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 1.11 2005/06/16 16:31:34 joerg 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/thread2.h>
  48 #include <sys/tty.h>
  49 #include <sys/conf.h>
  50 #include <sys/fcntl.h>
  51 #include <sys/poll.h>
  52 #include <sys/kernel.h>
  53 #include <sys/vnode.h>
  54 #include <sys/signalvar.h>
  55 #include <sys/malloc.h>
  56
  57 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
  58
  59 static void nmdmstart (struct tty *tp);
  60 static void nmdmstop (struct tty *tp, int rw);
  61 static void wakeup_other (struct tty *tp, int flag);
  62 static void nmdminit (int n);
  63
  64 static  d_open_t        nmdmopen;
  65 static  d_close_t       nmdmclose;
  66 static  d_read_t        nmdmread;
  67 static  d_write_t       nmdmwrite;
  68 static  d_ioctl_t       nmdmioctl;
  69
  70 #define CDEV_MAJOR      18
  71 static struct cdevsw nmdm_cdevsw = {
  72         /* name */      "pts",
  73         /* maj */       CDEV_MAJOR,
  74         /* flags */     D_TTY,
  75         /* port */      NULL,
  76         /* clone */     NULL,
  77
  78         /* open */      nmdmopen,
  79         /* close */     nmdmclose,
  80         /* read */      nmdmread,
  81         /* write */     nmdmwrite,
  82         /* ioctl */     nmdmioctl,
  83         /* poll */      ttypoll,
  84         /* mmap */      nommap,
  85         /* strategy */  nostrategy,
  86         /* dump */      nodump,
  87         /* psize */     nopsize
  88 };
  89
  90 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
  91
  92 struct softpart {
  93         struct tty nm_tty;
  94         dev_t   dev;
  95         int     modemsignals;   /* bits defined in sys/ttycom.h */
  96         int     gotbreak;
  97 };
  98
  99 struct  nm_softc {
 100         int     pt_flags;
 101         struct softpart part1, part2;
 102         struct  prison *pt_prison;
 103 };
 104
 105 #define PF_STOPPED      0x10            /* user told stopped */
 106
 107 static void
 108 nmdm_crossover(struct nm_softc *pti,
 109                 struct softpart *ourpart,
 110                 struct softpart *otherpart);
 111
 112 #define GETPARTS(tp, ourpart, otherpart) \
 113 do {    \
 114         struct nm_softc *pti = tp->t_dev->si_drv1; \
 115         if (tp == &pti->part1.nm_tty) { \
 116                 ourpart = &pti->part1; \
 117                 otherpart = &pti->part2; \
 118         } else { \
 119                 ourpart = &pti->part2; \
 120                 otherpart = &pti->part1; \
 121         }  \
 122 } while (0)
 123
 124 /*
 125  * This function creates and initializes a pair of ttys.
 126  */
 127 static void
 128 nmdminit(n)
 129         int n;
 130 {
 131         dev_t dev1, dev2;
 132         struct nm_softc *pt;
 133
 134         /*
 135          * Simplified unit number, use low 8 bits of minor number
 136          * (remember, the minor number mask is 0xffff00ff).
 137          */
 138         if (n & ~0x7f)
 139                 return;
 140
 141         pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
 142         bzero(pt, sizeof(*pt));
 143         cdevsw_add(&nmdm_cdevsw, ~1, n << 1);
 144         pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n << 1,
 145             0, 0, 0666, "nmdm%dA", n);
 146         pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, (n << 1) + 1,
 147             0, 0, 0666, "nmdm%dB", n);
 148
 149         dev1->si_drv1 = dev2->si_drv1 = pt;
 150         dev1->si_tty = &pt->part1.nm_tty;
 151         dev2->si_tty = &pt->part2.nm_tty;
 152         ttyregister(&pt->part1.nm_tty);
 153         ttyregister(&pt->part2.nm_tty);
 154         pt->part1.nm_tty.t_oproc = nmdmstart;
 155         pt->part2.nm_tty.t_oproc = nmdmstart;
 156         pt->part1.nm_tty.t_stop = nmdmstop;
 157         pt->part2.nm_tty.t_dev = dev1;
 158         pt->part1.nm_tty.t_dev = dev2;
 159         pt->part2.nm_tty.t_stop = nmdmstop;
 160 }
 161
 162 /*ARGSUSED*/
 163 static  int
 164 nmdmopen(dev_t dev, int flag, int devtype, struct thread *td)
 165 {
 166         struct proc *p = td->td_proc;
 167         struct tty *tp, *tp2;
 168         int error;
 169         int minr;
 170 #if 0
 171         dev_t nextdev;
 172 #endif
 173         struct nm_softc *pti;
 174         int is_b;
 175         int     pair;
 176         struct  softpart *ourpart, *otherpart;
 177
 178         KKASSERT(p != NULL);
 179
 180         minr = lminor(dev);
 181         pair = minr >> 1;
 182         is_b = minr & 1;
 183
 184 #if 0
 185         /*
 186          * XXX: Gross hack for DEVFS:
 187          * If we openned this device, ensure we have the
 188          * next one too, so people can open it.
