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>
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 727e506..b5c067b 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -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 @@
}
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)
{
