1/*-
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * Copyright (c) 1999 Michael Smith
5 * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
6 *
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * the Systems Programming Group of the University of Utah Computer
11 * Science Department.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 * 4. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
38 */
39
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD$");
42
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/kdb.h>
54#include <sys/kernel.h>
55#include <sys/malloc.h>
56#include <sys/msgbuf.h>
57#include <sys/namei.h>
58#include <sys/priv.h>
59#include <sys/proc.h>
60#include <sys/queue.h>
61#include <sys/reboot.h>
62#include <sys/sysctl.h>
63#include <sys/sbuf.h>
64#include <sys/tty.h>
65#include <sys/uio.h>
66#include <sys/vnode.h>
67
68#include <ddb/ddb.h>
69
70#include <machine/cpu.h>
71#include <machine/clock.h>
72
73static MALLOC_DEFINE(M_TTYCONS, "tty console", "tty console handling");
74
75struct cn_device {
76	STAILQ_ENTRY(cn_device) cnd_next;
77	struct		consdev *cnd_cn;
78};
79
80#define CNDEVPATHMAX	32
81#define CNDEVTAB_SIZE	4
82static struct cn_device cn_devtab[CNDEVTAB_SIZE];
83static STAILQ_HEAD(, cn_device) cn_devlist =
84    STAILQ_HEAD_INITIALIZER(cn_devlist);
85
86int	cons_avail_mask = 0;	/* Bit mask. Each registered low level console
87				 * which is currently unavailable for inpit
88				 * (i.e., if it is in graphics mode) will have
89				 * this bit cleared.
90				 */
91static int cn_mute;
92static char *consbuf;			/* buffer used by `consmsgbuf' */
93static struct callout conscallout;	/* callout for outputting to constty */
94struct msgbuf consmsgbuf;		/* message buffer for console tty */
95static u_char console_pausing;		/* pause after each line during probe */
96static char *console_pausestr=
97"<pause; press any key to proceed to next line or '.' to end pause mode>";
98struct tty *constty;			/* pointer to console "window" tty */
99static struct mtx cnputs_mtx;		/* Mutex for cnputs(). */
100static int use_cnputs_mtx = 0;		/* != 0 if cnputs_mtx locking reqd. */
101
102static void constty_timeout(void *arg);
103
104static struct consdev cons_consdev;
105DATA_SET(cons_set, cons_consdev);
106SET_DECLARE(cons_set, struct consdev);
107
108void
109cninit(void)
110{
111	struct consdev *best_cn, *cn, **list;
112
113	/*
114	 * Check if we should mute the console (for security reasons perhaps)
115	 * It can be changes dynamically using sysctl kern.consmute
116	 * once we are up and going.
117	 *
118	 */
119        cn_mute = ((boothowto & (RB_MUTE
120			|RB_SINGLE
121			|RB_VERBOSE
122			|RB_ASKNAME)) == RB_MUTE);
123
124	/*
125	 * Find the first console with the highest priority.
126	 */
127	best_cn = NULL;
128	SET_FOREACH(list, cons_set) {
129		cn = *list;
130		cnremove(cn);
131		/* Skip cons_consdev. */
132		if (cn->cn_ops == NULL)
133			continue;
134		cn->cn_ops->cn_probe(cn);
135		if (cn->cn_pri == CN_DEAD)
136			continue;
137		if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri)
138			best_cn = cn;
139		if (boothowto & RB_MULTIPLE) {
140			/*
141			 * Initialize console, and attach to it.
142			 */
143			cn->cn_ops->cn_init(cn);
144			cnadd(cn);
145		}
146	}
147	if (best_cn == NULL)
148		return;
149	if ((boothowto & RB_MULTIPLE) == 0) {
150		best_cn->cn_ops->cn_init(best_cn);
151		cnadd(best_cn);
152	}
153	if (boothowto & RB_PAUSE)
154		console_pausing = 1;
155	/*
156	 * Make the best console the preferred console.
157	 */
158	cnselect(best_cn);
159
160#ifdef EARLY_PRINTF
161	/*
162	 * Release early console.
