sys/kern/tty.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed under sponsorship from Snow
   8  * B.V., the Netherlands.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_capsicum.h"
  36 #include "opt_printf.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/capsicum.h>
  40 #include <sys/conf.h>
  41 #include <sys/cons.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/file.h>
  44 #include <sys/filedesc.h>
  45 #include <sys/filio.h>
  46 #ifdef COMPAT_43TTY
  47 #include <sys/ioctl_compat.h>
  48 #endif /* COMPAT_43TTY */
  49 #include <sys/kernel.h>
  50 #include <sys/limits.h>
  51 #include <sys/malloc.h>
  52 #include <sys/mount.h>
  53 #include <sys/poll.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/serial.h>
  57 #include <sys/signal.h>
  58 #include <sys/stat.h>
  59 #include <sys/sx.h>
  60 #include <sys/sysctl.h>
  61 #include <sys/systm.h>
  62 #include <sys/tty.h>
  63 #include <sys/ttycom.h>
  64 #define TTYDEFCHARS
  65 #include <sys/ttydefaults.h>
  66 #undef TTYDEFCHARS
  67 #include <sys/ucred.h>
  68 #include <sys/vnode.h>
  69
  70 #include <machine/stdarg.h>
  71
  72 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
  73
  74 static void tty_rel_free(struct tty *tp);
  75
  76 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
  77 static struct sx tty_list_sx;
  78 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
  79 static unsigned int tty_list_count = 0;
  80
  81 /* Character device of /dev/console. */
  82 static struct cdev      *dev_console;
  83 static const char       *dev_console_filename;
  84
  85 /*
  86  * Flags that are supported and stored by this implementation.
  87  */
  88 #define TTYSUP_IFLAG    (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
  89                         INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
  90 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
  91 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
  92                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
  93                         FLUSHO|NOKERNINFO|NOFLSH)
  94 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
  95                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
  96                         CDSR_OFLOW|CCAR_OFLOW)
  97
  98 #define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
  99
 100 static int  tty_drainwait = 5 * 60;
 101 SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
 102     &tty_drainwait, 0, "Default output drain timeout in seconds");
 103
 104 /*
 105  * Set TTY buffer sizes.
 106  */
 107
 108 #define TTYBUF_MAX      65536
 109
 110 #ifdef PRINTF_BUFR_SIZE
 111 #define TTY_PRBUF_SIZE  PRINTF_BUFR_SIZE
 112 #else
 113 #define TTY_PRBUF_SIZE  256
 114 #endif
 115
 116 /*
 117  * Allocate buffer space if necessary, and set low watermarks, based on speed.
 118  * Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
 119  * lock during memory allocation.  They will return ENXIO if the tty disappears
 120  * while unlocked.
 121  */
 122 static int
 123 tty_watermarks(struct tty *tp)
 124 {
 125         size_t bs = 0;
 126         int error;
 127
 128         /* Provide an input buffer for 2 seconds of data. */
 129         if (tp->t_termios.c_cflag & CREAD)
 130                 bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
 131         error = ttyinq_setsize(&tp->t_inq, tp, bs);
 132         if (error != 0)
 133                 return (error);
 134
 135         /* Set low watermark at 10% (when 90% is available). */
 136         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
 137
 138         /* Provide an output buffer for 2 seconds of data. */
 139         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
 140         error = ttyoutq_setsize(&tp->t_outq, tp, bs);
 141         if (error != 0)
 142                 return (error);
 143
 144         /* Set low watermark at 10% (when 90% is available). */
 145         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
 146
 147         return (0);
 148 }
 149
 150 static int
 151 tty_drain(struct tty *tp, int leaving)
 152 {
 153         sbintime_t timeout_at;
 154         size_t bytes;
 155         int error;
 156
 157         if (ttyhook_hashook(tp, getc_inject))
 158                 /* buffer is inaccessible */
 159                 return (0);
 160
 161         /*
 162          * For close(), use the recent historic timeout of "1 second without
 163          * making progress".  For tcdrain(), use t_drainwait as the timeout,
 164          * with zero meaning "no timeout" which gives POSIX behavior.
 165          */
 166         if (leaving)
 167                 timeout_at = getsbinuptime() + SBT_1S;
 168         else if (tp->t_drainwait != 0)
 169                 timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
 170         else
 171                 timeout_at = 0;
 172
 173         /*
 174          * Poll the output buffer and the hardware for completion, at 10 Hz.
 175          * Polling is required for devices which are not able to signal an
 176          * interrupt when the transmitter becomes idle (most USB serial devs).
 177          * The unusual structure of this loop ensures we check for busy one more
 178          * time after tty_timedwait() returns EWOULDBLOCK, so that success has
 179          * higher priority than timeout if the IO completed in the last 100mS.
 180          */
 181         error = 0;
 182         bytes = ttyoutq_bytesused(&tp->t_outq);
 183         for (;;) {
 184                 if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
 185                         return (0);
 186                 if (error != 0)
 187                         return (error);
 188                 ttydevsw_outwakeup(tp);
 189                 error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
 190                 if (error != 0 && error != EWOULDBLOCK)
 191                         return (error);
 192                 else if (timeout_at == 0 || getsbinuptime() < timeout_at)
 193                         error = 0;
 194                 else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
 195                         /* In close, making progress, grant an extra second. */
 196                         error = 0;
 197                         timeout_at += SBT_1S;
 198                         bytes = ttyoutq_bytesused(&tp->t_outq);
 199                 }
 200         }
 201 }
 202
 203 /*
 204  * Though ttydev_enter() and ttydev_leave() seem to be related, they
 205  * don't have to be used together. ttydev_enter() is used by the cdev
 206  * operations to prevent an actual operation from being processed when
 207  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
 208  * and ttydev_close() to determine whether per-TTY data should be
 209  * deallocated.
