xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.bin/telnet/commands.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 #pragma ident	"%Z%%M%	%I%	%E% SMI"
2 
3 /*
4  * Copyright (c) 1988, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
36  * Use is subject to license terms.
37  */
38 
39 #ifndef lint
40 static char sccsid[] = "@(#)commands.c	8.1 (Berkeley) 6/6/93";
41 #endif /* not lint */
42 
43 #include <sys/param.h>
44 #include <sys/file.h>
45 #include <sys/socket.h>
46 #include <sys/sysmacros.h>
47 #include <netinet/in.h>
48 
49 #include <signal.h>
50 #include <netdb.h>
51 #include <ctype.h>
52 #include <pwd.h>
53 #include <errno.h>
54 #include <strings.h>
55 
56 #include <arpa/telnet.h>
57 #include <arpa/inet.h>
58 
59 #include "general.h"
60 
61 #include "ring.h"
62 
63 #include "externs.h"
64 #include "defines.h"
65 #include "types.h"
66 
67 extern	char *telnet_krb5_realm;
68 extern	void krb5_profile_get_options(char *, char *,
69 		profile_options_boolean*);
70 
71 #include <k5-int.h>
72 #include <profile/prof_int.h>
73 
74 profile_options_boolean config_file_options[] = {
75 	{ "forwardable", &forwardable_flag, 0},
76 	{ "forward", &forward_flag, 0},
77 	{ "encrypt", &encrypt_flag, 0 },
78 	{ "autologin", &autologin, 0 },
79 	{ NULL, NULL, 0}
80 };
81 
82 #include <netinet/ip.h>
83 
84 /*
85  * Number of maximum IPv4 gateways user can specify. This number is limited by
86  * the maximum size of the IPv4 options in the IPv4 header.
87  */
88 #define	MAX_GATEWAY	8
89 /*
90  * Number of maximum IPv6 gateways user can specify. This number is limited by
91  * the maximum header extension length of the IPv6 routing header.
92  */
93 #define	MAX_GATEWAY6	127
94 #define	MAXMAX_GATEWAY	MAX(MAX_GATEWAY, MAX_GATEWAY6)
95 
96 /*
97  * Depending on the address resolutions of the target and gateways,
98  * we determine which addresses of the target we'll try connecting to.
99  */
100 #define	ALL_ADDRS	0	/* try all addrs of target */
101 #define	ONLY_V4		1	/* try only IPv4 addrs of target */
102 #define	ONLY_V6		2	/* try only IPv6 addrs of target */
103 
104 #if defined(USE_TOS)
105 int tos = -1;
106 #endif
107 
108 char	*hostname;
109 static char _hostname[MAXHOSTNAMELEN];
110 
111 static int send_tncmd(void (*func)(), char *, char *);
112 static void call(int n_ptrs, ...);
113 static int cmdrc(char *, char *);
114 
115 typedef struct {
116 	char	*name;		/* command name */
117 	char	*help;		/* help string (NULL for no help) */
118 	int	(*handler)();	/* routine which executes command */
119 	int	needconnect;	/* Do we need to be connected to execute? */
120 } Command;
121 
122 /*
123  * storage for IPv6 and/or IPv4 addresses of gateways
124  */
125 struct gateway {
126 	struct in6_addr	gw_addr6;
127 	struct in_addr	gw_addr;
128 };
129 
130 /*
131  * IPv4 source routing option.
132  * In order to avoid padding for the alignment of IPv4 addresses, ipsr_addrs
133  * is defined as a 2-D array of uint8_t, instead of 1-D array of struct in_addr.
134  * If it were defined as "struct in_addr ipsr_addrs[1]", "ipsr_ptr" would be
135  * followed by one byte of padding to avoid misaligned struct in_addr.
136  */
137 struct ip_sourceroute {
138 	uint8_t ipsr_code;
139 	uint8_t ipsr_len;
140 	uint8_t ipsr_ptr;
141 	/* up to 9 IPv4 addresses */
142 	uint8_t ipsr_addrs[1][sizeof (struct in_addr)];
143 };
144 
145 static char *line = NULL;
146 static unsigned linesize = 0;
147 static int margc;
148 static char **margv = NULL;
149 static unsigned margvlen = 0;
150 static int doing_rc = 0;   /* .telnetrc file is being read and processed */
151 
152 static void
153 Close(int *fd)
154 {
155 	if (*fd != -1) {
156 		(void) close(*fd);
157 		*fd = -1;
158 	}
159 }
160 
161 static void
162 Free(char **p)
163 {
164 	if (*p != NULL) {
165 		free(*p);
166 		*p = NULL;
167 	}
168 }
169 
170 static void
171 FreeHostnameList(char *list[])
172 {
173 	unsigned i;
174 	for (i = 0; i <= MAXMAX_GATEWAY && list[i] != NULL; i++)
175 		Free(&list[i]);
176 }
177 
178 #define	MARGV_CHUNK_SIZE 8
179 
180 static void
181 set_argv(str)
182 char *str;
183 {
184 	if (margc == margvlen) {
185 		char **newmargv;
186 
187 		margvlen += MARGV_CHUNK_SIZE;
188 
189 		if ((newmargv = realloc(margv, margvlen * sizeof (char *)))
190 			== NULL)
191 			ExitString("telnet: no space for arguments",
192 				EXIT_FAILURE);
193 
194 		margv = newmargv;
195 	}
196 
197 	margv[margc] = str;
198 	if (str != NULL)
199 		margc++;
200 }
201 
202 static void
203 makeargv()
204 {
205 	char *cp, *cp2, c;
206 	boolean_t shellcmd = B_FALSE;
207 
208 	margc = 0;
209 	cp = line;
210 	if (*cp == '!') {		/* Special case shell escape */
211 		set_argv("!");		/* No room in string to get this */
212 		cp++;
213 		shellcmd = B_TRUE;
214 	}
215 	while ((c = *cp) != '\0') {
216 		register int inquote = 0;
217 		while (isspace(c))
218 			c = *++cp;
219 		if (c == '\0')
220 			break;
221 		set_argv(cp);
222 		/*
223 		 * For the shell escape, put the rest of the line, less
224 		 * leading space, into a single argument, breaking out from
225 		 * the loop to prevent the rest of the line being split up
226 		 * into smaller arguments.
227 		 */
228 		if (shellcmd)
229 			break;
230 		for (cp2 = cp; c != '\0'; c = *++cp) {
231 			if (inquote) {
232 				if (c == inquote) {
233 					inquote = 0;
234 					continue;
235 				}
236 			} else {
237 				if (c == '\\') {
238 					if ((c = *++cp) == '\0')
239 						break;
240 				} else if (c == '"') {
241 					inquote = '"';
242 					continue;
243 				} else if (c == '\'') {
244 					inquote = '\'';
245 					continue;
246 				} else if (isspace(c))
247 					break;
248 			}
249 			*cp2++ = c;
250 		}
251 		*cp2 = '\0';
252 		if (c == '\0')
253 			break;
254 		cp++;
255 	}
256 	set_argv((char *)NULL);
257 }
258 
259 /*
260  * Make a character string into a number.
261  *
262  * Todo:  1.  Could take random integers (12, 0x12, 012, 0b1).
263  */
264 
265 	static int
266 special(s)
267 	register char *s;
268 {
269 	register char c;
270 	char b;
271 
272 	switch (*s) {
273 	case '^':
274 		b = *++s;
275 		if (b == '?') {
276 		    c = b | 0x40;		/* DEL */
277 		} else {
278 		    c = b & 0x1f;
279 		}
280 		break;
281 	default:
282 		c = *s;
283 		break;
284 	}
285 	return (c);
286 }
287 
288 /*
289  * Construct a control character sequence
290  * for a special character.
291  */
292 	static char *
293 control(c)
294 	register cc_t c;
295 {
296 	static char buf[5];
297 	/*
298 	 * The only way I could get the Sun 3.5 compiler
299 	 * to shut up about
300 	 *	if ((unsigned int)c >= 0x80)
301 	 * was to assign "c" to an unsigned int variable...
302 	 * Arggg....
303 	 */
304 	register unsigned int uic = (unsigned int)c;
305 
306 	if (uic == 0x7f)
307 		return ("^?");
308 	if (c == (cc_t)_POSIX_VDISABLE) {
309 		return ("off");
310 	}
311 	if (uic >= 0x80) {
312 		buf[0] = '\\';
313 		buf[1] = ((c>>6)&07) + '0';
314 		buf[2] = ((c>>3)&07) + '0';
315 		buf[3] = (c&07) + '0';
316 		buf[4] = 0;
317 	} else if (uic >= 0x20) {
318 		buf[0] = c;
319 		buf[1] = 0;
320 	} else {
321 		buf[0] = '^';
322 		buf[1] = '@'+c;
323 		buf[2] = 0;
324 	}
325 	return (buf);
326 }
327 
328 /*
329  * Same as control() except that its only used for escape handling, which uses
330  * _POSIX_VDISABLE differently and is aided by the use of the state variable
331  * escape_valid.
332  */
333 	static char *
334 esc_control(c)
335 	register cc_t c;
336 {
337 	static char buf[5];
338 	/*
339 	 * The only way I could get the Sun 3.5 compiler
340 	 * to shut up about
341 	 *	if ((unsigned int)c >= 0x80)
342 	 * was to assign "c" to an unsigned int variable...
343 	 * Arggg....
344 	 */
345 	register unsigned int uic = (unsigned int)c;
346 
347 	if (escape_valid == B_FALSE)
348 		return ("off");
349 	if (uic == 0x7f)
350 		return ("^?");
351 	if (uic >= 0x80) {
352 		buf[0] = '\\';
353 		buf[1] = ((c>>6)&07) + '0';
354 		buf[2] = ((c>>3)&07) + '0';
355 		buf[3] = (c&07) + '0';
356 		buf[4] = 0;
357 	} else if (uic >= 0x20) {
358 		buf[0] = c;
359 		buf[1] = 0;
360 	} else {
361 		buf[0] = '^';
362 		buf[1] = '@'+c;
363 		buf[2] = 0;
364 	}
365 	return (buf);
366 }
367 
368 /*
369  *	The following are data structures and routines for
370  *	the "send" command.
371  *
372  */
373 
374 struct sendlist {
375 	char	*name;		/* How user refers to it (case independent) */
376 	char	*help;		/* Help information (0 ==> no help) */
377 	int	needconnect;	/* Need to be connected */
378 	int	narg;		/* Number of arguments */
379 	int	(*handler)();	/* Routine to perform (for special ops) */
380 	int	nbyte;		/* Number of bytes to send this command */
381 	int	what;		/* Character to be sent (<0 ==> special) */
382 };
383 
384 
385 static int send_esc(void);
386 static int send_help(void);
387 static int send_docmd(char *);
388 static int send_dontcmd(char *);
389 static int send_willcmd(char *);
390 static int send_wontcmd(char *);
391 
392 static struct sendlist Sendlist[] = {
393 	{ "ao",	"Send Telnet Abort output",		1, 0, 0, 2, AO },
394 	{ "ayt", "Send Telnet 'Are You There'",		1, 0, 0, 2, AYT },
395 	{ "b", 0,					1, 0, 0, 2, BREAK },
396 	{ "br", 0,					1, 0, 0, 2, BREAK },
397 	{ "break", 0,					1, 0, 0, 2, BREAK },
398 	{ "brk", "Send Telnet Break",			1, 0, 0, 2, BREAK },
399 	{ "ec",	"Send Telnet Erase Character",		1, 0, 0, 2, EC },
400 	{ "el",	"Send Telnet Erase Line",		1, 0, 0, 2, EL },
401 	{ "escape", "Send current escape character",	1, 0, send_esc, 1, 0 },
402 	{ "ga",	"Send Telnet 'Go Ahead' sequence",	1, 0, 0, 2, GA },
403 	{ "ip",	"Send Telnet Interrupt Process",	1, 0, 0, 2, IP },
404 	{ "intp", 0,					1, 0, 0, 2, IP },
405 	{ "interrupt", 0,				1, 0, 0, 2, IP },
406 	{ "intr",	0,				1, 0, 0, 2, IP },
407 	{ "nop", "Send Telnet 'No operation'",		1, 0, 0, 2, NOP },
408 	{ "eor", "Send Telnet 'End of Record'",		1, 0, 0, 2, EOR },
409 	{ "abort", "Send Telnet 'Abort Process'",	1, 0, 0, 2, ABORT },
410 	{ "susp", "Send Telnet 'Suspend Process'",	1, 0, 0, 2, SUSP },
411 	{ "eof", "Send Telnet End of File Character",	1, 0, 0, 2, xEOF },
412 	{ "synch", "Perform Telnet 'Synch operation'",	1, 0, dosynch, 2, 0 },
413 	{ "getstatus", "Send request for STATUS", 1, 0, get_status, 6, 0 },
414 	{ "?",	"Display send options",			0, 0, send_help, 0, 0 },
415 	{ "help",	0,				0, 0, send_help, 0, 0 },
416 	{ "do",	0,				0, 1, send_docmd, 3, 0 },
417 	{ "dont", 0,				0, 1, send_dontcmd, 3, 0 },
418 	{ "will", 0,				0, 1, send_willcmd, 3, 0 },
419 	{ "wont", 0,				0, 1, send_wontcmd, 3, 0 },
420 	{ 0 }
421 };
422 
423 #define	GETSEND(name) ((struct sendlist *)genget(name, (char **)Sendlist, \
424 				sizeof (struct sendlist)))
425 
426 static int
427 sendcmd(argc, argv)
428 	int  argc;
429 	char **argv;
430 {
431 	int count;	/* how many bytes we are going to need to send */
432 	int i;
433 	struct sendlist *s;	/* pointer to current command */
434 	int success = 0;
435 	int needconnect = 0;
436 
437 	if (argc < 2) {
438 		(void) printf(
439 		    "need at least one argument for 'send' command\n");
440 		(void) printf("'send ?' for help\n");
441 		return (0);
442 	}
443 	/*
444 	 * First, validate all the send arguments.
445 	 * In addition, we see how much space we are going to need, and
446 	 * whether or not we will be doing a "SYNCH" operation (which
447 	 * flushes the network queue).
