xref: /minix/libexec/telnetd/utility.c (revision 9f7f0ad0)
1 /*	$NetBSD: utility.c,v 1.32 2012/01/09 16:36:48 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 1.32 2012/01/09 16:36:48 christos Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/utsname.h>
42 #include <ctype.h>
43 #define PRINTOPTIONS
44 #include "telnetd.h"
45 
46 char *nextitem(char *);
47 void putstr(char *);
48 
49 extern int not42;
50 
51 /*
52  * utility functions performing io related tasks
53  */
54 
55 /*
56  * ttloop
57  *
58  *	A small subroutine to flush the network output buffer, get some data
59  * from the network, and pass it through the telnet state machine.  We
60  * also flush the pty input buffer (by dropping its data) if it becomes
61  * too full.
62  */
63 
64 void
65 ttloop(void)
66 {
67 
68     DIAG(TD_REPORT, {output_data("td: ttloop\r\n");});
69     if (nfrontp - nbackp) {
70 	netflush();
71     }
72     ncc = read(net, netibuf, sizeof netibuf);
73     if (ncc < 0) {
74 	syslog(LOG_ERR, "ttloop:  read: %m");
75 	exit(1);
76     } else if (ncc == 0) {
77 	syslog(LOG_INFO, "ttloop:  unexpected EOF from peer");
78 	exit(1);
79     }
80     DIAG(TD_REPORT, {output_data("td: ttloop read %d chars\r\n", ncc);});
81     netip = netibuf;
82     telrcv();			/* state machine */
83     if (ncc > 0) {
84 	pfrontp = pbackp = ptyobuf;
85 	telrcv();
86     }
87 }  /* end of ttloop */
88 
89 /*
90  * Check a descriptor to see if out of band data exists on it.
91  */
92 int
93 stilloob(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(void)
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(char *current)
147 {
148     if ((*current&0xff) != IAC) {
149 	return current+1;
150     }
151     switch (*(current+1)&0xff) {
152     case DO:
153     case DONT:
154     case WILL:
155     case WONT:
156 	return current+3;
157     case SB:		/* loop forever looking for the SE */
158 	{
159 	    char *look = current+2;
160 
161 	    for (;;) {
162 		if ((*look++&0xff) == IAC) {
163 		    if ((*look++&0xff) == SE) {
164 			return look;
165 		    }
166 		}
167 	    }
168 	}
169     default:
170 	return current+2;
171     }
172 }  /* end of nextitem */
173 
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 
249     if ((n = nfrontp - nbackp) > 0) {
250 	DIAG(TD_REPORT,
251 	    { output_data("td: netflush %d chars\r\n", n);
252 	      n = nfrontp - nbackp;	/* re-compute count */
253 	    });
254 #ifdef	ENCRYPTION
255 	if (encrypt_output) {
256 		char *s = nclearto ? nclearto : nbackp;
257 		if (nfrontp - s > 0) {
258 			(*encrypt_output)((unsigned char *)s, nfrontp - s);
259 			nclearto = nfrontp;
260 		}
261 	}
262 #endif	/* ENCRYPTION */
263 	/*
264 	 * if no urgent data, or if the other side appears to be an
265 	 * old 4.2 client (and thus unable to survive TCP urgent data),
266 	 * write the entire buffer in non-OOB mode.
267 	 */
268 	if ((neturg == 0) || (not42 == 0)) {
269 	    n = write(net, nbackp, n);	/* normal write */
270 	} else {
271 	    n = neturg - nbackp;
272 	    /*
273 	     * In 4.2 (and 4.3) systems, there is some question about
274 	     * what byte in a sendOOB operation is the "OOB" data.
275 	     * To make ourselves compatible, we only send ONE byte
276 	     * out of band, the one WE THINK should be OOB (though
277 	     * we really have more the TCP philosophy of urgent data
278 	     * rather than the Unix philosophy of OOB data).
