/* $NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $ */

/* $NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $ */

/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tty_pty.c 8.4 (Berkeley) 2/20/95
*/

/*
* Pseudo-teletype Driver
* (Actually two drivers, requiring two entries in 'cdevsw')
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $");

#include "opt_ptm.h"

#define TTY_ALLOW_PRIVATE

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/ioctl_compat.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/filedesc.h>
#include <sys/conf.h>
#include <sys/poll.h>
#include <sys/pty.h>
#include <sys/kauth.h>

#include "ioconf.h"

#define DEFAULT_NPTYS 16 /* default number of initial ptys */
#define DEFAULT_MAXPTYS 992 /* default maximum number of ptys */

#define BUFSIZ 100 /* Chunk size iomoved to/from user */

struct pt_softc {
struct tty *pt_tty;
int pt_flags;
struct selinfo pt_selr, pt_selw;
u_char pt_send;
u_char pt_ucntl;
};

static struct pt_softc **pt_softc = NULL; /* pty array */
static int maxptys = DEFAULT_MAXPTYS; /* maximum number of ptys (sysctable) */
kmutex_t pt_softc_mutex;
int npty = 0; /* for pstat -t */

#define PF_PKT 0x08 /* packet mode */
#define PF_STOPPED 0x10 /* user told stopped */
#define PF_REMOTE 0x20 /* remote and flow controlled input */
#define PF_NOSTOP 0x40
#define PF_UCNTL 0x80 /* user control mode */

void ptcwakeup(struct tty *, int);
void ptsstart(struct tty *);
int pty_maxptys(int, int);

static struct pt_softc **ptyarralloc(int);

dev_type_open(ptcopen);
dev_type_close(ptcclose);
dev_type_read(ptcread);
dev_type_write(ptcwrite);
dev_type_poll(ptcpoll);
dev_type_kqfilter(ptckqfilter);

dev_type_open(ptsopen);
dev_type_close(ptsclose);
dev_type_read(ptsread);
dev_type_write(ptswrite);
dev_type_stop(ptsstop);
dev_type_poll(ptspoll);

dev_type_ioctl(ptyioctl);
dev_type_tty(ptytty);

const struct cdevsw ptc_cdevsw = {
.d_open = ptcopen,
.d_close = ptcclose,
.d_read = ptcread,
.d_write = ptcwrite,
.d_ioctl = ptyioctl,
.d_stop = nullstop,
.d_tty = ptytty,
.d_poll = ptcpoll,
.d_mmap = nommap,
.d_kqfilter = ptckqfilter,
.d_discard = nodiscard,
.d_flag = D_TTY
};

const struct cdevsw pts_cdevsw = {
.d_open = ptsopen,
.d_close = ptsclose,
.d_read = ptsread,
.d_write = ptswrite,
.d_ioctl = ptyioctl,
.d_stop = ptsstop,
.d_tty = ptytty,
.d_poll = ptspoll,
.d_mmap = nommap,
.d_kqfilter = ttykqfilter,
.d_discard = nodiscard,
.d_flag = D_TTY
};

#if defined(pmax)
/*
* Used by arch/pmax/conf/majors.pmax, which needs a second copy as it
* needs to map this stuff to two pairs of majors.
*/

const struct cdevsw ptc_ultrix_cdevsw = {
.d_open = ptcopen,
.d_close = ptcclose,
.d_read = ptcread,
.d_write = ptcwrite,
.d_ioctl = ptyioctl,
.d_stop = nullstop,
.d_tty = ptytty,
.d_poll = ptcpoll,
.d_mmap = nommap,
.d_kqfilter = ptckqfilter,
.d_discard = nodiscard,
.d_flag = D_TTY
};

const struct cdevsw pts_ultrix_cdevsw = {
.d_open = ptsopen,
.d_close = ptsclose,
.d_read = ptsread,
.d_write = ptswrite,
.d_ioctl = ptyioctl,
.d_stop = ptsstop,
.d_tty = ptytty,
.d_poll = ptspoll,
.d_mmap = nommap,
.d_kqfilter = ttykqfilter,
.d_discard = nodiscard,
.d_flag = D_TTY
};
#endif /* defined(pmax) */

