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
1601 loop:
1602         crit_enter();
1603         lflag = tp->t_lflag;
1604         /*
1605          * take pending input first
1606          */
1607         if (ISSET(lflag, PENDIN)) {
1608                 ttypend(tp);
1609                 splz();         /* reduce latency */
1610                 lflag = tp->t_lflag;    /* XXX ttypend() clobbers it */
1611         }
1612
1613         /*
1614          * Hang process if it's in the background.
1615          */
1616         if ((pp = curproc) && isbackground(pp, tp)) {
1617                 crit_exit();
1618                 if (SIGISMEMBER(pp->p_sigignore, SIGTTIN) ||
1619                     SIGISMEMBER(lp->lwp_sigmask, SIGTTIN) ||
1620                     (pp->p_flag & P_PPWAIT) || pp->p_pgrp->pg_jobc == 0)
1621                         return (EIO);
1622                 pgsignal(pp->p_pgrp, SIGTTIN, 1);
1623                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg2", 0);
1624                 if (error)
1625                         return (error);
1626                 goto loop;
1627         }
1628
1629         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1630                 crit_exit();
1631                 return (0);     /* EOF */
1632         }
1633
1634         /*
1635          * If canonical, use the canonical queue,
1636          * else use the raw queue.
1637          *
1638          * (should get rid of clists...)
1639          */
1640         qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq;
1641
1642         if (flag & IO_NDELAY) {
1643                 if (qp->c_cc > 0)
1644                         goto read;
1645                 if (!ISSET(lflag, ICANON) && cc[VMIN] == 0) {
1646                         crit_exit();
1647                         return (0);
1648                 }
1649                 crit_exit();
1650                 return (EWOULDBLOCK);
1651         }
1652         if (!ISSET(lflag, ICANON)) {
1653                 int m = cc[VMIN];
1654                 long t = cc[VTIME];
1655                 struct timeval timecopy;
1656
1657                 /*
1658                  * Check each of the four combinations.
1659                  * (m > 0 && t == 0) is the normal read case.
1660                  * It should be fairly efficient, so we check that and its
1661                  * companion case (m == 0 && t == 0) first.
1662                  * For the other two cases, we compute the target sleep time
1663                  * into slp.
1664                  */
1665                 if (t == 0) {
1666                         if (qp->c_cc < m)
1667                                 goto sleep;
1668                         if (qp->c_cc > 0)
1669                                 goto read;
1670
1671                         /* m, t and qp->c_cc are all 0.  0 is enough input. */
1672                         crit_exit();
1673                         return (0);
1674                 }
1675                 t *= 100000;            /* time in us */
1676 #define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 1000000 + \
1677                          ((t1).tv_usec - (t2).tv_usec))
1678                 if (m > 0) {
1679                         if (qp->c_cc <= 0)
1680                                 goto sleep;
1681                         if (qp->c_cc >= m)
1682                                 goto read;
1683                         getmicrotime(&timecopy);
1684                         if (!has_stime) {
1685                                 /* first character, start timer */
1686                                 has_stime = 1;
1687                                 stime = timecopy;
1688                                 slp = t;
1689                         } else if (qp->c_cc > last_cc) {
1690                                 /* got a character, restart timer */
1691                                 stime = timecopy;
1692                                 slp = t;
1693                         } else {
1694                                 /* nothing, check expiration */
1695                                 slp = t - diff(timecopy, stime);
1696                                 if (slp <= 0)
1697                                         goto read;
1698                         }
1699                         last_cc = qp->c_cc;
1700                 } else {        /* m == 0 */
1701                         if (qp->c_cc > 0)
1702                                 goto read;
1703                         getmicrotime(&timecopy);
1704                         if (!has_stime) {
1705                                 has_stime = 1;
1706                                 stime = timecopy;
1707                                 slp = t;
1708                         } else {
1709                                 slp = t - diff(timecopy, stime);
1710                                 if (slp <= 0) {
1711                                         /* Timed out, but 0 is enough input. */
1712                                         crit_exit();
1713                                         return (0);
1714                                 }
1715                         }
1716                 }
1717 #undef diff
1718                 /*
1719                  * Rounding down may make us wake up just short
1720                  * of the target, so we round up.
1721                  * The formula is ceiling(slp * hz/1000000).
1722                  * 32-bit arithmetic is enough for hz < 169.
1723                  * XXX see tvtohz() for how to avoid overflow if hz
1724                  * is large (divide by `tick' and/or arrange to
1725                  * use tvtohz() if hz is large).
1726                  */
1727                 slp = (long) (((u_long)slp * hz) + 999999) / 1000000;
1728                 goto sleep;
1729         }
1730         if (qp->c_cc <= 0) {
1731 sleep:
1732                 /*
1733                  * There is no input, or not enough input and we can block.
