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 #include "opt_printf.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/capsicum.h>
  40 #include <sys/conf.h>
  41 #include <sys/cons.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/file.h>
  44 #include <sys/filedesc.h>
  45 #include <sys/filio.h>
  46 #ifdef COMPAT_43TTY
  47 #include <sys/ioctl_compat.h>
  48 #endif /* COMPAT_43TTY */
  49 #include <sys/kernel.h>
  50 #include <sys/limits.h>
  51 #include <sys/malloc.h>
  52 #include <sys/mount.h>
  53 #include <sys/poll.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/serial.h>
  57 #include <sys/signal.h>
  58 #include <sys/stat.h>
  59 #include <sys/sx.h>
  60 #include <sys/sysctl.h>
  61 #include <sys/systm.h>
  62 #include <sys/tty.h>
  63 #include <sys/ttycom.h>
  64 #define TTYDEFCHARS
  65 #include <sys/ttydefaults.h>
  66 #undef TTYDEFCHARS
  67 #include <sys/ucred.h>
  68 #include <sys/vnode.h>
  69
  70 #include <machine/stdarg.h>
  71
  72 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
  73
  74 static void tty_rel_free(struct tty *tp);
  75
  76 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
  77 static struct sx tty_list_sx;
  78 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
  79 static unsigned int tty_list_count = 0;
  80
  81 /* Character device of /dev/console. */
  82 static struct cdev      *dev_console;
  83 static const char       *dev_console_filename;
  84
  85 /*
  86  * Flags that are supported and stored by this implementation.
  87  */
  88 #define TTYSUP_IFLAG    (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
  89                         INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
  90 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
  91 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
  92                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
  93                         FLUSHO|NOKERNINFO|NOFLSH)
  94 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
  95                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
  96                         CDSR_OFLOW|CCAR_OFLOW|CNO_RTSDTR)
  97
  98 #define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
  99
 100 static int  tty_drainwait = 5 * 60;
 101 SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
 102     &tty_drainwait, 0, "Default output drain timeout in seconds");
 103
 104 /*
 105  * Set TTY buffer sizes.
 106  */
 107
 108 #define TTYBUF_MAX      65536
 109
 110 #ifdef PRINTF_BUFR_SIZE
 111 #define TTY_PRBUF_SIZE  PRINTF_BUFR_SIZE
 112 #else
 113 #define TTY_PRBUF_SIZE  256
 114 #endif
 115
 116 /*
 117  * Allocate buffer space if necessary, and set low watermarks, based on speed.
 118  * Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
 119  * lock during memory allocation.  They will return ENXIO if the tty disappears
 120  * while unlocked.
 121  */
 122 static int
 123 tty_watermarks(struct tty *tp)
 124 {
 125         size_t bs = 0;
 126         int error;
 127
 128         /* Provide an input buffer for 2 seconds of data. */
 129         if (tp->t_termios.c_cflag & CREAD)
 130                 bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
 131         error = ttyinq_setsize(&tp->t_inq, tp, bs);
 132         if (error != 0)
 133                 return (error);
 134
 135         /* Set low watermark at 10% (when 90% is available). */
 136         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
 137
 138         /* Provide an output buffer for 2 seconds of data. */
 139         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
 140         error = ttyoutq_setsize(&tp->t_outq, tp, bs);
 141         if (error != 0)
 142                 return (error);
 143
 144         /* Set low watermark at 10% (when 90% is available). */
 145         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
 146
 147         return (0);
 148 }
 149
 150 static int
 151 tty_drain(struct tty *tp, int leaving)
 152 {
 153         sbintime_t timeout_at;
 154         size_t bytes;
 155         int error;
 156
 157         if (ttyhook_hashook(tp, getc_inject))
 158                 /* buffer is inaccessible */
 159                 return (0);
 160
 161         /*
 162          * For close(), use the recent historic timeout of "1 second without
 163          * making progress".  For tcdrain(), use t_drainwait as the timeout,
 164          * with zero meaning "no timeout" which gives POSIX behavior.
 165          */
 166         if (leaving)
 167                 timeout_at = getsbinuptime() + SBT_1S;
 168         else if (tp->t_drainwait != 0)
 169                 timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
 170         else
 171                 timeout_at = 0;
 172
 173         /*
 174          * Poll the output buffer and the hardware for completion, at 10 Hz.
 175          * Polling is required for devices which are not able to signal an
 176          * interrupt when the transmitter becomes idle (most USB serial devs).
 177          * The unusual structure of this loop ensures we check for busy one more
 178          * time after tty_timedwait() returns EWOULDBLOCK, so that success has
 179          * higher priority than timeout if the IO completed in the last 100mS.
 180          */
 181         error = 0;
 182         bytes = ttyoutq_bytesused(&tp->t_outq);
 183         for (;;) {
 184                 if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
 185                         return (0);
 186                 if (error != 0)
 187                         return (error);
 188                 ttydevsw_outwakeup(tp);
 189                 error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
 190                 if (error != 0 && error != EWOULDBLOCK)
 191                         return (error);
 192                 else if (timeout_at == 0 || getsbinuptime() < timeout_at)
 193                         error = 0;
 194                 else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
 195                         /* In close, making progress, grant an extra second. */
 196                         error = 0;
 197                         timeout_at += SBT_1S;
 198                         bytes = ttyoutq_bytesused(&tp->t_outq);
 199                 }
 200         }
 201 }
 202
 203 /*
 204  * Though ttydev_enter() and ttydev_leave() seem to be related, they
 205  * don't have to be used together. ttydev_enter() is used by the cdev
 206  * operations to prevent an actual operation from being processed when
 207  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
 208  * and ttydev_close() to determine whether per-TTY data should be
 209  * deallocated.
 210  */
 211
 212 static __inline int
 213 ttydev_enter(struct tty *tp)
 214 {
 215
 216         tty_lock(tp);
 217
 218         if (tty_gone(tp) || !tty_opened(tp)) {
 219                 /* Device is already gone. */
 220                 tty_unlock(tp);
 221                 return (ENXIO);
 222         }
 223
 224         return (0);
 225 }
 226
 227 static void
 228 ttydev_leave(struct tty *tp)
 229 {
 230
 231         tty_lock_assert(tp, MA_OWNED);
 232
 233         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
 234                 /* Device is still opened somewhere. */
 235                 tty_unlock(tp);
 236                 return;
 237         }
 238
 239         tp->t_flags |= TF_OPENCLOSE;
 240
 241         /* Remove console TTY. */
 242         if (constty == tp)
 243                 constty_clear();
 244
 245         /* Drain any output. */
 246         if (!tty_gone(tp))
 247                 tty_drain(tp, 1);
 248
 249         ttydisc_close(tp);
 250
 251         /* Free i/o queues now since they might be large. */
 252         ttyinq_free(&tp->t_inq);
 253         tp->t_inlow = 0;
 254         ttyoutq_free(&tp->t_outq);
 255         tp->t_outlow = 0;
 256
 257         knlist_clear(&tp->t_inpoll.si_note, 1);
 258         knlist_clear(&tp->t_outpoll.si_note, 1);
 259
 260         if (!tty_gone(tp))
 261                 ttydevsw_close(tp);
 262
 263         tp->t_flags &= ~TF_OPENCLOSE;
 264         cv_broadcast(&tp->t_dcdwait);
 265         tty_rel_free(tp);
 266 }
 267
 268 /*
 269  * Operations that are exposed through the character device in /dev.
 270  */
 271 static int
 272 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
 273     struct thread *td)
 274 {
 275         struct tty *tp;
 276         int error;
 277
 278         tp = dev->si_drv1;
 279         error = 0;
 280         tty_lock(tp);
 281         if (tty_gone(tp)) {
 282                 /* Device is already gone. */
 283                 tty_unlock(tp);
 284                 return (ENXIO);
 285         }
 286
 287         /*
 288          * Block when other processes are currently opening or closing
 289          * the TTY.
 290          */
 291         while (tp->t_flags & TF_OPENCLOSE) {
 292                 error = tty_wait(tp, &tp->t_dcdwait);
 293                 if (error != 0) {
 294                         tty_unlock(tp);
 295                         return (error);
 296                 }
 297         }
 298         tp->t_flags |= TF_OPENCLOSE;
 299
 300         /*
 301          * Make sure the "tty" and "cua" device cannot be opened at the
 302          * same time.  The console is a "tty" device.