448 	 */
449 	count = 0;
450 	for (i = 1; i < argc; i++) {
451 		s = GETSEND(argv[i]);
452 		if (s == 0) {
453 			(void) printf("Unknown send argument '%s'\n'send ?' "
454 			    "for help.\n", argv[i]);
455 			return (0);
456 		} else if (Ambiguous(s)) {
457 			(void) printf("Ambiguous send argument '%s'\n'send ?' "
458 			    "for help.\n", argv[i]);
459 			return (0);
460 		}
461 		if (i + s->narg >= argc) {
462 			(void) fprintf(stderr,
463 			    "Need %d argument%s to 'send %s' "
464 			    "command.  'send %s ?' for help.\n",
465 			    s->narg, s->narg == 1 ? "" : "s", s->name, s->name);
466 			return (0);
467 		}
468 		count += s->nbyte;
469 		if (s->handler == send_help) {
470 			(void) send_help();
471 			return (0);
472 		}
473 
474 		i += s->narg;
475 		needconnect += s->needconnect;
476 	}
477 	if (!connected && needconnect) {
478 		(void) printf("?Need to be connected first.\n");
479 		(void) printf("'send ?' for help\n");
480 		return (0);
481 	}
482 	/* Now, do we have enough room? */
483 	if (NETROOM() < count) {
484 		(void) printf("There is not enough room in the buffer "
485 		    "TO the network\n");
486 		(void) printf(
487 		    "to process your request.  Nothing will be done.\n");
488 		(void) printf("('send synch' will throw away most "
489 		    "data in the network\n");
490 		(void) printf("buffer, if this might help.)\n");
491 		return (0);
492 	}
493 	/* OK, they are all OK, now go through again and actually send */
494 	count = 0;
495 	for (i = 1; i < argc; i++) {
496 		if ((s = GETSEND(argv[i])) == 0) {
497 			(void) fprintf(stderr,
498 			    "Telnet 'send' error - argument disappeared!\n");
499 			(void) quit();
500 			/*NOTREACHED*/
501 		}
502 		if (s->handler) {
503 			count++;
504 			success += (*s->handler)((s->narg > 0) ? argv[i+1] : 0,
505 			    (s->narg > 1) ? argv[i+2] : 0);
506 			i += s->narg;
507 		} else {
508 			NET2ADD(IAC, s->what);
509 			printoption("SENT", IAC, s->what);
510 		}
511 	}
512 	return (count == success);
513 }
514 
515 static int
516 send_esc()
517 {
518 	NETADD(escape);
519 	return (1);
520 }
521 
522 static int
523 send_docmd(name)
524 	char *name;
525 {
526 	return (send_tncmd(send_do, "do", name));
527 }
528 
529 static int
530 send_dontcmd(name)
531 	char *name;
532 {
533 	return (send_tncmd(send_dont, "dont", name));
534 }
535 
536 static int
537 send_willcmd(name)
538 	char *name;
539 {
540 	return (send_tncmd(send_will, "will", name));
541 }
542 
543 static int
544 send_wontcmd(name)
545 	char *name;
546 {
547 	return (send_tncmd(send_wont, "wont", name));
548 }
549 
550 int
551 send_tncmd(func, cmd, name)
552 	void	(*func)();
553 	char	*cmd, *name;
554 {
555 	char **cpp;
556 	extern char *telopts[];
557 	register int val = 0;
558 
559 	if (isprefix(name, "help") || isprefix(name, "?")) {
560 		register int col, len;
561 
562 		(void) printf("Usage: send %s <value|option>\n", cmd);
563 		(void) printf("\"value\" must be from 0 to 255\n");
564 		(void) printf("Valid options are:\n\t");
565 
566 		col = 8;
567 		for (cpp = telopts; *cpp; cpp++) {
568 			len = strlen(*cpp) + 3;
569 			if (col + len > 65) {
570 				(void) printf("\n\t");
571 				col = 8;
572 			}
573 			(void) printf(" \"%s\"", *cpp);
574 			col += len;
575 		}
576 		(void) printf("\n");
577 		return (0);
578 	}
579 	cpp = (char **)genget(name, telopts, sizeof (char *));
580 	if (Ambiguous(cpp)) {
581 		(void) fprintf(stderr,
582 		    "'%s': ambiguous argument ('send %s ?' for help).\n",
583 		    name, cmd);
584 		return (0);
585 	}
586 	if (cpp) {
587 		val = cpp - telopts;
588 	} else {
589 		register char *cp = name;
590 
591 		while (*cp >= '0' && *cp <= '9') {
592 			val *= 10;
593 			val += *cp - '0';
594 			cp++;
595 		}
596 		if (*cp != 0) {
597 			(void) fprintf(stderr,
598 			    "'%s': unknown argument ('send %s ?' for help).\n",
599 			    name, cmd);
600 			return (0);
601 		} else if (val < 0 || val > 255) {
602 			(void) fprintf(stderr,
603 			    "'%s': bad value ('send %s ?' for help).\n",
604 			    name, cmd);
605 			return (0);
606 		}
607 	}
608 	if (!connected) {
609 		(void) printf("?Need to be connected first.\n");
610 		return (0);
611 	}
612 	(*func)(val, 1);
613 	return (1);
614 }
615 
616 static int
617 send_help()
618 {
619 	struct sendlist *s;	/* pointer to current command */
620 	for (s = Sendlist; s->name; s++) {
621 		if (s->help)
622 			(void) printf("%-15s %s\n", s->name, s->help);
623 	}
624 	return (0);
625 }
626 
627 /*
628  * The following are the routines and data structures referred
629  * to by the arguments to the "toggle" command.
630  */
631 
632 static int
633 lclchars()
634 {
635 	donelclchars = 1;
636 	return (1);
637 }
638 
639 static int
640 togdebug()
641 {
642 	if (net > 0 &&
643 	    (SetSockOpt(net, SOL_SOCKET, SO_DEBUG, debug)) < 0) {
644 		perror("setsockopt (SO_DEBUG)");
645 	}
646 	return (1);
647 }
648 
649 
650 static int
651 togcrlf()
652 {
653 	if (crlf) {
654 		(void) printf(
655 		    "Will send carriage returns as telnet <CR><LF>.\n");
656 	} else {
657 		(void) printf(
658 		    "Will send carriage returns as telnet <CR><NUL>.\n");
659 	}
660 	return (1);
661 }
662 
663 static int binmode;
664 
665 static int
666 togbinary(val)
667 	int val;
668 {
669 	donebinarytoggle = 1;
670 
671 	if (val >= 0) {
672 		binmode = val;
673 	} else {
674 		if (my_want_state_is_will(TELOPT_BINARY) &&
675 		    my_want_state_is_do(TELOPT_BINARY)) {
676 			binmode = 1;
677 		} else if (my_want_state_is_wont(TELOPT_BINARY) &&
678 		    my_want_state_is_dont(TELOPT_BINARY)) {
679 			binmode = 0;
680 		}
681 		val = binmode ? 0 : 1;
682 	}
683 
684 	if (val == 1) {
685 		if (my_want_state_is_will(TELOPT_BINARY) &&
686 		    my_want_state_is_do(TELOPT_BINARY)) {
687 			(void) printf("Already operating in binary mode "
688 			    "with remote host.\n");
689 		} else {
690 			(void) printf(
691 			    "Negotiating binary mode with remote host.\n");
692 			tel_enter_binary(3);
693 		}
694 	} else {
695 		if (my_want_state_is_wont(TELOPT_BINARY) &&
696 		    my_want_state_is_dont(TELOPT_BINARY)) {
697 			(void) printf("Already in network ascii mode "
698 			    "with remote host.\n");
699 		} else {
700 			(void) printf("Negotiating network ascii mode "
701 			    "with remote host.\n");
702 			tel_leave_binary(3);
703 		}
704 	}
705 	return (1);
706 }
707 
708 static int
709 togrbinary(val)
710 	int val;
711 {
712 	donebinarytoggle = 1;
713 
714 	if (val == -1)
715 		val = my_want_state_is_do(TELOPT_BINARY) ? 0 : 1;
716 
717 	if (val == 1) {
718 		if (my_want_state_is_do(TELOPT_BINARY)) {
719 			(void) printf("Already receiving in binary mode.\n");
720 		} else {
721 			(void) printf("Negotiating binary mode on input.\n");
722 			tel_enter_binary(1);
723 		}
724 	} else {
725 		if (my_want_state_is_dont(TELOPT_BINARY)) {
726 			(void) printf(
727 			    "Already receiving in network ascii mode.\n");
728 		} else {
729 			(void) printf(
730 			    "Negotiating network ascii mode on input.\n");
731 			    tel_leave_binary(1);
732 		}
733 	}
734 	return (1);
735 }
736 
737 static int
738 togxbinary(val)
739 	int val;
740 {
741 	donebinarytoggle = 1;
742 
743 	if (val == -1)
744 		val = my_want_state_is_will(TELOPT_BINARY) ? 0 : 1;
745 
746 	if (val == 1) {
747 		if (my_want_state_is_will(TELOPT_BINARY)) {
748 			(void) printf("Already transmitting in binary mode.\n");
749 		} else {
750 			(void) printf("Negotiating binary mode on output.\n");
751 			tel_enter_binary(2);
752 		}
753 	} else {
754 		if (my_want_state_is_wont(TELOPT_BINARY)) {
755 			(void) printf(
756 			    "Already transmitting in network ascii mode.\n");
757 		} else {
758 			(void) printf(
759 			    "Negotiating network ascii mode on output.\n");
760 			tel_leave_binary(2);
761 		}
762 	}
763 	return (1);
764 }
765 
766 
767 static int togglehelp(void);
768 extern int auth_togdebug(int);
769 
770 struct togglelist {
771 	char	*name;		/* name of toggle */
772 	char	*help;		/* help message */
773 	int	(*handler)();	/* routine to do actual setting */
774 	int	*variable;
775 	char	*actionexplanation;
776 };
777 
778 static struct togglelist Togglelist[] = {
779 	{ "autoflush",
780 	"flushing of output when sending interrupt characters",
781 	    0,
782 		&autoflush,
783 		    "flush output when sending interrupt characters" },
784 	{ "autosynch",
785 	"automatic sending of interrupt characters in urgent mode",
786 	    0,
787 		&autosynch,
788 		    "send interrupt characters in urgent mode" },
789 	{ "autologin",
790 	"automatic sending of login and/or authentication info",
791 	    0,
792 		&autologin,
793 		    "send login name and/or authentication information" },
794 	{ "authdebug",
795 	"authentication debugging",
796 	    auth_togdebug,
797 		0,
798 		    "print authentication debugging information" },
799 	{ "autoencrypt",
800 	"automatic encryption of data stream",
801 	    EncryptAutoEnc,
802 		0,
803 		    "automatically encrypt output" },
804 	{ "autodecrypt",
805 	"automatic decryption of data stream",
806 	    EncryptAutoDec,
807 		0,
808 		    "automatically decrypt input" },
809 	{ "verbose_encrypt",
810 	"verbose encryption output",
811 	    EncryptVerbose,
812 		0,
813 		    "print verbose encryption output" },
814 	{ "encdebug",
815 	"encryption debugging",
816 	    EncryptDebug,
817 		0,
818 		    "print encryption debugging information" },
819 	{ "skiprc",
820 	"don't read ~/.telnetrc file",
821 	    0,
822 		&skiprc,
823 		    "skip reading of ~/.telnetrc file" },
824 	{ "binary",
825 	"sending and receiving of binary data",
826 	    togbinary,
827 		0,
828 		    0 },
829 	{ "inbinary",
830 	"receiving of binary data",
831 	    togrbinary,
832 		0,
833 		    0 },
834 	{ "outbinary",
835 	"sending of binary data",
836 	    togxbinary,
837 		0,
838 		    0 },
839 	{ "crlf",
840 	"sending carriage returns as telnet <CR><LF>",
841 	    togcrlf,
842 		&crlf,
843 		    0 },
844 	{ "crmod",
845 	"mapping of received carriage returns",
846 	    0,
847 		&crmod,
848 		    "map carriage return on output" },
849 	{ "localchars",
850 	"local recognition of certain control characters",
851 	    lclchars,
852 		&localchars,
853 		    "recognize certain control characters" },
854 	{ " ", "", 0 },		/* empty line */
855 	{ "debug",
856 	"debugging",
857 	    togdebug,
858 		&debug,
859 		    "turn on socket level debugging" },
860 	{ "netdata",
861 	"printing of hexadecimal network data (debugging)",
862 	    0,
863 		&netdata,
864 		    "print hexadecimal representation of network traffic" },
865 	{ "prettydump",
866 	"output of \"netdata\" to user readable format (debugging)",
867 	    0,
868 		&prettydump,
869 		    "print user readable output for \"netdata\"" },
870 	{ "options",
871 	"viewing of options processing (debugging)",
872 	    0,
873 		&showoptions,
874 		    "show option processing" },
875 	{ "termdata",
876 	"(debugging) toggle printing of hexadecimal terminal data",
877 	    0,
878 		&termdata,
879 		    "print hexadecimal representation of terminal traffic" },
880 	{ "?",
881 	0,
882 	    togglehelp },
883 	{ "help",
884 	0,
885 	    togglehelp },
886 	{ 0 }
887 };
888 
889 static int
890 togglehelp()
891 {
892 	struct togglelist *c;
893 
894 	for (c = Togglelist; c->name; c++) {
895 		if (c->help) {
896 			if (*c->help)
897 				(void) printf(
898 					"%-15s toggle %s\n", c->name, c->help);
899 			else
900 				(void) printf("\n");
901 		}
902 	}
903 	(void) printf("\n");
904 	(void) printf("%-15s %s\n", "?", "display help information");
905 	return (0);
906 }
907 
908 static void
909 settogglehelp(set)
910 	int set;
911 {
912 	struct togglelist *c;
913 
914 	for (c = Togglelist; c->name; c++) {
915 		if (c->help) {
916 			if (*c->help)
917 				(void) printf("%-15s %s %s\n", c->name,
918 				    set ? "enable" : "disable", c->help);
919 			else
920 				(void) printf("\n");
921 		}
922 	}
923 }
924 
925 #define	GETTOGGLE(name) (struct togglelist *) \
926 		genget(name, (char **)Togglelist, sizeof (struct togglelist))
927 
928 static int
929 toggle(argc, argv)
930 	int  argc;
931 	char *argv[];
932 {
933 	int retval = 1;
934 	char *name;
935 	struct togglelist *c;
936 
937 	if (argc < 2) {
938 		(void) fprintf(stderr,
939 		    "Need an argument to 'toggle' command.  "
940 		    "'toggle ?' for help.\n");
941 		return (0);
942 	}
943 	argc--;
944 	argv++;
945 	while (argc--) {
946 		name = *argv++;
947 		c = GETTOGGLE(name);
948 		if (Ambiguous(c)) {
949 			(void) fprintf(stderr, "'%s': ambiguous argument "
950 			    "('toggle ?' for help).\n", name);
951 			return (0);
952 		} else if (c == 0) {
953 			(void) fprintf(stderr, "'%s': unknown argument "
954 			    "('toggle ?' for help).\n", name);
955 			return (0);
956 		} else {
957 			if (c->variable) {
958 				*c->variable = !*c->variable;	/* invert it */
959 				if (c->actionexplanation) {
960 			(void) printf("%s %s.\n",
961 				*c->variable ? "Will" : "Won't",
962 							c->actionexplanation);
963 				}
964 			}
965 			if (c->handler) {
966 				retval &= (*c->handler)(-1);
967 			}
968 		}
969 	}
970 	return (retval);
971 }
972 
973 /*
974  * The following perform the "set" command.