1734                  */
1735                 error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), PCATCH,
1736                                  ISSET(tp->t_state, TS_CONNECTED) ?
1737                                  "ttyin" : "ttyhup", (int)slp);
1738                 crit_exit();
1739                 if (error == EWOULDBLOCK)
1740                         error = 0;
1741                 else if (error)
1742                         return (error);
1743                 /*
1744                  * XXX what happens if another process eats some input
1745                  * while we are asleep (not just here)?  It would be
1746                  * safest to detect changes and reset our state variables
1747                  * (has_stime and last_cc).
1748                  */
1749                 slp = 0;
1750                 goto loop;
1751         }
1752 read:
1753         crit_exit();
1754         /*
1755          * Input present, check for input mapping and processing.
1756          */
1757         first = 1;
1758         if (ISSET(lflag, ICANON | ISIG))
1759                 goto slowcase;
1760         for (;;) {
1761                 char ibuf[IBUFSIZ];
1762                 int icc;
1763
1764                 icc = imin(uio->uio_resid, IBUFSIZ);
1765                 icc = q_to_b(qp, ibuf, icc);
1766                 if (icc <= 0) {
1767                         if (first)
1768                                 goto loop;
1769                         break;
1770                 }
1771                 error = uiomove(ibuf, icc, uio);
1772                 /*
1773                  * XXX if there was an error then we should ungetc() the
1774                  * unmoved chars and reduce icc here.
1775                  */
1776                 if (error)
1777                         break;
1778                 if (uio->uio_resid == 0)
1779                         break;
1780                 first = 0;
1781         }
1782         goto out;
1783 slowcase:
1784         for (;;) {
1785                 c = clist_getc(qp);
1786                 if (c < 0) {
1787                         if (first)
1788                                 goto loop;
1789                         break;
1790                 }
1791                 /*
1792                  * delayed suspend (^Y)
1793                  */
1794                 if (CCEQ(cc[VDSUSP], c) &&
1795                     ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) {
1796                         pgsignal(tp->t_pgrp, SIGTSTP, 1);
1797                         if (first) {
1798                                 error = ttysleep(tp, &lbolt, PCATCH,
1799                                                  "ttybg3", 0);
1800                                 if (error)
1801                                         break;
1802                                 goto loop;
1803                         }
1804                         break;
1805                 }
1806                 /*
1807                  * Interpret EOF only in canonical mode.
1808                  */
1809                 if (CCEQ(cc[VEOF], c) && ISSET(lflag, ICANON))
1810                         break;
1811                 /*
1812                  * Give user character.
1813                  */
1814                 error = ureadc(c, uio);
1815                 if (error)
1816                         /* XXX should ungetc(c, qp). */
1817                         break;
1818                 if (uio->uio_resid == 0)
1819                         break;
1820                 /*
1821                  * In canonical mode check for a "break character"
1822                  * marking the end of a "line of input".
1823                  */
1824                 if (ISSET(lflag, ICANON) && TTBREAKC(c, lflag))
1825                         break;
1826                 first = 0;
1827         }
1828
1829 out:
1830         /*
1831          * Look to unblock input now that (presumably)
1832          * the input queue has gone down.
1833          */
1834         crit_enter();
1835         if (ISSET(tp->t_state, TS_TBLOCK) &&
1836             tp->t_rawq.c_cc + tp->t_canq.c_cc <= tp->t_ilowat)
1837                 ttyunblock(tp);
1838         crit_exit();
1839
1840         return (error);
1841 }
1842
1843 /*
1844  * Check the output queue on tp for space for a kernel message (from uprintf
1845  * or tprintf).  Allow some space over the normal hiwater mark so we don't
1846  * lose messages due to normal flow control, but don't let the tty run amok.
1847  * Sleeps here are not interruptible, but we return prematurely if new signals
1848  * arrive.
1849  */
1850 int
1851 ttycheckoutq(struct tty *tp, int wait)
1852 {
1853         struct lwp *lp = curthread->td_lwp;
1854         int hiwat;
1855         sigset_t oldset, newset;
1856
1857         hiwat = tp->t_ohiwat;
1858         SIGEMPTYSET(oldset);
1859         SIGEMPTYSET(newset);
1860         crit_enter();
1861         if (wait)
1862                 oldset = lwp_sigpend(lp);
1863         if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100) {
1864                 while (tp->t_outq.c_cc > hiwat) {
1865                         ttstart(tp);
1866                         if (tp->t_outq.c_cc <= hiwat)
1867                                 break;
1868                         if (wait)
1869                                 newset = lwp_sigpend(lp);
1870                         if (!wait || SIGSETNEQ(oldset, newset)) {
1871                                 crit_exit();
1872                                 return (0);
1873                         }
1874                         SET(tp->t_state, TS_SO_OLOWAT);
1875                         tsleep(TSA_OLOWAT(tp), 0, "ttoutq", hz);
1876                 }
1877         }
1878         crit_exit();
1879         return (1);
1880 }
1881
1882 /*
1883  * Process a write call on a tty device.
