Context Navigation

ckcfn2.c @ 20081

Visit:

Revision 20081, 95.5 KB checked in by zacheiss, 21 years ago (diff)
This commit was generated by cvs2svn to compensate for changes in r20080, which included commits to RCS files with non-trunk default branches.

Rev	Line
[10779]	1	/* C K C F N 2 -- System-independent Kermit protocol support functions... */
	2
	3	/* ...Part 2 (continued from ckcfns.c) */
	4
	5	/*
	6	Author: Frank da Cruz <fdc@columbia.edu>,
	7	Columbia University Academic Information Systems, New York City.
	8
[20080]	9	Copyright (C) 1985, 2002,
	10	Trustees of Columbia University in the City of New York.
	11	All rights reserved. See the C-Kermit COPYING.TXT file or the
	12	copyright text in the ckcmai.c module for disclaimer and permissions.
[10779]	13	*/
	14	/*
	15	Note -- if you change this file, please amend the version number and date at
	16	the top of ckcfns.c accordingly.
	17	*/
	18
	19	#include "ckcsym.h" /* Compilation options */
	20	#include "ckcdeb.h" /* Debugging and other symbols */
	21	#include "ckcasc.h" /* ASCII symbols */
	22	#include "ckcker.h" /* Kermit symbols */
	23	#include "ckcxla.h" /* Translation */
[20080]	24	#include "ckcnet.h" /* IKS and VMS #define TCPSOCKET */
[10779]	25	#ifdef TCPSOCKET /* For TELNET business in spack() */
[20080]	26	extern int tn_nlm, ttnproto, tn_b_nlm;
[10779]	27	#endif /* TCPSOCKET */
	28
[20080]	29	extern int parity, network, local, interrupted, fatalio, wasclosed;
[10779]	30
[20080]	31	int kstartactive = 0; /* Flag for kstart() in a packet */
[10779]	32
	33	static CHAR p_tbl[] = { /* Even parity table for dopar(). */
	34	(CHAR) '\000', /* ANSI C casts '\ooo' constants */
	35	(CHAR) '\201', /* to signed char, so we have to */
	36	(CHAR) '\202', /* cast back to unsigned char... */
	37	(CHAR) '\003',
	38	(CHAR) '\204',
	39	(CHAR) '\005',
	40	(CHAR) '\006',
	41	(CHAR) '\207',
	42	(CHAR) '\210',
	43	(CHAR) '\011',
	44	(CHAR) '\012',
	45	(CHAR) '\213',
	46	(CHAR) '\014',
	47	(CHAR) '\215',
	48	(CHAR) '\216',
	49	(CHAR) '\017',
	50	(CHAR) '\220',
	51	(CHAR) '\021',
	52	(CHAR) '\022',
	53	(CHAR) '\223',
	54	(CHAR) '\024',
	55	(CHAR) '\225',
	56	(CHAR) '\226',
	57	(CHAR) '\027',
	58	(CHAR) '\030',
	59	(CHAR) '\231',
	60	(CHAR) '\232',
	61	(CHAR) '\033',
	62	(CHAR) '\234',
	63	(CHAR) '\035',
	64	(CHAR) '\036',
	65	(CHAR) '\237',
	66	(CHAR) '\240',
	67	(CHAR) '\041',
	68	(CHAR) '\042',
	69	(CHAR) '\243',
	70	(CHAR) '\044',
	71	(CHAR) '\245',
	72	(CHAR) '\246',
	73	(CHAR) '\047',
	74	(CHAR) '\050',
	75	(CHAR) '\251',
	76	(CHAR) '\252',
	77	(CHAR) '\053',
	78	(CHAR) '\254',
	79	(CHAR) '\055',
	80	(CHAR) '\056',
	81	(CHAR) '\257',
	82	(CHAR) '\060',
	83	(CHAR) '\261',
	84	(CHAR) '\262',
	85	(CHAR) '\063',
	86	(CHAR) '\264',
	87	(CHAR) '\065',
	88	(CHAR) '\066',
	89	(CHAR) '\267',
	90	(CHAR) '\270',
	91	(CHAR) '\071',
	92	(CHAR) '\072',
	93	(CHAR) '\273',
	94	(CHAR) '\074',
	95	(CHAR) '\275',
	96	(CHAR) '\276',
	97	(CHAR) '\077',
	98	(CHAR) '\300',
	99	(CHAR) '\101',
	100	(CHAR) '\102',
	101	(CHAR) '\303',
	102	(CHAR) '\104',
	103	(CHAR) '\305',
	104	(CHAR) '\306',
	105	(CHAR) '\107',
	106	(CHAR) '\110',
	107	(CHAR) '\311',
	108	(CHAR) '\312',
	109	(CHAR) '\113',
	110	(CHAR) '\314',
	111	(CHAR) '\115',
	112	(CHAR) '\116',
	113	(CHAR) '\317',
	114	(CHAR) '\120',
	115	(CHAR) '\321',
	116	(CHAR) '\322',
	117	(CHAR) '\123',
	118	(CHAR) '\324',
	119	(CHAR) '\125',
	120	(CHAR) '\126',
	121	(CHAR) '\327',
	122	(CHAR) '\330',
	123	(CHAR) '\131',
	124	(CHAR) '\132',
	125	(CHAR) '\333',
	126	(CHAR) '\134',
	127	(CHAR) '\335',
	128	(CHAR) '\336',
	129	(CHAR) '\137',
	130	(CHAR) '\140',
	131	(CHAR) '\341',
	132	(CHAR) '\342',
	133	(CHAR) '\143',
	134	(CHAR) '\344',
	135	(CHAR) '\145',
	136	(CHAR) '\146',
	137	(CHAR) '\347',
	138	(CHAR) '\350',
	139	(CHAR) '\151',
	140	(CHAR) '\152',
	141	(CHAR) '\353',
	142	(CHAR) '\154',
	143	(CHAR) '\355',
	144	(CHAR) '\356',
	145	(CHAR) '\157',
	146	(CHAR) '\360',
	147	(CHAR) '\161',
	148	(CHAR) '\162',
	149	(CHAR) '\363',
	150	(CHAR) '\164',
	151	(CHAR) '\365',
	152	(CHAR) '\366',
	153	(CHAR) '\167',
	154	(CHAR) '\170',
	155	(CHAR) '\371',
	156	(CHAR) '\372',
	157	(CHAR) '\173',
	158	(CHAR) '\374',
	159	(CHAR) '\175',
	160	(CHAR) '\176',
	161	(CHAR) '\377'
	162	};
	163
[20080]	164	/* D O P A R -- Add an appropriate parity bit to a character */
	165
	166	CHAR
	167	#ifdef CK_ANSIC
	168	dopar(register CHAR ch)
	169	#else
	170	dopar(ch) register CHAR ch;
	171	#endif /* CK_ANSIC */
	172	{
	173	register unsigned int a;
	174	if (!parity
	175	#ifdef TCPSOCKET
	176	\|\| (network && (ttnproto == NP_TELNET) && (TELOPT_ME(TELOPT_BINARY)))
	177	#ifndef NOXFER
	178	\|\| (!local && sstelnet) /* TELNET BINARY MODE */
	179	#endif /* NOXFER */
	180	#endif /* TCPSOCKET */
	181	) return((CHAR) (ch & 255)); else a = ch & 127;
	182	switch (parity) {
	183	case 'e': return(p_tbl[a]); /* Even */
	184	case 'm': return((CHAR) (a \| 128)); /* Mark */
	185	case 'o': return((CHAR) (p_tbl[a] ^ 128)); /* Odd */
	186	case 's': return((CHAR) a); /* Space */
	187	default: return((CHAR) a); /* Something illegal */
	188	}
	189	}
	190
	191	#ifndef NOXFER /* Rest of this file... */
	192
	193	#define NEWDPL /* New dynamic packet length method */
	194
	195	#ifdef VMS
	196	extern int batch;
	197	#else
	198	extern int backgrd;
	199	#endif /* VMS */
	200
	201	#ifdef DYNAMIC
	202	extern struct pktinfo s_pkt; / array of pktinfo structures */
	203	extern struct pktinfo r_pkt; / array of pktinfo structures */
	204	#else
	205	extern struct pktinfo s_pkt[]; /* array of pktinfo structures */
	206	extern struct pktinfo r_pkt[]; /* array of pktinfo structures */
	207	#endif /* DYNAMIC */
	208
	209	extern int sseqtbl[], rseqtbl[], sbufuse[], sacktbl[], wslots, winlo, wslotn,
	210	sbufnum, rbufnum, pktpaus, reliable;
	211
	212	#ifdef STREAMING
	213	static int dontsend = 0;
	214	extern int streaming;
	215	#endif /* STREAMING */
	216
	217	extern int ttprty; /* from cktio.c /
	218	extern int autopar;
	219
	220	extern int spsiz, spmax, rpsiz, timint, timef, npad, bestlen, maxsend;
	221	extern int rpt, rptq, rptflg, capas, spsizf, en_fin, tsecs, flow;
	222	extern int pktnum, sndtyp, rcvtyp, bctr, bctu, bctl, rsn, rln, maxtry, size;
	223	extern int osize, maxsize, spktl, rpktl, nfils, stdouf, fsecs;
	224	extern int turn, turnch, displa, pktlog, seslog, xflg, mypadn;
	225	extern int hcflg, server, cxseen, czseen, discard, slostart;
	226	extern int nakstate, quiet, success, xitsta, what, filestatus;
	227	extern int spackets, rpackets, timeouts, retrans, crunched, urpsiz;
	228	extern int carrier, fdispla, srvidl;
	229
	230	#ifdef GFTIMER
	231	extern CKFLOAT fptsecs, fpfsecs, fpxfsecs;
	232	#endif /* GFTIMER */
	233
	234	extern long filcnt, filrej, ffc, flci, flco, tlci, tlco, tfc, speed;
	235	extern long filcps, tfcps;
	236
	237	extern char *cmarg, filnam[];
	238
	239	extern CHAR padch, mypadc, eol, seol, ctlq, sstate;
	240	extern CHAR recpkt, data, myinit[];
	241	extern CHAR srvptr, stchr, mystch, rdatap;
	242	extern CHAR padbuf[];
	243	extern CHAR * epktmsg;
	244	extern int epktrcvd, epktsent;
	245
	246	#ifdef OS2 /* AUTODOWNLOAD parameters */
	247	extern int adl_kmode, adl_zmode; /* Match Packet to signal download */
	248	extern char * adl_kstr; /* KERMIT Download String */
	249	extern char * adl_zstr; /* ZMODEM Download String */
	250	#endif /* OS2 */
	251
	252	#ifdef CK_AUTODL
	253	CHAR ksbuf[96] = { NUL, NUL }; /* Autodownload "Kermit Start" buf */
	254	#endif /* CK_AUTODL */
	255
	256	int numerrs = 0; /* Number of packet errors so far */
	257	int rcvtimo = 0; /* Timeout for receiving a packet */
	258	int idletmo = 0; /* Flag for idle timeout */
	259
	260	long filcps = 0L; /* CPS most recent file transferred */
	261	long tfcps = 0L; /* CPS most recent transaction */
	262	long xfsecs = 0L; /* Elapsed time for most recent file */
	263	#ifdef GFTIMER
	264	CKFLOAT fpxfsecs = 0.0; /* Ditto, but floating point */
	265	#endif /* GFTIMER */
	266
	267	#ifdef CK_TIMERS
	268	int rrttbl[64], srttbl[64]; /* Packet timestamp tables */
	269	extern int rttflg;
	270	#define RTT_SCALE 1000
	271	long
	272	rttsamples, /* Round trip time samples */
	273	rttdelay, /* RTT delay */
	274	pktintvl, /* Interpacket arrival time */
	275	rttvariance, /* RTT variance */
	276	rttstddev; /* RTT standard deviation */
	277	#endif /* CK_TIMERS */
	278
[10779]	279	/* CRC generation tables */
	280
	281	long crcta[16] = { 0L, 010201L, 020402L, 030603L, 041004L,
	282	051205L, 061406L, 071607L, 0102010L, 0112211L, 0122412L, 0132613L, 0143014L,
	283	0153215L, 0163416L, 0173617L
	284	};
	285
	286	long crctb[16] = { 0L, 010611L, 021422L, 031233L, 043044L,
	287	053655L, 062466L, 072277L, 0106110L, 0116701L, 0127532L, 0137323L, 0145154L,
	288	0155745L, 0164576L, 0174367L
	289	};
	290
	291	#ifdef CK_TIMERS
	292	/*
	293	Round-trip timer calculations adapted from Tim Kientzle's article,
	294	"Improving Kermit Performance", Dr Dobb's Journal, February 1996.
	295	*/
	296
[20080]	297
[10779]	298	/* R T T I N I T -- Initialize timers at start of transaction */
	299
	300	VOID
	301	rttinit() { /* Initialize round-trip timing */
	302	int i;
	303
[20080]	304	if (timint == 0)
	305	return;
	306
[10779]	307	rttsamples = 0L; /* Samples (packets) */
	308	rttvariance = 0L; /* Variance in delay */
	309	rttdelay = (long) timint * RTT_SCALE; /* Delay */
	310	pktintvl = (long) timint * RTT_SCALE; /* Delay */
	311	rttstddev = (long) timint * RTT_SCALE; /* Standard deviation of delay */
	312
	313	/* Tables of timestamps indexed by packet sequence number */
	314
[20080]	315	for (i = 0; i < 64; i++) {
[10779]	316	rrttbl[i] = -1; /* Time each packet was received */
	317	srttbl[i] = -1; /* Time each packet was sent */
	318	}
	319	rcvtimo = timint; /* Initial timeout is what user said */
	320	}
	321
	322	/* G E T R T T -- Get packet round trip time */
	323	/*
	324	Call with nakstate == 0 if file sender, nonzero if receiver,
	325	and n == packet sequence number of the packet we just received.
[20080]	326
[10779]	327	Returns:
	328	-1 on failure with rcvtimo set to timint (what the user said), or:
	329	0 on success with rcvtimo set to dynamically calculated value:
	330	1 <= rcvtimo <= timint * 3.
	331	*/
	332	int
	333	getrtt(nakstate, n) int nakstate, n; {
	334	extern int mintime, maxtime;
[20080]	335	static int prevz = 0, prevr = 0;
[10779]	336	int x, y, yy, z = 0, zz = 0; /* How long did it take to get here? */
	337
	338	rcvtimo = timint; /* Default timeout is what user said */
	339
	340	if (timint == 0) /* We're not timing out. */
	341	return(0);
	342
	343	if (!rttflg) /* Not supposed to be doing this? */
	344	return(-1); /* So don't */
	345
	346	if (!RTT_SCALE) /* Paranoia... */
	347	return(-1);
	348
	349	/* rtimer() (reset timer) is not called until 1st data packet */
[20080]	350	#ifdef GFTIMER
	351	/* rftimer(); */
	352	#endif /* GFTIMER */
[10779]	353	/* S (F [ A ] D* Z)* B */
	354
	355	/* NOTE: we calculate both the round-trip time AND the packet */
	356	/* arrival rate. We don't use the RTT for anything, we just display it. */
	357	/* Timeouts are based on the packet arrival rate. */
	358
	359	if (spackets > 3) { /* Don't start till 4th packet */
	360	if (nakstate) { /* File receiver */
	361	x = rrttbl[n]; /* Time when I got packet n */
	362	y = rrttbl[n > 0 ? n - 1 : 63]; /* Time when I got packet n-1 */
	363	yy = srttbl[n > 0 ? n - 1 : 63]; /* Time when I sent ACK(n-1) */
	364	if (x > -1 && y > -1) { /* Be careful */
	365	z = x - y; /* Packet rate */
	366	zz = x - yy; /* Round trip time */
[20080]	367	z++; /* So sender & receiver differ */
[10779]	368	debug(F101,"RTT RECV","",z);
	369	} else { /* This shouldn't happen */
	370	debug(F101,"RTT RECV ERROR spackets","",spackets);
	371	debug(F101,"RTT RECV ERROR sequence","",n);
	372	return(-1);
	373	}
	374	} else { /* File sender */
	375	x = rrttbl[n]; /* Time when I got ACK(n) */
	376	y = rrttbl[n > 0 ? n - 1 : 63]; /* Time when I got packet n-1 */
	377	yy = srttbl[n]; /* Time when I sent n */
	378	if (x > -1 && y > -1) {
	379	z = x - y; /* Packet rate */
	380	zz = x - yy; /* Round trip time */
	381	debug(F101,"RTT SEND","",z);
	382	} else {
	383	debug(F100,"RTT SEND ERROR","",0);
	384	return(-1);
	385	}
	386	}
	387	if (z < 1) /* For fast connections */
	388	z = RTT_SCALE / 2; /* Convert to scale... */
	389	else
	390	z *= RTT_SCALE;
[20080]	391	debug(F101,"RTT z scaled","",z);
[10779]	392
	393	if (zz < 1) /* For fast connections */
	394	zz = RTT_SCALE / 2; /* Convert to scale... */
	395	else
	396	zz *= RTT_SCALE;
	397
	398	rttdelay = zz; /* Round trip time of this packet */
[20080]	399	#ifdef COMMENT
	400	/*
	401	This was used in C-Kermit 7.0 (and 6.0?) but not only is it overkill,
	402	it also can produce ridiculously long timeouts under certain conditions.
