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 1.11 2005/06/16 16:31:34 joerg 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(n) 129 int n; 130 { 131 dev_t dev1, dev2; 132 struct nm_softc *pt; 133 134 /* 135 * Simplified unit number, use low 8 bits of minor number 136 * (remember, the minor number mask is 0xffff00ff). 137 */ 138 if (n & ~0x7f) 139 return; 140 141 pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK); 142 bzero(pt, sizeof(*pt)); 143 cdevsw_add(&nmdm_cdevsw, ~1, n << 1); 144 pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n << 1, 145 0, 0, 0666, "nmdm%dA", n); 146 pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, (n << 1) + 1, 147 0, 0, 0666, "nmdm%dB", n); 148 149 dev1->si_drv1 = dev2->si_drv1 = pt; 150 dev1->si_tty = &pt->part1.nm_tty; 151 dev2->si_tty = &pt->part2.nm_tty; 152 ttyregister(&pt->part1.nm_tty); 153 ttyregister(&pt->part2.nm_tty); 154 pt->part1.nm_tty.t_oproc = nmdmstart; 155 pt->part2.nm_tty.t_oproc = nmdmstart; 156 pt->part1.nm_tty.t_stop = nmdmstop; 157 pt->part2.nm_tty.t_dev = dev1; 158 pt->part1.nm_tty.t_dev = dev2; 159 pt->part2.nm_tty.t_stop = nmdmstop; 160 } 161 162 /*ARGSUSED*/ 163 static int 164 nmdmopen(dev_t dev, int flag, int devtype, struct thread *td) 165 { 166 struct proc *p = td->td_proc; 167 struct tty *tp, *tp2; 168 int error; 169 int minr; 170 #if 0 171 dev_t nextdev; 172 #endif 173 struct nm_softc *pti; 174 int is_b; 175 int pair; 176 struct softpart *ourpart, *otherpart; 177 178 KKASSERT(p != NULL); 179 180 minr = lminor(dev); 181 pair = minr >> 1; 182 is_b = minr & 1; 183 184 #if 0 185 /* 186 * XXX: Gross hack for DEVFS: 187 * If we openned this device, ensure we have the 188 * next one too, so people can open it. 189 */ 190 if (pair < 127) { 191 nextdev = makedev(major(dev), (pair+pair) + 1); 192 if (!nextdev->si_drv1) { 193 nmdminit(pair + 1); 194 } 195 } 196 #endif 197 if (!dev->si_drv1) 198 nmdminit(pair); 199 200 if (!dev->si_drv1) 201 return(ENXIO); 202 203 pti = dev->si_drv1; 204 if (is_b) 205 tp = &pti->part2.nm_tty; 206 else 207 tp = &pti->part1.nm_tty; 208 GETPARTS(tp, ourpart, otherpart); 209 tp2 = &otherpart->nm_tty; 210 ourpart->modemsignals |= TIOCM_LE; 211 212 if ((tp->t_state & TS_ISOPEN) == 0) { 213 ttychars(tp); /* Set up default chars */ 214 tp->t_iflag = TTYDEF_IFLAG; 215 tp->t_oflag = TTYDEF_OFLAG; 216 tp->t_lflag = TTYDEF_LFLAG; 217 tp->t_cflag = TTYDEF_CFLAG; 218 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED; 219 } else if (tp->t_state & TS_XCLUDE && suser(td)) { 220 return (EBUSY); 221 } else if (pti->pt_prison != p->p_ucred->cr_prison) { 222 return (EBUSY); 223 } 224 225 /* 226 * If the other side is open we have carrier 227 */ 228 if (tp2->t_state & TS_ISOPEN) { 229 (void)(*linesw[tp->t_line].l_modem)(tp, 1); 230 } 231 232 /* 233 * And the other side gets carrier as we are now open. 234 */ 235 (void)(*linesw[tp2->t_line].l_modem)(tp2, 1); 236 237 /* External processing makes no sense here */ 238 tp->t_lflag &= ~EXTPROC; 239 240 /* 241 * Wait here if we don't have carrier. 242 */ 243 #if 0 244 while ((tp->t_state & TS_CARR_ON) == 0) { 245 if (flag & FNONBLOCK) 246 break; 247 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0); 248 if (error) 249 return (error); 250 } 251 #endif 252 253 /* 254 * Give the line disciplin a chance to set this end up. 255 */ 256 error = (*linesw[tp->t_line].l_open)(dev, tp); 257 258 /* 259 * Wake up the other side. 260 * Theoretically not needed. 