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("$FreeBSD$"); 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/racct.h> 66 #include <sys/resourcevar.h> 67 #include <sys/signalvar.h> 68 #include <sys/socketvar.h> 69 #include <sys/stat.h> 70 #include <sys/sx.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/sysctl.h> 73 #include <sys/sysproto.h> 74 #include <sys/tty.h> 75 #include <sys/unistd.h> 76 #include <sys/user.h> 77 #include <sys/vnode.h> 78 #ifdef KTRACE 79 #include <sys/ktrace.h> 80 #endif 81 82 #include <net/vnet.h> 83 84 #include <security/audit/audit.h> 85 86 #include <vm/uma.h> 87 88 #include <ddb/ddb.h> 89 90 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 91 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 92 "file desc to leader structures"); 93 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 94 95 static uma_zone_t file_zone; 96 97 98 /* Flags for do_dup() */ 99 #define DUP_FIXED 0x1 /* Force fixed allocation */ 100 #define DUP_FCNTL 0x2 /* fcntl()-style errors */ 101 102 static int do_dup(struct thread *td, int flags, int old, int new, 103 register_t *retval); 104 static int fd_first_free(struct filedesc *, int, int); 105 static int fd_last_used(struct filedesc *, int, int); 106 static void fdgrowtable(struct filedesc *, int); 107 static void fdunused(struct filedesc *fdp, int fd); 108 static void fdused(struct filedesc *fdp, int fd); 109 110 /* 111 * A process is initially started out with NDFILE descriptors stored within 112 * this structure, selected to be enough for typical applications based on 113 * the historical limit of 20 open files (and the usage of descriptors by 114 * shells). If these descriptors are exhausted, a larger descriptor table 115 * may be allocated, up to a process' resource limit; the internal arrays 116 * are then unused. 117 */ 118 #define NDFILE 20 119 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 120 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 121 #define NDSLOT(x) ((x) / NDENTRIES) 122 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 123 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 124 125 /* 126 * Storage required per open file descriptor. 127 */ 128 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 129 130 /* 131 * Storage to hold unused ofiles that need to be reclaimed. 132 */ 133 struct freetable { 134 struct file **ft_table; 135 SLIST_ENTRY(freetable) ft_next; 136 }; 137 138 /* 139 * Basic allocation of descriptors: 140 * one of the above, plus arrays for NDFILE descriptors. 141 */ 142 struct filedesc0 { 143 struct filedesc fd_fd; 144 /* 145 * ofiles which need to be reclaimed on free. 146 */ 147 SLIST_HEAD(,freetable) fd_free; 148 /* 149 * These arrays are used when the number of open files is 150 * <= NDFILE, and are then pointed to by the pointers above. 151 */ 152 struct file *fd_dfiles[NDFILE]; 153 char fd_dfileflags[NDFILE]; 154 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 155 }; 156 157 /* 158 * Descriptor management. 159 */ 160 volatile int openfiles; /* actual number of open files */ 161 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 162 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 163 164 /* A mutex to protect the association between a proc and filedesc. */ 165 static struct mtx fdesc_mtx; 166 167 /* 168 * Find the first zero bit in the given bitmap, starting at low and not 169 * exceeding size - 1. 170 */ 171 static int 172 fd_first_free(struct filedesc *fdp, int low, int size) 173 { 174 NDSLOTTYPE *map = fdp->fd_map; 175 NDSLOTTYPE mask; 176 int off, maxoff; 177 178 if (low >= size) 179 return (low); 180 181 off = NDSLOT(low); 182 if (low % NDENTRIES) { 183 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 184 if ((mask &= ~map[off]) != 0UL) 185 return (off * NDENTRIES + ffsl(mask) - 1); 186 ++off; 187 } 188 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 189 if (map[off] != ~0UL) 190 return (off * NDENTRIES + ffsl(~map[off]) - 1); 191 return (size); 192 } 193 194 /* 195 * Find the highest non-zero bit in the given bitmap, starting at low and 196 * not exceeding size - 1. 