xref: /openbsd/usr.bin/telnet/commands.c (revision 259ea3b8)
1 /*	$OpenBSD: commands.c,v 1.89 2024/08/26 21:34:32 op Exp $	*/
2 /*	$NetBSD: commands.c,v 1.14 1996/03/24 22:03:48 jtk Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "telnet_locl.h"
34 
35 #include <sys/socket.h>
36 #include <netinet/in.h>
37 #include <netinet/ip.h>
38 #include <arpa/inet.h>
39 #include <arpa/telnet.h>
40 
41 #include <ctype.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <netdb.h>
45 #include <pwd.h>
46 #include <stdarg.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <limits.h>
51 
52 char	*hostname;
53 
54 typedef struct {
55 	char	*name;		/* command name */
56 	char	*help;		/* help string (NULL for no help) */
57 	int	(*handler)(int, char **);/* routine which executes command */
58 	int	needconnect;	/* Do we need to be connected to execute? */
59 } Command;
60 
61 #define        MAXARGV         20
62 
63 static char line[256];
64 static int margc;
65 static char *margv[MAXARGV+1];
66 
67 static int
makeargv(void)68 makeargv(void)
69 {
70     char *cp, *cp2, c;
71     char **argp = margv;
72     int ret = 0;
73 
74     margc = 0;
75     cp = line;
76     while ((c = *cp)) {
77         if (margc >= MAXARGV) {
78             printf("too many arguments\n");
79             ret = 1;
80             break;
81         }
82 	int inquote = 0;
83 	while (isspace((unsigned char)c))
84 	    c = *++cp;
85 	if (c == '\0')
86 	    break;
87 	*argp++ = cp;
88 	margc += 1;
89 	for (cp2 = cp; c != '\0'; c = *++cp) {
90 	    if (inquote) {
91 		if (c == inquote) {
92 		    inquote = 0;
93 		    continue;
94 		}
95 	    } else {
96 		if (c == '\\') {
97 		    if ((c = *++cp) == '\0')
98 			break;
99 		} else if (c == '"') {
100 		    inquote = '"';
101 		    continue;
102 		} else if (c == '\'') {
103 		    inquote = '\'';
104 		    continue;
105 		} else if (isspace((unsigned char)c))
106 		    break;
107 	    }
108 	    *cp2++ = c;
109 	}
110 	*cp2 = '\0';
111 	if (c == '\0')
112 	    break;
113 	cp++;
114     }
115     *argp++ = 0;
116     return (ret);
117 }
118 
119 /*
120  * Make a character string into a number.
121  *
122  * Todo:  1.  Could take random integers (12, 0x12, 012, 0b1).
123  */
124 
125 static char
special(char * s)126 special(char *s)
127 {
128 	char c;
129 	char b;
130 
131 	switch (*s) {
132 	case '^':
133 		b = *++s;
134 		if (b == '?') {
135 		    c = b | 0x40;		/* DEL */
136 		} else {
137 		    c = b & 0x1f;
138 		}
139 		break;
140 	default:
141 		c = *s;
142 		break;
143 	}
144 	return c;
145 }
146 
147 /*
148  * Construct a control character sequence
149  * for a special character.
150  */
151 static char *
control(cc_t c)152 control(cc_t c)
153 {
154 	static char buf[5];
155 	/*
156 	 * The only way I could get the Sun 3.5 compiler
157 	 * to shut up about
158 	 *	if ((unsigned int)c >= 0x80)
159 	 * was to assign "c" to an unsigned int variable...
160 	 * Arggg....
161 	 */
162 	unsigned int uic = (unsigned int)c;
163 
164 	if (uic == 0x7f)
165 		return ("^?");
166 	if (c == (cc_t)_POSIX_VDISABLE) {
167 		return "off";
168 	}
169 	if (uic >= 0x80) {
170 		buf[0] = '\\';
171 		buf[1] = ((c>>6)&07) + '0';
172 		buf[2] = ((c>>3)&07) + '0';
173 		buf[3] = (c&07) + '0';
174 		buf[4] = 0;
175 	} else if (uic >= 0x20) {
176 		buf[0] = c;
177 		buf[1] = 0;
178 	} else {
179 		buf[0] = '^';
180 		buf[1] = '@'+c;
181 		buf[2] = 0;
182 	}
183 	return (buf);
184 }
185 
186 /*
187  *	The following are data structures and routines for
188  *	the "send" command.
189  *
190  */
191 
192 struct sendlist {
193     char	*name;		/* How user refers to it (case independent) */
194     char	*help;		/* Help information (0 ==> no help) */
195     int		needconnect;	/* Need to be connected */
196     int		narg;		/* Number of arguments */
197     int		(*handler)();	/* Routine to perform (for special ops) */
198     int		nbyte;		/* Number of bytes to send this command */
199     int		what;		/* Character to be sent (<0 ==> special) */
200 };
201 
202 
203 static int
204 	send_esc(void),
205 	send_help(void),
206 	send_docmd(char *),
207 	send_dontcmd(char *),
208 	send_willcmd(char *),
209 	send_wontcmd(char *);
210 
211 static struct sendlist Sendlist[] = {
212     { "ao",	"Send Telnet Abort output",		1, 0, 0, 2, AO },
213     { "ayt",	"Send Telnet 'Are You There'",		1, 0, 0, 2, AYT },
214     { "brk",	"Send Telnet Break",			1, 0, 0, 2, BREAK },
215     { "break",	0,					1, 0, 0, 2, BREAK },
216     { "ec",	"Send Telnet Erase Character",		1, 0, 0, 2, EC },
217     { "el",	"Send Telnet Erase Line",		1, 0, 0, 2, EL },
218     { "escape",	"Send current escape character",	1, 0, send_esc, 1, 0 },
219     { "ga",	"Send Telnet 'Go Ahead' sequence",	1, 0, 0, 2, GA },
220     { "ip",	"Send Telnet Interrupt Process",	1, 0, 0, 2, IP },
221     { "intp",	0,					1, 0, 0, 2, IP },
222     { "interrupt", 0,					1, 0, 0, 2, IP },
223     { "intr",	0,					1, 0, 0, 2, IP },
224     { "nop",	"Send Telnet 'No operation'",		1, 0, 0, 2, NOP },
225     { "eor",	"Send Telnet 'End of Record'",		1, 0, 0, 2, EOR },
226     { "abort",	"Send Telnet 'Abort Process'",		1, 0, 0, 2, ABORT },
227     { "susp",	"Send Telnet 'Suspend Process'",	1, 0, 0, 2, SUSP },
228     { "eof",	"Send Telnet End of File Character",	1, 0, 0, 2, xEOF },
229     { "synch",	"Perform Telnet 'Synch operation'",	1, 0, dosynch, 2, 0 },
230     { "getstatus", "Send request for STATUS",		1, 0, get_status, 6, 0 },
231     { "?",	"Display send options",			0, 0, send_help, 0, 0 },
232     { "help",	0,					0, 0, send_help, 0, 0 },
233     { "do",	0,					0, 1, send_docmd, 3, 0 },
234     { "dont",	0,					0, 1, send_dontcmd, 3, 0 },
235     { "will",	0,					0, 1, send_willcmd, 3, 0 },
236     { "wont",	0,					0, 1, send_wontcmd, 3, 0 },
237     { 0 }
238 };
239 
240 #define	GETSEND(name) ((struct sendlist *) genget(name, (char **) Sendlist, \
241 				sizeof(struct sendlist)))
242 
243 static int
sendcmd(int argc,char ** argv)244 sendcmd(int argc, char **argv)
245 {
246     int count;		/* how many bytes we are going to need to send */
247     int i;
248     struct sendlist *s;	/* pointer to current command */
249     int success = 0;
250     int needconnect = 0;
251 
252     if (argc < 2) {
253 	printf("need at least one argument for 'send' command\r\n");
254 	printf("'send ?' for help\r\n");
255 	return 0;
256     }
257     /*
258      * First, validate all the send arguments.
259      * In addition, we see how much space we are going to need, and
260      * whether or not we will be doing a "SYNCH" operation (which
261      * flushes the network queue).
