xref: /dragonfly/libexec/telnetd/utility.c (revision 2b3f93ea)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)utility.c	8.4 (Berkeley) 5/30/95
30  * $FreeBSD: src/crypto/telnet/telnetd/utility.c,v 1.5.2.4 2002/04/13 10:59:09 markm Exp $
31  */
32 
33 #if defined(__FreeBSD__) || defined(__DragonFly__)
34 #include <locale.h>
35 #include <sys/utsname.h>
36 #endif
37 #include <string.h>
38 #define PRINTOPTIONS
39 #include "telnetd.h"
40 
41 #ifdef	AUTHENTICATION
42 #include <libtelnet/auth.h>
43 #endif
44 #ifdef	ENCRYPTION
45 #include <libtelnet/encrypt.h>
46 #endif
47 
48 extern char	line[16];
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 > 0) {
69 	netflush();
70     }
71     ncc = read(net, netibuf, sizeof netibuf);
72     if (ncc < 0) {
73 	syslog(LOG_INFO, "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)
93 {
94     static struct timeval timeout = { 0, 0 };
95     fd_set	excepts;
96     int value;
97 
98     do {
99 	FD_ZERO(&excepts);
100 	FD_SET(s, &excepts);
101 	memset((char *)&timeout, 0, sizeof timeout);
102 	value = select(s+1, NULL, NULL, &excepts, &timeout);
103     } while ((value == -1) && (errno == EINTR));
104 
105     if (value < 0) {
106 	fatalperror(pty, "select");
107     }
108     if (FD_ISSET(s, &excepts)) {
109 	return 1;
110     } else {
111 	return 0;
112     }
113 }
114 
115 void
116 ptyflush(void)
117 {
118 	int n;
119 
120 	if ((n = pfrontp - pbackp) > 0) {
121 		DIAG(TD_REPORT | TD_PTYDATA,
122 		    output_data("td: ptyflush %d chars\r\n", n));
123 		DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
124 		n = write(pty, pbackp, n);
125 	}
126 	if (n < 0) {
127 		if (errno == EWOULDBLOCK || errno == EINTR)
128 			return;
129 		cleanup(0);
130 	}
131 	pbackp += n;
132 	if (pbackp == pfrontp)
133 		pbackp = pfrontp = ptyobuf;
134 }
135 
136 /*
137  * nextitem()
138  *
139  *	Return the address of the next "item" in the TELNET data
140  * stream.  This will be the address of the next character if
141  * the current address is a user data character, or it will
142  * be the address of the character following the TELNET command
143  * if the current address is a TELNET IAC ("I Am a Command")
144  * character.
145  */
146 static char *
147 nextitem(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 	    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  * netclear()
177  *
178  *	We are about to do a TELNET SYNCH operation.  Clear
179  * the path to the network.
180  *
181  *	Things are a bit tricky since we may have sent the first
182  * byte or so of a previous TELNET command into the network.
183  * So, we have to scan the network buffer from the beginning
184  * until we are up to where we want to be.
185  *
186  *	A side effect of what we do, just to keep things
187  * simple, is to clear the urgent data pointer.  The principal
188  * caller should be setting the urgent data pointer AFTER calling
189  * us in any case.
190  */
191 void
192 netclear(void)
193 {
194     char *thisitem, *next;
195     char *good;
196 #define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \
197 				((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
198 
199 #ifdef	ENCRYPTION
200     thisitem = nclearto > netobuf ? nclearto : netobuf;
201 #else	/* ENCRYPTION */
202     thisitem = netobuf;
203 #endif	/* ENCRYPTION */
204 
205     while ((next = nextitem(thisitem)) <= nbackp) {
206 	thisitem = next;
207     }
208 
209     /* Now, thisitem is first before/at boundary. */
210 
211 #ifdef	ENCRYPTION
212     good = nclearto > netobuf ? nclearto : netobuf;
213 #else	/* ENCRYPTION */
214     good = netobuf;	/* where the good bytes go */
215 #endif	/* ENCRYPTION */
216 
217     while (nfrontp > thisitem) {
218 	if (wewant(thisitem)) {
219 	    int length;
220 
221 	    next = thisitem;
222 	    do {
223 		next = nextitem(next);
224 	    } while (wewant(next) && (nfrontp > next));
225 	    length = next-thisitem;
226 	    memmove(good, thisitem, length);
227 	    good += length;
228 	    thisitem = next;
229 	} else {
230 	    thisitem = nextitem(thisitem);
231 	}
232     }
233 
234     nbackp = netobuf;
235     nfrontp = good;		/* next byte to be sent */
236     neturg = 0;
237 }  /* end of netclear */
238 
239 /*
240  *  netflush
241  *		Send as much data as possible to the network,
242  *	handling requests for urgent data.
