FreeBSD-5.3/sys/kern/tty_pty.c
/*
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/tty_pty.c,v 1.129 2004/07/15 20:47:40 phk Exp $");
/*
* Pseudo-teletype Driver
* (Actually two drivers, requiring two entries in 'cdevsw')
*/
#include "opt_compat.h"
#include "opt_tty.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#ifndef BURN_BRIDGES
#if defined(COMPAT_43)
#include <sys/ioctl_compat.h>
#endif
#endif
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/poll.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
static MALLOC_DEFINE(M_PTY, "ptys", "pty data structures");
static void ptsstart(struct tty *tp);
static void ptsstop(struct tty *tp, int rw);
static void ptcwakeup(struct tty *tp, int flag);
static struct cdev *ptyinit(struct cdev *cdev);
static d_open_t ptsopen;
static d_close_t ptsclose;
static d_read_t ptsread;
static d_write_t ptswrite;
static d_ioctl_t ptyioctl;
static d_open_t ptcopen;
static d_close_t ptcclose;
static d_read_t ptcread;
static d_write_t ptcwrite;
static d_poll_t ptcpoll;
#define CDEV_MAJOR_S 5
static struct cdevsw pts_cdevsw = {
.d_version = D_VERSION,
.d_open = ptsopen,
.d_close = ptsclose,
.d_read = ptsread,
.d_write = ptswrite,
.d_ioctl = ptyioctl,
.d_name = "pts",
.d_maj = CDEV_MAJOR_S,
.d_flags = D_TTY | D_NEEDGIANT,
};
#define CDEV_MAJOR_C 6
static struct cdevsw ptc_cdevsw = {
.d_version = D_VERSION,
.d_open = ptcopen,
.d_close = ptcclose,
.d_read = ptcread,
.d_write = ptcwrite,
.d_ioctl = ptyioctl,
.d_poll = ptcpoll,
.d_name = "ptc",
.d_maj = CDEV_MAJOR_C,
.d_flags = D_TTY | D_NEEDGIANT,
};
#define BUFSIZ 100 /* Chunk size iomoved to/from user */
struct ptsc {
int pt_flags;
struct selinfo pt_selr, pt_selw;
u_char pt_send;
u_char pt_ucntl;
struct tty *pt_tty;
struct cdev *devs, *devc;
struct prison *pt_prison;
};
#define PF_PKT 0x08 /* packet mode */
#define PF_STOPPED 0x10 /* user told stopped */
#define PF_NOSTOP 0x40
#define PF_UCNTL 0x80 /* user control mode */
#define TSA_PTC_READ(tp) ((void *)&(tp)->t_outq.c_cf)
#define TSA_PTC_WRITE(tp) ((void *)&(tp)->t_rawq.c_cl)
#define TSA_PTS_READ(tp) ((void *)&(tp)->t_canq)
static char *names = "pqrsPQRS";
/*
* This function creates and initializes a pts/ptc pair
*
* pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
* ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
*
* XXX: define and add mapping of upper minor bits to allow more
* than 256 ptys.
*/
static struct cdev *
ptyinit(struct cdev *devc)
{
struct cdev *devs;
struct ptsc *pt;
int n;
n = minor(devc);
/* For now we only map the lower 8 bits of the minor */
if (n & ~0xff)
return (NULL);
devc->si_flags &= ~SI_CHEAPCLONE;
pt = malloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
pt->devs = devs = make_dev(&pts_cdevsw, n,
UID_ROOT, GID_WHEEL, 0666, "tty%c%r", names[n / 32], n % 32);
pt->devc = devc;
pt->pt_tty = ttymalloc(pt->pt_tty);
devs->si_drv1 = devc->si_drv1 = pt;
devs->si_tty = devc->si_tty = pt->pt_tty;
pt->pt_tty->t_dev = devs;
return (devc);
}
/*ARGSUSED*/
static int
ptsopen(struct cdev *dev, int flag, int devtype, struct thread *td)
{
struct tty *tp;
int error;
struct ptsc *pt;
if (!dev->si_drv1)
return(ENXIO);
pt = dev->si_drv1;
tp = dev->si_tty;
if ((tp->t_state & TS_ISOPEN) == 0) {
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;
} else if (tp->t_state & TS_XCLUDE && suser(td))
return (EBUSY);
else if (pt->pt_prison != td->td_ucred->cr_prison)
return (EBUSY);
if (tp->t_oproc) /* Ctrlr still around. */
(void)ttyld_modem(tp, 1);
while ((tp->t_state & TS_CARR_ON) == 0) {
if (flag&FNONBLOCK)
break;
error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
"ptsopn", 0);
if (error)
return (error);
}
error = ttyld_open(tp, dev);
if (error == 0)
ptcwakeup(tp, FREAD|FWRITE);
return (error);
}
static int
ptsclose(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct tty *tp;
int err;
tp = dev->si_tty;
err = ttyld_close(tp, flag);
(void) tty_close(tp);
return (err);
}
static int
ptsread(struct cdev *dev, struct uio *uio, int flag)
{
struct tty *tp = dev->si_tty;
int error = 0;
if (tp->t_oproc)
error = ttyld_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.