	403	Replaced in 8.0 by a far simpler and more aggressive strategy.
	404	*/
[10779]	405	if (rttsamples++ == 0L) { /* First sample */
	406	pktintvl = z;
	407	} else { /* Subsequent samples */
	408	long oldavg = pktintvl;
	409	long rttdiffsq;
	410
	411	if (rttsamples > 30) /* Use real average for first 30 */
	412	rttsamples = 30; /* then decaying average. */
	413
	414	/* Average delay, difference squared, variance, std deviation */
	415
	416	pktintvl += (z - pktintvl) / rttsamples;
	417	rttdiffsq = (z - oldavg) * (z - oldavg);
	418	rttvariance += (rttdiffsq - rttvariance) / rttsamples;
	419	debug(F101,"RTT stddev1","",rttstddev);
	420	if (rttstddev < 1L) /* It can be zero, in which case */
	421	rttstddev = RTT_SCALE / 3; /* set it to something small... */
	422	rttstddev = (rttstddev + rttvariance / rttstddev) / 2;
	423	}
	424	debug(F101,"RTT stddev2","",rttstddev);
	425	debug(F101,"RTT delay ","",pktintvl);
	426	rcvtimo = (pktintvl + (3L * rttstddev)) / RTT_SCALE + 1;
	427	if (rpackets < 32) /* Allow for slow start */
	428	rcvtimo += rcvtimo + 2;
	429	else if (rpackets < 64)
	430	rcvtimo += rcvtimo / 2 + 1;
[20080]	431	/* On a reliable link, don't try too hard to time out. */
	432	/* Especially on fast local network connections. */
	433	if (server && what == W_NOTHING) /* Server command wait */
	434	rcvtimo = rcvtimo; /* == srvtim */
	435	else if (reliable == SET_ON && rcvtimo > 0) /* Reliable */
	436	rcvtimo = rcvtimo +15; /* and not server command wait */
	437	else /* Not reliable or server cmd wait */
	438	rcvtimo = rcvtimo;
[10779]	439	if (rcvtimo < mintime) /* Lower bound */
	440	rcvtimo = mintime;
	441	if (maxtime > 0) { /* User specified an upper bound */
	442	if (rcvtimo > maxtime)
	443	rcvtimo = maxtime;
	444	} else if (maxtime == 0) { /* User didn't specify */
	445	if (rcvtimo > timint * 6)
	446	rcvtimo = timint * 6;
	447	}
[20080]	448	#else /* COMMENT */
	449	#ifdef CKFLOAT
	450	{
	451	CKFLOAT x;
	452	x = (CKFLOAT)(prevz + z + z) / 3.0;
	453	rcvtimo = (int)((((CKFLOAT)x * 2.66) / RTT_SCALE) + 0.5);
	454	debug(F101,"RTT rcvtimo (float)","",rcvtimo);
	455	}
	456	#else
	457	rcvtimo = (prevz + z + z) / RTT_SCALE;
	458	debug(F101,"RTT rcvtimo (int)","",rcvtimo);
	459	#endif /* CKFLOAT */
	460	#endif /* COMMENT */
	461
	462	zz = (rttdelay + 500) / 1000;
	463	if (rcvtimo > (zz * 3))
	464	rcvtimo = zz * 3;
	465
	466	if (rcvtimo < 1)
	467	rcvtimo = 1;
	468	if (mintime > 0) {
	469	if (rcvtimo < mintime) /* Lower bound */
	470	rcvtimo = mintime;
	471	}
	472	if (maxtime > 0) { /* Upper bound */
	473	if (rcvtimo > maxtime)
	474	rcvtimo = maxtime;
	475	}
	476	if (rcvtimo == (prevr - 1))
	477	rcvtimo++;
	478
	479	debug(F101,"RTT final rcvtimo","",rcvtimo);
[10779]	480	}
[20080]	481	prevz = z;
	482	prevr = rcvtimo;
[10779]	483	return(0);
	484	}
	485	#endif /* CK_TIMERS */
	486
	487	/* I N P U T -- Attempt to read packet number 'pktnum'. */
	488
	489	/*
	490	This is the function that feeds input to Kermit's finite state machine,
	491	in the form of a character in the range 32-126, normally a packet type
	492	(uppercase letter) or pseudo-packet-type (lowercase letter).
	493
	494	If a special start state is in effect, that state is returned as if it were
	495	the type of an incoming packet.
	496	*/
	497	int
	498	input() {
[20080]	499	int type = 0, acktype; /* Received packet type */
[10779]	500	int x, y, k; /* Workers */
	501	int z, pi, nf; /* Worker, packet index, NAK flag */
	502	int nak2ack = 0;
	503
[20080]	504	debug(F000,"input sstate","",sstate);
	505	debug(F101,"input nakstate","",nakstate);
	506	debug(F000,"input sndtyp","",sndtyp);
	507	debug(F101,"input xitsta","",xitsta);
	508	debug(F101,"input what","",what);
[10779]	509
	510	while (1) { /* Big loop... */
[20080]	511	/*
	512	It is ttchk()'s responsibility to tell us if the connection is broken,
	513	and to do so instantly and nondestructively -- no blocking, etc, that would
	514	slow down file transfer.
	515	*/
	516	if (ttchk() < 0) {
	517	debug(F100,"input CONNECTION BROKEN","",0);
	518	fatalio = 1;
	519	return('q');
	520	}
[10779]	521	if (sstate != 0) { /* If a start state is in effect, */
	522	type = sstate; /* return it like a packet type, */
	523	sstate = 0; /* and then nullify it. */
	524	numerrs = 0; /* (PWP) no errors so far */
	525	return(type);
	526	}
	527	if (nakstate) { /* This section for file receiver. */
	528	if (wslots > 1) { /* If we're doing windows, */
	529	x = rseqtbl[winlo]; /* see if desired packet already in. */
[20080]	530	debug(F101,"input winlo","",winlo);
	531	debug(F101,"input rseqtbl[winlo]","",rseqtbl[winlo]);
[10779]	532	if (x > -1) { /* Already there? */
	533	if (r_pkt[x].pk_seq == winlo) { /* (double check) */
	534	rsn = winlo; /* Yes, return its info */
	535	debug(F101,"input return pre-stashed packet","",rsn);
	536	dumprbuf();
	537	rdatap = r_pkt[x].pk_adr; /* like rpack would do. */
	538	rln = (int)strlen((char *) rdatap);
	539	type = r_pkt[x].pk_typ;
	540	break;
	541	}
	542	}
	543	}
	544	type = rpack(); /* Try to read a packet. */
[20080]	545	debug(F101,"input rpack","",type);
	546
[10779]	547	while (type == 'e') { /* Handle echoes */
[20080]	548	debug(F101,"input echo discarded","",type);
	549	type = rpack();
	550	}
	551	#ifdef DEBUG
	552	if (deblog) {
	553	if (type == 'D')
	554	debug(F011,"input type D=",(char *)rdatap,39);
	555	else
	556	debug(F000,"input type",(char *)rdatap,type);
	557	}
	558	#endif /* DEBUG */
[10779]	559	#ifndef OLDCHKINT
	560	if (type == 'z') {
[20080]	561	epktrcvd = 1;
[10779]	562	errpkt((CHAR *)"User cancelled.");
	563	type = 'E';
	564	break;
	565	}
	566	#endif /* OLDCHKINT */
[20080]	567	if (type < -1) {
	568	char * s;
	569	s = (type == -2) ?
	570	"FAILED - Interrupted" :
	571	"FAILED - Connection lost";
	572
	573	xxscreen(SCR_PT,'q',0L,s);
	574	dologend();
	575	return('q'); /* Ctrl-C or connection lost */
	576	}
[10779]	577	if (type < 0) { /* Receive window full */
	578	/* Another thing to do here would be to delete */
	579	/* the highest packet and NAK winlo. But that */
	580	/* shouldn't be necessary since the other Kermit */
	581	/* should not have sent a packet outside the window. */
[20080]	582	#ifdef COMMENT
	583	char foo[256];
	584	ckmakxmsg(foo,256,"Receive window full (rpack): wslots=",
	585	ckitoa(wslots)," winlo=",ckitoa(winlo)," pktnum=",
	586	ckitoa(pktnum), NULL,NULL,NULL,NULL,NULL,NULL);
	587	errpkt((CHAR *)foo);
	588	debug(F100,foo,"",0);
	589	#else
	590	errpkt((CHAR *)"Receive window full");
[10779]	591	debug(F101,"rpack receive window full","",0);
[20080]	592	debug(F101," wslots","",wslots);
	593	debug(F101," winlo","",winlo);
	594	debug(F101," pktnum","",pktnum);
	595	#endif
[10779]	596	dumprbuf();
	597	type = 'E';
	598	break;
	599	}
	600	dumprbuf();
	601
	602	#ifdef OLDCHKINT
	603	if (chkint() < 0) { /* Check for console interrupts. */
[20080]	604	errpkt((CHAR )"User cancelled."); / (old way) */
[10779]	605	type = 'E';
	606	break;
	607	}
	608	#endif /* OLDCHKINT */
	609
[20080]	610	#ifdef STREAMING
	611	if (streaming) { /* Streaming */
	612	if (type == 'Q' \|\| type == 'T') { /* Errors are fatal. */
	613	crunched++; /* For statistics */
	614	errpkt((CHAR *)"Transmission error on reliable link.");
	615	type = 'E';
	616	}
	617	}
	618	#endif /* STREAMING */
[10779]	619	if (type == 'E') {
	620	debug(F101,"input got E, nakstate","",nakstate);
	621	break; /* Error packet */
	622	}
	623	if (type == 'Q') { /* Crunched packet. */
	624	crunched++;
	625	numerrs++;
	626	/*
	627	Packet arrived damaged. It was most likely the packet we were expecting
	628	next, so we send a NAK for that packet. Prior to 5A(189), we always
	629	NAK'd winlo here, but that was bad because if two (or more) different
	630	packets were damaged, we would keep NAKing the first one and never NAK the
	631	other ones, which could result in a lengthy series of timeouts. Now we
	632	NAK the oldest as-yet-unNAK'd missing packet.
	633	*/
	634	#ifdef CK_TIMERS
	635	rcvtimo++; /* Stretch the timeout a little */
	636	#endif /* CK_TIMERS */
	637	z = (winlo + wslots) % 64; /* Search from winlo to z */
	638	debug(F101,"ZZZ crunched z","",z);
	639	nf = 0; /* NAK flag not set yet */
	640	for (x = winlo; x != z; x = (x + 1) % 64) {
	641	debug(F101,"ZZZ x","",x);
	642	if (rseqtbl[x] > -1) /* Have I received packet x? */
	643	continue; /* Yes, go on. */
	644	debug(F101,"ZZZ x not recd yet","",x);
	645	pi = sseqtbl[x]; /* No, have I NAK'd it yet? */
	646	if (pi < 0 \|\| s_pkt[pi].pk_rtr == 0) {
	647	debug(F101,"ZZZ x not NAK'd yet","",x);
	648	nack(x); /* No, NAK it now. */
	649	nf = 1; /* Flag that I did. */
	650	break;
	651	}
	652	}
	653	if (!nf) { /* If we didn't NAK anything above, */
	654	debug(F101,"ZZZ NAKing winlo","",winlo);
	655	if (nack(winlo) < 0) { /* we have to NAK winlo (again) */
	656	errpkt((CHAR )"Too many retries."); / Too many */
	657	type = 'E';
	658	break;
	659	}
[20080]	660	}
[10779]	661	continue;
	662	}
	663
	664	if (type == 'T') { /* Timeout */
[20080]	665	#ifndef OS2
	666	/* K95 does this its own way */
	667	if (server && srvidl) {
	668	idletmo = 1;
	669	debug(F101,"SERVER IDLE TIMEOUT","",srvidl);
	670	return('q');
	671	}
	672	#endif /* OS2 */
[10779]	673	#ifdef CK_TIMERS
	674	rcvtimo++; /* Stretch the timeout a little */
	675	#endif /* CK_TIMERS */
	676	timeouts++;
	677	debug(F101,"input receive-state timeout, winlo","",winlo);
	678	/* NAK only the packet at window-low */
	679	debug(F101,"input sending NAK for winlo","",winlo);
[20080]	680	x = ttchk();
	681	if (x > 0) /* Don't give up if there is still */
[10779]	682	continue; /* something to read. */
[20080]	683	else if (x < 0) {
	684	dologend();
	685	fatalio = 1;
	686	return('q'); /* Connection Lost */
	687	}
[10779]	688	if (nack(winlo) < 0) {
	689	debug(F101,"input sent too many naks","",winlo);
	690	errpkt((CHAR *)"Too many retries.");
	691	type = 'E';
	692	break;
	693	} else continue;
	694	}
	695	if (rsn == winlo) { /* Got the packet we want, done. */
	696	#ifdef CK_TIMERS
[20080]	697	if (rttflg && timint) /* Dynamic round trip timers? */
[10779]	698	getrtt(nakstate, rsn); /* yes, do it. */
	699	#endif /* CK_TIMERS */
	700	debug(F101,"input rsn=winlo","",rsn);
	701	break;
	702	}
	703
	704	/* Got a packet out of order. */
	705
[20080]	706	debug(F101,"input out of sequence, rsn","",rsn);
[10779]	707	k = rseqtbl[rsn]; /* Get window slot of this packet. */
[20080]	708	debug(F101,"input rseqtbl[rsn]","",k);
[10779]	709	if (k < 0) {
	710	debug(F101,"input recv can't find index for rcvd pkt","",rsn);
	711	/* Was "Internal error 21" */
[20080]	712	/* This should not happen */
[10779]	713	errpkt((CHAR *)"Sliding windows protocol error.");
	714	type = 'E';
	715	break;
[20080]	716	}
[10779]	717	y = chkwin(rsn,winlo,wslots); /* See what window it's in. */
	718	debug(F101,"input recv chkwin","",y);
	719	if (y == 1) { /* From previous window. */
[20080]	720	#ifdef STREAMING
	721	if (!streaming) /* NO RESEND IF STREAMING! */
	722	#endif /* STREAMING */
	723	resend(rsn); /* Resend the ACK (might have data) */
[10779]	724	freerpkt(rsn); /* Get rid of received packet */
[20080]	725	continue; /* Back to wait for another packet */
[10779]	726	} else { /* In this window or out of range */
	727	if (y < 0) /* If out of range entirely, */
	728	freerpkt(rsn); /* release its buffer */
	729
[20080]	730	#ifdef STREAMING
	731	if (streaming) { /* Streaming (this shouldn't happen) */
	732	errpkt((CHAR *)"Sequence error on reliable link.");
	733	type = 'E';
	734	break;
	735	}
	736	#endif /* STREAMING */
[10779]	737
[20080]	738	/* If our receive window is full, NAK window-low */
[10779]	739
	740	if (rbufnum < 1) { /* Receive window full? */
	741	if (nack(winlo) < 0) { /* No choice, must NAK winlo. */
	742	errpkt((CHAR )"Too many retries."); / Too many */
	743	type = 'E';
	744	break;
	745	} else continue;
	746	}
	747	/*
	748	Receive window not full. This is a packet in the current window but it is
	749	not the desired packet at winlo. So therefore there are gaps before this
	750	packet. So we find the "lowest" unNAK'd missing packet, if any, between
	751	winlo and this one, and NAK it. If there are no as-yet-unNAK'd missing
	752	packets in the window, then we send nothing and go wait for another packet.
	753	In theory, this could result in a timeout, but in practice it is likely that
	754	the already-NAK'd missing packets are already on their way. Note, we do not
	755	NAK ahead of ourselves, as that only creates unnecessary retransmissions.
	756	*/
	757	for (x = winlo; x != rsn; x = (x + 1) % 64) {
	758	if (rseqtbl[x] > -1) /* Have I received packet x? */
	759	continue; /* Yes, check next sequence number. */
	760	pi = sseqtbl[x]; /* No, have I NAK'd it yet? */
	761	if (pi < 0 \|\| s_pkt[pi].pk_rtr == 0) {
	762	nack(x); /* No, NAK it now. */
	763	break;
	764	}
	765	}
	766	}
	767	/!!!/
	768	} else { /* Otherwise file sender... */
	769
[20080]	770	#ifdef STREAMING
	771	if (streaming && sndtyp == 'D') {
	772	debug(F101,"STREAMING input streaming","",streaming);
	773	debug(F000,"STREAMING input sndtyp","",sndtyp);
	774	rsn = winlo;
	775	type = 'Y'; /* Pretend we got an ACK */
	776	}
	777	#endif /* STREAMING */
[10779]	778	if (!nak2ack) { /* NAK(n+1) = ACK(n) */
	779	if (wslots > 1) { /* Packet at winlo already ACK'd? */
	780	if (sacktbl[winlo]) { /* If so, */
	781	sacktbl[winlo] = 0; /* Turn off the ACK'd flag */
	782	winlo = (winlo + 1) % 64; /* Rotate the window */
	783	type = 'Y'; /* And return ACK */
	784	debug(F101,
	785	"input send returning pre-stashed ACK","",
	786	winlo-1);
	787	break;
	788	}
	789	}
[20080]	790	#ifdef STREAMING
	791	if (!(streaming && sndtyp == 'D')) { /* Not streaming \| data */
	792	type = rpack(); /* Try to read an acknowledgement */
	793	} else { /* Streaming and in Data phase */
	794	type = 'Y'; /* Assume all is normal */
	795	if (chkint() < 0) /* Check for console interrupts. */
	796	type = 'z';
	797	else if (ttchk() > 4 + bctu) /* Check for return traffic */
	798	type = rpack();
	799	debug(F000,"input streaming type","",type);
	800	}
	801	#endif /* STREAMING */
[10779]	802	debug(F111,"input send",(char *) rdatap,(int) type);
	803	while (type == 'e') { /* Handle echoes */
	804	debug(F000,"echo discarded","",type);
[20080]	805	type = rpack();
	806	}
[10779]	807	#ifndef OLDCHKINT
	808	if (type == 'z') {
[20080]	809	epktrcvd = 1;
[10779]	810	errpkt((CHAR *)"User cancelled.");
	811	type = 'E';
	812	break;
	813	}
	814	#endif /* OLDCHKINT */
[20080]	815	if (type < -1) {
	816	xxscreen(SCR_PT,'q',0L,
	817	((char *)((type == -2) ?
