xref: /netbsd-src/libexec/telnetd/utility.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 /* from: static char sccsid[] = "@(#)utility.c	8.2 (Berkeley) 12/15/93"; */
36 static char *rcsid = "$Id: utility.c,v 1.7 1994/06/05 14:27:12 cgd Exp $";
37 #endif /* not lint */
38 
39 #include <sys/utsname.h>
40 #define PRINTOPTIONS
41 #include "telnetd.h"
42 
43 /*
44  * utility functions performing io related tasks
45  */
46 
47 /*
48  * ttloop
49  *
50  *	A small subroutine to flush the network output buffer, get some data
51  * from the network, and pass it through the telnet state machine.  We
52  * also flush the pty input buffer (by dropping its data) if it becomes
53  * too full.
54  */
55 
56     void
57 ttloop()
58 {
59     void netflush();
60 
61     DIAG(TD_REPORT, {sprintf(nfrontp, "td: ttloop\r\n");
62 		     nfrontp += strlen(nfrontp);});
63     if (nfrontp-nbackp) {
64 	netflush();
65     }
66     ncc = read(net, netibuf, sizeof netibuf);
67     if (ncc < 0) {
68 	syslog(LOG_INFO, "ttloop:  read: %m\n");
69 	exit(1);
70     } else if (ncc == 0) {
71 	syslog(LOG_INFO, "ttloop:  peer died: %m\n");
72 	exit(1);
73     }
74     DIAG(TD_REPORT, {sprintf(nfrontp, "td: ttloop read %d chars\r\n", ncc);
75 		     nfrontp += strlen(nfrontp);});
76     netip = netibuf;
77     telrcv();			/* state machine */
78     if (ncc > 0) {
79 	pfrontp = pbackp = ptyobuf;
80 	telrcv();
81     }
82 }  /* end of ttloop */
83 
84 /*
85  * Check a descriptor to see if out of band data exists on it.
86  */
87     int
88 stilloob(s)
89     int	s;		/* socket number */
90 {
91     static struct timeval timeout = { 0 };
92     fd_set	excepts;
93     int value;
94 
95     do {
96 	FD_ZERO(&excepts);
97 	FD_SET(s, &excepts);
98 	value = select(s+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
99     } while ((value == -1) && (errno == EINTR));
100 
101     if (value < 0) {
102 	fatalperror(pty, "select");
103     }
104     if (FD_ISSET(s, &excepts)) {
105 	return 1;
106     } else {
107 	return 0;
108     }
109 }
110 
111 	void
112 ptyflush()
113 {
114 	int n;
115 
116 	if ((n = pfrontp - pbackp) > 0) {
117 		DIAG((TD_REPORT | TD_PTYDATA),
118 			{ sprintf(nfrontp, "td: ptyflush %d chars\r\n", n);
119 			  nfrontp += strlen(nfrontp); });
120 		DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
121 		n = write(pty, pbackp, n);
122 	}
123 	if (n < 0) {
124 		if (errno == EWOULDBLOCK || errno == EINTR)
125 			return;
126 		cleanup(0);
127 	}
128 	pbackp += n;
129 	if (pbackp == pfrontp)
130 		pbackp = pfrontp = ptyobuf;
131 }
132 
133 /*
134  * nextitem()
135  *
136  *	Return the address of the next "item" in the TELNET data
137  * stream.  This will be the address of the next character if
138  * the current address is a user data character, or it will
139  * be the address of the character following the TELNET command
140  * if the current address is a TELNET IAC ("I Am a Command")
141  * character.
142  */
143     char *
144 nextitem(current)
145     char	*current;
146 {
147     if ((*current&0xff) != IAC) {
148 	return current+1;
149     }
150     switch (*(current+1)&0xff) {
151     case DO:
152     case DONT:
153     case WILL:
154     case WONT:
155 	return current+3;
156     case SB:		/* loop forever looking for the SE */
157 	{
158 	    register char *look = current+2;
159 
160 	    for (;;) {
161 		if ((*look++&0xff) == IAC) {
162 		    if ((*look++&0xff) == SE) {
163 			return look;
164 		    }
165 		}
166 	    }
167 	}
168     default:
169 	return current+2;
170     }
171 }  /* end of nextitem */
172 
173 
174 /*
175  * netclear()
176  *
177  *	We are about to do a TELNET SYNCH operation.  Clear
178  * the path to the network.
179  *
180  *	Things are a bit tricky since we may have sent the first
181  * byte or so of a previous TELNET command into the network.
