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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 259663 2013-12-20 19:45:51Z glebius $");
   32 
   33 #include "opt_capsicum.h"
   34 #include "opt_compat.h"
   35 
   36 #include <sys/param.h>
   37 #include <sys/capability.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)
  127 {
  128         int error;
  129 
  130         if (ttyhook_hashook(tp, getc_inject))
  131                 /* buffer is inaccessible */
  132                 return (0);
  133 
  134         while (ttyoutq_bytesused(&tp->t_outq) > 0) {
  135                 ttydevsw_outwakeup(tp);
  136                 /* Could be handled synchronously. */
  137                 if (ttyoutq_bytesused(&tp->t_outq) == 0)
  138                         return (0);
  139 
  140                 /* Wait for data to be drained. */
  141                 error = tty_wait(tp, &tp->t_outwait);
  142                 if (error)
  143                         return (error);
  144         }
  145 
  146         return (0);
  147 }
  148 
  149 /*
  150  * Though ttydev_enter() and ttydev_leave() seem to be related, they
  151  * don't have to be used together. ttydev_enter() is used by the cdev
  152  * operations to prevent an actual operation from being processed when
  153  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
  154  * and ttydev_close() to determine whether per-TTY data should be
  155  * deallocated.
  156  */
  157 
  158 static __inline int
  159 ttydev_enter(struct tty *tp)
  160 {
  161         tty_lock(tp);
  162 
  163         if (tty_gone(tp) || !tty_opened(tp)) {
  164                 /* Device is already gone. */
  165                 tty_unlock(tp);
  166                 return (ENXIO);
  167         }
  168 
  169         return (0);
  170 }
  171 
  172 static void
  173 ttydev_leave(struct tty *tp)
  174 {
  175         tty_lock_assert(tp, MA_OWNED);
  176 
  177         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
  178                 /* Device is still opened somewhere. */
  179                 tty_unlock(tp);
  180                 return;
  181         }
  182 
  183         tp->t_flags |= TF_OPENCLOSE;
  184 
  185         /* Stop asynchronous I/O. */
  186         funsetown(&tp->t_sigio);
  187 
  188         /* Remove console TTY. */
  189         if (constty == tp)
  190                 constty_clear();
  191 
  192         /* Drain any output. */
  193         MPASS((tp->t_flags & TF_STOPPED) == 0);
  194         if (!tty_gone(tp)) {
  195                 while (tty_drain(tp) == ERESTART)
  196                         ;
  197         }
  198 
  199         ttydisc_close(tp);
  200 
  201         /* Destroy associated buffers already. */
  202         ttyinq_free(&tp->t_inq);
  203         tp->t_inlow = 0;
  204         ttyoutq_free(&tp->t_outq);
  205         tp->t_outlow = 0;
  206 
  207         knlist_clear(&tp->t_inpoll.si_note, 1);
  208         knlist_clear(&tp->t_outpoll.si_note, 1);
  209 
  210         if (!tty_gone(tp))
  211                 ttydevsw_close(tp);
  212 
  213         tp->t_flags &= ~TF_OPENCLOSE;
  214         cv_broadcast(&tp->t_dcdwait);
  215         tty_rel_free(tp);
  216 }
  217 
  218 /*
  219  * Operations that are exposed through the character device in /dev.
  220  */
  221 static int
  222 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  223 {
  224         struct tty *tp;
  225         int error = 0;
  226 
  227         while ((tp = dev->si_drv1) == NULL) {
  228                 error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
  229                 if (error != EWOULDBLOCK)
  230                         return (error);
  231         }
  232 
  233         tty_lock(tp);
  234         if (tty_gone(tp)) {
  235                 /* Device is already gone. */
  236                 tty_unlock(tp);
  237                 return (ENXIO);
  238         }
  239 
  240         /*
  241          * Block when other processes are currently opening or closing
  242          * the TTY.
  243          */
  244         while (tp->t_flags & TF_OPENCLOSE) {
  245                 error = tty_wait(tp, &tp->t_dcdwait);
  246                 if (error != 0) {
  247                         tty_unlock(tp);
  248                         return (error);
  249                 }
  250         }
  251         tp->t_flags |= TF_OPENCLOSE;
  252 
  253         /*
  254          * Make sure the "tty" and "cua" device cannot be opened at the
  255          * same time.
  256          */
  257         if (TTY_CALLOUT(tp, dev)) {
  258                 if (tp->t_flags & TF_OPENED_IN) {
  259                         error = EBUSY;
  260                         goto done;
  261                 }
  262         } else {
  263                 if (tp->t_flags & TF_OPENED_OUT) {
  264                         error = EBUSY;
  265                         goto done;
  266                 }
  267         }
  268 
  269         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
  270                 error = EBUSY;
  271                 goto done;
  272         }
  273 
  274         if (!tty_opened(tp)) {
  275                 /* Set proper termios flags. */
  276                 if (TTY_CALLOUT(tp, dev))
  277                         tp->t_termios = tp->t_termios_init_out;
  278                 else
  279                         tp->t_termios = tp->t_termios_init_in;
  280                 ttydevsw_param(tp, &tp->t_termios);
  281                 /* Prevent modem control on callout devices and /dev/console. */
  282                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
  283                         tp->t_termios.c_cflag |= CLOCAL;
  284 
  285                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
  286 
  287                 error = ttydevsw_open(tp);
  288                 if (error != 0)
  289                         goto done;
  290 
  291                 ttydisc_open(tp);
  292                 tty_watermarks(tp); /* XXXGL: drops lock */
  293         }
  294 
  295         /* Wait for Carrier Detect. */
  296         if ((oflags & O_NONBLOCK) == 0 &&
  297             (tp->t_termios.c_cflag & CLOCAL) == 0) {
  298                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
  299                         error = tty_wait(tp, &tp->t_dcdwait);
  300                         if (error != 0)
  301                                 goto done;
  302                 }
  303         }
  304 
  305         if (dev == dev_console)
  306                 tp->t_flags |= TF_OPENED_CONS;
  307         else if (TTY_CALLOUT(tp, dev))
  308                 tp->t_flags |= TF_OPENED_OUT;
  309         else
  310                 tp->t_flags |= TF_OPENED_IN;
  311 
  312 done:   tp->t_flags &= ~TF_OPENCLOSE;
  313         cv_broadcast(&tp->t_dcdwait);
  314         ttydev_leave(tp);
  315 
  316         return (error);
  317 }
  318 
  319 static int
  320 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
  321 {
  322         struct tty *tp = dev->si_drv1;
  323 
  324         tty_lock(tp);
  325 
  326         /*
  327          * Don't actually close the device if it is being used as the
  328          * console.
  329          */
  330         MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
  331         if (dev == dev_console)
  332                 tp->t_flags &= ~TF_OPENED_CONS;
  333         else
  334                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
  335 
  336         if (tp->t_flags & TF_OPENED) {
  337                 tty_unlock(tp);
  338                 return (0);
  339         }
  340 
  341         /*
  342          * This can only be called once. The callin and the callout
  343          * devices cannot be opened at the same time.
  344          */
  345         tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
  346 
  347         /* Properly wake up threads that are stuck - revoke(). */
  348         tp->t_revokecnt++;
  349         tty_wakeup(tp, FREAD|FWRITE);
  350         cv_broadcast(&tp->t_bgwait);
  351         cv_broadcast(&tp->t_dcdwait);
  352 
  353         ttydev_leave(tp);
  354 
  355         return (0);
  356 }
  357 
  358 static __inline int
  359 tty_is_ctty(struct tty *tp, struct proc *p)
  360 {
  361         tty_lock_assert(tp, MA_OWNED);
  362 
  363         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
  364 }
  365 
  366 int
  367 tty_wait_background(struct tty *tp, struct thread *td, int sig)
  368 {
  369         struct proc *p = td->td_proc;
  370         struct pgrp *pg;
  371         ksiginfo_t ksi;
  372         int error;
  373 
  374         MPASS(sig == SIGTTIN || sig == SIGTTOU);
  375         tty_lock_assert(tp, MA_OWNED);
  376 
  377         for (;;) {
  378                 PROC_LOCK(p);
  379                 /*
  380                  * The process should only sleep, when:
  381                  * - This terminal is the controling terminal
  382                  * - Its process group is not the foreground process
  383                  *   group
  384                  * - The parent process isn't waiting for the child to
  385                  *   exit
  386                  * - the signal to send to the process isn't masked
  387                  */
  388                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
  389                         /* Allow the action to happen. */
  390                         PROC_UNLOCK(p);
  391                         return (0);
  392                 }
  393 
  394                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
  395                     SIGISMEMBER(td->td_sigmask, sig)) {
  396                         /* Only allow them in write()/ioctl(). */
  397                         PROC_UNLOCK(p);
  398                         return (sig == SIGTTOU ? 0 : EIO);
  399                 }
  400 
  401                 pg = p->p_pgrp;
  402                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
  403                         /* Don't allow the action to happen. */
  404                         PROC_UNLOCK(p);
  405                         return (EIO);
  406                 }
  407                 PROC_UNLOCK(p);
  408 
  409                 /*
  410                  * Send the signal and sleep until we're the new
  411                  * foreground process group.
