tty.c

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    1 /*-
    2  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
    3  * All rights reserved.
    4  *
    5  * Portions of this software were developed under sponsorship from Snow
    6  * B.V., the Netherlands.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD: releng/9.1/sys/kern/tty.c 240239 2012-09-08 16:45:48Z kib $");
   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 ouput 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                 tty_drain(tp);
  196 
  197         ttydisc_close(tp);
  198 
  199         /* Destroy associated buffers already. */
  200         ttyinq_free(&tp->t_inq);
  201         tp->t_inlow = 0;
  202         ttyoutq_free(&tp->t_outq);
  203         tp->t_outlow = 0;
  204 
  205         knlist_clear(&tp->t_inpoll.si_note, 1);
  206         knlist_clear(&tp->t_outpoll.si_note, 1);
  207 
  208         if (!tty_gone(tp))
  209                 ttydevsw_close(tp);
  210 
  211         tp->t_flags &= ~TF_OPENCLOSE;
  212         cv_broadcast(&tp->t_dcdwait);
  213         tty_rel_free(tp);
  214 }
  215 
  216 /*
  217  * Operations that are exposed through the character device in /dev.
  218  */
  219 static int
  220 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  221 {
  222         struct tty *tp;
  223         int error = 0;
  224 
  225         while ((tp = dev->si_drv1) == NULL) {
  226                 error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
  227                 if (error != EWOULDBLOCK)
  228                         return (error);
  229         }
  230 
  231         tty_lock(tp);
  232         if (tty_gone(tp)) {
  233                 /* Device is already gone. */
  234                 tty_unlock(tp);
  235                 return (ENXIO);
  236         }
  237 
  238         /*
  239          * Block when other processes are currently opening or closing
  240          * the TTY.
  241          */
  242         while (tp->t_flags & TF_OPENCLOSE) {
  243                 error = tty_wait(tp, &tp->t_dcdwait);
  244                 if (error != 0) {
  245                         tty_unlock(tp);
  246                         return (error);
  247                 }
  248         }
  249         tp->t_flags |= TF_OPENCLOSE;
  250 
  251         /*
  252          * Make sure the "tty" and "cua" device cannot be opened at the
  253          * same time.
  254          */
  255         if (TTY_CALLOUT(tp, dev)) {
  256                 if (tp->t_flags & TF_OPENED_IN) {
  257                         error = EBUSY;
  258                         goto done;
  259                 }
  260         } else {
  261                 if (tp->t_flags & TF_OPENED_OUT) {
  262                         error = EBUSY;
  263                         goto done;
  264                 }
  265         }
  266 
  267         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
  268                 error = EBUSY;
  269                 goto done;
  270         }
  271 
  272         if (!tty_opened(tp)) {
  273                 /* Set proper termios flags. */
  274                 if (TTY_CALLOUT(tp, dev))
  275                         tp->t_termios = tp->t_termios_init_out;
  276                 else
  277                         tp->t_termios = tp->t_termios_init_in;
  278                 ttydevsw_param(tp, &tp->t_termios);
  279                 /* Prevent modem control on callout devices and /dev/console. */
  280                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
  281                         tp->t_termios.c_cflag |= CLOCAL;
  282 
  283                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
  284 
  285                 error = ttydevsw_open(tp);
  286                 if (error != 0)
  287                         goto done;
  288 
  289                 ttydisc_open(tp);
  290                 tty_watermarks(tp);
  291         }
  292 
  293         /* Wait for Carrier Detect. */
  294         if ((oflags & O_NONBLOCK) == 0 &&
  295             (tp->t_termios.c_cflag & CLOCAL) == 0) {
  296                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
  297                         error = tty_wait(tp, &tp->t_dcdwait);
  298                         if (error != 0)
  299                                 goto done;
  300                 }
  301         }
  302 
  303         if (dev == dev_console)
  304                 tp->t_flags |= TF_OPENED_CONS;
  305         else if (TTY_CALLOUT(tp, dev))
  306                 tp->t_flags |= TF_OPENED_OUT;
  307         else
  308                 tp->t_flags |= TF_OPENED_IN;
  309 
  310 done:   tp->t_flags &= ~TF_OPENCLOSE;
  311         cv_broadcast(&tp->t_dcdwait);
  312         ttydev_leave(tp);
  313 
  314         return (error);
  315 }
  316 
  317 static int
  318 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
  319 {
  320         struct tty *tp = dev->si_drv1;
  321 
  322         tty_lock(tp);
  323 
  324         /*
  325          * Don't actually close the device if it is being used as the
  326          * console.
  327          */
  328         MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
  329         if (dev == dev_console)
  330                 tp->t_flags &= ~TF_OPENED_CONS;
  331         else
  332                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
  333 
  334         if (tp->t_flags & TF_OPENED) {
  335                 tty_unlock(tp);
  336                 return (0);
  337         }
  338 
  339         /*
  340          * This can only be called once. The callin and the callout
  341          * devices cannot be opened at the same time.
  342          */
  343         tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
  344 
  345         /* Properly wake up threads that are stuck - revoke(). */
  346         tp->t_revokecnt++;
  347         tty_wakeup(tp, FREAD|FWRITE);
  348         cv_broadcast(&tp->t_bgwait);
  349         cv_broadcast(&tp->t_dcdwait);
  350 
  351         ttydev_leave(tp);
  352 
  353         return (0);
  354 }
  355 
  356 static __inline int
  357 tty_is_ctty(struct tty *tp, struct proc *p)
  358 {
  359         tty_lock_assert(tp, MA_OWNED);
  360 
  361         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
  362 }
  363 
  364 static int
  365 tty_wait_background(struct tty *tp, struct thread *td, int sig)
  366 {
  367         struct proc *p = td->td_proc;
  368         struct pgrp *pg;
  369         ksiginfo_t ksi;
  370         int error;
  371 
  372         MPASS(sig == SIGTTIN || sig == SIGTTOU);
  373         tty_lock_assert(tp, MA_OWNED);
  374 
  375         for (;;) {
  376                 PROC_LOCK(p);
  377                 /*
  378                  * The process should only sleep, when:
  379                  * - This terminal is the controling terminal
  380                  * - Its process group is not the foreground process
  381                  *   group
  382                  * - The parent process isn't waiting for the child to
  383                  *   exit
  384                  * - the signal to send to the process isn't masked
  385                  */
  386                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
  387                         /* Allow the action to happen. */
  388                         PROC_UNLOCK(p);
  389                         return (0);
  390                 }
  391 
  392                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
  393                     SIGISMEMBER(td->td_sigmask, sig)) {
  394                         /* Only allow them in write()/ioctl(). */
  395                         PROC_UNLOCK(p);
  396                         return (sig == SIGTTOU ? 0 : EIO);
  397                 }
  398 
  399                 pg = p->p_pgrp;
  400                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
  401                         /* Don't allow the action to happen. */
  402                         PROC_UNLOCK(p);
  403                         return (EIO);
  404                 }
  405                 PROC_UNLOCK(p);
  406 
  407                 /*
  408                  * Send the signal and sleep until we're the new
  409                  * foreground process group.
  410                  */
  411                 if (sig != 0) {
  412                         ksiginfo_init(&ksi);
  413                         ksi.ksi_code = SI_KERNEL;
  414                         ksi.ksi_signo = sig;
  415                         sig = 0;
  416                 }
  417                 PGRP_LOCK(pg);
  418                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
  419                 PGRP_UNLOCK(pg);
  420 
  421                 error = tty_wait(tp, &tp->t_bgwait);
  422                 if (error)
  423                         return (error);
  424         }
  425 }
  426 
  427 static int
  428 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
  429 {
  430         struct tty *tp = dev->si_drv1;
  431         int error;
  432 
  433         error = ttydev_enter(tp);
  434         if (error)
  435                 goto done;
  436 
  437         error = tty_wait_background(tp, curthread, SIGTTIN);
  438         if (error) {
  439                 tty_unlock(tp);
  440                 goto done;
  441         }
  442 
  443         error = ttydisc_read(tp, uio, ioflag);
  444         tty_unlock(tp);
  445 
  446         /*
  447          * The read() call should not throw an error when the device is
  448          * being destroyed. Silently convert it to an EOF.