/*
* Check if a pty is free to use.
*/
int
pty_isfree(int minor, int lock)
{
struct pt_softc *pt = pt_softc[minor];
if (lock)
mutex_enter(&pt_softc_mutex);
minor = pt == NULL || pt->pt_tty == NULL ||
pt->pt_tty->t_oproc == NULL;
if (lock)
mutex_exit(&pt_softc_mutex);
return minor;
}

/*
* Allocate and zero array of nelem elements.
*/
static struct pt_softc **
ptyarralloc(int nelem)
{
struct pt_softc **pt;
nelem += 10;
pt = kmem_zalloc(nelem * sizeof(*pt), KM_SLEEP);
return pt;
}

static void
ptyarrfree(struct pt_softc **pt, int nelem)
{

nelem += 10;
kmem_free(pt, nelem * sizeof(*pt));
}

/*
* Check if the minor is correct and ensure necessary structures
* are properly allocated.
*/
int
pty_check(int ptn)
{
struct pt_softc *pti;

if (ptn >= npty) {
struct pt_softc **newpt, **oldpt;
int newnpty;
int oldnpty;

/* check if the requested pty can be granted */
if (ptn >= maxptys) {
limit_reached:
tablefull("pty", "increase kern.maxptys");
return ENXIO;
}

/* Allocate a larger pty array */
for (newnpty = npty; newnpty <= ptn;)
newnpty *= 2;
if (newnpty > maxptys)
newnpty = maxptys;
newpt = ptyarralloc(newnpty);

/*
* Now grab the pty array mutex - we need to ensure
* that the pty array is consistent while copying its
* content to newly allocated, larger space; we also
* need to be safe against pty_maxptys().
*/
mutex_enter(&pt_softc_mutex);

if (newnpty >= maxptys) {
/* limit cut away beneath us... */
if (ptn >= maxptys) {
mutex_exit(&pt_softc_mutex);
ptyarrfree(newpt, newnpty);
goto limit_reached;
}
newnpty = maxptys;
}

/*
* If the pty array was not enlarged while we were waiting
* for mutex, copy current contents of pt_softc[] to newly
* allocated array and start using the new bigger array.
*/
if (newnpty > npty) {
memcpy(newpt, pt_softc, npty*sizeof(struct pt_softc *));
oldpt = pt_softc;
oldnpty = npty;
pt_softc = newpt;
npty = newnpty;
} else {
/* was enlarged when waited for lock, free new space */
oldpt = newpt;
oldnpty = newnpty;
}

mutex_exit(&pt_softc_mutex);
ptyarrfree(oldpt, oldnpty);
}

/*
* If the entry is not yet allocated, allocate one. The mutex is
* needed so that the state of pt_softc[] array is consistant
* in case it has been lengthened above.
*/
if (!pt_softc[ptn]) {
pti = kmem_zalloc(sizeof(*pti), KM_SLEEP);

selinit(&pti->pt_selr);
selinit(&pti->pt_selw);
pti->pt_tty = tty_alloc();

mutex_enter(&pt_softc_mutex);

/*
* Check the entry again - it might have been
* added while we were waiting for mutex.
*/
if (pt_softc[ptn]) {
mutex_exit(&pt_softc_mutex);
tty_free(pti->pt_tty);
seldestroy(&pti->pt_selr);
seldestroy(&pti->pt_selw);
kmem_free(pti, sizeof(*pti));
return 0;
}
tty_attach(pti->pt_tty);
pt_softc[ptn] = pti;

mutex_exit(&pt_softc_mutex);
}

return 0;
}

/*
* Set maxpty in thread-safe way. Returns 0 in case of error, otherwise
* new value of maxptys.
*/
int
pty_maxptys(int newmax, int set)
{
if (!set)
return maxptys;

