| 1 | /* $NetBSD: kern_descrip.c,v 1.229 2015/08/03 04:55:15 christos Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Andrew Doran. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * Copyright (c) 1982, 1986, 1989, 1991, 1993 |
| 34 | * The Regents of the University of California. All rights reserved. |
| 35 | * (c) UNIX System Laboratories, Inc. |
| 36 | * All or some portions of this file are derived from material licensed |
| 37 | * to the University of California by American Telephone and Telegraph |
| 38 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 39 | * the permission of UNIX System Laboratories, Inc. |
| 40 | * |
| 41 | * Redistribution and use in source and binary forms, with or without |
| 42 | * modification, are permitted provided that the following conditions |
| 43 | * are met: |
| 44 | * 1. Redistributions of source code must retain the above copyright |
| 45 | * notice, this list of conditions and the following disclaimer. |
| 46 | * 2. Redistributions in binary form must reproduce the above copyright |
| 47 | * notice, this list of conditions and the following disclaimer in the |
| 48 | * documentation and/or other materials provided with the distribution. |
| 49 | * 3. Neither the name of the University nor the names of its contributors |
| 50 | * may be used to endorse or promote products derived from this software |
| 51 | * without specific prior written permission. |
| 52 | * |
| 53 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 54 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 55 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 56 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 57 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 58 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 59 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 60 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 61 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 62 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 63 | * SUCH DAMAGE. |
| 64 | * |
| 65 | * @(#)kern_descrip.c 8.8 (Berkeley) 2/14/95 |
| 66 | */ |
| 67 | |
| 68 | /* |
| 69 | * File descriptor management. |
| 70 | */ |
| 71 | |
| 72 | #include <sys/cdefs.h> |
| 73 | __KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.229 2015/08/03 04:55:15 christos Exp $" ); |
| 74 | |
| 75 | #include <sys/param.h> |
| 76 | #include <sys/systm.h> |
| 77 | #include <sys/filedesc.h> |
| 78 | #include <sys/kernel.h> |
| 79 | #include <sys/proc.h> |
| 80 | #include <sys/file.h> |
| 81 | #include <sys/socket.h> |
| 82 | #include <sys/socketvar.h> |
| 83 | #include <sys/stat.h> |
| 84 | #include <sys/ioctl.h> |
| 85 | #include <sys/fcntl.h> |
| 86 | #include <sys/pool.h> |
| 87 | #include <sys/unistd.h> |
| 88 | #include <sys/resourcevar.h> |
| 89 | #include <sys/conf.h> |
| 90 | #include <sys/event.h> |
| 91 | #include <sys/kauth.h> |
| 92 | #include <sys/atomic.h> |
| 93 | #include <sys/syscallargs.h> |
| 94 | #include <sys/cpu.h> |
| 95 | #include <sys/kmem.h> |
| 96 | #include <sys/vnode.h> |
| 97 | #include <sys/sysctl.h> |
| 98 | #include <sys/ktrace.h> |
| 99 | |
| 100 | /* |
| 101 | * A list (head) of open files, counter, and lock protecting them. |
| 102 | */ |
| 103 | struct filelist filehead __cacheline_aligned; |
| 104 | static u_int nfiles __cacheline_aligned; |
| 105 | kmutex_t filelist_lock __cacheline_aligned; |
| 106 | |
| 107 | static pool_cache_t filedesc_cache __read_mostly; |
| 108 | static pool_cache_t file_cache __read_mostly; |
| 109 | static pool_cache_t fdfile_cache __read_mostly; |
| 110 | |
| 111 | static int file_ctor(void *, void *, int); |
| 112 | static void file_dtor(void *, void *); |
| 113 | static int fdfile_ctor(void *, void *, int); |
| 114 | static void fdfile_dtor(void *, void *); |
| 115 | static int filedesc_ctor(void *, void *, int); |
| 116 | static void filedesc_dtor(void *, void *); |
| 117 | static int filedescopen(dev_t, int, int, lwp_t *); |
| 118 | |
| 119 | static int sysctl_kern_file(SYSCTLFN_PROTO); |
| 120 | static int sysctl_kern_file2(SYSCTLFN_PROTO); |
| 121 | static void fill_file(struct kinfo_file *, const file_t *, const fdfile_t *, |
| 122 | int, pid_t); |
| 123 | |
| 124 | const struct cdevsw filedesc_cdevsw = { |
| 125 | .d_open = filedescopen, |
| 126 | .d_close = noclose, |
| 127 | .d_read = noread, |
| 128 | .d_write = nowrite, |
| 129 | .d_ioctl = noioctl, |
| 130 | .d_stop = nostop, |
| 131 | .d_tty = notty, |
| 132 | .d_poll = nopoll, |
| 133 | .d_mmap = nommap, |
| 134 | .d_kqfilter = nokqfilter, |
| 135 | .d_discard = nodiscard, |
| 136 | .d_flag = D_OTHER | D_MPSAFE |
| 137 | }; |
| 138 | |
| 139 | /* For ease of reading. */ |
| 140 | __strong_alias(fd_putvnode,fd_putfile) |
| 141 | __strong_alias(fd_putsock,fd_putfile) |
| 142 | |
| 143 | /* |
| 144 | * Initialize the descriptor system. |
| 145 | */ |
| 146 | void |
| 147 | fd_sys_init(void) |
| 148 | { |
| 149 | static struct sysctllog *clog; |
| 150 | |
| 151 | mutex_init(&filelist_lock, MUTEX_DEFAULT, IPL_NONE); |
| 152 | |
| 153 | file_cache = pool_cache_init(sizeof(file_t), coherency_unit, 0, |
| 154 | 0, "file" , NULL, IPL_NONE, file_ctor, file_dtor, NULL); |
| 155 | KASSERT(file_cache != NULL); |
| 156 | |
| 157 | fdfile_cache = pool_cache_init(sizeof(fdfile_t), coherency_unit, 0, |
| 158 | PR_LARGECACHE, "fdfile" , NULL, IPL_NONE, fdfile_ctor, fdfile_dtor, |
| 159 | NULL); |
| 160 | KASSERT(fdfile_cache != NULL); |
| 161 | |
| 162 | filedesc_cache = pool_cache_init(sizeof(filedesc_t), coherency_unit, |
| 163 | 0, 0, "filedesc" , NULL, IPL_NONE, filedesc_ctor, filedesc_dtor, |
| 164 | NULL); |
| 165 | KASSERT(filedesc_cache != NULL); |
| 166 | |
| 167 | sysctl_createv(&clog, 0, NULL, NULL, |
| 168 | CTLFLAG_PERMANENT, |
| 169 | CTLTYPE_STRUCT, "file" , |
| 170 | SYSCTL_DESCR("System open file table" ), |
| 171 | sysctl_kern_file, 0, NULL, 0, |
| 172 | CTL_KERN, KERN_FILE, CTL_EOL); |
| 173 | sysctl_createv(&clog, 0, NULL, NULL, |
| 174 | CTLFLAG_PERMANENT, |
| 175 | CTLTYPE_STRUCT, "file2" , |
| 176 | SYSCTL_DESCR("System open file table" ), |
| 177 | sysctl_kern_file2, 0, NULL, 0, |
| 178 | CTL_KERN, KERN_FILE2, CTL_EOL); |
| 179 | } |
| 180 | |
| 181 | static bool |
| 182 | fd_isused(filedesc_t *fdp, unsigned fd) |
| 183 | { |
| 184 | u_int off = fd >> NDENTRYSHIFT; |
| 185 | |
| 186 | KASSERT(fd < fdp->fd_dt->dt_nfiles); |
| 187 | |
| 188 | return (fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0; |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Verify that the bitmaps match the descriptor table. |
| 193 | */ |
| 194 | static inline void |
| 195 | fd_checkmaps(filedesc_t *fdp) |
| 196 | { |
| 197 | #ifdef DEBUG |
| 198 | fdtab_t *dt; |
| 199 | u_int fd; |
| 200 | |
| 201 | dt = fdp->fd_dt; |
| 202 | if (fdp->fd_refcnt == -1) { |
| 203 | /* |
| 204 | * fd_free tears down the table without maintaining its bitmap. |
| 205 | */ |
| 206 | return; |
| 207 | } |
| 208 | for (fd = 0; fd < dt->dt_nfiles; fd++) { |
| 209 | if (fd < NDFDFILE) { |
| 210 | KASSERT(dt->dt_ff[fd] == |
| 211 | (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 212 | } |
| 213 | if (dt->dt_ff[fd] == NULL) { |
| 214 | KASSERT(!fd_isused(fdp, fd)); |
| 215 | } else if (dt->dt_ff[fd]->ff_file != NULL) { |
| 216 | KASSERT(fd_isused(fdp, fd)); |
| 217 | } |
| 218 | } |
| 219 | #endif |
| 220 | } |
| 221 | |
| 222 | static int |
| 223 | fd_next_zero(filedesc_t *fdp, uint32_t *bitmap, int want, u_int bits) |
| 224 | { |
| 225 | int i, off, maxoff; |
| 226 | uint32_t sub; |
| 227 | |
| 228 | KASSERT(mutex_owned(&fdp->fd_lock)); |
| 229 | |
| 230 | fd_checkmaps(fdp); |
| 231 | |
| 232 | if (want > bits) |
| 233 | return -1; |
| 234 | |
| 235 | off = want >> NDENTRYSHIFT; |
| 236 | i = want & NDENTRYMASK; |
| 237 | if (i) { |
| 238 | sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); |
| 239 | if (sub != ~0) |
| 240 | goto found; |
| 241 | off++; |
| 242 | } |
| 243 | |
| 244 | maxoff = NDLOSLOTS(bits); |
| 245 | while (off < maxoff) { |
| 246 | if ((sub = bitmap[off]) != ~0) |
| 247 | goto found; |
| 248 | off++; |
| 249 | } |
| 250 | |
| 251 | return -1; |
| 252 | |
| 253 | found: |
| 254 | return (off << NDENTRYSHIFT) + ffs(~sub) - 1; |
| 255 | } |
| 256 | |
| 257 | static int |
| 258 | fd_last_set(filedesc_t *fd, int last) |
| 259 | { |
| 260 | int off, i; |
| 261 | fdfile_t **ff = fd->fd_dt->dt_ff; |
| 262 | uint32_t *bitmap = fd->fd_lomap; |
| 263 | |
| 264 | KASSERT(mutex_owned(&fd->fd_lock)); |
| 265 | |
| 266 | fd_checkmaps(fd); |
| 267 | |
| 268 | off = (last - 1) >> NDENTRYSHIFT; |
| 269 | |
| 270 | while (off >= 0 && !bitmap[off]) |
| 271 | off--; |
| 272 | |
| 273 | if (off < 0) |
| 274 | return -1; |
| 275 | |
| 276 | i = ((off + 1) << NDENTRYSHIFT) - 1; |
| 277 | if (i >= last) |
| 278 | i = last - 1; |
| 279 | |
| 280 | /* XXX should use bitmap */ |
| 281 | while (i > 0 && (ff[i] == NULL || !ff[i]->ff_allocated)) |
| 282 | i--; |
| 283 | |
| 284 | return i; |
| 285 | } |
| 286 | |
| 287 | static inline void |
| 288 | fd_used(filedesc_t *fdp, unsigned fd) |
| 289 | { |