  449          */
  450 done:   if (error == ENXIO)
  451                 error = 0;
  452         return (error);
  453 }
  454 
  455 static int
  456 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  457 {
  458         struct tty *tp = dev->si_drv1;
  459         int error;
  460 
  461         error = ttydev_enter(tp);
  462         if (error)
  463                 return (error);
  464 
  465         if (tp->t_termios.c_lflag & TOSTOP) {
  466                 error = tty_wait_background(tp, curthread, SIGTTOU);
  467                 if (error)
  468                         goto done;
  469         }
  470 
  471         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  472                 /* Allow non-blocking writes to bypass serialization. */
  473                 error = ttydisc_write(tp, uio, ioflag);
  474         } else {
  475                 /* Serialize write() calls. */
  476                 while (tp->t_flags & TF_BUSY_OUT) {
  477                         error = tty_wait(tp, &tp->t_outserwait);
  478                         if (error)
  479                                 goto done;
  480                 }
  481 
  482                 tp->t_flags |= TF_BUSY_OUT;
  483                 error = ttydisc_write(tp, uio, ioflag);
  484                 tp->t_flags &= ~TF_BUSY_OUT;
  485                 cv_signal(&tp->t_outserwait);
  486         }
  487 
  488 done:   tty_unlock(tp);
  489         return (error);
  490 }
  491 
  492 static int
  493 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  494     struct thread *td)
  495 {
  496         struct tty *tp = dev->si_drv1;
  497         int error;
  498 
  499         error = ttydev_enter(tp);
  500         if (error)
  501                 return (error);
  502 
  503         switch (cmd) {
  504         case TIOCCBRK:
  505         case TIOCCONS:
  506         case TIOCDRAIN:
  507         case TIOCEXCL:
  508         case TIOCFLUSH:
  509         case TIOCNXCL:
  510         case TIOCSBRK:
  511         case TIOCSCTTY:
  512         case TIOCSETA:
  513         case TIOCSETAF:
  514         case TIOCSETAW:
  515         case TIOCSPGRP:
  516         case TIOCSTART:
  517         case TIOCSTAT:
  518         case TIOCSTI:
  519         case TIOCSTOP:
  520         case TIOCSWINSZ:
  521 #if 0
  522         case TIOCSDRAINWAIT:
  523         case TIOCSETD:
  524 #endif
  525 #ifdef COMPAT_43TTY
  526         case  TIOCLBIC:
  527         case  TIOCLBIS:
  528         case  TIOCLSET:
  529         case  TIOCSETC:
  530         case OTIOCSETD:
  531         case  TIOCSETN:
  532         case  TIOCSETP:
  533         case  TIOCSLTC:
  534 #endif /* COMPAT_43TTY */
  535                 /*
  536                  * If the ioctl() causes the TTY to be modified, let it
  537                  * wait in the background.
  538                  */
  539                 error = tty_wait_background(tp, curthread, SIGTTOU);
  540                 if (error)
  541                         goto done;
  542         }
  543 
  544         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  545                 struct termios *old = &tp->t_termios;
  546                 struct termios *new = (struct termios *)data;
  547                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  548                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  549                 int cc;
  550 
  551                 /*
  552                  * Lock state devices.  Just overwrite the values of the
  553                  * commands that are currently in use.
  554                  */
  555                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  556                     (new->c_iflag & ~lock->c_iflag);
  557                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  558                     (new->c_oflag & ~lock->c_oflag);
  559                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  560                     (new->c_cflag & ~lock->c_cflag);
  561                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  562                     (new->c_lflag & ~lock->c_lflag);
  563                 for (cc = 0; cc < NCCS; ++cc)
  564                         if (lock->c_cc[cc])
  565                                 new->c_cc[cc] = old->c_cc[cc];
  566                 if (lock->c_ispeed)
  567                         new->c_ispeed = old->c_ispeed;
  568                 if (lock->c_ospeed)
  569                         new->c_ospeed = old->c_ospeed;
  570         }
  571 
  572         error = tty_ioctl(tp, cmd, data, fflag, td);
  573 done:   tty_unlock(tp);
  574 
  575         return (error);
  576 }
  577 
  578 static int
  579 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  580 {
  581         struct tty *tp = dev->si_drv1;
  582         int error, revents = 0;
  583 
  584         error = ttydev_enter(tp);
  585         if (error)
  586                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  587 
  588         if (events & (POLLIN|POLLRDNORM)) {
  589                 /* See if we can read something. */
  590                 if (ttydisc_read_poll(tp) > 0)
  591                         revents |= events & (POLLIN|POLLRDNORM);
  592         }
  593 
  594         if (tp->t_flags & TF_ZOMBIE) {
  595                 /* Hangup flag on zombie state. */
  596                 revents |= POLLHUP;
  597         } else if (events & (POLLOUT|POLLWRNORM)) {
  598                 /* See if we can write something. */
  599                 if (ttydisc_write_poll(tp) > 0)
  600                         revents |= events & (POLLOUT|POLLWRNORM);
  601         }
  602 
  603         if (revents == 0) {
  604                 if (events & (POLLIN|POLLRDNORM))
  605                         selrecord(td, &tp->t_inpoll);
  606                 if (events & (POLLOUT|POLLWRNORM))
  607                         selrecord(td, &tp->t_outpoll);
  608         }
  609 
  610         tty_unlock(tp);
  611 
  612         return (revents);
  613 }
  614 
  615 static int
  616 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  617     int nprot, vm_memattr_t *memattr)
  618 {
  619         struct tty *tp = dev->si_drv1;
  620         int error;
  621 
  622         /* Handle mmap() through the driver. */
  623 
  624         error = ttydev_enter(tp);
  625         if (error)
  626                 return (-1);
  627         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
  628         tty_unlock(tp);
  629 
  630         return (error);
  631 }
  632 
  633 /*
  634  * kqueue support.
