The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/tty.c

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    1 /*-
    2  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
    3  * All rights reserved.
    4  *
    5  * Portions of this software were developed under sponsorship from Snow
    6  * B.V., the Netherlands.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD: releng/8.1/sys/kern/tty.c 202553 2010-01-18 09:04:53Z ed $");
   32 
   33 #include "opt_compat.h"
   34 
   35 #include <sys/param.h>
   36 #include <sys/conf.h>
   37 #include <sys/cons.h>
   38 #include <sys/fcntl.h>
   39 #include <sys/file.h>
   40 #include <sys/filedesc.h>
   41 #include <sys/filio.h>
   42 #ifdef COMPAT_43TTY
   43 #include <sys/ioctl_compat.h>
   44 #endif /* COMPAT_43TTY */
   45 #include <sys/kernel.h>
   46 #include <sys/limits.h>
   47 #include <sys/malloc.h>
   48 #include <sys/mount.h>
   49 #include <sys/poll.h>
   50 #include <sys/priv.h>
   51 #include <sys/proc.h>
   52 #include <sys/serial.h>
   53 #include <sys/signal.h>
   54 #include <sys/stat.h>
   55 #include <sys/sx.h>
   56 #include <sys/sysctl.h>
   57 #include <sys/systm.h>
   58 #include <sys/tty.h>
   59 #include <sys/ttycom.h>
   60 #define TTYDEFCHARS
   61 #include <sys/ttydefaults.h>
   62 #undef TTYDEFCHARS
   63 #include <sys/ucred.h>
   64 #include <sys/vnode.h>
   65 
   66 #include <machine/stdarg.h>
   67 
   68 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
   69 
   70 static void tty_rel_free(struct tty *tp);
   71 
   72 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
   73 static struct sx tty_list_sx;
   74 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
   75 static unsigned int tty_list_count = 0;
   76 
   77 /* Character device of /dev/console. */
   78 static struct cdev      *dev_console;
   79 static const char       *dev_console_filename;
   80 
   81 /*
   82  * Flags that are supported and stored by this implementation.
   83  */
   84 #define TTYSUP_IFLAG    (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
   85                         INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
   86 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
   87 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
   88                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
   89                         FLUSHO|NOKERNINFO|NOFLSH)
   90 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
   91                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
   92                         CDSR_OFLOW|CCAR_OFLOW)
   93 
   94 #define TTY_CALLOUT(tp,d) ((d) != (tp)->t_dev && (d) != dev_console)
   95 
   96 /*
   97  * Set TTY buffer sizes.
   98  */
   99 
  100 #define TTYBUF_MAX      65536
  101 
  102 static void
  103 tty_watermarks(struct tty *tp)
  104 {
  105         size_t bs;
  106 
  107         /* Provide an input buffer for 0.2 seconds of data. */
  108         bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
  109         ttyinq_setsize(&tp->t_inq, tp, bs);
  110 
  111         /* Set low watermark at 10% (when 90% is available). */
  112         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
  113 
  114         /* Provide an ouput buffer for 0.2 seconds of data. */
  115         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
  116         ttyoutq_setsize(&tp->t_outq, tp, bs);
  117 
  118         /* Set low watermark at 10% (when 90% is available). */
  119         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
  120 }
  121 
  122 static int
  123 tty_drain(struct tty *tp)
  124 {
  125         int error;
  126 
  127         if (ttyhook_hashook(tp, getc_inject))
  128                 /* buffer is inaccessible */
  129                 return (0);
  130 
  131         while (ttyoutq_bytesused(&tp->t_outq) > 0) {
  132                 ttydevsw_outwakeup(tp);
  133                 /* Could be handled synchronously. */
  134                 if (ttyoutq_bytesused(&tp->t_outq) == 0)
  135                         return (0);
  136 
  137                 /* Wait for data to be drained. */
  138                 error = tty_wait(tp, &tp->t_outwait);
  139                 if (error)
  140                         return (error);
  141         }
  142 
  143         return (0);
  144 }
  145 
  146 /*
  147  * Though ttydev_enter() and ttydev_leave() seem to be related, they
  148  * don't have to be used together. ttydev_enter() is used by the cdev
  149  * operations to prevent an actual operation from being processed when
  150  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
  151  * and ttydev_close() to determine whether per-TTY data should be
  152  * deallocated.
  153  */
  154 
  155 static __inline int
  156 ttydev_enter(struct tty *tp)
  157 {
  158         tty_lock(tp);
  159 
  160         if (tty_gone(tp) || !tty_opened(tp)) {
  161                 /* Device is already gone. */
  162                 tty_unlock(tp);
  163                 return (ENXIO);
  164         }
  165 
  166         return (0);
  167 }
  168 
  169 static void
  170 ttydev_leave(struct tty *tp)
  171 {
  172         tty_lock_assert(tp, MA_OWNED);
  173 
  174         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
  175                 /* Device is still opened somewhere. */
  176                 tty_unlock(tp);
  177                 return;
  178         }
  179 
  180         tp->t_flags |= TF_OPENCLOSE;
  181 
  182         /* Stop asynchronous I/O. */
  183         funsetown(&tp->t_sigio);
  184 
  185         /* Remove console TTY. */
  186         if (constty == tp)
  187                 constty_clear();
  188 
  189         /* Drain any output. */
  190         MPASS((tp->t_flags & TF_STOPPED) == 0);
  191         if (!tty_gone(tp))
  192                 tty_drain(tp);
  193 
  194         ttydisc_close(tp);
  195 
  196         /* Destroy associated buffers already. */
  197         ttyinq_free(&tp->t_inq);
  198         tp->t_inlow = 0;
  199         ttyoutq_free(&tp->t_outq);
  200         tp->t_outlow = 0;
  201 
  202         knlist_clear(&tp->t_inpoll.si_note, 1);
  203         knlist_clear(&tp->t_outpoll.si_note, 1);
  204 
  205         if (!tty_gone(tp))
  206                 ttydevsw_close(tp);
  207 
  208         tp->t_flags &= ~TF_OPENCLOSE;
  209         cv_broadcast(&tp->t_dcdwait);
  210         tty_rel_free(tp);
  211 }
  212 
  213 /*
  214  * Operations that are exposed through the character device in /dev.
  215  */
  216 static int
  217 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  218 {
  219         struct tty *tp = dev->si_drv1;
  220         int error = 0;
  221 
  222         tty_lock(tp);
  223         if (tty_gone(tp)) {
  224                 /* Device is already gone. */
  225                 tty_unlock(tp);
  226                 return (ENXIO);
  227         }
  228 
  229         /*
  230          * Block when other processes are currently opening or closing
  231          * the TTY.
  232          */
  233         while (tp->t_flags & TF_OPENCLOSE) {
  234                 error = tty_wait(tp, &tp->t_dcdwait);
  235                 if (error != 0) {
  236                         tty_unlock(tp);
  237                         return (error);
  238                 }
  239         }
  240         tp->t_flags |= TF_OPENCLOSE;
  241 
  242         /*
  243          * Make sure the "tty" and "cua" device cannot be opened at the
  244          * same time.
  245          */
  246         if (TTY_CALLOUT(tp, dev)) {
  247                 if (tp->t_flags & TF_OPENED_IN) {
  248                         error = EBUSY;
  249                         goto done;
  250                 }
  251         } else {
  252                 if (tp->t_flags & TF_OPENED_OUT) {
  253                         error = EBUSY;
  254                         goto done;
  255                 }
  256         }
  257 
  258         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
  259                 error = EBUSY;
  260                 goto done;
  261         }
  262 
  263         if (!tty_opened(tp)) {
  264                 /* Set proper termios flags. */
  265                 if (TTY_CALLOUT(tp, dev)) {
  266                         tp->t_termios = tp->t_termios_init_out;
  267                 } else {
  268                         tp->t_termios = tp->t_termios_init_in;
  269                 }
  270                 ttydevsw_param(tp, &tp->t_termios);
  271 
  272                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
  273 
  274                 error = ttydevsw_open(tp);
  275                 if (error != 0)
  276                         goto done;
  277 
  278                 ttydisc_open(tp);
  279                 tty_watermarks(tp);
  280         }
  281 
  282         /* Wait for Carrier Detect. */
  283         if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
  284             (tp->t_termios.c_cflag & CLOCAL) == 0) {
  285                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
  286                         error = tty_wait(tp, &tp->t_dcdwait);
  287                         if (error != 0)
  288                                 goto done;
  289                 }
  290         }
  291 
  292         if (dev == dev_console)
  293                 tp->t_flags |= TF_OPENED_CONS;
  294         else if (TTY_CALLOUT(tp, dev))
  295                 tp->t_flags |= TF_OPENED_OUT;
  296         else
  297                 tp->t_flags |= TF_OPENED_IN;
  298 
  299 done:   tp->t_flags &= ~TF_OPENCLOSE;
  300         cv_broadcast(&tp->t_dcdwait);
  301         ttydev_leave(tp);
  302 
  303         return (error);
  304 }
  305 
  306 static int
  307 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
  308 {
  309         struct tty *tp = dev->si_drv1;
  310 
  311         tty_lock(tp);
  312 
  313         /*
  314          * Don't actually close the device if it is being used as the
  315          * console.
