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freebsd-skq/sys/kern/tty.c
Ed Schouten c0086bf202 Serialize write() calls on TTYs. 
Just like the old TTY layer, the current MPSAFE TTY layer does not make
any attempt to serialize calls of write(). Data is copied into the
kernel in 256 (TTY_STACKBUF) byte chunks. If a write() call occurs at
the same time, the data may interleave. This is especially likely when
the TTY starts blocking, because the output queue reaches the high
watermark.

I've implemented this by adding a new flag, TTY_BUSY_OUT, which is used
to mark a TTY as having a thread stuck in write(). Because I don't want
non-blocking processes to be possibly blocked by a sleeping thread, I'm
still allowing it to bypass the protection. According to this message,
the Linux kernel returns EAGAIN in such cases, but I think that's a
little too restrictive:

	http://kerneltrap.org/index.php?q=mailarchive/linux-kernel/2007/5/2/85418/thread

PR:		kern/118287
2009-02-11 16:28:49 +00:00

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/*-
* Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Portions of this software were developed under sponsorship from Snow
* B.V., the Netherlands.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#ifdef COMPAT_43TTY
#include <sys/ioctl_compat.h>
#endif /* COMPAT_43TTY */
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/poll.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/serial.h>
#include <sys/signal.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/ttycom.h>
#define TTYDEFCHARS
#include <sys/ttydefaults.h>
#undef TTYDEFCHARS
#include <sys/ucred.h>
#include <sys/vnode.h>
#include <machine/stdarg.h>
static MALLOC_DEFINE(M_TTY, "tty", "tty device");
static void tty_rel_free(struct tty *tp);
static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
static struct sx tty_list_sx;
SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
static unsigned int tty_list_count = 0;
/* Character device of /dev/console. */
static struct cdev *dev_console;
static const char *dev_console_filename;
/*
* Flags that are supported and stored by this implementation.
*/
#define TTYSUP_IFLAG (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
#define TTYSUP_OFLAG (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
#define TTYSUP_LFLAG (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
FLUSHO|NOKERNINFO|NOFLSH)
#define TTYSUP_CFLAG (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
CDSR_OFLOW|CCAR_OFLOW)
#define TTY_CALLOUT(tp,d) ((d) != (tp)->t_dev && (d) != dev_console)
/*
* Set TTY buffer sizes.
*/
#define TTYBUF_MAX 65536
static void
tty_watermarks(struct tty *tp)
{
size_t bs;
/* Provide an input buffer for 0.2 seconds of data. */
bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
ttyinq_setsize(&tp->t_inq, tp, bs);
/* Set low watermark at 10% (when 90% is available). */
tp->t_inlow = (ttyinq_getsize(&tp->t_inq) * 9) / 10;
/* Provide an ouput buffer for 0.2 seconds of data. */
bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
ttyoutq_setsize(&tp->t_outq, tp, bs);
/* Set low watermark at 10% (when 90% is available). */
tp->t_outlow = (ttyoutq_getsize(&tp->t_outq) * 9) / 10;
}
static int
tty_drain(struct tty *tp)
{
int error;
if (ttyhook_hashook(tp, getc_inject))
/* buffer is inaccessible */
return (0);
while (ttyoutq_bytesused(&tp->t_outq) > 0) {
ttydevsw_outwakeup(tp);
/* Could be handled synchronously. */
if (ttyoutq_bytesused(&tp->t_outq) == 0)
return (0);
/* Wait for data to be drained. */
error = tty_wait(tp, &tp->t_outwait);
if (error)
return (error);
}
return (0);
}
/*
* Though ttydev_enter() and ttydev_leave() seem to be related, they
* don't have to be used together. ttydev_enter() is used by the cdev
* operations to prevent an actual operation from being processed when
* the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
* and ttydev_close() to determine whether per-TTY data should be
* deallocated.
*/
static __inline int
ttydev_enter(struct tty *tp)
{
tty_lock(tp);
if (tty_gone(tp) || !tty_opened(tp)) {
/* Device is already gone. */
tty_unlock(tp);
return (ENXIO);
}
return (0);
}
static void
ttydev_leave(struct tty *tp)
{
tty_lock_assert(tp, MA_OWNED);
if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
/* Device is still opened somewhere. */
tty_unlock(tp);
return;
}
tp->t_flags |= TF_OPENCLOSE;
/* Stop asynchronous I/O. */
funsetown(&tp->t_sigio);
/* Remove console TTY. */
if (constty == tp)
constty_clear();
/* Drain any output. */
MPASS((tp->t_flags & TF_STOPPED) == 0);
if (!tty_gone(tp))
tty_drain(tp);
ttydisc_close(tp);
/* Destroy associated buffers already. */
ttyinq_free(&tp->t_inq);
tp->t_inlow = 0;
ttyoutq_free(&tp->t_outq);
tp->t_outlow = 0;
knlist_clear(&tp->t_inpoll.si_note, 1);
knlist_clear(&tp->t_outpoll.si_note, 1);
if (!tty_gone(tp))
ttydevsw_close(tp);
tp->t_flags &= ~TF_OPENCLOSE;
tty_rel_free(tp);
}
/*
* Operations that are exposed through the character device in /dev.
*/
static int
ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct tty *tp = dev->si_drv1;
int error = 0;
/* Disallow access when the TTY belongs to a different prison. */
if (dev->si_cred != NULL &&
dev->si_cred->cr_prison != td->td_ucred->cr_prison &&
priv_check(td, PRIV_TTY_PRISON)) {
return (EPERM);
}
tty_lock(tp);
if (tty_gone(tp)) {
/* Device is already gone. */
tty_unlock(tp);
return (ENXIO);
}
/*
* Prevent the TTY from being opened when being torn down or
* built up by unrelated processes.
*/
if (tp->t_flags & TF_OPENCLOSE) {
tty_unlock(tp);
return (EBUSY);
}
tp->t_flags |= TF_OPENCLOSE;
/*
* Make sure the "tty" and "cua" device cannot be opened at the
* same time.
