xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.bin/telnet/telnet.c (revision 069e6b7e31ba5dcbc5441b98af272714d9a5455c)
1 /*
2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1988, 1990, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #ifndef lint
40 static char sccsid[] = "@(#)telnet.c	8.1 (Berkeley) 6/6/93";
41 #endif /* not lint */
42 
43 #include <netdb.h>
44 #include <sys/types.h>
45 
46 #include <curses.h>
47 #include <signal.h>
48 /*
49  * By the way, we need to include curses.h before telnet.h since,
50  * among other things, telnet.h #defines 'DO', which is a variable
51  * declared in curses.h.
52  */
53 
54 #include <arpa/telnet.h>
55 
56 #include <ctype.h>
57 
58 #include "ring.h"
59 
60 #include "defines.h"
61 #include "externs.h"
62 #include "types.h"
63 #include "general.h"
64 
65 #include "auth.h"
66 #include "encrypt.h"
67 
68 #define	strip(x)	((x)&0x7f)
69 
70 /* Buffer for sub-options */
71 static unsigned char	subbuffer[SUBBUFSIZE];
72 static unsigned char	*subpointer;
73 static unsigned char	*subend;
74 
75 #define	SB_CLEAR()	subpointer = subbuffer;
76 #define	SB_TERM()	{ subend = subpointer; SB_CLEAR(); }
77 #define	SB_ACCUM(c)	if (subpointer < (subbuffer+sizeof (subbuffer))) { \
78 				*subpointer++ = (c); \
79 			}
80 
81 #define	SB_GET()	((*subpointer++)&0xff)
82 #define	SB_PEEK()	((*subpointer)&0xff)
83 #define	SB_EOF()	(subpointer >= subend)
84 #define	SB_LEN()	(subend - subpointer)
85 
86 char	options[SUBBUFSIZE];		/* The combined options */
87 char	do_dont_resp[SUBBUFSIZE];
88 char	will_wont_resp[SUBBUFSIZE];
89 
90 int eight = 0;
91 int autologin = 0;	/* Autologin anyone? */
92 int skiprc = 0;
93 int connected;
94 int showoptions;
95 static int ISend;	/* trying to send network data in */
96 int debug = 0;
97 int crmod;
98 int netdata;		/* Print out network data flow */
99 int crlf;		/* Should '\r' be mapped to <CR><LF> (or <CR><NUL>)? */
100 int telnetport;
101 int SYNCHing;		/* we are in TELNET SYNCH mode */
102 int flushout;		/* flush output */
103 int autoflush = 0;	/* flush output when interrupting? */
104 int autosynch;		/* send interrupt characters with SYNCH? */
105 int localflow;		/* we handle flow control locally */
106 int restartany;		/* if flow control enabled, restart on any character */
107 int localchars;		/* we recognize interrupt/quit */
108 int donelclchars;	/* the user has set "localchars" */
109 int donebinarytoggle;	/* the user has put us in binary */
110 int dontlecho;		/* do we suppress local echoing right now? */
111 int eof_pending = 0;	/* we received a genuine EOF on input, send IAC-EOF */
112 int globalmode;
113 
114 /* spin while waiting for authentication */
115 boolean_t scheduler_lockout_tty = B_FALSE;
116 int encrypt_flag = 0;
117 int forwardable_flag = 0;
118 int forward_flag = 0;
119 boolean_t wantencryption = B_FALSE;
120 
121 char *prompt = 0;
122 
123 cc_t escape;
124 cc_t rlogin;
125 boolean_t escape_valid = B_TRUE;
126 #ifdef	KLUDGELINEMODE
127 cc_t echoc;
128 #endif
129 
130 /*
131  * Telnet receiver states for fsm
132  */
133 #define	TS_DATA		0
134 #define	TS_IAC		1
135 #define	TS_WILL		2
136 #define	TS_WONT		3
137 #define	TS_DO		4
138 #define	TS_DONT		5
139 #define	TS_CR		6
140 #define	TS_SB		7		/* sub-option collection */
141 #define	TS_SE		8		/* looking for sub-option end */
142 
143 static int	telrcv_state;
144 #ifdef	OLD_ENVIRON
145 static	unsigned char telopt_environ = TELOPT_NEW_ENVIRON;
146 #else
147 #define	telopt_environ	TELOPT_NEW_ENVIRON
148 #endif
149 
150 jmp_buf	toplevel = { 0 };
151 jmp_buf	peerdied;
152 
153 static int flushline;
154 int	linemode;
155 
156 int	reqd_linemode = 0; /* Set if either new or old line mode in */
157 			/* effect since before initial negotiations */
158 
159 #ifdef	KLUDGELINEMODE
160 int	kludgelinemode = 1;
161 #endif
162 
163 /*
164  * The following are some clocks used to decide how to interpret
165  * the relationship between various variables.
166  */
167 
168 Clocks clocks;
169 
170 #ifdef	notdef
171 Modelist modelist[] = {
172 	{ "telnet command mode", COMMAND_LINE },
173 	{ "character-at-a-time mode", 0 },
174 	{ "character-at-a-time mode (local echo)", LOCAL_ECHO|LOCAL_CHARS },
175 	{ "line-by-line mode (remote echo)", LINE | LOCAL_CHARS },
176 	{ "line-by-line mode", LINE | LOCAL_ECHO | LOCAL_CHARS },
177 	{ "line-by-line mode (local echoing suppressed)", LINE | LOCAL_CHARS },
178 	{ "3270 mode", 0 },
179 };
180 #endif
181 
182 static void willoption(int);
183 static void wontoption(int);
184 static void lm_will(unsigned char *, int);
185 static void lm_wont(unsigned char *, int);
186 static void lm_do(unsigned char *, int);
187 static void lm_dont(unsigned char *, int);
188 static void slc_init(void);
189 static void slc_import(int);
190 static void slc_export(void);
191 static void slc_start_reply(size_t);
192 static void slc_add_reply(unsigned char, unsigned char, cc_t);
193 static void slc_end_reply(void);
194 static void slc(unsigned char *, int);
195 static int slc_update(void);
196 static void env_opt(unsigned char *, int);
197 static void env_opt_start(void);
198 static void sendeof(void);
199 static int is_unique(register char *, register char **, register char **);
200 
201 /*
202  * Initialize telnet environment.
203  */
204 
205 int
206 init_telnet()
207 {
208 	if (env_init() == 0)
209 		return (0);
210 
211 	SB_CLEAR();
212 	ClearArray(options);
213 
214 	connected = ISend = localflow = donebinarytoggle = 0;
215 	restartany = -1;
216 
217 	SYNCHing = 0;
218 
219 	/* Don't change NetTrace */
220 
221 	escape = CONTROL(']');
222 	rlogin = _POSIX_VDISABLE;
223 #ifdef	KLUDGELINEMODE
224 	echoc = CONTROL('E');
225 #endif
226 
227 	flushline = 1;
228 	telrcv_state = TS_DATA;
229 
230 	return (1);
231 }
232 
233 
234 #ifdef	notdef
235 #include <varargs.h>
236 
237 /*VARARGS*/
238 static void
239 printring(va_alist)
240 	va_dcl
241 {
242 	va_list ap;
243 	char buffer[100];		/* where things go */
244 	char *ptr;
245 	char *format;
246 	char *string;
247 	Ring *ring;
248 	int i;
249 
250 	va_start(ap);
251 
252 	ring = va_arg(ap, Ring *);
253 	format = va_arg(ap, char *);
254 	ptr = buffer;
255 
256 	while ((i = *format++) != 0) {
257 		if (i == '%') {
258 			i = *format++;
259 			switch (i) {
260 			case 'c':
261 				*ptr++ = va_arg(ap, int);
262 				break;
263 			case 's':
264 				string = va_arg(ap, char *);
265 				ring_supply_data(ring, buffer, ptr-buffer);
266 				ring_supply_data(ring, string, strlen(string));
267 				ptr = buffer;
268 				break;
269 			case 0:
270 				ExitString("printring: trailing %%.\n",
271 				    EXIT_FAILURE);
272 				/*NOTREACHED*/
273 			default:
274 				ExitString("printring: unknown format "
275 				    "character.\n", EXIT_FAILURE);
276 				/*NOTREACHED*/
277 			}
278 		} else {
279 			*ptr++ = i;
280 		}
281 	}
282 	ring_supply_data(ring, buffer, ptr-buffer);
283 }
284 #endif
285 
286 /*
287  * These routines are in charge of sending option negotiations
288  * to the other side.
289  *
290  * The basic idea is that we send the negotiation if either side
291  * is in disagreement as to what the current state should be.
292  */
293 
294 void
295 send_do(c, init)
296 	register int c, init;
297 {
298 	if (init) {
299 		if (((do_dont_resp[c] == 0) && my_state_is_do(c)) ||
300 		    my_want_state_is_do(c))
301 			return;
302 		set_my_want_state_do(c);
303 		do_dont_resp[c]++;
304 	}
305 	NET2ADD(IAC, DO);
306 	NETADD(c);
307 	printoption("SENT", DO, c);
308 }
309 
310 void
311 send_dont(c, init)
312 	register int c, init;
313 {
314 	if (init) {
315 		if (((do_dont_resp[c] == 0) && my_state_is_dont(c)) ||
316 		    my_want_state_is_dont(c))
317 			return;
318 		set_my_want_state_dont(c);
319 		do_dont_resp[c]++;
320 	}
321 	NET2ADD(IAC, DONT);
322 	NETADD(c);
323 	printoption("SENT", DONT, c);
324 }
325 
326 void
327 send_will(c, init)
328 	register int c, init;
329 {
330 	if (init) {
331 		if (((will_wont_resp[c] == 0) && my_state_is_will(c)) ||
332 		    my_want_state_is_will(c))
333 			return;
334 		set_my_want_state_will(c);
335 		will_wont_resp[c]++;
336 	}
337 	NET2ADD(IAC, WILL);
338 	NETADD(c);
339 	printoption("SENT", WILL, c);
340 }
341 
342 void
343 send_wont(c, init)
344 	register int c, init;
345 {
346 	if (init) {
347 		if (((will_wont_resp[c] == 0) && my_state_is_wont(c)) ||
348 		    my_want_state_is_wont(c))
349 			return;
350 		set_my_want_state_wont(c);
351 		will_wont_resp[c]++;
352 	}
353 	NET2ADD(IAC, WONT);
354 	NETADD(c);
355 	printoption("SENT", WONT, c);
356 }
357 
358 
359 static void
360 willoption(option)
361 	int option;
362 {
363 	int new_state_ok = 0;
364 
365 	if (do_dont_resp[option]) {
366 	    --do_dont_resp[option];
367 	    if (do_dont_resp[option] && my_state_is_do(option))
368 		--do_dont_resp[option];
369 	}
370 
371 	if ((do_dont_resp[option] == 0) && my_want_state_is_dont(option)) {
372 
373 	    switch (option) {
374 
375 	    case TELOPT_ECHO:
376 	    case TELOPT_SGA:
377 		if (reqd_linemode && my_state_is_dont(option)) {
378 		    break;
379 		}
380 		/* FALLTHROUGH */
381 	    case TELOPT_BINARY:
382 		settimer(modenegotiated);
383 		/* FALLTHROUGH */
384 	    case TELOPT_STATUS:
385 	    case TELOPT_AUTHENTICATION:
386 		/* FALLTHROUGH */
387 	    case TELOPT_ENCRYPT:
388 		new_state_ok = 1;
389 		break;
390 
391 	    case TELOPT_TM:
392 		if (flushout)
393 		    flushout = 0;
394 		/*
395 		 * Special case for TM.  If we get back a WILL,
396 		 * pretend we got back a WONT.
