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  * $DragonFly: src/sys/dev/misc/nmdm/nmdm.c,v 1.2 2003/06/17 04:28:28 dillon Exp $
  35  */
  36
  37 /*
  38  * Pseudo-nulmodem Driver
  39  */
  40 #include "opt_compat.h"
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  44 #include <sys/ioctl_compat.h>
  45 #endif
  46 #include <sys/proc.h>
  47 #include <sys/tty.h>
  48 #include <sys/conf.h>
  49 #include <sys/fcntl.h>
  50 #include <sys/poll.h>
  51 #include <sys/kernel.h>
  52 #include <sys/vnode.h>
  53 #include <sys/signalvar.h>
  54 #include <sys/malloc.h>
  55
  56 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
  57
  58 static void nmdmstart __P((struct tty *tp));
  59 static void nmdmstop __P((struct tty *tp, int rw));
  60 static void wakeup_other __P((struct tty *tp, int flag));
  61 static void nmdminit __P((int n));
  62
  63 static  d_open_t        nmdmopen;
  64 static  d_close_t       nmdmclose;
  65 static  d_read_t        nmdmread;
  66 static  d_write_t       nmdmwrite;
  67 static  d_ioctl_t       nmdmioctl;
  68
  69 #define CDEV_MAJOR      18
  70 static struct cdevsw nmdm_cdevsw = {
  71         /* open */      nmdmopen,
  72         /* close */     nmdmclose,
  73         /* read */      nmdmread,
  74         /* write */     nmdmwrite,
  75         /* ioctl */     nmdmioctl,
  76         /* poll */      ttypoll,
  77         /* mmap */      nommap,
  78         /* strategy */  nostrategy,
  79         /* name */      "pts",
  80         /* maj */       CDEV_MAJOR,
  81         /* dump */      nodump,
  82         /* psize */     nopsize,
  83         /* flags */     D_TTY,
  84         /* bmaj */      -1
  85 };
  86
  87 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
  88
  89 struct softpart {
  90         struct tty nm_tty;
  91         dev_t   dev;
  92         int     modemsignals;   /* bits defined in sys/ttycom.h */
  93         int     gotbreak;
  94 };
  95
  96 struct  nm_softc {
  97         int     pt_flags;
  98         struct softpart part1, part2;
  99         struct  prison *pt_prison;
 100 };
 101
 102 #define PF_STOPPED      0x10            /* user told stopped */
 103
 104 static void
 105 nmdm_crossover(struct nm_softc *pti,
 106                 struct softpart *ourpart,
 107                 struct softpart *otherpart);
 108
 109 #define GETPARTS(tp, ourpart, otherpart) \
 110 do {    \
 111         struct nm_softc *pti = tp->t_dev->si_drv1; \
 112         if (tp == &pti->part1.nm_tty) { \
 113                 ourpart = &pti->part1; \
 114                 otherpart = &pti->part2; \
 115         } else { \
 116                 ourpart = &pti->part2; \
 117                 otherpart = &pti->part1; \
 118         }  \
 119 } while (0)
 120
 121 /*
 122  * This function creates and initializes a pair of ttys.
 123  */
 124 static void
 125 nmdminit(n)
 126         int n;
 127 {
 128         dev_t dev1, dev2;
 129         struct nm_softc *pt;
 130
 131         /* For now we only map the lower 8 bits of the minor */
 132         if (n & ~0xff)
 133                 return;
 134
 135         pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
 136         bzero(pt, sizeof(*pt));
 137         pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n,
 138             0, 0, 0666, "nmdm%dA", n);
 139         pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1,
 140             0, 0, 0666, "nmdm%dB", n);
 141
 142         dev1->si_drv1 = dev2->si_drv1 = pt;
 143         dev1->si_tty = &pt->part1.nm_tty;
 144         dev2->si_tty = &pt->part2.nm_tty;
 145         ttyregister(&pt->part1.nm_tty);
 146         ttyregister(&pt->part2.nm_tty);
 147         pt->part1.nm_tty.t_oproc = nmdmstart;
 148         pt->part2.nm_tty.t_oproc = nmdmstart;
 149         pt->part1.nm_tty.t_stop = nmdmstop;
 150         pt->part2.nm_tty.t_dev = dev1;
 151         pt->part1.nm_tty.t_dev = dev2;
 152         pt->part2.nm_tty.t_stop = nmdmstop;
 153 }
 154
 155 /*ARGSUSED*/
 156 static  int
 157 nmdmopen(dev, flag, devtype, p)
 158         dev_t dev;
 159         int flag, devtype;
 160         struct proc *p;
 161 {
 162         register struct tty *tp, *tp2;
 163         int error;
 164         int minr;
 165         dev_t nextdev;
 166         struct nm_softc *pti;
 167         int is_b;
 168         int     pair;
 169         struct  softpart *ourpart, *otherpart;
 170
 171         /*
 172          * XXX: Gross hack for DEVFS:
 173          * If we openned this device, ensure we have the
 174          * next one too, so people can open it.