163	 */
164	early_putc = NULL;
165#endif
166}
167
168void
169cninit_finish()
170{
171	console_pausing = 0;
172}
173
174/* add a new physical console to back the virtual console */
175int
176cnadd(struct consdev *cn)
177{
178	struct cn_device *cnd;
179	int i;
180
181	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
182		if (cnd->cnd_cn == cn)
183			return (0);
184	for (i = 0; i < CNDEVTAB_SIZE; i++) {
185		cnd = &cn_devtab[i];
186		if (cnd->cnd_cn == NULL)
187			break;
188	}
189	if (cnd->cnd_cn != NULL)
190		return (ENOMEM);
191	cnd->cnd_cn = cn;
192	if (cn->cn_name[0] == '\0') {
193		/* XXX: it is unclear if/where this print might output */
194		printf("WARNING: console at %p has no name\n", cn);
195	}
196	STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next);
197	if (STAILQ_FIRST(&cn_devlist) == cnd)
198		ttyconsdev_select(cnd->cnd_cn->cn_name);
199
200	/* Add device to the active mask. */
201	cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0);
202
203	return (0);
204}
205
206void
207cnremove(struct consdev *cn)
208{
209	struct cn_device *cnd;
210	int i;
211
212	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
213		if (cnd->cnd_cn != cn)
214			continue;
215		if (STAILQ_FIRST(&cn_devlist) == cnd)
216			ttyconsdev_select(NULL);
217		STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
218		cnd->cnd_cn = NULL;
219
220		/* Remove this device from available mask. */
221		for (i = 0; i < CNDEVTAB_SIZE; i++)
222			if (cnd == &cn_devtab[i]) {
223				cons_avail_mask &= ~(1 << i);
224				break;
225			}
226#if 0
227		/*
228		 * XXX
229		 * syscons gets really confused if console resources are
230		 * freed after the system has initialized.
231		 */
232		if (cn->cn_term != NULL)
233			cn->cn_ops->cn_term(cn);
234#endif
235		return;
236	}
237}
238
239void
240cnselect(struct consdev *cn)
241{
242	struct cn_device *cnd;
243
244	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
245		if (cnd->cnd_cn != cn)
246			continue;
247		if (cnd == STAILQ_FIRST(&cn_devlist))
248			return;
249		STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
250		STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next);
251		ttyconsdev_select(cnd->cnd_cn->cn_name);
252		return;
253	}
254}
255
256void
257cnavailable(struct consdev *cn, int available)
258{
259	int i;
260
261	for (i = 0; i < CNDEVTAB_SIZE; i++) {
262		if (cn_devtab[i].cnd_cn == cn)
263			break;
264	}
265	if (available) {
266		if (i < CNDEVTAB_SIZE)
267			cons_avail_mask |= (1 << i);
268		cn->cn_flags &= ~CN_FLAG_NOAVAIL;
269	} else {
270		if (i < CNDEVTAB_SIZE)
271			cons_avail_mask &= ~(1 << i);
272		cn->cn_flags |= CN_FLAG_NOAVAIL;
273	}
274}
275
276int
277cnunavailable(void)
278{
279
280	return (cons_avail_mask == 0);
281}
282
283/*
284 * sysctl_kern_console() provides output parseable in conscontrol(1).
285 */
286static int
287sysctl_kern_console(SYSCTL_HANDLER_ARGS)
288{
289	struct cn_device *cnd;
290	struct consdev *cp, **list;
291	char *p;
292	int delete, error;
293	struct sbuf *sb;
294
295	sb = sbuf_new(NULL, NULL, CNDEVPATHMAX * 2, SBUF_AUTOEXTEND);
296	if (sb == NULL)
297		return (ENOMEM);
298	sbuf_clear(sb);
299	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
300		sbuf_printf(sb, "%s,", cnd->cnd_cn->cn_name);
301	sbuf_printf(sb, "/");
302	SET_FOREACH(list, cons_set) {
303		cp = *list;
304		if (cp->cn_name[0] != '\0')
305			sbuf_printf(sb, "%s,", cp->cn_name);
306	}
307	sbuf_finish(sb);
308	error = sysctl_handle_string(oidp, sbuf_data(sb), sbuf_len(sb), req);
309	if (error == 0 && req->newptr != NULL) {
310		p = sbuf_data(sb);
311		error = ENXIO;
312		delete = 0;
313		if (*p == '-') {
314			delete = 1;
315			p++;
316		}
317		SET_FOREACH(list, cons_set) {
318			cp = *list;
319			if (strcmp(p, cp->cn_name) != 0)
320				continue;
321			if (delete) {
322				cnremove(cp);
323				error = 0;
324			} else {
325				error = cnadd(cp);
326				if (error == 0)
327					cnselect(cp);
328			}
329			break;
330		}
331	}
332	sbuf_delete(sb);
333	return (error);
334}
335
336SYSCTL_PROC(_kern, OID_AUTO, console, CTLTYPE_STRING|CTLFLAG_RW,
337	0, 0, sysctl_kern_console, "A", "Console device control");
338
339/*
340 * User has changed the state of the console muting.
341 * This may require us to open or close the device in question.