*/
if (TTY_CALLOUT(tp, dev)) {
if (tp->t_flags & TF_OPENED_IN) {
error = EBUSY;
goto done;
}
} else {
if (tp->t_flags & TF_OPENED_OUT) {
error = EBUSY;
goto done;
}
}
if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
error = EBUSY;
goto done;
}
if (!tty_opened(tp)) {
/* Set proper termios flags. */
if (TTY_CALLOUT(tp, dev)) {
tp->t_termios = tp->t_termios_init_out;
} else {
tp->t_termios = tp->t_termios_init_in;
}
ttydevsw_param(tp, &tp->t_termios);
ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
error = ttydevsw_open(tp);
if (error != 0)
goto done;
ttydisc_open(tp);
tty_watermarks(tp);
}
/* Wait for Carrier Detect. */
if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
(tp->t_termios.c_cflag & CLOCAL) == 0) {
while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
error = tty_wait(tp, &tp->t_dcdwait);
if (error != 0)
goto done;
}
}
if (dev == dev_console)
tp->t_flags |= TF_OPENED_CONS;
else if (TTY_CALLOUT(tp, dev))
tp->t_flags |= TF_OPENED_OUT;
else
tp->t_flags |= TF_OPENED_IN;
done: tp->t_flags &= ~TF_OPENCLOSE;
ttydev_leave(tp);
return (error);
}
static int
ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
{
struct tty *tp = dev->si_drv1;
tty_lock(tp);
/*
* Don't actually close the device if it is being used as the
* console.
*/
MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
if (dev == dev_console)
tp->t_flags &= ~TF_OPENED_CONS;
else
tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
if (tp->t_flags & TF_OPENED) {
tty_unlock(tp);
return (0);
}
/*
* This can only be called once. The callin and the callout
* devices cannot be opened at the same time.
*/
tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
/* Properly wake up threads that are stuck - revoke(). */
tp->t_revokecnt++;
tty_wakeup(tp, FREAD|FWRITE);
cv_broadcast(&tp->t_bgwait);
ttydev_leave(tp);
return (0);
}
static __inline int
tty_is_ctty(struct tty *tp, struct proc *p)
{
tty_lock_assert(tp, MA_OWNED);
return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
}
static int
tty_wait_background(struct tty *tp, struct thread *td, int sig)
{
struct proc *p = td->td_proc;
struct pgrp *pg;
int error;
MPASS(sig == SIGTTIN || sig == SIGTTOU);
tty_lock_assert(tp, MA_OWNED);
for (;;) {
PROC_LOCK(p);
/*
* The process should only sleep, when:
* - This terminal is the controling terminal
* - Its process group is not the foreground process
* group
* - The parent process isn't waiting for the child to
* exit
* - the signal to send to the process isn't masked
*/
if (!tty_is_ctty(tp, p) ||
p->p_pgrp == tp->t_pgrp || p->p_flag & P_PPWAIT ||
SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
SIGISMEMBER(td->td_sigmask, sig)) {
/* Allow the action to happen. */
PROC_UNLOCK(p);
return (0);
}
/*
* Send the signal and sleep until we're the new
* foreground process group.
*/
pg = p->p_pgrp;
PROC_UNLOCK(p);
if (pg->pg_jobc == 0)
return (EIO);
PGRP_LOCK(pg);
pgsignal(pg, sig, 1);
PGRP_UNLOCK(pg);
error = tty_wait(tp, &tp->t_bgwait);
if (error)
return (error);
}
}
static int
ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
{
struct tty *tp = dev->si_drv1;
int error;
error = ttydev_enter(tp);
if (error)
goto done;
error = tty_wait_background(tp, curthread, SIGTTIN);
if (error) {
tty_unlock(tp);
goto done;
}
error = ttydisc_read(tp, uio, ioflag);
tty_unlock(tp);
/*
* The read() call should not throw an error when the device is
* being destroyed. Silently convert it to an EOF.
*/
done: if (error == ENXIO)
error = 0;
return (error);
}
static int
ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
{
struct tty *tp = dev->si_drv1;
int error;
error = ttydev_enter(tp);
if (error)
return (error);
if (tp->t_termios.c_lflag & TOSTOP) {
error = tty_wait_background(tp, curthread, SIGTTOU);
if (error)
goto done;
}
if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
/* Allow non-blocking writes to bypass serialization. */
error = ttydisc_write(tp, uio, ioflag);
} else {
/* Serialize write() calls. */
while (tp->t_flags & TF_BUSY_OUT) {
error = tty_wait(tp, &tp->t_bgwait);
if (error)
goto done;
}
tp->t_flags |= TF_BUSY_OUT;
error = ttydisc_write(tp, uio, ioflag);
tp->t_flags &= ~TF_BUSY_OUT;
cv_broadcast(&tp->t_bgwait);
}
done: tty_unlock(tp);
return (error);
}
static int
ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
struct thread *td)
{
struct tty *tp = dev->si_drv1;
int error;
error = ttydev_enter(tp);
if (error)
return (error);
switch (cmd) {
case TIOCCBRK:
case TIOCCONS:
case TIOCDRAIN:
case TIOCEXCL:
case TIOCFLUSH:
case TIOCNXCL:
case TIOCSBRK:
case TIOCSCTTY:
case TIOCSETA:
case TIOCSETAF:
case TIOCSETAW:
case TIOCSPGRP:
case TIOCSTART:
case TIOCSTAT:
case TIOCSTOP:
case TIOCSWINSZ:
#if 0
case TIOCSDRAINWAIT:
case TIOCSETD:
case TIOCSTI:
#endif
#ifdef COMPAT_43TTY
case TIOCLBIC:
case TIOCLBIS:
case TIOCLSET:
case TIOCSETC:
case OTIOCSETD:
case TIOCSETN:
case TIOCSETP:
case TIOCSLTC:
#endif /* COMPAT_43TTY */
/*
* If the ioctl() causes the TTY to be modified, let it
* wait in the background.