| 290 | u_int off = fd >> NDENTRYSHIFT; |
| 291 | fdfile_t *ff; |
| 292 | |
| 293 | ff = fdp->fd_dt->dt_ff[fd]; |
| 294 | |
| 295 | KASSERT(mutex_owned(&fdp->fd_lock)); |
| 296 | KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) == 0); |
| 297 | KASSERT(ff != NULL); |
| 298 | KASSERT(ff->ff_file == NULL); |
| 299 | KASSERT(!ff->ff_allocated); |
| 300 | |
| 301 | ff->ff_allocated = true; |
| 302 | fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK); |
| 303 | if (__predict_false(fdp->fd_lomap[off] == ~0)) { |
| 304 | KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & |
| 305 | (1 << (off & NDENTRYMASK))) == 0); |
| 306 | fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK); |
| 307 | } |
| 308 | |
| 309 | if ((int)fd > fdp->fd_lastfile) { |
| 310 | fdp->fd_lastfile = fd; |
| 311 | } |
| 312 | |
| 313 | fd_checkmaps(fdp); |
| 314 | } |
| 315 | |
| 316 | static inline void |
| 317 | fd_unused(filedesc_t *fdp, unsigned fd) |
| 318 | { |
| 319 | u_int off = fd >> NDENTRYSHIFT; |
| 320 | fdfile_t *ff; |
| 321 | |
| 322 | ff = fdp->fd_dt->dt_ff[fd]; |
| 323 | |
| 324 | /* |
| 325 | * Don't assert the lock is held here, as we may be copying |
| 326 | * the table during exec() and it is not needed there. |
| 327 | * procfs and sysctl are locked out by proc::p_reflock. |
| 328 | * |
| 329 | * KASSERT(mutex_owned(&fdp->fd_lock)); |
| 330 | */ |
| 331 | KASSERT(ff != NULL); |
| 332 | KASSERT(ff->ff_file == NULL); |
| 333 | KASSERT(ff->ff_allocated); |
| 334 | |
| 335 | if (fd < fdp->fd_freefile) { |
| 336 | fdp->fd_freefile = fd; |
| 337 | } |
| 338 | |
| 339 | if (fdp->fd_lomap[off] == ~0) { |
| 340 | KASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & |
| 341 | (1 << (off & NDENTRYMASK))) != 0); |
| 342 | fdp->fd_himap[off >> NDENTRYSHIFT] &= |
| 343 | ~(1 << (off & NDENTRYMASK)); |
| 344 | } |
| 345 | KASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0); |
| 346 | fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK)); |
| 347 | ff->ff_allocated = false; |
| 348 | |
| 349 | KASSERT(fd <= fdp->fd_lastfile); |
| 350 | if (fd == fdp->fd_lastfile) { |
| 351 | fdp->fd_lastfile = fd_last_set(fdp, fd); |
| 352 | } |
| 353 | fd_checkmaps(fdp); |
| 354 | } |
| 355 | |
| 356 | /* |
| 357 | * Look up the file structure corresponding to a file descriptor |
| 358 | * and return the file, holding a reference on the descriptor. |
| 359 | */ |
| 360 | file_t * |
| 361 | fd_getfile(unsigned fd) |
| 362 | { |
| 363 | filedesc_t *fdp; |
| 364 | fdfile_t *ff; |
| 365 | file_t *fp; |
| 366 | fdtab_t *dt; |
| 367 | |
| 368 | /* |
| 369 | * Look up the fdfile structure representing this descriptor. |
| 370 | * We are doing this unlocked. See fd_tryexpand(). |
| 371 | */ |
| 372 | fdp = curlwp->l_fd; |
| 373 | dt = fdp->fd_dt; |
| 374 | if (__predict_false(fd >= dt->dt_nfiles)) { |
| 375 | return NULL; |
| 376 | } |
| 377 | ff = dt->dt_ff[fd]; |
| 378 | KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 379 | if (__predict_false(ff == NULL)) { |
| 380 | return NULL; |
| 381 | } |
| 382 | |
| 383 | /* Now get a reference to the descriptor. */ |
| 384 | if (fdp->fd_refcnt == 1) { |
| 385 | /* |
| 386 | * Single threaded: don't need to worry about concurrent |
| 387 | * access (other than earlier calls to kqueue, which may |
| 388 | * hold a reference to the descriptor). |
| 389 | */ |
| 390 | ff->ff_refcnt++; |
| 391 | } else { |
| 392 | /* |
| 393 | * Multi threaded: issue a memory barrier to ensure that we |
| 394 | * acquire the file pointer _after_ adding a reference. If |
| 395 | * no memory barrier, we could fetch a stale pointer. |
| 396 | */ |
| 397 | atomic_inc_uint(&ff->ff_refcnt); |
| 398 | #ifndef __HAVE_ATOMIC_AS_MEMBAR |
| 399 | membar_enter(); |
| 400 | #endif |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * If the file is not open or is being closed then put the |
| 405 | * reference back. |
| 406 | */ |
| 407 | fp = ff->ff_file; |
| 408 | if (__predict_true(fp != NULL)) { |
| 409 | return fp; |
| 410 | } |
| 411 | fd_putfile(fd); |
| 412 | return NULL; |
| 413 | } |
| 414 | |
| 415 | /* |
| 416 | * Release a reference to a file descriptor acquired with fd_getfile(). |
| 417 | */ |
| 418 | void |
| 419 | fd_putfile(unsigned fd) |
| 420 | { |
| 421 | filedesc_t *fdp; |
| 422 | fdfile_t *ff; |
| 423 | u_int u, v; |
| 424 | |
| 425 | fdp = curlwp->l_fd; |
| 426 | ff = fdp->fd_dt->dt_ff[fd]; |
| 427 | |
| 428 | KASSERT(fd < fdp->fd_dt->dt_nfiles); |
| 429 | KASSERT(ff != NULL); |
| 430 | KASSERT((ff->ff_refcnt & FR_MASK) > 0); |
| 431 | KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 432 | |
| 433 | if (fdp->fd_refcnt == 1) { |
| 434 | /* |
| 435 | * Single threaded: don't need to worry about concurrent |
| 436 | * access (other than earlier calls to kqueue, which may |
| 437 | * hold a reference to the descriptor). |
| 438 | */ |
| 439 | if (__predict_false((ff->ff_refcnt & FR_CLOSING) != 0)) { |
| 440 | fd_close(fd); |
| 441 | return; |
| 442 | } |
| 443 | ff->ff_refcnt--; |
| 444 | return; |
| 445 | } |
| 446 | |
| 447 | /* |
| 448 | * Ensure that any use of the file is complete and globally |
| 449 | * visible before dropping the final reference. If no membar, |
| 450 | * the current CPU could still access memory associated with |
| 451 | * the file after it has been freed or recycled by another |
| 452 | * CPU. |
| 453 | */ |
| 454 | #ifndef __HAVE_ATOMIC_AS_MEMBAR |
| 455 | membar_exit(); |
| 456 | #endif |
| 457 | |
| 458 | /* |
| 459 | * Be optimistic and start out with the assumption that no other |
| 460 | * threads are trying to close the descriptor. If the CAS fails, |
| 461 | * we lost a race and/or it's being closed. |
| 462 | */ |
| 463 | for (u = ff->ff_refcnt & FR_MASK;; u = v) { |
| 464 | v = atomic_cas_uint(&ff->ff_refcnt, u, u - 1); |
| 465 | if (__predict_true(u == v)) { |
| 466 | return; |
| 467 | } |
| 468 | if (__predict_false((v & FR_CLOSING) != 0)) { |
| 469 | break; |
| 470 | } |
| 471 | } |
| 472 | |
| 473 | /* Another thread is waiting to close the file: join it. */ |
| 474 | (void)fd_close(fd); |
| 475 | } |
| 476 | |
| 477 | /* |
| 478 | * Convenience wrapper around fd_getfile() that returns reference |
| 479 | * to a vnode. |
| 480 | */ |
| 481 | int |
| 482 | fd_getvnode(unsigned fd, file_t **fpp) |
| 483 | { |
| 484 | vnode_t *vp; |
| 485 | file_t *fp; |
| 486 | |
| 487 | fp = fd_getfile(fd); |
| 488 | if (__predict_false(fp == NULL)) { |
| 489 | return EBADF; |
| 490 | } |
| 491 | if (__predict_false(fp->f_type != DTYPE_VNODE)) { |
| 492 | fd_putfile(fd); |
| 493 | return EINVAL; |
| 494 | } |
| 495 | vp = fp->f_vnode; |
| 496 | if (__predict_false(vp->v_type == VBAD)) { |
| 497 | /* XXX Is this case really necessary? */ |
| 498 | fd_putfile(fd); |
| 499 | return EBADF; |
| 500 | } |
| 501 | *fpp = fp; |
| 502 | return 0; |
| 503 | } |
| 504 | |
| 505 | /* |
| 506 | * Convenience wrapper around fd_getfile() that returns reference |
| 507 | * to a socket. |
| 508 | */ |
| 509 | int |
| 510 | fd_getsock1(unsigned fd, struct socket **sop, file_t **fp) |
| 511 | { |
| 512 | *fp = fd_getfile(fd); |
| 513 | if (__predict_false(*fp == NULL)) { |
| 514 | return EBADF; |
| 515 | } |
| 516 | if (__predict_false((*fp)->f_type != DTYPE_SOCKET)) { |
| 517 | fd_putfile(fd); |
| 518 | return ENOTSOCK; |
| 519 | } |
| 520 | *sop = (*fp)->f_socket; |
| 521 | return 0; |
| 522 | } |
| 523 | |
| 524 | int |
| 525 | fd_getsock(unsigned fd, struct socket **sop) |
| 526 | { |
| 527 | file_t *fp; |
| 528 | return fd_getsock1(fd, sop, &fp); |
| 529 | } |
| 530 | |
| 531 | /* |
| 532 | * Look up the file structure corresponding to a file descriptor |
| 533 | * and return it with a reference held on the file, not the |
| 534 | * descriptor. |
| 535 | * |
| 536 | * This is heavyweight and only used when accessing descriptors |
| 537 | * from a foreign process. The caller must ensure that `p' does |
| 538 | * not exit or fork across this call. |
| 539 | * |
| 540 | * To release the file (not descriptor) reference, use closef(). |
| 541 | */ |
| 542 | file_t * |
| 543 | fd_getfile2(proc_t *p, unsigned fd) |
| 544 | { |
| 545 | filedesc_t *fdp; |
| 546 | fdfile_t *ff; |
| 547 | file_t *fp; |
| 548 | fdtab_t *dt; |
| 549 | |
| 550 | fdp = p->p_fd; |
| 551 | mutex_enter(&fdp->fd_lock); |
| 552 | dt = fdp->fd_dt; |
| 553 | if (fd >= dt->dt_nfiles) { |
| 554 | mutex_exit(&fdp->fd_lock); |
| 555 | return NULL; |
| 556 | } |
| 557 | if ((ff = dt->dt_ff[fd]) == NULL) { |
| 558 | mutex_exit(&fdp->fd_lock); |
| 559 | return NULL; |
| 560 | } |
| 561 | if ((fp = ff->ff_file) == NULL) { |
| 562 | mutex_exit(&fdp->fd_lock); |
| 563 | return NULL; |
| 564 | } |
| 565 | mutex_enter(&fp->f_lock); |
| 566 | fp->f_count++; |
| 567 | mutex_exit(&fp->f_lock); |
| 568 | mutex_exit(&fdp->fd_lock); |
| 569 | |
| 570 | return fp; |
| 571 | } |
| 572 | |
| 573 | /* |
| 574 | * Internal form of close. Must be called with a reference to the |
| 575 | * descriptor, and will drop the reference. When all descriptor |
| 576 | * references are dropped, releases the descriptor slot and a single |
| 577 | * reference to the file structure. |
