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/9.2/sys/kern/tty.c 242892 2012-11-11 12:12:44Z ed $");
   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 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         error = ttydisc_read(tp, uio, ioflag);
  437         tty_unlock(tp);
  438 
  439         /*
  440          * The read() call should not throw an error when the device is
  441          * being destroyed. Silently convert it to an EOF.
  442          */
  443 done:   if (error == ENXIO)
  444                 error = 0;
  445         return (error);
  446 }
  447 
  448 static int
  449 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
  450 {
  451         struct tty *tp = dev->si_drv1;
  452         int error;
  453 
  454         error = ttydev_enter(tp);
  455         if (error)
  456                 return (error);
  457 
  458         if (tp->t_termios.c_lflag & TOSTOP) {
  459                 error = tty_wait_background(tp, curthread, SIGTTOU);
  460                 if (error)
  461                         goto done;
  462         }
  463 
  464         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
  465                 /* Allow non-blocking writes to bypass serialization. */
  466                 error = ttydisc_write(tp, uio, ioflag);
  467         } else {
  468                 /* Serialize write() calls. */
  469                 while (tp->t_flags & TF_BUSY_OUT) {
  470                         error = tty_wait(tp, &tp->t_outserwait);
  471                         if (error)
  472                                 goto done;
  473                 }
  474 
  475                 tp->t_flags |= TF_BUSY_OUT;
  476                 error = ttydisc_write(tp, uio, ioflag);
  477                 tp->t_flags &= ~TF_BUSY_OUT;
  478                 cv_signal(&tp->t_outserwait);
  479         }
  480 
  481 done:   tty_unlock(tp);
  482         return (error);
  483 }
  484 
  485 static int
  486 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  487     struct thread *td)
  488 {
  489         struct tty *tp = dev->si_drv1;
  490         int error;
  491 
  492         error = ttydev_enter(tp);
  493         if (error)
  494                 return (error);
  495 
  496         switch (cmd) {
  497         case TIOCCBRK:
  498         case TIOCCONS:
  499         case TIOCDRAIN:
  500         case TIOCEXCL:
  501         case TIOCFLUSH:
  502         case TIOCNXCL:
  503         case TIOCSBRK:
  504         case TIOCSCTTY:
  505         case TIOCSETA:
  506         case TIOCSETAF:
  507         case TIOCSETAW:
  508         case TIOCSPGRP:
  509         case TIOCSTART:
  510         case TIOCSTAT:
  511         case TIOCSTI:
  512         case TIOCSTOP:
  513         case TIOCSWINSZ:
  514 #if 0
  515         case TIOCSDRAINWAIT:
  516         case TIOCSETD:
  517 #endif
  518 #ifdef COMPAT_43TTY
  519         case  TIOCLBIC:
  520         case  TIOCLBIS:
  521         case  TIOCLSET:
  522         case  TIOCSETC:
  523         case OTIOCSETD:
  524         case  TIOCSETN:
  525         case  TIOCSETP:
  526         case  TIOCSLTC:
  527 #endif /* COMPAT_43TTY */
  528                 /*
  529                  * If the ioctl() causes the TTY to be modified, let it
  530                  * wait in the background.
  531                  */
  532                 error = tty_wait_background(tp, curthread, SIGTTOU);
  533                 if (error)
  534                         goto done;
  535         }
  536 
  537         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
  538                 struct termios *old = &tp->t_termios;
  539                 struct termios *new = (struct termios *)data;
  540                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
  541                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
  542                 int cc;
  543 
  544                 /*
  545                  * Lock state devices.  Just overwrite the values of the
  546                  * commands that are currently in use.
  547                  */
  548                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
  549                     (new->c_iflag & ~lock->c_iflag);
  550                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
  551                     (new->c_oflag & ~lock->c_oflag);
  552                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
  553                     (new->c_cflag & ~lock->c_cflag);
  554                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
  555                     (new->c_lflag & ~lock->c_lflag);
  556                 for (cc = 0; cc < NCCS; ++cc)
  557                         if (lock->c_cc[cc])
  558                                 new->c_cc[cc] = old->c_cc[cc];
  559                 if (lock->c_ispeed)
  560                         new->c_ispeed = old->c_ispeed;
  561                 if (lock->c_ospeed)
  562                         new->c_ospeed = old->c_ospeed;
  563         }
  564 
  565         error = tty_ioctl(tp, cmd, data, fflag, td);
  566 done:   tty_unlock(tp);
  567 
  568         return (error);
  569 }
  570 
  571 static int
  572 ttydev_poll(struct cdev *dev, int events, struct thread *td)
  573 {
  574         struct tty *tp = dev->si_drv1;
  575         int error, revents = 0;
  576 
  577         error = ttydev_enter(tp);
  578         if (error)
  579                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
  580 
  581         if (events & (POLLIN|POLLRDNORM)) {
  582                 /* See if we can read something. */
  583                 if (ttydisc_read_poll(tp) > 0)
  584                         revents |= events & (POLLIN|POLLRDNORM);
  585         }
  586 
  587         if (tp->t_flags & TF_ZOMBIE) {
  588                 /* Hangup flag on zombie state. */
  589                 revents |= POLLHUP;
  590         } else if (events & (POLLOUT|POLLWRNORM)) {
  591                 /* See if we can write something. */
  592                 if (ttydisc_write_poll(tp) > 0)
  593                         revents |= events & (POLLOUT|POLLWRNORM);
  594         }
  595 
  596         if (revents == 0) {
  597                 if (events & (POLLIN|POLLRDNORM))
  598                         selrecord(td, &tp->t_inpoll);
  599                 if (events & (POLLOUT|POLLWRNORM))
  600                         selrecord(td, &tp->t_outpoll);
  601         }
  602 
  603         tty_unlock(tp);
  604 
  605         return (revents);
  606 }
  607 
  608 static int
  609 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  610     int nprot, vm_memattr_t *memattr)
  611 {
  612         struct tty *tp = dev->si_drv1;
  613         int error;
  614 
  615         /* Handle mmap() through the driver. */
  616 
  617         error = ttydev_enter(tp);
  618         if (error)
  619                 return (-1);
  620         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
  621         tty_unlock(tp);
  622 
  623         return (error);
  624 }
  625 
  626 /*
  627  * kqueue support.
