sys/kern/tty_pty.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)tty_pty.c   8.4 (Berkeley) 2/20/95
  34  * $FreeBSD: src/sys/kern/tty_pty.c,v 1.74.2.4 2002/02/20 19:58:13 dillon Exp $
  35  * $DragonFly: src/sys/kern/tty_pty.c,v 1.21 2008/08/13 10:29:38 swildner Exp $
  36  */
  37
  38 /*
  39  * Pseudo-teletype Driver
  40  * (Actually two drivers, requiring two dev_ops structures)
  41  */
  42 #include "use_pty.h"            /* XXX */
  43 #include "opt_compat.h"
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  48 #include <sys/ioctl_compat.h>
  49 #endif
  50 #include <sys/proc.h>
  51 #include <sys/priv.h>
  52 #include <sys/tty.h>
  53 #include <sys/conf.h>
  54 #include <sys/fcntl.h>
  55 #include <sys/poll.h>
  56 #include <sys/kernel.h>
  57 #include <sys/vnode.h>
  58 #include <sys/signalvar.h>
  59 #include <sys/malloc.h>
  60 #include <sys/device.h>
  61 #include <sys/thread2.h>
  62 #include <sys/devfs.h>
  63 #include <sys/stat.h>
  64 #include <sys/sysctl.h>
  65
  66 #define UNIX98_PTYS     1
  67
  68 MALLOC_DEFINE(M_PTY, "ptys", "pty data structures");
  69
  70 static void ptsstart (struct tty *tp);
  71 static void ptsstop (struct tty *tp, int rw);
  72 static void ptcwakeup (struct tty *tp, int flag);
  73 static void ptyinit (int n);
  74 static int  filt_ptcread (struct knote *kn, long hint);
  75 static void filt_ptcrdetach (struct knote *kn);
  76 static int  filt_ptcwrite (struct knote *kn, long hint);
  77 static void filt_ptcwdetach (struct knote *kn);
  78
  79 static  d_open_t        ptsopen;
  80 static  d_close_t       ptsclose;
  81 static  d_read_t        ptsread;
  82 static  d_write_t       ptswrite;
  83 static  d_ioctl_t       ptyioctl;
  84 static  d_open_t        ptcopen;
  85 static  d_close_t       ptcclose;
  86 static  d_read_t        ptcread;
  87 static  d_write_t       ptcwrite;
  88 static  d_poll_t        ptcpoll;
  89 static  d_kqfilter_t    ptckqfilter;
  90
  91 #ifdef UNIX98_PTYS
  92 DEVFS_DECLARE_CLONE_BITMAP(pty);
  93
  94 static  d_clone_t       ptyclone;
  95
  96 static int      pty_debug_level = 0;
  97
  98 static struct dev_ops pts98_ops = {
  99         { "pts98", 0, D_TTY | D_KQFILTER },
 100         .d_open =       ptsopen,
 101         .d_close =      ptsclose,
 102         .d_read =       ptsread,
 103         .d_write =      ptswrite,
 104         .d_ioctl =      ptyioctl,
 105         .d_poll =       ttypoll,
 106         .d_kqfilter =   ttykqfilter,
 107         .d_revoke =     ttyrevoke
 108 };
 109
 110 static struct dev_ops ptc98_ops = {
 111         { "ptc98", 0, D_TTY | D_KQFILTER | D_MASTER },
 112         .d_open =       ptcopen,
 113         .d_close =      ptcclose,
 114         .d_read =       ptcread,
 115         .d_write =      ptcwrite,
 116         .d_ioctl =      ptyioctl,
 117         .d_poll =       ptcpoll,
 118         .d_kqfilter =   ptckqfilter,
 119         .d_revoke =     ttyrevoke
 120 };
 121 #endif
 122
 123 #define CDEV_MAJOR_S    5
 124 static struct dev_ops pts_ops = {
 125         { "pts", CDEV_MAJOR_S, D_TTY | D_KQFILTER },
 126         .d_open =       ptsopen,
 127         .d_close =      ptsclose,
 128         .d_read =       ptsread,
 129         .d_write =      ptswrite,
 130         .d_ioctl =      ptyioctl,
 131         .d_poll =       ttypoll,
 132         .d_kqfilter =   ttykqfilter,
 133         .d_revoke =     ttyrevoke
 134 };
 135
 136 #define CDEV_MAJOR_C    6
 137 static struct dev_ops ptc_ops = {
 138         { "ptc", CDEV_MAJOR_C, D_TTY | D_KQFILTER | D_MASTER },
 139         .d_open =       ptcopen,
 140         .d_close =      ptcclose,
 141         .d_read =       ptcread,
 142         .d_write =      ptcwrite,
 143         .d_ioctl =      ptyioctl,
 144         .d_poll =       ptcpoll,
 145         .d_kqfilter =   ptckqfilter,
 146         .d_revoke =     ttyrevoke
 147 };
 148
 149 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
 150
 151 struct  pt_ioctl {
 152         int     pt_flags;
 153         int     pt_flags2;
 154         struct  selinfo pt_selr, pt_selw;
 155         u_char  pt_send;
 156         u_char  pt_ucntl;
 157         struct tty pt_tty;
 158         cdev_t  devs, devc;
 159         struct  prison *pt_prison;
 160 };
 161
 162 #define PF_PKT          0x08            /* packet mode */
 163 #define PF_STOPPED      0x10            /* user told stopped */
 164 #define PF_REMOTE       0x20            /* remote and flow controlled input */
 165 #define PF_NOSTOP       0x40
 166 #define PF_UCNTL        0x80            /* user control mode */
 167
 168 #define PF_UNIX98       0x01
 169 #define PF_SOPEN        0x02
 170 #define PF_MOPEN        0x04
 171
 172 static int
 173 ptydebug(int level, char *fmt, ...)
