NFS: use secinfo when crossing mountpoints

A submount may use different security than the parent
mount does.  We should figure out what sec flavor the
submount uses at mount time.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 8b4061049d7..6c844b01a1d 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -160,6 +160,28 @@ gss_mech_get_by_name(const char *name)
 
 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
 
+struct gss_api_mech *
+gss_mech_get_by_OID(struct xdr_netobj *obj)
+{
+        struct gss_api_mech     *pos, *gm = NULL;
+
+        spin_lock(&registered_mechs_lock);
+        list_for_each_entry(pos, &registered_mechs, gm_list) {
+                if (obj->len == pos->gm_oid.len) {
+                        if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
+                                if (try_module_get(pos->gm_owner))
+                                        gm = pos;
+                                break;
+                        }
+                }
+        }
+        spin_unlock(&registered_mechs_lock);
+        return gm;
+
+}
+
+EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
+
 static inline int
 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 {