*/
static int
ptswrite(struct cdev *dev, struct uio *uio, int flag)
{
struct tty *tp;
tp = dev->si_tty;
if (tp->t_oproc == 0)
return (EIO);
return (ttyld_write(tp, uio, flag));
}
/*
* Start output on pseudo-tty.
* Wake up process selecting or sleeping for input from controlling tty.
*/
static void
ptsstart(struct tty *tp)
{
struct ptsc *pt = tp->t_dev->si_drv1;
if (tp->t_state & TS_TTSTOP)
return;
if (pt->pt_flags & PF_STOPPED) {
pt->pt_flags &= ~PF_STOPPED;
pt->pt_send = TIOCPKT_START;
}
ptcwakeup(tp, FREAD);
}
static void
ptcwakeup(struct tty *tp, int flag)
{
struct ptsc *pt = tp->t_dev->si_drv1;
if (flag & FREAD) {
selwakeuppri(&pt->pt_selr, TTIPRI);
wakeup(TSA_PTC_READ(tp));
}
if (flag & FWRITE) {
selwakeuppri(&pt->pt_selw, TTOPRI);
wakeup(TSA_PTC_WRITE(tp));
}
}
static int
ptcopen(struct cdev *dev, int flag, int devtype, struct thread *td)
{
struct tty *tp;
struct ptsc *pt;
if (!dev->si_drv1)
ptyinit(dev);
if (!dev->si_drv1)
return(ENXIO);
tp = dev->si_tty;
if (tp->t_oproc)
return (EIO);
tp->t_timeout = -1;
tp->t_oproc = ptsstart;
tp->t_stop = ptsstop;
(void)ttyld_modem(tp, 1);
tp->t_lflag &= ~EXTPROC;
pt = dev->si_drv1;
pt->pt_prison = td->td_ucred->cr_prison;
pt->pt_flags = 0;
pt->pt_send = 0;
pt->pt_ucntl = 0;
return (0);
}
static int
ptcclose(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct tty *tp;
tp = dev->si_tty;
(void)ttyld_modem(tp, 0);
/*
* XXX MDMBUF makes no sense for ptys but would inhibit the above
* l_modem(). CLOCAL makes sense but isn't supported. Special
* l_modem()s that ignore carrier drop make no sense for ptys but
* may be in use because other parts of the line discipline make
* sense for ptys. Recover by doing everything that a normal
* ttymodem() would have done except for sending a SIGHUP.
