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 * $FreeBSD$ 34 */ 35 36 /* 37 * Pseudo-nulmodem driver 38 * Mighty handy for use with serial console in Vmware 39 */ 40 41 #include "opt_compat.h" 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 45 #include <sys/ioctl_compat.h> 46 #endif 47 #include <sys/proc.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); 63 static int nmdmshutdown(void); 64 65 static d_open_t nmdmopen; 66 static d_close_t nmdmclose; 67 static d_read_t nmdmread; 68 static d_write_t nmdmwrite; 69 static d_ioctl_t nmdmioctl; 70 71 #define CDEV_MAJOR 18 72 static struct cdevsw nmdm_cdevsw = { 73 /* open */ nmdmopen, 74 /* close */ nmdmclose, 75 /* read */ nmdmread, 76 /* write */ nmdmwrite, 77 /* ioctl */ nmdmioctl, 78 /* poll */ ttypoll, 79 /* mmap */ nommap, 80 /* strategy */ nostrategy, 81 /* name */ "pts", 82 /* maj */ CDEV_MAJOR, 83 /* dump */ nodump, 84 /* psize */ nopsize, 85 /* flags */ D_TTY, 86 }; 87 88 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 89 #define NMDM_MAX_NUM 128 /* Artificially limit # devices. */ 90 #define PF_STOPPED 0x10 /* user told stopped */ 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 static void 106 nmdm_crossover(struct nm_softc *pti, 107 struct softpart *ourpart, 108 struct softpart *otherpart); 109 110 #define GETPARTS(tp, ourpart, otherpart) \ 111 do { \ 112 struct nm_softc *pti = tp->t_dev->si_drv1; \ 113 if (tp == &pti->part1.nm_tty) { \ 114 ourpart = &pti->part1; \ 115 otherpart = &pti->part2; \ 116 } else { \ 117 ourpart = &pti->part2; \ 118 otherpart = &pti->part1; \ 119 } \ 120 } while (0) 121 122 /* 123 * This function creates and initializes a pair of ttys. 124 */ 125 static void 126 nmdminit(n) 127 int n; 128 { 129 dev_t dev1, dev2; 130 struct nm_softc *pt; 131 132 /* For now we only map the lower 8 bits of the minor */ 133 if (n & ~0xff) 134 return; 135 136 pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK); 137 bzero(pt, sizeof(*pt)); 138 pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n, 139 0, 0, 0666, "nmdm%dA", n); 140 pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1, 141 0, 0, 0666, "nmdm%dB", n); 142 143 dev1->si_drv1 = dev2->si_drv1 = pt; 144 dev1->si_tty = &pt->part1.nm_tty; 145 dev2->si_tty = &pt->part2.nm_tty; 146 ttyregister(&pt->part1.nm_tty); 147 ttyregister(&pt->part2.nm_tty); 148 pt->part1.nm_tty.t_oproc = nmdmstart; 149 pt->part2.nm_tty.t_oproc = nmdmstart; 150 pt->part1.nm_tty.t_stop = nmdmstop; 151 pt->part2.nm_tty.t_dev = dev1; 152 pt->part1.nm_tty.t_dev = dev2; 153 pt->part2.nm_tty.t_stop = nmdmstop; 154 } 155 156 /* 157 * Device opened from userland 158 */ 159 static int 160 nmdmopen(dev_t dev, int flag, int devtype, struct thread *td) 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 = dev2unit(dev); 177 pair = minr >> 1; 178 is_b = minr & 1; 179 180 if (pair < (NMDM_MAX_NUM - 1)) { 181 nextdev = makedev(major(dev), minr + 2); 182 if (!nextdev->si_drv1) { 183 nmdminit(pair + 1); 184 } 185 } else { /* Limit ourselves to 128 of them for now */ 186 if (pair > (NMDM_MAX_NUM - 1)) 187 return (ENXIO); 188 } 189 if (!dev->si_drv1) 190 nmdminit(pair); 191 192 if (!dev->si_drv1) 193 return(ENXIO); 194 195 pti = dev->si_drv1; 