kern_descrip.c revision 175294
1/*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/kern/kern_descrip.c 175294 2008-01-13 14:44:15Z attilio $"); 39 40#include "opt_compat.h" 41#include "opt_ddb.h" 42 43#include <sys/param.h> 44#include <sys/systm.h> 45 46#include <sys/conf.h> 47#include <sys/domain.h> 48#include <sys/fcntl.h> 49#include <sys/file.h> 50#include <sys/filedesc.h> 51#include <sys/filio.h> 52#include <sys/jail.h> 53#include <sys/kernel.h> 54#include <sys/limits.h> 55#include <sys/lock.h> 56#include <sys/malloc.h> 57#include <sys/mount.h> 58#include <sys/mqueue.h> 59#include <sys/mutex.h> 60#include <sys/namei.h> 61#include <sys/priv.h> 62#include <sys/proc.h> 63#include <sys/protosw.h> 64#include <sys/resourcevar.h> 65#include <sys/signalvar.h> 66#include <sys/socketvar.h> 67#include <sys/stat.h> 68#include <sys/sx.h> 69#include <sys/syscallsubr.h> 70#include <sys/sysctl.h> 71#include <sys/sysproto.h> 72#include <sys/unistd.h> 73#include <sys/user.h> 74#include <sys/vnode.h> 75 76#include <security/audit/audit.h> 77 78#include <vm/uma.h> 79 80#include <ddb/ddb.h> 81 82static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 83static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 84 "file desc to leader structures"); 85static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 86 87static uma_zone_t file_zone; 88 89 90/* How to treat 'new' parameter when allocating a fd for do_dup(). */ 91enum dup_type { DUP_VARIABLE, DUP_FIXED }; 92 93static int do_dup(struct thread *td, enum dup_type type, int old, int new, 94 register_t *retval); 95static int fd_first_free(struct filedesc *, int, int); 96static int fd_last_used(struct filedesc *, int, int); 97static void fdgrowtable(struct filedesc *, int); 98static void fdunused(struct filedesc *fdp, int fd); 99static void fdused(struct filedesc *fdp, int fd); 100 101/* 102 * A process is initially started out with NDFILE descriptors stored within 103 * this structure, selected to be enough for typical applications based on 104 * the historical limit of 20 open files (and the usage of descriptors by 105 * shells). If these descriptors are exhausted, a larger descriptor table 106 * may be allocated, up to a process' resource limit; the internal arrays 107 * are then unused. 108 */ 109#define NDFILE 20 110#define NDSLOTSIZE sizeof(NDSLOTTYPE) 111#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 112#define NDSLOT(x) ((x) / NDENTRIES) 113#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 114#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 115 116/* 117 * Storage required per open file descriptor. 118 */ 119#define OFILESIZE (sizeof(struct file *) + sizeof(char)) 120 121/* 122 * Basic allocation of descriptors: 123 * one of the above, plus arrays for NDFILE descriptors. 124 */ 125struct filedesc0 { 126 struct filedesc fd_fd; 127 /* 128 * These arrays are used when the number of open files is 129 * <= NDFILE, and are then pointed to by the pointers above. 130 */ 131 struct file *fd_dfiles[NDFILE]; 132 char fd_dfileflags[NDFILE]; 133 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 134}; 135 136/* 137 * Descriptor management. 138 */ 139volatile int openfiles; /* actual number of open files */ 140struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 141void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 142 143/* A mutex to protect the association between a proc and filedesc. */ 144static struct mtx fdesc_mtx; 145 146/* 147 * Find the first zero bit in the given bitmap, starting at low and not 148 * exceeding size - 1. 149 */ 150static int 151fd_first_free(struct filedesc *fdp, int low, int size) 152{ 153 NDSLOTTYPE *map = fdp->fd_map; 154 NDSLOTTYPE mask; 155 int off, maxoff; 156 157 if (low >= size) 158 return (low); 159 160 off = NDSLOT(low); 161 if (low % NDENTRIES) { 162 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 163 if ((mask &= ~map[off]) != 0UL) 164 return (off * NDENTRIES + ffsl(mask) - 1); 165 ++off; 166 } 167 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 168 if (map[off] != ~0UL) 169 return (off * NDENTRIES + ffsl(~map[off]) - 1); 170 return (size); 171} 172 173/* 174 * Find the highest non-zero bit in the given bitmap, starting at low and 175 * not exceeding size - 1. 176 */ 177static int 178fd_last_used(struct filedesc *fdp, int low, int size) 179{ 180 NDSLOTTYPE *map = fdp->fd_map; 181 NDSLOTTYPE mask; 182 int off, minoff; 183 184 if (low >= size) 185 return (-1); 186 187 off = NDSLOT(size); 188 if (size % NDENTRIES) { 189 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 190 if ((mask &= map[off]) != 0) 191 return (off * NDENTRIES + flsl(mask) - 1); 192 --off; 193 } 194 for (minoff = NDSLOT(low); off >= minoff; --off) 195 if (map[off] != 0) 196 return (off * NDENTRIES + flsl(map[off]) - 1); 197 return (low - 1); 198} 199 200static int 201fdisused(struct filedesc *fdp, int fd) 202{ 203 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 204 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 205 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 206} 207 208/* 209 * Mark a file descriptor as used. 210 */ 211static void 212fdused(struct filedesc *fdp, int fd) 213{ 214 215 FILEDESC_XLOCK_ASSERT(fdp); 216 KASSERT(!fdisused(fdp, fd), 217 ("fd already used")); 218 219 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 220 if (fd > fdp->fd_lastfile) 221 fdp->fd_lastfile = fd; 222 if (fd == fdp->fd_freefile) 223 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 224} 225 226/* 227 * Mark a file descriptor as unused. 228 */ 229static void 230fdunused(struct filedesc *fdp, int fd) 231{ 232 233 FILEDESC_XLOCK_ASSERT(fdp); 234 KASSERT(fdisused(fdp, fd), 235 ("fd is already unused")); 236 KASSERT(fdp->fd_ofiles[fd] == NULL, 237 ("fd is still in use")); 238 239 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 240 if (fd < fdp->fd_freefile) 241 fdp->fd_freefile = fd; 242 if (fd == fdp->fd_lastfile) 243 fdp->fd_lastfile = fd_last_used(fdp, 0, fd); 244} 245 246/* 247 * System calls on descriptors. 248 */ 249#ifndef _SYS_SYSPROTO_H_ 250struct getdtablesize_args { 251 int dummy; 252}; 253#endif 254/* ARGSUSED */ 255int 256getdtablesize(struct thread *td, struct getdtablesize_args *uap) 257{ 258 struct proc *p = td->td_proc; 259 260 PROC_LOCK(p); 261 td->td_retval[0] = 262 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 263 PROC_UNLOCK(p); 264 return (0); 265} 266 267/* 268 * Duplicate a file descriptor to a particular value. 269 * 270 * Note: keep in mind that a potential race condition exists when closing 271 * descriptors from a shared descriptor table (via rfork). 272 */ 273#ifndef _SYS_SYSPROTO_H_ 274struct dup2_args { 275 u_int from; 276 u_int to; 277}; 278#endif 279/* ARGSUSED */ 280int 281dup2(struct thread *td, struct dup2_args *uap) 282{ 283 284 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 285 td->td_retval)); 286} 287 288/* 289 * Duplicate a file descriptor. 290 */ 291#ifndef _SYS_SYSPROTO_H_ 292struct dup_args { 293 u_int fd; 294}; 295#endif 296/* ARGSUSED */ 297int 298dup(struct thread *td, struct dup_args *uap) 299{ 300 301 return (do_dup(td, DUP_VARIABLE, (int)uap->fd, 0, td->td_retval)); 302} 303 304/* 305 * The file control system call. 306 */ 307#ifndef _SYS_SYSPROTO_H_ 308struct fcntl_args { 309 int fd; 310 int cmd; 311 long arg; 312}; 313#endif 314/* ARGSUSED */ 315int 316fcntl(struct thread *td, struct fcntl_args *uap) 317{ 318 struct flock fl; 319 intptr_t arg; 320 int error; 321 322 error = 0; 323 switch (uap->cmd) { 324 case F_GETLK: 325 case F_SETLK: 326 case F_SETLKW: 327 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl)); 328 arg = (intptr_t)&fl; 329 break; 330 default: 331 arg = uap->arg; 332 break; 333 } 334 if (error) 335 return (error); 336 error = kern_fcntl(td, uap->fd, uap->cmd, arg); 337 if (error) 338 return (error); 339 if (uap->cmd == F_GETLK) 340 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl)); 341 return (error); 342} 343 344static inline struct file * 345fdtofp(int fd, struct filedesc *fdp) 346{ 347 struct file *fp; 348 349 FILEDESC_LOCK_ASSERT(fdp); 350 if ((unsigned)fd >= fdp->fd_nfiles || 351 (fp = fdp->fd_ofiles[fd]) == NULL) 352 return (NULL); 353 return (fp); 354} 355 356int 357kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 358{ 359 struct filedesc *fdp; 360 struct flock *flp; 361 struct file *fp; 362 struct proc *p; 363 char *pop; 364 struct vnode *vp; 365 u_int newmin; 366 int error, flg, tmp; 367 int vfslocked; 368 369 vfslocked = 0; 370 error = 0; 371 flg = F_POSIX; 372 p = td->td_proc; 373 fdp = p->p_fd; 374 375 switch (cmd) { 376 case F_DUPFD: 377 FILEDESC_SLOCK(fdp); 378 if ((fp = fdtofp(fd, fdp)) == NULL) { 379 FILEDESC_SUNLOCK(fdp); 380 error = EBADF; 381 break; 382 } 383 FILEDESC_SUNLOCK(fdp); 384 newmin = arg; 385 PROC_LOCK(p); 386 if (newmin >= lim_cur(p, RLIMIT_NOFILE) || 387 newmin >= maxfilesperproc) { 388 PROC_UNLOCK(p); 389 error = EINVAL; 390 break; 391 } 392 PROC_UNLOCK(p); 393 error = do_dup(td, DUP_VARIABLE, fd, newmin, td->td_retval); 394 break; 395 396 case F_GETFD: 397 FILEDESC_SLOCK(fdp); 