243  */
244 void
245 netflush(void)
246 {
247     int n;
248     extern int not42;
249 
250     while ((n = nfrontp - nbackp) > 0) {
251 #if 0
252 	/* XXX This causes output_data() to recurse and die */
253 	DIAG(TD_REPORT, {
254 	    n += output_data("td: netflush %d chars\r\n", n);
255 	});
256 #endif
257 #ifdef	ENCRYPTION
258 	if (encrypt_output) {
259 		char *s = nclearto ? nclearto : nbackp;
260 		if (nfrontp - s > 0) {
261 			(*encrypt_output)((unsigned char *)s, nfrontp-s);
262 			nclearto = nfrontp;
263 		}
264 	}
265 #endif	/* ENCRYPTION */
266 	/*
267 	 * if no urgent data, or if the other side appears to be an
268 	 * old 4.2 client (and thus unable to survive TCP urgent data),
269 	 * write the entire buffer in non-OOB mode.
270 	 */
271 	if ((neturg == 0) || (not42 == 0)) {
272 	    n = write(net, nbackp, n);	/* normal write */
273 	} else {
274 	    n = neturg - nbackp;
275 	    /*
276 	     * In 4.2 (and 4.3) systems, there is some question about
277 	     * what byte in a sendOOB operation is the "OOB" data.
278 	     * To make ourselves compatible, we only send ONE byte
279 	     * out of band, the one WE THINK should be OOB (though
280 	     * we really have more the TCP philosophy of urgent data
281 	     * rather than the Unix philosophy of OOB data).
282 	     */
283 	    if (n > 1) {
284 		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */
285 	    } else {
286 		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */
287 	    }
288 	}
289 	if (n == -1) {
290 	    if (errno == EWOULDBLOCK || errno == EINTR)
291 		continue;
292 	    cleanup(0);
293 	    /* NOTREACHED */
294 	}
295 	nbackp += n;
296 #ifdef	ENCRYPTION
297 	if (nbackp > nclearto)
298 	    nclearto = 0;
299 #endif	/* ENCRYPTION */
300 	if (nbackp >= neturg) {
301 	    neturg = 0;
302 	}
303 	if (nbackp == nfrontp) {
304 	    nbackp = nfrontp = netobuf;
305 #ifdef	ENCRYPTION
306 	    nclearto = 0;
307 #endif	/* ENCRYPTION */
308 	}
309     }
310     return;
311 }  /* end of netflush */
312 
313 
314 /*
315  * miscellaneous functions doing a variety of little jobs follow ...
316  */
317 
318 
319 void
320 fatalmsg(int f, const char *msg)
321 {
322 	char buf[BUFSIZ];
323 
324 	(void) snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg);
325 #ifdef	ENCRYPTION
326 	if (encrypt_output) {
327 		/*
328 		 * Better turn off encryption first....
329 		 * Hope it flushes...
