1 /* $NetBSD: kern_descrip.c,v 1.139 2005/12/24 19:12:23 perry Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.8 (Berkeley) 2/14/95 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.139 2005/12/24 19:12:23 perry Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/filedesc.h> 45 #include <sys/kernel.h> 46 #include <sys/vnode.h> 47 #include <sys/proc.h> 48 #include <sys/file.h> 49 #include <sys/namei.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/stat.h> 53 #include <sys/ioctl.h> 54 #include <sys/fcntl.h> 55 #include <sys/malloc.h> 56 #include <sys/pool.h> 57 #include <sys/syslog.h> 58 #include <sys/unistd.h> 59 #include <sys/resourcevar.h> 60 #include <sys/conf.h> 61 #include <sys/event.h> 62 63 #include <sys/mount.h> 64 #include <sys/sa.h> 65 #include <sys/syscallargs.h> 66 67 /* 68 * Descriptor management. 69 */ 70 struct filelist filehead; /* head of list of open files */ 71 int nfiles; /* actual number of open files */ 72 POOL_INIT(file_pool, sizeof(struct file), 0, 0, 0, "filepl", 73 &pool_allocator_nointr); 74 POOL_INIT(cwdi_pool, sizeof(struct cwdinfo), 0, 0, 0, "cwdipl", 75 &pool_allocator_nointr); 76 POOL_INIT(filedesc0_pool, sizeof(struct filedesc0), 0, 0, 0, "fdescpl", 77 &pool_allocator_nointr); 78 79 /* Global file list lock */ 80 static struct simplelock filelist_slock = SIMPLELOCK_INITIALIZER; 81 82 MALLOC_DEFINE(M_FILE, "file", "Open file structure"); 83 MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table"); 84 MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 85 86 static inline int 87 find_next_zero(uint32_t *bitmap, int want, u_int bits) 88 { 89 int i, off, maxoff; 90 uint32_t sub; 91 92 if (want > bits) 93 return -1; 94 95 off = want >> NDENTRYSHIFT; 96 i = want & NDENTRYMASK; 97 if (i) { 98 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i)); 99 if (sub != ~0) 100 goto found; 101 off++; 102 } 103 104 maxoff = NDLOSLOTS(bits); 105 while (off < maxoff) { 106 if ((sub = bitmap[off]) != ~0) 107 goto found; 108 off++; 109 } 110 111 return (-1); 112 113 found: 114 return (off << NDENTRYSHIFT) + ffs(~sub) - 1; 115 } 116 117 static int 118 find_last_set(struct filedesc *fd, int last) 119 { 120 int off, i; 121 struct file **ofiles = fd->fd_ofiles; 122 uint32_t *bitmap = fd->fd_lomap; 123 124 off = (last - 1) >> NDENTRYSHIFT; 125 126 while (off >= 0 && !bitmap[off]) 127 off--; 128 129 if (off < 0) 130 return (-1); 131 132 i = ((off + 1) << NDENTRYSHIFT) - 1; 133 if (i >= last) 134 i = last - 1; 135 136 while (i > 0 && ofiles[i] == NULL) 137 i--; 138 139 return (i); 140 } 141 142 static inline void 143 fd_used(struct filedesc *fdp, int fd) 144 { 145 u_int off = fd >> NDENTRYSHIFT; 146 147 LOCK_ASSERT(simple_lock_held(&fdp->fd_slock)); 148 KDASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) == 0); 149 150 fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK); 151 if (fdp->fd_lomap[off] == ~0) { 152 KDASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 153 (1 << (off & NDENTRYMASK))) == 0); 154 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK); 155 } 156 157 if (fd > fdp->fd_lastfile) 158 fdp->fd_lastfile = fd; 159 } 160 161 static inline void 162 fd_unused(struct filedesc *fdp, int fd) 163 { 164 u_int off = fd >> NDENTRYSHIFT; 165 166 LOCK_ASSERT(simple_lock_held(&fdp->fd_slock)); 167 if (fd < fdp->fd_freefile) 168 fdp->fd_freefile = fd; 169 170 if (fdp->fd_lomap[off] == ~0) { 171 KDASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] & 172 (1 << (off & NDENTRYMASK))) != 0); 173 fdp->fd_himap[off >> NDENTRYSHIFT] &= 174 ~(1 << (off & NDENTRYMASK)); 175 } 176 KDASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0); 177 fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK)); 178 179 #ifdef DIAGNOSTIC 180 if (fd > fdp->fd_lastfile) 181 panic("fd_unused: fd_lastfile inconsistent"); 182 #endif 183 if (fd == fdp->fd_lastfile) 184 fdp->fd_lastfile = find_last_set(fdp, fd); 185 } 186 187 /* 188 * Lookup the file structure corresponding to a file descriptor 189 * and return it locked. 190 * Note: typical usage is: `fp = fd_getfile(..); FILE_USE(fp);' 191 * The locking strategy has been optimised for this case, i.e. 192 * fd_getfile() returns the file locked while FILE_USE() will increment 193 * the file's use count and unlock. 194 */ 195 struct file * 196 fd_getfile(struct filedesc *fdp, int fd) 197 { 198 struct file *fp; 199 200 if ((u_int) fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) 201 return (NULL); 202 203 simple_lock(&fp->f_slock); 204 if (FILE_IS_USABLE(fp) == 0) { 205 simple_unlock(&fp->f_slock); 206 return (NULL); 207 } 208 209 return (fp); 210 } 211 212 /* 213 * Common code for dup, dup2, and fcntl(F_DUPFD). 214 */ 215 static int 216 finishdup(struct lwp *l, int old, int new, register_t *retval) 217 { 218 struct filedesc *fdp; 219 struct file *fp, *delfp; 220 221 fdp = l->l_proc->p_fd; 222 223 /* 224 * If there is a file in the new slot, remember it so we 225 * can close it after we've finished the dup. We need 226 * to do it after the dup is finished, since closing 227 * the file may block. 228 * 229 * Note: `old' is already used for us. 230 * Note: Caller already marked `new' slot "used". 231 */ 232 simple_lock(&fdp->fd_slock); 233 delfp = fdp->fd_ofiles[new]; 234 235 fp = fdp->fd_ofiles[old]; 236 KDASSERT(fp != NULL); 237 fdp->fd_ofiles[new] = fp; 238 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 239 simple_unlock(&fdp->fd_slock); 240 241 *retval = new; 242 simple_lock(&fp->f_slock); 243 fp->f_count++; 244 FILE_UNUSE_HAVELOCK(fp, l); 245 246 if (delfp != NULL) { 247 simple_lock(&delfp->f_slock); 248 FILE_USE(delfp); 249 if (new < fdp->fd_knlistsize) 250 knote_fdclose(l, new); 251 (void) closef(delfp, l); 252 } 253 return (0); 254 } 255 256 /* 257 * System calls on descriptors. 258 */ 259 260 /* 261 * Duplicate a file descriptor. 