xref: /netbsd-src/libexec/telnetd/utility.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: utility.c,v 1.28 2005/03/17 01:34:41 christos 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 1.28 2005/03/17 01:34:41 christos Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/utsname.h>
42 #define PRINTOPTIONS
43 #include "telnetd.h"
44 
45 char *nextitem(char *);
46 void putstr(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(void)
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(int s /* socket number */)
93 {
94     struct pollfd set[1];
95     int value;
96 
97     set[0].fd = s;
98     set[0].events = POLLPRI;
99     do {
100 	value = poll(set, 1, 0);
101     } while ((value == -1) && (errno == EINTR));
102 
103     if (value < 0) {
104 	fatalperror(pty, "poll");
105     }
106     if (set[0].revents & POLLPRI) {
107 	return 1;
108     } else {
109 	return 0;
110     }
111 }
112 
113 void
114 ptyflush(void)
115 {
116 	int n;
117 
118 	if ((n = pfrontp - pbackp) > 0) {
119 		DIAG((TD_REPORT | TD_PTYDATA),
120 			{ output_data("td: ptyflush %d chars\r\n", n); });
121 		DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
122 		n = write(pty, pbackp, n);
123 	}
124 	if (n < 0) {
125 		if (errno == EWOULDBLOCK || errno == EINTR)
126 			return;
127 		cleanup(0);
128 	}
129 	pbackp += n;
130 	if (pbackp == pfrontp)
131 		pbackp = pfrontp = ptyobuf;
132 }
133 
134 /*
135  * nextitem()
136  *
137  *	Return the address of the next "item" in the TELNET data
138  * stream.  This will be the address of the next character if
139  * the current address is a user data character, or it will
140  * be the address of the character following the TELNET command
141  * if the current address is a TELNET IAC ("I Am a Command")
142  * character.
143  */
144 char *
145 nextitem(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 	    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(void)
192 {
193     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 #ifdef	ENCRYPTION
199     thisitem = nclearto > netobuf ? nclearto : netobuf;
200 #else /* ENCRYPTION */
201     thisitem = netobuf;
202 #endif	/* ENCRYPTION */
203 
204     while ((next = nextitem(thisitem)) <= nbackp) {
205 	thisitem = next;
206     }
207 
208     /* Now, thisitem is first before/at boundary. */
209 
210 #ifdef	ENCRYPTION
211     good = nclearto > netobuf ? nclearto : netobuf;
212 #else /* ENCRYPTION */
213     good = netobuf;	/* where the good bytes go */
214 #endif	/* ENCRYPTION */
215 
216     while (nfrontp > thisitem) {
217 	if (wewant(thisitem)) {
218 	    int length;
219 
220 	    next = thisitem;
221 	    do {
222 		next = nextitem(next);
223 	    } while (wewant(next) && (nfrontp > next));
224 	    length = next-thisitem;
225 	    memmove(good, thisitem, length);
226 	    good += length;
227 	    thisitem = next;
228 	} else {
229 	    thisitem = nextitem(thisitem);
230 	}
231     }
232 
233     nbackp = netobuf;
234     nfrontp = good;		/* next byte to be sent */
235     neturg = 0;
236 }  /* end of netclear */
237 
238 /*
239  *  netflush
240  *		Send as much data as possible to the network,
241  *	handling requests for urgent data.
242  */
243 void
244 netflush(void)
245 {
246     int n;
247 
248     if ((n = nfrontp - nbackp) > 0) {
249 	DIAG(TD_REPORT,
250 	    { output_data("td: netflush %d chars\r\n", n);
251 	      n = nfrontp - nbackp;	/* re-compute count */
252 	    });
253 #ifdef	ENCRYPTION
254 	if (encrypt_output) {
255 		char *s = nclearto ? nclearto : nbackp;
256 		if (nfrontp - s > 0) {
257 			(*encrypt_output)((unsigned char *)s, nfrontp - s);
258 			nclearto = nfrontp;
259 		}
260 	}
261 #endif	/* ENCRYPTION */
262 	/*
263 	 * if no urgent data, or if the other side appears to be an
264 	 * old 4.2 client (and thus unable to survive TCP urgent data),
265 	 * write the entire buffer in non-OOB mode.
