sys/kern/tty.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed under sponsorship from Snow
   8  * B.V., the Netherlands.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_capsicum.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/capsicum.h>
  39 #include <sys/conf.h>
  40 #include <sys/cons.h>
  41 #include <sys/fcntl.h>
  42 #include <sys/file.h>
  43 #include <sys/filedesc.h>
  44 #include <sys/filio.h>
  45 #ifdef COMPAT_43TTY
  46 #include <sys/ioctl_compat.h>
  47 #endif /* COMPAT_43TTY */
  48 #include <sys/kernel.h>
  49 #include <sys/limits.h>
  50 #include <sys/malloc.h>
  51 #include <sys/mount.h>
  52 #include <sys/poll.h>
  53 #include <sys/priv.h>
  54 #include <sys/proc.h>
  55 #include <sys/serial.h>
  56 #include <sys/signal.h>
  57 #include <sys/stat.h>
  58 #include <sys/sx.h>
  59 #include <sys/sysctl.h>
  60 #include <sys/systm.h>
  61 #include <sys/tty.h>
  62 #include <sys/ttycom.h>
  63 #define TTYDEFCHARS
  64 #include <sys/ttydefaults.h>
  65 #undef TTYDEFCHARS
  66 #include <sys/ucred.h>
  67 #include <sys/vnode.h>
  68
  69 #include <machine/stdarg.h>
  70
  71 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
  72
  73 static void tty_rel_free(struct tty *tp);
  74
  75 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
  76 static struct sx tty_list_sx;
  77 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
  78 static unsigned int tty_list_count = 0;
  79
  80 /* Character device of /dev/console. */
  81 static struct cdev      *dev_console;
  82 static const char       *dev_console_filename;
  83
  84 /*
  85  * Flags that are supported and stored by this implementation.
  86  */
  87 #define TTYSUP_IFLAG    (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
  88                         INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
  89 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
  90 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
  91                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
  92                         FLUSHO|NOKERNINFO|NOFLSH)
  93 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
  94                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
  95                         CDSR_OFLOW|CCAR_OFLOW)
  96
  97 #define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
  98
  99 static int  tty_drainwait = 5 * 60;
 100 SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
 101     &tty_drainwait, 0, "Default output drain timeout in seconds");
 102
 103 /*
 104  * Set TTY buffer sizes.
 105  */
 106
 107 #define TTYBUF_MAX      65536
 108
 109 /*
 110  * Allocate buffer space if necessary, and set low watermarks, based on speed.
 111  * Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
 112  * lock during memory allocation.  They will return ENXIO if the tty disappears
 113  * while unlocked.
 114  */
 115 static int
 116 tty_watermarks(struct tty *tp)
 117 {
 118         size_t bs = 0;
 119         int error;
 120
 121         /* Provide an input buffer for 2 seconds of data. */
 122         if (tp->t_termios.c_cflag & CREAD)
 123                 bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
 124         error = ttyinq_setsize(&tp->t_inq, tp, bs);
 125         if (error != 0)
 126                 return (error);
 127
 128         /* Set low watermark at 10% (when 90% is available). */
 129         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
 130
 131         /* Provide an output buffer for 2 seconds of data. */
 132         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
 133         error = ttyoutq_setsize(&tp->t_outq, tp, bs);
 134         if (error != 0)
 135                 return (error);
 136
 137         /* Set low watermark at 10% (when 90% is available). */
 138         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
 139
 140         return (0);
 141 }
 142
 143 static int
 144 tty_drain(struct tty *tp, int leaving)
 145 {
 146         sbintime_t timeout_at;
 147         size_t bytes;
 148         int error;
 149
 150         if (ttyhook_hashook(tp, getc_inject))
 151                 /* buffer is inaccessible */
 152                 return (0);
 153
 154         /*
 155          * For close(), use the recent historic timeout of "1 second without
 156          * making progress".  For tcdrain(), use t_drainwait as the timeout,
 157          * with zero meaning "no timeout" which gives POSIX behavior.
 158          */
 159         if (leaving)
 160                 timeout_at = getsbinuptime() + SBT_1S;
 161         else if (tp->t_drainwait != 0)
 162                 timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
 163         else
 164                 timeout_at = 0;
 165
 166         /*
 167          * Poll the output buffer and the hardware for completion, at 10 Hz.
 168          * Polling is required for devices which are not able to signal an
 169          * interrupt when the transmitter becomes idle (most USB serial devs).
 170          * The unusual structure of this loop ensures we check for busy one more
 171          * time after tty_timedwait() returns EWOULDBLOCK, so that success has
 172          * higher priority than timeout if the IO completed in the last 100mS.
 173          */
 174         error = 0;
 175         bytes = ttyoutq_bytesused(&tp->t_outq);
 176         for (;;) {
 177                 if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
 178                         return (0);
 179                 if (error != 0)
 180                         return (error);
 181                 ttydevsw_outwakeup(tp);
 182                 error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
 183                 if (error != 0 && error != EWOULDBLOCK)
 184                         return (error);
 185                 else if (timeout_at == 0 || getsbinuptime() < timeout_at)
 186                         error = 0;
 187                 else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
 188                         /* In close, making progress, grant an extra second. */
 189                         error = 0;
 190                         timeout_at += SBT_1S;
 191                         bytes = ttyoutq_bytesused(&tp->t_outq);
 192                 }
 193         }
 194 }
 195
 196 /*
 197  * Though ttydev_enter() and ttydev_leave() seem to be related, they
 198  * don't have to be used together. ttydev_enter() is used by the cdev
 199  * operations to prevent an actual operation from being processed when
 200  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
 201  * and ttydev_close() to determine whether per-TTY data should be
 202  * deallocated.
 203  */
 204
 205 static __inline int
 206 ttydev_enter(struct tty *tp)
 207 {
 208
 209         tty_lock(tp);
 210
 211         if (tty_gone(tp) || !tty_opened(tp)) {
 212                 /* Device is already gone. */
 213                 tty_unlock(tp);
 214                 return (ENXIO);
 215         }
 216
 217         return (0);
 218 }
 219
 220 static void
 221 ttydev_leave(struct tty *tp)
 222 {
 223
 224         tty_lock_assert(tp, MA_OWNED);
 225
 226         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
 227                 /* Device is still opened somewhere. */
 228                 tty_unlock(tp);
 229                 return;
 230         }
 231
 232         tp->t_flags |= TF_OPENCLOSE;
 233
 234         /* Stop asynchronous I/O. */
 235         funsetown(&tp->t_sigio);
 236
 237         /* Remove console TTY. */
 238         if (constty == tp)
 239                 constty_clear();
 240
 241         /* Drain any output. */
 242         if (!tty_gone(tp))
 243                 tty_drain(tp, 1);
 244
 245         ttydisc_close(tp);
 246
 247         /* Free i/o queues now since they might be large. */
 248         ttyinq_free(&tp->t_inq);
 249         tp->t_inlow = 0;
 250         ttyoutq_free(&tp->t_outq);
 251         tp->t_outlow = 0;
 252
 253         knlist_clear(&tp->t_inpoll.si_note, 1);
 254         knlist_clear(&tp->t_outpoll.si_note, 1);
 255
 256         if (!tty_gone(tp))
 257                 ttydevsw_close(tp);
 258
 259         tp->t_flags &= ~TF_OPENCLOSE;
 260         cv_broadcast(&tp->t_dcdwait);
 261         tty_rel_free(tp);
 262 }
 263
 264 /*
 265  * Operations that are exposed through the character device in /dev.
 266  */
 267 static int
 268 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
 269     struct thread *td)
 270 {
 271         struct tty *tp;
 272         int error;
 273
 274         tp = dev->si_drv1;
 275         error = 0;
 276         tty_lock(tp);
 277         if (tty_gone(tp)) {
 278                 /* Device is already gone. */
 279                 tty_unlock(tp);
 280                 return (ENXIO);
 281         }
 282
 283         /*
 284          * Block when other processes are currently opening or closing
 285          * the TTY.
 286          */
 287         while (tp->t_flags & TF_OPENCLOSE) {
 288                 error = tty_wait(tp, &tp->t_dcdwait);
 289                 if (error != 0) {
 290                         tty_unlock(tp);
 291                         return (error);
 292                 }
 293         }
 294         tp->t_flags |= TF_OPENCLOSE;
 295
 296         /*
 297          * Make sure the "tty" and "cua" device cannot be opened at the
 298          * same time.  The console is a "tty" device.