330 		 */
331 		encrypt_send_end();
332 		netflush();
333 	}
334 #endif	/* ENCRYPTION */
335 	(void) write(f, buf, (int)strlen(buf));
336 	sleep(1);	/*XXX*/
337 	exit(1);
338 }
339 
340 void
341 fatalperror(int f, const char *msg)
342 {
343 	char buf[BUFSIZ];
344 
345 	(void) snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(errno));
346 	fatalmsg(f, buf);
347 }
348 
349 char editedhost[32];
350 
351 void
352 edithost(char *pat, char *host)
353 {
354 	char *res = editedhost;
355 
356 	if (!pat)
357 		pat = strdup("");
358 	while (*pat) {
359 		switch (*pat) {
360 
361 		case '#':
362 			if (*host)
363 				host++;
364 			break;
365 
366 		case '@':
367 			if (*host)
368 				*res++ = *host++;
369 			break;
370 
371 		default:
372 			*res++ = *pat;
373 			break;
374 		}
375 		if (res == &editedhost[sizeof editedhost - 1]) {
376 			*res = '\0';
377 			return;
378 		}
379 		pat++;
380 	}
381 	if (*host)
382 		(void) strncpy(res, host,
383 				sizeof editedhost - (res - editedhost) -1);
384 	else
385 		*res = '\0';
386 	editedhost[sizeof editedhost - 1] = '\0';
387 }
388 
389 static char *putlocation;
390 
391 static void
392 putstr(const char *s)
393 {
394 
395 	while (*s)
396 		putchr(*s++);
397 }
398 
399 void
400 putchr(int cc)
401 {
402 	*putlocation++ = cc;
403 }
404 
405 #if defined(__FreeBSD__) || defined(__DragonFly__)
406 static char fmtstr[] = { "%+" };
407 #else
408 static char fmtstr[] = { "%l:%M%P on %A, %d %B %Y" };
409 #endif
410 
411 void
412 putf(char *cp, char *where)
413 {
414 	char *slash;
415 	time_t t;
416 	char db[100];
417 #if defined(__FreeBSD__) || defined(__DragonFly__)
418 	static struct utsname kerninfo;
419 
420 	if (!*kerninfo.sysname)
421 		uname(&kerninfo);
422 #endif
423 
424 	putlocation = where;
425 
426 	while (*cp) {
427 		if (*cp =='\n') {
428 			putstr("\r\n");
429 			cp++;
430 			continue;
431 		} else 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 = strchr(line+1, '/');
441 #else
442 			slash = strrchr(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 #if defined(__FreeBSD__) || defined(__DragonFly__)
456 			setlocale(LC_TIME, "");
457 #endif
458 			(void)time(&t);
459 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
460 			putstr(db);
461 			break;
462 
463 #if defined(__FreeBSD__) || defined(__DragonFly__)
464 		case 's':
465 			putstr(kerninfo.sysname);
466 			break;
467 
468 		case 'm':
469 			putstr(kerninfo.machine);
470 			break;
471 
472 		case 'r':
473 			putstr(kerninfo.release);
474 			break;
475 
476 		case 'v':
477 			putstr(kerninfo.version);
478 			break;
479 #endif
480 
481 		case '%':
482 			putchr('%');
483 			break;
484 		}
485 		cp++;
486 	}
487 }
488 
489 #ifdef DIAGNOSTICS
490 /*
491  * Print telnet options and commands in plain text, if possible.
