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: head/sys/kern/tty.c 294836 2016-01-26 14:46:39Z kib $");
   32 
   33 #include "opt_capsicum.h"
   34 #include "opt_compat.h"
   35 
   36 #include <sys/param.h>
   37 #include <sys/capsicum.h>
   38 #include <sys/conf.h>
   39 #include <sys/cons.h>
   40 #include <sys/fcntl.h>
   41 #include <sys/file.h>
   42 #include <sys/filedesc.h>
   43 #include <sys/filio.h>
   44 #ifdef COMPAT_43TTY
   45 #include <sys/ioctl_compat.h>
   46 #endif /* COMPAT_43TTY */
   47 #include <sys/kernel.h>
   48 #include <sys/limits.h>
   49 #include <sys/malloc.h>
   50 #include <sys/mount.h>
   51 #include <sys/poll.h>
   52 #include <sys/priv.h>
   53 #include <sys/proc.h>
   54 #include <sys/serial.h>
   55 #include <sys/signal.h>
   56 #include <sys/stat.h>
   57 #include <sys/sx.h>
   58 #include <sys/sysctl.h>
   59 #include <sys/systm.h>
   60 #include <sys/tty.h>
   61 #include <sys/ttycom.h>
   62 #define TTYDEFCHARS
   63 #include <sys/ttydefaults.h>
   64 #undef TTYDEFCHARS
   65 #include <sys/ucred.h>
   66 #include <sys/vnode.h>
   67 
   68 #include <machine/stdarg.h>
   69 
   70 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
   71 
   72 static void tty_rel_free(struct tty *tp);
   73 
   74 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
   75 static struct sx tty_list_sx;
   76 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
   77 static unsigned int tty_list_count = 0;
   78 
   79 /* Character device of /dev/console. */
   80 static struct cdev      *dev_console;
   81 static const char       *dev_console_filename;
   82 
   83 /*
   84  * Flags that are supported and stored by this implementation.
   85  */
   86 #define TTYSUP_IFLAG    (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
   87                         INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
   88 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
   89 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
   90                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
   91                         FLUSHO|NOKERNINFO|NOFLSH)
   92 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
   93                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
   94                         CDSR_OFLOW|CCAR_OFLOW)
   95 
   96 #define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
   97 
   98 /*
   99  * Set TTY buffer sizes.
  100  */
  101 
  102 #define TTYBUF_MAX      65536
  103 
  104 static void
  105 tty_watermarks(struct tty *tp)
  106 {
  107         size_t bs = 0;
  108 
  109         /* Provide an input buffer for 0.2 seconds of data. */
  110         if (tp->t_termios.c_cflag & CREAD)
  111                 bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
  112         ttyinq_setsize(&tp->t_inq, tp, bs);
  113 
  114         /* Set low watermark at 10% (when 90% is available). */
  115         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
  116 
  117         /* Provide an output buffer for 0.2 seconds of data. */
  118         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
  119         ttyoutq_setsize(&tp->t_outq, tp, bs);
  120 
  121         /* Set low watermark at 10% (when 90% is available). */
  122         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
  123 }
  124 
  125 static int
  126 tty_drain(struct tty *tp, int leaving)
  127 {
  128         size_t bytesused;
  129         int error;
  130 
  131         if (ttyhook_hashook(tp, getc_inject))
  132                 /* buffer is inaccessible */
  133                 return (0);
  134 
  135         while (ttyoutq_bytesused(&tp->t_outq) > 0 || ttydevsw_busy(tp)) {
  136                 ttydevsw_outwakeup(tp);
  137                 /* Could be handled synchronously. */
  138                 bytesused = ttyoutq_bytesused(&tp->t_outq);
  139                 if (bytesused == 0 && !ttydevsw_busy(tp))
  140                         return (0);
  141 
  142                 /* Wait for data to be drained. */
  143                 if (leaving) {
  144                         error = tty_timedwait(tp, &tp->t_outwait, hz);
  145                         if (error == EWOULDBLOCK &&
  146                             ttyoutq_bytesused(&tp->t_outq) < bytesused)
  147                                 error = 0;
  148                 } else
  149                         error = tty_wait(tp, &tp->t_outwait);
  150 
  151                 if (error)
  152                         return (error);
  153         }
  154 
  155         return (0);
  156 }
  157 
  158 /*
  159  * Though ttydev_enter() and ttydev_leave() seem to be related, they
  160  * don't have to be used together. ttydev_enter() is used by the cdev
  161  * operations to prevent an actual operation from being processed when
  162  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
  163  * and ttydev_close() to determine whether per-TTY data should be
  164  * deallocated.
  165  */
  166 
  167 static __inline int
  168 ttydev_enter(struct tty *tp)
  169 {
  170 
  171         tty_lock(tp);
  172 
  173         if (tty_gone(tp) || !tty_opened(tp)) {
  174                 /* Device is already gone. */
  175                 tty_unlock(tp);
  176                 return (ENXIO);
  177         }
  178 
  179         return (0);
  180 }
  181 
  182 static void
  183 ttydev_leave(struct tty *tp)
  184 {
  185 
  186         tty_lock_assert(tp, MA_OWNED);
  187 
  188         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
  189                 /* Device is still opened somewhere. */
  190                 tty_unlock(tp);
  191                 return;
  192         }
  193 
  194         tp->t_flags |= TF_OPENCLOSE;
  195 
  196         /* Stop asynchronous I/O. */
  197         funsetown(&tp->t_sigio);
  198 
  199         /* Remove console TTY. */
  200         if (constty == tp)
  201                 constty_clear();
  202 
  203         /* Drain any output. */
  204         if (!tty_gone(tp))
  205                 tty_drain(tp, 1);
  206 
  207         ttydisc_close(tp);
  208 
  209         /* Free i/o queues now since they might be large. */
  210         ttyinq_free(&tp->t_inq);
  211         tp->t_inlow = 0;
  212         ttyoutq_free(&tp->t_outq);
  213         tp->t_outlow = 0;
  214 
  215         knlist_clear(&tp->t_inpoll.si_note, 1);
  216         knlist_clear(&tp->t_outpoll.si_note, 1);
  217 
  218         if (!tty_gone(tp))
  219                 ttydevsw_close(tp);
  220 
  221         tp->t_flags &= ~TF_OPENCLOSE;
  222         cv_broadcast(&tp->t_dcdwait);
  223         tty_rel_free(tp);
  224 }
  225 
  226 /*
  227  * Operations that are exposed through the character device in /dev.
  228  */
  229 static int
  230 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
  231     struct thread *td)
  232 {
  233         struct tty *tp;
  234         int error;
  235 
  236         tp = dev->si_drv1;
  237         error = 0;
  238         tty_lock(tp);
  239         if (tty_gone(tp)) {
  240                 /* Device is already gone. */
  241                 tty_unlock(tp);
  242                 return (ENXIO);
  243         }
  244 
  245         /*
  246          * Block when other processes are currently opening or closing
  247          * the TTY.
  248          */
  249         while (tp->t_flags & TF_OPENCLOSE) {
  250                 error = tty_wait(tp, &tp->t_dcdwait);
  251                 if (error != 0) {
  252                         tty_unlock(tp);
  253                         return (error);
  254                 }
  255         }
  256         tp->t_flags |= TF_OPENCLOSE;
  257 
  258         /*
  259          * Make sure the "tty" and "cua" device cannot be opened at the
  260          * same time.  The console is a "tty" device.
  261          */
  262         if (TTY_CALLOUT(tp, dev)) {
  263                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
  264                         error = EBUSY;
  265                         goto done;
  266                 }
  267         } else {
  268                 if (tp->t_flags & TF_OPENED_OUT) {
  269                         error = EBUSY;
  270                         goto done;
  271                 }
  272         }
  273 
  274         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
  275                 error = EBUSY;
  276                 goto done;
  277         }
  278 
  279         if (!tty_opened(tp)) {
  280                 /* Set proper termios flags. */
  281                 if (TTY_CALLOUT(tp, dev))
  282                         tp->t_termios = tp->t_termios_init_out;
  283                 else
  284                         tp->t_termios = tp->t_termios_init_in;
  285                 ttydevsw_param(tp, &tp->t_termios);
  286                 /* Prevent modem control on callout devices and /dev/console. */
  287                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
  288                         tp->t_termios.c_cflag |= CLOCAL;
  289 
  290                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
  291 
  292                 error = ttydevsw_open(tp);
  293                 if (error != 0)
  294                         goto done;
  295 
  296                 ttydisc_open(tp);
  297                 tty_watermarks(tp); /* XXXGL: drops lock */
  298         }
  299 
  300         /* Wait for Carrier Detect. */
  301         if ((oflags & O_NONBLOCK) == 0 &&
  302             (tp->t_termios.c_cflag & CLOCAL) == 0) {
  303                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
  304                         error = tty_wait(tp, &tp->t_dcdwait);
  305                         if (error != 0)
  306                                 goto done;
  307                 }
  308         }
  309 
  310         if (dev == dev_console)
  311                 tp->t_flags |= TF_OPENED_CONS;
  312         else if (TTY_CALLOUT(tp, dev))
  313                 tp->t_flags |= TF_OPENED_OUT;
  314         else
  315                 tp->t_flags |= TF_OPENED_IN;
  316         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
  317             (tp->t_flags & TF_OPENED_OUT) == 0);
  318 
  319 done:   tp->t_flags &= ~TF_OPENCLOSE;
  320         cv_broadcast(&tp->t_dcdwait);
  321         ttydev_leave(tp);
  322 
  323         return (error);
  324 }
  325 
  326 static int
  327 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
  328     struct thread *td __unused)
  329 {
  330         struct tty *tp = dev->si_drv1;
  331 
  332         tty_lock(tp);
  333 
  334         /*
  335          * Don't actually close the device if it is being used as the
  336          * console.
