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29 * @(#)tty_pty.c 8.4 (Berkeley) 2/20/95
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 * Pseudo-teletype Driver
37 * (Actually two drivers, requiring two entries in 'cdevsw')
39 #include "opt_compat.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/mutex.h>
46 #if defined(COMPAT_43TTY)
47 #include <sys/ioctl_compat.h>
52 #include <sys/fcntl.h>
54 #include <sys/kernel.h>
56 #include <sys/signalvar.h>
57 #include <sys/malloc.h>
59 static MALLOC_DEFINE(M_PTY, "ptys", "pty data structures");
61 static void ptsstart(struct tty *tp);
62 static void ptsstop(struct tty *tp, int rw);
63 static void ptcwakeup(struct tty *tp, int flag);
64 static struct cdev *ptyinit(struct cdev *cdev, struct thread *td);
66 static d_open_t ptsopen;
67 static d_close_t ptsclose;
68 static d_read_t ptsread;
69 static d_write_t ptswrite;
70 static d_ioctl_t ptsioctl;
71 static d_open_t ptcopen;
72 static d_close_t ptcclose;
73 static d_read_t ptcread;
74 static d_ioctl_t ptcioctl;
75 static d_write_t ptcwrite;
76 static d_poll_t ptcpoll;
78 static struct cdevsw pts_cdevsw = {
79 .d_version = D_VERSION,
86 .d_flags = D_TTY | D_NEEDGIANT,
89 static struct cdevsw ptc_cdevsw = {
90 .d_version = D_VERSION,
98 .d_flags = D_TTY | D_NEEDGIANT,
101 #define BUFSIZ 100 /* Chunk size iomoved to/from user */
105 struct selinfo pt_selr, pt_selw;
109 struct cdev *devs, *devc;
110 struct prison *pt_prison;
113 #define PF_PKT 0x08 /* packet mode */
114 #define PF_STOPPED 0x10 /* user told stopped */
115 #define PF_NOSTOP 0x40
116 #define PF_UCNTL 0x80 /* user control mode */
118 #define TSA_PTC_READ(tp) ((void *)&(tp)->t_outq.c_cf)
119 #define TSA_PTC_WRITE(tp) ((void *)&(tp)->t_rawq.c_cl)
120 #define TSA_PTS_READ(tp) ((void *)&(tp)->t_canq)
122 static char *names = "pqrsPQRS";
124 * This function creates and initializes a pts/ptc pair
126 * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
127 * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
129 * XXX: define and add mapping of upper minor bits to allow more
133 ptyinit(struct cdev *devc, struct thread *td)
140 /* For now we only map the lower 8 bits of the minor */
144 devc->si_flags &= ~SI_CHEAPCLONE;
146 pt = malloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
147 pt->devs = devs = make_dev_cred(&pts_cdevsw, n, td->td_ucred,
148 UID_ROOT, GID_WHEEL, 0666, "tty%c%r", names[n / 32], n % 32);
151 pt->pt_tty = ttyalloc();
152 pt->pt_tty->t_sc = pt;
153 devs->si_drv1 = devc->si_drv1 = pt;
154 devs->si_tty = devc->si_tty = pt->pt_tty;
155 pt->pt_tty->t_dev = devs;
161 ptsopen(struct cdev *dev, int flag, int devtype, struct thread *td)
171 if ((tp->t_state & TS_ISOPEN) == 0) {
172 ttyinitmode(tp, 1, 0);
173 } else if (tp->t_state & TS_XCLUDE && suser(td))
175 else if (pt->pt_prison != td->td_ucred->cr_prison)
177 if (tp->t_oproc) /* Ctrlr still around. */
178 (void)ttyld_modem(tp, 1);
179 while ((tp->t_state & TS_CARR_ON) == 0) {
182 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
187 error = ttyld_open(tp, dev);
189 ptcwakeup(tp, FREAD|FWRITE);
194 ptsclose(struct cdev *dev, int flag, int mode, struct thread *td)
200 err = ttyld_close(tp, flag);
201 (void) tty_close(tp);
206 ptsread(struct cdev *dev, struct uio *uio, int flag)
208 struct tty *tp = dev->si_tty;
212 error = ttyld_read(tp, uio, flag);
213 ptcwakeup(tp, FWRITE);
218 * Write to pseudo-tty.
