1 /*- 2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Portions of this software were developed under sponsorship from Snow 6 * B.V., the Netherlands. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_tty.h" 34 35 /* Add compatibility bits for FreeBSD. */ 36 #define PTS_COMPAT 37 #ifdef DEV_PTY 38 /* Add /dev/ptyXX compat bits. */ 39 #define PTS_EXTERNAL 40 #endif /* DEV_PTY */ 41 /* Add bits to make Linux binaries work. */ 42 #define PTS_LINUX 43 44 #include <sys/param.h> 45 #include <sys/lock.h> 46 #include <sys/condvar.h> 47 #include <sys/conf.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/filedesc.h> 51 #include <sys/filio.h> 52 #include <sys/kernel.h> 53 #include <sys/malloc.h> 54 #include <sys/poll.h> 55 #include <sys/proc.h> 56 #include <sys/resourcevar.h> 57 #include <sys/serial.h> 58 #include <sys/stat.h> 59 #include <sys/syscall.h> 60 #include <sys/syscallsubr.h> 61 #include <sys/sysent.h> 62 #include <sys/sysproto.h> 63 #include <sys/systm.h> 64 #include <sys/tty.h> 65 #include <sys/ttycom.h> 66 67 #include <machine/stdarg.h> 68 69 static struct unrhdr *pts_pool; 70 #define MAXPTSDEVS 999 71 72 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); 73 74 /* 75 * Per-PTS structure. 76 * 77 * List of locks 78 * (t) locked by tty_lock() 79 * (c) const until freeing 80 */ 81 struct pts_softc { 82 int pts_unit; /* (c) Device unit number. */ 83 unsigned int pts_flags; /* (t) Device flags. */ 84 #define PTS_PKT 0x1 /* Packet mode. */ 85 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */ 86 char pts_pkt; /* (t) Unread packet mode data. */ 87 88 struct cv pts_inwait; /* (t) Blocking write() on master. */ 89 struct selinfo pts_inpoll; /* (t) Select queue for write(). */ 90 struct cv pts_outwait; /* (t) Blocking read() on master. */ 91 struct selinfo pts_outpoll; /* (t) Select queue for read(). */ 92 93 #ifdef PTS_EXTERNAL 94 struct cdev *pts_cdev; /* (c) Master device node. */ 95 #endif /* PTS_EXTERNAL */ 96 97 struct uidinfo *pts_uidinfo; /* (c) Resource limit. */ 98 }; 99 100 /* 101 * Controller-side file operations. 102 */ 103 104 static int 105 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 106 int flags, struct thread *td) 107 { 108 struct tty *tp = fp->f_data; 109 struct pts_softc *psc = tty_softc(tp); 110 int error = 0; 111 char pkt; 112 113 if (uio->uio_resid == 0) 114 return (0); 115 116 tty_lock(tp); 117 118 for (;;) { 119 /* 120 * Implement packet mode. When packet mode is turned on, 121 * the first byte contains a bitmask of events that 122 * occured (start, stop, flush, window size, etc). 123 */ 124 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) { 125 pkt = psc->pts_pkt; 126 psc->pts_pkt = 0; 127 tty_unlock(tp); 128 129 error = ureadc(pkt, uio); 130 return (error); 131 } 132 133 /* 134 * Transmit regular data. 135 * 136 * XXX: We shouldn't use ttydisc_getc_poll()! Even 137 * though in this implementation, there is likely going 138 * to be data, we should just call ttydisc_getc_uio() 139 * and use its return value to sleep. 140 */ 141 if (ttydisc_getc_poll(tp)) { 142 if (psc->pts_flags & PTS_PKT) { 143 /* 144 * XXX: Small race. Fortunately PTY 145 * consumers aren't multithreaded. 