261 */ 262 ourpart->modemsignals |= TIOCM_DTR; 263 nmdm_crossover(pti, ourpart, otherpart); 264 if (error == 0) 265 wakeup_other(tp, FREAD|FWRITE); /* XXX */ 266 return (error); 267 } 268 269 static int 270 nmdmclose(dev_t dev, int flag, int mode, struct thread *td) 271 { 272 struct tty *tp, *tp2; 273 int err; 274 struct softpart *ourpart, *otherpart; 275 276 /* 277 * let the other end know that the game is up 278 */ 279 tp = dev->si_tty; 280 GETPARTS(tp, ourpart, otherpart); 281 tp2 = &otherpart->nm_tty; 282 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0); 283 284 /* 285 * XXX MDMBUF makes no sense for nmdms but would inhibit the above 286 * l_modem(). CLOCAL makes sense but isn't supported. Special 287 * l_modem()s that ignore carrier drop make no sense for nmdms but 288 * may be in use because other parts of the line discipline make 289 * sense for nmdms. Recover by doing everything that a normal 290 * ttymodem() would have done except for sending a SIGHUP. 291 */ 292 if (tp2->t_state & TS_ISOPEN) { 293 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED); 294 tp2->t_state |= TS_ZOMBIE; 295 ttyflush(tp2, FREAD | FWRITE); 296 } 297 298 err = (*linesw[tp->t_line].l_close)(tp, flag); 299 ourpart->modemsignals &= ~TIOCM_DTR; 300 nmdm_crossover(dev->si_drv1, ourpart, otherpart); 301 nmdmstop(tp, FREAD|FWRITE); 302 (void) ttyclose(tp); 303 return (err); 304 } 305 306 static int 307 nmdmread(dev, uio, flag) 308 dev_t dev; 309 struct uio *uio; 310 int flag; 311 { 312 int error = 0; 313 struct tty *tp, *tp2; 314 struct softpart *ourpart, *otherpart; 315 316 tp = dev->si_tty; 317 GETPARTS(tp, ourpart, otherpart); 318 tp2 = &otherpart->nm_tty; 319 320 #if 0 321 if (tp2->t_state & TS_ISOPEN) { 322 error = (*linesw[tp->t_line].l_read)(tp, uio, flag); 323 wakeup_other(tp, FWRITE); 324 } else { 325 if (flag & IO_NDELAY) { 326 return (EWOULDBLOCK); 327 } 328 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0); 329 } 330 } 331 #else 332 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0) 333 wakeup_other(tp, FWRITE); 334 #endif 335 return (error); 336 } 337 338 /* 339 * Write to pseudo-tty. 340 * Wakeups of controlling tty will happen 341 * indirectly, when tty driver calls nmdmstart. 342 */ 343 static int 344 nmdmwrite(dev, uio, flag) 345 dev_t dev; 346 struct uio *uio; 347 int flag; 348 { 349 u_char *cp = 0; 350 int cc = 0; 351 u_char locbuf[BUFSIZ]; 352 int cnt = 0; 353 int error = 0; 354 struct tty *tp1, *tp; 355 struct softpart *ourpart, *otherpart; 356 357 tp1 = dev->si_tty; 358 /* 359 * Get the other tty struct. 360 * basically we are writing into the INPUT side of the other device. 361 */ 362 GETPARTS(tp1, ourpart, otherpart); 363 tp = &otherpart->nm_tty; 364 365 again: 366 if ((tp->t_state & TS_ISOPEN) == 0) 367 return (EIO); 368 while (uio->uio_resid > 0 || cc > 0) { 369 /* 370 * Fill up the buffer if it's empty 371 */ 372 if (cc == 0) { 373 cc = min(uio->uio_resid, BUFSIZ); 374 cp = locbuf; 375 error = uiomove((caddr_t)cp, cc, uio); 376 if (error) 377 return (error); 378 /* check again for safety */ 379 if ((tp->t_state & TS_ISOPEN) == 0) { 380 /* adjust for data copied in but not written */ 381 uio->uio_resid += cc; 382 return (EIO); 383 } 384 } 385 while (cc > 0) { 386 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2)) 387 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) { 388 /* 389 * Come here to wait for space in outq, 390 * or space in rawq, or an empty canq. 391 */ 392 wakeup(TSA_HUP_OR_INPUT(tp)); 393 if ((tp->t_state & TS_CONNECTED) == 0) { 394 /* 395 * Data piled up because not connected. 396 * Adjust for data copied in but 397 * not written. 398 */ 399 uio->uio_resid += cc; 400 return (EIO); 401 } 402 if (flag & IO_NDELAY) { 403 /* 404 * Don't wait if asked not to. 405 * Adjust for data copied in but 406 * not written. 407 */ 408 uio->uio_resid += cc; 409 if (cnt == 0) 410 return (EWOULDBLOCK); 411 return (0); 412 } 413 error = tsleep(TSA_PTC_WRITE(tp), 414 PCATCH, "nmdout", 0); 415 if (error) { 416 /* 417 * Tsleep returned (signal?). 