xref: /netbsd-src/libexec/telnetd/utility.c (revision 5f7096188587a2c7c95fa3c69b78e1ec9c7923d0)
1 /*
2  * Copyright (c) 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 /*static char sccsid[] = "from: @(#)utility.c	5.8 (Berkeley) 3/22/91";*/
36 static char rcsid[] = "$Id: utility.c,v 1.4 1993/08/30 18:53:06 mycroft Exp $";
37 #endif /* not lint */
38 
39 #define PRINTOPTIONS
40 #include <sys/utsname.h>
41 #include "telnetd.h"
42 
43 /*
44  * utility functions performing io related tasks
45  */
46 
47 /*
48  * ttloop
49  *
50  *	A small subroutine to flush the network output buffer, get some data
51  * from the network, and pass it through the telnet state machine.  We
52  * also flush the pty input buffer (by dropping its data) if it becomes
53  * too full.
54  */
55 
56     void
57 ttloop()
58 {
59     void netflush();
60 
61     DIAG(TD_REPORT, {sprintf(nfrontp, "td: ttloop\r\n");
62 		     nfrontp += strlen(nfrontp);});
63     if (nfrontp-nbackp) {
64 	netflush();
65     }
66     ncc = read(net, netibuf, sizeof netibuf);
67     if (ncc < 0) {
68 	syslog(LOG_INFO, "ttloop:  read: %m\n");
69 	exit(1);
70     } else if (ncc == 0) {
71 	syslog(LOG_INFO, "ttloop:  peer died: %m\n");
72 	exit(1);
73     }
74     DIAG(TD_REPORT, {sprintf(nfrontp, "td: ttloop read %d chars\r\n", ncc);
75 		     nfrontp += strlen(nfrontp);});
76     netip = netibuf;
77     telrcv();			/* state machine */
78     if (ncc > 0) {
79 	pfrontp = pbackp = ptyobuf;
80 	telrcv();
81     }
82 }  /* end of ttloop */
83 
84 /*
85  * Check a descriptor to see if out of band data exists on it.
86  */
87     int
88 stilloob(s)
89     int	s;		/* socket number */
90 {
91     static struct timeval timeout = { 0 };
92     fd_set	excepts;
93     int value;
94 
95     do {
96 	FD_ZERO(&excepts);
97 	FD_SET(s, &excepts);
98 	value = select(s+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
99     } while ((value == -1) && (errno == EINTR));
100 
101     if (value < 0) {
102 	fatalperror(pty, "select");
103     }
104     if (FD_ISSET(s, &excepts)) {
105 	return 1;
106     } else {
107 	return 0;
108     }
109 }
110 
111 	void
112 ptyflush()
113 {
114 	int n;
115 
116 	if ((n = pfrontp - pbackp) > 0) {
117 		DIAG((TD_REPORT | TD_PTYDATA),
118 			{ sprintf(nfrontp, "td: ptyflush %d chars\r\n", n);
119 			  nfrontp += strlen(nfrontp); });
120 		DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
121 		n = write(pty, pbackp, n);
122 	}
123 	if (n < 0) {
124 		if (errno == EWOULDBLOCK || errno == EINTR)
125 			return;
126 		cleanup(0);
127 	}
128 	pbackp += n;
129 	if (pbackp == pfrontp)
130 		pbackp = pfrontp = ptyobuf;
131 }
132 
133 /*
134  * nextitem()
135  *
136  *	Return the address of the next "item" in the TELNET data
137  * stream.  This will be the address of the next character if
138  * the current address is a user data character, or it will
139  * be the address of the character following the TELNET command
140  * if the current address is a TELNET IAC ("I Am a Command")
141  * character.
142  */
143     char *
144 nextitem(current)
145     char	*current;
146 {
147     if ((*current&0xff) != IAC) {
148 	return current+1;
149     }
150     switch (*(current+1)&0xff) {
151     case DO:
152     case DONT:
153     case WILL:
154     case WONT:
155 	return current+3;
156     case SB:		/* loop forever looking for the SE */
157 	{
158 	    register char *look = current+2;
159 
160 	    for (;;) {
161 		if ((*look++&0xff) == IAC) {
162 		    if ((*look++&0xff) == SE) {
163 			return look;
164 		    }
165 		}
166 	    }
167 	}
168     default:
169 	return current+2;
170     }
171 }  /* end of nextitem */
172 
173 
174 /*
175  * netclear()
176  *
177  *	We are about to do a TELNET SYNCH operation.  Clear
178  * the path to the network.
179  *
180  *	Things are a bit tricky since we may have sent the first
181  * byte or so of a previous TELNET command into the network.