 299          */
 300         if (TTY_CALLOUT(tp, dev)) {
 301                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
 302                         error = EBUSY;
 303                         goto done;
 304                 }
 305         } else {
 306                 if (tp->t_flags & TF_OPENED_OUT) {
 307                         error = EBUSY;
 308                         goto done;
 309                 }
 310         }
 311
 312         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
 313                 error = EBUSY;
 314                 goto done;
 315         }
 316
 317         if (!tty_opened(tp)) {
 318                 /* Set proper termios flags. */
 319                 if (TTY_CALLOUT(tp, dev))
 320                         tp->t_termios = tp->t_termios_init_out;
 321                 else
 322                         tp->t_termios = tp->t_termios_init_in;
 323                 ttydevsw_param(tp, &tp->t_termios);
 324                 /* Prevent modem control on callout devices and /dev/console. */
 325                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
 326                         tp->t_termios.c_cflag |= CLOCAL;
 327
 328                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
 329
 330                 error = ttydevsw_open(tp);
 331                 if (error != 0)
 332                         goto done;
 333
 334                 ttydisc_open(tp);
 335                 error = tty_watermarks(tp);
 336                 if (error != 0)
 337                         goto done;
 338         }
 339
 340         /* Wait for Carrier Detect. */
 341         if ((oflags & O_NONBLOCK) == 0 &&
 342             (tp->t_termios.c_cflag & CLOCAL) == 0) {
 343                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
 344                         error = tty_wait(tp, &tp->t_dcdwait);
 345                         if (error != 0)
 346                                 goto done;
 347                 }
 348         }
 349
 350         if (dev == dev_console)
 351                 tp->t_flags |= TF_OPENED_CONS;
 352         else if (TTY_CALLOUT(tp, dev))
 353                 tp->t_flags |= TF_OPENED_OUT;
 354         else
 355                 tp->t_flags |= TF_OPENED_IN;
 356         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 357             (tp->t_flags & TF_OPENED_OUT) == 0);
 358
 359 done:   tp->t_flags &= ~TF_OPENCLOSE;
 360         cv_broadcast(&tp->t_dcdwait);
 361         ttydev_leave(tp);
 362
 363         return (error);
 364 }
 365
 366 static int
 367 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
 368     struct thread *td __unused)
 369 {
 370         struct tty *tp = dev->si_drv1;
 371
 372         tty_lock(tp);
 373
 374         /*
 375          * Don't actually close the device if it is being used as the
 376          * console.
 377          */
 378         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 379             (tp->t_flags & TF_OPENED_OUT) == 0);
 380         if (dev == dev_console)
 381                 tp->t_flags &= ~TF_OPENED_CONS;
 382         else
 383                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
 384
 385         if (tp->t_flags & TF_OPENED) {
 386                 tty_unlock(tp);
 387                 return (0);
 388         }
 389
 390         /* If revoking, flush output now to avoid draining it later. */
 391         if (fflag & FREVOKE)
 392                 tty_flush(tp, FWRITE);
 393
 394         tp->t_flags &= ~TF_EXCLUDE;
 395
 396         /* Properly wake up threads that are stuck - revoke(). */
 397         tp->t_revokecnt++;
 398         tty_wakeup(tp, FREAD|FWRITE);
 399         cv_broadcast(&tp->t_bgwait);
 400         cv_broadcast(&tp->t_dcdwait);
 401
 402         ttydev_leave(tp);
 403
 404         return (0);
 405 }
 406
 407 static __inline int
 408 tty_is_ctty(struct tty *tp, struct proc *p)
 409 {
 410
 411         tty_lock_assert(tp, MA_OWNED);
 412
 413         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
 414 }
 415
 416 int
 417 tty_wait_background(struct tty *tp, struct thread *td, int sig)
 418 {
 419         struct proc *p = td->td_proc;
 420         struct pgrp *pg;
 421         ksiginfo_t ksi;
 422         int error;
 423
 424         MPASS(sig == SIGTTIN || sig == SIGTTOU);
 425         tty_lock_assert(tp, MA_OWNED);
 426
 427         for (;;) {
 428                 PROC_LOCK(p);
 429                 /*
 430                  * The process should only sleep, when:
 431                  * - This terminal is the controlling terminal
 432                  * - Its process group is not the foreground process
 433                  *   group
 434                  * - The parent process isn't waiting for the child to
 435                  *   exit
 436                  * - the signal to send to the process isn't masked
 437                  */
 438                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
 439                         /* Allow the action to happen. */
 440                         PROC_UNLOCK(p);
 441                         return (0);
 442                 }
 443
 444                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
 445                     SIGISMEMBER(td->td_sigmask, sig)) {
 446                         /* Only allow them in write()/ioctl(). */
 447                         PROC_UNLOCK(p);
 448                         return (sig == SIGTTOU ? 0 : EIO);
 449                 }
 450
 451                 pg = p->p_pgrp;
 452                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
 453                         /* Don't allow the action to happen. */
 454                         PROC_UNLOCK(p);
 455                         return (EIO);
 456                 }
 457                 PROC_UNLOCK(p);
 458
 459                 /*
 460                  * Send the signal and sleep until we're the new
 461                  * foreground process group.
 462                  */
 463                 if (sig != 0) {
 464                         ksiginfo_init(&ksi);
 465                         ksi.ksi_code = SI_KERNEL;
 466                         ksi.ksi_signo = sig;
 467                         sig = 0;
 468                 }
 469                 PGRP_LOCK(pg);
 470                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
 471                 PGRP_UNLOCK(pg);
 472
 473                 error = tty_wait(tp, &tp->t_bgwait);
 474                 if (error)
 475                         return (error);
 476         }
 477 }
 478
 479 static int
 480 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
 481 {
 482         struct tty *tp = dev->si_drv1;
 483         int error;
 484
 485         error = ttydev_enter(tp);
 486         if (error)
 487                 goto done;
 488         error = ttydisc_read(tp, uio, ioflag);
 489         tty_unlock(tp);
 490
 491         /*
 492          * The read() call should not throw an error when the device is
 493          * being destroyed. Silently convert it to an EOF.
 494          */
 495 done:   if (error == ENXIO)
 496                 error = 0;
 497         return (error);
 498 }
 499
 500 static int
 501 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
 502 {
 503         struct tty *tp = dev->si_drv1;
 504         int error;
 505
 506         error = ttydev_enter(tp);
 507         if (error)
 508                 return (error);
 509
 510         if (tp->t_termios.c_lflag & TOSTOP) {
 511                 error = tty_wait_background(tp, curthread, SIGTTOU);
 512                 if (error)
 513                         goto done;
 514         }
 515
 516         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
 517                 /* Allow non-blocking writes to bypass serialization. */
 518                 error = ttydisc_write(tp, uio, ioflag);
 519         } else {
 520                 /* Serialize write() calls. */
 521                 while (tp->t_flags & TF_BUSY_OUT) {
 522                         error = tty_wait(tp, &tp->t_outserwait);
 523                         if (error)
 524                                 goto done;
 525                 }
 526
 527                 tp->t_flags |= TF_BUSY_OUT;
 528                 error = ttydisc_write(tp, uio, ioflag);
 529                 tp->t_flags &= ~TF_BUSY_OUT;
 530                 cv_signal(&tp->t_outserwait);
 531         }
 532
 533 done:   tty_unlock(tp);
 534         return (error);
 535 }
 536
 537 static int
 538 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 539     struct thread *td)
 540 {
 541         struct tty *tp = dev->si_drv1;
 542         int error;
 543
 544         error = ttydev_enter(tp);
 545         if (error)
 546                 return (error);
 547
 548         switch (cmd) {
 549         case TIOCCBRK:
 550         case TIOCCONS:
 551         case TIOCDRAIN:
 552         case TIOCEXCL:
 553         case TIOCFLUSH:
 554         case TIOCNXCL:
 555         case TIOCSBRK:
 556         case TIOCSCTTY:
 557         case TIOCSETA:
 558         case TIOCSETAF:
 559         case TIOCSETAW:
 560         case TIOCSPGRP:
 561         case TIOCSTART:
 562         case TIOCSTAT:
 563         case TIOCSTI:
 564         case TIOCSTOP:
 565         case TIOCSWINSZ:
 566 #if 0
 567         case TIOCSDRAINWAIT:
 568         case TIOCSETD:
 569 #endif
 570 #ifdef COMPAT_43TTY
 571         case  TIOCLBIC:
 572         case  TIOCLBIS:
 573         case  TIOCLSET:
 574         case  TIOCSETC:
 575         case OTIOCSETD:
 576         case  TIOCSETN:
 577         case  TIOCSETP:
 578         case  TIOCSLTC:
 579 #endif /* COMPAT_43TTY */
 580                 /*
 581                  * If the ioctl() causes the TTY to be modified, let it
 582                  * wait in the background.
 583                  */
 584                 error = tty_wait_background(tp, curthread, SIGTTOU);
 585                 if (error)
 586                         goto done;
 587         }
 588
 589         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 590                 struct termios *old = &tp->t_termios;
 591                 struct termios *new = (struct termios *)data;
 592                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
 593                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
 594                 int cc;
 595
 596                 /*
 597                  * Lock state devices.  Just overwrite the values of the
 598                  * commands that are currently in use.
