Esempio n. 1
0
File: rpl.c Progetto: hper/RIOT
void recv_rpl_dio(void)
{
    ipv6_buf = get_rpl_ipv6_buf();

    rpl_dio_buf = get_rpl_dio_buf();
    int len = DIO_BASE_LEN;

    rpl_instance_t *dio_inst = rpl_get_instance(rpl_dio_buf->rpl_instanceid);
    rpl_instance_t *my_inst = rpl_get_my_instance();

    if (dio_inst == NULL) {
        if (my_inst != NULL) {
            /* already part of a DODAG -> impossible to join other instance */
            return;
        }

        dio_inst = rpl_new_instance(rpl_dio_buf->rpl_instanceid);

        if (dio_inst == NULL) {
            return;
        }
    }
    else if (my_inst->id != dio_inst->id) {
        /* TODO: Add support support for several instances.  */

        /* At the moment, nodes can only join one instance, this is
        * the instance they join first.
        * Instances cannot be switched later on.  */

        DEBUG("Ignoring instance - we are %d and got %d\n", my_inst->id, dio_inst->id);
        return;
    }

    rpl_dodag_t dio_dodag;
    memset(&dio_dodag, 0, sizeof(dio_dodag));

    memcpy(&dio_dodag.dodag_id, &rpl_dio_buf->dodagid, sizeof(dio_dodag.dodag_id));
    dio_dodag.dtsn = rpl_dio_buf->dtsn;
    dio_dodag.mop = ((rpl_dio_buf->g_mop_prf >> RPL_MOP_SHIFT) & RPL_SHIFTED_MOP_MASK);
    dio_dodag.grounded = rpl_dio_buf->g_mop_prf >> RPL_GROUNDED_SHIFT;
    dio_dodag.prf = (rpl_dio_buf->g_mop_prf & RPL_PRF_MASK);
    dio_dodag.version = rpl_dio_buf->version_number;
    dio_dodag.instance = dio_inst;

    uint8_t has_dodag_conf_opt = 0;

    /* Parse until all options are consumed.
     * ipv6_buf->length contains the packet length minus ipv6 and
     * icmpv6 header, so only ICMPV6_HDR_LEN remains to be
     * subtracted.  */
    while (len < (ipv6_buf->length - ICMPV6_HDR_LEN)) {
        rpl_opt_buf = get_rpl_opt_buf(len);

        switch (rpl_opt_buf->type) {

            case (RPL_OPT_PAD1): {
                len += 1;
                break;
            }

            case (RPL_OPT_PADN): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case (RPL_OPT_DAG_METRIC_CONTAINER): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case (RPL_OPT_ROUTE_INFO): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case (RPL_OPT_DODAG_CONF): {
                has_dodag_conf_opt = 1;

                if (rpl_opt_buf->length != RPL_OPT_DODAG_CONF_LEN) {
                    /* error malformed */
                    return;
                }

                rpl_opt_dodag_conf_buf = get_rpl_opt_dodag_conf_buf(len);
                dio_dodag.dio_interval_doubling = rpl_opt_dodag_conf_buf->DIOIntDoubl;
                dio_dodag.dio_min = rpl_opt_dodag_conf_buf->DIOIntMin;
                dio_dodag.dio_redundancy = rpl_opt_dodag_conf_buf->DIORedun;
                dio_dodag.maxrankincrease =	rpl_opt_dodag_conf_buf->MaxRankIncrease;
                dio_dodag.minhoprankincrease = rpl_opt_dodag_conf_buf->MinHopRankIncrease;
                dio_dodag.default_lifetime = rpl_opt_dodag_conf_buf->default_lifetime;
                dio_dodag.lifetime_unit = rpl_opt_dodag_conf_buf->lifetime_unit;
                dio_dodag.of = (struct rpl_of_t *) rpl_get_of_for_ocp(rpl_opt_dodag_conf_buf->ocp);
                len += RPL_OPT_DODAG_CONF_LEN + 2;
                break;
            }

            case (RPL_OPT_PREFIX_INFO): {
                if (rpl_opt_buf->length != RPL_OPT_PREFIX_INFO_LEN) {
                    /* error malformed */
                    return;
                }

                len += RPL_OPT_PREFIX_INFO_LEN + 2;
                break;
            }

            default:
                DEBUG("[Error] Unsupported DIO option\n");
                return;
        }
    }