146 */ 147 148 tty_unlock(tp); 149 error = ureadc(TIOCPKT_DATA, uio); 150 if (error) 151 return (error); 152 tty_lock(tp); 153 } 154 155 error = ttydisc_getc_uio(tp, uio); 156 break; 157 } 158 159 /* Maybe the device isn't used anyway. */ 160 if (psc->pts_flags & PTS_FINISHED) 161 break; 162 163 /* Wait for more data. */ 164 if (fp->f_flag & O_NONBLOCK) { 165 error = EWOULDBLOCK; 166 break; 167 } 168 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx); 169 if (error != 0) 170 break; 171 } 172 173 tty_unlock(tp); 174 175 return (error); 176 } 177 178 static int 179 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 180 int flags, struct thread *td) 181 { 182 struct tty *tp = fp->f_data; 183 struct pts_softc *psc = tty_softc(tp); 184 char ib[256], *ibstart; 185 size_t iblen, rintlen; 186 int error = 0; 187 188 if (uio->uio_resid == 0) 189 return (0); 190 191 for (;;) { 192 ibstart = ib; 193 iblen = MIN(uio->uio_resid, sizeof ib); 194 error = uiomove(ib, iblen, uio); 195 196 tty_lock(tp); 197 if (error != 0) 198 goto done; 199 200 /* 201 * When possible, avoid the slow path. rint_bypass() 202 * copies all input to the input queue at once. 203 */ 204 MPASS(iblen > 0); 205 do { 206 if (ttydisc_can_bypass(tp)) { 207 /* Store data at once. */ 208 rintlen = ttydisc_rint_bypass(tp, 209 ibstart, iblen); 210 ibstart += rintlen; 211 iblen -= rintlen; 212 213 if (iblen == 0) { 214 /* All data written. */ 215 break; 216 } 217 } else { 218 error = ttydisc_rint(tp, *ibstart, 0); 219 if (error == 0) { 220 /* Character stored successfully. */ 221 ibstart++; 222 iblen--; 223 continue; 224 } 225 } 226 227 /* Maybe the device isn't used anyway. */ 228 if (psc->pts_flags & PTS_FINISHED) { 229 error = EIO; 230 goto done; 231 } 232 233 /* Wait for more data. */ 234 if (fp->f_flag & O_NONBLOCK) { 235 error = EWOULDBLOCK; 236 goto done; 237 } 238 239 /* Wake up users on the slave side. */ 240 ttydisc_rint_done(tp); 241 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx); 242 if (error != 0) 243 goto done; 244 } while (iblen > 0); 245 246 if (uio->uio_resid == 0) 247 break; 248 tty_unlock(tp); 249 } 250 251 done: ttydisc_rint_done(tp); 252 tty_unlock(tp); 253 return (error); 254 } 255 256 static int 257 ptsdev_truncate(struct file *fp, off_t length, struct ucred *active_cred, 258 struct thread *td) 259 { 260 261 return (EINVAL); 262 } 263 264 static int 265 ptsdev_ioctl(struct file *fp, u_long cmd, void *data, 266 struct ucred *active_cred, struct thread *td) 267 { 268 struct tty *tp = fp->f_data; 269 struct pts_softc *psc = tty_softc(tp); 270 int error = 0, sig; 271 272 switch (cmd) { 273 case FIONBIO: 274 /* This device supports non-blocking operation. */ 275 return (0); 276 case FIONREAD: 277 tty_lock(tp); 278 if (psc->pts_flags & PTS_FINISHED) { 279 /* Force read() to be called. */ 280 *(int *)data = 1; 281 } else { 282 *(int *)data = ttydisc_getc_poll(tp); 283 } 284 tty_unlock(tp); 285 return (0); 286 case FIODGNAME: { 287 struct fiodgname_arg *fgn; 288 const char *p; 289 int i; 290 291 /* Reverse device name lookups, for ptsname() and ttyname(). */ 292 fgn = data; 293 p = tty_devname(tp); 294 i = strlen(p) + 1; 295 if (i > fgn->len) 296 return (EINVAL); 297 return copyout(p, fgn->buf, i); 298 } 299 300 /* 301 * We need to implement TIOCGPGRP and TIOCGSID here again. When 302 * called on the pseudo-terminal master, it should not check if 303 * the terminal is the foreground terminal of the calling 304 * process. 