975  */
976 
977 #ifdef	USE_TERMIO
978 struct termio new_tc = { 0 };
979 #endif
980 
981 struct setlist {
982 	char *name;		/* name */
983 	char *help;		/* help information */
984 	void (*handler)();
985 	cc_t *charp;		/* where it is located at */
986 };
987 
988 static struct setlist Setlist[] = {
989 #ifdef	KLUDGELINEMODE
990 	{ "echo",  "character to toggle local echoing on/off", 0, &echoc },
991 #endif
992 	{ "escape", "character to escape back to telnet command mode", 0,
993 	    &escape },
994 	{ "rlogin", "rlogin escape character", 0, &rlogin },
995 	{ "tracefile", "file to write trace information to", SetNetTrace,
996 	    (cc_t *)NetTraceFile},
997 	{ " ", "" },
998 	{ " ", "The following need 'localchars' to be toggled true", 0, 0 },
999 	{ "flushoutput", "character to cause an Abort Output", 0,
1000 	    termFlushCharp },
1001 	{ "interrupt", "character to cause an Interrupt Process", 0,
1002 	    termIntCharp },
1003 	{ "quit", "character to cause an Abort process", 0, termQuitCharp },
1004 	{ "eof", "character to cause an EOF ", 0, termEofCharp },
1005 	{ " ", "" },
1006 	{ " ", "The following are for local editing in linemode", 0, 0 },
1007 	{ "erase", "character to use to erase a character", 0, termEraseCharp },
1008 	{ "kill", "character to use to erase a line", 0, termKillCharp },
1009 	{ "lnext", "character to use for literal next", 0,
1010 	    termLiteralNextCharp },
1011 	{ "susp", "character to cause a Suspend Process", 0, termSuspCharp },
1012 	{ "reprint", "character to use for line reprint", 0, termRprntCharp },
1013 	{ "worderase", "character to use to erase a word", 0, termWerasCharp },
1014 	{ "start",	"character to use for XON", 0, termStartCharp },
1015 	{ "stop",	"character to use for XOFF", 0, termStopCharp },
1016 	{ "forw1",	"alternate end of line character", 0, termForw1Charp },
1017 	{ "forw2",	"alternate end of line character", 0, termForw2Charp },
1018 	{ "ayt",	"alternate AYT character", 0, termAytCharp },
1019 	{ 0 }
1020 };
1021 
1022 static struct setlist *
1023 getset(name)
1024     char *name;
1025 {
1026 	return ((struct setlist *)
1027 	    genget(name, (char **)Setlist, sizeof (struct setlist)));
1028 }
1029 
1030     void
1031 set_escape_char(s)
1032     char *s;
1033 {
1034 	if (rlogin != _POSIX_VDISABLE) {
1035 		rlogin = (s && *s) ? special(s) : _POSIX_VDISABLE;
1036 		(void) printf("Telnet rlogin escape character is '%s'.\n",
1037 					control(rlogin));
1038 	} else {
1039 		escape = (s && *s) ? special(s) : _POSIX_VDISABLE;
1040 		(void) printf("Telnet escape character is '%s'.\n",
1041 		    esc_control(escape));
1042 	}
1043 }
1044 
1045 static int
1046 setcmd(argc, argv)
1047 	int  argc;
1048 	char *argv[];
1049 {
1050 	int value;
1051 	struct setlist *ct;
1052 	struct togglelist *c;
1053 
1054 	if (argc < 2 || argc > 3) {
1055 		(void) printf(
1056 			"Format is 'set Name Value'\n'set ?' for help.\n");
1057 		return (0);
1058 	}
1059 	if ((argc == 2) &&
1060 	    (isprefix(argv[1], "?") || isprefix(argv[1], "help"))) {
1061 		for (ct = Setlist; ct->name; ct++)
1062 			(void) printf("%-15s %s\n", ct->name, ct->help);
1063 		(void) printf("\n");
1064 		settogglehelp(1);
1065 		(void) printf("%-15s %s\n", "?", "display help information");
1066 		return (0);
1067 	}
1068 
1069 	ct = getset(argv[1]);
1070 	if (ct == 0) {
1071 		c = GETTOGGLE(argv[1]);
1072 		if (c == 0) {
1073 			(void) fprintf(stderr, "'%s': unknown argument "
1074 			    "('set ?' for help).\n", argv[1]);
1075 			return (0);
1076 		} else if (Ambiguous(c)) {
1077 			(void) fprintf(stderr, "'%s': ambiguous argument "
1078 			    "('set ?' for help).\n", argv[1]);
1079 			return (0);
1080 		}
1081 		if (c->variable) {
1082 			if ((argc == 2) || (strcmp("on", argv[2]) == 0))
1083 				*c->variable = 1;
1084 			else if (strcmp("off", argv[2]) == 0)
1085 				*c->variable = 0;
1086 			else {
1087 				(void) printf(
1088 				    "Format is 'set togglename [on|off]'\n"
1089 				    "'set ?' for help.\n");
1090 				return (0);
1091 			}
1092 			if (c->actionexplanation) {
1093 				(void) printf("%s %s.\n",
1094 				    *c->variable? "Will" : "Won't",
1095 				    c->actionexplanation);
1096 			}
1097 		}
1098 		if (c->handler)
1099 			(*c->handler)(1);
1100 	} else if (argc != 3) {
1101 		(void) printf(
1102 			"Format is 'set Name Value'\n'set ?' for help.\n");
1103 		return (0);
1104 	} else if (Ambiguous(ct)) {
1105 		(void) fprintf(stderr,
1106 		    "'%s': ambiguous argument ('set ?' for help).\n", argv[1]);
1107 		return (0);
1108 	} else if (ct->handler) {
1109 		(*ct->handler)(argv[2]);
1110 		(void) printf(
1111 		    "%s set to \"%s\".\n", ct->name, (char *)ct->charp);
1112 	} else {
1113 		if (strcmp("off", argv[2])) {
1114 			value = special(argv[2]);
1115 		} else {
1116 			value = _POSIX_VDISABLE;
1117 		}
1118 		*(ct->charp) = (cc_t)value;
1119 		(void) printf("%s character is '%s'.\n", ct->name,
1120 		    control(*(ct->charp)));
1121 	}
1122 	slc_check();
1123 	return (1);
1124 }
1125 
1126 static int
1127 unsetcmd(argc, argv)
1128 	int  argc;
1129 	char *argv[];
1130 {
1131 	struct setlist *ct;
1132 	struct togglelist *c;
1133 	register char *name;
1134 
1135 	if (argc < 2) {
1136 		(void) fprintf(stderr, "Need an argument to 'unset' command.  "
1137 		    "'unset ?' for help.\n");
1138 		return (0);
1139 	}
1140 	if (isprefix(argv[1], "?") || isprefix(argv[1], "help")) {
1141 		for (ct = Setlist; ct->name; ct++)
1142 			(void) printf("%-15s %s\n", ct->name, ct->help);
1143 		(void) printf("\n");
1144 		settogglehelp(0);
1145 		(void) printf("%-15s %s\n", "?", "display help information");
1146 		return (0);
1147 	}
1148 
1149 	argc--;
1150 	argv++;
1151 	while (argc--) {
1152 		name = *argv++;
1153 		ct = getset(name);
1154 		if (ct == 0) {
1155 			c = GETTOGGLE(name);
1156 			if (c == 0) {
1157 				(void) fprintf(stderr, "'%s': unknown argument "
1158 				    "('unset ?' for help).\n", name);
1159 				return (0);
1160 			} else if (Ambiguous(c)) {
1161 				(void) fprintf(stderr,
1162 				    "'%s': ambiguous argument "
1163 				    "('unset ?' for help).\n", name);
1164 				return (0);
1165 			}
1166 			if (c->variable) {
1167 				*c->variable = 0;
1168 				if (c->actionexplanation) {
1169 					(void) printf("%s %s.\n",
1170 					    *c->variable? "Will" : "Won't",
1171 					    c->actionexplanation);
1172 				}
1173 			}
1174 			if (c->handler)
1175 				(*c->handler)(0);
1176 		} else if (Ambiguous(ct)) {
1177 			(void) fprintf(stderr, "'%s': ambiguous argument "
1178 			    "('unset ?' for help).\n", name);
1179 			return (0);
1180 		} else if (ct->handler) {
1181 			(*ct->handler)(0);
1182 			(void) printf("%s reset to \"%s\".\n", ct->name,
1183 			    (char *)ct->charp);
1184 		} else {
1185 			*(ct->charp) = _POSIX_VDISABLE;
1186 			(void) printf("%s character is '%s'.\n", ct->name,
1187 			    control(*(ct->charp)));
1188 		}
1189 	}
1190 	return (1);
1191 }
1192 
1193 /*
1194  * The following are the data structures and routines for the
1195  * 'mode' command.
1196  */
1197 extern int reqd_linemode;
1198 
1199 #ifdef	KLUDGELINEMODE
1200 extern int kludgelinemode;
1201 
1202 static int
1203 dokludgemode()
1204 {
1205 	kludgelinemode = 1;
1206 	send_wont(TELOPT_LINEMODE, 1);
1207 	send_dont(TELOPT_SGA, 1);
1208 	send_dont(TELOPT_ECHO, 1);
1209 	/*
1210 	 * If processing the .telnetrc file, keep track of linemode and/or
1211 	 * kludgelinemode requests which are processed before initial option
1212 	 * negotiations occur.
1213 	 */
1214 	if (doing_rc)
1215 		reqd_linemode = 1;
1216 	return (1);
1217 }
1218 #endif
1219 
1220 static int
1221 dolinemode()
1222 {
1223 #ifdef	KLUDGELINEMODE
1224 	if (kludgelinemode)
1225 		send_dont(TELOPT_SGA, 1);
1226 #endif
1227 	send_will(TELOPT_LINEMODE, 1);
1228 	send_dont(TELOPT_ECHO, 1);
1229 
1230 	/*
1231 	 * If processing the .telnetrc file, keep track of linemode and/or
1232 	 * kludgelinemode requests which are processed before initial option
1233 	 * negotiations occur.
1234 	 */
1235 	if (doing_rc)
1236 		reqd_linemode = 1;
1237 	return (1);
1238 }
1239 
1240 static int
1241 docharmode()
1242 {
1243 #ifdef	KLUDGELINEMODE
1244 	if (kludgelinemode)
1245 		send_do(TELOPT_SGA, 1);
1246 	else
1247 #endif
1248 		send_wont(TELOPT_LINEMODE, 1);
1249 	send_do(TELOPT_ECHO, 1);
1250 	reqd_linemode = 0;
1251 	return (1);
1252 }
1253 
1254 static int
1255 dolmmode(bit, on)
1256 	int bit, on;
1257 {
1258 	unsigned char c;
1259 	extern int linemode;
1260 
1261 	if (my_want_state_is_wont(TELOPT_LINEMODE)) {
1262 		(void) printf("?Need to have LINEMODE option enabled first.\n");
1263 		(void) printf("'mode ?' for help.\n");
1264 		return (0);
1265 	}
1266 
1267 	if (on)
1268 		c = (linemode | bit);
1269 	else
1270 		c = (linemode & ~bit);
1271 	lm_mode(&c, 1, 1);
1272 	return (1);
1273 }
1274 
1275 static int
1276 setmode(bit)
1277 {
1278 	return (dolmmode(bit, 1));
1279 }
1280 
1281 static int
1282 clearmode(bit)
1283 {
1284 	return (dolmmode(bit, 0));
1285 }
1286 
1287 struct modelist {
1288 	char	*name;		/* command name */
1289 	char	*help;		/* help string */
1290 	int	(*handler)();	/* routine which executes command */
1291 	int	needconnect;	/* Do we need to be connected to execute? */
1292 	int	arg1;
1293 };
1294 
1295 static int modehelp();
1296 
1297 static struct modelist ModeList[] = {
1298 	{ "character", "Disable LINEMODE option",	docharmode, 1 },
1299 #ifdef	KLUDGELINEMODE
1300 	{ "",	"(or disable obsolete line-by-line mode)", 0 },
1301 #endif
1302 	{ "line",	"Enable LINEMODE option",	dolinemode, 1 },
1303 #ifdef	KLUDGELINEMODE
1304 	{ "",	"(or enable obsolete line-by-line mode)", 0 },
1305 #endif
1306 	{ "", "", 0 },
1307 	{ "",	"These require the LINEMODE option to be enabled", 0 },
1308 	{ "isig",	"Enable signal trapping", setmode, 1, MODE_TRAPSIG },
1309 	{ "+isig",	0,			setmode, 1, MODE_TRAPSIG },
1310 	{ "-isig",	"Disable signal trapping", clearmode, 1, MODE_TRAPSIG },
1311 	{ "edit",	"Enable character editing",	setmode, 1, MODE_EDIT },
1312 	{ "+edit",	0,			setmode, 1, MODE_EDIT },
1313 	{ "-edit",	"Disable character editing", clearmode, 1, MODE_EDIT },
1314 	{ "softtabs",	"Enable tab expansion",	setmode, 1, MODE_SOFT_TAB },
1315 	{ "+softtabs",	0,			setmode, 1, MODE_SOFT_TAB },
1316 	{ "-softtabs",	"Disable tab expansion",
1317 						clearmode, 1, MODE_SOFT_TAB },
1318 	{ "litecho",	"Enable literal character echo",
1319 						setmode, 1, MODE_LIT_ECHO },
1320 	{ "+litecho",	0,			setmode, 1, MODE_LIT_ECHO },
1321 	{ "-litecho",	"Disable literal character echo", clearmode, 1,
1322 		MODE_LIT_ECHO },
1323 	{ "help",	0,			modehelp, 0 },
1324 #ifdef	KLUDGELINEMODE
1325 	{ "kludgeline", 0,				dokludgemode, 1 },
1326 #endif
1327 	{ "", "", 0 },
1328 	{ "?",	"Print help information",	modehelp, 0 },
1329 	{ 0 },
1330 };
1331 
1332 
1333 static int
1334 modehelp()
1335 {
1336 	struct modelist *mt;
1337 
1338 	(void) printf("format is:  'mode Mode', where 'Mode' is one of:\n\n");
1339 	for (mt = ModeList; mt->name; mt++) {
1340 		if (mt->help) {
1341 			if (*mt->help)
1342 				(void) printf("%-15s %s\n", mt->name, mt->help);
1343 			else
1344 				(void) printf("\n");
1345 		}
1346 	}
1347 	return (0);
1348 }
1349 
1350 #define	GETMODECMD(name) (struct modelist *) \
1351 		genget(name, (char **)ModeList, sizeof (struct modelist))
1352 
1353 static int
1354 modecmd(argc, argv)
1355 	int  argc;
1356 	char *argv[];
1357 {
1358 	struct modelist *mt;
1359 
1360 	if (argc != 2) {
1361 		(void) printf("'mode' command requires an argument\n");
1362 		(void) printf("'mode ?' for help.\n");
1363 	} else if ((mt = GETMODECMD(argv[1])) == 0) {
1364 		(void) fprintf(stderr,
1365 		    "Unknown mode '%s' ('mode ?' for help).\n", argv[1]);
1366 	} else if (Ambiguous(mt)) {
1367 		(void) fprintf(stderr,
1368 		    "Ambiguous mode '%s' ('mode ?' for help).\n", argv[1]);
1369 	} else if (mt->needconnect && !connected) {
1370 		(void) printf("?Need to be connected first.\n");
1371 		(void) printf("'mode ?' for help.\n");
1372 	} else if (mt->handler) {
1373 		return (*mt->handler)(mt->arg1);
1374 	}
1375 	return (0);
1376 }
1377 
1378 /*
1379  * The following data structures and routines implement the
1380  * "display" command.
1381  */
1382 
1383 static int
1384 display(argc, argv)
1385 	int  argc;
1386 	char *argv[];
1387 {
1388 	struct togglelist *tl;
1389 	struct setlist *sl;
1390 
1391 #define	dotog(tl)	if (tl->variable && tl->actionexplanation) { \
1392 			    if (*tl->variable) { \
1393 				(void) printf("will"); \
1394 			    } else { \
1395 				(void) printf("won't"); \
1396 			    } \
1397 			    (void) printf(" %s.\n", tl->actionexplanation); \
1398 			}
1399 
1400 #define	doset(sl)   if (sl->name && *sl->name != ' ') { \
1401 			if (sl->handler == 0) \
1402 			    (void) printf("%-15s [%s]\n", sl->name, \
1403 			    control(*sl->charp)); \
1404 			else \
1405 			    (void) printf("%-15s \"%s\"\n", sl->name, \
1406 			    (char *)sl->charp); \
1407 		    }
1408 
1409 	if (argc == 1) {
1410 		for (tl = Togglelist; tl->name; tl++) {
1411 			dotog(tl);
1412 		}
1413 		(void) printf("\n");
1414 		for (sl = Setlist; sl->name; sl++) {
1415 			doset(sl);
1416 		}
1417 	} else {
1418 		int i;
1419 
1420 		for (i = 1; i < argc; i++) {
1421 			sl = getset(argv[i]);
1422 			tl = GETTOGGLE(argv[i]);
1423 			if (Ambiguous(sl) || Ambiguous(tl)) {
1424 				(void) printf(
1425 				    "?Ambiguous argument '%s'.\n", argv[i]);
1426 				return (0);
1427 			} else if (!sl && !tl) {
1428 				(void) printf(
1429 				    "?Unknown argument '%s'.\n", argv[i]);
1430 				return (0);
1431 			} else {
1432 				if (tl) {
1433 					dotog(tl);
1434 				}
1435 				if (sl) {
1436 				    doset(sl);
1437 				}
1438 			}
1439 		}
1440 	}
1441 	optionstatus();
1442 	(void) EncryptStatus();
1443 	return (1);
1444 #undef	doset
1445 #undef	dotog
1446 }
1447 
1448 /*
1449  * The following are the data structures, and many of the routines,
1450  * relating to command processing.
1451  */
1452 
1453 /*
1454  * Set the escape character.
