1 /* $NetBSD: kern_descrip.c,v 1.134 2005/06/23 23:15:12 thorpej 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 1.134 2005/06/23 23:15:12 thorpej 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 proc *p, int old, int new, register_t *retval) 217 { 218 struct filedesc *fdp; 219 struct file *fp, *delfp; 220 221 fdp = p->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, p); 245 246 if (delfp != NULL) { 247 simple_lock(&delfp->f_slock); 248 FILE_USE(delfp); 249 if (new < fdp->fd_knlistsize) 250 knote_fdclose(p, new); 251 (void) closef(delfp, p); 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, p); 289 goto restart; 290 } 291 FILE_UNUSE(fp, p); 292 return (error); 293 } 294 295 /* finishdup() will unuse the descriptors for us */ 296 return (finishdup(p, 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, p); 343 goto restart; 344 } 345 FILE_UNUSE(fp, p); 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(p, 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 proc *p, 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 = p->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, p); 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(p, 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, p, 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, p); 503 goto restart; 504 } 505 goto out; 506 } 507 508 /* finishdup() will unuse the descriptors for us */ 509 return (finishdup(p, 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, p); 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, p); 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, p); 541 if (error) { 542 if (i & FNONBLOCK) { 543 tmp = fp->f_flag & FNONBLOCK; 544 (void)(*fp->f_ops->fo_ioctl)(fp, 545 FIONBIO, &tmp, p); 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, p); 554 break; 555 556 case F_GETOWN: 557 error = (*fp->f_ops->fo_ioctl)(fp, FIOGETOWN, retval, p); 558 break; 559 560 case F_SETOWN: 561 tmp = (int)(intptr_t) SCARG(uap, arg); 562 error = (*fp->f_ops->fo_ioctl)(fp, FIOSETOWN, &tmp, p); 563 break; 564 565 case F_SETLKW: 566 flg |= F_WAIT; 567 /* Fall into F_SETLK */ 568 569 case F_SETLK: 570 if (fp->f_type != DTYPE_VNODE) { 571 error = EINVAL; 572 goto out; 573 } 574 vp = (struct vnode *)fp->f_data; 575 /* Copy in the lock structure */ 576 error = copyin(SCARG(uap, arg), &fl, sizeof(fl)); 577 if (error) 578 goto out; 579 if (fl.l_whence == SEEK_CUR) 580 fl.l_start += fp->f_offset; 581 switch (fl.l_type) { 582 case F_RDLCK: 583 if ((fp->f_flag & FREAD) == 0) { 584 error = EBADF; 585 goto out; 586 } 587 p->p_flag |= P_ADVLOCK; 588 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg); 589 goto out; 590 591 case F_WRLCK: 592 if ((fp->f_flag & FWRITE) == 0) { 593 error = EBADF; 594 goto out; 595 } 596 p->p_flag |= P_ADVLOCK; 597 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg); 598 goto out; 599 600 case F_UNLCK: 601 error = VOP_ADVLOCK(vp, p, F_UNLCK, &fl, F_POSIX); 602 goto out; 603 604 default: 605 error = EINVAL; 606 goto out; 607 } 608 609 case F_GETLK: 610 if (fp->f_type != DTYPE_VNODE) { 611 error = EINVAL; 612 goto out; 613 } 614 vp = (struct vnode *)fp->f_data; 615 /* Copy in the lock structure */ 616 error = copyin(SCARG(uap, arg), &fl, sizeof(fl)); 617 if (error) 618 goto out; 619 if (fl.l_whence == SEEK_CUR) 620 fl.l_start += fp->f_offset; 621 if (fl.l_type != F_RDLCK && 622 fl.l_type != F_WRLCK && 623 fl.l_type != F_UNLCK) { 624 error = EINVAL; 625 goto out; 626 } 627 error = VOP_ADVLOCK(vp, p, F_GETLK, &fl, F_POSIX); 628 if (error) 629 goto out; 630 error = copyout(&fl, SCARG(uap, arg), sizeof(fl)); 631 break; 632 633 default: 634 error = EINVAL; 635 } 636 637 out: 638 FILE_UNUSE(fp, p); 639 return (error); 640 } 641 642 void 643 fdremove(struct filedesc *fdp, int fd) 644 { 645 646 simple_lock(&fdp->fd_slock); 647 fdp->fd_ofiles[fd] = NULL; 648 fd_unused(fdp, fd); 649 simple_unlock(&fdp->fd_slock); 650 } 651 652 int 653 fdrelease(struct proc *p, int fd) 654 { 655 struct filedesc *fdp; 656 struct file **fpp, *fp; 657 658 fdp = p->p_fd; 659 simple_lock(&fdp->fd_slock); 660 if (fd < 0 || fd > fdp->fd_lastfile) 661 goto badf; 662 fpp = &fdp->fd_ofiles[fd]; 663 fp = *fpp; 664 if (fp == NULL) 665 goto badf; 666 667 simple_lock(&fp->f_slock); 668 if (!FILE_IS_USABLE(fp)) { 669 simple_unlock(&fp->f_slock); 670 goto badf; 671 } 672 673 FILE_USE(fp); 674 675 *fpp = NULL; 676 fdp->fd_ofileflags[fd] = 0; 677 fd_unused(fdp, fd); 678 simple_unlock(&fdp->fd_slock); 679 if (fd < fdp->fd_knlistsize) 680 knote_fdclose(p, fd); 681 return (closef(fp, p)); 682 683 badf: 684 simple_unlock(&fdp->fd_slock); 685 return (EBADF); 686 } 687 688 /* 689 * Close a file descriptor. 