  635  */
  636 
  637 static void
  638 tty_kqops_read_detach(struct knote *kn)
  639 {
  640         struct tty *tp = kn->kn_hook;
  641 
  642         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  643 }
  644 
  645 static int
  646 tty_kqops_read_event(struct knote *kn, long hint)
  647 {
  648         struct tty *tp = kn->kn_hook;
  649 
  650         tty_lock_assert(tp, MA_OWNED);
  651 
  652         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  653                 kn->kn_flags |= EV_EOF;
  654                 return (1);
  655         } else {
  656                 kn->kn_data = ttydisc_read_poll(tp);
  657                 return (kn->kn_data > 0);
  658         }
  659 }
  660 
  661 static void
  662 tty_kqops_write_detach(struct knote *kn)
  663 {
  664         struct tty *tp = kn->kn_hook;
  665 
  666         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  667 }
  668 
  669 static int
  670 tty_kqops_write_event(struct knote *kn, long hint)
  671 {
  672         struct tty *tp = kn->kn_hook;
  673 
  674         tty_lock_assert(tp, MA_OWNED);
  675 
  676         if (tty_gone(tp)) {
  677                 kn->kn_flags |= EV_EOF;
  678                 return (1);
  679         } else {
  680                 kn->kn_data = ttydisc_write_poll(tp);
  681                 return (kn->kn_data > 0);
  682         }
  683 }
  684 
  685 static struct filterops tty_kqops_read = {
  686         .f_isfd = 1,
  687         .f_detach = tty_kqops_read_detach,
  688         .f_event = tty_kqops_read_event,
  689 };
  690 static struct filterops tty_kqops_write = {
  691         .f_isfd = 1,
  692         .f_detach = tty_kqops_write_detach,
  693         .f_event = tty_kqops_write_event,
  694 };
  695 
  696 static int
  697 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  698 {
  699         struct tty *tp = dev->si_drv1;
  700         int error;
  701 
  702         error = ttydev_enter(tp);
  703         if (error)
  704                 return (error);
  705 
  706         switch (kn->kn_filter) {
  707         case EVFILT_READ:
  708                 kn->kn_hook = tp;
  709                 kn->kn_fop = &tty_kqops_read;
  710                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  711                 break;
  712         case EVFILT_WRITE:
  713                 kn->kn_hook = tp;
  714                 kn->kn_fop = &tty_kqops_write;
  715                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  716                 break;
  717         default:
  718                 error = EINVAL;
  719                 break;
  720         }
  721 
  722         tty_unlock(tp);
  723         return (error);
  724 }
  725 
  726 static struct cdevsw ttydev_cdevsw = {
  727         .d_version      = D_VERSION,
  728         .d_open         = ttydev_open,
  729         .d_close        = ttydev_close,
  730         .d_read         = ttydev_read,
  731         .d_write        = ttydev_write,
  732         .d_ioctl        = ttydev_ioctl,
  733         .d_kqfilter     = ttydev_kqfilter,
  734         .d_poll         = ttydev_poll,
  735         .d_mmap         = ttydev_mmap,
  736         .d_name         = "ttydev",
  737         .d_flags        = D_TTY,
  738 };
  739 
  740 /*
  741  * Init/lock-state devices
  742  */
  743 
  744 static int
  745 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  746 {
  747         struct tty *tp;
  748         int error = 0;
  749 
  750         while ((tp = dev->si_drv1) == NULL) {
  751                 error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
  752                 if (error != EWOULDBLOCK)
  753                         return (error);
  754         }
  755         tty_lock(tp);
  756         if (tty_gone(tp))
  757                 error = ENODEV;
  758         tty_unlock(tp);
  759 
  760         return (error);
  761 }
  762 
  763 static int
  764 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
  765 {
  766         return (0);
  767 }
  768 
  769 static int
  770 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
  771 {
  772         return (ENODEV);
  773 }
  774 
  775 static int
  776 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  777     struct thread *td)
  778 {
  779         struct tty *tp = dev->si_drv1;
  780         int error;
  781 
  782         tty_lock(tp);
  783         if (tty_gone(tp)) {
  784                 error = ENODEV;
  785                 goto done;
  786         }
  787 
  788         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
  789         if (error != ENOIOCTL)
  790                 goto done;
  791         error = 0;
  792 
  793         switch (cmd) {
  794         case TIOCGETA:
  795                 /* Obtain terminal flags through tcgetattr(). */
  796                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  797                 break;
  798         case TIOCSETA:
  799                 /* Set terminal flags through tcsetattr(). */
  800                 error = priv_check(td, PRIV_TTY_SETA);
  801                 if (error)
  802                         break;
  803                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  804                 break;
  805         case TIOCGETD:
  806                 *(int *)data = TTYDISC;
  807                 break;
  808         case TIOCGWINSZ:
  809                 bzero(data, sizeof(struct winsize));
  810                 break;
  811         default:
  812                 error = ENOTTY;
  813         }
  814 
  815 done:   tty_unlock(tp);
  816         return (error);
  817 }
  818 
  819 static struct cdevsw ttyil_cdevsw = {
  820         .d_version      = D_VERSION,
  821         .d_open         = ttyil_open,
  822         .d_close        = ttyil_close,
  823         .d_read         = ttyil_rdwr,
  824         .d_write        = ttyil_rdwr,
  825         .d_ioctl        = ttyil_ioctl,
  826         .d_name         = "ttyil",
  827         .d_flags        = D_TTY,
  828 };
  829 
  830 static void
  831 tty_init_termios(struct tty *tp)
  832 {
  833         struct termios *t = &tp->t_termios_init_in;
  834 
  835         t->c_cflag = TTYDEF_CFLAG;
  836         t->c_iflag = TTYDEF_IFLAG;
  837         t->c_lflag = TTYDEF_LFLAG;
  838         t->c_oflag = TTYDEF_OFLAG;
  839         t->c_ispeed = TTYDEF_SPEED;
  840         t->c_ospeed = TTYDEF_SPEED;
  841         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  842 
  843         tp->t_termios_init_out = *t;
  844 }
  845 
  846 void
  847 tty_init_console(struct tty *tp, speed_t s)
  848 {
  849         struct termios *ti = &tp->t_termios_init_in;
  850         struct termios *to = &tp->t_termios_init_out;
  851 
  852         if (s != 0) {
  853                 ti->c_ispeed = ti->c_ospeed = s;
  854                 to->c_ispeed = to->c_ospeed = s;
  855         }
  856 
  857         ti->c_cflag |= CLOCAL;
  858         to->c_cflag |= CLOCAL;
  859 }
  860 
  861 /*
  862  * Standard device routine implementations, mostly meant for
  863  * pseudo-terminal device drivers. When a driver creates a new terminal
  864  * device class, missing routines are patched.
  865  */
  866 
  867 static int
  868 ttydevsw_defopen(struct tty *tp)
  869 {
  870 
  871         return (0);
  872 }
  873 
  874 static void
  875 ttydevsw_defclose(struct tty *tp)
  876 {
  877 }
  878 
  879 static void
  880 ttydevsw_defoutwakeup(struct tty *tp)
  881 {
  882 
  883         panic("Terminal device has output, while not implemented");
  884 }
  885 
  886 static void
  887 ttydevsw_definwakeup(struct tty *tp)
  888 {
  889 }
  890 
  891 static int
  892 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
  893 {
  894 
  895         return (ENOIOCTL);
  896 }
  897 
  898 static int
  899 ttydevsw_defcioctl(struct tty *tp, int unit, u_long cmd, caddr_t data, struct thread *td)
  900 {
  901 
  902         return (ENOIOCTL);
  903 }
  904 
  905 static int
  906 ttydevsw_defparam(struct tty *tp, struct termios *t)
  907 {
  908 
  909         /*
  910          * Allow the baud rate to be adjusted for pseudo-devices, but at
  911          * least restrict it to 115200 to prevent excessive buffer
  912          * usage.  Also disallow 0, to prevent foot shooting.
  913          */
  914         if (t->c_ispeed < B50)
  915                 t->c_ispeed = B50;
  916         else if (t->c_ispeed > B115200)
  917                 t->c_ispeed = B115200;
  918         if (t->c_ospeed < B50)
  919                 t->c_ospeed = B50;
  920         else if (t->c_ospeed > B115200)
  921                 t->c_ospeed = B115200;
  922         t->c_cflag |= CREAD;
  923 
  924         return (0);
  925 }
  926 
  927 static int
  928 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
  929 {
  930 
  931         /* Simulate a carrier to make the TTY layer happy. */
  932         return (SER_DCD);
  933 }
  934 
  935 static int
  936 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
  937     int nprot, vm_memattr_t *memattr)
  938 {
  939 
  940         return (-1);
  941 }
  942 
  943 static void
  944 ttydevsw_defpktnotify(struct tty *tp, char event)
  945 {
  946 }
  947 
  948 static void
  949 ttydevsw_deffree(void *softc)
  950 {
  951 
  952         panic("Terminal device freed without a free-handler");
  953 }
  954 
  955 /*
  956  * TTY allocation and deallocation. TTY devices can be deallocated when
  957  * the driver doesn't use it anymore, when the TTY isn't a session's
  958  * controlling TTY and when the device node isn't opened through devfs.