  412                  */
  413                 if (sig != 0) {
  414                         ksiginfo_init(&ksi);
  415                         ksi.ksi_code = SI_KERNEL;
  416                         ksi.ksi_signo = sig;
  417                         sig = 0;
  418                 }
  419                 PGRP_LOCK(pg);
  420                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
  421                 PGRP_UNLOCK(pg);
  422 
  423                 error = tty_wait(tp, &tp->t_bgwait);
  424                 if (error)
  425                         return (error);
  426         }
  427 }
  428 
  429 static int
  430 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
  431 {
  432         struct tty *tp = dev->si_drv1;
  433         int error;
  434 
  435         error = ttydev_enter(tp);
  436         if (error)
  437                 goto done;
  438         error = ttydisc_read(tp, uio, ioflag);
  439         tty_unlock(tp);
  440 
  441         /*
  442          * The read() call should not throw an error when the device is
  443          * being destroyed. Silently convert it to an EOF.
  444          */
  445 done:   if (error == ENXIO)
  446                 error = 0;
  447         return (error);
  448 }
  449 
  450 static int
  451 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  452 {
  453         struct tty *tp = dev->si_drv1;
  454         int error;
  455 
  456         error = ttydev_enter(tp);
  457         if (error)
  458                 return (error);
  459 
  460         if (tp->t_termios.c_lflag & TOSTOP) {
  461                 error = tty_wait_background(tp, curthread, SIGTTOU);
  462                 if (error)
  463                         goto done;
  464         }
  465 
  466         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  467                 /* Allow non-blocking writes to bypass serialization. */
  468                 error = ttydisc_write(tp, uio, ioflag);
  469         } else {
  470                 /* Serialize write() calls. */
  471                 while (tp->t_flags & TF_BUSY_OUT) {
  472                         error = tty_wait(tp, &tp->t_outserwait);
  473                         if (error)
  474                                 goto done;
  475                 }
  476 
  477                 tp->t_flags |= TF_BUSY_OUT;
  478                 error = ttydisc_write(tp, uio, ioflag);
  479                 tp->t_flags &= ~TF_BUSY_OUT;
  480                 cv_signal(&tp->t_outserwait);
  481         }
  482 
  483 done:   tty_unlock(tp);
  484         return (error);
  485 }
  486 
  487 static int
  488 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  489     struct thread *td)
  490 {
  491         struct tty *tp = dev->si_drv1;
  492         int error;
  493 
  494         error = ttydev_enter(tp);
  495         if (error)
  496                 return (error);
  497 
  498         switch (cmd) {
  499         case TIOCCBRK:
  500         case TIOCCONS:
  501         case TIOCDRAIN:
  502         case TIOCEXCL:
  503         case TIOCFLUSH:
  504         case TIOCNXCL:
  505         case TIOCSBRK:
  506         case TIOCSCTTY:
  507         case TIOCSETA:
  508         case TIOCSETAF:
  509         case TIOCSETAW:
  510         case TIOCSPGRP:
  511         case TIOCSTART:
  512         case TIOCSTAT:
  513         case TIOCSTI:
  514         case TIOCSTOP:
  515         case TIOCSWINSZ:
  516 #if 0
  517         case TIOCSDRAINWAIT:
  518         case TIOCSETD:
  519 #endif
  520 #ifdef COMPAT_43TTY
  521         case  TIOCLBIC:
  522         case  TIOCLBIS:
  523         case  TIOCLSET:
  524         case  TIOCSETC:
  525         case OTIOCSETD:
  526         case  TIOCSETN:
  527         case  TIOCSETP:
  528         case  TIOCSLTC:
  529 #endif /* COMPAT_43TTY */
  530                 /*
  531                  * If the ioctl() causes the TTY to be modified, let it
  532                  * wait in the background.
  533                  */
  534                 error = tty_wait_background(tp, curthread, SIGTTOU);
  535                 if (error)
  536                         goto done;
  537         }
  538 
  539         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  540                 struct termios *old = &tp->t_termios;
  541                 struct termios *new = (struct termios *)data;
  542                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  543                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  544                 int cc;
  545 
  546                 /*
  547                  * Lock state devices.  Just overwrite the values of the
  548                  * commands that are currently in use.
  549                  */
  550                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  551                     (new->c_iflag & ~lock->c_iflag);
  552                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  553                     (new->c_oflag & ~lock->c_oflag);
  554                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  555                     (new->c_cflag & ~lock->c_cflag);
  556                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  557                     (new->c_lflag & ~lock->c_lflag);
  558                 for (cc = 0; cc < NCCS; ++cc)
  559                         if (lock->c_cc[cc])
  560                                 new->c_cc[cc] = old->c_cc[cc];
  561                 if (lock->c_ispeed)
  562                         new->c_ispeed = old->c_ispeed;
  563                 if (lock->c_ospeed)
  564                         new->c_ospeed = old->c_ospeed;
  565         }
  566 
  567         error = tty_ioctl(tp, cmd, data, fflag, td);
  568 done:   tty_unlock(tp);
  569 
  570         return (error);
  571 }
  572 
  573 static int
  574 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  575 {
  576         struct tty *tp = dev->si_drv1;
  577         int error, revents = 0;
  578 
  579         error = ttydev_enter(tp);
  580         if (error)
  581                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  582 
  583         if (events & (POLLIN|POLLRDNORM)) {
  584                 /* See if we can read something. */
  585                 if (ttydisc_read_poll(tp) > 0)
  586                         revents |= events & (POLLIN|POLLRDNORM);
  587         }
  588 
  589         if (tp->t_flags & TF_ZOMBIE) {
  590                 /* Hangup flag on zombie state. */
  591                 revents |= POLLHUP;
  592         } else if (events & (POLLOUT|POLLWRNORM)) {
  593                 /* See if we can write something. */
  594                 if (ttydisc_write_poll(tp) > 0)
  595                         revents |= events & (POLLOUT|POLLWRNORM);
  596         }
  597 
  598         if (revents == 0) {
  599                 if (events & (POLLIN|POLLRDNORM))
  600                         selrecord(td, &tp->t_inpoll);
  601                 if (events & (POLLOUT|POLLWRNORM))
  602                         selrecord(td, &tp->t_outpoll);
  603         }
  604 
  605         tty_unlock(tp);
  606 
  607         return (revents);
  608 }
  609 
  610 static int
  611 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  612     int nprot, vm_memattr_t *memattr)
  613 {
  614         struct tty *tp = dev->si_drv1;
  615         int error;
  616 
  617         /* Handle mmap() through the driver. */
  618 
  619         error = ttydev_enter(tp);
  620         if (error)
  621                 return (-1);
  622         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
  623         tty_unlock(tp);
  624 
  625         return (error);
  626 }
  627 
  628 /*
  629  * kqueue support.