690 */ 691 /* ARGSUSED */ 692 int 693 sys_close(struct lwp *l, void *v, register_t *retval) 694 { 695 struct sys_close_args /* { 696 syscallarg(int) fd; 697 } */ *uap = v; 698 int fd; 699 struct filedesc *fdp; 700 struct proc *p; 701 702 p = l->l_proc; 703 fd = SCARG(uap, fd); 704 fdp = p->p_fd; 705 706 #if 0 707 if (fd_getfile(fdp, fd) == NULL) 708 return (EBADF); 709 #endif 710 711 return (fdrelease(p, fd)); 712 } 713 714 /* 715 * Return status information about a file descriptor. 716 */ 717 /* ARGSUSED */ 718 int 719 sys___fstat13(struct lwp *l, void *v, register_t *retval) 720 { 721 struct sys___fstat13_args /* { 722 syscallarg(int) fd; 723 syscallarg(struct stat *) sb; 724 } */ *uap = v; 725 int fd; 726 struct filedesc *fdp; 727 struct file *fp; 728 struct proc *p; 729 struct stat ub; 730 int error; 731 732 p = l->l_proc; 733 fd = SCARG(uap, fd); 734 fdp = p->p_fd; 735 736 if ((fp = fd_getfile(fdp, fd)) == NULL) 737 return (EBADF); 738 739 FILE_USE(fp); 740 error = (*fp->f_ops->fo_stat)(fp, &ub, p); 741 FILE_UNUSE(fp, p); 742 743 if (error == 0) 744 error = copyout(&ub, SCARG(uap, sb), sizeof(ub)); 745 746 return (error); 747 } 748 749 /* 750 * Return pathconf information about a file descriptor. 751 */ 752 /* ARGSUSED */ 753 int 754 sys_fpathconf(struct lwp *l, void *v, register_t *retval) 755 { 756 struct sys_fpathconf_args /* { 757 syscallarg(int) fd; 758 syscallarg(int) name; 759 } */ *uap = v; 760 int fd; 761 struct filedesc *fdp; 762 struct file *fp; 763 struct proc *p; 764 struct vnode *vp; 765 int error; 766 767 p = l->l_proc; 768 fd = SCARG(uap, fd); 769 fdp = p->p_fd; 770 error = 0; 771 772 if ((fp = fd_getfile(fdp, fd)) == NULL) 773 return (EBADF); 774 775 FILE_USE(fp); 776 777 switch (fp->f_type) { 778 779 case DTYPE_SOCKET: 780 case DTYPE_PIPE: 781 if (SCARG(uap, name) != _PC_PIPE_BUF) 782 error = EINVAL; 783 else 784 *retval = PIPE_BUF; 785 break; 786 787 case DTYPE_VNODE: 788 vp = (struct vnode *)fp->f_data; 789 error = VOP_PATHCONF(vp, SCARG(uap, name), retval); 790 break; 791 792 case DTYPE_KQUEUE: 793 error = EINVAL; 794 break; 795 796 default: 797 error = EOPNOTSUPP; 798 break; 799 } 800 801 FILE_UNUSE(fp, p); 802 return (error); 803 } 804 805 /* 806 * Allocate a file descriptor for the process. 807 */ 808 int fdexpanded; /* XXX: what else uses this? */ 809 810 int 811 fdalloc(struct proc *p, int want, int *result) 812 { 813 struct filedesc *fdp; 814 int i, lim, last, error; 815 u_int off, new; 816 817 fdp = p->p_fd; 818 simple_lock(&fdp->fd_slock); 819 820 /* 821 * Search for a free descriptor starting at the higher 822 * of want or fd_freefile. If that fails, consider 823 * expanding the ofile array. 824 */ 825 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 826 last = min(fdp->fd_nfiles, lim); 827 again: 828 if ((i = want) < fdp->fd_freefile) 829 i = fdp->fd_freefile; 830 off = i >> NDENTRYSHIFT; 831 new = find_next_zero(fdp->fd_himap, off, 832 (last + NDENTRIES - 1) >> NDENTRYSHIFT); 833 if (new != -1) { 834 i = find_next_zero(&fdp->fd_lomap[new], 835 new > off ? 0 : i & NDENTRYMASK, NDENTRIES); 836 if (i == -1) { 837 /* 838 * free file descriptor in this block was 839 * below want, try again with higher want. 840 */ 841 want = (new + 1) << NDENTRYSHIFT; 842 goto again; 843 } 844 i += (new << NDENTRYSHIFT); 845 if (i < last) { 846 if (fdp->fd_ofiles[i] == NULL) { 847 fd_used(fdp, i); 848 if (want <= fdp->fd_freefile) 849 fdp->fd_freefile = i; 850 *result = i; 851 error = 0; 852 goto out; 853 } 854 } 855 } 856 857 /* No space in current array. Expand or let the caller do it. */ 858 error = (fdp->fd_nfiles >= lim) ? EMFILE : ENOSPC; 859 860 out: 861 simple_unlock(&fdp->fd_slock); 862 return (error); 863 } 864 865 void 866 fdexpand(struct proc *p) 867 { 868 struct filedesc *fdp; 869 int i, numfiles, oldnfiles; 870 struct file **newofile; 871 char *newofileflags; 872 uint32_t *newhimap = NULL, *newlomap = NULL; 873 874 fdp = p->p_fd; 875 876 restart: 877 oldnfiles = fdp->fd_nfiles; 878 879 if (oldnfiles < NDEXTENT) 880 numfiles = NDEXTENT; 881 else 882 numfiles = 2 * oldnfiles; 883 884 newofile = malloc(numfiles * OFILESIZE, M_FILEDESC, M_WAITOK); 885 