Feature request: Multicast message resend to improve reliability about mbed-client-c HOT 3 CLOSED

/**
 * \fn int8_t sn_nsdl_set_non_confirmable_resent_parameters(bool enable_resent)
 *
 * \brief  If re-transmissions are enabled (see also sn_nsdl_set_retransmission_parameters),
 *         this function enables/disables a resent of a non confirmable message. This
 *         improves the transmission reliability by duplicating the message (including
 *         header). The CoAP protocol at receiver side will recognize the duplications
 *         and discards the redundant messages.
 *
 * \param bool enable_resent when set to resent non confirmable messages
 * \return  0 = success, -1 = failure
 */
extern int8_t sn_nsdl_set_non_confirmable_resent_parameters(struct nsdl_s *handle, bool enable_resent);

/**
 * \fn int8_t sn_coap_protocol_set_non_confirmable_resent_parameters(bool enable_resent)
 *
 * \brief  If re-transmissions are enabled (see also sn_nsdl_set_retransmission_parameters),
 *         this function enables/disables a resent of a non confirmable message. This
 *         improves the transmission reliability by duplicating the message (including
 *         header). The CoAP protocol at receiver side will recognize the duplications
 *         and discards the redundant messages.
 *
 * \param bool enable_resent when set to resent non confirmable messages
 * \return  0 = success, -1 = failure
 */
extern int8_t sn_coap_protocol_set_non_confirmable_resent_parameters(struct coap_s *handle,
        bool enable_resent);

extern int8_t sn_nsdl_set_non_confirmable_resent_parameters(struct nsdl_s *handle,
    bool enable_resent)
{
    if (handle == NULL) {
        return SN_NSDL_FAILURE;
    }
    return sn_coap_protocol_set_non_confirmable_resent_parameters(handle->grs->coap,
                                                                  enable_resent);
}

int8_t sn_coap_protocol_set_non_confirmable_resent_parameters(struct coap_s *handle,
        bool enable_resent)
{
#if ENABLE_RESENDINGS
    if (handle == NULL) {
        return -1;
    }

    handle->resent_non_confirmable = enable_resent;

    return 0;

#endif
    return -1;
}

#if ENABLE_RESENDINGS /* If Message resending is not used at all, this part of code will not be compiled */

    /* Check if built Message type was confirmable, only these messages are resent when not acknowledged.
       NON confirmable messages can be queued when sn_nsdl_set_retransmission_parameters() explicit requests to perform a scheduled resent */
    if( (src_coap_msg_ptr->msg_type == COAP_MSG_TYPE_CONFIRMABLE) ||
        ((src_coap_msg_ptr->msg_type == COAP_MSG_TYPE_NON_CONFIRMABLE) && (handle->resent_non_confirmable)) ) {
        /* Store message to Linked list for resending purposes */
        sn_coap_protocol_linked_list_send_msg_store(handle, dst_addr_ptr, byte_count_built, dst_packet_data_ptr,
                handle->system_time + (uint32_t)(handle->sn_coap_resending_intervall * RESPONSE_RANDOM_FACTOR),
                param, src_coap_msg_ptr->uri_path_ptr, src_coap_msg_ptr->uri_path_len);
    }

#endif /* ENABLE_RESENDINGS */