1 /* $NetBSD: kern_descrip.c,v 1.249 2020/08/28 10:20:14 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1982, 1986, 1989, 1991, 1993 34 * The Regents of the University of California. All rights reserved. 35 * (c) UNIX System Laboratories, Inc. 36 * All or some portions of this file are derived from material licensed 37 * to the University of California by American Telephone and Telegraph 38 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 39 * the permission of UNIX System Laboratories, Inc. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)kern_descrip.c 8.8 (Berkeley) 2/14/95 66 */ 67 68 /* 69 * File descriptor management. 70 */ 71 72 #include <sys/cdefs.h> 73 __KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.249 2020/08/28 10:20:14 christos Exp $"); 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/filedesc.h> 78 #include <sys/kernel.h> 79 #include <sys/proc.h> 80 #include <sys/file.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/stat.h> 84 #include <sys/ioctl.h> 85 #include <sys/fcntl.h> 86 #include <sys/pool.h> 87 #include <sys/unistd.h> 88 #include <sys/resourcevar.h> 89 #include <sys/conf.h> 90 #include <sys/event.h> 91 #include <sys/kauth.h> 92 #include <sys/atomic.h> 93 #include <sys/syscallargs.h> 94 #include <sys/cpu.h> 95 #include <sys/kmem.h> 96 #include <sys/vnode.h> 97 #include <sys/sysctl.h> 98 #include <sys/ktrace.h> 99 100 /* 101 * A list (head) of open files, counter, and lock protecting them. 102 */ 103 struct filelist filehead __cacheline_aligned; 104 static u_int nfiles __cacheline_aligned; 105 kmutex_t filelist_lock __cacheline_aligned; 106 107 static pool_cache_t filedesc_cache __read_mostly; 108 static pool_cache_t file_cache __read_mostly; 109 static pool_cache_t fdfile_cache __read_mostly; 110 111 static int file_ctor(void *, void *, int); 112 static void file_dtor(void *, void *); 113 static int fdfile_ctor(void *, void *, int); 114 static void fdfile_dtor(void *, void *); 115 static int filedesc_ctor(void *, void *, int); 116 static void filedesc_dtor(void *, void *); 117 static int filedescopen(dev_t, int, int, lwp_t *); 118 119 static int sysctl_kern_file(SYSCTLFN_PROTO); 120 static int sysctl_kern_file2(SYSCTLFN_PROTO); 121 static void fill_file(struct file *, const struct file *); 122 static void fill_file2(struct kinfo_file *, const file_t *, const fdfile_t *, 123 int, pid_t); 124 125 const struct cdevsw filedesc_cdevsw = { 126 .d_open = filedescopen, 127 .d_close = noclose, 128 .d_read = noread, 129 .d_write = nowrite, 130 .d_ioctl = noioctl, 131 .d_stop = nostop, 132 .d_tty = notty, 133 .d_poll = nopoll, 134 .d_mmap = nommap, 135 .d_kqfilter = nokqfilter, 136 .d_discard = nodiscard, 137 .d_flag = D_OTHER | D_MPSAFE 138 }; 139 140 /* For ease of reading. */ 141 __strong_alias(fd_putvnode,fd_putfile) 142 __strong_alias(fd_putsock,fd_putfile) 143 144 /* 145 * Initialize the descriptor system. 146 */ 147 void 148 fd_sys_init(void) 149 { 150 static struct sysctllog *clog; 151 152 mutex_init(&filelist_lock, MUTEX_DEFAULT, IPL_NONE); 153 154 LIST_INIT(&filehead); 155 156 file_cache = pool_cache_init(sizeof(file_t), coherency_unit, 0, 157 0, "file", NULL, IPL_NONE, file_ctor, file_dtor, NULL); 158 KASSERT(file_cache != NULL); 159 160 fdfile_cache = pool_cache_init(sizeof(fdfile_t), coherency_unit, 0, 161 PR_LARGECACHE, "fdfile", NULL, IPL_NONE, fdfile_ctor, fdfile_dtor, 162 NULL); 163 KASSERT(fdfile_cache != NULL); 164 165 filedesc_cache = pool_cache_init(sizeof(filedesc_t), coherency_unit, 166 0, 0, "filedesc", NULL, IPL_NONE, filedesc_ctor, filedesc_dtor, 167 NULL); 168 KASSERT(filedesc_cache != NULL); 169 170 sysctl_createv(&clog, 0, NULL, NULL, 171 CTLFLAG_PERMANENT, 172 CTLTYPE_STRUCT, "file", 173 SYSCTL_DESCR("System open file table"), 174 sysctl_kern_file, 0, NULL, 0, 175 CTL_KERN, KERN_FILE, CTL_EOL); 176 sysctl_createv(&clog, 0, NULL, NULL, 177 CTLFLAG_PERMANENT, 178 CTLTYPE_STRUCT, "file2", 179 SYSCTL_DESCR("System open file table"), 180 sysctl_kern_file2, 0, NULL, 0, 181 CTL_KERN, KERN_FILE2, CTL_EOL); 182 } 183 184 static bool 185 fd_isused(filedesc_t *fdp, unsigned fd) 186 { 187 u_int off = fd >> NDENTRYSHIFT; 188 189 KASSERT(fd < atomic_load_consume(&fdp->fd_dt)->dt_nfiles); 190 191 return (fdp->fd_lomap[off] & (1U << (fd & NDENTRYMASK))) != 0; 192 } 193 194 /* 195 * Verify that the bitmaps match the descriptor table. 196 */ 197 static inline void 198 fd_checkmaps(filedesc_t *fdp) 199 { 200 #ifdef DEBUG 201 fdtab_t *dt; 202 u_int fd; 203 204 KASSERT(fdp->fd_refcnt <= 1 || mutex_owned(&fdp->fd_lock)); 205 206 dt = fdp->fd_dt; 207 if (fdp->fd_refcnt == -1) { 208 /* 209 * fd_free tears down the table without maintaining its bitmap. 210 */ 211 return; 212 } 213 for (fd = 0; fd < dt->dt_nfiles; fd++) { 214 if (fd < NDFDFILE) { 215 KASSERT(dt->dt_ff[fd] == 216 (fdfile_t *)fdp->fd_dfdfile[fd]); 217 } 218 if (dt->dt_ff[fd] == NULL) { 219 KASSERT(!fd_isused(fdp, fd)); 220 } else if (dt->dt_ff[fd]->ff_file != NULL) { 221 KASSERT(fd_isused(fdp, fd)); 222 } 223 } 224 #endif 225 } 226 227 static int 228 fd_next_zero(filedesc_t *fdp, uint32_t *bitmap, int want, u_int bits) 229 { 230 int i, off, maxoff; 231 uint32_t sub; 232 233 KASSERT(mutex_owned(&fdp->fd_lock)); 234 235 fd_checkmaps(fdp); 236 237 if (want > bits) 238 return -1; 239 240 off = want >> NDENTRYSHIFT; 241 i = want & NDENTRYMASK; 242 if (i) { 243 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); 244 if (sub != ~0) 245 goto found; 246 off++; 247 } 248 249 maxoff = NDLOSLOTS(bits); 250 while (off < maxoff) { 251 if ((sub = bitmap[off]) != ~0) 252 goto found; 253 off++; 254 } 255 256 return -1; 257 258 found: 259 return (off << NDENTRYSHIFT) + ffs(~sub) - 1; 260 } 261 262 static int 263 fd_last_set(filedesc_t *fd, int last) 264 { 265 int off, i; 266 fdfile_t **ff = fd->fd_dt->dt_ff; 267 uint32_t *bitmap = fd->fd_lomap; 268 269 KASSERT(mutex_owned(&fd->fd_lock)); 270 271 fd_checkmaps(fd); 272 273 off = (last - 1) >> NDENTRYSHIFT; 274 275 while (off >= 0 && !bitmap[off]) 276 off--; 277 278 if (off < 0) 279 return -1; 280 281 i = ((off + 1) << NDENTRYSHIFT) - 1; 282 if (i >= last) 283 i = last - 1; 284 285 /* XXX should use bitmap */ 286 while (i > 0 && (ff[i] == NULL || !ff[i]->ff_allocated)) 287 i--; 288 289 return i; 290 } 291 292 static inline void 293 fd_used(filedesc_t *fdp, unsigned fd) 294 { 295 u_int off = fd >> NDENTRYSHIFT; 296 fdfile_t *ff; 297 298 ff = fdp->fd_dt->dt_ff[fd]; 299 300 KASSERT(mutex_owned(&fdp->fd_lock)); 301 KASSERT((fdp->fd_lomap[off] & (1U << (fd & NDENTRYMASK))) == 0); 302 KASSERT(ff != NULL); 303 KASSERT(ff->ff_file == NULL); 304 KASSERT(!ff->ff_allocated); 305 306 ff->ff_allocated = true; 307 fdp->fd_lomap[off] |= 1U << (fd & NDENTRYMASK); 308 if (__predict_false(fdp->fd_lomap[off] == ~0)) { 309 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 310 (1U << (off & NDENTRYMASK))) == 0); 311 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1U << (off & NDENTRYMASK); 312 } 313 314 if ((int)fd > fdp->fd_lastfile) { 315 fdp->fd_lastfile = fd; 316 } 317 318 fd_checkmaps(fdp); 319 } 320 321 static inline void 322 fd_unused(filedesc_t *fdp, unsigned fd) 323 { 324 u_int off = fd >> NDENTRYSHIFT; 325 fdfile_t *ff; 326 327 ff = fdp->fd_dt->dt_ff[fd]; 328 329 KASSERT(mutex_owned(&fdp->fd_lock)); 330 KASSERT(ff != NULL); 331 KASSERT(ff->ff_file == NULL); 332 KASSERT(ff->ff_allocated); 333 334 if (fd < fdp->fd_freefile) { 335 fdp->fd_freefile = fd; 336 } 337 338 if (fdp->fd_lomap[off] == ~0) { 339 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 340 (1U << (off & NDENTRYMASK))) != 0); 341 fdp->fd_himap[off >> NDENTRYSHIFT] &= 342 ~(1U << (off & NDENTRYMASK)); 343 } 344 KASSERT((fdp->fd_lomap[off] & (1U << (fd & NDENTRYMASK))) != 0); 345 fdp->fd_lomap[off] &= ~(1U << (fd & NDENTRYMASK)); 346 ff->ff_allocated = false; 347 348 KASSERT(fd <= fdp->fd_lastfile); 349 if (fd == fdp->fd_lastfile) { 350 fdp->fd_lastfile = fd_last_set(fdp, fd); 351 } 352 fd_checkmaps(fdp); 353 } 354 355 /* 356 * Look up the file structure corresponding to a file descriptor 357 * and return the file, holding a reference on the descriptor. 