182  * So, we have to scan the network buffer from the beginning
183  * until we are up to where we want to be.
184  *
185  *	A side effect of what we do, just to keep things
186  * simple, is to clear the urgent data pointer.  The principal
187  * caller should be setting the urgent data pointer AFTER calling
188  * us in any case.
189  */
190     void
191 netclear()
192 {
193     register char *thisitem, *next;
194     char *good;
195 #define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \
196 				((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
197 
198     thisitem = netobuf;
199 
200     while ((next = nextitem(thisitem)) <= nbackp) {
201 	thisitem = next;
202     }
203 
204     /* Now, thisitem is first before/at boundary. */
205 
206     good = netobuf;	/* where the good bytes go */
207 
208     while (nfrontp > thisitem) {
209 	if (wewant(thisitem)) {
210 	    int length;
211 
212 	    next = thisitem;
213 	    do {
214 		next = nextitem(next);
215 	    } while (wewant(next) && (nfrontp > next));
216 	    length = next-thisitem;
217 	    bcopy(thisitem, good, length);
218 	    good += length;
219 	    thisitem = next;
220 	} else {
221 	    thisitem = nextitem(thisitem);
222 	}
223     }
224 
225     nbackp = netobuf;
226     nfrontp = good;		/* next byte to be sent */
227     neturg = 0;
228 }  /* end of netclear */
229 
230 /*
231  *  netflush
232  *		Send as much data as possible to the network,
233  *	handling requests for urgent data.
234  */
235     void
236 netflush()
237 {
238     int n;
239     extern int not42;
240 
241     if ((n = nfrontp - nbackp) > 0) {
242 	DIAG(TD_REPORT,
243 	    { sprintf(nfrontp, "td: netflush %d chars\r\n", n);
244 	      n += strlen(nfrontp);  /* get count first */
245 	      nfrontp += strlen(nfrontp);  /* then move pointer */
246 	    });
247 	/*
248 	 * if no urgent data, or if the other side appears to be an
249 	 * old 4.2 client (and thus unable to survive TCP urgent data),
250 	 * write the entire buffer in non-OOB mode.
251 	 */
252 	if ((neturg == 0) || (not42 == 0)) {
253 	    n = write(net, nbackp, n);	/* normal write */
254 	} else {
255 	    n = neturg - nbackp;
256 	    /*
257 	     * In 4.2 (and 4.3) systems, there is some question about
258 	     * what byte in a sendOOB operation is the "OOB" data.
259 	     * To make ourselves compatible, we only send ONE byte
260 	     * out of band, the one WE THINK should be OOB (though
261 	     * we really have more the TCP philosophy of urgent data
262 	     * rather than the Unix philosophy of OOB data).
263 	     */
264 	    if (n > 1) {
265 		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */
266 	    } else {
267 		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */
268 	    }
269 	}
270     }
271     if (n < 0) {
272 	if (errno == EWOULDBLOCK || errno == EINTR)
273 		return;
274 	cleanup(0);
275     }
276     nbackp += n;
277     if (nbackp >= neturg) {
278 	neturg = 0;
279     }
280     if (nbackp == nfrontp) {
281 	nbackp = nfrontp = netobuf;
282     }
283     return;
284 }  /* end of netflush */
285 
286 
287 /*
288  * writenet
289  *
290  * Just a handy little function to write a bit of raw data to the net.
291  * It will force a transmit of the buffer if necessary
292  *
293  * arguments
294  *    ptr - A pointer to a character string to write
295  *    len - How many bytes to write
296  */
297 	void
298 writenet(ptr, len)
299 	register unsigned char *ptr;
300 	register int len;
301 {
302 	/* flush buffer if no room for new data) */
303 	if ((&netobuf[BUFSIZ] - nfrontp) < len) {
304 		/* if this fails, don't worry, buffer is a little big */
305 		netflush();
306 	}
307 
308 	bcopy(ptr, nfrontp, len);
309 	nfrontp += len;
310 
311 }  /* end of writenet */
312 
313 
314 /*
315  * miscellaneous functions doing a variety of little jobs follow ...