397 		 */
398 		set_my_want_state_dont(option);
399 		set_my_state_dont(option);
400 		return;			/* Never reply to TM will's/wont's */
401 
402 	    case TELOPT_LINEMODE:
403 	    default:
404 		break;
405 	    }
406 
407 	    if (new_state_ok) {
408 		set_my_want_state_do(option);
409 		send_do(option, 0);
410 		setconnmode(0);		/* possibly set new tty mode */
411 	    } else {
412 		do_dont_resp[option]++;
413 		send_dont(option, 0);
414 	    }
415 	}
416 	set_my_state_do(option);
417 	if (option == TELOPT_ENCRYPT)
418 		encrypt_send_support();
419 }
420 
421 static void
422 wontoption(option)
423 	int option;
424 {
425 	if (do_dont_resp[option]) {
426 		--do_dont_resp[option];
427 		if (do_dont_resp[option] && my_state_is_dont(option))
428 			--do_dont_resp[option];
429 	}
430 
431 	if ((do_dont_resp[option] == 0) && my_want_state_is_do(option)) {
432 
433 		switch (option) {
434 
435 #ifdef	KLUDGELINEMODE
436 		case TELOPT_SGA:
437 			if (!kludgelinemode)
438 				break;
439 			/* FALLTHROUGH */
440 #endif
441 		case TELOPT_ECHO:
442 			settimer(modenegotiated);
443 			break;
444 
445 		case TELOPT_TM:
446 			if (flushout)
447 				flushout = 0;
448 			set_my_want_state_dont(option);
449 			set_my_state_dont(option);
450 			return;		/* Never reply to TM will's/wont's */
451 
452 		default:
453 			break;
454 		}
455 		set_my_want_state_dont(option);
456 		if (my_state_is_do(option))
457 			send_dont(option, 0);
458 		setconnmode(0);			/* Set new tty mode */
459 	} else if (option == TELOPT_TM) {
460 		/*
461 		 * Special case for TM.
462 		 */
463 		if (flushout)
464 			flushout = 0;
465 		set_my_want_state_dont(option);
466 	}
467 	set_my_state_dont(option);
468 }
469 
470 static void
471 dooption(option)
472 	int option;
473 {
474 	int new_state_ok = 0;
475 
476 	if (will_wont_resp[option]) {
477 		--will_wont_resp[option];
478 		if (will_wont_resp[option] && my_state_is_will(option))
479 			--will_wont_resp[option];
480 	}
481 
482 	if (will_wont_resp[option] == 0) {
483 		if (my_want_state_is_wont(option)) {
484 
485 			switch (option) {
486 
487 			case TELOPT_TM:
488 				/*
489 				 * Special case for TM.  We send a WILL,
490 				 * but pretend we sent WONT.
491 				 */
492 				send_will(option, 0);
493 				set_my_want_state_wont(TELOPT_TM);
494 				set_my_state_wont(TELOPT_TM);
495 				return;
496 
497 			case TELOPT_BINARY:	/* binary mode */
498 			case TELOPT_NAWS:	/* window size */
499 			case TELOPT_TSPEED:	/* terminal speed */
500 			case TELOPT_LFLOW:	/* local flow control */
501 			case TELOPT_TTYPE:	/* terminal type option */
502 			case TELOPT_SGA:	/* no big deal */
503 			case TELOPT_ENCRYPT:	/* encryption variable option */
504 				new_state_ok = 1;
505 				break;
506 
507 			case TELOPT_NEW_ENVIRON:
508 				/* New environment variable option */
509 #ifdef	OLD_ENVIRON
510 				if (my_state_is_will(TELOPT_OLD_ENVIRON))
511 					/* turn off the old */
512 					send_wont(TELOPT_OLD_ENVIRON, 1);
513 goto env_common;
514 			case TELOPT_OLD_ENVIRON:
515 				/* Old environment variable option */
516 				if (my_state_is_will(TELOPT_NEW_ENVIRON))
517 					/* Don't enable if new one is in use! */
518 					break;
519 env_common:
520 				telopt_environ = option;
521 #endif
522 				new_state_ok = 1;
523 				break;
524 
525 			case TELOPT_AUTHENTICATION:
526 				if (autologin)
527 					new_state_ok = 1;
528 				break;
529 
530 			case TELOPT_XDISPLOC:	/* X Display location */
531 				if (env_getvalue((unsigned char *)"DISPLAY"))
532 					new_state_ok = 1;
533 				break;
534 
535 			case TELOPT_LINEMODE:
536 #ifdef	KLUDGELINEMODE
537 				kludgelinemode = 0;
538 				send_do(TELOPT_SGA, 1);
539 #endif
540 				set_my_want_state_will(TELOPT_LINEMODE);
541 				send_will(option, 0);
542 				set_my_state_will(TELOPT_LINEMODE);
543 				slc_init();
544 				return;
545 
546 			case TELOPT_ECHO: /* We're never going to echo... */
547 			default:
548 				break;
549 			}
550 
551 			if (new_state_ok) {
552 				set_my_want_state_will(option);
553 				send_will(option, 0);
554 				setconnmode(0);		/* Set new tty mode */
555 			} else {
556 				will_wont_resp[option]++;
557 				send_wont(option, 0);
558 			}
559 		} else {
560 			/*
561 			 * Handle options that need more things done after the
562 			 * other side has acknowledged the option.
563 			 */
564 			switch (option) {
565 			case TELOPT_LINEMODE:
566 #ifdef	KLUDGELINEMODE
567 				kludgelinemode = 0;
568 				send_do(TELOPT_SGA, 1);
569 #endif
570 				set_my_state_will(option);
571 				slc_init();
572 				send_do(TELOPT_SGA, 0);
573 				return;
574 			}
575 		}
576 	}
577 	set_my_state_will(option);
578 }
579 
580 	static void
581 dontoption(option)
582 	int option;
583 {
584 
585 	if (will_wont_resp[option]) {
586 	    --will_wont_resp[option];
587 	    if (will_wont_resp[option] && my_state_is_wont(option))
588 		--will_wont_resp[option];
589 	}
590 
591 	if ((will_wont_resp[option] == 0) && my_want_state_is_will(option)) {
592 	    switch (option) {
593 	    case TELOPT_LINEMODE:
594 		linemode = 0;	/* put us back to the default state */
595 		break;
596 #ifdef	OLD_ENVIRON
597 	    case TELOPT_NEW_ENVIRON:
598 		/*
599 		 * The new environ option wasn't recognized, try
600 		 * the old one.
601 		 */
602 		send_will(TELOPT_OLD_ENVIRON, 1);
603 		telopt_environ = TELOPT_OLD_ENVIRON;
604 		break;
605 #endif
606 	    }
607 	    /* we always accept a DONT */
608 	    set_my_want_state_wont(option);
609 	    if (my_state_is_will(option))
610 		send_wont(option, 0);
611 	    setconnmode(0);			/* Set new tty mode */
612 	}
613 	set_my_state_wont(option);
614 }
615 
616 /*
617  * Given a buffer returned by tgetent(), this routine will turn
618  * the pipe seperated list of names in the buffer into an array
619  * of pointers to null terminated names.  We toss out any bad,
620  * duplicate, or verbose names (names with spaces).
621  */
622 
623 static char *name_unknown = "UNKNOWN";
624 static char *unknown[] = { 0, 0 };
625 
626 static char **
627 mklist(buf, name)
628 	char *buf, *name;
629 {
630 	register int n;
631 	register char c, *cp, **argvp, *cp2, **argv, **avt;
632 
633 	if (name) {
634 		if (strlen(name) > 40u) {
635 			name = 0;
636 			unknown[0] = name_unknown;
637 		} else {
638 			unknown[0] = name;
639 			upcase(name);
640 		}
641 	} else
642 		unknown[0] = name_unknown;
643 	/*
644 	 * Count up the number of names.
645 	 */
646 	for (n = 1, cp = buf; *cp && *cp != ':'; cp++) {
647 		if (*cp == '|')
648 			n++;
649 	}
650 	/*
651 	 * Allocate an array to put the name pointers into
652 	 */
653 	argv = malloc((n+3)*sizeof (char *));
654 	if (argv == 0)
655 		return (unknown);
656 
657 	/*
658 	 * Fill up the array of pointers to names.
659 	 */
660 	*argv = 0;
661 	argvp = argv+1;
662 	n = 0;
663 	for (cp = cp2 = buf; (c = *cp) != '\0';  cp++) {
664 		if (c == '|' || c == ':') {
665 			*cp++ = '\0';
666 			/*
667 			 * Skip entries that have spaces or are over 40
668 			 * characters long.  If this is our environment
669 			 * name, then put it up front.  Otherwise, as
670 			 * long as this is not a duplicate name (case
671 			 * insensitive) add it to the list.
672 			 */
673 			if (n || (cp - cp2 > 41))
674 				/* EMPTY */;
675 			else if (name && (strncasecmp(name, cp2, cp-cp2) == 0))
676 				*argv = cp2;
677 			else if (is_unique(cp2, argv+1, argvp))
678 				*argvp++ = cp2;
679 			if (c == ':')
680 				break;
681 			/*
682 			 * Skip multiple delimiters. Reset cp2 to
683 			 * the beginning of the next name. Reset n,
684 			 * the flag for names with spaces.
685 			 */
686 			while ((c = *cp) == '|')
687 				cp++;
688 			cp2 = cp;
689 			n = 0;
690 		}
691 		/*
692 		 * Skip entries with spaces or non-ascii values.
693 		 * Convert lower case letters to upper case.
694 		 */
695 		if ((c == ' ') || !isascii(c))
696 			n = 1;
697 		else if (islower(c))
698 			*cp = toupper(c);
699 	}
700 
701 	/*
702 	 * Check for an old V6 2 character name.  If the second
703 	 * name points to the beginning of the buffer, and is
704 	 * only 2 characters long, move it to the end of the array.