196 if (is_b) 197 tp = &pti->part2.nm_tty; 198 else 199 tp = &pti->part1.nm_tty; 200 GETPARTS(tp, ourpart, otherpart); 201 202 tp2 = &otherpart->nm_tty; 203 ourpart->modemsignals |= TIOCM_LE; 204 205 if ((tp->t_state & TS_ISOPEN) == 0) { 206 ttychars(tp); /* Set up default chars */ 207 tp->t_iflag = TTYDEF_IFLAG; 208 tp->t_oflag = TTYDEF_OFLAG; 209 tp->t_lflag = TTYDEF_LFLAG; 210 tp->t_cflag = TTYDEF_CFLAG; 211 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED; 212 } else if (tp->t_state & TS_XCLUDE && suser_td(td)) { 213 return (EBUSY); 214 } else if (pti->pt_prison != td->td_ucred->cr_prison) { 215 return (EBUSY); 216 } 217 218 /* 219 * If the other side is open we have carrier 220 */ 221 if (tp2->t_state & TS_ISOPEN) { 222 (void)(*linesw[tp->t_line].l_modem)(tp, 1); 223 } 224 225 /* 226 * And the other side gets carrier as we are now open. 227 */ 228 (void)(*linesw[tp2->t_line].l_modem)(tp2, 1); 229 230 /* External processing makes no sense here */ 231 tp->t_lflag &= ~EXTPROC; 232 233 /* 234 * Wait here if we don't have carrier. 235 */ 236 #if 0 237 while ((tp->t_state & TS_CARR_ON) == 0) { 238 if (flag & FNONBLOCK) 239 break; 240 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH, 241 "nmdopn", 0); 242 if (error) 243 return (error); 244 } 245 #endif 246 247 /* 248 * Give the line disciplin a chance to set this end up. 249 */ 250 error = (*linesw[tp->t_line].l_open)(dev, tp); 251 252 /* 253 * Wake up the other side. 254 * Theoretically not needed. 255 */ 256 ourpart->modemsignals |= TIOCM_DTR; 257 nmdm_crossover(pti, ourpart, otherpart); 258 if (error == 0) 259 wakeup_other(tp, FREAD|FWRITE); /* XXX */ 260 return (error); 261 } 262 263 /* 264 * Device closed again 265 */ 266 static int 267 nmdmclose(dev_t dev, int flag, int mode, struct thread *td) 268 { 269 register struct tty *tp, *tp2; 270 int err; 271 struct softpart *ourpart, *otherpart; 272 273 /* 274 * let the other end know that the game is up 275 */ 276 tp = dev->si_tty; 277 GETPARTS(tp, ourpart, otherpart); 278 tp2 = &otherpart->nm_tty; 279 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0); 280 281 /* 282 * XXX MDMBUF makes no sense for nmdms but would inhibit the above 283 * l_modem(). CLOCAL makes sense but isn't supported. Special 284 * l_modem()s that ignore carrier drop make no sense for nmdms but 285 * may be in use because other parts of the line discipline make 286 * sense for nmdms. Recover by doing everything that a normal 287 * ttymodem() would have done except for sending a SIGHUP. 288 */ 289 if (tp2->t_state & TS_ISOPEN) { 290 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED); 291 tp2->t_state |= TS_ZOMBIE; 292 ttyflush(tp2, FREAD | FWRITE); 293 } 294 295 err = (*linesw[tp->t_line].l_close)(tp, flag); 296 ourpart->modemsignals &= ~TIOCM_DTR; 297 nmdm_crossover(dev->si_drv1, ourpart, otherpart); 298 nmdmstop(tp, FREAD|FWRITE); 299 (void) ttyclose(tp); 300 return (err); 301 } 302 303 /* 304 * handle read(2) request from userland 305 */ 306 static int 307 nmdmread(dev_t dev, struct uio *uio, int flag) 308 { 309 int error = 0; 310 struct tty *tp, *tp2; 311 struct softpart *ourpart, *otherpart; 312 313 tp = dev->si_tty; 314 GETPARTS(tp, ourpart, otherpart); 