/*
* We have to grab the pt_softc lock, so that we would pick correct
* value of npty (might be modified in pty_check()).
*/
mutex_enter(&pt_softc_mutex);

/*
* The value cannot be set to value lower than the highest pty
* number ever allocated.
*/
if (newmax >= npty)
maxptys = newmax;
else
newmax = 0;

mutex_exit(&pt_softc_mutex);

return newmax;
}

/*
* Establish n (or default if n is 1) ptys in the system.
*/
void
ptyattach(int n)
{

mutex_init(&pt_softc_mutex, MUTEX_DEFAULT, IPL_NONE);

/* maybe should allow 0 => none? */
if (n <= 1)
n = DEFAULT_NPTYS;
pt_softc = ptyarralloc(n);
npty = n;
#ifndef NO_DEV_PTM
ptmattach(1);
#endif
}

/*ARGSUSED*/
int
ptsopen(dev_t dev, int flag, int devtype, struct lwp *l)
{
struct pt_softc *pti;
struct tty *tp;
int error;
int ptn = minor(dev);

if ((error = pty_check(ptn)) != 0)
return error;

mutex_spin_enter(&tty_lock);
pti = pt_softc[ptn];
tp = pti->pt_tty;
if (!ISSET(tp->t_state, TS_ISOPEN)) {
tp->t_dev = dev;
ttychars(tp); /* Set up default chars */
tp->t_iflag = TTYDEF_IFLAG;
tp->t_oflag = TTYDEF_OFLAG;
tp->t_lflag = TTYDEF_LFLAG;
tp->t_cflag = TTYDEF_CFLAG;
tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
ttsetwater(tp); /* would be done in xxparam() */
} else if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN,
tp) != 0) {
mutex_spin_exit(&tty_lock);
return EBUSY;
}
if (tp->t_oproc) /* Ctrlr still around. */
SET(tp->t_state, TS_CARR_ON);
if (!ISSET(flag, O_NONBLOCK)) {
while (!ISSET(tp->t_state, TS_CARR_ON)) {
tp->t_wopen++;
error = ttysleep(tp, &tp->t_rawcv, true, 0);
tp->t_wopen--;
if (error != 0) {
mutex_spin_exit(&tty_lock);
return error;
}
}
}
mutex_spin_exit(&tty_lock);
error = (*tp->t_linesw->l_open)(dev, tp);
ptcwakeup(tp, FREAD|FWRITE);
return error;
}

int
ptsclose(dev_t dev, int flag, int mode, struct lwp *l)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
int error;

error = (*tp->t_linesw->l_close)(tp, flag);
error |= ttyclose(tp);
ptcwakeup(tp, FREAD|FWRITE);
return error;
}

int
ptsread(dev_t dev, struct uio *uio, int flag)
{
struct proc *p = curproc;
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
int error = 0;
int cc, c;

again:
if (pti->pt_flags & PF_REMOTE) {
mutex_spin_enter(&tty_lock);
while (isbackground(p, tp)) { /* XXXSMP */
if (sigismasked(curlwp, SIGTTIN) ||
p->p_pgrp->pg_jobc == 0 ||
p->p_lflag & PL_PPWAIT) {
mutex_spin_exit(&tty_lock);
return EIO;
}
ttysig(tp, TTYSIG_PG1, SIGTTIN);
error = ttypause(tp, hz);
if (error != 0) {
mutex_spin_exit(&tty_lock);
return error;
}
}
if (tp->t_canq.c_cc == 0) {
if (flag & IO_NDELAY) {
mutex_spin_exit(&tty_lock);
return EWOULDBLOCK;
}
error = ttysleep(tp, &tp->t_cancv, true, 0);
mutex_spin_exit(&tty_lock);
if (error != 0)
return error;
goto again;
}
while(error == 0 && tp->t_canq.c_cc > 1 && uio->uio_resid > 0) {
c = getc(&tp->t_canq);
mutex_spin_exit(&tty_lock);
error = ureadc(c, uio);
mutex_spin_enter(&tty_lock);
/* Re-check terminal state here? */
}
if (tp->t_canq.c_cc == 1)
(void) getc(&tp->t_canq);
cc = tp->t_canq.c_cc;
mutex_spin_exit(&tty_lock);
if (cc)
return error;
} else if (tp->t_oproc)
error = (*tp->t_linesw->l_read)(tp, uio, flag);
ptcwakeup(tp, FWRITE);
return error;
}