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 886 newhimap = malloc(NDHISLOTS(numfiles) * sizeof(uint32_t), 887 M_FILEDESC, M_WAITOK); 888 newlomap = malloc(NDLOSLOTS(numfiles) * sizeof(uint32_t), 889 M_FILEDESC, M_WAITOK); 890 } 891 892 simple_lock(&fdp->fd_slock); 893 /* lock fdp */ 894 if (fdp->fd_nfiles != oldnfiles) { 895 /* fdp changed; retry */ 896 simple_unlock(&fdp->fd_slock); 897 free(newofile, M_FILEDESC); 898 if (newhimap != NULL) free(newhimap, M_FILEDESC); 899 if (newlomap != NULL) free(newlomap, M_FILEDESC); 900 goto restart; 901 } 902 903 newofileflags = (char *) &newofile[numfiles]; 904 /* 905 * Copy the existing ofile and ofileflags arrays 906 * and zero the new portion of each array. 907 */ 908 memcpy(newofile, fdp->fd_ofiles, 909 (i = sizeof(struct file *) * fdp->fd_nfiles)); 910 memset((char *)newofile + i, 0, 911 numfiles * sizeof(struct file *) - i); 912 memcpy(newofileflags, fdp->fd_ofileflags, 913 (i = sizeof(char) * fdp->fd_nfiles)); 914 memset(newofileflags + i, 0, numfiles * sizeof(char) - i); 915 if (oldnfiles > NDFILE) 916 free(fdp->fd_ofiles, M_FILEDESC); 917 918 if (NDHISLOTS(numfiles) > NDHISLOTS(oldnfiles)) { 919 memcpy(newhimap, fdp->fd_himap, 920 (i = NDHISLOTS(oldnfiles) * sizeof(uint32_t))); 921 memset((char *)newhimap + i, 0, 922 NDHISLOTS(numfiles) * sizeof(uint32_t) - i); 923 924 memcpy(newlomap, fdp->fd_lomap, 925 (i = NDLOSLOTS(oldnfiles) * sizeof(uint32_t))); 926 memset((char *)newlomap + i, 0, 927 NDLOSLOTS(numfiles) * sizeof(uint32_t) - i); 928 929 if (NDHISLOTS(oldnfiles) > NDHISLOTS(NDFILE)) { 930 free(fdp->fd_himap, M_FILEDESC); 931 free(fdp->fd_lomap, M_FILEDESC); 932 } 933 fdp->fd_himap = newhimap; 934 fdp->fd_lomap = newlomap; 935 } 936 937 fdp->fd_ofiles = newofile; 938 fdp->fd_ofileflags = newofileflags; 939 fdp->fd_nfiles = numfiles; 940 941 simple_unlock(&fdp->fd_slock); 942 943 fdexpanded++; 944 } 945 946 /* 947 * Check to see whether n user file descriptors 948 * are available to the process p. 949 */ 950 int 951 fdavail(struct proc *p, int n) 952 { 953 struct filedesc *fdp; 954 struct file **fpp; 955 int i, lim; 956 957 fdp = p->p_fd; 958 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 959 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 960 return (1); 961 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 962 for (i = min(lim,fdp->fd_nfiles) - fdp->fd_freefile; --i >= 0; fpp++) 963 if (*fpp == NULL && --n <= 0) 964 return (1); 965 return (0); 966 } 967 968 /* 969 * Create a new open file structure and allocate 970 * a file descriptor for the process that refers to it. 971 */ 972 int 973 falloc(struct proc *p, struct file **resultfp, int *resultfd) 974 { 975 struct file *fp, *fq; 976 int error, i; 977 978 restart: 979 if ((error = fdalloc(p, 0, &i)) != 0) { 980 if (error == ENOSPC) { 981 fdexpand(p); 982 goto restart; 983 } 984 return (error); 985 } 986 987 fp = pool_get(&file_pool, PR_WAITOK); 988 simple_lock(&filelist_slock); 989 if (nfiles >= maxfiles) { 990 tablefull("file", "increase kern.maxfiles or MAXFILES"); 991 simple_unlock(&filelist_slock); 992 fd_unused(p->p_fd, i); 993 pool_put(&file_pool, fp); 994 return (ENFILE); 995 } 996 /* 997 * Allocate a new file descriptor. 998 * If the process has file descriptor zero open, add to the list 999 * of open files at that point, otherwise put it at the front of 1000 * the list of open files. 1001 */ 1002 nfiles++; 1003 memset(fp, 0, sizeof(struct file)); 1004 fp->f_iflags = FIF_LARVAL; 1005 if ((fq = p->p_fd->fd_ofiles[0]) != NULL) { 1006 LIST_INSERT_AFTER(fq, fp, f_list); 1007 } else { 1008 LIST_INSERT_HEAD(&filehead, fp, f_list); 1009 } 1010 simple_unlock(&filelist_slock); 1011 KDASSERT(p->p_fd->fd_ofiles[i] == NULL); 1012 p->p_fd->fd_ofiles[i] = fp; 1013 simple_lock_init(&fp->f_slock); 1014 fp->f_count = 1; 1015 fp->f_cred = p->p_ucred; 1016 crhold(fp->f_cred); 1017 if (resultfp) { 1018 fp->f_usecount = 1; 1019 *resultfp = fp; 1020 } 1021 if (resultfd) 1022 *resultfd = i; 1023 return (0); 1024 } 1025 1026 /* 1027 * Free a file descriptor. 