705 	 */
706 	if ((argv[1] == buf) && (strlen(argv[1]) == 2)) {
707 		--argvp;
708 		for (avt = &argv[1]; avt < argvp; avt++)
709 			*avt = *(avt+1);
710 		*argvp++ = buf;
711 	}
712 
713 	/*
714 	 * Duplicate last name, for TTYPE option, and null
715 	 * terminate the array.  If we didn't find a match on
716 	 * our terminal name, put that name at the beginning.
717 	 */
718 	cp = *(argvp-1);
719 	*argvp++ = cp;
720 	*argvp = 0;
721 
722 	if (*argv == 0) {
723 		if (name)
724 			*argv = name;
725 		else {
726 			--argvp;
727 			for (avt = argv; avt < argvp; avt++)
728 				*avt = *(avt+1);
729 		}
730 	}
731 	if (*argv)
732 		return (argv);
733 	else
734 		return (unknown);
735 }
736 
737 static int
738 is_unique(name, as, ae)
739 	register char *name, **as, **ae;
740 {
741 	register char **ap;
742 	register int n;
743 
744 	n = strlen(name) + 1;
745 	for (ap = as; ap < ae; ap++)
746 		if (strncasecmp(*ap, name, n) == 0)
747 			return (0);
748 	return (1);
749 }
750 
751 #define	termbuf	ttytype
752 extern char ttytype[];
753 
754 int resettermname = 1;
755 
756 static char *
757 gettermname(void)
758 {
759 	char *tname;
760 	static char **tnamep = 0;
761 	static char **next;
762 	int err;
763 
764 	if (resettermname) {
765 		resettermname = 0;
766 		if (tnamep && tnamep != unknown)
767 			free(tnamep);
768 		tname = (char *)env_getvalue((unsigned char *)"TERM");
769 		if ((tname != NULL) && (setupterm(tname, 1, &err) == 0)) {
770 			tnamep = mklist(termbuf, tname);
771 		} else {
772 			if (tname && (strlen(tname) <= 40u)) {
773 				unknown[0] = tname;
774 				upcase(tname);
775 			} else
776 				unknown[0] = name_unknown;
777 			tnamep = unknown;
778 		}
779 		next = tnamep;
780 	}
781 	if (*next == 0)
782 		next = tnamep;
783 	return (*next++);
784 }
785 /*
786  * suboption()
787  *
788  *	Look at the sub-option buffer, and try to be helpful to the other
789  * side.
790  *
791  *	Currently we recognize:
792  *
793  *		Terminal type, send request.
794  *		Terminal speed (send request).
795  *		Local flow control (is request).
796  *		Linemode
797  */
798 
799     static void
800 suboption()
801 {
802 	unsigned char subchar;
803 
804 	printsub('<', subbuffer, SB_LEN()+2);
805 	switch (subchar = SB_GET()) {
806 	case TELOPT_TTYPE:
807 		if (my_want_state_is_wont(TELOPT_TTYPE))
808 			return;
809 		if (SB_EOF() || SB_GET() != TELQUAL_SEND) {
810 			return;
811 		} else {
812 			char *name;
813 			unsigned char temp[50];
814 			int len, bytes;
815 
816 			name = gettermname();
817 			len = strlen(name) + 4 + 2;
818 			bytes = snprintf((char *)temp, sizeof (temp),
819 				"%c%c%c%c%s%c%c", IAC, SB,
820 				TELOPT_TTYPE, TELQUAL_IS, name, IAC, SE);
821 			if ((len < NETROOM()) && (bytes < sizeof (temp))) {
822 					ring_supply_data(&netoring, temp, len);
823 					printsub('>', &temp[2], len-2);
824 			} else {
825 				ExitString("No room in buffer for "
826 				    "terminal type.\n", EXIT_FAILURE);
827 				/*NOTREACHED*/
828 			}
829 		}
830 		break;
831 	case TELOPT_TSPEED:
832 		if (my_want_state_is_wont(TELOPT_TSPEED))
833 			return;
834 		if (SB_EOF())
835 			return;
836 		if (SB_GET() == TELQUAL_SEND) {
837 			int ospeed, ispeed;
838 			unsigned char temp[50];
839 			int len, bytes;
840 
841 			TerminalSpeeds(&ispeed, &ospeed);
842 
843 			bytes = snprintf((char *)temp, sizeof (temp),
844 			    "%c%c%c%c%d,%d%c%c", IAC, SB,
845 			    TELOPT_TSPEED, TELQUAL_IS, ospeed, ispeed, IAC, SE);
846 			len = strlen((char *)temp+4) + 4; /* temp[3] is 0 ... */
847 
848 			if ((len < NETROOM()) && (bytes < sizeof (temp))) {
849 				ring_supply_data(&netoring, temp, len);
850 				printsub('>', temp+2, len - 2);
851 			}
852 			else
853 				(void) printf(
854 				    "telnet: not enough room in buffer "
855 				    "for terminal speed option reply\n");
856 		}
857 		break;
858 	case TELOPT_LFLOW:
859 		if (my_want_state_is_wont(TELOPT_LFLOW))
860 			return;
861 		if (SB_EOF())
862 			return;
863 		switch (SB_GET()) {
864 		case LFLOW_RESTART_ANY:
865 			restartany = 1;
866 			break;
867 		case LFLOW_RESTART_XON:
868 			restartany = 0;
869 			break;
870 		case LFLOW_ON:
871 			localflow = 1;
872 			break;
873 		case LFLOW_OFF:
874 			localflow = 0;
875 			break;
876 		default:
877 			return;
878 		}
879 		setcommandmode();
880 		setconnmode(0);
881 		break;
882 
883 	case TELOPT_LINEMODE:
884 		if (my_want_state_is_wont(TELOPT_LINEMODE))
885 			return;
886 		if (SB_EOF())
887 			return;
888 		switch (SB_GET()) {
889 		case WILL:
890 			lm_will(subpointer, SB_LEN());
891 			break;
892 		case WONT:
893 			lm_wont(subpointer, SB_LEN());
894 			break;
895 		case DO:
896 			lm_do(subpointer, SB_LEN());
897 			break;
898 		case DONT:
899 			lm_dont(subpointer, SB_LEN());
900 			break;
901 		case LM_SLC:
902 			slc(subpointer, SB_LEN());
903 			break;
904 		case LM_MODE:
905 			lm_mode(subpointer, SB_LEN(), 0);
906 			break;
907 		default:
908 			break;
909 		}
910 		break;
911 
912 #ifdef	OLD_ENVIRON
913 	case TELOPT_OLD_ENVIRON:
914 #endif
915 	case TELOPT_NEW_ENVIRON:
916 		if (SB_EOF())
917 			return;
918 		switch (SB_PEEK()) {
919 		case TELQUAL_IS:
920 		case TELQUAL_INFO:
921 			if (my_want_state_is_dont(subchar))
922 				return;
923 			break;
924 		case TELQUAL_SEND:
925 			if (my_want_state_is_wont(subchar)) {
926 				return;
927 			}
928 			break;
929 		default:
930 			return;
931 		}
932 		env_opt(subpointer, SB_LEN());
933 		break;
934 
935 	case TELOPT_XDISPLOC:
936 		if (my_want_state_is_wont(TELOPT_XDISPLOC))
937 			return;
938 		if (SB_EOF())
939 			return;
940 		if (SB_GET() == TELQUAL_SEND) {
941 			unsigned char temp[50], *dp;
942 			int len, bytes;
943 
944 			if ((dp = env_getvalue((unsigned char *)"DISPLAY")) ==
945 			    NULL) {
946 				/*
947 				 * Something happened, we no longer have a
948 				 * DISPLAY variable.  So, turn off the option.
949 				 */
950 				send_wont(TELOPT_XDISPLOC, 1);
951 				break;
952 			}
953 			bytes = snprintf((char *)temp, sizeof (temp),
954 			    "%c%c%c%c%s%c%c", IAC, SB,
955 			    TELOPT_XDISPLOC, TELQUAL_IS, dp, IAC, SE);
956 			len = strlen((char *)temp+4) + 4; /* temp[3] is 0 ... */
957 
958 			if ((len < NETROOM()) && (bytes < sizeof (temp))) {
959 				ring_supply_data(&netoring, temp, len);
960 				printsub('>', temp+2, len - 2);
961 			}
962 			else
963 				(void) printf(
964 				    "telnet: not enough room in buffer"
965 				    " for display location option reply\n");
966 		}
967 		break;
968 
969 	case TELOPT_AUTHENTICATION: {
970 		if (!autologin)
971 			break;
972 		if (SB_EOF())
973 			return;
974 		switch (SB_GET()) {
975 		case TELQUAL_SEND:
976 			if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
977 				return;
978 			auth_send(subpointer, SB_LEN());
979 			break;
980 		case TELQUAL_REPLY:
981 			if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
982 				return;
983 			auth_reply(subpointer, SB_LEN());
984 			break;
985 		}
986 	}
987 	break;
988 
989 	case TELOPT_ENCRYPT:
990 		if (SB_EOF())
991 			return;
992 		switch (SB_GET()) {
993 		case ENCRYPT_START:
994 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
995 				return;
996 			encrypt_start(subpointer, SB_LEN());
997 			break;
998 		case ENCRYPT_END:
999 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
1000 				return;
1001 			encrypt_end();
1002 			break;
1003 		case ENCRYPT_SUPPORT:
1004 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
1005 				return;
1006 			encrypt_support(subpointer, SB_LEN());
1007 			break;
1008 		case ENCRYPT_REQSTART:
1009 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
1010 				return;
1011 			encrypt_request_start(subpointer, SB_LEN());
1012 			break;
1013 		case ENCRYPT_REQEND:
1014 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
1015 				return;
1016 			/*
1017 			 * We can always send an REQEND so that we cannot
1018 			 * get stuck encrypting.  We should only get this
1019 			 * if we have been able to get in the correct mode
1020 			 * anyhow.
