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