 174 {
 175         __va_list ap;
 176
 177         __va_start(ap, fmt);
 178         if (level <= pty_debug_level)
 179                 kvprintf(fmt, ap);
 180         __va_end(ap);
 181
 182         return 0;
 183 }
 184
 185 /*
 186  * This function creates and initializes a pts/ptc pair
 187  *
 188  * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
 189  * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
 190  *
 191  * XXX: define and add mapping of upper minor bits to allow more
 192  *      than 256 ptys.
 193  */
 194 static void
 195 ptyinit(int n)
 196 {
 197         cdev_t devs, devc;
 198         char *names = "pqrsPQRS";
 199         struct pt_ioctl *pt;
 200
 201         /* For now we only map the lower 8 bits of the minor */
 202         if (n & ~0xff)
 203                 return;
 204
 205         pt = kmalloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
 206         pt->devs = devs = make_dev(&pts_ops, n,
 207             0, 0, 0666, "tty%c%r", names[n / 32], n % 32);
 208         pt->devc = devc = make_dev(&ptc_ops, n,
 209             0, 0, 0666, "pty%c%r", names[n / 32], n % 32);
 210
 211         devs->si_drv1 = devc->si_drv1 = pt;
 212         devs->si_tty = devc->si_tty = &pt->pt_tty;
 213         devs->si_flags |= SI_OVERRIDE;  /* uid, gid, perms from dev */
 214         devc->si_flags |= SI_OVERRIDE;  /* uid, gid, perms from dev */
 215         pt->pt_tty.t_dev = devs;
 216         ttyregister(&pt->pt_tty);
 217 }
 218
 219 #ifdef UNIX98_PTYS
 220 static int
 221 ptyclone(struct dev_clone_args *ap)
 222 {
 223         int unit;
 224         struct pt_ioctl *pt;
 225
 226         /*
 227          * Limit the number of unix98 pty (slave) devices to 1000, as
 228          * the utmp(5) format only allows for 8 bytes for the tty,
 229          * "pts/XXX".
 230          * If this limit is reached, we don't clone and return error
 231          * to devfs.
 232          */
 233         unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(pty), 1000);
 234
 235         if (unit < 0) {
 236                 ap->a_dev = NULL;
 237                 return 1;
 238         }
 239
 240         pt = kmalloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
 241
 242         pt->devc = ap->a_dev = make_only_dev(&ptc98_ops, unit, ap->a_cred->cr_ruid,
 243             0, 0600, "ptm/%d", unit);
 244         pt->devs = make_dev(&pts98_ops, unit, ap->a_cred->cr_ruid, GID_TTY, 0620,
 245             "pts/%d", unit);
 246
 247         pt->devs->si_flags |= SI_OVERRIDE;      /* uid, gid, perms from dev */
 248         pt->devc->si_flags |= SI_OVERRIDE;      /* uid, gid, perms from dev */
 249
 250         pt->devs->si_drv1 = pt->devc->si_drv1 = pt;
 251         pt->devs->si_tty = pt->devc->si_tty = &pt->pt_tty;
 252         pt->pt_tty.t_dev = pt->devs;
 253         pt->pt_flags2 |= PF_UNIX98;
 254
 255         ttyregister(&pt->pt_tty);
 256
 257         return 0;
 258 }
 259 #endif
 260
 261 /*ARGSUSED*/
 262 static  int
 263 ptsopen(struct dev_open_args *ap)
 264 {
 265         cdev_t dev = ap->a_head.a_dev;
 266         struct tty *tp;
 267         int error;
 268         struct pt_ioctl *pti;
 269
 270         if (!dev->si_drv1)
 271                 ptyinit(minor(dev));
 272         if (!dev->si_drv1)
 273                 return(ENXIO);
 274         pti = dev->si_drv1;
 275         tp = dev->si_tty;
 276         if ((tp->t_state & TS_ISOPEN) == 0) {
 277                 ttychars(tp);           /* Set up default chars */
 278                 tp->t_iflag = TTYDEF_IFLAG;
 279                 tp->t_oflag = TTYDEF_OFLAG;
 280                 tp->t_lflag = TTYDEF_LFLAG;
 281                 tp->t_cflag = TTYDEF_CFLAG;
 282                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 283         } else if ((tp->t_state & TS_XCLUDE) && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
 284                 return (EBUSY);
 285         } else if (pti->pt_prison != ap->a_cred->cr_prison) {
 286                 return (EBUSY);
 287         }
 288         if (tp->t_oproc)                        /* Ctrlr still around. */
 289                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 290         while ((tp->t_state & TS_CARR_ON) == 0) {
 291                 if (ap->a_oflags & FNONBLOCK)
 292                         break;
 293                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ptsopn", 0);
 294                 if (error)
 295                         return (error);
 296         }
 297         error = (*linesw[tp->t_line].l_open)(dev, tp);
 298         if (error == 0)
 299                 ptcwakeup(tp, FREAD|FWRITE);
 300
 301 #ifdef UNIX98_PTYS
 302         /*
 303          * Unix98 pty stuff.