1021 			 */
1022 			encrypt_request_end();
1023 			break;
1024 		case ENCRYPT_IS:
1025 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
1026 				return;
1027 			encrypt_is(subpointer, SB_LEN());
1028 			break;
1029 		case ENCRYPT_REPLY:
1030 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
1031 				return;
1032 			encrypt_reply(subpointer, SB_LEN());
1033 			break;
1034 		case ENCRYPT_ENC_KEYID:
1035 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
1036 				return;
1037 			encrypt_enc_keyid(subpointer, SB_LEN());
1038 			break;
1039 		case ENCRYPT_DEC_KEYID:
1040 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
1041 				return;
1042 			encrypt_dec_keyid(subpointer, SB_LEN());
1043 			break;
1044 		default:
1045 			break;
1046 		}
1047 		break;
1048 	default:
1049 		break;
1050 	}
1051 }
1052 
1053 static unsigned char str_lm[] = { IAC, SB, TELOPT_LINEMODE, 0, 0, IAC, SE };
1054 
1055 static void
1056 lm_will(cmd, len)
1057 	unsigned char *cmd;
1058 	int len;
1059 {
1060 	if (len < 1) {
1061 		/* Should not happen... */
1062 		(void) printf(
1063 		    "telnet: command missing from linemode WILL request\n");
1064 		return;
1065 	}
1066 	switch (cmd[0]) {
1067 	case LM_FORWARDMASK:	/* We shouldn't ever get this... */
1068 	default:
1069 		str_lm[3] = DONT;
1070 		str_lm[4] = cmd[0];
1071 		if (NETROOM() > sizeof (str_lm)) {
1072 			ring_supply_data(&netoring, str_lm, sizeof (str_lm));
1073 			printsub('>', &str_lm[2], sizeof (str_lm)-2);
1074 		}
1075 		else
1076 			(void) printf("telnet: not enough room in buffer for"
1077 			    "reply to linemode WILL request\n");
1078 		break;
1079 	}
1080 }
1081 
1082 static void
1083 lm_wont(cmd, len)
1084 	unsigned char *cmd;
1085 	int len;
1086 {
1087 	if (len < 1) {
1088 		/* Should not happen... */
1089 		(void) printf(
1090 		    "telnet: command missing from linemode WONT request\n");
1091 		return;
1092 	}
1093 	switch (cmd[0]) {
1094 	case LM_FORWARDMASK:	/* We shouldn't ever get this... */
1095 	default:
1096 		/* We are always DONT, so don't respond */
1097 		return;
1098 	}
1099 }
1100 
1101 static void
1102 lm_do(cmd, len)
1103 	unsigned char *cmd;
1104 	int len;
1105 {
1106 	if (len < 1) {
1107 		/* Should not happen... */
1108 		(void) printf(
1109 		    "telnet: command missing from linemode DO request\n");
1110 		return;
1111 	}
1112 	switch (cmd[0]) {
1113 	case LM_FORWARDMASK:
1114 	default:
1115 		str_lm[3] = WONT;
1116 		str_lm[4] = cmd[0];
1117 		if (NETROOM() > sizeof (str_lm)) {
1118 			ring_supply_data(&netoring, str_lm, sizeof (str_lm));
1119 			printsub('>', &str_lm[2], sizeof (str_lm)-2);
1120 		}
1121 		else
1122 			(void) printf("telnet: not enough room in buffer for"
1123 			    "reply to linemode DO request\n");
1124 		break;
1125 	}
1126 }
1127 
1128 static void
1129 lm_dont(cmd, len)
1130 	unsigned char *cmd;
1131 	int len;
1132 {
1133 	if (len < 1) {
1134 		/* Should not happen... */
1135 		(void) printf(
1136 		    "telnet: command missing from linemode DONT request\n");
1137 		return;
1138 	}
1139 	switch (cmd[0]) {
1140 	case LM_FORWARDMASK:
1141 	default:
1142 		/* we are always WONT, so don't respond */
1143 		break;
1144 	}
1145 }
1146 
1147 static unsigned char str_lm_mode[] = {
1148 	IAC, SB, TELOPT_LINEMODE, LM_MODE, 0, IAC, SE
1149 };
1150 
1151 	void
1152 lm_mode(cmd, len, init)
1153 	unsigned char *cmd;
1154 	int len, init;
1155 {
1156 	if (len != 1)
1157 		return;
1158 	if ((linemode&MODE_MASK&~MODE_ACK) == *cmd)
1159 		return;
1160 	linemode = *cmd&(MODE_MASK&~MODE_ACK);
1161 	str_lm_mode[4] = linemode;
1162 	if (!init)
1163 		str_lm_mode[4] |= MODE_ACK;
1164 	if (NETROOM() > sizeof (str_lm_mode)) {
1165 		ring_supply_data(&netoring, str_lm_mode, sizeof (str_lm_mode));
1166 		printsub('>', &str_lm_mode[2], sizeof (str_lm_mode)-2);
1167 	}
1168 	else
1169 		(void) printf("telnet: not enough room in buffer for"
1170 		    "reply to linemode request\n");
1171 	setconnmode(0);	/* set changed mode */
1172 }
1173 
1174 
1175 
1176 /*
1177  * slc()
1178  * Handle special character suboption of LINEMODE.
1179  */
1180 
1181 static struct spc {
1182 	cc_t val;
1183 	cc_t *valp;
1184 	char flags;	/* Current flags & level */
1185 	char mylevel;	/* Maximum level & flags */
1186 } spc_data[NSLC+1];
1187 
1188 #define	SLC_IMPORT	0
1189 #define	SLC_EXPORT	1
1190 #define	SLC_RVALUE	2
1191 static int slc_mode = SLC_EXPORT;
1192 
1193 static void
1194 slc_init()
1195 {
1196 	register struct spc *spcp;
1197 
1198 	localchars = 1;
1199 	for (spcp = spc_data; spcp < &spc_data[NSLC+1]; spcp++) {
1200 		spcp->val = 0;
1201 		spcp->valp = 0;
1202 		spcp->flags = spcp->mylevel = SLC_NOSUPPORT;
1203 	}
1204 
1205 #define	initfunc(func, flags) { \
1206 				spcp = &spc_data[func]; \
1207 				if (spcp->valp = tcval(func)) { \
1208 				    spcp->val = *spcp->valp; \
1209 				    spcp->mylevel = SLC_VARIABLE|(flags);\
1210 				} else { \
1211 				    spcp->val = 0; \
1212 				    spcp->mylevel = SLC_DEFAULT; \
1213 				} \
1214 			    }
1215 
1216 	initfunc(SLC_SYNCH, 0);
1217 	/* No BRK */
1218 	initfunc(SLC_AO, 0);
1219 	initfunc(SLC_AYT, 0);
1220 	/* No EOR */
1221 	initfunc(SLC_ABORT, SLC_FLUSHIN|SLC_FLUSHOUT);
1222 	initfunc(SLC_EOF, 0);
1223 	initfunc(SLC_SUSP, SLC_FLUSHIN);
1224 	initfunc(SLC_EC, 0);
1225 	initfunc(SLC_EL, 0);
1226 	initfunc(SLC_EW, 0);
1227 	initfunc(SLC_RP, 0);
1228 	initfunc(SLC_LNEXT, 0);
1229 	initfunc(SLC_XON, 0);
1230 	initfunc(SLC_XOFF, 0);
1231 	initfunc(SLC_FORW1, 0);
1232 #ifdef	USE_TERMIO
1233 	initfunc(SLC_FORW2, 0);
1234 	/* No FORW2 */
1235 #endif
1236 
1237 	initfunc(SLC_IP, SLC_FLUSHIN|SLC_FLUSHOUT);
1238 #undef	initfunc
1239 
1240 	if (slc_mode == SLC_EXPORT)
1241 		slc_export();
1242 	else
1243 		slc_import(1);
1244 
1245 }
1246 
1247 void
1248 slcstate()
1249 {
1250 	(void) printf("Special characters are %s values\n",
1251 		slc_mode == SLC_IMPORT ? "remote default" :
1252 		slc_mode == SLC_EXPORT ? "local" :
1253 					"remote");
1254 }
1255 
1256 void
1257 slc_mode_export()
1258 {
1259 	slc_mode = SLC_EXPORT;
1260 	if (my_state_is_will(TELOPT_LINEMODE))
1261 		slc_export();
1262 }
1263 
1264 void
1265 slc_mode_import(def)
1266     int def;
1267 {
1268     slc_mode = def ? SLC_IMPORT : SLC_RVALUE;
1269     if (my_state_is_will(TELOPT_LINEMODE))
1270 	slc_import(def);
1271 }
1272 
1273 static unsigned char slc_import_val[] = {
1274 	IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_VARIABLE, 0, IAC, SE
1275 };
1276 static unsigned char slc_import_def[] = {
1277 	IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_DEFAULT, 0, IAC, SE
1278 };
1279 
1280 static void
1281 slc_import(def)
1282 	int def;
1283 {
1284 	if (NETROOM() > sizeof (slc_import_val)) {
1285 		if (def) {
1286 			ring_supply_data(&netoring, slc_import_def,
1287 			    sizeof (slc_import_def));
1288 			printsub('>', &slc_import_def[2],
1289 			    sizeof (slc_import_def)-2);
1290 		} else {
1291 			ring_supply_data(&netoring, slc_import_val,
1292 			    sizeof (slc_import_val));
1293 			printsub('>', &slc_import_val[2],
1294 			    sizeof (slc_import_val)-2);
1295 		}
1296 	}
1297 	else
1298 		(void) printf(
1299 		    "telnet: not enough room in buffer for slc import"
1300 		    " request\n");
1301 }
1302 
1303 static uchar_t *slc_reply = NULL;
1304 static uchar_t *slc_replyp = NULL;
1305 /*
1306  * The SLC reply consists of: IAC, SB, TELOPT_LINEMODE, LM_SLC,
1307  * SLC triplets[], IAC, SE. i.e. it has a 'wrapper' of 6 control characters.
1308  */
1309 #define	SLC_WRAPPER_SIZE 6
1310 
1311 static void
1312 slc_export()
1313 {
1314 	register struct spc *spcp;
1315 
1316 	TerminalDefaultChars();
1317 
1318 	slc_start_reply(NSLC * 3);	/* 3 bytes needed per triplet */
1319 	for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1320 		if (spcp->mylevel != SLC_NOSUPPORT) {
1321 			if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1322 				spcp->flags = SLC_NOSUPPORT;
1323 			else
1324 				spcp->flags = spcp->mylevel;
1325 			if (spcp->valp)
1326 				spcp->val = *spcp->valp;
1327 			slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1328 		}
1329 	}
1330 	slc_end_reply();
1331 	(void) slc_update();
1332 	setconnmode(1);	/* Make sure the character values are set */
1333 }
1334 
1335 static void
1336 slc(cp, len)
1337 	register unsigned char *cp;
1338 	int len;
1339 {
1340 	register struct spc *spcp;
1341 	register int func, level;
1342 
1343 	slc_start_reply(len);
1344 
1345 	for (; len >= 3; len -= 3, cp += 3) {
1346 
1347 		func = cp[SLC_FUNC];
1348 
1349 		if (func == 0) {
1350 			/*
1351 			 * Client side: always ignore 0 function.
