kern_cons.c revision 41612 
1/*
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
39 *	$Id: cons.c,v 1.59 1998/08/23 08:26:40 bde Exp $
40 */
41
42#include "opt_devfs.h"
43
44#include <sys/param.h>
45#ifdef DEVFS
46#include <sys/devfsext.h>
47#endif /*DEVFS*/
48#include <sys/systm.h>
49#include <sys/conf.h>
50#include <sys/kernel.h>
51#include <sys/reboot.h>
52#include <sys/sysctl.h>
53#include <sys/proc.h>
54#include <sys/tty.h>
55#include <sys/uio.h>
56
57#include <machine/cpu.h>
58#include <machine/cons.h>
59
60/* XXX this should be config(8)ed. */
61#include "sc.h"
62#include "vt.h"
63#include "sio.h"
64static struct consdev constab[] = {
65#if NSC > 0
66	{ sccnprobe,	sccninit,	sccngetc,	sccncheckc,	sccnputc },
67#endif
68#if NVT > 0
69	{ pccnprobe,	pccninit,	pccngetc,	pccncheckc,	pccnputc },
70#endif
71#if NSIO > 0
72	{ siocnprobe,	siocninit,	siocngetc,	siocncheckc,	siocnputc },
73#endif
74	{ 0 },
75};
76
77static	d_open_t	cnopen;
78static	d_close_t	cnclose;
79static	d_read_t	cnread;
80static	d_write_t	cnwrite;
81static	d_ioctl_t	cnioctl;
82static	d_poll_t	cnpoll;
83
84#define	CDEV_MAJOR	0
85static	struct cdevsw	cn_cdevsw = {
86	cnopen,		cnclose,	cnread,		cnwrite,
87	cnioctl,	nullstop,	nullreset,	nodevtotty,
88	cnpoll,		nommap,		NULL,		"console",
89	NULL,		-1,		nodump,		nopsize,
90	D_TTY,
91};
92
93static dev_t	cn_dev_t; 	/* seems to be never really used */
94SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
95	&cn_dev_t, sizeof cn_dev_t, "T,dev_t", "");
96
97static int cn_mute;
98
99int	cons_unavail = 0;	/* XXX:
100				 * physical console not available for
101				 * input (i.e., it is in graphics mode)
102				 */
103
104static u_char cn_is_open;		/* nonzero if logical console is open */
105static int openmode, openflag;		/* how /dev/console was openned */
106static u_char cn_phys_is_open;		/* nonzero if physical device is open */
107static d_close_t *cn_phys_close;	/* physical device close function */
108static d_open_t *cn_phys_open;		/* physical device open function */
109static struct consdev *cn_tab;		/* physical console device info */
110static struct tty *cn_tp;		/* physical console tty struct */
111#ifdef DEVFS
112static void *cn_devfs_token;		/* represents the devfs entry */
113#endif /* DEVFS */
114
115void
116cninit()
117{
118	struct consdev *best_cp, *cp;
119
120	/*
121	 * Find the first console with the highest priority.
122	 */
123	best_cp = NULL;
124	for (cp = constab; cp->cn_probe; cp++) {
125		(*cp->cn_probe)(cp);
126		if (cp->cn_pri > CN_DEAD &&
127		    (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
128			best_cp = cp;
129	}
130
131	/*
132	 * Check if we should mute the console (for security reasons perhaps)
133	 * It can be changes dynamically using sysctl kern.consmute
134	 * once we are up and going.
135	 *
136	 */
137        cn_mute = ((boothowto & (RB_MUTE
138			|RB_SINGLE
139			|RB_VERBOSE
140			|RB_ASKNAME
141			|RB_CONFIG)) == RB_MUTE);
142
143	/*
144	 * If no console, give up.
145	 */
146	if (best_cp == NULL) {
147		cn_tab = best_cp;
148		return;
149	}
150
151	/*
152	 * Initialize console, then attach to it.  This ordering allows
153	 * debugging using the previous console, if any.
154	 * XXX if there was a previous console, then its driver should
155	 * be informed when we forget about it.
