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 1.16 2008/01/05 14:02:37 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 dev_ops nmdm_ops = {
  72         { "pts", CDEV_MAJOR, D_TTY },
  73         .d_open =       nmdmopen,
  74         .d_close =      nmdmclose,
  75         .d_read =       nmdmread,
  76         .d_write =      nmdmwrite,
  77         .d_ioctl =      nmdmioctl,
  78         .d_poll =       ttypoll,
  79 };
  80
  81 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
  82
  83 struct softpart {
  84         struct tty nm_tty;
  85         cdev_t  dev;
  86         int     modemsignals;   /* bits defined in sys/ttycom.h */
  87         int     gotbreak;
  88 };
  89
  90 struct  nm_softc {
  91         int     pt_flags;
  92         struct softpart part1, part2;
  93         struct  prison *pt_prison;
  94 };
  95
  96 #define PF_STOPPED      0x10            /* user told stopped */
  97
  98 static void
  99 nmdm_crossover(struct nm_softc *pti,
 100                 struct softpart *ourpart,
 101                 struct softpart *otherpart);
 102
 103 #define GETPARTS(tp, ourpart, otherpart) \
 104 do {    \
 105         struct nm_softc *pti = tp->t_dev->si_drv1; \
 106         if (tp == &pti->part1.nm_tty) { \
 107                 ourpart = &pti->part1; \
 108                 otherpart = &pti->part2; \
 109         } else { \
 110                 ourpart = &pti->part2; \
 111                 otherpart = &pti->part1; \
 112         }  \
 113 } while (0)
 114
 115 /*
 116  * This function creates and initializes a pair of ttys.
 117  */
 118 static void
 119 nmdminit(int n)
 120 {
 121         cdev_t dev1, dev2;
 122         struct nm_softc *pt;
 123
 124         /*
 125          * Simplified unit number, use low 8 bits of minor number
 126          * (remember, the minor number mask is 0xffff00ff).
 127          */
 128         if (n & ~0x7f)
 129                 return;
 130
 131         pt = kmalloc(sizeof(*pt), M_NLMDM, M_WAITOK | M_ZERO);
 132         dev_ops_add(&nmdm_ops, ~1, n << 1);
 133         pt->part1.dev = dev1 = make_dev(&nmdm_ops, n << 1,
 134             0, 0, 0666, "nmdm%dA", n);
 135         pt->part2.dev = dev2 = make_dev(&nmdm_ops, (n << 1) + 1,
 136             0, 0, 0666, "nmdm%dB", n);
 137
 138         dev1->si_drv1 = dev2->si_drv1 = pt;
 139         dev1->si_tty = &pt->part1.nm_tty;
 140         dev2->si_tty = &pt->part2.nm_tty;
 141         ttyregister(&pt->part1.nm_tty);
 142         ttyregister(&pt->part2.nm_tty);
 143         pt->part1.nm_tty.t_oproc = nmdmstart;
 144         pt->part2.nm_tty.t_oproc = nmdmstart;
 145         pt->part1.nm_tty.t_stop = nmdmstop;
 146         pt->part2.nm_tty.t_dev = dev1;
 147         pt->part1.nm_tty.t_dev = dev2;
 148         pt->part2.nm_tty.t_stop = nmdmstop;
 149 }
 150
 151 /*ARGSUSED*/
 152 static  int
 153 nmdmopen(struct dev_open_args *ap)
 154 {
 155         cdev_t dev = ap->a_head.a_dev;
 156         struct tty *tp, *tp2;
 157         int error;
 158         int minr;
 159 #if 0
 160         cdev_t nextdev;
 161 #endif
 162         struct nm_softc *pti;
 163         int is_b;
 164         int     pair;
 165         struct  softpart *ourpart, *otherpart;
 166
 167         minr = lminor(dev);
 168         pair = minr >> 1;
 169         is_b = minr & 1;
 170
 171 #if 0
 172         /*
 173          * XXX: Gross hack for DEVFS:
 174          * If we openned this device, ensure we have the
 175          * next one too, so people can open it.