  337          */
  338         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
  339             (tp->t_flags & TF_OPENED_OUT) == 0);
  340         if (dev == dev_console)
  341                 tp->t_flags &= ~TF_OPENED_CONS;
  342         else
  343                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
  344 
  345         if (tp->t_flags & TF_OPENED) {
  346                 tty_unlock(tp);
  347                 return (0);
  348         }
  349 
  350         /* If revoking, flush output now to avoid draining it later. */
  351         if (fflag & FREVOKE)
  352                 tty_flush(tp, FWRITE);
  353 
  354         tp->t_flags &= ~TF_EXCLUDE;
  355 
  356         /* Properly wake up threads that are stuck - revoke(). */
  357         tp->t_revokecnt++;
  358         tty_wakeup(tp, FREAD|FWRITE);
  359         cv_broadcast(&tp->t_bgwait);
  360         cv_broadcast(&tp->t_dcdwait);
  361 
  362         ttydev_leave(tp);
  363 
  364         return (0);
  365 }
  366 
  367 static __inline int
  368 tty_is_ctty(struct tty *tp, struct proc *p)
  369 {
  370 
  371         tty_lock_assert(tp, MA_OWNED);
  372 
  373         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
  374 }
  375 
  376 int
  377 tty_wait_background(struct tty *tp, struct thread *td, int sig)
  378 {
  379         struct proc *p = td->td_proc;
  380         struct pgrp *pg;
  381         ksiginfo_t ksi;
  382         int error;
  383 
  384         MPASS(sig == SIGTTIN || sig == SIGTTOU);
  385         tty_lock_assert(tp, MA_OWNED);
  386 
  387         for (;;) {
  388                 PROC_LOCK(p);
  389                 /*
  390                  * The process should only sleep, when:
  391                  * - This terminal is the controling terminal
  392                  * - Its process group is not the foreground process
  393                  *   group
  394                  * - The parent process isn't waiting for the child to
  395                  *   exit
  396                  * - the signal to send to the process isn't masked
  397                  */
  398                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
  399                         /* Allow the action to happen. */
  400                         PROC_UNLOCK(p);
  401                         return (0);
  402                 }
  403 
  404                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
  405                     SIGISMEMBER(td->td_sigmask, sig)) {
  406                         /* Only allow them in write()/ioctl(). */
  407                         PROC_UNLOCK(p);
  408                         return (sig == SIGTTOU ? 0 : EIO);
  409                 }
  410 
  411                 pg = p->p_pgrp;
  412                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
  413                         /* Don't allow the action to happen. */
  414                         PROC_UNLOCK(p);
  415                         return (EIO);
  416                 }
  417                 PROC_UNLOCK(p);
  418 
  419                 /*
  420                  * Send the signal and sleep until we're the new
  421                  * foreground process group.
  422                  */
  423                 if (sig != 0) {
  424                         ksiginfo_init(&ksi);
  425                         ksi.ksi_code = SI_KERNEL;
  426                         ksi.ksi_signo = sig;
  427                         sig = 0;
  428                 }
  429                 PGRP_LOCK(pg);
  430                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
  431                 PGRP_UNLOCK(pg);
  432 
  433                 error = tty_wait(tp, &tp->t_bgwait);
  434                 if (error)
  435                         return (error);
  436         }
  437 }
  438 
  439 static int
  440 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
  441 {
  442         struct tty *tp = dev->si_drv1;
  443         int error;
  444 
  445         error = ttydev_enter(tp);
  446         if (error)
  447                 goto done;
  448         error = ttydisc_read(tp, uio, ioflag);
  449         tty_unlock(tp);
  450 
  451         /*
  452          * The read() call should not throw an error when the device is
  453          * being destroyed. Silently convert it to an EOF.
  454          */
  455 done:   if (error == ENXIO)
  456                 error = 0;
  457         return (error);
  458 }
  459 
  460 static int
  461 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  462 {
  463         struct tty *tp = dev->si_drv1;
  464         int error;
  465 
  466         error = ttydev_enter(tp);
  467         if (error)
  468                 return (error);
  469 
  470         if (tp->t_termios.c_lflag & TOSTOP) {
  471                 error = tty_wait_background(tp, curthread, SIGTTOU);
  472                 if (error)
  473                         goto done;
  474         }
  475 
  476         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  477                 /* Allow non-blocking writes to bypass serialization. */
  478                 error = ttydisc_write(tp, uio, ioflag);
  479         } else {
  480                 /* Serialize write() calls. */
  481                 while (tp->t_flags & TF_BUSY_OUT) {
  482                         error = tty_wait(tp, &tp->t_outserwait);
  483                         if (error)
  484                                 goto done;
  485                 }
  486 
  487                 tp->t_flags |= TF_BUSY_OUT;
  488                 error = ttydisc_write(tp, uio, ioflag);
  489                 tp->t_flags &= ~TF_BUSY_OUT;
  490                 cv_signal(&tp->t_outserwait);
  491         }
  492 
  493 done:   tty_unlock(tp);
  494         return (error);
  495 }
  496 
  497 static int
  498 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  499     struct thread *td)
  500 {
  501         struct tty *tp = dev->si_drv1;
  502         int error;
  503 
  504         error = ttydev_enter(tp);
  505         if (error)
  506                 return (error);
  507 
  508         switch (cmd) {
  509         case TIOCCBRK:
  510         case TIOCCONS:
  511         case TIOCDRAIN:
  512         case TIOCEXCL:
  513         case TIOCFLUSH:
  514         case TIOCNXCL:
  515         case TIOCSBRK:
  516         case TIOCSCTTY:
  517         case TIOCSETA:
  518         case TIOCSETAF:
  519         case TIOCSETAW:
  520         case TIOCSPGRP:
  521         case TIOCSTART:
  522         case TIOCSTAT:
  523         case TIOCSTI:
  524         case TIOCSTOP:
  525         case TIOCSWINSZ:
  526 #if 0
  527         case TIOCSDRAINWAIT:
  528         case TIOCSETD:
  529 #endif
  530 #ifdef COMPAT_43TTY
  531         case  TIOCLBIC:
  532         case  TIOCLBIS:
  533         case  TIOCLSET:
  534         case  TIOCSETC:
  535         case OTIOCSETD:
  536         case  TIOCSETN:
  537         case  TIOCSETP:
  538         case  TIOCSLTC:
  539 #endif /* COMPAT_43TTY */
  540                 /*
  541                  * If the ioctl() causes the TTY to be modified, let it
  542                  * wait in the background.
  543                  */
  544                 error = tty_wait_background(tp, curthread, SIGTTOU);
  545                 if (error)
  546                         goto done;
  547         }
  548 
  549         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  550                 struct termios *old = &tp->t_termios;
  551                 struct termios *new = (struct termios *)data;
  552                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  553                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  554                 int cc;
  555 
  556                 /*
  557                  * Lock state devices.  Just overwrite the values of the
  558                  * commands that are currently in use.