    /* handle packet content... */
    rpl_dodag_t *my_dodag = rpl_get_my_dodag();

    if (my_dodag == NULL) {
        if (!has_dodag_conf_opt) {
            DEBUG("send DIS\n");
            send_DIS(&ipv6_buf->srcaddr);
            return;
        }

        if (rpl_dio_buf->rank < ROOT_RANK) {
            DEBUG("DIO with Rank < ROOT_RANK\n");
            return;
        }

        if (dio_dodag.mop != RPL_DEFAULT_MOP) {
            DEBUG("Required MOP not supported\n");
            return;
        }

        if (dio_dodag.of == NULL) {
            DEBUG("Required objective function not supported\n");
            return;
        }

        if (rpl_dio_buf->rank != INFINITE_RANK) {
            char addr_str[IPV6_MAX_ADDR_STR_LEN];
            DEBUG("Will join DODAG\n");
            printf("%s", ipv6_addr_to_str(addr_str, &dio_dodag.dodag_id));
            rpl_join_dodag(&dio_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);
        }
        else {
            DEBUG("Cannot access DODAG because of DIO with infinite rank\n");
            return;
        }
    }

    if (rpl_equal_id(&my_dodag->dodag_id, &dio_dodag.dodag_id)) {
        /* "our" DODAG */
        if (RPL_COUNTER_GREATER_THAN(dio_dodag.version, my_dodag->version)) {
            if (my_dodag->my_rank == ROOT_RANK) {
                DEBUG("[Warning] Inconsistent Dodag Version\n");
                my_dodag->version = RPL_COUNTER_INCREMENT(dio_dodag.version);
                reset_trickletimer();
            }
            else {
                DEBUG("[Info] New Version of dodag %d\n", dio_dodag.version);
                rpl_global_repair(&dio_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);
            }

            return;
        }
        else if (RPL_COUNTER_GREATER_THAN(my_dodag->version, dio_dodag.version)) {
            /* ein Knoten hat noch eine kleinere Versionsnummer -> mehr DIOs senden */
            reset_trickletimer();
            return;
        }
    }

    /* version matches, DODAG matches */
    if (rpl_dio_buf->rank == INFINITE_RANK) {
        reset_trickletimer();
    }

    /* We are root, all done! */
    if (my_dodag->my_rank == ROOT_RANK) {
        if (rpl_dio_buf->rank != INFINITE_RANK) {
            trickle_increment_counter();
        }

        return;
    }

    /*********************  Parent Handling *********************/

    rpl_parent_t *parent;
    parent = rpl_find_parent(&ipv6_buf->srcaddr);

    if (parent == NULL) {
        /* add new parent candidate */
        parent = rpl_new_parent(my_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);

        if (parent == NULL) {
            return;
        }
    }
    else {
        /* DIO OK */
        trickle_increment_counter();
    }

    /* update parent rank */
    parent->rank = rpl_dio_buf->rank;
    rpl_parent_update(parent);

    if (rpl_equal_id(&parent->addr, &my_dodag->my_preferred_parent->addr) && (parent->dtsn != rpl_dio_buf->dtsn)) {
        delay_dao();
    }

    parent->dtsn = rpl_dio_buf->dtsn;

}
Esempio n. 2
0
void rpl_recv_DIO(void)
{
    ipv6_buf = get_rpl_ipv6_buf();

    rpl_dio_buf = get_rpl_dio_buf();
    DEBUGF("instance %04X ", rpl_dio_buf->rpl_instanceid);
    DEBUGF("rank %04X\n", byteorder_ntohs(rpl_dio_buf->rank));
    int len = DIO_BASE_LEN;

    rpl_instance_t *dio_inst = rpl_get_instance(rpl_dio_buf->rpl_instanceid);
    rpl_instance_t *my_inst = rpl_get_my_instance();

    if (dio_inst == NULL) {
        if (my_inst != NULL) {
            /* already part of a DODAG -> impossible to join other instance */
            DEBUGF("Not joining another DODAG!\n");
            return;
        }

        dio_inst = rpl_new_instance(rpl_dio_buf->rpl_instanceid);

        if (dio_inst == NULL) {
            DEBUGF("Failed to create a new RPL instance!\n");
            return;
        }
    }
    else if (my_inst == NULL) {
        DEBUGF("Not joined an instance yet\n");
    }
    else if (my_inst->id != dio_inst->id) {
        /* TODO: Add support support for several instances.  */

        /* At the moment, nodes can only join one instance, this is
        * the instance they join first.
        * Instances cannot be switched later on.  */

