HAMMER 40B/Many: Inode/link-count sequencer cleanup pass.
[dragonfly.git] / sys / kern / tty_cons.c
blobe4bff4e4019d64f5bd50f24c58af1feb26b34f21
1 /*
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * All rights reserved.
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.
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.
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.
38 * from: @(#)cons.c 7.2 (Berkeley) 5/9/91
39 * $FreeBSD: src/sys/kern/tty_cons.c,v 1.81.2.4 2001/12/17 18:44:41 guido Exp $
40 * $DragonFly: src/sys/kern/tty_cons.c,v 1.21 2007/05/07 05:21:41 dillon Exp $
43 #include "opt_ddb.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/conf.h>
48 #include <sys/cons.h>
49 #include <sys/kernel.h>
50 #include <sys/proc.h>
51 #include <sys/reboot.h>
52 #include <sys/sysctl.h>
53 #include <sys/tty.h>
54 #include <sys/uio.h>
55 #include <sys/msgport.h>
56 #include <sys/msgport2.h>
57 #include <sys/device.h>
59 #include <ddb/ddb.h>
61 #include <machine/cpu.h>
63 static d_open_t cnopen;
64 static d_close_t cnclose;
65 static d_read_t cnread;
66 static d_write_t cnwrite;
67 static d_ioctl_t cnioctl;
68 static d_poll_t cnpoll;
69 static d_kqfilter_t cnkqfilter;
71 static int cnintercept(struct dev_generic_args *ap);
73 #define CDEV_MAJOR 0
74 static struct dev_ops cn_ops = {
75 { "console", CDEV_MAJOR, D_TTY | D_KQFILTER },
76 .d_open = cnopen,
77 .d_close = cnclose,
78 .d_read = cnread,
79 .d_write = cnwrite,
80 .d_ioctl = cnioctl,
81 .d_poll = cnpoll,
82 .d_kqfilter = cnkqfilter,
85 static struct dev_ops cn_iops = {
86 { "intercept", CDEV_MAJOR, D_TTY | D_KQFILTER },
87 .d_default = cnintercept
90 static struct dev_ops *cn_fwd_ops;
91 static cdev_t cn_dev;
92 static udev_t cn_udev;
93 SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
94 &cn_udev, sizeof cn_udev, "T,udev_t", "");
96 static int cn_mute;
98 int cons_unavail = 0; /* XXX:
99 * physical console not available for
100 * input (i.e., it is in graphics mode)
103 static u_char cn_is_open; /* nonzero if logical console is open */
104 static int openmode, openflag; /* how /dev/console was openned */
105 static cdev_t cn_devfsdev; /* represents the device private info */
106 static u_char cn_phys_is_open; /* nonzero if physical device is open */
107 static u_char console_pausing; /* pause after each line during probe */
108 static char *console_pausestr=
109 "<pause; press any key to proceed to next line or '.' to end pause mode>";
111 struct consdev *cn_tab; /* physical console device info */
112 struct consdev *gdb_tab; /* physical gdb debugger device info */
114 CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
115 SET_DECLARE(cons_set, struct consdev);
117 void
118 cninit(void)
120 struct consdev *best_cp, *cp, **list;
123 * Find the first console with the highest priority.
125 best_cp = NULL;
126 SET_FOREACH(list, cons_set) {
127 cp = *list;
128 if (cp->cn_probe == NULL)
129 continue;
130 (*cp->cn_probe)(cp);
131 if (cp->cn_pri > CN_DEAD && cp->cn_probegood &&
132 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
133 best_cp = cp;
137 * Check if we should mute the console (for security reasons perhaps)
138 * It can be changes dynamically using sysctl kern.consmute
139 * once we are up and going.
142 cn_mute = ((boothowto & (RB_MUTE
143 |RB_SINGLE
144 |RB_VERBOSE
145 |RB_ASKNAME
146 |RB_CONFIG)) == RB_MUTE);
149 * If no console, give up.
151 if (best_cp == NULL) {
152 if (cn_tab != NULL && cn_tab->cn_term != NULL)
153 (*cn_tab->cn_term)(cn_tab);
154 cn_tab = best_cp;
155 return;
159 * Initialize console, then attach to it. This ordering allows
160 * debugging using the previous console, if any.
162 (*best_cp->cn_init)(best_cp);
163 if (cn_tab != NULL && cn_tab != best_cp) {
164 /* Turn off the previous console. */
165 if (cn_tab->cn_term != NULL)
166 (*cn_tab->cn_term)(cn_tab);
168 if (boothowto & RB_PAUSE)
169 console_pausing = 1;
170 cn_tab = best_cp;
174 * Hook the open and close functions on the selected device.