358 */ 359 file_t * 360 fd_getfile(unsigned fd) 361 { 362 filedesc_t *fdp; 363 fdfile_t *ff; 364 file_t *fp; 365 fdtab_t *dt; 366 367 /* 368 * Look up the fdfile structure representing this descriptor. 369 * We are doing this unlocked. See fd_tryexpand(). 370 */ 371 fdp = curlwp->l_fd; 372 dt = atomic_load_consume(&fdp->fd_dt); 373 if (__predict_false(fd >= dt->dt_nfiles)) { 374 return NULL; 375 } 376 ff = dt->dt_ff[fd]; 377 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 378 if (__predict_false(ff == NULL)) { 379 return NULL; 380 } 381 382 /* Now get a reference to the descriptor. */ 383 if (fdp->fd_refcnt == 1) { 384 /* 385 * Single threaded: don't need to worry about concurrent 386 * access (other than earlier calls to kqueue, which may 387 * hold a reference to the descriptor). 388 */ 389 ff->ff_refcnt++; 390 } else { 391 /* 392 * Multi threaded: issue a memory barrier to ensure that we 393 * acquire the file pointer _after_ adding a reference. If 394 * no memory barrier, we could fetch a stale pointer. 395 */ 396 atomic_inc_uint(&ff->ff_refcnt); 397 #ifndef __HAVE_ATOMIC_AS_MEMBAR 398 membar_enter(); 399 #endif 400 } 401 402 /* 403 * If the file is not open or is being closed then put the 404 * reference back. 405 */ 406 fp = atomic_load_consume(&ff->ff_file); 407 if (__predict_true(fp != NULL)) { 408 return fp; 409 } 410 fd_putfile(fd); 411 return NULL; 412 } 413 414 /* 415 * Release a reference to a file descriptor acquired with fd_getfile(). 416 */ 417 void 418 fd_putfile(unsigned fd) 419 { 420 filedesc_t *fdp; 421 fdfile_t *ff; 422 u_int u, v; 423 424 fdp = curlwp->l_fd; 425 KASSERT(fd < atomic_load_consume(&fdp->fd_dt)->dt_nfiles); 426 ff = atomic_load_consume(&fdp->fd_dt)->dt_ff[fd]; 427 428 KASSERT(ff != NULL); 429 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 430 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 431 432 if (fdp->fd_refcnt == 1) { 433 /* 434 * Single threaded: don't need to worry about concurrent 435 * access (other than earlier calls to kqueue, which may 436 * hold a reference to the descriptor). 437 */ 438 if (__predict_false((ff->ff_refcnt & FR_CLOSING) != 0)) { 439 fd_close(fd); 440 return; 441 } 442 ff->ff_refcnt--; 443 return; 444 } 445 446 /* 447 * Ensure that any use of the file is complete and globally 448 * visible before dropping the final reference. If no membar, 449 * the current CPU could still access memory associated with 450 * the file after it has been freed or recycled by another 451 * CPU. 452 */ 453 #ifndef __HAVE_ATOMIC_AS_MEMBAR 454 membar_exit(); 455 #endif 456 457 /* 458 * Be optimistic and start out with the assumption that no other 459 * threads are trying to close the descriptor. If the CAS fails, 460 * we lost a race and/or it's being closed. 461 */ 462 for (u = ff->ff_refcnt & FR_MASK;; u = v) { 463 v = atomic_cas_uint(&ff->ff_refcnt, u, u - 1); 464 if (__predict_true(u == v)) { 465 return; 466 } 467 if (__predict_false((v & FR_CLOSING) != 0)) { 468 break; 469 } 470 } 471 472 /* Another thread is waiting to close the file: join it. */ 473 (void)fd_close(fd); 474 } 475 476 /* 477 * Convenience wrapper around fd_getfile() that returns reference 478 * to a vnode. 479 */ 480 int 481 fd_getvnode(unsigned fd, file_t **fpp) 482 { 483 vnode_t *vp; 484 file_t *fp; 485 486 fp = fd_getfile(fd); 487 if (__predict_false(fp == NULL)) { 488 return EBADF; 489 } 490 if (__predict_false(fp->f_type != DTYPE_VNODE)) { 491 fd_putfile(fd); 492 return EINVAL; 493 } 494 vp = fp->f_vnode; 495 if (__predict_false(vp->v_type == VBAD)) { 496 /* XXX Is this case really necessary? */ 497 fd_putfile(fd); 498 return EBADF; 499 } 500 *fpp = fp; 501 return 0; 502 } 503 504 /* 505 * Convenience wrapper around fd_getfile() that returns reference 506 * to a socket. 507 */ 508 int 509 fd_getsock1(unsigned fd, struct socket **sop, file_t **fp) 510 { 511 *fp = fd_getfile(fd); 512 if (__predict_false(*fp == NULL)) { 513 return EBADF; 514 } 515 if (__predict_false((*fp)->f_type != DTYPE_SOCKET)) { 516 fd_putfile(fd); 517 return ENOTSOCK; 518 } 519 *sop = (*fp)->f_socket; 520 return 0; 521 } 522 523 int 524 fd_getsock(unsigned fd, struct socket **sop) 525 { 526 file_t *fp; 527 return fd_getsock1(fd, sop, &fp); 528 } 529 530 /* 531 * Look up the file structure corresponding to a file descriptor 532 * and return it with a reference held on the file, not the 533 * descriptor. 534 * 535 * This is heavyweight and only used when accessing descriptors 536 * from a foreign process. The caller must ensure that `p' does 537 * not exit or fork across this call. 538 * 539 * To release the file (not descriptor) reference, use closef(). 540 */ 541 file_t * 542 fd_getfile2(proc_t *p, unsigned fd) 543 { 544 filedesc_t *fdp; 545 fdfile_t *ff; 546 file_t *fp; 547 fdtab_t *dt; 548 549 fdp = p->p_fd; 550 mutex_enter(&fdp->fd_lock); 551 dt = fdp->fd_dt; 552 if (fd >= dt->dt_nfiles) { 553 mutex_exit(&fdp->fd_lock); 554 return NULL; 555 } 556 if ((ff = dt->dt_ff[fd]) == NULL) { 557 mutex_exit(&fdp->fd_lock); 558 return NULL; 559 } 560 if ((fp = atomic_load_consume(&ff->ff_file)) == NULL) { 561 mutex_exit(&fdp->fd_lock); 562 return NULL; 563 } 564 mutex_enter(&fp->f_lock); 565 fp->f_count++; 566 mutex_exit(&fp->f_lock); 567 mutex_exit(&fdp->fd_lock); 568 569 return fp; 570 } 571 572 /* 573 * Internal form of close. Must be called with a reference to the 574 * descriptor, and will drop the reference. When all descriptor 575 * references are dropped, releases the descriptor slot and a single 576 * reference to the file structure. 577 */ 578 int 579 fd_close(unsigned fd) 580 { 581 struct flock lf; 582 filedesc_t *fdp; 583 fdfile_t *ff; 584 file_t *fp; 585 proc_t *p; 586 lwp_t *l; 587 u_int refcnt; 588 589 l = curlwp; 590 p = l->l_proc; 591 fdp = l->l_fd; 592 ff = atomic_load_consume(&fdp->fd_dt)->dt_ff[fd]; 593 594 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 595 596 mutex_enter(&fdp->fd_lock); 597 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 598 fp = atomic_load_consume(&ff->ff_file); 599 if (__predict_false(fp == NULL)) { 600 /* 601 * Another user of the file is already closing, and is 602 * waiting for other users of the file to drain. Release 603 * our reference, and wake up the closer. 604 */ 605 atomic_dec_uint(&ff->ff_refcnt); 606 cv_broadcast(&ff->ff_closing); 607 mutex_exit(&fdp->fd_lock); 608 609 /* 610 * An application error, so pretend that the descriptor 611 * was already closed. We can't safely wait for it to 612 * be closed without potentially deadlocking. 613 */ 614 return (EBADF); 615 } 616 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 617 618 /* 619 * There may be multiple users of this file within the process. 