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_capsicum.h" 41 #include "opt_compat.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/capability.h> 48 #include <sys/filedesc.h> 49 #include <sys/filio.h> 50 #include <sys/fcntl.h> 51 #include <sys/file.h> 52 #include <sys/lock.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/socketvar.h> 56 #include <sys/uio.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/limits.h> 60 #include <sys/malloc.h> 61 #include <sys/poll.h> 62 #include <sys/resourcevar.h> 63 #include <sys/selinfo.h> 64 #include <sys/sleepqueue.h> 65 #include <sys/syscallsubr.h> 66 #include <sys/sysctl.h> 67 #include <sys/sysent.h> 68 #include <sys/vnode.h> 69 #include <sys/bio.h> 70 #include <sys/buf.h> 71 #include <sys/condvar.h> 72 #ifdef KTRACE 73 #include <sys/ktrace.h> 74 #endif 75 76 #include <security/audit/audit.h> 77 78 int iosize_max_clamp = 1; 79 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 80 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 81 /* 82 * Assert that the return value of read(2) and write(2) syscalls fits 83 * into a register. If not, an architecture will need to provide the 84 * usermode wrappers to reconstruct the result. 85 */ 86 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 87 88 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 89 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 90 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 91 92 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 93 u_int); 94 static int pollscan(struct thread *, struct pollfd *, u_int); 95 static int pollrescan(struct thread *); 96 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 97 static int selrescan(struct thread *, fd_mask **, fd_mask **); 98 static void selfdalloc(struct thread *, void *); 99 static void selfdfree(struct seltd *, struct selfd *); 100 static int dofileread(struct thread *, int, struct file *, struct uio *, 101 off_t, int); 102 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 103 off_t, int); 104 static void doselwakeup(struct selinfo *, int); 105 static void seltdinit(struct thread *); 106 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 107 static void seltdclear(struct thread *); 108 109 /* 110 * One seltd per-thread allocated on demand as needed. 111 * 112 * t - protected by st_mtx 113 * k - Only accessed by curthread or read-only 114 */ 115 struct seltd { 116 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 117 struct selfd *st_free1; /* (k) free fd for read set. */ 118 struct selfd *st_free2; /* (k) free fd for write set. */ 119 struct mtx st_mtx; /* Protects struct seltd */ 120 struct cv st_wait; /* (t) Wait channel. */ 121 int st_flags; /* (t) SELTD_ flags. */ 122 }; 123 124 #define SELTD_PENDING 0x0001 /* We have pending events. */ 125 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 126 127 /* 128 * One selfd allocated per-thread per-file-descriptor. 129 * f - protected by sf_mtx 130 */ 131 struct selfd { 132 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 133 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 134 struct selinfo *sf_si; /* (f) selinfo when linked. */ 135 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 136 struct seltd *sf_td; /* (k) owning seltd. */ 137 void *sf_cookie; /* (k) fd or pollfd. */ 138 }; 139 140 static uma_zone_t selfd_zone; 141 static struct mtx_pool *mtxpool_select; 142 143 #ifndef _SYS_SYSPROTO_H_ 144 struct read_args { 145 int fd; 146 void *buf; 147 size_t nbyte; 148 }; 149 #endif 150 int 151 sys_read(td, uap) 152 struct thread *td; 153 struct read_args *uap; 154 { 155 struct uio auio; 156 struct iovec aiov; 157 int error; 158 159 if (uap->nbyte > IOSIZE_MAX) 160 return (EINVAL); 161 aiov.iov_base = uap->buf; 162 aiov.iov_len = uap->nbyte; 163 auio.uio_iov = &aiov; 164 auio.uio_iovcnt = 1; 165 auio.uio_resid = uap->nbyte; 166 auio.uio_segflg = UIO_USERSPACE; 167 error = kern_readv(td, uap->fd, &auio); 168 return(error); 169 } 170 171 /* 172 * Positioned read system call 173 */ 174 #ifndef _SYS_SYSPROTO_H_ 175 struct pread_args { 176 int fd; 177 void *buf; 178 size_t nbyte; 179 int pad; 180 off_t offset; 181 }; 182 #endif 183 int 184 sys_pread(td, uap) 185 struct thread *td; 186 struct pread_args *uap; 187 { 188 struct uio auio; 189 struct iovec aiov; 190 int error; 191 192 if (uap->nbyte > IOSIZE_MAX) 193 return (EINVAL); 194 aiov.iov_base = uap->buf; 195 aiov.iov_len = uap->nbyte; 196 auio.uio_iov = &aiov; 197 auio.uio_iovcnt = 1; 198 auio.uio_resid = uap->nbyte; 199 auio.uio_segflg = UIO_USERSPACE; 200 error = kern_preadv(td, uap->fd, &auio, uap->offset); 201 return(error); 202 } 203 204 int 205 freebsd6_pread(td, uap) 206 struct thread *td; 207 struct freebsd6_pread_args *uap; 208 { 209 struct pread_args oargs; 210 211 oargs.fd = uap->fd; 212 oargs.buf = uap->buf; 213 oargs.nbyte = uap->nbyte; 214 oargs.offset = uap->offset; 215 return (sys_pread(td, &oargs)); 216 } 217 218 /* 219 * Scatter read system call. 220 */ 221 #ifndef _SYS_SYSPROTO_H_ 222 struct readv_args { 223 int fd; 224 struct iovec *iovp; 225 u_int iovcnt; 226 }; 227 #endif 228 int 229 sys_readv(struct thread *td, struct readv_args *uap) 230 { 231 struct uio *auio; 232 int error; 233 234 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 235 if (error) 236 return (error); 237 error = kern_readv(td, uap->fd, auio); 238 free(auio, M_IOV); 239 return (error); 240 } 241 242 int 243 kern_readv(struct thread *td, int fd, struct uio *auio) 244 { 245 struct file *fp; 246 int error; 247 248 error = fget_read(td, fd, CAP_READ, &fp); 249 if (error) 250 return (error); 251 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 252 fdrop(fp, td); 253 return (error); 254 } 255 256 /* 257 * Scatter positioned read system call. 258 */ 259 #ifndef _SYS_SYSPROTO_H_ 260 struct preadv_args { 261 int fd; 262 struct iovec *iovp; 263 u_int iovcnt; 264 off_t offset; 265 }; 266 #endif 267 int 268 sys_preadv(struct thread *td, struct preadv_args *uap) 269 { 270 struct uio *auio; 271 int error; 272 273 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 274 if (error) 275 return (error); 276 error = kern_preadv(td, uap->fd, auio, uap->offset); 277 free(auio, M_IOV); 278 return (error); 279 } 280 281 int 282 kern_preadv(td, fd, auio, offset) 283 struct thread *td; 284 int fd; 285 struct uio *auio; 286 off_t offset; 287 { 288 struct file *fp; 289 int error; 290 291 error = fget_read(td, fd, CAP_PREAD, &fp); 292 if (error) 293 return (error); 294 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 295 error = ESPIPE; 296 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 297 error = EINVAL; 298 else 299 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 300 fdrop(fp, td); 301 return (error); 302 } 303 304 /* 305 * Common code for readv and preadv that reads data in 306 * from a file using the passed in uio, offset, and flags. 307 */ 308 static int 309 dofileread(td, fd, fp, auio, offset, flags) 310 struct thread *td; 311 int fd; 312 struct file *fp; 313 struct uio *auio; 314 off_t offset; 315 int flags; 316 { 317 ssize_t cnt; 318 int error; 319 #ifdef KTRACE 320 struct uio *ktruio = NULL; 321 #endif 322 323 /* Finish zero length reads right here */ 324 if (auio->uio_resid == 0) { 325 td->td_retval[0] = 0; 326 return(0); 327 } 328 auio->uio_rw = UIO_READ; 329 auio->uio_offset = offset; 330 auio->uio_td = td; 331 #ifdef KTRACE 332 if (KTRPOINT(td, KTR_GENIO)) 333 ktruio = cloneuio(auio); 334 #endif 335 cnt = auio->uio_resid; 336 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 337 if (auio->uio_resid != cnt && (error == ERESTART || 338 error == EINTR || error == EWOULDBLOCK)) 339 error = 0; 340 } 341 cnt -= auio->uio_resid; 342 #ifdef KTRACE 343 if (ktruio != NULL) { 344 ktruio->uio_resid = cnt; 345 ktrgenio(fd, UIO_READ, ktruio, error); 346 } 347 #endif 348 td->td_retval[0] = cnt; 349 return (error); 350 } 351 352 #ifndef _SYS_SYSPROTO_H_ 353 struct write_args { 354 int fd; 355 const void *buf; 356 size_t nbyte; 357 }; 358 #endif 359 int 360 sys_write(td, uap) 361 struct thread *td; 362 struct write_args *uap; 363 { 364 struct uio auio; 365 struct iovec aiov; 366 int error; 367 368 if (uap->nbyte > IOSIZE_MAX) 369 return (EINVAL); 370 aiov.iov_base = (void *)(uintptr_t)uap->buf; 371 aiov.iov_len = uap->nbyte; 372 auio.uio_iov = &aiov; 373 auio.uio_iovcnt = 1; 374 auio.uio_resid = uap->nbyte; 375 auio.uio_segflg = UIO_USERSPACE; 376 error = kern_writev(td, uap->fd, &auio); 377 return(error); 378 } 379 380 /* 381 * Positioned write system call. 382 */ 383 #ifndef _SYS_SYSPROTO_H_ 384 struct pwrite_args { 385 int fd; 386 const void *buf; 387 size_t nbyte; 388 int pad; 389 off_t offset; 390 }; 391 #endif 392 int 393 sys_pwrite(td, uap) 394 struct thread *td; 395 struct pwrite_args *uap; 396 { 397 struct uio auio; 398 struct iovec aiov; 399 int error; 400 401 if (uap->nbyte > IOSIZE_MAX) 402 return (EINVAL); 403 aiov.iov_base = (void *)(uintptr_t)uap->buf; 404 aiov.iov_len = uap->nbyte; 405 auio.uio_iov = &aiov; 406 auio.uio_iovcnt = 1; 407 auio.uio_resid = uap->nbyte; 408 auio.uio_segflg = UIO_USERSPACE; 409 error = kern_pwritev(td, uap->fd, &auio, uap->offset); 410 return(error); 411 } 412 413 int 414 freebsd6_pwrite(td, uap) 415 struct thread *td; 416 struct freebsd6_pwrite_args *uap; 417 { 418 struct pwrite_args oargs; 419 420 oargs.fd = uap->fd; 421 oargs.buf = uap->buf; 422 oargs.nbyte = uap->nbyte; 423 oargs.offset = uap->offset; 424 return (sys_pwrite(td, &oargs)); 425 } 426 427 /* 428 * Gather write system call. 429 */ 430 #ifndef _SYS_SYSPROTO_H_ 431 struct writev_args { 432 int fd; 433 struct iovec *iovp; 434 u_int iovcnt; 435 }; 436 #endif 437 int 438 sys_writev(struct thread *td, struct writev_args *uap) 439 { 440 struct uio *auio; 441 int error; 442 443 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 444 if (error) 445 return (error); 446 error = kern_writev(td, uap->fd, auio); 447 free(auio, M_IOV); 448 return (error); 449 } 450 451 int 452 kern_writev(struct thread *td, int fd, struct uio *auio) 453 { 454 struct file *fp; 455 int error; 456 457 error = fget_write(td, fd, CAP_WRITE, &fp); 458 if (error) 459 return (error); 460 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 461 fdrop(fp, td); 462 return (error); 463 } 464 465 /* 466 * Gather positioned write system call. 467 */ 468 #ifndef _SYS_SYSPROTO_H_ 469 struct pwritev_args { 470 int fd; 471 struct iovec *iovp; 472 u_int iovcnt; 473 off_t offset; 474 }; 475 #endif 476 int 477 sys_pwritev(struct thread *td, struct pwritev_args *uap) 478 { 479 struct uio *auio; 480 int error; 481 482 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 483 if (error) 484 return (error); 485 error = kern_pwritev(td, uap->fd, auio, uap->offset); 486 free(auio, M_IOV); 487 return (error); 488 } 489 490 int 491 kern_pwritev(td, fd, auio, offset) 492 struct thread *td; 493 struct uio *auio; 494 int fd; 495 off_t offset; 496 { 497 struct file *fp; 498 int error; 499 500 error = fget_write(td, fd, CAP_PWRITE, &fp); 501 if (error) 502 return (error); 503 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 504 error = ESPIPE; 505 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 506 error = EINVAL; 507 else 508 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 509 fdrop(fp, td); 510 return (error); 511 } 512 513 /* 514 * Common code for writev and pwritev that writes data to 515 * a file using the passed in uio, offset, and flags. 