197 */ 198 static int 199 fd_last_used(struct filedesc *fdp, int low, int size) 200 { 201 NDSLOTTYPE *map = fdp->fd_map; 202 NDSLOTTYPE mask; 203 int off, minoff; 204 205 if (low >= size) 206 return (-1); 207 208 off = NDSLOT(size); 209 if (size % NDENTRIES) { 210 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 211 if ((mask &= map[off]) != 0) 212 return (off * NDENTRIES + flsl(mask) - 1); 213 --off; 214 } 215 for (minoff = NDSLOT(low); off >= minoff; --off) 216 if (map[off] != 0) 217 return (off * NDENTRIES + flsl(map[off]) - 1); 218 return (low - 1); 219 } 220 221 static int 222 fdisused(struct filedesc *fdp, int fd) 223 { 224 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 225 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 226 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 227 } 228 229 /* 230 * Mark a file descriptor as used. 231 */ 232 static void 233 fdused(struct filedesc *fdp, int fd) 234 { 235 236 FILEDESC_XLOCK_ASSERT(fdp); 237 KASSERT(!fdisused(fdp, fd), 238 ("fd already used")); 239 240 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 241 if (fd > fdp->fd_lastfile) 242 fdp->fd_lastfile = fd; 243 if (fd == fdp->fd_freefile) 244 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 245 } 246 247 /* 248 * Mark a file descriptor as unused. 249 */ 250 static void 251 fdunused(struct filedesc *fdp, int fd) 252 { 253 254 FILEDESC_XLOCK_ASSERT(fdp); 255 KASSERT(fdisused(fdp, fd), 256 ("fd is already unused")); 257 KASSERT(fdp->fd_ofiles[fd] == NULL, 258 ("fd is still in use")); 259 260 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 261 if (fd < fdp->fd_freefile) 262 fdp->fd_freefile = fd; 263 if (fd == fdp->fd_lastfile) 264 fdp->fd_lastfile = fd_last_used(fdp, 0, fd); 265 } 266 267 /* 268 * System calls on descriptors. 269 */ 270 #ifndef _SYS_SYSPROTO_H_ 271 struct getdtablesize_args { 272 int dummy; 273 }; 274 #endif 275 /* ARGSUSED */ 276 int 277 getdtablesize(struct thread *td, struct getdtablesize_args *uap) 278 { 279 struct proc *p = td->td_proc; 280 uint64_t lim; 281 282 PROC_LOCK(p); 283 td->td_retval[0] = 284 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 285 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 286 PROC_UNLOCK(p); 287 if (lim < td->td_retval[0]) 288 td->td_retval[0] = lim; 289 return (0); 290 } 291 292 /* 293 * Duplicate a file descriptor to a particular value. 294 * 295 * Note: keep in mind that a potential race condition exists when closing 296 * descriptors from a shared descriptor table (via rfork). 297 */ 298 #ifndef _SYS_SYSPROTO_H_ 299 struct dup2_args { 300 u_int from; 301 u_int to; 302 }; 303 #endif 304 /* ARGSUSED */ 305 int 306 dup2(struct thread *td, struct dup2_args *uap) 307 { 308 309 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 310 td->td_retval)); 311 } 312 313 /* 314 * Duplicate a file descriptor. 315 */ 316 #ifndef _SYS_SYSPROTO_H_ 317 struct dup_args { 318 u_int fd; 319 }; 320 #endif 321 /* ARGSUSED */ 322 int 323 dup(struct thread *td, struct dup_args *uap) 324 { 325 326 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval)); 327 } 328 329 /* 330 * The file control system call. 331 */ 332 #ifndef _SYS_SYSPROTO_H_ 333 struct fcntl_args { 334 int fd; 335 int cmd; 336 long arg; 337 }; 338 #endif 339 /* ARGSUSED */ 340 int 341 fcntl(struct thread *td, struct fcntl_args *uap) 342 { 343 struct flock fl; 344 struct oflock ofl; 345 intptr_t arg; 346 int error; 347 int cmd; 348 349 error = 0; 350 cmd = uap->cmd; 351 switch (uap->cmd) { 352 case F_OGETLK: 353 case F_OSETLK: 354 case F_OSETLKW: 355 /* 356 * Convert old flock structure to new. 357 */ 358 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl)); 359 fl.l_start = ofl.l_start; 360 fl.l_len = ofl.l_len; 361 fl.l_pid = ofl.l_pid; 362 fl.l_type = ofl.l_type; 363 fl.l_whence = ofl.l_whence; 364 fl.l_sysid = 0; 365 366 switch (uap->cmd) { 367 case F_OGETLK: 368 cmd = F_GETLK; 369 break; 370 case F_OSETLK: 371 cmd = F_SETLK; 372 break; 373 case F_OSETLKW: 374 cmd = F_SETLKW; 375 break; 376 } 377 arg = (intptr_t)&fl; 378 break; 379 case F_GETLK: 380 case F_SETLK: 381 case F_SETLKW: 382 case F_SETLK_REMOTE: 383 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl)); 384 arg = (intptr_t)&fl; 385 break; 386 default: 387 arg = uap->arg; 388 break; 389 } 390 if (error) 391 return (error); 392 error = kern_fcntl(td, uap->fd, cmd, arg); 393 if (error) 394 return (error); 395 if (uap->cmd == F_OGETLK) { 396 ofl.l_start = fl.l_start; 397 ofl.l_len = fl.l_len; 398 ofl.l_pid = fl.l_pid; 399 ofl.l_type = fl.l_type; 400 ofl.l_whence = fl.l_whence; 401 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl)); 402 } else if (uap->cmd == F_GETLK) { 403 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl)); 404 } 405 return (error); 406 } 407 408 static inline struct file * 409 fdtofp(int fd, struct filedesc *fdp) 410 { 411 struct file *fp; 412 413 FILEDESC_LOCK_ASSERT(fdp); 