262      */
263     count = 0;
264     for (i = 1; i < argc; i++) {
265 	s = GETSEND(argv[i]);
266 	if (s == 0) {
267 	    printf("Unknown send argument '%s'\r\n'send ?' for help.\r\n",
268 			argv[i]);
269 	    return 0;
270 	} else if (Ambiguous(s)) {
271 	    printf("Ambiguous send argument '%s'\r\n'send ?' for help.\r\n",
272 			argv[i]);
273 	    return 0;
274 	}
275 	if (i + s->narg >= argc) {
276 	    fprintf(stderr,
277 	    "Need %d argument%s to 'send %s' command.  'send %s ?' for help.\r\n",
278 		s->narg, s->narg == 1 ? "" : "s", s->name, s->name);
279 	    return 0;
280 	}
281 	count += s->nbyte;
282 	if (s->handler == send_help) {
283 	    send_help();
284 	    return 0;
285 	}
286 
287 	i += s->narg;
288 	needconnect += s->needconnect;
289     }
290     if (!connected && needconnect) {
291 	printf("?Need to be connected first.\r\n");
292 	printf("'send ?' for help\r\n");
293 	return 0;
294     }
295     /* Now, do we have enough room? */
296     if (NETROOM() < count) {
297 	printf("There is not enough room in the buffer TO the network\r\n");
298 	printf("to process your request.  Nothing will be done.\r\n");
299 	printf("('send synch' will throw away most data in the network\r\n");
300 	printf("buffer, if this might help.)\r\n");
301 	return 0;
302     }
303     /* OK, they are all OK, now go through again and actually send */
304     count = 0;
305     for (i = 1; i < argc; i++) {
306 	if ((s = GETSEND(argv[i])) == 0) {
307 	    fprintf(stderr, "Telnet 'send' error - argument disappeared!\r\n");
308 	    quit();
309 	}
310 	if (s->handler) {
311 	    count++;
312 	    success += (*s->handler)((s->narg > 0) ? argv[i+1] : 0,
313 				  (s->narg > 1) ? argv[i+2] : 0);
314 	    i += s->narg;
315 	} else {
316 	    NET2ADD(IAC, s->what);
317 	    printoption("SENT", IAC, s->what);
318 	}
319     }
320     return (count == success);
321 }
322 
323 static int send_tncmd(void (*func)(int, int), char *cmd, char *name);
324 
325 static int
send_esc(void)326 send_esc(void)
327 {
328     NETADD(escape);
329     return 1;
330 }
331 
332 static int
send_docmd(char * name)333 send_docmd(char *name)
334 {
335     return(send_tncmd(send_do, "do", name));
336 }
337 
338 static int
send_dontcmd(char * name)339 send_dontcmd(char *name)
340 {
341     return(send_tncmd(send_dont, "dont", name));
342 }
343 
344 static int
send_willcmd(char * name)345 send_willcmd(char *name)
346 {
347     return(send_tncmd(send_will, "will", name));
348 }
349 
350 static int
send_wontcmd(char * name)351 send_wontcmd(char *name)
352 {
353     return(send_tncmd(send_wont, "wont", name));
354 }
355 
356 int
send_tncmd(void (* func)(int,int),char * cmd,char * name)357 send_tncmd(void (*func)(int, int), char *cmd, char *name)
358 {
359     char **cpp;
360     extern char *telopts[];
361     const char *errstr;
362     int val = 0;
363 
364     if (isprefix(name, "help") || isprefix(name, "?")) {
365 	int col, len;
366 
367 	printf("Usage: send %s <value|option>\r\n", cmd);
368 	printf("\"value\" must be from 0 to 255\r\n");
369 	printf("Valid options are:\r\n\t");
370 
371 	col = 8;
372 	for (cpp = telopts; *cpp; cpp++) {
373 	    len = strlen(*cpp) + 3;
374 	    if (col + len > 65) {
375 		printf("\r\n\t");
376 		col = 8;
377 	    }
378 	    printf(" \"%s\"", *cpp);
379 	    col += len;
380 	}
381 	printf("\r\n");
382 	return 0;
383     }
384     cpp = (char **)genget(name, telopts, sizeof(char *));
385     if (Ambiguous(cpp)) {
386 	fprintf(stderr,"'%s': ambiguous argument ('send %s ?' for help).\r\n",
387 					name, cmd);
388 	return 0;
389     }
390     if (cpp) {
391 	val = cpp - telopts;
392     } else {
393 	val = strtonum(name, 0, 255, &errstr);
394 	if (errstr) {
395 	    fprintf(stderr, "'%s': %s ('send %s ?' for help).\r\n",
396 					name, errstr, cmd);
397 	    return 0;
398 	}
399     }
400     if (!connected) {
401 	printf("?Need to be connected first.\r\n");
402 	return 0;
403     }
404     (*func)(val, 1);
405     return 1;
406 }
407 
408 static int
send_help(void)409 send_help(void)
410 {
411     struct sendlist *s;	/* pointer to current command */
412     for (s = Sendlist; s->name; s++) {
413 	if (s->help)
414 	    printf("%-15s %s\r\n", s->name, s->help);
415     }
416     return(0);
417 }
418 
419 /*
420  * The following are the routines and data structures referred
421  * to by the arguments to the "toggle" command.
422  */
423 
424 static int
lclchars(int unused)425 lclchars(int unused)
426 {
427     donelclchars = 1;
428     return 1;
429 }
430 
431 static int
togcrlf(int unused)432 togcrlf(int unused)
433 {
434     if (crlf) {
435 	printf("Will send carriage returns as telnet <CR><LF>.\r\n");
436     } else {
437 	printf("Will send carriage returns as telnet <CR><NUL>.\r\n");
438     }
439     return 1;
440 }
441 
442 int binmode;
443 
444 static int
togbinary(int val)445 togbinary(int val)
446 {
447     donebinarytoggle = 1;
448 
449     if (val >= 0) {
450 	binmode = val;
451     } else {
452 	if (my_want_state_is_will(TELOPT_BINARY) &&
453 				my_want_state_is_do(TELOPT_BINARY)) {
454 	    binmode = 1;
455 	} else if (my_want_state_is_wont(TELOPT_BINARY) &&
456 				my_want_state_is_dont(TELOPT_BINARY)) {
457 	    binmode = 0;
458 	}
459 	val = binmode ? 0 : 1;
460     }
461 
462     if (val == 1) {
463 	if (my_want_state_is_will(TELOPT_BINARY) &&
464 					my_want_state_is_do(TELOPT_BINARY)) {
465 	    printf("Already operating in binary mode with remote host.\r\n");
466 	} else {
467 	    printf("Negotiating binary mode with remote host.\r\n");
468 	    tel_enter_binary(3);
469 	}
470     } else {
471 	if (my_want_state_is_wont(TELOPT_BINARY) &&
472 					my_want_state_is_dont(TELOPT_BINARY)) {
473 	    printf("Already in network ascii mode with remote host.\r\n");
474 	} else {
475 	    printf("Negotiating network ascii mode with remote host.\r\n");
476 	    tel_leave_binary(3);
477 	}
478     }
479     return 1;
480 }
481 
482 static int
togrbinary(int val)483 togrbinary(int val)
484 {
485     donebinarytoggle = 1;
486 
487     if (val == -1)
488 	val = my_want_state_is_do(TELOPT_BINARY) ? 0 : 1;
489 
490     if (val == 1) {
491 	if (my_want_state_is_do(TELOPT_BINARY)) {
492 	    printf("Already receiving in binary mode.\r\n");
493 	} else {
494 	    printf("Negotiating binary mode on input.\r\n");
495 	    tel_enter_binary(1);
496 	}
497     } else {
498 	if (my_want_state_is_dont(TELOPT_BINARY)) {
499 	    printf("Already receiving in network ascii mode.\r\n");
500 	} else {
501 	    printf("Negotiating network ascii mode on input.\r\n");
502 	    tel_leave_binary(1);
503 	}
504     }
505     return 1;
506 }
507 
508 static int
togxbinary(int val)509 togxbinary(int val)
510 {
511     donebinarytoggle = 1;
512 
513     if (val == -1)
514 	val = my_want_state_is_will(TELOPT_BINARY) ? 0 : 1;
515 
516     if (val == 1) {
517 	if (my_want_state_is_will(TELOPT_BINARY)) {
518 	    printf("Already transmitting in binary mode.\r\n");
519 	} else {
520 	    printf("Negotiating binary mode on output.\r\n");
521 	    tel_enter_binary(2);
522 	}
523     } else {
524 	if (my_want_state_is_wont(TELOPT_BINARY)) {
525 	    printf("Already transmitting in network ascii mode.\r\n");
526 	} else {
527 	    printf("Negotiating network ascii mode on output.\r\n");
528 	    tel_leave_binary(2);
529 	}
530     }
531     return 1;
532 }
533 
534 
535 static int togglehelp(int);
536 
537 struct togglelist {
538     char	*name;			/* name of toggle */
539     char	*help;			/* help message */
540     int		(*handler)(int);	/* routine to do actual setting */
541     int		*variable;
542     char	*actionexplanation;
543     int		needconnect;	/* Need to be connected */
544 };
545 
546 static struct togglelist Togglelist[] = {
547     { "autoflush",
548 	"flushing of output when sending interrupt characters",
549 	    0,
