/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1990, 1993
* 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. 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: Utah $Hdr: cons.c 1.7 92/01/21$
*
* @(#)cons.c 8.2 (Berkeley) 1/12/94
*/
/*
* This is a point that we should have KASSERT(cold) or add
* synchronization in case this can happen after cold boot.
* However, cn_tab initialization is so critical to any
* diagnostics or debugging that we need to tread carefully
* about introducing new ways to crash. So let's put the
* assertion in only after we've audited most or all of the
* cn_tab updates.
*/
cn_tab = tab;
}
int
cnopen(dev_t dev, int flag, int mode, struct lwp *l)
{
dev_t cndev;
int unit, error;
unit = minor(dev);
if (unit > 1)
return ENODEV;
mutex_enter(&cn_lock);
if (cn_tab == NULL) {
error = 0;
goto out;
}
/*
* always open the 'real' console device, so we don't get nailed
* later. This follows normal device semantics; they always get
* open() calls.
*/
cndev = cn_tab->cn_dev;
#if NNULLCONS > 0
if (cndev == NODEV) {
nullconsattach(0);
}
#else /* NNULLCONS > 0 */
if (cndev == NODEV) {
/*
* This is most likely an error in the console attach
* code. Panicking looks better than jumping into nowhere
* through cdevsw below....
*/
panic("cnopen: no console device");
}
#endif /* NNULLCONS > 0 */
if (dev == cndev) {
/*
* This causes cnopen() to be called recursively, which
* is generally a bad thing. It is often caused when
* dev == 0 and cn_dev has not been set, but was probably
* initialised to 0.
*/
panic("cnopen: cn_tab->cn_dev == dev");
}
if (cn_devvp[unit] != NULLVP) {
error = 0;
goto out;
}
if ((error = cdevvp(cndev, &cn_devvp[unit])) != 0) {
printf("cnopen: unable to get vnode reference\n");
goto out;
}
vn_lock(cn_devvp[unit], LK_EXCLUSIVE | LK_RETRY);
error = VOP_OPEN(cn_devvp[unit], flag, kauth_cred_get());
VOP_UNLOCK(cn_devvp[unit]);
out: mutex_exit(&cn_lock);
return error;
}
int
cnclose(dev_t dev, int flag, int mode, struct lwp *l)
{
struct vnode *vp;
int unit, error;
int
cnread(dev_t dev, struct uio *uio, int flag)
{
struct tty *ctp = NULL;
int error;
/*
* If we would redirect input, punt. This will keep strange
* things from happening to people who are using the real
* console. Nothing should be using /dev/console for
* input (except a shell in single-user mode, but then,
* one wouldn't TIOCCONS then).
*/
if (!cn_redirect(&dev, 1, &error, &ctp))
return error;
error = cdev_read(dev, uio, flag);
cn_release(ctp);
return error;
}
int
cnwrite(dev_t dev, struct uio *uio, int flag)
{
struct tty *ctp = NULL;
int error;
int
cnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
struct tty *ctp = NULL;
int error;
error = 0;
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS) {
struct tty *tp;
mutex_enter(&constty_lock);
tp = atomic_load_relaxed(&constty);
if (tp == NULL) {
mutex_exit(&constty_lock);
goto passthrough; /* XXX ??? */
}
error = kauth_authorize_device_tty(l->l_cred,
KAUTH_DEVICE_TTY_VIRTUAL, tp);
if (!error)
atomic_store_relaxed(&constty, NULL);
mutex_exit(&constty_lock);
return error;
}
passthrough:
/*
* Redirect the ioctl, if that's appropriate.
* Note that strange things can happen, if a program does
* ioctls on /dev/console, then the console is redirected
* out from under it.
*/
if (!cn_redirect(&dev, 0, &error, &ctp))
return error;
error = cdev_ioctl(dev, cmd, data, flag, l);
cn_release(ctp);
return error;
}
/*ARGSUSED*/
int
cnpoll(dev_t dev, int events, struct lwp *l)
{
struct tty *ctp = NULL;
int error;
/*
* Redirect the poll, if that's appropriate.
* I don't want to think of the possible side effects
* of console redirection here.