1028 */ 1029 void 1030 ffree(struct file *fp) 1031 { 1032 1033 #ifdef DIAGNOSTIC 1034 if (fp->f_usecount) 1035 panic("ffree"); 1036 #endif 1037 1038 simple_lock(&filelist_slock); 1039 LIST_REMOVE(fp, f_list); 1040 crfree(fp->f_cred); 1041 #ifdef DIAGNOSTIC 1042 fp->f_count = 0; /* What's the point? */ 1043 #endif 1044 nfiles--; 1045 simple_unlock(&filelist_slock); 1046 pool_put(&file_pool, fp); 1047 } 1048 1049 /* 1050 * Create an initial cwdinfo structure, using the same current and root 1051 * directories as p. 1052 */ 1053 struct cwdinfo * 1054 cwdinit(struct proc *p) 1055 { 1056 struct cwdinfo *cwdi; 1057 1058 cwdi = pool_get(&cwdi_pool, PR_WAITOK); 1059 1060 simple_lock_init(&cwdi->cwdi_slock); 1061 cwdi->cwdi_cdir = p->p_cwdi->cwdi_cdir; 1062 if (cwdi->cwdi_cdir) 1063 VREF(cwdi->cwdi_cdir); 1064 cwdi->cwdi_rdir = p->p_cwdi->cwdi_rdir; 1065 if (cwdi->cwdi_rdir) 1066 VREF(cwdi->cwdi_rdir); 1067 cwdi->cwdi_cmask = p->p_cwdi->cwdi_cmask; 1068 cwdi->cwdi_refcnt = 1; 1069 1070 return (cwdi); 1071 } 1072 1073 /* 1074 * Make p2 share p1's cwdinfo. 1075 */ 1076 void 1077 cwdshare(struct proc *p1, struct proc *p2) 1078 { 1079 struct cwdinfo *cwdi = p1->p_cwdi; 1080 1081 simple_lock(&cwdi->cwdi_slock); 1082 cwdi->cwdi_refcnt++; 1083 simple_unlock(&cwdi->cwdi_slock); 1084 p2->p_cwdi = cwdi; 1085 } 1086 1087 /* 1088 * Make this process not share its cwdinfo structure, maintaining 1089 * all cwdinfo state. 1090 */ 1091 void 1092 cwdunshare(struct proc *p) 1093 { 1094 struct cwdinfo *oldcwdi, *newcwdi; 1095 1096 if (p->p_cwdi->cwdi_refcnt == 1) 1097 return; 1098 1099 newcwdi = cwdinit(p); 1100 oldcwdi = p->p_cwdi; 1101 p->p_cwdi = newcwdi; 1102 cwdfree(oldcwdi); 1103 } 1104 1105 /* 1106 * Release a cwdinfo structure. 1107 */ 1108 void 1109 cwdfree(struct cwdinfo *cwdi) 1110 { 1111 int n; 1112 1113 simple_lock(&cwdi->cwdi_slock); 1114 n = --cwdi->cwdi_refcnt; 1115 simple_unlock(&cwdi->cwdi_slock); 1116 if (n > 0) 1117 return; 1118 1119 vrele(cwdi->cwdi_cdir); 1120 if (cwdi->cwdi_rdir) 1121 vrele(cwdi->cwdi_rdir); 1122 pool_put(&cwdi_pool, cwdi); 1123 } 1124 1125 /* 1126 * Create an initial filedesc structure, using the same current and root 1127 * directories as p. 1128 */ 1129 struct filedesc * 1130 fdinit(struct proc *p) 1131 { 1132 struct filedesc0 *newfdp; 1133 1134 newfdp = pool_get(&filedesc0_pool, PR_WAITOK); 1135 memset(newfdp, 0, sizeof(struct filedesc0)); 1136 1137 fdinit1(newfdp); 1138 1139 return (&newfdp->fd_fd); 1140 } 1141 1142 /* 1143 * Initialize a file descriptor table. 1144 */ 1145 void 1146 fdinit1(struct filedesc0 *newfdp) 1147 { 1148 1149 newfdp->fd_fd.fd_refcnt = 1; 1150 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1151 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1152 newfdp->fd_fd.fd_nfiles = NDFILE; 1153 newfdp->fd_fd.fd_knlistsize = -1; 1154 newfdp->fd_fd.fd_himap = newfdp->fd_dhimap; 1155 newfdp->fd_fd.fd_lomap = newfdp->fd_dlomap; 1156 newfdp->fd_fd.fd_lastfile = -1; 1157 simple_lock_init(&newfdp->fd_fd.fd_slock); 1158 } 1159 1160 /* 1161 * Make p2 share p1's filedesc structure. 1162 */ 1163 void 1164 fdshare(struct proc *p1, struct proc *p2) 1165 { 1166 struct filedesc *fdp = p1->p_fd; 1167 1168 simple_lock(&fdp->fd_slock); 1169 p2->p_fd = fdp; 1170 fdp->fd_refcnt++; 1171 simple_unlock(&fdp->fd_slock); 1172 } 1173 1174 /* 1175 * Make this process not share its filedesc structure, maintaining 1176 * all file descriptor state. 1177 */ 1178 void 1179 fdunshare(struct proc *p) 1180 { 1181 struct filedesc *newfd; 1182 1183 if (p->p_fd->fd_refcnt == 1) 1184 return; 1185 1186 newfd = fdcopy(p); 1187 fdfree(p); 1188 p->p_fd = newfd; 1189 } 1190 1191 /* 1192 * Clear a process's fd table. 1193 */ 1194 void 1195 fdclear(struct proc *p) 1196 { 1197 struct filedesc *newfd; 1198 1199 newfd = fdinit(p); 1200 fdfree(p); 1201 p->p_fd = newfd; 1202 } 1203 1204 /* 1205 * Copy a filedesc structure. 1206 */ 1207 struct filedesc * 1208 fdcopy(struct proc *p) 1209 { 1210 struct filedesc *newfdp, *fdp; 1211 struct file **fpp, **nfpp; 1212 int i, numfiles, lastfile; 1213 1214 fdp = p->p_fd; 1215 newfdp = pool_get(&filedesc0_pool, PR_WAITOK); 1216 newfdp->fd_refcnt = 1; 1217 simple_lock_init(&newfdp->fd_slock); 1218 1219 restart: 1220 numfiles = fdp->fd_nfiles; 1221 lastfile = fdp->fd_lastfile; 1222 1223 /* 1224 * If the number of open files fits in the internal arrays 1225 * of the open file structure, use them, otherwise allocate 1226 * additional memory for the number of descriptors currently 1227 * in use. 1228 */ 1229 if (lastfile < NDFILE) { 1230 i = NDFILE; 1231 } else { 1232 /* 1233 * Compute the smallest multiple of NDEXTENT needed 1234 * for the file descriptors currently in use, 1235 * allowing the table to shrink. 