  628  */
  629 
  630 static void
  631 tty_kqops_read_detach(struct knote *kn)
  632 {
  633         struct tty *tp = kn->kn_hook;
  634 
  635         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
  636 }
  637 
  638 static int
  639 tty_kqops_read_event(struct knote *kn, long hint)
  640 {
  641         struct tty *tp = kn->kn_hook;
  642 
  643         tty_lock_assert(tp, MA_OWNED);
  644 
  645         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
  646                 kn->kn_flags |= EV_EOF;
  647                 return (1);
  648         } else {
  649                 kn->kn_data = ttydisc_read_poll(tp);
  650                 return (kn->kn_data > 0);
  651         }
  652 }
  653 
  654 static void
  655 tty_kqops_write_detach(struct knote *kn)
  656 {
  657         struct tty *tp = kn->kn_hook;
  658 
  659         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
  660 }
  661 
  662 static int
  663 tty_kqops_write_event(struct knote *kn, long hint)
  664 {
  665         struct tty *tp = kn->kn_hook;
  666 
  667         tty_lock_assert(tp, MA_OWNED);
  668 
  669         if (tty_gone(tp)) {
  670                 kn->kn_flags |= EV_EOF;
  671                 return (1);
  672         } else {
  673                 kn->kn_data = ttydisc_write_poll(tp);
  674                 return (kn->kn_data > 0);
  675         }
  676 }
  677 
  678 static struct filterops tty_kqops_read = {
  679         .f_isfd = 1,
  680         .f_detach = tty_kqops_read_detach,
  681         .f_event = tty_kqops_read_event,
  682 };
  683 static struct filterops tty_kqops_write = {
  684         .f_isfd = 1,
  685         .f_detach = tty_kqops_write_detach,
  686         .f_event = tty_kqops_write_event,
  687 };
  688 
  689 static int
  690 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
  691 {
  692         struct tty *tp = dev->si_drv1;
  693         int error;
  694 
  695         error = ttydev_enter(tp);
  696         if (error)
  697                 return (error);
  698 
  699         switch (kn->kn_filter) {
  700         case EVFILT_READ:
  701                 kn->kn_hook = tp;
  702                 kn->kn_fop = &tty_kqops_read;
  703                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
  704                 break;
  705         case EVFILT_WRITE:
  706                 kn->kn_hook = tp;
  707                 kn->kn_fop = &tty_kqops_write;
  708                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
  709                 break;
  710         default:
  711                 error = EINVAL;
  712                 break;
  713         }
  714 
  715         tty_unlock(tp);
  716         return (error);
  717 }
  718 
  719 static struct cdevsw ttydev_cdevsw = {
  720         .d_version      = D_VERSION,
  721         .d_open         = ttydev_open,
  722         .d_close        = ttydev_close,
  723         .d_read         = ttydev_read,
  724         .d_write        = ttydev_write,
  725         .d_ioctl        = ttydev_ioctl,
  726         .d_kqfilter     = ttydev_kqfilter,
  727         .d_poll         = ttydev_poll,
  728         .d_mmap         = ttydev_mmap,
  729         .d_name         = "ttydev",
  730         .d_flags        = D_TTY,
  731 };
  732 
  733 /*
  734  * Init/lock-state devices
  735  */
  736 
  737 static int
  738 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  739 {
  740         struct tty *tp;
  741         int error = 0;
  742 
  743         while ((tp = dev->si_drv1) == NULL) {
  744                 error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
  745                 if (error != EWOULDBLOCK)
  746                         return (error);
  747         }
  748         tty_lock(tp);
  749         if (tty_gone(tp))
  750                 error = ENODEV;
  751         tty_unlock(tp);
  752 
  753         return (error);
  754 }
  755 
  756 static int
  757 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
  758 {
  759         return (0);
  760 }
  761 
  762 static int
  763 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
  764 {
  765         return (ENODEV);
  766 }
  767 
  768 static int
  769 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
  770     struct thread *td)
  771 {
  772         struct tty *tp = dev->si_drv1;
  773         int error;
  774 
  775         tty_lock(tp);
  776         if (tty_gone(tp)) {
  777                 error = ENODEV;
  778                 goto done;
  779         }
  780 
  781         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
  782         if (error != ENOIOCTL)
  783                 goto done;
  784         error = 0;
  785 
  786         switch (cmd) {
  787         case TIOCGETA:
  788                 /* Obtain terminal flags through tcgetattr(). */
  789                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
  790                 break;
  791         case TIOCSETA:
  792                 /* Set terminal flags through tcsetattr(). */
  793                 error = priv_check(td, PRIV_TTY_SETA);
  794                 if (error)
  795                         break;
  796                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
  797                 break;
  798         case TIOCGETD:
  799                 *(int *)data = TTYDISC;
  800                 break;
  801         case TIOCGWINSZ:
  802                 bzero(data, sizeof(struct winsize));
  803                 break;
  804         default:
  805                 error = ENOTTY;
  806         }
  807 
  808 done:   tty_unlock(tp);
  809         return (error);
  810 }
  811 
  812 static struct cdevsw ttyil_cdevsw = {
  813         .d_version      = D_VERSION,
  814         .d_open         = ttyil_open,
  815         .d_close        = ttyil_close,
  816         .d_read         = ttyil_rdwr,
  817         .d_write        = ttyil_rdwr,
  818         .d_ioctl        = ttyil_ioctl,
  819         .d_name         = "ttyil",
  820         .d_flags        = D_TTY,
  821 };
  822 
  823 static void
  824 tty_init_termios(struct tty *tp)
  825 {
  826         struct termios *t = &tp->t_termios_init_in;
  827 
  828         t->c_cflag = TTYDEF_CFLAG;
  829         t->c_iflag = TTYDEF_IFLAG;
  830         t->c_lflag = TTYDEF_LFLAG;
  831         t->c_oflag = TTYDEF_OFLAG;
  832         t->c_ispeed = TTYDEF_SPEED;
  833         t->c_ospeed = TTYDEF_SPEED;
  834         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
  835 
  836         tp->t_termios_init_out = *t;
  837 }
  838 
  839 void
  840 tty_init_console(struct tty *tp, speed_t s)
  841 {
  842         struct termios *ti = &tp->t_termios_init_in;
  843         struct termios *to = &tp->t_termios_init_out;
  844 
  845         if (s != 0) {
  846                 ti->c_ispeed = ti->c_ospeed = s;
  847                 to->c_ispeed = to->c_ospeed = s;
  848         }
  849 
  850         ti->c_cflag |= CLOCAL;
  851         to->c_cflag |= CLOCAL;
  852 }
  853 
  854 /*
  855  * Standard device routine implementations, mostly meant for
  856  * pseudo-terminal device drivers. When a driver creates a new terminal
  857  * device class, missing routines are patched.
  858  */
  859 
  860 static int
  861 ttydevsw_defopen(struct tty *tp)
  862 {
  863 
  864         return (0);
  865 }
  866 
  867 static void
  868 ttydevsw_defclose(struct tty *tp)
  869 {
  870 }
  871 
  872 static void
  873 ttydevsw_defoutwakeup(struct tty *tp)
  874 {
  875 
  876         panic("Terminal device has output, while not implemented");
  877 }
  878 
  879 static void
  880 ttydevsw_definwakeup(struct tty *tp)
  881 {
  882 }
  883 
  884 static int
  885 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
  886 {
  887 
  888         return (ENOIOCTL);
  889 }
  890 
  891 static int
  892 ttydevsw_defcioctl(struct tty *tp, int unit, u_long cmd, caddr_t data, struct thread *td)
  893 {
  894 
  895         return (ENOIOCTL);
  896 }
  897 
  898 static int
  899 ttydevsw_defparam(struct tty *tp, struct termios *t)
  900 {
  901 
  902         /*
  903          * Allow the baud rate to be adjusted for pseudo-devices, but at
  904          * least restrict it to 115200 to prevent excessive buffer
  905          * usage.  Also disallow 0, to prevent foot shooting.
  906          */
  907         if (t->c_ispeed < B50)
  908                 t->c_ispeed = B50;
  909         else if (t->c_ispeed > B115200)
  910                 t->c_ispeed = B115200;
  911         if (t->c_ospeed < B50)
  912                 t->c_ospeed = B50;
  913         else if (t->c_ospeed > B115200)
  914                 t->c_ospeed = B115200;
  915         t->c_cflag |= CREAD;
  916 
  917         return (0);
  918 }
  919 
  920 static int
  921 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
  922 {
  923 
  924         /* Simulate a carrier to make the TTY layer happy. */
  925         return (SER_DCD);
  926 }
  927 
  928 static int
  929 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
  930     int nprot, vm_memattr_t *memattr)
  931 {
  932 
  933         return (-1);
  934 }
  935 
  936 static void
  937 ttydevsw_defpktnotify(struct tty *tp, char event)
  938 {
  939 }
  940 
  941 static void
  942 ttydevsw_deffree(void *softc)
  943 {
  944 
  945         panic("Terminal device freed without a free-handler");
  946 }
  947 
  948 /*
  949  * TTY allocation and deallocation. TTY devices can be deallocated when
  950  * the driver doesn't use it anymore, when the TTY isn't a session's
  951  * controlling TTY and when the device node isn't opened through devfs.