182  * So, we have to scan the network buffer from the beginning
183  * until we are up to where we want to be.
184  *
185  *	A side effect of what we do, just to keep things
186  * simple, is to clear the urgent data pointer.  The principal
187  * caller should be setting the urgent data pointer AFTER calling
188  * us in any case.
189  */
190     void
191 netclear()
192 {
193     register char *thisitem, *next;
194     char *good;
195 #define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \
196 				((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
197 
198 #if	defined(ENCRYPT)
199     thisitem = nclearto > netobuf ? nclearto : netobuf;
200 #else
201     thisitem = netobuf;
202 #endif
203 
204     while ((next = nextitem(thisitem)) <= nbackp) {
205 	thisitem = next;
206     }
207 
208     /* Now, thisitem is first before/at boundary. */
209 
210 #if	defined(ENCRYPT)
211     good = nclearto > netobuf ? nclearto : netobuf;
212 #else
213     good = netobuf;	/* where the good bytes go */
214 #endif
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 	    bcopy(thisitem, good, 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()
245 {
246     int n;
247     extern int not42;
248 
249     if ((n = nfrontp - nbackp) > 0) {
250 	DIAG(TD_REPORT,
251 	    { sprintf(nfrontp, "td: netflush %d chars\r\n", n);
252 	      n += strlen(nfrontp);  /* get count first */
253 	      nfrontp += strlen(nfrontp);  /* then move pointer */
254 	    });
255 #if	defined(ENCRYPT)
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
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 #if	defined(ENCRYPT)
295     if (nbackp > nclearto)
296 	nclearto = 0;
297 #endif
298     if (nbackp >= neturg) {
299 	neturg = 0;
300     }
301     if (nbackp == nfrontp) {
302 	nbackp = nfrontp = netobuf;
303 #if	defined(ENCRYPT)
304 	nclearto = 0;
305 #endif
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 	bcopy(ptr, nfrontp, len);
333 	nfrontp += len;
334 
335 }  /* end of writenet */
336 
337 
338 /*
339  * miscellaneous functions doing a variety of little jobs follow ...
340  */
341 
342 
343 	void
344 fatal(f, msg)
345 	int f;
346 	char *msg;
347 {
348 	char buf[BUFSIZ];
349 
350 	(void) sprintf(buf, "telnetd: %s.\r\n", msg);
351 #if	defined(ENCRYPT)
352 	if (encrypt_output) {
353 		/*
354 		 * Better turn off encryption first....
355 		 * Hope it flushes...
356 		 */
357 		encrypt_send_end();
358 		netflush();
359 	}
360 #endif
361 	(void) write(f, buf, (int)strlen(buf));
362 	sleep(1);	/*XXX*/
363 	exit(1);
364 }
365 
366 	void
367 fatalperror(f, msg)
368 	int f;
369 	char *msg;
370 {
371 	char buf[BUFSIZ], *strerror();
372 
373 	(void) sprintf(buf, "%s: %s\r\n", msg, strerror(errno));
374 	fatal(f, buf);
375 }
376 
377 char editedhost[32];
378 struct utsname kerninfo;
379 
380 	void
381 edithost(pat, host)
382 	register char *pat;
383 	register char *host;
384 {
385 	register char *res = editedhost;
386 	char *strncpy();
387 
388 	uname(&kerninfo);
389 
390 	if (!pat)
391 		pat = "";
392 	while (*pat) {
393 		switch (*pat) {
394 
395 		case '#':
396 			if (*host)
397 				host++;
398 			break;
399 
400 		case '@':
401 			if (*host)
402 				*res++ = *host++;
403 			break;
404 
405 		default:
406 			*res++ = *pat;
407 			break;
408 		}
409 		if (res == &editedhost[sizeof editedhost - 1]) {
410 			*res = '\0';
411 			return;
412 		}
413 		pat++;
414 	}
415 	if (*host)
416 		(void) strncpy(res, host,
417 				sizeof editedhost - (res - editedhost) -1);
418 	else
419 		*res = '\0';
420 	editedhost[sizeof editedhost - 1] = '\0';
421 }
422 
423 static char *putlocation;
424 
425 	void
426 putstr(s)
427 	register char *s;
428 {
429 
430 	while (*s)
431 		putchr(*s++);
432 }
433 
434 	void
435 putchr(cc)
436 	int cc;
437 {
438 	*putlocation++ = cc;
439 }
440 
441 /*
442  * This is split on two lines so that SCCS will not see the M
443  * between two % signs and expand it...