262 */ 263 /* ARGSUSED */ 264 int 265 sys_dup(struct lwp *l, void *v, register_t *retval) 266 { 267 struct sys_dup_args /* { 268 syscallarg(int) fd; 269 } */ *uap = v; 270 struct file *fp; 271 struct filedesc *fdp; 272 struct proc *p; 273 int old, new, error; 274 275 p = l->l_proc; 276 fdp = p->p_fd; 277 old = SCARG(uap, fd); 278 279 restart: 280 if ((fp = fd_getfile(fdp, old)) == NULL) 281 return (EBADF); 282 283 FILE_USE(fp); 284 285 if ((error = fdalloc(p, 0, &new)) != 0) { 286 if (error == ENOSPC) { 287 fdexpand(p); 288 FILE_UNUSE(fp, l); 289 goto restart; 290 } 291 FILE_UNUSE(fp, l); 292 return (error); 293 } 294 295 /* finishdup() will unuse the descriptors for us */ 296 return (finishdup(l, old, new, retval)); 297 } 298 299 /* 300 * Duplicate a file descriptor to a particular value. 301 */ 302 /* ARGSUSED */ 303 int 304 sys_dup2(struct lwp *l, void *v, register_t *retval) 305 { 306 struct sys_dup2_args /* { 307 syscallarg(int) from; 308 syscallarg(int) to; 309 } */ *uap = v; 310 struct file *fp; 311 struct filedesc *fdp; 312 struct proc *p; 313 int old, new, i, error; 314 315 p = l->l_proc; 316 fdp = p->p_fd; 317 old = SCARG(uap, from); 318 new = SCARG(uap, to); 319 320 restart: 321 if ((fp = fd_getfile(fdp, old)) == NULL) 322 return (EBADF); 323 324 if ((u_int)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 325 (u_int)new >= maxfiles) { 326 simple_unlock(&fp->f_slock); 327 return (EBADF); 328 } 329 330 if (old == new) { 331 simple_unlock(&fp->f_slock); 332 *retval = new; 333 return (0); 334 } 335 336 FILE_USE(fp); 337 338 if (new >= fdp->fd_nfiles) { 339 if ((error = fdalloc(p, new, &i)) != 0) { 340 if (error == ENOSPC) { 341 fdexpand(p); 342 FILE_UNUSE(fp, l); 343 goto restart; 344 } 345 FILE_UNUSE(fp, l); 346 return (error); 347 } 348 if (new != i) 349 panic("dup2: fdalloc"); 350 } else { 351 simple_lock(&fdp->fd_slock); 352 /* 353 * Mark `new' slot "used" only if it was empty. 354 */ 355 if (fdp->fd_ofiles[new] == NULL) 356 fd_used(fdp, new); 357 simple_unlock(&fdp->fd_slock); 358 } 359 360 /* 361 * finishdup() will close the file that's in the `new' 362 * slot, if there's one there. 363 */ 364 365 /* finishdup() will unuse the descriptors for us */ 366 return (finishdup(l, old, new, retval)); 367 } 368 369 /* 370 * fcntl call which is being passed to the file's fs. 371 */ 372 static int 373 fcntl_forfs(int fd, struct lwp *l, int cmd, void *arg) 374 { 375 struct file *fp; 376 struct filedesc *fdp; 377 int error; 378 u_int size; 379 void *data, *memp; 380 #define STK_PARAMS 128 381 char stkbuf[STK_PARAMS]; 382 383 /* fd's value was validated in sys_fcntl before calling this routine */ 384 fdp = l->l_proc->p_fd; 385 fp = fdp->fd_ofiles[fd]; 386 387 if ((fp->f_flag & (FREAD | FWRITE)) == 0) 388 return (EBADF); 389 390 /* 391 * Interpret high order word to find amount of data to be 392 * copied to/from the user's address space. 393 */ 394 size = (size_t)F_PARAM_LEN(cmd); 395 if (size > F_PARAM_MAX) 396 return (EINVAL); 397 memp = NULL; 398 if (size > sizeof(stkbuf)) { 399 memp = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 400 data = memp; 401 } else 402 data = stkbuf; 403 if (cmd & F_FSIN) { 404 if (size) { 405 error = copyin(arg, data, size); 406 if (error) { 407 if (memp) 408 free(memp, M_IOCTLOPS); 409 return (error); 410 } 411 } else 412 *(void **)data = arg; 413 } else if ((cmd & F_FSOUT) && size) 414 /* 415 * Zero the buffer so the user always 416 * gets back something deterministic. 417 */ 418 memset(data, 0, size); 419 else if (cmd & F_FSVOID) 420 *(void **)data = arg; 421 422 423 error = (*fp->f_ops->fo_fcntl)(fp, cmd, data, l); 424 425 /* 426 * Copy any data to user, size was 427 * already set and checked above. 428 */ 429 if (error == 0 && (cmd & F_FSOUT) && size) 430 error = copyout(data, arg, size); 431 if (memp) 432 free(memp, M_IOCTLOPS); 433 return (error); 434 } 435 436 /* 437 * The file control system call. 438 */ 439 /* ARGSUSED */ 440 int 441 sys_fcntl(struct lwp *l, void *v, register_t *retval) 442 { 443 struct sys_fcntl_args /* { 444 syscallarg(int) fd; 445 syscallarg(int) cmd; 446 syscallarg(void *) arg; 447 } */ *uap = v; 448 struct filedesc *fdp; 449 struct file *fp; 450 struct proc *p; 451 struct vnode *vp; 452 int fd, i, tmp, error, flg, cmd, newmin; 453 struct flock fl; 454 455 p = l->l_proc; 456 fd = SCARG(uap, fd); 457 cmd = SCARG(uap, cmd); 458 fdp = p->p_fd; 459 error = 0; 460 flg = F_POSIX; 461 462 switch (cmd) { 463 case F_CLOSEM: 464 if (fd < 0) 465 return EBADF; 466 while (fdp->fd_lastfile >= fd) 467 fdrelease(l, fdp->fd_lastfile); 468 return 0; 469 470 case F_MAXFD: 471 *retval = fdp->fd_lastfile; 472 return 0; 473 474 default: 475 /* Handled below */ 476 break; 477 } 478 479 restart: 480 if ((fp = fd_getfile(fdp, fd)) == NULL) 481 return (EBADF); 482 483 FILE_USE(fp); 484 485 if ((cmd & F_FSCTL)) { 486 error = fcntl_forfs(fd, l, cmd, SCARG(uap, arg)); 487 goto out; 488 } 489 490 switch (cmd) { 491 492 case F_DUPFD: 493 newmin = (long)SCARG(uap, arg); 494 if ((u_int)newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 495 (u_int)newmin >= maxfiles) { 496 error = EINVAL; 497 goto out; 498 } 499 if ((error = fdalloc(p, newmin, &i)) != 0) { 500 if (error == ENOSPC) { 501 fdexpand(p); 502 FILE_UNUSE(fp, l); 503 goto restart; 504 } 505 goto out; 506 } 507 508 /* finishdup() will unuse the descriptors for us */ 509 return (finishdup(l, fd, i, retval)); 510 511 case F_GETFD: 512 *retval = fdp->fd_ofileflags[fd] & UF_EXCLOSE ? 