 304          * On open of the slave, we set the corresponding flag in the common
 305          * struct.
 306          */
 307         ptydebug(1, "ptsopen=%s | unix98? %s\n", dev->si_name,
 308             (pti->pt_flags2 & PF_UNIX98)?"yes":"no");
 309
 310         if ((!error) && (pti->pt_flags2 & PF_UNIX98)) {
 311                 pti->pt_flags2 |= PF_SOPEN;
 312         }
 313 #endif
 314
 315         return (error);
 316 }
 317
 318 static  int
 319 ptsclose(struct dev_close_args *ap)
 320 {
 321         cdev_t dev = ap->a_head.a_dev;
 322         struct tty *tp;
 323         struct pt_ioctl *pti = dev->si_drv1;
 324         int err;
 325
 326         tp = dev->si_tty;
 327         err = (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
 328         ptsstop(tp, FREAD|FWRITE);
 329         (void) ttyclose(tp);
 330
 331 #ifdef UNIX98_PTYS
 332         /*
 333          * Unix98 pty stuff.
 334          * On close of the slave, we unset the corresponding flag, and if the master
 335          * isn't open anymore, we destroy the slave and unset the unit.
 336          */
 337         ptydebug(1, "ptsclose=%s | unix98? %s\n", dev->si_name,
 338             (pti->pt_flags2 & PF_UNIX98)?"yes":"no");
 339
 340         if (pti->pt_flags2 & PF_UNIX98) {
 341                 pti->pt_flags2 &= ~PF_SOPEN;
 342                 KKASSERT((pti->pt_flags2 & PF_SOPEN) == 0);
 343                 ptydebug(1, "master open? %s\n",
 344                     (pti->pt_flags2 & PF_MOPEN)?"yes":"no");
 345
 346                 if (!(pti->pt_flags2 & PF_SOPEN) && !(pti->pt_flags2 & PF_MOPEN)) {
 347                         devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(pty), dev->si_uminor);
 348                         destroy_dev(dev);
 349                 }
 350         }
 351 #endif
 352
 353         return (err);
 354 }
 355
 356 static  int
 357 ptsread(struct dev_read_args *ap)
 358 {
 359         cdev_t dev = ap->a_head.a_dev;
 360         struct proc *p = curproc;
 361         struct tty *tp = dev->si_tty;
 362         struct pt_ioctl *pti = dev->si_drv1;
 363         struct lwp *lp;
 364
 365         int error = 0;
 366
 367         lp = curthread->td_lwp;
 368
 369 again:
 370         if (pti->pt_flags & PF_REMOTE) {
 371                 while (isbackground(p, tp)) {
 372                         if (SIGISMEMBER(p->p_sigignore, SIGTTIN) ||
 373                             SIGISMEMBER(lp->lwp_sigmask, SIGTTIN) ||
 374                             p->p_pgrp->pg_jobc == 0 || p->p_flag & P_PPWAIT)
 375                                 return (EIO);
 376                         pgsignal(p->p_pgrp, SIGTTIN, 1);
 377                         error = ttysleep(tp, &lbolt, PCATCH, "ptsbg", 0);
 378                         if (error)
 379                                 return (error);
 380                 }
 381                 if (tp->t_canq.c_cc == 0) {
 382                         if (ap->a_ioflag & IO_NDELAY)
 383                                 return (EWOULDBLOCK);
 384                         error = ttysleep(tp, TSA_PTS_READ(tp), PCATCH,
 385                                          "ptsin", 0);
 386                         if (error)
 387                                 return (error);
 388                         goto again;
 389                 }
 390                 while (tp->t_canq.c_cc > 1 && ap->a_uio->uio_resid > 0)
 391                         if (ureadc(clist_getc(&tp->t_canq), ap->a_uio) < 0) {
 392                                 error = EFAULT;
 393                                 break;
 394                         }
 395                 if (tp->t_canq.c_cc == 1)
 396                         clist_getc(&tp->t_canq);
 397                 if (tp->t_canq.c_cc)
 398                         return (error);
 399         } else
 400                 if (tp->t_oproc)
 401                         error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag);
 402         ptcwakeup(tp, FWRITE);
 403         return (error);
 404 }
 405
 406 /*
 407  * Write to pseudo-tty.
 408  * Wakeups of controlling tty will happen
 409  * indirectly, when tty driver calls ptsstart.
 410  */
 411 static  int
 412 ptswrite(struct dev_write_args *ap)
 413 {
 414         cdev_t dev = ap->a_head.a_dev;
 415         struct tty *tp;
 416
 417         tp = dev->si_tty;
 418         if (tp->t_oproc == 0)
 419                 return (EIO);
 420         return ((*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag));
 421 }
 422
 423 /*
 424  * Start output on pseudo-tty.
 425  * Wake up process selecting or sleeping for input from controlling tty.