  952  */
  953 
  954 struct tty *
  955 tty_alloc(struct ttydevsw *tsw, void *sc)
  956 {
  957 
  958         return (tty_alloc_mutex(tsw, sc, NULL));
  959 }
  960 
  961 struct tty *
  962 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
  963 {
  964         struct tty *tp;
  965 
  966         /* Make sure the driver defines all routines. */
  967 #define PATCH_FUNC(x) do {                              \
  968         if (tsw->tsw_ ## x == NULL)                     \
  969                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
  970 } while (0)
  971         PATCH_FUNC(open);
  972         PATCH_FUNC(close);
  973         PATCH_FUNC(outwakeup);
  974         PATCH_FUNC(inwakeup);
  975         PATCH_FUNC(ioctl);
  976         PATCH_FUNC(cioctl);
  977         PATCH_FUNC(param);
  978         PATCH_FUNC(modem);
  979         PATCH_FUNC(mmap);
  980         PATCH_FUNC(pktnotify);
  981         PATCH_FUNC(free);
  982 #undef PATCH_FUNC
  983 
  984         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
  985         tp->t_devsw = tsw;
  986         tp->t_devswsoftc = sc;
  987         tp->t_flags = tsw->tsw_flags;
  988 
  989         tty_init_termios(tp);
  990 
  991         cv_init(&tp->t_inwait, "ttyin");
  992         cv_init(&tp->t_outwait, "ttyout");
  993         cv_init(&tp->t_outserwait, "ttyosr");
  994         cv_init(&tp->t_bgwait, "ttybg");
  995         cv_init(&tp->t_dcdwait, "ttydcd");
  996 
  997         /* Allow drivers to use a custom mutex to lock the TTY. */
  998         if (mutex != NULL) {
  999                 tp->t_mtx = mutex;
 1000         } else {
 1001                 tp->t_mtx = &tp->t_mtxobj;
 1002                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
 1003         }
 1004 
 1005         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
 1006         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
 1007 
 1008         sx_xlock(&tty_list_sx);
 1009         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
 1010         tty_list_count++;
 1011         sx_xunlock(&tty_list_sx);
 1012 
 1013         return (tp);
 1014 }
 1015 
 1016 static void
 1017 tty_dealloc(void *arg)
 1018 {
 1019         struct tty *tp = arg;
 1020 
 1021         sx_xlock(&tty_list_sx);
 1022         TAILQ_REMOVE(&tty_list, tp, t_list);
 1023         tty_list_count--;
 1024         sx_xunlock(&tty_list_sx);
 1025 
 1026         /* Make sure we haven't leaked buffers. */
 1027         MPASS(ttyinq_getsize(&tp->t_inq) == 0);
 1028         MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
 1029 
 1030         seldrain(&tp->t_inpoll);
 1031         seldrain(&tp->t_outpoll);
 1032         knlist_destroy(&tp->t_inpoll.si_note);
 1033         knlist_destroy(&tp->t_outpoll.si_note);
 1034 
 1035         cv_destroy(&tp->t_inwait);
 1036         cv_destroy(&tp->t_outwait);
 1037         cv_destroy(&tp->t_bgwait);
 1038         cv_destroy(&tp->t_dcdwait);
 1039         cv_destroy(&tp->t_outserwait);
 1040 
 1041         if (tp->t_mtx == &tp->t_mtxobj)
 1042                 mtx_destroy(&tp->t_mtxobj);
 1043         ttydevsw_free(tp);
 1044         free(tp, M_TTY);
 1045 }
 1046 
 1047 static void
 1048 tty_rel_free(struct tty *tp)
 1049 {
 1050         struct cdev *dev;
 1051 
 1052         tty_lock_assert(tp, MA_OWNED);
 1053 
 1054 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
 1055         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
 1056                 /* TTY is still in use. */
 1057                 tty_unlock(tp);
 1058                 return;
 1059         }
 1060 
 1061         /* TTY can be deallocated. */
 1062         dev = tp->t_dev;
 1063         tp->t_dev = NULL;
 1064         tty_unlock(tp);
 1065 
 1066         if (dev != NULL)
 1067                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
 1068 }
 1069 
 1070 void
 1071 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
 1072 {
 1073         MPASS(tp->t_sessioncnt > 0);
 1074         tty_lock_assert(tp, MA_OWNED);
 1075 
 1076         if (tp->t_pgrp == pg)
 1077                 tp->t_pgrp = NULL;
 1078 
 1079         tty_unlock(tp);
 1080 }
 1081 
 1082 void
 1083 tty_rel_sess(struct tty *tp, struct session *sess)
 1084 {
 1085         MPASS(tp->t_sessioncnt > 0);
 1086 
 1087         /* Current session has left. */
 1088         if (tp->t_session == sess) {
 1089                 tp->t_session = NULL;
 1090                 MPASS(tp->t_pgrp == NULL);
 1091         }
 1092         tp->t_sessioncnt--;
 1093         tty_rel_free(tp);
 1094 }
 1095 
 1096 void
 1097 tty_rel_gone(struct tty *tp)
 1098 {
 1099         MPASS(!tty_gone(tp));
 1100 
 1101         /* Simulate carrier removal. */
 1102         ttydisc_modem(tp, 0);
 1103 
 1104         /* Wake up all blocked threads. */
 1105         tty_wakeup(tp, FREAD|FWRITE);
 1106         cv_broadcast(&tp->t_bgwait);
 1107         cv_broadcast(&tp->t_dcdwait);
 1108 
 1109         tp->t_flags |= TF_GONE;
 1110         tty_rel_free(tp);
 1111 }
 1112 
 1113 /*
 1114  * Exposing information about current TTY's through sysctl
 1115  */
 1116 
 1117 static void
 1118 tty_to_xtty(struct tty *tp, struct xtty *xt)
 1119 {
 1120         tty_lock_assert(tp, MA_OWNED);
 1121 
 1122         xt->xt_size = sizeof(struct xtty);
 1123         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
 1124         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
 1125         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
 1126         xt->xt_inlow = tp->t_inlow;
 1127         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
 1128         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
 1129         xt->xt_outlow = tp->t_outlow;
 1130         xt->xt_column = tp->t_column;
 1131         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 1132         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
 1133         xt->xt_flags = tp->t_flags;
 1134         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
 1135 }
 1136 
 1137 static int
 1138 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
 1139 {
 1140         unsigned long lsize;
 1141         struct xtty *xtlist, *xt;
 1142         struct tty *tp;
 1143         int error;
 1144 
 1145         sx_slock(&tty_list_sx);
 1146         lsize = tty_list_count * sizeof(struct xtty);
 1147         if (lsize == 0) {
 1148                 sx_sunlock(&tty_list_sx);
 1149                 return (0);
 1150         }
 1151 
 1152         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
 1153 
 1154         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1155                 tty_lock(tp);
 1156                 tty_to_xtty(tp, xt);
 1157                 tty_unlock(tp);
 1158                 xt++;
 1159         }
 1160         sx_sunlock(&tty_list_sx);
 1161 
 1162         error = SYSCTL_OUT(req, xtlist, lsize);
 1163         free(xtlist, M_TTY);
 1164         return (error);
 1165 }
 1166 
 1167 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 1168         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
 1169 
 1170 /*
 1171  * Device node creation. Device has been set up, now we can expose it to
 1172  * the user.