1 : 0; 513 break; 514 515 case F_SETFD: 516 if ((long)SCARG(uap, arg) & 1) 517 fdp->fd_ofileflags[fd] |= UF_EXCLOSE; 518 else 519 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE; 520 break; 521 522 case F_GETFL: 523 *retval = OFLAGS(fp->f_flag); 524 break; 525 526 case F_SETFL: 527 tmp = FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS; 528 error = (*fp->f_ops->fo_fcntl)(fp, F_SETFL, &tmp, l); 529 if (error) 530 break; 531 i = tmp ^ fp->f_flag; 532 if (i & FNONBLOCK) { 533 int flgs = tmp & FNONBLOCK; 534 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, &flgs, l); 535 if (error) 536 goto reset_fcntl; 537 } 538 if (i & FASYNC) { 539 int flgs = tmp & FASYNC; 540 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, &flgs, l); 541 if (error) { 542 if (i & FNONBLOCK) { 543 tmp = fp->f_flag & FNONBLOCK; 544 (void)(*fp->f_ops->fo_ioctl)(fp, 545 FIONBIO, &tmp, l); 546 } 547 goto reset_fcntl; 548 } 549 } 550 fp->f_flag = (fp->f_flag & ~FCNTLFLAGS) | tmp; 551 break; 552 reset_fcntl: 553 (void)(*fp->f_ops->fo_fcntl)(fp, F_SETFL, &fp->f_flag, l); 554 break; 555 556 case F_GETOWN: 557 error = (*fp->f_ops->fo_ioctl)(fp, FIOGETOWN, &tmp, l); 558 *retval = tmp; 559 break; 560 561 case F_SETOWN: 562 tmp = (int)(intptr_t) SCARG(uap, arg); 563 error = (*fp->f_ops->fo_ioctl)(fp, FIOSETOWN, &tmp, l); 564 break; 565 566 case F_SETLKW: 567 flg |= F_WAIT; 568 /* Fall into F_SETLK */ 569 570 case F_SETLK: 571 if (fp->f_type != DTYPE_VNODE) { 572 error = EINVAL; 573 goto out; 574 } 575 vp = (struct vnode *)fp->f_data; 576 /* Copy in the lock structure */ 577 error = copyin(SCARG(uap, arg), &fl, sizeof(fl)); 578 if (error) 579 goto out; 580 if (fl.l_whence == SEEK_CUR) 581 fl.l_start += fp->f_offset; 582 switch (fl.l_type) { 583 case F_RDLCK: 584 if ((fp->f_flag & FREAD) == 0) { 585 error = EBADF; 586 goto out; 587 } 588 p->p_flag |= P_ADVLOCK; 589 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg); 590 goto out; 591 592 case F_WRLCK: 593 if ((fp->f_flag & FWRITE) == 0) { 594 error = EBADF; 595 goto out; 596 } 597 p->p_flag |= P_ADVLOCK; 598 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg); 599 goto out; 600 601 case F_UNLCK: 602 error = VOP_ADVLOCK(vp, p, F_UNLCK, &fl, F_POSIX); 603 goto out; 604 605 default: 606 error = EINVAL; 607 goto out; 608 } 609 610 case F_GETLK: 611 if (fp->f_type != DTYPE_VNODE) { 612 error = EINVAL; 613 goto out; 614 } 615 vp = (struct vnode *)fp->f_data; 616 /* Copy in the lock structure */ 617 error = copyin(SCARG(uap, arg), &fl, sizeof(fl)); 618 if (error) 619 goto out; 620 if (fl.l_whence == SEEK_CUR) 621 fl.l_start += fp->f_offset; 622 if (fl.l_type != F_RDLCK && 623 fl.l_type != F_WRLCK && 624 fl.l_type != F_UNLCK) { 625 error = EINVAL; 626 goto out; 627 } 628 error = VOP_ADVLOCK(vp, p, F_GETLK, &fl, F_POSIX); 629 if (error) 630 goto out; 631 error = copyout(&fl, SCARG(uap, arg), sizeof(fl)); 632 break; 633 634 default: 635 error = EINVAL; 636 } 637 638 out: 639 FILE_UNUSE(fp, l); 640 return (error); 641 } 642 643 void 644 fdremove(struct filedesc *fdp, int fd) 645 { 646 647 simple_lock(&fdp->fd_slock); 648 fdp->fd_ofiles[fd] = NULL; 649 fd_unused(fdp, fd); 650 simple_unlock(&fdp->fd_slock); 651 } 652 653 int 654 fdrelease(struct lwp *l, int fd) 655 { 656 struct proc *p = l->l_proc; 657 struct filedesc *fdp; 658 struct file **fpp, *fp; 659 660 fdp = p->p_fd; 661 simple_lock(&fdp->fd_slock); 662 if (fd < 0 || fd > fdp->fd_lastfile) 663 goto badf; 664 fpp = &fdp->fd_ofiles[fd]; 665 fp = *fpp; 666 if (fp == NULL) 667 goto badf; 668 669 simple_lock(&fp->f_slock); 670 if (!FILE_IS_USABLE(fp)) { 671 simple_unlock(&fp->f_slock); 672 goto badf; 673 } 674 675 FILE_USE(fp); 676 677 *fpp = NULL; 678 fdp->fd_ofileflags[fd] = 0; 679 fd_unused(fdp, fd); 680 simple_unlock(&fdp->fd_slock); 681 if (fd < fdp->fd_knlistsize) 682 knote_fdclose(l, fd); 683 return (closef(fp, l)); 684 685 badf: 686 simple_unlock(&fdp->fd_slock); 687 return (EBADF); 688 } 689 690 /* 691 * Close a file descriptor. 692 */ 693 /* ARGSUSED */ 694 int 695 sys_close(struct lwp *l, void *v, register_t *retval) 696 { 697 struct sys_close_args /* { 698 syscallarg(int) fd; 699 } */ *uap = v; 700 int fd; 701 struct filedesc *fdp; 702 struct proc *p; 703 704 p = l->l_proc; 705 fd = SCARG(uap, fd); 706 fdp = p->p_fd; 707 708 #if 0 709 if (fd_getfile(fdp, fd) == NULL) 710 return (EBADF); 711 #endif 712 713 return (fdrelease(l, fd)); 714 } 715 716 /* 717 * Return status information about a file descriptor. 718 */ 719 /* ARGSUSED */ 720 int 721 sys___fstat30(struct lwp *l, void *v, register_t *retval) 722 { 723 struct sys___fstat30_args /* { 724 syscallarg(int) fd; 725 syscallarg(struct stat *) sb; 726 } */ *uap = v; 727 int fd; 728 struct filedesc *fdp; 729 struct file *fp; 730 struct proc *p; 731 struct stat ub; 732 int error; 733 734 p = l->l_proc; 735 fd = SCARG(uap, fd); 736 fdp = p->p_fd; 737 738 if ((fp = fd_getfile(fdp, fd)) == NULL) 739 return (EBADF); 740 741 FILE_USE(fp); 742 error = (*fp->f_ops->fo_stat)(fp, &ub, l); 743 FILE_UNUSE(fp, l); 744 745 if (error == 0) 746 error = copyout(&ub, SCARG(uap, sb), sizeof(ub)); 747 748 return (error); 749 } 750 751 /* 752 * Return pathconf information about a file descriptor. 753 */ 754 /* ARGSUSED */ 755 int 756 sys_fpathconf(struct lwp *l, void *v, register_t *retval) 757 { 758 struct sys_fpathconf_args /* { 759 syscallarg(int) fd; 760 syscallarg(int) name; 761 } */ *uap = v; 762 int fd; 763 struct filedesc *fdp; 764 struct file *fp; 765 struct proc *p; 766 struct vnode *vp; 767 int error; 768 769 p = l->l_proc; 770 fd = SCARG(uap, fd); 771 fdp = p->p_fd; 772 error = 0; 773 774 if ((fp = fd_getfile(fdp, fd)) == NULL) 775 return (EBADF); 776 777 FILE_USE(fp); 778 779 switch (fp->f_type) { 780 781 case DTYPE_SOCKET: 782 case DTYPE_PIPE: 783 if (SCARG(uap, name) != _PC_PIPE_BUF) 784 error = EINVAL; 785 else 786 *retval = PIPE_BUF; 787 break; 788 789 case DTYPE_VNODE: 790 vp = (struct vnode *)fp->f_data; 791 error = VOP_PATHCONF(vp, SCARG(uap, name), retval); 792 break; 793 794 case DTYPE_KQUEUE: 795 error = EINVAL; 796 break; 797 798 default: 799 error = EOPNOTSUPP; 800 break; 801 } 802 803 FILE_UNUSE(fp, l); 804 return (error); 805 } 806 807 /* 808 * Allocate a file descriptor for the process. 809 */ 810 int fdexpanded; /* XXX: what else uses this? */ 811 812 int 813 fdalloc(struct proc *p, int want, int *result) 814 { 815 struct filedesc *fdp; 816 int i, lim, last, error; 817 u_int off, new; 818 819 fdp = p->p_fd; 820 simple_lock(&fdp->fd_slock); 821 822 /* 823 * Search for a free descriptor starting at the higher 824 * of want or fd_freefile. If that fails, consider 825 * expanding the ofile array. 