cons.c revision 361ed64a5abddd9ed26f47e25824bbce82557ab4
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Indirect console driver for Sun.
*
* Redirects all I/O to the device designated as the underlying "hardware"
* console, as given by the value of rconsvp. The implementation assumes that
* rconsvp denotes a STREAMS device; the assumption is justified since
* consoles must be capable of effecting tty semantics.
*
* rconsvp is set in autoconf.c:consconfig(), based on information obtained
* from the EEPROM.
*
* XXX: The driver still needs to be converted to use ANSI C consistently
* throughout.
*/
#include <sys/types.h>
#include <sys/open.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signal.h>
#include <sys/cred.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/disp.h>
#include <sys/file.h>
#include <sys/taskq.h>
#include <sys/log.h>
#include <sys/vnode.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <sys/console.h>
#include <sys/consdev.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/poll.h>
#include <sys/debug.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
static int cnopen(dev_t *, int, int, struct cred *);
static int cnclose(dev_t, int, int, struct cred *);
static int cnread(dev_t, struct uio *, struct cred *);
static int cnwrite(dev_t, struct uio *, struct cred *);
static int cnioctl(dev_t, int, intptr_t, int, struct cred *, int *);
static int cnpoll(dev_t, short, int, short *, struct pollhead **);
static int cn_info(dev_info_t *, ddi_info_cmd_t, void *, void **);
static int cn_attach(dev_info_t *, ddi_attach_cmd_t);
static int cn_detach(dev_info_t *, ddi_detach_cmd_t);
static dev_info_t *cn_dip; /* private copy of devinfo pointer */
static struct cb_ops cn_cb_ops = {
cnopen, /* open */
cnclose, /* close */
nodev, /* strategy */
nodev, /* print */
nodev, /* dump */
cnread, /* read */
cnwrite, /* write */
cnioctl, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
cnpoll, /* poll */
ddi_prop_op, /* cb_prop_op */
0, /* streamtab */
D_NEW | D_MP /* Driver compatibility flag */
};
static struct dev_ops cn_ops = {
DEVO_REV, /* devo_rev, */
0, /* refcnt */
cn_info, /* info */
nulldev, /* identify */
nulldev, /* probe */
cn_attach, /* attach */
cn_detach, /* detach */
nodev, /* reset */
&cn_cb_ops, /* driver operations */
(struct bus_ops *)0, /* bus operations */
NULL, /* power */
ddi_quiesce_not_needed, /* quiesce */
};
/*
* Global variables associated with the console device:
*
* XXX: There are too many of these!
* moved to space.c to become resident in the kernel so that cons
* can be loadable.
*/
extern dev_t rconsdev; /* "hardware" console */
extern vnode_t *rconsvp; /* pointer to vnode for that device */
/*
* XXX: consulted in prsubr.c, for /proc entry point for obtaining ps info.
*/
extern dev_t uconsdev; /* What the user thinks is the console device */
/*
* Private driver state:
*/
/*
* The underlying console device potentially can be opened through (at least)
* two paths: through this driver and through the underlying device's driver.
* To ensure that reference counts are meaningful and therefore that close
* routines are called at the right time, it's important to make sure that
* rconsvp's s_count field (i.e., the count on the underlying device) never
* has a contribution of more than one through this driver, regardless of how
* many times this driver's been opened. rconsopen keeps track of the
* necessary information to ensure this property.
*/
static uint_t rconsopen;
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/modctl.h>
extern int nodev(), nulldev();
extern int dseekneg_flag;
extern struct mod_ops mod_driverops;
extern struct dev_ops cn_ops;
/*
* Module linkage information for the kernel.
