3 files changed, 69 insertions, 4 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 727e506cacda..b5c067bccc45 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 @@ 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)
 {
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index d3ad81f8da5b..34c522021004 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1619,6 +1619,7 @@ static const struct rpc_authops authgss_ops = {
 	.crcreate	= gss_create_cred,
 	.pipes_create	= gss_pipes_dentries_create,
 	.pipes_destroy	= gss_pipes_dentries_destroy,
+	.list_pseudoflavors = gss_mech_list_pseudoflavors,
 };
 
 static const struct rpc_credops gss_credops = {
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 782bfe1b6465..6ac5dfcd2928 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -239,14 +239,26 @@ gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 
 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
 
-int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
+/**
+ * gss_mech_list_pseudoflavors - Discover registered GSS 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 gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 {
 	struct gss_api_mech *pos = NULL;
 	int j, i = 0;
 
 	spin_lock(&registered_mechs_lock);
 	list_for_each_entry(pos, &registered_mechs, gm_list) {
-		for (j=0; j < pos->gm_pf_num; j++) {
+		for (j = 0; j < pos->gm_pf_num; j++) {
+			if (i >= size)
+				return -ENOMEM;
 			array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 		}
 	}
@@ -254,8 +266,6 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
 	return i;
 }
 
-EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
-
 u32
 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
 {