 303          */
 304         if (TTY_CALLOUT(tp, dev)) {
 305                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
 306                         error = EBUSY;
 307                         goto done;
 308                 }
 309         } else {
 310                 if (tp->t_flags & TF_OPENED_OUT) {
 311                         error = EBUSY;
 312                         goto done;
 313                 }
 314         }
 315
 316         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
 317                 error = EBUSY;
 318                 goto done;
 319         }
 320
 321         if (!tty_opened(tp)) {
 322                 /* Set proper termios flags. */
 323                 if (TTY_CALLOUT(tp, dev))
 324                         tp->t_termios = tp->t_termios_init_out;
 325                 else
 326                         tp->t_termios = tp->t_termios_init_in;
 327                 ttydevsw_param(tp, &tp->t_termios);
 328                 /* Prevent modem control on callout devices and /dev/console. */
 329                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
 330                         tp->t_termios.c_cflag |= CLOCAL;
 331
 332                 if ((tp->t_termios.c_cflag & CNO_RTSDTR) == 0)
 333                         ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
 334
 335                 error = ttydevsw_open(tp);
 336                 if (error != 0)
 337                         goto done;
 338
 339                 ttydisc_open(tp);
 340                 error = tty_watermarks(tp);
 341                 if (error != 0)
 342                         goto done;
 343         }
 344
 345         /* Wait for Carrier Detect. */
 346         if ((oflags & O_NONBLOCK) == 0 &&
 347             (tp->t_termios.c_cflag & CLOCAL) == 0) {
 348                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
 349                         error = tty_wait(tp, &tp->t_dcdwait);
 350                         if (error != 0)
 351                                 goto done;
 352                 }
 353         }
 354
 355         if (dev == dev_console)
 356                 tp->t_flags |= TF_OPENED_CONS;
 357         else if (TTY_CALLOUT(tp, dev))
 358                 tp->t_flags |= TF_OPENED_OUT;
 359         else
 360                 tp->t_flags |= TF_OPENED_IN;
 361         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 362             (tp->t_flags & TF_OPENED_OUT) == 0);
 363
 364 done:   tp->t_flags &= ~TF_OPENCLOSE;
 365         cv_broadcast(&tp->t_dcdwait);
 366         ttydev_leave(tp);
 367
 368         return (error);
 369 }
 370
 371 static int
 372 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
 373     struct thread *td __unused)
 374 {
 375         struct tty *tp = dev->si_drv1;
 376
 377         tty_lock(tp);
 378
 379         /*
 380          * Don't actually close the device if it is being used as the
 381          * console.
 382          */
 383         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 384             (tp->t_flags & TF_OPENED_OUT) == 0);
 385         if (dev == dev_console)
 386                 tp->t_flags &= ~TF_OPENED_CONS;
 387         else
 388                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
 389
 390         if (tp->t_flags & TF_OPENED) {
 391                 tty_unlock(tp);
 392                 return (0);
 393         }
 394
 395         /* If revoking, flush output now to avoid draining it later. */
 396         if (fflag & FREVOKE)
 397                 tty_flush(tp, FWRITE);
 398
 399         tp->t_flags &= ~TF_EXCLUDE;
 400
 401         /* Properly wake up threads that are stuck - revoke(). */
 402         tp->t_revokecnt++;
 403         tty_wakeup(tp, FREAD|FWRITE);
 404         cv_broadcast(&tp->t_bgwait);
 405         cv_broadcast(&tp->t_dcdwait);
 406
 407         ttydev_leave(tp);
 408
 409         return (0);
 410 }
 411
 412 static __inline int
 413 tty_is_ctty(struct tty *tp, struct proc *p)
 414 {
 415
 416         tty_lock_assert(tp, MA_OWNED);
 417
 418         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
 419 }
 420
 421 int
 422 tty_wait_background(struct tty *tp, struct thread *td, int sig)
 423 {
 424         struct proc *p = td->td_proc;
 425         struct pgrp *pg;
 426         ksiginfo_t ksi;
 427         int error;
 428
 429         MPASS(sig == SIGTTIN || sig == SIGTTOU);
 430         tty_lock_assert(tp, MA_OWNED);
 431
 432         for (;;) {
 433                 PROC_LOCK(p);
 434                 /*
 435                  * The process should only sleep, when:
 436                  * - This terminal is the controlling terminal
 437                  * - Its process group is not the foreground process
 438                  *   group
 439                  * - The parent process isn't waiting for the child to
 440                  *   exit
 441                  * - the signal to send to the process isn't masked
 442                  */
 443                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
 444                         /* Allow the action to happen. */
 445                         PROC_UNLOCK(p);
 446                         return (0);
 447                 }
 448
 449                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
 450                     SIGISMEMBER(td->td_sigmask, sig)) {
 451                         /* Only allow them in write()/ioctl(). */
 452                         PROC_UNLOCK(p);
 453                         return (sig == SIGTTOU ? 0 : EIO);
 454                 }
 455
 456                 pg = p->p_pgrp;
 457                 if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
 458                         /* Don't allow the action to happen. */
 459                         PROC_UNLOCK(p);
 460                         return (EIO);
 461                 }
 462                 PROC_UNLOCK(p);
 463
 464                 /*
 465                  * Send the signal and sleep until we're the new
 466                  * foreground process group.
 467                  */
 468                 if (sig != 0) {
 469                         ksiginfo_init(&ksi);
 470                         ksi.ksi_code = SI_KERNEL;
 471                         ksi.ksi_signo = sig;
 472                         sig = 0;
 473                 }
 474                 PGRP_LOCK(pg);
 475                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
 476                 PGRP_UNLOCK(pg);
 477
 478                 error = tty_wait(tp, &tp->t_bgwait);
 479                 if (error)
 480                         return (error);
 481         }
 482 }
 483
 484 static int
 485 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
 486 {
 487         struct tty *tp = dev->si_drv1;
 488         int error;
 489
 490         error = ttydev_enter(tp);
 491         if (error)
 492                 goto done;
 493         error = ttydisc_read(tp, uio, ioflag);
 494         tty_unlock(tp);
 495
 496         /*
 497          * The read() call should not throw an error when the device is
 498          * being destroyed. Silently convert it to an EOF.
 499          */
 500 done:   if (error == ENXIO)
 501                 error = 0;
 502         return (error);
 503 }
 504
 505 static int
 506 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
 507 {
 508         struct tty *tp = dev->si_drv1;
 509         int error;
 510
 511         error = ttydev_enter(tp);
 512         if (error)
 513                 return (error);
 514
 515         if (tp->t_termios.c_lflag & TOSTOP) {
 516                 error = tty_wait_background(tp, curthread, SIGTTOU);
 517                 if (error)
 518                         goto done;
 519         }
 520
 521         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
 522                 /* Allow non-blocking writes to bypass serialization. */
 523                 error = ttydisc_write(tp, uio, ioflag);
 524         } else {
 525                 /* Serialize write() calls. */
 526                 while (tp->t_flags & TF_BUSY_OUT) {
 527                         error = tty_wait(tp, &tp->t_outserwait);
 528                         if (error)
 529                                 goto done;
 530                 }
 531
 532                 tp->t_flags |= TF_BUSY_OUT;
 533                 error = ttydisc_write(tp, uio, ioflag);
 534                 tp->t_flags &= ~TF_BUSY_OUT;
 535                 cv_signal(&tp->t_outserwait);
 536         }
 537
 538 done:   tty_unlock(tp);
 539         return (error);
 540 }
 541
 542 static int
 543 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 544     struct thread *td)
 545 {
 546         struct tty *tp = dev->si_drv1;
 547         int error;
 548
 549         error = ttydev_enter(tp);
 550         if (error)
 551                 return (error);
 552
 553         switch (cmd) {
 554         case TIOCCBRK:
 555         case TIOCCONS:
 556         case TIOCDRAIN:
 557         case TIOCEXCL:
 558         case TIOCFLUSH:
 559         case TIOCNXCL:
 560         case TIOCSBRK:
 561         case TIOCSCTTY:
 562         case TIOCSETA:
 563         case TIOCSETAF:
 564         case TIOCSETAW:
 565         case TIOCSPGRP:
 566         case TIOCSTART:
 567         case TIOCSTAT:
 568         case TIOCSTI:
 569         case TIOCSTOP:
 570         case TIOCSWINSZ:
 571 #if 0
 572         case TIOCSDRAINWAIT:
 573         case TIOCSETD:
 574 #endif
 575 #ifdef COMPAT_43TTY
 576         case  TIOCLBIC:
 577         case  TIOCLBIS:
 578         case  TIOCLSET:
 579         case  TIOCSETC:
 580         case OTIOCSETD:
 581         case  TIOCSETN:
 582         case  TIOCSETP:
 583         case  TIOCSLTC:
 584 #endif /* COMPAT_43TTY */
 585                 /*
 586                  * If the ioctl() causes the TTY to be modified, let it
 587                  * wait in the background.
 588                  */
 589                 error = tty_wait_background(tp, curthread, SIGTTOU);
 590                 if (error)
 591                         goto done;
 592         }
 593
 594         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 595                 struct termios *old = &tp->t_termios;
 596                 struct termios *new = (struct termios *)data;
 597                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
 598                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
 599                 int cc;
 600
 601                 /*
 602                  * Lock state devices.  Just overwrite the values of the
 603                  * commands that are currently in use.
