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 1.12 2005/12/11 01:54:08 swildner 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(int n)
 129 {
 130         dev_t dev1, dev2;
 131         struct nm_softc *pt;
 132
 133         /*
 134          * Simplified unit number, use low 8 bits of minor number
 135          * (remember, the minor number mask is 0xffff00ff).
 136          */
 137         if (n & ~0x7f)
 138                 return;
 139
 140         pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
 141         bzero(pt, sizeof(*pt));
 142         cdevsw_add(&nmdm_cdevsw, ~1, n << 1);
 143         pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n << 1,
 144             0, 0, 0666, "nmdm%dA", n);
 145         pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, (n << 1) + 1,
 146             0, 0, 0666, "nmdm%dB", n);
 147
 148         dev1->si_drv1 = dev2->si_drv1 = pt;
 149         dev1->si_tty = &pt->part1.nm_tty;
 150         dev2->si_tty = &pt->part2.nm_tty;
 151         ttyregister(&pt->part1.nm_tty);
 152         ttyregister(&pt->part2.nm_tty);
 153         pt->part1.nm_tty.t_oproc = nmdmstart;
 154         pt->part2.nm_tty.t_oproc = nmdmstart;
 155         pt->part1.nm_tty.t_stop = nmdmstop;
 156         pt->part2.nm_tty.t_dev = dev1;
 157         pt->part1.nm_tty.t_dev = dev2;
 158         pt->part2.nm_tty.t_stop = nmdmstop;
 159 }
 160
 161 /*ARGSUSED*/
 162 static  int
 163 nmdmopen(dev_t dev, int flag, int devtype, struct thread *td)
 164 {
 165         struct proc *p = td->td_proc;
 166         struct tty *tp, *tp2;
 167         int error;
 168         int minr;
 169 #if 0
 170         dev_t nextdev;
 171 #endif
 172         struct nm_softc *pti;
 173         int is_b;
 174         int     pair;
 175         struct  softpart *ourpart, *otherpart;
 176
 177         KKASSERT(p != NULL);
 178
 179         minr = lminor(dev);
 180         pair = minr >> 1;
 181         is_b = minr & 1;
 182
 183 #if 0
 184         /*
 185          * XXX: Gross hack for DEVFS:
 186          * If we openned this device, ensure we have the
 187          * next one too, so people can open it.
 188          */
 189         if (pair < 127) {
 190                 nextdev = makedev(major(dev), (pair+pair) + 1);
 191                 if (!nextdev->si_drv1) {
 192                         nmdminit(pair + 1);
 193                 }
 194         }
 195 #endif
 196         if (!dev->si_drv1)
 197                 nmdminit(pair);
 198
 199         if (!dev->si_drv1)
 200                 return(ENXIO);
 201
 202         pti = dev->si_drv1;
 203         if (is_b)
 204                 tp = &pti->part2.nm_tty;
 205         else
 206                 tp = &pti->part1.nm_tty;
 207         GETPARTS(tp, ourpart, otherpart);
 208         tp2 = &otherpart->nm_tty;
 209         ourpart->modemsignals |= TIOCM_LE;
 210
 211         if ((tp->t_state & TS_ISOPEN) == 0) {
 212                 ttychars(tp);           /* Set up default chars */
 213                 tp->t_iflag = TTYDEF_IFLAG;
 214                 tp->t_oflag = TTYDEF_OFLAG;
 215                 tp->t_lflag = TTYDEF_LFLAG;
 216                 tp->t_cflag = TTYDEF_CFLAG;
 217                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 218         } else if (tp->t_state & TS_XCLUDE && suser(td)) {
 219                 return (EBUSY);
 220         } else if (pti->pt_prison != p->p_ucred->cr_prison) {
 221                 return (EBUSY);
 222         }
 223
 224         /*
 225          * If the other side is open we have carrier
 226          */
 227         if (tp2->t_state & TS_ISOPEN) {
 228                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 229         }
 230
 231         /*
 232          * And the other side gets carrier as we are now open.