*/
if (tp->t_state & TS_ISOPEN) {
tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
tp->t_state |= TS_ZOMBIE;
ttyflush(tp, FREAD | FWRITE);
}
tp->t_oproc = 0; /* mark closed */
return (0);
}
static int
ptcread(struct cdev *dev, struct uio *uio, int flag)
{
struct tty *tp = dev->si_tty;
struct ptsc *pt = dev->si_drv1;
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 (pt->pt_flags&PF_PKT && pt->pt_send) {
error = ureadc((int)pt->pt_send, uio);
if (error)
return (error);
if (pt->pt_send & TIOCPKT_IOCTL) {
cc = min(uio->uio_resid,
sizeof(tp->t_termios));
uiomove(&tp->t_termios, cc, uio);
}
pt->pt_send = 0;
return (0);
}
if (pt->pt_flags&PF_UCNTL && pt->pt_ucntl) {
error = ureadc((int)pt->pt_ucntl, uio);
if (error)
return (error);
pt->pt_ucntl = 0;
return (0);
}
if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
break;
}
if ((tp->t_state & TS_CONNECTED) == 0)
return (0); /* EOF */
if (flag & IO_NDELAY)
return (EWOULDBLOCK);
error = tsleep(TSA_PTC_READ(tp), TTIPRI | PCATCH, "ptcin", 0);
if (error)
return (error);
}
if (pt->pt_flags & (PF_PKT|PF_UCNTL))
error = ureadc(0, uio);
while (uio->uio_resid > 0 && error == 0) {
cc = q_to_b(&tp->t_outq, buf, min(uio->uio_resid, BUFSIZ));
if (cc <= 0)
break;
error = uiomove(buf, cc, uio);
}
ttwwakeup(tp);
return (error);
}
static void
ptsstop(struct tty *tp, int flush)
{
struct ptsc *pt = tp->t_dev->si_drv1;
int flag;
/* note: FLUSHREAD and FLUSHWRITE already ok */
if (flush == 0) {
flush = TIOCPKT_STOP;
pt->pt_flags |= PF_STOPPED;
} else
pt->pt_flags &= ~PF_STOPPED;
pt->pt_send |= flush;
/* change of perspective */
flag = 0;
if (flush & FREAD)
flag |= FWRITE;
if (flush & FWRITE)
flag |= FREAD;
ptcwakeup(tp, flag);
}
static int
ptcpoll(struct cdev *dev, int events, struct thread *td)
{
struct tty *tp = dev->si_tty;
struct ptsc *pt = dev->si_drv1;
int revents = 0;
int s;
if ((tp->t_state & TS_CONNECTED) == 0)
return (events &
(POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM));
/*
* Need to block timeouts (ttrstart).
*/
s = spltty();
if (events & (POLLIN | POLLRDNORM))
if ((tp->t_state & TS_ISOPEN) &&
((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
((pt->pt_flags & PF_PKT) && pt->pt_send) ||
((pt->pt_flags & PF_UCNTL) && pt->pt_ucntl)))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (tp->t_state & TS_ISOPEN &&
(((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
(tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON)))))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & POLLHUP)
if ((tp->t_state & TS_CARR_ON) == 0)
revents |= POLLHUP;
if (revents == 0) {
if (events & (POLLIN | POLLRDNORM))
selrecord(td, &pt->pt_selr);
if (events & (POLLOUT | POLLWRNORM))
selrecord(td, &pt->pt_selw);
}
splx(s);
return (revents);
}
static int
ptcwrite(struct cdev *dev, struct uio *uio, int flag)
{
struct tty *tp = dev->si_tty;
u_char *cp = 0;
int cc = 0;
u_char locbuf[BUFSIZ];
int cnt = 0;
int error = 0;
again:
if ((tp->t_state&TS_ISOPEN) == 0)
goto block;
while (uio->uio_resid > 0 || cc > 0) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cp = locbuf;
error = uiomove(cp, cc, uio);
if (error)
return (error);
/* check again for safety */
if ((tp->t_state & TS_ISOPEN) == 0) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (EIO);
}
}
while (cc > 0) {
if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
(tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) {
wakeup(TSA_HUP_OR_INPUT(tp));
goto block;
}
ttyld_rint(tp, *cp++);
cnt++;
cc--;
}
cc = 0;
}
return (0);
block:
/*
* Come here to wait for slave to open, for space
* in outq, or space in rawq, or an empty canq.
*/
if ((tp->t_state & TS_CONNECTED) == 0) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
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);
}
error = tsleep(TSA_PTC_WRITE(tp), TTOPRI | PCATCH, "ptcout", 0);
if (error) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (error);
}
goto again;
}
/*ARGSUSED*/
static int
ptyioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct tty *tp = dev->si_tty;
struct ptsc *pt = dev->si_drv1;
u_char *cc = tp->t_cc;
int stop, error;
if (devsw(dev)->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 (pt->pt_flags & PF_UCNTL)
return (EINVAL);
pt->pt_flags |= PF_PKT;
} else
pt->pt_flags &= ~PF_PKT;
return (0);
case TIOCUCNTL:
if (*(int *)data) {
if (pt->pt_flags & PF_PKT)
return (EINVAL);
pt->pt_flags |= PF_UCNTL;
} else
pt->pt_flags &= ~PF_UCNTL;
return (0);
}
/*
* The rest of the ioctls shouldn't be called until
* the slave is open.