620 * Notify existing and new users that the file is closing. This 621 * will prevent them from adding additional uses to this file 622 * while we are closing it. 623 */ 624 ff->ff_file = NULL; 625 ff->ff_exclose = false; 626 627 /* 628 * We expect the caller to hold a descriptor reference - drop it. 629 * The reference count may increase beyond zero at this point due 630 * to an erroneous descriptor reference by an application, but 631 * fd_getfile() will notice that the file is being closed and drop 632 * the reference again. 633 */ 634 if (fdp->fd_refcnt == 1) { 635 /* Single threaded. */ 636 refcnt = --(ff->ff_refcnt); 637 } else { 638 /* Multi threaded. */ 639 #ifndef __HAVE_ATOMIC_AS_MEMBAR 640 membar_producer(); 641 #endif 642 refcnt = atomic_dec_uint_nv(&ff->ff_refcnt); 643 } 644 if (__predict_false(refcnt != 0)) { 645 /* 646 * Wait for other references to drain. This is typically 647 * an application error - the descriptor is being closed 648 * while still in use. 649 * (Or just a threaded application trying to unblock its 650 * thread that sleeps in (say) accept()). 651 */ 652 atomic_or_uint(&ff->ff_refcnt, FR_CLOSING); 653 654 /* 655 * Remove any knotes attached to the file. A knote 656 * attached to the descriptor can hold references on it. 657 */ 658 mutex_exit(&fdp->fd_lock); 659 if (!SLIST_EMPTY(&ff->ff_knlist)) { 660 knote_fdclose(fd); 661 } 662 663 /* 664 * Since the file system code doesn't know which fd 665 * each request came from (think dup()), we have to 666 * ask it to return ERESTART for any long-term blocks. 667 * The re-entry through read/write/etc will detect the 668 * closed fd and return EBAFD. 669 * Blocked partial writes may return a short length. 670 */ 671 (*fp->f_ops->fo_restart)(fp); 672 mutex_enter(&fdp->fd_lock); 673 674 /* 675 * We need to see the count drop to zero at least once, 676 * in order to ensure that all pre-existing references 677 * have been drained. New references past this point are 678 * of no interest. 679 * XXX (dsl) this may need to call fo_restart() after a 680 * timeout to guarantee that all the system calls exit. 681 */ 682 while ((ff->ff_refcnt & FR_MASK) != 0) { 683 cv_wait(&ff->ff_closing, &fdp->fd_lock); 684 } 685 atomic_and_uint(&ff->ff_refcnt, ~FR_CLOSING); 686 } else { 687 /* If no references, there must be no knotes. */ 688 KASSERT(SLIST_EMPTY(&ff->ff_knlist)); 689 } 690 691 /* 692 * POSIX record locking dictates that any close releases ALL 693 * locks owned by this process. This is handled by setting 694 * a flag in the unlock to free ONLY locks obeying POSIX 695 * semantics, and not to free BSD-style file locks. 696 * If the descriptor was in a message, POSIX-style locks 697 * aren't passed with the descriptor. 698 */ 699 if (__predict_false((p->p_flag & PK_ADVLOCK) != 0 && 700 fp->f_type == DTYPE_VNODE)) { 701 lf.l_whence = SEEK_SET; 702 lf.l_start = 0; 703 lf.l_len = 0; 704 lf.l_type = F_UNLCK; 705 mutex_exit(&fdp->fd_lock); 706 (void)VOP_ADVLOCK(fp->f_vnode, p, F_UNLCK, &lf, F_POSIX); 707 mutex_enter(&fdp->fd_lock); 708 } 709 710 /* Free descriptor slot. */ 711 fd_unused(fdp, fd); 712 mutex_exit(&fdp->fd_lock); 713 714 /* Now drop reference to the file itself. */ 715 return closef(fp); 716 } 717 718 /* 719 * Duplicate a file descriptor. 720 */ 721 int 722 fd_dup(file_t *fp, int minfd, int *newp, bool exclose) 723 { 724 proc_t *p = curproc; 725 fdtab_t *dt; 726 int error; 727 728 while ((error = fd_alloc(p, minfd, newp)) != 0) { 729 if (error != ENOSPC) { 730 return error; 731 } 732 fd_tryexpand(p); 733 } 734 735 dt = atomic_load_consume(&curlwp->l_fd->fd_dt); 736 dt->dt_ff[*newp]->ff_exclose = exclose; 737 fd_affix(p, fp, *newp); 738 return 0; 739 } 740 741 /* 742 * dup2 operation. 743 */ 744 int 745 fd_dup2(file_t *fp, unsigned newfd, int flags) 746 { 747 filedesc_t *fdp = curlwp->l_fd; 748 fdfile_t *ff; 749 fdtab_t *dt; 750 751 if (flags & ~(O_CLOEXEC|O_NONBLOCK|O_NOSIGPIPE)) 752 return EINVAL; 753 /* 754 * Ensure there are enough slots in the descriptor table, 755 * and allocate an fdfile_t up front in case we need it. 756 */ 757 while (newfd >= atomic_load_consume(&fdp->fd_dt)->dt_nfiles) { 758 fd_tryexpand(curproc); 759 } 760 ff = pool_cache_get(fdfile_cache, PR_WAITOK); 761 762 /* 763 * If there is already a file open, close it. If the file is 764 * half open, wait for it to be constructed before closing it. 765 * XXX Potential for deadlock here? 766 */ 767 mutex_enter(&fdp->fd_lock); 768 while (fd_isused(fdp, newfd)) { 769 mutex_exit(&fdp->fd_lock); 770 if (fd_getfile(newfd) != NULL) { 771 (void)fd_close(newfd); 772 } else { 773 /* 774 * Crummy, but unlikely to happen. 775 * Can occur if we interrupt another 776 * thread while it is opening a file. 777 */ 778 kpause("dup2", false, 1, NULL); 779 } 780 mutex_enter(&fdp->fd_lock); 781 } 782 dt = fdp->fd_dt; 783 if (dt->dt_ff[newfd] == NULL) { 784 KASSERT(newfd >= NDFDFILE); 785 dt->dt_ff[newfd] = ff; 786 ff = NULL; 787 } 788 fd_used(fdp, newfd); 789 mutex_exit(&fdp->fd_lock); 790 791 dt->dt_ff[newfd]->ff_exclose = (flags & O_CLOEXEC) != 0; 792 fp->f_flag |= flags & (FNONBLOCK|FNOSIGPIPE); 793 /* Slot is now allocated. Insert copy of the file. */ 794 fd_affix(curproc, fp, newfd); 795 if (ff != NULL) { 796 pool_cache_put(fdfile_cache, ff); 797 } 798 return 0; 799 } 800 801 /* 802 * Drop reference to a file structure. 803 */ 804 int 805 closef(file_t *fp) 806 { 807 struct flock lf; 808 int error; 809 810 /* 811 * Drop reference. If referenced elsewhere it's still open 812 * and we have nothing more to do. 813 */ 814 mutex_enter(&fp->f_lock); 815 KASSERT(fp->f_count > 0); 816 if (--fp->f_count > 0) { 817 mutex_exit(&fp->f_lock); 818 return 0; 819 } 820 KASSERT(fp->f_count == 0); 821 mutex_exit(&fp->f_lock); 822 823 /* We held the last reference - release locks, close and free. */ 824 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 825 lf.l_whence = SEEK_SET; 826 lf.l_start = 0; 827 lf.l_len = 0; 828 lf.l_type = F_UNLCK; 829 (void)VOP_ADVLOCK(fp->f_vnode, fp, F_UNLCK, &lf, F_FLOCK); 830 } 831 if (fp->f_ops != NULL) { 832 error = (*fp->f_ops->fo_close)(fp); 833 } else { 834 error = 0; 835 } 836 KASSERT(fp->f_count == 0); 837 KASSERT(fp->f_cred != NULL); 838 pool_cache_put(file_cache, fp); 839 840 return error; 841 } 842 843 /* 844 * Allocate a file descriptor for the process. 845 */ 846 int 847 fd_alloc(proc_t *p, int want, int *result) 848 { 849 filedesc_t *fdp = p->p_fd; 850 int i, lim, last, error, hi; 851 u_int off; 852 fdtab_t *dt; 853 854 KASSERT(p == curproc || p == &proc0); 855 856 /* 857 * Search for a free descriptor starting at the higher 858 * of want or fd_freefile. 859 */ 860 mutex_enter(&fdp->fd_lock); 861 fd_checkmaps(fdp); 862 dt = fdp->fd_dt; 863 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 864 lim = uimin((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 865 last = uimin(dt->dt_nfiles, lim); 866 for (;;) { 867 if ((i = want) < fdp->fd_freefile) 868 i = fdp->fd_freefile; 869 off = i >> NDENTRYSHIFT; 870 hi = fd_next_zero(fdp, fdp->fd_himap, off, 871 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 872 if (hi == -1) 873 break; 874 i = fd_next_zero(fdp, &fdp->fd_lomap[hi], 875 hi > off ? 