  959  */
  960 
  961 struct tty *
  962 tty_alloc(struct ttydevsw *tsw, void *sc)
  963 {
  964 
  965         return (tty_alloc_mutex(tsw, sc, NULL));
  966 }
  967 
  968 struct tty *
  969 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
  970 {
  971         struct tty *tp;
  972 
  973         /* Make sure the driver defines all routines. */
  974 #define PATCH_FUNC(x) do {                              \
  975         if (tsw->tsw_ ## x == NULL)                     \
  976                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
  977 } while (0)
  978         PATCH_FUNC(open);
  979         PATCH_FUNC(close);
  980         PATCH_FUNC(outwakeup);
  981         PATCH_FUNC(inwakeup);
  982         PATCH_FUNC(ioctl);
  983         PATCH_FUNC(cioctl);
  984         PATCH_FUNC(param);
  985         PATCH_FUNC(modem);
  986         PATCH_FUNC(mmap);
  987         PATCH_FUNC(pktnotify);
  988         PATCH_FUNC(free);
  989 #undef PATCH_FUNC
  990 
  991         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
  992         tp->t_devsw = tsw;
  993         tp->t_devswsoftc = sc;
  994         tp->t_flags = tsw->tsw_flags;
  995 
  996         tty_init_termios(tp);
  997 
  998         cv_init(&tp->t_inwait, "ttyin");
  999         cv_init(&tp->t_outwait, "ttyout");
 1000         cv_init(&tp->t_outserwait, "ttyosr");
 1001         cv_init(&tp->t_bgwait, "ttybg");
 1002         cv_init(&tp->t_dcdwait, "ttydcd");
 1003 
 1004         /* Allow drivers to use a custom mutex to lock the TTY. */
 1005         if (mutex != NULL) {
 1006                 tp->t_mtx = mutex;
 1007         } else {
 1008                 tp->t_mtx = &tp->t_mtxobj;
 1009                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
 1010         }
 1011 
 1012         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 1013         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 1014 
 1015         sx_xlock(&tty_list_sx);
 1016         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
 1017         tty_list_count++;
 1018         sx_xunlock(&tty_list_sx);
 1019 
 1020         return (tp);
 1021 }
 1022 
 1023 static void
 1024 tty_dealloc(void *arg)
 1025 {
 1026         struct tty *tp = arg;
 1027 
 1028         sx_xlock(&tty_list_sx);
 1029         TAILQ_REMOVE(&tty_list, tp, t_list);
 1030         tty_list_count--;
 1031         sx_xunlock(&tty_list_sx);
 1032 
 1033         /* Make sure we haven't leaked buffers. */
 1034         MPASS(ttyinq_getsize(&tp->t_inq) == 0);
 1035         MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
 1036 
 1037         seldrain(&tp->t_inpoll);
 1038         seldrain(&tp->t_outpoll);
 1039         knlist_destroy(&tp->t_inpoll.si_note);
 1040         knlist_destroy(&tp->t_outpoll.si_note);
 1041 
 1042         cv_destroy(&tp->t_inwait);
 1043         cv_destroy(&tp->t_outwait);
 1044         cv_destroy(&tp->t_bgwait);
 1045         cv_destroy(&tp->t_dcdwait);
 1046         cv_destroy(&tp->t_outserwait);
 1047 
 1048         if (tp->t_mtx == &tp->t_mtxobj)
 1049                 mtx_destroy(&tp->t_mtxobj);
 1050         ttydevsw_free(tp);
 1051         free(tp, M_TTY);
 1052 }
 1053 
 1054 static void
 1055 tty_rel_free(struct tty *tp)
 1056 {
 1057         struct cdev *dev;
 1058 
 1059         tty_lock_assert(tp, MA_OWNED);
 1060 
 1061 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1062         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1063                 /* TTY is still in use. */
 1064                 tty_unlock(tp);
 1065                 return;
 1066         }
 1067 
 1068         /* TTY can be deallocated. */
 1069         dev = tp->t_dev;
 1070         tp->t_dev = NULL;
 1071         tty_unlock(tp);
 1072 
 1073         if (dev != NULL)
 1074                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1075 }
 1076 
 1077 void
 1078 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1079 {
 1080         MPASS(tp->t_sessioncnt > 0);
 1081         tty_lock_assert(tp, MA_OWNED);
 1082 
 1083         if (tp->t_pgrp == pg)
 1084                 tp->t_pgrp = NULL;
 1085 
 1086         tty_unlock(tp);
 1087 }
 1088 
 1089 void
 1090 tty_rel_sess(struct tty *tp, struct session *sess)
 1091 {
 1092         MPASS(tp->t_sessioncnt > 0);
 1093 
 1094         /* Current session has left. */
 1095         if (tp->t_session == sess) {
 1096                 tp->t_session = NULL;
 1097                 MPASS(tp->t_pgrp == NULL);
 1098         }
 1099         tp->t_sessioncnt--;
 1100         tty_rel_free(tp);
 1101 }
 1102 
 1103 void
 1104 tty_rel_gone(struct tty *tp)
 1105 {
 1106         MPASS(!tty_gone(tp));
 1107 
 1108         /* Simulate carrier removal. */
 1109         ttydisc_modem(tp, 0);
 1110 
 1111         /* Wake up all blocked threads. */
 1112         tty_wakeup(tp, FREAD|FWRITE);
 1113         cv_broadcast(&tp->t_bgwait);
 1114         cv_broadcast(&tp->t_dcdwait);
 1115 
 1116         tp->t_flags |= TF_GONE;
 1117         tty_rel_free(tp);
 1118 }
 1119 
 1120 /*
 1121  * Exposing information about current TTY's through sysctl
 1122  */
 1123 
 1124 static void
 1125 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1126 {
 1127         tty_lock_assert(tp, MA_OWNED);
 1128 
 1129         xt->xt_size = sizeof(struct xtty);
 1130         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1131         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1132         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1133         xt->xt_inlow = tp->t_inlow;
 1134         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1135         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1136         xt->xt_outlow = tp->t_outlow;
 1137         xt->xt_column = tp->t_column;
 1138         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1139         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1140         xt->xt_flags = tp->t_flags;
 1141         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1142 }
 1143 
 1144 static int
 1145 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1146 {
 1147         unsigned long lsize;
 1148         struct xtty *xtlist, *xt;
 1149         struct tty *tp;
 1150         int error;
 1151 
 1152         sx_slock(&tty_list_sx);
 1153         lsize = tty_list_count * sizeof(struct xtty);
 1154         if (lsize == 0) {
 1155                 sx_sunlock(&tty_list_sx);
 1156                 return (0);
 1157         }
 1158 
 1159         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1160 
 1161         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1162                 tty_lock(tp);
 1163                 tty_to_xtty(tp, xt);
 1164                 tty_unlock(tp);
 1165                 xt++;
 1166         }
 1167         sx_sunlock(&tty_list_sx);
 1168 
 1169         error = SYSCTL_OUT(req, xtlist, lsize);
 1170         free(xtlist, M_TTY);
 1171         return (error);
 1172 }
 1173 
 1174 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1175         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1176 
 1177 /*
 1178  * Device node creation. Device has been set up, now we can expose it to
 1179  * the user.
 1180  */
 1181 
 1182 void
 1183 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
 1184 {
 1185         va_list ap;
 1186         struct cdev *dev;
 1187         const char *prefix = "tty";
 1188         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1189         uid_t uid;
 1190         gid_t gid;
 1191         mode_t mode;
 1192 
 1193         /* Remove "tty" prefix from devices like PTY's. */
 1194         if (tp->t_flags & TF_NOPREFIX)
 1195                 prefix = "";
 1196 
 1197         va_start(ap, fmt);
 1198         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1199         va_end(ap);
 1200 
 1201         if (cred == NULL) {
 1202                 /* System device. */
 1203                 uid = UID_ROOT;
 1204                 gid = GID_WHEEL;
 1205                 mode = S_IRUSR|S_IWUSR;
 1206         } else {
 1207                 /* User device. */
 1208                 uid = cred->cr_ruid;
 1209                 gid = GID_TTY;
 1210                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1211         }
 1212 
 1213         /* Master call-in device. */
 1214         dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
 1215             uid, gid, mode, "%s%s", prefix, name);
 1216         dev->si_drv1 = tp;
 1217         wakeup(&dev->si_drv1);
 1218         tp->t_dev = dev;
 1219 
 1220         /* Slave call-in devices. */
 1221         if (tp->t_flags & TF_INITLOCK) {
 1222                 dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_INIT, cred,
 1223                     uid, gid, mode, "%s%s.init", prefix, name);
 1224                 dev_depends(tp->t_dev, dev);
 1225                 dev->si_drv1 = tp;
 1226                 wakeup(&dev->si_drv1);
 1227                 dev->si_drv2 = &tp->t_termios_init_in;
 1228 
 1229                 dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_LOCK, cred,
 1230                     uid, gid, mode, "%s%s.lock", prefix, name);
 1231                 dev_depends(tp->t_dev, dev);
 1232                 dev->si_drv1 = tp;
 1233                 wakeup(&dev->si_drv1);
 1234                 dev->si_drv2 = &tp->t_termios_lock_in;
 1235         }
 1236 
 1237         /* Call-out devices. */
 1238         if (tp->t_flags & TF_CALLOUT) {
 1239                 dev = make_dev_cred(&ttydev_cdevsw, TTYUNIT_CALLOUT, cred,
 1240                     UID_UUCP, GID_DIALER, 0660, "cua%s", name);
 1241                 dev_depends(tp->t_dev, dev);
 1242                 dev->si_drv1 = tp;
 1243                 wakeup(&dev->si_drv1);
 1244 
 1245                 /* Slave call-out devices. */
 1246                 if (tp->t_flags & TF_INITLOCK) {
 1247                         dev = make_dev_cred(&ttyil_cdevsw, 
 1248                             TTYUNIT_CALLOUT | TTYUNIT_INIT, cred,
 1249                             UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
 1250                         dev_depends(tp->t_dev, dev);
 1251                         dev->si_drv1 = tp;
 1252                         wakeup(&dev->si_drv1);
 1253                         dev->si_drv2 = &tp->t_termios_init_out;
 1254 
 1255                         dev = make_dev_cred(&ttyil_cdevsw,
 1256                             TTYUNIT_CALLOUT | TTYUNIT_LOCK, cred,
 1257                             UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
 1258                         dev_depends(tp->t_dev, dev);
 1259                         dev->si_drv1 = tp;
 1260                         wakeup(&dev->si_drv1);
 1261                         dev->si_drv2 = &tp->t_termios_lock_out;
 1262                 }
 1263         }
 1264 }
 1265 
 1266 /*
 1267  * Signalling processes.
