1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Portions of this software were developed under sponsorship from Snow 8 * B.V., the Netherlands. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 /* Add compatibility bits for FreeBSD. */ 36 #define PTS_COMPAT 37 /* Add pty(4) compat bits. */ 38 #define PTS_EXTERNAL 39 /* Add bits to make Linux binaries work. */ 40 #define PTS_LINUX 41 42 #include <sys/param.h> 43 #include <sys/lock.h> 44 #include <sys/condvar.h> 45 #include <sys/conf.h> 46 #include <sys/fcntl.h> 47 #include <sys/file.h> 48 #include <sys/filedesc.h> 49 #include <sys/filio.h> 50 #include <sys/kernel.h> 51 #include <sys/limits.h> 52 #include <sys/malloc.h> 53 #include <sys/poll.h> 54 #include <sys/proc.h> 55 #include <sys/racct.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/sysctl.h> 62 #include <sys/sysent.h> 63 #include <sys/sysproto.h> 64 #include <sys/systm.h> 65 #include <sys/tty.h> 66 #include <sys/ttycom.h> 67 #include <sys/uio.h> 68 #include <sys/user.h> 69 70 #include <machine/stdarg.h> 71 72 /* 73 * Our utmp(5) format is limited to 8-byte TTY line names. This means 74 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow 75 * users to increase this number, assuming they have manually increased 76 * UT_LINESIZE. 77 */ 78 static struct unrhdr *pts_pool; 79 80 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); 81 82 /* 83 * Per-PTS structure. 84 * 85 * List of locks 86 * (t) locked by tty_lock() 87 * (c) const until freeing 88 */ 89 struct pts_softc { 90 int pts_unit; /* (c) Device unit number. */ 91 unsigned int pts_flags; /* (t) Device flags. */ 92 #define PTS_PKT 0x1 /* Packet mode. */ 93 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */ 94 char pts_pkt; /* (t) Unread packet mode data. */ 95 96 struct cv pts_inwait; /* (t) Blocking write() on master. */ 97 struct selinfo pts_inpoll; /* (t) Select queue for write(). */ 98 struct cv pts_outwait; /* (t) Blocking read() on master. */ 99 struct selinfo pts_outpoll; /* (t) Select queue for read(). */ 100 101 #ifdef PTS_EXTERNAL 102 struct cdev *pts_cdev; /* (c) Master device node. */ 103 #endif /* PTS_EXTERNAL */ 104 105 struct ucred *pts_cred; /* (c) Resource limit. */ 106 }; 107 108 /* 109 * Controller-side file operations. 110 */ 111 112 static int 113 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 114 int flags, struct thread *td) 115 { 116 struct tty *tp = fp->f_data; 117 struct pts_softc *psc = tty_softc(tp); 118 int error = 0; 119 char pkt; 120 121 if (uio->uio_resid == 0) 122 return (0); 123 124 tty_lock(tp); 125 126 for (;;) { 127 /* 128 * Implement packet mode. When packet mode is turned on, 129 * the first byte contains a bitmask of events that 130 * occurred (start, stop, flush, window size, etc). 131 */ 132 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) { 133 pkt = psc->pts_pkt; 134 psc->pts_pkt = 0; 135 tty_unlock(tp); 136 137 error = ureadc(pkt, uio); 138 return (error); 139 } 140 141 /* 142 * Transmit regular data. 143 * 144 * XXX: We shouldn't use ttydisc_getc_poll()! Even 145 * though in this implementation, there is likely going 146 * to be data, we should just call ttydisc_getc_uio() 147 * and use its return value to sleep. 148 */ 149 if (ttydisc_getc_poll(tp)) { 150 if (psc->pts_flags & PTS_PKT) { 151 /* 152 * XXX: Small race. Fortunately PTY 153 * consumers aren't multithreaded. 