  316          */
  317         MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
  318         if (dev == dev_console)
  319                 tp->t_flags &= ~TF_OPENED_CONS;
  320         else
  321                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
  322 
  323         if (tp->t_flags & TF_OPENED) {
  324                 tty_unlock(tp);
  325                 return (0);
  326         }
  327 
  328         /*
  329          * This can only be called once. The callin and the callout
  330          * devices cannot be opened at the same time.
  331          */
  332         tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
  333 
  334         /* Properly wake up threads that are stuck - revoke(). */
  335         tp->t_revokecnt++;
  336         tty_wakeup(tp, FREAD|FWRITE);
  337         cv_broadcast(&tp->t_bgwait);
  338         cv_broadcast(&tp->t_dcdwait);
  339 
  340         ttydev_leave(tp);
  341 
  342         return (0);
  343 }
  344 
  345 static __inline int
  346 tty_is_ctty(struct tty *tp, struct proc *p)
  347 {
  348         tty_lock_assert(tp, MA_OWNED);
  349 
  350         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
  351 }
  352 
  353 static int
  354 tty_wait_background(struct tty *tp, struct thread *td, int sig)
  355 {
  356         struct proc *p = td->td_proc;
  357         struct pgrp *pg;
  358         ksiginfo_t ksi;
  359         int error;
  360 
  361         MPASS(sig == SIGTTIN || sig == SIGTTOU);
  362         tty_lock_assert(tp, MA_OWNED);
  363 
  364         for (;;) {
  365                 PROC_LOCK(p);
  366                 /*
  367                  * The process should only sleep, when:
  368                  * - This terminal is the controling terminal
  369                  * - Its process group is not the foreground process
  370                  *   group
  371                  * - The parent process isn't waiting for the child to
  372                  *   exit
  373                  * - the signal to send to the process isn't masked
  374                  */
  375                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
  376                         /* Allow the action to happen. */
  377                         PROC_UNLOCK(p);
  378                         return (0);
  379                 }
  380 
  381                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
  382                     SIGISMEMBER(td->td_sigmask, sig)) {
  383                         /* Only allow them in write()/ioctl(). */
  384                         PROC_UNLOCK(p);
  385                         return (sig == SIGTTOU ? 0 : EIO);
  386                 }
  387 
  388                 pg = p->p_pgrp;
  389                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
  390                         /* Don't allow the action to happen. */
  391                         PROC_UNLOCK(p);
  392                         return (EIO);
  393                 }
  394                 PROC_UNLOCK(p);
  395 
  396                 /*
  397                  * Send the signal and sleep until we're the new
  398                  * foreground process group.
  399                  */
  400                 if (sig != 0) {
  401                         ksiginfo_init(&ksi);
  402                         ksi.ksi_code = SI_KERNEL;
  403                         ksi.ksi_signo = sig;
  404                         sig = 0;
  405                 }
  406                 PGRP_LOCK(pg);
  407                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
  408                 PGRP_UNLOCK(pg);
  409 
  410                 error = tty_wait(tp, &tp->t_bgwait);
  411                 if (error)
  412                         return (error);
  413         }
  414 }
  415 
  416 static int
  417 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
  418 {
  419         struct tty *tp = dev->si_drv1;
  420         int error;
  421 
  422         error = ttydev_enter(tp);
  423         if (error)
  424                 goto done;
  425 
  426         error = tty_wait_background(tp, curthread, SIGTTIN);
  427         if (error) {
  428                 tty_unlock(tp);
  429                 goto done;
  430         }
  431 
  432         error = ttydisc_read(tp, uio, ioflag);
  433         tty_unlock(tp);
  434 
  435         /*
  436          * The read() call should not throw an error when the device is
  437          * being destroyed. Silently convert it to an EOF.
  438          */
  439 done:   if (error == ENXIO)
  440                 error = 0;
  441         return (error);
  442 }
  443 
  444 static int
  445 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  446 {
  447         struct tty *tp = dev->si_drv1;
  448         int error;
  449 
  450         error = ttydev_enter(tp);
  451         if (error)
  452                 return (error);
  453 
  454         if (tp->t_termios.c_lflag & TOSTOP) {
  455                 error = tty_wait_background(tp, curthread, SIGTTOU);
  456                 if (error)
  457                         goto done;
  458         }
  459 
  460         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  461                 /* Allow non-blocking writes to bypass serialization. */
  462                 error = ttydisc_write(tp, uio, ioflag);
  463         } else {
  464                 /* Serialize write() calls. */
  465                 while (tp->t_flags & TF_BUSY_OUT) {
  466                         error = tty_wait(tp, &tp->t_outserwait);
  467                         if (error)
  468                                 goto done;
  469                 }
  470  
  471                 tp->t_flags |= TF_BUSY_OUT;
  472                 error = ttydisc_write(tp, uio, ioflag);
  473                 tp->t_flags &= ~TF_BUSY_OUT;
  474                 cv_signal(&tp->t_outserwait);
  475         }
  476 
  477 done:   tty_unlock(tp);
  478         return (error);
  479 }
  480 
  481 static int
  482 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  483     struct thread *td)
  484 {
  485         struct tty *tp = dev->si_drv1;
  486         int error;
  487 
  488         error = ttydev_enter(tp);
  489         if (error)
  490                 return (error);
  491 
  492         switch (cmd) {
  493         case TIOCCBRK:
  494         case TIOCCONS:
  495         case TIOCDRAIN:
  496         case TIOCEXCL:
  497         case TIOCFLUSH:
  498         case TIOCNXCL:
  499         case TIOCSBRK:
  500         case TIOCSCTTY:
  501         case TIOCSETA:
  502         case TIOCSETAF:
  503         case TIOCSETAW:
  504         case TIOCSPGRP:
  505         case TIOCSTART:
  506         case TIOCSTAT:
  507         case TIOCSTI:
  508         case TIOCSTOP:
  509         case TIOCSWINSZ:
  510 #if 0
  511         case TIOCSDRAINWAIT:
  512         case TIOCSETD:
  513 #endif
  514 #ifdef COMPAT_43TTY
  515         case  TIOCLBIC:
  516         case  TIOCLBIS:
  517         case  TIOCLSET:
  518         case  TIOCSETC:
  519         case OTIOCSETD:
  520         case  TIOCSETN:
  521         case  TIOCSETP:
  522         case  TIOCSLTC:
  523 #endif /* COMPAT_43TTY */
  524                 /*
  525                  * If the ioctl() causes the TTY to be modified, let it
  526                  * wait in the background.
  527                  */
  528                 error = tty_wait_background(tp, curthread, SIGTTOU);
  529                 if (error)
  530                         goto done;
  531         }
  532 
  533         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  534                 struct termios *old = &tp->t_termios;
  535                 struct termios *new = (struct termios *)data;
  536                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  537                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  538                 int cc;
  539 
  540                 /*
  541                  * Lock state devices.  Just overwrite the values of the
  542                  * commands that are currently in use.