 604                  */
 605                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
 606                     (new->c_iflag & ~lock->c_iflag);
 607                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
 608                     (new->c_oflag & ~lock->c_oflag);
 609                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
 610                     (new->c_cflag & ~lock->c_cflag);
 611                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
 612                     (new->c_lflag & ~lock->c_lflag);
 613                 for (cc = 0; cc < NCCS; ++cc)
 614                         if (lock->c_cc[cc])
 615                                 new->c_cc[cc] = old->c_cc[cc];
 616                 if (lock->c_ispeed)
 617                         new->c_ispeed = old->c_ispeed;
 618                 if (lock->c_ospeed)
 619                         new->c_ospeed = old->c_ospeed;
 620         }
 621
 622         error = tty_ioctl(tp, cmd, data, fflag, td);
 623 done:   tty_unlock(tp);
 624
 625         return (error);
 626 }
 627
 628 static int
 629 ttydev_poll(struct cdev *dev, int events, struct thread *td)
 630 {
 631         struct tty *tp = dev->si_drv1;
 632         int error, revents = 0;
 633
 634         error = ttydev_enter(tp);
 635         if (error)
 636                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
 637
 638         if (events & (POLLIN|POLLRDNORM)) {
 639                 /* See if we can read something. */
 640                 if (ttydisc_read_poll(tp) > 0)
 641                         revents |= events & (POLLIN|POLLRDNORM);
 642         }
 643
 644         if (tp->t_flags & TF_ZOMBIE) {
 645                 /* Hangup flag on zombie state. */
 646                 revents |= POLLHUP;
 647         } else if (events & (POLLOUT|POLLWRNORM)) {
 648                 /* See if we can write something. */
 649                 if (ttydisc_write_poll(tp) > 0)
 650                         revents |= events & (POLLOUT|POLLWRNORM);
 651         }
 652
 653         if (revents == 0) {
 654                 if (events & (POLLIN|POLLRDNORM))
 655                         selrecord(td, &tp->t_inpoll);
 656                 if (events & (POLLOUT|POLLWRNORM))
 657                         selrecord(td, &tp->t_outpoll);
 658         }
 659
 660         tty_unlock(tp);
 661
 662         return (revents);
 663 }
 664
 665 static int
 666 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
 667     int nprot, vm_memattr_t *memattr)
 668 {
 669         struct tty *tp = dev->si_drv1;
 670         int error;
 671
 672         /* Handle mmap() through the driver. */
 673
 674         error = ttydev_enter(tp);
 675         if (error)
 676                 return (-1);
 677         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
 678         tty_unlock(tp);
 679
 680         return (error);
 681 }
 682
 683 /*
 684  * kqueue support.
 685  */
 686
 687 static void
 688 tty_kqops_read_detach(struct knote *kn)
 689 {
 690         struct tty *tp = kn->kn_hook;
 691
 692         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
 693 }
 694
 695 static int
 696 tty_kqops_read_event(struct knote *kn, long hint __unused)
 697 {
 698         struct tty *tp = kn->kn_hook;
 699
 700         tty_lock_assert(tp, MA_OWNED);
 701
 702         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
 703                 kn->kn_flags |= EV_EOF;
 704                 return (1);
 705         } else {
 706                 kn->kn_data = ttydisc_read_poll(tp);
 707                 return (kn->kn_data > 0);
 708         }
 709 }
 710
 711 static void
 712 tty_kqops_write_detach(struct knote *kn)
 713 {
 714         struct tty *tp = kn->kn_hook;
 715
 716         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
 717 }
 718
 719 static int
 720 tty_kqops_write_event(struct knote *kn, long hint __unused)
 721 {
 722         struct tty *tp = kn->kn_hook;
 723
 724         tty_lock_assert(tp, MA_OWNED);
 725
 726         if (tty_gone(tp)) {
 727                 kn->kn_flags |= EV_EOF;
 728                 return (1);
 729         } else {
 730                 kn->kn_data = ttydisc_write_poll(tp);
 731                 return (kn->kn_data > 0);
 732         }
 733 }
 734
 735 static struct filterops tty_kqops_read = {
 736         .f_isfd = 1,
 737         .f_detach = tty_kqops_read_detach,
 738         .f_event = tty_kqops_read_event,
 739 };
 740
 741 static struct filterops tty_kqops_write = {
 742         .f_isfd = 1,
 743         .f_detach = tty_kqops_write_detach,
 744         .f_event = tty_kqops_write_event,
 745 };
 746
 747 static int
 748 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
 749 {
 750         struct tty *tp = dev->si_drv1;
 751         int error;
 752
 753         error = ttydev_enter(tp);
 754         if (error)
 755                 return (error);
 756
 757         switch (kn->kn_filter) {
 758         case EVFILT_READ:
 759                 kn->kn_hook = tp;
 760                 kn->kn_fop = &tty_kqops_read;
 761                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
 762                 break;
 763         case EVFILT_WRITE:
 764                 kn->kn_hook = tp;
 765                 kn->kn_fop = &tty_kqops_write;
 766                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
 767                 break;
 768         default:
 769                 error = EINVAL;
 770                 break;
 771         }
 772
 773         tty_unlock(tp);
 774         return (error);
 775 }
 776
 777 static struct cdevsw ttydev_cdevsw = {
 778         .d_version      = D_VERSION,
 779         .d_open         = ttydev_open,
 780         .d_close        = ttydev_close,
 781         .d_read         = ttydev_read,
 782         .d_write        = ttydev_write,
 783         .d_ioctl        = ttydev_ioctl,
 784         .d_kqfilter     = ttydev_kqfilter,
 785         .d_poll         = ttydev_poll,
 786         .d_mmap         = ttydev_mmap,
 787         .d_name         = "ttydev",
 788         .d_flags        = D_TTY,
 789 };
 790
 791 /*
 792  * Init/lock-state devices
 793  */
 794
 795 static int
 796 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
 797     struct thread *td)
 798 {
 799         struct tty *tp;
 800         int error;
 801
 802         tp = dev->si_drv1;
 803         error = 0;
 804         tty_lock(tp);
 805         if (tty_gone(tp))
 806                 error = ENODEV;
 807         tty_unlock(tp);
 808
 809         return (error);
 810 }
 811
 812 static int
 813 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
 814     struct thread *td __unused)
 815 {
 816
 817         return (0);
 818 }
 819
 820 static int
 821 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
 822     int ioflag __unused)
 823 {
 824
 825         return (ENODEV);
 826 }
 827
 828 static int
 829 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 830     struct thread *td)
 831 {
 832         struct tty *tp = dev->si_drv1;
 833         int error;
 834
 835         tty_lock(tp);
 836         if (tty_gone(tp)) {
 837                 error = ENODEV;
 838                 goto done;
 839         }
 840
 841         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
 842         if (error != ENOIOCTL)
 843                 goto done;
 844         error = 0;
 845
 846         switch (cmd) {
 847         case TIOCGETA:
 848                 /* Obtain terminal flags through tcgetattr(). */
 849                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
 850                 break;
 851         case TIOCSETA:
 852                 /* Set terminal flags through tcsetattr(). */
 853                 error = priv_check(td, PRIV_TTY_SETA);
 854                 if (error)
 855                         break;
 856                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
 857                 break;
 858         case TIOCGETD:
 859                 *(int *)data = TTYDISC;
 860                 break;
 861         case TIOCGWINSZ:
 862                 bzero(data, sizeof(struct winsize));
 863                 break;
 864         default:
 865                 error = ENOTTY;
 866         }
 867
 868 done:   tty_unlock(tp);
 869         return (error);
 870 }
 871
 872 static struct cdevsw ttyil_cdevsw = {
 873         .d_version      = D_VERSION,
 874         .d_open         = ttyil_open,
 875         .d_close        = ttyil_close,
 876         .d_read         = ttyil_rdwr,
 877         .d_write        = ttyil_rdwr,
 878         .d_ioctl        = ttyil_ioctl,
 879         .d_name         = "ttyil",
 880         .d_flags        = D_TTY,
 881 };
 882
 883 static void
 884 tty_init_termios(struct tty *tp)
 885 {
 886         struct termios *t = &tp->t_termios_init_in;
 887
 888         t->c_cflag = TTYDEF_CFLAG;
 889         t->c_iflag = TTYDEF_IFLAG;
 890         t->c_lflag = TTYDEF_LFLAG;
 891         t->c_oflag = TTYDEF_OFLAG;
 892         t->c_ispeed = TTYDEF_SPEED;
 893         t->c_ospeed = TTYDEF_SPEED;
 894         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
 895
 896         tp->t_termios_init_out = *t;
 897 }
 898
 899 void
 900 tty_init_console(struct tty *tp, speed_t s)
 901 {
 902         struct termios *ti = &tp->t_termios_init_in;
 903         struct termios *to = &tp->t_termios_init_out;
 904
 905         if (s != 0) {
 906                 ti->c_ispeed = ti->c_ospeed = s;
 907                 to->c_ispeed = to->c_ospeed = s;
 908         }
 909
 910         ti->c_cflag |= CLOCAL;
 911         to->c_cflag |= CLOCAL;
 912 }
 913
 914 /*
 915  * Standard device routine implementations, mostly meant for
 916  * pseudo-terminal device drivers. When a driver creates a new terminal
 917  * device class, missing routines are patched.
