Method decodeType_Generic

Server/src/bgp/ExtCommunity.cpp:465–567

* Decode Generic subtypes * * \details * Converts to human readable form. * * \param [in] ec_hdr Reference to the extended community header * \param [in] isGlobal4Bytes True if the global admin field is 4 bytes, false if 2 * \param [in] isGlobalIPv4 True if the global admin field is an IPv4 address, false if not * * \return Deco

     * \return  Decoded string value
     */
    std::string ExtCommunity::decodeType_Generic(const extcomm_hdr &ec_hdr, bool isGlobal4Bytes, bool isGlobalIPv4) {
        std::stringstream   val_ss;
        uint16_t            val_16b;
        uint32_t            val_32b;
        char                ipv4_char[16] = {0};

        /*
         * Decode values based on bit size
         */
        if (isGlobal4Bytes) {
            // Four-byte global field
            memcpy(&val_32b, ec_hdr.value, 4);
            memcpy(&val_16b, ec_hdr.value + 4, 2);

            bgp::SWAP_BYTES(&val_16b);

            if (isGlobalIPv4) {
                inet_ntop(AF_INET, &val_32b, ipv4_char, sizeof(ipv4_char));
            } else
                bgp::SWAP_BYTES(&val_32b);

        } else {
            // Two-byte global field
            memcpy(&val_16b, ec_hdr.value, 2);
            memcpy(&val_32b, ec_hdr.value + 2, 4);

            // Chagne to host order
            bgp::SWAP_BYTES(&val_16b);
            bgp::SWAP_BYTES(&val_32b);
        }

        switch (ec_hdr.low_type) {
            case EXT_GENERIC_OSPF_ROUTE_TYPE :  // deprecated
            case EXT_GENERIC_OSPF_ROUTER_ID :   // deprecated
            case EXT_GENERIC_OSPF_DOM_ID :      // deprecated
                LOG_INFO("%s: Ignoring deprecated extended community %d/%d", peer_addr.c_str(),
                        ec_hdr.high_type, ec_hdr.low_type);
                break;

            case EXT_GENERIC_LAYER2_INFO : {    // rfc4761
                u_char encap_type    = ec_hdr.value[0];
                u_char ctrl_flags   = ec_hdr.value[1];
                memcpy(&val_16b, ec_hdr.value + 2, 2);          // Layer 2 MTU
                bgp::SWAP_BYTES(&val_16b);

                val_ss << "l2info=";

                switch (encap_type) {
                    case 19 : // VPLS
                        val_ss << "vpls:";
                        break;

                    default:
                        val_ss << (int) encap_type << ":";
                        break;
                }

                val_ss << ctrl_flags << ":mtu:" << val_16b;