266 	 */
267 	if ((neturg == 0) || (not42 == 0)) {
268 	    n = write(net, nbackp, n);	/* normal write */
269 	} else {
270 	    n = neturg - nbackp;
271 	    /*
272 	     * In 4.2 (and 4.3) systems, there is some question about
273 	     * what byte in a sendOOB operation is the "OOB" data.
274 	     * To make ourselves compatible, we only send ONE byte
275 	     * out of band, the one WE THINK should be OOB (though
276 	     * we really have more the TCP philosophy of urgent data
277 	     * rather than the Unix philosophy of OOB data).
278 	     */
279 	    if (n > 1) {
280 		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */
281 	    } else {
282 		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */
283 	    }
284 	}
285     }
286     if (n < 0) {
287 	if (errno == EWOULDBLOCK || errno == EINTR)
288 		return;
289 	cleanup(0);
290     }
291     nbackp += n;
292 #ifdef	ENCRYPTION
293     if (nbackp > nclearto)
294 	nclearto = 0;
295 #endif	/* ENCRYPTION */
296     if (nbackp >= neturg) {
297 	neturg = 0;
298     }
299     if (nbackp == nfrontp) {
300 	nbackp = nfrontp = netobuf;
301 #ifdef	ENCRYPTION
302 	nclearto = 0;
303 #endif	/* ENCRYPTION */
304     }
305     return;
306 }  /* end of netflush */
307 
308 
309 /*
310  * writenet
311  *
312  * Just a handy little function to write a bit of raw data to the net.
313  * It will force a transmit of the buffer if necessary
314  *
315  * arguments
316  *    ptr - A pointer to a character string to write
317  *    len - How many bytes to write
318  */
319 void
320 writenet(unsigned char *ptr, int len)
321 {
322 	/* flush buffer if no room for new data) */
323 	if ((&netobuf[BUFSIZ] - nfrontp) < len) {
324 		/* if this fails, don't worry, buffer is a little big */
325 		netflush();
326 	}
327 
328 	memmove(nfrontp, ptr, len);
329 	nfrontp += len;
330 
331 }  /* end of writenet */
332 
333 
334 /*
335  * miscellaneous functions doing a variety of little jobs follow ...
336  */
337 void
338 fatal(int f, const char *msg)
339 {
340 	char buf[BUFSIZ];
341 
342 	(void)snprintf(buf, sizeof buf, "telnetd: %s.\r\n", msg);
343 #ifdef	ENCRYPTION
344 	if (encrypt_output) {
345 		/*
346 		 * Better turn off encryption first....
347 		 * Hope it flushes...
348 		 */
349 		encrypt_send_end();
350 		netflush();
351 	}
352 #endif	/* ENCRYPTION */
353 	(void)write(f, buf, (int)strlen(buf));
354 	sleep(1);	/*XXX*/
355 	exit(1);
356 }
357 
358 void
359 fatalperror(f, msg)
360 	int f;
361 	const char *msg;
362 {
363 	char buf[BUFSIZ];
364 
365 	(void)snprintf(buf, sizeof buf, "%s: %s", msg, strerror(errno));
366 	fatal(f, buf);
367 }
368 
369 char editedhost[MAXHOSTNAMELEN];
370 
371 void
372 edithost(char *pat, char *host)
373 {
374 	char *res = editedhost;
375 
376 	if (!pat)
377 		pat = "";
378 	while (*pat) {
379 		switch (*pat) {
380 
381 		case '#':
382 			if (*host)
383 				host++;
384 			break;
385 
386 		case '@':
387 			if (*host)
388 				*res++ = *host++;
389 			break;
390 
391 		default:
392 			*res++ = *pat;
393 			break;
394 		}
395 		if (res == &editedhost[sizeof editedhost - 1]) {
396 			*res = '\0';
397 			return;
398 		}
399 		pat++;
400 	}
401 	if (*host)
402 		(void) strncpy(res, host,
403 		    sizeof editedhost - (res - editedhost) -1);
404 	else
405 		*res = '\0';
406 	editedhost[sizeof editedhost - 1] = '\0';
407 }
408 
409 static char *putlocation;
410 
411 void
412 putstr(char *s)
413 {
414 
415 	while (*s)
416 		putchr(*s++);
417 }
418 
419 void
420 putchr(int cc)
421 {
422 	*putlocation++ = cc;
423 }
424 
425 /*
426  * This is split on two lines so that SCCS will not see the M
427  * between two % signs and expand it...