1236 */ 1237 i = numfiles; 1238 while (i >= 2 * NDEXTENT && i > lastfile * 2) 1239 i /= 2; 1240 newfdp->fd_ofiles = malloc(i * OFILESIZE, M_FILEDESC, M_WAITOK); 1241 } 1242 if (NDHISLOTS(i) > NDHISLOTS(NDFILE)) { 1243 newfdp->fd_himap = malloc(NDHISLOTS(i) * sizeof(uint32_t), 1244 M_FILEDESC, M_WAITOK); 1245 newfdp->fd_lomap = malloc(NDLOSLOTS(i) * sizeof(uint32_t), 1246 M_FILEDESC, M_WAITOK); 1247 } 1248 1249 simple_lock(&fdp->fd_slock); 1250 if (numfiles != fdp->fd_nfiles || lastfile != fdp->fd_lastfile) { 1251 simple_unlock(&fdp->fd_slock); 1252 if (i > NDFILE) 1253 free(newfdp->fd_ofiles, M_FILEDESC); 1254 if (NDHISLOTS(i) > NDHISLOTS(NDFILE)) { 1255 free(newfdp->fd_himap, M_FILEDESC); 1256 free(newfdp->fd_lomap, M_FILEDESC); 1257 } 1258 goto restart; 1259 } 1260 1261 if (lastfile < NDFILE) { 1262 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 1263 newfdp->fd_ofileflags = 1264 ((struct filedesc0 *) newfdp)->fd_dfileflags; 1265 } else { 1266 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1267 } 1268 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) { 1269 newfdp->fd_himap = 1270 ((struct filedesc0 *) newfdp)->fd_dhimap; 1271 newfdp->fd_lomap = 1272 ((struct filedesc0 *) newfdp)->fd_dlomap; 1273 } 1274 1275 newfdp->fd_nfiles = i; 1276 newfdp->fd_lastfile = lastfile; 1277 newfdp->fd_freefile = fdp->fd_freefile; 1278 1279 /* Clear the entries that will not be copied over. 1280 * Avoid calling memset with 0 size (i.e. when 1281 * lastfile == i-1 */ 1282 if (lastfile < (i-1)) 1283 memset(newfdp->fd_ofiles + lastfile + 1, 0, 1284 (i - lastfile - 1) * sizeof(struct file **)); 1285 memcpy(newfdp->fd_ofileflags, fdp->fd_ofileflags, i * sizeof(char)); 1286 if (i < NDENTRIES * NDENTRIES) 1287 i = NDENTRIES * NDENTRIES; /* size of inlined bitmaps */ 1288 memcpy(newfdp->fd_himap, fdp->fd_himap, NDHISLOTS(i)*sizeof(uint32_t)); 1289 memcpy(newfdp->fd_lomap, fdp->fd_lomap, NDLOSLOTS(i)*sizeof(uint32_t)); 1290 1291 fpp = fdp->fd_ofiles; 1292 nfpp = newfdp->fd_ofiles; 1293 for (i = 0; i <= lastfile; i++, fpp++, nfpp++) { 1294 if ((*nfpp = *fpp) == NULL) 1295 continue; 1296 1297 if ((*fpp)->f_type == DTYPE_KQUEUE) 1298 /* kq descriptors cannot be copied. */ 1299 fdremove(newfdp, i); 1300 else { 1301 simple_lock(&(*fpp)->f_slock); 1302 (*fpp)->f_count++; 1303 simple_unlock(&(*fpp)->f_slock); 1304 } 1305 } 1306 1307 simple_unlock(&fdp->fd_slock); 1308 1309 newfdp->fd_knlist = NULL; 1310 newfdp->fd_knlistsize = -1; 1311 newfdp->fd_knhash = NULL; 1312 newfdp->fd_knhashmask = 0; 1313 1314 return (newfdp); 1315 } 1316 1317 /* 1318 * Release a filedesc structure. 1319 */ 1320 void 1321 fdfree(struct proc *p) 1322 { 1323 struct filedesc *fdp; 1324 struct file **fpp, *fp; 1325 int i; 1326 1327 fdp = p->p_fd; 1328 simple_lock(&fdp->fd_slock); 1329 i = --fdp->fd_refcnt; 1330 simple_unlock(&fdp->fd_slock); 1331 if (i > 0) 1332 return; 1333 1334 fpp = fdp->fd_ofiles; 1335 for (i = fdp->fd_lastfile; i >= 0; i--, fpp++) { 1336 fp = *fpp; 1337 if (fp != NULL) { 1338 *fpp = NULL; 1339 simple_lock(&fp->f_slock); 1340 FILE_USE(fp); 1341 if ((fdp->fd_lastfile - i) < fdp->fd_knlistsize) 1342 knote_fdclose(p, fdp->fd_lastfile - i); 1343 (void) closef(fp, p); 1344 } 1345 } 1346 p->p_fd = NULL; 1347 if (fdp->fd_nfiles > NDFILE) 1348 free(fdp->fd_ofiles, M_FILEDESC); 1349 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) { 1350 free(fdp->fd_himap, M_FILEDESC); 1351 free(fdp->fd_lomap, M_FILEDESC); 1352 } 1353 if (fdp->fd_knlist) 1354 free(fdp->fd_knlist, M_KEVENT); 1355 if (fdp->fd_knhash) 1356 hashdone(fdp->fd_knhash, M_KEVENT); 1357 pool_put(&filedesc0_pool, fdp); 1358 } 1359 1360 /* 1361 * Internal form of close. 1362 * Decrement reference count on file structure. 1363 * Note: p may be NULL when closing a file 1364 * that was being passed in a message. 1365 * 1366 * Note: we expect the caller is holding a usecount, and expects us 1367 * to drop it (the caller thinks the file is going away forever). 1368 */ 1369 int 1370 closef(struct file *fp, struct proc *p) 1371 { 1372 struct vnode *vp; 1373 struct flock lf; 1374 int error; 1375 1376 if (fp == NULL) 1377 return (0); 1378 1379 /* 1380 * POSIX record locking dictates that any close releases ALL 1381 * locks owned by this process. This is handled by setting 1382 * a flag in the unlock to free ONLY locks obeying POSIX 1383 * semantics, and not to free BSD-style file locks. 1384 * If the descriptor was in a message, POSIX-style locks 1385 * aren't passed with the descriptor. 