  543                  */
  544                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  545                     (new->c_iflag & ~lock->c_iflag);
  546                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  547                     (new->c_oflag & ~lock->c_oflag);
  548                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  549                     (new->c_cflag & ~lock->c_cflag);
  550                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  551                     (new->c_lflag & ~lock->c_lflag);
  552                 for (cc = 0; cc < NCCS; ++cc)
  553                         if (lock->c_cc[cc])
  554                                 new->c_cc[cc] = old->c_cc[cc];
  555                 if (lock->c_ispeed)
  556                         new->c_ispeed = old->c_ispeed;
  557                 if (lock->c_ospeed)
  558                         new->c_ospeed = old->c_ospeed;
  559         }
  560 
  561         error = tty_ioctl(tp, cmd, data, fflag, td);
  562 done:   tty_unlock(tp);
  563 
  564         return (error);
  565 }
  566 
  567 static int
  568 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  569 {
  570         struct tty *tp = dev->si_drv1;
  571         int error, revents = 0;
  572 
  573         error = ttydev_enter(tp);
  574         if (error)
  575                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  576 
  577         if (events & (POLLIN|POLLRDNORM)) {
  578                 /* See if we can read something. */
  579                 if (ttydisc_read_poll(tp) > 0)
  580                         revents |= events & (POLLIN|POLLRDNORM);
  581         }
  582 
  583         if (tp->t_flags & TF_ZOMBIE) {
  584                 /* Hangup flag on zombie state. */
  585                 revents |= POLLHUP;
  586         } else if (events & (POLLOUT|POLLWRNORM)) {
  587                 /* See if we can write something. */
  588                 if (ttydisc_write_poll(tp) > 0)
  589                         revents |= events & (POLLOUT|POLLWRNORM);
  590         }
  591 
  592         if (revents == 0) {
  593                 if (events & (POLLIN|POLLRDNORM))
  594                         selrecord(td, &tp->t_inpoll);
  595                 if (events & (POLLOUT|POLLWRNORM))
  596                         selrecord(td, &tp->t_outpoll);
  597         }
  598 
  599         tty_unlock(tp);
  600 
  601         return (revents);
  602 }
  603 
  604 static int
  605 ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
  606 {
  607         struct tty *tp = dev->si_drv1;
  608         int error;
  609 
  610         /* Handle mmap() through the driver. */
  611 
  612         error = ttydev_enter(tp);
  613         if (error)
  614                 return (-1);
  615         error = ttydevsw_mmap(tp, offset, paddr, nprot);
  616         tty_unlock(tp);
  617 
  618         return (error);
  619 }
  620 
  621 /*
  622  * kqueue support.
  623  */
  624 
  625 static void
  626 tty_kqops_read_detach(struct knote *kn)
  627 {
  628         struct tty *tp = kn->kn_hook;
  629 
  630         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  631 }
  632 
  633 static int
  634 tty_kqops_read_event(struct knote *kn, long hint)
  635 {
  636         struct tty *tp = kn->kn_hook;
  637 
  638         tty_lock_assert(tp, MA_OWNED);
  639 
  640         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  641                 kn->kn_flags |= EV_EOF;
  642                 return (1);
  643         } else {
  644                 kn->kn_data = ttydisc_read_poll(tp);
  645                 return (kn->kn_data > 0);
  646         }
  647 }
  648 
  649 static void
  650 tty_kqops_write_detach(struct knote *kn)
  651 {
  652         struct tty *tp = kn->kn_hook;
  653 
  654         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  655 }
  656 
  657 static int
  658 tty_kqops_write_event(struct knote *kn, long hint)
  659 {
  660         struct tty *tp = kn->kn_hook;
  661 
  662         tty_lock_assert(tp, MA_OWNED);
  663 
  664         if (tty_gone(tp)) {
  665                 kn->kn_flags |= EV_EOF;
  666                 return (1);
  667         } else {
  668                 kn->kn_data = ttydisc_write_poll(tp);
  669                 return (kn->kn_data > 0);
  670         }
  671 }
  672 
  673 static struct filterops tty_kqops_read =
  674     { 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
  675 static struct filterops tty_kqops_write =
  676     { 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
  677 
  678 static int
  679 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  680 {
  681         struct tty *tp = dev->si_drv1;
  682         int error;
  683 
  684         error = ttydev_enter(tp);
  685         if (error)
  686                 return (error);
  687 
  688         switch (kn->kn_filter) {
  689         case EVFILT_READ:
  690                 kn->kn_hook = tp;
  691                 kn->kn_fop = &tty_kqops_read;
  692                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  693                 break;
  694         case EVFILT_WRITE:
  695                 kn->kn_hook = tp;
  696                 kn->kn_fop = &tty_kqops_write;
  697                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  698                 break;
  699         default:
  700                 error = EINVAL;
  701                 break;
  702         }
  703 
  704         tty_unlock(tp);
  705         return (error);
  706 }
  707 
  708 static struct cdevsw ttydev_cdevsw = {
  709         .d_version      = D_VERSION,
  710         .d_open         = ttydev_open,
  711         .d_close        = ttydev_close,
  712         .d_read         = ttydev_read,
  713         .d_write        = ttydev_write,
  714         .d_ioctl        = ttydev_ioctl,
  715         .d_kqfilter     = ttydev_kqfilter,
  716         .d_poll         = ttydev_poll,
  717         .d_mmap         = ttydev_mmap,
  718         .d_name         = "ttydev",
  719         .d_flags        = D_TTY,
  720 };
  721 
  722 /*
  723  * Init/lock-state devices
  724  */
  725 
  726 static int
  727 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  728 {
  729         struct tty *tp = dev->si_drv1;
  730         int error = 0;
  731 
  732         tty_lock(tp);
  733         if (tty_gone(tp))
  734                 error = ENODEV;
  735         tty_unlock(tp);
  736 
  737         return (error);
  738 }
  739 
  740 static int
  741 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
  742 {
  743         return (0);
  744 }
  745 
  746 static int
  747 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
  748 {
  749         return (ENODEV);
  750 }
  751 
  752 static int
  753 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  754     struct thread *td)
  755 {
  756         struct tty *tp = dev->si_drv1;
  757         int error = 0;
  758 
  759         tty_lock(tp);
  760         if (tty_gone(tp)) {
  761                 error = ENODEV;
  762                 goto done;
  763         }
  764 
  765         switch (cmd) {
  766         case TIOCGETA:
  767                 /* Obtain terminal flags through tcgetattr(). */
  768                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  769                 break;
  770         case TIOCSETA:
  771                 /* Set terminal flags through tcsetattr(). */
  772                 error = priv_check(td, PRIV_TTY_SETA);
  773                 if (error)
  774                         break;
  775                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  776                 break;
  777         case TIOCGETD:
  778                 *(int *)data = TTYDISC;
  779                 break;
  780         case TIOCGWINSZ:
  781                 bzero(data, sizeof(struct winsize));
  782                 break;
  783         default:
  784                 error = ENOTTY;
  785         }
  786 
  787 done:   tty_unlock(tp);
  788         return (error);
  789 }
  790 
  791 static struct cdevsw ttyil_cdevsw = {
  792         .d_version      = D_VERSION,
  793         .d_open         = ttyil_open,
  794         .d_close        = ttyil_close,
  795         .d_read         = ttyil_rdwr,
  796         .d_write        = ttyil_rdwr,
  797         .d_ioctl        = ttyil_ioctl,
  798         .d_name         = "ttyil",
  799         .d_flags        = D_TTY,
  800 };
  801 
  802 static void
  803 tty_init_termios(struct tty *tp)
  804 {
  805         struct termios *t = &tp->t_termios_init_in;
  806 
  807         t->c_cflag = TTYDEF_CFLAG;
  808         t->c_iflag = TTYDEF_IFLAG;
  809         t->c_lflag = TTYDEF_LFLAG;
  810         t->c_oflag = TTYDEF_OFLAG;
  811         t->c_ispeed = TTYDEF_SPEED;
  812         t->c_ospeed = TTYDEF_SPEED;
  813         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  814 
  815         tp->t_termios_init_out = *t;
  816 }
  817 
  818 void
  819 tty_init_console(struct tty *tp, speed_t s)
  820 {
  821         struct termios *ti = &tp->t_termios_init_in;
  822         struct termios *to = &tp->t_termios_init_out;
  823 
  824         if (s != 0) {
  825                 ti->c_ispeed = ti->c_ospeed = s;
  826                 to->c_ispeed = to->c_ospeed = s;
  827         }
  828 
  829         ti->c_cflag |= CLOCAL;
  830         to->c_cflag |= CLOCAL;
  831 }
  832 
  833 /*
  834  * Standard device routine implementations, mostly meant for
  835  * pseudo-terminal device drivers. When a driver creates a new terminal
  836  * device class, missing routines are patched.
