xref: /netbsd-src/libexec/telnetd/utility.c (revision de1dfb1250df962f1ff3a011772cf58e605aed11)
1 /*	$NetBSD: utility.c,v 1.24 2003/08/07 09:46:52 agc Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)utility.c	8.4 (Berkeley) 5/30/95";
36 #else
37 __RCSID("$NetBSD: utility.c,v 1.24 2003/08/07 09:46:52 agc Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/utsname.h>
42 #define PRINTOPTIONS
43 #include "telnetd.h"
44 
45 char *nextitem __P((char *));
46 void putstr __P((char *));
47 
48 extern int not42;
49 
50 /*
51  * utility functions performing io related tasks
52  */
53 
54 /*
55  * ttloop
56  *
57  *	A small subroutine to flush the network output buffer, get some data
58  * from the network, and pass it through the telnet state machine.  We
59  * also flush the pty input buffer (by dropping its data) if it becomes
60  * too full.
61  */
62 
63 void
64 ttloop()
65 {
66 
67     DIAG(TD_REPORT, {output_data("td: ttloop\r\n");});
68     if (nfrontp - nbackp) {
69 	netflush();
70     }
71     ncc = read(net, netibuf, sizeof netibuf);
72     if (ncc < 0) {
73 	syslog(LOG_ERR, "ttloop:  read: %m");
74 	exit(1);
75     } else if (ncc == 0) {
76 	syslog(LOG_INFO, "ttloop:  peer died: %m");
77 	exit(1);
78     }
79     DIAG(TD_REPORT, {output_data("td: ttloop read %d chars\r\n", ncc);});
80     netip = netibuf;
81     telrcv();			/* state machine */
82     if (ncc > 0) {
83 	pfrontp = pbackp = ptyobuf;
84 	telrcv();
85     }
86 }  /* end of ttloop */
87 
88 /*
89  * Check a descriptor to see if out of band data exists on it.
90  */
91 int
92 stilloob(s)
93     int	s;		/* socket number */
94 {
95     struct pollfd set[1];
96     int value;
97 
98     set[0].fd = s;
99     set[0].events = POLLPRI;
100     do {
101 	value = poll(set, 1, 0);
102     } while ((value == -1) && (errno == EINTR));
103 
104     if (value < 0) {
105 	fatalperror(pty, "poll");
106     }
107     if (set[0].revents & POLLPRI) {
108 	return 1;
109     } else {
110 	return 0;
111     }
112 }
113 
114 void
115 ptyflush()
116 {
117 	int n;
118 
119 	if ((n = pfrontp - pbackp) > 0) {
120 		DIAG((TD_REPORT | TD_PTYDATA),
121 			{ output_data("td: ptyflush %d chars\r\n", n); });
122 		DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
123 		n = write(pty, pbackp, n);
124 	}
125 	if (n < 0) {
126 		if (errno == EWOULDBLOCK || errno == EINTR)
127 			return;
128 		cleanup(0);
129 	}
130 	pbackp += n;
131 	if (pbackp == pfrontp)
132 		pbackp = pfrontp = ptyobuf;
133 }
134 
135 /*
136  * nextitem()
137  *
138  *	Return the address of the next "item" in the TELNET data
139  * stream.  This will be the address of the next character if
140  * the current address is a user data character, or it will
141  * be the address of the character following the TELNET command
142  * if the current address is a TELNET IAC ("I Am a Command")
143  * character.
144  */
145 char *
146 nextitem(current)
147     char	*current;
148 {
149     if ((*current&0xff) != IAC) {
150 	return current+1;
151     }
152     switch (*(current+1)&0xff) {
153     case DO:
154     case DONT:
155     case WILL:
156     case WONT:
157 	return current+3;
158     case SB:		/* loop forever looking for the SE */
159 	{
160 	    register char *look = current+2;
161 
162 	    for (;;) {
163 		if ((*look++&0xff) == IAC) {
164 		    if ((*look++&0xff) == SE) {
165 			return look;
166 		    }
167 		}
168 	    }
169 	}
170     default:
171 	return current+2;
172     }
173 }  /* end of nextitem */
174 
175 
176 /*
177  * netclear()
178  *
179  *	We are about to do a TELNET SYNCH operation.  Clear
180  * the path to the network.