  630  */
  631 
  632 static void
  633 tty_kqops_read_detach(struct knote *kn)
  634 {
  635         struct tty *tp = kn->kn_hook;
  636 
  637         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  638 }
  639 
  640 static int
  641 tty_kqops_read_event(struct knote *kn, long hint)
  642 {
  643         struct tty *tp = kn->kn_hook;
  644 
  645         tty_lock_assert(tp, MA_OWNED);
  646 
  647         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  648                 kn->kn_flags |= EV_EOF;
  649                 return (1);
  650         } else {
  651                 kn->kn_data = ttydisc_read_poll(tp);
  652                 return (kn->kn_data > 0);
  653         }
  654 }
  655 
  656 static void
  657 tty_kqops_write_detach(struct knote *kn)
  658 {
  659         struct tty *tp = kn->kn_hook;
  660 
  661         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  662 }
  663 
  664 static int
  665 tty_kqops_write_event(struct knote *kn, long hint)
  666 {
  667         struct tty *tp = kn->kn_hook;
  668 
  669         tty_lock_assert(tp, MA_OWNED);
  670 
  671         if (tty_gone(tp)) {
  672                 kn->kn_flags |= EV_EOF;
  673                 return (1);
  674         } else {
  675                 kn->kn_data = ttydisc_write_poll(tp);
  676                 return (kn->kn_data > 0);
  677         }
  678 }
  679 
  680 static struct filterops tty_kqops_read = {
  681         .f_isfd = 1,
  682         .f_detach = tty_kqops_read_detach,
  683         .f_event = tty_kqops_read_event,
  684 };
  685 static struct filterops tty_kqops_write = {
  686         .f_isfd = 1,
  687         .f_detach = tty_kqops_write_detach,
  688         .f_event = tty_kqops_write_event,
  689 };
  690 
  691 static int
  692 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  693 {
  694         struct tty *tp = dev->si_drv1;
  695         int error;
  696 
  697         error = ttydev_enter(tp);
  698         if (error)
  699                 return (error);
  700 
  701         switch (kn->kn_filter) {
  702         case EVFILT_READ:
  703                 kn->kn_hook = tp;
  704                 kn->kn_fop = &tty_kqops_read;
  705                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  706                 break;
  707         case EVFILT_WRITE:
  708                 kn->kn_hook = tp;
  709                 kn->kn_fop = &tty_kqops_write;
  710                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  711                 break;
  712         default:
  713                 error = EINVAL;
  714                 break;
  715         }
  716 
  717         tty_unlock(tp);
  718         return (error);
  719 }
  720 
  721 static struct cdevsw ttydev_cdevsw = {
  722         .d_version      = D_VERSION,
  723         .d_open         = ttydev_open,
  724         .d_close        = ttydev_close,
  725         .d_read         = ttydev_read,
  726         .d_write        = ttydev_write,
  727         .d_ioctl        = ttydev_ioctl,
  728         .d_kqfilter     = ttydev_kqfilter,
  729         .d_poll         = ttydev_poll,
  730         .d_mmap         = ttydev_mmap,
  731         .d_name         = "ttydev",
  732         .d_flags        = D_TTY,
  733 };
  734 
  735 /*
  736  * Init/lock-state devices
  737  */
  738 
  739 static int
  740 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  741 {
  742         struct tty *tp;
  743         int error = 0;
  744 
  745         while ((tp = dev->si_drv1) == NULL) {
  746                 error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
  747                 if (error != EWOULDBLOCK)
  748                         return (error);
  749         }
  750         tty_lock(tp);
  751         if (tty_gone(tp))
  752                 error = ENODEV;
  753         tty_unlock(tp);
  754 
  755         return (error);
  756 }
  757 
  758 static int
  759 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
  760 {
  761         return (0);
  762 }
  763 
  764 static int
  765 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
  766 {
  767         return (ENODEV);
  768 }
  769 
  770 static int
  771 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  772     struct thread *td)
  773 {
  774         struct tty *tp = dev->si_drv1;
  775         int error;
  776 
  777         tty_lock(tp);
  778         if (tty_gone(tp)) {
  779                 error = ENODEV;
  780                 goto done;
  781         }
  782 
  783         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
  784         if (error != ENOIOCTL)
  785                 goto done;
  786         error = 0;
  787 
  788         switch (cmd) {
  789         case TIOCGETA:
  790                 /* Obtain terminal flags through tcgetattr(). */
  791                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  792                 break;
  793         case TIOCSETA:
  794                 /* Set terminal flags through tcsetattr(). */
  795                 error = priv_check(td, PRIV_TTY_SETA);
  796                 if (error)
  797                         break;
  798                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  799                 break;
  800         case TIOCGETD:
  801                 *(int *)data = TTYDISC;
  802                 break;
  803         case TIOCGWINSZ:
  804                 bzero(data, sizeof(struct winsize));
  805                 break;
  806         default:
  807                 error = ENOTTY;
  808         }
  809 
  810 done:   tty_unlock(tp);
  811         return (error);
  812 }
  813 
  814 static struct cdevsw ttyil_cdevsw = {
  815         .d_version      = D_VERSION,
  816         .d_open         = ttyil_open,
  817         .d_close        = ttyil_close,
  818         .d_read         = ttyil_rdwr,
  819         .d_write        = ttyil_rdwr,
  820         .d_ioctl        = ttyil_ioctl,
  821         .d_name         = "ttyil",
  822         .d_flags        = D_TTY,
  823 };
  824 
  825 static void
  826 tty_init_termios(struct tty *tp)
  827 {
  828         struct termios *t = &tp->t_termios_init_in;
  829 
  830         t->c_cflag = TTYDEF_CFLAG;
  831         t->c_iflag = TTYDEF_IFLAG;
  832         t->c_lflag = TTYDEF_LFLAG;
  833         t->c_oflag = TTYDEF_OFLAG;
  834         t->c_ispeed = TTYDEF_SPEED;
  835         t->c_ospeed = TTYDEF_SPEED;
  836         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  837 
  838         tp->t_termios_init_out = *t;
  839 }
  840 
  841 void
  842 tty_init_console(struct tty *tp, speed_t s)
  843 {
  844         struct termios *ti = &tp->t_termios_init_in;
  845         struct termios *to = &tp->t_termios_init_out;
  846 
  847         if (s != 0) {
  848                 ti->c_ispeed = ti->c_ospeed = s;
  849                 to->c_ispeed = to->c_ospeed = s;
  850         }
  851 
  852         ti->c_cflag |= CLOCAL;
  853         to->c_cflag |= CLOCAL;
  854 }
  855 
  856 /*
  857  * Standard device routine implementations, mostly meant for
  858  * pseudo-terminal device drivers. When a driver creates a new terminal
  859  * device class, missing routines are patched.
  860  */
  861 
  862 static int
  863 ttydevsw_defopen(struct tty *tp)
  864 {
  865 
  866         return (0);
  867 }
  868 
  869 static void
  870 ttydevsw_defclose(struct tty *tp)
  871 {
  872 }
  873 
  874 static void
  875 ttydevsw_defoutwakeup(struct tty *tp)
  876 {
  877 
  878         panic("Terminal device has output, while not implemented");
  879 }
  880 
  881 static void
  882 ttydevsw_definwakeup(struct tty *tp)
  883 {
  884 }
  885 
  886 static int
  887 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
  888 {
  889 
  890         return (ENOIOCTL);
  891 }
  892 
  893 static int
  894 ttydevsw_defcioctl(struct tty *tp, int unit, u_long cmd, caddr_t data, struct thread *td)
  895 {
  896 
  897         return (ENOIOCTL);
  898 }
  899 
  900 static int
  901 ttydevsw_defparam(struct tty *tp, struct termios *t)
  902 {
  903 
  904         /*
  905          * Allow the baud rate to be adjusted for pseudo-devices, but at
  906          * least restrict it to 115200 to prevent excessive buffer
  907          * usage.  Also disallow 0, to prevent foot shooting.
  908          */
  909         if (t->c_ispeed < B50)
  910                 t->c_ispeed = B50;
  911         else if (t->c_ispeed > B115200)
  912                 t->c_ispeed = B115200;
  913         if (t->c_ospeed < B50)
  914                 t->c_ospeed = B50;
  915         else if (t->c_ospeed > B115200)
  916                 t->c_ospeed = B115200;
  917         t->c_cflag |= CREAD;
  918 
  919         return (0);
  920 }
  921 
  922 static int
  923 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
  924 {
  925 
  926         /* Simulate a carrier to make the TTY layer happy. */
  927         return (SER_DCD);
  928 }
  929 
  930 static int
  931 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
  932     int nprot, vm_memattr_t *memattr)
  933 {
  934 
  935         return (-1);
  936 }
  937 
  938 static void
  939 ttydevsw_defpktnotify(struct tty *tp, char event)
  940 {
  941 }
  942 
  943 static void
  944 ttydevsw_deffree(void *softc)
  945 {
  946 
  947         panic("Terminal device freed without a free-handler");
  948 }
  949 
  950 /*
  951  * TTY allocation and deallocation. TTY devices can be deallocated when
  952  * the driver doesn't use it anymore, when the TTY isn't a session's
  953  * controlling TTY and when the device node isn't opened through devfs.