0 : i & NDENTRYMASK, NDENTRIES); 876 if (i == -1) { 877 /* 878 * Free file descriptor in this block was 879 * below want, try again with higher want. 880 */ 881 want = (hi + 1) << NDENTRYSHIFT; 882 continue; 883 } 884 i += (hi << NDENTRYSHIFT); 885 if (i >= last) { 886 break; 887 } 888 if (dt->dt_ff[i] == NULL) { 889 KASSERT(i >= NDFDFILE); 890 dt->dt_ff[i] = pool_cache_get(fdfile_cache, PR_WAITOK); 891 } 892 KASSERT(dt->dt_ff[i]->ff_file == NULL); 893 fd_used(fdp, i); 894 if (want <= fdp->fd_freefile) { 895 fdp->fd_freefile = i; 896 } 897 *result = i; 898 KASSERT(i >= NDFDFILE || 899 dt->dt_ff[i] == (fdfile_t *)fdp->fd_dfdfile[i]); 900 fd_checkmaps(fdp); 901 mutex_exit(&fdp->fd_lock); 902 return 0; 903 } 904 905 /* No space in current array. Let the caller expand and retry. */ 906 error = (dt->dt_nfiles >= lim) ? EMFILE : ENOSPC; 907 mutex_exit(&fdp->fd_lock); 908 return error; 909 } 910 911 /* 912 * Allocate memory for a descriptor table. 913 */ 914 static fdtab_t * 915 fd_dtab_alloc(int n) 916 { 917 fdtab_t *dt; 918 size_t sz; 919 920 KASSERT(n > NDFILE); 921 922 sz = sizeof(*dt) + (n - NDFILE) * sizeof(dt->dt_ff[0]); 923 dt = kmem_alloc(sz, KM_SLEEP); 924 #ifdef DIAGNOSTIC 925 memset(dt, 0xff, sz); 926 #endif 927 dt->dt_nfiles = n; 928 dt->dt_link = NULL; 929 return dt; 930 } 931 932 /* 933 * Free a descriptor table, and all tables linked for deferred free. 934 */ 935 static void 936 fd_dtab_free(fdtab_t *dt) 937 { 938 fdtab_t *next; 939 size_t sz; 940 941 do { 942 next = dt->dt_link; 943 KASSERT(dt->dt_nfiles > NDFILE); 944 sz = sizeof(*dt) + 945 (dt->dt_nfiles - NDFILE) * sizeof(dt->dt_ff[0]); 946 #ifdef DIAGNOSTIC 947 memset(dt, 0xff, sz); 948 #endif 949 kmem_free(dt, sz); 950 dt = next; 951 } while (dt != NULL); 952 } 953 954 /* 955 * Allocate descriptor bitmap. 956 */ 957 static void 958 fd_map_alloc(int n, uint32_t **lo, uint32_t **hi) 959 { 960 uint8_t *ptr; 961 size_t szlo, szhi; 962 963 KASSERT(n > NDENTRIES); 964 965 szlo = NDLOSLOTS(n) * sizeof(uint32_t); 966 szhi = NDHISLOTS(n) * sizeof(uint32_t); 967 ptr = kmem_alloc(szlo + szhi, KM_SLEEP); 968 *lo = (uint32_t *)ptr; 969 *hi = (uint32_t *)(ptr + szlo); 970 } 971 972 /* 973 * Free descriptor bitmap. 974 */ 975 static void 976 fd_map_free(int n, uint32_t *lo, uint32_t *hi) 977 { 978 size_t szlo, szhi; 979 980 KASSERT(n > NDENTRIES); 981 982 szlo = NDLOSLOTS(n) * sizeof(uint32_t); 983 szhi = NDHISLOTS(n) * sizeof(uint32_t); 984 KASSERT(hi == (uint32_t *)((uint8_t *)lo + szlo)); 985 kmem_free(lo, szlo + szhi); 986 } 987 988 /* 989 * Expand a process' descriptor table. 990 */ 991 void 992 fd_tryexpand(proc_t *p) 993 { 994 filedesc_t *fdp; 995 int i, numfiles, oldnfiles; 996 fdtab_t *newdt, *dt; 997 uint32_t *newhimap, *newlomap; 998 999 KASSERT(p == curproc || p == &proc0); 1000 1001 fdp = p->p_fd; 1002 newhimap = NULL; 1003 newlomap = NULL; 1004 oldnfiles = atomic_load_consume(&fdp->fd_dt)->dt_nfiles; 1005 1006 if (oldnfiles < NDEXTENT) 1007 numfiles = NDEXTENT; 1008 else 1009 numfiles = 2 * oldnfiles; 1010 1011 newdt = fd_dtab_alloc(numfiles); 1012 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1013 fd_map_alloc(numfiles, &newlomap, &newhimap); 1014 } 1015 1016 mutex_enter(&fdp->fd_lock); 1017 dt = fdp->fd_dt; 1018 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1019 if (dt->dt_nfiles != oldnfiles) { 1020 /* fdp changed; caller must retry */ 1021 mutex_exit(&fdp->fd_lock); 1022 fd_dtab_free(newdt); 1023 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1024 fd_map_free(numfiles, newlomap, newhimap); 1025 } 1026 return; 1027 } 1028 1029 /* Copy the existing descriptor table and zero the new portion. */ 1030 i = sizeof(fdfile_t *) * oldnfiles; 1031 memcpy(newdt->dt_ff, dt->dt_ff, i); 1032 memset((uint8_t *)newdt->dt_ff + i, 0, 1033 numfiles * sizeof(fdfile_t *) - i); 1034 1035 /* 1036 * Link old descriptor array into list to be discarded. We defer 1037 * freeing until the last reference to the descriptor table goes 1038 * away (usually process exit). This allows us to do lockless 1039 * lookups in fd_getfile(). 1040 */ 1041 if (oldnfiles > NDFILE) { 1042 if (fdp->fd_refcnt > 1) { 1043 newdt->dt_link = dt; 1044 } else { 1045 fd_dtab_free(dt); 1046 } 1047 } 1048 1049 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1050 i = NDHISLOTS(oldnfiles) * sizeof(uint32_t); 1051 memcpy(newhimap, fdp->fd_himap, i); 1052 memset((uint8_t *)newhimap + i, 0, 1053 NDHISLOTS(numfiles) * sizeof(uint32_t) - i); 1054 1055 i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t); 1056 memcpy(newlomap, fdp->fd_lomap, i); 1057 memset((uint8_t *)newlomap + i, 0, 1058 NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); 1059 1060 if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { 1061 fd_map_free(oldnfiles, fdp->fd_lomap, fdp->fd_himap); 1062 } 1063 fdp->fd_himap = newhimap; 1064 fdp->fd_lomap = newlomap; 1065 } 1066 1067 /* 1068 * All other modifications must become globally visible before 1069 * the change to fd_dt. See fd_getfile(). 1070 */ 1071 atomic_store_release(&fdp->fd_dt, newdt); 1072 KASSERT(newdt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1073 fd_checkmaps(fdp); 1074 mutex_exit(&fdp->fd_lock); 1075 } 1076 1077 /* 1078 * Create a new open file structure and allocate a file descriptor 1079 * for the current process. 1080 */ 1081 int 1082 fd_allocfile(file_t **resultfp, int *resultfd) 1083 { 1084 proc_t *p = curproc; 1085 kauth_cred_t cred; 1086 file_t *fp; 1087 int error; 1088 1089 while ((error = fd_alloc(p, 0, resultfd)) != 0) { 1090 if (error != ENOSPC) { 1091 return error; 1092 } 1093 fd_tryexpand(p); 1094 } 1095 1096 fp = pool_cache_get(file_cache, PR_WAITOK); 1097 if (fp == NULL) { 1098 fd_abort(p, NULL, *resultfd); 1099 return ENFILE; 1100 } 1101 KASSERT(fp->f_count == 0); 1102 KASSERT(fp->f_msgcount == 0); 1103 KASSERT(fp->f_unpcount == 0); 1104 1105 /* Replace cached credentials if not what we need. */ 1106 cred = curlwp->l_cred; 1107 if (__predict_false(cred != fp->f_cred)) { 1108 kauth_cred_free(fp->f_cred); 1109 kauth_cred_hold(cred); 1110 fp->f_cred = cred; 1111 } 1112 1113 /* 1114 * Don't allow recycled files to be scanned. 1115 * See uipc_usrreq.c. 1116 */ 1117 if (__predict_false((fp->f_flag & FSCAN) != 0)) { 1118 mutex_enter(&fp->f_lock); 1119 atomic_and_uint(&fp->f_flag, ~FSCAN); 1120 mutex_exit(&fp->f_lock); 1121 } 1122 1123 fp->f_advice = 0; 1124 fp->f_offset = 0; 1125 *resultfp = fp; 1126 1127 return 0; 1128 } 1129 1130 /* 1131 * Successful creation of a new descriptor: make visible to the process. 1132 */ 1133 void 1134 fd_affix(proc_t *p, file_t *fp, unsigned fd) 1135 { 1136 fdfile_t *ff; 1137 filedesc_t *fdp; 1138 fdtab_t *dt; 1139 1140 KASSERT(p == curproc || p == &proc0); 1141 1142 /* Add a reference to the file structure. */ 1143 mutex_enter(&fp->f_lock); 1144 fp->f_count++; 1145 mutex_exit(&fp->f_lock); 1146 1147 /* 1148 * Insert the new file into the descriptor slot. 1149 * 1150 * The memory barriers provided by lock activity in this routine 1151 * ensure that any updates to the file structure become globally 1152 * visible before the file becomes visible to other LWPs in the 1153 * current process; otherwise we would set ff->ff_file with 1154 * atomic_store_release(&ff->ff_file, fp) at the bottom. 1155 */ 1156 fdp = p->p_fd; 1157 dt = atomic_load_consume(&fdp->fd_dt); 1158 ff = dt->dt_ff[fd]; 1159 1160 KASSERT(ff != NULL); 1161 KASSERT(ff->ff_file == NULL); 1162 KASSERT(ff->ff_allocated); 1163 KASSERT(fd_isused(fdp, fd)); 1164 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1165 1166 /* No need to lock in order to make file initially visible. */ 1167 ff->ff_file = fp; 1168 } 1169 1170 /* 1171 * Abort creation of a new descriptor: free descriptor slot and file. 1172 */ 1173 void 1174 fd_abort(proc_t *p, file_t *fp, unsigned fd) 1175 { 1176 filedesc_t *fdp; 1177 fdfile_t *ff; 1178 1179 KASSERT(p == curproc || p == &proc0); 1180 1181 fdp = p->p_fd; 1182 ff = atomic_load_consume(&fdp->fd_dt)->dt_ff[fd]; 1183 ff->ff_exclose = false; 1184 1185 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1186 1187 mutex_enter(&fdp->fd_lock); 1188 KASSERT(fd_isused(fdp, fd)); 1189 fd_unused(fdp, fd); 1190 mutex_exit(&fdp->fd_lock); 1191 1192 if (fp != NULL) { 1193 KASSERT(fp->f_count == 0); 1194 KASSERT(fp->f_cred != NULL); 1195 pool_cache_put(file_cache, fp); 1196 } 1197 } 1198 1199 static int 1200 file_ctor(void *arg, void *obj, int flags) 1201 { 1202 file_t *fp = obj; 1203 1204 memset(fp, 0, sizeof(*fp)); 1205 1206 mutex_enter(&filelist_lock); 1207 if (__predict_false(nfiles >= maxfiles)) { 1208 mutex_exit(&filelist_lock); 1209 tablefull("file", "increase kern.maxfiles or MAXFILES"); 1210 return ENFILE; 1211 } 1212 nfiles++; 1213 LIST_INSERT_HEAD(&filehead, fp, f_list); 1214 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1215 fp->f_cred = curlwp->l_cred; 1216 kauth_cred_hold(fp->f_cred); 1217 mutex_exit(&filelist_lock); 1218 1219 return 0; 1220 } 1221 1222 static void 1223 file_dtor(void *arg, void *obj) 1224 { 1225 file_t *fp = obj; 1226 1227 mutex_enter(&filelist_lock); 1228 nfiles--; 1229 LIST_REMOVE(fp, f_list); 1230 mutex_exit(&filelist_lock); 1231 1232 KASSERT(fp->f_count == 0); 1233 kauth_cred_free(fp->f_cred); 1234 mutex_destroy(&fp->f_lock); 1235 } 1236 1237 static int 1238 fdfile_ctor(void *arg, void *obj, int flags) 1239 { 1240 fdfile_t *ff = obj; 1241 1242 memset(ff, 0, sizeof(*ff)); 1243 cv_init(&ff->ff_closing, "fdclose"); 1244 1245 return 0; 1246 } 1247 1248 static void 1249 fdfile_dtor(void *arg, void *obj) 1250 { 1251 fdfile_t *ff = obj; 1252 1253 cv_destroy(&ff->ff_closing); 1254 } 1255 1256 file_t * 1257 fgetdummy(void) 1258 { 1259 file_t *fp; 1260 1261 fp = kmem_zalloc(sizeof(*fp), KM_SLEEP); 1262 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1263 return fp; 1264 } 1265 1266 void 1267 fputdummy(file_t *fp) 1268 { 1269 1270 mutex_destroy(&fp->f_lock); 1271 kmem_free(fp, sizeof(*fp)); 1272 } 1273 1274 /* 1275 * Create an initial filedesc structure. 1276 */ 1277 filedesc_t * 1278 fd_init(filedesc_t *fdp) 1279 { 1280 #ifdef DIAGNOSTIC 1281 unsigned fd; 1282 #endif 1283 1284 if (__predict_true(fdp == NULL)) { 1285 fdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1286 } else { 1287 KASSERT(fdp == &filedesc0); 1288 filedesc_ctor(NULL, fdp, PR_WAITOK); 1289 } 1290 1291 #ifdef DIAGNOSTIC 1292 KASSERT(fdp->fd_lastfile == -1); 1293 KASSERT(fdp->fd_lastkqfile == -1); 1294 KASSERT(fdp->fd_knhash == NULL); 1295 KASSERT(fdp->fd_freefile == 0); 1296 KASSERT(fdp->fd_exclose == false); 1297 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1298 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1299 for (fd = 0; fd < NDFDFILE; fd++) { 1300 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == 1301 (fdfile_t *)fdp->fd_dfdfile[fd]); 1302 } 1303 for (fd = NDFDFILE; fd < NDFILE; fd++) { 1304 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == NULL); 1305 } 1306 KASSERT(fdp->fd_himap == fdp->fd_dhimap); 1307 KASSERT(fdp->fd_lomap == fdp->fd_dlomap); 1308 #endif /* DIAGNOSTIC */ 1309 1310 fdp->fd_refcnt = 1; 1311 fd_checkmaps(fdp); 1312 1313 return fdp; 1314 } 1315 1316 /* 1317 * Initialize a file descriptor table. 1318 */ 1319 static int 1320 filedesc_ctor(void *arg, void *obj, int flag) 1321 { 1322 filedesc_t *fdp = obj; 1323 fdfile_t **ffp; 1324 int i; 1325 1326 memset(fdp, 0, sizeof(*fdp)); 1327 mutex_init(&fdp->fd_lock, MUTEX_DEFAULT, IPL_NONE); 1328 fdp->fd_lastfile = -1; 1329 fdp->fd_lastkqfile = -1; 1330 fdp->fd_dt = &fdp->fd_dtbuiltin; 1331 fdp->fd_dtbuiltin.dt_nfiles = NDFILE; 1332 fdp->fd_himap = fdp->fd_dhimap; 1333 fdp->fd_lomap = fdp->fd_dlomap; 1334 1335 CTASSERT(sizeof(fdp->fd_dfdfile[0]) >= sizeof(fdfile_t)); 1336 for (i = 0, ffp = fdp->fd_dt->dt_ff; i < NDFDFILE; i++, ffp++) { 1337 *ffp = (fdfile_t *)fdp->fd_dfdfile[i]; 1338 (void)fdfile_ctor(NULL, fdp->fd_dfdfile[i], PR_WAITOK); 1339 } 1340 1341 return 0; 1342 } 1343 1344 static void 1345 filedesc_dtor(void *arg, void *obj) 1346 { 1347 filedesc_t *fdp = obj; 1348 int i; 1349 1350 for (i = 0; i < NDFDFILE; i++) { 1351 fdfile_dtor(NULL, fdp->fd_dfdfile[i]); 1352 } 1353 1354 mutex_destroy(&fdp->fd_lock); 1355 } 1356 1357 /* 1358 * Make p share curproc's filedesc structure. 1359 */ 1360 void 1361 fd_share(struct proc *p) 1362 { 1363 filedesc_t *fdp; 1364 1365 fdp = curlwp->l_fd; 1366 p->p_fd = fdp; 1367 atomic_inc_uint(&fdp->fd_refcnt); 1368 } 1369 1370 /* 1371 * Acquire a hold on a filedesc structure. 1372 */ 1373 void 1374 fd_hold(lwp_t *l) 1375 { 1376 filedesc_t *fdp = l->l_fd; 1377 1378 atomic_inc_uint(&fdp->fd_refcnt); 1379 } 1380 1381 /* 1382 * Copy a filedesc structure. 1383 */ 1384 filedesc_t * 1385 fd_copy(void) 1386 { 1387 filedesc_t *newfdp, *fdp; 1388 fdfile_t *ff, **ffp, **nffp, *ff2; 1389 int i, j, numfiles, lastfile, newlast; 1390 file_t *fp; 1391 fdtab_t *newdt; 1392 1393 fdp = curproc->p_fd; 1394 newfdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1395 newfdp->fd_refcnt = 1; 1396 1397 #ifdef DIAGNOSTIC 1398 KASSERT(newfdp->fd_lastfile == -1); 1399 KASSERT(newfdp->fd_lastkqfile == -1); 1400 KASSERT(newfdp->fd_knhash == NULL); 1401 KASSERT(newfdp->fd_freefile == 0); 1402 KASSERT(newfdp->fd_exclose == false); 1403 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1404 KASSERT(newfdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1405 for (i = 0; i < NDFDFILE; i++) { 1406 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == 1407 (fdfile_t *)&newfdp->fd_dfdfile[i]); 1408 } 1409 for (i = NDFDFILE; i < NDFILE; i++) { 1410 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == NULL); 1411 } 1412 #endif /* DIAGNOSTIC */ 1413 1414 mutex_enter(&fdp->fd_lock); 1415 fd_checkmaps(fdp); 1416 numfiles = fdp->fd_dt->dt_nfiles; 1417 lastfile = fdp->fd_lastfile; 1418 1419 /* 1420 * If the number of open files fits in the internal arrays 1421 * of the open file structure, use them, otherwise allocate 1422 * additional memory for the number of descriptors currently 1423 * in use. 1424 */ 1425 if (lastfile < NDFILE) { 1426 i = NDFILE; 1427 newdt = newfdp->fd_dt; 1428 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1429 } else { 1430 /* 1431 * Compute the smallest multiple of NDEXTENT needed 1432 * for the file descriptors currently in use, 1433 * allowing the table to shrink. 