1 /* $NetBSD: kern_descrip.c,v 1.214 2011/04/24 20:30:38 rmind 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 1.214 2011/04/24 20:30:38 rmind 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 kinfo_file *, const file_t *, const fdfile_t *, 122 int, pid_t); 123 124 const struct cdevsw filedesc_cdevsw = { 125 filedescopen, noclose, noread, nowrite, noioctl, 126 nostop, notty, nopoll, nommap, nokqfilter, D_OTHER | D_MPSAFE, 127 }; 128 129 /* For ease of reading. */ 130 __strong_alias(fd_putvnode,fd_putfile) 131 __strong_alias(fd_putsock,fd_putfile) 132 133 /* 134 * Initialize the descriptor system. 135 */ 136 void 137 fd_sys_init(void) 138 { 139 static struct sysctllog *clog; 140 141 mutex_init(&filelist_lock, MUTEX_DEFAULT, IPL_NONE); 142 143 file_cache = pool_cache_init(sizeof(file_t), coherency_unit, 0, 144 0, "file", NULL, IPL_NONE, file_ctor, file_dtor, NULL); 145 KASSERT(file_cache != NULL); 146 147 fdfile_cache = pool_cache_init(sizeof(fdfile_t), coherency_unit, 0, 148 PR_LARGECACHE, "fdfile", NULL, IPL_NONE, fdfile_ctor, fdfile_dtor, 149 NULL); 150 KASSERT(fdfile_cache != NULL); 151 152 filedesc_cache = pool_cache_init(sizeof(filedesc_t), coherency_unit, 153 0, 0, "filedesc", NULL, IPL_NONE, filedesc_ctor, filedesc_dtor, 154 NULL); 155 KASSERT(filedesc_cache != NULL); 156 157 sysctl_createv(&clog, 0, NULL, NULL, 158 CTLFLAG_PERMANENT, CTLTYPE_NODE, "kern", NULL, 159 NULL, 0, NULL, 0, CTL_KERN, CTL_EOL); 160 sysctl_createv(&clog, 0, NULL, NULL, 161 CTLFLAG_PERMANENT, 162 CTLTYPE_STRUCT, "file", 163 SYSCTL_DESCR("System open file table"), 164 sysctl_kern_file, 0, NULL, 0, 165 CTL_KERN, KERN_FILE, CTL_EOL); 166 sysctl_createv(&clog, 0, NULL, NULL, 167 CTLFLAG_PERMANENT, 168 CTLTYPE_STRUCT, "file2", 169 SYSCTL_DESCR("System open file table"), 170 sysctl_kern_file2, 0, NULL, 0, 171 CTL_KERN, KERN_FILE2, CTL_EOL); 172 } 173 174 static bool 175 fd_isused(filedesc_t *fdp, unsigned fd) 176 { 177 u_int off = fd >> NDENTRYSHIFT; 178 179 KASSERT(fd < fdp->fd_dt->dt_nfiles); 180 181 return (fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0; 182 } 183 184 /* 185 * Verify that the bitmaps match the descriptor table. 186 */ 187 static inline void 188 fd_checkmaps(filedesc_t *fdp) 189 { 190 #ifdef DEBUG 191 fdtab_t *dt; 192 u_int fd; 193 194 dt = fdp->fd_dt; 195 if (fdp->fd_refcnt == -1) { 196 /* 197 * fd_free tears down the table without maintaining its bitmap. 198 */ 199 return; 200 } 201 for (fd = 0; fd < dt->dt_nfiles; fd++) { 202 if (fd < NDFDFILE) { 203 KASSERT(dt->dt_ff[fd] == 204 (fdfile_t *)fdp->fd_dfdfile[fd]); 205 } 206 if (dt->dt_ff[fd] == NULL) { 207 KASSERT(!fd_isused(fdp, fd)); 208 } else if (dt->dt_ff[fd]->ff_file != NULL) { 209 KASSERT(fd_isused(fdp, fd)); 210 } 211 } 212 #endif 213 } 214 215 static int 216 fd_next_zero(filedesc_t *fdp, uint32_t *bitmap, int want, u_int bits) 217 { 218 int i, off, maxoff; 219 uint32_t sub; 220 221 KASSERT(mutex_owned(&fdp->fd_lock)); 222 223 fd_checkmaps(fdp); 224 225 if (want > bits) 226 return -1; 227 228 off = want >> NDENTRYSHIFT; 229 i = want & NDENTRYMASK; 230 if (i) { 231 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); 232 if (sub != ~0) 233 goto found; 234 off++; 235 } 236 237 maxoff = NDLOSLOTS(bits); 238 while (off < maxoff) { 239 if ((sub = bitmap[off]) != ~0) 240 goto found; 241 off++; 242 } 243 244 return -1; 245 246 found: 247 return (off << NDENTRYSHIFT) + ffs(~sub) - 1; 248 } 249 250 static int 251 fd_last_set(filedesc_t *fd, int last) 252 { 253 int off, i; 254 fdfile_t **ff = fd->fd_dt->dt_ff; 255 uint32_t *bitmap = fd->fd_lomap; 256 257 KASSERT(mutex_owned(&fd->fd_lock)); 258 259 fd_checkmaps(fd); 260 261 off = (last - 1) >> NDENTRYSHIFT; 262 263 while (off >= 0 && !bitmap[off]) 264 off--; 265 266 if (off < 0) 267 return -1; 268 269 i = ((off + 1) << NDENTRYSHIFT) - 1; 270 if (i >= last) 271 i = last - 1; 272 273 /* XXX should use bitmap */ 274 while (i > 0 && (ff[i] == NULL || !ff[i]->ff_allocated)) 275 i--; 276 277 return i; 278 } 279 280 static inline void 281 fd_used(filedesc_t *fdp, unsigned fd) 282 { 283 u_int off = fd >> NDENTRYSHIFT; 284 fdfile_t *ff; 285 286 ff = fdp->fd_dt->dt_ff[fd]; 287 288 KASSERT(mutex_owned(&fdp->fd_lock)); 289 KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) == 0); 290 KASSERT(ff != NULL); 291 KASSERT(ff->ff_file == NULL); 292 KASSERT(!ff->ff_allocated); 293 294 ff->ff_allocated = 1; 295 fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK); 296 if (__predict_false(fdp->fd_lomap[off] == ~0)) { 297 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 298 (1 << (off & NDENTRYMASK))) == 0); 299 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK); 300 } 301 302 if ((int)fd > fdp->fd_lastfile) { 303 fdp->fd_lastfile = fd; 304 } 305 306 fd_checkmaps(fdp); 307 } 308 309 static inline void 310 fd_unused(filedesc_t *fdp, unsigned fd) 311 { 312 u_int off = fd >> NDENTRYSHIFT; 313 fdfile_t *ff; 314 315 ff = fdp->fd_dt->dt_ff[fd]; 316 317 /* 318 * Don't assert the lock is held here, as we may be copying 319 * the table during exec() and it is not needed there. 320 * procfs and sysctl are locked out by proc::p_reflock. 321 * 322 * KASSERT(mutex_owned(&fdp->fd_lock)); 323 */ 324 KASSERT(ff != NULL); 325 KASSERT(ff->ff_file == NULL); 326 KASSERT(ff->ff_allocated); 327 328 if (fd < fdp->fd_freefile) { 329 fdp->fd_freefile = fd; 330 } 331 332 if (fdp->fd_lomap[off] == ~0) { 333 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 334 (1 << (off & NDENTRYMASK))) != 0); 335 fdp->fd_himap[off >> NDENTRYSHIFT] &= 336 ~(1 << (off & NDENTRYMASK)); 337 } 338 KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0); 339 fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK)); 340 ff->ff_allocated = 0; 341 342 KASSERT(fd <= fdp->fd_lastfile); 343 if (fd == fdp->fd_lastfile) { 344 fdp->fd_lastfile = fd_last_set(fdp, fd); 345 } 346 fd_checkmaps(fdp); 347 } 348 349 /* 350 * Look up the file structure corresponding to a file descriptor 351 * and return the file, holding a reference on the descriptor. 352 */ 353 file_t * 354 fd_getfile(unsigned fd) 355 { 356 filedesc_t *fdp; 357 fdfile_t *ff; 358 file_t *fp; 359 fdtab_t *dt; 360 361 /* 362 * Look up the fdfile structure representing this descriptor. 363 * We are doing this unlocked. See fd_tryexpand(). 364 */ 365 fdp = curlwp->l_fd; 366 dt = fdp->fd_dt; 367 if (__predict_false(fd >= dt->dt_nfiles)) { 368 return NULL; 369 } 370 ff = dt->dt_ff[fd]; 371 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 372 if (__predict_false(ff == NULL)) { 373 return NULL; 374 } 375 376 /* Now get a reference to the descriptor. */ 377 if (fdp->fd_refcnt == 1) { 378 /* 379 * Single threaded: don't need to worry about concurrent 380 * access (other than earlier calls to kqueue, which may 381 * hold a reference to the descriptor). 