ub_val_ctx_create
ub_val_ctx_delete
ub_val_ctx_config
ub_val_ctx_set_fwd
ub_val_ctx_resolvconf
ub_val_ctx_add_ta
ub_val_ctx_add_ta_file
ub_val_ctx_trustedkeys
ub_val_ctx_debuglevel
ub_val_ctx_async
ub_val_poll
ub_val_wait
ub_val_fd
ub_val_process
ub_val_resolve
ub_val_resolve_async
ub_val_cancel
ub_val_result_free
ub_val_strerror