Source to kern/tty_pty.c
/*
* Copyright (c) 1982, 1986, 1989 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 7.21 (Berkeley) 5/30/91
*/
static char rcsid[] = "$Header: /usr/bill/working/sys/kern/RCS/tty_pty.c,v 1.3 92/01/21 21:31:23 william Exp $";
/*
* Pseudo-teletype Driver
* (Actually two drivers, requiring two entries in 'cdevsw')
*/
#include "pty.h"
#if NPTY > 0
#include "param.h"
#include "systm.h"
#include "ioctl.h"
#include "tty.h"
#include "conf.h"
#include "file.h"
#include "proc.h"
#include "uio.h"
#include "kernel.h"
#include "vnode.h"
#if NPTY == 1
#undef NPTY
#define NPTY 32 /* crude XXX */
#endif
#define BUFSIZ 100 /* Chunk size iomoved to/from user */
/*
* pts == /dev/tty[pqrs]?
* ptc == /dev/pty[pqrs]?
*/
struct tty pt_tty[NPTY];
struct pt_ioctl {
int pt_flags;
struct proc *pt_selr, *pt_selw;
u_char pt_send;
u_char pt_ucntl;
} pt_ioctl[NPTY];
int npty = NPTY; /* for pstat -t */
#define PF_RCOLL 0x01
#define PF_WCOLL 0x02
#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 */
/*ARGSUSED*/
ptsopen(dev, flag, devtype, p)
dev_t dev;
struct proc *p;
{
register struct tty *tp;
int error;
#ifdef lint
npty = npty;
#endif
if (minor(dev) >= NPTY)
return (ENXIO);
tp = &pt_tty[minor(dev)];
if ((tp->t_state & TS_ISOPEN) == 0) {
tp->t_state |= TS_WOPEN;
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 (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
return (EBUSY);
if (tp->t_oproc) /* Ctrlr still around. */
tp->t_state |= TS_CARR_ON;
while ((tp->t_state & TS_CARR_ON) == 0) {
tp->t_state |= TS_WOPEN;
if (flag&FNONBLOCK)
break;
if (error = ttysleep(tp, (caddr_t)&tp->t_raw, TTIPRI | PCATCH,
ttopen, 0))
return (error);
}
error = (*linesw[tp->t_line].l_open)(dev, tp, flag);
ptcwakeup(tp, FREAD|FWRITE);
return (error);
}
ptsclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
register struct tty *tp;
tp = &pt_tty[minor(dev)];
(*linesw[tp->t_line].l_close)(tp, flag);
ttyclose(tp);
ptcwakeup(tp, FREAD|FWRITE);
}
ptsread(dev, uio, flag)
dev_t dev;
struct uio *uio;
{
struct proc *p = curproc;
register struct tty *tp = &pt_tty[minor(dev)];
register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
int error = 0;
again:
if (pti->pt_flags & PF_REMOTE) {
while (isbackground(p, tp)) {
if ((p->p_sigignore & sigmask(SIGTTIN)) ||
(p->p_sigmask & sigmask(SIGTTIN)) ||
p->p_pgrp->pg_jobc == 0 ||
p->p_flag&SPPWAIT)
return (EIO);
pgsignal(p->p_pgrp, SIGTTIN, 1);
if (error = ttysleep(tp, (caddr_t)&lbolt,
TTIPRI | PCATCH, ttybg, 0))
return (error);
}
if (RB_LEN(&tp->t_can) == 0) {
if (flag & IO_NDELAY)
return (EWOULDBLOCK);
if (error = ttysleep(tp, (caddr_t)&tp->t_can,
TTIPRI | PCATCH, ttyin, 0))
return (error);
goto again;
}
while (RB_LEN(&tp->t_can) > 1 && uio->uio_resid > 0)
if (ureadc(getc(&tp->t_can), uio) < 0) {
error = EFAULT;
break;
}
if (RB_LEN(&tp->t_can) == 1)
(void) getc(&tp->t_can);
if (RB_LEN(&tp->t_can))
return (error);
} else
if (tp->t_oproc)
error = (*linesw[tp->t_line].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.