154 */ 155 156 tty_unlock(tp); 157 error = ureadc(TIOCPKT_DATA, uio); 158 if (error) 159 return (error); 160 tty_lock(tp); 161 } 162 163 error = ttydisc_getc_uio(tp, uio); 164 break; 165 } 166 167 /* Maybe the device isn't used anyway. */ 168 if (psc->pts_flags & PTS_FINISHED) 169 break; 170 171 /* Wait for more data. */ 172 if (fp->f_flag & O_NONBLOCK) { 173 error = EWOULDBLOCK; 174 break; 175 } 176 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx); 177 if (error != 0) 178 break; 179 } 180 181 tty_unlock(tp); 182 183 return (error); 184 } 185 186 static int 187 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 188 int flags, struct thread *td) 189 { 190 struct tty *tp = fp->f_data; 191 struct pts_softc *psc = tty_softc(tp); 192 char ib[256], *ibstart; 193 size_t iblen, rintlen; 194 int error = 0; 195 196 if (uio->uio_resid == 0) 197 return (0); 198 199 for (;;) { 200 ibstart = ib; 201 iblen = MIN(uio->uio_resid, sizeof ib); 202 error = uiomove(ib, iblen, uio); 203 204 tty_lock(tp); 205 if (error != 0) { 206 iblen = 0; 207 goto done; 208 } 209 210 /* 211 * When possible, avoid the slow path. rint_bypass() 212 * copies all input to the input queue at once. 213 */ 214 MPASS(iblen > 0); 215 do { 216 rintlen = ttydisc_rint_simple(tp, ibstart, iblen); 217 ibstart += rintlen; 218 iblen -= rintlen; 219 if (iblen == 0) { 220 /* All data written. */ 221 break; 222 } 223 224 /* Maybe the device isn't used anyway. */ 225 if (psc->pts_flags & PTS_FINISHED) { 226 error = EIO; 227 goto done; 228 } 229 230 /* Wait for more data. */ 231 if (fp->f_flag & O_NONBLOCK) { 232 error = EWOULDBLOCK; 233 goto done; 234 } 235 236 /* Wake up users on the slave side. */ 237 ttydisc_rint_done(tp); 238 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx); 239 if (error != 0) 240 goto done; 241 } while (iblen > 0); 242 243 if (uio->uio_resid == 0) 244 break; 245 tty_unlock(tp); 246 } 247 248 done: ttydisc_rint_done(tp); 249 tty_unlock(tp); 250 251 /* 252 * Don't account for the part of the buffer that we couldn't 253 * pass to the TTY. 254 */ 255 uio->uio_resid += iblen; 256 return (error); 257 } 258 259 static int 260 ptsdev_ioctl(struct file *fp, u_long cmd, void *data, 261 struct ucred *active_cred, struct thread *td) 262 { 263 struct tty *tp = fp->f_data; 264 struct pts_softc *psc = tty_softc(tp); 265 int error = 0, sig; 266 267 switch (cmd) { 268 case FIODTYPE: 269 *(int *)data = D_TTY; 270 return (0); 271 case FIONBIO: 272 /* This device supports non-blocking operation. */ 273 return (0); 274 case FIONREAD: 275 tty_lock(tp); 276 if (psc->pts_flags & PTS_FINISHED) { 277 /* Force read() to be called. */ 278 *(int *)data = 1; 279 } else { 280 *(int *)data = ttydisc_getc_poll(tp); 281 } 282 tty_unlock(tp); 283 return (0); 284 case FIODGNAME: { 285 struct fiodgname_arg *fgn; 286 const char *p; 287 int i; 288 289 /* Reverse device name lookups, for ptsname() and ttyname(). */ 290 fgn = data; 291 p = tty_devname(tp); 292 i = strlen(p) + 1; 293 if (i > fgn->len) 294 return (EINVAL); 295 return copyout(p, fgn->buf, i); 296 } 297 298 /* 299 * We need to implement TIOCGPGRP and TIOCGSID here again. When 300 * called on the pseudo-terminal master, it should not check if 301 * the terminal is the foreground terminal of the calling 302 * process. 303 * 304 * TIOCGETA is also implemented here. Various Linux PTY routines 305 * often call isatty(), which is implemented by tcgetattr(). 