279 	     */
280 	    if (n > 1) {
281 		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */
282 	    } else {
283 		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */
284 	    }
285 	}
286     }
287     if (n < 0) {
288 	if (errno == EWOULDBLOCK || errno == EINTR)
289 		return;
290 	cleanup(0);
291     }
292     nbackp += n;
293 #ifdef	ENCRYPTION
294     if (nbackp > nclearto)
295 	nclearto = 0;
296 #endif	/* ENCRYPTION */
297     if (nbackp >= neturg) {
298 	neturg = 0;
299     }
300     if (nbackp == nfrontp) {
301 	nbackp = nfrontp = netobuf;
302 #ifdef	ENCRYPTION
303 	nclearto = 0;
304 #endif	/* ENCRYPTION */
305     }
306     return;
307 }  /* end of netflush */
308 
309 
310 /*
311  * writenet
312  *
313  * Just a handy little function to write a bit of raw data to the net.
314  * It will force a transmit of the buffer if necessary
315  *
316  * arguments
317  *    ptr - A pointer to a character string to write
318  *    len - How many bytes to write
319  */
320 void
321 writenet(unsigned char *ptr, int len)
322 {
323 	/* flush buffer if no room for new data) */
324 	if ((&netobuf[BUFSIZ] - nfrontp) < len) {
325 		/* if this fails, don't worry, buffer is a little big */
326 		netflush();
327 	}
328 
329 	memmove(nfrontp, ptr, len);
330 	nfrontp += len;
331 
332 }  /* end of writenet */
333 
334 
335 /*
336  * miscellaneous functions doing a variety of little jobs follow ...
337  */
338 void
339 fatal(int f, const char *msg)
340 {
341 	char buf[BUFSIZ];
342 
343 	(void)snprintf(buf, sizeof buf, "telnetd: %s.\r\n", msg);
344 #ifdef	ENCRYPTION
345 	if (encrypt_output) {
346 		/*
347 		 * Better turn off encryption first....
348 		 * Hope it flushes...
349 		 */
350 		encrypt_send_end();
351 		netflush();
352 	}
353 #endif	/* ENCRYPTION */
354 	(void)write(f, buf, (int)strlen(buf));
355 	sleep(1);	/*XXX*/
356 	exit(1);
357 }
358 
359 void
360 fatalperror(f, msg)
361 	int f;
362 	const char *msg;
363 {
364 	char buf[BUFSIZ];
365 
366 	(void)snprintf(buf, sizeof buf, "%s: %s", msg, strerror(errno));
367 	fatal(f, buf);
368 }
369 
370 char editedhost[MAXHOSTNAMELEN];
371 
372 void
373 edithost(const char *pat, const char *host)
374 {
375 	char *res = editedhost;
376 
377 	if (!pat)
378 		pat = "";
379 	while (*pat) {
380 		switch (*pat) {
381 
382 		case '#':
383 			if (*host)
384 				host++;
385 			break;
386 
387 		case '@':
388 			if (*host)
389 				*res++ = *host++;
390 			break;
391 
392 		default:
393 			*res++ = *pat;
394 			break;
395 		}
396 		if (res == &editedhost[sizeof editedhost - 1]) {
397 			*res = '\0';
398 			return;
399 		}
400 		pat++;
401 	}
402 	if (*host)
403 		(void) strncpy(res, host,
404 		    sizeof editedhost - (res - editedhost) -1);
405 	else
406 		*res = '\0';
407 	editedhost[sizeof editedhost - 1] = '\0';
408 }
409 
410 static char *putlocation;
411 
412 void
413 putstr(char *s)
414 {
415 
416 	while (*s)
417 		putchr(*s++);
418 }
419 
420 void
421 putchr(int cc)
422 {
423 	*putlocation++ = cc;
424 }
425 
426 /*
427  * This is split on two lines so that SCCS will not see the M
428  * between two % signs and expand it...
