1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1991 The Regents of the University of California.
6 * Copyright (c) 1999 Michael Smith
7 * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
8 *
9 * All rights reserved.
10 *
11 * This code is derived from software contributed to Berkeley by
12 * the Systems Programming Group of the University of Utah Computer
13 * Science Department.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * from: @(#)cons.c 7.2 (Berkeley) 5/9/91
40 */
41
42 #include <sys/cdefs.h>
43 #include "opt_ddb.h"
44 #include "opt_syscons.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/conf.h>
51 #include <sys/cons.h>
52 #include <sys/fcntl.h>
53 #include <sys/kbio.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/malloc.h>
57 #include <sys/msgbuf.h>
58 #include <sys/namei.h>
59 #include <sys/priv.h>
60 #include <sys/proc.h>
61 #include <sys/queue.h>
62 #include <sys/reboot.h>
63 #include <sys/sysctl.h>
64 #include <sys/sbuf.h>
65 #include <sys/tty.h>
66 #include <sys/uio.h>
67 #include <sys/vnode.h>
68
69 #include <ddb/ddb.h>
70
71 #include <dev/kbd/kbdreg.h>
72
73 #include <machine/cpu.h>
74 #include <machine/clock.h>
75
76 static MALLOC_DEFINE(M_TTYCONS, "tty console", "tty console handling");
77
78 struct cn_device {
79 STAILQ_ENTRY(cn_device) cnd_next;
80 struct consdev *cnd_cn;
81 };
82
83 #define CNDEVPATHMAX 32
84 #define CNDEVTAB_SIZE 4
85 static struct cn_device cn_devtab[CNDEVTAB_SIZE];
86 static STAILQ_HEAD(, cn_device) cn_devlist =
87 STAILQ_HEAD_INITIALIZER(cn_devlist);
88
89 int cons_avail_mask = 0; /* Bit mask. Each registered low level console
90 * which is currently unavailable for inpit
91 * (i.e., if it is in graphics mode) will have
92 * this bit cleared.
93 */
94
95 static int cn_mute;
96 SYSCTL_INT(_kern, OID_AUTO, consmute, CTLFLAG_RW, &cn_mute, 0,
97 "State of the console muting");
98
99 static char *consbuf; /* buffer used by `consmsgbuf' */
100 static struct callout conscallout; /* callout for outputting to constty */
101 struct msgbuf consmsgbuf; /* message buffer for console tty */
102 static u_char console_pausing; /* pause after each line during probe */
103 static const char console_pausestr[] =
104 "<pause; press any key to proceed to next line or '.' to end pause mode>";
105 struct tty *constty; /* pointer to console "window" tty */
106 static struct mtx constty_mtx; /* Mutex for constty assignment. */
107 MTX_SYSINIT(constty_mtx, &constty_mtx, "constty_mtx", MTX_DEF);
108 static struct mtx cnputs_mtx; /* Mutex for cnputs(). */
109 MTX_SYSINIT(cnputs_mtx, &cnputs_mtx, "cnputs_mtx", MTX_SPIN | MTX_NOWITNESS);
110
111 static void constty_timeout(void *arg);
112
113 static struct consdev cons_consdev;
114 DATA_SET(cons_set, cons_consdev);
115 SET_DECLARE(cons_set, struct consdev);
116
117 /*
118 * Stub for configurations that don't actually have a keyboard driver. Inclusion
119 * of kbd.c is contingent on any number of keyboard/console drivers being
120 * present in the kernel; rather than trying to catch them all, we'll just
121 * maintain this weak kbdinit that will be overridden by the strong version in
122 * kbd.c if it's present.
123 */
124 __weak_symbol void
kbdinit(void)125 kbdinit(void)
126 {
127
128 }
129
130 void
cninit(void)131 cninit(void)
132 {
133 struct consdev *best_cn, *cn, **list;
134
135 /*
136 * Check if we should mute the console (for security reasons perhaps)
137 * It can be changes dynamically using sysctl kern.consmute
138 * once we are up and going.
139 *
140 */
141 cn_mute = ((boothowto & (RB_MUTE
142 |RB_SINGLE
143 |RB_VERBOSE
144 |RB_ASKNAME)) == RB_MUTE);
145
146 /*
147 * Bring up the kbd layer just in time for cnprobe. Console drivers
148 * have a dependency on kbd being ready, so this fits nicely between the
149 * machdep callers of cninit() and MI probing/initialization of consoles
150 * here.