/*
* Write to pseudo-tty.
* Wakeups of controlling tty will happen
* indirectly, when tty driver calls ptsstart.
*/
int
ptswrite(dev_t dev, struct uio *uio, int flag)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;

if (tp->t_oproc == NULL)
return EIO;
return (*tp->t_linesw->l_write)(tp, uio, flag);
}

/*
* Poll pseudo-tty.
*/
int
ptspoll(dev_t dev, int events, struct lwp *l)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;

if (tp->t_oproc == NULL)
return POLLHUP;

return (*tp->t_linesw->l_poll)(tp, events, l);
}

/*
* Start output on pseudo-tty.
* Wake up process polling or sleeping for input from controlling tty.
*/
void
ptsstart(struct tty *tp)
{
struct pt_softc *pti;

KASSERT(tp->t_dev != NODEV);
pti = pt_softc[minor(tp->t_dev)];

KASSERT(mutex_owned(&tty_lock));

if (ISSET(tp->t_state, TS_TTSTOP))
return;
if (pti->pt_flags & PF_STOPPED) {
pti->pt_flags &= ~PF_STOPPED;
pti->pt_send = TIOCPKT_START;
}

selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
cv_broadcast(&tp->t_outcvf);
}

/*
* Stop output.
*/
void
ptsstop(struct tty *tp, int flush)
{
struct pt_softc *pti;

KASSERT(tp->t_dev != NODEV);
pti = pt_softc[minor(tp->t_dev)];

KASSERT(mutex_owned(&tty_lock));

/* note: FLUSHREAD and FLUSHWRITE already ok */
CTASSERT(TIOCPKT_FLUSHREAD == FREAD);
CTASSERT(TIOCPKT_FLUSHWRITE == FWRITE);
if (flush == 0) {
flush = TIOCPKT_STOP;
pti->pt_flags |= PF_STOPPED;
} else
pti->pt_flags &= ~PF_STOPPED;
pti->pt_send |= flush;

/* change of perspective */
if (flush & FREAD) {
selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
cv_broadcast(&tp->t_rawcvf);
}
if (flush & FWRITE) {
selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
cv_broadcast(&tp->t_outcvf);
}
}

void
ptcwakeup(struct tty *tp, int flag)
{
struct pt_softc *pti;

if (tp->t_dev == NODEV)
return; /* client side not open yet */

pti = pt_softc[minor(tp->t_dev)];
KASSERT(pti != NULL);

mutex_spin_enter(&tty_lock);
if (flag & FREAD) {
selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
cv_broadcast(&tp->t_outcvf);
}
if (flag & FWRITE) {
selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
cv_broadcast(&tp->t_rawcvf);
}
mutex_spin_exit(&tty_lock);
}

/*ARGSUSED*/
int
ptcopen(dev_t dev, int flag, int devtype, struct lwp *l)
{
struct pt_softc *pti;
struct tty *tp;
int error;
int ptn = minor(dev);

if ((error = pty_check(ptn)) != 0)
return error;

pti = pt_softc[ptn];
tp = pti->pt_tty;

mutex_spin_enter(&tty_lock);
if (tp->t_oproc) {
mutex_spin_exit(&tty_lock);
return EIO;
}
tp->t_dev = dev;
tp->t_oproc = ptsstart;
mutex_spin_exit(&tty_lock);
(void)(*tp->t_linesw->l_modem)(tp, 1);
CLR(tp->t_lflag, EXTPROC);
pti->pt_flags = 0;
pti->pt_send = 0;
pti->pt_ucntl = 0;
return 0;
}

