Esempio n. 1
0
static void _receive(ng_pktsnip_t *pkt)
{
    kernel_pid_t iface = KERNEL_PID_UNDEF;
    ng_pktsnip_t *ipv6, *netif;
    ng_ipv6_hdr_t *hdr;

    LL_SEARCH_SCALAR(pkt, netif, type, NG_NETTYPE_NETIF);

    if (netif != NULL) {
        iface = ((ng_netif_hdr_t *)netif->data)->if_pid;
    }

    if ((pkt->next != NULL) && (pkt->next->type == NG_NETTYPE_IPV6) &&
        (pkt->next->size == sizeof(ng_ipv6_hdr_t))) {
        /* IP header was already marked. Take it. */
        ipv6 = pkt->next;

        if (!ng_ipv6_hdr_is(ipv6->data)) {
            DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
            ng_pktbuf_release(pkt);
            return;
        }
    }
    else {
        if (!ng_ipv6_hdr_is(pkt->data)) {
            DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
            ng_pktbuf_release(pkt);
            return;
        }

        /* seize ipv6 as a temporary variable */
        ipv6 = ng_pktbuf_start_write(pkt);

        if (ipv6 == NULL) {
            DEBUG("ipv6: unable to get write access to packet, drop it\n");
            ng_pktbuf_release(pkt);
            return;
        }

        pkt = ipv6;     /* reset pkt from temporary variable */

        ipv6 = ng_pktbuf_add(pkt, pkt->data, sizeof(ng_ipv6_hdr_t),
                             NG_NETTYPE_IPV6);

        if (ipv6 == NULL) {
            DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
            ng_pktbuf_release(pkt);
            return;
        }
    }

    /* extract header */
    hdr = (ng_ipv6_hdr_t *)ipv6->data;

    DEBUG("ipv6: Received (src = %s, ",
          ng_ipv6_addr_to_str(addr_str, &(hdr->src), sizeof(addr_str)));
    DEBUG("dst = %s, next header = %" PRIu8 ", length = %" PRIu16 ")\n",
          ng_ipv6_addr_to_str(addr_str, &(hdr->dst), sizeof(addr_str)),
          hdr->nh, byteorder_ntohs(hdr->len));

    if (_pkt_not_for_me(&iface, hdr)) { /* if packet is not for me */
        DEBUG("ipv6: packet destination not this host\n");

#ifdef MODULE_NG_IPV6_ROUTER    /* only routers redirect */
        /* redirect to next hop */
        DEBUG("ipv6: decrement hop limit to %" PRIu8 "\n", hdr->hl - 1);

        /* TODO: check if receiving interface is router */
        if (--(hdr->hl) > 0) {  /* drop packets that *reach* Hop Limit 0 */
            ng_pktsnip_t *tmp = pkt;

            DEBUG("ipv6: forward packet to next hop\n");

            /* pkt might not be writable yet, if header was given above */
            pkt = ng_pktbuf_start_write(tmp);
            ipv6 = ng_pktbuf_start_write(ipv6);

            if ((ipv6 == NULL) || (pkt == NULL)) {
                DEBUG("ipv6: unable to get write access to packet: dropping it\n");
                ng_pktbuf_release(tmp);
                return;
            }

            ng_pktbuf_release(ipv6->next);  /* remove headers around IPV6 */
            ipv6->next = pkt;           /* reorder for sending */
            pkt->next = NULL;
            _send(ipv6, false);
        }
        else {
            DEBUG("ipv6: hop limit reached 0: drop packet\n");
            ng_pktbuf_release(pkt);
            return;
        }

#else  /* MODULE_NG_IPV6_ROUTER */
        DEBUG("ipv6: dropping packet\n");
        /* non rounting hosts just drop the packet */
        ng_pktbuf_release(pkt);
        return;
#endif /* MODULE_NG_IPV6_ROUTER */
    }

