xref: /dragonfly/usr.bin/telnet/telnet.c (revision 3b0edcf1)
1 /*
2  * Copyright (c) 1988, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)telnet.c	8.4 (Berkeley) 5/30/95
30  * $FreeBSD: src/crypto/telnet/telnet/telnet.c,v 1.4.2.5 2002/04/13 10:59:08 markm Exp $
31  */
32 
33 #include <sys/types.h>
34 
35 /* By the way, we need to include curses.h before telnet.h since,
36  * among other things, telnet.h #defines 'DO', which is a variable
37  * declared in curses.h.
38  */
39 
40 #include <ctype.h>
41 #include <curses.h>
42 #include <signal.h>
43 #include <stdlib.h>
44 #include <term.h>
45 #include <unistd.h>
46 #include <arpa/telnet.h>
47 
48 #include "ring.h"
49 
50 #include "defines.h"
51 #include "externs.h"
52 #include "types.h"
53 #include "general.h"
54 
55 #ifdef	AUTHENTICATION
56 #include <libtelnet/auth.h>
57 #endif
58 #ifdef	ENCRYPTION
59 #include <libtelnet/encrypt.h>
60 #endif
61 #include <libtelnet/misc.h>
62 
63 #define	strip(x) ((my_want_state_is_wont(TELOPT_BINARY)) ? ((x)&0x7f) : (x))
64 
65 static unsigned char	subbuffer[SUBBUFSIZE],
66 			*subpointer, *subend;	 /* buffer for sub-options */
67 #define	SB_CLEAR()	subpointer = subbuffer;
68 #define	SB_TERM()	{ subend = subpointer; SB_CLEAR(); }
69 #define	SB_ACCUM(c)	if (subpointer < (subbuffer+sizeof subbuffer)) { \
70 				*subpointer++ = (c); \
71 			}
72 
73 #define	SB_GET()	((*subpointer++)&0xff)
74 #define	SB_PEEK()	((*subpointer)&0xff)
75 #define	SB_EOF()	(subpointer >= subend)
76 #define	SB_LEN()	(subend - subpointer)
77 
78 char	options[256];		/* The combined options */
79 char	do_dont_resp[256];
80 char	will_wont_resp[256];
81 
82 int
83 	eight = 0,
84 	autologin = 0,	/* Autologin anyone? */
85 	skiprc = 0,
86 	connected,
87 	showoptions,
88 	ISend,		/* trying to send network data in */
89 	telnet_debug = 0,
90 	crmod,
91 	netdata,	/* Print out network data flow */
92 	crlf,		/* Should '\r' be mapped to <CR><LF> (or <CR><NUL>)? */
93 	telnetport,
94 	SYNCHing,	/* we are in TELNET SYNCH mode */
95 	flushout,	/* flush output */
96 	autoflush = 0,	/* flush output when interrupting? */
97 	autosynch,	/* send interrupt characters with SYNCH? */
98 	localflow,	/* we handle flow control locally */
99 	restartany,	/* if flow control enabled, restart on any character */
100 	localchars,	/* we recognize interrupt/quit */
101 	donelclchars,	/* the user has set "localchars" */
102 	donebinarytoggle,	/* the user has put us in binary */
103 	dontlecho,	/* do we suppress local echoing right now? */
104 	globalmode,
105 	doaddrlookup = 1, /* do a reverse address lookup? */
106 	clienteof = 0;
107 
108 char *prompt = NULL;
109 #ifdef ENCRYPTION
110 char line[16];		/* hack around breakage in sra.c :-( !! */
111 #endif
112 
113 cc_t escape;
114 cc_t rlogin;
115 #ifdef	KLUDGELINEMODE
116 cc_t echoc;
117 #endif
118 
119 /*
120  * Telnet receiver states for fsm
121  */
122 #define	TS_DATA		0
123 #define	TS_IAC		1
124 #define	TS_WILL		2
125 #define	TS_WONT		3
126 #define	TS_DO		4
127 #define	TS_DONT		5
128 #define	TS_CR		6
129 #define	TS_SB		7		/* sub-option collection */
130 #define	TS_SE		8		/* looking for sub-option end */
131 
132 static int	telrcv_state;
133 #ifdef	OLD_ENVIRON
134 unsigned char telopt_environ = TELOPT_NEW_ENVIRON;
135 #else
136 # define telopt_environ TELOPT_NEW_ENVIRON
137 #endif
138 
139 jmp_buf	toplevel;
140 jmp_buf	peerdied;
141 
142 int	flushline;
143 int	linemode;
144 
145 #ifdef	KLUDGELINEMODE
146 int	kludgelinemode = 1;
147 #endif
148 
149 static int is_unique(char *, char **, char **);
150 
151 /*
152  * The following are some clocks used to decide how to interpret
153  * the relationship between various variables.
154  */
155 
156 Clocks clocks;
157 
158 /*
159  * Initialize telnet environment.
160  */
161 
162 void
init_telnet(void)163 init_telnet(void)
164 {
165     env_init();
166 
167     SB_CLEAR();
168     ClearArray(options);
169 
170     connected = ISend = localflow = donebinarytoggle = 0;
171 #ifdef	AUTHENTICATION
172 #ifdef	ENCRYPTION
173     auth_encrypt_connect(connected);
174 #endif
175 #endif
176     restartany = -1;
177 
178     SYNCHing = 0;
179 
180     /* Don't change NetTrace */
181 
182     escape = CONTROL(']');
183     rlogin = _POSIX_VDISABLE;
184 #ifdef	KLUDGELINEMODE
185     echoc = CONTROL('E');
186 #endif
187 
188     flushline = 1;
189     telrcv_state = TS_DATA;
190 }
191 
192 
193 /*
194  * These routines are in charge of sending option negotiations
195  * to the other side.
196  *
197  * The basic idea is that we send the negotiation if either side
198  * is in disagreement as to what the current state should be.
199  */
200 
201 void
send_do(int c,int init)202 send_do(int c, int init)
203 {
204     if (init) {
205 	if (((do_dont_resp[c] == 0) && my_state_is_do(c)) ||
206 				my_want_state_is_do(c))
207 	    return;
208 	set_my_want_state_do(c);
209 	do_dont_resp[c]++;
210     }
211     NET2ADD(IAC, DO);
212     NETADD(c);
213     printoption("SENT", DO, c);
214 }
215 
216 void
send_dont(int c,int init)217 send_dont(int c, int init)
218 {
219     if (init) {
220 	if (((do_dont_resp[c] == 0) && my_state_is_dont(c)) ||
221 				my_want_state_is_dont(c))
222 	    return;
223 	set_my_want_state_dont(c);
224 	do_dont_resp[c]++;
225     }
226     NET2ADD(IAC, DONT);
227     NETADD(c);
228     printoption("SENT", DONT, c);
229 }
230 
231 void
send_will(int c,int init)232 send_will(int c, int init)
233 {
234     if (init) {
235 	if (((will_wont_resp[c] == 0) && my_state_is_will(c)) ||
236 				my_want_state_is_will(c))
237 	    return;
238 	set_my_want_state_will(c);
239 	will_wont_resp[c]++;
240     }
241     NET2ADD(IAC, WILL);
242     NETADD(c);
243     printoption("SENT", WILL, c);
244 }
245 
246 void
send_wont(int c,int init)247 send_wont(int c, int init)
248 {
249     if (init) {
250 	if (((will_wont_resp[c] == 0) && my_state_is_wont(c)) ||
251 				my_want_state_is_wont(c))
252 	    return;
253 	set_my_want_state_wont(c);
254 	will_wont_resp[c]++;
255     }
256     NET2ADD(IAC, WONT);
257     NETADD(c);
258     printoption("SENT", WONT, c);
259 }
260 
261 void
willoption(int option)262 willoption(int option)
263 {
264 	int new_state_ok = 0;
265 
266 	if (do_dont_resp[option]) {
267 	    --do_dont_resp[option];
268 	    if (do_dont_resp[option] && my_state_is_do(option))
269 		--do_dont_resp[option];
270 	}
271 
272 	if ((do_dont_resp[option] == 0) && my_want_state_is_dont(option)) {
273 
274 	    switch (option) {
275 
276 	    case TELOPT_ECHO:
277 	    case TELOPT_BINARY:
278 	    case TELOPT_SGA:
279 		settimer(modenegotiated);
280 		/* FALL THROUGH */
281 	    case TELOPT_STATUS:
282 #ifdef	AUTHENTICATION
283 	    case TELOPT_AUTHENTICATION:
284 #endif
285 #ifdef	ENCRYPTION
286 	    case TELOPT_ENCRYPT:
287 #endif /* ENCRYPTION */
288 		new_state_ok = 1;
289 		break;
290 
291 	    case TELOPT_TM:
292 		if (flushout)
293 		    flushout = 0;
294 		/*
295 		 * Special case for TM.  If we get back a WILL,
296 		 * pretend we got back a WONT.
297 		 */
298 		set_my_want_state_dont(option);
299 		set_my_state_dont(option);
300 		return;			/* Never reply to TM will's/wont's */
301 
302 	    case TELOPT_LINEMODE:
303 	    default:
304 		break;
305 	    }
306 
307 	    if (new_state_ok) {
308 		set_my_want_state_do(option);
309 		send_do(option, 0);
310 		setconnmode(0);		/* possibly set new tty mode */
311 	    } else {
312 		do_dont_resp[option]++;
313 		send_dont(option, 0);
314 	    }
315 	}
316 	set_my_state_do(option);
317 #ifdef	ENCRYPTION
318 	if (option == TELOPT_ENCRYPT)
319 		encrypt_send_support();
320 #endif	/* ENCRYPTION */
321 }
322 
323 void
wontoption(int option)324 wontoption(int option)
325 {
326 	if (do_dont_resp[option]) {
327 	    --do_dont_resp[option];
328 	    if (do_dont_resp[option] && my_state_is_dont(option))
329 		--do_dont_resp[option];
330 	}
331 
332 	if ((do_dont_resp[option] == 0) && my_want_state_is_do(option)) {
333 
334 	    switch (option) {
335 
336 #ifdef	KLUDGELINEMODE
337 	    case TELOPT_SGA:
338 		if (!kludgelinemode)
339 		    break;
340 		/* FALL THROUGH */
341 #endif
342 	    case TELOPT_ECHO:
343 		settimer(modenegotiated);
344 		break;
345 
346 	    case TELOPT_TM:
347 		if (flushout)
348 		    flushout = 0;
349 		set_my_want_state_dont(option);
350 		set_my_state_dont(option);
351 		return;		/* Never reply to TM will's/wont's */
352 
353 	    default:
354 		break;
355 	    }
356 	    set_my_want_state_dont(option);
357 	    if (my_state_is_do(option))
358 		send_dont(option, 0);
359 	    setconnmode(0);			/* Set new tty mode */
360 	} else if (option == TELOPT_TM) {
361 	    /*
362 	     * Special case for TM.
