tty_pty.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*      $NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $    */
    2 
    3 /*
    4  * Copyright (c) 1982, 1986, 1989, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)tty_pty.c   8.4 (Berkeley) 2/20/95
   32  */
   33 
   34 /*
   35  * Pseudo-teletype Driver
   36  * (Actually two drivers, requiring two entries in 'cdevsw')
   37  */
   38 
   39 #include <sys/cdefs.h>
   40 __KERNEL_RCSID(0, "$NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $");
   41 
   42 #include "opt_ptm.h"
   43 
   44 #define TTY_ALLOW_PRIVATE
   45 
   46 #include <sys/param.h>
   47 #include <sys/systm.h>
   48 #include <sys/ioctl.h>
   49 #include <sys/ioctl_compat.h>
   50 #include <sys/proc.h>
   51 #include <sys/tty.h>
   52 #include <sys/stat.h>
   53 #include <sys/file.h>
   54 #include <sys/kernel.h>
   55 #include <sys/vnode.h>
   56 #include <sys/namei.h>
   57 #include <sys/signalvar.h>
   58 #include <sys/uio.h>
   59 #include <sys/filedesc.h>
   60 #include <sys/conf.h>
   61 #include <sys/poll.h>
   62 #include <sys/pty.h>
   63 #include <sys/kauth.h>
   64 
   65 #include "ioconf.h"
   66 
   67 #define DEFAULT_NPTYS           16      /* default number of initial ptys */
   68 #define DEFAULT_MAXPTYS         992     /* default maximum number of ptys */
   69 
   70 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
   71 
   72 struct  pt_softc {
   73         struct  tty *pt_tty;
   74         int     pt_flags;
   75         struct  selinfo pt_selr, pt_selw;
   76         u_char  pt_send;
   77         u_char  pt_ucntl;
   78 };
   79 
   80 static struct pt_softc **pt_softc = NULL;       /* pty array */
   81 static int maxptys = DEFAULT_MAXPTYS;   /* maximum number of ptys (sysctable) */
   82 kmutex_t pt_softc_mutex;
   83 int npty = 0;                   /* for pstat -t */
   84 
   85 #define PF_PKT          0x08            /* packet mode */
   86 #define PF_STOPPED      0x10            /* user told stopped */
   87 #define PF_REMOTE       0x20            /* remote and flow controlled input */
   88 #define PF_NOSTOP       0x40
   89 #define PF_UCNTL        0x80            /* user control mode */
   90 
   91 void    ptcwakeup(struct tty *, int);
   92 void    ptsstart(struct tty *);
   93 int     pty_maxptys(int, int);
   94 
   95 static struct pt_softc **ptyarralloc(int);
   96 
   97 dev_type_open(ptcopen);
   98 dev_type_close(ptcclose);
   99 dev_type_read(ptcread);
  100 dev_type_write(ptcwrite);
  101 dev_type_poll(ptcpoll);
  102 dev_type_kqfilter(ptckqfilter);
  103 
  104 dev_type_open(ptsopen);
  105 dev_type_close(ptsclose);
  106 dev_type_read(ptsread);
  107 dev_type_write(ptswrite);
  108 dev_type_stop(ptsstop);
  109 dev_type_poll(ptspoll);
  110 
  111 dev_type_ioctl(ptyioctl);
  112 dev_type_tty(ptytty);
  113 
  114 const struct cdevsw ptc_cdevsw = {
  115         .d_open = ptcopen,
  116         .d_close = ptcclose,
  117         .d_read = ptcread,
  118         .d_write = ptcwrite,
  119         .d_ioctl = ptyioctl,
  120         .d_stop = nullstop,
  121         .d_tty = ptytty,
  122         .d_poll = ptcpoll,
  123         .d_mmap = nommap,
  124         .d_kqfilter = ptckqfilter,
  125         .d_discard = nodiscard,
  126         .d_flag = D_TTY
  127 };
  128 
  129 const struct cdevsw pts_cdevsw = {
  130         .d_open = ptsopen,
  131         .d_close = ptsclose,
  132         .d_read = ptsread,
  133         .d_write = ptswrite,
  134         .d_ioctl = ptyioctl,
  135         .d_stop = ptsstop,
  136         .d_tty = ptytty,
  137         .d_poll = ptspoll,
  138         .d_mmap = nommap,
  139         .d_kqfilter = ttykqfilter,
  140         .d_discard = nodiscard,
  141         .d_flag = D_TTY
  142 };
  143 
  144 #if defined(pmax)
  145 /*
  146  * Used by arch/pmax/conf/majors.pmax, which needs a second copy as it
  147  * needs to map this stuff to two pairs of majors.
  148  */
  149 
  150 const struct cdevsw ptc_ultrix_cdevsw = {
  151         .d_open = ptcopen,
  152         .d_close = ptcclose,
  153         .d_read = ptcread,
  154         .d_write = ptcwrite,
  155         .d_ioctl = ptyioctl,
  156         .d_stop = nullstop,
  157         .d_tty = ptytty,
  158         .d_poll = ptcpoll,
  159         .d_mmap = nommap,
  160         .d_kqfilter = ptckqfilter,
  161         .d_discard = nodiscard,
  162         .d_flag = D_TTY
  163 };
  164 
  165 const struct cdevsw pts_ultrix_cdevsw = {
  166         .d_open = ptsopen,
  167         .d_close = ptsclose,
  168         .d_read = ptsread,
  169         .d_write = ptswrite,
  170         .d_ioctl = ptyioctl,
  171         .d_stop = ptsstop,
  172         .d_tty = ptytty,
  173         .d_poll = ptspoll,
  174         .d_mmap = nommap,
  175         .d_kqfilter = ttykqfilter,
  176         .d_discard = nodiscard,
  177         .d_flag = D_TTY
  178 };
  179 #endif /* defined(pmax) */
  180 
  181 /*
  182  * Check if a pty is free to use.
