1 /* $NetBSD: kern_descrip.c,v 1.211 2011/02/15 15:54:28 pooka 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 1.211 2011/02/15 15:54:28 pooka 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 static int file_ctor(void *, void *, int); 101 static void file_dtor(void *, void *); 102 static int fdfile_ctor(void *, void *, int); 103 static void fdfile_dtor(void *, void *); 104 static int filedesc_ctor(void *, void *, int); 105 static void filedesc_dtor(void *, void *); 106 static int filedescopen(dev_t, int, int, lwp_t *); 107 108 static int sysctl_kern_file(SYSCTLFN_PROTO); 109 static int sysctl_kern_file2(SYSCTLFN_PROTO); 110 static void fill_file(struct kinfo_file *, const file_t *, const fdfile_t *, 111 int, pid_t); 112 113 kmutex_t filelist_lock; /* lock on filehead */ 114 struct filelist filehead; /* head of list of open files */ 115 u_int nfiles; /* actual number of open files */ 116 117 static pool_cache_t filedesc_cache; 118 static pool_cache_t file_cache; 119 static pool_cache_t fdfile_cache; 120 121 const struct cdevsw filedesc_cdevsw = { 122 filedescopen, noclose, noread, nowrite, noioctl, 123 nostop, notty, nopoll, nommap, nokqfilter, D_OTHER | D_MPSAFE, 124 }; 125 126 /* For ease of reading. */ 127 __strong_alias(fd_putvnode,fd_putfile) 128 __strong_alias(fd_putsock,fd_putfile) 129 130 /* 131 * Initialize the descriptor system. 132 */ 133 void 134 fd_sys_init(void) 135 { 136 static struct sysctllog *clog; 137 138 mutex_init(&filelist_lock, MUTEX_DEFAULT, IPL_NONE); 139 140 file_cache = pool_cache_init(sizeof(file_t), coherency_unit, 0, 141 0, "file", NULL, IPL_NONE, file_ctor, file_dtor, NULL); 142 KASSERT(file_cache != NULL); 143 144 fdfile_cache = pool_cache_init(sizeof(fdfile_t), coherency_unit, 0, 145 PR_LARGECACHE, "fdfile", NULL, IPL_NONE, fdfile_ctor, fdfile_dtor, 146 NULL); 147 KASSERT(fdfile_cache != NULL); 148 149 filedesc_cache = pool_cache_init(sizeof(filedesc_t), coherency_unit, 150 0, 0, "filedesc", NULL, IPL_NONE, filedesc_ctor, filedesc_dtor, 151 NULL); 152 KASSERT(filedesc_cache != NULL); 153 154 sysctl_createv(&clog, 0, NULL, NULL, 155 CTLFLAG_PERMANENT, CTLTYPE_NODE, "kern", NULL, 156 NULL, 0, NULL, 0, CTL_KERN, CTL_EOL); 157 sysctl_createv(&clog, 0, NULL, NULL, 158 CTLFLAG_PERMANENT, 159 CTLTYPE_STRUCT, "file", 160 SYSCTL_DESCR("System open file table"), 161 sysctl_kern_file, 0, NULL, 0, 162 CTL_KERN, KERN_FILE, CTL_EOL); 163 sysctl_createv(&clog, 0, NULL, NULL, 164 CTLFLAG_PERMANENT, 165 CTLTYPE_STRUCT, "file2", 166 SYSCTL_DESCR("System open file table"), 167 sysctl_kern_file2, 0, NULL, 0, 168 CTL_KERN, KERN_FILE2, CTL_EOL); 169 } 170 171 static bool 172 fd_isused(filedesc_t *fdp, unsigned fd) 173 { 174 u_int off = fd >> NDENTRYSHIFT; 175 176 KASSERT(fd < fdp->fd_dt->dt_nfiles); 177 178 return (fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0; 179 } 180 181 /* 182 * Verify that the bitmaps match the descriptor table. 183 */ 184 static inline void 185 fd_checkmaps(filedesc_t *fdp) 186 { 187 #ifdef DEBUG 188 fdtab_t *dt; 189 u_int fd; 190 191 dt = fdp->fd_dt; 192 if (fdp->fd_refcnt == -1) { 193 /* 194 * fd_free tears down the table without maintaining its bitmap. 195 */ 196 return; 197 } 198 for (fd = 0; fd < dt->dt_nfiles; fd++) { 199 if (fd < NDFDFILE) { 200 KASSERT(dt->dt_ff[fd] == 201 (fdfile_t *)fdp->fd_dfdfile[fd]); 202 } 203 if (dt->dt_ff[fd] == NULL) { 204 KASSERT(!fd_isused(fdp, fd)); 205 } else if (dt->dt_ff[fd]->ff_file != NULL) { 206 KASSERT(fd_isused(fdp, fd)); 207 } 208 } 209 #else /* DEBUG */ 210 /* nothing */ 211 #endif /* DEBUG */ 212 } 213 214 static int 215 fd_next_zero(filedesc_t *fdp, uint32_t *bitmap, int want, u_int bits) 216 { 217 int i, off, maxoff; 218 uint32_t sub; 219 220 KASSERT(mutex_owned(&fdp->fd_lock)); 221 222 fd_checkmaps(fdp); 223 224 if (want > bits) 225 return -1; 226 227 off = want >> NDENTRYSHIFT; 228 i = want & NDENTRYMASK; 229 if (i) { 230 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); 231 if (sub != ~0) 232 goto found; 233 off++; 234 } 235 236 maxoff = NDLOSLOTS(bits); 237 while (off < maxoff) { 238 if ((sub = bitmap[off]) != ~0) 239 goto found; 240 off++; 241 } 242 243 return (-1); 244 245 found: 246 return (off << NDENTRYSHIFT) + ffs(~sub) - 1; 247 } 248 249 static int 250 fd_last_set(filedesc_t *fd, int last) 251 { 252 int off, i; 253 fdfile_t **ff = fd->fd_dt->dt_ff; 254 uint32_t *bitmap = fd->fd_lomap; 255 256 KASSERT(mutex_owned(&fd->fd_lock)); 257 258 fd_checkmaps(fd); 259 260 off = (last - 1) >> NDENTRYSHIFT; 261 262 while (off >= 0 && !bitmap[off]) 263 off--; 264 265 if (off < 0) 266 return (-1); 267 268 i = ((off + 1) << NDENTRYSHIFT) - 1; 269 if (i >= last) 270 i = last - 1; 271 272 /* XXX should use bitmap */ 273 while (i > 0 && (ff[i] == NULL || !ff[i]->ff_allocated)) 274 i--; 275 276 return (i); 277 } 278 279 static inline void 280 fd_used(filedesc_t *fdp, unsigned fd) 281 { 282 u_int off = fd >> NDENTRYSHIFT; 283 fdfile_t *ff; 284 285 ff = fdp->fd_dt->dt_ff[fd]; 286 287 KASSERT(mutex_owned(&fdp->fd_lock)); 288 KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) == 0); 289 KASSERT(ff != NULL); 290 KASSERT(ff->ff_file == NULL); 291 KASSERT(!ff->ff_allocated); 292 293 ff->ff_allocated = 1; 294 fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK); 295 if (__predict_false(fdp->fd_lomap[off] == ~0)) { 296 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 297 (1 << (off & NDENTRYMASK))) == 0); 298 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK); 299 } 300 301 if ((int)fd > fdp->fd_lastfile) { 302 fdp->fd_lastfile = fd; 303 } 304 305 fd_checkmaps(fdp); 306 } 307 308 static inline void 309 fd_unused(filedesc_t *fdp, unsigned fd) 310 { 311 u_int off = fd >> NDENTRYSHIFT; 312 fdfile_t *ff; 313 314 ff = fdp->fd_dt->dt_ff[fd]; 315 316 /* 317 * Don't assert the lock is held here, as we may be copying 318 * the table during exec() and it is not needed there. 319 * procfs and sysctl are locked out by proc::p_reflock. 