  954  */
  955 
  956 struct tty *
  957 tty_alloc(struct ttydevsw *tsw, void *sc)
  958 {
  959 
  960         return (tty_alloc_mutex(tsw, sc, NULL));
  961 }
  962 
  963 struct tty *
  964 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
  965 {
  966         struct tty *tp;
  967 
  968         /* Make sure the driver defines all routines. */
  969 #define PATCH_FUNC(x) do {                              \
  970         if (tsw->tsw_ ## x == NULL)                     \
  971                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
  972 } while (0)
  973         PATCH_FUNC(open);
  974         PATCH_FUNC(close);
  975         PATCH_FUNC(outwakeup);
  976         PATCH_FUNC(inwakeup);
  977         PATCH_FUNC(ioctl);
  978         PATCH_FUNC(cioctl);
  979         PATCH_FUNC(param);
  980         PATCH_FUNC(modem);
  981         PATCH_FUNC(mmap);
  982         PATCH_FUNC(pktnotify);
  983         PATCH_FUNC(free);
  984 #undef PATCH_FUNC
  985 
  986         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
  987         tp->t_devsw = tsw;
  988         tp->t_devswsoftc = sc;
  989         tp->t_flags = tsw->tsw_flags;
  990 
  991         tty_init_termios(tp);
  992 
  993         cv_init(&tp->t_inwait, "ttyin");
  994         cv_init(&tp->t_outwait, "ttyout");
  995         cv_init(&tp->t_outserwait, "ttyosr");
  996         cv_init(&tp->t_bgwait, "ttybg");
  997         cv_init(&tp->t_dcdwait, "ttydcd");
  998 
  999         /* Allow drivers to use a custom mutex to lock the TTY. */
 1000         if (mutex != NULL) {
 1001                 tp->t_mtx = mutex;
 1002         } else {
 1003                 tp->t_mtx = &tp->t_mtxobj;
 1004                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
 1005         }
 1006 
 1007         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 1008         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 1009 
 1010         return (tp);
 1011 }
 1012 
 1013 static void
 1014 tty_dealloc(void *arg)
 1015 {
 1016         struct tty *tp = arg;
 1017 
 1018         /* Make sure we haven't leaked buffers. */
 1019         MPASS(ttyinq_getsize(&tp->t_inq) == 0);
 1020         MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
 1021 
 1022         seldrain(&tp->t_inpoll);
 1023         seldrain(&tp->t_outpoll);
 1024         knlist_destroy(&tp->t_inpoll.si_note);
 1025         knlist_destroy(&tp->t_outpoll.si_note);
 1026 
 1027         cv_destroy(&tp->t_inwait);
 1028         cv_destroy(&tp->t_outwait);
 1029         cv_destroy(&tp->t_bgwait);
 1030         cv_destroy(&tp->t_dcdwait);
 1031         cv_destroy(&tp->t_outserwait);
 1032 
 1033         if (tp->t_mtx == &tp->t_mtxobj)
 1034                 mtx_destroy(&tp->t_mtxobj);
 1035         ttydevsw_free(tp);
 1036         free(tp, M_TTY);
 1037 }
 1038 
 1039 static void
 1040 tty_rel_free(struct tty *tp)
 1041 {
 1042         struct cdev *dev;
 1043 
 1044         tty_lock_assert(tp, MA_OWNED);
 1045 
 1046 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1047         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1048                 /* TTY is still in use. */
 1049                 tty_unlock(tp);
 1050                 return;
 1051         }
 1052 
 1053         /* TTY can be deallocated. */
 1054         dev = tp->t_dev;
 1055         tp->t_dev = NULL;
 1056         tty_unlock(tp);
 1057 
 1058         sx_xlock(&tty_list_sx);
 1059         TAILQ_REMOVE(&tty_list, tp, t_list);
 1060         tty_list_count--;
 1061         sx_xunlock(&tty_list_sx);
 1062 
 1063         if (dev != NULL)
 1064                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1065 }
 1066 
 1067 void
 1068 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1069 {
 1070         MPASS(tp->t_sessioncnt > 0);
 1071         tty_lock_assert(tp, MA_OWNED);
 1072 
 1073         if (tp->t_pgrp == pg)
 1074                 tp->t_pgrp = NULL;
 1075 
 1076         tty_unlock(tp);
 1077 }
 1078 
 1079 void
 1080 tty_rel_sess(struct tty *tp, struct session *sess)
 1081 {
 1082         MPASS(tp->t_sessioncnt > 0);
 1083 
 1084         /* Current session has left. */
 1085         if (tp->t_session == sess) {
 1086                 tp->t_session = NULL;
 1087                 MPASS(tp->t_pgrp == NULL);
 1088         }
 1089         tp->t_sessioncnt--;
 1090         tty_rel_free(tp);
 1091 }
 1092 
 1093 void
 1094 tty_rel_gone(struct tty *tp)
 1095 {
 1096         MPASS(!tty_gone(tp));
 1097 
 1098         /* Simulate carrier removal. */
 1099         ttydisc_modem(tp, 0);
 1100 
 1101         /* Wake up all blocked threads. */
 1102         tty_wakeup(tp, FREAD|FWRITE);
 1103         cv_broadcast(&tp->t_bgwait);
 1104         cv_broadcast(&tp->t_dcdwait);
 1105 
 1106         tp->t_flags |= TF_GONE;
 1107         tty_rel_free(tp);
 1108 }
 1109 
 1110 /*
 1111  * Exposing information about current TTY's through sysctl
 1112  */
 1113 
 1114 static void
 1115 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1116 {
 1117         tty_lock_assert(tp, MA_OWNED);
 1118 
 1119         xt->xt_size = sizeof(struct xtty);
 1120         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1121         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1122         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1123         xt->xt_inlow = tp->t_inlow;
 1124         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1125         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1126         xt->xt_outlow = tp->t_outlow;
 1127         xt->xt_column = tp->t_column;
 1128         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1129         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1130         xt->xt_flags = tp->t_flags;
 1131         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1132 }
 1133 
 1134 static int
 1135 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1136 {
 1137         unsigned long lsize;
 1138         struct xtty *xtlist, *xt;
 1139         struct tty *tp;
 1140         int error;
 1141 
 1142         sx_slock(&tty_list_sx);
 1143         lsize = tty_list_count * sizeof(struct xtty);
 1144         if (lsize == 0) {
 1145                 sx_sunlock(&tty_list_sx);
 1146                 return (0);
 1147         }
 1148 
 1149         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1150 
 1151         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1152                 tty_lock(tp);
 1153                 tty_to_xtty(tp, xt);
 1154                 tty_unlock(tp);
 1155                 xt++;
 1156         }
 1157         sx_sunlock(&tty_list_sx);
 1158 
 1159         error = SYSCTL_OUT(req, xtlist, lsize);
 1160         free(xtlist, M_TTY);
 1161         return (error);
 1162 }
 1163 
 1164 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1165         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1166 
 1167 /*
 1168  * Device node creation. Device has been set up, now we can expose it to
 1169  * the user.
 1170  */
 1171 
 1172 int
 1173 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
 1174     const char *fmt, ...)