1455  */
1456 	static int
1457 setescape(argc, argv)
1458 	int argc;
1459 	char *argv[];
1460 {
1461 	register char *arg;
1462 	char *buf = NULL;
1463 
1464 	if (argc > 2)
1465 		arg = argv[1];
1466 	else {
1467 		(void) printf("new escape character: ");
1468 		if (GetString(&buf, NULL, stdin) == NULL) {
1469 			if (!feof(stdin)) {
1470 				perror("can't set escape character");
1471 				goto setescape_exit;
1472 			}
1473 		}
1474 		arg = buf;
1475 	}
1476 	/* we place no limitations on what escape can be. */
1477 	escape = arg[0];
1478 	(void) printf("Escape character is '%s'.\n", esc_control(escape));
1479 	(void) fflush(stdout);
1480 setescape_exit:
1481 	Free(&buf);
1482 	return (1);
1483 }
1484 
1485 /*ARGSUSED*/
1486 static int
1487 togcrmod(argc, argv)
1488 	int argc;
1489 	char *argv[];
1490 {
1491 	crmod = !crmod;
1492 	(void) printf(
1493 	    "%s map carriage return on output.\n", crmod ? "Will" : "Won't");
1494 	(void) fflush(stdout);
1495 	return (1);
1496 }
1497 
1498 /*ARGSUSED*/
1499 static int
1500 suspend(argc, argv)
1501 	int argc;
1502 	char *argv[];
1503 {
1504 	setcommandmode();
1505 	{
1506 		unsigned short oldrows, oldcols, newrows, newcols;
1507 		int err;
1508 
1509 		err = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
1510 		(void) kill(0, SIGTSTP);
1511 		/*
1512 		 * If we didn't get the window size before the SUSPEND, but we
1513 		 * can get them now (?), then send the NAWS to make sure that
1514 		 * we are set up for the right window size.
1515 		 */
1516 		if (TerminalWindowSize(&newrows, &newcols) && connected &&
1517 		    (err || ((oldrows != newrows) || (oldcols != newcols)))) {
1518 			sendnaws();
1519 		}
1520 	}
1521 	/* reget parameters in case they were changed */
1522 	TerminalSaveState();
1523 	setconnmode(0);
1524 	return (1);
1525 }
1526 
1527 /*ARGSUSED*/
1528 static int
1529 shell(argc, argv)
1530 	int argc;
1531 	char *argv[];
1532 {
1533 	unsigned short oldrows, oldcols, newrows, newcols;
1534 	int err;
1535 
1536 	setcommandmode();
1537 
1538 	err = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
1539 	switch (vfork()) {
1540 	case -1:
1541 		perror("Fork failed\n");
1542 		break;
1543 
1544 	case 0:
1545 		{
1546 		/*
1547 		 * Fire up the shell in the child.
1548 		 */
1549 		register char *shellp, *shellname;
1550 
1551 		shellp = getenv("SHELL");
1552 		if (shellp == NULL)
1553 			shellp = "/bin/sh";
1554 		if ((shellname = strrchr(shellp, '/')) == 0)
1555 			shellname = shellp;
1556 		else
1557 			shellname++;
1558 		if (argc > 1)
1559 			(void) execl(shellp, shellname, "-c", argv[1], 0);
1560 		else
1561 			(void) execl(shellp, shellname, 0);
1562 		perror("Execl");
1563 		_exit(EXIT_FAILURE);
1564 		}
1565 	default:
1566 		(void) wait((int *)0);	/* Wait for the shell to complete */
1567 
1568 		if (TerminalWindowSize(&newrows, &newcols) && connected &&
1569 		(err || ((oldrows != newrows) || (oldcols != newcols)))) {
1570 			sendnaws();
1571 		}
1572 		break;
1573 	}
1574 	return (1);
1575 }
1576 
1577 static int
1578 bye(argc, argv)
1579 	int  argc;	/* Number of arguments */
1580 	char *argv[];	/* arguments */
1581 {
1582 	extern int resettermname;
1583 
1584 	if (connected) {
1585 		(void) shutdown(net, 2);
1586 		(void) printf("Connection to %.*s closed.\n", MAXHOSTNAMELEN,
1587 		    hostname);
1588 		Close(&net);
1589 		connected = 0;
1590 		resettermname = 1;
1591 		/* reset options */
1592 		(void) tninit();
1593 	}
1594 	if ((argc != 2) || (strcmp(argv[1], "fromquit") != 0)) {
1595 		longjmp(toplevel, 1);
1596 		/* NOTREACHED */
1597 	}
1598 	return (1);			/* Keep lint, etc., happy */
1599 }
1600 
1601 /*VARARGS*/
1602 int
1603 quit()
1604 {
1605 	(void) call(3, bye, "bye", "fromquit");
1606 	Exit(EXIT_SUCCESS);
1607 	/*NOTREACHED*/
1608 	return (1);
1609 }
1610 
1611 /*ARGSUSED*/
1612 static int
1613 logout(argc, argv)
1614 	int argc;
1615 	char *argv[];
1616 {
1617 	send_do(TELOPT_LOGOUT, 1);
1618 	(void) netflush();
1619 	return (1);
1620 }
1621 
1622 
1623 /*
1624  * The SLC command.
1625  */
1626 
1627 struct slclist {
1628 	char	*name;
1629 	char	*help;
1630 	void	(*handler)();
1631 	int	arg;
1632 };
1633 
1634 static void slc_help();
1635 
1636 static struct slclist SlcList[] = {
1637 	{ "export",	"Use local special character definitions",
1638 						slc_mode_export,	0 },
1639 	{ "import",	"Use remote special character definitions",
1640 						slc_mode_import,	1 },
1641 	{ "check",	"Verify remote special character definitions",
1642 						slc_mode_import,	0 },
1643 	{ "help",	0,			slc_help,		0 },
1644 	{ "?",	"Print help information",	slc_help,		0 },
1645 	{ 0 },
1646 };
1647 
1648 static void
1649 slc_help()
1650 {
1651 	struct slclist *c;
1652 
1653 	for (c = SlcList; c->name; c++) {
1654 		if (c->help) {
1655 			if (*c->help)
1656 				(void) printf("%-15s %s\n", c->name, c->help);
1657 			else
1658 				(void) printf("\n");
1659 		}
1660 	}
1661 }
1662 
1663 static struct slclist *
1664 getslc(name)
1665 	char *name;
1666 {
1667 	return ((struct slclist *)
1668 	    genget(name, (char **)SlcList, sizeof (struct slclist)));
1669 }
1670 
1671 static int
1672 slccmd(argc, argv)
1673 	int  argc;
1674 	char *argv[];
1675 {
1676 	struct slclist *c;
1677 
1678 	if (argc != 2) {
1679 		(void) fprintf(stderr,
1680 		    "Need an argument to 'slc' command.  'slc ?' for help.\n");
1681 		return (0);
1682 	}
1683 	c = getslc(argv[1]);
1684 	if (c == 0) {
1685 		(void) fprintf(stderr,
1686 		    "'%s': unknown argument ('slc ?' for help).\n",
1687 		    argv[1]);
1688 		return (0);
1689 	}
1690 	if (Ambiguous(c)) {
1691 		(void) fprintf(stderr,
1692 		    "'%s': ambiguous argument ('slc ?' for help).\n", argv[1]);
1693 		return (0);
1694 	}
1695 	(*c->handler)(c->arg);
1696 	slcstate();
1697 	return (1);
1698 }
1699 
1700 /*
1701  * The ENVIRON command.
1702  */
1703 
1704 struct envlist {
1705 	char	*name;
1706 	char	*help;
1707 	void	(*handler)();
1708 	int	narg;
1709 };
1710 
1711 static struct env_lst *env_define(unsigned char *, unsigned char *);
1712 static void env_undefine(unsigned char *);
1713 static void env_export(unsigned char *);
1714 static void env_unexport(unsigned char *);
1715 static void env_send(unsigned char *);
1716 #if defined(OLD_ENVIRON) && defined(ENV_HACK)
1717 static void env_varval(unsigned char *);
1718 #endif
1719 static void env_list(void);
1720 
1721 static void env_help(void);
1722 
1723 static struct envlist EnvList[] = {
1724 	{ "define",	"Define an environment variable",
1725 						(void (*)())env_define,	2 },
1726 	{ "undefine", "Undefine an environment variable",
1727 						env_undefine,	1 },
1728 	{ "export",	"Mark an environment variable for automatic export",
1729 						env_export,	1 },
1730 	{ "unexport", "Don't mark an environment variable for automatic export",
1731 						env_unexport,	1 },
1732 	{ "send",	"Send an environment variable", env_send,	1 },
1733 	{ "list",	"List the current environment variables",
1734 						env_list,	0 },
1735 #if defined(OLD_ENVIRON) && defined(ENV_HACK)
1736 	{ "varval", "Reverse VAR and VALUE (auto, right, wrong, status)",
1737 						env_varval,    1 },
1738 #endif
1739 	{ "help",	0,			env_help,		0 },
1740 	{ "?",	"Print help information",	env_help,		0 },
1741 	{ 0 },
1742 };
1743 
1744 static void
1745 env_help()
1746 {
1747 	struct envlist *c;
1748 
1749 	for (c = EnvList; c->name; c++) {
1750 		if (c->help) {
1751 			if (*c->help)
1752 				(void) printf("%-15s %s\n", c->name, c->help);
1753 			else
1754 				(void) printf("\n");
1755 		}
1756 	}
1757 }
1758 
1759 static struct envlist *
1760 getenvcmd(name)
1761     char *name;
1762 {
1763 	return ((struct envlist *)
1764 	    genget(name, (char **)EnvList, sizeof (struct envlist)));
1765 }
1766 
1767 static int
1768 env_cmd(argc, argv)
1769 	int  argc;
1770 	char *argv[];
1771 {
1772 	struct envlist *c;
1773 
1774 	if (argc < 2) {
1775 		(void) fprintf(stderr,
1776 		    "Need an argument to 'environ' command.  "
1777 		    "'environ ?' for help.\n");
1778 		return (0);
1779 	}
1780 	c = getenvcmd(argv[1]);
1781 	if (c == 0) {
1782 		(void) fprintf(stderr, "'%s': unknown argument "
1783 		    "('environ ?' for help).\n", argv[1]);
1784 		return (0);
1785 	}
1786 	if (Ambiguous(c)) {
1787 		(void) fprintf(stderr, "'%s': ambiguous argument "
1788 		    "('environ ?' for help).\n", argv[1]);
1789 		return (0);
1790 	}
1791 	if (c->narg + 2 != argc) {
1792 		(void) fprintf(stderr,
1793 		    "Need %s%d argument%s to 'environ %s' command.  "
1794 		    "'environ ?' for help.\n",
1795 		    c->narg + 2 < argc ? "only " : "",
1796 		    c->narg, c->narg == 1 ? "" : "s", c->name);
1797 		return (0);
1798 	}
1799 	(*c->handler)(argv[2], argv[3]);
1800 	return (1);
1801 }
1802 
1803 struct env_lst {
1804 	struct env_lst *next;	/* pointer to next structure */
1805 	struct env_lst *prev;	/* pointer to previous structure */
1806 	unsigned char *var;	/* pointer to variable name */
1807 	unsigned char *value;	/* pointer to variable value */
1808 	int export;		/* 1 -> export with default list of variables */
1809 	int welldefined;	/* A well defined variable */
1810 };
1811 
1812 static struct env_lst envlisthead;
1813 
1814 static struct env_lst *
1815 env_find(var)
1816 	unsigned char *var;
1817 {
1818 	register struct env_lst *ep;
1819 
1820 	for (ep = envlisthead.next; ep; ep = ep->next) {
1821 		if (strcmp((char *)ep->var, (char *)var) == 0)
1822 			return (ep);
1823 	}
1824 	return (NULL);
1825 }
1826 
1827 int
1828 env_init()
1829 {
1830 #ifdef	lint
1831 	char **environ = NULL;
1832 #else	/* lint */
1833 	extern char **environ;
1834 #endif	/* lint */
1835 	char **epp, *cp;
1836 	struct env_lst *ep;
1837 
1838 	for (epp = environ; *epp; epp++) {
1839 		if (cp = strchr(*epp, '=')) {
1840 			*cp = '\0';
1841 
1842 			ep = env_define((unsigned char *)*epp,
1843 					(unsigned char *)cp+1);
1844 			if (ep == NULL)
1845 				return (0);
1846 			ep->export = 0;
1847 			*cp = '=';
1848 		}
1849 	}
1850 	/*
1851 	 * Special case for DISPLAY variable.  If it is ":0.0" or
1852 	 * "unix:0.0", we have to get rid of "unix" and insert our
1853 	 * hostname.
1854 	 */
1855 	if (((ep = env_find((uchar_t *)"DISPLAY")) != NULL) &&
1856 	    ((*ep->value == ':') ||
1857 	    (strncmp((char *)ep->value, "unix:", 5) == 0))) {
1858 		char hbuf[MAXHOSTNAMELEN];
1859 		char *cp2 = strchr((char *)ep->value, ':');
1860 
1861 		if (gethostname(hbuf, MAXHOSTNAMELEN) == -1) {
1862 			perror("telnet: cannot get hostname");
1863 			return (0);
1864 		}
1865 		hbuf[MAXHOSTNAMELEN-1] = '\0';
1866 		cp = malloc(strlen(hbuf) + strlen(cp2) + 1);
1867 		if (cp == NULL) {
1868 			perror("telnet: cannot define DISPLAY variable");
1869 			return (0);
1870 		}
1871 		(void) sprintf((char *)cp, "%s%s", hbuf, cp2);
1872 		free(ep->value);
1873 		ep->value = (unsigned char *)cp;
1874 	}
1875 	/*
1876 	 * If LOGNAME is defined, but USER is not, then add
1877 	 * USER with the value from LOGNAME.  We do this because the "accepted
1878 	 * practice" is to always pass USER on the wire, but SVR4 uses
1879 	 * LOGNAME by default.
1880 	 */
1881 	if ((ep = env_find((uchar_t *)"LOGNAME")) != NULL &&
1882 		env_find((uchar_t *)"USER") == NULL) {
1883 		if (env_define((unsigned char *)"USER", ep->value) != NULL)
1884 			env_unexport((unsigned char *)"USER");
1885 	}
1886 	env_export((unsigned char *)"DISPLAY");
1887 	env_export((unsigned char *)"PRINTER");
1888 
1889 	return (1);
1890 }
1891 
1892 static struct env_lst *
1893 env_define(var, value)
1894 	unsigned char *var, *value;
1895 {
1896 	unsigned char *tmp_value;
1897 	unsigned char *tmp_var;
1898 	struct env_lst *ep;
1899 
1900 	/*
1901 	 * Allocate copies of arguments first, to make cleanup easier
1902 	 * in the case of allocation errors.