 1268  */
 1269 
 1270 void
 1271 tty_signal_sessleader(struct tty *tp, int sig)
 1272 {
 1273         struct proc *p;
 1274 
 1275         tty_lock_assert(tp, MA_OWNED);
 1276         MPASS(sig >= 1 && sig < NSIG);
 1277 
 1278         /* Make signals start output again. */
 1279         tp->t_flags &= ~TF_STOPPED;
 1280 
 1281         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1282                 p = tp->t_session->s_leader;
 1283                 PROC_LOCK(p);
 1284                 kern_psignal(p, sig);
 1285                 PROC_UNLOCK(p);
 1286         }
 1287 }
 1288 
 1289 void
 1290 tty_signal_pgrp(struct tty *tp, int sig)
 1291 {
 1292         ksiginfo_t ksi;
 1293 
 1294         tty_lock_assert(tp, MA_OWNED);
 1295         MPASS(sig >= 1 && sig < NSIG);
 1296 
 1297         /* Make signals start output again. */
 1298         tp->t_flags &= ~TF_STOPPED;
 1299 
 1300         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1301                 tty_info(tp);
 1302         if (tp->t_pgrp != NULL) {
 1303                 ksiginfo_init(&ksi);
 1304                 ksi.ksi_signo = sig;
 1305                 ksi.ksi_code = SI_KERNEL;
 1306                 PGRP_LOCK(tp->t_pgrp);
 1307                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1308                 PGRP_UNLOCK(tp->t_pgrp);
 1309         }
 1310 }
 1311 
 1312 void
 1313 tty_wakeup(struct tty *tp, int flags)
 1314 {
 1315         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1316                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1317 
 1318         if (flags & FWRITE) {
 1319                 cv_broadcast(&tp->t_outwait);
 1320                 selwakeup(&tp->t_outpoll);
 1321                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1322         }
 1323         if (flags & FREAD) {
 1324                 cv_broadcast(&tp->t_inwait);
 1325                 selwakeup(&tp->t_inpoll);
 1326                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1327         }
 1328 }
 1329 
 1330 int
 1331 tty_wait(struct tty *tp, struct cv *cv)
 1332 {
 1333         int error;
 1334         int revokecnt = tp->t_revokecnt;
 1335 
 1336         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1337         MPASS(!tty_gone(tp));
 1338 
 1339         error = cv_wait_sig(cv, tp->t_mtx);
 1340 
 1341         /* Restart the system call when we may have been revoked. */
 1342         if (tp->t_revokecnt != revokecnt)
 1343                 return (ERESTART);
 1344 
 1345         /* Bail out when the device slipped away. */
 1346         if (tty_gone(tp))
 1347                 return (ENXIO);
 1348 
 1349         return (error);
 1350 }
 1351 
 1352 int
 1353 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1354 {
 1355         int error;
 1356         int revokecnt = tp->t_revokecnt;
 1357 
 1358         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1359         MPASS(!tty_gone(tp));
 1360 
 1361         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1362 
 1363         /* Restart the system call when we may have been revoked. */
 1364         if (tp->t_revokecnt != revokecnt)
 1365                 return (ERESTART);
 1366 
 1367         /* Bail out when the device slipped away. */
 1368         if (tty_gone(tp))
 1369                 return (ENXIO);
 1370 
 1371         return (error);
 1372 }
 1373 
 1374 void
 1375 tty_flush(struct tty *tp, int flags)
 1376 {
 1377         if (flags & FWRITE) {
 1378                 tp->t_flags &= ~TF_HIWAT_OUT;
 1379                 ttyoutq_flush(&tp->t_outq);
 1380                 tty_wakeup(tp, FWRITE);
 1381                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1382         }
 1383         if (flags & FREAD) {
 1384                 tty_hiwat_in_unblock(tp);
 1385                 ttyinq_flush(&tp->t_inq);
 1386                 ttydevsw_inwakeup(tp);
 1387                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1388         }
 1389 }
 1390 
 1391 static int
 1392 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1393     struct thread *td)
 1394 {
 1395         int error;
 1396 
 1397         switch (cmd) {
 1398         /*
 1399          * Modem commands.
 1400          * The SER_* and TIOCM_* flags are the same, but one bit
 1401          * shifted. I don't know why.
 1402          */
 1403         case TIOCSDTR:
 1404                 ttydevsw_modem(tp, SER_DTR, 0);
 1405                 return (0);
 1406         case TIOCCDTR:
 1407                 ttydevsw_modem(tp, 0, SER_DTR);
 1408                 return (0);
 1409         case TIOCMSET: {
 1410                 int bits = *(int *)data;
 1411                 ttydevsw_modem(tp,
 1412                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1413                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1414                 return (0);
 1415         }
 1416         case TIOCMBIS: {
 1417                 int bits = *(int *)data;
 1418                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1419                 return (0);
 1420         }
 1421         case TIOCMBIC: {
 1422                 int bits = *(int *)data;
 1423                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1424                 return (0);
 1425         }
 1426         case TIOCMGET:
 1427                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1428                 return (0);
 1429 
 1430         case FIOASYNC:
 1431                 if (*(int *)data)
 1432                         tp->t_flags |= TF_ASYNC;
 1433                 else
 1434                         tp->t_flags &= ~TF_ASYNC;
 1435                 return (0);
 1436         case FIONBIO:
 1437                 /* This device supports non-blocking operation. */
 1438                 return (0);
 1439         case FIONREAD:
 1440                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1441                 return (0);
 1442         case FIONWRITE:
 1443         case TIOCOUTQ:
 1444                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1445                 return (0);
 1446         case FIOSETOWN:
 1447                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1448                         /* Not allowed to set ownership. */
 1449                         return (ENOTTY);
 1450 
 1451                 /* Temporarily unlock the TTY to set ownership. */
 1452                 tty_unlock(tp);
 1453                 error = fsetown(*(int *)data, &tp->t_sigio);
 1454                 tty_lock(tp);
 1455                 return (error);
 1456         case FIOGETOWN:
 1457                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1458                         /* Not allowed to set ownership. */
 1459                         return (ENOTTY);
 1460 
 1461                 /* Get ownership. */
 1462                 *(int *)data = fgetown(&tp->t_sigio);
 1463                 return (0);
 1464         case TIOCGETA:
 1465                 /* Obtain terminal flags through tcgetattr(). */
 1466                 *(struct termios*)data = tp->t_termios;
 1467                 return (0);
 1468         case TIOCSETA:
 1469         case TIOCSETAW:
 1470         case TIOCSETAF: {
 1471                 struct termios *t = data;
 1472 
 1473                 /*
 1474                  * Who makes up these funny rules? According to POSIX,
 1475                  * input baud rate is set equal to the output baud rate
 1476                  * when zero.