 189          */
 190         if (pair < 127) {
 191                 nextdev = makedev(major(dev), (pair+pair) + 1);
 192                 if (!nextdev->si_drv1) {
 193                         nmdminit(pair + 1);
 194                 }
 195         }
 196 #endif
 197         if (!dev->si_drv1)
 198                 nmdminit(pair);
 199
 200         if (!dev->si_drv1)
 201                 return(ENXIO);
 202
 203         pti = dev->si_drv1;
 204         if (is_b)
 205                 tp = &pti->part2.nm_tty;
 206         else
 207                 tp = &pti->part1.nm_tty;
 208         GETPARTS(tp, ourpart, otherpart);
 209         tp2 = &otherpart->nm_tty;
 210         ourpart->modemsignals |= TIOCM_LE;
 211
 212         if ((tp->t_state & TS_ISOPEN) == 0) {
 213                 ttychars(tp);           /* Set up default chars */
 214                 tp->t_iflag = TTYDEF_IFLAG;
 215                 tp->t_oflag = TTYDEF_OFLAG;
 216                 tp->t_lflag = TTYDEF_LFLAG;
 217                 tp->t_cflag = TTYDEF_CFLAG;
 218                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 219         } else if (tp->t_state & TS_XCLUDE && suser(td)) {
 220                 return (EBUSY);
 221         } else if (pti->pt_prison != p->p_ucred->cr_prison) {
 222                 return (EBUSY);
 223         }
 224
 225         /*
 226          * If the other side is open we have carrier
 227          */
 228         if (tp2->t_state & TS_ISOPEN) {
 229                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 230         }
 231
 232         /*
 233          * And the other side gets carrier as we are now open.
 234          */
 235         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
 236
 237         /* External processing makes no sense here */
 238         tp->t_lflag &= ~EXTPROC;
 239
 240         /*
 241          * Wait here if we don't have carrier.
 242          */
 243 #if 0
 244         while ((tp->t_state & TS_CARR_ON) == 0) {
 245                 if (flag & FNONBLOCK)
 246                         break;
 247                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0);
 248                 if (error)
 249                         return (error);
 250         }
 251 #endif
 252
 253         /*
 254          * Give the line disciplin a chance to set this end up.
 255          */
 256         error = (*linesw[tp->t_line].l_open)(dev, tp);
 257
 258         /*
 259          * Wake up the other side.
 260          * Theoretically not needed.
 261          */
 262         ourpart->modemsignals |= TIOCM_DTR;
 263         nmdm_crossover(pti, ourpart, otherpart);
 264         if (error == 0)
 265                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
 266         return (error);
 267 }
 268
 269 static  int
 270 nmdmclose(dev_t dev, int flag, int mode, struct thread *td)
 271 {
 272         struct tty *tp, *tp2;
 273         int err;
 274         struct softpart *ourpart, *otherpart;
 275
 276         /*
 277          * let the other end know that the game is up
 278          */
 279         tp = dev->si_tty;
 280         GETPARTS(tp, ourpart, otherpart);
 281         tp2 = &otherpart->nm_tty;
 282         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
 283
 284         /*
 285          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
 286          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 287          * l_modem()s that ignore carrier drop make no sense for nmdms but
 288          * may be in use because other parts of the line discipline make
 289          * sense for nmdms.  Recover by doing everything that a normal
 290          * ttymodem() would have done except for sending a SIGHUP.