382 */ 383 ff->ff_refcnt++; 384 } else { 385 /* 386 * Multi threaded: issue a memory barrier to ensure that we 387 * acquire the file pointer _after_ adding a reference. If 388 * no memory barrier, we could fetch a stale pointer. 389 */ 390 atomic_inc_uint(&ff->ff_refcnt); 391 #ifndef __HAVE_ATOMIC_AS_MEMBAR 392 membar_enter(); 393 #endif 394 } 395 396 /* 397 * If the file is not open or is being closed then put the 398 * reference back. 399 */ 400 fp = ff->ff_file; 401 if (__predict_true(fp != NULL)) { 402 return fp; 403 } 404 fd_putfile(fd); 405 return NULL; 406 } 407 408 /* 409 * Release a reference to a file descriptor acquired with fd_getfile(). 410 */ 411 void 412 fd_putfile(unsigned fd) 413 { 414 filedesc_t *fdp; 415 fdfile_t *ff; 416 u_int u, v; 417 418 fdp = curlwp->l_fd; 419 ff = fdp->fd_dt->dt_ff[fd]; 420 421 KASSERT(fd < fdp->fd_dt->dt_nfiles); 422 KASSERT(ff != NULL); 423 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 424 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 425 426 if (fdp->fd_refcnt == 1) { 427 /* 428 * Single threaded: don't need to worry about concurrent 429 * access (other than earlier calls to kqueue, which may 430 * hold a reference to the descriptor). 431 */ 432 if (__predict_false((ff->ff_refcnt & FR_CLOSING) != 0)) { 433 fd_close(fd); 434 return; 435 } 436 ff->ff_refcnt--; 437 return; 438 } 439 440 /* 441 * Ensure that any use of the file is complete and globally 442 * visible before dropping the final reference. If no membar, 443 * the current CPU could still access memory associated with 444 * the file after it has been freed or recycled by another 445 * CPU. 446 */ 447 #ifndef __HAVE_ATOMIC_AS_MEMBAR 448 membar_exit(); 449 #endif 450 451 /* 452 * Be optimistic and start out with the assumption that no other 453 * threads are trying to close the descriptor. If the CAS fails, 454 * we lost a race and/or it's being closed. 455 */ 456 for (u = ff->ff_refcnt & FR_MASK;; u = v) { 457 v = atomic_cas_uint(&ff->ff_refcnt, u, u - 1); 458 if (__predict_true(u == v)) { 459 return; 460 } 461 if (__predict_false((v & FR_CLOSING) != 0)) { 462 break; 463 } 464 } 465 466 /* Another thread is waiting to close the file: join it. */ 467 (void)fd_close(fd); 468 } 469 470 /* 471 * Convenience wrapper around fd_getfile() that returns reference 472 * to a vnode. 473 */ 474 int 475 fd_getvnode(unsigned fd, file_t **fpp) 476 { 477 vnode_t *vp; 478 file_t *fp; 479 480 fp = fd_getfile(fd); 481 if (__predict_false(fp == NULL)) { 482 return EBADF; 483 } 484 if (__predict_false(fp->f_type != DTYPE_VNODE)) { 485 fd_putfile(fd); 486 return EINVAL; 487 } 488 vp = fp->f_data; 489 if (__predict_false(vp->v_type == VBAD)) { 490 /* XXX Is this case really necessary? */ 491 fd_putfile(fd); 492 return EBADF; 493 } 494 *fpp = fp; 495 return 0; 496 } 497 498 /* 499 * Convenience wrapper around fd_getfile() that returns reference 500 * to a socket. 501 */ 502 int 503 fd_getsock(unsigned fd, struct socket **sop) 504 { 505 file_t *fp; 506 507 fp = fd_getfile(fd); 508 if (__predict_false(fp == NULL)) { 509 return EBADF; 510 } 511 if (__predict_false(fp->f_type != DTYPE_SOCKET)) { 512 fd_putfile(fd); 513 return ENOTSOCK; 514 } 515 *sop = fp->f_data; 516 return 0; 517 } 518 519 /* 520 * Look up the file structure corresponding to a file descriptor 521 * and return it with a reference held on the file, not the 522 * descriptor. 523 * 524 * This is heavyweight and only used when accessing descriptors 525 * from a foreign process. The caller must ensure that `p' does 526 * not exit or fork across this call. 527 * 528 * To release the file (not descriptor) reference, use closef(). 529 */ 530 file_t * 531 fd_getfile2(proc_t *p, unsigned fd) 532 { 533 filedesc_t *fdp; 534 fdfile_t *ff; 535 file_t *fp; 536 fdtab_t *dt; 537 538 fdp = p->p_fd; 539 mutex_enter(&fdp->fd_lock); 540 dt = fdp->fd_dt; 541 if (fd >= dt->dt_nfiles) { 542 mutex_exit(&fdp->fd_lock); 543 return NULL; 544 } 545 if ((ff = dt->dt_ff[fd]) == NULL) { 546 mutex_exit(&fdp->fd_lock); 547 return NULL; 548 } 549 if ((fp = ff->ff_file) == NULL) { 550 mutex_exit(&fdp->fd_lock); 551 return NULL; 552 } 553 mutex_enter(&fp->f_lock); 554 fp->f_count++; 555 mutex_exit(&fp->f_lock); 556 mutex_exit(&fdp->fd_lock); 557 558 return fp; 559 } 560 561 /* 562 * Internal form of close. Must be called with a reference to the 563 * descriptor, and will drop the reference. When all descriptor 564 * references are dropped, releases the descriptor slot and a single 565 * reference to the file structure. 566 */ 567 int 568 fd_close(unsigned fd) 569 { 570 struct flock lf; 571 filedesc_t *fdp; 572 fdfile_t *ff; 573 file_t *fp; 574 proc_t *p; 575 lwp_t *l; 576 u_int refcnt; 577 578 l = curlwp; 579 p = l->l_proc; 580 fdp = l->l_fd; 581 ff = fdp->fd_dt->dt_ff[fd]; 582 583 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 584 585 mutex_enter(&fdp->fd_lock); 586 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 587 if (__predict_false(ff->ff_file == NULL)) { 588 /* 589 * Another user of the file is already closing, and is 590 * waiting for other users of the file to drain. Release 591 * our reference, and wake up the closer. 592 */ 593 atomic_dec_uint(&ff->ff_refcnt); 594 cv_broadcast(&ff->ff_closing); 595 mutex_exit(&fdp->fd_lock); 596 597 /* 598 * An application error, so pretend that the descriptor 599 * was already closed. We can't safely wait for it to 600 * be closed without potentially deadlocking. 601 */ 602 return (EBADF); 603 } 604 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 605 606 /* 607 * There may be multiple users of this file within the process. 608 * Notify existing and new users that the file is closing. This 609 * will prevent them from adding additional uses to this file 610 * while we are closing it. 611 */ 612 fp = ff->ff_file; 613 ff->ff_file = NULL; 614 ff->ff_exclose = false; 615 616 /* 617 * We expect the caller to hold a descriptor reference - drop it. 618 * The reference count may increase beyond zero at this point due 619 * to an erroneous descriptor reference by an application, but 620 * fd_getfile() will notice that the file is being closed and drop 621 * the reference again. 622 */ 623 if (fdp->fd_refcnt == 1) { 624 /* Single threaded. */ 625 refcnt = --(ff->ff_refcnt); 626 } else { 627 /* Multi threaded. */ 628 #ifndef __HAVE_ATOMIC_AS_MEMBAR 629 membar_producer(); 630 #endif 631 refcnt = atomic_dec_uint_nv(&ff->ff_refcnt); 632 } 633 if (__predict_false(refcnt != 0)) { 634 /* 635 * Wait for other references to drain. This is typically 636 * an application error - the descriptor is being closed 637 * while still in use. 638 * (Or just a threaded application trying to unblock its 639 * thread that sleeps in (say) accept()). 