The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: 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: stable/10/sys/kern/tty.c 361358 2020-05-22 09:01:26Z hselasky $");
   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, revokecnt;
  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                         revokecnt = tp->t_revokecnt;
  145                         error = tty_timedwait(tp, &tp->t_outwait, hz);
  146                         switch (error) {
  147                         case ERESTART:
  148                                 if (revokecnt != tp->t_revokecnt)
  149                                         error = 0;
  150                                 break;
  151                         case EWOULDBLOCK:
  152                                 if (ttyoutq_bytesused(&tp->t_outq) < bytesused)
  153                                         error = 0;
  154                                 break;
  155                         }
  156                 } else
  157                         error = tty_wait(tp, &tp->t_outwait);
  158 
  159                 if (error)
  160                         return (error);
  161         }
  162 
  163         return (0);
  164 }
  165 
  166 /*
  167  * Though ttydev_enter() and ttydev_leave() seem to be related, they
  168  * don't have to be used together. ttydev_enter() is used by the cdev
  169  * operations to prevent an actual operation from being processed when
  170  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
  171  * and ttydev_close() to determine whether per-TTY data should be
  172  * deallocated.
  173  */
  174 
  175 static __inline int
  176 ttydev_enter(struct tty *tp)
  177 {
  178 
  179         tty_lock(tp);
  180 
  181         if (tty_gone(tp) || !tty_opened(tp)) {
  182                 /* Device is already gone. */
  183                 tty_unlock(tp);
  184                 return (ENXIO);
  185         }
  186 
  187         return (0);
  188 }
  189 
  190 static void
  191 ttydev_leave(struct tty *tp)
  192 {
  193 
  194         tty_lock_assert(tp, MA_OWNED);
  195 
  196         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
  197                 /* Device is still opened somewhere. */
  198                 tty_unlock(tp);
  199                 return;
  200         }
  201 
  202         tp->t_flags |= TF_OPENCLOSE;
  203 
  204         /* Stop asynchronous I/O. */
  205         funsetown(&tp->t_sigio);
  206 
  207         /* Remove console TTY. */
  208         if (constty == tp)
  209                 constty_clear();
  210 
  211         /* Drain any output. */
  212         MPASS((tp->t_flags & TF_STOPPED) == 0);
  213         if (!tty_gone(tp))
  214                 tty_drain(tp, 1);
  215 
  216         ttydisc_close(tp);
  217 
  218         /* Free i/o queues now since they might be large. */
  219         ttyinq_free(&tp->t_inq);
  220         tp->t_inlow = 0;
  221         ttyoutq_free(&tp->t_outq);
  222         tp->t_outlow = 0;
  223 
  224         knlist_clear(&tp->t_inpoll.si_note, 1);
  225         knlist_clear(&tp->t_outpoll.si_note, 1);
  226 
  227         if (!tty_gone(tp))
  228                 ttydevsw_close(tp);
  229 
  230         tp->t_flags &= ~TF_OPENCLOSE;
  231         cv_broadcast(&tp->t_dcdwait);
  232         tty_rel_free(tp);
  233 }
  234 
  235 /*
  236  * Operations that are exposed through the character device in /dev.
  237  */
  238 static int
  239 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
  240     struct thread *td)
  241 {
  242         struct tty *tp;
  243         int error;
  244 
  245         tp = dev->si_drv1;
  246         error = 0;
  247         tty_lock(tp);
  248         if (tty_gone(tp)) {
  249                 /* Device is already gone. */
  250                 tty_unlock(tp);
  251                 return (ENXIO);
  252         }
  253 
  254         /*
  255          * Block when other processes are currently opening or closing
  256          * the TTY.
  257          */
  258         while (tp->t_flags & TF_OPENCLOSE) {
  259                 error = tty_wait(tp, &tp->t_dcdwait);
  260                 if (error != 0) {
  261                         tty_unlock(tp);
  262                         return (error);
  263                 }
  264         }
  265         tp->t_flags |= TF_OPENCLOSE;
  266 
  267         /*
  268          * Make sure the "tty" and "cua" device cannot be opened at the
  269          * same time.  The console is a "tty" device.
  270          */
  271         if (TTY_CALLOUT(tp, dev)) {
  272                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
  273                         error = EBUSY;
  274                         goto done;
  275                 }
  276         } else {
  277                 if (tp->t_flags & TF_OPENED_OUT) {
  278                         error = EBUSY;
  279                         goto done;
  280                 }
  281         }
  282 
  283         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
  284                 error = EBUSY;
  285                 goto done;
  286         }
  287 
  288         if (!tty_opened(tp)) {
  289                 /* Set proper termios flags. */
  290                 if (TTY_CALLOUT(tp, dev))
  291                         tp->t_termios = tp->t_termios_init_out;
  292                 else
  293                         tp->t_termios = tp->t_termios_init_in;
  294                 ttydevsw_param(tp, &tp->t_termios);
  295                 /* Prevent modem control on callout devices and /dev/console. */
  296                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
  297                         tp->t_termios.c_cflag |= CLOCAL;
  298 
  299                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
  300 
  301                 error = ttydevsw_open(tp);
  302                 if (error != 0)
  303                         goto done;
  304 
  305                 ttydisc_open(tp);
  306                 tty_watermarks(tp); /* XXXGL: drops lock */
  307         }
  308 
  309         /* Wait for Carrier Detect. */
  310         if ((oflags & O_NONBLOCK) == 0 &&
  311             (tp->t_termios.c_cflag & CLOCAL) == 0) {
  312                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
  313                         error = tty_wait(tp, &tp->t_dcdwait);
  314                         if (error != 0)
  315                                 goto done;
  316                 }
  317         }
  318 
  319         if (dev == dev_console)
  320                 tp->t_flags |= TF_OPENED_CONS;
  321         else if (TTY_CALLOUT(tp, dev))
  322                 tp->t_flags |= TF_OPENED_OUT;
  323         else
  324                 tp->t_flags |= TF_OPENED_IN;
  325         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
  326             (tp->t_flags & TF_OPENED_OUT) == 0);
  327 
  328 done:   tp->t_flags &= ~TF_OPENCLOSE;
  329         cv_broadcast(&tp->t_dcdwait);
  330         ttydev_leave(tp);
  331 
  332         return (error);
  333 }
  334 
  335 static int
  336 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
  337     struct thread *td __unused)
  338 {
  339         struct tty *tp = dev->si_drv1;
  340 
  341         tty_lock(tp);
  342 
  343         /*
  344          * Don't actually close the device if it is being used as the
  345          * console.
  346          */
  347         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
  348             (tp->t_flags & TF_OPENED_OUT) == 0);
  349         if (dev == dev_console)
  350                 tp->t_flags &= ~TF_OPENED_CONS;
  351         else
  352                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
  353 
  354         if (tp->t_flags & TF_OPENED) {
  355                 tty_unlock(tp);
  356                 return (0);
  357         }
  358 
  359         /*
  360          * This can only be called once. The callin and the callout
  361          * devices cannot be opened at the same time.
  362          */
  363         tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
  364 
  365         /* Properly wake up threads that are stuck - revoke(). */
  366         tp->t_revokecnt++;
  367         tty_wakeup(tp, FREAD|FWRITE);
  368         cv_broadcast(&tp->t_bgwait);
  369         cv_broadcast(&tp->t_dcdwait);
  370 
  371         ttydev_leave(tp);
  372 
  373         return (0);
  374 }
  375 
  376 static __inline int
  377 tty_is_ctty(struct tty *tp, struct proc *p)
  378 {
  379 
  380         tty_lock_assert(tp, MA_OWNED);
  381 
  382         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
  383 }
  384 
  385 int
  386 tty_wait_background(struct tty *tp, struct thread *td, int sig)
  387 {
  388         struct proc *p = td->td_proc;
  389         struct pgrp *pg;
  390         ksiginfo_t ksi;
  391         int error;
  392 
  393         MPASS(sig == SIGTTIN || sig == SIGTTOU);
  394         tty_lock_assert(tp, MA_OWNED);
  395 
  396         for (;;) {
  397                 PROC_LOCK(p);
  398                 /*
  399                  * The process should only sleep, when:
  400                  * - This terminal is the controlling terminal
  401                  * - Its process group is not the foreground process
  402                  *   group
  403                  * - The parent process isn't waiting for the child to
  404                  *   exit
  405                  * - the signal to send to the process isn't masked
  406                  */
  407                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
  408                         /* Allow the action to happen. */
  409                         PROC_UNLOCK(p);
  410                         return (0);
  411                 }
  412 
  413                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
  414                     SIGISMEMBER(td->td_sigmask, sig)) {
  415                         /* Only allow them in write()/ioctl(). */
  416                         PROC_UNLOCK(p);
  417                         return (sig == SIGTTOU ? 0 : EIO);
  418                 }
  419 
  420                 pg = p->p_pgrp;
  421                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
  422                         /* Don't allow the action to happen. */
  423                         PROC_UNLOCK(p);
  424                         return (EIO);
  425                 }
  426                 PROC_UNLOCK(p);
  427 
  428                 /*
  429                  * Send the signal and sleep until we're the new
  430                  * foreground process group.