316  */
317 
318 
319 	void
320 fatal(f, msg)
321 	int f;
322 	char *msg;
323 {
324 	char buf[BUFSIZ];
325 
326 	(void) sprintf(buf, "telnetd: %s.\r\n", msg);
327 	(void) write(f, buf, (int)strlen(buf));
328 	sleep(1);	/*XXX*/
329 	exit(1);
330 }
331 
332 	void
333 fatalperror(f, msg)
334 	int f;
335 	char *msg;
336 {
337 	char buf[BUFSIZ], *strerror();
338 
339 	(void) sprintf(buf, "%s: %s\r\n", msg, strerror(errno));
340 	fatal(f, buf);
341 }
342 
343 char editedhost[32];
344 
345 	void
346 edithost(pat, host)
347 	register char *pat;
348 	register char *host;
349 {
350 	register char *res = editedhost;
351 	char *strncpy();
352 
353 	if (!pat)
354 		pat = "";
355 	while (*pat) {
356 		switch (*pat) {
357 
358 		case '#':
359 			if (*host)
360 				host++;
361 			break;
362 
363 		case '@':
364 			if (*host)
365 				*res++ = *host++;
366 			break;
367 
368 		default:
369 			*res++ = *pat;
370 			break;
371 		}
372 		if (res == &editedhost[sizeof editedhost - 1]) {
373 			*res = '\0';
374 			return;
375 		}
376 		pat++;
377 	}
378 	if (*host)
379 		(void) strncpy(res, host,
380 				sizeof editedhost - (res - editedhost) -1);
381 	else
382 		*res = '\0';
383 	editedhost[sizeof editedhost - 1] = '\0';
384 }
385 
386 static char *putlocation;
387 
388 	void
389 putstr(s)
390 	register char *s;
391 {
392 
393 	while (*s)
394 		putchr(*s++);
395 }
396 
397 	void
398 putchr(cc)
399 	int cc;
400 {
401 	*putlocation++ = cc;
402 }
403 
404 /*
405  * This is split on two lines so that SCCS will not see the M
406  * between two % signs and expand it...
407  */
408 static char fmtstr[] = { "%l:%M\
409 %P on %A, %d %B %Y" };
410 
411 	void
412 putf(cp, where)
413 	register char *cp;
414 	char *where;
415 {
416 	char *slash;
417 	time_t t;
418 	char db[100];
419 	struct utsname utsinfo;
420 #ifdef	STREAMSPTY
421 	extern char *index();
422 #else
423 	extern char *rindex();
424 #endif
425 
426 	uname(&utsinfo);
427 
428 	putlocation = where;
429 
430 	while (*cp) {
431 		if (*cp != '%') {
432 			putchr(*cp++);
433 			continue;
434 		}
435 		switch (*++cp) {
436 
437 		case 't':
438 #ifdef	STREAMSPTY
439 			/* names are like /dev/pts/2 -- we want pts/2 */
440 			slash = index(line+1, '/');
441 #else
442 			slash = rindex(line, '/');
443 #endif
444 			if (slash == (char *) 0)
445 				putstr(line);
446 			else
447 				putstr(&slash[1]);
448 			break;
449 
450 		case 'h':
451 			putstr(editedhost);
452 			break;
453 
454 		case 'd':
455 			(void)time(&t);
456 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
457 			putstr(db);
458 			break;
459 
460 		case '%':
461 			putchr('%');
462 			break;
463 
464 		case 's':
465 			putstr(utsinfo.sysname);
466 			break;
467 
468 		case 'm':
469 			putstr(utsinfo.machine);
470 			break;
471 
472 		case 'r':
473 			putstr(utsinfo.release);
474 			break;
475 
476 		case 'v':
477 			puts(utsinfo.version);
478                         break;
479 		}
480 		cp++;
481 	}
482 }
483 
484 #ifdef DIAGNOSTICS
485 /*
486  * Print telnet options and commands in plain text, if possible.