826 */ 827 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 828 last = min(fdp->fd_nfiles, lim); 829 again: 830 if ((i = want) < fdp->fd_freefile) 831 i = fdp->fd_freefile; 832 off = i >> NDENTRYSHIFT; 833 new = find_next_zero(fdp->fd_himap, off, 834 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 835 if (new != -1) { 836 i = find_next_zero(&fdp->fd_lomap[new], 837 new > off ? 0 : i & NDENTRYMASK, NDENTRIES); 838 if (i == -1) { 839 /* 840 * free file descriptor in this block was 841 * below want, try again with higher want. 842 */ 843 want = (new + 1) << NDENTRYSHIFT; 844 goto again; 845 } 846 i += (new << NDENTRYSHIFT); 847 if (i < last) { 848 if (fdp->fd_ofiles[i] == NULL) { 849 fd_used(fdp, i); 850 if (want <= fdp->fd_freefile) 851 fdp->fd_freefile = i; 852 *result = i; 853 error = 0; 854 goto out; 855 } 856 } 857 } 858 859 /* No space in current array. Expand or let the caller do it. */ 860 error = (fdp->fd_nfiles >= lim) ? EMFILE : ENOSPC; 861 862 out: 863 simple_unlock(&fdp->fd_slock); 864 return (error); 865 } 866 867 void 868 fdexpand(struct proc *p) 869 { 870 struct filedesc *fdp; 871 int i, numfiles, oldnfiles; 872 struct file **newofile; 873 char *newofileflags; 874 uint32_t *newhimap = NULL, *newlomap = NULL; 875 876 fdp = p->p_fd; 877 878 restart: 879 oldnfiles = fdp->fd_nfiles; 880 881 if (oldnfiles < NDEXTENT) 882 numfiles = NDEXTENT; 883 else 884 numfiles = 2 * oldnfiles; 885 886 newofile = malloc(numfiles * OFILESIZE, M_FILEDESC, M_WAITOK); 887 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 888 newhimap = malloc(NDHISLOTS(numfiles) * sizeof(uint32_t), 889 M_FILEDESC, M_WAITOK); 890 newlomap = malloc(NDLOSLOTS(numfiles) * sizeof(uint32_t), 891 M_FILEDESC, M_WAITOK); 892 } 893 894 simple_lock(&fdp->fd_slock); 895 /* lock fdp */ 896 if (fdp->fd_nfiles != oldnfiles) { 897 /* fdp changed; retry */ 898 simple_unlock(&fdp->fd_slock); 899 free(newofile, M_FILEDESC); 900 if (newhimap != NULL) free(newhimap, M_FILEDESC); 901 if (newlomap != NULL) free(newlomap, M_FILEDESC); 902 goto restart; 903 } 904 905 newofileflags = (char *) &newofile[numfiles]; 906 /* 907 * Copy the existing ofile and ofileflags arrays 908 * and zero the new portion of each array. 909 */ 910 memcpy(newofile, fdp->fd_ofiles, 911 (i = sizeof(struct file *) * fdp->fd_nfiles)); 912 memset((char *)newofile + i, 0, 913 numfiles * sizeof(struct file *) - i); 914 memcpy(newofileflags, fdp->fd_ofileflags, 915 (i = sizeof(char) * fdp->fd_nfiles)); 916 memset(newofileflags + i, 0, numfiles * sizeof(char) - i); 917 if (oldnfiles > NDFILE) 918 free(fdp->fd_ofiles, M_FILEDESC); 919 920 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 921 memcpy(newhimap, fdp->fd_himap, 922 (i = NDHISLOTS(oldnfiles) * sizeof(uint32_t))); 923 memset((char *)newhimap + i, 0, 924 NDHISLOTS(numfiles) * sizeof(uint32_t) - i); 925 926 memcpy(newlomap, fdp->fd_lomap, 927 (i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t))); 928 memset((char *)newlomap + i, 0, 929 NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); 930 931 if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { 932 free(fdp->fd_himap, M_FILEDESC); 933 free(fdp->fd_lomap, M_FILEDESC); 934 } 935 fdp->fd_himap = newhimap; 936 fdp->fd_lomap = newlomap; 937 } 938 939 fdp->fd_ofiles = newofile; 940 fdp->fd_ofileflags = newofileflags; 941 fdp->fd_nfiles = numfiles; 942 943 simple_unlock(&fdp->fd_slock); 944 945 fdexpanded++; 946 } 947 948 /* 949 * Check to see whether n user file descriptors 950 * are available to the process p. 951 */ 952 int 953 fdavail(struct proc *p, int n) 954 { 955 struct filedesc *fdp; 956 struct file **fpp; 957 int i, lim; 958 959 fdp = p->p_fd; 960 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 961 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 962 return (1); 963 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 964 for (i = min(lim,fdp->fd_nfiles) - fdp->fd_freefile; --i >= 0; fpp++) 965 if (*fpp == NULL && --n <= 0) 966 return (1); 967 return (0); 968 } 969 970 /* 971 * Create a new open file structure and allocate 972 * a file descriptor for the process that refers to it. 973 */ 974 int 975 falloc(struct proc *p, struct file **resultfp, int *resultfd) 976 { 977 struct file *fp, *fq; 978 int error, i; 979 980 restart: 981 if ((error = fdalloc(p, 0, &i)) != 0) { 982 if (error == ENOSPC) { 983 fdexpand(p); 984 goto restart; 985 } 986 return (error); 987 } 988 989 fp = pool_get(&file_pool, PR_WAITOK); 990 simple_lock(&filelist_slock); 991 if (nfiles >= maxfiles) { 992 tablefull("file", "increase kern.maxfiles or MAXFILES"); 993 simple_unlock(&filelist_slock); 994 fd_unused(p->p_fd, i); 995 pool_put(&file_pool, fp); 996 return (ENFILE); 997 } 998 /* 999 * Allocate a new file descriptor. 1000 * If the process has file descriptor zero open, add to the list 1001 * of open files at that point, otherwise put it at the front of 1002 * the list of open files. 1003 */ 1004 nfiles++; 1005 memset(fp, 0, sizeof(struct file)); 1006 fp->f_iflags = FIF_LARVAL; 1007 if ((fq = p->p_fd->fd_ofiles[0]) != NULL) { 1008 LIST_INSERT_AFTER(fq, fp, f_list); 1009 } else { 1010 LIST_INSERT_HEAD(&filehead, fp, f_list); 1011 } 1012 simple_unlock(&filelist_slock); 1013 KDASSERT(p->p_fd->fd_ofiles[i] == NULL); 1014 p->p_fd->fd_ofiles[i] = fp; 1015 simple_lock_init(&fp->f_slock); 1016 fp->f_count = 1; 1017 fp->f_cred = p->p_ucred; 1018 crhold(fp->f_cred); 1019 if (resultfp) { 1020 fp->f_usecount = 1; 1021 *resultfp = fp; 1022 } 1023 if (resultfd) 1024 *resultfd = i; 1025 return (0); 1026 } 1027 1028 /* 1029 * Free a file descriptor. 