        DEBUGF("Ignoring instance - we are %d and got %d\n", my_inst->id, dio_inst->id);
        return;
    }

    rpl_dodag_t dio_dodag;
    memset(&dio_dodag, 0, sizeof(dio_dodag));

    memcpy(&dio_dodag.dodag_id, &rpl_dio_buf->dodagid, sizeof(dio_dodag.dodag_id));
    dio_dodag.dtsn = rpl_dio_buf->dtsn;
    dio_dodag.mop = ((rpl_dio_buf->g_mop_prf >> RPL_MOP_SHIFT) & RPL_SHIFTED_MOP_MASK);
    dio_dodag.grounded = rpl_dio_buf->g_mop_prf >> RPL_GROUNDED_SHIFT;
    dio_dodag.prf = (rpl_dio_buf->g_mop_prf & RPL_PRF_MASK);
    dio_dodag.version = rpl_dio_buf->version_number;
    dio_dodag.instance = dio_inst;

    uint8_t has_dodag_conf_opt = 0;

    /* Parse until all options are consumed.
     * ipv6_buf->length contains the packet length minus ipv6 and
     * icmpv6 header, so only ICMPV6_HDR_LEN remains to be
     * subtracted.  */
    while (len < (NTOHS(ipv6_buf->length) - ICMPV6_HDR_LEN)) {
        DEBUGF("parsing DIO options\n");
        rpl_opt_buf = get_rpl_opt_buf(len);

        switch (rpl_opt_buf->type) {

            case (RPL_OPT_PAD1): {
                len += 1;
                break;
            }

            case (RPL_OPT_PADN): {
                len += rpl_opt_buf->length;
                break;
            }

            case (RPL_OPT_DAG_METRIC_CONTAINER): {
                len += rpl_opt_buf->length;
                break;
            }

            case (RPL_OPT_ROUTE_INFO): {
                len += rpl_opt_buf->length;
                break;
            }

            case (RPL_OPT_DODAG_CONF): {
                has_dodag_conf_opt = 1;

                if (rpl_opt_buf->length != RPL_OPT_DODAG_CONF_LEN) {
                    DEBUGF("DODAG configuration is malformed.\n");
                    /* error malformed */
                    return;
                }

                rpl_opt_dodag_conf_buf = get_rpl_opt_dodag_conf_buf(len);
                dio_dodag.dio_interval_doubling = rpl_opt_dodag_conf_buf->DIOIntDoubl;
                dio_dodag.dio_min = rpl_opt_dodag_conf_buf->DIOIntMin;
                dio_dodag.dio_redundancy = rpl_opt_dodag_conf_buf->DIORedun;
                dio_dodag.maxrankincrease = byteorder_ntohs(rpl_opt_dodag_conf_buf->MaxRankIncrease);
                dio_dodag.minhoprankincrease = byteorder_ntohs(rpl_opt_dodag_conf_buf->MinHopRankIncrease);
                dio_dodag.default_lifetime = rpl_opt_dodag_conf_buf->default_lifetime;
                dio_dodag.lifetime_unit = byteorder_ntohs(rpl_opt_dodag_conf_buf->lifetime_unit);
                dio_dodag.of = (struct rpl_of_t *) rpl_get_of_for_ocp(byteorder_ntohs(rpl_opt_dodag_conf_buf->ocp));
                if (dio_dodag.of == NULL) {
                    DEBUGF("[Error] OCP from DIO is not supported! ocp: %x\n",
                    byteorder_ntohs(rpl_opt_dodag_conf_buf->ocp));
                    return;
                }

                len += RPL_OPT_DODAG_CONF_LEN_WITH_OPT_LEN;
                break;
            }

            case (RPL_OPT_PREFIX_INFO): {
                if (rpl_opt_buf->length != RPL_OPT_PREFIX_INFO_LEN) {
                    /* error malformed */
                    return;
                }

                rpl_opt_prefix_information_buf = get_rpl_opt_prefix_information_buf(len);