492  */
493 void
494 printoption(const char *fmt, int option)
495 {
496 	if (TELOPT_OK(option))
497 		output_data("%s %s\r\n", fmt, TELOPT(option));
498 	else if (TELCMD_OK(option))
499 		output_data("%s %s\r\n", fmt, TELCMD(option));
500 	else
501 		output_data("%s %d\r\n", fmt, option);
502 	return;
503 }
504 
505 void
506 printsub(char direction, unsigned char *pointer, int length)
507 {
508     int i = 0;
509 
510 	if (!(diagnostic & TD_OPTIONS))
511 		return;
512 
513 	if (direction) {
514 	    output_data("td: %s suboption ",
515 					direction == '<' ? "recv" : "send");
516 	    if (length >= 3) {
517 		int j;
518 
519 		i = pointer[length-2];
520 		j = pointer[length-1];
521 
522 		if (i != IAC || j != SE) {
523 		    output_data("(terminated by ");
524 		    if (TELOPT_OK(i))
525 			output_data("%s ", TELOPT(i));
526 		    else if (TELCMD_OK(i))
527 			output_data("%s ", TELCMD(i));
528 		    else
529 			output_data("%d ", i);
530 		    if (TELOPT_OK(j))
531 			output_data("%s", TELOPT(j));
532 		    else if (TELCMD_OK(j))
533 			output_data("%s", TELCMD(j));
534 		    else
535 			output_data("%d", j);
536 		    output_data(", not IAC SE!) ");
537 		}
538 	    }
539 	    length -= 2;
540 	}
541 	if (length < 1) {
542 	    output_data("(Empty suboption??\?)");
543 	    return;
544 	}
545 	switch (pointer[0]) {
546 	case TELOPT_TTYPE:
547 	    output_data("TERMINAL-TYPE ");
548 	    switch (pointer[1]) {
549 	    case TELQUAL_IS:
550 		output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
551 		break;
552 	    case TELQUAL_SEND:
553 		output_data("SEND");
554 		break;
555 	    default:
556 		output_data(
557 				"- unknown qualifier %d (0x%x).",
558 				pointer[1], pointer[1]);
559 	    }
560 	    break;
561 	case TELOPT_TSPEED:
562 	    output_data("TERMINAL-SPEED");
563 	    if (length < 2) {
564 		output_data(" (empty suboption??\?)");
565 		break;
566 	    }
567 	    switch (pointer[1]) {
568 	    case TELQUAL_IS:
569 		output_data(" IS %.*s", length-2, (char *)pointer+2);
570 		break;
571 	    default:
572 		if (pointer[1] == 1)
573 		    output_data(" SEND");
574 		else
575 		    output_data(" %d (unknown)", pointer[1]);
576 		for (i = 2; i < length; i++) {
577 		    output_data(" ?%d?", pointer[i]);
578 		}
579 		break;
580 	    }
581 	    break;
582 
583 	case TELOPT_LFLOW:
584 	    output_data("TOGGLE-FLOW-CONTROL");
585 	    if (length < 2) {
586 		output_data(" (empty suboption??\?)");
587 		break;
588 	    }
589 	    switch (pointer[1]) {
590 	    case LFLOW_OFF:
591 		output_data(" OFF"); break;
592 	    case LFLOW_ON:
593 		output_data(" ON"); break;
594 	    case LFLOW_RESTART_ANY:
595 		output_data(" RESTART-ANY"); break;
596 	    case LFLOW_RESTART_XON:
597 		output_data(" RESTART-XON"); break;
598 	    default:
599 		output_data(" %d (unknown)", pointer[1]);
600 	    }
601 	    for (i = 2; i < length; i++) {
602 		output_data(" ?%d?", pointer[i]);
603 	    }
604 	    break;
605 
606 	case TELOPT_NAWS:
607 	    output_data("NAWS");
608 	    if (length < 2) {
609 		output_data(" (empty suboption??\?)");
610 		break;
611 	    }
612 	    if (length == 2) {
613 		output_data(" ?%d?", pointer[1]);
614 		break;
615 	    }
616 	    output_data(" %d %d (%d)",
617 		pointer[1], pointer[2],
618 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
619 	    if (length == 4) {
620 		output_data(" ?%d?", pointer[3]);
621 		break;
622 	    }
623 	    output_data(" %d %d (%d)",
624 		pointer[3], pointer[4],
625 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
626 	    for (i = 5; i < length; i++) {
627 		output_data(" ?%d?", pointer[i]);
628 	    }
629 	    break;
630 