  559                  */
  560                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  561                     (new->c_iflag & ~lock->c_iflag);
  562                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  563                     (new->c_oflag & ~lock->c_oflag);
  564                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  565                     (new->c_cflag & ~lock->c_cflag);
  566                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  567                     (new->c_lflag & ~lock->c_lflag);
  568                 for (cc = 0; cc < NCCS; ++cc)
  569                         if (lock->c_cc[cc])
  570                                 new->c_cc[cc] = old->c_cc[cc];
  571                 if (lock->c_ispeed)
  572                         new->c_ispeed = old->c_ispeed;
  573                 if (lock->c_ospeed)
  574                         new->c_ospeed = old->c_ospeed;
  575         }
  576 
  577         error = tty_ioctl(tp, cmd, data, fflag, td);
  578 done:   tty_unlock(tp);
  579 
  580         return (error);
  581 }
  582 
  583 static int
  584 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  585 {
  586         struct tty *tp = dev->si_drv1;
  587         int error, revents = 0;
  588 
  589         error = ttydev_enter(tp);
  590         if (error)
  591                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  592 
  593         if (events & (POLLIN|POLLRDNORM)) {
  594                 /* See if we can read something. */
  595                 if (ttydisc_read_poll(tp) > 0)
  596                         revents |= events & (POLLIN|POLLRDNORM);
  597         }
  598 
  599         if (tp->t_flags & TF_ZOMBIE) {
  600                 /* Hangup flag on zombie state. */
  601                 revents |= POLLHUP;
  602         } else if (events & (POLLOUT|POLLWRNORM)) {
  603                 /* See if we can write something. */
  604                 if (ttydisc_write_poll(tp) > 0)
  605                         revents |= events & (POLLOUT|POLLWRNORM);
  606         }
  607 
  608         if (revents == 0) {
  609                 if (events & (POLLIN|POLLRDNORM))
  610                         selrecord(td, &tp->t_inpoll);
  611                 if (events & (POLLOUT|POLLWRNORM))
  612                         selrecord(td, &tp->t_outpoll);
  613         }
  614 
  615         tty_unlock(tp);
  616 
  617         return (revents);
  618 }
  619 
  620 static int
  621 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  622     int nprot, vm_memattr_t *memattr)
  623 {
  624         struct tty *tp = dev->si_drv1;
  625         int error;
  626 
  627         /* Handle mmap() through the driver. */
  628 
  629         error = ttydev_enter(tp);
  630         if (error)
  631                 return (-1);
  632         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
  633         tty_unlock(tp);
  634 
  635         return (error);
  636 }
  637 
  638 /*
  639  * kqueue support.
  640  */
  641 
  642 static void
  643 tty_kqops_read_detach(struct knote *kn)
  644 {
  645         struct tty *tp = kn->kn_hook;
  646 
  647         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  648 }
  649 
  650 static int
  651 tty_kqops_read_event(struct knote *kn, long hint __unused)
  652 {
  653         struct tty *tp = kn->kn_hook;
  654 
  655         tty_lock_assert(tp, MA_OWNED);
  656 
  657         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  658                 kn->kn_flags |= EV_EOF;
  659                 return (1);
  660         } else {
  661                 kn->kn_data = ttydisc_read_poll(tp);
  662                 return (kn->kn_data > 0);
  663         }
  664 }
  665 
  666 static void
  667 tty_kqops_write_detach(struct knote *kn)
  668 {
  669         struct tty *tp = kn->kn_hook;
  670 
  671         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  672 }
  673 
  674 static int
  675 tty_kqops_write_event(struct knote *kn, long hint __unused)
  676 {
  677         struct tty *tp = kn->kn_hook;
  678 
  679         tty_lock_assert(tp, MA_OWNED);
  680 
  681         if (tty_gone(tp)) {
  682                 kn->kn_flags |= EV_EOF;
  683                 return (1);
  684         } else {
  685                 kn->kn_data = ttydisc_write_poll(tp);
  686                 return (kn->kn_data > 0);
  687         }
  688 }
  689 
  690 static struct filterops tty_kqops_read = {
  691         .f_isfd = 1,
  692         .f_detach = tty_kqops_read_detach,
  693         .f_event = tty_kqops_read_event,
  694 };
  695 
  696 static struct filterops tty_kqops_write = {
  697         .f_isfd = 1,
  698         .f_detach = tty_kqops_write_detach,
  699         .f_event = tty_kqops_write_event,
  700 };
  701 
  702 static int
  703 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  704 {
  705         struct tty *tp = dev->si_drv1;
  706         int error;
  707 
  708         error = ttydev_enter(tp);
  709         if (error)
  710                 return (error);
  711 
  712         switch (kn->kn_filter) {
  713         case EVFILT_READ:
  714                 kn->kn_hook = tp;
  715                 kn->kn_fop = &tty_kqops_read;
  716                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  717                 break;
  718         case EVFILT_WRITE:
  719                 kn->kn_hook = tp;
  720                 kn->kn_fop = &tty_kqops_write;
  721                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  722                 break;
  723         default:
  724                 error = EINVAL;
  725                 break;
  726         }
  727 
  728         tty_unlock(tp);
  729         return (error);
  730 }
  731 
  732 static struct cdevsw ttydev_cdevsw = {
  733         .d_version      = D_VERSION,
  734         .d_open         = ttydev_open,
  735         .d_close        = ttydev_close,
  736         .d_read         = ttydev_read,
  737         .d_write        = ttydev_write,
  738         .d_ioctl        = ttydev_ioctl,
  739         .d_kqfilter     = ttydev_kqfilter,
  740         .d_poll         = ttydev_poll,
  741         .d_mmap         = ttydev_mmap,
  742         .d_name         = "ttydev",
  743         .d_flags        = D_TTY,
  744 };
  745 
  746 /*
  747  * Init/lock-state devices
  748  */
  749 
  750 static int
  751 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
  752     struct thread *td)
  753 {
  754         struct tty *tp;
  755         int error;
  756 
  757         tp = dev->si_drv1;
  758         error = 0;
  759         tty_lock(tp);
  760         if (tty_gone(tp))
  761                 error = ENODEV;
  762         tty_unlock(tp);
  763 
  764         return (error);
  765 }
  766 
  767 static int
  768 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
  769     struct thread *td __unused)
  770 {
  771 
  772         return (0);
  773 }
  774 
  775 static int
  776 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
  777     int ioflag __unused)
  778 {
  779 
  780         return (ENODEV);
  781 }
  782 
  783 static int
  784 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  785     struct thread *td)
  786 {
  787         struct tty *tp = dev->si_drv1;
  788         int error;
  789 
  790         tty_lock(tp);
  791         if (tty_gone(tp)) {
  792                 error = ENODEV;
  793                 goto done;
  794         }
  795 
  796         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
  797         if (error != ENOIOCTL)
  798                 goto done;
  799         error = 0;
  800 
  801         switch (cmd) {
  802         case TIOCGETA:
  803                 /* Obtain terminal flags through tcgetattr(). */
  804                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  805                 break;
  806         case TIOCSETA:
  807                 /* Set terminal flags through tcsetattr(). */
  808                 error = priv_check(td, PRIV_TTY_SETA);
  809                 if (error)
  810                         break;
  811                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  812                 break;
  813         case TIOCGETD:
  814                 *(int *)data = TTYDISC;
  815                 break;
  816         case TIOCGWINSZ:
  817                 bzero(data, sizeof(struct winsize));
  818                 break;
  819         default:
  820                 error = ENOTTY;
  821         }
  822 
  823 done:   tty_unlock(tp);
  824         return (error);
  825 }
  826 
  827 static struct cdevsw ttyil_cdevsw = {
  828         .d_version      = D_VERSION,
  829         .d_open         = ttyil_open,
  830         .d_close        = ttyil_close,
  831         .d_read         = ttyil_rdwr,
  832         .d_write        = ttyil_rdwr,
  833         .d_ioctl        = ttyil_ioctl,
  834         .d_name         = "ttyil",
  835         .d_flags        = D_TTY,
  836 };
  837 
  838 static void
  839 tty_init_termios(struct tty *tp)
  840 {
  841         struct termios *t = &tp->t_termios_init_in;
  842 
  843         t->c_cflag = TTYDEF_CFLAG;
  844         t->c_iflag = TTYDEF_IFLAG;
  845         t->c_lflag = TTYDEF_LFLAG;
  846         t->c_oflag = TTYDEF_OFLAG;
  847         t->c_ispeed = TTYDEF_SPEED;
  848         t->c_ospeed = TTYDEF_SPEED;
  849         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  850 
  851         tp->t_termios_init_out = *t;
  852 }
  853 
  854 void
  855 tty_init_console(struct tty *tp, speed_t s)
  856 {
  857         struct termios *ti = &tp->t_termios_init_in;
  858         struct termios *to = &tp->t_termios_init_out;
  859 
  860         if (s != 0) {
  861                 ti->c_ispeed = ti->c_ospeed = s;
  862                 to->c_ispeed = to->c_ospeed = s;
  863         }
  864 
  865         ti->c_cflag |= CLOCAL;
  866         to->c_cflag |= CLOCAL;
  867 }
  868 
  869 /*
  870  * Standard device routine implementations, mostly meant for
  871  * pseudo-terminal device drivers. When a driver creates a new terminal
  872  * device class, missing routines are patched.
  873  */
  874 
  875 static int
  876 ttydevsw_defopen(struct tty *tp __unused)
  877 {
  878 
  879         return (0);
  880 }
  881 
  882 static void
  883 ttydevsw_defclose(struct tty *tp __unused)
  884 {
  885 
  886 }
  887 
  888 static void
  889 ttydevsw_defoutwakeup(struct tty *tp __unused)
  890 {
  891 
  892         panic("Terminal device has output, while not implemented");
  893 }
  894 
  895 static void
  896 ttydevsw_definwakeup(struct tty *tp __unused)
  897 {
  898 
  899 }
  900 
  901 static int
  902 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
  903     caddr_t data __unused, struct thread *td __unused)
  904 {
  905 
  906         return (ENOIOCTL);
  907 }
  908 
  909 static int
  910 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
  911     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
  912 {
  913 
  914         return (ENOIOCTL);
  915 }
  916 
  917 static int
  918 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
  919 {
  920 
  921         /*
  922          * Allow the baud rate to be adjusted for pseudo-devices, but at
  923          * least restrict it to 115200 to prevent excessive buffer
  924          * usage.  Also disallow 0, to prevent foot shooting.
  925          */
  926         if (t->c_ispeed < B50)
  927                 t->c_ispeed = B50;
  928         else if (t->c_ispeed > B115200)
  929                 t->c_ispeed = B115200;
  930         if (t->c_ospeed < B50)
  931                 t->c_ospeed = B50;
  932         else if (t->c_ospeed > B115200)
  933                 t->c_ospeed = B115200;
  934         t->c_cflag |= CREAD;
  935 
  936         return (0);
  937 }
  938 
  939 static int
  940 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
  941     int sigoff __unused)
  942 {
  943 
  944         /* Simulate a carrier to make the TTY layer happy. */
  945         return (SER_DCD);
  946 }
  947 
  948 static int
  949 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
  950     vm_paddr_t *paddr __unused, int nprot __unused,
  951     vm_memattr_t *memattr __unused)
  952 {
  953 
  954         return (-1);
  955 }
  956 
  957 static void
  958 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
  959 {
  960 
  961 }
  962 
  963 static void
  964 ttydevsw_deffree(void *softc __unused)
  965 {
  966 
  967         panic("Terminal device freed without a free-handler");
  968 }
  969 
  970 static bool
  971 ttydevsw_defbusy(struct tty *tp __unused)
  972 {
  973 
  974         return (FALSE);
  975 }
  976 
  977 /*
  978  * TTY allocation and deallocation. TTY devices can be deallocated when
  979  * the driver doesn't use it anymore, when the TTY isn't a session's
  980  * controlling TTY and when the device node isn't opened through devfs.
  981  */
  982 
  983 struct tty *
  984 tty_alloc(struct ttydevsw *tsw, void *sc)
  985 {
  986 
  987         return (tty_alloc_mutex(tsw, sc, NULL));
  988 }
  989 
  990 struct tty *
  991 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
  992 {
  993         struct tty *tp;
  994 
  995         /* Make sure the driver defines all routines. */
  996 #define PATCH_FUNC(x) do {                              \
  997         if (tsw->tsw_ ## x == NULL)                     \
  998                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
  999 } while (0)
 1000         PATCH_FUNC(open);
 1001         PATCH_FUNC(close);
 1002         PATCH_FUNC(outwakeup);
 1003         PATCH_FUNC(inwakeup);
 1004         PATCH_FUNC(ioctl);
 1005         PATCH_FUNC(cioctl);
 1006         PATCH_FUNC(param);
 1007         PATCH_FUNC(modem);
 1008         PATCH_FUNC(mmap);
 1009         PATCH_FUNC(pktnotify);
 1010         PATCH_FUNC(free);
 1011         PATCH_FUNC(busy);
 1012 #undef PATCH_FUNC
 1013 
 1014         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
 1015         tp->t_devsw = tsw;
 1016         tp->t_devswsoftc = sc;
 1017         tp->t_flags = tsw->tsw_flags;
 1018 
 1019         tty_init_termios(tp);
 1020 
 1021         cv_init(&tp->t_inwait, "ttyin");
 1022         cv_init(&tp->t_outwait, "ttyout");
 1023         cv_init(&tp->t_outserwait, "ttyosr");
 1024         cv_init(&tp->t_bgwait, "ttybg");
 1025         cv_init(&tp->t_dcdwait, "ttydcd");
 1026 
 1027         /* Allow drivers to use a custom mutex to lock the TTY. */
 1028         if (mutex != NULL) {
 1029                 tp->t_mtx = mutex;
 1030         } else {
 1031                 tp->t_mtx = &tp->t_mtxobj;
 1032                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
 1033         }
 1034 
 1035         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 1036         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 1037 
 1038         return (tp);
 1039 }
 1040 
 1041 static void
 1042 tty_dealloc(void *arg)
 1043 {
 1044         struct tty *tp = arg;
 1045 
 1046         /*
 1047          * ttyydev_leave() usually frees the i/o queues earlier, but it is
 1048          * not always called between queue allocation and here.  The queues
 1049          * may be allocated by ioctls on a pty control device without the
 1050          * corresponding pty slave device ever being open, or after it is
 1051          * closed.
 1052          */
 1053         ttyinq_free(&tp->t_inq);
 1054         ttyoutq_free(&tp->t_outq);
 1055         seldrain(&tp->t_inpoll);
 1056         seldrain(&tp->t_outpoll);
 1057         knlist_destroy(&tp->t_inpoll.si_note);
 1058         knlist_destroy(&tp->t_outpoll.si_note);
 1059 
 1060         cv_destroy(&tp->t_inwait);
 1061         cv_destroy(&tp->t_outwait);
 1062         cv_destroy(&tp->t_bgwait);
 1063         cv_destroy(&tp->t_dcdwait);
 1064         cv_destroy(&tp->t_outserwait);
 1065 
 1066         if (tp->t_mtx == &tp->t_mtxobj)
 1067                 mtx_destroy(&tp->t_mtxobj);
 1068         ttydevsw_free(tp);
 1069         free(tp, M_TTY);
 1070 }
 1071 
 1072 static void
 1073 tty_rel_free(struct tty *tp)
 1074 {
 1075         struct cdev *dev;
 1076 
 1077         tty_lock_assert(tp, MA_OWNED);
 1078 
 1079 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1080         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1081                 /* TTY is still in use. */
 1082                 tty_unlock(tp);
 1083                 return;
 1084         }
 1085 
 1086         /* TTY can be deallocated. */
 1087         dev = tp->t_dev;
 1088         tp->t_dev = NULL;
 1089         tty_unlock(tp);
 1090 
 1091         if (dev != NULL) {
 1092                 sx_xlock(&tty_list_sx);
 1093                 TAILQ_REMOVE(&tty_list, tp, t_list);
 1094                 tty_list_count--;
 1095                 sx_xunlock(&tty_list_sx);
 1096                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1097         }
 1098 }
 1099 
 1100 void
 1101 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1102 {
 1103 
 1104         MPASS(tp->t_sessioncnt > 0);
 1105         tty_lock_assert(tp, MA_OWNED);
 1106 
 1107         if (tp->t_pgrp == pg)
 1108                 tp->t_pgrp = NULL;
 1109 
 1110         tty_unlock(tp);
 1111 }
 1112 
 1113 void
 1114 tty_rel_sess(struct tty *tp, struct session *sess)
 1115 {
 1116 
 1117         MPASS(tp->t_sessioncnt > 0);
 1118 
 1119         /* Current session has left. */
 1120         if (tp->t_session == sess) {
 1121                 tp->t_session = NULL;
 1122                 MPASS(tp->t_pgrp == NULL);
 1123         }
 1124         tp->t_sessioncnt--;
 1125         tty_rel_free(tp);
 1126 }
 1127 
 1128 void
 1129 tty_rel_gone(struct tty *tp)
 1130 {
 1131 
 1132         MPASS(!tty_gone(tp));
 1133 
 1134         /* Simulate carrier removal. */
 1135         ttydisc_modem(tp, 0);
 1136 
 1137         /* Wake up all blocked threads. */
 1138         tty_wakeup(tp, FREAD|FWRITE);
 1139         cv_broadcast(&tp->t_bgwait);
 1140         cv_broadcast(&tp->t_dcdwait);
 1141 
 1142         tp->t_flags |= TF_GONE;
 1143         tty_rel_free(tp);
 1144 }
 1145 
 1146 /*
 1147  * Exposing information about current TTY's through sysctl
 1148  */
 1149 
 1150 static void
 1151 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1152 {
 1153 
 1154         tty_lock_assert(tp, MA_OWNED);
 1155 
 1156         xt->xt_size = sizeof(struct xtty);
 1157         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1158         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1159         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1160         xt->xt_inlow = tp->t_inlow;
 1161         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1162         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1163         xt->xt_outlow = tp->t_outlow;
 1164         xt->xt_column = tp->t_column;
 1165         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1166         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1167         xt->xt_flags = tp->t_flags;
 1168         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1169 }
 1170 
 1171 static int
 1172 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1173 {
 1174         unsigned long lsize;
 1175         struct xtty *xtlist, *xt;
 1176         struct tty *tp;
 1177         int error;
 1178 
 1179         sx_slock(&tty_list_sx);
 1180         lsize = tty_list_count * sizeof(struct xtty);
 1181         if (lsize == 0) {
 1182                 sx_sunlock(&tty_list_sx);
 1183                 return (0);
 1184         }
 1185 
 1186         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1187 
 1188         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1189                 tty_lock(tp);
 1190                 tty_to_xtty(tp, xt);
 1191                 tty_unlock(tp);
 1192                 xt++;
 1193         }
 1194         sx_sunlock(&tty_list_sx);
 1195 
 1196         error = SYSCTL_OUT(req, xtlist, lsize);
 1197         free(xtlist, M_TTY);
 1198         return (error);
 1199 }
 1200 
 1201 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1202         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1203 
 1204 /*
 1205  * Device node creation. Device has been set up, now we can expose it to
 1206  * the user.