 426  */
 427 static void
 428 ptsstart(struct tty *tp)
 429 {
 430         struct pt_ioctl *pti = tp->t_dev->si_drv1;
 431
 432         if (tp->t_state & TS_TTSTOP)
 433                 return;
 434         if (pti->pt_flags & PF_STOPPED) {
 435                 pti->pt_flags &= ~PF_STOPPED;
 436                 pti->pt_send = TIOCPKT_START;
 437         }
 438         ptcwakeup(tp, FREAD);
 439 }
 440
 441 static void
 442 ptcwakeup(struct tty *tp, int flag)
 443 {
 444         struct pt_ioctl *pti = tp->t_dev->si_drv1;
 445
 446         if (flag & FREAD) {
 447                 selwakeup(&pti->pt_selr);
 448                 wakeup(TSA_PTC_READ(tp));
 449                 KNOTE(&tp->t_rsel.si_note, 0);
 450         }
 451         if (flag & FWRITE) {
 452                 selwakeup(&pti->pt_selw);
 453                 wakeup(TSA_PTC_WRITE(tp));
 454                 KNOTE(&tp->t_wsel.si_note, 0);
 455         }
 456 }
 457
 458 static  int
 459 ptcopen(struct dev_open_args *ap)
 460 {
 461         cdev_t dev = ap->a_head.a_dev;
 462         struct tty *tp;
 463         struct pt_ioctl *pti;
 464
 465         if (!dev->si_drv1)
 466                 ptyinit(minor(dev));
 467         if (!dev->si_drv1)
 468                 return(ENXIO);
 469         pti = dev->si_drv1;
 470         if (pti->pt_prison && pti->pt_prison != ap->a_cred->cr_prison)
 471                 return(EBUSY);
 472         tp = dev->si_tty;
 473         if (tp->t_oproc)
 474                 return (EIO);
 475         tp->t_oproc = ptsstart;
 476         tp->t_stop = ptsstop;
 477         (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 478         tp->t_lflag &= ~EXTPROC;
 479         pti->pt_prison = ap->a_cred->cr_prison;
 480         pti->pt_flags = 0;
 481         pti->pt_send = 0;
 482         pti->pt_ucntl = 0;
 483
 484         pti->devs->si_uid = ap->a_cred->cr_uid;
 485         pti->devs->si_gid = 0;
 486         pti->devs->si_perms = 0600;
 487         pti->devc->si_uid = ap->a_cred->cr_uid;
 488         pti->devc->si_gid = 0;
 489         pti->devc->si_perms = 0600;
 490
 491 #ifdef UNIX98_PTYS
 492         /*
 493          * Unix98 pty stuff.
 494          * On open of the master, we set the corresponding flag in the common
 495          * struct.
 496          */
 497         ptydebug(1, "ptcopen=%s (master) | unix98? %s\n", dev->si_name,
 498             (pti->pt_flags2 & PF_UNIX98)?"yes":"no");
 499
 500         if (pti->pt_flags2 & PF_UNIX98) {
 501                 pti->pt_flags2 |= PF_MOPEN;
 502         }
 503 #endif
 504
 505         return (0);
 506 }
 507
 508 static  int
 509 ptcclose(struct dev_close_args *ap)
 510 {
 511         cdev_t dev = ap->a_head.a_dev;
 512         struct tty *tp;
 513         struct pt_ioctl *pti = dev->si_drv1;
 514
 515         tp = dev->si_tty;
 516         (void)(*linesw[tp->t_line].l_modem)(tp, 0);
 517
 518 #ifdef UNIX98_PTYS
 519         /*
 520          * Unix98 pty stuff.
 521          * On close of the master, we unset the corresponding flag in the common
 522          * struct asap.
 523          */
 524         pti->pt_flags2 &= ~PF_MOPEN;
 525 #endif
 526
 527         /*
 528          * XXX MDMBUF makes no sense for ptys but would inhibit the above
 529          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 530          * l_modem()s that ignore carrier drop make no sense for ptys but
 531          * may be in use because other parts of the line discipline make
 532          * sense for ptys.  Recover by doing everything that a normal
 533          * ttymodem() would have done except for sending a SIGHUP.
 534          */
 535         if (tp->t_state & TS_ISOPEN) {
 536                 tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 537                 tp->t_state |= TS_ZOMBIE;
 538                 ttyflush(tp, FREAD | FWRITE);
 539         }
 540         tp->t_oproc = 0;                /* mark closed */
 541
 542         pti = dev->si_drv1;
 543         pti->pt_prison = NULL;
 544         pti->devs->si_uid = 0;
 545         pti->devs->si_gid = 0;
 546         pti->devs->si_perms = 0666;
 547         pti->devc->si_uid = 0;
 548         pti->devc->si_gid = 0;
 549         pti->devc->si_perms = 0666;
 550
 551 #ifdef UNIX98_PTYS
 552         /*
 553          * Unix98 pty stuff.
 554          * On close of the master, we destroy the master and, if no slaves are open,
 555          * we destroy the slave device and unset the unit.