1884  */
1885 int
1886 ttwrite(struct tty *tp, struct uio *uio, int flag)
1887 {
1888         char *cp = NULL;
1889         int cc, ce;
1890         struct proc *pp;
1891         struct lwp *lp;
1892         int i, hiwat, cnt, error;
1893         char obuf[OBUFSIZ];
1894
1895         lp = curthread->td_lwp;
1896         hiwat = tp->t_ohiwat;
1897         cnt = uio->uio_resid;
1898         error = 0;
1899         cc = 0;
1900 loop:
1901         crit_enter();
1902         if (ISSET(tp->t_state, TS_ZOMBIE)) {
1903                 crit_exit();
1904                 if (uio->uio_resid == cnt)
1905                         error = EIO;
1906                 goto out;
1907         }
1908         if (!ISSET(tp->t_state, TS_CONNECTED)) {
1909                 if (flag & IO_NDELAY) {
1910                         crit_exit();
1911                         error = EWOULDBLOCK;
1912                         goto out;
1913                 }
1914                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ttydcd", 0);
1915                 crit_exit();
1916                 if (error)
1917                         goto out;
1918                 goto loop;
1919         }
1920         crit_exit();
1921
1922         /*
1923          * Hang the process if it's in the background.
1924          */
1925         if ((pp = curproc) && isbackground(pp, tp) &&
1926             ISSET(tp->t_lflag, TOSTOP) && !(pp->p_flag & P_PPWAIT) &&
1927             !SIGISMEMBER(pp->p_sigignore, SIGTTOU) &&
1928             !SIGISMEMBER(lp->lwp_sigmask, SIGTTOU)) {
1929                 if (pp->p_pgrp->pg_jobc == 0) {
1930                         error = EIO;
1931                         goto out;
1932                 }
1933                 pgsignal(pp->p_pgrp, SIGTTOU, 1);
1934                 error = ttysleep(tp, &lbolt, PCATCH, "ttybg4", 0);
1935                 if (error)
1936                         goto out;
1937                 goto loop;
1938         }
1939         /*
1940          * Process the user's data in at most OBUFSIZ chunks.  Perform any
1941          * output translation.  Keep track of high water mark, sleep on
1942          * overflow awaiting device aid in acquiring new space.
1943          */
1944         while (uio->uio_resid > 0 || cc > 0) {
1945                 if (ISSET(tp->t_lflag, FLUSHO)) {
1946                         uio->uio_resid = 0;
1947                         return (0);
1948                 }
1949                 if (tp->t_outq.c_cc > hiwat)
1950                         goto ovhiwat;
1951                 /*
1952                  * Grab a hunk of data from the user, unless we have some
1953                  * leftover from last time.
1954                  */
1955                 if (cc == 0) {
1956                         cc = imin(uio->uio_resid, OBUFSIZ);
1957                         cp = obuf;
1958                         error = uiomove(cp, cc, uio);
1959                         if (error) {
1960                                 cc = 0;
1961                                 break;
1962                         }
1963                 }
1964                 /*
1965                  * If nothing fancy need be done, grab those characters we
1966                  * can handle without any of ttyoutput's processing and
1967                  * just transfer them to the output q.  For those chars
1968                  * which require special processing (as indicated by the
1969                  * bits in char_type), call ttyoutput.  After processing
1970                  * a hunk of data, look for FLUSHO so ^O's will take effect
1971                  * immediately.
1972                  */
1973                 while (cc > 0) {
1974                         if (!ISSET(tp->t_oflag, OPOST))
1975                                 ce = cc;
1976                         else {
1977                                 ce = cc - scanc((u_int)cc, (u_char *)cp,
1978                                                 char_type, CCLASSMASK);
1979                                 /*
1980                                  * If ce is zero, then we're processing
1981                                  * a special character through ttyoutput.
1982                                  */
1983                                 if (ce == 0) {
1984                                         tp->t_rocount = 0;
1985                                         if (ttyoutput(*cp, tp) >= 0) {
1986                                                 /* No Clists, wait a bit. */
1987                                                 ttstart(tp);
1988                                                 if (flag & IO_NDELAY) {
1989                                                         error = EWOULDBLOCK;
1990                                                         goto out;
1991                                                 }
1992                                                 error = ttysleep(tp, &lbolt,
1993                                                                  PCATCH,
1994                                                                  "ttybf1", 0);
1995                                                 if (error)
1996                                                         goto out;
1997                                                 goto loop;
1998                                         }
1999                                         cp++;
2000                                         cc--;
2001                                         if (ISSET(tp->t_lflag, FLUSHO) ||
2002                                             tp->t_outq.c_cc > hiwat)
2003                                                 goto ovhiwat;
2004                                         continue;
2005                                 }
2006                         }
2007                         /*
2008                          * A bunch of normal characters have been found.
2009                          * Transfer them en masse to the output queue and
2010                          * continue processing at the top of the loop.
2011                          * If there are any further characters in this
2012                          * <= OBUFSIZ chunk, the first should be a character
2013                          * requiring special handling by ttyoutput.