  183  */
  184 int
  185 pty_isfree(int minor, int lock)
  186 {
  187         struct pt_softc *pt = pt_softc[minor];
  188         if (lock)
  189                 mutex_enter(&pt_softc_mutex);
  190         minor = pt == NULL || pt->pt_tty == NULL ||
  191             pt->pt_tty->t_oproc == NULL;
  192         if (lock)
  193                 mutex_exit(&pt_softc_mutex);
  194         return minor;
  195 }
  196 
  197 /*
  198  * Allocate and zero array of nelem elements.
  199  */
  200 static struct pt_softc **
  201 ptyarralloc(int nelem)
  202 {
  203         struct pt_softc **pt;
  204         nelem += 10;
  205         pt = kmem_zalloc(nelem * sizeof(*pt), KM_SLEEP);
  206         return pt;
  207 }
  208 
  209 static void
  210 ptyarrfree(struct pt_softc **pt, int nelem)
  211 {
  212 
  213         nelem += 10;
  214         kmem_free(pt, nelem * sizeof(*pt));
  215 }
  216 
  217 /*
  218  * Check if the minor is correct and ensure necessary structures
  219  * are properly allocated.
  220  */
  221 int
  222 pty_check(int ptn)
  223 {
  224         struct pt_softc *pti;
  225 
  226         if (ptn >= npty) {
  227                 struct pt_softc **newpt, **oldpt;
  228                 int newnpty;
  229                 int oldnpty;
  230 
  231                 /* check if the requested pty can be granted */
  232                 if (ptn >= maxptys) {
  233             limit_reached:
  234                         tablefull("pty", "increase kern.maxptys");
  235                         return ENXIO;
  236                 }
  237 
  238                 /* Allocate a larger pty array */
  239                 for (newnpty = npty; newnpty <= ptn;)
  240                         newnpty *= 2;
  241                 if (newnpty > maxptys)
  242                         newnpty = maxptys;
  243                 newpt = ptyarralloc(newnpty);
  244 
  245                 /*
  246                  * Now grab the pty array mutex - we need to ensure
  247                  * that the pty array is consistent while copying its
  248                  * content to newly allocated, larger space; we also
  249                  * need to be safe against pty_maxptys().
  250                  */
  251                 mutex_enter(&pt_softc_mutex);
  252 
  253                 if (newnpty >= maxptys) {
  254                         /* limit cut away beneath us... */
  255                         if (ptn >= maxptys) {
  256                                 mutex_exit(&pt_softc_mutex);
  257                                 ptyarrfree(newpt, newnpty);
  258                                 goto limit_reached;
  259                         }
  260                         newnpty = maxptys;
  261                 }
  262 
  263                 /*
  264                  * If the pty array was not enlarged while we were waiting
  265                  * for mutex, copy current contents of pt_softc[] to newly
  266                  * allocated array and start using the new bigger array.
  267                  */
  268                 if (newnpty > npty) {
  269                         memcpy(newpt, pt_softc, npty*sizeof(struct pt_softc *));
  270                         oldpt = pt_softc;
  271                         oldnpty = npty;
  272                         pt_softc = newpt;
  273                         npty = newnpty;
  274                 } else {
  275                         /* was enlarged when waited for lock, free new space */
  276                         oldpt = newpt;
  277                         oldnpty = newnpty;
  278                 }
  279 
  280                 mutex_exit(&pt_softc_mutex);
  281                 ptyarrfree(oldpt, oldnpty);
  282         }
  283 
  284         /*
  285          * If the entry is not yet allocated, allocate one. The mutex is
  286          * needed so that the state of pt_softc[] array is consistant
  287          * in case it has been lengthened above.
  288          */
  289         if (!pt_softc[ptn]) {
  290                 pti = kmem_zalloc(sizeof(*pti), KM_SLEEP);
  291 
  292                 selinit(&pti->pt_selr);
  293                 selinit(&pti->pt_selw);
  294                 pti->pt_tty = tty_alloc();
  295 
  296                 mutex_enter(&pt_softc_mutex);
  297 
  298                 /*
  299                  * Check the entry again - it might have been
  300                  * added while we were waiting for mutex.
  301                  */
  302                 if (pt_softc[ptn]) {
  303                         mutex_exit(&pt_softc_mutex);
  304                         tty_free(pti->pt_tty);
  305                         seldestroy(&pti->pt_selr);
  306                         seldestroy(&pti->pt_selw);
  307                         kmem_free(pti, sizeof(*pti));
  308                         return 0;
  309                 }
  310                 tty_attach(pti->pt_tty);
  311                 pt_softc[ptn] = pti;
  312 
  313                 mutex_exit(&pt_softc_mutex);
  314         }
  315 
  316         return 0;
  317 }
  318 
  319 /*
  320  * Set maxpty in thread-safe way. Returns 0 in case of error, otherwise
  321  * new value of maxptys.
  322  */
  323 int
  324 pty_maxptys(int newmax, int set)
  325 {
  326         if (!set)
  327                 return maxptys;
  328 
  329         /*
  330          * We have to grab the pt_softc lock, so that we would pick correct
  331          * value of npty (might be modified in pty_check()).
  332          */
  333         mutex_enter(&pt_softc_mutex);
  334 
  335         /*
  336          * The value cannot be set to value lower than the highest pty
  337          * number ever allocated.
