sys/dev/misc/nmdm/nmdm.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  * $FreeBSD: src/sys/dev/nmdm/nmdm.c,v 1.5.2.1 2001/08/11 00:54:14 mp Exp $
  34  */
  35
  36 /*
  37  * Pseudo-nulmodem Driver
  38  */
  39 #include "opt_compat.h"
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  43 #include <sys/ioctl_compat.h>
  44 #endif
  45 #include <sys/proc.h>
  46 #include <sys/tty.h>
  47 #include <sys/conf.h>
  48 #include <sys/fcntl.h>
  49 #include <sys/poll.h>
  50 #include <sys/kernel.h>
  51 #include <sys/vnode.h>
  52 #include <sys/signalvar.h>
  53 #include <sys/malloc.h>
  54
  55 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
  56
  57 static void nmdmstart __P((struct tty *tp));
  58 static void nmdmstop __P((struct tty *tp, int rw));
  59 static void wakeup_other __P((struct tty *tp, int flag));
  60 static void nmdminit __P((int n));
  61
  62 static  d_open_t        nmdmopen;
  63 static  d_close_t       nmdmclose;
  64 static  d_read_t        nmdmread;
  65 static  d_write_t       nmdmwrite;
  66 static  d_ioctl_t       nmdmioctl;
  67
  68 #define CDEV_MAJOR      18
  69 static struct cdevsw nmdm_cdevsw = {
  70         /* open */      nmdmopen,
  71         /* close */     nmdmclose,
  72         /* read */      nmdmread,
  73         /* write */     nmdmwrite,
  74         /* ioctl */     nmdmioctl,
  75         /* poll */      ttypoll,
  76         /* mmap */      nommap,
  77         /* strategy */  nostrategy,
  78         /* name */      "pts",
  79         /* maj */       CDEV_MAJOR,
  80         /* dump */      nodump,
  81         /* psize */     nopsize,
  82         /* flags */     D_TTY,
  83         /* bmaj */      -1
  84 };
  85
  86 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
  87
  88 struct softpart {
  89         struct tty nm_tty;
  90         dev_t   dev;
  91         int     modemsignals;   /* bits defined in sys/ttycom.h */
  92         int     gotbreak;
  93 };
  94
  95 struct  nm_softc {
  96         int     pt_flags;
  97         struct softpart part1, part2;
  98         struct  prison *pt_prison;
  99 };
 100
 101 #define PF_STOPPED      0x10            /* user told stopped */
 102
 103 static void
 104 nmdm_crossover(struct nm_softc *pti,
 105                 struct softpart *ourpart,
 106                 struct softpart *otherpart);
 107
 108 #define GETPARTS(tp, ourpart, otherpart) \
 109 do {    \
 110         struct nm_softc *pti = tp->t_dev->si_drv1; \
 111         if (tp == &pti->part1.nm_tty) { \
 112                 ourpart = &pti->part1; \
 113                 otherpart = &pti->part2; \
 114         } else { \
 115                 ourpart = &pti->part2; \
 116                 otherpart = &pti->part1; \
 117         }  \
 118 } while (0)
 119
 120 /*
 121  * This function creates and initializes a pair of ttys.
 122  */
 123 static void
 124 nmdminit(n)
 125         int n;
 126 {
 127         dev_t dev1, dev2;
 128         struct nm_softc *pt;
 129
 130         /* For now we only map the lower 8 bits of the minor */
 131         if (n & ~0xff)
 132                 return;
 133
 134         pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
 135         bzero(pt, sizeof(*pt));
 136         pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n,
 137             0, 0, 0666, "nmdm%dA", n);
 138         pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1,
 139             0, 0, 0666, "nmdm%dB", n);
 140
 141         dev1->si_drv1 = dev2->si_drv1 = pt;
 142         dev1->si_tty = &pt->part1.nm_tty;
 143         dev2->si_tty = &pt->part2.nm_tty;
 144         ttyregister(&pt->part1.nm_tty);
 145         ttyregister(&pt->part2.nm_tty);
 146         pt->part1.nm_tty.t_oproc = nmdmstart;
 147         pt->part2.nm_tty.t_oproc = nmdmstart;
 148         pt->part1.nm_tty.t_stop = nmdmstop;
 149         pt->part2.nm_tty.t_dev = dev1;
 150         pt->part1.nm_tty.t_dev = dev2;
 151         pt->part2.nm_tty.t_stop = nmdmstop;
 152 }
 153
 154 /*ARGSUSED*/
 155 static  int
 156 nmdmopen(dev, flag, devtype, p)
 157         dev_t dev;
 158         int flag, devtype;
 159         struct proc *p;
 160 {
 161         register struct tty *tp, *tp2;
 162         int error;
 163         int minr;
 164         dev_t nextdev;
 165         struct nm_softc *pti;
 166         int is_b;
 167         int     pair;
 168         struct  softpart *ourpart, *otherpart;
 169
 170         /*
 171          * XXX: Gross hack for DEVFS:
 172          * If we openned this device, ensure we have the
 173          * next one too, so people can open it.