363 	     */
364 	    if (flushout)
365 		flushout = 0;
366 	    set_my_want_state_dont(option);
367 	}
368 	set_my_state_dont(option);
369 }
370 
371 static void
dooption(int option)372 dooption(int option)
373 {
374 	int new_state_ok = 0;
375 
376 	if (will_wont_resp[option]) {
377 	    --will_wont_resp[option];
378 	    if (will_wont_resp[option] && my_state_is_will(option))
379 		--will_wont_resp[option];
380 	}
381 
382 	if (will_wont_resp[option] == 0) {
383 	  if (my_want_state_is_wont(option)) {
384 
385 	    switch (option) {
386 
387 	    case TELOPT_TM:
388 		/*
389 		 * Special case for TM.  We send a WILL, but pretend
390 		 * we sent WONT.
391 		 */
392 		send_will(option, 0);
393 		set_my_want_state_wont(TELOPT_TM);
394 		set_my_state_wont(TELOPT_TM);
395 		return;
396 
397 	    case TELOPT_BINARY:		/* binary mode */
398 	    case TELOPT_NAWS:		/* window size */
399 	    case TELOPT_TSPEED:		/* terminal speed */
400 	    case TELOPT_LFLOW:		/* local flow control */
401 	    case TELOPT_TTYPE:		/* terminal type option */
402 	    case TELOPT_SGA:		/* no big deal */
403 #ifdef	ENCRYPTION
404 	    case TELOPT_ENCRYPT:	/* encryption variable option */
405 #endif	/* ENCRYPTION */
406 		new_state_ok = 1;
407 		break;
408 
409 	    case TELOPT_NEW_ENVIRON:	/* New environment variable option */
410 #ifdef	OLD_ENVIRON
411 		if (my_state_is_will(TELOPT_OLD_ENVIRON))
412 			send_wont(TELOPT_OLD_ENVIRON, 1); /* turn off the old */
413 		goto env_common;
414 	    case TELOPT_OLD_ENVIRON:	/* Old environment variable option */
415 		if (my_state_is_will(TELOPT_NEW_ENVIRON))
416 			break;		/* Don't enable if new one is in use! */
417 	    env_common:
418 		telopt_environ = option;
419 #endif
420 		new_state_ok = 1;
421 		break;
422 
423 #ifdef	AUTHENTICATION
424 	    case TELOPT_AUTHENTICATION:
425 		if (autologin)
426 			new_state_ok = 1;
427 		break;
428 #endif
429 
430 	    case TELOPT_XDISPLOC:	/* X Display location */
431 		if (env_getvalue("DISPLAY"))
432 		    new_state_ok = 1;
433 		break;
434 
435 	    case TELOPT_LINEMODE:
436 #ifdef	KLUDGELINEMODE
437 		kludgelinemode = 0;
438 		send_do(TELOPT_SGA, 1);
439 #endif
440 		set_my_want_state_will(TELOPT_LINEMODE);
441 		send_will(option, 0);
442 		set_my_state_will(TELOPT_LINEMODE);
443 		slc_init();
444 		return;
445 
446 	    case TELOPT_ECHO:		/* We're never going to echo... */
447 	    default:
448 		break;
449 	    }
450 
451 	    if (new_state_ok) {
452 		set_my_want_state_will(option);
453 		send_will(option, 0);
454 		setconnmode(0);			/* Set new tty mode */
455 	    } else {
456 		will_wont_resp[option]++;
457 		send_wont(option, 0);
458 	    }
459 	  } else {
460 	    /*
461 	     * Handle options that need more things done after the
462 	     * other side has acknowledged the option.
463 	     */
464 	    switch (option) {
465 	    case TELOPT_LINEMODE:
466 #ifdef	KLUDGELINEMODE
467 		kludgelinemode = 0;
468 		send_do(TELOPT_SGA, 1);
469 #endif
470 		set_my_state_will(option);
471 		slc_init();
472 		send_do(TELOPT_SGA, 0);
473 		return;
474 	    }
475 	  }
476 	}
477 	set_my_state_will(option);
478 }
479 
480 static void
dontoption(int option)481 dontoption(int option)
482 {
483 
484 	if (will_wont_resp[option]) {
485 	    --will_wont_resp[option];
486 	    if (will_wont_resp[option] && my_state_is_wont(option))
487 		--will_wont_resp[option];
488 	}
489 
490 	if ((will_wont_resp[option] == 0) && my_want_state_is_will(option)) {
491 	    switch (option) {
492 	    case TELOPT_LINEMODE:
493 		linemode = 0;	/* put us back to the default state */
494 		break;
495 #ifdef	OLD_ENVIRON
496 	    case TELOPT_NEW_ENVIRON:
497 		/*
498 		 * The new environ option wasn't recognized, try
499 		 * the old one.
500 		 */
501 		send_will(TELOPT_OLD_ENVIRON, 1);
502 		telopt_environ = TELOPT_OLD_ENVIRON;
503 		break;
504 #endif
505 	    }
506 	    /* we always accept a DONT */
507 	    set_my_want_state_wont(option);
508 	    if (my_state_is_will(option))
509 		send_wont(option, 0);
510 	    setconnmode(0);			/* Set new tty mode */
511 	}
512 	set_my_state_wont(option);
513 }
514 
515 /*
516  * Given a buffer returned by tgetent(), this routine will turn
517  * the pipe separated list of names in the buffer into an array
518  * of pointers to null terminated names.  We toss out any bad,
519  * duplicate, or verbose names (names with spaces).
520  */
521 
522 static const char *name_unknown = "UNKNOWN";
523 static const char *unknown[] = { NULL, NULL };
524 
525 static const char **
mklist(char * buf,char * name)526 mklist(char *buf, char *name)
527 {
528 	int n;
529 	char c, *cp, **argvp, *cp2, **argv, **avt;
530 
531 	if (name) {
532 		if (strlen(name) > 40) {
533 			name = NULL;
534 			unknown[0] = name_unknown;
535 		} else {
536 			unknown[0] = name;
537 			upcase(name);
538 		}
539 	} else
540 		unknown[0] = name_unknown;
541 	/*
542 	 * Count up the number of names.
543 	 */
544 	for (n = 1, cp = buf; *cp && *cp != ':'; cp++) {
545 		if (*cp == '|')
546 			n++;
547 	}
548 	/*
549 	 * Allocate an array to put the name pointers into
550 	 */
551 	argv = (char **)malloc((n+3)*sizeof(char *));
552 	if (argv == NULL)
553 		return(unknown);
554 
555 	/*
556 	 * Fill up the array of pointers to names.
557 	 */
558 	*argv = NULL;
559 	argvp = argv+1;
560 	n = 0;
561 	for (cp = cp2 = buf; (c = *cp);  cp++) {
562 		if (c == '|' || c == ':') {
563 			*cp++ = '\0';
564 			/*
565 			 * Skip entries that have spaces or are over 40
566 			 * characters long.  If this is our environment
567 			 * name, then put it up front.  Otherwise, as
568 			 * long as this is not a duplicate name (case
569 			 * insensitive) add it to the list.
570 			 */
571 			if (n || (cp - cp2 > 41))
572 				;
573 			else if (name && (strncasecmp(name, cp2, cp-cp2) == 0))
574 				*argv = cp2;
575 			else if (is_unique(cp2, argv+1, argvp))
576 				*argvp++ = cp2;
577 			if (c == ':')
578 				break;
579 			/*
580 			 * Skip multiple delimiters. Reset cp2 to
581 			 * the beginning of the next name. Reset n,
582 			 * the flag for names with spaces.
583 			 */
584 			while ((c = *cp) == '|')
585 				cp++;
586 			cp2 = cp;
587 			n = 0;
588 		}
589 		/*
590 		 * Skip entries with spaces or non-ascii values.
591 		 * Convert lower case letters to upper case.
592 		 */
593 		if ((c == ' ') || !isascii(c))
594 			n = 1;
595 		else if (islower(c))
596 			*cp = toupper(c);
597 	}
598 
599 	/*
600 	 * Check for an old V6 2 character name.  If the second
601 	 * name points to the beginning of the buffer, and is
602 	 * only 2 characters long, move it to the end of the array.
603 	 */
604 	if ((argv[1] == buf) && (strlen(argv[1]) == 2)) {
605 		--argvp;
606 		for (avt = &argv[1]; avt < argvp; avt++)
607 			*avt = *(avt+1);
608 		*argvp++ = buf;
609 	}
610 
611 	/*
612 	 * Duplicate last name, for TTYPE option, and null
613 	 * terminate the array.  If we didn't find a match on
614 	 * our terminal name, put that name at the beginning.