*/
error = tty_wait_background(tp, curthread, SIGTTOU);
if (error)
goto done;
}
error = tty_ioctl(tp, cmd, data, td);
done: tty_unlock(tp);
return (error);
}
static int
ttydev_poll(struct cdev *dev, int events, struct thread *td)
{
struct tty *tp = dev->si_drv1;
int error, revents = 0;
error = ttydev_enter(tp);
if (error) {
/* Don't return the error here, but the event mask. */
return (events &
(POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
}
if (events & (POLLIN|POLLRDNORM)) {
/* See if we can read something. */
if (ttydisc_read_poll(tp) > 0)
revents |= events & (POLLIN|POLLRDNORM);
}
if (events & (POLLOUT|POLLWRNORM)) {
/* See if we can write something. */
if (ttydisc_write_poll(tp) > 0)
revents |= events & (POLLOUT|POLLWRNORM);
}
if (tp->t_flags & TF_ZOMBIE)
/* Hangup flag on zombie state. */
revents |= events & POLLHUP;
if (revents == 0) {
if (events & (POLLIN|POLLRDNORM))
selrecord(td, &tp->t_inpoll);
if (events & (POLLOUT|POLLWRNORM))
selrecord(td, &tp->t_outpoll);
}
tty_unlock(tp);
return (revents);
}
static int
ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
{
struct tty *tp = dev->si_drv1;
int error;
/* Handle mmap() through the driver. */
error = ttydev_enter(tp);
if (error)
return (-1);
error = ttydevsw_mmap(tp, offset, paddr, nprot);
tty_unlock(tp);
return (error);
}
/*
* kqueue support.
*/
static void
tty_kqops_read_detach(struct knote *kn)
{
struct tty *tp = kn->kn_hook;
knlist_remove(&tp->t_inpoll.si_note, kn, 0);
}
static int
tty_kqops_read_event(struct knote *kn, long hint)
{
struct tty *tp = kn->kn_hook;
tty_lock_assert(tp, MA_OWNED);
if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
kn->kn_flags |= EV_EOF;
return (1);
} else {
kn->kn_data = ttydisc_read_poll(tp);
return (kn->kn_data > 0);
}
}
static void
tty_kqops_write_detach(struct knote *kn)
{
struct tty *tp = kn->kn_hook;
knlist_remove(&tp->t_outpoll.si_note, kn, 0);
}
static int
tty_kqops_write_event(struct knote *kn, long hint)
{
struct tty *tp = kn->kn_hook;
tty_lock_assert(tp, MA_OWNED);
if (tty_gone(tp)) {
kn->kn_flags |= EV_EOF;
return (1);
} else {
kn->kn_data = ttydisc_write_poll(tp);
return (kn->kn_data > 0);
}
}
static struct filterops tty_kqops_read =
{ 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
static struct filterops tty_kqops_write =
{ 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
static int
ttydev_kqfilter(struct cdev *dev, struct knote *kn)
{
struct tty *tp = dev->si_drv1;
int error;
error = ttydev_enter(tp);
if (error)
return (error);
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_hook = tp;
kn->kn_fop = &tty_kqops_read;
knlist_add(&tp->t_inpoll.si_note, kn, 1);
break;
case EVFILT_WRITE:
kn->kn_hook = tp;
kn->kn_fop = &tty_kqops_write;
knlist_add(&tp->t_outpoll.si_note, kn, 1);
break;
default:
error = EINVAL;
break;
}
tty_unlock(tp);
return (error);
}
static struct cdevsw ttydev_cdevsw = {
.d_version = D_VERSION,
.d_open = ttydev_open,
.d_close = ttydev_close,
.d_read = ttydev_read,
.d_write = ttydev_write,
.d_ioctl = ttydev_ioctl,
.d_kqfilter = ttydev_kqfilter,
.d_poll = ttydev_poll,
.d_mmap = ttydev_mmap,
.d_name = "ttydev",
.d_flags = D_TTY,
};
/*
* Init/lock-state devices
*/
static int
ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct tty *tp = dev->si_drv1;
int error = 0;
tty_lock(tp);
if (tty_gone(tp))
error = ENODEV;
tty_unlock(tp);
return (error);
}
static int
ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
{
return (0);
}
static int
ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
{
return (ENODEV);
}
static int
ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
struct thread *td)
{
struct tty *tp = dev->si_drv1;
int error = 0;
tty_lock(tp);
if (tty_gone(tp)) {
error = ENODEV;
goto done;
}
switch (cmd) {
case TIOCGETA:
/* Obtain terminal flags through tcgetattr(). */
bcopy(dev->si_drv2, data, sizeof(struct termios));
break;
case TIOCSETA:
/* Set terminal flags through tcsetattr(). */
error = priv_check(td, PRIV_TTY_SETA);
if (error)
break;
bcopy(data, dev->si_drv2, sizeof(struct termios));
break;
case TIOCGETD:
*(int *)data = TTYDISC;
break;
case TIOCGWINSZ:
bzero(data, sizeof(struct winsize));
break;
default:
error = ENOTTY;
}
done: tty_unlock(tp);
return (error);
}
static struct cdevsw ttyil_cdevsw = {
.d_version = D_VERSION,
.d_open = ttyil_open,
.d_close = ttyil_close,
.d_read = ttyil_rdwr,
.d_write = ttyil_rdwr,
.d_ioctl = ttyil_ioctl,
.d_name = "ttyil",
.d_flags = D_TTY,
};
static void
tty_init_termios(struct tty *tp)
{
struct termios *t = &tp->t_termios_init_in;
t->c_cflag = TTYDEF_CFLAG;
t->c_iflag = TTYDEF_IFLAG;
t->c_lflag = TTYDEF_LFLAG;
t->c_oflag = TTYDEF_OFLAG;
t->c_ispeed = TTYDEF_SPEED;
t->c_ospeed = TTYDEF_SPEED;
bcopy(ttydefchars, &t->c_cc, sizeof ttydefchars);
tp->t_termios_init_out = *t;
}
void
tty_init_console(struct tty *tp, speed_t s)
{
struct termios *ti = &tp->t_termios_init_in;
struct termios *to = &tp->t_termios_init_out;
if (s != 0) {
ti->c_ispeed = ti->c_ospeed = s;
to->c_ispeed = to->c_ospeed = s;
}
ti->c_cflag |= CLOCAL;
to->c_cflag |= CLOCAL;
}
/*
* Standard device routine implementations, mostly meant for
* pseudo-terminal device drivers. When a driver creates a new terminal
* device class, missing routines are patched.