444  */
445 static char fmtstr[] = { "%l:%M\
446 %P on %A, %d %B %Y" };
447 
448 	void
449 putf(cp, where)
450 	register char *cp;
451 	char *where;
452 {
453 	char *slash;
454 	time_t t;
455 	char db[100];
456 	extern char *rindex();
457 
458 	putlocation = where;
459 
460 	while (*cp) {
461 		if (*cp != '%') {
462 			putchr(*cp++);
463 			continue;
464 		}
465 		switch (*++cp) {
466 
467 		case 't':
468 			slash = rindex(line, '/');
469 			if (slash == (char *) 0)
470 				putstr(line);
471 			else
472 				putstr(&slash[1]);
473 			break;
474 
475 		case 'h':
476 			putstr(editedhost);
477 			break;
478 
479 		case 'd':
480 			(void)time(&t);
481 			(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
482 			putstr(db);
483 			break;
484 
485 		case '%':
486 			putchr('%');
487 			break;
488 
489 		case 's':
490 			putstr(kerninfo.sysname);
491 			break;
492 
493 		case 'm':
494 			putstr(kerninfo.machine);
495 			break;
496 
497 		case 'r':
498 			putstr(kerninfo.release);
499 			break;
500 
501 		case 'v':
502 			puts(kerninfo.version);
503 			break;
504 		}
505 		cp++;
506 	}
507 }
508 
509 #ifdef DIAGNOSTICS
510 /*
511  * Print telnet options and commands in plain text, if possible.
512  */
513 	void
514 printoption(fmt, option)
515 	register char *fmt;
516 	register int option;
517 {
518 	if (TELOPT_OK(option))
519 		sprintf(nfrontp, "%s %s\r\n", fmt, TELOPT(option));
520 	else if (TELCMD_OK(option))
521 		sprintf(nfrontp, "%s %s\r\n", fmt, TELCMD(option));
522 	else
523 		sprintf(nfrontp, "%s %d\r\n", fmt, option);
524 	nfrontp += strlen(nfrontp);
525 	return;
526 }
527 
528     void
529 printsub(direction, pointer, length)
530     char		direction;	/* '<' or '>' */
531     unsigned char	*pointer;	/* where suboption data sits */
532     int			length;		/* length of suboption data */
533 {
534     register int i;
535     char buf[512];
536 
537         if (!(diagnostic & TD_OPTIONS))
538 		return;
539 
540 	if (direction) {
541 	    sprintf(nfrontp, "td: %s suboption ",
542 					direction == '<' ? "recv" : "send");
543 	    nfrontp += strlen(nfrontp);
544 	    if (length >= 3) {
545 		register int j;
546 
547 		i = pointer[length-2];
548 		j = pointer[length-1];
549 
550 		if (i != IAC || j != SE) {
551 		    sprintf(nfrontp, "(terminated by ");
552 		    nfrontp += strlen(nfrontp);
553 		    if (TELOPT_OK(i))
554 			sprintf(nfrontp, "%s ", TELOPT(i));
555 		    else if (TELCMD_OK(i))
556 			sprintf(nfrontp, "%s ", TELCMD(i));
557 		    else
558 			sprintf(nfrontp, "%d ", i);
559 		    nfrontp += strlen(nfrontp);
560 		    if (TELOPT_OK(j))
561 			sprintf(nfrontp, "%s", TELOPT(j));
562 		    else if (TELCMD_OK(j))
563 			sprintf(nfrontp, "%s", TELCMD(j));
564 		    else
565 			sprintf(nfrontp, "%d", j);
566 		    nfrontp += strlen(nfrontp);
567 		    sprintf(nfrontp, ", not IAC SE!) ");
568 		    nfrontp += strlen(nfrontp);
569 		}
570 	    }
571 	    length -= 2;
572 	}
573 	if (length < 1) {
574 	    sprintf(nfrontp, "(Empty suboption???)");
575 	    nfrontp += strlen(nfrontp);
576 	    return;
577 	}
578 	switch (pointer[0]) {
579 	case TELOPT_TTYPE:
580 	    sprintf(nfrontp, "TERMINAL-TYPE ");
581 	    nfrontp += strlen(nfrontp);
582 	    switch (pointer[1]) {
583 	    case TELQUAL_IS:
584 		sprintf(nfrontp, "IS \"%.*s\"", length-2, (char *)pointer+2);
585 		break;
586 	    case TELQUAL_SEND:
587 		sprintf(nfrontp, "SEND");
588 		break;
589 	    default:
590 		sprintf(nfrontp,
591 				"- unknown qualifier %d (0x%x).",
592 				pointer[1], pointer[1]);
593 	    }
594 	    nfrontp += strlen(nfrontp);
595 	    break;
596 	case TELOPT_TSPEED:
597 	    sprintf(nfrontp, "TERMINAL-SPEED");