  431                  */
  432                 if (sig != 0) {
  433                         ksiginfo_init(&ksi);
  434                         ksi.ksi_code = SI_KERNEL;
  435                         ksi.ksi_signo = sig;
  436                         sig = 0;
  437                 }
  438                 PGRP_LOCK(pg);
  439                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
  440                 PGRP_UNLOCK(pg);
  441 
  442                 error = tty_wait(tp, &tp->t_bgwait);
  443                 if (error)
  444                         return (error);
  445         }
  446 }
  447 
  448 static int
  449 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
  450 {
  451         struct tty *tp = dev->si_drv1;
  452         int error;
  453 
  454         error = ttydev_enter(tp);
  455         if (error)
  456                 goto done;
  457         error = ttydisc_read(tp, uio, ioflag);
  458         tty_unlock(tp);
  459 
  460         /*
  461          * The read() call should not throw an error when the device is
  462          * being destroyed. Silently convert it to an EOF.
  463          */
  464 done:   if (error == ENXIO)
  465                 error = 0;
  466         return (error);
  467 }
  468 
  469 static int
  470 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  471 {
  472         struct tty *tp = dev->si_drv1;
  473         int error;
  474 
  475         error = ttydev_enter(tp);
  476         if (error)
  477                 return (error);
  478 
  479         if (tp->t_termios.c_lflag & TOSTOP) {
  480                 error = tty_wait_background(tp, curthread, SIGTTOU);
  481                 if (error)
  482                         goto done;
  483         }
  484 
  485         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  486                 /* Allow non-blocking writes to bypass serialization. */
  487                 error = ttydisc_write(tp, uio, ioflag);
  488         } else {
  489                 /* Serialize write() calls. */
  490                 while (tp->t_flags & TF_BUSY_OUT) {
  491                         error = tty_wait(tp, &tp->t_outserwait);
  492                         if (error)
  493                                 goto done;
  494                 }
  495 
  496                 tp->t_flags |= TF_BUSY_OUT;
  497                 error = ttydisc_write(tp, uio, ioflag);
  498                 tp->t_flags &= ~TF_BUSY_OUT;
  499                 cv_signal(&tp->t_outserwait);
  500         }
  501 
  502 done:   tty_unlock(tp);
  503         return (error);
  504 }
  505 
  506 static int
  507 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  508     struct thread *td)
  509 {
  510         struct tty *tp = dev->si_drv1;
  511         int error;
  512 
  513         error = ttydev_enter(tp);
  514         if (error)
  515                 return (error);
  516 
  517         switch (cmd) {
  518         case TIOCCBRK:
  519         case TIOCCONS:
  520         case TIOCDRAIN:
  521         case TIOCEXCL:
  522         case TIOCFLUSH:
  523         case TIOCNXCL:
  524         case TIOCSBRK:
  525         case TIOCSCTTY:
  526         case TIOCSETA:
  527         case TIOCSETAF:
  528         case TIOCSETAW:
  529         case TIOCSPGRP:
  530         case TIOCSTART:
  531         case TIOCSTAT:
  532         case TIOCSTI:
  533         case TIOCSTOP:
  534         case TIOCSWINSZ:
  535 #if 0
  536         case TIOCSDRAINWAIT:
  537         case TIOCSETD:
  538 #endif
  539 #ifdef COMPAT_43TTY
  540         case  TIOCLBIC:
  541         case  TIOCLBIS:
  542         case  TIOCLSET:
  543         case  TIOCSETC:
  544         case OTIOCSETD:
  545         case  TIOCSETN:
  546         case  TIOCSETP:
  547         case  TIOCSLTC:
  548 #endif /* COMPAT_43TTY */
  549                 /*
  550                  * If the ioctl() causes the TTY to be modified, let it
  551                  * wait in the background.
  552                  */
  553                 error = tty_wait_background(tp, curthread, SIGTTOU);
  554                 if (error)
  555                         goto done;
  556         }
  557 
  558         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  559                 struct termios *old = &tp->t_termios;
  560                 struct termios *new = (struct termios *)data;
  561                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  562                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  563                 int cc;
  564 
  565                 /*
  566                  * Lock state devices.  Just overwrite the values of the
  567                  * commands that are currently in use.
  568                  */
  569                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  570                     (new->c_iflag & ~lock->c_iflag);
  571                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  572                     (new->c_oflag & ~lock->c_oflag);
  573                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  574                     (new->c_cflag & ~lock->c_cflag);
  575                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  576                     (new->c_lflag & ~lock->c_lflag);
  577                 for (cc = 0; cc < NCCS; ++cc)
  578                         if (lock->c_cc[cc])
  579                                 new->c_cc[cc] = old->c_cc[cc];
  580                 if (lock->c_ispeed)
  581                         new->c_ispeed = old->c_ispeed;
  582                 if (lock->c_ospeed)
  583                         new->c_ospeed = old->c_ospeed;
  584         }
  585 
  586         error = tty_ioctl(tp, cmd, data, fflag, td);
  587 done:   tty_unlock(tp);
  588 
  589         return (error);
  590 }
  591 
  592 static int
  593 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  594 {
  595         struct tty *tp = dev->si_drv1;
  596         int error, revents = 0;
  597 
  598         error = ttydev_enter(tp);
  599         if (error)
  600                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  601 
  602         if (events & (POLLIN|POLLRDNORM)) {
  603                 /* See if we can read something. */
  604                 if (ttydisc_read_poll(tp) > 0)
  605                         revents |= events & (POLLIN|POLLRDNORM);
  606         }
  607 
  608         if (tp->t_flags & TF_ZOMBIE) {
  609                 /* Hangup flag on zombie state. */
  610                 revents |= POLLHUP;
  611         } else if (events & (POLLOUT|POLLWRNORM)) {
  612                 /* See if we can write something. */
  613                 if (ttydisc_write_poll(tp) > 0)
  614                         revents |= events & (POLLOUT|POLLWRNORM);
  615         }
  616 
  617         if (revents == 0) {
  618                 if (events & (POLLIN|POLLRDNORM))
  619                         selrecord(td, &tp->t_inpoll);
  620                 if (events & (POLLOUT|POLLWRNORM))
  621                         selrecord(td, &tp->t_outpoll);
  622         }
  623 
  624         tty_unlock(tp);
  625 
  626         return (revents);
  627 }
  628 
  629 static int
  630 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  631     int nprot, vm_memattr_t *memattr)
  632 {
  633         struct tty *tp = dev->si_drv1;
  634         int error;
  635 
  636         /* Handle mmap() through the driver. */
  637 
  638         error = ttydev_enter(tp);
  639         if (error)
  640                 return (-1);
  641         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
  642         tty_unlock(tp);
  643 
  644         return (error);
  645 }
  646 
  647 /*
  648  * kqueue support.
