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/limits.h> 54 #include <sys/malloc.h> 55 #include <sys/poll.h> 56 #include <sys/proc.h> 57 #include <sys/resourcevar.h> 58 #include <sys/serial.h> 59 #include <sys/stat.h> 60 #include <sys/syscall.h> 61 #include <sys/syscallsubr.h> 62 #include <sys/sysctl.h> 63 #include <sys/sysent.h> 64 #include <sys/sysproto.h> 65 #include <sys/systm.h> 66 #include <sys/tty.h> 67 #include <sys/ttycom.h> 68 69 #include <machine/stdarg.h> 70 71 /* 72 * Our utmp(5) format is limited to 8-byte TTY line names. This means 73 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow 74 * users to increase this number, assuming they have manually increased 75 * UT_LINESIZE. 76 */ 77 static struct unrhdr *pts_pool; 78 static unsigned int pts_maxdev = 999; 79 SYSCTL_UINT(_kern, OID_AUTO, pts_maxdev, CTLFLAG_RW, &pts_maxdev, 0, 80 "Maximum amount of pts(4) pseudo-terminals"); 81 82 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); 83 84 /* 85 * Per-PTS structure. 86 * 87 * List of locks 88 * (t) locked by tty_lock() 89 * (c) const until freeing 90 */ 91 struct pts_softc { 92 int pts_unit; /* (c) Device unit number. */ 93 unsigned int pts_flags; /* (t) Device flags. */ 94 #define PTS_PKT 0x1 /* Packet mode. */ 95 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */ 96 char pts_pkt; /* (t) Unread packet mode data. */ 97 98 struct cv pts_inwait; /* (t) Blocking write() on master. */ 99 struct selinfo pts_inpoll; /* (t) Select queue for write(). */ 100 struct cv pts_outwait; /* (t) Blocking read() on master. */ 101 struct selinfo pts_outpoll; /* (t) Select queue for read(). */ 102 103 #ifdef PTS_EXTERNAL 104 struct cdev *pts_cdev; /* (c) Master device node. */ 105 #endif /* PTS_EXTERNAL */ 106 107 struct uidinfo *pts_uidinfo; /* (c) Resource limit. */ 108 }; 109 110 /* 111 * Controller-side file operations. 112 */ 113 114 static int 115 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 116 int flags, struct thread *td) 117 { 118 struct tty *tp = fp->f_data; 119 struct pts_softc *psc = tty_softc(tp); 120 int error = 0; 121 char pkt; 122 123 if (uio->uio_resid == 0) 124 return (0); 125 126 tty_lock(tp); 127 128 for (;;) { 129 /* 130 * Implement packet mode. When packet mode is turned on, 131 * the first byte contains a bitmask of events that 132 * occured (start, stop, flush, window size, etc). 133 */ 134 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) { 135 pkt = psc->pts_pkt; 136 psc->pts_pkt = 0; 137 tty_unlock(tp); 138 139 error = ureadc(pkt, uio); 140 return (error); 141 } 142 143 /* 144 * Transmit regular data. 145 * 146 * XXX: We shouldn't use ttydisc_getc_poll()! Even 147 * though in this implementation, there is likely going 148 * to be data, we should just call ttydisc_getc_uio() 149 * and use its return value to sleep. 150 */ 151 if (ttydisc_getc_poll(tp)) { 152 if (psc->pts_flags & PTS_PKT) { 153 /* 154 * XXX: Small race. Fortunately PTY 155 * consumers aren't multithreaded. 