char *protv = "C-Kermit Protocol Module 4C(026), 12 Jun 85"; /* -*-C-*- */

/* C K C P R O  -- C-Kermit Protocol Module, in Wart preprocessor notation. */
/*
 Author: Frank da Cruz (SY.FDC@CU20B),
 Columbia University Center for Computing Activities, January 1985.
 Copyright (C) 1985, Trustees of Columbia University in the City of New York.
 Permission is granted to any individual or institution to use, copy, or
 redistribute this software so long as it is not sold for profit, provided this
 copyright notice is retained. 
*/
#include "ckcdeb.h"
#include "ckcker.h"
/*
 Note -- This file may also be preprocessed by the Unix Lex program, but 
 you must indent the above #include statement before using Lex, and then
 restore it to the left margin in the resulting C program before compilation.
 Also, the invocation of the "wart()" function below must be replaced by an
 invocation  of the "yylex()" function.  It might also be necessary to remove
 comments in the %%...%% section.
*/

/* State definitions for Wart (or Lex) */
%states ipkt rfile rdata ssinit ssdata sseof sseot serve generic get rgen

/* External C-Kermit variable declarations */
  extern char sstate, *versio, *srvtxt, *cmarg, *cmarg2;
  extern char data[], filnam[], srvcmd[], ttname[], *srvptr;
  extern int pktnum, timint, nfils, image, hcflg, xflg, speed, flow, mdmtyp;
  extern int prvpkt, cxseen, czseen, server, local, displa, bctu, bctr, quiet;
  extern int putsrv(), puttrm(), putfil(), errpkt();
  extern char *DIRCMD, *DELCMD, *TYPCMD, *SPACMD, *SPACM2, *WHOCMD;

/* Local variables */
  static char vstate = 0;  		/* Saved State   */
  static char vcmd = 0;    		/* Saved Command */
  static int x;				/* General-purpose integer */

/* Macros - Note, BEGIN is predefined by Wart (and Lex) */
#define SERVE  tinit(); BEGIN serve
#define RESUME if (server) { SERVE; } else return

%%
/* Protocol entry points, one for each start state (sstate) */

s { tinit();	    	    	    	/* Do Send command */
    if (sinit()) BEGIN ssinit;
       else RESUME; }

v { tinit(); sleep(1); nack(); BEGIN get; } 	    	    	/* Receive */
r { tinit(); vstate = get;  vcmd = 0;   sipkt(); BEGIN ipkt; }	/* Get */
c { tinit(); vstate = rgen; vcmd = 'C'; sipkt(); BEGIN ipkt; }	/* Host */
g { tinit(); vstate = rgen; vcmd = 'G'; sipkt(); BEGIN ipkt; }	/* Generic */

x { sleep(1); SERVE; }	    	    	/* Be a Server */

a { errpkt("User cancelled transaction"); /* Tell other side what's going on */
    x = quiet; quiet = 1; 		/* Close files silently */
    clsif(); clsof(); 
    quiet = x; return(0); }		/* Return from protocol. */

/* Dynamic states: <current-states>input-character { action } */

<rgen,get,serve>S { rinit(data); bctu = bctr; BEGIN rfile; } /* Send-Init */

<ipkt>Y  { spar(data);			/* Get ack for I-packet */
    	   if (vcmd) { scmd(vcmd,cmarg); vcmd = 0; }
    	   if (vstate == get) srinit();
	   BEGIN vstate; }

<ipkt>E  { if (vcmd) scmd(vcmd,cmarg);	/* Get E for I-packet (ignore) */
    	   vcmd = 0; if (vstate == get) srinit();
	   BEGIN vstate; }

<serve>R { srvptr = srvcmd; decode(data,putsrv); /* Get Receive-Init */
	   cmarg = srvcmd;  nfils = -1;
    	   if (sinit()) BEGIN ssinit; else { SERVE; } }

<serve>I { spar(data); rpar(data); ack1(data);	 /* Get Init Parameters */
	   pktnum = 0; prvpkt = -1; }

<serve>G { srvptr = srvcmd; decode(data,putsrv); /* Get & decode command. */
	   putsrv('\0'); putsrv('\0');
	   sstate = srvcmd[0]; BEGIN generic; }

<serve>C { srvptr = srvcmd;		    	 /* Get command for shell */
	   decode(data,putsrv); putsrv('\0');
	   if (syscmd(srvcmd,"")) BEGIN ssinit;
	   else { errpkt("Can't do system command"); SERVE; } }

<serve>. { errpkt("Unimplemented server function"); SERVE; } /* Other */

<generic>C { if (!cwd(srvcmd+1)) errpkt("Can't change directory"); /* CWD */
    	     SERVE; }

<generic>D { if (syscmd(DIRCMD,srvcmd+2)) BEGIN ssinit;	/* Directory */
    	     else { errpkt("Can't list directory"); SERVE; } }

