NetBSD/sys/kern/tty_pty.c
dsl cfb2dd92f0 Fix (and simplify) interaction between check_pty() and pty_maxptys().
Lock setting/clearing of tp->t_oproc to guarantee concurrent opens can't
both suceed and that code in tty.c can't get a NULL t_oproc if the value
is re-read after being checked.
There are still MP issues with pt_flags, pt_send and pt_unctl.
Maybe problems that require TTY_LOCK() to be taken before calling std tty
functions.
2003-07-23 13:10:28 +00:00

1122 lines
25 KiB
C

/* $NetBSD: tty_pty.c,v 1.71 2003/07/23 13:10:28 dsl 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 1.71 2003/07/23 13:10:28 dsl Exp $");
#include "opt_compat_sunos.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/poll.h>
#include <sys/malloc.h>
#define DEFAULT_NPTYS 16 /* default number of initial ptys */
#define DEFAULT_MAXPTYS 992 /* default maximum number of ptys */
/* Macros to clear/set/test flags. */
#define SET(t, f) (t) |= (f)
#define CLR(t, f) (t) &= ~((unsigned)(f))
#define ISSET(t, f) ((t) & (f))
#define BUFSIZ 100 /* Chunk size iomoved to/from user */
/*
* pts == /dev/tty[pqrs]?
* ptc == /dev/pty[pqrs]?
*/
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 npty = 0; /* for pstat -t */
static int maxptys = DEFAULT_MAXPTYS; /* maximum number of ptys (sysctable) */
static struct simplelock pt_softc_mutex = SIMPLELOCK_INITIALIZER;
#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 ptyattach __P((int));
void ptcwakeup __P((struct tty *, int));
void ptsstart __P((struct tty *));
int pty_maxptys __P((int, int));
static struct pt_softc **ptyarralloc __P((int));
static int check_pty(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 = {
ptcopen, ptcclose, ptcread, ptcwrite, ptyioctl,
nullstop, ptytty, ptcpoll, nommap, ptckqfilter, D_TTY
};
const struct cdevsw pts_cdevsw = {
ptsopen, ptsclose, ptsread, ptswrite, ptyioctl,
ptsstop, ptytty, ptspoll, nommap, ttykqfilter, D_TTY
};
#if defined(pmax)
const struct cdevsw ptc_ultrix_cdevsw = {
ptcopen, ptcclose, ptcread, ptcwrite, ptyioctl,
nullstop, ptytty, ptcpoll, nommap, ptckqfilter, D_TTY
};
const struct cdevsw pts_ultrix_cdevsw = {
ptsopen, ptsclose, ptsread, ptswrite, ptyioctl,
ptsstop, ptytty, ptspoll, nommap, ttykqfilter, D_TTY
};
#endif /* defined(pmax) */
/*
* Allocate and zero array of nelem elements.
*/
static struct pt_softc **
ptyarralloc(nelem)
int nelem;
{
struct pt_softc **pt;
nelem += 10;
pt = malloc(nelem * sizeof *pt, M_DEVBUF, M_WAITOK | M_ZERO);
return pt;
}
/*
* Check if the minor is correct and ensure necessary structures
* are properly allocated.
*/
static int
check_pty(int ptn)
{
struct pt_softc *pti;
if (ptn >= npty) {
struct pt_softc **newpt, **oldpt;
int newnpty;
/* 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 it's
* content to newly allocated, larger space; we also
* need to be safe against pty_maxptys().
*/
simple_lock(&pt_softc_mutex);
if (newnpty >= maxptys) {
/* limit cut away beneath us... */
newnpty = maxptys;
if (ptn >= newnpty) {
simple_unlock(&pt_softc_mutex);
free(newpt, M_DEVBUF);
goto limit_reached;
}
}
/*
* 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;
pt_softc = newpt;
npty = newnpty;
} else {
/* was enlarged when waited for lock, free new space */
oldpt = newpt;
}
simple_unlock(&pt_softc_mutex);
free(oldpt, M_DEVBUF);
}
/*
* 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]) {
MALLOC(pti, struct pt_softc *, sizeof(struct pt_softc),
M_DEVBUF, M_WAITOK);
memset(pti, 0, sizeof(struct pt_softc));
pti->pt_tty = ttymalloc();
simple_lock(&pt_softc_mutex);
/*
* Check the entry again - it might have been
* added while we were waiting for mutex.