 175          */
 176         minr = lminor(dev);
 177         pair = minr >> 1;
 178         is_b = minr & 1;
 179
 180         if (pair < 127) {
 181                 nextdev = makedev(major(dev), (pair+pair) + 1);
 182                 if (!nextdev->si_drv1) {
 183                         nmdminit(pair + 1);
 184                 }
 185         }
 186         if (!dev->si_drv1)
 187                 nmdminit(pair);
 188
 189         if (!dev->si_drv1)
 190                 return(ENXIO);
 191
 192         pti = dev->si_drv1;
 193         if (is_b)
 194                 tp = &pti->part2.nm_tty;
 195         else
 196                 tp = &pti->part1.nm_tty;
 197         GETPARTS(tp, ourpart, otherpart);
 198         tp2 = &otherpart->nm_tty;
 199         ourpart->modemsignals |= TIOCM_LE;
 200
 201         if ((tp->t_state & TS_ISOPEN) == 0) {
 202                 ttychars(tp);           /* Set up default chars */
 203                 tp->t_iflag = TTYDEF_IFLAG;
 204                 tp->t_oflag = TTYDEF_OFLAG;
 205                 tp->t_lflag = TTYDEF_LFLAG;
 206                 tp->t_cflag = TTYDEF_CFLAG;
 207                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 208         } else if (tp->t_state & TS_XCLUDE && suser(p)) {
 209                 return (EBUSY);
 210         } else if (pti->pt_prison != p->p_prison) {
 211                 return (EBUSY);
 212         }
 213
 214         /*
 215          * If the other side is open we have carrier
 216          */
 217         if (tp2->t_state & TS_ISOPEN) {
 218                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 219         }
 220
 221         /*
 222          * And the other side gets carrier as we are now open.
 223          */
 224         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
 225
 226         /* External processing makes no sense here */
 227         tp->t_lflag &= ~EXTPROC;
 228
 229         /*
 230          * Wait here if we don't have carrier.
 231          */
 232 #if 0
 233         while ((tp->t_state & TS_CARR_ON) == 0) {
 234                 if (flag & FNONBLOCK)
 235                         break;
 236                 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
 237                                  "nmdopn", 0);
 238                 if (error)
 239                         return (error);
 240         }
 241 #endif
 242
 243         /*
 244          * Give the line disciplin a chance to set this end up.
 245          */
 246         error = (*linesw[tp->t_line].l_open)(dev, tp);
 247
 248         /*
 249          * Wake up the other side.
 250          * Theoretically not needed.
 251          */
 252         ourpart->modemsignals |= TIOCM_DTR;
 253         nmdm_crossover(pti, ourpart, otherpart);
 254         if (error == 0)
 255                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
 256         return (error);
 257 }
 258
 259 static  int
 260 nmdmclose(dev, flag, mode, p)
 261         dev_t dev;
 262         int flag, mode;
 263         struct proc *p;
 264 {
 265         register struct tty *tp, *tp2;
 266         int err;
 267         struct softpart *ourpart, *otherpart;
 268
 269         /*
 270          * let the other end know that the game is up
 271          */
 272         tp = dev->si_tty;
 273         GETPARTS(tp, ourpart, otherpart);
 274         tp2 = &otherpart->nm_tty;
 275         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
 276
 277         /*
 278          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
 279          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 280          * l_modem()s that ignore carrier drop make no sense for nmdms but
 281          * may be in use because other parts of the line discipline make
 282          * sense for nmdms.  Recover by doing everything that a normal
 283          * ttymodem() would have done except for sending a SIGHUP.