156 */ 157 158 tty_unlock(tp); 159 error = ureadc(TIOCPKT_DATA, uio); 160 if (error) 161 return (error); 162 tty_lock(tp); 163 } 164 165 error = ttydisc_getc_uio(tp, uio); 166 break; 167 } 168 169 /* Maybe the device isn't used anyway. */ 170 if (psc->pts_flags & PTS_FINISHED) 171 break; 172 173 /* Wait for more data. */ 174 if (fp->f_flag & O_NONBLOCK) { 175 error = EWOULDBLOCK; 176 break; 177 } 178 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx); 179 if (error != 0) 180 break; 181 } 182 183 tty_unlock(tp); 184 185 return (error); 186 } 187 188 static int 189 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 190 int flags, struct thread *td) 191 { 192 struct tty *tp = fp->f_data; 193 struct pts_softc *psc = tty_softc(tp); 194 char ib[256], *ibstart; 195 size_t iblen, rintlen; 196 int error = 0; 197 198 if (uio->uio_resid == 0) 199 return (0); 200 201 for (;;) { 202 ibstart = ib; 203 iblen = MIN(uio->uio_resid, sizeof ib); 204 error = uiomove(ib, iblen, uio); 205 206 tty_lock(tp); 207 if (error != 0) { 208 iblen = 0; 209 goto done; 210 } 211 212 /* 213 * When possible, avoid the slow path. rint_bypass() 214 * copies all input to the input queue at once. 215 */ 216 MPASS(iblen > 0); 217 do { 218 if (ttydisc_can_bypass(tp)) { 219 /* Store data at once. */ 220 rintlen = ttydisc_rint_bypass(tp, 221 ibstart, iblen); 222 ibstart += rintlen; 223 iblen -= rintlen; 224 225 if (iblen == 0) { 226 /* All data written. */ 227 break; 228 } 229 } else { 230 error = ttydisc_rint(tp, *ibstart, 0); 231 if (error == 0) { 232 /* Character stored successfully. */ 233 ibstart++; 234 iblen--; 235 continue; 236 } 237 } 238 239 /* Maybe the device isn't used anyway. */ 240 if (psc->pts_flags & PTS_FINISHED) { 241 error = EIO; 242 goto done; 243 } 244 245 /* Wait for more data. */ 246 if (fp->f_flag & O_NONBLOCK) { 247 error = EWOULDBLOCK; 248 goto done; 249 } 250 251 /* Wake up users on the slave side. */ 252 ttydisc_rint_done(tp); 253 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx); 254 if (error != 0) 255 goto done; 256 } while (iblen > 0); 257 258 if (uio->uio_resid == 0) 259 break; 260 tty_unlock(tp); 261 } 262 263 done: ttydisc_rint_done(tp); 264 tty_unlock(tp); 265 266 /* 267 * Don't account for the part of the buffer that we couldn't 268 * pass to the TTY. 269 */ 270 uio->uio_resid += iblen; 271 return (error); 272 } 273 274 static int 275 ptsdev_truncate(struct file *fp, off_t length, struct ucred *active_cred, 276 struct thread *td) 277 { 278 279 return (EINVAL); 280 } 281 282 static int 283 ptsdev_ioctl(struct file *fp, u_long cmd, void *data, 284 struct ucred *active_cred, struct thread *td) 285 { 286 struct tty *tp = fp->f_data; 287 struct pts_softc *psc = tty_softc(tp); 288 int error = 0, sig; 289 290 switch (cmd) { 291 case FIONBIO: 292 /* This device supports non-blocking operation. */ 293 return (0); 294 case FIONREAD: 295 tty_lock(tp); 296 if (psc->pts_flags & PTS_FINISHED) { 297 /* Force read() to be called. */ 298 *(int *)data = 1; 299 } else { 300 *(int *)data = ttydisc_getc_poll(tp); 301 } 302 tty_unlock(tp); 303 return (0); 304 case FIODGNAME: { 305 struct fiodgname_arg *fgn; 306 const char *p; 307 int i; 308 309 /* Reverse device name lookups, for ptsname() and ttyname(). */ 310 fgn = data; 311 p = tty_devname(tp); 312 i = strlen(p) + 1; 313 if (i > fgn->len) 314 return (EINVAL); 315 return copyout(p, fgn->buf, i); 316 } 317 318 /* 319 * We need to implement TIOCGPGRP and TIOCGSID here again. When 320 * called on the pseudo-terminal master, it should not check if 321 * the terminal is the foreground terminal of the calling 322 * process. 