1030 */ 1031 void 1032 ffree(struct file *fp) 1033 { 1034 1035 #ifdef DIAGNOSTIC 1036 if (fp->f_usecount) 1037 panic("ffree"); 1038 #endif 1039 1040 simple_lock(&filelist_slock); 1041 LIST_REMOVE(fp, f_list); 1042 crfree(fp->f_cred); 1043 #ifdef DIAGNOSTIC 1044 fp->f_count = 0; /* What's the point? */ 1045 #endif 1046 nfiles--; 1047 simple_unlock(&filelist_slock); 1048 pool_put(&file_pool, fp); 1049 } 1050 1051 /* 1052 * Create an initial cwdinfo structure, using the same current and root 1053 * directories as p. 1054 */ 1055 struct cwdinfo * 1056 cwdinit(struct proc *p) 1057 { 1058 struct cwdinfo *cwdi; 1059 1060 cwdi = pool_get(&cwdi_pool, PR_WAITOK); 1061 1062 simple_lock_init(&cwdi->cwdi_slock); 1063 cwdi->cwdi_cdir = p->p_cwdi->cwdi_cdir; 1064 if (cwdi->cwdi_cdir) 1065 VREF(cwdi->cwdi_cdir); 1066 cwdi->cwdi_rdir = p->p_cwdi->cwdi_rdir; 1067 if (cwdi->cwdi_rdir) 1068 VREF(cwdi->cwdi_rdir); 1069 cwdi->cwdi_cmask = p->p_cwdi->cwdi_cmask; 1070 cwdi->cwdi_refcnt = 1; 1071 1072 return (cwdi); 1073 } 1074 1075 /* 1076 * Make p2 share p1's cwdinfo. 1077 */ 1078 void 1079 cwdshare(struct proc *p1, struct proc *p2) 1080 { 1081 struct cwdinfo *cwdi = p1->p_cwdi; 1082 1083 simple_lock(&cwdi->cwdi_slock); 1084 cwdi->cwdi_refcnt++; 1085 simple_unlock(&cwdi->cwdi_slock); 1086 p2->p_cwdi = cwdi; 1087 } 1088 1089 /* 1090 * Make this process not share its cwdinfo structure, maintaining 1091 * all cwdinfo state. 1092 */ 1093 void 1094 cwdunshare(struct proc *p) 1095 { 1096 struct cwdinfo *oldcwdi, *newcwdi; 1097 1098 if (p->p_cwdi->cwdi_refcnt == 1) 1099 return; 1100 1101 newcwdi = cwdinit(p); 1102 oldcwdi = p->p_cwdi; 1103 p->p_cwdi = newcwdi; 1104 cwdfree(oldcwdi); 1105 } 1106 1107 /* 1108 * Release a cwdinfo structure. 1109 */ 1110 void 1111 cwdfree(struct cwdinfo *cwdi) 1112 { 1113 int n; 1114 1115 simple_lock(&cwdi->cwdi_slock); 1116 n = --cwdi->cwdi_refcnt; 1117 simple_unlock(&cwdi->cwdi_slock); 1118 if (n > 0) 1119 return; 1120 1121 vrele(cwdi->cwdi_cdir); 1122 if (cwdi->cwdi_rdir) 1123 vrele(cwdi->cwdi_rdir); 1124 pool_put(&cwdi_pool, cwdi); 1125 } 1126 1127 /* 1128 * Create an initial filedesc structure, using the same current and root 1129 * directories as p. 1130 */ 1131 struct filedesc * 1132 fdinit(struct proc *p) 1133 { 1134 struct filedesc0 *newfdp; 1135 1136 newfdp = pool_get(&filedesc0_pool, PR_WAITOK); 1137 memset(newfdp, 0, sizeof(struct filedesc0)); 1138 1139 fdinit1(newfdp); 1140 1141 return (&newfdp->fd_fd); 1142 } 1143 1144 /* 1145 * Initialize a file descriptor table. 1146 */ 1147 void 1148 fdinit1(struct filedesc0 *newfdp) 1149 { 1150 1151 newfdp->fd_fd.fd_refcnt = 1; 1152 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1153 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1154 newfdp->fd_fd.fd_nfiles = NDFILE; 1155 newfdp->fd_fd.fd_knlistsize = -1; 1156 newfdp->fd_fd.fd_himap = newfdp->fd_dhimap; 1157 newfdp->fd_fd.fd_lomap = newfdp->fd_dlomap; 1158 newfdp->fd_fd.fd_lastfile = -1; 1159 simple_lock_init(&newfdp->fd_fd.fd_slock); 1160 } 1161 1162 /* 1163 * Make p2 share p1's filedesc structure. 1164 */ 1165 void 1166 fdshare(struct proc *p1, struct proc *p2) 1167 { 1168 struct filedesc *fdp = p1->p_fd; 1169 1170 simple_lock(&fdp->fd_slock); 1171 p2->p_fd = fdp; 1172 fdp->fd_refcnt++; 1173 simple_unlock(&fdp->fd_slock); 1174 } 1175 1176 /* 1177 * Make this process not share its filedesc structure, maintaining 1178 * all file descriptor state. 1179 */ 1180 void 1181 fdunshare(struct lwp *l) 1182 { 1183 struct proc *p = l->l_proc; 1184 struct filedesc *newfd; 1185 1186 if (p->p_fd->fd_refcnt == 1) 1187 return; 1188 1189 newfd = fdcopy(p); 1190 fdfree(l); 1191 p->p_fd = newfd; 1192 } 1193 1194 /* 1195 * Clear a process's fd table. 1196 */ 1197 void 1198 fdclear(struct lwp *l) 1199 { 1200 struct proc *p = l->l_proc; 1201 struct filedesc *newfd; 1202 1203 newfd = fdinit(p); 1204 fdfree(l); 1205 p->p_fd = newfd; 1206 } 1207 1208 /* 1209 * Copy a filedesc structure. 1210 */ 1211 struct filedesc * 1212 fdcopy(struct proc *p) 1213 { 1214 struct filedesc *newfdp, *fdp; 1215 struct file **fpp, **nfpp; 1216 int i, numfiles, lastfile; 1217 1218 fdp = p->p_fd; 1219 newfdp = pool_get(&filedesc0_pool, PR_WAITOK); 1220 newfdp->fd_refcnt = 1; 1221 simple_lock_init(&newfdp->fd_slock); 1222 1223 restart: 1224 numfiles = fdp->fd_nfiles; 1225 lastfile = fdp->fd_lastfile; 1226 1227 /* 1228 * If the number of open files fits in the internal arrays 1229 * of the open file structure, use them, otherwise allocate 1230 * additional memory for the number of descriptors currently 1231 * in use. 1232 */ 1233 if (lastfile < NDFILE) { 1234 i = NDFILE; 1235 } else { 1236 /* 1237 * Compute the smallest multiple of NDEXTENT needed 1238 * for the file descriptors currently in use, 1239 * allowing the table to shrink. 1240 */ 1241 i = numfiles; 1242 while (i >= 2 * NDEXTENT && i > lastfile * 2) 1243 i /= 2; 1244 newfdp->fd_ofiles = malloc(i * OFILESIZE, M_FILEDESC, M_WAITOK); 1245 } 1246 if (NDHISLOTS(i) > NDHISLOTS(NDFILE)) { 1247 newfdp->fd_himap = malloc(NDHISLOTS(i) * sizeof(uint32_t), 1248 M_FILEDESC, M_WAITOK); 1249 newfdp->fd_lomap = malloc(NDLOSLOTS(i) * sizeof(uint32_t), 1250 M_FILEDESC, M_WAITOK); 1251 } 1252 1253 simple_lock(&fdp->fd_slock); 1254 if (numfiles != fdp->fd_nfiles || lastfile != fdp->fd_lastfile) { 1255 simple_unlock(&fdp->fd_slock); 1256 if (i > NDFILE) 1257 free(newfdp->fd_ofiles, M_FILEDESC); 1258 if (NDHISLOTS(i) > NDHISLOTS(NDFILE)) { 1259 free(newfdp->fd_himap, M_FILEDESC); 1260 free(newfdp->fd_lomap, M_FILEDESC); 1261 } 1262 goto restart; 1263 } 1264 1265 if (lastfile < NDFILE) { 1266 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 1267 newfdp->fd_ofileflags = 1268 ((struct filedesc0 *) newfdp)->fd_dfileflags; 1269 } else { 1270 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1271 } 1272 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { 1273 newfdp->fd_himap = 1274 ((struct filedesc0 *) newfdp)->fd_dhimap; 1275 newfdp->fd_lomap = 1276 ((struct filedesc0 *) newfdp)->fd_dlomap; 1277 } 1278 1279 newfdp->fd_nfiles = i; 1280 newfdp->fd_lastfile = lastfile; 1281 newfdp->fd_freefile = fdp->fd_freefile; 1282 1283 /* Clear the entries that will not be copied over. 1284 * Avoid calling memset with 0 size (i.e. when 