414 if ((unsigned)fd >= fdp->fd_nfiles || 415 (fp = fdp->fd_ofiles[fd]) == NULL) 416 return (NULL); 417 return (fp); 418 } 419 420 int 421 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 422 { 423 struct filedesc *fdp; 424 struct flock *flp; 425 struct file *fp; 426 struct proc *p; 427 char *pop; 428 struct vnode *vp; 429 int error, flg, tmp; 430 int vfslocked; 431 u_int old, new; 432 uint64_t bsize; 433 434 vfslocked = 0; 435 error = 0; 436 flg = F_POSIX; 437 p = td->td_proc; 438 fdp = p->p_fd; 439 440 switch (cmd) { 441 case F_DUPFD: 442 tmp = arg; 443 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval); 444 break; 445 446 case F_DUP2FD: 447 tmp = arg; 448 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval); 449 break; 450 451 case F_GETFD: 452 FILEDESC_SLOCK(fdp); 453 if ((fp = fdtofp(fd, fdp)) == NULL) { 454 FILEDESC_SUNLOCK(fdp); 455 error = EBADF; 456 break; 457 } 458 pop = &fdp->fd_ofileflags[fd]; 459 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 460 FILEDESC_SUNLOCK(fdp); 461 break; 462 463 case F_SETFD: 464 FILEDESC_XLOCK(fdp); 465 if ((fp = fdtofp(fd, fdp)) == NULL) { 466 FILEDESC_XUNLOCK(fdp); 467 error = EBADF; 468 break; 469 } 470 pop = &fdp->fd_ofileflags[fd]; 471 *pop = (*pop &~ UF_EXCLOSE) | 472 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 473 FILEDESC_XUNLOCK(fdp); 474 break; 475 476 case F_GETFL: 477 FILEDESC_SLOCK(fdp); 478 if ((fp = fdtofp(fd, fdp)) == NULL) { 479 FILEDESC_SUNLOCK(fdp); 480 error = EBADF; 481 break; 482 } 483 td->td_retval[0] = OFLAGS(fp->f_flag); 484 FILEDESC_SUNLOCK(fdp); 485 break; 486 487 case F_SETFL: 488 FILEDESC_SLOCK(fdp); 489 if ((fp = fdtofp(fd, fdp)) == NULL) { 490 FILEDESC_SUNLOCK(fdp); 491 error = EBADF; 492 break; 493 } 494 fhold(fp); 495 FILEDESC_SUNLOCK(fdp); 496 do { 497 tmp = flg = fp->f_flag; 498 tmp &= ~FCNTLFLAGS; 499 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 500 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 501 tmp = fp->f_flag & FNONBLOCK; 502 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 503 if (error) { 504 fdrop(fp, td); 505 break; 506 } 507 tmp = fp->f_flag & FASYNC; 508 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 509 if (error == 0) { 510 fdrop(fp, td); 511 break; 512 } 513 atomic_clear_int(&fp->f_flag, FNONBLOCK); 514 tmp = 0; 515 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 516 fdrop(fp, td); 517 break; 518 519 case F_GETOWN: 520 FILEDESC_SLOCK(fdp); 521 if ((fp = fdtofp(fd, fdp)) == NULL) { 522 FILEDESC_SUNLOCK(fdp); 523 error = EBADF; 524 break; 525 } 526 fhold(fp); 527 FILEDESC_SUNLOCK(fdp); 528 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 529 if (error == 0) 530 td->td_retval[0] = tmp; 531 fdrop(fp, td); 532 break; 533 534 case F_SETOWN: 535 FILEDESC_SLOCK(fdp); 536 if ((fp = fdtofp(fd, fdp)) == NULL) { 537 FILEDESC_SUNLOCK(fdp); 538 error = EBADF; 539 break; 540 } 541 fhold(fp); 542 FILEDESC_SUNLOCK(fdp); 543 tmp = arg; 544 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 545 fdrop(fp, td); 546 break; 547 548 case F_SETLK_REMOTE: 549 error = priv_check(td, PRIV_NFS_LOCKD); 550 if (error) 551 return (error); 552 flg = F_REMOTE; 553 goto do_setlk; 554 555 case F_SETLKW: 556 flg |= F_WAIT; 557 /* FALLTHROUGH F_SETLK */ 558 559 case F_SETLK: 560 do_setlk: 561 FILEDESC_SLOCK(fdp); 562 if ((fp = fdtofp(fd, fdp)) == NULL) { 563 FILEDESC_SUNLOCK(fdp); 564 error = EBADF; 565 break; 566 } 567 if (fp->f_type != DTYPE_VNODE) { 568 FILEDESC_SUNLOCK(fdp); 569 error = EBADF; 570 break; 571 } 572 flp = (struct flock *)arg; 573 if (flp->l_whence == SEEK_CUR) { 574 if (fp->f_offset < 0 || 575 (flp->l_start > 0 && 576 fp->f_offset > OFF_MAX - flp->l_start)) { 577 FILEDESC_SUNLOCK(fdp); 578 error = EOVERFLOW; 579 break; 580 } 581 flp->l_start += fp->f_offset; 582 } 583 584 /* 585 * VOP_ADVLOCK() may block. 586 */ 587 fhold(fp); 588 FILEDESC_SUNLOCK(fdp); 589 vp = fp->f_vnode; 590 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 591 switch (flp->l_type) { 592 case F_RDLCK: 593 if ((fp->f_flag & FREAD) == 0) { 594 error = EBADF; 595 break; 596 } 597 PROC_LOCK(p->p_leader); 598 p->p_leader->p_flag |= P_ADVLOCK; 599 PROC_UNLOCK(p->p_leader); 600 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 601 flp, flg); 602 break; 603 case F_WRLCK: 604 if ((fp->f_flag & FWRITE) == 0) { 605 error = EBADF; 606 break; 607 } 608 PROC_LOCK(p->p_leader); 609 p->p_leader->p_flag |= P_ADVLOCK; 610 PROC_UNLOCK(p->p_leader); 611 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 612 flp, flg); 613 break; 614 case F_UNLCK: 615 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 616 flp, flg); 617 break; 618 case F_UNLCKSYS: 619 /* 620 * Temporary api for testing remote lock 621 * infrastructure. 