428  */
429 static char fmtstr[] = { "%l:%M\
430 %p on %A, %d %B %Y" };
431 
432 char *
433 putf(char *cp, char *where)
434 {
435 	char *slash;
436 	time_t t;
437 	char db[100];
438 	struct utsname utsinfo;
439 
440 	uname(&utsinfo);
441 
442 	putlocation = where;
443 
444 	while (*cp) {
445 		if (*cp != '%') {
446 			putchr(*cp++);
447 			continue;
448 		}
449 		switch (*++cp) {
450 
451 		case 't':
452 			if ((slash = strstr(line, "/pts/")) == NULL)
453 				slash = strrchr(line, '/');
454 			if (slash == (char *) 0)
455 				putstr(line);
456 			else
457 				putstr(&slash[1]);
458 			break;
459 
460 		case 'h':
461 			putstr(editedhost);
462 			break;
463 
464 		case 'd':
465 			(void)time(&t);
466 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
467 			putstr(db);
468 			break;
469 
470 		case '%':
471 			putchr('%');
472 			break;
473 
474 		case 's':
475 			putstr(utsinfo.sysname);
476 			break;
477 
478 		case 'm':
479 			putstr(utsinfo.machine);
480 			break;
481 
482 		case 'r':
483 			putstr(utsinfo.release);
484 			break;
485 
486 		case 'v':
487 			putstr(utsinfo.version);
488                         break;
489 		}
490 		cp++;
491 	}
492 
493 	return (putlocation);
494 }
495 
496 #ifdef DIAGNOSTICS
497 /*
498  * Print telnet options and commands in plain text, if possible.
499  */
500 void
501 printoption(const char *fmt, int option)
502 {
503 	if (TELOPT_OK(option))
504 		output_data("%s %s\r\n", fmt, TELOPT(option));
505 	else if (TELCMD_OK(option))
506 		output_data("%s %s\r\n", fmt, TELCMD(option));
507 	else
508 		output_data("%s %d\r\n", fmt, option);
509 	return;
510 }
511 
512 void
513 printsub(
514     int	   direction,	/* '<' or '>' */
515     unsigned char *pointer,	/* where suboption data sits */
516     int		   length)	/* length of suboption data */
517 {
518     int i = 0;
519 #if	defined(AUTHENTICATION) || defined(ENCRYPTION)
520     char buf[512];
521 #endif
522 
523 	if (!(diagnostic & TD_OPTIONS))
524 		return;
525 
526 	if (direction) {
527 	    output_data("td: %s suboption ",
528 	        direction == '<' ? "recv" : "send");
529 	    if (length >= 3) {
530 		int j;
531 
532 		i = pointer[length - 2];
533 		j = pointer[length - 1];
534 
535 		if (i != IAC || j != SE) {
536 		    output_data("(terminated by ");
537 		    if (TELOPT_OK(i))
538 			output_data("%s ", TELOPT(i));
539 		    else if (TELCMD_OK(i))
540 			output_data("%s ", TELCMD(i));
541 		    else
542 			output_data("%d ", i);
543 		    if (TELOPT_OK(j))
544 			output_data("%s", TELOPT(j));
545 		    else if (TELCMD_OK(j))
546 			output_data("%s", TELCMD(j));
547 		    else
548 			output_data("%d", j);
549 		    output_data(", not IAC SE!) ");
550 		}
551 	    }
552 	    length -= 2;
553 	}
554 	if (length < 1) {
555 	    output_data("(Empty suboption??\?)");
556 	    return;
557 	}
558 	switch (pointer[0]) {
559 	case TELOPT_TTYPE:
560 	    output_data("TERMINAL-TYPE ");
561 	    switch (pointer[1]) {
562 	    case TELQUAL_IS:
563 		output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
564 		break;
565 	    case TELQUAL_SEND:
566 		output_data("SEND");
567 		break;
568 	    default:
569 		output_data("- unknown qualifier %d (0x%x).",
570 		    pointer[1], pointer[1]);
571 	    }
572 	    break;
573 	case TELOPT_TSPEED:
574 	    output_data("TERMINAL-SPEED");
575 	    if (length < 2) {