1352 			 */
1353 			continue;
1354 		}
1355 		if (func > NSLC) {
1356 			if ((cp[SLC_FLAGS] & SLC_LEVELBITS) != SLC_NOSUPPORT)
1357 				slc_add_reply(func, SLC_NOSUPPORT, 0);
1358 			continue;
1359 		}
1360 
1361 		spcp = &spc_data[func];
1362 
1363 		level = cp[SLC_FLAGS]&(SLC_LEVELBITS|SLC_ACK);
1364 
1365 		if ((cp[SLC_VALUE] == (unsigned char)spcp->val) &&
1366 		    ((level&SLC_LEVELBITS) == (spcp->flags&SLC_LEVELBITS))) {
1367 			continue;
1368 		}
1369 
1370 		if (level == (SLC_DEFAULT|SLC_ACK)) {
1371 			/*
1372 			 * This is an error condition, the SLC_ACK
1373 			 * bit should never be set for the SLC_DEFAULT
1374 			 * level.  Our best guess to recover is to
1375 			 * ignore the SLC_ACK bit.
1376 			 */
1377 			cp[SLC_FLAGS] &= ~SLC_ACK;
1378 		}
1379 
1380 		if (level == ((spcp->flags&SLC_LEVELBITS)|SLC_ACK)) {
1381 			spcp->val = (cc_t)cp[SLC_VALUE];
1382 			spcp->flags = cp[SLC_FLAGS];	/* include SLC_ACK */
1383 			continue;
1384 		}
1385 
1386 		level &= ~SLC_ACK;
1387 
1388 		if (level <= (spcp->mylevel&SLC_LEVELBITS)) {
1389 			spcp->flags = cp[SLC_FLAGS]|SLC_ACK;
1390 			spcp->val = (cc_t)cp[SLC_VALUE];
1391 		}
1392 		if (level == SLC_DEFAULT) {
1393 			if ((spcp->mylevel&SLC_LEVELBITS) != SLC_DEFAULT)
1394 				spcp->flags = spcp->mylevel;
1395 			else
1396 				spcp->flags = SLC_NOSUPPORT;
1397 		}
1398 		slc_add_reply(func, spcp->flags, spcp->val);
1399 	}
1400 	slc_end_reply();
1401 	if (slc_update())
1402 		setconnmode(1);	/* set the  new character values */
1403 }
1404 
1405 void
1406 slc_check()
1407 {
1408 	register struct spc *spcp;
1409 
1410 	slc_start_reply(NSLC * 3);	/* 3 bytes needed per triplet */
1411 	for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1412 		if (spcp->valp && spcp->val != *spcp->valp) {
1413 			spcp->val = *spcp->valp;
1414 			if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1415 				spcp->flags = SLC_NOSUPPORT;
1416 			else
1417 				spcp->flags = spcp->mylevel;
1418 			slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1419 		}
1420 	}
1421 	slc_end_reply();
1422 	setconnmode(1);
1423 }
1424 
1425 static void
1426 slc_start_reply(size_t len)
1427 {
1428 	/*
1429 	 * SLC triplets may contain escaped characters, allow for
1430 	 * worst case by allocating 2 bytes for every character.
1431 	 */
1432 	slc_reply = realloc(slc_reply, (len * 2) + SLC_WRAPPER_SIZE);
1433 	if (slc_reply == NULL) {
1434 		fprintf(stderr, "telnet: error allocating SLC reply memory\n");
1435 		return;
1436 	}
1437 	slc_replyp = slc_reply;
1438 	*slc_replyp++ = IAC;
1439 	*slc_replyp++ = SB;
1440 	*slc_replyp++ = TELOPT_LINEMODE;
1441 	*slc_replyp++ = LM_SLC;
1442 }
1443 
1444 static void
1445 slc_add_reply(unsigned char func, unsigned char flags, cc_t value)
1446 {
1447 	if ((*slc_replyp++ = func) == IAC)
1448 		*slc_replyp++ = IAC;
1449 	if ((*slc_replyp++ = flags) == IAC)
1450 		*slc_replyp++ = IAC;
1451 	if ((*slc_replyp++ = (unsigned char)value) == IAC)
1452 		*slc_replyp++ = IAC;
1453 }
1454 
1455 static void
1456 slc_end_reply()
1457 {
1458 	register int len;
1459 
1460 	*slc_replyp++ = IAC;
1461 	*slc_replyp++ = SE;
1462 	len = slc_replyp - slc_reply;
1463 	if (len <= SLC_WRAPPER_SIZE)
1464 		return;
1465 	if (NETROOM() > len) {
1466 		ring_supply_data(&netoring, slc_reply, slc_replyp - slc_reply);
1467 		printsub('>', &slc_reply[2], slc_replyp - slc_reply - 2);
1468 	}
1469 	else
1470 		(void) printf("telnet: not enough room in buffer for slc end "
1471 		    "reply\n");
1472 }
1473 
1474 static int
1475 slc_update()
1476 {
1477 	register struct spc *spcp;
1478 	int need_update = 0;
1479 
1480 	for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1481 		if (!(spcp->flags&SLC_ACK))
1482 			continue;
1483 		spcp->flags &= ~SLC_ACK;
1484 		if (spcp->valp && (*spcp->valp != spcp->val)) {
1485 			*spcp->valp = spcp->val;
1486 			need_update = 1;
1487 		}
1488 	}
1489 	return (need_update);
1490 }
1491 
1492 #ifdef	OLD_ENVIRON
1493 #ifdef	ENV_HACK
1494 /*
1495  * Earlier version of telnet/telnetd from the BSD code had
1496  * the definitions of VALUE and VAR reversed.  To ensure
1497  * maximum interoperability, we assume that the server is
1498  * an older BSD server, until proven otherwise.  The newer
1499  * BSD servers should be able to handle either definition,
1500  * so it is better to use the wrong values if we don't
1501  * know what type of server it is.
1502  */
1503 int env_auto = 1;
1504 int old_env_var = OLD_ENV_VAR;
1505 int old_env_value = OLD_ENV_VALUE;
1506 #else
1507 #define	old_env_var	OLD_ENV_VAR
1508 #define	old_env_value	OLD_ENV_VALUE
1509 #endif
1510 #endif
1511 
1512 static void
1513 env_opt(buf, len)
1514 	register unsigned char *buf;
1515 	register int len;
1516 {
1517 	register unsigned char *ep = 0, *epc = 0;
1518 	register int i;
1519 
1520 	switch (buf[0]&0xff) {
1521 	case TELQUAL_SEND:
1522 		env_opt_start();
1523 		if (len == 1) {
1524 			env_opt_add(NULL);
1525 		} else for (i = 1; i < len; i++) {
1526 			switch (buf[i]&0xff) {
1527 #ifdef	OLD_ENVIRON
1528 			case OLD_ENV_VAR:
1529 #ifdef	ENV_HACK
1530 				if (telopt_environ == TELOPT_OLD_ENVIRON &&
1531 				    env_auto) {
1532 					/* Server has the same definitions */
1533 					old_env_var = OLD_ENV_VAR;
1534 					old_env_value = OLD_ENV_VALUE;
1535 				}
1536 				/* FALLTHROUGH */
1537 #endif
1538 			case OLD_ENV_VALUE:
1539 				/*
1540 				 * Although OLD_ENV_VALUE is not legal, we will
1541 				 * still recognize it, just in case it is an
1542 				 * old server that has VAR & VALUE mixed up...
1543 				 */
1544 				/* FALLTHROUGH */
1545 #else
1546 			case NEW_ENV_VAR:
1547 #endif
1548 			case ENV_USERVAR:
1549 				if (ep) {
1550 					*epc = 0;
1551 					env_opt_add(ep);
1552 				}
1553 				ep = epc = &buf[i+1];
1554 				break;
1555 			case ENV_ESC:
1556 				i++;
1557 				/*FALLTHROUGH*/
1558 			default:
1559 				if (epc)
1560 					*epc++ = buf[i];
1561 				break;
1562 			}
1563 		}
1564 		if (ep) {
1565 			*epc = 0;
1566 			env_opt_add(ep);
1567 		}
1568 		env_opt_end(1);
1569 		break;
1570 
1571 	case TELQUAL_IS:
1572 	case TELQUAL_INFO:
1573 		/* Ignore for now.  We shouldn't get it anyway. */
1574 		break;
1575 
1576 	default:
1577 		break;
1578 	}
1579 }
1580 
1581 static unsigned char *opt_reply;
1582 static unsigned char *opt_replyp;
1583 static unsigned char *opt_replyend;
1584 #define	OPT_REPLY_INITIAL_SIZE	256
1585 /*
1586  * The opt reply consists of: IAC, SB, telopt_environ, TELQUAL_IS,
1587  * value, IAC, SE. i.e. it has a 'wrapper' of 6 control characters.
1588  */
1589 #define	OPT_WRAPPER_SIZE 6
1590 
1591 static void
1592 env_opt_start()
1593 {
1594 	opt_reply = realloc(opt_reply, OPT_REPLY_INITIAL_SIZE);
1595 	if (opt_reply == NULL) {
1596 		(void) printf(
1597 		    "telnet: error allocating environment option memory\n");
1598 		opt_reply = opt_replyp = opt_replyend = NULL;
1599 		return;
1600 	}
1601 	opt_replyp = opt_reply;
1602 	opt_replyend = opt_reply + OPT_REPLY_INITIAL_SIZE;
1603 	*opt_replyp++ = IAC;
1604 	*opt_replyp++ = SB;
1605 	*opt_replyp++ = telopt_environ;
1606 	*opt_replyp++ = TELQUAL_IS;
1607 }
1608 
1609 	void
1610 env_opt_start_info()
1611 {
1612 	env_opt_start();
1613 	if (opt_replyp)
1614 	    opt_replyp[-1] = TELQUAL_INFO;
1615 }
1616 
1617 	void
1618 env_opt_add(ep)
1619 	register unsigned char *ep;
1620 {
1621 	register unsigned char *vp, c;
1622 	int opt_reply_size;
1623 	int opt_reply_used;
1624 
1625 	if (opt_reply == NULL)		/* XXX */
1626 		return;			/* XXX */
1627 
1628 	if (ep == NULL || *ep == '\0') {
1629 		/* Send user defined variables first. */
1630 		(void) env_default(1, 0);
1631 		while (ep = env_default(0, 0))
1632 			env_opt_add(ep);
1633 
1634 		/* Now add the list of well know variables.  */
1635 		(void) env_default(1, 1);
1636 		while (ep = env_default(0, 1))
1637 			env_opt_add(ep);
1638 		return;
1639 	}
1640 	vp = env_getvalue(ep);
1641 
1642 	/*
1643 	 * Calculate space required for opt_reply and allocate more if required.
1644 	 * Assume worst case that every character is escaped, so needs 2 bytes.