 556          */
 557         ptydebug(1, "ptcclose=%s (master) | unix98? %s\n", dev->si_name,
 558             (pti->pt_flags2 & PF_UNIX98)?"yes":"no");
 559         if (pti->pt_flags2 & PF_UNIX98) {
 560                 KKASSERT((pti->pt_flags2 & PF_MOPEN) == 0);
 561                 destroy_dev(dev);
 562                 pti->devc = NULL;
 563
 564                 if (!(pti->pt_flags2 & PF_SOPEN)) {
 565                         ptydebug(1, "ptcclose: slaves are not open\n");
 566                         destroy_dev(pti->devs);
 567                         devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(pty), dev->si_uminor);
 568                 }
 569         }
 570 #endif
 571
 572         return (0);
 573 }
 574
 575 static  int
 576 ptcread(struct dev_read_args *ap)
 577 {
 578         cdev_t dev = ap->a_head.a_dev;
 579         struct tty *tp = dev->si_tty;
 580         struct pt_ioctl *pti = dev->si_drv1;
 581         char buf[BUFSIZ];
 582         int error = 0, cc;
 583
 584         /*
 585          * We want to block until the slave
 586          * is open, and there's something to read;
 587          * but if we lost the slave or we're NBIO,
 588          * then return the appropriate error instead.
 589          */
 590         for (;;) {
 591                 if (tp->t_state&TS_ISOPEN) {
 592                         if (pti->pt_flags&PF_PKT && pti->pt_send) {
 593                                 error = ureadc((int)pti->pt_send, ap->a_uio);
 594                                 if (error)
 595                                         return (error);
 596                                 if (pti->pt_send & TIOCPKT_IOCTL) {
 597                                         cc = (int)szmin(ap->a_uio->uio_resid,
 598                                                         sizeof(tp->t_termios));
 599                                         uiomove((caddr_t)&tp->t_termios, cc,
 600                                                 ap->a_uio);
 601                                 }
 602                                 pti->pt_send = 0;
 603                                 return (0);
 604                         }
 605                         if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) {
 606                                 error = ureadc((int)pti->pt_ucntl, ap->a_uio);
 607                                 if (error)
 608                                         return (error);
 609                                 pti->pt_ucntl = 0;
 610                                 return (0);
 611                         }
 612                         if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
 613                                 break;
 614                 }
 615                 if ((tp->t_state & TS_CONNECTED) == 0)
 616                         return (0);     /* EOF */
 617                 if (ap->a_ioflag & IO_NDELAY)
 618                         return (EWOULDBLOCK);
 619                 error = tsleep(TSA_PTC_READ(tp), PCATCH, "ptcin", 0);
 620                 if (error)
 621                         return (error);
 622         }
 623         if (pti->pt_flags & (PF_PKT|PF_UCNTL))
 624                 error = ureadc(0, ap->a_uio);
 625         while (ap->a_uio->uio_resid > 0 && error == 0) {
 626                 cc = q_to_b(&tp->t_outq, buf,
 627                             (int)szmin(ap->a_uio->uio_resid, BUFSIZ));
 628                 if (cc <= 0)
 629                         break;
 630                 error = uiomove(buf, (size_t)cc, ap->a_uio);
 631         }
 632         ttwwakeup(tp);
 633         return (error);
 634 }
 635
 636 static  void
 637 ptsstop(struct tty *tp, int flush)
 638 {
 639         struct pt_ioctl *pti = tp->t_dev->si_drv1;
 640         int flag;
 641
 642         /* note: FLUSHREAD and FLUSHWRITE already ok */
 643         if (flush == 0) {
 644                 flush = TIOCPKT_STOP;
 645                 pti->pt_flags |= PF_STOPPED;
 646         } else
 647                 pti->pt_flags &= ~PF_STOPPED;
 648         pti->pt_send |= flush;
 649         /* change of perspective */
 650         flag = 0;
 651         if (flush & FREAD)
 652                 flag |= FWRITE;
 653         if (flush & FWRITE)
 654                 flag |= FREAD;
 655         ptcwakeup(tp, flag);
 656 }
 657
 658 static  int
 659 ptcpoll(struct dev_poll_args *ap)
 660 {
 661         cdev_t dev = ap->a_head.a_dev;
 662         struct tty *tp = dev->si_tty;
 663         struct pt_ioctl *pti = dev->si_drv1;
 664         int revents = 0;
 665
 666         if ((tp->t_state & TS_CONNECTED) == 0) {
 667                 ap->a_events = seltrue(dev, ap->a_events) | POLLHUP;
 668                 return(0);
 669         }
 670
 671         /*
 672          * Need to block timeouts (ttrstart).
 673          */
 674         crit_enter();
 675
 676         if (ap->a_events & (POLLIN | POLLRDNORM))
 677                 if ((tp->t_state & TS_ISOPEN) &&
 678                     ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
 679                      ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
 680                      ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)))
 681                         revents |= ap->a_events & (POLLIN | POLLRDNORM);
 682
 683         if (ap->a_events & (POLLOUT | POLLWRNORM))
 684                 if (tp->t_state & TS_ISOPEN &&
 685                     ((pti->pt_flags & PF_REMOTE) ?