 176          */
 177         if (pair < 127) {
 178                 nextdev = makedev(major(dev), (pair+pair) + 1);
 179                 if (!nextdev->si_drv1) {
 180                         nmdminit(pair + 1);
 181                 }
 182         }
 183 #endif
 184         if (!dev->si_drv1)
 185                 nmdminit(pair);
 186
 187         if (!dev->si_drv1)
 188                 return(ENXIO);
 189
 190         pti = dev->si_drv1;
 191         if (is_b)
 192                 tp = &pti->part2.nm_tty;
 193         else
 194                 tp = &pti->part1.nm_tty;
 195         GETPARTS(tp, ourpart, otherpart);
 196         tp2 = &otherpart->nm_tty;
 197         ourpart->modemsignals |= TIOCM_LE;
 198
 199         if ((tp->t_state & TS_ISOPEN) == 0) {
 200                 ttychars(tp);           /* Set up default chars */
 201                 tp->t_iflag = TTYDEF_IFLAG;
 202                 tp->t_oflag = TTYDEF_OFLAG;
 203                 tp->t_lflag = TTYDEF_LFLAG;
 204                 tp->t_cflag = TTYDEF_CFLAG;
 205                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
 206         } else if (tp->t_state & TS_XCLUDE && suser_cred(ap->a_cred, 0)) {
 207                 return (EBUSY);
 208         } else if (pti->pt_prison != ap->a_cred->cr_prison) {
 209                 return (EBUSY);
 210         }
 211
 212         /*
 213          * If the other side is open we have carrier
 214          */
 215         if (tp2->t_state & TS_ISOPEN) {
 216                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
 217         }
 218
 219         /*
 220          * And the other side gets carrier as we are now open.
 221          */
 222         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
 223
 224         /* External processing makes no sense here */
 225         tp->t_lflag &= ~EXTPROC;
 226
 227         /*
 228          * Wait here if we don't have carrier.
 229          */
 230 #if 0
 231         while ((tp->t_state & TS_CARR_ON) == 0) {
 232                 if (flag & FNONBLOCK)
 233                         break;
 234                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0);
 235                 if (error)
 236                         return (error);
 237         }
 238 #endif
 239
 240         /*
 241          * Give the line disciplin a chance to set this end up.
 242          */
 243         error = (*linesw[tp->t_line].l_open)(dev, tp);
 244
 245         /*
 246          * Wake up the other side.
 247          * Theoretically not needed.
 248          */
 249         ourpart->modemsignals |= TIOCM_DTR;
 250         nmdm_crossover(pti, ourpart, otherpart);
 251         if (error == 0)
 252                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
 253         return (error);
 254 }
 255
 256 static int
 257 nmdmclose(struct dev_close_args *ap)
 258 {
 259         cdev_t dev = ap->a_head.a_dev;
 260         struct tty *tp, *tp2;
 261         int err;
 262         struct softpart *ourpart, *otherpart;
 263
 264         /*
 265          * let the other end know that the game is up
 266          */
 267         tp = dev->si_tty;
 268         GETPARTS(tp, ourpart, otherpart);
 269         tp2 = &otherpart->nm_tty;
 270         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
 271
 272         /*
 273          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
 274          * l_modem().  CLOCAL makes sense but isn't supported.   Special
 275          * l_modem()s that ignore carrier drop make no sense for nmdms but
 276          * may be in use because other parts of the line discipline make
 277          * sense for nmdms.  Recover by doing everything that a normal
 278          * ttymodem() would have done except for sending a SIGHUP.
 279          */
 280         if (tp2->t_state & TS_ISOPEN) {
 281                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
 282                 tp2->t_state |= TS_ZOMBIE;
 283                 ttyflush(tp2, FREAD | FWRITE);
 284         }
 285
 286         err = (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
 287         ourpart->modemsignals &= ~TIOCM_DTR;
 288         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
 289         nmdmstop(tp, FREAD|FWRITE);
 290         (void) ttyclose(tp);
 291         return (err);
 292 }
 293
 294 static int
 295 nmdmread(struct dev_read_args *ap)
 296 {
 297         cdev_t dev = ap->a_head.a_dev;
 298         int error = 0;
 299         struct tty *tp, *tp2;
 300         struct softpart *ourpart, *otherpart;
 301
 302         tp = dev->si_tty;
 303         GETPARTS(tp, ourpart, otherpart);
 304         tp2 = &otherpart->nm_tty;
 305
 306 #if 0
 307         if (tp2->t_state & TS_ISOPEN) {
 308                 error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, flag);
 309                 wakeup_other(tp, FWRITE);
 310         } else {
 311                 if (flag & IO_NDELAY) {
 312                         return (EWOULDBLOCK);
 313                 }
 314                 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0);
 315                 }
 316         }
 317 #else
 318         if ((error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag)) == 0)
 319                 wakeup_other(tp, FWRITE);
 320 #endif
 321         return (error);
 322 }
 323
 324 /*
 325  * Write to pseudo-tty.