                /* autonomous address-configuration flag */
                if (rpl_opt_prefix_information_buf->flags & (1 << 6)) {
                    ipv6_addr_t tmp;
                    tmp = rpl_opt_prefix_information_buf->prefix;
                    if (!ipv6_addr_is_link_local(&tmp)) {
                        if (byteorder_ntohl(rpl_opt_prefix_information_buf->preferred_lifetime)
                                <= byteorder_ntohl(rpl_opt_prefix_information_buf->valid_lifetime)) {
                            ipv6_addr_set_by_eui64(&tmp, rpl_if_id, &tmp);
                            ipv6_net_if_add_addr(rpl_if_id, &tmp,
                                    NDP_ADDR_STATE_PREFERRED,
                                    byteorder_ntohl(rpl_opt_prefix_information_buf->valid_lifetime),
                                    byteorder_ntohl(rpl_opt_prefix_information_buf->preferred_lifetime),
                                    0);
                            dio_dodag.prefix = rpl_opt_prefix_information_buf->prefix;
                            dio_dodag.prefix_length = rpl_opt_prefix_information_buf->prefix_length;
                            dio_dodag.prefix_valid_lifetime =
                                byteorder_ntohl(rpl_opt_prefix_information_buf->valid_lifetime);
                            dio_dodag.prefix_preferred_lifetime =
                                byteorder_ntohl(rpl_opt_prefix_information_buf->preferred_lifetime);
                            dio_dodag.prefix_flags = rpl_opt_prefix_information_buf->flags;
                        }
                    }
                }

                len += RPL_OPT_PREFIX_INFO_LEN_WITH_OPT_LEN;
                break;
            }

            default:
                DEBUGF("[Error] Unsupported DIO option\n");
                return;
        }
    }

    /* handle packet content... */
    rpl_dodag_t *my_dodag = rpl_get_joined_dodag(dio_inst->id);

    if (my_dodag == NULL) {
        if (!has_dodag_conf_opt) {
            DEBUGF("send DIS\n");
            rpl_send_DIS(&ipv6_buf->srcaddr);
        }

        if (byteorder_ntohs(rpl_dio_buf->rank) < ROOT_RANK) {
            DEBUGF("DIO with Rank < ROOT_RANK\n");
        }

        if (dio_dodag.mop != RPL_DEFAULT_MOP) {
            DEBUGF("Required MOP not supported\n");
        }

        if (dio_dodag.of == NULL) {
            DEBUGF("Required objective function not supported\n");
        }

        if (byteorder_ntohs(rpl_dio_buf->rank) != INFINITE_RANK) {
            DEBUGF("Will join DODAG\n");
            rpl_join_dodag(&dio_dodag, &ipv6_buf->srcaddr, byteorder_ntohs(rpl_dio_buf->rank));
        }
        else {
            DEBUGF("Cannot access DODAG because of DIO with infinite rank\n");
        }

        return;
    }

    if (rpl_equal_id(&my_dodag->dodag_id, &dio_dodag.dodag_id)) {
        /* "our" DODAG */
        if (RPL_COUNTER_GREATER_THAN(dio_dodag.version, my_dodag->version)) {
            if (my_dodag->my_rank == ROOT_RANK) {
                DEBUGF("[Warning] Inconsistent Dodag Version\n");
                my_dodag->version = RPL_COUNTER_INCREMENT(dio_dodag.version);
                trickle_reset_timer(&my_dodag->trickle);
            }
            else {
                DEBUGF("my dodag has no preferred_parent yet - seems to be odd since I have a parent.\n");
                my_dodag->version = dio_dodag.version;
                rpl_global_repair(my_dodag, &ipv6_buf->srcaddr, byteorder_ntohs(rpl_dio_buf->rank));
            }

            return;
        }
        else if (RPL_COUNTER_GREATER_THAN(my_dodag->version, dio_dodag.version)) {
            /* lower version number detected -> send more DIOs */
            trickle_reset_timer(&my_dodag->trickle);
            return;
        }
    }

    /* version matches, DODAG matches */
    if (byteorder_ntohs(rpl_dio_buf->rank) == INFINITE_RANK) {
        trickle_reset_timer(&my_dodag->trickle);
    }

    /* We are root, all done!*/
    if (my_dodag->my_rank == ROOT_RANK) {
        if (byteorder_ntohs(rpl_dio_buf->rank) != INFINITE_RANK) {
            trickle_increment_counter(&my_dodag->trickle);
        }

        return;
    }

    /*********************  Parent Handling *********************/

    rpl_parent_t *parent;
    parent = rpl_find_parent(my_dodag, &ipv6_buf->srcaddr);

    if (parent == NULL) {
        /* add new parent candidate */
        parent = rpl_new_parent(my_dodag, &ipv6_buf->srcaddr, byteorder_ntohs(rpl_dio_buf->rank));

        if (parent == NULL) {
            return;
        }
    }
    else {
        /* DIO OK */
        trickle_increment_counter(&my_dodag->trickle);
    }