 599                  */
 600                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
 601                     (new->c_iflag & ~lock->c_iflag);
 602                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
 603                     (new->c_oflag & ~lock->c_oflag);
 604                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
 605                     (new->c_cflag & ~lock->c_cflag);
 606                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
 607                     (new->c_lflag & ~lock->c_lflag);
 608                 for (cc = 0; cc < NCCS; ++cc)
 609                         if (lock->c_cc[cc])
 610                                 new->c_cc[cc] = old->c_cc[cc];
 611                 if (lock->c_ispeed)
 612                         new->c_ispeed = old->c_ispeed;
 613                 if (lock->c_ospeed)
 614                         new->c_ospeed = old->c_ospeed;
 615         }
 616
 617         error = tty_ioctl(tp, cmd, data, fflag, td);
 618 done:   tty_unlock(tp);
 619
 620         return (error);
 621 }
 622
 623 static int
 624 ttydev_poll(struct cdev *dev, int events, struct thread *td)
 625 {
 626         struct tty *tp = dev->si_drv1;
 627         int error, revents = 0;
 628
 629         error = ttydev_enter(tp);
 630         if (error)
 631                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
 632
 633         if (events & (POLLIN|POLLRDNORM)) {
 634                 /* See if we can read something. */
 635                 if (ttydisc_read_poll(tp) > 0)
 636                         revents |= events & (POLLIN|POLLRDNORM);
 637         }
 638
 639         if (tp->t_flags & TF_ZOMBIE) {
 640                 /* Hangup flag on zombie state. */
 641                 revents |= POLLHUP;
 642         } else if (events & (POLLOUT|POLLWRNORM)) {
 643                 /* See if we can write something. */
 644                 if (ttydisc_write_poll(tp) > 0)
 645                         revents |= events & (POLLOUT|POLLWRNORM);
 646         }
 647
 648         if (revents == 0) {
 649                 if (events & (POLLIN|POLLRDNORM))
 650                         selrecord(td, &tp->t_inpoll);
 651                 if (events & (POLLOUT|POLLWRNORM))
 652                         selrecord(td, &tp->t_outpoll);
 653         }
 654
 655         tty_unlock(tp);
 656
 657         return (revents);
 658 }
 659
 660 static int
 661 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
 662     int nprot, vm_memattr_t *memattr)
 663 {
 664         struct tty *tp = dev->si_drv1;
 665         int error;
 666
 667         /* Handle mmap() through the driver. */
 668
 669         error = ttydev_enter(tp);
 670         if (error)
 671                 return (-1);
 672         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
 673         tty_unlock(tp);
 674
 675         return (error);
 676 }
 677
 678 /*
 679  * kqueue support.
 680  */
 681
 682 static void
 683 tty_kqops_read_detach(struct knote *kn)
 684 {
 685         struct tty *tp = kn->kn_hook;
 686
 687         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
 688 }
 689
 690 static int
 691 tty_kqops_read_event(struct knote *kn, long hint __unused)
 692 {
 693         struct tty *tp = kn->kn_hook;
 694
 695         tty_lock_assert(tp, MA_OWNED);
 696
 697         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
 698                 kn->kn_flags |= EV_EOF;
 699                 return (1);
 700         } else {
 701                 kn->kn_data = ttydisc_read_poll(tp);
 702                 return (kn->kn_data > 0);
 703         }
 704 }
 705
 706 static void
 707 tty_kqops_write_detach(struct knote *kn)
 708 {
 709         struct tty *tp = kn->kn_hook;
 710
 711         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
 712 }
 713
 714 static int
 715 tty_kqops_write_event(struct knote *kn, long hint __unused)
 716 {
 717         struct tty *tp = kn->kn_hook;
 718
 719         tty_lock_assert(tp, MA_OWNED);
 720
 721         if (tty_gone(tp)) {
 722                 kn->kn_flags |= EV_EOF;
 723                 return (1);
 724         } else {
 725                 kn->kn_data = ttydisc_write_poll(tp);
 726                 return (kn->kn_data > 0);
 727         }
 728 }
 729
 730 static struct filterops tty_kqops_read = {
 731         .f_isfd = 1,
 732         .f_detach = tty_kqops_read_detach,
 733         .f_event = tty_kqops_read_event,
 734 };
 735
 736 static struct filterops tty_kqops_write = {
 737         .f_isfd = 1,
 738         .f_detach = tty_kqops_write_detach,
 739         .f_event = tty_kqops_write_event,
 740 };
 741
 742 static int
 743 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
 744 {
 745         struct tty *tp = dev->si_drv1;
 746         int error;
 747
 748         error = ttydev_enter(tp);
 749         if (error)
 750                 return (error);
 751
 752         switch (kn->kn_filter) {
 753         case EVFILT_READ:
 754                 kn->kn_hook = tp;
 755                 kn->kn_fop = &tty_kqops_read;
 756                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
 757                 break;
 758         case EVFILT_WRITE:
 759                 kn->kn_hook = tp;
 760                 kn->kn_fop = &tty_kqops_write;
 761                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
 762                 break;
 763         default:
 764                 error = EINVAL;
 765                 break;
 766         }
 767
 768         tty_unlock(tp);
 769         return (error);
 770 }
 771
 772 static struct cdevsw ttydev_cdevsw = {
 773         .d_version      = D_VERSION,
 774         .d_open         = ttydev_open,
 775         .d_close        = ttydev_close,
 776         .d_read         = ttydev_read,
 777         .d_write        = ttydev_write,
 778         .d_ioctl        = ttydev_ioctl,
 779         .d_kqfilter     = ttydev_kqfilter,
 780         .d_poll         = ttydev_poll,
 781         .d_mmap         = ttydev_mmap,
 782         .d_name         = "ttydev",
 783         .d_flags        = D_TTY,
 784 };
 785
 786 /*
 787  * Init/lock-state devices
 788  */
 789
 790 static int
 791 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
 792     struct thread *td)
 793 {
 794         struct tty *tp;
 795         int error;
 796
 797         tp = dev->si_drv1;
 798         error = 0;
 799         tty_lock(tp);
 800         if (tty_gone(tp))
 801                 error = ENODEV;
 802         tty_unlock(tp);
 803
 804         return (error);
 805 }
 806
 807 static int
 808 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
 809     struct thread *td __unused)
 810 {
 811
 812         return (0);
 813 }
 814
 815 static int
 816 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
 817     int ioflag __unused)
 818 {
 819
 820         return (ENODEV);
 821 }
 822
 823 static int
 824 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 825     struct thread *td)
 826 {
 827         struct tty *tp = dev->si_drv1;
 828         int error;
 829
 830         tty_lock(tp);
 831         if (tty_gone(tp)) {
 832                 error = ENODEV;
 833                 goto done;
 834         }
 835
 836         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
 837         if (error != ENOIOCTL)
 838                 goto done;
 839         error = 0;
 840
 841         switch (cmd) {
 842         case TIOCGETA:
 843                 /* Obtain terminal flags through tcgetattr(). */
 844                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
 845                 break;
 846         case TIOCSETA:
 847                 /* Set terminal flags through tcsetattr(). */
 848                 error = priv_check(td, PRIV_TTY_SETA);
 849                 if (error)
 850                         break;
 851                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
 852                 break;
 853         case TIOCGETD:
 854                 *(int *)data = TTYDISC;
 855                 break;
 856         case TIOCGWINSZ:
 857                 bzero(data, sizeof(struct winsize));
 858                 break;
 859         default:
 860                 error = ENOTTY;
 861         }
 862
 863 done:   tty_unlock(tp);
 864         return (error);
 865 }
 866
 867 static struct cdevsw ttyil_cdevsw = {
 868         .d_version      = D_VERSION,
 869         .d_open         = ttyil_open,
 870         .d_close        = ttyil_close,
 871         .d_read         = ttyil_rdwr,
 872         .d_write        = ttyil_rdwr,
 873         .d_ioctl        = ttyil_ioctl,
 874         .d_name         = "ttyil",
 875         .d_flags        = D_TTY,
 876 };
 877
 878 static void
 879 tty_init_termios(struct tty *tp)
 880 {
 881         struct termios *t = &tp->t_termios_init_in;
 882
 883         t->c_cflag = TTYDEF_CFLAG;
 884         t->c_iflag = TTYDEF_IFLAG;
 885         t->c_lflag = TTYDEF_LFLAG;
 886         t->c_oflag = TTYDEF_OFLAG;
 887         t->c_ispeed = TTYDEF_SPEED;
 888         t->c_ospeed = TTYDEF_SPEED;
 889         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
 890
 891         tp->t_termios_init_out = *t;
 892 }
 893
 894 void
 895 tty_init_console(struct tty *tp, speed_t s)
 896 {
 897         struct termios *ti = &tp->t_termios_init_in;
 898         struct termios *to = &tp->t_termios_init_out;
 899
 900         if (s != 0) {
 901                 ti->c_ispeed = ti->c_ospeed = s;
 902                 to->c_ispeed = to->c_ospeed = s;
 903         }
 904
 905         ti->c_cflag |= CLOCAL;
 906         to->c_cflag |= CLOCAL;
 907 }
 908
 909 /*
 910  * Standard device routine implementations, mostly meant for
 911  * pseudo-terminal device drivers. When a driver creates a new terminal
 912  * device class, missing routines are patched.