 326  * Wakeups of controlling tty will happen
 327  * indirectly, when tty driver calls nmdmstart.
 328  */
 329 static  int
 330 nmdmwrite(struct dev_write_args *ap)
 331 {
 332         cdev_t dev = ap->a_head.a_dev;
 333         struct uio *uio = ap->a_uio;
 334         u_char *cp = 0;
 335         int cc = 0;
 336         u_char locbuf[BUFSIZ];
 337         int cnt = 0;
 338         int error = 0;
 339         struct tty *tp1, *tp;
 340         struct softpart *ourpart, *otherpart;
 341
 342         tp1 = dev->si_tty;
 343         /*
 344          * Get the other tty struct.
 345          * basically we are writing into the INPUT side of the other device.
 346          */
 347         GETPARTS(tp1, ourpart, otherpart);
 348         tp = &otherpart->nm_tty;
 349
 350 again:
 351         if ((tp->t_state & TS_ISOPEN) == 0)
 352                 return (EIO);
 353         while (uio->uio_resid > 0 || cc > 0) {
 354                 /*
 355                  * Fill up the buffer if it's empty
 356                  */
 357                 if (cc == 0) {
 358                         cc = min(uio->uio_resid, BUFSIZ);
 359                         cp = locbuf;
 360                         error = uiomove((caddr_t)cp, cc, uio);
 361                         if (error)
 362                                 return (error);
 363                         /* check again for safety */
 364                         if ((tp->t_state & TS_ISOPEN) == 0) {
 365                                 /* adjust for data copied in but not written */
 366                                 uio->uio_resid += cc;
 367                                 return (EIO);
 368                         }
 369                 }
 370                 while (cc > 0) {
 371                         if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
 372                         && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
 373                                 /*
 374                                  * Come here to wait for space in outq,
 375                                  * or space in rawq, or an empty canq.
 376                                  */
 377                                 wakeup(TSA_HUP_OR_INPUT(tp));
 378                                 if ((tp->t_state & TS_CONNECTED) == 0) {
 379                                         /*
 380                                          * Data piled up because not connected.
 381                                          * Adjust for data copied in but
 382                                          * not written.
 383                                          */
 384                                         uio->uio_resid += cc;
 385                                         return (EIO);
 386                                 }
 387                                 if (ap->a_ioflag & IO_NDELAY) {
 388                                         /*
 389                                          * Don't wait if asked not to.
 390                                          * Adjust for data copied in but
 391                                          * not written.
 392                                          */
 393                                         uio->uio_resid += cc;
 394                                         if (cnt == 0)
 395                                                 return (EWOULDBLOCK);
 396                                         return (0);
 397                                 }
 398                                 error = tsleep(TSA_PTC_WRITE(tp),
 399                                                 PCATCH, "nmdout", 0);
 400                                 if (error) {
 401                                         /*
 402                                          * Tsleep returned (signal?).
 403                                          * Go find out what the user wants.
 404                                          * adjust for data copied in but
 405                                          * not written
 406                                          */
 407                                         uio->uio_resid += cc;
 408                                         return (error);
 409                                 }
 410                                 goto again;
 411                         }
 412                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
 413                         cnt++;
 414                         cc--;
 415                 }
 416                 cc = 0;
 417         }
 418         return (0);
 419 }
 420
 421 /*
 422  * Start output on pseudo-tty.
 423  * Wake up process selecting or sleeping for input from controlling tty.
