SUNRPC: Add rpcauth_list_flavors()

The gss_mech_list_pseudoflavors() function provides a list of
currently registered GSS pseudoflavors.  This list does not include
any non-GSS flavors that have been registered with the RPC client.
nfs4_find_root_sec() currently adds these extra flavors by hand.

Instead, nfs4_find_root_sec() should be looking at the set of flavors
that have been explicitly registered via rpcauth_register().  And,
other areas of code will soon need the same kind of list that
contains all flavors the kernel currently knows about (see below).

Rather than cloning the open-coded logic in nfs4_find_root_sec() to
those new places, introduce a generic RPC function that generates a
full list of registered auth flavors and pseudoflavors.

A new rpc_authops method is added that lists a flavor's
pseudoflavors, if it has any.  I encountered an interesting module
loader loop when I tried to get the RPC client to invoke
gss_mech_list_pseudoflavors() by name.

This patch is a pre-requisite for server trunking discovery, and a
pre-requisite for fixing up the in-kernel mount client to do better
automatic security flavor selection.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2012-07-11 16:31:08 -04:00 committed by Trond Myklebust
parent 56d08fef23
commit 6a1a1e34dc
6 changed files with 80 additions and 9 deletions

View file

@ -13,6 +13,7 @@
#include <linux/errno.h>
#include <linux/hash.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/gss_api.h>
#include <linux/spinlock.h>
#ifdef RPC_DEBUG
@ -122,6 +123,59 @@ rpcauth_unregister(const struct rpc_authops *ops)
}
EXPORT_SYMBOL_GPL(rpcauth_unregister);
/**
* rpcauth_list_flavors - discover registered flavors and pseudoflavors
* @array: array to fill in
* @size: size of "array"
*
* Returns the number of array items filled in, or a negative errno.
*
* The returned array is not sorted by any policy. Callers should not
* rely on the order of the items in the returned array.
*/
int
rpcauth_list_flavors(rpc_authflavor_t *array, int size)
{
rpc_authflavor_t flavor;
int result = 0;
spin_lock(&rpc_authflavor_lock);
for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
const struct rpc_authops *ops = auth_flavors[flavor];
rpc_authflavor_t pseudos[4];
int i, len;
if (result >= size) {
result = -ENOMEM;
break;
}
if (ops == NULL)
continue;
if (ops->list_pseudoflavors == NULL) {
array[result++] = ops->au_flavor;
continue;
}
len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
if (len < 0) {
result = len;
break;
}
for (i = 0; i < len; i++) {
if (result >= size) {
result = -ENOMEM;
break;
}
array[result++] = pseudos[i];
}
}
spin_unlock(&rpc_authflavor_lock);
dprintk("RPC: %s returns %d\n", __func__, result);
return result;
}
EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
struct rpc_auth *
rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
{