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