550 		&autoflush,
551 		    "flush output when sending interrupt characters" },
552     { "autosynch",
553 	"automatic sending of interrupt characters in urgent mode",
554 	    0,
555 		&autosynch,
556 		    "send interrupt characters in urgent mode" },
557     { "autologin",
558 	"automatic sending of login name",
559 	    0,
560 		&autologin,
561 		    "send login name" },
562     { "skiprc",
563 	"don't read ~/.telnetrc file",
564 	    0,
565 		&skiprc,
566 		    "skip reading of ~/.telnetrc file" },
567     { "binary",
568 	"sending and receiving of binary data",
569 	    togbinary,
570 		0,
571 		    0 },
572     { "inbinary",
573 	"receiving of binary data",
574 	    togrbinary,
575 		0,
576 		    0 },
577     { "outbinary",
578 	"sending of binary data",
579 	    togxbinary,
580 		0,
581 		    0 },
582     { "crlf",
583 	"sending carriage returns as telnet <CR><LF>",
584 	    togcrlf,
585 		&crlf,
586 		    0 },
587     { "crmod",
588 	"mapping of received carriage returns",
589 	    0,
590 		&crmod,
591 		    "map carriage return on output" },
592     { "localchars",
593 	"local recognition of certain control characters",
594 	    lclchars,
595 		&localchars,
596 		    "recognize certain control characters" },
597     { " ", "", 0, 0 },		/* empty line */
598     { "netdata",
599 	"printing of hexadecimal network data (debugging)",
600 	    0,
601 		&netdata,
602 		    "print hexadecimal representation of network traffic" },
603     { "prettydump",
604 	"output of \"netdata\" to user readable format (debugging)",
605 	    0,
606 		&prettydump,
607 		    "print user readable output for \"netdata\"" },
608     { "options",
609 	"viewing of options processing (debugging)",
610 	    0,
611 		&showoptions,
612 		    "show option processing" },
613     { "termdata",
614 	"(debugging) toggle printing of hexadecimal terminal data",
615 	    0,
616 		&termdata,
617 		    "print hexadecimal representation of terminal traffic" },
618     { "?",
619 	0,
620 	    togglehelp },
621     { "help",
622 	0,
623 	    togglehelp },
624     { 0 }
625 };
626 
627 static int
togglehelp(int unused)628 togglehelp(int unused)
629 {
630     struct togglelist *c;
631 
632     for (c = Togglelist; c->name; c++) {
633 	if (c->help) {
634 	    if (*c->help)
635 		printf("%-15s toggle %s\r\n", c->name, c->help);
636 	    else
637 		printf("\r\n");
638 	}
639     }
640     printf("\r\n");
641     printf("%-15s %s\r\n", "?", "display help information");
642     return 0;
643 }
644 
645 static void
settogglehelp(int set)646 settogglehelp(int set)
647 {
648     struct togglelist *c;
649 
650     for (c = Togglelist; c->name; c++) {
651 	if (c->help) {
652 	    if (*c->help)
653 		printf("%-15s %s %s\r\n", c->name, set ? "enable" : "disable",
654 						c->help);
655 	    else
656 		printf("\r\n");
657 	}
658     }
659 }
660 
661 #define	GETTOGGLE(name) (struct togglelist *) \
662 		genget(name, (char **) Togglelist, sizeof(struct togglelist))
663 
664 static int
toggle(int argc,char * argv[])665 toggle(int argc, char *argv[])
666 {
667     int retval = 1;
668     char *name;
669     struct togglelist *c;
670 
671     if (argc < 2) {
672 	fprintf(stderr,
673 	    "Need an argument to 'toggle' command.  'toggle ?' for help.\r\n");
674 	return 0;
675     }
676     argc--;
677     argv++;
678     while (argc--) {
679 	name = *argv++;
680 	c = GETTOGGLE(name);
681 	if (Ambiguous(c)) {
682 	    fprintf(stderr, "'%s': ambiguous argument ('toggle ?' for help).\r\n",
683 					name);
684 	    return 0;
685 	} else if (c == 0) {
686 	    fprintf(stderr, "'%s': unknown argument ('toggle ?' for help).\r\n",
687 					name);
688 	    return 0;
689 	} else if (!connected && c->needconnect) {
690 	    printf("?Need to be connected first.\r\n");
691 	    printf("'send ?' for help\r\n");
692 	    return 0;
693 	} else {
694 	    if (c->variable) {
695 		*c->variable = !*c->variable;		/* invert it */
696 		if (c->actionexplanation) {
697 		    printf("%s %s.\r\n", *c->variable? "Will" : "Won't",
698 							c->actionexplanation);
699 		}
700 	    }
701 	    if (c->handler) {
702 		retval &= (*c->handler)(-1);
703 	    }
704 	}
705     }
706     return retval;
707 }
708 
709 /*
710  * The following perform the "set" command.
711  */
712 
713 struct termios new_tc = { 0 };
714 
715 struct setlist {
716     char *name;				/* name */
717     char *help;				/* help information */
718     void (*handler)(const char *);
719     cc_t *charp;			/* where it is located at */
720 };
721 
722 static struct setlist Setlist[] = {
723 #ifdef	KLUDGELINEMODE
724     { "echo", 	"character to toggle local echoing on/off", 0, &echoc },
725 #endif
726     { "escape",	"character to escape back to telnet command mode", 0, &escape },
727     { "rlogin", "rlogin escape character", 0, &rlogin },
728     { " ", "" },
729     { " ", "The following need 'localchars' to be toggled true", 0, 0 },
730     { "flushoutput", "character to cause an Abort Output", 0, &termFlushChar },
731     { "interrupt", "character to cause an Interrupt Process", 0, &termIntChar },
732     { "quit",	"character to cause an Abort process", 0, &termQuitChar },
733     { "eof",	"character to cause an EOF ", 0, &termEofChar },
734     { " ", "" },
735     { " ", "The following are for local editing in linemode", 0, 0 },
736     { "erase",	"character to use to erase a character", 0, &termEraseChar },
737     { "kill",	"character to use to erase a line", 0, &termKillChar },
738     { "lnext",	"character to use for literal next", 0, &termLiteralNextChar },
739     { "susp",	"character to cause a Suspend Process", 0, &termSuspChar },
740     { "reprint", "character to use for line reprint", 0, &termRprntChar },
741     { "worderase", "character to use to erase a word", 0, &termWerasChar },
742     { "start",	"character to use for XON", 0, &termStartChar },
743     { "stop",	"character to use for XOFF", 0, &termStopChar },
744     { "forw1",	"alternate end of line character", 0, &termForw1Char },
745     { "forw2",	"alternate end of line character", 0, &termForw2Char },
746     { "ayt",	"alternate AYT character", 0, &termAytChar },
747     { 0 }
748 };
749 
750 static struct setlist *
getset(char * name)751 getset(char *name)
752 {
753     return (struct setlist *)
754 		genget(name, (char **) Setlist, sizeof(struct setlist));
755 }
756 
757 void
set_escape_char(char * s)758 set_escape_char(char *s)
759 {
760 	if (rlogin != _POSIX_VDISABLE) {
761 		rlogin = (s && *s) ? special(s) : _POSIX_VDISABLE;
762 		printf("Telnet rlogin escape character is '%s'.\r\n",
763 					control(rlogin));
764 	} else {
765 		escape = (s && *s) ? special(s) : _POSIX_VDISABLE;
766 		printf("Telnet escape character is '%s'.\r\n", control(escape));
767 	}
768 }
769 
770 static int
setcmd(int argc,char * argv[])771 setcmd(int argc, char *argv[])
772 {
773     int value;
774     struct setlist *ct;
775     struct togglelist *c;
776 
777     if (argc < 2 || argc > 3) {
778 	printf("Format is 'set Name Value'\r\n'set ?' for help.\r\n");
779 	return 0;
780     }
781     if ((argc == 2) && (isprefix(argv[1], "?") || isprefix(argv[1], "help"))) {
782 	for (ct = Setlist; ct->name; ct++)
783 	    printf("%-15s %s\r\n", ct->name, ct->help);
784 	printf("\r\n");
785 	settogglehelp(1);
786 	printf("%-15s %s\r\n", "?", "display help information");
787 	return 0;
788     }
789 
790     ct = getset(argv[1]);
791     if (ct == 0) {
792 	c = GETTOGGLE(argv[1]);
793 	if (c == 0) {
794 	    fprintf(stderr, "'%s': unknown argument ('set ?' for help).\r\n",
795 			argv[1]);
796 	    return 0;
797 	} else if (Ambiguous(c)) {
798 	    fprintf(stderr, "'%s': ambiguous argument ('set ?' for help).\r\n",
799 			argv[1]);
800 	    return 0;
801 	} else if (!connected && c->needconnect) {
802 	    printf("?Need to be connected first.\r\n");
