Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_descrip.c
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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: releng/8.3/sys/kern/kern_descrip.c 229506 2012-01-04 16:51:04Z jhb $"); 39 40 #include "opt_compat.h" 41 #include "opt_ddb.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 47 #include <sys/conf.h> 48 #include <sys/domain.h> 49 #include <sys/fcntl.h> 50 #include <sys/file.h> 51 #include <sys/filedesc.h> 52 #include <sys/filio.h> 53 #include <sys/jail.h> 54 #include <sys/kernel.h> 55 #include <sys/limits.h> 56 #include <sys/lock.h> 57 #include <sys/malloc.h> 58 #include <sys/mount.h> 59 #include <sys/mqueue.h> 60 #include <sys/mutex.h> 61 #include <sys/namei.h> 62 #include <sys/priv.h> 63 #include <sys/proc.h> 64 #include <sys/protosw.h> 65 #include <sys/resourcevar.h> 66 #include <sys/signalvar.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sx.h> 70 #include <sys/syscallsubr.h> 71 #include <sys/sysctl.h> 72 #include <sys/sysproto.h> 73 #include <sys/tty.h> 74 #include <sys/unistd.h> 75 #include <sys/user.h> 76 #include <sys/vnode.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <net/vnet.h> 82 83 #include <security/audit/audit.h> 84 85 #include <vm/uma.h> 86 87 #include <ddb/ddb.h> 88 89 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 90 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 91 "file desc to leader structures"); 92 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 93 94 static uma_zone_t file_zone; 95 96 97 /* Flags for do_dup() */ 98 #define DUP_FIXED 0x1 /* Force fixed allocation */ 99 #define DUP_FCNTL 0x2 /* fcntl()-style errors */ 100 101 static int do_dup(struct thread *td, int flags, int old, int new, 102 register_t *retval); 103 static int fd_first_free(struct filedesc *, int, int); 104 static int fd_last_used(struct filedesc *, int, int); 105 static void fdgrowtable(struct filedesc *, int); 106 static void fdunused(struct filedesc *fdp, int fd); 107 static void fdused(struct filedesc *fdp, int fd); 108 109 /* 110 * A process is initially started out with NDFILE descriptors stored within 111 * this structure, selected to be enough for typical applications based on 112 * the historical limit of 20 open files (and the usage of descriptors by 113 * shells). If these descriptors are exhausted, a larger descriptor table 114 * may be allocated, up to a process' resource limit; the internal arrays 115 * are then unused. 116 */ 117 #define NDFILE 20 118 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 119 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 120 #define NDSLOT(x) ((x) / NDENTRIES) 121 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 122 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 123 124 /* 125 * Storage required per open file descriptor. 126 */ 127 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 128 129 /* 130 * Storage to hold unused ofiles that need to be reclaimed. 131 */ 132 struct freetable { 133 struct file **ft_table; 134 SLIST_ENTRY(freetable) ft_next; 135 }; 136 137 /* 138 * Basic allocation of descriptors: 139 * one of the above, plus arrays for NDFILE descriptors. 140 */ 141 struct filedesc0 { 142 struct filedesc fd_fd; 143 /* 144 * ofiles which need to be reclaimed on free. 145 */ 146 SLIST_HEAD(,freetable) fd_free; 147 /* 148 * These arrays are used when the number of open files is 149 * <= NDFILE, and are then pointed to by the pointers above. 150 */ 151 struct file *fd_dfiles[NDFILE]; 152 char fd_dfileflags[NDFILE]; 153 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 154 }; 155 156 /* 157 * Descriptor management. 158 */ 159 volatile int openfiles; /* actual number of open files */ 160 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 161 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 162 163 /* A mutex to protect the association between a proc and filedesc. */ 164 static struct mtx fdesc_mtx; 165 166 /* 167 * Find the first zero bit in the given bitmap, starting at low and not 168 * exceeding size - 1. 169 */ 170 static int 171 fd_first_free(struct filedesc *fdp, int low, int size) 172 { 173 NDSLOTTYPE *map = fdp->fd_map; 174 NDSLOTTYPE mask; 175 int off, maxoff; 176 177 if (low >= size) 178 return (low); 179 180 off = NDSLOT(low); 181 if (low % NDENTRIES) { 182 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 183 if ((mask &= ~map[off]) != 0UL) 184 return (off * NDENTRIES + ffsl(mask) - 1); 185 ++off; 186 } 187 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 188 if (map[off] != ~0UL) 189 return (off * NDENTRIES + ffsl(~map[off]) - 1); 190 return (size); 191 } 192 193 /* 194 * Find the highest non-zero bit in the given bitmap, starting at low and 195 * not exceeding size - 1. 196 */ 197 static int 198 fd_last_used(struct filedesc *fdp, int low, int size) 199 { 200 NDSLOTTYPE *map = fdp->fd_map; 201 NDSLOTTYPE mask; 202 int off, minoff; 203 204 if (low >= size) 205 return (-1); 206 207 off = NDSLOT(size); 208 if (size % NDENTRIES) { 209 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 210 if ((mask &= map[off]) != 0) 211 return (off * NDENTRIES + flsl(mask) - 1); 212 --off; 213 } 214 for (minoff = NDSLOT(low); off >= minoff; --off) 215 if (map[off] != 0) 216 return (off * NDENTRIES + flsl(map[off]) - 1); 217 return (low - 1); 218 } 219 220 static int 221 fdisused(struct filedesc *fdp, int fd) 222 { 223 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 224 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 225 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 226 } 227 228 /* 229 * Mark a file descriptor as used. 230 */ 231 static void 232 fdused(struct filedesc *fdp, int fd) 233 { 234 235 FILEDESC_XLOCK_ASSERT(fdp); 236 KASSERT(!fdisused(fdp, fd), 237 ("fd already used")); 238 239 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 240 if (fd > fdp->fd_lastfile) 241 fdp->fd_lastfile = fd; 242 if (fd == fdp->fd_freefile) 243 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 244 } 245 246 /* 247 * Mark a file descriptor as unused. 248 */ 249 static void 250 fdunused(struct filedesc *fdp, int fd) 251 { 252 253 FILEDESC_XLOCK_ASSERT(fdp); 254 KASSERT(fdisused(fdp, fd), 255 ("fd is already unused")); 256 KASSERT(fdp->fd_ofiles[fd] == NULL, 257 ("fd is still in use")); 258 259 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 260 if (fd < fdp->fd_freefile) 261 fdp->fd_freefile = fd; 262 if (fd == fdp->fd_lastfile) 263 fdp->fd_lastfile = fd_last_used(fdp, 0, fd); 264 } 265 266 /* 267 * System calls on descriptors. 268 */ 269 #ifndef _SYS_SYSPROTO_H_ 270 struct getdtablesize_args { 271 int dummy; 272 }; 273 #endif 274 /* ARGSUSED */ 275 int 276 getdtablesize(struct thread *td, struct getdtablesize_args *uap) 277 { 278 struct proc *p = td->td_proc; 279 280 PROC_LOCK(p); 281 td->td_retval[0] = 282 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 283 PROC_UNLOCK(p); 284 return (0); 285 } 286 287 /* 288 * Duplicate a file descriptor to a particular value. 289 * 290 * Note: keep in mind that a potential race condition exists when closing 291 * descriptors from a shared descriptor table (via rfork). 292 */ 293 #ifndef _SYS_SYSPROTO_H_ 294 struct dup2_args { 295 u_int from; 296 u_int to; 297 }; 298 #endif 299 /* ARGSUSED */ 300 int 301 dup2(struct thread *td, struct dup2_args *uap) 302 { 303 304 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 305 td->td_retval)); 306 } 307 308 /* 309 * Duplicate a file descriptor. 310 */ 311 #ifndef _SYS_SYSPROTO_H_ 312 struct dup_args { 313 u_int fd; 314 }; 315 #endif 316 /* ARGSUSED */ 317 int 318 dup(struct thread *td, struct dup_args *uap) 319 { 320 321 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval)); 322 } 323 324 /* 325 * The file control system call. 326 */ 327 #ifndef _SYS_SYSPROTO_H_ 328 struct fcntl_args { 329 int fd; 330 int cmd; 331 long arg; 332 }; 333 #endif 334 /* ARGSUSED */ 335 int 336 fcntl(struct thread *td, struct fcntl_args *uap) 337 { 338 struct flock fl; 339 struct oflock ofl; 340 intptr_t arg; 341 int error; 342 int cmd; 343 344 error = 0; 345 cmd = uap->cmd; 346 switch (uap->cmd) { 347 case F_OGETLK: 348 case F_OSETLK: 349 case F_OSETLKW: 350 /* 351 * Convert old flock structure to new. 352 */ 353 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl)); 354 fl.l_start = ofl.l_start; 355 fl.l_len = ofl.l_len; 356 fl.l_pid = ofl.l_pid; 357 fl.l_type = ofl.l_type; 358 fl.l_whence = ofl.l_whence; 359 fl.l_sysid = 0; 360 361 switch (uap->cmd) { 362 case F_OGETLK: 363 cmd = F_GETLK; 364 break; 365 case F_OSETLK: 366 cmd = F_SETLK; 367 break; 368 case F_OSETLKW: 369 cmd = F_SETLKW; 370 break; 371 } 372 arg = (intptr_t)&fl; 373 break; 374 case F_GETLK: 375 case F_SETLK: 376 case F_SETLKW: 377 case F_SETLK_REMOTE: 378 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl)); 379 arg = (intptr_t)&fl; 380 break; 381 default: 382 arg = uap->arg; 383 break; 384 } 385 if (error) 386 return (error); 387 error = kern_fcntl(td, uap->fd, cmd, arg); 388 if (error) 389 return (error); 390 if (uap->cmd == F_OGETLK) { 391 ofl.l_start = fl.l_start; 392 ofl.l_len = fl.l_len; 393 ofl.l_pid = fl.l_pid; 394 ofl.l_type = fl.l_type; 395 ofl.l_whence = fl.l_whence; 396 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl)); 397 } else if (uap->cmd == F_GETLK) { 398 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl)); 399 } 400 return (error); 401 } 402 403 static inline struct file * 404 fdtofp(int fd, struct filedesc *fdp) 405 { 406 struct file *fp; 407 408 FILEDESC_LOCK_ASSERT(fdp); 409 if ((unsigned)fd >= fdp->fd_nfiles || 410 (fp = fdp->fd_ofiles[fd]) == NULL) 411 return (NULL); 412 return (fp); 413 } 414 415 int 416 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 417 { 418 struct filedesc *fdp; 419 struct flock *flp; 420 struct file *fp; 421 struct proc *p; 422 char *pop; 423 struct vnode *vp; 424 int error, flg, tmp; 425 int vfslocked; 426 u_int old, new; 427 uint64_t bsize; 428 429 vfslocked = 0; 430 error = 0; 431 flg = F_POSIX; 432 p = td->td_proc; 433 fdp = p->p_fd; 434 435 switch (cmd) { 436 case F_DUPFD: 437 tmp = arg; 438 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval); 439 break; 440 441 case F_DUP2FD: 442 tmp = arg; 443 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval); 444 break; 445 446 case F_GETFD: 447 FILEDESC_SLOCK(fdp); 448 if ((fp = fdtofp(fd, fdp)) == NULL) { 449 FILEDESC_SUNLOCK(fdp); 450 error = EBADF; 451 break; 452 } 453 pop = &fdp->fd_ofileflags[fd]; 454 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 455 FILEDESC_SUNLOCK(fdp); 456 break; 457 458 case F_SETFD: 459 FILEDESC_XLOCK(fdp); 460 if ((fp = fdtofp(fd, fdp)) == NULL) { 461 FILEDESC_XUNLOCK(fdp); 462 error = EBADF; 463 break; 464 } 465 pop = &fdp->fd_ofileflags[fd]; 466 *pop = (*pop &~ UF_EXCLOSE) | 467 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 468 FILEDESC_XUNLOCK(fdp); 469 break; 470 471 case F_GETFL: 472 FILEDESC_SLOCK(fdp); 473 if ((fp = fdtofp(fd, fdp)) == NULL) { 474 FILEDESC_SUNLOCK(fdp); 475 error = EBADF; 476 break; 477 } 478 