| 578 | */ |
| 579 | int |
| 580 | fd_close(unsigned fd) |
| 581 | { |
| 582 | struct flock lf; |
| 583 | filedesc_t *fdp; |
| 584 | fdfile_t *ff; |
| 585 | file_t *fp; |
| 586 | proc_t *p; |
| 587 | lwp_t *l; |
| 588 | u_int refcnt; |
| 589 | |
| 590 | l = curlwp; |
| 591 | p = l->l_proc; |
| 592 | fdp = l->l_fd; |
| 593 | ff = fdp->fd_dt->dt_ff[fd]; |
| 594 | |
| 595 | KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 596 | |
| 597 | mutex_enter(&fdp->fd_lock); |
| 598 | KASSERT((ff->ff_refcnt & FR_MASK) > 0); |
| 599 | if (__predict_false(ff->ff_file == NULL)) { |
| 600 | /* |
| 601 | * Another user of the file is already closing, and is |
| 602 | * waiting for other users of the file to drain. Release |
| 603 | * our reference, and wake up the closer. |
| 604 | */ |
| 605 | atomic_dec_uint(&ff->ff_refcnt); |
| 606 | cv_broadcast(&ff->ff_closing); |
| 607 | mutex_exit(&fdp->fd_lock); |
| 608 | |
| 609 | /* |
| 610 | * An application error, so pretend that the descriptor |
| 611 | * was already closed. We can't safely wait for it to |
| 612 | * be closed without potentially deadlocking. |
| 613 | */ |
| 614 | return (EBADF); |
| 615 | } |
| 616 | KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); |
| 617 | |
| 618 | /* |
| 619 | * There may be multiple users of this file within the process. |
| 620 | * Notify existing and new users that the file is closing. This |
| 621 | * will prevent them from adding additional uses to this file |
| 622 | * while we are closing it. |
| 623 | */ |
| 624 | fp = ff->ff_file; |
| 625 | ff->ff_file = NULL; |
| 626 | ff->ff_exclose = false; |
| 627 | |
| 628 | /* |
| 629 | * We expect the caller to hold a descriptor reference - drop it. |
| 630 | * The reference count may increase beyond zero at this point due |
| 631 | * to an erroneous descriptor reference by an application, but |
| 632 | * fd_getfile() will notice that the file is being closed and drop |
| 633 | * the reference again. |
| 634 | */ |
| 635 | if (fdp->fd_refcnt == 1) { |
| 636 | /* Single threaded. */ |
| 637 | refcnt = --(ff->ff_refcnt); |
| 638 | } else { |
| 639 | /* Multi threaded. */ |
| 640 | #ifndef __HAVE_ATOMIC_AS_MEMBAR |
| 641 | membar_producer(); |
| 642 | #endif |
| 643 | refcnt = atomic_dec_uint_nv(&ff->ff_refcnt); |
| 644 | } |
| 645 | if (__predict_false(refcnt != 0)) { |
| 646 | /* |
| 647 | * Wait for other references to drain. This is typically |
| 648 | * an application error - the descriptor is being closed |
| 649 | * while still in use. |
| 650 | * (Or just a threaded application trying to unblock its |
| 651 | * thread that sleeps in (say) accept()). |
| 652 | */ |
| 653 | atomic_or_uint(&ff->ff_refcnt, FR_CLOSING); |
| 654 | |
| 655 | /* |
| 656 | * Remove any knotes attached to the file. A knote |
| 657 | * attached to the descriptor can hold references on it. |
| 658 | */ |
| 659 | mutex_exit(&fdp->fd_lock); |
| 660 | if (!SLIST_EMPTY(&ff->ff_knlist)) { |
| 661 | knote_fdclose(fd); |
| 662 | } |
| 663 | |
| 664 | /* |
| 665 | * Since the file system code doesn't know which fd |
| 666 | * each request came from (think dup()), we have to |
| 667 | * ask it to return ERESTART for any long-term blocks. |
| 668 | * The re-entry through read/write/etc will detect the |
| 669 | * closed fd and return EBAFD. |
| 670 | * Blocked partial writes may return a short length. |
| 671 | */ |
| 672 | (*fp->f_ops->fo_restart)(fp); |
| 673 | mutex_enter(&fdp->fd_lock); |
| 674 | |
| 675 | /* |
| 676 | * We need to see the count drop to zero at least once, |
| 677 | * in order to ensure that all pre-existing references |
| 678 | * have been drained. New references past this point are |
| 679 | * of no interest. |
| 680 | * XXX (dsl) this may need to call fo_restart() after a |
| 681 | * timeout to guarantee that all the system calls exit. |
| 682 | */ |
| 683 | while ((ff->ff_refcnt & FR_MASK) != 0) { |
| 684 | cv_wait(&ff->ff_closing, &fdp->fd_lock); |
| 685 | } |
| 686 | atomic_and_uint(&ff->ff_refcnt, ~FR_CLOSING); |
| 687 | } else { |
| 688 | /* If no references, there must be no knotes. */ |
| 689 | KASSERT(SLIST_EMPTY(&ff->ff_knlist)); |
| 690 | } |
| 691 | |
| 692 | /* |
| 693 | * POSIX record locking dictates that any close releases ALL |
| 694 | * locks owned by this process. This is handled by setting |
| 695 | * a flag in the unlock to free ONLY locks obeying POSIX |
| 696 | * semantics, and not to free BSD-style file locks. |
| 697 | * If the descriptor was in a message, POSIX-style locks |
| 698 | * aren't passed with the descriptor. |
| 699 | */ |
| 700 | if (__predict_false((p->p_flag & PK_ADVLOCK) != 0 && |
| 701 | fp->f_type == DTYPE_VNODE)) { |
| 702 | lf.l_whence = SEEK_SET; |
| 703 | lf.l_start = 0; |
| 704 | lf.l_len = 0; |
| 705 | lf.l_type = F_UNLCK; |
| 706 | mutex_exit(&fdp->fd_lock); |
| 707 | (void)VOP_ADVLOCK(fp->f_vnode, p, F_UNLCK, &lf, F_POSIX); |
| 708 | mutex_enter(&fdp->fd_lock); |
| 709 | } |
| 710 | |
| 711 | /* Free descriptor slot. */ |
| 712 | fd_unused(fdp, fd); |
| 713 | mutex_exit(&fdp->fd_lock); |
| 714 | |
| 715 | /* Now drop reference to the file itself. */ |
| 716 | return closef(fp); |
| 717 | } |
| 718 | |
| 719 | /* |
| 720 | * Duplicate a file descriptor. |
| 721 | */ |
| 722 | int |
| 723 | fd_dup(file_t *fp, int minfd, int *newp, bool exclose) |
| 724 | { |
| 725 | proc_t *p = curproc; |
| 726 | int error; |
| 727 | |
| 728 | while ((error = fd_alloc(p, minfd, newp)) != 0) { |
| 729 | if (error != ENOSPC) { |
| 730 | return error; |
| 731 | } |
| 732 | fd_tryexpand(p); |
| 733 | } |
| 734 | |
| 735 | curlwp->l_fd->fd_dt->dt_ff[*newp]->ff_exclose = exclose; |
| 736 | fd_affix(p, fp, *newp); |
| 737 | return 0; |
| 738 | } |
| 739 | |
| 740 | /* |
| 741 | * dup2 operation. |
| 742 | */ |
| 743 | int |
| 744 | fd_dup2(file_t *fp, unsigned newfd, int flags) |
| 745 | { |
| 746 | filedesc_t *fdp = curlwp->l_fd; |
| 747 | fdfile_t *ff; |
| 748 | fdtab_t *dt; |
| 749 | |
| 750 | if (flags & ~(O_CLOEXEC|O_NONBLOCK)) |
| 751 | return EINVAL; |
| 752 | /* |
| 753 | * Ensure there are enough slots in the descriptor table, |
| 754 | * and allocate an fdfile_t up front in case we need it. |
| 755 | */ |
| 756 | while (newfd >= fdp->fd_dt->dt_nfiles) { |
| 757 | fd_tryexpand(curproc); |
| 758 | } |
| 759 | ff = pool_cache_get(fdfile_cache, PR_WAITOK); |
| 760 | |
| 761 | /* |
| 762 | * If there is already a file open, close it. If the file is |
| 763 | * half open, wait for it to be constructed before closing it. |
| 764 | * XXX Potential for deadlock here? |
| 765 | */ |
| 766 | mutex_enter(&fdp->fd_lock); |
| 767 | while (fd_isused(fdp, newfd)) { |
| 768 | mutex_exit(&fdp->fd_lock); |
| 769 | if (fd_getfile(newfd) != NULL) { |
| 770 | (void)fd_close(newfd); |
| 771 | } else { |
| 772 | /* |
| 773 | * Crummy, but unlikely to happen. |
| 774 | * Can occur if we interrupt another |
| 775 | * thread while it is opening a file. |
| 776 | */ |
| 777 | kpause("dup2" , false, 1, NULL); |
| 778 | } |
| 779 | mutex_enter(&fdp->fd_lock); |
| 780 | } |
| 781 | dt = fdp->fd_dt; |
| 782 | if (dt->dt_ff[newfd] == NULL) { |
| 783 | KASSERT(newfd >= NDFDFILE); |
| 784 | dt->dt_ff[newfd] = ff; |
| 785 | ff = NULL; |
| 786 | } |
| 787 | fd_used(fdp, newfd); |
| 788 | mutex_exit(&fdp->fd_lock); |
| 789 | |
| 790 | dt->dt_ff[newfd]->ff_exclose = (flags & O_CLOEXEC) != 0; |
| 791 | fp->f_flag |= flags & FNONBLOCK; |
| 792 | /* Slot is now allocated. Insert copy of the file. */ |
| 793 | fd_affix(curproc, fp, newfd); |
| 794 | if (ff != NULL) { |
| 795 | pool_cache_put(fdfile_cache, ff); |
| 796 | } |
| 797 | return 0; |
| 798 | } |
| 799 | |
| 800 | /* |
| 801 | * Drop reference to a file structure. |
| 802 | */ |
| 803 | int |
| 804 | closef(file_t *fp) |
| 805 | { |
| 806 | struct flock lf; |
| 807 | int error; |
| 808 | |
| 809 | /* |
| 810 | * Drop reference. If referenced elsewhere it's still open |
| 811 | * and we have nothing more to do. |
| 812 | */ |
| 813 | mutex_enter(&fp->f_lock); |
| 814 | KASSERT(fp->f_count > 0); |
| 815 | if (--fp->f_count > 0) { |
| 816 | mutex_exit(&fp->f_lock); |
| 817 | return 0; |
| 818 | } |
| 819 | KASSERT(fp->f_count == 0); |
| 820 | mutex_exit(&fp->f_lock); |
| 821 | |
| 822 | /* We held the last reference - release locks, close and free. */ |
| 823 | if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { |
| 824 | lf.l_whence = SEEK_SET; |
| 825 | lf.l_start = 0; |
| 826 | lf.l_len = 0; |
| 827 | lf.l_type = F_UNLCK; |
| 828 | (void)VOP_ADVLOCK(fp->f_vnode, fp, F_UNLCK, &lf, F_FLOCK); |
| 829 | } |
| 830 | if (fp->f_ops != NULL) { |
| 831 | error = (*fp->f_ops->fo_close)(fp); |
| 832 | } else { |
| 833 | error = 0; |
| 834 | } |
| 835 | KASSERT(fp->f_count == 0); |
| 836 | KASSERT(fp->f_cred != NULL); |
| 837 | pool_cache_put(file_cache, fp); |
| 838 | |
| 839 | return error; |
| 840 | } |
| 841 | |
| 842 | /* |
| 843 | * Allocate a file descriptor for the process. |
| 844 | */ |
| 845 | int |
| 846 | fd_alloc(proc_t *p, int want, int *result) |
| 847 | { |
| 848 | filedesc_t *fdp = p->p_fd; |