305 * 306 * TIOCGETA is also implemented here. Various Linux PTY routines 307 * often call isatty(), which is implemented by tcgetattr(). 308 */ 309 #ifdef PTS_LINUX 310 case TIOCGETA: 311 /* Obtain terminal flags through tcgetattr(). */ 312 tty_lock(tp); 313 *(struct termios*)data = tp->t_termios; 314 tty_unlock(tp); 315 return (0); 316 #endif /* PTS_LINUX */ 317 case TIOCSETAF: 318 case TIOCSETAW: 319 /* 320 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 321 * TCSADRAIN into something different. If an application would 322 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 323 * deadlock waiting for all data to be read. 324 */ 325 cmd = TIOCSETA; 326 break; 327 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 328 case TIOCGPTN: 329 /* 330 * Get the device unit number. 331 */ 332 if (psc->pts_unit < 0) 333 return (ENOTTY); 334 *(unsigned int *)data = psc->pts_unit; 335 return (0); 336 #endif /* PTS_COMPAT || PTS_LINUX */ 337 case TIOCGPGRP: 338 /* Get the foreground process group ID. */ 339 tty_lock(tp); 340 if (tp->t_pgrp != NULL) 341 *(int *)data = tp->t_pgrp->pg_id; 342 else 343 *(int *)data = NO_PID; 344 tty_unlock(tp); 345 return (0); 346 case TIOCGSID: 347 /* Get the session leader process ID. */ 348 tty_lock(tp); 349 if (tp->t_session == NULL) 350 error = ENOTTY; 351 else 352 *(int *)data = tp->t_session->s_sid; 353 tty_unlock(tp); 354 return (error); 355 case TIOCPTMASTER: 356 /* Yes, we are a pseudo-terminal master. */ 357 return (0); 358 case TIOCSIG: 359 /* Signal the foreground process group. */ 360 sig = *(int *)data; 361 if (sig < 1 || sig >= NSIG) 362 return (EINVAL); 363 364 tty_lock(tp); 365 tty_signal_pgrp(tp, sig); 366 tty_unlock(tp); 367 return (0); 368 case TIOCPKT: 369 /* Enable/disable packet mode. */ 370 tty_lock(tp); 371 if (*(int *)data) 372 psc->pts_flags |= PTS_PKT; 373 else 374 psc->pts_flags &= ~PTS_PKT; 375 tty_unlock(tp); 376 return (0); 377 } 378 379 /* Just redirect this ioctl to the slave device. */ 380 tty_lock(tp); 381 error = tty_ioctl(tp, cmd, data, td); 382 tty_unlock(tp); 383 if (error == ENOIOCTL) 384 error = ENOTTY; 385 386 return (error); 387 } 388 389 static int 390 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 391 struct thread *td) 392 { 393 struct tty *tp = fp->f_data; 394 struct pts_softc *psc = tty_softc(tp); 395 int revents = 0; 396 397 tty_lock(tp); 398 399 if (psc->pts_flags & PTS_FINISHED) { 400 /* Slave device is not opened. */ 401 tty_unlock(tp); 402 return (events & 403 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 404 } 405 406 if (events & (POLLIN|POLLRDNORM)) { 407 /* See if we can getc something. */ 408 if (ttydisc_getc_poll(tp) || 409 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 410 revents |= events & (POLLIN|POLLRDNORM); 411 } 412 if (events & (POLLOUT|POLLWRNORM)) { 413 /* See if we can rint something. */ 414 if (ttydisc_rint_poll(tp)) 415 revents |= events & (POLLOUT|POLLWRNORM); 416 } 417 418 /* 419 * No need to check for POLLHUP here. This device cannot be used 420 * as a callout device, which means we always have a carrier, 421 * because the master is. 422 */ 423 424 if (revents == 0) { 425 /* 426 * This code might look misleading, but the naming of 427 * poll events on this side is the opposite of the slave 428 * device. 