  649  */
  650 
  651 static void
  652 tty_kqops_read_detach(struct knote *kn)
  653 {
  654         struct tty *tp = kn->kn_hook;
  655 
  656         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  657 }
  658 
  659 static int
  660 tty_kqops_read_event(struct knote *kn, long hint __unused)
  661 {
  662         struct tty *tp = kn->kn_hook;
  663 
  664         tty_lock_assert(tp, MA_OWNED);
  665 
  666         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  667                 kn->kn_flags |= EV_EOF;
  668                 return (1);
  669         } else {
  670                 kn->kn_data = ttydisc_read_poll(tp);
  671                 return (kn->kn_data > 0);
  672         }
  673 }
  674 
  675 static void
  676 tty_kqops_write_detach(struct knote *kn)
  677 {
  678         struct tty *tp = kn->kn_hook;
  679 
  680         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  681 }
  682 
  683 static int
  684 tty_kqops_write_event(struct knote *kn, long hint __unused)
  685 {
  686         struct tty *tp = kn->kn_hook;
  687 
  688         tty_lock_assert(tp, MA_OWNED);
  689 
  690         if (tty_gone(tp)) {
  691                 kn->kn_flags |= EV_EOF;
  692                 return (1);
  693         } else {
  694                 kn->kn_data = ttydisc_write_poll(tp);
  695                 return (kn->kn_data > 0);
  696         }
  697 }
  698 
  699 static struct filterops tty_kqops_read = {
  700         .f_isfd = 1,
  701         .f_detach = tty_kqops_read_detach,
  702         .f_event = tty_kqops_read_event,
  703 };
  704 
  705 static struct filterops tty_kqops_write = {
  706         .f_isfd = 1,
  707         .f_detach = tty_kqops_write_detach,
  708         .f_event = tty_kqops_write_event,
  709 };
  710 
  711 static int
  712 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  713 {
  714         struct tty *tp = dev->si_drv1;
  715         int error;
  716 
  717         error = ttydev_enter(tp);
  718         if (error)
  719                 return (error);
  720 
  721         switch (kn->kn_filter) {
  722         case EVFILT_READ:
  723                 kn->kn_hook = tp;
  724                 kn->kn_fop = &tty_kqops_read;
  725                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  726                 break;
  727         case EVFILT_WRITE:
  728                 kn->kn_hook = tp;
  729                 kn->kn_fop = &tty_kqops_write;
  730                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  731                 break;
  732         default:
  733                 error = EINVAL;
  734                 break;
  735         }
  736 
  737         tty_unlock(tp);
  738         return (error);
  739 }
  740 
  741 static struct cdevsw ttydev_cdevsw = {
  742         .d_version      = D_VERSION,
  743         .d_open         = ttydev_open,
  744         .d_close        = ttydev_close,
  745         .d_read         = ttydev_read,
  746         .d_write        = ttydev_write,
  747         .d_ioctl        = ttydev_ioctl,
  748         .d_kqfilter     = ttydev_kqfilter,
  749         .d_poll         = ttydev_poll,
  750         .d_mmap         = ttydev_mmap,
  751         .d_name         = "ttydev",
  752         .d_flags        = D_TTY,
  753 };
  754 
  755 /*
  756  * Init/lock-state devices
  757  */
  758 
  759 static int
  760 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
  761     struct thread *td)
  762 {
  763         struct tty *tp;
  764         int error;
  765 
  766         tp = dev->si_drv1;
  767         error = 0;
  768         tty_lock(tp);
  769         if (tty_gone(tp))
  770                 error = ENODEV;
  771         tty_unlock(tp);
  772 
  773         return (error);
  774 }
  775 
  776 static int
  777 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
  778     struct thread *td __unused)
  779 {
  780 
  781         return (0);
  782 }
  783 
  784 static int
  785 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
  786     int ioflag __unused)
  787 {
  788 
  789         return (ENODEV);
  790 }
  791 
  792 static int
  793 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  794     struct thread *td)
  795 {
  796         struct tty *tp = dev->si_drv1;
  797         int error;
  798 
  799         tty_lock(tp);
  800         if (tty_gone(tp)) {
  801                 error = ENODEV;
  802                 goto done;
  803         }
  804 
  805         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
  806         if (error != ENOIOCTL)
  807                 goto done;
  808         error = 0;
  809 
  810         switch (cmd) {
  811         case TIOCGETA:
  812                 /* Obtain terminal flags through tcgetattr(). */
  813                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  814                 break;
  815         case TIOCSETA:
  816                 /* Set terminal flags through tcsetattr(). */
  817                 error = priv_check(td, PRIV_TTY_SETA);
  818                 if (error)
  819                         break;
  820                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  821                 break;
  822         case TIOCGETD:
  823                 *(int *)data = TTYDISC;
  824                 break;
  825         case TIOCGWINSZ:
  826                 bzero(data, sizeof(struct winsize));
  827                 break;
  828         default:
  829                 error = ENOTTY;
  830         }
  831 
  832 done:   tty_unlock(tp);
  833         return (error);
  834 }
  835 
  836 static struct cdevsw ttyil_cdevsw = {
  837         .d_version      = D_VERSION,
  838         .d_open         = ttyil_open,
  839         .d_close        = ttyil_close,
  840         .d_read         = ttyil_rdwr,
  841         .d_write        = ttyil_rdwr,
  842         .d_ioctl        = ttyil_ioctl,
  843         .d_name         = "ttyil",
  844         .d_flags        = D_TTY,
  845 };
  846 
  847 static void
  848 tty_init_termios(struct tty *tp)
  849 {
  850         struct termios *t = &tp->t_termios_init_in;
  851 
  852         t->c_cflag = TTYDEF_CFLAG;
  853         t->c_iflag = TTYDEF_IFLAG;
  854         t->c_lflag = TTYDEF_LFLAG;
  855         t->c_oflag = TTYDEF_OFLAG;
  856         t->c_ispeed = TTYDEF_SPEED;
  857         t->c_ospeed = TTYDEF_SPEED;
  858         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  859 
  860         tp->t_termios_init_out = *t;
  861 }
  862 
  863 void
  864 tty_init_console(struct tty *tp, speed_t s)
  865 {
  866         struct termios *ti = &tp->t_termios_init_in;
  867         struct termios *to = &tp->t_termios_init_out;
  868 
  869         if (s != 0) {
  870                 ti->c_ispeed = ti->c_ospeed = s;
  871                 to->c_ispeed = to->c_ospeed = s;
  872         }
  873 
  874         ti->c_cflag |= CLOCAL;
  875         to->c_cflag |= CLOCAL;
  876 }
  877 
  878 /*
  879  * Standard device routine implementations, mostly meant for
  880  * pseudo-terminal device drivers. When a driver creates a new terminal
  881  * device class, missing routines are patched.
  882  */
  883 
  884 static int
  885 ttydevsw_defopen(struct tty *tp __unused)
  886 {
  887 
  888         return (0);
  889 }
  890 
  891 static void
  892 ttydevsw_defclose(struct tty *tp __unused)
  893 {
  894 
  895 }
  896 
  897 static void
  898 ttydevsw_defoutwakeup(struct tty *tp __unused)
  899 {
  900 
  901         panic("Terminal device has output, while not implemented");
  902 }
  903 
  904 static void
  905 ttydevsw_definwakeup(struct tty *tp __unused)
  906 {
  907 
  908 }
  909 
  910 static int
  911 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
  912     caddr_t data __unused, struct thread *td __unused)
  913 {
  914 
  915         return (ENOIOCTL);
  916 }
  917 
  918 static int
  919 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
  920     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
  921 {
  922 
  923         return (ENOIOCTL);
  924 }
  925 
  926 static int
  927 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
  928 {
  929 
  930         /*
  931          * Allow the baud rate to be adjusted for pseudo-devices, but at
  932          * least restrict it to 115200 to prevent excessive buffer
  933          * usage.  Also disallow 0, to prevent foot shooting.
  934          */
  935         if (t->c_ispeed < B50)
  936                 t->c_ispeed = B50;
  937         else if (t->c_ispeed > B115200)
  938                 t->c_ispeed = B115200;
  939         if (t->c_ospeed < B50)
  940                 t->c_ospeed = B50;
  941         else if (t->c_ospeed > B115200)
  942                 t->c_ospeed = B115200;
  943         t->c_cflag |= CREAD;
  944 
  945         return (0);
  946 }
  947 
  948 static int
  949 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
  950     int sigoff __unused)
  951 {
  952 
  953         /* Simulate a carrier to make the TTY layer happy. */
  954         return (SER_DCD);
  955 }
  956 
  957 static int
  958 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
  959     vm_paddr_t *paddr __unused, int nprot __unused,
  960     vm_memattr_t *memattr __unused)
  961 {
  962 
  963         return (-1);
  964 }
  965 
  966 static void
  967 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
  968 {
  969 
  970 }
  971 
  972 static void
  973 ttydevsw_deffree(void *softc __unused)
  974 {
  975 
  976         panic("Terminal device freed without a free-handler");
  977 }
  978 
  979 static bool
  980 ttydevsw_defbusy(struct tty *tp __unused)
  981 {
  982 
  983         return (FALSE);
  984 }
  985 
  986 /*
  987  * TTY allocation and deallocation. TTY devices can be deallocated when
  988  * the driver doesn't use it anymore, when the TTY isn't a session's
  989  * controlling TTY and when the device node isn't opened through devfs.