576 		output_data(" (empty suboption??\?)");
577 		break;
578 	    }
579 	    switch (pointer[1]) {
580 	    case TELQUAL_IS:
581 		output_data(" IS %.*s", length-2, (char *)pointer+2);
582 		break;
583 	    default:
584 		if (pointer[1] == 1)
585 		    output_data(" SEND");
586 		else
587 		    output_data(" %d (unknown)", pointer[1]);
588 		for (i = 2; i < length; i++) {
589 		    output_data(" ?%d?", pointer[i]);
590 		}
591 		break;
592 	    }
593 	    break;
594 
595 	case TELOPT_LFLOW:
596 	    output_data("TOGGLE-FLOW-CONTROL");
597 	    if (length < 2) {
598 		output_data(" (empty suboption??\?)");
599 		break;
600 	    }
601 	    switch (pointer[1]) {
602 	    case LFLOW_OFF:
603 		output_data(" OFF"); break;
604 	    case LFLOW_ON:
605 		output_data(" ON"); break;
606 	    case LFLOW_RESTART_ANY:
607 		output_data(" RESTART-ANY"); break;
608 	    case LFLOW_RESTART_XON:
609 		output_data(" RESTART-XON"); break;
610 	    default:
611 		output_data(" %d (unknown)", pointer[1]);
612 	    }
613 	    for (i = 2; i < length; i++)
614 		output_data(" ?%d?", pointer[i]);
615 	    break;
616 
617 	case TELOPT_NAWS:
618 	    output_data("NAWS");
619 	    if (length < 2) {
620 		output_data(" (empty suboption??\?)");
621 		break;
622 	    }
623 	    if (length == 2) {
624 		output_data(" ?%d?", pointer[1]);
625 		break;
626 	    }
627 	    output_data(" %d %d (%d)",
628 		pointer[1], pointer[2],
629 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
630 	    if (length == 4) {
631 		output_data(" ?%d?", pointer[3]);
632 		break;
633 	    }
634 	    output_data(" %d %d (%d)", pointer[3], pointer[4],
635 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
636 	    for (i = 5; i < length; i++) {
637 		output_data(" ?%d?", pointer[i]);
638 	    }
639 	    break;
640 
641 	case TELOPT_LINEMODE:
642 	    output_data("LINEMODE ");
643 	    if (length < 2) {
644 		output_data(" (empty suboption??\?)");
645 		break;
646 	    }
647 	    switch (pointer[1]) {
648 	    case WILL:
649 		output_data("WILL ");
650 		goto common;
651 	    case WONT:
652 		output_data("WONT ");
653 		goto common;
654 	    case DO:
655 		output_data("DO ");
656 		goto common;
657 	    case DONT:
658 		output_data("DONT ");
659 	    common:
660 		if (length < 3) {
661 		    output_data("(no option??\?)");
662 		    break;
663 		}
664 		switch (pointer[2]) {
665 		case LM_FORWARDMASK:
666 		    output_data("Forward Mask");
667 		    for (i = 3; i < length; i++)
668 			output_data(" %x", pointer[i]);
669 		    break;
670 		default:
671 		    output_data("%d (unknown)", pointer[2]);
672 		    for (i = 3; i < length; i++)
673 			output_data(" %d", pointer[i]);
674 		    break;
675 		}
676 		break;
677 
678 	    case LM_SLC:
679 		output_data("SLC");
680 		for (i = 2; i < length - 2; i += 3) {
681 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
682 			output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
683 		    else
684 			output_data(" %d", pointer[i+SLC_FUNC]);
685 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
686 		    case SLC_NOSUPPORT:
687 			output_data(" NOSUPPORT"); break;
688 		    case SLC_CANTCHANGE:
689 			output_data(" CANTCHANGE"); break;
690 		    case SLC_VARIABLE:
691 			output_data(" VARIABLE"); break;
692 		    case SLC_DEFAULT:
693 			output_data(" DEFAULT"); break;