*/
static struct modldrv modldrv = {
&mod_driverops, /* Type of module. This one is a pseudo driver */
"Console redirection driver",
&cn_ops, /* driver ops */
};
static struct modlinkage modlinkage = {
MODREV_1,
&modldrv,
NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_fini(void)
{
return (EBUSY);
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
/*
* DDI glue routines
*/
static int
cn_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
if (cmd != DDI_ATTACH)
return (DDI_FAILURE);
if (ddi_create_minor_node(devi, "syscon", S_IFCHR,
0, DDI_PSEUDO, NULL) == DDI_FAILURE) {
return (DDI_FAILURE);
}
if (ddi_create_minor_node(devi, "systty", S_IFCHR,
0, DDI_PSEUDO, NULL) == DDI_FAILURE) {
ddi_remove_minor_node(devi, NULL);
return (DDI_FAILURE);
}
if (ddi_create_minor_node(devi, "console", S_IFCHR,
0, DDI_PSEUDO, NULL) == DDI_FAILURE) {
ddi_remove_minor_node(devi, NULL);
return (DDI_FAILURE);
}
cn_dip = devi;
return (DDI_SUCCESS);
}
static int
cn_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
if (cmd != DDI_DETACH)
return (DDI_FAILURE);
ddi_remove_minor_node(devi, NULL);
uconsdev = NODEV;
return (DDI_SUCCESS);
}
/* ARGSUSED */
static int
cn_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
int error = DDI_FAILURE;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
if (getminor((dev_t)arg) == 0 && cn_dip != NULL) {
*result = (void *) cn_dip;
error = DDI_SUCCESS;
}
break;
case DDI_INFO_DEVT2INSTANCE:
if (getminor((dev_t)arg) == 0) {
*result = (void *)0;
error = DDI_SUCCESS;
}
break;
default:
break;
}
return (error);
}
/*
* XXX Caution: before allowing more than 256 minor devices on the
* console, make sure you understand the 'compatibility' hack
* in ufs_iget() that translates old dev_t's to new dev_t's.
* See bugid 1098104 for the sordid details.
*/
/* ARGSUSED */
static int
cnopen(dev_t *dev, int flag, int state, struct cred *cred)
{
int err;
static int been_here;
vnode_t *vp = rconsvp;
ASSERT(cred != NULL);
if (rconsvp == NULL)
return (0);
/*
* Enable virtual console I/O for console logging if needed.
*/
if (vsconsvp != NULL && vsconsvp->v_stream == NULL) {
if (VOP_OPEN(&vsconsvp, FREAD | FWRITE, cred, NULL) != 0) {
cmn_err(CE_WARN, "cnopen: failed to open vsconsvp "
"for virtual console logging");
}
}
/*
* XXX: Clean up inactive PIDs from previous opens if any.
* These would have been created as a result of an I_SETSIG
* issued against console. This is a workaround, and
* console driver must be correctly redesigned not to need
* this hook.
*/
if (vp->v_stream) {
str_cn_clean(vp);
}
/*
* XXX: Set hook to tell /proc about underlying console. (There's
* gotta be a better way...)
*/
if (state != OTYP_CHR || getminor(*dev) != 0)
return (ENXIO);
if (been_here == 0) {
uconsdev = *dev;
been_here = 1;
if (vn_open("/dev/console", UIO_SYSSPACE, FWRITE | FNOCTTY,
0, &console_vnode, 0, 0) == 0)
console_taskq = taskq_create("console_taskq",
1, maxclsyspri - 1, LOG_LOWAT / LOG_MSGSIZE,
LOG_HIWAT / LOG_MSGSIZE, TASKQ_PREPOPULATE);
}
if ((err = VOP_OPEN(&vp, flag, cred, NULL)) != 0)
return (err);
/*
* The underlying driver is not allowed to have cloned itself
* for this open.
*/
if (vp != rconsvp) {
/*
* It might happen that someone set rconsvp to NULL
* whilst we were in the middle of the open.
*/
if (rconsvp == NULL) {
(void) VOP_CLOSE(vp, flag, 1, (offset_t)0, cred, NULL);
return (0);
}
cmn_err(CE_PANIC, "cnopen: cloned open");
}
rconsopen++;
return (0);
}
/* ARGSUSED */
static int
cnclose(dev_t dev, int flag, int state, struct cred *cred)
{
int err = 0;
vnode_t *vp;
/*
* Since this is the _last_ close, it's our last chance to close the
* underlying device. (Note that if someone else has the underlying
* hardware console device open, we won't get here, since spec_close
* will see s_count > 1.)
