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 /* Add compatibility bits for FreeBSD. */ 34 #define PTS_COMPAT 35 /* Add pty(4) compat bits. */ 36 #define PTS_EXTERNAL 37 /* Add bits to make Linux binaries work. */ 38 #define PTS_LINUX 39 40 #include <sys/param.h> 41 #include <sys/lock.h> 42 #include <sys/condvar.h> 43 #include <sys/conf.h> 44 #include <sys/fcntl.h> 45 #include <sys/file.h> 46 #include <sys/filedesc.h> 47 #include <sys/filio.h> 48 #include <sys/kernel.h> 49 #include <sys/limits.h> 50 #include <sys/malloc.h> 51 #include <sys/poll.h> 52 #include <sys/proc.h> 53 #include <sys/resourcevar.h> 54 #include <sys/serial.h> 55 #include <sys/stat.h> 56 #include <sys/syscall.h> 57 #include <sys/syscallsubr.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/sysproto.h> 61 #include <sys/systm.h> 62 #include <sys/tty.h> 63 #include <sys/ttycom.h> 64 65 #include <machine/stdarg.h> 66 67 /* 68 * Our utmp(5) format is limited to 8-byte TTY line names. This means 69 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow 70 * users to increase this number, assuming they have manually increased 71 * UT_LINESIZE. 72 */ 73 static struct unrhdr *pts_pool; 74 static unsigned int pts_maxdev = 999; 75 SYSCTL_UINT(_kern, OID_AUTO, pts_maxdev, CTLFLAG_RW, &pts_maxdev, 0, 76 "Maximum amount of pts(4) pseudo-terminals"); 77 78 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); 79 80 /* 81 * Per-PTS structure. 82 * 83 * List of locks 84 * (t) locked by tty_lock() 85 * (c) const until freeing 86 */ 87 struct pts_softc { 88 int pts_unit; /* (c) Device unit number. */ 89 unsigned int pts_flags; /* (t) Device flags. */ 90 #define PTS_PKT 0x1 /* Packet mode. */ 91 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */ 92 char pts_pkt; /* (t) Unread packet mode data. */ 93 94 struct cv pts_inwait; /* (t) Blocking write() on master. */ 95 struct selinfo pts_inpoll; /* (t) Select queue for write(). */ 96 struct cv pts_outwait; /* (t) Blocking read() on master. */ 97 struct selinfo pts_outpoll; /* (t) Select queue for read(). */ 98 99 #ifdef PTS_EXTERNAL 100 struct cdev *pts_cdev; /* (c) Master device node. */ 101 #endif /* PTS_EXTERNAL */ 102 103 struct uidinfo *pts_uidinfo; /* (c) Resource limit. */ 104 }; 105 106 /* 107 * Controller-side file operations. 108 */ 109 110 static int 111 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 112 int flags, struct thread *td) 113 { 114 struct tty *tp = fp->f_data; 115 struct pts_softc *psc = tty_softc(tp); 116 int error = 0; 117 char pkt; 118 119 if (uio->uio_resid == 0) 120 return (0); 121 122 tty_lock(tp); 123 124 for (;;) { 125 /* 126 * Implement packet mode. When packet mode is turned on, 127 * the first byte contains a bitmask of events that 128 * occured (start, stop, flush, window size, etc). 129 */ 130 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) { 131 pkt = psc->pts_pkt; 132 psc->pts_pkt = 0; 133 tty_unlock(tp); 134 135 error = ureadc(pkt, uio); 136 return (error); 137 } 138 139 /* 140 * Transmit regular data. 141 * 142 * XXX: We shouldn't use ttydisc_getc_poll()! Even 143 * though in this implementation, there is likely going 144 * to be data, we should just call ttydisc_getc_uio() 145 * and use its return value to sleep. 146 */ 147 if (ttydisc_getc_poll(tp)) { 148 if (psc->pts_flags & PTS_PKT) { 149 /* 150 * XXX: Small race. Fortunately PTY 151 * consumers aren't multithreaded. 152 */ 153 154 tty_unlock(tp); 155 error = ureadc(TIOCPKT_DATA, uio); 156 if (error) 157 return (error); 158 tty_lock(tp); 159 } 160 161 error = ttydisc_getc_uio(tp, uio); 162 break; 163 } 164 165 /* Maybe the device isn't used anyway. */ 166 if (psc->pts_flags & PTS_FINISHED) 167 break; 168 169 /* Wait for more data. */ 170 if (fp->f_flag & O_NONBLOCK) { 171 error = EWOULDBLOCK; 172 break; 173 } 174 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx); 175 if (error != 0) 176 break; 177 } 178 179 tty_unlock(tp); 180 181 return (error); 182 } 183 184 static int 185 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 186 int flags, struct thread *td) 187 { 188 struct tty *tp = fp->f_data; 189 struct pts_softc *psc = tty_softc(tp); 190 char ib[256], *ibstart; 191 size_t iblen, rintlen; 192 int error = 0; 193 