| 849 | int i, lim, last, error, hi; |
| 850 | u_int off; |
| 851 | fdtab_t *dt; |
| 852 | |
| 853 | KASSERT(p == curproc || p == &proc0); |
| 854 | |
| 855 | /* |
| 856 | * Search for a free descriptor starting at the higher |
| 857 | * of want or fd_freefile. |
| 858 | */ |
| 859 | mutex_enter(&fdp->fd_lock); |
| 860 | fd_checkmaps(fdp); |
| 861 | dt = fdp->fd_dt; |
| 862 | KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); |
| 863 | lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); |
| 864 | last = min(dt->dt_nfiles, lim); |
| 865 | for (;;) { |
| 866 | if ((i = want) < fdp->fd_freefile) |
| 867 | i = fdp->fd_freefile; |
| 868 | off = i >> NDENTRYSHIFT; |
| 869 | hi = fd_next_zero(fdp, fdp->fd_himap, off, |
| 870 | (last + NDENTRIES - 1) >> NDENTRYSHIFT); |
| 871 | if (hi == -1) |
| 872 | break; |
| 873 | i = fd_next_zero(fdp, &fdp->fd_lomap[hi], |
| 874 | hi > off ? 0 : i & NDENTRYMASK, NDENTRIES); |
| 875 | if (i == -1) { |
| 876 | /* |
| 877 | * Free file descriptor in this block was |
| 878 | * below want, try again with higher want. |
| 879 | */ |
| 880 | want = (hi + 1) << NDENTRYSHIFT; |
| 881 | continue; |
| 882 | } |
| 883 | i += (hi << NDENTRYSHIFT); |
| 884 | if (i >= last) { |
| 885 | break; |
| 886 | } |
| 887 | if (dt->dt_ff[i] == NULL) { |
| 888 | KASSERT(i >= NDFDFILE); |
| 889 | dt->dt_ff[i] = pool_cache_get(fdfile_cache, PR_WAITOK); |
| 890 | } |
| 891 | KASSERT(dt->dt_ff[i]->ff_file == NULL); |
| 892 | fd_used(fdp, i); |
| 893 | if (want <= fdp->fd_freefile) { |
| 894 | fdp->fd_freefile = i; |
| 895 | } |
| 896 | *result = i; |
| 897 | KASSERT(i >= NDFDFILE || |
| 898 | dt->dt_ff[i] == (fdfile_t *)fdp->fd_dfdfile[i]); |
| 899 | fd_checkmaps(fdp); |
| 900 | mutex_exit(&fdp->fd_lock); |
| 901 | return 0; |
| 902 | } |
| 903 | |
| 904 | /* No space in current array. Let the caller expand and retry. */ |
| 905 | error = (dt->dt_nfiles >= lim) ? EMFILE : ENOSPC; |
| 906 | mutex_exit(&fdp->fd_lock); |
| 907 | return error; |
| 908 | } |
| 909 | |
| 910 | /* |
| 911 | * Allocate memory for a descriptor table. |
| 912 | */ |
| 913 | static fdtab_t * |
| 914 | fd_dtab_alloc(int n) |
| 915 | { |
| 916 | fdtab_t *dt; |
| 917 | size_t sz; |
| 918 | |
| 919 | KASSERT(n > NDFILE); |
| 920 | |
| 921 | sz = sizeof(*dt) + (n - NDFILE) * sizeof(dt->dt_ff[0]); |
| 922 | dt = kmem_alloc(sz, KM_SLEEP); |
| 923 | #ifdef DIAGNOSTIC |
| 924 | memset(dt, 0xff, sz); |
| 925 | #endif |
| 926 | dt->dt_nfiles = n; |
| 927 | dt->dt_link = NULL; |
| 928 | return dt; |
| 929 | } |
| 930 | |
| 931 | /* |
| 932 | * Free a descriptor table, and all tables linked for deferred free. |
| 933 | */ |
| 934 | static void |
| 935 | fd_dtab_free(fdtab_t *dt) |
| 936 | { |
| 937 | fdtab_t *next; |
| 938 | size_t sz; |
| 939 | |
| 940 | do { |
| 941 | next = dt->dt_link; |
| 942 | KASSERT(dt->dt_nfiles > NDFILE); |
| 943 | sz = sizeof(*dt) + |
| 944 | (dt->dt_nfiles - NDFILE) * sizeof(dt->dt_ff[0]); |
| 945 | #ifdef DIAGNOSTIC |
| 946 | memset(dt, 0xff, sz); |
| 947 | #endif |
| 948 | kmem_free(dt, sz); |
| 949 | dt = next; |
| 950 | } while (dt != NULL); |
| 951 | } |
| 952 | |
| 953 | /* |
| 954 | * Allocate descriptor bitmap. |
| 955 | */ |
| 956 | static void |
| 957 | fd_map_alloc(int n, uint32_t **lo, uint32_t **hi) |
| 958 | { |
| 959 | uint8_t *ptr; |
| 960 | size_t szlo, szhi; |
| 961 | |
| 962 | KASSERT(n > NDENTRIES); |
| 963 | |
| 964 | szlo = NDLOSLOTS(n) * sizeof(uint32_t); |
| 965 | szhi = NDHISLOTS(n) * sizeof(uint32_t); |
| 966 | ptr = kmem_alloc(szlo + szhi, KM_SLEEP); |
| 967 | *lo = (uint32_t *)ptr; |
| 968 | *hi = (uint32_t *)(ptr + szlo); |
| 969 | } |
| 970 | |
| 971 | /* |
| 972 | * Free descriptor bitmap. |
| 973 | */ |
| 974 | static void |
| 975 | fd_map_free(int n, uint32_t *lo, uint32_t *hi) |
| 976 | { |
| 977 | size_t szlo, szhi; |
| 978 | |
| 979 | KASSERT(n > NDENTRIES); |
| 980 | |
| 981 | szlo = NDLOSLOTS(n) * sizeof(uint32_t); |
| 982 | szhi = NDHISLOTS(n) * sizeof(uint32_t); |
| 983 | KASSERT(hi == (uint32_t *)((uint8_t *)lo + szlo)); |
| 984 | kmem_free(lo, szlo + szhi); |
| 985 | } |
| 986 | |
| 987 | /* |
| 988 | * Expand a process' descriptor table. |
| 989 | */ |
| 990 | void |
| 991 | fd_tryexpand(proc_t *p) |
| 992 | { |
| 993 | filedesc_t *fdp; |
| 994 | int i, numfiles, oldnfiles; |
| 995 | fdtab_t *newdt, *dt; |
| 996 | uint32_t *newhimap, *newlomap; |
| 997 | |
| 998 | KASSERT(p == curproc || p == &proc0); |
| 999 | |
| 1000 | fdp = p->p_fd; |
| 1001 | newhimap = NULL; |
| 1002 | newlomap = NULL; |
| 1003 | oldnfiles = fdp->fd_dt->dt_nfiles; |
| 1004 | |
| 1005 | if (oldnfiles < NDEXTENT) |
| 1006 | numfiles = NDEXTENT; |
| 1007 | else |
| 1008 | numfiles = 2 * oldnfiles; |
| 1009 | |
| 1010 | newdt = fd_dtab_alloc(numfiles); |
| 1011 | if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { |
| 1012 | fd_map_alloc(numfiles, &newlomap, &newhimap); |
| 1013 | } |
| 1014 | |
| 1015 | mutex_enter(&fdp->fd_lock); |
| 1016 | dt = fdp->fd_dt; |
| 1017 | KASSERT(dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); |
| 1018 | if (dt->dt_nfiles != oldnfiles) { |
| 1019 | /* fdp changed; caller must retry */ |
| 1020 | mutex_exit(&fdp->fd_lock); |
| 1021 | fd_dtab_free(newdt); |
| 1022 | if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { |
| 1023 | fd_map_free(numfiles, newlomap, newhimap); |
| 1024 | } |
| 1025 | return; |
| 1026 | } |
| 1027 | |
| 1028 | /* Copy the existing descriptor table and zero the new portion. */ |
| 1029 | i = sizeof(fdfile_t *) * oldnfiles; |
| 1030 | memcpy(newdt->dt_ff, dt->dt_ff, i); |
| 1031 | memset((uint8_t *)newdt->dt_ff + i, 0, |
| 1032 | numfiles * sizeof(fdfile_t *) - i); |
| 1033 | |
| 1034 | /* |
| 1035 | * Link old descriptor array into list to be discarded. We defer |
| 1036 | * freeing until the last reference to the descriptor table goes |
| 1037 | * away (usually process exit). This allows us to do lockless |
| 1038 | * lookups in fd_getfile(). |
| 1039 | */ |
| 1040 | if (oldnfiles > NDFILE) { |
| 1041 | if (fdp->fd_refcnt > 1) { |
| 1042 | newdt->dt_link = dt; |
| 1043 | } else { |
| 1044 | fd_dtab_free(dt); |
| 1045 | } |
| 1046 | } |
| 1047 | |
| 1048 | if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { |
| 1049 | i = NDHISLOTS(oldnfiles) * sizeof(uint32_t); |
| 1050 | memcpy(newhimap, fdp->fd_himap, i); |
| 1051 | memset((uint8_t *)newhimap + i, 0, |
| 1052 | NDHISLOTS(numfiles) * sizeof(uint32_t) - i); |
| 1053 | |
| 1054 | i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t); |
| 1055 | memcpy(newlomap, fdp->fd_lomap, i); |
| 1056 | memset((uint8_t *)newlomap + i, 0, |
| 1057 | NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); |
| 1058 | |
| 1059 | if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { |
| 1060 | fd_map_free(oldnfiles, fdp->fd_lomap, fdp->fd_himap); |
| 1061 | } |
| 1062 | fdp->fd_himap = newhimap; |
| 1063 | fdp->fd_lomap = newlomap; |
| 1064 | } |
| 1065 | |
| 1066 | /* |
| 1067 | * All other modifications must become globally visible before |
| 1068 | * the change to fd_dt. See fd_getfile(). |
| 1069 | */ |
| 1070 | membar_producer(); |
| 1071 | fdp->fd_dt = newdt; |
| 1072 | KASSERT(newdt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); |
| 1073 | fd_checkmaps(fdp); |
| 1074 | mutex_exit(&fdp->fd_lock); |
| 1075 | } |
| 1076 | |
| 1077 | /* |
| 1078 | * Create a new open file structure and allocate a file descriptor |
| 1079 | * for the current process. |
| 1080 | */ |
| 1081 | int |
| 1082 | fd_allocfile(file_t **resultfp, int *resultfd) |
| 1083 | { |
| 1084 | proc_t *p = curproc; |
| 1085 | kauth_cred_t cred; |
| 1086 | file_t *fp; |
| 1087 | int error; |
| 1088 | |
| 1089 | while ((error = fd_alloc(p, 0, resultfd)) != 0) { |
| 1090 | if (error != ENOSPC) { |
| 1091 | return error; |
| 1092 | } |
| 1093 | fd_tryexpand(p); |
| 1094 | } |
| 1095 | |
| 1096 | fp = pool_cache_get(file_cache, PR_WAITOK); |
| 1097 | if (fp == NULL) { |
| 1098 | fd_abort(p, NULL, *resultfd); |
| 1099 | return ENFILE; |
| 1100 | } |
| 1101 | KASSERT(fp->f_count == 0); |
| 1102 | KASSERT(fp->f_msgcount == 0); |
| 1103 | KASSERT(fp->f_unpcount == 0); |
| 1104 | |
| 1105 | /* Replace cached credentials if not what we need. */ |
| 1106 | cred = curlwp->l_cred; |
| 1107 | if (__predict_false(cred != fp->f_cred)) { |
| 1108 | kauth_cred_free(fp->f_cred); |
| 1109 | kauth_cred_hold(cred); |
| 1110 | fp->f_cred = cred; |
| 1111 | } |
| 1112 | |
| 1113 | /* |
| 1114 | * Don't allow recycled files to be scanned. |
| 1115 | * See uipc_usrreq.c. |
| 1116 | */ |
| 1117 | if (__predict_false((fp->f_flag & FSCAN) != 0)) { |
| 1118 | mutex_enter(&fp->f_lock); |
| 1119 | atomic_and_uint(&fp->f_flag, ~FSCAN); |
| 1120 | mutex_exit(&fp->f_lock); |
| 1121 | } |
| 1122 | |
| 1123 | fp->f_advice = 0; |
| 1124 | fp->f_offset = 0; |
| 1125 | *resultfp = fp; |
| 1126 | |
| 1127 | return 0; |
| 1128 | } |
| 1129 | |
| 1130 | /* |
| 1131 | * Successful creation of a new descriptor: make visible to the process. |
| 1132 | */ |
| 1133 | void |
| 1134 | fd_affix(proc_t *p, file_t *fp, unsigned fd) |
| 1135 | { |
| 1136 | fdfile_t *ff; |
