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 */ 35 36 /* 37 * Pseudo-nulmodem Driver 38 */ 39 #include "opt_compat.h" 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 43 #include <sys/ioctl_compat.h> 44 #endif 45 #include <sys/proc.h> 46 #include <sys/tty.h> 47 #include <sys/conf.h> 48 #include <sys/fcntl.h> 49 #include <sys/poll.h> 50 #include <sys/kernel.h> 51 #include <sys/vnode.h> 52 #include <sys/signalvar.h> 53 #include <sys/malloc.h> 54 55 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures"); 56 57 static void nmdmstart __P((struct tty *tp)); 58 static void nmdmstop __P((struct tty *tp, int rw)); 59 static void wakeup_other __P((struct tty *tp, int flag)); 60 static void nmdminit __P((int n)); 61 62 static d_open_t nmdmopen; 63 static d_close_t nmdmclose; 64 static d_read_t nmdmread; 65 static d_write_t nmdmwrite; 66 static d_ioctl_t nmdmioctl; 67 68 #define CDEV_MAJOR 18 69 static struct cdevsw nmdm_cdevsw = { 70 /* open */ nmdmopen, 71 /* close */ nmdmclose, 72 /* read */ nmdmread, 73 /* write */ nmdmwrite, 74 /* ioctl */ nmdmioctl, 75 /* poll */ ttypoll, 76 /* mmap */ nommap, 77 /* strategy */ nostrategy, 78 /* name */ "pts", 79 /* maj */ CDEV_MAJOR, 80 /* dump */ nodump, 81 /* psize */ nopsize, 82 /* flags */ D_TTY, 83 /* bmaj */ -1 84 }; 85 86 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 87 88 struct softpart { 89 struct tty nm_tty; 90 dev_t dev; 91 int modemsignals; /* bits defined in sys/ttycom.h */ 92 int gotbreak; 93 }; 94 95 struct nm_softc { 96 int pt_flags; 97 struct softpart part1, part2; 98 struct prison *pt_prison; 99 }; 100 101 #define PF_STOPPED 0x10 /* user told stopped */ 102 103 static void 104 nmdm_crossover(struct nm_softc *pti, 105 struct softpart *ourpart, 106 struct softpart *otherpart); 107 108 #define GETPARTS(tp, ourpart, otherpart) \ 109 do { \ 110 struct nm_softc *pti = tp->t_dev->si_drv1; \ 111 if (tp == &pti->part1.nm_tty) { \ 112 ourpart = &pti->part1; \ 113 otherpart = &pti->part2; \ 114 } else { \ 115 ourpart = &pti->part2; \ 116 otherpart = &pti->part1; \ 117 } \ 118 } while (0) 119 120 /* 121 * This function creates and initializes a pair of ttys. 122 */ 123 static void 124 nmdminit(n) 125 int n; 126 { 127 dev_t dev1, dev2; 128 struct nm_softc *pt; 129 130 /* For now we only map the lower 8 bits of the minor */ 131 if (n & ~0xff) 132 return; 133 134 pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK); 135 bzero(pt, sizeof(*pt)); 136 pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n, 137 0, 0, 0666, "nmdm%dA", n); 138 pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1, 139 0, 0, 0666, "nmdm%dB", n); 140 141 dev1->si_drv1 = dev2->si_drv1 = pt; 142 dev1->si_tty = &pt->part1.nm_tty; 143 dev2->si_tty = &pt->part2.nm_tty; 144 ttyregister(&pt->part1.nm_tty); 145 ttyregister(&pt->part2.nm_tty); 146 pt->part1.nm_tty.t_oproc = nmdmstart; 147 pt->part2.nm_tty.t_oproc = nmdmstart; 148 pt->part1.nm_tty.t_stop = nmdmstop; 149 pt->part2.nm_tty.t_dev = dev1; 150 pt->part1.nm_tty.t_dev = dev2; 151 pt->part2.nm_tty.t_stop = nmdmstop; 152 } 153 154 /*ARGSUSED*/ 155 static int 156 nmdmopen(dev, flag, devtype, p) 157 dev_t dev; 158 int flag, devtype; 159 struct proc *p; 160 { 161 register struct tty *tp, *tp2; 162 int error; 163 int minr; 164 dev_t nextdev; 165 struct nm_softc *pti; 166 int is_b; 167 int pair; 168 struct softpart *ourpart, *otherpart; 169 170 /* 171 * XXX: Gross hack for DEVFS: 172 * If we openned this device, ensure we have the 173 * next one too, so people can open it. 174 */ 175 minr = lminor(dev); 176 pair = minr >> 1; 177 is_b = minr & 1; 