151 */
152 kbdinit();
153
154 /*
155 * Find the first console with the highest priority.
156 */
157 best_cn = NULL;
158 SET_FOREACH(list, cons_set) {
159 cn = *list;
160 cnremove(cn);
161 /* Skip cons_consdev. */
162 if (cn->cn_ops == NULL)
163 continue;
164 cn->cn_ops->cn_probe(cn);
165 if (cn->cn_pri == CN_DEAD)
166 continue;
167 if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri)
168 best_cn = cn;
169 if (boothowto & RB_MULTIPLE) {
170 /*
171 * Initialize console, and attach to it.
172 */
173 cn->cn_ops->cn_init(cn);
174 cnadd(cn);
175 }
176 }
177 if (best_cn == NULL)
178 return;
179 if ((boothowto & RB_MULTIPLE) == 0) {
180 best_cn->cn_ops->cn_init(best_cn);
181 cnadd(best_cn);
182 }
183 if (boothowto & RB_PAUSE)
184 console_pausing = 1;
185 /*
186 * Make the best console the preferred console.
187 */
188 cnselect(best_cn);
189
190 #ifdef EARLY_PRINTF
191 /*
192 * Release early console.
193 */
194 early_putc = NULL;
195 #endif
196 }
197
198 void
cninit_finish(void)199 cninit_finish(void)
200 {
201 console_pausing = 0;
202 }
203
204 /* add a new physical console to back the virtual console */
205 int
cnadd(struct consdev * cn)206 cnadd(struct consdev *cn)
207 {
208 struct cn_device *cnd;
209 int i;
210
211 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
212 if (cnd->cnd_cn == cn)
213 return (0);
214 for (i = 0; i < CNDEVTAB_SIZE; i++) {
215 cnd = &cn_devtab[i];
216 if (cnd->cnd_cn == NULL)
217 break;
218 }
219 if (cnd->cnd_cn != NULL)
220 return (ENOMEM);
221 cnd->cnd_cn = cn;
222 if (cn->cn_name[0] == '\0') {
223 /* XXX: it is unclear if/where this print might output */
224 printf("WARNING: console at %p has no name\n", cn);
225 }
226 STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next);
227 if (STAILQ_FIRST(&cn_devlist) == cnd)
228 ttyconsdev_select(cnd->cnd_cn->cn_name);
229
230 /* Add device to the active mask. */
231 cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0);
232
233 return (0);
234 }
235
236 void
cnremove(struct consdev * cn)237 cnremove(struct consdev *cn)
238 {
239 struct cn_device *cnd;
240 int i;
241
242 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
243 if (cnd->cnd_cn != cn)
244 continue;
245 if (STAILQ_FIRST(&cn_devlist) == cnd)
246 ttyconsdev_select(NULL);
247 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
248 cnd->cnd_cn = NULL;
249
250 /* Remove this device from available mask. */
251 for (i = 0; i < CNDEVTAB_SIZE; i++)
252 if (cnd == &cn_devtab[i]) {
253 cons_avail_mask &= ~(1 << i);
254 break;
255 }
256 #if 0
257 /*
258 * XXX
259 * syscons gets really confused if console resources are
260 * freed after the system has initialized.
261 */
262 if (cn->cn_term != NULL)
263 cn->cn_ops->cn_term(cn);
264 #endif
265 return;
266 }
267 }
268
269 void
cnselect(struct consdev * cn)270 cnselect(struct consdev *cn)
271 {
272 struct cn_device *cnd;
273
274 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
275 if (cnd->cnd_cn != cn)
276 continue;
277 if (cnd == STAILQ_FIRST(&cn_devlist))
278 return;
279 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
280 STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next);
281 ttyconsdev_select(cnd->cnd_cn->cn_name);
282 return;
283 }
284 }
285
286 void
cnavailable(struct consdev * cn,int available)287 cnavailable(struct consdev *cn, int available)
288 {
289 int i;
290
291 for (i = 0; i < CNDEVTAB_SIZE; i++) {
292 if (cn_devtab[i].cnd_cn == cn)
293 break;
294 }
295 if (available) {
296 if (i < CNDEVTAB_SIZE)
297 cons_avail_mask |= (1 << i);
298 cn->cn_flags &= ~CN_FLAG_NOAVAIL;
299 } else {
300 if (i < CNDEVTAB_SIZE)
301 cons_avail_mask &= ~(1 << i);
302 cn->cn_flags |= CN_FLAG_NOAVAIL;
303 }
304 }
305
306 int
cnunavailable(void)307 cnunavailable(void)
308 {
309
310 return (cons_avail_mask == 0);
311 }
312
313 /*
314 * sysctl_kern_console() provides output parseable in conscontrol(1).
