linux.git/net/sunrpc/auth.c, branch v5.0

sunrpc: kernel BUG at kernel/cred.c:825!

2019-01-09T21:54:23+00:00

Init missing debug member magic with CRED_MAGIC.

Signed-off-by: Santosh kumar pradhan 
Reported-by: Dave Jones 
Signed-off-by: Anna Schumaker

SUNRPC discard cr_uid from struct rpc_cred.

2018-12-19T18:52:46+00:00

Just use ->cr_cred->fsuid directly.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: simplify auth_unix.

2018-12-19T18:52:46+00:00

1/ discard 'struct unx_cred'.  We don't need any data that
   is not already in 'struct rpc_cred'.
2/ Don't keep these creds in a hash table.  When a credential
   is needed, simply allocate it.  When not needed, discard it.
   This can easily be faster than performing a lookup on
   a shared hash table.
   As the lookup can happen during write-out, use a mempool
   to ensure forward progress.
   This means that we cannot compare two credentials for
   equality by comparing the pointers, but we never do that anyway.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: remove crbind rpc_cred operation

2018-12-19T18:52:46+00:00

This now always just does get_rpccred(), so we
don't need an operation pointer to know to do that.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: remove generic cred code.

2018-12-19T18:52:46+00:00

This is no longer used.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

2018-12-19T18:52:46+00:00

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown 
Acked-by: J. Bruce Fields 
Signed-off-by: Anna Schumaker

NFS: move credential expiry tracking out of SUNRPC into NFS.

2018-12-19T18:52:45+00:00

NFS needs to know when a credential is about to expire so that
it can modify write-back behaviour to finish the write inside the
expiry time.
It currently uses functions in SUNRPC code which make use of a
fairly complex callback scheme and flags in the generic credientials.

As I am working to discard the generic credentials, this has to change.

This patch moves the logic into NFS, in part by finding and caching
the low-level credential in the open_context.  We then make direct
cred-api calls on that.

This makes the code much simpler and removes a dependency on generic
rpc credentials.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: add side channel to use non-generic cred for rpc call.

2018-12-19T18:52:45+00:00

The credential passed in rpc_message.rpc_cred is always a
generic credential except in one instance.
When gss_destroying_context() calls rpc_call_null(), it passes
a specific credential that it needs to destroy.
In this case the RPC acts *on* the credential rather than
being authorized by it.

This special case deserves explicit support and providing that will
mean that rpc_message.rpc_cred is *always* generic, allowing
some optimizations.

So add "tk_op_cred" to rpc_task and "rpc_op_cred" to the setup data.
Use this to pass the cred down from rpc_call_null(), and have
rpcauth_bindcred() notice it and bind it in place.

Credit to kernel test robot  for finding
a bug in earlier version of this patch.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: introduce RPC_TASK_NULLCREDS to request auth_none

2018-12-19T18:52:45+00:00

In almost all cases the credential stored in rpc_message.rpc_cred
is a "generic" credential.  One of the two expections is when an
AUTH_NULL credential is used such as for RPC ping requests.

To improve consistency, don't pass an explicit credential in
these cases, but instead pass NULL and set a task flag,
similar to RPC_TASK_ROOTCREDS, which requests that NULL credentials
be used by default.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred().

2018-12-19T18:52:45+00:00

When NFS creates a machine credential, it is a "generic" credential,
not tied to any auth protocol, and is really just a container for
the princpal name.
This doesn't get linked to a genuine credential until rpcauth_bindcred()
is called.
The lookup always succeeds, so various places that test if the machine
credential is NULL, are pointless.

As a step towards getting rid of generic credentials, this patch gets
rid of generic machine credentials.  The nfs_client and rpc_client
just hold a pointer to a constant principal name.
When a machine credential is wanted, a special static 'struct rpc_cred'
pointer is used. rpcauth_bindcred() recognizes this, finds the
principal from the client, and binds the correct credential.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker