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 /* 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/mutex.h> 52 #include <sys/poll.h> 53 #include <sys/proc.h> 54 #include <sys/racct.h> 55 #include <sys/resourcevar.h> 56 #include <sys/serial.h> 57 #include <sys/stat.h> 58 #include <sys/syscall.h> 59 #include <sys/syscallsubr.h> 60 #include <sys/sysctl.h> 61 #include <sys/sysproto.h> 62 #include <sys/systm.h> 63 #include <sys/tty.h> 64 #include <sys/ttycom.h> 65 #include <sys/uio.h> 66 #include <sys/user.h> 67 68 #include <machine/stdarg.h> 69 70 /* 71 * Our utmp(5) format is limited to 8-byte TTY line names. This means 72 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow 73 * users to increase this number, assuming they have manually increased 74 * UT_LINESIZE. 75 */ 76 static struct unrhdr *pts_pool; 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 ucred *pts_cred; /* (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 * occurred (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_ioctl(struct file *fp, u_long cmd, void *data, 259 struct ucred *active_cred, struct thread *td) 260 { 261 struct tty *tp = fp->f_data; 262 struct pts_softc *psc = tty_softc(tp); 263 int error = 0, sig; 264 265 switch (cmd) { 266 case FIODTYPE: 267 *(int *)data = D_TTY; 268 return (0); 269 case FIONBIO: 270 /* This device supports non-blocking operation. */ 271 return (0); 272 case FIONREAD: 273 tty_lock(tp); 274 if (psc->pts_flags & PTS_FINISHED) { 275 /* Force read() to be called. */ 276 *(int *)data = 1; 277 } else { 278 *(int *)data = ttydisc_getc_poll(tp); 279 } 280 tty_unlock(tp); 281 return (0); 282 case FIODGNAME: 283 #ifdef COMPAT_FREEBSD32 284 case FIODGNAME_32: 285 #endif 286 { 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, fiodgname_buf_get_ptr(fgn, cmd), 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, fp->f_flag, 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 & (POLLIN|POLLRDNORM)) | POLLHUP); 403 } 404 405 if (events & (POLLIN|POLLRDNORM)) { 406 /* See if we can getc something. */ 407 if (ttydisc_getc_poll(tp) || 408 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 409 revents |= events & (POLLIN|POLLRDNORM); 410 } 411 if (events & (POLLOUT|POLLWRNORM)) { 412 /* See if we can rint something. */ 413 if (ttydisc_rint_poll(tp)) 414 revents |= events & (POLLOUT|POLLWRNORM); 415 } 416 417 /* 418 * No need to check for POLLHUP here. This device cannot be used 419 * as a callout device, which means we always have a carrier, 420 * because the master is. 421 */ 422 423 if (revents == 0) { 424 /* 425 * This code might look misleading, but the naming of 426 * poll events on this side is the opposite of the slave 427 * device. 428 */ 429 if (events & (POLLIN|POLLRDNORM)) 430 selrecord(td, &psc->pts_outpoll); 431 if (events & (POLLOUT|POLLWRNORM)) 432 selrecord(td, &psc->pts_inpoll); 433 } 434 435 tty_unlock(tp); 436 437 return (revents); 438 } 439 440 /* 441 * kqueue support. 