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freebsd-dev/sys/kern/tty.c
Konstantin Belousov 8cf912b017 ttydev_write: prevent stops while terminal is busied 
Since busy state is checked by all blocked writes, stopping a process
which waits in ttydisc_write() causes cascade.  Utilize sigdeferstop()
to avoid the issue.

Submitted by:	Jakub Piecuch <j.piecuch96@gmail.com>
PR:	255816
MFC after:	1 week
2021-05-18 20:52:03 +03:00

2457 lines
55 KiB
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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_capsicum.h"
#include "opt_printf.h"
#include <sys/param.h>
#include <sys/capsicum.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 <fs/devfs/devfs.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|CNO_RTSDTR)
#define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
static int tty_drainwait = 5 * 60;
SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
&tty_drainwait, 0, "Default output drain timeout in seconds");
/*
* Set TTY buffer sizes.
*/
#define TTYBUF_MAX 65536
#ifdef PRINTF_BUFR_SIZE
#define TTY_PRBUF_SIZE PRINTF_BUFR_SIZE
#else
#define TTY_PRBUF_SIZE 256
#endif
/*
* Allocate buffer space if necessary, and set low watermarks, based on speed.
* Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
* lock during memory allocation. They will return ENXIO if the tty disappears
* while unlocked.
*/
static int
tty_watermarks(struct tty *tp)
{
size_t bs = 0;
int error;
/* Provide an input buffer for 2 seconds of data. */
if (tp->t_termios.c_cflag & CREAD)
bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
error = ttyinq_setsize(&tp->t_inq, tp, bs);
if (error != 0)
return (error);
/* Set low watermark at 10% (when 90% is available). */
tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
/* Provide an output buffer for 2 seconds of data. */
bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
error = ttyoutq_setsize(&tp->t_outq, tp, bs);
if (error != 0)
return (error);
/* Set low watermark at 10% (when 90% is available). */
tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
return (0);
}
static int
tty_drain(struct tty *tp, int leaving)
{
sbintime_t timeout_at;
size_t bytes;
int error;
if (ttyhook_hashook(tp, getc_inject))
/* buffer is inaccessible */
return (0);
/*
* For close(), use the recent historic timeout of "1 second without
* making progress". For tcdrain(), use t_drainwait as the timeout,
* with zero meaning "no timeout" which gives POSIX behavior.
*/
if (leaving)
timeout_at = getsbinuptime() + SBT_1S;
else if (tp->t_drainwait != 0)
timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
else
timeout_at = 0;
/*
* Poll the output buffer and the hardware for completion, at 10 Hz.
* Polling is required for devices which are not able to signal an
* interrupt when the transmitter becomes idle (most USB serial devs).
* The unusual structure of this loop ensures we check for busy one more
* time after tty_timedwait() returns EWOULDBLOCK, so that success has
* higher priority than timeout if the IO completed in the last 100mS.
*/
error = 0;
bytes = ttyoutq_bytesused(&tp->t_outq);
for (;;) {
if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
return (0);
if (error != 0)
return (error);
ttydevsw_outwakeup(tp);
error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
if (error != 0 && error != EWOULDBLOCK)
return (error);
else if (timeout_at == 0 || getsbinuptime() < timeout_at)
error = 0;
else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
/* In close, making progress, grant an extra second. */
error = 0;
timeout_at += SBT_1S;
bytes = ttyoutq_bytesused(&tp->t_outq);
}
}
}
/*
* 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_assert_locked(tp);
if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
/* Device is still opened somewhere. */
tty_unlock(tp);
return;
}
tp->t_flags |= TF_OPENCLOSE;
/* Remove console TTY. */
if (constty == tp)
constty_clear();
/* Drain any output. */
if (!tty_gone(tp))
tty_drain(tp, 1);
ttydisc_close(tp);
/* Free i/o queues now since they might be large. */
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;
cv_broadcast(&tp->t_dcdwait);
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 __unused,
struct thread *td)
{
struct tty *tp;
int error;
tp = dev->si_drv1;
error = 0;
tty_lock(tp);
if (tty_gone(tp)) {
/* Device is already gone. */
tty_unlock(tp);
return (ENXIO);
}
/*
* Block when other processes are currently opening or closing
* the TTY.