156	 */
157	(*best_cp->cn_init)(best_cp);
158	cn_tab = best_cp;
159}
160
161void
162cninit_finish()
163{
164	struct cdevsw *cdp;
165
166	if ((cn_tab == NULL) || cn_mute)
167		return;
168
169	/*
170	 * Hook the open and close functions.
171	 */
172	cdp = cdevsw[major(cn_tab->cn_dev)];
173	cn_phys_close = cdp->d_close;
174	cdp->d_close = cnclose;
175	cn_phys_open = cdp->d_open;
176	cdp->d_open = cnopen;
177	cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev);
178	cn_dev_t = cn_tp->t_dev;
179}
180
181static void
182cnuninit(void)
183{
184	struct cdevsw *cdp;
185
186	if (cn_tab == NULL)
187		return;
188
189	/*
190	 * Unhook the open and close functions.
191	 */
192	cdp = cdevsw[major(cn_tab->cn_dev)];
193	cdp->d_close = cn_phys_close;
194	cn_phys_close = NULL;
195	cdp->d_open = cn_phys_open;
196	cn_phys_open = NULL;
197	cn_tp = NULL;
198	cn_dev_t = 0;
199}
200
201/*
202 * User has changed the state of the console muting.
203 * This may require us to open or close the device in question.
204 */
205static int
206sysctl_kern_consmute SYSCTL_HANDLER_ARGS
207{
208	int error;
209	int ocn_mute;
210
211	ocn_mute = cn_mute;
212	error = sysctl_handle_int(oidp, &cn_mute, 0, req);
213	if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
214		if(ocn_mute && !cn_mute) {
215			/*
216			 * going from muted to unmuted.. open the physical dev
217			 * if the console has been openned
218			 */
219			cninit_finish();
220			if(cn_is_open)
221				/* XXX curproc is not what we want really */
222				error = cnopen(cn_dev_t, openflag,
223					openmode, curproc);
224			/* if it failed, back it out */
225			if ( error != 0) cnuninit();
226		} else if (!ocn_mute && cn_mute) {
227			/*
228			 * going from unmuted to muted.. close the physical dev
229			 * if it's only open via /dev/console
230			 */
231			if(cn_is_open)
232				error = cnclose(cn_dev_t, openflag,
233					openmode, curproc);
234			if ( error == 0) cnuninit();
235		}
236		if (error != 0) {
237			/*
238	 		 * back out the change if there was an error
239			 */
240			cn_mute = ocn_mute;
241		}
242	}
243	return (error);
244}
245
246SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
247	0, sizeof cn_mute, sysctl_kern_consmute, "I", "");
248
249static int
250cnopen(dev, flag, mode, p)
251	dev_t dev;
252	int flag, mode;
253	struct proc *p;
254{
255	dev_t cndev, physdev;
256	int retval = 0;
257
258	if (cn_tab == NULL)
259		return (0);
260	cndev = cn_tab->cn_dev;
261	physdev = (major(dev) == major(cndev) ? dev : cndev);
262	/*
263	 * If mute is active, then non console opens don't get here
264	 * so we don't need to check for that. They
265	 * bypass this and go straight to the device.
266	 */
267	if(!cn_mute)
268		retval = (*cn_phys_open)(physdev, flag, mode, p);
269	if (retval == 0) {
270		/*
271		 * check if we openned it via /dev/console or
272		 * via the physical entry (e.g. /dev/sio0).
273		 */
274		if (dev == cndev)
275			cn_phys_is_open = 1;
276		else if (physdev == cndev) {
277			openmode = mode;
278			openflag = flag;
279			cn_is_open = 1;
280		}
281	}
282	return (retval);
283}
284
285static int
286cnclose(dev, flag, mode, p)
287	dev_t dev;
288	int flag, mode;
289	struct proc *p;
290{
291	dev_t cndev;
292
293	if (cn_tab == NULL)
294		return (0);
295	cndev = cn_tab->cn_dev;
296	/*
297	 * act appropriatly depending on whether it's /dev/console
298	 * or the pysical device (e.g. /dev/sio) that's being closed.