516 */ 517 static int 518 dofilewrite(td, fd, fp, auio, offset, flags) 519 struct thread *td; 520 int fd; 521 struct file *fp; 522 struct uio *auio; 523 off_t offset; 524 int flags; 525 { 526 ssize_t cnt; 527 int error; 528 #ifdef KTRACE 529 struct uio *ktruio = NULL; 530 #endif 531 532 auio->uio_rw = UIO_WRITE; 533 auio->uio_td = td; 534 auio->uio_offset = offset; 535 #ifdef KTRACE 536 if (KTRPOINT(td, KTR_GENIO)) 537 ktruio = cloneuio(auio); 538 #endif 539 cnt = auio->uio_resid; 540 if (fp->f_type == DTYPE_VNODE && 541 (fp->f_vnread_flags & FDEVFS_VNODE) == 0) 542 bwillwrite(); 543 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 544 if (auio->uio_resid != cnt && (error == ERESTART || 545 error == EINTR || error == EWOULDBLOCK)) 546 error = 0; 547 /* Socket layer is responsible for issuing SIGPIPE. */ 548 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 549 PROC_LOCK(td->td_proc); 550 tdsignal(td, SIGPIPE); 551 PROC_UNLOCK(td->td_proc); 552 } 553 } 554 cnt -= auio->uio_resid; 555 #ifdef KTRACE 556 if (ktruio != NULL) { 557 ktruio->uio_resid = cnt; 558 ktrgenio(fd, UIO_WRITE, ktruio, error); 559 } 560 #endif 561 td->td_retval[0] = cnt; 562 return (error); 563 } 564 565 /* 566 * Truncate a file given a file descriptor. 567 * 568 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 569 * descriptor isn't writable. 570 */ 571 int 572 kern_ftruncate(td, fd, length) 573 struct thread *td; 574 int fd; 575 off_t length; 576 { 577 struct file *fp; 578 int error; 579 580 AUDIT_ARG_FD(fd); 581 if (length < 0) 582 return (EINVAL); 583 error = fget(td, fd, CAP_FTRUNCATE, &fp); 584 if (error) 585 return (error); 586 AUDIT_ARG_FILE(td->td_proc, fp); 587 if (!(fp->f_flag & FWRITE)) { 588 fdrop(fp, td); 589 return (EINVAL); 590 } 591 error = fo_truncate(fp, length, td->td_ucred, td); 592 fdrop(fp, td); 593 return (error); 594 } 595 596 #ifndef _SYS_SYSPROTO_H_ 597 struct ftruncate_args { 598 int fd; 599 int pad; 600 off_t length; 601 }; 602 #endif 603 int 604 sys_ftruncate(td, uap) 605 struct thread *td; 606 struct ftruncate_args *uap; 607 { 608 609 return (kern_ftruncate(td, uap->fd, uap->length)); 610 } 611 612 #if defined(COMPAT_43) 613 #ifndef _SYS_SYSPROTO_H_ 614 struct oftruncate_args { 615 int fd; 616 long length; 617 }; 618 #endif 619 int 620 oftruncate(td, uap) 621 struct thread *td; 622 struct oftruncate_args *uap; 623 { 624 625 return (kern_ftruncate(td, uap->fd, uap->length)); 626 } 627 #endif /* COMPAT_43 */ 628 629 #ifndef _SYS_SYSPROTO_H_ 630 struct ioctl_args { 631 int fd; 632 u_long com; 633 caddr_t data; 634 }; 635 #endif 636 /* ARGSUSED */ 637 int 638 sys_ioctl(struct thread *td, struct ioctl_args *uap) 639 { 640 u_long com; 641 int arg, error; 642 u_int size; 643 caddr_t data; 644 645 if (uap->com > 0xffffffff) { 646 printf( 647 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 648 td->td_proc->p_pid, td->td_name, uap->com); 649 uap->com &= 0xffffffff; 650 } 651 com = uap->com; 652 653 /* 654 * Interpret high order word to find amount of data to be 655 * copied to/from the user's address space. 656 */ 657 size = IOCPARM_LEN(com); 658 if ((size > IOCPARM_MAX) || 659 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 660 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 661 ((com & IOC_OUT) && size == 0) || 662 #else 663 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 664 #endif 665 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 666 return (ENOTTY); 667 668 if (size > 0) { 669 if (com & IOC_VOID) { 670 /* Integer argument. */ 671 arg = (intptr_t)uap->data; 672 data = (void *)&arg; 673 size = 0; 674 } else 675 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 676 } else 677 data = (void *)&uap->data; 678 if (com & IOC_IN) { 679 error = copyin(uap->data, data, (u_int)size); 680 if (error) { 681 if (size > 0) 682 free(data, M_IOCTLOPS); 683 return (error); 684 } 685 } else if (com & IOC_OUT) { 686 /* 687 * Zero the buffer so the user always 688 * gets back something deterministic. 689 */ 690 bzero(data, size); 691 } 692 693 error = kern_ioctl(td, uap->fd, com, data); 694 695 if (error == 0 && (com & IOC_OUT)) 696 error = copyout(data, uap->data, (u_int)size); 697 698 if (size > 0) 699 free(data, M_IOCTLOPS); 700 return (error); 701 } 702 703 int 704 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 705 { 706 struct file *fp; 707 struct filedesc *fdp; 708 int error, tmp, locked; 709 710 AUDIT_ARG_FD(fd); 711 AUDIT_ARG_CMD(com); 712 713 fdp = td->td_proc->p_fd; 714 715 switch (com) { 716 case FIONCLEX: 717 case FIOCLEX: 718 FILEDESC_XLOCK(fdp); 719 locked = LA_XLOCKED; 720 break; 721 default: 722 #ifdef CAPABILITIES 723 FILEDESC_SLOCK(fdp); 724 locked = LA_SLOCKED; 725 #else 726 locked = LA_UNLOCKED; 727 #endif 728 break; 729 } 730 731 #ifdef CAPABILITIES 732 if ((fp = fget_locked(fdp, fd)) == NULL) { 733 error = EBADF; 734 goto out; 735 } 736 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 737 fp = NULL; /* fhold() was not called yet */ 738 goto out; 739 } 740 fhold(fp); 741 if (locked == LA_SLOCKED) { 742 FILEDESC_SUNLOCK(fdp); 743 locked = LA_UNLOCKED; 744 } 745 #else 746 if ((error = fget(td, fd, CAP_IOCTL, &fp)) != 0) { 747 fp = NULL; 748 goto out; 749 } 750 #endif 751 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 752 error = EBADF; 753 goto out; 754 } 755 756 switch (com) { 757 case FIONCLEX: 758 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 759 goto out; 760 case FIOCLEX: 761 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 762 goto out; 763 case FIONBIO: 764 if ((tmp = *(int *)data)) 765 atomic_set_int(&fp->f_flag, FNONBLOCK); 766 else 767 atomic_clear_int(&fp->f_flag, FNONBLOCK); 768 data = (void *)&tmp; 769 break; 770 case FIOASYNC: 771 if ((tmp = *(int *)data)) 772 atomic_set_int(&fp->f_flag, FASYNC); 773 else 774 atomic_clear_int(&fp->f_flag, FASYNC); 775 data = (void *)&tmp; 776 break; 777 } 778 779 error = fo_ioctl(fp, com, data, td->td_ucred, td); 780 out: 781 switch (locked) { 782 case LA_XLOCKED: 783 FILEDESC_XUNLOCK(fdp); 784 break; 785 #ifdef CAPABILITIES 786 case LA_SLOCKED: 787 FILEDESC_SUNLOCK(fdp); 788 break; 789 #endif 790 default: 791 FILEDESC_UNLOCK_ASSERT(fdp); 792 break; 793 } 794 if (fp != NULL) 795 fdrop(fp, td); 796 return (error); 797 } 798 799 int 800 poll_no_poll(int events) 801 { 802 /* 803 * Return true for read/write. If the user asked for something 804 * special, return POLLNVAL, so that clients have a way of 805 * determining reliably whether or not the extended 806 * functionality is present without hard-coding knowledge 807 * of specific filesystem implementations. 808 */ 809 if (events & ~POLLSTANDARD) 810 return (POLLNVAL); 811 812 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 813 } 814 815 int 816 sys_pselect(struct thread *td, struct pselect_args *uap) 817 { 818 struct timespec ts; 819 struct timeval tv, *tvp; 820 sigset_t set, *uset; 821 int error; 822 823 if (uap->ts != NULL) { 824 error = copyin(uap->ts, &ts, sizeof(ts)); 825 if (error != 0) 826 return (error); 827 TIMESPEC_TO_TIMEVAL(&tv, &ts); 828 tvp = &tv; 829 } else 830 tvp = NULL; 831 if (uap->sm != NULL) { 832 error = copyin(uap->sm, &set, sizeof(set)); 833 if (error != 0) 834 return (error); 835 uset = &set; 836 } else 837 uset = NULL; 838 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 839 uset, NFDBITS)); 840 } 841 842 int 843 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 844 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 845 { 846 int error; 847 848 if (uset != NULL) { 849 error = kern_sigprocmask(td, SIG_SETMASK, uset, 850 &td->td_oldsigmask, 0); 851 if (error != 0) 852 return (error); 853 td->td_pflags |= TDP_OLDMASK; 854 /* 855 * Make sure that ast() is called on return to 856 * usermode and TDP_OLDMASK is cleared, restoring old 857 * sigmask. 858 */ 859 thread_lock(td); 860 td->td_flags |= TDF_ASTPENDING; 861 thread_unlock(td); 862 } 863 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 864 return (error); 865 } 866 867 #ifndef _SYS_SYSPROTO_H_ 868 struct select_args { 869 int nd; 870 fd_set *in, *ou, *ex; 871 struct timeval *tv; 872 }; 873 #endif 874 int 875 sys_select(struct thread *td, struct select_args *uap) 876 { 877 struct timeval tv, *tvp; 878 int error; 879 880 if (uap->tv != NULL) { 881 error = copyin(uap->tv, &tv, sizeof(tv)); 882 if (error) 883 return (error); 884 tvp = &tv; 885 } else 886 tvp = NULL; 887 888 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 889 NFDBITS)); 890 } 891 892 /* 893 * In the unlikely case when user specified n greater then the last 894 * open file descriptor, check that no bits are set after the last 895 * valid fd. We must return EBADF if any is set. 896 * 897 * There are applications that rely on the behaviour. 898 * 899 * nd is fd_lastfile + 1. 900 */ 901 static int 902 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 903 { 904 char *addr, *oaddr; 905 int b, i, res; 906 uint8_t bits; 907 908 if (nd >= ndu || fd_in == NULL) 909 return (0); 910 911 oaddr = NULL; 912 bits = 0; /* silence gcc */ 913 for (i = nd; i < ndu; i++) { 914 b = i / NBBY; 915 #if BYTE_ORDER == LITTLE_ENDIAN 916 addr = (char *)fd_in + b; 917 #else 918 addr = (char *)fd_in; 919 if (abi_nfdbits == NFDBITS) { 920 addr += rounddown(b, sizeof(fd_mask)) + 921 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 922 } else { 923 addr += rounddown(b, sizeof(uint32_t)) + 924 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 925 } 926 #endif 927 if (addr != oaddr) { 928 res = fubyte(addr); 929 if (res == -1) 930 return (EFAULT); 931 oaddr = addr; 932 bits = res; 933 } 934 if ((bits & (1 << (i % NBBY))) != 0) 935 return (EBADF); 936 } 937 return (0); 938 } 939 940 int 941 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 942 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 943 { 944 struct filedesc *fdp; 945 /* 946 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 947 * infds with the new FD_SETSIZE of 1024, and more than enough for 948 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 949 * of 256. 950 */ 951 fd_mask s_selbits[howmany(2048, NFDBITS)]; 952 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 953 struct timeval rtv; 954 sbintime_t asbt, precision, rsbt; 955 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 956 int error, lf, ndu; 957 958 if (nd < 0) 959 return (EINVAL); 960 fdp = td->td_proc->p_fd; 961 ndu = nd; 962 lf = fdp->fd_lastfile; 963 if (nd > lf + 1) 964 nd = lf + 1; 965 966 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 967 if (error != 0) 968 return (error); 969 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 970 if (error != 0) 971 return (error); 972 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 973 if (error != 0) 974 return (error); 975 976 /* 977 * Allocate just enough bits for the non-null fd_sets. Use the 978 * preallocated auto buffer if possible. 979 */ 980 nfdbits = roundup(nd, NFDBITS); 981 ncpbytes = nfdbits / NBBY; 982 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 983 nbufbytes = 0; 984 if (fd_in != NULL) 985 nbufbytes += 2 * ncpbytes; 986 if (fd_ou != NULL) 987 nbufbytes += 2 * ncpbytes; 988 if (fd_ex != NULL) 989 nbufbytes += 2 * ncpbytes; 990 if (nbufbytes <= sizeof s_selbits) 991 selbits = &s_selbits[0]; 992 else 993 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 994 995 /* 996 * Assign pointers into the bit buffers and fetch the input bits. 997 * Put the output buffers together so that they can be bzeroed 998 * together. 999 */ 1000 sbp = selbits; 1001 #define getbits(name, x) \ 1002 do { \ 1003 if (name == NULL) { \ 1004 ibits[x] = NULL; \ 1005 obits[x] = NULL; \ 1006 } else { \ 1007 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1008 obits[x] = sbp; \ 1009 sbp += ncpbytes / sizeof *sbp; \ 1010 error = copyin(name, ibits[x], ncpubytes); \ 1011 if (error != 0) \ 1012 goto done; \ 1013 bzero((char *)ibits[x] + ncpubytes, \ 1014 ncpbytes - ncpubytes); \ 1015 } \ 1016 } while (0) 1017 getbits(fd_in, 0); 1018 getbits(fd_ou, 1); 1019 getbits(fd_ex, 2); 1020 #undef getbits 1021 1022 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1023 /* 1024 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1025 * we are running under 32-bit emulation. This should be more 1026 * generic. 1027 */ 1028 #define swizzle_fdset(bits) \ 1029 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1030 int i; \ 1031 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1032 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1033 } 1034 #else 1035 #define swizzle_fdset(bits) 1036 #endif 1037 1038 /* Make sure the bit order makes it through an ABI transition */ 1039 swizzle_fdset(ibits[0]); 1040 swizzle_fdset(ibits[1]); 1041 swizzle_fdset(ibits[2]); 1042 1043 if (nbufbytes != 0) 1044 bzero(selbits, nbufbytes / 2); 1045 1046 precision = 0; 1047 if (tvp != NULL) { 1048 rtv = *tvp; 1049 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1050 rtv.tv_usec >= 1000000) { 1051 error = EINVAL; 1052 goto done; 1053 } 1054 if (!timevalisset(&rtv)) 1055 asbt = 0; 1056 else if (rtv.tv_sec <= INT32_MAX) { 1057 rsbt = tvtosbt(rtv); 1058 precision = rsbt; 1059 precision >>= tc_precexp; 1060 if (TIMESEL(&asbt, rsbt)) 1061 asbt += tc_tick_sbt; 1062 if (asbt <= INT64_MAX - rsbt) 1063 asbt += rsbt; 1064 else 1065 asbt = -1; 1066 } else 1067 asbt = -1; 1068 } else 1069 asbt = -1; 1070 seltdinit(td); 1071 /* Iterate until the timeout expires or descriptors become ready. */ 1072 for (;;) { 1073 error = selscan(td, ibits, obits, nd); 1074 if (error || td->td_retval[0] != 0) 1075 break; 1076 error = seltdwait(td, asbt, precision); 1077 if (error) 1078 break; 1079 error = selrescan(td, ibits, obits); 1080 if (error || td->td_retval[0] != 0) 1081 break; 1082 } 1083 seltdclear(td); 1084 1085 done: 1086 /* select is not restarted after signals... */ 1087 if (error == ERESTART) 1088 error = EINTR; 1089 if (error == EWOULDBLOCK) 1090 error = 0; 1091 1092 /* swizzle bit order back, if necessary */ 1093 swizzle_fdset(obits[0]); 1094 swizzle_fdset(obits[1]); 1095 swizzle_fdset(obits[2]); 1096 #undef swizzle_fdset 1097 1098 #define putbits(name, x) \ 1099 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1100 error = error2; 1101 if (error == 0) { 1102 int error2; 1103 1104 putbits(fd_in, 0); 1105 putbits(fd_ou, 1); 1106 putbits(fd_ex, 2); 1107 #undef putbits 1108 } 1109 if (selbits != &s_selbits[0]) 1110 free(selbits, M_SELECT); 1111 1112 return (error); 1113 } 1114 /* 1115 * Convert a select bit set to poll flags. 1116 * 1117 * The backend always returns POLLHUP/POLLERR if appropriate and we 1118 * return this as a set bit in any set. 1119 */ 1120 static int select_flags[3] = { 1121 POLLRDNORM | POLLHUP | POLLERR, 1122 POLLWRNORM | POLLHUP | POLLERR, 1123 POLLRDBAND | POLLERR 1124 }; 1125 1126 /* 1127 * Compute the fo_poll flags required for a fd given by the index and 1128 * bit position in the fd_mask array. 1129 */ 1130 static __inline int 1131 selflags(fd_mask **ibits, int idx, fd_mask bit) 1132 { 1133 int flags; 1134 int msk; 1135 1136 flags = 0; 1137 for (msk = 0; msk < 3; msk++) { 1138 if (ibits[msk] == NULL) 1139 continue; 1140 if ((ibits[msk][idx] & bit) == 0) 1141 continue; 1142 flags |= select_flags[msk]; 1143 } 1144 return (flags); 1145 } 1146 1147 /* 1148 * Set the appropriate output bits given a mask of fired events and the 1149 * input bits originally requested. 