td->td_retval[0] = OFLAGS(fp->f_flag); 479 FILEDESC_SUNLOCK(fdp); 480 break; 481 482 case F_SETFL: 483 FILEDESC_SLOCK(fdp); 484 if ((fp = fdtofp(fd, fdp)) == NULL) { 485 FILEDESC_SUNLOCK(fdp); 486 error = EBADF; 487 break; 488 } 489 fhold(fp); 490 FILEDESC_SUNLOCK(fdp); 491 do { 492 tmp = flg = fp->f_flag; 493 tmp &= ~FCNTLFLAGS; 494 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 495 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 496 tmp = fp->f_flag & FNONBLOCK; 497 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 498 if (error) { 499 fdrop(fp, td); 500 break; 501 } 502 tmp = fp->f_flag & FASYNC; 503 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 504 if (error == 0) { 505 fdrop(fp, td); 506 break; 507 } 508 atomic_clear_int(&fp->f_flag, FNONBLOCK); 509 tmp = 0; 510 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 511 fdrop(fp, td); 512 break; 513 514 case F_GETOWN: 515 FILEDESC_SLOCK(fdp); 516 if ((fp = fdtofp(fd, fdp)) == NULL) { 517 FILEDESC_SUNLOCK(fdp); 518 error = EBADF; 519 break; 520 } 521 fhold(fp); 522 FILEDESC_SUNLOCK(fdp); 523 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 524 if (error == 0) 525 td->td_retval[0] = tmp; 526 fdrop(fp, td); 527 break; 528 529 case F_SETOWN: 530 FILEDESC_SLOCK(fdp); 531 if ((fp = fdtofp(fd, fdp)) == NULL) { 532 FILEDESC_SUNLOCK(fdp); 533 error = EBADF; 534 break; 535 } 536 fhold(fp); 537 FILEDESC_SUNLOCK(fdp); 538 tmp = arg; 539 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 540 fdrop(fp, td); 541 break; 542 543 case F_SETLK_REMOTE: 544 error = priv_check(td, PRIV_NFS_LOCKD); 545 if (error) 546 return (error); 547 flg = F_REMOTE; 548 goto do_setlk; 549 550 case F_SETLKW: 551 flg |= F_WAIT; 552 /* FALLTHROUGH F_SETLK */ 553 554 case F_SETLK: 555 do_setlk: 556 FILEDESC_SLOCK(fdp); 557 if ((fp = fdtofp(fd, fdp)) == NULL) { 558 FILEDESC_SUNLOCK(fdp); 559 error = EBADF; 560 break; 561 } 562 if (fp->f_type != DTYPE_VNODE) { 563 FILEDESC_SUNLOCK(fdp); 564 error = EBADF; 565 break; 566 } 567 flp = (struct flock *)arg; 568 if (flp->l_whence == SEEK_CUR) { 569 if (fp->f_offset < 0 || 570 (flp->l_start > 0 && 571 fp->f_offset > OFF_MAX - flp->l_start)) { 572 FILEDESC_SUNLOCK(fdp); 573 error = EOVERFLOW; 574 break; 575 } 576 flp->l_start += fp->f_offset; 577 } 578 579 /* 580 * VOP_ADVLOCK() may block. 581 */ 582 fhold(fp); 583 FILEDESC_SUNLOCK(fdp); 584 vp = fp->f_vnode; 585 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 586 switch (flp->l_type) { 587 case F_RDLCK: 588 if ((fp->f_flag & FREAD) == 0) { 589 error = EBADF; 590 break; 591 } 592 PROC_LOCK(p->p_leader); 593 p->p_leader->p_flag |= P_ADVLOCK; 594 PROC_UNLOCK(p->p_leader); 595 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 596 flp, flg); 597 break; 598 case F_WRLCK: 599 if ((fp->f_flag & FWRITE) == 0) { 600 error = EBADF; 601 break; 602 } 603 PROC_LOCK(p->p_leader); 604 p->p_leader->p_flag |= P_ADVLOCK; 605 PROC_UNLOCK(p->p_leader); 606 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 607 flp, flg); 608 break; 609 case F_UNLCK: 610 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 611 flp, flg); 612 break; 613 case F_UNLCKSYS: 614 /* 615 * Temporary api for testing remote lock 616 * infrastructure. 617 */ 618 if (flg != F_REMOTE) { 619 error = EINVAL; 620 break; 621 } 622 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 623 F_UNLCKSYS, flp, flg); 624 break; 625 default: 626 error = EINVAL; 627 break; 628 } 629 VFS_UNLOCK_GIANT(vfslocked); 630 vfslocked = 0; 631 /* Check for race with close */ 632 FILEDESC_SLOCK(fdp); 633 if ((unsigned) fd >= fdp->fd_nfiles || 634 fp != fdp->fd_ofiles[fd]) { 635 FILEDESC_SUNLOCK(fdp); 636 flp->l_whence = SEEK_SET; 637 flp->l_start = 0; 638 flp->l_len = 0; 639 flp->l_type = F_UNLCK; 640 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 641 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 642 F_UNLCK, flp, F_POSIX); 643 VFS_UNLOCK_GIANT(vfslocked); 644 vfslocked = 0; 645 } else 646 FILEDESC_SUNLOCK(fdp); 647 fdrop(fp, td); 648 break; 649 650 case F_GETLK: 651 FILEDESC_SLOCK(fdp); 652 if ((fp = fdtofp(fd, fdp)) == NULL) { 653 FILEDESC_SUNLOCK(fdp); 654 error = EBADF; 655 break; 656 } 657 if (fp->f_type != DTYPE_VNODE) { 658 FILEDESC_SUNLOCK(fdp); 659 error = EBADF; 660 break; 661 } 662 flp = (struct flock *)arg; 663 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 664 flp->l_type != F_UNLCK) { 665 FILEDESC_SUNLOCK(fdp); 666 error = EINVAL; 667 break; 668 } 669 if (flp->l_whence == SEEK_CUR) { 670 if ((flp->l_start > 0 && 671 fp->f_offset > OFF_MAX - flp->l_start) || 672 (flp->l_start < 0 && 673 fp->f_offset < OFF_MIN - flp->l_start)) { 674 FILEDESC_SUNLOCK(fdp); 675 error = EOVERFLOW; 676 break; 677 } 678 flp->l_start += fp->f_offset; 679 } 680 /* 681 * VOP_ADVLOCK() may block. 682 */ 683 fhold(fp); 684 FILEDESC_SUNLOCK(fdp); 685 vp = fp->f_vnode; 686 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 687 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 688 F_POSIX); 689 VFS_UNLOCK_GIANT(vfslocked); 690 vfslocked = 0; 691 fdrop(fp, td); 692 break; 693 694 case F_RDAHEAD: 695 arg = arg ? 128 * 1024: 0; 696 /* FALLTHROUGH */ 697 case F_READAHEAD: 698 FILEDESC_SLOCK(fdp); 699 if ((fp = fdtofp(fd, fdp)) == NULL) { 700 FILEDESC_SUNLOCK(fdp); 701 error = EBADF; 702 break; 703 } 704 if (fp->f_type != DTYPE_VNODE) { 705 FILEDESC_SUNLOCK(fdp); 706 error = EBADF; 707 break; 708 } 709 fhold(fp); 710 FILEDESC_SUNLOCK(fdp); 711 if (arg != 0) { 712 vp = fp->f_vnode; 713 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 714 error = vn_lock(vp, LK_SHARED); 715 if (error != 0) 716 goto readahead_vnlock_fail; 717 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 718 VOP_UNLOCK(vp, 0); 719 fp->f_seqcount = (arg + bsize - 1) / bsize; 720 do { 721 new = old = fp->f_flag; 722 new |= FRDAHEAD; 723 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new)); 724 readahead_vnlock_fail: 725 VFS_UNLOCK_GIANT(vfslocked); 726 vfslocked = 0; 727 } else { 728 do { 729 new = old = fp->f_flag; 730 new &= ~FRDAHEAD; 731 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new)); 732 } 733 fdrop(fp, td); 734 break; 735 736 default: 737 error = EINVAL; 738 break; 739 } 740 VFS_UNLOCK_GIANT(vfslocked); 741 return (error); 742 } 743 744 /* 745 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 746 */ 747 static int 748 do_dup(struct thread *td, int flags, int old, int new, 749 register_t *retval) 750 { 751 struct filedesc *fdp; 752 struct proc *p; 753 struct file *fp; 754 struct file *delfp; 755 int error, holdleaders, maxfd; 756 757 p = td->td_proc; 758 fdp = p->p_fd; 759 760 /* 761 * Verify we have a valid descriptor to dup from and possibly to 762 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 763 * return EINVAL when the new descriptor is out of bounds. 764 */ 765 if (old < 0) 766 return (EBADF); 767 if (new < 0) 768 return (flags & DUP_FCNTL ? EINVAL : EBADF); 769 PROC_LOCK(p); 770 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 771 PROC_UNLOCK(p); 772 if (new >= maxfd) 773 return (flags & DUP_FCNTL ? EINVAL : EMFILE); 774 775 FILEDESC_XLOCK(fdp); 776 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 777 FILEDESC_XUNLOCK(fdp); 778 return (EBADF); 779 } 780 if (flags & DUP_FIXED && old == new) { 781 *retval = new; 782 FILEDESC_XUNLOCK(fdp); 783 return (0); 784 } 785 fp = fdp->fd_ofiles[old]; 786 fhold(fp); 787 788 /* 789 * If the caller specified a file descriptor, make sure the file 790 * table is large enough to hold it, and grab it. Otherwise, just 791 * allocate a new descriptor the usual way. Since the filedesc 792 * lock may be temporarily dropped in the process, we have to look 793 * out for a race. 794 */ 795 if (flags & DUP_FIXED) { 796 if (new >= fdp->fd_nfiles) 797 fdgrowtable(fdp, new + 1); 798 if (fdp->fd_ofiles[new] == NULL) 799 fdused(fdp, new); 800 } else { 801 if ((error = fdalloc(td, new, &new)) != 0) { 802 FILEDESC_XUNLOCK(fdp); 803 fdrop(fp, td); 804 return (error); 805 } 806 } 807 808 /* 809 * If the old file changed out from under us then treat it as a 810 * bad file descriptor. Userland should do its own locking to 811 * avoid this case. 812 */ 813 if (fdp->fd_ofiles[old] != fp) { 814 /* we've allocated a descriptor which we won't use */ 815 if (fdp->fd_ofiles[new] == NULL) 816 fdunused(fdp, new); 817 FILEDESC_XUNLOCK(fdp); 818 fdrop(fp, td); 819 return (EBADF); 820 } 821 KASSERT(old != new, 822 ("new fd is same as old")); 823 824 /* 825 * Save info on the descriptor being overwritten. We cannot close 826 * it without introducing an ownership race for the slot, since we 827 * need to drop the filedesc lock to call closef(). 828 * 829 * XXX this duplicates parts of close(). 830 */ 831 delfp = fdp->fd_ofiles[new]; 832 holdleaders = 0; 833 if (delfp != NULL) { 834 if (td->td_proc->p_fdtol != NULL) { 835 /* 836 * Ask fdfree() to sleep to ensure that all relevant 837 * process leaders can be traversed in closef(). 838 */ 839 fdp->fd_holdleaderscount++; 840 holdleaders = 1; 841 } 842 } 843 844 /* 845 * Duplicate the source descriptor 846 */ 847 fdp->fd_ofiles[new] = fp; 848 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 849 if (new > fdp->fd_lastfile) 850 fdp->fd_lastfile = new; 851 *retval = new; 852 853 /* 854 * If we dup'd over a valid file, we now own the reference to it 855 * and must dispose of it using closef() semantics (as if a 856 * close() were performed on it). 857 * 858 * XXX this duplicates parts of close(). 859 */ 860 if (delfp != NULL) { 861 knote_fdclose(td, new); 862 if (delfp->f_type == DTYPE_MQUEUE) 863 mq_fdclose(td, new, delfp); 864 FILEDESC_XUNLOCK(fdp); 865 (void) closef(delfp, td); 866 if (holdleaders) { 867 FILEDESC_XLOCK(fdp); 868 fdp->fd_holdleaderscount--; 869 if (fdp->fd_holdleaderscount == 0 && 870 fdp->fd_holdleaderswakeup != 0) { 871 fdp->fd_holdleaderswakeup = 0; 872 wakeup(&fdp->fd_holdleaderscount); 873 } 874 FILEDESC_XUNLOCK(fdp); 875 } 876 } else { 877 FILEDESC_XUNLOCK(fdp); 878 } 879 return (0); 880 } 881 882 /* 883 * If sigio is on the list associated with a process or process group, 884 * disable signalling from the device, remove sigio from the list and 885 * free sigio. 886 */ 887 void 888 funsetown(struct sigio **sigiop) 889 { 890 struct sigio *sigio; 891 892 SIGIO_LOCK(); 893 sigio = *sigiop; 894 if (sigio == NULL) { 895 SIGIO_UNLOCK(); 896 return; 897 } 898 *(sigio->sio_myref) = NULL; 899 if ((sigio)->sio_pgid < 0) { 900 struct pgrp *pg = (sigio)->sio_pgrp; 901 PGRP_LOCK(pg); 902 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 903 sigio, sio_pgsigio); 904 PGRP_UNLOCK(pg); 905 } else { 906 struct proc *p = (sigio)->sio_proc; 907 PROC_LOCK(p); 908 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 909 sigio, sio_pgsigio); 910 PROC_UNLOCK(p); 911 } 912 SIGIO_UNLOCK(); 913 crfree(sigio->sio_ucred); 914 free(sigio, M_SIGIO); 915 } 916 917 /* 918 * Free a list of sigio structures. 919 * We only need to lock the SIGIO_LOCK because we have made ourselves 920 * inaccessible to callers of fsetown and therefore do not need to lock 921 * the proc or pgrp struct for the list manipulation. 