  837  */
  838 
  839 static int
  840 ttydevsw_defopen(struct tty *tp)
  841 {
  842 
  843         return (0);
  844 }
  845 
  846 static void
  847 ttydevsw_defclose(struct tty *tp)
  848 {
  849 }
  850 
  851 static void
  852 ttydevsw_defoutwakeup(struct tty *tp)
  853 {
  854 
  855         panic("Terminal device has output, while not implemented");
  856 }
  857 
  858 static void
  859 ttydevsw_definwakeup(struct tty *tp)
  860 {
  861 }
  862 
  863 static int
  864 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
  865 {
  866 
  867         return (ENOIOCTL);
  868 }
  869 
  870 static int
  871 ttydevsw_defparam(struct tty *tp, struct termios *t)
  872 {
  873 
  874         /* Use a fake baud rate, we're not a real device. */
  875         t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
  876 
  877         return (0);
  878 }
  879 
  880 static int
  881 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
  882 {
  883 
  884         /* Simulate a carrier to make the TTY layer happy. */
  885         return (SER_DCD);
  886 }
  887 
  888 static int
  889 ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
  890     int nprot)
  891 {
  892 
  893         return (-1);
  894 }
  895 
  896 static void
  897 ttydevsw_defpktnotify(struct tty *tp, char event)
  898 {
  899 }
  900 
  901 static void
  902 ttydevsw_deffree(void *softc)
  903 {
  904 
  905         panic("Terminal device freed without a free-handler");
  906 }
  907 
  908 /*
  909  * TTY allocation and deallocation. TTY devices can be deallocated when
  910  * the driver doesn't use it anymore, when the TTY isn't a session's
  911  * controlling TTY and when the device node isn't opened through devfs.
  912  */
  913 
  914 struct tty *
  915 tty_alloc(struct ttydevsw *tsw, void *sc)
  916 {
  917 
  918         return (tty_alloc_mutex(tsw, sc, NULL));
  919 }
  920 
  921 struct tty *
  922 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
  923 {
  924         struct tty *tp;
  925 
  926         /* Make sure the driver defines all routines. */
  927 #define PATCH_FUNC(x) do {                              \
  928         if (tsw->tsw_ ## x == NULL)                     \
  929                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
  930 } while (0)
  931         PATCH_FUNC(open);
  932         PATCH_FUNC(close);
  933         PATCH_FUNC(outwakeup);
  934         PATCH_FUNC(inwakeup);
  935         PATCH_FUNC(ioctl);
  936         PATCH_FUNC(param);
  937         PATCH_FUNC(modem);
  938         PATCH_FUNC(mmap);
  939         PATCH_FUNC(pktnotify);
  940         PATCH_FUNC(free);
  941 #undef PATCH_FUNC
  942 
  943         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
  944         tp->t_devsw = tsw;
  945         tp->t_devswsoftc = sc;
  946         tp->t_flags = tsw->tsw_flags;
  947 
  948         tty_init_termios(tp);
  949 
  950         cv_init(&tp->t_inwait, "ttyin");
  951         cv_init(&tp->t_outwait, "ttyout");
  952         cv_init(&tp->t_outserwait, "ttyosr");
  953         cv_init(&tp->t_bgwait, "ttybg");
  954         cv_init(&tp->t_dcdwait, "ttydcd");
  955 
  956         /* Allow drivers to use a custom mutex to lock the TTY. */
  957         if (mutex != NULL) {
  958                 tp->t_mtx = mutex;
  959         } else {
  960                 tp->t_mtx = &tp->t_mtxobj;
  961                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
  962         }
  963 
  964         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
  965         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
  966 
  967         sx_xlock(&tty_list_sx);
  968         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
  969         tty_list_count++;
  970         sx_xunlock(&tty_list_sx);
  971 
  972         return (tp);
  973 }
  974 
  975 static void
  976 tty_dealloc(void *arg)
  977 {
  978         struct tty *tp = arg;
  979 
  980         sx_xlock(&tty_list_sx);
  981         TAILQ_REMOVE(&tty_list, tp, t_list);
  982         tty_list_count--;
  983         sx_xunlock(&tty_list_sx);
  984 
  985         /* Make sure we haven't leaked buffers. */
  986         MPASS(ttyinq_getsize(&tp->t_inq) == 0);
  987         MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
  988 
  989         knlist_destroy(&tp->t_inpoll.si_note);
  990         knlist_destroy(&tp->t_outpoll.si_note);
  991 
  992         cv_destroy(&tp->t_inwait);
  993         cv_destroy(&tp->t_outwait);
  994         cv_destroy(&tp->t_bgwait);
  995         cv_destroy(&tp->t_dcdwait);
  996         cv_destroy(&tp->t_outserwait);
  997 
  998         if (tp->t_mtx == &tp->t_mtxobj)
  999                 mtx_destroy(&tp->t_mtxobj);
 1000         ttydevsw_free(tp);
 1001         free(tp, M_TTY);
 1002 }
 1003 
 1004 static void
 1005 tty_rel_free(struct tty *tp)
 1006 {
 1007         struct cdev *dev;
 1008 
 1009         tty_lock_assert(tp, MA_OWNED);
 1010 
 1011 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1012         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1013                 /* TTY is still in use. */
 1014                 tty_unlock(tp);
 1015                 return;
 1016         }
 1017 
 1018         /* TTY can be deallocated. */
 1019         dev = tp->t_dev;
 1020         tp->t_dev = NULL;
 1021         tty_unlock(tp);
 1022 
 1023         destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1024 }
 1025 
 1026 void
 1027 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1028 {
 1029         MPASS(tp->t_sessioncnt > 0);
 1030         tty_lock_assert(tp, MA_OWNED);
 1031 
 1032         if (tp->t_pgrp == pg)
 1033                 tp->t_pgrp = NULL;
 1034         
 1035         tty_unlock(tp);
 1036 }
 1037 
 1038 void
 1039 tty_rel_sess(struct tty *tp, struct session *sess)
 1040 {
 1041         MPASS(tp->t_sessioncnt > 0);
 1042 
 1043         /* Current session has left. */
 1044         if (tp->t_session == sess) {
 1045                 tp->t_session = NULL;
 1046                 MPASS(tp->t_pgrp == NULL);
 1047         }
 1048         tp->t_sessioncnt--;
 1049         tty_rel_free(tp);
 1050 }
 1051 
 1052 void
 1053 tty_rel_gone(struct tty *tp)
 1054 {
 1055         MPASS(!tty_gone(tp));
 1056 
 1057         /* Simulate carrier removal. */
 1058         ttydisc_modem(tp, 0);
 1059 
 1060         /* Wake up all blocked threads. */
 1061         tty_wakeup(tp, FREAD|FWRITE);
 1062         cv_broadcast(&tp->t_bgwait);
 1063         cv_broadcast(&tp->t_dcdwait);
 1064 
 1065         tp->t_flags |= TF_GONE;
 1066         tty_rel_free(tp);
 1067 }
 1068 
 1069 /*
 1070  * Exposing information about current TTY's through sysctl
 1071  */
 1072 
 1073 static void
 1074 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1075 {
 1076         tty_lock_assert(tp, MA_OWNED);
 1077 
 1078         xt->xt_size = sizeof(struct xtty);
 1079         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1080         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1081         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1082         xt->xt_inlow = tp->t_inlow;
 1083         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1084         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1085         xt->xt_outlow = tp->t_outlow;
 1086         xt->xt_column = tp->t_column;
 1087         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1088         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1089         xt->xt_flags = tp->t_flags;
 1090         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1091 }
 1092 
 1093 static int
 1094 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1095 {
 1096         unsigned long lsize;
 1097         struct xtty *xtlist, *xt;
 1098         struct tty *tp;
 1099         int error;
 1100 
 1101         sx_slock(&tty_list_sx);
 1102         lsize = tty_list_count * sizeof(struct xtty);
 1103         if (lsize == 0) {
 1104                 sx_sunlock(&tty_list_sx);
 1105                 return (0);
 1106         }
 1107 
 1108         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1109 
 1110         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1111                 tty_lock(tp);
 1112                 tty_to_xtty(tp, xt);
 1113                 tty_unlock(tp);
 1114                 xt++;
 1115         }
 1116         sx_sunlock(&tty_list_sx);
 1117 
 1118         error = SYSCTL_OUT(req, xtlist, lsize);
 1119         free(xtlist, M_TTY);
 1120         return (error);
 1121 }
 1122 
 1123 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1124         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1125 
 1126 /*
 1127  * Device node creation. Device has been set up, now we can expose it to
 1128  * the user.