1903 	 */
1904 	tmp_var = (unsigned char *)strdup((char *)var);
1905 	if (tmp_var == NULL) {
1906 		perror("telnet: can't copy environment variable name");
1907 		return (NULL);
1908 	}
1909 
1910 	tmp_value = (unsigned char *)strdup((char *)value);
1911 	if (tmp_value == NULL) {
1912 		free(tmp_var);
1913 		perror("telnet: can't copy environment variable value");
1914 		return (NULL);
1915 	}
1916 
1917 	if (ep = env_find(var)) {
1918 		if (ep->var)
1919 			free(ep->var);
1920 		if (ep->value)
1921 			free(ep->value);
1922 	} else {
1923 		ep = malloc(sizeof (struct env_lst));
1924 		if (ep == NULL) {
1925 			perror("telnet: can't define environment variable");
1926 			free(tmp_var);
1927 			free(tmp_value);
1928 			return (NULL);
1929 		}
1930 
1931 		ep->next = envlisthead.next;
1932 		envlisthead.next = ep;
1933 		ep->prev = &envlisthead;
1934 		if (ep->next)
1935 			ep->next->prev = ep;
1936 	}
1937 	ep->welldefined = opt_welldefined((char *)var);
1938 	ep->export = 1;
1939 	ep->var = tmp_var;
1940 	ep->value = tmp_value;
1941 
1942 	return (ep);
1943 }
1944 
1945 static void
1946 env_undefine(var)
1947 	unsigned char *var;
1948 {
1949 	register struct env_lst *ep;
1950 
1951 	if (ep = env_find(var)) {
1952 		ep->prev->next = ep->next;
1953 		if (ep->next)
1954 			ep->next->prev = ep->prev;
1955 		if (ep->var)
1956 			free(ep->var);
1957 		if (ep->value)
1958 			free(ep->value);
1959 		free(ep);
1960 	}
1961 }
1962 
1963 static void
1964 env_export(var)
1965 	unsigned char *var;
1966 {
1967 	register struct env_lst *ep;
1968 
1969 	if (ep = env_find(var))
1970 		ep->export = 1;
1971 }
1972 
1973 static void
1974 env_unexport(var)
1975 	unsigned char *var;
1976 {
1977 	register struct env_lst *ep;
1978 
1979 	if (ep = env_find(var))
1980 		ep->export = 0;
1981 }
1982 
1983 static void
1984 env_send(var)
1985 	unsigned char *var;
1986 {
1987 	register struct env_lst *ep;
1988 
1989 	if (my_state_is_wont(TELOPT_NEW_ENVIRON)
1990 #ifdef	OLD_ENVIRON
1991 	    /* old style */ && my_state_is_wont(TELOPT_OLD_ENVIRON)
1992 #endif
1993 		/* no environ */) {
1994 		(void) fprintf(stderr,
1995 		    "Cannot send '%s': Telnet ENVIRON option not enabled\n",
1996 									var);
1997 		return;
1998 	}
1999 	ep = env_find(var);
2000 	if (ep == 0) {
2001 		(void) fprintf(stderr,
2002 		    "Cannot send '%s': variable not defined\n", var);
2003 		return;
2004 	}
2005 	env_opt_start_info();
2006 	env_opt_add(ep->var);
2007 	env_opt_end(0);
2008 }
2009 
2010 static void
2011 env_list()
2012 {
2013 	register struct env_lst *ep;
2014 
2015 	for (ep = envlisthead.next; ep; ep = ep->next) {
2016 		(void) printf("%c %-20s %s\n", ep->export ? '*' : ' ',
2017 					ep->var, ep->value);
2018 	}
2019 }
2020 
2021 	unsigned char *
2022 env_default(init, welldefined)
2023 	int init;
2024 {
2025 	static struct env_lst *nep = NULL;
2026 
2027 	if (init) {
2028 		/* return value is not used */
2029 		nep = &envlisthead;
2030 		return (NULL);
2031 	}
2032 	if (nep) {
2033 		while ((nep = nep->next) != NULL) {
2034 			if (nep->export && (nep->welldefined == welldefined))
2035 				return (nep->var);
2036 		}
2037 	}
2038 	return (NULL);
2039 }
2040 
2041 	unsigned char *
2042 env_getvalue(var)
2043 	unsigned char *var;
2044 {
2045 	register struct env_lst *ep;
2046 
2047 	if (ep = env_find(var))
2048 		return (ep->value);
2049 	return (NULL);
2050 }
2051 
2052 #if defined(OLD_ENVIRON) && defined(ENV_HACK)
2053 static void
2054 env_varval(what)
2055 	unsigned char *what;
2056 {
2057 	extern int old_env_var, old_env_value, env_auto;
2058 	int len = strlen((char *)what);
2059 
2060 	if (len == 0)
2061 		goto unknown;
2062 
2063 	if (strncasecmp((char *)what, "status", len) == 0) {
2064 		if (env_auto)
2065 			(void) printf("%s%s", "VAR and VALUE are/will be ",
2066 					"determined automatically\n");
2067 		if (old_env_var == OLD_ENV_VAR)
2068 			(void) printf(
2069 			    "VAR and VALUE set to correct definitions\n");
2070 		else
2071 			(void) printf(
2072 			    "VAR and VALUE definitions are reversed\n");
2073 	} else if (strncasecmp((char *)what, "auto", len) == 0) {
2074 		env_auto = 1;
2075 		old_env_var = OLD_ENV_VALUE;
2076 		old_env_value = OLD_ENV_VAR;
2077 	} else if (strncasecmp((char *)what, "right", len) == 0) {
2078 		env_auto = 0;
2079 		old_env_var = OLD_ENV_VAR;
2080 		old_env_value = OLD_ENV_VALUE;
2081 	} else if (strncasecmp((char *)what, "wrong", len) == 0) {
2082 		env_auto = 0;
2083 		old_env_var = OLD_ENV_VALUE;
2084 		old_env_value = OLD_ENV_VAR;
2085 	} else {
2086 unknown:
2087 		(void) printf(
2088 		    "Unknown \"varval\" command. (\"auto\", \"right\", "
2089 		    "\"wrong\", \"status\")\n");
2090 	}
2091 }
2092 #endif	/* OLD_ENVIRON && ENV_HACK */
2093 
2094 /*
2095  * The AUTHENTICATE command.
2096  */
2097 
2098 struct authlist {
2099 	char	*name;
2100 	char	*help;
2101 	int	(*handler)();
2102 	int	narg;
2103 };
2104 
2105 extern int auth_enable(char *);
2106 extern int auth_disable(char *);
2107 extern int auth_status(void);
2108 
2109 static int auth_help(void);
2110 
2111 static struct authlist AuthList[] = {
2112 	{ "status",
2113 	    "Display current status of authentication information",
2114 	    auth_status,	0 },
2115 	{ "disable",
2116 	    "Disable an authentication type ('auth disable ?' for more)",
2117 	    auth_disable,	1 },
2118 	{ "enable",
2119 	    "Enable an authentication type ('auth enable ?' for more)",
2120 	    auth_enable,	1 },
2121 	{ "help",	0,			auth_help,		0 },
2122 	{ "?",	"Print help information",	auth_help,		0 },
2123 	{ 0 },
2124 };
2125 
2126 static int
2127 auth_help(void)
2128 {
2129 	struct authlist *c;
2130 
2131 	for (c = AuthList; c->name; c++) {
2132 		if (c->help) {
2133 			if (*c->help)
2134 				(void) printf("%-15s %s\n", c->name, c->help);
2135 			else
2136 				(void) printf("\n");
2137 		}
2138 	}
2139 	return (0);
2140 }
2141 
2142 
2143 static int
2144 auth_cmd(argc, argv)
2145 	int  argc;
2146 	char *argv[];
2147 {
2148 	struct authlist *c;
2149 
2150 	if (argc < 2) {
2151 		(void) fprintf(stderr, "Need an argument to 'auth' "
2152 			"command.  'auth ?' for help.\n");
2153 		return (0);
2154 	}
2155 
2156 	c = (struct authlist *)
2157 		genget(argv[1], (char **)AuthList, sizeof (struct authlist));
2158 	if (c == 0) {
2159 		(void) fprintf(stderr,
2160 		    "'%s': unknown argument ('auth ?' for help).\n",
2161 		    argv[1]);
2162 		return (0);
2163 	}
2164 	if (Ambiguous(c)) {
2165 		(void) fprintf(stderr,
2166 		    "'%s': ambiguous argument ('auth ?' for help).\n", argv[1]);
2167 		return (0);
2168 	}
2169 	if (c->narg + 2 != argc) {
2170 		(void) fprintf(stderr,
2171 		    "Need %s%d argument%s to 'auth %s' command."
2172 		    " 'auth ?' for help.\n",
2173 		    c->narg + 2 < argc ? "only " : "",
2174 		    c->narg, c->narg == 1 ? "" : "s", c->name);
2175 		return (0);
2176 	}
2177 	return ((*c->handler)(argv[2], argv[3]));
2178 }
2179 
2180 /*
2181  * The FORWARD command.
2182  */
2183 
2184 extern int forward_flags;
2185 
2186 struct forwlist {
2187 	char *name;
2188 	char *help;
2189 	int (*handler)();
2190 	int f_flags;
2191 };
2192 
2193 static int forw_status(void);
2194 static int forw_set(int);
2195 static int forw_help(void);
2196 
2197 static struct forwlist ForwList[] = {
2198 	{"status",
2199 		"Display current status of credential forwarding",
2200 		forw_status, 0},
2201 	{"disable",
2202 		"Disable credential forwarding",
2203 		forw_set, 0},
2204 	{"enable",
2205 		"Enable credential forwarding",
2206 		forw_set, OPTS_FORWARD_CREDS},
2207 	{"forwardable",
2208 		"Enable credential forwarding of "
2209 				"forwardable credentials",
2210 		forw_set, OPTS_FORWARD_CREDS |	OPTS_FORWARDABLE_CREDS},
2211 	{"help",
2212 		0,
2213 		forw_help, 0},
2214 	{"?",
2215 		"Print help information",
2216 		forw_help, 0},
2217 	{0},
2218 };
2219 
2220 static int
2221 forw_status(void)
2222 {
2223 	if (forward_flags & OPTS_FORWARD_CREDS) {
2224 		if (forward_flags & OPTS_FORWARDABLE_CREDS)
2225 			(void) printf(gettext(
2226 				"Credential forwarding of "
2227 				"forwardable credentials enabled\n"));
2228 		else
2229 			(void) printf(gettext(
2230 				"Credential forwarding enabled\n"));
2231 	} else
2232 		(void) printf(gettext("Credential forwarding disabled\n"));
2233 	return (0);
2234 }
2235 
2236 static int
2237 forw_set(int f_flags)
2238 {
2239 	forward_flags = f_flags;
2240 	return (0);
2241 }
2242 
2243 static int
2244 forw_help(void)
2245 {
2246 	struct forwlist *c;
2247 
2248 	for (c = ForwList; c->name; c++) {
2249 		if (c->help) {
2250 			if (*c->help)
2251 				(void) printf("%-15s %s\r\n", c->name, c->help);
2252 			else
2253 				(void) printf("\n");
2254 		}
2255 	}
2256 	return (0);
2257 }
2258 
2259 static int
2260 forw_cmd(int argc, char *argv[])
2261 {
2262 	struct forwlist *c;
2263 
2264 	if (argc < 2) {
2265 		(void) fprintf(stderr, gettext(
2266 			"Need an argument to 'forward' "
2267 			"command.  'forward ?' for help.\n"));
2268 		return (0);
2269 	}
2270 	c = (struct forwlist *)genget(argv[1], (char **)ForwList,
2271 		sizeof (struct forwlist));
2272 	if (c == 0) {
2273 		(void) fprintf(stderr, gettext(
2274 		    "'%s': unknown argument ('forward ?' for help).\n"),
2275 		    argv[1]);
2276 		return (0);
2277 	}
2278 	if (Ambiguous(c)) {
2279 		(void) fprintf(stderr, gettext(
2280 		    "'%s': ambiguous argument ('forward ?' for help).\n"),
2281 		    argv[1]);
2282 		return (0);
2283 	}
2284 	if (argc != 2) {
2285 		(void) fprintf(stderr, gettext(
2286 		    "No arguments needed to 'forward %s' command.  "
2287 		    "'forward ?' for help.\n"), c->name);
2288 		return (0);
2289 	}
2290 	return ((*c->handler) (c->f_flags));
2291 }
2292 
2293 /*
2294  * The ENCRYPT command.
2295  */
2296 
2297 struct encryptlist {
2298 	char	*name;
2299 	char	*help;
2300 	int	(*handler)();
2301 	int	needconnect;
2302 	int	minarg;
2303 	int	maxarg;
2304 };
2305 
2306 static int EncryptHelp(void);
2307 
2308 static struct encryptlist EncryptList[] = {
2309 	{ "enable", "Enable encryption. ('encrypt enable ?' for more)",
2310 						EncryptEnable, 1, 1, 2 },
2311 	{ "disable", "Disable encryption. ('encrypt disable ?' for more)",
2312 						EncryptDisable, 0, 1, 2 },
2313 	{ "type", "Set encryption type. ('encrypt type ?' for more)",
2314 						EncryptType, 0, 1, 2 },
2315 	{ "start", "Start encryption. ('encrypt start ?' for more)",
2316 						EncryptStart, 1, 0, 1 },
2317 	{ "stop", "Stop encryption. ('encrypt stop ?' for more)",
2318 						EncryptStop, 1, 0, 1 },
2319 	{ "input", "Start encrypting the input stream",
2320 						EncryptStartInput, 1, 0, 0 },
2321 	{ "-input", "Stop encrypting the input stream",
2322 						EncryptStopInput, 1, 0, 0 },
2323 	{ "output", "Start encrypting the output stream",
2324 						EncryptStartOutput, 1, 0, 0 },
2325 	{ "-output", "Stop encrypting the output stream",
2326 						EncryptStopOutput, 1, 0, 0 },
2327 
2328 	{ "status",	"Display current status of encryption information",
2329 						EncryptStatus,	0, 0, 0 },
2330 	{ "help",	0,
2331 						EncryptHelp,	0, 0, 0 },
2332 	{ "?",	"Print help information",	EncryptHelp,	0, 0, 0 },
2333 	{ 0 },
2334 };
2335 
2336 static int
2337 EncryptHelp(void)
2338 {
2339 	struct encryptlist *c;
2340 
2341 	for (c = EncryptList; c->name; c++) {
2342 		if (c->help) {
2343 			if (*c->help)
2344 				(void) printf("%-15s %s\n", c->name, c->help);
2345 			else
2346 				(void) printf("\n");
2347 		}
2348 	}
2349 	return (0);
2350 }
2351 
2352 static int
2353 encrypt_cmd(int  argc, char *argv[])
2354 {
2355 	struct encryptlist *c;
2356 
2357 	if (argc < 2) {
2358 		(void) fprintf(stderr, gettext(
2359 			"Need an argument to 'encrypt' command.  "
2360 			"'encrypt ?' for help.\n"));
2361 		return (0);
2362 	}
2363 
2364 	c = (struct encryptlist *)
2365 	    genget(argv[1], (char **)EncryptList, sizeof (struct encryptlist));
2366 	if (c == 0) {
2367 		(void) fprintf(stderr, gettext(
2368 		    "'%s': unknown argument ('encrypt ?' for help).\n"),
2369 		    argv[1]);
2370 		return (0);
2371 	}
2372 	if (Ambiguous(c)) {
2373 		(void) fprintf(stderr, gettext(
2374 		    "'%s': ambiguous argument ('encrypt ?' for help).\n"),
2375 		    argv[1]);
2376 		return (0);
2377 	}
2378 	argc -= 2;
2379 	if (argc < c->minarg || argc > c->maxarg) {
2380 		if (c->minarg == c->maxarg) {
2381 			(void) fprintf(stderr, gettext("Need %s%d %s "),
2382 			c->minarg < argc ?
2383 			gettext("only ") : "", c->minarg,
2384 			c->minarg == 1 ?
2385 			gettext("argument") : gettext("arguments"));
2386 		} else {
2387 			(void) fprintf(stderr,
2388 			    gettext("Need %s%d-%d arguments "),
2389 			c->maxarg < argc ?
2390 			gettext("only ") : "", c->minarg, c->maxarg);
2391 		}
2392 		(void) fprintf(stderr, gettext(
2393 		    "to 'encrypt %s' command.  'encrypt ?' for help.\n"),
2394 		    c->name);
2395 		return (0);
2396 	}
2397 	if (c->needconnect && !connected) {
2398 		if (!(argc &&
2399 		    (isprefix(argv[2], "help") || isprefix(argv[2], "?")))) {
2400 			(void) printf(
2401 			    gettext("?Need to be connected first.\n"));
2402 			return (0);
2403 		}
2404 	}
2405 	return ((*c->handler)(argc > 0 ? argv[2] : 0,
2406 	    argc > 1 ? argv[3] : 0, argc > 2 ? argv[4] : 0));
2407 }
2408 
2409 /*
2410  * Print status about the connection.
2411  */
2412 static int
2413 status(int argc, char *argv[])
2414 {
2415 	if (connected) {
2416 		(void) printf("Connected to %s.\n", hostname);
2417 		if ((argc < 2) || strcmp(argv[1], "notmuch")) {
2418 			int mode = getconnmode();
2419 
2420 			if (my_want_state_is_will(TELOPT_LINEMODE)) {
2421 				(void) printf(
2422 				    "Operating with LINEMODE option\n");
2423 				(void) printf(
2424 				    "%s line editing\n", (mode&MODE_EDIT) ?