615 	 */
616 	cp = *(argvp-1);
617 	*argvp++ = cp;
618 	*argvp = NULL;
619 
620 	if (*argv == NULL) {
621 		if (name)
622 			*argv = name;
623 		else {
624 			--argvp;
625 			for (avt = argv; avt < argvp; avt++)
626 				*avt = *(avt+1);
627 		}
628 	}
629 	if (*argv)
630 		return((const char **)argv);
631 	else
632 		return(unknown);
633 }
634 
635 static int
is_unique(char * name,char ** as,char ** ae)636 is_unique(char *name, char **as, char **ae)
637 {
638 	char **ap;
639 	int n;
640 
641 	n = strlen(name) + 1;
642 	for (ap = as; ap < ae; ap++)
643 		if (strncasecmp(*ap, name, n) == 0)
644 			return(0);
645 	return (1);
646 }
647 
648 #ifdef	TERMCAP
649 char termbuf[1024];
650 
651 /*ARGSUSED*/
652 static int
setupterm(char * tname,int fd,int * errp)653 setupterm(char *tname, int fd, int *errp)
654 {
655 	if (tgetent(termbuf, tname) == 1) {
656 		termbuf[1023] = '\0';
657 		if (errp)
658 			*errp = 1;
659 		return(0);
660 	}
661 	if (errp)
662 		*errp = 0;
663 	return(-1);
664 }
665 #else
666 #define	termbuf	ttytype
667 extern char ttytype[];
668 #endif
669 
670 int resettermname = 1;
671 
672 static const char *
gettermname(void)673 gettermname(void)
674 {
675 	char *tname;
676 	static const char **tnamep = NULL;
677 	static const char **next;
678 	int err;
679 
680 	if (resettermname) {
681 		resettermname = 0;
682 		if (tnamep && tnamep != unknown)
683 			free(tnamep);
684 		if ((tname = env_getvalue("TERM")) &&
685 				(setupterm(tname, 1, &err) == 0)) {
686 			tnamep = mklist(termbuf, tname);
687 		} else {
688 			if (tname && (strlen(tname) <= 40)) {
689 				unknown[0] = tname;
690 				upcase(tname);
691 			} else
692 				unknown[0] = name_unknown;
693 			tnamep = unknown;
694 		}
695 		next = tnamep;
696 	}
697 	if (*next == NULL)
698 		next = tnamep;
699 	return(*next++);
700 }
701 /*
702  * suboption()
703  *
704  *	Look at the sub-option buffer, and try to be helpful to the other
705  * side.
706  *
707  *	Currently we recognize:
708  *
709  *		Terminal type, send request.
710  *		Terminal speed (send request).
711  *		Local flow control (is request).
712  *		Linemode
713  */
714 
715 static void
suboption(void)716 suboption(void)
717 {
718     unsigned char subchar;
719 
720     printsub('<', subbuffer, SB_LEN()+2);
721     switch (subchar = SB_GET()) {
722     case TELOPT_TTYPE:
723 	if (my_want_state_is_wont(TELOPT_TTYPE))
724 	    return;
725 	if (SB_EOF() || SB_GET() != TELQUAL_SEND) {
726 	    return;
727 	} else {
728 	    const char *name;
729 	    unsigned char temp[50];
730 	    int len;
731 
732 	    name = gettermname();
733 	    len = strlen(name) + 4 + 2;
734 	    if (len < NETROOM()) {
735 		snprintf(temp, sizeof(temp), "%c%c%c%c%s%c%c",
736 			 IAC, SB, TELOPT_TTYPE, TELQUAL_IS, name, IAC, SE);
737 		ring_supply_data(&netoring, temp, len);
738 		printsub('>', &temp[2], len-2);
739 	    } else {
740 		ExitString("No room in buffer for terminal type.\n", 1);
741 		/*NOTREACHED*/
742 	    }
743 	}
744 	break;
745     case TELOPT_TSPEED:
746 	if (my_want_state_is_wont(TELOPT_TSPEED))
747 	    return;
748 	if (SB_EOF())
749 	    return;
750 	if (SB_GET() == TELQUAL_SEND) {
751 	    long ospeed, ispeed;
752 	    unsigned char temp[50];
753 	    int len;
754 
755 	    TerminalSpeeds(&ispeed, &ospeed);
756 
757 	    snprintf((char *)temp, sizeof(temp), "%c%c%c%c%ld,%ld%c%c",
758 		     IAC, SB, TELOPT_TSPEED, TELQUAL_IS,
759 		     ospeed, ispeed, IAC, SE);
760 	    len = strlen((char *)temp+4) + 4;	/* temp[3] is 0 ... */
761 
762 	    if (len < NETROOM()) {
763 		ring_supply_data(&netoring, temp, len);
764 		printsub('>', temp+2, len - 2);
765 	    }
766 /*@*/	    else printf("lm_will: not enough room in buffer\n");
767 	}
768 	break;
769     case TELOPT_LFLOW:
770 	if (my_want_state_is_wont(TELOPT_LFLOW))
771 	    return;
772 	if (SB_EOF())
773 	    return;
774 	switch(SB_GET()) {
775 	case LFLOW_RESTART_ANY:
776 	    restartany = 1;
777 	    break;
778 	case LFLOW_RESTART_XON:
779 	    restartany = 0;
780 	    break;
781 	case LFLOW_ON:
782 	    localflow = 1;
783 	    break;
784 	case LFLOW_OFF:
785 	    localflow = 0;
786 	    break;
787 	default:
788 	    return;
789 	}
790 	setcommandmode();
791 	setconnmode(0);
792 	break;
793 
794     case TELOPT_LINEMODE:
795 	if (my_want_state_is_wont(TELOPT_LINEMODE))
796 	    return;
797 	if (SB_EOF())
798 	    return;
799 	switch (SB_GET()) {
800 	case WILL:
801 	    lm_will(subpointer, SB_LEN());
802 	    break;
803 	case WONT:
804 	    lm_wont(subpointer, SB_LEN());
805 	    break;
806 	case DO:
807 	    lm_do(subpointer, SB_LEN());
808 	    break;
809 	case DONT:
810 	    lm_dont(subpointer, SB_LEN());
811 	    break;
812 	case LM_SLC:
813 	    slc(subpointer, SB_LEN());
814 	    break;
815 	case LM_MODE:
816 	    lm_mode(subpointer, SB_LEN(), 0);
817 	    break;
818 	default:
819 	    break;
820 	}
821 	break;
822 
823 #ifdef	OLD_ENVIRON
824     case TELOPT_OLD_ENVIRON:
825 #endif
826     case TELOPT_NEW_ENVIRON:
827 	if (SB_EOF())
828 	    return;
829 	switch(SB_PEEK()) {
830 	case TELQUAL_IS:
831 	case TELQUAL_INFO:
832 	    if (my_want_state_is_dont(subchar))
833 		return;
834 	    break;
835 	case TELQUAL_SEND:
836 	    if (my_want_state_is_wont(subchar)) {
837 		return;
838 	    }
839 	    break;
840 	default:
841 	    return;
842 	}
843 	env_opt(subpointer, SB_LEN());
844 	break;
845 
846     case TELOPT_XDISPLOC:
847 	if (my_want_state_is_wont(TELOPT_XDISPLOC))
848 	    return;
849 	if (SB_EOF())
850 	    return;
851 	if (SB_GET() == TELQUAL_SEND) {
852 	    unsigned char temp[50], *dp;
853 	    int len;
854 
855 	    if ((dp = env_getvalue("DISPLAY")) == NULL ||
856 		strlen(dp) > sizeof(temp) - 7) {
857 		/*
858 		 * Something happened, we no longer have a DISPLAY
859 		 * variable.  Or it is too long.  So, turn off the option.
860 		 */
861 		send_wont(TELOPT_XDISPLOC, 1);
862 		break;
863 	    }
864 	    snprintf(temp, sizeof(temp), "%c%c%c%c%s%c%c", IAC, SB,
865 		    TELOPT_XDISPLOC, TELQUAL_IS, dp, IAC, SE);
866 	    len = strlen((char *)temp+4) + 4;	/* temp[3] is 0 ... */
867 
868 	    if (len < NETROOM()) {
869 		ring_supply_data(&netoring, temp, len);
870 		printsub('>', temp+2, len - 2);
871 	    }
872 /*@*/	    else printf("lm_will: not enough room in buffer\n");
873 	}
874 	break;
875 
876 #ifdef	AUTHENTICATION
877 	case TELOPT_AUTHENTICATION: {
878 		if (!autologin)
879 			break;
880 		if (SB_EOF())
881 			return;
882 		switch(SB_GET()) {
883 		case TELQUAL_IS:
884 			if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
885 				return;
886 			auth_is(subpointer, SB_LEN());
887 			break;
888 		case TELQUAL_SEND:
889 			if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
890 				return;
891 			auth_send(subpointer, SB_LEN());
892 			break;
893 		case TELQUAL_REPLY:
894 			if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
895 				return;
896 			auth_reply(subpointer, SB_LEN());
897 			break;
898 		case TELQUAL_NAME:
899 			if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
900 				return;
901 			auth_name(subpointer, SB_LEN());
902 			break;
903 		}
904 	}
905 	break;
906 #endif
907 #ifdef	ENCRYPTION
908 	case TELOPT_ENCRYPT:
909 		if (SB_EOF())
910 			return;
911 		switch(SB_GET()) {
912 		case ENCRYPT_START:
913 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
914 				return;
915 			encrypt_start(subpointer, SB_LEN());
916 			break;
917 		case ENCRYPT_END:
918 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
919 				return;
920 			encrypt_end();
921 			break;
922 		case ENCRYPT_SUPPORT:
923 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
924 				return;
925 			encrypt_support(subpointer, SB_LEN());
926 			break;
927 		case ENCRYPT_REQSTART:
928 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
929 				return;
930 			encrypt_request_start(subpointer, SB_LEN());
931 			break;
932 		case ENCRYPT_REQEND:
933 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
934 				return;
935 			/*
936 			 * We can always send an REQEND so that we cannot
937 			 * get stuck encrypting.  We should only get this
938 			 * if we have been able to get in the correct mode
939 			 * anyhow.