*/
if (!pt_softc[ptn]) {
tty_attach(pti->pt_tty);
pt_softc[ptn] = pti;
} else {
ttyfree(pti->pt_tty);
free(pti, M_DEVBUF);
}
simple_unlock(&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(newmax, set)
int newmax, 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 check_pty()).
*/
simple_lock(&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;
simple_unlock(&pt_softc_mutex);
return newmax;
}
/*
* Establish n (or default if n is 1) ptys in the system.
*/
void
ptyattach(n)
int n;
{
/* maybe should allow 0 => none? */
if (n <= 1)
n = DEFAULT_NPTYS;
pt_softc = ptyarralloc(n);
npty = n;
}
/*ARGSUSED*/
int
ptsopen(dev, flag, devtype, p)
dev_t dev;
int flag, devtype;
struct proc *p;
{
struct pt_softc *pti;
struct tty *tp;
int error;
int ptn = minor(dev);
if ((error = check_pty(ptn)))
return (error);
pti = pt_softc[ptn];
tp = pti->pt_tty;
if (!ISSET(tp->t_state, TS_ISOPEN)) {
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 (ISSET(tp->t_state, TS_XCLUDE) && p->p_ucred->cr_uid != 0)
return (EBUSY);
if (tp->t_oproc) /* Ctrlr still around. */
SET(tp->t_state, TS_CARR_ON);
if (!ISSET(flag, O_NONBLOCK)) {
TTY_LOCK(tp);
while (!ISSET(tp->t_state, TS_CARR_ON)) {
tp->t_wopen++;
error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
ttopen, 0);
tp->t_wopen--;
if (error) {
TTY_UNLOCK(tp);
return (error);
}
}
TTY_UNLOCK(tp);
}
error = (*tp->t_linesw->l_open)(dev, tp);
ptcwakeup(tp, FREAD|FWRITE);
return (error);
}
int
ptsclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
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, uio, flag)
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;
again:
if (pti->pt_flags & PF_REMOTE) {
while (isbackground(p, tp)) {
if (sigismasked(p, SIGTTIN) ||
p->p_pgrp->pg_jobc == 0 ||
p->p_flag & P_PPWAIT)
return (EIO);
pgsignal(p->p_pgrp, SIGTTIN, 1);
TTY_LOCK(tp);
error = ttysleep(tp, (caddr_t)&lbolt,
TTIPRI | PCATCH | PNORELOCK, ttybg, 0);
if (error)
return (error);
}
TTY_LOCK(tp);
if (tp->t_canq.c_cc == 0) {
if (flag & IO_NDELAY) {
TTY_UNLOCK(tp);
return (EWOULDBLOCK);
}
error = ttysleep(tp, (caddr_t)&tp->t_canq,
TTIPRI | PCATCH | PNORELOCK, ttyin, 0);
if (error)
return (error);
goto again;
}
while(error == 0 && tp->t_canq.c_cc > 1 && uio->uio_resid > 0) {
TTY_UNLOCK(tp);
error = ureadc(getc(&tp->t_canq), uio);
TTY_LOCK(tp);
/* Re-check terminal state here? */
}
if (tp->t_canq.c_cc == 1)
(void) getc(&tp->t_canq);
cc = tp->t_canq.c_cc;
TTY_UNLOCK(tp);
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, uio, flag)
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 == 0)
return (EIO);
return ((*tp->t_linesw->l_write)(tp, uio, flag));
}
/*
* Poll pseudo-tty.
*/
int
ptspoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
if (tp->t_oproc == 0)
return (EIO);
return ((*tp->t_linesw->l_poll)(tp, events, p));
}
/*
* Start output on pseudo-tty.
* Wake up process polling or sleeping for input from controlling tty.
* Called with tty slock held.
*/
void
ptsstart(tp)
struct tty *tp;
{
struct pt_softc *pti = pt_softc[minor(tp->t_dev)];
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);
wakeup((caddr_t)&tp->t_outq.c_cf);
}
/*
* Stop output.
* Called with tty slock held.
