kern_cons.c revision 46153 
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 1.63 1999/04/27 12:21:03 phk 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
60static	d_open_t	cnopen;
61static	d_close_t	cnclose;
62static	d_read_t	cnread;
63static	d_write_t	cnwrite;
64static	d_ioctl_t	cnioctl;
65static	d_poll_t	cnpoll;
66
67#define	CDEV_MAJOR	0
68static	struct cdevsw	cn_cdevsw = {
69	cnopen,		cnclose,	cnread,		cnwrite,
70	cnioctl,	nullstop,	nullreset,	nodevtotty,
71	cnpoll,		nommap,		NULL,		"console",
72	NULL,		-1,		nodump,		nopsize,
73	D_TTY,
74};
75
76static dev_t	cn_dev_t; 	/* seems to be never really used */
77SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
78	&cn_dev_t, sizeof cn_dev_t, "T,dev_t", "");
79
80static int cn_mute;
81
82int	cons_unavail = 0;	/* XXX:
83				 * physical console not available for
84				 * input (i.e., it is in graphics mode)
85				 */
86
87static u_char cn_is_open;		/* nonzero if logical console is open */
88static int openmode, openflag;		/* how /dev/console was openned */
89static u_char cn_phys_is_open;		/* nonzero if physical device is open */
90static d_close_t *cn_phys_close;	/* physical device close function */
91static d_open_t *cn_phys_open;		/* physical device open function */
92static struct consdev *cn_tab;		/* physical console device info */
93static struct tty *cn_tp;		/* physical console tty struct */
94#ifdef DEVFS
95static void *cn_devfs_token;		/* represents the devfs entry */
96#endif /* DEVFS */
97
98CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL);
99
100void
101cninit()
102{
103	struct consdev *best_cp, *cp;
104	struct consdev **list;
105
106	/*
107	 * Find the first console with the highest priority.
108	 */
109	best_cp = NULL;
110	list = (struct consdev **)cons_set.ls_items;
111	while ((cp = *list++) != NULL) {
112		if (cp->cn_probe == NULL)
113			continue;
114		(*cp->cn_probe)(cp);
115		if (cp->cn_pri > CN_DEAD &&
116		    (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
117			best_cp = cp;
118	}
119
120	/*
121	 * Check if we should mute the console (for security reasons perhaps)
122	 * It can be changes dynamically using sysctl kern.consmute
123	 * once we are up and going.
124	 *
125	 */
126        cn_mute = ((boothowto & (RB_MUTE
127			|RB_SINGLE
128			|RB_VERBOSE
129			|RB_ASKNAME
130			|RB_CONFIG)) == RB_MUTE);
131
132	/*
133	 * If no console, give up.
134	 */
135	if (best_cp == NULL) {
136		cn_tab = best_cp;
137		return;
138	}
139
140	/*
141	 * Initialize console, then attach to it.  This ordering allows
142	 * debugging using the previous console, if any.
143	 * XXX if there was a previous console, then its driver should
144	 * be informed when we forget about it.
145	 */
146	(*best_cp->cn_init)(best_cp);
147	cn_tab = best_cp;
148}
149
150void
151cninit_finish()
152{
153	struct cdevsw *cdp;
154
155	if ((cn_tab == NULL) || cn_mute)
156		return;
157
158	/*
159	 * Hook the open and close functions.
160	 */
161	cdp = cdevsw[major(cn_tab->cn_dev)];
162	cn_phys_close = cdp->d_close;
163	cdp->d_close = cnclose;
164	cn_phys_open = cdp->d_open;
165	cdp->d_open = cnopen;
166	cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev);
167	cn_dev_t = cn_tp->t_dev;
168}
169
170static void
171cnuninit(void)
172{
173	struct cdevsw *cdp;
174
175	if (cn_tab == NULL)
176		return;
177
178	/*
179	 * Unhook the open and close functions.
180	 */
181	cdp = cdevsw[major(cn_tab->cn_dev)];
182	cdp->d_close = cn_phys_close;
183	cn_phys_close = NULL;
184	cdp->d_open = cn_phys_open;
185	cn_phys_open = NULL;
186	cn_tp = NULL;
187	cn_dev_t = 0;
188}
189
190/*
191 * User has changed the state of the console muting.
192 * This may require us to open or close the device in question.
193 */
194static int
195sysctl_kern_consmute SYSCTL_HANDLER_ARGS
196{
197	int error;
198	int ocn_mute;
199
200	ocn_mute = cn_mute;
201	error = sysctl_handle_int(oidp, &cn_mute, 0, req);
202	if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
203		if(ocn_mute && !cn_mute) {
204			/*
205			 * going from muted to unmuted.. open the physical dev
206			 * if the console has been openned
207			 */
208			cninit_finish();
209			if(cn_is_open)
210				/* XXX curproc is not what we want really */
211				error = cnopen(cn_dev_t, openflag,
212					openmode, curproc);
213			/* if it failed, back it out */
214			if ( error != 0) cnuninit();
215		} else if (!ocn_mute && cn_mute) {
216			/*
217			 * going from unmuted to muted.. close the physical dev
218			 * if it's only open via /dev/console
219			 */
220			if(cn_is_open)
221				error = cnclose(cn_dev_t, openflag,
222					openmode, curproc);
223			if ( error == 0) cnuninit();
224		}
225		if (error != 0) {
226			/*
227	 		 * back out the change if there was an error
228			 */
229			cn_mute = ocn_mute;
230		}
231	}
232	return (error);
233}
234
235SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
236	0, sizeof cn_mute, sysctl_kern_consmute, "I", "");
237
238static int
239cnopen(dev, flag, mode, p)
240	dev_t dev;
241	int flag, mode;
242	struct proc *p;
243{
244	dev_t cndev, physdev;
245	int retval = 0;
246
247	if (cn_tab == NULL)
248		return (0);
249	cndev = cn_tab->cn_dev;
250	physdev = (major(dev) == major(cndev) ? dev : cndev);
251	/*
252	 * If mute is active, then non console opens don't get here
253	 * so we don't need to check for that. They
254	 * bypass this and go straight to the device.
