#ifndef _link_h_
#define _link_h_

#define SABM	401
#define UA	403
#define I	405
#define RR	406
#define	DISC	407
#define SIG_LEN 2
#define BO	2
#define SU	1
#define	SP	3
#define DEFAULT	10
#define FRAME_ERROR 13
#define FRAME_IS_FULL 34
#define FRAME_NOT_READY 123
#define	HEADER_LENGTH 22
#define TWO_BYTES 56
#define UPATH "./link_socket"
#define PPATH "./.phys_socket"

struct Frame;
int SystemError(void);
int GetFrameLength(Frame *frame);
int Default(void);
int DataRequest(void);
int ConnectRequest(void);
int ConnectIndication(void); 
int ConnectConfirm(void); 
int ConnectResponse(void); 
int DisconnectRequest(void); 
int DisconnectIndication(void);
int DisconnectResponse(void);
int DisconnectConfirm(void);
int AbortRequest(void);
int AbortIndication(void);
int Status(void);
int Abort(short who); 
int Checksum(int data_length);
int PutDataInFrame(char *data, short data_length, Frame *frame, short control);
int ClearFrame(Frame *frame);
int FillInFrame(char *frame, char data, char *charframe);
int CheckFrame(Frame *frame);
int CheckStartHeader(char *frame);
int CheckEndHeader(char *frame);
int CheckCC(Frame *frame);
int FixFrameData(Frame *frame);
int SendFrame(Frame *frame, int socket_id);
int DataIndication(void);
void MainLoop(void);

#endif