1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/mutex.h> 54 #include <sys/poll.h> 55 #include <sys/proc.h> 56 #include <sys/racct.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/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 #ifdef COMPAT_FREEBSD32 286 case FIODGNAME_32: 287 #endif 288 { 289 struct fiodgname_arg *fgn; 290 const char *p; 291 int i; 292 293 /* Reverse device name lookups, for ptsname() and ttyname(). */ 294 fgn = data; 295 p = tty_devname(tp); 296 i = strlen(p) + 1; 297 if (i > fgn->len) 298 return (EINVAL); 299 return (copyout(p, fiodgname_buf_get_ptr(fgn, cmd), i)); 300 } 301 302 /* 303 * We need to implement TIOCGPGRP and TIOCGSID here again. When 304 * called on the pseudo-terminal master, it should not check if 305 * the terminal is the foreground terminal of the calling 306 * process. 307 * 308 * TIOCGETA is also implemented here. Various Linux PTY routines 309 * often call isatty(), which is implemented by tcgetattr(). 310 */ 311 #ifdef PTS_LINUX 312 case TIOCGETA: 313 /* Obtain terminal flags through tcgetattr(). */ 314 tty_lock(tp); 315 *(struct termios*)data = tp->t_termios; 316 tty_unlock(tp); 317 return (0); 318 #endif /* PTS_LINUX */ 319 case TIOCSETAF: 320 case TIOCSETAW: 321 /* 322 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 323 * TCSADRAIN into something different. If an application would 324 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 325 * deadlock waiting for all data to be read. 326 */ 327 cmd = TIOCSETA; 328 break; 329 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 330 case TIOCGPTN: 331 /* 332 * Get the device unit number. 333 */ 334 if (psc->pts_unit < 0) 335 return (ENOTTY); 336 *(unsigned int *)data = psc->pts_unit; 337 return (0); 338 #endif /* PTS_COMPAT || PTS_LINUX */ 339 case TIOCGPGRP: 340 /* Get the foreground process group ID. */ 341 tty_lock(tp); 342 if (tp->t_pgrp != NULL) 343 *(int *)data = tp->t_pgrp->pg_id; 344 else 345 *(int *)data = NO_PID; 346 tty_unlock(tp); 347 return (0); 348 case TIOCGSID: 349 /* Get the session leader process ID. */ 350 tty_lock(tp); 351 if (tp->t_session == NULL) 352 error = ENOTTY; 353 else 354 *(int *)data = tp->t_session->s_sid; 355 tty_unlock(tp); 356 return (error); 357 case TIOCPTMASTER: 358 /* Yes, we are a pseudo-terminal master. */ 359 return (0); 360 case TIOCSIG: 361 /* Signal the foreground process group. */ 362 sig = *(int *)data; 363 if (sig < 1 || sig >= NSIG) 364 return (EINVAL); 365 366 tty_lock(tp); 367 tty_signal_pgrp(tp, sig); 368 tty_unlock(tp); 369 return (0); 370 case TIOCPKT: 371 /* Enable/disable packet mode. */ 372 tty_lock(tp); 373 if (*(int *)data) 374 psc->pts_flags |= PTS_PKT; 375 else 376 psc->pts_flags &= ~PTS_PKT; 377 tty_unlock(tp); 378 return (0); 379 } 380 381 /* Just redirect this ioctl to the slave device. */ 382 tty_lock(tp); 383 error = tty_ioctl(tp, cmd, data, fp->f_flag, td); 384 tty_unlock(tp); 385 if (error == ENOIOCTL) 386 error = ENOTTY; 387 388 return (error); 389 } 390 391 static int 392 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 393 struct thread *td) 394 { 395 struct tty *tp = fp->f_data; 396 struct pts_softc *psc = tty_softc(tp); 397 int revents = 0; 398 399 tty_lock(tp); 400 401 if (psc->pts_flags & PTS_FINISHED) { 402 /* Slave device is not opened. */ 403 tty_unlock(tp); 404 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP); 405 } 406 407 if (events & (POLLIN|POLLRDNORM)) { 408 /* See if we can getc something. */ 409 if (ttydisc_getc_poll(tp) || 410 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 411 revents |= events & (POLLIN|POLLRDNORM); 412 } 413 if (events & (POLLOUT|POLLWRNORM)) { 414 /* See if we can rint something. */ 415 if (ttydisc_rint_poll(tp)) 416 revents |= events & (POLLOUT|POLLWRNORM); 417 } 418 419 /* 420 * No need to check for POLLHUP here. This device cannot be used 421 * as a callout device, which means we always have a carrier, 422 * because the master is. 423 */ 424 425 if (revents == 0) { 426 /* 427 * This code might look misleading, but the naming of 428 * poll events on this side is the opposite of the slave 429 * device. 