1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $FreeBSD: src/sys/dev/nmdm/nmdm.c,v 1.5.2.1 2001/08/11 00:54:14 mp Exp $ 36 */ 37 38 /* 39 * MPSAFE NOTE: This file acquires the tty_token mainly for linesw access and 40 * tp (struct tty) access. 41 */ 42 43 /* 44 * Pseudo-nulmodem Driver 45 */ 46 #include "opt_compat.h" 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 50 #include <sys/ioctl_compat.h> 51 #endif 52 #include <sys/proc.h> 53 #include <sys/priv.h> 54 #include <sys/thread2.h> 55 #include <sys/tty.h> 56 #include <sys/conf.h> 57 #include <sys/fcntl.h> 58 #include <sys/kernel.h> 59 #include <sys/vnode.h> 60 #include <sys/signalvar.h> 61 #include <sys/malloc.h> 62 63 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures"); 64 65 static void nmdmstart (struct tty *tp); 66 static void nmdmstop (struct tty *tp, int rw); 67 static void wakeup_other (struct tty *tp, int flag); 68 static void nmdminit (int n); 69 70 static d_open_t nmdmopen; 71 static d_close_t nmdmclose; 72 static d_read_t nmdmread; 73 static d_write_t nmdmwrite; 74 static d_ioctl_t nmdmioctl; 75 76 #define CDEV_MAJOR 18 77 static struct dev_ops nmdm_ops = { 78 { "pts", 0, D_TTY }, 79 .d_open = nmdmopen, 80 .d_close = nmdmclose, 81 .d_read = nmdmread, 82 .d_write = nmdmwrite, 83 .d_ioctl = nmdmioctl, 84 .d_kqfilter = ttykqfilter, 85 .d_revoke = ttyrevoke 86 }; 87 88 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 89 90 struct softpart { 91 struct tty nm_tty; 92 cdev_t dev; 93 int modemsignals; /* bits defined in sys/ttycom.h */ 94 int gotbreak; 95 }; 96 97 struct nm_softc { 98 int pt_flags; 99 struct softpart part1, part2; 100 struct prison *pt_prison; 101 }; 102 103 #define PF_STOPPED 0x10 /* user told stopped */ 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 * NOTE: Must be called with tty_token held 126 */ 127 static void 128 nmdminit(int n) 129 { 130 cdev_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 ASSERT_LWKT_TOKEN_HELD(&tty_token); 141 142 pt = kmalloc(sizeof(*pt), M_NLMDM, M_WAITOK | M_ZERO); 143 pt->part1.dev = dev1 = make_dev(&nmdm_ops, n << 1, 144 0, 0, 0666, "nmdm%dA", n); 145 pt->part2.dev = dev2 = make_dev(&nmdm_ops, (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(struct dev_open_args *ap) 164 { 165 cdev_t dev = ap->a_head.a_dev; 166 struct tty *tp, *tp2; 167 int error; 168 int minr; 169 #if 0 170 cdev_t nextdev; 171 #endif 172 struct nm_softc *pti; 173 int is_b; 174 int pair; 175 struct softpart *ourpart, *otherpart; 176 177 minr = lminor(dev); 178 pair = minr >> 1; 179 is_b = minr & 1; 180 181 #if 0 182 /* 183 * XXX: Gross hack for DEVFS: 184 * If we openned this device, ensure we have the 185 * next one too, so people can open it. 186 */ 187 if (pair < 127) { 188 nextdev = makedev(major(dev), (pair+pair) + 1); 189 if (!nextdev->si_drv1) { 190 nmdminit(pair + 1); 191 } 192 } 193 #endif 194 if (!dev->si_drv1) 195 nmdminit(pair); 196 197 if (!dev->si_drv1) 198 return(ENXIO); 199 200 lwkt_gettoken(&tty_token); 201 pti = dev->si_drv1; 202 if (is_b) 203 tp = &pti->part2.nm_tty; 204 else 205 tp = &pti->part1.nm_tty; 206 GETPARTS(tp, ourpart, otherpart); 207 tp2 = &otherpart->nm_tty; 208 ourpart->modemsignals |= TIOCM_LE; 209 210 if ((tp->t_state & TS_ISOPEN) == 0) { 211 ttychars(tp); /* Set up default chars */ 212 tp->t_iflag = TTYDEF_IFLAG; 213 tp->t_oflag = TTYDEF_OFLAG; 214 tp->t_lflag = TTYDEF_LFLAG; 215 tp->t_cflag = TTYDEF_CFLAG; 216 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED; 217 } else if (tp->t_state & TS_XCLUDE && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) { 218 lwkt_reltoken(&tty_token); 219 return (EBUSY); 220 } else if (pti->pt_prison != ap->a_cred->cr_prison) { 221 lwkt_reltoken(&tty_token); 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 lwkt_reltoken(&tty_token); 250 return (error); 251 } 252 } 253 #endif 254 255 /* 256 * Give the line disciplin a chance to set this end up. 257 */ 258 error = (*linesw[tp->t_line].l_open)(dev, tp); 259 260 /* 261 * Wake up the other side. 262 * Theoretically not needed. 263 */ 264 ourpart->modemsignals |= TIOCM_DTR; 265 nmdm_crossover(pti, ourpart, otherpart); 266 if (error == 0) 267 wakeup_other(tp, FREAD|FWRITE); /* XXX */ 268 lwkt_reltoken(&tty_token); 269 return (error); 270 } 271 272 static int 273 nmdmclose(struct dev_close_args *ap) 274 { 275 cdev_t dev = ap->a_head.a_dev; 276 struct tty *tp, *tp2; 277 int err; 278 struct softpart *ourpart, *otherpart; 279 280 lwkt_gettoken(&tty_token); 281 /* 282 * let the other end know that the game is up 283 */ 284 tp = dev->si_tty; 285 GETPARTS(tp, ourpart, otherpart); 286 tp2 = &otherpart->nm_tty; 287 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0); 288 289 /* 290 * XXX MDMBUF makes no sense for nmdms but would inhibit the above 291 * l_modem(). CLOCAL makes sense but isn't supported. Special 292 * l_modem()s that ignore carrier drop make no sense for nmdms but 293 * may be in use because other parts of the line discipline make 294 * sense for nmdms. Recover by doing everything that a normal 295 * ttymodem() would have done except for sending a SIGHUP. 296 */ 297 if (tp2->t_state & TS_ISOPEN) { 298 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED); 299 tp2->t_state |= TS_ZOMBIE; 300 ttyflush(tp2, FREAD | FWRITE); 301 } 302 303 err = (*linesw[tp->t_line].l_close)(tp, ap->a_fflag); 304 ourpart->modemsignals &= ~TIOCM_DTR; 305 nmdm_crossover(dev->si_drv1, ourpart, otherpart); 306 nmdmstop(tp, FREAD|FWRITE); 307 (void) ttyclose(tp); 308 lwkt_reltoken(&tty_token); 309 return (err); 310 } 311 312 static int 313 nmdmread(struct dev_read_args *ap) 314 { 315 cdev_t dev = ap->a_head.a_dev; 316 int error = 0; 317 struct tty *tp, *tp2; 318 struct softpart *ourpart, *otherpart; 319 320 lwkt_gettoken(&tty_token); 321 tp = dev->si_tty; 322 GETPARTS(tp, ourpart, otherpart); 323 tp2 = &otherpart->nm_tty; 324 325 #if 0 326 if (tp2->t_state & TS_ISOPEN) { 327 error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, flag); 328 wakeup_other(tp, FWRITE); 329 } else { 330 if (flag & IO_NDELAY) { 331 lwkt_reltoken(&tty_token); 332 return (EWOULDBLOCK); 333 } 334 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0); 335 } 336 } 337 #else 338 if ((error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag)) == 0) 339 wakeup_other(tp, FWRITE); 340 #endif 341 lwkt_reltoken(&tty_token); 342 return (error); 343 } 344 345 /* 346 * Write to pseudo-tty. 347 * Wakeups of controlling tty will happen 348 * indirectly, when tty driver calls nmdmstart. 