315 tp2 = &otherpart->nm_tty; 316 317 #if 0 318 if (tp2->t_state & TS_ISOPEN) { 319 error = (*linesw[tp->t_line].l_read)(tp, uio, flag); 320 wakeup_other(tp, FWRITE); 321 } else { 322 if (flag & IO_NDELAY) { 323 return (EWOULDBLOCK); 324 } 325 error = tsleep(TSA_PTC_READ(tp), 326 TTIPRI | PCATCH, "nmdout", 0); 327 } 328 } 329 #else 330 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0) 331 wakeup_other(tp, FWRITE); 332 #endif 333 return (error); 334 } 335 336 /* 337 * Write to pseudo-tty. 338 * Wakeups of controlling tty will happen 339 * indirectly, when tty driver calls nmdmstart. 340 */ 341 static int 342 nmdmwrite(dev_t dev, struct uio *uio, int flag) 343 { 344 register u_char *cp = 0; 345 register int cc = 0; 346 u_char locbuf[BUFSIZ]; 347 int cnt = 0; 348 int error = 0; 349 struct tty *tp1, *tp; 350 struct softpart *ourpart, *otherpart; 351 352 tp1 = dev->si_tty; 353 /* 354 * Get the other tty struct. 355 * basically we are writing into the INPUT side of the other device. 356 */ 357 GETPARTS(tp1, ourpart, otherpart); 358 tp = &otherpart->nm_tty; 359 360 again: 361 if ((tp->t_state & TS_ISOPEN) == 0) 362 return (EIO); 363 while (uio->uio_resid > 0 || cc > 0) { 364 /* 365 * Fill up the buffer if it's empty 366 */ 367 if (cc == 0) { 368 cc = min(uio->uio_resid, BUFSIZ); 369 cp = locbuf; 370 error = uiomove((caddr_t)cp, cc, uio); 371 if (error) 372 return (error); 373 /* check again for safety */ 374 if ((tp->t_state & TS_ISOPEN) == 0) { 375 /* adjust for data copied in but not written */ 376 uio->uio_resid += cc; 377 return (EIO); 378 } 379 } 380 while (cc > 0) { 381 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2)) 382 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) { 383 /* 384 * Come here to wait for space in outq, 385 * or space in rawq, or an empty canq. 386 */ 387 wakeup(TSA_HUP_OR_INPUT(tp)); 388 if ((tp->t_state & TS_CONNECTED) == 0) { 389 /* 390 * Data piled up because not connected. 391 * Adjust for data copied in but 392 * not written. 393 */ 394 uio->uio_resid += cc; 395 return (EIO); 396 } 397 if (flag & IO_NDELAY) { 398 /* 399 * Don't wait if asked not to. 400 * Adjust for data copied in but 401 * not written. 402 */ 403 uio->uio_resid += cc; 404 if (cnt == 0) 405 return (EWOULDBLOCK); 406 return (0); 407 } 408 error = tsleep(TSA_PTC_WRITE(tp), 409 TTOPRI | PCATCH, "nmdout", 0); 410 if (error) { 411 /* 412 * Tsleep returned (signal?). 413 * Go find out what the user wants. 414 * adjust for data copied in but 415 * not written 416 */ 417 uio->uio_resid += cc; 418 return (error); 419 } 420 goto again; 421 } 422 (*linesw[tp->t_line].l_rint)(*cp++, tp); 423 cnt++; 424 cc--; 425 } 426 cc = 0; 427 } 428 return (0); 429 } 430 431 /* 432 * Start output on pseudo-tty. 433 * Wake up process selecting or sleeping for input from controlling tty. 434 */ 435 static void 436 nmdmstart(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(struct tty *tp, int flag) 449 { 450 struct softpart *ourpart, *otherpart; 451 452 GETPARTS(tp, ourpart, otherpart); 453 if (flag & FREAD) { 454 selwakeup(&otherpart->nm_tty.t_rsel); 455 wakeup(TSA_PTC_READ((&otherpart->nm_tty))); 456 } 457 if (flag & FWRITE) { 458 selwakeup(&otherpart->nm_tty.t_wsel); 