*/
while (tp->t_flags & TF_OPENCLOSE) {
error = tty_wait(tp, &tp->t_dcdwait);
if (error != 0) {
tty_unlock(tp);
return (error);
}
}
tp->t_flags |= TF_OPENCLOSE;
/*
* Make sure the "tty" and "cua" device cannot be opened at the
* same time. The console is a "tty" device.
*/
if (TTY_CALLOUT(tp, dev)) {
if (tp->t_flags & (TF_OPENED_CONS | 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);
/* Prevent modem control on callout devices and /dev/console. */
if (TTY_CALLOUT(tp, dev) || dev == dev_console)
tp->t_termios.c_cflag |= CLOCAL;
if ((tp->t_termios.c_cflag & CNO_RTSDTR) == 0)
ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
error = ttydevsw_open(tp);
if (error != 0)
goto done;
ttydisc_open(tp);
error = tty_watermarks(tp);
if (error != 0)
goto done;
}
/* Wait for Carrier Detect. */
if ((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;
MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
(tp->t_flags & TF_OPENED_OUT) == 0);
done: tp->t_flags &= ~TF_OPENCLOSE;
cv_broadcast(&tp->t_dcdwait);
ttydev_leave(tp);
return (error);
}
static int
ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
struct thread *td __unused)
{
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_CONS | TF_OPENED_IN)) == 0 ||
(tp->t_flags & TF_OPENED_OUT) == 0);
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);
}
/* If revoking, flush output now to avoid draining it later. */
if (fflag & FREVOKE)
tty_flush(tp, FWRITE);
tp->t_flags &= ~TF_EXCLUDE;
/* Properly wake up threads that are stuck - revoke(). */
tp->t_revokecnt++;
tty_wakeup(tp, FREAD|FWRITE);
cv_broadcast(&tp->t_bgwait);
cv_broadcast(&tp->t_dcdwait);
ttydev_leave(tp);
return (0);
}
static __inline int
tty_is_ctty(struct tty *tp, struct proc *p)
{
tty_assert_locked(tp);
return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
}
int
tty_wait_background(struct tty *tp, struct thread *td, int sig)
{
struct proc *p;
struct pgrp *pg;
ksiginfo_t ksi;
int error;
MPASS(sig == SIGTTIN || sig == SIGTTOU);
tty_assert_locked(tp);
p = td->td_proc;
for (;;) {
pg = p->p_pgrp;
PGRP_LOCK(pg);
PROC_LOCK(p);
/*
* pg may no longer be our process group.
* Re-check after locking.
*/
if (p->p_pgrp != pg) {
PROC_UNLOCK(p);
PGRP_UNLOCK(pg);
continue;
}
/*
* The process should only sleep, when:
* - This terminal is the controlling 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) {
/* Allow the action to happen. */
PROC_UNLOCK(p);
PGRP_UNLOCK(pg);
return (0);
}
if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
SIGISMEMBER(td->td_sigmask, sig)) {
/* Only allow them in write()/ioctl(). */
PROC_UNLOCK(p);
PGRP_UNLOCK(pg);
return (sig == SIGTTOU ? 0 : EIO);
}
if ((p->p_flag & P_PPWAIT) != 0 ||
(pg->pg_flags & PGRP_ORPHANED) != 0) {
/* Don't allow the action to happen. */
PROC_UNLOCK(p);
PGRP_UNLOCK(pg);
return (EIO);
}
PROC_UNLOCK(p);
/*
* Send the signal and sleep until we're the new
* foreground process group.