622 */ 623 if (flg != F_REMOTE) { 624 error = EINVAL; 625 break; 626 } 627 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 628 F_UNLCKSYS, flp, flg); 629 break; 630 default: 631 error = EINVAL; 632 break; 633 } 634 VFS_UNLOCK_GIANT(vfslocked); 635 vfslocked = 0; 636 /* Check for race with close */ 637 FILEDESC_SLOCK(fdp); 638 if ((unsigned) fd >= fdp->fd_nfiles || 639 fp != fdp->fd_ofiles[fd]) { 640 FILEDESC_SUNLOCK(fdp); 641 flp->l_whence = SEEK_SET; 642 flp->l_start = 0; 643 flp->l_len = 0; 644 flp->l_type = F_UNLCK; 645 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 646 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 647 F_UNLCK, flp, F_POSIX); 648 VFS_UNLOCK_GIANT(vfslocked); 649 vfslocked = 0; 650 } else 651 FILEDESC_SUNLOCK(fdp); 652 fdrop(fp, td); 653 break; 654 655 case F_GETLK: 656 FILEDESC_SLOCK(fdp); 657 if ((fp = fdtofp(fd, fdp)) == NULL) { 658 FILEDESC_SUNLOCK(fdp); 659 error = EBADF; 660 break; 661 } 662 if (fp->f_type != DTYPE_VNODE) { 663 FILEDESC_SUNLOCK(fdp); 664 error = EBADF; 665 break; 666 } 667 flp = (struct flock *)arg; 668 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 669 flp->l_type != F_UNLCK) { 670 FILEDESC_SUNLOCK(fdp); 671 error = EINVAL; 672 break; 673 } 674 if (flp->l_whence == SEEK_CUR) { 675 if ((flp->l_start > 0 && 676 fp->f_offset > OFF_MAX - flp->l_start) || 677 (flp->l_start < 0 && 678 fp->f_offset < OFF_MIN - flp->l_start)) { 679 FILEDESC_SUNLOCK(fdp); 680 error = EOVERFLOW; 681 break; 682 } 683 flp->l_start += fp->f_offset; 684 } 685 /* 686 * VOP_ADVLOCK() may block. 687 */ 688 fhold(fp); 689 FILEDESC_SUNLOCK(fdp); 690 vp = fp->f_vnode; 691 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 692 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 693 F_POSIX); 694 VFS_UNLOCK_GIANT(vfslocked); 695 vfslocked = 0; 696 fdrop(fp, td); 697 break; 698 699 case F_RDAHEAD: 700 arg = arg ? 128 * 1024: 0; 701 /* FALLTHROUGH */ 702 case F_READAHEAD: 703 FILEDESC_SLOCK(fdp); 704 if ((fp = fdtofp(fd, fdp)) == NULL) { 705 FILEDESC_SUNLOCK(fdp); 706 error = EBADF; 707 break; 708 } 709 if (fp->f_type != DTYPE_VNODE) { 710 FILEDESC_SUNLOCK(fdp); 711 error = EBADF; 712 break; 713 } 714 fhold(fp); 715 FILEDESC_SUNLOCK(fdp); 716 if (arg != 0) { 717 vp = fp->f_vnode; 718 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 719 error = vn_lock(vp, LK_SHARED); 720 if (error != 0) 721 goto readahead_vnlock_fail; 722 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 723 VOP_UNLOCK(vp, 0); 724 fp->f_seqcount = (arg + bsize - 1) / bsize; 725 do { 726 new = old = fp->f_flag; 727 new |= FRDAHEAD; 728 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new)); 729 readahead_vnlock_fail: 730 VFS_UNLOCK_GIANT(vfslocked); 731 vfslocked = 0; 732 } else { 733 do { 734 new = old = fp->f_flag; 735 new &= ~FRDAHEAD; 736 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new)); 737 } 738 fdrop(fp, td); 739 break; 740 741 default: 742 error = EINVAL; 743 break; 744 } 745 VFS_UNLOCK_GIANT(vfslocked); 746 return (error); 747 } 748 749 /* 750 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 751 */ 752 static int 753 do_dup(struct thread *td, int flags, int old, int new, 754 register_t *retval) 755 { 756 struct filedesc *fdp; 757 struct proc *p; 758 struct file *fp; 759 struct file *delfp; 760 int error, holdleaders, maxfd; 761 762 p = td->td_proc; 763 fdp = p->p_fd; 764 765 /* 766 * Verify we have a valid descriptor to dup from and possibly to 767 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 768 * return EINVAL when the new descriptor is out of bounds. 769 */ 770 if (old < 0) 771 return (EBADF); 772 if (new < 0) 773 return (flags & DUP_FCNTL ? EINVAL : EBADF); 774 PROC_LOCK(p); 775 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 776 PROC_UNLOCK(p); 777 if (new >= maxfd) 778 return (flags & DUP_FCNTL ? EINVAL : EMFILE); 779 780 FILEDESC_XLOCK(fdp); 781 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 782 FILEDESC_XUNLOCK(fdp); 783 return (EBADF); 784 } 785 if (flags & DUP_FIXED && old == new) { 786 *retval = new; 787 FILEDESC_XUNLOCK(fdp); 788 return (0); 789 } 790 fp = fdp->fd_ofiles[old]; 791 fhold(fp); 792 793 /* 794 * If the caller specified a file descriptor, make sure the file 795 * table is large enough to hold it, and grab it. Otherwise, just 796 * allocate a new descriptor the usual way. Since the filedesc 797 * lock may be temporarily dropped in the process, we have to look 798 * out for a race. 799 */ 800 if (flags & DUP_FIXED) { 801 if (new >= fdp->fd_nfiles) { 802 /* 803 * The resource limits are here instead of e.g. fdalloc(), 804 * because the file descriptor table may be shared between 805 * processes, so we can't really use racct_add()/racct_sub(). 