320 * 321 * KASSERT(mutex_owned(&fdp->fd_lock)); 322 */ 323 KASSERT(ff != NULL); 324 KASSERT(ff->ff_file == NULL); 325 KASSERT(ff->ff_allocated); 326 327 if (fd < fdp->fd_freefile) { 328 fdp->fd_freefile = fd; 329 } 330 331 if (fdp->fd_lomap[off] == ~0) { 332 KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 333 (1 << (off & NDENTRYMASK))) != 0); 334 fdp->fd_himap[off >> NDENTRYSHIFT] &= 335 ~(1 << (off & NDENTRYMASK)); 336 } 337 KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0); 338 fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK)); 339 ff->ff_allocated = 0; 340 341 KASSERT(fd <= fdp->fd_lastfile); 342 if (fd == fdp->fd_lastfile) { 343 fdp->fd_lastfile = fd_last_set(fdp, fd); 344 } 345 fd_checkmaps(fdp); 346 } 347 348 /* 349 * Look up the file structure corresponding to a file descriptor 350 * and return the file, holding a reference on the descriptor. 351 */ 352 inline file_t * 353 fd_getfile(unsigned fd) 354 { 355 filedesc_t *fdp; 356 fdfile_t *ff; 357 file_t *fp; 358 fdtab_t *dt; 359 360 /* 361 * Look up the fdfile structure representing this descriptor. 362 * We are doing this unlocked. See fd_tryexpand(). 363 */ 364 fdp = curlwp->l_fd; 365 dt = fdp->fd_dt; 366 if (__predict_false(fd >= dt->dt_nfiles)) { 367 return NULL; 368 } 369 ff = dt->dt_ff[fd]; 370 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 371 if (__predict_false(ff == NULL)) { 372 return NULL; 373 } 374 375 /* Now get a reference to the descriptor. */ 376 if (fdp->fd_refcnt == 1) { 377 /* 378 * Single threaded: don't need to worry about concurrent 379 * access (other than earlier calls to kqueue, which may 380 * hold a reference to the descriptor). 381 */ 382 ff->ff_refcnt++; 383 } else { 384 /* 385 * Multi threaded: issue a memory barrier to ensure that we 386 * acquire the file pointer _after_ adding a reference. If 387 * no memory barrier, we could fetch a stale pointer. 388 */ 389 atomic_inc_uint(&ff->ff_refcnt); 390 #ifndef __HAVE_ATOMIC_AS_MEMBAR 391 membar_enter(); 392 #endif 393 } 394 395 /* 396 * If the file is not open or is being closed then put the 397 * reference back. 398 */ 399 fp = ff->ff_file; 400 if (__predict_true(fp != NULL)) { 401 return fp; 402 } 403 fd_putfile(fd); 404 return NULL; 405 } 406 407 /* 408 * Release a reference to a file descriptor acquired with fd_getfile(). 409 */ 410 void 411 fd_putfile(unsigned fd) 412 { 413 filedesc_t *fdp; 414 fdfile_t *ff; 415 u_int u, v; 416 417 fdp = curlwp->l_fd; 418 ff = fdp->fd_dt->dt_ff[fd]; 419 420 KASSERT(fd < fdp->fd_dt->dt_nfiles); 421 KASSERT(ff != NULL); 422 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 423 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 424 425 if (fdp->fd_refcnt == 1) { 426 /* 427 * Single threaded: don't need to worry about concurrent 428 * access (other than earlier calls to kqueue, which may 429 * hold a reference to the descriptor). 430 */ 431 if (__predict_false((ff->ff_refcnt & FR_CLOSING) != 0)) { 432 fd_close(fd); 433 return; 434 } 435 ff->ff_refcnt--; 436 return; 437 } 438 439 /* 440 * Ensure that any use of the file is complete and globally 441 * visible before dropping the final reference. If no membar, 442 * the current CPU could still access memory associated with 443 * the file after it has been freed or recycled by another 444 * CPU. 445 */ 446 #ifndef __HAVE_ATOMIC_AS_MEMBAR 447 membar_exit(); 448 #endif 449 450 /* 451 * Be optimistic and start out with the assumption that no other 452 * threads are trying to close the descriptor. If the CAS fails, 453 * we lost a race and/or it's being closed. 454 */ 455 for (u = ff->ff_refcnt & FR_MASK;; u = v) { 456 v = atomic_cas_uint(&ff->ff_refcnt, u, u - 1); 457 if (__predict_true(u == v)) { 458 return; 459 } 460 if (__predict_false((v & FR_CLOSING) != 0)) { 461 break; 462 } 463 } 464 465 /* Another thread is waiting to close the file: join it. */ 466 (void)fd_close(fd); 467 } 468 469 /* 470 * Convenience wrapper around fd_getfile() that returns reference 471 * to a vnode. 472 */ 473 int 474 fd_getvnode(unsigned fd, file_t **fpp) 475 { 476 vnode_t *vp; 477 file_t *fp; 478 479 fp = fd_getfile(fd); 480 if (__predict_false(fp == NULL)) { 481 return EBADF; 482 } 483 if (__predict_false(fp->f_type != DTYPE_VNODE)) { 484 fd_putfile(fd); 485 return EINVAL; 486 } 487 vp = fp->f_data; 488 if (__predict_false(vp->v_type == VBAD)) { 489 /* XXX Is this case really necessary? */ 490 fd_putfile(fd); 491 return EBADF; 492 } 493 *fpp = fp; 494 return 0; 495 } 496 497 /* 498 * Convenience wrapper around fd_getfile() that returns reference 499 * to a socket. 500 */ 501 int 502 fd_getsock(unsigned fd, struct socket **sop) 503 { 504 file_t *fp; 505 506 fp = fd_getfile(fd); 507 if (__predict_false(fp == NULL)) { 508 return EBADF; 509 } 510 if (__predict_false(fp->f_type != DTYPE_SOCKET)) { 511 fd_putfile(fd); 512 return ENOTSOCK; 513 } 514 *sop = fp->f_data; 515 return 0; 516 } 517 518 /* 519 * Look up the file structure corresponding to a file descriptor 520 * and return it with a reference held on the file, not the 521 * descriptor. 522 * 523 * This is heavyweight and only used when accessing descriptors 524 * from a foreign process. The caller must ensure that `p' does 525 * not exit or fork across this call. 526 * 527 * To release the file (not descriptor) reference, use closef(). 528 */ 529 file_t * 530 fd_getfile2(proc_t *p, unsigned fd) 531 { 532 filedesc_t *fdp; 533 fdfile_t *ff; 534 file_t *fp; 535 fdtab_t *dt; 536 537 fdp = p->p_fd; 538 mutex_enter(&fdp->fd_lock); 539 dt = fdp->fd_dt; 540 if (fd >= dt->dt_nfiles) { 541 mutex_exit(&fdp->fd_lock); 542 return NULL; 543 } 544 if ((ff = dt->dt_ff[fd]) == NULL) { 545 mutex_exit(&fdp->fd_lock); 546 return NULL; 547 } 548 if ((fp = ff->ff_file) == NULL) { 549 mutex_exit(&fdp->fd_lock); 550 return NULL; 551 } 552 mutex_enter(&fp->f_lock); 553 fp->f_count++; 554 mutex_exit(&fp->f_lock); 555 mutex_exit(&fdp->fd_lock); 556 557 return fp; 558 } 559 560 /* 561 * Internal form of close. Must be called with a reference to the 562 * descriptor, and will drop the reference. When all descriptor 563 * references are dropped, releases the descriptor slot and a single 564 * reference to the file structure. 