598 	    nfrontp += strlen(nfrontp);
599 	    if (length < 2) {
600 		sprintf(nfrontp, " (empty suboption???)");
601 		nfrontp += strlen(nfrontp);
602 		break;
603 	    }
604 	    switch (pointer[1]) {
605 	    case TELQUAL_IS:
606 		sprintf(nfrontp, " IS %.*s", length-2, (char *)pointer+2);
607 		nfrontp += strlen(nfrontp);
608 		break;
609 	    default:
610 		if (pointer[1] == 1)
611 		    sprintf(nfrontp, " SEND");
612 		else
613 		    sprintf(nfrontp, " %d (unknown)", pointer[1]);
614 		nfrontp += strlen(nfrontp);
615 		for (i = 2; i < length; i++) {
616 		    sprintf(nfrontp, " ?%d?", pointer[i]);
617 		    nfrontp += strlen(nfrontp);
618 		}
619 		break;
620 	    }
621 	    break;
622 
623 	case TELOPT_LFLOW:
624 	    sprintf(nfrontp, "TOGGLE-FLOW-CONTROL");
625 	    nfrontp += strlen(nfrontp);
626 	    if (length < 2) {
627 		sprintf(nfrontp, " (empty suboption???)");
628 		nfrontp += strlen(nfrontp);
629 		break;
630 	    }
631 	    switch (pointer[1]) {
632 	    case 0:
633 		sprintf(nfrontp, " OFF"); break;
634 	    case 1:
635 		sprintf(nfrontp, " ON"); break;
636 	    default:
637 		sprintf(nfrontp, " %d (unknown)", pointer[1]);
638 	    }
639 	    nfrontp += strlen(nfrontp);
640 	    for (i = 2; i < length; i++) {
641 		sprintf(nfrontp, " ?%d?", pointer[i]);
642 		nfrontp += strlen(nfrontp);
643 	    }
644 	    break;
645 
646 	case TELOPT_NAWS:
647 	    sprintf(nfrontp, "NAWS");
648 	    nfrontp += strlen(nfrontp);
649 	    if (length < 2) {
650 		sprintf(nfrontp, " (empty suboption???)");
651 		nfrontp += strlen(nfrontp);
652 		break;
653 	    }
654 	    if (length == 2) {
655 		sprintf(nfrontp, " ?%d?", pointer[1]);
656 		nfrontp += strlen(nfrontp);
657 		break;
658 	    }
659 	    sprintf(nfrontp, " %d %d (%d)",
660 		pointer[1], pointer[2],
661 		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
662 	    nfrontp += strlen(nfrontp);
663 	    if (length == 4) {
664 		sprintf(nfrontp, " ?%d?", pointer[3]);
665 		nfrontp += strlen(nfrontp);
666 		break;
667 	    }
668 	    sprintf(nfrontp, " %d %d (%d)",
669 		pointer[3], pointer[4],
670 		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
671 	    nfrontp += strlen(nfrontp);
672 	    for (i = 5; i < length; i++) {
673 		sprintf(nfrontp, " ?%d?", pointer[i]);
674 		nfrontp += strlen(nfrontp);
675 	    }
676 	    break;
677 
678 	case TELOPT_LINEMODE:
679 	    sprintf(nfrontp, "LINEMODE ");
680 	    nfrontp += strlen(nfrontp);
681 	    if (length < 2) {
682 		sprintf(nfrontp, " (empty suboption???)");
683 		nfrontp += strlen(nfrontp);
684 		break;
685 	    }
686 	    switch (pointer[1]) {
687 	    case WILL:
688 		sprintf(nfrontp, "WILL ");
689 		goto common;
690 	    case WONT:
691 		sprintf(nfrontp, "WONT ");
692 		goto common;
693 	    case DO:
694 		sprintf(nfrontp, "DO ");
695 		goto common;
696 	    case DONT:
697 		sprintf(nfrontp, "DONT ");
698 	    common:
699 		nfrontp += strlen(nfrontp);
700 		if (length < 3) {
701 		    sprintf(nfrontp, "(no option???)");
702 		    nfrontp += strlen(nfrontp);
703 		    break;
704 		}
705 		switch (pointer[2]) {
706 		case LM_FORWARDMASK:
707 		    sprintf(nfrontp, "Forward Mask");
708 		    nfrontp += strlen(nfrontp);
709 		    for (i = 3; i < length; i++) {
710 			sprintf(nfrontp, " %x", pointer[i]);
711 			nfrontp += strlen(nfrontp);
712 		    }
713 		    break;
714 		default:
715 		    sprintf(nfrontp, "%d (unknown)", pointer[2]);
716 		    nfrontp += strlen(nfrontp);
717 		    for (i = 3; i < length; i++) {
718 			sprintf(nfrontp, " %d", pointer[i]);
719 			nfrontp += strlen(nfrontp);
720 		    }
721 		    break;
722 		}
723 		break;
724 
725 	    case LM_SLC:
726 		sprintf(nfrontp, "SLC");