442 */ 443 444 static void 445 pts_kqops_read_detach(struct knote *kn) 446 { 447 struct file *fp = kn->kn_fp; 448 struct tty *tp = fp->f_data; 449 struct pts_softc *psc = tty_softc(tp); 450 451 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 452 } 453 454 static int 455 pts_kqops_read_event(struct knote *kn, long hint) 456 { 457 struct file *fp = kn->kn_fp; 458 struct tty *tp = fp->f_data; 459 struct pts_softc *psc = tty_softc(tp); 460 461 if (psc->pts_flags & PTS_FINISHED) { 462 kn->kn_flags |= EV_EOF; 463 return (1); 464 } else { 465 kn->kn_data = ttydisc_getc_poll(tp); 466 return (kn->kn_data > 0); 467 } 468 } 469 470 static void 471 pts_kqops_write_detach(struct knote *kn) 472 { 473 struct file *fp = kn->kn_fp; 474 struct tty *tp = fp->f_data; 475 struct pts_softc *psc = tty_softc(tp); 476 477 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 478 } 479 480 static int 481 pts_kqops_write_event(struct knote *kn, long hint) 482 { 483 struct file *fp = kn->kn_fp; 484 struct tty *tp = fp->f_data; 485 struct pts_softc *psc = tty_softc(tp); 486 487 if (psc->pts_flags & PTS_FINISHED) { 488 kn->kn_flags |= EV_EOF; 489 return (1); 490 } else { 491 kn->kn_data = ttydisc_rint_poll(tp); 492 return (kn->kn_data > 0); 493 } 494 } 495 496 static struct filterops pts_kqops_read = { 497 .f_isfd = 1, 498 .f_detach = pts_kqops_read_detach, 499 .f_event = pts_kqops_read_event, 500 }; 501 static struct filterops pts_kqops_write = { 502 .f_isfd = 1, 503 .f_detach = pts_kqops_write_detach, 504 .f_event = pts_kqops_write_event, 505 }; 506 507 static int 508 ptsdev_kqfilter(struct file *fp, struct knote *kn) 509 { 510 struct tty *tp = fp->f_data; 511 struct pts_softc *psc = tty_softc(tp); 512 int error = 0; 513 514 tty_lock(tp); 515 516 switch (kn->kn_filter) { 517 case EVFILT_READ: 518 kn->kn_fop = &pts_kqops_read; 519 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 520 break; 521 case EVFILT_WRITE: 522 kn->kn_fop = &pts_kqops_write; 523 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 524 break; 525 default: 526 error = EINVAL; 527 break; 528 } 529 530 tty_unlock(tp); 531 return (error); 532 } 533 534 static int 535 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 536 { 537 struct tty *tp = fp->f_data; 538 #ifdef PTS_EXTERNAL 539 struct pts_softc *psc = tty_softc(tp); 540 #endif /* PTS_EXTERNAL */ 541 struct cdev *dev = tp->t_dev; 542 543 /* 544 * According to POSIX, we must implement an fstat(). This also 545 * makes this implementation compatible with Linux binaries, 546 * because Linux calls fstat() on the pseudo-terminal master to 547 * obtain st_rdev. 548 * 549 * XXX: POSIX also mentions we must fill in st_dev, but how? 550 */ 551 552 bzero(sb, sizeof *sb); 553 #ifdef PTS_EXTERNAL 554 if (psc->pts_cdev != NULL) 555 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 556 else 557 #endif /* PTS_EXTERNAL */ 558 sb->st_ino = sb->st_rdev = tty_udev(tp); 559 560 sb->st_atim = dev->si_atime; 561 sb->st_ctim = dev->si_ctime; 562 sb->st_mtim = dev->si_mtime; 563 sb->st_uid = dev->si_uid; 564 sb->st_gid = dev->si_gid; 565 sb->st_mode = dev->si_mode | S_IFCHR; 566 567 return (0); 568 } 569 570 static int 571 ptsdev_close(struct file *fp, struct thread *td) 572 { 573 struct tty *tp = fp->f_data; 574 575 /* Deallocate TTY device. */ 576 tty_lock(tp); 577 tty_rel_gone(tp); 578 579 /* 580 * Open of /dev/ptmx or /dev/ptyXX changes the type of file 581 * from DTYPE_VNODE to DTYPE_PTS. vn_open() increases vnode 582 * use count, we need to decrement it, and possibly do other 583 * required cleanup. 