487  */
488 	void
489 printoption(fmt, option)
490 	register char *fmt;
491 	register int option;
492 {
493 	if (TELOPT_OK(option))
494 		sprintf(nfrontp, "%s %s\r\n", fmt, TELOPT(option));
495 	else if (TELCMD_OK(option))
496 		sprintf(nfrontp, "%s %s\r\n", fmt, TELCMD(option));
497 	else
498 		sprintf(nfrontp, "%s %d\r\n", fmt, option);
499 	nfrontp += strlen(nfrontp);
500 	return;
501 }
502 
503     void
504 printsub(direction, pointer, length)
505     char		direction;	/* '<' or '>' */
506     unsigned char	*pointer;	/* where suboption data sits */
507     int			length;		/* length of suboption data */
508 {
509     register int i;
510     char buf[512];
511 
512         if (!(diagnostic & TD_OPTIONS))
513 		return;
514 
515 	if (direction) {
516 	    sprintf(nfrontp, "td: %s suboption ",
517 					direction == '<' ? "recv" : "send");
518 	    nfrontp += strlen(nfrontp);
519 	    if (length >= 3) {
520 		register int j;
521 
522 		i = pointer[length-2];
523 		j = pointer[length-1];
524 
525 		if (i != IAC || j != SE) {
526 		    sprintf(nfrontp, "(terminated by ");
527 		    nfrontp += strlen(nfrontp);
528 		    if (TELOPT_OK(i))
529 			sprintf(nfrontp, "%s ", TELOPT(i));
530 		    else if (TELCMD_OK(i))
531 			sprintf(nfrontp, "%s ", TELCMD(i));
532 		    else
533 			sprintf(nfrontp, "%d ", i);
534 		    nfrontp += strlen(nfrontp);
535 		    if (TELOPT_OK(j))
536 			sprintf(nfrontp, "%s", TELOPT(j));
537 		    else if (TELCMD_OK(j))
538 			sprintf(nfrontp, "%s", TELCMD(j));
539 		    else
540 			sprintf(nfrontp, "%d", j);
541 		    nfrontp += strlen(nfrontp);
542 		    sprintf(nfrontp, ", not IAC SE!) ");
543 		    nfrontp += strlen(nfrontp);
544 		}
545 	    }
546 	    length -= 2;
547 	}
548 	if (length < 1) {
549 	    sprintf(nfrontp, "(Empty suboption??\?)");
550 	    nfrontp += strlen(nfrontp);
551 	    return;
552 	}
553 	switch (pointer[0]) {
554 	case TELOPT_TTYPE:
555 	    sprintf(nfrontp, "TERMINAL-TYPE ");
556 	    nfrontp += strlen(nfrontp);
557 	    switch (pointer[1]) {
558 	    case TELQUAL_IS:
559 		sprintf(nfrontp, "IS \"%.*s\"", length-2, (char *)pointer+2);
560 		break;
561 	    case TELQUAL_SEND:
562 		sprintf(nfrontp, "SEND");
563 		break;
564 	    default:
565 		sprintf(nfrontp,
566 				"- unknown qualifier %d (0x%x).",
567 				pointer[1], pointer[1]);
568 	    }
569 	    nfrontp += strlen(nfrontp);
570 	    break;
571 	case TELOPT_TSPEED:
572 	    sprintf(nfrontp, "TERMINAL-SPEED");
573 	    nfrontp += strlen(nfrontp);
574 	    if (length < 2) {
575 		sprintf(nfrontp, " (empty suboption??\?)");
576 		nfrontp += strlen(nfrontp);
577 		break;
578 	    }
579 	    switch (pointer[1]) {
580 	    case TELQUAL_IS:
581 		sprintf(nfrontp, " IS %.*s", length-2, (char *)pointer+2);
582 		nfrontp += strlen(nfrontp);
583 		break;
584 	    default:
585 		if (pointer[1] == 1)
586 		    sprintf(nfrontp, " SEND");
587 		else
588 		    sprintf(nfrontp, " %d (unknown)", pointer[1]);
589 		nfrontp += strlen(nfrontp);
590 		for (i = 2; i < length; i++) {
591 		    sprintf(nfrontp, " ?%d?", pointer[i]);
592 		    nfrontp += strlen(nfrontp);
593 		}
594 		break;
595 	    }
596 	    break;
597 
598 	case TELOPT_LFLOW:
599 	    sprintf(nfrontp, "TOGGLE-FLOW-CONTROL");
600 	    nfrontp += strlen(nfrontp);
601 	    if (length < 2) {
602 		sprintf(nfrontp, " (empty suboption??\?)");
603 		nfrontp += strlen(nfrontp);
604 		break;
605 	    }
606 	    switch (pointer[1]) {
607 	    case LFLOW_OFF:
608 		sprintf(nfrontp, " OFF"); break;
609 	    case LFLOW_ON:
610 		sprintf(nfrontp, " ON"); break;
611 	    case LFLOW_RESTART_ANY:
612 		sprintf(nfrontp, " RESTART-ANY"); break;
613 	    case LFLOW_RESTART_XON:
614 		sprintf(nfrontp, " RESTART-XON"); break;
615 	    default:
616 		sprintf(nfrontp, " %d (unknown)", pointer[1]);
617 	    }
618 	    nfrontp += strlen(nfrontp);
619 	    for (i = 2; i < length; i++) {
620 		sprintf(nfrontp, " ?%d?", pointer[i]);
621 		nfrontp += strlen(nfrontp);
622 	    }
623 	    break;
624 
625 	case TELOPT_NAWS:
626 	    sprintf(nfrontp, "NAWS");
627 	    nfrontp += strlen(nfrontp);
628 	    if (length < 2) {
629 		sprintf(nfrontp, " (empty suboption??\?)");
630 		nfrontp += strlen(nfrontp);
631 		break;
632 	    }
633 	    if (length == 2) {
634 		sprintf(nfrontp, " ?%d?", pointer[1]);
635 		nfrontp += strlen(nfrontp);
636 		break;
637 	    }
638 	    sprintf(nfrontp, " %d %d (%d)",
639 		pointer[1], pointer[2],
640 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
641 	    nfrontp += strlen(nfrontp);
642 	    if (length == 4) {
643 		sprintf(nfrontp, " ?%d?", pointer[3]);
644 		nfrontp += strlen(nfrontp);
645 		break;
646 	    }
647 	    sprintf(nfrontp, " %d %d (%d)",
648 		pointer[3], pointer[4],
649 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
650 	    nfrontp += strlen(nfrontp);
651 	    for (i = 5; i < length; i++) {
652 		sprintf(nfrontp, " ?%d?", pointer[i]);
653 		nfrontp += strlen(nfrontp);
654 	    }
655 	    break;
656 
657 	case TELOPT_LINEMODE:
658 	    sprintf(nfrontp, "LINEMODE ");
659 	    nfrontp += strlen(nfrontp);
660 	    if (length < 2) {
661 		sprintf(nfrontp, " (empty suboption??\?)");
662 		nfrontp += strlen(nfrontp);
663 		break;
664 	    }
665 	    switch (pointer[1]) {
666 	    case WILL:
667 		sprintf(nfrontp, "WILL ");
668 		goto common;
669 	    case WONT:
670 		sprintf(nfrontp, "WONT ");
671 		goto common;
672 	    case DO:
673 		sprintf(nfrontp, "DO ");
674 		goto common;
675 	    case DONT:
676 		sprintf(nfrontp, "DONT ");
677 	    common:
678 		nfrontp += strlen(nfrontp);
679 		if (length < 3) {
680 		    sprintf(nfrontp, "(no option??\?)");
681 		    nfrontp += strlen(nfrontp);
682 		    break;
683 		}
684 		switch (pointer[2]) {
685 		case LM_FORWARDMASK:
686 		    sprintf(nfrontp, "Forward Mask");
687 		    nfrontp += strlen(nfrontp);
688 		    for (i = 3; i < length; i++) {
689 			sprintf(nfrontp, " %x", pointer[i]);
690 			nfrontp += strlen(nfrontp);
691 		    }
692 		    break;
693 		default:
694 		    sprintf(nfrontp, "%d (unknown)", pointer[2]);
695 		    nfrontp += strlen(nfrontp);
696 		    for (i = 3; i < length; i++) {
697 			sprintf(nfrontp, " %d", pointer[i]);
698 			nfrontp += strlen(nfrontp);
699 		    }
700 		    break;
701 		}
702 		break;
703 
704 	    case LM_SLC:
705 		sprintf(nfrontp, "SLC");
706 		nfrontp += strlen(nfrontp);
707 		for (i = 2; i < length - 2; i += 3) {
708 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
709 			sprintf(nfrontp, " %s", SLC_NAME(pointer[i+SLC_FUNC]));
710 		    else
711 			sprintf(nfrontp, " %d", pointer[i+SLC_FUNC]);
712 		    nfrontp += strlen(nfrontp);
713 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
714 		    case SLC_NOSUPPORT:
715 			sprintf(nfrontp, " NOSUPPORT"); break;
716 		    case SLC_CANTCHANGE:
717 			sprintf(nfrontp, " CANTCHANGE"); break;
718 		    case SLC_VARIABLE:
719 			sprintf(nfrontp, " VARIABLE"); break;
720 		    case SLC_DEFAULT:
721 			sprintf(nfrontp, " DEFAULT"); break;