	818	"Interrupted" :
	819	"Connection lost"))
	820	);
	821	if (type != -2)
	822	dologend();
	823	return('q'); /* Ctrl-C or connection lost */
	824	}
[10779]	825	if (type == -1) {
[20080]	826	#ifdef COMMENT
	827	char foo[256];
	828	ckmakxmsg(foo,256,
	829	"Receive window full (error 18): wslots=",
	830	ckitoa(wslots),
	831	" winlo=",ckitoa(winlo)," pktnum=",
	832	ckitoa(pktnum), NULL,NULL,NULL,NULL,NULL,NULL);
	833	errpkt((CHAR *)foo);
	834	debug(F100,foo,"",0);
	835	#else
[10779]	836	errpkt((CHAR )"Receive window full"); / was "internal */
[20080]	837	debug(F101," wslots","",wslots); /* error 18" */
	838	debug(F101," winlo","",winlo);
[10779]	839	debug(F101," pktnum","",pktnum);
[20080]	840	#endif /* COMMENT */
[10779]	841	dumprbuf();
	842	type = 'E';
	843	break;
	844	}
	845	dumprbuf(); /* Debugging */
	846
	847	#ifdef OLDCHKINT
	848	if (chkint() < 0) { /* Check for console interrupts. */
	849	errpkt((CHAR *)"User cancelled.");
	850	return(type = 'E');
	851	}
	852	#endif /* OLDCHKINT */
	853
	854	/* Got a packet */
	855
[20080]	856	#ifdef STREAMING
	857	if (streaming) { /* Streaming */
	858	if (type == 'Q' \|\| type == 'T') { /* Errors are fatal. */
	859	crunched++; /* For statistics */
	860	errpkt((CHAR *)"Transmission error on reliable link.");
	861	type = 'E';
	862	}
	863	}
	864	#endif /* STREAMING */
[10779]	865	if (type == 'E') {
	866	debug(F101,"input send got E, nakstate","",nakstate);
	867	break; /* Error packet */
	868	}
[20080]	869	if (type == 'Q') { /* Crunched packet */
[10779]	870	crunched++; /* For statistics */
	871	numerrs++; /* For packet resizing */
	872	x = resend(winlo); /* Resend window-low */
	873	if (x < 0) {
	874	type = 'E';
[20080]	875	errpkt((CHAR *)"Too many retries");
[10779]	876	break;
	877	}
	878	continue;
	879	}
	880	if (type == 'T') { /* Timeout waiting for ACKs. */
	881	timeouts++; /* Count it */
	882	numerrs++; /* Count an error too */
	883	debug(F101,"input send state timeout, winlo","",winlo);
	884
	885	/* Retransmit the oldest un-ACK'd packet. */
	886
	887	debug(F101,"input send resending winlo","",winlo);
	888	if (resend(winlo) < 0) { /* Check retries */
	889	debug(F101,"input send too many resends","",maxtry);
[20080]	890	errpkt((CHAR *)"Too many retries");
[10779]	891	return(type = 'E');
	892	}
	893	#ifdef NEWDPL
	894	/* Reduce prevailing packet length */
	895	x = sseqtbl[winlo]; /* Get length of packet we want ACKd */
	896	if (x > -1) { /* Only if we have a valid index */
	897	if (s_pkt[x].pk_typ == 'D') { /* only for D packets */
	898	spsiz = (s_pkt[x].pk_len + 8) >> 1; /* halve it */
	899	if (spsiz < 20) spsiz = 20; /* within reason */
	900	debug(F101,"input T cut packet length","",spsiz);
	901	}
	902	}
	903	#endif /* NEWDPL */
	904	continue;
	905	}
	906	}
	907	/* Got an actual normal packet */
	908
	909	nak2ack = 0; /* Unset this flag. */
	910	y = chkwin(rsn,winlo,wslots); /* Is it in the window? */
	911	debug(F101,"input send rsn","",rsn);
	912	debug(F101,"input send winlo","",winlo);
	913	debug(F101,"input send chkwin","",y);
	914
	915	if (type == 'Y') { /* Got an ACK */
	916	if (y == 0) { /* In current window */
	917	if (spackets < 4) /* Error counter doesn't count */
	918	numerrs = 0; /* until data phase. */
	919	sacktbl[rsn]++; /* Mark the packet as ACK'd */
	920	x = sseqtbl[rsn]; /* Get ACK'd packet's buffer index */
	921	debug(F101,"bestlen ack x","",x);
	922	#ifdef NEWDPL
	923	if (x > -1) {
	924	acktype = s_pkt[x].pk_typ; /* Get type */
	925	debug(F000,"bestlen ack type","",acktype);
	926
	927	if (acktype == 'D') { /* Adjust data packet length */
	928	if (spsiz > bestlen) {
	929	bestlen = spsiz;
	930	debug(F101,"bestlen B","",bestlen);
	931	}
[20080]	932	#ifdef DEBUG
[10779]	933	if (deblog) {
	934	debug(F101,"bestlen retry","",s_pkt[x].pk_rtr);
	935	debug(F101,"bestlen len","",s_pkt[x].pk_len);
	936	debug(F101,"bestlen spackets","",spackets);
	937	}
	938	#endif /* DEBUG */
	939	/* Set new best length */
	940	if (s_pkt[x].pk_rtr == 0 &&
	941	s_pkt[x].pk_len + 8 > bestlen) {
	942	bestlen = s_pkt[x].pk_len + 8;
	943	if (bestlen > spmax)
	944	bestlen = spmax;
	945	debug(F101,"bestlen A","",bestlen);
	946	}
[20080]	947	#ifdef DEBUG
[10779]	948	if (deblog) {
	949	debug(F101,"bestlen wslots","",wslots);
	950	debug(F101,"bestlen maxsend","",maxsend);
	951	}
	952	#endif /* DEBUG */
	953	/* Slow start */
	954	if (slostart &&
	955	(maxsend <= spmax) &&
	956	(rpackets < 11) &&
	957	(numerrs == 0)) {
	958	spsiz = spsiz << 1;
	959	debug(F101,"bestlen spsiz A","",spsiz);
	960
	961	/* Creep up to best length */
	962	} else if ((spackets > 5) &&
	963	(spsiz < bestlen - 8)) {
	964	spsiz += (bestlen - spsiz) / 3;
	965	debug(F101,"bestlen spsiz B","",spsiz);
	966
	967	/* Push the envelope */
	968	} else if ((spackets % (wslots + 1) == 0) &&
	969	(spackets > 6) &&
	970	(bestlen < spmax - 8) &&
	971	(spsiz < spmax)) {
	972	spsiz += (spmax - bestlen) / 3;
	973	debug(F101,"bestlen spsiz C","",spsiz);
	974	}
	975	/* But not too far */
	976	if (spsiz > spmax) {
	977	spsiz = spmax;
	978	debug(F101,"bestlen spsiz D","",spsiz);
	979	}
	980	}
	981	}
	982	#endif /* NEWDPL */
	983
	984	#ifdef CK_TIMERS
[20080]	985	if (rttflg && timint) /* If doing dynamic timers */
[10779]	986	getrtt(nakstate, rsn); /* call routine to set it. */
	987	#endif /* CK_TIMERS */
	988	/*
	989	NOTE: The following statement frees the buffer of the ACK we just got.
	990	But the upper layers still need the data, like if it's the ACK to an I,
	991	S, F, D, Z, or just about any kind of packet. So for now, freerbuf()
	992	deallocates the buffer, but does not erase the data or destroy the pointer
	993	to it. There's no other single place where these receive buffers can be
	994	correctly freed (?) ...
	995	*/
	996	freerpkt(rsn); /* Free the ACK's buffer */
	997	freesbuf(rsn); /* *** Free the sent packet's buffer */
	998	if (rsn == winlo) { /* Got the one we want */
	999	sacktbl[winlo] = 0;
	1000	winlo = (winlo + 1) % 64;
	1001	debug(F101,"input send rotated send window","",winlo);
	1002	break; /* Return the ACK */
	1003	} else {
	1004	debug(F101,"input send mark pkt","",rsn);
	1005	continue; /* Otherwise go read another packet */
	1006	}
	1007	} else if (y == 1 && wslots < 2) { /* (190) ACK for previous */
	1008	numerrs++; /* == NAK for current, count error */
	1009	debug(F101,"input send ACK for previous","",rsn);
	1010	freerpkt(rsn); /* Free NAK's buffer */
	1011	x = resend(winlo); /* Resend current packet */
	1012	if (x < 0) {
	1013	type = 'E';
[20080]	1014	errpkt((CHAR *)"Too many retries");
[10779]	1015	break;
	1016	} else continue; /* Resend ok, go read another packet */
	1017	} else { /* Other cases, just ignore */
	1018	debug(F101,"input send ACK out of window","",rsn);
	1019	freerpkt(rsn);
	1020	continue;
	1021	}
	1022	}
	1023	if (type == 'N') { /* NAK */
	1024	numerrs++; /* Count an error */
[20080]	1025	#ifdef STREAMING
	1026	if (streaming) { /* Streaming */
	1027	errpkt((CHAR *)"NAK received on reliable link.");
	1028	type = 'E';
	1029	break;
	1030	}
	1031	#endif /* STREAMING */
	1032
[10779]	1033	debug(F101,"input send NAK","",rsn);
	1034	#ifdef NEWDPL
	1035	/* Reduce prevailing packet length */
	1036	x = sseqtbl[rsn]; /* Length of packet that was NAK'd */
	1037	if (x > -1) { /* If it's a Data packet we've sent */
	1038	if (s_pkt[x].pk_typ == 'D') {
	1039	spsiz = (s_pkt[x].pk_len + 8) >> 1; /* Halve length */
	1040	#ifdef COMMENT
	1041	/* This might be a good idea -- haven't tried it ... */
	1042	if (bestlen > 0 && spsiz > bestlen)
	1043	spsiz = bestlen;
	1044	#endif /* COMMENT */
	1045	if (spsiz < 20) spsiz = 20;
	1046	debug(F101,"input N cut packet length","",spsiz);
	1047	}
	1048	}
	1049	#endif /* NEWDPL */
	1050	freerpkt(rsn); /* Free buffer where NAK lies. */
[20080]	1051	if (y == 0) { /* In current window */
[10779]	1052	debug(F100," in window","",0);
	1053	k = sseqtbl[rsn]; /* Get pointer to NAK'd packet. */
	1054	if (k < 0 \|\| (k > -1 && s_pkt[k].pk_typ == ' ')) {
	1055	x = resend(winlo); /* Packet we haven't sent yet. */
	1056	} else {
	1057	x = resend(rsn); /* Resend requested packet. */
	1058	}
	1059	if (x < 0) { /* Resend error is fatal. */
	1060	type = 'E';
[20080]	1061	errpkt((CHAR *)"Too many retries");
[10779]	1062	break;
	1063	} else continue; /* Resend ok, go read another packet */
	1064	} else if ((rsn == (pktnum + 1) % 64)) { /* NAK for next pkt */
	1065	if (wslots > 1) {
	1066	debug( F101,"NAK for next packet, windowing","",rsn);
	1067	x = resend(winlo); /* Resend window-low */
	1068	if (x < 0) {
	1069	type = 'E';
[20080]	1070	errpkt((CHAR *)"Too many retries");
[10779]	1071	break;
	1072	}
	1073	continue; /* Go back and read another pkt */
	1074	}
	1075	debug(F101,"NAK for next packet, no windowing","",rsn);
	1076	x = (rsn == 0) ? 63 : rsn - 1;
	1077	if (x == 0 && (sndtyp == 'S' \|\| sndtyp == 'I')) {
	1078	resend(0); /* ACK for S or I packet missing */
	1079	continue; /* so resend the S or I */
[20080]	1080	}
[10779]	1081	rsn = x; /* Else, treat NAK(n+1) as ACK(n) */
	1082	nak2ack = 1; /* Go back and process the ACK */
	1083	continue;
	1084	} else if (y > 0) { /* NAK for pkt we can't resend */
	1085	debug(F101," NAK out of window","",rsn); /* bad... */
	1086	type = 'E';
	1087	errpkt((CHAR *)"NAK out of window");
	1088	break;
	1089	} else continue; /* Ignore other NAKs */
	1090	} /* End of file-sender NAK handler */
	1091
	1092	if (rsn == winlo) { /* Not ACK, NAK, timeout, etc. */
	1093	debug(F000,"input send unexpected type","",type);
	1094	break;
	1095	}
	1096	} /* End of file-sender section */
	1097	} /* End of input() while() loop */
[20080]	1098	/*
	1099	When the window size is 1 and we have the packet we want, there can not
	1100	possibly be anything waiting for us on the connection that is useful to us.
	1101	However, there might be redundant copies of a packet we already got, which
	1102	would cause needless cycles of repeated packets. Therefore we flush the
	1103	communications input buffer now to try to get rid of undesired and unneeded
	1104	packets that we have not read yet.
	1105	*/
	1106	if (wslotn == 1 /* (not wslots!) */
	1107	#ifdef STREAMING
	1108	&& !streaming /* But not when streaming */
	1109	#endif /* STREAMING */
	1110	) {
[10779]	1111	debug(F100,"input about to flush","",0);
	1112	ttflui(); /* Got what we want, clear input buffer. */
	1113	}
	1114	#ifndef NEWDPL
[20080]	1115	if (!nakstate) /* When sending */
	1116	rcalcpsz(); /* recalculate size every packet */
[10779]	1117	#endif /* NEWDPL */
[20080]	1118	if (type == 'E')
	1119	xitsta \|= (what ? what : 1); /* Remember what failed. */
	1120	debug(F101,"input winlo","",winlo);
	1121	debug(F101,"input rsn","",rsn);
[10779]	1122	debug(F000,"input returning type","",type);
[20080]	1123	return(rcvtyp = type); /* Success, return packet type. */
[10779]	1124	}
	1125
	1126	#ifdef PARSENSE
	1127	/* P A R C H K -- Check if Kermit packet has parity */
	1128
	1129	/*
	1130	Call with s = pointer to packet, start = packet start character, n = length.
	1131	Returns 0 if packet has no parity, -1 on error, or, if packet has parity:
	1132	'e' for even, 'o' for odd, 'm' for mark. Space parity cannot be sensed.
	1133	So a return value of 0 really means either space or none.
	1134	Returns -2 if parity has already been checked during this protocol operation.
	1135	*/
	1136	int
	1137	#ifdef CK_ANSIC
	1138	parchk(CHAR *s, CHAR start, int n)
	1139	#else
	1140	parchk(s,start,n) CHAR *s, start; int n;
	1141	#endif /* CK_ANSIC */
	1142	/* parchk */ {
	1143	CHAR s0, s1, s2, s3;
	1144
	1145	debug(F101,"parchk n","",n);
	1146	debug(F101,"parchk start","",start);
	1147
	1148	s0 = s[0] & 0x7f; /* Mark field (usually Ctrl-A) */
	1149
	1150	if (s0 != start \|\| n < 5) return(-1); /* Not a valid packet */
	1151
	1152	/* Look at packet control fields, which never have 8th bit set */
	1153	/* First check for no parity, most common case. */
	1154
	1155	if (((s[0] \| s[1] \| s[2] \| s[3]) & 0x80) == 0)
	1156	return(0); /* No parity or space parity */
	1157
	1158	/* Check for mark parity */
	1159
	1160	if (((s[0] & s[1] & s[2] & s[3]) & 0x80) == 0x80)
	1161	return('m'); /* Mark parity */
	1162
	1163	/* Packet has some kind of parity */
	1164	/* Make 7-bit copies of control fields */
	1165
	1166	s1 = s[1] & 0x7f; /* LEN */
	1167	s2 = s[2] & 0x7f; /* SEQ */
	1168	s3 = s[3] & 0x7f; /* TYPE */
	1169
	1170	/* Check for even parity */
	1171
	1172	if ((s[0] == p_tbl[s0]) &&
	1173	(s[1] == p_tbl[s1]) &&
	1174	(s[2] == p_tbl[s2]) &&
	1175	(s[3] == p_tbl[s3]))
	1176	return('e');
	1177
	1178	/* Check for odd parity */
	1179
	1180	if ((s[0] != p_tbl[s0]) &&
	1181	(s[1] != p_tbl[s1]) &&
	1182	(s[2] != p_tbl[s2]) &&
	1183	(s[3] != p_tbl[s3]))
	1184	return('o');
	1185
	1186	/* Otherwise it's probably line noise. Let checksum calculation catch it. */
	1187
	1188	return(-1);
	1189	}
	1190	#endif /* PARSENSE */
	1191
	1192	/*
	1193	Check to make sure timeout intervals are long enough to allow maximum
	1194	length packets to get through before the timer goes off. If not, the
	1195	timeout interval is adjusted upwards.
	1196
	1197	This routine is called at the beginning of a transaction, before we
	1198	know anything about the delay characteristics of the line. It works
	1199	only for serial communication devices; it trusts the speed reported by
	1200	the operating system.
	1201
	1202	Call with a timout interval. Returns it, adjusted if necessary.
[20080]	1203	*/
[10779]	1204	int
	1205	chktimo(timo,flag) int timo, flag; {
	1206	long cps, z; int x, y;
[20080]	1207	#ifdef STREAMING
	1208	debug(F101,"chktimo streaming","",streaming);
	1209	if (streaming)
	1210	return(0);
	1211	#endif /* STREAMING */
	1212
[10779]	1213	debug(F101,"chktimo timo","",timo); /* Timeout before adjustment */
	1214	debug(F101,"chktimo flag","",flag);
	1215
	1216	if (flag) /* Don't change timeout if user */
	1217	return(timo); /* gave SET SEND TIMEOUT command. */
	1218	debug(F101,"chktimo spmax","",spmax);
	1219	debug(F101,"chktimo urpsiz","",urpsiz);
	1220
[20080]	1221	if (!network) { /* On serial connections... */
	1222	speed = ttgspd(); /* Get current speed. */
	1223	if (speed > 0L) {
	1224	cps = speed / 10L; /* Convert to chars per second */
	1225	if (cps > 0L) {
	1226	long plen; /* Maximum of send and rcv pkt size */
	1227	z = cps * (long) timo; /* Chars per timeout interval */
	1228	z -= z / 10L; /* Less 10 percent */
	1229	plen = spmax;
	1230	if (urpsiz > spmax) plen = urpsiz;
	1231	debug(F101,"chktimo plen","",plen);
	1232	if (z < plen) { /* Compare with packet size */
	1233	x = (int) ((long) plen / cps); /* Adjust if necessary */
	1234	y = x / 10; /* Add 10 percent for safety */
	1235	if (y < 2) y = 2; /* Or 2 seconds, whichever is more */
	1236	x += y;
	1237	if (x > timo) /* If this is greater than current */
	1238	timo = x; /* timeout, change the timeout */
	1239	debug(F101,"chktimo new timo","",timo);
	1240	}
[10779]	1241	}
	1242	}
	1243	}
	1244	return(timo);
	1245	}
	1246
	1247	/* S P A C K -- Construct and send a packet */
	1248
	1249	/*
	1250	spack() sends a packet of the given type, sequence number n, with len data
	1251	characters pointed to by d, in either a regular or extended- length packet,
	1252	depending on len. Returns the number of bytes actually sent, or else -1
[20080]	1253	upon failure. Uses global npad, padch, mystch, bctu, data. Leaves packet
[10779]	1254	fully built and null-terminated for later retransmission by resend().