 1173  */
 1174 
 1175 void
 1176 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
 1177 {
 1178         va_list ap;
 1179         struct cdev *dev;
 1180         const char *prefix = "tty";
 1181         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
 1182         uid_t uid;
 1183         gid_t gid;
 1184         mode_t mode;
 1185 
 1186         /* Remove "tty" prefix from devices like PTY's. */
 1187         if (tp->t_flags & TF_NOPREFIX)
 1188                 prefix = "";
 1189 
 1190         va_start(ap, fmt);
 1191         vsnrprintf(name, sizeof name, 32, fmt, ap);
 1192         va_end(ap);
 1193 
 1194         if (cred == NULL) {
 1195                 /* System device. */
 1196                 uid = UID_ROOT;
 1197                 gid = GID_WHEEL;
 1198                 mode = S_IRUSR|S_IWUSR;
 1199         } else {
 1200                 /* User device. */
 1201                 uid = cred->cr_ruid;
 1202                 gid = GID_TTY;
 1203                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
 1204         }
 1205 
 1206         /* Master call-in device. */
 1207         dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
 1208             uid, gid, mode, "%s%s", prefix, name);
 1209         dev->si_drv1 = tp;
 1210         wakeup(&dev->si_drv1);
 1211         tp->t_dev = dev;
 1212 
 1213         /* Slave call-in devices. */
 1214         if (tp->t_flags & TF_INITLOCK) {
 1215                 dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_INIT, cred,
 1216                     uid, gid, mode, "%s%s.init", prefix, name);
 1217                 dev_depends(tp->t_dev, dev);
 1218                 dev->si_drv1 = tp;
 1219                 wakeup(&dev->si_drv1);
 1220                 dev->si_drv2 = &tp->t_termios_init_in;
 1221 
 1222                 dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_LOCK, cred,
 1223                     uid, gid, mode, "%s%s.lock", 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_lock_in;
 1228         }
 1229 
 1230         /* Call-out devices. */
 1231         if (tp->t_flags & TF_CALLOUT) {
 1232                 dev = make_dev_cred(&ttydev_cdevsw, TTYUNIT_CALLOUT, cred,
 1233                     UID_UUCP, GID_DIALER, 0660, "cua%s", name);
 1234                 dev_depends(tp->t_dev, dev);
 1235                 dev->si_drv1 = tp;
 1236                 wakeup(&dev->si_drv1);
 1237 
 1238                 /* Slave call-out devices. */
 1239                 if (tp->t_flags & TF_INITLOCK) {
 1240                         dev = make_dev_cred(&ttyil_cdevsw, 
 1241                             TTYUNIT_CALLOUT | TTYUNIT_INIT, cred,
 1242                             UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
 1243                         dev_depends(tp->t_dev, dev);
 1244                         dev->si_drv1 = tp;
 1245                         wakeup(&dev->si_drv1);
 1246                         dev->si_drv2 = &tp->t_termios_init_out;
 1247 
 1248                         dev = make_dev_cred(&ttyil_cdevsw,
 1249                             TTYUNIT_CALLOUT | TTYUNIT_LOCK, cred,
 1250                             UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
 1251                         dev_depends(tp->t_dev, dev);
 1252                         dev->si_drv1 = tp;
 1253                         wakeup(&dev->si_drv1);
 1254                         dev->si_drv2 = &tp->t_termios_lock_out;
 1255                 }
 1256         }
 1257 }
 1258 
 1259 /*
 1260  * Signalling processes.
 1261  */
 1262 
 1263 void
 1264 tty_signal_sessleader(struct tty *tp, int sig)
 1265 {
 1266         struct proc *p;
 1267 
 1268         tty_lock_assert(tp, MA_OWNED);
 1269         MPASS(sig >= 1 && sig < NSIG);
 1270 
 1271         /* Make signals start output again. */
 1272         tp->t_flags &= ~TF_STOPPED;
 1273 
 1274         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
 1275                 p = tp->t_session->s_leader;
 1276                 PROC_LOCK(p);
 1277                 kern_psignal(p, sig);
 1278                 PROC_UNLOCK(p);
 1279         }
 1280 }
 1281 
 1282 void
 1283 tty_signal_pgrp(struct tty *tp, int sig)
 1284 {
 1285         ksiginfo_t ksi;
 1286 
 1287         tty_lock_assert(tp, MA_OWNED);
 1288         MPASS(sig >= 1 && sig < NSIG);
 1289 
 1290         /* Make signals start output again. */
 1291         tp->t_flags &= ~TF_STOPPED;
 1292 
 1293         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
 1294                 tty_info(tp);
 1295         if (tp->t_pgrp != NULL) {
 1296                 ksiginfo_init(&ksi);
 1297                 ksi.ksi_signo = sig;
 1298                 ksi.ksi_code = SI_KERNEL;
 1299                 PGRP_LOCK(tp->t_pgrp);
 1300                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
 1301                 PGRP_UNLOCK(tp->t_pgrp);
 1302         }
 1303 }
 1304 
 1305 void
 1306 tty_wakeup(struct tty *tp, int flags)
 1307 {
 1308         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
 1309                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 1310 
 1311         if (flags & FWRITE) {
 1312                 cv_broadcast(&tp->t_outwait);
 1313                 selwakeup(&tp->t_outpoll);
 1314                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
 1315         }
 1316         if (flags & FREAD) {
 1317                 cv_broadcast(&tp->t_inwait);
 1318                 selwakeup(&tp->t_inpoll);
 1319                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
 1320         }
 1321 }
 1322 
 1323 int
 1324 tty_wait(struct tty *tp, struct cv *cv)
 1325 {
 1326         int error;
 1327         int revokecnt = tp->t_revokecnt;
 1328 
 1329         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1330         MPASS(!tty_gone(tp));
 1331 
 1332         error = cv_wait_sig(cv, tp->t_mtx);
 1333 
 1334         /* Restart the system call when we may have been revoked. */
 1335         if (tp->t_revokecnt != revokecnt)
 1336                 return (ERESTART);
 1337 
 1338         /* Bail out when the device slipped away. */
 1339         if (tty_gone(tp))
 1340                 return (ENXIO);
 1341 
 1342         return (error);
 1343 }
 1344 
 1345 int
 1346 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
 1347 {
 1348         int error;
 1349         int revokecnt = tp->t_revokecnt;
 1350 
 1351         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
 1352         MPASS(!tty_gone(tp));
 1353 
 1354         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
 1355 
 1356         /* Restart the system call when we may have been revoked. */
 1357         if (tp->t_revokecnt != revokecnt)
 1358                 return (ERESTART);
 1359 
 1360         /* Bail out when the device slipped away. */
 1361         if (tty_gone(tp))
 1362                 return (ENXIO);
 1363 
 1364         return (error);
 1365 }
 1366 
 1367 void
 1368 tty_flush(struct tty *tp, int flags)
 1369 {
 1370         if (flags & FWRITE) {
 1371                 tp->t_flags &= ~TF_HIWAT_OUT;
 1372                 ttyoutq_flush(&tp->t_outq);
 1373                 tty_wakeup(tp, FWRITE);
 1374                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
 1375         }
 1376         if (flags & FREAD) {
 1377                 tty_hiwat_in_unblock(tp);
 1378                 ttyinq_flush(&tp->t_inq);
 1379                 ttydevsw_inwakeup(tp);
 1380                 ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
 1381         }
 1382 }
 1383 
 1384 static int
 1385 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
 1386     struct thread *td)
 1387 {
 1388         int error;
 1389 
 1390         switch (cmd) {
 1391         /*
 1392          * Modem commands.