306 */ 307 #ifdef PTS_LINUX 308 case TIOCGETA: 309 /* Obtain terminal flags through tcgetattr(). */ 310 tty_lock(tp); 311 *(struct termios*)data = tp->t_termios; 312 tty_unlock(tp); 313 return (0); 314 #endif /* PTS_LINUX */ 315 case TIOCSETAF: 316 case TIOCSETAW: 317 /* 318 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 319 * TCSADRAIN into something different. If an application would 320 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 321 * deadlock waiting for all data to be read. 322 */ 323 cmd = TIOCSETA; 324 break; 325 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 326 case TIOCGPTN: 327 /* 328 * Get the device unit number. 329 */ 330 if (psc->pts_unit < 0) 331 return (ENOTTY); 332 *(unsigned int *)data = psc->pts_unit; 333 return (0); 334 #endif /* PTS_COMPAT || PTS_LINUX */ 335 case TIOCGPGRP: 336 /* Get the foreground process group ID. */ 337 tty_lock(tp); 338 if (tp->t_pgrp != NULL) 339 *(int *)data = tp->t_pgrp->pg_id; 340 else 341 *(int *)data = NO_PID; 342 tty_unlock(tp); 343 return (0); 344 case TIOCGSID: 345 /* Get the session leader process ID. */ 346 tty_lock(tp); 347 if (tp->t_session == NULL) 348 error = ENOTTY; 349 else 350 *(int *)data = tp->t_session->s_sid; 351 tty_unlock(tp); 352 return (error); 353 case TIOCPTMASTER: 354 /* Yes, we are a pseudo-terminal master. */ 355 return (0); 356 case TIOCSIG: 357 /* Signal the foreground process group. */ 358 sig = *(int *)data; 359 if (sig < 1 || sig >= NSIG) 360 return (EINVAL); 361 362 tty_lock(tp); 363 tty_signal_pgrp(tp, sig); 364 tty_unlock(tp); 365 return (0); 366 case TIOCPKT: 367 /* Enable/disable packet mode. */ 368 tty_lock(tp); 369 if (*(int *)data) 370 psc->pts_flags |= PTS_PKT; 371 else 372 psc->pts_flags &= ~PTS_PKT; 373 tty_unlock(tp); 374 return (0); 375 } 376 377 /* Just redirect this ioctl to the slave device. */ 378 tty_lock(tp); 379 error = tty_ioctl(tp, cmd, data, fp->f_flag, td); 380 tty_unlock(tp); 381 if (error == ENOIOCTL) 382 error = ENOTTY; 383 384 return (error); 385 } 386 387 static int 388 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 389 struct thread *td) 390 { 391 struct tty *tp = fp->f_data; 392 struct pts_softc *psc = tty_softc(tp); 393 int revents = 0; 394 395 tty_lock(tp); 396 397 if (psc->pts_flags & PTS_FINISHED) { 398 /* Slave device is not opened. */ 399 tty_unlock(tp); 400 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP); 401 } 402 403 if (events & (POLLIN|POLLRDNORM)) { 404 /* See if we can getc something. */ 405 if (ttydisc_getc_poll(tp) || 406 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 407 revents |= events & (POLLIN|POLLRDNORM); 408 } 409 if (events & (POLLOUT|POLLWRNORM)) { 410 /* See if we can rint something. */ 411 if (ttydisc_rint_poll(tp)) 412 revents |= events & (POLLOUT|POLLWRNORM); 413 } 414 415 /* 416 * No need to check for POLLHUP here. This device cannot be used 417 * as a callout device, which means we always have a carrier, 418 * because the master is. 419 */ 420 421 if (revents == 0) { 422 /* 423 * This code might look misleading, but the naming of 424 * poll events on this side is the opposite of the slave 425 * device. 426 */ 427 if (events & (POLLIN|POLLRDNORM)) 428 selrecord(td, &psc->pts_outpoll); 429 if (events & (POLLOUT|POLLWRNORM)) 430 selrecord(td, &psc->pts_inpoll); 431 } 432 433 tty_unlock(tp); 434 435 return (revents); 436 } 437 438 /* 439 * kqueue support. 