 1175 {
 1176         va_list ap;
 1177         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
 1178         const char *prefix = "tty";
 1179         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1180         uid_t uid;
 1181         gid_t gid;
 1182         mode_t mode;
 1183         int error;
 1184 
 1185         /* Remove "tty" prefix from devices like PTY's. */
 1186         if (tp->t_flags & TF_NOPREFIX)
 1187                 prefix = "";
 1188 
 1189         va_start(ap, fmt);
 1190         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1191         va_end(ap);
 1192 
 1193         if (cred == NULL) {
 1194                 /* System device. */
 1195                 uid = UID_ROOT;
 1196                 gid = GID_WHEEL;
 1197                 mode = S_IRUSR|S_IWUSR;
 1198         } else {
 1199                 /* User device. */
 1200                 uid = cred->cr_ruid;
 1201                 gid = GID_TTY;
 1202                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1203         }
 1204 
 1205         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
 1206         flags |= MAKEDEV_CHECKNAME;
 1207 
 1208         /* Master call-in device. */
 1209         error = make_dev_p(flags, &dev, &ttydev_cdevsw, cred, uid, gid, mode,
 1210             "%s%s", prefix, name);
 1211         if (error)
 1212                 return (error);
 1213         dev->si_drv1 = tp;
 1214         wakeup(&dev->si_drv1);
 1215         tp->t_dev = dev;
 1216 
 1217         init = lock = cua = cinit = clock = NULL;
 1218 
 1219         /* Slave call-in devices. */
 1220         if (tp->t_flags & TF_INITLOCK) {
 1221                 error = make_dev_p(flags, &init, &ttyil_cdevsw, cred, uid,
 1222                     gid, mode, "%s%s.init", prefix, name);
 1223                 if (error)
 1224                         goto fail;
 1225                 dev_depends(dev, init);
 1226                 dev2unit(init) = TTYUNIT_INIT;
 1227                 init->si_drv1 = tp;
 1228                 wakeup(&init->si_drv1);
 1229                 init->si_drv2 = &tp->t_termios_init_in;
 1230 
 1231                 error = make_dev_p(flags, &lock, &ttyil_cdevsw, cred, uid,
 1232                     gid, mode, "%s%s.lock", prefix, name);
 1233                 if (error)
 1234                         goto fail;
 1235                 dev_depends(dev, lock);
 1236                 dev2unit(lock) = TTYUNIT_LOCK;
 1237                 lock->si_drv1 = tp;
 1238                 wakeup(&lock->si_drv1);
 1239                 lock->si_drv2 = &tp->t_termios_lock_in;
 1240         }
 1241 
 1242         /* Call-out devices. */
 1243         if (tp->t_flags & TF_CALLOUT) {
 1244                 error = make_dev_p(flags, &cua, &ttydev_cdevsw, cred,
 1245                     UID_UUCP, GID_DIALER, 0660, "cua%s", name);
 1246                 if (error)
 1247                         goto fail;
 1248                 dev_depends(dev, cua);
 1249                 dev2unit(cua) = TTYUNIT_CALLOUT;
 1250                 cua->si_drv1 = tp;
 1251                 wakeup(&cua->si_drv1);
 1252 
 1253                 /* Slave call-out devices. */
 1254                 if (tp->t_flags & TF_INITLOCK) {
 1255                         error = make_dev_p(flags, &cinit, &ttyil_cdevsw, cred,
 1256                             UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
 1257                         if (error)
 1258                                 goto fail;
 1259                         dev_depends(dev, cinit);
 1260                         dev2unit(cinit) = TTYUNIT_CALLOUT | TTYUNIT_INIT;
 1261                         cinit->si_drv1 = tp;
 1262                         wakeup(&cinit->si_drv1);
 1263                         cinit->si_drv2 = &tp->t_termios_init_out;
 1264 
 1265                         error = make_dev_p(flags, &clock, &ttyil_cdevsw, cred,
 1266                             UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
 1267                         if (error)
 1268                                 goto fail;
 1269                         dev_depends(dev, clock);
 1270                         dev2unit(clock) = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
 1271                         clock->si_drv1 = tp;
 1272                         wakeup(&clock->si_drv1);
 1273                         clock->si_drv2 = &tp->t_termios_lock_out;
 1274                 }
 1275         }
 1276 
 1277         sx_xlock(&tty_list_sx);
 1278         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
 1279         tty_list_count++;
 1280         sx_xunlock(&tty_list_sx);
 1281 
 1282         return (0);
 1283 
 1284 fail:
 1285         destroy_dev(dev);
 1286         if (init)
 1287                 destroy_dev(init);
 1288         if (lock)
 1289                 destroy_dev(lock);
 1290         if (cinit)
 1291                 destroy_dev(cinit);
 1292         if (clock)
 1293                 destroy_dev(clock);
 1294 
 1295         return (error);
 1296 }
 1297 
 1298 /*
 1299  * Signalling processes.
 1300  */
 1301 
 1302 void
 1303 tty_signal_sessleader(struct tty *tp, int sig)
 1304 {
 1305         struct proc *p;
 1306 
 1307         tty_lock_assert(tp, MA_OWNED);
 1308         MPASS(sig >= 1 && sig < NSIG);
 1309 
 1310         /* Make signals start output again. */
 1311         tp->t_flags &= ~TF_STOPPED;
 1312 
 1313         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1314                 p = tp->t_session->s_leader;
 1315                 PROC_LOCK(p);
 1316                 kern_psignal(p, sig);
 1317                 PROC_UNLOCK(p);
 1318         }
 1319 }
 1320 
 1321 void
 1322 tty_signal_pgrp(struct tty *tp, int sig)
 1323 {
 1324         ksiginfo_t ksi;
 1325 
 1326         tty_lock_assert(tp, MA_OWNED);
 1327         MPASS(sig >= 1 && sig < NSIG);
 1328 
 1329         /* Make signals start output again. */
 1330         tp->t_flags &= ~TF_STOPPED;
 1331 
 1332         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1333                 tty_info(tp);
 1334         if (tp->t_pgrp != NULL) {
 1335                 ksiginfo_init(&ksi);
 1336                 ksi.ksi_signo = sig;
 1337                 ksi.ksi_code = SI_KERNEL;
 1338                 PGRP_LOCK(tp->t_pgrp);
 1339                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1340                 PGRP_UNLOCK(tp->t_pgrp);
 1341         }
 1342 }
 1343 
 1344 void
 1345 tty_wakeup(struct tty *tp, int flags)
 1346 {
 1347         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1348                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1349 
 1350         if (flags & FWRITE) {
 1351                 cv_broadcast(&tp->t_outwait);
 1352                 selwakeup(&tp->t_outpoll);
 1353                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1354         }
 1355         if (flags & FREAD) {
 1356                 cv_broadcast(&tp->t_inwait);
 1357                 selwakeup(&tp->t_inpoll);
 1358                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1359         }
 1360 }
 1361 
 1362 int
 1363 tty_wait(struct tty *tp, struct cv *cv)
 1364 {
 1365         int error;
 1366         int revokecnt = tp->t_revokecnt;
 1367 
 1368         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1369         MPASS(!tty_gone(tp));
 1370 
 1371         error = cv_wait_sig(cv, tp->t_mtx);
 1372 
 1373         /* Restart the system call when we may have been revoked. */
 1374         if (tp->t_revokecnt != revokecnt)
 1375                 return (ERESTART);
 1376 
 1377         /* Bail out when the device slipped away. */
 1378         if (tty_gone(tp))
 1379                 return (ENXIO);
 1380 
 1381         return (error);
 1382 }
 1383 
 1384 int
 1385 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1386 {
 1387         int error;
 1388         int revokecnt = tp->t_revokecnt;
 1389 
 1390         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1391         MPASS(!tty_gone(tp));
 1392 
 1393         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1394 
 1395         /* Restart the system call when we may have been revoked. */
 1396         if (tp->t_revokecnt != revokecnt)
 1397                 return (ERESTART);
 1398 
 1399         /* Bail out when the device slipped away. */
 1400         if (tty_gone(tp))
 1401                 return (ENXIO);
 1402 
 1403         return (error);
 1404 }
 1405 
 1406 void
 1407 tty_flush(struct tty *tp, int flags)
 1408 {
 1409         if (flags & FWRITE) {
 1410                 tp->t_flags &= ~TF_HIWAT_OUT;
 1411                 ttyoutq_flush(&tp->t_outq);
 1412                 tty_wakeup(tp, FWRITE);
 1413                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1414         }
 1415         if (flags & FREAD) {
 1416                 tty_hiwat_in_unblock(tp);
 1417                 ttyinq_flush(&tp->t_inq);
 1418                 ttydevsw_inwakeup(tp);
 1419                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1420         }
 1421 }
 1422 
 1423 void
 1424 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
 1425 {
 1426 
 1427         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
 1428                 return;
 1429         tp->t_winsize = *wsz;
 1430         tty_signal_pgrp(tp, SIGWINCH);
 1431 }
 1432 
 1433 static int
 1434 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1435     struct thread *td)
 1436 {
 1437         int error;
 1438 
 1439         switch (cmd) {
 1440         /*
 1441          * Modem commands.
 1442          * The SER_* and TIOCM_* flags are the same, but one bit
 1443          * shifted. I don't know why.