 1129  */
 1130 
 1131 void
 1132 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
 1133 {
 1134         va_list ap;
 1135         struct cdev *dev;
 1136         const char *prefix = "tty";
 1137         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1138         uid_t uid;
 1139         gid_t gid;
 1140         mode_t mode;
 1141 
 1142         /* Remove "tty" prefix from devices like PTY's. */
 1143         if (tp->t_flags & TF_NOPREFIX)
 1144                 prefix = "";
 1145 
 1146         va_start(ap, fmt);
 1147         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1148         va_end(ap);
 1149 
 1150         if (cred == NULL) {
 1151                 /* System device. */
 1152                 uid = UID_ROOT;
 1153                 gid = GID_WHEEL;
 1154                 mode = S_IRUSR|S_IWUSR;
 1155         } else {
 1156                 /* User device. */
 1157                 uid = cred->cr_ruid;
 1158                 gid = GID_TTY;
 1159                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1160         }
 1161 
 1162         /* Master call-in device. */
 1163         dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
 1164             uid, gid, mode, "%s%s", prefix, name);
 1165         dev->si_drv1 = tp;
 1166         tp->t_dev = dev;
 1167 
 1168         /* Slave call-in devices. */
 1169         if (tp->t_flags & TF_INITLOCK) {
 1170                 dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
 1171                     uid, gid, mode, "%s%s.init", prefix, name);
 1172                 dev_depends(tp->t_dev, dev);
 1173                 dev->si_drv1 = tp;
 1174                 dev->si_drv2 = &tp->t_termios_init_in;
 1175 
 1176                 dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
 1177                     uid, gid, mode, "%s%s.lock", prefix, name);
 1178                 dev_depends(tp->t_dev, dev);
 1179                 dev->si_drv1 = tp;
 1180                 dev->si_drv2 = &tp->t_termios_lock_in;
 1181         }
 1182 
 1183         /* Call-out devices. */
 1184         if (tp->t_flags & TF_CALLOUT) {
 1185                 dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
 1186                     UID_UUCP, GID_DIALER, 0660, "cua%s", name);
 1187                 dev_depends(tp->t_dev, dev);
 1188                 dev->si_drv1 = tp;
 1189 
 1190                 /* Slave call-out devices. */
 1191                 if (tp->t_flags & TF_INITLOCK) {
 1192                         dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
 1193                             UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
 1194                         dev_depends(tp->t_dev, dev);
 1195                         dev->si_drv1 = tp;
 1196                         dev->si_drv2 = &tp->t_termios_init_out;
 1197 
 1198                         dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
 1199                             UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
 1200                         dev_depends(tp->t_dev, dev);
 1201                         dev->si_drv1 = tp;
 1202                         dev->si_drv2 = &tp->t_termios_lock_out;
 1203                 }
 1204         }
 1205 }
 1206 
 1207 /*
 1208  * Signalling processes.
 1209  */
 1210 
 1211 void
 1212 tty_signal_sessleader(struct tty *tp, int sig)
 1213 {
 1214         struct proc *p;
 1215 
 1216         tty_lock_assert(tp, MA_OWNED);
 1217         MPASS(sig >= 1 && sig < NSIG);
 1218 
 1219         /* Make signals start output again. */
 1220         tp->t_flags &= ~TF_STOPPED;
 1221         
 1222         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1223                 p = tp->t_session->s_leader;
 1224                 PROC_LOCK(p);
 1225                 psignal(p, sig);
 1226                 PROC_UNLOCK(p);
 1227         }
 1228 }
 1229 
 1230 void
 1231 tty_signal_pgrp(struct tty *tp, int sig)
 1232 {
 1233         ksiginfo_t ksi;
 1234 
 1235         tty_lock_assert(tp, MA_OWNED);
 1236         MPASS(sig >= 1 && sig < NSIG);
 1237 
 1238         /* Make signals start output again. */
 1239         tp->t_flags &= ~TF_STOPPED;
 1240 
 1241         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1242                 tty_info(tp);
 1243         if (tp->t_pgrp != NULL) {
 1244                 ksiginfo_init(&ksi);
 1245                 ksi.ksi_signo = sig;
 1246                 ksi.ksi_code = SI_KERNEL;
 1247                 PGRP_LOCK(tp->t_pgrp);
 1248                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1249                 PGRP_UNLOCK(tp->t_pgrp);
 1250         }
 1251 }
 1252 
 1253 void
 1254 tty_wakeup(struct tty *tp, int flags)
 1255 {
 1256         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1257                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1258 
 1259         if (flags & FWRITE) {
 1260                 cv_broadcast(&tp->t_outwait);
 1261                 selwakeup(&tp->t_outpoll);
 1262                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1263         }
 1264         if (flags & FREAD) {
 1265                 cv_broadcast(&tp->t_inwait);
 1266                 selwakeup(&tp->t_inpoll);
 1267                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1268         }
 1269 }
 1270 
 1271 int
 1272 tty_wait(struct tty *tp, struct cv *cv)
 1273 {
 1274         int error;
 1275         int revokecnt = tp->t_revokecnt;
 1276 
 1277         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1278         MPASS(!tty_gone(tp));
 1279 
 1280         error = cv_wait_sig(cv, tp->t_mtx);
 1281 
 1282         /* Restart the system call when we may have been revoked. */
 1283         if (tp->t_revokecnt != revokecnt)
 1284                 return (ERESTART);
 1285         
 1286         /* Bail out when the device slipped away. */
 1287         if (tty_gone(tp))
 1288                 return (ENXIO);
 1289 
 1290         return (error);
 1291 }
 1292 
 1293 int
 1294 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1295 {
 1296         int error;
 1297         int revokecnt = tp->t_revokecnt;
 1298 
 1299         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1300         MPASS(!tty_gone(tp));
 1301 
 1302         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1303 
 1304         /* Restart the system call when we may have been revoked. */
 1305         if (tp->t_revokecnt != revokecnt)
 1306                 return (ERESTART);
 1307         
 1308         /* Bail out when the device slipped away. */
 1309         if (tty_gone(tp))
 1310                 return (ENXIO);
 1311 
 1312         return (error);
 1313 }
 1314 
 1315 void
 1316 tty_flush(struct tty *tp, int flags)
 1317 {
 1318         if (flags & FWRITE) {
 1319                 tp->t_flags &= ~TF_HIWAT_OUT;
 1320                 ttyoutq_flush(&tp->t_outq);
 1321                 tty_wakeup(tp, FWRITE);
 1322                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1323         }
 1324         if (flags & FREAD) {
 1325                 tty_hiwat_in_unblock(tp);
 1326                 ttyinq_flush(&tp->t_inq);
 1327                 ttydevsw_inwakeup(tp);
 1328                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1329         }
 1330 }
 1331 
 1332 static int
 1333 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1334     struct thread *td)
 1335 {
 1336         int error;
 1337 
 1338         switch (cmd) {
 1339         /*
 1340          * Modem commands.
 1341          * The SER_* and TIOCM_* flags are the same, but one bit
 1342          * shifted. I don't know why.
 1343          */
 1344         case TIOCSDTR:
 1345                 ttydevsw_modem(tp, SER_DTR, 0);
 1346                 return (0);
 1347         case TIOCCDTR:
 1348                 ttydevsw_modem(tp, 0, SER_DTR);
 1349                 return (0);
 1350         case TIOCMSET: {
 1351                 int bits = *(int *)data;
 1352                 ttydevsw_modem(tp,
 1353                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1354                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1355                 return (0);
 1356         }
 1357         case TIOCMBIS: {
 1358                 int bits = *(int *)data;
 1359                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1360                 return (0);
 1361         }
 1362         case TIOCMBIC: {
 1363                 int bits = *(int *)data;
 1364                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1365                 return (0);
 1366         }
 1367         case TIOCMGET:
 1368                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1369                 return (0);
 1370 
 1371         case FIOASYNC:
 1372                 if (*(int *)data)
 1373                         tp->t_flags |= TF_ASYNC;
 1374                 else
 1375                         tp->t_flags &= ~TF_ASYNC;
 1376                 return (0);
 1377         case FIONBIO:
 1378                 /* This device supports non-blocking operation. */
 1379                 return (0);
 1380         case FIONREAD:
 1381                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1382                 return (0);
 1383         case FIONWRITE:
 1384         case TIOCOUTQ:
 1385                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1386                 return (0);
 1387         case FIOSETOWN:
 1388                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1389                         /* Not allowed to set ownership. */
 1390                         return (ENOTTY);
 1391 
 1392                 /* Temporarily unlock the TTY to set ownership. */
 1393                 tty_unlock(tp);
 1394                 error = fsetown(*(int *)data, &tp->t_sigio);
 1395                 tty_lock(tp);
 1396                 return (error);
 1397         case FIOGETOWN:
 1398                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1399                         /* Not allowed to set ownership. */
 1400                         return (ENOTTY);
 1401 
 1402                 /* Get ownership. */
 1403                 *(int *)data = fgetown(&tp->t_sigio);
 1404                 return (0);
 1405         case TIOCGETA:
 1406                 /* Obtain terminal flags through tcgetattr(). */
 1407                 *(struct termios*)data = tp->t_termios;
 1408                 return (0);
 1409         case TIOCSETA:
 1410         case TIOCSETAW:
 1411         case TIOCSETAF: {
 1412                 struct termios *t = data;
 1413 
 1414                 /*
 1415                  * Who makes up these funny rules? According to POSIX,
 1416                  * input baud rate is set equal to the output baud rate
 1417                  * when zero.