 284          */
 285         if (tp2->t_state & TS_ISOPEN) {
 286                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 287                 tp2->t_state |= TS_ZOMBIE;
 288                 ttyflush(tp2, FREAD | FWRITE);
 289         }
 290
 291         err = (*linesw[tp->t_line].l_close)(tp, flag);
 292         ourpart->modemsignals &= ~TIOCM_DTR;
 293         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
 294         nmdmstop(tp, FREAD|FWRITE);
 295         (void) ttyclose(tp);
 296         return (err);
 297 }
 298
 299 static  int
 300 nmdmread(dev, uio, flag)
 301         dev_t dev;
 302         struct uio *uio;
 303         int flag;
 304 {
 305         int error = 0;
 306         struct tty *tp, *tp2;
 307         struct softpart *ourpart, *otherpart;
 308
 309         tp = dev->si_tty;
 310         GETPARTS(tp, ourpart, otherpart);
 311         tp2 = &otherpart->nm_tty;
 312
 313 #if 0
 314         if (tp2->t_state & TS_ISOPEN) {
 315                 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
 316                 wakeup_other(tp, FWRITE);
 317         } else {
 318                 if (flag & IO_NDELAY) {
 319                         return (EWOULDBLOCK);
 320                 }
 321                 error = tsleep(TSA_PTC_READ(tp),
 322                                 TTIPRI | PCATCH, "nmdout", 0);
 323                 }
 324         }
 325 #else
 326         if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
 327                 wakeup_other(tp, FWRITE);
 328 #endif
 329         return (error);
 330 }
 331
 332 /*
 333  * Write to pseudo-tty.
 334  * Wakeups of controlling tty will happen
 335  * indirectly, when tty driver calls nmdmstart.
 336  */
 337 static  int
 338 nmdmwrite(dev, uio, flag)
 339         dev_t dev;
 340         struct uio *uio;
 341         int flag;
 342 {
 343         register u_char *cp = 0;
 344         register int cc = 0;
 345         u_char locbuf[BUFSIZ];
 346         int cnt = 0;
 347         int error = 0;
 348         struct tty *tp1, *tp;
 349         struct softpart *ourpart, *otherpart;
 350
 351         tp1 = dev->si_tty;
 352         /*
 353          * Get the other tty struct.
 354          * basically we are writing into the INPUT side of the other device.
 355          */
 356         GETPARTS(tp1, ourpart, otherpart);
 357         tp = &otherpart->nm_tty;
 358
 359 again:
 360         if ((tp->t_state & TS_ISOPEN) == 0)
 361                 return (EIO);
 362         while (uio->uio_resid > 0 || cc > 0) {
 363                 /*
 364                  * Fill up the buffer if it's empty
 365                  */
 366                 if (cc == 0) {
 367                         cc = min(uio->uio_resid, BUFSIZ);
 368                         cp = locbuf;
 369                         error = uiomove((caddr_t)cp, cc, uio);
 370                         if (error)
 371                                 return (error);
 372                         /* check again for safety */
 373                         if ((tp->t_state & TS_ISOPEN) == 0) {
 374                                 /* adjust for data copied in but not written */
 375                                 uio->uio_resid += cc;
 376                                 return (EIO);
 377                         }
 378                 }
 379                 while (cc > 0) {
 380                         if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
 381                         && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
 382                                 /*
 383                                  * Come here to wait for space in outq,
 384                                  * or space in rawq, or an empty canq.
 385                                  */
 386                                 wakeup(TSA_HUP_OR_INPUT(tp));
 387                                 if ((tp->t_state & TS_CONNECTED) == 0) {
 388                                         /*
 389                                          * Data piled up because not connected.
 390                                          * Adjust for data copied in but
 391                                          * not written.
 392                                          */
 393                                         uio->uio_resid += cc;
 394                                         return (EIO);
 395                                 }
 396                                 if (flag & IO_NDELAY) {
 397                                         /*
 398                                          * Don't wait if asked not to.
 399                                          * Adjust for data copied in but
 400                                          * not written.
 401                                          */
 402                                         uio->uio_resid += cc;
 403                                         if (cnt == 0)
 404                                                 return (EWOULDBLOCK);
 405                                         return (0);
 406                                 }
 407                                 error = tsleep(TSA_PTC_WRITE(tp),
 408                                                 TTOPRI | PCATCH, "nmdout", 0);
 409                                 if (error) {
 410                                         /*
 411                                          * Tsleep returned (signal?).
 412                                          * Go find out what the user wants.
 413                                          * adjust for data copied in but
 414                                          * not written
 415                                          */
 416                                         uio->uio_resid += cc;
 417                                         return (error);
 418                                 }
 419                                 goto again;
 420                         }
 421                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
 422                         cnt++;
 423                         cc--;
 424                 }
 425                 cc = 0;
 426         }
 427         return (0);
 428 }
 429
 430 /*
 431  * Start output on pseudo-tty.
 432  * Wake up process selecting or sleeping for input from controlling tty.