398 if ((fp = fdtofp(fd, fdp)) == NULL) { 399 FILEDESC_SUNLOCK(fdp); 400 error = EBADF; 401 break; 402 } 403 pop = &fdp->fd_ofileflags[fd]; 404 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 405 FILEDESC_SUNLOCK(fdp); 406 break; 407 408 case F_SETFD: 409 FILEDESC_XLOCK(fdp); 410 if ((fp = fdtofp(fd, fdp)) == NULL) { 411 FILEDESC_XUNLOCK(fdp); 412 error = EBADF; 413 break; 414 } 415 pop = &fdp->fd_ofileflags[fd]; 416 *pop = (*pop &~ UF_EXCLOSE) | 417 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 418 FILEDESC_XUNLOCK(fdp); 419 break; 420 421 case F_GETFL: 422 FILEDESC_SLOCK(fdp); 423 if ((fp = fdtofp(fd, fdp)) == NULL) { 424 FILEDESC_SUNLOCK(fdp); 425 error = EBADF; 426 break; 427 } 428 td->td_retval[0] = OFLAGS(fp->f_flag); 429 FILEDESC_SUNLOCK(fdp); 430 break; 431 432 case F_SETFL: 433 FILEDESC_SLOCK(fdp); 434 if ((fp = fdtofp(fd, fdp)) == NULL) { 435 FILEDESC_SUNLOCK(fdp); 436 error = EBADF; 437 break; 438 } 439 fhold(fp); 440 FILEDESC_SUNLOCK(fdp); 441 do { 442 tmp = flg = fp->f_flag; 443 tmp &= ~FCNTLFLAGS; 444 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 445 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 446 tmp = fp->f_flag & FNONBLOCK; 447 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 448 if (error) { 449 fdrop(fp, td); 450 break; 451 } 452 tmp = fp->f_flag & FASYNC; 453 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 454 if (error == 0) { 455 fdrop(fp, td); 456 break; 457 } 458 atomic_clear_int(&fp->f_flag, FNONBLOCK); 459 tmp = 0; 460 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 461 fdrop(fp, td); 462 break; 463 464 case F_GETOWN: 465 FILEDESC_SLOCK(fdp); 466 if ((fp = fdtofp(fd, fdp)) == NULL) { 467 FILEDESC_SUNLOCK(fdp); 468 error = EBADF; 469 break; 470 } 471 fhold(fp); 472 FILEDESC_SUNLOCK(fdp); 473 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 474 if (error == 0) 475 td->td_retval[0] = tmp; 476 fdrop(fp, td); 477 break; 478 479 case F_SETOWN: 480 FILEDESC_SLOCK(fdp); 481 if ((fp = fdtofp(fd, fdp)) == NULL) { 482 FILEDESC_SUNLOCK(fdp); 483 error = EBADF; 484 break; 485 } 486 fhold(fp); 487 FILEDESC_SUNLOCK(fdp); 488 tmp = arg; 489 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 490 fdrop(fp, td); 491 break; 492 493 case F_SETLKW: 494 flg |= F_WAIT; 495 /* FALLTHROUGH F_SETLK */ 496 497 case F_SETLK: 498 FILEDESC_SLOCK(fdp); 499 if ((fp = fdtofp(fd, fdp)) == NULL) { 500 FILEDESC_SUNLOCK(fdp); 501 error = EBADF; 502 break; 503 } 504 if (fp->f_type != DTYPE_VNODE) { 505 FILEDESC_SUNLOCK(fdp); 506 error = EBADF; 507 break; 508 } 509 flp = (struct flock *)arg; 510 if (flp->l_whence == SEEK_CUR) { 511 if (fp->f_offset < 0 || 512 (flp->l_start > 0 && 513 fp->f_offset > OFF_MAX - flp->l_start)) { 514 FILEDESC_SUNLOCK(fdp); 515 error = EOVERFLOW; 516 break; 517 } 518 flp->l_start += fp->f_offset; 519 } 520 521 /* 522 * VOP_ADVLOCK() may block. 523 */ 524 fhold(fp); 525 FILEDESC_SUNLOCK(fdp); 526 vp = fp->f_vnode; 527 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 528 switch (flp->l_type) { 529 case F_RDLCK: 530 if ((fp->f_flag & FREAD) == 0) { 531 error = EBADF; 532 break; 533 } 534 PROC_LOCK(p->p_leader); 535 p->p_leader->p_flag |= P_ADVLOCK; 536 PROC_UNLOCK(p->p_leader); 537 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 538 flp, flg); 539 break; 540 case F_WRLCK: 541 if ((fp->f_flag & FWRITE) == 0) { 542 error = EBADF; 543 break; 544 } 545 PROC_LOCK(p->p_leader); 546 p->p_leader->p_flag |= P_ADVLOCK; 547 PROC_UNLOCK(p->p_leader); 548 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 549 flp, flg); 550 break; 551 case F_UNLCK: 552 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 553 flp, F_POSIX); 554 break; 555 default: 556 error = EINVAL; 557 break; 558 } 559 VFS_UNLOCK_GIANT(vfslocked); 560 vfslocked = 0; 561 /* Check for race with close */ 562 FILEDESC_SLOCK(fdp); 563 if ((unsigned) fd >= fdp->fd_nfiles || 564 fp != fdp->fd_ofiles[fd]) { 565 FILEDESC_SUNLOCK(fdp); 566 flp->l_whence = SEEK_SET; 567 flp->l_start = 0; 568 flp->l_len = 0; 569 flp->l_type = F_UNLCK; 570 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 571 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 572 F_UNLCK, flp, F_POSIX); 573 VFS_UNLOCK_GIANT(vfslocked); 574 vfslocked = 0; 575 } else 576 FILEDESC_SUNLOCK(fdp); 577 fdrop(fp, td); 578 break; 579 580 case F_GETLK: 581 FILEDESC_SLOCK(fdp); 582 if ((fp = fdtofp(fd, fdp)) == NULL) { 583 FILEDESC_SUNLOCK(fdp); 584 error = EBADF; 585 break; 586 } 587 if (fp->f_type != DTYPE_VNODE) { 588 FILEDESC_SUNLOCK(fdp); 589 error = EBADF; 590 break; 591 } 592 flp = (struct flock *)arg; 593 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 594 flp->l_type != F_UNLCK) { 595 FILEDESC_SUNLOCK(fdp); 596 error = EINVAL; 597 break; 598 } 599 if (flp->l_whence == SEEK_CUR) { 600 if ((flp->l_start > 0 && 601 fp->f_offset > OFF_MAX - flp->l_start) || 602 (flp->l_start < 0 && 603 fp->f_offset < OFF_MIN - flp->l_start)) { 604 FILEDESC_SUNLOCK(fdp); 605 error = EOVERFLOW; 606 break; 607 } 608 flp->l_start += fp->f_offset; 609 } 610 /* 611 * VOP_ADVLOCK() may block. 612 */ 613 fhold(fp); 614 FILEDESC_SUNLOCK(fdp); 615 vp = fp->f_vnode; 616 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 617 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 618 F_POSIX); 619 VFS_UNLOCK_GIANT(vfslocked); 620 vfslocked = 0; 621 fdrop(fp, td); 622 break; 623 default: 624 error = EINVAL; 625 break; 626 } 627 VFS_UNLOCK_GIANT(vfslocked); 628 return (error); 629} 630 631/* 632 * Common code for dup, dup2, and fcntl(F_DUPFD). 633 */ 634static int 635do_dup(struct thread *td, enum dup_type type, int old, int new, 636 register_t *retval) 637{ 638 struct filedesc *fdp; 639 struct proc *p; 640 struct file *fp; 641 struct file *delfp; 642 int error, holdleaders, maxfd; 643 644 KASSERT((type == DUP_VARIABLE || type == DUP_FIXED), 645 ("invalid dup type %d", type)); 646 647 p = td->td_proc; 648 fdp = p->p_fd; 649 650 /* 651 * Verify we have a valid descriptor to dup from and possibly to 652 * dup to. 653 */ 654 if (old < 0 || new < 0) 655 return (EBADF); 656 PROC_LOCK(p); 657 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 658 PROC_UNLOCK(p); 659 if (new >= maxfd) 660 return (EMFILE); 661 662 FILEDESC_XLOCK(fdp); 663 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 664 FILEDESC_XUNLOCK(fdp); 665 return (EBADF); 666 } 667 if (type == DUP_FIXED && old == new) { 668 *retval = new; 669 FILEDESC_XUNLOCK(fdp); 670 return (0); 671 } 672 fp = fdp->fd_ofiles[old]; 673 fhold(fp); 674 675 /* 676 * If the caller specified a file descriptor, make sure the file 677 * table is large enough to hold it, and grab it. Otherwise, just 678 * allocate a new descriptor the usual way. Since the filedesc 679 * lock may be temporarily dropped in the process, we have to look 680 * out for a race. 681 */ 682 if (type == DUP_FIXED) { 683 if (new >= fdp->fd_nfiles) 684 fdgrowtable(fdp, new + 1); 685 if (fdp->fd_ofiles[new] == NULL) 686 fdused(fdp, new); 687 } else { 688 if ((error = fdalloc(td, new, &new)) != 0) { 689 FILEDESC_XUNLOCK(fdp); 690 fdrop(fp, td); 691 return (error); 692 } 693 } 694 695 /* 696 * If the old file changed out from under us then treat it as a 697 * bad file descriptor. Userland should do its own locking to 698 * avoid this case. 699 */ 700 if (fdp->fd_ofiles[old] != fp) { 701 /* we've allocated a descriptor which we won't use */ 702 if (fdp->fd_ofiles[new] == NULL) 703 fdunused(fdp, new); 704 FILEDESC_XUNLOCK(fdp); 705 fdrop(fp, td); 706 return (EBADF); 707 } 708 KASSERT(old != new, 709 ("new fd is same as old")); 710 711 /* 712 * Save info on the descriptor being overwritten. We cannot close 713 * it without introducing an ownership race for the slot, since we 714 * need to drop the filedesc lock to call closef(). 715 * 716 * XXX this duplicates parts of close(). 717 */ 718 delfp = fdp->fd_ofiles[new]; 719 holdleaders = 0; 720 if (delfp != NULL) { 721 if (td->td_proc->p_fdtol != NULL) { 722 /* 723 * Ask fdfree() to sleep to ensure that all relevant 724 * process leaders can be traversed in closef(). 725 */ 726 fdp->fd_holdleaderscount++; 727 holdleaders = 1; 728 } 729 } 730 731 /* 732 * Duplicate the source descriptor 733 */ 734 fdp->fd_ofiles[new] = fp; 735 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 736 if (new > fdp->fd_lastfile) 737 fdp->fd_lastfile = new; 738 *retval = new; 739 740 /* 741 * If we dup'd over a valid file, we now own the reference to it 742 * and must dispose of it using closef() semantics (as if a 743 * close() were performed on it). 744 * 745 * XXX this duplicates parts of close(). 746 */ 747 if (delfp != NULL) { 748 knote_fdclose(td, new); 749 if (delfp->f_type == DTYPE_MQUEUE) 750 mq_fdclose(td, new, delfp); 751 FILEDESC_XUNLOCK(fdp); 752 (void) closef(delfp, td); 753 if (holdleaders) { 754 FILEDESC_XLOCK(fdp); 755 fdp->fd_holdleaderscount--; 756 if (fdp->fd_holdleaderscount == 0 && 757 fdp->fd_holdleaderswakeup != 0) { 758 fdp->fd_holdleaderswakeup = 0; 759 wakeup(&fdp->fd_holdleaderscount); 760 } 761 FILEDESC_XUNLOCK(fdp); 762 } 763 } else { 764 FILEDESC_XUNLOCK(fdp); 765 } 766 return (0); 767} 768 769/* 770 * If sigio is on the list associated with a process or process group, 771 * disable signalling from the device, remove sigio from the list and 772 * free sigio. 