 1418                  */
 1419                 if (t->c_ispeed == 0)
 1420                         t->c_ispeed = t->c_ospeed;
 1421 
 1422                 /* Discard any unsupported bits. */
 1423                 t->c_iflag &= TTYSUP_IFLAG;
 1424                 t->c_oflag &= TTYSUP_OFLAG;
 1425                 t->c_lflag &= TTYSUP_LFLAG;
 1426                 t->c_cflag &= TTYSUP_CFLAG;
 1427 
 1428                 /* Set terminal flags through tcsetattr(). */
 1429                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1430                         error = tty_drain(tp);
 1431                         if (error)
 1432                                 return (error);
 1433                         if (cmd == TIOCSETAF)
 1434                                 tty_flush(tp, FREAD);
 1435                 }
 1436 
 1437                 /*
 1438                  * Only call param() when the flags really change.
 1439                  */
 1440                 if ((t->c_cflag & CIGNORE) == 0 &&
 1441                     (tp->t_termios.c_cflag != t->c_cflag ||
 1442                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1443                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1444                         error = ttydevsw_param(tp, t);
 1445                         if (error)
 1446                                 return (error);
 1447 
 1448                         /* XXX: CLOCAL? */
 1449                         
 1450                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1451                         tp->t_termios.c_ispeed = t->c_ispeed;
 1452                         tp->t_termios.c_ospeed = t->c_ospeed;
 1453 
 1454                         /* Baud rate has changed - update watermarks. */
 1455                         tty_watermarks(tp);
 1456                 }
 1457 
 1458                 /* Copy new non-device driver parameters. */
 1459                 tp->t_termios.c_iflag = t->c_iflag;
 1460                 tp->t_termios.c_oflag = t->c_oflag;
 1461                 tp->t_termios.c_lflag = t->c_lflag;
 1462                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1463 
 1464                 ttydisc_optimize(tp);
 1465 
 1466                 if ((t->c_lflag & ICANON) == 0) {
 1467                         /*
 1468                          * When in non-canonical mode, wake up all
 1469                          * readers. Canonicalize any partial input. VMIN
 1470                          * and VTIME could also be adjusted.
 1471                          */
 1472                         ttyinq_canonicalize(&tp->t_inq);
 1473                         tty_wakeup(tp, FREAD);
 1474                 }
 1475 
 1476                 /*
 1477                  * For packet mode: notify the PTY consumer that VSTOP
 1478                  * and VSTART may have been changed.
 1479                  */
 1480                 if (tp->t_termios.c_iflag & IXON &&
 1481                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1482                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1483                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1484                 else
 1485                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1486                 return (0);
 1487         }
 1488         case TIOCGETD:
 1489                 /* For compatibility - we only support TTYDISC. */
 1490                 *(int *)data = TTYDISC;
 1491                 return (0);
 1492         case TIOCGPGRP:
 1493                 if (!tty_is_ctty(tp, td->td_proc))
 1494                         return (ENOTTY);
 1495 
 1496                 if (tp->t_pgrp != NULL)
 1497                         *(int *)data = tp->t_pgrp->pg_id;
 1498                 else
 1499                         *(int *)data = NO_PID;
 1500                 return (0);
 1501         case TIOCGSID:
 1502                 if (!tty_is_ctty(tp, td->td_proc))
 1503                         return (ENOTTY);
 1504 
 1505                 MPASS(tp->t_session);
 1506                 *(int *)data = tp->t_session->s_sid;
 1507                 return (0);
 1508         case TIOCSCTTY: {
 1509                 struct proc *p = td->td_proc;
 1510 
 1511                 /* XXX: This looks awful. */
 1512                 tty_unlock(tp);
 1513                 sx_xlock(&proctree_lock);
 1514                 tty_lock(tp);
 1515 
 1516                 if (!SESS_LEADER(p)) {
 1517                         /* Only the session leader may do this. */
 1518                         sx_xunlock(&proctree_lock);
 1519                         return (EPERM);
 1520                 }
 1521 
 1522                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1523                         /* This is already our controlling TTY. */
 1524                         sx_xunlock(&proctree_lock);
 1525                         return (0);
 1526                 }
 1527 
 1528                 if (p->p_session->s_ttyp != NULL ||
 1529                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1530                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1531                         /*
 1532                          * There is already a relation between a TTY and
 1533                          * a session, or the caller is not the session
 1534                          * leader.
 1535                          *
 1536                          * Allow the TTY to be stolen when the vnode is
 1537                          * invalid, but the reference to the TTY is
 1538                          * still active.  This allows immediate reuse of
 1539                          * TTYs of which the session leader has been
 1540                          * killed or the TTY revoked.
 1541                          */
 1542                         sx_xunlock(&proctree_lock);
 1543                         return (EPERM);
 1544                 }
 1545 
 1546                 /* Connect the session to the TTY. */
 1547                 tp->t_session = p->p_session;
 1548                 tp->t_session->s_ttyp = tp;
 1549                 tp->t_sessioncnt++;
 1550                 sx_xunlock(&proctree_lock);
 1551 
 1552                 /* Assign foreground process group. */
 1553                 tp->t_pgrp = p->p_pgrp;
 1554                 PROC_LOCK(p);
 1555                 p->p_flag |= P_CONTROLT;
 1556                 PROC_UNLOCK(p);
 1557 
 1558                 return (0);
 1559         }
 1560         case TIOCSPGRP: {
 1561                 struct pgrp *pg;
 1562 
 1563                 /*
 1564                  * XXX: Temporarily unlock the TTY to locate the process
 1565                  * group. This code would be lot nicer if we would ever
 1566                  * decompose proctree_lock.
 1567                  */
 1568                 tty_unlock(tp);
 1569                 sx_slock(&proctree_lock);
 1570                 pg = pgfind(*(int *)data);
 1571                 if (pg != NULL)
 1572                         PGRP_UNLOCK(pg);
 1573                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1574                         sx_sunlock(&proctree_lock);
 1575                         tty_lock(tp);
 1576                         return (EPERM);
 1577                 }
 1578                 tty_lock(tp);
 1579 
 1580                 /*
 1581                  * Determine if this TTY is the controlling TTY after
 1582                  * relocking the TTY.
 1583                  */
 1584                 if (!tty_is_ctty(tp, td->td_proc)) {
 1585                         sx_sunlock(&proctree_lock);
 1586                         return (ENOTTY);
 1587                 }
 1588                 tp->t_pgrp = pg;
 1589                 sx_sunlock(&proctree_lock);
 1590 
 1591                 /* Wake up the background process groups. */
 1592                 cv_broadcast(&tp->t_bgwait);
 1593                 return (0);
 1594         }
 1595         case TIOCFLUSH: {
 1596                 int flags = *(int *)data;
 1597 
 1598                 if (flags == 0)
 1599                         flags = (FREAD|FWRITE);
 1600                 else
 1601                         flags &= (FREAD|FWRITE);
 1602                 tty_flush(tp, flags);
 1603                 return (0);
 1604         }
 1605         case TIOCDRAIN:
 1606                 /* Drain TTY output. */
 1607                 return tty_drain(tp);
 1608         case TIOCCONS:
 1609                 /* Set terminal as console TTY. */
 1610                 if (*(int *)data) {
 1611                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1612                         if (error)
 1613                                 return (error);
 1614 
 1615                         /*
 1616                          * XXX: constty should really need to be locked!