418 * Go find out what the user wants. 419 * adjust for data copied in but 420 * not written 421 */ 422 uio->uio_resid += cc; 423 return (error); 424 } 425 goto again; 426 } 427 (*linesw[tp->t_line].l_rint)(*cp++, tp); 428 cnt++; 429 cc--; 430 } 431 cc = 0; 432 } 433 return (0); 434 } 435 436 /* 437 * Start output on pseudo-tty. 438 * Wake up process selecting or sleeping for input from controlling tty. 439 */ 440 static void 441 nmdmstart(tp) 442 struct tty *tp; 443 { 444 struct nm_softc *pti = tp->t_dev->si_drv1; 445 446 if (tp->t_state & TS_TTSTOP) 447 return; 448 pti->pt_flags &= ~PF_STOPPED; 449 wakeup_other(tp, FREAD); 450 } 451 452 /* Wakes up the OTHER tty;*/ 453 static void 454 wakeup_other(tp, flag) 455 struct tty *tp; 456 int flag; 457 { 458 struct softpart *ourpart, *otherpart; 459 460 GETPARTS(tp, ourpart, otherpart); 461 if (flag & FREAD) { 462 selwakeup(&otherpart->nm_tty.t_rsel); 463 wakeup(TSA_PTC_READ((&otherpart->nm_tty))); 464 } 465 if (flag & FWRITE) { 466 selwakeup(&otherpart->nm_tty.t_wsel); 467 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty))); 468 } 469 } 470 471 static void 472 nmdmstop(tp, flush) 473 struct tty *tp; 474 int flush; 475 { 476 struct nm_softc *pti = tp->t_dev->si_drv1; 477 int flag; 478 479 /* note: FLUSHREAD and FLUSHWRITE already ok */ 480 if (flush == 0) { 481 flush = TIOCPKT_STOP; 482 pti->pt_flags |= PF_STOPPED; 483 } else 484 pti->pt_flags &= ~PF_STOPPED; 485 /* change of perspective */ 486 flag = 0; 487 if (flush & FREAD) 488 flag |= FWRITE; 489 if (flush & FWRITE) 490 flag |= FREAD; 491 wakeup_other(tp, flag); 492 } 493 494 /*ARGSUSED*/ 495 static int 496 nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 497 { 498 struct tty *tp = dev->si_tty; 499 struct nm_softc *pti = dev->si_drv1; 500 int error; 501 struct tty *tp2; 502 struct softpart *ourpart, *otherpart; 503 504 crit_enter(); 505 GETPARTS(tp, ourpart, otherpart); 506 tp2 = &otherpart->nm_tty; 507 508 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td); 509 if (error == ENOIOCTL) 510 error = ttioctl(tp, cmd, data, flag); 511 if (error == ENOIOCTL) { 512 switch (cmd) { 513 case TIOCSBRK: 514 otherpart->gotbreak = 1; 515 break; 516 case TIOCCBRK: 517 break; 518 case TIOCSDTR: 519 ourpart->modemsignals |= TIOCM_DTR; 520 break; 521 case TIOCCDTR: 522 ourpart->modemsignals &= TIOCM_DTR; 523 break; 524 case TIOCMSET: 525 ourpart->modemsignals = *(int *)data; 526 otherpart->modemsignals = *(int *)data; 527 break; 528 case TIOCMBIS: 529 ourpart->modemsignals |= *(int *)data; 530 break; 531 case TIOCMBIC: 532 ourpart->modemsignals &= ~(*(int *)data); 533 otherpart->modemsignals &= ~(*(int *)data); 534 break; 535 case TIOCMGET: 536 *(int *)data = ourpart->modemsignals; 537 break; 538 case TIOCMSDTRWAIT: 539 break; 540 case TIOCMGDTRWAIT: 541 *(int *)data = 0; 542 break; 543 case TIOCTIMESTAMP: 544 case TIOCDCDTIMESTAMP: 545 default: 546 crit_exit(); 547 error = ENOTTY; 548 return (error); 549 } 550 error = 0; 551 nmdm_crossover(pti, ourpart, otherpart); 552 } 553 crit_exit(); 554 return (error); 555 } 556 557 static void 558 nmdm_crossover(struct nm_softc *pti, 559 struct softpart *ourpart, 560 struct softpart *otherpart) 561 { 562 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR); 563 if (ourpart->modemsignals & TIOCM_RTS) 564 otherpart->modemsignals |= TIOCM_CTS; 565 if (ourpart->modemsignals & TIOCM_DTR) 566 otherpart->modemsignals |= TIOCM_CAR; 567 } 568 569 570 571 static void nmdm_drvinit (void *unused); 572 573 static void 574 nmdm_drvinit(unused) 575 void *unused; 576 { 577 /* XXX: Gross hack for DEVFS */ 578 nmdminit(0); 579 } 580 581 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL) 582