*/
if (sig != 0) {
ksiginfo_init(&ksi);
ksi.ksi_code = SI_KERNEL;
ksi.ksi_signo = sig;
sig = 0;
}
pgsignal(pg, ksi.ksi_signo, 1, &ksi);
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 = 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 defer, 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_outserwait);
if (error)
goto done;
}
tp->t_flags |= TF_BUSY_OUT;
defer = sigdeferstop(SIGDEFERSTOP_ERESTART);
error = ttydisc_write(tp, uio, ioflag);
sigallowstop(defer);
tp->t_flags &= ~TF_BUSY_OUT;
cv_signal(&tp->t_outserwait);
}
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 TIOCSTI:
case TIOCSTOP:
case TIOCSWINSZ:
#if 0
case TIOCSDRAINWAIT:
case TIOCSETD:
#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;
}
if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
struct termios *old = &tp->t_termios;
struct termios *new = (struct termios *)data;
struct termios *lock = TTY_CALLOUT(tp, dev) ?
&tp->t_termios_lock_out : &tp->t_termios_lock_in;
int cc;
/*
* Lock state devices. Just overwrite the values of the
* commands that are currently in use.
*/
new->c_iflag = (old->c_iflag & lock->c_iflag) |
(new->c_iflag & ~lock->c_iflag);
new->c_oflag = (old->c_oflag & lock->c_oflag) |
(new->c_oflag & ~lock->c_oflag);
new->c_cflag = (old->c_cflag & lock->c_cflag) |
(new->c_cflag & ~lock->c_cflag);
new->c_lflag = (old->c_lflag & lock->c_lflag) |
(new->c_lflag & ~lock->c_lflag);
for (cc = 0; cc < NCCS; ++cc)
if (lock->c_cc[cc])
new->c_cc[cc] = old->c_cc[cc];
if (lock->c_ispeed)
new->c_ispeed = old->c_ispeed;
if (lock->c_ospeed)
new->c_ospeed = old->c_ospeed;
}
error = tty_ioctl(tp, cmd, data, fflag, 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)
return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
if (events & (POLLIN|POLLRDNORM)) {
/* See if we can read something. */
if (ttydisc_read_poll(tp) > 0)
revents |= events & (POLLIN|POLLRDNORM);
}
if (tp->t_flags & TF_ZOMBIE) {
/* Hangup flag on zombie state. */
revents |= POLLHUP;
} else if (events & (POLLOUT|POLLWRNORM)) {
/* See if we can write something. */
if (ttydisc_write_poll(tp) > 0)
revents |= events & (POLLOUT|POLLWRNORM);
}
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_ooffset_t offset, vm_paddr_t *paddr,
int nprot, vm_memattr_t *memattr)
{
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, memattr);
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 __unused)
{
struct tty *tp = kn->kn_hook;
tty_assert_locked(tp);
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 __unused)
{
struct tty *tp = kn->kn_hook;
tty_assert_locked(tp);
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 = {
.f_isfd = 1,
.f_detach = tty_kqops_read_detach,
.f_event = tty_kqops_read_event,
};
static struct filterops tty_kqops_write = {
.f_isfd = 1,
.f_detach = tty_kqops_write_detach,
.f_event = 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 __unused, int devtype __unused,
struct thread *td)
{
struct tty *tp;
int error;
tp = dev->si_drv1;
error = 0;
tty_lock(tp);
if (tty_gone(tp))
error = ENODEV;
tty_unlock(tp);
return (error);
}
static int
ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
struct thread *td __unused)
{
return (0);
}
static int
ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
int ioflag __unused)
{
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;
tty_lock(tp);
if (tty_gone(tp)) {
error = ENODEV;
goto done;
}
error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
if (error != ENOIOCTL)
goto done;
error = 0;
switch (cmd) {
case TIOCGETA:
/* Obtain terminal flags through tcgetattr(). */
*(struct termios*)data = *(struct termios*)dev->si_drv2;
break;
case TIOCSETA:
/* Set terminal flags through tcsetattr(). */
error = priv_check(td, PRIV_TTY_SETA);
if (error)
break;
*(struct termios*)dev->si_drv2 = *(struct termios*)data;
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;
memcpy(&t->c_cc, ttydefchars, 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 __unused)
{
return (0);
}
static void
ttydevsw_defclose(struct tty *tp __unused)
{
}
static void
ttydevsw_defoutwakeup(struct tty *tp __unused)
{
panic("Terminal device has output, while not implemented");
}
static void
ttydevsw_definwakeup(struct tty *tp __unused)
{
}
static int
ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
caddr_t data __unused, struct thread *td __unused)
{
return (ENOIOCTL);
}
static int
ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
{
return (ENOIOCTL);
}
static int
ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
{
/*
* Allow the baud rate to be adjusted for pseudo-devices, but at
* least restrict it to 115200 to prevent excessive buffer
* usage. Also disallow 0, to prevent foot shooting.