*/
void
ptsstop(tp, flush)
struct tty *tp;
int flush;
{
struct pt_softc *pti = pt_softc[minor(tp->t_dev)];
/* note: FLUSHREAD and FLUSHWRITE already ok */
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);
wakeup((caddr_t)&tp->t_rawq.c_cf);
}
if (flush & FWRITE) {
selnotify(&pti->pt_selr, 0);
wakeup((caddr_t)&tp->t_outq.c_cf);
}
}
void
ptcwakeup(tp, flag)
struct tty *tp;
int flag;
{
struct pt_softc *pti = pt_softc[minor(tp->t_dev)];
TTY_LOCK(tp);
if (flag & FREAD) {
selnotify(&pti->pt_selr, 0);
wakeup((caddr_t)&tp->t_outq.c_cf);
}
if (flag & FWRITE) {
selnotify(&pti->pt_selw, 0);
wakeup((caddr_t)&tp->t_rawq.c_cf);
}
TTY_UNLOCK(tp);
}
/*ARGSUSED*/
int
ptcopen(dev, flag, devtype, p)
dev_t dev;
int flag, devtype;
struct proc *p;
{
struct pt_softc *pti;
struct tty *tp;
int error;
int ptn = minor(dev);
if ((error = check_pty(ptn)))
return (error);
pti = pt_softc[ptn];
tp = pti->pt_tty;
TTY_LOCK(tp);
if (tp->t_oproc) {
TTY_UNLOCK(tp);
return (EIO);
}
tp->t_oproc = ptsstart;
TTY_UNLOCK(tp);
(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, flag, devtype, p)
dev_t dev;
int flag, devtype;
struct proc *p;
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
(void)(*tp->t_linesw->l_modem)(tp, 0);
CLR(tp->t_state, TS_CARR_ON);
TTY_LOCK(tp);
tp->t_oproc = 0; /* mark closed */
TTY_UNLOCK(tp);
return (0);
}
int
ptcread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
u_char buf[BUFSIZ];
int error = 0, cc;
/*
* 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.
*/
TTY_LOCK(tp);
for (;;) {
if (ISSET(tp->t_state, TS_ISOPEN)) {
if (pti->pt_flags & PF_PKT && pti->pt_send) {
TTY_UNLOCK(tp);
error = ureadc((int)pti->pt_send, uio);
if (error)
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 (pti->pt_send & TIOCPKT_IOCTL) {
cc = min(uio->uio_resid,
sizeof(tp->t_termios));
uiomove((caddr_t) &tp->t_termios,
cc, uio);
}
pti->pt_send = 0;
return (0);
}
if (pti->pt_flags & PF_UCNTL && pti->pt_ucntl) {
TTY_UNLOCK(tp);
error = ureadc((int)pti->pt_ucntl, uio);
if (error)
return (error);
pti->pt_ucntl = 0;
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 = ltsleep((caddr_t)&tp->t_outq.c_cf, TTIPRI | PCATCH,
ttyin, 0, &tp->t_slock);
if (error)
goto out;
}
if (pti->pt_flags & (PF_PKT|PF_UCNTL)) {
TTY_UNLOCK(tp);
error = ureadc(0, uio);
TTY_LOCK(tp);
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, buf, min(uio->uio_resid, BUFSIZ));
if (cc <= 0)
break;
TTY_UNLOCK(tp);
error = uiomove(buf, cc, uio);
TTY_LOCK(tp);
if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
error = EIO;
}
if (tp->t_outq.c_cc <= tp->t_lowat) {
if (ISSET(tp->t_state, TS_ASLEEP)) {
CLR(tp->t_state, TS_ASLEEP);
wakeup((caddr_t)&tp->t_outq);
}
selnotify(&tp->t_wsel, 0);
}
out:
TTY_UNLOCK(tp);
return (error);
}
int
ptcwrite(dev, uio, flag)
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:
TTY_LOCK(tp);
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 - 1) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cc = min(cc, TTYHOG - 1 - tp->t_canq.c_cc);
cp = locbuf;
TTY_UNLOCK(tp);
error = uiomove((caddr_t)cp, cc, uio);
if (error)
return (error);
TTY_LOCK(tp);
/* check again for safety */
if (!ISSET(tp->t_state, TS_ISOPEN)) {
error = EIO;
goto out;
}
}
if (cc)
(void) b_to_q(cp, cc, &tp->t_canq);
cc = 0;
}
(void) putc(0, &tp->t_canq);
ttwakeup(tp);
wakeup((caddr_t)&tp->t_canq);
error = 0;
goto out;
}
while (uio->uio_resid > 0) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cp = locbuf;
TTY_UNLOCK(tp);
error = uiomove((caddr_t)cp, cc, uio);
if (error)
return (error);
TTY_LOCK(tp);
/* check again for safety */
if (!ISSET(tp->t_state, TS_ISOPEN)) {
error = EIO;
goto out;
}
}
while (cc > 0) {