640 */ 641 atomic_or_uint(&ff->ff_refcnt, FR_CLOSING); 642 643 /* 644 * Remove any knotes attached to the file. A knote 645 * attached to the descriptor can hold references on it. 646 */ 647 mutex_exit(&fdp->fd_lock); 648 if (!SLIST_EMPTY(&ff->ff_knlist)) { 649 knote_fdclose(fd); 650 } 651 652 /* 653 * Since the file system code doesn't know which fd 654 * each request came from (think dup()), we have to 655 * ask it to return ERESTART for any long-term blocks. 656 * The re-entry through read/write/etc will detect the 657 * closed fd and return EBAFD. 658 * Blocked partial writes may return a short length. 659 */ 660 (*fp->f_ops->fo_restart)(fp); 661 mutex_enter(&fdp->fd_lock); 662 663 /* 664 * We need to see the count drop to zero at least once, 665 * in order to ensure that all pre-existing references 666 * have been drained. New references past this point are 667 * of no interest. 668 * XXX (dsl) this may need to call fo_restart() after a 669 * timeout to guarantee that all the system calls exit. 670 */ 671 while ((ff->ff_refcnt & FR_MASK) != 0) { 672 cv_wait(&ff->ff_closing, &fdp->fd_lock); 673 } 674 atomic_and_uint(&ff->ff_refcnt, ~FR_CLOSING); 675 } else { 676 /* If no references, there must be no knotes. */ 677 KASSERT(SLIST_EMPTY(&ff->ff_knlist)); 678 } 679 680 /* 681 * POSIX record locking dictates that any close releases ALL 682 * locks owned by this process. This is handled by setting 683 * a flag in the unlock to free ONLY locks obeying POSIX 684 * semantics, and not to free BSD-style file locks. 685 * If the descriptor was in a message, POSIX-style locks 686 * aren't passed with the descriptor. 687 */ 688 if (__predict_false((p->p_flag & PK_ADVLOCK) != 0 && 689 fp->f_type == DTYPE_VNODE)) { 690 lf.l_whence = SEEK_SET; 691 lf.l_start = 0; 692 lf.l_len = 0; 693 lf.l_type = F_UNLCK; 694 mutex_exit(&fdp->fd_lock); 695 (void)VOP_ADVLOCK(fp->f_data, p, F_UNLCK, &lf, F_POSIX); 696 mutex_enter(&fdp->fd_lock); 697 } 698 699 /* Free descriptor slot. */ 700 fd_unused(fdp, fd); 701 mutex_exit(&fdp->fd_lock); 702 703 /* Now drop reference to the file itself. */ 704 return closef(fp); 705 } 706 707 /* 708 * Duplicate a file descriptor. 709 */ 710 int 711 fd_dup(file_t *fp, int minfd, int *newp, bool exclose) 712 { 713 proc_t *p = curproc; 714 int error; 715 716 while ((error = fd_alloc(p, minfd, newp)) != 0) { 717 if (error != ENOSPC) { 718 return error; 719 } 720 fd_tryexpand(p); 721 } 722 723 curlwp->l_fd->fd_dt->dt_ff[*newp]->ff_exclose = exclose; 724 fd_affix(p, fp, *newp); 725 return 0; 726 } 727 728 /* 729 * dup2 operation. 730 */ 731 int 732 fd_dup2(file_t *fp, unsigned new) 733 { 734 filedesc_t *fdp = curlwp->l_fd; 735 fdfile_t *ff; 736 fdtab_t *dt; 737 738 /* 739 * Ensure there are enough slots in the descriptor table, 740 * and allocate an fdfile_t up front in case we need it. 741 */ 742 while (new >= fdp->fd_dt->dt_nfiles) { 743 fd_tryexpand(curproc); 744 } 745 ff = pool_cache_get(fdfile_cache, PR_WAITOK); 746 747 /* 748 * If there is already a file open, close it. If the file is 749 * half open, wait for it to be constructed before closing it. 750 * XXX Potential for deadlock here? 751 */ 752 mutex_enter(&fdp->fd_lock); 753 while (fd_isused(fdp, new)) { 754 mutex_exit(&fdp->fd_lock); 755 if (fd_getfile(new) != NULL) { 756 (void)fd_close(new); 757 } else { 758 /* 759 * Crummy, but unlikely to happen. 760 * Can occur if we interrupt another 761 * thread while it is opening a file. 762 */ 763 kpause("dup2", false, 1, NULL); 764 } 765 mutex_enter(&fdp->fd_lock); 766 } 767 dt = fdp->fd_dt; 768 if (dt->dt_ff[new] == NULL) { 769 KASSERT(new >= NDFDFILE); 770 dt->dt_ff[new] = ff; 771 ff = NULL; 772 } 773 fd_used(fdp, new); 774 mutex_exit(&fdp->fd_lock); 775 776 /* Slot is now allocated. Insert copy of the file. */ 777 fd_affix(curproc, fp, new); 778 if (ff != NULL) { 779 pool_cache_put(fdfile_cache, ff); 780 } 781 return 0; 782 } 783 784 /* 785 * Drop reference to a file structure. 786 */ 787 int 788 closef(file_t *fp) 789 { 790 struct flock lf; 791 int error; 792 793 /* 794 * Drop reference. If referenced elsewhere it's still open 795 * and we have nothing more to do. 796 */ 797 mutex_enter(&fp->f_lock); 798 KASSERT(fp->f_count > 0); 799 if (--fp->f_count > 0) { 800 mutex_exit(&fp->f_lock); 801 return 0; 802 } 803 KASSERT(fp->f_count == 0); 804 mutex_exit(&fp->f_lock); 805 806 /* We held the last reference - release locks, close and free. */ 807 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 808 lf.l_whence = SEEK_SET; 809 lf.l_start = 0; 810 lf.l_len = 0; 811 lf.l_type = F_UNLCK; 812 (void)VOP_ADVLOCK(fp->f_data, fp, F_UNLCK, &lf, F_FLOCK); 813 } 814 if (fp->f_ops != NULL) { 815 error = (*fp->f_ops->fo_close)(fp); 816 } else { 817 error = 0; 818 } 819 KASSERT(fp->f_count == 0); 820 KASSERT(fp->f_cred != NULL); 821 pool_cache_put(file_cache, fp); 822 823 return error; 824 } 825 826 /* 827 * Allocate a file descriptor for the process. 828 */ 829 int 830 fd_alloc(proc_t *p, int want, int *result) 831 { 832 filedesc_t *fdp = p->p_fd; 833 int i, lim, last, error; 834 u_int off, new; 835 fdtab_t *dt; 836 837 KASSERT(p == curproc || p == &proc0); 838 839 /* 840 * Search for a free descriptor starting at the higher 841 * of want or fd_freefile. 842 */ 843 mutex_enter(&fdp->fd_lock); 844 fd_checkmaps(fdp); 845 dt = fdp->fd_dt; 846 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 847 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 848 last = min(dt->dt_nfiles, lim); 849 for (;;) { 850 if ((i = want) < fdp->fd_freefile) 851 i = fdp->fd_freefile; 852 off = i >> NDENTRYSHIFT; 853 new = fd_next_zero(fdp, fdp->fd_himap, off, 854 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 855 if (new == -1) 856 break; 857 i = fd_next_zero(fdp, &fdp->fd_lomap[new], 858 new > off ? 0 : i & NDENTRYMASK, NDENTRIES); 859 if (i == -1) { 860 /* 861 * Free file descriptor in this block was 862 * below want, try again with higher want. 863 */ 864 want = (new + 1) << NDENTRYSHIFT; 865 continue; 866 } 867 i += (new << NDENTRYSHIFT); 868 if (i >= last) { 869 break; 870 } 871 if (dt->dt_ff[i] == NULL) { 872 KASSERT(i >= NDFDFILE); 873 dt->dt_ff[i] = pool_cache_get(fdfile_cache, PR_WAITOK); 874 } 875 KASSERT(dt->dt_ff[i]->ff_file == NULL); 876 fd_used(fdp, i); 877 if (want <= fdp->fd_freefile) { 878 fdp->fd_freefile = i; 879 } 880 *result = i; 881 KASSERT(i >= NDFDFILE || 882 dt->dt_ff[i] == (fdfile_t *)fdp->fd_dfdfile[i]); 883 fd_checkmaps(fdp); 884 mutex_exit(&fdp->fd_lock); 885 return 0; 886 } 887 888 /* No space in current array. Let the caller expand and retry. */ 889 error = (dt->dt_nfiles >= lim) ? EMFILE : ENOSPC; 890 mutex_exit(&fdp->fd_lock); 891 return error; 892 } 893 894 /* 895 * Allocate memory for a descriptor table. 