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 1.10 2004/05/19 22:52:43 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 (struct tty *tp); 59 static void nmdmstop (struct tty *tp, int rw); 60 static void wakeup_other (struct tty *tp, int flag); 61 static void nmdminit (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 /* name */ "pts", 72 /* maj */ CDEV_MAJOR, 73 /* flags */ D_TTY, 74 /* port */ NULL, 75 /* clone */ NULL, 76 77 /* open */ nmdmopen, 78 /* close */ nmdmclose, 79 /* read */ nmdmread, 80 /* write */ nmdmwrite, 81 /* ioctl */ nmdmioctl, 82 /* poll */ ttypoll, 83 /* mmap */ nommap, 84 /* strategy */ nostrategy, 85 /* dump */ nodump, 86 /* psize */ nopsize 87 }; 88 89 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 90 91 struct softpart { 92 struct tty nm_tty; 93 dev_t dev; 94 int modemsignals; /* bits defined in sys/ttycom.h */ 95 int gotbreak; 96 }; 97 98 struct nm_softc { 99 int pt_flags; 100 struct softpart part1, part2; 101 struct prison *pt_prison; 102 }; 103 104 #define PF_STOPPED 0x10 /* user told stopped */ 105 106 static void 107 nmdm_crossover(struct nm_softc *pti, 108 struct softpart *ourpart, 109 struct softpart *otherpart); 110 111 #define GETPARTS(tp, ourpart, otherpart) \ 112 do { \ 113 struct nm_softc *pti = tp->t_dev->si_drv1; \ 114 if (tp == &pti->part1.nm_tty) { \ 115 ourpart = &pti->part1; \ 116 otherpart = &pti->part2; \ 117 } else { \ 118 ourpart = &pti->part2; \ 119 otherpart = &pti->part1; \ 120 } \ 121 } while (0) 122 123 /* 124 * This function creates and initializes a pair of ttys. 125 */ 126 static void 127 nmdminit(n) 128 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, uio, flag) 307 dev_t dev; 308 struct uio *uio; 309 int flag; 310 { 311 int error = 0; 312 struct tty *tp, *tp2; 313 struct softpart *ourpart, *otherpart; 314 315 tp = dev->si_tty; 316 GETPARTS(tp, ourpart, otherpart); 317 tp2 = &otherpart->nm_tty; 318 319 #if 0 320 if (tp2->t_state & TS_ISOPEN) { 321 error = (*linesw[tp->t_line].l_read)(tp, uio, flag); 322 wakeup_other(tp, FWRITE); 323 } else { 324 if (flag & IO_NDELAY) { 325 return (EWOULDBLOCK); 326 } 327 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0); 328 } 329 } 330 #else 331 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0) 332 wakeup_other(tp, FWRITE); 333 #endif 334 return (error); 335 } 336 337 /* 338 * Write to pseudo-tty. 339 * Wakeups of controlling tty will happen 340 * indirectly, when tty driver calls nmdmstart. 341 */ 342 static int 343 nmdmwrite(dev, uio, flag) 344 dev_t dev; 345 struct uio *uio; 346 int flag; 347 { 348 u_char *cp = 0; 349 int cc = 0; 350 u_char locbuf[BUFSIZ]; 351 int cnt = 0; 352 int error = 0; 353 struct tty *tp1, *tp; 354 struct softpart *ourpart, *otherpart; 355 356 tp1 = dev->si_tty; 357 /* 358 * Get the other tty struct. 359 * basically we are writing into the INPUT side of the other device. 