1434 */ 1435 i = numfiles; 1436 while (i >= 2 * NDEXTENT && i > lastfile * 2) { 1437 i /= 2; 1438 } 1439 KASSERT(i > NDFILE); 1440 newdt = fd_dtab_alloc(i); 1441 newfdp->fd_dt = newdt; 1442 memcpy(newdt->dt_ff, newfdp->fd_dtbuiltin.dt_ff, 1443 NDFDFILE * sizeof(fdfile_t **)); 1444 memset(newdt->dt_ff + NDFDFILE, 0, 1445 (i - NDFDFILE) * sizeof(fdfile_t **)); 1446 } 1447 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { 1448 newfdp->fd_himap = newfdp->fd_dhimap; 1449 newfdp->fd_lomap = newfdp->fd_dlomap; 1450 } else { 1451 fd_map_alloc(i, &newfdp->fd_lomap, &newfdp->fd_himap); 1452 KASSERT(i >= NDENTRIES * NDENTRIES); 1453 memset(newfdp->fd_himap, 0, NDHISLOTS(i)*sizeof(uint32_t)); 1454 memset(newfdp->fd_lomap, 0, NDLOSLOTS(i)*sizeof(uint32_t)); 1455 } 1456 newfdp->fd_freefile = fdp->fd_freefile; 1457 newfdp->fd_exclose = fdp->fd_exclose; 1458 1459 ffp = fdp->fd_dt->dt_ff; 1460 nffp = newdt->dt_ff; 1461 newlast = -1; 1462 for (i = 0; i <= lastfile; i++, ffp++, nffp++) { 1463 KASSERT(i >= NDFDFILE || 1464 *nffp == (fdfile_t *)newfdp->fd_dfdfile[i]); 1465 ff = *ffp; 1466 if (ff == NULL || 1467 (fp = atomic_load_consume(&ff->ff_file)) == NULL) { 1468 /* Descriptor unused, or descriptor half open. */ 1469 KASSERT(!fd_isused(newfdp, i)); 1470 continue; 1471 } 1472 if (__predict_false(fp->f_type == DTYPE_KQUEUE)) { 1473 /* kqueue descriptors cannot be copied. */ 1474 if (i < newfdp->fd_freefile) { 1475 newfdp->fd_freefile = i; 1476 } 1477 continue; 1478 } 1479 /* It's active: add a reference to the file. */ 1480 mutex_enter(&fp->f_lock); 1481 fp->f_count++; 1482 mutex_exit(&fp->f_lock); 1483 1484 /* Allocate an fdfile_t to represent it. */ 1485 if (i >= NDFDFILE) { 1486 ff2 = pool_cache_get(fdfile_cache, PR_WAITOK); 1487 *nffp = ff2; 1488 } else { 1489 ff2 = newdt->dt_ff[i]; 1490 } 1491 ff2->ff_file = fp; 1492 ff2->ff_exclose = ff->ff_exclose; 1493 ff2->ff_allocated = true; 1494 1495 /* Fix up bitmaps. */ 1496 j = i >> NDENTRYSHIFT; 1497 KASSERT((newfdp->fd_lomap[j] & (1U << (i & NDENTRYMASK))) == 0); 1498 newfdp->fd_lomap[j] |= 1U << (i & NDENTRYMASK); 1499 if (__predict_false(newfdp->fd_lomap[j] == ~0)) { 1500 KASSERT((newfdp->fd_himap[j >> NDENTRYSHIFT] & 1501 (1U << (j & NDENTRYMASK))) == 0); 1502 newfdp->fd_himap[j >> NDENTRYSHIFT] |= 1503 1U << (j & NDENTRYMASK); 1504 } 1505 newlast = i; 1506 } 1507 KASSERT(newdt->dt_ff[0] == (fdfile_t *)newfdp->fd_dfdfile[0]); 1508 newfdp->fd_lastfile = newlast; 1509 fd_checkmaps(newfdp); 1510 mutex_exit(&fdp->fd_lock); 1511 1512 return newfdp; 1513 } 1514 1515 /* 1516 * Release a filedesc structure. 1517 */ 1518 void 1519 fd_free(void) 1520 { 1521 fdfile_t *ff; 1522 file_t *fp; 1523 int fd, nf; 1524 fdtab_t *dt; 1525 lwp_t * const l = curlwp; 1526 filedesc_t * const fdp = l->l_fd; 1527 const bool noadvlock = (l->l_proc->p_flag & PK_ADVLOCK) == 0; 1528 1529 KASSERT(atomic_load_consume(&fdp->fd_dt)->dt_ff[0] == 1530 (fdfile_t *)fdp->fd_dfdfile[0]); 1531 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1532 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1533 1534 #ifndef __HAVE_ATOMIC_AS_MEMBAR 1535 membar_exit(); 1536 #endif 1537 if (atomic_dec_uint_nv(&fdp->fd_refcnt) > 0) 1538 return; 1539 1540 /* 1541 * Close any files that the process holds open. 1542 */ 1543 dt = fdp->fd_dt; 1544 fd_checkmaps(fdp); 1545 #ifdef DEBUG 1546 fdp->fd_refcnt = -1; /* see fd_checkmaps */ 1547 #endif 1548 for (fd = 0, nf = dt->dt_nfiles; fd < nf; fd++) { 1549 ff = dt->dt_ff[fd]; 1550 KASSERT(fd >= NDFDFILE || 1551 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1552 if (ff == NULL) 1553 continue; 1554 if ((fp = atomic_load_consume(&ff->ff_file)) != NULL) { 1555 /* 1556 * Must use fd_close() here if there is 1557 * a reference from kqueue or we might have posix 1558 * advisory locks. 1559 */ 1560 if (__predict_true(ff->ff_refcnt == 0) && 1561 (noadvlock || fp->f_type != DTYPE_VNODE)) { 1562 ff->ff_file = NULL; 1563 ff->ff_exclose = false; 1564 ff->ff_allocated = false; 1565 closef(fp); 1566 } else { 1567 ff->ff_refcnt++; 1568 fd_close(fd); 1569 } 1570 } 1571 KASSERT(ff->ff_refcnt == 0); 1572 KASSERT(ff->ff_file == NULL); 1573 KASSERT(!ff->ff_exclose); 1574 KASSERT(!ff->ff_allocated); 1575 if (fd >= NDFDFILE) { 1576 pool_cache_put(fdfile_cache, ff); 1577 dt->dt_ff[fd] = NULL; 1578 } 1579 } 1580 1581 /* 1582 * Clean out the descriptor table for the next user and return 1583 * to the cache. 1584 */ 1585 if (__predict_false(dt != &fdp->fd_dtbuiltin)) { 1586 fd_dtab_free(fdp->fd_dt); 1587 /* Otherwise, done above. */ 1588 memset(&fdp->fd_dtbuiltin.dt_ff[NDFDFILE], 0, 1589 (NDFILE - NDFDFILE) * sizeof(fdp->fd_dtbuiltin.dt_ff[0])); 1590 fdp->fd_dt = &fdp->fd_dtbuiltin; 1591 } 1592 if (__predict_false(NDHISLOTS(nf) > NDHISLOTS(NDFILE))) { 1593 KASSERT(fdp->fd_himap != fdp->fd_dhimap); 1594 KASSERT(fdp->fd_lomap != fdp->fd_dlomap); 1595 fd_map_free(nf, fdp->fd_lomap, fdp->fd_himap); 1596 } 1597 if (__predict_false(fdp->fd_knhash != NULL)) { 1598 hashdone(fdp->fd_knhash, HASH_LIST, fdp->fd_knhashmask); 1599 fdp->fd_knhash = NULL; 1600 fdp->fd_knhashmask = 0; 1601 } else { 1602 KASSERT(fdp->fd_knhashmask == 0); 1603 } 1604 fdp->fd_dt = &fdp->fd_dtbuiltin; 1605 fdp->fd_lastkqfile = -1; 1606 fdp->fd_lastfile = -1; 1607 fdp->fd_freefile = 0; 1608 fdp->fd_exclose = false; 1609 memset(&fdp->fd_startzero, 0, sizeof(*fdp) - 1610 offsetof(filedesc_t, fd_startzero)); 1611 fdp->fd_himap = fdp->fd_dhimap; 1612 fdp->fd_lomap = fdp->fd_dlomap; 1613 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1614 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1615 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1616 #ifdef DEBUG 1617 fdp->fd_refcnt = 0; /* see fd_checkmaps */ 1618 #endif 1619 fd_checkmaps(fdp); 1620 pool_cache_put(filedesc_cache, fdp); 1621 } 1622 1623 /* 1624 * File Descriptor pseudo-device driver (/dev/fd/). 1625 * 1626 * Opening minor device N dup()s the file (if any) connected to file 1627 * descriptor N belonging to the calling process. Note that this driver 1628 * consists of only the ``open()'' routine, because all subsequent 1629 * references to this file will be direct to the other driver. 1630 */ 1631 static int 1632 filedescopen(dev_t dev, int mode, int type, lwp_t *l) 1633 { 1634 1635 /* 1636 * XXX Kludge: set dupfd to contain the value of the 1637 * the file descriptor being sought for duplication. The error 1638 * return ensures that the vnode for this device will be released 1639 * by vn_open. Open will detect this special error and take the 1640 * actions in fd_dupopen below. Other callers of vn_open or VOP_OPEN 1641 * will simply report the error. 1642 */ 1643 l->l_dupfd = minor(dev); /* XXX */ 1644 return EDUPFD; 1645 } 1646 1647 /* 1648 * Duplicate the specified descriptor to a free descriptor. 1649 */ 1650 int 1651 fd_dupopen(int old, int *newp, int mode, int error) 1652 { 1653 filedesc_t *fdp; 1654 fdfile_t *ff; 1655 file_t *fp; 1656 fdtab_t *dt; 1657 1658 if ((fp = fd_getfile(old)) == NULL) { 1659 return EBADF; 1660 } 1661 fdp = curlwp->l_fd; 1662 dt = atomic_load_consume(&fdp->fd_dt); 1663 ff = dt->dt_ff[old]; 1664 1665 /* 1666 * There are two cases of interest here. 1667 * 1668 * For EDUPFD simply dup (old) to file descriptor 1669 * (new) and return. 1670 * 1671 * For EMOVEFD steal away the file structure from (old) and 1672 * store it in (new). (old) is effectively closed by 1673 * this operation. 1674 * 1675 * Any other error code is just returned. 1676 */ 1677 switch (error) { 1678 case EDUPFD: 1679 /* 1680 * Check that the mode the file is being opened for is a 1681 * subset of the mode of the existing descriptor. 1682 */ 1683 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 1684 error = EACCES; 1685 break; 1686 } 1687 1688 /* Copy it. */ 1689 error = fd_dup(fp, 0, newp, ff->ff_exclose); 1690 break; 1691 1692 case EMOVEFD: 1693 /* Copy it. */ 1694 error = fd_dup(fp, 0, newp, ff->ff_exclose); 1695 if (error != 0) { 1696 break; 1697 } 1698 1699 /* Steal away the file pointer from 'old'. */ 1700 (void)fd_close(old); 1701 return 0; 1702 } 1703 1704 fd_putfile(old); 1705 return error; 1706 } 1707 1708 /* 1709 * Close open files on exec. 1710 */ 1711 void 1712 fd_closeexec(void) 1713 { 1714 proc_t *p; 1715 filedesc_t *fdp; 1716 fdfile_t *ff; 1717 lwp_t *l; 1718 fdtab_t *dt; 1719 int fd; 1720 1721 l = curlwp; 1722 p = l->l_proc; 1723 fdp = p->p_fd; 1724 1725 if (fdp->fd_refcnt > 1) { 1726 fdp = fd_copy(); 1727 fd_free(); 1728 p->p_fd = fdp; 1729 l->l_fd = fdp; 1730 } 1731 if (!fdp->fd_exclose) { 1732 return; 1733 } 1734 fdp->fd_exclose = false; 1735 dt = atomic_load_consume(&fdp->fd_dt); 1736 1737 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 1738 if ((ff = dt->dt_ff[fd]) == NULL) { 1739 KASSERT(fd >= NDFDFILE); 1740 continue; 1741 } 1742 KASSERT(fd >= NDFDFILE || 1743 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1744 if (ff->ff_file == NULL) 1745 continue; 1746 if (ff->ff_exclose) { 1747 /* 1748 * We need a reference to close the file. 1749 * No other threads can see the fdfile_t at 1750 * this point, so don't bother locking. 