727 		nfrontp += strlen(nfrontp);
728 		for (i = 2; i < length - 2; i += 3) {
729 		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
730 			sprintf(nfrontp, " %s", SLC_NAME(pointer[i+SLC_FUNC]));
731 		    else
732 			sprintf(nfrontp, " %d", pointer[i+SLC_FUNC]);
733 		    nfrontp += strlen(nfrontp);
734 		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
735 		    case SLC_NOSUPPORT:
736 			sprintf(nfrontp, " NOSUPPORT"); break;
737 		    case SLC_CANTCHANGE:
738 			sprintf(nfrontp, " CANTCHANGE"); break;
739 		    case SLC_VARIABLE:
740 			sprintf(nfrontp, " VARIABLE"); break;
741 		    case SLC_DEFAULT:
742 			sprintf(nfrontp, " DEFAULT"); break;
743 		    }
744 		    nfrontp += strlen(nfrontp);
745 		    sprintf(nfrontp, "%s%s%s",
746 			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
747 			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
748 			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
749 		    nfrontp += strlen(nfrontp);
750 		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
751 						SLC_FLUSHOUT| SLC_LEVELBITS)) {
752 			sprintf(nfrontp, "(0x%x)", pointer[i+SLC_FLAGS]);
753 			nfrontp += strlen(nfrontp);
754 		    }
755 		    sprintf(nfrontp, " %d;", pointer[i+SLC_VALUE]);
756 		    nfrontp += strlen(nfrontp);
757 		    if ((pointer[i+SLC_VALUE] == IAC) &&
758 			(pointer[i+SLC_VALUE+1] == IAC))
759 				i++;
760 		}
761 		for (; i < length; i++) {
762 		    sprintf(nfrontp, " ?%d?", pointer[i]);
763 		    nfrontp += strlen(nfrontp);
764 		}
765 		break;
766 
767 	    case LM_MODE:
768 		sprintf(nfrontp, "MODE ");
769 		nfrontp += strlen(nfrontp);
770 		if (length < 3) {
771 		    sprintf(nfrontp, "(no mode???)");
772 		    nfrontp += strlen(nfrontp);
773 		    break;
774 		}
775 		{
776 		    char tbuf[32];
777 		    sprintf(tbuf, "%s%s%s%s%s",
778 			pointer[2]&MODE_EDIT ? "|EDIT" : "",
779 			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
780 			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
781 			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
782 			pointer[2]&MODE_ACK ? "|ACK" : "");
783 		    sprintf(nfrontp, "%s", tbuf[1] ? &tbuf[1] : "0");
784 		    nfrontp += strlen(nfrontp);
785 		}
786 		if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
787 		    sprintf(nfrontp, " (0x%x)", pointer[2]);
788 		    nfrontp += strlen(nfrontp);
789 		}
790 		for (i = 3; i < length; i++) {
791 		    sprintf(nfrontp, " ?0x%x?", pointer[i]);
792 		    nfrontp += strlen(nfrontp);
793 		}
794 		break;
795 	    default:
796 		sprintf(nfrontp, "%d (unknown)", pointer[1]);
797 		nfrontp += strlen(nfrontp);
798 		for (i = 2; i < length; i++) {
799 		    sprintf(nfrontp, " %d", pointer[i]);
800 		    nfrontp += strlen(nfrontp);
801 		}
802 	    }
803 	    break;
804 
805 	case TELOPT_STATUS: {
806 	    register char *cp;
807 	    register int j, k;
808 
809 	    sprintf(nfrontp, "STATUS");
810 	    nfrontp += strlen(nfrontp);
811 
812 	    switch (pointer[1]) {
813 	    default:
814 		if (pointer[1] == TELQUAL_SEND)
815 		    sprintf(nfrontp, " SEND");
816 		else
817 		    sprintf(nfrontp, " %d (unknown)", pointer[1]);
818 		nfrontp += strlen(nfrontp);
819 		for (i = 2; i < length; i++) {
820 		    sprintf(nfrontp, " ?%d?", pointer[i]);
821 		    nfrontp += strlen(nfrontp);
822 		}
823 		break;
824 	    case TELQUAL_IS:
825 		sprintf(nfrontp, " IS\r\n");
826 		nfrontp += strlen(nfrontp);
827 
828 		for (i = 2; i < length; i++) {
829 		    switch(pointer[i]) {
830 		    case DO:	cp = "DO"; goto common2;
831 		    case DONT:	cp = "DONT"; goto common2;
832 		    case WILL:	cp = "WILL"; goto common2;
833 		    case WONT:	cp = "WONT"; goto common2;
834 		    common2:
835 			i++;
836 			if (TELOPT_OK((int)pointer[i]))
837 			    sprintf(nfrontp, " %s %s", cp, TELOPT(pointer[i]));
838 			else
839 			    sprintf(nfrontp, " %s %d", cp, pointer[i]);
840 			nfrontp += strlen(nfrontp);
841 
842 			sprintf(nfrontp, "\r\n");
843 			nfrontp += strlen(nfrontp);
844 			break;
845 
846 		    case SB:
847 			sprintf(nfrontp, " SB ");
848 			nfrontp += strlen(nfrontp);
849 			i++;
850 			j = k = i;
851 			while (j < length) {
852 			    if (pointer[j] == SE) {
853 				if (j+1 == length)
854 				    break;
855 				if (pointer[j+1] == SE)
856 				    j++;
857 				else
858 				    break;
859 			    }
860 			    pointer[k++] = pointer[j++];
861 			}
862 			printsub(0, &pointer[i], k - i);
863 			if (i < length) {
864 			    sprintf(nfrontp, " SE");
865 			    nfrontp += strlen(nfrontp);
866 			    i = j;
867 			} else
868 			    i = j - 1;
869 
870 			sprintf(nfrontp, "\r\n");
871 			nfrontp += strlen(nfrontp);
872 
873 			break;
874 
875 		    default:
876 			sprintf(nfrontp, " %d", pointer[i]);
877 			nfrontp += strlen(nfrontp);
878 			break;
879 		    }
880 		}
881 		break;
882 	    }
883 	    break;
884 	  }
885 
886 	case TELOPT_XDISPLOC:
887 	    sprintf(nfrontp, "X-DISPLAY-LOCATION ");
888 	    nfrontp += strlen(nfrontp);
889 	    switch (pointer[1]) {
890 	    case TELQUAL_IS:
891 		sprintf(nfrontp, "IS \"%.*s\"", length-2, (char *)pointer+2);
892 		break;
893 	    case TELQUAL_SEND:
894 		sprintf(nfrontp, "SEND");
895 		break;
896 	    default:
897 		sprintf(nfrontp, "- unknown qualifier %d (0x%x).",
898 				pointer[1], pointer[1]);
899 	    }
900 	    nfrontp += strlen(nfrontp);
901 	    break;
902 
903 	case TELOPT_ENVIRON:
904 	    sprintf(nfrontp, "ENVIRON ");
905 	    nfrontp += strlen(nfrontp);
906 	    switch (pointer[1]) {
907 	    case TELQUAL_IS:
908 		sprintf(nfrontp, "IS ");
909 		goto env_common;
910 	    case TELQUAL_SEND:
911 		sprintf(nfrontp, "SEND ");
912 		goto env_common;
913 	    case TELQUAL_INFO:
914 		sprintf(nfrontp, "INFO ");
915 	    env_common:
916 	    nfrontp += strlen(nfrontp);
917 		{
918 		    register int noquote = 2;
919 		    for (i = 2; i < length; i++ ) {
920 			switch (pointer[i]) {
921 			case ENV_VAR:
922 			    if (pointer[1] == TELQUAL_SEND)
923 				goto def_case;
924 			    sprintf(nfrontp, "\" VAR " + noquote);
925 			    nfrontp += strlen(nfrontp);
926 			    noquote = 2;
927 			    break;
928 
929 			case ENV_VALUE:
930 			    sprintf(nfrontp, "\" VALUE " + noquote);
931 			    nfrontp += strlen(nfrontp);
932 			    noquote = 2;
933 			    break;
934 
935 			case ENV_ESC:
936 			    sprintf(nfrontp, "\" ESC " + noquote);
937 			    nfrontp += strlen(nfrontp);
938 			    noquote = 2;
939 			    break;
940 
941 			default:
942 			def_case:
943 			    if (isprint(pointer[i]) && pointer[i] != '"') {
944 				if (noquote) {
945 				    *nfrontp++ = '"';
946 				    noquote = 0;
947 				}
948 				*nfrontp++ = pointer[i];
949 			    } else {
950 				sprintf(nfrontp, "\" %03o " + noquote,
951 							pointer[i]);
952 				nfrontp += strlen(nfrontp);
953 				noquote = 2;
954 			    }
955 			    break;
956 			}
957 		    }
958 		    if (!noquote)
959 			*nfrontp++ = '"';
960 		    break;
961 		}
962 	    }
963 	    break;
964 
965 #if	defined(AUTHENTICATE)
966 	case TELOPT_AUTHENTICATION:
967 	    sprintf(nfrontp, "AUTHENTICATION");
968 	    nfrontp += strlen(nfrontp);
969 
970 	    if (length < 2) {
971 		sprintf(nfrontp, " (empty suboption???)");
972 		nfrontp += strlen(nfrontp);
973 		break;
974 	    }
975 	    switch (pointer[1]) {
976 	    case TELQUAL_REPLY:
977 	    case TELQUAL_IS:
978 		sprintf(nfrontp, " %s ", (pointer[1] == TELQUAL_IS) ?