565 */ 566 int 567 fd_close(unsigned fd) 568 { 569 struct flock lf; 570 filedesc_t *fdp; 571 fdfile_t *ff; 572 file_t *fp; 573 proc_t *p; 574 lwp_t *l; 575 u_int refcnt; 576 577 l = curlwp; 578 p = l->l_proc; 579 fdp = l->l_fd; 580 ff = fdp->fd_dt->dt_ff[fd]; 581 582 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 583 584 mutex_enter(&fdp->fd_lock); 585 KASSERT((ff->ff_refcnt & FR_MASK) > 0); 586 if (__predict_false(ff->ff_file == NULL)) { 587 /* 588 * Another user of the file is already closing, and is 589 * waiting for other users of the file to drain. Release 590 * our reference, and wake up the closer. 591 */ 592 atomic_dec_uint(&ff->ff_refcnt); 593 cv_broadcast(&ff->ff_closing); 594 mutex_exit(&fdp->fd_lock); 595 596 /* 597 * An application error, so pretend that the descriptor 598 * was already closed. We can't safely wait for it to 599 * be closed without potentially deadlocking. 600 */ 601 return (EBADF); 602 } 603 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 604 605 /* 606 * There may be multiple users of this file within the process. 607 * Notify existing and new users that the file is closing. This 608 * will prevent them from adding additional uses to this file 609 * while we are closing it. 610 */ 611 fp = ff->ff_file; 612 ff->ff_file = NULL; 613 ff->ff_exclose = false; 614 615 /* 616 * We expect the caller to hold a descriptor reference - drop it. 617 * The reference count may increase beyond zero at this point due 618 * to an erroneous descriptor reference by an application, but 619 * fd_getfile() will notice that the file is being closed and drop 620 * the reference again. 621 */ 622 if (fdp->fd_refcnt == 1) { 623 /* Single threaded. */ 624 refcnt = --(ff->ff_refcnt); 625 } else { 626 /* Multi threaded. */ 627 #ifndef __HAVE_ATOMIC_AS_MEMBAR 628 membar_producer(); 629 #endif 630 refcnt = atomic_dec_uint_nv(&ff->ff_refcnt); 631 } 632 if (__predict_false(refcnt != 0)) { 633 /* 634 * Wait for other references to drain. This is typically 635 * an application error - the descriptor is being closed 636 * while still in use. 637 * (Or just a threaded application trying to unblock its 638 * thread that sleeps in (say) accept()). 639 */ 640 atomic_or_uint(&ff->ff_refcnt, FR_CLOSING); 641 642 /* 643 * Remove any knotes attached to the file. A knote 644 * attached to the descriptor can hold references on it. 645 */ 646 mutex_exit(&fdp->fd_lock); 647 if (!SLIST_EMPTY(&ff->ff_knlist)) { 648 knote_fdclose(fd); 649 } 650 651 /* 652 * Since the file system code doesn't know which fd 653 * each request came from (think dup()), we have to 654 * ask it to return ERESTART for any long-term blocks. 655 * The re-entry through read/write/etc will detect the 656 * closed fd and return EBAFD. 657 * Blocked partial writes may return a short length. 658 */ 659 (*fp->f_ops->fo_restart)(fp); 660 mutex_enter(&fdp->fd_lock); 661 662 /* 663 * We need to see the count drop to zero at least once, 664 * in order to ensure that all pre-existing references 665 * have been drained. New references past this point are 666 * of no interest. 667 * XXX (dsl) this may need to call fo_restart() after a 668 * timeout to guarantee that all the system calls exit. 669 */ 670 while ((ff->ff_refcnt & FR_MASK) != 0) { 671 cv_wait(&ff->ff_closing, &fdp->fd_lock); 672 } 673 atomic_and_uint(&ff->ff_refcnt, ~FR_CLOSING); 674 } else { 675 /* If no references, there must be no knotes. */ 676 KASSERT(SLIST_EMPTY(&ff->ff_knlist)); 677 } 678 679 /* 680 * POSIX record locking dictates that any close releases ALL 681 * locks owned by this process. This is handled by setting 682 * a flag in the unlock to free ONLY locks obeying POSIX 683 * semantics, and not to free BSD-style file locks. 684 * If the descriptor was in a message, POSIX-style locks 685 * aren't passed with the descriptor. 686 */ 687 if (__predict_false((p->p_flag & PK_ADVLOCK) != 0 && 688 fp->f_type == DTYPE_VNODE)) { 689 lf.l_whence = SEEK_SET; 690 lf.l_start = 0; 691 lf.l_len = 0; 692 lf.l_type = F_UNLCK; 693 mutex_exit(&fdp->fd_lock); 694 (void)VOP_ADVLOCK(fp->f_data, p, F_UNLCK, &lf, F_POSIX); 695 mutex_enter(&fdp->fd_lock); 696 } 697 698 /* Free descriptor slot. */ 699 fd_unused(fdp, fd); 700 mutex_exit(&fdp->fd_lock); 701 702 /* Now drop reference to the file itself. */ 703 return closef(fp); 704 } 705 706 /* 707 * Duplicate a file descriptor. 708 */ 709 int 710 fd_dup(file_t *fp, int minfd, int *newp, bool exclose) 711 { 712 proc_t *p; 713 int error; 714 715 p = curproc; 716 717 while ((error = fd_alloc(p, minfd, newp)) != 0) { 718 if (error != ENOSPC) { 719 return error; 720 } 721 fd_tryexpand(p); 722 } 723 724 curlwp->l_fd->fd_dt->dt_ff[*newp]->ff_exclose = exclose; 725 fd_affix(p, fp, *newp); 726 return 0; 727 } 728 729 /* 730 * dup2 operation. 731 */ 732 int 733 fd_dup2(file_t *fp, unsigned new) 734 { 735 filedesc_t *fdp; 736 fdfile_t *ff; 737 fdtab_t *dt; 738 739 fdp = curlwp->l_fd; 740 741 /* 742 * Ensure there are enough slots in the descriptor table, 743 * and allocate an fdfile_t up front in case we need it. 744 */ 745 while (new >= fdp->fd_dt->dt_nfiles) { 746 fd_tryexpand(curproc); 747 } 748 ff = pool_cache_get(fdfile_cache, PR_WAITOK); 749 750 /* 751 * If there is already a file open, close it. If the file is 752 * half open, wait for it to be constructed before closing it. 753 * XXX Potential for deadlock here? 754 */ 755 mutex_enter(&fdp->fd_lock); 756 while (fd_isused(fdp, new)) { 757 mutex_exit(&fdp->fd_lock); 758 if (fd_getfile(new) != NULL) { 759 (void)fd_close(new); 760 } else { 761 /* 762 * Crummy, but unlikely to happen. 