 1207  */
 1208 
 1209 int
 1210 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
 1211     const char *fmt, ...)
 1212 {
 1213         va_list ap;
 1214         struct make_dev_args args;
 1215         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
 1216         const char *prefix = "tty";
 1217         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1218         uid_t uid;
 1219         gid_t gid;
 1220         mode_t mode;
 1221         int error;
 1222 
 1223         /* Remove "tty" prefix from devices like PTY's. */
 1224         if (tp->t_flags & TF_NOPREFIX)
 1225                 prefix = "";
 1226 
 1227         va_start(ap, fmt);
 1228         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1229         va_end(ap);
 1230 
 1231         if (cred == NULL) {
 1232                 /* System device. */
 1233                 uid = UID_ROOT;
 1234                 gid = GID_WHEEL;
 1235                 mode = S_IRUSR|S_IWUSR;
 1236         } else {
 1237                 /* User device. */
 1238                 uid = cred->cr_ruid;
 1239                 gid = GID_TTY;
 1240                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1241         }
 1242 
 1243         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
 1244         flags |= MAKEDEV_CHECKNAME;
 1245 
 1246         /* Master call-in device. */
 1247         make_dev_args_init(&args);
 1248         args.mda_flags = flags;
 1249         args.mda_devsw = &ttydev_cdevsw;
 1250         args.mda_cr = cred;
 1251         args.mda_uid = uid;
 1252         args.mda_gid = gid;
 1253         args.mda_mode = mode;
 1254         args.mda_si_drv1 = tp;
 1255         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
 1256         if (error != 0)
 1257                 return (error);
 1258         tp->t_dev = dev;
 1259 
 1260         init = lock = cua = cinit = clock = NULL;
 1261 
 1262         /* Slave call-in devices. */
 1263         if (tp->t_flags & TF_INITLOCK) {
 1264                 args.mda_devsw = &ttyil_cdevsw;
 1265                 args.mda_unit = TTYUNIT_INIT;
 1266                 args.mda_si_drv1 = tp;
 1267                 args.mda_si_drv2 = &tp->t_termios_init_in;
 1268                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
 1269                 if (error != 0)
 1270                         goto fail;
 1271                 dev_depends(dev, init);
 1272 
 1273                 args.mda_unit = TTYUNIT_LOCK;
 1274                 args.mda_si_drv2 = &tp->t_termios_lock_in;
 1275                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
 1276                 if (error != 0)
 1277                         goto fail;
 1278                 dev_depends(dev, lock);
 1279         }
 1280 
 1281         /* Call-out devices. */
 1282         if (tp->t_flags & TF_CALLOUT) {
 1283                 make_dev_args_init(&args);
 1284                 args.mda_flags = flags;
 1285                 args.mda_devsw = &ttydev_cdevsw;
 1286                 args.mda_cr = cred;
 1287                 args.mda_uid = UID_UUCP;
 1288                 args.mda_gid = GID_DIALER;
 1289                 args.mda_mode = 0660;
 1290                 args.mda_unit = TTYUNIT_CALLOUT;
 1291                 args.mda_si_drv1 = tp;
 1292                 error = make_dev_s(&args, &cua, "cua%s", name);
 1293                 if (error != 0)
 1294                         goto fail;
 1295                 dev_depends(dev, cua);
 1296 
 1297                 /* Slave call-out devices. */
 1298                 if (tp->t_flags & TF_INITLOCK) {
 1299                         args.mda_devsw = &ttyil_cdevsw;
 1300                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
 1301                         args.mda_si_drv2 = &tp->t_termios_init_out;
 1302                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
 1303                         if (error != 0)
 1304                                 goto fail;
 1305                         dev_depends(dev, cinit);
 1306 
 1307                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
 1308                         args.mda_si_drv2 = &tp->t_termios_lock_out;
 1309                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
 1310                         if (error != 0)
 1311                                 goto fail;
 1312                         dev_depends(dev, clock);
 1313                 }
 1314         }
 1315 
 1316         sx_xlock(&tty_list_sx);
 1317         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
 1318         tty_list_count++;
 1319         sx_xunlock(&tty_list_sx);
 1320 
 1321         return (0);
 1322 
 1323 fail:
 1324         destroy_dev(dev);
 1325         if (init)
 1326                 destroy_dev(init);
 1327         if (lock)
 1328                 destroy_dev(lock);
 1329         if (cinit)
 1330                 destroy_dev(cinit);
 1331         if (clock)
 1332                 destroy_dev(clock);
 1333 
 1334         return (error);
 1335 }
 1336 
 1337 /*
 1338  * Signalling processes.
 1339  */
 1340 
 1341 void
 1342 tty_signal_sessleader(struct tty *tp, int sig)
 1343 {
 1344         struct proc *p;
 1345 
 1346         tty_lock_assert(tp, MA_OWNED);
 1347         MPASS(sig >= 1 && sig < NSIG);
 1348 
 1349         /* Make signals start output again. */
 1350         tp->t_flags &= ~TF_STOPPED;
 1351 
 1352         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1353                 p = tp->t_session->s_leader;
 1354                 PROC_LOCK(p);
 1355                 kern_psignal(p, sig);
 1356                 PROC_UNLOCK(p);
 1357         }
 1358 }
 1359 
 1360 void
 1361 tty_signal_pgrp(struct tty *tp, int sig)
 1362 {
 1363         ksiginfo_t ksi;
 1364 
 1365         tty_lock_assert(tp, MA_OWNED);
 1366         MPASS(sig >= 1 && sig < NSIG);
 1367 
 1368         /* Make signals start output again. */
 1369         tp->t_flags &= ~TF_STOPPED;
 1370 
 1371         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1372                 tty_info(tp);
 1373         if (tp->t_pgrp != NULL) {
 1374                 ksiginfo_init(&ksi);
 1375                 ksi.ksi_signo = sig;
 1376                 ksi.ksi_code = SI_KERNEL;
 1377                 PGRP_LOCK(tp->t_pgrp);
 1378                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1379                 PGRP_UNLOCK(tp->t_pgrp);
 1380         }
 1381 }
 1382 
 1383 void
 1384 tty_wakeup(struct tty *tp, int flags)
 1385 {
 1386 
 1387         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1388                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1389 
 1390         if (flags & FWRITE) {
 1391                 cv_broadcast(&tp->t_outwait);
 1392                 selwakeup(&tp->t_outpoll);
 1393                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1394         }
 1395         if (flags & FREAD) {
 1396                 cv_broadcast(&tp->t_inwait);
 1397                 selwakeup(&tp->t_inpoll);
 1398                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1399         }
 1400 }
 1401 
 1402 int
 1403 tty_wait(struct tty *tp, struct cv *cv)
 1404 {
 1405         int error;
 1406         int revokecnt = tp->t_revokecnt;
 1407 
 1408         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1409         MPASS(!tty_gone(tp));
 1410 
 1411         error = cv_wait_sig(cv, tp->t_mtx);
 1412 
 1413         /* Bail out when the device slipped away. */
 1414         if (tty_gone(tp))
 1415                 return (ENXIO);
 1416 
 1417         /* Restart the system call when we may have been revoked. */
 1418         if (tp->t_revokecnt != revokecnt)
 1419                 return (ERESTART);
 1420 
 1421         return (error);
 1422 }
 1423 
 1424 int
 1425 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1426 {
 1427         int error;
 1428         int revokecnt = tp->t_revokecnt;
 1429 
 1430         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1431         MPASS(!tty_gone(tp));
 1432 
 1433         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1434 
 1435         /* Bail out when the device slipped away. */
 1436         if (tty_gone(tp))
 1437                 return (ENXIO);
 1438 
 1439         /* Restart the system call when we may have been revoked. */
 1440         if (tp->t_revokecnt != revokecnt)
 1441                 return (ERESTART);
 1442 
 1443         return (error);
 1444 }
 1445 
 1446 void
 1447 tty_flush(struct tty *tp, int flags)
 1448 {
 1449 
 1450         if (flags & FWRITE) {
 1451                 tp->t_flags &= ~TF_HIWAT_OUT;
 1452                 ttyoutq_flush(&tp->t_outq);
 1453                 tty_wakeup(tp, FWRITE);
 1454                 if (!tty_gone(tp)) {
 1455                         ttydevsw_outwakeup(tp);
 1456                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1457                 }
 1458         }
 1459         if (flags & FREAD) {
 1460                 tty_hiwat_in_unblock(tp);
 1461                 ttyinq_flush(&tp->t_inq);
 1462                 tty_wakeup(tp, FREAD);
 1463                 if (!tty_gone(tp)) {
 1464                         ttydevsw_inwakeup(tp);
 1465                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1466                 }
 1467         }
 1468 }
 1469 
 1470 void
 1471 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
 1472 {
 1473 
 1474         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
 1475                 return;
 1476         tp->t_winsize = *wsz;
 1477         tty_signal_pgrp(tp, SIGWINCH);
 1478 }
 1479 
 1480 static int
 1481 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1482     struct thread *td)
 1483 {
 1484         int error;
 1485 
 1486         switch (cmd) {
 1487         /*
 1488          * Modem commands.