 210  */
 211
 212 static __inline int
 213 ttydev_enter(struct tty *tp)
 214 {
 215
 216         tty_lock(tp);
 217
 218         if (tty_gone(tp) || !tty_opened(tp)) {
 219                 /* Device is already gone. */
 220                 tty_unlock(tp);
 221                 return (ENXIO);
 222         }
 223
 224         return (0);
 225 }
 226
 227 static void
 228 ttydev_leave(struct tty *tp)
 229 {
 230
 231         tty_lock_assert(tp, MA_OWNED);
 232
 233         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
 234                 /* Device is still opened somewhere. */
 235                 tty_unlock(tp);
 236                 return;
 237         }
 238
 239         tp->t_flags |= TF_OPENCLOSE;
 240
 241         /* Stop asynchronous I/O. */
 242         funsetown(&tp->t_sigio);
 243
 244         /* Remove console TTY. */
 245         if (constty == tp)
 246                 constty_clear();
 247
 248         /* Drain any output. */
 249         if (!tty_gone(tp))
 250                 tty_drain(tp, 1);
 251
 252         ttydisc_close(tp);
 253
 254         /* Free i/o queues now since they might be large. */
 255         ttyinq_free(&tp->t_inq);
 256         tp->t_inlow = 0;
 257         ttyoutq_free(&tp->t_outq);
 258         tp->t_outlow = 0;
 259
 260         knlist_clear(&tp->t_inpoll.si_note, 1);
 261         knlist_clear(&tp->t_outpoll.si_note, 1);
 262
 263         if (!tty_gone(tp))
 264                 ttydevsw_close(tp);
 265
 266         tp->t_flags &= ~TF_OPENCLOSE;
 267         cv_broadcast(&tp->t_dcdwait);
 268         tty_rel_free(tp);
 269 }
 270
 271 /*
 272  * Operations that are exposed through the character device in /dev.
 273  */
 274 static int
 275 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
 276     struct thread *td)
 277 {
 278         struct tty *tp;
 279         int error;
 280
 281         tp = dev->si_drv1;
 282         error = 0;
 283         tty_lock(tp);
 284         if (tty_gone(tp)) {
 285                 /* Device is already gone. */
 286                 tty_unlock(tp);
 287                 return (ENXIO);
 288         }
 289
 290         /*
 291          * Block when other processes are currently opening or closing
 292          * the TTY.
 293          */
 294         while (tp->t_flags & TF_OPENCLOSE) {
 295                 error = tty_wait(tp, &tp->t_dcdwait);
 296                 if (error != 0) {
 297                         tty_unlock(tp);
 298                         return (error);
 299                 }
 300         }
 301         tp->t_flags |= TF_OPENCLOSE;
 302
 303         /*
 304          * Make sure the "tty" and "cua" device cannot be opened at the
 305          * same time.  The console is a "tty" device.
 306          */
 307         if (TTY_CALLOUT(tp, dev)) {
 308                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
 309                         error = EBUSY;
 310                         goto done;
 311                 }
 312         } else {
 313                 if (tp->t_flags & TF_OPENED_OUT) {
 314                         error = EBUSY;
 315                         goto done;
 316                 }
 317         }
 318
 319         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
 320                 error = EBUSY;
 321                 goto done;
 322         }
 323
 324         if (!tty_opened(tp)) {
 325                 /* Set proper termios flags. */
 326                 if (TTY_CALLOUT(tp, dev))
 327                         tp->t_termios = tp->t_termios_init_out;
 328                 else
 329                         tp->t_termios = tp->t_termios_init_in;
 330                 ttydevsw_param(tp, &tp->t_termios);
 331                 /* Prevent modem control on callout devices and /dev/console. */
 332                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
 333                         tp->t_termios.c_cflag |= CLOCAL;
 334
 335                 ttydevsw_modem(tp, SER_DTR|SER_RTS, 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) + TTY_PRBUF_SIZE, M_TTY,
1062             M_WAITOK | M_ZERO);
1063         tp->t_prbufsz = TTY_PRBUF_SIZE;
1064         tp->t_devsw = tsw;
1065         tp->t_devswsoftc = sc;
1066         tp->t_flags = tsw->tsw_flags;
1067         tp->t_drainwait = tty_drainwait;
1068
1069         tty_init_termios(tp);
1070
1071         cv_init(&tp->t_inwait, "ttyin");
1072         cv_init(&tp->t_outwait, "ttyout");
1073         cv_init(&tp->t_outserwait, "ttyosr");
1074         cv_init(&tp->t_bgwait, "ttybg");
1075         cv_init(&tp->t_dcdwait, "ttydcd");
1076
1077         /* Allow drivers to use a custom mutex to lock the TTY. */
1078         if (mutex != NULL) {
1079                 tp->t_mtx = mutex;
1080         } else {
1081                 tp->t_mtx = &tp->t_mtxobj;
1082                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1083         }
1084
1085         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1086         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1087
1088         return (tp);
1089 }
1090
1091 static void
1092 tty_dealloc(void *arg)
1093 {
1094         struct tty *tp = arg;
1095
1096         /*
1097          * ttyydev_leave() usually frees the i/o queues earlier, but it is
1098          * not always called between queue allocation and here.  The queues
1099          * may be allocated by ioctls on a pty control device without the
1100          * corresponding pty slave device ever being open, or after it is
1101          * closed.