 913  */
 914
 915 static int
 916 ttydevsw_defopen(struct tty *tp __unused)
 917 {
 918
 919         return (0);
 920 }
 921
 922 static void
 923 ttydevsw_defclose(struct tty *tp __unused)
 924 {
 925
 926 }
 927
 928 static void
 929 ttydevsw_defoutwakeup(struct tty *tp __unused)
 930 {
 931
 932         panic("Terminal device has output, while not implemented");
 933 }
 934
 935 static void
 936 ttydevsw_definwakeup(struct tty *tp __unused)
 937 {
 938
 939 }
 940
 941 static int
 942 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
 943     caddr_t data __unused, struct thread *td __unused)
 944 {
 945
 946         return (ENOIOCTL);
 947 }
 948
 949 static int
 950 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
 951     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
 952 {
 953
 954         return (ENOIOCTL);
 955 }
 956
 957 static int
 958 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
 959 {
 960
 961         /*
 962          * Allow the baud rate to be adjusted for pseudo-devices, but at
 963          * least restrict it to 115200 to prevent excessive buffer
 964          * usage.  Also disallow 0, to prevent foot shooting.
 965          */
 966         if (t->c_ispeed < B50)
 967                 t->c_ispeed = B50;
 968         else if (t->c_ispeed > B115200)
 969                 t->c_ispeed = B115200;
 970         if (t->c_ospeed < B50)
 971                 t->c_ospeed = B50;
 972         else if (t->c_ospeed > B115200)
 973                 t->c_ospeed = B115200;
 974         t->c_cflag |= CREAD;
 975
 976         return (0);
 977 }
 978
 979 static int
 980 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
 981     int sigoff __unused)
 982 {
 983
 984         /* Simulate a carrier to make the TTY layer happy. */
 985         return (SER_DCD);
 986 }
 987
 988 static int
 989 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
 990     vm_paddr_t *paddr __unused, int nprot __unused,
 991     vm_memattr_t *memattr __unused)
 992 {
 993
 994         return (-1);
 995 }
 996
 997 static void
 998 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
 999 {
1000
1001 }
1002
1003 static void
1004 ttydevsw_deffree(void *softc __unused)
1005 {
1006
1007         panic("Terminal device freed without a free-handler");
1008 }
1009
1010 static bool
1011 ttydevsw_defbusy(struct tty *tp __unused)
1012 {
1013
1014         return (FALSE);
1015 }
1016
1017 /*
1018  * TTY allocation and deallocation. TTY devices can be deallocated when
1019  * the driver doesn't use it anymore, when the TTY isn't a session's
1020  * controlling TTY and when the device node isn't opened through devfs.
1021  */
1022
1023 struct tty *
1024 tty_alloc(struct ttydevsw *tsw, void *sc)
1025 {
1026
1027         return (tty_alloc_mutex(tsw, sc, NULL));
1028 }
1029
1030 struct tty *
1031 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
1032 {
1033         struct tty *tp;
1034
1035         /* Make sure the driver defines all routines. */
1036 #define PATCH_FUNC(x) do {                              \
1037         if (tsw->tsw_ ## x == NULL)                     \
1038                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
1039 } while (0)
1040         PATCH_FUNC(open);
1041         PATCH_FUNC(close);
1042         PATCH_FUNC(outwakeup);
1043         PATCH_FUNC(inwakeup);
1044         PATCH_FUNC(ioctl);
1045         PATCH_FUNC(cioctl);
1046         PATCH_FUNC(param);
1047         PATCH_FUNC(modem);
1048         PATCH_FUNC(mmap);
1049         PATCH_FUNC(pktnotify);
1050         PATCH_FUNC(free);
1051         PATCH_FUNC(busy);
1052 #undef PATCH_FUNC
1053
1054         tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
1055         tp->t_devsw = tsw;
1056         tp->t_devswsoftc = sc;
1057         tp->t_flags = tsw->tsw_flags;
1058         tp->t_drainwait = tty_drainwait;
1059
1060         tty_init_termios(tp);
1061
1062         cv_init(&tp->t_inwait, "ttyin");
1063         cv_init(&tp->t_outwait, "ttyout");
1064         cv_init(&tp->t_outserwait, "ttyosr");
1065         cv_init(&tp->t_bgwait, "ttybg");
1066         cv_init(&tp->t_dcdwait, "ttydcd");
1067
1068         /* Allow drivers to use a custom mutex to lock the TTY. */
1069         if (mutex != NULL) {
1070                 tp->t_mtx = mutex;
1071         } else {
1072                 tp->t_mtx = &tp->t_mtxobj;
1073                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1074         }
1075
1076         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1077         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1078
1079         return (tp);
1080 }
1081
1082 static void
1083 tty_dealloc(void *arg)
1084 {
1085         struct tty *tp = arg;
1086
1087         /*
1088          * ttyydev_leave() usually frees the i/o queues earlier, but it is
1089          * not always called between queue allocation and here.  The queues
1090          * may be allocated by ioctls on a pty control device without the
1091          * corresponding pty slave device ever being open, or after it is
1092          * closed.
1093          */
1094         ttyinq_free(&tp->t_inq);
1095         ttyoutq_free(&tp->t_outq);
1096         seldrain(&tp->t_inpoll);
1097         seldrain(&tp->t_outpoll);
1098         knlist_destroy(&tp->t_inpoll.si_note);
1099         knlist_destroy(&tp->t_outpoll.si_note);
1100
1101         cv_destroy(&tp->t_inwait);
1102         cv_destroy(&tp->t_outwait);
1103         cv_destroy(&tp->t_bgwait);
1104         cv_destroy(&tp->t_dcdwait);
1105         cv_destroy(&tp->t_outserwait);
1106
1107         if (tp->t_mtx == &tp->t_mtxobj)
1108                 mtx_destroy(&tp->t_mtxobj);
1109         ttydevsw_free(tp);
1110         free(tp, M_TTY);
1111 }
1112
1113 static void
1114 tty_rel_free(struct tty *tp)
1115 {
1116         struct cdev *dev;
1117
1118         tty_lock_assert(tp, MA_OWNED);
1119
1120 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1121         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1122                 /* TTY is still in use. */
1123                 tty_unlock(tp);
1124                 return;
1125         }
1126
1127         /* TTY can be deallocated. */
1128         dev = tp->t_dev;
1129         tp->t_dev = NULL;
1130         tty_unlock(tp);
1131
1132         if (dev != NULL) {
1133                 sx_xlock(&tty_list_sx);
1134                 TAILQ_REMOVE(&tty_list, tp, t_list);
1135                 tty_list_count--;
1136                 sx_xunlock(&tty_list_sx);
1137                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
1138         }
1139 }
1140
1141 void
1142 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1143 {
1144
1145         MPASS(tp->t_sessioncnt > 0);
1146         tty_lock_assert(tp, MA_OWNED);
1147
1148         if (tp->t_pgrp == pg)
1149                 tp->t_pgrp = NULL;
1150
1151         tty_unlock(tp);
1152 }
1153
1154 void
1155 tty_rel_sess(struct tty *tp, struct session *sess)
1156 {
1157
1158         MPASS(tp->t_sessioncnt > 0);
1159
1160         /* Current session has left. */
1161         if (tp->t_session == sess) {
1162                 tp->t_session = NULL;
1163                 MPASS(tp->t_pgrp == NULL);
1164         }
1165         tp->t_sessioncnt--;
1166         tty_rel_free(tp);
1167 }
1168
1169 void
1170 tty_rel_gone(struct tty *tp)
1171 {
1172
1173         MPASS(!tty_gone(tp));
1174
1175         /* Simulate carrier removal. */
1176         ttydisc_modem(tp, 0);
1177
1178         /* Wake up all blocked threads. */
1179         tty_wakeup(tp, FREAD|FWRITE);
1180         cv_broadcast(&tp->t_bgwait);
1181         cv_broadcast(&tp->t_dcdwait);
1182
1183         tp->t_flags |= TF_GONE;
1184         tty_rel_free(tp);
1185 }
1186
1187 /*
1188  * Exposing information about current TTY's through sysctl
1189  */
1190
1191 static void
1192 tty_to_xtty(struct tty *tp, struct xtty *xt)
1193 {
1194
1195         tty_lock_assert(tp, MA_OWNED);
1196
1197         xt->xt_size = sizeof(struct xtty);
1198         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1199         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1200         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1201         xt->xt_inlow = tp->t_inlow;
1202         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1203         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1204         xt->xt_outlow = tp->t_outlow;
1205         xt->xt_column = tp->t_column;
1206         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1207         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1208         xt->xt_flags = tp->t_flags;
1209         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : (uint32_t)NODEV;
1210 }
1211
1212 static int
1213 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1214 {
1215         unsigned long lsize;
1216         struct xtty *xtlist, *xt;
1217         struct tty *tp;
1218         int error;
1219
1220         sx_slock(&tty_list_sx);
1221         lsize = tty_list_count * sizeof(struct xtty);
1222         if (lsize == 0) {
1223                 sx_sunlock(&tty_list_sx);
1224                 return (0);
1225         }
1226
1227         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1228
1229         TAILQ_FOREACH(tp, &tty_list, t_list) {
1230                 tty_lock(tp);
1231                 tty_to_xtty(tp, xt);
1232                 tty_unlock(tp);
1233                 xt++;
1234         }
1235         sx_sunlock(&tty_list_sx);
1236
1237         error = SYSCTL_OUT(req, xtlist, lsize);
1238         free(xtlist, M_TTY);
1239         return (error);
1240 }
1241
1242 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1243         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1244
1245 /*
1246  * Device node creation. Device has been set up, now we can expose it to
1247  * the user.