342 */
343static int
344sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
345{
346	int error;
347
348	error = sysctl_handle_int(oidp, &cn_mute, 0, req);
349	if (error != 0 || req->newptr == NULL)
350		return (error);
351	return (error);
352}
353
354SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
355	0, sizeof(cn_mute), sysctl_kern_consmute, "I",
356	"State of the console muting");
357
358void
359cngrab()
360{
361	struct cn_device *cnd;
362	struct consdev *cn;
363
364	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
365		cn = cnd->cnd_cn;
366		if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG))
367			cn->cn_ops->cn_grab(cn);
368	}
369}
370
371void
372cnungrab()
373{
374	struct cn_device *cnd;
375	struct consdev *cn;
376
377	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
378		cn = cnd->cnd_cn;
379		if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG))
380			cn->cn_ops->cn_ungrab(cn);
381	}
382}
383
384/*
385 * Low level console routines.
386 */
387int
388cngetc(void)
389{
390	int c;
391
392	if (cn_mute)
393		return (-1);
394	while ((c = cncheckc()) == -1)
395		cpu_spinwait();
396	if (c == '\r')
397		c = '\n';		/* console input is always ICRNL */
398	return (c);
399}
400
401int
402cncheckc(void)
403{
404	struct cn_device *cnd;
405	struct consdev *cn;
406	int c;
407
408	if (cn_mute)
409		return (-1);
410	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
411		cn = cnd->cnd_cn;
412		if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
413			c = cn->cn_ops->cn_getc(cn);
414			if (c != -1)
415				return (c);
416		}
417	}
418	return (-1);
419}
420
421void
422cngets(char *cp, size_t size, int visible)
423{
424	char *lp, *end;
425	int c;
426
427	cngrab();
428
429	lp = cp;
430	end = cp + size - 1;
431	for (;;) {
432		c = cngetc() & 0177;
433		switch (c) {
434		case '\n':
435		case '\r':
436			cnputc(c);
437			*lp = '\0';
438			cnungrab();
439			return;
440		case '\b':
441		case '\177':
442			if (lp > cp) {
443				if (visible)
444					cnputs("\b \b");
445				lp--;
446			}
447			continue;
448		case '\0':
449			continue;
450		default:
451			if (lp < end) {
452				switch (visible) {
453				case GETS_NOECHO:
454					break;
455				case GETS_ECHOPASS:
456					cnputc('*');
457					break;
458				default:
459					cnputc(c);
460					break;
461				}
462				*lp++ = c;
463			}
464		}
465	}
466}
467
468void
469cnputc(int c)
470{
471	struct cn_device *cnd;
472	struct consdev *cn;
473	char *cp;
474
475#ifdef EARLY_PRINTF
476	if (early_putc != NULL) {
477		if (c == '\n')
478			early_putc('\r');
479		early_putc(c);
480		return;
481	}
482#endif
483
484	if (cn_mute || c == '\0')
485		return;
486	STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
487		cn = cnd->cnd_cn;
488		if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
489			if (c == '\n')
490				cn->cn_ops->cn_putc(cn, '\r');
491			cn->cn_ops->cn_putc(cn, c);
492		}
493	}
494	if (console_pausing && c == '\n' && !kdb_active) {
495		for (cp = console_pausestr; *cp != '\0'; cp++)
496			cnputc(*cp);
497		cngrab();
498		if (cngetc() == '.')
499			console_pausing = 0;
500		cnungrab();
501		cnputc('\r');
502		for (cp = console_pausestr; *cp != '\0'; cp++)
503			cnputc(' ');
504		cnputc('\r');
505	}
506}
507
508void
509cnputs(char *p)
510{
511	int c;
512	int unlock_reqd = 0;
513
514	if (use_cnputs_mtx) {
515	  	/*
516		 * NOTE: Debug prints and/or witness printouts in
517		 * console driver clients can cause the "cnputs_mtx"
518		 * mutex to recurse. Simply return if that happens.
519		 */
520		if (mtx_owned(&cnputs_mtx))
521			return;
522		mtx_lock_spin(&cnputs_mtx);
523		unlock_reqd = 1;
524	}
525
526	while ((c = *p++) != '\0')
527		cnputc(c);
528
529	if (unlock_reqd)
530		mtx_unlock_spin(&cnputs_mtx);
531}
532
533static int consmsgbuf_size = 8192;
534SYSCTL_INT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RW, &consmsgbuf_size, 0,
535    "Console tty buffer size");
536
537/*
538 * Redirect console output to a tty.