803 	    printf("'send ?' for help\r\n");
804 	    return 0;
805 	}
806 
807 	if (c->variable) {
808 	    if ((argc == 2) || (strcmp("on", argv[2]) == 0))
809 		*c->variable = 1;
810 	    else if (strcmp("off", argv[2]) == 0)
811 		*c->variable = 0;
812 	    else {
813 		printf("Format is 'set togglename [on|off]'\r\n'set ?' for help.\r\n");
814 		return 0;
815 	    }
816 	    if (c->actionexplanation) {
817 		printf("%s %s.\r\n", *c->variable? "Will" : "Won't",
818 							c->actionexplanation);
819 	    }
820 	}
821 	if (c->handler)
822 	    (*c->handler)(1);
823     } else if (argc != 3) {
824 	printf("Format is 'set Name Value'\r\n'set ?' for help.\r\n");
825 	return 0;
826     } else if (Ambiguous(ct)) {
827 	fprintf(stderr, "'%s': ambiguous argument ('set ?' for help).\r\n",
828 			argv[1]);
829 	return 0;
830     } else if (ct->handler) {
831 	(*ct->handler)(argv[2]);
832 	printf("%s set to \"%s\".\r\n", ct->name, (char *)ct->charp);
833     } else {
834 	if (strcmp("off", argv[2])) {
835 	    value = special(argv[2]);
836 	} else {
837 	    value = _POSIX_VDISABLE;
838 	}
839 	*(ct->charp) = (cc_t)value;
840 	printf("%s character is '%s'.\r\n", ct->name, control(*(ct->charp)));
841     }
842     slc_check();
843     return 1;
844 }
845 
846 static int
unsetcmd(int argc,char * argv[])847 unsetcmd(int argc, char *argv[])
848 {
849     struct setlist *ct;
850     struct togglelist *c;
851     char *name;
852 
853     if (argc < 2) {
854 	fprintf(stderr,
855 	    "Need an argument to 'unset' command.  'unset ?' for help.\r\n");
856 	return 0;
857     }
858     if (isprefix(argv[1], "?") || isprefix(argv[1], "help")) {
859 	for (ct = Setlist; ct->name; ct++)
860 	    printf("%-15s %s\r\n", ct->name, ct->help);
861 	printf("\r\n");
862 	settogglehelp(0);
863 	printf("%-15s %s\r\n", "?", "display help information");
864 	return 0;
865     }
866 
867     argc--;
868     argv++;
869     while (argc--) {
870 	name = *argv++;
871 	ct = getset(name);
872 	if (ct == 0) {
873 	    c = GETTOGGLE(name);
874 	    if (c == 0) {
875 		fprintf(stderr, "'%s': unknown argument ('unset ?' for help).\r\n",
876 			name);
877 		return 0;
878 	    } else if (Ambiguous(c)) {
879 		fprintf(stderr, "'%s': ambiguous argument ('unset ?' for help).\r\n",
880 			name);
881 		return 0;
882 	    }
883 	    if (c->variable) {
884 		*c->variable = 0;
885 		if (c->actionexplanation) {
886 		    printf("%s %s.\r\n", *c->variable? "Will" : "Won't",
887 							c->actionexplanation);
888 		}
889 	    }
890 	    if (c->handler)
891 		(*c->handler)(0);
892 	} else if (Ambiguous(ct)) {
893 	    fprintf(stderr, "'%s': ambiguous argument ('unset ?' for help).\r\n",
894 			name);
895 	    return 0;
896 	} else if (ct->handler) {
897 	    (*ct->handler)(NULL);
898 	    printf("%s reset to \"%s\".\r\n", ct->name, (char *)ct->charp);
899 	} else {
900 	    *(ct->charp) = _POSIX_VDISABLE;
901 	    printf("%s character is '%s'.\r\n", ct->name, control(*(ct->charp)));
902 	}
903     }
904     return 1;
905 }
906 
907 /*
908  * The following are the data structures and routines for the
909  * 'mode' command.
910  */
911 #ifdef	KLUDGELINEMODE
912 static int
dokludgemode(int unused)913 dokludgemode(int unused)
914 {
915     kludgelinemode = 1;
916     send_wont(TELOPT_LINEMODE, 1);
917     send_dont(TELOPT_SGA, 1);
918     send_dont(TELOPT_ECHO, 1);
919     return 1;
920 }
921 #endif
922 
923 static int
dolinemode(int unused)924 dolinemode(int unused)
925 {
926 #ifdef	KLUDGELINEMODE
927     if (kludgelinemode)
928 	send_dont(TELOPT_SGA, 1);
929 #endif
930     send_will(TELOPT_LINEMODE, 1);
931     send_dont(TELOPT_ECHO, 1);
932     return 1;
933 }
934 
935 static int
docharmode(int unused)936 docharmode(int unused)
937 {
938 #ifdef	KLUDGELINEMODE
939     if (kludgelinemode)
940 	send_do(TELOPT_SGA, 1);
941     else
942 #endif
943     send_wont(TELOPT_LINEMODE, 1);
944     send_do(TELOPT_ECHO, 1);
945     return 1;
946 }
947 
948 static int
dolmmode(int bit,int on)949 dolmmode(int bit, int on)
950 {
951     unsigned char c;
952 
953     if (my_want_state_is_wont(TELOPT_LINEMODE)) {
954 	printf("?Need to have LINEMODE option enabled first.\r\n");
955 	printf("'mode ?' for help.\r\n");
956 	return 0;
957     }
958 
959     if (on)
960 	c = (linemode | bit);
961     else
962 	c = (linemode & ~bit);
963     lm_mode(&c, 1, 1);
964     return 1;
965 }
966 
967 int
tn_setmode(int bit)968 tn_setmode(int bit)
969 {
970     return dolmmode(bit, 1);
971 }
972 
973 int
tn_clearmode(int bit)974 tn_clearmode(int bit)
975 {
976     return dolmmode(bit, 0);
977 }
978 
979 struct modelist {
980 	char	*name;		/* command name */
981 	char	*help;		/* help string */
982 	int	(*handler)(int);/* routine which executes command */
983 	int	needconnect;	/* Do we need to be connected to execute? */
984 	int	arg1;
985 };
986 
987 static int modehelp(int);
988 
989 static struct modelist ModeList[] = {
990     { "character", "Disable LINEMODE option",	docharmode, 1 },
991 #ifdef	KLUDGELINEMODE
992     { "",	"(or disable obsolete line-by-line mode)", 0 },
993 #endif
994     { "line",	"Enable LINEMODE option",	dolinemode, 1 },
995 #ifdef	KLUDGELINEMODE
996     { "",	"(or enable obsolete line-by-line mode)", 0 },
997 #endif
998     { "", "", 0 },
999     { "",	"These require the LINEMODE option to be enabled", 0 },
1000     { "isig",	"Enable signal trapping",	tn_setmode, 1, MODE_TRAPSIG },
1001     { "+isig",	0,				tn_setmode, 1, MODE_TRAPSIG },
1002     { "-isig",	"Disable signal trapping",	tn_clearmode, 1, MODE_TRAPSIG },
1003     { "edit",	"Enable character editing",	tn_setmode, 1, MODE_EDIT },
1004     { "+edit",	0,				tn_setmode, 1, MODE_EDIT },
1005     { "-edit",	"Disable character editing",	tn_clearmode, 1, MODE_EDIT },
1006     { "softtabs", "Enable tab expansion",	tn_setmode, 1, MODE_SOFT_TAB },
1007     { "+softtabs", 0,				tn_setmode, 1, MODE_SOFT_TAB },
1008     { "-softtabs", "Disable character editing",	tn_clearmode, 1, MODE_SOFT_TAB },
1009     { "litecho", "Enable literal character echo", tn_setmode, 1, MODE_LIT_ECHO },
1010     { "+litecho", 0,				tn_setmode, 1, MODE_LIT_ECHO },
1011     { "-litecho", "Disable literal character echo", tn_clearmode, 1, MODE_LIT_ECHO },
1012     { "help",	0,				modehelp, 0 },
1013 #ifdef	KLUDGELINEMODE
1014     { "kludgeline", 0,				dokludgemode, 1 },
1015 #endif
1016     { "", "", 0 },
1017     { "?",	"Print help information",	modehelp, 0 },
1018     { 0 },
1019 };
1020 
1021 static int
modehelp(int unused)1022 modehelp(int unused)
1023 {
1024     struct modelist *mt;
1025 
1026     printf("format is:  'mode Mode', where 'Mode' is one of:\r\n\r\n");
1027     for (mt = ModeList; mt->name; mt++) {
1028 	if (mt->help) {
1029 	    if (*mt->help)
1030 		printf("%-15s %s\r\n", mt->name, mt->help);
1031 	    else
1032 		printf("\r\n");
1033 	}
1034     }
1035     return 0;
1036 }
1037 
1038 #define	GETMODECMD(name) (struct modelist *) \
1039 		genget(name, (char **) ModeList, sizeof(struct modelist))
1040 
1041 static int
modecmd(int argc,char * argv[])1042 modecmd(int argc, char *argv[])
1043 {
1044     struct modelist *mt;
1045 
1046     if (argc != 2) {
1047 	printf("'mode' command requires an argument\r\n");
1048 	printf("'mode ?' for help.\r\n");
1049     } else if ((mt = GETMODECMD(argv[1])) == 0) {
1050 	fprintf(stderr, "Unknown mode '%s' ('mode ?' for help).\r\n", argv[1]);
1051     } else if (Ambiguous(mt)) {
1052 	fprintf(stderr, "Ambiguous mode '%s' ('mode ?' for help).\r\n", argv[1]);
1053     } else if (mt->needconnect && !connected) {
1054 	printf("?Need to be connected first.\r\n");
1055 	printf("'mode ?' for help.\r\n");
1056     } else if (mt->handler) {
1057 	return (*mt->handler)(mt->arg1);
1058     }
1059     return 0;
1060 }
1061 
1062 /*
1063  * The following data structures and routines implement the
1064  * "display" command.
