1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/sysproto.h> 46 #include <sys/filedesc.h> 47 #include <sys/filio.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/proc.h> 51 #include <sys/signalvar.h> 52 #include <sys/socketvar.h> 53 #include <sys/uio.h> 54 #include <sys/kernel.h> 55 #include <sys/ktr.h> 56 #include <sys/limits.h> 57 #include <sys/malloc.h> 58 #include <sys/poll.h> 59 #include <sys/resourcevar.h> 60 #include <sys/selinfo.h> 61 #include <sys/sleepqueue.h> 62 #include <sys/syscallsubr.h> 63 #include <sys/sysctl.h> 64 #include <sys/sysent.h> 65 #include <sys/vnode.h> 66 #include <sys/bio.h> 67 #include <sys/buf.h> 68 #include <sys/condvar.h> 69 #ifdef KTRACE 70 #include <sys/ktrace.h> 71 #endif 72 73 #include <security/audit/audit.h> 74 75 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 76 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 77 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 78 79 static int pollscan(struct thread *, struct pollfd *, u_int); 80 static int pollrescan(struct thread *); 81 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 82 static int selrescan(struct thread *, fd_mask **, fd_mask **); 83 static void selfdalloc(struct thread *, void *); 84 static void selfdfree(struct seltd *, struct selfd *); 85 static int dofileread(struct thread *, int, struct file *, struct uio *, 86 off_t, int); 87 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 88 off_t, int); 89 static void doselwakeup(struct selinfo *, int); 90 static void seltdinit(struct thread *); 91 static int seltdwait(struct thread *, int); 92 static void seltdclear(struct thread *); 93 94 /* 95 * One seltd per-thread allocated on demand as needed. 96 * 97 * t - protected by st_mtx 98 * k - Only accessed by curthread or read-only 99 */ 100 struct seltd { 101 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 102 struct selfd *st_free1; /* (k) free fd for read set. */ 103 struct selfd *st_free2; /* (k) free fd for write set. */ 104 struct mtx st_mtx; /* Protects struct seltd */ 105 struct cv st_wait; /* (t) Wait channel. */ 106 int st_flags; /* (t) SELTD_ flags. */ 107 }; 108 109 #define SELTD_PENDING 0x0001 /* We have pending events. */ 110 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 111 112 /* 113 * One selfd allocated per-thread per-file-descriptor. 114 * f - protected by sf_mtx 115 */ 116 struct selfd { 117 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 118 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 119 struct selinfo *sf_si; /* (f) selinfo when linked. */ 120 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 121 struct seltd *sf_td; /* (k) owning seltd. */ 122 void *sf_cookie; /* (k) fd or pollfd. */ 123 }; 124 125 static uma_zone_t selfd_zone; 126 127 #ifndef _SYS_SYSPROTO_H_ 128 struct read_args { 129 int fd; 130 void *buf; 131 size_t nbyte; 132 }; 133 #endif 134 int 135 read(td, uap) 136 struct thread *td; 137 struct read_args *uap; 138 { 139 struct uio auio; 140 struct iovec aiov; 141 int error; 142 143 if (uap->nbyte > INT_MAX) 144 return (EINVAL); 145 aiov.iov_base = uap->buf; 146 aiov.iov_len = uap->nbyte; 147 auio.uio_iov = &aiov; 148 auio.uio_iovcnt = 1; 149 auio.uio_resid = uap->nbyte; 150 auio.uio_segflg = UIO_USERSPACE; 151 error = kern_readv(td, uap->fd, &auio); 152 return(error); 153 } 154 155 /* 156 * Positioned read system call 157 */ 158 #ifndef _SYS_SYSPROTO_H_ 159 struct pread_args { 160 int fd; 161 void *buf; 162 size_t nbyte; 163 int pad; 164 off_t offset; 165 }; 166 #endif 167 int 168 pread(td, uap) 169 struct thread *td; 170 struct pread_args *uap; 171 { 172 struct uio auio; 173 struct iovec aiov; 174 int error; 175 176 if (uap->nbyte > INT_MAX) 177 return (EINVAL); 178 aiov.iov_base = uap->buf; 179 aiov.iov_len = uap->nbyte; 180 auio.uio_iov = &aiov; 181 auio.uio_iovcnt = 1; 182 auio.uio_resid = uap->nbyte; 183 auio.uio_segflg = UIO_USERSPACE; 184 error = kern_preadv(td, uap->fd, &auio, uap->offset); 185 return(error); 186 } 187 188 int 189 freebsd6_pread(td, uap) 190 struct thread *td; 191 struct freebsd6_pread_args *uap; 192 { 193 struct pread_args oargs; 194 195 oargs.fd = uap->fd; 196 oargs.buf = uap->buf; 197 oargs.nbyte = uap->nbyte; 198 oargs.offset = uap->offset; 199 return (pread(td, &oargs)); 200 } 201 202 /* 203 * Scatter read system call. 204 */ 205 #ifndef _SYS_SYSPROTO_H_ 206 struct readv_args { 207 int fd; 208 struct iovec *iovp; 209 u_int iovcnt; 210 }; 211 #endif 212 int 213 readv(struct thread *td, struct readv_args *uap) 214 { 215 struct uio *auio; 216 int error; 217 218 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 219 if (error) 220 return (error); 221 error = kern_readv(td, uap->fd, auio); 222 free(auio, M_IOV); 223 return (error); 224 } 225 226 int 227 kern_readv(struct thread *td, int fd, struct uio *auio) 228 { 229 struct file *fp; 230 int error; 231 232 error = fget_read(td, fd, &fp); 233 if (error) 234 return (error); 235 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 236 fdrop(fp, td); 237 return (error); 238 } 239 240 /* 241 * Scatter positioned read system call. 242 */ 243 #ifndef _SYS_SYSPROTO_H_ 244 struct preadv_args { 245 int fd; 246 struct iovec *iovp; 247 u_int iovcnt; 248 off_t offset; 249 }; 250 #endif 251 int 252 preadv(struct thread *td, struct preadv_args *uap) 253 { 254 struct uio *auio; 255 int error; 256 257 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 258 if (error) 259 return (error); 260 error = kern_preadv(td, uap->fd, auio, uap->offset); 261 free(auio, M_IOV); 262 return (error); 263 } 264 265 int 266 kern_preadv(td, fd, auio, offset) 267 struct thread *td; 268 int fd; 269 struct uio *auio; 270 off_t offset; 271 { 272 struct file *fp; 273 int error; 274 275 error = fget_read(td, fd, &fp); 276 if (error) 277 return (error); 278 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 279 error = ESPIPE; 280 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 281 error = EINVAL; 282 else 283 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 284 fdrop(fp, td); 285 return (error); 286 } 287 288 /* 289 * Common code for readv and preadv that reads data in 290 * from a file using the passed in uio, offset, and flags. 291 */ 292 static int 293 dofileread(td, fd, fp, auio, offset, flags) 294 struct thread *td; 295 int fd; 296 struct file *fp; 297 struct uio *auio; 298 off_t offset; 299 int flags; 300 { 301 ssize_t cnt; 302 int error; 303 #ifdef KTRACE 304 struct uio *ktruio = NULL; 305 #endif 306 307 /* Finish zero length reads right here */ 308 if (auio->uio_resid == 0) { 309 td->td_retval[0] = 0; 310 return(0); 311 } 312 auio->uio_rw = UIO_READ; 313 auio->uio_offset = offset; 314 auio->uio_td = td; 315 #ifdef KTRACE 316 if (KTRPOINT(td, KTR_GENIO)) 317 ktruio = cloneuio(auio); 318 #endif 319 cnt = auio->uio_resid; 320 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 321 if (auio->uio_resid != cnt && (error == ERESTART || 322 error == EINTR || error == EWOULDBLOCK)) 323 error = 0; 324 } 325 cnt -= auio->uio_resid; 326 #ifdef KTRACE 327 if (ktruio != NULL) { 328 ktruio->uio_resid = cnt; 329 ktrgenio(fd, UIO_READ, ktruio, error); 330 } 331 #endif 332 td->td_retval[0] = cnt; 333 return (error); 334 } 335 336 #ifndef _SYS_SYSPROTO_H_ 337 struct write_args { 338 int fd; 339 const void *buf; 340 size_t nbyte; 341 }; 342 #endif 343 int 344 write(td, uap) 345 struct thread *td; 346 struct write_args *uap; 347 { 348 struct uio auio; 349 struct iovec aiov; 350 int error; 351 352 if (uap->nbyte > INT_MAX) 353 return (EINVAL); 354 aiov.iov_base = (void *)(uintptr_t)uap->buf; 355 aiov.iov_len = uap->nbyte; 356 auio.uio_iov = &aiov; 357 auio.uio_iovcnt = 1; 358 auio.uio_resid = uap->nbyte; 359 auio.uio_segflg = UIO_USERSPACE; 360 error = kern_writev(td, uap->fd, &auio); 361 return(error); 362 } 363 364 /* 365 * Positioned write system call. 366 */ 367 #ifndef _SYS_SYSPROTO_H_ 368 struct pwrite_args { 369 int fd; 370 const void *buf; 371 size_t nbyte; 372 int pad; 373 off_t offset; 374 }; 375 #endif 376 int 377 pwrite(td, uap) 378 struct thread *td; 379 struct pwrite_args *uap; 380 { 381 struct uio auio; 382 struct iovec aiov; 383 int error; 384 385 if (uap->nbyte > INT_MAX) 386 return (EINVAL); 387 aiov.iov_base = (void *)(uintptr_t)uap->buf; 388 aiov.iov_len = uap->nbyte; 389 auio.uio_iov = &aiov; 390 auio.uio_iovcnt = 1; 391 auio.uio_resid = uap->nbyte; 392 auio.uio_segflg = UIO_USERSPACE; 393 error = kern_pwritev(td, uap->fd, &auio, uap->offset); 394 return(error); 395 } 396 397 int 398 freebsd6_pwrite(td, uap) 399 struct thread *td; 400 struct freebsd6_pwrite_args *uap; 401 { 402 struct pwrite_args oargs; 403 404 oargs.fd = uap->fd; 405 oargs.buf = uap->buf; 406 oargs.nbyte = uap->nbyte; 407 oargs.offset = uap->offset; 408 return (pwrite(td, &oargs)); 409 } 410 411 /* 412 * Gather write system call. 413 */ 414 #ifndef _SYS_SYSPROTO_H_ 415 struct writev_args { 416 int fd; 417 struct iovec *iovp; 418 u_int iovcnt; 419 }; 420 #endif 421 int 422 writev(struct thread *td, struct writev_args *uap) 423 { 424 struct uio *auio; 425 int error; 426 427 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 428 if (error) 429 return (error); 430 error = kern_writev(td, uap->fd, auio); 431 free(auio, M_IOV); 432 return (error); 433 } 434 435 int 436 kern_writev(struct thread *td, int fd, struct uio *auio) 437 { 438 struct file *fp; 439 int error; 440 441 error = fget_write(td, fd, &fp); 442 if (error) 443 return (error); 444 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 445 fdrop(fp, td); 446 return (error); 447 } 448 449 /* 450 * Gather positioned write system call. 451 */ 452 #ifndef _SYS_SYSPROTO_H_ 453 struct pwritev_args { 454 int fd; 455 struct iovec *iovp; 456 u_int iovcnt; 457 off_t offset; 458 }; 459 #endif 460 int 461 pwritev(struct thread *td, struct pwritev_args *uap) 462 { 463 struct uio *auio; 464 int error; 465 466 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 467 if (error) 468 return (error); 469 error = kern_pwritev(td, uap->fd, auio, uap->offset); 470 free(auio, M_IOV); 471 return (error); 472 } 473 474 int 475 kern_pwritev(td, fd, auio, offset) 476 struct thread *td; 477 struct uio *auio; 478 int fd; 479 off_t offset; 480 { 481 struct file *fp; 482 int error; 483 484 error = fget_write(td, fd, &fp); 485 if (error) 486 return (error); 487 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 488 error = ESPIPE; 489 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 490 error = EINVAL; 491 else 492 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 493 fdrop(fp, td); 494 return (error); 495 } 496 497 /* 498 * Common code for writev and pwritev that writes data to 499 * a file using the passed in uio, offset, and flags. 500 */ 501 static int 502 dofilewrite(td, fd, fp, auio, offset, flags) 503 struct thread *td; 504 int fd; 505 struct file *fp; 506 struct uio *auio; 507 off_t offset; 508 int flags; 509 { 510 ssize_t cnt; 511 int error; 512 #ifdef KTRACE 513 struct uio *ktruio = NULL; 514 #endif 515 516 auio->uio_rw = UIO_WRITE; 517 auio->uio_td = td; 518 auio->uio_offset = offset; 519 #ifdef KTRACE 520 if (KTRPOINT(td, KTR_GENIO)) 521 ktruio = cloneuio(auio); 522 #endif 523 cnt = auio->uio_resid; 524 if (fp->f_type == DTYPE_VNODE) 525 bwillwrite(); 526 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 527 if (auio->uio_resid != cnt && (error == ERESTART || 528 error == EINTR || error == EWOULDBLOCK)) 529 error = 0; 530 /* Socket layer is responsible for issuing SIGPIPE. */ 531 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 532 PROC_LOCK(td->td_proc); 533 psignal(td->td_proc, SIGPIPE); 534 PROC_UNLOCK(td->td_proc); 535 } 536 } 537 cnt -= auio->uio_resid; 538 #ifdef KTRACE 539 if (ktruio != NULL) { 540 ktruio->uio_resid = cnt; 541 ktrgenio(fd, UIO_WRITE, ktruio, error); 542 } 543 #endif 544 td->td_retval[0] = cnt; 545 return (error); 546 } 547 548 /* 549 * Truncate a file given a file descriptor. 550 * 551 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 552 * descriptor isn't writable. 553 */ 554 int 555 kern_ftruncate(td, fd, length) 556 struct thread *td; 557 int fd; 558 off_t length; 559 { 560 struct file *fp; 561 int error; 562 563 AUDIT_ARG(fd, fd); 564 if (length < 0) 565 return (EINVAL); 566 error = fget(td, fd, &fp); 567 if (error) 568 return (error); 569 AUDIT_ARG(file, td->td_proc, fp); 570 if (!(fp->f_flag & FWRITE)) { 571 fdrop(fp, td); 572 return (EINVAL); 573 } 574 error = fo_truncate(fp, length, td->td_ucred, td); 575 fdrop(fp, td); 576 return (error); 577 } 578 579 #ifndef _SYS_SYSPROTO_H_ 580 struct ftruncate_args { 581 int fd; 582 int pad; 583 off_t length; 584 }; 585 #endif 586 int 587 ftruncate(td, uap) 588 struct thread *td; 589 struct ftruncate_args *uap; 590 { 591 592 return (kern_ftruncate(td, uap->fd, uap->length)); 593 } 594 595 #if defined(COMPAT_43) 596 #ifndef _SYS_SYSPROTO_H_ 597 struct oftruncate_args { 598 int fd; 599 long length; 600 }; 601 #endif 602 int 603 oftruncate(td, uap) 604 struct thread *td; 605 struct oftruncate_args *uap; 606 { 607 608 return (kern_ftruncate(td, uap->fd, uap->length)); 609 } 610 #endif /* COMPAT_43 */ 611 612 #ifndef _SYS_SYSPROTO_H_ 613 struct ioctl_args { 614 int fd; 615 u_long com; 616 caddr_t data; 617 }; 618 #endif 619 /* ARGSUSED */ 620 int 621 ioctl(struct thread *td, struct ioctl_args *uap) 622 { 623 u_long com; 624 int arg, error; 625 u_int size; 626 caddr_t data; 627 628 if (uap->com > 0xffffffff) { 629 printf( 630 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 631 td->td_proc->p_pid, td->td_name, uap->com); 632 uap->com &= 0xffffffff; 633 } 634 com = uap->com; 635 636 /* 637 * Interpret high order word to find amount of data to be 638 * copied to/from the user's address space. 639 */ 640 size = IOCPARM_LEN(com); 641 if ((size > IOCPARM_MAX) || 642 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 643 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 644 ((com & IOC_OUT) && size == 0) || 645 #else 646 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 647 #endif 648 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 649 return (ENOTTY); 650 651 if (size > 0) { 652 if (!(com & IOC_VOID)) 653 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 654 else { 655 /* Integer argument. */ 656 arg = (intptr_t)uap->data; 657 data = (void *)&arg; 658 size = 0; 659 } 660 } else 661 data = (void *)&uap->data; 662 if (com & IOC_IN) { 663 error = copyin(uap->data, data, (u_int)size); 664 if (error) { 665 if (size > 0) 666 free(data, M_IOCTLOPS); 667 return (error); 668 } 669 } else if (com & IOC_OUT) { 670 /* 671 * Zero the buffer so the user always 672 * gets back something deterministic. 673 */ 674 bzero(data, size); 675 } 676 677 error = kern_ioctl(td, uap->fd, com, data); 678 679 if (error == 0 && (com & IOC_OUT)) 680 error = copyout(data, uap->data, (u_int)size); 681 682 if (size > 0) 683 free(data, M_IOCTLOPS); 684 return (error); 685 } 686 687 int 688 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 689 { 690 struct file *fp; 691 struct filedesc *fdp; 692 int error; 693 int tmp; 694 695 if ((error = fget(td, fd, &fp)) != 0) 696 return (error); 697 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 698 fdrop(fp, td); 699 return (EBADF); 700 } 701 fdp = td->td_proc->p_fd; 702 switch (com) { 703 case FIONCLEX: 704 FILEDESC_XLOCK(fdp); 705 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE; 706 FILEDESC_XUNLOCK(fdp); 707 goto out; 708 case FIOCLEX: 709 FILEDESC_XLOCK(fdp); 710 fdp->fd_ofileflags[fd] |= UF_EXCLOSE; 711 FILEDESC_XUNLOCK(fdp); 712 goto out; 713 case FIONBIO: 714 if ((tmp = *(int *)data)) 715 atomic_set_int(&fp->f_flag, FNONBLOCK); 716 else 717 atomic_clear_int(&fp->f_flag, FNONBLOCK); 718 data = (void *)&tmp; 719 break; 720 case FIOASYNC: 721 if ((tmp = *(int *)data)) 722 atomic_set_int(&fp->f_flag, FASYNC); 723 else 724 atomic_clear_int(&fp->f_flag, FASYNC); 725 data = (void *)&tmp; 726 break; 727 } 728 729 error = fo_ioctl(fp, com, data, td->td_ucred, td); 730 out: 731 fdrop(fp, td); 732 return (error); 733 } 734 735 #ifndef _SYS_SYSPROTO_H_ 736 struct select_args { 737 int nd; 738 fd_set *in, *ou, *ex; 739 struct timeval *tv; 740 }; 741 #endif 742 int 743 select(td, uap) 744 register struct thread *td; 745 register struct select_args *uap; 746 { 747 struct timeval tv, *tvp; 748 int error; 749 750 if (uap->tv != NULL) { 751 error = copyin(uap->tv, &tv, sizeof(tv)); 752 if (error) 753 return (error); 754 tvp = &tv; 755 } else 756 tvp = NULL; 757 758 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp)); 759 } 760 761 int 762 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 763 fd_set *fd_ex, struct timeval *tvp) 764 { 765 struct filedesc *fdp; 766 /* 767 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 768 * infds with the new FD_SETSIZE of 1024, and more than enough for 769 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 770 * of 256. 771 */ 772 fd_mask s_selbits[howmany(2048, NFDBITS)]; 773 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 774 struct timeval atv, rtv, ttv; 775 int error, timo; 776 u_int nbufbytes, ncpbytes, nfdbits; 777 778 if (nd < 0) 779 return (EINVAL); 780 fdp = td->td_proc->p_fd; 781 782 FILEDESC_SLOCK(fdp); 783 if (nd > td->td_proc->p_fd->fd_nfiles) 784 nd = td->td_proc->p_fd->fd_nfiles; /* forgiving; slightly wrong */ 785 FILEDESC_SUNLOCK(fdp); 786 787 /* 788 * Allocate just enough bits for the non-null fd_sets. Use the 789 * preallocated auto buffer if possible. 790 */ 791 nfdbits = roundup(nd, NFDBITS); 792 ncpbytes = nfdbits / NBBY; 793 nbufbytes = 0; 794 if (fd_in != NULL) 795 nbufbytes += 2 * ncpbytes; 796 if (fd_ou != NULL) 797 nbufbytes += 2 * ncpbytes; 798 if (fd_ex != NULL) 799 nbufbytes += 2 * ncpbytes; 800 if (nbufbytes <= sizeof s_selbits) 801 selbits = &s_selbits[0]; 802 else 803 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 804 805 /* 806 * Assign pointers into the bit buffers and fetch the input bits. 807 * Put the output buffers together so that they can be bzeroed 808 * together. 809 */ 810 sbp = selbits; 811 #define getbits(name, x) \ 812 do { \ 813 if (name == NULL) \ 814 ibits[x] = NULL; \ 815 else { \ 816 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 817 obits[x] = sbp; \ 818 sbp += ncpbytes / sizeof *sbp; \ 819 error = copyin(name, ibits[x], ncpbytes); \ 820 if (error != 0) \ 821 goto done; \ 822 } \ 823 } while (0) 824 getbits(fd_in, 0); 825 getbits(fd_ou, 1); 826 getbits(fd_ex, 2); 827 #undef getbits 828 if (nbufbytes != 0) 829 bzero(selbits, nbufbytes / 2); 830 831 if (tvp != NULL) { 832 atv = *tvp; 833 if (itimerfix(&atv)) { 834 error = EINVAL; 835 goto done; 836 } 837 getmicrouptime(&rtv); 838 timevaladd(&atv, &rtv); 839 } else { 840 atv.tv_sec = 0; 841 atv.tv_usec = 0; 842 } 843 timo = 0; 844 seltdinit(td); 845 /* Iterate until the timeout expires or descriptors become ready. */ 846 for (;;) { 847 error = selscan(td, ibits, obits, nd); 848 if (error || td->td_retval[0] != 0) 849 break; 850 if (atv.tv_sec || atv.tv_usec) { 851 getmicrouptime(&rtv); 852 if (timevalcmp(&rtv, &atv, >=)) 853 break; 854 ttv = atv; 855 timevalsub(&ttv, &rtv); 856 timo = ttv.tv_sec > 24 * 60 * 60 ? 857 24 * 60 * 60 * hz : tvtohz(&ttv); 858 } 859 error = seltdwait(td, timo); 860 if (error) 861 break; 862 error = selrescan(td, ibits, obits); 863 if (error || td->td_retval[0] != 0) 864 break; 865 } 866 seltdclear(td); 867 868 done: 869 /* select is not restarted after signals... */ 870 if (error == ERESTART) 871 error = EINTR; 872 if (error == EWOULDBLOCK) 873 error = 0; 874 #define putbits(name, x) \ 875 if (name && (error2 = copyout(obits[x], name, ncpbytes))) \ 876 error = error2; 877 if (error == 0) { 878 int error2; 879 880 putbits(fd_in, 0); 881 putbits(fd_ou, 1); 882 putbits(fd_ex, 2); 883 #undef putbits 884 } 885 if (selbits != &s_selbits[0]) 886 free(selbits, M_SELECT); 887 888 return (error); 889 } 890 891 /* 892 * Traverse the list of fds attached to this thread's seltd and check for 893 * completion. 894 */ 895 static int 896 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 897 { 898 struct seltd *stp; 899 struct selfd *sfp; 900 struct selfd *sfn; 901 struct selinfo *si; 902 struct file *fp; 903 int msk, fd; 904 int n = 0; 905 /* Note: backend also returns POLLHUP/POLLERR if appropriate. */ 906 static int flag[3] = { POLLRDNORM, POLLWRNORM, POLLRDBAND }; 907 struct filedesc *fdp = td->td_proc->p_fd; 908 909 stp = td->td_sel; 910 FILEDESC_SLOCK(fdp); 911 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 912 fd = (int)(uintptr_t)sfp->sf_cookie; 913 si = sfp->sf_si; 914 selfdfree(stp, sfp); 915 /* If the selinfo wasn't cleared the event didn't fire. */ 916 if (si != NULL) 917 continue; 918 if ((fp = fget_locked(fdp, fd)) == NULL) { 919 FILEDESC_SUNLOCK(fdp); 920 return (EBADF); 921 } 922 for (msk = 0; msk < 3; msk++) { 923 if (ibits[msk] == NULL) 924 continue; 925 if ((ibits[msk][fd/NFDBITS] & 926 ((fd_mask) 1 << (fd % NFDBITS))) == 0) 927 continue; 928 if (fo_poll(fp, flag[msk], td->td_ucred, td)) { 929 obits[msk][(fd)/NFDBITS] |= 930 ((fd_mask)1 << ((fd) % NFDBITS)); 931 n++; 932 } 933 } 934 } 935 FILEDESC_SUNLOCK(fdp); 936 stp->st_flags = 0; 937 td->td_retval[0] = n; 938 return (0); 939 } 940 941 /* 942 * Perform the initial filedescriptor scan and register ourselves with 943 * each selinfo. 944 */ 945 static int 946 selscan(td, ibits, obits, nfd) 947 struct thread *td; 948 fd_mask **ibits, **obits; 949 int nfd; 950 { 951 int msk, i, fd; 952 fd_mask bits; 953 struct file *fp; 954 int n = 0; 955 /* Note: backend also returns POLLHUP/POLLERR if appropriate. */ 956 static int flag[3] = { POLLRDNORM, POLLWRNORM, POLLRDBAND }; 957 struct filedesc *fdp = td->td_proc->p_fd; 958 959 FILEDESC_SLOCK(fdp); 960 for (msk = 0; msk < 3; msk++) { 961 if (ibits[msk] == NULL) 962 continue; 963 for (i = 0; i < nfd; i += NFDBITS) { 964 bits = ibits[msk][i/NFDBITS]; 965 /* ffs(int mask) not portable, fd_mask is long */ 966 for (fd = i; bits && fd < nfd; fd++, bits >>= 1) { 967 if (!(bits & 1)) 968 continue; 969 if ((fp = fget_locked(fdp, fd)) == NULL) { 970 FILEDESC_SUNLOCK(fdp); 971 return (EBADF); 972 } 973 selfdalloc(td, (void *)(uintptr_t)fd); 974 if (fo_poll(fp, flag[msk], td->td_ucred, 975 td)) { 976 obits[msk][(fd)/NFDBITS] |= 977 ((fd_mask)1 << ((fd) % NFDBITS)); 978 n++; 979 } 980 } 981 } 982 } 983 FILEDESC_SUNLOCK(fdp); 984 td->td_retval[0] = n; 985 return (0); 986 } 987 988 #ifndef _SYS_SYSPROTO_H_ 989 struct poll_args { 990 struct pollfd *fds; 991 u_int nfds; 992 int timeout; 993 }; 994 #endif 995 int 996 poll(td, uap) 997 struct thread *td; 998 struct poll_args *uap; 999 { 1000 struct pollfd *bits; 1001 struct pollfd smallbits[32]; 1002 struct timeval atv, rtv, ttv; 1003 int error = 0, timo; 1004 u_int nfds; 1005 size_t ni; 1006 1007 nfds = uap->nfds; 1008 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1009 return (EINVAL); 1010 ni = nfds * sizeof(struct pollfd); 1011 if (ni > sizeof(smallbits)) 1012 bits = malloc(ni, M_TEMP, M_WAITOK); 1013 else 1014 bits = smallbits; 1015 error = copyin(uap->fds, bits, ni); 1016 if (error) 1017 goto done; 1018 if (uap->timeout != INFTIM) { 1019 atv.tv_sec = uap->timeout / 1000; 1020 atv.tv_usec = (uap->timeout % 1000) * 1000; 1021 if (itimerfix(&atv)) { 1022 error = EINVAL; 1023 goto done; 1024 } 1025 getmicrouptime(&rtv); 1026 timevaladd(&atv, &rtv); 1027 } else { 1028 atv.tv_sec = 0; 1029 atv.tv_usec = 0; 1030 } 1031 timo = 0; 1032 seltdinit(td); 1033 /* Iterate until the timeout expires or descriptors become ready. */ 1034 for (;;) { 1035 error = pollscan(td, bits, nfds); 1036 if (error || td->td_retval[0] != 0) 1037 break; 1038 if (atv.tv_sec || atv.tv_usec) { 1039 getmicrouptime(&rtv); 1040 if (timevalcmp(&rtv, &atv, >=)) 1041 break; 1042 ttv = atv; 1043 timevalsub(&ttv, &rtv); 1044 timo = ttv.tv_sec > 24 * 60 * 60 ? 1045 24 * 60 * 60 * hz : tvtohz(&ttv); 1046 } 1047 error = seltdwait(td, timo); 1048 if (error) 1049 break; 1050 error = pollrescan(td); 1051 if (error || td->td_retval[0] != 0) 1052 break; 1053 } 1054 seltdclear(td); 1055 1056 done: 1057 /* poll is not restarted after signals... */ 1058 if (error == ERESTART) 1059 error = EINTR; 1060 if (error == EWOULDBLOCK) 1061 error = 0; 1062 if (error == 0) { 1063 error = copyout(bits, uap->fds, ni); 1064 if (error) 1065 goto out; 1066 } 1067 out: 1068 if (ni > sizeof(smallbits)) 1069 free(bits, M_TEMP); 1070 return (error); 1071 } 1072 1073 static int 1074 pollrescan(struct thread *td) 1075 { 1076 struct seltd *stp; 1077 struct selfd *sfp; 1078 struct selfd *sfn; 1079 struct selinfo *si; 1080 struct filedesc *fdp; 1081 struct file *fp; 1082 struct pollfd *fd; 1083 int n; 1084 1085 n = 0; 1086 fdp = td->td_proc->p_fd; 1087 stp = td->td_sel; 1088 FILEDESC_SLOCK(fdp); 1089 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1090 fd = (struct pollfd *)sfp->sf_cookie; 1091 si = sfp->sf_si; 1092 selfdfree(stp, sfp); 1093 /* If the selinfo wasn't cleared the event didn't fire. */ 1094 if (si != NULL) 1095 continue; 1096 fp = fdp->fd_ofiles[fd->fd]; 1097 if (fp == NULL) { 1098 fd->revents = POLLNVAL; 1099 n++; 1100 continue; 1101 } 1102 /* 1103 * Note: backend also returns POLLHUP and 1104 * POLLERR if appropriate. 1105 */ 1106 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1107 if (fd->revents != 0) 1108 n++; 1109 } 1110 FILEDESC_SUNLOCK(fdp); 1111 stp->st_flags = 0; 1112 td->td_retval[0] = n; 1113 return (0); 1114 } 1115 1116 1117 static int 1118 pollscan(td, fds, nfd) 1119 struct thread *td; 1120 struct pollfd *fds; 1121 u_int nfd; 1122 { 1123 struct filedesc *fdp = td->td_proc->p_fd; 1124 int i; 1125 struct file *fp; 1126 int n = 0; 1127 1128 FILEDESC_SLOCK(fdp); 1129 for (i = 0; i < nfd; i++, fds++) { 1130 if (fds->fd >= fdp->fd_nfiles) { 1131 fds->revents = POLLNVAL; 1132 n++; 1133 } else if (fds->fd < 0) { 1134 fds->revents = 0; 1135 } else { 1136 fp = fdp->fd_ofiles[fds->fd]; 1137 if (fp == NULL) { 1138 fds->revents = POLLNVAL; 1139 n++; 1140 } else { 1141 /* 1142 * Note: backend also returns POLLHUP and 1143 * POLLERR if appropriate. 1144 */ 1145 selfdalloc(td, fds); 1146 fds->revents = fo_poll(fp, fds->events, 1147 td->td_ucred, td); 1148 if (fds->revents != 0) 1149 n++; 1150 } 1151 } 1152 } 1153 FILEDESC_SUNLOCK(fdp); 1154 td->td_retval[0] = n; 1155 return (0); 1156 } 1157 1158 /* 1159 * OpenBSD poll system call. 1160 * 1161 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1162 */ 1163 #ifndef _SYS_SYSPROTO_H_ 1164 struct openbsd_poll_args { 1165 struct pollfd *fds; 1166 u_int nfds; 1167 int timeout; 1168 }; 1169 #endif 1170 int 1171 openbsd_poll(td, uap) 1172 register struct thread *td; 1173 register struct openbsd_poll_args *uap; 1174 { 1175 return (poll(td, (struct poll_args *)uap)); 1176 } 1177 1178 /* 1179 * XXX This was created specifically to support netncp and netsmb. This 1180 * allows the caller to specify a socket to wait for events on. It returns 1181 * 0 if any events matched and an error otherwise. There is no way to 1182 * determine which events fired. 1183 */ 1184 int 1185 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1186 { 1187 struct timeval atv, rtv, ttv; 1188 int error, timo; 1189 1190 if (tvp != NULL) { 1191 atv = *tvp; 1192 if (itimerfix(&atv)) 1193 return (EINVAL); 1194 getmicrouptime(&rtv); 1195 timevaladd(&atv, &rtv); 1196 } else { 1197 atv.tv_sec = 0; 1198 atv.tv_usec = 0; 1199 } 1200 1201 timo = 0; 1202 seltdinit(td); 1203 /* 1204 * Iterate until the timeout expires or the socket becomes ready. 1205 */ 1206 for (;;) { 1207 selfdalloc(td, NULL); 1208 error = sopoll(so, events, NULL, td); 1209 /* error here is actually the ready events. */ 1210 if (error) 1211 return (0); 1212 if (atv.tv_sec || atv.tv_usec) { 1213 getmicrouptime(&rtv); 1214 if (timevalcmp(&rtv, &atv, >=)) { 1215 seltdclear(td); 1216 return (EWOULDBLOCK); 1217 } 1218 ttv = atv; 1219 timevalsub(&ttv, &rtv); 1220 timo = ttv.tv_sec > 24 * 60 * 60 ? 1221 24 * 60 * 60 * hz : tvtohz(&ttv); 1222 } 1223 error = seltdwait(td, timo); 1224 seltdclear(td); 1225 if (error) 1226 break; 1227 } 1228 /* XXX Duplicates ncp/smb behavior. */ 1229 if (error == ERESTART) 1230 error = 0; 1231 return (error); 1232 } 1233 1234 /* 1235 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1236 * have two select sets, one for read and another for write. 1237 */ 1238 static void 1239 selfdalloc(struct thread *td, void *cookie) 1240 { 1241 struct seltd *stp; 1242 1243 stp = td->td_sel; 1244 if (stp->st_free1 == NULL) 1245 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1246 stp->st_free1->sf_td = stp; 1247 stp->st_free1->sf_cookie = cookie; 1248 if (stp->st_free2 == NULL) 1249 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1250 stp->st_free2->sf_td = stp; 1251 stp->st_free2->sf_cookie = cookie; 1252 } 1253 1254 static void 1255 selfdfree(struct seltd *stp, struct selfd *sfp) 1256 { 1257 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1258 mtx_lock(sfp->sf_mtx); 1259 if (sfp->sf_si) 1260 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1261 mtx_unlock(sfp->sf_mtx); 1262 uma_zfree(selfd_zone, sfp); 1263 } 1264 1265 /* 1266 * Record a select request. 1267 */ 1268 void 1269 selrecord(selector, sip) 1270 struct thread *selector; 1271 struct selinfo *sip; 1272 { 1273 struct selfd *sfp; 1274 struct seltd *stp; 1275 struct mtx *mtxp; 1276 1277 stp = selector->td_sel; 1278 /* 1279 * Don't record when doing a rescan. 1280 */ 1281 if (stp->st_flags & SELTD_RESCAN) 1282 return; 1283 /* 1284 * Grab one of the preallocated descriptors. 1285 */ 1286 sfp = NULL; 1287 if ((sfp = stp->st_free1) != NULL) 1288 stp->st_free1 = NULL; 1289 else if ((sfp = stp->st_free2) != NULL) 1290 stp->st_free2 = NULL; 1291 else 1292 panic("selrecord: No free selfd on selq"); 1293 mtxp = mtx_pool_find(mtxpool_sleep, sip); 1294 /* 1295 * Initialize the sfp and queue it in the thread. 1296 */ 1297 sfp->sf_si = sip; 1298 sfp->sf_mtx = mtxp; 1299 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1300 /* 1301 * Now that we've locked the sip, check for initialization. 1302 */ 1303 mtx_lock(mtxp); 1304 if (sip->si_mtx == NULL) { 1305 sip->si_mtx = mtxp; 1306 TAILQ_INIT(&sip->si_tdlist); 1307 } 1308 /* 1309 * Add this thread to the list of selfds listening on this selinfo. 1310 */ 1311 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1312 mtx_unlock(sip->si_mtx); 1313 } 1314 1315 /* Wake up a selecting thread. */ 1316 void 1317 selwakeup(sip) 1318 struct selinfo *sip; 1319 { 1320 doselwakeup(sip, -1); 1321 } 1322 1323 /* Wake up a selecting thread, and set its priority. */ 1324 void 1325 selwakeuppri(sip, pri) 1326 struct selinfo *sip; 1327 int pri; 1328 { 1329 doselwakeup(sip, pri); 1330 } 1331 1332 /* 1333 * Do a wakeup when a selectable event occurs. 1334 */ 1335 static void 1336 doselwakeup(sip, pri) 1337 struct selinfo *sip; 1338 int pri; 1339 { 1340 struct selfd *sfp; 1341 struct selfd *sfn; 1342 struct seltd *stp; 1343 1344 /* If it's not initialized there can't be any waiters. */ 1345 if (sip->si_mtx == NULL) 1346 return; 1347 /* 1348 * Locking the selinfo locks all selfds associated with it. 1349 */ 1350 mtx_lock(sip->si_mtx); 1351 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1352 /* 1353 * Once we remove this sfp from the list and clear the 1354 * sf_si seltdclear will know to ignore this si. 1355 */ 1356 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1357 sfp->sf_si = NULL; 1358 stp = sfp->sf_td; 1359 mtx_lock(&stp->st_mtx); 1360 stp->st_flags |= SELTD_PENDING; 1361 cv_broadcastpri(&stp->st_wait, pri); 1362 mtx_unlock(&stp->st_mtx); 1363 } 1364 mtx_unlock(sip->si_mtx); 1365 } 1366 1367 static void 1368 seltdinit(struct thread *td) 1369 { 1370 struct seltd *stp; 1371 1372 if ((stp = td->td_sel) != NULL) 1373 goto out; 1374 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1375 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1376 cv_init(&stp->st_wait, "select"); 1377 out: 1378 stp->st_flags = 0; 1379 STAILQ_INIT(&stp->st_selq); 1380 } 1381 1382 static int 1383 seltdwait(struct thread *td, int timo) 1384 { 1385 struct seltd *stp; 1386 int error; 1387 1388 stp = td->td_sel; 1389 /* 1390 * An event of interest may occur while we do not hold the seltd 1391 * locked so check the pending flag before we sleep. 1392 */ 1393 mtx_lock(&stp->st_mtx); 1394 /* 1395 * Any further calls to selrecord will be a rescan. 1396 */ 1397 stp->st_flags |= SELTD_RESCAN; 1398 if (stp->st_flags & SELTD_PENDING) { 1399 mtx_unlock(&stp->st_mtx); 1400 return (0); 1401 } 1402 if (timo > 0) 1403 error = cv_timedwait_sig(&stp->st_wait, &stp->st_mtx, timo); 1404 else 1405 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1406 mtx_unlock(&stp->st_mtx); 1407 1408 return (error); 1409 } 1410 1411 void 1412 seltdfini(struct thread *td) 1413 { 1414 struct seltd *stp; 1415 1416 stp = td->td_sel; 1417 if (stp == NULL) 1418 return; 1419 if (stp->st_free1) 1420 uma_zfree(selfd_zone, stp->st_free1); 1421 if (stp->st_free2) 1422 uma_zfree(selfd_zone, stp->st_free2); 1423 td->td_sel = NULL; 1424 free(stp, M_SELECT); 1425 } 1426 1427 /* 1428 * Remove the references to the thread from all of the objects we were 1429 * polling. 1430 */ 1431 static void 1432 seltdclear(struct thread *td) 1433 { 1434 struct seltd *stp; 1435 struct selfd *sfp; 1436 struct selfd *sfn; 1437 1438 stp = td->td_sel; 1439 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1440 selfdfree(stp, sfp); 1441 stp->st_flags = 0; 1442 } 1443 1444 static void selectinit(void *); 1445 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1446 static void 1447 selectinit(void *dummy __unused) 1448 { 1449 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1450 NULL, NULL, UMA_ALIGN_PTR, 0); 1451 } 1452