2014                          */
2015                         tp->t_rocount = 0;
2016                         i = b_to_q(cp, ce, &tp->t_outq);
2017                         ce -= i;
2018                         tp->t_column += ce;
2019                         cp += ce, cc -= ce, tk_nout += ce;
2020                         tp->t_outcc += ce;
2021                         if (i > 0) {
2022                                 /* No Clists, wait a bit. */
2023                                 ttstart(tp);
2024                                 if (flag & IO_NDELAY) {
2025                                         error = EWOULDBLOCK;
2026                                         goto out;
2027                                 }
2028                                 error = ttysleep(tp, &lbolt, PCATCH,
2029                                                  "ttybf2", 0);
2030                                 if (error)
2031                                         goto out;
2032                                 goto loop;
2033                         }
2034                         if (ISSET(tp->t_lflag, FLUSHO) ||
2035                             tp->t_outq.c_cc > hiwat)
2036                                 break;
2037                 }
2038                 ttstart(tp);
2039         }
2040 out:
2041         /*
2042          * If cc is nonzero, we leave the uio structure inconsistent, as the
2043          * offset and iov pointers have moved forward, but it doesn't matter
2044          * (the call will either return short or restart with a new uio).
2045          */
2046         uio->uio_resid += cc;
2047         return (error);
2048
2049 ovhiwat:
2050         ttstart(tp);
2051         crit_enter();
2052         /*
2053          * This can only occur if FLUSHO is set in t_lflag,
2054          * or if ttstart/oproc is synchronous (or very fast).
2055          */
2056         if (tp->t_outq.c_cc <= hiwat) {
2057                 crit_exit();
2058                 goto loop;
2059         }
2060         if (flag & IO_NDELAY) {
2061                 crit_exit();
2062                 uio->uio_resid += cc;
2063                 return (uio->uio_resid == cnt ? EWOULDBLOCK : 0);
2064         }
2065         SET(tp->t_state, TS_SO_OLOWAT);
2066         error = ttysleep(tp, TSA_OLOWAT(tp), PCATCH, "ttywri", tp->t_timeout);
2067         crit_exit();
2068         if (error == EWOULDBLOCK)
2069                 error = EIO;
2070         if (error)
2071                 goto out;
2072         goto loop;
2073 }
2074
2075 /*
2076  * Rubout one character from the rawq of tp
2077  * as cleanly as possible.
2078  */
2079 static void
2080 ttyrub(int c, struct tty *tp)
2081 {
2082         char *cp;
2083         int savecol;
2084         int tabc;
2085
2086         if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC))
2087                 return;
2088         CLR(tp->t_lflag, FLUSHO);
2089         if (ISSET(tp->t_lflag, ECHOE)) {
2090                 if (tp->t_rocount == 0) {
2091                         /*
2092                          * Screwed by ttwrite; retype
2093                          */
2094                         ttyretype(tp);
2095                         return;
2096                 }
2097                 if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE))
2098                         ttyrubo(tp, 2);
2099                 else {
2100                         CLR(c, ~TTY_CHARMASK);
2101                         switch (CCLASS(c)) {
2102                         case ORDINARY:
2103                                 ttyrubo(tp, 1);
2104                                 break;
2105                         case BACKSPACE:
2106                         case CONTROL:
2107                         case NEWLINE:
2108                         case RETURN:
2109                         case VTAB:
2110                                 if (ISSET(tp->t_lflag, ECHOCTL))
2111                                         ttyrubo(tp, 2);
2112                                 break;
2113                         case TAB:
2114                                 if (tp->t_rocount < tp->t_rawq.c_cc) {
2115                                         ttyretype(tp);
2116                                         return;
2117                                 }
2118                                 crit_enter();
2119                                 savecol = tp->t_column;
2120                                 SET(tp->t_state, TS_CNTTB);
2121                                 SET(tp->t_lflag, FLUSHO);
2122                                 tp->t_column = tp->t_rocol;
2123                                 cp = tp->t_rawq.c_cf;
2124                                 if (cp)
2125                                         tabc = *cp;     /* XXX FIX NEXTC */
2126                                 for (; cp; cp = nextc(&tp->t_rawq, cp, &tabc))
2127                                         ttyecho(tabc, tp);
2128                                 CLR(tp->t_lflag, FLUSHO);
2129                                 CLR(tp->t_state, TS_CNTTB);
2130                                 crit_exit();
2131
2132                                 /* savecol will now be length of the tab. */
2133                                 savecol -= tp->t_column;
2134                                 tp->t_column += savecol;
2135                                 if (savecol > 8)
2136                                         savecol = 8;    /* overflow screw */
2137                                 while (--savecol >= 0)
2138                                         (void)ttyoutput('\b', tp);
2139                                 break;
2140                         default:                        /* XXX */
2141 #define PANICSTR        "ttyrub: would panic c = %d, val = %d\n"
2142                                 (void)kprintf(PANICSTR, c, CCLASS(c));
2143 #ifdef notdef
2144                                 panic(PANICSTR, c, CCLASS(c));
2145 #endif
2146                         }
2147                 }
2148         } else if (ISSET(tp->t_lflag, ECHOPRT)) {
2149                 if (!ISSET(tp->t_state, TS_ERASE)) {
2150                         SET(tp->t_state, TS_ERASE);
2151                         (void)ttyoutput('\\', tp);
2152                 }
2153                 ttyecho(c, tp);
2154         } else {
2155                 ttyecho(tp->t_cc[VERASE], tp);
2156                 /*
2157                  * This code may be executed not only when an ERASE key
2158                  * is pressed, but also when ^U (KILL) or ^W (WERASE) are.