694 		    }
695 		    output_data("%s%s%s",
696 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
697 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
698 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
699 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
700 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
701 			output_data("(0x%x)", pointer[i+SLC_FLAGS]);
702 		    }
703 		    output_data(" %d;", pointer[i+SLC_VALUE]);
704 		    if ((pointer[i+SLC_VALUE] == IAC) &&
705 			(pointer[i+SLC_VALUE+1] == IAC))
706 				i++;
707 		}
708 		for (; i < length; i++)
709 		    output_data(" ?%d?", pointer[i]);
710 		break;
711 
712 	    case LM_MODE:
713 		output_data("MODE ");
714 		if (length < 3) {
715 		    output_data("(no mode??\?)");
716 		    break;
717 		}
718 		{
719 		    char tbuf[32];
720 
721 		    (void)snprintf(tbuf, sizeof tbuf, "%s%s%s%s%s",
722 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
723 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
724 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
725 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
726 			pointer[2]&MODE_ACK ? "|ACK" : "");
727 		    output_data("%s", tbuf[1] ? &tbuf[1] : "0");
728 		}
729 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK))
730 		    output_data(" (0x%x)", pointer[2]);
731 		for (i = 3; i < length; i++)
732 		    output_data(" ?0x%x?", pointer[i]);
733 		break;
734 	    default:
735 		output_data("%d (unknown)", pointer[1]);
736 		for (i = 2; i < length; i++)
737 		    output_data(" %d", pointer[i]);
738 	    }
739 	    break;
740 
741 	case TELOPT_STATUS: {
742 	    char *cp;
743 	    int j, k;
744 
745 	    output_data("STATUS");
746 
747 	    switch (pointer[1]) {
748 	    default:
749 		if (pointer[1] == TELQUAL_SEND)
750 		    output_data(" SEND");
751 		else
752 		    output_data(" %d (unknown)", pointer[1]);
753 		for (i = 2; i < length; i++)
754 		    output_data(" ?%d?", pointer[i]);
755 		break;
756 	    case TELQUAL_IS:
757 		output_data(" IS\r\n");
758 
759 		for (i = 2; i < length; i++) {
760 		    switch(pointer[i]) {
761 		    case DO:	cp = "DO"; goto common2;
762 		    case DONT:	cp = "DONT"; goto common2;
763 		    case WILL:	cp = "WILL"; goto common2;
764 		    case WONT:	cp = "WONT"; goto common2;
765 		    common2:
766 			i++;
767 			if (TELOPT_OK(pointer[i]))
768 			    output_data(" %s %s", cp, TELOPT(pointer[i]));
769 			else
770 			    output_data(" %s %d", cp, pointer[i]);
771 
772 			output_data("\r\n");
773 			break;
774 
775 		    case SB:
776 			output_data(" SB ");
777 			i++;
778 			j = k = i;
779 			while (j < length) {
780 			    if (pointer[j] == SE) {
781 				if (j+1 == length)
782 				    break;
783 				if (pointer[j+1] == SE)
784 				    j++;
785 				else
786 				    break;
787 			    }
788 			    pointer[k++] = pointer[j++];
789 			}
790 			printsub(0, &pointer[i], k - i);
791 			if (i < length) {
792 			    output_data(" SE");
793 			    i = j;
794 			} else
795 			    i = j - 1;
796 
797 			output_data("\r\n");
798 
799 			break;
800 
801 		    default:
802 			output_data(" %d", pointer[i]);
803 			break;
804 		    }
805 		}
806 		break;
807 	    }
808 	    break;
809 	  }
810 
811 	case TELOPT_XDISPLOC:
812 	    output_data("X-DISPLAY-LOCATION ");
813 	    switch (pointer[1]) {
814 	    case TELQUAL_IS:
815 		output_data("IS \"%.*s\"", length - 2, (char *)pointer + 2);
816 		break;
817 	    case TELQUAL_SEND:
818 		output_data("SEND");
819 		break;
820 	    default:
821 		output_data("- unknown qualifier %d (0x%x).",
822 		    pointer[1], pointer[1]);
823 	    }
824 	    break;
825 
826 	case TELOPT_NEW_ENVIRON:
827 	    output_data("NEW-ENVIRON ");
828 	    goto env_common1;
829 	case TELOPT_OLD_ENVIRON:
830 	    output_data("OLD-ENVIRON");
831 	env_common1:
832 	    switch (pointer[1]) {
833 	    case TELQUAL_IS:
834 		output_data("IS ");
835 		goto env_common;
836 	    case TELQUAL_SEND:
837 		output_data("SEND ");
838 		goto env_common;
839 	    case TELQUAL_INFO:
840 		output_data("INFO ");
841 	    env_common:
842 		{
843 		    int noquote = 2;
844 		    for (i = 2; i < length; i++ ) {
845 			switch (pointer[i]) {
846 			case NEW_ENV_VAR:
847 			    output_data("%s", "\" VAR " + noquote);
848 			    noquote = 2;
849 			    break;
850 
851 			case NEW_ENV_VALUE:
852 			    output_data("%s", "\" VALUE " + noquote);
853 			    noquote = 2;
854 			    break;
855 
856 			case ENV_ESC:
857 			    output_data("%s", "\" ESC " + noquote);
858 			    noquote = 2;
859 			    break;
860 
861 			case ENV_USERVAR:
862 			    output_data("%s", "\" USERVAR " + noquote);
863 			    noquote = 2;
864 			    break;
865 
866 			default:
867 			    if (isprint(pointer[i]) && pointer[i] != '"') {
868 				if (noquote) {
869 				    output_data("\"");
870 				    noquote = 0;
871 				}
872 				output_data("%c", pointer[i]);
873 			    } else {
874 				output_data("\" %03o " + noquote, pointer[i]);
875 				noquote = 2;
876 			    }
877 			    break;
878 			}
879 		    }
880 		    if (!noquote)
881 			output_data("\"");
882 		    break;
883 		}
884 	    }
885 	    break;
886 
887 #ifdef AUTHENTICATION
888 	case TELOPT_AUTHENTICATION:
889 	    output_data("AUTHENTICATION");
890 
891 	    if (length < 2) {
892 		output_data(" (empty suboption??\?)");
893 		break;
894 	    }
895 	    switch (pointer[1]) {
896 	    case TELQUAL_REPLY:
897 	    case TELQUAL_IS:
898 		output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
899 		    "IS" : "REPLY");
900 		if (AUTHTYPE_NAME_OK(pointer[2]))
901 		    output_data("%s ", AUTHTYPE_NAME(pointer[2]));
902 		else
903 		    output_data("%d ", pointer[2]);
904 		if (length < 3) {
905 		    output_data("(partial suboption??\?)");
906 		    break;
907 		}
908 		output_data("%s|%s",
909 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
910 			"CLIENT" : "SERVER",
911 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
912 			"MUTUAL" : "ONE-WAY");
913 
914 		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
915 		output_data("%s", buf);
916 		break;
917 
918 	    case TELQUAL_SEND:
919 		i = 2;
920 		output_data(" SEND ");
921 		while (i < length) {
922 		    if (AUTHTYPE_NAME_OK(pointer[i]))
923 			output_data("%s ", AUTHTYPE_NAME(pointer[i]));
924 		    else
925 			output_data("%d ", pointer[i]);
926 		    if (++i >= length) {
927 			output_data("(partial suboption??\?)");
928 			break;
929 		    }
930 		    output_data("%s|%s ",
931 			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
932 							"CLIENT" : "SERVER",
933 			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
934 							"MUTUAL" : "ONE-WAY");
935 		    ++i;
936 		}
937 		break;
938 
