MESH_PATH_SN_VALID
if (mpath->flags & MESH_PATH_SN_VALID)
(mpath->flags & MESH_PATH_SN_VALID)) {
have_sn = mpath->flags & MESH_PATH_SN_VALID;
mpath->flags |= MESH_PATH_SN_VALID;
if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
mpath->flags |= MESH_PATH_SN_VALID;
(!(mpath->flags & MESH_PATH_SN_VALID) ||
mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;