896 */ 897 static fdtab_t * 898 fd_dtab_alloc(int n) 899 { 900 fdtab_t *dt; 901 size_t sz; 902 903 KASSERT(n > NDFILE); 904 905 sz = sizeof(*dt) + (n - NDFILE) * sizeof(dt->dt_ff[0]); 906 dt = kmem_alloc(sz, KM_SLEEP); 907 #ifdef DIAGNOSTIC 908 memset(dt, 0xff, sz); 909 #endif 910 dt->dt_nfiles = n; 911 dt->dt_link = NULL; 912 return dt; 913 } 914 915 /* 916 * Free a descriptor table, and all tables linked for deferred free. 917 */ 918 static void 919 fd_dtab_free(fdtab_t *dt) 920 { 921 fdtab_t *next; 922 size_t sz; 923 924 do { 925 next = dt->dt_link; 926 KASSERT(dt->dt_nfiles > NDFILE); 927 sz = sizeof(*dt) + 928 (dt->dt_nfiles - NDFILE) * sizeof(dt->dt_ff[0]); 929 #ifdef DIAGNOSTIC 930 memset(dt, 0xff, sz); 931 #endif 932 kmem_free(dt, sz); 933 dt = next; 934 } while (dt != NULL); 935 } 936 937 /* 938 * Allocate descriptor bitmap. 939 */ 940 static void 941 fd_map_alloc(int n, uint32_t **lo, uint32_t **hi) 942 { 943 uint8_t *ptr; 944 size_t szlo, szhi; 945 946 KASSERT(n > NDENTRIES); 947 948 szlo = NDLOSLOTS(n) * sizeof(uint32_t); 949 szhi = NDHISLOTS(n) * sizeof(uint32_t); 950 ptr = kmem_alloc(szlo + szhi, KM_SLEEP); 951 *lo = (uint32_t *)ptr; 952 *hi = (uint32_t *)(ptr + szlo); 953 } 954 955 /* 956 * Free descriptor bitmap. 957 */ 958 static void 959 fd_map_free(int n, uint32_t *lo, uint32_t *hi) 960 { 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 KASSERT(hi == (uint32_t *)((uint8_t *)lo + szlo)); 968 kmem_free(lo, szlo + szhi); 969 } 970 971 /* 972 * Expand a process' descriptor table. 973 */ 974 void 975 fd_tryexpand(proc_t *p) 976 { 977 filedesc_t *fdp; 978 int i, numfiles, oldnfiles; 979 fdtab_t *newdt, *dt; 980 uint32_t *newhimap, *newlomap; 981 982 KASSERT(p == curproc || p == &proc0); 983 984 fdp = p->p_fd; 985 newhimap = NULL; 986 newlomap = NULL; 987 oldnfiles = fdp->fd_dt->dt_nfiles; 988 989 if (oldnfiles < NDEXTENT) 990 numfiles = NDEXTENT; 991 else 992 numfiles = 2 * oldnfiles; 993 994 newdt = fd_dtab_alloc(numfiles); 995 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 996 fd_map_alloc(numfiles, &newlomap, &newhimap); 997 } 998 999 mutex_enter(&fdp->fd_lock); 1000 dt = fdp->fd_dt; 1001 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1002 if (dt->dt_nfiles != oldnfiles) { 1003 /* fdp changed; caller must retry */ 1004 mutex_exit(&fdp->fd_lock); 1005 fd_dtab_free(newdt); 1006 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1007 fd_map_free(numfiles, newlomap, newhimap); 1008 } 1009 return; 1010 } 1011 1012 /* Copy the existing descriptor table and zero the new portion. */ 1013 i = sizeof(fdfile_t *) * oldnfiles; 1014 memcpy(newdt->dt_ff, dt->dt_ff, i); 1015 memset((uint8_t *)newdt->dt_ff + i, 0, 1016 numfiles * sizeof(fdfile_t *) - i); 1017 1018 /* 1019 * Link old descriptor array into list to be discarded. We defer 1020 * freeing until the last reference to the descriptor table goes 1021 * away (usually process exit). This allows us to do lockless 1022 * lookups in fd_getfile(). 1023 */ 1024 if (oldnfiles > NDFILE) { 1025 if (fdp->fd_refcnt > 1) { 1026 newdt->dt_link = dt; 1027 } else { 1028 fd_dtab_free(dt); 1029 } 1030 } 1031 1032 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1033 i = NDHISLOTS(oldnfiles) * sizeof(uint32_t); 1034 memcpy(newhimap, fdp->fd_himap, i); 1035 memset((uint8_t *)newhimap + i, 0, 1036 NDHISLOTS(numfiles) * sizeof(uint32_t) - i); 1037 1038 i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t); 1039 memcpy(newlomap, fdp->fd_lomap, i); 1040 memset((uint8_t *)newlomap + i, 0, 1041 NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); 1042 1043 if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { 1044 fd_map_free(oldnfiles, fdp->fd_lomap, fdp->fd_himap); 1045 } 1046 fdp->fd_himap = newhimap; 1047 fdp->fd_lomap = newlomap; 1048 } 1049 1050 /* 1051 * All other modifications must become globally visible before 1052 * the change to fd_dt. See fd_getfile(). 1053 */ 1054 membar_producer(); 1055 fdp->fd_dt = newdt; 1056 KASSERT(newdt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1057 fd_checkmaps(fdp); 1058 mutex_exit(&fdp->fd_lock); 1059 } 1060 1061 /* 1062 * Create a new open file structure and allocate a file descriptor 1063 * for the current process. 1064 */ 1065 int 1066 fd_allocfile(file_t **resultfp, int *resultfd) 1067 { 1068 proc_t *p = curproc; 1069 kauth_cred_t cred; 1070 file_t *fp; 1071 int error; 1072 1073 while ((error = fd_alloc(p, 0, resultfd)) != 0) { 1074 if (error != ENOSPC) { 1075 return error; 1076 } 1077 fd_tryexpand(p); 1078 } 1079 1080 fp = pool_cache_get(file_cache, PR_WAITOK); 1081 if (fp == NULL) { 1082 return ENFILE; 1083 } 1084 KASSERT(fp->f_count == 0); 1085 KASSERT(fp->f_msgcount == 0); 1086 KASSERT(fp->f_unpcount == 0); 1087 1088 /* Replace cached credentials if not what we need. */ 1089 cred = curlwp->l_cred; 1090 if (__predict_false(cred != fp->f_cred)) { 1091 kauth_cred_free(fp->f_cred); 1092 kauth_cred_hold(cred); 1093 fp->f_cred = cred; 1094 } 1095 1096 /* 1097 * Don't allow recycled files to be scanned. 1098 * See uipc_usrreq.c. 1099 */ 1100 if (__predict_false((fp->f_flag & FSCAN) != 0)) { 1101 mutex_enter(&fp->f_lock); 1102 atomic_and_uint(&fp->f_flag, ~FSCAN); 1103 mutex_exit(&fp->f_lock); 1104 } 1105 1106 fp->f_advice = 0; 1107 fp->f_offset = 0; 1108 *resultfp = fp; 1109 1110 return 0; 1111 } 1112 1113 /* 1114 * Successful creation of a new descriptor: make visible to the process. 1115 */ 1116 void 1117 fd_affix(proc_t *p, file_t *fp, unsigned fd) 1118 { 1119 fdfile_t *ff; 1120 filedesc_t *fdp; 1121 1122 KASSERT(p == curproc || p == &proc0); 1123 1124 /* Add a reference to the file structure. */ 1125 mutex_enter(&fp->f_lock); 1126 fp->f_count++; 1127 mutex_exit(&fp->f_lock); 1128 1129 /* 1130 * Insert the new file into the descriptor slot. 1131 * 1132 * The memory barriers provided by lock activity in this routine 1133 * ensure that any updates to the file structure become globally 1134 * visible before the file becomes visible to other LWPs in the 1135 * current process. 1136 */ 1137 fdp = p->p_fd; 1138 ff = fdp->fd_dt->dt_ff[fd]; 1139 1140 KASSERT(ff != NULL); 1141 KASSERT(ff->ff_file == NULL); 1142 KASSERT(ff->ff_allocated); 1143 KASSERT(fd_isused(fdp, fd)); 1144 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1145 1146 /* No need to lock in order to make file initially visible. */ 1147 ff->ff_file = fp; 1148 } 1149 1150 /* 1151 * Abort creation of a new descriptor: free descriptor slot and file. 1152 */ 1153 void 1154 fd_abort(proc_t *p, file_t *fp, unsigned fd) 1155 { 1156 filedesc_t *fdp; 1157 fdfile_t *ff; 1158 1159 KASSERT(p == curproc || p == &proc0); 1160 1161 fdp = p->p_fd; 1162 ff = fdp->fd_dt->dt_ff[fd]; 1163 1164 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1165 1166 mutex_enter(&fdp->fd_lock); 1167 KASSERT(fd_isused(fdp, fd)); 1168 fd_unused(fdp, fd); 1169 mutex_exit(&fdp->fd_lock); 1170 1171 if (fp != NULL) { 1172 KASSERT(fp->f_count == 0); 1173 KASSERT(fp->f_cred != NULL); 1174 pool_cache_put(file_cache, fp); 1175 } 1176 } 1177 1178 static int 1179 file_ctor(void *arg, void *obj, int flags) 1180 { 1181 file_t *fp = obj; 1182 1183 memset(fp, 0, sizeof(*fp)); 