922 */ 923 void 924 funsetownlst(struct sigiolst *sigiolst) 925 { 926 struct proc *p; 927 struct pgrp *pg; 928 struct sigio *sigio; 929 930 sigio = SLIST_FIRST(sigiolst); 931 if (sigio == NULL) 932 return; 933 p = NULL; 934 pg = NULL; 935 936 /* 937 * Every entry of the list should belong 938 * to a single proc or pgrp. 939 */ 940 if (sigio->sio_pgid < 0) { 941 pg = sigio->sio_pgrp; 942 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 943 } else /* if (sigio->sio_pgid > 0) */ { 944 p = sigio->sio_proc; 945 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 946 } 947 948 SIGIO_LOCK(); 949 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 950 *(sigio->sio_myref) = NULL; 951 if (pg != NULL) { 952 KASSERT(sigio->sio_pgid < 0, 953 ("Proc sigio in pgrp sigio list")); 954 KASSERT(sigio->sio_pgrp == pg, 955 ("Bogus pgrp in sigio list")); 956 PGRP_LOCK(pg); 957 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 958 sio_pgsigio); 959 PGRP_UNLOCK(pg); 960 } else /* if (p != NULL) */ { 961 KASSERT(sigio->sio_pgid > 0, 962 ("Pgrp sigio in proc sigio list")); 963 KASSERT(sigio->sio_proc == p, 964 ("Bogus proc in sigio list")); 965 PROC_LOCK(p); 966 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 967 sio_pgsigio); 968 PROC_UNLOCK(p); 969 } 970 SIGIO_UNLOCK(); 971 crfree(sigio->sio_ucred); 972 free(sigio, M_SIGIO); 973 SIGIO_LOCK(); 974 } 975 SIGIO_UNLOCK(); 976 } 977 978 /* 979 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 980 * 981 * After permission checking, add a sigio structure to the sigio list for 982 * the process or process group. 983 */ 984 int 985 fsetown(pid_t pgid, struct sigio **sigiop) 986 { 987 struct proc *proc; 988 struct pgrp *pgrp; 989 struct sigio *sigio; 990 int ret; 991 992 if (pgid == 0) { 993 funsetown(sigiop); 994 return (0); 995 } 996 997 ret = 0; 998 999 /* Allocate and fill in the new sigio out of locks. */ 1000 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1001 sigio->sio_pgid = pgid; 1002 sigio->sio_ucred = crhold(curthread->td_ucred); 1003 sigio->sio_myref = sigiop; 1004 1005 sx_slock(&proctree_lock); 1006 if (pgid > 0) { 1007 proc = pfind(pgid); 1008 if (proc == NULL) { 1009 ret = ESRCH; 1010 goto fail; 1011 } 1012 1013 /* 1014 * Policy - Don't allow a process to FSETOWN a process 1015 * in another session. 1016 * 1017 * Remove this test to allow maximum flexibility or 1018 * restrict FSETOWN to the current process or process 1019 * group for maximum safety. 1020 */ 1021 PROC_UNLOCK(proc); 1022 if (proc->p_session != curthread->td_proc->p_session) { 1023 ret = EPERM; 1024 goto fail; 1025 } 1026 1027 pgrp = NULL; 1028 } else /* if (pgid < 0) */ { 1029 pgrp = pgfind(-pgid); 1030 if (pgrp == NULL) { 1031 ret = ESRCH; 1032 goto fail; 1033 } 1034 PGRP_UNLOCK(pgrp); 1035 1036 /* 1037 * Policy - Don't allow a process to FSETOWN a process 1038 * in another session. 1039 * 1040 * Remove this test to allow maximum flexibility or 1041 * restrict FSETOWN to the current process or process 1042 * group for maximum safety. 1043 */ 1044 if (pgrp->pg_session != curthread->td_proc->p_session) { 1045 ret = EPERM; 1046 goto fail; 1047 } 1048 1049 proc = NULL; 1050 } 1051 funsetown(sigiop); 1052 if (pgid > 0) { 1053 PROC_LOCK(proc); 1054 /* 1055 * Since funsetownlst() is called without the proctree 1056 * locked, we need to check for P_WEXIT. 1057 * XXX: is ESRCH correct? 1058 */ 1059 if ((proc->p_flag & P_WEXIT) != 0) { 1060 PROC_UNLOCK(proc); 1061 ret = ESRCH; 1062 goto fail; 1063 } 1064 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1065 sigio->sio_proc = proc; 1066 PROC_UNLOCK(proc); 1067 } else { 1068 PGRP_LOCK(pgrp); 1069 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1070 sigio->sio_pgrp = pgrp; 1071 PGRP_UNLOCK(pgrp); 1072 } 1073 sx_sunlock(&proctree_lock); 1074 SIGIO_LOCK(); 1075 *sigiop = sigio; 1076 SIGIO_UNLOCK(); 1077 return (0); 1078 1079 fail: 1080 sx_sunlock(&proctree_lock); 1081 crfree(sigio->sio_ucred); 1082 free(sigio, M_SIGIO); 1083 return (ret); 1084 } 1085 1086 /* 1087 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1088 */ 1089 pid_t 1090 fgetown(sigiop) 1091 struct sigio **sigiop; 1092 { 1093 pid_t pgid; 1094 1095 SIGIO_LOCK(); 1096 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1097 SIGIO_UNLOCK(); 1098 return (pgid); 1099 } 1100 1101 /* 1102 * Close a file descriptor. 1103 */ 1104 #ifndef _SYS_SYSPROTO_H_ 1105 struct close_args { 1106 int fd; 1107 }; 1108 #endif 1109 /* ARGSUSED */ 1110 int 1111 close(td, uap) 1112 struct thread *td; 1113 struct close_args *uap; 1114 { 1115 1116 return (kern_close(td, uap->fd)); 1117 } 1118 1119 int 1120 kern_close(td, fd) 1121 struct thread *td; 1122 int fd; 1123 { 1124 struct filedesc *fdp; 1125 struct file *fp; 1126 int error; 1127 int holdleaders; 1128 1129 error = 0; 1130 holdleaders = 0; 1131 fdp = td->td_proc->p_fd; 1132 1133 AUDIT_SYSCLOSE(td, fd); 1134 1135 FILEDESC_XLOCK(fdp); 1136 if ((unsigned)fd >= fdp->fd_nfiles || 1137 (fp = fdp->fd_ofiles[fd]) == NULL) { 1138 FILEDESC_XUNLOCK(fdp); 1139 return (EBADF); 1140 } 1141 fdp->fd_ofiles[fd] = NULL; 1142 fdp->fd_ofileflags[fd] = 0; 1143 fdunused(fdp, fd); 1144 if (td->td_proc->p_fdtol != NULL) { 1145 /* 1146 * Ask fdfree() to sleep to ensure that all relevant 1147 * process leaders can be traversed in closef(). 1148 */ 1149 fdp->fd_holdleaderscount++; 1150 holdleaders = 1; 1151 } 1152 1153 /* 1154 * We now hold the fp reference that used to be owned by the 1155 * descriptor array. We have to unlock the FILEDESC *AFTER* 1156 * knote_fdclose to prevent a race of the fd getting opened, a knote 1157 * added, and deleteing a knote for the new fd. 1158 */ 1159 knote_fdclose(td, fd); 1160 if (fp->f_type == DTYPE_MQUEUE) 1161 mq_fdclose(td, fd, fp); 1162 FILEDESC_XUNLOCK(fdp); 1163 1164 error = closef(fp, td); 1165 if (holdleaders) { 1166 FILEDESC_XLOCK(fdp); 1167 fdp->fd_holdleaderscount--; 1168 if (fdp->fd_holdleaderscount == 0 && 1169 fdp->fd_holdleaderswakeup != 0) { 1170 fdp->fd_holdleaderswakeup = 0; 1171 wakeup(&fdp->fd_holdleaderscount); 1172 } 1173 FILEDESC_XUNLOCK(fdp); 1174 } 1175 return (error); 1176 } 1177 1178 /* 1179 * Close open file descriptors. 1180 */ 1181 #ifndef _SYS_SYSPROTO_H_ 1182 struct closefrom_args { 1183 int lowfd; 1184 }; 1185 #endif 1186 /* ARGSUSED */ 1187 int 1188 closefrom(struct thread *td, struct closefrom_args *uap) 1189 { 1190 struct filedesc *fdp; 1191 int fd; 1192 1193 fdp = td->td_proc->p_fd; 1194 AUDIT_ARG_FD(uap->lowfd); 1195 1196 /* 1197 * Treat negative starting file descriptor values identical to 1198 * closefrom(0) which closes all files. 1199 */ 1200 if (uap->lowfd < 0) 1201 uap->lowfd = 0; 1202 FILEDESC_SLOCK(fdp); 1203 for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) { 1204 if (fdp->fd_ofiles[fd] != NULL) { 1205 FILEDESC_SUNLOCK(fdp); 1206 (void)kern_close(td, fd); 1207 FILEDESC_SLOCK(fdp); 1208 } 1209 } 1210 FILEDESC_SUNLOCK(fdp); 1211 return (0); 1212 } 1213 1214 #if defined(COMPAT_43) 1215 /* 1216 * Return status information about a file descriptor. 1217 */ 1218 #ifndef _SYS_SYSPROTO_H_ 1219 struct ofstat_args { 1220 int fd; 1221 struct ostat *sb; 1222 }; 1223 #endif 1224 /* ARGSUSED */ 1225 int 1226 ofstat(struct thread *td, struct ofstat_args *uap) 1227 { 1228 struct ostat oub; 1229 struct stat ub; 1230 int error; 1231 1232 error = kern_fstat(td, uap->fd, &ub); 1233 if (error == 0) { 1234 cvtstat(&ub, &oub); 1235 error = copyout(&oub, uap->sb, sizeof(oub)); 1236 } 1237 return (error); 1238 } 1239 #endif /* COMPAT_43 */ 1240 1241 /* 1242 * Return status information about a file descriptor. 1243 */ 1244 #ifndef _SYS_SYSPROTO_H_ 1245 struct fstat_args { 1246 int fd; 1247 struct stat *sb; 1248 }; 1249 #endif 1250 /* ARGSUSED */ 1251 int 1252 fstat(struct thread *td, struct fstat_args *uap) 1253 { 1254 struct stat ub; 1255 int error; 1256 1257 error = kern_fstat(td, uap->fd, &ub); 1258 if (error == 0) 1259 error = copyout(&ub, uap->sb, sizeof(ub)); 1260 return (error); 1261 } 1262 1263 int 1264 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1265 { 1266 struct file *fp; 1267 int error; 1268 1269 AUDIT_ARG_FD(fd); 1270 1271 if ((error = fget(td, fd, &fp)) != 0) 1272 return (error); 1273 1274 AUDIT_ARG_FILE(td->td_proc, fp); 1275 1276 error = fo_stat(fp, sbp, td->td_ucred, td); 1277 fdrop(fp, td); 1278 #ifdef KTRACE 1279 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1280 ktrstat(sbp); 1281 #endif 1282 return (error); 1283 } 1284 1285 /* 1286 * Return status information about a file descriptor. 1287 */ 1288 #ifndef _SYS_SYSPROTO_H_ 1289 struct nfstat_args { 1290 int fd; 1291 struct nstat *sb; 1292 }; 1293 #endif 1294 /* ARGSUSED */ 1295 int 1296 nfstat(struct thread *td, struct nfstat_args *uap) 1297 { 1298 struct nstat nub; 1299 struct stat ub; 1300 int error; 1301 1302 error = kern_fstat(td, uap->fd, &ub); 1303 if (error == 0) { 1304 cvtnstat(&ub, &nub); 1305 error = copyout(&nub, uap->sb, sizeof(nub)); 1306 } 1307 return (error); 1308 } 1309 1310 /* 1311 * Return pathconf information about a file descriptor. 1312 */ 1313 #ifndef _SYS_SYSPROTO_H_ 1314 struct fpathconf_args { 1315 int fd; 1316 int name; 1317 }; 1318 #endif 1319 /* ARGSUSED */ 1320 int 1321 fpathconf(struct thread *td, struct fpathconf_args *uap) 1322 { 1323 struct file *fp; 1324 struct vnode *vp; 1325 int error; 1326 1327 if ((error = fget(td, uap->fd, &fp)) != 0) 1328 return (error); 1329 1330 /* If asynchronous I/O is available, it works for all descriptors. */ 1331 if (uap->name == _PC_ASYNC_IO) { 1332 td->td_retval[0] = async_io_version; 1333 goto out; 1334 } 1335 vp = fp->f_vnode; 1336 if (vp != NULL) { 1337 int vfslocked; 1338 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1339 vn_lock(vp, LK_SHARED | LK_RETRY); 1340 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1341 VOP_UNLOCK(vp, 0); 1342 VFS_UNLOCK_GIANT(vfslocked); 1343 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1344 if (uap->name != _PC_PIPE_BUF) { 1345 error = EINVAL; 1346 } else { 1347 td->td_retval[0] = PIPE_BUF; 1348 error = 0; 1349 } 1350 } else { 1351 error = EOPNOTSUPP; 1352 } 1353 out: 1354 fdrop(fp, td); 1355 return (error); 1356 } 1357 1358 /* 1359 * Grow the file table to accomodate (at least) nfd descriptors. This may 1360 * block and drop the filedesc lock, but it will reacquire it before 1361 * returning. 1362 */ 1363 static void 1364 fdgrowtable(struct filedesc *fdp, int nfd) 1365 { 1366 struct filedesc0 *fdp0; 1367 struct freetable *fo; 1368 struct file **ntable; 1369 struct file **otable; 1370 char *nfileflags; 1371 int nnfiles, onfiles; 1372 NDSLOTTYPE *nmap; 1373 1374 FILEDESC_XLOCK_ASSERT(fdp); 1375 1376 KASSERT(fdp->fd_nfiles > 0, 1377 ("zero-length file table")); 1378 1379 /* compute the size of the new table */ 1380 onfiles = fdp->fd_nfiles; 1381 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1382 if (nnfiles <= onfiles) 1383 /* the table is already large enough */ 1384 return; 1385 1386 /* allocate a new table and (if required) new bitmaps */ 1387 FILEDESC_XUNLOCK(fdp); 1388 ntable = malloc((nnfiles * OFILESIZE) + sizeof(struct freetable), 1389 M_FILEDESC, M_ZERO | M_WAITOK); 1390 nfileflags = (char *)&ntable[nnfiles]; 1391 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) 1392 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, 1393 M_FILEDESC, M_ZERO | M_WAITOK); 1394 else 1395 nmap = NULL; 1396 FILEDESC_XLOCK(fdp); 1397 1398 /* 1399 * We now have new tables ready to go. Since we dropped the 1400 * filedesc lock to call malloc(), watch out for a race. 1401 */ 1402 onfiles = fdp->fd_nfiles; 1403 if (onfiles >= nnfiles) { 1404 /* we lost the race, but that's OK */ 1405 free(ntable, M_FILEDESC); 1406 if (nmap != NULL) 1407 free(nmap, M_FILEDESC); 1408 return; 1409 } 1410 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable)); 1411 bcopy(fdp->fd_ofileflags, nfileflags, onfiles); 1412 otable = fdp->fd_ofiles; 1413 fdp->fd_ofileflags = nfileflags; 1414 fdp->fd_ofiles = ntable; 1415 /* 1416 * We must preserve ofiles until the process exits because we can't 1417 * be certain that no threads have references to the old table via 1418 * _fget(). 1419 */ 1420 if (onfiles > NDFILE) { 1421 fo = (struct freetable *)&otable[onfiles]; 1422 fdp0 = (struct filedesc0 *)fdp; 1423 fo->ft_table = otable; 1424 SLIST_INSERT_HEAD(&fdp0->fd_free, fo, ft_next); 1425 } 1426 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1427 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap)); 1428 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1429 free(fdp->fd_map, M_FILEDESC); 1430 fdp->fd_map = nmap; 1431 } 1432 fdp->fd_nfiles = nnfiles; 1433 } 1434 1435 /* 1436 * Allocate a file descriptor for the process. 1437 */ 1438 int 1439 fdalloc(struct thread *td, int minfd, int *result) 1440 { 1441 struct proc *p = td->td_proc; 1442 struct filedesc *fdp = p->p_fd; 1443 int fd = -1, maxfd; 1444 1445 FILEDESC_XLOCK_ASSERT(fdp); 1446 1447 if (fdp->fd_freefile > minfd) 1448 minfd = fdp->fd_freefile; 1449 1450 PROC_LOCK(p); 1451 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1452 PROC_UNLOCK(p); 1453 1454 /* 1455 * Search the bitmap for a free descriptor. If none is found, try 1456 * to grow the file table. Keep at it until we either get a file 1457 * descriptor or run into process or system limits; fdgrowtable() 1458 * may drop the filedesc lock, so we're in a race. 1459 */ 1460 for (;;) { 1461 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1462 if (fd >= maxfd) 1463 return (EMFILE); 1464 if (fd < fdp->fd_nfiles) 1465 break; 1466 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd)); 1467 } 1468 1469 /* 1470 * Perform some sanity checks, then mark the file descriptor as 1471 * used and return it to the caller. 1472 */ 1473 KASSERT(!fdisused(fdp, fd), 1474 ("fd_first_free() returned non-free descriptor")); 1475 KASSERT(fdp->fd_ofiles[fd] == NULL, 1476 ("free descriptor isn't")); 1477 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */ 1478 fdused(fdp, fd); 1479 *result = fd; 1480 return (0); 1481 } 1482 1483 /* 1484 * Check to see whether n user file descriptors are available to the process 1485 * p. 1486 */ 1487 int 1488 fdavail(struct thread *td, int n) 1489 { 1490 struct proc *p = td->td_proc; 1491 struct filedesc *fdp = td->td_proc->p_fd; 1492 struct file **fpp; 1493 int i, lim, last; 1494 1495 FILEDESC_LOCK_ASSERT(fdp); 1496 1497 PROC_LOCK(p); 1498 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1499 PROC_UNLOCK(p); 1500 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1501 return (1); 1502 last = min(fdp->fd_nfiles, lim); 1503 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 1504 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 1505 if (*fpp == NULL && --n <= 0) 1506 return (1); 1507 } 1508 return (0); 1509 } 1510 1511 /* 1512 * Create a new open file structure and allocate a file decriptor for the 1513 * process that refers to it. We add one reference to the file for the 1514 * descriptor table and one reference for resultfp. This is to prevent us 1515 * being preempted and the entry in the descriptor table closed after we 1516 * release the FILEDESC lock. 1517 */ 1518 int 1519 fallocf(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1520 { 1521 struct proc *p = td->td_proc; 1522 struct file *fp; 1523 int error, i; 1524 int maxuserfiles = maxfiles - (maxfiles / 20); 1525 static struct timeval lastfail; 1526 static int curfail; 1527 1528 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1529 if ((openfiles >= maxuserfiles && 1530 priv_check(td, PRIV_MAXFILES) != 0) || 1531 openfiles >= maxfiles) { 1532 if (ppsratecheck(&lastfail, &curfail, 1)) { 1533 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n", 1534 td->td_ucred->cr_ruid); 1535 } 1536 uma_zfree(file_zone, fp); 1537 return (ENFILE); 1538 } 1539 atomic_add_int(&openfiles, 1); 1540 1541 /* 1542 * If the process has file descriptor zero open, add the new file 1543 * descriptor to the list of open files at that point, otherwise 1544 * put it at the front of the list of open files. 1545 */ 1546 refcount_init(&fp->f_count, 1); 1547 if (resultfp) 1548 fhold(fp); 1549 fp->f_cred = crhold(td->td_ucred); 1550 fp->f_ops = &badfileops; 1551 fp->f_data = NULL; 1552 fp->f_vnode = NULL; 1553 FILEDESC_XLOCK(p->p_fd); 1554 if ((error = fdalloc(td, 0, &i))) { 1555 FILEDESC_XUNLOCK(p->p_fd); 1556 fdrop(fp, td); 1557 if (resultfp) 1558 fdrop(fp, td); 1559 return (error); 1560 } 1561 p->p_fd->fd_ofiles[i] = fp; 1562 if ((flags & O_CLOEXEC) != 0) 1563 p->p_fd->fd_ofileflags[i] |= UF_EXCLOSE; 1564 FILEDESC_XUNLOCK(p->p_fd); 1565 if (resultfp) 1566 *resultfp = fp; 1567 if (resultfd) 1568 *resultfd = i; 1569 return (0); 1570 } 1571 1572 int 1573 falloc(struct thread *td, struct file **resultfp, int *resultfd) 1574 { 1575 1576 return (fallocf(td, resultfp, resultfd, 0)); 1577 } 1578 1579 /* 1580 * Build a new filedesc structure from another. 1581 * Copy the current, root, and jail root vnode references. 1582 */ 1583 struct filedesc * 1584 fdinit(struct filedesc *fdp) 1585 { 1586 struct filedesc0 *newfdp; 1587 1588 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO); 1589 FILEDESC_LOCK_INIT(&newfdp->fd_fd); 1590 if (fdp != NULL) { 1591 FILEDESC_XLOCK(fdp); 1592 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1593 if (newfdp->fd_fd.fd_cdir) 1594 VREF(newfdp->fd_fd.fd_cdir); 1595 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1596 if (newfdp->fd_fd.fd_rdir) 1597 VREF(newfdp->fd_fd.fd_rdir); 1598 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1599 if (newfdp->fd_fd.fd_jdir) 1600 VREF(newfdp->fd_fd.fd_jdir); 1601 FILEDESC_XUNLOCK(fdp); 1602 } 1603 1604 /* Create the file descriptor table. */ 1605 newfdp->fd_fd.fd_refcnt = 1; 1606 newfdp->fd_fd.fd_holdcnt = 1; 1607 newfdp->fd_fd.fd_cmask = CMASK; 1608 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1609 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1610 newfdp->fd_fd.fd_nfiles = NDFILE; 1611 newfdp->fd_fd.fd_map = newfdp->fd_dmap; 1612 newfdp->fd_fd.fd_lastfile = -1; 1613 return (&newfdp->fd_fd); 1614 } 1615 1616 static struct filedesc * 1617 fdhold(struct proc *p) 1618 { 1619 struct filedesc *fdp; 1620 1621 mtx_lock(&fdesc_mtx); 1622 fdp = p->p_fd; 1623 if (fdp != NULL) 1624 fdp->fd_holdcnt++; 1625 mtx_unlock(&fdesc_mtx); 1626 return (fdp); 1627 } 1628 1629 static void 1630 fddrop(struct filedesc *fdp) 1631 { 1632 struct filedesc0 *fdp0; 1633 struct freetable *ft; 1634 int i; 1635 1636 mtx_lock(&fdesc_mtx); 1637 i = --fdp->fd_holdcnt; 1638 mtx_unlock(&fdesc_mtx); 1639 if (i > 0) 1640 return; 1641 1642 FILEDESC_LOCK_DESTROY(fdp); 1643 fdp0 = (struct filedesc0 *)fdp; 1644 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) { 1645 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next); 1646 free(ft->ft_table, M_FILEDESC); 1647 } 1648 free(fdp, M_FILEDESC); 1649 } 1650 1651 /* 1652 * Share a filedesc structure. 1653 */ 1654 struct filedesc * 1655 fdshare(struct filedesc *fdp) 1656 { 1657 1658 FILEDESC_XLOCK(fdp); 1659 fdp->fd_refcnt++; 1660 FILEDESC_XUNLOCK(fdp); 1661 return (fdp); 1662 } 1663 1664 /* 1665 * Unshare a filedesc structure, if necessary by making a copy 1666 */ 1667 void 1668 fdunshare(struct proc *p, struct thread *td) 1669 { 1670 1671 FILEDESC_XLOCK(p->p_fd); 1672 if (p->p_fd->fd_refcnt > 1) { 1673 struct filedesc *tmp; 1674 1675 FILEDESC_XUNLOCK(p->p_fd); 1676 tmp = fdcopy(p->p_fd); 1677 fdfree(td); 1678 p->p_fd = tmp; 1679 } else 1680 FILEDESC_XUNLOCK(p->p_fd); 1681 } 1682 1683 /* 1684 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1685 * this is to ease callers, not catch errors. 1686 */ 1687 struct filedesc * 1688 fdcopy(struct filedesc *fdp) 1689 { 1690 struct filedesc *newfdp; 1691 int i; 1692 1693 /* Certain daemons might not have file descriptors. */ 1694 if (fdp == NULL) 1695 return (NULL); 1696 1697 newfdp = fdinit(fdp); 1698 FILEDESC_SLOCK(fdp); 1699 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1700 FILEDESC_SUNLOCK(fdp); 1701 FILEDESC_XLOCK(newfdp); 1702 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1703 FILEDESC_XUNLOCK(newfdp); 1704 FILEDESC_SLOCK(fdp); 1705 } 1706 /* copy everything except kqueue descriptors */ 1707 newfdp->fd_freefile = -1; 1708 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1709 if (fdisused(fdp, i) && 1710 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE && 1711 fdp->fd_ofiles[i]->f_ops != &badfileops) { 1712 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i]; 1713 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i]; 1714 fhold(newfdp->fd_ofiles[i]); 1715 newfdp->fd_lastfile = i; 1716 } else { 1717 if (newfdp->fd_freefile == -1) 1718 newfdp->fd_freefile = i; 1719 } 1720 } 1721 newfdp->fd_cmask = fdp->fd_cmask; 1722 FILEDESC_SUNLOCK(fdp); 1723 FILEDESC_XLOCK(newfdp); 1724 for (i = 0; i <= newfdp->fd_lastfile; ++i) 1725 if (newfdp->fd_ofiles[i] != NULL) 1726 fdused(newfdp, i); 1727 if (newfdp->fd_freefile == -1) 1728 newfdp->fd_freefile = i; 1729 FILEDESC_XUNLOCK(newfdp); 1730 return (newfdp); 1731 } 1732 1733 /* 1734 * Release a filedesc structure. 1735 */ 1736 void 1737 fdfree(struct thread *td) 1738 { 1739 struct filedesc *fdp; 1740 struct file **fpp; 1741 int i, locked; 1742 struct filedesc_to_leader *fdtol; 1743 struct file *fp; 1744 struct vnode *cdir, *jdir, *rdir, *vp; 1745 struct flock lf; 1746 1747 /* Certain daemons might not have file descriptors. */ 1748 fdp = td->td_proc->p_fd; 1749 if (fdp == NULL) 1750 return; 1751 1752 /* Check for special need to clear POSIX style locks */ 1753 fdtol = td->td_proc->p_fdtol; 1754 if (fdtol != NULL) { 1755 FILEDESC_XLOCK(fdp); 1756 KASSERT(fdtol->fdl_refcount > 0, 1757 ("filedesc_to_refcount botch: fdl_refcount=%d", 1758 fdtol->fdl_refcount)); 1759 if (fdtol->fdl_refcount == 1 && 1760 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1761 for (i = 0, fpp = fdp->fd_ofiles; 1762 i <= fdp->fd_lastfile; 1763 i++, fpp++) { 1764 if (*fpp == NULL || 1765 (*fpp)->f_type != DTYPE_VNODE) 1766 continue; 1767 fp = *fpp; 1768 fhold(fp); 1769 FILEDESC_XUNLOCK(fdp); 1770 lf.l_whence = SEEK_SET; 1771 lf.l_start = 0; 1772 lf.l_len = 0; 1773 lf.l_type = F_UNLCK; 1774 vp = fp->f_vnode; 1775 locked = VFS_LOCK_GIANT(vp->v_mount); 1776 (void) VOP_ADVLOCK(vp, 1777 (caddr_t)td->td_proc-> 1778 p_leader, 1779 F_UNLCK, 1780 &lf, 1781 F_POSIX); 1782 VFS_UNLOCK_GIANT(locked); 1783 FILEDESC_XLOCK(fdp); 1784 fdrop(fp, td); 1785 fpp = fdp->fd_ofiles + i; 1786 } 1787 } 1788 retry: 1789 if (fdtol->fdl_refcount == 1) { 1790 if (fdp->fd_holdleaderscount > 0 && 1791 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1792 /* 1793 * close() or do_dup() has cleared a reference 1794 * in a shared file descriptor table. 