 1489          * The SER_* and TIOCM_* flags are the same, but one bit
 1490          * shifted. I don't know why.
 1491          */
 1492         case TIOCSDTR:
 1493                 ttydevsw_modem(tp, SER_DTR, 0);
 1494                 return (0);
 1495         case TIOCCDTR:
 1496                 ttydevsw_modem(tp, 0, SER_DTR);
 1497                 return (0);
 1498         case TIOCMSET: {
 1499                 int bits = *(int *)data;
 1500                 ttydevsw_modem(tp,
 1501                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1502                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1503                 return (0);
 1504         }
 1505         case TIOCMBIS: {
 1506                 int bits = *(int *)data;
 1507                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1508                 return (0);
 1509         }
 1510         case TIOCMBIC: {
 1511                 int bits = *(int *)data;
 1512                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1513                 return (0);
 1514         }
 1515         case TIOCMGET:
 1516                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1517                 return (0);
 1518 
 1519         case FIOASYNC:
 1520                 if (*(int *)data)
 1521                         tp->t_flags |= TF_ASYNC;
 1522                 else
 1523                         tp->t_flags &= ~TF_ASYNC;
 1524                 return (0);
 1525         case FIONBIO:
 1526                 /* This device supports non-blocking operation. */
 1527                 return (0);
 1528         case FIONREAD:
 1529                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1530                 return (0);
 1531         case FIONWRITE:
 1532         case TIOCOUTQ:
 1533                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1534                 return (0);
 1535         case FIOSETOWN:
 1536                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1537                         /* Not allowed to set ownership. */
 1538                         return (ENOTTY);
 1539 
 1540                 /* Temporarily unlock the TTY to set ownership. */
 1541                 tty_unlock(tp);
 1542                 error = fsetown(*(int *)data, &tp->t_sigio);
 1543                 tty_lock(tp);
 1544                 return (error);
 1545         case FIOGETOWN:
 1546                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1547                         /* Not allowed to set ownership. */
 1548                         return (ENOTTY);
 1549 
 1550                 /* Get ownership. */
 1551                 *(int *)data = fgetown(&tp->t_sigio);
 1552                 return (0);
 1553         case TIOCGETA:
 1554                 /* Obtain terminal flags through tcgetattr(). */
 1555                 *(struct termios*)data = tp->t_termios;
 1556                 return (0);
 1557         case TIOCSETA:
 1558         case TIOCSETAW:
 1559         case TIOCSETAF: {
 1560                 struct termios *t = data;
 1561 
 1562                 /*
 1563                  * Who makes up these funny rules? According to POSIX,
 1564                  * input baud rate is set equal to the output baud rate
 1565                  * when zero.
 1566                  */
 1567                 if (t->c_ispeed == 0)
 1568                         t->c_ispeed = t->c_ospeed;
 1569 
 1570                 /* Discard any unsupported bits. */
 1571                 t->c_iflag &= TTYSUP_IFLAG;
 1572                 t->c_oflag &= TTYSUP_OFLAG;
 1573                 t->c_lflag &= TTYSUP_LFLAG;
 1574                 t->c_cflag &= TTYSUP_CFLAG;
 1575 
 1576                 /* Set terminal flags through tcsetattr(). */
 1577                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1578                         error = tty_drain(tp, 0);
 1579                         if (error)
 1580                                 return (error);
 1581                         if (cmd == TIOCSETAF)
 1582                                 tty_flush(tp, FREAD);
 1583                 }
 1584 
 1585                 /*
 1586                  * Only call param() when the flags really change.
 1587                  */
 1588                 if ((t->c_cflag & CIGNORE) == 0 &&
 1589                     (tp->t_termios.c_cflag != t->c_cflag ||
 1590                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
 1591                     (IXON|IXOFF|IXANY)) ||
 1592                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1593                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1594                         error = ttydevsw_param(tp, t);
 1595                         if (error)
 1596                                 return (error);
 1597 
 1598                         /* XXX: CLOCAL? */
 1599 
 1600                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1601                         tp->t_termios.c_ispeed = t->c_ispeed;
 1602                         tp->t_termios.c_ospeed = t->c_ospeed;
 1603 
 1604                         /* Baud rate has changed - update watermarks. */
 1605                         tty_watermarks(tp);
 1606                 }
 1607 
 1608                 /* Copy new non-device driver parameters. */
 1609                 tp->t_termios.c_iflag = t->c_iflag;
 1610                 tp->t_termios.c_oflag = t->c_oflag;
 1611                 tp->t_termios.c_lflag = t->c_lflag;
 1612                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1613 
 1614                 ttydisc_optimize(tp);
 1615 
 1616                 if ((t->c_lflag & ICANON) == 0) {
 1617                         /*
 1618                          * When in non-canonical mode, wake up all
 1619                          * readers. Canonicalize any partial input. VMIN
 1620                          * and VTIME could also be adjusted.
 1621                          */
 1622                         ttyinq_canonicalize(&tp->t_inq);
 1623                         tty_wakeup(tp, FREAD);
 1624                 }
 1625 
 1626                 /*
 1627                  * For packet mode: notify the PTY consumer that VSTOP
 1628                  * and VSTART may have been changed.
 1629                  */
 1630                 if (tp->t_termios.c_iflag & IXON &&
 1631                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1632                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1633                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1634                 else
 1635                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1636                 return (0);
 1637         }
 1638         case TIOCGETD:
 1639                 /* For compatibility - we only support TTYDISC. */
 1640                 *(int *)data = TTYDISC;
 1641                 return (0);
 1642         case TIOCGPGRP:
 1643                 if (!tty_is_ctty(tp, td->td_proc))
 1644                         return (ENOTTY);
 1645 
 1646                 if (tp->t_pgrp != NULL)
 1647                         *(int *)data = tp->t_pgrp->pg_id;
 1648                 else
 1649                         *(int *)data = NO_PID;
 1650                 return (0);
 1651         case TIOCGSID:
 1652                 if (!tty_is_ctty(tp, td->td_proc))
 1653                         return (ENOTTY);
 1654 
 1655                 MPASS(tp->t_session);
 1656                 *(int *)data = tp->t_session->s_sid;
 1657                 return (0);
 1658         case TIOCSCTTY: {
 1659                 struct proc *p = td->td_proc;
 1660 
 1661                 /* XXX: This looks awful. */
 1662                 tty_unlock(tp);
 1663                 sx_xlock(&proctree_lock);
 1664                 tty_lock(tp);
 1665 
 1666                 if (!SESS_LEADER(p)) {
 1667                         /* Only the session leader may do this. */
 1668                         sx_xunlock(&proctree_lock);
 1669                         return (EPERM);
 1670                 }
 1671 
 1672                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1673                         /* This is already our controlling TTY. */
 1674                         sx_xunlock(&proctree_lock);
 1675                         return (0);
 1676                 }
 1677 
 1678                 if (p->p_session->s_ttyp != NULL ||
 1679                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1680                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1681                         /*
 1682                          * There is already a relation between a TTY and
 1683                          * a session, or the caller is not the session
 1684                          * leader.
 1685                          *
 1686                          * Allow the TTY to be stolen when the vnode is
 1687                          * invalid, but the reference to the TTY is
 1688                          * still active.  This allows immediate reuse of
 1689                          * TTYs of which the session leader has been
 1690                          * killed or the TTY revoked.
 1691                          */
 1692                         sx_xunlock(&proctree_lock);
 1693                         return (EPERM);
 1694                 }
 1695 
 1696                 /* Connect the session to the TTY. */
 1697                 tp->t_session = p->p_session;
 1698                 tp->t_session->s_ttyp = tp;
 1699                 tp->t_sessioncnt++;
 1700                 sx_xunlock(&proctree_lock);
 1701 
 1702                 /* Assign foreground process group. */
 1703                 tp->t_pgrp = p->p_pgrp;
 1704                 PROC_LOCK(p);
 1705                 p->p_flag |= P_CONTROLT;
 1706                 PROC_UNLOCK(p);
 1707 
 1708                 return (0);
 1709         }
 1710         case TIOCSPGRP: {
 1711                 struct pgrp *pg;
 1712 
 1713                 /*
 1714                  * XXX: Temporarily unlock the TTY to locate the process
 1715                  * group. This code would be lot nicer if we would ever
 1716                  * decompose proctree_lock.
 1717                  */
 1718                 tty_unlock(tp);
 1719                 sx_slock(&proctree_lock);
 1720                 pg = pgfind(*(int *)data);
 1721                 if (pg != NULL)
 1722                         PGRP_UNLOCK(pg);
 1723                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1724                         sx_sunlock(&proctree_lock);
 1725                         tty_lock(tp);
 1726                         return (EPERM);
 1727                 }
 1728                 tty_lock(tp);
 1729 
 1730                 /*
 1731                  * Determine if this TTY is the controlling TTY after
 1732                  * relocking the TTY.