323 * 324 * TIOCGETA is also implemented here. Various Linux PTY routines 325 * often call isatty(), which is implemented by tcgetattr(). 326 */ 327 #ifdef PTS_LINUX 328 case TIOCGETA: 329 /* Obtain terminal flags through tcgetattr(). */ 330 tty_lock(tp); 331 *(struct termios*)data = tp->t_termios; 332 tty_unlock(tp); 333 return (0); 334 #endif /* PTS_LINUX */ 335 case TIOCSETAF: 336 case TIOCSETAW: 337 /* 338 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 339 * TCSADRAIN into something different. If an application would 340 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 341 * deadlock waiting for all data to be read. 342 */ 343 cmd = TIOCSETA; 344 break; 345 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 346 case TIOCGPTN: 347 /* 348 * Get the device unit number. 349 */ 350 if (psc->pts_unit < 0) 351 return (ENOTTY); 352 *(unsigned int *)data = psc->pts_unit; 353 return (0); 354 #endif /* PTS_COMPAT || PTS_LINUX */ 355 case TIOCGPGRP: 356 /* Get the foreground process group ID. */ 357 tty_lock(tp); 358 if (tp->t_pgrp != NULL) 359 *(int *)data = tp->t_pgrp->pg_id; 360 else 361 *(int *)data = NO_PID; 362 tty_unlock(tp); 363 return (0); 364 case TIOCGSID: 365 /* Get the session leader process ID. */ 366 tty_lock(tp); 367 if (tp->t_session == NULL) 368 error = ENOTTY; 369 else 370 *(int *)data = tp->t_session->s_sid; 371 tty_unlock(tp); 372 return (error); 373 case TIOCPTMASTER: 374 /* Yes, we are a pseudo-terminal master. */ 375 return (0); 376 case TIOCSIG: 377 /* Signal the foreground process group. */ 378 sig = *(int *)data; 379 if (sig < 1 || sig >= NSIG) 380 return (EINVAL); 381 382 tty_lock(tp); 383 tty_signal_pgrp(tp, sig); 384 tty_unlock(tp); 385 return (0); 386 case TIOCPKT: 387 /* Enable/disable packet mode. */ 388 tty_lock(tp); 389 if (*(int *)data) 390 psc->pts_flags |= PTS_PKT; 391 else 392 psc->pts_flags &= ~PTS_PKT; 393 tty_unlock(tp); 394 return (0); 395 } 396 397 /* Just redirect this ioctl to the slave device. */ 398 tty_lock(tp); 399 error = tty_ioctl(tp, cmd, data, td); 400 tty_unlock(tp); 401 if (error == ENOIOCTL) 402 error = ENOTTY; 403 404 return (error); 405 } 406 407 static int 408 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 409 struct thread *td) 410 { 411 struct tty *tp = fp->f_data; 412 struct pts_softc *psc = tty_softc(tp); 413 int revents = 0; 414 415 tty_lock(tp); 416 417 if (psc->pts_flags & PTS_FINISHED) { 418 /* Slave device is not opened. */ 419 tty_unlock(tp); 420 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP); 421 } 422 423 if (events & (POLLIN|POLLRDNORM)) { 424 /* See if we can getc something. */ 425 if (ttydisc_getc_poll(tp) || 426 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 427 revents |= events & (POLLIN|POLLRDNORM); 428 } 429 if (events & (POLLOUT|POLLWRNORM)) { 430 /* See if we can rint something. */ 431 if (ttydisc_rint_poll(tp)) 432 revents |= events & (POLLOUT|POLLWRNORM); 433 } 434 435 /* 436 * No need to check for POLLHUP here. This device cannot be used 437 * as a callout device, which means we always have a carrier, 438 * because the master is. 439 */ 440 441 if (revents == 0) { 442 /* 443 * This code might look misleading, but the naming of 444 * poll events on this side is the opposite of the slave 445 * device. 