763 * Can occur if we interrupt another 764 * thread while it is opening a file. 765 */ 766 kpause("dup2", false, 1, NULL); 767 } 768 mutex_enter(&fdp->fd_lock); 769 } 770 dt = fdp->fd_dt; 771 if (dt->dt_ff[new] == NULL) { 772 KASSERT(new >= NDFDFILE); 773 dt->dt_ff[new] = ff; 774 ff = NULL; 775 } 776 fd_used(fdp, new); 777 mutex_exit(&fdp->fd_lock); 778 779 /* Slot is now allocated. Insert copy of the file. */ 780 fd_affix(curproc, fp, new); 781 if (ff != NULL) { 782 pool_cache_put(fdfile_cache, ff); 783 } 784 return 0; 785 } 786 787 /* 788 * Drop reference to a file structure. 789 */ 790 int 791 closef(file_t *fp) 792 { 793 struct flock lf; 794 int error; 795 796 /* 797 * Drop reference. If referenced elsewhere it's still open 798 * and we have nothing more to do. 799 */ 800 mutex_enter(&fp->f_lock); 801 KASSERT(fp->f_count > 0); 802 if (--fp->f_count > 0) { 803 mutex_exit(&fp->f_lock); 804 return 0; 805 } 806 KASSERT(fp->f_count == 0); 807 mutex_exit(&fp->f_lock); 808 809 /* We held the last reference - release locks, close and free. */ 810 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 811 lf.l_whence = SEEK_SET; 812 lf.l_start = 0; 813 lf.l_len = 0; 814 lf.l_type = F_UNLCK; 815 (void)VOP_ADVLOCK(fp->f_data, fp, F_UNLCK, &lf, F_FLOCK); 816 } 817 if (fp->f_ops != NULL) { 818 error = (*fp->f_ops->fo_close)(fp); 819 } else { 820 error = 0; 821 } 822 KASSERT(fp->f_count == 0); 823 KASSERT(fp->f_cred != NULL); 824 pool_cache_put(file_cache, fp); 825 826 return error; 827 } 828 829 /* 830 * Allocate a file descriptor for the process. 831 */ 832 int 833 fd_alloc(proc_t *p, int want, int *result) 834 { 835 filedesc_t *fdp; 836 int i, lim, last, error; 837 u_int off, new; 838 fdtab_t *dt; 839 840 KASSERT(p == curproc || p == &proc0); 841 842 fdp = p->p_fd; 843 844 /* 845 * Search for a free descriptor starting at the higher 846 * of want or fd_freefile. 847 */ 848 mutex_enter(&fdp->fd_lock); 849 fd_checkmaps(fdp); 850 dt = fdp->fd_dt; 851 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 852 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 853 last = min(dt->dt_nfiles, lim); 854 for (;;) { 855 if ((i = want) < fdp->fd_freefile) 856 i = fdp->fd_freefile; 857 off = i >> NDENTRYSHIFT; 858 new = fd_next_zero(fdp, fdp->fd_himap, off, 859 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 860 if (new == -1) 861 break; 862 i = fd_next_zero(fdp, &fdp->fd_lomap[new], 863 new > off ? 0 : i & NDENTRYMASK, NDENTRIES); 864 if (i == -1) { 865 /* 866 * Free file descriptor in this block was 867 * below want, try again with higher want. 868 */ 869 want = (new + 1) << NDENTRYSHIFT; 870 continue; 871 } 872 i += (new << NDENTRYSHIFT); 873 if (i >= last) { 874 break; 875 } 876 if (dt->dt_ff[i] == NULL) { 877 KASSERT(i >= NDFDFILE); 878 dt->dt_ff[i] = pool_cache_get(fdfile_cache, PR_WAITOK); 879 } 880 KASSERT(dt->dt_ff[i]->ff_file == NULL); 881 fd_used(fdp, i); 882 if (want <= fdp->fd_freefile) { 883 fdp->fd_freefile = i; 884 } 885 *result = i; 886 KASSERT(i >= NDFDFILE || 887 dt->dt_ff[i] == (fdfile_t *)fdp->fd_dfdfile[i]); 888 fd_checkmaps(fdp); 889 mutex_exit(&fdp->fd_lock); 890 return 0; 891 } 892 893 /* No space in current array. Let the caller expand and retry. */ 894 error = (dt->dt_nfiles >= lim) ? EMFILE : ENOSPC; 895 mutex_exit(&fdp->fd_lock); 896 return error; 897 } 898 899 /* 900 * Allocate memory for a descriptor table. 901 */ 902 static fdtab_t * 903 fd_dtab_alloc(int n) 904 { 905 fdtab_t *dt; 906 size_t sz; 907 908 KASSERT(n > NDFILE); 909 910 sz = sizeof(*dt) + (n - NDFILE) * sizeof(dt->dt_ff[0]); 911 dt = kmem_alloc(sz, KM_SLEEP); 912 #ifdef DIAGNOSTIC 913 memset(dt, 0xff, sz); 914 #endif 915 dt->dt_nfiles = n; 916 dt->dt_link = NULL; 917 return dt; 918 } 919 920 /* 921 * Free a descriptor table, and all tables linked for deferred free. 922 */ 923 static void 924 fd_dtab_free(fdtab_t *dt) 925 { 926 fdtab_t *next; 927 size_t sz; 928 929 do { 930 next = dt->dt_link; 931 KASSERT(dt->dt_nfiles > NDFILE); 932 sz = sizeof(*dt) + 933 (dt->dt_nfiles - NDFILE) * sizeof(dt->dt_ff[0]); 934 #ifdef DIAGNOSTIC 935 memset(dt, 0xff, sz); 936 #endif 937 kmem_free(dt, sz); 938 dt = next; 939 } while (dt != NULL); 940 } 941 942 /* 943 * Allocate descriptor bitmap. 944 */ 945 static void 946 fd_map_alloc(int n, uint32_t **lo, uint32_t **hi) 947 { 948 uint8_t *ptr; 949 size_t szlo, szhi; 950 951 KASSERT(n > NDENTRIES); 952 953 szlo = NDLOSLOTS(n) * sizeof(uint32_t); 954 szhi = NDHISLOTS(n) * sizeof(uint32_t); 955 ptr = kmem_alloc(szlo + szhi, KM_SLEEP); 956 *lo = (uint32_t *)ptr; 957 *hi = (uint32_t *)(ptr + szlo); 958 } 959 960 /* 961 * Free descriptor bitmap. 962 */ 963 static void 964 fd_map_free(int n, uint32_t *lo, uint32_t *hi) 965 { 966 size_t szlo, szhi; 967 968 KASSERT(n > NDENTRIES); 969 970 szlo = NDLOSLOTS(n) * sizeof(uint32_t); 971 szhi = NDHISLOTS(n) * sizeof(uint32_t); 972 KASSERT(hi == (uint32_t *)((uint8_t *)lo + szlo)); 973 kmem_free(lo, szlo + szhi); 974 } 975 976 /* 977 * Expand a process' descriptor table. 978 */ 979 void 980 fd_tryexpand(proc_t *p) 981 { 982 filedesc_t *fdp; 983 int i, numfiles, oldnfiles; 984 fdtab_t *newdt, *dt; 985 uint32_t *newhimap, *newlomap; 986 987 KASSERT(p == curproc || p == &proc0); 988 989 fdp = p->p_fd; 990 newhimap = NULL; 991 newlomap = NULL; 992 oldnfiles = fdp->fd_dt->dt_nfiles; 993 994 if (oldnfiles < NDEXTENT) 995 numfiles = NDEXTENT; 996 else 997 numfiles = 2 * oldnfiles; 998 999 newdt = fd_dtab_alloc(numfiles); 1000 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1001 fd_map_alloc(numfiles, &newlomap, &newhimap); 1002 } 1003 1004 mutex_enter(&fdp->fd_lock); 1005 dt = fdp->fd_dt; 1006 KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1007 if (dt->dt_nfiles != oldnfiles) { 1008 /* fdp changed; caller must retry */ 1009 mutex_exit(&fdp->fd_lock); 1010 fd_dtab_free(newdt); 1011 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1012 fd_map_free(numfiles, newlomap, newhimap); 1013 } 1014 return; 1015 } 1016 1017 /* Copy the existing descriptor table and zero the new portion. */ 1018 i = sizeof(fdfile_t *) * oldnfiles; 1019 memcpy(newdt->dt_ff, dt->dt_ff, i); 1020 memset((uint8_t *)newdt->dt_ff + i, 0, 1021 numfiles * sizeof(fdfile_t *) - i); 1022 1023 /* 1024 * Link old descriptor array into list to be discarded. We defer 1025 * freeing until the last reference to the descriptor table goes 1026 * away (usually process exit). This allows us to do lockless 1027 * lookups in fd_getfile(). 