255	 */
256	if(!cn_mute)
257		retval = (*cn_phys_open)(physdev, flag, mode, p);
258	if (retval == 0) {
259		/*
260		 * check if we openned it via /dev/console or
261		 * via the physical entry (e.g. /dev/sio0).
262		 */
263		if (dev == cndev)
264			cn_phys_is_open = 1;
265		else if (physdev == cndev) {
266			openmode = mode;
267			openflag = flag;
268			cn_is_open = 1;
269		}
270	}
271	return (retval);
272}
273
274static int
275cnclose(dev, flag, mode, p)
276	dev_t dev;
277	int flag, mode;
278	struct proc *p;
279{
280	dev_t cndev;
281
282	if (cn_tab == NULL)
283		return (0);
284	cndev = cn_tab->cn_dev;
285	/*
286	 * act appropriatly depending on whether it's /dev/console
287	 * or the pysical device (e.g. /dev/sio) that's being closed.
288	 * in either case, don't actually close the device unless
289	 * both are closed.
290	 */
291	if (dev == cndev) {
292		/* the physical device is about to be closed */
293		cn_phys_is_open = 0;
294		if (cn_is_open) {
295			if (cn_tp) {
296				/* perform a ttyhalfclose() */
297				/* reset session and proc group */
298				cn_tp->t_pgrp = NULL;
299				cn_tp->t_session = NULL;
300			}
301			return (0);
302		}
303	} else if (major(dev) != major(cndev)) {
304		/* the logical console is about to be closed */
305		cn_is_open = 0;
306		if (cn_phys_is_open)
307			return (0);
308		dev = cndev;
309	}
310	if(cn_phys_close)
311		return ((*cn_phys_close)(dev, flag, mode, p));
312	return (0);
313}
314
315static int
316cnread(dev, uio, flag)
317	dev_t dev;
318	struct uio *uio;
319	int flag;
320{
321	if ((cn_tab == NULL) || cn_mute)
322		return (0);
323	dev = cn_tab->cn_dev;
324	return ((*cdevsw[major(dev)]->d_read)(dev, uio, flag));
325}
326
327static int
328cnwrite(dev, uio, flag)
329	dev_t dev;
330	struct uio *uio;
331	int flag;
332{
333	if ((cn_tab == NULL) || cn_mute) {
334		uio->uio_resid = 0; /* dump the data */
335		return (0);
336	}
337	if (constty)
338		dev = constty->t_dev;
339	else
340		dev = cn_tab->cn_dev;
341	return ((*cdevsw[major(dev)]->d_write)(dev, uio, flag));
342}
343
344static int
345cnioctl(dev, cmd, data, flag, p)
346	dev_t dev;
347	u_long cmd;
348	caddr_t data;
349	int flag;
350	struct proc *p;
351{
352	int error;
353
354	if ((cn_tab == NULL) || cn_mute)
355		return (0);
356	/*
357	 * Superuser can always use this to wrest control of console
358	 * output from the "virtual" console.
359	 */
360	if (cmd == TIOCCONS && constty) {
361		error = suser(p);
362		if (error)
363			return (error);
364		constty = NULL;
365		return (0);
366	}
367	dev = cn_tab->cn_dev;
368	return ((*cdevsw[major(dev)]->d_ioctl)(dev, cmd, data, flag, p));
369}
370
371static int
372cnpoll(dev, events, p)
373	dev_t dev;
374	int events;
375	struct proc *p;
376{
377	if ((cn_tab == NULL) || cn_mute)
378		return (1);
379
380	dev = cn_tab->cn_dev;
381
382	return ((*cdevsw[major(dev)]->d_poll)(dev, events, p));
383}
384
385int
386cngetc()
387{
388	int c;
389	if ((cn_tab == NULL) || cn_mute)
390		return (-1);
391	c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
392	if (c == '\r') c = '\n'; /* console input is always ICRNL */
393	return (c);
394}
395
396int
397cncheckc()
398{
399	if ((cn_tab == NULL) || cn_mute)
400		return (-1);
401	return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
402}
403
404void
405cnputc(c)
406	register int c;
407{
408	if ((cn_tab == NULL) || cn_mute)
409		return;
410	if (c) {
411		if (c == '\n')
412			(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
413		(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
414	}
415}
416
417static int cn_devsw_installed;
418
419static void
420cn_drvinit(void *unused)
421{
422	dev_t dev;
423
424	if( ! cn_devsw_installed ) {
425		dev = makedev(CDEV_MAJOR,0);
426		cdevsw_add(&dev,&cn_cdevsw,NULL);
427		cn_devsw_installed = 1;
428#ifdef DEVFS
429		cn_devfs_token = devfs_add_devswf(&cn_cdevsw, 0, DV_CHR,
430						  UID_ROOT, GID_WHEEL, 0600,
431						  "console");
432#endif
433	}
434}
435
436SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)
437
438
439