429  */
430 static const char fmtstr[] = { "%l:%M\
431 %p on %A, %d %B %Y" };
432 
433 char *
434 putf(const char *cp, char *where)
435 {
436 	char *slash;
437 	time_t t;
438 	char db[100];
439 	struct utsname utsinfo;
440 
441 	uname(&utsinfo);
442 
443 	putlocation = where;
444 
445 	while (*cp) {
446 		if (*cp != '%') {
447 			putchr(*cp++);
448 			continue;
449 		}
450 		switch (*++cp) {
451 
452 		case 't':
453 			if ((slash = strstr(line, "/pts/")) == NULL)
454 				slash = strrchr(line, '/');
455 			if (slash == (char *) 0)
456 				putstr(line);
457 			else
458 				putstr(&slash[1]);
459 			break;
460 
461 		case 'h':
462 			putstr(editedhost);
463 			break;
464 
465 		case 'd':
466 			(void)time(&t);
467 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
468 			putstr(db);
469 			break;
470 
471 		case '%':
472 			putchr('%');
473 			break;
474 
475 		case 's':
476 			putstr(utsinfo.sysname);
477 			break;
478 
479 		case 'm':
480 			putstr(utsinfo.machine);
481 			break;
482 
483 		case 'r':
484 			putstr(utsinfo.release);
485 			break;
486 
487 		case 'v':
488 			putstr(utsinfo.version);
489                         break;
490 		}
491 		cp++;
492 	}
493 
494 	return (putlocation);
495 }
496 
497 #ifdef DIAGNOSTICS
498 /*
499  * Print telnet options and commands in plain text, if possible.
500  */
501 void
502 printoption(const char *fmt, int option)
503 {
504 	if (TELOPT_OK(option))
505 		output_data("%s %s\r\n", fmt, TELOPT(option));
506 	else if (TELCMD_OK(option))
507 		output_data("%s %s\r\n", fmt, TELCMD(option));
508 	else
509 		output_data("%s %d\r\n", fmt, option);
510 	return;
511 }
512 
513 void
514 printsub(
515     int	   direction,	/* '<' or '>' */
516     unsigned char *pointer,	/* where suboption data sits */
517     int		   length)	/* length of suboption data */
518 {
519     int i = 0;
520 #if	defined(AUTHENTICATION) || defined(ENCRYPTION)
521     u_char buf[512];
522 #endif
523 
524 	if (!(diagnostic & TD_OPTIONS))
525 		return;
526 
527 	if (direction) {
528 	    output_data("td: %s suboption ",
529 	        direction == '<' ? "recv" : "send");
530 	    if (length >= 3) {
531 		int j;
532 
533 		i = pointer[length - 2];
534 		j = pointer[length - 1];
535 
536 		if (i != IAC || j != SE) {
537 		    output_data("(terminated by ");
538 		    if (TELOPT_OK(i))
539 			output_data("%s ", TELOPT(i));
540 		    else if (TELCMD_OK(i))
541 			output_data("%s ", TELCMD(i));
542 		    else
543 			output_data("%d ", i);
544 		    if (TELOPT_OK(j))
545 			output_data("%s", TELOPT(j));
546 		    else if (TELCMD_OK(j))
547 			output_data("%s", TELCMD(j));
548 		    else
549 			output_data("%d", j);
550 		    output_data(", not IAC SE!) ");
551 		}
552 	    }
553 	    length -= 2;
554 	}
555 	if (length < 1) {
556 	    output_data("(Empty suboption??\?)");
557 	    return;
558 	}
559 	switch (pointer[0]) {
560 	case TELOPT_TTYPE:
561 	    output_data("TERMINAL-TYPE ");
562 	    switch (pointer[1]) {
563 	    case TELQUAL_IS:
564 		output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
565 		break;
566 	    case TELQUAL_SEND:
567 		output_data("SEND");
568 		break;
569 	    default:
570 		output_data("- unknown qualifier %d (0x%x).",
571 		    pointer[1], pointer[1]);
572 	    }
573 	    break;
574 	case TELOPT_TSPEED:
575 	    output_data("TERMINAL-SPEED");
576 	    if (length < 2) {