*/
static int
ttydevsw_defopen(struct tty *tp)
{
return (0);
}
static void
ttydevsw_defclose(struct tty *tp)
{
}
static void
ttydevsw_defoutwakeup(struct tty *tp)
{
panic("Terminal device has output, while not implemented");
}
static void
ttydevsw_definwakeup(struct tty *tp)
{
}
static int
ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
return (ENOIOCTL);
}
static int
ttydevsw_defparam(struct tty *tp, struct termios *t)
{
/* Use a fake baud rate, we're not a real device. */
t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
return (0);
}
static int
ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
{
/* Simulate a carrier to make the TTY layer happy. */
return (SER_DCD);
}
static int
ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
int nprot)
{
return (-1);
}
static void
ttydevsw_defpktnotify(struct tty *tp, char event)
{
}
static void
ttydevsw_deffree(void *softc)
{
panic("Terminal device freed without a free-handler");
}
/*
* TTY allocation and deallocation. TTY devices can be deallocated when
* the driver doesn't use it anymore, when the TTY isn't a session's
* controlling TTY and when the device node isn't opened through devfs.
*/
struct tty *
tty_alloc(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
{
struct tty *tp;
/* Make sure the driver defines all routines. */
#define PATCH_FUNC(x) do { \
if (tsw->tsw_ ## x == NULL) \
tsw->tsw_ ## x = ttydevsw_def ## x; \
} while (0)
PATCH_FUNC(open);
PATCH_FUNC(close);
PATCH_FUNC(outwakeup);
PATCH_FUNC(inwakeup);
PATCH_FUNC(ioctl);
PATCH_FUNC(param);
PATCH_FUNC(modem);
PATCH_FUNC(mmap);
PATCH_FUNC(pktnotify);
PATCH_FUNC(free);
#undef PATCH_FUNC
tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
tp->t_devsw = tsw;
tp->t_devswsoftc = sc;
tp->t_flags = tsw->tsw_flags;
tty_init_termios(tp);
cv_init(&tp->t_inwait, "ttyin");
cv_init(&tp->t_outwait, "ttyout");
cv_init(&tp->t_bgwait, "ttybg");
cv_init(&tp->t_dcdwait, "ttydcd");
/* Allow drivers to use a custom mutex to lock the TTY. */
if (mutex != NULL) {
tp->t_mtx = mutex;
} else {
tp->t_mtx = &tp->t_mtxobj;
mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
}
knlist_init(&tp->t_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
knlist_init(&tp->t_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
sx_xlock(&tty_list_sx);
TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
tty_list_count++;
sx_xunlock(&tty_list_sx);
return (tp);
}
static void
tty_dealloc(void *arg)
{
struct tty *tp = arg;
sx_xlock(&tty_list_sx);
TAILQ_REMOVE(&tty_list, tp, t_list);
tty_list_count--;
sx_xunlock(&tty_list_sx);
/* Make sure we haven't leaked buffers. */
MPASS(ttyinq_getsize(&tp->t_inq) == 0);
MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
knlist_destroy(&tp->t_inpoll.si_note);
knlist_destroy(&tp->t_outpoll.si_note);
cv_destroy(&tp->t_inwait);
cv_destroy(&tp->t_outwait);
cv_destroy(&tp->t_bgwait);
cv_destroy(&tp->t_dcdwait);
if (tp->t_mtx == &tp->t_mtxobj)
mtx_destroy(&tp->t_mtxobj);
ttydevsw_free(tp);
free(tp, M_TTY);
}
static void
tty_rel_free(struct tty *tp)
{
struct cdev *dev;
tty_lock_assert(tp, MA_OWNED);
#define TF_ACTIVITY (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
/* TTY is still in use. */
tty_unlock(tp);
return;
}
/* TTY can be deallocated. */
dev = tp->t_dev;
tp->t_dev = NULL;
tty_unlock(tp);
destroy_dev_sched_cb(dev, tty_dealloc, tp);
}
void
tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
{
MPASS(tp->t_sessioncnt > 0);
tty_lock_assert(tp, MA_OWNED);
if (tp->t_pgrp == pg)
tp->t_pgrp = NULL;
tty_unlock(tp);
}
void
tty_rel_sess(struct tty *tp, struct session *sess)
{
MPASS(tp->t_sessioncnt > 0);
/* Current session has left. */
if (tp->t_session == sess) {
tp->t_session = NULL;
MPASS(tp->t_pgrp == NULL);
}
tp->t_sessioncnt--;
tty_rel_free(tp);
}
void
tty_rel_gone(struct tty *tp)
{
MPASS(!tty_gone(tp));
/* Simulate carrier removal. */
ttydisc_modem(tp, 0);
/* Wake up all blocked threads. */
tty_wakeup(tp, FREAD|FWRITE);
cv_broadcast(&tp->t_bgwait);
cv_broadcast(&tp->t_dcdwait);
tp->t_flags |= TF_GONE;
tty_rel_free(tp);
}
/*
* Exposing information about current TTY's through sysctl
*/
static void
tty_to_xtty(struct tty *tp, struct xtty *xt)
{
tty_lock_assert(tp, MA_OWNED);
xt->xt_size = sizeof(struct xtty);
xt->xt_insize = ttyinq_getsize(&tp->t_inq);
xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
xt->xt_inlow = tp->t_inlow;
xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
xt->xt_outlow = tp->t_outlow;
xt->xt_column = tp->t_column;
xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
xt->xt_flags = tp->t_flags;
xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
}
static int
sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
{
unsigned long lsize;
struct xtty *xtlist, *xt;
struct tty *tp;
int error;
sx_slock(&tty_list_sx);
lsize = tty_list_count * sizeof(struct xtty);
if (lsize == 0) {
sx_sunlock(&tty_list_sx);
return (0);
}
xtlist = xt = malloc(lsize, M_TEMP, M_WAITOK);
TAILQ_FOREACH(tp, &tty_list, t_list) {
tty_lock(tp);
tty_to_xtty(tp, xt);
tty_unlock(tp);
xt++;
}
sx_sunlock(&tty_list_sx);
error = SYSCTL_OUT(req, xtlist, lsize);
free(xtlist, M_TEMP);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
/*
* Device node creation. Device has been set up, now we can expose it to
* the user.
