typedef struct SilcPacketStruct *SilcPacket;

    The SilcPacket is returned by the packet engine in the SilcPacketReceive
    callback.  The application can parse the data payload from the
    SilcPacket.  Also packet type, flags, and sender and destination
    IDs are available.  The application must free the packet with the
    silc_packet_free function if it takes it in for processing.

    The `buffer' field contains the parsed packet payload and the start
    of the data area will point to the start of the packet payload.

    The list pointer `next' can be used by the application to put the
    packet context in a list during processing, if needed.

    typedef struct SilcPacketStruct {
      struct SilcPacketStruct *next;     /* List pointer, application may set */
      SilcPacketStream stream;           /* Packet stream this packet is from */
      SilcBufferStruct buffer;           /* Packet data payload */
      unsigned char *src_id;             /* Source ID */
      unsigned char *dst_id;             /* Destination ID */
      unsigned int src_id_len  : 6;      /* Source ID length */
      unsigned int src_id_type : 2;      /* Source ID type */
      unsigned int dst_id_len  : 6;      /* Destination ID length */
      unsigned int dst_id_type : 2;      /* Destination ID type */
      SilcPacketType type;               /* Packet type */
      SilcPacketFlags flags;             /* Packet flags */
    } *SilcPacket;