	1255	Updates global sndpktl (send-packet length).
	1256
	1257	NOTE: The global pointer "data" is assumed to point into the 7th position
	1258	of a character array (presumably in packet buffer for the current packet).
	1259	It was used by getpkt() to build the packet data field. spack() fills in
	1260	the header to the left of the data pointer (the data pointer is defined
	1261	in getsbuf() in ckcfn3.c). If the address "d" is the same as "data", then
	1262	the packet's data field has been built "in place" and need not be copied.
	1263	*/
	1264	int
	1265	#ifdef CK_ANSIC
	1266	spack(char pkttyp, int n, int len, CHAR *d)
	1267	#else
	1268	spack(pkttyp,n,len,d) char pkttyp; int n, len; CHAR *d;
	1269	#endif /* CK_ANSIC */
	1270	/* spack */ {
	1271	register int i;
[20080]	1272	int ix, j, k, x, lp, longpkt, copy, loglen;
[10779]	1273
[20080]	1274	#ifdef GFTIMER
	1275	CKFLOAT t1 = 0.0, t2 = 0.0;
	1276	#endif /* GFTIMER */
[10779]	1277
	1278	register CHAR cp, mydata;
	1279	unsigned crc;
	1280
[20080]	1281	copy = (d != data); /* Flag whether data must be copied */
[10779]	1282
[20080]	1283	#ifdef DEBUG
	1284	if (deblog) { /* Save lots of function calls! */
	1285	debug(F101,"spack n","",n);
	1286	if (pkttyp != 'D') { /* Data packets would be too long */
	1287	debug(F111,"spack data",data,data);
	1288	debug(F111,"spack d",d,d);
	1289	}
	1290	debug(F101,"spack len","",len);
	1291	debug(F101,"spack copy","",copy);
	1292	}
	1293	#endif /* DEBUG */
	1294
[10779]	1295	longpkt = (len + bctl + 2) > 94; /* Decide whether it's a long packet */
	1296	mydata = data - 7 + (longpkt ? 0 : 3); /* Starting position of header */
[20080]	1297	k = sseqtbl[n]; /* Packet structure info for pkt n */
	1298	#ifdef DEBUG
	1299	if (deblog) { /* Save 2 more function calls... */
	1300	debug(F101,"spack mydata","",mydata);
	1301	debug(F101,"spack sseqtbl[n]","",k);
	1302	if (k < 0) {
	1303	#ifdef STREAMING
	1304	if (!streaming)
	1305	#endif /* STREAMING */
	1306	debug(F101,"spack sending packet out of window","",n);
	1307	}
	1308	}
	1309	#endif /* DEBUG */
	1310	if (k > -1) {
[10779]	1311	s_pkt[k].pk_adr = mydata; /* Remember address of packet. */
	1312	s_pkt[k].pk_seq = n; /* Record sequence number */
	1313	s_pkt[k].pk_typ = pkttyp; /* Record packet type */
	1314	}
	1315	spktl = 0; /* Initialize length of this packet */
	1316	i = 0; /* and position in packet. */
	1317
	1318	/* Now fill the packet */
	1319
	1320	mydata[i++] = mystch; /* MARK */
	1321	lp = i++; /* Position of LEN, fill in later */
	1322
	1323	mydata[i++] = tochar(n); /* SEQ field */
	1324	mydata[i++] = pkttyp; /* TYPE field */
	1325	j = len + bctl; /* Length of data + block check */
	1326	if (longpkt) { /* Long packet? */
[20080]	1327	int x; /* Yes, work around SCO Xenix/286 */
	1328	#ifdef CKTUNING
	1329	unsigned int chk;
	1330	#endif /* CKTUNING */
[10779]	1331	x = j / 95; /* compiler bug... */
[20080]	1332	mydata[lp] = tochar(0); /* Set LEN to zero */
	1333	mydata[i++] = tochar(x); /* Extended length, high byte */
	1334	mydata[i++] = tochar(j % 95); /* Extended length, low byte */
	1335	#ifdef CKTUNING
	1336	/* Header checksum - skip the function calls and loops */
	1337	chk = (unsigned) mydata[lp] +
	1338	(unsigned) mydata[lp+1] +
	1339	(unsigned) mydata[lp+2] +
	1340	(unsigned) mydata[lp+3] +
	1341	(unsigned) mydata[lp+4] ;
	1342	mydata[i++] = tochar((CHAR) ((((chk & 0300) >> 6) + chk) & 077));
	1343	#else
	1344	mydata[i] = '\0'; /* Terminate for header checksum */
	1345	mydata[i++] = tochar(chk1(mydata+lp,5));
	1346	#endif /* CKTUNING */
[10779]	1347	} else mydata[lp] = tochar(j+2); /* Normal LEN */
[20080]	1348	/*
	1349	When sending a file, the data is already in the right place. If it weren't,
	1350	it might make sense to optimize this section by using memcpy or bcopy
	1351	(neither of which are portable), but only if our packets were rather long.
	1352	When receiving, we're only sending ACKs so it doesn't matter. So count the
	1353	following loop as a sleeping dog.
	1354	*/
[10779]	1355	if (copy) /* Data field built in place? */
	1356	for ( ; len--; i++) mydata[i] = d++; / No, must copy. */
	1357	else /* Otherwise, */
	1358	i += len; /* Just skip past data field. */
	1359	mydata[i] = '\0'; /* Null-terminate for checksum calc. */
	1360
	1361	switch (bctu) { /* Block check */
[20080]	1362	case 1: /* 1 = 6-bit chksum */
	1363	ix = i - lp; /* Avoid "order of operation" error */
	1364	mydata[i++] = tochar(chk1(mydata+lp,ix));
[10779]	1365	break;
	1366	case 2: /* 2 = 12-bit chksum */
[20080]	1367	j = chk2(mydata+lp,i-lp);
[10779]	1368	mydata[i++] = (unsigned)tochar((j >> 6) & 077);
	1369	mydata[i++] = (unsigned)tochar(j & 077);
	1370	break;
	1371	case 3: /* 3 = 16-bit CRC */
[20080]	1372	crc = chk3(mydata+lp,i-lp);
[10779]	1373	mydata[i++] = (unsigned)tochar(((crc & 0170000)) >> 12);
	1374	mydata[i++] = (unsigned)tochar((crc >> 6) & 077);
	1375	mydata[i++] = (unsigned)tochar(crc & 077);
	1376	break;
	1377	case 4: /* 2 = 12-bit chksum, blank-free */
[20080]	1378	j = chk2(mydata+lp,i-lp);
[10779]	1379	mydata[i++] =
	1380	(unsigned)(tochar((unsigned)(((j >> 6) & 077) + 1)));
	1381	mydata[i++] = (unsigned)(tochar((unsigned)((j & 077) + 1)));
	1382	break;
	1383	}
[20080]	1384	loglen = i;
[10779]	1385	mydata[i++] = seol; /* End of line (packet terminator) */
	1386	#ifdef TCPSOCKET
	1387	/*
	1388	If TELNET connection and packet terminator is carriage return,
	1389	we must stuff either LF or NUL, according to SET TELNET NEWLINE-MODE
[20080]	1390	(tn_nlm), to meet the TELNET NVT specification, unless user said RAW.
[10779]	1391
	1392	If NEWLINE-MODE is set to LF instead of CR, we still send CR-NUL
	1393	on a NVT connection and CR on a binary connection.
	1394	*/
[20080]	1395	if (
	1396	#ifdef STREAMING
	1397	!dontsend &&
	1398	#endif /* STREAMING */
	1399	((network && ttnproto == NP_TELNET) \|\| (!local && sstelnet))
	1400	&& seol == CR) {
	1401	switch (TELOPT_ME(TELOPT_BINARY) ? tn_b_nlm : tn_nlm) {
	1402	case TNL_CR: /* NVT or BINARY */
	1403	break;
	1404	case TNL_CRNUL:
	1405	mydata[i++] = NUL;
	1406	break;
	1407	case TNL_CRLF:
	1408	mydata[i++] = LF;
	1409	break;
	1410	}
	1411	}
[10779]	1412	#endif /* TCPSOCKET */
	1413	mydata[i] = '\0'; /* Terminate string */
[20080]	1414	if (
	1415	#ifdef STREAMING
	1416	!dontsend &&
	1417	#endif /* STREAMING */
	1418	pktlog
	1419	) /* Save a function call! */
	1420	logpkt('s',n,mydata,loglen); /* Log the packet */
[10779]	1421
	1422	/* (PWP) add the parity quickly at the end */
[20080]	1423	if (parity) {
	1424	switch (parity) {
	1425	case 'e': /* Even */
	1426	for (cp = &mydata[i-1]; cp >= mydata; cp--)
	1427	cp = p_tbl[cp];
	1428	break;
	1429	case 'm': /* Mark */
	1430	for (cp = &mydata[i-1]; cp >= mydata; cp--)
	1431	*cp \|= 128;
	1432	break;
	1433	case 'o': /* Odd */
	1434	for (cp = &mydata[i-1]; cp >= mydata; cp--)
	1435	cp = p_tbl[cp] ^ 128;
	1436	break;
	1437	case 's': /* Space */
	1438	for (cp = &mydata[i-1]; cp >= mydata; cp--)
	1439	*cp &= 127;
	1440	break;
	1441	}
[10779]	1442	}
	1443	if (pktpaus) msleep(pktpaus); /* Pause if requested */
[20080]	1444	x = 0;
	1445
	1446	if (npad) {
	1447	#ifdef STREAMING
	1448	if (dontsend)
	1449	x = 0;
	1450	else
	1451	#endif /* STREAMING */
	1452	x = ttol(padbuf,npad); /* Send any padding */
	1453	}
	1454	if (x > -1) {
[10779]	1455	#ifdef CK_TIMERS
[20080]	1456	if (timint > 0) {
	1457	if (pkttyp == 'N')
	1458	srttbl[n > 0 ? n-1 : 63] = gtimer();
	1459	else
	1460	srttbl[n] = gtimer();
	1461	}
[10779]	1462	#endif /* CK_TIMERS */
[20080]	1463	spktl = i; /* Remember packet length */
	1464	if (k > -1)
	1465	s_pkt[k].pk_len = spktl; /* also in packet info structure */
[10779]	1466
[20080]	1467	#ifdef DEBUG
	1468	#ifdef GFTIMER
	1469	/*
	1470	This code shows (in the debug log) how long it takes write() to execute.
	1471	Sometimes on a congested TCP connection, it can surprise you -- 90 seconds
	1472	or more...
	1473	*/
	1474	if (
	1475	#ifdef STREAMING
	1476	!dontsend &&
	1477	#endif /* STREAMING */
	1478	deblog
	1479	)
	1480	t1 = gftimer();
	1481	#endif /* GFTIMER */
	1482	#endif /* DEBUG */
[10779]	1483
[20080]	1484	#ifdef STREAMING
	1485	if (dontsend) {
	1486	debug(F000,"STREAMING spack skipping","",pkttyp);
	1487	x = 0;
	1488	} else
	1489	#endif /* STREAMING */
	1490	x = ttol(mydata,spktl); /* Send the packet */
[10779]	1491	}
[20080]	1492	#ifdef STREAMING
	1493	if (!dontsend) {
	1494	#endif /* STREAMING */
	1495	debug(F101,"spack spktl","",spktl);
	1496	debug(F101,"spack ttol returns","",x);
	1497	if (x < 0) { /* Failed. */
	1498	if (local && x < -1) {
	1499	xxscreen(SCR_ST,ST_ERR,0L,"FAILED: Connection lost");
	1500	/* We can't send an E packet because the connection is lost. */
	1501	epktsent = 1; /* So pretend we sent one. */
	1502	fatalio = 1; /* Remember we got a fatal i/o error */
	1503	dologend();
	1504	ckstrncpy((char *)epktmsg,"Connection lost",PKTMSGLEN);
	1505	}
	1506	return(x);
	1507	}
	1508	if (spktl > maxsend) /* Keep track of longest packet sent */
	1509	maxsend = spktl;
	1510	#ifdef DEBUG
	1511	#ifdef GFTIMER
	1512	if (deblog) { /* Log elapsed time for write() */
	1513	t2 = gftimer();
	1514	debug(F101,"spack ttol msec","",(long)((t2-t1)*1000.0));
	1515	}
	1516	#endif /* GFTIMER */
	1517	#endif /* DEBUG */
	1518	#ifdef STREAMING
	1519	}
	1520	#endif /* STREAMING */
[10779]	1521
	1522	sndtyp = pkttyp; /* Remember packet type for echos */
[20080]	1523	#ifdef STREAMING
	1524	if (!dontsend) { /* If really sent, */
	1525	spackets++; /* count it. */
	1526	flco += spktl; /* Count the characters */
	1527	tlco += spktl; /* for statistics... */
	1528	#ifdef DEBUG
	1529	if (deblog) { /* Save two function calls! */
	1530	dumpsbuf(); /* Dump send buffers to debug log */
	1531	debug(F111,"spack calling screen, mydata=",mydata,n);
	1532	}
	1533	#endif /* DEBUG */
	1534	}
	1535	#endif /* STREAMING */
	1536	if (local) {
	1537	int x = 0;
	1538	if (fdispla != XYFD_N) x = 1;
	1539	if ((fdispla == XYFD_B) && (pkttyp == 'D' \|\| pkttyp == 'Y')) x = 0;
	1540	if (x)
	1541	xxscreen(SCR_PT,pkttyp,(long)n,(char )mydata); / Update screen */
	1542	}
[10779]	1543	return(spktl); /* Return length */
	1544	}
[20080]	1545
[10779]	1546	/* C H K 1 -- Compute a type-1 Kermit 6-bit checksum. */
	1547
	1548	int
[20080]	1549	chk1(pkt,len) register CHAR *pkt; register int len; {
[10779]	1550	register unsigned int chk;
[20080]	1551	#ifdef CKTUNING
	1552	#ifdef COMMENT
	1553	register unsigned int m; /* Avoid function call */
	1554	m = (parity) ? 0177 : 0377;
	1555	for (chk = 0; len-- > 0; pkt++)
	1556	chk += *pkt & m;
	1557	#else
	1558	chk = 0;
	1559	while (len-- > 0) chk += (unsigned) *pkt++;
	1560	#endif /* COMMENT */
	1561	#else
	1562	chk = chk2(pkt,len);
	1563	#endif /* CKTUNING */
[10779]	1564	chk = (((chk & 0300) >> 6) + chk) & 077;
[20080]	1565	debug(F101,"chk1","",chk);
[10779]	1566	return((int) chk);
	1567	}
	1568
	1569	/* C H K 2 -- Compute the numeric sum of all the bytes in the packet. */
	1570
	1571	unsigned int
[20080]	1572	chk2(pkt,len) register CHAR *pkt; register int len; {
	1573	register long chk;
	1574	#ifdef COMMENT
	1575	register unsigned int m;
[10779]	1576	m = (parity) ? 0177 : 0377;
[20080]	1577	for (chk = 0; len-- > 0; pkt++)
[10779]	1578	chk += *pkt & m;
[20080]	1579	#else
	1580	/* Parity has already been stripped */
	1581	chk = 0L;
	1582	while (len-- > 0) chk += (unsigned) *pkt++;
	1583	#endif /* COMMENT */
	1584	debug(F101,"chk2","",(unsigned int) (chk & 07777));
[10779]	1585	return((unsigned int) (chk & 07777));
	1586	}
	1587
	1588	/* C H K 3 -- Compute a type-3 Kermit block check. */
	1589	/*
[20080]	1590	Calculate the 16-bit CRC-CCITT of a null-terminated string using a lookup
[10779]	1591	table. Assumes the argument string contains no embedded nulls.
	1592	*/
[20080]	1593	#ifdef COMMENT
[10779]	1594	unsigned int
[20080]	1595	chk3(pkt,parity,len) register CHAR *pkt; int parity; register int len; {
[10779]	1596	register long c, crc;
	1597	register unsigned int m;
	1598	m = (parity) ? 0177 : 0377;
[20080]	1599	for (crc = 0; len-- > 0; pkt++) {
[10779]	1600	c = crc ^ (long)(*pkt & m);
	1601	crc = (crc >> 8) ^ (crcta[(c & 0xF0) >> 4] ^ crctb[c & 0x0F]);
	1602	}
	1603	return((unsigned int) (crc & 0xFFFF));
	1604	}
[20080]	1605	#else
	1606	unsigned int
	1607	chk3(pkt,len) register CHAR *pkt; register int len; {
	1608	register long c, crc;
	1609	for (crc = 0; len-- > 0; pkt++) {
	1610	c = crc ^ (long)(*pkt);
	1611	crc = (crc >> 8) ^ (crcta[(c & 0xF0) >> 4] ^ crctb[c & 0x0F]);
	1612	}
	1613	debug(F101,"chk3","",(unsigned int) (crc & 0xFFFF));
	1614	return((unsigned int) (crc & 0xFFFF));
	1615	}
	1616	#endif /* COMMENT */
[10779]	1617
[20080]	1618	/* N X T P K T -- Next Packet */
	1619	/*
	1620	Get packet number of next packet to send and allocate a buffer for it.
	1621	Returns:
	1622	0 on success, with global pktnum set to the packet number;
	1623	-1 on failure to allocate buffer (fatal);
	1624	-2 if resulting packet number is outside the current window.