315 */
316 static int
sysctl_kern_console(SYSCTL_HANDLER_ARGS)317 sysctl_kern_console(SYSCTL_HANDLER_ARGS)
318 {
319 struct cn_device *cnd;
320 struct consdev *cp, **list;
321 char *p;
322 int delete, error;
323 struct sbuf *sb;
324
325 sb = sbuf_new(NULL, NULL, CNDEVPATHMAX * 2, SBUF_AUTOEXTEND |
326 SBUF_INCLUDENUL);
327 if (sb == NULL)
328 return (ENOMEM);
329 sbuf_clear(sb);
330 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
331 sbuf_printf(sb, "%s,", cnd->cnd_cn->cn_name);
332 sbuf_printf(sb, "/");
333 SET_FOREACH(list, cons_set) {
334 cp = *list;
335 if (cp->cn_name[0] != '\0')
336 sbuf_printf(sb, "%s,", cp->cn_name);
337 }
338 sbuf_finish(sb);
339 error = sysctl_handle_string(oidp, sbuf_data(sb), sbuf_len(sb), req);
340 if (error == 0 && req->newptr != NULL) {
341 p = sbuf_data(sb);
342 error = ENXIO;
343 delete = 0;
344 if (*p == '-') {
345 delete = 1;
346 p++;
347 }
348 SET_FOREACH(list, cons_set) {
349 cp = *list;
350 if (strcmp(p, cp->cn_name) != 0)
351 continue;
352 if (delete) {
353 cnremove(cp);
354 error = 0;
355 } else {
356 error = cnadd(cp);
357 if (error == 0)
358 cnselect(cp);
359 }
360 break;
361 }
362 }
363 sbuf_delete(sb);
364 return (error);
365 }
366
367 SYSCTL_PROC(_kern, OID_AUTO, console,
368 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0,
369 sysctl_kern_console, "A",
370 "Console device control");
371
372 void
cngrab(void)373 cngrab(void)
374 {
375 struct cn_device *cnd;
376 struct consdev *cn;
377
378 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
379 cn = cnd->cnd_cn;
380 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG))
381 cn->cn_ops->cn_grab(cn);
382 }
383 }
384
385 void
cnungrab(void)386 cnungrab(void)
387 {
388 struct cn_device *cnd;
389 struct consdev *cn;
390
391 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
392 cn = cnd->cnd_cn;
393 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG))
394 cn->cn_ops->cn_ungrab(cn);
395 }
396 }
397
398 void
cnresume(void)399 cnresume(void)
400 {
401 struct cn_device *cnd;
402 struct consdev *cn;
403
404 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
405 cn = cnd->cnd_cn;
406 if (cn->cn_ops->cn_resume != NULL)
407 cn->cn_ops->cn_resume(cn);
408 }
409 }
410
411 /*
412 * Low level console routines.