940 			 */
941 			encrypt_request_end();
942 			break;
943 		case ENCRYPT_IS:
944 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
945 				return;
946 			encrypt_is(subpointer, SB_LEN());
947 			break;
948 		case ENCRYPT_REPLY:
949 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
950 				return;
951 			encrypt_reply(subpointer, SB_LEN());
952 			break;
953 		case ENCRYPT_ENC_KEYID:
954 			if (my_want_state_is_dont(TELOPT_ENCRYPT))
955 				return;
956 			encrypt_enc_keyid(subpointer, SB_LEN());
957 			break;
958 		case ENCRYPT_DEC_KEYID:
959 			if (my_want_state_is_wont(TELOPT_ENCRYPT))
960 				return;
961 			encrypt_dec_keyid(subpointer, SB_LEN());
962 			break;
963 		default:
964 			break;
965 		}
966 		break;
967 #endif	/* ENCRYPTION */
968     default:
969 	break;
970     }
971 }
972 
973 static unsigned char str_lm[] = { IAC, SB, TELOPT_LINEMODE, 0, 0, IAC, SE };
974 
975 void
lm_will(unsigned char * cmd,int len)976 lm_will(unsigned char *cmd, int len)
977 {
978     if (len < 1) {
979 /*@*/	printf("lm_will: no command!!!\n");	/* Should not happen... */
980 	return;
981     }
982     switch(cmd[0]) {
983     case LM_FORWARDMASK:	/* We shouldn't ever get this... */
984     default:
985 	str_lm[3] = DONT;
986 	str_lm[4] = cmd[0];
987 	if (NETROOM() > (int)sizeof(str_lm)) {
988 	    ring_supply_data(&netoring, str_lm, sizeof(str_lm));
989 	    printsub('>', &str_lm[2], sizeof(str_lm)-2);
990 	}
991 /*@*/	else printf("lm_will: not enough room in buffer\n");
992 	break;
993     }
994 }
995 
996 void
lm_wont(unsigned char * cmd,int len)997 lm_wont(unsigned char *cmd, int len)
998 {
999     if (len < 1) {
1000 /*@*/	printf("lm_wont: no command!!!\n");	/* Should not happen... */
1001 	return;
1002     }
1003     switch(cmd[0]) {
1004     case LM_FORWARDMASK:	/* We shouldn't ever get this... */
1005     default:
1006 	/* We are always DONT, so don't respond */
1007 	return;
1008     }
1009 }
1010 
1011 void
lm_do(unsigned char * cmd,int len)1012 lm_do(unsigned char *cmd, int len)
1013 {
1014     if (len < 1) {
1015 /*@*/	printf("lm_do: no command!!!\n");	/* Should not happen... */
1016 	return;
1017     }
1018     switch(cmd[0]) {
1019     case LM_FORWARDMASK:
1020     default:
1021 	str_lm[3] = WONT;
1022 	str_lm[4] = cmd[0];
1023 	if (NETROOM() > (int)sizeof(str_lm)) {
1024 	    ring_supply_data(&netoring, str_lm, sizeof(str_lm));
1025 	    printsub('>', &str_lm[2], sizeof(str_lm)-2);
1026 	}
1027 /*@*/	else printf("lm_do: not enough room in buffer\n");
1028 	break;
1029     }
1030 }
1031 
1032 void
lm_dont(unsigned char * cmd,int len)1033 lm_dont(unsigned char *cmd, int len)
1034 {
1035     if (len < 1) {
1036 /*@*/	printf("lm_dont: no command!!!\n");	/* Should not happen... */
1037 	return;
1038     }
1039     switch(cmd[0]) {
1040     case LM_FORWARDMASK:
1041     default:
1042 	/* we are always WONT, so don't respond */
1043 	break;
1044     }
1045 }
1046 
1047 static unsigned char str_lm_mode[] = {
1048 	IAC, SB, TELOPT_LINEMODE, LM_MODE, 0, IAC, SE
1049 };
1050 
1051 void
lm_mode(unsigned char * cmd,int len,int init)1052 lm_mode(unsigned char *cmd, int len, int init)
1053 {
1054 	if (len != 1)
1055 		return;
1056 	if ((linemode&MODE_MASK&~MODE_ACK) == *cmd)
1057 		return;
1058 	if (*cmd&MODE_ACK)
1059 		return;
1060 	linemode = *cmd&(MODE_MASK&~MODE_ACK);
1061 	str_lm_mode[4] = linemode;
1062 	if (!init)
1063 	    str_lm_mode[4] |= MODE_ACK;
1064 	if (NETROOM() > (int)sizeof(str_lm_mode)) {
1065 	    ring_supply_data(&netoring, str_lm_mode, sizeof(str_lm_mode));
1066 	    printsub('>', &str_lm_mode[2], sizeof(str_lm_mode)-2);
1067 	}
1068 /*@*/	else printf("lm_mode: not enough room in buffer\n");
1069 	setconnmode(0);	/* set changed mode */
1070 }
1071 
1072 
1073 
1074 /*
1075  * slc()
1076  * Handle special character suboption of LINEMODE.
1077  */
1078 
1079 struct spc {
1080 	cc_t val;
1081 	cc_t *valp;
1082 	char flags;	/* Current flags & level */
1083 	char mylevel;	/* Maximum level & flags */
1084 } spc_data[NSLC+1];
1085 
1086 #define SLC_IMPORT	0
1087 #define	SLC_EXPORT	1
1088 #define SLC_RVALUE	2
1089 static int slc_mode = SLC_EXPORT;
1090 
1091 void
slc_init(void)1092 slc_init(void)
1093 {
1094 	struct spc *spcp;
1095 
1096 	localchars = 1;
1097 	for (spcp = spc_data; spcp < &spc_data[NSLC+1]; spcp++) {
1098 		spcp->val = 0;
1099 		spcp->valp = NULL;
1100 		spcp->flags = spcp->mylevel = SLC_NOSUPPORT;
1101 	}
1102 
1103 #define	initfunc(func, flags) { \
1104 					spcp = &spc_data[func]; \
1105 					if ((spcp->valp = tcval(func))) { \
1106 					    spcp->val = *spcp->valp; \
1107 					    spcp->mylevel = SLC_VARIABLE|flags; \
1108 					} else { \
1109 					    spcp->val = 0; \
1110 					    spcp->mylevel = SLC_DEFAULT; \
1111 					} \
1112 				    }
1113 
1114 	initfunc(SLC_SYNCH, 0);
1115 	/* No BRK */
1116 	initfunc(SLC_AO, 0);
1117 	initfunc(SLC_AYT, 0);
1118 	/* No EOR */
1119 	initfunc(SLC_ABORT, SLC_FLUSHIN|SLC_FLUSHOUT);
1120 	initfunc(SLC_EOF, 0);
1121 #ifndef	SYSV_TERMIO
1122 	initfunc(SLC_SUSP, SLC_FLUSHIN);
1123 #endif
1124 	initfunc(SLC_EC, 0);
1125 	initfunc(SLC_EL, 0);
1126 #ifndef	SYSV_TERMIO
1127 	initfunc(SLC_EW, 0);
1128 	initfunc(SLC_RP, 0);
1129 	initfunc(SLC_LNEXT, 0);
1130 #endif
1131 	initfunc(SLC_XON, 0);
1132 	initfunc(SLC_XOFF, 0);
1133 #ifdef	SYSV_TERMIO
1134 	spc_data[SLC_XON].mylevel = SLC_CANTCHANGE;
1135 	spc_data[SLC_XOFF].mylevel = SLC_CANTCHANGE;
1136 #endif
1137 	initfunc(SLC_FORW1, 0);
1138 #ifdef	USE_TERMIO
1139 	initfunc(SLC_FORW2, 0);
1140 	/* No FORW2 */
1141 #endif
1142 
1143 	initfunc(SLC_IP, SLC_FLUSHIN|SLC_FLUSHOUT);
1144 #undef	initfunc
1145 
1146 	if (slc_mode == SLC_EXPORT)
1147 		slc_export();
1148 	else
1149 		slc_import(1);
1150 
1151 }
1152 
1153 void
slcstate(void)1154 slcstate(void)
1155 {
1156     printf("Special characters are %s values\n",
1157 		slc_mode == SLC_IMPORT ? "remote default" :
1158 		slc_mode == SLC_EXPORT ? "local" :
1159 					 "remote");
1160 }
1161 
1162 void
slc_mode_export(void)1163 slc_mode_export(void)
1164 {
1165     slc_mode = SLC_EXPORT;
1166     if (my_state_is_will(TELOPT_LINEMODE))
1167 	slc_export();
1168 }
1169 
1170 void
slc_mode_import(int def)1171 slc_mode_import(int def)
1172 {
1173     slc_mode = def ? SLC_IMPORT : SLC_RVALUE;
1174     if (my_state_is_will(TELOPT_LINEMODE))
1175 	slc_import(def);
1176 }
1177 
1178 unsigned char slc_import_val[] = {
1179 	IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_VARIABLE, 0, IAC, SE
1180 };
1181 unsigned char slc_import_def[] = {
1182 	IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_DEFAULT, 0, IAC, SE
1183 };
1184 
1185 void
slc_import(int def)1186 slc_import(int def)
1187 {
1188     if (NETROOM() > (int)sizeof(slc_import_val)) {
1189 	if (def) {
1190 	    ring_supply_data(&netoring, slc_import_def, sizeof(slc_import_def));
1191 	    printsub('>', &slc_import_def[2], sizeof(slc_import_def)-2);
1192 	} else {
1193 	    ring_supply_data(&netoring, slc_import_val, sizeof(slc_import_val));
1194 	    printsub('>', &slc_import_val[2], sizeof(slc_import_val)-2);
1195 	}
1196     }
1197 /*@*/ else printf("slc_import: not enough room\n");
1198 }
1199 
1200 void
slc_export(void)1201 slc_export(void)
1202 {
1203     struct spc *spcp;
1204 
1205     TerminalDefaultChars();
1206 
1207     slc_start_reply();
1208     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1209 	if (spcp->mylevel != SLC_NOSUPPORT) {
1210 	    if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1211 		spcp->flags = SLC_NOSUPPORT;
1212 	    else
1213 		spcp->flags = spcp->mylevel;
1214 	    if (spcp->valp)
1215 		spcp->val = *spcp->valp;
1216 	    slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1217 	}
1218     }
1219     slc_end_reply();
1220     (void)slc_update();
1221     setconnmode(1);	/* Make sure the character values are set */
1222 }
1223 
1224 void
slc(unsigned char * cp,int len)1225 slc(unsigned char *cp, int len)
1226 {
1227 	struct spc *spcp;
1228 	int func,level;
1229 
1230 	slc_start_reply();
1231 
1232 	for (; len >= 3; len -=3, cp +=3) {
1233 
1234 		func = cp[SLC_FUNC];
1235 
1236 		if (func == 0) {
1237 			/*
1238 			 * Client side: always ignore 0 function.
