summaryrefslogtreecommitdiffstats
path: root/sys/kern/tty_cons.c
blob: 9aa2c23386d6f07b3bdafb7f49ebb87d65ae7931 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/tty.h>
#include <sys/uio.h>

#include <machine/cpu.h>

static	d_open_t	cnopen;
static	d_close_t	cnclose;
static	d_read_t	cnread;
static	d_write_t	cnwrite;
static	d_ioctl_t	cnioctl;
static	d_poll_t	cnpoll;
static	d_kqfilter_t	cnkqfilter;

#define	CDEV_MAJOR	0
static struct cdevsw cn_cdevsw = {
	/* open */	cnopen,
	/* close */	cnclose,
	/* read */	cnread,
	/* write */	cnwrite,
	/* ioctl */	cnioctl,
	/* poll */	cnpoll,
	/* mmap */	nommap,
	/* strategy */	nostrategy,
	/* name */	"console",
	/* maj */	CDEV_MAJOR,
	/* dump */	nodump,
	/* psize */	nopsize,
	/* flags */	D_TTY | D_KQFILTER,
	/* bmaj */	-1,
	/* kqfilter */	cnkqfilter,
};

static dev_t	cn_dev_t; 	/* seems to be never really used */
static udev_t	cn_udev_t;
SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
	&cn_udev_t, sizeof cn_udev_t, "T,dev_t", "");

static int cn_mute;

int	cons_unavail = 0;	/* XXX:
				 * physical console not available for
				 * input (i.e., it is in graphics mode)
				 */

static u_char cn_is_open;		/* nonzero if logical console is open */
static int openmode, openflag;		/* how /dev/console was openned */
static dev_t cn_devfsdev;		/* represents the device private info */
static u_char cn_phys_is_open;		/* nonzero if physical device is open */
static d_close_t *cn_phys_close;	/* physical device close function */
static d_open_t *cn_phys_open;		/* physical device open function */
       struct consdev *cn_tab;		/* physical console device info */

CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL);

void
cninit()
{
	struct consdev *best_cp, *cp, **list;

	/*
	 * Find the first console with the highest priority.
	 */
	best_cp = NULL;
	list = (struct consdev **)cons_set.ls_items;
	while ((cp = *list++) != NULL) {
		if (cp->cn_probe == NULL)
			continue;
		(*cp->cn_probe)(cp);
		if (cp->cn_pri > CN_DEAD &&
		    (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
			best_cp = cp;
	}

	/*
	 * Check if we should mute the console (for security reasons perhaps)
	 * It can be changes dynamically using sysctl kern.consmute
	 * once we are up and going.
	 * 
	 */
        cn_mute = ((boothowto & (RB_MUTE
			|RB_SINGLE
			|RB_VERBOSE
			|RB_ASKNAME
			|RB_CONFIG)) == RB_MUTE);
	
	/*
	 * If no console, give up.
	 */
	if (best_cp == NULL) {
		if (cn_tab != NULL && cn_tab->cn_term != NULL)
			(*cn_tab->cn_term)(cn_tab);
		cn_tab = best_cp;
		return;
	}

	/*
	 * Initialize console, then attach to it.  This ordering allows
	 * debugging using the previous console, if any.
	 */
	(*best_cp->cn_init)(best_cp);
	if (cn_tab != NULL && cn_tab != best_cp) {
		/* Turn off the previous console.  */
		if (cn_tab->cn_term != NULL)
			(*cn_tab->cn_term)(cn_tab);
	}
	cn_tab = best_cp;
}

void
cninit_finish()
{
	struct cdevsw *cdp;

	if ((cn_tab == NULL) || cn_mute)
		return;

	/*
	 * Hook the open and close functions.
	 */
	cdp = devsw(cn_tab->cn_dev);
	if (cdp != NULL) {
		cn_phys_close = cdp->d_close;
		cdp->d_close = cnclose;
		cn_phys_open = cdp->d_open;
		cdp->d_open = cnopen;
	}
	cn_dev_t = cn_tab->cn_dev;
	cn_udev_t = dev2udev(cn_dev_t);
}

static void
cnuninit(void)
{
	struct cdevsw *cdp;

	if (cn_tab == NULL)
		return;

	/*
	 * Unhook the open and close functions.
	 */
	cdp = devsw(cn_tab->cn_dev);
	if (cdp != NULL) {
		cdp->d_close = cn_phys_close;
		cdp->d_open = cn_phys_open;
	}
	cn_phys_close = NULL;
	cn_phys_open = NULL;
	cn_dev_t = NODEV;
	cn_udev_t = NOUDEV;
}

/*
 * User has changed the state of the console muting.
 * This may require us to open or close the device in question.
 */
static int
sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
{
	int error;
	int ocn_mute;

	ocn_mute = cn_mute;
	error = sysctl_handle_int(oidp, &cn_mute, 0, req);
	if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
		if(ocn_mute && !cn_mute) {
			/*
			 * going from muted to unmuted.. open the physical dev 
			 * if the console has been openned
			 */
			cninit_finish();
			if(cn_is_open)
				/* XXX curproc is not what we want really */
				error = cnopen(cn_dev_t, openflag,
					openmode, curproc);
			/* if it failed, back it out */
			if ( error != 0) cnuninit();
		} else if (!ocn_mute && cn_mute) {
			/*
			 * going from unmuted to muted.. close the physical dev 
			 * if it's only open via /dev/console
			 */
			if(cn_is_open)
				error = cnclose(cn_dev_t, openflag,
					openmode, curproc);
			if ( error == 0) cnuninit();
		}
		if (error != 0) {
			/* 
	 		 * back out the change if there was an error
			 */
			cn_mute = ocn_mute;
		}
	}
	return (error);
}

SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
	0, sizeof cn_mute, sysctl_kern_consmute, "I", "");

static int
cnopen(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	dev_t cndev, physdev;
	int retval = 0;

	if (cn_tab == NULL || cn_phys_open == NULL)
		return (0);
	cndev = cn_tab->cn_dev;
	physdev = (major(dev) == major(cndev) ? dev : cndev);
	/*
	 * If mute is active, then non console opens don't get here
	 * so we don't need to check for that. They 
	 * bypass this and go straight to the device.
	 */
	if(!cn_mute)
		retval = (*cn_phys_open)(physdev, flag, mode, p);
	if (retval == 0) {
		/* 
		 * check if we openned it via /dev/console or 
		 * via the physical entry (e.g. /dev/sio0).
		 */
		if (dev == cndev)
			cn_phys_is_open = 1;
		else if (physdev == cndev) {
			openmode = mode;
			openflag = flag;
			cn_is_open = 1;
		}
		dev->si_tty = physdev->si_tty;
	}
	return (retval);
}

static int
cnclose(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	dev_t cndev;
	struct tty *cn_tp;

	if (cn_tab == NULL || cn_phys_open == NULL)
		return (0);
	cndev = cn_tab->cn_dev;
	cn_tp = cndev->si_tty;
	/*
	 * act appropriatly depending on whether it's /dev/console
	 * or the pysical device (e.g. /dev/sio) that's being closed.
	 * in either case, don't actually close the device unless
	 * both are closed.
	 */
	if (dev == cndev) {
		/* the physical device is about to be closed */
		cn_phys_is_open = 0;
		if (cn_is_open) {
			if (cn_tp) {
				/* perform a ttyhalfclose() */
				/* reset session and proc group */
				cn_tp->t_pgrp = NULL;
				cn_tp->t_session = NULL;
			}
			return (0);
		}
	} else if (major(dev) != major(cndev)) {
		/* the logical console is about to be closed */
		cn_is_open = 0;
		if (cn_phys_is_open)
			return (0);
		dev = cndev;
	}
	if(cn_phys_close)
		return ((*cn_phys_close)(dev, flag, mode, p));
	return (0);
}

static int
cnread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{

	if (cn_tab == NULL || cn_phys_open == NULL)
		return (0);
	dev = cn_tab->cn_dev;
	return ((*devsw(dev)->d_read)(dev, uio, flag));
}

static int
cnwrite(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{

	if (cn_tab == NULL || cn_phys_open == NULL) {
		uio->uio_resid = 0; /* dump the data */
		return (0);
	}
	if (constty)
		dev = constty->t_dev;
	else
		dev = cn_tab->cn_dev;
	log_console(uio);
	return ((*devsw(dev)->d_write)(dev, uio, flag));
}

static int
cnioctl(dev, cmd, data, flag, p)
	dev_t dev;
	u_long cmd;
	caddr_t data;
	int flag;
	struct proc *p;
{
	int error;

	if (cn_tab == NULL || cn_phys_open == NULL)
		return (0);
	/*
	 * Superuser can always use this to wrest control of console
	 * output from the "virtual" console.
	 */
	if (cmd == TIOCCONS && constty) {
		error = suser(p);
		if (error)
			return (error);
		constty = NULL;
		return (0);
	}
	dev = cn_tab->cn_dev;
	return ((*devsw(dev)->d_ioctl)(dev, cmd, data, flag, p));
}

static int
cnpoll(dev, events, p)
	dev_t dev;
	int events;
	struct proc *p;
{
	if ((cn_tab == NULL) || cn_mute)
		return (1);

	dev = cn_tab->cn_dev;

	return ((*devsw(dev)->d_poll)(dev, events, p));
}

static int
cnkqfilter(dev, kn)
	dev_t dev;
	struct knote *kn;
{
	if ((cn_tab == NULL) || cn_mute)
		return (1);

	dev = cn_tab->cn_dev;
	if (devsw(dev)->d_flags & D_KQFILTER)
		return ((*devsw(dev)->d_kqfilter)(dev, kn));
	return (1);
}

int
cngetc()
{
	int c;
	if ((cn_tab == NULL) || cn_mute)
		return (-1);
	c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
	if (c == '\r') c = '\n'; /* console input is always ICRNL */
	return (c);
}

int
cncheckc()
{
	if ((cn_tab == NULL) || cn_mute)
		return (-1);
	return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
}

void
cnputc(c)
	register int c;
{
	if ((cn_tab == NULL) || cn_mute)
		return;
	if (c) {
		if (c == '\n')
			(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
		(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
	}
}

void
cndbctl(on)
	int on;
{
	static int refcount;

	if (cn_tab == NULL)
		return;
	if (!on)
		refcount--;
	if (refcount == 0 && cn_tab->cn_dbctl != NULL)
		(*cn_tab->cn_dbctl)(cn_tab->cn_dev, on);
	if (on)
		refcount++;
}

static void
cn_drvinit(void *unused)
{

	cn_devfsdev = make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
	    "console");
}

SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)
OpenPOWER on IntegriCloud