*/
void
tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
{
va_list ap;
struct cdev *dev;
const char *prefix = "tty";
char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
uid_t uid;
gid_t gid;
mode_t mode;
/* Remove "tty" prefix from devices like PTY's. */
if (tp->t_flags & TF_NOPREFIX)
prefix = "";
va_start(ap, fmt);
vsnrprintf(name, sizeof name, 32, fmt, ap);
va_end(ap);
if (cred == NULL) {
/* System device. */
uid = UID_ROOT;
gid = GID_WHEEL;
mode = S_IRUSR|S_IWUSR;
} else {
/* User device. */
uid = cred->cr_ruid;
gid = GID_TTY;
mode = S_IRUSR|S_IWUSR|S_IWGRP;
}
/* Master call-in device. */
dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
uid, gid, mode, "%s%s", prefix, name);
dev->si_drv1 = tp;
tp->t_dev = dev;
/* Slave call-in devices. */
if (tp->t_flags & TF_INITLOCK) {
dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
uid, gid, mode, "%s%s.init", prefix, name);
dev_depends(tp->t_dev, dev);
dev->si_drv1 = tp;
dev->si_drv2 = &tp->t_termios_init_in;
dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
uid, gid, mode, "%s%s.lock", prefix, name);
dev_depends(tp->t_dev, dev);
dev->si_drv1 = tp;
dev->si_drv2 = &tp->t_termios_lock_in;
}
/* Call-out devices. */
if (tp->t_flags & TF_CALLOUT) {
dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
UID_UUCP, GID_DIALER, 0660, "cua%s", name);
dev_depends(tp->t_dev, dev);
dev->si_drv1 = tp;
/* Slave call-out devices. */
if (tp->t_flags & TF_INITLOCK) {
dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
dev_depends(tp->t_dev, dev);
dev->si_drv1 = tp;
dev->si_drv2 = &tp->t_termios_init_out;
dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
dev_depends(tp->t_dev, dev);
dev->si_drv1 = tp;
dev->si_drv2 = &tp->t_termios_lock_out;
}
}
}
/*
* Signalling processes.
*/
void
tty_signal_sessleader(struct tty *tp, int sig)
{
struct proc *p;
tty_lock_assert(tp, MA_OWNED);
MPASS(sig >= 1 && sig < NSIG);
/* Make signals start output again. */
tp->t_flags &= ~TF_STOPPED;
if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
p = tp->t_session->s_leader;
PROC_LOCK(p);
psignal(p, sig);
PROC_UNLOCK(p);
}
}
void
tty_signal_pgrp(struct tty *tp, int sig)
{
tty_lock_assert(tp, MA_OWNED);
MPASS(sig >= 1 && sig < NSIG);
/* Make signals start output again. */
tp->t_flags &= ~TF_STOPPED;
if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
tty_info(tp);
if (tp->t_pgrp != NULL) {
PGRP_LOCK(tp->t_pgrp);
pgsignal(tp->t_pgrp, sig, 1);
PGRP_UNLOCK(tp->t_pgrp);
}
}
void
tty_wakeup(struct tty *tp, int flags)
{
if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
if (flags & FWRITE) {
cv_broadcast(&tp->t_outwait);
selwakeup(&tp->t_outpoll);
KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
}
if (flags & FREAD) {
cv_broadcast(&tp->t_inwait);
selwakeup(&tp->t_inpoll);
KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
}
}
int
tty_wait(struct tty *tp, struct cv *cv)
{
int error;
int revokecnt = tp->t_revokecnt;
tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
MPASS(!tty_gone(tp));
error = cv_wait_sig(cv, tp->t_mtx);
/* Restart the system call when we may have been revoked. */
if (tp->t_revokecnt != revokecnt)
return (ERESTART);
/* Bail out when the device slipped away. */
if (tty_gone(tp))
return (ENXIO);
return (error);
}
int
tty_timedwait(struct tty *tp, struct cv *cv, int hz)
{
int error;
int revokecnt = tp->t_revokecnt;
tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
MPASS(!tty_gone(tp));
error = cv_timedwait_sig(cv, tp->t_mtx, hz);
/* Restart the system call when we may have been revoked. */
if (tp->t_revokecnt != revokecnt)
return (ERESTART);
/* Bail out when the device slipped away. */
if (tty_gone(tp))
return (ENXIO);
return (error);
}
void
tty_flush(struct tty *tp, int flags)
{
if (flags & FWRITE) {
tp->t_flags &= ~TF_HIWAT_OUT;
ttyoutq_flush(&tp->t_outq);
tty_wakeup(tp, FWRITE);
ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
}
if (flags & FREAD) {
tty_hiwat_in_unblock(tp);
ttyinq_flush(&tp->t_inq);
ttydevsw_inwakeup(tp);
ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
}
}
static int
tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
{
int error;
switch (cmd) {
/*
* Modem commands.
* The SER_* and TIOCM_* flags are the same, but one bit
* shifted. I don't know why.
*/
case TIOCSDTR:
ttydevsw_modem(tp, SER_DTR, 0);
return (0);
case TIOCCDTR:
ttydevsw_modem(tp, 0, SER_DTR);
return (0);
case TIOCMSET: {
int bits = *(int *)data;
ttydevsw_modem(tp,
(bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
return (0);
}
case TIOCMBIS: {
int bits = *(int *)data;
ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
return (0);
}
case TIOCMBIC: {
int bits = *(int *)data;
ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
return (0);
}
case TIOCMGET:
*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
return (0);
case FIOASYNC:
if (*(int *)data)
tp->t_flags |= TF_ASYNC;
else
tp->t_flags &= ~TF_ASYNC;
return (0);
case FIONBIO:
/* This device supports non-blocking operation. */
return (0);
case FIONREAD:
*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
return (0);
case FIOSETOWN:
if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
/* Not allowed to set ownership. */
return (ENOTTY);
/* Temporarily unlock the TTY to set ownership. */
tty_unlock(tp);
error = fsetown(*(int *)data, &tp->t_sigio);
tty_lock(tp);
return (error);
case FIOGETOWN:
if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
/* Not allowed to set ownership. */
return (ENOTTY);
/* Get ownership. */
*(int *)data = fgetown(&tp->t_sigio);
return (0);
case TIOCGETA:
/* Obtain terminal flags through tcgetattr(). */
bcopy(&tp->t_termios, data, sizeof(struct termios));
return (0);
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF: {
struct termios *t = data;
/*
* Who makes up these funny rules? According to POSIX,
* input baud rate is set equal to the output baud rate
* when zero.