584 */ 585 if (fp->f_vnode != NULL) 586 return (vnops.fo_close(fp, td)); 587 588 return (0); 589 } 590 591 static int 592 ptsdev_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 593 { 594 struct tty *tp; 595 596 kif->kf_type = KF_TYPE_PTS; 597 tp = fp->f_data; 598 kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp); 599 kif->kf_un.kf_pts.kf_pts_dev_freebsd11 = 600 kif->kf_un.kf_pts.kf_pts_dev; /* truncate */ 601 strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path)); 602 return (0); 603 } 604 605 static struct fileops ptsdev_ops = { 606 .fo_read = ptsdev_read, 607 .fo_write = ptsdev_write, 608 .fo_truncate = invfo_truncate, 609 .fo_ioctl = ptsdev_ioctl, 610 .fo_poll = ptsdev_poll, 611 .fo_kqfilter = ptsdev_kqfilter, 612 .fo_stat = ptsdev_stat, 613 .fo_close = ptsdev_close, 614 .fo_chmod = invfo_chmod, 615 .fo_chown = invfo_chown, 616 .fo_sendfile = invfo_sendfile, 617 .fo_fill_kinfo = ptsdev_fill_kinfo, 618 .fo_flags = DFLAG_PASSABLE, 619 }; 620 621 /* 622 * Driver-side hooks. 623 */ 624 625 static void 626 ptsdrv_outwakeup(struct tty *tp) 627 { 628 struct pts_softc *psc = tty_softc(tp); 629 630 cv_broadcast(&psc->pts_outwait); 631 selwakeup(&psc->pts_outpoll); 632 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 633 } 634 635 static void 636 ptsdrv_inwakeup(struct tty *tp) 637 { 638 struct pts_softc *psc = tty_softc(tp); 639 640 cv_broadcast(&psc->pts_inwait); 641 selwakeup(&psc->pts_inpoll); 642 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 643 } 644 645 static int 646 ptsdrv_open(struct tty *tp) 647 { 648 struct pts_softc *psc = tty_softc(tp); 649 650 psc->pts_flags &= ~PTS_FINISHED; 651 652 return (0); 653 } 654 655 static void 656 ptsdrv_close(struct tty *tp) 657 { 658 struct pts_softc *psc = tty_softc(tp); 659 660 /* Wake up any blocked readers/writers. */ 661 psc->pts_flags |= PTS_FINISHED; 662 ptsdrv_outwakeup(tp); 663 ptsdrv_inwakeup(tp); 664 } 665 666 static void 667 ptsdrv_pktnotify(struct tty *tp, char event) 668 { 669 struct pts_softc *psc = tty_softc(tp); 670 671 /* 672 * Clear conflicting flags. 673 */ 674 675 switch (event) { 676 case TIOCPKT_STOP: 677 psc->pts_pkt &= ~TIOCPKT_START; 678 break; 679 case TIOCPKT_START: 680 psc->pts_pkt &= ~TIOCPKT_STOP; 681 break; 682 case TIOCPKT_NOSTOP: 683 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 684 break; 685 case TIOCPKT_DOSTOP: 686 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 687 break; 688 } 689 690 psc->pts_pkt |= event; 691 ptsdrv_outwakeup(tp); 692 } 693 694 static void 695 ptsdrv_free(void *softc) 696 { 697 struct pts_softc *psc = softc; 698 699 /* Make device number available again. */ 700 if (psc->pts_unit >= 0) 701 free_unr(pts_pool, psc->pts_unit); 702 703 chgptscnt(psc->pts_cred->cr_ruidinfo, -1, 0); 704 racct_sub_cred(psc->pts_cred, RACCT_NPTS, 1); 705 crfree(psc->pts_cred); 706 707 seldrain(&psc->pts_inpoll); 708 seldrain(&psc->pts_outpoll); 709 knlist_destroy(&psc->pts_inpoll.si_note); 710 knlist_destroy(&psc->pts_outpoll.si_note); 711 712 #ifdef PTS_EXTERNAL 713 /* Destroy master device as well. */ 714 if (psc->pts_cdev != NULL) 715 destroy_dev_sched(psc->pts_cdev); 716 #endif /* PTS_EXTERNAL */ 717 718 free(psc, M_PTS); 719 } 720 721 static struct ttydevsw pts_class = { 722 .tsw_flags = TF_NOPREFIX, 723 .tsw_outwakeup = ptsdrv_outwakeup, 724 .tsw_inwakeup = ptsdrv_inwakeup, 725 .tsw_open = ptsdrv_open, 726 .tsw_close = ptsdrv_close, 727 .tsw_pktnotify = ptsdrv_pktnotify, 728 .tsw_free = ptsdrv_free, 729 }; 730 731 #ifndef PTS_EXTERNAL 732 static 733 #endif /* !PTS_EXTERNAL */ 734 int 735 pts_alloc(int fflags, struct thread *td, struct file *fp) 736 { 737 int