	1625	*/
[10779]	1626	int
	1627	nxtpkt() { /* Called by file sender */
[20080]	1628	int j, n, x;
[10779]	1629
	1630	debug(F101,"nxtpkt pktnum","",pktnum);
	1631	debug(F101,"nxtpkt winlo ","",winlo);
	1632	n = (pktnum + 1) % 64; /* Increment packet number mod 64 */
[20080]	1633	debug(F101,"nxtpkt n","",n);
	1634	#ifdef STREAMING
	1635	if (!streaming) {
	1636	x = chkwin(n,winlo,wslots); /* Don't exceed window boundary */
	1637	debug(F101,"nxtpkt chkwin","",x);
	1638	if (x)
	1639	return(-2);
	1640	j = getsbuf(n); /* Get a buffer for packet n */
	1641	if (j < 0) {
	1642	debug(F101,"nxtpkt getsbuf failure","",j);
	1643	return(-1);
	1644	}
[10779]	1645	}
[20080]	1646	#endif /* STREAMING */
	1647	pktnum = n;
[10779]	1648	return(0);
	1649	}
	1650
	1651	/* Functions for sending ACKs and NAKs */
	1652
	1653	/* Note, we should only ACK the packet at window-low (winlo) */
	1654	/* However, if an old packet arrives again (e.g. because the ACK we sent */
	1655	/* earlier was lost), we ACK it again. */
	1656
	1657	int
	1658	ack() { /* Acknowledge the current packet. */
	1659	return(ackns(winlo,(CHAR *)""));
	1660	}
	1661
[20080]	1662	#ifdef STREAMING
[10779]	1663	int
[20080]	1664	fastack() { /* Acknowledge packet n */
	1665	int j, k, n, x;
	1666	n = winlo;
	1667
	1668	k = rseqtbl[n]; /* First find received packet n. */
	1669	debug(F101,"STREAMING fastack k","",k);
	1670	freesbuf(n); /* Free current send-buffer, if any */
	1671	if ((j = getsbuf(n)) < 0) {
	1672	/* This can happen if we have to re-ACK an old packet that has */
	1673	/* already left the window. It does no harm. */
	1674	debug(F101,"STREAMING fastack can't getsbuf","",n);
	1675	}
	1676	dontsend = 1;
	1677	x = spack('Y',n,0,(CHAR )""); / Now send it (but not really) */
	1678	dontsend = 0;
	1679	if (x < 0) return(x);
	1680	debug(F101,"STREAMING fastack x","",x);
	1681	if (k > -1)
	1682	freerbuf(k); /* don't need it any more */
	1683	if (j > -1)
	1684	freesbuf(j); /* and don't need to keep ACK either */
	1685	winlo = (winlo + 1) % 64;
	1686	return(0);
	1687	}
	1688	#endif /* STREAMING */
	1689
	1690	int
[10779]	1691	ackns(n,s) int n; CHAR s; { / Acknowledge packet n */
[20080]	1692	int j, k, x;
[10779]	1693	debug(F111,"ackns",s,n);
	1694
	1695	k = rseqtbl[n]; /* First find received packet n. */
	1696	debug(F101,"ackns k","",k);
	1697	freesbuf(n); /* Free current send-buffer, if any */
	1698	if ((j = getsbuf(n)) < 0) {
	1699	/* This can happen if we have to re-ACK an old packet that has */
	1700	/* already left the window. It does no harm. */
	1701	debug(F101,"ackns can't getsbuf","",n);
	1702	}
[20080]	1703	x = spack('Y',n,(int)strlen((char )s),s); / Now send it. */
	1704	if (x < 0) return(x);
[10779]	1705	debug(F101,"ackns winlo","",winlo);
	1706	debug(F101,"ackns n","",n);
	1707	if (n == winlo) { /* If we're acking winlo */
	1708	if (k > -1)
	1709	freerbuf(k); /* don't need it any more */
	1710	if (j > -1)
	1711	freesbuf(j); /* and don't need to keep ACK either */
	1712	winlo = (winlo + 1) % 64;
	1713	}
	1714	return(0);
	1715	}
	1716
	1717	int
	1718	ackn(n) int n; { /* Send ACK for packet number n */
	1719	return(ackns(n,(CHAR *)""));
	1720	}
	1721
	1722	int
	1723	ack1(s) CHAR s; { / Send an ACK with data. */
[20080]	1724	if (!s) s = (CHAR *)"";
	1725	debug(F110,"ack1",(char *)s,0);
	1726	return(ackns(winlo,s));
[10779]	1727	}
	1728
	1729	/* N A C K -- Send a Negative ACKnowledgment. */
	1730	/*
	1731	Call with the packet number, n, to be NAK'd.
	1732	Returns -1 if that packet has been NAK'd too many times, otherwise 0.
	1733	Btw, it is not right to return 0 under error conditions. This is
	1734	done because the -1 code is used for cancelling the file transfer.
	1735	More work is needed here.
	1736	*/
	1737	int
	1738	nack(n) int n; {
[20080]	1739	int i, x;
[10779]	1740
	1741	if (n < 0 \|\| n > 63) {
	1742	debug(F101,"nack bad pkt num","",n);
	1743	return(0);
	1744	} else debug(F101,"nack","",n);
	1745	if ((i = sseqtbl[n]) < 0) { /* If necessary */
	1746	if (getsbuf(n) < 0) { /* get a buffer for this NAK */
	1747	debug(F101,"nack can't getsbuf","",n);
	1748	return(0);
	1749	} else i = sseqtbl[n]; /* New slot number */
	1750	}
[20080]	1751	if (maxtry > 0 && s_pkt[i].pk_rtr++ > maxtry) /* How many? */
[10779]	1752	return(-1); /* Too many... */
	1753
	1754	/* Note, don't free this buffer. Eventually an ACK will come, and that */
	1755	/* will set it free. If not, well, it's back to ground zero anyway... */
	1756
[20080]	1757	x = spack('N',n,0,(CHAR ) ""); / NAKs never have data. */
	1758	return(x);
[10779]	1759	}
	1760
	1761	#ifndef NEWDPL /* This routine no longer used */
	1762	/*
	1763	* (PWP) recalculate the optimal packet length in the face of errors.
[20080]	1764	* This is a modified version of the algorithm by John Chandler in Kermit/370,
[10779]	1765	* see "Dynamic Packet Size Control", Kermit News, V2 #1, June 1988.
	1766	*
	1767	* This implementation minimizes the total overhead equation, which is
	1768	*
	1769	* Total chars = file_chars + (header_len * num_packs)
	1770	* + (errors * (header_len + packet_len))
	1771	*
	1772	* Differentiate with respect to number of chars, solve for packet_len, get:
	1773	*
	1774	* packet_len = sqrt (file_chars * header_len / errors)
	1775	*/
	1776
	1777	/*
	1778	(FDC) New super-simple algorithm. If there was an error in the most recent
	1779	packet exchange, cut the send-packet size in half, down to a minimum of 20.
	1780	If there was no error, increase the size by 5/4, up to the maximum negotiated
	1781	length. Seems to be much more responsive than previous algorithm, which took
	1782	forever to recover the original packet length, and it also went crazy under
	1783	certain conditions.
	1784
	1785	Here's another idea for packet length resizing that keeps a history of the
	1786	last n packets. Push a 1 into the left end of an n-bit shift register if the
	1787	current packet is good, otherwise push a zero. The current n-bit value, w, of
	1788	this register is a weighted sum of the noise hits for the last n packets, with
	1789	the most recent weighing the most. The current packet length is some function
	1790	of w and the negotiated packet length, like:
	1791
	1792	(2^n - w) / (2^n) * (negotiated length)
	1793
	1794	If the present resizing method causes problems, think about this one a little
	1795	more.
	1796	*/
	1797	VOID
	1798	rcalcpsz() {
	1799
	1800	#ifdef COMMENT
	1801	/* Old way */
	1802	register long x, q;
	1803	if (numerrs == 0) return; /* bounds check just in case */
	1804
	1805	/* overhead on a data packet is npad+5+bctr, plus 3 if extended packet */
	1806	/* an ACK is 5+bctr */
	1807
	1808	/* first set x = per packet overhead */
	1809	if (wslots > 1) /* Sliding windows */
	1810	x = (long) (npad+5+bctr); /* packet only, don't count ack */
	1811	else /* Stop-n-wait */
	1812	x = (long) (npad+5+3+bctr+5+bctr); /* count packet and ack. */
	1813
	1814	/* then set x = packet length ** 2 */
	1815	x = x * ( ffc / (long) numerrs); /* careful of overflow */
[20080]	1816
[10779]	1817	/* calculate the long integer sqrt(x) quickly */
	1818	q = 500;
	1819	q = (q + x/q) >> 1;
	1820	q = (q + x/q) >> 1;
	1821	q = (q + x/q) >> 1;
	1822	q = (q + x/q) >> 1; /* should converge in about 4 steps */
	1823	if ((q > 94) && (q < 130)) /* break-even point for long packets */
	1824	q = 94;
	1825	if (q > spmax) q = spmax; /* maximum bounds */
	1826	if (q < 10) q = 10; /* minimum bounds */
	1827	spsiz = q; /* set new send packet size */
	1828	debug(F101,"rcalcpsiz","",q);
	1829	#else
	1830	/* New way */
	1831	debug(F101,"rcalcpsiz numerrs","",numerrs);
	1832	debug(F101,"rcalcpsiz spsiz","",spsiz);
	1833	if (spackets < 3) {
	1834	numerrs = 0;
	1835	return;
	1836	}
	1837	if (numerrs)
	1838	spsiz = spsiz / 2;
	1839	else
	1840	spsiz = (spsiz / 4) * 5;
	1841	if (spsiz < 20) spsiz = 20;
	1842	if (spsiz > spmax) spsiz = spmax;
	1843	debug(F101,"rcalcpsiz new spsiz","",spsiz);
	1844	numerrs = 0;
	1845	#endif /* COMMENT */
	1846	}
	1847	#endif /* NEWDPL */
	1848
	1849	/* R E S E N D -- Retransmit packet n. */
	1850
	1851	/*
	1852	Returns 0 or positive on success (the number of retries for packet n).
	1853	On failure, returns a negative number, and an error message is placed
	1854	in recpkt.
	1855	*/
	1856	int
	1857	resend(n) int n; { /* Send packet n again. */
	1858	int j, k, x;
[20080]	1859	#ifdef GFTIMER
	1860	CKFLOAT t1 = 0.0, t2 = 0.0;
	1861	#endif /* GFTIMER */
[10779]	1862
	1863	debug(F101,"resend seq","",n);
	1864
	1865	k = chkwin(n,winlo,wslots); /* See if packet in current window */
	1866	j = -1; /* Assume it's lost */
	1867	if (k == 0) j = sseqtbl[n]; /* See if we still have a copy of it */
	1868	if (k != 0 \|\| j < 0) { /* If not.... */
	1869	if (nakstate && k == 1) {
	1870	/*
	1871	Packet n is in the previous window and we are the file receiver.
[20080]	1872	We already sent the ACK and deallocated its buffer so we can't just
[10779]	1873	retransmit the ACK. Rather than give up, we try some tricks...
	1874	*/
	1875	if (n == 0 && spackets < 63 && myinit[0]) { /* ACK to Send-Init */
	1876	/*
	1877	If the packet number is 0, and we're at the beginning of a protocol
	1878	operation (spackets < 63), then we have to resend the ACK to an I or S
	1879	packet, complete with parameters in the data field. So we take a chance and
	1880	send a copy of the parameters in an ACK packet with block check type 1.
	1881	*/
	1882	int bctlsav; /* Temporary storage */
	1883	int bctusav;
	1884	bctlsav = bctl; /* Save current block check length */
	1885	bctusav = bctu; /* and type */
	1886	bctu = bctl = 1; /* Set block check to 1 */
[20080]	1887	x = spack('Y',0,(int)strlen((char )myinit),(CHAR )myinit);
	1888	if (x < 0) return(x);
	1889	logpkt('#',n,(CHAR )"<reconstructed>",0); / Log it */
[10779]	1890	bctu = bctusav; /* Restore block check type */
	1891	bctl = bctlsav; /* and length */
	1892
	1893	} else { /* Not the first packet */
	1894	/*
	1895	It's not the first packet of the protocol operation. It's some other packet
	1896	that we have already ACK'd and forgotten about. So we take a chance and
	1897	send an empty ACK using the current block-check type. Usually this will
	1898	work out OK (like when acking Data packets), and no great harm will be done
	1899	if it was some other kind of packet (F, etc). If we are requesting an
	1900	interruption of the file transfer, the flags are still set, so we'll catch
	1901	up on the next packet.
	1902	*/
[20080]	1903	x = spack('Y',n,0,(CHAR *) "");
	1904	if (x < 0) return(x);
[10779]	1905	}
	1906	retrans++;
[20080]	1907	xxscreen(SCR_PT,'%',(long)pktnum,"Retransmission");
[10779]	1908	return(0);
	1909	} else {
	1910	/*
	1911	Packet number is not in current or previous window. We seem to hit this
	1912	code occasionally at the beginning of a transaction, for apparently no good
	1913	reason. Let's just log it for debugging, send nothing, and try to proceed
	1914	with the protocol rather than killing it.
	1915	*/
[20080]	1916	debug(F101,"resend PKT NOT IN WINDOW","",n);
	1917	debug(F101,"resend k","",k);
[10779]	1918	return(0);
	1919	}
	1920	}
	1921
	1922	/* OK, it's in the window and it's not lost. */
	1923
	1924	debug(F101,"resend pktinfo index","",k);
	1925
[20080]	1926	if (maxtry > 0 && s_pkt[j].pk_rtr++ > maxtry) { /* Over retry limit */
	1927	xitsta \|= what;
[10779]	1928	return(-1);
	1929	}
[20080]	1930	debug(F101,"resend retry","",s_pkt[j].pk_rtr); /* OK so far */
[10779]	1931	dumpsbuf(); /* (debugging) */
	1932	if (s_pkt[j].pk_typ == ' ') { /* Incompletely formed packet */
	1933	if (nakstate) { /* (This shouldn't happen any more) */
	1934	nack(n);
	1935	retrans++;
[20080]	1936	xxscreen(SCR_PT,'%',(long)pktnum,"(resend)");
[10779]	1937	return(s_pkt[j].pk_rtr);
	1938	} else { /* No packet to resend! */
	1939	#ifdef COMMENT
	1940	/*
	1941	This happened (once) while sending a file with 2 window slots and typing
	1942	X to the sender to cancel the file. But since we're cancelling anyway,
	1943	there's no need to give a scary message.
	1944	*/
[20080]	1945	sprintf((char *)epktmsg,
	1946	"resend logic error: NPS, n=%d, j=%d.",n,j);
[10779]	1947	return(-2);
	1948	#else
	1949	/* Just ignore it. */
	1950	return(0);
	1951	#endif /* COMMENT */
	1952	}
	1953	}
[20080]	1954	#ifdef DEBUG
	1955	#ifdef GFTIMER
	1956	if (deblog) t1 = gftimer();
	1957	#endif /* GFTIMER */
	1958	#endif /* DEBUG */
[10779]	1959
	1960	/* Everything ok, send the packet */
	1961	#ifdef CK_TIMERS
[20080]	1962	if (timint > 0)
	1963	srttbl[n] = gtimer(); /* Update the timer */
[10779]	1964	#endif /* CK_TIMERS */
	1965	x = ttol(s_pkt[j].pk_adr,s_pkt[j].pk_len);
	1966
[20080]	1967	#ifdef DEBUG
	1968	#ifdef GFTIMER
[10779]	1969	if (deblog) {
[20080]	1970	t2 = gftimer();
	1971	debug(F101,"resend ttol msec","",(long)((t2-t1)*1000.0));
[10779]	1972	}
[20080]	1973	#endif /* GFTIMER */
	1974	#endif /* DEBUG */
[10779]	1975	debug(F101,"resend ttol returns","",x);
	1976
	1977	retrans++; /* Count a retransmission */
[20080]	1978	xxscreen(SCR_PT,'%',(long)pktnum,"(resend)"); /* Tell user about resend */
	1979	logpkt('S',n,s_pkt[j].pk_adr, s_pkt[j].pk_len); /* Log the resent packet */
[10779]	1980	return(s_pkt[j].pk_rtr); /* Return the number of retries. */
	1981	}
	1982
[20080]	1983	/* E R R P K T -- Send an Error Packet */
	1984
[10779]	1985	int
[20080]	1986	errpkt(reason) CHAR reason; { / ...containing the reason given */
	1987	extern int rtimo, state, justone;
[10779]	1988	int x, y;
[20080]	1989	czseen = 1; /* Also cancels batch */
	1990	state = 0; /* Reset protocol state */
	1991	debug(F110,"errpkt",reason,0);
	1992	tlog(F110,"Protocol Error:",(char *)reason,0L);
	1993	xxscreen(SCR_EM,0,0L,reason);
[10779]	1994	encstr(reason);
[20080]	1995	x = spack('E',pktnum,size,data);
	1996	ckstrncpy((char )epktmsg,(char )reason,PKTMSGLEN);
	1997	y = quiet; quiet = 1; epktsent = 1; /* Close files silently. */
[10779]	1998	clsif(); clsof(1);
[20080]	1999	quiet = y;
	2000	/*
	2001	I just sent an E-packet. I'm in local mode, I was receiving a file,
	2002	I'm not a server, and sliding windows are in use. Therefore, there are
	2003	likely to be a bunch of packets already "in the pipe" on their way to me
	2004	by the time the remote sender gets the E-packet. So the next time I
	2005	CONNECT or try to start another protocol operation, I am likely to become
	2006	terribly confused by torrents of incoming material. To prevent this,
	2007	the following code soaks up packets from the connection until there is an
	2008	error or timeout, without wasting too much time waiting.
	2009
	2010	Exactly the same problem occurs when I am in remote mode or if I am
	2011	in server mode with the justone flag set. In remote mode not only
	2012	does the packet data potentially get echo'd back to the sender which
	2013	is confusing to the user in CONNECT mode, but it also may result in the
	2014	host performing bizarre actions such as suspending the process if ^Z is
	2015	unprefixed, etc.
	2016
	2017	Furthermore, thousands of packets bytes in the data stream prevent the
	2018	client from being able to process Telnet Kermit Option negotiations
	2019	properly.