1028 */ 1029 if (oldnfiles > NDFILE) { 1030 if (fdp->fd_refcnt > 1) { 1031 newdt->dt_link = dt; 1032 } else { 1033 fd_dtab_free(dt); 1034 } 1035 } 1036 1037 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 1038 i = NDHISLOTS(oldnfiles) * sizeof(uint32_t); 1039 memcpy(newhimap, fdp->fd_himap, i); 1040 memset((uint8_t *)newhimap + i, 0, 1041 NDHISLOTS(numfiles) * sizeof(uint32_t) - i); 1042 1043 i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t); 1044 memcpy(newlomap, fdp->fd_lomap, i); 1045 memset((uint8_t *)newlomap + i, 0, 1046 NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); 1047 1048 if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { 1049 fd_map_free(oldnfiles, fdp->fd_lomap, fdp->fd_himap); 1050 } 1051 fdp->fd_himap = newhimap; 1052 fdp->fd_lomap = newlomap; 1053 } 1054 1055 /* 1056 * All other modifications must become globally visible before 1057 * the change to fd_dt. See fd_getfile(). 1058 */ 1059 membar_producer(); 1060 fdp->fd_dt = newdt; 1061 KASSERT(newdt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1062 fd_checkmaps(fdp); 1063 mutex_exit(&fdp->fd_lock); 1064 } 1065 1066 /* 1067 * Create a new open file structure and allocate a file descriptor 1068 * for the current process. 1069 */ 1070 int 1071 fd_allocfile(file_t **resultfp, int *resultfd) 1072 { 1073 kauth_cred_t cred; 1074 file_t *fp; 1075 proc_t *p; 1076 int error; 1077 1078 p = curproc; 1079 1080 while ((error = fd_alloc(p, 0, resultfd)) != 0) { 1081 if (error != ENOSPC) { 1082 return error; 1083 } 1084 fd_tryexpand(p); 1085 } 1086 1087 fp = pool_cache_get(file_cache, PR_WAITOK); 1088 if (fp == NULL) { 1089 return ENFILE; 1090 } 1091 KASSERT(fp->f_count == 0); 1092 KASSERT(fp->f_msgcount == 0); 1093 KASSERT(fp->f_unpcount == 0); 1094 1095 /* Replace cached credentials if not what we need. */ 1096 cred = curlwp->l_cred; 1097 if (__predict_false(cred != fp->f_cred)) { 1098 kauth_cred_free(fp->f_cred); 1099 kauth_cred_hold(cred); 1100 fp->f_cred = cred; 1101 } 1102 1103 /* 1104 * Don't allow recycled files to be scanned. 1105 * See uipc_usrreq.c. 1106 */ 1107 if (__predict_false((fp->f_flag & FSCAN) != 0)) { 1108 mutex_enter(&fp->f_lock); 1109 atomic_and_uint(&fp->f_flag, ~FSCAN); 1110 mutex_exit(&fp->f_lock); 1111 } 1112 1113 fp->f_advice = 0; 1114 fp->f_offset = 0; 1115 *resultfp = fp; 1116 1117 return 0; 1118 } 1119 1120 /* 1121 * Successful creation of a new descriptor: make visible to the process. 1122 */ 1123 void 1124 fd_affix(proc_t *p, file_t *fp, unsigned fd) 1125 { 1126 fdfile_t *ff; 1127 filedesc_t *fdp; 1128 1129 KASSERT(p == curproc || p == &proc0); 1130 1131 /* Add a reference to the file structure. */ 1132 mutex_enter(&fp->f_lock); 1133 fp->f_count++; 1134 mutex_exit(&fp->f_lock); 1135 1136 /* 1137 * Insert the new file into the descriptor slot. 1138 * 1139 * The memory barriers provided by lock activity in this routine 1140 * ensure that any updates to the file structure become globally 1141 * visible before the file becomes visible to other LWPs in the 1142 * current process. 1143 */ 1144 fdp = p->p_fd; 1145 ff = fdp->fd_dt->dt_ff[fd]; 1146 1147 KASSERT(ff != NULL); 1148 KASSERT(ff->ff_file == NULL); 1149 KASSERT(ff->ff_allocated); 1150 KASSERT(fd_isused(fdp, fd)); 1151 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1152 1153 /* No need to lock in order to make file initially visible. */ 1154 ff->ff_file = fp; 1155 } 1156 1157 /* 1158 * Abort creation of a new descriptor: free descriptor slot and file. 1159 */ 1160 void 1161 fd_abort(proc_t *p, file_t *fp, unsigned fd) 1162 { 1163 filedesc_t *fdp; 1164 fdfile_t *ff; 1165 1166 KASSERT(p == curproc || p == &proc0); 1167 1168 fdp = p->p_fd; 1169 ff = fdp->fd_dt->dt_ff[fd]; 1170 1171 KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1172 1173 mutex_enter(&fdp->fd_lock); 1174 KASSERT(fd_isused(fdp, fd)); 1175 fd_unused(fdp, fd); 1176 mutex_exit(&fdp->fd_lock); 1177 1178 if (fp != NULL) { 1179 KASSERT(fp->f_count == 0); 1180 KASSERT(fp->f_cred != NULL); 1181 pool_cache_put(file_cache, fp); 1182 } 1183 } 1184 1185 static int 1186 file_ctor(void *arg, void *obj, int flags) 1187 { 1188 file_t *fp = obj; 1189 1190 memset(fp, 0, sizeof(*fp)); 1191 1192 mutex_enter(&filelist_lock); 1193 if (__predict_false(nfiles >= maxfiles)) { 1194 mutex_exit(&filelist_lock); 1195 tablefull("file", "increase kern.maxfiles or MAXFILES"); 1196 return ENFILE; 1197 } 1198 nfiles++; 1199 LIST_INSERT_HEAD(&filehead, fp, f_list); 1200 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1201 fp->f_cred = curlwp->l_cred; 1202 kauth_cred_hold(fp->f_cred); 1203 mutex_exit(&filelist_lock); 1204 1205 return 0; 1206 } 1207 1208 static void 1209 file_dtor(void *arg, void *obj) 1210 { 1211 file_t *fp = obj; 1212 1213 mutex_enter(&filelist_lock); 1214 nfiles--; 1215 LIST_REMOVE(fp, f_list); 1216 mutex_exit(&filelist_lock); 1217 1218 kauth_cred_free(fp->f_cred); 1219 mutex_destroy(&fp->f_lock); 1220 } 1221 1222 static int 1223 fdfile_ctor(void *arg, void *obj, int flags) 1224 { 1225 fdfile_t *ff = obj; 1226 1227 memset(ff, 0, sizeof(*ff)); 1228 cv_init(&ff->ff_closing, "fdclose"); 1229 1230 return 0; 1231 } 1232 1233 static void 1234 fdfile_dtor(void *arg, void *obj) 1235 { 1236 fdfile_t *ff = obj; 1237 1238 cv_destroy(&ff->ff_closing); 1239 } 1240 1241 file_t * 1242 fgetdummy(void) 1243 { 1244 file_t *fp; 1245 1246 fp = kmem_alloc(sizeof(*fp), KM_SLEEP); 1247 if (fp != NULL) { 1248 memset(fp, 0, sizeof(*fp)); 1249 mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); 1250 } 1251 return fp; 1252 } 1253 1254 void 1255 fputdummy(file_t *fp) 1256 { 1257 1258 mutex_destroy(&fp->f_lock); 1259 kmem_free(fp, sizeof(*fp)); 1260 } 1261 1262 /* 1263 * Create an initial filedesc structure. 