577 		output_data(" (empty suboption??\?)");
578 		break;
579 	    }
580 	    switch (pointer[1]) {
581 	    case TELQUAL_IS:
582 		output_data(" IS %.*s", length-2, (char *)pointer+2);
583 		break;
584 	    default:
585 		if (pointer[1] == 1)
586 		    output_data(" SEND");
587 		else
588 		    output_data(" %d (unknown)", pointer[1]);
589 		for (i = 2; i < length; i++) {
590 		    output_data(" ?%d?", pointer[i]);
591 		}
592 		break;
593 	    }
594 	    break;
595 
596 	case TELOPT_LFLOW:
597 	    output_data("TOGGLE-FLOW-CONTROL");
598 	    if (length < 2) {
599 		output_data(" (empty suboption??\?)");
600 		break;
601 	    }
602 	    switch (pointer[1]) {
603 	    case LFLOW_OFF:
604 		output_data(" OFF"); break;
605 	    case LFLOW_ON:
606 		output_data(" ON"); break;
607 	    case LFLOW_RESTART_ANY:
608 		output_data(" RESTART-ANY"); break;
609 	    case LFLOW_RESTART_XON:
610 		output_data(" RESTART-XON"); break;
611 	    default:
612 		output_data(" %d (unknown)", pointer[1]);
613 	    }
614 	    for (i = 2; i < length; i++)
615 		output_data(" ?%d?", pointer[i]);
616 	    break;
617 
618 	case TELOPT_NAWS:
619 	    output_data("NAWS");
620 	    if (length < 2) {
621 		output_data(" (empty suboption??\?)");
622 		break;
623 	    }
624 	    if (length == 2) {
625 		output_data(" ?%d?", pointer[1]);
626 		break;
627 	    }
628 	    output_data(" %d %d (%d)",
629 		pointer[1], pointer[2],
630 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
631 	    if (length == 4) {
632 		output_data(" ?%d?", pointer[3]);
633 		break;
634 	    }
635 	    output_data(" %d %d (%d)", pointer[3], pointer[4],
636 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
637 	    for (i = 5; i < length; i++) {
638 		output_data(" ?%d?", pointer[i]);
639 	    }
640 	    break;
641 
642 	case TELOPT_LINEMODE:
643 	    output_data("LINEMODE ");
644 	    if (length < 2) {
645 		output_data(" (empty suboption??\?)");
646 		break;
647 	    }
648 	    switch (pointer[1]) {
649 	    case WILL:
650 		output_data("WILL ");
651 		goto common;
652 	    case WONT:
653 		output_data("WONT ");
654 		goto common;
655 	    case DO:
656 		output_data("DO ");
657 		goto common;
658 	    case DONT:
659 		output_data("DONT ");
660 	    common:
661 		if (length < 3) {
662 		    output_data("(no option??\?)");
663 		    break;
664 		}
665 		switch (pointer[2]) {
666 		case LM_FORWARDMASK:
667 		    output_data("Forward Mask");
668 		    for (i = 3; i < length; i++)
669 			output_data(" %x", pointer[i]);
670 		    break;
671 		default:
672 		    output_data("%d (unknown)", pointer[2]);
673 		    for (i = 3; i < length; i++)
674 			output_data(" %d", pointer[i]);
675 		    break;
676 		}
677 		break;
678 
679 	    case LM_SLC:
680 		output_data("SLC");
681 		for (i = 2; i < length - 2; i += 3) {
682 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
683 			output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
684 		    else
685 			output_data(" %d", pointer[i+SLC_FUNC]);
686 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
687 		    case SLC_NOSUPPORT:
688 			output_data(" NOSUPPORT"); break;
689 		    case SLC_CANTCHANGE:
690 			output_data(" CANTCHANGE"); break;
691 		    case SLC_VARIABLE:
692 			output_data(" VARIABLE"); break;
693 		    case SLC_DEFAULT:
694 			output_data(" DEFAULT"); break;
695 		    }