*/
if (t->c_ispeed == 0)
t->c_ispeed = t->c_ospeed;
/* Discard any unsupported bits. */
t->c_iflag &= TTYSUP_IFLAG;
t->c_oflag &= TTYSUP_OFLAG;
t->c_lflag &= TTYSUP_LFLAG;
t->c_cflag &= TTYSUP_CFLAG;
/* Set terminal flags through tcsetattr(). */
if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
error = tty_drain(tp);
if (error)
return (error);
if (cmd == TIOCSETAF)
tty_flush(tp, FREAD);
}
/*
* Only call param() when the flags really change.
*/
if ((t->c_cflag & CIGNORE) == 0 &&
(tp->t_termios.c_cflag != t->c_cflag ||
tp->t_termios.c_ispeed != t->c_ispeed ||
tp->t_termios.c_ospeed != t->c_ospeed)) {
error = ttydevsw_param(tp, t);
if (error)
return (error);
/* XXX: CLOCAL? */
tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
tp->t_termios.c_ispeed = t->c_ispeed;
tp->t_termios.c_ospeed = t->c_ospeed;
/* Baud rate has changed - update watermarks. */
tty_watermarks(tp);
}
/* Copy new non-device driver parameters. */
tp->t_termios.c_iflag = t->c_iflag;
tp->t_termios.c_oflag = t->c_oflag;
tp->t_termios.c_lflag = t->c_lflag;
bcopy(t->c_cc, &tp->t_termios.c_cc, sizeof(t->c_cc));
ttydisc_optimize(tp);
if ((t->c_lflag & ICANON) == 0) {
/*
* When in non-canonical mode, wake up all
* readers. Canonicalize any partial input. VMIN
* and VTIME could also be adjusted.
*/
ttyinq_canonicalize(&tp->t_inq);
tty_wakeup(tp, FREAD);
}
/*
* For packet mode: notify the PTY consumer that VSTOP
* and VSTART may have been changed.
*/
if (tp->t_termios.c_iflag & IXON &&
tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
tp->t_termios.c_cc[VSTART] == CTRL('Q'))
ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
else
ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
return (0);
}
case TIOCGETD:
/* For compatibility - we only support TTYDISC. */
*(int *)data = TTYDISC;
return (0);
case TIOCGPGRP:
if (!tty_is_ctty(tp, td->td_proc))
return (ENOTTY);
if (tp->t_pgrp != NULL)
*(int *)data = tp->t_pgrp->pg_id;
else
*(int *)data = NO_PID;
return (0);
case TIOCGSID:
if (!tty_is_ctty(tp, td->td_proc))
return (ENOTTY);
MPASS(tp->t_session);
*(int *)data = tp->t_session->s_sid;
return (0);
case TIOCSCTTY: {
struct proc *p = td->td_proc;
/* XXX: This looks awful. */
tty_unlock(tp);
sx_xlock(&proctree_lock);
tty_lock(tp);
if (!SESS_LEADER(p)) {
/* Only the session leader may do this. */
sx_xunlock(&proctree_lock);
return (EPERM);
}
if (tp->t_session != NULL && tp->t_session == p->p_session) {
/* This is already our controlling TTY. */
sx_xunlock(&proctree_lock);
return (0);
}
if (!SESS_LEADER(p) || p->p_session->s_ttyvp != NULL ||
(tp->t_session != NULL && tp->t_session->s_ttyvp != NULL)) {
/*
* There is already a relation between a TTY and
* a session, or the caller is not the session
* leader.
*
* Allow the TTY to be stolen when the vnode is
* NULL, but the reference to the TTY is still
* active.
*/
sx_xunlock(&proctree_lock);
return (EPERM);
}
/* Connect the session to the TTY. */
tp->t_session = p->p_session;
tp->t_session->s_ttyp = tp;
tp->t_sessioncnt++;
sx_xunlock(&proctree_lock);
/* Assign foreground process group. */
tp->t_pgrp = p->p_pgrp;
PROC_LOCK(p);
p->p_flag |= P_CONTROLT;
PROC_UNLOCK(p);
return (0);
}
case TIOCSPGRP: {
struct pgrp *pg;
/*
* XXX: Temporarily unlock the TTY to locate the process
* group. This code would be lot nicer if we would ever
* decompose proctree_lock.
*/
tty_unlock(tp);
sx_slock(&proctree_lock);
pg = pgfind(*(int *)data);
if (pg != NULL)
PGRP_UNLOCK(pg);
if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
sx_sunlock(&proctree_lock);
tty_lock(tp);
return (EPERM);
}
tty_lock(tp);
/*
* Determine if this TTY is the controlling TTY after
* relocking the TTY.
*/
if (!tty_is_ctty(tp, td->td_proc)) {
sx_sunlock(&proctree_lock);
return (ENOTTY);
}
tp->t_pgrp = pg;
sx_sunlock(&proctree_lock);
/* Wake up the background process groups. */
cv_broadcast(&tp->t_bgwait);
return (0);
}
case TIOCFLUSH: {
int flags = *(int *)data;
if (flags == 0)
flags = (FREAD|FWRITE);
else
flags &= (FREAD|FWRITE);
tty_flush(tp, flags);
return (0);
}
case TIOCDRAIN:
/* Drain TTY output. */
return tty_drain(tp);
case TIOCCONS:
/* Set terminal as console TTY. */
if (*(int *)data) {
error = priv_check(td, PRIV_TTY_CONSOLE);
if (error)
return (error);
/*
* XXX: constty should really need to be locked!
* XXX: allow disconnected constty's to be stolen!