1248  */
1249
1250 int
1251 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1252     const char *fmt, ...)
1253 {
1254         va_list ap;
1255         struct make_dev_args args;
1256         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1257         const char *prefix = "tty";
1258         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1259         uid_t uid;
1260         gid_t gid;
1261         mode_t mode;
1262         int error;
1263
1264         /* Remove "tty" prefix from devices like PTY's. */
1265         if (tp->t_flags & TF_NOPREFIX)
1266                 prefix = "";
1267
1268         va_start(ap, fmt);
1269         vsnrprintf(name, sizeof name, 32, fmt, ap);
1270         va_end(ap);
1271
1272         if (cred == NULL) {
1273                 /* System device. */
1274                 uid = UID_ROOT;
1275                 gid = GID_WHEEL;
1276                 mode = S_IRUSR|S_IWUSR;
1277         } else {
1278                 /* User device. */
1279                 uid = cred->cr_ruid;
1280                 gid = GID_TTY;
1281                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
1282         }
1283
1284         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1285         flags |= MAKEDEV_CHECKNAME;
1286
1287         /* Master call-in device. */
1288         make_dev_args_init(&args);
1289         args.mda_flags = flags;
1290         args.mda_devsw = &ttydev_cdevsw;
1291         args.mda_cr = cred;
1292         args.mda_uid = uid;
1293         args.mda_gid = gid;
1294         args.mda_mode = mode;
1295         args.mda_si_drv1 = tp;
1296         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1297         if (error != 0)
1298                 return (error);
1299         tp->t_dev = dev;
1300
1301         init = lock = cua = cinit = clock = NULL;
1302
1303         /* Slave call-in devices. */
1304         if (tp->t_flags & TF_INITLOCK) {
1305                 args.mda_devsw = &ttyil_cdevsw;
1306                 args.mda_unit = TTYUNIT_INIT;
1307                 args.mda_si_drv1 = tp;
1308                 args.mda_si_drv2 = &tp->t_termios_init_in;
1309                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1310                 if (error != 0)
1311                         goto fail;
1312                 dev_depends(dev, init);
1313
1314                 args.mda_unit = TTYUNIT_LOCK;
1315                 args.mda_si_drv2 = &tp->t_termios_lock_in;
1316                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1317                 if (error != 0)
1318                         goto fail;
1319                 dev_depends(dev, lock);
1320         }
1321
1322         /* Call-out devices. */
1323         if (tp->t_flags & TF_CALLOUT) {
1324                 make_dev_args_init(&args);
1325                 args.mda_flags = flags;
1326                 args.mda_devsw = &ttydev_cdevsw;
1327                 args.mda_cr = cred;
1328                 args.mda_uid = UID_UUCP;
1329                 args.mda_gid = GID_DIALER;
1330                 args.mda_mode = 0660;
1331                 args.mda_unit = TTYUNIT_CALLOUT;
1332                 args.mda_si_drv1 = tp;
1333                 error = make_dev_s(&args, &cua, "cua%s", name);
1334                 if (error != 0)
1335                         goto fail;
1336                 dev_depends(dev, cua);
1337
1338                 /* Slave call-out devices. */
1339                 if (tp->t_flags & TF_INITLOCK) {
1340                         args.mda_devsw = &ttyil_cdevsw;
1341                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1342                         args.mda_si_drv2 = &tp->t_termios_init_out;
1343                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
1344                         if (error != 0)
1345                                 goto fail;
1346                         dev_depends(dev, cinit);
1347
1348                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1349                         args.mda_si_drv2 = &tp->t_termios_lock_out;
1350                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
1351                         if (error != 0)
1352                                 goto fail;
1353                         dev_depends(dev, clock);
1354                 }
1355         }
1356
1357         sx_xlock(&tty_list_sx);
1358         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1359         tty_list_count++;
1360         sx_xunlock(&tty_list_sx);
1361
1362         return (0);
1363
1364 fail:
1365         destroy_dev(dev);
1366         if (init)
1367                 destroy_dev(init);
1368         if (lock)
1369                 destroy_dev(lock);
1370         if (cinit)
1371                 destroy_dev(cinit);
1372         if (clock)
1373                 destroy_dev(clock);
1374
1375         return (error);
1376 }
1377
1378 /*
1379  * Signalling processes.
1380  */
1381
1382 void
1383 tty_signal_sessleader(struct tty *tp, int sig)
1384 {
1385         struct proc *p;
1386
1387         tty_lock_assert(tp, MA_OWNED);
1388         MPASS(sig >= 1 && sig < NSIG);
1389
1390         /* Make signals start output again. */
1391         tp->t_flags &= ~TF_STOPPED;
1392
1393         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1394                 p = tp->t_session->s_leader;
1395                 PROC_LOCK(p);
1396                 kern_psignal(p, sig);
1397                 PROC_UNLOCK(p);
1398         }
1399 }
1400
1401 void
1402 tty_signal_pgrp(struct tty *tp, int sig)
1403 {
1404         ksiginfo_t ksi;
1405
1406         tty_lock_assert(tp, MA_OWNED);
1407         MPASS(sig >= 1 && sig < NSIG);
1408
1409         /* Make signals start output again. */
1410         tp->t_flags &= ~TF_STOPPED;
1411
1412         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1413                 tty_info(tp);
1414         if (tp->t_pgrp != NULL) {
1415                 ksiginfo_init(&ksi);
1416                 ksi.ksi_signo = sig;
1417                 ksi.ksi_code = SI_KERNEL;
1418                 PGRP_LOCK(tp->t_pgrp);
1419                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
1420                 PGRP_UNLOCK(tp->t_pgrp);
1421         }
1422 }
1423
1424 void
1425 tty_wakeup(struct tty *tp, int flags)
1426 {
1427
1428         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1429                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1430
1431         if (flags & FWRITE) {
1432                 cv_broadcast(&tp->t_outwait);
1433                 selwakeup(&tp->t_outpoll);
1434                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1435         }
1436         if (flags & FREAD) {
1437                 cv_broadcast(&tp->t_inwait);
1438                 selwakeup(&tp->t_inpoll);
1439                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1440         }
1441 }
1442
1443 int
1444 tty_wait(struct tty *tp, struct cv *cv)
1445 {
1446         int error;
1447         int revokecnt = tp->t_revokecnt;
1448
1449         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1450         MPASS(!tty_gone(tp));
1451
1452         error = cv_wait_sig(cv, tp->t_mtx);
1453
1454         /* Bail out when the device slipped away. */
1455         if (tty_gone(tp))
1456                 return (ENXIO);
1457
1458         /* Restart the system call when we may have been revoked. */
1459         if (tp->t_revokecnt != revokecnt)
1460                 return (ERESTART);
1461
1462         return (error);
1463 }
1464
1465 int
1466 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1467 {
1468         int error;
1469         int revokecnt = tp->t_revokecnt;
1470
1471         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1472         MPASS(!tty_gone(tp));
1473
1474         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1475
1476         /* Bail out when the device slipped away. */
1477         if (tty_gone(tp))
1478                 return (ENXIO);
1479
1480         /* Restart the system call when we may have been revoked. */
1481         if (tp->t_revokecnt != revokecnt)
1482                 return (ERESTART);
1483
1484         return (error);
1485 }
1486
1487 void
1488 tty_flush(struct tty *tp, int flags)
1489 {
1490
1491         if (flags & FWRITE) {
1492                 tp->t_flags &= ~TF_HIWAT_OUT;
1493                 ttyoutq_flush(&tp->t_outq);
1494                 tty_wakeup(tp, FWRITE);
1495                 if (!tty_gone(tp)) {
1496                         ttydevsw_outwakeup(tp);
1497                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1498                 }
1499         }
1500         if (flags & FREAD) {
1501                 tty_hiwat_in_unblock(tp);
1502                 ttyinq_flush(&tp->t_inq);
1503                 tty_wakeup(tp, FREAD);
1504                 if (!tty_gone(tp)) {
1505                         ttydevsw_inwakeup(tp);
1506                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1507                 }
1508         }
1509 }
1510
1511 void
1512 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1513 {
1514
1515         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1516                 return;
1517         tp->t_winsize = *wsz;
1518         tty_signal_pgrp(tp, SIGWINCH);
1519 }
1520
1521 static int
1522 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1523     struct thread *td)
1524 {
1525         int error;
1526
1527         switch (cmd) {
1528         /*
1529          * Modem commands.