    /* IPv6 internal demuxing (ICMPv6, Extension headers etc.) */
    ng_ipv6_demux(iface, pkt, hdr->nh);
}
Esempio n. 2
0
static void _receive(gnrc_pktsnip_t *pkt)
{
    kernel_pid_t iface = KERNEL_PID_UNDEF;
    gnrc_pktsnip_t *ipv6, *netif, *first_ext;
    ipv6_hdr_t *hdr;

    assert(pkt != NULL);

    netif = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_NETIF);

    if (netif != NULL) {
        iface = ((gnrc_netif_hdr_t *)netif->data)->if_pid;

#ifdef MODULE_NETSTATS_IPV6
        assert(iface);
        netstats_t *stats = gnrc_ipv6_netif_get_stats(iface);
        stats->rx_count++;
        stats->rx_bytes += (gnrc_pkt_len(pkt) - netif->size);
#endif
    }

    first_ext = pkt;

    for (ipv6 = pkt; ipv6 != NULL; ipv6 = ipv6->next) { /* find IPv6 header if already marked */
        if ((ipv6->type == GNRC_NETTYPE_IPV6) && (ipv6->size == sizeof(ipv6_hdr_t)) &&
            (ipv6_hdr_is(ipv6->data))) {
            break;
        }

        first_ext = ipv6;
    }

    if (ipv6 == NULL) {
        if (!ipv6_hdr_is(pkt->data)) {
            DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
#ifdef MODULE_GNRC_IPV6_WHITELIST
        if (!gnrc_ipv6_whitelisted(&((ipv6_hdr_t *)(pkt->data))->src)) {
            DEBUG("ipv6: Source address not whitelisted, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
#endif
#ifdef MODULE_GNRC_IPV6_BLACKLIST
        if (gnrc_ipv6_blacklisted(&((ipv6_hdr_t *)(pkt->data))->src)) {
            DEBUG("ipv6: Source address blacklisted, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
#endif
        /* seize ipv6 as a temporary variable */
        ipv6 = gnrc_pktbuf_start_write(pkt);

        if (ipv6 == NULL) {
            DEBUG("ipv6: unable to get write access to packet, drop it\n");
            gnrc_pktbuf_release(pkt);
            return;
        }

        pkt = ipv6;     /* reset pkt from temporary variable */

        ipv6 = gnrc_pktbuf_mark(pkt, sizeof(ipv6_hdr_t), GNRC_NETTYPE_IPV6);

        first_ext = pkt;
        pkt->type = GNRC_NETTYPE_UNDEF; /* snip is no longer IPv6 */

        if (ipv6 == NULL) {
            DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
    }
#ifdef MODULE_GNRC_IPV6_WHITELIST
    else if (!gnrc_ipv6_whitelisted(&((ipv6_hdr_t *)(ipv6->data))->src)) {
        /* if ipv6 header already marked*/
        DEBUG("ipv6: Source address not whitelisted, dropping packet\n");
        gnrc_pktbuf_release(pkt);
        return;
    }
#endif
#ifdef MODULE_GNRC_IPV6_BLACKLIST
    else if (gnrc_ipv6_blacklisted(&((ipv6_hdr_t *)(ipv6->data))->src)) {
        /* if ipv6 header already marked*/
        DEBUG("ipv6: Source address blacklisted, dropping packet\n");
        gnrc_pktbuf_release(pkt);
        return;
    }
#endif

    /* extract header */
    hdr = (ipv6_hdr_t *)ipv6->data;

    /* if available, remove any padding that was added by lower layers
     * to fulfill their minimum size requirements (e.g. ethernet) */
    if (byteorder_ntohs(hdr->len) < pkt->size) {
        gnrc_pktbuf_realloc_data(pkt, byteorder_ntohs(hdr->len));
    }
    else if (byteorder_ntohs(hdr->len) >
             (gnrc_pkt_len_upto(pkt, GNRC_NETTYPE_IPV6) - sizeof(ipv6_hdr_t))) {
        DEBUG("ipv6: invalid payload length: %d, actual: %d, dropping packet\n",
              (int) byteorder_ntohs(hdr->len),
              (int) (gnrc_pkt_len_upto(pkt, GNRC_NETTYPE_IPV6) - sizeof(ipv6_hdr_t)));
        gnrc_pktbuf_release(pkt);
        return;
    }