1795 */ 1796 fdp->fd_holdleaderswakeup = 1; 1797 sx_sleep(&fdp->fd_holdleaderscount, 1798 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1799 goto retry; 1800 } 1801 if (fdtol->fdl_holdcount > 0) { 1802 /* 1803 * Ensure that fdtol->fdl_leader remains 1804 * valid in closef(). 1805 */ 1806 fdtol->fdl_wakeup = 1; 1807 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 1808 "fdlhold", 0); 1809 goto retry; 1810 } 1811 } 1812 fdtol->fdl_refcount--; 1813 if (fdtol->fdl_refcount == 0 && 1814 fdtol->fdl_holdcount == 0) { 1815 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1816 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1817 } else 1818 fdtol = NULL; 1819 td->td_proc->p_fdtol = NULL; 1820 FILEDESC_XUNLOCK(fdp); 1821 if (fdtol != NULL) 1822 free(fdtol, M_FILEDESC_TO_LEADER); 1823 } 1824 FILEDESC_XLOCK(fdp); 1825 i = --fdp->fd_refcnt; 1826 FILEDESC_XUNLOCK(fdp); 1827 if (i > 0) 1828 return; 1829 1830 fpp = fdp->fd_ofiles; 1831 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1832 if (*fpp) { 1833 FILEDESC_XLOCK(fdp); 1834 fp = *fpp; 1835 *fpp = NULL; 1836 FILEDESC_XUNLOCK(fdp); 1837 (void) closef(fp, td); 1838 } 1839 } 1840 FILEDESC_XLOCK(fdp); 1841 1842 /* XXX This should happen earlier. */ 1843 mtx_lock(&fdesc_mtx); 1844 td->td_proc->p_fd = NULL; 1845 mtx_unlock(&fdesc_mtx); 1846 1847 if (fdp->fd_nfiles > NDFILE) 1848 free(fdp->fd_ofiles, M_FILEDESC); 1849 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 1850 free(fdp->fd_map, M_FILEDESC); 1851 1852 fdp->fd_nfiles = 0; 1853 1854 cdir = fdp->fd_cdir; 1855 fdp->fd_cdir = NULL; 1856 rdir = fdp->fd_rdir; 1857 fdp->fd_rdir = NULL; 1858 jdir = fdp->fd_jdir; 1859 fdp->fd_jdir = NULL; 1860 FILEDESC_XUNLOCK(fdp); 1861 1862 if (cdir) { 1863 locked = VFS_LOCK_GIANT(cdir->v_mount); 1864 vrele(cdir); 1865 VFS_UNLOCK_GIANT(locked); 1866 } 1867 if (rdir) { 1868 locked = VFS_LOCK_GIANT(rdir->v_mount); 1869 vrele(rdir); 1870 VFS_UNLOCK_GIANT(locked); 1871 } 1872 if (jdir) { 1873 locked = VFS_LOCK_GIANT(jdir->v_mount); 1874 vrele(jdir); 1875 VFS_UNLOCK_GIANT(locked); 1876 } 1877 1878 fddrop(fdp); 1879 } 1880 1881 /* 1882 * For setugid programs, we don't want to people to use that setugidness 1883 * to generate error messages which write to a file which otherwise would 1884 * otherwise be off-limits to the process. We check for filesystems where 1885 * the vnode can change out from under us after execve (like [lin]procfs). 1886 * 1887 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1888 * sufficient. We also don't check for setugidness since we know we are. 1889 */ 1890 static int 1891 is_unsafe(struct file *fp) 1892 { 1893 if (fp->f_type == DTYPE_VNODE) { 1894 struct vnode *vp = fp->f_vnode; 1895 1896 if ((vp->v_vflag & VV_PROCDEP) != 0) 1897 return (1); 1898 } 1899 return (0); 1900 } 1901 1902 /* 1903 * Make this setguid thing safe, if at all possible. 1904 */ 1905 void 1906 setugidsafety(struct thread *td) 1907 { 1908 struct filedesc *fdp; 1909 int i; 1910 1911 /* Certain daemons might not have file descriptors. */ 1912 fdp = td->td_proc->p_fd; 1913 if (fdp == NULL) 1914 return; 1915 1916 /* 1917 * Note: fdp->fd_ofiles may be reallocated out from under us while 1918 * we are blocked in a close. Be careful! 1919 */ 1920 FILEDESC_XLOCK(fdp); 1921 for (i = 0; i <= fdp->fd_lastfile; i++) { 1922 if (i > 2) 1923 break; 1924 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1925 struct file *fp; 1926 1927 knote_fdclose(td, i); 1928 /* 1929 * NULL-out descriptor prior to close to avoid 1930 * a race while close blocks. 1931 */ 1932 fp = fdp->fd_ofiles[i]; 1933 fdp->fd_ofiles[i] = NULL; 1934 fdp->fd_ofileflags[i] = 0; 1935 fdunused(fdp, i); 1936 FILEDESC_XUNLOCK(fdp); 1937 (void) closef(fp, td); 1938 FILEDESC_XLOCK(fdp); 1939 } 1940 } 1941 FILEDESC_XUNLOCK(fdp); 1942 } 1943 1944 /* 1945 * If a specific file object occupies a specific file descriptor, close the 1946 * file descriptor entry and drop a reference on the file object. This is a 1947 * convenience function to handle a subsequent error in a function that calls 1948 * falloc() that handles the race that another thread might have closed the 1949 * file descriptor out from under the thread creating the file object. 1950 */ 1951 void 1952 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 1953 { 1954 1955 FILEDESC_XLOCK(fdp); 1956 if (fdp->fd_ofiles[idx] == fp) { 1957 fdp->fd_ofiles[idx] = NULL; 1958 fdunused(fdp, idx); 1959 FILEDESC_XUNLOCK(fdp); 1960 fdrop(fp, td); 1961 } else 1962 FILEDESC_XUNLOCK(fdp); 1963 } 1964 1965 /* 1966 * Close any files on exec? 1967 */ 1968 void 1969 fdcloseexec(struct thread *td) 1970 { 1971 struct filedesc *fdp; 1972 int i; 1973 1974 /* Certain daemons might not have file descriptors. */ 1975 fdp = td->td_proc->p_fd; 1976 if (fdp == NULL) 1977 return; 1978 1979 FILEDESC_XLOCK(fdp); 1980 1981 /* 1982 * We cannot cache fd_ofiles or fd_ofileflags since operations 1983 * may block and rip them out from under us. 1984 */ 1985 for (i = 0; i <= fdp->fd_lastfile; i++) { 1986 if (fdp->fd_ofiles[i] != NULL && 1987 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE || 1988 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) { 1989 struct file *fp; 1990 1991 knote_fdclose(td, i); 1992 /* 1993 * NULL-out descriptor prior to close to avoid 1994 * a race while close blocks. 1995 */ 1996 fp = fdp->fd_ofiles[i]; 1997 fdp->fd_ofiles[i] = NULL; 1998 fdp->fd_ofileflags[i] = 0; 1999 fdunused(fdp, i); 2000 if (fp->f_type == DTYPE_MQUEUE) 2001 mq_fdclose(td, i, fp); 2002 FILEDESC_XUNLOCK(fdp); 2003 (void) closef(fp, td); 2004 FILEDESC_XLOCK(fdp); 2005 } 2006 } 2007 FILEDESC_XUNLOCK(fdp); 2008 } 2009 2010 /* 2011 * It is unsafe for set[ug]id processes to be started with file 2012 * descriptors 0..2 closed, as these descriptors are given implicit 2013 * significance in the Standard C library. fdcheckstd() will create a 2014 * descriptor referencing /dev/null for each of stdin, stdout, and 2015 * stderr that is not already open. 2016 */ 2017 int 2018 fdcheckstd(struct thread *td) 2019 { 2020 struct filedesc *fdp; 2021 register_t retval, save; 2022 int i, error, devnull; 2023 2024 fdp = td->td_proc->p_fd; 2025 if (fdp == NULL) 2026 return (0); 2027 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2028 devnull = -1; 2029 error = 0; 2030 for (i = 0; i < 3; i++) { 2031 if (fdp->fd_ofiles[i] != NULL) 2032 continue; 2033 if (devnull < 0) { 2034 save = td->td_retval[0]; 2035 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 2036 O_RDWR, 0); 2037 devnull = td->td_retval[0]; 2038 td->td_retval[0] = save; 2039 if (error) 2040 break; 2041 KASSERT(devnull == i, ("oof, we didn't get our fd")); 2042 } else { 2043 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 2044 if (error != 0) 2045 break; 2046 } 2047 } 2048 return (error); 2049 } 2050 2051 /* 2052 * Internal form of close. Decrement reference count on file structure. 2053 * Note: td may be NULL when closing a file that was being passed in a 2054 * message. 2055 * 2056 * XXXRW: Giant is not required for the caller, but often will be held; this 2057 * makes it moderately likely the Giant will be recursed in the VFS case. 2058 */ 2059 int 2060 closef(struct file *fp, struct thread *td) 2061 { 2062 struct vnode *vp; 2063 struct flock lf; 2064 struct filedesc_to_leader *fdtol; 2065 struct filedesc *fdp; 2066 2067 /* 2068 * POSIX record locking dictates that any close releases ALL 2069 * locks owned by this process. This is handled by setting 2070 * a flag in the unlock to free ONLY locks obeying POSIX 2071 * semantics, and not to free BSD-style file locks. 2072 * If the descriptor was in a message, POSIX-style locks 2073 * aren't passed with the descriptor, and the thread pointer 2074 * will be NULL. Callers should be careful only to pass a 2075 * NULL thread pointer when there really is no owning 2076 * context that might have locks, or the locks will be 2077 * leaked. 2078 */ 2079 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2080 int vfslocked; 2081 2082 vp = fp->f_vnode; 2083 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2084 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2085 lf.l_whence = SEEK_SET; 2086 lf.l_start = 0; 2087 lf.l_len = 0; 2088 lf.l_type = F_UNLCK; 2089 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2090 F_UNLCK, &lf, F_POSIX); 2091 } 2092 fdtol = td->td_proc->p_fdtol; 2093 if (fdtol != NULL) { 2094 /* 2095 * Handle special case where file descriptor table is 2096 * shared between multiple process leaders. 2097 */ 2098 fdp = td->td_proc->p_fd; 2099 FILEDESC_XLOCK(fdp); 2100 for (fdtol = fdtol->fdl_next; 2101 fdtol != td->td_proc->p_fdtol; 2102 fdtol = fdtol->fdl_next) { 2103 if ((fdtol->fdl_leader->p_flag & 2104 P_ADVLOCK) == 0) 2105 continue; 2106 fdtol->fdl_holdcount++; 2107 FILEDESC_XUNLOCK(fdp); 2108 lf.l_whence = SEEK_SET; 2109 lf.l_start = 0; 2110 lf.l_len = 0; 2111 lf.l_type = F_UNLCK; 2112 vp = fp->f_vnode; 2113 (void) VOP_ADVLOCK(vp, 2114 (caddr_t)fdtol->fdl_leader, 2115 F_UNLCK, &lf, F_POSIX); 2116 FILEDESC_XLOCK(fdp); 2117 fdtol->fdl_holdcount--; 2118 if (fdtol->fdl_holdcount == 0 && 2119 fdtol->fdl_wakeup != 0) { 2120 fdtol->fdl_wakeup = 0; 2121 wakeup(fdtol); 2122 } 2123 } 2124 FILEDESC_XUNLOCK(fdp); 2125 } 2126 VFS_UNLOCK_GIANT(vfslocked); 2127 } 2128 return (fdrop(fp, td)); 2129 } 2130 2131 /* 2132 * Initialize the file pointer with the specified properties. 2133 * 2134 * The ops are set with release semantics to be certain that the flags, type, 2135 * and data are visible when ops is. This is to prevent ops methods from being 2136 * called with bad data. 2137 */ 2138 void 2139 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2140 { 2141 fp->f_data = data; 2142 fp->f_flag = flag; 2143 fp->f_type = type; 2144 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2145 } 2146 2147 struct file * 2148 fget_unlocked(struct filedesc *fdp, int fd) 2149 { 2150 struct file *fp; 2151 u_int count; 2152 2153 if (fd < 0 || fd >= fdp->fd_nfiles) 2154 return (NULL); 2155 /* 2156 * Fetch the descriptor locklessly. We avoid fdrop() races by 2157 * never raising a refcount above 0. To accomplish this we have 2158 * to use a cmpset loop rather than an atomic_add. The descriptor 2159 * must be re-verified once we acquire a reference to be certain 2160 * that the identity is still correct and we did not lose a race 2161 * due to preemption. 