1102          */
1103         ttyinq_free(&tp->t_inq);
1104         ttyoutq_free(&tp->t_outq);
1105         seldrain(&tp->t_inpoll);
1106         seldrain(&tp->t_outpoll);
1107         knlist_destroy(&tp->t_inpoll.si_note);
1108         knlist_destroy(&tp->t_outpoll.si_note);
1109
1110         cv_destroy(&tp->t_inwait);
1111         cv_destroy(&tp->t_outwait);
1112         cv_destroy(&tp->t_bgwait);
1113         cv_destroy(&tp->t_dcdwait);
1114         cv_destroy(&tp->t_outserwait);
1115
1116         if (tp->t_mtx == &tp->t_mtxobj)
1117                 mtx_destroy(&tp->t_mtxobj);
1118         ttydevsw_free(tp);
1119         free(tp, M_TTY);
1120 }
1121
1122 static void
1123 tty_rel_free(struct tty *tp)
1124 {
1125         struct cdev *dev;
1126
1127         tty_lock_assert(tp, MA_OWNED);
1128
1129 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1130         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1131                 /* TTY is still in use. */
1132                 tty_unlock(tp);
1133                 return;
1134         }
1135
1136         /* TTY can be deallocated. */
1137         dev = tp->t_dev;
1138         tp->t_dev = NULL;
1139         tty_unlock(tp);
1140
1141         if (dev != NULL) {
1142                 sx_xlock(&tty_list_sx);
1143                 TAILQ_REMOVE(&tty_list, tp, t_list);
1144                 tty_list_count--;
1145                 sx_xunlock(&tty_list_sx);
1146                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
1147         }
1148 }
1149
1150 void
1151 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1152 {
1153
1154         MPASS(tp->t_sessioncnt > 0);
1155         tty_lock_assert(tp, MA_OWNED);
1156
1157         if (tp->t_pgrp == pg)
1158                 tp->t_pgrp = NULL;
1159
1160         tty_unlock(tp);
1161 }
1162
1163 void
1164 tty_rel_sess(struct tty *tp, struct session *sess)
1165 {
1166
1167         MPASS(tp->t_sessioncnt > 0);
1168
1169         /* Current session has left. */
1170         if (tp->t_session == sess) {
1171                 tp->t_session = NULL;
1172                 MPASS(tp->t_pgrp == NULL);
1173         }
1174         tp->t_sessioncnt--;
1175         tty_rel_free(tp);
1176 }
1177
1178 void
1179 tty_rel_gone(struct tty *tp)
1180 {
1181
1182         MPASS(!tty_gone(tp));
1183
1184         /* Simulate carrier removal. */
1185         ttydisc_modem(tp, 0);
1186
1187         /* Wake up all blocked threads. */
1188         tty_wakeup(tp, FREAD|FWRITE);
1189         cv_broadcast(&tp->t_bgwait);
1190         cv_broadcast(&tp->t_dcdwait);
1191
1192         tp->t_flags |= TF_GONE;
1193         tty_rel_free(tp);
1194 }
1195
1196 /*
1197  * Exposing information about current TTY's through sysctl
1198  */
1199
1200 static void
1201 tty_to_xtty(struct tty *tp, struct xtty *xt)
1202 {
1203
1204         tty_lock_assert(tp, MA_OWNED);
1205
1206         xt->xt_size = sizeof(struct xtty);
1207         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1208         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1209         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1210         xt->xt_inlow = tp->t_inlow;
1211         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1212         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1213         xt->xt_outlow = tp->t_outlow;
1214         xt->xt_column = tp->t_column;
1215         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1216         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1217         xt->xt_flags = tp->t_flags;
1218         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : (uint32_t)NODEV;
1219 }
1220
1221 static int
1222 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1223 {
1224         unsigned long lsize;
1225         struct xtty *xtlist, *xt;
1226         struct tty *tp;
1227         int error;
1228
1229         sx_slock(&tty_list_sx);
1230         lsize = tty_list_count * sizeof(struct xtty);
1231         if (lsize == 0) {
1232                 sx_sunlock(&tty_list_sx);
1233                 return (0);
1234         }
1235
1236         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1237
1238         TAILQ_FOREACH(tp, &tty_list, t_list) {
1239                 tty_lock(tp);
1240                 tty_to_xtty(tp, xt);
1241                 tty_unlock(tp);
1242                 xt++;
1243         }
1244         sx_sunlock(&tty_list_sx);
1245
1246         error = SYSCTL_OUT(req, xtlist, lsize);
1247         free(xtlist, M_TTY);
1248         return (error);
1249 }
1250
1251 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1252         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1253
1254 /*
1255  * Device node creation. Device has been set up, now we can expose it to
1256  * the user.
1257  */
1258
1259 int
1260 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1261     const char *fmt, ...)
1262 {
1263         va_list ap;
1264         struct make_dev_args args;
1265         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1266         const char *prefix = "tty";
1267         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1268         uid_t uid;
1269         gid_t gid;
1270         mode_t mode;
1271         int error;
1272
1273         /* Remove "tty" prefix from devices like PTY's. */
1274         if (tp->t_flags & TF_NOPREFIX)
1275                 prefix = "";
1276
1277         va_start(ap, fmt);
1278         vsnrprintf(name, sizeof name, 32, fmt, ap);
1279         va_end(ap);
1280
1281         if (cred == NULL) {
1282                 /* System device. */
1283                 uid = UID_ROOT;
1284                 gid = GID_WHEEL;
1285                 mode = S_IRUSR|S_IWUSR;
1286         } else {
1287                 /* User device. */
1288                 uid = cred->cr_ruid;
1289                 gid = GID_TTY;
1290                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
1291         }
1292
1293         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1294         flags |= MAKEDEV_CHECKNAME;
1295
1296         /* Master call-in device. */
1297         make_dev_args_init(&args);
1298         args.mda_flags = flags;
1299         args.mda_devsw = &ttydev_cdevsw;
1300         args.mda_cr = cred;
1301         args.mda_uid = uid;
1302         args.mda_gid = gid;
1303         args.mda_mode = mode;
1304         args.mda_si_drv1 = tp;
1305         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1306         if (error != 0)
1307                 return (error);
1308         tp->t_dev = dev;
1309
1310         init = lock = cua = cinit = clock = NULL;
1311
1312         /* Slave call-in devices. */
1313         if (tp->t_flags & TF_INITLOCK) {
1314                 args.mda_devsw = &ttyil_cdevsw;
1315                 args.mda_unit = TTYUNIT_INIT;
1316                 args.mda_si_drv1 = tp;
1317                 args.mda_si_drv2 = &tp->t_termios_init_in;
1318                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1319                 if (error != 0)
1320                         goto fail;
1321                 dev_depends(dev, init);
1322
1323                 args.mda_unit = TTYUNIT_LOCK;
1324                 args.mda_si_drv2 = &tp->t_termios_lock_in;
1325                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1326                 if (error != 0)
1327                         goto fail;
1328                 dev_depends(dev, lock);
1329         }
1330
1331         /* Call-out devices. */
1332         if (tp->t_flags & TF_CALLOUT) {
1333                 make_dev_args_init(&args);
1334                 args.mda_flags = flags;
1335                 args.mda_devsw = &ttydev_cdevsw;
1336                 args.mda_cr = cred;
1337                 args.mda_uid = UID_UUCP;
1338                 args.mda_gid = GID_DIALER;
1339                 args.mda_mode = 0660;
1340                 args.mda_unit = TTYUNIT_CALLOUT;
1341                 args.mda_si_drv1 = tp;
1342                 error = make_dev_s(&args, &cua, "cua%s", name);
1343                 if (error != 0)
1344                         goto fail;
1345                 dev_depends(dev, cua);
1346
1347                 /* Slave call-out devices. */
1348                 if (tp->t_flags & TF_INITLOCK) {
1349                         args.mda_devsw = &ttyil_cdevsw;
1350                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1351                         args.mda_si_drv2 = &tp->t_termios_init_out;
1352                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
1353                         if (error != 0)
1354                                 goto fail;
1355                         dev_depends(dev, cinit);
1356
1357                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1358                         args.mda_si_drv2 = &tp->t_termios_lock_out;
1359                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
1360                         if (error != 0)
1361                                 goto fail;
1362                         dev_depends(dev, clock);
1363                 }
1364         }
1365
1366         sx_xlock(&tty_list_sx);
1367         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1368         tty_list_count++;
1369         sx_xunlock(&tty_list_sx);
1370
1371         return (0);
1372
1373 fail:
1374         destroy_dev(dev);
1375         if (init)
1376                 destroy_dev(init);
1377         if (lock)
1378                 destroy_dev(lock);
1379         if (cinit)
1380                 destroy_dev(cinit);
1381         if (clock)
1382                 destroy_dev(clock);
1383
1384         return (error);
1385 }
1386
1387 /*
1388  * Signalling processes.