539 */
540void
541constty_set(struct tty *tp)
542{
543	int size;
544
545	KASSERT(tp != NULL, ("constty_set: NULL tp"));
546	if (consbuf == NULL) {
547		size = consmsgbuf_size;
548		consbuf = malloc(size, M_TTYCONS, M_WAITOK);
549		msgbuf_init(&consmsgbuf, consbuf, size);
550		callout_init(&conscallout, 0);
551	}
552	constty = tp;
553	constty_timeout(NULL);
554}
555
556/*
557 * Disable console redirection to a tty.
558 */
559void
560constty_clear(void)
561{
562	int c;
563
564	constty = NULL;
565	if (consbuf == NULL)
566		return;
567	callout_stop(&conscallout);
568	while ((c = msgbuf_getchar(&consmsgbuf)) != -1)
569		cnputc(c);
570	free(consbuf, M_TTYCONS);
571	consbuf = NULL;
572}
573
574/* Times per second to check for pending console tty messages. */
575static int constty_wakeups_per_second = 5;
576SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW,
577    &constty_wakeups_per_second, 0,
578    "Times per second to check for pending console tty messages");
579
580static void
581constty_timeout(void *arg)
582{
583	int c;
584
585	if (constty != NULL) {
586		tty_lock(constty);
587		while ((c = msgbuf_getchar(&consmsgbuf)) != -1) {
588			if (tty_putchar(constty, c) < 0) {
589				tty_unlock(constty);
590				constty = NULL;
591				break;
592			}
593		}
594
595		if (constty != NULL)
596			tty_unlock(constty);
597	}
598	if (constty != NULL) {
599		callout_reset(&conscallout, hz / constty_wakeups_per_second,
600		    constty_timeout, NULL);
601	} else {
602		/* Deallocate the constty buffer memory. */
603		constty_clear();
604	}
605}
606
607static void
608cn_drvinit(void *unused)
609{
610
611	mtx_init(&cnputs_mtx, "cnputs_mtx", NULL, MTX_SPIN | MTX_NOWITNESS);
612	use_cnputs_mtx = 1;
613}
614
615SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, cn_drvinit, NULL);
616
617/*
618 * Sysbeep(), if we have hardware for it
619 */
620
621#ifdef HAS_TIMER_SPKR
622
623static int beeping;
624
625static void
626sysbeepstop(void *chan)
627{
628
629	timer_spkr_release();
630	beeping = 0;
631}
632
633int
634sysbeep(int pitch, int period)
635{
636
637	if (timer_spkr_acquire()) {
638		if (!beeping) {
639			/* Something else owns it. */
640			return (EBUSY);
641		}
642	}
643	timer_spkr_setfreq(pitch);
644	if (!beeping) {
645		beeping = period;
646		timeout(sysbeepstop, (void *)NULL, period);
647	}
648	return (0);
649}
650
651#else
652
653/*
654 * No hardware, no sound
655 */
656
657int
658sysbeep(int pitch __unused, int period __unused)
659{
660
661	return (ENODEV);
662}
663
664#endif
665
666/*
667 * Temporary support for sc(4) to vt(4) transition.
668 */
669static unsigned vty_prefer;
670static char vty_name[16];
671SYSCTL_STRING(_kern, OID_AUTO, vty, CTLFLAG_RDTUN, vty_name, 0,
672    "Console vty driver");
673
674int
675vty_enabled(unsigned vty)
676{
677	static unsigned vty_selected = 0;
678
679	if (vty_selected == 0) {
680		TUNABLE_STR_FETCH("kern.vty", vty_name, sizeof(vty_name));
681		do {
682#if defined(DEV_SC)
683			if (strcmp(vty_name, "sc") == 0) {
684				vty_selected = VTY_SC;
685				break;
686			}
687#endif
688#if defined(DEV_VT)
689			if (strcmp(vty_name, "vt") == 0) {
690				vty_selected = VTY_VT;
691				break;
692			}
693#endif
694			if (vty_prefer != 0) {
695				vty_selected = vty_prefer;
696				break;
697			}
698#if defined(DEV_SC)
699			vty_selected = VTY_SC;
700#elif defined(DEV_VT)
701			vty_selected = VTY_VT;
702#endif
703		} while (0);
704
705		if (vty_selected == VTY_VT)
706			strcpy(vty_name, "vt");
707		else if (vty_selected == VTY_SC)
708			strcpy(vty_name, "sc");
709	}
710	return ((vty_selected & vty) != 0);
711}
712
713void
714vty_set_preferred(unsigned vty)
715{
716
717	vty_prefer = vty;
718#if !defined(DEV_SC)
719	vty_prefer &= ~VTY_SC;
720#endif
721#if !defined(DEV_VT)
722	vty_prefer &= ~VTY_VT;
723#endif
724}
725
726