/*ARGSUSED*/
int
ptcclose(dev_t dev, int flag, int devtype, struct lwp *l)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;

(void)(*tp->t_linesw->l_modem)(tp, 0);
mutex_spin_enter(&tty_lock);
CLR(tp->t_state, TS_CARR_ON);
tp->t_oproc = NULL; /* mark closed */
mutex_spin_exit(&tty_lock);
return 0;
}

int
ptcread(dev_t dev, struct uio *uio, int flag)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
u_char bf[BUFSIZ];
int error = 0, cc;
int c;

if (uio->uio_resid <= 0)
return EINVAL;

/*
* We want to block until the slave
* is open, and there's something to read;
* but if we lost the slave or we're NBIO,
* then return the appropriate error instead.
*/
mutex_spin_enter(&tty_lock);
for (;;) {
if (ISSET(tp->t_state, TS_ISOPEN)) {
if (pti->pt_flags & PF_PKT && (c = pti->pt_send)) {
pti->pt_send = 0;
mutex_spin_exit(&tty_lock);
error = ureadc(c, uio);
if (error != 0)
return error;
/*
* Since we don't have the tty locked, there's
* a risk of messing up `t_termios'. This is
* relevant only if the tty got closed and then
* opened again while we were out uiomoving.
*/
if (c & TIOCPKT_IOCTL) {
cc = uimin(uio->uio_resid,
sizeof(tp->t_termios));
uiomove((void *) &tp->t_termios,
cc, uio);
}
return 0;
}
if (pti->pt_flags & PF_UCNTL && (c = pti->pt_ucntl)) {
pti->pt_ucntl = 0;
mutex_spin_exit(&tty_lock);
error = ureadc(c, uio);
if (error != 0)
return error;
return 0;
}
if (tp->t_outq.c_cc && !ISSET(tp->t_state, TS_TTSTOP))
break;
}
if (!ISSET(tp->t_state, TS_CARR_ON)) {
error = 0; /* EOF */
goto out;
}
if (flag & IO_NDELAY) {
error = EWOULDBLOCK;
goto out;
}
error = cv_wait_sig(&tp->t_outcvf, &tty_lock);
if (error != 0)
goto out;
}

if (pti->pt_flags & (PF_PKT|PF_UCNTL)) {
mutex_spin_exit(&tty_lock);
error = ureadc(0, uio);
mutex_spin_enter(&tty_lock);
if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
error = EIO;
}
while (uio->uio_resid > 0 && error == 0) {
cc = q_to_b(&tp->t_outq, bf, uimin(uio->uio_resid, BUFSIZ));
if (cc <= 0)
break;
mutex_spin_exit(&tty_lock);
error = uiomove(bf, cc, uio);
mutex_spin_enter(&tty_lock);
if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
error = EIO;
}
ttypull(tp);
out:
mutex_spin_exit(&tty_lock);
return error;
}

int
ptcwrite(dev_t dev, struct uio *uio, int flag)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
u_char *cp = NULL;
int cc = 0;
u_char locbuf[BUFSIZ];
int cnt = 0;
int error = 0;

