handling the gssd downcall, the kernel should distinguish between a
successful downcall that contains an error code and a failed downcall
(i.e. where the parsing failed or some other sort of problem occurred).

In the former case, gss_pipe_downcall should be returning the number of
bytes written to the pipe instead of an error. In the event of other
errors, we generally want the initiating task to retry the upcall so
we set msg.errno to -EAGAIN. An unexpected error code here is a bug
however, so BUG() in that case.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The pointer to struct gss_auth parameter in gss_add_msg is not really needed
after commit 5b7ddd4a. Zap it.
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

IS_ERR returns 1 or 0, PTR_ERR returns the error value.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

As the module uses rcu_call() we should make sure that all
rcu callback has been completed before removing the code.
Signed-off-by: NJesper Dangaard Brouer <hawk@comx.dk>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch extends the new upcall with a "service" field that currently
can have 2 values: "*" or "nfs". These values specify matching rules for
principals in the keytab file. The "*" means that gssd is allowed to use
"root", "nfs", or "host" keytab entries while the other option requires
"nfs".

Restricting gssd to use the "nfs" principal is needed for when the
server performs a callback to the client.  The server in this case has
to authenticate itself as an "nfs" principal.

We also need "service" field to distiguish between two client-side cases
both currently using a uid of 0: the case of regular file access by the
root user, and the case of state-management calls (such as setclientid)
which should use a keytab for authentication.  (And the upcall should
fail if an appropriate principal can't be found.)

Signed-off: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch extends the new upcall by adding a "target" field
communicating who we want to authenticate to (equivalently, the service
principal that we want to acquire a ticket for).

Signed-off: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Implement the new upcall.  We decide which version of the upcall gssd
will use (new or old), by creating both pipes (the new one named "gssd",
the old one named after the mechanism (e.g., "krb5")), and then waiting
to see which version gssd actually opens.

We don't permit pipes of the two different types to be opened at once.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Keep a pointer to the inode that the message is queued on in the struct
gss_upcall_msg.  This will be convenient, especially after we have a
choice of two pipes that an upcall could be queued on.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Introduce a global variable pipe_version which will eventually be used
to keep track of which version of the upcall gssd is using.

For now, though, it only keeps track of whether any pipe is open or not;
it is negative if not, zero if one is opened.  We use this to wait for
the first gssd to open a pipe.

(Minor digression: note this waits only for the very first open of any
pipe, not for the first open of a pipe for a given auth; thus we still
need the RPC_PIPE_WAIT_FOR_OPEN behavior to wait for gssd to open new
pipes that pop up on subsequent mounts.)
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Keep a count of the number of pipes open plus the number of messages on
a pipe.  This count isn't used yet.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I want to add a little more code here, so it'll be convenient to have
this flatter.

Also, I'll want to add another error condition, so it'll be more
convenient to return -ENOMEM than NULL in the error case.  The only
caller is already converting NULL to -ENOMEM anyway.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We'll want to call this from elsewhere soon.  And this is a bit nicer
anyway.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We're just about to kfree() gss_auth, so there's no point to setting any
of its fields.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There's a bit of a chicken and egg problem when it comes to destroying
auth_gss credentials. When we destroy the last instance of a GSSAPI RPC
credential, we should send a NULL RPC call with a GSS procedure of
RPCSEC_GSS_DESTROY to hint to the server that it can destroy those
creds.

This isn't happening because we're setting clearing the uptodate bit on
the credentials and then setting the operations to the gss_nullops. When
we go to do the RPC call, we try to refresh the creds. That fails with
-EACCES and the call fails.

Fix this by not clearing the UPTODATE bit for the credentials and adding
a new crdestroy op for gss_nullops that just tears down the cred without
trying to destroy the context.

The only difference between this patch and the first one is the removal
of some minor formatting deltas.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Somehow, this escaped the previous purge. There should be no need to keep
any extra locks in the XDR callbacks.

The NFS client XDR code only writes into private objects, whereas all reads
of shared objects are confined to fields that do not change, such as
filehandles...

Ditto for lockd, the NFSv2/v3 client mount code, and rpcbind.

The nfsd XDR code may require the BKL, but since it does a synchronous RPC
call from a thread that already holds the lock, that issue is moot.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There used to be a print_hexl() function that used isprint(), now gone.
I don't know why NFS_NGROUPS and CA_RUN_AS_MACHINE were here.

I also don't know why another #define that's actually used was marked
"unused".
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>