939 	    case TELQUAL_NAME:
940 		i = 2;
941 		output_data(" NAME \"");
942 		while (i < length) {
943 		    if (isprint(pointer[i]))
944 			output_data("%c", pointer[i++]);
945 		    else
946 			output_data("\"%03o\"",pointer[i++]);
947 		}
948 		output_data("\"");
949 		break;
950 
951 	    default:
952 		for (i = 2; i < length; i++)
953 		    output_data(" ?%d?", pointer[i]);
954 		break;
955 	    }
956 	    break;
957 #endif
958 
959 #ifdef	ENCRYPTION
960 	case TELOPT_ENCRYPT:
961 	    output_data("ENCRYPT");
962 	    if (length < 2) {
963 		output_data(" (empty suboption??\?)");
964 		break;
965 	    }
966 	    switch (pointer[1]) {
967 	    case ENCRYPT_START:
968 		output_data(" START");
969 		break;
970 
971 	    case ENCRYPT_END:
972 		output_data(" END");
973 		break;
974 
975 	    case ENCRYPT_REQSTART:
976 		output_data(" REQUEST-START");
977 		break;
978 
979 	    case ENCRYPT_REQEND:
980 		output_data(" REQUEST-END");
981 		break;
982 
983 	    case ENCRYPT_IS:
984 	    case ENCRYPT_REPLY:
985 		output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
986 		    "IS" : "REPLY");
987 		if (length < 3) {
988 			output_data(" (partial suboption??\?)");
989 			break;
990 		}
991 		if (ENCTYPE_NAME_OK(pointer[2]))
992 			output_data("%s ", ENCTYPE_NAME(pointer[2]));
993 		else
994 			output_data(" %d (unknown)", pointer[2]);
995 
996 		encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
997 		output_data("%s", buf);
998 		break;
999 
1000 	    case ENCRYPT_SUPPORT:
1001 		i = 2;
1002 		output_data(" SUPPORT ");
1003 		while (i < length) {
1004 			if (ENCTYPE_NAME_OK(pointer[i]))
1005 				output_data("%s ", ENCTYPE_NAME(pointer[i]));
1006 			else
1007 				output_data("%d ", pointer[i]);
1008 			i++;
1009 		}
1010 		break;
1011 
1012 	    case ENCRYPT_ENC_KEYID:
1013 		output_data(" ENC_KEYID");
1014 		goto encommon;
1015 
1016 	    case ENCRYPT_DEC_KEYID:
1017 		output_data(" DEC_KEYID");
1018 		goto encommon;
1019 
1020 	    default:
1021 		output_data(" %d (unknown)", pointer[1]);
1022 	    encommon:
1023 		for (i = 2; i < length; i++)
1024 			output_data(" %d", pointer[i]);
1025 		break;
1026 	    }
1027 	    break;
1028 #endif	/* ENCRYPTION */
1029 
1030 	default:
1031 	    if (TELOPT_OK(pointer[0]))
1032 		output_data("%s (unknown)", TELOPT(pointer[0]));
1033 	    else
1034 		output_data("%d (unknown)", pointer[i]);
1035 	    for (i = 1; i < length; i++)
1036 		output_data(" %d", pointer[i]);
1037 	    break;
1038 	}
1039 	output_data("\r\n");
1040 }
1041 
1042 /*
1043  * Dump a data buffer in hex and ascii to the output data stream.
1044  */
1045 void
1046 printdata(char *tag, char *ptr, int cnt)
1047 {
1048 	int i;
1049 	char xbuf[30];
1050 
1051 	while (cnt) {
1052 		/* flush net output buffer if no room for new data) */
1053 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1054 			netflush();
1055 		}
1056 
1057 		/* add a line of output */
1058 		output_data("%s: ", tag);
1059 		for (i = 0; i < 20 && cnt; i++) {
1060 			output_data("%02x", *ptr);
1061 			if (isprint((unsigned char)*ptr)) {
1062 				xbuf[i] = *ptr;
1063 			} else {
1064 				xbuf[i] = '.';
1065 			}
1066 			if (i % 2)
1067 				output_data(" ");
1068 			cnt--;
1069 			ptr++;
1070 		}
1071 		xbuf[i] = '\0';
1072 		output_data(" %s\r\n", xbuf);
1073 	}
1074 }
1075 #endif /* DIAGNOSTICS */
1076