again:
mutex_spin_enter(&tty_lock);
if (!ISSET(tp->t_state, TS_ISOPEN))
goto block;
if (pti->pt_flags & PF_REMOTE) {
if (tp->t_canq.c_cc)
goto block;
while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG) {
if (cc == 0) {
cc = uimin(uio->uio_resid, BUFSIZ);
cc = uimin(cc, TTYHOG - tp->t_canq.c_cc);
cp = locbuf;
mutex_spin_exit(&tty_lock);
error = uiomove(cp, cc, uio);
if (error != 0)
return error;
mutex_spin_enter(&tty_lock);
/* check again for safety */
if (!ISSET(tp->t_state, TS_ISOPEN)) {
/*
* adjust for data copied in but not
* written
*/
uio->uio_resid += cc;
error = EIO;
goto out;
}
}
if (cc) {
cc = b_to_q(cp, cc, &tp->t_outq);
if (cc > 0)
goto block;
}
}
(void) putc(0, &tp->t_canq);
ttwakeup(tp);
cv_broadcast(&tp->t_cancv);
error = 0;
goto out;
}
while (uio->uio_resid > 0) {
if (cc == 0) {
cc = uimin(uio->uio_resid, BUFSIZ);
cp = locbuf;
mutex_spin_exit(&tty_lock);
error = uiomove(cp, cc, uio);
if (error != 0)
return error;
mutex_spin_enter(&tty_lock);
/* check again for safety */
if (!ISSET(tp->t_state, TS_ISOPEN)) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
error = EIO;
goto out;
}
}
while (cc > 0) {
int used = tp->t_rawq.c_cc + tp->t_canq.c_cc;
int canon = ISSET(tp->t_lflag, ICANON) ? 1 : 0;
/*
* We need space for 2 characters if canonical
* because we might need to print ^C
*/
if (used >= (TTYHOG - canon) &&
(tp->t_canq.c_cc > 0 || !canon)) {
cv_broadcast(&tp->t_rawcv);
goto block;
}
/*
* XXX - should change l_rint to be called with lock
* see also tty.c:ttyinput_wlock()
*/
mutex_spin_exit(&tty_lock);
(*tp->t_linesw->l_rint)(*cp++, tp);
mutex_spin_enter(&tty_lock);
cnt++;
cc--;
}
}
error = 0;
goto out;

block:
/*
* Come here to wait for slave to open, for space
* in outq, or space in rawq.
*/
if (!ISSET(tp->t_state, TS_CARR_ON)) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
error = EIO;
goto out;
}
if (flag & IO_NDELAY) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
error = cnt == 0 ? EWOULDBLOCK : 0;
goto out;
}
error = cv_wait_sig(&tp->t_rawcvf, &tty_lock);
mutex_spin_exit(&tty_lock);
if (error != 0) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return error;
}
goto again;

out:
mutex_spin_exit(&tty_lock);
return error;
}

int
ptcpoll(dev_t dev, int events, struct lwp *l)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
int revents = 0;

mutex_spin_enter(&tty_lock);

if (events & (POLLIN | POLLRDNORM))
if (ISSET(tp->t_state, TS_ISOPEN) &&
((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
((pti->pt_flags & PF_PKT) && pti->pt_send) ||
((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)))
revents |= events & (POLLIN | POLLRDNORM);

if (events & (POLLOUT | POLLWRNORM))
if (ISSET(tp->t_state, TS_ISOPEN) &&
((pti->pt_flags & PF_REMOTE) ?
(tp->t_canq.c_cc == 0) :
((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
(tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))))
revents |= events & (POLLOUT | POLLWRNORM);

if (events & POLLHUP)
if (!ISSET(tp->t_state, TS_CARR_ON))
revents |= POLLHUP;

if (revents == 0) {
if (events & (POLLIN | POLLHUP | POLLRDNORM))
selrecord(l, &pti->pt_selr);

if (events & (POLLOUT | POLLWRNORM))
selrecord(l, &pti->pt_selw);
}

mutex_spin_exit(&tty_lock);

return revents;
}

static void
filt_ptcrdetach(struct knote *kn)
{
struct pt_softc *pti;

pti = kn->kn_hook;

mutex_spin_enter(&tty_lock);
selremove_knote(&pti->pt_selr, kn);
mutex_spin_exit(&tty_lock);
}

static int
filt_ptcread(struct knote *kn, long hint)
{
struct pt_softc *pti;
struct tty *tp;
int canread;

pti = kn->kn_hook;
tp = pti->pt_tty;

if ((hint & NOTE_SUBMIT) == 0) {
mutex_spin_enter(&tty_lock);
}

canread = (ISSET(tp->t_state, TS_ISOPEN) &&
((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
((pti->pt_flags & PF_PKT) && pti->pt_send) ||
((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)));