1065  */
1066 
1067 static int
display(int argc,char * argv[])1068 display(int argc, char *argv[])
1069 {
1070     struct togglelist *tl;
1071     struct setlist *sl;
1072 
1073 #define	dotog(tl)	if (tl->variable && tl->actionexplanation) { \
1074 			    if (*tl->variable) { \
1075 				printf("will"); \
1076 			    } else { \
1077 				printf("won't"); \
1078 			    } \
1079 			    printf(" %s.\r\n", tl->actionexplanation); \
1080 			}
1081 
1082 #define	doset(sl)   if (sl->name && *sl->name != ' ') { \
1083 			if (sl->handler == 0) \
1084 			    printf("%-15s [%s]\r\n", sl->name, control(*sl->charp)); \
1085 			else \
1086 			    printf("%-15s \"%s\"\r\n", sl->name, (char *)sl->charp); \
1087 		    }
1088 
1089     if (argc == 1) {
1090 	for (tl = Togglelist; tl->name; tl++) {
1091 	    dotog(tl);
1092 	}
1093 	printf("\r\n");
1094 	for (sl = Setlist; sl->name; sl++) {
1095 	    doset(sl);
1096 	}
1097     } else {
1098 	int i;
1099 
1100 	for (i = 1; i < argc; i++) {
1101 	    sl = getset(argv[i]);
1102 	    tl = GETTOGGLE(argv[i]);
1103 	    if (Ambiguous(sl) || Ambiguous(tl)) {
1104 		printf("?Ambiguous argument '%s'.\r\n", argv[i]);
1105 		return 0;
1106 	    } else if (!sl && !tl) {
1107 		printf("?Unknown argument '%s'.\r\n", argv[i]);
1108 		return 0;
1109 	    } else {
1110 		if (tl) {
1111 		    dotog(tl);
1112 		}
1113 		if (sl) {
1114 		    doset(sl);
1115 		}
1116 	    }
1117 	}
1118     }
1119 /*@*/optionstatus();
1120     return 1;
1121 #undef	doset
1122 #undef	dotog
1123 }
1124 
1125 /*
1126  * The following are the data structures, and many of the routines,
1127  * relating to command processing.
1128  */
1129 
1130 /*
1131  * Set the escape character.
1132  */
1133 static int
setescape(int argc,char * argv[])1134 setescape(int argc, char *argv[])
1135 {
1136 	char *arg;
1137 	char buf[50];
1138 
1139 	printf(
1140 	    "Deprecated usage - please use 'set escape%s%s' in the future.\r\n",
1141 				(argc > 2)? " ":"", (argc > 2)? argv[1]: "");
1142 	if (argc > 2)
1143 		arg = argv[1];
1144 	else {
1145 		printf("new escape character: ");
1146 		(void) fgets(buf, sizeof(buf), stdin);
1147 		arg = buf;
1148 	}
1149 	if (arg[0] != '\0')
1150 		escape = arg[0];
1151 	printf("Escape character is '%s'.\r\n", control(escape));
1152 	(void) fflush(stdout);
1153 	return 1;
1154 }
1155 
1156 static int
togcrmod(int unused1,char * unused2[])1157 togcrmod(int unused1, char *unused2[])
1158 {
1159     crmod = !crmod;
1160     printf("Deprecated usage - please use 'toggle crmod' in the future.\r\n");
1161     printf("%s map carriage return on output.\r\n", crmod ? "Will" : "Won't");
1162     (void) fflush(stdout);
1163     return 1;
1164 }
1165 
1166 int
telnetsuspend(int unused1,char * unused2[])1167 telnetsuspend(int unused1, char *unused2[])
1168 {
1169     setcommandmode();
1170     {
1171 	long oldrows, oldcols, newrows, newcols, err;
1172 
1173 	err = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
1174 	(void) kill(0, SIGTSTP);
1175 	/*
1176 	 * If we didn't get the window size before the SUSPEND, but we
1177 	 * can get them now (?), then send the NAWS to make sure that
1178 	 * we are set up for the right window size.
1179 	 */
1180 	if (TerminalWindowSize(&newrows, &newcols) && connected &&
1181 	    (err || ((oldrows != newrows) || (oldcols != newcols)))) {
1182 		sendnaws();
1183 	}
1184     }
1185     /* reget parameters in case they were changed */
1186     TerminalSaveState();
1187     setconnmode(0);
1188     return 1;
1189 }
1190 
1191 static void
close_connection(void)1192 close_connection(void)
1193 {
1194 	if (connected) {
1195 		(void) shutdown(net, SHUT_RDWR);
1196 		printf("Connection closed.\r\n");
1197 		(void)close(net);
1198 		connected = 0;
1199 		resettermname = 1;
1200 		/* reset options */
1201 		tninit();
1202 	}
1203 }
1204 
1205 static int
bye(int argc,char * argv[])1206 bye(int argc, char *argv[])
1207 {
1208 	close_connection();
1209 	longjmp(toplevel, 1);
1210 }
1211 
1212 void
quit(void)1213 quit(void)
1214 {
1215 	close_connection();
1216 	Exit(0);
1217 }
1218 
1219 static int
quitcmd(int unused1,char * unused2[])1220 quitcmd(int unused1, char *unused2[])
1221 {
1222 	quit();
1223 }
1224 
1225 static int
logout(int unused1,char * unused2[])1226 logout(int unused1, char *unused2[])
1227 {
1228 	send_do(TELOPT_LOGOUT, 1);
1229 	(void) netflush();
1230 	return 1;
1231 }
1232 
1233 
1234 /*
1235  * The SLC command.
1236  */
1237 
1238 struct slclist {
1239 	char	*name;
1240 	char	*help;
1241 	void	(*handler)(int);
1242 	int	arg;
1243 };
1244 
1245 static void slc_help(int);
1246 
1247 struct slclist SlcList[] = {
1248     { "export",	"Use local special character definitions",
1249 						slc_mode_export,	0 },
1250     { "import",	"Use remote special character definitions",
1251 						slc_mode_import,	1 },
1252     { "check",	"Verify remote special character definitions",
1253 						slc_mode_import,	0 },
1254     { "help",	0,				slc_help,		0 },
1255     { "?",	"Print help information",	slc_help,		0 },
1256     { 0 },
1257 };
1258 
1259 static void
slc_help(int unused)1260 slc_help(int unused)
1261 {
1262     struct slclist *c;
1263 
1264     for (c = SlcList; c->name; c++) {
1265 	if (c->help) {
1266 	    if (*c->help)
1267 		printf("%-15s %s\r\n", c->name, c->help);
1268 	    else
1269 		printf("\r\n");
1270 	}
1271     }
1272 }
1273 
1274 static struct slclist *
getslc(char * name)1275 getslc(char *name)
1276 {
1277     return (struct slclist *)
1278 		genget(name, (char **) SlcList, sizeof(struct slclist));
1279 }
1280 
1281 static int
slccmd(int argc,char * argv[])1282 slccmd(int argc, char *argv[])
1283 {
1284     struct slclist *c;
1285 
1286     if (argc != 2) {
1287 	fprintf(stderr,
1288 	    "Need an argument to 'slc' command.  'slc ?' for help.\r\n");
1289 	return 0;
1290     }
1291     c = getslc(argv[1]);
1292     if (c == 0) {
1293 	fprintf(stderr, "'%s': unknown argument ('slc ?' for help).\r\n",
1294     				argv[1]);
1295 	return 0;
1296     }
1297     if (Ambiguous(c)) {
1298 	fprintf(stderr, "'%s': ambiguous argument ('slc ?' for help).\r\n",
1299     				argv[1]);
1300 	return 0;
1301     }
1302     (*c->handler)(c->arg);
1303     slcstate();
1304     return 1;
1305 }
1306 
1307 /*
1308  * The ENVIRON command.