 174          */
 175         minr = lminor(dev);
 176         pair = minr >> 1;
 177         is_b = minr & 1;
 178
 179         if (pair < 127) {
 180                 nextdev = makedev(major(dev), (pair+pair) + 1);
 181                 if (!nextdev->si_drv1) {
 182                         nmdminit(pair + 1);
 183                 }
 184         }
 185         if (!dev->si_drv1)
 186                 nmdminit(pair);
 187
 188         if (!dev->si_drv1)
 189                 return(ENXIO);
 190
 191         pti = dev->si_drv1;
 192         if (is_b)
 193                 tp = &pti->part2.nm_tty;
 194         else
 195                 tp = &pti->part1.nm_tty;
 196         GETPARTS(tp, ourpart, otherpart);
 197         tp2 = &otherpart->nm_tty;
 198         ourpart->modemsignals |= TIOCM_LE;
 199
 200         if ((tp->t_state & TS_ISOPEN) == 0) {
 201                 ttychars(tp);           /* Set up default chars */
 202                 tp->t_iflag = TTYDEF_IFLAG;
 203                 tp->t_oflag = TTYDEF_OFLAG;
 204                 tp->t_lflag = TTYDEF_LFLAG;
 205                 tp->t_cflag = TTYDEF_CFLAG;
 206                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 207         } else if (tp->t_state & TS_XCLUDE && suser(p)) {
 208                 return (EBUSY);
 209         } else if (pti->pt_prison != p->p_prison) {
 210                 return (EBUSY);
 211         }
 212
 213         /*
 214          * If the other side is open we have carrier
 215          */
 216         if (tp2->t_state & TS_ISOPEN) {
 217                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 218         }
 219
 220         /*
 221          * And the other side gets carrier as we are now open.
 222          */
 223         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
 224
 225         /* External processing makes no sense here */
 226         tp->t_lflag &= ~EXTPROC;
 227
 228         /*
 229          * Wait here if we don't have carrier.
 230          */
 231 #if 0
 232         while ((tp->t_state & TS_CARR_ON) == 0) {
 233                 if (flag & FNONBLOCK)
 234                         break;
 235                 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
 236                                  "nmdopn", 0);
 237                 if (error)
 238                         return (error);
 239         }
 240 #endif
 241
 242         /*
 243          * Give the line disciplin a chance to set this end up.
 244          */
 245         error = (*linesw[tp->t_line].l_open)(dev, tp);
 246
 247         /*
 248          * Wake up the other side.
 249          * Theoretically not needed.
 250          */
 251         ourpart->modemsignals |= TIOCM_DTR;
 252         nmdm_crossover(pti, ourpart, otherpart);
 253         if (error == 0)
 254                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
 255         return (error);
 256 }
 257
 258 static  int
 259 nmdmclose(dev, flag, mode, p)
 260         dev_t dev;
 261         int flag, mode;
 262         struct proc *p;
 263 {
 264         register struct tty *tp, *tp2;
 265         int err;
 266         struct softpart *ourpart, *otherpart;
 267
 268         /*
 269          * let the other end know that the game is up
 270          */
 271         tp = dev->si_tty;
 272         GETPARTS(tp, ourpart, otherpart);
 273         tp2 = &otherpart->nm_tty;
 274         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
 275
 276         /*
 277          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
 278          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 279          * l_modem()s that ignore carrier drop make no sense for nmdms but
 280          * may be in use because other parts of the line discipline make
 281          * sense for nmdms.  Recover by doing everything that a normal
 282          * ttymodem() would have done except for sending a SIGHUP.