 1617                          * XXX: allow disconnected constty's to be stolen!
 1618                          */
 1619 
 1620                         if (constty == tp)
 1621                                 return (0);
 1622                         if (constty != NULL)
 1623                                 return (EBUSY);
 1624 
 1625                         tty_unlock(tp);
 1626                         constty_set(tp);
 1627                         tty_lock(tp);
 1628                 } else if (constty == tp) {
 1629                         constty_clear();
 1630                 }
 1631                 return (0);
 1632         case TIOCGWINSZ:
 1633                 /* Obtain window size. */
 1634                 *(struct winsize*)data = tp->t_winsize;
 1635                 return (0);
 1636         case TIOCSWINSZ:
 1637                 /* Set window size. */
 1638                 if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
 1639                         return (0);
 1640                 tp->t_winsize = *(struct winsize*)data;
 1641                 tty_signal_pgrp(tp, SIGWINCH);
 1642                 return (0);
 1643         case TIOCEXCL:
 1644                 tp->t_flags |= TF_EXCLUDE;
 1645                 return (0);
 1646         case TIOCNXCL:
 1647                 tp->t_flags &= ~TF_EXCLUDE;
 1648                 return (0);
 1649         case TIOCSTOP:
 1650                 tp->t_flags |= TF_STOPPED;
 1651                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1652                 return (0);
 1653         case TIOCSTART:
 1654                 tp->t_flags &= ~TF_STOPPED;
 1655                 ttydevsw_outwakeup(tp);
 1656                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1657                 return (0);
 1658         case TIOCSTAT:
 1659                 tty_info(tp);
 1660                 return (0);
 1661         case TIOCSTI:
 1662                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1663                         return (EPERM);
 1664                 if (!tty_is_ctty(tp, td->td_proc) &&
 1665                     priv_check(td, PRIV_TTY_STI))
 1666                         return (EACCES);
 1667                 ttydisc_rint(tp, *(char *)data, 0);
 1668                 ttydisc_rint_done(tp);
 1669                 return (0);
 1670         }
 1671 
 1672 #ifdef COMPAT_43TTY
 1673         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1674 #else /* !COMPAT_43TTY */
 1675         return (ENOIOCTL);
 1676 #endif /* COMPAT_43TTY */
 1677 }
 1678 
 1679 int
 1680 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1681 {
 1682         int error;
 1683 
 1684         tty_lock_assert(tp, MA_OWNED);
 1685 
 1686         if (tty_gone(tp))
 1687                 return (ENXIO);
 1688         
 1689         error = ttydevsw_ioctl(tp, cmd, data, td);
 1690         if (error == ENOIOCTL)
 1691                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1692 
 1693         return (error);
 1694 }
 1695 
 1696 dev_t
 1697 tty_udev(struct tty *tp)
 1698 {
 1699         if (tp->t_dev)
 1700                 return dev2udev(tp->t_dev);
 1701         else
 1702                 return NODEV;
 1703 }
 1704 
 1705 int
 1706 tty_checkoutq(struct tty *tp)
 1707 {
 1708 
 1709         /* 256 bytes should be enough to print a log message. */
 1710         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1711 }
 1712 
 1713 void
 1714 tty_hiwat_in_block(struct tty *tp)
 1715 {
 1716 
 1717         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1718             tp->t_termios.c_iflag & IXOFF &&
 1719             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1720                 /*
 1721                  * Input flow control. Only enter the high watermark when we
 1722                  * can successfully store the VSTOP character.
 1723                  */
 1724                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1725                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1726                         tp->t_flags |= TF_HIWAT_IN;
 1727         } else {
 1728                 /* No input flow control. */
 1729                 tp->t_flags |= TF_HIWAT_IN;
 1730         }
 1731 }
 1732 
 1733 void
 1734 tty_hiwat_in_unblock(struct tty *tp)
 1735 {
 1736 
 1737         if (tp->t_flags & TF_HIWAT_IN &&
 1738             tp->t_termios.c_iflag & IXOFF &&
 1739             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1740                 /*
 1741                  * Input flow control. Only leave the high watermark when we
 1742                  * can successfully store the VSTART character.
 1743                  */
 1744                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1745                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1746                         tp->t_flags &= ~TF_HIWAT_IN;
 1747         } else {
 1748                 /* No input flow control. */
 1749                 tp->t_flags &= ~TF_HIWAT_IN;
 1750         }
 1751 
 1752         if (!tty_gone(tp))
 1753                 ttydevsw_inwakeup(tp);
 1754 }
 1755 
 1756 /*
 1757  * TTY hooks interface.
 1758  */
 1759 
 1760 static int
 1761 ttyhook_defrint(struct tty *tp, char c, int flags)
 1762 {
 1763 
 1764         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1765                 return (-1);
 1766         
 1767         return (0);
 1768 }
 1769 
 1770 int
 1771 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
 1772     struct ttyhook *th, void *softc)
 1773 {
 1774         struct tty *tp;
 1775         struct file *fp;
 1776         struct cdev *dev;
 1777         struct cdevsw *cdp;
 1778         struct filedesc *fdp;
 1779         int error;
 1780 
 1781         /* Validate the file descriptor. */
 1782         if ((fdp = p->p_fd) == NULL)
 1783                 return (EBADF);
 1784 
 1785         fp = fget_unlocked(fdp, fd);
 1786         if (fp == NULL)
 1787                 return (EBADF);
 1788         if (fp->f_ops == &badfileops) {
 1789                 error = EBADF;
 1790                 goto done1;
 1791         }
 1792         
 1793         /*
 1794          * Make sure the vnode is bound to a character device.
 1795          * Unlocked check for the vnode type is ok there, because we
 1796          * only shall prevent calling devvn_refthread on the file that
 1797          * never has been opened over a character device.
 1798          */
 1799         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1800                 error = EINVAL;
 1801                 goto done1;
 1802         }
 1803 
 1804         /* Make sure it is a TTY. */
 1805         cdp = devvn_refthread(fp->f_vnode, &dev);
 1806         if (cdp == NULL) {
 1807                 error = ENXIO;
 1808                 goto done1;
 1809         }
 1810         if (dev != fp->f_data) {
 1811                 error = ENXIO;
 1812                 goto done2;
 1813         }
 1814         if (cdp != &ttydev_cdevsw) {
 1815                 error = ENOTTY;
 1816                 goto done2;
 1817         }
 1818         tp = dev->si_drv1;
 1819 
 1820         /* Try to attach the hook to the TTY. */
 1821         error = EBUSY;
 1822         tty_lock(tp);
 1823         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1824         if (tp->t_flags & TF_HOOK)
 1825                 goto done3;
 1826 
 1827         tp->t_flags |= TF_HOOK;
 1828         tp->t_hook = th;
 1829         tp->t_hooksoftc = softc;
 1830         *rtp = tp;
 1831         error = 0;
 1832 
 1833         /* Maybe we can switch into bypass mode now. */
 1834         ttydisc_optimize(tp);
 1835 
 1836         /* Silently convert rint() calls to rint_bypass() when possible. */
 1837         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 1838                 th->th_rint = ttyhook_defrint;
 1839 
 1840 done3:  tty_unlock(tp);
 1841 done2:  dev_relthread(dev);
 1842 done1:  fdrop(fp, curthread);
 1843         return (error);
 1844 }
 1845 
 1846 void
 1847 ttyhook_unregister(struct tty *tp)
 1848 {
 1849 
 1850         tty_lock_assert(tp, MA_OWNED);
 1851         MPASS(tp->t_flags & TF_HOOK);
 1852 
 1853         /* Disconnect the hook. */
 1854         tp->t_flags &= ~TF_HOOK;
 1855         tp->t_hook = NULL;
 1856 
 1857         /* Maybe we need to leave bypass mode. */
 1858         ttydisc_optimize(tp);
 1859 
 1860         /* Maybe deallocate the TTY as well. */
 1861         tty_rel_free(tp);
 1862 }
 1863 
 1864 /*
 1865  * /dev/console handling.