219 * Wakeups of controlling tty will happen
220 * indirectly, when tty driver calls ptsstart.
223 ptswrite(struct cdev *dev, struct uio *uio, int flag)
228 if (tp->t_oproc == 0)
230 return (ttyld_write(tp, uio, flag));
234 * Start output on pseudo-tty.
235 * Wake up process selecting or sleeping for input from controlling tty.
238 ptsstart(struct tty *tp)
240 struct ptsc *pt = tp->t_sc;
242 if (tp->t_state & TS_TTSTOP)
244 if (pt->pt_flags & PF_STOPPED) {
245 pt->pt_flags &= ~PF_STOPPED;
246 pt->pt_send = TIOCPKT_START;
248 ptcwakeup(tp, FREAD);
252 ptcwakeup(struct tty *tp, int flag)
254 struct ptsc *pt = tp->t_sc;
257 selwakeuppri(&pt->pt_selr, TTIPRI);
258 wakeup(TSA_PTC_READ(tp));
261 selwakeuppri(&pt->pt_selw, TTOPRI);
262 wakeup(TSA_PTC_WRITE(tp));
267 ptcopen(struct cdev *dev, int flag, int devtype, struct thread *td)
280 tp->t_oproc = ptsstart;
281 tp->t_stop = ptsstop;
282 (void)ttyld_modem(tp, 1);
283 tp->t_lflag &= ~EXTPROC;
285 pt->pt_prison = td->td_ucred->cr_prison;
293 ptcclose(struct cdev *dev, int flags, int fmt, struct thread *td)
298 (void)ttyld_modem(tp, 0);
301 * XXX MDMBUF makes no sense for ptys but would inhibit the above
302 * l_modem(). CLOCAL makes sense but isn't supported. Special
303 * l_modem()s that ignore carrier drop make no sense for ptys but
304 * may be in use because other parts of the line discipline make
305 * sense for ptys. Recover by doing everything that a normal
306 * ttymodem() would have done except for sending a SIGHUP.
308 if (tp->t_state & TS_ISOPEN) {
309 tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
310 tp->t_state |= TS_ZOMBIE;
311 ttyflush(tp, FREAD | FWRITE);
314 tp->t_oproc = 0; /* mark closed */
319 ptcread(struct cdev *dev, struct uio *uio, int flag)
321 struct tty *tp = dev->si_tty;
322 struct ptsc *pt = dev->si_drv1;
327 * We want to block until the slave
328 * is open, and there's something to read;
329 * but if we lost the slave or we're NBIO,
330 * then return the appropriate error instead.