773 */ 774void 775funsetown(struct sigio **sigiop) 776{ 777 struct sigio *sigio; 778 779 SIGIO_LOCK(); 780 sigio = *sigiop; 781 if (sigio == NULL) { 782 SIGIO_UNLOCK(); 783 return; 784 } 785 *(sigio->sio_myref) = NULL; 786 if ((sigio)->sio_pgid < 0) { 787 struct pgrp *pg = (sigio)->sio_pgrp; 788 PGRP_LOCK(pg); 789 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 790 sigio, sio_pgsigio); 791 PGRP_UNLOCK(pg); 792 } else { 793 struct proc *p = (sigio)->sio_proc; 794 PROC_LOCK(p); 795 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 796 sigio, sio_pgsigio); 797 PROC_UNLOCK(p); 798 } 799 SIGIO_UNLOCK(); 800 crfree(sigio->sio_ucred); 801 FREE(sigio, M_SIGIO); 802} 803 804/* 805 * Free a list of sigio structures. 806 * We only need to lock the SIGIO_LOCK because we have made ourselves 807 * inaccessible to callers of fsetown and therefore do not need to lock 808 * the proc or pgrp struct for the list manipulation. 809 */ 810void 811funsetownlst(struct sigiolst *sigiolst) 812{ 813 struct proc *p; 814 struct pgrp *pg; 815 struct sigio *sigio; 816 817 sigio = SLIST_FIRST(sigiolst); 818 if (sigio == NULL) 819 return; 820 p = NULL; 821 pg = NULL; 822 823 /* 824 * Every entry of the list should belong 825 * to a single proc or pgrp. 826 */ 827 if (sigio->sio_pgid < 0) { 828 pg = sigio->sio_pgrp; 829 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 830 } else /* if (sigio->sio_pgid > 0) */ { 831 p = sigio->sio_proc; 832 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 833 } 834 835 SIGIO_LOCK(); 836 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 837 *(sigio->sio_myref) = NULL; 838 if (pg != NULL) { 839 KASSERT(sigio->sio_pgid < 0, 840 ("Proc sigio in pgrp sigio list")); 841 KASSERT(sigio->sio_pgrp == pg, 842 ("Bogus pgrp in sigio list")); 843 PGRP_LOCK(pg); 844 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 845 sio_pgsigio); 846 PGRP_UNLOCK(pg); 847 } else /* if (p != NULL) */ { 848 KASSERT(sigio->sio_pgid > 0, 849 ("Pgrp sigio in proc sigio list")); 850 KASSERT(sigio->sio_proc == p, 851 ("Bogus proc in sigio list")); 852 PROC_LOCK(p); 853 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 854 sio_pgsigio); 855 PROC_UNLOCK(p); 856 } 857 SIGIO_UNLOCK(); 858 crfree(sigio->sio_ucred); 859 FREE(sigio, M_SIGIO); 860 SIGIO_LOCK(); 861 } 862 SIGIO_UNLOCK(); 863} 864 865/* 866 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 867 * 868 * After permission checking, add a sigio structure to the sigio list for 869 * the process or process group. 870 */ 871int 872fsetown(pid_t pgid, struct sigio **sigiop) 873{ 874 struct proc *proc; 875 struct pgrp *pgrp; 876 struct sigio *sigio; 877 int ret; 878 879 if (pgid == 0) { 880 funsetown(sigiop); 881 return (0); 882 } 883 884 ret = 0; 885 886 /* Allocate and fill in the new sigio out of locks. */ 887 MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK); 888 sigio->sio_pgid = pgid; 889 sigio->sio_ucred = crhold(curthread->td_ucred); 890 sigio->sio_myref = sigiop; 891 892 sx_slock(&proctree_lock); 893 if (pgid > 0) { 894 proc = pfind(pgid); 895 if (proc == NULL) { 896 ret = ESRCH; 897 goto fail; 898 } 899 900 /* 901 * Policy - Don't allow a process to FSETOWN a process 902 * in another session. 903 * 904 * Remove this test to allow maximum flexibility or 905 * restrict FSETOWN to the current process or process 906 * group for maximum safety. 907 */ 908 PROC_UNLOCK(proc); 909 if (proc->p_session != curthread->td_proc->p_session) { 910 ret = EPERM; 911 goto fail; 912 } 913 914 pgrp = NULL; 915 } else /* if (pgid < 0) */ { 916 pgrp = pgfind(-pgid); 917 if (pgrp == NULL) { 918 ret = ESRCH; 919 goto fail; 920 } 921 PGRP_UNLOCK(pgrp); 922 923 /* 924 * Policy - Don't allow a process to FSETOWN a process 925 * in another session. 926 * 927 * Remove this test to allow maximum flexibility or 928 * restrict FSETOWN to the current process or process 929 * group for maximum safety. 930 */ 931 if (pgrp->pg_session != curthread->td_proc->p_session) { 932 ret = EPERM; 933 goto fail; 934 } 935 936 proc = NULL; 937 } 938 funsetown(sigiop); 939 if (pgid > 0) { 940 PROC_LOCK(proc); 941 /* 942 * Since funsetownlst() is called without the proctree 943 * locked, we need to check for P_WEXIT. 944 * XXX: is ESRCH correct? 945 */ 946 if ((proc->p_flag & P_WEXIT) != 0) { 947 PROC_UNLOCK(proc); 948 ret = ESRCH; 949 goto fail; 950 } 951 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 952 sigio->sio_proc = proc; 953 PROC_UNLOCK(proc); 954 } else { 955 PGRP_LOCK(pgrp); 956 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 957 sigio->sio_pgrp = pgrp; 958 PGRP_UNLOCK(pgrp); 959 } 960 sx_sunlock(&proctree_lock); 961 SIGIO_LOCK(); 962 *sigiop = sigio; 963 SIGIO_UNLOCK(); 964 return (0); 965 966fail: 967 sx_sunlock(&proctree_lock); 968 crfree(sigio->sio_ucred); 969 FREE(sigio, M_SIGIO); 970 return (ret); 971} 972 973/* 974 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 975 */ 976pid_t 977fgetown(sigiop) 978 struct sigio **sigiop; 979{ 980 pid_t pgid; 981 982 SIGIO_LOCK(); 983 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 984 SIGIO_UNLOCK(); 985 return (pgid); 986} 987 988/* 989 * Close a file descriptor. 990 */ 991#ifndef _SYS_SYSPROTO_H_ 992struct close_args { 993 int fd; 994}; 995#endif 996/* ARGSUSED */ 997int 998close(td, uap) 999 struct thread *td; 1000 struct close_args *uap; 1001{ 1002 1003 return (kern_close(td, uap->fd)); 1004} 1005 1006int 1007kern_close(td, fd) 1008 struct thread *td; 1009 int fd; 1010{ 1011 struct filedesc *fdp; 1012 struct file *fp; 1013 int error; 1014 int holdleaders; 1015 1016 error = 0; 1017 holdleaders = 0; 1018 fdp = td->td_proc->p_fd; 1019 1020 AUDIT_SYSCLOSE(td, fd); 1021 1022 FILEDESC_XLOCK(fdp); 1023 if ((unsigned)fd >= fdp->fd_nfiles || 1024 (fp = fdp->fd_ofiles[fd]) == NULL) { 1025 FILEDESC_XUNLOCK(fdp); 1026 return (EBADF); 1027 } 1028 fdp->fd_ofiles[fd] = NULL; 1029 fdp->fd_ofileflags[fd] = 0; 1030 fdunused(fdp, fd); 1031 if (td->td_proc->p_fdtol != NULL) { 1032 /* 1033 * Ask fdfree() to sleep to ensure that all relevant 1034 * process leaders can be traversed in closef(). 1035 */ 1036 fdp->fd_holdleaderscount++; 1037 holdleaders = 1; 1038 } 1039 1040 /* 1041 * We now hold the fp reference that used to be owned by the 1042 * descriptor array. We have to unlock the FILEDESC *AFTER* 1043 * knote_fdclose to prevent a race of the fd getting opened, a knote 1044 * added, and deleteing a knote for the new fd. 1045 */ 1046 knote_fdclose(td, fd); 1047 if (fp->f_type == DTYPE_MQUEUE) 1048 mq_fdclose(td, fd, fp); 1049 FILEDESC_XUNLOCK(fdp); 1050 1051 error = closef(fp, td); 1052 if (holdleaders) { 1053 FILEDESC_XLOCK(fdp); 1054 fdp->fd_holdleaderscount--; 1055 if (fdp->fd_holdleaderscount == 0 && 1056 fdp->fd_holdleaderswakeup != 0) { 1057 fdp->fd_holdleaderswakeup = 0; 1058 wakeup(&fdp->fd_holdleaderscount); 1059 } 1060 FILEDESC_XUNLOCK(fdp); 1061 } 1062 return (error); 1063} 1064 1065#if defined(COMPAT_43) 1066/* 1067 * Return status information about a file descriptor. 1068 */ 1069#ifndef _SYS_SYSPROTO_H_ 1070struct ofstat_args { 1071 int fd; 1072 struct ostat *sb; 1073}; 1074#endif 1075/* ARGSUSED */ 1076int 1077ofstat(struct thread *td, struct ofstat_args *uap) 1078{ 1079 struct ostat oub; 1080 struct stat ub; 1081 int error; 1082 1083 error = kern_fstat(td, uap->fd, &ub); 1084 if (error == 0) { 1085 cvtstat(&ub, &oub); 1086 error = copyout(&oub, uap->sb, sizeof(oub)); 1087 } 1088 return (error); 1089} 1090#endif /* COMPAT_43 */ 1091 1092/* 1093 * Return status information about a file descriptor. 1094 */ 1095#ifndef _SYS_SYSPROTO_H_ 1096struct fstat_args { 1097 int fd; 1098 struct stat *sb; 1099}; 1100#endif 1101/* ARGSUSED */ 1102int 1103fstat(struct thread *td, struct fstat_args *uap) 1104{ 1105 struct stat ub; 1106 int error; 1107 1108 error = kern_fstat(td, uap->fd, &ub); 1109 if (error == 0) 1110 error = copyout(&ub, uap->sb, sizeof(ub)); 1111 return (error); 1112} 1113 1114int 1115kern_fstat(struct thread *td, int fd, struct stat *sbp) 1116{ 1117 struct file *fp; 1118 int error; 1119 1120 AUDIT_ARG(fd, fd); 1121 1122 if ((error = fget(td, fd, &fp)) != 0) 1123 return (error); 1124 1125 AUDIT_ARG(file, td->td_proc, fp); 1126 1127 error = fo_stat(fp, sbp, td->td_ucred, td); 1128 fdrop(fp, td); 1129 return (error); 1130} 1131 1132/* 1133 * Return status information about a file descriptor. 1134 */ 1135#ifndef _SYS_SYSPROTO_H_ 1136struct nfstat_args { 1137 int fd; 1138 struct nstat *sb; 1139}; 1140#endif 1141/* ARGSUSED */ 1142int 1143nfstat(struct thread *td, struct nfstat_args *uap) 1144{ 1145 struct nstat nub; 1146 struct stat ub; 1147 int error; 1148 1149 error = kern_fstat(td, uap->fd, &ub); 1150 if (error == 0) { 1151 cvtnstat(&ub, &nub); 1152 error = copyout(&nub, uap->sb, sizeof(nub)); 1153 } 1154 return (error); 1155} 1156 1157/* 1158 * Return pathconf information about a file descriptor. 