*/
ptswrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
{
register struct tty *tp;
tp = &pt_tty[minor(dev)];
if (tp->t_oproc == 0)
return (EIO);
return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}
/*
* Start output on pseudo-tty.
* Wake up process selecting or sleeping for input from controlling tty.
*/
ptsstart(tp)
struct tty *tp;
{
register struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
if (tp->t_state & TS_TTSTOP)
return;
if (pti->pt_flags & PF_STOPPED) {
pti->pt_flags &= ~PF_STOPPED;
pti->pt_send = TIOCPKT_START;
}
ptcwakeup(tp, FREAD);
}
ptcwakeup(tp, flag)
struct tty *tp;
{
struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
if (flag & FREAD) {
if (pti->pt_selr) {
selwakeup(pti->pt_selr, pti->pt_flags & PF_RCOLL);
pti->pt_selr = 0;
pti->pt_flags &= ~PF_RCOLL;
}
wakeup((caddr_t)&tp->t_out.rb_hd);
}
if (flag & FWRITE) {
if (pti->pt_selw) {
selwakeup(pti->pt_selw, pti->pt_flags & PF_WCOLL);
pti->pt_selw = 0;
pti->pt_flags &= ~PF_WCOLL;
}
wakeup((caddr_t)&tp->t_raw.rb_hd);
}
}
/*ARGSUSED*/
#ifdef __STDC__
ptcopen(dev_t dev, int flag, int devtype, struct proc *p)
#else
ptcopen(dev, flag, devtype, p)
dev_t dev;
int flag, devtype;
struct proc *p;
#endif
{
register struct tty *tp;
struct pt_ioctl *pti;
if (minor(dev) >= NPTY)
return (ENXIO);
tp = &pt_tty[minor(dev)];
if (tp->t_oproc)
return (EIO);
tp->t_oproc = ptsstart;
(void)(*linesw[tp->t_line].l_modem)(tp, 1);
tp->t_lflag &= ~EXTPROC;
pti = &pt_ioctl[minor(dev)];
pti->pt_flags = 0;
pti->pt_send = 0;
pti->pt_ucntl = 0;
return (0);
}
ptcclose(dev)
dev_t dev;
{
register struct tty *tp;
tp = &pt_tty[minor(dev)];
(void)(*linesw[tp->t_line].l_modem)(tp, 0);
tp->t_state &= ~TS_CARR_ON;
tp->t_oproc = 0; /* mark closed */
tp->t_session = 0;
}
ptcread(dev, uio, flag)
dev_t dev;
struct uio *uio;
{
register struct tty *tp = &pt_tty[minor(dev)];
struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
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.
*/
for (;;) {
if (tp->t_state&TS_ISOPEN) {
if (pti->pt_flags&PF_PKT && pti->pt_send) {
error = ureadc((int)pti->pt_send, uio);
if (error)
return (error);
if (pti->pt_send & TIOCPKT_IOCTL) {
cc = MIN(uio->uio_resid,
sizeof(tp->t_termios));
uiomove(&tp->t_termios, cc, uio);
}
pti->pt_send = 0;
return (0);
}
if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) {
error = ureadc((int)pti->pt_ucntl, uio);
if (error)
return (error);
pti->pt_ucntl = 0;
return (0);
}
if (RB_LEN(&tp->t_out) && (tp->t_state&TS_TTSTOP) == 0)
break;
}
if ((tp->t_state&TS_CARR_ON) == 0)
return (0); /* EOF */
if (flag & IO_NDELAY)
return (EWOULDBLOCK);
if (error = tsleep((caddr_t)&tp->t_out.rb_hd, TTIPRI | PCATCH,
ttyin, 0))
return (error);
}
if (pti->pt_flags & (PF_PKT|PF_UCNTL))
error = ureadc(0, uio);
while (uio->uio_resid > 0 && error == 0) {
#ifdef was
cc = q_to_b(&tp->t_outq, buf, MIN(uio->uio_resid, BUFSIZ));
#else
cc = min(MIN(uio->uio_resid, BUFSIZ), RB_CONTIGGET(&tp->t_out));
if (cc) {
bcopy(tp->t_out.rb_hd, buf, cc);
tp->t_out.rb_hd =
RB_ROLLOVER(&tp->t_out, tp->t_out.rb_hd+cc);
}
#endif
if (cc <= 0)
break;
error = uiomove(buf, cc, uio);
}
if (RB_LEN(&tp->t_out) <= tp->t_lowat) {
if (tp->t_state&TS_ASLEEP) {