*/
if (t->c_ispeed < B50)
t->c_ispeed = B50;
else if (t->c_ispeed > B115200)
t->c_ispeed = B115200;
if (t->c_ospeed < B50)
t->c_ospeed = B50;
else if (t->c_ospeed > B115200)
t->c_ospeed = B115200;
t->c_cflag |= CREAD;
return (0);
}
static int
ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
int sigoff __unused)
{
/* Simulate a carrier to make the TTY layer happy. */
return (SER_DCD);
}
static int
ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
vm_paddr_t *paddr __unused, int nprot __unused,
vm_memattr_t *memattr __unused)
{
return (-1);
}
static void
ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
{
}
static void
ttydevsw_deffree(void *softc __unused)
{
panic("Terminal device freed without a free-handler");
}
static bool
ttydevsw_defbusy(struct tty *tp __unused)
{
return (FALSE);
}
/*
* 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)
{
return (tty_alloc_mutex(tsw, sc, NULL));
}
struct tty *
tty_alloc_mutex(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(cioctl);
PATCH_FUNC(param);
PATCH_FUNC(modem);
PATCH_FUNC(mmap);
PATCH_FUNC(pktnotify);
PATCH_FUNC(free);
PATCH_FUNC(busy);
#undef PATCH_FUNC
tp = malloc(sizeof(struct tty) + TTY_PRBUF_SIZE, M_TTY,
M_WAITOK | M_ZERO);
tp->t_prbufsz = TTY_PRBUF_SIZE;
tp->t_devsw = tsw;
tp->t_devswsoftc = sc;
tp->t_flags = tsw->tsw_flags;
tp->t_drainwait = tty_drainwait;
tty_init_termios(tp);
cv_init(&tp->t_inwait, "ttyin");
cv_init(&tp->t_outwait, "ttyout");
cv_init(&tp->t_outserwait, "ttyosr");
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_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
return (tp);
}
static void
tty_dealloc(void *arg)
{
struct tty *tp = arg;
/*
* ttyydev_leave() usually frees the i/o queues earlier, but it is
* not always called between queue allocation and here. The queues
* may be allocated by ioctls on a pty control device without the
* corresponding pty slave device ever being open, or after it is
* closed.
*/
ttyinq_free(&tp->t_inq);
ttyoutq_free(&tp->t_outq);
seldrain(&tp->t_inpoll);
seldrain(&tp->t_outpoll);
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);
cv_destroy(&tp->t_outserwait);
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_assert_locked(tp);
#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;
}
/* Stop asynchronous I/O. */
funsetown(&tp->t_sigio);
/* TTY can be deallocated. */
dev = tp->t_dev;
tp->t_dev = NULL;
tty_unlock(tp);
if (dev != NULL) {
sx_xlock(&tty_list_sx);
TAILQ_REMOVE(&tty_list, tp, t_list);
tty_list_count--;
sx_xunlock(&tty_list_sx);
destroy_dev_sched_cb(dev, tty_dealloc, tp);
}
}
void
tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
{
MPASS(tp->t_sessioncnt > 0);
tty_assert_locked(tp);
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)
{
tty_assert_locked(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);
}
static int
tty_drop_ctty(struct tty *tp, struct proc *p)
{
struct session *session;
struct vnode *vp;
/*
* This looks terrible, but it's generally safe as long as the tty
* hasn't gone away while we had the lock dropped. All of our sanity
* checking that this operation is OK happens after we've picked it back
* up, so other state changes are generally not fatal and the potential
* for this particular operation to happen out-of-order in a
* multithreaded scenario is likely a non-issue.