1159 */ 1160#ifndef _SYS_SYSPROTO_H_ 1161struct fpathconf_args { 1162 int fd; 1163 int name; 1164}; 1165#endif 1166/* ARGSUSED */ 1167int 1168fpathconf(struct thread *td, struct fpathconf_args *uap) 1169{ 1170 struct file *fp; 1171 struct vnode *vp; 1172 int error; 1173 1174 if ((error = fget(td, uap->fd, &fp)) != 0) 1175 return (error); 1176 1177 /* If asynchronous I/O is available, it works for all descriptors. */ 1178 if (uap->name == _PC_ASYNC_IO) { 1179 td->td_retval[0] = async_io_version; 1180 goto out; 1181 } 1182 vp = fp->f_vnode; 1183 if (vp != NULL) { 1184 int vfslocked; 1185 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1186 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1187 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1188 VOP_UNLOCK(vp, 0); 1189 VFS_UNLOCK_GIANT(vfslocked); 1190 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1191 if (uap->name != _PC_PIPE_BUF) { 1192 error = EINVAL; 1193 } else { 1194 td->td_retval[0] = PIPE_BUF; 1195 error = 0; 1196 } 1197 } else { 1198 error = EOPNOTSUPP; 1199 } 1200out: 1201 fdrop(fp, td); 1202 return (error); 1203} 1204 1205/* 1206 * Grow the file table to accomodate (at least) nfd descriptors. This may 1207 * block and drop the filedesc lock, but it will reacquire it before 1208 * returning. 1209 */ 1210static void 1211fdgrowtable(struct filedesc *fdp, int nfd) 1212{ 1213 struct file **ntable; 1214 char *nfileflags; 1215 int nnfiles, onfiles; 1216 NDSLOTTYPE *nmap; 1217 1218 FILEDESC_XLOCK_ASSERT(fdp); 1219 1220 KASSERT(fdp->fd_nfiles > 0, 1221 ("zero-length file table")); 1222 1223 /* compute the size of the new table */ 1224 onfiles = fdp->fd_nfiles; 1225 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1226 if (nnfiles <= onfiles) 1227 /* the table is already large enough */ 1228 return; 1229 1230 /* allocate a new table and (if required) new bitmaps */ 1231 FILEDESC_XUNLOCK(fdp); 1232 MALLOC(ntable, struct file **, nnfiles * OFILESIZE, 1233 M_FILEDESC, M_ZERO | M_WAITOK); 1234 nfileflags = (char *)&ntable[nnfiles]; 1235 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) 1236 MALLOC(nmap, NDSLOTTYPE *, NDSLOTS(nnfiles) * NDSLOTSIZE, 1237 M_FILEDESC, M_ZERO | M_WAITOK); 1238 else 1239 nmap = NULL; 1240 FILEDESC_XLOCK(fdp); 1241 1242 /* 1243 * We now have new tables ready to go. Since we dropped the 1244 * filedesc lock to call malloc(), watch out for a race. 1245 */ 1246 onfiles = fdp->fd_nfiles; 1247 if (onfiles >= nnfiles) { 1248 /* we lost the race, but that's OK */ 1249 free(ntable, M_FILEDESC); 1250 if (nmap != NULL) 1251 free(nmap, M_FILEDESC); 1252 return; 1253 } 1254 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable)); 1255 bcopy(fdp->fd_ofileflags, nfileflags, onfiles); 1256 if (onfiles > NDFILE) 1257 free(fdp->fd_ofiles, M_FILEDESC); 1258 fdp->fd_ofiles = ntable; 1259 fdp->fd_ofileflags = nfileflags; 1260 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1261 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap)); 1262 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1263 free(fdp->fd_map, M_FILEDESC); 1264 fdp->fd_map = nmap; 1265 } 1266 fdp->fd_nfiles = nnfiles; 1267} 1268 1269/* 1270 * Allocate a file descriptor for the process. 1271 */ 1272int 1273fdalloc(struct thread *td, int minfd, int *result) 1274{ 1275 struct proc *p = td->td_proc; 1276 struct filedesc *fdp = p->p_fd; 1277 int fd = -1, maxfd; 1278 1279 FILEDESC_XLOCK_ASSERT(fdp); 1280 1281 if (fdp->fd_freefile > minfd) 1282 minfd = fdp->fd_freefile; 1283 1284 PROC_LOCK(p); 1285 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1286 PROC_UNLOCK(p); 1287 1288 /* 1289 * Search the bitmap for a free descriptor. If none is found, try 1290 * to grow the file table. Keep at it until we either get a file 1291 * descriptor or run into process or system limits; fdgrowtable() 1292 * may drop the filedesc lock, so we're in a race. 1293 */ 1294 for (;;) { 1295 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1296 if (fd >= maxfd) 1297 return (EMFILE); 1298 if (fd < fdp->fd_nfiles) 1299 break; 1300 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd)); 1301 } 1302 1303 /* 1304 * Perform some sanity checks, then mark the file descriptor as 1305 * used and return it to the caller. 1306 */ 1307 KASSERT(!fdisused(fdp, fd), 1308 ("fd_first_free() returned non-free descriptor")); 1309 KASSERT(fdp->fd_ofiles[fd] == NULL, 1310 ("free descriptor isn't")); 1311 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */ 1312 fdused(fdp, fd); 1313 *result = fd; 1314 return (0); 1315} 1316 1317/* 1318 * Check to see whether n user file descriptors are available to the process 1319 * p. 1320 */ 1321int 1322fdavail(struct thread *td, int n) 1323{ 1324 struct proc *p = td->td_proc; 1325 struct filedesc *fdp = td->td_proc->p_fd; 1326 struct file **fpp; 1327 int i, lim, last; 1328 1329 FILEDESC_LOCK_ASSERT(fdp); 1330 1331 PROC_LOCK(p); 1332 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1333 PROC_UNLOCK(p); 1334 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1335 return (1); 1336 last = min(fdp->fd_nfiles, lim); 1337 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 1338 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 1339 if (*fpp == NULL && --n <= 0) 1340 return (1); 1341 } 1342 return (0); 1343} 1344 1345/* 1346 * Create a new open file structure and allocate a file decriptor for the 1347 * process that refers to it. We add one reference to the file for the 1348 * descriptor table and one reference for resultfp. This is to prevent us 1349 * being preempted and the entry in the descriptor table closed after we 1350 * release the FILEDESC lock. 1351 */ 1352int 1353falloc(struct thread *td, struct file **resultfp, int *resultfd) 1354{ 1355 struct proc *p = td->td_proc; 1356 struct file *fp; 1357 int error, i; 1358 int maxuserfiles = maxfiles - (maxfiles / 20); 1359 static struct timeval lastfail; 1360 static int curfail; 1361 1362 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1363 if ((openfiles >= maxuserfiles && 1364 priv_check(td, PRIV_MAXFILES) != 0) || 1365 openfiles >= maxfiles) { 1366 if (ppsratecheck(&lastfail, &curfail, 1)) { 1367 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n", 1368 td->td_ucred->cr_ruid); 1369 } 1370 uma_zfree(file_zone, fp); 1371 return (ENFILE); 1372 } 1373 atomic_add_int(&openfiles, 1); 1374 1375 /* 1376 * If the process has file descriptor zero open, add the new file 1377 * descriptor to the list of open files at that point, otherwise 1378 * put it at the front of the list of open files. 1379 */ 1380 fp->f_count = 1; 1381 if (resultfp) 1382 fp->f_count++; 1383 fp->f_cred = crhold(td->td_ucred); 1384 fp->f_ops = &badfileops; 1385 fp->f_data = NULL; 1386 fp->f_vnode = NULL; 1387 FILEDESC_XLOCK(p->p_fd); 1388 if ((error = fdalloc(td, 0, &i))) { 1389 FILEDESC_XUNLOCK(p->p_fd); 1390 fdrop(fp, td); 1391 if (resultfp) 1392 fdrop(fp, td); 1393 return (error); 1394 } 1395 p->p_fd->fd_ofiles[i] = fp; 1396 FILEDESC_XUNLOCK(p->p_fd); 1397 if (resultfp) 1398 *resultfp = fp; 1399 if (resultfd) 1400 *resultfd = i; 1401 return (0); 1402} 1403 1404/* 1405 * Build a new filedesc structure from another. 1406 * Copy the current, root, and jail root vnode references. 1407 */ 1408struct filedesc * 1409fdinit(struct filedesc *fdp) 1410{ 1411 struct filedesc0 *newfdp; 1412 1413 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO); 1414 FILEDESC_LOCK_INIT(&newfdp->fd_fd); 1415 if (fdp != NULL) { 1416 FILEDESC_XLOCK(fdp); 1417 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1418 if (newfdp->fd_fd.fd_cdir) 1419 VREF(newfdp->fd_fd.fd_cdir); 1420 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1421 if (newfdp->fd_fd.fd_rdir) 1422 VREF(newfdp->fd_fd.fd_rdir); 1423 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1424 if (newfdp->fd_fd.fd_jdir) 1425 VREF(newfdp->fd_fd.fd_jdir); 1426 FILEDESC_XUNLOCK(fdp); 1427 } 1428 1429 /* Create the file descriptor table. */ 1430 newfdp->fd_fd.fd_refcnt = 1; 1431 newfdp->fd_fd.fd_holdcnt = 1; 1432 newfdp->fd_fd.fd_cmask = CMASK; 1433 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1434 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1435 newfdp->fd_fd.fd_nfiles = NDFILE; 1436 newfdp->fd_fd.fd_map = newfdp->fd_dmap; 1437 newfdp->fd_fd.fd_lastfile = -1; 1438 return (&newfdp->fd_fd); 1439} 1440 1441static struct filedesc * 1442fdhold(struct proc *p) 1443{ 1444 struct filedesc *fdp; 1445 1446 mtx_lock(&fdesc_mtx); 1447 fdp = p->p_fd; 1448 if (fdp != NULL) 1449 fdp->fd_holdcnt++; 1450 mtx_unlock(&fdesc_mtx); 1451 return (fdp); 1452} 1453 1454static void 1455fddrop(struct filedesc *fdp) 1456{ 1457 int i; 1458 1459 mtx_lock(&fdesc_mtx); 1460 i = --fdp->fd_holdcnt; 1461 mtx_unlock(&fdesc_mtx); 1462 if (i > 0) 1463 return; 1464 1465 FILEDESC_LOCK_DESTROY(fdp); 1466 FREE(fdp, M_FILEDESC); 1467} 1468 1469/* 1470 * Share a filedesc structure. 