1530          * The SER_* and TIOCM_* flags are the same, but one bit
1531          * shifted. I don't know why.
1532          */
1533         case TIOCSDTR:
1534                 ttydevsw_modem(tp, SER_DTR, 0);
1535                 return (0);
1536         case TIOCCDTR:
1537                 ttydevsw_modem(tp, 0, SER_DTR);
1538                 return (0);
1539         case TIOCMSET: {
1540                 int bits = *(int *)data;
1541                 ttydevsw_modem(tp,
1542                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1543                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1544                 return (0);
1545         }
1546         case TIOCMBIS: {
1547                 int bits = *(int *)data;
1548                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1549                 return (0);
1550         }
1551         case TIOCMBIC: {
1552                 int bits = *(int *)data;
1553                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1554                 return (0);
1555         }
1556         case TIOCMGET:
1557                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1558                 return (0);
1559
1560         case FIOASYNC:
1561                 if (*(int *)data)
1562                         tp->t_flags |= TF_ASYNC;
1563                 else
1564                         tp->t_flags &= ~TF_ASYNC;
1565                 return (0);
1566         case FIONBIO:
1567                 /* This device supports non-blocking operation. */
1568                 return (0);
1569         case FIONREAD:
1570                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1571                 return (0);
1572         case FIONWRITE:
1573         case TIOCOUTQ:
1574                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
1575                 return (0);
1576         case FIOSETOWN:
1577                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1578                         /* Not allowed to set ownership. */
1579                         return (ENOTTY);
1580
1581                 /* Temporarily unlock the TTY to set ownership. */
1582                 tty_unlock(tp);
1583                 error = fsetown(*(int *)data, &tp->t_sigio);
1584                 tty_lock(tp);
1585                 return (error);
1586         case FIOGETOWN:
1587                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1588                         /* Not allowed to set ownership. */
1589                         return (ENOTTY);
1590
1591                 /* Get ownership. */
1592                 *(int *)data = fgetown(&tp->t_sigio);
1593                 return (0);
1594         case TIOCGETA:
1595                 /* Obtain terminal flags through tcgetattr(). */
1596                 *(struct termios*)data = tp->t_termios;
1597                 return (0);
1598         case TIOCSETA:
1599         case TIOCSETAW:
1600         case TIOCSETAF: {
1601                 struct termios *t = data;
1602
1603                 /*
1604                  * Who makes up these funny rules? According to POSIX,
1605                  * input baud rate is set equal to the output baud rate
1606                  * when zero.
1607                  */
1608                 if (t->c_ispeed == 0)
1609                         t->c_ispeed = t->c_ospeed;
1610
1611                 /* Discard any unsupported bits. */
1612                 t->c_iflag &= TTYSUP_IFLAG;
1613                 t->c_oflag &= TTYSUP_OFLAG;
1614                 t->c_lflag &= TTYSUP_LFLAG;
1615                 t->c_cflag &= TTYSUP_CFLAG;
1616
1617                 /* Set terminal flags through tcsetattr(). */
1618                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1619                         error = tty_drain(tp, 0);
1620                         if (error)
1621                                 return (error);
1622                         if (cmd == TIOCSETAF)
1623                                 tty_flush(tp, FREAD);
1624                 }
1625
1626                 /*
1627                  * Only call param() when the flags really change.
1628                  */
1629                 if ((t->c_cflag & CIGNORE) == 0 &&
1630                     (tp->t_termios.c_cflag != t->c_cflag ||
1631                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
1632                     (IXON|IXOFF|IXANY)) ||
1633                     tp->t_termios.c_ispeed != t->c_ispeed ||
1634                     tp->t_termios.c_ospeed != t->c_ospeed)) {
1635                         error = ttydevsw_param(tp, t);
1636                         if (error)
1637                                 return (error);
1638
1639                         /* XXX: CLOCAL? */
1640
1641                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1642                         tp->t_termios.c_ispeed = t->c_ispeed;
1643                         tp->t_termios.c_ospeed = t->c_ospeed;
1644
1645                         /* Baud rate has changed - update watermarks. */
1646                         error = tty_watermarks(tp);
1647                         if (error)
1648                                 return (error);
1649                 }
1650
1651                 /* Copy new non-device driver parameters. */
1652                 tp->t_termios.c_iflag = t->c_iflag;
1653                 tp->t_termios.c_oflag = t->c_oflag;
1654                 tp->t_termios.c_lflag = t->c_lflag;
1655                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1656
1657                 ttydisc_optimize(tp);
1658
1659                 if ((t->c_lflag & ICANON) == 0) {
1660                         /*
1661                          * When in non-canonical mode, wake up all
1662                          * readers. Canonicalize any partial input. VMIN
1663                          * and VTIME could also be adjusted.
1664                          */
1665                         ttyinq_canonicalize(&tp->t_inq);
1666                         tty_wakeup(tp, FREAD);
1667                 }
1668
1669                 /*
1670                  * For packet mode: notify the PTY consumer that VSTOP
1671                  * and VSTART may have been changed.
1672                  */
1673                 if (tp->t_termios.c_iflag & IXON &&
1674                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1675                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1676                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1677                 else
1678                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1679                 return (0);
1680         }
1681         case TIOCGETD:
1682                 /* For compatibility - we only support TTYDISC. */
1683                 *(int *)data = TTYDISC;
1684                 return (0);
1685         case TIOCGPGRP:
1686                 if (!tty_is_ctty(tp, td->td_proc))
1687                         return (ENOTTY);
1688
1689                 if (tp->t_pgrp != NULL)
1690                         *(int *)data = tp->t_pgrp->pg_id;
1691                 else
1692                         *(int *)data = NO_PID;
1693                 return (0);
1694         case TIOCGSID:
1695                 if (!tty_is_ctty(tp, td->td_proc))
1696                         return (ENOTTY);
1697
1698                 MPASS(tp->t_session);
1699                 *(int *)data = tp->t_session->s_sid;
1700                 return (0);
1701         case TIOCSCTTY: {
1702                 struct proc *p = td->td_proc;
1703
1704                 /* XXX: This looks awful. */
1705                 tty_unlock(tp);
1706                 sx_xlock(&proctree_lock);
1707                 tty_lock(tp);
1708
1709                 if (!SESS_LEADER(p)) {
1710                         /* Only the session leader may do this. */
1711                         sx_xunlock(&proctree_lock);
1712                         return (EPERM);
1713                 }
1714
1715                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
1716                         /* This is already our controlling TTY. */
1717                         sx_xunlock(&proctree_lock);
1718                         return (0);
1719                 }
1720
1721                 if (p->p_session->s_ttyp != NULL ||
1722                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1723                     tp->t_session->s_ttyvp->v_type != VBAD)) {
1724                         /*
1725                          * There is already a relation between a TTY and
1726                          * a session, or the caller is not the session
1727                          * leader.
1728                          *
1729                          * Allow the TTY to be stolen when the vnode is
1730                          * invalid, but the reference to the TTY is
1731                          * still active.  This allows immediate reuse of
1732                          * TTYs of which the session leader has been
1733                          * killed or the TTY revoked.
1734                          */
1735                         sx_xunlock(&proctree_lock);
1736                         return (EPERM);
1737                 }
1738
1739                 /* Connect the session to the TTY. */
1740                 tp->t_session = p->p_session;
1741                 tp->t_session->s_ttyp = tp;
1742                 tp->t_sessioncnt++;
1743                 sx_xunlock(&proctree_lock);
1744
1745                 /* Assign foreground process group. */
1746                 tp->t_pgrp = p->p_pgrp;
1747                 PROC_LOCK(p);
1748                 p->p_flag |= P_CONTROLT;
1749                 PROC_UNLOCK(p);
1750
1751                 return (0);
1752         }
1753         case TIOCSPGRP: {
1754                 struct pgrp *pg;
1755
1756                 /*
1757                  * XXX: Temporarily unlock the TTY to locate the process
1758                  * group. This code would be lot nicer if we would ever
1759                  * decompose proctree_lock.
1760                  */
1761                 tty_unlock(tp);
1762                 sx_slock(&proctree_lock);
1763                 pg = pgfind(*(int *)data);
1764                 if (pg != NULL)
1765                         PGRP_UNLOCK(pg);
1766                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1767                         sx_sunlock(&proctree_lock);
1768                         tty_lock(tp);
1769                         return (EPERM);
1770                 }
1771                 tty_lock(tp);
1772
1773                 /*
1774                  * Determine if this TTY is the controlling TTY after
1775                  * relocking the TTY.