1309  */
1310 
1311 struct envlist {
1312 	char	*name;
1313 	char	*help;
1314 	void	(*handler)();
1315 	int	narg;
1316 };
1317 
1318 static void	env_help(void);
1319 static void	env_undefine(const char *);
1320 static void	env_export(const char *);
1321 static void	env_unexport(const char *);
1322 static void	env_send(const char *);
1323 static void	env_list(void);
1324 static struct env_lst *env_find(const char *var);
1325 
1326 struct envlist EnvList[] = {
1327     { "define",	"Define an environment variable",
1328 						(void (*)())env_define,	2 },
1329     { "undefine", "Undefine an environment variable",
1330 						env_undefine,	1 },
1331     { "export",	"Mark an environment variable for automatic export",
1332 						env_export,	1 },
1333     { "unexport", "Don't mark an environment variable for automatic export",
1334 						env_unexport,	1 },
1335     { "send",	"Send an environment variable", env_send,	1 },
1336     { "list",	"List the current environment variables",
1337 						env_list,	0 },
1338     { "help",	0,				env_help,		0 },
1339     { "?",	"Print help information",	env_help,		0 },
1340     { 0 },
1341 };
1342 
1343 static void
env_help(void)1344 env_help(void)
1345 {
1346     struct envlist *c;
1347 
1348     for (c = EnvList; c->name; c++) {
1349 	if (c->help) {
1350 	    if (*c->help)
1351 		printf("%-15s %s\r\n", c->name, c->help);
1352 	    else
1353 		printf("\r\n");
1354 	}
1355     }
1356 }
1357 
1358 static struct envlist *
getenvcmd(char * name)1359 getenvcmd(char *name)
1360 {
1361     return (struct envlist *)
1362 		genget(name, (char **) EnvList, sizeof(struct envlist));
1363 }
1364 
1365 static int
env_cmd(int argc,char * argv[])1366 env_cmd(int argc, char *argv[])
1367 {
1368     struct envlist *c;
1369 
1370     if (argc < 2) {
1371 	fprintf(stderr,
1372 	    "Need an argument to 'environ' command.  'environ ?' for help.\r\n");
1373 	return 0;
1374     }
1375     c = getenvcmd(argv[1]);
1376     if (c == 0) {
1377 	fprintf(stderr, "'%s': unknown argument ('environ ?' for help).\r\n",
1378     				argv[1]);
1379 	return 0;
1380     }
1381     if (Ambiguous(c)) {
1382 	fprintf(stderr, "'%s': ambiguous argument ('environ ?' for help).\r\n",
1383     				argv[1]);
1384 	return 0;
1385     }
1386     if (c->narg + 2 != argc) {
1387 	fprintf(stderr,
1388 	    "Need %s%d argument%s to 'environ %s' command.  'environ ?' for help.\r\n",
1389 		c->narg < argc + 2 ? "only " : "",
1390 		c->narg, c->narg == 1 ? "" : "s", c->name);
1391 	return 0;
1392     }
1393     (*c->handler)(argv[2], argv[3]);
1394     return 1;
1395 }
1396 
1397 struct env_lst {
1398 	struct env_lst *next;	/* pointer to next structure */
1399 	struct env_lst *prev;	/* pointer to previous structure */
1400 	char *var;		/* pointer to variable name */
1401 	char *value;		/* pointer to variable value */
1402 	int export;		/* 1 -> export with default list of variables */
1403 	int welldefined;	/* A well defined variable */
1404 };
1405 
1406 struct env_lst envlisthead;
1407 
1408 static struct env_lst *
env_find(const char * var)1409 env_find(const char *var)
1410 {
1411 	struct env_lst *ep;
1412 
1413 	for (ep = envlisthead.next; ep; ep = ep->next) {
1414 		if (strcmp(ep->var, var) == 0)
1415 			return(ep);
1416 	}
1417 	return(NULL);
1418 }
1419 
1420 void
env_init(void)1421 env_init(void)
1422 {
1423 	extern char **environ;
1424 	char **epp, *cp;
1425 	struct env_lst *ep;
1426 
1427 	for (epp = environ; *epp; epp++) {
1428 		if ((cp = strchr(*epp, '='))) {
1429 			*cp = '\0';
1430 			ep = env_define(*epp, cp+1);
1431 			ep->export = 0;
1432 			*cp = '=';
1433 		}
1434 	}
1435 	/*
1436 	 * Special case for DISPLAY variable.  If it is ":0.0" or
1437 	 * "unix:0.0", we have to get rid of "unix" and insert our
1438 	 * hostname.
1439 	 */
1440 	if ((ep = env_find("DISPLAY"))
1441 	    && ((*ep->value == ':')
1442 		|| (strncmp(ep->value, "unix:", 5) == 0))) {
1443 		char hbuf[HOST_NAME_MAX+1];
1444 		char *cp2 = strchr(ep->value, ':');
1445 
1446 		gethostname(hbuf, sizeof hbuf);
1447 
1448 		if (asprintf (&cp, "%s%s", hbuf, cp2) == -1)
1449 			err(1, "asprintf");
1450 
1451 		free(ep->value);
1452 		ep->value = cp;
1453 	}
1454 	/*
1455 	 * If USER is not defined, but LOGNAME is, then add
1456 	 * USER with the value from LOGNAME.  By default, we
1457 	 * don't export the USER variable.
1458 	 */
1459 	if ((env_find("USER") == NULL) && (ep = env_find("LOGNAME"))) {
1460 		env_define("USER", ep->value);
1461 		env_unexport("USER");
1462 	}
1463 	env_export("DISPLAY");
1464 	env_export("PRINTER");
1465 	env_export("XAUTHORITY");
1466 }
1467 
1468 struct env_lst *
env_define(const char * var,const char * value)1469 env_define(const char *var, const char *value)
1470 {
1471 	struct env_lst *ep;
1472 
1473 	if ((ep = env_find(var))) {
1474 		free(ep->var);
1475 		free(ep->value);
1476 	} else {
1477 		if ((ep = malloc(sizeof(struct env_lst))) == NULL)
1478 			err(1, "malloc");
1479 		ep->next = envlisthead.next;
1480 		envlisthead.next = ep;
1481 		ep->prev = &envlisthead;
1482 		if (ep->next)
1483 			ep->next->prev = ep;
1484 	}
1485 	ep->welldefined = opt_welldefined(var);
1486 	ep->export = 1;
1487 	if ((ep->var = strdup(var)) == NULL)
1488 		err(1, "strdup");
1489 	if ((ep->value = strdup(value)) == NULL)
1490 		err(1, "strdup");
1491 	return(ep);
1492 }
1493 
1494 static void
env_undefine(const char * var)1495 env_undefine(const char *var)
1496 {
1497 	struct env_lst *ep;
1498 
1499 	if ((ep = env_find(var))) {
1500 		ep->prev->next = ep->next;
1501 		if (ep->next)
1502 			ep->next->prev = ep->prev;
1503 		free(ep->var);
1504 		free(ep->value);
1505 		free(ep);
1506 	}
1507 }
1508 
1509 static void
env_export(const char * var)1510 env_export(const char *var)
1511 {
1512 	struct env_lst *ep;
1513 
1514 	if ((ep = env_find(var)))
1515 		ep->export = 1;
1516 }
1517 
1518 static void
env_unexport(const char * var)1519 env_unexport(const char *var)
1520 {
1521 	struct env_lst *ep;
1522 
1523 	if ((ep = env_find(var)) != NULL)
1524 		ep->export = 0;
1525 }
1526 
1527 static void
env_send(const char * var)1528 env_send(const char *var)
1529 {
1530 	struct env_lst *ep;
1531 
1532 	if (my_state_is_wont(TELOPT_NEW_ENVIRON)
1533 		) {
1534 		fprintf(stderr,
1535 		    "Cannot send '%s': Telnet ENVIRON option not enabled\r\n",
1536 									var);
1537 		return;
1538 	}
1539 	ep = env_find(var);
1540 	if (ep == 0) {
1541 		fprintf(stderr, "Cannot send '%s': variable not defined\r\n",
1542 									var);
1543 		return;
1544 	}
1545 	env_opt_start_info();
1546 	env_opt_add(ep->var);
1547 	env_opt_end(0);
1548 }
1549 
1550 static void
env_list(void)1551 env_list(void)
1552 {
1553 	struct env_lst *ep;
1554 
1555 	for (ep = envlisthead.next; ep; ep = ep->next) {
1556 		printf("%c %-20s %s\r\n", ep->export ? '*' : ' ',
1557 					ep->var, ep->value);
1558 	}
1559 }
1560 
1561 char *
env_default(int init,int welldefined)1562 env_default(int init, int welldefined)
1563 {
1564 	static struct env_lst *nep = NULL;
1565 
1566 	if (init) {
1567 		nep = &envlisthead;
1568 		return NULL;
1569 	}
1570 	if (nep) {
1571 		while ((nep = nep->next)) {
1572 			if (nep->export && (nep->welldefined == welldefined))
1573 				return(nep->var);
1574 		}
1575 	}
1576 	return(NULL);
1577 }
1578 
1579 char *
env_getvalue(const char * var,int exported_only)1580 env_getvalue(const char *var, int exported_only)
1581 {
1582 	struct env_lst *ep;
1583 
1584 	if ((ep = env_find(var)) && (!exported_only || ep->export))
1585 		return(ep->value);
1586 	return(NULL);
1587 }
1588 
1589 static void
connection_status(int local_only)1590 connection_status(int local_only)
1591 {
1592 	if (!connected)
1593 		printf("No connection.\r\n");
1594 	else {
1595 		printf("Connected to %s.\r\n", hostname);
1596 		if (!local_only) {
1597 			int mode = getconnmode();
1598 
1599 			printf("Operating ");
1600 			if (my_want_state_is_will(TELOPT_LINEMODE)) {
1601 				printf("with LINEMODE option\r\n"
1602 				    "%s line editing\r\n"
1603 				    "%s catching of signals\r\n",
1604 				    (mode & MODE_EDIT) ? "Local" : "No",
1605 				    (mode & MODE_TRAPSIG) ? "Local" : "No");
1606 				slcstate();
1607 #ifdef	KLUDGELINEMODE
1608 			} else if (kludgelinemode &&
1609 			    my_want_state_is_dont(TELOPT_SGA)) {
1610 				printf("in obsolete linemode\r\n");
1611 #endif
1612 			} else {
1613 				printf("in single character mode\r\n");
1614 				if (localchars)
1615 					printf("Catching signals locally\r\n");
1616 			}
1617 
1618 			printf("%s character echo\r\n",
1619 			    (mode & MODE_ECHO) ? "Local" : "Remote");
1620 			if (my_want_state_is_will(TELOPT_LFLOW))
1621 				printf("%s flow control\r\n",
1622 				    (mode & MODE_FLOW) ? "Local" : "No");
1623 		}
1624 	}
1625 	printf("Escape character is '%s'.\r\n", control(escape));
1626 	(void) fflush(stdout);
1627 }
1628 
1629 /*
1630  * Print status about the connection.