2159                  * So, I didn't think it was worthwhile to pass the extra
2160                  * information (which would need an extra parameter,
2161                  * changing every call) needed to distinguish the ERASE2
2162                  * case from the ERASE.
2163                  */
2164         }
2165         --tp->t_rocount;
2166 }
2167
2168 /*
2169  * Back over cnt characters, erasing them.
2170  */
2171 static void
2172 ttyrubo(struct tty *tp, int cnt)
2173 {
2174
2175         while (cnt-- > 0) {
2176                 (void)ttyoutput('\b', tp);
2177                 (void)ttyoutput(' ', tp);
2178                 (void)ttyoutput('\b', tp);
2179         }
2180 }
2181
2182 /*
2183  * ttyretype --
2184  *      Reprint the rawq line.  Note, it is assumed that c_cc has already
2185  *      been checked.
2186  */
2187 static void
2188 ttyretype(struct tty *tp)
2189 {
2190         char *cp;
2191         int c;
2192
2193         /* Echo the reprint character. */
2194         if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
2195                 ttyecho(tp->t_cc[VREPRINT], tp);
2196
2197         (void)ttyoutput('\n', tp);
2198
2199         /*
2200          * XXX
2201          * FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE
2202          * BIT OF FIRST CHAR.
2203          */
2204         crit_enter();
2205         for (cp = tp->t_canq.c_cf, c = (cp != NULL ? *cp : 0);
2206             cp != NULL; cp = nextc(&tp->t_canq, cp, &c))
2207                 ttyecho(c, tp);
2208         for (cp = tp->t_rawq.c_cf, c = (cp != NULL ? *cp : 0);
2209             cp != NULL; cp = nextc(&tp->t_rawq, cp, &c))
2210                 ttyecho(c, tp);
2211         CLR(tp->t_state, TS_ERASE);
2212         crit_exit();
2213
2214         tp->t_rocount = tp->t_rawq.c_cc;
2215         tp->t_rocol = 0;
2216 }
2217
2218 /*
2219  * Echo a typed character to the terminal.
2220  */
2221 static void
2222 ttyecho(int c, struct tty *tp)
2223 {
2224
2225         if (!ISSET(tp->t_state, TS_CNTTB))
2226                 CLR(tp->t_lflag, FLUSHO);
2227         if ((!ISSET(tp->t_lflag, ECHO) &&
2228              (c != '\n' || !ISSET(tp->t_lflag, ECHONL))) ||
2229             ISSET(tp->t_lflag, EXTPROC))
2230                 return;
2231         if (ISSET(tp->t_lflag, ECHOCTL) &&
2232             ((ISSET(c, TTY_CHARMASK) <= 037 && c != '\t' && c != '\n') ||
2233             ISSET(c, TTY_CHARMASK) == 0177)) {
2234                 (void)ttyoutput('^', tp);
2235                 CLR(c, ~TTY_CHARMASK);
2236                 if (c == 0177)
2237                         c = '?';
2238                 else
2239                         c += 'A' - 1;
2240         }
2241         (void)ttyoutput(c, tp);
2242 }
2243
2244 /*
2245  * Wake up any readers on a tty.
2246  */
2247 void
2248 ttwakeup(struct tty *tp)
2249 {
2250
2251         if (tp->t_rsel.si_pid != 0)
2252                 selwakeup(&tp->t_rsel);
2253         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2254                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2255         wakeup(TSA_HUP_OR_INPUT(tp));
2256         KNOTE(&tp->t_rsel.si_note, 0);
2257 }
2258
2259 /*
2260  * Wake up any writers on a tty.
2261  */
2262 void
2263 ttwwakeup(struct tty *tp)
2264 {
2265
2266         if (tp->t_wsel.si_pid != 0 && tp->t_outq.c_cc <= tp->t_olowat)
2267                 selwakeup(&tp->t_wsel);
2268         if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
2269                 pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
2270         if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
2271             TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
2272                 CLR(tp->t_state, TS_SO_OCOMPLETE);
2273                 wakeup(TSA_OCOMPLETE(tp));
2274         }
2275         if (ISSET(tp->t_state, TS_SO_OLOWAT) &&
2276             tp->t_outq.c_cc <= tp->t_olowat) {
2277                 CLR(tp->t_state, TS_SO_OLOWAT);
2278                 wakeup(TSA_OLOWAT(tp));
2279         }
2280         KNOTE(&tp->t_wsel.si_note, 0);
2281 }
2282
2283 /*
2284  * Look up a code for a specified speed in a conversion table;
2285  * used by drivers to map software speed values to hardware parameters.