1239 			 */
1240 			continue;
1241 		}
1242 		if (func > NSLC) {
1243 			if ((cp[SLC_FLAGS] & SLC_LEVELBITS) != SLC_NOSUPPORT)
1244 				slc_add_reply(func, SLC_NOSUPPORT, 0);
1245 			continue;
1246 		}
1247 
1248 		spcp = &spc_data[func];
1249 
1250 		level = cp[SLC_FLAGS]&(SLC_LEVELBITS|SLC_ACK);
1251 
1252 		if ((cp[SLC_VALUE] == (unsigned char)spcp->val) &&
1253 		    ((level&SLC_LEVELBITS) == (spcp->flags&SLC_LEVELBITS))) {
1254 			continue;
1255 		}
1256 
1257 		if (level == (SLC_DEFAULT|SLC_ACK)) {
1258 			/*
1259 			 * This is an error condition, the SLC_ACK
1260 			 * bit should never be set for the SLC_DEFAULT
1261 			 * level.  Our best guess to recover is to
1262 			 * ignore the SLC_ACK bit.
1263 			 */
1264 			cp[SLC_FLAGS] &= ~SLC_ACK;
1265 		}
1266 
1267 		if (level == ((spcp->flags&SLC_LEVELBITS)|SLC_ACK)) {
1268 			spcp->val = (cc_t)cp[SLC_VALUE];
1269 			spcp->flags = cp[SLC_FLAGS];	/* include SLC_ACK */
1270 			continue;
1271 		}
1272 
1273 		level &= ~SLC_ACK;
1274 
1275 		if (level <= (spcp->mylevel&SLC_LEVELBITS)) {
1276 			spcp->flags = cp[SLC_FLAGS]|SLC_ACK;
1277 			spcp->val = (cc_t)cp[SLC_VALUE];
1278 		}
1279 		if (level == SLC_DEFAULT) {
1280 			if ((spcp->mylevel&SLC_LEVELBITS) != SLC_DEFAULT)
1281 				spcp->flags = spcp->mylevel;
1282 			else
1283 				spcp->flags = SLC_NOSUPPORT;
1284 		}
1285 		slc_add_reply(func, spcp->flags, spcp->val);
1286 	}
1287 	slc_end_reply();
1288 	if (slc_update())
1289 		setconnmode(1);	/* set the  new character values */
1290 }
1291 
1292 void
slc_check(void)1293 slc_check(void)
1294 {
1295     struct spc *spcp;
1296 
1297     slc_start_reply();
1298     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1299 	if (spcp->valp && spcp->val != *spcp->valp) {
1300 	    spcp->val = *spcp->valp;
1301 	    if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1302 		spcp->flags = SLC_NOSUPPORT;
1303 	    else
1304 		spcp->flags = spcp->mylevel;
1305 	    slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1306 	}
1307     }
1308     slc_end_reply();
1309     setconnmode(1);
1310 }
1311 
1312 unsigned char slc_reply[128];
1313 unsigned char const * const slc_reply_eom = &slc_reply[sizeof(slc_reply)];
1314 unsigned char *slc_replyp;
1315 
1316 void
slc_start_reply(void)1317 slc_start_reply(void)
1318 {
1319 	slc_replyp = slc_reply;
1320 	*slc_replyp++ = IAC;
1321 	*slc_replyp++ = SB;
1322 	*slc_replyp++ = TELOPT_LINEMODE;
1323 	*slc_replyp++ = LM_SLC;
1324 }
1325 
1326 void
slc_add_reply(unsigned char func,unsigned char flags,cc_t value)1327 slc_add_reply(unsigned char func, unsigned char flags, cc_t value)
1328 {
1329 	/* A sequence of up to 6 bytes my be written for this member of the SLC
1330 	 * suboption list by this function.  The end of negotiation command,
1331 	 * which is written by slc_end_reply(), will require 2 additional
1332 	 * bytes.  Do not proceed unless there is sufficient space for these
1333 	 * items.
1334 	 */
1335 	if (&slc_replyp[6+2] > slc_reply_eom)
1336 		return;
1337 	if ((*slc_replyp++ = func) == IAC)
1338 		*slc_replyp++ = IAC;
1339 	if ((*slc_replyp++ = flags) == IAC)
1340 		*slc_replyp++ = IAC;
1341 	if ((*slc_replyp++ = (unsigned char)value) == IAC)
1342 		*slc_replyp++ = IAC;
1343 }
1344 
1345 void
slc_end_reply(void)1346 slc_end_reply(void)
1347 {
1348     int len;
1349     /* The end of negotiation command requires 2 bytes. */
1350     if (&slc_replyp[2] > slc_reply_eom)
1351 	return;
1352     *slc_replyp++ = IAC;
1353     *slc_replyp++ = SE;
1354     len = slc_replyp - slc_reply;
1355     if (len <= 6)
1356 	return;
1357     if (NETROOM() > len) {
1358 	ring_supply_data(&netoring, slc_reply, slc_replyp - slc_reply);
1359 	printsub('>', &slc_reply[2], slc_replyp - slc_reply - 2);
1360     }
1361 /*@*/else printf("slc_end_reply: not enough room\n");
1362 }
1363 
1364 int
slc_update(void)1365 slc_update(void)
1366 {
1367 	struct spc *spcp;
1368 	int need_update = 0;
1369 
1370 	for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1371 		if (!(spcp->flags&SLC_ACK))
1372 			continue;
1373 		spcp->flags &= ~SLC_ACK;
1374 		if (spcp->valp && (*spcp->valp != spcp->val)) {
1375 			*spcp->valp = spcp->val;
1376 			need_update = 1;
1377 		}
1378 	}
1379 	return(need_update);
1380 }
1381 
1382 #ifdef	OLD_ENVIRON
1383 # ifdef	ENV_HACK
1384 /*
1385  * Earlier version of telnet/telnetd from the BSD code had
1386  * the definitions of VALUE and VAR reversed.  To ensure
1387  * maximum interoperability, we assume that the server is
1388  * an older BSD server, until proven otherwise.  The newer
1389  * BSD servers should be able to handle either definition,
1390  * so it is better to use the wrong values if we don't
1391  * know what type of server it is.
1392  */
1393 int env_auto = 1;
1394 int old_env_var = OLD_ENV_VAR;
1395 int old_env_value = OLD_ENV_VALUE;
1396 # else
1397 #  define old_env_var OLD_ENV_VAR
1398 #  define old_env_value OLD_ENV_VALUE
1399 # endif
1400 #endif
1401 
1402 void
env_opt(unsigned char * buf,int len)1403 env_opt(unsigned char *buf, int len)
1404 {
1405 	unsigned char *ep = NULL, *epc = NULL;
1406 	int i;
1407 
1408 	switch(buf[0]&0xff) {
1409 	case TELQUAL_SEND:
1410 		env_opt_start();
1411 		if (len == 1) {
1412 			env_opt_add(NULL);
1413 		} else for (i = 1; i < len; i++) {
1414 			switch (buf[i]&0xff) {
1415 #ifdef	OLD_ENVIRON
1416 			case OLD_ENV_VAR:
1417 # ifdef	ENV_HACK
1418 				if (telopt_environ == TELOPT_OLD_ENVIRON
1419 				    && env_auto) {
1420 					/* Server has the same definitions */
1421 					old_env_var = OLD_ENV_VAR;
1422 					old_env_value = OLD_ENV_VALUE;
1423 				}
1424 				/* FALL THROUGH */
1425 # endif
1426 			case OLD_ENV_VALUE:
1427 				/*
1428 				 * Although OLD_ENV_VALUE is not legal, we will
1429 				 * still recognize it, just in case it is an
1430 				 * old server that has VAR & VALUE mixed up...