1471 */ 1472struct filedesc * 1473fdshare(struct filedesc *fdp) 1474{ 1475 1476 FILEDESC_XLOCK(fdp); 1477 fdp->fd_refcnt++; 1478 FILEDESC_XUNLOCK(fdp); 1479 return (fdp); 1480} 1481 1482/* 1483 * Unshare a filedesc structure, if necessary by making a copy 1484 */ 1485void 1486fdunshare(struct proc *p, struct thread *td) 1487{ 1488 1489 FILEDESC_XLOCK(p->p_fd); 1490 if (p->p_fd->fd_refcnt > 1) { 1491 struct filedesc *tmp; 1492 1493 FILEDESC_XUNLOCK(p->p_fd); 1494 tmp = fdcopy(p->p_fd); 1495 fdfree(td); 1496 p->p_fd = tmp; 1497 } else 1498 FILEDESC_XUNLOCK(p->p_fd); 1499} 1500 1501/* 1502 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1503 * this is to ease callers, not catch errors. 1504 */ 1505struct filedesc * 1506fdcopy(struct filedesc *fdp) 1507{ 1508 struct filedesc *newfdp; 1509 int i; 1510 1511 /* Certain daemons might not have file descriptors. */ 1512 if (fdp == NULL) 1513 return (NULL); 1514 1515 newfdp = fdinit(fdp); 1516 FILEDESC_SLOCK(fdp); 1517 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1518 FILEDESC_SUNLOCK(fdp); 1519 FILEDESC_XLOCK(newfdp); 1520 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1521 FILEDESC_XUNLOCK(newfdp); 1522 FILEDESC_SLOCK(fdp); 1523 } 1524 /* copy everything except kqueue descriptors */ 1525 newfdp->fd_freefile = -1; 1526 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1527 if (fdisused(fdp, i) && 1528 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE) { 1529 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i]; 1530 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i]; 1531 fhold(newfdp->fd_ofiles[i]); 1532 newfdp->fd_lastfile = i; 1533 } else { 1534 if (newfdp->fd_freefile == -1) 1535 newfdp->fd_freefile = i; 1536 } 1537 } 1538 FILEDESC_SUNLOCK(fdp); 1539 FILEDESC_XLOCK(newfdp); 1540 for (i = 0; i <= newfdp->fd_lastfile; ++i) 1541 if (newfdp->fd_ofiles[i] != NULL) 1542 fdused(newfdp, i); 1543 FILEDESC_XUNLOCK(newfdp); 1544 FILEDESC_SLOCK(fdp); 1545 if (newfdp->fd_freefile == -1) 1546 newfdp->fd_freefile = i; 1547 newfdp->fd_cmask = fdp->fd_cmask; 1548 FILEDESC_SUNLOCK(fdp); 1549 return (newfdp); 1550} 1551 1552/* 1553 * Release a filedesc structure. 1554 */ 1555void 1556fdfree(struct thread *td) 1557{ 1558 struct filedesc *fdp; 1559 struct file **fpp; 1560 int i, locked; 1561 struct filedesc_to_leader *fdtol; 1562 struct file *fp; 1563 struct vnode *cdir, *jdir, *rdir, *vp; 1564 struct flock lf; 1565 1566 /* Certain daemons might not have file descriptors. */ 1567 fdp = td->td_proc->p_fd; 1568 if (fdp == NULL) 1569 return; 1570 1571 /* Check for special need to clear POSIX style locks */ 1572 fdtol = td->td_proc->p_fdtol; 1573 if (fdtol != NULL) { 1574 FILEDESC_XLOCK(fdp); 1575 KASSERT(fdtol->fdl_refcount > 0, 1576 ("filedesc_to_refcount botch: fdl_refcount=%d", 1577 fdtol->fdl_refcount)); 1578 if (fdtol->fdl_refcount == 1 && 1579 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1580 for (i = 0, fpp = fdp->fd_ofiles; 1581 i <= fdp->fd_lastfile; 1582 i++, fpp++) { 1583 if (*fpp == NULL || 1584 (*fpp)->f_type != DTYPE_VNODE) 1585 continue; 1586 fp = *fpp; 1587 fhold(fp); 1588 FILEDESC_XUNLOCK(fdp); 1589 lf.l_whence = SEEK_SET; 1590 lf.l_start = 0; 1591 lf.l_len = 0; 1592 lf.l_type = F_UNLCK; 1593 vp = fp->f_vnode; 1594 locked = VFS_LOCK_GIANT(vp->v_mount); 1595 (void) VOP_ADVLOCK(vp, 1596 (caddr_t)td->td_proc-> 1597 p_leader, 1598 F_UNLCK, 1599 &lf, 1600 F_POSIX); 1601 VFS_UNLOCK_GIANT(locked); 1602 FILEDESC_XLOCK(fdp); 1603 fdrop(fp, td); 1604 fpp = fdp->fd_ofiles + i; 1605 } 1606 } 1607 retry: 1608 if (fdtol->fdl_refcount == 1) { 1609 if (fdp->fd_holdleaderscount > 0 && 1610 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1611 /* 1612 * close() or do_dup() has cleared a reference 1613 * in a shared file descriptor table. 1614 */ 1615 fdp->fd_holdleaderswakeup = 1; 1616 sx_sleep(&fdp->fd_holdleaderscount, 1617 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1618 goto retry; 1619 } 1620 if (fdtol->fdl_holdcount > 0) { 1621 /* 1622 * Ensure that fdtol->fdl_leader remains 1623 * valid in closef(). 1624 */ 1625 fdtol->fdl_wakeup = 1; 1626 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 1627 "fdlhold", 0); 1628 goto retry; 1629 } 1630 } 1631 fdtol->fdl_refcount--; 1632 if (fdtol->fdl_refcount == 0 && 1633 fdtol->fdl_holdcount == 0) { 1634 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1635 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1636 } else 1637 fdtol = NULL; 1638 td->td_proc->p_fdtol = NULL; 1639 FILEDESC_XUNLOCK(fdp); 1640 if (fdtol != NULL) 1641 FREE(fdtol, M_FILEDESC_TO_LEADER); 1642 } 1643 FILEDESC_XLOCK(fdp); 1644 i = --fdp->fd_refcnt; 1645 FILEDESC_XUNLOCK(fdp); 1646 if (i > 0) 1647 return; 1648 /* 1649 * We are the last reference to the structure, so we can 1650 * safely assume it will not change out from under us. 1651 */ 1652 fpp = fdp->fd_ofiles; 1653 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1654 if (*fpp) 1655 (void) closef(*fpp, td); 1656 } 1657 FILEDESC_XLOCK(fdp); 1658 1659 /* XXX This should happen earlier. */ 1660 mtx_lock(&fdesc_mtx); 1661 td->td_proc->p_fd = NULL; 1662 mtx_unlock(&fdesc_mtx); 1663 1664 if (fdp->fd_nfiles > NDFILE) 1665 FREE(fdp->fd_ofiles, M_FILEDESC); 1666 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 1667 FREE(fdp->fd_map, M_FILEDESC); 1668 1669 fdp->fd_nfiles = 0; 1670 1671 cdir = fdp->fd_cdir; 1672 fdp->fd_cdir = NULL; 1673 rdir = fdp->fd_rdir; 1674 fdp->fd_rdir = NULL; 1675 jdir = fdp->fd_jdir; 1676 fdp->fd_jdir = NULL; 1677 FILEDESC_XUNLOCK(fdp); 1678 1679 if (cdir) { 1680 locked = VFS_LOCK_GIANT(cdir->v_mount); 1681 vrele(cdir); 1682 VFS_UNLOCK_GIANT(locked); 1683 } 1684 if (rdir) { 1685 locked = VFS_LOCK_GIANT(rdir->v_mount); 1686 vrele(rdir); 1687 VFS_UNLOCK_GIANT(locked); 1688 } 1689 if (jdir) { 1690 locked = VFS_LOCK_GIANT(jdir->v_mount); 1691 vrele(jdir); 1692 VFS_UNLOCK_GIANT(locked); 1693 } 1694 1695 fddrop(fdp); 1696} 1697 1698/* 1699 * For setugid programs, we don't want to people to use that setugidness 1700 * to generate error messages which write to a file which otherwise would 1701 * otherwise be off-limits to the process. We check for filesystems where 1702 * the vnode can change out from under us after execve (like [lin]procfs). 1703 * 1704 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1705 * sufficient. We also don't check for setugidness since we know we are. 1706 */ 1707static int 1708is_unsafe(struct file *fp) 1709{ 1710 if (fp->f_type == DTYPE_VNODE) { 1711 struct vnode *vp = fp->f_vnode; 1712 1713 if ((vp->v_vflag & VV_PROCDEP) != 0) 1714 return (1); 1715 } 1716 return (0); 1717} 1718 1719/* 1720 * Make this setguid thing safe, if at all possible. 1721 */ 1722void 1723setugidsafety(struct thread *td) 1724{ 1725 struct filedesc *fdp; 1726 int i; 1727 1728 /* Certain daemons might not have file descriptors. */ 1729 fdp = td->td_proc->p_fd; 1730 if (fdp == NULL) 1731 return; 1732 1733 /* 1734 * Note: fdp->fd_ofiles may be reallocated out from under us while 1735 * we are blocked in a close. Be careful! 1736 */ 1737 FILEDESC_XLOCK(fdp); 1738 for (i = 0; i <= fdp->fd_lastfile; i++) { 1739 if (i > 2) 1740 break; 1741 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1742 struct file *fp; 1743 1744 knote_fdclose(td, i); 1745 /* 1746 * NULL-out descriptor prior to close to avoid 1747 * a race while close blocks. 1748 */ 1749 fp = fdp->fd_ofiles[i]; 1750 fdp->fd_ofiles[i] = NULL; 1751 fdp->fd_ofileflags[i] = 0; 1752 fdunused(fdp, i); 1753 FILEDESC_XUNLOCK(fdp); 1754 (void) closef(fp, td); 1755 FILEDESC_XLOCK(fdp); 1756 } 1757 } 1758 FILEDESC_XUNLOCK(fdp); 1759} 1760 1761/* 1762 * If a specific file object occupies a specific file descriptor, close the 1763 * file descriptor entry and drop a reference on the file object. This is a 1764 * convenience function to handle a subsequent error in a function that calls 1765 * falloc() that handles the race that another thread might have closed the 1766 * file descriptor out from under the thread creating the file object. 1767 */ 1768void 1769fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 1770{ 1771 1772 FILEDESC_XLOCK(fdp); 1773 if (fdp->fd_ofiles[idx] == fp) { 1774 fdp->fd_ofiles[idx] = NULL; 1775 fdunused(fdp, idx); 1776 FILEDESC_XUNLOCK(fdp); 1777 fdrop(fp, td); 1778 } else 1779 FILEDESC_XUNLOCK(fdp); 1780} 1781 1782/* 1783 * Close any files on exec? 1784 */ 1785void 1786fdcloseexec(struct thread *td) 1787{ 1788 struct filedesc *fdp; 1789 int i; 1790 1791 /* Certain daemons might not have file descriptors. */ 1792 fdp = td->td_proc->p_fd; 1793 if (fdp == NULL) 1794 return; 1795 1796 FILEDESC_XLOCK(fdp); 1797 1798 /* 1799 * We cannot cache fd_ofiles or fd_ofileflags since operations 1800 * may block and rip them out from under us. 1801 */ 1802 for (i = 0; i <= fdp->fd_lastfile; i++) { 1803 if (fdp->fd_ofiles[i] != NULL && 1804 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE || 1805 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) { 1806 struct file *fp; 1807 1808 knote_fdclose(td, i); 1809 /* 1810 * NULL-out descriptor prior to close to avoid 1811 * a race while close blocks. 