unit, ok, error; 738 struct tty *tp; 739 struct pts_softc *psc; 740 struct proc *p = td->td_proc; 741 struct ucred *cred = td->td_ucred; 742 743 /* Resource limiting. */ 744 PROC_LOCK(p); 745 error = racct_add(p, RACCT_NPTS, 1); 746 if (error != 0) { 747 PROC_UNLOCK(p); 748 return (EAGAIN); 749 } 750 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 751 if (!ok) { 752 racct_sub(p, RACCT_NPTS, 1); 753 PROC_UNLOCK(p); 754 return (EAGAIN); 755 } 756 PROC_UNLOCK(p); 757 758 /* Try to allocate a new pts unit number. */ 759 unit = alloc_unr(pts_pool); 760 if (unit < 0) { 761 racct_sub(p, RACCT_NPTS, 1); 762 chgptscnt(cred->cr_ruidinfo, -1, 0); 763 return (EAGAIN); 764 } 765 766 /* Allocate TTY and softc. */ 767 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 768 cv_init(&psc->pts_inwait, "ptsin"); 769 cv_init(&psc->pts_outwait, "ptsout"); 770 771 psc->pts_unit = unit; 772 psc->pts_cred = crhold(cred); 773 774 tp = tty_alloc(&pts_class, psc); 775 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 776 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 777 778 /* Expose the slave device as well. */ 779 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 780 781 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 782 783 return (0); 784 } 785 786 #ifdef PTS_EXTERNAL 787 int 788 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 789 struct cdev *dev, const char *name) 790 { 791 int ok, error; 792 struct tty *tp; 793 struct pts_softc *psc; 794 struct proc *p = td->td_proc; 795 struct ucred *cred = td->td_ucred; 796 797 /* Resource limiting. */ 798 PROC_LOCK(p); 799 error = racct_add(p, RACCT_NPTS, 1); 800 if (error != 0) { 801 PROC_UNLOCK(p); 802 return (EAGAIN); 803 } 804 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPTS)); 805 if (!ok) { 806 racct_sub(p, RACCT_NPTS, 1); 807 PROC_UNLOCK(p); 808 return (EAGAIN); 809 } 810 PROC_UNLOCK(p); 811 812 /* Allocate TTY and softc. */ 813 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 814 cv_init(&psc->pts_inwait, "ptsin"); 815 cv_init(&psc->pts_outwait, "ptsout"); 816 817 psc->pts_unit = -1; 818 psc->pts_cdev = dev; 819 psc->pts_cred = crhold(cred); 820 821 tp = tty_alloc(&pts_class, psc); 822 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 823 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 824 825 /* Expose the slave device as well. */ 826 tty_makedev(tp, td->td_ucred, "%s", name); 827 828 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 829 830 return (0); 831 } 832 #endif /* PTS_EXTERNAL */ 833 834 int 835 sys_posix_openpt(struct thread *td, struct posix_openpt_args *uap) 836 { 837 int error, fd; 838 struct file *fp; 839 840 /* 841 * POSIX states it's unspecified when other flags are passed. We 842 * don't allow this. 843 */ 844 if (uap->flags & ~(O_RDWR|O_NOCTTY|O_CLOEXEC)) 845 return (EINVAL); 846 847 error = falloc(td, &fp, &fd, uap->flags); 848 if (error) 849 return (error); 850 851 /* Allocate the actual pseudo-TTY. */ 852 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 853 if (error != 0) { 854 fdclose(td, fp, fd); 855 fdrop(fp, td); 856 return (error); 857 } 858 859 /* Pass it back to userspace. */ 860 td->td_retval[0] = fd; 861 fdrop(fp, td); 862 863 return (0); 864 } 865 866 static void 867 pts_init(void *unused) 868 { 869 870 pts_pool = new_unrhdr(0, INT_MAX, NULL); 871 } 872 873 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 874