2286  */
2287 int
2288 ttspeedtab(int speed, struct speedtab *table)
2289 {
2290
2291         for ( ; table->sp_speed != -1; table++)
2292                 if (table->sp_speed == speed)
2293                         return (table->sp_code);
2294         return (-1);
2295 }
2296
2297 /*
2298  * Set input and output watermarks and buffer sizes.  For input, the
2299  * high watermark is about one second's worth of input above empty, the
2300  * low watermark is slightly below high water, and the buffer size is a
2301  * driver-dependent amount above high water.  For output, the watermarks
2302  * are near the ends of the buffer, with about 1 second's worth of input
2303  * between them.  All this only applies to the standard line discipline.
2304  */
2305 void
2306 ttsetwater(struct tty *tp)
2307 {
2308         int cps, ttmaxhiwat, x;
2309
2310         /* Input. */
2311         clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
2312         switch (tp->t_ispeedwat) {
2313         case (speed_t)-1:
2314                 cps = tp->t_ispeed / 10;
2315                 break;
2316         case 0:
2317                 /*
2318                  * This case is for old drivers that don't know about
2319                  * t_ispeedwat.  Arrange for them to get the old buffer
2320                  * sizes and watermarks.
2321                  */
2322                 cps = TTYHOG - 2 * 256;
2323                 tp->t_ififosize = 2 * 2048;
2324                 break;
2325         default:
2326                 cps = tp->t_ispeedwat / 10;
2327                 break;
2328         }
2329         tp->t_ihiwat = cps;
2330         tp->t_ilowat = 7 * cps / 8;
2331         x = cps + tp->t_ififosize;
2332         clist_alloc_cblocks(&tp->t_rawq, x, x);
2333
2334         /* Output. */
2335         switch (tp->t_ospeedwat) {
2336         case (speed_t)-1:
2337                 cps = tp->t_ospeed / 10;
2338                 ttmaxhiwat = 2 * TTMAXHIWAT;
2339                 break;
2340         case 0:
2341                 cps = tp->t_ospeed / 10;
2342                 ttmaxhiwat = TTMAXHIWAT;
2343                 break;
2344         default:
2345                 cps = tp->t_ospeedwat / 10;
2346                 ttmaxhiwat = 8 * TTMAXHIWAT;
2347                 break;
2348         }
2349 #define CLAMP(x, h, l)  ((x) > h ? h : ((x) < l) ? l : (x))
2350         tp->t_olowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
2351         x += cps;
2352         x = CLAMP(x, ttmaxhiwat, TTMINHIWAT);   /* XXX clamps are too magic */
2353         tp->t_ohiwat = roundup(x, CBSIZE);      /* XXX for compat */
2354         x = imax(tp->t_ohiwat, TTMAXHIWAT);     /* XXX for compat/safety */
2355         x += OBUFSIZ + 100;
2356         clist_alloc_cblocks(&tp->t_outq, x, x);
2357 #undef  CLAMP
2358 }
2359
2360 /*
2361  * Report on state of foreground process group.
2362  */
2363 void
2364 ttyinfo(struct tty *tp)
2365 {
2366         struct proc *p, *pick;
2367         struct lwp *lp;
2368         struct rusage ru;
2369         int tmp;
2370
2371         if (ttycheckoutq(tp,0) == 0)
2372                 return;
2373
2374         /*
2375          * We always print the load average, then figure out what else to
2376          * print based on the state of the current process group.
2377          */
2378         tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
2379         ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
2380
2381         if (tp->t_session == NULL) {
2382                 ttyprintf(tp, "not a controlling terminal\n");
2383         } else if (tp->t_pgrp == NULL) {
2384                 ttyprintf(tp, "no foreground process group\n");
2385         } else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0) {
2386                 ttyprintf(tp, "empty foreground process group\n");
2387         } else {
2388                 /*
2389                  * Pick an interesting process.  Note that certain elements,
2390                  * in particular the wmesg, require a critical section for
2391                  * safe access (YYY and we are still not MP safe).
2392                  *
2393                  * NOTE: lwp_wmesg is lwp_thread->td_wmesg.