1150 */ 1151 static __inline int 1152 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1153 { 1154 int msk; 1155 int n; 1156 1157 n = 0; 1158 for (msk = 0; msk < 3; msk++) { 1159 if ((events & select_flags[msk]) == 0) 1160 continue; 1161 if (ibits[msk] == NULL) 1162 continue; 1163 if ((ibits[msk][idx] & bit) == 0) 1164 continue; 1165 /* 1166 * XXX Check for a duplicate set. This can occur because a 1167 * socket calls selrecord() twice for each poll() call 1168 * resulting in two selfds per real fd. selrescan() will 1169 * call selsetbits twice as a result. 1170 */ 1171 if ((obits[msk][idx] & bit) != 0) 1172 continue; 1173 obits[msk][idx] |= bit; 1174 n++; 1175 } 1176 1177 return (n); 1178 } 1179 1180 static __inline int 1181 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1182 { 1183 1184 return (fget_unlocked(fdp, fd, CAP_POLL_EVENT, 0, fpp, NULL)); 1185 } 1186 1187 /* 1188 * Traverse the list of fds attached to this thread's seltd and check for 1189 * completion. 1190 */ 1191 static int 1192 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1193 { 1194 struct filedesc *fdp; 1195 struct selinfo *si; 1196 struct seltd *stp; 1197 struct selfd *sfp; 1198 struct selfd *sfn; 1199 struct file *fp; 1200 fd_mask bit; 1201 int fd, ev, n, idx; 1202 int error; 1203 1204 fdp = td->td_proc->p_fd; 1205 stp = td->td_sel; 1206 n = 0; 1207 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1208 fd = (int)(uintptr_t)sfp->sf_cookie; 1209 si = sfp->sf_si; 1210 selfdfree(stp, sfp); 1211 /* If the selinfo wasn't cleared the event didn't fire. */ 1212 if (si != NULL) 1213 continue; 1214 error = getselfd_cap(fdp, fd, &fp); 1215 if (error) 1216 return (error); 1217 idx = fd / NFDBITS; 1218 bit = (fd_mask)1 << (fd % NFDBITS); 1219 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1220 fdrop(fp, td); 1221 if (ev != 0) 1222 n += selsetbits(ibits, obits, idx, bit, ev); 1223 } 1224 stp->st_flags = 0; 1225 td->td_retval[0] = n; 1226 return (0); 1227 } 1228 1229 /* 1230 * Perform the initial filedescriptor scan and register ourselves with 1231 * each selinfo. 1232 */ 1233 static int 1234 selscan(td, ibits, obits, nfd) 1235 struct thread *td; 1236 fd_mask **ibits, **obits; 1237 int nfd; 1238 { 1239 struct filedesc *fdp; 1240 struct file *fp; 1241 fd_mask bit; 1242 int ev, flags, end, fd; 1243 int n, idx; 1244 int error; 1245 1246 fdp = td->td_proc->p_fd; 1247 n = 0; 1248 for (idx = 0, fd = 0; fd < nfd; idx++) { 1249 end = imin(fd + NFDBITS, nfd); 1250 for (bit = 1; fd < end; bit <<= 1, fd++) { 1251 /* Compute the list of events we're interested in. */ 1252 flags = selflags(ibits, idx, bit); 1253 if (flags == 0) 1254 continue; 1255 error = getselfd_cap(fdp, fd, &fp); 1256 if (error) 1257 return (error); 1258 selfdalloc(td, (void *)(uintptr_t)fd); 1259 ev = fo_poll(fp, flags, td->td_ucred, td); 1260 fdrop(fp, td); 1261 if (ev != 0) 1262 n += selsetbits(ibits, obits, idx, bit, ev); 1263 } 1264 } 1265 1266 td->td_retval[0] = n; 1267 return (0); 1268 } 1269 1270 #ifndef _SYS_SYSPROTO_H_ 1271 struct poll_args { 1272 struct pollfd *fds; 1273 u_int nfds; 1274 int timeout; 1275 }; 1276 #endif 1277 int 1278 sys_poll(td, uap) 1279 struct thread *td; 1280 struct poll_args *uap; 1281 { 1282 struct pollfd *bits; 1283 struct pollfd smallbits[32]; 1284 sbintime_t asbt, precision, rsbt; 1285 u_int nfds; 1286 int error; 1287 size_t ni; 1288 1289 nfds = uap->nfds; 1290 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1291 return (EINVAL); 1292 ni = nfds * sizeof(struct pollfd); 1293 if (ni > sizeof(smallbits)) 1294 bits = malloc(ni, M_TEMP, M_WAITOK); 1295 else 1296 bits = smallbits; 1297 error = copyin(uap->fds, bits, ni); 1298 if (error) 1299 goto done; 1300 precision = 0; 1301 if (uap->timeout != INFTIM) { 1302 if (uap->timeout < 0) { 1303 error = EINVAL; 1304 goto done; 1305 } 1306 if (uap->timeout == 0) 1307 asbt = 0; 1308 else { 1309 rsbt = SBT_1MS * uap->timeout; 1310 precision = rsbt; 1311 precision >>= tc_precexp; 1312 if (TIMESEL(&asbt, rsbt)) 1313 asbt += tc_tick_sbt; 1314 asbt += rsbt; 1315 } 1316 } else 1317 asbt = -1; 1318 seltdinit(td); 1319 /* Iterate until the timeout expires or descriptors become ready. */ 1320 for (;;) { 1321 error = pollscan(td, bits, nfds); 1322 if (error || td->td_retval[0] != 0) 1323 break; 1324 error = seltdwait(td, asbt, precision); 1325 if (error) 1326 break; 1327 error = pollrescan(td); 1328 if (error || td->td_retval[0] != 0) 1329 break; 1330 } 1331 seltdclear(td); 1332 1333 done: 1334 /* poll is not restarted after signals... */ 1335 if (error == ERESTART) 1336 error = EINTR; 1337 if (error == EWOULDBLOCK) 1338 error = 0; 1339 if (error == 0) { 1340 error = pollout(td, bits, uap->fds, nfds); 1341 if (error) 1342 goto out; 1343 } 1344 out: 1345 if (ni > sizeof(smallbits)) 1346 free(bits, M_TEMP); 1347 return (error); 1348 } 1349 1350 static int 1351 pollrescan(struct thread *td) 1352 { 1353 struct seltd *stp; 1354 struct selfd *sfp; 1355 struct selfd *sfn; 1356 struct selinfo *si; 1357 struct filedesc *fdp; 1358 struct file *fp; 1359 struct pollfd *fd; 1360 int n; 1361 1362 n = 0; 1363 fdp = td->td_proc->p_fd; 1364 stp = td->td_sel; 1365 FILEDESC_SLOCK(fdp); 1366 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1367 fd = (struct pollfd *)sfp->sf_cookie; 1368 si = sfp->sf_si; 1369 selfdfree(stp, sfp); 1370 /* If the selinfo wasn't cleared the event didn't fire. */ 1371 if (si != NULL) 1372 continue; 1373 fp = fdp->fd_ofiles[fd->fd].fde_file; 1374 #ifdef CAPABILITIES 1375 if (fp == NULL || 1376 cap_check(cap_rights(fdp, fd->fd), CAP_POLL_EVENT) != 0) 1377 #else 1378 if (fp == NULL) 1379 #endif 1380 { 1381 fd->revents = POLLNVAL; 1382 n++; 1383 continue; 1384 } 1385 1386 /* 1387 * Note: backend also returns POLLHUP and 1388 * POLLERR if appropriate. 