1776                  */
1777                 if (!tty_is_ctty(tp, td->td_proc)) {
1778                         sx_sunlock(&proctree_lock);
1779                         return (ENOTTY);
1780                 }
1781                 tp->t_pgrp = pg;
1782                 sx_sunlock(&proctree_lock);
1783
1784                 /* Wake up the background process groups. */
1785                 cv_broadcast(&tp->t_bgwait);
1786                 return (0);
1787         }
1788         case TIOCFLUSH: {
1789                 int flags = *(int *)data;
1790
1791                 if (flags == 0)
1792                         flags = (FREAD|FWRITE);
1793                 else
1794                         flags &= (FREAD|FWRITE);
1795                 tty_flush(tp, flags);
1796                 return (0);
1797         }
1798         case TIOCDRAIN:
1799                 /* Drain TTY output. */
1800                 return tty_drain(tp, 0);
1801         case TIOCGDRAINWAIT:
1802                 *(int *)data = tp->t_drainwait;
1803                 return (0);
1804         case TIOCSDRAINWAIT:
1805                 error = priv_check(td, PRIV_TTY_DRAINWAIT);
1806                 if (error == 0)
1807                         tp->t_drainwait = *(int *)data;
1808                 return (error);
1809         case TIOCCONS:
1810                 /* Set terminal as console TTY. */
1811                 if (*(int *)data) {
1812                         error = priv_check(td, PRIV_TTY_CONSOLE);
1813                         if (error)
1814                                 return (error);
1815
1816                         /*
1817                          * XXX: constty should really need to be locked!
1818                          * XXX: allow disconnected constty's to be stolen!
1819                          */
1820
1821                         if (constty == tp)
1822                                 return (0);
1823                         if (constty != NULL)
1824                                 return (EBUSY);
1825
1826                         tty_unlock(tp);
1827                         constty_set(tp);
1828                         tty_lock(tp);
1829                 } else if (constty == tp) {
1830                         constty_clear();
1831                 }
1832                 return (0);
1833         case TIOCGWINSZ:
1834                 /* Obtain window size. */
1835                 *(struct winsize*)data = tp->t_winsize;
1836                 return (0);
1837         case TIOCSWINSZ:
1838                 /* Set window size. */
1839                 tty_set_winsize(tp, data);
1840                 return (0);
1841         case TIOCEXCL:
1842                 tp->t_flags |= TF_EXCLUDE;
1843                 return (0);
1844         case TIOCNXCL:
1845                 tp->t_flags &= ~TF_EXCLUDE;
1846                 return (0);
1847         case TIOCSTOP:
1848                 tp->t_flags |= TF_STOPPED;
1849                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1850                 return (0);
1851         case TIOCSTART:
1852                 tp->t_flags &= ~TF_STOPPED;
1853                 ttydevsw_outwakeup(tp);
1854                 ttydevsw_pktnotify(tp, TIOCPKT_START);
1855                 return (0);
1856         case TIOCSTAT:
1857                 tty_info(tp);
1858                 return (0);
1859         case TIOCSTI:
1860                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1861                         return (EPERM);
1862                 if (!tty_is_ctty(tp, td->td_proc) &&
1863                     priv_check(td, PRIV_TTY_STI))
1864                         return (EACCES);
1865                 ttydisc_rint(tp, *(char *)data, 0);
1866                 ttydisc_rint_done(tp);
1867                 return (0);
1868         }
1869
1870 #ifdef COMPAT_43TTY
1871         return tty_ioctl_compat(tp, cmd, data, fflag, td);
1872 #else /* !COMPAT_43TTY */
1873         return (ENOIOCTL);
1874 #endif /* COMPAT_43TTY */
1875 }
1876
1877 int
1878 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1879 {
1880         int error;
1881
1882         tty_lock_assert(tp, MA_OWNED);
1883
1884         if (tty_gone(tp))
1885                 return (ENXIO);
1886
1887         error = ttydevsw_ioctl(tp, cmd, data, td);
1888         if (error == ENOIOCTL)
1889                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1890
1891         return (error);
1892 }
1893
1894 dev_t
1895 tty_udev(struct tty *tp)
1896 {
1897
1898         if (tp->t_dev)
1899                 return (dev2udev(tp->t_dev));
1900         else
1901                 return (NODEV);
1902 }
1903
1904 int
1905 tty_checkoutq(struct tty *tp)
1906 {
1907
1908         /* 256 bytes should be enough to print a log message. */
1909         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1910 }
1911
1912 void
1913 tty_hiwat_in_block(struct tty *tp)
1914 {
1915
1916         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1917             tp->t_termios.c_iflag & IXOFF &&
1918             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1919                 /*
1920                  * Input flow control. Only enter the high watermark when we
1921                  * can successfully store the VSTOP character.
1922                  */
1923                 if (ttyoutq_write_nofrag(&tp->t_outq,
1924                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
1925                         tp->t_flags |= TF_HIWAT_IN;
1926         } else {
1927                 /* No input flow control. */
1928                 tp->t_flags |= TF_HIWAT_IN;
1929         }
1930 }
1931
1932 void
1933 tty_hiwat_in_unblock(struct tty *tp)
1934 {
1935
1936         if (tp->t_flags & TF_HIWAT_IN &&
1937             tp->t_termios.c_iflag & IXOFF &&
1938             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1939                 /*
1940                  * Input flow control. Only leave the high watermark when we
1941                  * can successfully store the VSTART character.
1942                  */
1943                 if (ttyoutq_write_nofrag(&tp->t_outq,
1944                     &tp->t_termios.c_cc[VSTART], 1) == 0)
1945                         tp->t_flags &= ~TF_HIWAT_IN;
1946         } else {
1947                 /* No input flow control. */
1948                 tp->t_flags &= ~TF_HIWAT_IN;
1949         }
1950
1951         if (!tty_gone(tp))
1952                 ttydevsw_inwakeup(tp);
1953 }
1954
1955 /*
1956  * TTY hooks interface.
1957  */
1958
1959 static int
1960 ttyhook_defrint(struct tty *tp, char c, int flags)
1961 {
1962
1963         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1964                 return (-1);
1965
1966         return (0);
1967 }
1968
1969 int
1970 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
1971     void *softc)
1972 {
1973         struct tty *tp;
1974         struct file *fp;
1975         struct cdev *dev;
1976         struct cdevsw *cdp;
1977         struct filedesc *fdp;
1978         cap_rights_t rights;
1979         int error, ref;
1980
1981         /* Validate the file descriptor. */
1982         fdp = p->p_fd;
1983         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1984             &fp, NULL);
1985         if (error != 0)
1986                 return (error);
1987         if (fp->f_ops == &badfileops) {
1988                 error = EBADF;
1989                 goto done1;
1990         }
1991
1992         /*
1993          * Make sure the vnode is bound to a character device.
1994          * Unlocked check for the vnode type is ok there, because we
1995          * only shall prevent calling devvn_refthread on the file that
1996          * never has been opened over a character device.
1997          */
1998         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1999                 error = EINVAL;
2000                 goto done1;
2001         }
2002
2003         /* Make sure it is a TTY. */
2004         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
2005         if (cdp == NULL) {
2006                 error = ENXIO;
2007                 goto done1;
2008         }
2009         if (dev != fp->f_data) {
2010                 error = ENXIO;
2011                 goto done2;
2012         }
2013         if (cdp != &ttydev_cdevsw) {
2014                 error = ENOTTY;
2015                 goto done2;
2016         }
2017         tp = dev->si_drv1;
2018
2019         /* Try to attach the hook to the TTY. */
2020         error = EBUSY;
2021         tty_lock(tp);
2022         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
2023         if (tp->t_flags & TF_HOOK)
2024                 goto done3;
2025
2026         tp->t_flags |= TF_HOOK;
2027         tp->t_hook = th;
2028         tp->t_hooksoftc = softc;
2029         *rtp = tp;
2030         error = 0;
2031
2032         /* Maybe we can switch into bypass mode now. */
2033         ttydisc_optimize(tp);
2034
2035         /* Silently convert rint() calls to rint_bypass() when possible. */
2036         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
2037                 th->th_rint = ttyhook_defrint;
2038
2039 done3:  tty_unlock(tp);
2040 done2:  dev_relthread(dev, ref);
2041 done1:  fdrop(fp, curthread);
2042         return (error);
2043 }
2044
2045 void
2046 ttyhook_unregister(struct tty *tp)
2047 {
2048
2049         tty_lock_assert(tp, MA_OWNED);
2050         MPASS(tp->t_flags & TF_HOOK);
2051
2052         /* Disconnect the hook. */
2053         tp->t_flags &= ~TF_HOOK;
2054         tp->t_hook = NULL;
2055
2056         /* Maybe we need to leave bypass mode. */
2057         ttydisc_optimize(tp);
2058
2059         /* Maybe deallocate the TTY as well. */
2060         tty_rel_free(tp);
2061 }
2062
2063 /*
2064  * /dev/console handling.