696 		    output_data("%s%s%s",
697 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
698 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
699 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
700 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
701 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
702 			output_data("(0x%x)", pointer[i+SLC_FLAGS]);
703 		    }
704 		    output_data(" %d;", pointer[i+SLC_VALUE]);
705 		    if ((pointer[i+SLC_VALUE] == IAC) &&
706 			(pointer[i+SLC_VALUE+1] == IAC))
707 				i++;
708 		}
709 		for (; i < length; i++)
710 		    output_data(" ?%d?", pointer[i]);
711 		break;
712 
713 	    case LM_MODE:
714 		output_data("MODE ");
715 		if (length < 3) {
716 		    output_data("(no mode??\?)");
717 		    break;
718 		}
719 		{
720 		    char tbuf[32];
721 
722 		    (void)snprintf(tbuf, sizeof tbuf, "%s%s%s%s%s",
723 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
724 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
725 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
726 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
727 			pointer[2]&MODE_ACK ? "|ACK" : "");
728 		    output_data("%s", tbuf[1] ? &tbuf[1] : "0");
729 		}
730 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK))
731 		    output_data(" (0x%x)", pointer[2]);
732 		for (i = 3; i < length; i++)
733 		    output_data(" ?0x%x?", pointer[i]);
734 		break;
735 	    default:
736 		output_data("%d (unknown)", pointer[1]);
737 		for (i = 2; i < length; i++)
738 		    output_data(" %d", pointer[i]);
739 	    }
740 	    break;
741 
742 	case TELOPT_STATUS: {
743 	    const char *cp;
744 	    int j, k;
745 
746 	    output_data("STATUS");
747 
748 	    switch (pointer[1]) {
749 	    default:
750 		if (pointer[1] == TELQUAL_SEND)
751 		    output_data(" SEND");
752 		else
753 		    output_data(" %d (unknown)", pointer[1]);
754 		for (i = 2; i < length; i++)
755 		    output_data(" ?%d?", pointer[i]);
756 		break;
757 	    case TELQUAL_IS:
758 		output_data(" IS\r\n");
759 
760 		for (i = 2; i < length; i++) {
761 		    switch(pointer[i]) {
762 		    case DO:	cp = "DO"; goto common2;
763 		    case DONT:	cp = "DONT"; goto common2;
764 		    case WILL:	cp = "WILL"; goto common2;
765 		    case WONT:	cp = "WONT"; goto common2;
766 		    common2:
767 			i++;
768 			if (TELOPT_OK(pointer[i]))
769 			    output_data(" %s %s", cp, TELOPT(pointer[i]));
770 			else
771 			    output_data(" %s %d", cp, pointer[i]);
772 
773 			output_data("\r\n");
774 			break;
775 
776 		    case SB:
777 			output_data(" SB ");
778 			i++;
779 			j = k = i;
780 			while (j < length) {
781 			    if (pointer[j] == SE) {
782 				if (j+1 == length)
783 				    break;
784 				if (pointer[j+1] == SE)
785 				    j++;
786 				else
787 				    break;
788 			    }
789 			    pointer[k++] = pointer[j++];
790 			}
791 			printsub(0, &pointer[i], k - i);
792 			if (i < length) {
793 			    output_data(" SE");
794 			    i = j;
795 			} else
796 			    i = j - 1;
797 
798 			output_data("\r\n");
799 
800 			break;
801 
802 		    default:
803 			output_data(" %d", pointer[i]);
804 			break;
805 		    }
806 		}
807 		break;
808 	    }
809 	    break;
810 	  }
811 
812 	case TELOPT_XDISPLOC:
813 	    output_data("X-DISPLAY-LOCATION ");
814 	    switch (pointer[1]) {
815 	    case TELQUAL_IS:
816 		output_data("IS \"%.*s\"", length - 2, (char *)pointer + 2);
817 		break;
818 	    case TELQUAL_SEND:
819 		output_data("SEND");
820 		break;
821 	    default:
822 		output_data("- unknown qualifier %d (0x%x).",
823 		    pointer[1], pointer[1]);
824 	    }
825 	    break;
826 
827 	case TELOPT_NEW_ENVIRON:
828 	    output_data("NEW-ENVIRON ");
829 	    goto env_common1;
830 	case TELOPT_OLD_ENVIRON:
831 	    output_data("OLD-ENVIRON");
832 	env_common1:
833 	    switch (pointer[1]) {
834 	    case TELQUAL_IS:
835 		output_data("IS ");
836 		goto env_common;
837 	    case TELQUAL_SEND:
838 		output_data("SEND ");
839 		goto env_common;
840 	    case TELQUAL_INFO:
841 		output_data("INFO ");
842 	    env_common:
843 		{
844 		    static const char NQ[] = "\" ";
845 		    const char *noquote = NQ;
846 		    for (i = 2; i < length; i++ ) {
847 			switch (pointer[i]) {
848 			case NEW_ENV_VAR:
849 			    output_data("%sVAR ", noquote);
850 			    noquote = NQ;
851 			    break;
852 
853 			case NEW_ENV_VALUE:
854 			    output_data("%sVALUE ", noquote);
855 			    noquote = NQ;
856 			    break;
857 
858 			case ENV_ESC:
859 			    output_data("%sESC ", noquote);
860 			    noquote = NQ;
861 			    break;
862 
863 			case ENV_USERVAR:
864 			    output_data("%sUSERVAR ", noquote);
865 			    noquote = NQ;
866 			    break;
867 
868 			default:
869 			    if (isprint(pointer[i]) && pointer[i] != '"') {
870 				if (*noquote) {
871 				    output_data("\"");
872 				    noquote = "";
873 				}
874 				output_data("%c", pointer[i]);
875 			    } else {
876 				output_data("%s%03o ", noquote, pointer[i]);
877 				noquote = NQ;
878 			    }
879 			    break;
880 			}
881 		    }
882 		    if (!noquote)
883 			output_data("\"");
884 		    break;
885 		}
886 	    }
887 	    break;
888 
889 #ifdef AUTHENTICATION
890 	case TELOPT_AUTHENTICATION:
891 	    output_data("AUTHENTICATION");
892 
893 	    if (length < 2) {
894 		output_data(" (empty suboption??\?)");
895 		break;
896 	    }
897 	    switch (pointer[1]) {
898 	    case TELQUAL_REPLY:
899 	    case TELQUAL_IS:
900 		output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
901 		    "IS" : "REPLY");
902 		if (AUTHTYPE_NAME_OK(pointer[2]))
903 		    output_data("%s ", AUTHTYPE_NAME(pointer[2]));
904 		else
905 		    output_data("%d ", pointer[2]);
906 		if (length < 3) {
907 		    output_data("(partial suboption??\?)");
908 		    break;
909 		}
910 		output_data("%s|%s",
911 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
912 			"CLIENT" : "SERVER",
913 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
914 			"MUTUAL" : "ONE-WAY");
915 
916 		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
917 		output_data("%s", buf);
918 		break;
919 
920 	    case TELQUAL_SEND:
921 		i = 2;
922 		output_data(" SEND ");
923 		while (i < length) {
924 		    if (AUTHTYPE_NAME_OK(pointer[i]))
925 			output_data("%s ", AUTHTYPE_NAME(pointer[i]));
926 		    else
927 			output_data("%d ", pointer[i]);
928 		    if (++i >= length) {
929 			output_data("(partial suboption??\?)");
930 			break;
931 		    }
932 		    output_data("%s|%s ",
933 			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
934 							"CLIENT" : "SERVER",
935 			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
936 							"MUTUAL" : "ONE-WAY");
937 		    ++i;
938 		}
939 		break;
940 