1184 1185 mutex_enter(&filelist_lock); 1186 if (__predict_false(nfiles >= maxfiles)) { 1187 mutex_exit(&filelist_lock); 1188 tablefull("file", "increase kern.maxfiles or MAXFILES"); 1189 return ENFILE; 1190 } 1191 nfiles++; 1192 LIST_INSERT_HEAD(&filehead, fp, f_list); 1193 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1194 fp->f_cred = curlwp->l_cred; 1195 kauth_cred_hold(fp->f_cred); 1196 mutex_exit(&filelist_lock); 1197 1198 return 0; 1199 } 1200 1201 static void 1202 file_dtor(void *arg, void *obj) 1203 { 1204 file_t *fp = obj; 1205 1206 mutex_enter(&filelist_lock); 1207 nfiles--; 1208 LIST_REMOVE(fp, f_list); 1209 mutex_exit(&filelist_lock); 1210 1211 kauth_cred_free(fp->f_cred); 1212 mutex_destroy(&fp->f_lock); 1213 } 1214 1215 static int 1216 fdfile_ctor(void *arg, void *obj, int flags) 1217 { 1218 fdfile_t *ff = obj; 1219 1220 memset(ff, 0, sizeof(*ff)); 1221 cv_init(&ff->ff_closing, "fdclose"); 1222 1223 return 0; 1224 } 1225 1226 static void 1227 fdfile_dtor(void *arg, void *obj) 1228 { 1229 fdfile_t *ff = obj; 1230 1231 cv_destroy(&ff->ff_closing); 1232 } 1233 1234 file_t * 1235 fgetdummy(void) 1236 { 1237 file_t *fp; 1238 1239 fp = kmem_zalloc(sizeof(*fp), KM_SLEEP); 1240 if (fp != NULL) { 1241 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1242 } 1243 return fp; 1244 } 1245 1246 void 1247 fputdummy(file_t *fp) 1248 { 1249 1250 mutex_destroy(&fp->f_lock); 1251 kmem_free(fp, sizeof(*fp)); 1252 } 1253 1254 /* 1255 * Create an initial filedesc structure. 1256 */ 1257 filedesc_t * 1258 fd_init(filedesc_t *fdp) 1259 { 1260 #ifdef DIAGNOSTIC 1261 unsigned fd; 1262 #endif 1263 1264 if (__predict_true(fdp == NULL)) { 1265 fdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1266 } else { 1267 KASSERT(fdp == &filedesc0); 1268 filedesc_ctor(NULL, fdp, PR_WAITOK); 1269 } 1270 1271 #ifdef DIAGNOSTIC 1272 KASSERT(fdp->fd_lastfile == -1); 1273 KASSERT(fdp->fd_lastkqfile == -1); 1274 KASSERT(fdp->fd_knhash == NULL); 1275 KASSERT(fdp->fd_freefile == 0); 1276 KASSERT(fdp->fd_exclose == false); 1277 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1278 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1279 for (fd = 0; fd < NDFDFILE; fd++) { 1280 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == 1281 (fdfile_t *)fdp->fd_dfdfile[fd]); 1282 } 1283 for (fd = NDFDFILE; fd < NDFILE; fd++) { 1284 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == NULL); 1285 } 1286 KASSERT(fdp->fd_himap == fdp->fd_dhimap); 1287 KASSERT(fdp->fd_lomap == fdp->fd_dlomap); 1288 #endif /* DIAGNOSTIC */ 1289 1290 fdp->fd_refcnt = 1; 1291 fd_checkmaps(fdp); 1292 1293 return fdp; 1294 } 1295 1296 /* 1297 * Initialize a file descriptor table. 1298 */ 1299 static int 1300 filedesc_ctor(void *arg, void *obj, int flag) 1301 { 1302 filedesc_t *fdp = obj; 1303 fdfile_t **ffp; 1304 int i; 1305 1306 memset(fdp, 0, sizeof(*fdp)); 1307 mutex_init(&fdp->fd_lock, MUTEX_DEFAULT, IPL_NONE); 1308 fdp->fd_lastfile = -1; 1309 fdp->fd_lastkqfile = -1; 1310 fdp->fd_dt = &fdp->fd_dtbuiltin; 1311 fdp->fd_dtbuiltin.dt_nfiles = NDFILE; 1312 fdp->fd_himap = fdp->fd_dhimap; 1313 fdp->fd_lomap = fdp->fd_dlomap; 1314 1315 CTASSERT(sizeof(fdp->fd_dfdfile[0]) >= sizeof(fdfile_t)); 1316 for (i = 0, ffp = fdp->fd_dt->dt_ff; i < NDFDFILE; i++, ffp++) { 1317 *ffp = (fdfile_t *)fdp->fd_dfdfile[i]; 1318 (void)fdfile_ctor(NULL, fdp->fd_dfdfile[i], PR_WAITOK); 1319 } 1320 1321 return 0; 1322 } 1323 1324 static void 1325 filedesc_dtor(void *arg, void *obj) 1326 { 1327 filedesc_t *fdp = obj; 1328 int i; 1329 1330 for (i = 0; i < NDFDFILE; i++) { 1331 fdfile_dtor(NULL, fdp->fd_dfdfile[i]); 1332 } 1333 1334 mutex_destroy(&fdp->fd_lock); 1335 } 1336 1337 /* 1338 * Make p share curproc's filedesc structure. 1339 */ 1340 void 1341 fd_share(struct proc *p) 1342 { 1343 filedesc_t *fdp; 1344 1345 fdp = curlwp->l_fd; 1346 p->p_fd = fdp; 1347 atomic_inc_uint(&fdp->fd_refcnt); 1348 } 1349 1350 /* 1351 * Acquire a hold on a filedesc structure. 1352 */ 1353 void 1354 fd_hold(lwp_t *l) 1355 { 1356 filedesc_t *fdp = l->l_fd; 1357 1358 atomic_inc_uint(&fdp->fd_refcnt); 1359 } 1360 1361 /* 1362 * Copy a filedesc structure. 1363 */ 1364 filedesc_t * 1365 fd_copy(void) 1366 { 1367 filedesc_t *newfdp, *fdp; 1368 fdfile_t *ff, **ffp, **nffp, *ff2; 1369 int i, j, numfiles, lastfile, newlast; 1370 file_t *fp; 1371 fdtab_t *newdt; 1372 1373 fdp = curproc->p_fd; 1374 newfdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1375 newfdp->fd_refcnt = 1; 1376 1377 #ifdef DIAGNOSTIC 1378 KASSERT(newfdp->fd_lastfile == -1); 1379 KASSERT(newfdp->fd_lastkqfile == -1); 1380 KASSERT(newfdp->fd_knhash == NULL); 1381 KASSERT(newfdp->fd_freefile == 0); 1382 KASSERT(newfdp->fd_exclose == false); 1383 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1384 KASSERT(newfdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1385 for (i = 0; i < NDFDFILE; i++) { 1386 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == 1387 (fdfile_t *)&newfdp->fd_dfdfile[i]); 1388 } 1389 for (i = NDFDFILE; i < NDFILE; i++) { 1390 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == NULL); 1391 } 1392 #endif /* DIAGNOSTIC */ 1393 1394 mutex_enter(&fdp->fd_lock); 1395 fd_checkmaps(fdp); 1396 numfiles = fdp->fd_dt->dt_nfiles; 1397 lastfile = fdp->fd_lastfile; 1398 1399 /* 1400 * If the number of open files fits in the internal arrays 1401 * of the open file structure, use them, otherwise allocate 1402 * additional memory for the number of descriptors currently 1403 * in use. 1404 */ 1405 if (lastfile < NDFILE) { 1406 i = NDFILE; 1407 newdt = newfdp->fd_dt; 1408 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1409 } else { 1410 /* 1411 * Compute the smallest multiple of NDEXTENT needed 1412 * for the file descriptors currently in use, 1413 * allowing the table to shrink. 1414 */ 1415 i = numfiles; 1416 while (i >= 2 * NDEXTENT && i > lastfile * 2) { 1417 i /= 2; 1418 } 1419 KASSERT(i > NDFILE); 1420 newdt = fd_dtab_alloc(i); 1421 newfdp->fd_dt = newdt; 1422 memcpy(newdt->dt_ff, newfdp->fd_dtbuiltin.dt_ff, 1423 NDFDFILE * sizeof(fdfile_t **)); 1424 memset(newdt->dt_ff + NDFDFILE, 0, 1425 (i - NDFDFILE) * sizeof(fdfile_t **)); 1426 } 1427 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { 1428 newfdp->fd_himap = newfdp->fd_dhimap; 1429 newfdp->fd_lomap = newfdp->fd_dlomap; 1430 } else { 1431 fd_map_alloc(i, &newfdp->fd_lomap, &newfdp->fd_himap); 1432 KASSERT(i >= NDENTRIES * NDENTRIES); 1433 memset(newfdp->fd_himap, 0, NDHISLOTS(i)*sizeof(uint32_t)); 1434 memset(newfdp->fd_lomap, 0, NDLOSLOTS(i)*sizeof(uint32_t)); 1435 } 1436 newfdp->fd_freefile = fdp->fd_freefile; 1437 newfdp->fd_exclose = fdp->fd_exclose; 1438 1439 ffp = fdp->fd_dt->dt_ff; 1440 nffp = newdt->dt_ff; 1441 newlast = -1; 1442 for (i = 0; i <= (int)lastfile; i++, ffp++, nffp++) { 1443 KASSERT(i >= NDFDFILE || 1444 *nffp == (fdfile_t *)newfdp->fd_dfdfile[i]); 1445 ff = *ffp; 1446 if (ff == NULL || (fp = ff->ff_file) == NULL) { 1447 /* Descriptor unused, or descriptor half open. */ 1448 KASSERT(!fd_isused(newfdp, i)); 1449 continue; 1450 } 1451 if (__predict_false(fp->f_type == DTYPE_KQUEUE)) { 1452 /* kqueue descriptors cannot be copied. */ 1453 if (i < newfdp->fd_freefile) { 1454 newfdp->fd_freefile = i; 1455 } 1456 continue; 1457 } 1458 /* It's active: add a reference to the file. */ 1459 mutex_enter(&fp->f_lock); 1460 fp->f_count++; 1461 mutex_exit(&fp->f_lock); 1462 1463 /* Allocate an fdfile_t to represent it. */ 1464 if (i >= NDFDFILE) { 1465 ff2 = pool_cache_get(fdfile_cache, PR_WAITOK); 1466 *nffp = ff2; 1467 } else { 1468 ff2 = newdt->dt_ff[i]; 1469 } 1470 ff2->ff_file = fp; 1471 ff2->ff_exclose = ff->ff_exclose; 1472 ff2->ff_allocated = true; 1473 1474 /* Fix up bitmaps. */ 1475 j = i >> NDENTRYSHIFT; 1476 KASSERT((newfdp->fd_lomap[j] & (1 << (i & NDENTRYMASK))) == 0); 1477 newfdp->fd_lomap[j] |= 1 << (i & NDENTRYMASK); 1478 if (__predict_false(newfdp->fd_lomap[j] == ~0)) { 1479 KASSERT((newfdp->fd_himap[j >> NDENTRYSHIFT] & 1480 (1 << (j & NDENTRYMASK))) == 0); 1481 newfdp->fd_himap[j >> NDENTRYSHIFT] |= 1482 1 << (j & NDENTRYMASK); 1483 } 1484 newlast = i; 1485 } 1486 KASSERT(newdt->dt_ff[0] == (fdfile_t *)newfdp->fd_dfdfile[0]); 1487 newfdp->fd_lastfile = newlast; 1488 fd_checkmaps(newfdp); 1489 mutex_exit(&fdp->fd_lock); 1490 1491 return newfdp; 1492 } 1493 1494 /* 1495 * Release a filedesc structure. 1496 */ 1497 void 1498 fd_free(void) 1499 { 1500 fdfile_t *ff; 1501 file_t *fp; 1502 int fd, nf; 1503 fdtab_t *dt; 1504 lwp_t * const l = curlwp; 1505 filedesc_t * const fdp = l->l_fd; 1506 const bool noadvlock = (l->l_proc->p_flag & PK_ADVLOCK) == 0; 1507 1508 KASSERT(fdp->fd_dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1509 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1510 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1511 1512 #ifndef __HAVE_ATOMIC_AS_MEMBAR 1513 membar_exit(); 1514 #endif 1515 if (atomic_dec_uint_nv(&fdp->fd_refcnt) > 0) 1516 return; 1517 1518 /* 1519 * Close any files that the process holds open. 1520 */ 1521 dt = fdp->fd_dt; 1522 fd_checkmaps(fdp); 1523 #ifdef DEBUG 1524 fdp->fd_refcnt = -1; /* see fd_checkmaps */ 1525 #endif 1526 for (fd = 0, nf = dt->dt_nfiles; fd < nf; fd++) { 1527 ff = dt->dt_ff[fd]; 1528 KASSERT(fd >= NDFDFILE || 1529 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1530 if (ff == NULL) 1531 continue; 1532 if ((fp = ff->ff_file) != NULL) { 1533 /* 1534 * Must use fd_close() here if there is 1535 * a reference from kqueue or we might have posix 1536 * advisory locks. 1537 */ 1538 if (__predict_true(ff->ff_refcnt == 0) && 1539 (noadvlock || fp->f_type != DTYPE_VNODE)) { 1540 ff->ff_file = NULL; 1541 ff->ff_exclose = false; 1542 ff->ff_allocated = false; 1543 closef(fp); 1544 } else { 1545 ff->ff_refcnt++; 1546 fd_close(fd); 1547 } 1548 } 1549 KASSERT(ff->ff_refcnt == 0); 1550 KASSERT(ff->ff_file == NULL); 1551 KASSERT(!ff->ff_exclose); 1552 KASSERT(!ff->ff_allocated); 1553 if (fd >= NDFDFILE) { 1554 pool_cache_put(fdfile_cache, ff); 1555 dt->dt_ff[fd] = NULL; 1556 } 1557 } 1558 1559 /* 1560 * Clean out the descriptor table for the next user and return 1561 * to the cache. 1562 */ 1563 if (__predict_false(dt != &fdp->fd_dtbuiltin)) { 1564 fd_dtab_free(fdp->fd_dt); 1565 /* Otherwise, done above. */ 1566 memset(&fdp->fd_dtbuiltin.dt_ff[NDFDFILE], 0, 1567 (NDFILE - NDFDFILE) * sizeof(fdp->fd_dtbuiltin.dt_ff[0])); 1568 fdp->fd_dt = &fdp->fd_dtbuiltin; 1569 } 1570 if (__predict_false(NDHISLOTS(nf) > NDHISLOTS(NDFILE))) { 1571 KASSERT(fdp->fd_himap != fdp->fd_dhimap); 1572 KASSERT(fdp->fd_lomap != fdp->fd_dlomap); 1573 fd_map_free(nf, fdp->fd_lomap, fdp->fd_himap); 1574 } 1575 if (__predict_false(fdp->fd_knhash != NULL)) { 1576 hashdone(fdp->fd_knhash, HASH_LIST, fdp->fd_knhashmask); 1577 fdp->fd_knhash = NULL; 1578 fdp->fd_knhashmask = 0; 1579 } else { 1580 KASSERT(fdp->fd_knhashmask == 0); 1581 } 1582 fdp->fd_dt = &fdp->fd_dtbuiltin; 1583 fdp->fd_lastkqfile = -1; 1584 fdp->fd_lastfile = -1; 1585 fdp->fd_freefile = 0; 1586 fdp->fd_exclose = false; 1587 memset(&fdp->fd_startzero, 0, sizeof(*fdp) - 1588 offsetof(filedesc_t, fd_startzero)); 1589 fdp->fd_himap = fdp->fd_dhimap; 1590 fdp->fd_lomap = fdp->fd_dlomap; 1591 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1592 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1593 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1594 #ifdef DEBUG 1595 fdp->fd_refcnt = 0; /* see fd_checkmaps */ 1596 #endif 1597 fd_checkmaps(fdp); 1598 pool_cache_put(filedesc_cache, fdp); 1599 } 1600 1601 /* 1602 * File Descriptor pseudo-device driver (/dev/fd/). 1603 * 1604 * Opening minor device N dup()s the file (if any) connected to file 1605 * descriptor N belonging to the calling process. Note that this driver 1606 * consists of only the ``open()'' routine, because all subsequent 1607 * references to this file will be direct to the other driver. 1608 */ 1609 static int 1610 filedescopen(dev_t dev, int mode, int type, lwp_t *l) 1611 { 1612 1613 /* 1614 * XXX Kludge: set dupfd to contain the value of the 1615 * the file descriptor being sought for duplication. The error 1616 * return ensures that the vnode for this device will be released 1617 * by vn_open. Open will detect this special error and take the 1618 * actions in fd_dupopen below. Other callers of vn_open or VOP_OPEN 1619 * will simply report the error. 1620 */ 1621 l->l_dupfd = minor(dev); /* XXX */ 1622 return EDUPFD; 1623 } 1624 1625 /* 1626 * Duplicate the specified descriptor to a free descriptor. 1627 */ 1628 int 1629 fd_dupopen(int old, int *new, int mode, int error) 1630 { 1631 filedesc_t *fdp; 1632 fdfile_t *ff; 1633 file_t *fp; 1634 fdtab_t *dt; 1635 1636 if ((fp = fd_getfile(old)) == NULL) { 1637 return EBADF; 1638 } 1639 fdp = curlwp->l_fd; 1640 dt = fdp->fd_dt; 1641 ff = dt->dt_ff[old]; 1642 1643 /* 1644 * There are two cases of interest here. 1645 * 1646 * For EDUPFD simply dup (old) to file descriptor 1647 * (new) and return. 1648 * 1649 * For EMOVEFD steal away the file structure from (old) and 1650 * store it in (new). (old) is effectively closed by 1651 * this operation. 1652 * 1653 * Any other error code is just returned. 1654 */ 1655 switch (error) { 1656 case EDUPFD: 1657 /* 1658 * Check that the mode the file is being opened for is a 1659 * subset of the mode of the existing descriptor. 