 1733                  */
 1734                 if (!tty_is_ctty(tp, td->td_proc)) {
 1735                         sx_sunlock(&proctree_lock);
 1736                         return (ENOTTY);
 1737                 }
 1738                 tp->t_pgrp = pg;
 1739                 sx_sunlock(&proctree_lock);
 1740 
 1741                 /* Wake up the background process groups. */
 1742                 cv_broadcast(&tp->t_bgwait);
 1743                 return (0);
 1744         }
 1745         case TIOCFLUSH: {
 1746                 int flags = *(int *)data;
 1747 
 1748                 if (flags == 0)
 1749                         flags = (FREAD|FWRITE);
 1750                 else
 1751                         flags &= (FREAD|FWRITE);
 1752                 tty_flush(tp, flags);
 1753                 return (0);
 1754         }
 1755         case TIOCDRAIN:
 1756                 /* Drain TTY output. */
 1757                 return tty_drain(tp, 0);
 1758         case TIOCCONS:
 1759                 /* Set terminal as console TTY. */
 1760                 if (*(int *)data) {
 1761                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1762                         if (error)
 1763                                 return (error);
 1764 
 1765                         /*
 1766                          * XXX: constty should really need to be locked!
 1767                          * XXX: allow disconnected constty's to be stolen!
 1768                          */
 1769 
 1770                         if (constty == tp)
 1771                                 return (0);
 1772                         if (constty != NULL)
 1773                                 return (EBUSY);
 1774 
 1775                         tty_unlock(tp);
 1776                         constty_set(tp);
 1777                         tty_lock(tp);
 1778                 } else if (constty == tp) {
 1779                         constty_clear();
 1780                 }
 1781                 return (0);
 1782         case TIOCGWINSZ:
 1783                 /* Obtain window size. */
 1784                 *(struct winsize*)data = tp->t_winsize;
 1785                 return (0);
 1786         case TIOCSWINSZ:
 1787                 /* Set window size. */
 1788                 tty_set_winsize(tp, data);
 1789                 return (0);
 1790         case TIOCEXCL:
 1791                 tp->t_flags |= TF_EXCLUDE;
 1792                 return (0);
 1793         case TIOCNXCL:
 1794                 tp->t_flags &= ~TF_EXCLUDE;
 1795                 return (0);
 1796         case TIOCSTOP:
 1797                 tp->t_flags |= TF_STOPPED;
 1798                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1799                 return (0);
 1800         case TIOCSTART:
 1801                 tp->t_flags &= ~TF_STOPPED;
 1802                 ttydevsw_outwakeup(tp);
 1803                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1804                 return (0);
 1805         case TIOCSTAT:
 1806                 tty_info(tp);
 1807                 return (0);
 1808         case TIOCSTI:
 1809                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1810                         return (EPERM);
 1811                 if (!tty_is_ctty(tp, td->td_proc) &&
 1812                     priv_check(td, PRIV_TTY_STI))
 1813                         return (EACCES);
 1814                 ttydisc_rint(tp, *(char *)data, 0);
 1815                 ttydisc_rint_done(tp);
 1816                 return (0);
 1817         }
 1818 
 1819 #ifdef COMPAT_43TTY
 1820         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1821 #else /* !COMPAT_43TTY */
 1822         return (ENOIOCTL);
 1823 #endif /* COMPAT_43TTY */
 1824 }
 1825 
 1826 int
 1827 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1828 {
 1829         int error;
 1830 
 1831         tty_lock_assert(tp, MA_OWNED);
 1832 
 1833         if (tty_gone(tp))
 1834                 return (ENXIO);
 1835 
 1836         error = ttydevsw_ioctl(tp, cmd, data, td);
 1837         if (error == ENOIOCTL)
 1838                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1839 
 1840         return (error);
 1841 }
 1842 
 1843 dev_t
 1844 tty_udev(struct tty *tp)
 1845 {
 1846 
 1847         if (tp->t_dev)
 1848                 return (dev2udev(tp->t_dev));
 1849         else
 1850                 return (NODEV);
 1851 }
 1852 
 1853 int
 1854 tty_checkoutq(struct tty *tp)
 1855 {
 1856 
 1857         /* 256 bytes should be enough to print a log message. */
 1858         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1859 }
 1860 
 1861 void
 1862 tty_hiwat_in_block(struct tty *tp)
 1863 {
 1864 
 1865         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1866             tp->t_termios.c_iflag & IXOFF &&
 1867             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1868                 /*
 1869                  * Input flow control. Only enter the high watermark when we
 1870                  * can successfully store the VSTOP character.
 1871                  */
 1872                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1873                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1874                         tp->t_flags |= TF_HIWAT_IN;
 1875         } else {
 1876                 /* No input flow control. */
 1877                 tp->t_flags |= TF_HIWAT_IN;
 1878         }
 1879 }
 1880 
 1881 void
 1882 tty_hiwat_in_unblock(struct tty *tp)
 1883 {
 1884 
 1885         if (tp->t_flags & TF_HIWAT_IN &&
 1886             tp->t_termios.c_iflag & IXOFF &&
 1887             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1888                 /*
 1889                  * Input flow control. Only leave the high watermark when we
 1890                  * can successfully store the VSTART character.
 1891                  */
 1892                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1893                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1894                         tp->t_flags &= ~TF_HIWAT_IN;
 1895         } else {
 1896                 /* No input flow control. */
 1897                 tp->t_flags &= ~TF_HIWAT_IN;
 1898         }
 1899 
 1900         if (!tty_gone(tp))
 1901                 ttydevsw_inwakeup(tp);
 1902 }
 1903 
 1904 /*
 1905  * TTY hooks interface.
 1906  */
 1907 
 1908 static int
 1909 ttyhook_defrint(struct tty *tp, char c, int flags)
 1910 {
 1911 
 1912         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1913                 return (-1);
 1914 
 1915         return (0);
 1916 }
 1917 
 1918 int
 1919 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
 1920     void *softc)
 1921 {
 1922         struct tty *tp;
 1923         struct file *fp;
 1924         struct cdev *dev;
 1925         struct cdevsw *cdp;
 1926         struct filedesc *fdp;
 1927         cap_rights_t rights;
 1928         int error, ref;
 1929 
 1930         /* Validate the file descriptor. */
 1931         fdp = p->p_fd;
 1932         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
 1933             &fp, NULL);
 1934         if (error != 0)
 1935                 return (error);
 1936         if (fp->f_ops == &badfileops) {
 1937                 error = EBADF;
 1938                 goto done1;
 1939         }
 1940 
 1941         /*
 1942          * Make sure the vnode is bound to a character device.
 1943          * Unlocked check for the vnode type is ok there, because we
 1944          * only shall prevent calling devvn_refthread on the file that
 1945          * never has been opened over a character device.
 1946          */
 1947         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1948                 error = EINVAL;
 1949                 goto done1;
 1950         }
 1951 
 1952         /* Make sure it is a TTY. */
 1953         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
 1954         if (cdp == NULL) {
 1955                 error = ENXIO;
 1956                 goto done1;
 1957         }
 1958         if (dev != fp->f_data) {
 1959                 error = ENXIO;
 1960                 goto done2;
 1961         }
 1962         if (cdp != &ttydev_cdevsw) {
 1963                 error = ENOTTY;
 1964                 goto done2;
 1965         }
 1966         tp = dev->si_drv1;
 1967 
 1968         /* Try to attach the hook to the TTY. */
 1969         error = EBUSY;
 1970         tty_lock(tp);
 1971         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1972         if (tp->t_flags & TF_HOOK)
 1973                 goto done3;
 1974 
 1975         tp->t_flags |= TF_HOOK;
 1976         tp->t_hook = th;
 1977         tp->t_hooksoftc = softc;
 1978         *rtp = tp;
 1979         error = 0;
 1980 
 1981         /* Maybe we can switch into bypass mode now. */
 1982         ttydisc_optimize(tp);
 1983 
 1984         /* Silently convert rint() calls to rint_bypass() when possible. */
 1985         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 1986                 th->th_rint = ttyhook_defrint;
 1987 
 1988 done3:  tty_unlock(tp);
 1989 done2:  dev_relthread(dev, ref);
 1990 done1:  fdrop(fp, curthread);
 1991         return (error);
 1992 }
 1993 
 1994 void
 1995 ttyhook_unregister(struct tty *tp)
 1996 {
 1997 
 1998         tty_lock_assert(tp, MA_OWNED);
 1999         MPASS(tp->t_flags & TF_HOOK);
 2000 
 2001         /* Disconnect the hook. */
 2002         tp->t_flags &= ~TF_HOOK;
 2003         tp->t_hook = NULL;
 2004 
 2005         /* Maybe we need to leave bypass mode. */
 2006         ttydisc_optimize(tp);
 2007 
 2008         /* Maybe deallocate the TTY as well. */
 2009         tty_rel_free(tp);
 2010 }
 2011 
 2012 /*
 2013  * /dev/console handling.