349 */ 350 static int 351 nmdmwrite(struct dev_write_args *ap) 352 { 353 cdev_t dev = ap->a_head.a_dev; 354 struct uio *uio = ap->a_uio; 355 u_char *cp = NULL; 356 size_t cc = 0; 357 u_char locbuf[BUFSIZ]; 358 int cnt = 0; 359 int error = 0; 360 struct tty *tp1, *tp; 361 struct softpart *ourpart, *otherpart; 362 363 lwkt_gettoken(&tty_token); 364 tp1 = dev->si_tty; 365 /* 366 * Get the other tty struct. 367 * basically we are writing into the INPUT side of the other device. 368 */ 369 GETPARTS(tp1, ourpart, otherpart); 370 tp = &otherpart->nm_tty; 371 372 again: 373 if ((tp->t_state & TS_ISOPEN) == 0) { 374 lwkt_reltoken(&tty_token); 375 return (EIO); 376 } 377 while (uio->uio_resid > 0 || cc > 0) { 378 /* 379 * Fill up the buffer if it's empty 380 */ 381 if (cc == 0) { 382 cc = szmin(uio->uio_resid, BUFSIZ); 383 cp = locbuf; 384 error = uiomove((caddr_t)cp, cc, uio); 385 if (error) { 386 lwkt_reltoken(&tty_token); 387 return (error); 388 } 389 /* check again for safety */ 390 if ((tp->t_state & TS_ISOPEN) == 0) { 391 /* adjust for data copied in but not written */ 392 uio->uio_resid += cc; 393 lwkt_reltoken(&tty_token); 394 return (EIO); 395 } 396 } 397 while (cc > 0) { 398 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2)) 399 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) { 400 /* 401 * Come here to wait for space in outq, 402 * or space in rawq, or an empty canq. 403 */ 404 wakeup(TSA_HUP_OR_INPUT(tp)); 405 if ((tp->t_state & TS_CONNECTED) == 0) { 406 /* 407 * Data piled up because not connected. 408 * Adjust for data copied in but 409 * not written. 410 */ 411 uio->uio_resid += cc; 412 lwkt_reltoken(&tty_token); 413 return (EIO); 414 } 415 if (ap->a_ioflag & IO_NDELAY) { 416 /* 417 * Don't wait if asked not to. 418 * Adjust for data copied in but 419 * not written. 420 */ 421 uio->uio_resid += cc; 422 if (cnt == 0) { 423 lwkt_reltoken(&tty_token); 424 return (EWOULDBLOCK); 425 } 426 lwkt_reltoken(&tty_token); 427 return (0); 428 } 429 error = tsleep(TSA_PTC_WRITE(tp), 430 PCATCH, "nmdout", 0); 431 if (error) { 432 /* 433 * Tsleep returned (signal?). 434 * Go find out what the user wants. 435 * adjust for data copied in but 436 * not written 437 */ 438 uio->uio_resid += cc; 439 lwkt_reltoken(&tty_token); 440 return (error); 441 } 442 goto again; 443 } 444 (*linesw[tp->t_line].l_rint)(*cp++, tp); 445 cnt++; 446 cc--; 447 } 448 cc = 0; 449 } 450 lwkt_reltoken(&tty_token); 451 return (0); 452 } 453 454 /* 455 * Start output on pseudo-tty. 456 * Wake up process selecting or sleeping for input from controlling tty. 457 */ 458 static void 459 nmdmstart(struct tty *tp) 460 { 461 struct nm_softc *pti = tp->t_dev->si_drv1; 462 463 lwkt_gettoken(&tty_token); 464 if (tp->t_state & TS_TTSTOP) { 465 lwkt_reltoken(&tty_token); 466 return; 467 } 468 pti->pt_flags &= ~PF_STOPPED; 469 wakeup_other(tp, FREAD); 470 lwkt_reltoken(&tty_token); 471 } 472 473 /* Wakes up the OTHER tty;*/ 474 static void 475 wakeup_other(struct tty *tp, int flag) 476 { 477 struct softpart *ourpart, *otherpart; 478 479 lwkt_gettoken(&tty_token); 480 GETPARTS(tp, ourpart, otherpart); 481 if (flag & FREAD) { 482 