 1444          */
 1445         case TIOCSDTR:
 1446                 ttydevsw_modem(tp, SER_DTR, 0);
 1447                 return (0);
 1448         case TIOCCDTR:
 1449                 ttydevsw_modem(tp, 0, SER_DTR);
 1450                 return (0);
 1451         case TIOCMSET: {
 1452                 int bits = *(int *)data;
 1453                 ttydevsw_modem(tp,
 1454                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1455                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1456                 return (0);
 1457         }
 1458         case TIOCMBIS: {
 1459                 int bits = *(int *)data;
 1460                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1461                 return (0);
 1462         }
 1463         case TIOCMBIC: {
 1464                 int bits = *(int *)data;
 1465                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1466                 return (0);
 1467         }
 1468         case TIOCMGET:
 1469                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1470                 return (0);
 1471 
 1472         case FIOASYNC:
 1473                 if (*(int *)data)
 1474                         tp->t_flags |= TF_ASYNC;
 1475                 else
 1476                         tp->t_flags &= ~TF_ASYNC;
 1477                 return (0);
 1478         case FIONBIO:
 1479                 /* This device supports non-blocking operation. */
 1480                 return (0);
 1481         case FIONREAD:
 1482                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1483                 return (0);
 1484         case FIONWRITE:
 1485         case TIOCOUTQ:
 1486                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1487                 return (0);
 1488         case FIOSETOWN:
 1489                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1490                         /* Not allowed to set ownership. */
 1491                         return (ENOTTY);
 1492 
 1493                 /* Temporarily unlock the TTY to set ownership. */
 1494                 tty_unlock(tp);
 1495                 error = fsetown(*(int *)data, &tp->t_sigio);
 1496                 tty_lock(tp);
 1497                 return (error);
 1498         case FIOGETOWN:
 1499                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1500                         /* Not allowed to set ownership. */
 1501                         return (ENOTTY);
 1502 
 1503                 /* Get ownership. */
 1504                 *(int *)data = fgetown(&tp->t_sigio);
 1505                 return (0);
 1506         case TIOCGETA:
 1507                 /* Obtain terminal flags through tcgetattr(). */
 1508                 *(struct termios*)data = tp->t_termios;
 1509                 return (0);
 1510         case TIOCSETA:
 1511         case TIOCSETAW:
 1512         case TIOCSETAF: {
 1513                 struct termios *t = data;
 1514 
 1515                 /*
 1516                  * Who makes up these funny rules? According to POSIX,
 1517                  * input baud rate is set equal to the output baud rate
 1518                  * when zero.
 1519                  */
 1520                 if (t->c_ispeed == 0)
 1521                         t->c_ispeed = t->c_ospeed;
 1522 
 1523                 /* Discard any unsupported bits. */
 1524                 t->c_iflag &= TTYSUP_IFLAG;
 1525                 t->c_oflag &= TTYSUP_OFLAG;
 1526                 t->c_lflag &= TTYSUP_LFLAG;
 1527                 t->c_cflag &= TTYSUP_CFLAG;
 1528 
 1529                 /* Set terminal flags through tcsetattr(). */
 1530                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1531                         error = tty_drain(tp);
 1532                         if (error)
 1533                                 return (error);
 1534                         if (cmd == TIOCSETAF)
 1535                                 tty_flush(tp, FREAD);
 1536                 }
 1537 
 1538                 /*
 1539                  * Only call param() when the flags really change.
 1540                  */
 1541                 if ((t->c_cflag & CIGNORE) == 0 &&
 1542                     (tp->t_termios.c_cflag != t->c_cflag ||
 1543                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
 1544                     (IXON|IXOFF|IXANY)) ||
 1545                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1546                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1547                         error = ttydevsw_param(tp, t);
 1548                         if (error)
 1549                                 return (error);
 1550 
 1551                         /* XXX: CLOCAL? */
 1552 
 1553                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1554                         tp->t_termios.c_ispeed = t->c_ispeed;
 1555                         tp->t_termios.c_ospeed = t->c_ospeed;
 1556 
 1557                         /* Baud rate has changed - update watermarks. */
 1558                         tty_watermarks(tp);
 1559                 }
 1560 
 1561                 /* Copy new non-device driver parameters. */
 1562                 tp->t_termios.c_iflag = t->c_iflag;
 1563                 tp->t_termios.c_oflag = t->c_oflag;
 1564                 tp->t_termios.c_lflag = t->c_lflag;
 1565                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1566 
 1567                 ttydisc_optimize(tp);
 1568 
 1569                 if ((t->c_lflag & ICANON) == 0) {
 1570                         /*
 1571                          * When in non-canonical mode, wake up all
 1572                          * readers. Canonicalize any partial input. VMIN
 1573                          * and VTIME could also be adjusted.
 1574                          */
 1575                         ttyinq_canonicalize(&tp->t_inq);
 1576                         tty_wakeup(tp, FREAD);
 1577                 }
 1578 
 1579                 /*
 1580                  * For packet mode: notify the PTY consumer that VSTOP
 1581                  * and VSTART may have been changed.
 1582                  */
 1583                 if (tp->t_termios.c_iflag & IXON &&
 1584                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1585                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1586                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1587                 else
 1588                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1589                 return (0);
 1590         }
 1591         case TIOCGETD:
 1592                 /* For compatibility - we only support TTYDISC. */
 1593                 *(int *)data = TTYDISC;
 1594                 return (0);
 1595         case TIOCGPGRP:
 1596                 if (!tty_is_ctty(tp, td->td_proc))
 1597                         return (ENOTTY);
 1598 
 1599                 if (tp->t_pgrp != NULL)
 1600                         *(int *)data = tp->t_pgrp->pg_id;
 1601                 else
 1602                         *(int *)data = NO_PID;
 1603                 return (0);
 1604         case TIOCGSID:
 1605                 if (!tty_is_ctty(tp, td->td_proc))
 1606                         return (ENOTTY);
 1607 
 1608                 MPASS(tp->t_session);
 1609                 *(int *)data = tp->t_session->s_sid;
 1610                 return (0);
 1611         case TIOCSCTTY: {
 1612                 struct proc *p = td->td_proc;
 1613 
 1614                 /* XXX: This looks awful. */
 1615                 tty_unlock(tp);
 1616                 sx_xlock(&proctree_lock);
 1617                 tty_lock(tp);
 1618 
 1619                 if (!SESS_LEADER(p)) {
 1620                         /* Only the session leader may do this. */
 1621                         sx_xunlock(&proctree_lock);
 1622                         return (EPERM);
 1623                 }
 1624 
 1625                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1626                         /* This is already our controlling TTY. */
 1627                         sx_xunlock(&proctree_lock);
 1628                         return (0);
 1629                 }
 1630 
 1631                 if (p->p_session->s_ttyp != NULL ||
 1632                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1633                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1634                         /*
 1635                          * There is already a relation between a TTY and
 1636                          * a session, or the caller is not the session
 1637                          * leader.
 1638                          *
 1639                          * Allow the TTY to be stolen when the vnode is
 1640                          * invalid, but the reference to the TTY is
 1641                          * still active.  This allows immediate reuse of
 1642                          * TTYs of which the session leader has been
 1643                          * killed or the TTY revoked.
 1644                          */
 1645                         sx_xunlock(&proctree_lock);
 1646                         return (EPERM);
 1647                 }
 1648 
 1649                 /* Connect the session to the TTY. */
 1650                 tp->t_session = p->p_session;
 1651                 tp->t_session->s_ttyp = tp;
 1652                 tp->t_sessioncnt++;
 1653                 sx_xunlock(&proctree_lock);
 1654 
 1655                 /* Assign foreground process group. */
 1656                 tp->t_pgrp = p->p_pgrp;
 1657                 PROC_LOCK(p);
 1658                 p->p_flag |= P_CONTROLT;
 1659                 PROC_UNLOCK(p);
 1660 
 1661                 return (0);
 1662         }
 1663         case TIOCSPGRP: {
 1664                 struct pgrp *pg;
 1665 
 1666                 /*
 1667                  * XXX: Temporarily unlock the TTY to locate the process
 1668                  * group. This code would be lot nicer if we would ever
 1669                  * decompose proctree_lock.
 1670                  */
 1671                 tty_unlock(tp);
 1672                 sx_slock(&proctree_lock);
 1673                 pg = pgfind(*(int *)data);
 1674                 if (pg != NULL)
 1675                         PGRP_UNLOCK(pg);
 1676                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1677                         sx_sunlock(&proctree_lock);
 1678                         tty_lock(tp);
 1679                         return (EPERM);
 1680                 }
 1681                 tty_lock(tp);
 1682 
 1683                 /*
 1684                  * Determine if this TTY is the controlling TTY after
 1685                  * relocking the TTY.
 1686                  */
 1687                 if (!tty_is_ctty(tp, td->td_proc)) {
 1688                         sx_sunlock(&proctree_lock);
 1689                         return (ENOTTY);
 1690                 }
 1691                 tp->t_pgrp = pg;
 1692                 sx_sunlock(&proctree_lock);
 1693 
 1694                 /* Wake up the background process groups. */
 1695                 cv_broadcast(&tp->t_bgwait);
 1696                 return (0);
 1697         }
 1698         case TIOCFLUSH: {
 1699                 int flags = *(int *)data;
 1700 
 1701                 if (flags == 0)
 1702                         flags = (FREAD|FWRITE);
 1703                 else
 1704                         flags &= (FREAD|FWRITE);
 1705                 tty_flush(tp, flags);
 1706                 return (0);
 1707         }
 1708         case TIOCDRAIN:
 1709                 /* Drain TTY output. */
 1710                 return tty_drain(tp);
 1711         case TIOCCONS:
 1712                 /* Set terminal as console TTY. */
 1713                 if (*(int *)data) {
 1714                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1715                         if (error)
 1716                                 return (error);
 1717 
 1718                         /*
 1719                          * XXX: constty should really need to be locked!
