FreeBSD-5.3/sys/kern/tty_cons.c
/*
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/tty_cons.c,v 1.127 2004/08/15 06:24:41 jmg Exp $");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/msgbuf.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/tty.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <ddb/ddb.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;
/*
* XXX: We really want major #0, but zero here means
* XXX: allocate a major number automatically.
* XXX: kern_conf.c knows what to do when it sees 256.
*/
static struct cdevsw cn_cdevsw = {
.d_version = D_VERSION,
.d_open = cnopen,
.d_close = cnclose,
.d_read = cnread,
.d_write = cnwrite,
.d_ioctl = cnioctl,
.d_poll = cnpoll,
.d_name = "console",
.d_maj = 256,
.d_flags = D_TTY | D_NEEDGIANT,
.d_kqfilter = cnkqfilter,
};
struct cn_device {
STAILQ_ENTRY(cn_device) cnd_next;
struct vnode *cnd_vp;
struct consdev *cnd_cn;
};
#define CNDEVPATHMAX 32
#define CNDEVTAB_SIZE 4
static struct cn_device cn_devtab[CNDEVTAB_SIZE];
static STAILQ_HEAD(, cn_device) cn_devlist =
STAILQ_HEAD_INITIALIZER(cn_devlist);
#define CND_INVALID(cnd, td) \
(cnd == NULL || cnd->cnd_vp == NULL || \
(cnd->cnd_vp->v_type == VBAD && !cn_devopen(cnd, td, 1)))
static dev_t cn_udev_t;
SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
&cn_udev_t, sizeof cn_udev_t, "T,struct cdev *", "");
int cons_avail_mask = 0; /* Bit mask. Each registered low level console
* which is currently unavailable for inpit
* (i.e., if it is in graphics mode) will have
* this bit cleared.
*/
static int cn_mute;
static int openflag; /* how /dev/console was opened */
static int cn_is_open;
static char *consbuf; /* buffer used by `consmsgbuf' */
static struct callout conscallout; /* callout for outputting to constty */
struct msgbuf consmsgbuf; /* message buffer for console tty */
static u_char console_pausing; /* pause after each line during probe */
static char *console_pausestr=
"<pause; press any key to proceed to next line or '.' to end pause mode>";
struct tty *constty; /* pointer to console "window" tty */
static void constty_timeout(void *arg);
CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
SET_DECLARE(cons_set, struct consdev);
void
cninit(void)
{
struct consdev *best_cn, *cn, **list;
/*
* 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);
/*
* Find the first console with the highest priority.
*/
best_cn = NULL;
SET_FOREACH(list, cons_set) {
cn = *list;
cnremove(cn);
if (cn->cn_probe == NULL)
continue;
cn->cn_probe(cn);
if (cn->cn_pri == CN_DEAD)
continue;
if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri)
best_cn = cn;
if (boothowto & RB_MULTIPLE) {
/*
* Initialize console, and attach to it.
*/
cnadd(cn);
cn->cn_init(cn);
}
}
if (best_cn == NULL)
return;
if ((boothowto & RB_MULTIPLE) == 0) {
cnadd(best_cn);
best_cn->cn_init(best_cn);
}
if (boothowto & RB_PAUSE)
console_pausing = 1;
/*
* Make the best console the preferred console.
*/
cnselect(best_cn);
}
void
cninit_finish()
{
console_pausing = 0;
}
/* add a new physical console to back the virtual console */
int
cnadd(struct consdev *cn)
{
struct cn_device *cnd;
int i;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
if (cnd->cnd_cn == cn)
return (0);
for (i = 0; i < CNDEVTAB_SIZE; i++) {
cnd = &cn_devtab[i];
if (cnd->cnd_cn == NULL)
break;
}
if (cnd->cnd_cn != NULL)
return (ENOMEM);
cnd->cnd_cn = cn;
if (cn->cn_name[0] == '\0') {
/* XXX: it is unclear if/where this print might output */
printf("WARNING: console at %p has no name\n", cn);
}
STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next);
/* Add device to the active mask. */
cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0);
return (0);
}
void
cnremove(struct consdev *cn)
{
struct cn_device *cnd;
int i;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if (cnd->cnd_cn != cn)
continue;
STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
if (cnd->cnd_vp != NULL)
vn_close(cnd->cnd_vp, openflag, NOCRED, NULL);
cnd->cnd_vp = NULL;
cnd->cnd_cn = NULL;
/* Remove this device from available mask. */
for (i = 0; i < CNDEVTAB_SIZE; i++)
if (cnd == &cn_devtab[i]) {
cons_avail_mask &= ~(1 << i);
break;
}
#if 0
/*
* XXX
* syscons gets really confused if console resources are
* freed after the system has initialized.