1386 */ 1387 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) { 1388 lf.l_whence = SEEK_SET; 1389 lf.l_start = 0; 1390 lf.l_len = 0; 1391 lf.l_type = F_UNLCK; 1392 vp = (struct vnode *)fp->f_data; 1393 (void) VOP_ADVLOCK(vp, p, F_UNLCK, &lf, F_POSIX); 1394 } 1395 1396 /* 1397 * If WANTCLOSE is set, then the reference count on the file 1398 * is 0, but there were multiple users of the file. This can 1399 * happen if a filedesc structure is shared by multiple 1400 * processes. 1401 */ 1402 simple_lock(&fp->f_slock); 1403 if (fp->f_iflags & FIF_WANTCLOSE) { 1404 /* 1405 * Another user of the file is already closing, and is 1406 * simply waiting for other users of the file to drain. 1407 * Release our usecount, and wake up the closer if it 1408 * is the only remaining use. 1409 */ 1410 #ifdef DIAGNOSTIC 1411 if (fp->f_count != 0) 1412 panic("closef: wantclose and count != 0"); 1413 if (fp->f_usecount < 2) 1414 panic("closef: wantclose and usecount < 2"); 1415 #endif 1416 if (--fp->f_usecount == 1) 1417 wakeup(&fp->f_usecount); 1418 simple_unlock(&fp->f_slock); 1419 return (0); 1420 } else { 1421 /* 1422 * Decrement the reference count. If we were not the 1423 * last reference, then release our use and just 1424 * return. 1425 */ 1426 if (--fp->f_count > 0) { 1427 #ifdef DIAGNOSTIC 1428 if (fp->f_usecount < 1) 1429 panic("closef: no wantclose and usecount < 1"); 1430 #endif 1431 fp->f_usecount--; 1432 simple_unlock(&fp->f_slock); 1433 return (0); 1434 } 1435 } 1436 1437 /* 1438 * The reference count is now 0. However, there may be 1439 * multiple potential users of this file. This can happen 1440 * if multiple processes shared a single filedesc structure. 1441 * 1442 * Notify these potential users that the file is closing. 1443 * This will prevent them from adding additional uses to 1444 * the file. 1445 */ 1446 fp->f_iflags |= FIF_WANTCLOSE; 1447 1448 /* 1449 * We expect the caller to add a use to the file. So, if we 1450 * are the last user, usecount will be 1. If it is not, we 1451 * must wait for the usecount to drain. When it drains back 1452 * to 1, we will be awakened so that we may proceed with the 1453 * close. 1454 */ 1455 #ifdef DIAGNOSTIC 1456 if (fp->f_usecount < 1) 1457 panic("closef: usecount < 1"); 1458 #endif 1459 while (fp->f_usecount > 1) 1460 (void) ltsleep(&fp->f_usecount, PRIBIO, "closef", 0, 1461 &fp->f_slock); 1462 #ifdef DIAGNOSTIC 1463 if (fp->f_usecount != 1) 1464 panic("closef: usecount != 1"); 1465 #endif 1466 1467 simple_unlock(&fp->f_slock); 1468 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 1469 lf.l_whence = SEEK_SET; 1470 lf.l_start = 0; 1471 lf.l_len = 0; 1472 lf.l_type = F_UNLCK; 1473 vp = (struct vnode *)fp->f_data; 1474 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1475 } 1476 if (fp->f_ops) 1477 error = (*fp->f_ops->fo_close)(fp, p); 1478 else 1479 error = 0; 1480 1481 /* Nothing references the file now, drop the final use (us). */ 1482 fp->f_usecount--; 1483 1484 ffree(fp); 1485 return (error); 1486 } 1487 1488 /* 1489 * Apply an advisory lock on a file descriptor. 1490 * 1491 * Just attempt to get a record lock of the requested type on 1492 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 1493 */ 1494 /* ARGSUSED */ 1495 int 1496 sys_flock(struct lwp *l, void *v, register_t *retval) 1497 { 1498 struct sys_flock_args /* { 1499 syscallarg(int) fd; 1500 syscallarg(int) how; 1501 } */ *uap = v; 1502 int fd, how, error; 1503 struct proc *p; 1504 struct filedesc *fdp; 1505 struct file *fp; 1506 struct vnode *vp; 1507 struct flock lf; 1508 1509 p = l->l_proc; 1510 fd = SCARG(uap, fd); 1511 how = SCARG(uap, how); 1512 fdp = p->p_fd; 1513 error = 0; 1514 1515 if ((fp = fd_getfile(fdp, fd)) == NULL) 1516 return (EBADF); 1517 1518 FILE_USE(fp); 1519 1520 if (fp->f_type != DTYPE_VNODE) { 1521 error = EOPNOTSUPP; 1522 goto out; 1523 } 1524 1525 vp = (struct vnode *)fp->f_data; 1526 lf.l_whence = SEEK_SET; 1527 lf.l_start = 0; 1528 lf.l_len = 0; 1529 if (how & LOCK_UN) { 1530 lf.l_type = F_UNLCK; 1531 fp->f_flag &= ~FHASLOCK; 1532 error = VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1533 goto out; 1534 } 1535 if (how & LOCK_EX) 1536 lf.l_type = F_WRLCK; 1537 else if (how & LOCK_SH) 1538 lf.l_type = F_RDLCK; 1539 else { 1540 error = EINVAL; 1541 goto out; 1542 } 1543 fp->f_flag |= FHASLOCK; 1544 if (how & LOCK_NB) 1545 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf, F_FLOCK); 1546 else 1547 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf, 1548 F_FLOCK|F_WAIT); 1549 out: 1550 FILE_UNUSE(fp, p); 1551 return (error); 1552 } 1553 1554 /* 1555 * File Descriptor pseudo-device driver (/dev/fd/). 