333 if (tp->t_state&TS_ISOPEN) {
334 if (pt->pt_flags&PF_PKT && pt->pt_send) {
335 error = ureadc((int)pt->pt_send, uio);
338 if (pt->pt_send & TIOCPKT_IOCTL) {
339 cc = min(uio->uio_resid,
340 sizeof(tp->t_termios));
341 uiomove(&tp->t_termios, cc, uio);
346 if (pt->pt_flags&PF_UCNTL && pt->pt_ucntl) {
347 error = ureadc((int)pt->pt_ucntl, uio);
353 if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
356 if ((tp->t_state & TS_CONNECTED) == 0)
357 return (0); /* EOF */
358 if (flag & O_NONBLOCK)
359 return (EWOULDBLOCK);
360 error = tsleep(TSA_PTC_READ(tp), TTIPRI | PCATCH, "ptcin", 0);
364 if (pt->pt_flags & (PF_PKT|PF_UCNTL))
365 error = ureadc(0, uio);
366 while (uio->uio_resid > 0 && error == 0) {
367 cc = q_to_b(&tp->t_outq, buf, min(uio->uio_resid, BUFSIZ));
370 error = uiomove(buf, cc, uio);
377 ptsstop(struct tty *tp, int flush)
379 struct ptsc *pt = tp->t_sc;
382 /* note: FLUSHREAD and FLUSHWRITE already ok */
384 flush = TIOCPKT_STOP;
385 pt->pt_flags |= PF_STOPPED;
387 pt->pt_flags &= ~PF_STOPPED;
388 pt->pt_send |= flush;
389 /* change of perspective */
399 ptcpoll(struct cdev *dev, int events, struct thread *td)
401 struct tty *tp = dev->si_tty;
402 struct ptsc *pt = dev->si_drv1;
406 if ((tp->t_state & TS_CONNECTED) == 0)
408 (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM));
411 * Need to block timeouts (ttrstart).
415 if (events & (POLLIN | POLLRDNORM))
416 if ((tp->t_state & TS_ISOPEN) &&
417 ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
418 ((pt->pt_flags & PF_PKT) && pt->pt_send) ||
419 ((pt->pt_flags & PF_UCNTL) && pt->pt_ucntl)))
420 revents |= events & (POLLIN | POLLRDNORM);
422 if (events & (POLLOUT | POLLWRNORM))
423 if (tp->t_state & TS_ISOPEN &&
424 (((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
425 (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON)))))
426 revents |= events & (POLLOUT | POLLWRNORM);
428 if (events & POLLHUP)
429 if ((tp->t_state & TS_CARR_ON) == 0)
433 if (events & (POLLIN | POLLRDNORM))
434 selrecord(td, &pt->pt_selr);
436 if (events & (POLLOUT | POLLWRNORM))
437 selrecord(td, &pt->pt_selw);
445 ptcwrite(struct cdev *dev, struct uio *uio, int flag)
447 struct tty *tp = dev->si_tty;
450 u_char locbuf[BUFSIZ];
455 if ((tp->t_state&TS_ISOPEN) == 0)
457 while (uio->uio_resid > 0 || cc > 0) {
459 cc = min(uio->uio_resid, BUFSIZ);
461 error = uiomove(cp, cc, uio);
464 /* check again for safety */
465 if ((tp->t_state & TS_ISOPEN) == 0) {
466 /* adjust for data copied in but not written */
467 uio->uio_resid += cc;
472 if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
473 (tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) {
474 wakeup(TSA_HUP_OR_INPUT(tp));
477 ttyld_rint(tp, *cp++);
486 * Come here to wait for slave to open, for space
487 * in outq, or space in rawq, or an empty canq.
489 if ((tp->t_state & TS_CONNECTED) == 0) {
490 /* adjust for data copied in but not written */
491 uio->uio_resid += cc;
494 if (flag & O_NONBLOCK) {
495 /* adjust for data copied in but not written */
496 uio->uio_resid += cc;
498 return (EWOULDBLOCK);
501 error = tsleep(TSA_PTC_WRITE(tp), TTOPRI | PCATCH, "ptcout", 0);
503 /* adjust for data copied in but not written */
504 uio->uio_resid += cc;
512 ptcioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
514 struct tty *tp = dev->si_tty;
515 struct ptsc *pt = dev->si_drv1;
521 * We avoid calling ttioctl on the controller since,
522 * in that case, tp must be the controlling terminal.