806 * Instead of counting the number of actually allocated 807 * descriptors, just put the limit on the size of the file 808 * descriptor table. 809 */ 810 PROC_LOCK(p); 811 error = racct_set(p, RACCT_NOFILE, new + 1); 812 PROC_UNLOCK(p); 813 if (error != 0) { 814 FILEDESC_XUNLOCK(fdp); 815 fdrop(fp, td); 816 return (EMFILE); 817 } 818 fdgrowtable(fdp, new + 1); 819 } 820 if (fdp->fd_ofiles[new] == NULL) 821 fdused(fdp, new); 822 } else { 823 if ((error = fdalloc(td, new, &new)) != 0) { 824 FILEDESC_XUNLOCK(fdp); 825 fdrop(fp, td); 826 return (error); 827 } 828 } 829 830 /* 831 * If the old file changed out from under us then treat it as a 832 * bad file descriptor. Userland should do its own locking to 833 * avoid this case. 834 */ 835 if (fdp->fd_ofiles[old] != fp) { 836 /* we've allocated a descriptor which we won't use */ 837 if (fdp->fd_ofiles[new] == NULL) 838 fdunused(fdp, new); 839 FILEDESC_XUNLOCK(fdp); 840 fdrop(fp, td); 841 return (EBADF); 842 } 843 KASSERT(old != new, 844 ("new fd is same as old")); 845 846 /* 847 * Save info on the descriptor being overwritten. We cannot close 848 * it without introducing an ownership race for the slot, since we 849 * need to drop the filedesc lock to call closef(). 850 * 851 * XXX this duplicates parts of close(). 852 */ 853 delfp = fdp->fd_ofiles[new]; 854 holdleaders = 0; 855 if (delfp != NULL) { 856 if (td->td_proc->p_fdtol != NULL) { 857 /* 858 * Ask fdfree() to sleep to ensure that all relevant 859 * process leaders can be traversed in closef(). 860 */ 861 fdp->fd_holdleaderscount++; 862 holdleaders = 1; 863 } 864 } 865 866 /* 867 * Duplicate the source descriptor 868 */ 869 fdp->fd_ofiles[new] = fp; 870 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 871 if (new > fdp->fd_lastfile) 872 fdp->fd_lastfile = new; 873 *retval = new; 874 875 /* 876 * If we dup'd over a valid file, we now own the reference to it 877 * and must dispose of it using closef() semantics (as if a 878 * close() were performed on it). 879 * 880 * XXX this duplicates parts of close(). 881 */ 882 if (delfp != NULL) { 883 knote_fdclose(td, new); 884 if (delfp->f_type == DTYPE_MQUEUE) 885 mq_fdclose(td, new, delfp); 886 FILEDESC_XUNLOCK(fdp); 887 (void) closef(delfp, td); 888 if (holdleaders) { 889 FILEDESC_XLOCK(fdp); 890 fdp->fd_holdleaderscount--; 891 if (fdp->fd_holdleaderscount == 0 && 892 fdp->fd_holdleaderswakeup != 0) { 893 fdp->fd_holdleaderswakeup = 0; 894 wakeup(&fdp->fd_holdleaderscount); 895 } 896 FILEDESC_XUNLOCK(fdp); 897 } 898 } else { 899 FILEDESC_XUNLOCK(fdp); 900 } 901 return (0); 902 } 903 904 /* 905 * If sigio is on the list associated with a process or process group, 906 * disable signalling from the device, remove sigio from the list and 907 * free sigio. 908 */ 909 void 910 funsetown(struct sigio **sigiop) 911 { 912 struct sigio *sigio; 913 914 SIGIO_LOCK(); 915 sigio = *sigiop; 916 if (sigio == NULL) { 917 SIGIO_UNLOCK(); 918 return; 919 } 920 *(sigio->sio_myref) = NULL; 921 if ((sigio)->sio_pgid < 0) { 922 struct pgrp *pg = (sigio)->sio_pgrp; 923 PGRP_LOCK(pg); 924 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 925 sigio, sio_pgsigio); 926 PGRP_UNLOCK(pg); 927 } else { 928 struct proc *p = (sigio)->sio_proc; 929 PROC_LOCK(p); 930 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 931 sigio, sio_pgsigio); 932 PROC_UNLOCK(p); 933 } 934 SIGIO_UNLOCK(); 935 crfree(sigio->sio_ucred); 936 free(sigio, M_SIGIO); 937 } 938 939 /* 940 * Free a list of sigio structures. 941 * We only need to lock the SIGIO_LOCK because we have made ourselves 942 * inaccessible to callers of fsetown and therefore do not need to lock 943 * the proc or pgrp struct for the list manipulation. 