<generic>E { if (syscmd(DELCMD,srvcmd+2)) BEGIN ssinit;	/* Erase */
    	     else { errpkt("Can't remove file"); SERVE; } }

<generic>F { ack(); screen(SCR_TC,0,0l,""); return(0); } /* Finish and Bye */
<generic>L { ack(); ttres(); screen(SCR_TC,0,0l,""); return(zkself()); }

<generic>H { if (sndhlp()) BEGIN ssinit;
    	     else { errpkt("Can't send help"); SERVE; } }

<generic>T { if (syscmd(TYPCMD,srvcmd+2)) BEGIN ssinit;
    	     else { errpkt("Can't type file"); SERVE; } }

<generic>U { x = *(srvcmd+1);			/* Disk Usage query */
    	     x = ((x == '\0') || (x == unchar(0)));
	     x = (x ? syscmd(SPACMD,"") : syscmd(SPACM2,srvcmd+2));
    	     if (x) BEGIN ssinit; else { errpkt("Can't check space"); SERVE; }}

<generic>W { if (syscmd(WHOCMD,srvcmd+2)) BEGIN ssinit;
    	     else { errpkt("Can't do who command"); SERVE; } }

<generic>. { errpkt("Unimplemented generic server function"); SERVE; }

/* Dynamic states, cont'd */


<rgen>Y { decode(data,puttrm); RESUME; }    /* Got reply in ACK data */

<rgen,rfile>F { if (rcvfil()) { ack(); BEGIN rdata; }	/* A file is coming */
		else { errpkt("Can't open file"); RESUME; } }

<rgen,rfile>X { opent(); ack(); BEGIN rdata; }	/* Screen data is coming */

<rfile>B { ack(); reot(); RESUME; }	/* Got End Of Transmission */

<rdata>D { if (cxseen) ack1("X");	/* Got data. */
    	   else if (czseen) ack1("Z");
	   else ack();
	   decode(data,putfil); }

<rdata>Z { ack(); reof(); BEGIN rfile; }    /* Got End Of File */

<ssinit>Y {  int x; char *s;		/* Got ACK to Send-Init */
    	     spar(data);
    	     bctu = bctr;
	     if (xflg) { x = sxpack(); s = "Can't execute command"; }
	    	  else { x = sfile(); s = "Can't open file"; }
	     if (x) BEGIN ssdata; else { errpkt(s); RESUME; }
          }	    

<ssdata>Y { if (canned(data) || !sdata()) { /* Got ACK to data */
		clsif(); seof();
		BEGIN sseof; } }

<sseof>Y { if (gnfile() > 0) {		/* Got ACK to EOF, get next file */
		if (sfile()) BEGIN ssdata;
		else { errpkt("Can't open file") ; RESUME; }
	   } else {			/* If no next file, EOT */
		seot();
		BEGIN sseot; } }

<sseot>Y { RESUME; }			/* Got ACK to EOT */

E { ermsg(data);			/* Error packet, issue message */
    x = quiet; quiet = 1;		/* Close files silently */
    clsif(); clsof();
    quiet = x; RESUME; }

. { nack(); }				/* Anything else, send NAK */
%%

/*  P R O T O  --  Protocol entry function  */

proto() {

    extern int sigint();
    int x;

    conint(sigint);			/* Enable console interrupts */

/* Set up the communication line for file transfer. */

    if (local && (speed < 0)) {
	screen(SCR_EM,0,0l,"Sorry, you must 'set speed' first");
	return;
    }

    x = -1;
    if (ttopen(ttname,&x,mdmtyp) < 0) {
	debug(F111,"proto ttopen local",ttname,local);
	screen(SCR_EM,0,0l,"Can't open line");
	return;
    }
    if (x > -1) local = x;
    debug(F111,"proto ttopen local",ttname,local);

    x = (local) ? speed : -1;
    if (ttpkt(x,flow) < 0) {		/* Put line in packet mode, */
	screen(SCR_EM,0,0l,"Can't condition line");
	return;
    }
    if (sstate == 'x') {		/* If entering server mode, */
	server = 1;			/* set flag, */
	if (!quiet) {
	    if (!local)			/* and issue appropriate message. */
	    	conol(srvtxt);
	    else {
	    	conol("Entering server mode on ");
		conoll(ttname);
	    }
	}
    } else server = 0;
    sleep(1);

/*
 The 'wart()' function is generated by the wart program.  It gets a
 character from the input() routine and then based on that character and
 the current state, selects the appropriate action, according to the state
 table above, which is transformed by the wart program into a big case
 statement.  The function is active for one transaction.
*/

    wart();				/* Enter the state table switcher. */
    
    if (server) {			/* Back from packet protocol. */
	server = 0;
    	if (!quiet)  			/* Give appropriate message */
	    conoll("C-Kermit server done");
    }
    screen(SCR_TC,0,0l,"");		/* Transaction complete */
}