1812 */ 1813 fp = fdp->fd_ofiles[i]; 1814 fdp->fd_ofiles[i] = NULL; 1815 fdp->fd_ofileflags[i] = 0; 1816 fdunused(fdp, i); 1817 if (fp->f_type == DTYPE_MQUEUE) 1818 mq_fdclose(td, i, fp); 1819 FILEDESC_XUNLOCK(fdp); 1820 (void) closef(fp, td); 1821 FILEDESC_XLOCK(fdp); 1822 } 1823 } 1824 FILEDESC_XUNLOCK(fdp); 1825} 1826 1827/* 1828 * It is unsafe for set[ug]id processes to be started with file 1829 * descriptors 0..2 closed, as these descriptors are given implicit 1830 * significance in the Standard C library. fdcheckstd() will create a 1831 * descriptor referencing /dev/null for each of stdin, stdout, and 1832 * stderr that is not already open. 1833 */ 1834int 1835fdcheckstd(struct thread *td) 1836{ 1837 struct filedesc *fdp; 1838 register_t retval, save; 1839 int i, error, devnull; 1840 1841 fdp = td->td_proc->p_fd; 1842 if (fdp == NULL) 1843 return (0); 1844 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 1845 devnull = -1; 1846 error = 0; 1847 for (i = 0; i < 3; i++) { 1848 if (fdp->fd_ofiles[i] != NULL) 1849 continue; 1850 if (devnull < 0) { 1851 save = td->td_retval[0]; 1852 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 1853 O_RDWR, 0); 1854 devnull = td->td_retval[0]; 1855 KASSERT(devnull == i, ("oof, we didn't get our fd")); 1856 td->td_retval[0] = save; 1857 if (error) 1858 break; 1859 } else { 1860 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 1861 if (error != 0) 1862 break; 1863 } 1864 } 1865 return (error); 1866} 1867 1868/* 1869 * Internal form of close. Decrement reference count on file structure. 1870 * Note: td may be NULL when closing a file that was being passed in a 1871 * message. 1872 * 1873 * XXXRW: Giant is not required for the caller, but often will be held; this 1874 * makes it moderately likely the Giant will be recursed in the VFS case. 1875 */ 1876int 1877closef(struct file *fp, struct thread *td) 1878{ 1879 struct vnode *vp; 1880 struct flock lf; 1881 struct filedesc_to_leader *fdtol; 1882 struct filedesc *fdp; 1883 1884 /* 1885 * POSIX record locking dictates that any close releases ALL 1886 * locks owned by this process. This is handled by setting 1887 * a flag in the unlock to free ONLY locks obeying POSIX 1888 * semantics, and not to free BSD-style file locks. 1889 * If the descriptor was in a message, POSIX-style locks 1890 * aren't passed with the descriptor, and the thread pointer 1891 * will be NULL. Callers should be careful only to pass a 1892 * NULL thread pointer when there really is no owning 1893 * context that might have locks, or the locks will be 1894 * leaked. 1895 */ 1896 if (fp->f_type == DTYPE_VNODE && td != NULL) { 1897 int vfslocked; 1898 1899 vp = fp->f_vnode; 1900 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1901 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1902 lf.l_whence = SEEK_SET; 1903 lf.l_start = 0; 1904 lf.l_len = 0; 1905 lf.l_type = F_UNLCK; 1906 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 1907 F_UNLCK, &lf, F_POSIX); 1908 } 1909 fdtol = td->td_proc->p_fdtol; 1910 if (fdtol != NULL) { 1911 /* 1912 * Handle special case where file descriptor table is 1913 * shared between multiple process leaders. 1914 */ 1915 fdp = td->td_proc->p_fd; 1916 FILEDESC_XLOCK(fdp); 1917 for (fdtol = fdtol->fdl_next; 1918 fdtol != td->td_proc->p_fdtol; 1919 fdtol = fdtol->fdl_next) { 1920 if ((fdtol->fdl_leader->p_flag & 1921 P_ADVLOCK) == 0) 1922 continue; 1923 fdtol->fdl_holdcount++; 1924 FILEDESC_XUNLOCK(fdp); 1925 lf.l_whence = SEEK_SET; 1926 lf.l_start = 0; 1927 lf.l_len = 0; 1928 lf.l_type = F_UNLCK; 1929 vp = fp->f_vnode; 1930 (void) VOP_ADVLOCK(vp, 1931 (caddr_t)fdtol->fdl_leader, 1932 F_UNLCK, &lf, F_POSIX); 1933 FILEDESC_XLOCK(fdp); 1934 fdtol->fdl_holdcount--; 1935 if (fdtol->fdl_holdcount == 0 && 1936 fdtol->fdl_wakeup != 0) { 1937 fdtol->fdl_wakeup = 0; 1938 wakeup(fdtol); 1939 } 1940 } 1941 FILEDESC_XUNLOCK(fdp); 1942 } 1943 VFS_UNLOCK_GIANT(vfslocked); 1944 } 1945 return (fdrop(fp, td)); 1946} 1947 1948/* 1949 * Initialize the file pointer with the specified properties. 1950 * 1951 * The ops are set with release semantics to be certain that the flags, type, 1952 * and data are visible when ops is. This is to prevent ops methods from being 1953 * called with bad data. 1954 */ 1955void 1956finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 1957{ 1958 fp->f_data = data; 1959 fp->f_flag = flag; 1960 fp->f_type = type; 1961 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 1962} 1963 1964 1965/* 1966 * Extract the file pointer associated with the specified descriptor for the 1967 * current user process. 1968 * 1969 * If the descriptor doesn't exist, EBADF is returned. 1970 * 1971 * If the descriptor exists but doesn't match 'flags' then return EBADF for 1972 * read attempts and EINVAL for write attempts. 1973 * 1974 * If 'hold' is set (non-zero) the file's refcount will be bumped on return. 1975 * It should be dropped with fdrop(). If it is not set, then the refcount 1976 * will not be bumped however the thread's filedesc struct will be returned 1977 * locked (for fgetsock). 1978 * 1979 * If an error occured the non-zero error is returned and *fpp is set to 1980 * NULL. Otherwise *fpp is set and zero is returned. 1981 */ 1982static __inline int 1983_fget(struct thread *td, int fd, struct file **fpp, int flags, int hold) 1984{ 1985 struct filedesc *fdp; 1986 struct file *fp; 1987 1988 *fpp = NULL; 1989 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 1990 return (EBADF); 1991 FILEDESC_SLOCK(fdp); 1992 if ((fp = fget_locked(fdp, fd)) == NULL || fp->f_ops == &badfileops) { 1993 FILEDESC_SUNLOCK(fdp); 1994 return (EBADF); 1995 } 1996 1997 /* 1998 * FREAD and FWRITE failure return EBADF as per POSIX. 1999 * 2000 * Only one flag, or 0, may be specified. 2001 */ 2002 if (flags == FREAD && (fp->f_flag & FREAD) == 0) { 2003 FILEDESC_SUNLOCK(fdp); 2004 return (EBADF); 2005 } 2006 if (flags == FWRITE && (fp->f_flag & FWRITE) == 0) { 2007 FILEDESC_SUNLOCK(fdp); 2008 return (EBADF); 2009 } 2010 if (hold) { 2011 fhold(fp); 2012 FILEDESC_SUNLOCK(fdp); 2013 } 2014 *fpp = fp; 2015 return (0); 2016} 2017 2018int 2019fget(struct thread *td, int fd, struct file **fpp) 2020{ 2021 2022 return(_fget(td, fd, fpp, 0, 1)); 2023} 2024 2025int 2026fget_read(struct thread *td, int fd, struct file **fpp) 2027{ 2028 2029 return(_fget(td, fd, fpp, FREAD, 1)); 2030} 2031 2032int 2033fget_write(struct thread *td, int fd, struct file **fpp) 2034{ 2035 2036 return(_fget(td, fd, fpp, FWRITE, 1)); 2037} 2038 2039/* 2040 * Like fget() but loads the underlying vnode, or returns an error if the 2041 * descriptor does not represent a vnode. Note that pipes use vnodes but 2042 * never have VM objects. The returned vnode will be vref()'d. 2043 * 2044 * XXX: what about the unused flags ? 2045 */ 2046static __inline int 2047_fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags) 2048{ 2049 struct file *fp; 2050 int error; 2051 2052 *vpp = NULL; 2053 if ((error = _fget(td, fd, &fp, 0, 0)) != 0) 2054 return (error); 2055 if (fp->f_vnode == NULL) { 2056 error = EINVAL; 2057 } else { 2058 *vpp = fp->f_vnode; 2059 vref(*vpp); 2060 } 2061 FILEDESC_SUNLOCK(td->td_proc->p_fd); 2062 return (error); 2063} 2064 2065int 2066fgetvp(struct thread *td, int fd, struct vnode **vpp) 2067{ 2068 2069 return (_fgetvp(td, fd, vpp, 0)); 2070} 2071 2072int 2073fgetvp_read(struct thread *td, int fd, struct vnode **vpp) 2074{ 2075 2076 return (_fgetvp(td, fd, vpp, FREAD)); 2077} 2078 2079#ifdef notyet 2080int 2081fgetvp_write(struct thread *td, int fd, struct vnode **vpp) 2082{ 2083 2084 return (_fgetvp(td, fd, vpp, FWRITE)); 2085} 2086#endif 2087 2088/* 2089 * Like fget() but loads the underlying socket, or returns an error if the 2090 * descriptor does not represent a socket. 2091 * 2092 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2093 * in the future. 2094 * 2095 * XXXRW: fgetsock() and fputsock() are deprecated, as consumers should rely 2096 * on their file descriptor reference to prevent the socket from being free'd 2097 * during use. 2098 */ 2099int 2100fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp) 2101{ 2102 struct file *fp; 2103 int error; 2104 2105 *spp = NULL; 2106 if (fflagp != NULL) 2107 *fflagp = 0; 2108 if ((error = _fget(td, fd, &fp, 0, 0)) != 0) 2109 return (error); 2110 if (fp->f_type != DTYPE_SOCKET) { 2111 error = ENOTSOCK; 2112 } else { 2113 *spp = fp->f_data; 2114 if (fflagp) 2115 *fflagp = fp->f_flag; 2116 SOCK_LOCK(*spp); 2117 soref(*spp); 2118 SOCK_UNLOCK(*spp); 2119 } 2120 FILEDESC_SUNLOCK(td->td_proc->p_fd); 2121 return (error); 2122} 2123 2124/* 2125 * Drop the reference count on the socket and XXX release the SX lock in the 2126 * future. The last reference closes the socket. 2127 * 2128 * XXXRW: fputsock() is deprecated, see comment for fgetsock(). 2129 */ 2130void 2131fputsock(struct socket *so) 2132{ 2133 2134 ACCEPT_LOCK(); 2135 SOCK_LOCK(so); 2136 sorele(so); 2137} 2138 2139/* 2140 * Handle the last reference to a file being closed. 2141 */ 2142int 2143_fdrop(struct file *fp, struct thread *td) 2144{ 2145 int error; 2146 2147 error = 0; 2148 if (fp->f_count != 0) 2149 panic("fdrop: count %d", fp->f_count); 2150 if (fp->f_ops != &badfileops) 2151 error = fo_close(fp, td); 2152 atomic_subtract_int(&openfiles, 1); 2153 crfree(fp->f_cred); 2154 uma_zfree(file_zone, fp); 2155 2156 return (error); 2157} 2158 2159/* 2160 * Apply an advisory lock on a file descriptor. 