2162 */ 2163 for (;;) { 2164 fp = fdp->fd_ofiles[fd]; 2165 if (fp == NULL) 2166 break; 2167 count = fp->f_count; 2168 if (count == 0) 2169 continue; 2170 /* 2171 * Use an acquire barrier to prevent caching of fd_ofiles 2172 * so it is refreshed for verification. 2173 */ 2174 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1) 2175 continue; 2176 if (fp == fdp->fd_ofiles[fd]) 2177 break; 2178 fdrop(fp, curthread); 2179 } 2180 2181 return (fp); 2182 } 2183 2184 /* 2185 * Extract the file pointer associated with the specified descriptor for the 2186 * current user process. 2187 * 2188 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2189 * returned. 2190 * 2191 * If an error occured the non-zero error is returned and *fpp is set to 2192 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2193 * responsible for fdrop(). 2194 */ 2195 static __inline int 2196 _fget(struct thread *td, int fd, struct file **fpp, int flags) 2197 { 2198 struct filedesc *fdp; 2199 struct file *fp; 2200 2201 *fpp = NULL; 2202 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2203 return (EBADF); 2204 if ((fp = fget_unlocked(fdp, fd)) == NULL) 2205 return (EBADF); 2206 if (fp->f_ops == &badfileops) { 2207 fdrop(fp, td); 2208 return (EBADF); 2209 } 2210 /* 2211 * FREAD and FWRITE failure return EBADF as per POSIX. 2212 * 2213 * Only one flag, or 0, may be specified. 2214 */ 2215 if ((flags == FREAD && (fp->f_flag & FREAD) == 0) || 2216 (flags == FWRITE && (fp->f_flag & FWRITE) == 0)) { 2217 fdrop(fp, td); 2218 return (EBADF); 2219 } 2220 *fpp = fp; 2221 return (0); 2222 } 2223 2224 int 2225 fget(struct thread *td, int fd, struct file **fpp) 2226 { 2227 2228 return(_fget(td, fd, fpp, 0)); 2229 } 2230 2231 int 2232 fget_read(struct thread *td, int fd, struct file **fpp) 2233 { 2234 2235 return(_fget(td, fd, fpp, FREAD)); 2236 } 2237 2238 int 2239 fget_write(struct thread *td, int fd, struct file **fpp) 2240 { 2241 2242 return(_fget(td, fd, fpp, FWRITE)); 2243 } 2244 2245 /* 2246 * Like fget() but loads the underlying vnode, or returns an error if the 2247 * descriptor does not represent a vnode. Note that pipes use vnodes but 2248 * never have VM objects. The returned vnode will be vref()'d. 2249 * 2250 * XXX: what about the unused flags ? 2251 */ 2252 static __inline int 2253 _fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags) 2254 { 2255 struct file *fp; 2256 int error; 2257 2258 *vpp = NULL; 2259 if ((error = _fget(td, fd, &fp, flags)) != 0) 2260 return (error); 2261 if (fp->f_vnode == NULL) { 2262 error = EINVAL; 2263 } else { 2264 *vpp = fp->f_vnode; 2265 vref(*vpp); 2266 } 2267 fdrop(fp, td); 2268 2269 return (error); 2270 } 2271 2272 int 2273 fgetvp(struct thread *td, int fd, struct vnode **vpp) 2274 { 2275 2276 return (_fgetvp(td, fd, vpp, 0)); 2277 } 2278 2279 int 2280 fgetvp_read(struct thread *td, int fd, struct vnode **vpp) 2281 { 2282 2283 return (_fgetvp(td, fd, vpp, FREAD)); 2284 } 2285 2286 #ifdef notyet 2287 int 2288 fgetvp_write(struct thread *td, int fd, struct vnode **vpp) 2289 { 2290 2291 return (_fgetvp(td, fd, vpp, FWRITE)); 2292 } 2293 #endif 2294 2295 /* 2296 * Like fget() but loads the underlying socket, or returns an error if the 2297 * descriptor does not represent a socket. 2298 * 2299 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2300 * in the future. 2301 * 2302 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2303 * on their file descriptor reference to prevent the socket from being free'd 2304 * during use. 2305 */ 2306 int 2307 fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp) 2308 { 2309 struct file *fp; 2310 int error; 2311 2312 *spp = NULL; 2313 if (fflagp != NULL) 2314 *fflagp = 0; 2315 if ((error = _fget(td, fd, &fp, 0)) != 0) 2316 return (error); 2317 if (fp->f_type != DTYPE_SOCKET) { 2318 error = ENOTSOCK; 2319 } else { 2320 *spp = fp->f_data; 2321 if (fflagp) 2322 *fflagp = fp->f_flag; 2323 SOCK_LOCK(*spp); 2324 soref(*spp); 2325 SOCK_UNLOCK(*spp); 2326 } 2327 fdrop(fp, td); 2328 2329 return (error); 2330 } 2331 2332 /* 2333 * Drop the reference count on the socket and XXX release the SX lock in the 2334 * future. The last reference closes the socket. 2335 * 2336 * Note: fputsock() is deprecated, see comment for fgetsock(). 2337 */ 2338 void 2339 fputsock(struct socket *so) 2340 { 2341 2342 ACCEPT_LOCK(); 2343 SOCK_LOCK(so); 2344 CURVNET_SET(so->so_vnet); 2345 sorele(so); 2346 CURVNET_RESTORE(); 2347 } 2348 2349 /* 2350 * Handle the last reference to a file being closed. 2351 */ 2352 int 2353 _fdrop(struct file *fp, struct thread *td) 2354 { 2355 int error; 2356 2357 error = 0; 2358 if (fp->f_count != 0) 2359 panic("fdrop: count %d", fp->f_count); 2360 if (fp->f_ops != &badfileops) 2361 error = fo_close(fp, td); 2362 atomic_subtract_int(&openfiles, 1); 2363 crfree(fp->f_cred); 2364 uma_zfree(file_zone, fp); 2365 2366 return (error); 2367 } 2368 2369 /* 2370 * Apply an advisory lock on a file descriptor. 2371 * 2372 * Just attempt to get a record lock of the requested type on the entire file 2373 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2374 */ 2375 #ifndef _SYS_SYSPROTO_H_ 2376 struct flock_args { 2377 int fd; 2378 int how; 2379 }; 2380 #endif 2381 /* ARGSUSED */ 2382 int 2383 flock(struct thread *td, struct flock_args *uap) 2384 { 2385 struct file *fp; 2386 struct vnode *vp; 2387 struct flock lf; 2388 int vfslocked; 2389 int error; 2390 2391 if ((error = fget(td, uap->fd, &fp)) != 0) 2392 return (error); 2393 if (fp->f_type != DTYPE_VNODE) { 2394 fdrop(fp, td); 2395 return (EOPNOTSUPP); 2396 } 2397 2398 vp = fp->f_vnode; 2399 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2400 lf.l_whence = SEEK_SET; 2401 lf.l_start = 0; 2402 lf.l_len = 0; 2403 if (uap->how & LOCK_UN) { 2404 lf.l_type = F_UNLCK; 2405 atomic_clear_int(&fp->f_flag, FHASLOCK); 2406 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2407 goto done2; 2408 } 2409 if (uap->how & LOCK_EX) 2410 lf.l_type = F_WRLCK; 2411 else if (uap->how & LOCK_SH) 2412 lf.l_type = F_RDLCK; 2413 else { 2414 error = EBADF; 2415 goto done2; 2416 } 2417 atomic_set_int(&fp->f_flag, FHASLOCK); 2418 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2419 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2420 done2: 2421 fdrop(fp, td); 2422 VFS_UNLOCK_GIANT(vfslocked); 2423 return (error); 2424 } 2425 /* 2426 * Duplicate the specified descriptor to a free descriptor. 2427 */ 2428 int 2429 dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error) 2430 { 2431 struct file *wfp; 2432 struct file *fp; 2433 2434 /* 2435 * If the to-be-dup'd fd number is greater than the allowed number 2436 * of file descriptors, or the fd to be dup'd has already been 2437 * closed, then reject. 2438 */ 2439 FILEDESC_XLOCK(fdp); 2440 if (dfd < 0 || dfd >= fdp->fd_nfiles || 2441 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 2442 FILEDESC_XUNLOCK(fdp); 2443 return (EBADF); 2444 } 2445 2446 /* 2447 * There are two cases of interest here. 2448 * 2449 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2450 * 2451 * For ENXIO steal away the file structure from (dfd) and store it in 2452 * (indx). (dfd) is effectively closed by this operation. 2453 * 2454 * Any other error code is just returned. 2455 */ 2456 switch (error) { 2457 case ENODEV: 2458 /* 2459 * Check that the mode the file is being opened for is a 2460 * subset of the mode of the existing descriptor. 2461 */ 2462 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2463 FILEDESC_XUNLOCK(fdp); 2464 return (EACCES); 2465 } 2466 fp = fdp->fd_ofiles[indx]; 2467 fdp->fd_ofiles[indx] = wfp; 2468 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2469 if (fp == NULL) 2470 fdused(fdp, indx); 2471 fhold(wfp); 2472 FILEDESC_XUNLOCK(fdp); 2473 if (fp != NULL) 2474 /* 2475 * We now own the reference to fp that the ofiles[] 2476 * array used to own. Release it. 2477 */ 2478 fdrop(fp, td); 2479 return (0); 2480 2481 case ENXIO: 2482 /* 2483 * Steal away the file pointer from dfd and stuff it into indx. 2484 */ 2485 fp = fdp->fd_ofiles[indx]; 2486 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 2487 fdp->fd_ofiles[dfd] = NULL; 2488 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2489 fdp->fd_ofileflags[dfd] = 0; 2490 fdunused(fdp, dfd); 2491 if (fp == NULL) 2492 fdused(fdp, indx); 2493 FILEDESC_XUNLOCK(fdp); 2494 2495 /* 2496 * We now own the reference to fp that the ofiles[] array 2497 * used to own. Release it. 2498 */ 2499 if (fp != NULL) 2500 fdrop(fp, td); 2501 return (0); 2502 2503 default: 2504 FILEDESC_XUNLOCK(fdp); 2505 return (error); 2506 } 2507 /* NOTREACHED */ 2508 } 2509 2510 /* 2511 * Scan all active processes and prisons to see if any of them have a current 2512 * or root directory of `olddp'. If so, replace them with the new mount point. 2513 */ 2514 void 2515 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2516 { 2517 struct filedesc *fdp; 2518 struct prison *pr; 2519 struct proc *p; 2520 int nrele; 2521 2522 if (vrefcnt(olddp) == 1) 2523 return; 2524 nrele = 0; 2525 sx_slock(&allproc_lock); 2526 FOREACH_PROC_IN_SYSTEM(p) { 2527 fdp = fdhold(p); 2528 if (fdp == NULL) 2529 continue; 2530 FILEDESC_XLOCK(fdp); 2531 if (fdp->fd_cdir == olddp) { 2532 vref(newdp); 2533 fdp->fd_cdir = newdp; 2534 nrele++; 2535 } 2536 if (fdp->fd_rdir == olddp) { 2537 vref(newdp); 2538 fdp->fd_rdir = newdp; 2539 nrele++; 2540 } 2541 if (fdp->fd_jdir == olddp) { 2542 vref(newdp); 2543 fdp->fd_jdir = newdp; 2544 nrele++; 2545 } 2546 FILEDESC_XUNLOCK(fdp); 2547 fddrop(fdp); 2548 } 2549 sx_sunlock(&allproc_lock); 2550 if (rootvnode == olddp) { 2551 vref(newdp); 2552 rootvnode = newdp; 2553 nrele++; 2554 } 2555 mtx_lock(&prison0.pr_mtx); 2556 if (prison0.pr_root == olddp) { 2557 vref(newdp); 2558 prison0.pr_root = newdp; 2559 nrele++; 2560 } 2561 mtx_unlock(&prison0.pr_mtx); 2562 sx_slock(&allprison_lock); 2563 TAILQ_FOREACH(pr, &allprison, pr_list) { 2564 mtx_lock(&pr->pr_mtx); 2565 if (pr->pr_root == olddp) { 2566 vref(newdp); 2567 pr->pr_root = newdp; 2568 nrele++; 2569 } 2570 mtx_unlock(&pr->pr_mtx); 2571 } 2572 sx_sunlock(&allprison_lock); 2573 while (nrele--) 2574 vrele(olddp); 2575 } 2576 2577 struct filedesc_to_leader * 2578 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2579 { 2580 struct filedesc_to_leader *fdtol; 2581 2582 fdtol = malloc(sizeof(struct filedesc_to_leader), 2583 M_FILEDESC_TO_LEADER, 2584 M_WAITOK); 2585 fdtol->fdl_refcount = 1; 2586 fdtol->fdl_holdcount = 0; 2587 fdtol->fdl_wakeup = 0; 2588 fdtol->fdl_leader = leader; 2589 if (old != NULL) { 2590 FILEDESC_XLOCK(fdp); 2591 fdtol->fdl_next = old->fdl_next; 2592 fdtol->fdl_prev = old; 2593 old->fdl_next = fdtol; 2594 fdtol->fdl_next->fdl_prev = fdtol; 2595 FILEDESC_XUNLOCK(fdp); 2596 } else { 2597 fdtol->fdl_next = fdtol; 2598 fdtol->fdl_prev = fdtol; 2599 } 2600 return (fdtol); 2601 } 2602 2603 /* 2604 * Get file structures globally. 