sys/kern/tty.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   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 #include "opt_capsicum.h"
  34 #include "opt_printf.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 <fs/devfs/devfs.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|INLCR|\
  89                         IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL|IUTF8)
  90 #define TTYSUP_OFLAG    (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
  91 #define TTYSUP_LFLAG    (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
  92                         ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
  93                         FLUSHO|NOKERNINFO|NOFLSH)
  94 #define TTYSUP_CFLAG    (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
  95                         HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
  96                         CDSR_OFLOW|CCAR_OFLOW|CNO_RTSDTR)
  97
  98 #define TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
  99
 100 static int  tty_drainwait = 5 * 60;
 101 SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
 102     &tty_drainwait, 0, "Default output drain timeout in seconds");
 103
 104 /*
 105  * Set TTY buffer sizes.
 106  */
 107
 108 #define TTYBUF_MAX      65536
 109
 110 #ifdef PRINTF_BUFR_SIZE
 111 #define TTY_PRBUF_SIZE  PRINTF_BUFR_SIZE
 112 #else
 113 #define TTY_PRBUF_SIZE  256
 114 #endif
 115
 116 /*
 117  * Allocate buffer space if necessary, and set low watermarks, based on speed.
 118  * Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
 119  * lock during memory allocation.  They will return ENXIO if the tty disappears
 120  * while unlocked.
 121  */
 122 static int
 123 tty_watermarks(struct tty *tp)
 124 {
 125         size_t bs = 0;
 126         int error;
 127
 128         /* Provide an input buffer for 2 seconds of data. */
 129         if (tp->t_termios.c_cflag & CREAD)
 130                 bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
 131         error = ttyinq_setsize(&tp->t_inq, tp, bs);
 132         if (error != 0)
 133                 return (error);
 134
 135         /* Set low watermark at 10% (when 90% is available). */
 136         tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
 137
 138         /* Provide an output buffer for 2 seconds of data. */
 139         bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
 140         error = ttyoutq_setsize(&tp->t_outq, tp, bs);
 141         if (error != 0)
 142                 return (error);
 143
 144         /* Set low watermark at 10% (when 90% is available). */
 145         tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
 146
 147         return (0);
 148 }
 149
 150 static int
 151 tty_drain(struct tty *tp, int leaving)
 152 {
 153         sbintime_t timeout_at;
 154         size_t bytes;
 155         int error;
 156
 157         if (ttyhook_hashook(tp, getc_inject))
 158                 /* buffer is inaccessible */
 159                 return (0);
 160
 161         /*
 162          * For close(), use the recent historic timeout of "1 second without
 163          * making progress".  For tcdrain(), use t_drainwait as the timeout,
 164          * with zero meaning "no timeout" which gives POSIX behavior.
 165          */
 166         if (leaving)
 167                 timeout_at = getsbinuptime() + SBT_1S;
 168         else if (tp->t_drainwait != 0)
 169                 timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
 170         else
 171                 timeout_at = 0;
 172
 173         /*
 174          * Poll the output buffer and the hardware for completion, at 10 Hz.
 175          * Polling is required for devices which are not able to signal an
 176          * interrupt when the transmitter becomes idle (most USB serial devs).
 177          * The unusual structure of this loop ensures we check for busy one more
 178          * time after tty_timedwait() returns EWOULDBLOCK, so that success has
 179          * higher priority than timeout if the IO completed in the last 100mS.
 180          */
 181         error = 0;
 182         bytes = ttyoutq_bytesused(&tp->t_outq);
 183         for (;;) {
 184                 if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
 185                         return (0);
 186                 if (error != 0)
 187                         return (error);
 188                 ttydevsw_outwakeup(tp);
 189                 error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
 190                 if (error != 0 && error != EWOULDBLOCK)
 191                         return (error);
 192                 else if (timeout_at == 0 || getsbinuptime() < timeout_at)
 193                         error = 0;
 194                 else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
 195                         /* In close, making progress, grant an extra second. */
 196                         error = 0;
 197                         timeout_at += SBT_1S;
 198                         bytes = ttyoutq_bytesused(&tp->t_outq);
 199                 }
 200         }
 201 }
 202
 203 /*
 204  * Though ttydev_enter() and ttydev_leave() seem to be related, they
 205  * don't have to be used together. ttydev_enter() is used by the cdev
 206  * operations to prevent an actual operation from being processed when
 207  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
 208  * and ttydev_close() to determine whether per-TTY data should be
 209  * deallocated.
 210  */
 211
 212 static __inline int
 213 ttydev_enter(struct tty *tp)
 214 {
 215
 216         tty_lock(tp);
 217
 218         if (tty_gone(tp) || !tty_opened(tp)) {
 219                 /* Device is already gone. */
 220                 tty_unlock(tp);
 221                 return (ENXIO);
 222         }
 223
 224         return (0);
 225 }
 226
 227 static void
 228 ttydev_leave(struct tty *tp)
 229 {
 230
 231         tty_assert_locked(tp);
 232
 233         if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
 234                 /* Device is still opened somewhere. */
 235                 tty_unlock(tp);
 236                 return;
 237         }
 238
 239         tp->t_flags |= TF_OPENCLOSE;
 240
 241         /* Remove console TTY. */
 242         constty_clear(tp);
 243
 244         /* Drain any output. */
 245         if (!tty_gone(tp))
 246                 tty_drain(tp, 1);
 247
 248         ttydisc_close(tp);
 249
 250         /* Free i/o queues now since they might be large. */
 251         ttyinq_free(&tp->t_inq);
 252         tp->t_inlow = 0;
 253         ttyoutq_free(&tp->t_outq);
 254         tp->t_outlow = 0;
 255
 256         if (!tty_gone(tp))
 257                 ttydevsw_close(tp);
 258
 259         tp->t_flags &= ~TF_OPENCLOSE;
 260         cv_broadcast(&tp->t_dcdwait);
 261         tty_rel_free(tp);
 262 }
 263
 264 /*
 265  * Operations that are exposed through the character device in /dev.
 266  */
 267 static int
 268 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
 269     struct thread *td)
 270 {
 271         struct tty *tp;
 272         int error;
 273
 274         tp = dev->si_drv1;
 275         error = 0;
 276         tty_lock(tp);
 277         if (tty_gone(tp)) {
 278                 /* Device is already gone. */
 279                 tty_unlock(tp);
 280                 return (ENXIO);
 281         }
 282
 283         /*
 284          * Block when other processes are currently opening or closing
 285          * the TTY.
 286          */
 287         while (tp->t_flags & TF_OPENCLOSE) {
 288                 error = tty_wait(tp, &tp->t_dcdwait);
 289                 if (error != 0) {
 290                         tty_unlock(tp);
 291                         return (error);
 292                 }
 293         }
 294         tp->t_flags |= TF_OPENCLOSE;
 295
 296         /*
 297          * Make sure the "tty" and "cua" device cannot be opened at the
 298          * same time.  The console is a "tty" device.
 299          */
 300         if (TTY_CALLOUT(tp, dev)) {
 301                 if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
 302                         error = EBUSY;
 303                         goto done;
 304                 }
 305         } else {
 306                 if (tp->t_flags & TF_OPENED_OUT) {
 307                         error = EBUSY;
 308                         goto done;
 309                 }
 310         }
 311
 312         if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
 313                 error = EBUSY;
 314                 goto done;
 315         }
 316
 317         if (!tty_opened(tp)) {
 318                 /* Set proper termios flags. */
 319                 if (TTY_CALLOUT(tp, dev))
 320                         tp->t_termios = tp->t_termios_init_out;
 321                 else
 322                         tp->t_termios = tp->t_termios_init_in;
 323                 ttydevsw_param(tp, &tp->t_termios);
 324                 /* Prevent modem control on callout devices and /dev/console. */
 325                 if (TTY_CALLOUT(tp, dev) || dev == dev_console)
 326                         tp->t_termios.c_cflag |= CLOCAL;
 327
 328                 if ((tp->t_termios.c_cflag & CNO_RTSDTR) == 0)
 329                         ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
 330
 331                 error = ttydevsw_open(tp);
 332                 if (error != 0)
 333                         goto done;
 334
 335                 ttydisc_open(tp);
 336                 error = tty_watermarks(tp);
 337                 if (error != 0)
 338                         goto done;
 339         }
 340
 341         /* Wait for Carrier Detect. */
 342         if ((oflags & O_NONBLOCK) == 0 &&
 343             (tp->t_termios.c_cflag & CLOCAL) == 0) {
 344                 while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
 345                         error = tty_wait(tp, &tp->t_dcdwait);
 346                         if (error != 0)
 347                                 goto done;
 348                 }
 349         }
 350
 351         if (dev == dev_console)
 352                 tp->t_flags |= TF_OPENED_CONS;
 353         else if (TTY_CALLOUT(tp, dev))
 354                 tp->t_flags |= TF_OPENED_OUT;
 355         else
 356                 tp->t_flags |= TF_OPENED_IN;
 357         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 358             (tp->t_flags & TF_OPENED_OUT) == 0);
 359
 360 done:   tp->t_flags &= ~TF_OPENCLOSE;
 361         cv_broadcast(&tp->t_dcdwait);
 362         ttydev_leave(tp);
 363
 364         return (error);
 365 }
 366
 367 static int
 368 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
 369     struct thread *td)
 370 {
 371         struct tty *tp = dev->si_drv1;
 372
 373         tty_lock(tp);
 374
 375         /*
 376          * Don't actually close the device if it is being used as the
 377          * console.
 378          */
 379         MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
 380             (tp->t_flags & TF_OPENED_OUT) == 0);
 381         if (dev == dev_console)
 382                 tp->t_flags &= ~TF_OPENED_CONS;
 383         else
 384                 tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
 385
 386         if (tp->t_flags & TF_OPENED) {
 387                 tty_unlock(tp);
 388                 return (0);
 389         }
 390
 391         /* If revoking, flush output now to avoid draining it later. */
 392         if ((fflag & FREVOKE) != 0) {
 393                 tty_flush(tp, FWRITE);
 394                 knlist_delete(&tp->t_inpoll.si_note, td, 1);
 395                 knlist_delete(&tp->t_outpoll.si_note, td, 1);
 396         }
 397
 398         tp->t_flags &= ~TF_EXCLUDE;
 399
 400         /* Properly wake up threads that are stuck - revoke(). */
 401         tp->t_revokecnt++;
 402         tty_wakeup(tp, FREAD|FWRITE);
 403         cv_broadcast(&tp->t_bgwait);
 404         cv_broadcast(&tp->t_dcdwait);
 405
 406         ttydev_leave(tp);
 407
 408         return (0);
 409 }
 410
 411 static __inline int
 412 tty_is_ctty(struct tty *tp, struct proc *p)
 413 {
 414
 415         tty_assert_locked(tp);
 416
 417         return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
 418 }
 419
 420 int
 421 tty_wait_background(struct tty *tp, struct thread *td, int sig)
 422 {
 423         struct proc *p;
 424         struct pgrp *pg;
 425         ksiginfo_t ksi;
 426         int error;
 427
 428         MPASS(sig == SIGTTIN || sig == SIGTTOU);
 429         tty_assert_locked(tp);
 430
 431         p = td->td_proc;
 432         for (;;) {
 433                 pg = p->p_pgrp;
 434                 PGRP_LOCK(pg);
 435                 PROC_LOCK(p);
 436
 437                 /*
 438                  * pg may no longer be our process group.
 439                  * Re-check after locking.
 440                  */
 441                 if (p->p_pgrp != pg) {
 442                         PROC_UNLOCK(p);
 443                         PGRP_UNLOCK(pg);
 444                         continue;
 445                 }
 446
 447                 /*
 448                  * The process should only sleep, when:
 449                  * - This terminal is the controlling terminal
 450                  * - Its process group is not the foreground process
 451                  *   group
 452                  * - The parent process isn't waiting for the child to
 453                  *   exit
 454                  * - the signal to send to the process isn't masked
 455                  */
 456                 if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
 457                         /* Allow the action to happen. */
 458                         PROC_UNLOCK(p);
 459                         PGRP_UNLOCK(pg);
 460                         return (0);
 461                 }
 462
 463                 if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
 464                     SIGISMEMBER(td->td_sigmask, sig)) {
 465                         /* Only allow them in write()/ioctl(). */
 466                         PROC_UNLOCK(p);
 467                         PGRP_UNLOCK(pg);
 468                         return (sig == SIGTTOU ? 0 : EIO);
 469                 }
 470
 471                 if ((p->p_flag & P_PPWAIT) != 0 ||
 472                     (pg->pg_flags & PGRP_ORPHANED) != 0) {
 473                         /* Don't allow the action to happen. */
 474                         PROC_UNLOCK(p);
 475                         PGRP_UNLOCK(pg);
 476                         return (EIO);
 477                 }
 478                 PROC_UNLOCK(p);
 479
 480                 /*
 481                  * Send the signal and sleep until we're the new
 482                  * foreground process group.
 483                  */
 484                 if (sig != 0) {
 485                         ksiginfo_init(&ksi);
 486                         ksi.ksi_code = SI_KERNEL;
 487                         ksi.ksi_signo = sig;
 488                         sig = 0;
 489                 }
 490
 491                 pgsignal(pg, ksi.ksi_signo, 1, &ksi);
 492                 PGRP_UNLOCK(pg);
 493
 494                 error = tty_wait(tp, &tp->t_bgwait);
 495                 if (error)
 496                         return (error);
 497         }
 498 }
 499
 500 static int
 501 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
 502 {
 503         struct tty *tp = dev->si_drv1;
 504         int error;
 505
 506         error = ttydev_enter(tp);
 507         if (error)
 508                 goto done;
 509         error = ttydisc_read(tp, uio, ioflag);
 510         tty_unlock(tp);
 511
 512         /*
 513          * The read() call should not throw an error when the device is
 514          * being destroyed. Silently convert it to an EOF.
 515          */
 516 done:   if (error == ENXIO)
 517                 error = 0;
 518         return (error);
 519 }
 520
 521 static int
 522 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
 523 {
 524         struct tty *tp = dev->si_drv1;
 525         int defer, error;
 526
 527         error = ttydev_enter(tp);
 528         if (error)
 529                 return (error);
 530
 531         if (tp->t_termios.c_lflag & TOSTOP) {
 532                 error = tty_wait_background(tp, curthread, SIGTTOU);
 533                 if (error)
 534                         goto done;
 535         }
 536
 537         if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
 538                 /* Allow non-blocking writes to bypass serialization. */
 539                 error = ttydisc_write(tp, uio, ioflag);
 540         } else {
 541                 /* Serialize write() calls. */
 542                 while (tp->t_flags & TF_BUSY_OUT) {
 543                         error = tty_wait(tp, &tp->t_outserwait);
 544                         if (error)
 545                                 goto done;
 546                 }
 547
 548                 tp->t_flags |= TF_BUSY_OUT;
 549                 defer = sigdeferstop(SIGDEFERSTOP_ERESTART);
 550                 error = ttydisc_write(tp, uio, ioflag);
 551                 sigallowstop(defer);
 552                 tp->t_flags &= ~TF_BUSY_OUT;
 553                 cv_signal(&tp->t_outserwait);
 554         }
 555
 556 done:   tty_unlock(tp);
 557         return (error);
 558 }
 559
 560 static int
 561 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 562     struct thread *td)
 563 {
 564         struct tty *tp = dev->si_drv1;
 565         int error;
 566
 567         error = ttydev_enter(tp);
 568         if (error)
 569                 return (error);
 570
 571         switch (cmd) {
 572         case TIOCCBRK:
 573         case TIOCCONS:
 574         case TIOCDRAIN:
 575         case TIOCEXCL:
 576         case TIOCFLUSH:
 577         case TIOCNXCL:
 578         case TIOCSBRK:
 579         case TIOCSCTTY:
 580         case TIOCSETA:
 581         case TIOCSETAF:
 582         case TIOCSETAW:
 583         case TIOCSPGRP:
 584         case TIOCSTART:
 585         case TIOCSTAT:
 586         case TIOCSTI:
 587         case TIOCSTOP:
 588         case TIOCSWINSZ:
 589 #if 0
 590         case TIOCSDRAINWAIT:
 591         case TIOCSETD:
 592 #endif
 593 #ifdef COMPAT_43TTY
 594         case  TIOCLBIC:
 595         case  TIOCLBIS:
 596         case  TIOCLSET:
 597         case  TIOCSETC:
 598         case OTIOCSETD:
 599         case  TIOCSETN:
 600         case  TIOCSETP:
 601         case  TIOCSLTC:
 602 #endif /* COMPAT_43TTY */
 603                 /*
 604                  * If the ioctl() causes the TTY to be modified, let it
 605                  * wait in the background.
 606                  */
 607                 error = tty_wait_background(tp, curthread, SIGTTOU);
 608                 if (error)
 609                         goto done;
 610         }
 611
 612         if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 613                 struct termios *old = &tp->t_termios;
 614                 struct termios *new = (struct termios *)data;
 615                 struct termios *lock = TTY_CALLOUT(tp, dev) ?
 616                     &tp->t_termios_lock_out : &tp->t_termios_lock_in;
 617                 int cc;
 618
 619                 /*
 620                  * Lock state devices.  Just overwrite the values of the
 621                  * commands that are currently in use.
 622                  */
 623                 new->c_iflag = (old->c_iflag & lock->c_iflag) |
 624                     (new->c_iflag & ~lock->c_iflag);
 625                 new->c_oflag = (old->c_oflag & lock->c_oflag) |
 626                     (new->c_oflag & ~lock->c_oflag);
 627                 new->c_cflag = (old->c_cflag & lock->c_cflag) |
 628                     (new->c_cflag & ~lock->c_cflag);
 629                 new->c_lflag = (old->c_lflag & lock->c_lflag) |
 630                     (new->c_lflag & ~lock->c_lflag);
 631                 for (cc = 0; cc < NCCS; ++cc)
 632                         if (lock->c_cc[cc])
 633                                 new->c_cc[cc] = old->c_cc[cc];
 634                 if (lock->c_ispeed)
 635                         new->c_ispeed = old->c_ispeed;
 636                 if (lock->c_ospeed)
 637                         new->c_ospeed = old->c_ospeed;
 638         }
 639
 640         error = tty_ioctl(tp, cmd, data, fflag, td);
 641 done:   tty_unlock(tp);
 642
 643         return (error);
 644 }
 645
 646 static int
 647 ttydev_poll(struct cdev *dev, int events, struct thread *td)
 648 {
 649         struct tty *tp = dev->si_drv1;
 650         int error, revents = 0;
 651
 652         error = ttydev_enter(tp);
 653         if (error)
 654                 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
 655
 656         if (events & (POLLIN|POLLRDNORM)) {
 657                 /* See if we can read something. */
 658                 if (ttydisc_read_poll(tp) > 0)
 659                         revents |= events & (POLLIN|POLLRDNORM);
 660         }
 661
 662         if (tp->t_flags & TF_ZOMBIE) {
 663                 /* Hangup flag on zombie state. */
 664                 revents |= POLLHUP;
 665         } else if (events & (POLLOUT|POLLWRNORM)) {
 666                 /* See if we can write something. */
 667                 if (ttydisc_write_poll(tp) > 0)
 668                         revents |= events & (POLLOUT|POLLWRNORM);
 669         }
 670
 671         if (revents == 0) {
 672                 if (events & (POLLIN|POLLRDNORM))
 673                         selrecord(td, &tp->t_inpoll);
 674                 if (events & (POLLOUT|POLLWRNORM))
 675                         selrecord(td, &tp->t_outpoll);
 676         }
 677
 678         tty_unlock(tp);
 679
 680         return (revents);
 681 }
 682
 683 static int
 684 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
 685     int nprot, vm_memattr_t *memattr)
 686 {
 687         struct tty *tp = dev->si_drv1;
 688         int error;
 689
 690         /* Handle mmap() through the driver. */
 691
 692         error = ttydev_enter(tp);
 693         if (error)
 694                 return (-1);
 695         error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
 696         tty_unlock(tp);
 697
 698         return (error);
 699 }
 700
 701 /*
 702  * kqueue support.
 703  */
 704
 705 static void
 706 tty_kqops_read_detach(struct knote *kn)
 707 {
 708         struct tty *tp = kn->kn_hook;
 709
 710         knlist_remove(&tp->t_inpoll.si_note, kn, 0);
 711 }
 712
 713 static int
 714 tty_kqops_read_event(struct knote *kn, long hint __unused)
 715 {
 716         struct tty *tp = kn->kn_hook;
 717
 718         tty_assert_locked(tp);
 719
 720         if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
 721                 kn->kn_flags |= EV_EOF;
 722                 return (1);
 723         } else {
 724                 kn->kn_data = ttydisc_read_poll(tp);
 725                 return (kn->kn_data > 0);
 726         }
 727 }
 728
 729 static void
 730 tty_kqops_write_detach(struct knote *kn)
 731 {
 732         struct tty *tp = kn->kn_hook;
 733
 734         knlist_remove(&tp->t_outpoll.si_note, kn, 0);
 735 }
 736
 737 static int
 738 tty_kqops_write_event(struct knote *kn, long hint __unused)
 739 {
 740         struct tty *tp = kn->kn_hook;
 741
 742         tty_assert_locked(tp);
 743
 744         if (tty_gone(tp)) {
 745                 kn->kn_flags |= EV_EOF;
 746                 return (1);
 747         } else {
 748                 kn->kn_data = ttydisc_write_poll(tp);
 749                 return (kn->kn_data > 0);
 750         }
 751 }
 752
 753 static struct filterops tty_kqops_read = {
 754         .f_isfd = 1,
 755         .f_detach = tty_kqops_read_detach,
 756         .f_event = tty_kqops_read_event,
 757 };
 758
 759 static struct filterops tty_kqops_write = {
 760         .f_isfd = 1,
 761         .f_detach = tty_kqops_write_detach,
 762         .f_event = tty_kqops_write_event,
 763 };
 764
 765 static int
 766 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
 767 {
 768         struct tty *tp = dev->si_drv1;
 769         int error;
 770
 771         error = ttydev_enter(tp);
 772         if (error)
 773                 return (error);
 774
 775         switch (kn->kn_filter) {
 776         case EVFILT_READ:
 777                 kn->kn_hook = tp;
 778                 kn->kn_fop = &tty_kqops_read;
 779                 knlist_add(&tp->t_inpoll.si_note, kn, 1);
 780                 break;
 781         case EVFILT_WRITE:
 782                 kn->kn_hook = tp;
 783                 kn->kn_fop = &tty_kqops_write;
 784                 knlist_add(&tp->t_outpoll.si_note, kn, 1);
 785                 break;
 786         default:
 787                 error = EINVAL;
 788                 break;
 789         }
 790
 791         tty_unlock(tp);
 792         return (error);
 793 }
 794
 795 static struct cdevsw ttydev_cdevsw = {
 796         .d_version      = D_VERSION,
 797         .d_open         = ttydev_open,
 798         .d_close        = ttydev_close,
 799         .d_read         = ttydev_read,
 800         .d_write        = ttydev_write,
 801         .d_ioctl        = ttydev_ioctl,
 802         .d_kqfilter     = ttydev_kqfilter,
 803         .d_poll         = ttydev_poll,
 804         .d_mmap         = ttydev_mmap,
 805         .d_name         = "ttydev",
 806         .d_flags        = D_TTY,
 807 };
 808
 809 /*
 810  * Init/lock-state devices
 811  */
 812
 813 static int
 814 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
 815     struct thread *td)
 816 {
 817         struct tty *tp;
 818         int error;
 819
 820         tp = dev->si_drv1;
 821         error = 0;
 822         tty_lock(tp);
 823         if (tty_gone(tp))
 824                 error = ENODEV;
 825         tty_unlock(tp);
 826
 827         return (error);
 828 }
 829
 830 static int
 831 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
 832     struct thread *td __unused)
 833 {
 834
 835         return (0);
 836 }
 837
 838 static int
 839 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
 840     int ioflag __unused)
 841 {
 842
 843         return (ENODEV);
 844 }
 845
 846 static int
 847 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
 848     struct thread *td)
 849 {
 850         struct tty *tp = dev->si_drv1;
 851         int error;
 852
 853         tty_lock(tp);
 854         if (tty_gone(tp)) {
 855                 error = ENODEV;
 856                 goto done;
 857         }
 858
 859         error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
 860         if (error != ENOIOCTL)
 861                 goto done;
 862         error = 0;
 863
 864         switch (cmd) {
 865         case TIOCGETA:
 866                 /* Obtain terminal flags through tcgetattr(). */
 867                 *(struct termios*)data = *(struct termios*)dev->si_drv2;
 868                 break;
 869         case TIOCSETA:
 870                 /* Set terminal flags through tcsetattr(). */
 871                 error = priv_check(td, PRIV_TTY_SETA);
 872                 if (error)
 873                         break;
 874                 *(struct termios*)dev->si_drv2 = *(struct termios*)data;
 875                 break;
 876         case TIOCGETD:
 877                 *(int *)data = TTYDISC;
 878                 break;
 879         case TIOCGWINSZ:
 880                 bzero(data, sizeof(struct winsize));
 881                 break;
 882         default:
 883                 error = ENOTTY;
 884         }
 885
 886 done:   tty_unlock(tp);
 887         return (error);
 888 }
 889
 890 static struct cdevsw ttyil_cdevsw = {
 891         .d_version      = D_VERSION,
 892         .d_open         = ttyil_open,
 893         .d_close        = ttyil_close,
 894         .d_read         = ttyil_rdwr,
 895         .d_write        = ttyil_rdwr,
 896         .d_ioctl        = ttyil_ioctl,
 897         .d_name         = "ttyil",
 898         .d_flags        = D_TTY,
 899 };
 900
 901 static void
 902 tty_init_termios(struct tty *tp)
 903 {
 904         struct termios *t = &tp->t_termios_init_in;
 905
 906         t->c_cflag = TTYDEF_CFLAG;
 907         t->c_iflag = TTYDEF_IFLAG;
 908         t->c_lflag = TTYDEF_LFLAG;
 909         t->c_oflag = TTYDEF_OFLAG;
 910         t->c_ispeed = TTYDEF_SPEED;
 911         t->c_ospeed = TTYDEF_SPEED;
 912         memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
 913
 914         tp->t_termios_init_out = *t;
 915 }
 916
 917 void
 918 tty_init_console(struct tty *tp, speed_t s)
 919 {
 920         struct termios *ti = &tp->t_termios_init_in;
 921         struct termios *to = &tp->t_termios_init_out;
 922
 923         if (s != 0) {
 924                 ti->c_ispeed = ti->c_ospeed = s;
 925                 to->c_ispeed = to->c_ospeed = s;
 926         }
 927
 928         ti->c_cflag |= CLOCAL;
 929         to->c_cflag |= CLOCAL;
 930 }
 931
 932 /*
 933  * Standard device routine implementations, mostly meant for
 934  * pseudo-terminal device drivers. When a driver creates a new terminal
 935  * device class, missing routines are patched.
 936  */
 937
 938 static int
 939 ttydevsw_defopen(struct tty *tp __unused)
 940 {
 941
 942         return (0);
 943 }
 944
 945 static void
 946 ttydevsw_defclose(struct tty *tp __unused)
 947 {
 948
 949 }
 950
 951 static void
 952 ttydevsw_defoutwakeup(struct tty *tp __unused)
 953 {
 954
 955         panic("Terminal device has output, while not implemented");
 956 }
 957
 958 static void
 959 ttydevsw_definwakeup(struct tty *tp __unused)
 960 {
 961
 962 }
 963
 964 static int
 965 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
 966     caddr_t data __unused, struct thread *td __unused)
 967 {
 968
 969         return (ENOIOCTL);
 970 }
 971
 972 static int
 973 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
 974     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
 975 {
 976
 977         return (ENOIOCTL);
 978 }
 979
 980 static int
 981 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
 982 {
 983
 984         /*
 985          * Allow the baud rate to be adjusted for pseudo-devices, but at
 986          * least restrict it to 115200 to prevent excessive buffer
 987          * usage.  Also disallow 0, to prevent foot shooting.
 988          */
 989         if (t->c_ispeed < B50)
 990                 t->c_ispeed = B50;
 991         else if (t->c_ispeed > B115200)
 992                 t->c_ispeed = B115200;
 993         if (t->c_ospeed < B50)
 994                 t->c_ospeed = B50;
 995         else if (t->c_ospeed > B115200)
 996                 t->c_ospeed = B115200;
 997         t->c_cflag |= CREAD;
 998
 999         return (0);
1000 }
1001
1002 static int
1003 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
1004     int sigoff __unused)
1005 {
1006
1007         /* Simulate a carrier to make the TTY layer happy. */
1008         return (SER_DCD);
1009 }
1010
1011 static int
1012 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
1013     vm_paddr_t *paddr __unused, int nprot __unused,
1014     vm_memattr_t *memattr __unused)
1015 {
1016
1017         return (-1);
1018 }
1019
1020 static void
1021 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
1022 {
1023
1024 }
1025
1026 static void
1027 ttydevsw_deffree(void *softc __unused)
1028 {
1029
1030         panic("Terminal device freed without a free-handler");
1031 }
1032
1033 static bool
1034 ttydevsw_defbusy(struct tty *tp __unused)
1035 {
1036
1037         return (FALSE);
1038 }
1039
1040 /*
1041  * TTY allocation and deallocation. TTY devices can be deallocated when
1042  * the driver doesn't use it anymore, when the TTY isn't a session's
1043  * controlling TTY and when the device node isn't opened through devfs.
1044  */
1045
1046 struct tty *
1047 tty_alloc(struct ttydevsw *tsw, void *sc)
1048 {
1049
1050         return (tty_alloc_mutex(tsw, sc, NULL));
1051 }
1052
1053 struct tty *
1054 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
1055 {
1056         struct tty *tp;
1057
1058         /* Make sure the driver defines all routines. */
1059 #define PATCH_FUNC(x) do {                              \
1060         if (tsw->tsw_ ## x == NULL)                     \
1061                 tsw->tsw_ ## x = ttydevsw_def ## x;     \
1062 } while (0)
1063         PATCH_FUNC(open);
1064         PATCH_FUNC(close);
1065         PATCH_FUNC(outwakeup);
1066         PATCH_FUNC(inwakeup);
1067         PATCH_FUNC(ioctl);
1068         PATCH_FUNC(cioctl);
1069         PATCH_FUNC(param);
1070         PATCH_FUNC(modem);
1071         PATCH_FUNC(mmap);
1072         PATCH_FUNC(pktnotify);
1073         PATCH_FUNC(free);
1074         PATCH_FUNC(busy);
1075 #undef PATCH_FUNC
1076
1077         tp = malloc(sizeof(struct tty) + TTY_PRBUF_SIZE, M_TTY,
1078             M_WAITOK | M_ZERO);
1079         tp->t_prbufsz = TTY_PRBUF_SIZE;
1080         tp->t_devsw = tsw;
1081         tp->t_devswsoftc = sc;
1082         tp->t_flags = tsw->tsw_flags;
1083         tp->t_drainwait = tty_drainwait;
1084
1085         tty_init_termios(tp);
1086
1087         cv_init(&tp->t_inwait, "ttyin");
1088         cv_init(&tp->t_outwait, "ttyout");
1089         cv_init(&tp->t_outserwait, "ttyosr");
1090         cv_init(&tp->t_bgwait, "ttybg");
1091         cv_init(&tp->t_dcdwait, "ttydcd");
1092
1093         /* Allow drivers to use a custom mutex to lock the TTY. */
1094         if (mutex != NULL) {
1095                 tp->t_mtx = mutex;
1096         } else {
1097                 tp->t_mtx = &tp->t_mtxobj;
1098                 mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1099         }
1100
1101         knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1102         knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1103
1104         return (tp);
1105 }
1106
1107 static void
1108 tty_dealloc(void *arg)
1109 {
1110         struct tty *tp = arg;
1111
1112         /*
1113          * ttyydev_leave() usually frees the i/o queues earlier, but it is
1114          * not always called between queue allocation and here.  The queues
1115          * may be allocated by ioctls on a pty control device without the
1116          * corresponding pty slave device ever being open, or after it is
1117          * closed.
1118          */
1119         ttyinq_free(&tp->t_inq);
1120         ttyoutq_free(&tp->t_outq);
1121         seldrain(&tp->t_inpoll);
1122         seldrain(&tp->t_outpoll);
1123         knlist_clear(&tp->t_inpoll.si_note, 0);
1124         knlist_clear(&tp->t_outpoll.si_note, 0);
1125         knlist_destroy(&tp->t_inpoll.si_note);
1126         knlist_destroy(&tp->t_outpoll.si_note);
1127
1128         cv_destroy(&tp->t_inwait);
1129         cv_destroy(&tp->t_outwait);
1130         cv_destroy(&tp->t_bgwait);
1131         cv_destroy(&tp->t_dcdwait);
1132         cv_destroy(&tp->t_outserwait);
1133
1134         if (tp->t_mtx == &tp->t_mtxobj)
1135                 mtx_destroy(&tp->t_mtxobj);
1136         ttydevsw_free(tp);
1137         free(tp, M_TTY);
1138 }
1139
1140 static void
1141 tty_rel_free(struct tty *tp)
1142 {
1143         struct cdev *dev;
1144
1145         tty_assert_locked(tp);
1146
1147 #define TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1148         if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1149                 /* TTY is still in use. */
1150                 tty_unlock(tp);
1151                 return;
1152         }
1153
1154         /* Stop asynchronous I/O. */
1155         funsetown(&tp->t_sigio);
1156
1157         /* TTY can be deallocated. */
1158         dev = tp->t_dev;
1159         tp->t_dev = NULL;
1160         tty_unlock(tp);
1161
1162         if (dev != NULL) {
1163                 sx_xlock(&tty_list_sx);
1164                 TAILQ_REMOVE(&tty_list, tp, t_list);
1165                 tty_list_count--;
1166                 sx_xunlock(&tty_list_sx);
1167                 destroy_dev_sched_cb(dev, tty_dealloc, tp);
1168         }
1169 }
1170
1171 void
1172 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1173 {
1174
1175         MPASS(tp->t_sessioncnt > 0);
1176         tty_assert_locked(tp);
1177
1178         if (tp->t_pgrp == pg)
1179                 tp->t_pgrp = NULL;
1180
1181         tty_unlock(tp);
1182 }
1183
1184 void
1185 tty_rel_sess(struct tty *tp, struct session *sess)
1186 {
1187
1188         MPASS(tp->t_sessioncnt > 0);
1189
1190         /* Current session has left. */
1191         if (tp->t_session == sess) {
1192                 tp->t_session = NULL;
1193                 MPASS(tp->t_pgrp == NULL);
1194         }
1195         tp->t_sessioncnt--;
1196         tty_rel_free(tp);
1197 }
1198
1199 void
1200 tty_rel_gone(struct tty *tp)
1201 {
1202
1203         tty_assert_locked(tp);
1204         MPASS(!tty_gone(tp));
1205
1206         /* Simulate carrier removal. */
1207         ttydisc_modem(tp, 0);
1208
1209         /* Wake up all blocked threads. */
1210         tty_wakeup(tp, FREAD|FWRITE);
1211         cv_broadcast(&tp->t_bgwait);
1212         cv_broadcast(&tp->t_dcdwait);
1213
1214         tp->t_flags |= TF_GONE;
1215         tty_rel_free(tp);
1216 }
1217
1218 static int
1219 tty_drop_ctty(struct tty *tp, struct proc *p)
1220 {
1221         struct session *session;
1222         struct vnode *vp;
1223
1224         /*
1225          * This looks terrible, but it's generally safe as long as the tty
1226          * hasn't gone away while we had the lock dropped.  All of our sanity
1227          * checking that this operation is OK happens after we've picked it back
1228          * up, so other state changes are generally not fatal and the potential
1229          * for this particular operation to happen out-of-order in a
1230          * multithreaded scenario is likely a non-issue.
1231          */
1232         tty_unlock(tp);
1233         sx_xlock(&proctree_lock);
1234         tty_lock(tp);
1235         if (tty_gone(tp)) {
1236                 sx_xunlock(&proctree_lock);
1237                 return (ENODEV);
1238         }
1239
1240         /*
1241          * If the session doesn't have a controlling TTY, or if we weren't
1242          * invoked on the controlling TTY, we'll return ENOIOCTL as we've
1243          * historically done.
1244          */
1245         session = p->p_session;
1246         if (session->s_ttyp == NULL || session->s_ttyp != tp) {
1247                 sx_xunlock(&proctree_lock);
1248                 return (ENOTTY);
1249         }
1250
1251         if (!SESS_LEADER(p)) {
1252                 sx_xunlock(&proctree_lock);
1253                 return (EPERM);
1254         }
1255
1256         PROC_LOCK(p);
1257         SESS_LOCK(session);
1258         vp = session->s_ttyvp;
1259         session->s_ttyp = NULL;
1260         session->s_ttyvp = NULL;
1261         session->s_ttydp = NULL;
1262         SESS_UNLOCK(session);
1263
1264         tp->t_sessioncnt--;
1265         p->p_flag &= ~P_CONTROLT;
1266         PROC_UNLOCK(p);
1267         sx_xunlock(&proctree_lock);
1268
1269         /*
1270          * If we did have a vnode, release our reference.  Ordinarily we manage
1271          * these at the devfs layer, but we can't necessarily know that we were
1272          * invoked on the vnode referenced in the session (i.e. the vnode we
1273          * hold a reference to).  We explicitly don't check VBAD/VIRF_DOOMED here
1274          * to avoid a vnode leak -- in circumstances elsewhere where we'd hit a
1275          * VIRF_DOOMED vnode, release has been deferred until the controlling TTY
1276          * is either changed or released.
1277          */
1278         if (vp != NULL)
1279                 devfs_ctty_unref(vp);
1280         return (0);
1281 }
1282
1283 /*
1284  * Exposing information about current TTY's through sysctl
1285  */
1286
1287 static void
1288 tty_to_xtty(struct tty *tp, struct xtty *xt)
1289 {
1290
1291         tty_assert_locked(tp);
1292
1293         memset(xt, 0, sizeof(*xt));
1294         xt->xt_size = sizeof(struct xtty);
1295         xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1296         xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1297         xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1298         xt->xt_inlow = tp->t_inlow;
1299         xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1300         xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1301         xt->xt_outlow = tp->t_outlow;
1302         xt->xt_column = tp->t_column;
1303         xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1304         xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1305         xt->xt_flags = tp->t_flags;
1306         xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : (uint32_t)NODEV;
1307 }
1308
1309 static int
1310 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1311 {
1312         unsigned long lsize;
1313         struct thread *td = curthread;
1314         struct xtty *xtlist, *xt;
1315         struct tty *tp;
1316         struct proc *p;
1317         int cansee, error;
1318
1319         sx_slock(&tty_list_sx);
1320         lsize = tty_list_count * sizeof(struct xtty);
1321         if (lsize == 0) {
1322                 sx_sunlock(&tty_list_sx);
1323                 return (0);
1324         }
1325
1326         xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1327
1328         TAILQ_FOREACH(tp, &tty_list, t_list) {
1329                 tty_lock(tp);
1330                 if (tp->t_session != NULL) {
1331                         p = tp->t_session->s_leader;
1332                         PROC_LOCK(p);
1333                         cansee = (p_cansee(td, p) == 0);
1334                         PROC_UNLOCK(p);
1335                 } else {
1336                         cansee = !jailed(td->td_ucred);
1337                 }
1338                 if (cansee) {
1339                         tty_to_xtty(tp, xt);
1340                         xt++;
1341                 }
1342                 tty_unlock(tp);
1343         }
1344         sx_sunlock(&tty_list_sx);
1345
1346         lsize = (xt - xtlist) * sizeof(struct xtty);
1347         if (lsize > 0) {
1348                 error = SYSCTL_OUT(req, xtlist, lsize);
1349         } else {
1350                 error = 0;
1351         }
1352         free(xtlist, M_TTY);
1353         return (error);
1354 }
1355
1356 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1357         0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1358
1359 /*
1360  * Device node creation. Device has been set up, now we can expose it to
1361  * the user.
1362  */
1363
1364 int
1365 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1366     const char *fmt, ...)
1367 {
1368         va_list ap;
1369         struct make_dev_args args;
1370         struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1371         const char *prefix = "tty";
1372         char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1373         uid_t uid;
1374         gid_t gid;
1375         mode_t mode;
1376         int error;
1377
1378         /* Remove "tty" prefix from devices like PTY's. */
1379         if (tp->t_flags & TF_NOPREFIX)
1380                 prefix = "";
1381
1382         va_start(ap, fmt);
1383         vsnrprintf(name, sizeof name, 32, fmt, ap);
1384         va_end(ap);
1385
1386         if (cred == NULL) {
1387                 /* System device. */
1388                 uid = UID_ROOT;
1389                 gid = GID_WHEEL;
1390                 mode = S_IRUSR|S_IWUSR;
1391         } else {
1392                 /* User device. */
1393                 uid = cred->cr_ruid;
1394                 gid = GID_TTY;
1395                 mode = S_IRUSR|S_IWUSR|S_IWGRP;
1396         }
1397
1398         flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1399         flags |= MAKEDEV_CHECKNAME;
1400
1401         /* Master call-in device. */
1402         make_dev_args_init(&args);
1403         args.mda_flags = flags;
1404         args.mda_devsw = &ttydev_cdevsw;
1405         args.mda_cr = cred;
1406         args.mda_uid = uid;
1407         args.mda_gid = gid;
1408         args.mda_mode = mode;
1409         args.mda_si_drv1 = tp;
1410         error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1411         if (error != 0)
1412                 return (error);
1413         tp->t_dev = dev;
1414
1415         init = lock = cua = cinit = clock = NULL;
1416
1417         /* Slave call-in devices. */
1418         if (tp->t_flags & TF_INITLOCK) {
1419                 args.mda_devsw = &ttyil_cdevsw;
1420                 args.mda_unit = TTYUNIT_INIT;
1421                 args.mda_si_drv1 = tp;
1422                 args.mda_si_drv2 = &tp->t_termios_init_in;
1423                 error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1424                 if (error != 0)
1425                         goto fail;
1426                 dev_depends(dev, init);
1427
1428                 args.mda_unit = TTYUNIT_LOCK;
1429                 args.mda_si_drv2 = &tp->t_termios_lock_in;
1430                 error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1431                 if (error != 0)
1432                         goto fail;
1433                 dev_depends(dev, lock);
1434         }
1435
1436         /* Call-out devices. */
1437         if (tp->t_flags & TF_CALLOUT) {
1438                 make_dev_args_init(&args);
1439                 args.mda_flags = flags;
1440                 args.mda_devsw = &ttydev_cdevsw;
1441                 args.mda_cr = cred;
1442                 args.mda_uid = UID_UUCP;
1443                 args.mda_gid = GID_DIALER;
1444                 args.mda_mode = 0660;
1445                 args.mda_unit = TTYUNIT_CALLOUT;
1446                 args.mda_si_drv1 = tp;
1447                 error = make_dev_s(&args, &cua, "cua%s", name);
1448                 if (error != 0)
1449                         goto fail;
1450                 dev_depends(dev, cua);
1451
1452                 /* Slave call-out devices. */
1453                 if (tp->t_flags & TF_INITLOCK) {
1454                         args.mda_devsw = &ttyil_cdevsw;
1455                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1456                         args.mda_si_drv2 = &tp->t_termios_init_out;
1457                         error = make_dev_s(&args, &cinit, "cua%s.init", name);
1458                         if (error != 0)
1459                                 goto fail;
1460                         dev_depends(dev, cinit);
1461
1462                         args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1463                         args.mda_si_drv2 = &tp->t_termios_lock_out;
1464                         error = make_dev_s(&args, &clock, "cua%s.lock", name);
1465                         if (error != 0)
1466                                 goto fail;
1467                         dev_depends(dev, clock);
1468                 }
1469         }
1470
1471         sx_xlock(&tty_list_sx);
1472         TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1473         tty_list_count++;
1474         sx_xunlock(&tty_list_sx);
1475
1476         return (0);
1477
1478 fail:
1479         destroy_dev(dev);
1480         if (init)
1481                 destroy_dev(init);
1482         if (lock)
1483                 destroy_dev(lock);
1484         if (cinit)
1485                 destroy_dev(cinit);
1486         if (clock)
1487                 destroy_dev(clock);
1488
1489         return (error);
1490 }
1491
1492 /*
1493  * Signalling processes.
1494  */
1495
1496 void
1497 tty_signal_sessleader(struct tty *tp, int sig)
1498 {
1499         struct proc *p;
1500         struct session *s;
1501
1502         tty_assert_locked(tp);
1503         MPASS(sig >= 1 && sig < NSIG);
1504
1505         /* Make signals start output again. */
1506         tp->t_flags &= ~TF_STOPPED;
1507         tp->t_termios.c_lflag &= ~FLUSHO;
1508
1509         /*
1510          * Load s_leader exactly once to avoid race where s_leader is
1511          * set to NULL by a concurrent invocation of killjobc() by the
1512          * session leader.  Note that we are not holding t_session's
1513          * lock for the read.
1514          */
1515         if ((s = tp->t_session) != NULL &&
1516             (p = atomic_load_ptr(&s->s_leader)) != NULL) {
1517                 PROC_LOCK(p);
1518                 kern_psignal(p, sig);
1519                 PROC_UNLOCK(p);
1520         }
1521 }
1522
1523 void
1524 tty_signal_pgrp(struct tty *tp, int sig)
1525 {
1526         ksiginfo_t ksi;
1527
1528         tty_assert_locked(tp);
1529         MPASS(sig >= 1 && sig < NSIG);
1530
1531         /* Make signals start output again. */
1532         tp->t_flags &= ~TF_STOPPED;
1533         tp->t_termios.c_lflag &= ~FLUSHO;
1534
1535         if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1536                 tty_info(tp);
1537         if (tp->t_pgrp != NULL) {
1538                 ksiginfo_init(&ksi);
1539                 ksi.ksi_signo = sig;
1540                 ksi.ksi_code = SI_KERNEL;
1541                 PGRP_LOCK(tp->t_pgrp);
1542                 pgsignal(tp->t_pgrp, sig, 1, &ksi);
1543                 PGRP_UNLOCK(tp->t_pgrp);
1544         }
1545 }
1546
1547 void
1548 tty_wakeup(struct tty *tp, int flags)
1549 {
1550
1551         if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1552                 pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1553
1554         if (flags & FWRITE) {
1555                 cv_broadcast(&tp->t_outwait);
1556                 selwakeup(&tp->t_outpoll);
1557                 KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1558         }
1559         if (flags & FREAD) {
1560                 cv_broadcast(&tp->t_inwait);
1561                 selwakeup(&tp->t_inpoll);
1562                 KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1563         }
1564 }
1565
1566 int
1567 tty_wait(struct tty *tp, struct cv *cv)
1568 {
1569         int error;
1570         int revokecnt = tp->t_revokecnt;
1571
1572         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1573         MPASS(!tty_gone(tp));
1574
1575         error = cv_wait_sig(cv, tp->t_mtx);
1576
1577         /* Bail out when the device slipped away. */
1578         if (tty_gone(tp))
1579                 return (ENXIO);
1580
1581         /* Restart the system call when we may have been revoked. */
1582         if (tp->t_revokecnt != revokecnt)
1583                 return (ERESTART);
1584
1585         return (error);
1586 }
1587
1588 int
1589 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1590 {
1591         int error;
1592         int revokecnt = tp->t_revokecnt;
1593
1594         tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1595         MPASS(!tty_gone(tp));
1596
1597         error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1598
1599         /* Bail out when the device slipped away. */
1600         if (tty_gone(tp))
1601                 return (ENXIO);
1602
1603         /* Restart the system call when we may have been revoked. */
1604         if (tp->t_revokecnt != revokecnt)
1605                 return (ERESTART);
1606
1607         return (error);
1608 }
1609
1610 void
1611 tty_flush(struct tty *tp, int flags)
1612 {
1613
1614         if (flags & FWRITE) {
1615                 tp->t_flags &= ~TF_HIWAT_OUT;
1616                 ttyoutq_flush(&tp->t_outq);
1617                 tty_wakeup(tp, FWRITE);
1618                 if (!tty_gone(tp)) {
1619                         ttydevsw_outwakeup(tp);
1620                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1621                 }
1622         }
1623         if (flags & FREAD) {
1624                 tty_hiwat_in_unblock(tp);
1625                 ttyinq_flush(&tp->t_inq);
1626                 tty_wakeup(tp, FREAD);
1627                 if (!tty_gone(tp)) {
1628                         ttydevsw_inwakeup(tp);
1629                         ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1630                 }
1631         }
1632 }
1633
1634 void
1635 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1636 {
1637
1638         if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1639                 return;
1640         tp->t_winsize = *wsz;
1641         tty_signal_pgrp(tp, SIGWINCH);
1642 }
1643
1644 static int
1645 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1646     struct thread *td)
1647 {
1648         int error;
1649
1650         switch (cmd) {
1651         /*
1652          * Modem commands.
1653          * The SER_* and TIOCM_* flags are the same, but one bit
1654          * shifted. I don't know why.
1655          */
1656         case TIOCSDTR:
1657                 ttydevsw_modem(tp, SER_DTR, 0);
1658                 return (0);
1659         case TIOCCDTR:
1660                 ttydevsw_modem(tp, 0, SER_DTR);
1661                 return (0);
1662         case TIOCMSET: {
1663                 int bits = *(int *)data;
1664                 ttydevsw_modem(tp,
1665                     (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1666                     ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1667                 return (0);
1668         }
1669         case TIOCMBIS: {
1670                 int bits = *(int *)data;
1671                 ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1672                 return (0);
1673         }
1674         case TIOCMBIC: {
1675                 int bits = *(int *)data;
1676                 ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1677                 return (0);
1678         }
1679         case TIOCMGET:
1680                 *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1681                 return (0);
1682
1683         case FIOASYNC:
1684                 if (*(int *)data)
1685                         tp->t_flags |= TF_ASYNC;
1686                 else
1687                         tp->t_flags &= ~TF_ASYNC;
1688                 return (0);
1689         case FIONBIO:
1690                 /* This device supports non-blocking operation. */
1691                 return (0);
1692         case FIONREAD:
1693                 *(int *)data = ttydisc_bytesavail(tp);
1694                 return (0);
1695         case FIONWRITE:
1696         case TIOCOUTQ:
1697                 *(int *)data = ttyoutq_bytesused(&tp->t_outq);
1698                 return (0);
1699         case FIOSETOWN:
1700                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1701                         /* Not allowed to set ownership. */
1702                         return (ENOTTY);
1703
1704                 /* Temporarily unlock the TTY to set ownership. */
1705                 tty_unlock(tp);
1706                 error = fsetown(*(int *)data, &tp->t_sigio);
1707                 tty_lock(tp);
1708                 return (error);
1709         case FIOGETOWN:
1710                 if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1711                         /* Not allowed to set ownership. */
1712                         return (ENOTTY);
1713
1714                 /* Get ownership. */
1715                 *(int *)data = fgetown(&tp->t_sigio);
1716                 return (0);
1717         case TIOCGETA:
1718                 /* Obtain terminal flags through tcgetattr(). */
1719                 *(struct termios*)data = tp->t_termios;
1720                 return (0);
1721         case TIOCSETA:
1722         case TIOCSETAW:
1723         case TIOCSETAF: {
1724                 struct termios *t = data;
1725                 bool canonicalize = false;
1726
1727                 /*
1728                  * Who makes up these funny rules? According to POSIX,
1729                  * input baud rate is set equal to the output baud rate
1730                  * when zero.
1731                  */
1732                 if (t->c_ispeed == 0)
1733                         t->c_ispeed = t->c_ospeed;
1734
1735                 /* Discard any unsupported bits. */
1736                 t->c_iflag &= TTYSUP_IFLAG;
1737                 t->c_oflag &= TTYSUP_OFLAG;
1738                 t->c_lflag &= TTYSUP_LFLAG;
1739                 t->c_cflag &= TTYSUP_CFLAG;
1740
1741                 /* Set terminal flags through tcsetattr(). */
1742                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1743                         error = tty_drain(tp, 0);
1744                         if (error)
1745                                 return (error);
1746                         if (cmd == TIOCSETAF)
1747                                 tty_flush(tp, FREAD);
1748                 }
1749
1750                 /*
1751                  * Only call param() when the flags really change.
1752                  */
1753                 if ((t->c_cflag & CIGNORE) == 0 &&
1754                     (tp->t_termios.c_cflag != t->c_cflag ||
1755                     ((tp->t_termios.c_iflag ^ t->c_iflag) &
1756                     (IXON|IXOFF|IXANY)) ||
1757                     tp->t_termios.c_ispeed != t->c_ispeed ||
1758                     tp->t_termios.c_ospeed != t->c_ospeed)) {
1759                         error = ttydevsw_param(tp, t);
1760                         if (error)
1761                                 return (error);
1762
1763                         /* XXX: CLOCAL? */
1764
1765                         tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1766                         tp->t_termios.c_ispeed = t->c_ispeed;
1767                         tp->t_termios.c_ospeed = t->c_ospeed;
1768
1769                         /* Baud rate has changed - update watermarks. */
1770                         error = tty_watermarks(tp);
1771                         if (error)
1772                                 return (error);
1773                 }
1774
1775                 /*
1776                  * We'll canonicalize any partial input if we're transitioning
1777                  * ICANON one way or the other.  If we're going from -ICANON ->
1778                  * ICANON, then in the worst case scenario we're in the middle
1779                  * of a line but both ttydisc_read() and FIONREAD will search
1780                  * for one of our line terminals.
1781                  */
1782                 if ((t->c_lflag & ICANON) != (tp->t_termios.c_lflag & ICANON))
1783                         canonicalize = true;
1784                 else if (tp->t_termios.c_cc[VEOF] != t->c_cc[VEOF] ||
1785                     tp->t_termios.c_cc[VEOL] != t->c_cc[VEOL])
1786                         canonicalize = true;
1787
1788                 /* Copy new non-device driver parameters. */
1789                 tp->t_termios.c_iflag = t->c_iflag;
1790                 tp->t_termios.c_oflag = t->c_oflag;
1791                 tp->t_termios.c_lflag = t->c_lflag;
1792                 memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1793
1794                 ttydisc_optimize(tp);
1795
1796                 if (canonicalize)
1797                         ttydisc_canonicalize(tp);
1798                 if ((t->c_lflag & ICANON) == 0) {
1799                         /*
1800                          * When in non-canonical mode, wake up all
1801                          * readers. Any partial input has already been
1802                          * canonicalized above if we were in canonical mode.
1803                          * VMIN and VTIME could also be adjusted.
1804                          */
1805                         tty_wakeup(tp, FREAD);
1806                 }
1807
1808                 /*
1809                  * For packet mode: notify the PTY consumer that VSTOP
1810                  * and VSTART may have been changed.
1811                  */
1812                 if (tp->t_termios.c_iflag & IXON &&
1813                     tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1814                     tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1815                         ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1816                 else
1817                         ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1818                 return (0);
1819         }
1820         case TIOCGETD:
1821                 /* For compatibility - we only support TTYDISC. */
1822                 *(int *)data = TTYDISC;
1823                 return (0);
1824         case TIOCGPGRP:
1825                 if (!tty_is_ctty(tp, td->td_proc))
1826                         return (ENOTTY);
1827
1828                 if (tp->t_pgrp != NULL)
1829                         *(int *)data = tp->t_pgrp->pg_id;
1830                 else
1831                         *(int *)data = NO_PID;
1832                 return (0);
1833         case TIOCGSID:
1834                 if (!tty_is_ctty(tp, td->td_proc))
1835                         return (ENOTTY);
1836
1837                 MPASS(tp->t_session);
1838                 *(int *)data = tp->t_session->s_sid;
1839                 return (0);
1840         case TIOCNOTTY:
1841                 return (tty_drop_ctty(tp, td->td_proc));
1842         case TIOCSCTTY: {
1843                 struct proc *p = td->td_proc;
1844
1845                 /* XXX: This looks awful. */
1846                 tty_unlock(tp);
1847                 sx_xlock(&proctree_lock);
1848                 tty_lock(tp);
1849
1850                 if (!SESS_LEADER(p)) {
1851                         /* Only the session leader may do this. */
1852                         sx_xunlock(&proctree_lock);
1853                         return (EPERM);
1854                 }
1855
1856                 if (tp->t_session != NULL && tp->t_session == p->p_session) {
1857                         /* This is already our controlling TTY. */
1858                         sx_xunlock(&proctree_lock);
1859                         return (0);
1860                 }
1861
1862                 if (p->p_session->s_ttyp != NULL ||
1863                     (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1864                     tp->t_session->s_ttyvp->v_type != VBAD)) {
1865                         /*
1866                          * There is already a relation between a TTY and
1867                          * a session, or the caller is not the session
1868                          * leader.
1869                          *
1870                          * Allow the TTY to be stolen when the vnode is
1871                          * invalid, but the reference to the TTY is
1872                          * still active.  This allows immediate reuse of
1873                          * TTYs of which the session leader has been
1874                          * killed or the TTY revoked.
1875                          */
1876                         sx_xunlock(&proctree_lock);
1877                         return (EPERM);
1878                 }
1879
1880                 /* Connect the session to the TTY. */
1881                 tp->t_session = p->p_session;
1882                 tp->t_session->s_ttyp = tp;
1883                 tp->t_sessioncnt++;
1884
1885                 /* Assign foreground process group. */
1886                 tp->t_pgrp = p->p_pgrp;
1887                 PROC_LOCK(p);
1888                 p->p_flag |= P_CONTROLT;
1889                 PROC_UNLOCK(p);
1890
1891                 sx_xunlock(&proctree_lock);
1892                 return (0);
1893         }
1894         case TIOCSPGRP: {
1895                 struct pgrp *pg;
1896
1897                 /*
1898                  * XXX: Temporarily unlock the TTY to locate the process
1899                  * group. This code would be lot nicer if we would ever
1900                  * decompose proctree_lock.
1901                  */
1902                 tty_unlock(tp);
1903                 sx_slock(&proctree_lock);
1904                 pg = pgfind(*(int *)data);
1905                 if (pg != NULL)
1906                         PGRP_UNLOCK(pg);
1907                 if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1908                         sx_sunlock(&proctree_lock);
1909                         tty_lock(tp);
1910                         return (EPERM);
1911                 }
1912                 tty_lock(tp);
1913
1914                 /*
1915                  * Determine if this TTY is the controlling TTY after
1916                  * relocking the TTY.
1917                  */
1918                 if (!tty_is_ctty(tp, td->td_proc)) {
1919                         sx_sunlock(&proctree_lock);
1920                         return (ENOTTY);
1921                 }
1922                 tp->t_pgrp = pg;
1923                 sx_sunlock(&proctree_lock);
1924
1925                 /* Wake up the background process groups. */
1926                 cv_broadcast(&tp->t_bgwait);
1927                 return (0);
1928         }
1929         case TIOCFLUSH: {
1930                 int flags = *(int *)data;
1931
1932                 if (flags == 0)
1933                         flags = (FREAD|FWRITE);
1934                 else
1935                         flags &= (FREAD|FWRITE);
1936                 tty_flush(tp, flags);
1937                 return (0);
1938         }
1939         case TIOCDRAIN:
1940                 /* Drain TTY output. */
1941                 return tty_drain(tp, 0);
1942         case TIOCGDRAINWAIT:
1943                 *(int *)data = tp->t_drainwait;
1944                 return (0);
1945         case TIOCSDRAINWAIT:
1946                 error = priv_check(td, PRIV_TTY_DRAINWAIT);
1947                 if (error == 0)
1948                         tp->t_drainwait = *(int *)data;
1949                 return (error);
1950         case TIOCCONS:
1951                 /* Set terminal as console TTY. */
1952                 if (*(int *)data) {
1953                         error = priv_check(td, PRIV_TTY_CONSOLE);
1954                         if (error)
1955                                 return (error);
1956                         error = constty_set(tp);
1957                 } else {
1958                         error = constty_clear(tp);
1959                 }
1960                 return (error);
1961         case TIOCGWINSZ:
1962                 /* Obtain window size. */
1963                 *(struct winsize*)data = tp->t_winsize;
1964                 return (0);
1965         case TIOCSWINSZ:
1966                 /* Set window size. */
1967                 tty_set_winsize(tp, data);
1968                 return (0);
1969         case TIOCEXCL:
1970                 tp->t_flags |= TF_EXCLUDE;
1971                 return (0);
1972         case TIOCNXCL:
1973                 tp->t_flags &= ~TF_EXCLUDE;
1974                 return (0);
1975         case TIOCSTOP:
1976                 tp->t_flags |= TF_STOPPED;
1977                 ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1978                 return (0);
1979         case TIOCSTART:
1980                 tp->t_flags &= ~TF_STOPPED;
1981                 tp->t_termios.c_lflag &= ~FLUSHO;
1982                 ttydevsw_outwakeup(tp);
1983                 ttydevsw_pktnotify(tp, TIOCPKT_START);
1984                 return (0);
1985         case TIOCSTAT:
1986                 tty_info(tp);
1987                 return (0);
1988         case TIOCSTI:
1989                 if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1990                         return (EPERM);
1991                 if (!tty_is_ctty(tp, td->td_proc) &&
1992                     priv_check(td, PRIV_TTY_STI))
1993                         return (EACCES);
1994                 ttydisc_rint(tp, *(char *)data, 0);
1995                 ttydisc_rint_done(tp);
1996                 return (0);
1997         }
1998
1999 #ifdef COMPAT_43TTY
2000         return tty_ioctl_compat(tp, cmd, data, fflag, td);
2001 #else /* !COMPAT_43TTY */
2002         return (ENOIOCTL);
2003 #endif /* COMPAT_43TTY */
2004 }
2005
2006 int
2007 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
2008 {
2009         int error;
2010
2011         tty_assert_locked(tp);
2012
2013         if (tty_gone(tp))
2014                 return (ENXIO);
2015
2016         error = ttydevsw_ioctl(tp, cmd, data, td);
2017         if (error == ENOIOCTL)
2018                 error = tty_generic_ioctl(tp, cmd, data, fflag, td);
2019
2020         return (error);
2021 }
2022
2023 dev_t
2024 tty_udev(struct tty *tp)
2025 {
2026
2027         if (tp->t_dev)
2028                 return (dev2udev(tp->t_dev));
2029         else
2030                 return (NODEV);
2031 }
2032
2033 int
2034 tty_checkoutq(struct tty *tp)
2035 {
2036
2037         /* 256 bytes should be enough to print a log message. */
2038         return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
2039 }
2040
2041 void
2042 tty_hiwat_in_block(struct tty *tp)
2043 {
2044
2045         if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
2046             tp->t_termios.c_iflag & IXOFF &&
2047             tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
2048                 /*
2049                  * Input flow control. Only enter the high watermark when we
2050                  * can successfully store the VSTOP character.
2051                  */
2052                 if (ttyoutq_write_nofrag(&tp->t_outq,
2053                     &tp->t_termios.c_cc[VSTOP], 1) == 0)
2054                         tp->t_flags |= TF_HIWAT_IN;
2055         } else {
2056                 /* No input flow control. */
2057                 tp->t_flags |= TF_HIWAT_IN;
2058         }
2059 }
2060
2061 void
2062 tty_hiwat_in_unblock(struct tty *tp)
2063 {
2064
2065         if (tp->t_flags & TF_HIWAT_IN &&
2066             tp->t_termios.c_iflag & IXOFF &&
2067             tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
2068                 /*
2069                  * Input flow control. Only leave the high watermark when we
2070                  * can successfully store the VSTART character.
2071                  */
2072                 if (ttyoutq_write_nofrag(&tp->t_outq,
2073                     &tp->t_termios.c_cc[VSTART], 1) == 0)
2074                         tp->t_flags &= ~TF_HIWAT_IN;
2075         } else {
2076                 /* No input flow control. */
2077                 tp->t_flags &= ~TF_HIWAT_IN;
2078         }
2079
2080         if (!tty_gone(tp))
2081                 ttydevsw_inwakeup(tp);
2082 }
2083
2084 /*
2085  * TTY hooks interface.
2086  */
2087
2088 static int
2089 ttyhook_defrint(struct tty *tp, char c, int flags)
2090 {
2091
2092         if (ttyhook_rint_bypass(tp, &c, 1) != 1)
2093                 return (-1);
2094
2095         return (0);
2096 }
2097
2098 int
2099 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
2100     void *softc)
2101 {
2102         struct tty *tp;
2103         struct file *fp;
2104         struct cdev *dev;
2105         struct cdevsw *cdp;
2106         struct filedesc *fdp;
2107         cap_rights_t rights;
2108         int error, ref;
2109
2110         /* Validate the file descriptor. */
2111         /*
2112          * XXX this code inspects a file descriptor from a different process,
2113          * but there is no dedicated routine to do it in fd code, making the
2114          * ordeal highly questionable.
2115          */
2116         fdp = p->p_fd;
2117         FILEDESC_SLOCK(fdp);
2118         error = fget_cap_noref(fdp, fd, cap_rights_init_one(&rights, CAP_TTYHOOK),
2119             &fp, NULL);
2120         if (error == 0 && !fhold(fp))
2121                 error = EBADF;
2122         FILEDESC_SUNLOCK(fdp);
2123         if (error != 0)
2124                 return (error);
2125         if (fp->f_ops == &badfileops) {
2126                 error = EBADF;
2127                 goto done1;
2128         }
2129
2130         /*
2131          * Make sure the vnode is bound to a character device.
2132          * Unlocked check for the vnode type is ok there, because we
2133          * only shall prevent calling devvn_refthread on the file that
2134          * never has been opened over a character device.
2135          */
2136         if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
2137                 error = EINVAL;
2138                 goto done1;
2139         }
2140
2141         /* Make sure it is a TTY. */
2142         cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
2143         if (cdp == NULL) {
2144                 error = ENXIO;
2145                 goto done1;
2146         }
2147         if (dev != fp->f_data) {
2148                 error = ENXIO;
2149                 goto done2;
2150         }
2151         if (cdp != &ttydev_cdevsw) {
2152                 error = ENOTTY;
2153                 goto done2;
2154         }
2155         tp = dev->si_drv1;
2156
2157         /* Try to attach the hook to the TTY. */
2158         error = EBUSY;
2159         tty_lock(tp);
2160         MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
2161         if (tp->t_flags & TF_HOOK)
2162                 goto done3;
2163
2164         tp->t_flags |= TF_HOOK;
2165         tp->t_hook = th;
2166         tp->t_hooksoftc = softc;
2167         *rtp = tp;
2168         error = 0;
2169
2170         /* Maybe we can switch into bypass mode now. */
2171         ttydisc_optimize(tp);
2172
2173         /* Silently convert rint() calls to rint_bypass() when possible. */
2174         if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
2175                 th->th_rint = ttyhook_defrint;
2176
2177 done3:  tty_unlock(tp);
2178 done2:  dev_relthread(dev, ref);
2179 done1:  fdrop(fp, curthread);
2180         return (error);
2181 }
2182
2183 void
2184 ttyhook_unregister(struct tty *tp)
2185 {
2186
2187         tty_assert_locked(tp);
2188         MPASS(tp->t_flags & TF_HOOK);
2189
2190         /* Disconnect the hook. */
2191         tp->t_flags &= ~TF_HOOK;
2192         tp->t_hook = NULL;
2193
2194         /* Maybe we need to leave bypass mode. */
2195         ttydisc_optimize(tp);
2196
2197         /* Maybe deallocate the TTY as well. */
2198         tty_rel_free(tp);
2199 }
2200
2201 /*
2202  * /dev/console handling.
2203  */
2204
2205 static int
2206 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2207 {
2208         struct tty *tp;
2209
2210         /* System has no console device. */
2211         if (dev_console_filename == NULL)
2212                 return (ENXIO);
2213
2214         /* Look up corresponding TTY by device name. */
2215         sx_slock(&tty_list_sx);
2216         TAILQ_FOREACH(tp, &tty_list, t_list) {
2217                 if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2218                         dev_console->si_drv1 = tp;
2219                         break;
2220                 }
2221         }
2222         sx_sunlock(&tty_list_sx);
2223
2224         /* System console has no TTY associated. */
2225         if (dev_console->si_drv1 == NULL)
2226                 return (ENXIO);
2227
2228         return (ttydev_open(dev, oflags, devtype, td));
2229 }
2230
2231 static int
2232 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2233 {
2234
2235         log_console(uio);
2236
2237         return (ttydev_write(dev, uio, ioflag));
2238 }
2239
2240 /*
2241  * /dev/console is a little different than normal TTY's.  When opened,
2242  * it determines which TTY to use.  When data gets written to it, it
2243  * will be logged in the kernel message buffer.
2244  */
2245 static struct cdevsw ttyconsdev_cdevsw = {
2246         .d_version      = D_VERSION,
2247         .d_open         = ttyconsdev_open,
2248         .d_close        = ttydev_close,
2249         .d_read         = ttydev_read,
2250         .d_write        = ttyconsdev_write,
2251         .d_ioctl        = ttydev_ioctl,
2252         .d_kqfilter     = ttydev_kqfilter,
2253         .d_poll         = ttydev_poll,
2254         .d_mmap         = ttydev_mmap,
2255         .d_name         = "ttyconsdev",
2256         .d_flags        = D_TTY,
2257 };
2258
2259 static void
2260 ttyconsdev_init(void *unused __unused)
2261 {
2262
2263         dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2264             NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2265 }
2266
2267 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2268
2269 void
2270 ttyconsdev_select(const char *name)
2271 {
2272
2273         dev_console_filename = name;
2274 }
2275
2276 /*
2277  * Debugging routines.
2278  */
2279
2280 #include "opt_ddb.h"
2281 #ifdef DDB
2282 #include <ddb/ddb.h>
2283 #include <ddb/db_sym.h>
2284
2285 static const struct {
2286         int flag;
2287         char val;
2288 } ttystates[] = {
2289 #if 0
2290         { TF_NOPREFIX,          'N' },
2291 #endif
2292         { TF_INITLOCK,          'I' },
2293         { TF_CALLOUT,           'C' },
2294
2295         /* Keep these together -> 'Oi' and 'Oo'. */
2296         { TF_OPENED,            'O' },
2297         { TF_OPENED_IN,         'i' },
2298         { TF_OPENED_OUT,        'o' },
2299         { TF_OPENED_CONS,       'c' },
2300
2301         { TF_GONE,              'G' },
2302         { TF_OPENCLOSE,         'B' },
2303         { TF_ASYNC,             'Y' },
2304         { TF_LITERAL,           'L' },
2305
2306         /* Keep these together -> 'Hi' and 'Ho'. */
2307         { TF_HIWAT,             'H' },
2308         { TF_HIWAT_IN,          'i' },
2309         { TF_HIWAT_OUT,         'o' },
2310
2311         { TF_STOPPED,           'S' },
2312         { TF_EXCLUDE,           'X' },
2313         { TF_BYPASS,            'l' },
2314         { TF_ZOMBIE,            'Z' },
2315         { TF_HOOK,              's' },
2316
2317         /* Keep these together -> 'bi' and 'bo'. */
2318         { TF_BUSY,              'b' },
2319         { TF_BUSY_IN,           'i' },
2320         { TF_BUSY_OUT,          'o' },
2321
2322         { 0,                    '\0'},
2323 };
2324
2325 #define TTY_FLAG_BITS \
2326         "\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2327         "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2328         "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2329         "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2330         "\21HOOK\22BUSY_IN\23BUSY_OUT"
2331
2332 #define DB_PRINTSYM(name, addr) \
2333         db_printf("%s  " #name ": ", sep); \
2334         db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2335         db_printf("\n");
2336
2337 static void
2338 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2339 {
2340
2341         db_printf("%sdevsw: ", sep);
2342         db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2343         db_printf(" (%p)\n", tsw);
2344         DB_PRINTSYM(open, tsw->tsw_open);
2345         DB_PRINTSYM(close, tsw->tsw_close);
2346         DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2347         DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2348         DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2349         DB_PRINTSYM(param, tsw->tsw_param);
2350         DB_PRINTSYM(modem, tsw->tsw_modem);
2351         DB_PRINTSYM(mmap, tsw->tsw_mmap);
2352         DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2353         DB_PRINTSYM(free, tsw->tsw_free);
2354 }
2355
2356 static void
2357 _db_show_hooks(const char *sep, const struct ttyhook *th)
2358 {
2359
2360         db_printf("%shook: ", sep);
2361         db_printsym((db_addr_t)th, DB_STGY_ANY);
2362         db_printf(" (%p)\n", th);
2363         if (th == NULL)
2364                 return;
2365         DB_PRINTSYM(rint, th->th_rint);
2366         DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2367         DB_PRINTSYM(rint_done, th->th_rint_done);
2368         DB_PRINTSYM(rint_poll, th->th_rint_poll);
2369         DB_PRINTSYM(getc_inject, th->th_getc_inject);
2370         DB_PRINTSYM(getc_capture, th->th_getc_capture);
2371         DB_PRINTSYM(getc_poll, th->th_getc_poll);
2372         DB_PRINTSYM(close, th->th_close);
2373 }
2374
2375 static void
2376 _db_show_termios(const char *name, const struct termios *t)
2377 {
2378
2379         db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2380             "lflag 0x%x ispeed %u ospeed %u\n", name,
2381             t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2382             t->c_ispeed, t->c_ospeed);
2383 }
2384
2385 /* DDB command to show TTY statistics. */
2386 DB_SHOW_COMMAND(tty, db_show_tty)
2387 {
2388         struct tty *tp;
2389
2390         if (!have_addr) {
2391                 db_printf("usage: show tty <addr>\n");
2392                 return;
2393         }
2394         tp = (struct tty *)addr;
2395
2396         db_printf("%p: %s\n", tp, tty_devname(tp));
2397         db_printf("\tmtx: %p\n", tp->t_mtx);
2398         db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2399         db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2400
2401         /* Buffering mechanisms. */
2402         db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2403             "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2404             tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2405             tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2406         db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2407             &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2408             tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2409         db_printf("\tinlow: %zu\n", tp->t_inlow);
2410         db_printf("\toutlow: %zu\n", tp->t_outlow);
2411         _db_show_termios("\ttermios", &tp->t_termios);
2412         db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2413             tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2414             tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2415         db_printf("\tcolumn: %u\n", tp->t_column);
2416         db_printf("\twritepos: %u\n", tp->t_writepos);
2417         db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2418
2419         /* Init/lock-state devices. */
2420         _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2421         _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2422         _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2423         _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2424
2425         /* Hooks */
2426         _db_show_devsw("\t", tp->t_devsw);
2427         _db_show_hooks("\t", tp->t_hook);
2428
2429         /* Process info. */
2430         db_printf("\tpgrp: %p gid %d\n", tp->t_pgrp,
2431             tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2432         db_printf("\tsession: %p", tp->t_session);
2433         if (tp->t_session != NULL)
2434             db_printf(" count %u leader %p tty %p sid %d login %s",
2435                 tp->t_session->s_count, tp->t_session->s_leader,
2436                 tp->t_session->s_ttyp, tp->t_session->s_sid,
2437                 tp->t_session->s_login);
2438         db_printf("\n");
2439         db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2440         db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2441         db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2442         db_printf("\tdev: %p\n", tp->t_dev);
2443 }
2444
2445 /* DDB command to list TTYs. */
2446 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2447 {
2448         struct tty *tp;
2449         size_t isiz, osiz;
2450         int i, j;
2451
2452         /* Make the output look like `pstat -t'. */
2453         db_printf("PTR        ");
2454 #if defined(__LP64__)
2455         db_printf("        ");
2456 #endif
2457         db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2458             "COL  SESS  PGID STATE\n");
2459
2460         TAILQ_FOREACH(tp, &tty_list, t_list) {
2461                 isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2462                 osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2463
2464                 db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2465                     "%5d ", tp, tty_devname(tp), isiz,
2466                     tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2467                     tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2468                     isiz - tp->t_inlow, osiz,
2469                     tp->t_outq.to_end - tp->t_outq.to_begin,
2470                     osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2471                     tp->t_session ? tp->t_session->s_sid : 0,
2472                     tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2473
2474                 /* Flag bits. */
2475                 for (i = j = 0; ttystates[i].flag; i++)
2476                         if (tp->t_flags & ttystates[i].flag) {
2477                                 db_printf("%c", ttystates[i].val);
2478                                 j++;
2479                         }
2480                 if (j == 0)
2481                         db_printf("-");
2482                 db_printf("\n");
2483         }
2484 }
2485 #endif /* DDB */