 1393          * The SER_* and TIOCM_* flags are the same, but one bit
 1394          * shifted. I don't know why.
 1395          */
 1396         case TIOCSDTR:
 1397                 ttydevsw_modem(tp, SER_DTR, 0);
 1398                 return (0);
 1399         case TIOCCDTR:
 1400                 ttydevsw_modem(tp, 0, SER_DTR);
 1401                 return (0);
 1402         case TIOCMSET: {
 1403                 int bits = *(int *)data;
 1404                 ttydevsw_modem(tp,
 1405                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
 1406                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1407                 return (0);
 1408         }
 1409         case TIOCMBIS: {
 1410                 int bits = *(int *)data;
 1411                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
 1412                 return (0);
 1413         }
 1414         case TIOCMBIC: {
 1415                 int bits = *(int *)data;
 1416                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
 1417                 return (0);
 1418         }
 1419         case TIOCMGET:
 1420                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
 1421                 return (0);
 1422 
 1423         case FIOASYNC:
 1424                 if (*(int *)data)
 1425                         tp->t_flags |= TF_ASYNC;
 1426                 else
 1427                         tp->t_flags &= ~TF_ASYNC;
 1428                 return (0);
 1429         case FIONBIO:
 1430                 /* This device supports non-blocking operation. */
 1431                 return (0);
 1432         case FIONREAD:
 1433                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
 1434                 return (0);
 1435         case FIONWRITE:
 1436         case TIOCOUTQ:
 1437                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
 1438                 return (0);
 1439         case FIOSETOWN:
 1440                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1441                         /* Not allowed to set ownership. */
 1442                         return (ENOTTY);
 1443 
 1444                 /* Temporarily unlock the TTY to set ownership. */
 1445                 tty_unlock(tp);
 1446                 error = fsetown(*(int *)data, &tp->t_sigio);
 1447                 tty_lock(tp);
 1448                 return (error);
 1449         case FIOGETOWN:
 1450                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
 1451                         /* Not allowed to set ownership. */
 1452                         return (ENOTTY);
 1453 
 1454                 /* Get ownership. */
 1455                 *(int *)data = fgetown(&tp->t_sigio);
 1456                 return (0);
 1457         case TIOCGETA:
 1458                 /* Obtain terminal flags through tcgetattr(). */
 1459                 *(struct termios*)data = tp->t_termios;
 1460                 return (0);
 1461         case TIOCSETA:
 1462         case TIOCSETAW:
 1463         case TIOCSETAF: {
 1464                 struct termios *t = data;
 1465 
 1466                 /*
 1467                  * Who makes up these funny rules? According to POSIX,
 1468                  * input baud rate is set equal to the output baud rate
 1469                  * when zero.
 1470                  */
 1471                 if (t->c_ispeed == 0)
 1472                         t->c_ispeed = t->c_ospeed;
 1473 
 1474                 /* Discard any unsupported bits. */
 1475                 t->c_iflag &= TTYSUP_IFLAG;
 1476                 t->c_oflag &= TTYSUP_OFLAG;
 1477                 t->c_lflag &= TTYSUP_LFLAG;
 1478                 t->c_cflag &= TTYSUP_CFLAG;
 1479 
 1480                 /* Set terminal flags through tcsetattr(). */
 1481                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 1482                         error = tty_drain(tp);
 1483                         if (error)
 1484                                 return (error);
 1485                         if (cmd == TIOCSETAF)
 1486                                 tty_flush(tp, FREAD);
 1487                 }
 1488 
 1489                 /*
 1490                  * Only call param() when the flags really change.
 1491                  */
 1492                 if ((t->c_cflag & CIGNORE) == 0 &&
 1493                     (tp->t_termios.c_cflag != t->c_cflag ||
 1494                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
 1495                     (IXON|IXOFF|IXANY)) ||
 1496                     tp->t_termios.c_ispeed != t->c_ispeed ||
 1497                     tp->t_termios.c_ospeed != t->c_ospeed)) {
 1498                         error = ttydevsw_param(tp, t);
 1499                         if (error)
 1500                                 return (error);
 1501 
 1502                         /* XXX: CLOCAL? */
 1503 
 1504                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
 1505                         tp->t_termios.c_ispeed = t->c_ispeed;
 1506                         tp->t_termios.c_ospeed = t->c_ospeed;
 1507 
 1508                         /* Baud rate has changed - update watermarks. */
 1509                         tty_watermarks(tp);
 1510                 }
 1511 
 1512                 /* Copy new non-device driver parameters. */
 1513                 tp->t_termios.c_iflag = t->c_iflag;
 1514                 tp->t_termios.c_oflag = t->c_oflag;
 1515                 tp->t_termios.c_lflag = t->c_lflag;
 1516                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
 1517 
 1518                 ttydisc_optimize(tp);
 1519 
 1520                 if ((t->c_lflag & ICANON) == 0) {
 1521                         /*
 1522                          * When in non-canonical mode, wake up all
 1523                          * readers. Canonicalize any partial input. VMIN
 1524                          * and VTIME could also be adjusted.
 1525                          */
 1526                         ttyinq_canonicalize(&tp->t_inq);
 1527                         tty_wakeup(tp, FREAD);
 1528                 }
 1529 
 1530                 /*
 1531                  * For packet mode: notify the PTY consumer that VSTOP
 1532                  * and VSTART may have been changed.
 1533                  */
 1534                 if (tp->t_termios.c_iflag & IXON &&
 1535                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
 1536                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
 1537                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
 1538                 else
 1539                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
 1540                 return (0);
 1541         }
 1542         case TIOCGETD:
 1543                 /* For compatibility - we only support TTYDISC. */
 1544                 *(int *)data = TTYDISC;
 1545                 return (0);
 1546         case TIOCGPGRP:
 1547                 if (!tty_is_ctty(tp, td->td_proc))
 1548                         return (ENOTTY);
 1549 
 1550                 if (tp->t_pgrp != NULL)
 1551                         *(int *)data = tp->t_pgrp->pg_id;
 1552                 else
 1553                         *(int *)data = NO_PID;
 1554                 return (0);
 1555         case TIOCGSID:
 1556                 if (!tty_is_ctty(tp, td->td_proc))
 1557                         return (ENOTTY);
 1558 
 1559                 MPASS(tp->t_session);
 1560                 *(int *)data = tp->t_session->s_sid;
 1561                 return (0);
 1562         case TIOCSCTTY: {
 1563                 struct proc *p = td->td_proc;
 1564 
 1565                 /* XXX: This looks awful. */
 1566                 tty_unlock(tp);
 1567                 sx_xlock(&proctree_lock);
 1568                 tty_lock(tp);
 1569 
 1570                 if (!SESS_LEADER(p)) {
 1571                         /* Only the session leader may do this. */
 1572                         sx_xunlock(&proctree_lock);
 1573                         return (EPERM);
 1574                 }
 1575 
 1576                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
 1577                         /* This is already our controlling TTY. */
 1578                         sx_xunlock(&proctree_lock);
 1579                         return (0);
 1580                 }
 1581 
 1582                 if (p->p_session->s_ttyp != NULL ||
 1583                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
 1584                     tp->t_session->s_ttyvp->v_type != VBAD)) {
 1585                         /*
 1586                          * There is already a relation between a TTY and
 1587                          * a session, or the caller is not the session
 1588                          * leader.