 1477                  */
 1478                 if (t->c_ispeed == 0)
 1479                         t->c_ispeed = t->c_ospeed;
 1480 
 1481                 /* Discard any unsupported bits. */
 1482                 t->c_iflag &= TTYSUP_IFLAG;
 1483                 t->c_oflag &= TTYSUP_OFLAG;
 1484                 t->c_lflag &= TTYSUP_LFLAG;
 1485                 t->c_cflag &= TTYSUP_CFLAG;
 1486 
 1487                 /* Set terminal flags through tcsetattr(). */
 1488                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1489                         error = tty_drain(tp);
 1490                         if (error)
 1491                                 return (error);
 1492                         if (cmd == TIOCSETAF)
 1493                                 tty_flush(tp, FREAD);
 1494                 }
 1495 
 1496                 /*
 1497                  * Only call param() when the flags really change.
 1498                  */
 1499                 if ((t->c_cflag & CIGNORE) == 0 &&
 1500                     (tp->t_termios.c_cflag != t->c_cflag ||
 1501                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
 1502                     (IXON|IXOFF|IXANY)) ||
 1503                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1504                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1505                         error = ttydevsw_param(tp, t);
 1506                         if (error)
 1507                                 return (error);
 1508 
 1509                         /* XXX: CLOCAL? */
 1510 
 1511                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1512                         tp->t_termios.c_ispeed = t->c_ispeed;
 1513                         tp->t_termios.c_ospeed = t->c_ospeed;
 1514 
 1515                         /* Baud rate has changed - update watermarks. */
 1516                         tty_watermarks(tp);
 1517                 }
 1518 
 1519                 /* Copy new non-device driver parameters. */
 1520                 tp->t_termios.c_iflag = t->c_iflag;
 1521                 tp->t_termios.c_oflag = t->c_oflag;
 1522                 tp->t_termios.c_lflag = t->c_lflag;
 1523                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1524 
 1525                 ttydisc_optimize(tp);
 1526 
 1527                 if ((t->c_lflag & ICANON) == 0) {
 1528                         /*
 1529                          * When in non-canonical mode, wake up all
 1530                          * readers. Canonicalize any partial input. VMIN
 1531                          * and VTIME could also be adjusted.
 1532                          */
 1533                         ttyinq_canonicalize(&tp->t_inq);
 1534                         tty_wakeup(tp, FREAD);
 1535                 }
 1536 
 1537                 /*
 1538                  * For packet mode: notify the PTY consumer that VSTOP
 1539                  * and VSTART may have been changed.
 1540                  */
 1541                 if (tp->t_termios.c_iflag & IXON &&
 1542                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1543                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1544                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1545                 else
 1546                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1547                 return (0);
 1548         }
 1549         case TIOCGETD:
 1550                 /* For compatibility - we only support TTYDISC. */
 1551                 *(int *)data = TTYDISC;
 1552                 return (0);
 1553         case TIOCGPGRP:
 1554                 if (!tty_is_ctty(tp, td->td_proc))
 1555                         return (ENOTTY);
 1556 
 1557                 if (tp->t_pgrp != NULL)
 1558                         *(int *)data = tp->t_pgrp->pg_id;
 1559                 else
 1560                         *(int *)data = NO_PID;
 1561                 return (0);
 1562         case TIOCGSID:
 1563                 if (!tty_is_ctty(tp, td->td_proc))
 1564                         return (ENOTTY);
 1565 
 1566                 MPASS(tp->t_session);
 1567                 *(int *)data = tp->t_session->s_sid;
 1568                 return (0);
 1569         case TIOCSCTTY: {
 1570                 struct proc *p = td->td_proc;
 1571 
 1572                 /* XXX: This looks awful. */
 1573                 tty_unlock(tp);
 1574                 sx_xlock(&proctree_lock);
 1575                 tty_lock(tp);
 1576 
 1577                 if (!SESS_LEADER(p)) {
 1578                         /* Only the session leader may do this. */
 1579                         sx_xunlock(&proctree_lock);
 1580                         return (EPERM);
 1581                 }
 1582 
 1583                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1584                         /* This is already our controlling TTY. */
 1585                         sx_xunlock(&proctree_lock);
 1586                         return (0);
 1587                 }
 1588 
 1589                 if (p->p_session->s_ttyp != NULL ||
 1590                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1591                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1592                         /*
 1593                          * There is already a relation between a TTY and
 1594                          * a session, or the caller is not the session
 1595                          * leader.
 1596                          *
 1597                          * Allow the TTY to be stolen when the vnode is
 1598                          * invalid, but the reference to the TTY is
 1599                          * still active.  This allows immediate reuse of
 1600                          * TTYs of which the session leader has been
 1601                          * killed or the TTY revoked.
 1602                          */
 1603                         sx_xunlock(&proctree_lock);
 1604                         return (EPERM);
 1605                 }
 1606 
 1607                 /* Connect the session to the TTY. */
 1608                 tp->t_session = p->p_session;
 1609                 tp->t_session->s_ttyp = tp;
 1610                 tp->t_sessioncnt++;
 1611                 sx_xunlock(&proctree_lock);
 1612 
 1613                 /* Assign foreground process group. */
 1614                 tp->t_pgrp = p->p_pgrp;
 1615                 PROC_LOCK(p);
 1616                 p->p_flag |= P_CONTROLT;
 1617                 PROC_UNLOCK(p);
 1618 
 1619                 return (0);
 1620         }
 1621         case TIOCSPGRP: {
 1622                 struct pgrp *pg;
 1623 
 1624                 /*
 1625                  * XXX: Temporarily unlock the TTY to locate the process
 1626                  * group. This code would be lot nicer if we would ever
 1627                  * decompose proctree_lock.
 1628                  */
 1629                 tty_unlock(tp);
 1630                 sx_slock(&proctree_lock);
 1631                 pg = pgfind(*(int *)data);
 1632                 if (pg != NULL)
 1633                         PGRP_UNLOCK(pg);
 1634                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1635                         sx_sunlock(&proctree_lock);
 1636                         tty_lock(tp);
 1637                         return (EPERM);
 1638                 }
 1639                 tty_lock(tp);
 1640 
 1641                 /*
 1642                  * Determine if this TTY is the controlling TTY after
 1643                  * relocking the TTY.
 1644                  */
 1645                 if (!tty_is_ctty(tp, td->td_proc)) {
 1646                         sx_sunlock(&proctree_lock);
 1647                         return (ENOTTY);
 1648                 }
 1649                 tp->t_pgrp = pg;
 1650                 sx_sunlock(&proctree_lock);
 1651 
 1652                 /* Wake up the background process groups. */
 1653                 cv_broadcast(&tp->t_bgwait);
 1654                 return (0);
 1655         }
 1656         case TIOCFLUSH: {
 1657                 int flags = *(int *)data;
 1658 
 1659                 if (flags == 0)
 1660                         flags = (FREAD|FWRITE);
 1661                 else
 1662                         flags &= (FREAD|FWRITE);
 1663                 tty_flush(tp, flags);
 1664                 return (0);
 1665         }
 1666         case TIOCDRAIN:
 1667                 /* Drain TTY output. */
 1668                 return tty_drain(tp);
 1669         case TIOCCONS:
 1670                 /* Set terminal as console TTY. */
 1671                 if (*(int *)data) {
 1672                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1673                         if (error)
 1674                                 return (error);
 1675 
 1676                         /*
 1677                          * XXX: constty should really need to be locked!
 1678                          * XXX: allow disconnected constty's to be stolen!