 1720                          * XXX: allow disconnected constty's to be stolen!
 1721                          */
 1722 
 1723                         if (constty == tp)
 1724                                 return (0);
 1725                         if (constty != NULL)
 1726                                 return (EBUSY);
 1727 
 1728                         tty_unlock(tp);
 1729                         constty_set(tp);
 1730                         tty_lock(tp);
 1731                 } else if (constty == tp) {
 1732                         constty_clear();
 1733                 }
 1734                 return (0);
 1735         case TIOCGWINSZ:
 1736                 /* Obtain window size. */
 1737                 *(struct winsize*)data = tp->t_winsize;
 1738                 return (0);
 1739         case TIOCSWINSZ:
 1740                 /* Set window size. */
 1741                 tty_set_winsize(tp, data);
 1742                 return (0);
 1743         case TIOCEXCL:
 1744                 tp->t_flags |= TF_EXCLUDE;
 1745                 return (0);
 1746         case TIOCNXCL:
 1747                 tp->t_flags &= ~TF_EXCLUDE;
 1748                 return (0);
 1749         case TIOCSTOP:
 1750                 tp->t_flags |= TF_STOPPED;
 1751                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1752                 return (0);
 1753         case TIOCSTART:
 1754                 tp->t_flags &= ~TF_STOPPED;
 1755                 ttydevsw_outwakeup(tp);
 1756                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1757                 return (0);
 1758         case TIOCSTAT:
 1759                 tty_info(tp);
 1760                 return (0);
 1761         case TIOCSTI:
 1762                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1763                         return (EPERM);
 1764                 if (!tty_is_ctty(tp, td->td_proc) &&
 1765                     priv_check(td, PRIV_TTY_STI))
 1766                         return (EACCES);
 1767                 ttydisc_rint(tp, *(char *)data, 0);
 1768                 ttydisc_rint_done(tp);
 1769                 return (0);
 1770         }
 1771 
 1772 #ifdef COMPAT_43TTY
 1773         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1774 #else /* !COMPAT_43TTY */
 1775         return (ENOIOCTL);
 1776 #endif /* COMPAT_43TTY */
 1777 }
 1778 
 1779 int
 1780 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1781 {
 1782         int error;
 1783 
 1784         tty_lock_assert(tp, MA_OWNED);
 1785 
 1786         if (tty_gone(tp))
 1787                 return (ENXIO);
 1788 
 1789         error = ttydevsw_ioctl(tp, cmd, data, td);
 1790         if (error == ENOIOCTL)
 1791                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1792 
 1793         return (error);
 1794 }
 1795 
 1796 dev_t
 1797 tty_udev(struct tty *tp)
 1798 {
 1799         if (tp->t_dev)
 1800                 return dev2udev(tp->t_dev);
 1801         else
 1802                 return NODEV;
 1803 }
 1804 
 1805 int
 1806 tty_checkoutq(struct tty *tp)
 1807 {
 1808 
 1809         /* 256 bytes should be enough to print a log message. */
 1810         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1811 }
 1812 
 1813 void
 1814 tty_hiwat_in_block(struct tty *tp)
 1815 {
 1816 
 1817         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1818             tp->t_termios.c_iflag & IXOFF &&
 1819             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1820                 /*
 1821                  * Input flow control. Only enter the high watermark when we
 1822                  * can successfully store the VSTOP character.
 1823                  */
 1824                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1825                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1826                         tp->t_flags |= TF_HIWAT_IN;
 1827         } else {
 1828                 /* No input flow control. */
 1829                 tp->t_flags |= TF_HIWAT_IN;
 1830         }
 1831 }
 1832 
 1833 void
 1834 tty_hiwat_in_unblock(struct tty *tp)
 1835 {
 1836 
 1837         if (tp->t_flags & TF_HIWAT_IN &&
 1838             tp->t_termios.c_iflag & IXOFF &&
 1839             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1840                 /*
 1841                  * Input flow control. Only leave the high watermark when we
 1842                  * can successfully store the VSTART character.
 1843                  */
 1844                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1845                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1846                         tp->t_flags &= ~TF_HIWAT_IN;
 1847         } else {
 1848                 /* No input flow control. */
 1849                 tp->t_flags &= ~TF_HIWAT_IN;
 1850         }
 1851 
 1852         if (!tty_gone(tp))
 1853                 ttydevsw_inwakeup(tp);
 1854 }
 1855 
 1856 /*
 1857  * TTY hooks interface.
 1858  */
 1859 
 1860 static int
 1861 ttyhook_defrint(struct tty *tp, char c, int flags)
 1862 {
 1863 
 1864         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1865                 return (-1);
 1866 
 1867         return (0);
 1868 }
 1869 
 1870 int
 1871 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
 1872     struct ttyhook *th, void *softc)
 1873 {
 1874         struct tty *tp;
 1875         struct file *fp;
 1876         struct cdev *dev;
 1877         struct cdevsw *cdp;
 1878         struct filedesc *fdp;
 1879         cap_rights_t rights;
 1880         int error, ref;
 1881 
 1882         /* Validate the file descriptor. */
 1883         fdp = p->p_fd;
 1884         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
 1885             0, &fp, NULL);
 1886         if (error != 0)
 1887                 return (error);
 1888         if (fp->f_ops == &badfileops) {
 1889                 error = EBADF;
 1890                 goto done1;
 1891         }
 1892 
 1893         /*
 1894          * Make sure the vnode is bound to a character device.
 1895          * Unlocked check for the vnode type is ok there, because we
 1896          * only shall prevent calling devvn_refthread on the file that
 1897          * never has been opened over a character device.
 1898          */
 1899         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1900                 error = EINVAL;
 1901                 goto done1;
 1902         }
 1903 
 1904         /* Make sure it is a TTY. */
 1905         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
 1906         if (cdp == NULL) {
 1907                 error = ENXIO;
 1908                 goto done1;
 1909         }
 1910         if (dev != fp->f_data) {
 1911                 error = ENXIO;
 1912                 goto done2;
 1913         }
 1914         if (cdp != &ttydev_cdevsw) {
 1915                 error = ENOTTY;
 1916                 goto done2;
 1917         }
 1918         tp = dev->si_drv1;
 1919 
 1920         /* Try to attach the hook to the TTY. */
 1921         error = EBUSY;
 1922         tty_lock(tp);
 1923         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1924         if (tp->t_flags & TF_HOOK)
 1925                 goto done3;
 1926 
 1927         tp->t_flags |= TF_HOOK;
 1928         tp->t_hook = th;
 1929         tp->t_hooksoftc = softc;
 1930         *rtp = tp;
 1931         error = 0;
 1932 
 1933         /* Maybe we can switch into bypass mode now. */
 1934         ttydisc_optimize(tp);
 1935 
 1936         /* Silently convert rint() calls to rint_bypass() when possible. */
 1937         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 1938                 th->th_rint = ttyhook_defrint;
 1939 
 1940 done3:  tty_unlock(tp);
 1941 done2:  dev_relthread(dev, ref);
 1942 done1:  fdrop(fp, curthread);
 1943         return (error);
 1944 }
 1945 
 1946 void
 1947 ttyhook_unregister(struct tty *tp)
 1948 {
 1949 
 1950         tty_lock_assert(tp, MA_OWNED);
 1951         MPASS(tp->t_flags & TF_HOOK);
 1952 
 1953         /* Disconnect the hook. */
 1954         tp->t_flags &= ~TF_HOOK;
 1955         tp->t_hook = NULL;
 1956 
 1957         /* Maybe we need to leave bypass mode. */
 1958         ttydisc_optimize(tp);
 1959 
 1960         /* Maybe deallocate the TTY as well. */
 1961         tty_rel_free(tp);
 1962 }
 1963 
 1964 /*
 1965  * /dev/console handling.