 283          */
 284         if (tp2->t_state & TS_ISOPEN) {
 285                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 286                 tp2->t_state |= TS_ZOMBIE;
 287                 ttyflush(tp2, FREAD | FWRITE);
 288         }
 289
 290         err = (*linesw[tp->t_line].l_close)(tp, flag);
 291         ourpart->modemsignals &= ~TIOCM_DTR;
 292         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
 293         nmdmstop(tp, FREAD|FWRITE);
 294         (void) ttyclose(tp);
 295         return (err);
 296 }
 297
 298 static  int
 299 nmdmread(dev, uio, flag)
 300         dev_t dev;
 301         struct uio *uio;
 302         int flag;
 303 {
 304         int error = 0;
 305         struct tty *tp, *tp2;
 306         struct softpart *ourpart, *otherpart;
 307
 308         tp = dev->si_tty;
 309         GETPARTS(tp, ourpart, otherpart);
 310         tp2 = &otherpart->nm_tty;
 311
 312 #if 0
 313         if (tp2->t_state & TS_ISOPEN) {
 314                 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
 315                 wakeup_other(tp, FWRITE);
 316         } else {
 317                 if (flag & IO_NDELAY) {
 318                         return (EWOULDBLOCK);
 319                 }
 320                 error = tsleep(TSA_PTC_READ(tp),
 321                                 TTIPRI | PCATCH, "nmdout", 0);
 322                 }
 323         }
 324 #else
 325         if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
 326                 wakeup_other(tp, FWRITE);
 327 #endif
 328         return (error);
 329 }
 330
 331 /*
 332  * Write to pseudo-tty.
 333  * Wakeups of controlling tty will happen
 334  * indirectly, when tty driver calls nmdmstart.
 335  */
 336 static  int
 337 nmdmwrite(dev, uio, flag)
 338         dev_t dev;
 339         struct uio *uio;
 340         int flag;
 341 {
 342         register u_char *cp = 0;
 343         register int cc = 0;
 344         u_char locbuf[BUFSIZ];
 345         int cnt = 0;
 346         int error = 0;
 347         struct tty *tp1, *tp;
 348         struct softpart *ourpart, *otherpart;
 349
 350         tp1 = dev->si_tty;
 351         /*
 352          * Get the other tty struct.
 353          * basically we are writing into the INPUT side of the other device.
 354          */
 355         GETPARTS(tp1, ourpart, otherpart);
 356         tp = &otherpart->nm_tty;
 357
 358 again:
 359         if ((tp->t_state & TS_ISOPEN) == 0)
 360                 return (EIO);
 361         while (uio->uio_resid > 0 || cc > 0) {
 362                 /*
 363                  * Fill up the buffer if it's empty
 364                  */
 365                 if (cc == 0) {
 366                         cc = min(uio->uio_resid, BUFSIZ);
 367                         cp = locbuf;
 368                         error = uiomove((caddr_t)cp, cc, uio);
 369                         if (error)
 370                                 return (error);
 371                         /* check again for safety */
 372                         if ((tp->t_state & TS_ISOPEN) == 0) {
 373                                 /* adjust for data copied in but not written */
 374                                 uio->uio_resid += cc;
 375                                 return (EIO);
 376                         }
 377                 }
 378                 while (cc > 0) {
 379                         if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
 380                         && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
 381                                 /*
 382                                  * Come here to wait for space in outq,
 383                                  * or space in rawq, or an empty canq.
 384                                  */
 385                                 wakeup(TSA_HUP_OR_INPUT(tp));
 386                                 if ((tp->t_state & TS_CONNECTED) == 0) {
 387                                         /*
 388                                          * Data piled up because not connected.
 389                                          * Adjust for data copied in but
 390                                          * not written.
 391                                          */
 392                                         uio->uio_resid += cc;
 393                                         return (EIO);
 394                                 }
 395                                 if (flag & IO_NDELAY) {
 396                                         /*
 397                                          * Don't wait if asked not to.
 398                                          * Adjust for data copied in but
 399                                          * not written.
 400                                          */
 401                                         uio->uio_resid += cc;
 402                                         if (cnt == 0)
 403                                                 return (EWOULDBLOCK);
 404                                         return (0);
 405                                 }
 406                                 error = tsleep(TSA_PTC_WRITE(tp),
 407                                                 TTOPRI | PCATCH, "nmdout", 0);
 408                                 if (error) {
 409                                         /*
 410                                          * Tsleep returned (signal?).
 411                                          * Go find out what the user wants.
 412                                          * adjust for data copied in but
 413                                          * not written
 414                                          */
 415                                         uio->uio_resid += cc;
 416                                         return (error);
 417                                 }
 418                                 goto again;
 419                         }
 420                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
 421                         cnt++;
 422                         cc--;
 423                 }
 424                 cc = 0;
 425         }
 426         return (0);
 427 }
 428
 429 /*
 430  * Start output on pseudo-tty.
 431  * Wake up process selecting or sleeping for input from controlling tty.