 1679                          */
 1680 
 1681                         if (constty == tp)
 1682                                 return (0);
 1683                         if (constty != NULL)
 1684                                 return (EBUSY);
 1685 
 1686                         tty_unlock(tp);
 1687                         constty_set(tp);
 1688                         tty_lock(tp);
 1689                 } else if (constty == tp) {
 1690                         constty_clear();
 1691                 }
 1692                 return (0);
 1693         case TIOCGWINSZ:
 1694                 /* Obtain window size. */
 1695                 *(struct winsize*)data = tp->t_winsize;
 1696                 return (0);
 1697         case TIOCSWINSZ:
 1698                 /* Set window size. */
 1699                 if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
 1700                         return (0);
 1701                 tp->t_winsize = *(struct winsize*)data;
 1702                 tty_signal_pgrp(tp, SIGWINCH);
 1703                 return (0);
 1704         case TIOCEXCL:
 1705                 tp->t_flags |= TF_EXCLUDE;
 1706                 return (0);
 1707         case TIOCNXCL:
 1708                 tp->t_flags &= ~TF_EXCLUDE;
 1709                 return (0);
 1710         case TIOCSTOP:
 1711                 tp->t_flags |= TF_STOPPED;
 1712                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1713                 return (0);
 1714         case TIOCSTART:
 1715                 tp->t_flags &= ~TF_STOPPED;
 1716                 ttydevsw_outwakeup(tp);
 1717                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1718                 return (0);
 1719         case TIOCSTAT:
 1720                 tty_info(tp);
 1721                 return (0);
 1722         case TIOCSTI:
 1723                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1724                         return (EPERM);
 1725                 if (!tty_is_ctty(tp, td->td_proc) &&
 1726                     priv_check(td, PRIV_TTY_STI))
 1727                         return (EACCES);
 1728                 ttydisc_rint(tp, *(char *)data, 0);
 1729                 ttydisc_rint_done(tp);
 1730                 return (0);
 1731         }
 1732 
 1733 #ifdef COMPAT_43TTY
 1734         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1735 #else /* !COMPAT_43TTY */
 1736         return (ENOIOCTL);
 1737 #endif /* COMPAT_43TTY */
 1738 }
 1739 
 1740 int
 1741 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1742 {
 1743         int error;
 1744 
 1745         tty_lock_assert(tp, MA_OWNED);
 1746 
 1747         if (tty_gone(tp))
 1748                 return (ENXIO);
 1749 
 1750         error = ttydevsw_ioctl(tp, cmd, data, td);
 1751         if (error == ENOIOCTL)
 1752                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1753 
 1754         return (error);
 1755 }
 1756 
 1757 dev_t
 1758 tty_udev(struct tty *tp)
 1759 {
 1760         if (tp->t_dev)
 1761                 return dev2udev(tp->t_dev);
 1762         else
 1763                 return NODEV;
 1764 }
 1765 
 1766 int
 1767 tty_checkoutq(struct tty *tp)
 1768 {
 1769 
 1770         /* 256 bytes should be enough to print a log message. */
 1771         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1772 }
 1773 
 1774 void
 1775 tty_hiwat_in_block(struct tty *tp)
 1776 {
 1777 
 1778         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1779             tp->t_termios.c_iflag & IXOFF &&
 1780             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1781                 /*
 1782                  * Input flow control. Only enter the high watermark when we
 1783                  * can successfully store the VSTOP character.
 1784                  */
 1785                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1786                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1787                         tp->t_flags |= TF_HIWAT_IN;
 1788         } else {
 1789                 /* No input flow control. */
 1790                 tp->t_flags |= TF_HIWAT_IN;
 1791         }
 1792 }
 1793 
 1794 void
 1795 tty_hiwat_in_unblock(struct tty *tp)
 1796 {
 1797 
 1798         if (tp->t_flags & TF_HIWAT_IN &&
 1799             tp->t_termios.c_iflag & IXOFF &&
 1800             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1801                 /*
 1802                  * Input flow control. Only leave the high watermark when we
 1803                  * can successfully store the VSTART character.
 1804                  */
 1805                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1806                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1807                         tp->t_flags &= ~TF_HIWAT_IN;
 1808         } else {
 1809                 /* No input flow control. */
 1810                 tp->t_flags &= ~TF_HIWAT_IN;
 1811         }
 1812 
 1813         if (!tty_gone(tp))
 1814                 ttydevsw_inwakeup(tp);
 1815 }
 1816 
 1817 /*
 1818  * TTY hooks interface.
 1819  */
 1820 
 1821 static int
 1822 ttyhook_defrint(struct tty *tp, char c, int flags)
 1823 {
 1824 
 1825         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1826                 return (-1);
 1827 
 1828         return (0);
 1829 }
 1830 
 1831 int
 1832 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
 1833     struct ttyhook *th, void *softc)
 1834 {
 1835         struct tty *tp;
 1836         struct file *fp;
 1837 #ifdef CAPABILITIES
 1838         struct file *fp_cap;
 1839 #endif
 1840         struct cdev *dev;
 1841         struct cdevsw *cdp;
 1842         struct filedesc *fdp;
 1843         int error, ref;
 1844 
 1845         /* Validate the file descriptor. */
 1846         if ((fdp = p->p_fd) == NULL)
 1847                 return (EBADF);
 1848 
 1849         fp = fget_unlocked(fdp, fd);
 1850         if (fp == NULL)
 1851                 return (EBADF);
 1852         if (fp->f_ops == &badfileops) {
 1853                 error = EBADF;
 1854                 goto done1;
 1855         }
 1856 
 1857 #ifdef CAPABILITIES
 1858         fp_cap = fp;
 1859         error = cap_funwrap(fp_cap, CAP_TTYHOOK, &fp);
 1860         if (error)
 1861                 return (error);
 1862 #endif
 1863 
 1864         /*
 1865          * Make sure the vnode is bound to a character device.
 1866          * Unlocked check for the vnode type is ok there, because we
 1867          * only shall prevent calling devvn_refthread on the file that
 1868          * never has been opened over a character device.
 1869          */
 1870         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1871                 error = EINVAL;
 1872                 goto done1;
 1873         }
 1874 
 1875         /* Make sure it is a TTY. */
 1876         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
 1877         if (cdp == NULL) {
 1878                 error = ENXIO;
 1879                 goto done1;
 1880         }
 1881         if (dev != fp->f_data) {
 1882                 error = ENXIO;
 1883                 goto done2;
 1884         }
 1885         if (cdp != &ttydev_cdevsw) {
 1886                 error = ENOTTY;
 1887                 goto done2;
 1888         }
 1889         tp = dev->si_drv1;
 1890 
 1891         /* Try to attach the hook to the TTY. */
 1892         error = EBUSY;
 1893         tty_lock(tp);
 1894         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1895         if (tp->t_flags & TF_HOOK)
 1896                 goto done3;
 1897 
 1898         tp->t_flags |= TF_HOOK;
 1899         tp->t_hook = th;
 1900         tp->t_hooksoftc = softc;
 1901         *rtp = tp;
 1902         error = 0;
 1903 
 1904         /* Maybe we can switch into bypass mode now. */
 1905         ttydisc_optimize(tp);
 1906 
 1907         /* Silently convert rint() calls to rint_bypass() when possible. */
 1908         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 1909                 th->th_rint = ttyhook_defrint;
 1910 
 1911 done3:  tty_unlock(tp);
 1912 done2:  dev_relthread(dev, ref);
 1913 done1:  fdrop(fp, curthread);
 1914         return (error);
 1915 }
 1916 
 1917 void
 1918 ttyhook_unregister(struct tty *tp)
 1919 {
 1920 
 1921         tty_lock_assert(tp, MA_OWNED);
 1922         MPASS(tp->t_flags & TF_HOOK);
 1923 
 1924         /* Disconnect the hook. */
 1925         tp->t_flags &= ~TF_HOOK;
 1926         tp->t_hook = NULL;
 1927 
 1928         /* Maybe we need to leave bypass mode. */
 1929         ttydisc_optimize(tp);
 1930 
 1931         /* Maybe deallocate the TTY as well. */
 1932         tty_rel_free(tp);
 1933 }
 1934 
 1935 /*
 1936  * /dev/console handling.
 1937  */
 1938 
 1939 static int
 1940 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 1941 {
 1942         struct tty *tp;
 1943 
 1944         /* System has no console device. */
 1945         if (dev_console_filename == NULL)
 1946                 return (ENXIO);
 1947 
 1948         /* Look up corresponding TTY by device name. */
 1949         sx_slock(&tty_list_sx);
 1950         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1951                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 1952                         dev_console->si_drv1 = tp;
 1953                         break;
 1954                 }
 1955         }
 1956         sx_sunlock(&tty_list_sx);
 1957 
 1958         /* System console has no TTY associated. */
 1959         if (dev_console->si_drv1 == NULL)
 1960                 return (ENXIO);
 1961 
 1962         return (ttydev_open(dev, oflags, devtype, td));
 1963 }
 1964 
 1965 static int
 1966 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 1967 {
 1968 
 1969         log_console(uio);
 1970 
 1971         return (ttydev_write(dev, uio, ioflag));
 1972 }
 1973 
 1974 /*
 1975  * /dev/console is a little different than normal TTY's.  When opened,
 1976  * it determines which TTY to use.  When data gets written to it, it
 1977  * will be logged in the kernel message buffer.