631 	case TELOPT_LINEMODE:
632 	    output_data("LINEMODE ");
633 	    if (length < 2) {
634 		output_data(" (empty suboption??\?)");
635 		break;
636 	    }
637 	    switch (pointer[1]) {
638 	    case WILL:
639 		output_data("WILL ");
640 		goto common;
641 	    case WONT:
642 		output_data("WONT ");
643 		goto common;
644 	    case DO:
645 		output_data("DO ");
646 		goto common;
647 	    case DONT:
648 		output_data("DONT ");
649 	    common:
650 		if (length < 3) {
651 		    output_data("(no option??\?)");
652 		    break;
653 		}
654 		switch (pointer[2]) {
655 		case LM_FORWARDMASK:
656 		    output_data("Forward Mask");
657 		    for (i = 3; i < length; i++) {
658 			output_data(" %x", pointer[i]);
659 		    }
660 		    break;
661 		default:
662 		    output_data("%d (unknown)", pointer[2]);
663 		    for (i = 3; i < length; i++) {
664 			output_data(" %d", pointer[i]);
665 		    }
666 		    break;
667 		}
668 		break;
669 
670 	    case LM_SLC:
671 		output_data("SLC");
672 		for (i = 2; i < length - 2; i += 3) {
673 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
674 			output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
675 		    else
676 			output_data(" %d", pointer[i+SLC_FUNC]);
677 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
678 		    case SLC_NOSUPPORT:
679 			output_data(" NOSUPPORT"); break;
680 		    case SLC_CANTCHANGE:
681 			output_data(" CANTCHANGE"); break;
682 		    case SLC_VARIABLE:
683 			output_data(" VARIABLE"); break;
684 		    case SLC_DEFAULT:
685 			output_data(" DEFAULT"); break;
686 		    }
687 		    output_data("%s%s%s",
688 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
689 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
690 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
691 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
692 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
693 			output_data("(0x%x)", pointer[i+SLC_FLAGS]);
694 		    }
695 		    output_data(" %d;", pointer[i+SLC_VALUE]);
696 		    if ((pointer[i+SLC_VALUE] == IAC) &&
697 			(pointer[i+SLC_VALUE+1] == IAC))
698 				i++;
699 		}
700 		for (; i < length; i++) {
701 		    output_data(" ?%d?", pointer[i]);
702 		}
703 		break;
704 
705 	    case LM_MODE:
706 		output_data("MODE ");
707 		if (length < 3) {
708 		    output_data("(no mode??\?)");
709 		    break;
710 		}
711 		{
712 		    char tbuf[32];
713 		    sprintf(tbuf, "%s%s%s%s%s",
714 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
715 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
716 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
717 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
718 			pointer[2]&MODE_ACK ? "|ACK" : "");
719 		    output_data("%s", tbuf[1] ? &tbuf[1] : "0");
720 		}
721 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
722 		    output_data(" (0x%x)", pointer[2]);
723 		}
724 		for (i = 3; i < length; i++) {
725 		    output_data(" ?0x%x?", pointer[i]);
726 		}
727 		break;
728 	    default:
729 		output_data("%d (unknown)", pointer[1]);
730 		for (i = 2; i < length; i++) {
731 		    output_data(" %d", pointer[i]);
732 		}
733 	    }
734 	    break;
735 
736 	case TELOPT_STATUS: {
737 	    const char *cp;
738 	    int j, k;
739 
740 	    output_data("STATUS");
741 
742 	    switch (pointer[1]) {
743 	    default:
744 		if (pointer[1] == TELQUAL_SEND)
745 		    output_data(" SEND");
746 		else
747 		    output_data(" %d (unknown)", pointer[1]);
748 		for (i = 2; i < length; i++) {
749 		    output_data(" ?%d?", pointer[i]);
750 		}
751 		break;
752 	    case TELQUAL_IS:
753 		output_data(" IS\r\n");
754 
755 		for (i = 2; i < length; i++) {