 918  */
 919
 920 static int
 921 ttydevsw_defopen(struct tty *tp __unused)
 922 {
 923
 924         return (0);
 925 }
 926
 927 static void
 928 ttydevsw_defclose(struct tty *tp __unused)
 929 {
 930
 931 }
 932
 933 static void
 934 ttydevsw_defoutwakeup(struct tty *tp __unused)
 935 {
 936
 937         panic("Terminal device has output, while not implemented");
 938 }
 939
 940 static void
 941 ttydevsw_definwakeup(struct tty *tp __unused)
 942 {
 943
 944 }
 945
 946 static int
 947 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
 948     caddr_t data __unused, struct thread *td __unused)
 949 {
 950
 951         return (ENOIOCTL);
 952 }
 953
 954 static int
 955 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
 956     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
 957 {
 958
 959         return (ENOIOCTL);
 960 }
 961
 962 static int
 963 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
 964 {
 965
 966         /*
 967          * Allow the baud rate to be adjusted for pseudo-devices, but at
 968          * least restrict it to 115200 to prevent excessive buffer
 969          * usage.  Also disallow 0, to prevent foot shooting.
 970          */
 971         if (t->c_ispeed < B50)
 972                 t->c_ispeed = B50;
 973         else if (t->c_ispeed > B115200)
 974                 t->c_ispeed = B115200;
 975         if (t->c_ospeed < B50)
 976                 t->c_ospeed = B50;
 977         else if (t->c_ospeed > B115200)
 978                 t->c_ospeed = B115200;
 979         t->c_cflag |= CREAD;
 980
 981         return (0);
 982 }
 983
 984 static int
 985 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
 986     int sigoff __unused)
 987 {
 988
 989         /* Simulate a carrier to make the TTY layer happy. */
 990         return (SER_DCD);
 991 }
 992
 993 static int
 994 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
 995     vm_paddr_t *paddr __unused, int nprot __unused,
 996     vm_memattr_t *memattr __unused)
 997 {
 998
 999         return (-1);
1000 }
1001
1002 static void
1003 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
1004 {
1005
1006 }
1007
1008 static void
1009 ttydevsw_deffree(void *softc __unused)
1010 {
1011
1012         panic("Terminal device freed without a free-handler");
1013 }
1014
1015 static bool
1016 ttydevsw_defbusy(struct tty *tp __unused)
1017 {
1018
1019         return (FALSE);
1020 }
1021
1022 /*
1023  * TTY allocation and deallocation. TTY devices can be deallocated when
1024  * the driver doesn't use it anymore, when the TTY isn't a session's
1025  * controlling TTY and when the device node isn't opened through devfs.
1026  */
1027
1028 struct tty *
1029 tty_alloc(struct ttydevsw *tsw, void *sc)
1030 {
1031
1032         return (tty_alloc_mutex(tsw, sc, NULL));
1033 }
1034
1035 struct tty *
1036 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
1037 {
1038         struct tty *tp;
1039
1040         /* Make sure the driver defines all routines. */
1041 #define PATCH_FUNC(x) do {                              \
1042         if (tsw->tsw_ ## x == NULL)                     \
1043                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
1044 } while (0)
1045         PATCH_FUNC(open);
1046         PATCH_FUNC(close);
1047         PATCH_FUNC(outwakeup);
1048         PATCH_FUNC(inwakeup);
1049         PATCH_FUNC(ioctl);
1050         PATCH_FUNC(cioctl);
1051         PATCH_FUNC(param);
1052         PATCH_FUNC(modem);
1053         PATCH_FUNC(mmap);
1054         PATCH_FUNC(pktnotify);
1055         PATCH_FUNC(free);
1056         PATCH_FUNC(busy);
1057 #undef PATCH_FUNC
1058
1059         tp = malloc(sizeof(struct tty) + TTY_PRBUF_SIZE, M_TTY,
1060             M_WAITOK | M_ZERO);
1061         tp->t_prbufsz = TTY_PRBUF_SIZE;
1062         tp->t_devsw = tsw;
1063         tp->t_devswsoftc = sc;
1064         tp->t_flags = tsw->tsw_flags;
1065         tp->t_drainwait = tty_drainwait;
1066
1067         tty_init_termios(tp);
1068
1069         cv_init(&tp->t_inwait, "ttyin");
1070         cv_init(&tp->t_outwait, "ttyout");
1071         cv_init(&tp->t_outserwait, "ttyosr");
1072         cv_init(&tp->t_bgwait, "ttybg");
1073         cv_init(&tp->t_dcdwait, "ttydcd");
1074
1075         /* Allow drivers to use a custom mutex to lock the TTY. */
1076         if (mutex != NULL) {
1077                 tp->t_mtx = mutex;
1078         } else {
1079                 tp->t_mtx = &tp->t_mtxobj;
1080                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1081         }
1082
1083         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1084         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1085
1086         return (tp);
1087 }
1088
1089 static void
1090 tty_dealloc(void *arg)
1091 {
1092         struct tty *tp = arg;
1093
1094         /*
1095          * ttyydev_leave() usually frees the i/o queues earlier, but it is
1096          * not always called between queue allocation and here.  The queues
1097          * may be allocated by ioctls on a pty control device without the
1098          * corresponding pty slave device ever being open, or after it is
1099          * closed.
1100          */
1101         ttyinq_free(&tp->t_inq);
1102         ttyoutq_free(&tp->t_outq);
1103         seldrain(&tp->t_inpoll);
1104         seldrain(&tp->t_outpoll);
1105         knlist_destroy(&tp->t_inpoll.si_note);
1106         knlist_destroy(&tp->t_outpoll.si_note);
1107
1108         cv_destroy(&tp->t_inwait);
1109         cv_destroy(&tp->t_outwait);
1110         cv_destroy(&tp->t_bgwait);
1111         cv_destroy(&tp->t_dcdwait);
1112         cv_destroy(&tp->t_outserwait);
1113
1114         if (tp->t_mtx == &tp->t_mtxobj)
1115                 mtx_destroy(&tp->t_mtxobj);
1116         ttydevsw_free(tp);
1117         free(tp, M_TTY);
1118 }
1119
1120 static void
1121 tty_rel_free(struct tty *tp)
1122 {
1123         struct cdev *dev;
1124
1125         tty_lock_assert(tp, MA_OWNED);
1126
1127 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1128         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1129                 /* TTY is still in use. */
1130                 tty_unlock(tp);
1131                 return;
1132         }
1133
1134         /* Stop asynchronous I/O. */
1135         funsetown(&tp->t_sigio);
1136
1137         /* TTY can be deallocated. */
1138         dev = tp->t_dev;
1139         tp->t_dev = NULL;
1140         tty_unlock(tp);
1141
1142         if (dev != NULL) {
1143                 sx_xlock(&tty_list_sx);
1144                 TAILQ_REMOVE(&tty_list, tp, t_list);
1145                 tty_list_count--;
1146                 sx_xunlock(&tty_list_sx);
1147                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
1148         }
1149 }
1150
1151 void
1152 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1153 {
1154
1155         MPASS(tp->t_sessioncnt > 0);
1156         tty_lock_assert(tp, MA_OWNED);
1157
1158         if (tp->t_pgrp == pg)
1159                 tp->t_pgrp = NULL;
1160
1161         tty_unlock(tp);
1162 }
1163
1164 void
1165 tty_rel_sess(struct tty *tp, struct session *sess)
1166 {
1167
1168         MPASS(tp->t_sessioncnt > 0);
1169
1170         /* Current session has left. */
1171         if (tp->t_session == sess) {
1172                 tp->t_session = NULL;
1173                 MPASS(tp->t_pgrp == NULL);
1174         }
1175         tp->t_sessioncnt--;
1176         tty_rel_free(tp);
1177 }
1178
1179 void
1180 tty_rel_gone(struct tty *tp)
1181 {
1182
1183         tty_lock_assert(tp, MA_OWNED);
1184         MPASS(!tty_gone(tp));
1185
1186         /* Simulate carrier removal. */
1187         ttydisc_modem(tp, 0);
1188
1189         /* Wake up all blocked threads. */
1190         tty_wakeup(tp, FREAD|FWRITE);
1191         cv_broadcast(&tp->t_bgwait);
1192         cv_broadcast(&tp->t_dcdwait);
1193
1194         tp->t_flags |= TF_GONE;
1195         tty_rel_free(tp);
1196 }
1197
1198 /*
1199  * Exposing information about current TTY's through sysctl
1200  */
1201
1202 static void
1203 tty_to_xtty(struct tty *tp, struct xtty *xt)
1204 {
1205
1206         tty_lock_assert(tp, MA_OWNED);
1207
1208         xt->xt_size = sizeof(struct xtty);
1209         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1210         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1211         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1212         xt->xt_inlow = tp->t_inlow;
1213         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1214         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1215         xt->xt_outlow = tp->t_outlow;
1216         xt->xt_column = tp->t_column;
1217         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1218         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1219         xt->xt_flags = tp->t_flags;
1220         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : (uint32_t)NODEV;
1221 }
1222
1223 static int
1224 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1225 {
1226         unsigned long lsize;
1227         struct xtty *xtlist, *xt;
1228         struct tty *tp;
1229         int error;
1230
1231         sx_slock(&tty_list_sx);
1232         lsize = tty_list_count * sizeof(struct xtty);
1233         if (lsize == 0) {
1234                 sx_sunlock(&tty_list_sx);
1235                 return (0);
1236         }
1237
1238         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1239
1240         TAILQ_FOREACH(tp, &tty_list, t_list) {
1241                 tty_lock(tp);
1242                 tty_to_xtty(tp, xt);
1243                 tty_unlock(tp);
1244                 xt++;
1245         }
1246         sx_sunlock(&tty_list_sx);
1247
1248         error = SYSCTL_OUT(req, xtlist, lsize);
1249         free(xtlist, M_TTY);
1250         return (error);
1251 }
1252
1253 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1254         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1255
1256 /*
1257  * Device node creation. Device has been set up, now we can expose it to
1258  * the user.
1259  */
1260
1261 int
1262 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1263     const char *fmt, ...)
1264 {
1265         va_list ap;
1266         struct make_dev_args args;
1267         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1268         const char *prefix = "tty";
1269         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1270         uid_t uid;
1271         gid_t gid;
1272         mode_t mode;
1273         int error;
1274
1275         /* Remove "tty" prefix from devices like PTY's. */
1276         if (tp->t_flags & TF_NOPREFIX)
1277                 prefix = "";
1278
1279         va_start(ap, fmt);
1280         vsnrprintf(name, sizeof name, 32, fmt, ap);
1281         va_end(ap);
1282
1283         if (cred == NULL) {
1284                 /* System device. */
1285                 uid = UID_ROOT;
1286                 gid = GID_WHEEL;
1287                 mode = S_IRUSR|S_IWUSR;
1288         } else {
1289                 /* User device. */
1290                 uid = cred->cr_ruid;
1291                 gid = GID_TTY;
1292                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
1293         }
1294
1295         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1296         flags |= MAKEDEV_CHECKNAME;
1297
1298         /* Master call-in device. */
1299         make_dev_args_init(&args);
1300         args.mda_flags = flags;
1301         args.mda_devsw = &ttydev_cdevsw;
1302         args.mda_cr = cred;
1303         args.mda_uid = uid;
1304         args.mda_gid = gid;
1305         args.mda_mode = mode;
1306         args.mda_si_drv1 = tp;
1307         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1308         if (error != 0)
1309                 return (error);
1310         tp->t_dev = dev;
1311
1312         init = lock = cua = cinit = clock = NULL;
1313
1314         /* Slave call-in devices. */
1315         if (tp->t_flags & TF_INITLOCK) {
1316                 args.mda_devsw = &ttyil_cdevsw;
1317                 args.mda_unit = TTYUNIT_INIT;
1318                 args.mda_si_drv1 = tp;
1319                 args.mda_si_drv2 = &tp->t_termios_init_in;
1320                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1321                 if (error != 0)
1322                         goto fail;
1323                 dev_depends(dev, init);
1324
1325                 args.mda_unit = TTYUNIT_LOCK;
1326                 args.mda_si_drv2 = &tp->t_termios_lock_in;
1327                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1328                 if (error != 0)
1329                         goto fail;
1330                 dev_depends(dev, lock);
1331         }
1332
1333         /* Call-out devices. */
1334         if (tp->t_flags & TF_CALLOUT) {
1335                 make_dev_args_init(&args);
1336                 args.mda_flags = flags;
1337                 args.mda_devsw = &ttydev_cdevsw;
1338                 args.mda_cr = cred;
1339                 args.mda_uid = UID_UUCP;
1340                 args.mda_gid = GID_DIALER;
1341                 args.mda_mode = 0660;
1342                 args.mda_unit = TTYUNIT_CALLOUT;
1343                 args.mda_si_drv1 = tp;
1344                 error = make_dev_s(&args, &cua, "cua%s", name);
1345                 if (error != 0)
1346                         goto fail;
1347                 dev_depends(dev, cua);
1348
1349                 /* Slave call-out devices. */
1350                 if (tp->t_flags & TF_INITLOCK) {
1351                         args.mda_devsw = &ttyil_cdevsw;
1352                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1353                         args.mda_si_drv2 = &tp->t_termios_init_out;
1354                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
1355                         if (error != 0)
1356                                 goto fail;
1357                         dev_depends(dev, cinit);
1358
1359                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1360                         args.mda_si_drv2 = &tp->t_termios_lock_out;
1361                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
1362                         if (error != 0)
1363                                 goto fail;
1364                         dev_depends(dev, clock);
1365                 }
1366         }
1367
1368         sx_xlock(&tty_list_sx);
1369         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1370         tty_list_count++;
1371         sx_xunlock(&tty_list_sx);
1372
1373         return (0);
1374
1375 fail:
1376         destroy_dev(dev);
1377         if (init)
1378                 destroy_dev(init);
1379         if (lock)
1380                 destroy_dev(lock);
1381         if (cinit)
1382                 destroy_dev(cinit);
1383         if (clock)
1384                 destroy_dev(clock);
1385
1386         return (error);
1387 }
1388
1389 /*
1390  * Signalling processes.
1391  */
1392
1393 void
1394 tty_signal_sessleader(struct tty *tp, int sig)
1395 {
1396         struct proc *p;
1397
1398         tty_lock_assert(tp, MA_OWNED);
1399         MPASS(sig >= 1 && sig < NSIG);
1400
1401         /* Make signals start output again. */
1402         tp->t_flags &= ~TF_STOPPED;
1403
1404         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1405                 p = tp->t_session->s_leader;
1406                 PROC_LOCK(p);
1407                 kern_psignal(p, sig);
1408                 PROC_UNLOCK(p);
1409         }
1410 }
1411
1412 void
1413 tty_signal_pgrp(struct tty *tp, int sig)
1414 {
1415         ksiginfo_t ksi;
1416
1417         tty_lock_assert(tp, MA_OWNED);
1418         MPASS(sig >= 1 && sig < NSIG);
1419
1420         /* Make signals start output again. */
1421         tp->t_flags &= ~TF_STOPPED;
1422
1423         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1424                 tty_info(tp);
1425         if (tp->t_pgrp != NULL) {
1426                 ksiginfo_init(&ksi);
1427                 ksi.ksi_signo = sig;
1428                 ksi.ksi_code = SI_KERNEL;
1429                 PGRP_LOCK(tp->t_pgrp);
1430                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
1431                 PGRP_UNLOCK(tp->t_pgrp);
1432         }
1433 }
1434
1435 void
1436 tty_wakeup(struct tty *tp, int flags)
1437 {
1438
1439         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1440                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1441
1442         if (flags & FWRITE) {
1443                 cv_broadcast(&tp->t_outwait);
1444                 selwakeup(&tp->t_outpoll);
1445                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1446         }
1447         if (flags & FREAD) {
1448                 cv_broadcast(&tp->t_inwait);
1449                 selwakeup(&tp->t_inpoll);
1450                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1451         }
1452 }
1453
1454 int
1455 tty_wait(struct tty *tp, struct cv *cv)
1456 {
1457         int error;
1458         int revokecnt = tp->t_revokecnt;
1459
1460         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1461         MPASS(!tty_gone(tp));
1462
1463         error = cv_wait_sig(cv, tp->t_mtx);
1464
1465         /* Bail out when the device slipped away. */
1466         if (tty_gone(tp))
1467                 return (ENXIO);
1468
1469         /* Restart the system call when we may have been revoked. */
1470         if (tp->t_revokecnt != revokecnt)
1471                 return (ERESTART);
1472
1473         return (error);
1474 }
1475
1476 int
1477 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1478 {
1479         int error;
1480         int revokecnt = tp->t_revokecnt;
1481
1482         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1483         MPASS(!tty_gone(tp));
1484
1485         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1486
1487         /* Bail out when the device slipped away. */
1488         if (tty_gone(tp))
1489                 return (ENXIO);
1490
1491         /* Restart the system call when we may have been revoked. */
1492         if (tp->t_revokecnt != revokecnt)
1493                 return (ERESTART);
1494
1495         return (error);
1496 }
1497
1498 void
1499 tty_flush(struct tty *tp, int flags)
1500 {
1501
1502         if (flags & FWRITE) {
1503                 tp->t_flags &= ~TF_HIWAT_OUT;
1504                 ttyoutq_flush(&tp->t_outq);
1505                 tty_wakeup(tp, FWRITE);
1506                 if (!tty_gone(tp)) {
1507                         ttydevsw_outwakeup(tp);
1508                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1509                 }
1510         }
1511         if (flags & FREAD) {
1512                 tty_hiwat_in_unblock(tp);
1513                 ttyinq_flush(&tp->t_inq);
1514                 tty_wakeup(tp, FREAD);
1515                 if (!tty_gone(tp)) {
1516                         ttydevsw_inwakeup(tp);
1517                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1518                 }
1519         }
1520 }
1521
1522 void
1523 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1524 {
1525
1526         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1527                 return;
1528         tp->t_winsize = *wsz;
1529         tty_signal_pgrp(tp, SIGWINCH);
1530 }
1531
1532 static int
1533 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1534     struct thread *td)
1535 {
1536         int error;
1537
1538         switch (cmd) {
1539         /*
1540          * Modem commands.
1541          * The SER_* and TIOCM_* flags are the same, but one bit
1542          * shifted. I don't know why.
1543          */
1544         case TIOCSDTR:
1545                 ttydevsw_modem(tp, SER_DTR, 0);
1546                 return (0);
1547         case TIOCCDTR:
1548                 ttydevsw_modem(tp, 0, SER_DTR);
1549                 return (0);
1550         case TIOCMSET: {
1551                 int bits = *(int *)data;
1552                 ttydevsw_modem(tp,
1553                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1554                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1555                 return (0);
1556         }
1557         case TIOCMBIS: {
1558                 int bits = *(int *)data;
1559                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1560                 return (0);
1561         }
1562         case TIOCMBIC: {
1563                 int bits = *(int *)data;
1564                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1565                 return (0);
1566         }
1567         case TIOCMGET:
1568                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1569                 return (0);
1570
1571         case FIOASYNC:
1572                 if (*(int *)data)
1573                         tp->t_flags |= TF_ASYNC;
1574                 else
1575                         tp->t_flags &= ~TF_ASYNC;
1576                 return (0);
1577         case FIONBIO:
1578                 /* This device supports non-blocking operation. */
1579                 return (0);
1580         case FIONREAD:
1581                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1582                 return (0);
1583         case FIONWRITE:
1584         case TIOCOUTQ:
1585                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
1586                 return (0);
1587         case FIOSETOWN:
1588                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1589                         /* Not allowed to set ownership. */
1590                         return (ENOTTY);
1591
1592                 /* Temporarily unlock the TTY to set ownership. */
1593                 tty_unlock(tp);
1594                 error = fsetown(*(int *)data, &tp->t_sigio);
1595                 tty_lock(tp);
1596                 return (error);
1597         case FIOGETOWN:
1598                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1599                         /* Not allowed to set ownership. */
1600                         return (ENOTTY);
1601
1602                 /* Get ownership. */
1603                 *(int *)data = fgetown(&tp->t_sigio);
1604                 return (0);
1605         case TIOCGETA:
1606                 /* Obtain terminal flags through tcgetattr(). */
1607                 *(struct termios*)data = tp->t_termios;
1608                 return (0);
1609         case TIOCSETA:
1610         case TIOCSETAW:
1611         case TIOCSETAF: {
1612                 struct termios *t = data;
1613
1614                 /*
1615                  * Who makes up these funny rules? According to POSIX,
1616                  * input baud rate is set equal to the output baud rate
1617                  * when zero.
1618                  */
1619                 if (t->c_ispeed == 0)
1620                         t->c_ispeed = t->c_ospeed;
1621
1622                 /* Discard any unsupported bits. */
1623                 t->c_iflag &= TTYSUP_IFLAG;
1624                 t->c_oflag &= TTYSUP_OFLAG;
1625                 t->c_lflag &= TTYSUP_LFLAG;
1626                 t->c_cflag &= TTYSUP_CFLAG;
1627
1628                 /* Set terminal flags through tcsetattr(). */
1629                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1630                         error = tty_drain(tp, 0);
1631                         if (error)
1632                                 return (error);
1633                         if (cmd == TIOCSETAF)
1634                                 tty_flush(tp, FREAD);
1635                 }
1636
1637                 /*
1638                  * Only call param() when the flags really change.
1639                  */
1640                 if ((t->c_cflag & CIGNORE) == 0 &&
1641                     (tp->t_termios.c_cflag != t->c_cflag ||
1642                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
1643                     (IXON|IXOFF|IXANY)) ||
1644                     tp->t_termios.c_ispeed != t->c_ispeed ||
1645                     tp->t_termios.c_ospeed != t->c_ospeed)) {
1646                         error = ttydevsw_param(tp, t);
1647                         if (error)
1648                                 return (error);
1649
1650                         /* XXX: CLOCAL? */
1651
1652                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1653                         tp->t_termios.c_ispeed = t->c_ispeed;
1654                         tp->t_termios.c_ospeed = t->c_ospeed;
1655
1656                         /* Baud rate has changed - update watermarks. */
1657                         error = tty_watermarks(tp);
1658                         if (error)
1659                                 return (error);
1660                 }
1661
1662                 /* Copy new non-device driver parameters. */
1663                 tp->t_termios.c_iflag = t->c_iflag;
1664                 tp->t_termios.c_oflag = t->c_oflag;
1665                 tp->t_termios.c_lflag = t->c_lflag;
1666                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1667
1668                 ttydisc_optimize(tp);
1669
1670                 if ((t->c_lflag & ICANON) == 0) {
1671                         /*
1672                          * When in non-canonical mode, wake up all
1673                          * readers. Canonicalize any partial input. VMIN
1674                          * and VTIME could also be adjusted.
1675                          */
1676                         ttyinq_canonicalize(&tp->t_inq);
1677                         tty_wakeup(tp, FREAD);
1678                 }
1679
1680                 /*
1681                  * For packet mode: notify the PTY consumer that VSTOP
1682                  * and VSTART may have been changed.
1683                  */
1684                 if (tp->t_termios.c_iflag & IXON &&
1685                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1686                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1687                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1688                 else
1689                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1690                 return (0);
1691         }
1692         case TIOCGETD:
1693                 /* For compatibility - we only support TTYDISC. */
1694                 *(int *)data = TTYDISC;
1695                 return (0);
1696         case TIOCGPGRP:
1697                 if (!tty_is_ctty(tp, td->td_proc))
1698                         return (ENOTTY);
1699
1700                 if (tp->t_pgrp != NULL)
1701                         *(int *)data = tp->t_pgrp->pg_id;
1702                 else
1703                         *(int *)data = NO_PID;
1704                 return (0);
1705         case TIOCGSID:
1706                 if (!tty_is_ctty(tp, td->td_proc))
1707                         return (ENOTTY);
1708
1709                 MPASS(tp->t_session);
1710                 *(int *)data = tp->t_session->s_sid;
1711                 return (0);
1712         case TIOCSCTTY: {
1713                 struct proc *p = td->td_proc;
1714
1715                 /* XXX: This looks awful. */
1716                 tty_unlock(tp);
1717                 sx_xlock(&proctree_lock);
1718                 tty_lock(tp);
1719
1720                 if (!SESS_LEADER(p)) {
1721                         /* Only the session leader may do this. */
1722                         sx_xunlock(&proctree_lock);
1723                         return (EPERM);
1724                 }
1725
1726                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
1727                         /* This is already our controlling TTY. */
1728                         sx_xunlock(&proctree_lock);
1729                         return (0);
1730                 }
1731
1732                 if (p->p_session->s_ttyp != NULL ||
1733                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1734                     tp->t_session->s_ttyvp->v_type != VBAD)) {
1735                         /*
1736                          * There is already a relation between a TTY and
1737                          * a session, or the caller is not the session
1738                          * leader.
1739                          *
1740                          * Allow the TTY to be stolen when the vnode is
1741                          * invalid, but the reference to the TTY is
1742                          * still active.  This allows immediate reuse of
1743                          * TTYs of which the session leader has been
1744                          * killed or the TTY revoked.
1745                          */
1746                         sx_xunlock(&proctree_lock);
1747                         return (EPERM);
1748                 }
1749
1750                 /* Connect the session to the TTY. */
1751                 tp->t_session = p->p_session;
1752                 tp->t_session->s_ttyp = tp;
1753                 tp->t_sessioncnt++;
1754                 sx_xunlock(&proctree_lock);
1755
1756                 /* Assign foreground process group. */
1757                 tp->t_pgrp = p->p_pgrp;
1758                 PROC_LOCK(p);
1759                 p->p_flag |= P_CONTROLT;
1760                 PROC_UNLOCK(p);
1761
1762                 return (0);
1763         }
1764         case TIOCSPGRP: {
1765                 struct pgrp *pg;
1766
1767                 /*
1768                  * XXX: Temporarily unlock the TTY to locate the process
1769                  * group. This code would be lot nicer if we would ever
1770                  * decompose proctree_lock.
1771                  */
1772                 tty_unlock(tp);
1773                 sx_slock(&proctree_lock);
1774                 pg = pgfind(*(int *)data);
1775                 if (pg != NULL)
1776                         PGRP_UNLOCK(pg);
1777                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1778                         sx_sunlock(&proctree_lock);
1779                         tty_lock(tp);
1780                         return (EPERM);
1781                 }
1782                 tty_lock(tp);
1783
1784                 /*
1785                  * Determine if this TTY is the controlling TTY after
1786                  * relocking the TTY.
1787                  */
1788                 if (!tty_is_ctty(tp, td->td_proc)) {
1789                         sx_sunlock(&proctree_lock);
1790                         return (ENOTTY);
1791                 }
1792                 tp->t_pgrp = pg;
1793                 sx_sunlock(&proctree_lock);
1794
1795                 /* Wake up the background process groups. */
1796                 cv_broadcast(&tp->t_bgwait);
1797                 return (0);
1798         }
1799         case TIOCFLUSH: {
1800                 int flags = *(int *)data;
1801
1802                 if (flags == 0)
1803                         flags = (FREAD|FWRITE);
1804                 else
1805                         flags &= (FREAD|FWRITE);
1806                 tty_flush(tp, flags);
1807                 return (0);
1808         }
1809         case TIOCDRAIN:
1810                 /* Drain TTY output. */
1811                 return tty_drain(tp, 0);
1812         case TIOCGDRAINWAIT:
1813                 *(int *)data = tp->t_drainwait;
1814                 return (0);
1815         case TIOCSDRAINWAIT:
1816                 error = priv_check(td, PRIV_TTY_DRAINWAIT);
1817                 if (error == 0)
1818                         tp->t_drainwait = *(int *)data;
1819                 return (error);
1820         case TIOCCONS:
1821                 /* Set terminal as console TTY. */
1822                 if (*(int *)data) {
1823                         error = priv_check(td, PRIV_TTY_CONSOLE);
1824                         if (error)
1825                                 return (error);
1826
1827                         /*
1828                          * XXX: constty should really need to be locked!
1829                          * XXX: allow disconnected constty's to be stolen!
1830                          */
1831
1832                         if (constty == tp)
1833                                 return (0);
1834                         if (constty != NULL)
1835                                 return (EBUSY);
1836
1837                         tty_unlock(tp);
1838                         constty_set(tp);
1839                         tty_lock(tp);
1840                 } else if (constty == tp) {
1841                         constty_clear();
1842                 }
1843                 return (0);
1844         case TIOCGWINSZ:
1845                 /* Obtain window size. */
1846                 *(struct winsize*)data = tp->t_winsize;
1847                 return (0);
1848         case TIOCSWINSZ:
1849                 /* Set window size. */
1850                 tty_set_winsize(tp, data);
1851                 return (0);
1852         case TIOCEXCL:
1853                 tp->t_flags |= TF_EXCLUDE;
1854                 return (0);
1855         case TIOCNXCL:
1856                 tp->t_flags &= ~TF_EXCLUDE;
1857                 return (0);
1858         case TIOCSTOP:
1859                 tp->t_flags |= TF_STOPPED;
1860                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1861                 return (0);
1862         case TIOCSTART:
1863                 tp->t_flags &= ~TF_STOPPED;
1864                 ttydevsw_outwakeup(tp);
1865                 ttydevsw_pktnotify(tp, TIOCPKT_START);
1866                 return (0);
1867         case TIOCSTAT:
1868                 tty_info(tp);
1869                 return (0);
1870         case TIOCSTI:
1871                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1872                         return (EPERM);
1873                 if (!tty_is_ctty(tp, td->td_proc) &&
1874                     priv_check(td, PRIV_TTY_STI))
1875                         return (EACCES);
1876                 ttydisc_rint(tp, *(char *)data, 0);
1877                 ttydisc_rint_done(tp);
1878                 return (0);
1879         }
1880
1881 #ifdef COMPAT_43TTY
1882         return tty_ioctl_compat(tp, cmd, data, fflag, td);
1883 #else /* !COMPAT_43TTY */
1884         return (ENOIOCTL);
1885 #endif /* COMPAT_43TTY */
1886 }
1887
1888 int
1889 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1890 {
1891         int error;
1892
1893         tty_lock_assert(tp, MA_OWNED);
1894
1895         if (tty_gone(tp))
1896                 return (ENXIO);
1897
1898         error = ttydevsw_ioctl(tp, cmd, data, td);
1899         if (error == ENOIOCTL)
1900                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1901
1902         return (error);
1903 }
1904
1905 dev_t
1906 tty_udev(struct tty *tp)
1907 {
1908
1909         if (tp->t_dev)
1910                 return (dev2udev(tp->t_dev));
1911         else
1912                 return (NODEV);
1913 }
1914
1915 int
1916 tty_checkoutq(struct tty *tp)
1917 {
1918
1919         /* 256 bytes should be enough to print a log message. */
1920         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1921 }
1922
1923 void
1924 tty_hiwat_in_block(struct tty *tp)
1925 {
1926
1927         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1928             tp->t_termios.c_iflag & IXOFF &&
1929             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1930                 /*
1931                  * Input flow control. Only enter the high watermark when we
1932                  * can successfully store the VSTOP character.
1933                  */
1934                 if (ttyoutq_write_nofrag(&tp->t_outq,
1935                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
1936                         tp->t_flags |= TF_HIWAT_IN;
1937         } else {
1938                 /* No input flow control. */
1939                 tp->t_flags |= TF_HIWAT_IN;
1940         }
1941 }
1942
1943 void
1944 tty_hiwat_in_unblock(struct tty *tp)
1945 {
1946
1947         if (tp->t_flags & TF_HIWAT_IN &&
1948             tp->t_termios.c_iflag & IXOFF &&
1949             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1950                 /*
1951                  * Input flow control. Only leave the high watermark when we
1952                  * can successfully store the VSTART character.
1953                  */
1954                 if (ttyoutq_write_nofrag(&tp->t_outq,
1955                     &tp->t_termios.c_cc[VSTART], 1) == 0)
1956                         tp->t_flags &= ~TF_HIWAT_IN;
1957         } else {
1958                 /* No input flow control. */
1959                 tp->t_flags &= ~TF_HIWAT_IN;
1960         }
1961
1962         if (!tty_gone(tp))
1963                 ttydevsw_inwakeup(tp);
1964 }
1965
1966 /*
1967  * TTY hooks interface.
1968  */
1969
1970 static int
1971 ttyhook_defrint(struct tty *tp, char c, int flags)
1972 {
1973
1974         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1975                 return (-1);
1976
1977         return (0);
1978 }
1979
1980 int
1981 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
1982     void *softc)
1983 {
1984         struct tty *tp;
1985         struct file *fp;
1986         struct cdev *dev;
1987         struct cdevsw *cdp;
1988         struct filedesc *fdp;
1989         cap_rights_t rights;
1990         int error, ref;
1991
1992         /* Validate the file descriptor. */
1993         fdp = p->p_fd;
1994         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1995             &fp, NULL);
1996         if (error != 0)
1997                 return (error);
1998         if (fp->f_ops == &badfileops) {
1999                 error = EBADF;
2000                 goto done1;
2001         }
2002
2003         /*
2004          * Make sure the vnode is bound to a character device.
2005          * Unlocked check for the vnode type is ok there, because we
2006          * only shall prevent calling devvn_refthread on the file that
2007          * never has been opened over a character device.
2008          */
2009         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
2010                 error = EINVAL;
2011                 goto done1;
2012         }
2013
2014         /* Make sure it is a TTY. */
2015         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
2016         if (cdp == NULL) {
2017                 error = ENXIO;
2018                 goto done1;
2019         }
2020         if (dev != fp->f_data) {
2021                 error = ENXIO;
2022                 goto done2;
2023         }
2024         if (cdp != &ttydev_cdevsw) {
2025                 error = ENOTTY;
2026                 goto done2;
2027         }
2028         tp = dev->si_drv1;
2029
2030         /* Try to attach the hook to the TTY. */
2031         error = EBUSY;
2032         tty_lock(tp);
2033         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
2034         if (tp->t_flags & TF_HOOK)
2035                 goto done3;
2036
2037         tp->t_flags |= TF_HOOK;
2038         tp->t_hook = th;
2039         tp->t_hooksoftc = softc;
2040         *rtp = tp;
2041         error = 0;
2042
2043         /* Maybe we can switch into bypass mode now. */
2044         ttydisc_optimize(tp);
2045
2046         /* Silently convert rint() calls to rint_bypass() when possible. */
2047         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
2048                 th->th_rint = ttyhook_defrint;
2049
2050 done3:  tty_unlock(tp);
2051 done2:  dev_relthread(dev, ref);
2052 done1:  fdrop(fp, curthread);
2053         return (error);
2054 }
2055
2056 void
2057 ttyhook_unregister(struct tty *tp)
2058 {
2059
2060         tty_lock_assert(tp, MA_OWNED);
2061         MPASS(tp->t_flags & TF_HOOK);
2062
2063         /* Disconnect the hook. */
2064         tp->t_flags &= ~TF_HOOK;
2065         tp->t_hook = NULL;
2066
2067         /* Maybe we need to leave bypass mode. */
2068         ttydisc_optimize(tp);
2069
2070         /* Maybe deallocate the TTY as well. */
2071         tty_rel_free(tp);
2072 }
2073
2074 /*
2075  * /dev/console handling.
2076  */
2077
2078 static int
2079 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2080 {
2081         struct tty *tp;
2082
2083         /* System has no console device. */
2084         if (dev_console_filename == NULL)
2085                 return (ENXIO);
2086
2087         /* Look up corresponding TTY by device name. */
2088         sx_slock(&tty_list_sx);
2089         TAILQ_FOREACH(tp, &tty_list, t_list) {
2090                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2091                         dev_console->si_drv1 = tp;
2092                         break;
2093                 }
2094         }
2095         sx_sunlock(&tty_list_sx);
2096
2097         /* System console has no TTY associated. */
2098         if (dev_console->si_drv1 == NULL)
2099                 return (ENXIO);
2100
2101         return (ttydev_open(dev, oflags, devtype, td));
2102 }
2103
2104 static int
2105 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2106 {
2107
2108         log_console(uio);
2109
2110         return (ttydev_write(dev, uio, ioflag));
2111 }
2112
2113 /*
2114  * /dev/console is a little different than normal TTY's.  When opened,
2115  * it determines which TTY to use.  When data gets written to it, it
2116  * will be logged in the kernel message buffer.
2117  */
2118 static struct cdevsw ttyconsdev_cdevsw = {
2119         .d_version      = D_VERSION,
2120         .d_open         = ttyconsdev_open,
2121         .d_close        = ttydev_close,
2122         .d_read         = ttydev_read,
2123         .d_write        = ttyconsdev_write,
2124         .d_ioctl        = ttydev_ioctl,
2125         .d_kqfilter     = ttydev_kqfilter,
2126         .d_poll         = ttydev_poll,
2127         .d_mmap         = ttydev_mmap,
2128         .d_name         = "ttyconsdev",
2129         .d_flags        = D_TTY,
2130 };
2131
2132 static void
2133 ttyconsdev_init(void *unused __unused)
2134 {
2135
2136         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2137             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2138 }
2139
2140 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2141
2142 void
2143 ttyconsdev_select(const char *name)
2144 {
2145
2146         dev_console_filename = name;
2147 }
2148
2149 /*
2150  * Debugging routines.
2151  */
2152
2153 #include "opt_ddb.h"
2154 #ifdef DDB
2155 #include <ddb/ddb.h>
2156 #include <ddb/db_sym.h>
2157
2158 static const struct {
2159         int flag;
2160         char val;
2161 } ttystates[] = {
2162 #if 0
2163         { TF_NOPREFIX,          'N' },
2164 #endif
2165         { TF_INITLOCK,          'I' },
2166         { TF_CALLOUT,           'C' },
2167
2168         /* Keep these together -> 'Oi' and 'Oo'. */
2169         { TF_OPENED,            'O' },
2170         { TF_OPENED_IN,         'i' },
2171         { TF_OPENED_OUT,        'o' },
2172         { TF_OPENED_CONS,       'c' },
2173
2174         { TF_GONE,              'G' },
2175         { TF_OPENCLOSE,         'B' },
2176         { TF_ASYNC,             'Y' },
2177         { TF_LITERAL,           'L' },
2178
2179         /* Keep these together -> 'Hi' and 'Ho'. */
2180         { TF_HIWAT,             'H' },
2181         { TF_HIWAT_IN,          'i' },
2182         { TF_HIWAT_OUT,         'o' },
2183
2184         { TF_STOPPED,           'S' },
2185         { TF_EXCLUDE,           'X' },
2186         { TF_BYPASS,            'l' },
2187         { TF_ZOMBIE,            'Z' },
2188         { TF_HOOK,              's' },
2189
2190         /* Keep these together -> 'bi' and 'bo'. */
2191         { TF_BUSY,              'b' },
2192         { TF_BUSY_IN,           'i' },
2193         { TF_BUSY_OUT,          'o' },
2194
2195         { 0,                    '\0'},
2196 };
2197
2198 #define TTY_FLAG_BITS \
2199         "\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2200         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2201         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2202         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2203         "\21HOOK\22BUSY_IN\23BUSY_OUT"
2204
2205 #define DB_PRINTSYM(name, addr) \
2206         db_printf("%s  " #name ": ", sep); \
2207         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2208         db_printf("\n");
2209
2210 static void
2211 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2212 {
2213
2214         db_printf("%sdevsw: ", sep);
2215         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2216         db_printf(" (%p)\n", tsw);
2217         DB_PRINTSYM(open, tsw->tsw_open);
2218         DB_PRINTSYM(close, tsw->tsw_close);
2219         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2220         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2221         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2222         DB_PRINTSYM(param, tsw->tsw_param);
2223         DB_PRINTSYM(modem, tsw->tsw_modem);
2224         DB_PRINTSYM(mmap, tsw->tsw_mmap);
2225         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2226         DB_PRINTSYM(free, tsw->tsw_free);
2227 }
2228
2229 static void
2230 _db_show_hooks(const char *sep, const struct ttyhook *th)
2231 {
2232
2233         db_printf("%shook: ", sep);
2234         db_printsym((db_addr_t)th, DB_STGY_ANY);
2235         db_printf(" (%p)\n", th);
2236         if (th == NULL)
2237                 return;
2238         DB_PRINTSYM(rint, th->th_rint);
2239         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2240         DB_PRINTSYM(rint_done, th->th_rint_done);
2241         DB_PRINTSYM(rint_poll, th->th_rint_poll);
2242         DB_PRINTSYM(getc_inject, th->th_getc_inject);
2243         DB_PRINTSYM(getc_capture, th->th_getc_capture);
2244         DB_PRINTSYM(getc_poll, th->th_getc_poll);
2245         DB_PRINTSYM(close, th->th_close);
2246 }
2247
2248 static void
2249 _db_show_termios(const char *name, const struct termios *t)
2250 {
2251
2252         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2253             "lflag 0x%x ispeed %u ospeed %u\n", name,
2254             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2255             t->c_ispeed, t->c_ospeed);
2256 }
2257
2258 /* DDB command to show TTY statistics. */
2259 DB_SHOW_COMMAND(tty, db_show_tty)
2260 {
2261         struct tty *tp;
2262
2263         if (!have_addr) {
2264                 db_printf("usage: show tty <addr>\n");
2265                 return;
2266         }
2267         tp = (struct tty *)addr;
2268
2269         db_printf("%p: %s\n", tp, tty_devname(tp));
2270         db_printf("\tmtx: %p\n", tp->t_mtx);
2271         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2272         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2273
2274         /* Buffering mechanisms. */
2275         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2276             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2277             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2278             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2279         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2280             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2281             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2282         db_printf("\tinlow: %zu\n", tp->t_inlow);
2283         db_printf("\toutlow: %zu\n", tp->t_outlow);
2284         _db_show_termios("\ttermios", &tp->t_termios);
2285         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2286             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2287             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2288         db_printf("\tcolumn: %u\n", tp->t_column);
2289         db_printf("\twritepos: %u\n", tp->t_writepos);
2290         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2291
2292         /* Init/lock-state devices. */
2293         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2294         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2295         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2296         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2297
2298         /* Hooks */
2299         _db_show_devsw("\t", tp->t_devsw);
2300         _db_show_hooks("\t", tp->t_hook);
2301
2302         /* Process info. */
2303         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2304             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2305             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2306         db_printf("\tsession: %p", tp->t_session);
2307         if (tp->t_session != NULL)
2308             db_printf(" count %u leader %p tty %p sid %d login %s",
2309                 tp->t_session->s_count, tp->t_session->s_leader,
2310                 tp->t_session->s_ttyp, tp->t_session->s_sid,
2311                 tp->t_session->s_login);
2312         db_printf("\n");
2313         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2314         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2315         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2316         db_printf("\tdev: %p\n", tp->t_dev);
2317 }
2318
2319 /* DDB command to list TTYs. */
2320 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2321 {
2322         struct tty *tp;
2323         size_t isiz, osiz;
2324         int i, j;
2325
2326         /* Make the output look like `pstat -t'. */
2327         db_printf("PTR        ");
2328 #if defined(__LP64__)
2329         db_printf("        ");
2330 #endif
2331         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2332             "COL  SESS  PGID STATE\n");
2333
2334         TAILQ_FOREACH(tp, &tty_list, t_list) {
2335                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2336                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2337
2338                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2339                     "%5d ", tp, tty_devname(tp), isiz,
2340                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2341                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2342                     isiz - tp->t_inlow, osiz,
2343                     tp->t_outq.to_end - tp->t_outq.to_begin,
2344                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2345                     tp->t_session ? tp->t_session->s_sid : 0,
2346                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2347
2348                 /* Flag bits. */
2349                 for (i = j = 0; ttystates[i].flag; i++)
2350                         if (tp->t_flags & ttystates[i].flag) {
2351                                 db_printf("%c", ttystates[i].val);
2352                                 j++;
2353                         }
2354                 if (j == 0)
2355                         db_printf("-");
2356                 db_printf("\n");
2357         }
2358 }
2359 #endif /* DDB */