sys/kern/tty.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1990, 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * (c) UNIX System Laboratories, Inc.
   5  * All or some portions of this file are derived from material licensed
   6  * to the University of California by American Telephone and Telegraph
   7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   8  * the permission of UNIX System Laboratories, Inc.
   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  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  *      @(#)tty.c       8.8 (Berkeley) 1/21/94
  39  * $FreeBSD: src/sys/kern/tty.c,v 1.129.2.5 2002/03/11 01:32:31 dd Exp $
  40  * $DragonFly: src/sys/kern/tty.c,v 1.46 2008/09/10 09:50:09 y0netan1 Exp $
  41  */
  42
  43 /*-
  44  * TODO:
  45  *      o Fix races for sending the start char in ttyflush().
  46  *      o Handle inter-byte timeout for "MIN > 0, TIME > 0" in ttyselect().
  47  *        With luck, there will be MIN chars before select() returns().
  48  *      o Handle CLOCAL consistently for ptys.  Perhaps disallow setting it.
  49  *      o Don't allow input in TS_ZOMBIE case.  It would be visible through
  50  *        FIONREAD.
  51  *      o Do the new sio locking stuff here and use it to avoid special
  52  *        case for EXTPROC?
  53  *      o Lock PENDIN too?
  54  *      o Move EXTPROC and/or PENDIN to t_state?
  55  *      o Wrap most of ttioctl in spltty/splx.
  56  *      o Implement TIOCNOTTY or remove it from <sys/ioctl.h>.
  57  *      o Send STOP if IXOFF is toggled off while TS_TBLOCK is set.
  58  *      o Don't allow certain termios flags to affect disciplines other
  59  *        than TTYDISC.  Cancel their effects before switch disciplines
  60  *        and ignore them if they are set while we are in another
  61  *        discipline.
  62  *      o Now that historical speed conversions are handled here, don't
  63  *        do them in drivers.
  64  *      o Check for TS_CARR_ON being set while everything is closed and not
  65  *        waiting for carrier.  TS_CARR_ON isn't cleared if nothing is open,
  66  *        so it would live until the next open even if carrier drops.
  67  *      o Restore TS_WOPEN since it is useful in pstat.  It must be cleared
  68  *        only when _all_ openers leave open().
  69  */
  70
  71 #include "opt_compat.h"
  72 #include "opt_uconsole.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/systm.h>
  76 #include <sys/filio.h>
  77 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  78 #include <sys/ioctl_compat.h>
  79 #endif
  80 #include <sys/proc.h>
  81 #include <sys/priv.h>
  82 #define TTYDEFCHARS
  83 #include <sys/tty.h>
  84 #include <sys/clist.h>
  85 #undef  TTYDEFCHARS
  86 #include <sys/fcntl.h>
  87 #include <sys/conf.h>
  88 #include <sys/dkstat.h>
  89 #include <sys/kernel.h>
  90 #include <sys/vnode.h>
  91 #include <sys/signalvar.h>
  92 #include <sys/signal2.h>
  93 #include <sys/resourcevar.h>
  94 #include <sys/malloc.h>
  95 #include <sys/filedesc.h>
  96 #include <sys/sysctl.h>
  97 #include <sys/thread2.h>
  98
  99 #include <vm/vm.h>
 100 #include <sys/lock.h>
 101 #include <vm/pmap.h>
 102 #include <vm/vm_map.h>
 103
 104 MALLOC_DEFINE(M_TTYS, "ttys", "tty data structures");
 105
 106 static int      proc_compare (struct proc *p1, struct proc *p2);
 107 static int      ttnread (struct tty *tp);
 108 static void     ttyecho (int c, struct tty *tp);
 109 static int      ttyoutput (int c, struct tty *tp);
 110 static void     ttypend (struct tty *tp);
 111 static void     ttyretype (struct tty *tp);
 112 static void     ttyrub (int c, struct tty *tp);
 113 static void     ttyrubo (struct tty *tp, int cnt);
 114 static void     ttyunblock (struct tty *tp);
 115 static int      ttywflush (struct tty *tp);
 116 static int      filt_ttyread (struct knote *kn, long hint);
 117 static void     filt_ttyrdetach (struct knote *kn);
 118 static int      filt_ttywrite (struct knote *kn, long hint);
 119 static void     filt_ttywdetach (struct knote *kn);
 120
 121 /*
 122  * Table with character classes and parity. The 8th bit indicates parity,
 123  * the 7th bit indicates the character is an alphameric or underscore (for
 124  * ALTWERASE), and the low 6 bits indicate delay type.  If the low 6 bits
 125  * are 0 then the character needs no special processing on output; classes
 126  * other than 0 might be translated or (not currently) require delays.
 127  */
 128 #define E       0x00    /* Even parity. */
 129 #define O       0x80    /* Odd parity. */
 130 #define PARITY(c)       (char_type[c] & O)
 131
 132 #define ALPHA   0x40    /* Alpha or underscore. */
 133 #define ISALPHA(c)      (char_type[(c) & TTY_CHARMASK] & ALPHA)
 134
 135 #define CCLASSMASK      0x3f
 136 #define CCLASS(c)       (char_type[c] & CCLASSMASK)
 137
 138 #define BS      BACKSPACE
 139 #define CC      CONTROL
 140 #define CR      RETURN
 141 #define NA      ORDINARY | ALPHA
 142 #define NL      NEWLINE
 143 #define NO      ORDINARY
 144 #define TB      TAB
 145 #define VT      VTAB
 146
 147 static u_char const char_type[] = {
 148         E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* nul - bel */
 149         O|BS, E|TB, E|NL, O|CC, E|VT, O|CR, O|CC, E|CC, /* bs - si */
 150         O|CC, E|CC, E|CC, O|CC, E|CC, O|CC, O|CC, E|CC, /* dle - etb */
 151         E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* can - us */
 152         O|NO, E|NO, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* sp - ' */
 153         E|NO, O|NO, O|NO, E|NO, O|NO, E|NO, E|NO, O|NO, /* ( - / */
 154         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* 0 - 7 */
 155         O|NA, E|NA, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* 8 - ? */
 156         O|NO, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* @ - G */
 157         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* H - O */
 158         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* P - W */
 159         O|NA, E|NA, E|NA, O|NO, E|NO, O|NO, O|NO, O|NA, /* X - _ */
 160         E|NO, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* ` - g */
 161         O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* h - o */
 162         O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* p - w */
 163         E|NA, O|NA, O|NA, E|NO, O|NO, E|NO, E|NO, O|CC, /* x - del */
 164         /*
 165          * Meta chars; should be settable per character set;
 166          * for now, treat them all as normal characters.
 167          */
 168         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 169         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 170         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 171         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 172         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 173         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 174         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 175         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 176         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 177         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 178         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 179         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 180         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 181         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 182         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 183         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 184 };
 185 #undef  BS
 186 #undef  CC
 187 #undef  CR
 188 #undef  NA
 189 #undef  NL
 190 #undef  NO
 191 #undef  TB
 192 #undef  VT
 193
 194 /* Macros to clear/set/test flags. */
 195 #define SET(t, f)       (t) |= (f)
 196 #define CLR(t, f)       (t) &= ~(f)
 197 #define ISSET(t, f)     ((t) & (f))
 198
 199 #undef MAX_INPUT                /* XXX wrong in <sys/syslimits.h> */
 200 #define MAX_INPUT       TTYHOG  /* XXX limit is usually larger for !ICANON */
 201
 202 uint64_t tk_nin;
 203 SYSCTL_OPAQUE(_kern, OID_AUTO, tk_nin, CTLFLAG_RD, &tk_nin, sizeof(tk_nin),
 204     "LU", "TTY input statistic");
 205 uint64_t tk_nout;
 206 SYSCTL_OPAQUE(_kern, OID_AUTO, tk_nout, CTLFLAG_RD, &tk_nout, sizeof(tk_nout),
 207     "LU", "TTY output statistic");
 208 uint64_t tk_rawcc;
 209
 210 /*
 211  * list of struct tty where pstat(8) can pick it up with sysctl
 212  */
 213 static SLIST_HEAD(, tty) tty_list;
 214
 215 /*
 216  * Initial open of tty, or (re)entry to standard tty line discipline.
 217  */
 218 int
 219 ttyopen(cdev_t device, struct tty *tp)
 220 {
 221         crit_enter();
 222         tp->t_dev = device;
 223         if (!ISSET(tp->t_state, TS_ISOPEN)) {
 224                 SET(tp->t_state, TS_ISOPEN);
 225                 if (ISSET(tp->t_cflag, CLOCAL)) {
 226                         SET(tp->t_state, TS_CONNECTED);
 227                 }
 228                 bzero(&tp->t_winsize, sizeof(tp->t_winsize));
 229         }
 230         ttsetwater(tp);
 231         crit_exit();
 232         return (0);
 233 }
 234
 235 /*
 236  * Handle close() on a tty line: flush and set to initial state,
 237  * bumping generation number so that pending read/write calls
 238  * can detect recycling of the tty.
 239  *
 240  * XXX our caller should have done `spltty(); l_close(); ttyclose();'
 241  * and l_close() should have flushed, but we repeat the spltty() and
 242  * the flush in case there are buggy callers.
 243  */
 244 int
 245 ttyclose(struct tty *tp)
 246 {
 247         funsetown(tp->t_sigio);
 248         crit_enter();
 249         if (constty == tp)
 250                 constty = NULL;
 251
 252         ttyflush(tp, FREAD | FWRITE);
 253         clist_free_cblocks(&tp->t_canq);
 254         clist_free_cblocks(&tp->t_outq);
 255         clist_free_cblocks(&tp->t_rawq);
 256
 257         tp->t_gen++;
 258         tp->t_line = TTYDISC;
 259         ttyclearsession(tp);
 260         tp->t_state = 0;
 261         crit_exit();
 262         return (0);
 263 }
 264
 265 /*
 266  * Disassociate the tty from its session.  Traditionally this has only been
 267  * a half-close, meaning that the session was still allowed to point at the
 268  * tty (resulting in the tty in the ps command showing something like 'p0-'),
 269  * even though the tty is no longer pointing at the session.
 270  *
 271  * The half close seems to be useful only for 'ps' output but there is as
 272  * yet no reason to remove the feature.  The full-close code is currently
 273  * #if 0'd out.  See also sess_rele() in kern/kern_proc.c.
 274  */
 275 void
 276 ttyclearsession(struct tty *tp)
 277 {
 278         struct session *sp;
 279
 280         tp->t_pgrp = NULL;
 281         if ((sp = tp->t_session) != NULL) {
 282                 tp->t_session = NULL;
 283 #ifdef TTY_DO_FULL_CLOSE
 284                 /* FULL CLOSE (not yet) */
 285                 if (sp->s_ttyp == tp) {
 286                         sp->s_ttyp = NULL;
 287                 } else {
 288                         kprintf("ttyclearsession: warning: sp->s_ttyp != tp "
 289                                 "%p/%p\n", sp->s_ttyp, tp);
 290                 }
 291 #endif
 292         }
 293 }
 294
 295 /*
 296  * Release the tty vnode association for a session.  This is the
 297  * 'other half' of the close.  Because multiple opens of /dev/tty
 298  * only generate a single open to the actual tty, the file modes
 299  * are locked to FREAD|FWRITE.
 300  *
 301  * If dorevoke is non-zero, the session is also revoked.  We have to
 302  * close the vnode if VCTTYISOPEN is set.
 303  */
 304 void
 305 ttyclosesession(struct session *sp, int dorevoke)
 306 {
 307         struct vnode *vp;
 308
 309 retry:
 310         /*
 311          * There may not be a controlling terminal or it may have been closed
 312          * out from under us.
 313          */
 314         if ((vp = sp->s_ttyvp) == NULL)
 315                 return;
 316
 317         /*
 318          * We need a lock if we have to close or revoke.
 319          */
 320         if ((vp->v_flag & VCTTYISOPEN) || dorevoke) {
 321                 vhold(vp);
 322                 if (vn_lock(vp, LK_EXCLUSIVE|LK_RETRY)) {
 323                         vdrop(vp);
 324                         goto retry;
 325                 }
 326
 327                 /*
 328                  * Retry if the vnode was ripped out from under us
 329                  */
 330                 if (vp != sp->s_ttyvp) {
 331                         vn_unlock(vp);
 332                         vdrop(vp);
 333                         goto retry;
 334                 }
 335
 336                 /*
 337                  * Close and revoke as needed
 338                  */
 339                 sp->s_ttyvp = NULL;
 340                 if (vp->v_flag & VCTTYISOPEN) {
 341                         vclrflags(vp, VCTTYISOPEN);
 342                         VOP_CLOSE(vp, FREAD|FWRITE);
 343                 }
 344                 vn_unlock(vp);
 345                 if (dorevoke)
 346                         vrevoke(vp, proc0.p_ucred);
 347                 vdrop(vp);
 348         } else {
 349                 sp->s_ttyvp = NULL;
 350         }
 351         vrele(vp);
 352 }
 353
 354 #define FLUSHQ(q) {                                                     \
 355         if ((q)->c_cc)                                                  \
 356                 ndflush(q, (q)->c_cc);                                  \
 357 }
 358
 359 /* Is 'c' a line delimiter ("break" character)? */
 360 #define TTBREAKC(c, lflag)                                                      \
 361         ((c) == '\n' || (((c) == cc[VEOF] ||                            \
 362           (c) == cc[VEOL] || ((c) == cc[VEOL2] && lflag & IEXTEN)) &&   \
 363          (c) != _POSIX_VDISABLE))
 364
 365 /*
 366  * Process input of a single character received on a tty.
 367  */
 368 int
 369 ttyinput(int c, struct tty *tp)
 370 {
 371         tcflag_t iflag, lflag;
 372         cc_t *cc;
 373         int i, err;
 374
 375         /*
 376          * If input is pending take it first.
 377          */
 378         lflag = tp->t_lflag;
 379         if (ISSET(lflag, PENDIN))
 380                 ttypend(tp);
 381         /*
 382          * Gather stats.
 383          */
 384         if (ISSET(lflag, ICANON))
 385                 ++tp->t_cancc;
 386         else
 387                 ++tp->t_rawcc;
 388         ++tk_nin;
 389
 390         /*
 391          * Block further input iff:
 392          * current input > threshold AND input is available to user program
 393          * AND input flow control is enabled and not yet invoked.
 394          * The 3 is slop for PARMRK.
 395          */
 396         iflag = tp->t_iflag;
 397         if (tp->t_rawq.c_cc + tp->t_canq.c_cc > tp->t_ihiwat - 3 &&
 398             (!ISSET(lflag, ICANON) || tp->t_canq.c_cc != 0) &&
 399             (ISSET(tp->t_cflag, CRTS_IFLOW) || ISSET(iflag, IXOFF)) &&
 400             !ISSET(tp->t_state, TS_TBLOCK))
 401                 ttyblock(tp);
 402
 403         /* Handle exceptional conditions (break, parity, framing). */
 404         cc = tp->t_cc;
 405         err = (ISSET(c, TTY_ERRORMASK));
 406         if (err) {
 407                 CLR(c, TTY_ERRORMASK);
 408                 if (ISSET(err, TTY_BI)) {
 409                         if (ISSET(iflag, IGNBRK))
 410                                 return (0);
 411                         if (ISSET(iflag, BRKINT)) {
 412                                 ttyflush(tp, FREAD | FWRITE);
 413                                 pgsignal(tp->t_pgrp, SIGINT, 1);
 414                                 goto endcase;
 415                         }
 416                         if (ISSET(iflag, PARMRK))
 417                                 goto parmrk;
 418                 } else if ((ISSET(err, TTY_PE) && ISSET(iflag, INPCK))
 419                         || ISSET(err, TTY_FE)) {
 420                         if (ISSET(iflag, IGNPAR))
 421                                 return (0);
 422                         else if (ISSET(iflag, PARMRK)) {
 423 parmrk:
 424                                 if (tp->t_rawq.c_cc + tp->t_canq.c_cc >
 425                                     MAX_INPUT - 3)
 426                                         goto input_overflow;
 427                                 clist_putc(0377 | TTY_QUOTE, &tp->t_rawq);
 428                                 clist_putc(0 | TTY_QUOTE, &tp->t_rawq);
 429                                 clist_putc(c | TTY_QUOTE, &tp->t_rawq);
 430                                 goto endcase;
 431                         } else
 432                                 c = 0;
 433                 }
 434         }
 435
 436         if (!ISSET(tp->t_state, TS_TYPEN) && ISSET(iflag, ISTRIP))
 437                 CLR(c, 0x80);
 438         if (!ISSET(lflag, EXTPROC)) {
 439                 /*
 440                  * Check for literal nexting very first
 441                  */
 442                 if (ISSET(tp->t_state, TS_LNCH)) {
 443                         SET(c, TTY_QUOTE);
 444                         CLR(tp->t_state, TS_LNCH);
 445                 }
 446                 /*
 447                  * Scan for special characters.  This code
 448                  * is really just a big case statement with
 449                  * non-constant cases.  The bottom of the
 450                  * case statement is labeled ``endcase'', so goto
 451                  * it after a case match, or similar.
 452                  */
 453
 454                 /*
 455                  * Control chars which aren't controlled
 456                  * by ICANON, ISIG, or IXON.
 457                  */
 458                 if (ISSET(lflag, IEXTEN)) {
 459                         if (CCEQ(cc[VLNEXT], c)) {
 460                                 if (ISSET(lflag, ECHO)) {
 461                                         if (ISSET(lflag, ECHOE)) {
 462                                                 (void)ttyoutput('^', tp);
 463                                                 (void)ttyoutput('\b', tp);
 464                                         } else
 465                                                 ttyecho(c, tp);
 466                                 }
 467                                 SET(tp->t_state, TS_LNCH);
 468                                 goto endcase;
 469                         }
 470                         if (CCEQ(cc[VDISCARD], c)) {
 471                                 if (ISSET(lflag, FLUSHO))
 472                                         CLR(tp->t_lflag, FLUSHO);
 473                                 else {
 474                                         ttyflush(tp, FWRITE);
 475                                         ttyecho(c, tp);
 476                                         if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
 477                                                 ttyretype(tp);
 478                                         SET(tp->t_lflag, FLUSHO);
 479                                 }
 480                                 goto startoutput;
 481                         }
 482                 }
 483                 /*
 484                  * Signals.
 485                  */
 486                 if (ISSET(lflag, ISIG)) {
 487                         if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
 488                                 if (!ISSET(lflag, NOFLSH))
 489                                         ttyflush(tp, FREAD | FWRITE);
 490                                 ttyecho(c, tp);
 491                                 pgsignal(tp->t_pgrp,
 492                                     CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
 493                                 goto endcase;
 494                         }
 495                         if (CCEQ(cc[VSUSP], c)) {
 496                                 if (!ISSET(lflag, NOFLSH))
 497                                         ttyflush(tp, FREAD);
 498                                 ttyecho(c, tp);
 499                                 pgsignal(tp->t_pgrp, SIGTSTP, 1);
 500                                 goto endcase;
 501                         }
 502                 }
 503                 /*
 504                  * Handle start/stop characters.
 505                  */
 506                 if (ISSET(iflag, IXON)) {
 507                         if (CCEQ(cc[VSTOP], c)) {
 508                                 if (!ISSET(tp->t_state, TS_TTSTOP)) {
 509                                         SET(tp->t_state, TS_TTSTOP);
 510                                         (*tp->t_stop)(tp, 0);
 511                                         return (0);
 512                                 }
 513                                 if (!CCEQ(cc[VSTART], c))
 514                                         return (0);
 515                                 /*
 516                                  * if VSTART == VSTOP then toggle
 517                                  */
 518                                 goto endcase;
 519                         }
 520                         if (CCEQ(cc[VSTART], c))
 521                                 goto restartoutput;
 522                 }
 523                 /*
 524                  * IGNCR, ICRNL, & INLCR
 525                  */
 526                 if (c == '\r') {
 527                         if (ISSET(iflag, IGNCR))
 528                                 return (0);
 529                         else if (ISSET(iflag, ICRNL))
 530                                 c = '\n';
 531                 } else if (c == '\n' && ISSET(iflag, INLCR))
 532                         c = '\r';
 533         }
 534         if (!ISSET(tp->t_lflag, EXTPROC) && ISSET(lflag, ICANON)) {
 535                 /*
 536                  * From here on down canonical mode character
 537                  * processing takes place.
 538                  */
 539                 /*
 540                  * erase or erase2 (^H / ^?)
 541                  */
 542                 if (CCEQ(cc[VERASE], c) || CCEQ(cc[VERASE2], c) ) {
 543                         if (tp->t_rawq.c_cc)
 544                                 ttyrub(clist_unputc(&tp->t_rawq), tp);
 545                         goto endcase;
 546                 }
 547                 /*
 548                  * kill (^U)
 549                  */
 550                 if (CCEQ(cc[VKILL], c)) {
 551                         if (ISSET(lflag, ECHOKE) &&
 552                             tp->t_rawq.c_cc == tp->t_rocount &&
 553                             !ISSET(lflag, ECHOPRT))
 554                                 while (tp->t_rawq.c_cc)
 555                                         ttyrub(clist_unputc(&tp->t_rawq), tp);
 556                         else {
 557                                 ttyecho(c, tp);
 558                                 if (ISSET(lflag, ECHOK) ||
 559                                     ISSET(lflag, ECHOKE))
 560                                         ttyecho('\n', tp);
 561                                 FLUSHQ(&tp->t_rawq);
 562                                 tp->t_rocount = 0;
 563                         }
 564                         CLR(tp->t_state, TS_LOCAL);
 565                         goto endcase;
 566                 }
 567                 /*
 568                  * word erase (^W)
 569                  */
 570                 if (CCEQ(cc[VWERASE], c) && ISSET(lflag, IEXTEN)) {
 571                         int ctype;
 572
 573                         /*
 574                          * erase whitespace
 575                          */
 576                         while ((c = clist_unputc(&tp->t_rawq)) == ' ' || c == '\t')
 577                                 ttyrub(c, tp);
 578                         if (c == -1)
 579                                 goto endcase;
 580                         /*
 581                          * erase last char of word and remember the
 582                          * next chars type (for ALTWERASE)
 583                          */
 584                         ttyrub(c, tp);
 585                         c = clist_unputc(&tp->t_rawq);
 586                         if (c == -1)
 587                                 goto endcase;
 588                         if (c == ' ' || c == '\t') {
 589                                 clist_putc(c, &tp->t_rawq);
 590                                 goto endcase;
 591                         }
 592                         ctype = ISALPHA(c);
 593                         /*
 594                          * erase rest of word
 595                          */
 596                         do {
 597                                 ttyrub(c, tp);
 598                                 c = clist_unputc(&tp->t_rawq);
 599                                 if (c == -1)
 600                                         goto endcase;
 601                         } while (c != ' ' && c != '\t' &&
 602                             (!ISSET(lflag, ALTWERASE) || ISALPHA(c) == ctype));
 603                         clist_putc(c, &tp->t_rawq);
 604                         goto endcase;
 605                 }
 606                 /*
 607                  * reprint line (^R)
 608                  */
 609                 if (CCEQ(cc[VREPRINT], c) && ISSET(lflag, IEXTEN)) {
 610                         ttyretype(tp);
 611                         goto endcase;
 612                 }
 613                 /*
 614                  * ^T - kernel info and generate SIGINFO
 615                  */
 616                 if (CCEQ(cc[VSTATUS], c) && ISSET(lflag, IEXTEN)) {
 617                         if (ISSET(lflag, ISIG))
 618                                 pgsignal(tp->t_pgrp, SIGINFO, 1);
 619                         if (!ISSET(lflag, NOKERNINFO))
 620                                 ttyinfo(tp);
 621                         goto endcase;
 622                 }
 623                 if (CCEQ(cc[VCHECKPT], c) && ISSET(lflag, IEXTEN)) {
 624                         if (ISSET(lflag, ISIG))
 625                                 pgsignal(tp->t_pgrp, SIGCKPT, 1);
 626                         goto endcase;
 627                 }
 628         }
 629         /*
 630          * Check for input buffer overflow
 631          */
 632         if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= MAX_INPUT) {
 633 input_overflow:
 634                 if (ISSET(iflag, IMAXBEL)) {
 635                         if (tp->t_outq.c_cc < tp->t_ohiwat)
 636                                 (void)ttyoutput(CTRL('g'), tp);
 637                 }
 638                 goto endcase;
 639         }
 640
 641         if (   c == 0377 && ISSET(iflag, PARMRK) && !ISSET(iflag, ISTRIP)
 642              && ISSET(iflag, IGNBRK|IGNPAR) != (IGNBRK|IGNPAR))
 643                 clist_putc(0377 | TTY_QUOTE, &tp->t_rawq);
 644
 645         /*
 646          * Put data char in q for user and
 647          * wakeup on seeing a line delimiter.
 648          */
 649         if (clist_putc(c, &tp->t_rawq) >= 0) {
 650                 if (!ISSET(lflag, ICANON)) {
 651                         ttwakeup(tp);
 652                         ttyecho(c, tp);
 653                         goto endcase;
 654                 }
 655                 if (TTBREAKC(c, lflag)) {
 656                         tp->t_rocount = 0;
 657                         catq(&tp->t_rawq, &tp->t_canq);
 658                         ttwakeup(tp);
 659                 } else if (tp->t_rocount++ == 0)
 660                         tp->t_rocol = tp->t_column;
 661                 if (ISSET(tp->t_state, TS_ERASE)) {
 662                         /*
 663                          * end of prterase \.../
 664                          */
 665                         CLR(tp->t_state, TS_ERASE);
 666                         (void)ttyoutput('/', tp);
 667                 }
 668                 i = tp->t_column;
 669                 ttyecho(c, tp);
 670                 if (CCEQ(cc[VEOF], c) && ISSET(lflag, ECHO)) {
 671                         /*
 672                          * Place the cursor over the '^' of the ^D.
 673                          */
 674                         i = imin(2, tp->t_column - i);
 675                         while (i > 0) {
 676                                 (void)ttyoutput('\b', tp);
 677                                 i--;
 678                         }
 679                 }
 680         }
 681 endcase:
 682         /*
 683          * IXANY means allow any character to restart output.
 684          */
 685         if (ISSET(tp->t_state, TS_TTSTOP) &&
 686             !ISSET(iflag, IXANY) && cc[VSTART] != cc[VSTOP])
 687                 return (0);
 688 restartoutput:
 689         CLR(tp->t_lflag, FLUSHO);
 690         CLR(tp->t_state, TS_TTSTOP);
 691 startoutput:
 692         return (ttstart(tp));
 693 }
 694
 695 /*
 696  * Output a single character on a tty, doing output processing
 697  * as needed (expanding tabs, newline processing, etc.).
 698  * Returns < 0 if succeeds, otherwise returns char to resend.
 699  * Must be recursive.
 700  */
 701 static int
 702 ttyoutput(int c, struct tty *tp)
 703 {
 704         tcflag_t oflag;
 705         int col;
 706
 707         oflag = tp->t_oflag;
 708         if (!ISSET(oflag, OPOST)) {
 709                 if (ISSET(tp->t_lflag, FLUSHO))
 710                         return (-1);
 711                 if (clist_putc(c, &tp->t_outq))
 712                         return (c);
 713                 tk_nout++;
 714                 tp->t_outcc++;
 715                 return (-1);
 716         }
 717         /*
 718          * Do tab expansion if OXTABS is set.  Special case if we external
 719          * processing, we don't do the tab expansion because we'll probably
 720          * get it wrong.  If tab expansion needs to be done, let it happen
 721          * externally.
 722          */
 723         CLR(c, ~TTY_CHARMASK);
 724         if (c == '\t' &&
 725             ISSET(oflag, OXTABS) && !ISSET(tp->t_lflag, EXTPROC)) {
 726                 c = 8 - (tp->t_column & 7);
 727                 if (!ISSET(tp->t_lflag, FLUSHO)) {
 728                         crit_enter();           /* Don't interrupt tabs. */
 729                         c -= b_to_q("        ", c, &tp->t_outq);
 730                         tk_nout += c;
 731                         tp->t_outcc += c;
 732                         crit_exit();
 733                 }
 734                 tp->t_column += c;
 735                 return (c ? -1 : '\t');
 736         }
 737         if (c == CEOT && ISSET(oflag, ONOEOT))
 738                 return (-1);
 739
 740         /*
 741          * Newline translation: if ONLCR is set,
 742          * translate newline into "\r\n".
 743          */
 744         if (c == '\n' && ISSET(tp->t_oflag, ONLCR)) {
 745                 tk_nout++;
 746                 tp->t_outcc++;
 747                 if (!ISSET(tp->t_lflag, FLUSHO) && clist_putc('\r', &tp->t_outq))
 748                         return (c);
 749         }
 750         /* If OCRNL is set, translate "\r" into "\n". */
 751         else if (c == '\r' && ISSET(tp->t_oflag, OCRNL))
 752                 c = '\n';
 753         /* If ONOCR is set, don't transmit CRs when on column 0. */
 754         else if (c == '\r' && ISSET(tp->t_oflag, ONOCR) && tp->t_column == 0)
 755                 return (-1);
 756
 757         tk_nout++;
 758         tp->t_outcc++;
 759         if (!ISSET(tp->t_lflag, FLUSHO) && clist_putc(c, &tp->t_outq))
 760                 return (c);
 761
 762         col = tp->t_column;
 763         switch (CCLASS(c)) {
 764         case BACKSPACE:
 765                 if (col > 0)
 766                         --col;
 767                 break;
 768         case CONTROL:
 769                 break;
 770         case NEWLINE:
 771                 if (ISSET(tp->t_oflag, ONLCR | ONLRET))
 772                         col = 0;
 773                 break;
 774         case RETURN:
 775                 col = 0;
 776                 break;
 777         case ORDINARY:
 778                 ++col;
 779                 break;
 780         case TAB:
 781                 col = (col + 8) & ~7;
 782                 break;
 783         }
 784         tp->t_column = col;
 785         return (-1);
 786 }
 787
 788 /*
 789  * Ioctls for all tty devices.  Called after line-discipline specific ioctl
 790  * has been called to do discipline-specific functions and/or reject any
 791  * of these ioctl commands.
 792  */
 793 /* ARGSUSED */
 794 int
 795 ttioctl(struct tty *tp, u_long cmd, void *data, int flag)
 796 {
 797         struct thread *td = curthread;
 798         struct lwp *lp = td->td_lwp;
 799         struct proc *p = td->td_proc;
 800         int error;
 801
 802         KKASSERT(p);
 803
 804         /* If the ioctl involves modification, hang if in the background. */
 805         switch (cmd) {
 806         case  TIOCCBRK:
 807         case  TIOCCONS:
 808         case  TIOCDRAIN:
 809         case  TIOCEXCL:
 810         case  TIOCFLUSH:
 811 #ifdef TIOCHPCL
 812         case  TIOCHPCL:
 813 #endif
 814         case  TIOCNXCL:
 815         case  TIOCSBRK:
 816         case  TIOCSCTTY:
 817         case  TIOCSDRAINWAIT:
 818         case  TIOCSETA:
 819         case  TIOCSETAF:
 820         case  TIOCSETAW:
 821         case  TIOCSETD:
 822         case  TIOCSPGRP:
 823         case  TIOCSTART:
 824         case  TIOCSTAT:
 825         case  TIOCSTI:
 826         case  TIOCSTOP:
 827         case  TIOCSWINSZ:
 828 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
 829         case  TIOCLBIC:
 830         case  TIOCLBIS:
 831         case  TIOCLSET:
 832         case  TIOCSETC:
 833         case OTIOCSETD:
 834         case  TIOCSETN:
 835         case  TIOCSETP:
 836         case  TIOCSLTC:
 837 #endif
 838                 while (isbackground(p, tp) && !(p->p_flag & P_PPWAIT) &&
 839                     !SIGISMEMBER(p->p_sigignore, SIGTTOU) &&
 840                     !SIGISMEMBER(lp->lwp_sigmask, SIGTTOU)) {
 841                         if (p->p_pgrp->pg_jobc == 0)
 842                                 return (EIO);
 843                         pgsignal(p->p_pgrp, SIGTTOU, 1);
 844                         error = ttysleep(tp, &lbolt, PCATCH, "ttybg1",
 845                                          0);
 846                         if (error)
 847                                 return (error);
 848                 }
 849                 break;
 850         }
 851
 852         switch (cmd) {                  /* Process the ioctl. */
 853         case FIOASYNC:                  /* set/clear async i/o */
 854                 crit_enter();
 855                 if (*(int *)data)
 856                         SET(tp->t_state, TS_ASYNC);
 857                 else
 858                         CLR(tp->t_state, TS_ASYNC);
 859                 crit_exit();
 860                 break;
 861         case FIONREAD:                  /* get # bytes to read */
 862                 crit_enter();
 863                 *(int *)data = ttnread(tp);
 864                 crit_exit();
 865                 break;
 866
 867         case FIOSETOWN:
 868                 /*
 869                  * Policy -- Don't allow FIOSETOWN on someone else's
 870                  *           controlling tty
 871                  */
 872                 if (tp->t_session != NULL && !isctty(p, tp))
 873                         return (ENOTTY);
 874
 875                 error = fsetown(*(int *)data, &tp->t_sigio);
 876                 if (error)
 877                         return (error);
 878                 break;
 879         case FIOGETOWN:
 880                 if (tp->t_session != NULL && !isctty(p, tp))
 881                         return (ENOTTY);
 882                 *(int *)data = fgetown(tp->t_sigio);
 883                 break;
 884
 885         case TIOCEXCL:                  /* set exclusive use of tty */
 886                 crit_enter();
 887                 SET(tp->t_state, TS_XCLUDE);
 888                 crit_exit();
 889                 break;
 890         case TIOCFLUSH: {               /* flush buffers */
 891                 int flags = *(int *)data;
 892
 893                 if (flags == 0)
 894                         flags = FREAD | FWRITE;
 895                 else
 896                         flags &= FREAD | FWRITE;
 897                 ttyflush(tp, flags);
 898                 break;
 899         }
 900         case TIOCCONS:                  /* become virtual console */
 901                 if (*(int *)data) {
 902                         if (constty && constty != tp &&
 903                             ISSET(constty->t_state, TS_CONNECTED))
 904                                 return (EBUSY);
 905 #ifndef UCONSOLE
 906                         if ((error = priv_check(td, PRIV_ROOT)) != 0)
 907                                 return (error);
 908 #endif
 909                         constty = tp;
 910                 } else if (tp == constty)
 911                         constty = NULL;
 912                 break;
 913         case TIOCDRAIN:                 /* wait till output drained */
 914                 error = ttywait(tp);
 915                 if (error)
 916                         return (error);
 917                 break;
 918         case TIOCGETA: {                /* get termios struct */
 919                 struct termios *t = (struct termios *)data;
 920
 921                 bcopy(&tp->t_termios, t, sizeof(struct termios));
 922                 break;
 923         }
 924         case TIOCGETD:                  /* get line discipline */
 925                 *(int *)data = tp->t_line;
 926                 break;
 927         case TIOCGWINSZ:                /* get window size */
 928                 *(struct winsize *)data = tp->t_winsize;
 929                 break;
 930         case TIOCGPGRP:                 /* get pgrp of tty */
 931                 if (!isctty(p, tp))
 932                         return (ENOTTY);
 933                 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
 934                 break;
 935         case TIOCGSID:                  /* get sid of tty */
 936                 if (!isctty(p, tp))
 937                         return (ENOTTY);
 938                 *(int *)data = tp->t_session->s_sid;
 939                 break;
 940 #ifdef TIOCHPCL
 941         case TIOCHPCL:                  /* hang up on last close */
 942                 crit_enter();
 943                 SET(tp->t_cflag, HUPCL);
 944                 crit_exit();
 945                 break;
 946 #endif
 947         case TIOCNXCL:                  /* reset exclusive use of tty */
 948                 crit_enter();
 949                 CLR(tp->t_state, TS_XCLUDE);
 950                 crit_exit();
 951                 break;
 952         case TIOCOUTQ:                  /* output queue size */
 953                 *(int *)data = tp->t_outq.c_cc;
 954                 break;
 955         case TIOCSETA:                  /* set termios struct */
 956         case TIOCSETAW:                 /* drain output, set */
 957         case TIOCSETAF: {               /* drn out, fls in, set */
 958                 struct termios *t = (struct termios *)data;
 959
 960                 if (t->c_ispeed == 0)
 961                         t->c_ispeed = t->c_ospeed;
 962                 if (t->c_ispeed == 0)
 963                         t->c_ispeed = tp->t_ospeed;
 964                 if (t->c_ispeed == 0)
 965                         return (EINVAL);
 966                 crit_enter();
 967                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 968                         error = ttywait(tp);
 969                         if (error) {
 970                                 crit_exit();
 971                                 return (error);
 972                         }
 973                         if (cmd == TIOCSETAF)
 974                                 ttyflush(tp, FREAD);
 975                 }
 976                 if (!ISSET(t->c_cflag, CIGNORE)) {
 977                         /*
 978                          * Set device hardware.
 979                          */
 980                         if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
 981                                 crit_exit();
 982                                 return (error);
 983                         }
 984                         if (ISSET(t->c_cflag, CLOCAL) &&
 985                             !ISSET(tp->t_cflag, CLOCAL)) {
 986                                 /*
 987                                  * XXX disconnections would be too hard to
 988                                  * get rid of without this kludge.  The only
 989                                  * way to get rid of controlling terminals
 990                                  * is to exit from the session leader.
 991                                  */
 992                                 CLR(tp->t_state, TS_ZOMBIE);
 993
 994                                 wakeup(TSA_CARR_ON(tp));
 995                                 ttwakeup(tp);
 996                                 ttwwakeup(tp);
 997                         }
 998                         if ((ISSET(tp->t_state, TS_CARR_ON) ||
 999                              ISSET(t->c_cflag, CLOCAL)) &&
1000                             !ISSET(tp->t_state, TS_ZOMBIE))
1001                                 SET(tp->t_state, TS_CONNECTED);
1002                         else
1003                                 CLR(tp->t_state, TS_CONNECTED);
1004                         tp->t_cflag = t->c_cflag;
1005                         tp->t_ispeed = t->c_ispeed;
1006                         if (t->c_ospeed != 0)
1007                                 tp->t_ospeed = t->c_ospeed;
1008                         ttsetwater(tp);
1009                 }
1010                 if (ISSET(t->c_lflag, ICANON) != ISSET(tp->t_lflag, ICANON) &&
1011                     cmd != TIOCSETAF) {
1012                         if (ISSET(t->c_lflag, ICANON))
1013                                 SET(tp->t_lflag, PENDIN);
1014                         else {
1015                                 /*
1016                                  * XXX we really shouldn't allow toggling
1017                                  * ICANON while we're in a non-termios line
1018                                  * discipline.  Now we have to worry about
1019                                  * panicing for a null queue.
1020                                  */
1021                                 if (tp->t_canq.c_cbreserved > 0 &&
1022                                     tp->t_rawq.c_cbreserved > 0) {
1023                                         catq(&tp->t_rawq, &tp->t_canq);
1024                                         /*
1025                                          * XXX the queue limits may be
1026                                          * different, so the old queue
1027                                          * swapping method no longer works.
1028                                          */
1029                                         catq(&tp->t_canq, &tp->t_rawq);
1030                                 }
1031                                 CLR(tp->t_lflag, PENDIN);
1032                         }
1033                         ttwakeup(tp);
1034                 }
1035                 tp->t_iflag = t->c_iflag;
1036                 tp->t_oflag = t->c_oflag;
1037                 /*
1038                  * Make the EXTPROC bit read only.
1039                  */
1040                 if (ISSET(tp->t_lflag, EXTPROC))
1041                         SET(t->c_lflag, EXTPROC);
1042                 else
1043                         CLR(t->c_lflag, EXTPROC);
1044                 tp->t_lflag = t->c_lflag | ISSET(tp->t_lflag, PENDIN);
1045                 if (t->c_cc[VMIN] != tp->t_cc[VMIN] ||
1046                     t->c_cc[VTIME] != tp->t_cc[VTIME])
1047                         ttwakeup(tp);
1048                 bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc));
1049                 crit_exit();
1050                 break;
1051         }
1052         case TIOCSETD: {                /* set line discipline */
1053                 int t = *(int *)data;
1054                 cdev_t device = tp->t_dev;
1055
1056                 if ((u_int)t >= nlinesw)
1057                         return (ENXIO);
1058                 if (t != tp->t_line) {
1059                         crit_enter();
1060                         (*linesw[tp->t_line].l_close)(tp, flag);
1061                         error = (*linesw[t].l_open)(device, tp);
1062                         if (error) {
1063                                 (void)(*linesw[tp->t_line].l_open)(device, tp);
1064                                 crit_exit();
1065                                 return (error);
1066                         }
1067                         tp->t_line = t;
1068                         crit_exit();
1069                 }
1070                 break;
1071         }
1072         case TIOCSTART:                 /* start output, like ^Q */
1073                 crit_enter();
1074                 if (ISSET(tp->t_state, TS_TTSTOP) ||
1075                     ISSET(tp->t_lflag, FLUSHO)) {
1076                         CLR(tp->t_lflag, FLUSHO);
1077                         CLR(tp->t_state, TS_TTSTOP);
1078                         ttstart(tp);
1079                 }
1080                 crit_exit();
1081                 break;
1082         case TIOCSTI:                   /* simulate terminal input */
1083                 if ((flag & FREAD) == 0 && priv_check(td, PRIV_ROOT))
1084                         return (EPERM);
1085                 if (!isctty(p, tp) && priv_check(td, PRIV_ROOT))
1086                         return (EACCES);
1087                 crit_enter();
1088                 (*linesw[tp->t_line].l_rint)(*(u_char *)data, tp);
1089                 crit_exit();
1090                 break;
1091         case TIOCSTOP:                  /* stop output, like ^S */
1092                 crit_enter();
1093                 if (!ISSET(tp->t_state, TS_TTSTOP)) {
1094                         SET(tp->t_state, TS_TTSTOP);
1095                         (*tp->t_stop)(tp, 0);
1096                 }
1097                 crit_exit();
1098                 break;
1099         case TIOCSCTTY:                 /* become controlling tty */
1100                 /* Session ctty vnode pointer set in vnode layer. */
1101                 if (!SESS_LEADER(p) ||
1102                     ((p->p_session->s_ttyvp || tp->t_session) &&
1103                     (tp->t_session != p->p_session)))
1104                         return (EPERM);
1105                 tp->t_session = p->p_session;
1106                 tp->t_pgrp = p->p_pgrp;
1107                 p->p_session->s_ttyp = tp;
1108                 p->p_flag |= P_CONTROLT;
1109                 break;
1110         case TIOCSPGRP: {               /* set pgrp of tty */
1111                 pid_t pgid = *(int *)data;
1112
1113                 if (!isctty(p, tp))
1114                         return (ENOTTY);
1115                 else if (pgid < 1 || pgid > PID_MAX)
1116                         return (EINVAL);
1117                 else {
1118                         struct pgrp *pgrp = pgfind(pgid);
1119                         if (pgrp == NULL || pgrp->pg_session != p->p_session)
1120                                 return (EPERM);
1121
1122                         tp->t_pgrp = pgrp;
1123                 }
1124                 break;
1125         }
1126         case TIOCSTAT:                  /* simulate control-T */
1127                 crit_enter();
1128                 ttyinfo(tp);
1129                 crit_exit();
1130                 break;
1131         case TIOCSWINSZ:                /* set window size */
1132                 if (bcmp((caddr_t)&tp->t_winsize, data,
1133                     sizeof (struct winsize))) {
1134                         tp->t_winsize = *(struct winsize *)data;
1135                         pgsignal(tp->t_pgrp, SIGWINCH, 1);
1136                 }
1137                 break;
1138         case TIOCSDRAINWAIT:
1139                 error = priv_check(td, PRIV_ROOT);
1140                 if (error)
1141                         return (error);
1142                 tp->t_timeout = *(int *)data * hz;
1143                 wakeup(TSA_OCOMPLETE(tp));
1144                 wakeup(TSA_OLOWAT(tp));
1145                 break;
1146         case TIOCGDRAINWAIT:
1147                 *(int *)data = tp->t_timeout / hz;
1148                 break;
1149         default:
1150 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1151                 return (ttcompat(tp, cmd, data, flag));
1152 #else
1153                 return (ENOIOCTL);
1154 #endif
1155         }
1156         return (0);
1157 }
1158
1159 static struct filterops ttyread_filtops =
1160         { 1, NULL, filt_ttyrdetach, filt_ttyread };
1161 static struct filterops ttywrite_filtops =
1162         { 1, NULL, filt_ttywdetach, filt_ttywrite };
1163
1164 int
1165 ttykqfilter(struct dev_kqfilter_args *ap)
1166 {
1167         cdev_t dev = ap->a_head.a_dev;
1168         struct knote *kn = ap->a_kn;
1169         struct tty *tp = dev->si_tty;
1170         struct klist *klist;
1171
1172         ap->a_result = 0;
1173         switch (kn->kn_filter) {
1174         case EVFILT_READ:
1175                 klist = &tp->t_rsel.si_note;
1176                 kn->kn_fop = &ttyread_filtops;
1177                 break;
1178         case EVFILT_WRITE:
1179                 klist = &tp->t_wsel.si_note;
1180                 kn->kn_fop = &ttywrite_filtops;
1181                 break;
1182         default:
1183                 ap->a_result = EOPNOTSUPP;
1184                 return (0);
1185         }
1186
1187         kn->kn_hook = (caddr_t)dev;
1188
1189         crit_enter();
1190         SLIST_INSERT_HEAD(klist, kn, kn_selnext);
1191         crit_exit();
1192
1193         return (0);
1194 }
1195
1196 static void
1197 filt_ttyrdetach(struct knote *kn)
1198 {
1199         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1200
1201         crit_enter();
1202         SLIST_REMOVE(&tp->t_rsel.si_note, kn, knote, kn_selnext);
1203         crit_exit();
1204 }
1205
1206 static int
1207 filt_ttyread(struct knote *kn, long hint)
1208 {
1209         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1210
1211         kn->kn_data = ttnread(tp);
1212         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1213                 kn->kn_flags |= EV_EOF;
1214                 return (1);
1215         }
1216         return (kn->kn_data > 0);
1217 }
1218
1219 static void
1220 filt_ttywdetach(struct knote *kn)
1221 {
1222         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1223
1224         crit_enter();
1225         SLIST_REMOVE(&tp->t_wsel.si_note, kn, knote, kn_selnext);
1226         crit_exit();
1227 }
1228
1229 static int
1230 filt_ttywrite(struct knote *kn, long hint)
1231 {
1232         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1233
1234         kn->kn_data = tp->t_outq.c_cc;
1235         if (ISSET(tp->t_state, TS_ZOMBIE))
1236                 return (1);
1237         return (kn->kn_data <= tp->t_olowat &&
1238             ISSET(tp->t_state, TS_CONNECTED));
1239 }
1240
1241 /*
1242  * Must be called while in a critical section.
1243  */
1244 static int
1245 ttnread(struct tty *tp)
1246 {
1247         int nread;
1248
1249         if (ISSET(tp->t_lflag, PENDIN))
1250                 ttypend(tp);
1251         nread = tp->t_canq.c_cc;
1252         if (!ISSET(tp->t_lflag, ICANON)) {
1253                 nread += tp->t_rawq.c_cc;
1254                 if (nread < tp->t_cc[VMIN] && tp->t_cc[VTIME] == 0)
1255                         nread = 0;
1256         }
1257         return (nread);
1258 }
1259
1260 /*
1261  * Wait for output to drain.
1262  */
1263 int
1264 ttywait(struct tty *tp)
1265 {
1266         int error;
1267
1268         error = 0;
1269         crit_enter();
1270         while ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
1271                ISSET(tp->t_state, TS_CONNECTED) && tp->t_oproc) {
1272                 (*tp->t_oproc)(tp);
1273                 if ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
1274                     ISSET(tp->t_state, TS_CONNECTED)) {
1275                         SET(tp->t_state, TS_SO_OCOMPLETE);
1276                         error = ttysleep(tp, TSA_OCOMPLETE(tp),
1277                                          PCATCH, "ttywai",
1278                                          tp->t_timeout);
1279                         if (error) {
1280                                 if (error == EWOULDBLOCK)
1281                                         error = EIO;
1282                                 break;
1283                         }
1284                 } else
1285                         break;
1286         }
1287         if (!error && (tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)))
1288                 error = EIO;
1289         crit_exit();
1290         return (error);
1291 }
1292
1293 /*
1294  * Flush if successfully wait.
1295  */
1296 static int
1297 ttywflush(struct tty *tp)
1298 {
1299         int error;
1300
1301         if ((error = ttywait(tp)) == 0)
1302                 ttyflush(tp, FREAD);
1303         return (error);
1304 }
1305
1306 /*
1307  * Flush tty read and/or write queues, notifying anyone waiting.
1308  */
1309 void
1310 ttyflush(struct tty *tp, int rw)
1311 {
1312         crit_enter();
1313 #if 0
1314 again:
1315 #endif
1316         if (rw & FWRITE) {
1317                 FLUSHQ(&tp->t_outq);
1318                 CLR(tp->t_state, TS_TTSTOP);
1319         }
1320         (*tp->t_stop)(tp, rw);
1321         if (rw & FREAD) {
1322                 FLUSHQ(&tp->t_canq);
1323                 FLUSHQ(&tp->t_rawq);
1324                 CLR(tp->t_lflag, PENDIN);
1325                 tp->t_rocount = 0;
1326                 tp->t_rocol = 0;
1327                 CLR(tp->t_state, TS_LOCAL);
1328                 ttwakeup(tp);
1329                 if (ISSET(tp->t_state, TS_TBLOCK)) {
1330                         if (rw & FWRITE)
1331                                 FLUSHQ(&tp->t_outq);
1332                         ttyunblock(tp);
1333
1334                         /*
1335                          * Don't let leave any state that might clobber the
1336                          * next line discipline (although we should do more
1337                          * to send the START char).  Not clearing the state
1338                          * may have caused the "putc to a clist with no
1339                          * reserved cblocks" panic/kprintf.
1340                          */
1341                         CLR(tp->t_state, TS_TBLOCK);
1342
1343 #if 0 /* forget it, sleeping isn't always safe and we don't know when it is */
1344                         if (ISSET(tp->t_iflag, IXOFF)) {
1345                                 /*
1346                                  * XXX wait a bit in the hope that the stop
1347                                  * character (if any) will go out.  Waiting
1348                                  * isn't good since it allows races.  This
1349                                  * will be fixed when the stop character is
1350                                  * put in a special queue.  Don't bother with
1351                                  * the checks in ttywait() since the timeout
1352                                  * will save us.
1353                                  */
1354                                 SET(tp->t_state, TS_SO_OCOMPLETE);
1355                                 ttysleep(tp, TSA_OCOMPLETE(tp), 0,
1356                                          "ttyfls", hz / 10);
1357                                 /*
1358                                  * Don't try sending the stop character again.
1359                                  */
1360                                 CLR(tp->t_state, TS_TBLOCK);
1361                                 goto again;
1362                         }
1363 #endif
1364                 }
1365         }
1366         if (rw & FWRITE) {
1367                 FLUSHQ(&tp->t_outq);
1368                 ttwwakeup(tp);
1369         }
1370         crit_exit();
1371 }
1372
1373 /*
1374  * Copy in the default termios characters.
1375  */
1376 void
1377 termioschars(struct termios *t)
1378 {
1379
1380         bcopy(ttydefchars, t->c_cc, sizeof t->c_cc);
1381 }
1382
1383 /*
1384  * Old interface.
1385  */
1386 void
1387 ttychars(struct tty *tp)
1388 {
1389
1390         termioschars(&tp->t_termios);
1391 }
1392
1393 /*
1394  * Handle input high water.  Send stop character for the IXOFF case.  Turn
1395  * on our input flow control bit and propagate the changes to the driver.
1396  * XXX the stop character should be put in a special high priority queue.
1397  */
1398 void
1399 ttyblock(struct tty *tp)
1400 {
1401
1402         SET(tp->t_state, TS_TBLOCK);
1403         if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTOP] != _POSIX_VDISABLE &&
1404             clist_putc(tp->t_cc[VSTOP], &tp->t_outq) != 0)
1405                 CLR(tp->t_state, TS_TBLOCK);    /* try again later */
1406         ttstart(tp);
1407 }
1408
1409 /*
1410  * Handle input low water.  Send start character for the IXOFF case.  Turn
1411  * off our input flow control bit and propagate the changes to the driver.
1412  * XXX the start character should be put in a special high priority queue.
1413  */
1414 static void
1415 ttyunblock(struct tty *tp)
1416 {
1417
1418         CLR(tp->t_state, TS_TBLOCK);
1419         if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTART] != _POSIX_VDISABLE &&
1420             clist_putc(tp->t_cc[VSTART], &tp->t_outq) != 0)
1421                 SET(tp->t_state, TS_TBLOCK);    /* try again later */
1422         ttstart(tp);
1423 }
1424
1425 #ifdef notyet
1426 /* Not used by any current (i386) drivers. */
1427 /*
1428  * Restart after an inter-char delay.
1429  */
1430 void
1431 ttrstrt(void *tp_arg)
1432 {
1433         struct tty *tp;
1434
1435         KASSERT(tp_arg != NULL, ("ttrstrt"));
1436
1437         tp = tp_arg;
1438         crit_enter();
1439         CLR(tp->t_state, TS_TIMEOUT);
1440         ttstart(tp);
1441         crit_exit();
1442 }
1443 #endif
1444
1445 int
1446 ttstart(struct tty *tp)
1447 {
1448
1449         if (tp->t_oproc != NULL)        /* XXX: Kludge for pty. */
1450                 (*tp->t_oproc)(tp);
1451         return (0);
1452 }
1453
1454 /*
1455  * "close" a line discipline
1456  */
1457 int
1458 ttylclose(struct tty *tp, int flag)
1459 {
1460
1461         if (flag & FNONBLOCK || ttywflush(tp))
1462                 ttyflush(tp, FREAD | FWRITE);
1463         return (0);
1464 }
1465
1466 /*
1467  * Handle modem control transition on a tty.
1468  * Flag indicates new state of carrier.
1469  * Returns 0 if the line should be turned off, otherwise 1.
1470  */
1471 int
1472 ttymodem(struct tty *tp, int flag)
1473 {
1474
1475         if (ISSET(tp->t_state, TS_CARR_ON) && ISSET(tp->t_cflag, MDMBUF)) {
1476                 /*
1477                  * MDMBUF: do flow control according to carrier flag
1478                  * XXX TS_CAR_OFLOW doesn't do anything yet.  TS_TTSTOP
1479                  * works if IXON and IXANY are clear.
1480                  */
1481                 if (flag) {
1482                         CLR(tp->t_state, TS_CAR_OFLOW);
1483                         CLR(tp->t_state, TS_TTSTOP);
1484                         ttstart(tp);
1485                 } else if (!ISSET(tp->t_state, TS_CAR_OFLOW)) {
1486                         SET(tp->t_state, TS_CAR_OFLOW);
1487                         SET(tp->t_state, TS_TTSTOP);
1488                         (*tp->t_stop)(tp, 0);
1489                 }
1490         } else if (flag == 0) {
1491                 /*
1492                  * Lost carrier.
1493                  */
1494                 CLR(tp->t_state, TS_CARR_ON);
1495                 if (ISSET(tp->t_state, TS_ISOPEN) &&
1496                     !ISSET(tp->t_cflag, CLOCAL)) {
1497                         SET(tp->t_state, TS_ZOMBIE);
1498                         CLR(tp->t_state, TS_CONNECTED);
1499                         if (tp->t_session && tp->t_session->s_leader)
1500                                 ksignal(tp->t_session->s_leader, SIGHUP);
1501                         ttyflush(tp, FREAD | FWRITE);
1502                         return (0);
1503                 }
1504         } else {
1505                 /*
1506                  * Carrier now on.
1507                  */
1508                 SET(tp->t_state, TS_CARR_ON);
1509                 if (!ISSET(tp->t_state, TS_ZOMBIE))
1510                         SET(tp->t_state, TS_CONNECTED);
1511                 wakeup(TSA_CARR_ON(tp));
1512                 ttwakeup(tp);
1513                 ttwwakeup(tp);
1514         }
1515         return (1);
1516 }
1517
1518 /*
1519  * Reinput pending characters after state switch
1520  * call from a critical section.
1521  */
1522 static void
1523 ttypend(struct tty *tp)
1524 {
1525         struct clist tq;
1526         int c;
1527
1528         CLR(tp->t_lflag, PENDIN);
1529         SET(tp->t_state, TS_TYPEN);
1530         /*
1531          * XXX this assumes too much about clist internals.  It may even
1532          * fail if the cblock slush pool is empty.  We can't allocate more
1533          * cblocks here because we are called from an interrupt handler
1534          * and clist_alloc_cblocks() can wait.
1535          */
1536         tq = tp->t_rawq;
1537         bzero(&tp->t_rawq, sizeof tp->t_rawq);
1538         tp->t_rawq.c_cbmax = tq.c_cbmax;
1539         tp->t_rawq.c_cbreserved = tq.c_cbreserved;
1540         while ((c = clist_getc(&tq)) >= 0)
1541                 ttyinput(c, tp);
1542         CLR(tp->t_state, TS_TYPEN);
1543 }
1544
1545 /*
1546  * Process a read call on a tty device.
1547  */
1548 int
1549 ttread(struct tty *tp, struct uio *uio, int flag)
1550 {
1551         struct clist *qp;
1552         int c;
1553         tcflag_t lflag;
1554         cc_t *cc = tp->t_cc;
1555         struct proc *pp;
1556         struct lwp *lp;
1557         int first, error = 0;
1558         int has_stime = 0, last_cc = 0;
1559         long slp = 0;           /* XXX this should be renamed `timo'. */
1560         struct timeval stime;
1561
1562         lp = curthread->td_lwp;
1563         stime.tv_sec = 0;       /* fix compiler warnings */
1564         stime.tv_usec = 0;
1565
1566 loop:
1567         crit_enter();
1568         lflag = tp->t_lflag;
1569         /*
1570          * take pending input first
1571          */
1572         if (ISSET(lflag, PENDIN)) {
1573                 ttypend(tp);
1574                 splz();         /* reduce latency */
1575                 lflag = tp->t_lflag;    /* XXX ttypend() clobbers it */
1576         }
1577
1578         /*
1579          * Hang process if it's in the background.
1580          */
1581         if ((pp = curproc) && isbackground(pp, tp)) {
1582                 crit_exit();
1583                 if (SIGISMEMBER(pp->p_sigignore, SIGTTIN) ||
1584                     SIGISMEMBER(lp->lwp_sigmask, SIGTTIN) ||
1585                     (pp->p_flag & P_PPWAIT) || pp->p_pgrp->pg_jobc == 0)
1586                         return (EIO);
1587                 pgsignal(pp->p_pgrp, SIGTTIN, 1);
1588                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg2", 0);
1589                 if (error)
1590                         return (error);
1591                 goto loop;
1592         }
1593
1594         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1595                 crit_exit();
1596                 return (0);     /* EOF */
1597         }
1598
1599         /*
1600          * If canonical, use the canonical queue,
1601          * else use the raw queue.
1602          *
1603          * (should get rid of clists...)
1604          */
1605         qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq;
1606
1607         if (flag & IO_NDELAY) {
1608                 if (qp->c_cc > 0)
1609                         goto read;
1610                 if (!ISSET(lflag, ICANON) && cc[VMIN] == 0) {
1611                         crit_exit();
1612                         return (0);
1613                 }
1614                 crit_exit();
1615                 return (EWOULDBLOCK);
1616         }
1617         if (!ISSET(lflag, ICANON)) {
1618                 int m = cc[VMIN];
1619                 long t = cc[VTIME];
1620                 struct timeval timecopy;
1621
1622                 /*
1623                  * Check each of the four combinations.
1624                  * (m > 0 && t == 0) is the normal read case.
1625                  * It should be fairly efficient, so we check that and its
1626                  * companion case (m == 0 && t == 0) first.
1627                  * For the other two cases, we compute the target sleep time
1628                  * into slp.
1629                  */
1630                 if (t == 0) {
1631                         if (qp->c_cc < m)
1632                                 goto sleep;
1633                         if (qp->c_cc > 0)
1634                                 goto read;
1635
1636                         /* m, t and qp->c_cc are all 0.  0 is enough input. */
1637                         crit_exit();
1638                         return (0);
1639                 }
1640                 t *= 100000;            /* time in us */
1641 #define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 1000000 + \
1642                          ((t1).tv_usec - (t2).tv_usec))
1643                 if (m > 0) {
1644                         if (qp->c_cc <= 0)
1645                                 goto sleep;
1646                         if (qp->c_cc >= m)
1647                                 goto read;
1648                         getmicrotime(&timecopy);
1649                         if (has_stime == 0) {
1650                                 /* first character, start timer */
1651                                 has_stime = 1;
1652                                 stime = timecopy;
1653                                 slp = t;
1654                         } else if (qp->c_cc > last_cc) {
1655                                 /* got a character, restart timer */
1656                                 stime = timecopy;
1657                                 slp = t;
1658                         } else {
1659                                 /* nothing, check expiration */
1660                                 slp = t - diff(timecopy, stime);
1661                                 if (slp <= 0)
1662                                         goto read;
1663                         }
1664                         last_cc = qp->c_cc;
1665                 } else {        /* m == 0 */
1666                         if (qp->c_cc > 0)
1667                                 goto read;
1668                         getmicrotime(&timecopy);
1669                         if (has_stime == 0) {
1670                                 has_stime = 1;
1671                                 stime = timecopy;
1672                                 slp = t;
1673                         } else {
1674                                 slp = t - diff(timecopy, stime);
1675                                 if (slp <= 0) {
1676                                         /* Timed out, but 0 is enough input. */
1677                                         crit_exit();
1678                                         return (0);
1679                                 }
1680                         }
1681                 }
1682 #undef diff
1683                 /*
1684                  * Rounding down may make us wake up just short
1685                  * of the target, so we round up.
1686                  * The formula is ceiling(slp * hz/1000000).
1687                  * 32-bit arithmetic is enough for hz < 169.
1688                  * XXX see tvtohz() for how to avoid overflow if hz
1689                  * is large (divide by `tick' and/or arrange to
1690                  * use tvtohz() if hz is large).
1691                  */
1692                 slp = (long) (((u_long)slp * hz) + 999999) / 1000000;
1693                 goto sleep;
1694         }
1695         if (qp->c_cc <= 0) {
1696 sleep:
1697                 /*
1698                  * There is no input, or not enough input and we can block.
1699                  */
1700                 error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), PCATCH,
1701                                  ISSET(tp->t_state, TS_CONNECTED) ?
1702                                  "ttyin" : "ttyhup", (int)slp);
1703                 crit_exit();
1704                 if (error == EWOULDBLOCK)
1705                         error = 0;
1706                 else if (error)
1707                         return (error);
1708                 /*
1709                  * XXX what happens if another process eats some input
1710                  * while we are asleep (not just here)?  It would be
1711                  * safest to detect changes and reset our state variables
1712                  * (has_stime and last_cc).
1713                  */
1714                 slp = 0;
1715                 goto loop;
1716         }
1717 read:
1718         crit_exit();
1719         /*
1720          * Input present, check for input mapping and processing.
1721          */
1722         first = 1;
1723         if (ISSET(lflag, ICANON | ISIG))
1724                 goto slowcase;
1725         for (;;) {
1726                 char ibuf[IBUFSIZ];
1727                 int icc;
1728
1729                 icc = (int)szmin(uio->uio_resid, IBUFSIZ);
1730                 icc = q_to_b(qp, ibuf, icc);
1731                 if (icc <= 0) {
1732                         if (first)
1733                                 goto loop;
1734                         break;
1735                 }
1736                 error = uiomove(ibuf, (size_t)icc, uio);
1737                 /*
1738                  * XXX if there was an error then we should ungetc() the
1739                  * unmoved chars and reduce icc here.
1740                  */
1741                 if (error)
1742                         break;
1743                 if (uio->uio_resid == 0)
1744                         break;
1745                 first = 0;
1746         }
1747         goto out;
1748 slowcase:
1749         for (;;) {
1750                 c = clist_getc(qp);
1751                 if (c < 0) {
1752                         if (first)
1753                                 goto loop;
1754                         break;
1755                 }
1756                 /*
1757                  * delayed suspend (^Y)
1758                  */
1759                 if (CCEQ(cc[VDSUSP], c) &&
1760                     ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) {
1761                         pgsignal(tp->t_pgrp, SIGTSTP, 1);
1762                         if (first) {
1763                                 error = ttysleep(tp, &lbolt, PCATCH,
1764                                                  "ttybg3", 0);
1765                                 if (error)
1766                                         break;
1767                                 goto loop;
1768                         }
1769                         break;
1770                 }
1771                 /*
1772                  * Interpret EOF only in canonical mode.
1773                  */
1774                 if (CCEQ(cc[VEOF], c) && ISSET(lflag, ICANON))
1775                         break;
1776                 /*
1777                  * Give user character.
1778                  */
1779                 error = ureadc(c, uio);
1780                 if (error)
1781                         /* XXX should ungetc(c, qp). */
1782                         break;
1783                 if (uio->uio_resid == 0)
1784                         break;
1785                 /*
1786                  * In canonical mode check for a "break character"
1787                  * marking the end of a "line of input".
1788                  */
1789                 if (ISSET(lflag, ICANON) && TTBREAKC(c, lflag))
1790                         break;
1791                 first = 0;
1792         }
1793
1794 out:
1795         /*
1796          * Look to unblock input now that (presumably)
1797          * the input queue has gone down.
1798          */
1799         crit_enter();
1800         if (ISSET(tp->t_state, TS_TBLOCK) &&
1801             tp->t_rawq.c_cc + tp->t_canq.c_cc <= tp->t_ilowat)
1802                 ttyunblock(tp);
1803         crit_exit();
1804
1805         return (error);
1806 }
1807
1808 /*
1809  * Check the output queue on tp for space for a kernel message (from uprintf
1810  * or tprintf).  Allow some space over the normal hiwater mark so we don't
1811  * lose messages due to normal flow control, but don't let the tty run amok.
1812  * Sleeps here are not interruptible, but we return prematurely if new signals
1813  * arrive.
1814  */
1815 int
1816 ttycheckoutq(struct tty *tp, int wait)
1817 {
1818         struct lwp *lp = curthread->td_lwp;
1819         int hiwat;
1820         sigset_t oldset, newset;
1821
1822         hiwat = tp->t_ohiwat;
1823         SIGEMPTYSET(oldset);
1824         SIGEMPTYSET(newset);
1825         crit_enter();
1826         if (wait)
1827                 oldset = lwp_sigpend(lp);
1828         if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100) {
1829                 while (tp->t_outq.c_cc > hiwat) {
1830                         ttstart(tp);
1831                         if (tp->t_outq.c_cc <= hiwat)
1832                                 break;
1833                         if (wait)
1834                                 newset = lwp_sigpend(lp);
1835                         if (!wait || SIGSETNEQ(oldset, newset)) {
1836                                 crit_exit();
1837                                 return (0);
1838                         }
1839                         SET(tp->t_state, TS_SO_OLOWAT);
1840                         tsleep(TSA_OLOWAT(tp), 0, "ttoutq", hz);
1841                 }
1842         }
1843         crit_exit();
1844         return (1);
1845 }
1846
1847 /*
1848  * Process a write call on a tty device.
1849  */
1850 int
1851 ttwrite(struct tty *tp, struct uio *uio, int flag)
1852 {
1853         char *cp = NULL;
1854         int cc, ce;
1855         struct proc *pp;
1856         struct lwp *lp;
1857         int i, hiwat, error;
1858         size_t cnt;
1859
1860         char obuf[OBUFSIZ];
1861
1862         lp = curthread->td_lwp;
1863         hiwat = tp->t_ohiwat;
1864         cnt = uio->uio_resid;
1865         error = 0;
1866         cc = 0;
1867 loop:
1868         crit_enter();
1869         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1870                 crit_exit();
1871                 if (uio->uio_resid == cnt)
1872                         error = EIO;
1873                 goto out;
1874         }
1875         if (!ISSET(tp->t_state, TS_CONNECTED)) {
1876                 if (flag & IO_NDELAY) {
1877                         crit_exit();
1878                         error = EWOULDBLOCK;
1879                         goto out;
1880                 }
1881                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ttydcd", 0);
1882                 crit_exit();
1883                 if (error)
1884                         goto out;
1885                 goto loop;
1886         }
1887         crit_exit();
1888
1889         /*
1890          * Hang the process if it's in the background.
1891          */
1892         if ((pp = curproc) && isbackground(pp, tp) &&
1893             ISSET(tp->t_lflag, TOSTOP) && !(pp->p_flag & P_PPWAIT) &&
1894             !SIGISMEMBER(pp->p_sigignore, SIGTTOU) &&
1895             !SIGISMEMBER(lp->lwp_sigmask, SIGTTOU)) {
1896                 if (pp->p_pgrp->pg_jobc == 0) {
1897                         error = EIO;
1898                         goto out;
1899                 }
1900                 pgsignal(pp->p_pgrp, SIGTTOU, 1);
1901                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg4", 0);
1902                 if (error)
1903                         goto out;
1904                 goto loop;
1905         }
1906         /*
1907          * Process the user's data in at most OBUFSIZ chunks.  Perform any
1908          * output translation.  Keep track of high water mark, sleep on
1909          * overflow awaiting device aid in acquiring new space.
1910          */
1911         while (uio->uio_resid > 0 || cc > 0) {
1912                 if (ISSET(tp->t_lflag, FLUSHO)) {
1913                         uio->uio_resid = 0;
1914                         return (0);
1915                 }
1916                 if (tp->t_outq.c_cc > hiwat)
1917                         goto ovhiwat;
1918                 /*
1919                  * Grab a hunk of data from the user, unless we have some
1920                  * leftover from last time.
1921                  */
1922                 if (cc == 0) {
1923                         cc = szmin(uio->uio_resid, OBUFSIZ);
1924                         cp = obuf;
1925                         error = uiomove(cp, (size_t)cc, uio);
1926                         if (error) {
1927                                 cc = 0;
1928                                 break;
1929                         }
1930                 }
1931                 /*
1932                  * If nothing fancy need be done, grab those characters we
1933                  * can handle without any of ttyoutput's processing and
1934                  * just transfer them to the output q.  For those chars
1935                  * which require special processing (as indicated by the
1936                  * bits in char_type), call ttyoutput.  After processing
1937                  * a hunk of data, look for FLUSHO so ^O's will take effect
1938                  * immediately.
1939                  */
1940                 while (cc > 0) {
1941                         if (!ISSET(tp->t_oflag, OPOST))
1942                                 ce = cc;
1943                         else {
1944                                 ce = cc - scanc((u_int)cc, (u_char *)cp,
1945                                                 char_type, CCLASSMASK);
1946                                 /*
1947                                  * If ce is zero, then we're processing
1948                                  * a special character through ttyoutput.
1949                                  */
1950                                 if (ce == 0) {
1951                                         tp->t_rocount = 0;
1952                                         if (ttyoutput(*cp, tp) >= 0) {
1953                                                 /* No Clists, wait a bit. */
1954                                                 ttstart(tp);
1955                                                 if (flag & IO_NDELAY) {
1956                                                         error = EWOULDBLOCK;
1957                                                         goto out;
1958                                                 }
1959                                                 error = ttysleep(tp, &lbolt,
1960                                                                  PCATCH,
1961                                                                  "ttybf1", 0);
1962                                                 if (error)
1963                                                         goto out;
1964                                                 goto loop;
1965                                         }
1966                                         cp++;
1967                                         cc--;
1968                                         if (ISSET(tp->t_lflag, FLUSHO) ||
1969                                             tp->t_outq.c_cc > hiwat)
1970                                                 goto ovhiwat;
1971                                         continue;
1972                                 }
1973                         }
1974                         /*
1975                          * A bunch of normal characters have been found.
1976                          * Transfer them en masse to the output queue and
1977                          * continue processing at the top of the loop.
1978                          * If there are any further characters in this
1979                          * <= OBUFSIZ chunk, the first should be a character
1980                          * requiring special handling by ttyoutput.
1981                          */
1982                         tp->t_rocount = 0;
1983                         i = b_to_q(cp, ce, &tp->t_outq);
1984                         ce -= i;
1985                         tp->t_column += ce;
1986                         cp += ce, cc -= ce, tk_nout += ce;
1987                         tp->t_outcc += ce;
1988                         if (i > 0) {
1989                                 /* No Clists, wait a bit. */
1990                                 ttstart(tp);
1991                                 if (flag & IO_NDELAY) {
1992                                         error = EWOULDBLOCK;
1993                                         goto out;
1994                                 }
1995                                 error = ttysleep(tp, &lbolt, PCATCH,
1996                                                  "ttybf2", 0);
1997                                 if (error)
1998                                         goto out;
1999                                 goto loop;
2000                         }
2001                         if (ISSET(tp->t_lflag, FLUSHO) ||
2002                             tp->t_outq.c_cc > hiwat)
2003                                 break;
2004                 }
2005                 ttstart(tp);
2006         }
2007 out:
2008         /*
2009          * If cc is nonzero, we leave the uio structure inconsistent, as the
2010          * offset and iov pointers have moved forward, but it doesn't matter
2011          * (the call will either return short or restart with a new uio).
2012          */
2013         uio->uio_resid += cc;
2014         return (error);
2015
2016 ovhiwat:
2017         ttstart(tp);
2018         crit_enter();
2019         /*
2020          * This can only occur if FLUSHO is set in t_lflag,
2021          * or if ttstart/oproc is synchronous (or very fast).
2022          */
2023         if (tp->t_outq.c_cc <= hiwat) {
2024                 crit_exit();
2025                 goto loop;
2026         }
2027         if (flag & IO_NDELAY) {
2028                 crit_exit();
2029                 uio->uio_resid += cc;
2030                 return (uio->uio_resid == cnt ? EWOULDBLOCK : 0);
2031         }
2032         SET(tp->t_state, TS_SO_OLOWAT);
2033         error = ttysleep(tp, TSA_OLOWAT(tp), PCATCH, "ttywri", tp->t_timeout);
2034         crit_exit();
2035         if (error == EWOULDBLOCK)
2036                 error = EIO;
2037         if (error)
2038                 goto out;
2039         goto loop;
2040 }
2041
2042 /*
2043  * Rubout one character from the rawq of tp
2044  * as cleanly as possible.
2045  */
2046 static void
2047 ttyrub(int c, struct tty *tp)
2048 {
2049         char *cp;
2050         int savecol;
2051         int tabc;
2052
2053         if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC))
2054                 return;
2055         CLR(tp->t_lflag, FLUSHO);
2056         if (ISSET(tp->t_lflag, ECHOE)) {
2057                 if (tp->t_rocount == 0) {
2058                         /*
2059                          * Screwed by ttwrite; retype
2060                          */
2061                         ttyretype(tp);
2062                         return;
2063                 }
2064                 if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE))
2065                         ttyrubo(tp, 2);
2066                 else {
2067                         CLR(c, ~TTY_CHARMASK);
2068                         switch (CCLASS(c)) {
2069                         case ORDINARY:
2070                                 ttyrubo(tp, 1);
2071                                 break;
2072                         case BACKSPACE:
2073                         case CONTROL:
2074                         case NEWLINE:
2075                         case RETURN:
2076                         case VTAB:
2077                                 if (ISSET(tp->t_lflag, ECHOCTL))
2078                                         ttyrubo(tp, 2);
2079                                 break;
2080                         case TAB:
2081                                 if (tp->t_rocount < tp->t_rawq.c_cc) {
2082                                         ttyretype(tp);
2083                                         return;
2084                                 }
2085                                 crit_enter();
2086                                 savecol = tp->t_column;
2087                                 SET(tp->t_state, TS_CNTTB);
2088                                 SET(tp->t_lflag, FLUSHO);
2089                                 tp->t_column = tp->t_rocol;
2090                                 cp = tp->t_rawq.c_cf;
2091                                 if (cp)
2092                                         tabc = *cp;     /* XXX FIX NEXTC */
2093                                 for (; cp; cp = nextc(&tp->t_rawq, cp, &tabc))
2094                                         ttyecho(tabc, tp);
2095                                 CLR(tp->t_lflag, FLUSHO);
2096                                 CLR(tp->t_state, TS_CNTTB);
2097                                 crit_exit();
2098
2099                                 /* savecol will now be length of the tab. */
2100                                 savecol -= tp->t_column;
2101                                 tp->t_column += savecol;
2102                                 if (savecol > 8)
2103                                         savecol = 8;    /* overflow screw */
2104                                 while (--savecol >= 0)
2105                                         (void)ttyoutput('\b', tp);
2106                                 break;
2107                         default:                        /* XXX */
2108 #define PANICSTR        "ttyrub: would panic c = %d, val = %d\n"
2109                                 (void)kprintf(PANICSTR, c, CCLASS(c));
2110 #ifdef notdef
2111                                 panic(PANICSTR, c, CCLASS(c));
2112 #endif
2113                         }
2114                 }
2115         } else if (ISSET(tp->t_lflag, ECHOPRT)) {
2116                 if (!ISSET(tp->t_state, TS_ERASE)) {
2117                         SET(tp->t_state, TS_ERASE);
2118                         (void)ttyoutput('\\', tp);
2119                 }
2120                 ttyecho(c, tp);
2121         } else {
2122                 ttyecho(tp->t_cc[VERASE], tp);
2123                 /*
2124                  * This code may be executed not only when an ERASE key
2125                  * is pressed, but also when ^U (KILL) or ^W (WERASE) are.
2126                  * So, I didn't think it was worthwhile to pass the extra
2127                  * information (which would need an extra parameter,
2128                  * changing every call) needed to distinguish the ERASE2
2129                  * case from the ERASE.
2130                  */
2131         }
2132         --tp->t_rocount;
2133 }
2134
2135 /*
2136  * Back over cnt characters, erasing them.
2137  */
2138 static void
2139 ttyrubo(struct tty *tp, int cnt)
2140 {
2141
2142         while (cnt-- > 0) {
2143                 (void)ttyoutput('\b', tp);
2144                 (void)ttyoutput(' ', tp);
2145                 (void)ttyoutput('\b', tp);
2146         }
2147 }
2148
2149 /*
2150  * ttyretype --
2151  *      Reprint the rawq line.  Note, it is assumed that c_cc has already
2152  *      been checked.
2153  */
2154 static void
2155 ttyretype(struct tty *tp)
2156 {
2157         char *cp;
2158         int c;
2159
2160         /* Echo the reprint character. */
2161         if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
2162                 ttyecho(tp->t_cc[VREPRINT], tp);
2163
2164         (void)ttyoutput('\n', tp);
2165
2166         /*
2167          * XXX
2168          * FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE
2169          * BIT OF FIRST CHAR.
2170          */
2171         crit_enter();
2172         for (cp = tp->t_canq.c_cf, c = (cp != NULL ? *cp : 0);
2173             cp != NULL; cp = nextc(&tp->t_canq, cp, &c))
2174                 ttyecho(c, tp);
2175         for (cp = tp->t_rawq.c_cf, c = (cp != NULL ? *cp : 0);
2176             cp != NULL; cp = nextc(&tp->t_rawq, cp, &c))
2177                 ttyecho(c, tp);
2178         CLR(tp->t_state, TS_ERASE);
2179         crit_exit();
2180
2181         tp->t_rocount = tp->t_rawq.c_cc;
2182         tp->t_rocol = 0;
2183 }
2184
2185 /*
2186  * Echo a typed character to the terminal.
2187  */
2188 static void
2189 ttyecho(int c, struct tty *tp)
2190 {
2191
2192         if (!ISSET(tp->t_state, TS_CNTTB))
2193                 CLR(tp->t_lflag, FLUSHO);
2194         if ((!ISSET(tp->t_lflag, ECHO) &&
2195              (c != '\n' || !ISSET(tp->t_lflag, ECHONL))) ||
2196             ISSET(tp->t_lflag, EXTPROC))
2197                 return;
2198         if (ISSET(tp->t_lflag, ECHOCTL) &&
2199             ((ISSET(c, TTY_CHARMASK) <= 037 && c != '\t' && c != '\n') ||
2200             ISSET(c, TTY_CHARMASK) == 0177)) {
2201                 (void)ttyoutput('^', tp);
2202                 CLR(c, ~TTY_CHARMASK);
2203                 if (c == 0177)
2204                         c = '?';
2205                 else
2206                         c += 'A' - 1;
2207         }
2208         (void)ttyoutput(c, tp);
2209 }
2210
2211 /*
2212  * Wake up any readers on a tty.
2213  */
2214 void
2215 ttwakeup(struct tty *tp)
2216 {
2217
2218         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2219                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2220         wakeup(TSA_HUP_OR_INPUT(tp));
2221         KNOTE(&tp->t_rsel.si_note, 0);
2222 }
2223
2224 /*
2225  * Wake up any writers on a tty.
2226  */
2227 void
2228 ttwwakeup(struct tty *tp)
2229 {
2230
2231         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2232                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2233         if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
2234             TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
2235                 CLR(tp->t_state, TS_SO_OCOMPLETE);
2236                 wakeup(TSA_OCOMPLETE(tp));
2237         }
2238         if (ISSET(tp->t_state, TS_SO_OLOWAT) &&
2239             tp->t_outq.c_cc <= tp->t_olowat) {
2240                 CLR(tp->t_state, TS_SO_OLOWAT);
2241                 wakeup(TSA_OLOWAT(tp));
2242         }
2243         KNOTE(&tp->t_wsel.si_note, 0);
2244 }
2245
2246 /*
2247  * Look up a code for a specified speed in a conversion table;
2248  * used by drivers to map software speed values to hardware parameters.
2249  */
2250 int
2251 ttspeedtab(int speed, struct speedtab *table)
2252 {
2253
2254         for ( ; table->sp_speed != -1; table++)
2255                 if (table->sp_speed == speed)
2256                         return (table->sp_code);
2257         return (-1);
2258 }
2259
2260 /*
2261  * Set input and output watermarks and buffer sizes.  For input, the
2262  * high watermark is about one second's worth of input above empty, the
2263  * low watermark is slightly below high water, and the buffer size is a
2264  * driver-dependent amount above high water.  For output, the watermarks
2265  * are near the ends of the buffer, with about 1 second's worth of input
2266  * between them.  All this only applies to the standard line discipline.
2267  */
2268 void
2269 ttsetwater(struct tty *tp)
2270 {
2271         int cps, ttmaxhiwat, x;
2272
2273         /* Input. */
2274         clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
2275         switch (tp->t_ispeedwat) {
2276         case (speed_t)-1:
2277                 cps = tp->t_ispeed / 10;
2278                 break;
2279         case 0:
2280                 /*
2281                  * This case is for old drivers that don't know about
2282                  * t_ispeedwat.  Arrange for them to get the old buffer
2283                  * sizes and watermarks.
2284                  */
2285                 cps = TTYHOG - 2 * 256;
2286                 tp->t_ififosize = 2 * 2048;
2287                 break;
2288         default:
2289                 cps = tp->t_ispeedwat / 10;
2290                 break;
2291         }
2292         tp->t_ihiwat = cps;
2293         tp->t_ilowat = 7 * cps / 8;
2294         x = cps + tp->t_ififosize;
2295         clist_alloc_cblocks(&tp->t_rawq, x, x);
2296
2297         /* Output. */
2298         switch (tp->t_ospeedwat) {
2299         case (speed_t)-1:
2300                 cps = tp->t_ospeed / 10;
2301                 ttmaxhiwat = 2 * TTMAXHIWAT;
2302                 break;
2303         case 0:
2304                 cps = tp->t_ospeed / 10;
2305                 ttmaxhiwat = TTMAXHIWAT;
2306                 break;
2307         default:
2308                 cps = tp->t_ospeedwat / 10;
2309                 ttmaxhiwat = 8 * TTMAXHIWAT;
2310                 break;
2311         }
2312 #define CLAMP(x, h, l)  ((x) > h ? h : ((x) < l) ? l : (x))
2313         tp->t_olowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
2314         x += cps;
2315         x = CLAMP(x, ttmaxhiwat, TTMINHIWAT);   /* XXX clamps are too magic */
2316         tp->t_ohiwat = roundup(x, CBSIZE);      /* XXX for compat */
2317         x = imax(tp->t_ohiwat, TTMAXHIWAT);     /* XXX for compat/safety */
2318         x += OBUFSIZ + 100;
2319         clist_alloc_cblocks(&tp->t_outq, x, x);
2320 #undef  CLAMP
2321 }
2322
2323 /*
2324  * Report on state of foreground process group.
2325  */
2326 void
2327 ttyinfo(struct tty *tp)
2328 {
2329         struct proc *p, *pick;
2330         struct lwp *lp;
2331         struct rusage ru;
2332         int tmp;
2333
2334         if (ttycheckoutq(tp,0) == 0)
2335                 return;
2336
2337         /*
2338          * We always print the load average, then figure out what else to
2339          * print based on the state of the current process group.
2340          */
2341         tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
2342         ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
2343
2344         if (tp->t_session == NULL) {
2345                 ttyprintf(tp, "not a controlling terminal\n");
2346         } else if (tp->t_pgrp == NULL) {
2347                 ttyprintf(tp, "no foreground process group\n");
2348         } else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0) {
2349                 ttyprintf(tp, "empty foreground process group\n");
2350         } else {
2351                 /*
2352                  * Pick an interesting process.  Note that certain elements,
2353                  * in particular the wmesg, require a critical section for
2354                  * safe access (YYY and we are still not MP safe).
2355                  *
2356                  * NOTE: lwp_wmesg is lwp_thread->td_wmesg.
2357                  */
2358                 char buf[64];
2359                 const char *str;
2360                 long vmsz;
2361                 int pctcpu;
2362
2363                 crit_enter();
2364
2365                 /* XXX lwp should compare lwps */
2366
2367                 for (pick = NULL; p != 0; p = LIST_NEXT(p, p_pglist)) {
2368                         if (proc_compare(pick, p))
2369                                 pick = p;
2370                 }
2371
2372                 /* XXX lwp */
2373                 lp = FIRST_LWP_IN_PROC(pick);
2374                 if (lp == NULL) {
2375                         ttyprintf(tp, "foreground process without lwp\n");
2376                         tp->t_rocount = 0;
2377                         crit_exit();
2378                         return;
2379                 }
2380
2381                 /*
2382                  * Figure out what wait/process-state message, and command
2383                  * buffer to present
2384                  */
2385                 /*
2386                  * XXX lwp This is a horrible mixture.  We need to rework this
2387                  * as soon as lwps have their own runnable status.
2388                  */
2389                 if (pick->p_flag & P_WEXIT)
2390                         str = "exiting";
2391                 else if (lp->lwp_stat == LSRUN)
2392                         str = "running";
2393                 else if (pick->p_stat == SIDL)
2394                         str = "spawning";
2395                 else if (lp->lwp_wmesg) /* lwp_thread must not be NULL */
2396                         str = lp->lwp_wmesg;
2397                 else
2398                         str = "iowait";
2399
2400                 ksnprintf(buf, sizeof(buf), "cmd: %s %d [%s]",
2401                         pick->p_comm, pick->p_pid, str);
2402
2403                 /*
2404                  * Calculate cpu usage, percent cpu, and cmsz.  Note that
2405                  * 'pick' becomes invalid the moment we exit the critical
2406                  * section.
2407                  */
2408                 if (lp->lwp_thread && (pick->p_flag & P_SWAPPEDOUT) == 0)
2409                         calcru_proc(pick, &ru);
2410
2411                 pctcpu = (lp->lwp_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
2412
2413                 if (pick->p_stat == SIDL || pick->p_stat == SZOMB)
2414                     vmsz = 0;
2415                 else
2416                     vmsz = pgtok(vmspace_resident_count(pick->p_vmspace));
2417
2418                 crit_exit();
2419
2420                 /*
2421                  * Dump the output
2422                  */
2423                 ttyprintf(tp, " %s ", buf);
2424                 ttyprintf(tp, "%ld.%02ldu ",
2425                         ru.ru_utime.tv_sec, ru.ru_utime.tv_usec / 10000);
2426                 ttyprintf(tp, "%ld.%02lds ",
2427                         ru.ru_stime.tv_sec, ru.ru_stime.tv_usec / 10000);
2428                 ttyprintf(tp, "%d%% %ldk\n", pctcpu / 100, vmsz);
2429         }
2430         tp->t_rocount = 0;      /* so pending input will be retyped if BS */
2431 }
2432
2433 /*
2434  * Returns 1 if p2 is "better" than p1
2435  *
2436  * The algorithm for picking the "interesting" process is thus:
2437  *
2438  *      1) Only foreground processes are eligible - implied.
2439  *      2) Runnable processes are favored over anything else.  The runner
2440  *         with the highest cpu utilization is picked (p_cpticks).  Ties are
2441  *         broken by picking the highest pid.
2442  *      3) The sleeper with the shortest sleep time is next.  With ties,
2443  *         we pick out just "short-term" sleepers (LWP_SINTR == 0).
2444  *      4) Further ties are broken by picking the highest pid.
2445  */
2446 #define ISRUN(lp)       ((lp)->lwp_stat == LSRUN)
2447 #define TESTAB(a, b)    ((a)<<1 | (b))
2448 #define ONLYA   2
2449 #define ONLYB   1
2450 #define BOTH    3
2451
2452 static int
2453 proc_compare(struct proc *p1, struct proc *p2)
2454 {
2455         struct lwp *lp1, *lp2;
2456         if (p1 == NULL)
2457                 return (1);
2458
2459         /*
2460          * weed out zombies
2461          */
2462         switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) {
2463         case ONLYA:
2464                 return (1);
2465         case ONLYB:
2466                 return (0);
2467         case BOTH:
2468                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2469         }
2470
2471         /* XXX lwp */
2472         lp1 = FIRST_LWP_IN_PROC(p1);
2473         lp2 = FIRST_LWP_IN_PROC(p2);
2474
2475         /*
2476          * see if at least one of them is runnable
2477          */
2478         switch (TESTAB(ISRUN(lp1), ISRUN(lp2))) {
2479         case ONLYA:
2480                 return (0);
2481         case ONLYB:
2482                 return (1);
2483         case BOTH:
2484                 /*
2485                  * tie - favor one with highest recent cpu utilization
2486                  */
2487                 if (lp2->lwp_cpticks > lp1->lwp_cpticks)
2488                         return (1);
2489                 if (lp1->lwp_cpticks > lp2->lwp_cpticks)
2490                         return (0);
2491                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2492         }
2493         /*
2494          * pick the one with the smallest sleep time
2495          */
2496         if (lp2->lwp_slptime > lp1->lwp_slptime)
2497                 return (0);
2498         if (lp1->lwp_slptime > lp2->lwp_slptime)
2499                 return (1);
2500         /*
2501          * favor one sleeping in a non-interruptible sleep
2502          */
2503         if (lp1->lwp_flag & LWP_SINTR && (lp2->lwp_flag & LWP_SINTR) == 0)
2504                 return (1);
2505         if (lp2->lwp_flag & LWP_SINTR && (lp1->lwp_flag & LWP_SINTR) == 0)
2506                 return (0);
2507         return (p2->p_pid > p1->p_pid);         /* tie - return highest pid */
2508 }
2509
2510 /*
2511  * Output char to tty; console putchar style.
2512  */
2513 int
2514 tputchar(int c, struct tty *tp)
2515 {
2516         crit_enter();
2517         if (!ISSET(tp->t_state, TS_CONNECTED)) {
2518                 crit_exit();
2519                 return (-1);
2520         }
2521         if (c == '\n')
2522                 (void)ttyoutput('\r', tp);
2523         (void)ttyoutput(c, tp);
2524         ttstart(tp);
2525         crit_exit();
2526         return (0);
2527 }
2528
2529 /*
2530  * Sleep on chan, returning ERESTART if tty changed while we napped and
2531  * returning any errors (e.g. EINTR/EWOULDBLOCK) reported by tsleep.  If
2532  * the tty is revoked, restarting a pending call will redo validation done
2533  * at the start of the call.
2534  */
2535 int
2536 ttysleep(struct tty *tp, void *chan, int slpflags, char *wmesg, int timo)
2537 {
2538         int error;
2539         int gen;
2540
2541         gen = tp->t_gen;
2542         error = tsleep(chan, slpflags, wmesg, timo);
2543         if (error)
2544                 return (error);
2545         return (tp->t_gen == gen ? 0 : ERESTART);
2546 }
2547
2548 /*
2549  * Revoke a tty.
2550  *
2551  * We bump the gen to force any ttysleep()'s to return with ERESTART
2552  * and flush the tty.  The related fp's should already have been
2553  * replaced so the tty will close when the last references on the
2554  * original fp's go away.
2555  */
2556 int
2557 ttyrevoke(struct dev_revoke_args *ap)
2558 {
2559         struct tty *tp;
2560
2561         tp = ap->a_head.a_dev->si_tty;
2562         tp->t_gen++;
2563         ttyflush(tp, FREAD | FWRITE);
2564         wakeup(TSA_CARR_ON(tp));
2565         ttwakeup(tp);
2566         ttwwakeup(tp);
2567         return (0);
2568 }
2569
2570 /*
2571  * Allocate a tty struct.  Clists in the struct will be allocated by
2572  * ttyopen().
2573  */
2574 struct tty *
2575 ttymalloc(struct tty *tp)
2576 {
2577
2578         if (tp) {
2579                 return(tp);
2580         }
2581         tp = kmalloc(sizeof *tp, M_TTYS, M_WAITOK|M_ZERO);
2582         ttyregister(tp);
2583         return (tp);
2584 }
2585
2586 #if 0
2587 /*
2588  * Free a tty struct.  Clists in the struct should have been freed by
2589  * ttyclose().
2590  *
2591  * XXX not yet usable: since we support a half-closed state and do not
2592  * ref count the tty reference from the session, it is possible for a
2593  * session to hold a ref on the tty.  See TTY_DO_FULL_CLOSE.
2594  */
2595 void
2596 ttyfree(struct tty *tp)
2597 {
2598         kfree(tp, M_TTYS);
2599 }
2600 #endif /* 0 */
2601
2602 void
2603 ttyregister(struct tty *tp)
2604 {
2605         SLIST_INSERT_HEAD(&tty_list, tp, t_list);
2606 }
2607
2608 static int
2609 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
2610 {
2611         int error;
2612         struct tty *tp, t;
2613         SLIST_FOREACH(tp, &tty_list, t_list) {
2614                 t = *tp;
2615                 if (t.t_dev)
2616                         t.t_dev = (cdev_t)(uintptr_t)dev2udev(t.t_dev);
2617                 error = SYSCTL_OUT(req, (caddr_t)&t, sizeof(t));
2618                 if (error)
2619                         return (error);
2620         }
2621         return (0);
2622 }
2623
2624 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD,
2625         0, 0, sysctl_kern_ttys, "S,tty", "All struct ttys");
2626
2627 void
2628 nottystop(struct tty *tp, int rw)
2629 {
2630
2631         return;
2632 }
2633
2634 int
2635 ttyread(struct dev_read_args *ap)
2636 {
2637         struct tty *tp;
2638
2639         tp = ap->a_head.a_dev->si_tty;
2640         if (tp == NULL)
2641                 return (ENODEV);
2642         return ((*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag));
2643 }
2644
2645 int
2646 ttywrite(struct dev_write_args *ap)
2647 {
2648         struct tty *tp;
2649
2650         tp = ap->a_head.a_dev->si_tty;
2651         if (tp == NULL)
2652                 return (ENODEV);
2653         return ((*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag));
2654 }