*/
tty_unlock(tp);
sx_xlock(&proctree_lock);
tty_lock(tp);
if (tty_gone(tp)) {
sx_xunlock(&proctree_lock);
return (ENODEV);
}
/*
* If the session doesn't have a controlling TTY, or if we weren't
* invoked on the controlling TTY, we'll return ENOIOCTL as we've
* historically done.
*/
session = p->p_session;
if (session->s_ttyp == NULL || session->s_ttyp != tp) {
sx_xunlock(&proctree_lock);
return (ENOTTY);
}
if (!SESS_LEADER(p)) {
sx_xunlock(&proctree_lock);
return (EPERM);
}
PROC_LOCK(p);
SESS_LOCK(session);
vp = session->s_ttyvp;
session->s_ttyp = NULL;
session->s_ttyvp = NULL;
session->s_ttydp = NULL;
SESS_UNLOCK(session);
tp->t_sessioncnt--;
p->p_flag &= ~P_CONTROLT;
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
/*
* If we did have a vnode, release our reference. Ordinarily we manage
* these at the devfs layer, but we can't necessarily know that we were
* invoked on the vnode referenced in the session (i.e. the vnode we
* hold a reference to). We explicitly don't check VBAD/VIRF_DOOMED here
* to avoid a vnode leak -- in circumstances elsewhere where we'd hit a
* VIRF_DOOMED vnode, release has been deferred until the controlling TTY
* is either changed or released.
*/
if (vp != NULL)
devfs_ctty_unref(vp);
return (0);
}
/*
* Exposing information about current TTY's through sysctl
*/
static void
tty_to_xtty(struct tty *tp, struct xtty *xt)
{
tty_assert_locked(tp);
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) : (uint32_t)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_TTY, 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_TTY);
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.
*/
int
tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
const char *fmt, ...)
{
va_list ap;
struct make_dev_args args;
struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
const char *prefix = "tty";
char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
uid_t uid;
gid_t gid;
mode_t mode;
int error;
/* 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;
}
flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
flags |= MAKEDEV_CHECKNAME;
/* Master call-in device. */
make_dev_args_init(&args);
args.mda_flags = flags;
args.mda_devsw = &ttydev_cdevsw;
args.mda_cr = cred;
args.mda_uid = uid;
args.mda_gid = gid;
args.mda_mode = mode;
args.mda_si_drv1 = tp;
error = make_dev_s(&args, &dev, "%s%s", prefix, name);
if (error != 0)
return (error);
tp->t_dev = dev;
init = lock = cua = cinit = clock = NULL;
/* Slave call-in devices. */
if (tp->t_flags & TF_INITLOCK) {
args.mda_devsw = &ttyil_cdevsw;
args.mda_unit = TTYUNIT_INIT;
args.mda_si_drv1 = tp;
args.mda_si_drv2 = &tp->t_termios_init_in;
error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
if (error != 0)
goto fail;
dev_depends(dev, init);
args.mda_unit = TTYUNIT_LOCK;
args.mda_si_drv2 = &tp->t_termios_lock_in;
error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
if (error != 0)
goto fail;
dev_depends(dev, lock);
}
/* Call-out devices. */
if (tp->t_flags & TF_CALLOUT) {
make_dev_args_init(&args);
args.mda_flags = flags;
args.mda_devsw = &ttydev_cdevsw;
args.mda_cr = cred;
args.mda_uid = UID_UUCP;
args.mda_gid = GID_DIALER;
args.mda_mode = 0660;
args.mda_unit = TTYUNIT_CALLOUT;
args.mda_si_drv1 = tp;
error = make_dev_s(&args, &cua, "cua%s", name);
if (error != 0)
goto fail;
dev_depends(dev, cua);
/* Slave call-out devices. */
if (tp->t_flags & TF_INITLOCK) {
args.mda_devsw = &ttyil_cdevsw;
args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
args.mda_si_drv2 = &tp->t_termios_init_out;
error = make_dev_s(&args, &cinit, "cua%s.init", name);
if (error != 0)
goto fail;
dev_depends(dev, cinit);
args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
args.mda_si_drv2 = &tp->t_termios_lock_out;
error = make_dev_s(&args, &clock, "cua%s.lock", name);
if (error != 0)
goto fail;
dev_depends(dev, clock);
}
}
sx_xlock(&tty_list_sx);
TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
tty_list_count++;
sx_xunlock(&tty_list_sx);
return (0);
fail:
destroy_dev(dev);
if (init)
destroy_dev(init);
if (lock)
destroy_dev(lock);
if (cinit)
destroy_dev(cinit);
if (clock)
destroy_dev(clock);
return (error);
}
/*
* Signalling processes.