1431 				 */
1432 				/* FALL THROUGH */
1433 #else
1434 			case NEW_ENV_VAR:
1435 #endif
1436 			case ENV_USERVAR:
1437 				if (ep) {
1438 					*epc = 0;
1439 					env_opt_add(ep);
1440 				}
1441 				ep = epc = &buf[i+1];
1442 				break;
1443 			case ENV_ESC:
1444 				i++;
1445 				/*FALL THROUGH*/
1446 			default:
1447 				if (epc)
1448 					*epc++ = buf[i];
1449 				break;
1450 			}
1451 		}
1452 		if (ep) {
1453 			*epc = 0;
1454 			env_opt_add(ep);
1455 		}
1456 		env_opt_end(1);
1457 		break;
1458 
1459 	case TELQUAL_IS:
1460 	case TELQUAL_INFO:
1461 		/* Ignore for now.  We shouldn't get it anyway. */
1462 		break;
1463 
1464 	default:
1465 		break;
1466 	}
1467 }
1468 
1469 #define	OPT_REPLY_SIZE	(2 * SUBBUFSIZE)
1470 unsigned char *opt_reply = NULL;
1471 unsigned char *opt_replyp;
1472 unsigned char *opt_replyend;
1473 
1474 void
env_opt_start(void)1475 env_opt_start(void)
1476 {
1477 	if (opt_reply)
1478 		opt_reply = (unsigned char *)realloc(opt_reply, OPT_REPLY_SIZE);
1479 	else
1480 		opt_reply = (unsigned char *)malloc(OPT_REPLY_SIZE);
1481 	if (opt_reply == NULL) {
1482 /*@*/		printf("env_opt_start: malloc()/realloc() failed!!!\n");
1483 		opt_reply = opt_replyp = opt_replyend = NULL;
1484 		return;
1485 	}
1486 	opt_replyp = opt_reply;
1487 	opt_replyend = opt_reply + OPT_REPLY_SIZE;
1488 	*opt_replyp++ = IAC;
1489 	*opt_replyp++ = SB;
1490 	*opt_replyp++ = telopt_environ;
1491 	*opt_replyp++ = TELQUAL_IS;
1492 }
1493 
1494 void
env_opt_start_info(void)1495 env_opt_start_info(void)
1496 {
1497 	env_opt_start();
1498 	if (opt_replyp)
1499 	    opt_replyp[-1] = TELQUAL_INFO;
1500 }
1501 
1502 void
env_opt_add(unsigned char * ep)1503 env_opt_add(unsigned char *ep)
1504 {
1505 	unsigned char *vp, c;
1506 
1507 	if (opt_reply == NULL)		/*XXX*/
1508 		return;			/*XXX*/
1509 
1510 	if (ep == NULL || *ep == '\0') {
1511 		/* Send user defined variables first. */
1512 		env_default(1, 0);
1513 		while ((ep = env_default(0, 0)))
1514 			env_opt_add(ep);
1515 
1516 		/* Now add the list of well know variables.  */
1517 		env_default(1, 1);
1518 		while ((ep = env_default(0, 1)))
1519 			env_opt_add(ep);
1520 		return;
1521 	}
1522 	vp = env_getvalue(ep);
1523 	if (opt_replyp + (vp ? 2 * strlen((char *)vp) : 0) +
1524 				2 * strlen((char *)ep) + 6 > opt_replyend)
1525 	{
1526 
1527 		int len;
1528 		opt_replyend += OPT_REPLY_SIZE;
1529 		len = opt_replyend - opt_reply;
1530 		opt_reply = (unsigned char *)realloc(opt_reply, len);
1531 		if (opt_reply == NULL) {
1532 /*@*/			printf("env_opt_add: realloc() failed!!!\n");
1533 			opt_reply = opt_replyp = opt_replyend = NULL;
1534 			return;
1535 		}
1536 		opt_replyp = opt_reply + len - (opt_replyend - opt_replyp);
1537 		opt_replyend = opt_reply + len;
1538 	}
1539 	if (opt_welldefined(ep))
1540 #ifdef	OLD_ENVIRON
1541 		if (telopt_environ == TELOPT_OLD_ENVIRON)
1542 			*opt_replyp++ = old_env_var;
1543 		else
1544 #endif
1545 			*opt_replyp++ = NEW_ENV_VAR;
1546 	else
1547 		*opt_replyp++ = ENV_USERVAR;
1548 	for (;;) {
1549 		while ((c = *ep++)) {
1550 			if (opt_replyp + (2 + 2) > opt_replyend)
1551 				return;
1552 			switch(c&0xff) {
1553 			case IAC:
1554 				*opt_replyp++ = IAC;
1555 				break;
1556 			case NEW_ENV_VAR:
1557 			case NEW_ENV_VALUE:
1558 			case ENV_ESC:
1559 			case ENV_USERVAR:
1560 				*opt_replyp++ = ENV_ESC;
1561 				break;
1562 			}
1563 			*opt_replyp++ = c;
1564 		}
1565 		if ((ep = vp)) {
1566 			if (opt_replyp + (1 + 2 + 2) > opt_replyend)
1567 				return;
1568 #ifdef	OLD_ENVIRON
1569 			if (telopt_environ == TELOPT_OLD_ENVIRON)
1570 				*opt_replyp++ = old_env_value;
1571 			else
1572 #endif
1573 				*opt_replyp++ = NEW_ENV_VALUE;
1574 			vp = NULL;
1575 		} else
1576 			break;
1577 	}
1578 }
1579 
1580 int
opt_welldefined(const char * ep)1581 opt_welldefined(const char *ep)
1582 {
1583 	if ((strcmp(ep, "USER") == 0) ||
1584 	    (strcmp(ep, "DISPLAY") == 0) ||
1585 	    (strcmp(ep, "PRINTER") == 0) ||
1586 	    (strcmp(ep, "SYSTEMTYPE") == 0) ||
1587 	    (strcmp(ep, "JOB") == 0) ||
1588 	    (strcmp(ep, "ACCT") == 0))
1589 		return(1);
1590 	return(0);
1591 }
1592 
1593 void
env_opt_end(int emptyok)1594 env_opt_end(int emptyok)
1595 {
1596 	int len;
1597 
1598 	if (opt_replyp + 2 > opt_replyend)
1599 		return;
1600 	len = opt_replyp + 2 - opt_reply;
1601 	if (emptyok || len > 6) {
1602 		*opt_replyp++ = IAC;
1603 		*opt_replyp++ = SE;
1604 		if (NETROOM() > len) {
1605 			ring_supply_data(&netoring, opt_reply, len);
1606 			printsub('>', &opt_reply[2], len - 2);
1607 		}
1608 /*@*/		else printf("slc_end_reply: not enough room\n");
1609 	}
1610 	if (opt_reply) {
1611 		free(opt_reply);
1612 		opt_reply = opt_replyp = opt_replyend = NULL;
1613 	}
1614 }
1615 
1616 
1617 
1618 int
telrcv(void)1619 telrcv(void)
1620 {
1621     int c;
1622     int scc;
1623     unsigned char *sbp;
1624     int count;
1625     int returnValue = 0;
1626 
1627     scc = 0;
1628     count = 0;
1629     while (TTYROOM() > 2) {
1630 	if (scc == 0) {
1631 	    if (count) {
1632 		ring_consumed(&netiring, count);
1633 		returnValue = 1;
1634 		count = 0;
1635 	    }
1636 	    sbp = netiring.consume;
1637 	    scc = ring_full_consecutive(&netiring);
1638 	    if (scc == 0) {
1639 		/* No more data coming in */
1640 		break;
1641 	    }
1642 	}
1643 
1644 	c = *sbp++ & 0xff, scc--; count++;
1645 #ifdef	ENCRYPTION
1646 	if (decrypt_input)
1647 		c = (*decrypt_input)(c);
1648 #endif	/* ENCRYPTION */
1649 
1650 	switch (telrcv_state) {
1651 
1652 	case TS_CR:
1653 	    telrcv_state = TS_DATA;
1654 	    if (c == '\0') {
1655 		break;	/* Ignore \0 after CR */
1656 	    }
1657 	    else if ((c == '\n') && my_want_state_is_dont(TELOPT_ECHO) && !crmod) {
1658 		TTYADD(c);
1659 		break;
1660 	    }
1661 	    /* Else, fall through */
1662 
1663 	case TS_DATA:
1664 	    if (c == IAC) {
1665 		telrcv_state = TS_IAC;
1666 		break;
1667 	    }
1668 		    /*
1669 		     * The 'crmod' hack (see following) is needed
1670 		     * since we can't * set CRMOD on output only.
1671 		     * Machines like MULTICS like to send \r without
1672 		     * \n; since we must turn off CRMOD to get proper
1673 		     * input, the mapping is done here (sigh).
1674 		     */
1675 	    if ((c == '\r') && my_want_state_is_dont(TELOPT_BINARY)) {
1676 		if (scc > 0) {
1677 		    c = *sbp&0xff;
1678 #ifdef	ENCRYPTION
1679 		    if (decrypt_input)
1680 			c = (*decrypt_input)(c);
1681 #endif	/* ENCRYPTION */
1682 		    if (c == 0) {
1683 			sbp++, scc--; count++;
1684 			/* a "true" CR */
1685 			TTYADD('\r');
1686 		    } else if (my_want_state_is_dont(TELOPT_ECHO) &&
1687 					(c == '\n')) {
1688 			sbp++, scc--; count++;
1689 			TTYADD('\n');
1690 		    } else {
1691 #ifdef	ENCRYPTION
1692 			if (decrypt_input)
1693 			    (*decrypt_input)(-1);
1694 #endif	/* ENCRYPTION */
1695 
1696 			TTYADD('\r');
1697 			if (crmod) {
1698 				TTYADD('\n');
1699 			}
1700 		    }
1701 		} else {
1702 		    telrcv_state = TS_CR;
1703 		    TTYADD('\r');
1704 		    if (crmod) {
1705 			    TTYADD('\n');
1706 		    }
1707 		}
1708 	    } else {
1709 		TTYADD(c);
1710 	    }
1711 	    continue;
1712 
1713 	case TS_IAC:
1714 process_iac:
1715 	    switch (c) {
1716 
1717 	    case WILL:
1718 		telrcv_state = TS_WILL;
1719 		continue;
1720 
1721 	    case WONT:
1722 		telrcv_state = TS_WONT;
1723 		continue;
1724 
1725 	    case DO:
1726 		telrcv_state = TS_DO;
1727 		continue;
1728 
1729 	    case DONT:
1730 		telrcv_state = TS_DONT;
1731 		continue;
1732 
1733 	    case DM:
1734 		    /*
1735 		     * We may have missed an urgent notification,
1736 		     * so make sure we flush whatever is in the
1737 		     * buffer currently.