1660 */ 1661 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 1662 error = EACCES; 1663 break; 1664 } 1665 1666 /* Copy it. */ 1667 error = fd_dup(fp, 0, new, ff->ff_exclose); 1668 break; 1669 1670 case EMOVEFD: 1671 /* Copy it. */ 1672 error = fd_dup(fp, 0, new, ff->ff_exclose); 1673 if (error != 0) { 1674 break; 1675 } 1676 1677 /* Steal away the file pointer from 'old'. */ 1678 (void)fd_close(old); 1679 return 0; 1680 } 1681 1682 fd_putfile(old); 1683 return error; 1684 } 1685 1686 /* 1687 * Close open files on exec. 1688 */ 1689 void 1690 fd_closeexec(void) 1691 { 1692 proc_t *p; 1693 filedesc_t *fdp; 1694 fdfile_t *ff; 1695 lwp_t *l; 1696 fdtab_t *dt; 1697 int fd; 1698 1699 l = curlwp; 1700 p = l->l_proc; 1701 fdp = p->p_fd; 1702 1703 if (fdp->fd_refcnt > 1) { 1704 fdp = fd_copy(); 1705 fd_free(); 1706 p->p_fd = fdp; 1707 l->l_fd = fdp; 1708 } 1709 if (!fdp->fd_exclose) { 1710 return; 1711 } 1712 fdp->fd_exclose = false; 1713 dt = fdp->fd_dt; 1714 1715 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 1716 if ((ff = dt->dt_ff[fd]) == NULL) { 1717 KASSERT(fd >= NDFDFILE); 1718 continue; 1719 } 1720 KASSERT(fd >= NDFDFILE || 1721 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1722 if (ff->ff_file == NULL) 1723 continue; 1724 if (ff->ff_exclose) { 1725 /* 1726 * We need a reference to close the file. 1727 * No other threads can see the fdfile_t at 1728 * this point, so don't bother locking. 1729 */ 1730 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 1731 ff->ff_refcnt++; 1732 fd_close(fd); 1733 } 1734 } 1735 } 1736 1737 /* 1738 * Sets descriptor owner. If the owner is a process, 'pgid' 1739 * is set to positive value, process ID. If the owner is process group, 1740 * 'pgid' is set to -pg_id. 1741 */ 1742 int 1743 fsetown(pid_t *pgid, u_long cmd, const void *data) 1744 { 1745 pid_t id = *(const pid_t *)data; 1746 int error; 1747 1748 switch (cmd) { 1749 case TIOCSPGRP: 1750 if (id < 0) 1751 return EINVAL; 1752 id = -id; 1753 break; 1754 default: 1755 break; 1756 } 1757 if (id > 0) { 1758 mutex_enter(proc_lock); 1759 error = proc_find(id) ? 0 : ESRCH; 1760 mutex_exit(proc_lock); 1761 } else if (id < 0) { 1762 error = pgid_in_session(curproc, -id); 1763 } else { 1764 error = 0; 1765 } 1766 if (!error) { 1767 *pgid = id; 1768 } 1769 return error; 1770 } 1771 1772 void 1773 fd_set_exclose(struct lwp *l, int fd, bool exclose) 1774 { 1775 filedesc_t *fdp = l->l_fd; 1776 fdfile_t *ff = fdp->fd_dt->dt_ff[fd]; 1777 1778 ff->ff_exclose = exclose; 1779 if (exclose) 1780 fdp->fd_exclose = true; 1781 } 1782 1783 /* 1784 * Return descriptor owner information. If the value is positive, 1785 * it's process ID. If it's negative, it's process group ID and 1786 * needs the sign removed before use. 1787 */ 1788 int 1789 fgetown(pid_t pgid, u_long cmd, void *data) 1790 { 1791 1792 switch (cmd) { 1793 case TIOCGPGRP: 1794 *(int *)data = -pgid; 1795 break; 1796 default: 1797 *(int *)data = pgid; 1798 break; 1799 } 1800 return 0; 1801 } 1802 1803 /* 1804 * Send signal to descriptor owner, either process or process group. 1805 */ 1806 void 1807 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) 1808 { 1809 ksiginfo_t ksi; 1810 1811 KASSERT(!cpu_intr_p()); 1812 1813 if (pgid == 0) { 1814 return; 1815 } 1816 1817 KSI_INIT(&ksi); 1818 ksi.ksi_signo = signo; 1819 ksi.ksi_code = code; 1820 ksi.ksi_band = band; 1821 1822 mutex_enter(proc_lock); 1823 if (pgid > 0) { 1824 struct proc *p1; 1825 1826 p1 = proc_find(pgid); 1827 if (p1 != NULL) { 1828 kpsignal(p1, &ksi, fdescdata); 1829 } 1830 } else { 1831 struct pgrp *pgrp; 1832 1833 KASSERT(pgid < 0); 1834 pgrp = pgrp_find(-pgid); 1835 if (pgrp != NULL) { 1836 kpgsignal(pgrp, &ksi, fdescdata, 0); 1837 } 1838 } 1839 mutex_exit(proc_lock); 1840 } 1841 1842 int 1843 fd_clone(file_t *fp, unsigned fd, int flag, const struct fileops *fops, 1844 void *data) 1845 { 1846 1847 fp->f_flag = flag; 1848 fp->f_type = DTYPE_MISC; 1849 fp->f_ops = fops; 1850 fp->f_data = data; 1851 curlwp->l_dupfd = fd; 1852 fd_affix(curproc, fp, fd); 1853 1854 return EMOVEFD; 1855 } 1856 1857 int 1858 fnullop_fcntl(file_t *fp, u_int cmd, void *data) 1859 { 1860 1861 if (cmd == F_SETFL) 1862 return 0; 1863 1864 return EOPNOTSUPP; 1865 } 1866 1867 int 1868 fnullop_poll(file_t *fp, int which) 1869 { 1870 1871 return 0; 1872 } 1873 1874 int 1875 fnullop_kqfilter(file_t *fp, struct knote *kn) 1876 { 1877 1878 return 0; 1879 } 1880 1881 void 1882 fnullop_restart(file_t *fp) 1883 { 1884 1885 } 1886 1887 int 1888 fbadop_read(file_t *fp, off_t *offset, struct uio *uio, 1889 kauth_cred_t cred, int flags) 1890 { 1891 1892 return EOPNOTSUPP; 1893 } 1894 1895 int 1896 fbadop_write(file_t *fp, off_t *offset, struct uio *uio, 1897 kauth_cred_t cred, int flags) 1898 { 1899 1900 return EOPNOTSUPP; 1901 } 1902 1903 int 1904 fbadop_ioctl(file_t *fp, u_long com, void *data) 1905 { 1906 1907 return EOPNOTSUPP; 1908 } 1909 1910 int 1911 fbadop_stat(file_t *fp, struct stat *sb) 1912 { 1913 1914 return EOPNOTSUPP; 1915 } 1916 1917 int 1918 fbadop_close(file_t *fp) 1919 { 1920 1921 return EOPNOTSUPP; 1922 } 1923 1924 /* 1925 * sysctl routines pertaining to file descriptors 1926 */ 1927 1928 /* Initialized in sysctl_init() for now... */ 1929 extern kmutex_t sysctl_file_marker_lock; 1930 static u_int sysctl_file_marker = 1; 1931 1932 /* 1933 * Expects to be called with proc_lock and sysctl_file_marker_lock locked. 1934 */ 1935 static void 1936 sysctl_file_marker_reset(void) 1937 { 1938 struct proc *p; 1939 1940 PROCLIST_FOREACH(p, &allproc) { 1941 struct filedesc *fd = p->p_fd; 1942 fdtab_t *dt; 1943 u_int i; 1944 1945 mutex_enter(&fd->fd_lock); 1946 dt = fd->fd_dt; 1947 for (i = 0; i < dt->dt_nfiles; i++) { 1948 struct file *fp; 1949 fdfile_t *ff; 1950 1951 if ((ff = dt->dt_ff[i]) == NULL) { 1952 continue; 1953 } 1954 if ((fp = ff->ff_file) == NULL) { 1955 continue; 1956 } 1957 fp->f_marker = 0; 1958 } 1959 mutex_exit(&fd->fd_lock); 1960 } 1961 } 1962 1963 /* 1964 * sysctl helper routine for kern.file pseudo-subtree. 1965 */ 1966 static int 1967 sysctl_kern_file(SYSCTLFN_ARGS) 1968 { 1969 int error; 1970 size_t buflen; 1971 struct file *fp, fbuf; 1972 char *start, *where; 1973 struct proc *p; 1974 1975 start = where = oldp; 1976 buflen = *oldlenp; 1977 1978 if (where == NULL) { 1979 /* 1980 * overestimate by 10 files 1981 */ 1982 *oldlenp = sizeof(filehead) + (nfiles + 10) * 1983 sizeof(struct file); 1984 return 0; 1985 } 1986 1987 /* 1988 * first sysctl_copyout filehead 1989 */ 1990 if (buflen < sizeof(filehead)) { 1991 *oldlenp = 0; 1992 return 0; 1993 } 1994 sysctl_unlock(); 1995 error = sysctl_copyout(l, &filehead, where, sizeof(filehead)); 1996 if (error) { 1997 sysctl_relock(); 1998 return error; 1999 } 2000 buflen -= sizeof(filehead); 2001 where += sizeof(filehead); 2002 2003 /* 2004 * followed by an array of file structures 2005 */ 2006 mutex_enter(&sysctl_file_marker_lock); 2007 mutex_enter(proc_lock); 2008 PROCLIST_FOREACH(p, &allproc) { 2009 struct filedesc *fd; 2010 fdtab_t *dt; 2011 u_int i; 2012 2013 if (p->p_stat == SIDL) { 2014 /* skip embryonic processes */ 2015 continue; 2016 } 2017 mutex_enter(p->p_lock); 2018 error = kauth_authorize_process(l->l_cred, 2019 KAUTH_PROCESS_CANSEE, p, 2020 KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), 2021 NULL, NULL); 2022 mutex_exit(p->p_lock); 2023 if (error != 0) { 2024 /* 2025 * Don't leak kauth retval if we're silently 2026 * skipping this entry. 