  338          */
  339         if (newmax >= npty)
  340                 maxptys = newmax;
  341         else
  342                 newmax = 0;
  343 
  344         mutex_exit(&pt_softc_mutex);
  345 
  346         return newmax;
  347 }
  348 
  349 /*
  350  * Establish n (or default if n is 1) ptys in the system.
  351  */
  352 void
  353 ptyattach(int n)
  354 {
  355 
  356         mutex_init(&pt_softc_mutex, MUTEX_DEFAULT, IPL_NONE);
  357 
  358         /* maybe should allow 0 => none? */
  359         if (n <= 1)
  360                 n = DEFAULT_NPTYS;
  361         pt_softc = ptyarralloc(n);
  362         npty = n;
  363 #ifndef NO_DEV_PTM
  364         ptmattach(1);
  365 #endif
  366 }
  367 
  368 /*ARGSUSED*/
  369 int
  370 ptsopen(dev_t dev, int flag, int devtype, struct lwp *l)
  371 {
  372         struct pt_softc *pti;
  373         struct tty *tp;
  374         int error;
  375         int ptn = minor(dev);
  376 
  377         if ((error = pty_check(ptn)) != 0)
  378                 return error;
  379 
  380         mutex_spin_enter(&tty_lock);
  381         pti = pt_softc[ptn];
  382         tp = pti->pt_tty;
  383         if (!ISSET(tp->t_state, TS_ISOPEN)) {
  384                 tp->t_dev = dev;
  385                 ttychars(tp);           /* Set up default chars */
  386                 tp->t_iflag = TTYDEF_IFLAG;
  387                 tp->t_oflag = TTYDEF_OFLAG;
  388                 tp->t_lflag = TTYDEF_LFLAG;
  389                 tp->t_cflag = TTYDEF_CFLAG;
  390                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
  391                 ttsetwater(tp);         /* would be done in xxparam() */
  392         } else if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN,
  393             tp) != 0) {
  394                 mutex_spin_exit(&tty_lock);
  395                 return EBUSY;
  396         }
  397         if (tp->t_oproc)                        /* Ctrlr still around. */
  398                 SET(tp->t_state, TS_CARR_ON);
  399         if (!ISSET(flag, O_NONBLOCK)) {
  400                 while (!ISSET(tp->t_state, TS_CARR_ON)) {
  401                         tp->t_wopen++;
  402                         error = ttysleep(tp, &tp->t_rawcv, true, 0);
  403                         tp->t_wopen--;
  404                         if (error != 0) {
  405                                 mutex_spin_exit(&tty_lock);
  406                                 return error;
  407                         }
  408                 }
  409         }
  410         mutex_spin_exit(&tty_lock);
  411         error = (*tp->t_linesw->l_open)(dev, tp);
  412         ptcwakeup(tp, FREAD|FWRITE);
  413         return error;
  414 }
  415 
  416 int
  417 ptsclose(dev_t dev, int flag, int mode, struct lwp *l)
  418 {
  419         struct pt_softc *pti = pt_softc[minor(dev)];
  420         struct tty *tp = pti->pt_tty;
  421         int error;
  422 
  423         error = (*tp->t_linesw->l_close)(tp, flag);
  424         error |= ttyclose(tp);
  425         ptcwakeup(tp, FREAD|FWRITE);
  426         return error;
  427 }
  428 
  429 int
  430 ptsread(dev_t dev, struct uio *uio, int flag)
  431 {
  432         struct proc *p = curproc;
  433         struct pt_softc *pti = pt_softc[minor(dev)];
  434         struct tty *tp = pti->pt_tty;
  435         int error = 0;
  436         int cc, c;
  437 
  438 again:
  439         if (pti->pt_flags & PF_REMOTE) {
  440                 mutex_spin_enter(&tty_lock);
  441                 while (isbackground(p, tp)) {   /* XXXSMP */
  442                         if (sigismasked(curlwp, SIGTTIN) ||
  443                             p->p_pgrp->pg_jobc == 0 ||
  444                             p->p_lflag & PL_PPWAIT) {
  445                                 mutex_spin_exit(&tty_lock);
  446                                 return EIO;
  447                         }
  448                         ttysig(tp, TTYSIG_PG1, SIGTTIN);
  449                         error = ttypause(tp, hz);
  450                         if (error != 0) {
  451                                 mutex_spin_exit(&tty_lock);
  452                                 return error;
  453                         }
  454                 }
  455                 if (tp->t_canq.c_cc == 0) {
  456                         if (flag & IO_NDELAY) {
  457                                 mutex_spin_exit(&tty_lock);
  458                                 return EWOULDBLOCK;
  459                         }
  460                         error = ttysleep(tp, &tp->t_cancv, true, 0);
  461                         mutex_spin_exit(&tty_lock);
  462                         if (error != 0)
  463                                 return error;
  464                         goto again;
  465                 }
  466                 while(error == 0 && tp->t_canq.c_cc > 1 && uio->uio_resid > 0) {
  467                         c = getc(&tp->t_canq);
  468                         mutex_spin_exit(&tty_lock);
  469                         error = ureadc(c, uio);
  470                         mutex_spin_enter(&tty_lock);
  471                         /* Re-check terminal state here? */
  472                 }
  473                 if (tp->t_canq.c_cc == 1)
  474                         (void) getc(&tp->t_canq);
  475                 cc = tp->t_canq.c_cc;
  476                 mutex_spin_exit(&tty_lock);
  477                 if (cc)
  478                         return error;
  479         } else if (tp->t_oproc)
  480                 error = (*tp->t_linesw->l_read)(tp, uio, flag);
  481         ptcwakeup(tp, FWRITE);
  482         return error;
  483 }
  484 
  485 /*
  486  * Write to pseudo-tty.