 233          */
 234         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
 235
 236         /* External processing makes no sense here */
 237         tp->t_lflag &= ~EXTPROC;
 238
 239         /*
 240          * Wait here if we don't have carrier.
 241          */
 242 #if 0
 243         while ((tp->t_state & TS_CARR_ON) == 0) {
 244                 if (flag & FNONBLOCK)
 245                         break;
 246                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0);
 247                 if (error)
 248                         return (error);
 249         }
 250 #endif
 251
 252         /*
 253          * Give the line disciplin a chance to set this end up.
 254          */
 255         error = (*linesw[tp->t_line].l_open)(dev, tp);
 256
 257         /*
 258          * Wake up the other side.
 259          * Theoretically not needed.
 260          */
 261         ourpart->modemsignals |= TIOCM_DTR;
 262         nmdm_crossover(pti, ourpart, otherpart);
 263         if (error == 0)
 264                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
 265         return (error);
 266 }
 267
 268 static  int
 269 nmdmclose(dev_t dev, int flag, int mode, struct thread *td)
 270 {
 271         struct tty *tp, *tp2;
 272         int err;
 273         struct softpart *ourpart, *otherpart;
 274
 275         /*
 276          * let the other end know that the game is up
 277          */
 278         tp = dev->si_tty;
 279         GETPARTS(tp, ourpart, otherpart);
 280         tp2 = &otherpart->nm_tty;
 281         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
 282
 283         /*
 284          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
 285          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 286          * l_modem()s that ignore carrier drop make no sense for nmdms but
 287          * may be in use because other parts of the line discipline make
 288          * sense for nmdms.  Recover by doing everything that a normal
 289          * ttymodem() would have done except for sending a SIGHUP.
 290          */
 291         if (tp2->t_state & TS_ISOPEN) {
 292                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 293                 tp2->t_state |= TS_ZOMBIE;
 294                 ttyflush(tp2, FREAD | FWRITE);
 295         }
 296
 297         err = (*linesw[tp->t_line].l_close)(tp, flag);
 298         ourpart->modemsignals &= ~TIOCM_DTR;
 299         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
 300         nmdmstop(tp, FREAD|FWRITE);
 301         (void) ttyclose(tp);
 302         return (err);
 303 }
 304
 305 static  int
 306 nmdmread(dev_t dev, struct uio *uio, int flag)
 307 {
 308         int error = 0;
 309         struct tty *tp, *tp2;
 310         struct softpart *ourpart, *otherpart;
 311
 312         tp = dev->si_tty;
 313         GETPARTS(tp, ourpart, otherpart);
 314         tp2 = &otherpart->nm_tty;
 315
 316 #if 0
 317         if (tp2->t_state & TS_ISOPEN) {
 318                 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
 319                 wakeup_other(tp, FWRITE);
 320         } else {
 321                 if (flag & IO_NDELAY) {
 322                         return (EWOULDBLOCK);
 323                 }
 324                 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0);
 325                 }
 326         }
 327 #else
 328         if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
 329                 wakeup_other(tp, FWRITE);
 330 #endif
 331         return (error);
 332 }
 333
 334 /*
 335  * Write to pseudo-tty.
 336  * Wakeups of controlling tty will happen
 337  * indirectly, when tty driver calls nmdmstart.