    DEBUG("ipv6: Received (src = %s, ",
          ipv6_addr_to_str(addr_str, &(hdr->src), sizeof(addr_str)));
    DEBUG("dst = %s, next header = %u, length = %" PRIu16 ")\n",
          ipv6_addr_to_str(addr_str, &(hdr->dst), sizeof(addr_str)),
          hdr->nh, byteorder_ntohs(hdr->len));

    if (_pkt_not_for_me(&iface, hdr)) { /* if packet is not for me */
        DEBUG("ipv6: packet destination not this host\n");

#ifdef MODULE_GNRC_IPV6_ROUTER    /* only routers redirect */
        /* redirect to next hop */
        DEBUG("ipv6: decrement hop limit to %u\n", (uint8_t) (hdr->hl - 1));

        /* RFC 4291, section 2.5.6 states: "Routers must not forward any
         * packets with Link-Local source or destination addresses to other
         * links."
         */
        if ((ipv6_addr_is_link_local(&(hdr->src))) || (ipv6_addr_is_link_local(&(hdr->dst)))) {
            DEBUG("ipv6: do not forward packets with link-local source or"
                  " destination address\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
        /* TODO: check if receiving interface is router */
        else if (--(hdr->hl) > 0) {  /* drop packets that *reach* Hop Limit 0 */
            gnrc_pktsnip_t *reversed_pkt = NULL, *ptr = pkt;

            DEBUG("ipv6: forward packet to next hop\n");

            /* pkt might not be writable yet, if header was given above */
            ipv6 = gnrc_pktbuf_start_write(ipv6);
            if (ipv6 == NULL) {
                DEBUG("ipv6: unable to get write access to packet: dropping it\n");
                gnrc_pktbuf_release(pkt);
                return;
            }

            /* remove L2 headers around IPV6 */
            netif = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_NETIF);
            if (netif != NULL) {
                gnrc_pktbuf_remove_snip(pkt, netif);
            }

            /* reverse packet snip list order */
            while (ptr != NULL) {
                gnrc_pktsnip_t *next;
                ptr = gnrc_pktbuf_start_write(ptr);     /* duplicate if not already done */
                if (ptr == NULL) {
                    DEBUG("ipv6: unable to get write access to packet: dropping it\n");
                    gnrc_pktbuf_release(reversed_pkt);
                    gnrc_pktbuf_release(pkt);
                    return;
                }
                next = ptr->next;
                ptr->next = reversed_pkt;
                reversed_pkt = ptr;
                ptr = next;
            }
            _send(reversed_pkt, false);
            return;
        }
        else {
            DEBUG("ipv6: hop limit reached 0: drop packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }

#else  /* MODULE_GNRC_IPV6_ROUTER */
        DEBUG("ipv6: dropping packet\n");
        /* non rounting hosts just drop the packet */
        gnrc_pktbuf_release(pkt);
        return;
#endif /* MODULE_GNRC_IPV6_ROUTER */
    }

    /* IPv6 internal demuxing (ICMPv6, Extension headers etc.) */
    gnrc_ipv6_demux(iface, first_ext, pkt, hdr->nh);
}
Esempio n. 3
0
static void _receive(gnrc_pktsnip_t *pkt)
{
    kernel_pid_t iface = KERNEL_PID_UNDEF;
    gnrc_pktsnip_t *ipv6, *netif;
    ipv6_hdr_t *hdr;

    assert(pkt != NULL);

    LL_SEARCH_SCALAR(pkt, netif, type, GNRC_NETTYPE_NETIF);

    if (netif != NULL) {
        iface = ((gnrc_netif_hdr_t *)netif->data)->if_pid;
    }

    if ((pkt->next != NULL) && (pkt->next->type == GNRC_NETTYPE_IPV6) &&
        (pkt->next->size == sizeof(ipv6_hdr_t))) {
        /* IP header was already marked. Take it. */
        ipv6 = pkt->next;

        if (!ipv6_hdr_is(ipv6->data)) {
            DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
    }
    else {
        if (!ipv6_hdr_is(pkt->data)) {
            DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }

        /* seize ipv6 as a temporary variable */
        ipv6 = gnrc_pktbuf_start_write(pkt);

        if (ipv6 == NULL) {
            DEBUG("ipv6: unable to get write access to packet, drop it\n");
            gnrc_pktbuf_release(pkt);
            return;
        }

        pkt = ipv6;     /* reset pkt from temporary variable */

        ipv6 = gnrc_pktbuf_mark(pkt, sizeof(ipv6_hdr_t), GNRC_NETTYPE_IPV6);

        if (ipv6 == NULL) {
            DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
    }

    /* extract header */
    hdr = (ipv6_hdr_t *)ipv6->data;

    /* if available, remove any padding that was added by lower layers
     * to fulfill their minimum size requirements (e.g. ethernet) */
    if (byteorder_ntohs(hdr->len) < pkt->size) {
        gnrc_pktbuf_realloc_data(pkt, byteorder_ntohs(hdr->len));
    }

    DEBUG("ipv6: Received (src = %s, ",
          ipv6_addr_to_str(addr_str, &(hdr->src), sizeof(addr_str)));
    DEBUG("dst = %s, next header = %" PRIu8 ", length = %" PRIu16 ")\n",
          ipv6_addr_to_str(addr_str, &(hdr->dst), sizeof(addr_str)),
          hdr->nh, byteorder_ntohs(hdr->len));

    if (_pkt_not_for_me(&iface, hdr)) { /* if packet is not for me */
        DEBUG("ipv6: packet destination not this host\n");

#ifdef MODULE_GNRC_IPV6_ROUTER    /* only routers redirect */
        /* redirect to next hop */
        DEBUG("ipv6: decrement hop limit to %" PRIu8 "\n", hdr->hl - 1);

        /* RFC 4291, section 2.5.6 states: "Routers must not forward any
         * packets with Link-Local source or destination addresses to other
         * links."
         */
        if ((ipv6_addr_is_link_local(&(hdr->src))) || (ipv6_addr_is_link_local(&(hdr->dst)))) {
            DEBUG("ipv6: do not forward packets with link-local source or"\
                  " destination address\n");
            gnrc_pktbuf_release(pkt);
            return;
        }
        /* TODO: check if receiving interface is router */
        else if (--(hdr->hl) > 0) {  /* drop packets that *reach* Hop Limit 0 */
            gnrc_pktsnip_t *tmp = pkt;

            DEBUG("ipv6: forward packet to next hop\n");

            /* pkt might not be writable yet, if header was given above */
            pkt = gnrc_pktbuf_start_write(tmp);
            ipv6 = gnrc_pktbuf_start_write(ipv6);

            if ((ipv6 == NULL) || (pkt == NULL)) {
                DEBUG("ipv6: unable to get write access to packet: dropping it\n");
                gnrc_pktbuf_release(tmp);
                return;
            }

            gnrc_pktbuf_release(ipv6->next);    /* remove headers around IPV6 */
            ipv6->next = pkt;                   /* reorder for sending */
            pkt->next = NULL;
            _send(ipv6, false);
            return;
        }
        else {
            DEBUG("ipv6: hop limit reached 0: drop packet\n");
            gnrc_pktbuf_release(pkt);
            return;
        }

#else  /* MODULE_GNRC_IPV6_ROUTER */
        DEBUG("ipv6: dropping packet\n");
        /* non rounting hosts just drop the packet */
        gnrc_pktbuf_release(pkt);
        return;
#endif /* MODULE_GNRC_IPV6_ROUTER */
    }

    /* IPv6 internal demuxing (ICMPv6, Extension headers etc.) */
    gnrc_ipv6_demux(iface, pkt, hdr->nh);
}