722 		    }
723 		    nfrontp += strlen(nfrontp);
724 		    sprintf(nfrontp, "%s%s%s",
725 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
726 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
727 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
728 		    nfrontp += strlen(nfrontp);
729 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
730 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
731 			sprintf(nfrontp, "(0x%x)", pointer[i+SLC_FLAGS]);
732 			nfrontp += strlen(nfrontp);
733 		    }
734 		    sprintf(nfrontp, " %d;", pointer[i+SLC_VALUE]);
735 		    nfrontp += strlen(nfrontp);
736 		    if ((pointer[i+SLC_VALUE] == IAC) &&
737 			(pointer[i+SLC_VALUE+1] == IAC))
738 				i++;
739 		}
740 		for (; i < length; i++) {
741 		    sprintf(nfrontp, " ?%d?", pointer[i]);
742 		    nfrontp += strlen(nfrontp);
743 		}
744 		break;
745 
746 	    case LM_MODE:
747 		sprintf(nfrontp, "MODE ");
748 		nfrontp += strlen(nfrontp);
749 		if (length < 3) {
750 		    sprintf(nfrontp, "(no mode??\?)");
751 		    nfrontp += strlen(nfrontp);
752 		    break;
753 		}
754 		{
755 		    char tbuf[32];
756 		    sprintf(tbuf, "%s%s%s%s%s",
757 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
758 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
759 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
760 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
761 			pointer[2]&MODE_ACK ? "|ACK" : "");
762 		    sprintf(nfrontp, "%s", tbuf[1] ? &tbuf[1] : "0");
763 		    nfrontp += strlen(nfrontp);
764 		}
765 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
766 		    sprintf(nfrontp, " (0x%x)", pointer[2]);
767 		    nfrontp += strlen(nfrontp);
768 		}
769 		for (i = 3; i < length; i++) {
770 		    sprintf(nfrontp, " ?0x%x?", pointer[i]);
771 		    nfrontp += strlen(nfrontp);
772 		}
773 		break;
774 	    default:
775 		sprintf(nfrontp, "%d (unknown)", pointer[1]);
776 		nfrontp += strlen(nfrontp);
777 		for (i = 2; i < length; i++) {
778 		    sprintf(nfrontp, " %d", pointer[i]);
779 		    nfrontp += strlen(nfrontp);
780 		}
781 	    }
782 	    break;
783 
784 	case TELOPT_STATUS: {
785 	    register char *cp;
786 	    register int j, k;
787 
788 	    sprintf(nfrontp, "STATUS");
789 	    nfrontp += strlen(nfrontp);
790 
791 	    switch (pointer[1]) {
792 	    default:
793 		if (pointer[1] == TELQUAL_SEND)
794 		    sprintf(nfrontp, " SEND");
795 		else
796 		    sprintf(nfrontp, " %d (unknown)", pointer[1]);
797 		nfrontp += strlen(nfrontp);
798 		for (i = 2; i < length; i++) {
799 		    sprintf(nfrontp, " ?%d?", pointer[i]);
800 		    nfrontp += strlen(nfrontp);
801 		}
802 		break;
803 	    case TELQUAL_IS:
804 		sprintf(nfrontp, " IS\r\n");
805 		nfrontp += strlen(nfrontp);
806 
807 		for (i = 2; i < length; i++) {
808 		    switch(pointer[i]) {
809 		    case DO:	cp = "DO"; goto common2;
810 		    case DONT:	cp = "DONT"; goto common2;
811 		    case WILL:	cp = "WILL"; goto common2;
812 		    case WONT:	cp = "WONT"; goto common2;
813 		    common2:
814 			i++;
815 			if (TELOPT_OK(pointer[i]))
816 			    sprintf(nfrontp, " %s %s", cp, TELOPT(pointer[i]));
817 			else
818 			    sprintf(nfrontp, " %s %d", cp, pointer[i]);
819 			nfrontp += strlen(nfrontp);
820 
821 			sprintf(nfrontp, "\r\n");
822 			nfrontp += strlen(nfrontp);
823 			break;
824 
825 		    case SB:
826 			sprintf(nfrontp, " SB ");
827 			nfrontp += strlen(nfrontp);
828 			i++;
829 			j = k = i;