*/
if (constty == tp)
return (0);
if (constty != NULL)
return (EBUSY);
tty_unlock(tp);
constty_set(tp);
tty_lock(tp);
} else if (constty == tp) {
constty_clear();
}
return (0);
case TIOCGWINSZ:
/* Obtain window size. */
bcopy(&tp->t_winsize, data, sizeof(struct winsize));
return (0);
case TIOCSWINSZ:
/* Set window size. */
if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
return (0);
bcopy(data, &tp->t_winsize, sizeof(struct winsize));
tty_signal_pgrp(tp, SIGWINCH);
return (0);
case TIOCEXCL:
tp->t_flags |= TF_EXCLUDE;
return (0);
case TIOCNXCL:
tp->t_flags &= ~TF_EXCLUDE;
return (0);
case TIOCOUTQ:
*(unsigned int *)data = ttyoutq_bytesused(&tp->t_outq);
return (0);
case TIOCSTOP:
tp->t_flags |= TF_STOPPED;
ttydevsw_pktnotify(tp, TIOCPKT_STOP);
return (0);
case TIOCSTART:
tp->t_flags &= ~TF_STOPPED;
ttydevsw_outwakeup(tp);
ttydevsw_pktnotify(tp, TIOCPKT_START);
return (0);
case TIOCSTAT:
tty_info(tp);
return (0);
}
#ifdef COMPAT_43TTY
return tty_ioctl_compat(tp, cmd, data, td);
#else /* !COMPAT_43TTY */
return (ENOIOCTL);
#endif /* COMPAT_43TTY */
}
int
tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
{
int error;
tty_lock_assert(tp, MA_OWNED);
if (tty_gone(tp))
return (ENXIO);
error = ttydevsw_ioctl(tp, cmd, data, td);
if (error == ENOIOCTL)
error = tty_generic_ioctl(tp, cmd, data, td);
return (error);
}
dev_t
tty_udev(struct tty *tp)
{
if (tp->t_dev)
return dev2udev(tp->t_dev);
else
return NODEV;
}
int
tty_checkoutq(struct tty *tp)
{
/* 256 bytes should be enough to print a log message. */
return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
}
void
tty_hiwat_in_block(struct tty *tp)
{
if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
tp->t_termios.c_iflag & IXOFF &&
tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
/*
* Input flow control. Only enter the high watermark when we
* can successfully store the VSTOP character.
*/
if (ttyoutq_write_nofrag(&tp->t_outq,
&tp->t_termios.c_cc[VSTOP], 1) == 0)
tp->t_flags |= TF_HIWAT_IN;
} else {
/* No input flow control. */
tp->t_flags |= TF_HIWAT_IN;
}
}
void
tty_hiwat_in_unblock(struct tty *tp)
{
if (tp->t_flags & TF_HIWAT_IN &&
tp->t_termios.c_iflag & IXOFF &&
tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
/*
* Input flow control. Only leave the high watermark when we
* can successfully store the VSTART character.
*/
if (ttyoutq_write_nofrag(&tp->t_outq,
&tp->t_termios.c_cc[VSTART], 1) == 0)
tp->t_flags &= ~TF_HIWAT_IN;
} else {
/* No input flow control. */
tp->t_flags &= ~TF_HIWAT_IN;
}
if (!tty_gone(tp))
ttydevsw_inwakeup(tp);
}
/*
* TTY hooks interface.
*/
static int
ttyhook_defrint(struct tty *tp, char c, int flags)
{
if (ttyhook_rint_bypass(tp, &c, 1) != 1)
return (-1);
return (0);
}
int
ttyhook_register(struct tty **rtp, struct proc *p, int fd,
struct ttyhook *th, void *softc)
{
struct tty *tp;
struct file *fp;
struct cdev *dev;
struct cdevsw *cdp;
struct filedesc *fdp;
int error;
/* Validate the file descriptor. */
if ((fdp = p->p_fd) == NULL)
return (EBADF);
FILEDESC_SLOCK(fdp);
if ((fp = fget_locked(fdp, fd)) == NULL || fp->f_ops == &badfileops) {
FILEDESC_SUNLOCK(fdp);
return (EBADF);
}
/* Make sure the vnode is bound to a character device. */
error = EINVAL;
if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
fp->f_vnode->v_rdev == NULL)
goto done1;
dev = fp->f_vnode->v_rdev;
/* Make sure it is a TTY. */
cdp = dev_refthread(dev);
if (cdp == NULL)
goto done1;
if (cdp != &ttydev_cdevsw)
goto done2;
tp = dev->si_drv1;
/* Try to attach the hook to the TTY. */
error = EBUSY;
tty_lock(tp);
MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
if (tp->t_flags & TF_HOOK)
goto done3;
tp->t_flags |= TF_HOOK;
tp->t_hook = th;
tp->t_hooksoftc = softc;
*rtp = tp;
error = 0;
/* Maybe we can switch into bypass mode now. */
ttydisc_optimize(tp);
/* Silently convert rint() calls to rint_bypass() when possible. */
if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
th->th_rint = ttyhook_defrint;
done3: tty_unlock(tp);
done2: dev_relthread(dev);
done1: FILEDESC_SUNLOCK(fdp);
return (error);
}
void
ttyhook_unregister(struct tty *tp)
{
tty_lock_assert(tp, MA_OWNED);
MPASS(tp->t_flags & TF_HOOK);
/* Disconnect the hook. */
tp->t_flags &= ~TF_HOOK;
tp->t_hook = NULL;
/* Maybe we need to leave bypass mode. */
ttydisc_optimize(tp);
/* Maybe deallocate the TTY as well. */
tty_rel_free(tp);
}
/*
* /dev/console handling.
*/
static int
ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct tty *tp;
/* System has no console device. */
if (dev_console_filename == NULL)
return (ENXIO);
/* Look up corresponding TTY by device name. */
sx_slock(&tty_list_sx);
TAILQ_FOREACH(tp, &tty_list, t_list) {
if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
dev_console->si_drv1 = tp;
break;
}
}
sx_sunlock(&tty_list_sx);
/* System console has no TTY associated. */
if (dev_console->si_drv1 == NULL)
return (ENXIO);
return (ttydev_open(dev, oflags, devtype, td));
}
static int
ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
{
log_console(uio);
return (ttydev_write(dev, uio, ioflag));
}
/*
* /dev/console is a little different than normal TTY's. When opened,
* it determines which TTY to use. When data gets written to it, it
* will be logged in the kernel message buffer.