 686                      (tp->t_canq.c_cc == 0) :
 687                      ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
 688                       (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON)))))
 689                         revents |= ap->a_events & (POLLOUT | POLLWRNORM);
 690
 691         if (ap->a_events & POLLHUP)
 692                 if ((tp->t_state & TS_CARR_ON) == 0)
 693                         revents |= POLLHUP;
 694
 695         if (revents == 0) {
 696                 if (ap->a_events & (POLLIN | POLLRDNORM))
 697                         selrecord(curthread, &pti->pt_selr);
 698
 699                 if (ap->a_events & (POLLOUT | POLLWRNORM))
 700                         selrecord(curthread, &pti->pt_selw);
 701         }
 702         crit_exit();
 703
 704         ap->a_events = revents;
 705         return (0);
 706 }
 707
 708 /*
 709  * kqueue ops for pseudo-terminals.
 710  */
 711 static struct filterops ptcread_filtops =
 712         { 1, NULL, filt_ptcrdetach, filt_ptcread };
 713 static struct filterops ptcwrite_filtops =
 714         { 1, NULL, filt_ptcwdetach, filt_ptcwrite };
 715
 716 static  int
 717 ptckqfilter(struct dev_kqfilter_args *ap)
 718 {
 719         cdev_t dev = ap->a_head.a_dev;
 720         struct knote *kn = ap->a_kn;
 721         struct tty *tp = dev->si_tty;
 722         struct klist *klist;
 723
 724         ap->a_result = 0;
 725         switch (kn->kn_filter) {
 726         case EVFILT_READ:
 727                 klist = &tp->t_rsel.si_note;
 728                 kn->kn_fop = &ptcread_filtops;
 729                 break;
 730         case EVFILT_WRITE:
 731                 klist = &tp->t_wsel.si_note;
 732                 kn->kn_fop = &ptcwrite_filtops;
 733                 break;
 734         default:
 735                 ap->a_result = 1;
 736                 return (0);
 737         }
 738
 739         kn->kn_hook = (caddr_t)dev;
 740
 741         crit_enter();
 742         SLIST_INSERT_HEAD(klist, kn, kn_selnext);
 743         crit_exit();
 744
 745         return (0);
 746 }
 747
 748 static int
 749 filt_ptcread (struct knote *kn, long hint)
 750 {
 751         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
 752         struct pt_ioctl *pti = ((cdev_t)kn->kn_hook)->si_drv1;
 753
 754         if ((tp->t_state & TS_ISOPEN) &&
 755             ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
 756              ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
 757              ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))) {
 758                 kn->kn_data = tp->t_outq.c_cc;
 759                 return(1);
 760         } else {
 761                 return(0);
 762         }
 763 }
 764
 765 static int
 766 filt_ptcwrite (struct knote *kn, long hint)
 767 {
 768         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
 769         struct pt_ioctl *pti = ((cdev_t)kn->kn_hook)->si_drv1;
 770
 771         if (tp->t_state & TS_ISOPEN &&
 772             ((pti->pt_flags & PF_REMOTE) ?
 773              (tp->t_canq.c_cc == 0) :
 774              ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
 775               (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON))))) {
 776                 kn->kn_data = tp->t_canq.c_cc + tp->t_rawq.c_cc;
 777                 return(1);
 778         } else {
 779                 return(0);
 780         }
 781 }
 782
 783 static void
 784 filt_ptcrdetach (struct knote *kn)
 785 {
 786         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
 787
 788         crit_enter();
 789         SLIST_REMOVE(&tp->t_rsel.si_note, kn, knote, kn_selnext);
 790         crit_exit();
 791 }
 792
 793 static void
 794 filt_ptcwdetach (struct knote *kn)
 795 {
 796         struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
 797
 798         crit_enter();
 799         SLIST_REMOVE(&tp->t_wsel.si_note, kn, knote, kn_selnext);
 800         crit_exit();
 801 }
 802
 803 /*
 804  * I/O ops
 805  */
 806 static  int
 807 ptcwrite(struct dev_write_args *ap)
 808 {
 809         cdev_t dev = ap->a_head.a_dev;
 810         struct tty *tp = dev->si_tty;
 811         u_char *cp = 0;
 812         int cc = 0;
 813         u_char locbuf[BUFSIZ];
 814         int cnt = 0;
 815         struct pt_ioctl *pti = dev->si_drv1;
 816         int error = 0;
 817
 818 again:
 819         if ((tp->t_state&TS_ISOPEN) == 0)
 820                 goto block;
 821         if (pti->pt_flags & PF_REMOTE) {
 822                 if (tp->t_canq.c_cc)
 823                         goto block;
 824                 while ((ap->a_uio->uio_resid > 0 || cc > 0) &&
 825                        tp->t_canq.c_cc < TTYHOG - 1) {
 826                         if (cc == 0) {
 827                                 cc = (int)szmin(ap->a_uio->uio_resid, BUFSIZ);
 828                                 cc = imin(cc, TTYHOG - 1 - tp->t_canq.c_cc);
 829                                 cp = locbuf;
 830                                 error = uiomove(cp, (size_t)cc, ap->a_uio);
 831                                 if (error)
 832                                         return (error);
 833                                 /* check again for safety */
 834                                 if ((tp->t_state & TS_ISOPEN) == 0) {
 835                                         /* adjust as usual */
 836                                         ap->a_uio->uio_resid += cc;
 837                                         return (EIO);
 838                                 }
 839                         }
 840                         if (cc > 0) {
 841                                 cc = b_to_q((char *)cp, cc, &tp->t_canq);
 842                                 /*
 843                                  * XXX we don't guarantee that the canq size
 844                                  * is >= TTYHOG, so the above b_to_q() may
 845                                  * leave some bytes uncopied.  However, space
 846                                  * is guaranteed for the null terminator if
 847                                  * we don't fail here since (TTYHOG - 1) is
 848                                  * not a multiple of CBSIZE.