181  *
182  *	Things are a bit tricky since we may have sent the first
183  * byte or so of a previous TELNET command into the network.
184  * So, we have to scan the network buffer from the beginning
185  * until we are up to where we want to be.
186  *
187  *	A side effect of what we do, just to keep things
188  * simple, is to clear the urgent data pointer.  The principal
189  * caller should be setting the urgent data pointer AFTER calling
190  * us in any case.
191  */
192 void
193 netclear()
194 {
195     register char *thisitem, *next;
196     char *good;
197 #define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \
198 				((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
199 
200 #ifdef	ENCRYPTION
201     thisitem = nclearto > netobuf ? nclearto : netobuf;
202 #else /* ENCRYPTION */
203     thisitem = netobuf;
204 #endif	/* ENCRYPTION */
205 
206     while ((next = nextitem(thisitem)) <= nbackp) {
207 	thisitem = next;
208     }
209 
210     /* Now, thisitem is first before/at boundary. */
211 
212 #ifdef	ENCRYPTION
213     good = nclearto > netobuf ? nclearto : netobuf;
214 #else /* ENCRYPTION */
215     good = netobuf;	/* where the good bytes go */
216 #endif	/* ENCRYPTION */
217 
218     while (nfrontp > thisitem) {
219 	if (wewant(thisitem)) {
220 	    int length;
221 
222 	    next = thisitem;
223 	    do {
224 		next = nextitem(next);
225 	    } while (wewant(next) && (nfrontp > next));
226 	    length = next-thisitem;
227 	    memmove(good, thisitem, length);
228 	    good += length;
229 	    thisitem = next;
230 	} else {
231 	    thisitem = nextitem(thisitem);
232 	}
233     }
234 
235     nbackp = netobuf;
236     nfrontp = good;		/* next byte to be sent */
237     neturg = 0;
238 }  /* end of netclear */
239 
240 /*
241  *  netflush
242  *		Send as much data as possible to the network,
243  *	handling requests for urgent data.
244  */
245 void
246 netflush()
247 {
248     int n;
249 
250     if ((n = nfrontp - nbackp) > 0) {
251 	DIAG(TD_REPORT,
252 	    { output_data("td: netflush %d chars\r\n", n);
253 	      n = nfrontp - nbackp;	/* re-compute count */
254 	    });
255 #ifdef	ENCRYPTION
256 	if (encrypt_output) {
257 		char *s = nclearto ? nclearto : nbackp;
258 		if (nfrontp - s > 0) {
259 			(*encrypt_output)((unsigned char *)s, nfrontp - s);
260 			nclearto = nfrontp;
261 		}
262 	}
263 #endif	/* ENCRYPTION */
264 	/*
265 	 * if no urgent data, or if the other side appears to be an
266 	 * old 4.2 client (and thus unable to survive TCP urgent data),
267 	 * write the entire buffer in non-OOB mode.
268 	 */
269 	if ((neturg == 0) || (not42 == 0)) {
270 	    n = write(net, nbackp, n);	/* normal write */
271 	} else {
272 	    n = neturg - nbackp;
273 	    /*
274 	     * In 4.2 (and 4.3) systems, there is some question about
275 	     * what byte in a sendOOB operation is the "OOB" data.
276 	     * To make ourselves compatible, we only send ONE byte
277 	     * out of band, the one WE THINK should be OOB (though
278 	     * we really have more the TCP philosophy of urgent data
279 	     * rather than the Unix philosophy of OOB data).