	2020	*/
	2021	#ifdef STREAMING
	2022	/* Because streaming sets the timeout to 0... */
	2023	if (streaming) {
	2024	timint = rcvtimo = rtimo;
	2025	streaming = 0;
	2026	}
	2027	#endif /* STREAMING */
	2028	if (what & W_RECV &&
	2029	(!server \|\| (server && justone)) &&
	2030	(wslots > 1
	2031	#ifdef STREAMING
	2032	\|\| streaming
	2033	#endif /* STREAMING */
	2034	)) {
	2035	#ifdef GFTIMER
	2036	CKFLOAT oldsec, sec = (CKFLOAT) 0.0;
	2037	#else
	2038	int oldsec, sec = 0;
	2039	#endif /* GFTIMER */
	2040	debug(F101,"errpkt draining","",wslots);
	2041	xxscreen(SCR_ST,ST_MSG,0l,"Draining incoming packets, wait...");
	2042	while (x > -1) { /* Don't bother if no connection */
	2043	oldsec = sec;
	2044	#ifdef GFTIMER
	2045	sec = gftimer();
	2046	if (oldsec != (CKFLOAT) 0.0)
	2047	timint = rcvtimo = (int) (sec - oldsec + 0.5);
	2048	#else
	2049	sec = gtimer();
	2050	if (oldsec != 0)
	2051	timint = rcvtimo = sec - oldsec + 1;
	2052	#endif /* GFTIMER */
	2053	if (timint < 1)
	2054	timint = rcvtimo = 1;
	2055	msleep(50); /* Allow a bit of slop */
	2056	x = rpack(); /* Read a packet */
	2057	if (x == 'T' \|\| x == 'z') /* Timed out means we're done */
	2058	break;
	2059	xxscreen(SCR_PT,x,rsn,""); /* Let user know */
	2060	}
	2061	xxscreen(SCR_ST,ST_MSG,0l,"Drain complete.");
	2062	}
	2063	if ((x = (what & W_KERMIT)))
	2064	xitsta \|= x; /* Remember what failed. */
[10779]	2065	success = 0;
	2066	return(y);
	2067	}
	2068
	2069	/* scmd() -- Send a packet of the given type */
	2070
	2071	int
	2072	#ifdef CK_ANSIC
	2073	scmd(char t, CHAR *dat)
	2074	#else
	2075	scmd(t,dat) char t; CHAR *dat;
	2076	#endif /* CK_ANSIC */
	2077	/* scmd */ {
[20080]	2078	int x;
	2079	extern char * srimsg;
	2080	debug(F000,"scmd",dat,t);
	2081	if (encstr(dat) < 0) { /* Encode the command string */
	2082	srimsg = "String too long";
	2083	return(-1);
	2084	}
	2085	x = spack(t,pktnum,size,data);
	2086	debug(F101,"scmd spack","",x);
	2087	return(x);
[10779]	2088	}
	2089
[20080]	2090	/* Compose and Send GET packet */
	2091
	2092	struct opktparm { /* O-Packet item list */
	2093	CHAR * opktitem;
	2094	struct opktparm * opktnext;
	2095	};
	2096
	2097	struct opktparm * opkthead = NULL; /* Linked list of O-packet fields */
	2098	int opktcnt = 0; /* O-Packet counter */
	2099	char * srimsg = NULL; /* GET-Packet error message */
	2100
	2101	/* S O P K T -- Send O-Packet */
	2102	/*
	2103	Sends one O-Packet each time called, using first-fit method of filling
	2104	the packet from linked list of parameters pointed to by opkthead.
	2105	To be called repeatedly until list is empty or there is an error.
	2106	Returns:
	2107	-1 on failure.
	2108	0 on success and no more fields left to send.
	2109	1 on success but with more fields left to be sent.
	2110	*/
	2111
[10779]	2112	int
[20080]	2113	sopkt() {
	2114	int n = 0; /* Field number in this packet */
	2115	int rc = 0; /* Return code */
	2116	int len = 0; /* Data field length */
	2117	char c = NUL;
	2118	struct opktparm * o = NULL;
	2119	struct opktparm * t = NULL;
	2120	struct opktparm * prev = NULL;
	2121	CHAR * dsave = data;
	2122	int x, ssave = spsiz;
	2123
	2124	srimsg = NULL; /* Error message */
	2125	o = opkthead; /* Point to head of list */
	2126	if (!o) { /* Oops, no list... */
	2127	srimsg = "GET Packet Internal Error 1";
	2128	debug(F100,"sopkt NULL list","",0);
	2129	return(-1);
	2130	}
	2131	while (o) { /* Go thru linked list... */
	2132	c = (o->opktitem); / Parameter code */
	2133	debug(F000,"sopkt",o->opktitem,c);
	2134	x = encstr((CHAR *)o->opktitem);
	2135	debug(F111,"sopkt encstr",dsave,x);
	2136	if (x < 0) { /* Encode this item */
	2137	if (n == 0) { /* Failure, first field in packet */
	2138	debug(F100,"sopkt overflow","",0);
	2139	spsiz = ssave; /* Restore these */
	2140	data = dsave;
	2141	o = opkthead; /* Free linked list */
	2142	while (o) {
	2143	if (o->opktitem) free(o->opktitem);
	2144	t = o->opktnext;
	2145	free((char *)o);
	2146	o = t;
	2147	}
	2148	opkthead = NULL;
	2149	srimsg = "GET Packet Too Long for Server";
	2150	return(-1); /* Fail */
	2151	} else { /* Not first field in packet */
	2152	debug(F110,"sopkt leftover",o->opktitem,0);
	2153	prev = o; /* Make this one the new previous */
	2154	o = o->opktnext; /* Get next */
	2155	c = NUL; /* So we know we're not done */
	2156	data = NUL; / Erase any partial encoding */
	2157	continue; /* We can try this one again later */
	2158	}
	2159	}
	2160	n++; /* Encoding was successful */
	2161	debug(F111,"sopkt field",data,x);
	2162	len += x; /* Total data field length */
	2163	data += x; /* Set up for next field... */
	2164	spsiz -= x;
	2165	free(o->opktitem); /* Free item just encoded */
	2166	if (o == opkthead) { /* If head */
	2167	opkthead = o->opktnext; /* Move head to next */
	2168	free((char )o); / Free this list node */
	2169	o = opkthead;
	2170	} else { /* If not head */
	2171	o = o->opktnext; /* Get next */
	2172	prev->opktnext = o; /* Link previous to next */
	2173	}
	2174	if (c == '@') /* Loop exit */
	2175	break;
	2176	if (!o && !opkthead) { /* Set up End Of Parameters Field */
	2177	o = (struct opktparm *)malloc(sizeof(struct opktparm));
	2178	if (o) {
	2179	opkthead = o;
	2180	if (!(o->opktitem = (CHAR *)malloc(3))) {
	2181	free((char *)o);
	2182	srimsg = "GET Packet Internal Error 8";
	2183	return(-1);
	2184	}
	2185	ckstrncpy((char *)(o->opktitem), "@ ", 3);
	2186	debug(F111,"sopkt o->opktitem",o->opktitem,
	2187	strlen((char *)(o->opktitem)));
	2188	o->opktnext = NULL;
	2189	}
	2190	}
	2191	}
	2192	data = dsave; /* Restore globals */
	2193	spsiz = ssave;
	2194	debug(F110,"sopkt data",data,0);
	2195	debug(F101,"sopkt opktcnt","",opktcnt);
	2196	if (opktcnt++ > 0) {
	2197	if (nxtpkt() < 0) { /* Get next packet number and buffer */
	2198	srimsg = "GET Packet Internal Error 9";
	2199	return(-1);
	2200	}
	2201	}
	2202	debug(F101,"sopkt pktnum","",pktnum);
	2203	rc = spack((char)'O',pktnum,len,data); /* Send O-Packet */
	2204	debug(F101,"sopkt spack","",rc);
	2205	if (rc < 0) /* Failed */
	2206	srimsg = "Send Packet Failure"; /* Set message */
	2207	else /* Succeeded */
	2208	rc = (c == '@') ? 0 : 1; /* 1 = come back for more, 0 = done */
	2209	debug(F101,"sopkt rc","",rc);
	2210	return(rc);
	2211	}
	2212
	2213	/* S R I N I T -- Send GET packet */
	2214	/*
	2215	Sends the appropriate GET-Class packet.
	2216	Returns:
	2217	-1 on error
	2218	0 if packet sent successfully and we can move on to the next state
	2219	1 if an O-packet was sent OK but more O packets still need to be sent.
	2220	*/
	2221	int
	2222	srinit(reget, retrieve, opkt) int reget, retrieve, opkt; {
	2223	int x = 0, left = 0;
	2224	extern int oopts, omode;
	2225	CHAR * p = NULL;
	2226	#ifdef RECURSIVE
	2227	extern int recursive;
	2228	debug(F101,"srinit recursive","",recursive);
	2229	#endif /* RECURSIVE */
	2230	debug(F101,"srinit reget","",reget);
	2231	debug(F101,"srinit retrieve","",retrieve);
	2232	debug(F101,"srinit opkt","",opkt);
	2233	debug(F101,"srinit oopts","",oopts);
	2234	debug(F101,"srinit omode","",omode);
	2235	debug(F110,"srinit cmarg",cmarg,0);
	2236	srimsg = NULL;
	2237
	2238	opktcnt = 0;
	2239	if (!cmarg) cmarg = "";
	2240	if (!*cmarg) {
	2241	srimsg = "GET with no filename";
	2242	debug(F100,"srinit null cmarg","",0);
	2243	return(-1);
	2244	}
	2245	if (opkt) { /* Extended GET is totally different */
	2246	char buf[16];
	2247	struct opktparm * o = NULL;
	2248	struct opktparm * prev = NULL;
	2249
	2250	buf[0] = NUL;
	2251
	2252	/* Build O-Packet fields and send (perhaps first) O-Packet */
	2253
	2254	if (oopts > -1) { /* Write Option flags */
	2255	o = (struct opktparm *)malloc(sizeof(struct opktparm));
	2256	if (!o) {
	2257	srimsg = "GET Packet Internal Error 2";
	2258	debug(F100,"srinit malloc fail O1","",0);
	2259	return(-1);
	2260	}
	2261	sprintf(buf,"Ox%d",oopts); /* safe */
	2262	x = (int) strlen(buf+2);
	2263	buf[1] = tochar(x);
	2264	o->opktitem = (CHAR *)malloc(x + 3);
	2265	if (!o->opktitem) {
	2266	srimsg = "GET Packet Internal Error 3";
	2267	debug(F100,"srinit malloc fail O2","",0);
	2268	return(-1);
	2269	}
	2270	ckstrncpy((char *)(o->opktitem),buf,x+3);
	2271	o->opktnext = NULL;
	2272	if (!opkthead)
	2273	opkthead = o;
	2274	prev = o;
	2275	}
	2276	if (omode > -1) { /* If Xfer Mode specified, write it */
	2277	o = (struct opktparm *)malloc(sizeof(struct opktparm));
	2278	if (!o) {
	2279	srimsg = "GET Packet Internal Error 4";
	2280	debug(F100,"srinit malloc fail M1","",0);
	2281	return(-1);
	2282	}
	2283	sprintf(buf,"Mx%d",omode); /* safe */
	2284	x = (int) strlen(buf+2);
	2285	buf[1] = tochar(x);
	2286	o->opktitem = (CHAR *)malloc(x + 3);
	2287	if (!o->opktitem) {
	2288	srimsg = "GET Packet Internal Error 5";
	2289	debug(F100,"srinit malloc fail O2","",0);
	2290	return(-1);
	2291	}
	2292	ckstrncpy((char *)(o->opktitem),buf,x+3);
	2293	o->opktnext = NULL;
	2294	if (!opkthead)
	2295	opkthead = o;
	2296	else
	2297	prev->opktnext = o;
	2298	prev = o;
	2299	}
	2300
	2301	/* Same deal for oname and opath eventually but not needed now... */
	2302
	2303	x = strlen(cmarg); /* Now do filename */
	2304	if (x > spsiz - 4) {
	2305	srimsg = "GET Packet Too Long for Server";
	2306	return(-1);
	2307	}
	2308	o = (struct opktparm *)malloc(sizeof(struct opktparm));
	2309	if (!o) {
	2310	srimsg = "GET Packet Internal Error 6";
	2311	debug(F100,"srinit malloc fail F1","",0);
	2312	return(-1);
	2313	}
	2314	left = x + 6;
	2315	o->opktitem = (CHAR *)malloc(left + 1);
	2316	if (!o->opktitem) {
	2317	srimsg = "GET Packet Internal Error 7";
	2318	debug(F100,"srinit malloc fail F2","",0);
	2319	return(-1);
	2320	}
	2321	p = o->opktitem;
	2322	*p++ = 'F';
	2323	left--;
	2324	if (x > 94) { /* Too long for normal length */
	2325	p++ = SYN; / Escape length with Ctrl-V */
	2326	*p++ = tochar(x / 95);
	2327	*p++ = tochar(x % 95);
	2328	left -= 3;
	2329	} else { /* Normal encoding for 94 or less */
	2330	*p++ = tochar(x);
	2331	left--;
	2332	}
	2333	ckstrncpy((char )p,cmarg,left); / Copy the filename */
	2334	o->opktnext = NULL;
	2335	if (!opkthead)
	2336	opkthead = o;
	2337	else
	2338	prev->opktnext = o;
	2339	prev = o;
	2340
	2341	/* End of Parameters */
	2342
	2343	prev->opktnext = NULL; /* End of list. */
	2344	return(sopkt());
	2345	}
	2346
	2347	/* Not Extended GET */
	2348
	2349	if (encstr((CHAR )cmarg) < 0) { / Encode the filename. */
	2350	srimsg = "GET Packet Too Long for Server";
	2351	return(-1);
	2352	}
	2353	if (retrieve) { /* Send the packet. */
	2354	#ifdef RECURSIVE
	2355	if (recursive)
	2356	x = spack((char)'W',pktnum,size,data); /* GET /DELETE /RECURSIVE */
	2357	else
	2358	#endif /* RECURSIVE */
	2359	x = spack((char)'H',pktnum,size,data); /* GET /DELETE */
	2360	}
	2361	#ifdef RECURSIVE
	2362	else if (recursive)
	2363	x = spack((char)'V',pktnum,size,data); /* GET /RECURSIVE */
	2364	#endif /* RECURSIVE */
[10779]	2365	else
[20080]	2366	x = spack((char)(reget ? 'J' : 'R'),pktnum,size,data); /* GET */
	2367	if (x < 0)
	2368	srimsg = "Send Packet Failure";
	2369	return(x < 0 ? x : 0);
[10779]	2370	}
	2371
[20080]	2372
[10779]	2373	/* K S T A R T -- Checks for a Kermit packet while in terminal mode. */
	2374
[20080]	2375	/* (or command mode...) */
	2376
	2377	#ifdef CK_AUTODL
	2378	int
[10779]	2379	#ifdef CK_ANSIC
	2380	kstart(CHAR ch)
	2381	#else
	2382	kstart(ch) CHAR ch;
	2383	#endif /* CK_ANSIC */
	2384	/* kstart */ {
	2385	static CHAR * p = NULL;
	2386
[20080]	2387	#ifdef OS2
	2388	static CHAR * pk = NULL;
	2389	#endif /* OS2 */
	2390	ch &= 0177; /* Strip 8th bit */
	2391
	2392	/* Because we're in cooked mode at the command prompt... */
	2393
	2394	if (ch == LF) {
	2395	debug(F110,"kstart","ch == LF",0);
	2396	if ((what == W_COMMAND \|\| what == W_INIT \|\| what == W_NOTHING)) {
	2397	if (eol == CR) {
	2398	ch = eol;
	2399	debug(F110,"kstart","ch = CR",0);
	2400	}
	2401	}
	2402	}
	2403
	2404	#ifdef OS2
	2405	if (adl_kmode == ADL_STR) {
	2406	if (!ch)
	2407	return(0);
	2408	if (!pk)
	2409	pk = adl_kstr;
	2410
	2411	if (ch == *pk) {
	2412	pk++;
	2413	if (*pk == '\0') {
	2414	pk = adl_kstr;
	2415	debug(F100, "kstart Kermit Start String","",0);
	2416	return(PROTO_K + 1);
	2417	}
	2418	} else
	2419	pk = adl_kstr;
	2420	}
	2421	#endif /* OS2 */
	2422
[10779]	2423	if (ch == stchr) { /* Start of packet */
[20080]	2424	kstartactive = 1;
	2425	p = ksbuf;
[10779]	2426	*p = ch;
	2427	debug(F101,"kstart SOP","",ch);
	2428	} else if (ch == eol) { /* End of packet */
[20080]	2429	kstartactive = 0;
[10779]	2430	if (p) {
[20080]	2431	debug(F101,"kstart EOL","",ch);
[10779]	2432	p++;
[20080]	2433	if (p - ksbuf < 94 ) {
[10779]	2434	int rc = 0;
[20080]	2435	*p++ = ch;
[10779]	2436	*p = NUL;
[20080]	2437	rc = chkspkt((char *)ksbuf);
	2438	debug(F111,"kstart EOP chkspkt", ksbuf, rc);
[10779]	2439	p = NULL;
	2440	if (!rc) return(0);
[20080]	2441	if (rc == 2) rc = -1;
	2442	debug(F111,"kstart ksbuf",ksbuf,rc);
	2443	return(rc);
[10779]	2444	} else {
[20080]	2445	debug(F110,"kstart","p - ksbuf >= 94",0);
[10779]	2446	p = NULL;
	2447	}
[20080]	2448	}
[10779]	2449	} else if (p) {
[20080]	2450	if (ch < SP)
	2451	kstartactive = 0;
[10779]	2452	p++;
[20080]	2453	if (p - ksbuf < 94) {
	2454	*p = ch;
	2455	} else {
	2456	p = NULL;
	2457	debug(F110,"kstart","p - ksbuf >= 94",0);
	2458	}
[10779]	2459	}
	2460	return(0);
	2461	}
	2462
	2463	#ifdef CK_XYZ
	2464
	2465	/* Z S T A R T -- Checks for a ZMODEM packet while in terminal mode. */
	2466
[20080]	2467	int
[10779]	2468	#ifdef CK_ANSIC
	2469	zstart(CHAR ch)
	2470	#else
	2471	zstart(ch) CHAR ch;
	2472	#endif /* CK_ANSIC */
	2473	/* zstart */ {
	2474	static CHAR * matchstr = (CHAR *) "\030B00";
	2475	/* "rz\r*\030B00000000000000\r\033J\021"; /
	2476	static CHAR * p = NULL;
[20080]	2477	extern int inserver;
[10779]	2478
[20080]	2479	if (inserver)