    /* update parent rank */
    parent->rank = byteorder_ntohs(rpl_dio_buf->rank);
    rpl_parent_update(my_dodag, parent);

    if (my_dodag->my_preferred_parent == NULL) {
        DEBUGF("My dodag has no preferred_parent yet - seems to be odd since I have a parent...\n");
    }
    else if (rpl_equal_id(&parent->addr, &my_dodag->my_preferred_parent->addr) &&
             (parent->dtsn != rpl_dio_buf->dtsn)) {
        rpl_delay_dao(my_dodag);
    }

    parent->dtsn = rpl_dio_buf->dtsn;

}
Esempio n. 3
0
void recv_rpl_dio(void)
{
    ipv6_buf = get_rpl_ipv6_buf();

    rpl_dio_buf = get_rpl_dio_buf();
    int len = DIO_BASE_LEN;

    rpl_instance_t *dio_inst = rpl_get_instance(rpl_dio_buf->rpl_instanceid);
    rpl_instance_t *my_inst = rpl_get_my_instance();

    if(dio_inst == NULL) {
        if(my_inst != NULL) {
            /* Dieser Knoten ist schon Teil eines DODAGS -> kein beitritt zu anderer Instanz moeglich */
            return;
        }

        dio_inst = rpl_new_instance(rpl_dio_buf->rpl_instanceid);

        if(dio_inst == NULL) {
            return;
        }
    }
    else if(my_inst->id != dio_inst->id) {
        printf("Andere Instanz, wir haben %d es kam aber %d\n", my_inst->id, dio_inst->id);
        /* DIO von fremder Instanz ignorieren, Knoten können Momentan nur
         * einer Instanz beitreten und das wird die Instanz sein, der sie als
         * erstes beitreten. Danach kann die Instanz nicht mehr gewechselt
         * werden Unterstützung für mehrere Instanzen könnte in Zukunft
         * implementiert werden */
        return;
    }

    rpl_dodag_t dio_dodag;
    memset(&dio_dodag, 0, sizeof(dio_dodag));

    memcpy(&dio_dodag.dodag_id, &rpl_dio_buf->dodagid, sizeof(dio_dodag.dodag_id));
    dio_dodag.dtsn = rpl_dio_buf->dtsn;
    dio_dodag.mop = ((rpl_dio_buf->g_mop_prf >> RPL_MOP_SHIFT) & RPL_SHIFTED_MOP_MASK);
    dio_dodag.grounded = rpl_dio_buf->g_mop_prf >> RPL_GROUNDED_SHIFT;
    dio_dodag.prf = (rpl_dio_buf->g_mop_prf & RPL_PRF_MASK);
    dio_dodag.version = rpl_dio_buf->version_number;
    dio_dodag.instance = dio_inst;

    uint8_t has_dodag_conf_opt = 0;
    /* So lange das Paket größer ist, als die DIO Größe + Größe der bisher
     * verarbeiteten Optionen, sind noch weitere Optionen zu bearbeiten */

    /* dabei müssen wir jedoch von der ipv6_buf->length die Größe des ICMP
     * Headers abziehen weil get_rpl_opt_buf die Paketlänge OHNE ipv6 und
     * icmpv6 header übergeben werden muss in ipv6_buf->length ist die
     * IPV6_HDR_LEN nicht enthalten, also muss nur noch die ICMPV6_HDR_LEN
     * abgezogen werden */

    while(len < (ipv6_buf->length - ICMPV6_HDR_LEN)) {
        rpl_opt_buf = get_rpl_opt_buf(len);

        switch(rpl_opt_buf->type) {

            case(RPL_OPT_PAD1): {
                len += 1;
                break;
            }

            case(RPL_OPT_PADN): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case(RPL_OPT_DAG_METRIC_CONTAINER): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case(RPL_OPT_ROUTE_INFO): {
                len += rpl_opt_buf->length + 2;
                break;
            }

            case(RPL_OPT_DODAG_CONF): {
                has_dodag_conf_opt = 1;

                if(rpl_opt_buf->length != RPL_OPT_DODAG_CONF_LEN) {
                    /* error malformed */
                    return;
                }