1645 	 */
1646 	opt_reply_used = opt_replyp - opt_reply;	/* existing contents */
1647 	opt_reply_size = opt_reply_used + OPT_WRAPPER_SIZE +
1648 	    (2 * (strlen((char *)ep))) +
1649 	    (vp == NULL ? 0 : (2 * strlen((char *)vp)));
1650 
1651 	if (opt_reply_size > (opt_replyend - opt_reply)) {
1652 		opt_reply = realloc(opt_reply, opt_reply_size);
1653 		if (opt_reply == NULL) {
1654 			(void) printf(
1655 			    "telnet: can't allocate environment option "
1656 			    "reply\n");
1657 			opt_reply = opt_replyp = opt_replyend = NULL;
1658 			return;
1659 		}
1660 		opt_replyp = opt_reply + opt_reply_used;
1661 		opt_replyend = opt_reply + opt_reply_size;
1662 	}
1663 
1664 	if (opt_welldefined((char *)ep))
1665 #ifdef	OLD_ENVIRON
1666 		if (telopt_environ == TELOPT_OLD_ENVIRON)
1667 			*opt_replyp++ = old_env_var;
1668 		else
1669 #endif
1670 			*opt_replyp++ = NEW_ENV_VAR;
1671 	else
1672 		*opt_replyp++ = ENV_USERVAR;
1673 	for (;;) {
1674 		while ((c = *ep++) != '\0') {
1675 			switch (c&0xff) {
1676 			case IAC:
1677 				*opt_replyp++ = IAC;
1678 				break;
1679 			case NEW_ENV_VAR:
1680 			case NEW_ENV_VALUE:
1681 			case ENV_ESC:
1682 			case ENV_USERVAR:
1683 				*opt_replyp++ = ENV_ESC;
1684 				break;
1685 			}
1686 			*opt_replyp++ = c;
1687 		}
1688 		if ((ep = vp) != NULL) {
1689 #ifdef	OLD_ENVIRON
1690 			if (telopt_environ == TELOPT_OLD_ENVIRON)
1691 				*opt_replyp++ = old_env_value;
1692 			else
1693 #endif
1694 				*opt_replyp++ = NEW_ENV_VALUE;
1695 			vp = NULL;
1696 		} else
1697 			break;
1698 	}
1699 }
1700 
1701 	int
1702 opt_welldefined(ep)
1703 	char *ep;
1704 {
1705 	if ((strcmp(ep, "USER") == 0) ||
1706 	    (strcmp(ep, "DISPLAY") == 0) ||
1707 	    (strcmp(ep, "PRINTER") == 0) ||
1708 	    (strcmp(ep, "SYSTEMTYPE") == 0) ||
1709 	    (strcmp(ep, "JOB") == 0) ||
1710 	    (strcmp(ep, "ACCT") == 0))
1711 		return (1);
1712 	return (0);
1713 }
1714 	void
1715 env_opt_end(emptyok)
1716 	register int emptyok;
1717 {
1718 	register int len;
1719 
1720 	len = opt_replyp - opt_reply + 2;
1721 	if (emptyok || len > OPT_WRAPPER_SIZE) {
1722 		*opt_replyp++ = IAC;
1723 		*opt_replyp++ = SE;
1724 		if (NETROOM() > len) {
1725 			ring_supply_data(&netoring, opt_reply, len);
1726 			printsub('>', &opt_reply[2], len - 2);
1727 		}
1728 		else
1729 			(void) printf("telnet: not enough room in buffer for "
1730 			    "environment option end reply\n");
1731 	}
1732 	if (opt_reply) {
1733 		free(opt_reply);
1734 		opt_reply = opt_replyp = opt_replyend = NULL;
1735 	}
1736 }
1737 
1738 
1739 
1740 int
1741 telrcv()
1742 {
1743 	register int c;
1744 	register int scc;
1745 	register unsigned char *sbp;
1746 	int count;
1747 	int returnValue = 0;
1748 	int min_room = 0;
1749 
1750 	scc = 0;
1751 	count = 0;
1752 	while (--min_room > 2 || (min_room = TTYROOM()) > 2) {
1753 		if (scc == 0) {
1754 			if (count) {
1755 				ring_consumed(&netiring, count);
1756 				returnValue = 1;
1757 				count = 0;
1758 			}
1759 			sbp = netiring.consume;
1760 			scc = ring_full_consecutive(&netiring);
1761 			if (scc == 0) {
1762 				/* No more data coming in */
1763 				break;
1764 			}
1765 		}
1766 
1767 		c = *sbp++ & 0xff, scc--; count++;
1768 
1769 		if (decrypt_input)
1770 			c = (*decrypt_input)(c);
1771 
1772 		switch (telrcv_state) {
1773 
1774 		case TS_CR:
1775 			telrcv_state = TS_DATA;
1776 			if (c == '\0') {
1777 				break;	/* Ignore \0 after CR */
1778 			} else if ((c == '\n') &&
1779 			    my_want_state_is_dont(TELOPT_ECHO) && !crmod) {
1780 				TTYADD(c);
1781 				break;
1782 			}
1783 			/* FALLTHROUGH */
1784 
1785 		case TS_DATA:
1786 			if (c == IAC) {
1787 				telrcv_state = TS_IAC;
1788 				break;
1789 			}
1790 			/*
1791 			 * The 'crmod' hack (see following) is needed
1792 			 * since we can't * set CRMOD on output only.
1793 			 * Machines like MULTICS like to send \r without
1794 			 * \n; since we must turn off CRMOD to get proper
1795 			 * input, the mapping is done here (sigh).
1796 			 */
1797 			if ((c == '\r') &&
1798 			    my_want_state_is_dont(TELOPT_BINARY)) {
1799 				if (scc > 0) {
1800 					c = *sbp&0xff;
1801 
1802 					if (decrypt_input)
1803 						c = (*decrypt_input)(c);
1804 
1805 					if (c == 0) {
1806 						sbp++, scc--; count++;
1807 						/* a "true" CR */
1808 						TTYADD('\r');
1809 					} else if (my_want_state_is_dont(
1810 					    TELOPT_ECHO) && (c == '\n')) {
1811 						sbp++, scc--; count++;
1812 						TTYADD('\n');
1813 					} else {
1814 
1815 						if (decrypt_input)
1816 							(*decrypt_input)(-1);
1817 
1818 						TTYADD('\r');
1819 						if (crmod) {
1820 							TTYADD('\n');
1821 						}
1822 					}
1823 				} else {
1824 					telrcv_state = TS_CR;
1825 					TTYADD('\r');
1826 					if (crmod) {
1827 						TTYADD('\n');
1828 					}
1829 				}
1830 			} else {
1831 				TTYADD(c);
1832 			}
1833 			continue;
1834 
1835 		case TS_IAC:
1836 process_iac:
1837 			switch (c) {
1838 
1839 			case WILL:
1840 				telrcv_state = TS_WILL;
1841 				continue;
1842 
1843 			case WONT:
1844 				telrcv_state = TS_WONT;
1845 				continue;
1846 
1847 			case DO:
1848 				telrcv_state = TS_DO;
1849 				continue;
1850 
1851 			case DONT:
1852 				telrcv_state = TS_DONT;
1853 				continue;
1854 
1855 			case DM:
1856 				/*
1857 				 * We may have missed an urgent notification,
1858 				 * so make sure we flush whatever is in the
1859 				 * buffer currently.
1860 				 */
1861 				printoption("RCVD", IAC, DM);
1862 				SYNCHing = 1;
1863 				if (ttyflush(1) == -2) {
1864 					/* This will not return. */
1865 					fatal_tty_error("write");
1866 				}
1867 				SYNCHing = stilloob();
1868 				settimer(gotDM);
1869 				break;
1870 
1871 			case SB:
1872 				SB_CLEAR();
1873 				telrcv_state = TS_SB;
1874 				continue;
1875 
1876 			case IAC:
1877 				TTYADD(IAC);
1878 				break;
1879 
1880 			case NOP:
1881 			case GA:
1882 			default:
1883 				printoption("RCVD", IAC, c);
1884 				break;
1885 			}
1886 			telrcv_state = TS_DATA;
1887 			continue;
1888 
1889 		case TS_WILL:
1890 			printoption("RCVD", WILL, c);
1891 			willoption(c);
1892 			telrcv_state = TS_DATA;
1893 			continue;
1894 
1895 		case TS_WONT:
1896 			printoption("RCVD", WONT, c);
1897 			wontoption(c);
1898 			telrcv_state = TS_DATA;
1899 			continue;
1900 
1901 		case TS_DO:
1902 			printoption("RCVD", DO, c);
1903 			dooption(c);
1904 			if (c == TELOPT_NAWS) {
1905 				sendnaws();
1906 			} else if (c == TELOPT_LFLOW) {
1907 				localflow = 1;
1908 				setcommandmode();
1909 				setconnmode(0);
1910 			}
1911 			telrcv_state = TS_DATA;
1912 			continue;
1913 
1914 		case TS_DONT:
1915 			printoption("RCVD", DONT, c);
1916 			dontoption(c);
1917 			flushline = 1;
1918 			setconnmode(0);	/* set new tty mode (maybe) */
1919 			telrcv_state = TS_DATA;
1920 			continue;
1921 
1922 		case TS_SB:
1923 			if (c == IAC) {
1924 				telrcv_state = TS_SE;
1925 			} else {
1926 				SB_ACCUM(c);
1927 			}
1928 			continue;
1929 
1930 		case TS_SE:
1931 			if (c != SE) {
1932 				if (c != IAC) {
1933 			/*
1934 			 * This is an error.  We only expect to get
1935 			 * "IAC IAC" or "IAC SE".  Several things may
1936 			 * have happend.  An IAC was not doubled, the
1937 			 * IAC SE was left off, or another option got
1938 			 * inserted into the suboption are all possibilities.
1939 			 * If we assume that the IAC was not doubled,
1940 			 * and really the IAC SE was left off, we could
1941 			 * get into an infinate loop here.  So, instead,
1942 			 * we terminate the suboption, and process the
1943 			 * partial suboption if we can.