524 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
529 if (pt->pt_flags & PF_UCNTL)
531 pt->pt_flags |= PF_PKT;
533 pt->pt_flags &= ~PF_PKT;
538 if (pt->pt_flags & PF_PKT)
540 pt->pt_flags |= PF_UCNTL;
542 pt->pt_flags &= ~PF_UCNTL;
547 * The rest of the ioctls shouldn't be called until
550 if ((tp->t_state & TS_ISOPEN) == 0)
563 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
564 * ttywflush(tp) will hang if there are characters in
567 ndflush(&tp->t_outq, tp->t_outq.c_cc);
571 if (*(unsigned int *)data >= NSIG ||
572 *(unsigned int *)data == 0)
574 if ((tp->t_lflag&NOFLSH) == 0)
575 ttyflush(tp, FREAD|FWRITE);
576 if (tp->t_pgrp != NULL) {
577 PGRP_LOCK(tp->t_pgrp);
578 pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
579 PGRP_UNLOCK(tp->t_pgrp);
581 if ((*(unsigned int *)data == SIGINFO) &&
582 ((tp->t_lflag&NOKERNINFO) == 0))
587 return (ptsioctl(dev, cmd, data, flag, td));
592 ptsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
594 struct tty *tp = dev->si_tty;
595 struct ptsc *pt = dev->si_drv1;
596 u_char *cc = tp->t_cc;
599 if (cmd == TIOCEXT) {
601 * When the EXTPROC bit is being toggled, we need
602 * to send an TIOCPKT_IOCTL if the packet driver
606 if (pt->pt_flags & PF_PKT) {
607 pt->pt_send |= TIOCPKT_IOCTL;
608 ptcwakeup(tp, FREAD);
610 tp->t_lflag |= EXTPROC;
612 if ((tp->t_lflag & EXTPROC) &&
613 (pt->pt_flags & PF_PKT)) {
614 pt->pt_send |= TIOCPKT_IOCTL;
615 ptcwakeup(tp, FREAD);
617 tp->t_lflag &= ~EXTPROC;
621 error = ttyioctl(dev, cmd, data, flag, td);
622 if (error == ENOTTY) {
623 if (pt->pt_flags & PF_UCNTL &&
624 (cmd & ~0xff) == UIOCCMD(0)) {
626 pt->pt_ucntl = (u_char)cmd;
627 ptcwakeup(tp, FREAD);
634 * If external processing and packet mode send ioctl packet.
636 if ((tp->t_lflag&EXTPROC) && (pt->pt_flags & PF_PKT)) {
650 pt->pt_send |= TIOCPKT_IOCTL;
651 ptcwakeup(tp, FREAD);
657 stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
658 && CCEQ(cc[VSTART], CTRL('q'));
659 if (pt->pt_flags & PF_NOSTOP) {
661 pt->pt_send &= ~TIOCPKT_NOSTOP;
662 pt->pt_send |= TIOCPKT_DOSTOP;
663 pt->pt_flags &= ~PF_NOSTOP;
664 ptcwakeup(tp, FREAD);
668 pt->pt_send &= ~TIOCPKT_DOSTOP;
669 pt->pt_send |= TIOCPKT_NOSTOP;
670 pt->pt_flags |= PF_NOSTOP;
671 ptcwakeup(tp, FREAD);
678 pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
685 if (bcmp(name, "pty", 3) != 0)
690 case 'p': u = 0; break;
691 case 'q': u = 32; break;
692 case 'r': u = 64; break;
693 case 's': u = 96; break;
694 case 'P': u = 128; break;
695 case 'Q': u = 160; break;
696 case 'R': u = 192; break;
697 case 'S': u = 224; break;
700 if (name[4] >= '0' && name[4] <= '9')
702 else if (name[4] >= 'a' && name[4] <= 'v')
703 u += name[4] - 'a' + 10;
706 *dev = make_dev_cred(&ptc_cdevsw, u, cr,
707 UID_ROOT, GID_WHEEL, 0666, "pty%c%r", names[u / 32], u % 32);
709 (*dev)->si_flags |= SI_CHEAPCLONE;
714 ptc_drvinit(void *unused)
717 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
720 SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ptc_drvinit,NULL)