2605 */ 2606 static int 2607 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2608 { 2609 struct xfile xf; 2610 struct filedesc *fdp; 2611 struct file *fp; 2612 struct proc *p; 2613 int error, n; 2614 2615 error = sysctl_wire_old_buffer(req, 0); 2616 if (error != 0) 2617 return (error); 2618 if (req->oldptr == NULL) { 2619 n = 0; 2620 sx_slock(&allproc_lock); 2621 FOREACH_PROC_IN_SYSTEM(p) { 2622 if (p->p_state == PRS_NEW) 2623 continue; 2624 fdp = fdhold(p); 2625 if (fdp == NULL) 2626 continue; 2627 /* overestimates sparse tables. */ 2628 if (fdp->fd_lastfile > 0) 2629 n += fdp->fd_lastfile; 2630 fddrop(fdp); 2631 } 2632 sx_sunlock(&allproc_lock); 2633 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2634 } 2635 error = 0; 2636 bzero(&xf, sizeof(xf)); 2637 xf.xf_size = sizeof(xf); 2638 sx_slock(&allproc_lock); 2639 FOREACH_PROC_IN_SYSTEM(p) { 2640 PROC_LOCK(p); 2641 if (p->p_state == PRS_NEW) { 2642 PROC_UNLOCK(p); 2643 continue; 2644 } 2645 if (p_cansee(req->td, p) != 0) { 2646 PROC_UNLOCK(p); 2647 continue; 2648 } 2649 xf.xf_pid = p->p_pid; 2650 xf.xf_uid = p->p_ucred->cr_uid; 2651 PROC_UNLOCK(p); 2652 fdp = fdhold(p); 2653 if (fdp == NULL) 2654 continue; 2655 FILEDESC_SLOCK(fdp); 2656 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) { 2657 if ((fp = fdp->fd_ofiles[n]) == NULL) 2658 continue; 2659 xf.xf_fd = n; 2660 xf.xf_file = fp; 2661 xf.xf_data = fp->f_data; 2662 xf.xf_vnode = fp->f_vnode; 2663 xf.xf_type = fp->f_type; 2664 xf.xf_count = fp->f_count; 2665 xf.xf_msgcount = 0; 2666 xf.xf_offset = fp->f_offset; 2667 xf.xf_flag = fp->f_flag; 2668 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2669 if (error) 2670 break; 2671 } 2672 FILEDESC_SUNLOCK(fdp); 2673 fddrop(fdp); 2674 if (error) 2675 break; 2676 } 2677 sx_sunlock(&allproc_lock); 2678 return (error); 2679 } 2680 2681 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2682 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2683 2684 #ifdef KINFO_OFILE_SIZE 2685 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 2686 #endif 2687 2688 #ifdef COMPAT_FREEBSD7 2689 static int 2690 export_vnode_for_osysctl(struct vnode *vp, int type, 2691 struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req) 2692 { 2693 int error; 2694 char *fullpath, *freepath; 2695 int vfslocked; 2696 2697 bzero(kif, sizeof(*kif)); 2698 kif->kf_structsize = sizeof(*kif); 2699 2700 vref(vp); 2701 kif->kf_fd = type; 2702 kif->kf_type = KF_TYPE_VNODE; 2703 /* This function only handles directories. */ 2704 if (vp->v_type != VDIR) { 2705 vrele(vp); 2706 return (ENOTDIR); 2707 } 2708 kif->kf_vnode_type = KF_VTYPE_VDIR; 2709 2710 /* 2711 * This is not a true file descriptor, so we set a bogus refcount 2712 * and offset to indicate these fields should be ignored. 2713 */ 2714 kif->kf_ref_count = -1; 2715 kif->kf_offset = -1; 2716 2717 freepath = NULL; 2718 fullpath = "-"; 2719 FILEDESC_SUNLOCK(fdp); 2720 vn_fullpath(curthread, vp, &fullpath, &freepath); 2721 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2722 vrele(vp); 2723 VFS_UNLOCK_GIANT(vfslocked); 2724 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2725 if (freepath != NULL) 2726 free(freepath, M_TEMP); 2727 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2728 FILEDESC_SLOCK(fdp); 2729 return (error); 2730 } 2731 2732 /* 2733 * Get per-process file descriptors for use by procstat(1), et al. 2734 */ 2735 static int 2736 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 2737 { 2738 char *fullpath, *freepath; 2739 struct kinfo_ofile *kif; 2740 struct filedesc *fdp; 2741 int error, i, *name; 2742 struct socket *so; 2743 struct vnode *vp; 2744 struct file *fp; 2745 struct proc *p; 2746 struct tty *tp; 2747 int vfslocked; 2748 2749 name = (int *)arg1; 2750 if ((p = pfind((pid_t)name[0])) == NULL) 2751 return (ESRCH); 2752 if ((error = p_candebug(curthread, p))) { 2753 PROC_UNLOCK(p); 2754 return (error); 2755 } 2756 fdp = fdhold(p); 2757 PROC_UNLOCK(p); 2758 if (fdp == NULL) 2759 return (ENOENT); 2760 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 2761 FILEDESC_SLOCK(fdp); 2762 if (fdp->fd_cdir != NULL) 2763 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 2764 fdp, req); 2765 if (fdp->fd_rdir != NULL) 2766 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 2767 fdp, req); 2768 if (fdp->fd_jdir != NULL) 2769 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 2770 fdp, req); 2771 for (i = 0; i < fdp->fd_nfiles; i++) { 2772 if ((fp = fdp->fd_ofiles[i]) == NULL) 2773 continue; 2774 bzero(kif, sizeof(*kif)); 2775 kif->kf_structsize = sizeof(*kif); 2776 vp = NULL; 2777 so = NULL; 2778 tp = NULL; 2779 kif->kf_fd = i; 2780 switch (fp->f_type) { 2781 case DTYPE_VNODE: 2782 kif->kf_type = KF_TYPE_VNODE; 2783 vp = fp->f_vnode; 2784 break; 2785 2786 case DTYPE_SOCKET: 2787 kif->kf_type = KF_TYPE_SOCKET; 2788 so = fp->f_data; 2789 break; 2790 2791 case DTYPE_PIPE: 2792 kif->kf_type = KF_TYPE_PIPE; 2793 break; 2794 2795 case DTYPE_FIFO: 2796 kif->kf_type = KF_TYPE_FIFO; 2797 vp = fp->f_vnode; 2798 break; 2799 2800 case DTYPE_KQUEUE: 2801 kif->kf_type = KF_TYPE_KQUEUE; 2802 break; 2803 2804 case DTYPE_CRYPTO: 2805 kif->kf_type = KF_TYPE_CRYPTO; 2806 break; 2807 2808 case DTYPE_MQUEUE: 2809 kif->kf_type = KF_TYPE_MQUEUE; 2810 break; 2811 2812 case DTYPE_SHM: 2813 kif->kf_type = KF_TYPE_SHM; 2814 break; 2815 2816 case DTYPE_SEM: 2817 kif->kf_type = KF_TYPE_SEM; 2818 break; 2819 2820 case DTYPE_PTS: 2821 kif->kf_type = KF_TYPE_PTS; 2822 tp = fp->f_data; 2823 break; 2824 2825 default: 2826 kif->kf_type = KF_TYPE_UNKNOWN; 2827 break; 2828 } 2829 kif->kf_ref_count = fp->f_count; 2830 if (fp->f_flag & FREAD) 2831 kif->kf_flags |= KF_FLAG_READ; 2832 if (fp->f_flag & FWRITE) 2833 kif->kf_flags |= KF_FLAG_WRITE; 2834 if (fp->f_flag & FAPPEND) 2835 kif->kf_flags |= KF_FLAG_APPEND; 2836 if (fp->f_flag & FASYNC) 2837 kif->kf_flags |= KF_FLAG_ASYNC; 2838 if (fp->f_flag & FFSYNC) 2839 kif->kf_flags |= KF_FLAG_FSYNC; 2840 if (fp->f_flag & FNONBLOCK) 2841 kif->kf_flags |= KF_FLAG_NONBLOCK; 2842 if (fp->f_flag & O_DIRECT) 2843 kif->kf_flags |= KF_FLAG_DIRECT; 2844 if (fp->f_flag & FHASLOCK) 2845 kif->kf_flags |= KF_FLAG_HASLOCK; 2846 kif->kf_offset = fp->f_offset; 2847 if (vp != NULL) { 2848 vref(vp); 2849 switch (vp->v_type) { 2850 case VNON: 2851 kif->kf_vnode_type = KF_VTYPE_VNON; 2852 break; 2853 case VREG: 2854 kif->kf_vnode_type = KF_VTYPE_VREG; 2855 break; 2856 case VDIR: 2857 kif->kf_vnode_type = KF_VTYPE_VDIR; 2858 break; 2859 case VBLK: 2860 kif->kf_vnode_type = KF_VTYPE_VBLK; 2861 break; 2862 case VCHR: 2863 kif->kf_vnode_type = KF_VTYPE_VCHR; 2864 break; 2865 case VLNK: 2866 kif->kf_vnode_type = KF_VTYPE_VLNK; 2867 break; 2868 case VSOCK: 2869 kif->kf_vnode_type = KF_VTYPE_VSOCK; 2870 break; 2871 case VFIFO: 2872 kif->kf_vnode_type = KF_VTYPE_VFIFO; 2873 break; 2874 case VBAD: 2875 kif->kf_vnode_type = KF_VTYPE_VBAD; 2876 break; 2877 default: 2878 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 2879 break; 2880 } 2881 /* 2882 * It is OK to drop the filedesc lock here as we will 2883 * re-validate and re-evaluate its properties when 2884 * the loop continues. 2885 */ 2886 freepath = NULL; 2887 fullpath = "-"; 2888 FILEDESC_SUNLOCK(fdp); 2889 vn_fullpath(curthread, vp, &fullpath, &freepath); 2890 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2891 vrele(vp); 2892 VFS_UNLOCK_GIANT(vfslocked); 2893 strlcpy(kif->kf_path, fullpath, 2894 sizeof(kif->kf_path)); 2895 if (freepath != NULL) 2896 free(freepath, M_TEMP); 2897 FILEDESC_SLOCK(fdp); 2898 } 2899 if (so != NULL) { 2900 struct sockaddr *sa; 2901 2902 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 2903 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 2904 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 2905 free(sa, M_SONAME); 2906 } 2907 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 2908 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 2909 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 2910 free(sa, M_SONAME); 2911 } 2912 kif->kf_sock_domain = 2913 so->so_proto->pr_domain->dom_family; 2914 kif->kf_sock_type = so->so_type; 2915 kif->kf_sock_protocol = so->so_proto->pr_protocol; 2916 } 2917 if (tp != NULL) { 2918 strlcpy(kif->kf_path, tty_devname(tp), 2919 sizeof(kif->kf_path)); 2920 } 2921 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2922 if (error) 2923 break; 2924 } 2925 FILEDESC_SUNLOCK(fdp); 2926 fddrop(fdp); 2927 free(kif, M_TEMP); 2928 return (0); 2929 } 2930 2931 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD, 2932 sysctl_kern_proc_ofiledesc, "Process ofiledesc entries"); 2933 #endif /* COMPAT_FREEBSD7 */ 2934 2935 #ifdef KINFO_FILE_SIZE 2936 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 2937 #endif 2938 2939 static int 2940 export_vnode_for_sysctl(struct vnode *vp, int type, 2941 struct kinfo_file *kif, struct filedesc *fdp, struct sysctl_req *req) 2942 { 2943 int error; 2944 char *fullpath, *freepath; 2945 int vfslocked; 2946 2947 bzero(kif, sizeof(*kif)); 2948 2949 vref(vp); 2950 kif->kf_fd = type; 2951 kif->kf_type = KF_TYPE_VNODE; 2952 /* This function only handles directories. */ 2953 if (vp->v_type != VDIR) { 2954 vrele(vp); 2955 return (ENOTDIR); 2956 } 2957 kif->kf_vnode_type = KF_VTYPE_VDIR; 2958 2959 /* 2960 * This is not a true file descriptor, so we set a bogus refcount 2961 * and offset to indicate these fields should be ignored. 2962 */ 2963 kif->kf_ref_count = -1; 2964 kif->kf_offset = -1; 2965 2966 freepath = NULL; 2967 fullpath = "-"; 2968 FILEDESC_SUNLOCK(fdp); 2969 vn_fullpath(curthread, vp, &fullpath, &freepath); 2970 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2971 vrele(vp); 2972 VFS_UNLOCK_GIANT(vfslocked); 2973 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2974 if (freepath != NULL) 2975 free(freepath, M_TEMP); 2976 /* Pack record size down */ 2977 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 2978 strlen(kif->kf_path) + 1; 2979 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 2980 error = SYSCTL_OUT(req, kif, kif->kf_structsize); 2981 FILEDESC_SLOCK(fdp); 2982 return (error); 2983 } 2984 2985 /* 2986 * Get per-process file descriptors for use by procstat(1), et al. 2987 */ 2988 static int 2989 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 2990 { 2991 char *fullpath, *freepath; 2992 struct kinfo_file *kif; 2993 struct filedesc *fdp; 2994 int error, i, *name; 2995 struct socket *so; 2996 struct vnode *vp; 2997 struct file *fp; 2998 struct proc *p; 2999 struct tty *tp; 3000 int vfslocked; 3001 size_t oldidx; 3002 3003 name = (int *)arg1; 3004 if ((p = pfind((pid_t)name[0])) == NULL) 3005 return (ESRCH); 3006 if ((error = p_candebug(curthread, p))) { 3007 PROC_UNLOCK(p); 3008 return (error); 3009 } 3010 fdp = fdhold(p); 3011 PROC_UNLOCK(p); 3012 if (fdp == NULL) 3013 return (ENOENT); 3014 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3015 FILEDESC_SLOCK(fdp); 3016 if (fdp->fd_cdir != NULL) 3017 export_vnode_for_sysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3018 fdp, req); 3019 if (fdp->fd_rdir != NULL) 3020 export_vnode_for_sysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3021 fdp, req); 3022 if (fdp->fd_jdir != NULL) 3023 export_vnode_for_sysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3024 fdp, req); 3025 for (i = 0; i < fdp->fd_nfiles; i++) { 3026 if ((fp = fdp->fd_ofiles[i]) == NULL) 3027 continue; 3028 bzero(kif, sizeof(*kif)); 3029 vp = NULL; 3030 so = NULL; 3031 tp = NULL; 3032 kif->kf_fd = i; 3033 switch (fp->f_type) { 3034 case DTYPE_VNODE: 3035 kif->kf_type = KF_TYPE_VNODE; 3036 vp = fp->f_vnode; 3037 break; 3038 3039 case DTYPE_SOCKET: 3040 kif->kf_type = KF_TYPE_SOCKET; 3041 so = fp->f_data; 3042 break; 3043 3044 case DTYPE_PIPE: 3045 kif->kf_type = KF_TYPE_PIPE; 3046 break; 3047 3048 case DTYPE_FIFO: 3049 kif->kf_type = KF_TYPE_FIFO; 3050 vp = fp->f_vnode; 3051 break; 3052 3053 case DTYPE_KQUEUE: 3054 kif->kf_type = KF_TYPE_KQUEUE; 3055 break; 3056 3057 case DTYPE_CRYPTO: 3058 kif->kf_type = KF_TYPE_CRYPTO; 3059 break; 3060 3061 case DTYPE_MQUEUE: 3062 kif->kf_type = KF_TYPE_MQUEUE; 3063 break; 3064 3065 case DTYPE_SHM: 3066 kif->kf_type = KF_TYPE_SHM; 3067 break; 3068 3069 case DTYPE_SEM: 3070 kif->kf_type = KF_TYPE_SEM; 3071 break; 3072 3073 case DTYPE_PTS: 3074 kif->kf_type = KF_TYPE_PTS; 3075 tp = fp->f_data; 3076 break; 3077 3078 default: 3079 kif->kf_type = KF_TYPE_UNKNOWN; 3080 break; 3081 } 3082 kif->kf_ref_count = fp->f_count; 3083 if (fp->f_flag & FREAD) 3084 kif->kf_flags |= KF_FLAG_READ; 3085 if (fp->f_flag & FWRITE) 3086 kif->kf_flags |= KF_FLAG_WRITE; 3087 if (fp->f_flag & FAPPEND) 3088 kif->kf_flags |= KF_FLAG_APPEND; 3089 if (fp->f_flag & FASYNC) 3090 kif->kf_flags |= KF_FLAG_ASYNC; 3091 if (fp->f_flag & FFSYNC) 3092 kif->kf_flags |= KF_FLAG_FSYNC; 3093 if (fp->f_flag & FNONBLOCK) 3094 kif->kf_flags |= KF_FLAG_NONBLOCK; 3095 if (fp->f_flag & O_DIRECT) 3096 kif->kf_flags |= KF_FLAG_DIRECT; 3097 if (fp->f_flag & FHASLOCK) 3098 kif->kf_flags |= KF_FLAG_HASLOCK; 3099 kif->kf_offset = fp->f_offset; 3100 if (vp != NULL) { 3101 vref(vp); 3102 switch (vp->v_type) { 3103 case VNON: 3104 kif->kf_vnode_type = KF_VTYPE_VNON; 3105 break; 3106 case VREG: 3107 kif->kf_vnode_type = KF_VTYPE_VREG; 3108 break; 3109 case VDIR: 3110 kif->kf_vnode_type = KF_VTYPE_VDIR; 3111 break; 3112 case VBLK: 3113 kif->kf_vnode_type = KF_VTYPE_VBLK; 3114 break; 3115 case VCHR: 3116 kif->kf_vnode_type = KF_VTYPE_VCHR; 3117 break; 3118 case VLNK: 3119 kif->kf_vnode_type = KF_VTYPE_VLNK; 3120 break; 3121 case VSOCK: 3122 kif->kf_vnode_type = KF_VTYPE_VSOCK; 3123 break; 3124 case VFIFO: 3125 kif->kf_vnode_type = KF_VTYPE_VFIFO; 3126 break; 3127 case VBAD: 3128 kif->kf_vnode_type = KF_VTYPE_VBAD; 3129 break; 3130 default: 3131 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 3132 break; 3133 } 3134 /* 3135 * It is OK to drop the filedesc lock here as we will 3136 * re-validate and re-evaluate its properties when 3137 * the loop continues. 3138 */ 3139 freepath = NULL; 3140 fullpath = "-"; 3141 FILEDESC_SUNLOCK(fdp); 3142 vn_fullpath(curthread, vp, &fullpath, &freepath); 3143 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 3144 vrele(vp); 3145 VFS_UNLOCK_GIANT(vfslocked); 3146 strlcpy(kif->kf_path, fullpath, 3147 sizeof(kif->kf_path)); 3148 if (freepath != NULL) 3149 free(freepath, M_TEMP); 3150 FILEDESC_SLOCK(fdp); 3151 } 3152 if (so != NULL) { 3153 struct sockaddr *sa; 3154 3155 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 3156 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 3157 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 3158 free(sa, M_SONAME); 3159 } 3160 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 3161 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 3162 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 3163 free(sa, M_SONAME); 3164 } 3165 kif->kf_sock_domain = 3166 so->so_proto->pr_domain->dom_family; 3167 kif->kf_sock_type = so->so_type; 3168 kif->kf_sock_protocol = so->so_proto->pr_protocol; 3169 } 3170 if (tp != NULL) { 3171 strlcpy(kif->kf_path, tty_devname(tp), 3172 sizeof(kif->kf_path)); 3173 } 3174 /* Pack record size down */ 3175 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3176 strlen(kif->kf_path) + 1; 3177 kif->kf_structsize = roundup(kif->kf_structsize, 3178 sizeof(uint64_t)); 3179 oldidx = req->oldidx; 3180 error = SYSCTL_OUT(req, kif, kif->kf_structsize); 3181 if (error) { 3182 if (error == ENOMEM) { 3183 /* 3184 * The hack to keep the ABI of sysctl 3185 * kern.proc.filedesc intact, but not 3186 * to account a partially copied 3187 * kinfo_file into the oldidx. 3188 */ 3189 req->oldidx = oldidx; 3190 error = 0; 3191 } 3192 break; 3193 } 3194 } 3195 FILEDESC_SUNLOCK(fdp); 3196 fddrop(fdp); 3197 free(kif, M_TEMP); 3198 return (error); 3199 } 3200 3201 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD, 3202 sysctl_kern_proc_filedesc, "Process filedesc entries"); 3203 3204 #ifdef DDB 3205 /* 3206 * For the purposes of debugging, generate a human-readable string for the 3207 * file type. 3208 */ 3209 static const char * 3210 file_type_to_name(short type) 3211 { 3212 3213 switch (type) { 3214 case 0: 3215 return ("zero"); 3216 case DTYPE_VNODE: 3217 return ("vnod"); 3218 case DTYPE_SOCKET: 3219 return ("sock"); 3220 case DTYPE_PIPE: 3221 return ("pipe"); 3222 case DTYPE_FIFO: 3223 return ("fifo"); 3224 case DTYPE_KQUEUE: 3225 return ("kque"); 3226 case DTYPE_CRYPTO: 3227 return ("crpt"); 3228 case DTYPE_MQUEUE: 3229 return ("mque"); 3230 case DTYPE_SHM: 3231 return ("shm"); 3232 case DTYPE_SEM: 3233 return ("ksem"); 3234 default: 3235 return ("unkn"); 3236 } 3237 } 3238 3239 /* 3240 * For the purposes of debugging, identify a process (if any, perhaps one of 3241 * many) that references the passed file in its file descriptor array. Return 3242 * NULL if none. 3243 */ 3244 static struct proc * 3245 file_to_first_proc(struct file *fp) 3246 { 3247 struct filedesc *fdp; 3248 struct proc *p; 3249 int n; 3250 3251 FOREACH_PROC_IN_SYSTEM(p) { 3252 if (p->p_state == PRS_NEW) 3253 continue; 3254 fdp = p->p_fd; 3255 if (fdp == NULL) 3256 continue; 3257 for (n = 0; n < fdp->fd_nfiles; n++) { 3258 if (fp == fdp->fd_ofiles[n]) 3259 return (p); 3260 } 3261 } 3262 return (NULL); 3263 } 3264 3265 static void 3266 db_print_file(struct file *fp, int header) 3267 { 3268 struct proc *p; 3269 3270 if (header) 3271 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3272 "File", "Type", "Data", "Flag", "GCFl", "Count", 3273 "MCount", "Vnode", "FPID", "FCmd"); 3274 p = file_to_first_proc(fp); 3275 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3276 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3277 0, fp->f_count, 0, fp->f_vnode, 3278 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3279 } 3280 3281 DB_SHOW_COMMAND(file, db_show_file) 3282 { 3283 struct file *fp; 3284 3285 if (!have_addr) { 3286 db_printf("usage: show file <addr>\n"); 3287 return; 3288 } 3289 fp = (struct file *)addr; 3290 db_print_file(fp, 1); 3291 } 3292 3293 DB_SHOW_COMMAND(files, db_show_files) 3294 { 3295 struct filedesc *fdp; 3296 struct file *fp; 3297 struct proc *p; 3298 int header; 3299 int n; 3300 3301 header = 1; 3302 FOREACH_PROC_IN_SYSTEM(p) { 3303 if (p->p_state == PRS_NEW) 3304 continue; 3305 if ((fdp = p->p_fd) == NULL) 3306 continue; 3307 for (n = 0; n < fdp->fd_nfiles; ++n) { 3308 if ((fp = fdp->fd_ofiles[n]) == NULL) 3309 continue; 3310 db_print_file(fp, header); 3311 header = 0; 3312 } 3313 } 3314 } 3315 #endif 3316 3317 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3318 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3319 3320 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3321 &maxfiles, 0, "Maximum number of files"); 3322 3323 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3324 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3325 3326 /* ARGSUSED*/ 3327 static void 3328 filelistinit(void *dummy) 3329 { 3330 3331 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3332 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3333 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3334 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3335 } 3336 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3337 3338 /*-------------------------------------------------------------------*/ 3339 3340 static int 3341 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) 3342 { 3343 3344 return (EBADF); 3345 } 3346 3347 static int 3348 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) 3349 { 3350 3351 return (EINVAL); 3352 } 3353 3354 static int 3355 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) 3356 { 3357 3358 return (EBADF); 3359 } 3360 3361 static int 3362 badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) 3363 { 3364 3365 return (0); 3366 } 3367 3368 static int 3369 badfo_kqfilter(struct file *fp, struct knote *kn) 3370 { 3371 3372 return (EBADF); 3373 } 3374 3375 static int 3376 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) 3377 { 3378 3379 return (EBADF); 3380 } 3381 3382 static int 3383 badfo_close(struct file *fp, struct thread *td) 3384 { 3385 3386 return (EBADF); 3387 } 3388 3389 struct fileops badfileops = { 3390 .fo_read = badfo_readwrite, 3391 .fo_write = badfo_readwrite, 3392 .fo_truncate = badfo_truncate, 3393 .fo_ioctl = badfo_ioctl, 3394 .fo_poll = badfo_poll, 3395 .fo_kqfilter = badfo_kqfilter, 3396 .fo_stat = badfo_stat, 3397 .fo_close = badfo_close, 3398 }; 3399 3400 3401 /*-------------------------------------------------------------------*/ 3402 3403 /* 3404 * File Descriptor pseudo-device driver (/dev/fd/). 3405 * 3406 * Opening minor device N dup()s the file (if any) connected to file 3407 * descriptor N belonging to the calling process. Note that this driver 3408 * consists of only the ``open()'' routine, because all subsequent 3409 * references to this file will be direct to the other driver. 3410 * 3411 * XXX: we could give this one a cloning event handler if necessary. 3412 */ 3413 3414 /* ARGSUSED */ 3415 static int 3416 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3417 { 3418 3419 /* 3420 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3421 * the file descriptor being sought for duplication. The error 3422 * return ensures that the vnode for this device will be released 3423 * by vn_open. Open will detect this special error and take the 3424 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3425 * will simply report the error. 3426 */ 3427 td->td_dupfd = dev2unit(dev); 3428 return (ENODEV); 3429 } 3430 3431 static struct cdevsw fildesc_cdevsw = { 3432 .d_version = D_VERSION, 3433 .d_open = fdopen, 3434 .d_name = "FD", 3435 }; 3436 3437 static void 3438 fildesc_drvinit(void *unused) 3439 { 3440 struct cdev *dev; 3441 3442 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3443 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3444 make_dev_alias(dev, "stdin"); 3445 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3446 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3447 make_dev_alias(dev, "stdout"); 3448 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3449 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3450 make_dev_alias(dev, "stderr"); 3451 } 3452 3453 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
Cache object: 5867b5ad9fec8b5dcea638b6e62d4d8c
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