| 1137 | filedesc_t *fdp; |
| 1138 | |
| 1139 | KASSERT(p == curproc || p == &proc0); |
| 1140 | |
| 1141 | /* Add a reference to the file structure. */ |
| 1142 | mutex_enter(&fp->f_lock); |
| 1143 | fp->f_count++; |
| 1144 | mutex_exit(&fp->f_lock); |
| 1145 | |
| 1146 | /* |
| 1147 | * Insert the new file into the descriptor slot. |
| 1148 | * |
| 1149 | * The memory barriers provided by lock activity in this routine |
| 1150 | * ensure that any updates to the file structure become globally |
| 1151 | * visible before the file becomes visible to other LWPs in the |
| 1152 | * current process. |
| 1153 | */ |
| 1154 | fdp = p->p_fd; |
| 1155 | ff = fdp->fd_dt->dt_ff[fd]; |
| 1156 | |
| 1157 | KASSERT(ff != NULL); |
| 1158 | KASSERT(ff->ff_file == NULL); |
| 1159 | KASSERT(ff->ff_allocated); |
| 1160 | KASSERT(fd_isused(fdp, fd)); |
| 1161 | KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 1162 | |
| 1163 | /* No need to lock in order to make file initially visible. */ |
| 1164 | ff->ff_file = fp; |
| 1165 | } |
| 1166 | |
| 1167 | /* |
| 1168 | * Abort creation of a new descriptor: free descriptor slot and file. |
| 1169 | */ |
| 1170 | void |
| 1171 | fd_abort(proc_t *p, file_t *fp, unsigned fd) |
| 1172 | { |
| 1173 | filedesc_t *fdp; |
| 1174 | fdfile_t *ff; |
| 1175 | |
| 1176 | KASSERT(p == curproc || p == &proc0); |
| 1177 | |
| 1178 | fdp = p->p_fd; |
| 1179 | ff = fdp->fd_dt->dt_ff[fd]; |
| 1180 | ff->ff_exclose = false; |
| 1181 | |
| 1182 | KASSERT(fd >= NDFDFILE || ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 1183 | |
| 1184 | mutex_enter(&fdp->fd_lock); |
| 1185 | KASSERT(fd_isused(fdp, fd)); |
| 1186 | fd_unused(fdp, fd); |
| 1187 | mutex_exit(&fdp->fd_lock); |
| 1188 | |
| 1189 | if (fp != NULL) { |
| 1190 | KASSERT(fp->f_count == 0); |
| 1191 | KASSERT(fp->f_cred != NULL); |
| 1192 | pool_cache_put(file_cache, fp); |
| 1193 | } |
| 1194 | } |
| 1195 | |
| 1196 | static int |
| 1197 | file_ctor(void *arg, void *obj, int flags) |
| 1198 | { |
| 1199 | file_t *fp = obj; |
| 1200 | |
| 1201 | memset(fp, 0, sizeof(*fp)); |
| 1202 | |
| 1203 | mutex_enter(&filelist_lock); |
| 1204 | if (__predict_false(nfiles >= maxfiles)) { |
| 1205 | mutex_exit(&filelist_lock); |
| 1206 | tablefull("file" , "increase kern.maxfiles or MAXFILES" ); |
| 1207 | return ENFILE; |
| 1208 | } |
| 1209 | nfiles++; |
| 1210 | LIST_INSERT_HEAD(&filehead, fp, f_list); |
| 1211 | mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); |
| 1212 | fp->f_cred = curlwp->l_cred; |
| 1213 | kauth_cred_hold(fp->f_cred); |
| 1214 | mutex_exit(&filelist_lock); |
| 1215 | |
| 1216 | return 0; |
| 1217 | } |
| 1218 | |
| 1219 | static void |
| 1220 | file_dtor(void *arg, void *obj) |
| 1221 | { |
| 1222 | file_t *fp = obj; |
| 1223 | |
| 1224 | mutex_enter(&filelist_lock); |
| 1225 | nfiles--; |
| 1226 | LIST_REMOVE(fp, f_list); |
| 1227 | mutex_exit(&filelist_lock); |
| 1228 | |
| 1229 | kauth_cred_free(fp->f_cred); |
| 1230 | mutex_destroy(&fp->f_lock); |
| 1231 | } |
| 1232 | |
| 1233 | static int |
| 1234 | fdfile_ctor(void *arg, void *obj, int flags) |
| 1235 | { |
| 1236 | fdfile_t *ff = obj; |
| 1237 | |
| 1238 | memset(ff, 0, sizeof(*ff)); |
| 1239 | cv_init(&ff->ff_closing, "fdclose" ); |
| 1240 | |
| 1241 | return 0; |
| 1242 | } |
| 1243 | |
| 1244 | static void |
| 1245 | fdfile_dtor(void *arg, void *obj) |
| 1246 | { |
| 1247 | fdfile_t *ff = obj; |
| 1248 | |
| 1249 | cv_destroy(&ff->ff_closing); |
| 1250 | } |
| 1251 | |
| 1252 | file_t * |
| 1253 | fgetdummy(void) |
| 1254 | { |
| 1255 | file_t *fp; |
| 1256 | |
| 1257 | fp = kmem_zalloc(sizeof(*fp), KM_SLEEP); |
| 1258 | if (fp != NULL) { |
| 1259 | mutex_init(&fp->f_lock, MUTEX_DEFAULT, IPL_NONE); |
| 1260 | } |
| 1261 | return fp; |
| 1262 | } |
| 1263 | |
| 1264 | void |
| 1265 | fputdummy(file_t *fp) |
| 1266 | { |
| 1267 | |
| 1268 | mutex_destroy(&fp->f_lock); |
| 1269 | kmem_free(fp, sizeof(*fp)); |
| 1270 | } |
| 1271 | |
| 1272 | /* |
| 1273 | * Create an initial filedesc structure. |
| 1274 | */ |
| 1275 | filedesc_t * |
| 1276 | fd_init(filedesc_t *fdp) |
| 1277 | { |
| 1278 | #ifdef DIAGNOSTIC |
| 1279 | unsigned fd; |
| 1280 | #endif |
| 1281 | |
| 1282 | if (__predict_true(fdp == NULL)) { |
| 1283 | fdp = pool_cache_get(filedesc_cache, PR_WAITOK); |
| 1284 | } else { |
| 1285 | KASSERT(fdp == &filedesc0); |
| 1286 | filedesc_ctor(NULL, fdp, PR_WAITOK); |
| 1287 | } |
| 1288 | |
| 1289 | #ifdef DIAGNOSTIC |
| 1290 | KASSERT(fdp->fd_lastfile == -1); |
| 1291 | KASSERT(fdp->fd_lastkqfile == -1); |
| 1292 | KASSERT(fdp->fd_knhash == NULL); |
| 1293 | KASSERT(fdp->fd_freefile == 0); |
| 1294 | KASSERT(fdp->fd_exclose == false); |
| 1295 | KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); |
| 1296 | KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); |
| 1297 | for (fd = 0; fd < NDFDFILE; fd++) { |
| 1298 | KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == |
| 1299 | (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 1300 | } |
| 1301 | for (fd = NDFDFILE; fd < NDFILE; fd++) { |
| 1302 | KASSERT(fdp->fd_dtbuiltin.dt_ff[fd] == NULL); |
| 1303 | } |
| 1304 | KASSERT(fdp->fd_himap == fdp->fd_dhimap); |
| 1305 | KASSERT(fdp->fd_lomap == fdp->fd_dlomap); |
| 1306 | #endif /* DIAGNOSTIC */ |
| 1307 | |
| 1308 | fdp->fd_refcnt = 1; |
| 1309 | fd_checkmaps(fdp); |
| 1310 | |
| 1311 | return fdp; |
| 1312 | } |
| 1313 | |
| 1314 | /* |
| 1315 | * Initialize a file descriptor table. |
| 1316 | */ |
| 1317 | static int |
| 1318 | filedesc_ctor(void *arg, void *obj, int flag) |
| 1319 | { |
| 1320 | filedesc_t *fdp = obj; |
| 1321 | fdfile_t **ffp; |
| 1322 | int i; |
| 1323 | |
| 1324 | memset(fdp, 0, sizeof(*fdp)); |
| 1325 | mutex_init(&fdp->fd_lock, MUTEX_DEFAULT, IPL_NONE); |
| 1326 | fdp->fd_lastfile = -1; |
| 1327 | fdp->fd_lastkqfile = -1; |
| 1328 | fdp->fd_dt = &fdp->fd_dtbuiltin; |
| 1329 | fdp->fd_dtbuiltin.dt_nfiles = NDFILE; |
| 1330 | fdp->fd_himap = fdp->fd_dhimap; |
| 1331 | fdp->fd_lomap = fdp->fd_dlomap; |
| 1332 | |
| 1333 | CTASSERT(sizeof(fdp->fd_dfdfile[0]) >= sizeof(fdfile_t)); |
| 1334 | for (i = 0, ffp = fdp->fd_dt->dt_ff; i < NDFDFILE; i++, ffp++) { |
| 1335 | *ffp = (fdfile_t *)fdp->fd_dfdfile[i]; |
| 1336 | (void)fdfile_ctor(NULL, fdp->fd_dfdfile[i], PR_WAITOK); |
| 1337 | } |
| 1338 | |
| 1339 | return 0; |
| 1340 | } |
| 1341 | |
| 1342 | static void |
| 1343 | filedesc_dtor(void *arg, void *obj) |
| 1344 | { |
| 1345 | filedesc_t *fdp = obj; |
| 1346 | int i; |
| 1347 | |
| 1348 | for (i = 0; i < NDFDFILE; i++) { |
| 1349 | fdfile_dtor(NULL, fdp->fd_dfdfile[i]); |
| 1350 | } |
| 1351 | |
| 1352 | mutex_destroy(&fdp->fd_lock); |
| 1353 | } |
| 1354 | |
| 1355 | /* |
| 1356 | * Make p share curproc's filedesc structure. |
| 1357 | */ |
| 1358 | void |
| 1359 | fd_share(struct proc *p) |
| 1360 | { |
| 1361 | filedesc_t *fdp; |
| 1362 | |
| 1363 | fdp = curlwp->l_fd; |
| 1364 | p->p_fd = fdp; |
| 1365 | atomic_inc_uint(&fdp->fd_refcnt); |
| 1366 | } |
| 1367 | |
| 1368 | /* |
| 1369 | * Acquire a hold on a filedesc structure. |
| 1370 | */ |
| 1371 | void |
| 1372 | fd_hold(lwp_t *l) |
| 1373 | { |
| 1374 | filedesc_t *fdp = l->l_fd; |
| 1375 | |
| 1376 | atomic_inc_uint(&fdp->fd_refcnt); |
| 1377 | } |
| 1378 | |
| 1379 | /* |
| 1380 | * Copy a filedesc structure. |
| 1381 | */ |
| 1382 | filedesc_t * |
| 1383 | fd_copy(void) |
| 1384 | { |
| 1385 | filedesc_t *newfdp, *fdp; |
| 1386 | fdfile_t *ff, **ffp, **nffp, *ff2; |
| 1387 | int i, j, numfiles, lastfile, newlast; |
| 1388 | file_t *fp; |
| 1389 | fdtab_t *newdt; |
| 1390 | |
| 1391 | fdp = curproc->p_fd; |
| 1392 | newfdp = pool_cache_get(filedesc_cache, PR_WAITOK); |
| 1393 | newfdp->fd_refcnt = 1; |
| 1394 | |
| 1395 | #ifdef DIAGNOSTIC |
| 1396 | KASSERT(newfdp->fd_lastfile == -1); |
| 1397 | KASSERT(newfdp->fd_lastkqfile == -1); |
| 1398 | KASSERT(newfdp->fd_knhash == NULL); |
| 1399 | KASSERT(newfdp->fd_freefile == 0); |
| 1400 | KASSERT(newfdp->fd_exclose == false); |
| 1401 | KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); |
| 1402 | KASSERT(newfdp->fd_dtbuiltin.dt_nfiles == NDFILE); |
| 1403 | for (i = 0; i < NDFDFILE; i++) { |
| 1404 | KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == |
| 1405 | (fdfile_t *)&newfdp->fd_dfdfile[i]); |
| 1406 | } |
| 1407 | for (i = NDFDFILE; i < NDFILE; i++) { |
| 1408 | KASSERT(newfdp->fd_dtbuiltin.dt_ff[i] == NULL); |
| 1409 | } |
| 1410 | #endif /* DIAGNOSTIC */ |
| 1411 | |
| 1412 | mutex_enter(&fdp->fd_lock); |
| 1413 | fd_checkmaps(fdp); |
| 1414 | numfiles = fdp->fd_dt->dt_nfiles; |
| 1415 | lastfile = fdp->fd_lastfile; |
| 1416 | |
| 1417 | /* |
| 1418 | * If the number of open files fits in the internal arrays |
| 1419 | * of the open file structure, use them, otherwise allocate |
| 1420 | * additional memory for the number of descriptors currently |
| 1421 | * in use. |
| 1422 | */ |
| 1423 | if (lastfile < NDFILE) { |
| 1424 | i = NDFILE; |
| 1425 | newdt = newfdp->fd_dt; |
| 1426 | KASSERT(newfdp->fd_dt == &newfdp->fd_dtbuiltin); |
| 1427 | } else { |
| 1428 | /* |