194 if (uio->uio_resid == 0) 195 return (0); 196 197 for (;;) { 198 ibstart = ib; 199 iblen = MIN(uio->uio_resid, sizeof ib); 200 error = uiomove(ib, iblen, uio); 201 202 tty_lock(tp); 203 if (error != 0) { 204 iblen = 0; 205 goto done; 206 } 207 208 /* 209 * When possible, avoid the slow path. rint_bypass() 210 * copies all input to the input queue at once. 211 */ 212 MPASS(iblen > 0); 213 do { 214 rintlen = ttydisc_rint_simple(tp, ibstart, iblen); 215 ibstart += rintlen; 216 iblen -= rintlen; 217 if (iblen == 0) { 218 /* All data written. */ 219 break; 220 } 221 222 /* Maybe the device isn't used anyway. */ 223 if (psc->pts_flags & PTS_FINISHED) { 224 error = EIO; 225 goto done; 226 } 227 228 /* Wait for more data. */ 229 if (fp->f_flag & O_NONBLOCK) { 230 error = EWOULDBLOCK; 231 goto done; 232 } 233 234 /* Wake up users on the slave side. */ 235 ttydisc_rint_done(tp); 236 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx); 237 if (error != 0) 238 goto done; 239 } while (iblen > 0); 240 241 if (uio->uio_resid == 0) 242 break; 243 tty_unlock(tp); 244 } 245 246 done: ttydisc_rint_done(tp); 247 tty_unlock(tp); 248 249 /* 250 * Don't account for the part of the buffer that we couldn't 251 * pass to the TTY. 252 */ 253 uio->uio_resid += iblen; 254 return (error); 255 } 256 257 static int 258 ptsdev_truncate(struct file *fp, off_t length, struct ucred *active_cred, 259 struct thread *td) 260 { 261 262 return (EINVAL); 263 } 264 265 static int 266 ptsdev_ioctl(struct file *fp, u_long cmd, void *data, 267 struct ucred *active_cred, struct thread *td) 268 { 269 struct tty *tp = fp->f_data; 270 struct pts_softc *psc = tty_softc(tp); 271 int error = 0, sig; 272 273 switch (cmd) { 274 case FIONBIO: 275 /* This device supports non-blocking operation. */ 276 return (0); 277 case FIONREAD: 278 tty_lock(tp); 279 if (psc->pts_flags & PTS_FINISHED) { 280 /* Force read() to be called. */ 281 *(int *)data = 1; 282 } else { 283 *(int *)data = ttydisc_getc_poll(tp); 284 } 285 tty_unlock(tp); 286 return (0); 287 case FIODGNAME: { 288 struct fiodgname_arg *fgn; 289 const char *p; 290 int i; 291 292 /* Reverse device name lookups, for ptsname() and ttyname(). */ 293 fgn = data; 294 p = tty_devname(tp); 295 i = strlen(p) + 1; 296 if (i > fgn->len) 297 return (EINVAL); 298 return copyout(p, fgn->buf, i); 299 } 300 301 /* 302 * We need to implement TIOCGPGRP and TIOCGSID here again. When 303 * called on the pseudo-terminal master, it should not check if 304 * the terminal is the foreground terminal of the calling 305 * process. 306 * 307 * TIOCGETA is also implemented here. Various Linux PTY routines 308 * often call isatty(), which is implemented by tcgetattr(). 309 */ 310 #ifdef PTS_LINUX 311 case TIOCGETA: 312 /* Obtain terminal flags through tcgetattr(). */ 313 tty_lock(tp); 314 *(struct termios*)data = tp->t_termios; 315 tty_unlock(tp); 316 return (0); 317 #endif /* PTS_LINUX */ 318 case TIOCSETAF: 319 case TIOCSETAW: 320 /* 321 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 322 * TCSADRAIN into something different. If an application would 323 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 324 * deadlock waiting for all data to be read. 325 */ 326 cmd = TIOCSETA; 327 break; 328 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 329 case TIOCGPTN: 330 /* 331 * Get the device unit number. 332 */ 333 if (psc->pts_unit < 0) 334 return (ENOTTY); 335 *(unsigned int *)data = psc->pts_unit; 336 return (0); 337 #endif /* PTS_COMPAT || PTS_LINUX */ 338 case TIOCGPGRP: 339 /* Get the foreground process group ID. */ 340 tty_lock(tp); 341 if (tp->t_pgrp != NULL) 342 *(int *)data = tp->t_pgrp->pg_id; 343 else 344 *(int *)data = NO_PID; 345 tty_unlock(tp); 346 return (0); 347 case TIOCGSID: 348 /* Get the session leader process ID. */ 349 tty_lock(tp); 350 if (tp->t_session == NULL) 351 error = ENOTTY; 352 else 353 *(int *)data = tp->t_session->s_sid; 354 tty_unlock(tp); 355 return (error); 356 case TIOCPTMASTER: 357 /* Yes, we are a pseudo-terminal master. */ 358 return (0); 359 case TIOCSIG: 360 /* Signal the foreground process group. */ 361 sig = *(int *)data; 362 if (sig < 1 || sig >= NSIG) 363 return (EINVAL); 364 365 tty_lock(tp); 366 tty_signal_pgrp(tp, sig); 