*/
void
tty_signal_sessleader(struct tty *tp, int sig)
{
struct proc *p;
struct session *s;
tty_assert_locked(tp);
MPASS(sig >= 1 && sig < NSIG);
/* Make signals start output again. */
tp->t_flags &= ~TF_STOPPED;
tp->t_termios.c_lflag &= ~FLUSHO;
/*
* Load s_leader exactly once to avoid race where s_leader is
* set to NULL by a concurrent invocation of killjobc() by the
* session leader. Note that we are not holding t_session's
* lock for the read.
*/
if ((s = tp->t_session) != NULL &&
(p = atomic_load_ptr(&s->s_leader)) != NULL) {
PROC_LOCK(p);
kern_psignal(p, sig);
PROC_UNLOCK(p);
}
}
void
tty_signal_pgrp(struct tty *tp, int sig)
{
ksiginfo_t ksi;
tty_assert_locked(tp);
MPASS(sig >= 1 && sig < NSIG);
/* Make signals start output again. */
tp->t_flags &= ~TF_STOPPED;
tp->t_termios.c_lflag &= ~FLUSHO;
if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
tty_info(tp);
if (tp->t_pgrp != NULL) {
ksiginfo_init(&ksi);
ksi.ksi_signo = sig;
ksi.ksi_code = SI_KERNEL;
PGRP_LOCK(tp->t_pgrp);
pgsignal(tp->t_pgrp, sig, 1, &ksi);
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);
/* Bail out when the device slipped away. */
if (tty_gone(tp))
return (ENXIO);
/* Restart the system call when we may have been revoked. */
if (tp->t_revokecnt != revokecnt)
return (ERESTART);
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);
/* Bail out when the device slipped away. */
if (tty_gone(tp))
return (ENXIO);
/* Restart the system call when we may have been revoked. */
if (tp->t_revokecnt != revokecnt)
return (ERESTART);
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);
if (!tty_gone(tp)) {
ttydevsw_outwakeup(tp);
ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
}
}
if (flags & FREAD) {
tty_hiwat_in_unblock(tp);
ttyinq_flush(&tp->t_inq);
tty_wakeup(tp, FREAD);
if (!tty_gone(tp)) {
ttydevsw_inwakeup(tp);
ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
}
}
}
void
tty_set_winsize(struct tty *tp, const struct winsize *wsz)
{
if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
return;
tp->t_winsize = *wsz;
tty_signal_pgrp(tp, SIGWINCH);
}
static int
tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
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 FIONWRITE:
case TIOCOUTQ:
*(int *)data = ttyoutq_bytesused(&tp->t_outq);
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(). */
*(struct termios*)data = tp->t_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, 0);
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_iflag ^ t->c_iflag) &
(IXON|IXOFF|IXANY)) ||
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. */
error = tty_watermarks(tp);
if (error)
return (error);
}
/* 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;
memcpy(&tp->t_termios.c_cc, t->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 TIOCNOTTY:
return (tty_drop_ctty(tp, td->td_proc));
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 (p->p_session->s_ttyp != NULL ||
(tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
tp->t_session->s_ttyvp->v_type != VBAD)) {
/*
* 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
* invalid, but the reference to the TTY is
* still active. This allows immediate reuse of
* TTYs of which the session leader has been
* killed or the TTY revoked.