430 */ 431 if (events & (POLLIN|POLLRDNORM)) 432 selrecord(td, &psc->pts_outpoll); 433 if (events & (POLLOUT|POLLWRNORM)) 434 selrecord(td, &psc->pts_inpoll); 435 } 436 437 tty_unlock(tp); 438 439 return (revents); 440 } 441 442 /* 443 * kqueue support. 444 */ 445 446 static void 447 pts_kqops_read_detach(struct knote *kn) 448 { 449 struct file *fp = kn->kn_fp; 450 struct tty *tp = fp->f_data; 451 struct pts_softc *psc = tty_softc(tp); 452 453 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 454 } 455 456 static int 457 pts_kqops_read_event(struct knote *kn, long hint) 458 { 459 struct file *fp = kn->kn_fp; 460 struct tty *tp = fp->f_data; 461 struct pts_softc *psc = tty_softc(tp); 462 463 if (psc->pts_flags & PTS_FINISHED) { 464 kn->kn_flags |= EV_EOF; 465 return (1); 466 } else { 467 kn->kn_data = ttydisc_getc_poll(tp); 468 return (kn->kn_data > 0); 469 } 470 } 471 472 static void 473 pts_kqops_write_detach(struct knote *kn) 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 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 480 } 481 482 static int 483 pts_kqops_write_event(struct knote *kn, long hint) 484 { 485 struct file *fp = kn->kn_fp; 486 struct tty *tp = fp->f_data; 487 struct pts_softc *psc = tty_softc(tp); 488 489 if (psc->pts_flags & PTS_FINISHED) { 490 kn->kn_flags |= EV_EOF; 491 return (1); 492 } else { 493 kn->kn_data = ttydisc_rint_poll(tp); 494 return (kn->kn_data > 0); 495 } 496 } 497 498 static struct filterops pts_kqops_read = { 499 .f_isfd = 1, 500 .f_detach = pts_kqops_read_detach, 501 .f_event = pts_kqops_read_event, 502 }; 503 static struct filterops pts_kqops_write = { 504 .f_isfd = 1, 505 .f_detach = pts_kqops_write_detach, 506 .f_event = pts_kqops_write_event, 507 }; 508 509 static int 510 ptsdev_kqfilter(struct file *fp, struct knote *kn) 511 { 512 struct tty *tp = fp->f_data; 513 struct pts_softc *psc = tty_softc(tp); 514 int error = 0; 515 516 tty_lock(tp); 517 518 switch (kn->kn_filter) { 519 case EVFILT_READ: 520 kn->kn_fop = &pts_kqops_read; 521 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 522 break; 523 case EVFILT_WRITE: 524 kn->kn_fop = &pts_kqops_write; 525 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 526 break; 527 default: 528 error = EINVAL; 529 break; 530 } 531 532 tty_unlock(tp); 533 return (error); 534 } 535 536 static int 537 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 538 { 539 struct tty *tp = fp->f_data; 540 #ifdef PTS_EXTERNAL 541 struct pts_softc *psc = tty_softc(tp); 542 #endif /* PTS_EXTERNAL */ 543 struct cdev *dev = tp->t_dev; 544 545 /* 546 * According to POSIX, we must implement an fstat(). This also 547 * makes this implementation compatible with Linux binaries, 548 * because Linux calls fstat() on the pseudo-terminal master to 549 * obtain st_rdev. 550 * 551 * XXX: POSIX also mentions we must fill in st_dev, but how? 552 */ 553 554 bzero(sb, sizeof *sb); 555 #ifdef PTS_EXTERNAL 556 if (psc->pts_cdev != NULL) 557 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 558 else 559 #endif /* PTS_EXTERNAL */ 560 sb->st_ino = sb->st_rdev = tty_udev(tp); 561 562 sb->st_atim = dev->si_atime; 563 sb->st_ctim = dev->si_ctime; 564 sb->st_mtim = dev->si_mtime; 565 sb->st_uid = dev->si_uid; 566 sb->st_gid = dev->si_gid; 567 sb->st_mode = dev->si_mode | S_IFCHR; 568 569 return (0); 570 } 571 572 static int 573 ptsdev_close(struct file *fp, struct thread *td) 574 { 575 struct tty *tp = fp->f_data; 576 577 /* Deallocate TTY device. */ 578 tty_lock(tp); 579 tty_rel_gone(tp); 580 581 /* 582 * Open of /dev/ptmx or /dev/ptyXX changes the type of file 583 * from DTYPE_VNODE to DTYPE_PTS. vn_open() increases vnode 584 * use count, we need to decrement it, and possibly do other 585 * required cleanup. 