2425 				    "Local" : "No");
2426 				(void) printf("%s catching of signals\n",
2427 				    (mode&MODE_TRAPSIG) ? "Local" : "No");
2428 				slcstate();
2429 #ifdef	KLUDGELINEMODE
2430 			} else if (kludgelinemode &&
2431 			    my_want_state_is_dont(TELOPT_SGA)) {
2432 				(void) printf(
2433 				    "Operating in obsolete linemode\n");
2434 #endif
2435 			} else {
2436 				(void) printf(
2437 					"Operating in single character mode\n");
2438 				if (localchars)
2439 					(void) printf(
2440 					"Catching signals locally\n");
2441 			}
2442 			(void) printf("%s character echo\n", (mode&MODE_ECHO) ?
2443 			    "Local" : "Remote");
2444 			if (my_want_state_is_will(TELOPT_LFLOW))
2445 				(void) printf("%s flow control\n",
2446 				    (mode&MODE_FLOW) ? "Local" : "No");
2447 
2448 				encrypt_display();
2449 		}
2450 	} else {
2451 		(void) printf("No connection.\n");
2452 	}
2453 	if (rlogin != _POSIX_VDISABLE)
2454 		(void) printf("Escape character is '%s'.\n", control(rlogin));
2455 	else
2456 		(void) printf(
2457 		    "Escape character is '%s'.\n", esc_control(escape));
2458 	(void) fflush(stdout);
2459 	return (1);
2460 }
2461 
2462 /*
2463  * Parse the user input (cmd_line_input) which should:
2464  * - start with the target host, or with "@" or "!@" followed by at least one
2465  *   gateway.
2466  * - each host (can be literal address or hostname) can be separated by ",",
2467  *   "@", or ",@".
2468  * Note that the last host is the target, all the others (if any ) are the
2469  * gateways.
2470  *
2471  * Returns:	-1	if a library call fails, too many gateways, or parse
2472  *			error
2473  *		num_gw	otherwise
2474  * On successful return, hostname_list points to a list of hosts (last one being
2475  * the target, others gateways), src_rtng_type points to the type of source
2476  * routing (strict vs. loose)
2477  */
2478 static int
2479 parse_input(char *cmd_line_input, char **hostname_list, uchar_t *src_rtng_type)
2480 {
2481 	char hname[MAXHOSTNAMELEN + 1];
2482 	char *cp;
2483 	int gw_count;
2484 	int i;
2485 
2486 	gw_count = 0;
2487 	cp = cmd_line_input;
2488 
2489 	/*
2490 	 * Defining ICMD generates the Itelnet binary, the special version of
2491 	 * telnet which is used with firewall proxy.
2492 	 * If ICMD is defined, parse_input will treat the whole cmd_line_input
2493 	 * as the target host and set the num_gw to 0. Therefore, none of the
2494 	 * source routing related code paths will be executed.
2495 	 */
2496 #ifndef ICMD
2497 	if (*cp == '@') {
2498 		*src_rtng_type = IPOPT_LSRR;
2499 		cp++;
2500 	} else if (*cp == '!') {
2501 		*src_rtng_type = IPOPT_SSRR;
2502 
2503 		/* "!" must be followed by '@' */
2504 		if (*(cp + 1) != '@')
2505 			goto parse_error;
2506 		cp += 2;
2507 	} else {
2508 #endif	/* ICMD */
2509 		/* no gateways, just the target */
2510 		hostname_list[0] = strdup(cp);
2511 		if (hostname_list[0] == NULL) {
2512 			perror("telnet: copying host name");
2513 			return (-1);
2514 		}
2515 		return (0);
2516 #ifndef ICMD
2517 	}
2518 
2519 	while (*cp != '\0') {
2520 		/*
2521 		 * Identify each gateway separated by ",", "@" or ",@" and
2522 		 * store in hname[].
2523 		 */
2524 		i = 0;
2525 		while (*cp != '@' && *cp != ',' && *cp != '\0') {
2526 			hname[i++] = *cp++;
2527 			if (i > MAXHOSTNAMELEN)
2528 				goto parse_error;
2529 		}
2530 		hname[i] = '\0';
2531 
2532 		/*
2533 		 * Two consecutive delimiters which result in a 0 length hname
2534 		 * is a parse error.
2535 		 */
2536 		if (i == 0)
2537 			goto parse_error;
2538 
2539 		hostname_list[gw_count] = strdup(hname);
2540 		if (hostname_list[gw_count] == NULL) {
2541 			perror("telnet: copying hostname from list");
2542 			return (-1);
2543 		}
2544 
2545 		if (++gw_count > MAXMAX_GATEWAY) {
2546 			(void) fprintf(stderr, "telnet: too many gateways\n");
2547 			return (-1);
2548 		}
2549 
2550 		/* Jump over the next delimiter. */
2551 		if (*cp != '\0') {
2552 			/* ...gw1,@gw2... accepted */
2553 			if (*cp == ',' && *(cp + 1) == '@')
2554 				cp += 2;
2555 			else
2556 				cp++;
2557 		}
2558 	}
2559 
2560 	/* discount the target */
2561 	gw_count--;
2562 
2563 	/* Any input starting with '!@' or '@' must have at least one gateway */
2564 	if (gw_count <= 0)
2565 		goto parse_error;
2566 
2567 	return (gw_count);
2568 
2569 parse_error:
2570 	(void) printf("Bad source route option: %s\n", cmd_line_input);
2571 	return (-1);
2572 #endif	/* ICMD */
2573 }
2574 
2575 /*
2576  * Resolves the target and gateway addresses, determines what type of addresses
2577  * (ALL_ADDRS, ONLY_V6, ONLY_V4) telnet will be trying to connect.
2578  *
2579  * Returns:	pointer to resolved target	if name resolutions succeed
2580  *		NULL				if name resolutions fail or
2581  *						a library function call fails
2582  *
2583  * The last host in the hostname_list is the target. After resolving the target,
2584  * determines for what type of addresses it should try to resolve gateways. It
2585  * resolves gateway addresses and picks one address for each desired address
2586  * type and stores in the array pointed by gw_addrsp. Also, this 'type of
2587  * addresses' is pointed by addr_type argument on successful return.
2588  */
2589 static struct addrinfo *
2590 resolve_hosts(char **hostname_list, int num_gw, struct gateway **gw_addrsp,
2591     int *addr_type, const char *portp)
2592 {
2593 	struct gateway *gw_addrs = NULL;
2594 	struct gateway *gw;
2595 	/* whether we already picked an IPv4 address for the current gateway */
2596 	boolean_t got_v4_addr;
2597 	boolean_t got_v6_addr;
2598 	/* whether we need to get an IPv4 address for the current gateway */
2599 	boolean_t need_v4_addr = B_FALSE;
2600 	boolean_t need_v6_addr = B_FALSE;
2601 	int res_failed_at4;	/* save which gateway failed to resolve */
2602 	int res_failed_at6;
2603 	boolean_t is_v4mapped;
2604 	struct in6_addr *v6addrp;
2605 	struct in_addr *v4addrp;
2606 	int error_num;
2607 	int i;
2608 	int rc;
2609 	struct addrinfo *res, *host, *gateway, *addr;
2610 	struct addrinfo hints;
2611 
2612 	*addr_type = ALL_ADDRS;
2613 
2614 	memset(&hints, 0, sizeof (hints));
2615 	hints.ai_flags = AI_CANONNAME; /* used for config files, diags */
2616 	hints.ai_socktype = SOCK_STREAM;
2617 	rc = getaddrinfo(hostname_list[num_gw],
2618 	    (portp != NULL) ? portp : "telnet", &hints, &res);
2619 	if (rc != 0) {
2620 		if (hostname_list[num_gw] != NULL &&
2621 		    *hostname_list[num_gw] != '\0')
2622 			(void) fprintf(stderr, "%s: ", hostname_list[num_gw]);
2623 		(void) fprintf(stderr, "%s\n", gai_strerror(rc));
2624 		return (NULL);
2625 	}
2626 
2627 	/*
2628 	 * Let's see what type of addresses we got for the target. This
2629 	 * determines what type of addresses we'd like to resolve gateways
2630 	 * later.
2631 	 */
2632 	for (host = res; host != NULL; host = host->ai_next) {
2633 		struct sockaddr_in6 *s6;
2634 
2635 		s6 = (struct sockaddr_in6 *)host->ai_addr;
2636 
2637 		if (host->ai_addr->sa_family == AF_INET ||
2638 		    IN6_IS_ADDR_V4MAPPED(&s6->sin6_addr))
2639 			need_v4_addr = B_TRUE;
2640 		else
2641 			need_v6_addr = B_TRUE;
2642 
2643 		/*
2644 		 * Let's stop after seeing we need both IPv6 and IPv4.
2645 		 */
2646 		if (need_v4_addr && need_v6_addr)
2647 			break;
2648 	}
2649 
2650 	if (num_gw > 0) {
2651 		/*
2652 		 * In the prepare_optbuf(), we'll store the IPv4 address of the
2653 		 * target in the last slot of gw_addrs array. Therefore we need
2654 		 * space for num_gw+1 hosts.
2655 		 */
2656 		gw_addrs = calloc(num_gw + 1, sizeof (struct gateway));
2657 		if (gw_addrs == NULL) {
2658 			perror("telnet: calloc");
2659 			freeaddrinfo(res);
2660 			return (NULL);
2661 		}
2662 	}
2663 
2664 	/*
2665 	 * Now we'll go through all the gateways and try to resolve them to
2666 	 * the desired address types.
2667 	 */
2668 	gw = gw_addrs;
2669 
2670 	/* -1 means 'no address resolution failure yet' */
2671 	res_failed_at4 = -1;
2672 	res_failed_at6 = -1;
2673 	for (i = 0; i < num_gw; i++) {
2674 		rc = getaddrinfo(hostname_list[i], NULL, NULL, &gateway);
2675 		if (rc != 0) {
2676 			if (hostname_list[i] != NULL &&
2677 			    *hostname_list[i] != '\0')
2678 				(void) fprintf(stderr, "%s: ",
2679 				    hostname_list[i]);
2680 			(void) fprintf(stderr, "bad address\n");
2681 			return (NULL);
2682 		}
2683 
2684 		/*
2685 		 * Initially we have no address of any type for this gateway.
2686 		 */
2687 		got_v6_addr = B_FALSE;
2688 		got_v4_addr = B_FALSE;
2689 
2690 		/*
2691 		 * Let's go through all the addresses of this gateway.
2692 		 * Use the first address which matches the needed family.
2693 		 */
2694 		for (addr = gateway; addr != NULL; addr = addr->ai_next) {
2695 			/*LINTED*/
2696 			v6addrp = &((struct sockaddr_in6 *)addr->ai_addr)->
2697 			    sin6_addr;
2698 			v4addrp = &((struct sockaddr_in *)addr->ai_addr)->
2699 			    sin_addr;
2700 
2701 			if (addr->ai_family == AF_INET6)
2702 				is_v4mapped = IN6_IS_ADDR_V4MAPPED(v6addrp);
2703 			else
2704 				is_v4mapped = B_FALSE;
2705 
2706 			/*
2707 			 * If we need to determine an IPv4 address and haven't
2708 			 * found one yet and this is a IPv4-mapped IPv6 address,
2709 			 * then bingo!
2710 			 */
2711 			if (need_v4_addr && !got_v4_addr) {
2712 				if (is_v4mapped) {
2713 					IN6_V4MAPPED_TO_INADDR(v6addrp,
2714 					    &gw->gw_addr);
2715 					got_v4_addr = B_TRUE;
2716 				} else if (addr->ai_family = AF_INET) {
2717 					gw->gw_addr = *v4addrp;
2718 					got_v4_addr = B_TRUE;
2719 				}
2720 			}
2721 
2722 			if (need_v6_addr && !got_v6_addr &&
2723 			    addr->ai_family == AF_INET6) {
2724 				gw->gw_addr6 = *v6addrp;
2725 				got_v6_addr = B_TRUE;
2726 			}
2727 
2728 			/*
2729 			 * Let's stop if we got all what we looked for.
2730 			 */
2731 			if ((!need_v4_addr || got_v4_addr) &&
2732 			    (!need_v6_addr || got_v6_addr))
2733 				break;
2734 		}
2735 
2736 		/*
2737 		 * We needed an IPv4 address for this gateway but couldn't
2738 		 * find one.
2739 		 */
2740 		if (need_v4_addr && !got_v4_addr) {
2741 			res_failed_at4 = i;
2742 			/*
2743 			 * Since we couldn't resolve a gateway to IPv4 address
2744 			 * we can't use IPv4 at all. Therefore we no longer
2745 			 * need IPv4 addresses for any of the gateways.
2746 			 */
2747 			need_v4_addr = B_FALSE;
2748 		}
2749 
2750 		if (need_v6_addr && !got_v6_addr) {
2751 			res_failed_at6 = i;
2752 			need_v6_addr = B_FALSE;
2753 		}
2754 
2755 		/*
2756 		 * If some gateways don't resolve to any of the desired
2757 		 * address types, we fail.
2758 		 */
2759 		if (!need_v4_addr && !need_v6_addr) {
2760 			if (res_failed_at6 != -1) {
2761 				(void) fprintf(stderr,
2762 				    "%s: Host doesn't have any IPv6 address\n",
2763 				    hostname_list[res_failed_at6]);
2764 			}
2765 			if (res_failed_at4 != -1) {
2766 				(void) fprintf(stderr,
2767 				    "%s: Host doesn't have any IPv4 address\n",
2768 				    hostname_list[res_failed_at4]);
2769 			}
2770 			free(gw_addrs);
2771 			return (NULL);
2772 		}
2773 
2774 		gw++;
2775 	}
2776 
2777 	*gw_addrsp = gw_addrs;
2778 
2779 	/*
2780 	 * When we get here, need_v4_addr and need_v6_addr have their final
2781 	 * values based on the name resolution of the target and gateways.
2782 	 */
2783 	if (need_v4_addr && need_v6_addr)
2784 		*addr_type = ALL_ADDRS;
2785 	else if (need_v4_addr && !need_v6_addr)
2786 		*addr_type = ONLY_V4;
2787 	else if (!need_v4_addr && need_v6_addr)
2788 		*addr_type = ONLY_V6;
2789 
2790 	return (res);
2791 }
2792 
2793 
2794 /*
2795  * Initializes the buffer pointed by opt_bufpp for a IPv4 option of type
2796  * src_rtng_type using the gateway addresses stored in gw_addrs. If no buffer
2797  * is passed, it allocates one. If a buffer is passed, checks if it's big
2798  * enough.
2799  * On return opt_buf_len points to the buffer length which we need later for the
2800  * setsockopt() call, and opt_bufpp points to the newly allocated or already
2801  * passed buffer. Returns B_FALSE if a library function call fails or passed
2802  * buffer is not big enough, B_TRUE otherwise.
2803  */
2804 static boolean_t
2805 prepare_optbuf(struct gateway *gw_addrs, int num_gw, char **opt_bufpp,
2806     size_t *opt_buf_len, struct in_addr *target, uchar_t src_rtng_type)
2807 {
2808 	struct ip_sourceroute *sr_opt;
2809 	size_t needed_buflen;
2810 	int i;
2811 
2812 	/*
2813 	 * We have (num_gw + 1) IP addresses in the buffer because the number
2814 	 * of gateway addresses we put in the option buffer includes the target
2815 	 * address.
2816 	 * At the time of setsockopt() call, passed option length needs to be
2817 	 * multiple of 4 bytes. Therefore we need one IPOPT_NOP before (or
2818 	 * after) IPOPT_LSRR.