2394                  */
2395                 char buf[64];
2396                 const char *str;
2397                 long vmsz;
2398                 int pctcpu;
2399
2400                 crit_enter();
2401
2402                 /* XXX lwp should compare lwps */
2403
2404                 for (pick = NULL; p != 0; p = LIST_NEXT(p, p_pglist)) {
2405                         if (proc_compare(pick, p))
2406                                 pick = p;
2407                 }
2408
2409                 /* XXX lwp */
2410                 lp = FIRST_LWP_IN_PROC(pick);
2411                 if (lp == NULL) {
2412                         ttyprintf(tp, "foreground process without lwp\n");
2413                         tp->t_rocount = 0;
2414                         crit_exit();
2415                         return;
2416                 }
2417
2418                 /*
2419                  * Figure out what wait/process-state message, and command
2420                  * buffer to present
2421                  */
2422                 /*
2423                  * XXX lwp This is a horrible mixture.  We need to rework this
2424                  * as soon as lwps have their own runnable status.
2425                  */
2426                 if (pick->p_flag & P_WEXIT)
2427                         str = "exiting";
2428                 else if (lp->lwp_stat == LSRUN)
2429                         str = "running";
2430                 else if (pick->p_stat == SIDL)
2431                         str = "spawning";
2432                 else if (lp->lwp_wmesg) /* lwp_thread must not be NULL */
2433                         str = lp->lwp_wmesg;
2434                 else
2435                         str = "iowait";
2436
2437                 ksnprintf(buf, sizeof(buf), "cmd: %s %d [%s]",
2438                         pick->p_comm, pick->p_pid, str);
2439
2440                 /*
2441                  * Calculate cpu usage, percent cpu, and cmsz.  Note that
2442                  * 'pick' becomes invalid the moment we exit the critical
2443                  * section.
2444                  */
2445                 if (lp->lwp_thread && (pick->p_flag & P_SWAPPEDOUT) == 0)
2446                         calcru_proc(pick, &ru);
2447
2448                 pctcpu = (lp->lwp_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
2449
2450                 if (pick->p_stat == SIDL || pick->p_stat == SZOMB)
2451                     vmsz = 0;
2452                 else
2453                     vmsz = pgtok(vmspace_resident_count(pick->p_vmspace));
2454
2455                 crit_exit();
2456
2457                 /*
2458                  * Dump the output
2459                  */
2460                 ttyprintf(tp, " %s ", buf);
2461                 ttyprintf(tp, "%ld.%02ldu ",
2462                         ru.ru_utime.tv_sec, ru.ru_utime.tv_usec / 10000);
2463                 ttyprintf(tp, "%ld.%02lds ",
2464                         ru.ru_stime.tv_sec, ru.ru_stime.tv_usec / 10000);
2465                 ttyprintf(tp, "%d%% %ldk\n", pctcpu / 100, vmsz);
2466         }
2467         tp->t_rocount = 0;      /* so pending input will be retyped if BS */
2468 }
2469
2470 /*
2471  * Returns 1 if p2 is "better" than p1
2472  *
2473  * The algorithm for picking the "interesting" process is thus:
2474  *
2475  *      1) Only foreground processes are eligible - implied.
2476  *      2) Runnable processes are favored over anything else.  The runner
2477  *         with the highest cpu utilization is picked (p_cpticks).  Ties are
2478  *         broken by picking the highest pid.
2479  *      3) The sleeper with the shortest sleep time is next.  With ties,
2480  *         we pick out just "short-term" sleepers (LWP_SINTR == 0).
2481  *      4) Further ties are broken by picking the highest pid.
2482  */
2483 #define ISRUN(lp)       ((lp)->lwp_stat == LSRUN)
2484 #define TESTAB(a, b)    ((a)<<1 | (b))
2485 #define ONLYA   2
2486 #define ONLYB   1
2487 #define BOTH    3
2488
2489 static int
2490 proc_compare(struct proc *p1, struct proc *p2)
2491 {
2492         struct lwp *lp1, *lp2;
2493         if (p1 == NULL)
2494                 return (1);
2495
2496         /*
2497          * weed out zombies
2498          */
2499         switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) {
2500         case ONLYA:
2501                 return (1);
2502         case ONLYB:
2503                 return (0);
2504         case BOTH:
2505                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2506         }
2507
2508         /* XXX lwp */
2509         lp1 = FIRST_LWP_IN_PROC(p1);
2510         lp2 = FIRST_LWP_IN_PROC(p2);
2511
2512         /*
2513          * see if at least one of them is runnable
2514          */
2515         switch (TESTAB(ISRUN(lp1), ISRUN(lp2))) {
2516         case ONLYA:
2517                 return (0);
2518         case ONLYB:
2519                 return (1);
2520         case BOTH:
2521                 /*
2522                  * tie - favor one with highest recent cpu utilization
2523                  */
2524                 if (lp2->lwp_cpticks > lp1->lwp_cpticks)
2525                         return (1);
2526                 if (lp1->lwp_cpticks > lp2->lwp_cpticks)
2527                         return (0);
2528                 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
2529         }
2530         /*
2531          * pick the one with the smallest sleep time
2532          */
2533         if (lp2->lwp_slptime > lp1->lwp_slptime)
2534                 return (0);
2535         if (lp1->lwp_slptime > lp2->lwp_slptime)
2536                 return (1);
2537         /*
2538          * favor one sleeping in a non-interruptible sleep
2539          */
2540         if (lp1->lwp_flag & LWP_SINTR && (lp2->lwp_flag & LWP_SINTR) == 0)
2541                 return (1);
2542         if (lp2->lwp_flag & LWP_SINTR && (lp1->lwp_flag & LWP_SINTR) == 0)
2543                 return (0);
2544         return (p2->p_pid > p1->p_pid);         /* tie - return highest pid */
2545 }
2546
2547 /*
2548  * Output char to tty; console putchar style.