 1866  */
 1867 
 1868 static int
 1869 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 1870 {
 1871         struct tty *tp;
 1872 
 1873         /* System has no console device. */
 1874         if (dev_console_filename == NULL)
 1875                 return (ENXIO);
 1876 
 1877         /* Look up corresponding TTY by device name. */
 1878         sx_slock(&tty_list_sx);
 1879         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1880                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 1881                         dev_console->si_drv1 = tp;
 1882                         break;
 1883                 }
 1884         }
 1885         sx_sunlock(&tty_list_sx);
 1886 
 1887         /* System console has no TTY associated. */
 1888         if (dev_console->si_drv1 == NULL)
 1889                 return (ENXIO);
 1890         
 1891         return (ttydev_open(dev, oflags, devtype, td));
 1892 }
 1893 
 1894 static int
 1895 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 1896 {
 1897 
 1898         log_console(uio);
 1899 
 1900         return (ttydev_write(dev, uio, ioflag));
 1901 }
 1902 
 1903 /*
 1904  * /dev/console is a little different than normal TTY's.  When opened,
 1905  * it determines which TTY to use.  When data gets written to it, it
 1906  * will be logged in the kernel message buffer.
 1907  */
 1908 static struct cdevsw ttyconsdev_cdevsw = {
 1909         .d_version      = D_VERSION,
 1910         .d_open         = ttyconsdev_open,
 1911         .d_close        = ttydev_close,
 1912         .d_read         = ttydev_read,
 1913         .d_write        = ttyconsdev_write,
 1914         .d_ioctl        = ttydev_ioctl,
 1915         .d_kqfilter     = ttydev_kqfilter,
 1916         .d_poll         = ttydev_poll,
 1917         .d_mmap         = ttydev_mmap,
 1918         .d_name         = "ttyconsdev",
 1919         .d_flags        = D_TTY,
 1920 };
 1921 
 1922 static void
 1923 ttyconsdev_init(void *unused)
 1924 {
 1925 
 1926         dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
 1927             0600, "console");
 1928 }
 1929 
 1930 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 1931 
 1932 void
 1933 ttyconsdev_select(const char *name)
 1934 {
 1935 
 1936         dev_console_filename = name;
 1937 }
 1938 
 1939 /*
 1940  * Debugging routines.
 1941  */
 1942 
 1943 #include "opt_ddb.h"
 1944 #ifdef DDB
 1945 #include <ddb/ddb.h>
 1946 #include <ddb/db_sym.h>
 1947 
 1948 static struct {
 1949         int flag;
 1950         char val;
 1951 } ttystates[] = {
 1952 #if 0
 1953         { TF_NOPREFIX,          'N' },
 1954 #endif
 1955         { TF_INITLOCK,          'I' },
 1956         { TF_CALLOUT,           'C' },
 1957 
 1958         /* Keep these together -> 'Oi' and 'Oo'. */
 1959         { TF_OPENED,            'O' },
 1960         { TF_OPENED_IN,         'i' },
 1961         { TF_OPENED_OUT,        'o' },
 1962         { TF_OPENED_CONS,       'c' },
 1963 
 1964         { TF_GONE,              'G' },
 1965         { TF_OPENCLOSE,         'B' },
 1966         { TF_ASYNC,             'Y' },
 1967         { TF_LITERAL,           'L' },
 1968 
 1969         /* Keep these together -> 'Hi' and 'Ho'. */
 1970         { TF_HIWAT,             'H' },
 1971         { TF_HIWAT_IN,          'i' },
 1972         { TF_HIWAT_OUT,         'o' },
 1973 
 1974         { TF_STOPPED,           'S' },
 1975         { TF_EXCLUDE,           'X' },
 1976         { TF_BYPASS,            'l' },
 1977         { TF_ZOMBIE,            'Z' },
 1978         { TF_HOOK,              's' },
 1979 
 1980         /* Keep these together -> 'bi' and 'bo'. */
 1981         { TF_BUSY,              'b' },
 1982         { TF_BUSY_IN,           'i' },
 1983         { TF_BUSY_OUT,          'o' },
 1984 
 1985         { 0,                    '\0'},
 1986 };
 1987 
 1988 #define TTY_FLAG_BITS \
 1989         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
 1990         "\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
 1991         "\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
 1992 
 1993 #define DB_PRINTSYM(name, addr) \
 1994         db_printf("%s  " #name ": ", sep); \
 1995         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 1996         db_printf("\n");
 1997 
 1998 static void
 1999 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2000 {
 2001         db_printf("%sdevsw: ", sep);
 2002         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2003         db_printf(" (%p)\n", tsw);
 2004         DB_PRINTSYM(open, tsw->tsw_open);
 2005         DB_PRINTSYM(close, tsw->tsw_close);
 2006         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2007         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2008         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2009         DB_PRINTSYM(param, tsw->tsw_param);
 2010         DB_PRINTSYM(modem, tsw->tsw_modem);
 2011         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2012         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2013         DB_PRINTSYM(free, tsw->tsw_free);
 2014 }
 2015 static void
 2016 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2017 {
 2018         db_printf("%shook: ", sep);
 2019         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2020         db_printf(" (%p)\n", th);
 2021         if (th == NULL)
 2022                 return;
 2023         DB_PRINTSYM(rint, th->th_rint);
 2024         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2025         DB_PRINTSYM(rint_done, th->th_rint_done);
 2026         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2027         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2028         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2029         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2030         DB_PRINTSYM(close, th->th_close);
 2031 }
 2032 
 2033 static void
 2034 _db_show_termios(const char *name, const struct termios *t)
 2035 {
 2036 
 2037         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2038             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2039             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2040             t->c_ispeed, t->c_ospeed);
 2041 }
 2042 
 2043 /* DDB command to show TTY statistics. */
 2044 DB_SHOW_COMMAND(tty, db_show_tty)
 2045 {
 2046         struct tty *tp;
 2047 
 2048         if (!have_addr) {
 2049                 db_printf("usage: show tty <addr>\n");
 2050                 return;
 2051         }
 2052         tp = (struct tty *)addr;
 2053 
 2054         db_printf("0x%p: %s\n", tp, tty_devname(tp));
 2055         db_printf("\tmtx: %p\n", tp->t_mtx);
 2056         db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
 2057         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2058 
 2059         /* Buffering mechanisms. */
 2060         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2061             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2062             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2063             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2064         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2065             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2066             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2067         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2068         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2069         _db_show_termios("\ttermios", &tp->t_termios);
 2070         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2071             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2072             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2073         db_printf("\tcolumn: %u\n", tp->t_column);
 2074         db_printf("\twritepos: %u\n", tp->t_writepos);
 2075         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2076 
 2077         /* Init/lock-state devices. */
 2078         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2079         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2080         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2081         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2082 
 2083         /* Hooks */
 2084         _db_show_devsw("\t", tp->t_devsw);
 2085         _db_show_hooks("\t", tp->t_hook);
 2086 
 2087         /* Process info. */
 2088         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2089             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2090             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2091         db_printf("\tsession: %p", tp->t_session);
 2092         if (tp->t_session != NULL)
 2093             db_printf(" count %u leader %p tty %p sid %d login %s",
 2094                 tp->t_session->s_count, tp->t_session->s_leader,
 2095                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2096                 tp->t_session->s_login);
 2097         db_printf("\n");
 2098         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2099         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2100         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2101         db_printf("\tdev: %p\n", tp->t_dev);
 2102 }
 2103 
 2104 /* DDB command to list TTYs. */
 2105 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2106 {
 2107         struct tty *tp;
 2108         size_t isiz, osiz;
 2109         int i, j;
 2110 
 2111         /* Make the output look like `pstat -t'. */
 2112         db_printf("PTR        ");
 2113 #if defined(__LP64__)
 2114         db_printf("        ");
 2115 #endif
 2116         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2117             "COL  SESS  PGID STATE\n");
 2118 
 2119         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2120                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2121                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2122 
 2123                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
 2124                     tp,
 2125                     tty_devname(tp),
 2126                     isiz,
 2127                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2128                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2129                     isiz - tp->t_inlow,
 2130                     osiz,
 2131                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2132                     osiz - tp->t_outlow,
 2133                     MIN(tp->t_column, 99999),
 2134                     tp->t_session ? tp->t_session->s_sid : 0,
 2135                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2136 
 2137                 /* Flag bits. */
 2138                 for (i = j = 0; ttystates[i].flag; i++)
 2139                         if (tp->t_flags & ttystates[i].flag) {
 2140                                 db_printf("%c", ttystates[i].val);
 2141                                 j++;
 2142                         }
 2143                 if (j == 0)
 2144                         db_printf("-");
 2145                 db_printf("\n");
 2146         }
 2147 }
 2148 #endif /* DDB */

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