  990  */
  991 
  992 struct tty *
  993 tty_alloc(struct ttydevsw *tsw, void *sc)
  994 {
  995 
  996         return (tty_alloc_mutex(tsw, sc, NULL));
  997 }
  998 
  999 struct tty *
 1000 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
 1001 {
 1002         struct tty *tp;
 1003 
 1004         /* Make sure the driver defines all routines. */
 1005 #define PATCH_FUNC(x) do {                              \
 1006         if (tsw->tsw_ ## x == NULL)                     \
 1007                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
 1008 } while (0)
 1009         PATCH_FUNC(open);
 1010         PATCH_FUNC(close);
 1011         PATCH_FUNC(outwakeup);
 1012         PATCH_FUNC(inwakeup);
 1013         PATCH_FUNC(ioctl);
 1014         PATCH_FUNC(cioctl);
 1015         PATCH_FUNC(param);
 1016         PATCH_FUNC(modem);
 1017         PATCH_FUNC(mmap);
 1018         PATCH_FUNC(pktnotify);
 1019         PATCH_FUNC(free);
 1020         PATCH_FUNC(busy);
 1021 #undef PATCH_FUNC
 1022 
 1023         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
 1024         tp->t_devsw = tsw;
 1025         tp->t_devswsoftc = sc;
 1026         tp->t_flags = tsw->tsw_flags;
 1027 
 1028         tty_init_termios(tp);
 1029 
 1030         cv_init(&tp->t_inwait, "ttyin");
 1031         cv_init(&tp->t_outwait, "ttyout");
 1032         cv_init(&tp->t_outserwait, "ttyosr");
 1033         cv_init(&tp->t_bgwait, "ttybg");
 1034         cv_init(&tp->t_dcdwait, "ttydcd");
 1035 
 1036         /* Allow drivers to use a custom mutex to lock the TTY. */
 1037         if (mutex != NULL) {
 1038                 tp->t_mtx = mutex;
 1039         } else {
 1040                 tp->t_mtx = &tp->t_mtxobj;
 1041                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
 1042         }
 1043 
 1044         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 1045         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 1046 
 1047         return (tp);
 1048 }
 1049 
 1050 static void
 1051 tty_dealloc(void *arg)
 1052 {
 1053         struct tty *tp = arg;
 1054 
 1055         /*
 1056          * ttyydev_leave() usually frees the i/o queues earlier, but it is
 1057          * not always called between queue allocation and here.  The queues
 1058          * may be allocated by ioctls on a pty control device without the
 1059          * corresponding pty slave device ever being open, or after it is
 1060          * closed.
 1061          */
 1062         ttyinq_free(&tp->t_inq);
 1063         ttyoutq_free(&tp->t_outq);
 1064         seldrain(&tp->t_inpoll);
 1065         seldrain(&tp->t_outpoll);
 1066         knlist_destroy(&tp->t_inpoll.si_note);
 1067         knlist_destroy(&tp->t_outpoll.si_note);
 1068 
 1069         cv_destroy(&tp->t_inwait);
 1070         cv_destroy(&tp->t_outwait);
 1071         cv_destroy(&tp->t_bgwait);
 1072         cv_destroy(&tp->t_dcdwait);
 1073         cv_destroy(&tp->t_outserwait);
 1074 
 1075         if (tp->t_mtx == &tp->t_mtxobj)
 1076                 mtx_destroy(&tp->t_mtxobj);
 1077         ttydevsw_free(tp);
 1078         free(tp, M_TTY);
 1079 }
 1080 
 1081 static void
 1082 tty_rel_free(struct tty *tp)
 1083 {
 1084         struct cdev *dev;
 1085 
 1086         tty_lock_assert(tp, MA_OWNED);
 1087 
 1088 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1089         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1090                 /* TTY is still in use. */
 1091                 tty_unlock(tp);
 1092                 return;
 1093         }
 1094 
 1095         /* TTY can be deallocated. */
 1096         dev = tp->t_dev;
 1097         tp->t_dev = NULL;
 1098         tty_unlock(tp);
 1099 
 1100         if (dev != NULL) {
 1101                 sx_xlock(&tty_list_sx);
 1102                 TAILQ_REMOVE(&tty_list, tp, t_list);
 1103                 tty_list_count--;
 1104                 sx_xunlock(&tty_list_sx);
 1105                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1106         }
 1107 }
 1108 
 1109 void
 1110 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1111 {
 1112 
 1113         MPASS(tp->t_sessioncnt > 0);
 1114         tty_lock_assert(tp, MA_OWNED);
 1115 
 1116         if (tp->t_pgrp == pg)
 1117                 tp->t_pgrp = NULL;
 1118 
 1119         tty_unlock(tp);
 1120 }
 1121 
 1122 void
 1123 tty_rel_sess(struct tty *tp, struct session *sess)
 1124 {
 1125 
 1126         MPASS(tp->t_sessioncnt > 0);
 1127 
 1128         /* Current session has left. */
 1129         if (tp->t_session == sess) {
 1130                 tp->t_session = NULL;
 1131                 MPASS(tp->t_pgrp == NULL);
 1132         }
 1133         tp->t_sessioncnt--;
 1134         tty_rel_free(tp);
 1135 }
 1136 
 1137 void
 1138 tty_rel_gone(struct tty *tp)
 1139 {
 1140 
 1141         MPASS(!tty_gone(tp));
 1142 
 1143         /* Simulate carrier removal. */
 1144         ttydisc_modem(tp, 0);
 1145 
 1146         /* Wake up all blocked threads. */
 1147         tty_wakeup(tp, FREAD|FWRITE);
 1148         cv_broadcast(&tp->t_bgwait);
 1149         cv_broadcast(&tp->t_dcdwait);
 1150 
 1151         tp->t_flags |= TF_GONE;
 1152         tty_rel_free(tp);
 1153 }
 1154 
 1155 /*
 1156  * Exposing information about current TTY's through sysctl
 1157  */
 1158 
 1159 static void
 1160 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1161 {
 1162 
 1163         tty_lock_assert(tp, MA_OWNED);
 1164 
 1165         xt->xt_size = sizeof(struct xtty);
 1166         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1167         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1168         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1169         xt->xt_inlow = tp->t_inlow;
 1170         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1171         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1172         xt->xt_outlow = tp->t_outlow;
 1173         xt->xt_column = tp->t_column;
 1174         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1175         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1176         xt->xt_flags = tp->t_flags;
 1177         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1178 }
 1179 
 1180 static int
 1181 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1182 {
 1183         unsigned long lsize;
 1184         struct xtty *xtlist, *xt;
 1185         struct tty *tp;
 1186         int error;
 1187 
 1188         sx_slock(&tty_list_sx);
 1189         lsize = tty_list_count * sizeof(struct xtty);
 1190         if (lsize == 0) {
 1191                 sx_sunlock(&tty_list_sx);
 1192                 return (0);
 1193         }
 1194 
 1195         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1196 
 1197         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1198                 tty_lock(tp);
 1199                 tty_to_xtty(tp, xt);
 1200                 tty_unlock(tp);
 1201                 xt++;
 1202         }
 1203         sx_sunlock(&tty_list_sx);
 1204 
 1205         error = SYSCTL_OUT(req, xtlist, lsize);
 1206         free(xtlist, M_TTY);
 1207         return (error);
 1208 }
 1209 
 1210 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1211         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1212 
 1213 /*
 1214  * Device node creation. Device has been set up, now we can expose it to
 1215  * the user.