413 */
414 int
cngetc(void)415 cngetc(void)
416 {
417 int c;
418
419 if (cn_mute)
420 return (-1);
421 while ((c = cncheckc()) == -1)
422 cpu_spinwait();
423 if (c == '\r')
424 c = '\n'; /* console input is always ICRNL */
425 return (c);
426 }
427
428 int
cncheckc(void)429 cncheckc(void)
430 {
431 struct cn_device *cnd;
432 struct consdev *cn;
433 int c;
434
435 if (cn_mute)
436 return (-1);
437 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
438 cn = cnd->cnd_cn;
439 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
440 c = cn->cn_ops->cn_getc(cn);
441 if (c != -1)
442 return (c);
443 }
444 }
445 return (-1);
446 }
447
448 void
cngets(char * cp,size_t size,int visible)449 cngets(char *cp, size_t size, int visible)
450 {
451 char *lp, *end;
452 int c;
453
454 cngrab();
455
456 lp = cp;
457 end = cp + size - 1;
458 for (;;) {
459 c = cngetc() & 0177;
460 switch (c) {
461 case '\n':
462 case '\r':
463 cnputc(c);
464 *lp = '\0';
465 cnungrab();
466 return;
467 case '\b':
468 case '\177':
469 if (lp > cp) {
470 if (visible)
471 cnputs("\b \b");
472 lp--;
473 }
474 continue;
475 case '\0':
476 continue;
477 default:
478 if (lp < end) {
479 switch (visible) {
480 case GETS_NOECHO:
481 break;
482 case GETS_ECHOPASS:
483 cnputc('*');
484 break;
485 default:
486 cnputc(c);
487 break;
488 }
489 *lp++ = c;
490 }
491 }
492 }
493 }
494
495 void
cnputc(int c)496 cnputc(int c)
497 {
498 struct cn_device *cnd;
499 struct consdev *cn;
500 const char *cp;
501
502 #ifdef EARLY_PRINTF
503 if (early_putc != NULL) {
504 if (c == '\n')
505 early_putc('\r');
506 early_putc(c);
507 return;
508 }
509 #endif
510
511 if (cn_mute || c == '\0')
512 return;
513 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
514 cn = cnd->cnd_cn;
515 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
516 if (c == '\n')
517 cn->cn_ops->cn_putc(cn, '\r');
518 cn->cn_ops->cn_putc(cn, c);
519 }
520 }
521 if (console_pausing && c == '\n' && !kdb_active) {
522 for (cp = console_pausestr; *cp != '\0'; cp++)
523 cnputc(*cp);
524 cngrab();
525 if (cngetc() == '.')
526 console_pausing = 0;
527 cnungrab();
528 cnputc('\r');
529 for (cp = console_pausestr; *cp != '\0'; cp++)
530 cnputc(' ');
531 cnputc('\r');
532 }
533 }
534
535 void
cnputsn(const char * p,size_t n)536 cnputsn(const char *p, size_t n)
537 {
538 size_t i;
539 int unlock_reqd = 0;
540
541 if (mtx_initialized(&cnputs_mtx)) {
542 /*
543 * NOTE: Debug prints and/or witness printouts in
544 * console driver clients can cause the "cnputs_mtx"
545 * mutex to recurse. Simply return if that happens.
546 */
547 if (mtx_owned(&cnputs_mtx))
548 return;
549 mtx_lock_spin(&cnputs_mtx);
550 unlock_reqd = 1;
551 }
552
553 for (i = 0; i < n; i++)
554 cnputc(p[i]);
555
556 if (unlock_reqd)
557 mtx_unlock_spin(&cnputs_mtx);
558 }
559
560 void
cnputs(const char * p)561 cnputs(const char *p)
562 {
563 cnputsn(p, strlen(p));
564 }
565
566 static unsigned int consmsgbuf_size = 65536;
567 SYSCTL_UINT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RWTUN, &consmsgbuf_size,
568 0, "Console tty buffer size");
569
570 /*
571 * Redirect console output to a tty.
572 */
573 int
constty_set(struct tty * tp)574 constty_set(struct tty *tp)
575 {
576 int size = consmsgbuf_size;
577 void *buf = NULL;
578
579 tty_assert_locked(tp);
580 if (constty == tp)
581 return (0);
582 if (constty != NULL)
583 return (EBUSY);
584
585 if (consbuf == NULL) {
586 tty_unlock(tp);
587 buf = malloc(size, M_TTYCONS, M_WAITOK);
588 tty_lock(tp);
589 }
590 mtx_lock(&constty_mtx);
591 if (constty != NULL) {
592 mtx_unlock(&constty_mtx);
593 free(buf, M_TTYCONS);
594 return (EBUSY);
595 }
596 if (consbuf == NULL) {
597 consbuf = buf;
598 msgbuf_init(&consmsgbuf, buf, size);
599 } else
600 free(buf, M_TTYCONS);
601 constty = tp;
602 mtx_unlock(&constty_mtx);
603
604 callout_init_mtx(&conscallout, tty_getlock(tp), 0);
605 constty_timeout(tp);
606 return (0);
607 }
608
609 /*
610 * Disable console redirection to a tty.