830 			while (j < length) {
831 			    if (pointer[j] == SE) {
832 				if (j+1 == length)
833 				    break;
834 				if (pointer[j+1] == SE)
835 				    j++;
836 				else
837 				    break;
838 			    }
839 			    pointer[k++] = pointer[j++];
840 			}
841 			printsub(0, &pointer[i], k - i);
842 			if (i < length) {
843 			    sprintf(nfrontp, " SE");
844 			    nfrontp += strlen(nfrontp);
845 			    i = j;
846 			} else
847 			    i = j - 1;
848 
849 			sprintf(nfrontp, "\r\n");
850 			nfrontp += strlen(nfrontp);
851 
852 			break;
853 
854 		    default:
855 			sprintf(nfrontp, " %d", pointer[i]);
856 			nfrontp += strlen(nfrontp);
857 			break;
858 		    }
859 		}
860 		break;
861 	    }
862 	    break;
863 	  }
864 
865 	case TELOPT_XDISPLOC:
866 	    sprintf(nfrontp, "X-DISPLAY-LOCATION ");
867 	    nfrontp += strlen(nfrontp);
868 	    switch (pointer[1]) {
869 	    case TELQUAL_IS:
870 		sprintf(nfrontp, "IS \"%.*s\"", length-2, (char *)pointer+2);
871 		break;
872 	    case TELQUAL_SEND:
873 		sprintf(nfrontp, "SEND");
874 		break;
875 	    default:
876 		sprintf(nfrontp, "- unknown qualifier %d (0x%x).",
877 				pointer[1], pointer[1]);
878 	    }
879 	    nfrontp += strlen(nfrontp);
880 	    break;
881 
882 	case TELOPT_NEW_ENVIRON:
883 	    sprintf(nfrontp, "NEW-ENVIRON ");
884 	    goto env_common1;
885 	case TELOPT_OLD_ENVIRON:
886 	    sprintf(nfrontp, "OLD-ENVIRON");
887 	env_common1:
888 	    nfrontp += strlen(nfrontp);
889 	    switch (pointer[1]) {
890 	    case TELQUAL_IS:
891 		sprintf(nfrontp, "IS ");
892 		goto env_common;
893 	    case TELQUAL_SEND:
894 		sprintf(nfrontp, "SEND ");
895 		goto env_common;
896 	    case TELQUAL_INFO:
897 		sprintf(nfrontp, "INFO ");
898 	    env_common:
899 		nfrontp += strlen(nfrontp);
900 		{
901 		    register int noquote = 2;
902 		    for (i = 2; i < length; i++ ) {
903 			switch (pointer[i]) {
904 			case NEW_ENV_VAR:
905 			    sprintf(nfrontp, "\" VAR " + noquote);
906 			    nfrontp += strlen(nfrontp);
907 			    noquote = 2;
908 			    break;
909 
910 			case NEW_ENV_VALUE:
911 			    sprintf(nfrontp, "\" VALUE " + noquote);
912 			    nfrontp += strlen(nfrontp);
913 			    noquote = 2;
914 			    break;
915 
916 			case ENV_ESC:
917 			    sprintf(nfrontp, "\" ESC " + noquote);
918 			    nfrontp += strlen(nfrontp);
919 			    noquote = 2;
920 			    break;
921 
922 			case ENV_USERVAR:
923 			    sprintf(nfrontp, "\" USERVAR " + noquote);
924 			    nfrontp += strlen(nfrontp);
925 			    noquote = 2;
926 			    break;
927 
928 			default:
929 			def_case:
930 			    if (isprint(pointer[i]) && pointer[i] != '"') {
931 				if (noquote) {
932 				    *nfrontp++ = '"';
933 				    noquote = 0;
934 				}
935 				*nfrontp++ = pointer[i];
936 			    } else {
937 				sprintf(nfrontp, "\" %03o " + noquote,
938 							pointer[i]);
939 				nfrontp += strlen(nfrontp);
940 				noquote = 2;
941 			    }
942 			    break;
943 			}
944 		    }
945 		    if (!noquote)
946 			*nfrontp++ = '"';
947 		    break;
948 		}
949 	    }
950 	    break;
951 
952 #if	defined(AUTHENTICATION)
953 	case TELOPT_AUTHENTICATION:
954 	    sprintf(nfrontp, "AUTHENTICATION");
955 	    nfrontp += strlen(nfrontp);
956 
957 	    if (length < 2) {
958 		sprintf(nfrontp, " (empty suboption??\?)");
959 		nfrontp += strlen(nfrontp);
960 		break;
961 	    }
962 	    switch (pointer[1]) {
963 	    case TELQUAL_REPLY:
964 	    case TELQUAL_IS:
965 		sprintf(nfrontp, " %s ", (pointer[1] == TELQUAL_IS) ?