2819 	 * 1 = preceding 1 byte of IPOPT_NOP
2820 	 * 3 = 1 (code) + 1 (len) + 1 (ptr)
2821 	 */
2822 	needed_buflen = 1 + 3 + (num_gw + 1) * sizeof (struct in_addr);
2823 
2824 	if (*opt_bufpp != NULL) {
2825 		/* check if the passed buffer is big enough */
2826 		if (*opt_buf_len < needed_buflen) {
2827 			(void) fprintf(stderr,
2828 			    "telnet: buffer too small for IPv4 source routing "
2829 			    "option\n");
2830 			return (B_FALSE);
2831 		}
2832 	} else {
2833 		*opt_bufpp = malloc(needed_buflen);
2834 		if (*opt_bufpp == NULL) {
2835 			perror("telnet: malloc");
2836 			return (B_FALSE);
2837 		}
2838 	}
2839 
2840 	*opt_buf_len = needed_buflen;
2841 
2842 	/* final hop is the target */
2843 	gw_addrs[num_gw].gw_addr = *target;
2844 
2845 	*opt_bufpp[0] = IPOPT_NOP;
2846 	/* IPOPT_LSRR starts right after IPOPT_NOP */
2847 	sr_opt = (struct ip_sourceroute *)(*opt_bufpp + 1);
2848 	sr_opt->ipsr_code = src_rtng_type;
2849 	/* discount the 1 byte of IPOPT_NOP */
2850 	sr_opt->ipsr_len = needed_buflen - 1;
2851 	sr_opt->ipsr_ptr = IPOPT_MINOFF;
2852 
2853 	/* copy the gateways into the optlist */
2854 	for (i = 0; i < num_gw + 1; i++) {
2855 		(void) bcopy(&gw_addrs[i].gw_addr, &sr_opt->ipsr_addrs[i],
2856 		    sizeof (struct in_addr));
2857 	}
2858 
2859 	return (B_TRUE);
2860 }
2861 
2862 /*
2863  * Initializes the buffer pointed by opt_bufpp for a IPv6 routing header option
2864  * using the gateway addresses stored in gw_addrs. If no buffer is passed, it
2865  * allocates one. If a buffer is passed, checks if it's big enough.
2866  * On return opt_buf_len points to the buffer length which we need later for the
2867  * setsockopt() call, and opt_bufpp points to the newly allocated or already
2868  * passed buffer. Returns B_FALSE if a library function call fails or passed
2869  * buffer is not big enough, B_TRUE otherwise.
2870  */
2871 static boolean_t
2872 prepare_optbuf6(struct gateway *gw_addrs, int num_gw, char **opt_bufpp,
2873     size_t *opt_buf_len)
2874 {
2875 	char *opt_bufp;
2876 	size_t needed_buflen;
2877 	int i;
2878 
2879 	needed_buflen = inet6_rth_space(IPV6_RTHDR_TYPE_0, num_gw);
2880 
2881 	if (*opt_bufpp != NULL) {
2882 		/* check if the passed buffer is big enough */
2883 		if (*opt_buf_len < needed_buflen) {
2884 			(void) fprintf(stderr,
2885 			    "telnet: buffer too small for IPv6 routing "
2886 			    "header option\n");
2887 			return (B_FALSE);
2888 		}
2889 	} else {
2890 		*opt_bufpp = malloc(needed_buflen);
2891 		if (*opt_bufpp == NULL) {
2892 			perror("telnet: malloc");
2893 			return (B_FALSE);
2894 		}
2895 	}
2896 	*opt_buf_len = needed_buflen;
2897 	opt_bufp = *opt_bufpp;
2898 
2899 	/*
2900 	 * Initialize the buffer to be used for IPv6 routing header type 0.
2901 	 */
2902 	if (inet6_rth_init(opt_bufp, needed_buflen, IPV6_RTHDR_TYPE_0,
2903 	    num_gw) == NULL) {
2904 		perror("telnet: inet6_rth_init");
2905 		return (B_FALSE);
2906 	}
2907 
2908 	/*
2909 	 * Add gateways one by one.
2910 	 */
2911 	for (i = 0; i < num_gw; i++) {
2912 		if (inet6_rth_add(opt_bufp, &gw_addrs[i].gw_addr6) == -1) {
2913 			perror("telnet: inet6_rth_add");
2914 			return (B_FALSE);
2915 		}
2916 	}
2917 
2918 	/* successful operation */
2919 	return (B_TRUE);
2920 }
2921 
2922 int
2923 tn(argc, argv)
2924 	int argc;
2925 	char *argv[];
2926 {
2927 	struct addrinfo *host = NULL;
2928 	struct addrinfo *h;
2929 	struct sockaddr_in6 sin6;
2930 	struct sockaddr_in sin;
2931 	struct in6_addr addr6;
2932 	struct in_addr addr;
2933 	void *addrp;
2934 	struct gateway *gw_addrs;
2935 	char *hostname_list[MAXMAX_GATEWAY + 1] = {NULL};
2936 	char *opt_buf6 = NULL;		/* used for IPv6 routing header */
2937 	size_t opt_buf_len6 = 0;
2938 	uchar_t src_rtng_type;		/* type of IPv4 source routing */
2939 	struct servent *sp = 0;
2940 	char *opt_buf = NULL;		/* used for IPv4 source routing */
2941 	size_t opt_buf_len = 0;
2942 	char *cmd;
2943 	char *hostp = NULL;
2944 	char *portp = NULL;
2945 	char *user = NULL;
2946 #ifdef	ICMD
2947 	char *itelnet_host;
2948 	char *real_host;
2949 	unsigned short dest_port;
2950 #endif	/* ICMD */
2951 	/*
2952 	 * The two strings at the end of this function are 24 and 39
2953 	 * characters long (minus the %.*s in the format strings).  Add
2954 	 * one for the null terminator making the longest print string 40.
2955 	 */
2956 	char buf[MAXHOSTNAMELEN+40];
2957 	/*
2958 	 * In the case of ICMD defined, dest_port will contain the real port
2959 	 * we are trying to telnet to, and target_port will contain
2960 	 * "telnet-passthru" port.
2961 	 */
2962 	unsigned short target_port;
2963 	char abuf[INET6_ADDRSTRLEN];
2964 	int num_gw;
2965 	int ret_val;
2966 	boolean_t is_v4mapped;
2967 	/*
2968 	 * Type of addresses we'll try to connect to (ALL_ADDRS, ONLY_V6,
2969 	 * ONLY_V4).
2970 	 */
2971 	int addr_type;
2972 
2973 	/* clear the socket address prior to use */
2974 	(void) memset(&sin6, '\0', sizeof (sin6));
2975 	sin6.sin6_family = AF_INET6;
2976 
2977 	(void) memset(&sin, '\0', sizeof (sin));
2978 	sin.sin_family = AF_INET;
2979 
2980 	if (connected) {
2981 		(void) printf("?Already connected to %s\n", hostname);
2982 		return (0);
2983 	}
2984 #ifdef	ICMD
2985 	itelnet_host = getenv("INTERNET_HOST");
2986 	if (itelnet_host == NULL || itelnet_host[0] == '\0') {
2987 		(void) printf("INTERNET_HOST environment variable undefined\n");
2988 		goto tn_exit;
2989 	}
2990 #endif
2991 	if (argc < 2) {
2992 		(void) printf("(to) ");
2993 		if (GetAndAppendString(&line, &linesize, "open ",
2994 			stdin) == NULL) {
2995 			if (!feof(stdin)) {
2996 				perror("telnet");
2997 				goto tn_exit;
2998 			}
2999 		}
3000 		makeargv();
3001 		argc = margc;
3002 		argv = margv;
3003 	}
3004 	cmd = *argv;
3005 	--argc; ++argv;
3006 	while (argc) {
3007 		if (isprefix(*argv, "help") == 4 || isprefix(*argv, "?") == 1)
3008 			goto usage;
3009 		if (strcmp(*argv, "-l") == 0) {
3010 			--argc; ++argv;
3011 			if (argc == 0)
3012 				goto usage;
3013 			user = *argv++;
3014 			--argc;
3015 			continue;
3016 		}
3017 		if (strcmp(*argv, "-a") == 0) {
3018 			--argc; ++argv;
3019 			autologin = autologin_set = 1;
3020 			continue;
3021 		}
3022 		if (hostp == 0) {
3023 			hostp = *argv++;
3024 			--argc;
3025 			continue;
3026 		}
3027 		if (portp == 0) {
3028 			portp = *argv++;
3029 			--argc;
3030 			/*
3031 			 * Do we treat this like a telnet port or raw?
3032 			 */
3033 			if (*portp == '-') {
3034 				portp++;
3035 				telnetport = 1;
3036 			} else
3037 				telnetport = 0;
3038 			continue;
3039 		}
3040 usage:
3041 		(void) printf(
3042 		    "usage: %s [-l user] [-a] host-name [port]\n", cmd);
3043 		goto tn_exit;
3044 	}
3045 	if (hostp == 0)
3046 		goto usage;
3047 
3048 #ifdef ICMD
3049 	/*
3050 	 * For setup phase treat the relay host as the target host.
3051 	 */
3052 	real_host = hostp;
3053 	hostp = itelnet_host;
3054 #endif
3055 	num_gw = parse_input(hostp, hostname_list, &src_rtng_type);
3056 	if (num_gw < 0) {
3057 		goto tn_exit;
3058 	}
3059 
3060 	/* Last host in the hostname_list is the target */
3061 	hostp = hostname_list[num_gw];
3062 
3063 	host = resolve_hosts(hostname_list, num_gw, &gw_addrs, &addr_type,
3064 	    portp);
3065 	if (host == NULL) {
3066 		goto tn_exit;
3067 	}
3068 
3069 	/*
3070 	 * Check if number of gateways is less than max. available
3071 	 */
3072 	if ((addr_type == ALL_ADDRS || addr_type == ONLY_V6) &&
3073 	    num_gw > MAX_GATEWAY6) {
3074 		(void) fprintf(stderr, "telnet: too many IPv6 gateways\n");
3075 		goto tn_exit;
3076 	}
3077 
3078 	if ((addr_type == ALL_ADDRS || addr_type == ONLY_V4) &&
3079 	    num_gw > MAX_GATEWAY) {
3080 		(void) fprintf(stderr, "telnet: too many IPv4 gateways\n");
3081 		goto tn_exit;
3082 	}
3083 
3084 	/*
3085 	 * If we pass a literal IPv4 address to getaddrinfo(), in the
3086 	 * returned addrinfo structure, hostname is the IPv4-mapped IPv6
3087 	 * address string. We prefer to preserve the literal IPv4 address
3088 	 * string as the hostname.  Also, if the hostname entered by the
3089 	 * user is IPv4-mapped IPv6 address, we'll downgrade it to IPv4
3090 	 * address.
3091 	 */
3092 	if (inet_addr(hostp) != (in_addr_t)-1) {
3093 		/* this is a literal IPv4 address */
3094 		(void) strlcpy(_hostname, hostp, sizeof (_hostname));
3095 	} else if ((inet_pton(AF_INET6, hostp, &addr6) > 0) &&
3096 		    IN6_IS_ADDR_V4MAPPED(&addr6)) {
3097 		/* this is a IPv4-mapped IPv6 address */
3098 		IN6_V4MAPPED_TO_INADDR(&addr6, &addr);
3099 		(void) inet_ntop(AF_INET, &addr, _hostname, sizeof (_hostname));
3100 	} else {
3101 		(void) strlcpy(_hostname, host->ai_canonname,
3102 		    sizeof (_hostname));
3103 	}
3104 	hostname = _hostname;
3105 
3106 	if (portp == NULL) {
3107 		telnetport = 1;
3108 	}
3109 
3110 	if (host->ai_family == AF_INET) {
3111 		target_port = ((struct sockaddr_in *)(host->ai_addr))->sin_port;
3112 	} else {
3113 		target_port = ((struct sockaddr_in6 *)(host->ai_addr))
3114 		    ->sin6_port;
3115 	}
3116 
3117 #ifdef ICMD
3118 	/*
3119 	 * Since we pass the port number as an ascii string to the proxy,
3120 	 *  we need it in host format.
3121 	 */
3122 	dest_port = ntohs(target_port);
3123 	sp = getservbyname("telnet-passthru", "tcp");
3124 	if (sp == 0) {
3125 		(void) fprintf(stderr,
3126 		    "telnet: tcp/telnet-passthru: unknown service\n");
3127 			goto tn_exit;
3128 	}
3129 	target_port = sp->s_port;
3130 #endif
3131 	h = host;
3132 
3133 	/*
3134 	 * For IPv6 source routing, we need to initialize option buffer only
3135 	 * once.
3136 	 */
3137 	if (num_gw > 0 && (addr_type == ALL_ADDRS || addr_type == ONLY_V6)) {
3138 		if (!prepare_optbuf6(gw_addrs, num_gw, &opt_buf6,
3139 		    &opt_buf_len6)) {
3140 			goto tn_exit;
3141 		}
3142 	}
3143 
3144 	/*
3145 	 * We procure the Kerberos config files options only
3146 	 * if the user has choosen Krb5 authentication.
3147 	 */
3148 	if (krb5auth_flag > 0) {
3149 		krb5_profile_get_options(hostname, telnet_krb5_realm,
3150 			config_file_options);
3151 	}
3152 
3153 	if (encrypt_flag) {
3154 		extern boolean_t auth_enable_encrypt;
3155 		if (krb5_privacy_allowed()) {
3156 			encrypt_auto(1);
3157 			decrypt_auto(1);
3158 			wantencryption = B_TRUE;
3159 			autologin = 1;
3160 			auth_enable_encrypt = B_TRUE;
3161 		} else {
3162 			(void) fprintf(stderr, gettext(
3163 			    "%s:Encryption not supported.\n"), prompt);
3164 			exit(1);
3165 			}
3166 	}
3167 
3168 	if (forward_flag && forwardable_flag) {
3169 		(void) fprintf(stderr, gettext(
3170 			"Error in krb5 configuration file. "
3171 			"Both forward and forwardable are set.\n"));
3172 		exit(1);
3173 	}
3174 	if (forwardable_flag) {
3175 		forward_flags |= OPTS_FORWARD_CREDS | OPTS_FORWARDABLE_CREDS;
3176 	} else if (forward_flag)
3177 		forward_flags |= OPTS_FORWARD_CREDS;
3178 
3179 
3180 	do {
3181 		/*
3182 		 * Search for an address of desired type in the IP address list
3183 		 * of the target.
3184 		 */
3185 		while (h != NULL) {
3186 			struct sockaddr_in6 *addr;
3187 
3188 			addr = (struct sockaddr_in6 *)h->ai_addr;
3189 
3190 			if (h->ai_family == AF_INET6)
3191 				is_v4mapped =
3192 				    IN6_IS_ADDR_V4MAPPED(&addr->sin6_addr);
3193 			else
3194 				is_v4mapped = B_FALSE;
3195 
3196 			if (addr_type == ALL_ADDRS ||
3197 			    (addr_type == ONLY_V6 &&
3198 				h->ai_family == AF_INET6) ||
3199 			    (addr_type == ONLY_V4 &&
3200 				(h->ai_family == AF_INET || is_v4mapped)))
3201 				break;
3202 
3203 			/* skip undesired typed addresses */
3204 			h = h->ai_next;
3205 		}
3206 
3207 		if (h == NULL) {
3208 			fprintf(stderr,
3209 			    "telnet: Unable to connect to remote host");
3210 			goto tn_exit;
3211 		}
3212 
3213 		/*
3214 		 * We need to open a socket with a family matching the type of
3215 		 * address we are trying to connect to. This is because we
3216 		 * deal with IPv4 options and IPv6 extension headers.
3217 		 */
3218 		if (h->ai_family == AF_INET) {
3219 			addrp = &((struct sockaddr_in *)(h->ai_addr))->sin_addr;
3220 			((struct sockaddr_in *)(h->ai_addr))->sin_port =
3221 			    target_port;
3222 		} else {
3223 			addrp = &((struct sockaddr_in6 *)(h->ai_addr))
3224 			    ->sin6_addr;
3225 			((struct sockaddr_in6 *)(h->ai_addr))->sin6_port =
3226 			    target_port;
3227 		}
3228 
3229 		(void) printf("Trying %s...\n", inet_ntop(h->ai_family,
3230 		    addrp, abuf, sizeof (abuf)));
3231 
3232 		net = socket(h->ai_family, SOCK_STREAM, 0);
3233 
3234 		if (net < 0) {
3235 			perror("telnet: socket");
3236 			goto tn_exit;
3237 		}
3238 #ifndef ICMD
3239 		if (num_gw > 0) {
3240 			if (h->ai_family == AF_INET || is_v4mapped) {
3241 				if (!prepare_optbuf(gw_addrs, num_gw, &opt_buf,
3242 				    &opt_buf_len, addrp, src_rtng_type)) {
3243 					goto tn_exit;
3244 				}
3245 
3246 				if (setsockopt(net, IPPROTO_IP, IP_OPTIONS,
3247 				    opt_buf, opt_buf_len) < 0)
3248 					perror("setsockopt (IP_OPTIONS)");
3249 			} else {
3250 				if (setsockopt(net, IPPROTO_IPV6, IPV6_RTHDR,
3251 				    opt_buf6, opt_buf_len6) < 0)
3252 					perror("setsockopt (IPV6_RTHDR)");
3253 			}
3254 		}
3255 #endif
3256 #if	defined(USE_TOS)
3257 		if (is_v4mapped) {
3258 			if (tos < 0)
3259 				tos = 020;	/* Low Delay bit */
3260 			if (tos &&
3261 			    (setsockopt(net, IPPROTO_IP, IP_TOS,
3262 			    &tos, sizeof (int)) < 0) &&
3263 			    (errno != ENOPROTOOPT))
3264 				perror("telnet: setsockopt (IP_TOS) (ignored)");
3265 		}
3266 #endif	/* defined(USE_TOS) */
3267 
3268 		if (debug && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 1) < 0) {
3269 			perror("setsockopt (SO_DEBUG)");
3270 		}
3271 
3272 		ret_val = connect(net, h->ai_addr, h->ai_addrlen);
3273 
3274 		/*
3275 		 * If failed, try the next address of the target.