  487  * Wakeups of controlling tty will happen
  488  * indirectly, when tty driver calls ptsstart.
  489  */
  490 int
  491 ptswrite(dev_t dev, struct uio *uio, int flag)
  492 {
  493         struct pt_softc *pti = pt_softc[minor(dev)];
  494         struct tty *tp = pti->pt_tty;
  495 
  496         if (tp->t_oproc == NULL)
  497                 return EIO;
  498         return (*tp->t_linesw->l_write)(tp, uio, flag);
  499 }
  500 
  501 /*
  502  * Poll pseudo-tty.
  503  */
  504 int
  505 ptspoll(dev_t dev, int events, struct lwp *l)
  506 {
  507         struct pt_softc *pti = pt_softc[minor(dev)];
  508         struct tty *tp = pti->pt_tty;
  509 
  510         if (tp->t_oproc == NULL)
  511                 return POLLHUP;
  512 
  513         return (*tp->t_linesw->l_poll)(tp, events, l);
  514 }
  515 
  516 /*
  517  * Start output on pseudo-tty.
  518  * Wake up process polling or sleeping for input from controlling tty.
  519  */
  520 void
  521 ptsstart(struct tty *tp)
  522 {
  523         struct pt_softc *pti;
  524 
  525         KASSERT(tp->t_dev != NODEV);
  526         pti = pt_softc[minor(tp->t_dev)];
  527 
  528         KASSERT(mutex_owned(&tty_lock));
  529 
  530         if (ISSET(tp->t_state, TS_TTSTOP))
  531                 return;
  532         if (pti->pt_flags & PF_STOPPED) {
  533                 pti->pt_flags &= ~PF_STOPPED;
  534                 pti->pt_send = TIOCPKT_START;
  535         }
  536 
  537         selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
  538         cv_broadcast(&tp->t_outcvf);
  539 }
  540 
  541 /*
  542  * Stop output.
  543  */
  544 void
  545 ptsstop(struct tty *tp, int flush)
  546 {
  547         struct pt_softc *pti;
  548 
  549         KASSERT(tp->t_dev != NODEV);
  550         pti = pt_softc[minor(tp->t_dev)];
  551 
  552         KASSERT(mutex_owned(&tty_lock));
  553 
  554         /* note: FLUSHREAD and FLUSHWRITE already ok */
  555         CTASSERT(TIOCPKT_FLUSHREAD == FREAD);
  556         CTASSERT(TIOCPKT_FLUSHWRITE == FWRITE);
  557         if (flush == 0) {
  558                 flush = TIOCPKT_STOP;
  559                 pti->pt_flags |= PF_STOPPED;
  560         } else
  561                 pti->pt_flags &= ~PF_STOPPED;
  562         pti->pt_send |= flush;
  563 
  564         /* change of perspective */
  565         if (flush & FREAD) {
  566                 selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
  567                 cv_broadcast(&tp->t_rawcvf);
  568         }
  569         if (flush & FWRITE) {
  570                 selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
  571                 cv_broadcast(&tp->t_outcvf);
  572         }
  573 }
  574 
  575 void
  576 ptcwakeup(struct tty *tp, int flag)
  577 {
  578         struct pt_softc *pti;
  579 
  580         if (tp->t_dev == NODEV)
  581                 return; /* client side not open yet */
  582 
  583         pti = pt_softc[minor(tp->t_dev)];
  584         KASSERT(pti != NULL);
  585 
  586         mutex_spin_enter(&tty_lock);
  587         if (flag & FREAD) {
  588                 selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
  589                 cv_broadcast(&tp->t_outcvf);
  590         }
  591         if (flag & FWRITE) {
  592                 selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
  593                 cv_broadcast(&tp->t_rawcvf);
  594         }
  595         mutex_spin_exit(&tty_lock);
  596 }
  597 
  598 /*ARGSUSED*/
  599 int
  600 ptcopen(dev_t dev, int flag, int devtype, struct lwp *l)
  601 {
  602         struct pt_softc *pti;
  603         struct tty *tp;
  604         int error;
  605         int ptn = minor(dev);
  606 
  607         if ((error = pty_check(ptn)) != 0)
  608                 return error;
  609 
  610         pti = pt_softc[ptn];
  611         tp = pti->pt_tty;
  612 
  613         mutex_spin_enter(&tty_lock);
  614         if (tp->t_oproc) {
  615                 mutex_spin_exit(&tty_lock);
  616                 return EIO;
  617         }
  618         tp->t_dev = dev;
  619         tp->t_oproc = ptsstart;
  620         mutex_spin_exit(&tty_lock);
  621         (void)(*tp->t_linesw->l_modem)(tp, 1);
  622         CLR(tp->t_lflag, EXTPROC);
  623         pti->pt_flags = 0;
  624         pti->pt_send = 0;
  625         pti->pt_ucntl = 0;
  626         return 0;
  627 }
  628 
  629 /*ARGSUSED*/
  630 int
  631 ptcclose(dev_t dev, int flag, int devtype, struct lwp *l)
  632 {
  633         struct pt_softc *pti = pt_softc[minor(dev)];
  634         struct tty *tp = pti->pt_tty;
  635 
  636         (void)(*tp->t_linesw->l_modem)(tp, 0);
  637         mutex_spin_enter(&tty_lock);
  638         CLR(tp->t_state, TS_CARR_ON);
  639         tp->t_oproc = NULL;             /* mark closed */
  640         mutex_spin_exit(&tty_lock);
  641         return 0;
  642 }
  643 
  644 int
  645 ptcread(dev_t dev, struct uio *uio, int flag)
  646 {
  647         struct pt_softc *pti = pt_softc[minor(dev)];
  648         struct tty *tp = pti->pt_tty;
  649         u_char bf[BUFSIZ];
  650         int error = 0, cc;
  651         int c;
  652 
  653         if (uio->uio_resid <= 0)
  654                 return EINVAL;
  655 
  656         /*
  657          * We want to block until the slave
  658          * is open, and there's something to read;
  659          * but if we lost the slave or we're NBIO,
  660          * then return the appropriate error instead.