979 							"IS" : "REPLY");
980 		nfrontp += strlen(nfrontp);
981 		if (AUTHTYPE_NAME_OK(pointer[2]))
982 		    sprintf(nfrontp, "%s ", AUTHTYPE_NAME(pointer[2]));
983 		else
984 		    sprintf(nfrontp, "%d ", pointer[2]);
985 		nfrontp += strlen(nfrontp);
986 		if (length < 3) {
987 		    sprintf(nfrontp, "(partial suboption???)");
988 		    nfrontp += strlen(nfrontp);
989 		    break;
990 		}
991 		sprintf(nfrontp, "%s|%s",
992 			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
993 			"CLIENT" : "SERVER",
994 			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
995 			"MUTUAL" : "ONE-WAY");
996 		nfrontp += strlen(nfrontp);
997 
998 		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
999 		sprintf(nfrontp, "%s", buf);
1000 		nfrontp += strlen(nfrontp);
1001 		break;
1002 
1003 	    case TELQUAL_SEND:
1004 		i = 2;
1005 		sprintf(nfrontp, " SEND ");
1006 		nfrontp += strlen(nfrontp);
1007 		while (i < length) {
1008 		    if (AUTHTYPE_NAME_OK(pointer[i]))
1009 			sprintf(nfrontp, "%s ", AUTHTYPE_NAME(pointer[i]));
1010 		    else
1011 			sprintf(nfrontp, "%d ", pointer[i]);
1012 		    nfrontp += strlen(nfrontp);
1013 		    if (++i >= length) {
1014 			sprintf(nfrontp, "(partial suboption???)");
1015 			nfrontp += strlen(nfrontp);
1016 			break;
1017 		    }
1018 		    sprintf(nfrontp, "%s|%s ",
1019 			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
1020 							"CLIENT" : "SERVER",
1021 			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
1022 							"MUTUAL" : "ONE-WAY");
1023 		    nfrontp += strlen(nfrontp);
1024 		    ++i;
1025 		}
1026 		break;
1027 
1028 	    case TELQUAL_NAME:
1029 		i = 2;
1030 		sprintf(nfrontp, " NAME \"");
1031 		nfrontp += strlen(nfrontp);
1032 		while (i < length)
1033 		    *nfrontp += pointer[i++];
1034 		*nfrontp += '"';
1035 		break;
1036 
1037 	    default:
1038 		    for (i = 2; i < length; i++) {
1039 			sprintf(nfrontp, " ?%d?", pointer[i]);
1040 			nfrontp += strlen(nfrontp);
1041 		    }
1042 		    break;
1043 	    }
1044 	    break;
1045 #endif
1046 
1047 #if	defined(ENCRYPT)
1048 	case TELOPT_ENCRYPT:
1049 	    sprintf(nfrontp, "ENCRYPT");
1050 	    nfrontp += strlen(nfrontp);
1051 	    if (length < 2) {
1052 		sprintf(nfrontp, " (empty suboption???)");
1053 		nfrontp += strlen(nfrontp);
1054 		break;
1055 	    }
1056 	    switch (pointer[1]) {
1057 	    case ENCRYPT_START:
1058 		sprintf(nfrontp, " START");
1059 		nfrontp += strlen(nfrontp);
1060 		break;
1061 
1062 	    case ENCRYPT_END:
1063 		sprintf(nfrontp, " END");
1064 		nfrontp += strlen(nfrontp);
1065 		break;
1066 
1067 	    case ENCRYPT_REQSTART:
1068 		sprintf(nfrontp, " REQUEST-START");
1069 		nfrontp += strlen(nfrontp);
1070 		break;
1071 
1072 	    case ENCRYPT_REQEND:
1073 		sprintf(nfrontp, " REQUEST-END");
1074 		nfrontp += strlen(nfrontp);
1075 		break;
1076 
1077 	    case ENCRYPT_IS:
1078 	    case ENCRYPT_REPLY:
1079 		sprintf(nfrontp, " %s ", (pointer[1] == ENCRYPT_IS) ?