 432  */
 433 static void
 434 nmdmstart(tp)
 435         struct tty *tp;
 436 {
 437         register struct nm_softc *pti = tp->t_dev->si_drv1;
 438
 439         if (tp->t_state & TS_TTSTOP)
 440                 return;
 441         pti->pt_flags &= ~PF_STOPPED;
 442         wakeup_other(tp, FREAD);
 443 }
 444
 445 /* Wakes up the OTHER tty;*/
 446 static void
 447 wakeup_other(tp, flag)
 448         struct tty *tp;
 449         int flag;
 450 {
 451         struct softpart *ourpart, *otherpart;
 452
 453         GETPARTS(tp, ourpart, otherpart);
 454         if (flag & FREAD) {
 455                 selwakeup(&otherpart->nm_tty.t_rsel);
 456                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
 457         }
 458         if (flag & FWRITE) {
 459                 selwakeup(&otherpart->nm_tty.t_wsel);
 460                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
 461         }
 462 }
 463
 464 static  void
 465 nmdmstop(tp, flush)
 466         register struct tty *tp;
 467         int flush;
 468 {
 469         struct nm_softc *pti = tp->t_dev->si_drv1;
 470         int flag;
 471
 472         /* note: FLUSHREAD and FLUSHWRITE already ok */
 473         if (flush == 0) {
 474                 flush = TIOCPKT_STOP;
 475                 pti->pt_flags |= PF_STOPPED;
 476         } else
 477                 pti->pt_flags &= ~PF_STOPPED;
 478         /* change of perspective */
 479         flag = 0;
 480         if (flush & FREAD)
 481                 flag |= FWRITE;
 482         if (flush & FWRITE)
 483                 flag |= FREAD;
 484         wakeup_other(tp, flag);
 485 }
 486
 487 /*ARGSUSED*/
 488 static  int
 489 nmdmioctl(dev, cmd, data, flag, p)
 490         dev_t dev;
 491         u_long cmd;
 492         caddr_t data;
 493         int flag;
 494         struct proc *p;
 495 {
 496         register struct tty *tp = dev->si_tty;
 497         struct nm_softc *pti = dev->si_drv1;
 498         int error, s;
 499         register struct tty *tp2;
 500         struct softpart *ourpart, *otherpart;
 501
 502         s = spltty();
 503         GETPARTS(tp, ourpart, otherpart);
 504         tp2 = &otherpart->nm_tty;
 505
 506         error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
 507         if (error == ENOIOCTL)
 508                  error = ttioctl(tp, cmd, data, flag);
 509         if (error == ENOIOCTL) {
 510                 switch (cmd) {
 511                 case TIOCSBRK:
 512                         otherpart->gotbreak = 1;
 513                         break;
 514                 case TIOCCBRK:
 515                         break;
 516                 case TIOCSDTR:
 517                         ourpart->modemsignals |= TIOCM_DTR;
 518                         break;
 519                 case TIOCCDTR:
 520                         ourpart->modemsignals &= TIOCM_DTR;
 521                         break;
 522                 case TIOCMSET:
 523                         ourpart->modemsignals = *(int *)data;
 524                         otherpart->modemsignals = *(int *)data;
 525                         break;
 526                 case TIOCMBIS:
 527                         ourpart->modemsignals |= *(int *)data;
 528                         break;
 529                 case TIOCMBIC:
 530                         ourpart->modemsignals &= ~(*(int *)data);
 531                         otherpart->modemsignals &= ~(*(int *)data);
 532                         break;
 533                 case TIOCMGET:
 534                         *(int *)data = ourpart->modemsignals;
 535                         break;
 536                 case TIOCMSDTRWAIT:
 537                         break;
 538                 case TIOCMGDTRWAIT:
 539                         *(int *)data = 0;
 540                         break;
 541                 case TIOCTIMESTAMP:
 542                 case TIOCDCDTIMESTAMP:
 543                 default:
 544                         splx(s);
 545                         error = ENOTTY;
 546                         return (error);
 547                 }
 548                 error = 0;
 549                 nmdm_crossover(pti, ourpart, otherpart);
 550         }
 551         splx(s);
 552         return (error);
 553 }
 554
 555 static void
 556 nmdm_crossover(struct nm_softc *pti,
 557                 struct softpart *ourpart,
 558                 struct softpart *otherpart)
 559 {
 560         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
 561         if (ourpart->modemsignals & TIOCM_RTS)
 562                 otherpart->modemsignals |= TIOCM_CTS;
 563         if (ourpart->modemsignals & TIOCM_DTR)
 564                 otherpart->modemsignals |= TIOCM_CAR;
 565 }
 566
 567
 568
 569 static void nmdm_drvinit __P((void *unused));
 570
 571 static void
 572 nmdm_drvinit(unused)
 573         void *unused;
 574 {
 575         cdevsw_add(&nmdm_cdevsw);
 576         /* XXX: Gross hack for DEVFS */
 577         nmdminit(0);
 578 }
 579
 580 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)