440 */ 441 442 static void 443 pts_kqops_read_detach(struct knote *kn) 444 { 445 struct file *fp = kn->kn_fp; 446 struct tty *tp = fp->f_data; 447 struct pts_softc *psc = tty_softc(tp); 448 449 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 450 } 451 452 static int 453 pts_kqops_read_event(struct knote *kn, long hint) 454 { 455 struct file *fp = kn->kn_fp; 456 struct tty *tp = fp->f_data; 457 struct pts_softc *psc = tty_softc(tp); 458 459 if (psc->pts_flags & PTS_FINISHED) { 460 kn->kn_flags |= EV_EOF; 461 return (1); 462 } else { 463 kn->kn_data = ttydisc_getc_poll(tp); 464 return (kn->kn_data > 0); 465 } 466 } 467 468 static void 469 pts_kqops_write_detach(struct knote *kn) 470 { 471 struct file *fp = kn->kn_fp; 472 struct tty *tp = fp->f_data; 473 struct pts_softc *psc = tty_softc(tp); 474 475 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 476 } 477 478 static int 479 pts_kqops_write_event(struct knote *kn, long hint) 480 { 481 struct file *fp = kn->kn_fp; 482 struct tty *tp = fp->f_data; 483 struct pts_softc *psc = tty_softc(tp); 484 485 if (psc->pts_flags & PTS_FINISHED) { 486 kn->kn_flags |= EV_EOF; 487 return (1); 488 } else { 489 kn->kn_data = ttydisc_rint_poll(tp); 490 return (kn->kn_data > 0); 491 } 492 } 493 494 static struct filterops pts_kqops_read = { 495 .f_isfd = 1, 496 .f_detach = pts_kqops_read_detach, 497 .f_event = pts_kqops_read_event, 498 }; 499 static struct filterops pts_kqops_write = { 500 .f_isfd = 1, 501 .f_detach = pts_kqops_write_detach, 502 .f_event = pts_kqops_write_event, 503 }; 504 505 static int 506 ptsdev_kqfilter(struct file *fp, struct knote *kn) 507 { 508 struct tty *tp = fp->f_data; 509 struct pts_softc *psc = tty_softc(tp); 510 int error = 0; 511 512 tty_lock(tp); 513 514 switch (kn->kn_filter) { 515 case EVFILT_READ: 516 kn->kn_fop = &pts_kqops_read; 517 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 518 break; 519 case EVFILT_WRITE: 520 kn->kn_fop = &pts_kqops_write; 521 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 522 break; 523 default: 524 error = EINVAL; 525 break; 526 } 527 528 tty_unlock(tp); 529 return (error); 530 } 531 532 static int 533 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 534 struct thread *td) 535 { 536 struct tty *tp = fp->f_data; 537 #ifdef PTS_EXTERNAL 538 struct pts_softc *psc = tty_softc(tp); 539 #endif /* PTS_EXTERNAL */ 540 struct cdev *dev = tp->t_dev; 541 542 /* 543 * According to POSIX, we must implement an fstat(). This also 544 * makes this implementation compatible with Linux binaries, 545 * because Linux calls fstat() on the pseudo-terminal master to 546 * obtain st_rdev. 547 * 548 * XXX: POSIX also mentions we must fill in st_dev, but how? 549 */ 550 551 bzero(sb, sizeof *sb); 552 #ifdef PTS_EXTERNAL 553 if (psc->pts_cdev != NULL) 554 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 555 else 556 #endif /* PTS_EXTERNAL */ 557 sb->st_ino = sb->st_rdev = tty_udev(tp); 558 559 sb->st_atim = dev->si_atime; 560 sb->st_ctim = dev->si_ctime; 561 sb->st_mtim = dev->si_mtime; 562 sb->st_uid = dev->si_uid; 563 sb->st_gid = dev->si_gid; 564 sb->st_mode = dev->si_mode | S_IFCHR; 565 566 return (0); 567 } 568 569 static int 570 ptsdev_close(struct file *fp, struct thread *td) 571 { 572 struct tty *tp = fp->f_data; 573 574 /* Deallocate TTY device. */ 575 tty_lock(tp); 576 tty_rel_gone(tp); 577 578 /* 579 * Open of /dev/ptmx or /dev/ptyXX changes the type of file 580 * from DTYPE_VNODE to DTYPE_PTS. vn_open() increases vnode 581 * use count, we need to decrement it, and possibly do other 582 * required cleanup. 