 1216  */
 1217 
 1218 static int
 1219 tty_vmakedevf(struct tty *tp, struct ucred *cred, int flags,
 1220     const char *fmt, va_list ap)
 1221 {
 1222         struct make_dev_args args;
 1223         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
 1224         const char *prefix = "tty";
 1225         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1226         uid_t uid;
 1227         gid_t gid;
 1228         mode_t mode;
 1229         int error;
 1230 
 1231         /* Remove "tty" prefix from devices like PTY's. */
 1232         if (tp->t_flags & TF_NOPREFIX)
 1233                 prefix = "";
 1234 
 1235         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1236 
 1237         if (cred == NULL) {
 1238                 /* System device. */
 1239                 uid = UID_ROOT;
 1240                 gid = GID_WHEEL;
 1241                 mode = S_IRUSR|S_IWUSR;
 1242         } else {
 1243                 /* User device. */
 1244                 uid = cred->cr_ruid;
 1245                 gid = GID_TTY;
 1246                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1247         }
 1248 
 1249         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
 1250         flags |= MAKEDEV_CHECKNAME;
 1251 
 1252         /* Master call-in device. */
 1253         make_dev_args_init(&args);
 1254         args.mda_flags = flags;
 1255         args.mda_devsw = &ttydev_cdevsw;
 1256         args.mda_cr = cred;
 1257         args.mda_uid = uid;
 1258         args.mda_gid = gid;
 1259         args.mda_mode = mode;
 1260         args.mda_si_drv1 = tp;
 1261         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
 1262         if (error != 0)
 1263                 return (error);
 1264         tp->t_dev = dev;
 1265 
 1266         init = lock = cua = cinit = clock = NULL;
 1267 
 1268         /* Slave call-in devices. */
 1269         if (tp->t_flags & TF_INITLOCK) {
 1270                 args.mda_devsw = &ttyil_cdevsw;
 1271                 args.mda_unit = TTYUNIT_INIT;
 1272                 args.mda_si_drv1 = tp;
 1273                 args.mda_si_drv2 = &tp->t_termios_init_in;
 1274                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
 1275                 if (error != 0)
 1276                         goto fail;
 1277                 dev_depends(dev, init);
 1278 
 1279                 args.mda_unit = TTYUNIT_LOCK;
 1280                 args.mda_si_drv2 = &tp->t_termios_lock_in;
 1281                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
 1282                 if (error != 0)
 1283                         goto fail;
 1284                 dev_depends(dev, lock);
 1285         }
 1286 
 1287         /* Call-out devices. */
 1288         if (tp->t_flags & TF_CALLOUT) {
 1289                 make_dev_args_init(&args);
 1290                 args.mda_flags = flags;
 1291                 args.mda_devsw = &ttydev_cdevsw;
 1292                 args.mda_cr = cred;
 1293                 args.mda_uid = UID_UUCP;
 1294                 args.mda_gid = GID_DIALER;
 1295                 args.mda_mode = 0660;
 1296                 args.mda_unit = TTYUNIT_CALLOUT;
 1297                 args.mda_si_drv1 = tp;
 1298                 error = make_dev_s(&args, &cua, "cua%s", name);
 1299                 if (error != 0)
 1300                         goto fail;
 1301                 dev_depends(dev, cua);
 1302 
 1303                 /* Slave call-out devices. */
 1304                 if (tp->t_flags & TF_INITLOCK) {
 1305                         args.mda_devsw = &ttyil_cdevsw;
 1306                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
 1307                         args.mda_si_drv2 = &tp->t_termios_init_out;
 1308                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
 1309                         if (error != 0)
 1310                                 goto fail;
 1311                         dev_depends(dev, cinit);
 1312 
 1313                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
 1314                         args.mda_si_drv2 = &tp->t_termios_lock_out;
 1315                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
 1316                         if (error != 0)
 1317                                 goto fail;
 1318                         dev_depends(dev, clock);
 1319                 }
 1320         }
 1321 
 1322         sx_xlock(&tty_list_sx);
 1323         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
 1324         tty_list_count++;
 1325         sx_xunlock(&tty_list_sx);
 1326 
 1327         return (0);
 1328 
 1329 fail:
 1330         destroy_dev(dev);
 1331         if (init)
 1332                 destroy_dev(init);
 1333         if (lock)
 1334                 destroy_dev(lock);
 1335         if (cinit)
 1336                 destroy_dev(cinit);
 1337         if (clock)
 1338                 destroy_dev(clock);
 1339 
 1340         return (error);
 1341 }
 1342 
 1343 int
 1344 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
 1345     const char *fmt, ...)
 1346 {
 1347         va_list ap;
 1348         int error;
 1349 
 1350         va_start(ap, fmt);
 1351         error = tty_vmakedevf(tp, cred, flags, fmt, ap);
 1352         va_end(ap);
 1353 
 1354         return (error);
 1355 }
 1356 
 1357 void
 1358 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
 1359 {
 1360         va_list ap;
 1361 
 1362         va_start(ap, fmt);
 1363         (void) tty_vmakedevf(tp, cred, 0, fmt, ap);
 1364         va_end(ap);
 1365 }
 1366 
 1367 /*
 1368  * Signalling processes.
 1369  */
 1370 
 1371 void
 1372 tty_signal_sessleader(struct tty *tp, int sig)
 1373 {
 1374         struct proc *p;
 1375 
 1376         tty_lock_assert(tp, MA_OWNED);
 1377         MPASS(sig >= 1 && sig < NSIG);
 1378 
 1379         /* Make signals start output again. */
 1380         tp->t_flags &= ~TF_STOPPED;
 1381 
 1382         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1383                 p = tp->t_session->s_leader;
 1384                 PROC_LOCK(p);
 1385                 kern_psignal(p, sig);
 1386                 PROC_UNLOCK(p);
 1387         }
 1388 }
 1389 
 1390 void
 1391 tty_signal_pgrp(struct tty *tp, int sig)
 1392 {
 1393         ksiginfo_t ksi;
 1394 
 1395         tty_lock_assert(tp, MA_OWNED);
 1396         MPASS(sig >= 1 && sig < NSIG);
 1397 
 1398         /* Make signals start output again. */
 1399         tp->t_flags &= ~TF_STOPPED;
 1400 
 1401         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1402                 tty_info(tp);
 1403         if (tp->t_pgrp != NULL) {
 1404                 ksiginfo_init(&ksi);
 1405                 ksi.ksi_signo = sig;
 1406                 ksi.ksi_code = SI_KERNEL;
 1407                 PGRP_LOCK(tp->t_pgrp);
 1408                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1409                 PGRP_UNLOCK(tp->t_pgrp);
 1410         }
 1411 }
 1412 
 1413 void
 1414 tty_wakeup(struct tty *tp, int flags)
 1415 {
 1416 
 1417         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1418                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1419 
 1420         if (flags & FWRITE) {
 1421                 cv_broadcast(&tp->t_outwait);
 1422                 selwakeup(&tp->t_outpoll);
 1423                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1424         }
 1425         if (flags & FREAD) {
 1426                 cv_broadcast(&tp->t_inwait);
 1427                 selwakeup(&tp->t_inpoll);
 1428                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1429         }
 1430 }
 1431 
 1432 int
 1433 tty_wait(struct tty *tp, struct cv *cv)
 1434 {
 1435         int error;
 1436         int revokecnt = tp->t_revokecnt;
 1437 
 1438         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1439         MPASS(!tty_gone(tp));
 1440 
 1441         error = cv_wait_sig(cv, tp->t_mtx);
 1442 
 1443         /* Bail out when the device slipped away. */
 1444         if (tty_gone(tp))
 1445                 return (ENXIO);
 1446 
 1447         /* Restart the system call when we may have been revoked. */
 1448         if (tp->t_revokecnt != revokecnt)
 1449                 return (ERESTART);
 1450 
 1451         return (error);
 1452 }
 1453 
 1454 int
 1455 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1456 {
 1457         int error;
 1458         int revokecnt = tp->t_revokecnt;
 1459 
 1460         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1461         MPASS(!tty_gone(tp));
 1462 
 1463         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1464 
 1465         /* Bail out when the device slipped away. */
 1466         if (tty_gone(tp))
 1467                 return (ENXIO);
 1468 
 1469         /* Restart the system call when we may have been revoked. */
 1470         if (tp->t_revokecnt != revokecnt)
 1471                 return (ERESTART);
 1472 
 1473         return (error);
 1474 }
 1475 
 1476 void
 1477 tty_flush(struct tty *tp, int flags)
 1478 {
 1479 
 1480         if (flags & FWRITE) {
 1481                 tp->t_flags &= ~TF_HIWAT_OUT;
 1482                 ttyoutq_flush(&tp->t_outq);
 1483                 tty_wakeup(tp, FWRITE);
 1484                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1485         }
 1486         if (flags & FREAD) {
 1487                 tty_hiwat_in_unblock(tp);
 1488                 ttyinq_flush(&tp->t_inq);
 1489                 ttydevsw_inwakeup(tp);
 1490                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1491         }
 1492 }
 1493 
 1494 void
 1495 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
 1496 {
 1497 
 1498         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
 1499                 return;
 1500         tp->t_winsize = *wsz;
 1501         tty_signal_pgrp(tp, SIGWINCH);
 1502 }
 1503 
 1504 static int
 1505 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1506     struct thread *td)
 1507 {
 1508         int error;
 1509 
 1510         switch (cmd) {
 1511         /*
 1512          * Modem commands.
 1513          * The SER_* and TIOCM_* flags are the same, but one bit
 1514          * shifted. I don't know why.