tp->t_state &= ~TS_ASLEEP;
wakeup((caddr_t)&tp->t_out);
}
if (tp->t_wsel) {
selwakeup(tp->t_wsel, tp->t_state & TS_WCOLL);
tp->t_wsel = 0;
tp->t_state &= ~TS_WCOLL;
}
}
return (error);
}
ptsstop(tp, flush)
register struct tty *tp;
int flush;
{
struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
int flag;
/* 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 */
flag = 0;
if (flush & FREAD)
flag |= FWRITE;
if (flush & FWRITE)
flag |= FREAD;
ptcwakeup(tp, flag);
}
ptcselect(dev, rw, p)
dev_t dev;
int rw;
struct proc *p;
{
register struct tty *tp = &pt_tty[minor(dev)];
struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
struct proc *prev;
int s;
if ((tp->t_state&TS_CARR_ON) == 0)
return (1);
switch (rw) {
case FREAD:
/*
* Need to block timeouts (ttrstart).
*/
s = spltty();
if ((tp->t_state&TS_ISOPEN) &&
RB_LEN(&tp->t_out) && (tp->t_state&TS_TTSTOP) == 0) {
splx(s);
return (1);
}
splx(s);
/* FALLTHROUGH */
case 0: /* exceptional */
if ((tp->t_state&TS_ISOPEN) &&
(pti->pt_flags&PF_PKT && pti->pt_send ||
pti->pt_flags&PF_UCNTL && pti->pt_ucntl))
return (1);
if ((prev = pti->pt_selr) && prev->p_wchan == (caddr_t)&selwait)
pti->pt_flags |= PF_RCOLL;
else
pti->pt_selr = p;
break;
case FWRITE:
if (tp->t_state&TS_ISOPEN) {
if (pti->pt_flags & PF_REMOTE) {
if (RB_LEN(&tp->t_can) == 0)
return (1);
} else {
if (RB_LEN(&tp->t_raw) + RB_LEN(&tp->t_can) < TTYHOG-2)
return (1);
if (RB_LEN(&tp->t_can) == 0 && (tp->t_iflag&ICANON))
return (1);
}
}
if ((prev = pti->pt_selw) && prev->p_wchan == (caddr_t)&selwait)
pti->pt_flags |= PF_WCOLL;
else
pti->pt_selw = p;
break;
}
return (0);
}
ptcwrite(dev, uio, flag)
dev_t dev;
register struct uio *uio;
{
register struct tty *tp = &pt_tty[minor(dev)];
register u_char *cp;
register int cc = 0;
u_char locbuf[BUFSIZ];
int cnt = 0;
struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
int error = 0;
again:
if ((tp->t_state&TS_ISOPEN) == 0)
goto block;
if (pti->pt_flags & PF_REMOTE) {
if (RB_LEN(&tp->t_can))
goto block;
while (uio->uio_resid > 0 && RB_LEN(&tp->t_can) < TTYHOG - 1) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cc = min(cc, TTYHOG - 1 - RB_CONTIGPUT(&tp->t_can));
cp = locbuf;
error = uiomove((caddr_t)cp, cc, uio);
if (error)
return (error);
/* check again for safety */
if ((tp->t_state&TS_ISOPEN) == 0)
return (EIO);
}
#ifdef was
if (cc)
(void) b_to_q((char *)cp, cc, &tp->t_canq);
#else
if (cc) {
bcopy(cp, tp->t_can.rb_tl, cc);
tp->t_can.rb_tl =
RB_ROLLOVER(&tp->t_can, tp->t_can.rb_tl+cc);
}
#endif
cc = 0;
}
(void) putc(0, &tp->t_can);
ttwakeup(tp);
wakeup((caddr_t)&tp->t_can);
return (0);
}
while (uio->uio_resid > 0) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cp = locbuf;
error = uiomove((caddr_t)cp, cc, uio);
if (error)
return (error);
/* check again for safety */
if ((tp->t_state&TS_ISOPEN) == 0)
return (EIO);
}
while (cc > 0) {
if ((RB_LEN(&tp->t_raw) + RB_LEN(&tp->t_can)) >= TTYHOG - 2 &&
(RB_LEN(&tp->t_can) > 0 || !(tp->t_iflag&ICANON))) {
wakeup((caddr_t)&tp->t_raw);
goto block;
}
(*linesw[tp->t_line].l_rint)(*cp++, tp);
cnt++;
cc--;
}
cc = 0;
}
return (0);
block:
/*
* Come here to wait for slave to open, for space
* in outq, or space in rawq.