1080 							"IS" : "REPLY");
1081 		nfrontp += strlen(nfrontp);
1082 		if (length < 3) {
1083 		    sprintf(nfrontp, " (partial suboption???)");
1084 		    nfrontp += strlen(nfrontp);
1085 		    break;
1086 		}
1087 		if (ENCTYPE_NAME_OK(pointer[2]))
1088 		    sprintf(nfrontp, "%s ", ENCTYPE_NAME(pointer[2]));
1089 		else
1090 		    sprintf(nfrontp, " %d (unknown)", pointer[2]);
1091 		nfrontp += strlen(nfrontp);
1092 
1093 		encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
1094 		sprintf(nfrontp, "%s", buf);
1095 		nfrontp += strlen(nfrontp);
1096 		break;
1097 
1098 	    case ENCRYPT_SUPPORT:
1099 		i = 2;
1100 		sprintf(nfrontp, " SUPPORT ");
1101 		nfrontp += strlen(nfrontp);
1102 		while (i < length) {
1103 		    if (ENCTYPE_NAME_OK(pointer[i]))
1104 			sprintf(nfrontp, "%s ", ENCTYPE_NAME(pointer[i]));
1105 		    else
1106 			sprintf(nfrontp, "%d ", pointer[i]);
1107 		    nfrontp += strlen(nfrontp);
1108 		    i++;
1109 		}
1110 		break;
1111 
1112 	    case ENCRYPT_ENC_KEYID:
1113 		sprintf(nfrontp, " ENC_KEYID", pointer[1]);
1114 		nfrontp += strlen(nfrontp);
1115 		goto encommon;
1116 
1117 	    case ENCRYPT_DEC_KEYID:
1118 		sprintf(nfrontp, " DEC_KEYID", pointer[1]);
1119 		nfrontp += strlen(nfrontp);
1120 		goto encommon;
1121 
1122 	    default:
1123 		sprintf(nfrontp, " %d (unknown)", pointer[1]);
1124 		nfrontp += strlen(nfrontp);
1125 	    encommon:
1126 		for (i = 2; i < length; i++) {
1127 		    sprintf(nfrontp, " %d", pointer[i]);
1128 		    nfrontp += strlen(nfrontp);
1129 		}
1130 		break;
1131 	    }
1132 	    break;
1133 #endif
1134 
1135 	default:
1136 	    if (TELOPT_OK(pointer[0]))
1137 	        sprintf(nfrontp, "%s (unknown)", TELOPT(pointer[0]));
1138 	    else
1139 	        sprintf(nfrontp, "%d (unknown)", pointer[i]);
1140 	    nfrontp += strlen(nfrontp);
1141 	    for (i = 1; i < length; i++) {
1142 		sprintf(nfrontp, " %d", pointer[i]);
1143 		nfrontp += strlen(nfrontp);
1144 	    }
1145 	    break;
1146 	}
1147 	sprintf(nfrontp, "\r\n");
1148 	nfrontp += strlen(nfrontp);
1149 }
1150 
1151 /*
1152  * Dump a data buffer in hex and ascii to the output data stream.
1153  */
1154 	void
1155 printdata(tag, ptr, cnt)
1156 	register char *tag;
1157 	register char *ptr;
1158 	register int cnt;
1159 {
1160 	register int i;
1161 	char xbuf[30];
1162 
1163 	while (cnt) {
1164 		/* flush net output buffer if no room for new data) */
1165 		if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1166 			netflush();
1167 		}
1168 
1169 		/* add a line of output */
1170 		sprintf(nfrontp, "%s: ", tag);
1171 		nfrontp += strlen(nfrontp);
1172 		for (i = 0; i < 20 && cnt; i++) {
1173 			sprintf(nfrontp, "%02x", *ptr);
1174 			nfrontp += strlen(nfrontp);
1175 			if (isprint(*ptr)) {
1176 				xbuf[i] = *ptr;
1177 			} else {
1178 				xbuf[i] = '.';
1179 			}
1180 			if (i % 2) {
1181 				*nfrontp = ' ';
1182 				nfrontp++;
1183 			}
1184 			cnt--;
1185 			ptr++;
1186 		}
1187 		xbuf[i] = '\0';
1188 		sprintf(nfrontp, " %s\r\n", xbuf );
1189 		nfrontp += strlen(nfrontp);
1190 	}
1191 }
1192 #endif /* DIAGNOSTICS */
1193