*/
if (!cn_redirect(&dev, 0, &error, &ctp))
return POLLHUP;
error = cdev_poll(dev, events, l);
cn_release(ctp);
return error;
}
/*ARGSUSED*/
int
cnkqfilter(dev_t dev, struct knote *kn)
{
struct tty *ctp = NULL;
int error;
/*
* Redirect the kqfilter, if that's appropriate.
* I don't want to think of the possible side effects
* of console redirection here.
*/
if (!cn_redirect(&dev, 0, &error, &ctp))
return error;
error = cdev_kqfilter(dev, kn);
cn_release(ctp);
return error;
}
int
cngetc(void)
{
if (cn_tab == NULL)
return (0);
int s = splhigh();
for (;;) {
const int rv = (*cn_tab->cn_getc)(cn_tab->cn_dev);
if (rv >= 0) {
splx(s);
return rv;
}
docritpollhooks();
}
}
int
cngetsn(char *cp, int size)
{
char *lp;
int c, len;
cnpollc(1);
lp = cp;
len = 0;
for (;;) {
c = cngetc();
switch (c) {
case '\n':
case '\r':
printf("\n");
*lp++ = '\0';
cnpollc(0);
return (len);
case '\b':
case '\177':
case '#':
if (len) {
--len;
--lp;
printf("\b \b");
}
continue;
case '@':
case 'u'&037: /* CTRL-u */
len = 0;
lp = cp;
printf("\n");
continue;
default:
if (len + 1 >= size || c < ' ') {
printf("\007");
continue;
}
printf("%c", c);
++len;
*lp++ = c;
}
}
}
void
cnputc(int c)
{
if (cn_tab == NULL)
return;
/*
* XXX
* for some reason this causes ARCS firmware to output an endless stream of
* whitespaces with n32 kernels, so use the pre-1.74 code for now until I can
* figure out why this happens
*/
#ifndef sgimips
if (c) {
if (c == '\n') {
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
docritpollhooks();
}
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
}
#else
if (c) {
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
if (c == '\n') {
docritpollhooks();
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
}
}
#endif
}
void
cnpollc(int on)
{
static int refcount = 0;
if (cn_tab == NULL)
return;
if (!on)
--refcount;
if (refcount == 0) {
if (on) {
/*
* Bind to the current CPU by disabling
* preemption (more convenient than finding a
* place to store a stack to unwind for
* curlwp_bind/bindx, and preemption wouldn't
* happen anyway while spinning at high IPL in
* cngetc) so that curcpu() is stable so that
* we can suspend heartbeat checks for it.
*/
kpreempt_disable();
heartbeat_suspend();
}
(*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
if (!on) {
heartbeat_resume();
kpreempt_enable();
}
}
if (on)
++refcount;
}
/*
* Redirect output, if that's appropriate. If there's no real console,
* return ENXIO.
*/
static bool
cn_redirect(dev_t *devp, int is_read, int *error, struct tty **ctpp)
{
dev_t dev = *devp;
struct tty *ctp;
int s;
bool ok = false;
*error = ENXIO;
*ctpp = NULL;
s = pserialize_read_enter();
if ((ctp = atomic_load_consume(&constty)) != NULL && minor(dev) == 0 &&
(cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) {
if (is_read) {
*error = 0;
goto out;
}
tty_acquire(ctp);
*ctpp = ctp;
dev = ctp->t_dev;
} else if (cn_tab == NULL)
goto out;
else
dev = cn_tab->cn_dev;
ok = true;
*devp = dev;
out: pserialize_read_exit(s);
return ok;
}
static void
cn_release(struct tty *ctp)
{
if (ctp == NULL)
return;
tty_release(ctp);
}
MODULE(MODULE_CLASS_DRIVER, cons, NULL);
static int
cons_modcmd(modcmd_t cmd, void *arg)
{
switch (cmd) {
case MODULE_CMD_INIT:
mutex_init(&cn_lock, MUTEX_DEFAULT, IPL_NONE);
return 0;
case MODULE_CMD_FINI:
mutex_destroy(&cn_lock);
return 0;
default:
return ENOTTY;
}
}