756 		    switch(pointer[i]) {
757 		    case DO:	cp = "DO"; goto common2;
758 		    case DONT:	cp = "DONT"; goto common2;
759 		    case WILL:	cp = "WILL"; goto common2;
760 		    case WONT:	cp = "WONT"; goto common2;
761 		    common2:
762 			i++;
763 			if (TELOPT_OK(pointer[i]))
764 			    output_data(" %s %s", cp, TELOPT(pointer[i]));
765 			else
766 			    output_data(" %s %d", cp, pointer[i]);
767 
768 			output_data("\r\n");
769 			break;
770 
771 		    case SB:
772 			output_data(" SB ");
773 			i++;
774 			j = k = i;
775 			while (j < length) {
776 			    if (pointer[j] == SE) {
777 				if (j+1 == length)
778 				    break;
779 				if (pointer[j+1] == SE)
780 				    j++;
781 				else
782 				    break;
783 			    }
784 			    pointer[k++] = pointer[j++];
785 			}
786 			printsub(0, &pointer[i], k - i);
787 			if (i < length) {
788 			    output_data(" SE");
789 			    i = j;
790 			} else
791 			    i = j - 1;
792 
793 			output_data("\r\n");
794 
795 			break;
796 
797 		    default:
798 			output_data(" %d", pointer[i]);
799 			break;
800 		    }
801 		}
802 		break;
803 	    }
804 	    break;
805 	  }
806 
807 	case TELOPT_XDISPLOC:
808 	    output_data("X-DISPLAY-LOCATION ");
809 	    switch (pointer[1]) {
810 	    case TELQUAL_IS:
811 		output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
812 		break;
813 	    case TELQUAL_SEND:
814 		output_data("SEND");
815 		break;
816 	    default:
817 		output_data("- unknown qualifier %d (0x%x).",
818 				pointer[1], pointer[1]);
819 	    }
820 	    break;
821 
822 	case TELOPT_NEW_ENVIRON:
823 	    output_data("NEW-ENVIRON ");
824 	    goto env_common1;
825 	case TELOPT_OLD_ENVIRON:
826 	    output_data("OLD-ENVIRON");
827 	env_common1:
828 	    switch (pointer[1]) {
829 	    case TELQUAL_IS:
830 		output_data("IS ");
831 		goto env_common;
832 	    case TELQUAL_SEND:
833 		output_data("SEND ");
834 		goto env_common;
835 	    case TELQUAL_INFO:
836 		output_data("INFO ");
837 	    env_common:
838 		{
839 		    int noquote = 2;
840 		    for (i = 2; i < length; i++ ) {
841 			switch (pointer[i]) {
842 			case NEW_ENV_VAR:
843 			    output_data("%s", "\" VAR " + noquote);
844 			    noquote = 2;
845 			    break;
846 
847 			case NEW_ENV_VALUE:
848 			    output_data("%s", "\" VALUE " + noquote);
849 			    noquote = 2;
850 			    break;
851 
852 			case ENV_ESC:
853 			    output_data("%s", "\" ESC " + noquote);
854 			    noquote = 2;
855 			    break;
856 
857 			case ENV_USERVAR:
858 			    output_data("%s", "\" USERVAR " + noquote);
859 			    noquote = 2;
860 			    break;
861 
862 			default:
863 			    if (isprint(pointer[i]) && pointer[i] != '"') {
864 				if (noquote) {
865 				    output_data("\"");
866 				    noquote = 0;
867 				}
868 				output_data("%c", pointer[i]);
869 			    } else {
870 				output_data("\" %03o " + noquote,
871 							pointer[i]);
872 				noquote = 2;
873 			    }
874 			    break;
875 			}
876 		    }
877 		    if (!noquote)
878 			output_data("\"");
879 		    break;
880 		}
881 	    }
882 	    break;
883 
884 #ifdef	AUTHENTICATION
885 	case TELOPT_AUTHENTICATION:
886 	    output_data("AUTHENTICATION");
887 
888 	    if (length < 2) {
889 		output_data(" (empty suboption??\?)");
890 		break;
891 	    }
892 	    switch (pointer[1]) {
893 	    case TELQUAL_REPLY:
894 	    case TELQUAL_IS:
895 		output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
896 							"IS" : "REPLY");
897 		if (AUTHTYPE_NAME_OK(pointer[2]))
898 		    output_data("%s ", AUTHTYPE_NAME(pointer[2]));
899 		else
900 		    output_data("%d ", pointer[2]);
901 		if (length < 3) {
902 		    output_data("(partial suboption??\?)");
903 		    break;