586 */ 587 if (fp->f_vnode != NULL) 588 return (vnops.fo_close(fp, td)); 589 590 return (0); 591 } 592 593 static int 594 ptsdev_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 595 { 596 struct tty *tp; 597 598 kif->kf_type = KF_TYPE_PTS; 599 tp = fp->f_data; 600 kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp); 601 kif->kf_un.kf_pts.kf_pts_dev_freebsd11 = 602 kif->kf_un.kf_pts.kf_pts_dev; /* truncate */ 603 strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path)); 604 return (0); 605 } 606 607 static struct fileops ptsdev_ops = { 608 .fo_read = ptsdev_read, 609 .fo_write = ptsdev_write, 610 .fo_truncate = invfo_truncate, 611 .fo_ioctl = ptsdev_ioctl, 612 .fo_poll = ptsdev_poll, 613 .fo_kqfilter = ptsdev_kqfilter, 614 .fo_stat = ptsdev_stat, 615 .fo_close = ptsdev_close, 616 .fo_chmod = invfo_chmod, 617 .fo_chown = invfo_chown, 618 .fo_sendfile = invfo_sendfile, 619 .fo_fill_kinfo = ptsdev_fill_kinfo, 620 .fo_flags = DFLAG_PASSABLE, 621 }; 622 623 /* 624 * Driver-side hooks. 625 */ 626 627 static void 628 ptsdrv_outwakeup(struct tty *tp) 629 { 630 struct pts_softc *psc = tty_softc(tp); 631 632 cv_broadcast(&psc->pts_outwait); 633 selwakeup(&psc->pts_outpoll); 634 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 635 } 636 637 static void 638 ptsdrv_inwakeup(struct tty *tp) 639 { 640 struct pts_softc *psc = tty_softc(tp); 641 642 cv_broadcast(&psc->pts_inwait); 643 selwakeup(&psc->pts_inpoll); 644 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 645 } 646 647 static int 648 ptsdrv_open(struct tty *tp) 649 { 650 struct pts_softc *psc = tty_softc(tp); 651 652 psc->pts_flags &= ~PTS_FINISHED; 653 654 return (0); 655 } 656 657 static void 658 ptsdrv_close(struct tty *tp) 659 { 660 struct pts_softc *psc = tty_softc(tp); 661 662 /* Wake up any blocked readers/writers. */ 663 psc->pts_flags |= PTS_FINISHED; 664 ptsdrv_outwakeup(tp); 665 ptsdrv_inwakeup(tp); 666 } 667 668 static void 669 ptsdrv_pktnotify(struct tty *tp, char event) 670 { 671 struct pts_softc *psc = tty_softc(tp); 672 673 /* 674 * Clear conflicting flags. 675 */ 676 677 switch (event) { 678 case TIOCPKT_STOP: 679 psc->pts_pkt &= ~TIOCPKT_START; 680 break; 681 case TIOCPKT_START: 682 psc->pts_pkt &= ~TIOCPKT_STOP; 683 break; 684 case TIOCPKT_NOSTOP: 685 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 686 break; 687 case TIOCPKT_DOSTOP: 688 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 689 break; 690 } 691 692 psc->pts_pkt |= event; 693 ptsdrv_outwakeup(tp); 694 } 695 696 static void 697 ptsdrv_free(void *softc) 698 { 699 struct pts_softc *psc = softc; 700 701 /* Make device number available again. */ 702 if (psc->pts_unit >= 0) 703 free_unr(pts_pool, psc->pts_unit); 704 705 chgptscnt(psc->pts_cred->cr_ruidinfo, -1, 0); 706 racct_sub_cred(psc->pts_cred, RACCT_NPTS, 1); 707 crfree(psc->pts_cred); 708 709 seldrain(&psc->pts_inpoll); 710 seldrain(&psc->pts_outpoll); 711 knlist_destroy(&psc->pts_inpoll.si_note); 712 knlist_destroy(&psc->pts_outpoll.si_note); 713 714 #ifdef PTS_EXTERNAL 715 /* Destroy master device as well. */ 716 if (psc->pts_cdev != NULL) 717 destroy_dev_sched(psc->pts_cdev); 718 #endif /* PTS_EXTERNAL */ 719 720 free(psc, M_PTS); 721 } 722 723 static struct ttydevsw pts_class = { 724 .tsw_flags = TF_NOPREFIX, 725 .tsw_outwakeup = ptsdrv_outwakeup, 