  661          */
  662         mutex_spin_enter(&tty_lock);
  663         for (;;) {
  664                 if (ISSET(tp->t_state, TS_ISOPEN)) {
  665                         if (pti->pt_flags & PF_PKT && (c = pti->pt_send)) {
  666                                 pti->pt_send = 0;
  667                                 mutex_spin_exit(&tty_lock);
  668                                 error = ureadc(c, uio);
  669                                 if (error != 0)
  670                                         return error;
  671                                 /*
  672                                  * Since we don't have the tty locked, there's
  673                                  * a risk of messing up `t_termios'. This is
  674                                  * relevant only if the tty got closed and then
  675                                  * opened again while we were out uiomoving.
  676                                  */
  677                                 if (c & TIOCPKT_IOCTL) {
  678                                         cc = uimin(uio->uio_resid,
  679                                                 sizeof(tp->t_termios));
  680                                         uiomove((void *) &tp->t_termios,
  681                                                 cc, uio);
  682                                 }
  683                                 return 0;
  684                         }
  685                         if (pti->pt_flags & PF_UCNTL && (c = pti->pt_ucntl)) {
  686                                 pti->pt_ucntl = 0;
  687                                 mutex_spin_exit(&tty_lock);
  688                                 error = ureadc(c, uio);
  689                                 if (error != 0)
  690                                         return error;
  691                                 return 0;
  692                         }
  693                         if (tp->t_outq.c_cc && !ISSET(tp->t_state, TS_TTSTOP))
  694                                 break;
  695                 }
  696                 if (!ISSET(tp->t_state, TS_CARR_ON)) {
  697                         error = 0;      /* EOF */
  698                         goto out;
  699                 }
  700                 if (flag & IO_NDELAY) {
  701                         error = EWOULDBLOCK;
  702                         goto out;
  703                 }
  704                 error = cv_wait_sig(&tp->t_outcvf, &tty_lock);
  705                 if (error != 0)
  706                         goto out;
  707         }
  708 
  709         if (pti->pt_flags & (PF_PKT|PF_UCNTL)) {
  710                 mutex_spin_exit(&tty_lock);
  711                 error = ureadc(0, uio);
  712                 mutex_spin_enter(&tty_lock);
  713                 if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
  714                         error = EIO;
  715         }
  716         while (uio->uio_resid > 0 && error == 0) {
  717                 cc = q_to_b(&tp->t_outq, bf, uimin(uio->uio_resid, BUFSIZ));
  718                 if (cc <= 0)
  719                         break;
  720                 mutex_spin_exit(&tty_lock);
  721                 error = uiomove(bf, cc, uio);
  722                 mutex_spin_enter(&tty_lock);
  723                 if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
  724                         error = EIO;
  725         }
  726         ttypull(tp);
  727 out:
  728         mutex_spin_exit(&tty_lock);
  729         return error;
  730 }
  731 
  732 
  733 int
  734 ptcwrite(dev_t dev, struct uio *uio, int flag)
  735 {
  736         struct pt_softc *pti = pt_softc[minor(dev)];
  737         struct tty *tp = pti->pt_tty;
  738         u_char *cp = NULL;
  739         int cc = 0;
  740         u_char locbuf[BUFSIZ];
  741         int cnt = 0;
  742         int error = 0;
  743 
  744 again:
  745         mutex_spin_enter(&tty_lock);
  746         if (!ISSET(tp->t_state, TS_ISOPEN))
  747                 goto block;
  748         if (pti->pt_flags & PF_REMOTE) {
  749                 if (tp->t_canq.c_cc)
  750                         goto block;
  751                 while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG) {
  752                         if (cc == 0) {
  753                                 cc = uimin(uio->uio_resid, BUFSIZ);
  754                                 cc = uimin(cc, TTYHOG - tp->t_canq.c_cc);
  755                                 cp = locbuf;
  756                                 mutex_spin_exit(&tty_lock);
  757                                 error = uiomove(cp, cc, uio);
  758                                 if (error != 0)
  759                                         return error;
  760                                 mutex_spin_enter(&tty_lock);
  761                                 /* check again for safety */
  762                                 if (!ISSET(tp->t_state, TS_ISOPEN)) {
  763                                         /*
  764                                          * adjust for data copied in but not
  765                                          * written
  766                                          */
  767                                         uio->uio_resid += cc;
  768                                         error = EIO;
  769                                         goto out;
  770                                 }
  771                         }
  772                         if (cc) {
  773                                 cc = b_to_q(cp, cc, &tp->t_outq);
  774                                 if (cc > 0)
  775                                         goto block;
  776                         }
  777                 }
  778                 (void) putc(0, &tp->t_canq);
  779                 ttwakeup(tp);
  780                 cv_broadcast(&tp->t_cancv);
  781                 error = 0;
  782                 goto out;
  783         }
  784         while (uio->uio_resid > 0) {
  785                 if (cc == 0) {
  786                         cc = uimin(uio->uio_resid, BUFSIZ);
  787                         cp = locbuf;
  788                         mutex_spin_exit(&tty_lock);
  789                         error = uiomove(cp, cc, uio);
  790                         if (error != 0)
  791                                 return error;
  792                         mutex_spin_enter(&tty_lock);
  793                         /* check again for safety */
  794                         if (!ISSET(tp->t_state, TS_ISOPEN)) {
  795                                 /* adjust for data copied in but not written */
  796                                 uio->uio_resid += cc;
  797                                 error = EIO;
  798                                 goto out;
  799                         }
  800                 }
  801                 while (cc > 0) {
  802                         int used = tp->t_rawq.c_cc + tp->t_canq.c_cc;
  803                         int canon = ISSET(tp->t_lflag, ICANON) ? 1 : 0;
  804                         /*
  805                          * We need space for 2 characters if canonical
  806                          * because we might need to print ^C
  807                          */
  808                         if (used >= (TTYHOG - canon) &&
  809                            (tp->t_canq.c_cc > 0 || !canon)) {
  810                                 cv_broadcast(&tp->t_rawcv);
  811                                 goto block;
  812                         }
  813                         /*
  814                          * XXX - should change l_rint to be called with lock
  815                          *       see also tty.c:ttyinput_wlock()
  816                          */
  817                         mutex_spin_exit(&tty_lock);
  818                         (*tp->t_linesw->l_rint)(*cp++, tp);
  819                         mutex_spin_enter(&tty_lock);
  820                         cnt++;
  821                         cc--;
  822                 }
  823         }
  824         error = 0;
  825         goto out;
  826 
  827 block:
  828         /*
  829          * Come here to wait for slave to open, for space
  830          * in outq, or space in rawq.