 291          */
 292         if (tp2->t_state & TS_ISOPEN) {
 293                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 294                 tp2->t_state |= TS_ZOMBIE;
 295                 ttyflush(tp2, FREAD | FWRITE);
 296         }
 297
 298         err = (*linesw[tp->t_line].l_close)(tp, flag);
 299         ourpart->modemsignals &= ~TIOCM_DTR;
 300         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
 301         nmdmstop(tp, FREAD|FWRITE);
 302         (void) ttyclose(tp);
 303         return (err);
 304 }
 305
 306 static  int
 307 nmdmread(dev, uio, flag)
 308         dev_t dev;
 309         struct uio *uio;
 310         int flag;
 311 {
 312         int error = 0;
 313         struct tty *tp, *tp2;
 314         struct softpart *ourpart, *otherpart;
 315
 316         tp = dev->si_tty;
 317         GETPARTS(tp, ourpart, otherpart);
 318         tp2 = &otherpart->nm_tty;
 319
 320 #if 0
 321         if (tp2->t_state & TS_ISOPEN) {
 322                 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
 323                 wakeup_other(tp, FWRITE);
 324         } else {
 325                 if (flag & IO_NDELAY) {
 326                         return (EWOULDBLOCK);
 327                 }
 328                 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0);
 329                 }
 330         }
 331 #else
 332         if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
 333                 wakeup_other(tp, FWRITE);
 334 #endif
 335         return (error);
 336 }
 337
 338 /*
 339  * Write to pseudo-tty.
 340  * Wakeups of controlling tty will happen
 341  * indirectly, when tty driver calls nmdmstart.
 342  */
 343 static  int
 344 nmdmwrite(dev, uio, flag)
 345         dev_t dev;
 346         struct uio *uio;
 347         int flag;
 348 {
 349         u_char *cp = 0;
 350         int cc = 0;
 351         u_char locbuf[BUFSIZ];
 352         int cnt = 0;
 353         int error = 0;
 354         struct tty *tp1, *tp;
 355         struct softpart *ourpart, *otherpart;
 356
 357         tp1 = dev->si_tty;
 358         /*
 359          * Get the other tty struct.
 360          * basically we are writing into the INPUT side of the other device.
 361          */
 362         GETPARTS(tp1, ourpart, otherpart);
 363         tp = &otherpart->nm_tty;
 364
 365 again:
 366         if ((tp->t_state & TS_ISOPEN) == 0)
 367                 return (EIO);
 368         while (uio->uio_resid > 0 || cc > 0) {
 369                 /*
 370                  * Fill up the buffer if it's empty
 371                  */
 372                 if (cc == 0) {
 373                         cc = min(uio->uio_resid, BUFSIZ);
 374                         cp = locbuf;
 375                         error = uiomove((caddr_t)cp, cc, uio);
 376                         if (error)
 377                                 return (error);
 378                         /* check again for safety */
 379                         if ((tp->t_state & TS_ISOPEN) == 0) {
 380                                 /* adjust for data copied in but not written */
 381                                 uio->uio_resid += cc;
 382                                 return (EIO);
 383                         }
 384                 }
 385                 while (cc > 0) {
 386                         if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
 387                         && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
 388                                 /*
 389                                  * Come here to wait for space in outq,
 390                                  * or space in rawq, or an empty canq.
 391                                  */
 392                                 wakeup(TSA_HUP_OR_INPUT(tp));
 393                                 if ((tp->t_state & TS_CONNECTED) == 0) {
 394                                         /*
 395                                          * Data piled up because not connected.
 396                                          * Adjust for data copied in but
 397                                          * not written.
 398                                          */
 399                                         uio->uio_resid += cc;
 400                                         return (EIO);
 401                                 }
 402                                 if (flag & IO_NDELAY) {
 403                                         /*
 404                                          * Don't wait if asked not to.
 405                                          * Adjust for data copied in but
 406                                          * not written.
 407                                          */
 408                                         uio->uio_resid += cc;
 409                                         if (cnt == 0)
 410                                                 return (EWOULDBLOCK);
 411                                         return (0);
 412                                 }
 413                                 error = tsleep(TSA_PTC_WRITE(tp),
 414                                                 PCATCH, "nmdout", 0);
 415                                 if (error) {
 416                                         /*
 417                                          * Tsleep returned (signal?).
 418                                          * Go find out what the user wants.
 419                                          * adjust for data copied in but
 420                                          * not written
 421                                          */
 422                                         uio->uio_resid += cc;
 423                                         return (error);
 424                                 }
 425                                 goto again;
 426                         }
 427                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
 428                         cnt++;
 429                         cc--;
 430                 }
 431                 cc = 0;
 432         }
 433         return (0);
 434 }
 435
 436 /*
 437  * Start output on pseudo-tty.
 438  * Wake up process selecting or sleeping for input from controlling tty.