1285 * lastfile == i-1 */ 1286 if (lastfile < (i-1)) 1287 memset(newfdp->fd_ofiles + lastfile + 1, 0, 1288 (i - lastfile - 1) * sizeof(struct file **)); 1289 memcpy(newfdp->fd_ofileflags, fdp->fd_ofileflags, i * sizeof(char)); 1290 if (i < NDENTRIES * NDENTRIES) 1291 i = NDENTRIES * NDENTRIES; /* size of inlined bitmaps */ 1292 memcpy(newfdp->fd_himap, fdp->fd_himap, NDHISLOTS(i)*sizeof(uint32_t)); 1293 memcpy(newfdp->fd_lomap, fdp->fd_lomap, NDLOSLOTS(i)*sizeof(uint32_t)); 1294 1295 fpp = fdp->fd_ofiles; 1296 nfpp = newfdp->fd_ofiles; 1297 for (i = 0; i <= lastfile; i++, fpp++, nfpp++) { 1298 if ((*nfpp = *fpp) == NULL) 1299 continue; 1300 1301 if ((*fpp)->f_type == DTYPE_KQUEUE) 1302 /* kq descriptors cannot be copied. */ 1303 fdremove(newfdp, i); 1304 else { 1305 simple_lock(&(*fpp)->f_slock); 1306 (*fpp)->f_count++; 1307 simple_unlock(&(*fpp)->f_slock); 1308 } 1309 } 1310 1311 simple_unlock(&fdp->fd_slock); 1312 1313 newfdp->fd_knlist = NULL; 1314 newfdp->fd_knlistsize = -1; 1315 newfdp->fd_knhash = NULL; 1316 newfdp->fd_knhashmask = 0; 1317 1318 return (newfdp); 1319 } 1320 1321 /* 1322 * Release a filedesc structure. 1323 */ 1324 void 1325 fdfree(struct lwp *l) 1326 { 1327 struct proc *p = l->l_proc; 1328 struct filedesc *fdp; 1329 struct file **fpp, *fp; 1330 int i; 1331 1332 fdp = p->p_fd; 1333 simple_lock(&fdp->fd_slock); 1334 i = --fdp->fd_refcnt; 1335 simple_unlock(&fdp->fd_slock); 1336 if (i > 0) 1337 return; 1338 1339 fpp = fdp->fd_ofiles; 1340 for (i = fdp->fd_lastfile; i >= 0; i--, fpp++) { 1341 fp = *fpp; 1342 if (fp != NULL) { 1343 *fpp = NULL; 1344 simple_lock(&fp->f_slock); 1345 FILE_USE(fp); 1346 if ((fdp->fd_lastfile - i) < fdp->fd_knlistsize) 1347 knote_fdclose(l, fdp->fd_lastfile - i); 1348 (void) closef(fp, l); 1349 } 1350 } 1351 p->p_fd = NULL; 1352 if (fdp->fd_nfiles > NDFILE) 1353 free(fdp->fd_ofiles, M_FILEDESC); 1354 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) { 1355 free(fdp->fd_himap, M_FILEDESC); 1356 free(fdp->fd_lomap, M_FILEDESC); 1357 } 1358 if (fdp->fd_knlist) 1359 free(fdp->fd_knlist, M_KEVENT); 1360 if (fdp->fd_knhash) 1361 hashdone(fdp->fd_knhash, M_KEVENT); 1362 pool_put(&filedesc0_pool, fdp); 1363 } 1364 1365 /* 1366 * Internal form of close. 1367 * Decrement reference count on file structure. 1368 * Note: p may be NULL when closing a file 1369 * that was being passed in a message. 1370 * 1371 * Note: we expect the caller is holding a usecount, and expects us 1372 * to drop it (the caller thinks the file is going away forever). 1373 */ 1374 int 1375 closef(struct file *fp, struct lwp *l) 1376 { 1377 struct proc *p = l ? l->l_proc : NULL; 1378 struct vnode *vp; 1379 struct flock lf; 1380 int error; 1381 1382 if (fp == NULL) 1383 return (0); 1384 1385 /* 1386 * POSIX record locking dictates that any close releases ALL 1387 * locks owned by this process. This is handled by setting 1388 * a flag in the unlock to free ONLY locks obeying POSIX 1389 * semantics, and not to free BSD-style file locks. 1390 * If the descriptor was in a message, POSIX-style locks 1391 * aren't passed with the descriptor. 1392 */ 1393 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) { 1394 lf.l_whence = SEEK_SET; 1395 lf.l_start = 0; 1396 lf.l_len = 0; 1397 lf.l_type = F_UNLCK; 1398 vp = (struct vnode *)fp->f_data; 1399 (void) VOP_ADVLOCK(vp, p, F_UNLCK, &lf, F_POSIX); 1400 } 1401 1402 /* 1403 * If WANTCLOSE is set, then the reference count on the file 1404 * is 0, but there were multiple users of the file. This can 1405 * happen if a filedesc structure is shared by multiple 1406 * processes. 1407 */ 1408 simple_lock(&fp->f_slock); 1409 if (fp->f_iflags & FIF_WANTCLOSE) { 1410 /* 1411 * Another user of the file is already closing, and is 1412 * simply waiting for other users of the file to drain. 1413 * Release our usecount, and wake up the closer if it 1414 * is the only remaining use. 1415 */ 1416 #ifdef DIAGNOSTIC 1417 if (fp->f_count != 0) 1418 panic("closef: wantclose and count != 0"); 1419 if (fp->f_usecount < 2) 1420 panic("closef: wantclose and usecount < 2"); 1421 #endif 1422 if (--fp->f_usecount == 1) 1423 wakeup(&fp->f_usecount); 1424 simple_unlock(&fp->f_slock); 1425 return (0); 1426 } else { 1427 /* 1428 * Decrement the reference count. If we were not the 1429 * last reference, then release our use and just 1430 * return. 1431 */ 1432 if (--fp->f_count > 0) { 1433 #ifdef DIAGNOSTIC 1434 if (fp->f_usecount < 1) 1435 panic("closef: no wantclose and usecount < 1"); 1436 #endif 1437 fp->f_usecount--; 1438 simple_unlock(&fp->f_slock); 1439 return (0); 1440 } 1441 } 1442 1443 /* 1444 * The reference count is now 0. However, there may be 1445 * multiple potential users of this file. This can happen 1446 * if multiple processes shared a single filedesc structure. 1447 * 1448 * Notify these potential users that the file is closing. 1449 * This will prevent them from adding additional uses to 1450 * the file. 1451 */ 1452 fp->f_iflags |= FIF_WANTCLOSE; 1453 1454 /* 1455 * We expect the caller to add a use to the file. So, if we 1456 * are the last user, usecount will be 1. If it is not, we 1457 * must wait for the usecount to drain. When it drains back 1458 * to 1, we will be awakened so that we may proceed with the 1459 * close. 1460 */ 1461 #ifdef DIAGNOSTIC 1462 if (fp->f_usecount < 1) 1463 panic("closef: usecount < 1"); 1464 #endif 1465 while (fp->f_usecount > 1) 1466 (void) ltsleep(&fp->f_usecount, PRIBIO, "closef", 0, 1467 &fp->f_slock); 1468 #ifdef DIAGNOSTIC 1469 if (fp->f_usecount != 1) 1470 panic("closef: usecount != 1"); 1471 #endif 1472 1473 simple_unlock(&fp->f_slock); 1474 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 1475 lf.l_whence = SEEK_SET; 1476 lf.l_start = 0; 1477 lf.l_len = 0; 1478 lf.l_type = F_UNLCK; 1479 vp = (struct vnode *)fp->f_data; 1480 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1481 } 1482 if (fp->f_ops) 1483 error = (*fp->f_ops->fo_close)(fp, l); 1484 else 1485 error = 0; 1486 1487 /* Nothing references the file now, drop the final use (us). */ 1488 fp->f_usecount--; 1489 1490 ffree(fp); 1491 return (error); 1492 } 1493 1494 /* 1495 * Apply an advisory lock on a file descriptor. 