1 files changed, 74 insertions, 1 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index f5294047df77..ed2fdd210c0b 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -82,7 +82,7 @@ MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
 
 static u32
 pseudoflavor_to_flavor(u32 flavor) {
-        if (flavor >= RPC_AUTH_MAXFLAVOR)
+        if (flavor > RPC_AUTH_MAXFLAVOR)
                 return RPC_AUTH_GSS;
         return flavor;
 }
@@ -124,6 +124,79 @@ rpcauth_unregister(const struct rpc_authops *ops)
 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 
 /**
+ * rpcauth_get_pseudoflavor - check if security flavor is supported
+ * @flavor: a security flavor
+ * @info: a GSS mech OID, quality of protection, and service value
+ *
+ * Verifies that an appropriate kernel module is available or already loaded.
+ * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
+ * not supported locally.
+ */
+rpc_authflavor_t
+rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
+{
+        const struct rpc_authops *ops;
+        rpc_authflavor_t pseudoflavor;
+
+        ops = auth_flavors[flavor];
+        if (ops == NULL)
+                request_module("rpc-auth-%u", flavor);
+        spin_lock(&rpc_authflavor_lock);
+        ops = auth_flavors[flavor];
+        if (ops == NULL || !try_module_get(ops->owner)) {
+                spin_unlock(&rpc_authflavor_lock);
+                return RPC_AUTH_MAXFLAVOR;
+        }
+        spin_unlock(&rpc_authflavor_lock);
+
+        pseudoflavor = flavor;
+        if (ops->info2flavor != NULL)
+                pseudoflavor = ops->info2flavor(info);
+
+        module_put(ops->owner);
+        return pseudoflavor;
+}
+EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
+
+/**
+ * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
+ * @pseudoflavor: GSS pseudoflavor to match
+ * @info: rpcsec_gss_info structure to fill in
+ *
+ * Returns zero and fills in "info" if pseudoflavor matches a
+ * supported mechanism.
+ */
+int
+rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
+{
+        rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
+        const struct rpc_authops *ops;
+        int result;
+
+        if (flavor >= RPC_AUTH_MAXFLAVOR)
+                return -EINVAL;
+
+        ops = auth_flavors[flavor];
+        if (ops == NULL)
+                request_module("rpc-auth-%u", flavor);
+        spin_lock(&rpc_authflavor_lock);
+        ops = auth_flavors[flavor];
+        if (ops == NULL || !try_module_get(ops->owner)) {
+                spin_unlock(&rpc_authflavor_lock);
+                return -ENOENT;
+        }
+        spin_unlock(&rpc_authflavor_lock);
+
+        result = -ENOENT;
+        if (ops->flavor2info != NULL)
+                result = ops->flavor2info(pseudoflavor, info);
+
+        module_put(ops->owner);
+        return result;
+}
+EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
+
+/**
  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
  * @array: array to fill in
  * @size: size of "array"