944 */ 945 void 946 funsetownlst(struct sigiolst *sigiolst) 947 { 948 struct proc *p; 949 struct pgrp *pg; 950 struct sigio *sigio; 951 952 sigio = SLIST_FIRST(sigiolst); 953 if (sigio == NULL) 954 return; 955 p = NULL; 956 pg = NULL; 957 958 /* 959 * Every entry of the list should belong 960 * to a single proc or pgrp. 961 */ 962 if (sigio->sio_pgid < 0) { 963 pg = sigio->sio_pgrp; 964 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 965 } else /* if (sigio->sio_pgid > 0) */ { 966 p = sigio->sio_proc; 967 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 968 } 969 970 SIGIO_LOCK(); 971 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 972 *(sigio->sio_myref) = NULL; 973 if (pg != NULL) { 974 KASSERT(sigio->sio_pgid < 0, 975 ("Proc sigio in pgrp sigio list")); 976 KASSERT(sigio->sio_pgrp == pg, 977 ("Bogus pgrp in sigio list")); 978 PGRP_LOCK(pg); 979 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 980 sio_pgsigio); 981 PGRP_UNLOCK(pg); 982 } else /* if (p != NULL) */ { 983 KASSERT(sigio->sio_pgid > 0, 984 ("Pgrp sigio in proc sigio list")); 985 KASSERT(sigio->sio_proc == p, 986 ("Bogus proc in sigio list")); 987 PROC_LOCK(p); 988 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 989 sio_pgsigio); 990 PROC_UNLOCK(p); 991 } 992 SIGIO_UNLOCK(); 993 crfree(sigio->sio_ucred); 994 free(sigio, M_SIGIO); 995 SIGIO_LOCK(); 996 } 997 SIGIO_UNLOCK(); 998 } 999 1000 /* 1001 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1002 * 1003 * After permission checking, add a sigio structure to the sigio list for 1004 * the process or process group. 1005 */ 1006 int 1007 fsetown(pid_t pgid, struct sigio **sigiop) 1008 { 1009 struct proc *proc; 1010 struct pgrp *pgrp; 1011 struct sigio *sigio; 1012 int ret; 1013 1014 if (pgid == 0) { 1015 funsetown(sigiop); 1016 return (0); 1017 } 1018 1019 ret = 0; 1020 1021 /* Allocate and fill in the new sigio out of locks. */ 1022 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1023 sigio->sio_pgid = pgid; 1024 sigio->sio_ucred = crhold(curthread->td_ucred); 1025 sigio->sio_myref = sigiop; 1026 1027 sx_slock(&proctree_lock); 1028 if (pgid > 0) { 1029 proc = pfind(pgid); 1030 if (proc == NULL) { 1031 ret = ESRCH; 1032 goto fail; 1033 } 1034 1035 /* 1036 * Policy - Don't allow a process to FSETOWN a process 1037 * in another session. 1038 * 1039 * Remove this test to allow maximum flexibility or 1040 * restrict FSETOWN to the current process or process 1041 * group for maximum safety. 1042 */ 1043 PROC_UNLOCK(proc); 1044 if (proc->p_session != curthread->td_proc->p_session) { 1045 ret = EPERM; 1046 goto fail; 1047 } 1048 1049 pgrp = NULL; 1050 } else /* if (pgid < 0) */ { 1051 pgrp = pgfind(-pgid); 1052 if (pgrp == NULL) { 1053 ret = ESRCH; 1054 goto fail; 1055 } 1056 PGRP_UNLOCK(pgrp); 1057 1058 /* 1059 * Policy - Don't allow a process to FSETOWN a process 1060 * in another session. 1061 * 1062 * Remove this test to allow maximum flexibility or 1063 * restrict FSETOWN to the current process or process 1064 * group for maximum safety. 1065 */ 1066 if (pgrp->pg_session != curthread->td_proc->p_session) { 1067 ret = EPERM; 1068 goto fail; 1069 } 1070 1071 proc = NULL; 1072 } 1073 funsetown(sigiop); 1074 if (pgid > 0) { 1075 PROC_LOCK(proc); 1076 /* 1077 * Since funsetownlst() is called without the proctree 1078 * locked, we need to check for P_WEXIT. 1079 * XXX: is ESRCH correct? 1080 */ 1081 if ((proc->p_flag & P_WEXIT) != 0) { 1082 PROC_UNLOCK(proc); 1083 ret = ESRCH; 1084 goto fail; 1085 } 1086 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1087 sigio->sio_proc = proc; 1088 PROC_UNLOCK(proc); 1089 } else { 1090 PGRP_LOCK(pgrp); 1091 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1092 sigio->sio_pgrp = pgrp; 1093 PGRP_UNLOCK(pgrp); 1094 } 1095 sx_sunlock(&proctree_lock); 1096 SIGIO_LOCK(); 1097 *sigiop = sigio; 1098 SIGIO_UNLOCK(); 1099 return (0); 1100 1101 fail: 1102 sx_sunlock(&proctree_lock); 1103 crfree(sigio->sio_ucred); 1104 free(sigio, M_SIGIO); 1105 return (ret); 1106 } 1107 1108 /* 1109 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1110 */ 1111 pid_t 1112 fgetown(sigiop) 1113 struct sigio **sigiop; 1114 { 1115 pid_t pgid; 1116 1117 SIGIO_LOCK(); 1118 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1119 SIGIO_UNLOCK(); 1120 return (pgid); 1121 } 1122 1123 /* 1124 * Close a file descriptor. 1125 */ 1126 #ifndef _SYS_SYSPROTO_H_ 1127 struct close_args { 1128 int fd; 1129 }; 1130 #endif 1131 /* ARGSUSED */ 1132 int 1133 close(td, uap) 1134 struct thread *td; 1135 struct close_args *uap; 1136 { 1137 1138 return (kern_close(td, uap->fd)); 1139 } 1140 1141 int 1142 kern_close(td, fd) 1143 struct thread *td; 1144 int fd; 1145 { 1146 struct filedesc *fdp; 1147 struct file *fp; 1148 int error; 1149 int holdleaders; 1150 1151 error = 0; 1152 holdleaders = 0; 1153 fdp = td->td_proc->p_fd; 1154 1155 AUDIT_SYSCLOSE(td, fd); 1156 1157 FILEDESC_XLOCK(fdp); 1158 if ((unsigned)fd >= fdp->fd_nfiles || 1159 (fp = fdp->fd_ofiles[fd]) == NULL) { 1160 FILEDESC_XUNLOCK(fdp); 1161 return (EBADF); 1162 } 1163 fdp->fd_ofiles[fd] = NULL; 1164 fdp->fd_ofileflags[fd] = 0; 1165 fdunused(fdp, fd); 1166 if (td->td_proc->p_fdtol != NULL) { 1167 /* 1168 * Ask fdfree() to sleep to ensure that all relevant 1169 * process leaders can be traversed in closef(). 