1738 		     */
1739 		printoption("RCVD", IAC, DM);
1740 		SYNCHing = 1;
1741 		(void) ttyflush(1);
1742 		SYNCHing = stilloob();
1743 		settimer(gotDM);
1744 		break;
1745 
1746 	    case SB:
1747 		SB_CLEAR();
1748 		telrcv_state = TS_SB;
1749 		continue;
1750 
1751 	    case IAC:
1752 		TTYADD(IAC);
1753 		break;
1754 
1755 	    case NOP:
1756 	    case GA:
1757 	    default:
1758 		printoption("RCVD", IAC, c);
1759 		break;
1760 	    }
1761 	    telrcv_state = TS_DATA;
1762 	    continue;
1763 
1764 	case TS_WILL:
1765 	    printoption("RCVD", WILL, c);
1766 	    willoption(c);
1767 	    telrcv_state = TS_DATA;
1768 	    continue;
1769 
1770 	case TS_WONT:
1771 	    printoption("RCVD", WONT, c);
1772 	    wontoption(c);
1773 	    telrcv_state = TS_DATA;
1774 	    continue;
1775 
1776 	case TS_DO:
1777 	    printoption("RCVD", DO, c);
1778 	    dooption(c);
1779 	    if (c == TELOPT_NAWS) {
1780 		sendnaws();
1781 	    } else if (c == TELOPT_LFLOW) {
1782 		localflow = 1;
1783 		setcommandmode();
1784 		setconnmode(0);
1785 	    }
1786 	    telrcv_state = TS_DATA;
1787 	    continue;
1788 
1789 	case TS_DONT:
1790 	    printoption("RCVD", DONT, c);
1791 	    dontoption(c);
1792 	    flushline = 1;
1793 	    setconnmode(0);	/* set new tty mode (maybe) */
1794 	    telrcv_state = TS_DATA;
1795 	    continue;
1796 
1797 	case TS_SB:
1798 	    if (c == IAC) {
1799 		telrcv_state = TS_SE;
1800 	    } else {
1801 		SB_ACCUM(c);
1802 	    }
1803 	    continue;
1804 
1805 	case TS_SE:
1806 	    if (c != SE) {
1807 		if (c != IAC) {
1808 		    /*
1809 		     * This is an error.  We only expect to get
1810 		     * "IAC IAC" or "IAC SE".  Several things may
1811 		     * have happend.  An IAC was not doubled, the
1812 		     * IAC SE was left off, or another option got
1813 		     * inserted into the suboption are all possibilities.
1814 		     * If we assume that the IAC was not doubled,
1815 		     * and really the IAC SE was left off, we could
1816 		     * get into an infinate loop here.  So, instead,
1817 		     * we terminate the suboption, and process the
1818 		     * partial suboption if we can.
1819 		     */
1820 		    SB_ACCUM(IAC);
1821 		    SB_ACCUM(c);
1822 		    subpointer -= 2;
1823 		    SB_TERM();
1824 
1825 		    printoption("In SUBOPTION processing, RCVD", IAC, c);
1826 		    suboption();	/* handle sub-option */
1827 		    telrcv_state = TS_IAC;
1828 		    goto process_iac;
1829 		}
1830 		SB_ACCUM(c);
1831 		telrcv_state = TS_SB;
1832 	    } else {
1833 		SB_ACCUM(IAC);
1834 		SB_ACCUM(SE);
1835 		subpointer -= 2;
1836 		SB_TERM();
1837 		suboption();	/* handle sub-option */
1838 		telrcv_state = TS_DATA;
1839 	    }
1840 	}
1841     }
1842     if (count)
1843 	ring_consumed(&netiring, count);
1844     return returnValue||count;
1845 }
1846 
1847 static int bol = 1, local = 0;
1848 
1849 int
rlogin_susp(void)1850 rlogin_susp(void)
1851 {
1852     if (local) {
1853 	local = 0;
1854 	bol = 1;
1855 	command(0, "z\n", 2);
1856 	return(1);
1857     }
1858     return(0);
1859 }
1860 
1861 static int
telsnd(void)1862 telsnd(void)
1863 {
1864     int tcc;
1865     int count;
1866     int returnValue = 0;
1867     unsigned char *tbp;
1868 
1869     tcc = 0;
1870     count = 0;
1871     while (NETROOM() > 2) {
1872 	int sc;
1873 	int c;
1874 
1875 	if (tcc == 0) {
1876 	    if (count) {
1877 		ring_consumed(&ttyiring, count);
1878 		returnValue = 1;
1879 		count = 0;
1880 	    }
1881 	    tbp = ttyiring.consume;
1882 	    tcc = ring_full_consecutive(&ttyiring);
1883 	    if (tcc == 0) {
1884 		break;
1885 	    }
1886 	}
1887 	c = *tbp++ & 0xff, sc = strip(c), tcc--; count++;
1888 	if (rlogin != _POSIX_VDISABLE) {
1889 		if (bol) {
1890 			bol = 0;
1891 			if (sc == rlogin) {
1892 				local = 1;
1893 				continue;
1894 			}
1895 		} else if (local) {
1896 			local = 0;
1897 			if (sc == '.' || c == termEofChar) {
1898 				bol = 1;
1899 				command(0, "close\n", 6);
1900 				continue;
1901 			}
1902 			if (sc == termSuspChar) {
1903 				bol = 1;
1904 				command(0, "z\n", 2);
1905 				continue;
1906 			}
1907 			if (sc == escape) {
1908 				command(0, tbp, tcc);
1909 				bol = 1;
1910 				count += tcc;
1911 				tcc = 0;
1912 				flushline = 1;
1913 				break;
1914 			}
1915 			if (sc != rlogin) {
1916 				++tcc;
1917 				--tbp;
1918 				--count;
1919 				c = sc = rlogin;
1920 			}
1921 		}
1922 		if ((sc == '\n') || (sc == '\r'))
1923 			bol = 1;
1924 	} else if (escape != _POSIX_VDISABLE && sc == escape) {
1925 	    /*
1926 	     * Double escape is a pass through of a single escape character.
1927 	     */
1928 	    if (tcc && strip(*tbp) == escape) {
1929 		tbp++;
1930 		tcc--;
1931 		count++;
1932 		bol = 0;
1933 	    } else {
1934 		command(0, (char *)tbp, tcc);
1935 		bol = 1;
1936 		count += tcc;
1937 		tcc = 0;
1938 		flushline = 1;
1939 		break;
1940 	    }
1941 	} else
1942 	    bol = 0;
1943 #ifdef	KLUDGELINEMODE
1944 	if (kludgelinemode && (globalmode&MODE_EDIT) && (sc == echoc)) {
1945 	    if (tcc > 0 && strip(*tbp) == echoc) {
1946 		tcc--; tbp++; count++;
1947 	    } else {
1948 		dontlecho = !dontlecho;
1949 		settimer(echotoggle);
1950 		setconnmode(0);
1951 		flushline = 1;
1952 		break;
1953 	    }
1954 	}
1955 #endif
1956 	if (MODE_LOCAL_CHARS(globalmode)) {
1957 	    if (TerminalSpecialChars(sc) == 0) {
1958 		bol = 1;
1959 		break;
1960 	    }
1961 	}
1962 	if (my_want_state_is_wont(TELOPT_BINARY)) {
1963 	    switch (c) {
1964 	    case '\n':
1965 		    /*
1966 		     * If we are in CRMOD mode (\r ==> \n)
1967 		     * on our local machine, then probably
1968 		     * a newline (unix) is CRLF (TELNET).
1969 		     */
1970 		if (MODE_LOCAL_CHARS(globalmode)) {
1971 		    NETADD('\r');
1972 		}
1973 		NETADD('\n');
1974 		bol = flushline = 1;
1975 		break;
1976 	    case '\r':
1977 		if (!crlf) {
1978 		    NET2ADD('\r', '\0');
1979 		} else {
1980 		    NET2ADD('\r', '\n');
1981 		}
1982 		bol = flushline = 1;
1983 		break;
1984 	    case IAC:
1985 		NET2ADD(IAC, IAC);
1986 		break;
1987 	    default:
1988 		NETADD(c);
1989 		break;
1990 	    }
1991 	} else if (c == IAC) {
1992 	    NET2ADD(IAC, IAC);
1993 	} else {
1994 	    NETADD(c);
1995 	}
1996     }
1997     if (count)
1998 	ring_consumed(&ttyiring, count);
1999     return returnValue||count;		/* Non-zero if we did anything */
2000 }
2001 
2002 /*
2003  * Scheduler()
2004  *
2005  * Try to do something.
2006  *
2007  * If we do something useful, return 1; else return 0.
2008  *
2009  */
2010 
2011 static int
Scheduler(int block)2012 Scheduler(int block)
2013 {
2014 		/* One wants to be a bit careful about setting returnValue
2015 		 * to one, since a one implies we did some useful work,
2016 		 * and therefore probably won't be called to block next
2017 		 */
2018     int returnValue;
2019     int netin, netout, netex, ttyin, ttyout;
2020 
2021     /* Decide which rings should be processed */
2022 
2023     netout = ring_full_count(&netoring) &&
2024 	    (flushline ||
2025 		(my_want_state_is_wont(TELOPT_LINEMODE)
2026 #ifdef	KLUDGELINEMODE
2027 			&& (!kludgelinemode || my_want_state_is_do(TELOPT_SGA))
2028 #endif
2029 		) ||
2030 			my_want_state_is_will(TELOPT_BINARY));
2031     ttyout = ring_full_count(&ttyoring);
2032 
2033     ttyin = ring_empty_count(&ttyiring) && (clienteof == 0);
2034 
2035     netin = !ISend && ring_empty_count(&netiring);
2036 
2037     netex = !SYNCHing;
2038 
2039     /* Call to system code to process rings */
2040 
2041     returnValue = process_rings(netin, netout, netex, ttyin, ttyout, !block);
2042 
2043     /* Now, look at the input rings, looking for work to do. */
2044 
2045     if (ring_full_count(&ttyiring)) {
2046 	    returnValue |= telsnd();
2047     }
2048 
2049     if (ring_full_count(&netiring)) {
2050 	returnValue |= telrcv();
2051     }
2052     return returnValue;
2053 }
2054 
2055 #ifdef	AUTHENTICATION
2056 #define __unusedhere
2057 #else
2058 #define __unusedhere __unused
2059 #endif
2060 /*
2061  * Select from tty and network...