*/
if (cn->cn_term != NULL)
cn->cn_term(cn);
#endif
return;
}
}
void
cnselect(struct consdev *cn)
{
struct cn_device *cnd;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if (cnd->cnd_cn != cn)
continue;
if (cnd == STAILQ_FIRST(&cn_devlist))
return;
STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next);
return;
}
}
void
cnavailable(struct consdev *cn, int available)
{
int i;
for (i = 0; i < CNDEVTAB_SIZE; i++) {
if (cn_devtab[i].cnd_cn == cn)
break;
}
if (available) {
if (i < CNDEVTAB_SIZE)
cons_avail_mask |= (1 << i);
cn->cn_flags &= ~CN_FLAG_NOAVAIL;
} else {
if (i < CNDEVTAB_SIZE)
cons_avail_mask &= ~(1 << i);
cn->cn_flags |= CN_FLAG_NOAVAIL;
}
}
int
cnunavailable(void)
{
return (cons_avail_mask == 0);
}
/*
* XXX: rewrite to use sbufs instead
*/
static int
sysctl_kern_console(SYSCTL_HANDLER_ARGS)
{
struct cn_device *cnd;
struct consdev *cp, **list;
char *name, *p;
int delete, len, error;
len = 2;
SET_FOREACH(list, cons_set) {
cp = *list;
if (cp->cn_name[0] != '\0')
len += strlen(cp->cn_name) + 1;
}
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
len += strlen(cnd->cnd_cn->cn_name) + 1;
len = len > CNDEVPATHMAX ? len : CNDEVPATHMAX;
MALLOC(name, char *, len, M_TEMP, M_WAITOK | M_ZERO);
p = name;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
p += sprintf(p, "%s,", cnd->cnd_cn->cn_name);
*p++ = '/';
SET_FOREACH(list, cons_set) {
cp = *list;
if (cp->cn_name[0] != '\0')
p += sprintf(p, "%s,", cp->cn_name);
}
error = sysctl_handle_string(oidp, name, len, req);
if (error == 0 && req->newptr != NULL) {
p = name;
error = ENXIO;
delete = 0;
if (*p == '-') {
delete = 1;
p++;
}
SET_FOREACH(list, cons_set) {
cp = *list;
if (strcmp(p, cp->cn_name) != 0)
continue;
if (delete) {
cnremove(cp);
error = 0;
} else {
error = cnadd(cp);
if (error == 0)
cnselect(cp);
}
break;
}
}
FREE(name, M_TEMP);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, console, CTLTYPE_STRING|CTLFLAG_RW,
0, 0, sysctl_kern_console, "A", "Console device control");
/*
* 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 || req->newptr == NULL)
return (error);
if (ocn_mute && !cn_mute && cn_is_open)
error = cnopen(NULL, openflag, 0, curthread);
else if (!ocn_mute && cn_mute && cn_is_open) {
error = cnclose(NULL, openflag, 0, curthread);
cn_is_open = 1; /* XXX hack */
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
0, sizeof(cn_mute), sysctl_kern_consmute, "I", "");
static int
cn_devopen(struct cn_device *cnd, struct thread *td, int forceopen)
{
char path[CNDEVPATHMAX];
struct nameidata nd;
struct vnode *vp;
struct cdev *dev;
int error;
if ((vp = cnd->cnd_vp) != NULL) {
if (!forceopen && vp->v_type != VBAD) {
dev = vp->v_rdev;
return ((*devsw(dev)->d_open)(dev, openflag, 0, td));
}
cnd->cnd_vp = NULL;
vn_close(vp, openflag, td->td_ucred, td);
}
snprintf(path, sizeof(path), "/dev/%s", cnd->cnd_cn->cn_name);
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, td);
error = vn_open(&nd, &openflag, 0, -1);
if (error == 0) {
NDFREE(&nd, NDF_ONLY_PNBUF);
VOP_UNLOCK(nd.ni_vp, 0, td);
if (nd.ni_vp->v_type == VCHR)
cnd->cnd_vp = nd.ni_vp;
else
vn_close(nd.ni_vp, openflag, td->td_ucred, td);
}
return (cnd->cnd_vp != NULL);
}
static int
cnopen(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct cn_device *cnd;
openflag = flag | FWRITE; /* XXX */
cn_is_open = 1; /* console is logically open */
if (cn_mute)
return (0);
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
cn_devopen(cnd, td, 0);
return (0);
}
static int
cnclose(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct cn_device *cnd;
struct vnode *vp;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
if ((vp = cnd->cnd_vp) == NULL)
continue;
cnd->cnd_vp = NULL;
vn_close(vp, openflag, td->td_ucred, td);
}
cn_is_open = 0;
return (0);
}
static int
cnread(struct cdev *dev, struct uio *uio, int flag)
{
struct cn_device *cnd;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
return (0);
dev = cnd->cnd_vp->v_rdev;
return ((*devsw(dev)->d_read)(dev, uio, flag));
}
static int
cnwrite(struct cdev *dev, struct uio *uio, int flag)
{