176 void
177 cninit_finish(void)
179 if ((cn_tab == NULL) || cn_mute)
180 return;
182 if (cn_tab->cn_dev == NULL) {
183 cn_tab->cn_init_fini(cn_tab);
185 if (cn_tab->cn_dev == NULL) {
186 kprintf("Unable to hook console open and close! cn_tab %p\n",
187 cn_tab);
188 return;
192 * Hook the open and close functions. XXX bad hack.
194 if (dev_is_good(cn_tab->cn_dev)) {
195 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops);
197 cn_dev = cn_tab->cn_dev;
198 cn_udev = dev2udev(cn_dev);
199 console_pausing = 0;
202 static void
203 cnuninit(void)
205 if (cn_tab == NULL)
206 return;
209 * Unhook the open and close functions. XXX bad hack
211 if (cn_fwd_ops)
212 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops);
213 cn_fwd_ops = NULL;
214 cn_dev = NULL;
215 cn_udev = NOUDEV;
219 * User has changed the state of the console muting.
220 * This may require us to open or close the device in question.
222 static int
223 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
225 int error;
226 int ocn_mute;
228 ocn_mute = cn_mute;
229 error = sysctl_handle_int(oidp, &cn_mute, 0, req);
230 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
231 if(ocn_mute && !cn_mute) {
233 * going from muted to unmuted.. open the physical dev
234 * if the console has been openned
236 cninit_finish();
237 if (cn_is_open) {
238 /* XXX curproc is not what we want really */
239 error = dev_dopen(cn_dev, openflag,
240 openmode, curproc->p_ucred);
242 /* if it failed, back it out */
243 if ( error != 0) cnuninit();
244 } else if (!ocn_mute && cn_mute) {
246 * going from unmuted to muted.. close the physical dev
247 * if it's only open via /dev/console
249 if (cn_is_open) {
250 error = dev_dclose(cn_dev, openflag,
251 openmode);
253 if (error == 0)
254 cnuninit();
256 if (error != 0) {
258 * back out the change if there was an error
260 cn_mute = ocn_mute;
263 return (error);
266 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
267 0, sizeof cn_mute, sysctl_kern_consmute, "I", "");
270 * We intercept the OPEN and CLOSE calls on the original device, and
271 * forward the rest through.
273 static int
274 cnintercept(struct dev_generic_args *ap)
276 int error;
278 if (ap->a_desc == &dev_open_desc) {
279 error = cnopen((struct dev_open_args *)ap);
280 } else if (ap->a_desc == &dev_close_desc) {
281 error = cnclose((struct dev_close_args *)ap);
282 } else if (cn_fwd_ops) {
283 error = dev_doperate_ops(cn_fwd_ops, ap);
284 } else {
285 error = ENXIO;
287 return (error);
291 * cnopen() is called as an intercept function (dev will be that of the
292 * actual physical device representing our console), and also called from
293 * the muting code and from the /dev/console switch (dev will have the
294 * console's cdevsw).
296 static int
297 cnopen(struct dev_open_args *ap)
299 cdev_t dev = ap->a_head.a_dev;
300 int flag = ap->a_oflags;
301 int mode = ap->a_devtype;
302 cdev_t cndev, physdev;
303 int retval = 0;
305 if (cn_tab == NULL || cn_fwd_ops == NULL)
306 return (0);
307 cndev = cn_tab->cn_dev;
308 physdev = (major(dev) == major(cndev) ? dev : cndev);
311 * If mute is active, then non console opens don't get here
312 * so we don't need to check for that. They bypass this and go
313 * straight to the device.
315 * It is important to note that due to our intercept and the fact
316 * that we might be called via the original (intercepted) device,
317 * the original device's ops may point to us, so to avoid an
318 * infinite recursion we have to forward through cn_fwd_ops.
319 * This is a severe hack that really needs to be fixed XXX.
321 * XXX at the moment we assume that the port forwarding function
322 * is synchronous for open.
324 if (!cn_mute) {
325 ap->a_head.a_dev = physdev;
326 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head);
328 if (retval == 0) {
330 * check if we openned it via /dev/console or
331 * via the physical entry (e.g. /dev/sio0).
333 if (dev == cndev)
334 cn_phys_is_open = 1;
335 else if (physdev == cndev) {
336 openmode = mode;
337 openflag = flag;
338 cn_is_open = 1;
340 dev->si_tty = physdev->si_tty;
342 return (retval);
346 * cnclose() is called as a port intercept function (dev will be that of the
347 * actual physical device representing our console), and also called from
348 * the muting code and from the /dev/console switch (dev will have the
349 * console's cdevsw).
351 static int
352 cnclose(struct dev_close_args *ap)
354 cdev_t dev = ap->a_head.a_dev;
355 cdev_t cndev;
356 struct tty *cn_tp;
358 if (cn_tab == NULL || cn_fwd_ops == NULL)
359 return (0);
360 cndev = cn_tab->cn_dev;
361 cn_tp = cndev->si_tty;
363 * act appropriatly depending on whether it's /dev/console
364 * or the pysical device (e.g. /dev/sio) that's being closed.