 338  */
 339 static  int
 340 nmdmwrite(dev_t dev, struct uio *uio, int flag)
 341 {
 342         u_char *cp = 0;
 343         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                                                 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(struct tty *tp)
 435 {
 436         struct nm_softc *pti = tp->t_dev->si_drv1;
 437
 438         if (tp->t_state & TS_TTSTOP)
 439                 return;
 440         pti->pt_flags &= ~PF_STOPPED;
 441         wakeup_other(tp, FREAD);
 442 }
 443
 444 /* Wakes up the OTHER tty;*/
 445 static void
 446 wakeup_other(struct tty *tp, int flag)
 447 {
 448         struct softpart *ourpart, *otherpart;
 449
 450         GETPARTS(tp, ourpart, otherpart);
 451         if (flag & FREAD) {
 452                 selwakeup(&otherpart->nm_tty.t_rsel);
 453                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
 454         }
 455         if (flag & FWRITE) {
 456                 selwakeup(&otherpart->nm_tty.t_wsel);
 457                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
 458         }
 459 }
 460
 461 static  void
 462 nmdmstop(struct tty *tp, int flush)
 463 {
 464         struct nm_softc *pti = tp->t_dev->si_drv1;
 465         int flag;
 466
 467         /* note: FLUSHREAD and FLUSHWRITE already ok */
 468         if (flush == 0) {
 469                 flush = TIOCPKT_STOP;
 470                 pti->pt_flags |= PF_STOPPED;
 471         } else
 472                 pti->pt_flags &= ~PF_STOPPED;
 473         /* change of perspective */
 474         flag = 0;
 475         if (flush & FREAD)
 476                 flag |= FWRITE;
 477         if (flush & FWRITE)
 478                 flag |= FREAD;
 479         wakeup_other(tp, flag);
 480 }
 481
 482 /*ARGSUSED*/
 483 static  int
 484 nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 485 {
 486         struct tty *tp = dev->si_tty;
 487         struct nm_softc *pti = dev->si_drv1;
 488         int error;
 489         struct tty *tp2;
 490         struct softpart *ourpart, *otherpart;
 491
 492         crit_enter();
 493         GETPARTS(tp, ourpart, otherpart);
 494         tp2 = &otherpart->nm_tty;
 495
 496         error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
 497         if (error == ENOIOCTL)
 498                  error = ttioctl(tp, cmd, data, flag);
 499         if (error == ENOIOCTL) {
 500                 switch (cmd) {
 501                 case TIOCSBRK:
 502                         otherpart->gotbreak = 1;
 503                         break;
 504                 case TIOCCBRK:
 505                         break;
 506                 case TIOCSDTR:
 507                         ourpart->modemsignals |= TIOCM_DTR;
 508                         break;
 509                 case TIOCCDTR:
 510                         ourpart->modemsignals &= TIOCM_DTR;
 511                         break;
 512                 case TIOCMSET:
 513                         ourpart->modemsignals = *(int *)data;
 514                         otherpart->modemsignals = *(int *)data;
 515                         break;
 516                 case TIOCMBIS:
 517                         ourpart->modemsignals |= *(int *)data;
 518                         break;
 519                 case TIOCMBIC:
 520                         ourpart->modemsignals &= ~(*(int *)data);
 521                         otherpart->modemsignals &= ~(*(int *)data);
 522                         break;
 523                 case TIOCMGET:
 524                         *(int *)data = ourpart->modemsignals;
 525                         break;
 526                 case TIOCMSDTRWAIT:
 527                         break;
 528                 case TIOCMGDTRWAIT:
 529                         *(int *)data = 0;
 530                         break;
 531                 case TIOCTIMESTAMP:
 532                 case TIOCDCDTIMESTAMP:
 533                 default:
 534                         crit_exit();
 535                         error = ENOTTY;
 536                         return (error);
 537                 }
 538                 error = 0;
 539                 nmdm_crossover(pti, ourpart, otherpart);
 540         }
 541         crit_exit();
 542         return (error);
 543 }
 544
 545 static void
 546 nmdm_crossover(struct nm_softc *pti,
 547                 struct softpart *ourpart,
 548                 struct softpart *otherpart)
 549 {
 550         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
 551         if (ourpart->modemsignals & TIOCM_RTS)
 552                 otherpart->modemsignals |= TIOCM_CTS;
 553         if (ourpart->modemsignals & TIOCM_DTR)
 554                 otherpart->modemsignals |= TIOCM_CAR;
 555 }
 556
 557
 558
 559 static void nmdm_drvinit (void *unused);
 560
 561 static void
 562 nmdm_drvinit(void *unused)
 563 {
 564         /* XXX: Gross hack for DEVFS */
 565         nmdminit(0);
 566 }
 567
 568 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)