1264 */ 1265 filedesc_t * 1266 fd_init(filedesc_t *fdp) 1267 { 1268 #ifdef DIAGNOSTIC 1269 unsigned fd; 1270 #endif 1271 1272 if (__predict_true(fdp == NULL)) { 1273 fdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1274 } else { 1275 KASSERT(fdp == &filedesc0); 1276 filedesc_ctor(NULL, fdp, PR_WAITOK); 1277 } 1278 1279 #ifdef DIAGNOSTIC 1280 KASSERT(fdp->fd_lastfile == -1); 1281 KASSERT(fdp->fd_lastkqfile == -1); 1282 KASSERT(fdp->fd_knhash == NULL); 1283 KASSERT(fdp->fd_freefile == 0); 1284 KASSERT(fdp->fd_exclose == false); 1285 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1286 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1287 for (fd = 0; fd < NDFDFILE; fd++) { 1288 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == 1289 (fdfile_t *)fdp->fd_dfdfile[fd]); 1290 } 1291 for (fd = NDFDFILE; fd < NDFILE; fd++) { 1292 KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == NULL); 1293 } 1294 KASSERT(fdp->fd_himap == fdp->fd_dhimap); 1295 KASSERT(fdp->fd_lomap == fdp->fd_dlomap); 1296 #endif /* DIAGNOSTIC */ 1297 1298 fdp->fd_refcnt = 1; 1299 fd_checkmaps(fdp); 1300 1301 return fdp; 1302 } 1303 1304 /* 1305 * Initialize a file descriptor table. 1306 */ 1307 static int 1308 filedesc_ctor(void *arg, void *obj, int flag) 1309 { 1310 filedesc_t *fdp = obj; 1311 fdfile_t **ffp; 1312 int i; 1313 1314 memset(fdp, 0, sizeof(*fdp)); 1315 mutex_init(&fdp->fd_lock, MUTEX_DEFAULT, IPL_NONE); 1316 fdp->fd_lastfile = -1; 1317 fdp->fd_lastkqfile = -1; 1318 fdp->fd_dt = &fdp->fd_dtbuiltin; 1319 fdp->fd_dtbuiltin.dt_nfiles = NDFILE; 1320 fdp->fd_himap = fdp->fd_dhimap; 1321 fdp->fd_lomap = fdp->fd_dlomap; 1322 1323 CTASSERT(sizeof(fdp->fd_dfdfile[0]) >= sizeof(fdfile_t)); 1324 for (i = 0, ffp = fdp->fd_dt->dt_ff; i < NDFDFILE; i++, ffp++) { 1325 *ffp = (fdfile_t *)fdp->fd_dfdfile[i]; 1326 (void)fdfile_ctor(NULL, fdp->fd_dfdfile[i], PR_WAITOK); 1327 } 1328 1329 return 0; 1330 } 1331 1332 static void 1333 filedesc_dtor(void *arg, void *obj) 1334 { 1335 filedesc_t *fdp = obj; 1336 int i; 1337 1338 for (i = 0; i < NDFDFILE; i++) { 1339 fdfile_dtor(NULL, fdp->fd_dfdfile[i]); 1340 } 1341 1342 mutex_destroy(&fdp->fd_lock); 1343 } 1344 1345 /* 1346 * Make p share curproc's filedesc structure. 1347 */ 1348 void 1349 fd_share(struct proc *p) 1350 { 1351 filedesc_t *fdp; 1352 1353 fdp = curlwp->l_fd; 1354 p->p_fd = fdp; 1355 atomic_inc_uint(&fdp->fd_refcnt); 1356 } 1357 1358 /* 1359 * Acquire a hold on a filedesc structure. 1360 */ 1361 void 1362 fd_hold(lwp_t *l) 1363 { 1364 filedesc_t *fdp = l->l_fd; 1365 1366 atomic_inc_uint(&fdp->fd_refcnt); 1367 } 1368 1369 /* 1370 * Copy a filedesc structure. 1371 */ 1372 filedesc_t * 1373 fd_copy(void) 1374 { 1375 filedesc_t *newfdp, *fdp; 1376 fdfile_t *ff, **ffp, **nffp, *ff2; 1377 int i, j, numfiles, lastfile, newlast; 1378 file_t *fp; 1379 fdtab_t *newdt; 1380 1381 fdp = curproc->p_fd; 1382 newfdp = pool_cache_get(filedesc_cache, PR_WAITOK); 1383 newfdp->fd_refcnt = 1; 1384 1385 #ifdef DIAGNOSTIC 1386 KASSERT(newfdp->fd_lastfile == -1); 1387 KASSERT(newfdp->fd_lastkqfile == -1); 1388 KASSERT(newfdp->fd_knhash == NULL); 1389 KASSERT(newfdp->fd_freefile == 0); 1390 KASSERT(newfdp->fd_exclose == false); 1391 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1392 KASSERT(newfdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1393 for (i = 0; i < NDFDFILE; i++) { 1394 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == 1395 (fdfile_t *)&newfdp->fd_dfdfile[i]); 1396 } 1397 for (i = NDFDFILE; i < NDFILE; i++) { 1398 KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == NULL); 1399 } 1400 #endif /* DIAGNOSTIC */ 1401 1402 mutex_enter(&fdp->fd_lock); 1403 fd_checkmaps(fdp); 1404 numfiles = fdp->fd_dt->dt_nfiles; 1405 lastfile = fdp->fd_lastfile; 1406 1407 /* 1408 * If the number of open files fits in the internal arrays 1409 * of the open file structure, use them, otherwise allocate 1410 * additional memory for the number of descriptors currently 1411 * in use. 1412 */ 1413 if (lastfile < NDFILE) { 1414 i = NDFILE; 1415 newdt = newfdp->fd_dt; 1416 KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); 1417 } else { 1418 /* 1419 * Compute the smallest multiple of NDEXTENT needed 1420 * for the file descriptors currently in use, 1421 * allowing the table to shrink. 1422 */ 1423 i = numfiles; 1424 while (i >= 2 * NDEXTENT && i > lastfile * 2) { 1425 i /= 2; 1426 } 1427 KASSERT(i > NDFILE); 1428 newdt = fd_dtab_alloc(i); 1429 newfdp->fd_dt = newdt; 1430 memcpy(newdt->dt_ff, newfdp->fd_dtbuiltin.dt_ff, 1431 NDFDFILE * sizeof(fdfile_t **)); 1432 memset(newdt->dt_ff + NDFDFILE, 0, 1433 (i - NDFDFILE) * sizeof(fdfile_t **)); 1434 } 1435 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { 1436 newfdp->fd_himap = newfdp->fd_dhimap; 1437 newfdp->fd_lomap = newfdp->fd_dlomap; 1438 } else { 1439 fd_map_alloc(i, &newfdp->fd_lomap, &newfdp->fd_himap); 1440 KASSERT(i >= NDENTRIES * NDENTRIES); 1441 memset(newfdp->fd_himap, 0, NDHISLOTS(i)*sizeof(uint32_t)); 1442 memset(newfdp->fd_lomap, 0, NDLOSLOTS(i)*sizeof(uint32_t)); 1443 } 1444 newfdp->fd_freefile = fdp->fd_freefile; 1445 newfdp->fd_exclose = fdp->fd_exclose; 1446 1447 ffp = fdp->fd_dt->dt_ff; 1448 nffp = newdt->dt_ff; 1449 newlast = -1; 1450 for (i = 0; i <= (int)lastfile; i++, ffp++, nffp++) { 1451 KASSERT(i >= NDFDFILE || 1452 *nffp == (fdfile_t *)newfdp->fd_dfdfile[i]); 1453 ff = *ffp; 1454 if (ff == NULL || (fp = ff->ff_file) == NULL) { 1455 /* Descriptor unused, or descriptor half open. */ 1456 KASSERT(!fd_isused(newfdp, i)); 1457 continue; 1458 } 1459 if (__predict_false(fp->f_type == DTYPE_KQUEUE)) { 1460 /* kqueue descriptors cannot be copied. */ 1461 if (i < newfdp->fd_freefile) 