1944 			 */
1945 					SB_ACCUM(IAC);
1946 					SB_ACCUM(c);
1947 					subpointer -= 2;
1948 					SB_TERM();
1949 
1950 					printoption("In SUBOPTION processing, "
1951 					    "RCVD", IAC, c);
1952 					suboption();	/* handle sub-option */
1953 					telrcv_state = TS_IAC;
1954 					goto process_iac;
1955 				}
1956 				SB_ACCUM(c);
1957 				telrcv_state = TS_SB;
1958 			} else {
1959 				SB_ACCUM(IAC);
1960 				SB_ACCUM(SE);
1961 				subpointer -= 2;
1962 				SB_TERM();
1963 				suboption();	/* handle sub-option */
1964 				telrcv_state = TS_DATA;
1965 			}
1966 		}
1967 	}
1968 	if (count)
1969 		ring_consumed(&netiring, count);
1970 	return (returnValue||count);
1971 }
1972 
1973 static int bol = 1, local = 0;
1974 
1975 int
1976 rlogin_susp()
1977 {
1978 	if (local) {
1979 		local = 0;
1980 		bol = 1;
1981 		command(0, "z\n", 2);
1982 		return (1);
1983 	}
1984 	return (0);
1985 }
1986 
1987 static int
1988 telsnd()
1989 {
1990 	int tcc;
1991 	int count;
1992 	int returnValue = 0;
1993 	unsigned char *tbp;
1994 
1995 	tcc = 0;
1996 	count = 0;
1997 	while (NETROOM() > 2) {
1998 		register int sc;
1999 		register int c;
2000 
2001 		if (tcc == 0) {
2002 			if (count) {
2003 				ring_consumed(&ttyiring, count);
2004 				returnValue = 1;
2005 				count = 0;
2006 			}
2007 			tbp = ttyiring.consume;
2008 			tcc = ring_full_consecutive(&ttyiring);
2009 			if (tcc == 0) {
2010 				break;
2011 			}
2012 		}
2013 		c = *tbp++ & 0xff, sc = strip(c), tcc--; count++;
2014 		if (rlogin != _POSIX_VDISABLE) {
2015 			if (bol) {
2016 				bol = 0;
2017 				if (sc == rlogin) {
2018 					local = 1;
2019 					continue;
2020 				}
2021 			} else if (local) {
2022 				local = 0;
2023 				if (sc == '.' || c == termEofChar) {
2024 					bol = 1;
2025 					command(0, "close\n", 6);
2026 					continue;
2027 				}
2028 				if (sc == termSuspChar) {
2029 					bol = 1;
2030 					command(0, "z\n", 2);
2031 					continue;
2032 				}
2033 				if (sc == escape) {
2034 					command(0, (char *)tbp, tcc);
2035 					bol = 1;
2036 					count += tcc;
2037 					tcc = 0;
2038 					flushline = 1;
2039 					break;
2040 				}
2041 				if (sc != rlogin) {
2042 					++tcc;
2043 					--tbp;
2044 					--count;
2045 					c = sc = rlogin;
2046 				}
2047 			}
2048 			if ((sc == '\n') || (sc == '\r'))
2049 				bol = 1;
2050 		} else if (sc == escape && escape_valid) {
2051 			/*
2052 			 * Double escape is a pass through of a single
2053 			 * escape character.
2054 			 */
2055 			if (tcc && strip(*tbp) == escape) {
2056 				tbp++;
2057 				tcc--;
2058 				count++;
2059 				bol = 0;
2060 			} else {
2061 				command(0, (char *)tbp, tcc);
2062 				bol = 1;
2063 				count += tcc;
2064 				tcc = 0;
2065 				flushline = 1;
2066 				break;
2067 			}
2068 		} else
2069 			bol = 0;
2070 #ifdef	KLUDGELINEMODE
2071 		if (kludgelinemode && (globalmode&MODE_EDIT) && (sc == echoc)) {
2072 			if (tcc > 0 && strip(*tbp) == echoc) {
2073 				tcc--; tbp++; count++;
2074 			} else {
2075 				dontlecho = !dontlecho;
2076 				settimer(echotoggle);
2077 				setconnmode(0);
2078 				flushline = 1;
2079 				break;
2080 			}
2081 		}
2082 #endif
2083 		if (MODE_LOCAL_CHARS(globalmode)) {
2084 			if (TerminalSpecialChars(sc) == 0) {
2085 				bol = 1;
2086 				break;
2087 			}
2088 		}
2089 		if (my_want_state_is_wont(TELOPT_BINARY)) {
2090 			switch (c) {
2091 			case '\n':
2092 				/*
2093 				 * If we are in CRMOD mode (\r ==> \n)
2094 				 * on our local machine, then probably
2095 				 * a newline (unix) is CRLF (TELNET).
2096 				 */
2097 				if (MODE_LOCAL_CHARS(globalmode)) {
2098 					NETADD('\r');
2099 				}
2100 				NETADD('\n');
2101 				bol = flushline = 1;
2102 				break;
2103 			case '\r':
2104 				if (!crlf) {
2105 					NET2ADD('\r', '\0');
2106 				} else {
2107 					NET2ADD('\r', '\n');
2108 				}
2109 				bol = flushline = 1;
2110 				break;
2111 			case IAC:
2112 				NET2ADD(IAC, IAC);
2113 				break;
2114 			default:
2115 				NETADD(c);
2116 				break;
2117 			}
2118 		} else if (c == IAC) {
2119 			NET2ADD(IAC, IAC);
2120 		} else {
2121 			NETADD(c);
2122 		}
2123 	}
2124 	if (count)
2125 		ring_consumed(&ttyiring, count);
2126 	return (returnValue||count);	/* Non-zero if we did anything */
2127 }
2128 
2129 /*
2130  * Scheduler()
2131  *
2132  * Try to do something.
2133  *
2134  * If we do something useful, return 1; else return 0.
2135  *
2136  */
2137 
2138 
2139 int
2140 Scheduler(block)
2141 	int	block;		/* should we block in the select ? */
2142 {
2143 	/*
2144 	 * One wants to be a bit careful about setting returnValue
2145 	 * to one, since a one implies we did some useful work,
2146 	 * and therefore probably won't be called to block next
2147 	 * time (TN3270 mode only).
2148 	 */
2149 	int returnValue;
2150 	int netin, netout, netex, ttyin, ttyout;
2151 
2152 	/* Decide which rings should be processed */
2153 
2154 	netout = ring_full_count(&netoring) &&
2155 	    (flushline ||
2156 	    (my_want_state_is_wont(TELOPT_LINEMODE)
2157 #ifdef	KLUDGELINEMODE
2158 	    /* X */ && (!kludgelinemode || my_want_state_is_do(TELOPT_SGA))
2159 #endif
2160 	    /* XXX */) ||
2161 	    my_want_state_is_will(TELOPT_BINARY));
2162 	ttyout = ring_full_count(&ttyoring);
2163 
2164 	ttyin = (ring_empty_count(&ttyiring) && !eof_pending);
2165 
2166 	netin = !ISend && ring_empty_count(&netiring);
2167 
2168 	netex = !SYNCHing;
2169 
2170 	if (scheduler_lockout_tty) {
2171 		ttyin = ttyout = 0;
2172 	}
2173 
2174 	/* Call to system code to process rings */
2175 
2176 	returnValue = process_rings(netin, netout, netex, ttyin, ttyout,
2177 	    !block);
2178 
2179 	/* Now, look at the input rings, looking for work to do. */
2180 
2181 	if (ring_full_count(&ttyiring)) {
2182 		returnValue |= telsnd();
2183 	} else {
2184 		/*
2185 		 * If ttyiring is empty, check to see if there is a real EOF
2186 		 * pending.  If so, we can maybe do the EOF write now.
2187 		 */
2188 		if (eof_pending) {
2189 			eof_pending = 0;
2190 			sendeof();
2191 		}
2192 	}
2193 
2194 	if (ring_full_count(&netiring)) {
2195 		returnValue |= telrcv();
2196 	}
2197 	return (returnValue);
2198 }
2199 
2200 /*
2201  * Select from tty and network...
2202  */
2203 void
2204 telnet(user)
2205 	char *user;
2206 {
2207 	sys_telnet_init();
2208 
2209 	{
2210 		static char local_host[MAXHOSTNAMELEN] = { 0 };
2211 
2212 		if (!local_host[0]) {
2213 			(void) gethostname(local_host, sizeof (local_host));
2214 			local_host[sizeof (local_host)-1] = 0;
2215 		}
2216 		auth_encrypt_init(local_host, hostname, "TELNET");
2217 		auth_encrypt_user(user);
2218 	}
2219 
2220 	if (autologin)
2221 		send_will(TELOPT_AUTHENTICATION, 1);
2222 
2223 	if (telnetport || wantencryption) {
2224 		send_do(TELOPT_ENCRYPT, 1);
2225 		send_will(TELOPT_ENCRYPT, 1);
2226 	}
2227 
2228 	if (telnetport) {
2229 		if (!reqd_linemode)
2230 		    send_do(TELOPT_SGA, 1);
2231 		send_will(TELOPT_TTYPE, 1);
2232 		send_will(TELOPT_NAWS, 1);
2233 		send_will(TELOPT_TSPEED, 1);
2234 		send_will(TELOPT_LFLOW, 1);
2235 		if (!reqd_linemode)
2236 		    send_will(TELOPT_LINEMODE, 1);
2237 		send_will(TELOPT_NEW_ENVIRON, 1);
2238 		send_do(TELOPT_STATUS, 1);
2239 		if (env_getvalue((unsigned char *)"DISPLAY"))
2240 			send_will(TELOPT_XDISPLOC, 1);
2241 		if (eight)
2242 			tel_enter_binary(eight);
2243 	}
2244 
2245 	/*
2246 	 * Note: we assume a tie to the authentication option here.  This
2247 	 * is necessary so that authentication fails, we don't spin
2248 	 * forever.
2249 	 */
2250 	if (wantencryption) {
2251 		boolean_t printed_encrypt = B_FALSE;
2252 		extern boolean_t auth_has_failed;
2253 		time_t timeout = time(0) + 60;
2254 
2255 		send_do(TELOPT_ENCRYPT, 1);
2256 		send_will(TELOPT_ENCRYPT, 1);
2257 		for (;;) {
2258 		    if (my_want_state_is_wont(TELOPT_AUTHENTICATION)) {
2259 			(void) printf(gettext(
2260 				"\nServer refused to negotiate "
2261 				"authentication, which is required\n"
2262 				"for encryption.  Good-bye.\n\r"));
2263 			Exit(EXIT_FAILURE);
2264 		    }
2265 		    if (auth_has_failed) {
2266 			(void) printf(gettext(
2267 			    "\nAuthentication negotation has failed, "
2268 			    "which is required for\n"
2269 			    "encryption.  Good-bye.\n\r"));
2270 			Exit(EXIT_FAILURE);
2271 		    }
2272 		    if (my_want_state_is_dont(TELOPT_ENCRYPT) ||
2273 			my_want_state_is_wont(TELOPT_ENCRYPT)) {
2274 			    (void) printf(gettext(
2275 				"\nServer refused to negotiate encryption.  "
2276 				"Good-bye.\n\r"));
2277 			    Exit(EXIT_FAILURE);
2278 		    }
2279 		    if (encrypt_is_encrypting())
2280 			break;
2281 
2282 		    if (time(0) > timeout) {
2283 			(void) printf(gettext(
2284 				"\nEncryption could not be enabled.  "
2285 				"Good-bye.\n\r"));
2286 			Exit(EXIT_FAILURE);
2287 		    }
2288 		    if (printed_encrypt == B_FALSE) {
2289 			printed_encrypt = B_TRUE;
2290 			(void) printf(gettext(
2291 			    "Waiting for encryption to be negotiated...\n"));
2292 			/*
2293 			 * Turn on MODE_TRAPSIG and then turn off localchars
2294 			 * so that ^C will cause telnet to exit.