583 */ 584 if (fp->f_vnode != NULL) 585 return (vnops.fo_close(fp, td)); 586 587 return (0); 588 } 589 590 static int 591 ptsdev_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 592 { 593 struct tty *tp; 594 595 kif->kf_type = KF_TYPE_PTS; 596 tp = fp->f_data; 597 kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp); 598 kif->kf_un.kf_pts.kf_pts_dev_freebsd11 = 599 kif->kf_un.kf_pts.kf_pts_dev; /* truncate */ 600 strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path)); 601 return (0); 602 } 603 604 static struct fileops ptsdev_ops = { 605 .fo_read = ptsdev_read, 606 .fo_write = ptsdev_write, 607 .fo_truncate = invfo_truncate, 608 .fo_ioctl = ptsdev_ioctl, 609 .fo_poll = ptsdev_poll, 610 .fo_kqfilter = ptsdev_kqfilter, 611 .fo_stat = ptsdev_stat, 612 .fo_close = ptsdev_close, 613 .fo_chmod = invfo_chmod, 614 .fo_chown = invfo_chown, 615 .fo_sendfile = invfo_sendfile, 616 .fo_fill_kinfo = ptsdev_fill_kinfo, 617 .fo_flags = DFLAG_PASSABLE, 618 }; 619 620 /* 621 * Driver-side hooks. 622 */ 623 624 static void 625 ptsdrv_outwakeup(struct tty *tp) 626 { 627 struct pts_softc *psc = tty_softc(tp); 628 629 cv_broadcast(&psc->pts_outwait); 630 selwakeup(&psc->pts_outpoll); 631 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 632 } 633 634 static void 635 ptsdrv_inwakeup(struct tty *tp) 636 { 637 struct pts_softc *psc = tty_softc(tp); 638 639 cv_broadcast(&psc->pts_inwait); 640 selwakeup(&psc->pts_inpoll); 641 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 642 } 643 644 static int 645 ptsdrv_open(struct tty *tp) 646 { 647 struct pts_softc *psc = tty_softc(tp); 648 649 psc->pts_flags &= ~PTS_FINISHED; 650 651 return (0); 652 } 653 654 static void 655 ptsdrv_close(struct tty *tp) 656 { 657 struct pts_softc *psc = tty_softc(tp); 658 659 /* Wake up any blocked readers/writers. */ 660 psc->pts_flags |= PTS_FINISHED; 661 ptsdrv_outwakeup(tp); 662 ptsdrv_inwakeup(tp); 663 } 664 665 static void 666 ptsdrv_pktnotify(struct tty *tp, char event) 667 { 668 struct pts_softc *psc = tty_softc(tp); 669 670 /* 671 * Clear conflicting flags. 672 */ 673 674 switch (event) { 675 case TIOCPKT_STOP: 676 psc->pts_pkt &= ~TIOCPKT_START; 677 break; 678 case TIOCPKT_START: 679 psc->pts_pkt &= ~TIOCPKT_STOP; 680 break; 681 case TIOCPKT_NOSTOP: 682 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 683 break; 684 case TIOCPKT_DOSTOP: 685 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 686 break; 687 } 688 689 psc->pts_pkt |= event; 690 ptsdrv_outwakeup(tp); 691 } 692 693 static void 694 ptsdrv_free(void *softc) 695 { 696 struct pts_softc *psc = softc; 697 698 /* Make device number available again. */ 699 if (psc->pts_unit >= 0) 700 free_unr(pts_pool, psc->pts_unit); 701 702 chgptscnt(psc->pts_cred->cr_ruidinfo, -1, 0); 703 racct_sub_cred(psc->pts_cred, RACCT_NPTS, 1); 704 crfree(psc->pts_cred); 705 706 seldrain(&psc->pts_inpoll); 707 seldrain(&psc->pts_outpoll); 708 knlist_destroy(&psc->pts_inpoll.si_note); 709 knlist_destroy(&psc->pts_outpoll.si_note); 710 711 #ifdef PTS_EXTERNAL 712 /* Destroy master device as well. */ 713 if (psc->pts_cdev != NULL) 714 destroy_dev_sched(psc->pts_cdev); 715 #endif /* PTS_EXTERNAL */ 716 717 free(psc, M_PTS); 718 } 719 720 static struct ttydevsw pts_class = { 721 .tsw_flags = TF_NOPREFIX, 722 .tsw_outwakeup = ptsdrv_outwakeup, 723 .tsw_inwakeup = ptsdrv_inwakeup, 724 .tsw_open = ptsdrv_open, 725 .tsw_close = ptsdrv_close, 726 .tsw_pktnotify = ptsdrv_pktnotify, 727 .tsw_free = ptsdrv_free, 728 }; 729 730 #ifndef PTS_EXTERNAL 731 static 732 #endif /* !PTS_EXTERNAL */ 733 int 