1751 */ 1752 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 1753 ff->ff_refcnt++; 1754 fd_close(fd); 1755 } 1756 } 1757 } 1758 1759 /* 1760 * Sets descriptor owner. If the owner is a process, 'pgid' 1761 * is set to positive value, process ID. If the owner is process group, 1762 * 'pgid' is set to -pg_id. 1763 */ 1764 int 1765 fsetown(pid_t *pgid, u_long cmd, const void *data) 1766 { 1767 pid_t id = *(const pid_t *)data; 1768 int error; 1769 1770 switch (cmd) { 1771 case TIOCSPGRP: 1772 if (id < 0) 1773 return EINVAL; 1774 id = -id; 1775 break; 1776 default: 1777 break; 1778 } 1779 if (id > 0) { 1780 mutex_enter(&proc_lock); 1781 error = proc_find(id) ? 0 : ESRCH; 1782 mutex_exit(&proc_lock); 1783 } else if (id < 0) { 1784 error = pgid_in_session(curproc, -id); 1785 } else { 1786 error = 0; 1787 } 1788 if (!error) { 1789 *pgid = id; 1790 } 1791 return error; 1792 } 1793 1794 void 1795 fd_set_exclose(struct lwp *l, int fd, bool exclose) 1796 { 1797 filedesc_t *fdp = l->l_fd; 1798 fdfile_t *ff = atomic_load_consume(&fdp->fd_dt)->dt_ff[fd]; 1799 1800 ff->ff_exclose = exclose; 1801 if (exclose) 1802 fdp->fd_exclose = true; 1803 } 1804 1805 /* 1806 * Return descriptor owner information. If the value is positive, 1807 * it's process ID. If it's negative, it's process group ID and 1808 * needs the sign removed before use. 1809 */ 1810 int 1811 fgetown(pid_t pgid, u_long cmd, void *data) 1812 { 1813 1814 switch (cmd) { 1815 case TIOCGPGRP: 1816 *(int *)data = -pgid; 1817 break; 1818 default: 1819 *(int *)data = pgid; 1820 break; 1821 } 1822 return 0; 1823 } 1824 1825 /* 1826 * Send signal to descriptor owner, either process or process group. 1827 */ 1828 void 1829 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) 1830 { 1831 ksiginfo_t ksi; 1832 1833 KASSERT(!cpu_intr_p()); 1834 1835 if (pgid == 0) { 1836 return; 1837 } 1838 1839 KSI_INIT(&ksi); 1840 ksi.ksi_signo = signo; 1841 ksi.ksi_code = code; 1842 ksi.ksi_band = band; 1843 1844 mutex_enter(&proc_lock); 1845 if (pgid > 0) { 1846 struct proc *p1; 1847 1848 p1 = proc_find(pgid); 1849 if (p1 != NULL) { 1850 kpsignal(p1, &ksi, fdescdata); 1851 } 1852 } else { 1853 struct pgrp *pgrp; 1854 1855 KASSERT(pgid < 0); 1856 pgrp = pgrp_find(-pgid); 1857 if (pgrp != NULL) { 1858 kpgsignal(pgrp, &ksi, fdescdata, 0); 1859 } 1860 } 1861 mutex_exit(&proc_lock); 1862 } 1863 1864 int 1865 fd_clone(file_t *fp, unsigned fd, int flag, const struct fileops *fops, 1866 void *data) 1867 { 1868 fdfile_t *ff; 1869 filedesc_t *fdp; 1870 1871 fp->f_flag = flag & FMASK; 1872 fdp = curproc->p_fd; 1873 ff = atomic_load_consume(&fdp->fd_dt)->dt_ff[fd]; 1874 KASSERT(ff != NULL); 1875 ff->ff_exclose = (flag & O_CLOEXEC) != 0; 1876 fp->f_type = DTYPE_MISC; 1877 fp->f_ops = fops; 1878 fp->f_data = data; 1879 curlwp->l_dupfd = fd; 1880 fd_affix(curproc, fp, fd); 1881 1882 return EMOVEFD; 1883 } 1884 1885 int 1886 fnullop_fcntl(file_t *fp, u_int cmd, void *data) 1887 { 1888 1889 if (cmd == F_SETFL) 1890 return 0; 1891 1892 return EOPNOTSUPP; 1893 } 1894 1895 int 1896 fnullop_poll(file_t *fp, int which) 1897 { 1898 1899 return 0; 1900 } 1901 1902 int 1903 fnullop_kqfilter(file_t *fp, struct knote *kn) 1904 { 1905 1906 return EOPNOTSUPP; 1907 } 1908 1909 void 1910 fnullop_restart(file_t *fp) 1911 { 1912 1913 } 1914 1915 int 1916 fbadop_read(file_t *fp, off_t *offset, struct uio *uio, 1917 kauth_cred_t cred, int flags) 1918 { 1919 1920 return EOPNOTSUPP; 1921 } 1922 1923 int 1924 fbadop_write(file_t *fp, off_t *offset, struct uio *uio, 1925 kauth_cred_t cred, int flags) 1926 { 1927 1928 return EOPNOTSUPP; 1929 } 1930 1931 int 1932 fbadop_ioctl(file_t *fp, u_long com, void *data) 1933 { 1934 1935 return EOPNOTSUPP; 1936 } 1937 1938 int 1939 fbadop_stat(file_t *fp, struct stat *sb) 1940 { 1941 1942 return EOPNOTSUPP; 1943 } 1944 1945 int 1946 fbadop_close(file_t *fp) 1947 { 1948 1949 return EOPNOTSUPP; 1950 } 1951 1952 /* 1953 * sysctl routines pertaining to file descriptors 1954 */ 1955 1956 /* Initialized in sysctl_init() for now... */ 1957 extern kmutex_t sysctl_file_marker_lock; 1958 static u_int sysctl_file_marker = 1; 1959 1960 /* 1961 * Expects to be called with proc_lock and sysctl_file_marker_lock locked. 1962 */ 1963 static void 1964 sysctl_file_marker_reset(void) 1965 { 1966 struct proc *p; 1967 1968 PROCLIST_FOREACH(p, &allproc) { 1969 struct filedesc *fd = p->p_fd; 1970 fdtab_t *dt; 1971 u_int i; 1972 1973 mutex_enter(&fd->fd_lock); 1974 dt = fd->fd_dt; 1975 for (i = 0; i < dt->dt_nfiles; i++) { 1976 struct file *fp; 1977 fdfile_t *ff; 1978 1979 if ((ff = dt->dt_ff[i]) == NULL) { 1980 continue; 1981 } 1982 if ((fp = atomic_load_consume(&ff->ff_file)) == NULL) { 1983 continue; 1984 } 1985 fp->f_marker = 0; 1986 } 1987 mutex_exit(&fd->fd_lock); 1988 } 1989 } 1990 1991 /* 1992 * sysctl helper routine for kern.file pseudo-subtree. 1993 */ 1994 static int 1995 sysctl_kern_file(SYSCTLFN_ARGS) 1996 { 1997 const bool allowaddr = get_expose_address(curproc); 1998 struct filelist flist; 1999 int error; 2000 size_t buflen; 2001 struct file *fp, fbuf; 2002 char *start, *where; 2003 struct proc *p; 2004 2005 start = where = oldp; 2006 buflen = *oldlenp; 2007 2008 if (where == NULL) { 2009 /* 2010 * overestimate by 10 files 2011 */ 2012 *oldlenp = sizeof(filehead) + (nfiles + 10) * 2013 sizeof(struct file); 2014 return 0; 2015 } 2016 2017 /* 2018 * first sysctl_copyout filehead 2019 */ 2020 if (buflen < sizeof(filehead)) { 2021 *oldlenp = 0; 2022 return 0; 2023 } 2024 sysctl_unlock(); 2025 if (allowaddr) { 2026 memcpy(&flist, &filehead, sizeof(flist)); 2027 } else { 2028 memset(&flist, 0, sizeof(flist)); 2029 } 2030 error = sysctl_copyout(l, &flist, where, sizeof(flist)); 2031 if (error) { 2032 sysctl_relock(); 2033 return error; 2034 } 2035 buflen -= sizeof(flist); 2036 where += sizeof(flist); 2037 2038 /* 2039 * followed by an array of file structures 2040 */ 2041 mutex_enter(&sysctl_file_marker_lock); 2042 mutex_enter(&proc_lock); 2043 PROCLIST_FOREACH(p, &allproc) { 2044 struct filedesc *fd; 2045 fdtab_t *dt; 2046 u_int i; 2047 2048 if (p->p_stat == SIDL) { 2049 /* skip embryonic processes */ 2050 continue; 2051 } 2052 mutex_enter(p->p_lock); 2053 error = kauth_authorize_process(l->l_cred, 2054 KAUTH_PROCESS_CANSEE, p, 2055 KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), 2056 NULL, NULL); 2057 mutex_exit(p->p_lock); 2058 if (error != 0) { 2059 /* 2060 * Don't leak kauth retval if we're silently 2061 * skipping this entry. 2062 */ 2063 error = 0; 2064 continue; 2065 } 2066 2067 /* 2068 * Grab a hold on the process. 