2062  */
2063 void
telnet(char * user __unusedhere)2064 telnet(char *user __unusedhere)
2065 {
2066     sys_telnet_init();
2067 
2068 #ifdef	AUTHENTICATION
2069 #ifdef	ENCRYPTION
2070     {
2071 	static char local_host[256] = { 0 };
2072 
2073 	if (!local_host[0]) {
2074 		gethostname(local_host, sizeof(local_host));
2075 		local_host[sizeof(local_host)-1] = 0;
2076 	}
2077 	auth_encrypt_init(local_host, hostname, "TELNET", 0);
2078 	auth_encrypt_user(user);
2079     }
2080 #endif
2081 #endif
2082     if (telnetport) {
2083 #ifdef	AUTHENTICATION
2084 	if (autologin)
2085 		send_will(TELOPT_AUTHENTICATION, 1);
2086 #endif
2087 #ifdef	ENCRYPTION
2088 	send_do(TELOPT_ENCRYPT, 1);
2089 	send_will(TELOPT_ENCRYPT, 1);
2090 #endif	/* ENCRYPTION */
2091 	send_do(TELOPT_SGA, 1);
2092 	send_will(TELOPT_TTYPE, 1);
2093 	send_will(TELOPT_NAWS, 1);
2094 	send_will(TELOPT_TSPEED, 1);
2095 	send_will(TELOPT_LFLOW, 1);
2096 	send_will(TELOPT_LINEMODE, 1);
2097 	send_will(TELOPT_NEW_ENVIRON, 1);
2098 	send_do(TELOPT_STATUS, 1);
2099 	if (env_getvalue("DISPLAY"))
2100 	    send_will(TELOPT_XDISPLOC, 1);
2101 	if (eight)
2102 	    tel_enter_binary(eight);
2103     }
2104 
2105     for (;;) {
2106 	int schedValue;
2107 
2108 	while ((schedValue = Scheduler(0)) != 0) {
2109 	    if (schedValue == -1) {
2110 		setcommandmode();
2111 		return;
2112 	    }
2113 	}
2114 
2115 	if (Scheduler(1) == -1) {
2116 	    setcommandmode();
2117 	    return;
2118 	}
2119     }
2120 }
2121 
2122 #if	0	/* XXX - this not being in is a bug */
2123 /*
2124  * nextitem()
2125  *
2126  *	Return the address of the next "item" in the TELNET data
2127  * stream.  This will be the address of the next character if
2128  * the current address is a user data character, or it will
2129  * be the address of the character following the TELNET command
2130  * if the current address is a TELNET IAC ("I Am a Command")
2131  * character.
2132  */
2133 
2134 static char *
2135 nextitem(char *current)
2136 {
2137     if ((*current&0xff) != IAC) {
2138 	return current+1;
2139     }
2140     switch (*(current+1)&0xff) {
2141     case DO:
2142     case DONT:
2143     case WILL:
2144     case WONT:
2145 	return current+3;
2146     case SB:		/* loop forever looking for the SE */
2147 	{
2148 	    char *look = current+2;
2149 
2150 	    for (;;) {
2151 		if ((*look++&0xff) == IAC) {
2152 		    if ((*look++&0xff) == SE) {
2153 			return look;
2154 		    }
2155 		}
2156 	    }
2157 	}
2158     default:
2159 	return current+2;
2160     }
2161 }
2162 #endif	/* 0 */
2163 
2164 /*
2165  * netclear()
2166  *
2167  *	We are about to do a TELNET SYNCH operation.  Clear
2168  * the path to the network.
2169  *
2170  *	Things are a bit tricky since we may have sent the first
2171  * byte or so of a previous TELNET command into the network.
2172  * So, we have to scan the network buffer from the beginning
2173  * until we are up to where we want to be.
2174  *
2175  *	A side effect of what we do, just to keep things
2176  * simple, is to clear the urgent data pointer.  The principal
2177  * caller should be setting the urgent data pointer AFTER calling
2178  * us in any case.
2179  */
2180 
2181 static void
netclear(void)2182 netclear(void)
2183 {
2184 	/* Deleted */
2185 }
2186 
2187 /*
2188  * These routines add various telnet commands to the data stream.
2189  */
2190 
2191 static void
doflush(void)2192 doflush(void)
2193 {
2194     NET2ADD(IAC, DO);
2195     NETADD(TELOPT_TM);
2196     flushline = 1;
2197     flushout = 1;
2198     (void) ttyflush(1);			/* Flush/drop output */
2199     /* do printoption AFTER flush, otherwise the output gets tossed... */
2200     printoption("SENT", DO, TELOPT_TM);
2201 }
2202 
2203 void
xmitAO(void)2204 xmitAO(void)
2205 {
2206     NET2ADD(IAC, AO);
2207     printoption("SENT", IAC, AO);
2208     if (autoflush) {
2209 	doflush();
2210     }
2211 }
2212 
2213 void
xmitEL(void)2214 xmitEL(void)
2215 {
2216     NET2ADD(IAC, EL);
2217     printoption("SENT", IAC, EL);
2218 }
2219 
2220 void
xmitEC(void)2221 xmitEC(void)
2222 {
2223     NET2ADD(IAC, EC);
2224     printoption("SENT", IAC, EC);
2225 }
2226 
2227 int
dosynch(char * ch __unused)2228 dosynch(char *ch __unused)
2229 {
2230     netclear();			/* clear the path to the network */
2231     NETADD(IAC);
2232     setneturg();
2233     NETADD(DM);
2234     printoption("SENT", IAC, DM);
2235     return 1;
2236 }
2237 
2238 int want_status_response = 0;
2239 
2240 int
get_status(char * ch __unused)2241 get_status(char *ch __unused)
2242 {
2243     unsigned char tmp[16];
2244     unsigned char *cp;
2245 
2246     if (my_want_state_is_dont(TELOPT_STATUS)) {
2247 	printf("Remote side does not support STATUS option\n");
2248 	return 0;
2249     }
2250     cp = tmp;
2251 
2252     *cp++ = IAC;
2253     *cp++ = SB;
2254     *cp++ = TELOPT_STATUS;
2255     *cp++ = TELQUAL_SEND;
2256     *cp++ = IAC;
2257     *cp++ = SE;
2258     if (NETROOM() >= cp - tmp) {
2259 	ring_supply_data(&netoring, tmp, cp-tmp);
2260 	printsub('>', tmp+2, cp - tmp - 2);
2261     }
2262     ++want_status_response;
2263     return 1;
2264 }
2265 
2266 void
intp(void)2267 intp(void)
2268 {
2269     NET2ADD(IAC, IP);
2270     printoption("SENT", IAC, IP);
2271     flushline = 1;
2272     if (autoflush) {
2273 	doflush();
2274     }
2275     if (autosynch) {
2276 	dosynch(NULL);
2277     }
2278 }
2279 
2280 void
sendbrk(void)2281 sendbrk(void)
2282 {
2283     NET2ADD(IAC, BREAK);
2284     printoption("SENT", IAC, BREAK);
2285     flushline = 1;
2286     if (autoflush) {
2287 	doflush();
2288     }
2289     if (autosynch) {
2290 	dosynch(NULL);
2291     }
2292 }
2293 
2294 void
sendabort(void)2295 sendabort(void)
2296 {
2297     NET2ADD(IAC, ABORT);
2298     printoption("SENT", IAC, ABORT);
2299     flushline = 1;
2300     if (autoflush) {
2301 	doflush();
2302     }
2303     if (autosynch) {
2304 	dosynch(NULL);
2305     }
2306 }
2307 
2308 void
sendsusp(void)2309 sendsusp(void)
2310 {
2311     NET2ADD(IAC, SUSP);
2312     printoption("SENT", IAC, SUSP);
2313     flushline = 1;
2314     if (autoflush) {
2315 	doflush();
2316     }
2317     if (autosynch) {
2318 	dosynch(NULL);
2319     }
2320 }
2321 
2322 void
sendeof(void)2323 sendeof(void)
2324 {
2325     NET2ADD(IAC, xEOF);
2326     printoption("SENT", IAC, xEOF);
2327 }
2328 
2329 void
sendayt(void)2330 sendayt(void)
2331 {
2332     NET2ADD(IAC, AYT);
2333     printoption("SENT", IAC, AYT);
2334 }
2335 
2336 /*
2337  * Send a window size update to the remote system.
2338  */
2339 
2340 void
sendnaws(void)2341 sendnaws(void)
2342 {
2343     long rows, cols;
2344     unsigned char tmp[16];
2345     unsigned char *cp;
2346 
2347     if (my_state_is_wont(TELOPT_NAWS))
2348 	return;
2349 
2350 #define	PUTSHORT(cp, x) { if ((*cp++ = ((x)>>8)&0xff) == IAC) *cp++ = IAC; \
2351 			    if ((*cp++ = ((x))&0xff) == IAC) *cp++ = IAC; }
2352 
2353     if (TerminalWindowSize(&rows, &cols) == 0) {	/* Failed */
2354 	return;
2355     }
2356 
2357     cp = tmp;
2358 
2359     *cp++ = IAC;
2360     *cp++ = SB;
2361     *cp++ = TELOPT_NAWS;
2362     PUTSHORT(cp, cols);
2363     PUTSHORT(cp, rows);
2364     *cp++ = IAC;
2365     *cp++ = SE;
2366     if (NETROOM() >= cp - tmp) {
2367 	ring_supply_data(&netoring, tmp, cp-tmp);
2368 	printsub('>', tmp+2, cp - tmp - 2);
2369     }
2370 }
2371 
2372 void
tel_enter_binary(int rw)2373 tel_enter_binary(int rw)
2374 {
2375     if (rw&1)
2376 	send_do(TELOPT_BINARY, 1);
2377     if (rw&2)
2378 	send_will(TELOPT_BINARY, 1);
2379 }
2380 
2381 void
tel_leave_binary(int rw)2382 tel_leave_binary(int rw)
2383 {
2384     if (rw&1)
2385 	send_dont(TELOPT_BINARY, 1);
2386     if (rw&2)
2387 	send_wont(TELOPT_BINARY, 1);
2388 }
2389