1496 * 1497 * Just attempt to get a record lock of the requested type on 1498 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 1499 */ 1500 /* ARGSUSED */ 1501 int 1502 sys_flock(struct lwp *l, void *v, register_t *retval) 1503 { 1504 struct sys_flock_args /* { 1505 syscallarg(int) fd; 1506 syscallarg(int) how; 1507 } */ *uap = v; 1508 int fd, how, error; 1509 struct proc *p; 1510 struct filedesc *fdp; 1511 struct file *fp; 1512 struct vnode *vp; 1513 struct flock lf; 1514 1515 p = l->l_proc; 1516 fd = SCARG(uap, fd); 1517 how = SCARG(uap, how); 1518 fdp = p->p_fd; 1519 error = 0; 1520 1521 if ((fp = fd_getfile(fdp, fd)) == NULL) 1522 return (EBADF); 1523 1524 FILE_USE(fp); 1525 1526 if (fp->f_type != DTYPE_VNODE) { 1527 error = EOPNOTSUPP; 1528 goto out; 1529 } 1530 1531 vp = (struct vnode *)fp->f_data; 1532 lf.l_whence = SEEK_SET; 1533 lf.l_start = 0; 1534 lf.l_len = 0; 1535 if (how & LOCK_UN) { 1536 lf.l_type = F_UNLCK; 1537 fp->f_flag &= ~FHASLOCK; 1538 error = VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1539 goto out; 1540 } 1541 if (how & LOCK_EX) 1542 lf.l_type = F_WRLCK; 1543 else if (how & LOCK_SH) 1544 lf.l_type = F_RDLCK; 1545 else { 1546 error = EINVAL; 1547 goto out; 1548 } 1549 fp->f_flag |= FHASLOCK; 1550 if (how & LOCK_NB) 1551 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf, F_FLOCK); 1552 else 1553 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf, 1554 F_FLOCK|F_WAIT); 1555 out: 1556 FILE_UNUSE(fp, l); 1557 return (error); 1558 } 1559 1560 /* ARGSUSED */ 1561 int 1562 sys_posix_fadvise(struct lwp *l, void *v, register_t *retval) 1563 { 1564 const struct sys_posix_fadvise_args /* { 1565 syscallarg(int) fd; 1566 syscallarg(off_t) offset; 1567 syscallarg(off_t) len; 1568 syscallarg(int) advice; 1569 } */ *uap = v; 1570 const int fd = SCARG(uap, fd); 1571 const int advice = SCARG(uap, advice); 1572 struct proc *p = l->l_proc; 1573 struct file *fp; 1574 int error = 0; 1575 1576 fp = fd_getfile(p->p_fd, fd); 1577 if (fp == NULL) { 1578 error = EBADF; 1579 goto out; 1580 } 1581 FILE_USE(fp); 1582 1583 if (fp->f_type != DTYPE_VNODE) { 1584 if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1585 error = ESPIPE; 1586 } else { 1587 error = EOPNOTSUPP; 1588 } 1589 goto out; 1590 } 1591 1592 switch (advice) { 1593 case POSIX_FADV_NORMAL: 1594 case POSIX_FADV_RANDOM: 1595 case POSIX_FADV_SEQUENTIAL: 1596 KASSERT(POSIX_FADV_NORMAL == UVM_ADV_NORMAL); 1597 KASSERT(POSIX_FADV_RANDOM == UVM_ADV_RANDOM); 1598 KASSERT(POSIX_FADV_SEQUENTIAL == UVM_ADV_SEQUENTIAL); 1599 1600 /* 1601 * we ignore offset and size. 1602 */ 1603 1604 fp->f_advice = advice; 1605 break; 1606 1607 case POSIX_FADV_WILLNEED: 1608 case POSIX_FADV_DONTNEED: 1609 case POSIX_FADV_NOREUSE: 1610 1611 /* 1612 * not implemented yet. 1613 */ 1614 1615 break; 1616 default: 1617 error = EINVAL; 1618 break; 1619 } 1620 out: 1621 if (fp != NULL) { 1622 FILE_UNUSE(fp, l); 1623 } 1624 *retval = error; 1625 return 0; 1626 } 1627 1628 /* 1629 * File Descriptor pseudo-device driver (/dev/fd/). 1630 * 1631 * Opening minor device N dup()s the file (if any) connected to file 1632 * descriptor N belonging to the calling process. Note that this driver 1633 * consists of only the ``open()'' routine, because all subsequent 1634 * references to this file will be direct to the other driver. 1635 */ 1636 /* ARGSUSED */ 1637 static int 1638 filedescopen(dev_t dev, int mode, int type, struct lwp *l) 1639 { 1640 1641 /* 1642 * XXX Kludge: set dupfd to contain the value of the 1643 * the file descriptor being sought for duplication. The error 1644 * return ensures that the vnode for this device will be released 1645 * by vn_open. Open will detect this special error and take the 1646 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 1647 * will simply report the error. 1648 */ 1649 l->l_dupfd = minor(dev); /* XXX */ 1650 return EDUPFD; 1651 } 1652 1653 const struct cdevsw filedesc_cdevsw = { 1654 filedescopen, noclose, noread, nowrite, noioctl, 1655 nostop, notty, nopoll, nommap, nokqfilter, 1656 }; 1657 1658 /* 1659 * Duplicate the specified descriptor to a free descriptor. 1660 * 1661 * 'indx' has been fdalloc'ed (and will be fdremove'ed on error) by the caller. 1662 */ 1663 int 1664 dupfdopen(struct lwp *l, int indx, int dfd, int mode, int error) 1665 { 1666 struct proc *p = l->l_proc; 1667 struct filedesc *fdp; 1668 struct file *wfp; 1669 1670 fdp = p->p_fd; 1671 1672 /* should be cleared by the caller */ 1673 KASSERT(fdp->fd_ofiles[indx] == NULL); 1674 1675 /* 1676 * If the to-be-dup'd fd number is greater than the allowed number 1677 * of file descriptors, or the fd to be dup'd has already been 1678 * closed, reject. 1679 */ 1680 1681 /* 1682 * Note, in the case of indx == dfd, fd_getfile below returns NULL. 1683 */ 1684 if ((wfp = fd_getfile(fdp, dfd)) == NULL) 1685 return (EBADF); 1686 1687 FILE_USE(wfp); 1688 1689 /* 1690 * There are two cases of interest here. 1691 * 1692 * For EDUPFD simply dup (dfd) to file descriptor 1693 * (indx) and return. 1694 * 1695 * For EMOVEFD steal away the file structure from (dfd) and 1696 * store it in (indx). (dfd) is effectively closed by 1697 * this operation. 1698 * 1699 * Any other error code is just returned. 1700 */ 1701 switch (error) { 1702 case EDUPFD: 1703 /* 1704 * Check that the mode the file is being opened for is a 1705 * subset of the mode of the existing descriptor. 