178 179 if (pair < 127) { 180 nextdev = makedev(major(dev), (pair+pair) + 1); 181 if (!nextdev->si_drv1) { 182 nmdminit(pair + 1); 183 } 184 } 185 if (!dev->si_drv1) 186 nmdminit(pair); 187 188 if (!dev->si_drv1) 189 return(ENXIO); 190 191 pti = dev->si_drv1; 192 if (is_b) 193 tp = &pti->part2.nm_tty; 194 else 195 tp = &pti->part1.nm_tty; 196 GETPARTS(tp, ourpart, otherpart); 197 tp2 = &otherpart->nm_tty; 198 ourpart->modemsignals |= TIOCM_LE; 199 200 if ((tp->t_state & TS_ISOPEN) == 0) { 201 ttychars(tp); /* Set up default chars */ 202 tp->t_iflag = TTYDEF_IFLAG; 203 tp->t_oflag = TTYDEF_OFLAG; 204 tp->t_lflag = TTYDEF_LFLAG; 205 tp->t_cflag = TTYDEF_CFLAG; 206 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED; 207 } else if (tp->t_state & TS_XCLUDE && suser(p)) { 208 return (EBUSY); 209 } else if (pti->pt_prison != p->p_prison) { 210 return (EBUSY); 211 } 212 213 /* 214 * If the other side is open we have carrier 215 */ 216 if (tp2->t_state & TS_ISOPEN) { 217 (void)(*linesw[tp->t_line].l_modem)(tp, 1); 218 } 219 220 /* 221 * And the other side gets carrier as we are now open. 222 */ 223 (void)(*linesw[tp2->t_line].l_modem)(tp2, 1); 224 225 /* External processing makes no sense here */ 226 tp->t_lflag &= ~EXTPROC; 227 228 /* 229 * Wait here if we don't have carrier. 230 */ 231 #if 0 232 while ((tp->t_state & TS_CARR_ON) == 0) { 233 if (flag & FNONBLOCK) 234 break; 235 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH, 236 "nmdopn", 0); 237 if (error) 238 return (error); 239 } 240 #endif 241 242 /* 243 * Give the line disciplin a chance to set this end up. 244 */ 245 error = (*linesw[tp->t_line].l_open)(dev, tp); 246 247 /* 248 * Wake up the other side. 249 * Theoretically not needed. 250 */ 251 ourpart->modemsignals |= TIOCM_DTR; 252 nmdm_crossover(pti, ourpart, otherpart); 253 if (error == 0) 254 wakeup_other(tp, FREAD|FWRITE); /* XXX */ 255 return (error); 256 } 257 258 static int 259 nmdmclose(dev, flag, mode, p) 260 dev_t dev; 261 int flag, mode; 262 struct proc *p; 263 { 264 register struct tty *tp, *tp2; 265 int err; 266 struct softpart *ourpart, *otherpart; 267 268 /* 269 * let the other end know that the game is up 270 */ 271 tp = dev->si_tty; 272 GETPARTS(tp, ourpart, otherpart); 273 tp2 = &otherpart->nm_tty; 274 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0); 275 276 /* 277 * XXX MDMBUF makes no sense for nmdms but would inhibit the above 278 * l_modem(). CLOCAL makes sense but isn't supported. Special 279 * l_modem()s that ignore carrier drop make no sense for nmdms but 280 * may be in use because other parts of the line discipline make 281 * sense for nmdms. Recover by doing everything that a normal 282 * ttymodem() would have done except for sending a SIGHUP. 283 */ 284 if (tp2->t_state & TS_ISOPEN) { 285 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED); 286 tp2->t_state |= TS_ZOMBIE; 287 ttyflush(tp2, FREAD | FWRITE); 288 } 289 290 err = (*linesw[tp->t_line].l_close)(tp, flag); 291 ourpart->modemsignals &= ~TIOCM_DTR; 292 nmdm_crossover(dev->si_drv1, ourpart, otherpart); 293 nmdmstop(tp, FREAD|FWRITE); 294 (void) ttyclose(tp); 295 return (err); 296 } 297 298 static int 299 nmdmread(dev, uio, flag) 300 dev_t dev; 301 struct uio *uio; 302 int flag; 303 { 304 int error = 0; 305 struct tty *tp, *tp2; 306 struct softpart *ourpart, *otherpart; 307 308 tp = dev->si_tty; 309 GETPARTS(tp, ourpart, otherpart); 310 tp2 = &otherpart->nm_tty; 311 312 #if 0 313 if (tp2->t_state & TS_ISOPEN) { 314 error = (*linesw[tp->t_line].l_read)(tp, uio, flag); 315 wakeup_other(tp, FWRITE); 316 } else { 317 if (flag & IO_NDELAY) { 318 return (EWOULDBLOCK); 319 } 320 error = tsleep(TSA_PTC_READ(tp), 321 TTIPRI | PCATCH, "nmdout", 0); 322 } 323 } 324 #else 325 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0) 326 wakeup_other(tp, FWRITE); 327 #endif 328 return (error); 329 } 330 331 /* 332 * Write to pseudo-tty. 333 * Wakeups of controlling tty will happen 334 * indirectly, when tty driver calls nmdmstart. 