 1966  */
 1967 
 1968 static int
 1969 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 1970 {
 1971         struct tty *tp;
 1972 
 1973         /* System has no console device. */
 1974         if (dev_console_filename == NULL)
 1975                 return (ENXIO);
 1976 
 1977         /* Look up corresponding TTY by device name. */
 1978         sx_slock(&tty_list_sx);
 1979         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1980                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 1981                         dev_console->si_drv1 = tp;
 1982                         break;
 1983                 }
 1984         }
 1985         sx_sunlock(&tty_list_sx);
 1986 
 1987         /* System console has no TTY associated. */
 1988         if (dev_console->si_drv1 == NULL)
 1989                 return (ENXIO);
 1990 
 1991         return (ttydev_open(dev, oflags, devtype, td));
 1992 }
 1993 
 1994 static int
 1995 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 1996 {
 1997 
 1998         log_console(uio);
 1999 
 2000         return (ttydev_write(dev, uio, ioflag));
 2001 }
 2002 
 2003 /*
 2004  * /dev/console is a little different than normal TTY's.  When opened,
 2005  * it determines which TTY to use.  When data gets written to it, it
 2006  * will be logged in the kernel message buffer.
 2007  */
 2008 static struct cdevsw ttyconsdev_cdevsw = {
 2009         .d_version      = D_VERSION,
 2010         .d_open         = ttyconsdev_open,
 2011         .d_close        = ttydev_close,
 2012         .d_read         = ttydev_read,
 2013         .d_write        = ttyconsdev_write,
 2014         .d_ioctl        = ttydev_ioctl,
 2015         .d_kqfilter     = ttydev_kqfilter,
 2016         .d_poll         = ttydev_poll,
 2017         .d_mmap         = ttydev_mmap,
 2018         .d_name         = "ttyconsdev",
 2019         .d_flags        = D_TTY,
 2020 };
 2021 
 2022 static void
 2023 ttyconsdev_init(void *unused)
 2024 {
 2025 
 2026         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
 2027             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
 2028 }
 2029 
 2030 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 2031 
 2032 void
 2033 ttyconsdev_select(const char *name)
 2034 {
 2035 
 2036         dev_console_filename = name;
 2037 }
 2038 
 2039 /*
 2040  * Debugging routines.
 2041  */
 2042 
 2043 #include "opt_ddb.h"
 2044 #ifdef DDB
 2045 #include <ddb/ddb.h>
 2046 #include <ddb/db_sym.h>
 2047 
 2048 static struct {
 2049         int flag;
 2050         char val;
 2051 } ttystates[] = {
 2052 #if 0
 2053         { TF_NOPREFIX,          'N' },
 2054 #endif
 2055         { TF_INITLOCK,          'I' },
 2056         { TF_CALLOUT,           'C' },
 2057 
 2058         /* Keep these together -> 'Oi' and 'Oo'. */
 2059         { TF_OPENED,            'O' },
 2060         { TF_OPENED_IN,         'i' },
 2061         { TF_OPENED_OUT,        'o' },
 2062         { TF_OPENED_CONS,       'c' },
 2063 
 2064         { TF_GONE,              'G' },
 2065         { TF_OPENCLOSE,         'B' },
 2066         { TF_ASYNC,             'Y' },
 2067         { TF_LITERAL,           'L' },
 2068 
 2069         /* Keep these together -> 'Hi' and 'Ho'. */
 2070         { TF_HIWAT,             'H' },
 2071         { TF_HIWAT_IN,          'i' },
 2072         { TF_HIWAT_OUT,         'o' },
 2073 
 2074         { TF_STOPPED,           'S' },
 2075         { TF_EXCLUDE,           'X' },
 2076         { TF_BYPASS,            'l' },
 2077         { TF_ZOMBIE,            'Z' },
 2078         { TF_HOOK,              's' },
 2079 
 2080         /* Keep these together -> 'bi' and 'bo'. */
 2081         { TF_BUSY,              'b' },
 2082         { TF_BUSY_IN,           'i' },
 2083         { TF_BUSY_OUT,          'o' },
 2084 
 2085         { 0,                    '\0'},
 2086 };
 2087 
 2088 #define TTY_FLAG_BITS \
 2089         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
 2090         "\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
 2091         "\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
 2092 
 2093 #define DB_PRINTSYM(name, addr) \
 2094         db_printf("%s  " #name ": ", sep); \
 2095         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 2096         db_printf("\n");
 2097 
 2098 static void
 2099 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2100 {
 2101         db_printf("%sdevsw: ", sep);
 2102         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2103         db_printf(" (%p)\n", tsw);
 2104         DB_PRINTSYM(open, tsw->tsw_open);
 2105         DB_PRINTSYM(close, tsw->tsw_close);
 2106         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2107         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2108         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2109         DB_PRINTSYM(param, tsw->tsw_param);
 2110         DB_PRINTSYM(modem, tsw->tsw_modem);
 2111         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2112         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2113         DB_PRINTSYM(free, tsw->tsw_free);
 2114 }
 2115 static void
 2116 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2117 {
 2118         db_printf("%shook: ", sep);
 2119         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2120         db_printf(" (%p)\n", th);
 2121         if (th == NULL)
 2122                 return;
 2123         DB_PRINTSYM(rint, th->th_rint);
 2124         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2125         DB_PRINTSYM(rint_done, th->th_rint_done);
 2126         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2127         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2128         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2129         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2130         DB_PRINTSYM(close, th->th_close);
 2131 }
 2132 
 2133 static void
 2134 _db_show_termios(const char *name, const struct termios *t)
 2135 {
 2136 
 2137         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2138             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2139             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2140             t->c_ispeed, t->c_ospeed);
 2141 }
 2142 
 2143 /* DDB command to show TTY statistics. */
 2144 DB_SHOW_COMMAND(tty, db_show_tty)
 2145 {
 2146         struct tty *tp;
 2147 
 2148         if (!have_addr) {
 2149                 db_printf("usage: show tty <addr>\n");
 2150                 return;
 2151         }
 2152         tp = (struct tty *)addr;
 2153 
 2154         db_printf("0x%p: %s\n", tp, tty_devname(tp));
 2155         db_printf("\tmtx: %p\n", tp->t_mtx);
 2156         db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
 2157         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2158 
 2159         /* Buffering mechanisms. */
 2160         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2161             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2162             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2163             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2164         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2165             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2166             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2167         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2168         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2169         _db_show_termios("\ttermios", &tp->t_termios);
 2170         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2171             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2172             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2173         db_printf("\tcolumn: %u\n", tp->t_column);
 2174         db_printf("\twritepos: %u\n", tp->t_writepos);
 2175         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2176 
 2177         /* Init/lock-state devices. */
 2178         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2179         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2180         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2181         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2182 
 2183         /* Hooks */
 2184         _db_show_devsw("\t", tp->t_devsw);
 2185         _db_show_hooks("\t", tp->t_hook);
 2186 
 2187         /* Process info. */
 2188         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2189             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2190             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2191         db_printf("\tsession: %p", tp->t_session);
 2192         if (tp->t_session != NULL)
 2193             db_printf(" count %u leader %p tty %p sid %d login %s",
 2194                 tp->t_session->s_count, tp->t_session->s_leader,
 2195                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2196                 tp->t_session->s_login);
 2197         db_printf("\n");
 2198         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2199         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2200         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2201         db_printf("\tdev: %p\n", tp->t_dev);
 2202 }
 2203 
 2204 /* DDB command to list TTYs. */
 2205 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2206 {
 2207         struct tty *tp;
 2208         size_t isiz, osiz;
 2209         int i, j;
 2210 
 2211         /* Make the output look like `pstat -t'. */
 2212         db_printf("PTR        ");
 2213 #if defined(__LP64__)
 2214         db_printf("        ");
 2215 #endif
 2216         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2217             "COL  SESS  PGID STATE\n");
 2218 
 2219         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2220                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2221                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2222 
 2223                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
 2224                     tp,
 2225                     tty_devname(tp),
 2226                     isiz,
 2227                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2228                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2229                     isiz - tp->t_inlow,
 2230                     osiz,
 2231                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2232                     osiz - tp->t_outlow,
 2233                     MIN(tp->t_column, 99999),
 2234                     tp->t_session ? tp->t_session->s_sid : 0,
 2235                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2236 
 2237                 /* Flag bits. */
 2238                 for (i = j = 0; ttystates[i].flag; i++)
 2239                         if (tp->t_flags & ttystates[i].flag) {
 2240                                 db_printf("%c", ttystates[i].val);
 2241                                 j++;
 2242                         }
 2243                 if (j == 0)
 2244                         db_printf("-");
 2245                 db_printf("\n");
 2246         }
 2247 }
 2248 #endif /* DDB */

Cache object: e019c436d880a3b61d12a614637e11fb


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