1462 newfdp->fd_freefile = i; 1463 continue; 1464 } 1465 /* It's active: add a reference to the file. */ 1466 mutex_enter(&fp->f_lock); 1467 fp->f_count++; 1468 mutex_exit(&fp->f_lock); 1469 1470 /* Allocate an fdfile_t to represent it. */ 1471 if (i >= NDFDFILE) { 1472 ff2 = pool_cache_get(fdfile_cache, PR_WAITOK); 1473 *nffp = ff2; 1474 } else { 1475 ff2 = newdt->dt_ff[i]; 1476 } 1477 ff2->ff_file = fp; 1478 ff2->ff_exclose = ff->ff_exclose; 1479 ff2->ff_allocated = true; 1480 1481 /* Fix up bitmaps. */ 1482 j = i >> NDENTRYSHIFT; 1483 KASSERT((newfdp->fd_lomap[j] & (1 << (i & NDENTRYMASK))) == 0); 1484 newfdp->fd_lomap[j] |= 1 << (i & NDENTRYMASK); 1485 if (__predict_false(newfdp->fd_lomap[j] == ~0)) { 1486 KASSERT((newfdp->fd_himap[j >> NDENTRYSHIFT] & 1487 (1 << (j & NDENTRYMASK))) == 0); 1488 newfdp->fd_himap[j >> NDENTRYSHIFT] |= 1489 1 << (j & NDENTRYMASK); 1490 } 1491 newlast = i; 1492 } 1493 KASSERT(newdt->dt_ff[0] == (fdfile_t *)newfdp->fd_dfdfile[0]); 1494 newfdp->fd_lastfile = newlast; 1495 fd_checkmaps(newfdp); 1496 mutex_exit(&fdp->fd_lock); 1497 1498 return (newfdp); 1499 } 1500 1501 /* 1502 * Release a filedesc structure. 1503 */ 1504 void 1505 fd_free(void) 1506 { 1507 fdfile_t *ff; 1508 file_t *fp; 1509 int fd, nf; 1510 fdtab_t *dt; 1511 lwp_t * const l = curlwp; 1512 filedesc_t * const fdp = l->l_fd; 1513 const bool noadvlock = (l->l_proc->p_flag & PK_ADVLOCK) == 0; 1514 1515 KASSERT(fdp->fd_dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); 1516 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1517 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1518 1519 #ifndef __HAVE_ATOMIC_AS_MEMBAR 1520 membar_exit(); 1521 #endif 1522 if (atomic_dec_uint_nv(&fdp->fd_refcnt) > 0) 1523 return; 1524 1525 /* 1526 * Close any files that the process holds open. 1527 */ 1528 dt = fdp->fd_dt; 1529 fd_checkmaps(fdp); 1530 #ifdef DEBUG 1531 fdp->fd_refcnt = -1; /* see fd_checkmaps */ 1532 #endif 1533 for (fd = 0, nf = dt->dt_nfiles; fd < nf; fd++) { 1534 ff = dt->dt_ff[fd]; 1535 KASSERT(fd >= NDFDFILE || 1536 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1537 if (ff == NULL) 1538 continue; 1539 if ((fp = ff->ff_file) != NULL) { 1540 /* 1541 * Must use fd_close() here if there is 1542 * a reference from kqueue or we might have posix 1543 * advisory locks. 1544 */ 1545 if (__predict_true(ff->ff_refcnt == 0) && 1546 (noadvlock || fp->f_type != DTYPE_VNODE)) { 1547 ff->ff_file = NULL; 1548 ff->ff_exclose = false; 1549 ff->ff_allocated = false; 1550 closef(fp); 1551 } else { 1552 ff->ff_refcnt++; 1553 fd_close(fd); 1554 } 1555 } 1556 KASSERT(ff->ff_refcnt == 0); 1557 KASSERT(ff->ff_file == NULL); 1558 KASSERT(!ff->ff_exclose); 1559 KASSERT(!ff->ff_allocated); 1560 if (fd >= NDFDFILE) { 1561 pool_cache_put(fdfile_cache, ff); 1562 dt->dt_ff[fd] = NULL; 1563 } 1564 } 1565 1566 /* 1567 * Clean out the descriptor table for the next user and return 1568 * to the cache. 1569 */ 1570 if (__predict_false(dt != &fdp->fd_dtbuiltin)) { 1571 fd_dtab_free(fdp->fd_dt); 1572 /* Otherwise, done above. */ 1573 memset(&fdp->fd_dtbuiltin.dt_ff[NDFDFILE], 0, 1574 (NDFILE - NDFDFILE) * sizeof(fdp->fd_dtbuiltin.dt_ff[0])); 1575 fdp->fd_dt = &fdp->fd_dtbuiltin; 1576 } 1577 if (__predict_false(NDHISLOTS(nf) > NDHISLOTS(NDFILE))) { 1578 KASSERT(fdp->fd_himap != fdp->fd_dhimap); 1579 KASSERT(fdp->fd_lomap != fdp->fd_dlomap); 1580 fd_map_free(nf, fdp->fd_lomap, fdp->fd_himap); 1581 } 1582 if (__predict_false(fdp->fd_knhash != NULL)) { 1583 hashdone(fdp->fd_knhash, HASH_LIST, fdp->fd_knhashmask); 1584 fdp->fd_knhash = NULL; 1585 fdp->fd_knhashmask = 0; 1586 } else { 1587 KASSERT(fdp->fd_knhashmask == 0); 1588 } 1589 fdp->fd_dt = &fdp->fd_dtbuiltin; 1590 fdp->fd_lastkqfile = -1; 1591 fdp->fd_lastfile = -1; 1592 fdp->fd_freefile = 0; 1593 fdp->fd_exclose = false; 1594 memset(&fdp->fd_startzero, 0, sizeof(*fdp) - 1595 offsetof(filedesc_t, fd_startzero)); 1596 fdp->fd_himap = fdp->fd_dhimap; 1597 fdp->fd_lomap = fdp->fd_dlomap; 1598 KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); 1599 KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); 1600 KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); 1601 #ifdef DEBUG 1602 fdp->fd_refcnt = 0; /* see fd_checkmaps */ 1603 #endif 1604 fd_checkmaps(fdp); 1605 pool_cache_put(filedesc_cache, fdp); 1606 } 1607 1608 /* 1609 * File Descriptor pseudo-device driver (/dev/fd/). 1610 * 1611 * Opening minor device N dup()s the file (if any) connected to file 1612 * descriptor N belonging to the calling process. Note that this driver 1613 * consists of only the ``open()'' routine, because all subsequent 1614 * references to this file will be direct to the other driver. 1615 */ 1616 static int 1617 filedescopen(dev_t dev, int mode, int type, lwp_t *l) 1618 { 1619 1620 /* 1621 * XXX Kludge: set dupfd to contain the value of the 1622 * the file descriptor being sought for duplication. The error 1623 * return ensures that the vnode for this device will be released 1624 * by vn_open. Open will detect this special error and take the 1625 * actions in fd_dupopen below. Other callers of vn_open or VOP_OPEN 1626 * will simply report the error. 1627 */ 1628 l->l_dupfd = minor(dev); /* XXX */ 1629 return EDUPFD; 1630 } 1631 1632 /* 1633 * Duplicate the specified descriptor to a free descriptor. 1634 */ 1635 int 1636 fd_dupopen(int old, int *new, int mode, int error) 1637 { 1638 filedesc_t *fdp; 1639 fdfile_t *ff; 1640 file_t *fp; 1641 fdtab_t *dt; 1642 1643 if ((fp = fd_getfile(old)) == NULL) { 1644 return EBADF; 1645 } 1646 fdp = curlwp->l_fd; 1647 dt = fdp->fd_dt; 1648 ff = dt->dt_ff[old]; 1649 1650 /* 1651 * There are two cases of interest here. 1652 * 1653 * For EDUPFD simply dup (old) to file descriptor 1654 * (new) and return. 1655 * 1656 * For EMOVEFD steal away the file structure from (old) and 1657 * store it in (new). (old) is effectively closed by 1658 * this operation. 