2027 */ 2028 error = 0; 2029 continue; 2030 } 2031 2032 /* 2033 * Grab a hold on the process. 2034 */ 2035 if (!rw_tryenter(&p->p_reflock, RW_READER)) { 2036 continue; 2037 } 2038 mutex_exit(proc_lock); 2039 2040 fd = p->p_fd; 2041 mutex_enter(&fd->fd_lock); 2042 dt = fd->fd_dt; 2043 for (i = 0; i < dt->dt_nfiles; i++) { 2044 fdfile_t *ff; 2045 2046 if ((ff = dt->dt_ff[i]) == NULL) { 2047 continue; 2048 } 2049 if ((fp = ff->ff_file) == NULL) { 2050 continue; 2051 } 2052 2053 mutex_enter(&fp->f_lock); 2054 2055 if ((fp->f_count == 0) || 2056 (fp->f_marker == sysctl_file_marker)) { 2057 mutex_exit(&fp->f_lock); 2058 continue; 2059 } 2060 2061 /* Check that we have enough space. */ 2062 if (buflen < sizeof(struct file)) { 2063 *oldlenp = where - start; 2064 mutex_exit(&fp->f_lock); 2065 error = ENOMEM; 2066 break; 2067 } 2068 2069 memcpy(&fbuf, fp, sizeof(fbuf)); 2070 mutex_exit(&fp->f_lock); 2071 error = sysctl_copyout(l, &fbuf, where, sizeof(fbuf)); 2072 if (error) { 2073 break; 2074 } 2075 buflen -= sizeof(struct file); 2076 where += sizeof(struct file); 2077 2078 fp->f_marker = sysctl_file_marker; 2079 } 2080 mutex_exit(&fd->fd_lock); 2081 2082 /* 2083 * Release reference to process. 2084 */ 2085 mutex_enter(proc_lock); 2086 rw_exit(&p->p_reflock); 2087 2088 if (error) 2089 break; 2090 } 2091 2092 sysctl_file_marker++; 2093 /* Reset all markers if wrapped. */ 2094 if (sysctl_file_marker == 0) { 2095 sysctl_file_marker_reset(); 2096 sysctl_file_marker++; 2097 } 2098 2099 mutex_exit(proc_lock); 2100 mutex_exit(&sysctl_file_marker_lock); 2101 2102 *oldlenp = where - start; 2103 sysctl_relock(); 2104 return error; 2105 } 2106 2107 /* 2108 * sysctl helper function for kern.file2 2109 */ 2110 static int 2111 sysctl_kern_file2(SYSCTLFN_ARGS) 2112 { 2113 struct proc *p; 2114 struct file *fp; 2115 struct filedesc *fd; 2116 struct kinfo_file kf; 2117 char *dp; 2118 u_int i, op; 2119 size_t len, needed, elem_size, out_size; 2120 int error, arg, elem_count; 2121 fdfile_t *ff; 2122 fdtab_t *dt; 2123 2124 if (namelen == 1 && name[0] == CTL_QUERY) 2125 return sysctl_query(SYSCTLFN_CALL(rnode)); 2126 2127 if (namelen != 4) 2128 return EINVAL; 2129 2130 error = 0; 2131 dp = oldp; 2132 len = (oldp != NULL) ? *oldlenp : 0; 2133 op = name[0]; 2134 arg = name[1]; 2135 elem_size = name[2]; 2136 elem_count = name[3]; 2137 out_size = MIN(sizeof(kf), elem_size); 2138 needed = 0; 2139 2140 if (elem_size < 1 || elem_count < 0) 2141 return EINVAL; 2142 2143 switch (op) { 2144 case KERN_FILE_BYFILE: 2145 case KERN_FILE_BYPID: 2146 /* 2147 * We're traversing the process list in both cases; the BYFILE 2148 * case does additional work of keeping track of files already 2149 * looked at. 2150 */ 2151 2152 /* doesn't use arg so it must be zero */ 2153 if ((op == KERN_FILE_BYFILE) && (arg != 0)) 2154 return EINVAL; 2155 2156 if ((op == KERN_FILE_BYPID) && (arg < -1)) 2157 /* -1 means all processes */ 2158 return EINVAL; 2159 2160 sysctl_unlock(); 2161 if (op == KERN_FILE_BYFILE) 2162 mutex_enter(&sysctl_file_marker_lock); 2163 mutex_enter(proc_lock); 2164 PROCLIST_FOREACH(p, &allproc) { 2165 if (p->p_stat == SIDL) { 2166 /* skip embryonic processes */ 2167 continue; 2168 } 2169 if (arg > 0 && p->p_pid != arg) { 2170 /* pick only the one we want */ 2171 /* XXX want 0 to mean "kernel files" */ 2172 continue; 2173 } 2174 mutex_enter(p->p_lock); 2175 error = kauth_authorize_process(l->l_cred, 2176 KAUTH_PROCESS_CANSEE, p, 2177 KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), 2178 NULL, NULL); 2179 mutex_exit(p->p_lock); 2180 if (error != 0) { 2181 /* 2182 * Don't leak kauth retval if we're silently 2183 * skipping this entry. 2184 */ 2185 error = 0; 2186 continue; 2187 } 2188 2189 /* 2190 * Grab a hold on the process. 2191 */ 2192 if (!rw_tryenter(&p->p_reflock, RW_READER)) { 2193 continue; 2194 } 2195 mutex_exit(proc_lock); 2196 2197 fd = p->p_fd; 2198 mutex_enter(&fd->fd_lock); 2199 dt = fd->fd_dt; 2200 for (i = 0; i < dt->dt_nfiles; i++) { 2201 if ((ff = dt->dt_ff[i]) == NULL) { 2202 continue; 2203 } 2204 if ((fp = ff->ff_file) == NULL) { 2205 continue; 2206 } 2207 2208 if ((op == KERN_FILE_BYFILE) && 2209 (fp->f_marker == sysctl_file_marker)) { 2210 continue; 2211 } 2212 if (len >= elem_size && elem_count > 0) { 2213 mutex_enter(&fp->f_lock); 2214 fill_file(&kf, fp, ff, i, p->p_pid); 2215 mutex_exit(&fp->f_lock); 2216 mutex_exit(&fd->fd_lock); 2217 error = sysctl_copyout(l, 2218 &kf, dp, out_size); 2219 mutex_enter(&fd->fd_lock); 2220 if (error) 2221 break; 2222 dp += elem_size; 2223 len -= elem_size; 2224 } 2225 if (op == KERN_FILE_BYFILE) 2226 fp->f_marker = sysctl_file_marker; 2227 needed += elem_size; 2228 if (elem_count > 0 && elem_count != INT_MAX) 2229 elem_count--; 2230 } 2231 mutex_exit(&fd->fd_lock); 2232 2233 /* 2234 * Release reference to process. 2235 */ 2236 mutex_enter(proc_lock); 2237 rw_exit(&p->p_reflock); 2238 } 2239 if (op == KERN_FILE_BYFILE) { 2240 sysctl_file_marker++; 2241 2242 /* Reset all markers if wrapped. */ 2243 if (sysctl_file_marker == 0) { 2244 sysctl_file_marker_reset(); 2245 sysctl_file_marker++; 2246 } 2247 } 2248 mutex_exit(proc_lock); 2249 if (op == KERN_FILE_BYFILE) 2250 mutex_exit(&sysctl_file_marker_lock); 2251 sysctl_relock(); 2252 break; 2253 default: 2254 return EINVAL; 2255 } 2256 2257 if (oldp == NULL) 2258 needed += KERN_FILESLOP * elem_size; 2259 *oldlenp = needed; 2260 2261 return error; 2262 } 2263 2264 static void 2265 fill_file(struct kinfo_file *kp, const file_t *fp, const fdfile_t *ff, 2266 int i, pid_t pid) 2267 { 2268 2269 memset(kp, 0, sizeof(*kp)); 2270 2271 kp->ki_fileaddr = PTRTOUINT64(fp); 2272 kp->ki_flag = fp->f_flag; 2273 kp->ki_iflags = 0; 2274 kp->ki_ftype = fp->f_type; 2275 kp->ki_count = fp->f_count; 2276 kp->ki_msgcount = fp->f_msgcount; 2277 kp->ki_fucred = PTRTOUINT64(fp->f_cred); 2278 kp->ki_fuid = kauth_cred_geteuid(fp->f_cred); 2279 kp->ki_fgid = kauth_cred_getegid(fp->f_cred); 2280 kp->ki_fops = PTRTOUINT64(fp->f_ops); 2281 kp->ki_foffset = fp->f_offset; 2282 kp->ki_fdata = PTRTOUINT64(fp->f_data); 2283 2284 /* vnode information to glue this file to something */ 2285 if (fp->f_type == DTYPE_VNODE) { 2286 struct vnode *vp = (struct vnode *)fp->f_data; 2287 2288 kp->ki_vun = PTRTOUINT64(vp->v_un.vu_socket); 2289 kp->ki_vsize = vp->v_size; 2290 kp->ki_vtype = vp->v_type; 2291 kp->ki_vtag = vp->v_tag; 2292 kp->ki_vdata = PTRTOUINT64(vp->v_data); 2293 } 2294 2295 /* process information when retrieved via KERN_FILE_BYPID */ 2296 if (ff != NULL) { 2297 kp->ki_pid = pid; 2298 kp->ki_fd = i; 2299 kp->ki_ofileflags = ff->ff_exclose; 2300 kp->ki_usecount = ff->ff_refcnt; 2301 } 2302 } 2303