1170 */ 1171 fdp->fd_holdleaderscount++; 1172 holdleaders = 1; 1173 } 1174 1175 /* 1176 * We now hold the fp reference that used to be owned by the 1177 * descriptor array. We have to unlock the FILEDESC *AFTER* 1178 * knote_fdclose to prevent a race of the fd getting opened, a knote 1179 * added, and deleteing a knote for the new fd. 1180 */ 1181 knote_fdclose(td, fd); 1182 if (fp->f_type == DTYPE_MQUEUE) 1183 mq_fdclose(td, fd, fp); 1184 FILEDESC_XUNLOCK(fdp); 1185 1186 error = closef(fp, td); 1187 if (holdleaders) { 1188 FILEDESC_XLOCK(fdp); 1189 fdp->fd_holdleaderscount--; 1190 if (fdp->fd_holdleaderscount == 0 && 1191 fdp->fd_holdleaderswakeup != 0) { 1192 fdp->fd_holdleaderswakeup = 0; 1193 wakeup(&fdp->fd_holdleaderscount); 1194 } 1195 FILEDESC_XUNLOCK(fdp); 1196 } 1197 return (error); 1198 } 1199 1200 /* 1201 * Close open file descriptors. 1202 */ 1203 #ifndef _SYS_SYSPROTO_H_ 1204 struct closefrom_args { 1205 int lowfd; 1206 }; 1207 #endif 1208 /* ARGSUSED */ 1209 int 1210 closefrom(struct thread *td, struct closefrom_args *uap) 1211 { 1212 struct filedesc *fdp; 1213 int fd; 1214 1215 fdp = td->td_proc->p_fd; 1216 AUDIT_ARG_FD(uap->lowfd); 1217 1218 /* 1219 * Treat negative starting file descriptor values identical to 1220 * closefrom(0) which closes all files. 1221 */ 1222 if (uap->lowfd < 0) 1223 uap->lowfd = 0; 1224 FILEDESC_SLOCK(fdp); 1225 for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) { 1226 if (fdp->fd_ofiles[fd] != NULL) { 1227 FILEDESC_SUNLOCK(fdp); 1228 (void)kern_close(td, fd); 1229 FILEDESC_SLOCK(fdp); 1230 } 1231 } 1232 FILEDESC_SUNLOCK(fdp); 1233 return (0); 1234 } 1235 1236 #if defined(COMPAT_43) 1237 /* 1238 * Return status information about a file descriptor. 1239 */ 1240 #ifndef _SYS_SYSPROTO_H_ 1241 struct ofstat_args { 1242 int fd; 1243 struct ostat *sb; 1244 }; 1245 #endif 1246 /* ARGSUSED */ 1247 int 1248 ofstat(struct thread *td, struct ofstat_args *uap) 1249 { 1250 struct ostat oub; 1251 struct stat ub; 1252 int error; 1253 1254 error = kern_fstat(td, uap->fd, &ub); 1255 if (error == 0) { 1256 cvtstat(&ub, &oub); 1257 error = copyout(&oub, uap->sb, sizeof(oub)); 1258 } 1259 return (error); 1260 } 1261 #endif /* COMPAT_43 */ 1262 1263 /* 1264 * Return status information about a file descriptor. 1265 */ 1266 #ifndef _SYS_SYSPROTO_H_ 1267 struct fstat_args { 1268 int fd; 1269 struct stat *sb; 1270 }; 1271 #endif 1272 /* ARGSUSED */ 1273 int 1274 fstat(struct thread *td, struct fstat_args *uap) 1275 { 1276 struct stat ub; 1277 int error; 1278 1279 error = kern_fstat(td, uap->fd, &ub); 1280 if (error == 0) 1281 error = copyout(&ub, uap->sb, sizeof(ub)); 1282 return (error); 1283 } 1284 1285 int 1286 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1287 { 1288 struct file *fp; 1289 int error; 1290 1291 AUDIT_ARG_FD(fd); 1292 1293 if ((error = fget(td, fd, &fp)) != 0) 1294 return (error); 1295 1296 AUDIT_ARG_FILE(td->td_proc, fp); 1297 1298 error = fo_stat(fp, sbp, td->td_ucred, td); 1299 fdrop(fp, td); 1300 #ifdef KTRACE 1301 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1302 ktrstat(sbp); 1303 #endif 1304 return (error); 1305 } 1306 1307 /* 1308 * Return status information about a file descriptor. 1309 */ 1310 #ifndef _SYS_SYSPROTO_H_ 1311 struct nfstat_args { 1312 int fd; 1313 struct nstat *sb; 1314 }; 1315 #endif 1316 /* ARGSUSED */ 1317 int 1318 nfstat(struct thread *td, struct nfstat_args *uap) 1319 { 1320 struct nstat nub; 1321 struct stat ub; 1322 int error; 1323 1324 error = kern_fstat(td, uap->fd, &ub); 1325 if (error == 0) { 1326 cvtnstat(&ub, &nub); 1327 error = copyout(&nub, uap->sb, sizeof(nub)); 1328 } 1329 return (error); 1330 } 1331 1332 /* 1333 * Return pathconf information about a file descriptor. 