1659 * 1660 * Any other error code is just returned. 1661 */ 1662 switch (error) { 1663 case EDUPFD: 1664 /* 1665 * Check that the mode the file is being opened for is a 1666 * subset of the mode of the existing descriptor. 1667 */ 1668 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 1669 error = EACCES; 1670 break; 1671 } 1672 1673 /* Copy it. */ 1674 error = fd_dup(fp, 0, new, ff->ff_exclose); 1675 break; 1676 1677 case EMOVEFD: 1678 /* Copy it. */ 1679 error = fd_dup(fp, 0, new, ff->ff_exclose); 1680 if (error != 0) { 1681 break; 1682 } 1683 1684 /* Steal away the file pointer from 'old'. */ 1685 (void)fd_close(old); 1686 return 0; 1687 } 1688 1689 fd_putfile(old); 1690 return error; 1691 } 1692 1693 /* 1694 * Close open files on exec. 1695 */ 1696 void 1697 fd_closeexec(void) 1698 { 1699 proc_t *p; 1700 filedesc_t *fdp; 1701 fdfile_t *ff; 1702 lwp_t *l; 1703 fdtab_t *dt; 1704 int fd; 1705 1706 l = curlwp; 1707 p = l->l_proc; 1708 fdp = p->p_fd; 1709 1710 if (fdp->fd_refcnt > 1) { 1711 fdp = fd_copy(); 1712 fd_free(); 1713 p->p_fd = fdp; 1714 l->l_fd = fdp; 1715 } 1716 if (!fdp->fd_exclose) { 1717 return; 1718 } 1719 fdp->fd_exclose = false; 1720 dt = fdp->fd_dt; 1721 1722 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 1723 if ((ff = dt->dt_ff[fd]) == NULL) { 1724 KASSERT(fd >= NDFDFILE); 1725 continue; 1726 } 1727 KASSERT(fd >= NDFDFILE || 1728 ff == (fdfile_t *)fdp->fd_dfdfile[fd]); 1729 if (ff->ff_file == NULL) 1730 continue; 1731 if (ff->ff_exclose) { 1732 /* 1733 * We need a reference to close the file. 1734 * No other threads can see the fdfile_t at 1735 * this point, so don't bother locking. 1736 */ 1737 KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); 1738 ff->ff_refcnt++; 1739 fd_close(fd); 1740 } 1741 } 1742 } 1743 1744 /* 1745 * Sets descriptor owner. If the owner is a process, 'pgid' 1746 * is set to positive value, process ID. If the owner is process group, 1747 * 'pgid' is set to -pg_id. 1748 */ 1749 int 1750 fsetown(pid_t *pgid, u_long cmd, const void *data) 1751 { 1752 pid_t id = *(const pid_t *)data; 1753 int error; 1754 1755 switch (cmd) { 1756 case TIOCSPGRP: 1757 if (id < 0) 1758 return EINVAL; 1759 id = -id; 1760 break; 1761 default: 1762 break; 1763 } 1764 if (id > 0) { 1765 mutex_enter(proc_lock); 1766 error = proc_find(id) ? 0 : ESRCH; 1767 mutex_exit(proc_lock); 1768 } else if (id < 0) { 1769 error = pgid_in_session(curproc, -id); 1770 } else { 1771 error = 0; 1772 } 1773 if (!error) { 1774 *pgid = id; 1775 } 1776 return error; 1777 } 1778 1779 /* 1780 * Return descriptor owner information. If the value is positive, 1781 * it's process ID. If it's negative, it's process group ID and 1782 * needs the sign removed before use. 1783 */ 1784 int 1785 fgetown(pid_t pgid, u_long cmd, void *data) 1786 { 1787 1788 switch (cmd) { 1789 case TIOCGPGRP: 1790 *(int *)data = -pgid; 1791 break; 1792 default: 1793 *(int *)data = pgid; 1794 break; 1795 } 1796 return (0); 1797 } 1798 1799 /* 1800 * Send signal to descriptor owner, either process or process group. 1801 */ 1802 void 1803 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) 1804 { 1805 ksiginfo_t ksi; 1806 1807 KASSERT(!cpu_intr_p()); 1808 1809 if (pgid == 0) { 1810 return; 1811 } 1812 1813 KSI_INIT(&ksi); 1814 ksi.ksi_signo = signo; 1815 ksi.ksi_code = code; 1816 ksi.ksi_band = band; 1817 1818 mutex_enter(proc_lock); 1819 if (pgid > 0) { 1820 struct proc *p1; 1821 1822 p1 = proc_find(pgid); 1823 if (p1 != NULL) { 1824 kpsignal(p1, &ksi, fdescdata); 1825 } 1826 } else { 1827 struct pgrp *pgrp; 1828 1829 KASSERT(pgid < 0); 1830 pgrp = pgrp_find(-pgid); 1831 if (pgrp != NULL) { 1832 kpgsignal(pgrp, &ksi, fdescdata, 0); 1833 } 1834 } 1835 mutex_exit(proc_lock); 1836 } 1837 1838 int 1839 fd_clone(file_t *fp, unsigned fd, int flag, const struct fileops *fops, 1840 void *data) 1841 { 1842 1843 fp->f_flag = flag; 1844 fp->f_type = DTYPE_MISC; 1845 fp->f_ops = fops; 1846 fp->f_data = data; 1847 curlwp->l_dupfd = fd; 1848 fd_affix(curproc, fp, fd); 1849 1850 return EMOVEFD; 1851 } 1852 1853 int 1854 fnullop_fcntl(file_t *fp, u_int cmd, void *data) 1855 { 1856 1857 if (cmd == F_SETFL) 1858 return 0; 1859 1860 return EOPNOTSUPP; 1861 } 1862 1863 int 1864 fnullop_poll(file_t *fp, int which) 1865 { 1866 1867 return 0; 1868 } 1869 1870 int 1871 fnullop_kqfilter(file_t *fp, struct knote *kn) 1872 { 1873 1874 return 0; 1875 } 1876 1877 void 1878 fnullop_restart(file_t *fp) 1879 { 1880 1881 } 1882 1883 int 1884 fbadop_read(file_t *fp, off_t *offset, struct uio *uio, 1885 kauth_cred_t cred, int flags) 1886 { 1887 1888 return EOPNOTSUPP; 1889 } 1890 1891 int 1892 fbadop_write(file_t *fp, off_t *offset, struct uio *uio, 1893 kauth_cred_t cred, int flags) 1894 { 1895 1896 return EOPNOTSUPP; 1897 } 1898 1899 int 1900 fbadop_ioctl(file_t *fp, u_long com, void *data) 1901 { 1902 1903 return EOPNOTSUPP; 1904 } 1905 1906 int 1907 fbadop_stat(file_t *fp, struct stat *sb) 1908 { 1909 1910 return EOPNOTSUPP; 1911 } 1912 1913 int 1914 fbadop_close(file_t *fp) 1915 { 1916 1917 return EOPNOTSUPP; 1918 } 1919 1920 /* 1921 * sysctl routines pertaining to file descriptors 1922 */ 1923 1924 /* Initialized in sysctl_init() for now... */ 1925 extern kmutex_t sysctl_file_marker_lock; 1926 static u_int sysctl_file_marker = 1; 1927 1928 /* 1929 * Expects to be called with proc_lock and sysctl_file_marker_lock locked. 1930 */ 1931 static void 1932 sysctl_file_marker_reset(void) 1933 { 1934 struct proc *p; 1935 1936 PROCLIST_FOREACH(p, &allproc) { 1937 struct filedesc *fd = p->p_fd; 1938 fdtab_t *dt; 1939 u_int i; 1940 1941 mutex_enter(&fd->fd_lock); 1942 1943 dt = fd->fd_dt; 1944 for (i = 0; i < dt->dt_nfiles; i++) { 1945 struct file *fp; 1946 fdfile_t *ff; 1947 1948 if ((ff = dt->dt_ff[i]) == NULL) { 1949 continue; 1950 } 1951 1952 if ((fp = ff->ff_file) == NULL) { 1953 continue; 1954 } 1955 1956 fp->f_marker = 0; 1957 } 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