360 */ 361 GETPARTS(tp1, ourpart, otherpart); 362 tp = &otherpart->nm_tty; 363 364 again: 365 if ((tp->t_state & TS_ISOPEN) == 0) 366 return (EIO); 367 while (uio->uio_resid > 0 || cc > 0) { 368 /* 369 * Fill up the buffer if it's empty 370 */ 371 if (cc == 0) { 372 cc = min(uio->uio_resid, BUFSIZ); 373 cp = locbuf; 374 error = uiomove((caddr_t)cp, cc, uio); 375 if (error) 376 return (error); 377 /* check again for safety */ 378 if ((tp->t_state & TS_ISOPEN) == 0) { 379 /* adjust for data copied in but not written */ 380 uio->uio_resid += cc; 381 return (EIO); 382 } 383 } 384 while (cc > 0) { 385 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2)) 386 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) { 387 /* 388 * Come here to wait for space in outq, 389 * or space in rawq, or an empty canq. 390 */ 391 wakeup(TSA_HUP_OR_INPUT(tp)); 392 if ((tp->t_state & TS_CONNECTED) == 0) { 393 /* 394 * Data piled up because not connected. 395 * Adjust for data copied in but 396 * not written. 397 */ 398 uio->uio_resid += cc; 399 return (EIO); 400 } 401 if (flag & IO_NDELAY) { 402 /* 403 * Don't wait if asked not to. 404 * Adjust for data copied in but 405 * not written. 406 */ 407 uio->uio_resid += cc; 408 if (cnt == 0) 409 return (EWOULDBLOCK); 410 return (0); 411 } 412 error = tsleep(TSA_PTC_WRITE(tp), 413 PCATCH, "nmdout", 0); 414 if (error) { 415 /* 416 * Tsleep returned (signal?). 417 * Go find out what the user wants. 418 * adjust for data copied in but 419 * not written 420 */ 421 uio->uio_resid += cc; 422 return (error); 423 } 424 goto again; 425 } 426 (*linesw[tp->t_line].l_rint)(*cp++, tp); 427 cnt++; 428 cc--; 429 } 430 cc = 0; 431 } 432 return (0); 433 } 434 435 /* 436 * Start output on pseudo-tty. 437 * Wake up process selecting or sleeping for input from controlling tty. 438 */ 439 static void 440 nmdmstart(tp) 441 struct tty *tp; 442 { 443 struct nm_softc *pti = tp->t_dev->si_drv1; 444 445 if (tp->t_state & TS_TTSTOP) 446 return; 447 pti->pt_flags &= ~PF_STOPPED; 448 wakeup_other(tp, FREAD); 449 } 450 451 /* Wakes up the OTHER tty;*/ 452 static void 453 wakeup_other(tp, flag) 454 struct tty *tp; 455 int flag; 456 { 457 struct softpart *ourpart, *otherpart; 458 459 GETPARTS(tp, ourpart, otherpart); 460 if (flag & FREAD) { 461 selwakeup(&otherpart->nm_tty.t_rsel); 462 wakeup(TSA_PTC_READ((&otherpart->nm_tty))); 463 } 464 if (flag & FWRITE) { 465 selwakeup(&otherpart->nm_tty.t_wsel); 466 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty))); 467 } 468 } 469 470 static void 471 nmdmstop(tp, flush) 472 struct tty *tp; 473 int flush; 474 { 475 struct nm_softc *pti = tp->t_dev->si_drv1; 476 int flag; 477 478 /* note: FLUSHREAD and FLUSHWRITE already ok */ 479 if (flush == 0) { 480 flush = TIOCPKT_STOP; 481 pti->pt_flags |= PF_STOPPED; 482 } else 483 pti->pt_flags &= ~PF_STOPPED; 484 /* change of perspective */ 485 flag = 0; 486 if (flush & FREAD) 487 flag |= FWRITE; 488 if (flush & FWRITE) 489 flag |= FREAD; 490 wakeup_other(tp, flag); 491 } 492 493 /*ARGSUSED*/ 494 static int 495 nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 496 { 497 struct tty *tp = dev->si_tty; 498 struct nm_softc *pti = dev->si_drv1; 499 int error, s; 500 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, td); 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 (void *unused); 571 572 static void 573 nmdm_drvinit(unused) 574 void *unused; 575 { 576 /* XXX: Gross hack for DEVFS */ 577 nmdminit(0); 578 } 579 580 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL) 581