| 1429 | * Compute the smallest multiple of NDEXTENT needed |
| 1430 | * for the file descriptors currently in use, |
| 1431 | * allowing the table to shrink. |
| 1432 | */ |
| 1433 | i = numfiles; |
| 1434 | while (i >= 2 * NDEXTENT && i > lastfile * 2) { |
| 1435 | i /= 2; |
| 1436 | } |
| 1437 | KASSERT(i > NDFILE); |
| 1438 | newdt = fd_dtab_alloc(i); |
| 1439 | newfdp->fd_dt = newdt; |
| 1440 | memcpy(newdt->dt_ff, newfdp->fd_dtbuiltin.dt_ff, |
| 1441 | NDFDFILE * sizeof(fdfile_t **)); |
| 1442 | memset(newdt->dt_ff + NDFDFILE, 0, |
| 1443 | (i - NDFDFILE) * sizeof(fdfile_t **)); |
| 1444 | } |
| 1445 | if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { |
| 1446 | newfdp->fd_himap = newfdp->fd_dhimap; |
| 1447 | newfdp->fd_lomap = newfdp->fd_dlomap; |
| 1448 | } else { |
| 1449 | fd_map_alloc(i, &newfdp->fd_lomap, &newfdp->fd_himap); |
| 1450 | KASSERT(i >= NDENTRIES * NDENTRIES); |
| 1451 | memset(newfdp->fd_himap, 0, NDHISLOTS(i)*sizeof(uint32_t)); |
| 1452 | memset(newfdp->fd_lomap, 0, NDLOSLOTS(i)*sizeof(uint32_t)); |
| 1453 | } |
| 1454 | newfdp->fd_freefile = fdp->fd_freefile; |
| 1455 | newfdp->fd_exclose = fdp->fd_exclose; |
| 1456 | |
| 1457 | ffp = fdp->fd_dt->dt_ff; |
| 1458 | nffp = newdt->dt_ff; |
| 1459 | newlast = -1; |
| 1460 | for (i = 0; i <= lastfile; i++, ffp++, nffp++) { |
| 1461 | KASSERT(i >= NDFDFILE || |
| 1462 | *nffp == (fdfile_t *)newfdp->fd_dfdfile[i]); |
| 1463 | ff = *ffp; |
| 1464 | if (ff == NULL || (fp = ff->ff_file) == NULL) { |
| 1465 | /* Descriptor unused, or descriptor half open. */ |
| 1466 | KASSERT(!fd_isused(newfdp, i)); |
| 1467 | continue; |
| 1468 | } |
| 1469 | if (__predict_false(fp->f_type == DTYPE_KQUEUE)) { |
| 1470 | /* kqueue descriptors cannot be copied. */ |
| 1471 | if (i < newfdp->fd_freefile) { |
| 1472 | newfdp->fd_freefile = i; |
| 1473 | } |
| 1474 | continue; |
| 1475 | } |
| 1476 | /* It's active: add a reference to the file. */ |
| 1477 | mutex_enter(&fp->f_lock); |
| 1478 | fp->f_count++; |
| 1479 | mutex_exit(&fp->f_lock); |
| 1480 | |
| 1481 | /* Allocate an fdfile_t to represent it. */ |
| 1482 | if (i >= NDFDFILE) { |
| 1483 | ff2 = pool_cache_get(fdfile_cache, PR_WAITOK); |
| 1484 | *nffp = ff2; |
| 1485 | } else { |
| 1486 | ff2 = newdt->dt_ff[i]; |
| 1487 | } |
| 1488 | ff2->ff_file = fp; |
| 1489 | ff2->ff_exclose = ff->ff_exclose; |
| 1490 | ff2->ff_allocated = true; |
| 1491 | |
| 1492 | /* Fix up bitmaps. */ |
| 1493 | j = i >> NDENTRYSHIFT; |
| 1494 | KASSERT((newfdp->fd_lomap[j] & (1 << (i & NDENTRYMASK))) == 0); |
| 1495 | newfdp->fd_lomap[j] |= 1 << (i & NDENTRYMASK); |
| 1496 | if (__predict_false(newfdp->fd_lomap[j] == ~0)) { |
| 1497 | KASSERT((newfdp->fd_himap[j >> NDENTRYSHIFT] & |
| 1498 | (1 << (j & NDENTRYMASK))) == 0); |
| 1499 | newfdp->fd_himap[j >> NDENTRYSHIFT] |= |
| 1500 | 1 << (j & NDENTRYMASK); |
| 1501 | } |
| 1502 | newlast = i; |
| 1503 | } |
| 1504 | KASSERT(newdt->dt_ff[0] == (fdfile_t *)newfdp->fd_dfdfile[0]); |
| 1505 | newfdp->fd_lastfile = newlast; |
| 1506 | fd_checkmaps(newfdp); |
| 1507 | mutex_exit(&fdp->fd_lock); |
| 1508 | |
| 1509 | return newfdp; |
| 1510 | } |
| 1511 | |
| 1512 | /* |
| 1513 | * Release a filedesc structure. |
| 1514 | */ |
| 1515 | void |
| 1516 | fd_free(void) |
| 1517 | { |
| 1518 | fdfile_t *ff; |
| 1519 | file_t *fp; |
| 1520 | int fd, nf; |
| 1521 | fdtab_t *dt; |
| 1522 | lwp_t * const l = curlwp; |
| 1523 | filedesc_t * const fdp = l->l_fd; |
| 1524 | const bool noadvlock = (l->l_proc->p_flag & PK_ADVLOCK) == 0; |
| 1525 | |
| 1526 | KASSERT(fdp->fd_dt->dt_ff[0] == (fdfile_t *)fdp->fd_dfdfile[0]); |
| 1527 | KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); |
| 1528 | KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); |
| 1529 | |
| 1530 | #ifndef __HAVE_ATOMIC_AS_MEMBAR |
| 1531 | membar_exit(); |
| 1532 | #endif |
| 1533 | if (atomic_dec_uint_nv(&fdp->fd_refcnt) > 0) |
| 1534 | return; |
| 1535 | |
| 1536 | /* |
| 1537 | * Close any files that the process holds open. |
| 1538 | */ |
| 1539 | dt = fdp->fd_dt; |
| 1540 | fd_checkmaps(fdp); |
| 1541 | #ifdef DEBUG |
| 1542 | fdp->fd_refcnt = -1; /* see fd_checkmaps */ |
| 1543 | #endif |
| 1544 | for (fd = 0, nf = dt->dt_nfiles; fd < nf; fd++) { |
| 1545 | ff = dt->dt_ff[fd]; |
| 1546 | KASSERT(fd >= NDFDFILE || |
| 1547 | ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 1548 | if (ff == NULL) |
| 1549 | continue; |
| 1550 | if ((fp = ff->ff_file) != NULL) { |
| 1551 | /* |
| 1552 | * Must use fd_close() here if there is |
| 1553 | * a reference from kqueue or we might have posix |
| 1554 | * advisory locks. |
| 1555 | */ |
| 1556 | if (__predict_true(ff->ff_refcnt == 0) && |
| 1557 | (noadvlock || fp->f_type != DTYPE_VNODE)) { |
| 1558 | ff->ff_file = NULL; |
| 1559 | ff->ff_exclose = false; |
| 1560 | ff->ff_allocated = false; |
| 1561 | closef(fp); |
| 1562 | } else { |
| 1563 | ff->ff_refcnt++; |
| 1564 | fd_close(fd); |
| 1565 | } |
| 1566 | } |
| 1567 | KASSERT(ff->ff_refcnt == 0); |
| 1568 | KASSERT(ff->ff_file == NULL); |
| 1569 | KASSERT(!ff->ff_exclose); |
| 1570 | KASSERT(!ff->ff_allocated); |
| 1571 | if (fd >= NDFDFILE) { |
| 1572 | pool_cache_put(fdfile_cache, ff); |
| 1573 | dt->dt_ff[fd] = NULL; |
| 1574 | } |
| 1575 | } |
| 1576 | |
| 1577 | /* |
| 1578 | * Clean out the descriptor table for the next user and return |
| 1579 | * to the cache. |
| 1580 | */ |
| 1581 | if (__predict_false(dt != &fdp->fd_dtbuiltin)) { |
| 1582 | fd_dtab_free(fdp->fd_dt); |
| 1583 | /* Otherwise, done above. */ |
| 1584 | memset(&fdp->fd_dtbuiltin.dt_ff[NDFDFILE], 0, |
| 1585 | (NDFILE - NDFDFILE) * sizeof(fdp->fd_dtbuiltin.dt_ff[0])); |
| 1586 | fdp->fd_dt = &fdp->fd_dtbuiltin; |
| 1587 | } |
| 1588 | if (__predict_false(NDHISLOTS(nf) > NDHISLOTS(NDFILE))) { |
| 1589 | KASSERT(fdp->fd_himap != fdp->fd_dhimap); |
| 1590 | KASSERT(fdp->fd_lomap != fdp->fd_dlomap); |
| 1591 | fd_map_free(nf, fdp->fd_lomap, fdp->fd_himap); |
| 1592 | } |
| 1593 | if (__predict_false(fdp->fd_knhash != NULL)) { |
| 1594 | hashdone(fdp->fd_knhash, HASH_LIST, fdp->fd_knhashmask); |
| 1595 | fdp->fd_knhash = NULL; |
| 1596 | fdp->fd_knhashmask = 0; |
| 1597 | } else { |
| 1598 | KASSERT(fdp->fd_knhashmask == 0); |
| 1599 | } |
| 1600 | fdp->fd_dt = &fdp->fd_dtbuiltin; |
| 1601 | fdp->fd_lastkqfile = -1; |
| 1602 | fdp->fd_lastfile = -1; |
| 1603 | fdp->fd_freefile = 0; |
| 1604 | fdp->fd_exclose = false; |
| 1605 | memset(&fdp->fd_startzero, 0, sizeof(*fdp) - |
| 1606 | offsetof(filedesc_t, fd_startzero)); |
| 1607 | fdp->fd_himap = fdp->fd_dhimap; |
| 1608 | fdp->fd_lomap = fdp->fd_dlomap; |
| 1609 | KASSERT(fdp->fd_dtbuiltin.dt_nfiles == NDFILE); |
| 1610 | KASSERT(fdp->fd_dtbuiltin.dt_link == NULL); |
| 1611 | KASSERT(fdp->fd_dt == &fdp->fd_dtbuiltin); |
| 1612 | #ifdef DEBUG |
| 1613 | fdp->fd_refcnt = 0; /* see fd_checkmaps */ |
| 1614 | #endif |
| 1615 | fd_checkmaps(fdp); |
| 1616 | pool_cache_put(filedesc_cache, fdp); |
| 1617 | } |
| 1618 | |
| 1619 | /* |
| 1620 | * File Descriptor pseudo-device driver (/dev/fd/). |
| 1621 | * |
| 1622 | * Opening minor device N dup()s the file (if any) connected to file |
| 1623 | * descriptor N belonging to the calling process. Note that this driver |
| 1624 | * consists of only the ``open()'' routine, because all subsequent |
| 1625 | * references to this file will be direct to the other driver. |
| 1626 | */ |
| 1627 | static int |
| 1628 | filedescopen(dev_t dev, int mode, int type, lwp_t *l) |
| 1629 | { |
| 1630 | |
| 1631 | /* |
| 1632 | * XXX Kludge: set dupfd to contain the value of the |
| 1633 | * the file descriptor being sought for duplication. The error |
| 1634 | * return ensures that the vnode for this device will be released |
| 1635 | * by vn_open. Open will detect this special error and take the |
| 1636 | * actions in fd_dupopen below. Other callers of vn_open or VOP_OPEN |
| 1637 | * will simply report the error. |
| 1638 | */ |
| 1639 | l->l_dupfd = minor(dev); /* XXX */ |
| 1640 | return EDUPFD; |
| 1641 | } |
| 1642 | |
| 1643 | /* |
| 1644 | * Duplicate the specified descriptor to a free descriptor. |
| 1645 | */ |
| 1646 | int |
| 1647 | fd_dupopen(int old, int *newp, int mode, int error) |
| 1648 | { |
| 1649 | filedesc_t *fdp; |
| 1650 | fdfile_t *ff; |
| 1651 | file_t *fp; |
| 1652 | fdtab_t *dt; |
| 1653 | |
| 1654 | if ((fp = fd_getfile(old)) == NULL) { |
| 1655 | return EBADF; |
| 1656 | } |
| 1657 | fdp = curlwp->l_fd; |
| 1658 | dt = fdp->fd_dt; |
| 1659 | ff = dt->dt_ff[old]; |
| 1660 | |
| 1661 | /* |
| 1662 | * There are two cases of interest here. |
| 1663 | * |
| 1664 | * For EDUPFD simply dup (old) to file descriptor |
| 1665 | * (new) and return. |
| 1666 | * |
| 1667 | * For EMOVEFD steal away the file structure from (old) and |
| 1668 | * store it in (new). (old) is effectively closed by |
| 1669 | * this operation. |
| 1670 | * |
| 1671 | * Any other error code is just returned. |
| 1672 | */ |
| 1673 | switch (error) { |
| 1674 | case EDUPFD: |
| 1675 | /* |
| 1676 | * Check that the mode the file is being opened for is a |
| 1677 | * subset of the mode of the existing descriptor. |