if (canread) {
/*
* c_cc is number of characters after output post-processing;
* the amount of data actually read(2) depends on
* setting of input flags for the terminal.
*/
kn->kn_data = tp->t_outq.c_cc;
if (((pti->pt_flags & PF_PKT) && pti->pt_send) ||
((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
kn->kn_data++;
}
if (!ISSET(tp->t_state, TS_CARR_ON)) {
knote_set_eof(kn, 0);
canread = 1;
}

if ((hint & NOTE_SUBMIT) == 0) {
mutex_spin_exit(&tty_lock);
}

return canread;
}

static void
filt_ptcwdetach(struct knote *kn)
{
struct pt_softc *pti;

pti = kn->kn_hook;

mutex_spin_enter(&tty_lock);
selremove_knote(&pti->pt_selw, kn);
mutex_spin_exit(&tty_lock);
}

static int
filt_ptcwrite(struct knote *kn, long hint)
{
struct pt_softc *pti;
struct tty *tp;
int canwrite;
int nwrite;

pti = kn->kn_hook;
tp = pti->pt_tty;

if ((hint & NOTE_SUBMIT) == 0) {
mutex_spin_enter(&tty_lock);
}

canwrite = (ISSET(tp->t_state, TS_ISOPEN) &&
((pti->pt_flags & PF_REMOTE) ?
(tp->t_canq.c_cc == 0) :
((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
(tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))));

if (canwrite) {
if (pti->pt_flags & PF_REMOTE)
nwrite = tp->t_canq.c_cn;
else {
/* this is guaranteed to be > 0 due to above check */
nwrite = tp->t_canq.c_cn
- (tp->t_rawq.c_cc + tp->t_canq.c_cc);
}
kn->kn_data = nwrite;
}

if ((hint & NOTE_SUBMIT) == 0) {
mutex_spin_exit(&tty_lock);
}

return canwrite;
}

static const struct filterops ptcread_filtops = {
.f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
.f_attach = NULL,
.f_detach = filt_ptcrdetach,
.f_event = filt_ptcread,
};

static const struct filterops ptcwrite_filtops = {
.f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
.f_attach = NULL,
.f_detach = filt_ptcwdetach,
.f_event = filt_ptcwrite,
};

int
ptckqfilter(dev_t dev, struct knote *kn)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct selinfo *sip;

switch (kn->kn_filter) {
case EVFILT_READ:
sip = &pti->pt_selr;
kn->kn_fop = &ptcread_filtops;
break;
case EVFILT_WRITE:
sip = &pti->pt_selw;
kn->kn_fop = &ptcwrite_filtops;
break;
default:
return EINVAL;
}

kn->kn_hook = pti;

mutex_spin_enter(&tty_lock);
selrecord_knote(sip, kn);
mutex_spin_exit(&tty_lock);

return 0;
}

struct tty *
ptytty(dev_t dev)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;

return tp;
}

/*ARGSUSED*/
int
ptyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
const struct cdevsw *cdev;
u_char *cc = tp->t_cc;
int stop, error, sig;
#ifndef NO_DEV_PTM
struct mount *mp;
#endif

/*
* IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
* ttywflush(tp) will hang if there are characters in the outq.
*/
if (cmd == TIOCEXT) {
/*
* When the EXTPROC bit is being toggled, we need
* to send an TIOCPKT_IOCTL if the packet driver
* is turned on.
*/
if (*(int *)data) {
if (pti->pt_flags & PF_PKT) {
pti->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
}
SET(tp->t_lflag, EXTPROC);
} else {
if (ISSET(tp->t_lflag, EXTPROC) &&
(pti->pt_flags & PF_PKT)) {
pti->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
}
CLR(tp->t_lflag, EXTPROC);
}
return(0);
}