 1589                          *
 1590                          * Allow the TTY to be stolen when the vnode is
 1591                          * invalid, but the reference to the TTY is
 1592                          * still active.  This allows immediate reuse of
 1593                          * TTYs of which the session leader has been
 1594                          * killed or the TTY revoked.
 1595                          */
 1596                         sx_xunlock(&proctree_lock);
 1597                         return (EPERM);
 1598                 }
 1599 
 1600                 /* Connect the session to the TTY. */
 1601                 tp->t_session = p->p_session;
 1602                 tp->t_session->s_ttyp = tp;
 1603                 tp->t_sessioncnt++;
 1604                 sx_xunlock(&proctree_lock);
 1605 
 1606                 /* Assign foreground process group. */
 1607                 tp->t_pgrp = p->p_pgrp;
 1608                 PROC_LOCK(p);
 1609                 p->p_flag |= P_CONTROLT;
 1610                 PROC_UNLOCK(p);
 1611 
 1612                 return (0);
 1613         }
 1614         case TIOCSPGRP: {
 1615                 struct pgrp *pg;
 1616 
 1617                 /*
 1618                  * XXX: Temporarily unlock the TTY to locate the process
 1619                  * group. This code would be lot nicer if we would ever
 1620                  * decompose proctree_lock.
 1621                  */
 1622                 tty_unlock(tp);
 1623                 sx_slock(&proctree_lock);
 1624                 pg = pgfind(*(int *)data);
 1625                 if (pg != NULL)
 1626                         PGRP_UNLOCK(pg);
 1627                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
 1628                         sx_sunlock(&proctree_lock);
 1629                         tty_lock(tp);
 1630                         return (EPERM);
 1631                 }
 1632                 tty_lock(tp);
 1633 
 1634                 /*
 1635                  * Determine if this TTY is the controlling TTY after
 1636                  * relocking the TTY.
 1637                  */
 1638                 if (!tty_is_ctty(tp, td->td_proc)) {
 1639                         sx_sunlock(&proctree_lock);
 1640                         return (ENOTTY);
 1641                 }
 1642                 tp->t_pgrp = pg;
 1643                 sx_sunlock(&proctree_lock);
 1644 
 1645                 /* Wake up the background process groups. */
 1646                 cv_broadcast(&tp->t_bgwait);
 1647                 return (0);
 1648         }
 1649         case TIOCFLUSH: {
 1650                 int flags = *(int *)data;
 1651 
 1652                 if (flags == 0)
 1653                         flags = (FREAD|FWRITE);
 1654                 else
 1655                         flags &= (FREAD|FWRITE);
 1656                 tty_flush(tp, flags);
 1657                 return (0);
 1658         }
 1659         case TIOCDRAIN:
 1660                 /* Drain TTY output. */
 1661                 return tty_drain(tp);
 1662         case TIOCCONS:
 1663                 /* Set terminal as console TTY. */
 1664                 if (*(int *)data) {
 1665                         error = priv_check(td, PRIV_TTY_CONSOLE);
 1666                         if (error)
 1667                                 return (error);
 1668 
 1669                         /*
 1670                          * XXX: constty should really need to be locked!
 1671                          * XXX: allow disconnected constty's to be stolen!
 1672                          */
 1673 
 1674                         if (constty == tp)
 1675                                 return (0);
 1676                         if (constty != NULL)
 1677                                 return (EBUSY);
 1678 
 1679                         tty_unlock(tp);
 1680                         constty_set(tp);
 1681                         tty_lock(tp);
 1682                 } else if (constty == tp) {
 1683                         constty_clear();
 1684                 }
 1685                 return (0);
 1686         case TIOCGWINSZ:
 1687                 /* Obtain window size. */
 1688                 *(struct winsize*)data = tp->t_winsize;
 1689                 return (0);
 1690         case TIOCSWINSZ:
 1691                 /* Set window size. */
 1692                 if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
 1693                         return (0);
 1694                 tp->t_winsize = *(struct winsize*)data;
 1695                 tty_signal_pgrp(tp, SIGWINCH);
 1696                 return (0);
 1697         case TIOCEXCL:
 1698                 tp->t_flags |= TF_EXCLUDE;
 1699                 return (0);
 1700         case TIOCNXCL:
 1701                 tp->t_flags &= ~TF_EXCLUDE;
 1702                 return (0);
 1703         case TIOCSTOP:
 1704                 tp->t_flags |= TF_STOPPED;
 1705                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
 1706                 return (0);
 1707         case TIOCSTART:
 1708                 tp->t_flags &= ~TF_STOPPED;
 1709                 ttydevsw_outwakeup(tp);
 1710                 ttydevsw_pktnotify(tp, TIOCPKT_START);
 1711                 return (0);
 1712         case TIOCSTAT:
 1713                 tty_info(tp);
 1714                 return (0);
 1715         case TIOCSTI:
 1716                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
 1717                         return (EPERM);
 1718                 if (!tty_is_ctty(tp, td->td_proc) &&
 1719                     priv_check(td, PRIV_TTY_STI))
 1720                         return (EACCES);
 1721                 ttydisc_rint(tp, *(char *)data, 0);
 1722                 ttydisc_rint_done(tp);
 1723                 return (0);
 1724         }
 1725 
 1726 #ifdef COMPAT_43TTY
 1727         return tty_ioctl_compat(tp, cmd, data, fflag, td);
 1728 #else /* !COMPAT_43TTY */
 1729         return (ENOIOCTL);
 1730 #endif /* COMPAT_43TTY */
 1731 }
 1732 
 1733 int
 1734 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
 1735 {
 1736         int error;
 1737 
 1738         tty_lock_assert(tp, MA_OWNED);
 1739 
 1740         if (tty_gone(tp))
 1741                 return (ENXIO);
 1742 
 1743         error = ttydevsw_ioctl(tp, cmd, data, td);
 1744         if (error == ENOIOCTL)
 1745                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
 1746 
 1747         return (error);
 1748 }
 1749 
 1750 dev_t
 1751 tty_udev(struct tty *tp)
 1752 {
 1753         if (tp->t_dev)
 1754                 return dev2udev(tp->t_dev);
 1755         else
 1756                 return NODEV;
 1757 }
 1758 
 1759 int
 1760 tty_checkoutq(struct tty *tp)
 1761 {
 1762 
 1763         /* 256 bytes should be enough to print a log message. */
 1764         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
 1765 }
 1766 
 1767 void
 1768 tty_hiwat_in_block(struct tty *tp)
 1769 {
 1770 
 1771         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
 1772             tp->t_termios.c_iflag & IXOFF &&
 1773             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
 1774                 /*
 1775                  * Input flow control. Only enter the high watermark when we
 1776                  * can successfully store the VSTOP character.