1389 */ 1390 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1391 if (fd->revents != 0) 1392 n++; 1393 } 1394 FILEDESC_SUNLOCK(fdp); 1395 stp->st_flags = 0; 1396 td->td_retval[0] = n; 1397 return (0); 1398 } 1399 1400 1401 static int 1402 pollout(td, fds, ufds, nfd) 1403 struct thread *td; 1404 struct pollfd *fds; 1405 struct pollfd *ufds; 1406 u_int nfd; 1407 { 1408 int error = 0; 1409 u_int i = 0; 1410 u_int n = 0; 1411 1412 for (i = 0; i < nfd; i++) { 1413 error = copyout(&fds->revents, &ufds->revents, 1414 sizeof(ufds->revents)); 1415 if (error) 1416 return (error); 1417 if (fds->revents != 0) 1418 n++; 1419 fds++; 1420 ufds++; 1421 } 1422 td->td_retval[0] = n; 1423 return (0); 1424 } 1425 1426 static int 1427 pollscan(td, fds, nfd) 1428 struct thread *td; 1429 struct pollfd *fds; 1430 u_int nfd; 1431 { 1432 struct filedesc *fdp = td->td_proc->p_fd; 1433 struct file *fp; 1434 int i, n = 0; 1435 1436 FILEDESC_SLOCK(fdp); 1437 for (i = 0; i < nfd; i++, fds++) { 1438 if (fds->fd >= fdp->fd_nfiles) { 1439 fds->revents = POLLNVAL; 1440 n++; 1441 } else if (fds->fd < 0) { 1442 fds->revents = 0; 1443 } else { 1444 fp = fdp->fd_ofiles[fds->fd].fde_file; 1445 #ifdef CAPABILITIES 1446 if (fp == NULL || 1447 cap_check(cap_rights(fdp, fds->fd), 1448 CAP_POLL_EVENT) != 0) 1449 #else 1450 if (fp == NULL) 1451 #endif 1452 { 1453 fds->revents = POLLNVAL; 1454 n++; 1455 } else { 1456 /* 1457 * Note: backend also returns POLLHUP and 1458 * POLLERR if appropriate. 1459 */ 1460 selfdalloc(td, fds); 1461 fds->revents = fo_poll(fp, fds->events, 1462 td->td_ucred, td); 1463 /* 1464 * POSIX requires POLLOUT to be never 1465 * set simultaneously with POLLHUP. 1466 */ 1467 if ((fds->revents & POLLHUP) != 0) 1468 fds->revents &= ~POLLOUT; 1469 1470 if (fds->revents != 0) 1471 n++; 1472 } 1473 } 1474 } 1475 FILEDESC_SUNLOCK(fdp); 1476 td->td_retval[0] = n; 1477 return (0); 1478 } 1479 1480 /* 1481 * OpenBSD poll system call. 1482 * 1483 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1484 */ 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct openbsd_poll_args { 1487 struct pollfd *fds; 1488 u_int nfds; 1489 int timeout; 1490 }; 1491 #endif 1492 int 1493 sys_openbsd_poll(td, uap) 1494 register struct thread *td; 1495 register struct openbsd_poll_args *uap; 1496 { 1497 return (sys_poll(td, (struct poll_args *)uap)); 1498 } 1499 1500 /* 1501 * XXX This was created specifically to support netncp and netsmb. This 1502 * allows the caller to specify a socket to wait for events on. It returns 1503 * 0 if any events matched and an error otherwise. There is no way to 1504 * determine which events fired. 1505 */ 1506 int 1507 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1508 { 1509 struct timeval rtv; 1510 sbintime_t asbt, precision, rsbt; 1511 int error; 1512 1513 precision = 0; /* stupid gcc! */ 1514 if (tvp != NULL) { 1515 rtv = *tvp; 1516 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1517 rtv.tv_usec >= 1000000) 1518 return (EINVAL); 1519 if (!timevalisset(&rtv)) 1520 asbt = 0; 1521 else if (rtv.tv_sec <= INT32_MAX) { 1522 rsbt = tvtosbt(rtv); 1523 precision = rsbt; 1524 precision >>= tc_precexp; 1525 if (TIMESEL(&asbt, rsbt)) 1526 asbt += tc_tick_sbt; 1527 if (asbt <= INT64_MAX - rsbt) 1528 asbt += rsbt; 1529 else 1530 asbt = -1; 1531 } else 1532 asbt = -1; 1533 } else 1534 asbt = -1; 1535 seltdinit(td); 1536 /* 1537 * Iterate until the timeout expires or the socket becomes ready. 1538 */ 1539 for (;;) { 1540 selfdalloc(td, NULL); 1541 error = sopoll(so, events, NULL, td); 1542 /* error here is actually the ready events. */ 1543 if (error) 1544 return (0); 1545 error = seltdwait(td, asbt, precision); 1546 if (error) 1547 break; 1548 } 1549 seltdclear(td); 1550 /* XXX Duplicates ncp/smb behavior. */ 1551 if (error == ERESTART) 1552 error = 0; 1553 return (error); 1554 } 1555 1556 /* 1557 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1558 * have two select sets, one for read and another for write. 1559 */ 1560 static void 1561 selfdalloc(struct thread *td, void *cookie) 1562 { 1563 struct seltd *stp; 1564 1565 stp = td->td_sel; 1566 if (stp->st_free1 == NULL) 1567 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1568 stp->st_free1->sf_td = stp; 1569 stp->st_free1->sf_cookie = cookie; 1570 if (stp->st_free2 == NULL) 1571 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1572 stp->st_free2->sf_td = stp; 1573 stp->st_free2->sf_cookie = cookie; 1574 } 1575 1576 static void 1577 selfdfree(struct seltd *stp, struct selfd *sfp) 1578 { 1579 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1580 mtx_lock(sfp->sf_mtx); 1581 if (sfp->sf_si) 1582 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1583 mtx_unlock(sfp->sf_mtx); 1584 uma_zfree(selfd_zone, sfp); 1585 } 1586 1587 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1588 void 1589 seldrain(sip) 1590 struct selinfo *sip; 1591 { 1592 1593 /* 1594 * This feature is already provided by doselwakeup(), thus it is 1595 * enough to go for it. 1596 * Eventually, the context, should take care to avoid races 1597 * between thread calling select()/poll() and file descriptor 1598 * detaching, but, again, the races are just the same as 1599 * selwakeup(). 