 1978  */
 1979 static struct cdevsw ttyconsdev_cdevsw = {
 1980         .d_version      = D_VERSION,
 1981         .d_open         = ttyconsdev_open,
 1982         .d_close        = ttydev_close,
 1983         .d_read         = ttydev_read,
 1984         .d_write        = ttyconsdev_write,
 1985         .d_ioctl        = ttydev_ioctl,
 1986         .d_kqfilter     = ttydev_kqfilter,
 1987         .d_poll         = ttydev_poll,
 1988         .d_mmap         = ttydev_mmap,
 1989         .d_name         = "ttyconsdev",
 1990         .d_flags        = D_TTY,
 1991 };
 1992 
 1993 static void
 1994 ttyconsdev_init(void *unused)
 1995 {
 1996 
 1997         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
 1998             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
 1999 }
 2000 
 2001 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 2002 
 2003 void
 2004 ttyconsdev_select(const char *name)
 2005 {
 2006 
 2007         dev_console_filename = name;
 2008 }
 2009 
 2010 /*
 2011  * Debugging routines.
 2012  */
 2013 
 2014 #include "opt_ddb.h"
 2015 #ifdef DDB
 2016 #include <ddb/ddb.h>
 2017 #include <ddb/db_sym.h>
 2018 
 2019 static struct {
 2020         int flag;
 2021         char val;
 2022 } ttystates[] = {
 2023 #if 0
 2024         { TF_NOPREFIX,          'N' },
 2025 #endif
 2026         { TF_INITLOCK,          'I' },
 2027         { TF_CALLOUT,           'C' },
 2028 
 2029         /* Keep these together -> 'Oi' and 'Oo'. */
 2030         { TF_OPENED,            'O' },
 2031         { TF_OPENED_IN,         'i' },
 2032         { TF_OPENED_OUT,        'o' },
 2033         { TF_OPENED_CONS,       'c' },
 2034 
 2035         { TF_GONE,              'G' },
 2036         { TF_OPENCLOSE,         'B' },
 2037         { TF_ASYNC,             'Y' },
 2038         { TF_LITERAL,           'L' },
 2039 
 2040         /* Keep these together -> 'Hi' and 'Ho'. */
 2041         { TF_HIWAT,             'H' },
 2042         { TF_HIWAT_IN,          'i' },
 2043         { TF_HIWAT_OUT,         'o' },
 2044 
 2045         { TF_STOPPED,           'S' },
 2046         { TF_EXCLUDE,           'X' },
 2047         { TF_BYPASS,            'l' },
 2048         { TF_ZOMBIE,            'Z' },
 2049         { TF_HOOK,              's' },
 2050 
 2051         /* Keep these together -> 'bi' and 'bo'. */
 2052         { TF_BUSY,              'b' },
 2053         { TF_BUSY_IN,           'i' },
 2054         { TF_BUSY_OUT,          'o' },
 2055 
 2056         { 0,                    '\0'},
 2057 };
 2058 
 2059 #define TTY_FLAG_BITS \
 2060         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
 2061         "\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
 2062         "\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
 2063 
 2064 #define DB_PRINTSYM(name, addr) \
 2065         db_printf("%s  " #name ": ", sep); \
 2066         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 2067         db_printf("\n");
 2068 
 2069 static void
 2070 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2071 {
 2072         db_printf("%sdevsw: ", sep);
 2073         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2074         db_printf(" (%p)\n", tsw);
 2075         DB_PRINTSYM(open, tsw->tsw_open);
 2076         DB_PRINTSYM(close, tsw->tsw_close);
 2077         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2078         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2079         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2080         DB_PRINTSYM(param, tsw->tsw_param);
 2081         DB_PRINTSYM(modem, tsw->tsw_modem);
 2082         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2083         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2084         DB_PRINTSYM(free, tsw->tsw_free);
 2085 }
 2086 static void
 2087 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2088 {
 2089         db_printf("%shook: ", sep);
 2090         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2091         db_printf(" (%p)\n", th);
 2092         if (th == NULL)
 2093                 return;
 2094         DB_PRINTSYM(rint, th->th_rint);
 2095         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2096         DB_PRINTSYM(rint_done, th->th_rint_done);
 2097         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2098         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2099         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2100         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2101         DB_PRINTSYM(close, th->th_close);
 2102 }
 2103 
 2104 static void
 2105 _db_show_termios(const char *name, const struct termios *t)
 2106 {
 2107 
 2108         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2109             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2110             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2111             t->c_ispeed, t->c_ospeed);
 2112 }
 2113 
 2114 /* DDB command to show TTY statistics. */
 2115 DB_SHOW_COMMAND(tty, db_show_tty)
 2116 {
 2117         struct tty *tp;
 2118 
 2119         if (!have_addr) {
 2120                 db_printf("usage: show tty <addr>\n");
 2121                 return;
 2122         }
 2123         tp = (struct tty *)addr;
 2124 
 2125         db_printf("0x%p: %s\n", tp, tty_devname(tp));
 2126         db_printf("\tmtx: %p\n", tp->t_mtx);
 2127         db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
 2128         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2129 
 2130         /* Buffering mechanisms. */
 2131         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2132             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2133             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2134             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2135         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2136             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2137             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2138         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2139         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2140         _db_show_termios("\ttermios", &tp->t_termios);
 2141         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2142             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2143             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2144         db_printf("\tcolumn: %u\n", tp->t_column);
 2145         db_printf("\twritepos: %u\n", tp->t_writepos);
 2146         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2147 
 2148         /* Init/lock-state devices. */
 2149         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2150         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2151         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2152         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2153 
 2154         /* Hooks */
 2155         _db_show_devsw("\t", tp->t_devsw);
 2156         _db_show_hooks("\t", tp->t_hook);
 2157 
 2158         /* Process info. */
 2159         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2160             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2161             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2162         db_printf("\tsession: %p", tp->t_session);
 2163         if (tp->t_session != NULL)
 2164             db_printf(" count %u leader %p tty %p sid %d login %s",
 2165                 tp->t_session->s_count, tp->t_session->s_leader,
 2166                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2167                 tp->t_session->s_login);
 2168         db_printf("\n");
 2169         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2170         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2171         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2172         db_printf("\tdev: %p\n", tp->t_dev);
 2173 }
 2174 
 2175 /* DDB command to list TTYs. */
 2176 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2177 {
 2178         struct tty *tp;
 2179         size_t isiz, osiz;
 2180         int i, j;
 2181 
 2182         /* Make the output look like `pstat -t'. */
 2183         db_printf("PTR        ");
 2184 #if defined(__LP64__)
 2185         db_printf("        ");
 2186 #endif
 2187         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2188             "COL  SESS  PGID STATE\n");
 2189 
 2190         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2191                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2192                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2193 
 2194                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
 2195                     tp,
 2196                     tty_devname(tp),
 2197                     isiz,
 2198                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2199                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2200                     isiz - tp->t_inlow,
 2201                     osiz,
 2202                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2203                     osiz - tp->t_outlow,
 2204                     MIN(tp->t_column, 99999),
 2205                     tp->t_session ? tp->t_session->s_sid : 0,
 2206                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2207 
 2208                 /* Flag bits. */
 2209                 for (i = j = 0; ttystates[i].flag; i++)
 2210                         if (tp->t_flags & ttystates[i].flag) {
 2211                                 db_printf("%c", ttystates[i].val);
 2212                                 j++;
 2213                         }
 2214                 if (j == 0)
 2215                         db_printf("-");
 2216                 db_printf("\n");
 2217         }
 2218 }
 2219 #endif /* DDB */
Cache object: 30733ace4082f8ef1e2183560363ae21
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FreeBSD/Linux Kernel Cross Reference sys/kern/tty.c

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