2069 */ 2070 if (!rw_tryenter(&p->p_reflock, RW_READER)) { 2071 continue; 2072 } 2073 mutex_exit(&proc_lock); 2074 2075 fd = p->p_fd; 2076 mutex_enter(&fd->fd_lock); 2077 dt = fd->fd_dt; 2078 for (i = 0; i < dt->dt_nfiles; i++) { 2079 fdfile_t *ff; 2080 2081 if ((ff = dt->dt_ff[i]) == NULL) { 2082 continue; 2083 } 2084 if ((fp = atomic_load_consume(&ff->ff_file)) == NULL) { 2085 continue; 2086 } 2087 2088 mutex_enter(&fp->f_lock); 2089 2090 if ((fp->f_count == 0) || 2091 (fp->f_marker == sysctl_file_marker)) { 2092 mutex_exit(&fp->f_lock); 2093 continue; 2094 } 2095 2096 /* Check that we have enough space. */ 2097 if (buflen < sizeof(struct file)) { 2098 *oldlenp = where - start; 2099 mutex_exit(&fp->f_lock); 2100 error = ENOMEM; 2101 break; 2102 } 2103 2104 fill_file(&fbuf, fp); 2105 mutex_exit(&fp->f_lock); 2106 error = sysctl_copyout(l, &fbuf, where, sizeof(fbuf)); 2107 if (error) { 2108 break; 2109 } 2110 buflen -= sizeof(struct file); 2111 where += sizeof(struct file); 2112 2113 fp->f_marker = sysctl_file_marker; 2114 } 2115 mutex_exit(&fd->fd_lock); 2116 2117 /* 2118 * Release reference to process. 2119 */ 2120 mutex_enter(&proc_lock); 2121 rw_exit(&p->p_reflock); 2122 2123 if (error) 2124 break; 2125 } 2126 2127 sysctl_file_marker++; 2128 /* Reset all markers if wrapped. */ 2129 if (sysctl_file_marker == 0) { 2130 sysctl_file_marker_reset(); 2131 sysctl_file_marker++; 2132 } 2133 2134 mutex_exit(&proc_lock); 2135 mutex_exit(&sysctl_file_marker_lock); 2136 2137 *oldlenp = where - start; 2138 sysctl_relock(); 2139 return error; 2140 } 2141 2142 /* 2143 * sysctl helper function for kern.file2 2144 */ 2145 static int 2146 sysctl_kern_file2(SYSCTLFN_ARGS) 2147 { 2148 struct proc *p; 2149 struct file *fp; 2150 struct filedesc *fd; 2151 struct kinfo_file kf; 2152 char *dp; 2153 u_int i, op; 2154 size_t len, needed, elem_size, out_size; 2155 int error, arg, elem_count; 2156 fdfile_t *ff; 2157 fdtab_t *dt; 2158 2159 if (namelen == 1 && name[0] == CTL_QUERY) 2160 return sysctl_query(SYSCTLFN_CALL(rnode)); 2161 2162 if (namelen != 4) 2163 return EINVAL; 2164 2165 error = 0; 2166 dp = oldp; 2167 len = (oldp != NULL) ? *oldlenp : 0; 2168 op = name[0]; 2169 arg = name[1]; 2170 elem_size = name[2]; 2171 elem_count = name[3]; 2172 out_size = MIN(sizeof(kf), elem_size); 2173 needed = 0; 2174 2175 if (elem_size < 1 || elem_count < 0) 2176 return EINVAL; 2177 2178 switch (op) { 2179 case KERN_FILE_BYFILE: 2180 case KERN_FILE_BYPID: 2181 /* 2182 * We're traversing the process list in both cases; the BYFILE 2183 * case does additional work of keeping track of files already 2184 * looked at. 2185 */ 2186 2187 /* doesn't use arg so it must be zero */ 2188 if ((op == KERN_FILE_BYFILE) && (arg != 0)) 2189 return EINVAL; 2190 2191 if ((op == KERN_FILE_BYPID) && (arg < -1)) 2192 /* -1 means all processes */ 2193 return EINVAL; 2194 2195 sysctl_unlock(); 2196 if (op == KERN_FILE_BYFILE) 2197 mutex_enter(&sysctl_file_marker_lock); 2198 mutex_enter(&proc_lock); 2199 PROCLIST_FOREACH(p, &allproc) { 2200 if (p->p_stat == SIDL) { 2201 /* skip embryonic processes */ 2202 continue; 2203 } 2204 if (arg > 0 && p->p_pid != arg) { 2205 /* pick only the one we want */ 2206 /* XXX want 0 to mean "kernel files" */ 2207 continue; 2208 } 2209 mutex_enter(p->p_lock); 2210 error = kauth_authorize_process(l->l_cred, 2211 KAUTH_PROCESS_CANSEE, p, 2212 KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), 2213 NULL, NULL); 2214 mutex_exit(p->p_lock); 2215 if (error != 0) { 2216 /* 2217 * Don't leak kauth retval if we're silently 2218 * skipping this entry. 2219 */ 2220 error = 0; 2221 continue; 2222 } 2223 2224 /* 2225 * Grab a hold on the process. 2226 */ 2227 if (!rw_tryenter(&p->p_reflock, RW_READER)) { 2228 continue; 2229 } 2230 mutex_exit(&proc_lock); 2231 2232 fd = p->p_fd; 2233 mutex_enter(&fd->fd_lock); 2234 dt = fd->fd_dt; 2235 for (i = 0; i < dt->dt_nfiles; i++) { 2236 if ((ff = dt->dt_ff[i]) == NULL) { 2237 continue; 2238 } 2239 if ((fp = atomic_load_consume(&ff->ff_file)) == 2240 NULL) { 2241 continue; 2242 } 2243 2244 if ((op == KERN_FILE_BYFILE) && 2245 (fp->f_marker == sysctl_file_marker)) { 2246 continue; 2247 } 2248 if (len >= elem_size && elem_count > 0) { 2249 mutex_enter(&fp->f_lock); 2250 fill_file2(&kf, fp, ff, i, p->p_pid); 2251 mutex_exit(&fp->f_lock); 2252 mutex_exit(&fd->fd_lock); 2253 error = sysctl_copyout(l, 2254 &kf, dp, out_size); 2255 mutex_enter(&fd->fd_lock); 2256 if (error) 2257 break; 2258 dp += elem_size; 2259 len -= elem_size; 2260 } 2261 if (op == KERN_FILE_BYFILE) 2262 fp->f_marker = sysctl_file_marker; 2263 needed += elem_size; 2264 if (elem_count > 0 && elem_count != INT_MAX) 2265 elem_count--; 2266 } 2267 mutex_exit(&fd->fd_lock); 2268 2269 /* 2270 * Release reference to process. 2271 */ 2272 mutex_enter(&proc_lock); 2273 rw_exit(&p->p_reflock); 2274 } 2275 if (op == KERN_FILE_BYFILE) { 2276 sysctl_file_marker++; 2277 2278 /* Reset all markers if wrapped. */ 2279 if (sysctl_file_marker == 0) { 2280 sysctl_file_marker_reset(); 2281 sysctl_file_marker++; 2282 } 2283 } 2284 mutex_exit(&proc_lock); 2285 if (op == KERN_FILE_BYFILE) 2286 mutex_exit(&sysctl_file_marker_lock); 2287 sysctl_relock(); 2288 break; 2289 default: 2290 return EINVAL; 2291 } 2292 2293 if (oldp == NULL) 2294 needed += KERN_FILESLOP * elem_size; 2295 *oldlenp = needed; 2296 2297 return error; 2298 } 2299 2300 static void 2301 fill_file(struct file *fp, const struct file *fpsrc) 2302 { 2303 const bool allowaddr = get_expose_address(curproc); 2304 2305 memset(fp, 0, sizeof(*fp)); 2306 2307 fp->f_offset = fpsrc->f_offset; 2308 COND_SET_PTR(fp->f_cred, fpsrc->f_cred, allowaddr); 2309 COND_SET_CPTR(fp->f_ops, fpsrc->f_ops, allowaddr); 2310 COND_SET_STRUCT(fp->f_undata, fpsrc->f_undata, allowaddr); 2311 COND_SET_STRUCT(fp->f_list, fpsrc->f_list, allowaddr); 2312 fp->f_flag = fpsrc->f_flag; 2313 fp->f_marker = fpsrc->f_marker; 2314 fp->f_type = fpsrc->f_type; 2315 fp->f_advice = fpsrc->f_advice; 2316 fp->f_count = fpsrc->f_count; 2317 fp->f_msgcount = fpsrc->f_msgcount; 2318 fp->f_unpcount = fpsrc->f_unpcount; 2319 COND_SET_STRUCT(fp->f_unplist, fpsrc->f_unplist, allowaddr); 2320 } 2321 2322 static void 2323 fill_file2(struct kinfo_file *kp, const file_t *fp, const fdfile_t *ff, 2324 int i, pid_t pid) 2325 { 2326 const bool allowaddr = get_expose_address(curproc); 2327 2328 memset(kp, 0, sizeof(*kp)); 2329 2330 COND_SET_VALUE(kp->ki_fileaddr, PTRTOUINT64(fp), allowaddr); 2331 kp->ki_flag = fp->f_flag; 2332 kp->ki_iflags = 0; 2333 kp->ki_ftype = fp->f_type; 2334 kp->ki_count = fp->f_count; 2335 kp->ki_msgcount = fp->f_msgcount; 2336 COND_SET_VALUE(kp->ki_fucred, PTRTOUINT64(fp->f_cred), allowaddr); 2337 kp->ki_fuid = kauth_cred_geteuid(fp->f_cred); 2338 kp->ki_fgid = kauth_cred_getegid(fp->f_cred); 2339 COND_SET_VALUE(kp->ki_fops, PTRTOUINT64(fp->f_ops), allowaddr); 2340 kp->ki_foffset = fp->f_offset; 2341 COND_SET_VALUE(kp->ki_fdata, PTRTOUINT64(fp->f_data), allowaddr); 2342 2343 /* vnode information to glue this file to something */ 2344 if (fp->f_type == DTYPE_VNODE) { 2345 struct vnode *vp = fp->f_vnode; 2346 2347 COND_SET_VALUE(kp->ki_vun, PTRTOUINT64(vp->v_un.vu_socket), 2348 allowaddr); 2349 kp->ki_vsize = vp->v_size; 2350 kp->ki_vtype = vp->v_type; 2351 kp->ki_vtag = vp->v_tag; 2352 COND_SET_VALUE(kp->ki_vdata, PTRTOUINT64(vp->v_data), 2353 allowaddr); 2354 } 2355 2356 /* process information when retrieved via KERN_FILE_BYPID */ 2357 if (ff != NULL) { 2358 kp->ki_pid = pid; 2359 kp->ki_fd = i; 2360 kp->ki_ofileflags = ff->ff_exclose; 2361 kp->ki_usecount = ff->ff_refcnt; 2362 } 2363 } 2364