if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
(tp->t_canq.c_cc > 0 || !ISSET(tp->t_lflag, ICANON))) {
wakeup((caddr_t)&tp->t_rawq);
goto block;
}
/* XXX - should change l_rint to be called with lock
* see also tty.c:ttyinput_wlock()
*/
TTY_UNLOCK(tp);
(*tp->t_linesw->l_rint)(*cp++, tp);
TTY_LOCK(tp);
cnt++;
cc--;
}
cc = 0;
}
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)) {
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 = ltsleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI | PCATCH | PNORELOCK,
ttyout, 0, &tp->t_slock);
if (error) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (error);
}
goto again;
out:
TTY_UNLOCK(tp);
return (error);
}
int
ptcpoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
int revents = 0;
int s = splsoftclock();
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(p, &pti->pt_selr);
if (events & (POLLOUT | POLLWRNORM))
selrecord(p, &pti->pt_selw);
}
splx(s);
return (revents);
}
static void
filt_ptcrdetach(struct knote *kn)
{
struct pt_softc *pti;
int s;
pti = kn->kn_hook;
s = spltty();
SLIST_REMOVE(&pti->pt_selr.sel_klist, kn, knote, kn_selnext);
splx(s);
}
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;
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++;
}
return (canread);
}
static void
filt_ptcwdetach(struct knote *kn)
{
struct pt_softc *pti;
int s;
pti = kn->kn_hook;
s = spltty();
SLIST_REMOVE(&pti->pt_selw.sel_klist, kn, knote, kn_selnext);
splx(s);
}
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;
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;
}
return (canwrite);
}
static const struct filterops ptcread_filtops =
{ 1, NULL, filt_ptcrdetach, filt_ptcread };
static const struct filterops ptcwrite_filtops =
{ 1, NULL, filt_ptcwdetach, filt_ptcwrite };
int
ptckqfilter(dev_t dev, struct knote *kn)
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct klist *klist;
int s;
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &pti->pt_selr.sel_klist;
kn->kn_fop = &ptcread_filtops;
break;
case EVFILT_WRITE:
klist = &pti->pt_selw.sel_klist;
kn->kn_fop = &ptcwrite_filtops;
break;
default:
return (1);
}
kn->kn_hook = pti;
s = spltty();
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
splx(s);
return (0);
}
struct tty *
ptytty(dev)
dev_t dev;
{
struct pt_softc *pti = pt_softc[minor(dev)];
struct tty *tp = pti->pt_tty;
return (tp);
}
/*ARGSUSED*/
int
ptyioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
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;
cdev = cdevsw_lookup(dev);
/*
* 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);
}
if (cdev != NULL && cdev->d_open == ptcopen)
switch (cmd) {
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;
TTY_LOCK(tp);
ttyflush(tp, FREAD|FWRITE);
TTY_UNLOCK(tp);
return (0);
#ifdef COMPAT_OLDTTY
case TIOCSETP:
case TIOCSETN:
#endif
case TIOCSETD:
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
TTY_LOCK(tp);
ndflush(&tp->t_outq, tp->t_outq.c_cc);
TTY_UNLOCK(tp);
break;
case TIOCSIG:
sig = (int)(long)*(caddr_t *)data;
if (sig <= 0 || sig >= NSIG)
return (EINVAL);
TTY_LOCK(tp);
if (!ISSET(tp->t_lflag, NOFLSH))
ttyflush(tp, FREAD|FWRITE);
if ((sig == SIGINFO) &&
(!ISSET(tp->t_lflag, NOKERNINFO)))
ttyinfo(tp);
TTY_UNLOCK(tp);
pgsignal(tp->t_pgrp, sig, 1);
return(0);
}
error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
if (error == EPASSTHROUGH)
error = ttioctl(tp, cmd, data, flag, p);
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:
#ifdef COMPAT_OLDTTY
case TIOCSETP:
case TIOCSETN:
case TIOCSETC:
case TIOCSLTC:
case TIOCLBIS:
case TIOCLBIC:
case TIOCLSET:
#endif
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);
}