*/
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++;
/* Assign foreground process group. */
tp->t_pgrp = p->p_pgrp;
PROC_LOCK(p);
p->p_flag |= P_CONTROLT;
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
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, 0);
case TIOCGDRAINWAIT:
*(int *)data = tp->t_drainwait;
return (0);
case TIOCSDRAINWAIT:
error = priv_check(td, PRIV_TTY_DRAINWAIT);
if (error == 0)
tp->t_drainwait = *(int *)data;
return (error);
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. */
*(struct winsize*)data = tp->t_winsize;
return (0);
case TIOCSWINSZ:
/* Set window size. */
tty_set_winsize(tp, data);
return (0);
case TIOCEXCL:
tp->t_flags |= TF_EXCLUDE;
return (0);
case TIOCNXCL:
tp->t_flags &= ~TF_EXCLUDE;
return (0);
case TIOCSTOP:
tp->t_flags |= TF_STOPPED;
ttydevsw_pktnotify(tp, TIOCPKT_STOP);
return (0);
case TIOCSTART:
tp->t_flags &= ~TF_STOPPED;
tp->t_termios.c_lflag &= ~FLUSHO;
ttydevsw_outwakeup(tp);
ttydevsw_pktnotify(tp, TIOCPKT_START);
return (0);
case TIOCSTAT:
tty_info(tp);
return (0);
case TIOCSTI:
if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
return (EPERM);
if (!tty_is_ctty(tp, td->td_proc) &&
priv_check(td, PRIV_TTY_STI))
return (EACCES);
ttydisc_rint(tp, *(char *)data, 0);
ttydisc_rint_done(tp);
return (0);
}
#ifdef COMPAT_43TTY
return tty_ioctl_compat(tp, cmd, data, fflag, td);
#else /* !COMPAT_43TTY */
return (ENOIOCTL);
#endif /* COMPAT_43TTY */
}
int
tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
{
int error;
tty_assert_locked(tp);
if (tty_gone(tp))
return (ENXIO);
error = ttydevsw_ioctl(tp, cmd, data, td);
if (error == ENOIOCTL)
error = tty_generic_ioctl(tp, cmd, data, fflag, 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;
cap_rights_t rights;
int error, ref;
/* Validate the file descriptor. */
fdp = p->p_fd;
error = fget_unlocked(fdp, fd, cap_rights_init_one(&rights, CAP_TTYHOOK),
&fp);
if (error != 0)
return (error);
if (fp->f_ops == &badfileops) {
error = EBADF;
goto done1;
}
/*
* Make sure the vnode is bound to a character device.
* Unlocked check for the vnode type is ok there, because we
* only shall prevent calling devvn_refthread on the file that
* never has been opened over a character device.
*/
if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
error = EINVAL;
goto done1;
}
/* Make sure it is a TTY. */
cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
if (cdp == NULL) {
error = ENXIO;
goto done1;
}
if (dev != fp->f_data) {
error = ENXIO;
goto done2;
}
if (cdp != &ttydev_cdevsw) {
error = ENOTTY;
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, ref);
done1: fdrop(fp, curthread);
return (error);
}
void
ttyhook_unregister(struct tty *tp)
{
tty_assert_locked(tp);
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 __unused)
{
dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
NULL, 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 const 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\6OPENED_CONS\7GONE\10OPENCLOSE" \
"\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
"\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
"\21HOOK\22BUSY_IN\23BUSY_OUT"
#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("%p: %s\n", tp, tty_devname(tp));
db_printf("\tmtx: %p\n", tp->t_mtx);
db_printf("\tflags: 0x%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\n", tp->t_pgrp,
tp->t_pgrp ? tp->t_pgrp->pg_id : 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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