1600 */ 1601 doselwakeup(sip, -1); 1602 } 1603 1604 /* 1605 * Record a select request. 1606 */ 1607 void 1608 selrecord(selector, sip) 1609 struct thread *selector; 1610 struct selinfo *sip; 1611 { 1612 struct selfd *sfp; 1613 struct seltd *stp; 1614 struct mtx *mtxp; 1615 1616 stp = selector->td_sel; 1617 /* 1618 * Don't record when doing a rescan. 1619 */ 1620 if (stp->st_flags & SELTD_RESCAN) 1621 return; 1622 /* 1623 * Grab one of the preallocated descriptors. 1624 */ 1625 sfp = NULL; 1626 if ((sfp = stp->st_free1) != NULL) 1627 stp->st_free1 = NULL; 1628 else if ((sfp = stp->st_free2) != NULL) 1629 stp->st_free2 = NULL; 1630 else 1631 panic("selrecord: No free selfd on selq"); 1632 mtxp = sip->si_mtx; 1633 if (mtxp == NULL) 1634 mtxp = mtx_pool_find(mtxpool_select, sip); 1635 /* 1636 * Initialize the sfp and queue it in the thread. 1637 */ 1638 sfp->sf_si = sip; 1639 sfp->sf_mtx = mtxp; 1640 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1641 /* 1642 * Now that we've locked the sip, check for initialization. 1643 */ 1644 mtx_lock(mtxp); 1645 if (sip->si_mtx == NULL) { 1646 sip->si_mtx = mtxp; 1647 TAILQ_INIT(&sip->si_tdlist); 1648 } 1649 /* 1650 * Add this thread to the list of selfds listening on this selinfo. 1651 */ 1652 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1653 mtx_unlock(sip->si_mtx); 1654 } 1655 1656 /* Wake up a selecting thread. */ 1657 void 1658 selwakeup(sip) 1659 struct selinfo *sip; 1660 { 1661 doselwakeup(sip, -1); 1662 } 1663 1664 /* Wake up a selecting thread, and set its priority. */ 1665 void 1666 selwakeuppri(sip, pri) 1667 struct selinfo *sip; 1668 int pri; 1669 { 1670 doselwakeup(sip, pri); 1671 } 1672 1673 /* 1674 * Do a wakeup when a selectable event occurs. 1675 */ 1676 static void 1677 doselwakeup(sip, pri) 1678 struct selinfo *sip; 1679 int pri; 1680 { 1681 struct selfd *sfp; 1682 struct selfd *sfn; 1683 struct seltd *stp; 1684 1685 /* If it's not initialized there can't be any waiters. */ 1686 if (sip->si_mtx == NULL) 1687 return; 1688 /* 1689 * Locking the selinfo locks all selfds associated with it. 1690 */ 1691 mtx_lock(sip->si_mtx); 1692 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1693 /* 1694 * Once we remove this sfp from the list and clear the 1695 * sf_si seltdclear will know to ignore this si. 1696 */ 1697 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1698 sfp->sf_si = NULL; 1699 stp = sfp->sf_td; 1700 mtx_lock(&stp->st_mtx); 1701 stp->st_flags |= SELTD_PENDING; 1702 cv_broadcastpri(&stp->st_wait, pri); 1703 mtx_unlock(&stp->st_mtx); 1704 } 1705 mtx_unlock(sip->si_mtx); 1706 } 1707 1708 static void 1709 seltdinit(struct thread *td) 1710 { 1711 struct seltd *stp; 1712 1713 if ((stp = td->td_sel) != NULL) 1714 goto out; 1715 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1716 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1717 cv_init(&stp->st_wait, "select"); 1718 out: 1719 stp->st_flags = 0; 1720 STAILQ_INIT(&stp->st_selq); 1721 } 1722 1723 static int 1724 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1725 { 1726 struct seltd *stp; 1727 int error; 1728 1729 stp = td->td_sel; 1730 /* 1731 * An event of interest may occur while we do not hold the seltd 1732 * locked so check the pending flag before we sleep. 1733 */ 1734 mtx_lock(&stp->st_mtx); 1735 /* 1736 * Any further calls to selrecord will be a rescan. 1737 */ 1738 stp->st_flags |= SELTD_RESCAN; 1739 if (stp->st_flags & SELTD_PENDING) { 1740 mtx_unlock(&stp->st_mtx); 1741 return (0); 1742 } 1743 if (sbt == 0) 1744 error = EWOULDBLOCK; 1745 else if (sbt != -1) 1746 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1747 sbt, precision, C_ABSOLUTE); 1748 else 1749 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1750 mtx_unlock(&stp->st_mtx); 1751 1752 return (error); 1753 } 1754 1755 void 1756 seltdfini(struct thread *td) 1757 { 1758 struct seltd *stp; 1759 1760 stp = td->td_sel; 1761 if (stp == NULL) 1762 return; 1763 if (stp->st_free1) 1764 uma_zfree(selfd_zone, stp->st_free1); 1765 if (stp->st_free2) 1766 uma_zfree(selfd_zone, stp->st_free2); 1767 td->td_sel = NULL; 1768 free(stp, M_SELECT); 1769 } 1770 1771 /* 1772 * Remove the references to the thread from all of the objects we were 1773 * polling. 1774 */ 1775 static void 1776 seltdclear(struct thread *td) 1777 { 1778 struct seltd *stp; 1779 struct selfd *sfp; 1780 struct selfd *sfn; 1781 1782 stp = td->td_sel; 1783 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1784 selfdfree(stp, sfp); 1785 stp->st_flags = 0; 1786 } 1787 1788 static void selectinit(void *); 1789 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1790 static void 1791 selectinit(void *dummy __unused) 1792 { 1793 1794 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1795 NULL, NULL, UMA_ALIGN_PTR, 0); 1796 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1797 } 1798