 433  */
 434 static void
 435 nmdmstart(tp)
 436         struct tty *tp;
 437 {
 438         register struct nm_softc *pti = tp->t_dev->si_drv1;
 439
 440         if (tp->t_state & TS_TTSTOP)
 441                 return;
 442         pti->pt_flags &= ~PF_STOPPED;
 443         wakeup_other(tp, FREAD);
 444 }
 445
 446 /* Wakes up the OTHER tty;*/
 447 static void
 448 wakeup_other(tp, flag)
 449         struct tty *tp;
 450         int flag;
 451 {
 452         struct softpart *ourpart, *otherpart;
 453
 454         GETPARTS(tp, ourpart, otherpart);
 455         if (flag & FREAD) {
 456                 selwakeup(&otherpart->nm_tty.t_rsel);
 457                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
 458         }
 459         if (flag & FWRITE) {
 460                 selwakeup(&otherpart->nm_tty.t_wsel);
 461                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
 462         }
 463 }
 464
 465 static  void
 466 nmdmstop(tp, flush)
 467         register struct tty *tp;
 468         int flush;
 469 {
 470         struct nm_softc *pti = tp->t_dev->si_drv1;
 471         int flag;
 472
 473         /* note: FLUSHREAD and FLUSHWRITE already ok */
 474         if (flush == 0) {
 475                 flush = TIOCPKT_STOP;
 476                 pti->pt_flags |= PF_STOPPED;
 477         } else
 478                 pti->pt_flags &= ~PF_STOPPED;
 479         /* change of perspective */
 480         flag = 0;
 481         if (flush & FREAD)
 482                 flag |= FWRITE;
 483         if (flush & FWRITE)
 484                 flag |= FREAD;
 485         wakeup_other(tp, flag);
 486 }
 487
 488 /*ARGSUSED*/
 489 static  int
 490 nmdmioctl(dev, cmd, data, flag, p)
 491         dev_t dev;
 492         u_long cmd;
 493         caddr_t data;
 494         int flag;
 495         struct proc *p;
 496 {
 497         register struct tty *tp = dev->si_tty;
 498         struct nm_softc *pti = dev->si_drv1;
 499         int error, s;
 500         register struct tty *tp2;
 501         struct softpart *ourpart, *otherpart;
 502
 503         s = spltty();
 504         GETPARTS(tp, ourpart, otherpart);
 505         tp2 = &otherpart->nm_tty;
 506
 507         error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
 508         if (error == ENOIOCTL)
 509                  error = ttioctl(tp, cmd, data, flag);
 510         if (error == ENOIOCTL) {
 511                 switch (cmd) {
 512                 case TIOCSBRK:
 513                         otherpart->gotbreak = 1;
 514                         break;
 515                 case TIOCCBRK:
 516                         break;
 517                 case TIOCSDTR:
 518                         ourpart->modemsignals |= TIOCM_DTR;
 519                         break;
 520                 case TIOCCDTR:
 521                         ourpart->modemsignals &= TIOCM_DTR;
 522                         break;
 523                 case TIOCMSET:
 524                         ourpart->modemsignals = *(int *)data;
 525                         otherpart->modemsignals = *(int *)data;
 526                         break;
 527                 case TIOCMBIS:
 528                         ourpart->modemsignals |= *(int *)data;
 529                         break;
 530                 case TIOCMBIC:
 531                         ourpart->modemsignals &= ~(*(int *)data);
 532                         otherpart->modemsignals &= ~(*(int *)data);
 533                         break;
 534                 case TIOCMGET:
 535                         *(int *)data = ourpart->modemsignals;
 536                         break;
 537                 case TIOCMSDTRWAIT:
 538                         break;
 539                 case TIOCMGDTRWAIT:
 540                         *(int *)data = 0;
 541                         break;
 542                 case TIOCTIMESTAMP:
 543                 case TIOCDCDTIMESTAMP:
 544                 default:
 545                         splx(s);
 546                         error = ENOTTY;
 547                         return (error);
 548                 }
 549                 error = 0;
 550                 nmdm_crossover(pti, ourpart, otherpart);
 551         }
 552         splx(s);
 553         return (error);
 554 }
 555
 556 static void
 557 nmdm_crossover(struct nm_softc *pti,
 558                 struct softpart *ourpart,
 559                 struct softpart *otherpart)
 560 {
 561         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
 562         if (ourpart->modemsignals & TIOCM_RTS)
 563                 otherpart->modemsignals |= TIOCM_CTS;
 564         if (ourpart->modemsignals & TIOCM_DTR)
 565                 otherpart->modemsignals |= TIOCM_CAR;
 566 }
 567
 568
 569
 570 static void nmdm_drvinit __P((void *unused));
 571
 572 static void
 573 nmdm_drvinit(unused)
 574         void *unused;
 575 {
 576         cdevsw_add(&nmdm_cdevsw);
 577         /* XXX: Gross hack for DEVFS */
 578         nmdminit(0);
 579 }
 580
 581 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)