	2480	return(0);
	2481
[10779]	2482	if (!ch)
	2483	return(0);
[20080]	2484	if (!p) {
	2485	#ifdef OS2
	2486	p = adl_zmode == ADL_PACK ? matchstr : adl_zstr;
	2487	#else
	2488	p = matchstr;
	2489	#endif /* OS2 */
	2490	}
[10779]	2491	if (ch == *p) {
	2492	p++;
	2493	if (*p == '\0') {
[20080]	2494	#ifdef OS2
	2495	if (adl_zmode == ADL_PACK) {
	2496	p = matchstr;
	2497	debug(F100, "zstart Zmodem SOP","",0);
	2498	} else {
	2499	p = adl_zstr;
	2500	debug(F100, "zstart Zmodem Start String","",0);
	2501	}
	2502	#else
[10779]	2503	p = matchstr;
	2504	debug(F100, "zstart Zmodem SOP","",0);
[20080]	2505	#endif /* OS2 */
[10779]	2506	return(PROTO_Z + 1);
	2507	}
[20080]	2508	} else {
	2509	#ifdef OS2
	2510	p = adl_zmode == ADL_PACK ? matchstr : adl_zstr;
	2511	#else
	2512	p = matchstr;
	2513	#endif /* OS2 */
	2514	}
[10779]	2515	return(0);
	2516	}
	2517	#endif /* CK_XYZ */
	2518
[20080]	2519	#ifndef NOICP
	2520	#ifdef CK_APC
	2521	/* A U T O D O W N */
	2522
	2523	#ifdef CK_ANSIC
	2524	VOID
	2525	autodown(int ch)
	2526	#else
	2527	VOID
	2528	autodown(ch) int ch;
	2529	#endif /* CK_ANSIC */
	2530	/* autodown */ {
	2531
	2532	/* The Kermit and Zmodem Auto-download calls go here */
	2533
	2534	extern int justone; /* From protocol module */
	2535	extern int debses, protocol, apcactive, autodl, inautodl;
	2536	#ifdef DCMDBUF
	2537	extern char *apcbuf;
	2538	#else
	2539	extern char apcbuf[];
	2540	#endif /* DCMDBUF */
	2541	#ifdef OS2
	2542	extern int apclength, term_io;
	2543	#endif /* OS2 */
	2544	int k = 0;
	2545
	2546	if ((autodl \|\| inautodl
	2547	#ifdef IKS_OPTION
	2548	\|\| TELOPT_SB(TELOPT_KERMIT).kermit.me_start
	2549	#endif /* IKS_OPTION */
	2550	) && !debses) {
	2551	#ifdef CK_XYZ
	2552	#ifdef XYZ_INTERNAL
	2553	extern int p_avail;
	2554	#else
	2555	int p_avail = 1;
	2556	#endif /* XYZ_INTERNAL */
	2557	if (p_avail && zstart((CHAR) ch)) {
	2558	debug(F100, "Zmodem download","",0);
	2559	#ifdef OS2
	2560	#ifndef NOTERM
	2561	apc_command(APC_LOCAL,"receive /protocol:zmodem");
	2562	#endif /* NOTERM */
	2563	#else /* OS2 */
	2564	ckstrncpy(apcbuf,"receive /protocol:zmodem",APCBUFLEN);
	2565	apcactive = APC_LOCAL;
	2566	#endif /* OS2 */
	2567	return;
	2568	}
	2569	#endif /* CK_XYZ */
	2570
	2571	/* First try... */
	2572	k = kstart((CHAR) ch);
	2573	if (
	2574	#ifdef NOSERVER
	2575	k > 0
	2576	#else /* NOSERVER */
	2577	k
	2578	#endif /* NOSERVER */
	2579	) { /* We saw a valid S or I packet */
	2580	if (k < 0) { /* Stuff RECEIVE into APC buffer */
	2581	justone = 1;
	2582	switch (protocol) {
	2583	#ifdef CK_XYZ
	2584	case PROTO_G:
	2585	ckstrncpy(apcbuf,
	2586	"set proto kermit, server, set protocol g",
	2587	APCBUFLEN
	2588	);
	2589	break;
	2590	case PROTO_X:
	2591	ckstrncpy(apcbuf,
	2592	"set proto kermit,server,set proto xmodem",
	2593	APCBUFLEN
	2594	);
	2595	break;
	2596	case PROTO_XC:
	2597	ckstrncpy(apcbuf,
	2598	"set proto kermit,server,set proto xmodem-crc",
	2599	APCBUFLEN
	2600	);
	2601	break;
	2602	case PROTO_Y:
	2603	ckstrncpy(apcbuf,
	2604	"set proto kermit,server, set protocol y",
	2605	APCBUFLEN
	2606	);
	2607	break;
	2608	case PROTO_Z:
	2609	ckstrncpy(apcbuf,
	2610	"set proto kermit,server,set proto zmodem",
	2611	APCBUFLEN
	2612	);
	2613	break;
	2614	#endif /* CK_XYZ */
	2615	case PROTO_K:
	2616	ckstrncpy(apcbuf,"server",APCBUFLEN);
	2617	break;
	2618	}
	2619	} else {
	2620	justone = 0;
	2621	ckstrncpy(apcbuf,"receive /protocol:kermit",APCBUFLEN);
	2622	}
	2623	#ifdef OS2
	2624	#ifndef NOTERM
	2625	apc_command(APC_LOCAL,apcbuf);
	2626	#endif /* NOTERM */
	2627	#else /* OS2 */
	2628	ckstrncpy(apcbuf,"receive /protocol:zmodem",APCBUFLEN);
	2629	apcactive = APC_LOCAL;
	2630	#endif /* OS2 */
	2631	return;
	2632	}
	2633	}
	2634	}
	2635	#endif /* CK_APC */
	2636	#endif /* NOICP */
	2637
[10779]	2638	/* C H K S P K T -- Check if buf contains a valid S or I packet */
	2639
	2640	int
	2641	chkspkt(buf) char *buf; {
	2642	int buflen;
	2643	int len = -1;
	2644	CHAR chk;
	2645	char type = 0;
	2646	char *s = buf;
	2647
	2648	if (!buf) return(0);
	2649	buflen = strlen(buf);
	2650	if (buflen < 5) return(0); /* Too short */
	2651	if (s++ != stchr) return(0); / SOH */
	2652	len = xunchar(s++); / Length */
	2653	if (len < 0) return(0);
	2654	if (s++ != SP) return(0); / Sequence number */
	2655	type = s++; / Type */
	2656	if (type != 'S' && type != 'I')
	2657	return(0);
	2658	if (buflen < len + 2) return(0);
	2659	s += (len - 3); /* Position of checksum */
	2660	chk = (CHAR) (s); / Checksum */
	2661	*s = NUL;
[20080]	2662	if (xunchar(chk) != chk1((CHAR )(buf+1),buflen-2)) / Check it */
	2663	return(0);
[10779]	2664	*s = chk;
	2665	return(type == 'S' ? 1 : 2);
	2666	}
[20080]	2667	#endif /* CK_AUTODL */
[10779]	2668
	2669	/* R P A C K -- Read a Packet */
	2670
	2671	/*
[20080]	2672	rpack reads a packet and returns the packet type, or else Q if the
	2673	packet was invalid, or T if a timeout occurred. Upon successful return,
	2674	sets the values of global rsn (received sequence number), rln (received
	2675	data length), and rdatap (pointer to null-terminated data field), and
	2676	returns the packet type. NOTE: This is an inner-loop function so must be
	2677	efficient. Protect function calls by if-tests where possible, e.g.
	2678	"if (pktlog) logpkt(...);".
[10779]	2679	*/
	2680	int
	2681	rpack() {
	2682	register int i, j, x, lp; /* Local variables */
[20080]	2683	#ifdef CKTUNING
	2684	unsigned int chk;
	2685	#endif /* CKTUNING */
[10779]	2686	int k, type, chklen;
	2687	unsigned crc;
[20080]	2688	CHAR pbc[5]; /* Packet block check */
[10779]	2689	CHAR sohp; / Pointer to SOH */
	2690	CHAR e; /* Packet end character */
	2691
[20080]	2692	#ifdef GFTIMER
	2693	CKFLOAT t1 = 0.0, t2 = 0.0;
	2694	#endif /* GFTIMER */
[10779]	2695
[20080]	2696	debug(F101,"rpack pktnum","",pktnum);
[10779]	2697
	2698	#ifndef OLDCHKINT
	2699	if (chkint() < 0) /* Check for console interrupts. */
	2700	return('z');
	2701	#endif /* OLDCHKINT */
	2702
	2703	k = getrbuf(); /* Get a new packet input buffer. */
	2704	debug(F101,"rpack getrbuf","",k);
[20080]	2705	if (k < 0) { /* Return like this if none free. */
	2706	return(-1);
	2707	}
[10779]	2708	recpkt = r_pkt[k].bf_adr;
	2709	recpkt = '\0'; / Clear receive buffer. */
	2710	sohp = recpkt; /* Initialize pointers to it. */
	2711	rdatap = recpkt;
	2712	rsn = rln = -1; /* In case of failure. */
	2713	e = (turn) ? turnch : eol; /* Use any handshake char for eol */
	2714
	2715	/* Try to get a "line". */
	2716
[20080]	2717	#ifdef CK_AUTODL
	2718	debug(F110,"rpack ksbuf",ksbuf,0);
	2719	if (ksbuf[0]) { /* Kermit packet already */
	2720	int x; /* collected for us in CONNECT mode */
	2721	CHAR s1 = recpkt, s2 = ksbuf;
	2722	j = 0;
	2723	while (s2) { / Copy and get length */
	2724	s1++ = s2++; /* No point optimizing this since */
	2725	j++; /* it's never more than ~20 chars */
	2726	}
	2727	*s1 = NUL;
	2728	#ifdef PARSENSE
	2729	x = parchk(recpkt, stchr, j); /* Check parity */
	2730	debug(F000,"autodownload parity","",parity);
	2731	debug(F000,"autodownload parchk","",x);
	2732	if (x > -1 && parity != x) {
	2733	autopar = 1;
	2734	parity = x;
	2735	}
	2736	#endif /* PARSENSE */
	2737	ksbuf[0] = NUL; /* Don't do this next time! */
[10779]	2738
[20080]	2739	} else { /* Normally go read a packet */
	2740	#endif /* CK_AUTODL */
	2741
	2742	#ifdef DEBUG
	2743	if (deblog) {
	2744	debug(F101,"rpack timint","",timint);
	2745	debug(F101,"rpack rcvtimo","",rcvtimo);
	2746	#ifdef STREAMING
	2747	debug(F101,"rpack streaming","",streaming);
	2748	#endif /* STREAMING */
	2749	#ifdef GFTIMER
	2750	/* Measure how long it takes to read a packet */
	2751	t1 = gftimer();
	2752	#endif /* GFTIMER */
	2753	}
	2754	#endif /* DEBUG */
	2755
	2756	/* JUST IN CASE (otherwise this could clobber streaming) */
	2757
	2758	if ((timint == 0
	2759	#ifdef STREAMING
	2760	\|\| streaming
	2761	#endif /* STREAMING */
	2762	) && (rcvtimo != 0)) {
	2763	debug(F101,"rpack timint 0 \|\| streaming but rcvtimo","",rcvtimo);
	2764	rcvtimo = 0;
	2765	}
	2766
[10779]	2767	#ifdef PARSENSE
	2768	#ifdef UNIX
	2769	/*
	2770	So far the final turn argument is only for ck[uvdl]tio.c. Should be added
	2771	to the others too. (turn == handshake character.)
	2772	*/
[20080]	2773	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2774	#else
	2775	#ifdef VMS
[20080]	2776	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2777	#else
	2778	#ifdef datageneral
[20080]	2779	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2780	#else
	2781	#ifdef STRATUS
[20080]	2782	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2783	#else
	2784	#ifdef OS2
[20080]	2785	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2786	#else
	2787	#ifdef OSK
[20080]	2788	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr,turn);
[10779]	2789	#else
[20080]	2790	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e,stchr);
[10779]	2791	#endif /* OSK */
	2792	#endif /* OS2 */
	2793	#endif /* STRATUS */
	2794	#endif /* datageneral */
	2795	#endif /* VMS */
	2796	#endif /* UNIX */
[20080]	2797	if (parity != 0 && parity != 's' && ttprty != 0) {
	2798	if (parity != ttprty) autopar = 1;
	2799	parity = ttprty;
	2800	}
[10779]	2801	#else /* !PARSENSE */
[20080]	2802	j = ttinl(recpkt,r_pkt[k].bf_len - 1,rcvtimo,e);
[10779]	2803	#endif /* PARSENSE */
	2804
[20080]	2805	#ifdef DEBUG
	2806	if (deblog) {
	2807	debug(F101,"rpack ttinl len","",j);
	2808	#ifdef GFTIMER
	2809	t2 = gftimer();
	2810	debug(F101,"rpack ttinl msec","",(long)((t2-t1)*1000.0));
	2811	#endif /* GFTIMER */
	2812	}
	2813	#endif /* DEBUG */
[10779]	2814
[20080]	2815	#ifdef STREAMING
	2816	if (streaming && sndtyp == 'D' && j == 0)
	2817	return('Y');
	2818	#endif /* STREAMING */
	2819
	2820	if (j < 0) {
	2821	/* -1 == timeout, -2 == ^C, -3 == connection lost or fatal i/o */
	2822	debug(F101,"rpack: ttinl fails","",j); /* Otherwise, */
	2823	freerbuf(k); /* Free this buffer */
	2824	if (j < -1) { /* Bail out if ^C^C typed. */
	2825	if (j == -2) {
	2826	interrupted = 1;
	2827	debug(F101,"rpack ^C server","",server);
	2828	debug(F101,"rpack ^C en_fin","",en_fin);
	2829	} else if (j == -3) {
	2830	fatalio = 1;
	2831	debug(F101,"rpack fatalio","",en_fin);
	2832	}
	2833	return(j);
	2834	}
	2835	if (nakstate) /* j == -1 is a read timeout */
	2836	xxscreen(SCR_PT,'T',(long)winlo,"");
	2837	else
	2838	xxscreen(SCR_PT,'T',(long)pktnum,"");
	2839	logpkt('r',-1,(CHAR *)"<timeout>",0);
	2840	if (flow == 1) ttoc(XON); /* In case of Xoff blockage. */
	2841	return('T');
[10779]	2842	}
[20080]	2843	#ifdef CK_AUTODL
[10779]	2844	}
[20080]	2845	#endif /* CK_AUTODL */
	2846
[10779]	2847	rpktl = j;
	2848	tlci += j; /* All OK, Count the characters. */
	2849	flci += j;
	2850
[20080]	2851	/* Find start of packet */
	2852
[10779]	2853	#ifndef PARSENSE
	2854	for (i = 0; (recpkt[i] != stchr) && (i < j); i++)
	2855	sohp++; /* Find mark */
	2856	if (i++ >= j) { /* Didn't find it. */
[20080]	2857	logpkt('r',-1,"<timeout>",0);
[10779]	2858	freerbuf(k);
	2859	return('T');
[20080]	2860	}
[10779]	2861	#else
[20080]	2862	i = 1; /* ttinl does this for us */
[10779]	2863	#endif /* PARSENSE */
	2864
[20080]	2865	rpackets++; /* Count received packet. */
[10779]	2866	lp = i; /* Remember LEN position. */
[20080]	2867	if ((j = xunchar(recpkt[i++])) == 0) { /* Get packet length. */
	2868	if ((j = lp+5) > MAXRP) { /* Long packet */
	2869	return('Q'); /* Too long */
	2870	}
	2871
	2872	#ifdef CKTUNING
	2873	/* Save some function-call and loop overhead... */
	2874	#ifdef COMMENT
	2875	/* ttinl() already removed parity */
	2876	if (parity)
	2877	#endif /* COMMENT */
	2878	chk = (unsigned) ((unsigned) recpkt[i-1] +
	2879	(unsigned) recpkt[i] +
	2880	(unsigned) recpkt[i+1] +
	2881	(unsigned) recpkt[i+2] +
	2882	(unsigned) recpkt[i+3]
	2883	);
	2884	#ifdef COMMENT
	2885	else
	2886	chk = (unsigned) ((unsigned) (recpkt[i-1] & 077) +
	2887	(unsigned) (recpkt[i] & 077) +
	2888	(unsigned) (recpkt[i+1] & 077) +
	2889	(unsigned) (recpkt[i+2] & 077) +
	2890	(unsigned) (recpkt[i+3] & 077)
	2891	);
	2892	#endif /* COMMENT */
	2893	if (xunchar(recpkt[j]) != ((((chk & 0300) >> 6) + chk) & 077))
	2894	#else
[10779]	2895	x = recpkt[j]; /* Header checksum. */
	2896	recpkt[j] = '\0'; /* Calculate & compare. */
[20080]	2897	if (xunchar(x) != chk1(recpkt+lp,5))
	2898	#endif /* CKTUNING */
	2899	{
	2900	freerbuf(k);
	2901	logpkt('r',-1,(CHAR *)"<crunched:hdr>",0);
	2902	xxscreen(SCR_PT,'%',(long)pktnum,"Bad packet header");
	2903	return('Q');
	2904	}
	2905	#ifndef CKTUNING
[10779]	2906	recpkt[j] = x; /* Checksum ok, put it back. */
[20080]	2907	#endif /* CKTUNING */
[10779]	2908	rln = xunchar(recpkt[j-2]) * 95 + xunchar(recpkt[j-1]) - bctl;
	2909	j = 3; /* Data offset. */
	2910	} else if (j < 3) {
	2911	debug(F101,"rpack packet length less than 3","",j);
	2912	freerbuf(k);
[20080]	2913	logpkt('r',-1,(CHAR *)"<crunched:len>",0);
	2914	xxscreen(SCR_PT,'%',(long)pktnum,"Bad packet length");
[10779]	2915	return('Q');
	2916	} else {
	2917	rln = j - bctl - 2; /* Regular packet */
	2918	j = 0; /* No extended header */
	2919	}
	2920	rsn = xunchar(recpkt[i++]); /* Sequence number */
[20080]	2921	if (pktlog) /* Save a function call! */
	2922	logpkt('r',rsn,sohp,rln+bctl+j+4);
[10779]	2923	if (rsn < 0 \|\| rsn > 63) {
	2924	debug(F101,"rpack bad sequence number","",rsn);
	2925	freerbuf(k);
[20080]	2926	if (pktlog)
	2927	logpkt('r',rsn,(CHAR *)"<crunched:seq>",0);
	2928	xxscreen(SCR_PT,'%',(long)pktnum,"Bad sequence number");
[10779]	2929	return('Q');
	2930	}
	2931	/*
	2932	If this packet has the same type as the packet just sent, assume it is
	2933	an echo and ignore it. Don't even bother with the block check calculation:
	2934	even if the packet is corrupted, we don't want to NAK an echoed packet.