#ifndef NO_DEV_PTM
/* Allow getting the name from either the master or the slave */
if (cmd == TIOCPTSNAME) {
if ((error = pty_getmp(l, &mp)) != 0)
return error;
return pty_fill_ptmget(l, dev, -1, -1, data, mp);
}
#endif

cdev = cdevsw_lookup(dev);
if (cdev != NULL && cdev->d_open == ptcopen)
switch (cmd) {
#ifndef NO_DEV_PTM
case TIOCGRANTPT:
if ((error = pty_getmp(l, &mp)) != 0)
return error;
return pty_grant_slave(l, dev, mp);
#endif

case TIOCGPGRP:
/*
* We avoid calling ttioctl on the controller since,
* in that case, tp must be the controlling terminal.
*/
*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
return 0;

case TIOCPKT:
if (*(int *)data) {
if (pti->pt_flags & PF_UCNTL)
return EINVAL;
pti->pt_flags |= PF_PKT;
} else
pti->pt_flags &= ~PF_PKT;
return 0;

case TIOCUCNTL:
if (*(int *)data) {
if (pti->pt_flags & PF_PKT)
return EINVAL;
pti->pt_flags |= PF_UCNTL;
} else
pti->pt_flags &= ~PF_UCNTL;
return 0;

case TIOCREMOTE:
if (*(int *)data)
pti->pt_flags |= PF_REMOTE;
else
pti->pt_flags &= ~PF_REMOTE;
mutex_spin_enter(&tty_lock);
ttyflush(tp, FREAD|FWRITE);
mutex_spin_exit(&tty_lock);
return 0;

case TIOCSETP:
case TIOCSETN:
case TIOCSETD:
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
mutex_spin_enter(&tty_lock);
ndflush(&tp->t_outq, tp->t_outq.c_cc);
mutex_spin_exit(&tty_lock);
break;

case TIOCSIG:
sig = (int)(long)*(void **)data;
if (sig <= 0 || sig >= NSIG)
return EINVAL;
mutex_spin_enter(&tty_lock);
if (!ISSET(tp->t_lflag, NOFLSH))
ttyflush(tp, FREAD|FWRITE);
tp->t_state |= TS_SIGINFO;
ttysig(tp, TTYSIG_PG1, sig);
mutex_spin_exit(&tty_lock);
return 0;

case FIONREAD:
mutex_spin_enter(&tty_lock);
*(int *)data = tp->t_outq.c_cc;
mutex_spin_exit(&tty_lock);
return 0;
}

error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
if (error == EPASSTHROUGH)
error = ttioctl(tp, cmd, data, flag, l);
if (error == EPASSTHROUGH) {
if (pti->pt_flags & PF_UCNTL &&
(cmd & ~0xff) == UIOCCMD(0)) {
if (cmd & 0xff) {
pti->pt_ucntl = (u_char)cmd;
ptcwakeup(tp, FREAD);
}
return 0;
}
}
/*
* If external processing and packet mode send ioctl packet.
*/
if (ISSET(tp->t_lflag, EXTPROC) && (pti->pt_flags & PF_PKT)) {
switch(cmd) {
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
case TIOCSETP:
case TIOCSETN:
case TIOCSETC:
case TIOCSLTC:
case TIOCLBIS:
case TIOCLBIC:
case TIOCLSET:
pti->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
default:
break;
}
}
stop = ISSET(tp->t_iflag, IXON) && CCEQ(cc[VSTOP], CTRL('s'))
&& CCEQ(cc[VSTART], CTRL('q'));
if (pti->pt_flags & PF_NOSTOP) {
if (stop) {
pti->pt_send &= ~TIOCPKT_NOSTOP;
pti->pt_send |= TIOCPKT_DOSTOP;
pti->pt_flags &= ~PF_NOSTOP;
ptcwakeup(tp, FREAD);
}
} else {
if (!stop) {
pti->pt_send &= ~TIOCPKT_DOSTOP;
pti->pt_send |= TIOCPKT_NOSTOP;
pti->pt_flags |= PF_NOSTOP;
ptcwakeup(tp, FREAD);
}
}
return error;
}