2161 * 2162 * Just attempt to get a record lock of the requested type on the entire file 2163 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2164 */ 2165#ifndef _SYS_SYSPROTO_H_ 2166struct flock_args { 2167 int fd; 2168 int how; 2169}; 2170#endif 2171/* ARGSUSED */ 2172int 2173flock(struct thread *td, struct flock_args *uap) 2174{ 2175 struct file *fp; 2176 struct vnode *vp; 2177 struct flock lf; 2178 int vfslocked; 2179 int error; 2180 2181 if ((error = fget(td, uap->fd, &fp)) != 0) 2182 return (error); 2183 if (fp->f_type != DTYPE_VNODE) { 2184 fdrop(fp, td); 2185 return (EOPNOTSUPP); 2186 } 2187 2188 vp = fp->f_vnode; 2189 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2190 lf.l_whence = SEEK_SET; 2191 lf.l_start = 0; 2192 lf.l_len = 0; 2193 if (uap->how & LOCK_UN) { 2194 lf.l_type = F_UNLCK; 2195 atomic_clear_int(&fp->f_flag, FHASLOCK); 2196 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2197 goto done2; 2198 } 2199 if (uap->how & LOCK_EX) 2200 lf.l_type = F_WRLCK; 2201 else if (uap->how & LOCK_SH) 2202 lf.l_type = F_RDLCK; 2203 else { 2204 error = EBADF; 2205 goto done2; 2206 } 2207 atomic_set_int(&fp->f_flag, FHASLOCK); 2208 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2209 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2210done2: 2211 fdrop(fp, td); 2212 VFS_UNLOCK_GIANT(vfslocked); 2213 return (error); 2214} 2215/* 2216 * Duplicate the specified descriptor to a free descriptor. 2217 */ 2218int 2219dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error) 2220{ 2221 struct file *wfp; 2222 struct file *fp; 2223 2224 /* 2225 * If the to-be-dup'd fd number is greater than the allowed number 2226 * of file descriptors, or the fd to be dup'd has already been 2227 * closed, then reject. 2228 */ 2229 FILEDESC_XLOCK(fdp); 2230 if (dfd < 0 || dfd >= fdp->fd_nfiles || 2231 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 2232 FILEDESC_XUNLOCK(fdp); 2233 return (EBADF); 2234 } 2235 2236 /* 2237 * There are two cases of interest here. 2238 * 2239 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2240 * 2241 * For ENXIO steal away the file structure from (dfd) and store it in 2242 * (indx). (dfd) is effectively closed by this operation. 2243 * 2244 * Any other error code is just returned. 2245 */ 2246 switch (error) { 2247 case ENODEV: 2248 /* 2249 * Check that the mode the file is being opened for is a 2250 * subset of the mode of the existing descriptor. 2251 */ 2252 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2253 FILEDESC_XUNLOCK(fdp); 2254 return (EACCES); 2255 } 2256 fp = fdp->fd_ofiles[indx]; 2257 fdp->fd_ofiles[indx] = wfp; 2258 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2259 if (fp == NULL) 2260 fdused(fdp, indx); 2261 fhold(wfp); 2262 FILEDESC_XUNLOCK(fdp); 2263 if (fp != NULL) 2264 /* 2265 * We now own the reference to fp that the ofiles[] 2266 * array used to own. Release it. 2267 */ 2268 fdrop(fp, td); 2269 return (0); 2270 2271 case ENXIO: 2272 /* 2273 * Steal away the file pointer from dfd and stuff it into indx. 2274 */ 2275 fp = fdp->fd_ofiles[indx]; 2276 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 2277 fdp->fd_ofiles[dfd] = NULL; 2278 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2279 fdp->fd_ofileflags[dfd] = 0; 2280 fdunused(fdp, dfd); 2281 if (fp == NULL) 2282 fdused(fdp, indx); 2283 FILEDESC_XUNLOCK(fdp); 2284 2285 /* 2286 * We now own the reference to fp that the ofiles[] array 2287 * used to own. Release it. 2288 */ 2289 if (fp != NULL) 2290 fdrop(fp, td); 2291 return (0); 2292 2293 default: 2294 FILEDESC_XUNLOCK(fdp); 2295 return (error); 2296 } 2297 /* NOTREACHED */ 2298} 2299 2300/* 2301 * Scan all active processes to see if any of them have a current or root 2302 * directory of `olddp'. If so, replace them with the new mount point. 2303 */ 2304void 2305mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2306{ 2307 struct filedesc *fdp; 2308 struct proc *p; 2309 int nrele; 2310 2311 if (vrefcnt(olddp) == 1) 2312 return; 2313 sx_slock(&allproc_lock); 2314 FOREACH_PROC_IN_SYSTEM(p) { 2315 fdp = fdhold(p); 2316 if (fdp == NULL) 2317 continue; 2318 nrele = 0; 2319 FILEDESC_XLOCK(fdp); 2320 if (fdp->fd_cdir == olddp) { 2321 vref(newdp); 2322 fdp->fd_cdir = newdp; 2323 nrele++; 2324 } 2325 if (fdp->fd_rdir == olddp) { 2326 vref(newdp); 2327 fdp->fd_rdir = newdp; 2328 nrele++; 2329 } 2330 FILEDESC_XUNLOCK(fdp); 2331 fddrop(fdp); 2332 while (nrele--) 2333 vrele(olddp); 2334 } 2335 sx_sunlock(&allproc_lock); 2336 if (rootvnode == olddp) { 2337 vrele(rootvnode); 2338 vref(newdp); 2339 rootvnode = newdp; 2340 } 2341} 2342 2343struct filedesc_to_leader * 2344filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2345{ 2346 struct filedesc_to_leader *fdtol; 2347 2348 MALLOC(fdtol, struct filedesc_to_leader *, 2349 sizeof(struct filedesc_to_leader), 2350 M_FILEDESC_TO_LEADER, 2351 M_WAITOK); 2352 fdtol->fdl_refcount = 1; 2353 fdtol->fdl_holdcount = 0; 2354 fdtol->fdl_wakeup = 0; 2355 fdtol->fdl_leader = leader; 2356 if (old != NULL) { 2357 FILEDESC_XLOCK(fdp); 2358 fdtol->fdl_next = old->fdl_next; 2359 fdtol->fdl_prev = old; 2360 old->fdl_next = fdtol; 2361 fdtol->fdl_next->fdl_prev = fdtol; 2362 FILEDESC_XUNLOCK(fdp); 2363 } else { 2364 fdtol->fdl_next = fdtol; 2365 fdtol->fdl_prev = fdtol; 2366 } 2367 return (fdtol); 2368} 2369 2370/* 2371 * Get file structures globally. 2372 */ 2373static int 2374sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2375{ 2376 struct xfile xf; 2377 struct filedesc *fdp; 2378 struct file *fp; 2379 struct proc *p; 2380 int error, n; 2381 2382 error = sysctl_wire_old_buffer(req, 0); 2383 if (error != 0) 2384 return (error); 2385 if (req->oldptr == NULL) { 2386 n = 0; 2387 sx_slock(&allproc_lock); 2388 FOREACH_PROC_IN_SYSTEM(p) { 2389 if (p->p_state == PRS_NEW) 2390 continue; 2391 fdp = fdhold(p); 2392 if (fdp == NULL) 2393 continue; 2394 /* overestimates sparse tables. */ 2395 if (fdp->fd_lastfile > 0) 2396 n += fdp->fd_lastfile; 2397 fddrop(fdp); 2398 } 2399 sx_sunlock(&allproc_lock); 2400 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2401 } 2402 error = 0; 2403 bzero(&xf, sizeof(xf)); 2404 xf.xf_size = sizeof(xf); 2405 sx_slock(&allproc_lock); 2406 FOREACH_PROC_IN_SYSTEM(p) { 2407 if (p->p_state == PRS_NEW) 2408 continue; 2409 PROC_LOCK(p); 2410 if (p_cansee(req->td, p) != 0) { 2411 PROC_UNLOCK(p); 2412 continue; 2413 } 2414 xf.xf_pid = p->p_pid; 2415 xf.xf_uid = p->p_ucred->cr_uid; 2416 PROC_UNLOCK(p); 2417 fdp = fdhold(p); 2418 if (fdp == NULL) 2419 continue; 2420 FILEDESC_SLOCK(fdp); 2421 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) { 2422 if ((fp = fdp->fd_ofiles[n]) == NULL) 2423 continue; 2424 xf.xf_fd = n; 2425 xf.xf_file = fp; 2426 xf.xf_data = fp->f_data; 2427 xf.xf_vnode = fp->f_vnode; 2428 xf.xf_type = fp->f_type; 2429 xf.xf_count = fp->f_count; 2430 xf.xf_msgcount = 0; 2431 xf.xf_offset = fp->f_offset; 2432 xf.xf_flag = fp->f_flag; 2433 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2434 if (error) 2435 break; 2436 } 2437 FILEDESC_SUNLOCK(fdp); 2438 fddrop(fdp); 2439 if (error) 2440 break; 2441 } 2442 sx_sunlock(&allproc_lock); 2443 return (error); 2444} 2445 2446SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2447 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2448 2449/* 2450 * Get per-process file descriptors for use by procstat(1), et al. 2451 */ 2452static int 2453sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 2454{ 2455 char *fullpath, *freepath; 2456 struct kinfo_file *kif; 2457 struct filedesc *fdp; 2458 int error, i, *name; 2459 struct socket *so; 2460 struct vnode *vp; 2461 struct file *fp; 2462 struct proc *p; 2463 int vfslocked; 2464 2465 name = (int *)arg1; 2466 if ((p = pfind((pid_t)name[0])) == NULL) 2467 return (ESRCH); 2468 if ((error = p_candebug(curthread, p))) { 2469 PROC_UNLOCK(p); 2470 return (error); 2471 } 2472 fdp = fdhold(p); 2473 PROC_UNLOCK(p); 2474 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 2475 FILEDESC_SLOCK(fdp); 2476 for (i = 0; i < fdp->fd_nfiles; i++) { 2477 if ((fp = fdp->fd_ofiles[i]) == NULL) 2478 continue; 2479 bzero(kif, sizeof(*kif)); 2480 kif->kf_structsize = sizeof(*kif); 2481 vp = NULL; 2482 so = NULL; 2483 kif->kf_fd = i; 2484 switch (fp->f_type) { 2485 case DTYPE_VNODE: 2486 kif->kf_type = KF_TYPE_VNODE; 2487 vp = fp->f_vnode; 2488 break; 2489 2490 case DTYPE_SOCKET: 2491 kif->kf_type = KF_TYPE_SOCKET; 2492 so = fp->f_data; 2493 break; 2494 2495 case DTYPE_PIPE: 2496 kif->kf_type = KF_TYPE_PIPE; 2497 break; 2498 2499 case DTYPE_FIFO: 2500 kif->kf_type = KF_TYPE_FIFO; 2501 vp = fp->f_vnode; 2502 vref(vp); 2503 break; 2504 2505 case DTYPE_KQUEUE: 2506 kif->kf_type = KF_TYPE_KQUEUE; 2507 break; 2508 2509 case DTYPE_CRYPTO: 2510 kif->kf_type = KF_TYPE_CRYPTO; 2511 break; 2512 2513 case DTYPE_MQUEUE: 2514 kif->kf_type = KF_TYPE_MQUEUE; 2515 break; 2516 2517 default: 2518 kif->kf_type = KF_TYPE_UNKNOWN; 2519 break; 2520 } 2521 kif->kf_ref_count = fp->f_count; 2522 if (fp->f_flag & FREAD) 2523 kif->kf_flags |= KF_FLAG_READ; 2524 if (fp->f_flag & FWRITE) 2525 kif->kf_flags |= KF_FLAG_WRITE; 2526 if (fp->f_flag & FAPPEND) 2527 kif->kf_flags |= KF_FLAG_APPEND; 2528 if (fp->f_flag & FASYNC) 2529 kif->kf_flags |= KF_FLAG_ASYNC; 2530 if (fp->f_flag & FFSYNC) 2531 kif->kf_flags |= KF_FLAG_FSYNC; 2532 if (fp->f_flag & FNONBLOCK) 2533 kif->kf_flags |= KF_FLAG_NONBLOCK; 2534 if (fp->f_flag & O_DIRECT) 2535 kif->kf_flags |= KF_FLAG_DIRECT; 2536 if (fp->f_flag & FHASLOCK) 2537 kif->kf_flags |= KF_FLAG_HASLOCK; 2538 kif->kf_offset = fp->f_offset; 2539 if (vp != NULL) { 2540 vref(vp); 2541 switch (vp->v_type) { 2542 case VNON: 2543 kif->kf_vnode_type = KF_VTYPE_VNON; 2544 break; 2545 case VREG: 2546 kif->kf_vnode_type = KF_VTYPE_VREG; 2547 break; 2548 case VDIR: 2549 kif->kf_vnode_type = KF_VTYPE_VDIR; 2550 break; 2551 case VBLK: 2552 kif->kf_vnode_type = KF_VTYPE_VBLK; 2553 break; 2554 case VCHR: 2555 kif->kf_vnode_type = KF_VTYPE_VCHR; 2556 break; 2557 case VLNK: 2558 kif->kf_vnode_type = KF_VTYPE_VLNK; 2559 break; 2560 case VSOCK: 2561 kif->kf_vnode_type = KF_VTYPE_VSOCK; 2562 break; 2563 case VFIFO: 2564 kif->kf_vnode_type = KF_VTYPE_VFIFO; 2565 break; 2566 case VBAD: 2567 kif->kf_vnode_type = KF_VTYPE_VBAD; 2568 break; 2569 default: 2570 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 2571 break; 2572 } 2573 /* 2574 * It is OK to drop the filedesc lock here as we will 2575 * re-validate and re-evaluate its properties when 2576 * the loop continues. 2577 */ 2578 freepath = NULL; 2579 fullpath = "-"; 2580 FILEDESC_SUNLOCK(fdp); 2581 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2582 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2583 vn_fullpath(curthread, vp, &fullpath, &freepath); 2584 vput(vp); 2585 VFS_UNLOCK_GIANT(vfslocked); 2586 strlcpy(kif->kf_path, fullpath, 2587 sizeof(kif->kf_path)); 2588 if (freepath != NULL) 2589 free(freepath, M_TEMP); 2590 FILEDESC_SLOCK(fdp); 2591 } 2592 if (so != NULL) { 2593 struct sockaddr *sa; 2594 2595 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 2596 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 2597 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 2598 free(sa, M_SONAME); 2599 } 2600 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 2601 == 00 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 2602 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 2603 free(sa, M_SONAME); 2604 } 2605 kif->kf_sock_domain = 2606 so->so_proto->pr_domain->dom_family; 2607 kif->kf_sock_type = so->so_type; 2608 kif->kf_sock_protocol = so->so_proto->pr_protocol; 2609 } 2610 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2611 if (error) 2612 break; 2613 } 2614 FILEDESC_SUNLOCK(fdp); 2615 fddrop(fdp); 2616 free(kif, M_TEMP); 2617 return (0); 2618} 2619 2620static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD, 2621 sysctl_kern_proc_filedesc, "Process filedesc entries"); 2622 2623#ifdef DDB 2624/* 2625 * For the purposes of debugging, generate a human-readable string for the 2626 * file type. 2627 */ 2628static const char * 2629file_type_to_name(short type) 2630{ 2631 2632 switch (type) { 2633 case 0: 2634 return ("zero"); 2635 case DTYPE_VNODE: 2636 return ("vnod"); 2637 case DTYPE_SOCKET: 2638 return ("sock"); 2639 case DTYPE_PIPE: 2640 return ("pipe"); 2641 case DTYPE_FIFO: 2642 return ("fifo"); 2643 case DTYPE_KQUEUE: 2644 return ("kque"); 2645 case DTYPE_CRYPTO: 2646 return ("crpt"); 2647 case DTYPE_MQUEUE: 2648 return ("mque"); 2649 case DTYPE_SHM: 2650 return ("shm"); 2651 default: 2652 return ("unkn"); 2653 } 2654} 2655 2656/* 2657 * For the purposes of debugging, identify a process (if any, perhaps one of 2658 * many) that references the passed file in its file descriptor array. Return 2659 * NULL if none. 2660 */ 2661static struct proc * 2662file_to_first_proc(struct file *fp) 2663{ 2664 struct filedesc *fdp; 2665 struct proc *p; 2666 int n; 2667 2668 FOREACH_PROC_IN_SYSTEM(p) { 2669 if (p->p_state == PRS_NEW) 2670 continue; 2671 fdp = p->p_fd; 2672 if (fdp == NULL) 2673 continue; 2674 for (n = 0; n < fdp->fd_nfiles; n++) { 2675 if (fp == fdp->fd_ofiles[n]) 2676 return (p); 2677 } 2678 } 2679 return (NULL); 2680} 2681 2682static void 2683db_print_file(struct file *fp, int header) 2684{ 2685 struct proc *p; 2686 2687 if (header) 2688 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 2689 "File", "Type", "Data", "Flag", "GCFl", "Count", 2690 "MCount", "Vnode", "FPID", "FCmd"); 2691 p = file_to_first_proc(fp); 2692 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 2693 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 2694 0, fp->f_count, 0, fp->f_vnode, 2695 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 2696} 2697 2698DB_SHOW_COMMAND(file, db_show_file) 2699{ 2700 struct file *fp; 2701 2702 if (!have_addr) { 2703 db_printf("usage: show file <addr>\n"); 2704 return; 2705 } 2706 fp = (struct file *)addr; 2707 db_print_file(fp, 1); 2708} 2709 2710DB_SHOW_COMMAND(files, db_show_files) 2711{ 2712 struct filedesc *fdp; 2713 struct file *fp; 2714 struct proc *p; 2715 int header; 2716 int n; 2717 2718 header = 1; 2719 FOREACH_PROC_IN_SYSTEM(p) { 2720 if (p->p_state == PRS_NEW) 2721 continue; 2722 if ((fdp = p->p_fd) == NULL) 2723 continue; 2724 for (n = 0; n < fdp->fd_nfiles; ++n) { 2725 if ((fp = fdp->fd_ofiles[n]) == NULL) 2726 continue; 2727 db_print_file(fp, header); 2728 header = 0; 2729 } 2730 } 2731} 2732#endif 2733 2734SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 2735 &maxfilesperproc, 0, "Maximum files allowed open per process"); 2736 2737SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 2738 &maxfiles, 0, "Maximum number of files"); 2739 2740SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 2741 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 2742 2743/* ARGSUSED*/ 2744static void 2745filelistinit(void *dummy) 2746{ 2747 2748 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 2749 NULL, NULL, UMA_ALIGN_PTR, 0); 2750 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 2751 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 2752} 2753SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL) 2754 2755/*-------------------------------------------------------------------*/ 2756 2757static int 2758badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) 2759{ 2760 2761 return (EBADF); 2762} 2763 2764static int 2765badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) 2766{ 2767 2768 return (EINVAL); 2769} 2770 2771static int 2772badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) 2773{ 2774 2775 return (EBADF); 2776} 2777 2778static int 2779badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) 2780{ 2781 2782 return (0); 2783} 2784 2785static int 2786badfo_kqfilter(struct file *fp, struct knote *kn) 2787{ 2788 2789 return (EBADF); 2790} 2791 2792static int 2793badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) 2794{ 2795 2796 return (EBADF); 2797} 2798 2799static int 2800badfo_close(struct file *fp, struct thread *td) 2801{ 2802 2803 return (EBADF); 2804} 2805 2806struct fileops badfileops = { 2807 .fo_read = badfo_readwrite, 2808 .fo_write = badfo_readwrite, 2809 .fo_truncate = badfo_truncate, 2810 .fo_ioctl = badfo_ioctl, 2811 .fo_poll = badfo_poll, 2812 .fo_kqfilter = badfo_kqfilter, 2813 .fo_stat = badfo_stat, 2814 .fo_close = badfo_close, 2815}; 2816 2817 2818/*-------------------------------------------------------------------*/ 2819 2820/* 2821 * File Descriptor pseudo-device driver (/dev/fd/). 2822 * 2823 * Opening minor device N dup()s the file (if any) connected to file 2824 * descriptor N belonging to the calling process. Note that this driver 2825 * consists of only the ``open()'' routine, because all subsequent 2826 * references to this file will be direct to the other driver. 2827 * 2828 * XXX: we could give this one a cloning event handler if necessary. 2829 */ 2830 2831/* ARGSUSED */ 2832static int 2833fdopen(struct cdev *dev, int mode, int type, struct thread *td) 2834{ 2835 2836 /* 2837 * XXX Kludge: set curthread->td_dupfd to contain the value of the 2838 * the file descriptor being sought for duplication. The error 2839 * return ensures that the vnode for this device will be released 2840 * by vn_open. Open will detect this special error and take the 2841 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 2842 * will simply report the error. 2843 */ 2844 td->td_dupfd = dev2unit(dev); 2845 return (ENODEV); 2846} 2847 2848static struct cdevsw fildesc_cdevsw = { 2849 .d_version = D_VERSION, 2850 .d_flags = D_NEEDGIANT, 2851 .d_open = fdopen, 2852 .d_name = "FD", 2853}; 2854 2855static void 2856fildesc_drvinit(void *unused) 2857{ 2858 struct cdev *dev; 2859 2860 dev = make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "fd/0"); 2861 make_dev_alias(dev, "stdin"); 2862 dev = make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "fd/1"); 2863 make_dev_alias(dev, "stdout"); 2864 dev = make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "fd/2"); 2865 make_dev_alias(dev, "stderr"); 2866} 2867 2868SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL) 2869