904 		}
905 		output_data("%s|%s",
906 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
907 			"CLIENT" : "SERVER",
908 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
909 			"MUTUAL" : "ONE-WAY");
910 
911     		{
912 		    char buf[512];
913 		    auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
914 		    output_data("%s", buf);
915 		}
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 		output_data(" NAME \"%.*s\"", length - 2, pointer + 2);
941 		break;
942 
943 	    default:
944 		    for (i = 2; i < length; i++) {
945 			output_data(" ?%d?", pointer[i]);
946 		    }
947 		    break;
948 	    }
949 	    break;
950 #endif
951 
952 #ifdef	ENCRYPTION
953 	case TELOPT_ENCRYPT:
954 	    output_data("ENCRYPT");
955 	    if (length < 2) {
956 		output_data(" (empty suboption??\?)");
957 		break;
958 	    }
959 	    switch (pointer[1]) {
960 	    case ENCRYPT_START:
961 		output_data(" START");
962 		break;
963 
964 	    case ENCRYPT_END:
965 		output_data(" END");
966 		break;
967 
968 	    case ENCRYPT_REQSTART:
969 		output_data(" REQUEST-START");
970 		break;
971 
972 	    case ENCRYPT_REQEND:
973 		output_data(" REQUEST-END");
974 		break;
975 
976 	    case ENCRYPT_IS:
977 	    case ENCRYPT_REPLY:
978 		output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
979 							"IS" : "REPLY");
980 		if (length < 3) {
981 		    output_data(" (partial suboption??\?)");
982 		    break;
983 		}
984 		if (ENCTYPE_NAME_OK(pointer[2]))
985 		    output_data("%s ", ENCTYPE_NAME(pointer[2]));
986 		else
987 		    output_data(" %d (unknown)", pointer[2]);
988 
989 		{
990 		    char buf[512];
991 		    encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
992 		    output_data("%s", buf);
993 		}
994 		break;
995 
996 	    case ENCRYPT_SUPPORT:
997 		i = 2;
998 		output_data(" SUPPORT ");
999 		while (i < length) {
1000 		    if (ENCTYPE_NAME_OK(pointer[i]))
1001 			output_data("%s ", ENCTYPE_NAME(pointer[i]));
1002 		    else
1003 			output_data("%d ", pointer[i]);
1004 		    i++;
1005 		}
1006 		break;
1007 
1008 	    case ENCRYPT_ENC_KEYID:
1009 		output_data(" ENC_KEYID");
1010 		goto encommon;
1011 
1012 	    case ENCRYPT_DEC_KEYID:
1013 		output_data(" DEC_KEYID");
1014 		goto encommon;
1015 
1016 	    default:
1017 		output_data(" %d (unknown)", pointer[1]);
1018 	    encommon:
1019 		for (i = 2; i < length; i++) {
1020 		    output_data(" %d", pointer[i]);
1021 		}
1022 		break;
1023 	    }
1024 	    break;
1025 #endif	/* ENCRYPTION */
1026 
1027 	default:
1028 	    if (TELOPT_OK(pointer[0]))
1029 		output_data("%s (unknown)", TELOPT(pointer[0]));
1030 	    else
1031 		output_data("%d (unknown)", pointer[i]);
1032 	    for (i = 1; i < length; i++) {
1033 		output_data(" %d", pointer[i]);
1034 	    }
1035 	    break;
1036 	}
1037 	output_data("\r\n");
1038 }
1039 
1040 /*
1041  * Dump a data buffer in hex and ascii to the output data stream.
1042  */
1043 void
1044 printdata(const char *tag, char *ptr, int cnt)
1045 {
1046 	int i;
1047 	char xbuf[30];
1048 
1049 	while (cnt) {
1050 		/* flush net output buffer if no room for new data) */
1051 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1052 			netflush();
1053 		}
1054 
1055 		/* add a line of output */
1056 		output_data("%s: ", tag);
1057 		for (i = 0; i < 20 && cnt; i++) {
1058 			output_data("%02x", *ptr);
1059 			if (isprint(*ptr)) {
1060 				xbuf[i] = *ptr;
1061 			} else {
1062 				xbuf[i] = '.';
1063 			}
1064 			if (i % 2) {
1065 				output_data(" ");
1066 			}
1067 			cnt--;
1068 			ptr++;
1069 		}
1070 		xbuf[i] = '\0';
1071 		output_data(" %s\r\n", xbuf );
1072 	}
1073 }
1074 #endif /* DIAGNOSTICS */
1075