 849                                  */
 850                                 if (cc > 0)
 851                                         break;
 852                         }
 853                 }
 854                 /* adjust for data copied in but not written */
 855                 ap->a_uio->uio_resid += cc;
 856                 clist_putc(0, &tp->t_canq);
 857                 ttwakeup(tp);
 858                 wakeup(TSA_PTS_READ(tp));
 859                 return (0);
 860         }
 861         while (ap->a_uio->uio_resid > 0 || cc > 0) {
 862                 if (cc == 0) {
 863                         cc = (int)szmin(ap->a_uio->uio_resid, BUFSIZ);
 864                         cp = locbuf;
 865                         error = uiomove(cp, (size_t)cc, ap->a_uio);
 866                         if (error)
 867                                 return (error);
 868                         /* check again for safety */
 869                         if ((tp->t_state & TS_ISOPEN) == 0) {
 870                                 /* adjust for data copied in but not written */
 871                                 ap->a_uio->uio_resid += cc;
 872                                 return (EIO);
 873                         }
 874                 }
 875                 while (cc > 0) {
 876                         if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
 877                            (tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) {
 878                                 wakeup(TSA_HUP_OR_INPUT(tp));
 879                                 goto block;
 880                         }
 881                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
 882                         cnt++;
 883                         cc--;
 884                 }
 885                 cc = 0;
 886         }
 887         return (0);
 888 block:
 889         /*
 890          * Come here to wait for slave to open, for space
 891          * in outq, or space in rawq, or an empty canq.
 892          */
 893         if ((tp->t_state & TS_CONNECTED) == 0) {
 894                 /* adjust for data copied in but not written */
 895                 ap->a_uio->uio_resid += cc;
 896                 return (EIO);
 897         }
 898         if (ap->a_ioflag & IO_NDELAY) {
 899                 /* adjust for data copied in but not written */
 900                 ap->a_uio->uio_resid += cc;
 901                 if (cnt == 0)
 902                         return (EWOULDBLOCK);
 903                 return (0);
 904         }
 905         error = tsleep(TSA_PTC_WRITE(tp), PCATCH, "ptcout", 0);
 906         if (error) {
 907                 /* adjust for data copied in but not written */
 908                 ap->a_uio->uio_resid += cc;
 909                 return (error);
 910         }
 911         goto again;
 912 }
 913
 914 /*ARGSUSED*/
 915 static  int
 916 ptyioctl(struct dev_ioctl_args *ap)
 917 {
 918         cdev_t dev = ap->a_head.a_dev;
 919         struct tty *tp = dev->si_tty;
 920         struct pt_ioctl *pti = dev->si_drv1;
 921         u_char *cc = tp->t_cc;
 922         int stop, error;
 923
 924         if (dev_dflags(dev) & D_MASTER) {
 925                 switch (ap->a_cmd) {
 926
 927                 case TIOCGPGRP:
 928                         /*
 929                          * We avoid calling ttioctl on the controller since,
 930                          * in that case, tp must be the controlling terminal.
 931                          */
 932                         *(int *)ap->a_data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
 933                         return (0);
 934
 935                 case TIOCPKT:
 936                         if (*(int *)ap->a_data) {
 937                                 if (pti->pt_flags & PF_UCNTL)
 938                                         return (EINVAL);
 939                                 pti->pt_flags |= PF_PKT;
 940                         } else
 941                                 pti->pt_flags &= ~PF_PKT;
 942                         return (0);
 943
 944                 case TIOCUCNTL:
 945                         if (*(int *)ap->a_data) {
 946                                 if (pti->pt_flags & PF_PKT)
 947                                         return (EINVAL);
 948                                 pti->pt_flags |= PF_UCNTL;
 949                         } else
 950                                 pti->pt_flags &= ~PF_UCNTL;
 951                         return (0);
 952
 953                 case TIOCREMOTE:
 954                         if (*(int *)ap->a_data)
 955                                 pti->pt_flags |= PF_REMOTE;
 956                         else
 957                                 pti->pt_flags &= ~PF_REMOTE;
 958                         ttyflush(tp, FREAD|FWRITE);
 959                         return (0);
 960
 961                 case TIOCISPTMASTER:
 962                         if ((pti->pt_flags2 & PF_UNIX98) && (pti->devc == dev))
 963                                 return (0);
 964                         else
 965                                 return (EINVAL);
 966                 }
 967
 968                 /*
 969                  * The rest of the ioctls shouldn't be called until
 970                  * the slave is open.