 2014  */
 2015 
 2016 static int
 2017 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 2018 {
 2019         struct tty *tp;
 2020 
 2021         /* System has no console device. */
 2022         if (dev_console_filename == NULL)
 2023                 return (ENXIO);
 2024 
 2025         /* Look up corresponding TTY by device name. */
 2026         sx_slock(&tty_list_sx);
 2027         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2028                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 2029                         dev_console->si_drv1 = tp;
 2030                         break;
 2031                 }
 2032         }
 2033         sx_sunlock(&tty_list_sx);
 2034 
 2035         /* System console has no TTY associated. */
 2036         if (dev_console->si_drv1 == NULL)
 2037                 return (ENXIO);
 2038 
 2039         return (ttydev_open(dev, oflags, devtype, td));
 2040 }
 2041 
 2042 static int
 2043 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 2044 {
 2045 
 2046         log_console(uio);
 2047 
 2048         return (ttydev_write(dev, uio, ioflag));
 2049 }
 2050 
 2051 /*
 2052  * /dev/console is a little different than normal TTY's.  When opened,
 2053  * it determines which TTY to use.  When data gets written to it, it
 2054  * will be logged in the kernel message buffer.
 2055  */
 2056 static struct cdevsw ttyconsdev_cdevsw = {
 2057         .d_version      = D_VERSION,
 2058         .d_open         = ttyconsdev_open,
 2059         .d_close        = ttydev_close,
 2060         .d_read         = ttydev_read,
 2061         .d_write        = ttyconsdev_write,
 2062         .d_ioctl        = ttydev_ioctl,
 2063         .d_kqfilter     = ttydev_kqfilter,
 2064         .d_poll         = ttydev_poll,
 2065         .d_mmap         = ttydev_mmap,
 2066         .d_name         = "ttyconsdev",
 2067         .d_flags        = D_TTY,
 2068 };
 2069 
 2070 static void
 2071 ttyconsdev_init(void *unused __unused)
 2072 {
 2073 
 2074         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
 2075             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
 2076 }
 2077 
 2078 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 2079 
 2080 void
 2081 ttyconsdev_select(const char *name)
 2082 {
 2083 
 2084         dev_console_filename = name;
 2085 }
 2086 
 2087 /*
 2088  * Debugging routines.
 2089  */
 2090 
 2091 #include "opt_ddb.h"
 2092 #ifdef DDB
 2093 #include <ddb/ddb.h>
 2094 #include <ddb/db_sym.h>
 2095 
 2096 static const struct {
 2097         int flag;
 2098         char val;
 2099 } ttystates[] = {
 2100 #if 0
 2101         { TF_NOPREFIX,          'N' },
 2102 #endif
 2103         { TF_INITLOCK,          'I' },
 2104         { TF_CALLOUT,           'C' },
 2105 
 2106         /* Keep these together -> 'Oi' and 'Oo'. */
 2107         { TF_OPENED,            'O' },
 2108         { TF_OPENED_IN,         'i' },
 2109         { TF_OPENED_OUT,        'o' },
 2110         { TF_OPENED_CONS,       'c' },
 2111 
 2112         { TF_GONE,              'G' },
 2113         { TF_OPENCLOSE,         'B' },
 2114         { TF_ASYNC,             'Y' },
 2115         { TF_LITERAL,           'L' },
 2116 
 2117         /* Keep these together -> 'Hi' and 'Ho'. */
 2118         { TF_HIWAT,             'H' },
 2119         { TF_HIWAT_IN,          'i' },
 2120         { TF_HIWAT_OUT,         'o' },
 2121 
 2122         { TF_STOPPED,           'S' },
 2123         { TF_EXCLUDE,           'X' },
 2124         { TF_BYPASS,            'l' },
 2125         { TF_ZOMBIE,            'Z' },
 2126         { TF_HOOK,              's' },
 2127 
 2128         /* Keep these together -> 'bi' and 'bo'. */
 2129         { TF_BUSY,              'b' },
 2130         { TF_BUSY_IN,           'i' },
 2131         { TF_BUSY_OUT,          'o' },
 2132 
 2133         { 0,                    '\0'},
 2134 };
 2135 
 2136 #define TTY_FLAG_BITS \
 2137         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
 2138         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
 2139         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
 2140         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
 2141         "\21HOOK\22BUSY_IN\23BUSY_OUT"
 2142 
 2143 #define DB_PRINTSYM(name, addr) \
 2144         db_printf("%s  " #name ": ", sep); \
 2145         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 2146         db_printf("\n");
 2147 
 2148 static void
 2149 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2150 {
 2151 
 2152         db_printf("%sdevsw: ", sep);
 2153         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2154         db_printf(" (%p)\n", tsw);
 2155         DB_PRINTSYM(open, tsw->tsw_open);
 2156         DB_PRINTSYM(close, tsw->tsw_close);
 2157         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2158         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2159         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2160         DB_PRINTSYM(param, tsw->tsw_param);
 2161         DB_PRINTSYM(modem, tsw->tsw_modem);
 2162         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2163         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2164         DB_PRINTSYM(free, tsw->tsw_free);
 2165 }
 2166 
 2167 static void
 2168 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2169 {
 2170 
 2171         db_printf("%shook: ", sep);
 2172         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2173         db_printf(" (%p)\n", th);
 2174         if (th == NULL)
 2175                 return;
 2176         DB_PRINTSYM(rint, th->th_rint);
 2177         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2178         DB_PRINTSYM(rint_done, th->th_rint_done);
 2179         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2180         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2181         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2182         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2183         DB_PRINTSYM(close, th->th_close);
 2184 }
 2185 
 2186 static void
 2187 _db_show_termios(const char *name, const struct termios *t)
 2188 {
 2189 
 2190         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2191             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2192             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2193             t->c_ispeed, t->c_ospeed);
 2194 }
 2195 
 2196 /* DDB command to show TTY statistics. */
 2197 DB_SHOW_COMMAND(tty, db_show_tty)
 2198 {
 2199         struct tty *tp;
 2200 
 2201         if (!have_addr) {
 2202                 db_printf("usage: show tty <addr>\n");
 2203                 return;
 2204         }
 2205         tp = (struct tty *)addr;
 2206 
 2207         db_printf("%p: %s\n", tp, tty_devname(tp));
 2208         db_printf("\tmtx: %p\n", tp->t_mtx);
 2209         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
 2210         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2211 
 2212         /* Buffering mechanisms. */
 2213         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2214             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2215             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2216             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2217         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2218             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2219             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2220         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2221         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2222         _db_show_termios("\ttermios", &tp->t_termios);
 2223         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2224             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2225             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2226         db_printf("\tcolumn: %u\n", tp->t_column);
 2227         db_printf("\twritepos: %u\n", tp->t_writepos);
 2228         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2229 
 2230         /* Init/lock-state devices. */
 2231         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2232         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2233         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2234         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2235 
 2236         /* Hooks */
 2237         _db_show_devsw("\t", tp->t_devsw);
 2238         _db_show_hooks("\t", tp->t_hook);
 2239 
 2240         /* Process info. */
 2241         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2242             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2243             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2244         db_printf("\tsession: %p", tp->t_session);
 2245         if (tp->t_session != NULL)
 2246             db_printf(" count %u leader %p tty %p sid %d login %s",
 2247                 tp->t_session->s_count, tp->t_session->s_leader,
 2248                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2249                 tp->t_session->s_login);
 2250         db_printf("\n");
 2251         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2252         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2253         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2254         db_printf("\tdev: %p\n", tp->t_dev);
 2255 }
 2256 
 2257 /* DDB command to list TTYs. */
 2258 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2259 {
 2260         struct tty *tp;
 2261         size_t isiz, osiz;
 2262         int i, j;
 2263 
 2264         /* Make the output look like `pstat -t'. */
 2265         db_printf("PTR        ");
 2266 #if defined(__LP64__)
 2267         db_printf("        ");
 2268 #endif
 2269         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2270             "COL  SESS  PGID STATE\n");
 2271 
 2272         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2273                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2274                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2275 
 2276                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
 2277                     "%5d ", tp, tty_devname(tp), isiz,
 2278                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2279                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2280                     isiz - tp->t_inlow, osiz,
 2281                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2282                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
 2283                     tp->t_session ? tp->t_session->s_sid : 0,
 2284                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2285 
 2286                 /* Flag bits. */
 2287                 for (i = j = 0; ttystates[i].flag; i++)
 2288                         if (tp->t_flags & ttystates[i].flag) {
 2289                                 db_printf("%c", ttystates[i].val);
 2290                                 j++;
 2291                         }
 2292                 if (j == 0)
 2293                         db_printf("-");
 2294                 db_printf("\n");
 2295         }
 2296 }
 2297 #endif /* DDB */

Cache object: e019c436d880a3b61d12a614637e11fb


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