446 */ 447 if (events & (POLLIN|POLLRDNORM)) 448 selrecord(td, &psc->pts_outpoll); 449 if (events & (POLLOUT|POLLWRNORM)) 450 selrecord(td, &psc->pts_inpoll); 451 } 452 453 tty_unlock(tp); 454 455 return (revents); 456 } 457 458 /* 459 * kqueue support. 460 */ 461 462 static void 463 pts_kqops_read_detach(struct knote *kn) 464 { 465 struct file *fp = kn->kn_fp; 466 struct tty *tp = fp->f_data; 467 struct pts_softc *psc = tty_softc(tp); 468 469 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 470 } 471 472 static int 473 pts_kqops_read_event(struct knote *kn, long hint) 474 { 475 struct file *fp = kn->kn_fp; 476 struct tty *tp = fp->f_data; 477 struct pts_softc *psc = tty_softc(tp); 478 479 if (psc->pts_flags & PTS_FINISHED) { 480 kn->kn_flags |= EV_EOF; 481 return (1); 482 } else { 483 kn->kn_data = ttydisc_getc_poll(tp); 484 return (kn->kn_data > 0); 485 } 486 } 487 488 static void 489 pts_kqops_write_detach(struct knote *kn) 490 { 491 struct file *fp = kn->kn_fp; 492 struct tty *tp = fp->f_data; 493 struct pts_softc *psc = tty_softc(tp); 494 495 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 496 } 497 498 static int 499 pts_kqops_write_event(struct knote *kn, long hint) 500 { 501 struct file *fp = kn->kn_fp; 502 struct tty *tp = fp->f_data; 503 struct pts_softc *psc = tty_softc(tp); 504 505 if (psc->pts_flags & PTS_FINISHED) { 506 kn->kn_flags |= EV_EOF; 507 return (1); 508 } else { 509 kn->kn_data = ttydisc_rint_poll(tp); 510 return (kn->kn_data > 0); 511 } 512 } 513 514 static struct filterops pts_kqops_read = 515 { 1, NULL, pts_kqops_read_detach, pts_kqops_read_event }; 516 static struct filterops pts_kqops_write = 517 { 1, NULL, pts_kqops_write_detach, pts_kqops_write_event }; 518 519 static int 520 ptsdev_kqfilter(struct file *fp, struct knote *kn) 521 { 522 struct tty *tp = fp->f_data; 523 struct pts_softc *psc = tty_softc(tp); 524 int error = 0; 525 526 tty_lock(tp); 527 528 switch (kn->kn_filter) { 529 case EVFILT_READ: 530 kn->kn_fop = &pts_kqops_read; 531 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 532 break; 533 case EVFILT_WRITE: 534 kn->kn_fop = &pts_kqops_write; 535 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 536 break; 537 default: 538 error = EINVAL; 539 break; 540 } 541 542 tty_unlock(tp); 543 return (error); 544 } 545 546 static int 547 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 548 struct thread *td) 549 { 550 struct tty *tp = fp->f_data; 551 #ifdef PTS_EXTERNAL 552 struct pts_softc *psc = tty_softc(tp); 553 #endif /* PTS_EXTERNAL */ 554 struct cdev *dev = tp->t_dev; 555 556 /* 557 * According to POSIX, we must implement an fstat(). This also 558 * makes this implementation compatible with Linux binaries, 559 * because Linux calls fstat() on the pseudo-terminal master to 560 * obtain st_rdev. 561 * 562 * XXX: POSIX also mentions we must fill in st_dev, but how? 563 */ 564 565 bzero(sb, sizeof *sb); 566 #ifdef PTS_EXTERNAL 567 if (psc->pts_cdev != NULL) 568 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 569 else 570 #endif /* PTS_EXTERNAL */ 571 sb->st_ino = sb->st_rdev = tty_udev(tp); 572 573 sb->st_atimespec = dev->si_atime; 574 sb->st_ctimespec = dev->si_ctime; 575 sb->st_mtimespec = dev->si_mtime; 576 sb->st_uid = dev->si_uid; 577 sb->st_gid = dev->si_gid; 578 sb->st_mode = dev->si_mode | S_IFCHR; 579 580 return (0); 581 } 582 583 static int 584 ptsdev_close(struct file *fp, struct thread *td) 585 { 586 struct tty *tp = fp->f_data; 587 588 /* Deallocate TTY device. */ 589 tty_lock(tp); 590 tty_rel_gone(tp); 591 592 return (0); 593 } 594 595 static struct fileops ptsdev_ops = { 596 .fo_read = ptsdev_read, 597 .fo_write = ptsdev_write, 598 .fo_truncate = ptsdev_truncate, 599 .fo_ioctl = ptsdev_ioctl, 600 .fo_poll = ptsdev_poll, 601 .fo_kqfilter = ptsdev_kqfilter, 602 .fo_stat = ptsdev_stat, 603 .fo_close = ptsdev_close, 604 .fo_flags = DFLAG_PASSABLE, 605 }; 606 607 /* 608 * Driver-side hooks. 