459 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty))); 460 } 461 } 462 463 /* 464 * stopped output on tty, called when device is closed 465 */ 466 static void 467 nmdmstop(register struct tty *tp, 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 /* 488 * handle ioctl(2) request from userland 489 */ 490 static int 491 nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 492 { 493 register struct tty *tp = dev->si_tty; 494 struct nm_softc *pti = dev->si_drv1; 495 int error, s; 496 register struct tty *tp2; 497 struct softpart *ourpart, *otherpart; 498 499 s = spltty(); 500 GETPARTS(tp, ourpart, otherpart); 501 tp2 = &otherpart->nm_tty; 502 503 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td); 504 if (error == ENOIOCTL) 505 error = ttioctl(tp, cmd, data, flag); 506 if (error == ENOIOCTL) { 507 switch (cmd) { 508 case TIOCSBRK: 509 otherpart->gotbreak = 1; 510 break; 511 case TIOCCBRK: 512 break; 513 case TIOCSDTR: 514 ourpart->modemsignals |= TIOCM_DTR; 515 break; 516 case TIOCCDTR: 517 ourpart->modemsignals &= TIOCM_DTR; 518 break; 519 case TIOCMSET: 520 ourpart->modemsignals = *(int *)data; 521 otherpart->modemsignals = *(int *)data; 522 break; 523 case TIOCMBIS: 524 ourpart->modemsignals |= *(int *)data; 525 break; 526 case TIOCMBIC: 527 ourpart->modemsignals &= ~(*(int *)data); 528 otherpart->modemsignals &= ~(*(int *)data); 529 break; 530 case TIOCMGET: 531 *(int *)data = ourpart->modemsignals; 532 break; 533 case TIOCMSDTRWAIT: 534 break; 535 case TIOCMGDTRWAIT: 536 *(int *)data = 0; 537 break; 538 case TIOCTIMESTAMP: 539 /* FALLTHROUGH */ 540 case TIOCDCDTIMESTAMP: 541 default: 542 splx(s); 543 error = ENOTTY; 544 return (error); 545 } 546 error = 0; 547 nmdm_crossover(pti, ourpart, otherpart); 548 } 549 splx(s); 550 return (error); 551 } 552 553 static void 554 nmdm_crossover(struct nm_softc *pti, struct softpart *ourpart, 555 struct softpart *otherpart) 556 { 557 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR); 558 if (ourpart->modemsignals & TIOCM_RTS) 559 otherpart->modemsignals |= TIOCM_CTS; 560 if (ourpart->modemsignals & TIOCM_DTR) 561 otherpart->modemsignals |= TIOCM_CAR; 562 } 563 564 /* 565 * Module handling 566 */ 567 static int 568 nmdm_modevent(module_t mod, int type, void *data) 569 { 570 int error = 0; 571 572 switch(type) { 573 case MOD_LOAD: /* start with 4 of them */ 574 nmdminit(0); 575 nmdminit(1); 576 nmdminit(2); 577 nmdminit(3); 578 break; 579 580 case MOD_SHUTDOWN: 581 /* FALLTHROUGH */ 582 case MOD_UNLOAD: 583 nmdmshutdown(); 584 break; 585 default: 586 error = EOPNOTSUPP; 587 } 588 return (error); 589 } 590 591 /* 592 * Handle teardown of device 593 */ 594 static int 595 nmdmshutdown(void) 596 { 597 int i; 598 dev_t nextdev1; 599 dev_t nextdev2; 600 void * ptr1; 601 602 for(i = 0;( i < NMDM_MAX_NUM) ;i++) { 603 nextdev1 = makedev(CDEV_MAJOR, (i+i) ); 604 nextdev2 = makedev(CDEV_MAJOR, (i+i) + 1); 605 ptr1 = nextdev1->si_drv1; 606 if (ptr1) { 607 revoke_and_destroy_dev(nextdev1); 608 revoke_and_destroy_dev(nextdev2); 609 free(ptr1, M_NLMDM); 610 } else { 611 freedev(nextdev1); 612 freedev(nextdev2); 613 } 614 } 615 return(0); 616 } 617 618 DEV_MODULE(nmdm, nmdm_modevent, NULL); 619