 971                  */
 972                 if ((tp->t_state & TS_ISOPEN) == 0)
 973                         return (EAGAIN);
 974
 975                 switch (ap->a_cmd) {
 976 #ifdef COMPAT_43
 977                 case TIOCSETP:
 978                 case TIOCSETN:
 979 #endif
 980                 case TIOCSETD:
 981                 case TIOCSETA:
 982                 case TIOCSETAW:
 983                 case TIOCSETAF:
 984                         /*
 985                          * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
 986                          * ttywflush(tp) will hang if there are characters in
 987                          * the outq.
 988                          */
 989                         ndflush(&tp->t_outq, tp->t_outq.c_cc);
 990                         break;
 991
 992                 case TIOCSIG:
 993                         if (*(unsigned int *)ap->a_data >= NSIG ||
 994                             *(unsigned int *)ap->a_data == 0)
 995                                 return(EINVAL);
 996                         if ((tp->t_lflag&NOFLSH) == 0)
 997                                 ttyflush(tp, FREAD|FWRITE);
 998                         pgsignal(tp->t_pgrp, *(unsigned int *)ap->a_data, 1);
 999                         if ((*(unsigned int *)ap->a_data == SIGINFO) &&
1000                             ((tp->t_lflag&NOKERNINFO) == 0))
1001                                 ttyinfo(tp);
1002                         return(0);
1003                 }
1004         }
1005         if (ap->a_cmd == TIOCEXT) {
1006                 /*
1007                  * When the EXTPROC bit is being toggled, we need
1008                  * to send an TIOCPKT_IOCTL if the packet driver
1009                  * is turned on.
1010                  */
1011                 if (*(int *)ap->a_data) {
1012                         if (pti->pt_flags & PF_PKT) {
1013                                 pti->pt_send |= TIOCPKT_IOCTL;
1014                                 ptcwakeup(tp, FREAD);
1015                         }
1016                         tp->t_lflag |= EXTPROC;
1017                 } else {
1018                         if ((tp->t_lflag & EXTPROC) &&
1019                             (pti->pt_flags & PF_PKT)) {
1020                                 pti->pt_send |= TIOCPKT_IOCTL;
1021                                 ptcwakeup(tp, FREAD);
1022                         }
1023                         tp->t_lflag &= ~EXTPROC;
1024                 }
1025                 return(0);
1026         }
1027         error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
1028                                               ap->a_fflag, ap->a_cred);
1029         if (error == ENOIOCTL)
1030                  error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
1031         if (error == ENOIOCTL) {
1032                 if (pti->pt_flags & PF_UCNTL &&
1033                     (ap->a_cmd & ~0xff) == UIOCCMD(0)) {
1034                         if (ap->a_cmd & 0xff) {
1035                                 pti->pt_ucntl = (u_char)ap->a_cmd;
1036                                 ptcwakeup(tp, FREAD);
1037                         }
1038                         return (0);
1039                 }
1040                 error = ENOTTY;
1041         }
1042         /*
1043          * If external processing and packet mode send ioctl packet.
1044          */
1045         if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) {
1046                 switch(ap->a_cmd) {
1047                 case TIOCSETA:
1048                 case TIOCSETAW:
1049                 case TIOCSETAF:
1050 #ifdef COMPAT_43
1051                 case TIOCSETP:
1052                 case TIOCSETN:
1053 #endif
1054 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1055                 case TIOCSETC:
1056                 case TIOCSLTC:
1057                 case TIOCLBIS:
1058                 case TIOCLBIC:
1059                 case TIOCLSET:
1060 #endif
1061                         pti->pt_send |= TIOCPKT_IOCTL;
1062                         ptcwakeup(tp, FREAD);
1063                 default:
1064                         break;
1065                 }
1066         }
1067         stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
1068                 && CCEQ(cc[VSTART], CTRL('q'));
1069         if (pti->pt_flags & PF_NOSTOP) {
1070                 if (stop) {
1071                         pti->pt_send &= ~TIOCPKT_NOSTOP;
1072                         pti->pt_send |= TIOCPKT_DOSTOP;
1073                         pti->pt_flags &= ~PF_NOSTOP;
1074                         ptcwakeup(tp, FREAD);
1075                 }
1076         } else {
1077                 if (!stop) {
1078                         pti->pt_send &= ~TIOCPKT_DOSTOP;
1079                         pti->pt_send |= TIOCPKT_NOSTOP;
1080                         pti->pt_flags |= PF_NOSTOP;
1081                         ptcwakeup(tp, FREAD);
1082                 }
1083         }
1084         return (error);
1085 }
1086
1087
1088 static void ptc_drvinit (void *unused);
1089
1090 #ifdef UNIX98_PTYS
1091 SYSCTL_INT(_kern, OID_AUTO, pty_debug, CTLFLAG_RW, &pty_debug_level,
1092                 0, "Change pty debug level");
1093 #endif
1094
1095 static void
1096 ptc_drvinit(void *unused)
1097 {
1098         int i;
1099
1100 #ifdef UNIX98_PTYS
1101         /*
1102          * Unix98 pty stuff.
1103          * Create the clonable base device.
1104          */
1105         make_autoclone_dev(&ptc_ops, &DEVFS_CLONE_BITMAP(pty), ptyclone,
1106             0, 0, 0666, "ptmx");
1107 #endif
1108
1109         for (i = 0; i < 256; i++) {
1110                 ptyinit(i);
1111         }
1112 }
1113
1114 SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR_C,ptc_drvinit,NULL)