280 	     */
281 	    if (n > 1) {
282 		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */
283 	    } else {
284 		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */
285 	    }
286 	}
287     }
288     if (n < 0) {
289 	if (errno == EWOULDBLOCK || errno == EINTR)
290 		return;
291 	cleanup(0);
292     }
293     nbackp += n;
294 #ifdef	ENCRYPTION
295     if (nbackp > nclearto)
296 	nclearto = 0;
297 #endif	/* ENCRYPTION */
298     if (nbackp >= neturg) {
299 	neturg = 0;
300     }
301     if (nbackp == nfrontp) {
302 	nbackp = nfrontp = netobuf;
303 #ifdef	ENCRYPTION
304 	nclearto = 0;
305 #endif	/* ENCRYPTION */
306     }
307     return;
308 }  /* end of netflush */
309 
310 
311 /*
312  * writenet
313  *
314  * Just a handy little function to write a bit of raw data to the net.
315  * It will force a transmit of the buffer if necessary
316  *
317  * arguments
318  *    ptr - A pointer to a character string to write
319  *    len - How many bytes to write
320  */
321 void
322 writenet(ptr, len)
323 	register unsigned char *ptr;
324 	register int len;
325 {
326 	/* flush buffer if no room for new data) */
327 	if ((&netobuf[BUFSIZ] - nfrontp) < len) {
328 		/* if this fails, don't worry, buffer is a little big */
329 		netflush();
330 	}
331 
332 	memmove(nfrontp, ptr, len);
333 	nfrontp += len;
334 
335 }  /* end of writenet */
336 
337 
338 /*
339  * miscellaneous functions doing a variety of little jobs follow ...
340  */
341 void
342 fatal(f, msg)
343 	int f;
344 	const char *msg;
345 {
346 	char buf[BUFSIZ];
347 
348 	(void)snprintf(buf, sizeof buf, "telnetd: %s.\r\n", msg);
349 #ifdef	ENCRYPTION
350 	if (encrypt_output) {
351 		/*
352 		 * Better turn off encryption first....
353 		 * Hope it flushes...
354 		 */
355 		encrypt_send_end();
356 		netflush();
357 	}
358 #endif	/* ENCRYPTION */
359 	(void)write(f, buf, (int)strlen(buf));
360 	sleep(1);	/*XXX*/
361 	exit(1);
362 }
363 
364 void
365 fatalperror(f, msg)
366 	int f;
367 	const char *msg;
368 {
369 	char buf[BUFSIZ];
370 
371 	(void)snprintf(buf, sizeof buf, "%s: %s", msg, strerror(errno));
372 	fatal(f, buf);
373 }
374 
375 char editedhost[MAXHOSTNAMELEN];
376 
377 void
378 edithost(pat, host)
379 	register char *pat;
380 	register char *host;
381 {
382 	register char *res = editedhost;
383 
384 	if (!pat)
385 		pat = "";
386 	while (*pat) {
387 		switch (*pat) {
388 
389 		case '#':
390 			if (*host)
391 				host++;
392 			break;
393 
394 		case '@':
395 			if (*host)
396 				*res++ = *host++;
397 			break;
398 
399 		default:
400 			*res++ = *pat;
401 			break;
402 		}
403 		if (res == &editedhost[sizeof editedhost - 1]) {
404 			*res = '\0';
405 			return;
406 		}
407 		pat++;
408 	}
409 	if (*host)
410 		(void) strncpy(res, host,
411 		    sizeof editedhost - (res - editedhost) -1);
412 	else
413 		*res = '\0';
414 	editedhost[sizeof editedhost - 1] = '\0';
415 }
416 
417 static char *putlocation;
418 
419 void
420 putstr(s)
421 	register char *s;
422 {
423 
424 	while (*s)
425 		putchr(*s++);
426 }
427 
428 void
429 putchr(cc)
430 	int cc;
431 {
432 	*putlocation++ = cc;
433 }
434 
435 /*
436  * This is split on two lines so that SCCS will not see the M
437  * between two % signs and expand it...