611 */
612 int
constty_clear(struct tty * tp)613 constty_clear(struct tty *tp)
614 {
615 int c;
616
617 tty_assert_locked(tp);
618 if (constty != tp)
619 return (ENXIO);
620 callout_stop(&conscallout);
621 mtx_lock(&constty_mtx);
622 constty = NULL;
623 mtx_unlock(&constty_mtx);
624 while ((c = msgbuf_getchar(&consmsgbuf)) != -1)
625 cnputc(c);
626 /* We never free consbuf because it can still be in use. */
627 return (0);
628 }
629
630 /* Times per second to check for pending console tty messages. */
631 static int constty_wakeups_per_second = 15;
632 SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW,
633 &constty_wakeups_per_second, 0,
634 "Times per second to check for pending console tty messages");
635
636 static void
constty_timeout(void * arg)637 constty_timeout(void *arg)
638 {
639 struct tty *tp = arg;
640 int c;
641
642 tty_assert_locked(tp);
643 while ((c = msgbuf_getchar(&consmsgbuf)) != -1) {
644 if (tty_putchar(tp, c) < 0) {
645 constty_clear(tp);
646 return;
647 }
648 }
649 callout_reset_sbt(&conscallout, SBT_1S / constty_wakeups_per_second,
650 0, constty_timeout, tp, C_PREL(1));
651 }
652
653 /*
654 * Sysbeep(), if we have hardware for it
655 */
656
657 #ifdef HAS_TIMER_SPKR
658
659 static bool beeping;
660 static struct callout beeping_timer;
661
662 static void
sysbeepstop(void * chan)663 sysbeepstop(void *chan)
664 {
665
666 timer_spkr_release();
667 beeping = false;
668 }
669
670 int
sysbeep(int pitch,sbintime_t duration)671 sysbeep(int pitch, sbintime_t duration)
672 {
673
674 if (timer_spkr_acquire()) {
675 if (!beeping) {
676 /* Something else owns it. */
677 return (EBUSY);
678 }
679 }
680 timer_spkr_setfreq(pitch);
681 if (!beeping) {
682 beeping = true;
683 callout_reset_sbt(&beeping_timer, duration, 0, sysbeepstop,
684 NULL, C_PREL(5));
685 }
686 return (0);
687 }
688
689 static void
sysbeep_init(void * unused)690 sysbeep_init(void *unused)
691 {
692
693 callout_init(&beeping_timer, 1);
694 }
695 SYSINIT(sysbeep, SI_SUB_SOFTINTR, SI_ORDER_ANY, sysbeep_init, NULL);
696 #else
697
698 /*
699 * No hardware, no sound
700 */
701
702 int
sysbeep(int pitch __unused,sbintime_t duration __unused)703 sysbeep(int pitch __unused, sbintime_t duration __unused)
704 {
705
706 return (ENODEV);
707 }
708
709 #endif
710
711 /*
712 * Temporary support for sc(4) to vt(4) transition.
713 */
714 static unsigned vty_prefer;
715 static char vty_name[16];
716 SYSCTL_STRING(_kern, OID_AUTO, vty, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, vty_name,
717 0, "Console vty driver");
718
719 int
vty_enabled(unsigned vty)720 vty_enabled(unsigned vty)
721 {
722 static unsigned vty_selected = 0;
723
724 if (vty_selected == 0) {
725 TUNABLE_STR_FETCH("kern.vty", vty_name, sizeof(vty_name));
726 do {
727 #if defined(DEV_SC)
728 if (strcmp(vty_name, "sc") == 0) {
729 vty_selected = VTY_SC;
730 break;
731 }
732 #endif
733 #if defined(DEV_VT)
734 if (strcmp(vty_name, "vt") == 0) {
735 vty_selected = VTY_VT;
736 break;
737 }
738 #endif
739 if (vty_prefer != 0) {
740 vty_selected = vty_prefer;
741 break;
742 }
743 #if defined(DEV_VT)
744 vty_selected = VTY_VT;
745 #elif defined(DEV_SC)
746 vty_selected = VTY_SC;
747 #endif
748 } while (0);
749
750 if (vty_selected == VTY_VT)
751 strcpy(vty_name, "vt");
752 else if (vty_selected == VTY_SC)
753 strcpy(vty_name, "sc");
754 }
755 return ((vty_selected & vty) != 0);
756 }
757
758 void
vty_set_preferred(unsigned vty)759 vty_set_preferred(unsigned vty)
760 {
761
762 vty_prefer = vty;
763 #if !defined(DEV_SC)
764 vty_prefer &= ~VTY_SC;
765 #endif
766 #if !defined(DEV_VT)
767 vty_prefer &= ~VTY_VT;
768 #endif
769 }
770