  831          */
  832         if (!ISSET(tp->t_state, TS_CARR_ON)) {
  833                 /* adjust for data copied in but not written */
  834                 uio->uio_resid += cc;
  835                 error = EIO;
  836                 goto out;
  837         }
  838         if (flag & IO_NDELAY) {
  839                 /* adjust for data copied in but not written */
  840                 uio->uio_resid += cc;
  841                 error = cnt == 0 ? EWOULDBLOCK : 0;
  842                 goto out;
  843         }
  844         error = cv_wait_sig(&tp->t_rawcvf, &tty_lock);
  845         mutex_spin_exit(&tty_lock);
  846         if (error != 0) {
  847                 /* adjust for data copied in but not written */
  848                 uio->uio_resid += cc;
  849                 return error;
  850         }
  851         goto again;
  852 
  853 out:
  854         mutex_spin_exit(&tty_lock);
  855         return error;
  856 }
  857 
  858 int
  859 ptcpoll(dev_t dev, int events, struct lwp *l)
  860 {
  861         struct pt_softc *pti = pt_softc[minor(dev)];
  862         struct tty *tp = pti->pt_tty;
  863         int revents = 0;
  864 
  865         mutex_spin_enter(&tty_lock);
  866 
  867         if (events & (POLLIN | POLLRDNORM))
  868                 if (ISSET(tp->t_state, TS_ISOPEN) &&
  869                     ((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
  870                      ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
  871                      ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)))
  872                         revents |= events & (POLLIN | POLLRDNORM);
  873 
  874         if (events & (POLLOUT | POLLWRNORM))
  875                 if (ISSET(tp->t_state, TS_ISOPEN) &&
  876                     ((pti->pt_flags & PF_REMOTE) ?
  877                      (tp->t_canq.c_cc == 0) :
  878                      ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
  879                       (tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))))
  880                         revents |= events & (POLLOUT | POLLWRNORM);
  881 
  882         if (events & POLLHUP)
  883                 if (!ISSET(tp->t_state, TS_CARR_ON))
  884                         revents |= POLLHUP;
  885 
  886         if (revents == 0) {
  887                 if (events & (POLLIN | POLLHUP | POLLRDNORM))
  888                         selrecord(l, &pti->pt_selr);
  889 
  890                 if (events & (POLLOUT | POLLWRNORM))
  891                         selrecord(l, &pti->pt_selw);
  892         }
  893 
  894         mutex_spin_exit(&tty_lock);
  895 
  896         return revents;
  897 }
  898 
  899 static void
  900 filt_ptcrdetach(struct knote *kn)
  901 {
  902         struct pt_softc *pti;
  903 
  904         pti = kn->kn_hook;
  905 
  906         mutex_spin_enter(&tty_lock);
  907         selremove_knote(&pti->pt_selr, kn);
  908         mutex_spin_exit(&tty_lock);
  909 }
  910 
  911 static int
  912 filt_ptcread(struct knote *kn, long hint)
  913 {
  914         struct pt_softc *pti;
  915         struct tty      *tp;
  916         int canread;
  917 
  918         pti = kn->kn_hook;
  919         tp = pti->pt_tty;
  920 
  921         if ((hint & NOTE_SUBMIT) == 0) {
  922                 mutex_spin_enter(&tty_lock);
  923         }
  924 
  925         canread = (ISSET(tp->t_state, TS_ISOPEN) &&
  926                     ((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
  927                      ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
  928                      ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)));
  929 
  930         if (canread) {
  931                 /*
  932                  * c_cc is number of characters after output post-processing;
  933                  * the amount of data actually read(2) depends on
  934                  * setting of input flags for the terminal.
