sys/kern/tty.c

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