#define SILC_PACKET_LENGTH ...

    Returns true length of the packet. This is primarily used by the
    libary in packet parsing phase but the application may use it as
    well if needed.

    #define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
    do {                                                                     \
      SILC_GET16_MSB((__ret_truelen), (__packetdata));                       \
      (__ret_paddedlen) = (__ret_truelen) + (SilcUInt8)(__packetdata)[4];    \
    } while(0)