                rpl_opt_dodag_conf_buf = get_rpl_opt_dodag_conf_buf(len);
                dio_dodag.dio_interval_doubling = rpl_opt_dodag_conf_buf->DIOIntDoubl;
                dio_dodag.dio_min = rpl_opt_dodag_conf_buf->DIOIntMin;
                dio_dodag.dio_redundancy = rpl_opt_dodag_conf_buf->DIORedun;
                dio_dodag.maxrankincrease =	rpl_opt_dodag_conf_buf->MaxRankIncrease;
                dio_dodag.minhoprankincrease = rpl_opt_dodag_conf_buf->MinHopRankIncrease;
                dio_dodag.default_lifetime = rpl_opt_dodag_conf_buf->default_lifetime;
                dio_dodag.lifetime_unit = rpl_opt_dodag_conf_buf->lifetime_unit;
                dio_dodag.of = rpl_get_of_for_ocp(rpl_opt_dodag_conf_buf->ocp);
                len += RPL_OPT_DODAG_CONF_LEN + 2;
                break;
            }

            case(RPL_OPT_PREFIX_INFO): {
                if(rpl_opt_buf->length != RPL_OPT_PREFIX_INFO_LEN) {
                    /* error malformed */
                    return;
                }

                len += RPL_OPT_PREFIX_INFO_LEN + 2;
                break;
            }

            default:
                printf("[Error] Unsupported DIO option\n");
                return;
        }
    }

    /* handle packet content... */
    rpl_dodag_t *my_dodag = rpl_get_my_dodag();

    if(my_dodag == NULL) {
        if(!has_dodag_conf_opt) {
            puts("send DIS");
            send_DIS(&ipv6_buf->srcaddr);
            return;
        }

        if(rpl_dio_buf->rank < ROOT_RANK) {
            printf("DIO with Rank < ROOT_RANK\n");
            return;
        }

        if(dio_dodag.mop != RPL_DEFAULT_MOP) {
            printf("Required MOP not supported\n");
            return;
        }

        if(dio_dodag.of == NULL) {
            printf("Required objective function not supported\n");
            return;
        }

        if(rpl_dio_buf->rank != INFINITE_RANK) {
            puts("Will join DODAG\n");
            ipv6_print_addr(&dio_dodag.dodag_id);
            rpl_join_dodag(&dio_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);
        }
        else {
            printf("Cannot access DODAG because of DIO with infinite rank\n");
            return;
        }
    }

    if(rpl_equal_id(&my_dodag->dodag_id, &dio_dodag.dodag_id)) {
        /* Mein DODAG */
        if(RPL_COUNTER_GREATER_THAN(dio_dodag.version, my_dodag->version)) {
            if(my_dodag->my_rank == ROOT_RANK) {
                /* Jemand hat ein DIO mit einer höheren Version als der richtigen gesendet */
                /* Wir erhöhen diese Version noch einmal, und machen sie zur neuen */
                printf("[Warning] Inconsistent Dodag Version\n");
                my_dodag->version = RPL_COUNTER_INCREMENT(dio_dodag.version);
                reset_trickletimer();
            }
            else {
                printf("[Info] New Version of dodag %d\n", dio_dodag.version);
                rpl_global_repair(&dio_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);
            }

            return;
        }
        else if(RPL_COUNTER_GREATER_THAN(my_dodag->version, dio_dodag.version)) {
            /* ein Knoten hat noch eine kleinere Versionsnummer -> mehr DIOs senden */
            reset_trickletimer();
            return;
        }
    }

    /* Version stimmt, DODAG stimmt */
    if(rpl_dio_buf->rank == INFINITE_RANK) {
        reset_trickletimer();
    }

    /* Wenn wir root sind, ist nichts weiter zu tun */
    if(my_dodag->my_rank == ROOT_RANK) {
        if(rpl_dio_buf->rank != INFINITE_RANK) {
            trickle_increment_counter();
        }

        return;
    }

    /*  */
    /*  Parent Handling */
    /*  */

    /* Ist Knoten bereits Parent? */
    rpl_parent_t *parent;
    parent = rpl_find_parent(&ipv6_buf->srcaddr);

    if(parent == NULL) {
        /* neuen möglichen Elternknoten hinzufuegen */
        parent = rpl_new_parent(my_dodag, &ipv6_buf->srcaddr, rpl_dio_buf->rank);

        if(parent == NULL) {
            return;
        }
    }
    else {
        /* DIO ok */
        trickle_increment_counter();
    }

    /* update parent rank */
    parent->rank = rpl_dio_buf->rank;
    rpl_parent_update(parent);

    if(rpl_equal_id(&parent->addr, &my_dodag->my_preferred_parent->addr) && (parent->dtsn != rpl_dio_buf->dtsn)) {
        delay_dao();
    }

    parent->dtsn = rpl_dio_buf->dtsn;

}