429 */ 430 if (events & (POLLIN|POLLRDNORM)) 431 selrecord(td, &psc->pts_outpoll); 432 if (events & (POLLOUT|POLLWRNORM)) 433 selrecord(td, &psc->pts_inpoll); 434 } 435 436 tty_unlock(tp); 437 438 return (revents); 439 } 440 441 /* 442 * kqueue support. 443 */ 444 445 static void 446 pts_kqops_read_detach(struct knote *kn) 447 { 448 struct file *fp = kn->kn_fp; 449 struct tty *tp = fp->f_data; 450 struct pts_softc *psc = tty_softc(tp); 451 452 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 453 } 454 455 static int 456 pts_kqops_read_event(struct knote *kn, long hint) 457 { 458 struct file *fp = kn->kn_fp; 459 struct tty *tp = fp->f_data; 460 struct pts_softc *psc = tty_softc(tp); 461 462 if (psc->pts_flags & PTS_FINISHED) { 463 kn->kn_flags |= EV_EOF; 464 return (1); 465 } else { 466 kn->kn_data = ttydisc_getc_poll(tp); 467 return (kn->kn_data > 0); 468 } 469 } 470 471 static void 472 pts_kqops_write_detach(struct knote *kn) 473 { 474 struct file *fp = kn->kn_fp; 475 struct tty *tp = fp->f_data; 476 struct pts_softc *psc = tty_softc(tp); 477 478 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 479 } 480 481 static int 482 pts_kqops_write_event(struct knote *kn, long hint) 483 { 484 struct file *fp = kn->kn_fp; 485 struct tty *tp = fp->f_data; 486 struct pts_softc *psc = tty_softc(tp); 487 488 if (psc->pts_flags & PTS_FINISHED) { 489 kn->kn_flags |= EV_EOF; 490 return (1); 491 } else { 492 kn->kn_data = ttydisc_rint_poll(tp); 493 return (kn->kn_data > 0); 494 } 495 } 496 497 static struct filterops pts_kqops_read = 498 { 1, NULL, pts_kqops_read_detach, pts_kqops_read_event }; 499 static struct filterops pts_kqops_write = 500 { 1, NULL, pts_kqops_write_detach, pts_kqops_write_event }; 501 502 static int 503 ptsdev_kqfilter(struct file *fp, struct knote *kn) 504 { 505 struct tty *tp = fp->f_data; 506 struct pts_softc *psc = tty_softc(tp); 507 int error = 0; 508 509 tty_lock(tp); 510 511 switch (kn->kn_filter) { 512 case EVFILT_READ: 513 kn->kn_fop = &pts_kqops_read; 514 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 515 break; 516 case EVFILT_WRITE: 517 kn->kn_fop = &pts_kqops_write; 518 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 519 break; 520 default: 521 error = EINVAL; 522 break; 523 } 524 525 tty_unlock(tp); 526 return (error); 527 } 528 529 static int 530 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 531 struct thread *td) 532 { 533 struct tty *tp = fp->f_data; 534 #ifdef PTS_EXTERNAL 535 struct pts_softc *psc = tty_softc(tp); 536 #endif /* PTS_EXTERNAL */ 537 struct cdev *dev = tp->t_dev; 538 539 /* 540 * According to POSIX, we must implement an fstat(). This also 541 * makes this implementation compatible with Linux binaries, 542 * because Linux calls fstat() on the pseudo-terminal master to 543 * obtain st_rdev. 544 * 545 * XXX: POSIX also mentions we must fill in st_dev, but how? 546 */ 547 548 bzero(sb, sizeof *sb); 549 #ifdef PTS_EXTERNAL 550 if (psc->pts_cdev != NULL) 551 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 552 else 553 #endif /* PTS_EXTERNAL */ 554 sb->st_ino = sb->st_rdev = tty_udev(tp); 555 556 sb->st_atimespec = dev->si_atime; 557 sb->st_ctimespec = dev->si_ctime; 558 sb->st_mtimespec = dev->si_mtime; 559 sb->st_uid = dev->si_uid; 560 sb->st_gid = dev->si_gid; 561 sb->st_mode = dev->si_mode | S_IFCHR; 562 563 return (0); 564 } 565 566 static int 567 ptsdev_close(struct file *fp, struct thread *td) 568 { 569 struct tty *tp = fp->f_data; 570 571 /* Deallocate TTY device. */ 572 tty_lock(tp); 573 tty_rel_gone(tp); 574 575 return (0); 576 } 577 578 static struct fileops ptsdev_ops = { 579 .fo_read = ptsdev_read, 580 .fo_write = ptsdev_write, 581 .fo_truncate = ptsdev_truncate, 582 .fo_ioctl = ptsdev_ioctl, 583 .fo_poll = ptsdev_poll, 584 .fo_kqfilter = ptsdev_kqfilter, 585 .fo_stat = ptsdev_stat, 586 .fo_close = ptsdev_close, 587 .fo_flags = DFLAG_PASSABLE, 588 }; 589 590 /* 591 * Driver-side hooks. 592 */ 593 594 static void 595 ptsdrv_outwakeup(struct tty *tp) 596 { 597 struct pts_softc *psc = tty_softc(tp); 598 599 cv_broadcast(&psc->pts_outwait); 600 selwakeup(&psc->pts_outpoll); 601 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 602 } 603 604 static void 605 ptsdrv_inwakeup(struct tty *tp) 606 { 607 struct pts_softc *psc = tty_softc(tp); 608 609 cv_broadcast(&psc->pts_inwait); 610 selwakeup(&psc->pts_inpoll); 611 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 612 } 613 614 static int 615 ptsdrv_open(struct tty *tp) 616 { 617 struct pts_softc *psc = tty_softc(tp); 618 619 psc->pts_flags &= ~PTS_FINISHED; 620 621 return (0); 622 } 623 624 static void 625 ptsdrv_close(struct tty *tp) 626 { 627 struct pts_softc *psc = tty_softc(tp); 628 629 /* Wake up any blocked readers/writers. */ 630 psc->pts_flags |= PTS_FINISHED; 631 ptsdrv_outwakeup(tp); 632 ptsdrv_inwakeup(tp); 633 } 634 635 static void 636 ptsdrv_pktnotify(struct tty *tp, char event) 637 { 638 struct pts_softc *psc = tty_softc(tp); 639 640 /* 641 * Clear conflicting flags. 642 */ 643 644 switch (event) { 645 case TIOCPKT_STOP: 646 psc->pts_pkt &= ~TIOCPKT_START; 647 break; 648 case TIOCPKT_START: 649 psc->pts_pkt &= ~TIOCPKT_STOP; 650 break; 651 case TIOCPKT_NOSTOP: 652 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 653 break; 654 case TIOCPKT_DOSTOP: 655 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 656 break; 657 } 658 659 psc->pts_pkt |= event; 660 ptsdrv_outwakeup(tp); 661 } 662 663 static void 664 ptsdrv_free(void *softc) 665 { 666 struct pts_softc *psc = softc; 667 668 /* Make device number available again. */ 669 if (psc->pts_unit >= 0) 670 free_unr(pts_pool, psc->pts_unit); 671 672 chgptscnt(psc->pts_uidinfo, -1, 0); 673 uifree(psc->pts_uidinfo); 674 675 knlist_destroy(&psc->pts_inpoll.si_note); 676 knlist_destroy(&psc->pts_outpoll.si_note); 677 678 #ifdef PTS_EXTERNAL 679 /* Destroy master device as well. */ 680 if (psc->pts_cdev != NULL) 681 destroy_dev_sched(psc->pts_cdev); 682 #endif /* PTS_EXTERNAL */ 683 684 free(psc, M_PTS); 685 } 686 687 static struct ttydevsw pts_class = { 688 .tsw_flags = TF_NOPREFIX, 689 .tsw_outwakeup = ptsdrv_outwakeup, 690 .tsw_inwakeup = ptsdrv_inwakeup, 691 .tsw_open = ptsdrv_open, 692 .tsw_close = ptsdrv_close, 693 .tsw_pktnotify = ptsdrv_pktnotify, 694 .tsw_free = ptsdrv_free, 695 }; 696 697 static int 698 pts_alloc(int fflags, struct thread *td, struct file *fp) 699 { 700 int unit, ok; 701 struct tty *tp; 702 struct pts_softc *psc; 703 struct proc *p = td->td_proc; 704 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 705 706 /* Resource limiting. */ 707 PROC_LOCK(p); 708 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 709 PROC_UNLOCK(p); 710 if (!ok) 711 return (EAGAIN); 712 713 /* Try to allocate a new pts unit number. */ 714 unit = alloc_unr(pts_pool); 715 if (unit < 0) { 716 chgptscnt(uid, -1, 0); 717 return (EAGAIN); 718 } 719 720 /* Allocate TTY and softc. */ 721 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 722 cv_init(&psc->pts_inwait, "pts inwait"); 723 cv_init(&psc->pts_outwait, "pts outwait"); 724 725 psc->pts_unit = unit; 726 psc->pts_uidinfo = uid; 727 uihold(uid); 728 729 tp = tty_alloc(&pts_class, psc, NULL); 730 knlist_init(&psc->pts_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL); 731 knlist_init(&psc->pts_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL); 732 733 /* Expose the slave device as well. */ 734 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 735 736 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 737 738 return (0); 739 } 740 741 #ifdef PTS_EXTERNAL 742 int 743 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 744 struct cdev *dev, const char *name) 745 { 746 int ok; 747 struct tty *tp; 748 struct pts_softc *psc; 749 struct proc *p = td->td_proc; 750 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 751 752 /* Resource limiting. */ 753 PROC_LOCK(p); 754 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 755 PROC_UNLOCK(p); 756 if (!ok) 757 return (EAGAIN); 758 759 /* Allocate TTY and softc. */ 760 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 761 cv_init(&psc->pts_inwait, "pts inwait"); 762 cv_init(&psc->pts_outwait, "pts outwait"); 763 764 psc->pts_unit = -1; 765 psc->pts_cdev = dev; 766 psc->pts_uidinfo = uid; 767 uihold(uid); 768 769 tp = tty_alloc(&pts_class, psc, NULL); 770 knlist_init(&psc->pts_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL); 771 knlist_init(&psc->pts_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL); 772 773 /* Expose the slave device as well. */ 774 tty_makedev(tp, td->td_ucred, "%s", name); 775 776 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 777 778 return (0); 779 } 780 #endif /* PTS_EXTERNAL */ 781 782 int 783 posix_openpt(struct thread *td, struct posix_openpt_args *uap) 784 { 785 int error, fd; 786 struct file *fp; 787 788 /* 789 * POSIX states it's unspecified when other flags are passed. We 790 * don't allow this. 791 */ 792 if (uap->flags & ~(O_RDWR|O_NOCTTY)) 793 return (EINVAL); 794 795 error = falloc(td, &fp, &fd); 796 if (error) 797 return (error); 798 799 /* Allocate the actual pseudo-TTY. */ 800 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 801 if (error != 0) { 802 fdclose(td->td_proc->p_fd, fp, fd, td); 803 return (error); 804 } 805 806 /* Pass it back to userspace. */ 807 td->td_retval[0] = fd; 808 fdrop(fp, td); 809 810 return (0); 811 } 812 813 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 814 static int 815 ptmx_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp) 816 { 817 818 return (pts_alloc(fflags & (FREAD|FWRITE), td, fp)); 819 } 820 821 static struct cdevsw ptmx_cdevsw = { 822 .d_version = D_VERSION, 823 .d_fdopen = ptmx_fdopen, 824 .d_name = "ptmx", 825 }; 826 #endif /* PTS_COMPAT || PTS_LINUX */ 827 828 static void 829 pts_init(void *unused) 830 { 831 832 pts_pool = new_unrhdr(0, MAXPTSDEVS, NULL); 833 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 834 make_dev(&ptmx_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "ptmx"); 835 #endif /* PTS_COMPAT || PTS_LINUX */ 836 } 837 838 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 839