609 */ 610 611 static void 612 ptsdrv_outwakeup(struct tty *tp) 613 { 614 struct pts_softc *psc = tty_softc(tp); 615 616 cv_broadcast(&psc->pts_outwait); 617 selwakeup(&psc->pts_outpoll); 618 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 619 } 620 621 static void 622 ptsdrv_inwakeup(struct tty *tp) 623 { 624 struct pts_softc *psc = tty_softc(tp); 625 626 cv_broadcast(&psc->pts_inwait); 627 selwakeup(&psc->pts_inpoll); 628 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 629 } 630 631 static int 632 ptsdrv_open(struct tty *tp) 633 { 634 struct pts_softc *psc = tty_softc(tp); 635 636 psc->pts_flags &= ~PTS_FINISHED; 637 638 return (0); 639 } 640 641 static void 642 ptsdrv_close(struct tty *tp) 643 { 644 struct pts_softc *psc = tty_softc(tp); 645 646 /* Wake up any blocked readers/writers. */ 647 psc->pts_flags |= PTS_FINISHED; 648 ptsdrv_outwakeup(tp); 649 ptsdrv_inwakeup(tp); 650 } 651 652 static void 653 ptsdrv_pktnotify(struct tty *tp, char event) 654 { 655 struct pts_softc *psc = tty_softc(tp); 656 657 /* 658 * Clear conflicting flags. 659 */ 660 661 switch (event) { 662 case TIOCPKT_STOP: 663 psc->pts_pkt &= ~TIOCPKT_START; 664 break; 665 case TIOCPKT_START: 666 psc->pts_pkt &= ~TIOCPKT_STOP; 667 break; 668 case TIOCPKT_NOSTOP: 669 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 670 break; 671 case TIOCPKT_DOSTOP: 672 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 673 break; 674 } 675 676 psc->pts_pkt |= event; 677 ptsdrv_outwakeup(tp); 678 } 679 680 static void 681 ptsdrv_free(void *softc) 682 { 683 struct pts_softc *psc = softc; 684 685 /* Make device number available again. */ 686 if (psc->pts_unit >= 0) 687 free_unr(pts_pool, psc->pts_unit); 688 689 chgptscnt(psc->pts_uidinfo, -1, 0); 690 uifree(psc->pts_uidinfo); 691 692 knlist_destroy(&psc->pts_inpoll.si_note); 693 knlist_destroy(&psc->pts_outpoll.si_note); 694 695 #ifdef PTS_EXTERNAL 696 /* Destroy master device as well. */ 697 if (psc->pts_cdev != NULL) 698 destroy_dev_sched(psc->pts_cdev); 699 #endif /* PTS_EXTERNAL */ 700 701 free(psc, M_PTS); 702 } 703 704 static struct ttydevsw pts_class = { 705 .tsw_flags = TF_NOPREFIX, 706 .tsw_outwakeup = ptsdrv_outwakeup, 707 .tsw_inwakeup = ptsdrv_inwakeup, 708 .tsw_open = ptsdrv_open, 709 .tsw_close = ptsdrv_close, 710 .tsw_pktnotify = ptsdrv_pktnotify, 711 .tsw_free = ptsdrv_free, 712 }; 713 714 static int 715 pts_alloc(int fflags, struct thread *td, struct file *fp) 716 { 717 int unit, ok; 718 struct tty *tp; 719 struct pts_softc *psc; 720 struct proc *p = td->td_proc; 721 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 722 723 /* Resource limiting. */ 724 PROC_LOCK(p); 725 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 726 PROC_UNLOCK(p); 727 if (!ok) 728 return (EAGAIN); 729 730 /* Try to allocate a new pts unit number. */ 731 unit = alloc_unr(pts_pool); 