2295 			 */
2296 			TerminalNewMode(getconnmode()|MODE_TRAPSIG);
2297 			intr_waiting = 1;
2298 		    }
2299 		    if (intr_happened) {
2300 			(void) printf(gettext(
2301 			    "\nUser requested an interrupt.  Good-bye.\n\r"));
2302 			Exit(EXIT_FAILURE);
2303 		    }
2304 		    telnet_spin();
2305 		}
2306 		if (printed_encrypt) {
2307 			(void) printf(gettext("done.\n"));
2308 			intr_waiting = 0;
2309 			setconnmode(0);
2310 		}
2311 	}
2312 
2313 	for (;;) {
2314 		int schedValue;
2315 
2316 		while ((schedValue = Scheduler(0)) != 0) {
2317 			if (schedValue == -1) {
2318 				setcommandmode();
2319 				return;
2320 			}
2321 		}
2322 
2323 		if (Scheduler(1) == -1) {
2324 			setcommandmode();
2325 			return;
2326 		}
2327 	}
2328 }
2329 
2330 #if	0	/* XXX - this not being in is a bug */
2331 /*
2332  * nextitem()
2333  *
2334  *	Return the address of the next "item" in the TELNET data
2335  * stream.  This will be the address of the next character if
2336  * the current address is a user data character, or it will
2337  * be the address of the character following the TELNET command
2338  * if the current address is a TELNET IAC ("I Am a Command")
2339  * character.
2340  */
2341 
2342 static char *
2343 nextitem(current)
2344 	char *current;
2345 {
2346 	if ((*current&0xff) != IAC) {
2347 		return (current+1);
2348 	}
2349 	switch (*(current+1)&0xff) {
2350 	case DO:
2351 	case DONT:
2352 	case WILL:
2353 	case WONT:
2354 		return (current+3);
2355 	case SB:		/* loop forever looking for the SE */
2356 	{
2357 		register char *look = current+2;
2358 
2359 		for (;;) {
2360 			if ((*look++&0xff) == IAC) {
2361 				if ((*look++&0xff) == SE) {
2362 					return (look);
2363 				}
2364 			}
2365 		}
2366 	}
2367 	default:
2368 		return (current+2);
2369 	}
2370 }
2371 #endif	/* 0 */
2372 
2373 /*
2374  * netclear()
2375  *
2376  *	We are about to do a TELNET SYNCH operation.  Clear
2377  * the path to the network.
2378  *
2379  *	Things are a bit tricky since we may have sent the first
2380  * byte or so of a previous TELNET command into the network.
2381  * So, we have to scan the network buffer from the beginning
2382  * until we are up to where we want to be.
2383  *
2384  *	A side effect of what we do, just to keep things
2385  * simple, is to clear the urgent data pointer.  The principal
2386  * caller should be setting the urgent data pointer AFTER calling
2387  * us in any case.
2388  */
2389 
2390 static void
2391 netclear()
2392 {
2393 #if	0	/* XXX */
2394 	register char *thisitem, *next;
2395 	char *good;
2396 #define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \
2397 				((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
2398 
2399 	thisitem = netobuf;
2400 
2401 	while ((next = nextitem(thisitem)) <= netobuf.send) {
2402 		thisitem = next;
2403 	}
2404 
2405 	/* Now, thisitem is first before/at boundary. */
2406 
2407 	good = netobuf;	/* where the good bytes go */
2408 
2409 	while (netoring.add > thisitem) {
2410 		if (wewant(thisitem)) {
2411 			int length;
2412 
2413 			next = thisitem;
2414 			do {
2415 				next = nextitem(next);
2416 			} while (wewant(next) && (nfrontp > next));
2417 			length = next-thisitem;
2418 			memcpy(good, thisitem, length);
2419 			good += length;
2420 			thisitem = next;
2421 		} else {
2422 			thisitem = nextitem(thisitem);
2423 		}
2424 	}
2425 
2426 #endif	/* 0 */
2427 }
2428 
2429 /*
2430  * These routines add various telnet commands to the data stream.
2431  */
2432 
2433 /*
2434  * doflush -  Send do timing mark (for network connection flush) & then
2435  * get rid of anything in the output buffer.  Return -1 if there was a
2436  * non-EWOULDBLOCK error on the tty flush, and otherwise return 0.
2437  */
2438 static int
2439 doflush()
2440 {
2441 	NET2ADD(IAC, DO);
2442 	NETADD(TELOPT_TM);
2443 	flushline = 1;
2444 	flushout = 1;
2445 
2446 	/* Drop pending tty output */
2447 	if (ttyflush(1) == -2)
2448 		return (-1);
2449 
2450 	/* do printoption AFTER flush, otherwise the output gets tossed... */
2451 	printoption("SENT", DO, TELOPT_TM);
2452 	return (0);
2453 }
2454 
2455 int
2456 xmitAO()
2457 {
2458 	NET2ADD(IAC, AO);
2459 	printoption("SENT", IAC, AO);
2460 	if (autoflush) {
2461 		if (doflush() == -1)
2462 			return (-1);
2463 	}
2464 	return (0);
2465 }
2466 
2467 
2468 void
2469 xmitEL()
2470 {
2471 	NET2ADD(IAC, EL);
2472 	printoption("SENT", IAC, EL);
2473 }
2474 
2475 void
2476 xmitEC()
2477 {
2478 	NET2ADD(IAC, EC);
2479 	printoption("SENT", IAC, EC);
2480 }
2481 
2482 
2483 int
2484 dosynch()
2485 {
2486 	netclear();			/* clear the path to the network */
2487 	NETADD(IAC);
2488 	setneturg();
2489 	NETADD(DM);
2490 	printoption("SENT", IAC, DM);
2491 	return (1);
2492 }
2493 
2494 int want_status_response = 0;
2495 
2496 int
2497 get_status()
2498 {
2499 	unsigned char tmp[16];
2500 	register unsigned char *cp;
2501 
2502 	if (my_want_state_is_dont(TELOPT_STATUS)) {
2503 		(void) printf("Remote side does not support STATUS option\n");
2504 		return (0);
2505 	}
2506 	cp = tmp;
2507 
2508 	*cp++ = IAC;
2509 	*cp++ = SB;
2510 	*cp++ = TELOPT_STATUS;
2511 	*cp++ = TELQUAL_SEND;
2512 	*cp++ = IAC;
2513 	*cp++ = SE;
2514 	if (NETROOM() >= cp - tmp) {
2515 		ring_supply_data(&netoring, tmp, cp-tmp);
2516 		printsub('>', tmp+2, cp - tmp - 2);
2517 	}
2518 	++want_status_response;
2519 	return (1);
2520 }
2521 
2522 void
2523 intp()
2524 {
2525 	NET2ADD(IAC, IP);
2526 	printoption("SENT", IAC, IP);
2527 	flushline = 1;
2528 	if (autoflush) {
2529 		/* Ignore return as we're ending off anyway. */
2530 		(void) doflush();
2531 	}
2532 	if (autosynch) {
2533 		(void) dosynch();
2534 	}
2535 }
2536 
2537 int
2538 sendbrk()
2539 {
2540 	NET2ADD(IAC, BREAK);
2541 	printoption("SENT", IAC, BREAK);
2542 	flushline = 1;
2543 	if (autoflush) {
2544 		if (doflush() == -1)
2545 			return (-1);
2546 	}
2547 	if (autosynch) {
2548 		(void) dosynch();
2549 	}
2550 	return (0);
2551 }
2552 
2553 void
2554 sendabort()
2555 {
2556 	NET2ADD(IAC, ABORT);
2557 	printoption("SENT", IAC, ABORT);
2558 	flushline = 1;
2559 	if (autoflush) {
2560 		/*
2561 		 * Since sendabort() gets called while aborting,
2562 		 * ignore the doflush() return
2563 		 */
2564 		(void) doflush();
2565 	}
2566 	if (autosynch) {
2567 		(void) dosynch();
2568 	}
2569 }
2570 
2571 void
2572 sendsusp()
2573 {
2574 	NET2ADD(IAC, SUSP);
2575 	printoption("SENT", IAC, SUSP);
2576 	flushline = 1;
2577 	if (autoflush) {
2578 		if (doflush() == -1) {
2579 			/* The following will not return. */
2580 			fatal_tty_error("write");
2581 		}
2582 	}
2583 	if (autosynch) {
2584 		(void) dosynch();
2585 	}
2586 }
2587 
2588 static void
2589 sendeof()
2590 {
2591 	NET2ADD(IAC, xEOF);
2592 	printoption("SENT", IAC, xEOF);
2593 }
2594 
2595 /*
2596  * Send a window size update to the remote system.
2597  */
2598 
2599 void
2600 sendnaws()
2601 {
2602 	unsigned short rows, cols;
2603 	unsigned char tmp[16];
2604 	register unsigned char *cp;
2605 
2606 	if (my_state_is_wont(TELOPT_NAWS))
2607 		return;
2608 
2609 #define	PUTSHORT(cp, x) { if ((*cp++ = ((x)>>8)&0xff) == IAC) *cp++ = IAC; \
2610 			    if ((*cp++ = ((x))&0xff) == IAC) *cp++ = IAC; }
2611 
2612 	if (TerminalWindowSize(&rows, &cols) == 0) {	/* Failed */
2613 		return;
2614 	}
2615 
2616 	cp = tmp;
2617 
2618 	*cp++ = IAC;
2619 	*cp++ = SB;
2620 	*cp++ = TELOPT_NAWS;
2621 	PUTSHORT(cp, cols);
2622 	PUTSHORT(cp, rows);
2623 	*cp++ = IAC;
2624 	*cp++ = SE;
2625 	if (NETROOM() >= cp - tmp) {
2626 		ring_supply_data(&netoring, tmp, cp-tmp);
2627 		printsub('>', tmp+2, cp - tmp - 2);
2628 	}
2629 }
2630 
2631 void
2632 tel_enter_binary(rw)
2633 	int rw;
2634 {
2635 	if (rw&1)
2636 		send_do(TELOPT_BINARY, 1);
2637 	if (rw&2)
2638 		send_will(TELOPT_BINARY, 1);
2639 }
2640 
2641 void
2642 tel_leave_binary(rw)
2643 	int rw;
2644 {
2645 	if (rw&1)
2646 		send_dont(TELOPT_BINARY, 1);
2647 	if (rw&2)
2648 		send_wont(TELOPT_BINARY, 1);
2649 }
2650