 1515          */
 1516         case TIOCSDTR:
 1517                 ttydevsw_modem(tp, SER_DTR, 0);
 1518                 return (0);
 1519         case TIOCCDTR:
 1520                 ttydevsw_modem(tp, 0, SER_DTR);
 1521                 return (0);
 1522         case TIOCMSET: {
 1523                 int bits = *(int *)data;
 1524                 ttydevsw_modem(tp,
 1525                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1526                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1527                 return (0);
 1528         }
 1529         case TIOCMBIS: {
 1530                 int bits = *(int *)data;
 1531                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1532                 return (0);
 1533         }
 1534         case TIOCMBIC: {
 1535                 int bits = *(int *)data;
 1536                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1537                 return (0);
 1538         }
 1539         case TIOCMGET:
 1540                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1541                 return (0);
 1542 
 1543         case FIOASYNC:
 1544                 if (*(int *)data)
 1545                         tp->t_flags |= TF_ASYNC;
 1546                 else
 1547                         tp->t_flags &= ~TF_ASYNC;
 1548                 return (0);
 1549         case FIONBIO:
 1550                 /* This device supports non-blocking operation. */
 1551                 return (0);
 1552         case FIONREAD:
 1553                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1554                 return (0);
 1555         case FIONWRITE:
 1556         case TIOCOUTQ:
 1557                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1558                 return (0);
 1559         case FIOSETOWN:
 1560                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1561                         /* Not allowed to set ownership. */
 1562                         return (ENOTTY);
 1563 
 1564                 /* Temporarily unlock the TTY to set ownership. */
 1565                 tty_unlock(tp);
 1566                 error = fsetown(*(int *)data, &tp->t_sigio);
 1567                 tty_lock(tp);
 1568                 return (error);
 1569         case FIOGETOWN:
 1570                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1571                         /* Not allowed to set ownership. */
 1572                         return (ENOTTY);
 1573 
 1574                 /* Get ownership. */
 1575                 *(int *)data = fgetown(&tp->t_sigio);
 1576                 return (0);
 1577         case TIOCGETA:
 1578                 /* Obtain terminal flags through tcgetattr(). */
 1579                 *(struct termios*)data = tp->t_termios;
 1580                 return (0);
 1581         case TIOCSETA:
 1582         case TIOCSETAW:
 1583         case TIOCSETAF: {
 1584                 struct termios *t = data;
 1585 
 1586                 /*
 1587                  * Who makes up these funny rules? According to POSIX,
 1588                  * input baud rate is set equal to the output baud rate
 1589                  * when zero.
 1590                  */
 1591                 if (t->c_ispeed == 0)
 1592                         t->c_ispeed = t->c_ospeed;
 1593 
 1594                 /* Discard any unsupported bits. */
 1595                 t->c_iflag &= TTYSUP_IFLAG;
 1596                 t->c_oflag &= TTYSUP_OFLAG;
 1597                 t->c_lflag &= TTYSUP_LFLAG;
 1598                 t->c_cflag &= TTYSUP_CFLAG;
 1599 
 1600                 /* Set terminal flags through tcsetattr(). */
 1601                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1602                         error = tty_drain(tp, 0);
 1603                         if (error)
 1604                                 return (error);
 1605                         if (cmd == TIOCSETAF)
 1606                                 tty_flush(tp, FREAD);
 1607                 }
 1608 
 1609                 /*
 1610                  * Only call param() when the flags really change.
 1611                  */
 1612                 if ((t->c_cflag & CIGNORE) == 0 &&
 1613                     (tp->t_termios.c_cflag != t->c_cflag ||
 1614                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
 1615                     (IXON|IXOFF|IXANY)) ||
 1616                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1617                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1618                         error = ttydevsw_param(tp, t);
 1619                         if (error)
 1620                                 return (error);
 1621 
 1622                         /* XXX: CLOCAL? */
 1623 
 1624                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1625                         tp->t_termios.c_ispeed = t->c_ispeed;
 1626                         tp->t_termios.c_ospeed = t->c_ospeed;
 1627 
 1628                         /* Baud rate has changed - update watermarks. */
 1629                         tty_watermarks(tp);
 1630                 }
 1631 
 1632                 /* Copy new non-device driver parameters. */
 1633                 tp->t_termios.c_iflag = t->c_iflag;
 1634                 tp->t_termios.c_oflag = t->c_oflag;
 1635                 tp->t_termios.c_lflag = t->c_lflag;
 1636                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1637 
 1638                 ttydisc_optimize(tp);
 1639 
 1640                 if ((t->c_lflag & ICANON) == 0) {
 1641                         /*
 1642                          * When in non-canonical mode, wake up all
 1643                          * readers. Canonicalize any partial input. VMIN
 1644                          * and VTIME could also be adjusted.
 1645                          */
 1646                         ttyinq_canonicalize(&tp->t_inq);
 1647                         tty_wakeup(tp, FREAD);
 1648                 }
 1649 
 1650                 /*
 1651                  * For packet mode: notify the PTY consumer that VSTOP
 1652                  * and VSTART may have been changed.
 1653                  */
 1654                 if (tp->t_termios.c_iflag & IXON &&
 1655                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1656                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1657                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1658                 else
 1659                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1660                 return (0);
 1661         }
 1662         case TIOCGETD:
 1663                 /* For compatibility - we only support TTYDISC. */
 1664                 *(int *)data = TTYDISC;
 1665                 return (0);
 1666         case TIOCGPGRP:
 1667                 if (!tty_is_ctty(tp, td->td_proc))
 1668                         return (ENOTTY);
 1669 
 1670                 if (tp->t_pgrp != NULL)
 1671                         *(int *)data = tp->t_pgrp->pg_id;
 1672                 else
 1673                         *(int *)data = NO_PID;
 1674                 return (0);
 1675         case TIOCGSID:
 1676                 if (!tty_is_ctty(tp, td->td_proc))
 1677                         return (ENOTTY);
 1678 
 1679                 MPASS(tp->t_session);
 1680                 *(int *)data = tp->t_session->s_sid;
 1681                 return (0);
 1682         case TIOCSCTTY: {
 1683                 struct proc *p = td->td_proc;
 1684 
 1685                 /* XXX: This looks awful. */
 1686                 tty_unlock(tp);
 1687                 sx_xlock(&proctree_lock);
 1688                 tty_lock(tp);
 1689 
 1690                 if (!SESS_LEADER(p)) {
 1691                         /* Only the session leader may do this. */
 1692                         sx_xunlock(&proctree_lock);
 1693                         return (EPERM);
 1694                 }
 1695 
 1696                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1697                         /* This is already our controlling TTY. */
 1698                         sx_xunlock(&proctree_lock);
 1699                         return (0);
 1700                 }
 1701 
 1702                 if (p->p_session->s_ttyp != NULL ||
 1703                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1704                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1705                         /*
 1706                          * There is already a relation between a TTY and
 1707                          * a session, or the caller is not the session
 1708                          * leader.
 1709                          *
 1710                          * Allow the TTY to be stolen when the vnode is
 1711                          * invalid, but the reference to the TTY is
 1712                          * still active.  This allows immediate reuse of
 1713                          * TTYs of which the session leader has been
 1714                          * killed or the TTY revoked.
 1715                          */
 1716                         sx_xunlock(&proctree_lock);
 1717                         return (EPERM);
 1718                 }
 1719 
 1720                 /* Connect the session to the TTY. */
 1721                 tp->t_session = p->p_session;
 1722                 tp->t_session->s_ttyp = tp;
 1723                 tp->t_sessioncnt++;
 1724 
 1725                 /* Assign foreground process group. */
 1726                 tp->t_pgrp = p->p_pgrp;
 1727                 PROC_LOCK(p);
 1728                 p->p_flag |= P_CONTROLT;
 1729                 PROC_UNLOCK(p);
 1730 
 1731                 sx_xunlock(&proctree_lock);
 1732                 return (0);
 1733         }
 1734         case TIOCSPGRP: {
 1735                 struct pgrp *pg;
 1736 
 1737                 /*
 1738                  * XXX: Temporarily unlock the TTY to locate the process
 1739                  * group. This code would be lot nicer if we would ever
 1740                  * decompose proctree_lock.
 1741                  */
 1742                 tty_unlock(tp);
 1743                 sx_slock(&proctree_lock);
 1744                 pg = pgfind(*(int *)data);
 1745                 if (pg != NULL)
 1746                         PGRP_UNLOCK(pg);
 1747                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1748                         sx_sunlock(&proctree_lock);
 1749                         tty_lock(tp);
 1750                         return (EPERM);
 1751                 }
 1752                 tty_lock(tp);
 1753 
 1754                 /*
 1755                  * Determine if this TTY is the controlling TTY after
 1756                  * relocking the TTY.