3276 		 */
3277 		if (ret_val < 0) {
3278 			Close(&net);
3279 			if (h->ai_next != NULL) {
3280 
3281 				int oerrno = errno;
3282 
3283 				(void) fprintf(stderr,
3284 				    "telnet: connect to address %s: ", abuf);
3285 				errno = oerrno;
3286 				perror((char *)0);
3287 
3288 				h = h->ai_next;
3289 				continue;
3290 			}
3291 			perror("telnet: Unable to connect to remote host");
3292 			goto tn_exit;
3293 		}
3294 		connected++;
3295 	} while (connected == 0);
3296 	freeaddrinfo(host);
3297 	host = NULL;
3298 #ifdef ICMD
3299 	/*
3300 	 * Do initial protocol to connect to farther end...
3301 	 */
3302 	{
3303 		char buf[1024];
3304 		(void) sprintf(buf, "%s %d\n", real_host, (int)dest_port);
3305 		write(net, buf, strlen(buf));
3306 	}
3307 #endif
3308 	if (cmdrc(hostp, hostname) != 0)
3309 		goto tn_exit;
3310 	FreeHostnameList(hostname_list);
3311 	if (autologin && user == NULL) {
3312 		struct passwd *pw;
3313 
3314 		user = getenv("LOGNAME");
3315 		if (user == NULL ||
3316 		    ((pw = getpwnam(user)) != NULL) &&
3317 		    pw->pw_uid != getuid()) {
3318 			if (pw = getpwuid(getuid()))
3319 				user = pw->pw_name;
3320 			else
3321 				user = NULL;
3322 		}
3323 	}
3324 
3325 	if (user) {
3326 		if (env_define((unsigned char *)"USER", (unsigned char *)user))
3327 			env_export((unsigned char *)"USER");
3328 		else {
3329 			/* Clean up and exit. */
3330 			Close(&net);
3331 			(void) snprintf(buf, sizeof (buf),
3332 			    "Connection to %.*s closed.\n",
3333 			    MAXHOSTNAMELEN, hostname);
3334 			ExitString(buf, EXIT_FAILURE);
3335 
3336 			/* NOTREACHED */
3337 		}
3338 	}
3339 	(void) call(3, status, "status", "notmuch");
3340 	if (setjmp(peerdied) == 0)
3341 		telnet(user);
3342 
3343 	Close(&net);
3344 
3345 	(void) snprintf(buf, sizeof (buf),
3346 	    "Connection to %.*s closed by foreign host.\n",
3347 	    MAXHOSTNAMELEN, hostname);
3348 	ExitString(buf, EXIT_FAILURE);
3349 
3350 	/*NOTREACHED*/
3351 
3352 tn_exit:
3353 	FreeHostnameList(hostname_list);
3354 	Close(&net);
3355 	connected = 0;
3356 	if (host != NULL)
3357 		freeaddrinfo(host);
3358 	return (0);
3359 }
3360 
3361 #define	HELPINDENT (sizeof ("connect"))
3362 
3363 static char openhelp[] = "connect to a site";
3364 static char closehelp[] = "close current connection";
3365 static char logouthelp[] =
3366 	    "forcibly logout remote user and close the connection";
3367 static char quithelp[] = "exit telnet";
3368 static char statushelp[] = "print status information";
3369 static char helphelp[] = "print help information";
3370 static char sendhelp[] =
3371 	    "transmit special characters ('send ?' for more)";
3372 static char sethelp[] =  "set operating parameters ('set ?' for more)";
3373 static char unsethelp[] = "unset operating parameters ('unset ?' for more)";
3374 static char togglestring[] =
3375 	    "toggle operating parameters ('toggle ?' for more)";
3376 static char slchelp[] = "change state of special charaters ('slc ?' for more)";
3377 static char displayhelp[] = "display operating parameters";
3378 static char authhelp[] =
3379 	    "turn on (off) authentication ('auth ?' for more)";
3380 static char forwardhelp[] =
3381 	    "turn on (off) credential forwarding ('forward ?' for more)";
3382 static char encrypthelp[] =
3383 	    "turn on (off) encryption ('encrypt ?' for more)";
3384 static char zhelp[] = "suspend telnet";
3385 static char shellhelp[] = "invoke a subshell";
3386 static char envhelp[] = "change environment variables ('environ ?' for more)";
3387 static char modestring[] =
3388 	    "try to enter line or character mode ('mode ?' for more)";
3389 
3390 static int	help();
3391 
3392 static Command cmdtab[] = {
3393 	{ "close",	closehelp,	bye,		1 },
3394 	{ "logout",	logouthelp,	logout,		1 },
3395 	{ "display",	displayhelp,	display,	0 },
3396 	{ "mode",	modestring,	modecmd,	0 },
3397 	{ "open",	openhelp,	tn,		0 },
3398 	{ "quit",	quithelp,	quit,		0 },
3399 	{ "send",	sendhelp,	sendcmd,	0 },
3400 	{ "set",	sethelp,	setcmd,		0 },
3401 	{ "unset",	unsethelp,	unsetcmd,	0 },
3402 	{ "status",	statushelp,	status,		0 },
3403 	{ "toggle",	togglestring,	toggle,		0 },
3404 	{ "slc",	slchelp,	slccmd,		0 },
3405 	{ "auth",	authhelp,	auth_cmd,	0 },
3406 	{ "encrypt",	encrypthelp,	encrypt_cmd,	0 },
3407 	{ "forward",	forwardhelp,	forw_cmd,	0 },
3408 	{ "z",		zhelp,		suspend,	0 },
3409 	{ "!",		shellhelp,	shell,		0 },
3410 	{ "environ",	envhelp,	env_cmd,	0 },
3411 	{ "?",		helphelp,	help,		0 },
3412 	0
3413 };
3414 
3415 
3416 static Command cmdtab2[] = {
3417 	{ "help",	0,		help,		0 },
3418 	{ "escape",	0,		setescape,	0 },
3419 	{ "crmod",	0,		togcrmod,	0 },
3420 	0
3421 };
3422 
3423 
3424 /*
3425  * Call routine with argc, argv set from args.
3426  * Uses /usr/include/stdarg.h
3427  */
3428 #define	MAXVARGS	100
3429 /*VARARGS1*/
3430 static void
3431 call(int n_ptrs, ...)
3432 {
3433 	va_list ap;
3434 	typedef int (*intrtn_t)();
3435 	intrtn_t routine;
3436 	char *args[MAXVARGS+1];	/* leave 1 for trailing NULL */
3437 	int argno = 0;
3438 
3439 	if (n_ptrs > MAXVARGS)
3440 		n_ptrs = MAXVARGS;
3441 	va_start(ap, n_ptrs);
3442 
3443 	routine = (va_arg(ap, intrtn_t)); /* extract the routine's name */
3444 	n_ptrs--;
3445 
3446 	while (argno < n_ptrs)	/* extract the routine's args */
3447 		args[argno++] = va_arg(ap, char *);
3448 	args[argno] = NULL;	/* NULL terminate for good luck */
3449 	va_end(ap);
3450 
3451 	(*routine)(argno, args);
3452 }
3453 
3454 
3455 static Command *
3456 getcmd(name)
3457 	char *name;
3458 {
3459 	Command *cm;
3460 
3461 	if (cm = (Command *) genget(name, (char **)cmdtab, sizeof (Command)))
3462 		return (cm);
3463 	return (Command *) genget(name, (char **)cmdtab2, sizeof (Command));
3464 }
3465 
3466 void
3467 command(top, tbuf, cnt)
3468 	int top;
3469 	char *tbuf;
3470 	int cnt;
3471 {
3472 	Command *c;
3473 
3474 	setcommandmode();
3475 	if (!top) {
3476 		(void) putchar('\n');
3477 	} else {
3478 		(void) signal(SIGINT, SIG_DFL);
3479 		(void) signal(SIGQUIT, SIG_DFL);
3480 	}
3481 	for (;;) {
3482 		if (rlogin == _POSIX_VDISABLE)
3483 			(void) printf("%s> ", prompt);
3484 		if (tbuf) {
3485 			char *cp;
3486 			if (AllocStringBuffer(&line, &linesize, cnt) == NULL)
3487 				goto command_exit;
3488 			cp = line;
3489 			while (cnt > 0 && (*cp++ = *tbuf++) != '\n')
3490 				cnt--;
3491 			tbuf = 0;
3492 			if (cp == line || *--cp != '\n' || cp == line)
3493 				goto getline;
3494 			*cp = '\0';
3495 			if (rlogin == _POSIX_VDISABLE)
3496 				(void) printf("%s\n", line);
3497 		} else {
3498 getline:
3499 			if (rlogin != _POSIX_VDISABLE)
3500 				(void) printf("%s> ", prompt);
3501 			if (GetString(&line, &linesize, stdin) == NULL) {
3502 				if (!feof(stdin))
3503 					perror("telnet");
3504 				(void) quit();
3505 				/*NOTREACHED*/
3506 				break;
3507 			}
3508 		}
3509 		if (line[0] == 0)
3510 			break;
3511 		makeargv();
3512 		if (margv[0] == 0) {
3513 			break;
3514 		}
3515 		c = getcmd(margv[0]);
3516 		if (Ambiguous(c)) {
3517 			(void) printf("?Ambiguous command\n");
3518 			continue;
3519 		}
3520 		if (c == 0) {
3521 			(void) printf("?Invalid command\n");
3522 			continue;
3523 		}
3524 		if (c->needconnect && !connected) {
3525 			(void) printf("?Need to be connected first.\n");
3526 			continue;
3527 		}
3528 		if ((*c->handler)(margc, margv)) {
3529 			break;
3530 		}
3531 	}
3532 command_exit:
3533 	if (!top) {
3534 		if (!connected) {
3535 			longjmp(toplevel, 1);
3536 			/*NOTREACHED*/
3537 		}
3538 		setconnmode(0);
3539 	}
3540 }
3541 
3542 /*
3543  * Help command.
3544  */
3545 	static int
3546 help(argc, argv)
3547 	int argc;
3548 	char *argv[];
3549 {
3550 	register Command *c;
3551 
3552 	if (argc == 1) {
3553 		(void) printf(
3554 		    "Commands may be abbreviated.  Commands are:\n\n");
3555 		for (c = cmdtab; c->name; c++)
3556 			if (c->help) {
3557 				(void) printf("%-*s\t%s\n", HELPINDENT,
3558 					c->name, c->help);
3559 			}
3560 		(void) printf("<return>\tleave command mode\n");
3561 		return (0);
3562 	}
3563 	while (--argc > 0) {
3564 		register char *arg;
3565 		arg = *++argv;
3566 		c = getcmd(arg);
3567 		if (Ambiguous(c))
3568 			(void) printf("?Ambiguous help command %s\n", arg);
3569 		else if (c == (Command *)0)
3570 			(void) printf("?Invalid help command %s\n", arg);
3571 		else if (c->help) {
3572 			(void) printf("%s\n", c->help);
3573 		} else  {
3574 			(void) printf("No additional help on %s\n", arg);
3575 		}
3576 	}
3577 	return (0);
3578 }
3579 
3580 static char *rcname = NULL;
3581 #define	TELNETRC_NAME "telnetrc"
3582 #define	TELNETRC_COMP "/." TELNETRC_NAME
3583 
3584 static int
3585 cmdrc(char *m1, char *m2)
3586 {
3587 	Command *c;
3588 	FILE *rcfile = NULL;
3589 	int gotmachine = 0;
3590 	int l1 = strlen(m1);
3591 	int l2 = strlen(m2);
3592 	char m1save[MAXHOSTNAMELEN];
3593 	int ret = 0;
3594 	char def[] = "DEFAULT";
3595 
3596 	if (skiprc)
3597 		goto cmdrc_exit;
3598 
3599 	doing_rc = 1;
3600 
3601 	(void) strlcpy(m1save, m1, sizeof (m1save));
3602 	m1 = m1save;
3603 
3604 	if (rcname == NULL) {
3605 		char *homedir;
3606 		unsigned rcbuflen;
3607 
3608 		if ((homedir = getenv("HOME")) == NULL)
3609 			homedir = "";
3610 
3611 		rcbuflen = strlen(homedir) + strlen(TELNETRC_COMP) + 1;
3612 		if ((rcname = malloc(rcbuflen)) == NULL) {
3613 			perror("telnet: can't process " TELNETRC_NAME);
3614 			ret = 1;
3615 			goto cmdrc_exit;
3616 		}
3617 		(void) strcpy(rcname, homedir);
3618 		(void) strcat(rcname, TELNETRC_COMP);
3619 	}
3620 
3621 	if ((rcfile = fopen(rcname, "r")) == NULL)
3622 		goto cmdrc_exit;
3623 
3624 	for (;;) {
3625 		if (GetString(&line, &linesize, rcfile) == NULL) {
3626 			if (!feof(rcfile)) {
3627 				perror("telnet: error reading " TELNETRC_NAME);
3628 				ret = 1;
3629 				goto cmdrc_exit;
3630 			}
3631 			break;
3632 		}
3633 		if (line[0] == 0)
3634 			continue;
3635 		if (line[0] == '#')
3636 			continue;
3637 		if (gotmachine) {
3638 			if (!isspace(line[0]))
3639 			gotmachine = 0;
3640 		}
3641 		if (gotmachine == 0) {
3642 			if (isspace(line[0]))
3643 				continue;
3644 			if (strncasecmp(line, m1, l1) == 0)
3645 				(void) strcpy(line, &line[l1]);
3646 			else if (strncasecmp(line, m2, l2) == 0)
3647 				(void) strcpy(line, &line[l2]);
3648 			else if (strncasecmp(line, def, sizeof (def) - 1) == 0)
3649 				(void) strcpy(line, &line[sizeof (def) - 1]);
3650 			else
3651 				continue;
3652 			if (line[0] != ' ' && line[0] != '\t' &&
3653 			    line[0] != '\n')
3654 				continue;
3655 			gotmachine = 1;
3656 		}
3657 		makeargv();
3658 		if (margv[0] == 0)
3659 			continue;
3660 		c = getcmd(margv[0]);
3661 		if (Ambiguous(c)) {
3662 			(void) printf("?Ambiguous command: %s\n", margv[0]);
3663 			continue;
3664 		}
3665 		if (c == 0) {
3666 			(void) printf("?Invalid command: %s\n", margv[0]);
3667 			continue;
3668 		}
3669 		/*
3670 		 * This should never happen...
3671 		 */
3672 		if (c->needconnect && !connected) {
3673 			(void) printf("?Need to be connected first for %s.\n",
3674 			    margv[0]);
3675 			continue;
3676 		}
3677 		(*c->handler)(margc, margv);
3678 	}
3679 cmdrc_exit:
3680 	if (rcfile != NULL)
3681 		(void) fclose(rcfile);
3682 	doing_rc = 0;
3683 
3684 	return (ret);
3685 }
3686