2549  */
2550 int
2551 tputchar(int c, struct tty *tp)
2552 {
2553         crit_enter();
2554         if (!ISSET(tp->t_state, TS_CONNECTED)) {
2555                 crit_exit();
2556                 return (-1);
2557         }
2558         if (c == '\n')
2559                 (void)ttyoutput('\r', tp);
2560         (void)ttyoutput(c, tp);
2561         ttstart(tp);
2562         crit_exit();
2563         return (0);
2564 }
2565
2566 /*
2567  * Sleep on chan, returning ERESTART if tty changed while we napped and
2568  * returning any errors (e.g. EINTR/EWOULDBLOCK) reported by tsleep.  If
2569  * the tty is revoked, restarting a pending call will redo validation done
2570  * at the start of the call.
2571  */
2572 int
2573 ttysleep(struct tty *tp, void *chan, int slpflags, char *wmesg, int timo)
2574 {
2575         int error;
2576         int gen;
2577
2578         gen = tp->t_gen;
2579         error = tsleep(chan, slpflags, wmesg, timo);
2580         if (error)
2581                 return (error);
2582         return (tp->t_gen == gen ? 0 : ERESTART);
2583 }
2584
2585 /*
2586  * Revoke a tty.
2587  *
2588  * We bump the gen to force any ttysleep()'s to return with ERESTART
2589  * and flush the tty.  The related fp's should already have been
2590  * replaced so the tty will close when the last references on the
2591  * original fp's go away.
2592  */
2593 int
2594 ttyrevoke(struct dev_revoke_args *ap)
2595 {
2596         struct tty *tp;
2597
2598         tp = ap->a_head.a_dev->si_tty;
2599         tp->t_gen++;
2600         ttyflush(tp, FREAD | FWRITE);
2601         wakeup(TSA_CARR_ON(tp));
2602         ttwakeup(tp);
2603         ttwwakeup(tp);
2604         return (0);
2605 }
2606
2607 /*
2608  * Allocate a tty struct.  Clists in the struct will be allocated by
2609  * ttyopen().
2610  */
2611 struct tty *
2612 ttymalloc(struct tty *tp)
2613 {
2614
2615         if (tp) {
2616                 return(tp);
2617         }
2618         tp = kmalloc(sizeof *tp, M_TTYS, M_WAITOK|M_ZERO);
2619         ttyregister(tp);
2620         return (tp);
2621 }
2622
2623 #if 0
2624 /*
2625  * Free a tty struct.  Clists in the struct should have been freed by
2626  * ttyclose().
2627  *
2628  * XXX not yet usable: since we support a half-closed state and do not
2629  * ref count the tty reference from the session, it is possible for a
2630  * session to hold a ref on the tty.  See TTY_DO_FULL_CLOSE.
2631  */
2632 void
2633 ttyfree(struct tty *tp)
2634 {
2635         kfree(tp, M_TTYS);
2636 }
2637 #endif /* 0 */
2638
2639 void
2640 ttyregister(struct tty *tp)
2641 {
2642         SLIST_INSERT_HEAD(&tty_list, tp, t_list);
2643 }
2644
2645 static int
2646 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
2647 {
2648         int error;
2649         struct tty *tp, t;
2650         SLIST_FOREACH(tp, &tty_list, t_list) {
2651                 t = *tp;
2652                 if (t.t_dev)
2653                         t.t_dev = (cdev_t)(uintptr_t)dev2udev(t.t_dev);
2654                 error = SYSCTL_OUT(req, (caddr_t)&t, sizeof(t));
2655                 if (error)
2656                         return (error);
2657         }
2658         return (0);
2659 }
2660
2661 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD,
2662         0, 0, sysctl_kern_ttys, "S,tty", "All struct ttys");
2663
2664 void
2665 nottystop(struct tty *tp, int rw)
2666 {
2667
2668         return;
2669 }
2670
2671 int
2672 ttyread(struct dev_read_args *ap)
2673 {
2674         struct tty *tp;
2675
2676         tp = ap->a_head.a_dev->si_tty;
2677         if (tp == NULL)
2678                 return (ENODEV);
2679         return ((*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag));
2680 }
2681
2682 int
2683 ttywrite(struct dev_write_args *ap)
2684 {
2685         struct tty *tp;
2686
2687         tp = ap->a_head.a_dev->si_tty;
2688         if (tp == NULL)
2689                 return (ENODEV);
2690         return ((*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag));
2691 }