 439  */
 440 static void
 441 nmdmstart(tp)
 442         struct tty *tp;
 443 {
 444         struct nm_softc *pti = tp->t_dev->si_drv1;
 445
 446         if (tp->t_state & TS_TTSTOP)
 447                 return;
 448         pti->pt_flags &= ~PF_STOPPED;
 449         wakeup_other(tp, FREAD);
 450 }
 451
 452 /* Wakes up the OTHER tty;*/
 453 static void
 454 wakeup_other(tp, flag)
 455         struct tty *tp;
 456         int flag;
 457 {
 458         struct softpart *ourpart, *otherpart;
 459
 460         GETPARTS(tp, ourpart, otherpart);
 461         if (flag & FREAD) {
 462                 selwakeup(&otherpart->nm_tty.t_rsel);
 463                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
 464         }
 465         if (flag & FWRITE) {
 466                 selwakeup(&otherpart->nm_tty.t_wsel);
 467                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
 468         }
 469 }
 470
 471 static  void
 472 nmdmstop(tp, flush)
 473         struct tty *tp;
 474         int flush;
 475 {
 476         struct nm_softc *pti = tp->t_dev->si_drv1;
 477         int flag;
 478
 479         /* note: FLUSHREAD and FLUSHWRITE already ok */
 480         if (flush == 0) {
 481                 flush = TIOCPKT_STOP;
 482                 pti->pt_flags |= PF_STOPPED;
 483         } else
 484                 pti->pt_flags &= ~PF_STOPPED;
 485         /* change of perspective */
 486         flag = 0;
 487         if (flush & FREAD)
 488                 flag |= FWRITE;
 489         if (flush & FWRITE)
 490                 flag |= FREAD;
 491         wakeup_other(tp, flag);
 492 }
 493
 494 /*ARGSUSED*/
 495 static  int
 496 nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 497 {
 498         struct tty *tp = dev->si_tty;
 499         struct nm_softc *pti = dev->si_drv1;
 500         int error;
 501         struct tty *tp2;
 502         struct softpart *ourpart, *otherpart;
 503
 504         crit_enter();
 505         GETPARTS(tp, ourpart, otherpart);
 506         tp2 = &otherpart->nm_tty;
 507
 508         error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
 509         if (error == ENOIOCTL)
 510                  error = ttioctl(tp, cmd, data, flag);
 511         if (error == ENOIOCTL) {
 512                 switch (cmd) {
 513                 case TIOCSBRK:
 514                         otherpart->gotbreak = 1;
 515                         break;
 516                 case TIOCCBRK:
 517                         break;
 518                 case TIOCSDTR:
 519                         ourpart->modemsignals |= TIOCM_DTR;
 520                         break;
 521                 case TIOCCDTR:
 522                         ourpart->modemsignals &= TIOCM_DTR;
 523                         break;
 524                 case TIOCMSET:
 525                         ourpart->modemsignals = *(int *)data;
 526                         otherpart->modemsignals = *(int *)data;
 527                         break;
 528                 case TIOCMBIS:
 529                         ourpart->modemsignals |= *(int *)data;
 530                         break;
 531                 case TIOCMBIC:
 532                         ourpart->modemsignals &= ~(*(int *)data);
 533                         otherpart->modemsignals &= ~(*(int *)data);
 534                         break;
 535                 case TIOCMGET:
 536                         *(int *)data = ourpart->modemsignals;
 537                         break;
 538                 case TIOCMSDTRWAIT:
 539                         break;
 540                 case TIOCMGDTRWAIT:
 541                         *(int *)data = 0;
 542                         break;
 543                 case TIOCTIMESTAMP:
 544                 case TIOCDCDTIMESTAMP:
 545                 default:
 546                         crit_exit();
 547                         error = ENOTTY;
 548                         return (error);
 549                 }
 550                 error = 0;
 551                 nmdm_crossover(pti, ourpart, otherpart);
 552         }
 553         crit_exit();
 554         return (error);
 555 }
 556
 557 static void
 558 nmdm_crossover(struct nm_softc *pti,
 559                 struct softpart *ourpart,
 560                 struct softpart *otherpart)
 561 {
 562         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
 563         if (ourpart->modemsignals & TIOCM_RTS)
 564                 otherpart->modemsignals |= TIOCM_CTS;
 565         if (ourpart->modemsignals & TIOCM_DTR)
 566                 otherpart->modemsignals |= TIOCM_CAR;
 567 }
 568
 569
 570
 571 static void nmdm_drvinit (void *unused);
 572
 573 static void
 574 nmdm_drvinit(unused)
 575         void *unused;
 576 {
 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)