wakeup(TSA_PTC_READ((&otherpart->nm_tty))); 483 KNOTE(&otherpart->nm_tty.t_rkq.ki_note, 0); 484 } 485 if (flag & FWRITE) { 486 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty))); 487 KNOTE(&otherpart->nm_tty.t_wkq.ki_note, 0); 488 } 489 lwkt_reltoken(&tty_token); 490 } 491 492 static void 493 nmdmstop(struct tty *tp, int flush) 494 { 495 struct nm_softc *pti = tp->t_dev->si_drv1; 496 int flag; 497 498 lwkt_gettoken(&tty_token); 499 /* note: FLUSHREAD and FLUSHWRITE already ok */ 500 if (flush == 0) { 501 flush = TIOCPKT_STOP; 502 pti->pt_flags |= PF_STOPPED; 503 } else 504 pti->pt_flags &= ~PF_STOPPED; 505 /* change of perspective */ 506 flag = 0; 507 if (flush & FREAD) 508 flag |= FWRITE; 509 if (flush & FWRITE) 510 flag |= FREAD; 511 wakeup_other(tp, flag); 512 lwkt_reltoken(&tty_token); 513 } 514 515 /*ARGSUSED*/ 516 static int 517 nmdmioctl(struct dev_ioctl_args *ap) 518 { 519 cdev_t dev = ap->a_head.a_dev; 520 struct tty *tp = dev->si_tty; 521 struct nm_softc *pti = dev->si_drv1; 522 int error; 523 struct tty *tp2; 524 struct softpart *ourpart, *otherpart; 525 526 crit_enter(); 527 lwkt_gettoken(&tty_token); 528 GETPARTS(tp, ourpart, otherpart); 529 tp2 = &otherpart->nm_tty; 530 531 error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data, 532 ap->a_fflag, ap->a_cred); 533 if (error == ENOIOCTL) 534 error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag); 535 if (error == ENOIOCTL) { 536 switch (ap->a_cmd) { 537 case TIOCSBRK: 538 otherpart->gotbreak = 1; 539 break; 540 case TIOCCBRK: 541 break; 542 case TIOCSDTR: 543 ourpart->modemsignals |= TIOCM_DTR; 544 break; 545 case TIOCCDTR: 546 ourpart->modemsignals &= TIOCM_DTR; 547 break; 548 case TIOCMSET: 549 ourpart->modemsignals = *(int *)ap->a_data; 550 otherpart->modemsignals = *(int *)ap->a_data; 551 break; 552 case TIOCMBIS: 553 ourpart->modemsignals |= *(int *)ap->a_data; 554 break; 555 case TIOCMBIC: 556 ourpart->modemsignals &= ~(*(int *)ap->a_data); 557 otherpart->modemsignals &= ~(*(int *)ap->a_data); 558 break; 559 case TIOCMGET: 560 *(int *)ap->a_data = ourpart->modemsignals; 561 break; 562 case TIOCMSDTRWAIT: 563 break; 564 case TIOCMGDTRWAIT: 565 *(int *)ap->a_data = 0; 566 break; 567 case TIOCTIMESTAMP: 568 case TIOCDCDTIMESTAMP: 569 default: 570 lwkt_reltoken(&tty_token); 571 crit_exit(); 572 error = ENOTTY; 573 return (error); 574 } 575 error = 0; 576 nmdm_crossover(pti, ourpart, otherpart); 577 } 578 lwkt_reltoken(&tty_token); 579 crit_exit(); 580 return (error); 581 } 582 583 static void 584 nmdm_crossover(struct nm_softc *pti, 585 struct softpart *ourpart, 586 struct softpart *otherpart) 587 { 588 lwkt_gettoken(&tty_token); 589 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR); 590 if (ourpart->modemsignals & TIOCM_RTS) 591 otherpart->modemsignals |= TIOCM_CTS; 592 if (ourpart->modemsignals & TIOCM_DTR) 593 otherpart->modemsignals |= TIOCM_CAR; 594 lwkt_reltoken(&tty_token); 595 } 596 597 598 599 static void nmdm_drvinit (void *unused); 600 601 static void 602 nmdm_drvinit(void *unused) 603 { 604 /* XXX: Gross hack for DEVFS */ 605 lwkt_gettoken(&tty_token); 606 nmdminit(0); 607 lwkt_reltoken(&tty_token); 608 } 609 610 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL) 611