nl_msg_put_genlmsghdr(&request, sock, 0, openflow_family, NLM_F_REQUEST,
DP_GENL_C_QUERY_DP, 1);
nl_msg_put_u32(&request, DP_GENL_A_DP_IDX, dp_idx);
retval = nl_sock_transact(sock, &request, &reply);
nl_msg_put_genlmsghdr(&request, sock, 0, openflow_family, NLM_F_REQUEST,
DP_GENL_C_QUERY_DP, 1);
nl_msg_put_u32(&request, DP_GENL_A_DP_IDX, dp_idx);
retval = nl_sock_transact(sock, &request, &reply);