struct cn_device *cnd;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
goto done;
if (constty)
dev = constty->t_dev;
else
dev = cnd->cnd_vp->v_rdev;
if (dev != NULL) {
log_console(uio);
return ((*devsw(dev)->d_write)(dev, uio, flag));
}
done:
uio->uio_resid = 0; /* dump the data */
return (0);
}
static int
cnioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct cn_device *cnd;
int error;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, td))
return (0);
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty) {
error = suser(td);
if (error)
return (error);
constty = NULL;
return (0);
}
dev = cnd->cnd_vp->v_rdev;
if (dev != NULL)
return ((*devsw(dev)->d_ioctl)(dev, cmd, data, flag, td));
return (0);
}
/*
* XXX
* poll/kqfilter do not appear to be correct
*/
static int
cnpoll(struct cdev *dev, int events, struct thread *td)
{
struct cn_device *cnd;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, td))
return (0);
dev = cnd->cnd_vp->v_rdev;
if (dev != NULL)
return ((*devsw(dev)->d_poll)(dev, events, td));
return (0);
}
static int
cnkqfilter(struct cdev *dev, struct knote *kn)
{
struct cn_device *cnd;
cnd = STAILQ_FIRST(&cn_devlist);
if (cn_mute || CND_INVALID(cnd, curthread))
return (EINVAL);
dev = cnd->cnd_vp->v_rdev;
if (dev != NULL)
return ((*devsw(dev)->d_kqfilter)(dev, kn));
return (ENXIO);
}
/*
* Low level console routines.
*/
int
cngetc(void)
{
int c;
if (cn_mute)
return (-1);
while ((c = cncheckc()) == -1)
;
if (c == '\r')
c = '\n'; /* console input is always ICRNL */
return (c);
}
int
cncheckc(void)
{
struct cn_device *cnd;
struct consdev *cn;
int c;
if (cn_mute)
return (-1);
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
cn = cnd->cnd_cn;
if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
c = cn->cn_checkc(cn);
if (c != -1) {
return (c);
}
}
}
return (-1);
}
void
cnputc(int c)
{
struct cn_device *cnd;
struct consdev *cn;
char *cp;
if (cn_mute || c == '\0')
return;
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
cn = cnd->cnd_cn;
if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
if (c == '\n')
cn->cn_putc(cn, '\r');
cn->cn_putc(cn, c);
}
}
if (console_pausing && c == '\n' && !kdb_active) {
for (cp = console_pausestr; *cp != '\0'; cp++)
cnputc(*cp);
if (cngetc() == '.')
console_pausing = 0;
cnputc('\r');
for (cp = console_pausestr; *cp != '\0'; cp++)
cnputc(' ');
cnputc('\r');
}
}
void
cndbctl(int on)
{
struct cn_device *cnd;
struct consdev *cn;
static int refcount;
if (!on)
refcount--;
if (refcount == 0)
STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
cn = cnd->cnd_cn;
if (cn->cn_dbctl != NULL)
cn->cn_dbctl(cn, on);
}
if (on)
refcount++;
}
static int consmsgbuf_size = 8192;
SYSCTL_INT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RW, &consmsgbuf_size, 0,
"");
/*
* Redirect console output to a tty.
*/
void
constty_set(struct tty *tp)
{
int size;
KASSERT(tp != NULL, ("constty_set: NULL tp"));
if (consbuf == NULL) {
size = consmsgbuf_size;
consbuf = malloc(size, M_TTYS, M_WAITOK);
msgbuf_init(&consmsgbuf, consbuf, size);
callout_init(&conscallout, 0);
}
constty = tp;
constty_timeout(NULL);
}
/*
* Disable console redirection to a tty.
*/
void
constty_clear(void)
{
int c;
constty = NULL;
if (consbuf == NULL)
return;
callout_stop(&conscallout);
while ((c = msgbuf_getchar(&consmsgbuf)) != -1)
cnputc(c);
free(consbuf, M_TTYS);
consbuf = NULL;
}
/* Times per second to check for pending console tty messages. */
static int constty_wakeups_per_second = 5;
SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW,
&constty_wakeups_per_second, 0, "");
static void
constty_timeout(void *arg)
{
int c;
while (constty != NULL && (c = msgbuf_getchar(&consmsgbuf)) != -1) {
if (tputchar(c, constty) < 0)
constty = NULL;
}
if (constty != NULL) {
callout_reset(&conscallout, hz / constty_wakeups_per_second,
constty_timeout, NULL);
} else {
/* Deallocate the constty buffer memory. */
constty_clear();
}
}
static void
cn_drvinit(void *unused)
{
make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "console");
}
SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, cn_drvinit, NULL)