 1757                  */
 1758                 if (!tty_is_ctty(tp, td->td_proc)) {
 1759                         sx_sunlock(&proctree_lock);
 1760                         return (ENOTTY);
 1761                 }
 1762                 tp->t_pgrp = pg;
 1763                 sx_sunlock(&proctree_lock);
 1764 
 1765                 /* Wake up the background process groups. */
 1766                 cv_broadcast(&tp->t_bgwait);
 1767                 return (0);
 1768         }
 1769         case TIOCFLUSH: {
 1770                 int flags = *(int *)data;
 1771 
 1772                 if (flags == 0)
 1773                         flags = (FREAD|FWRITE);
 1774                 else
 1775                         flags &= (FREAD|FWRITE);
 1776                 tty_flush(tp, flags);
 1777                 return (0);
 1778         }
 1779         case TIOCDRAIN:
 1780                 /* Drain TTY output. */
 1781                 return tty_drain(tp, 0);
 1782         case TIOCCONS:
 1783                 /* Set terminal as console TTY. */
 1784                 if (*(int *)data) {
 1785                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1786                         if (error)
 1787                                 return (error);
 1788 
 1789                         /*
 1790                          * XXX: constty should really need to be locked!
 1791                          * XXX: allow disconnected constty's to be stolen!
 1792                          */
 1793 
 1794                         if (constty == tp)
 1795                                 return (0);
 1796                         if (constty != NULL)
 1797                                 return (EBUSY);
 1798 
 1799                         tty_unlock(tp);
 1800                         constty_set(tp);
 1801                         tty_lock(tp);
 1802                 } else if (constty == tp) {
 1803                         constty_clear();
 1804                 }
 1805                 return (0);
 1806         case TIOCGWINSZ:
 1807                 /* Obtain window size. */
 1808                 *(struct winsize*)data = tp->t_winsize;
 1809                 return (0);
 1810         case TIOCSWINSZ:
 1811                 /* Set window size. */
 1812                 tty_set_winsize(tp, data);
 1813                 return (0);
 1814         case TIOCEXCL:
 1815                 tp->t_flags |= TF_EXCLUDE;
 1816                 return (0);
 1817         case TIOCNXCL:
 1818                 tp->t_flags &= ~TF_EXCLUDE;
 1819                 return (0);
 1820         case TIOCSTOP:
 1821                 tp->t_flags |= TF_STOPPED;
 1822                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1823                 return (0);
 1824         case TIOCSTART:
 1825                 tp->t_flags &= ~TF_STOPPED;
 1826                 ttydevsw_outwakeup(tp);
 1827                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1828                 return (0);
 1829         case TIOCSTAT:
 1830                 tty_info(tp);
 1831                 return (0);
 1832         case TIOCSTI:
 1833                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1834                         return (EPERM);
 1835                 if (!tty_is_ctty(tp, td->td_proc) &&
 1836                     priv_check(td, PRIV_TTY_STI))
 1837                         return (EACCES);
 1838                 ttydisc_rint(tp, *(char *)data, 0);
 1839                 ttydisc_rint_done(tp);
 1840                 return (0);
 1841         }
 1842 
 1843 #ifdef COMPAT_43TTY
 1844         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1845 #else /* !COMPAT_43TTY */
 1846         return (ENOIOCTL);
 1847 #endif /* COMPAT_43TTY */
 1848 }
 1849 
 1850 int
 1851 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1852 {
 1853         int error;
 1854 
 1855         tty_lock_assert(tp, MA_OWNED);
 1856 
 1857         if (tty_gone(tp))
 1858                 return (ENXIO);
 1859 
 1860         error = ttydevsw_ioctl(tp, cmd, data, td);
 1861         if (error == ENOIOCTL)
 1862                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1863 
 1864         return (error);
 1865 }
 1866 
 1867 dev_t
 1868 tty_udev(struct tty *tp)
 1869 {
 1870 
 1871         if (tp->t_dev)
 1872                 return (dev2udev(tp->t_dev));
 1873         else
 1874                 return (NODEV);
 1875 }
 1876 
 1877 int
 1878 tty_checkoutq(struct tty *tp)
 1879 {
 1880 
 1881         /* 256 bytes should be enough to print a log message. */
 1882         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1883 }
 1884 
 1885 void
 1886 tty_hiwat_in_block(struct tty *tp)
 1887 {
 1888 
 1889         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1890             tp->t_termios.c_iflag & IXOFF &&
 1891             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1892                 /*
 1893                  * Input flow control. Only enter the high watermark when we
 1894                  * can successfully store the VSTOP character.
 1895                  */
 1896                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1897                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1898                         tp->t_flags |= TF_HIWAT_IN;
 1899         } else {
 1900                 /* No input flow control. */
 1901                 tp->t_flags |= TF_HIWAT_IN;
 1902         }
 1903 }
 1904 
 1905 void
 1906 tty_hiwat_in_unblock(struct tty *tp)
 1907 {
 1908 
 1909         if (tp->t_flags & TF_HIWAT_IN &&
 1910             tp->t_termios.c_iflag & IXOFF &&
 1911             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1912                 /*
 1913                  * Input flow control. Only leave the high watermark when we
 1914                  * can successfully store the VSTART character.
 1915                  */
 1916                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1917                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1918                         tp->t_flags &= ~TF_HIWAT_IN;
 1919         } else {
 1920                 /* No input flow control. */
 1921                 tp->t_flags &= ~TF_HIWAT_IN;
 1922         }
 1923 
 1924         if (!tty_gone(tp))
 1925                 ttydevsw_inwakeup(tp);
 1926 }
 1927 
 1928 /*
 1929  * TTY hooks interface.
 1930  */
 1931 
 1932 static int
 1933 ttyhook_defrint(struct tty *tp, char c, int flags)
 1934 {
 1935 
 1936         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1937                 return (-1);
 1938 
 1939         return (0);
 1940 }
 1941 
 1942 int
 1943 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
 1944     void *softc)
 1945 {
 1946         struct tty *tp;
 1947         struct file *fp;
 1948         struct cdev *dev;
 1949         struct cdevsw *cdp;
 1950         struct filedesc *fdp;
 1951         cap_rights_t rights;
 1952         int error, ref;
 1953 
 1954         /* Validate the file descriptor. */
 1955         fdp = p->p_fd;
 1956         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
 1957             0, &fp, NULL);
 1958         if (error != 0)
 1959                 return (error);
 1960         if (fp->f_ops == &badfileops) {
 1961                 error = EBADF;
 1962                 goto done1;
 1963         }
 1964 
 1965         /*
 1966          * Make sure the vnode is bound to a character device.
 1967          * Unlocked check for the vnode type is ok there, because we
 1968          * only shall prevent calling devvn_refthread on the file that
 1969          * never has been opened over a character device.
 1970          */
 1971         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1972                 error = EINVAL;
 1973                 goto done1;
 1974         }
 1975 
 1976         /* Make sure it is a TTY. */
 1977         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
 1978         if (cdp == NULL) {
 1979                 error = ENXIO;
 1980                 goto done1;
 1981         }
 1982         if (dev != fp->f_data) {
 1983                 error = ENXIO;
 1984                 goto done2;
 1985         }
 1986         if (cdp != &ttydev_cdevsw) {
 1987                 error = ENOTTY;
 1988                 goto done2;
 1989         }
 1990         tp = dev->si_drv1;
 1991 
 1992         /* Try to attach the hook to the TTY. */
 1993         error = EBUSY;
 1994         tty_lock(tp);
 1995         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1996         if (tp->t_flags & TF_HOOK)
 1997                 goto done3;
 1998 
 1999         tp->t_flags |= TF_HOOK;
 2000         tp->t_hook = th;
 2001         tp->t_hooksoftc = softc;
 2002         *rtp = tp;
 2003         error = 0;
 2004 
 2005         /* Maybe we can switch into bypass mode now. */
 2006         ttydisc_optimize(tp);
 2007 
 2008         /* Silently convert rint() calls to rint_bypass() when possible. */
 2009         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 2010                 th->th_rint = ttyhook_defrint;
 2011 
 2012 done3:  tty_unlock(tp);
 2013 done2:  dev_relthread(dev, ref);
 2014 done1:  fdrop(fp, curthread);
 2015         return (error);
 2016 }
 2017 
 2018 void
 2019 ttyhook_unregister(struct tty *tp)
 2020 {
 2021 
 2022         tty_lock_assert(tp, MA_OWNED);
 2023         MPASS(tp->t_flags & TF_HOOK);
 2024 
 2025         /* Disconnect the hook. */
 2026         tp->t_flags &= ~TF_HOOK;
 2027         tp->t_hook = NULL;
 2028 
 2029         /* Maybe we need to leave bypass mode. */
 2030         ttydisc_optimize(tp);
 2031 
 2032         /* Maybe deallocate the TTY as well. */
 2033         tty_rel_free(tp);
 2034 }
 2035 
 2036 /*
 2037  * /dev/console handling.