726 .tsw_inwakeup = ptsdrv_inwakeup, 727 .tsw_open = ptsdrv_open, 728 .tsw_close = ptsdrv_close, 729 .tsw_pktnotify = ptsdrv_pktnotify, 730 .tsw_free = ptsdrv_free, 731 }; 732 733 #ifndef PTS_EXTERNAL 734 static 735 #endif /* !PTS_EXTERNAL */ 736 int 737 pts_alloc(int fflags, struct thread *td, struct file *fp) 738 { 739 int unit, ok, error; 740 struct tty *tp; 741 struct pts_softc *psc; 742 struct proc *p = td->td_proc; 743 struct ucred *cred = td->td_ucred; 744 745 /* Resource limiting. */ 746 PROC_LOCK(p); 747 error = racct_add(p, RACCT_NPTS, 1); 748 if (error != 0) { 749 PROC_UNLOCK(p); 750 return (EAGAIN); 751 } 752 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 753 if (!ok) { 754 racct_sub(p, RACCT_NPTS, 1); 755 PROC_UNLOCK(p); 756 return (EAGAIN); 757 } 758 PROC_UNLOCK(p); 759 760 /* Try to allocate a new pts unit number. */ 761 unit = alloc_unr(pts_pool); 762 if (unit < 0) { 763 racct_sub(p, RACCT_NPTS, 1); 764 chgptscnt(cred->cr_ruidinfo, -1, 0); 765 return (EAGAIN); 766 } 767 768 /* Allocate TTY and softc. */ 769 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 770 cv_init(&psc->pts_inwait, "ptsin"); 771 cv_init(&psc->pts_outwait, "ptsout"); 772 773 psc->pts_unit = unit; 774 psc->pts_cred = crhold(cred); 775 776 tp = tty_alloc(&pts_class, psc); 777 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 778 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 779 780 /* Expose the slave device as well. */ 781 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 782 783 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 784 785 return (0); 786 } 787 788 #ifdef PTS_EXTERNAL 789 int 790 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 791 struct cdev *dev, const char *name) 792 { 793 int ok, error; 794 struct tty *tp; 795 struct pts_softc *psc; 796 struct proc *p = td->td_proc; 797 struct ucred *cred = td->td_ucred; 798 799 /* Resource limiting. */ 800 PROC_LOCK(p); 801 error = racct_add(p, RACCT_NPTS, 1); 802 if (error != 0) { 803 PROC_UNLOCK(p); 804 return (EAGAIN); 805 } 806 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 807 if (!ok) { 808 racct_sub(p, RACCT_NPTS, 1); 809 PROC_UNLOCK(p); 810 return (EAGAIN); 811 } 812 PROC_UNLOCK(p); 813 814 /* Allocate TTY and softc. */ 815 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 816 cv_init(&psc->pts_inwait, "ptsin"); 817 cv_init(&psc->pts_outwait, "ptsout"); 818 819 psc->pts_unit = -1; 820 psc->pts_cdev = dev; 821 psc->pts_cred = crhold(cred); 822 823 tp = tty_alloc(&pts_class, psc); 824 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 825 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 826 827 /* Expose the slave device as well. */ 828 tty_makedev(tp, td->td_ucred, "%s", name); 829 830 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 831 832 return (0); 833 } 834 #endif /* PTS_EXTERNAL */ 835 836 int 837 sys_posix_openpt(struct thread *td, struct posix_openpt_args *uap) 838 { 839 int error, fd; 840 struct file *fp; 841 842 /* 843 * POSIX states it's unspecified when other flags are passed. We 844 * don't allow this. 845 */ 846 if (uap->flags & ~(O_RDWR|O_NOCTTY|O_CLOEXEC)) 847 return (EINVAL); 848 849 error = falloc(td, &fp, &fd, uap->flags); 850 if (error) 851 return (error); 852 853 /* Allocate the actual pseudo-TTY. */ 854 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 855 if (error != 0) { 856 fdclose(td, fp, fd); 857 fdrop(fp, td); 858 return (error); 859 } 860 861 /* Pass it back to userspace. */ 862 td->td_retval[0] = fd; 863 fdrop(fp, td); 864 865 return (0); 866 } 867 868 static void 869 pts_init(void *unused) 870 { 871 872 pts_pool = new_unrhdr(0, INT_MAX, NULL); 873 } 874 875 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 876