 1777                  */
 1778                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1779                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
 1780                         tp->t_flags |= TF_HIWAT_IN;
 1781         } else {
 1782                 /* No input flow control. */
 1783                 tp->t_flags |= TF_HIWAT_IN;
 1784         }
 1785 }
 1786 
 1787 void
 1788 tty_hiwat_in_unblock(struct tty *tp)
 1789 {
 1790 
 1791         if (tp->t_flags & TF_HIWAT_IN &&
 1792             tp->t_termios.c_iflag & IXOFF &&
 1793             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
 1794                 /*
 1795                  * Input flow control. Only leave the high watermark when we
 1796                  * can successfully store the VSTART character.
 1797                  */
 1798                 if (ttyoutq_write_nofrag(&tp->t_outq,
 1799                     &tp->t_termios.c_cc[VSTART], 1) == 0)
 1800                         tp->t_flags &= ~TF_HIWAT_IN;
 1801         } else {
 1802                 /* No input flow control. */
 1803                 tp->t_flags &= ~TF_HIWAT_IN;
 1804         }
 1805 
 1806         if (!tty_gone(tp))
 1807                 ttydevsw_inwakeup(tp);
 1808 }
 1809 
 1810 /*
 1811  * TTY hooks interface.
 1812  */
 1813 
 1814 static int
 1815 ttyhook_defrint(struct tty *tp, char c, int flags)
 1816 {
 1817 
 1818         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
 1819                 return (-1);
 1820 
 1821         return (0);
 1822 }
 1823 
 1824 int
 1825 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
 1826     struct ttyhook *th, void *softc)
 1827 {
 1828         struct tty *tp;
 1829         struct file *fp;
 1830 #ifdef CAPABILITIES
 1831         struct file *fp_cap;
 1832 #endif
 1833         struct cdev *dev;
 1834         struct cdevsw *cdp;
 1835         struct filedesc *fdp;
 1836         int error, ref;
 1837 
 1838         /* Validate the file descriptor. */
 1839         if ((fdp = p->p_fd) == NULL)
 1840                 return (EBADF);
 1841 
 1842         fp = fget_unlocked(fdp, fd);
 1843         if (fp == NULL)
 1844                 return (EBADF);
 1845         if (fp->f_ops == &badfileops) {
 1846                 error = EBADF;
 1847                 goto done1;
 1848         }
 1849 
 1850 #ifdef CAPABILITIES
 1851         fp_cap = fp;
 1852         error = cap_funwrap(fp_cap, CAP_TTYHOOK, &fp);
 1853         if (error)
 1854                 return (error);
 1855 #endif
 1856 
 1857         /*
 1858          * Make sure the vnode is bound to a character device.
 1859          * Unlocked check for the vnode type is ok there, because we
 1860          * only shall prevent calling devvn_refthread on the file that
 1861          * never has been opened over a character device.
 1862          */
 1863         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
 1864                 error = EINVAL;
 1865                 goto done1;
 1866         }
 1867 
 1868         /* Make sure it is a TTY. */
 1869         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
 1870         if (cdp == NULL) {
 1871                 error = ENXIO;
 1872                 goto done1;
 1873         }
 1874         if (dev != fp->f_data) {
 1875                 error = ENXIO;
 1876                 goto done2;
 1877         }
 1878         if (cdp != &ttydev_cdevsw) {
 1879                 error = ENOTTY;
 1880                 goto done2;
 1881         }
 1882         tp = dev->si_drv1;
 1883 
 1884         /* Try to attach the hook to the TTY. */
 1885         error = EBUSY;
 1886         tty_lock(tp);
 1887         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
 1888         if (tp->t_flags & TF_HOOK)
 1889                 goto done3;
 1890 
 1891         tp->t_flags |= TF_HOOK;
 1892         tp->t_hook = th;
 1893         tp->t_hooksoftc = softc;
 1894         *rtp = tp;
 1895         error = 0;
 1896 
 1897         /* Maybe we can switch into bypass mode now. */
 1898         ttydisc_optimize(tp);
 1899 
 1900         /* Silently convert rint() calls to rint_bypass() when possible. */
 1901         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
 1902                 th->th_rint = ttyhook_defrint;
 1903 
 1904 done3:  tty_unlock(tp);
 1905 done2:  dev_relthread(dev, ref);
 1906 done1:  fdrop(fp, curthread);
 1907         return (error);
 1908 }
 1909 
 1910 void
 1911 ttyhook_unregister(struct tty *tp)
 1912 {
 1913 
 1914         tty_lock_assert(tp, MA_OWNED);
 1915         MPASS(tp->t_flags & TF_HOOK);
 1916 
 1917         /* Disconnect the hook. */
 1918         tp->t_flags &= ~TF_HOOK;
 1919         tp->t_hook = NULL;
 1920 
 1921         /* Maybe we need to leave bypass mode. */
 1922         ttydisc_optimize(tp);
 1923 
 1924         /* Maybe deallocate the TTY as well. */
 1925         tty_rel_free(tp);
 1926 }
 1927 
 1928 /*
 1929  * /dev/console handling.
 1930  */
 1931 
 1932 static int
 1933 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
 1934 {
 1935         struct tty *tp;
 1936 
 1937         /* System has no console device. */
 1938         if (dev_console_filename == NULL)
 1939                 return (ENXIO);
 1940 
 1941         /* Look up corresponding TTY by device name. */
 1942         sx_slock(&tty_list_sx);
 1943         TAILQ_FOREACH(tp, &tty_list, t_list) {
 1944                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
 1945                         dev_console->si_drv1 = tp;
 1946                         break;
 1947                 }
 1948         }
 1949         sx_sunlock(&tty_list_sx);
 1950 
 1951         /* System console has no TTY associated. */
 1952         if (dev_console->si_drv1 == NULL)
 1953                 return (ENXIO);
 1954 
 1955         return (ttydev_open(dev, oflags, devtype, td));
 1956 }
 1957 
 1958 static int
 1959 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
 1960 {
 1961 
 1962         log_console(uio);
 1963 
 1964         return (ttydev_write(dev, uio, ioflag));
 1965 }
 1966 
 1967 /*
 1968  * /dev/console is a little different than normal TTY's.  When opened,
 1969  * it determines which TTY to use.  When data gets written to it, it
 1970  * will be logged in the kernel message buffer.
 1971  */
 1972 static struct cdevsw ttyconsdev_cdevsw = {
 1973         .d_version      = D_VERSION,
 1974         .d_open         = ttyconsdev_open,
 1975         .d_close        = ttydev_close,
 1976         .d_read         = ttydev_read,
 1977         .d_write        = ttyconsdev_write,
 1978         .d_ioctl        = ttydev_ioctl,
 1979         .d_kqfilter     = ttydev_kqfilter,
 1980         .d_poll         = ttydev_poll,
 1981         .d_mmap         = ttydev_mmap,
 1982         .d_name         = "ttyconsdev",
 1983         .d_flags        = D_TTY,
 1984 };
 1985 
 1986 static void
 1987 ttyconsdev_init(void *unused)
 1988 {
 1989 
 1990         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
 1991             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
 1992 }
 1993 
 1994 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
 1995 
 1996 void
 1997 ttyconsdev_select(const char *name)
 1998 {
 1999 
 2000         dev_console_filename = name;
 2001 }
 2002 
 2003 /*
 2004  * Debugging routines.