 2038  */
 2039 
 2040 static int
 2041 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 2042 {
 2043         struct tty *tp;
 2044 
 2045         /* System has no console device. */
 2046         if (dev_console_filename == NULL)
 2047                 return (ENXIO);
 2048 
 2049         /* Look up corresponding TTY by device name. */
 2050         sx_slock(&tty_list_sx);
 2051         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2052                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 2053                         dev_console->si_drv1 = tp;
 2054                         break;
 2055                 }
 2056         }
 2057         sx_sunlock(&tty_list_sx);
 2058 
 2059         /* System console has no TTY associated. */
 2060         if (dev_console->si_drv1 == NULL)
 2061                 return (ENXIO);
 2062 
 2063         return (ttydev_open(dev, oflags, devtype, td));
 2064 }
 2065 
 2066 static int
 2067 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 2068 {
 2069 
 2070         log_console(uio);
 2071 
 2072         return (ttydev_write(dev, uio, ioflag));
 2073 }
 2074 
 2075 /*
 2076  * /dev/console is a little different than normal TTY's.  When opened,
 2077  * it determines which TTY to use.  When data gets written to it, it
 2078  * will be logged in the kernel message buffer.
 2079  */
 2080 static struct cdevsw ttyconsdev_cdevsw = {
 2081         .d_version      = D_VERSION,
 2082         .d_open         = ttyconsdev_open,
 2083         .d_close        = ttydev_close,
 2084         .d_read         = ttydev_read,
 2085         .d_write        = ttyconsdev_write,
 2086         .d_ioctl        = ttydev_ioctl,
 2087         .d_kqfilter     = ttydev_kqfilter,
 2088         .d_poll         = ttydev_poll,
 2089         .d_mmap         = ttydev_mmap,
 2090         .d_name         = "ttyconsdev",
 2091         .d_flags        = D_TTY,
 2092 };
 2093 
 2094 static void
 2095 ttyconsdev_init(void *unused __unused)
 2096 {
 2097 
 2098         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
 2099             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
 2100 }
 2101 
 2102 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 2103 
 2104 void
 2105 ttyconsdev_select(const char *name)
 2106 {
 2107 
 2108         dev_console_filename = name;
 2109 }
 2110 
 2111 /*
 2112  * Debugging routines.
 2113  */
 2114 
 2115 #include "opt_ddb.h"
 2116 #ifdef DDB
 2117 #include <ddb/ddb.h>
 2118 #include <ddb/db_sym.h>
 2119 
 2120 static const struct {
 2121         int flag;
 2122         char val;
 2123 } ttystates[] = {
 2124 #if 0
 2125         { TF_NOPREFIX,          'N' },
 2126 #endif
 2127         { TF_INITLOCK,          'I' },
 2128         { TF_CALLOUT,           'C' },
 2129 
 2130         /* Keep these together -> 'Oi' and 'Oo'. */
 2131         { TF_OPENED,            'O' },
 2132         { TF_OPENED_IN,         'i' },
 2133         { TF_OPENED_OUT,        'o' },
 2134         { TF_OPENED_CONS,       'c' },
 2135 
 2136         { TF_GONE,              'G' },
 2137         { TF_OPENCLOSE,         'B' },
 2138         { TF_ASYNC,             'Y' },
 2139         { TF_LITERAL,           'L' },
 2140 
 2141         /* Keep these together -> 'Hi' and 'Ho'. */
 2142         { TF_HIWAT,             'H' },
 2143         { TF_HIWAT_IN,          'i' },
 2144         { TF_HIWAT_OUT,         'o' },
 2145 
 2146         { TF_STOPPED,           'S' },
 2147         { TF_EXCLUDE,           'X' },
 2148         { TF_BYPASS,            'l' },
 2149         { TF_ZOMBIE,            'Z' },
 2150         { TF_HOOK,              's' },
 2151 
 2152         /* Keep these together -> 'bi' and 'bo'. */
 2153         { TF_BUSY,              'b' },
 2154         { TF_BUSY_IN,           'i' },
 2155         { TF_BUSY_OUT,          'o' },
 2156 
 2157         { 0,                    '\0'},
 2158 };
 2159 
 2160 #define TTY_FLAG_BITS \
 2161         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
 2162         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
 2163         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
 2164         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
 2165         "\21HOOK\22BUSY_IN\23BUSY_OUT"
 2166 
 2167 #define DB_PRINTSYM(name, addr) \
 2168         db_printf("%s  " #name ": ", sep); \
 2169         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 2170         db_printf("\n");
 2171 
 2172 static void
 2173 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2174 {
 2175 
 2176         db_printf("%sdevsw: ", sep);
 2177         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2178         db_printf(" (%p)\n", tsw);
 2179         DB_PRINTSYM(open, tsw->tsw_open);
 2180         DB_PRINTSYM(close, tsw->tsw_close);
 2181         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2182         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2183         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2184         DB_PRINTSYM(param, tsw->tsw_param);
 2185         DB_PRINTSYM(modem, tsw->tsw_modem);
 2186         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2187         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2188         DB_PRINTSYM(free, tsw->tsw_free);
 2189 }
 2190 
 2191 static void
 2192 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2193 {
 2194 
 2195         db_printf("%shook: ", sep);
 2196         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2197         db_printf(" (%p)\n", th);
 2198         if (th == NULL)
 2199                 return;
 2200         DB_PRINTSYM(rint, th->th_rint);
 2201         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2202         DB_PRINTSYM(rint_done, th->th_rint_done);
 2203         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2204         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2205         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2206         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2207         DB_PRINTSYM(close, th->th_close);
 2208 }
 2209 
 2210 static void
 2211 _db_show_termios(const char *name, const struct termios *t)
 2212 {
 2213 
 2214         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2215             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2216             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2217             t->c_ispeed, t->c_ospeed);
 2218 }
 2219 
 2220 /* DDB command to show TTY statistics. */
 2221 DB_SHOW_COMMAND(tty, db_show_tty)
 2222 {
 2223         struct tty *tp;
 2224 
 2225         if (!have_addr) {
 2226                 db_printf("usage: show tty <addr>\n");
 2227                 return;
 2228         }
 2229         tp = (struct tty *)addr;
 2230 
 2231         db_printf("%p: %s\n", tp, tty_devname(tp));
 2232         db_printf("\tmtx: %p\n", tp->t_mtx);
 2233         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
 2234         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2235 
 2236         /* Buffering mechanisms. */
 2237         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2238             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2239             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2240             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2241         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2242             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2243             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2244         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2245         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2246         _db_show_termios("\ttermios", &tp->t_termios);
 2247         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2248             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2249             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2250         db_printf("\tcolumn: %u\n", tp->t_column);
 2251         db_printf("\twritepos: %u\n", tp->t_writepos);
 2252         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2253 
 2254         /* Init/lock-state devices. */
 2255         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2256         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2257         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2258         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2259 
 2260         /* Hooks */
 2261         _db_show_devsw("\t", tp->t_devsw);
 2262         _db_show_hooks("\t", tp->t_hook);
 2263 
 2264         /* Process info. */
 2265         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2266             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2267             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2268         db_printf("\tsession: %p", tp->t_session);
 2269         if (tp->t_session != NULL)
 2270             db_printf(" count %u leader %p tty %p sid %d login %s",
 2271                 tp->t_session->s_count, tp->t_session->s_leader,
 2272                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2273                 tp->t_session->s_login);
 2274         db_printf("\n");
 2275         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2276         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2277         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2278         db_printf("\tdev: %p\n", tp->t_dev);
 2279 }
 2280 
 2281 /* DDB command to list TTYs. */
 2282 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2283 {
 2284         struct tty *tp;
 2285         size_t isiz, osiz;
 2286         int i, j;
 2287 
 2288         /* Make the output look like `pstat -t'. */
 2289         db_printf("PTR        ");
 2290 #if defined(__LP64__)
 2291         db_printf("        ");
 2292 #endif
 2293         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2294             "COL  SESS  PGID STATE\n");
 2295 
 2296         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2297                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2298                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2299 
 2300                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
 2301                     "%5d ", tp, tty_devname(tp), isiz,
 2302                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2303                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2304                     isiz - tp->t_inlow, osiz,
 2305                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2306                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
 2307                     tp->t_session ? tp->t_session->s_sid : 0,
 2308                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2309 
 2310                 /* Flag bits. */
 2311                 for (i = j = 0; ttystates[i].flag; i++)
 2312                         if (tp->t_flags & ttystates[i].flag) {
 2313                                 db_printf("%c", ttystates[i].val);
 2314                                 j++;
 2315                         }
 2316                 if (j == 0)
 2317                         db_printf("-");
 2318                 db_printf("\n");
 2319         }
 2320 }
 2321 #endif /* DDB */

Cache object: 7d2fbe35cff47fb2e0998be2ac3aa289


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