*/
if (state != OTYP_CHR)
return (ENXIO);
if (rconsvp == NULL)
return (0);
while ((rconsopen != 0) && ((vp = rconsvp) != NULL)) {
err = VOP_CLOSE(vp, flag, 1, (offset_t)0, cred, NULL);
if (!err) {
rconsopen--;
}
}
return (err);
}
/* ARGSUSED */
static int
cnread(dev_t dev, struct uio *uio, struct cred *cred)
{
kcondvar_t sleep_forever;
kmutex_t sleep_forever_mutex;
if (rconsvp == NULL) {
/*
* Go to sleep forever. This seems like the least
* harmful thing to do if there's no console.
* EOF might be better if we're ending up single-user
* mode.
*/
cv_init(&sleep_forever, NULL, CV_DRIVER, NULL);
mutex_init(&sleep_forever_mutex, NULL, MUTEX_DRIVER, NULL);
mutex_enter(&sleep_forever_mutex);
(void) cv_wait_sig(&sleep_forever, &sleep_forever_mutex);
mutex_exit(&sleep_forever_mutex);
return (EIO);
}
if (rconsvp->v_stream != NULL)
return (strread(rconsvp, uio, cred));
else
return (cdev_read(rconsdev, uio, cred));
}
/* ARGSUSED */
static int
cnwrite(dev_t dev, struct uio *uio, struct cred *cred)
{
if (rconsvp == NULL) {
uio->uio_resid = 0;
return (0);
}
/*
* Output to virtual console for logging if enabled.
*/
if (vsconsvp != NULL && vsconsvp->v_stream != NULL) {
struiod_t uiod;
/*
* strwrite modifies uio so need to make copy.
*/
(void) uiodup(uio, &uiod.d_uio, uiod.d_iov,
sizeof (uiod.d_iov) / sizeof (*uiod.d_iov));
(void) strwrite(vsconsvp, &uiod.d_uio, cred);
}
if (rconsvp->v_stream != NULL)
return (strwrite(rconsvp, uio, cred));
else
return (cdev_write(rconsdev, uio, cred));
}
/* ARGSUSED */
static int
cnprivateioc(dev_t dev, int cmd, intptr_t arg, int flag, struct cred *cred,
int *rvalp)
{
/* currently we only support one ioctl */
if (cmd != CONS_GETTERM)
return (EINVAL);
/* Confirm iwscn is immediate target of cn redirection */
if (rconsvp != wsconsvp)
return (ENODEV);
/*
* If the redirection client is not wc, it should return
* error upon receiving the CONS_GETTERM ioctl.
*
* if it is wc, we know that the target supports the CONS_GETTERM
* ioctl, which very conviently has the exact same data
* format as this ioctl... so let's just pass it on.
*/
return (cdev_ioctl(rconsdev, CONS_GETTERM, arg, flag, cred, rvalp));
}
/* ARGSUSED */
static int
cnioctl(dev_t dev, int cmd, intptr_t arg, int flag, struct cred *cred,
int *rvalp)
{
if (rconsvp == NULL)
return (0);
if ((cmd & _CNIOC_MASK) == _CNIOC)
return (cnprivateioc(dev, cmd, arg, flag, cred, rvalp));
else if (rconsvp->v_stream != NULL)
return (strioctl(rconsvp, cmd, arg, flag, U_TO_K, cred,
rvalp));
else
return (cdev_ioctl(rconsdev, cmd, arg, flag, cred, rvalp));
}
/* ARGSUSED */
static int
cnpoll(dev_t dev, short events, int anyyet, short *reventsp,
struct pollhead **phpp)
{
if (rconsvp == NULL)
return (nochpoll(dev, events, anyyet, reventsp, phpp));
if (rconsvp->v_stream != NULL)
return (strpoll(rconsvp->v_stream, events, anyyet, reventsp,
phpp));
else
return (cdev_poll(rconsdev, events, anyyet, reventsp, phpp));
}