 424  */
 425 static void
 426 nmdmstart(struct tty *tp)
 427 {
 428         struct nm_softc *pti = tp->t_dev->si_drv1;
 429
 430         if (tp->t_state & TS_TTSTOP)
 431                 return;
 432         pti->pt_flags &= ~PF_STOPPED;
 433         wakeup_other(tp, FREAD);
 434 }
 435
 436 /* Wakes up the OTHER tty;*/
 437 static void
 438 wakeup_other(struct tty *tp, int flag)
 439 {
 440         struct softpart *ourpart, *otherpart;
 441
 442         GETPARTS(tp, ourpart, otherpart);
 443         if (flag & FREAD) {
 444                 selwakeup(&otherpart->nm_tty.t_rsel);
 445                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
 446         }
 447         if (flag & FWRITE) {
 448                 selwakeup(&otherpart->nm_tty.t_wsel);
 449                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
 450         }
 451 }
 452
 453 static  void
 454 nmdmstop(struct tty *tp, int flush)
 455 {
 456         struct nm_softc *pti = tp->t_dev->si_drv1;
 457         int flag;
 458
 459         /* note: FLUSHREAD and FLUSHWRITE already ok */
 460         if (flush == 0) {
 461                 flush = TIOCPKT_STOP;
 462                 pti->pt_flags |= PF_STOPPED;
 463         } else
 464                 pti->pt_flags &= ~PF_STOPPED;
 465         /* change of perspective */
 466         flag = 0;
 467         if (flush & FREAD)
 468                 flag |= FWRITE;
 469         if (flush & FWRITE)
 470                 flag |= FREAD;
 471         wakeup_other(tp, flag);
 472 }
 473
 474 /*ARGSUSED*/
 475 static  int
 476 nmdmioctl(struct dev_ioctl_args *ap)
 477 {
 478         cdev_t dev = ap->a_head.a_dev;
 479         struct tty *tp = dev->si_tty;
 480         struct nm_softc *pti = dev->si_drv1;
 481         int error;
 482         struct tty *tp2;
 483         struct softpart *ourpart, *otherpart;
 484
 485         crit_enter();
 486         GETPARTS(tp, ourpart, otherpart);
 487         tp2 = &otherpart->nm_tty;
 488
 489         error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
 490                                               ap->a_fflag, ap->a_cred);
 491         if (error == ENOIOCTL)
 492                  error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
 493         if (error == ENOIOCTL) {
 494                 switch (ap->a_cmd) {
 495                 case TIOCSBRK:
 496                         otherpart->gotbreak = 1;
 497                         break;
 498                 case TIOCCBRK:
 499                         break;
 500                 case TIOCSDTR:
 501                         ourpart->modemsignals |= TIOCM_DTR;
 502                         break;
 503                 case TIOCCDTR:
 504                         ourpart->modemsignals &= TIOCM_DTR;
 505                         break;
 506                 case TIOCMSET:
 507                         ourpart->modemsignals = *(int *)ap->a_data;
 508                         otherpart->modemsignals = *(int *)ap->a_data;
 509                         break;
 510                 case TIOCMBIS:
 511                         ourpart->modemsignals |= *(int *)ap->a_data;
 512                         break;
 513                 case TIOCMBIC:
 514                         ourpart->modemsignals &= ~(*(int *)ap->a_data);
 515                         otherpart->modemsignals &= ~(*(int *)ap->a_data);
 516                         break;
 517                 case TIOCMGET:
 518                         *(int *)ap->a_data = ourpart->modemsignals;
 519                         break;
 520                 case TIOCMSDTRWAIT:
 521                         break;
 522                 case TIOCMGDTRWAIT:
 523                         *(int *)ap->a_data = 0;
 524                         break;
 525                 case TIOCTIMESTAMP:
 526                 case TIOCDCDTIMESTAMP:
 527                 default:
 528                         crit_exit();
 529                         error = ENOTTY;
 530                         return (error);
 531                 }
 532                 error = 0;
 533                 nmdm_crossover(pti, ourpart, otherpart);
 534         }
 535         crit_exit();
 536         return (error);
 537 }
 538
 539 static void
 540 nmdm_crossover(struct nm_softc *pti,
 541                 struct softpart *ourpart,
 542                 struct softpart *otherpart)
 543 {
 544         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
 545         if (ourpart->modemsignals & TIOCM_RTS)
 546                 otherpart->modemsignals |= TIOCM_CTS;
 547         if (ourpart->modemsignals & TIOCM_DTR)
 548                 otherpart->modemsignals |= TIOCM_CAR;
 549 }
 550
 551
 552
 553 static void nmdm_drvinit (void *unused);
 554
 555 static void
 556 nmdm_drvinit(void *unused)
 557 {
 558         /* XXX: Gross hack for DEVFS */
 559         nmdminit(0);
 560 }
 561
 562 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)