438  */
439 static char fmtstr[] = { "%l:%M\
440 %p on %A, %d %B %Y" };
441 
442 char *
443 putf(cp, where)
444 	register char *cp;
445 	char *where;
446 {
447 	char *slash;
448 	time_t t;
449 	char db[100];
450 	struct utsname utsinfo;
451 
452 	uname(&utsinfo);
453 
454 	putlocation = where;
455 
456 	while (*cp) {
457 		if (*cp != '%') {
458 			putchr(*cp++);
459 			continue;
460 		}
461 		switch (*++cp) {
462 
463 		case 't':
464 			slash = strrchr(line, '/');
465 			if (slash == (char *) 0)
466 				putstr(line);
467 			else
468 				putstr(&slash[1]);
469 			break;
470 
471 		case 'h':
472 			putstr(editedhost);
473 			break;
474 
475 		case 'd':
476 			(void)time(&t);
477 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
478 			putstr(db);
479 			break;
480 
481 		case '%':
482 			putchr('%');
483 			break;
484 
485 		case 's':
486 			putstr(utsinfo.sysname);
487 			break;
488 
489 		case 'm':
490 			putstr(utsinfo.machine);
491 			break;
492 
493 		case 'r':
494 			putstr(utsinfo.release);
495 			break;
496 
497 		case 'v':
498 			putstr(utsinfo.version);
499                         break;
500 		}
501 		cp++;
502 	}
503 
504 	return (putlocation);
505 }
506 
507 #ifdef DIAGNOSTICS
508 /*
509  * Print telnet options and commands in plain text, if possible.
510  */
511 void
512 printoption(fmt, option)
513 	register const char *fmt;
514 	register int option;
515 {
516 	if (TELOPT_OK(option))
517 		output_data("%s %s\r\n", fmt, TELOPT(option));
518 	else if (TELCMD_OK(option))
519 		output_data("%s %s\r\n", fmt, TELCMD(option));
520 	else
521 		output_data("%s %d\r\n", fmt, option);
522 	return;
523 }
524 
525 void
526 printsub(direction, pointer, length)
527     char		direction;	/* '<' or '>' */
528     unsigned char	*pointer;	/* where suboption data sits */
529     int			length;		/* length of suboption data */
530 {
531     register int i = 0;		/* XXX gcc */
532 #if	defined(AUTHENTICATION) || defined(ENCRYPTION)
533     char buf[512];
534 #endif
535 
536 	if (!(diagnostic & TD_OPTIONS))
537 		return;
538 
539 	if (direction) {
540 	    output_data("td: %s suboption ",
541 	        direction == '<' ? "recv" : "send");
542 	    if (length >= 3) {
543 		register int j;
544 
545 		i = pointer[length - 2];
546 		j = pointer[length - 1];
547 
548 		if (i != IAC || j != SE) {
549 		    output_data("(terminated by ");
550 		    if (TELOPT_OK(i))
551 			output_data("%s ", TELOPT(i));
552 		    else if (TELCMD_OK(i))
553 			output_data("%s ", TELCMD(i));
554 		    else
555 			output_data("%d ", i);
556 		    if (TELOPT_OK(j))
557 			output_data("%s", TELOPT(j));
558 		    else if (TELCMD_OK(j))
559 			output_data("%s", TELCMD(j));
560 		    else
561 			output_data("%d", j);
562 		    output_data(", not IAC SE!) ");
563 		}
564 	    }
565 	    length -= 2;
566 	}
567 	if (length < 1) {
568 	    output_data("(Empty suboption??\?)");
569 	    return;
570 	}
571 	switch (pointer[0]) {
572 	case TELOPT_TTYPE:
573 	    output_data("TERMINAL-TYPE ");
574 	    switch (pointer[1]) {
575 	    case TELQUAL_IS:
576 		output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
577 		break;
578 	    case TELQUAL_SEND:
579 		output_data("SEND");
580 		break;
581 	    default:
582 		output_data("- unknown qualifier %d (0x%x).",
583 		    pointer[1], pointer[1]);
584 	    }
585 	    break;
586 	case TELOPT_TSPEED:
587 	    output_data("TERMINAL-SPEED");
588 	    if (length < 2) {
589 		output_data(" (empty suboption??\?)");
590 		break;
591 	    }
592 	    switch (pointer[1]) {
593 	    case TELQUAL_IS:
594 		output_data(" IS %.*s", length-2, (char *)pointer+2);
595 		break;
596 	    default:
597 		if (pointer[1] == 1)
598 		    output_data(" SEND");
599 		else
600 		    output_data(" %d (unknown)", pointer[1]);
601 		for (i = 2; i < length; i++) {
602 		    output_data(" ?%d?", pointer[i]);
603 		}
604 		break;
605 	    }
606 	    break;
607 
608 	case TELOPT_LFLOW:
609 	    output_data("TOGGLE-FLOW-CONTROL");
610 	    if (length < 2) {
611 		output_data(" (empty suboption??\?)");
612 		break;
613 	    }
614 	    switch (pointer[1]) {
615 	    case LFLOW_OFF:
616 		output_data(" OFF"); break;
617 	    case LFLOW_ON:
618 		output_data(" ON"); break;
619 	    case LFLOW_RESTART_ANY:
620 		output_data(" RESTART-ANY"); break;
621 	    case LFLOW_RESTART_XON:
622 		output_data(" RESTART-XON"); break;
623 	    default:
624 		output_data(" %d (unknown)", pointer[1]);
625 	    }
626 	    for (i = 2; i < length; i++)
627 		output_data(" ?%d?", pointer[i]);
628 	    break;
629 
630 	case TELOPT_NAWS:
631 	    output_data("NAWS");
632 	    if (length < 2) {
633 		output_data(" (empty suboption??\?)");
634 		break;
635 	    }
636 	    if (length == 2) {
637 		output_data(" ?%d?", pointer[1]);
638 		break;
639 	    }
640 	    output_data(" %d %d (%d)",
641 		pointer[1], pointer[2],
642 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
643 	    if (length == 4) {
644 		output_data(" ?%d?", pointer[3]);
645 		break;
646 	    }
647 	    output_data(" %d %d (%d)", pointer[3], pointer[4],
648 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
649 	    for (i = 5; i < length; i++) {
650 		output_data(" ?%d?", pointer[i]);
651 	    }
652 	    break;
653 
654 	case TELOPT_LINEMODE:
655 	    output_data("LINEMODE ");
656 	    if (length < 2) {
657 		output_data(" (empty suboption??\?)");
658 		break;
659 	    }
660 	    switch (pointer[1]) {
661 	    case WILL:
662 		output_data("WILL ");
663 		goto common;
664 	    case WONT:
665 		output_data("WONT ");
666 		goto common;
667 	    case DO:
668 		output_data("DO ");
669 		goto common;
670 	    case DONT:
671 		output_data("DONT ");
672 	    common:
673 		if (length < 3) {
674 		    output_data("(no option??\?)");
675 		    break;
676 		}
677 		switch (pointer[2]) {
678 		case LM_FORWARDMASK:
679 		    output_data("Forward Mask");
680 		    for (i = 3; i < length; i++)
681 			output_data(" %x", pointer[i]);
682 		    break;
683 		default:
684 		    output_data("%d (unknown)", pointer[2]);
685 		    for (i = 3; i < length; i++)
686 			output_data(" %d", pointer[i]);
687 		    break;
688 		}
689 		break;
690 
691 	    case LM_SLC:
692 		output_data("SLC");
693 		for (i = 2; i < length - 2; i += 3) {
694 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
695 			output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
696 		    else
697 			output_data(" %d", pointer[i+SLC_FUNC]);
698 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
699 		    case SLC_NOSUPPORT:
700 			output_data(" NOSUPPORT"); break;
701 		    case SLC_CANTCHANGE:
702 			output_data(" CANTCHANGE"); break;
703 		    case SLC_VARIABLE:
704 			output_data(" VARIABLE"); break;
705 		    case SLC_DEFAULT:
706 			output_data(" DEFAULT"); break;