299	 * in either case, don't actually close the device unless
300	 * both are closed.
301	 */
302	if (dev == cndev) {
303		/* the physical device is about to be closed */
304		cn_phys_is_open = 0;
305		if (cn_is_open) {
306			if (cn_tp) {
307				/* perform a ttyhalfclose() */
308				/* reset session and proc group */
309				cn_tp->t_pgrp = NULL;
310				cn_tp->t_session = NULL;
311			}
312			return (0);
313		}
314	} else if (major(dev) != major(cndev)) {
315		/* the logical console is about to be closed */
316		cn_is_open = 0;
317		if (cn_phys_is_open)
318			return (0);
319		dev = cndev;
320	}
321	if(cn_phys_close)
322		return ((*cn_phys_close)(dev, flag, mode, p));
323	return (0);
324}
325
326static int
327cnread(dev, uio, flag)
328	dev_t dev;
329	struct uio *uio;
330	int flag;
331{
332	if ((cn_tab == NULL) || cn_mute)
333		return (0);
334	dev = cn_tab->cn_dev;
335	return ((*cdevsw[major(dev)]->d_read)(dev, uio, flag));
336}
337
338static int
339cnwrite(dev, uio, flag)
340	dev_t dev;
341	struct uio *uio;
342	int flag;
343{
344	if ((cn_tab == NULL) || cn_mute) {
345		uio->uio_resid = 0; /* dump the data */
346		return (0);
347	}
348	if (constty)
349		dev = constty->t_dev;
350	else
351		dev = cn_tab->cn_dev;
352	return ((*cdevsw[major(dev)]->d_write)(dev, uio, flag));
353}
354
355static int
356cnioctl(dev, cmd, data, flag, p)
357	dev_t dev;
358	u_long cmd;
359	caddr_t data;
360	int flag;
361	struct proc *p;
362{
363	int error;
364
365	if ((cn_tab == NULL) || cn_mute)
366		return (0);
367	/*
368	 * Superuser can always use this to wrest control of console
369	 * output from the "virtual" console.
370	 */
371	if (cmd == TIOCCONS && constty) {
372		error = suser(p->p_ucred, (u_short *) NULL);
373		if (error)
374			return (error);
375		constty = NULL;
376		return (0);
377	}
378	dev = cn_tab->cn_dev;
379	return ((*cdevsw[major(dev)]->d_ioctl)(dev, cmd, data, flag, p));
380}
381
382static int
383cnpoll(dev, events, p)
384	dev_t dev;
385	int events;
386	struct proc *p;
387{
388	if ((cn_tab == NULL) || cn_mute)
389		return (1);
390
391	dev = cn_tab->cn_dev;
392
393	return ((*cdevsw[major(dev)]->d_poll)(dev, events, p));
394}
395
396int
397cngetc()
398{
399	int c;
400	if ((cn_tab == NULL) || cn_mute)
401		return (-1);
402	c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
403	if (c == '\r') c = '\n'; /* console input is always ICRNL */
404	return (c);
405}
406
407int
408cncheckc()
409{
410	if ((cn_tab == NULL) || cn_mute)
411		return (-1);
412	return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
413}
414
415void
416cnputc(c)
417	register int c;
418{
419	if ((cn_tab == NULL) || cn_mute)
420		return;
421	if (c) {
422		if (c == '\n')
423			(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
424		(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
425	}
426}
427
428static cn_devsw_installed = 0;
429
430static void
431cn_drvinit(void *unused)
432{
433	dev_t dev;
434
435	if( ! cn_devsw_installed ) {
436		dev = makedev(CDEV_MAJOR,0);
437		cdevsw_add(&dev,&cn_cdevsw,NULL);
438		cn_devsw_installed = 1;
439#ifdef DEVFS
440		cn_devfs_token = devfs_add_devswf(&cn_cdevsw, 0, DV_CHR,
441						  UID_ROOT, GID_WHEEL, 0600,
442						  "console");
443#endif
444	}
445}
446
447SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)
448
449
450