Method CheckPacketIntegrity

library/cpp/netliba/v12/udp_socket.cpp:192–218

    }

    bool TUdpSocket::CheckPacketIntegrity(const char* buf, const size_t size, const TSockAddrPair& addr) {
        // ignore empty or small packets
        if (size < UDP_LOW_LEVEL_HEADER_SIZE) {
            return false;
        }

        if (ReadVersion(buf) != UDP_NETLIBA_VERSION_V12) {
            fprintf(stderr, "NETLIBA::TUdpSocket: version mismatch\n");
            return false;
        }

        const size_t packetDataSize = ReadPacketDataSize(buf);
        if (packetDataSize + UDP_LOW_LEVEL_HEADER_SIZE > size) {
            fprintf(stderr, "NETLIBA::TUdpSocket: bad packet size in header\n");
            return false;
        }

        const ui64 expectedCrc = *(ui64*)buf;

        const ui64 crc = CalcChecksum(buf + UDP_CRC_SIZE, packetDataSize + (UDP_LOW_LEVEL_HEADER_SIZE - UDP_CRC_SIZE)) + PROTO_REV;
        if (!CrcMatches(expectedCrc, crc + PortCrc, addr.RemoteAddr)) {
            fprintf(stderr, "NETLIBA::TUdpSocket: udp packet crc failure %s, expected %" PRIu64 ", %" PRIu64 ", %u \n",
                    GetAddressAsString(GetUdpAddress(addr.RemoteAddr)).c_str(), expectedCrc, crc, PortCrc);
            return false;
        }
        return true;
    }

    ///////////////////////////////////////////////////////////////////////////////