707 		    }
708 		    output_data("%s%s%s",
709 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
710 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
711 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
712 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
713 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
714 			output_data("(0x%x)", pointer[i+SLC_FLAGS]);
715 		    }
716 		    output_data(" %d;", pointer[i+SLC_VALUE]);
717 		    if ((pointer[i+SLC_VALUE] == IAC) &&
718 			(pointer[i+SLC_VALUE+1] == IAC))
719 				i++;
720 		}
721 		for (; i < length; i++)
722 		    output_data(" ?%d?", pointer[i]);
723 		break;
724 
725 	    case LM_MODE:
726 		output_data("MODE ");
727 		if (length < 3) {
728 		    output_data("(no mode??\?)");
729 		    break;
730 		}
731 		{
732 		    char tbuf[32];
733 
734 		    (void)snprintf(tbuf, sizeof tbuf, "%s%s%s%s%s",
735 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
736 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
737 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
738 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
739 			pointer[2]&MODE_ACK ? "|ACK" : "");
740 		    output_data("%s", tbuf[1] ? &tbuf[1] : "0");
741 		}
742 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK))
743 		    output_data(" (0x%x)", pointer[2]);
744 		for (i = 3; i < length; i++)
745 		    output_data(" ?0x%x?", pointer[i]);
746 		break;
747 	    default:
748 		output_data("%d (unknown)", pointer[1]);
749 		for (i = 2; i < length; i++)
750 		    output_data(" %d", pointer[i]);
751 	    }
752 	    break;
753 
754 	case TELOPT_STATUS: {
755 	    register char *cp;
756 	    register int j, k;
757 
758 	    output_data("STATUS");
759 
760 	    switch (pointer[1]) {
761 	    default:
762 		if (pointer[1] == TELQUAL_SEND)
763 		    output_data(" SEND");
764 		else
765 		    output_data(" %d (unknown)", pointer[1]);
766 		for (i = 2; i < length; i++)
767 		    output_data(" ?%d?", pointer[i]);
768 		break;
769 	    case TELQUAL_IS:
770 		output_data(" IS\r\n");
771 
772 		for (i = 2; i < length; i++) {
773 		    switch(pointer[i]) {
774 		    case DO:	cp = "DO"; goto common2;
775 		    case DONT:	cp = "DONT"; goto common2;
776 		    case WILL:	cp = "WILL"; goto common2;
777 		    case WONT:	cp = "WONT"; goto common2;
778 		    common2:
779 			i++;
780 			if (TELOPT_OK(pointer[i]))
781 			    output_data(" %s %s", cp, TELOPT(pointer[i]));
782 			else
783 			    output_data(" %s %d", cp, pointer[i]);
784 
785 			output_data("\r\n");
786 			break;
787 
788 		    case SB:
789 			output_data(" SB ");
790 			i++;
791 			j = k = i;
792 			while (j < length) {
793 			    if (pointer[j] == SE) {
794 				if (j+1 == length)
795 				    break;
796 				if (pointer[j+1] == SE)
797 				    j++;
798 				else
799 				    break;
800 			    }
801 			    pointer[k++] = pointer[j++];
802 			}
803 			printsub(0, &pointer[i], k - i);
804 			if (i < length) {
805 			    output_data(" SE");
806 			    i = j;
807 			} else
808 			    i = j - 1;
809 
810 			output_data("\r\n");
811 
812 			break;
813 
814 		    default:
815 			output_data(" %d", pointer[i]);
816 			break;
817 		    }
818 		}
819 		break;
820 	    }
821 	    break;
822 	  }
823 
824 	case TELOPT_XDISPLOC:
825 	    output_data("X-DISPLAY-LOCATION ");
826 	    switch (pointer[1]) {
827 	    case TELQUAL_IS:
828 		output_data("IS \"%.*s\"", length - 2, (char *)pointer + 2);
829 		break;
830 	    case TELQUAL_SEND:
831 		output_data("SEND");
832 		break;
833 	    default:
834 		output_data("- unknown qualifier %d (0x%x).",
835 		    pointer[1], pointer[1]);
836 	    }
837 	    break;
838 
839 	case TELOPT_NEW_ENVIRON:
840 	    output_data("NEW-ENVIRON ");
841 	    goto env_common1;
842 	case TELOPT_OLD_ENVIRON:
843 	    output_data("OLD-ENVIRON");
844 	env_common1:
845 	    switch (pointer[1]) {
846 	    case TELQUAL_IS:
847 		output_data("IS ");
848 		goto env_common;
849 	    case TELQUAL_SEND:
850 		output_data("SEND ");
851 		goto env_common;
852 	    case TELQUAL_INFO:
853 		output_data("INFO ");
854 	    env_common:
855 		{
856 		    register int noquote = 2;
857 		    for (i = 2; i < length; i++ ) {
858 			switch (pointer[i]) {
859 			case NEW_ENV_VAR:
860 			    output_data("%s", "\" VAR " + noquote);
861 			    noquote = 2;
862 			    break;
863 
864 			case NEW_ENV_VALUE:
865 			    output_data("%s", "\" VALUE " + noquote);
866 			    noquote = 2;
867 			    break;
868 
869 			case ENV_ESC:
870 			    output_data("%s", "\" ESC " + noquote);
871 			    noquote = 2;
872 			    break;
873 
874 			case ENV_USERVAR:
875 			    output_data("%s", "\" USERVAR " + noquote);
876 			    noquote = 2;
877 			    break;
878 
879 			default:
880 			    if (isprint(pointer[i]) && pointer[i] != '"') {
881 				if (noquote) {
882 				    output_data("\"");
883 				    noquote = 0;
884 				}
885 				output_data("%c", pointer[i]);
886 			    } else {
887 				output_data("\" %03o " + noquote, pointer[i]);
888 				noquote = 2;
889 			    }
890 			    break;
891 			}
892 		    }
893 		    if (!noquote)
894 			output_data("\"");
895 		    break;
896 		}
897 	    }
898 	    break;
899 
900 #ifdef AUTHENTICATION
901 	case TELOPT_AUTHENTICATION:
902 	    output_data("AUTHENTICATION");
903 
904 	    if (length < 2) {
905 		output_data(" (empty suboption??\?)");
906 		break;
907 	    }
908 	    switch (pointer[1]) {
909 	    case TELQUAL_REPLY:
910 	    case TELQUAL_IS:
911 		output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
912 		    "IS" : "REPLY");
913 		if (AUTHTYPE_NAME_OK(pointer[2]))
914 		    output_data("%s ", AUTHTYPE_NAME(pointer[2]));
915 		else
916 		    output_data("%d ", pointer[2]);
917 		if (length < 3) {
918 		    output_data("(partial suboption??\?)");
919 		    break;
920 		}
921 		output_data("%s|%s",
922 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
923 			"CLIENT" : "SERVER",
924 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
925 			"MUTUAL" : "ONE-WAY");
926 
927 		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
928 		output_data("%s", buf);
929 		break;
930 
931 	    case TELQUAL_SEND:
932 		i = 2;
933 		output_data(" SEND ");
934 		while (i < length) {
935 		    if (AUTHTYPE_NAME_OK(pointer[i]))
936 			output_data("%s ", AUTHTYPE_NAME(pointer[i]));
937 		    else
938 			output_data("%d ", pointer[i]);
939 		    if (++i >= length) {
940 			output_data("(partial suboption??\?)");
941 			break;
942 		    }
943 		    output_data("%s|%s ",
944 			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
945 							"CLIENT" : "SERVER",
946 			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
947 							"MUTUAL" : "ONE-WAY");
948 		    ++i;
949 		}
950 		break;
951 
952 	    case TELQUAL_NAME:
