/*
**     This product contains:
**              "Restricted Materials of IBM"
**              (c) Copyright IBM Corp. 1987
**              All Rights Reserved
**              Licensed Materials-Property of IBM
**
**     See Copyright Instructions, G120-2083
**
*/

/*  Copyright 1984 by the Massachusetts Institute of Technology  */
/*  See permission and disclaimer notice in file "notice.h"  */
#include	<notice.h>
/* (c) 1986 Copyright IBM Corp.; See file <ibm-note.h> for permissions */

/* TFTP header file contains structures of TFTP packet headers and such. */

/* read or write request packet */
struct tfreq {
	unsigned	tf_op;		/* would be 1 (read) or 2 (write) */
	char		tf_name[20];	};

/* data packet */
struct tfdata {
	unsigned	tf_op;		/* would be 3 */
	unsigned	tf_block;
	char		tf_data[512];	};

/* structure of an ack packet */
struct	tfack {
	unsigned	tf_op;		/* would be 4 */
	unsigned	tf_block;	};

/* error packet */
struct tferr {
	unsigned	tf_op;		/* would be 5 */
	unsigned 	tf_code;
	char		tf_err[1]; };

/* TFTP opcodes */
#define	RRQ	1		/* read  request */
#define	WRQ	2		/* write request */
#define	DATA	3		/* data packet */
#define	ACK	4		/* acknowledgement packet */
#define	ERROR	5		/* error packet */

/* TFTP error codes */
#define	ERRTXT		0	/* see the enclosed text */
#define	FNOTFOUND	1	/* file not found */
#define	ACCESS		2	/* access violation */
#define	DISKFULL	3	/* don't even ask. */
#define	ILLTFTP		4	/* illegal TFTP operation */
#define	BADTID		5	/* unkown transfer ID */
#define	FEXISTS		6	/* file already exists */
#define	NOUSER		7	/* no such user */

/* TFTP states */
#define	DATAWAIT	1
#define	ACKWAIT		2
#define	DEAD		3
#define	TIMEOUT		4
#define	RCVERR		5
#define	RCVACK		6
#define	RCVDATA		7
#define	RCVLASTDATA	8
#define	TERMINATED	9

#define	TFTPSOCK	69	/* TFTP's well known port */
#define	TFTPTRIES	20	/* # of retries on packet transmission */
#define	REQTRIES	4	/* # of retries on initial request */
#define	REQLEN		512	/* .. */
#define	NORMLEN		512	/* normal length of received packet */

#define	tftp_head(p)	udp_data(udp_head(in_head((p))))
#define	tfkill(cn)	{tm_clear(cn->tf_tm); (cn)->tf_state=DEAD; tk_wake((cn)->tf_task);}
#define	tftp_data(p)	((struct tfdata *)tftp_head((p)))->tf_data

/* The TFTP connection structure. Contains connection info, and data for
	timeout calculations. */

struct tfconn {
	UDPCONN		tf_udp;			/* udp connection for this transfer */
	FILE		*tf_fd;			/* file descriptor for xfer */
	PACKET		tf_outp;		/* last sent packet */
	char		*tf_fbufp;		/* file buffer pointer */
	unsigned	tf_buff_bytes;	/* number of bytes for disk buffer */
	unsigned	tf_bytes_used;	/* disk buffer usage */
	unsigned	tf_lastlen;		/* length of last sent pkt */
	unsigned	tf_expected;	/* most recently processed block */
	unsigned	tf_fport;		/* foreign port */
	task		*tf_task;		/* main task for tftp connection */
	timer		*tf_tm;			/* our timer */
	unsigned	tf_state;		/* state of connection */
	unsigned	tf_tries;		/* # of retries already done */
	unsigned	tf_mode;		/* mode = OCTET, [net]ASCII, ... */
	unsigned	tf_looks_bad;	/* flag if ascii data looks fishy */
	unsigned	tf_dir;			/* direction of the transfer */
	long		tf_size;		/* # of bytes transferred */
	unsigned	tf_rcv;			/* # of packets received */
	unsigned	tf_snt;			/* # of packets sent */
	unsigned	tf_ous;			/* # of out of sequence packets */
	unsigned	tf_tmo;			/* # of timeouts */
	unsigned	tf_rsnd;		/* # of resends */
	long		tf_trt;			/* round trip time */
	long		tf_rt;			/* current timeout */
	int		tf_NR;				/* number rexmissions of this pkt */
	int		tf_NR_last;			/* "	"	" of prev pkt */
	int		tf_K;				/* tuning constant */
	long		tf_sent;		/* time that pkt was sent */
	int		tf_ctrlz;			/* append a eof mark (^Z) after writing file */
};

/*  Constants for round trip time estimation and retry timeout.
    All calculation is done in clock ticks (at a rate of 18/second) but
    only the initial estimate and the upper limit are specimn) is called to set cursor position
;
;*****************************************************************************
        PUBLIC _setcur
 
_TEXT   SEGMENT
 
_setcur:
        push    bp
        mov     bp,sp
        mov     dh,4[bp]                ;dh= row, dl= column
        mov     dl,6[bp]                ;dh= row, dl= column
        mov     bh,0                    ;ensure page 0
        mov     ah,2                    ;code for set cursor
        int     10H                     ;BIOS video i/o code
        pop     bp                      ;restore bp
        ret
 
;*****************************************************************************
;
;       wrbuf(->buffer,start_position,num_chars,
;             attribute-position, ->attr_b