| 1678 | */ |
| 1679 | if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { |
| 1680 | error = EACCES; |
| 1681 | break; |
| 1682 | } |
| 1683 | |
| 1684 | /* Copy it. */ |
| 1685 | error = fd_dup(fp, 0, newp, ff->ff_exclose); |
| 1686 | break; |
| 1687 | |
| 1688 | case EMOVEFD: |
| 1689 | /* Copy it. */ |
| 1690 | error = fd_dup(fp, 0, newp, ff->ff_exclose); |
| 1691 | if (error != 0) { |
| 1692 | break; |
| 1693 | } |
| 1694 | |
| 1695 | /* Steal away the file pointer from 'old'. */ |
| 1696 | (void)fd_close(old); |
| 1697 | return 0; |
| 1698 | } |
| 1699 | |
| 1700 | fd_putfile(old); |
| 1701 | return error; |
| 1702 | } |
| 1703 | |
| 1704 | /* |
| 1705 | * Close open files on exec. |
| 1706 | */ |
| 1707 | void |
| 1708 | fd_closeexec(void) |
| 1709 | { |
| 1710 | proc_t *p; |
| 1711 | filedesc_t *fdp; |
| 1712 | fdfile_t *ff; |
| 1713 | lwp_t *l; |
| 1714 | fdtab_t *dt; |
| 1715 | int fd; |
| 1716 | |
| 1717 | l = curlwp; |
| 1718 | p = l->l_proc; |
| 1719 | fdp = p->p_fd; |
| 1720 | |
| 1721 | if (fdp->fd_refcnt > 1) { |
| 1722 | fdp = fd_copy(); |
| 1723 | fd_free(); |
| 1724 | p->p_fd = fdp; |
| 1725 | l->l_fd = fdp; |
| 1726 | } |
| 1727 | if (!fdp->fd_exclose) { |
| 1728 | return; |
| 1729 | } |
| 1730 | fdp->fd_exclose = false; |
| 1731 | dt = fdp->fd_dt; |
| 1732 | |
| 1733 | for (fd = 0; fd <= fdp->fd_lastfile; fd++) { |
| 1734 | if ((ff = dt->dt_ff[fd]) == NULL) { |
| 1735 | KASSERT(fd >= NDFDFILE); |
| 1736 | continue; |
| 1737 | } |
| 1738 | KASSERT(fd >= NDFDFILE || |
| 1739 | ff == (fdfile_t *)fdp->fd_dfdfile[fd]); |
| 1740 | if (ff->ff_file == NULL) |
| 1741 | continue; |
| 1742 | if (ff->ff_exclose) { |
| 1743 | /* |
| 1744 | * We need a reference to close the file. |
| 1745 | * No other threads can see the fdfile_t at |
| 1746 | * this point, so don't bother locking. |
| 1747 | */ |
| 1748 | KASSERT((ff->ff_refcnt & FR_CLOSING) == 0); |
| 1749 | ff->ff_refcnt++; |
| 1750 | fd_close(fd); |
| 1751 | } |
| 1752 | } |
| 1753 | } |
| 1754 | |
| 1755 | /* |
| 1756 | * Sets descriptor owner. If the owner is a process, 'pgid' |
| 1757 | * is set to positive value, process ID. If the owner is process group, |
| 1758 | * 'pgid' is set to -pg_id. |
| 1759 | */ |
| 1760 | int |
| 1761 | fsetown(pid_t *pgid, u_long cmd, const void *data) |
| 1762 | { |
| 1763 | pid_t id = *(const pid_t *)data; |
| 1764 | int error; |
| 1765 | |
| 1766 | switch (cmd) { |
| 1767 | case TIOCSPGRP: |
| 1768 | if (id < 0) |
| 1769 | return EINVAL; |
| 1770 | id = -id; |
| 1771 | break; |
| 1772 | default: |
| 1773 | break; |
| 1774 | } |
| 1775 | if (id > 0) { |
| 1776 | mutex_enter(proc_lock); |
| 1777 | error = proc_find(id) ? 0 : ESRCH; |
| 1778 | mutex_exit(proc_lock); |
| 1779 | } else if (id < 0) { |
| 1780 | error = pgid_in_session(curproc, -id); |
| 1781 | } else { |
| 1782 | error = 0; |
| 1783 | } |
| 1784 | if (!error) { |
| 1785 | *pgid = id; |
| 1786 | } |
| 1787 | return error; |
| 1788 | } |
| 1789 | |
| 1790 | void |
| 1791 | fd_set_exclose(struct lwp *l, int fd, bool exclose) |
| 1792 | { |
| 1793 | filedesc_t *fdp = l->l_fd; |
| 1794 | fdfile_t *ff = fdp->fd_dt->dt_ff[fd]; |
| 1795 | |
| 1796 | ff->ff_exclose = exclose; |
| 1797 | if (exclose) |
| 1798 | fdp->fd_exclose = true; |
| 1799 | } |
| 1800 | |
| 1801 | /* |
| 1802 | * Return descriptor owner information. If the value is positive, |
| 1803 | * it's process ID. If it's negative, it's process group ID and |
| 1804 | * needs the sign removed before use. |
| 1805 | */ |
| 1806 | int |
| 1807 | fgetown(pid_t pgid, u_long cmd, void *data) |
| 1808 | { |
| 1809 | |
| 1810 | switch (cmd) { |
| 1811 | case TIOCGPGRP: |
| 1812 | *(int *)data = -pgid; |
| 1813 | break; |
| 1814 | default: |
| 1815 | *(int *)data = pgid; |
| 1816 | break; |
| 1817 | } |
| 1818 | return 0; |
| 1819 | } |
| 1820 | |
| 1821 | /* |
| 1822 | * Send signal to descriptor owner, either process or process group. |
| 1823 | */ |
| 1824 | void |
| 1825 | fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) |
| 1826 | { |
| 1827 | ksiginfo_t ksi; |
| 1828 | |
| 1829 | KASSERT(!cpu_intr_p()); |
| 1830 | |
| 1831 | if (pgid == 0) { |
| 1832 | return; |
| 1833 | } |
| 1834 | |
| 1835 | KSI_INIT(&ksi); |
| 1836 | ksi.ksi_signo = signo; |
| 1837 | ksi.ksi_code = code; |
| 1838 | ksi.ksi_band = band; |
| 1839 | |
| 1840 | mutex_enter(proc_lock); |
| 1841 | if (pgid > 0) { |
| 1842 | struct proc *p1; |
| 1843 | |
| 1844 | p1 = proc_find(pgid); |
| 1845 | if (p1 != NULL) { |
| 1846 | kpsignal(p1, &ksi, fdescdata); |
| 1847 | } |
| 1848 | } else { |
| 1849 | struct pgrp *pgrp; |
| 1850 | |
| 1851 | KASSERT(pgid < 0); |
| 1852 | pgrp = pgrp_find(-pgid); |
| 1853 | if (pgrp != NULL) { |
| 1854 | kpgsignal(pgrp, &ksi, fdescdata, 0); |
| 1855 | } |
| 1856 | } |
| 1857 | mutex_exit(proc_lock); |
| 1858 | } |
| 1859 | |
| 1860 | int |
| 1861 | fd_clone(file_t *fp, unsigned fd, int flag, const struct fileops *fops, |
| 1862 | void *data) |
| 1863 | { |
| 1864 | fdfile_t *ff; |
| 1865 | filedesc_t *fdp; |
| 1866 | |
| 1867 | fp->f_flag |= flag & FMASK; |
| 1868 | fdp = curproc->p_fd; |
| 1869 | ff = fdp->fd_dt->dt_ff[fd]; |
| 1870 | KASSERT(ff != NULL); |
| 1871 | ff->ff_exclose = (flag & O_CLOEXEC) != 0; |
| 1872 | fp->f_type = DTYPE_MISC; |
| 1873 | fp->f_ops = fops; |
| 1874 | fp->f_data = data; |
| 1875 | curlwp->l_dupfd = fd; |
| 1876 | fd_affix(curproc, fp, fd); |
| 1877 | |
| 1878 | return EMOVEFD; |
| 1879 | } |
| 1880 | |
| 1881 | int |
| 1882 | fnullop_fcntl(file_t *fp, u_int cmd, void *data) |
| 1883 | { |
| 1884 | |
| 1885 | if (cmd == F_SETFL) |
| 1886 | return 0; |
| 1887 | |
| 1888 | return EOPNOTSUPP; |
| 1889 | } |
| 1890 | |
| 1891 | int |
| 1892 | fnullop_poll(file_t *fp, int which) |
| 1893 | { |
| 1894 | |
| 1895 | return 0; |
| 1896 | } |
| 1897 | |
| 1898 | int |
| 1899 | fnullop_kqfilter(file_t *fp, struct knote *kn) |
| 1900 | { |
| 1901 | |
| 1902 | return EOPNOTSUPP; |
| 1903 | } |
| 1904 | |
| 1905 | void |
| 1906 | fnullop_restart(file_t *fp) |
| 1907 | { |
| 1908 | |
| 1909 | } |
| 1910 | |
| 1911 | int |
| 1912 | fbadop_read(file_t *fp, off_t *offset, struct uio *uio, |
| 1913 | kauth_cred_t cred, int flags) |
| 1914 | { |
| 1915 | |
| 1916 | return EOPNOTSUPP; |
| 1917 | } |
| 1918 | |
| 1919 | int |
| 1920 | fbadop_write(file_t *fp, off_t *offset, struct uio *uio, |
| 1921 | kauth_cred_t cred, int flags) |
| 1922 | { |
| 1923 | |
| 1924 | return EOPNOTSUPP; |
| 1925 | } |
| 1926 | |
| 1927 | int |
| 1928 | fbadop_ioctl(file_t *fp, u_long com, void *data) |
| 1929 | { |
| 1930 | |
| 1931 | return EOPNOTSUPP; |
| 1932 | } |
| 1933 | |
| 1934 | int |
| 1935 | fbadop_stat(file_t *fp, struct stat *sb) |
| 1936 | { |
| 1937 | |
| 1938 | return EOPNOTSUPP; |
| 1939 | } |
| 1940 | |
| 1941 | int |
| 1942 | fbadop_close(file_t *fp) |
| 1943 | { |
| 1944 | |
| 1945 | return EOPNOTSUPP; |
| 1946 | } |
| 1947 | |
| 1948 | /* |
| 1949 | * sysctl routines pertaining to file descriptors |
| 1950 | */ |
| 1951 | |
| 1952 | /* Initialized in sysctl_init() for now... */ |
| 1953 | extern kmutex_t sysctl_file_marker_lock; |
| 1954 | static u_int sysctl_file_marker = 1; |
| 1955 | |
| 1956 | /* |
| 1957 | * Expects to be called with proc_lock and sysctl_file_marker_lock locked. |
| 1958 | */ |
| 1959 | static void |
| 1960 | sysctl_file_marker_reset(void) |
| 1961 | { |
| 1962 | struct proc *p; |
| 1963 | |
| 1964 | PROCLIST_FOREACH(p, &allproc) { |
| 1965 | struct filedesc *fd = p->p_fd; |
| 1966 | fdtab_t *dt; |
| 1967 | u_int i; |
| 1968 | |
| 1969 | mutex_enter(&fd->fd_lock); |
| 1970 | dt = fd->fd_dt; |
| 1971 | for (i = 0; i < dt->dt_nfiles; i++) { |
| 1972 | struct file *fp; |
| 1973 | fdfile_t *ff; |
| 1974 | |
| 1975 | if ((ff = dt->dt_ff[i]) == NULL) { |
| 1976 | continue; |
| 1977 | } |
| 1978 | if ((fp = ff->ff_file) == NULL) { |
| 1979 | continue; |
| 1980 | } |
| 1981 | fp->f_marker = 0; |
| 1982 | } |
| 1983 | mutex_exit(&fd->fd_lock); |
| 1984 | } |
| 1985 | } |
| 1986 | |
| 1987 | /* |
| 1988 | * sysctl helper routine for kern.file pseudo-subtree. |
| 1989 | */ |
| 1990 | static int |
| 1991 | sysctl_kern_file(SYSCTLFN_ARGS) |
| 1992 | { |
| 1993 | int error; |
| 1994 | size_t buflen; |
| 1995 | struct file *fp, fbuf; |
| 1996 | char *start, *where; |
| 1997 | struct proc *p; |
| 1998 | |
| 1999 | start = where = oldp; |
| 2000 | buflen = *oldlenp; |
| 2001 | |
| 2002 | if (where == NULL) { |
| 2003 | /* |
| 2004 | * overestimate by 10 files |
| 2005 | */ |
| 2006 | *oldlenp = sizeof(filehead) + (nfiles + 10) * |
| 2007 | sizeof(struct file); |
| 2008 | return 0; |
| 2009 | } |
| 2010 | |
| 2011 | /* |
| 2012 | * first sysctl_copyout filehead |
| 2013 | */ |
| 2014 | if (buflen < sizeof(filehead)) { |
| 2015 | *oldlenp = 0; |
| 2016 | return 0; |
| 2017 | } |
| 2018 | sysctl_unlock(); |
| 2019 | error = sysctl_copyout(l, &filehead, where, sizeof(filehead)); |
| 2020 | if (error) { |
| 2021 | sysctl_relock(); |
| 2022 | return error; |
| 2023 | } |
| 2024 | buflen -= sizeof(filehead); |
| 2025 | where += sizeof(filehead); |
| 2026 | |
| 2027 | /* |