*/
if ((tp->t_state & TS_ISOPEN) == 0)
return (EAGAIN);
switch (cmd) {
#ifndef BURN_BRIDGES
#ifdef COMPAT_43
case TIOCSETP:
case TIOCSETN:
#endif
#endif
case TIOCSETD:
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
/*
* IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
* ttywflush(tp) will hang if there are characters in
* the outq.
*/
ndflush(&tp->t_outq, tp->t_outq.c_cc);
break;
case TIOCSIG:
if (*(unsigned int *)data >= NSIG ||
*(unsigned int *)data == 0)
return(EINVAL);
if ((tp->t_lflag&NOFLSH) == 0)
ttyflush(tp, FREAD|FWRITE);
if (tp->t_pgrp != NULL) {
PGRP_LOCK(tp->t_pgrp);
pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
PGRP_UNLOCK(tp->t_pgrp);
}
if ((*(unsigned int *)data == SIGINFO) &&
((tp->t_lflag&NOKERNINFO) == 0))
ttyinfo(tp);
return(0);
}
}
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 (pt->pt_flags & PF_PKT) {
pt->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
}
tp->t_lflag |= EXTPROC;
} else {
if ((tp->t_lflag & EXTPROC) &&
(pt->pt_flags & PF_PKT)) {
pt->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
}
tp->t_lflag &= ~EXTPROC;
}
return(0);
}
error = ttyioctl(dev, cmd, data, flag, td);
if (error == ENOTTY) {
if (pt->pt_flags & PF_UCNTL &&
(cmd & ~0xff) == UIOCCMD(0)) {
if (cmd & 0xff) {
pt->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) && (pt->pt_flags & PF_PKT)) {
switch(cmd) {
case TIOCSETA:
case TIOCSETAW:
case TIOCSETAF:
#ifndef BURN_BRIDGES
#ifdef COMPAT_43
case TIOCSETP:
case TIOCSETN:
case TIOCSETC:
case TIOCSLTC:
case TIOCLBIS:
case TIOCLBIC:
case TIOCLSET:
#endif
#endif
pt->pt_send |= TIOCPKT_IOCTL;
ptcwakeup(tp, FREAD);
break;
default:
break;
}
}
stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
&& CCEQ(cc[VSTART], CTRL('q'));
if (pt->pt_flags & PF_NOSTOP) {
if (stop) {
pt->pt_send &= ~TIOCPKT_NOSTOP;
pt->pt_send |= TIOCPKT_DOSTOP;
pt->pt_flags &= ~PF_NOSTOP;
ptcwakeup(tp, FREAD);
}
} else {
if (!stop) {
pt->pt_send &= ~TIOCPKT_DOSTOP;
pt->pt_send |= TIOCPKT_NOSTOP;
pt->pt_flags |= PF_NOSTOP;
ptcwakeup(tp, FREAD);
}
}
return (error);
}
static void
pty_clone(void *arg, char *name, int namelen, struct cdev **dev)
{
int u;
if (*dev != NULL)
return;
if (bcmp(name, "pty", 3) != 0)
return;
if (name[5] != '\0')
return;
switch (name[3]) {
case 'p': u = 0; break;
case 'q': u = 32; break;
case 'r': u = 64; break;
case 's': u = 96; break;
case 'P': u = 128; break;
case 'Q': u = 160; break;
case 'R': u = 192; break;
case 'S': u = 224; break;
default: return;
}
if (name[4] >= '0' && name[4] <= '9')
u += name[4] - '0';
else if (name[4] >= 'a' && name[4] <= 'v')
u += name[4] - 'a' + 10;
else
return;
*dev = make_dev(&ptc_cdevsw, u,
UID_ROOT, GID_WHEEL, 0666, "pty%c%r", names[u / 32], u % 32);
(*dev)->si_flags |= SI_CHEAPCLONE;
return;
}
static void
ptc_drvinit(void *unused)
{
EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
}
SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR_C,ptc_drvinit,NULL)