365 * in either case, don't actually close the device unless
366 * both are closed.
368 if (dev == cndev) {
369 /* the physical device is about to be closed */
370 cn_phys_is_open = 0;
371 if (cn_is_open) {
372 if (cn_tp) {
373 /* perform a ttyhalfclose() */
374 /* reset session and proc group */
375 ttyclearsession(cn_tp);
377 return (0);
379 } else if (major(dev) != major(cndev)) {
380 /* the logical console is about to be closed */
381 cn_is_open = 0;
382 if (cn_phys_is_open)
383 return (0);
384 dev = cndev;
386 if (cn_fwd_ops) {
387 ap->a_head.a_dev = dev;
388 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head));
390 return (0);
394 * The following functions are dispatched solely from the /dev/console
395 * device. Their job is primarily to forward the request through.
396 * If the console is not attached to anything then write()'s are sunk
397 * to null and reads return 0 (mostly).
399 static int
400 cnread(struct dev_read_args *ap)
402 if (cn_tab == NULL || cn_fwd_ops == NULL)
403 return (0);
404 ap->a_head.a_dev = cn_tab->cn_dev;
405 return (dev_doperate(&ap->a_head));
408 static int
409 cnwrite(struct dev_write_args *ap)
411 struct uio *uio = ap->a_uio;
412 cdev_t dev;
414 if (cn_tab == NULL || cn_fwd_ops == NULL) {
415 uio->uio_resid = 0; /* dump the data */
416 return (0);
418 if (constty)
419 dev = constty->t_dev;
420 else
421 dev = cn_tab->cn_dev;
422 log_console(uio);
423 ap->a_head.a_dev = dev;
424 return (dev_doperate(&ap->a_head));
427 static int
428 cnioctl(struct dev_ioctl_args *ap)
430 int error;
432 if (cn_tab == NULL || cn_fwd_ops == NULL)
433 return (0);
434 KKASSERT(curproc != NULL);
436 * Superuser can always use this to wrest control of console
437 * output from the "virtual" console.
439 if (ap->a_cmd == TIOCCONS && constty) {
440 if (ap->a_cred) {
441 error = suser_cred(ap->a_cred, 0);
442 if (error)
443 return (error);
445 constty = NULL;
446 return (0);
448 ap->a_head.a_dev = cn_tab->cn_dev;
449 return (dev_doperate(&ap->a_head));
452 static int
453 cnpoll(struct dev_poll_args *ap)
455 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL)
456 return (1);
457 ap->a_head.a_dev = cn_tab->cn_dev;
458 return (dev_doperate(&ap->a_head));
461 static int
462 cnkqfilter(struct dev_kqfilter_args *ap)
464 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL)
465 return (1);
466 ap->a_head.a_dev = cn_tab->cn_dev;
467 return (dev_doperate(&ap->a_head));
471 * These synchronous functions are primarily used the kernel needs to
472 * access the keyboard (e.g. when running the debugger), or output data
473 * directly to the console.
476 cngetc(void)
478 int c;
479 if ((cn_tab == NULL) || cn_mute)
480 return (-1);
481 c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
482 if (c == '\r') c = '\n'; /* console input is always ICRNL */
483 return (c);
487 cncheckc(void)
489 if ((cn_tab == NULL) || cn_mute)
490 return (-1);
491 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
494 void
495 cnputc(int c)
497 char *cp;
499 if ((cn_tab == NULL) || cn_mute)
500 return;
501 if (c) {
502 if (c == '\n')
503 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
504 (*cn_tab->cn_putc)(cn_tab->cn_dev, c);
505 #ifdef DDB
506 if (console_pausing && !db_active && (c == '\n')) {
507 #else
508 if (console_pausing && (c == '\n')) {
509 #endif
510 for(cp=console_pausestr; *cp != '\0'; cp++)
511 (*cn_tab->cn_putc)(cn_tab->cn_dev, *cp);
512 if (cngetc() == '.')
513 console_pausing = 0;
514 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
515 for(cp=console_pausestr; *cp != '\0'; cp++)
516 (*cn_tab->cn_putc)(cn_tab->cn_dev, ' ');
517 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
522 void
523 cndbctl(int on)
525 static int refcount;
527 if (cn_tab == NULL)
528 return;
529 if (!on)
530 refcount--;
531 if (refcount == 0 && cn_tab->cn_dbctl != NULL)
532 (*cn_tab->cn_dbctl)(cn_tab->cn_dev, on);
533 if (on)
534 refcount++;
537 static void
538 cn_drvinit(void *unused)
540 dev_ops_add(&cn_ops, 0, 0);
541 cn_devfsdev = make_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL,
542 0600, "console");
545 SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)