*/
static struct cdevsw ttyconsdev_cdevsw = {
.d_version = D_VERSION,
.d_open = ttyconsdev_open,
.d_close = ttydev_close,
.d_read = ttydev_read,
.d_write = ttyconsdev_write,
.d_ioctl = ttydev_ioctl,
.d_kqfilter = ttydev_kqfilter,
.d_poll = ttydev_poll,
.d_mmap = ttydev_mmap,
.d_name = "ttyconsdev",
.d_flags = D_TTY,
};
static void
ttyconsdev_init(void *unused)
{
dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
0600, "console");
}
SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
void
ttyconsdev_select(const char *name)
{
dev_console_filename = name;
}
/*
* Debugging routines.
*/
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
static struct {
int flag;
char val;
} ttystates[] = {
#if 0
{ TF_NOPREFIX, 'N' },
#endif
{ TF_INITLOCK, 'I' },
{ TF_CALLOUT, 'C' },
/* Keep these together -> 'Oi' and 'Oo'. */
{ TF_OPENED, 'O' },
{ TF_OPENED_IN, 'i' },
{ TF_OPENED_OUT, 'o' },
{ TF_OPENED_CONS, 'c' },
{ TF_GONE, 'G' },
{ TF_OPENCLOSE, 'B' },
{ TF_ASYNC, 'Y' },
{ TF_LITERAL, 'L' },
/* Keep these together -> 'Hi' and 'Ho'. */
{ TF_HIWAT, 'H' },
{ TF_HIWAT_IN, 'i' },
{ TF_HIWAT_OUT, 'o' },
{ TF_STOPPED, 'S' },
{ TF_EXCLUDE, 'X' },
{ TF_BYPASS, 'l' },
{ TF_ZOMBIE, 'Z' },
{ TF_HOOK, 's' },
/* Keep these together -> 'bi' and 'bo'. */
{ TF_BUSY, 'b' },
{ TF_BUSY_IN, 'i' },
{ TF_BUSY_OUT, 'o' },
{ 0, '\0'},
};
#define TTY_FLAG_BITS \
"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
#define DB_PRINTSYM(name, addr) \
db_printf("%s " #name ": ", sep); \
db_printsym((db_addr_t) addr, DB_STGY_ANY); \
db_printf("\n");
static void
_db_show_devsw(const char *sep, const struct ttydevsw *tsw)
{
db_printf("%sdevsw: ", sep);
db_printsym((db_addr_t)tsw, DB_STGY_ANY);
db_printf(" (%p)\n", tsw);
DB_PRINTSYM(open, tsw->tsw_open);
DB_PRINTSYM(close, tsw->tsw_close);
DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
DB_PRINTSYM(param, tsw->tsw_param);
DB_PRINTSYM(modem, tsw->tsw_modem);
DB_PRINTSYM(mmap, tsw->tsw_mmap);
DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
DB_PRINTSYM(free, tsw->tsw_free);
}
static void
_db_show_hooks(const char *sep, const struct ttyhook *th)
{
db_printf("%shook: ", sep);
db_printsym((db_addr_t)th, DB_STGY_ANY);
db_printf(" (%p)\n", th);
if (th == NULL)
return;
DB_PRINTSYM(rint, th->th_rint);
DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
DB_PRINTSYM(rint_done, th->th_rint_done);
DB_PRINTSYM(rint_poll, th->th_rint_poll);
DB_PRINTSYM(getc_inject, th->th_getc_inject);
DB_PRINTSYM(getc_capture, th->th_getc_capture);
DB_PRINTSYM(getc_poll, th->th_getc_poll);
DB_PRINTSYM(close, th->th_close);
}
static void
_db_show_termios(const char *name, const struct termios *t)
{
db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
"lflag 0x%x ispeed %u ospeed %u\n", name,
t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
t->c_ispeed, t->c_ospeed);
}
/* DDB command to show TTY statistics. */
DB_SHOW_COMMAND(tty, db_show_tty)
{
struct tty *tp;
if (!have_addr) {
db_printf("usage: show tty <addr>\n");
return;
}
tp = (struct tty *)addr;
db_printf("0x%p: %s\n", tp, tty_devname(tp));
db_printf("\tmtx: %p\n", tp->t_mtx);
db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
/* Buffering mechanisms. */
db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
"nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
&tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
tp->t_outq.to_nblocks, tp->t_outq.to_quota);
db_printf("\tinlow: %zu\n", tp->t_inlow);
db_printf("\toutlow: %zu\n", tp->t_outlow);
_db_show_termios("\ttermios", &tp->t_termios);
db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
tp->t_winsize.ws_row, tp->t_winsize.ws_col,
tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
db_printf("\tcolumn: %u\n", tp->t_column);
db_printf("\twritepos: %u\n", tp->t_writepos);
db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
/* Init/lock-state devices. */
_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
/* Hooks */
_db_show_devsw("\t", tp->t_devsw);
_db_show_hooks("\t", tp->t_hook);
/* Process info. */
db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
db_printf("\tsession: %p", tp->t_session);
if (tp->t_session != NULL)
db_printf(" count %u leader %p tty %p sid %d login %s",
tp->t_session->s_count, tp->t_session->s_leader,
tp->t_session->s_ttyp, tp->t_session->s_sid,
tp->t_session->s_login);
db_printf("\n");
db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
db_printf("\tdev: %p\n", tp->t_dev);
}
/* DDB command to list TTYs. */
DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
{
struct tty *tp;
size_t isiz, osiz;
int i, j;
/* Make the output look like `pstat -t'. */
db_printf("PTR ");
#if defined(__LP64__)
db_printf(" ");
#endif
db_printf(" LINE INQ CAN LIN LOW OUTQ USE LOW "
"COL SESS PGID STATE\n");
TAILQ_FOREACH(tp, &tty_list, t_list) {
isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
tp,
tty_devname(tp),
isiz,
tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
tp->t_inq.ti_end - tp->t_inq.ti_linestart,
isiz - tp->t_inlow,
osiz,
tp->t_outq.to_end - tp->t_outq.to_begin,
osiz - tp->t_outlow,
MIN(tp->t_column, 99999),
tp->t_session ? tp->t_session->s_sid : 0,
tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
/* Flag bits. */
for (i = j = 0; ttystates[i].flag; i++)
if (tp->t_flags & ttystates[i].flag) {
db_printf("%c", ttystates[i].val);
j++;
}
if (j == 0)
db_printf("-");
db_printf("\n");
}
}
#endif /* DDB */
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