2065  */
2066
2067 static int
2068 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2069 {
2070         struct tty *tp;
2071
2072         /* System has no console device. */
2073         if (dev_console_filename == NULL)
2074                 return (ENXIO);
2075
2076         /* Look up corresponding TTY by device name. */
2077         sx_slock(&tty_list_sx);
2078         TAILQ_FOREACH(tp, &tty_list, t_list) {
2079                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2080                         dev_console->si_drv1 = tp;
2081                         break;
2082                 }
2083         }
2084         sx_sunlock(&tty_list_sx);
2085
2086         /* System console has no TTY associated. */
2087         if (dev_console->si_drv1 == NULL)
2088                 return (ENXIO);
2089
2090         return (ttydev_open(dev, oflags, devtype, td));
2091 }
2092
2093 static int
2094 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2095 {
2096
2097         log_console(uio);
2098
2099         return (ttydev_write(dev, uio, ioflag));
2100 }
2101
2102 /*
2103  * /dev/console is a little different than normal TTY's.  When opened,
2104  * it determines which TTY to use.  When data gets written to it, it
2105  * will be logged in the kernel message buffer.
2106  */
2107 static struct cdevsw ttyconsdev_cdevsw = {
2108         .d_version      = D_VERSION,
2109         .d_open         = ttyconsdev_open,
2110         .d_close        = ttydev_close,
2111         .d_read         = ttydev_read,
2112         .d_write        = ttyconsdev_write,
2113         .d_ioctl        = ttydev_ioctl,
2114         .d_kqfilter     = ttydev_kqfilter,
2115         .d_poll         = ttydev_poll,
2116         .d_mmap         = ttydev_mmap,
2117         .d_name         = "ttyconsdev",
2118         .d_flags        = D_TTY,
2119 };
2120
2121 static void
2122 ttyconsdev_init(void *unused __unused)
2123 {
2124
2125         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2126             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2127 }
2128
2129 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2130
2131 void
2132 ttyconsdev_select(const char *name)
2133 {
2134
2135         dev_console_filename = name;
2136 }
2137
2138 /*
2139  * Debugging routines.
2140  */
2141
2142 #include "opt_ddb.h"
2143 #ifdef DDB
2144 #include <ddb/ddb.h>
2145 #include <ddb/db_sym.h>
2146
2147 static const struct {
2148         int flag;
2149         char val;
2150 } ttystates[] = {
2151 #if 0
2152         { TF_NOPREFIX,          'N' },
2153 #endif
2154         { TF_INITLOCK,          'I' },
2155         { TF_CALLOUT,           'C' },
2156
2157         /* Keep these together -> 'Oi' and 'Oo'. */
2158         { TF_OPENED,            'O' },
2159         { TF_OPENED_IN,         'i' },
2160         { TF_OPENED_OUT,        'o' },
2161         { TF_OPENED_CONS,       'c' },
2162
2163         { TF_GONE,              'G' },
2164         { TF_OPENCLOSE,         'B' },
2165         { TF_ASYNC,             'Y' },
2166         { TF_LITERAL,           'L' },
2167
2168         /* Keep these together -> 'Hi' and 'Ho'. */
2169         { TF_HIWAT,             'H' },
2170         { TF_HIWAT_IN,          'i' },
2171         { TF_HIWAT_OUT,         'o' },
2172
2173         { TF_STOPPED,           'S' },
2174         { TF_EXCLUDE,           'X' },
2175         { TF_BYPASS,            'l' },
2176         { TF_ZOMBIE,            'Z' },
2177         { TF_HOOK,              's' },
2178
2179         /* Keep these together -> 'bi' and 'bo'. */
2180         { TF_BUSY,              'b' },
2181         { TF_BUSY_IN,           'i' },
2182         { TF_BUSY_OUT,          'o' },
2183
2184         { 0,                    '\0'},
2185 };
2186
2187 #define TTY_FLAG_BITS \
2188         "\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2189         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2190         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2191         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2192         "\21HOOK\22BUSY_IN\23BUSY_OUT"
2193
2194 #define DB_PRINTSYM(name, addr) \
2195         db_printf("%s  " #name ": ", sep); \
2196         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2197         db_printf("\n");
2198
2199 static void
2200 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2201 {
2202
2203         db_printf("%sdevsw: ", sep);
2204         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2205         db_printf(" (%p)\n", tsw);
2206         DB_PRINTSYM(open, tsw->tsw_open);
2207         DB_PRINTSYM(close, tsw->tsw_close);
2208         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2209         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2210         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2211         DB_PRINTSYM(param, tsw->tsw_param);
2212         DB_PRINTSYM(modem, tsw->tsw_modem);
2213         DB_PRINTSYM(mmap, tsw->tsw_mmap);
2214         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2215         DB_PRINTSYM(free, tsw->tsw_free);
2216 }
2217
2218 static void
2219 _db_show_hooks(const char *sep, const struct ttyhook *th)
2220 {
2221
2222         db_printf("%shook: ", sep);
2223         db_printsym((db_addr_t)th, DB_STGY_ANY);
2224         db_printf(" (%p)\n", th);
2225         if (th == NULL)
2226                 return;
2227         DB_PRINTSYM(rint, th->th_rint);
2228         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2229         DB_PRINTSYM(rint_done, th->th_rint_done);
2230         DB_PRINTSYM(rint_poll, th->th_rint_poll);
2231         DB_PRINTSYM(getc_inject, th->th_getc_inject);
2232         DB_PRINTSYM(getc_capture, th->th_getc_capture);
2233         DB_PRINTSYM(getc_poll, th->th_getc_poll);
2234         DB_PRINTSYM(close, th->th_close);
2235 }
2236
2237 static void
2238 _db_show_termios(const char *name, const struct termios *t)
2239 {
2240
2241         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2242             "lflag 0x%x ispeed %u ospeed %u\n", name,
2243             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2244             t->c_ispeed, t->c_ospeed);
2245 }
2246
2247 /* DDB command to show TTY statistics. */
2248 DB_SHOW_COMMAND(tty, db_show_tty)
2249 {
2250         struct tty *tp;
2251
2252         if (!have_addr) {
2253                 db_printf("usage: show tty <addr>\n");
2254                 return;
2255         }
2256         tp = (struct tty *)addr;
2257
2258         db_printf("%p: %s\n", tp, tty_devname(tp));
2259         db_printf("\tmtx: %p\n", tp->t_mtx);
2260         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2261         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2262
2263         /* Buffering mechanisms. */
2264         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2265             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2266             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2267             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2268         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2269             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2270             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2271         db_printf("\tinlow: %zu\n", tp->t_inlow);
2272         db_printf("\toutlow: %zu\n", tp->t_outlow);
2273         _db_show_termios("\ttermios", &tp->t_termios);
2274         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2275             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2276             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2277         db_printf("\tcolumn: %u\n", tp->t_column);
2278         db_printf("\twritepos: %u\n", tp->t_writepos);
2279         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2280
2281         /* Init/lock-state devices. */
2282         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2283         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2284         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2285         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2286
2287         /* Hooks */
2288         _db_show_devsw("\t", tp->t_devsw);
2289         _db_show_hooks("\t", tp->t_hook);
2290
2291         /* Process info. */
2292         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2293             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2294             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2295         db_printf("\tsession: %p", tp->t_session);
2296         if (tp->t_session != NULL)
2297             db_printf(" count %u leader %p tty %p sid %d login %s",
2298                 tp->t_session->s_count, tp->t_session->s_leader,
2299                 tp->t_session->s_ttyp, tp->t_session->s_sid,
2300                 tp->t_session->s_login);
2301         db_printf("\n");
2302         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2303         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2304         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2305         db_printf("\tdev: %p\n", tp->t_dev);
2306 }
2307
2308 /* DDB command to list TTYs. */
2309 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2310 {
2311         struct tty *tp;
2312         size_t isiz, osiz;
2313         int i, j;
2314
2315         /* Make the output look like `pstat -t'. */
2316         db_printf("PTR        ");
2317 #if defined(__LP64__)
2318         db_printf("        ");
2319 #endif
2320         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2321             "COL  SESS  PGID STATE\n");
2322
2323         TAILQ_FOREACH(tp, &tty_list, t_list) {
2324                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2325                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2326
2327                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2328                     "%5d ", tp, tty_devname(tp), isiz,
2329                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2330                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2331                     isiz - tp->t_inlow, osiz,
2332                     tp->t_outq.to_end - tp->t_outq.to_begin,
2333                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2334                     tp->t_session ? tp->t_session->s_sid : 0,
2335                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2336
2337                 /* Flag bits. */
2338                 for (i = j = 0; ttystates[i].flag; i++)
2339                         if (tp->t_flags & ttystates[i].flag) {
2340                                 db_printf("%c", ttystates[i].val);
2341                                 j++;
2342                         }
2343                 if (j == 0)
2344                         db_printf("-");
2345                 db_printf("\n");
2346         }
2347 }
2348 #endif /* DDB */