  935                  */
  936                 kn->kn_data = tp->t_outq.c_cc;
  937                 if (((pti->pt_flags & PF_PKT) && pti->pt_send) ||
  938                     ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
  939                         kn->kn_data++;
  940         }
  941         if (!ISSET(tp->t_state, TS_CARR_ON)) {
  942                 knote_set_eof(kn, 0);
  943                 canread = 1;
  944         }
  945 
  946         if ((hint & NOTE_SUBMIT) == 0) {
  947                 mutex_spin_exit(&tty_lock);
  948         }
  949 
  950         return canread;
  951 }
  952 
  953 static void
  954 filt_ptcwdetach(struct knote *kn)
  955 {
  956         struct pt_softc *pti;
  957 
  958         pti = kn->kn_hook;
  959 
  960         mutex_spin_enter(&tty_lock);
  961         selremove_knote(&pti->pt_selw, kn);
  962         mutex_spin_exit(&tty_lock);
  963 }
  964 
  965 static int
  966 filt_ptcwrite(struct knote *kn, long hint)
  967 {
  968         struct pt_softc *pti;
  969         struct tty      *tp;
  970         int canwrite;
  971         int nwrite;
  972 
  973         pti = kn->kn_hook;
  974         tp = pti->pt_tty;
  975 
  976         if ((hint & NOTE_SUBMIT) == 0) {
  977                 mutex_spin_enter(&tty_lock);
  978         }
  979 
  980         canwrite = (ISSET(tp->t_state, TS_ISOPEN) &&
  981                     ((pti->pt_flags & PF_REMOTE) ?
  982                      (tp->t_canq.c_cc == 0) :
  983                      ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
  984                       (tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))));
  985 
  986         if (canwrite) {
  987                 if (pti->pt_flags & PF_REMOTE)
  988                         nwrite = tp->t_canq.c_cn;
  989                 else {
  990                         /* this is guaranteed to be > 0 due to above check */
  991                         nwrite = tp->t_canq.c_cn
  992                                 - (tp->t_rawq.c_cc + tp->t_canq.c_cc);
  993                 }
  994                 kn->kn_data = nwrite;
  995         }
  996 
  997         if ((hint & NOTE_SUBMIT) == 0) {
  998                 mutex_spin_exit(&tty_lock);
  999         }
 1000 
 1001         return canwrite;
 1002 }
 1003 
 1004 static const struct filterops ptcread_filtops = {
 1005         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 1006         .f_attach = NULL,
 1007         .f_detach = filt_ptcrdetach,
 1008         .f_event = filt_ptcread,
 1009 };
 1010 
 1011 static const struct filterops ptcwrite_filtops = {
 1012         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 1013         .f_attach = NULL,
 1014         .f_detach = filt_ptcwdetach,
 1015         .f_event = filt_ptcwrite,
 1016 };
 1017 
 1018 int
 1019 ptckqfilter(dev_t dev, struct knote *kn)
 1020 {
 1021         struct pt_softc *pti = pt_softc[minor(dev)];
 1022         struct selinfo  *sip;
 1023 
 1024         switch (kn->kn_filter) {
 1025         case EVFILT_READ:
 1026                 sip = &pti->pt_selr;
 1027                 kn->kn_fop = &ptcread_filtops;
 1028                 break;
 1029         case EVFILT_WRITE:
 1030                 sip = &pti->pt_selw;
 1031                 kn->kn_fop = &ptcwrite_filtops;
 1032                 break;
 1033         default:
 1034                 return EINVAL;
 1035         }
 1036 
 1037         kn->kn_hook = pti;
 1038 
 1039         mutex_spin_enter(&tty_lock);
 1040         selrecord_knote(sip, kn);
 1041         mutex_spin_exit(&tty_lock);
 1042 
 1043         return 0;
 1044 }
 1045 
 1046 struct tty *
 1047 ptytty(dev_t dev)
 1048 {
 1049         struct pt_softc *pti = pt_softc[minor(dev)];
 1050         struct tty *tp = pti->pt_tty;
 1051 
 1052         return tp;
 1053 }
 1054 
 1055 /*ARGSUSED*/
 1056 int
 1057 ptyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
 1058 {
 1059         struct pt_softc *pti = pt_softc[minor(dev)];
 1060         struct tty *tp = pti->pt_tty;
 1061         const struct cdevsw *cdev;
 1062         u_char *cc = tp->t_cc;
 1063         int stop, error, sig;
 1064 #ifndef NO_DEV_PTM
 1065         struct mount *mp;
 1066 #endif
 1067 
 1068         /*
 1069          * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
 1070          * ttywflush(tp) will hang if there are characters in the outq.
 1071          */
 1072         if (cmd == TIOCEXT) {
 1073                 /*
 1074                  * When the EXTPROC bit is being toggled, we need
 1075                  * to send an TIOCPKT_IOCTL if the packet driver
 1076                  * is turned on.
 1077                  */
 1078                 if (*(int *)data) {
 1079                         if (pti->pt_flags & PF_PKT) {
 1080                                 pti->pt_send |= TIOCPKT_IOCTL;
 1081                                 ptcwakeup(tp, FREAD);
 1082                         }
 1083                         SET(tp->t_lflag, EXTPROC);
 1084                 } else {
 1085                         if (ISSET(tp->t_lflag, EXTPROC) &&
 1086                             (pti->pt_flags & PF_PKT)) {
 1087                                 pti->pt_send |= TIOCPKT_IOCTL;
 1088                                 ptcwakeup(tp, FREAD);
 1089                         }
 1090                         CLR(tp->t_lflag, EXTPROC);
 1091                 }
 1092                 return(0);
 1093         }
 1094 
 1095 #ifndef NO_DEV_PTM
 1096         /* Allow getting the name from either the master or the slave */
 1097         if (cmd == TIOCPTSNAME) {
 1098                 if ((error = pty_getmp(l, &mp)) != 0)
 1099                         return error;
 1100                 return pty_fill_ptmget(l, dev, -1, -1, data, mp);
 1101         }
 1102 #endif
 1103 
 1104         cdev = cdevsw_lookup(dev);
 1105         if (cdev != NULL && cdev->d_open == ptcopen)
 1106                 switch (cmd) {
 1107 #ifndef NO_DEV_PTM
 1108                 case TIOCGRANTPT:
 1109                         if ((error = pty_getmp(l, &mp)) != 0)
 1110                                 return error;
 1111                         return pty_grant_slave(l, dev, mp);
 1112 #endif
 1113 
 1114                 case TIOCGPGRP:
 1115                         /*
 1116                          * We avoid calling ttioctl on the controller since,
 1117                          * in that case, tp must be the controlling terminal.