1631  */
1632 static int
status(int argc,char * argv[])1633 status(int argc, char *argv[])
1634 {
1635 	connection_status(0);
1636 	return 1;
1637 }
1638 
1639 /*
1640  * Function that gets called when SIGINFO is received.
1641  */
1642 void
ayt_status(int sig)1643 ayt_status(int sig)
1644 {
1645 	connection_status(1);
1646 }
1647 
1648 static Command *getcmd(char *name);
1649 
1650 static void
cmdrc(char * m1,char * m2)1651 cmdrc(char *m1, char *m2)
1652 {
1653     static char rcname[128];
1654     Command *c;
1655     FILE *rcfile;
1656     int gotmachine = 0;
1657     int l1 = strlen(m1);
1658     int l2 = strlen(m2);
1659     char m1save[HOST_NAME_MAX+1];
1660 
1661     if (skiprc)
1662 	return;
1663 
1664     strlcpy(m1save, m1, sizeof(m1save));
1665     m1 = m1save;
1666 
1667     if (rcname[0] == 0) {
1668 	char *home = getenv("HOME");
1669 
1670 	if (home == NULL || *home == '\0')
1671 	    return;
1672 	snprintf (rcname, sizeof(rcname), "%s/.telnetrc",
1673 		  home ? home : "");
1674     }
1675 
1676     if ((rcfile = fopen(rcname, "r")) == 0) {
1677 	return;
1678     }
1679 
1680     for (;;) {
1681 	if (fgets(line, sizeof(line), rcfile) == NULL)
1682 	    break;
1683 	if (line[0] == 0)
1684 	    break;
1685 	if (line[0] == '#')
1686 	    continue;
1687 	if (gotmachine) {
1688 	    if (!isspace((unsigned char)line[0]))
1689 		gotmachine = 0;
1690 	}
1691 	if (gotmachine == 0) {
1692 	    if (isspace((unsigned char)line[0]))
1693 		continue;
1694 	    if (strncasecmp(line, m1, l1) == 0)
1695 		strncpy(line, &line[l1], sizeof(line) - l1);
1696 	    else if (strncasecmp(line, m2, l2) == 0)
1697 		strncpy(line, &line[l2], sizeof(line) - l2);
1698 	    else if (strncasecmp(line, "DEFAULT", 7) == 0)
1699 		strncpy(line, &line[7], sizeof(line) - 7);
1700 	    else
1701 		continue;
1702 	    if (line[0] != ' ' && line[0] != '\t' && line[0] != '\n')
1703 		continue;
1704 	    gotmachine = 1;
1705 	}
1706 	if (makeargv())
1707 	    continue;
1708 	if (margv[0] == 0)
1709 	    continue;
1710 	c = getcmd(margv[0]);
1711 	if (Ambiguous(c)) {
1712 	    printf("?Ambiguous command: %s\r\n", margv[0]);
1713 	    continue;
1714 	}
1715 	if (c == 0) {
1716 	    printf("?Invalid command: %s\r\n", margv[0]);
1717 	    continue;
1718 	}
1719 	/*
1720 	 * This should never happen...
1721 	 */
1722 	if (c->needconnect && !connected) {
1723 	    printf("?Need to be connected first for %s.\r\n", margv[0]);
1724 	    continue;
1725 	}
1726 	(*c->handler)(margc, margv);
1727     }
1728     fclose(rcfile);
1729 }
1730 
1731 int
tn(int argc,char * argv[])1732 tn(int argc, char *argv[])
1733 {
1734     struct addrinfo hints, *res, *res0;
1735     char *cmd, *hostp = 0, *portp = 0, *user = 0, *aliasp = 0;
1736     int error, retry;
1737     const int niflags = NI_NUMERICHOST, tos = IPTOS_LOWDELAY;
1738 
1739     if (connected) {
1740 	printf("?Already connected to %s\r\n", hostname);
1741 	return 0;
1742     }
1743     if (connections) {
1744 	printf("Repeated connections not supported\r\n");
1745 	return 0;
1746     }
1747     if (argc < 2) {
1748 	strlcpy(line, "open ", sizeof(line));
1749 	printf("(to) ");
1750 	(void) fgets(&line[strlen(line)], sizeof(line) - strlen(line), stdin);
1751 	if (makeargv())
1752             return 0;
1753 	argc = margc;
1754 	argv = margv;
1755     }
1756     cmd = *argv;
1757     --argc; ++argv;
1758     while (argc) {
1759 	if (strcmp(*argv, "help") == 0 || isprefix(*argv, "?"))
1760 	    goto usage;
1761 	if (strcmp(*argv, "-l") == 0) {
1762 	    --argc; ++argv;
1763 	    if (argc == 0)
1764 		goto usage;
1765 	    if ((user = strdup(*argv++)) == NULL)
1766 		err(1, "strdup");
1767 	    --argc;
1768 	    continue;
1769 	}
1770 	if (strcmp(*argv, "-b") == 0) {
1771 	    --argc; ++argv;
1772 	    if (argc == 0)
1773 		goto usage;
1774 	    aliasp = *argv++;
1775 	    --argc;
1776 	    continue;
1777 	}
1778 	if (strcmp(*argv, "-a") == 0) {
1779 	    --argc; ++argv;
1780 	    autologin = 1;
1781 	    continue;
1782 	}
1783 	if (hostp == 0) {
1784 	    hostp = *argv++;
1785 	    --argc;
1786 	    continue;
1787 	}
1788 	if (portp == 0) {
1789 	    portp = *argv++;
1790 	    --argc;
1791 	    continue;
1792 	}
1793     usage:
1794 	printf("usage: %s [-a] [-b hostalias] [-l user] host-name [port]\r\n", cmd);
1795 	return 0;
1796     }
1797     if (hostp == 0)
1798 	goto usage;
1799 
1800     hostname = hostp;
1801     memset(&hints, 0, sizeof(hints));
1802     hints.ai_family = family;
1803     hints.ai_socktype = SOCK_STREAM;
1804     hints.ai_flags = AI_CANONNAME;
1805     if (portp == NULL) {
1806         portp = "telnet";
1807         telnetport = 1;
1808     } else if (*portp == '-') {
1809         portp++;
1810         telnetport = 1;
1811     } else
1812         telnetport = 0;
1813     error = getaddrinfo(hostp, portp, &hints, &res0);
1814     if (error) {
1815         if (error == EAI_SERVICE)
1816             warnx("%s: bad port", portp);
1817         else
1818             warnx("%s: %s", hostp, gai_strerror(error));
1819         return 0;
1820     }
1821 
1822     net = -1;
1823     retry = 0;
1824     for (res = res0; res; res = res->ai_next) {
1825 	if (1 /* retry */) {
1826 	    char hbuf[NI_MAXHOST];
1827 
1828 	    if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf),
1829 		    NULL, 0, niflags) != 0) {
1830 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
1831 	    }
1832 	    printf("Trying %s...\r\n", hbuf);
1833 	}
1834 	net = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
1835 	if (net == -1)
1836 	    continue;
1837 
1838 	if (aliasp) {
1839 	    struct addrinfo ahints, *ares;
1840 
1841 	    memset(&ahints, 0, sizeof(ahints));
1842 	    ahints.ai_family = family;
1843 	    ahints.ai_socktype = SOCK_STREAM;
1844 	    ahints.ai_flags = AI_PASSIVE;
1845 	    error = getaddrinfo(aliasp, "0", &ahints, &ares);
1846 	    if (error) {
1847 		warn("%s: %s", aliasp, gai_strerror(error));
1848 		close(net);
1849 		net = -1;
1850 		continue;
1851 	    }
1852 	    if (bind(net, ares->ai_addr, ares->ai_addrlen) == -1) {
1853 		perror(aliasp);
1854 		(void) close(net);   /* dump descriptor */
1855 		net = -1;
1856 		freeaddrinfo(ares);
1857 		continue;
1858             }
1859 	    freeaddrinfo(ares);
1860 	}
1861 
1862 	switch (res->ai_family) {
1863 	case AF_INET:
1864 		if (setsockopt(net, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1
1865 		    && errno != ENOPROTOOPT)
1866 			perror("telnet: setsockopt (IP_TOS) (ignored)");
1867 		break;
1868 	case AF_INET6:
1869 		if (setsockopt(net, IPPROTO_IPV6, IPV6_TCLASS, &tos,
1870 		    sizeof(tos)) == -1 && errno != ENOPROTOOPT)
1871 			perror("telnet: setsockopt (IPV6_TCLASS) (ignored)");
1872 		break;
1873 	}
1874 
1875 	if (connect(net, res->ai_addr, res->ai_addrlen) == -1) {
1876 	    char hbuf[NI_MAXHOST];
1877 
1878 	    if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf),
1879 		    NULL, 0, niflags) != 0) {
1880 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
1881 	    }
1882 	    fprintf(stderr, "telnet: connect to address %s: %s\n", hbuf,
1883 		strerror(errno));
1884 
1885 	    close(net);
1886 	    net = -1;
1887 	    retry++;
1888 	    continue;
1889 	}
1890 
1891 	connected++;
1892 	break;
1893     }
1894     freeaddrinfo(res0);
1895     if (net < 0) {
1896 	return 0;
1897     }
1898     cmdrc(hostp, hostname);
1899     if (autologin && user == NULL) {
1900 	struct passwd *pw;
1901 
1902 	user = getlogin();
1903 	if (user == NULL ||
1904 	    (pw = getpwnam(user)) == NULL || pw->pw_uid != getuid()) {
1905 		if ((pw = getpwuid(getuid())) != NULL)
1906 			user = pw->pw_name;
1907 		else
1908 			user = NULL;
1909 	}
1910     }
1911     if (user) {
1912 	env_define("USER", user);
1913 	env_export("USER");
1914     }
1915     connection_status(1);
1916     if (setjmp(peerdied) == 0)
1917 	telnet(user);
1918     (void)close(net);
1919     ExitString("Connection closed by foreign host.\r\n",1);
1920 }
1921 
1922 #define HELPINDENT (sizeof ("connect"))
1923 
1924 static char
1925 	openhelp[] =	"connect to a site",
1926 	closehelp[] =	"close current connection",
1927 	logouthelp[] =	"forcibly logout remote user and close the connection",
1928 	quithelp[] =	"exit telnet",
1929 	statushelp[] =	"print status information",
1930 	helphelp[] =	"print help information",
1931 	sendhelp[] =	"transmit special characters ('send ?' for more)",
1932 	sethelp[] = 	"set operating parameters ('set ?' for more)",
1933 	unsethelp[] = 	"unset operating parameters ('unset ?' for more)",
1934 	togglestring[] ="toggle operating parameters ('toggle ?' for more)",
1935 	slchelp[] =	"change state of special characters ('slc ?' for more)",
1936 	displayhelp[] =	"display operating parameters",
1937 	zhelp[] =	"suspend telnet",
1938 	envhelp[] =	"change environment variables ('environ ?' for more)",
1939 	modestring[] = "try to enter line or character mode ('mode ?' for more)";
1940 
1941 static int	help(int, char**);
1942 
1943 static Command cmdtab[] = {
1944 	{ "close",	closehelp,	bye,		1 },
1945 	{ "logout",	logouthelp,	logout,		1 },
1946 	{ "display",	displayhelp,	display,	0 },
1947 	{ "mode",	modestring,	modecmd,	0 },
1948 	{ "open",	openhelp,	tn,		0 },
1949 	{ "quit",	quithelp,	quitcmd,	0 },
1950 	{ "send",	sendhelp,	sendcmd,	0 },
1951 	{ "set",	sethelp,	setcmd,		0 },
1952 	{ "unset",	unsethelp,	unsetcmd,	0 },
1953 	{ "status",	statushelp,	status,		0 },
1954 	{ "toggle",	togglestring,	toggle,		0 },
1955 	{ "slc",	slchelp,	slccmd,		0 },
1956 
1957 	{ "z",		zhelp,		telnetsuspend,	0 },
1958 	{ "environ",	envhelp,	env_cmd,	0 },
1959 	{ "?",		helphelp,	help,		0 },
1960 	{ 0,		0,		0,		0 }
1961 };
1962 
1963 static char	crmodhelp[] =	"deprecated command -- use 'toggle crmod' instead";
1964 static char	escapehelp[] =	"deprecated command -- use 'set escape' instead";
1965 
1966 static Command cmdtab2[] = {
1967 	{ "help",	0,		help,		0 },
1968 	{ "escape",	escapehelp,	setescape,	0 },
1969 	{ "crmod",	crmodhelp,	togcrmod,	0 },
1970 	{ 0,		0,		0,		0 }
1971 };
1972 
1973 
1974 static Command *
getcmd(char * name)1975 getcmd(char *name)
1976 {
1977     Command *cm;
1978 
1979     if ((cm = (Command *) genget(name, (char **) cmdtab, sizeof(Command))))
1980 	return cm;
1981     return (Command *) genget(name, (char **) cmdtab2, sizeof(Command));
1982 }
1983 
1984 void
command(int top,char * tbuf,int cnt)1985 command(int top, char *tbuf, int cnt)
1986 {
1987     Command *c;
1988 
1989     setcommandmode();
1990     if (!top) {
1991 	putchar('\n');
1992     } else {
1993 	(void) signal(SIGINT, SIG_DFL);
1994 	(void) signal(SIGQUIT, SIG_DFL);
1995     }
1996     for (;;) {
1997 	if (rlogin == _POSIX_VDISABLE)
1998 		printf("%s> ", prompt);
1999 	if (tbuf) {
2000 	    char *cp;
2001 	    cp = line;
2002 	    while (cnt > 0 && (*cp++ = *tbuf++) != '\n')
2003 		cnt--;
2004 	    tbuf = 0;
2005 	    if (cp == line || *--cp != '\n' || cp == line)
2006 		goto getline;
2007 	    *cp = '\0';
2008 	    if (rlogin == _POSIX_VDISABLE)
2009 		printf("%s\r\n", line);
2010 	} else {
2011 	getline:
2012 	    if (rlogin != _POSIX_VDISABLE)
2013 		printf("%s> ", prompt);
2014 	    if (fgets(line, sizeof(line), stdin) == NULL) {
2015 		if (feof(stdin) || ferror(stdin))
2016 		    quit();
2017 		break;
2018 	    }
2019 	}
2020 	if (line[0] == 0)
2021 	    break;
2022 	if (makeargv())
2023             break;
2024 	if (margv[0] == 0) {
2025 	    break;
2026 	}
2027 	c = getcmd(margv[0]);
2028 	if (Ambiguous(c)) {
2029 	    printf("?Ambiguous command\r\n");
2030 	    continue;
2031 	}
2032 	if (c == 0) {
2033 	    printf("?Invalid command\r\n");
2034 	    continue;
2035 	}
2036 	if (c->needconnect && !connected) {
2037 	    printf("?Need to be connected first.\r\n");
2038 	    continue;
2039 	}
2040 	if ((*c->handler)(margc, margv)) {
2041 	    break;
2042 	}
2043     }
2044     if (!top) {
2045 	if (!connected)
2046 	    longjmp(toplevel, 1);
2047 	setconnmode(0);
2048     }
2049 }
2050 
2051 /*
2052  * Help command.
2053  */
2054 static int
help(int argc,char * argv[])2055 help(int argc, char *argv[])
2056 {
2057 	Command *c;
2058 
2059 	if (argc == 1) {
2060 		printf("Commands may be abbreviated.  Commands are:\r\n\r\n");
2061 		for (c = cmdtab; c->name; c++)
2062 			if (c->help) {
2063 				printf("%-*s\t%s\r\n", (int)HELPINDENT, c->name,
2064 								    c->help);
2065 			}
2066 		return 0;
2067 	}
2068 	while (--argc > 0) {
2069 		char *arg;
2070 		arg = *++argv;
2071 		c = getcmd(arg);
2072 		if (Ambiguous(c))
2073 			printf("?Ambiguous help command %s\r\n", arg);
2074 		else if (c == NULL)
2075 			printf("?Invalid help command %s\r\n", arg);
2076 		else
2077 			printf("%s\r\n", c->help);
2078 	}
2079 	return 0;
2080 }
2081