*/
if ((tp->t_state&TS_CARR_ON) == 0)
return (EIO);
if (flag & IO_NDELAY) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
if (cnt == 0)
return (EWOULDBLOCK);
return (0);
}
if (error = tsleep((caddr_t)&tp->t_raw.rb_hd, TTOPRI | PCATCH,
ttyout, 0)) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (error);
}
goto again;
}
/*ARGSUSED*/
ptyioctl(dev, cmd, data, flag)
caddr_t data;
dev_t dev;
{
register struct tty *tp = &pt_tty[minor(dev)];
register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
register u_char *cc = tp->t_cc;
int stop, error;
extern ttyinput();
/*
* 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);
}
tp->t_lflag |= EXTPROC;
} else {
if ((tp->t_state & EXTPROC) &&
(pti->pt_flags & PF_PKT)) {
pti->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
}
tp->t_lflag &= ~EXTPROC;
}
return(0);
} else
if (cdevsw[major(dev)].d_open == ptcopen)
switch (cmd) {
case TIOCGPGRP:
/*
* We aviod 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;
ttyflush(tp, FREAD|FWRITE);
return (0);
case TIOCSETP:
case TIOCSETN:
case TIOCSETD:
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
while (getc(&tp->t_out) >= 0)
;
break;
case TIOCSIG:
if (*(unsigned int *)data >= NSIG)
return(EINVAL);
if ((tp->t_lflag&NOFLSH) == 0)
ttyflush(tp, FREAD|FWRITE);
pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
if ((*(unsigned int *)data == SIGINFO) &&
((tp->t_lflag&NOKERNINFO) == 0))
ttyinfo(tp);
return(0);
}
error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag);
if (error < 0)
error = ttioctl(tp, cmd, data, flag);
/*
* Since we use the tty queues internally,
* pty's can't be switched to disciplines which overwrite
* the queues. We can't tell anything about the discipline
* from here...
*/
if (linesw[tp->t_line].l_rint != ttyinput) {
(*linesw[tp->t_line].l_close)(tp, flag);
tp->t_line = TTYDISC;
(void)(*linesw[tp->t_line].l_open)(dev, tp, flag);
error = ENOTTY;
}
if (error < 0) {
if (pti->pt_flags & PF_UCNTL &&
(cmd & ~0xff) == UIOCCMD(0)) {
if (cmd & 0xff) {
pti->pt_ucntl = (u_char)cmd;
ptcwakeup(tp, FREAD);
}
return (0);
}
error = ENOTTY;
}
/*
* If external processing and packet mode send ioctl packet.
*/
if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) {
switch(cmd) {
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
case TIOCSETP:
case TIOCSETN:
#ifdef COMPAT_43
case TIOCSETC:
case TIOCSLTC:
case TIOCLBIS:
case TIOCLBIC:
case TIOCLSET:
#endif
pti->pt_send |= TIOCPKT_IOCTL;
default:
break;
}
}
stop = (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);
}
#endif