941 	    case TELQUAL_NAME:
942 		i = 2;
943 		output_data(" NAME \"");
944 		while (i < length) {
945 		    if (isprint(pointer[i]))
946 			output_data("%c", pointer[i++]);
947 		    else
948 			output_data("\"%03o\"",pointer[i++]);
949 		}
950 		output_data("\"");
951 		break;
952 
953 	    default:
954 		for (i = 2; i < length; i++)
955 		    output_data(" ?%d?", pointer[i]);
956 		break;
957 	    }
958 	    break;
959 #endif
960 
961 #ifdef	ENCRYPTION
962 	case TELOPT_ENCRYPT:
963 	    output_data("ENCRYPT");
964 	    if (length < 2) {
965 		output_data(" (empty suboption??\?)");
966 		break;
967 	    }
968 	    switch (pointer[1]) {
969 	    case ENCRYPT_START:
970 		output_data(" START");
971 		break;
972 
973 	    case ENCRYPT_END:
974 		output_data(" END");
975 		break;
976 
977 	    case ENCRYPT_REQSTART:
978 		output_data(" REQUEST-START");
979 		break;
980 
981 	    case ENCRYPT_REQEND:
982 		output_data(" REQUEST-END");
983 		break;
984 
985 	    case ENCRYPT_IS:
986 	    case ENCRYPT_REPLY:
987 		output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
988 		    "IS" : "REPLY");
989 		if (length < 3) {
990 			output_data(" (partial suboption??\?)");
991 			break;
992 		}
993 		if (ENCTYPE_NAME_OK(pointer[2]))
994 			output_data("%s ", ENCTYPE_NAME(pointer[2]));
995 		else
996 			output_data(" %d (unknown)", pointer[2]);
997 
998 		encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
999 		output_data("%s", buf);
1000 		break;
1001 
1002 	    case ENCRYPT_SUPPORT:
1003 		i = 2;
1004 		output_data(" SUPPORT ");
1005 		while (i < length) {
1006 			if (ENCTYPE_NAME_OK(pointer[i]))
1007 				output_data("%s ", ENCTYPE_NAME(pointer[i]));
1008 			else
1009 				output_data("%d ", pointer[i]);
1010 			i++;
1011 		}
1012 		break;
1013 
1014 	    case ENCRYPT_ENC_KEYID:
1015 		output_data(" ENC_KEYID");
1016 		goto encommon;
1017 
1018 	    case ENCRYPT_DEC_KEYID:
1019 		output_data(" DEC_KEYID");
1020 		goto encommon;
1021 
1022 	    default:
1023 		output_data(" %d (unknown)", pointer[1]);
1024 	    encommon:
1025 		for (i = 2; i < length; i++)
1026 			output_data(" %d", pointer[i]);
1027 		break;
1028 	    }
1029 	    break;
1030 #endif	/* ENCRYPTION */
1031 
1032 	default:
1033 	    if (TELOPT_OK(pointer[0]))
1034 		output_data("%s (unknown)", TELOPT(pointer[0]));
1035 	    else
1036 		output_data("%d (unknown)", pointer[i]);
1037 	    for (i = 1; i < length; i++)
1038 		output_data(" %d", pointer[i]);
1039 	    break;
1040 	}
1041 	output_data("\r\n");
1042 }
1043 
1044 /*
1045  * Dump a data buffer in hex and ascii to the output data stream.
1046  */
1047 void
1048 printdata(const char *tag, char *ptr, int cnt)
1049 {
1050 	int i;
1051 	char xbuf[30];
1052 
1053 	while (cnt) {
1054 		/* flush net output buffer if no room for new data) */
1055 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1056 			netflush();
1057 		}
1058 
1059 		/* add a line of output */
1060 		output_data("%s: ", tag);
1061 		for (i = 0; i < 20 && cnt; i++) {
1062 			output_data("%02x", *ptr);
1063 			if (isprint((unsigned char)*ptr)) {
1064 				xbuf[i] = *ptr;
1065 			} else {
1066 				xbuf[i] = '.';
1067 			}
1068 			if (i % 2)
1069 				output_data(" ");
1070 			cnt--;
1071 			ptr++;
1072 		}
1073 		xbuf[i] = '\0';
1074 		output_data(" %s\r\n", xbuf);
1075 	}
1076 }
1077 #endif /* DIAGNOSTICS */
1078