1389  */
1390
1391 void
1392 tty_signal_sessleader(struct tty *tp, int sig)
1393 {
1394         struct proc *p;
1395
1396         tty_lock_assert(tp, MA_OWNED);
1397         MPASS(sig >= 1 && sig < NSIG);
1398
1399         /* Make signals start output again. */
1400         tp->t_flags &= ~TF_STOPPED;
1401
1402         if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1403                 p = tp->t_session->s_leader;
1404                 PROC_LOCK(p);
1405                 kern_psignal(p, sig);
1406                 PROC_UNLOCK(p);
1407         }
1408 }
1409
1410 void
1411 tty_signal_pgrp(struct tty *tp, int sig)
1412 {
1413         ksiginfo_t ksi;
1414
1415         tty_lock_assert(tp, MA_OWNED);
1416         MPASS(sig >= 1 && sig < NSIG);
1417
1418         /* Make signals start output again. */
1419         tp->t_flags &= ~TF_STOPPED;
1420
1421         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1422                 tty_info(tp);
1423         if (tp->t_pgrp != NULL) {
1424                 ksiginfo_init(&ksi);
1425                 ksi.ksi_signo = sig;
1426                 ksi.ksi_code = SI_KERNEL;
1427                 PGRP_LOCK(tp->t_pgrp);
1428                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
1429                 PGRP_UNLOCK(tp->t_pgrp);
1430         }
1431 }
1432
1433 void
1434 tty_wakeup(struct tty *tp, int flags)
1435 {
1436
1437         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1438                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1439
1440         if (flags & FWRITE) {
1441                 cv_broadcast(&tp->t_outwait);
1442                 selwakeup(&tp->t_outpoll);
1443                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1444         }
1445         if (flags & FREAD) {
1446                 cv_broadcast(&tp->t_inwait);
1447                 selwakeup(&tp->t_inpoll);
1448                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1449         }
1450 }
1451
1452 int
1453 tty_wait(struct tty *tp, struct cv *cv)
1454 {
1455         int error;
1456         int revokecnt = tp->t_revokecnt;
1457
1458         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1459         MPASS(!tty_gone(tp));
1460
1461         error = cv_wait_sig(cv, tp->t_mtx);
1462
1463         /* Bail out when the device slipped away. */
1464         if (tty_gone(tp))
1465                 return (ENXIO);
1466
1467         /* Restart the system call when we may have been revoked. */
1468         if (tp->t_revokecnt != revokecnt)
1469                 return (ERESTART);
1470
1471         return (error);
1472 }
1473
1474 int
1475 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1476 {
1477         int error;
1478         int revokecnt = tp->t_revokecnt;
1479
1480         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1481         MPASS(!tty_gone(tp));
1482
1483         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1484
1485         /* Bail out when the device slipped away. */
1486         if (tty_gone(tp))
1487                 return (ENXIO);
1488
1489         /* Restart the system call when we may have been revoked. */
1490         if (tp->t_revokecnt != revokecnt)
1491                 return (ERESTART);
1492
1493         return (error);
1494 }
1495
1496 void
1497 tty_flush(struct tty *tp, int flags)
1498 {
1499
1500         if (flags & FWRITE) {
1501                 tp->t_flags &= ~TF_HIWAT_OUT;
1502                 ttyoutq_flush(&tp->t_outq);
1503                 tty_wakeup(tp, FWRITE);
1504                 if (!tty_gone(tp)) {
1505                         ttydevsw_outwakeup(tp);
1506                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1507                 }
1508         }
1509         if (flags & FREAD) {
1510                 tty_hiwat_in_unblock(tp);
1511                 ttyinq_flush(&tp->t_inq);
1512                 tty_wakeup(tp, FREAD);
1513                 if (!tty_gone(tp)) {
1514                         ttydevsw_inwakeup(tp);
1515                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1516                 }
1517         }
1518 }
1519
1520 void
1521 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1522 {
1523
1524         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1525                 return;
1526         tp->t_winsize = *wsz;
1527         tty_signal_pgrp(tp, SIGWINCH);
1528 }
1529
1530 static int
1531 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1532     struct thread *td)
1533 {
1534         int error;
1535
1536         switch (cmd) {
1537         /*
1538          * Modem commands.
1539          * The SER_* and TIOCM_* flags are the same, but one bit
1540          * shifted. I don't know why.
1541          */
1542         case TIOCSDTR:
1543                 ttydevsw_modem(tp, SER_DTR, 0);
1544                 return (0);
1545         case TIOCCDTR:
1546                 ttydevsw_modem(tp, 0, SER_DTR);
1547                 return (0);
1548         case TIOCMSET: {
1549                 int bits = *(int *)data;
1550                 ttydevsw_modem(tp,
1551                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1552                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1553                 return (0);
1554         }
1555         case TIOCMBIS: {
1556                 int bits = *(int *)data;
1557                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1558                 return (0);
1559         }
1560         case TIOCMBIC: {
1561                 int bits = *(int *)data;
1562                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1563                 return (0);
1564         }
1565         case TIOCMGET:
1566                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1567                 return (0);
1568
1569         case FIOASYNC:
1570                 if (*(int *)data)
1571                         tp->t_flags |= TF_ASYNC;
1572                 else
1573                         tp->t_flags &= ~TF_ASYNC;
1574                 return (0);
1575         case FIONBIO:
1576                 /* This device supports non-blocking operation. */
1577                 return (0);
1578         case FIONREAD:
1579                 *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1580                 return (0);
1581         case FIONWRITE:
1582         case TIOCOUTQ:
1583                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
1584                 return (0);
1585         case FIOSETOWN:
1586                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1587                         /* Not allowed to set ownership. */
1588                         return (ENOTTY);
1589
1590                 /* Temporarily unlock the TTY to set ownership. */
1591                 tty_unlock(tp);
1592                 error = fsetown(*(int *)data, &tp->t_sigio);
1593                 tty_lock(tp);
1594                 return (error);
1595         case FIOGETOWN:
1596                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1597                         /* Not allowed to set ownership. */
1598                         return (ENOTTY);
1599
1600                 /* Get ownership. */
1601                 *(int *)data = fgetown(&tp->t_sigio);
1602                 return (0);
1603         case TIOCGETA:
1604                 /* Obtain terminal flags through tcgetattr(). */
1605                 *(struct termios*)data = tp->t_termios;
1606                 return (0);
1607         case TIOCSETA:
1608         case TIOCSETAW:
1609         case TIOCSETAF: {
1610                 struct termios *t = data;
1611
1612                 /*
1613                  * Who makes up these funny rules? According to POSIX,
1614                  * input baud rate is set equal to the output baud rate
1615                  * when zero.
1616                  */
1617                 if (t->c_ispeed == 0)
1618                         t->c_ispeed = t->c_ospeed;
1619
1620                 /* Discard any unsupported bits. */
1621                 t->c_iflag &= TTYSUP_IFLAG;
1622                 t->c_oflag &= TTYSUP_OFLAG;
1623                 t->c_lflag &= TTYSUP_LFLAG;
1624                 t->c_cflag &= TTYSUP_CFLAG;
1625
1626                 /* Set terminal flags through tcsetattr(). */
1627                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1628                         error = tty_drain(tp, 0);
1629                         if (error)
1630                                 return (error);
1631                         if (cmd == TIOCSETAF)
1632                                 tty_flush(tp, FREAD);
1633                 }
1634
1635                 /*
1636                  * Only call param() when the flags really change.
1637                  */
1638                 if ((t->c_cflag & CIGNORE) == 0 &&
1639                     (tp->t_termios.c_cflag != t->c_cflag ||
1640                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
1641                     (IXON|IXOFF|IXANY)) ||
1642                     tp->t_termios.c_ispeed != t->c_ispeed ||
1643                     tp->t_termios.c_ospeed != t->c_ospeed)) {
1644                         error = ttydevsw_param(tp, t);
1645                         if (error)
1646                                 return (error);
1647
1648                         /* XXX: CLOCAL? */
1649
1650                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1651                         tp->t_termios.c_ispeed = t->c_ispeed;
1652                         tp->t_termios.c_ospeed = t->c_ospeed;
1653
1654                         /* Baud rate has changed - update watermarks. */
1655                         error = tty_watermarks(tp);
1656                         if (error)
1657                                 return (error);
1658                 }
1659
1660                 /* Copy new non-device driver parameters. */
1661                 tp->t_termios.c_iflag = t->c_iflag;
1662                 tp->t_termios.c_oflag = t->c_oflag;
1663                 tp->t_termios.c_lflag = t->c_lflag;
1664                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1665
1666                 ttydisc_optimize(tp);
1667
1668                 if ((t->c_lflag & ICANON) == 0) {
1669                         /*
1670                          * When in non-canonical mode, wake up all
1671                          * readers. Canonicalize any partial input. VMIN
1672                          * and VTIME could also be adjusted.
1673                          */
1674                         ttyinq_canonicalize(&tp->t_inq);
1675                         tty_wakeup(tp, FREAD);
1676                 }
1677
1678                 /*
1679                  * For packet mode: notify the PTY consumer that VSTOP
1680                  * and VSTART may have been changed.
1681                  */
1682                 if (tp->t_termios.c_iflag & IXON &&
1683                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1684                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1685                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1686                 else
1687                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1688                 return (0);
1689         }
1690         case TIOCGETD:
1691                 /* For compatibility - we only support TTYDISC. */
1692                 *(int *)data = TTYDISC;
1693                 return (0);
1694         case TIOCGPGRP:
1695                 if (!tty_is_ctty(tp, td->td_proc))
1696                         return (ENOTTY);
1697
1698                 if (tp->t_pgrp != NULL)
1699                         *(int *)data = tp->t_pgrp->pg_id;
1700                 else
1701                         *(int *)data = NO_PID;
1702                 return (0);
1703         case TIOCGSID:
1704                 if (!tty_is_ctty(tp, td->td_proc))
1705                         return (ENOTTY);
1706
1707                 MPASS(tp->t_session);
1708                 *(int *)data = tp->t_session->s_sid;
1709                 return (0);
1710         case TIOCSCTTY: {
1711                 struct proc *p = td->td_proc;
1712
1713                 /* XXX: This looks awful. */
1714                 tty_unlock(tp);
1715                 sx_xlock(&proctree_lock);
1716                 tty_lock(tp);
1717
1718                 if (!SESS_LEADER(p)) {
1719                         /* Only the session leader may do this. */
1720                         sx_xunlock(&proctree_lock);
1721                         return (EPERM);
1722                 }
1723
1724                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
1725                         /* This is already our controlling TTY. */
1726                         sx_xunlock(&proctree_lock);
1727                         return (0);
1728                 }
1729
1730                 if (p->p_session->s_ttyp != NULL ||
1731                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1732                     tp->t_session->s_ttyvp->v_type != VBAD)) {
1733                         /*
1734                          * There is already a relation between a TTY and
1735                          * a session, or the caller is not the session
1736                          * leader.
1737                          *
1738                          * Allow the TTY to be stolen when the vnode is
1739                          * invalid, but the reference to the TTY is
1740                          * still active.  This allows immediate reuse of
1741                          * TTYs of which the session leader has been
1742                          * killed or the TTY revoked.
1743                          */
1744                         sx_xunlock(&proctree_lock);
1745                         return (EPERM);
1746                 }
1747
1748                 /* Connect the session to the TTY. */
1749                 tp->t_session = p->p_session;
1750                 tp->t_session->s_ttyp = tp;
1751                 tp->t_sessioncnt++;
1752                 sx_xunlock(&proctree_lock);
1753
1754                 /* Assign foreground process group. */
1755                 tp->t_pgrp = p->p_pgrp;
1756                 PROC_LOCK(p);
1757                 p->p_flag |= P_CONTROLT;
1758                 PROC_UNLOCK(p);
1759
1760                 return (0);
1761         }
1762         case TIOCSPGRP: {
1763                 struct pgrp *pg;
1764
1765                 /*
1766                  * XXX: Temporarily unlock the TTY to locate the process
1767                  * group. This code would be lot nicer if we would ever
1768                  * decompose proctree_lock.
1769                  */
1770                 tty_unlock(tp);
1771                 sx_slock(&proctree_lock);
1772                 pg = pgfind(*(int *)data);
1773                 if (pg != NULL)
1774                         PGRP_UNLOCK(pg);
1775                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1776                         sx_sunlock(&proctree_lock);
1777                         tty_lock(tp);
1778                         return (EPERM);
1779                 }
1780                 tty_lock(tp);
1781
1782                 /*
1783                  * Determine if this TTY is the controlling TTY after
1784                  * relocking the TTY.
1785                  */
1786                 if (!tty_is_ctty(tp, td->td_proc)) {
1787                         sx_sunlock(&proctree_lock);
1788                         return (ENOTTY);
1789                 }
1790                 tp->t_pgrp = pg;
1791                 sx_sunlock(&proctree_lock);
1792
1793                 /* Wake up the background process groups. */
1794                 cv_broadcast(&tp->t_bgwait);
1795                 return (0);
1796         }
1797         case TIOCFLUSH: {
1798                 int flags = *(int *)data;
1799
1800                 if (flags == 0)
1801                         flags = (FREAD|FWRITE);
1802                 else
1803                         flags &= (FREAD|FWRITE);
1804                 tty_flush(tp, flags);
1805                 return (0);
1806         }
1807         case TIOCDRAIN:
1808                 /* Drain TTY output. */
1809                 return tty_drain(tp, 0);
1810         case TIOCGDRAINWAIT:
1811                 *(int *)data = tp->t_drainwait;
1812                 return (0);
1813         case TIOCSDRAINWAIT:
1814                 error = priv_check(td, PRIV_TTY_DRAINWAIT);
1815                 if (error == 0)
1816                         tp->t_drainwait = *(int *)data;
1817                 return (error);
1818         case TIOCCONS:
1819                 /* Set terminal as console TTY. */
1820                 if (*(int *)data) {
1821                         error = priv_check(td, PRIV_TTY_CONSOLE);
1822                         if (error)
1823                                 return (error);
1824
1825                         /*
1826                          * XXX: constty should really need to be locked!
1827                          * XXX: allow disconnected constty's to be stolen!
1828                          */
1829
1830                         if (constty == tp)
1831                                 return (0);
1832                         if (constty != NULL)
1833                                 return (EBUSY);
1834
1835                         tty_unlock(tp);
1836                         constty_set(tp);
1837                         tty_lock(tp);
1838                 } else if (constty == tp) {
1839                         constty_clear();
1840                 }
1841                 return (0);
1842         case TIOCGWINSZ:
1843                 /* Obtain window size. */
1844                 *(struct winsize*)data = tp->t_winsize;
1845                 return (0);
1846         case TIOCSWINSZ:
1847                 /* Set window size. */
1848                 tty_set_winsize(tp, data);
1849                 return (0);
1850         case TIOCEXCL:
1851                 tp->t_flags |= TF_EXCLUDE;
1852                 return (0);
1853         case TIOCNXCL:
1854                 tp->t_flags &= ~TF_EXCLUDE;
1855                 return (0);
1856         case TIOCSTOP:
1857                 tp->t_flags |= TF_STOPPED;
1858                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1859                 return (0);
1860         case TIOCSTART:
1861                 tp->t_flags &= ~TF_STOPPED;
1862                 ttydevsw_outwakeup(tp);
1863                 ttydevsw_pktnotify(tp, TIOCPKT_START);
1864                 return (0);
1865         case TIOCSTAT:
1866                 tty_info(tp);
1867                 return (0);
1868         case TIOCSTI:
1869                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1870                         return (EPERM);
1871                 if (!tty_is_ctty(tp, td->td_proc) &&
1872                     priv_check(td, PRIV_TTY_STI))
1873                         return (EACCES);
1874                 ttydisc_rint(tp, *(char *)data, 0);
1875                 ttydisc_rint_done(tp);
1876                 return (0);
1877         }
1878
1879 #ifdef COMPAT_43TTY
1880         return tty_ioctl_compat(tp, cmd, data, fflag, td);
1881 #else /* !COMPAT_43TTY */
1882         return (ENOIOCTL);
1883 #endif /* COMPAT_43TTY */
1884 }
1885
1886 int
1887 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1888 {
1889         int error;
1890
1891         tty_lock_assert(tp, MA_OWNED);
1892
1893         if (tty_gone(tp))
1894                 return (ENXIO);
1895
1896         error = ttydevsw_ioctl(tp, cmd, data, td);
1897         if (error == ENOIOCTL)
1898                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1899
1900         return (error);
1901 }
1902
1903 dev_t
1904 tty_udev(struct tty *tp)
1905 {
1906
1907         if (tp->t_dev)
1908                 return (dev2udev(tp->t_dev));
1909         else
1910                 return (NODEV);
1911 }
1912
1913 int
1914 tty_checkoutq(struct tty *tp)
1915 {
1916
1917         /* 256 bytes should be enough to print a log message. */
1918         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1919 }
1920
1921 void
1922 tty_hiwat_in_block(struct tty *tp)
1923 {
1924
1925         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1926             tp->t_termios.c_iflag & IXOFF &&
1927             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1928                 /*
1929                  * Input flow control. Only enter the high watermark when we
1930                  * can successfully store the VSTOP character.
1931                  */
1932                 if (ttyoutq_write_nofrag(&tp->t_outq,
1933                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
1934                         tp->t_flags |= TF_HIWAT_IN;
1935         } else {
1936                 /* No input flow control. */
1937                 tp->t_flags |= TF_HIWAT_IN;
1938         }
1939 }
1940
1941 void
1942 tty_hiwat_in_unblock(struct tty *tp)
1943 {
1944
1945         if (tp->t_flags & TF_HIWAT_IN &&
1946             tp->t_termios.c_iflag & IXOFF &&
1947             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1948                 /*
1949                  * Input flow control. Only leave the high watermark when we
1950                  * can successfully store the VSTART character.
1951                  */
1952                 if (ttyoutq_write_nofrag(&tp->t_outq,
1953                     &tp->t_termios.c_cc[VSTART], 1) == 0)
1954                         tp->t_flags &= ~TF_HIWAT_IN;
1955         } else {
1956                 /* No input flow control. */
1957                 tp->t_flags &= ~TF_HIWAT_IN;
1958         }
1959
1960         if (!tty_gone(tp))
1961                 ttydevsw_inwakeup(tp);
1962 }
1963
1964 /*
1965  * TTY hooks interface.
1966  */
1967
1968 static int
1969 ttyhook_defrint(struct tty *tp, char c, int flags)
1970 {
1971
1972         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1973                 return (-1);
1974
1975         return (0);
1976 }
1977
1978 int
1979 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
1980     void *softc)
1981 {
1982         struct tty *tp;
1983         struct file *fp;
1984         struct cdev *dev;
1985         struct cdevsw *cdp;
1986         struct filedesc *fdp;
1987         cap_rights_t rights;
1988         int error, ref;
1989
1990         /* Validate the file descriptor. */
1991         fdp = p->p_fd;
1992         error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1993             &fp, NULL);
1994         if (error != 0)
1995                 return (error);
1996         if (fp->f_ops == &badfileops) {
1997                 error = EBADF;
1998                 goto done1;
1999         }
2000
2001         /*
2002          * Make sure the vnode is bound to a character device.
2003          * Unlocked check for the vnode type is ok there, because we
2004          * only shall prevent calling devvn_refthread on the file that
2005          * never has been opened over a character device.
2006          */
2007         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
2008                 error = EINVAL;
2009                 goto done1;
2010         }
2011
2012         /* Make sure it is a TTY. */
2013         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
2014         if (cdp == NULL) {
2015                 error = ENXIO;
2016                 goto done1;
2017         }
2018         if (dev != fp->f_data) {
2019                 error = ENXIO;
2020                 goto done2;
2021         }
2022         if (cdp != &ttydev_cdevsw) {
2023                 error = ENOTTY;
2024                 goto done2;
2025         }
2026         tp = dev->si_drv1;
2027
2028         /* Try to attach the hook to the TTY. */
2029         error = EBUSY;
2030         tty_lock(tp);
2031         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
2032         if (tp->t_flags & TF_HOOK)
2033                 goto done3;
2034
2035         tp->t_flags |= TF_HOOK;
2036         tp->t_hook = th;
2037         tp->t_hooksoftc = softc;
2038         *rtp = tp;
2039         error = 0;
2040
2041         /* Maybe we can switch into bypass mode now. */
2042         ttydisc_optimize(tp);
2043
2044         /* Silently convert rint() calls to rint_bypass() when possible. */
2045         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
2046                 th->th_rint = ttyhook_defrint;
2047
2048 done3:  tty_unlock(tp);
2049 done2:  dev_relthread(dev, ref);
2050 done1:  fdrop(fp, curthread);
2051         return (error);
2052 }
2053
2054 void
2055 ttyhook_unregister(struct tty *tp)
2056 {
2057
2058         tty_lock_assert(tp, MA_OWNED);
2059         MPASS(tp->t_flags & TF_HOOK);
2060
2061         /* Disconnect the hook. */
2062         tp->t_flags &= ~TF_HOOK;
2063         tp->t_hook = NULL;
2064
2065         /* Maybe we need to leave bypass mode. */
2066         ttydisc_optimize(tp);
2067
2068         /* Maybe deallocate the TTY as well. */
2069         tty_rel_free(tp);
2070 }
2071
2072 /*
2073  * /dev/console handling.
2074  */
2075
2076 static int
2077 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2078 {
2079         struct tty *tp;
2080
2081         /* System has no console device. */
2082         if (dev_console_filename == NULL)
2083                 return (ENXIO);
2084
2085         /* Look up corresponding TTY by device name. */
2086         sx_slock(&tty_list_sx);
2087         TAILQ_FOREACH(tp, &tty_list, t_list) {
2088                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2089                         dev_console->si_drv1 = tp;
2090                         break;
2091                 }
2092         }
2093         sx_sunlock(&tty_list_sx);
2094
2095         /* System console has no TTY associated. */
2096         if (dev_console->si_drv1 == NULL)
2097                 return (ENXIO);
2098
2099         return (ttydev_open(dev, oflags, devtype, td));
2100 }
2101
2102 static int
2103 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2104 {
2105
2106         log_console(uio);
2107
2108         return (ttydev_write(dev, uio, ioflag));
2109 }
2110
2111 /*
2112  * /dev/console is a little different than normal TTY's.  When opened,
2113  * it determines which TTY to use.  When data gets written to it, it
2114  * will be logged in the kernel message buffer.
2115  */
2116 static struct cdevsw ttyconsdev_cdevsw = {
2117         .d_version      = D_VERSION,
2118         .d_open         = ttyconsdev_open,
2119         .d_close        = ttydev_close,
2120         .d_read         = ttydev_read,
2121         .d_write        = ttyconsdev_write,
2122         .d_ioctl        = ttydev_ioctl,
2123         .d_kqfilter     = ttydev_kqfilter,
2124         .d_poll         = ttydev_poll,
2125         .d_mmap         = ttydev_mmap,
2126         .d_name         = "ttyconsdev",
2127         .d_flags        = D_TTY,
2128 };
2129
2130 static void
2131 ttyconsdev_init(void *unused __unused)
2132 {
2133
2134         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2135             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2136 }
2137
2138 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2139
2140 void
2141 ttyconsdev_select(const char *name)
2142 {
2143
2144         dev_console_filename = name;
2145 }
2146
2147 /*
2148  * Debugging routines.
2149  */
2150
2151 #include "opt_ddb.h"
2152 #ifdef DDB
2153 #include <ddb/ddb.h>
2154 #include <ddb/db_sym.h>
2155
2156 static const struct {
2157         int flag;
2158         char val;
2159 } ttystates[] = {
2160 #if 0
2161         { TF_NOPREFIX,          'N' },
2162 #endif
2163         { TF_INITLOCK,          'I' },
2164         { TF_CALLOUT,           'C' },
2165
2166         /* Keep these together -> 'Oi' and 'Oo'. */
2167         { TF_OPENED,            'O' },
2168         { TF_OPENED_IN,         'i' },
2169         { TF_OPENED_OUT,        'o' },
2170         { TF_OPENED_CONS,       'c' },
2171
2172         { TF_GONE,              'G' },
2173         { TF_OPENCLOSE,         'B' },
2174         { TF_ASYNC,             'Y' },
2175         { TF_LITERAL,           'L' },
2176
2177         /* Keep these together -> 'Hi' and 'Ho'. */
2178         { TF_HIWAT,             'H' },
2179         { TF_HIWAT_IN,          'i' },
2180         { TF_HIWAT_OUT,         'o' },
2181
2182         { TF_STOPPED,           'S' },
2183         { TF_EXCLUDE,           'X' },
2184         { TF_BYPASS,            'l' },
2185         { TF_ZOMBIE,            'Z' },
2186         { TF_HOOK,              's' },
2187
2188         /* Keep these together -> 'bi' and 'bo'. */
2189         { TF_BUSY,              'b' },
2190         { TF_BUSY_IN,           'i' },
2191         { TF_BUSY_OUT,          'o' },
2192
2193         { 0,                    '\0'},
2194 };
2195
2196 #define TTY_FLAG_BITS \
2197         "\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2198         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2199         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2200         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2201         "\21HOOK\22BUSY_IN\23BUSY_OUT"
2202
2203 #define DB_PRINTSYM(name, addr) \
2204         db_printf("%s  " #name ": ", sep); \
2205         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2206         db_printf("\n");
2207
2208 static void
2209 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2210 {
2211
2212         db_printf("%sdevsw: ", sep);
2213         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2214         db_printf(" (%p)\n", tsw);
2215         DB_PRINTSYM(open, tsw->tsw_open);
2216         DB_PRINTSYM(close, tsw->tsw_close);
2217         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2218         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2219         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2220         DB_PRINTSYM(param, tsw->tsw_param);
2221         DB_PRINTSYM(modem, tsw->tsw_modem);
2222         DB_PRINTSYM(mmap, tsw->tsw_mmap);
2223         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2224         DB_PRINTSYM(free, tsw->tsw_free);
2225 }
2226
2227 static void
2228 _db_show_hooks(const char *sep, const struct ttyhook *th)
2229 {
2230
2231         db_printf("%shook: ", sep);
2232         db_printsym((db_addr_t)th, DB_STGY_ANY);
2233         db_printf(" (%p)\n", th);
2234         if (th == NULL)
2235                 return;
2236         DB_PRINTSYM(rint, th->th_rint);
2237         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2238         DB_PRINTSYM(rint_done, th->th_rint_done);
2239         DB_PRINTSYM(rint_poll, th->th_rint_poll);
2240         DB_PRINTSYM(getc_inject, th->th_getc_inject);
2241         DB_PRINTSYM(getc_capture, th->th_getc_capture);
2242         DB_PRINTSYM(getc_poll, th->th_getc_poll);
2243         DB_PRINTSYM(close, th->th_close);
2244 }
2245
2246 static void
2247 _db_show_termios(const char *name, const struct termios *t)
2248 {
2249
2250         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2251             "lflag 0x%x ispeed %u ospeed %u\n", name,
2252             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2253             t->c_ispeed, t->c_ospeed);
2254 }
2255
2256 /* DDB command to show TTY statistics. */
2257 DB_SHOW_COMMAND(tty, db_show_tty)
2258 {
2259         struct tty *tp;
2260
2261         if (!have_addr) {
2262                 db_printf("usage: show tty <addr>\n");
2263                 return;
2264         }
2265         tp = (struct tty *)addr;
2266
2267         db_printf("%p: %s\n", tp, tty_devname(tp));
2268         db_printf("\tmtx: %p\n", tp->t_mtx);
2269         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2270         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2271
2272         /* Buffering mechanisms. */
2273         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2274             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2275             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2276             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2277         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2278             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2279             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2280         db_printf("\tinlow: %zu\n", tp->t_inlow);
2281         db_printf("\toutlow: %zu\n", tp->t_outlow);
2282         _db_show_termios("\ttermios", &tp->t_termios);
2283         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2284             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2285             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2286         db_printf("\tcolumn: %u\n", tp->t_column);
2287         db_printf("\twritepos: %u\n", tp->t_writepos);
2288         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2289
2290         /* Init/lock-state devices. */
2291         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2292         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2293         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2294         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2295
2296         /* Hooks */
2297         _db_show_devsw("\t", tp->t_devsw);
2298         _db_show_hooks("\t", tp->t_hook);
2299
2300         /* Process info. */
2301         db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2302             tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2303             tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2304         db_printf("\tsession: %p", tp->t_session);
2305         if (tp->t_session != NULL)
2306             db_printf(" count %u leader %p tty %p sid %d login %s",
2307                 tp->t_session->s_count, tp->t_session->s_leader,
2308                 tp->t_session->s_ttyp, tp->t_session->s_sid,
2309                 tp->t_session->s_login);
2310         db_printf("\n");
2311         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2312         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2313         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2314         db_printf("\tdev: %p\n", tp->t_dev);
2315 }
2316
2317 /* DDB command to list TTYs. */
2318 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2319 {
2320         struct tty *tp;
2321         size_t isiz, osiz;
2322         int i, j;
2323
2324         /* Make the output look like `pstat -t'. */
2325         db_printf("PTR        ");
2326 #if defined(__LP64__)
2327         db_printf("        ");
2328 #endif
2329         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2330             "COL  SESS  PGID STATE\n");
2331
2332         TAILQ_FOREACH(tp, &tty_list, t_list) {
2333                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2334                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2335
2336                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2337                     "%5d ", tp, tty_devname(tp), isiz,
2338                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2339                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2340                     isiz - tp->t_inlow, osiz,
2341                     tp->t_outq.to_end - tp->t_outq.to_begin,
2342                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2343                     tp->t_session ? tp->t_session->s_sid : 0,
2344                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2345
2346                 /* Flag bits. */
2347                 for (i = j = 0; ttystates[i].flag; i++)
2348                         if (tp->t_flags & ttystates[i].flag) {
2349                                 db_printf("%c", ttystates[i].val);
2350                                 j++;
2351                         }
2352                 if (j == 0)
2353                         db_printf("-");
2354                 db_printf("\n");
2355         }
2356 }
2357 #endif /* DDB */