966 							"IS" : "REPLY");
967 		nfrontp += strlen(nfrontp);
968 		if (AUTHTYPE_NAME_OK(pointer[2]))
969 		    sprintf(nfrontp, "%s ", AUTHTYPE_NAME(pointer[2]));
970 		else
971 		    sprintf(nfrontp, "%d ", pointer[2]);
972 		nfrontp += strlen(nfrontp);
973 		if (length < 3) {
974 		    sprintf(nfrontp, "(partial suboption??\?)");
975 		    nfrontp += strlen(nfrontp);
976 		    break;
977 		}
978 		sprintf(nfrontp, "%s|%s",
979 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
980 			"CLIENT" : "SERVER",
981 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
982 			"MUTUAL" : "ONE-WAY");
983 		nfrontp += strlen(nfrontp);
984 
985 		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
986 		sprintf(nfrontp, "%s", buf);
987 		nfrontp += strlen(nfrontp);
988 		break;
989 
990 	    case TELQUAL_SEND:
991 		i = 2;
992 		sprintf(nfrontp, " SEND ");
993 		nfrontp += strlen(nfrontp);
994 		while (i < length) {
995 		    if (AUTHTYPE_NAME_OK(pointer[i]))
996 			sprintf(nfrontp, "%s ", AUTHTYPE_NAME(pointer[i]));
997 		    else
998 			sprintf(nfrontp, "%d ", pointer[i]);
999 		    nfrontp += strlen(nfrontp);
1000 		    if (++i >= length) {
1001 			sprintf(nfrontp, "(partial suboption??\?)");
1002 			nfrontp += strlen(nfrontp);
1003 			break;
1004 		    }
1005 		    sprintf(nfrontp, "%s|%s ",
1006 			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
1007 							"CLIENT" : "SERVER",
1008 			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
1009 							"MUTUAL" : "ONE-WAY");
1010 		    nfrontp += strlen(nfrontp);
1011 		    ++i;
1012 		}
1013 		break;
1014 
1015 	    case TELQUAL_NAME:
1016 		i = 2;
1017 		sprintf(nfrontp, " NAME \"");
1018 		nfrontp += strlen(nfrontp);
1019 		while (i < length)
1020 		    *nfrontp += pointer[i++];
1021 		*nfrontp += '"';
1022 		break;
1023 
1024 	    default:
1025 		    for (i = 2; i < length; i++) {
1026 			sprintf(nfrontp, " ?%d?", pointer[i]);
1027 			nfrontp += strlen(nfrontp);
1028 		    }
1029 		    break;
1030 	    }
1031 	    break;
1032 #endif
1033 
1034 
1035 	default:
1036 	    if (TELOPT_OK(pointer[0]))
1037 	        sprintf(nfrontp, "%s (unknown)", TELOPT(pointer[0]));
1038 	    else
1039 	        sprintf(nfrontp, "%d (unknown)", pointer[i]);
1040 	    nfrontp += strlen(nfrontp);
1041 	    for (i = 1; i < length; i++) {
1042 		sprintf(nfrontp, " %d", pointer[i]);
1043 		nfrontp += strlen(nfrontp);
1044 	    }
1045 	    break;
1046 	}
1047 	sprintf(nfrontp, "\r\n");
1048 	nfrontp += strlen(nfrontp);
1049 }
1050 
1051 /*
1052  * Dump a data buffer in hex and ascii to the output data stream.
1053  */
1054 	void
1055 printdata(tag, ptr, cnt)
1056 	register char *tag;
1057 	register char *ptr;
1058 	register int cnt;
1059 {
1060 	register int i;
1061 	char xbuf[30];
1062 
1063 	while (cnt) {
1064 		/* flush net output buffer if no room for new data) */
1065 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1066 			netflush();
1067 		}
1068 
1069 		/* add a line of output */
1070 		sprintf(nfrontp, "%s: ", tag);
1071 		nfrontp += strlen(nfrontp);
1072 		for (i = 0; i < 20 && cnt; i++) {
1073 			sprintf(nfrontp, "%02x", *ptr);
1074 			nfrontp += strlen(nfrontp);
1075 			if (isprint(*ptr)) {
1076 				xbuf[i] = *ptr;
1077 			} else {
1078 				xbuf[i] = '.';
1079 			}
1080 			if (i % 2) {
1081 				*nfrontp = ' ';
1082 				nfrontp++;
1083 			}
1084 			cnt--;
1085 			ptr++;
1086 		}
1087 		xbuf[i] = '\0';
1088 		sprintf(nfrontp, " %s\r\n", xbuf );
1089 		nfrontp += strlen(nfrontp);
1090 	}
1091 }
1092 #endif /* DIAGNOSTICS */
1093