 2005  */
 2006 
 2007 #include "opt_ddb.h"
 2008 #ifdef DDB
 2009 #include <ddb/ddb.h>
 2010 #include <ddb/db_sym.h>
 2011 
 2012 static struct {
 2013         int flag;
 2014         char val;
 2015 } ttystates[] = {
 2016 #if 0
 2017         { TF_NOPREFIX,          'N' },
 2018 #endif
 2019         { TF_INITLOCK,          'I' },
 2020         { TF_CALLOUT,           'C' },
 2021 
 2022         /* Keep these together -> 'Oi' and 'Oo'. */
 2023         { TF_OPENED,            'O' },
 2024         { TF_OPENED_IN,         'i' },
 2025         { TF_OPENED_OUT,        'o' },
 2026         { TF_OPENED_CONS,       'c' },
 2027 
 2028         { TF_GONE,              'G' },
 2029         { TF_OPENCLOSE,         'B' },
 2030         { TF_ASYNC,             'Y' },
 2031         { TF_LITERAL,           'L' },
 2032 
 2033         /* Keep these together -> 'Hi' and 'Ho'. */
 2034         { TF_HIWAT,             'H' },
 2035         { TF_HIWAT_IN,          'i' },
 2036         { TF_HIWAT_OUT,         'o' },
 2037 
 2038         { TF_STOPPED,           'S' },
 2039         { TF_EXCLUDE,           'X' },
 2040         { TF_BYPASS,            'l' },
 2041         { TF_ZOMBIE,            'Z' },
 2042         { TF_HOOK,              's' },
 2043 
 2044         /* Keep these together -> 'bi' and 'bo'. */
 2045         { TF_BUSY,              'b' },
 2046         { TF_BUSY_IN,           'i' },
 2047         { TF_BUSY_OUT,          'o' },
 2048 
 2049         { 0,                    '\0'},
 2050 };
 2051 
 2052 #define TTY_FLAG_BITS \
 2053         "\2\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
 2054         "\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
 2055         "\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
 2056 
 2057 #define DB_PRINTSYM(name, addr) \
 2058         db_printf("%s  " #name ": ", sep); \
 2059         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
 2060         db_printf("\n");
 2061 
 2062 static void
 2063 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
 2064 {
 2065         db_printf("%sdevsw: ", sep);
 2066         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
 2067         db_printf(" (%p)\n", tsw);
 2068         DB_PRINTSYM(open, tsw->tsw_open);
 2069         DB_PRINTSYM(close, tsw->tsw_close);
 2070         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
 2071         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
 2072         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
 2073         DB_PRINTSYM(param, tsw->tsw_param);
 2074         DB_PRINTSYM(modem, tsw->tsw_modem);
 2075         DB_PRINTSYM(mmap, tsw->tsw_mmap);
 2076         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
 2077         DB_PRINTSYM(free, tsw->tsw_free);
 2078 }
 2079 static void
 2080 _db_show_hooks(const char *sep, const struct ttyhook *th)
 2081 {
 2082         db_printf("%shook: ", sep);
 2083         db_printsym((db_addr_t)th, DB_STGY_ANY);
 2084         db_printf(" (%p)\n", th);
 2085         if (th == NULL)
 2086                 return;
 2087         DB_PRINTSYM(rint, th->th_rint);
 2088         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
 2089         DB_PRINTSYM(rint_done, th->th_rint_done);
 2090         DB_PRINTSYM(rint_poll, th->th_rint_poll);
 2091         DB_PRINTSYM(getc_inject, th->th_getc_inject);
 2092         DB_PRINTSYM(getc_capture, th->th_getc_capture);
 2093         DB_PRINTSYM(getc_poll, th->th_getc_poll);
 2094         DB_PRINTSYM(close, th->th_close);
 2095 }
 2096 
 2097 static void
 2098 _db_show_termios(const char *name, const struct termios *t)
 2099 {
 2100 
 2101         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
 2102             "lflag 0x%x ispeed %u ospeed %u\n", name,
 2103             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
 2104             t->c_ispeed, t->c_ospeed);
 2105 }
 2106 
 2107 /* DDB command to show TTY statistics. */
 2108 DB_SHOW_COMMAND(tty, db_show_tty)
 2109 {
 2110         struct tty *tp;
 2111 
 2112         if (!have_addr) {
 2113                 db_printf("usage: show tty <addr>\n");
 2114                 return;
 2115         }
 2116         tp = (struct tty *)addr;
 2117 
 2118         db_printf("0x%p: %s\n", tp, tty_devname(tp));
 2119         db_printf("\tmtx: %p\n", tp->t_mtx);
 2120         db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
 2121         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
 2122 
 2123         /* Buffering mechanisms. */
 2124         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
 2125             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
 2126             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
 2127             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
 2128         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
 2129             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
 2130             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
 2131         db_printf("\tinlow: %zu\n", tp->t_inlow);
 2132         db_printf("\toutlow: %zu\n", tp->t_outlow);
 2133         _db_show_termios("\ttermios", &tp->t_termios);
 2134         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
 2135             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
 2136             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
 2137         db_printf("\tcolumn: %u\n", tp->t_column);
 2138         db_printf("\twritepos: %u\n", tp->t_writepos);
 2139         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
 2140 
 2141         /* Init/lock-state devices. */
 2142         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
 2143         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
 2144         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
 2145         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
 2146 
 2147         /* Hooks */
 2148         _db_show_devsw("\t", tp->t_devsw);
 2149         _db_show_hooks("\t", tp->t_hook);
 2150 
 2151         /* Process info. */
 2152         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
 2153             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
 2154             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
 2155         db_printf("\tsession: %p", tp->t_session);
 2156         if (tp->t_session != NULL)
 2157             db_printf(" count %u leader %p tty %p sid %d login %s",
 2158                 tp->t_session->s_count, tp->t_session->s_leader,
 2159                 tp->t_session->s_ttyp, tp->t_session->s_sid,
 2160                 tp->t_session->s_login);
 2161         db_printf("\n");
 2162         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
 2163         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
 2164         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
 2165         db_printf("\tdev: %p\n", tp->t_dev);
 2166 }
 2167 
 2168 /* DDB command to list TTYs. */
 2169 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
 2170 {
 2171         struct tty *tp;
 2172         size_t isiz, osiz;
 2173         int i, j;
 2174 
 2175         /* Make the output look like `pstat -t'. */
 2176         db_printf("PTR        ");
 2177 #if defined(__LP64__)
 2178         db_printf("        ");
 2179 #endif
 2180         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
 2181             "COL  SESS  PGID STATE\n");
 2182 
 2183         TAILQ_FOREACH(tp, &tty_list, t_list) {
 2184                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
 2185                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
 2186 
 2187                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
 2188                     tp,
 2189                     tty_devname(tp),
 2190                     isiz,
 2191                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
 2192                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
 2193                     isiz - tp->t_inlow,
 2194                     osiz,
 2195                     tp->t_outq.to_end - tp->t_outq.to_begin,
 2196                     osiz - tp->t_outlow,
 2197                     MIN(tp->t_column, 99999),
 2198                     tp->t_session ? tp->t_session->s_sid : 0,
 2199                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
 2200 
 2201                 /* Flag bits. */
 2202                 for (i = j = 0; ttystates[i].flag; i++)
 2203                         if (tp->t_flags & ttystates[i].flag) {
 2204                                 db_printf("%c", ttystates[i].val);
 2205                                 j++;
 2206                         }
 2207                 if (j == 0)
 2208                         db_printf("-");
 2209                 db_printf("\n");
 2210         }
 2211 }
 2212 #endif /* DDB */
Cache object: 3219b2322fcf7217b8668b5bf8d17498
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FreeBSD/Linux Kernel Cross Reference sys/kern/tty.c

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