| 2028 | * followed by an array of file structures |
| 2029 | */ |
| 2030 | mutex_enter(&sysctl_file_marker_lock); |
| 2031 | mutex_enter(proc_lock); |
| 2032 | PROCLIST_FOREACH(p, &allproc) { |
| 2033 | struct filedesc *fd; |
| 2034 | fdtab_t *dt; |
| 2035 | u_int i; |
| 2036 | |
| 2037 | if (p->p_stat == SIDL) { |
| 2038 | /* skip embryonic processes */ |
| 2039 | continue; |
| 2040 | } |
| 2041 | mutex_enter(p->p_lock); |
| 2042 | error = kauth_authorize_process(l->l_cred, |
| 2043 | KAUTH_PROCESS_CANSEE, p, |
| 2044 | KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), |
| 2045 | NULL, NULL); |
| 2046 | mutex_exit(p->p_lock); |
| 2047 | if (error != 0) { |
| 2048 | /* |
| 2049 | * Don't leak kauth retval if we're silently |
| 2050 | * skipping this entry. |
| 2051 | */ |
| 2052 | error = 0; |
| 2053 | continue; |
| 2054 | } |
| 2055 | |
| 2056 | /* |
| 2057 | * Grab a hold on the process. |
| 2058 | */ |
| 2059 | if (!rw_tryenter(&p->p_reflock, RW_READER)) { |
| 2060 | continue; |
| 2061 | } |
| 2062 | mutex_exit(proc_lock); |
| 2063 | |
| 2064 | fd = p->p_fd; |
| 2065 | mutex_enter(&fd->fd_lock); |
| 2066 | dt = fd->fd_dt; |
| 2067 | for (i = 0; i < dt->dt_nfiles; i++) { |
| 2068 | fdfile_t *ff; |
| 2069 | |
| 2070 | if ((ff = dt->dt_ff[i]) == NULL) { |
| 2071 | continue; |
| 2072 | } |
| 2073 | if ((fp = ff->ff_file) == NULL) { |
| 2074 | continue; |
| 2075 | } |
| 2076 | |
| 2077 | mutex_enter(&fp->f_lock); |
| 2078 | |
| 2079 | if ((fp->f_count == 0) || |
| 2080 | (fp->f_marker == sysctl_file_marker)) { |
| 2081 | mutex_exit(&fp->f_lock); |
| 2082 | continue; |
| 2083 | } |
| 2084 | |
| 2085 | /* Check that we have enough space. */ |
| 2086 | if (buflen < sizeof(struct file)) { |
| 2087 | *oldlenp = where - start; |
| 2088 | mutex_exit(&fp->f_lock); |
| 2089 | error = ENOMEM; |
| 2090 | break; |
| 2091 | } |
| 2092 | |
| 2093 | memcpy(&fbuf, fp, sizeof(fbuf)); |
| 2094 | mutex_exit(&fp->f_lock); |
| 2095 | error = sysctl_copyout(l, &fbuf, where, sizeof(fbuf)); |
| 2096 | if (error) { |
| 2097 | break; |
| 2098 | } |
| 2099 | buflen -= sizeof(struct file); |
| 2100 | where += sizeof(struct file); |
| 2101 | |
| 2102 | fp->f_marker = sysctl_file_marker; |
| 2103 | } |
| 2104 | mutex_exit(&fd->fd_lock); |
| 2105 | |
| 2106 | /* |
| 2107 | * Release reference to process. |
| 2108 | */ |
| 2109 | mutex_enter(proc_lock); |
| 2110 | rw_exit(&p->p_reflock); |
| 2111 | |
| 2112 | if (error) |
| 2113 | break; |
| 2114 | } |
| 2115 | |
| 2116 | sysctl_file_marker++; |
| 2117 | /* Reset all markers if wrapped. */ |
| 2118 | if (sysctl_file_marker == 0) { |
| 2119 | sysctl_file_marker_reset(); |
| 2120 | sysctl_file_marker++; |
| 2121 | } |
| 2122 | |
| 2123 | mutex_exit(proc_lock); |
| 2124 | mutex_exit(&sysctl_file_marker_lock); |
| 2125 | |
| 2126 | *oldlenp = where - start; |
| 2127 | sysctl_relock(); |
| 2128 | return error; |
| 2129 | } |
| 2130 | |
| 2131 | /* |
| 2132 | * sysctl helper function for kern.file2 |
| 2133 | */ |
| 2134 | static int |
| 2135 | sysctl_kern_file2(SYSCTLFN_ARGS) |
| 2136 | { |
| 2137 | struct proc *p; |
| 2138 | struct file *fp; |
| 2139 | struct filedesc *fd; |
| 2140 | struct kinfo_file kf; |
| 2141 | char *dp; |
| 2142 | u_int i, op; |
| 2143 | size_t len, needed, elem_size, out_size; |
| 2144 | int error, arg, elem_count; |
| 2145 | fdfile_t *ff; |
| 2146 | fdtab_t *dt; |
| 2147 | |
| 2148 | if (namelen == 1 && name[0] == CTL_QUERY) |
| 2149 | return sysctl_query(SYSCTLFN_CALL(rnode)); |
| 2150 | |
| 2151 | if (namelen != 4) |
| 2152 | return EINVAL; |
| 2153 | |
| 2154 | error = 0; |
| 2155 | dp = oldp; |
| 2156 | len = (oldp != NULL) ? *oldlenp : 0; |
| 2157 | op = name[0]; |
| 2158 | arg = name[1]; |
| 2159 | elem_size = name[2]; |
| 2160 | elem_count = name[3]; |
| 2161 | out_size = MIN(sizeof(kf), elem_size); |
| 2162 | needed = 0; |
| 2163 | |
| 2164 | if (elem_size < 1 || elem_count < 0) |
| 2165 | return EINVAL; |
| 2166 | |
| 2167 | switch (op) { |
| 2168 | case KERN_FILE_BYFILE: |
| 2169 | case KERN_FILE_BYPID: |
| 2170 | /* |
| 2171 | * We're traversing the process list in both cases; the BYFILE |
| 2172 | * case does additional work of keeping track of files already |
| 2173 | * looked at. |
| 2174 | */ |
| 2175 | |
| 2176 | /* doesn't use arg so it must be zero */ |
| 2177 | if ((op == KERN_FILE_BYFILE) && (arg != 0)) |
| 2178 | return EINVAL; |
| 2179 | |
| 2180 | if ((op == KERN_FILE_BYPID) && (arg < -1)) |
| 2181 | /* -1 means all processes */ |
| 2182 | return EINVAL; |
| 2183 | |
| 2184 | sysctl_unlock(); |
| 2185 | if (op == KERN_FILE_BYFILE) |
| 2186 | mutex_enter(&sysctl_file_marker_lock); |
| 2187 | mutex_enter(proc_lock); |
| 2188 | PROCLIST_FOREACH(p, &allproc) { |
| 2189 | if (p->p_stat == SIDL) { |
| 2190 | /* skip embryonic processes */ |
| 2191 | continue; |
| 2192 | } |
| 2193 | if (arg > 0 && p->p_pid != arg) { |
| 2194 | /* pick only the one we want */ |
| 2195 | /* XXX want 0 to mean "kernel files" */ |
| 2196 | continue; |
| 2197 | } |
| 2198 | mutex_enter(p->p_lock); |
| 2199 | error = kauth_authorize_process(l->l_cred, |
| 2200 | KAUTH_PROCESS_CANSEE, p, |
| 2201 | KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_OPENFILES), |
| 2202 | NULL, NULL); |
| 2203 | mutex_exit(p->p_lock); |
| 2204 | if (error != 0) { |
| 2205 | /* |
| 2206 | * Don't leak kauth retval if we're silently |
| 2207 | * skipping this entry. |
| 2208 | */ |
| 2209 | error = 0; |
| 2210 | continue; |
| 2211 | } |
| 2212 | |
| 2213 | /* |
| 2214 | * Grab a hold on the process. |
| 2215 | */ |
| 2216 | if (!rw_tryenter(&p->p_reflock, RW_READER)) { |
| 2217 | continue; |
| 2218 | } |
| 2219 | mutex_exit(proc_lock); |
| 2220 | |
| 2221 | fd = p->p_fd; |
| 2222 | mutex_enter(&fd->fd_lock); |
| 2223 | dt = fd->fd_dt; |
| 2224 | for (i = 0; i < dt->dt_nfiles; i++) { |
| 2225 | if ((ff = dt->dt_ff[i]) == NULL) { |
| 2226 | continue; |
| 2227 | } |
| 2228 | if ((fp = ff->ff_file) == NULL) { |
| 2229 | continue; |
| 2230 | } |
| 2231 | |
| 2232 | if ((op == KERN_FILE_BYFILE) && |
| 2233 | (fp->f_marker == sysctl_file_marker)) { |
| 2234 | continue; |
| 2235 | } |
| 2236 | if (len >= elem_size && elem_count > 0) { |
| 2237 | mutex_enter(&fp->f_lock); |
| 2238 | fill_file(&kf, fp, ff, i, p->p_pid); |
| 2239 | mutex_exit(&fp->f_lock); |
| 2240 | mutex_exit(&fd->fd_lock); |
| 2241 | error = sysctl_copyout(l, |
| 2242 | &kf, dp, out_size); |
| 2243 | mutex_enter(&fd->fd_lock); |
| 2244 | if (error) |
| 2245 | break; |
| 2246 | dp += elem_size; |
| 2247 | len -= elem_size; |
| 2248 | } |
| 2249 | if (op == KERN_FILE_BYFILE) |
| 2250 | fp->f_marker = sysctl_file_marker; |
| 2251 | needed += elem_size; |
| 2252 | if (elem_count > 0 && elem_count != INT_MAX) |
| 2253 | elem_count--; |
| 2254 | } |
| 2255 | mutex_exit(&fd->fd_lock); |
| 2256 | |
| 2257 | /* |
| 2258 | * Release reference to process. |
| 2259 | */ |
| 2260 | mutex_enter(proc_lock); |
| 2261 | rw_exit(&p->p_reflock); |
| 2262 | } |
| 2263 | if (op == KERN_FILE_BYFILE) { |
| 2264 | sysctl_file_marker++; |
| 2265 | |
| 2266 | /* Reset all markers if wrapped. */ |
| 2267 | if (sysctl_file_marker == 0) { |
| 2268 | sysctl_file_marker_reset(); |
| 2269 | sysctl_file_marker++; |
| 2270 | } |
| 2271 | } |
| 2272 | mutex_exit(proc_lock); |
| 2273 | if (op == KERN_FILE_BYFILE) |
| 2274 | mutex_exit(&sysctl_file_marker_lock); |
| 2275 | sysctl_relock(); |
| 2276 | break; |
| 2277 | default: |
| 2278 | return EINVAL; |
| 2279 | } |
| 2280 | |
| 2281 | if (oldp == NULL) |
| 2282 | needed += KERN_FILESLOP * elem_size; |
| 2283 | *oldlenp = needed; |
| 2284 | |
| 2285 | return error; |
| 2286 | } |
| 2287 | |
| 2288 | static void |
| 2289 | fill_file(struct kinfo_file *kp, const file_t *fp, const fdfile_t *ff, |
| 2290 | int i, pid_t pid) |
| 2291 | { |
| 2292 | |
| 2293 | memset(kp, 0, sizeof(*kp)); |
| 2294 | |
| 2295 | kp->ki_fileaddr = PTRTOUINT64(fp); |
| 2296 | kp->ki_flag = fp->f_flag; |
| 2297 | kp->ki_iflags = 0; |
| 2298 | kp->ki_ftype = fp->f_type; |
| 2299 | kp->ki_count = fp->f_count; |
| 2300 | kp->ki_msgcount = fp->f_msgcount; |
| 2301 | kp->ki_fucred = PTRTOUINT64(fp->f_cred); |
| 2302 | kp->ki_fuid = kauth_cred_geteuid(fp->f_cred); |
| 2303 | kp->ki_fgid = kauth_cred_getegid(fp->f_cred); |
| 2304 | kp->ki_fops = PTRTOUINT64(fp->f_ops); |
| 2305 | kp->ki_foffset = fp->f_offset; |
| 2306 | kp->ki_fdata = PTRTOUINT64(fp->f_data); |
| 2307 | |
| 2308 | /* vnode information to glue this file to something */ |
| 2309 | if (fp->f_type == DTYPE_VNODE) { |
| 2310 | struct vnode *vp = fp->f_vnode; |
| 2311 | |
| 2312 | kp->ki_vun = PTRTOUINT64(vp->v_un.vu_socket); |
| 2313 | kp->ki_vsize = vp->v_size; |
| 2314 | kp->ki_vtype = vp->v_type; |
| 2315 | kp->ki_vtag = vp->v_tag; |
| 2316 | kp->ki_vdata = PTRTOUINT64(vp->v_data); |
| 2317 | } |
| 2318 | |
| 2319 | /* process information when retrieved via KERN_FILE_BYPID */ |
| 2320 | if (ff != NULL) { |
| 2321 | kp->ki_pid = pid; |
| 2322 | kp->ki_fd = i; |
| 2323 | kp->ki_ofileflags = ff->ff_exclose; |
| 2324 | kp->ki_usecount = ff->ff_refcnt; |
| 2325 | } |
| 2326 | } |
| 2327 | |