734 pts_alloc(int fflags, struct thread *td, struct file *fp) 735 { 736 int unit, ok, error; 737 struct tty *tp; 738 struct pts_softc *psc; 739 struct proc *p = td->td_proc; 740 struct ucred *cred = td->td_ucred; 741 742 /* Resource limiting. */ 743 PROC_LOCK(p); 744 error = racct_add(p, RACCT_NPTS, 1); 745 if (error != 0) { 746 PROC_UNLOCK(p); 747 return (EAGAIN); 748 } 749 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 750 if (!ok) { 751 racct_sub(p, RACCT_NPTS, 1); 752 PROC_UNLOCK(p); 753 return (EAGAIN); 754 } 755 PROC_UNLOCK(p); 756 757 /* Try to allocate a new pts unit number. */ 758 unit = alloc_unr(pts_pool); 759 if (unit < 0) { 760 racct_sub(p, RACCT_NPTS, 1); 761 chgptscnt(cred->cr_ruidinfo, -1, 0); 762 return (EAGAIN); 763 } 764 765 /* Allocate TTY and softc. */ 766 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 767 cv_init(&psc->pts_inwait, "ptsin"); 768 cv_init(&psc->pts_outwait, "ptsout"); 769 770 psc->pts_unit = unit; 771 psc->pts_cred = crhold(cred); 772 773 tp = tty_alloc(&pts_class, psc); 774 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 775 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 776 777 /* Expose the slave device as well. */ 778 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 779 780 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 781 782 return (0); 783 } 784 785 #ifdef PTS_EXTERNAL 786 int 787 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 788 struct cdev *dev, const char *name) 789 { 790 int ok, error; 791 struct tty *tp; 792 struct pts_softc *psc; 793 struct proc *p = td->td_proc; 794 struct ucred *cred = td->td_ucred; 795 796 /* Resource limiting. */ 797 PROC_LOCK(p); 798 error = racct_add(p, RACCT_NPTS, 1); 799 if (error != 0) { 800 PROC_UNLOCK(p); 801 return (EAGAIN); 802 } 803 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 804 if (!ok) { 805 racct_sub(p, RACCT_NPTS, 1); 806 PROC_UNLOCK(p); 807 return (EAGAIN); 808 } 809 PROC_UNLOCK(p); 810 811 /* Allocate TTY and softc. */ 812 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 813 cv_init(&psc->pts_inwait, "ptsin"); 814 cv_init(&psc->pts_outwait, "ptsout"); 815 816 psc->pts_unit = -1; 817 psc->pts_cdev = dev; 818 psc->pts_cred = crhold(cred); 819 820 tp = tty_alloc(&pts_class, psc); 821 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 822 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 823 824 /* Expose the slave device as well. */ 825 tty_makedev(tp, td->td_ucred, "%s", name); 826 827 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 828 829 return (0); 830 } 831 #endif /* PTS_EXTERNAL */ 832 833 int 834 sys_posix_openpt(struct thread *td, struct posix_openpt_args *uap) 835 { 836 int error, fd; 837 struct file *fp; 838 839 /* 840 * POSIX states it's unspecified when other flags are passed. We 841 * don't allow this. 842 */ 843 if (uap->flags & ~(O_RDWR|O_NOCTTY|O_CLOEXEC)) 844 return (EINVAL); 845 846 error = falloc(td, &fp, &fd, uap->flags); 847 if (error) 848 return (error); 849 850 /* Allocate the actual pseudo-TTY. */ 851 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 852 if (error != 0) { 853 fdclose(td, fp, fd); 854 fdrop(fp, td); 855 return (error); 856 } 857 858 /* Pass it back to userspace. */ 859 td->td_retval[0] = fd; 860 fdrop(fp, td); 861 862 return (0); 863 } 864 865 static void 866 pts_init(void *unused) 867 { 868 869 pts_pool = new_unrhdr(0, INT_MAX, NULL); 870 } 871 872 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 873