953 		i = 2;
954 		output_data(" NAME \"");
955 		while (i < length) {
956 		    if (isprint(pointer[i]))
957 			output_data("%c", pointer[i++]);
958 		    else
959 			output_data("\"%03o\"",pointer[i++]);
960 		}
961 		output_data("\"");
962 		break;
963 
964 	    default:
965 		for (i = 2; i < length; i++)
966 		    output_data(" ?%d?", pointer[i]);
967 		break;
968 	    }
969 	    break;
970 #endif
971 
972 #ifdef	ENCRYPTION
973 	case TELOPT_ENCRYPT:
974 	    output_data("ENCRYPT");
975 	    if (length < 2) {
976 		output_data(" (empty suboption??\?)");
977 		break;
978 	    }
979 	    switch (pointer[1]) {
980 	    case ENCRYPT_START:
981 		output_data(" START");
982 		break;
983 
984 	    case ENCRYPT_END:
985 		output_data(" END");
986 		break;
987 
988 	    case ENCRYPT_REQSTART:
989 		output_data(" REQUEST-START");
990 		break;
991 
992 	    case ENCRYPT_REQEND:
993 		output_data(" REQUEST-END");
994 		break;
995 
996 	    case ENCRYPT_IS:
997 	    case ENCRYPT_REPLY:
998 		output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
999 		    "IS" : "REPLY");
1000 		if (length < 3) {
1001 			output_data(" (partial suboption??\?)");
1002 			break;
1003 		}
1004 		if (ENCTYPE_NAME_OK(pointer[2]))
1005 			output_data("%s ", ENCTYPE_NAME(pointer[2]));
1006 		else
1007 			output_data(" %d (unknown)", pointer[2]);
1008 
1009 		encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
1010 		output_data("%s", buf);
1011 		break;
1012 
1013 	    case ENCRYPT_SUPPORT:
1014 		i = 2;
1015 		output_data(" SUPPORT ");
1016 		while (i < length) {
1017 			if (ENCTYPE_NAME_OK(pointer[i]))
1018 				output_data("%s ", ENCTYPE_NAME(pointer[i]));
1019 			else
1020 				output_data("%d ", pointer[i]);
1021 			i++;
1022 		}
1023 		break;
1024 
1025 	    case ENCRYPT_ENC_KEYID:
1026 		output_data(" ENC_KEYID");
1027 		goto encommon;
1028 
1029 	    case ENCRYPT_DEC_KEYID:
1030 		output_data(" DEC_KEYID");
1031 		goto encommon;
1032 
1033 	    default:
1034 		output_data(" %d (unknown)", pointer[1]);
1035 	    encommon:
1036 		for (i = 2; i < length; i++)
1037 			output_data(" %d", pointer[i]);
1038 		break;
1039 	    }
1040 	    break;
1041 #endif	/* ENCRYPTION */
1042 
1043 	default:
1044 	    if (TELOPT_OK(pointer[0]))
1045 		output_data("%s (unknown)", TELOPT(pointer[0]));
1046 	    else
1047 		output_data("%d (unknown)", pointer[i]);
1048 	    for (i = 1; i < length; i++)
1049 		output_data(" %d", pointer[i]);
1050 	    break;
1051 	}
1052 	output_data("\r\n");
1053 }
1054 
1055 /*
1056  * Dump a data buffer in hex and ascii to the output data stream.
1057  */
1058 void
1059 printdata(tag, ptr, cnt)
1060 	register char *tag;
1061 	register char *ptr;
1062 	register int cnt;
1063 {
1064 	register int i;
1065 	char xbuf[30];
1066 
1067 	while (cnt) {
1068 		/* flush net output buffer if no room for new data) */
1069 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1070 			netflush();
1071 		}
1072 
1073 		/* add a line of output */
1074 		output_data("%s: ", tag);
1075 		for (i = 0; i < 20 && cnt; i++) {
1076 			output_data("%02x", *ptr);
1077 			if (isprint(*ptr)) {
1078 				xbuf[i] = *ptr;
1079 			} else {
1080 				xbuf[i] = '.';
1081 			}
1082 			if (i % 2)
1083 				output_data(" ");
1084 			cnt--;
1085 			ptr++;
1086 		}
1087 		xbuf[i] = '\0';
1088 		output_data(" %s\r\n", xbuf);
1089 	}
1090 }
1091 #endif /* DIAGNOSTICS */
1092