[20080]	2935	Nor must we NAK an ACK or NAK.
[10779]	2936	*/
	2937	type = recpkt[i++]; /* Get packet's TYPE field */
	2938	if (type == sndtyp \|\| (nakstate && (type == 'N' /* \|\| type == 'Y' */ ))) {
	2939	debug(F000,"rpack echo","",type); /* If it's an echo */
	2940	freerbuf(k); /* Free this buffer */
[20080]	2941	logpkt('#',rsn,(CHAR *)"<echo:ignored>",0);
	2942	return('e'); /* Return special (lowercase) code */
[10779]	2943	}
	2944	/*
[20080]	2945	Separate the data from the block check, accounting for the case where
[10779]	2946	a packet was retransmitted after the block check switched.
	2947	*/
	2948	if (type == 'I' \|\| type == 'S') { /* I & S packets always have type 1 */
	2949	chklen = 1;
	2950	rln = rln + bctl - 1;
	2951	} else if (type == 'N') { /* A NAK packet never has data */
	2952	chklen = xunchar(recpkt[lp]) - 2;
	2953	rln = rln + bctl - chklen;
	2954	} else chklen = bctl;
[20080]	2955	#ifdef DEBUG
	2956	if (deblog) { /* Save 2 function calls */
	2957	debug(F101,"rpack bctl","",bctl);
	2958	debug(F101,"rpack chklen","",chklen);
	2959	}
	2960	#endif /* DEBUG */
[10779]	2961	i += j; /* Buffer index of DATA field */
	2962	rdatap = recpkt+i; /* Pointer to DATA field */
[20080]	2963	if ((j = rln + i) > r_pkt[k].bf_len) { /* Make sure it fits */
	2964	debug(F101,"packet too long","",j);
[10779]	2965	freerbuf(k);
[20080]	2966	logpkt('r',rsn,(CHAR *)"<overflow>",0);
[10779]	2967	return('Q');
	2968	}
	2969	for (x = 0; x < chklen; x++) /* Copy the block check */
[20080]	2970	pbc[x] = recpkt[j+x]; /* 3 bytes at most. */
[10779]	2971	pbc[x] = '\0'; /* Null-terminate block check string */
[20080]	2972	recpkt[j] = '\0'; /* and the packet Data field. */
	2973
[10779]	2974	if (chklen == 2 && bctu == 4) { /* Adjust for Blank-Free-2 */
	2975	chklen = 4; /* (chklen is now a misnomer...) */
	2976	debug(F100,"rpack block check B","",0);
	2977	}
	2978	switch (chklen) { /* Check the block check */
[20080]	2979	case 1: /* Type 1, 6-bit checksum */
	2980	if (xunchar(*pbc) != chk1(recpkt+lp,j-lp)) {
	2981	#ifdef DEBUG
	2982	if (deblog) {
[10779]	2983	debug(F110,"checked chars",recpkt+lp,0);
[20080]	2984	debug(F101,"block check (1)","",(int) xunchar(*pbc));
	2985	debug(F101,"should be (1)","",chk1(recpkt+lp,j-lp));
	2986	}
	2987	#endif /* DEBUG */
	2988	freerbuf(k);
	2989	logpkt('r',-1,(CHAR *)"<crunched:chk1>",0);
	2990	xxscreen(SCR_PT,'%',(long)pktnum,"Checksum error");
	2991	return('Q');
	2992	}
	2993	break;
	2994	case 2: /* Type 2, 12-bit checksum */
	2995	x = xunchar(*pbc) << 6 \| xunchar(pbc[1]);
	2996	if (x != chk2(recpkt+lp,j-lp)) { /* No match */
	2997	if (type == 'E') { /* Allow E packets to have type 1 */
	2998	recpkt[j++] = pbc[0];
	2999	recpkt[j] = '\0';
	3000	if (xunchar(pbc[1]) == chk1(recpkt+lp,j-lp))
	3001	break;
	3002	else
	3003	recpkt[--j] = '\0';
	3004	}
	3005	#ifdef DEBUG
	3006	if (deblog) {
[10779]	3007	debug(F110,"checked chars",recpkt+lp,0);
[20080]	3008	debug(F101,"block check (2)","", x);
	3009	debug(F101,"should be (2)","", (int) chk2(recpkt+lp,j-lp));
[10779]	3010	}
[20080]	3011	#endif /* DEBUG */
	3012	freerbuf(k);
	3013	logpkt('r',-1,(CHAR *)"<crunched:chk2>",0);
	3014	xxscreen(SCR_PT,'%',(long)pktnum,"Checksum error");
	3015	return('Q');
	3016	}
	3017	break;
	3018	case 3: /* Type 3, 16-bit CRC */
	3019	crc = (xunchar(pbc[0]) << 12)
	3020	\| (xunchar(pbc[1]) << 6)
	3021	\| (xunchar(pbc[2]));
	3022	if (crc != chk3(recpkt+lp,j-lp)) {
	3023	if (type == 'E') { /* Allow E packets to have type 1 */
	3024	recpkt[j++] = pbc[0];
	3025	recpkt[j++] = pbc[1];
	3026	recpkt[j] = '\0';
	3027	if (xunchar(pbc[2]) == chk1(recpkt+lp,j-lp))
	3028	break;
	3029	else { j -=2; recpkt[j] = '\0'; }
	3030	}
	3031	#ifdef DEBUG
	3032	if (deblog) {
[10779]	3033	debug(F110,"checked chars",recpkt+lp,0);
[20080]	3034	debug(F101,"block check (3)","",crc);
	3035	debug(F101,"should be (3)","",(int) chk3(recpkt+lp,j-lp));
[10779]	3036	}
[20080]	3037	#endif /* DEBUG */
	3038	freerbuf(k);
	3039	logpkt('r',-1,(CHAR *)"<crunched:chk3>",0);
	3040	xxscreen(SCR_PT,'%',(long)pktnum,"CRC error");
	3041	return('Q');
	3042	}
	3043	break;
	3044	case 4: /* Type 4 = Type 2, no blanks. */
	3045	x = (unsigned)((xunchar(*pbc) - 1) << 6) \|
	3046	(unsigned)(xunchar(pbc[1]) - 1);
	3047	if (x != chk2(recpkt+lp,j-lp)) {
	3048	if (type == 'E') { /* Allow E packets to have type 1 */
	3049	recpkt[j++] = pbc[0];
	3050	recpkt[j] = '\0';
	3051	if (xunchar(pbc[1]) == chk1(recpkt+lp,j-lp))
	3052	break;
	3053	else
	3054	recpkt[--j] = '\0';
[10779]	3055	}
[20080]	3056	debug(F101,"bad type B block check","",x);
[10779]	3057	freerbuf(k);
[20080]	3058	logpkt('r',-1,(CHAR *)"<crunched:chkb>",0);
	3059	xxscreen(SCR_PT,'%',(long)pktnum,"Checksum error");
[10779]	3060	return('Q');
[20080]	3061	}
	3062	break;
	3063	default: /* Shouldn't happen... */
	3064	freerbuf(k);
	3065	logpkt('r',-1,(CHAR *)"<crunched:chkx>",0);
	3066	xxscreen(SCR_PT,'%',(long)pktnum,"(crunched)");
	3067	return('Q');
[10779]	3068	}
	3069	debug(F101,"rpack block check OK","",rsn);
	3070
	3071	/* Now we can believe the sequence number, and other fields. */
	3072	/* Here we violate strict principles of layering, etc, and look at the */
	3073	/* packet sequence number. If there's already a packet with the same */
	3074	/* number in the window, we remove this one so that the window will not */
	3075	/* fill up. */
	3076
	3077	if ((x = rseqtbl[rsn]) != -1) { /* Already a packet with this number */
	3078	retrans++; /* Count it for statistics */
	3079	debug(F101,"rpack got dup","",rsn);
[20080]	3080	logpkt('r',rsn,(CHAR *)"<duplicate>",0);
[10779]	3081	freerbuf(x); /* Free old buffer, keep new packet. */
	3082	r_pkt[k].pk_rtr++; /* Count this as a retransmission. */
	3083	}
	3084
	3085	/* New packet, not seen before, enter it into the receive window. */
	3086
	3087	#ifdef CK_TIMERS
[20080]	3088	if (timint > 0)
	3089	rrttbl[rsn] = gtimer(); /* Timestamp */
[10779]	3090	#endif /* CK_TIMERS */
	3091
	3092	rseqtbl[rsn] = k; /* Make back pointer */
	3093	r_pkt[k].pk_seq = rsn; /* Record in packet info structure */
	3094	r_pkt[k].pk_typ = type; /* Sequence, type,... */
	3095	r_pkt[k].pk_adr = rdatap; /* pointer to data buffer */
[20080]	3096	if (local) { /* Save a function call! */
	3097	int x = 0;
	3098	if (fdispla != XYFD_N) x = 1;
	3099	if (fdispla == XYFD_B && (type == 'D' \|\| sndtyp == 'D')) x = 0;
	3100	if (x) /* Update screen */
	3101	xxscreen(SCR_PT,(char)type,(long)rsn,(char *)sohp);
	3102	}
[10779]	3103	return(type); /* Return packet type */
	3104	}
	3105
	3106	/* L O G P K T -- Log packet number n, pointed to by s. */
	3107
	3108	/* c = 's' (send) or 'r' (receive) */
	3109
	3110	VOID
	3111	#ifdef CK_ANSIC
[20080]	3112	logpkt(char c,int n, CHAR *s, int len)
[10779]	3113	#else
[20080]	3114	logpkt(c,n,s,len) char c; int n; CHAR *s; int len;
[10779]	3115	#endif /* CK_ANSIC */
	3116	/* logpkt */ {
	3117	char plog[20];
[20080]	3118	if (!s) s = (CHAR *)"";
	3119	if (pktlog) if (chkfn(ZPFILE) > 0) {
	3120	if (n < 0) /* Construct entry header */
	3121	sprintf(plog,"%c-xx-%02d-",c,(gtimer()%60)); /* safe */
[10779]	3122	else
[20080]	3123	sprintf(plog,"%c-%02d-%02d-",c,n,(gtimer()%60)); /* safe */
	3124	if (zsoutx(ZPFILE,plog,(int)strlen(plog)) < 0) {
	3125	pktlog = 0;
	3126	return;
	3127	} else {
	3128	if (len == 0)
	3129	len = strlen((char *)s);
	3130	if (len > 0) {
	3131	char * p; /* Make SOP printable */
	3132	int x; /* so we can look at logs without */
	3133	p = dbchr(s); / triggering autodownload. */
	3134	x = strlen(dbchr(*s));
	3135	if (s < 32 \|\| (s > 127 && *s < 160)) {
	3136	if (zsoutx(ZPFILE,p,x) < 0) {
	3137	pktlog = 0;
	3138	return;
	3139	} else {
	3140	len--;
	3141	s++;
	3142	}
	3143	}
	3144	}
	3145	if (zsoutx(ZPFILE,(char *)s,len) < 0) {
	3146	pktlog = 0;
	3147	return;
	3148	} else if (zsoutx(ZPFILE,
	3149	#ifdef UNIX
	3150	"\n", 1
	3151	#else
	3152	#ifdef datageneral
	3153	"\n", 1
	3154	#else
	3155	#ifdef OSK
	3156	"\r", 1
	3157	#else
	3158	#ifdef MAC
	3159	"\r", 1
	3160	#else
	3161	"\015\012", 2
	3162	#endif /* MAC */
	3163	#endif /* OSK */
	3164	#endif /* datageneral */
	3165	#endif /* UNIX */
	3166	) < 0) {
	3167	pktlog = 0;
	3168	}
	3169	}
[10779]	3170	}
	3171	}
	3172
	3173	/* T S T A T S -- Record statistics in transaction log */
	3174
	3175	VOID
	3176	tstats() {
[20080]	3177	char *tp = NULL;
	3178	#ifdef GFTIMER
	3179	CKFLOAT xx; /* Elapsed time divisor */
	3180	#endif /* GFTIMER */
	3181
	3182	debug(F101,"tstats xfsecs","",xfsecs);
	3183	debug(F101,"tstats filcnt","",filcnt);
	3184	if (filcnt == 1) { /* Get timing for statistics */
	3185	tsecs = xfsecs; /* Single file, we already have it */
	3186	#ifdef GFTIMER
	3187	debug(F101,"tstats fpxfsecs","",(int)fpxfsecs);
	3188	fptsecs = fpxfsecs;
	3189	#endif /* GFTIMER */
	3190	} else { /* Multiple files */
	3191	tsecs = gtimer(); /* Get current time */
	3192	#ifdef GFTIMER
	3193	fptsecs = gftimer();
	3194	#endif /* GFTIMER */
	3195	}
	3196	#ifdef GFTIMER
	3197	if (fptsecs <= GFMINTIME) /* Calculate CPS */
	3198	fptsecs = (CKFLOAT) GFMINTIME;
	3199	debug(F101,"tstats fptsecs","",(int)fptsecs);
	3200	xx = (CKFLOAT) tfc / fptsecs;
	3201	if (sizeof(long) <= 4) { /* doesn't account for 16-bit longs */
	3202	if (xx > 2147483647.0)
	3203	tfcps = 2147483647L; /* 31 bits */
	3204	else
	3205	tfcps = (long) xx;
	3206	} else
	3207	tfcps = (long) xx;
	3208	#else
	3209	if (tsecs < 2L)
	3210	tsecs = 1L;
	3211	debug(F101,"tstats tsecs","",tsecs);
	3212	tfcps = tfc / tsecs;
	3213	#endif /* GFTIMER */
	3214
[10779]	3215	ztime(&tp); /* Get time stamp */
	3216	tlog(F100,"","",0L); /* Leave a blank line */
	3217	tlog(F110,"Transaction complete",tp,0L); /* Record it */
	3218
	3219	if (filcnt < 1) return; /* If no files, done. */
	3220
	3221	/* If multiple files, record character totals for all files */
	3222
	3223	if (filcnt > 1) {
	3224	tlog(F101," files transferred ","",filcnt - filrej);
	3225	tlog(F101," total file characters ","",tfc);
	3226	tlog(F101," communication line in ","",tlci);
	3227	tlog(F101," communication line out ","",tlco);
	3228	}
	3229
	3230	/* Record timing info for one or more files */
	3231
[20080]	3232	#ifdef GFTIMER
	3233	if (filcnt - filrej == 1) {
	3234	tlog(F101," elapsed time (seconds) ","",(long) fpxfsecs);
	3235	tlog(F101," effective data rate ","",filcps);
	3236	} else {
	3237	tlog(F101," elapsed time (seconds) ","",(long) fptsecs);
	3238	tlog(F101," effective data rate ","",(long) xx);
	3239	}
	3240	#else
[10779]	3241	tlog(F101," elapsed time (seconds) ","",(long) tsecs);
	3242	if (tsecs > 0) {
	3243	long lx;
	3244	lx = (tfc * 10L) / (long) tsecs;
	3245	tlog(F101," effective data rate ","",lx/10L);
	3246	}
[20080]	3247	#endif /* GFTIMER */
[10779]	3248	tlog(F100,"","",0L); /* Leave a blank line */
	3249	}
	3250
	3251	/* F S T A T S -- Record file statistics in transaction log */
	3252
	3253	VOID
[20080]	3254	fcps() {
	3255	#ifdef GFTIMER
	3256	double xx;
	3257	fpxfsecs = gftimer() - fpfsecs;
	3258	if (fpxfsecs <= GFMINTIME)
	3259	fpxfsecs = (CKFLOAT) GFMINTIME;
	3260	xx = (CKFLOAT) ffc / fpxfsecs;
	3261	if (sizeof(long) <= 4) {
	3262	if (xx > 2147483647.0)
	3263	tfcps = 2147483647L; /* 31 bits */
	3264	else
	3265	filcps = (long) xx;
	3266	} else
	3267	filcps = (long) xx;
	3268	if (sizeof(int) >= 4)
	3269	xfsecs = (int) fpxfsecs;
	3270	else if (fpxfsecs < 32768.0)
	3271	xfsecs = (int) fpxfsecs;
	3272	else
	3273	xfsecs = 32767;
	3274	#else /* GFTIMER */
	3275	xfsecs = gtimer() - fsecs;
	3276	if (xfsecs < 1L) xfsecs = 1L;
	3277	filcps = ffc / xfsecs;
	3278	#endif /* GFTIMER */
[10779]	3279	}
	3280
	3281	VOID
	3282	fstats() {
	3283	tfc += ffc;
[20080]	3284	#ifdef DEBUG
	3285	if (deblog) {
	3286	debug(F101,"fstats tfc","",tfc);
	3287	debug(F101,"fstats what","",what);
	3288	debug(F110,"fstats epktmsg",epktmsg,0);
	3289	}
	3290	#endif /* DEBUG */
	3291	#ifdef TLOG
	3292	if (!discard && !cxseen && !czseen && what != W_NOTHING && !*epktmsg)
	3293	tlog(F101," complete, size","",ffc);
	3294	#endif /* TLOG */
[10779]	3295	}
[20080]	3296
	3297	#endif /* NOXFER */

Note: See TracBrowser for help on using the repository browser.

Context Navigation

source: trunk/third/kermit/ckcfn2.c @ 20081

Download in other formats: