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/poll.h>
  90 #include <sys/kernel.h>
  91 #include <sys/vnode.h>
  92 #include <sys/signalvar.h>
  93 #include <sys/signal2.h>
  94 #include <sys/resourcevar.h>
  95 #include <sys/malloc.h>
  96 #include <sys/filedesc.h>
  97 #include <sys/sysctl.h>
  98 #include <sys/thread2.h>
  99
 100 #include <vm/vm.h>
 101 #include <sys/lock.h>
 102 #include <vm/pmap.h>
 103 #include <vm/vm_map.h>
 104
 105 MALLOC_DEFINE(M_TTYS, "ttys", "tty data structures");
 106
 107 static int      proc_compare (struct proc *p1, struct proc *p2);
 108 static int      ttnread (struct tty *tp);
 109 static void     ttyecho (int c, struct tty *tp);
 110 static int      ttyoutput (int c, struct tty *tp);
 111 static void     ttypend (struct tty *tp);
 112 static void     ttyretype (struct tty *tp);
 113 static void     ttyrub (int c, struct tty *tp);
 114 static void     ttyrubo (struct tty *tp, int cnt);
 115 static void     ttyunblock (struct tty *tp);
 116 static int      ttywflush (struct tty *tp);
 117 static int      filt_ttyread (struct knote *kn, long hint);
 118 static void     filt_ttyrdetach (struct knote *kn);
 119 static int      filt_ttywrite (struct knote *kn, long hint);
 120 static void     filt_ttywdetach (struct knote *kn);
 121
 122 /*
 123  * Table with character classes and parity. The 8th bit indicates parity,
 124  * the 7th bit indicates the character is an alphameric or underscore (for
 125  * ALTWERASE), and the low 6 bits indicate delay type.  If the low 6 bits
 126  * are 0 then the character needs no special processing on output; classes
 127  * other than 0 might be translated or (not currently) require delays.
 128  */
 129 #define E       0x00    /* Even parity. */
 130 #define O       0x80    /* Odd parity. */
 131 #define PARITY(c)       (char_type[c] & O)
 132
 133 #define ALPHA   0x40    /* Alpha or underscore. */
 134 #define ISALPHA(c)      (char_type[(c) & TTY_CHARMASK] & ALPHA)
 135
 136 #define CCLASSMASK      0x3f
 137 #define CCLASS(c)       (char_type[c] & CCLASSMASK)
 138
 139 #define BS      BACKSPACE
 140 #define CC      CONTROL
 141 #define CR      RETURN
 142 #define NA      ORDINARY | ALPHA
 143 #define NL      NEWLINE
 144 #define NO      ORDINARY
 145 #define TB      TAB
 146 #define VT      VTAB
 147
 148 static u_char const char_type[] = {
 149         E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* nul - bel */
 150         O|BS, E|TB, E|NL, O|CC, E|VT, O|CR, O|CC, E|CC, /* bs - si */
 151         O|CC, E|CC, E|CC, O|CC, E|CC, O|CC, O|CC, E|CC, /* dle - etb */
 152         E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* can - us */
 153         O|NO, E|NO, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* sp - ' */
 154         E|NO, O|NO, O|NO, E|NO, O|NO, E|NO, E|NO, O|NO, /* ( - / */
 155         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* 0 - 7 */
 156         O|NA, E|NA, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* 8 - ? */
 157         O|NO, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* @ - G */
 158         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* H - O */
 159         E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* P - W */
 160         O|NA, E|NA, E|NA, O|NO, E|NO, O|NO, O|NO, O|NA, /* X - _ */
 161         E|NO, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* ` - g */
 162         O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* h - o */
 163         O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* p - w */
 164         E|NA, O|NA, O|NA, E|NO, O|NO, E|NO, E|NO, O|CC, /* x - del */
 165         /*
 166          * Meta chars; should be settable per character set;
 167          * for now, treat them all as normal characters.
 168          */
 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         NA,   NA,   NA,   NA,   NA,   NA,   NA,   NA,
 185 };
 186 #undef  BS
 187 #undef  CC
 188 #undef  CR
 189 #undef  NA
 190 #undef  NL
 191 #undef  NO
 192 #undef  TB
 193 #undef  VT
 194
 195 /* Macros to clear/set/test flags. */
 196 #define SET(t, f)       (t) |= (f)
 197 #define CLR(t, f)       (t) &= ~(f)
 198 #define ISSET(t, f)     ((t) & (f))
 199
 200 #undef MAX_INPUT                /* XXX wrong in <sys/syslimits.h> */
 201 #define MAX_INPUT       TTYHOG  /* XXX limit is usually larger for !ICANON */
 202
 203 uint64_t tk_nin;
 204 SYSCTL_OPAQUE(_kern, OID_AUTO, tk_nin, CTLFLAG_RD, &tk_nin, sizeof(tk_nin),
 205     "LU", "TTY input statistic");
 206 uint64_t tk_nout;
 207 SYSCTL_OPAQUE(_kern, OID_AUTO, tk_nout, CTLFLAG_RD, &tk_nout, sizeof(tk_nout),
 208     "LU", "TTY output statistic");
 209 uint64_t tk_rawcc;
 210
 211 /*
 212  * list of struct tty where pstat(8) can pick it up with sysctl
 213  */
 214 static SLIST_HEAD(, tty) tty_list;
 215
 216 /*
 217  * Initial open of tty, or (re)entry to standard tty line discipline.
 218  */
 219 int
 220 ttyopen(cdev_t device, struct tty *tp)
 221 {
 222         crit_enter();
 223         tp->t_dev = device;
 224         if (!ISSET(tp->t_state, TS_ISOPEN)) {
 225                 SET(tp->t_state, TS_ISOPEN);
 226                 if (ISSET(tp->t_cflag, CLOCAL)) {
 227                         SET(tp->t_state, TS_CONNECTED);
 228                 }
 229                 bzero(&tp->t_winsize, sizeof(tp->t_winsize));
 230         }
 231         ttsetwater(tp);
 232         crit_exit();
 233         return (0);
 234 }
 235
 236 /*
 237  * Handle close() on a tty line: flush and set to initial state,
 238  * bumping generation number so that pending read/write calls
 239  * can detect recycling of the tty.
 240  *
 241  * XXX our caller should have done `spltty(); l_close(); ttyclose();'
 242  * and l_close() should have flushed, but we repeat the spltty() and
 243  * the flush in case there are buggy callers.
 244  */
 245 int
 246 ttyclose(struct tty *tp)
 247 {
 248         funsetown(tp->t_sigio);
 249         crit_enter();
 250         if (constty == tp)
 251                 constty = NULL;
 252
 253         ttyflush(tp, FREAD | FWRITE);
 254         clist_free_cblocks(&tp->t_canq);
 255         clist_free_cblocks(&tp->t_outq);
 256         clist_free_cblocks(&tp->t_rawq);
 257
 258         tp->t_gen++;
 259         tp->t_line = TTYDISC;
 260         ttyclearsession(tp);
 261         tp->t_state = 0;
 262         crit_exit();
 263         return (0);
 264 }
 265
 266 /*
 267  * Disassociate the tty from its session.  Traditionally this has only been
 268  * a half-close, meaning that the session was still allowed to point at the
 269  * tty (resulting in the tty in the ps command showing something like 'p0-'),
 270  * even though the tty is no longer pointing at the session.
 271  *
 272  * The half close seems to be useful only for 'ps' output but there is as
 273  * yet no reason to remove the feature.  The full-close code is currently
 274  * #if 0'd out.  See also sess_rele() in kern/kern_proc.c.
 275  */
 276 void
 277 ttyclearsession(struct tty *tp)
 278 {
 279         struct session *sp;
 280
 281         tp->t_pgrp = NULL;
 282         if ((sp = tp->t_session) != NULL) {
 283                 tp->t_session = NULL;
 284 #ifdef TTY_DO_FULL_CLOSE
 285                 /* FULL CLOSE (not yet) */
 286                 if (sp->s_ttyp == tp) {
 287                         sp->s_ttyp = NULL;
 288                 } else {
 289                         kprintf("ttyclearsession: warning: sp->s_ttyp != tp "
 290                                 "%p/%p\n", sp->s_ttyp, tp);
 291                 }
 292 #endif
 293         }
 294 }
 295
 296 /*
 297  * Release the tty vnode association for a session.  This is the
 298  * 'other half' of the close.  Because multiple opens of /dev/tty
 299  * only generate a single open to the actual tty, the file modes
 300  * are locked to FREAD|FWRITE.
 301  *
 302  * If dorevoke is non-zero, the session is also revoked.  We have to
 303  * close the vnode if VCTTYISOPEN is set.
 304  */
 305 void
 306 ttyclosesession(struct session *sp, int dorevoke)
 307 {
 308         struct vnode *vp;
 309
 310 retry:
 311         /*
 312          * There may not be a controlling terminal or it may have been closed
 313          * out from under us.
 314          */
 315         if ((vp = sp->s_ttyvp) == NULL)
 316                 return;
 317
 318         /*
 319          * We need a lock if we have to close or revoke.
 320          */
 321         if ((vp->v_flag & VCTTYISOPEN) || dorevoke) {
 322                 vhold(vp);
 323                 if (vn_lock(vp, LK_EXCLUSIVE|LK_RETRY)) {
 324                         vdrop(vp);
 325                         goto retry;
 326                 }
 327
 328                 /*
 329                  * Retry if the vnode was ripped out from under us
 330                  */
 331                 if (vp != sp->s_ttyvp) {
 332                         vn_unlock(vp);
 333                         vdrop(vp);
 334                         goto retry;
 335                 }
 336
 337                 /*
 338                  * Close and revoke as needed
 339                  */
 340                 sp->s_ttyvp = NULL;
 341                 if (vp->v_flag & VCTTYISOPEN) {
 342                         vclrflags(vp, VCTTYISOPEN);
 343                         VOP_CLOSE(vp, FREAD|FWRITE);
 344                 }
 345                 vn_unlock(vp);
 346                 if (dorevoke)
 347                         vrevoke(vp, proc0.p_ucred);
 348                 vdrop(vp);
 349         } else {
 350                 sp->s_ttyvp = NULL;
 351         }
 352         vrele(vp);
 353 }
 354
 355 #define FLUSHQ(q) {                                                     \
 356         if ((q)->c_cc)                                                  \
 357                 ndflush(q, (q)->c_cc);                                  \
 358 }
 359
 360 /* Is 'c' a line delimiter ("break" character)? */
 361 #define TTBREAKC(c, lflag)                                                      \
 362         ((c) == '\n' || (((c) == cc[VEOF] ||                            \
 363           (c) == cc[VEOL] || ((c) == cc[VEOL2] && lflag & IEXTEN)) &&   \
 364          (c) != _POSIX_VDISABLE))
 365
 366 /*
 367  * Process input of a single character received on a tty.
 368  */
 369 int
 370 ttyinput(int c, struct tty *tp)
 371 {
 372         tcflag_t iflag, lflag;
 373         cc_t *cc;
 374         int i, err;
 375
 376         /*
 377          * If input is pending take it first.
 378          */
 379         lflag = tp->t_lflag;
 380         if (ISSET(lflag, PENDIN))
 381                 ttypend(tp);
 382         /*
 383          * Gather stats.
 384          */
 385         if (ISSET(lflag, ICANON))
 386                 ++tp->t_cancc;
 387         else
 388                 ++tp->t_rawcc;
 389         ++tk_nin;
 390
 391         /*
 392          * Block further input iff:
 393          * current input > threshold AND input is available to user program
 394          * AND input flow control is enabled and not yet invoked.
 395          * The 3 is slop for PARMRK.
 396          */
 397         iflag = tp->t_iflag;
 398         if (tp->t_rawq.c_cc + tp->t_canq.c_cc > tp->t_ihiwat - 3 &&
 399             (!ISSET(lflag, ICANON) || tp->t_canq.c_cc != 0) &&
 400             (ISSET(tp->t_cflag, CRTS_IFLOW) || ISSET(iflag, IXOFF)) &&
 401             !ISSET(tp->t_state, TS_TBLOCK))
 402                 ttyblock(tp);
 403
 404         /* Handle exceptional conditions (break, parity, framing). */
 405         cc = tp->t_cc;
 406         err = (ISSET(c, TTY_ERRORMASK));
 407         if (err) {
 408                 CLR(c, TTY_ERRORMASK);
 409                 if (ISSET(err, TTY_BI)) {
 410                         if (ISSET(iflag, IGNBRK))
 411                                 return (0);
 412                         if (ISSET(iflag, BRKINT)) {
 413                                 ttyflush(tp, FREAD | FWRITE);
 414                                 pgsignal(tp->t_pgrp, SIGINT, 1);
 415                                 goto endcase;
 416                         }
 417                         if (ISSET(iflag, PARMRK))
 418                                 goto parmrk;
 419                 } else if ((ISSET(err, TTY_PE) && ISSET(iflag, INPCK))
 420                         || ISSET(err, TTY_FE)) {
 421                         if (ISSET(iflag, IGNPAR))
 422                                 return (0);
 423                         else if (ISSET(iflag, PARMRK)) {
 424 parmrk:
 425                                 if (tp->t_rawq.c_cc + tp->t_canq.c_cc >
 426                                     MAX_INPUT - 3)
 427                                         goto input_overflow;
 428                                 clist_putc(0377 | TTY_QUOTE, &tp->t_rawq);
 429                                 clist_putc(0 | TTY_QUOTE, &tp->t_rawq);
 430                                 clist_putc(c | TTY_QUOTE, &tp->t_rawq);
 431                                 goto endcase;
 432                         } else
 433                                 c = 0;
 434                 }
 435         }
 436
 437         if (!ISSET(tp->t_state, TS_TYPEN) && ISSET(iflag, ISTRIP))
 438                 CLR(c, 0x80);
 439         if (!ISSET(lflag, EXTPROC)) {
 440                 /*
 441                  * Check for literal nexting very first
 442                  */
 443                 if (ISSET(tp->t_state, TS_LNCH)) {
 444                         SET(c, TTY_QUOTE);
 445                         CLR(tp->t_state, TS_LNCH);
 446                 }
 447                 /*
 448                  * Scan for special characters.  This code
 449                  * is really just a big case statement with
 450                  * non-constant cases.  The bottom of the
 451                  * case statement is labeled ``endcase'', so goto
 452                  * it after a case match, or similar.
 453                  */
 454
 455                 /*
 456                  * Control chars which aren't controlled
 457                  * by ICANON, ISIG, or IXON.
 458                  */
 459                 if (ISSET(lflag, IEXTEN)) {
 460                         if (CCEQ(cc[VLNEXT], c)) {
 461                                 if (ISSET(lflag, ECHO)) {
 462                                         if (ISSET(lflag, ECHOE)) {
 463                                                 (void)ttyoutput('^', tp);
 464                                                 (void)ttyoutput('\b', tp);
 465                                         } else
 466                                                 ttyecho(c, tp);
 467                                 }
 468                                 SET(tp->t_state, TS_LNCH);
 469                                 goto endcase;
 470                         }
 471                         if (CCEQ(cc[VDISCARD], c)) {
 472                                 if (ISSET(lflag, FLUSHO))
 473                                         CLR(tp->t_lflag, FLUSHO);
 474                                 else {
 475                                         ttyflush(tp, FWRITE);
 476                                         ttyecho(c, tp);
 477                                         if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
 478                                                 ttyretype(tp);
 479                                         SET(tp->t_lflag, FLUSHO);
 480                                 }
 481                                 goto startoutput;
 482                         }
 483                 }
 484                 /*
 485                  * Signals.
 486                  */
 487                 if (ISSET(lflag, ISIG)) {
 488                         if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
 489                                 if (!ISSET(lflag, NOFLSH))
 490                                         ttyflush(tp, FREAD | FWRITE);
 491                                 ttyecho(c, tp);
 492                                 pgsignal(tp->t_pgrp,
 493                                     CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
 494                                 goto endcase;
 495                         }
 496                         if (CCEQ(cc[VSUSP], c)) {
 497                                 if (!ISSET(lflag, NOFLSH))
 498                                         ttyflush(tp, FREAD);
 499                                 ttyecho(c, tp);
 500                                 pgsignal(tp->t_pgrp, SIGTSTP, 1);
 501                                 goto endcase;
 502                         }
 503                 }
 504                 /*
 505                  * Handle start/stop characters.
 506                  */
 507                 if (ISSET(iflag, IXON)) {
 508                         if (CCEQ(cc[VSTOP], c)) {
 509                                 if (!ISSET(tp->t_state, TS_TTSTOP)) {
 510                                         SET(tp->t_state, TS_TTSTOP);
 511                                         (*tp->t_stop)(tp, 0);
 512                                         return (0);
 513                                 }
 514                                 if (!CCEQ(cc[VSTART], c))
 515                                         return (0);
 516                                 /*
 517                                  * if VSTART == VSTOP then toggle
 518                                  */
 519                                 goto endcase;
 520                         }
 521                         if (CCEQ(cc[VSTART], c))
 522                                 goto restartoutput;
 523                 }
 524                 /*
 525                  * IGNCR, ICRNL, & INLCR
 526                  */
 527                 if (c == '\r') {
 528                         if (ISSET(iflag, IGNCR))
 529                                 return (0);
 530                         else if (ISSET(iflag, ICRNL))
 531                                 c = '\n';
 532                 } else if (c == '\n' && ISSET(iflag, INLCR))
 533                         c = '\r';
 534         }
 535         if (!ISSET(tp->t_lflag, EXTPROC) && ISSET(lflag, ICANON)) {
 536                 /*
 537                  * From here on down canonical mode character
 538                  * processing takes place.
 539                  */
 540                 /*
 541                  * erase or erase2 (^H / ^?)
 542                  */
 543                 if (CCEQ(cc[VERASE], c) || CCEQ(cc[VERASE2], c) ) {
 544                         if (tp->t_rawq.c_cc)
 545                                 ttyrub(clist_unputc(&tp->t_rawq), tp);
 546                         goto endcase;
 547                 }
 548                 /*
 549                  * kill (^U)
 550                  */
 551                 if (CCEQ(cc[VKILL], c)) {
 552                         if (ISSET(lflag, ECHOKE) &&
 553                             tp->t_rawq.c_cc == tp->t_rocount &&
 554                             !ISSET(lflag, ECHOPRT))
 555                                 while (tp->t_rawq.c_cc)
 556                                         ttyrub(clist_unputc(&tp->t_rawq), tp);
 557                         else {
 558                                 ttyecho(c, tp);
 559                                 if (ISSET(lflag, ECHOK) ||
 560                                     ISSET(lflag, ECHOKE))
 561                                         ttyecho('\n', tp);
 562                                 FLUSHQ(&tp->t_rawq);
 563                                 tp->t_rocount = 0;
 564                         }
 565                         CLR(tp->t_state, TS_LOCAL);
 566                         goto endcase;
 567                 }
 568                 /*
 569                  * word erase (^W)
 570                  */
 571                 if (CCEQ(cc[VWERASE], c) && ISSET(lflag, IEXTEN)) {
 572                         int ctype;
 573
 574                         /*
 575                          * erase whitespace
 576                          */
 577                         while ((c = clist_unputc(&tp->t_rawq)) == ' ' || c == '\t')
 578                                 ttyrub(c, tp);
 579                         if (c == -1)
 580                                 goto endcase;
 581                         /*
 582                          * erase last char of word and remember the
 583                          * next chars type (for ALTWERASE)
 584                          */
 585                         ttyrub(c, tp);
 586                         c = clist_unputc(&tp->t_rawq);
 587                         if (c == -1)
 588                                 goto endcase;
 589                         if (c == ' ' || c == '\t') {
 590                                 clist_putc(c, &tp->t_rawq);
 591                                 goto endcase;
 592                         }
 593                         ctype = ISALPHA(c);
 594                         /*
 595                          * erase rest of word
 596                          */
 597                         do {
 598                                 ttyrub(c, tp);
 599                                 c = clist_unputc(&tp->t_rawq);
 600                                 if (c == -1)
 601                                         goto endcase;
 602                         } while (c != ' ' && c != '\t' &&
 603                             (!ISSET(lflag, ALTWERASE) || ISALPHA(c) == ctype));
 604                         clist_putc(c, &tp->t_rawq);
 605                         goto endcase;
 606                 }
 607                 /*
 608                  * reprint line (^R)
 609                  */
 610                 if (CCEQ(cc[VREPRINT], c) && ISSET(lflag, IEXTEN)) {
 611                         ttyretype(tp);
 612                         goto endcase;
 613                 }
 614                 /*
 615                  * ^T - kernel info and generate SIGINFO
 616                  */
 617                 if (CCEQ(cc[VSTATUS], c) && ISSET(lflag, IEXTEN)) {
 618                         if (ISSET(lflag, ISIG))
 619                                 pgsignal(tp->t_pgrp, SIGINFO, 1);
 620                         if (!ISSET(lflag, NOKERNINFO))
 621                                 ttyinfo(tp);
 622                         goto endcase;
 623                 }
 624                 if (CCEQ(cc[VCHECKPT], c) && ISSET(lflag, IEXTEN)) {
 625                         if (ISSET(lflag, ISIG))
 626                                 pgsignal(tp->t_pgrp, SIGCKPT, 1);
 627                         goto endcase;
 628                 }
 629         }
 630         /*
 631          * Check for input buffer overflow
 632          */
 633         if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= MAX_INPUT) {
 634 input_overflow:
 635                 if (ISSET(iflag, IMAXBEL)) {
 636                         if (tp->t_outq.c_cc < tp->t_ohiwat)
 637                                 (void)ttyoutput(CTRL('g'), tp);
 638                 }
 639                 goto endcase;
 640         }
 641
 642         if (   c == 0377 && ISSET(iflag, PARMRK) && !ISSET(iflag, ISTRIP)
 643              && ISSET(iflag, IGNBRK|IGNPAR) != (IGNBRK|IGNPAR))
 644                 clist_putc(0377 | TTY_QUOTE, &tp->t_rawq);
 645
 646         /*
 647          * Put data char in q for user and
 648          * wakeup on seeing a line delimiter.
 649          */
 650         if (clist_putc(c, &tp->t_rawq) >= 0) {
 651                 if (!ISSET(lflag, ICANON)) {
 652                         ttwakeup(tp);
 653                         ttyecho(c, tp);
 654                         goto endcase;
 655                 }
 656                 if (TTBREAKC(c, lflag)) {
 657                         tp->t_rocount = 0;
 658                         catq(&tp->t_rawq, &tp->t_canq);
 659                         ttwakeup(tp);
 660                 } else if (tp->t_rocount++ == 0)
 661                         tp->t_rocol = tp->t_column;
 662                 if (ISSET(tp->t_state, TS_ERASE)) {
 663                         /*
 664                          * end of prterase \.../
 665                          */
 666                         CLR(tp->t_state, TS_ERASE);
 667                         (void)ttyoutput('/', tp);
 668                 }
 669                 i = tp->t_column;
 670                 ttyecho(c, tp);
 671                 if (CCEQ(cc[VEOF], c) && ISSET(lflag, ECHO)) {
 672                         /*
 673                          * Place the cursor over the '^' of the ^D.
 674                          */
 675                         i = imin(2, tp->t_column - i);
 676                         while (i > 0) {
 677                                 (void)ttyoutput('\b', tp);
 678                                 i--;
 679                         }
 680                 }
 681         }
 682 endcase:
 683         /*
 684          * IXANY means allow any character to restart output.
 685          */
 686         if (ISSET(tp->t_state, TS_TTSTOP) &&
 687             !ISSET(iflag, IXANY) && cc[VSTART] != cc[VSTOP])
 688                 return (0);
 689 restartoutput:
 690         CLR(tp->t_lflag, FLUSHO);
 691         CLR(tp->t_state, TS_TTSTOP);
 692 startoutput:
 693         return (ttstart(tp));
 694 }
 695
 696 /*
 697  * Output a single character on a tty, doing output processing
 698  * as needed (expanding tabs, newline processing, etc.).
 699  * Returns < 0 if succeeds, otherwise returns char to resend.
 700  * Must be recursive.
 701  */
 702 static int
 703 ttyoutput(int c, struct tty *tp)
 704 {
 705         tcflag_t oflag;
 706         int col;
 707
 708         oflag = tp->t_oflag;
 709         if (!ISSET(oflag, OPOST)) {
 710                 if (ISSET(tp->t_lflag, FLUSHO))
 711                         return (-1);
 712                 if (clist_putc(c, &tp->t_outq))
 713                         return (c);
 714                 tk_nout++;
 715                 tp->t_outcc++;
 716                 return (-1);
 717         }
 718         /*
 719          * Do tab expansion if OXTABS is set.  Special case if we external
 720          * processing, we don't do the tab expansion because we'll probably
 721          * get it wrong.  If tab expansion needs to be done, let it happen
 722          * externally.
 723          */
 724         CLR(c, ~TTY_CHARMASK);
 725         if (c == '\t' &&
 726             ISSET(oflag, OXTABS) && !ISSET(tp->t_lflag, EXTPROC)) {
 727                 c = 8 - (tp->t_column & 7);
 728                 if (!ISSET(tp->t_lflag, FLUSHO)) {
 729                         crit_enter();           /* Don't interrupt tabs. */
 730                         c -= b_to_q("        ", c, &tp->t_outq);
 731                         tk_nout += c;
 732                         tp->t_outcc += c;
 733                         crit_exit();
 734                 }
 735                 tp->t_column += c;
 736                 return (c ? -1 : '\t');
 737         }
 738         if (c == CEOT && ISSET(oflag, ONOEOT))
 739                 return (-1);
 740
 741         /*
 742          * Newline translation: if ONLCR is set,
 743          * translate newline into "\r\n".
 744          */
 745         if (c == '\n' && ISSET(tp->t_oflag, ONLCR)) {
 746                 tk_nout++;
 747                 tp->t_outcc++;
 748                 if (!ISSET(tp->t_lflag, FLUSHO) && clist_putc('\r', &tp->t_outq))
 749                         return (c);
 750         }
 751         /* If OCRNL is set, translate "\r" into "\n". */
 752         else if (c == '\r' && ISSET(tp->t_oflag, OCRNL))
 753                 c = '\n';
 754         /* If ONOCR is set, don't transmit CRs when on column 0. */
 755         else if (c == '\r' && ISSET(tp->t_oflag, ONOCR) && tp->t_column == 0)
 756                 return (-1);
 757
 758         tk_nout++;
 759         tp->t_outcc++;
 760         if (!ISSET(tp->t_lflag, FLUSHO) && clist_putc(c, &tp->t_outq))
 761                 return (c);
 762
 763         col = tp->t_column;
 764         switch (CCLASS(c)) {
 765         case BACKSPACE:
 766                 if (col > 0)
 767                         --col;
 768                 break;
 769         case CONTROL:
 770                 break;
 771         case NEWLINE:
 772                 if (ISSET(tp->t_oflag, ONLCR | ONLRET))
 773                         col = 0;
 774                 break;
 775         case RETURN:
 776                 col = 0;
 777                 break;
 778         case ORDINARY:
 779                 ++col;
 780                 break;
 781         case TAB:
 782                 col = (col + 8) & ~7;
 783                 break;
 784         }
 785         tp->t_column = col;
 786         return (-1);
 787 }
 788
 789 /*
 790  * Ioctls for all tty devices.  Called after line-discipline specific ioctl
 791  * has been called to do discipline-specific functions and/or reject any
 792  * of these ioctl commands.
 793  */
 794 /* ARGSUSED */
 795 int
 796 ttioctl(struct tty *tp, u_long cmd, void *data, int flag)
 797 {
 798         struct thread *td = curthread;
 799         struct lwp *lp = td->td_lwp;
 800         struct proc *p = td->td_proc;
 801         int error;
 802
 803         KKASSERT(p);
 804
 805         /* If the ioctl involves modification, hang if in the background. */
 806         switch (cmd) {
 807         case  TIOCCBRK:
 808         case  TIOCCONS:
 809         case  TIOCDRAIN:
 810         case  TIOCEXCL:
 811         case  TIOCFLUSH:
 812 #ifdef TIOCHPCL
 813         case  TIOCHPCL:
 814 #endif
 815         case  TIOCNXCL:
 816         case  TIOCSBRK:
 817         case  TIOCSCTTY:
 818         case  TIOCSDRAINWAIT:
 819         case  TIOCSETA:
 820         case  TIOCSETAF:
 821         case  TIOCSETAW:
 822         case  TIOCSETD:
 823         case  TIOCSPGRP:
 824         case  TIOCSTART:
 825         case  TIOCSTAT:
 826         case  TIOCSTI:
 827         case  TIOCSTOP:
 828         case  TIOCSWINSZ:
 829 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
 830         case  TIOCLBIC:
 831         case  TIOCLBIS:
 832         case  TIOCLSET:
 833         case  TIOCSETC:
 834         case OTIOCSETD:
 835         case  TIOCSETN:
 836         case  TIOCSETP:
 837         case  TIOCSLTC:
 838 #endif
 839                 while (isbackground(p, tp) && !(p->p_flag & P_PPWAIT) &&
 840                     !SIGISMEMBER(p->p_sigignore, SIGTTOU) &&
 841                     !SIGISMEMBER(lp->lwp_sigmask, SIGTTOU)) {
 842                         if (p->p_pgrp->pg_jobc == 0)
 843                                 return (EIO);
 844                         pgsignal(p->p_pgrp, SIGTTOU, 1);
 845                         error = ttysleep(tp, &lbolt, PCATCH, "ttybg1",
 846                                          0);
 847                         if (error)
 848                                 return (error);
 849                 }
 850                 break;
 851         }
 852
 853         switch (cmd) {                  /* Process the ioctl. */
 854         case FIOASYNC:                  /* set/clear async i/o */
 855                 crit_enter();
 856                 if (*(int *)data)
 857                         SET(tp->t_state, TS_ASYNC);
 858                 else
 859                         CLR(tp->t_state, TS_ASYNC);
 860                 crit_exit();
 861                 break;
 862         case FIONREAD:                  /* get # bytes to read */
 863                 crit_enter();
 864                 *(int *)data = ttnread(tp);
 865                 crit_exit();
 866                 break;
 867
 868         case FIOSETOWN:
 869                 /*
 870                  * Policy -- Don't allow FIOSETOWN on someone else's
 871                  *           controlling tty
 872                  */
 873                 if (tp->t_session != NULL && !isctty(p, tp))
 874                         return (ENOTTY);
 875
 876                 error = fsetown(*(int *)data, &tp->t_sigio);
 877                 if (error)
 878                         return (error);
 879                 break;
 880         case FIOGETOWN:
 881                 if (tp->t_session != NULL && !isctty(p, tp))
 882                         return (ENOTTY);
 883                 *(int *)data = fgetown(tp->t_sigio);
 884                 break;
 885
 886         case TIOCEXCL:                  /* set exclusive use of tty */
 887                 crit_enter();
 888                 SET(tp->t_state, TS_XCLUDE);
 889                 crit_exit();
 890                 break;
 891         case TIOCFLUSH: {               /* flush buffers */
 892                 int flags = *(int *)data;
 893
 894                 if (flags == 0)
 895                         flags = FREAD | FWRITE;
 896                 else
 897                         flags &= FREAD | FWRITE;
 898                 ttyflush(tp, flags);
 899                 break;
 900         }
 901         case TIOCCONS:                  /* become virtual console */
 902                 if (*(int *)data) {
 903                         if (constty && constty != tp &&
 904                             ISSET(constty->t_state, TS_CONNECTED))
 905                                 return (EBUSY);
 906 #ifndef UCONSOLE
 907                         if ((error = priv_check(td, PRIV_ROOT)) != 0)
 908                                 return (error);
 909 #endif
 910                         constty = tp;
 911                 } else if (tp == constty)
 912                         constty = NULL;
 913                 break;
 914         case TIOCDRAIN:                 /* wait till output drained */
 915                 error = ttywait(tp);
 916                 if (error)
 917                         return (error);
 918                 break;
 919         case TIOCGETA: {                /* get termios struct */
 920                 struct termios *t = (struct termios *)data;
 921
 922                 bcopy(&tp->t_termios, t, sizeof(struct termios));
 923                 break;
 924         }
 925         case TIOCGETD:                  /* get line discipline */
 926                 *(int *)data = tp->t_line;
 927                 break;
 928         case TIOCGWINSZ:                /* get window size */
 929                 *(struct winsize *)data = tp->t_winsize;
 930                 break;
 931         case TIOCGPGRP:                 /* get pgrp of tty */
 932                 if (!isctty(p, tp))
 933                         return (ENOTTY);
 934                 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
 935                 break;
 936         case TIOCGSID:                  /* get sid of tty */
 937                 if (!isctty(p, tp))
 938                         return (ENOTTY);
 939                 *(int *)data = tp->t_session->s_sid;
 940                 break;
 941 #ifdef TIOCHPCL
 942         case TIOCHPCL:                  /* hang up on last close */
 943                 crit_enter();
 944                 SET(tp->t_cflag, HUPCL);
 945                 crit_exit();
 946                 break;
 947 #endif
 948         case TIOCNXCL:                  /* reset exclusive use of tty */
 949                 crit_enter();
 950                 CLR(tp->t_state, TS_XCLUDE);
 951                 crit_exit();
 952                 break;
 953         case TIOCOUTQ:                  /* output queue size */
 954                 *(int *)data = tp->t_outq.c_cc;
 955                 break;
 956         case TIOCSETA:                  /* set termios struct */
 957         case TIOCSETAW:                 /* drain output, set */
 958         case TIOCSETAF: {               /* drn out, fls in, set */
 959                 struct termios *t = (struct termios *)data;
 960
 961                 if (t->c_ispeed == 0)
 962                         t->c_ispeed = t->c_ospeed;
 963                 if (t->c_ispeed == 0)
 964                         t->c_ispeed = tp->t_ospeed;
 965                 if (t->c_ispeed == 0)
 966                         return (EINVAL);
 967                 crit_enter();
 968                 if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
 969                         error = ttywait(tp);
 970                         if (error) {
 971                                 crit_exit();
 972                                 return (error);
 973                         }
 974                         if (cmd == TIOCSETAF)
 975                                 ttyflush(tp, FREAD);
 976                 }
 977                 if (!ISSET(t->c_cflag, CIGNORE)) {
 978                         /*
 979                          * Set device hardware.
 980                          */
 981                         if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
 982                                 crit_exit();
 983                                 return (error);
 984                         }
 985                         if (ISSET(t->c_cflag, CLOCAL) &&
 986                             !ISSET(tp->t_cflag, CLOCAL)) {
 987                                 /*
 988                                  * XXX disconnections would be too hard to
 989                                  * get rid of without this kludge.  The only
 990                                  * way to get rid of controlling terminals
 991                                  * is to exit from the session leader.
 992                                  */
 993                                 CLR(tp->t_state, TS_ZOMBIE);
 994
 995                                 wakeup(TSA_CARR_ON(tp));
 996                                 ttwakeup(tp);
 997                                 ttwwakeup(tp);
 998                         }
 999                         if ((ISSET(tp->t_state, TS_CARR_ON) ||
1000                              ISSET(t->c_cflag, CLOCAL)) &&
1001                             !ISSET(tp->t_state, TS_ZOMBIE))
1002                                 SET(tp->t_state, TS_CONNECTED);
1003                         else
1004                                 CLR(tp->t_state, TS_CONNECTED);
1005                         tp->t_cflag = t->c_cflag;
1006                         tp->t_ispeed = t->c_ispeed;
1007                         if (t->c_ospeed != 0)
1008                                 tp->t_ospeed = t->c_ospeed;
1009                         ttsetwater(tp);
1010                 }
1011                 if (ISSET(t->c_lflag, ICANON) != ISSET(tp->t_lflag, ICANON) &&
1012                     cmd != TIOCSETAF) {
1013                         if (ISSET(t->c_lflag, ICANON))
1014                                 SET(tp->t_lflag, PENDIN);
1015                         else {
1016                                 /*
1017                                  * XXX we really shouldn't allow toggling
1018                                  * ICANON while we're in a non-termios line
1019                                  * discipline.  Now we have to worry about
1020                                  * panicing for a null queue.
1021                                  */
1022                                 if (tp->t_canq.c_cbreserved > 0 &&
1023                                     tp->t_rawq.c_cbreserved > 0) {
1024                                         catq(&tp->t_rawq, &tp->t_canq);
1025                                         /*
1026                                          * XXX the queue limits may be
1027                                          * different, so the old queue
1028                                          * swapping method no longer works.
1029                                          */
1030                                         catq(&tp->t_canq, &tp->t_rawq);
1031                                 }
1032                                 CLR(tp->t_lflag, PENDIN);
1033                         }
1034                         ttwakeup(tp);
1035                 }
1036                 tp->t_iflag = t->c_iflag;
1037                 tp->t_oflag = t->c_oflag;
1038                 /*
1039                  * Make the EXTPROC bit read only.
1040                  */
1041                 if (ISSET(tp->t_lflag, EXTPROC))
1042                         SET(t->c_lflag, EXTPROC);
1043                 else
1044                         CLR(t->c_lflag, EXTPROC);
1045                 tp->t_lflag = t->c_lflag | ISSET(tp->t_lflag, PENDIN);
1046                 if (t->c_cc[VMIN] != tp->t_cc[VMIN] ||
1047                     t->c_cc[VTIME] != tp->t_cc[VTIME])
1048                         ttwakeup(tp);
1049                 bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc));
1050                 crit_exit();
1051                 break;
1052         }
1053         case TIOCSETD: {                /* set line discipline */
1054                 int t = *(int *)data;
1055                 cdev_t device = tp->t_dev;
1056
1057                 if ((u_int)t >= nlinesw)
1058                         return (ENXIO);
1059                 if (t != tp->t_line) {
1060                         crit_enter();
1061                         (*linesw[tp->t_line].l_close)(tp, flag);
1062                         error = (*linesw[t].l_open)(device, tp);
1063                         if (error) {
1064                                 (void)(*linesw[tp->t_line].l_open)(device, tp);
1065                                 crit_exit();
1066                                 return (error);
1067                         }
1068                         tp->t_line = t;
1069                         crit_exit();
1070                 }
1071                 break;
1072         }
1073         case TIOCSTART:                 /* start output, like ^Q */
1074                 crit_enter();
1075                 if (ISSET(tp->t_state, TS_TTSTOP) ||
1076                     ISSET(tp->t_lflag, FLUSHO)) {
1077                         CLR(tp->t_lflag, FLUSHO);
1078                         CLR(tp->t_state, TS_TTSTOP);
1079                         ttstart(tp);
1080                 }
1081                 crit_exit();
1082                 break;
1083         case TIOCSTI:                   /* simulate terminal input */
1084                 if ((flag & FREAD) == 0 && priv_check(td, PRIV_ROOT))
1085                         return (EPERM);
1086                 if (!isctty(p, tp) && priv_check(td, PRIV_ROOT))
1087                         return (EACCES);
1088                 crit_enter();
1089                 (*linesw[tp->t_line].l_rint)(*(u_char *)data, tp);
1090                 crit_exit();
1091                 break;
1092         case TIOCSTOP:                  /* stop output, like ^S */
1093                 crit_enter();
1094                 if (!ISSET(tp->t_state, TS_TTSTOP)) {
1095                         SET(tp->t_state, TS_TTSTOP);
1096                         (*tp->t_stop)(tp, 0);
1097                 }
1098                 crit_exit();
1099                 break;
1100         case TIOCSCTTY:                 /* become controlling tty */
1101                 /* Session ctty vnode pointer set in vnode layer. */
1102                 if (!SESS_LEADER(p) ||
1103                     ((p->p_session->s_ttyvp || tp->t_session) &&
1104                     (tp->t_session != p->p_session)))
1105                         return (EPERM);
1106                 tp->t_session = p->p_session;
1107                 tp->t_pgrp = p->p_pgrp;
1108                 p->p_session->s_ttyp = tp;
1109                 p->p_flag |= P_CONTROLT;
1110                 break;
1111         case TIOCSPGRP: {               /* set pgrp of tty */
1112                 pid_t pgid = *(int *)data;
1113
1114                 if (!isctty(p, tp))
1115                         return (ENOTTY);
1116                 else if (pgid < 1 || pgid > PID_MAX)
1117                         return (EINVAL);
1118                 else {
1119                         struct pgrp *pgrp = pgfind(pgid);
1120                         if (pgrp == NULL || pgrp->pg_session != p->p_session)
1121                                 return (EPERM);
1122
1123                         tp->t_pgrp = pgrp;
1124                 }
1125                 break;
1126         }
1127         case TIOCSTAT:                  /* simulate control-T */
1128                 crit_enter();
1129                 ttyinfo(tp);
1130                 crit_exit();
1131                 break;
1132         case TIOCSWINSZ:                /* set window size */
1133                 if (bcmp((caddr_t)&tp->t_winsize, data,
1134                     sizeof (struct winsize))) {
1135                         tp->t_winsize = *(struct winsize *)data;
1136                         pgsignal(tp->t_pgrp, SIGWINCH, 1);
1137                 }
1138                 break;
1139         case TIOCSDRAINWAIT:
1140                 error = priv_check(td, PRIV_ROOT);
1141                 if (error)
1142                         return (error);
1143                 tp->t_timeout = *(int *)data * hz;
1144                 wakeup(TSA_OCOMPLETE(tp));
1145                 wakeup(TSA_OLOWAT(tp));
1146                 break;
1147         case TIOCGDRAINWAIT:
1148                 *(int *)data = tp->t_timeout / hz;
1149                 break;
1150         default:
1151 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1152                 return (ttcompat(tp, cmd, data, flag));
1153 #else
1154                 return (ENOIOCTL);
1155 #endif
1156         }
1157         return (0);
1158 }
1159
1160 int
1161 ttypoll(struct dev_poll_args *ap)
1162 {
1163         cdev_t dev = ap->a_head.a_dev;
1164         int events = ap->a_events;
1165         int revents = 0;
1166         struct tty *tp;
1167
1168         tp = dev->si_tty;
1169         /* XXX used to return ENXIO, but that means true! */
1170         if (tp == NULL) {
1171                 ap->a_events = (events & (POLLIN | POLLOUT | POLLRDNORM |
1172                                 POLLWRNORM)) | POLLHUP;
1173                 return(0);
1174         }
1175
1176         crit_enter();
1177         if (events & (POLLIN | POLLRDNORM)) {
1178                 if (ttnread(tp) > 0 || ISSET(tp->t_state, TS_ZOMBIE))
1179                         revents |= events & (POLLIN | POLLRDNORM);
1180                 else
1181                         selrecord(curthread, &tp->t_rsel);
1182         }
1183         if (events & (POLLOUT | POLLWRNORM)) {
1184                 if ((tp->t_outq.c_cc <= tp->t_olowat &&
1185                      ISSET(tp->t_state, TS_CONNECTED))
1186                     || ISSET(tp->t_state, TS_ZOMBIE))
1187                         revents |= events & (POLLOUT | POLLWRNORM);
1188                 else
1189                         selrecord(curthread, &tp->t_wsel);
1190         }
1191         crit_exit();
1192         ap->a_events = revents;
1193         return (0);
1194 }
1195
1196 static struct filterops ttyread_filtops =
1197         { 1, NULL, filt_ttyrdetach, filt_ttyread };
1198 static struct filterops ttywrite_filtops =
1199         { 1, NULL, filt_ttywdetach, filt_ttywrite };
1200
1201 int
1202 ttykqfilter(struct dev_kqfilter_args *ap)
1203 {
1204         cdev_t dev = ap->a_head.a_dev;
1205         struct knote *kn = ap->a_kn;
1206         struct tty *tp = dev->si_tty;
1207         struct klist *klist;
1208
1209         ap->a_result = 0;
1210         switch (kn->kn_filter) {
1211         case EVFILT_READ:
1212                 klist = &tp->t_rsel.si_note;
1213                 kn->kn_fop = &ttyread_filtops;
1214                 break;
1215         case EVFILT_WRITE:
1216                 klist = &tp->t_wsel.si_note;
1217                 kn->kn_fop = &ttywrite_filtops;
1218                 break;
1219         default:
1220                 ap->a_result = 1;
1221                 return (0);
1222         }
1223
1224         kn->kn_hook = (caddr_t)dev;
1225
1226         crit_enter();
1227         SLIST_INSERT_HEAD(klist, kn, kn_selnext);
1228         crit_exit();
1229
1230         return (0);
1231 }
1232
1233 static void
1234 filt_ttyrdetach(struct knote *kn)
1235 {
1236         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1237
1238         crit_enter();
1239         SLIST_REMOVE(&tp->t_rsel.si_note, kn, knote, kn_selnext);
1240         crit_exit();
1241 }
1242
1243 static int
1244 filt_ttyread(struct knote *kn, long hint)
1245 {
1246         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1247
1248         kn->kn_data = ttnread(tp);
1249         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1250                 kn->kn_flags |= EV_EOF;
1251                 return (1);
1252         }
1253         return (kn->kn_data > 0);
1254 }
1255
1256 static void
1257 filt_ttywdetach(struct knote *kn)
1258 {
1259         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1260
1261         crit_enter();
1262         SLIST_REMOVE(&tp->t_wsel.si_note, kn, knote, kn_selnext);
1263         crit_exit();
1264 }
1265
1266 static int
1267 filt_ttywrite(struct knote *kn, long hint)
1268 {
1269         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
1270
1271         kn->kn_data = tp->t_outq.c_cc;
1272         if (ISSET(tp->t_state, TS_ZOMBIE))
1273                 return (1);
1274         return (kn->kn_data <= tp->t_olowat &&
1275             ISSET(tp->t_state, TS_CONNECTED));
1276 }
1277
1278 /*
1279  * Must be called while in a critical section.
1280  */
1281 static int
1282 ttnread(struct tty *tp)
1283 {
1284         int nread;
1285
1286         if (ISSET(tp->t_lflag, PENDIN))
1287                 ttypend(tp);
1288         nread = tp->t_canq.c_cc;
1289         if (!ISSET(tp->t_lflag, ICANON)) {
1290                 nread += tp->t_rawq.c_cc;
1291                 if (nread < tp->t_cc[VMIN] && tp->t_cc[VTIME] == 0)
1292                         nread = 0;
1293         }
1294         return (nread);
1295 }
1296
1297 /*
1298  * Wait for output to drain.
1299  */
1300 int
1301 ttywait(struct tty *tp)
1302 {
1303         int error;
1304
1305         error = 0;
1306         crit_enter();
1307         while ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
1308                ISSET(tp->t_state, TS_CONNECTED) && tp->t_oproc) {
1309                 (*tp->t_oproc)(tp);
1310                 if ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
1311                     ISSET(tp->t_state, TS_CONNECTED)) {
1312                         SET(tp->t_state, TS_SO_OCOMPLETE);
1313                         error = ttysleep(tp, TSA_OCOMPLETE(tp),
1314                                          PCATCH, "ttywai",
1315                                          tp->t_timeout);
1316                         if (error) {
1317                                 if (error == EWOULDBLOCK)
1318                                         error = EIO;
1319                                 break;
1320                         }
1321                 } else
1322                         break;
1323         }
1324         if (!error && (tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)))
1325                 error = EIO;
1326         crit_exit();
1327         return (error);
1328 }
1329
1330 /*
1331  * Flush if successfully wait.
1332  */
1333 static int
1334 ttywflush(struct tty *tp)
1335 {
1336         int error;
1337
1338         if ((error = ttywait(tp)) == 0)
1339                 ttyflush(tp, FREAD);
1340         return (error);
1341 }
1342
1343 /*
1344  * Flush tty read and/or write queues, notifying anyone waiting.
1345  */
1346 void
1347 ttyflush(struct tty *tp, int rw)
1348 {
1349         crit_enter();
1350 #if 0
1351 again:
1352 #endif
1353         if (rw & FWRITE) {
1354                 FLUSHQ(&tp->t_outq);
1355                 CLR(tp->t_state, TS_TTSTOP);
1356         }
1357         (*tp->t_stop)(tp, rw);
1358         if (rw & FREAD) {
1359                 FLUSHQ(&tp->t_canq);
1360                 FLUSHQ(&tp->t_rawq);
1361                 CLR(tp->t_lflag, PENDIN);
1362                 tp->t_rocount = 0;
1363                 tp->t_rocol = 0;
1364                 CLR(tp->t_state, TS_LOCAL);
1365                 ttwakeup(tp);
1366                 if (ISSET(tp->t_state, TS_TBLOCK)) {
1367                         if (rw & FWRITE)
1368                                 FLUSHQ(&tp->t_outq);
1369                         ttyunblock(tp);
1370
1371                         /*
1372                          * Don't let leave any state that might clobber the
1373                          * next line discipline (although we should do more
1374                          * to send the START char).  Not clearing the state
1375                          * may have caused the "putc to a clist with no
1376                          * reserved cblocks" panic/kprintf.
1377                          */
1378                         CLR(tp->t_state, TS_TBLOCK);
1379
1380 #if 0 /* forget it, sleeping isn't always safe and we don't know when it is */
1381                         if (ISSET(tp->t_iflag, IXOFF)) {
1382                                 /*
1383                                  * XXX wait a bit in the hope that the stop
1384                                  * character (if any) will go out.  Waiting
1385                                  * isn't good since it allows races.  This
1386                                  * will be fixed when the stop character is
1387                                  * put in a special queue.  Don't bother with
1388                                  * the checks in ttywait() since the timeout
1389                                  * will save us.
1390                                  */
1391                                 SET(tp->t_state, TS_SO_OCOMPLETE);
1392                                 ttysleep(tp, TSA_OCOMPLETE(tp), 0,
1393                                          "ttyfls", hz / 10);
1394                                 /*
1395                                  * Don't try sending the stop character again.
1396                                  */
1397                                 CLR(tp->t_state, TS_TBLOCK);
1398                                 goto again;
1399                         }
1400 #endif
1401                 }
1402         }
1403         if (rw & FWRITE) {
1404                 FLUSHQ(&tp->t_outq);
1405                 ttwwakeup(tp);
1406         }
1407         crit_exit();
1408 }
1409
1410 /*
1411  * Copy in the default termios characters.
1412  */
1413 void
1414 termioschars(struct termios *t)
1415 {
1416
1417         bcopy(ttydefchars, t->c_cc, sizeof t->c_cc);
1418 }
1419
1420 /*
1421  * Old interface.
1422  */
1423 void
1424 ttychars(struct tty *tp)
1425 {
1426
1427         termioschars(&tp->t_termios);
1428 }
1429
1430 /*
1431  * Handle input high water.  Send stop character for the IXOFF case.  Turn
1432  * on our input flow control bit and propagate the changes to the driver.
1433  * XXX the stop character should be put in a special high priority queue.
1434  */
1435 void
1436 ttyblock(struct tty *tp)
1437 {
1438
1439         SET(tp->t_state, TS_TBLOCK);
1440         if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTOP] != _POSIX_VDISABLE &&
1441             clist_putc(tp->t_cc[VSTOP], &tp->t_outq) != 0)
1442                 CLR(tp->t_state, TS_TBLOCK);    /* try again later */
1443         ttstart(tp);
1444 }
1445
1446 /*
1447  * Handle input low water.  Send start character for the IXOFF case.  Turn
1448  * off our input flow control bit and propagate the changes to the driver.
1449  * XXX the start character should be put in a special high priority queue.
1450  */
1451 static void
1452 ttyunblock(struct tty *tp)
1453 {
1454
1455         CLR(tp->t_state, TS_TBLOCK);
1456         if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTART] != _POSIX_VDISABLE &&
1457             clist_putc(tp->t_cc[VSTART], &tp->t_outq) != 0)
1458                 SET(tp->t_state, TS_TBLOCK);    /* try again later */
1459         ttstart(tp);
1460 }
1461
1462 #ifdef notyet
1463 /* Not used by any current (i386) drivers. */
1464 /*
1465  * Restart after an inter-char delay.
1466  */
1467 void
1468 ttrstrt(void *tp_arg)
1469 {
1470         struct tty *tp;
1471
1472         KASSERT(tp_arg != NULL, ("ttrstrt"));
1473
1474         tp = tp_arg;
1475         crit_enter();
1476         CLR(tp->t_state, TS_TIMEOUT);
1477         ttstart(tp);
1478         crit_exit();
1479 }
1480 #endif
1481
1482 int
1483 ttstart(struct tty *tp)
1484 {
1485
1486         if (tp->t_oproc != NULL)        /* XXX: Kludge for pty. */
1487                 (*tp->t_oproc)(tp);
1488         return (0);
1489 }
1490
1491 /*
1492  * "close" a line discipline
1493  */
1494 int
1495 ttylclose(struct tty *tp, int flag)
1496 {
1497
1498         if (flag & FNONBLOCK || ttywflush(tp))
1499                 ttyflush(tp, FREAD | FWRITE);
1500         return (0);
1501 }
1502
1503 /*
1504  * Handle modem control transition on a tty.
1505  * Flag indicates new state of carrier.
1506  * Returns 0 if the line should be turned off, otherwise 1.
1507  */
1508 int
1509 ttymodem(struct tty *tp, int flag)
1510 {
1511
1512         if (ISSET(tp->t_state, TS_CARR_ON) && ISSET(tp->t_cflag, MDMBUF)) {
1513                 /*
1514                  * MDMBUF: do flow control according to carrier flag
1515                  * XXX TS_CAR_OFLOW doesn't do anything yet.  TS_TTSTOP
1516                  * works if IXON and IXANY are clear.
1517                  */
1518                 if (flag) {
1519                         CLR(tp->t_state, TS_CAR_OFLOW);
1520                         CLR(tp->t_state, TS_TTSTOP);
1521                         ttstart(tp);
1522                 } else if (!ISSET(tp->t_state, TS_CAR_OFLOW)) {
1523                         SET(tp->t_state, TS_CAR_OFLOW);
1524                         SET(tp->t_state, TS_TTSTOP);
1525                         (*tp->t_stop)(tp, 0);
1526                 }
1527         } else if (flag == 0) {
1528                 /*
1529                  * Lost carrier.
1530                  */
1531                 CLR(tp->t_state, TS_CARR_ON);
1532                 if (ISSET(tp->t_state, TS_ISOPEN) &&
1533                     !ISSET(tp->t_cflag, CLOCAL)) {
1534                         SET(tp->t_state, TS_ZOMBIE);
1535                         CLR(tp->t_state, TS_CONNECTED);
1536                         if (tp->t_session && tp->t_session->s_leader)
1537                                 ksignal(tp->t_session->s_leader, SIGHUP);
1538                         ttyflush(tp, FREAD | FWRITE);
1539                         return (0);
1540                 }
1541         } else {
1542                 /*
1543                  * Carrier now on.
1544                  */
1545                 SET(tp->t_state, TS_CARR_ON);
1546                 if (!ISSET(tp->t_state, TS_ZOMBIE))
1547                         SET(tp->t_state, TS_CONNECTED);
1548                 wakeup(TSA_CARR_ON(tp));
1549                 ttwakeup(tp);
1550                 ttwwakeup(tp);
1551         }
1552         return (1);
1553 }
1554
1555 /*
1556  * Reinput pending characters after state switch
1557  * call from a critical section.
1558  */
1559 static void
1560 ttypend(struct tty *tp)
1561 {
1562         struct clist tq;
1563         int c;
1564
1565         CLR(tp->t_lflag, PENDIN);
1566         SET(tp->t_state, TS_TYPEN);
1567         /*
1568          * XXX this assumes too much about clist internals.  It may even
1569          * fail if the cblock slush pool is empty.  We can't allocate more
1570          * cblocks here because we are called from an interrupt handler
1571          * and clist_alloc_cblocks() can wait.
1572          */
1573         tq = tp->t_rawq;
1574         bzero(&tp->t_rawq, sizeof tp->t_rawq);
1575         tp->t_rawq.c_cbmax = tq.c_cbmax;
1576         tp->t_rawq.c_cbreserved = tq.c_cbreserved;
1577         while ((c = clist_getc(&tq)) >= 0)
1578                 ttyinput(c, tp);
1579         CLR(tp->t_state, TS_TYPEN);
1580 }
1581
1582 /*
1583  * Process a read call on a tty device.
1584  */
1585 int
1586 ttread(struct tty *tp, struct uio *uio, int flag)
1587 {
1588         struct clist *qp;
1589         int c;
1590         tcflag_t lflag;
1591         cc_t *cc = tp->t_cc;
1592         struct proc *pp;
1593         struct lwp *lp;
1594         int first, error = 0;
1595         int has_stime = 0, last_cc = 0;
1596         long slp = 0;           /* XXX this should be renamed `timo'. */
1597         struct timeval stime;
1598
1599         lp = curthread->td_lwp;
1600         stime.tv_sec = 0;       /* fix compiler warnings */
1601         stime.tv_usec = 0;
1602
1603 loop:
1604         crit_enter();
1605         lflag = tp->t_lflag;
1606         /*
1607          * take pending input first
1608          */
1609         if (ISSET(lflag, PENDIN)) {
1610                 ttypend(tp);
1611                 splz();         /* reduce latency */
1612                 lflag = tp->t_lflag;    /* XXX ttypend() clobbers it */
1613         }
1614
1615         /*
1616          * Hang process if it's in the background.
1617          */
1618         if ((pp = curproc) && isbackground(pp, tp)) {
1619                 crit_exit();
1620                 if (SIGISMEMBER(pp->p_sigignore, SIGTTIN) ||
1621                     SIGISMEMBER(lp->lwp_sigmask, SIGTTIN) ||
1622                     (pp->p_flag & P_PPWAIT) || pp->p_pgrp->pg_jobc == 0)
1623                         return (EIO);
1624                 pgsignal(pp->p_pgrp, SIGTTIN, 1);
1625                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg2", 0);
1626                 if (error)
1627                         return (error);
1628                 goto loop;
1629         }
1630
1631         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1632                 crit_exit();
1633                 return (0);     /* EOF */
1634         }
1635
1636         /*
1637          * If canonical, use the canonical queue,
1638          * else use the raw queue.
1639          *
1640          * (should get rid of clists...)
1641          */
1642         qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq;
1643
1644         if (flag & IO_NDELAY) {
1645                 if (qp->c_cc > 0)
1646                         goto read;
1647                 if (!ISSET(lflag, ICANON) && cc[VMIN] == 0) {
1648                         crit_exit();
1649                         return (0);
1650                 }
1651                 crit_exit();
1652                 return (EWOULDBLOCK);
1653         }
1654         if (!ISSET(lflag, ICANON)) {
1655                 int m = cc[VMIN];
1656                 long t = cc[VTIME];
1657                 struct timeval timecopy;
1658
1659                 /*
1660                  * Check each of the four combinations.
1661                  * (m > 0 && t == 0) is the normal read case.
1662                  * It should be fairly efficient, so we check that and its
1663                  * companion case (m == 0 && t == 0) first.
1664                  * For the other two cases, we compute the target sleep time
1665                  * into slp.
1666                  */
1667                 if (t == 0) {
1668                         if (qp->c_cc < m)
1669                                 goto sleep;
1670                         if (qp->c_cc > 0)
1671                                 goto read;
1672
1673                         /* m, t and qp->c_cc are all 0.  0 is enough input. */
1674                         crit_exit();
1675                         return (0);
1676                 }
1677                 t *= 100000;            /* time in us */
1678 #define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 1000000 + \
1679                          ((t1).tv_usec - (t2).tv_usec))
1680                 if (m > 0) {
1681                         if (qp->c_cc <= 0)
1682                                 goto sleep;
1683                         if (qp->c_cc >= m)
1684                                 goto read;
1685                         getmicrotime(&timecopy);
1686                         if (has_stime == 0) {
1687                                 /* first character, start timer */
1688                                 has_stime = 1;
1689                                 stime = timecopy;
1690                                 slp = t;
1691                         } else if (qp->c_cc > last_cc) {
1692                                 /* got a character, restart timer */
1693                                 stime = timecopy;
1694                                 slp = t;
1695                         } else {
1696                                 /* nothing, check expiration */
1697                                 slp = t - diff(timecopy, stime);
1698                                 if (slp <= 0)
1699                                         goto read;
1700                         }
1701                         last_cc = qp->c_cc;
1702                 } else {        /* m == 0 */
1703                         if (qp->c_cc > 0)
1704                                 goto read;
1705                         getmicrotime(&timecopy);
1706                         if (has_stime == 0) {
1707                                 has_stime = 1;
1708                                 stime = timecopy;
1709                                 slp = t;
1710                         } else {
1711                                 slp = t - diff(timecopy, stime);
1712                                 if (slp <= 0) {
1713                                         /* Timed out, but 0 is enough input. */
1714                                         crit_exit();
1715                                         return (0);
1716                                 }
1717                         }
1718                 }
1719 #undef diff
1720                 /*
1721                  * Rounding down may make us wake up just short
1722                  * of the target, so we round up.
1723                  * The formula is ceiling(slp * hz/1000000).
1724                  * 32-bit arithmetic is enough for hz < 169.
1725                  * XXX see tvtohz() for how to avoid overflow if hz
1726                  * is large (divide by `tick' and/or arrange to
1727                  * use tvtohz() if hz is large).
1728                  */
1729                 slp = (long) (((u_long)slp * hz) + 999999) / 1000000;
1730                 goto sleep;
1731         }
1732         if (qp->c_cc <= 0) {
1733 sleep:
1734                 /*
1735                  * There is no input, or not enough input and we can block.
1736                  */
1737                 error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), PCATCH,
1738                                  ISSET(tp->t_state, TS_CONNECTED) ?
1739                                  "ttyin" : "ttyhup", (int)slp);
1740                 crit_exit();
1741                 if (error == EWOULDBLOCK)
1742                         error = 0;
1743                 else if (error)
1744                         return (error);
1745                 /*
1746                  * XXX what happens if another process eats some input
1747                  * while we are asleep (not just here)?  It would be
1748                  * safest to detect changes and reset our state variables
1749                  * (has_stime and last_cc).
1750                  */
1751                 slp = 0;
1752                 goto loop;
1753         }
1754 read:
1755         crit_exit();
1756         /*
1757          * Input present, check for input mapping and processing.
1758          */
1759         first = 1;
1760         if (ISSET(lflag, ICANON | ISIG))
1761                 goto slowcase;
1762         for (;;) {
1763                 char ibuf[IBUFSIZ];
1764                 int icc;
1765
1766                 icc = (int)szmin(uio->uio_resid, IBUFSIZ);
1767                 icc = q_to_b(qp, ibuf, icc);
1768                 if (icc <= 0) {
1769                         if (first)
1770                                 goto loop;
1771                         break;
1772                 }
1773                 error = uiomove(ibuf, (size_t)icc, uio);
1774                 /*
1775                  * XXX if there was an error then we should ungetc() the
1776                  * unmoved chars and reduce icc here.
1777                  */
1778                 if (error)
1779                         break;
1780                 if (uio->uio_resid == 0)
1781                         break;
1782                 first = 0;
1783         }
1784         goto out;
1785 slowcase:
1786         for (;;) {
1787                 c = clist_getc(qp);
1788                 if (c < 0) {
1789                         if (first)
1790                                 goto loop;
1791                         break;
1792                 }
1793                 /*
1794                  * delayed suspend (^Y)
1795                  */
1796                 if (CCEQ(cc[VDSUSP], c) &&
1797                     ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) {
1798                         pgsignal(tp->t_pgrp, SIGTSTP, 1);
1799                         if (first) {
1800                                 error = ttysleep(tp, &lbolt, PCATCH,
1801                                                  "ttybg3", 0);
1802                                 if (error)
1803                                         break;
1804                                 goto loop;
1805                         }
1806                         break;
1807                 }
1808                 /*
1809                  * Interpret EOF only in canonical mode.
1810                  */
1811                 if (CCEQ(cc[VEOF], c) && ISSET(lflag, ICANON))
1812                         break;
1813                 /*
1814                  * Give user character.
1815                  */
1816                 error = ureadc(c, uio);
1817                 if (error)
1818                         /* XXX should ungetc(c, qp). */
1819                         break;
1820                 if (uio->uio_resid == 0)
1821                         break;
1822                 /*
1823                  * In canonical mode check for a "break character"
1824                  * marking the end of a "line of input".
1825                  */
1826                 if (ISSET(lflag, ICANON) && TTBREAKC(c, lflag))
1827                         break;
1828                 first = 0;
1829         }
1830
1831 out:
1832         /*
1833          * Look to unblock input now that (presumably)
1834          * the input queue has gone down.
1835          */
1836         crit_enter();
1837         if (ISSET(tp->t_state, TS_TBLOCK) &&
1838             tp->t_rawq.c_cc + tp->t_canq.c_cc <= tp->t_ilowat)
1839                 ttyunblock(tp);
1840         crit_exit();
1841
1842         return (error);
1843 }
1844
1845 /*
1846  * Check the output queue on tp for space for a kernel message (from uprintf
1847  * or tprintf).  Allow some space over the normal hiwater mark so we don't
1848  * lose messages due to normal flow control, but don't let the tty run amok.
1849  * Sleeps here are not interruptible, but we return prematurely if new signals
1850  * arrive.
1851  */
1852 int
1853 ttycheckoutq(struct tty *tp, int wait)
1854 {
1855         struct lwp *lp = curthread->td_lwp;
1856         int hiwat;
1857         sigset_t oldset, newset;
1858
1859         hiwat = tp->t_ohiwat;
1860         SIGEMPTYSET(oldset);
1861         SIGEMPTYSET(newset);
1862         crit_enter();
1863         if (wait)
1864                 oldset = lwp_sigpend(lp);
1865         if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100) {
1866                 while (tp->t_outq.c_cc > hiwat) {
1867                         ttstart(tp);
1868                         if (tp->t_outq.c_cc <= hiwat)
1869                                 break;
1870                         if (wait)
1871                                 newset = lwp_sigpend(lp);
1872                         if (!wait || SIGSETNEQ(oldset, newset)) {
1873                                 crit_exit();
1874                                 return (0);
1875                         }
1876                         SET(tp->t_state, TS_SO_OLOWAT);
1877                         tsleep(TSA_OLOWAT(tp), 0, "ttoutq", hz);
1878                 }
1879         }
1880         crit_exit();
1881         return (1);
1882 }
1883
1884 /*
1885  * Process a write call on a tty device.
1886  */
1887 int
1888 ttwrite(struct tty *tp, struct uio *uio, int flag)
1889 {
1890         char *cp = NULL;
1891         int cc, ce;
1892         struct proc *pp;
1893         struct lwp *lp;
1894         int i, hiwat, error;
1895         size_t cnt;
1896
1897         char obuf[OBUFSIZ];
1898
1899         lp = curthread->td_lwp;
1900         hiwat = tp->t_ohiwat;
1901         cnt = uio->uio_resid;
1902         error = 0;
1903         cc = 0;
1904 loop:
1905         crit_enter();
1906         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1907                 crit_exit();
1908                 if (uio->uio_resid == cnt)
1909                         error = EIO;
1910                 goto out;
1911         }
1912         if (!ISSET(tp->t_state, TS_CONNECTED)) {
1913                 if (flag & IO_NDELAY) {
1914                         crit_exit();
1915                         error = EWOULDBLOCK;
1916                         goto out;
1917                 }
1918                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ttydcd", 0);
1919                 crit_exit();
1920                 if (error)
1921                         goto out;
1922                 goto loop;
1923         }
1924         crit_exit();
1925
1926         /*
1927          * Hang the process if it's in the background.
1928          */
1929         if ((pp = curproc) && isbackground(pp, tp) &&
1930             ISSET(tp->t_lflag, TOSTOP) && !(pp->p_flag & P_PPWAIT) &&
1931             !SIGISMEMBER(pp->p_sigignore, SIGTTOU) &&
1932             !SIGISMEMBER(lp->lwp_sigmask, SIGTTOU)) {
1933                 if (pp->p_pgrp->pg_jobc == 0) {
1934                         error = EIO;
1935                         goto out;
1936                 }
1937                 pgsignal(pp->p_pgrp, SIGTTOU, 1);
1938                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg4", 0);
1939                 if (error)
1940                         goto out;
1941                 goto loop;
1942         }
1943         /*
1944          * Process the user's data in at most OBUFSIZ chunks.  Perform any
1945          * output translation.  Keep track of high water mark, sleep on
1946          * overflow awaiting device aid in acquiring new space.
1947          */
1948         while (uio->uio_resid > 0 || cc > 0) {
1949                 if (ISSET(tp->t_lflag, FLUSHO)) {
1950                         uio->uio_resid = 0;
1951                         return (0);
1952                 }
1953                 if (tp->t_outq.c_cc > hiwat)
1954                         goto ovhiwat;
1955                 /*
1956                  * Grab a hunk of data from the user, unless we have some
1957                  * leftover from last time.
1958                  */
1959                 if (cc == 0) {
1960                         cc = szmin(uio->uio_resid, OBUFSIZ);
1961                         cp = obuf;
1962                         error = uiomove(cp, (size_t)cc, uio);
1963                         if (error) {
1964                                 cc = 0;
1965                                 break;
1966                         }
1967                 }
1968                 /*
1969                  * If nothing fancy need be done, grab those characters we
1970                  * can handle without any of ttyoutput's processing and
1971                  * just transfer them to the output q.  For those chars
1972                  * which require special processing (as indicated by the
1973                  * bits in char_type), call ttyoutput.  After processing
1974                  * a hunk of data, look for FLUSHO so ^O's will take effect
1975                  * immediately.
1976                  */
1977                 while (cc > 0) {
1978                         if (!ISSET(tp->t_oflag, OPOST))
1979                                 ce = cc;
1980                         else {
1981                                 ce = cc - scanc((u_int)cc, (u_char *)cp,
1982                                                 char_type, CCLASSMASK);
1983                                 /*
1984                                  * If ce is zero, then we're processing
1985                                  * a special character through ttyoutput.
1986                                  */
1987                                 if (ce == 0) {
1988                                         tp->t_rocount = 0;
1989                                         if (ttyoutput(*cp, tp) >= 0) {
1990                                                 /* No Clists, wait a bit. */
1991                                                 ttstart(tp);
1992                                                 if (flag & IO_NDELAY) {
1993                                                         error = EWOULDBLOCK;
1994                                                         goto out;
1995                                                 }
1996                                                 error = ttysleep(tp, &lbolt,
1997                                                                  PCATCH,
1998                                                                  "ttybf1", 0);
1999                                                 if (error)
2000                                                         goto out;
2001                                                 goto loop;
2002                                         }
2003                                         cp++;
2004                                         cc--;
2005                                         if (ISSET(tp->t_lflag, FLUSHO) ||
2006                                             tp->t_outq.c_cc > hiwat)
2007                                                 goto ovhiwat;
2008                                         continue;
2009                                 }
2010                         }
2011                         /*
2012                          * A bunch of normal characters have been found.
2013                          * Transfer them en masse to the output queue and
2014                          * continue processing at the top of the loop.
2015                          * If there are any further characters in this
2016                          * <= OBUFSIZ chunk, the first should be a character
2017                          * requiring special handling by ttyoutput.
2018                          */
2019                         tp->t_rocount = 0;
2020                         i = b_to_q(cp, ce, &tp->t_outq);
2021                         ce -= i;
2022                         tp->t_column += ce;
2023                         cp += ce, cc -= ce, tk_nout += ce;
2024                         tp->t_outcc += ce;
2025                         if (i > 0) {
2026                                 /* No Clists, wait a bit. */
2027                                 ttstart(tp);
2028                                 if (flag & IO_NDELAY) {
2029                                         error = EWOULDBLOCK;
2030                                         goto out;
2031                                 }
2032                                 error = ttysleep(tp, &lbolt, PCATCH,
2033                                                  "ttybf2", 0);
2034                                 if (error)
2035                                         goto out;
2036                                 goto loop;
2037                         }
2038                         if (ISSET(tp->t_lflag, FLUSHO) ||
2039                             tp->t_outq.c_cc > hiwat)
2040                                 break;
2041                 }
2042                 ttstart(tp);
2043         }
2044 out:
2045         /*
2046          * If cc is nonzero, we leave the uio structure inconsistent, as the
2047          * offset and iov pointers have moved forward, but it doesn't matter
2048          * (the call will either return short or restart with a new uio).
2049          */
2050         uio->uio_resid += cc;
2051         return (error);
2052
2053 ovhiwat:
2054         ttstart(tp);
2055         crit_enter();
2056         /*
2057          * This can only occur if FLUSHO is set in t_lflag,
2058          * or if ttstart/oproc is synchronous (or very fast).
2059          */
2060         if (tp->t_outq.c_cc <= hiwat) {
2061                 crit_exit();
2062                 goto loop;
2063         }
2064         if (flag & IO_NDELAY) {
2065                 crit_exit();
2066                 uio->uio_resid += cc;
2067                 return (uio->uio_resid == cnt ? EWOULDBLOCK : 0);
2068         }
2069         SET(tp->t_state, TS_SO_OLOWAT);
2070         error = ttysleep(tp, TSA_OLOWAT(tp), PCATCH, "ttywri", tp->t_timeout);
2071         crit_exit();
2072         if (error == EWOULDBLOCK)
2073                 error = EIO;
2074         if (error)
2075                 goto out;
2076         goto loop;
2077 }
2078
2079 /*
2080  * Rubout one character from the rawq of tp
2081  * as cleanly as possible.
2082  */
2083 static void
2084 ttyrub(int c, struct tty *tp)
2085 {
2086         char *cp;
2087         int savecol;
2088         int tabc;
2089
2090         if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC))
2091                 return;
2092         CLR(tp->t_lflag, FLUSHO);
2093         if (ISSET(tp->t_lflag, ECHOE)) {
2094                 if (tp->t_rocount == 0) {
2095                         /*
2096                          * Screwed by ttwrite; retype
2097                          */
2098                         ttyretype(tp);
2099                         return;
2100                 }
2101                 if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE))
2102                         ttyrubo(tp, 2);
2103                 else {
2104                         CLR(c, ~TTY_CHARMASK);
2105                         switch (CCLASS(c)) {
2106                         case ORDINARY:
2107                                 ttyrubo(tp, 1);
2108                                 break;
2109                         case BACKSPACE:
2110                         case CONTROL:
2111                         case NEWLINE:
2112                         case RETURN:
2113                         case VTAB:
2114                                 if (ISSET(tp->t_lflag, ECHOCTL))
2115                                         ttyrubo(tp, 2);
2116                                 break;
2117                         case TAB:
2118                                 if (tp->t_rocount < tp->t_rawq.c_cc) {
2119                                         ttyretype(tp);
2120                                         return;
2121                                 }
2122                                 crit_enter();
2123                                 savecol = tp->t_column;
2124                                 SET(tp->t_state, TS_CNTTB);
2125                                 SET(tp->t_lflag, FLUSHO);
2126                                 tp->t_column = tp->t_rocol;
2127                                 cp = tp->t_rawq.c_cf;
2128                                 if (cp)
2129                                         tabc = *cp;     /* XXX FIX NEXTC */
2130                                 for (; cp; cp = nextc(&tp->t_rawq, cp, &tabc))
2131                                         ttyecho(tabc, tp);
2132                                 CLR(tp->t_lflag, FLUSHO);
2133                                 CLR(tp->t_state, TS_CNTTB);
2134                                 crit_exit();
2135
2136                                 /* savecol will now be length of the tab. */
2137                                 savecol -= tp->t_column;
2138                                 tp->t_column += savecol;
2139                                 if (savecol > 8)
2140                                         savecol = 8;    /* overflow screw */
2141                                 while (--savecol >= 0)
2142                                         (void)ttyoutput('\b', tp);
2143                                 break;
2144                         default:                        /* XXX */
2145 #define PANICSTR        "ttyrub: would panic c = %d, val = %d\n"
2146                                 (void)kprintf(PANICSTR, c, CCLASS(c));
2147 #ifdef notdef
2148                                 panic(PANICSTR, c, CCLASS(c));
2149 #endif
2150                         }
2151                 }
2152         } else if (ISSET(tp->t_lflag, ECHOPRT)) {
2153                 if (!ISSET(tp->t_state, TS_ERASE)) {
2154                         SET(tp->t_state, TS_ERASE);
2155                         (void)ttyoutput('\\', tp);
2156                 }
2157                 ttyecho(c, tp);
2158         } else {
2159                 ttyecho(tp->t_cc[VERASE], tp);
2160                 /*
2161                  * This code may be executed not only when an ERASE key
2162                  * is pressed, but also when ^U (KILL) or ^W (WERASE) are.
2163                  * So, I didn't think it was worthwhile to pass the extra
2164                  * information (which would need an extra parameter,
2165                  * changing every call) needed to distinguish the ERASE2
2166                  * case from the ERASE.
2167                  */
2168         }
2169         --tp->t_rocount;
2170 }
2171
2172 /*
2173  * Back over cnt characters, erasing them.
2174  */
2175 static void
2176 ttyrubo(struct tty *tp, int cnt)
2177 {
2178
2179         while (cnt-- > 0) {
2180                 (void)ttyoutput('\b', tp);
2181                 (void)ttyoutput(' ', tp);
2182                 (void)ttyoutput('\b', tp);
2183         }
2184 }
2185
2186 /*
2187  * ttyretype --
2188  *      Reprint the rawq line.  Note, it is assumed that c_cc has already
2189  *      been checked.
2190  */
2191 static void
2192 ttyretype(struct tty *tp)
2193 {
2194         char *cp;
2195         int c;
2196
2197         /* Echo the reprint character. */
2198         if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
2199                 ttyecho(tp->t_cc[VREPRINT], tp);
2200
2201         (void)ttyoutput('\n', tp);
2202
2203         /*
2204          * XXX
2205          * FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE
2206          * BIT OF FIRST CHAR.
2207          */
2208         crit_enter();
2209         for (cp = tp->t_canq.c_cf, c = (cp != NULL ? *cp : 0);
2210             cp != NULL; cp = nextc(&tp->t_canq, cp, &c))
2211                 ttyecho(c, tp);
2212         for (cp = tp->t_rawq.c_cf, c = (cp != NULL ? *cp : 0);
2213             cp != NULL; cp = nextc(&tp->t_rawq, cp, &c))
2214                 ttyecho(c, tp);
2215         CLR(tp->t_state, TS_ERASE);
2216         crit_exit();
2217
2218         tp->t_rocount = tp->t_rawq.c_cc;
2219         tp->t_rocol = 0;
2220 }
2221
2222 /*
2223  * Echo a typed character to the terminal.
2224  */
2225 static void
2226 ttyecho(int c, struct tty *tp)
2227 {
2228
2229         if (!ISSET(tp->t_state, TS_CNTTB))
2230                 CLR(tp->t_lflag, FLUSHO);
2231         if ((!ISSET(tp->t_lflag, ECHO) &&
2232              (c != '\n' || !ISSET(tp->t_lflag, ECHONL))) ||
2233             ISSET(tp->t_lflag, EXTPROC))
2234                 return;
2235         if (ISSET(tp->t_lflag, ECHOCTL) &&
2236             ((ISSET(c, TTY_CHARMASK) <= 037 && c != '\t' && c != '\n') ||
2237             ISSET(c, TTY_CHARMASK) == 0177)) {
2238                 (void)ttyoutput('^', tp);
2239                 CLR(c, ~TTY_CHARMASK);
2240                 if (c == 0177)
2241                         c = '?';
2242                 else
2243                         c += 'A' - 1;
2244         }
2245         (void)ttyoutput(c, tp);
2246 }
2247
2248 /*
2249  * Wake up any readers on a tty.
2250  */
2251 void
2252 ttwakeup(struct tty *tp)
2253 {
2254
2255         if (tp->t_rsel.si_pid != 0)
2256                 selwakeup(&tp->t_rsel);
2257         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2258                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2259         wakeup(TSA_HUP_OR_INPUT(tp));
2260         KNOTE(&tp->t_rsel.si_note, 0);
2261 }
2262
2263 /*
2264  * Wake up any writers on a tty.
2265  */
2266 void
2267 ttwwakeup(struct tty *tp)
2268 {
2269
2270         if (tp->t_wsel.si_pid != 0 && tp->t_outq.c_cc <= tp->t_olowat)
2271                 selwakeup(&tp->t_wsel);
2272         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2273                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2274         if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
2275             TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
2276                 CLR(tp->t_state, TS_SO_OCOMPLETE);
2277                 wakeup(TSA_OCOMPLETE(tp));
2278         }
2279         if (ISSET(tp->t_state, TS_SO_OLOWAT) &&
2280             tp->t_outq.c_cc <= tp->t_olowat) {
2281                 CLR(tp->t_state, TS_SO_OLOWAT);
2282                 wakeup(TSA_OLOWAT(tp));
2283         }
2284         KNOTE(&tp->t_wsel.si_note, 0);
2285 }
2286
2287 /*
2288  * Look up a code for a specified speed in a conversion table;
2289  * used by drivers to map software speed values to hardware parameters.
2290  */
2291 int
2292 ttspeedtab(int speed, struct speedtab *table)
2293 {
2294
2295         for ( ; table->sp_speed != -1; table++)
2296                 if (table->sp_speed == speed)
2297                         return (table->sp_code);
2298         return (-1);
2299 }
2300
2301 /*
2302  * Set input and output watermarks and buffer sizes.  For input, the
2303  * high watermark is about one second's worth of input above empty, the
2304  * low watermark is slightly below high water, and the buffer size is a
2305  * driver-dependent amount above high water.  For output, the watermarks
2306  * are near the ends of the buffer, with about 1 second's worth of input
2307  * between them.  All this only applies to the standard line discipline.
2308  */
2309 void
2310 ttsetwater(struct tty *tp)
2311 {
2312         int cps, ttmaxhiwat, x;
2313
2314         /* Input. */
2315         clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
2316         switch (tp->t_ispeedwat) {
2317         case (speed_t)-1:
2318                 cps = tp->t_ispeed / 10;
2319                 break;
2320         case 0:
2321                 /*
2322                  * This case is for old drivers that don't know about
2323                  * t_ispeedwat.  Arrange for them to get the old buffer
2324                  * sizes and watermarks.
2325                  */
2326                 cps = TTYHOG - 2 * 256;
2327                 tp->t_ififosize = 2 * 2048;
2328                 break;
2329         default:
2330                 cps = tp->t_ispeedwat / 10;
2331                 break;
2332         }
2333         tp->t_ihiwat = cps;
2334         tp->t_ilowat = 7 * cps / 8;
2335         x = cps + tp->t_ififosize;
2336         clist_alloc_cblocks(&tp->t_rawq, x, x);
2337
2338         /* Output. */
2339         switch (tp->t_ospeedwat) {
2340         case (speed_t)-1:
2341                 cps = tp->t_ospeed / 10;
2342                 ttmaxhiwat = 2 * TTMAXHIWAT;
2343                 break;
2344         case 0:
2345                 cps = tp->t_ospeed / 10;
2346                 ttmaxhiwat = TTMAXHIWAT;
2347                 break;
2348         default:
2349                 cps = tp->t_ospeedwat / 10;
2350                 ttmaxhiwat = 8 * TTMAXHIWAT;
2351                 break;
2352         }
2353 #define CLAMP(x, h, l)  ((x) > h ? h : ((x) < l) ? l : (x))
2354         tp->t_olowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
2355         x += cps;
2356         x = CLAMP(x, ttmaxhiwat, TTMINHIWAT);   /* XXX clamps are too magic */
2357         tp->t_ohiwat = roundup(x, CBSIZE);      /* XXX for compat */
2358         x = imax(tp->t_ohiwat, TTMAXHIWAT);     /* XXX for compat/safety */
2359         x += OBUFSIZ + 100;
2360         clist_alloc_cblocks(&tp->t_outq, x, x);
2361 #undef  CLAMP
2362 }
2363
2364 /*
2365  * Report on state of foreground process group.
2366  */
2367 void
2368 ttyinfo(struct tty *tp)
2369 {
2370         struct proc *p, *pick;
2371         struct lwp *lp;
2372         struct rusage ru;
2373         int tmp;
2374
2375         if (ttycheckoutq(tp,0) == 0)
2376                 return;
2377
2378         /*
2379          * We always print the load average, then figure out what else to
2380          * print based on the state of the current process group.
2381          */
2382         tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
2383         ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
2384
2385         if (tp->t_session == NULL) {
2386                 ttyprintf(tp, "not a controlling terminal\n");
2387         } else if (tp->t_pgrp == NULL) {
2388                 ttyprintf(tp, "no foreground process group\n");
2389         } else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0) {
2390                 ttyprintf(tp, "empty foreground process group\n");
2391         } else {
2392                 /*
2393                  * Pick an interesting process.  Note that certain elements,
2394                  * in particular the wmesg, require a critical section for
2395                  * safe access (YYY and we are still not MP safe).
2396                  *
2397                  * NOTE: lwp_wmesg is lwp_thread->td_wmesg.
2398                  */
2399                 char buf[64];
2400                 const char *str;
2401                 long vmsz;
2402                 int pctcpu;
2403
2404                 crit_enter();
2405
2406                 /* XXX lwp should compare lwps */
2407
2408                 for (pick = NULL; p != 0; p = LIST_NEXT(p, p_pglist)) {
2409                         if (proc_compare(pick, p))
2410                                 pick = p;
2411                 }
2412
2413                 /* XXX lwp */
2414                 lp = FIRST_LWP_IN_PROC(pick);
2415                 if (lp == NULL) {
2416                         ttyprintf(tp, "foreground process without lwp\n");
2417                         tp->t_rocount = 0;
2418                         crit_exit();
2419                         return;
2420                 }
2421
2422                 /*
2423                  * Figure out what wait/process-state message, and command
2424                  * buffer to present
2425                  */
2426                 /*
2427                  * XXX lwp This is a horrible mixture.  We need to rework this
2428                  * as soon as lwps have their own runnable status.
2429                  */
2430                 if (pick->p_flag & P_WEXIT)
2431                         str = "exiting";
2432                 else if (lp->lwp_stat == LSRUN)
2433                         str = "running";
2434                 else if (pick->p_stat == SIDL)
2435                         str = "spawning";
2436                 else if (lp->lwp_wmesg) /* lwp_thread must not be NULL */
2437                         str = lp->lwp_wmesg;
2438                 else
2439                         str = "iowait";
2440
2441                 ksnprintf(buf, sizeof(buf), "cmd: %s %d [%s]",
2442                         pick->p_comm, pick->p_pid, str);
2443
2444                 /*
2445                  * Calculate cpu usage, percent cpu, and cmsz.  Note that
2446                  * 'pick' becomes invalid the moment we exit the critical
2447                  * section.
2448                  */
2449                 if (lp->lwp_thread && (pick->p_flag & P_SWAPPEDOUT) == 0)
2450                         calcru_proc(pick, &ru);
2451
2452                 pctcpu = (lp->lwp_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
2453
2454                 if (pick->p_stat == SIDL || pick->p_stat == SZOMB)
2455                     vmsz = 0;
2456                 else
2457                     vmsz = pgtok(vmspace_resident_count(pick->p_vmspace));
2458
2459                 crit_exit();
2460
2461                 /*
2462                  * Dump the output
2463                  */
2464                 ttyprintf(tp, " %s ", buf);
2465                 ttyprintf(tp, "%ld.%02ldu ",
2466                         ru.ru_utime.tv_sec, ru.ru_utime.tv_usec / 10000);
2467                 ttyprintf(tp, "%ld.%02lds ",
2468                         ru.ru_stime.tv_sec, ru.ru_stime.tv_usec / 10000);
2469                 ttyprintf(tp, "%d%% %ldk\n", pctcpu / 100, vmsz);
2470         }
2471         tp->t_rocount = 0;      /* so pending input will be retyped if BS */
2472 }
2473
2474 /*
2475  * Returns 1 if p2 is "better" than p1
2476  *
2477  * The algorithm for picking the "interesting" process is thus:
2478  *
2479  *      1) Only foreground processes are eligible - implied.
2480  *      2) Runnable processes are favored over anything else.  The runner
2481  *         with the highest cpu utilization is picked (p_cpticks).  Ties are
2482  *         broken by picking the highest pid.
2483  *      3) The sleeper with the shortest sleep time is next.  With ties,
2484  *         we pick out just "short-term" sleepers (LWP_SINTR == 0).
2485  *      4) Further ties are broken by picking the highest pid.
2486  */
2487 #define ISRUN(lp)       ((lp)->lwp_stat == LSRUN)
2488 #define TESTAB(a, b)    ((a)<<1 | (b))
2489 #define ONLYA   2
2490 #define ONLYB   1
2491 #define BOTH    3
2492
2493 static int
2494 proc_compare(struct proc *p1, struct proc *p2)
2495 {
2496         struct lwp *lp1, *lp2;
2497         if (p1 == NULL)
2498                 return (1);
2499
2500         /*
2501          * weed out zombies
2502          */
2503         switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) {
2504         case ONLYA:
2505                 return (1);
2506         case ONLYB:
2507                 return (0);
2508         case BOTH:
2509                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2510         }
2511
2512         /* XXX lwp */
2513         lp1 = FIRST_LWP_IN_PROC(p1);
2514         lp2 = FIRST_LWP_IN_PROC(p2);
2515
2516         /*
2517          * see if at least one of them is runnable
2518          */
2519         switch (TESTAB(ISRUN(lp1), ISRUN(lp2))) {
2520         case ONLYA:
2521                 return (0);
2522         case ONLYB:
2523                 return (1);
2524         case BOTH:
2525                 /*
2526                  * tie - favor one with highest recent cpu utilization
2527                  */
2528                 if (lp2->lwp_cpticks > lp1->lwp_cpticks)
2529                         return (1);
2530                 if (lp1->lwp_cpticks > lp2->lwp_cpticks)
2531                         return (0);
2532                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2533         }
2534         /*
2535          * pick the one with the smallest sleep time
2536          */
2537         if (lp2->lwp_slptime > lp1->lwp_slptime)
2538                 return (0);
2539         if (lp1->lwp_slptime > lp2->lwp_slptime)
2540                 return (1);
2541         /*
2542          * favor one sleeping in a non-interruptible sleep
2543          */
2544         if (lp1->lwp_flag & LWP_SINTR && (lp2->lwp_flag & LWP_SINTR) == 0)
2545                 return (1);
2546         if (lp2->lwp_flag & LWP_SINTR && (lp1->lwp_flag & LWP_SINTR) == 0)
2547                 return (0);
2548         return (p2->p_pid > p1->p_pid);         /* tie - return highest pid */
2549 }
2550
2551 /*
2552  * Output char to tty; console putchar style.
2553  */
2554 int
2555 tputchar(int c, struct tty *tp)
2556 {
2557         crit_enter();
2558         if (!ISSET(tp->t_state, TS_CONNECTED)) {
2559                 crit_exit();
2560                 return (-1);
2561         }
2562         if (c == '\n')
2563                 (void)ttyoutput('\r', tp);
2564         (void)ttyoutput(c, tp);
2565         ttstart(tp);
2566         crit_exit();
2567         return (0);
2568 }
2569
2570 /*
2571  * Sleep on chan, returning ERESTART if tty changed while we napped and
2572  * returning any errors (e.g. EINTR/EWOULDBLOCK) reported by tsleep.  If
2573  * the tty is revoked, restarting a pending call will redo validation done
2574  * at the start of the call.
2575  */
2576 int
2577 ttysleep(struct tty *tp, void *chan, int slpflags, char *wmesg, int timo)
2578 {
2579         int error;
2580         int gen;
2581
2582         gen = tp->t_gen;
2583         error = tsleep(chan, slpflags, wmesg, timo);
2584         if (error)
2585                 return (error);
2586         return (tp->t_gen == gen ? 0 : ERESTART);
2587 }
2588
2589 /*
2590  * Revoke a tty.
2591  *
2592  * We bump the gen to force any ttysleep()'s to return with ERESTART
2593  * and flush the tty.  The related fp's should already have been
2594  * replaced so the tty will close when the last references on the
2595  * original fp's go away.
2596  */
2597 int
2598 ttyrevoke(struct dev_revoke_args *ap)
2599 {
2600         struct tty *tp;
2601
2602         tp = ap->a_head.a_dev->si_tty;
2603         tp->t_gen++;
2604         ttyflush(tp, FREAD | FWRITE);
2605         wakeup(TSA_CARR_ON(tp));
2606         ttwakeup(tp);
2607         ttwwakeup(tp);
2608         return (0);
2609 }
2610
2611 /*
2612  * Allocate a tty struct.  Clists in the struct will be allocated by
2613  * ttyopen().
2614  */
2615 struct tty *
2616 ttymalloc(struct tty *tp)
2617 {
2618
2619         if (tp) {
2620                 return(tp);
2621         }
2622         tp = kmalloc(sizeof *tp, M_TTYS, M_WAITOK|M_ZERO);
2623         ttyregister(tp);
2624         return (tp);
2625 }
2626
2627 #if 0
2628 /*
2629  * Free a tty struct.  Clists in the struct should have been freed by
2630  * ttyclose().
2631  *
2632  * XXX not yet usable: since we support a half-closed state and do not
2633  * ref count the tty reference from the session, it is possible for a
2634  * session to hold a ref on the tty.  See TTY_DO_FULL_CLOSE.
2635  */
2636 void
2637 ttyfree(struct tty *tp)
2638 {
2639         kfree(tp, M_TTYS);
2640 }
2641 #endif /* 0 */
2642
2643 void
2644 ttyregister(struct tty *tp)
2645 {
2646         SLIST_INSERT_HEAD(&tty_list, tp, t_list);
2647 }
2648
2649 static int
2650 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
2651 {
2652         int error;
2653         struct tty *tp, t;
2654         SLIST_FOREACH(tp, &tty_list, t_list) {
2655                 t = *tp;
2656                 if (t.t_dev)
2657                         t.t_dev = (cdev_t)(uintptr_t)dev2udev(t.t_dev);
2658                 error = SYSCTL_OUT(req, (caddr_t)&t, sizeof(t));
2659                 if (error)
2660                         return (error);
2661         }
2662         return (0);
2663 }
2664
2665 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD,
2666         0, 0, sysctl_kern_ttys, "S,tty", "All struct ttys");
2667
2668 void
2669 nottystop(struct tty *tp, int rw)
2670 {
2671
2672         return;
2673 }
2674
2675 int
2676 ttyread(struct dev_read_args *ap)
2677 {
2678         struct tty *tp;
2679
2680         tp = ap->a_head.a_dev->si_tty;
2681         if (tp == NULL)
2682                 return (ENODEV);
2683         return ((*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag));
2684 }
2685
2686 int
2687 ttywrite(struct dev_write_args *ap)
2688 {
2689         struct tty *tp;
2690
2691         tp = ap->a_head.a_dev->si_tty;
2692         if (tp == NULL)
2693                 return (ENODEV);
2694         return ((*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag));
2695 }