 1118                          */
 1119                         *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1120                         return 0;
 1121 
 1122                 case TIOCPKT:
 1123                         if (*(int *)data) {
 1124                                 if (pti->pt_flags & PF_UCNTL)
 1125                                         return EINVAL;
 1126                                 pti->pt_flags |= PF_PKT;
 1127                         } else
 1128                                 pti->pt_flags &= ~PF_PKT;
 1129                         return 0;
 1130 
 1131                 case TIOCUCNTL:
 1132                         if (*(int *)data) {
 1133                                 if (pti->pt_flags & PF_PKT)
 1134                                         return EINVAL;
 1135                                 pti->pt_flags |= PF_UCNTL;
 1136                         } else
 1137                                 pti->pt_flags &= ~PF_UCNTL;
 1138                         return 0;
 1139 
 1140                 case TIOCREMOTE:
 1141                         if (*(int *)data)
 1142                                 pti->pt_flags |= PF_REMOTE;
 1143                         else
 1144                                 pti->pt_flags &= ~PF_REMOTE;
 1145                         mutex_spin_enter(&tty_lock);
 1146                         ttyflush(tp, FREAD|FWRITE);
 1147                         mutex_spin_exit(&tty_lock);
 1148                         return 0;
 1149 
 1150                 case TIOCSETP:
 1151                 case TIOCSETN:
 1152                 case TIOCSETD:
 1153                 case TIOCSETA:
 1154                 case TIOCSETAW:
 1155                 case TIOCSETAF:
 1156                         mutex_spin_enter(&tty_lock);
 1157                         ndflush(&tp->t_outq, tp->t_outq.c_cc);
 1158                         mutex_spin_exit(&tty_lock);
 1159                         break;
 1160 
 1161                 case TIOCSIG:
 1162                         sig = (int)(long)*(void **)data;
 1163                         if (sig <= 0 || sig >= NSIG)
 1164                                 return EINVAL;
 1165                         mutex_spin_enter(&tty_lock);
 1166                         if (!ISSET(tp->t_lflag, NOFLSH))
 1167                                 ttyflush(tp, FREAD|FWRITE);
 1168                         tp->t_state |= TS_SIGINFO;
 1169                         ttysig(tp, TTYSIG_PG1, sig);
 1170                         mutex_spin_exit(&tty_lock);
 1171                         return 0;
 1172 
 1173                 case FIONREAD:
 1174                         mutex_spin_enter(&tty_lock);
 1175                         *(int *)data = tp->t_outq.c_cc;
 1176                         mutex_spin_exit(&tty_lock);
 1177                         return 0;
 1178                 }
 1179 
 1180         error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
 1181         if (error == EPASSTHROUGH)
 1182                  error = ttioctl(tp, cmd, data, flag, l);
 1183         if (error == EPASSTHROUGH) {
 1184                 if (pti->pt_flags & PF_UCNTL &&
 1185                     (cmd & ~0xff) == UIOCCMD(0)) {
 1186                         if (cmd & 0xff) {
 1187                                 pti->pt_ucntl = (u_char)cmd;
 1188                                 ptcwakeup(tp, FREAD);
 1189                         }
 1190                         return 0;
 1191                 }
 1192         }
 1193         /*
 1194          * If external processing and packet mode send ioctl packet.
 1195          */
 1196         if (ISSET(tp->t_lflag, EXTPROC) && (pti->pt_flags & PF_PKT)) {
 1197                 switch(cmd) {
 1198                 case TIOCSETA:
 1199                 case TIOCSETAW:
 1200                 case TIOCSETAF:
 1201                 case TIOCSETP:
 1202                 case TIOCSETN:
 1203                 case TIOCSETC:
 1204                 case TIOCSLTC:
 1205                 case TIOCLBIS:
 1206                 case TIOCLBIC:
 1207                 case TIOCLSET:
 1208                         pti->pt_send |= TIOCPKT_IOCTL;
 1209                         ptcwakeup(tp, FREAD);
 1210                 default:
 1211                         break;
 1212                 }
 1213         }
 1214         stop = ISSET(tp->t_iflag, IXON) && CCEQ(cc[VSTOP], CTRL('s'))
 1215                 && CCEQ(cc[VSTART], CTRL('q'));
 1216         if (pti->pt_flags & PF_NOSTOP) {
 1217                 if (stop) {
 1218                         pti->pt_send &= ~TIOCPKT_NOSTOP;
 1219                         pti->pt_send |= TIOCPKT_DOSTOP;
 1220                         pti->pt_flags &= ~PF_NOSTOP;
 1221                         ptcwakeup(tp, FREAD);
 1222                 }
 1223         } else {
 1224                 if (!stop) {
 1225                         pti->pt_send &= ~TIOCPKT_DOSTOP;
 1226                         pti->pt_send |= TIOCPKT_NOSTOP;
 1227                         pti->pt_flags |= PF_NOSTOP;
 1228                         ptcwakeup(tp, FREAD);
 1229                 }
 1230         }
 1231         return error;
 1232 }
Cache object: 30d376dbe613c88cefd634a1be29c47c
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/tty_pty.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/tty_pty.c