335 */ 336 static int 337 nmdmwrite(dev, uio, flag) 338 dev_t dev; 339 struct uio *uio; 340 int flag; 341 { 342 register u_char *cp = 0; 343 register 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 TTOPRI | 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(tp) 435 struct tty *tp; 436 { 437 register struct nm_softc *pti = tp->t_dev->si_drv1; 438 439 if (tp->t_state & TS_TTSTOP) 440 return; 441 pti->pt_flags &= ~PF_STOPPED; 442 wakeup_other(tp, FREAD); 443 } 444 445 /* Wakes up the OTHER tty;*/ 446 static void 447 wakeup_other(tp, flag) 448 struct tty *tp; 449 int flag; 450 { 451 struct softpart *ourpart, *otherpart; 452 453 GETPARTS(tp, ourpart, otherpart); 454 if (flag & FREAD) { 455 selwakeup(&otherpart->nm_tty.t_rsel); 456 wakeup(TSA_PTC_READ((&otherpart->nm_tty))); 457 } 458 if (flag & FWRITE) { 459 selwakeup(&otherpart->nm_tty.t_wsel); 460 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty))); 461 } 462 } 463 464 static void 465 nmdmstop(tp, flush) 466 register struct tty *tp; 467 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 /*ARGSUSED*/ 488 static int 489 nmdmioctl(dev, cmd, data, flag, p) 490 dev_t dev; 491 u_long cmd; 492 caddr_t data; 493 int flag; 494 struct proc *p; 495 { 496 register struct tty *tp = dev->si_tty; 497 struct nm_softc *pti = dev->si_drv1; 498 int error, s; 499 register struct tty *tp2; 500 struct softpart *ourpart, *otherpart; 501 502 s = spltty(); 503 GETPARTS(tp, ourpart, otherpart); 504 tp2 = &otherpart->nm_tty; 505 506 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p); 507 if (error == ENOIOCTL) 508 error = ttioctl(tp, cmd, data, flag); 509 if (error == ENOIOCTL) { 510 switch (cmd) { 511 case TIOCSBRK: 512 otherpart->gotbreak = 1; 513 break; 514 case TIOCCBRK: 515 break; 516 case TIOCSDTR: 517 ourpart->modemsignals |= TIOCM_DTR; 518 break; 519 case TIOCCDTR: 520 ourpart->modemsignals &= TIOCM_DTR; 521 break; 522 case TIOCMSET: 523 ourpart->modemsignals = *(int *)data; 524 otherpart->modemsignals = *(int *)data; 525 break; 526 case TIOCMBIS: 527 ourpart->modemsignals |= *(int *)data; 528 break; 529 case TIOCMBIC: 530 ourpart->modemsignals &= ~(*(int *)data); 531 otherpart->modemsignals &= ~(*(int *)data); 532 break; 533 case TIOCMGET: 534 *(int *)data = ourpart->modemsignals; 535 break; 536 case TIOCMSDTRWAIT: 537 break; 538 case TIOCMGDTRWAIT: 539 *(int *)data = 0; 540 break; 541 case TIOCTIMESTAMP: 542 case TIOCDCDTIMESTAMP: 543 default: 544 splx(s); 545 error = ENOTTY; 546 return (error); 547 } 548 error = 0; 549 nmdm_crossover(pti, ourpart, otherpart); 550 } 551 splx(s); 552 return (error); 553 } 554 555 static void 556 nmdm_crossover(struct nm_softc *pti, 557 struct softpart *ourpart, 558 struct softpart *otherpart) 559 { 560 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR); 561 if (ourpart->modemsignals & TIOCM_RTS) 562 otherpart->modemsignals |= TIOCM_CTS; 563 if (ourpart->modemsignals & TIOCM_DTR) 564 otherpart->modemsignals |= TIOCM_CAR; 565 } 566 567 568 569 static void nmdm_drvinit __P((void *unused)); 570 571 static void 572 nmdm_drvinit(unused) 573 void *unused; 574 { 575 cdevsw_add(&nmdm_cdevsw); 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