367 tty_unlock(tp); 368 return (0); 369 case TIOCPKT: 370 /* Enable/disable packet mode. */ 371 tty_lock(tp); 372 if (*(int *)data) 373 psc->pts_flags |= PTS_PKT; 374 else 375 psc->pts_flags &= ~PTS_PKT; 376 tty_unlock(tp); 377 return (0); 378 } 379 380 /* Just redirect this ioctl to the slave device. */ 381 tty_lock(tp); 382 error = tty_ioctl(tp, cmd, data, td); 383 tty_unlock(tp); 384 if (error == ENOIOCTL) 385 error = ENOTTY; 386 387 return (error); 388 } 389 390 static int 391 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 392 struct thread *td) 393 { 394 struct tty *tp = fp->f_data; 395 struct pts_softc *psc = tty_softc(tp); 396 int revents = 0; 397 398 tty_lock(tp); 399 400 if (psc->pts_flags & PTS_FINISHED) { 401 /* Slave device is not opened. */ 402 tty_unlock(tp); 403 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP); 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 #ifndef PTS_EXTERNAL 698 static 699 #endif /* !PTS_EXTERNAL */ 700 int 701 pts_alloc(int fflags, struct thread *td, struct file *fp) 702 { 703 int unit, ok; 704 struct tty *tp; 705 struct pts_softc *psc; 706 struct proc *p = td->td_proc; 707 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 708 709 /* Resource limiting. */ 710 PROC_LOCK(p); 711 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 712 PROC_UNLOCK(p); 713 if (!ok) 714 return (EAGAIN); 715 716 /* Try to allocate a new pts unit number. */ 717 unit = alloc_unr(pts_pool); 718 if (unit < 0) { 719 chgptscnt(uid, -1, 0); 720 return (EAGAIN); 721 } 722 if (unit > pts_maxdev) { 723 free_unr(pts_pool, unit); 724 chgptscnt(uid, -1, 0); 725 return (EAGAIN); 726 } 727 728 /* Allocate TTY and softc. */ 729 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 730 cv_init(&psc->pts_inwait, "pts inwait"); 731 cv_init(&psc->pts_outwait, "pts outwait"); 732 733 psc->pts_unit = unit; 734 psc->pts_uidinfo = uid; 735 uihold(uid); 736 737 tp = tty_alloc(&pts_class, psc); 738 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 739 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 740 741 /* Expose the slave device as well. */ 742 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 743 744 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 745 746 return (0); 747 } 748 749 #ifdef PTS_EXTERNAL 750 int 751 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 752 struct cdev *dev, const char *name) 753 { 754 int ok; 755 struct tty *tp; 756 struct pts_softc *psc; 757 struct proc *p = td->td_proc; 758 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 759 760 /* Resource limiting. */ 761 PROC_LOCK(p); 762 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 763 PROC_UNLOCK(p); 764 if (!ok) 765 return (EAGAIN); 766 767 /* Allocate TTY and softc. */ 768 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 769 cv_init(&psc->pts_inwait, "pts inwait"); 770 cv_init(&psc->pts_outwait, "pts outwait"); 771 772 psc->pts_unit = -1; 773 psc->pts_cdev = dev; 774 psc->pts_uidinfo = uid; 775 uihold(uid); 776 777 tp = tty_alloc(&pts_class, psc); 778 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 779 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 780 781 /* Expose the slave device as well. */ 782 tty_makedev(tp, td->td_ucred, "%s", name); 783 784 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 785 786 return (0); 787 } 788 #endif /* PTS_EXTERNAL */ 789 790 int 791 posix_openpt(struct thread *td, struct posix_openpt_args *uap) 792 { 793 int error, fd; 794 struct file *fp; 795 796 /* 797 * POSIX states it's unspecified when other flags are passed. We 798 * don't allow this. 799 */ 800 if (uap->flags & ~(O_RDWR|O_NOCTTY)) 801 return (EINVAL); 802 803 error = falloc(td, &fp, &fd); 804 if (error) 805 return (error); 806 807 /* Allocate the actual pseudo-TTY. */ 808 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 809 if (error != 0) { 810 fdclose(td->td_proc->p_fd, fp, fd, td); 811 return (error); 812 } 813 814 /* Pass it back to userspace. */ 815 td->td_retval[0] = fd; 816 fdrop(fp, td); 817 818 return (0); 819 } 820 821 static void 822 pts_init(void *unused) 823 { 824 825 pts_pool = new_unrhdr(0, INT_MAX, NULL); 826 } 827 828 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 829