1556 * 1557 * Opening minor device N dup()s the file (if any) connected to file 1558 * descriptor N belonging to the calling process. Note that this driver 1559 * consists of only the ``open()'' routine, because all subsequent 1560 * references to this file will be direct to the other driver. 1561 */ 1562 /* ARGSUSED */ 1563 static int 1564 filedescopen(dev_t dev, int mode, int type, struct proc *p) 1565 { 1566 1567 /* 1568 * XXX Kludge: set dupfd to contain the value of the 1569 * the file descriptor being sought for duplication. The error 1570 * return ensures that the vnode for this device will be released 1571 * by vn_open. Open will detect this special error and take the 1572 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 1573 * will simply report the error. 1574 */ 1575 curlwp->l_dupfd = minor(dev); /* XXX */ 1576 return EDUPFD; 1577 } 1578 1579 const struct cdevsw filedesc_cdevsw = { 1580 filedescopen, noclose, noread, nowrite, noioctl, 1581 nostop, notty, nopoll, nommap, nokqfilter, 1582 }; 1583 1584 /* 1585 * Duplicate the specified descriptor to a free descriptor. 1586 * 1587 * 'indx' has been fdalloc'ed (and will be fdremove'ed on error) by the caller. 1588 */ 1589 int 1590 dupfdopen(struct proc *p, int indx, int dfd, int mode, int error) 1591 { 1592 struct filedesc *fdp; 1593 struct file *wfp; 1594 1595 fdp = p->p_fd; 1596 1597 /* should be cleared by the caller */ 1598 KASSERT(fdp->fd_ofiles[indx] == NULL); 1599 1600 /* 1601 * If the to-be-dup'd fd number is greater than the allowed number 1602 * of file descriptors, or the fd to be dup'd has already been 1603 * closed, reject. 1604 */ 1605 1606 /* 1607 * Note, in the case of indx == dfd, fd_getfile below returns NULL. 1608 */ 1609 if ((wfp = fd_getfile(fdp, dfd)) == NULL) 1610 return (EBADF); 1611 1612 FILE_USE(wfp); 1613 1614 /* 1615 * There are two cases of interest here. 1616 * 1617 * For EDUPFD simply dup (dfd) to file descriptor 1618 * (indx) and return. 1619 * 1620 * For EMOVEFD steal away the file structure from (dfd) and 1621 * store it in (indx). (dfd) is effectively closed by 1622 * this operation. 1623 * 1624 * Any other error code is just returned. 1625 */ 1626 switch (error) { 1627 case EDUPFD: 1628 /* 1629 * Check that the mode the file is being opened for is a 1630 * subset of the mode of the existing descriptor. 1631 */ 1632 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 1633 FILE_UNUSE(wfp, p); 1634 return (EACCES); 1635 } 1636 simple_lock(&fdp->fd_slock); 1637 fdp->fd_ofiles[indx] = wfp; 1638 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1639 simple_unlock(&fdp->fd_slock); 1640 simple_lock(&wfp->f_slock); 1641 wfp->f_count++; 1642 /* 'indx' has been fd_used'ed by caller */ 1643 FILE_UNUSE_HAVELOCK(wfp, p); 1644 return (0); 1645 1646 case EMOVEFD: 1647 /* 1648 * Steal away the file pointer from dfd, and stuff it into indx. 1649 */ 1650 simple_lock(&fdp->fd_slock); 1651 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1652 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1653 fdp->fd_ofiles[dfd] = NULL; 1654 fdp->fd_ofileflags[dfd] = 0; 1655 /* 1656 * Complete the clean up of the filedesc structure by 1657 * recomputing the various hints. 1658 */ 1659 /* 'indx' has been fd_used'ed by caller */ 1660 fd_unused(fdp, dfd); 1661 simple_unlock(&fdp->fd_slock); 1662 FILE_UNUSE(wfp, p); 1663 return (0); 1664 1665 default: 1666 FILE_UNUSE(wfp, p); 1667 return (error); 1668 } 1669 /* NOTREACHED */ 1670 } 1671 1672 /* 1673 * Close any files on exec? 1674 */ 1675 void 1676 fdcloseexec(struct proc *p) 1677 { 1678 struct filedesc *fdp; 1679 int fd; 1680 1681 fdunshare(p); 1682 cwdunshare(p); 1683 1684 fdp = p->p_fd; 1685 for (fd = 0; fd <= fdp->fd_lastfile; fd++) 1686 if (fdp->fd_ofileflags[fd] & UF_EXCLOSE) 1687 (void) fdrelease(p, fd); 1688 } 1689 1690 /* 1691 * It is unsafe for set[ug]id processes to be started with file 1692 * descriptors 0..2 closed, as these descriptors are given implicit 1693 * significance in the Standard C library. fdcheckstd() will create a 1694 * descriptor referencing /dev/null for each of stdin, stdout, and 1695 * stderr that is not already open. 1696 */ 1697 #define CHECK_UPTO 3 1698 int 1699 fdcheckstd(p) 1700 struct proc *p; 1701 { 1702 struct nameidata nd; 1703 struct filedesc *fdp; 1704 struct file *fp; 1705 struct file *devnullfp = NULL; /* Quell compiler warning */ 1706 struct proc *pp; 1707 register_t retval; 1708 int fd, i, error, flags = FREAD|FWRITE, devnull = -1; 1709 char closed[CHECK_UPTO * 3 + 1], which[3 + 1]; 1710 1711 closed[0] = '\0'; 1712 if ((fdp = p->p_fd) == NULL) 1713 return (0); 1714 for (i = 0; i < CHECK_UPTO; i++) { 1715 if (fdp->fd_ofiles[i] != NULL) 1716 continue; 1717 snprintf(which, sizeof(which), ",%d", i); 1718 strlcat(closed, which, sizeof(closed)); 1719 if (devnull < 0) { 1720 if ((error = falloc(p, &fp, &fd)) != 0) 1721 return (error); 1722 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/null", 1723 p); 1724 if ((error = vn_open(&nd, flags, 0)) != 0) { 1725 FILE_UNUSE(fp, p); 1726 ffree(fp); 1727 fdremove(p->p_fd, fd); 1728 return (error); 1729 } 1730 fp->f_data = nd.ni_vp; 1731 fp->f_flag = flags; 1732 fp->f_ops = &vnops; 1733 fp->f_type = DTYPE_VNODE; 1734 VOP_UNLOCK(nd.ni_vp, 0); 1735 devnull = fd; 1736 devnullfp = fp; 1737 FILE_SET_MATURE(fp); 1738 } else { 1739 restart: 1740 if ((error = fdalloc(p, 0, &fd)) != 0) { 1741 if (error == ENOSPC) { 1742 fdexpand(p); 1743 goto restart; 1744 } 1745 return (error); 1746 } 1747 1748 simple_lock(&devnullfp->f_slock); 1749 FILE_USE(devnullfp); 1750 /* finishdup() will unuse the descriptors for us */ 1751 if ((error = finishdup(p, devnull, fd, &retval)) != 0) 1752 return (error); 1753 } 1754 } 1755 if (devnullfp) 1756 FILE_UNUSE(devnullfp, p); 1757 if (closed[0] != '\0') { 1758 pp = p->p_pptr; 1759 log(LOG_WARNING, "set{u,g}id pid %d (%s) " 1760 "was invoked by uid %d ppid %d (%s) " 1761 "with fd %s closed\n", 1762 p->p_pid, p->p_comm, pp->p_ucred->cr_uid, 1763 pp->p_pid, pp->p_comm, &closed[1]); 1764 } 1765 return (0); 1766 } 1767 #undef CHECK_UPTO 1768 1769 /* 1770 * Sets descriptor owner. If the owner is a process, 'pgid' 1771 * is set to positive value, process ID. If the owner is process group, 1772 * 'pgid' is set to -pg_id. 1773 */ 1774 int 1775 fsetown(struct proc *p, pid_t *pgid, int cmd, const void *data) 1776 { 1777 int id = *(const int *)data; 1778 int error; 1779 1780 switch (cmd) { 1781 case TIOCSPGRP: 1782 if (id < 0) 1783 return (EINVAL); 1784 id = -id; 1785 break; 1786 default: 1787 break; 1788 } 1789 1790 if (id > 0 && !pfind(id)) 1791 return (ESRCH); 1792 else if (id < 0 && (error = pgid_in_session(p, -id))) 1793 return (error); 1794 1795 *pgid = id; 1796 return (0); 1797 } 1798 1799 /* 1800 * Return descriptor owner information. If the value is positive, 1801 * it's process ID. If it's negative, it's process group ID and 1802 * needs the sign removed before use. 1803 */ 1804 int 1805 fgetown(struct proc *p, pid_t pgid, int cmd, void *data) 1806 { 1807 switch (cmd) { 1808 case TIOCGPGRP: 1809 *(int *)data = -pgid; 1810 break; 1811 default: 1812 *(int *)data = pgid; 1813 break; 1814 } 1815 return (0); 1816 } 1817 1818 /* 1819 * Send signal to descriptor owner, either process or process group. 1820 */ 1821 void 1822 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata) 1823 { 1824 struct proc *p1; 1825 ksiginfo_t ksi; 1826 1827 memset(&ksi, 0, sizeof(ksi)); 1828 ksi.ksi_signo = signo; 1829 ksi.ksi_code = code; 1830 ksi.ksi_band = band; 1831 1832 if (pgid > 0 && (p1 = pfind(pgid))) 1833 kpsignal(p1, &ksi, fdescdata); 1834 else if (pgid < 0) 1835 kgsignal(-pgid, &ksi, fdescdata); 1836 } 1837 1838 int 1839 fdclone(struct proc *p, struct file *fp, int fd, int flag, 1840 const struct fileops *fops, void *data) 1841 { 1842 fp->f_flag = flag; 1843 fp->f_type = DTYPE_MISC; 1844 fp->f_ops = fops; 1845 fp->f_data = data; 1846 1847 curlwp->l_dupfd = fd; 1848 1849 FILE_SET_MATURE(fp); 1850 FILE_UNUSE(fp, p); 1851 return EMOVEFD; 1852 } 1853 1854 /* ARGSUSED */ 1855 int 1856 fnullop_fcntl(struct file *fp, u_int cmd, void *data, struct proc *p) 1857 { 1858 if (cmd == F_SETFL) 1859 return 0; 1860 1861 return EOPNOTSUPP; 1862 } 1863 1864 /* ARGSUSED */ 1865 int 1866 fnullop_poll(struct file *fp, int which, struct proc *p) 1867 { 1868 return 0; 1869 } 1870 1871 1872 /* ARGSUSED */ 1873 int 1874 fnullop_kqfilter(struct file *fp, struct knote *kn) 1875 { 1876 1877 return 0; 1878 } 1879 1880 /* ARGSUSED */ 1881 int 1882 fbadop_stat(struct file *fp, struct stat *sb, struct proc *p) 1883 { 1884 return EOPNOTSUPP; 1885 } 1886