1706 */ 1707 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 1708 FILE_UNUSE(wfp, l); 1709 return (EACCES); 1710 } 1711 simple_lock(&fdp->fd_slock); 1712 fdp->fd_ofiles[indx] = wfp; 1713 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1714 simple_unlock(&fdp->fd_slock); 1715 simple_lock(&wfp->f_slock); 1716 wfp->f_count++; 1717 /* 'indx' has been fd_used'ed by caller */ 1718 FILE_UNUSE_HAVELOCK(wfp, l); 1719 return (0); 1720 1721 case EMOVEFD: 1722 /* 1723 * Steal away the file pointer from dfd, and stuff it into indx. 1724 */ 1725 simple_lock(&fdp->fd_slock); 1726 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1727 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1728 fdp->fd_ofiles[dfd] = NULL; 1729 fdp->fd_ofileflags[dfd] = 0; 1730 /* 1731 * Complete the clean up of the filedesc structure by 1732 * recomputing the various hints. 1733 */ 1734 /* 'indx' has been fd_used'ed by caller */ 1735 fd_unused(fdp, dfd); 1736 simple_unlock(&fdp->fd_slock); 1737 FILE_UNUSE(wfp, l); 1738 return (0); 1739 1740 default: 1741 FILE_UNUSE(wfp, l); 1742 return (error); 1743 } 1744 /* NOTREACHED */ 1745 } 1746 1747 /* 1748 * Close any files on exec? 1749 */ 1750 void 1751 fdcloseexec(struct lwp *l) 1752 { 1753 struct proc *p = l->l_proc; 1754 struct filedesc *fdp; 1755 int fd; 1756 1757 fdunshare(l); 1758 cwdunshare(p); 1759 1760 fdp = p->p_fd; 1761 for (fd = 0; fd <= fdp->fd_lastfile; fd++) 1762 if (fdp->fd_ofileflags[fd] & UF_EXCLOSE) 1763 (void) fdrelease(l, fd); 1764 } 1765 1766 /* 1767 * It is unsafe for set[ug]id processes to be started with file 1768 * descriptors 0..2 closed, as these descriptors are given implicit 1769 * significance in the Standard C library. fdcheckstd() will create a 1770 * descriptor referencing /dev/null for each of stdin, stdout, and 1771 * stderr that is not already open. 1772 */ 1773 #define CHECK_UPTO 3 1774 int 1775 fdcheckstd(l) 1776 struct lwp *l; 1777 { 1778 struct proc *p; 1779 struct nameidata nd; 1780 struct filedesc *fdp; 1781 struct file *fp; 1782 struct file *devnullfp = NULL; /* Quell compiler warning */ 1783 struct proc *pp; 1784 register_t retval; 1785 int fd, i, error, flags = FREAD|FWRITE, devnull = -1; 1786 char closed[CHECK_UPTO * 3 + 1], which[3 + 1]; 1787 1788 p = l->l_proc; 1789 closed[0] = '\0'; 1790 if ((fdp = p->p_fd) == NULL) 1791 return (0); 1792 for (i = 0; i < CHECK_UPTO; i++) { 1793 if (fdp->fd_ofiles[i] != NULL) 1794 continue; 1795 snprintf(which, sizeof(which), ",%d", i); 1796 strlcat(closed, which, sizeof(closed)); 1797 if (devnull < 0) { 1798 if ((error = falloc(p, &fp, &fd)) != 0) 1799 return (error); 1800 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/null", 1801 l); 1802 if ((error = vn_open(&nd, flags, 0)) != 0) { 1803 FILE_UNUSE(fp, l); 1804 ffree(fp); 1805 fdremove(p->p_fd, fd); 1806 return (error); 1807 } 1808 fp->f_data = nd.ni_vp; 1809 fp->f_flag = flags; 1810 fp->f_ops = &vnops; 1811 fp->f_type = DTYPE_VNODE; 1812 VOP_UNLOCK(nd.ni_vp, 0); 1813 devnull = fd; 1814 devnullfp = fp; 1815 FILE_SET_MATURE(fp); 1816 } else { 1817 restart: 1818 if ((error = fdalloc(p, 0, &fd)) != 0) { 1819 if (error == ENOSPC) { 1820 fdexpand(p); 1821 goto restart; 1822 } 1823 return (error); 1824 } 1825 1826 simple_lock(&devnullfp->f_slock); 1827 FILE_USE(devnullfp); 1828 /* finishdup() will unuse the descriptors for us */ 1829 if ((error = finishdup(l, devnull, fd, &retval)) != 0) 1830 return (error); 1831 } 1832 } 1833 if (devnullfp) 1834 FILE_UNUSE(devnullfp, l); 1835 if (closed[0] != '\0') { 1836 pp = p->p_pptr; 1837 log(LOG_WARNING, "set{u,g}id pid %d (%s) " 1838 "was invoked by uid %d ppid %d (%s) " 1839 "with fd %s closed\n", 1840 p->p_pid, p->p_comm, pp->p_ucred->cr_uid, 1841 pp->p_pid, pp->p_comm, &closed[1]); 1842 } 1843 return (0); 1844 } 1845 #undef CHECK_UPTO 1846 1847 /* 1848 * Sets descriptor owner. If the owner is a process, 'pgid' 1849 * is set to positive value, process ID. If the owner is process group, 1850 * 'pgid' is set to -pg_id. 1851 */ 1852 int 1853 fsetown(struct proc *p, pid_t *pgid, int cmd, const void *data) 1854 { 1855 int id = *(const int *)data; 1856 int error; 1857 1858 switch (cmd) { 1859 case TIOCSPGRP: 1860 if (id < 0) 1861 return (EINVAL); 1862 id = -id; 1863 break; 1864 default: 1865 break; 1866 } 1867 1868 if (id > 0 && !pfind(id)) 1869 return (ESRCH); 1870 else if (id < 0 && (error = pgid_in_session(p, -id))) 1871 return (error); 1872 1873 *pgid = id; 1874 return (0); 1875 } 1876 1877 /* 1878 * Return descriptor owner information. If the value is positive, 1879 * it's process ID. If it's negative, it's process group ID and 1880 * needs the sign removed before use. 1881 */ 1882 int 1883 fgetown(struct proc *p, pid_t pgid, int cmd, void *data) 1884 { 1885 switch (cmd) { 1886 case TIOCGPGRP: 1887 *(int *)data = -pgid; 1888 break; 1889 default: 1890 *(int *)data = pgid; 1891 break; 1892 } 1893 return (0); 1894 } 1895 1896 /* 1897 * Send signal to descriptor owner, either process or process group. 1898 */ 1899 void 1900 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) 1901 { 1902 struct proc *p1; 1903 ksiginfo_t ksi; 1904 1905 memset(&ksi, 0, sizeof(ksi)); 1906 ksi.ksi_signo = signo; 1907 ksi.ksi_code = code; 1908 ksi.ksi_band = band; 1909 1910 if (pgid > 0 && (p1 = pfind(pgid))) 1911 kpsignal(p1, &ksi, fdescdata); 1912 else if (pgid < 0) 1913 kgsignal(-pgid, &ksi, fdescdata); 1914 } 1915 1916 int 1917 fdclone(struct lwp *l, struct file *fp, int fd, int flag, 1918 const struct fileops *fops, void *data) 1919 { 1920 fp->f_flag = flag; 1921 fp->f_type = DTYPE_MISC; 1922 fp->f_ops = fops; 1923 fp->f_data = data; 1924 1925 l->l_dupfd = fd; 1926 1927 FILE_SET_MATURE(fp); 1928 FILE_UNUSE(fp, l); 1929 return EMOVEFD; 1930 } 1931 1932 /* ARGSUSED */ 1933 int 1934 fnullop_fcntl(struct file *fp, u_int cmd, void *data, struct lwp *l) 1935 { 1936 if (cmd == F_SETFL) 1937 return 0; 1938 1939 return EOPNOTSUPP; 1940 } 1941 1942 /* ARGSUSED */ 1943 int 1944 fnullop_poll(struct file *fp, int which, struct lwp *l) 1945 { 1946 return 0; 1947 } 1948 1949 1950 /* ARGSUSED */ 1951 int 1952 fnullop_kqfilter(struct file *fp, struct knote *kn) 1953 { 1954 1955 return 0; 1956 } 1957 1958 /* ARGSUSED */ 1959 int 1960 fbadop_stat(struct file *fp, struct stat *sb, struct lwp *l) 1961 { 1962 return EOPNOTSUPP; 1963 } 1964