732 if (unit < 0) { 733 chgptscnt(uid, -1, 0); 734 return (EAGAIN); 735 } 736 if (unit > pts_maxdev) { 737 free_unr(pts_pool, unit); 738 chgptscnt(uid, -1, 0); 739 return (EAGAIN); 740 } 741 742 /* Allocate TTY and softc. */ 743 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 744 cv_init(&psc->pts_inwait, "pts inwait"); 745 cv_init(&psc->pts_outwait, "pts outwait"); 746 747 psc->pts_unit = unit; 748 psc->pts_uidinfo = uid; 749 uihold(uid); 750 751 tp = tty_alloc(&pts_class, psc); 752 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 753 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 754 755 /* Expose the slave device as well. */ 756 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 757 758 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 759 760 return (0); 761 } 762 763 #ifdef PTS_EXTERNAL 764 int 765 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 766 struct cdev *dev, const char *name) 767 { 768 int ok; 769 struct tty *tp; 770 struct pts_softc *psc; 771 struct proc *p = td->td_proc; 772 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 773 774 /* Resource limiting. */ 775 PROC_LOCK(p); 776 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 777 PROC_UNLOCK(p); 778 if (!ok) 779 return (EAGAIN); 780 781 /* Allocate TTY and softc. */ 782 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 783 cv_init(&psc->pts_inwait, "pts inwait"); 784 cv_init(&psc->pts_outwait, "pts outwait"); 785 786 psc->pts_unit = -1; 787 psc->pts_cdev = dev; 788 psc->pts_uidinfo = uid; 789 uihold(uid); 790 791 tp = tty_alloc(&pts_class, psc); 792 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 793 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 794 795 /* Expose the slave device as well. */ 796 tty_makedev(tp, td->td_ucred, "%s", name); 797 798 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 799 800 return (0); 801 } 802 #endif /* PTS_EXTERNAL */ 803 804 int 805 posix_openpt(struct thread *td, struct posix_openpt_args *uap) 806 { 807 int error, fd; 808 struct file *fp; 809 810 /* 811 * POSIX states it's unspecified when other flags are passed. We 812 * don't allow this. 813 */ 814 if (uap->flags & ~(O_RDWR|O_NOCTTY)) 815 return (EINVAL); 816 817 error = falloc(td, &fp, &fd); 818 if (error) 819 return (error); 820 821 /* Allocate the actual pseudo-TTY. */ 822 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 823 if (error != 0) { 824 fdclose(td->td_proc->p_fd, fp, fd, td); 825 return (error); 826 } 827 828 /* Pass it back to userspace. */ 829 td->td_retval[0] = fd; 830 fdrop(fp, td); 831 832 return (0); 833 } 834 835 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 836 static int 837 ptmx_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp) 838 { 839 840 return (pts_alloc(fflags & (FREAD|FWRITE), td, fp)); 841 } 842 843 static struct cdevsw ptmx_cdevsw = { 844 .d_version = D_VERSION, 845 .d_fdopen = ptmx_fdopen, 846 .d_name = "ptmx", 847 }; 848 #endif /* PTS_COMPAT || PTS_LINUX */ 849 850 static void 851 pts_init(void *unused) 852 { 853 854 pts_pool = new_unrhdr(0, INT_MAX, NULL); 855 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 856 make_dev(&ptmx_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "ptmx"); 857 #endif /* PTS_COMPAT || PTS_LINUX */ 858 } 859 860 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 861