1334 */ 1335 #ifndef _SYS_SYSPROTO_H_ 1336 struct fpathconf_args { 1337 int fd; 1338 int name; 1339 }; 1340 #endif 1341 /* ARGSUSED */ 1342 int 1343 fpathconf(struct thread *td, struct fpathconf_args *uap) 1344 { 1345 struct file *fp; 1346 struct vnode *vp; 1347 int error; 1348 1349 if ((error = fget(td, uap->fd, &fp)) != 0) 1350 return (error); 1351 1352 /* If asynchronous I/O is available, it works for all descriptors. */ 1353 if (uap->name == _PC_ASYNC_IO) { 1354 td->td_retval[0] = async_io_version; 1355 goto out; 1356 } 1357 vp = fp->f_vnode; 1358 if (vp != NULL) { 1359 int vfslocked; 1360 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1361 vn_lock(vp, LK_SHARED | LK_RETRY); 1362 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1363 VOP_UNLOCK(vp, 0); 1364 VFS_UNLOCK_GIANT(vfslocked); 1365 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1366 if (uap->name != _PC_PIPE_BUF) { 1367 error = EINVAL; 1368 } else { 1369 td->td_retval[0] = PIPE_BUF; 1370 error = 0; 1371 } 1372 } else { 1373 error = EOPNOTSUPP; 1374 } 1375 out: 1376 fdrop(fp, td); 1377 return (error); 1378 } 1379 1380 /* 1381 * Grow the file table to accomodate (at least) nfd descriptors. This may 1382 * block and drop the filedesc lock, but it will reacquire it before 1383 * returning. 1384 */ 1385 static void 1386 fdgrowtable(struct filedesc *fdp, int nfd) 1387 { 1388 struct filedesc0 *fdp0; 1389 struct freetable *fo; 1390 struct file **ntable; 1391 struct file **otable; 1392 char *nfileflags; 1393 int nnfiles, onfiles; 1394 NDSLOTTYPE *nmap; 1395 1396 FILEDESC_XLOCK_ASSERT(fdp); 1397 1398 KASSERT(fdp->fd_nfiles > 0, 1399 ("zero-length file table")); 1400 1401 /* compute the size of the new table */ 1402 onfiles = fdp->fd_nfiles; 1403 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1404 if (nnfiles <= onfiles) 1405 /* the table is already large enough */ 1406 return; 1407 1408 /* allocate a new table and (if required) new bitmaps */ 1409 FILEDESC_XUNLOCK(fdp); 1410 ntable = malloc((nnfiles * OFILESIZE) + sizeof(struct freetable), 1411 M_FILEDESC, M_ZERO | M_WAITOK); 1412 nfileflags = (char *)&ntable[nnfiles]; 1413 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) 1414 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, 1415 M_FILEDESC, M_ZERO | M_WAITOK); 1416 else 1417 nmap = NULL; 1418 FILEDESC_XLOCK(fdp); 1419 1420 /* 1421 * We now have new tables ready to go. Since we dropped the 1422 * filedesc lock to call malloc(), watch out for a race. 1423 */ 1424 onfiles = fdp->fd_nfiles; 1425 if (onfiles >= nnfiles) { 1426 /* we lost the race, but that's OK */ 1427 free(ntable, M_FILEDESC); 1428 if (nmap != NULL) 1429 free(nmap, M_FILEDESC); 1430 return; 1431 } 1432 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable)); 1433 bcopy(fdp->fd_ofileflags, nfileflags, onfiles); 1434 otable = fdp->fd_ofiles; 1435 fdp->fd_ofileflags = nfileflags; 1436 fdp->fd_ofiles = ntable; 1437 /* 1438 * We must preserve ofiles until the process exits because we can't 1439 * be certain that no threads have references to the old table via 1440 * _fget(). 1441 */ 1442 if (onfiles > NDFILE) { 1443 fo = (struct freetable *)&otable[onfiles]; 1444 fdp0 = (struct filedesc0 *)fdp; 1445 fo->ft_table = otable; 1446 SLIST_INSERT_HEAD(&fdp0->fd_free, fo, ft_next); 1447 } 1448 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1449 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap)); 1450 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1451 free(fdp->fd_map, M_FILEDESC); 1452 fdp->fd_map = nmap; 1453 } 1454 fdp->fd_nfiles = nnfiles; 1455 } 1456 1457 /* 1458 * Allocate a file descriptor for the process. 1459 */ 1460 int 1461 fdalloc(struct thread *td, int minfd, int *result) 1462 { 1463 struct proc *p = td->td_proc; 1464 struct filedesc *fdp = p->p_fd; 1465 int fd = -1, maxfd, error; 1466 1467 FILEDESC_XLOCK_ASSERT(fdp); 1468 1469 if (fdp->fd_freefile > minfd) 1470 minfd = fdp->fd_freefile; 1471 1472 PROC_LOCK(p); 1473 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1474 PROC_UNLOCK(p); 1475 1476 /* 1477 * Search the bitmap for a free descriptor. If none is found, try 1478 * to grow the file table. Keep at it until we either get a file 1479 * descriptor or run into process or system limits; fdgrowtable() 1480 * may drop the filedesc lock, so we're in a race. 1481 */ 1482 for (;;) { 1483 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1484 if (fd >= maxfd) 1485 return (EMFILE); 1486 if (fd < fdp->fd_nfiles) 1487 break; 1488 PROC_LOCK(p); 1489 error = racct_set(p, RACCT_NOFILE, min(fdp->fd_nfiles * 2, maxfd)); 1490 PROC_UNLOCK(p); 1491 if (error != 0) 1492 return (EMFILE); 1493 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd)); 1494 } 1495 1496 /* 1497 * Perform some sanity checks, then mark the file descriptor as 1498 * used and return it to the caller. 1499 */ 1500 KASSERT(!fdisused(fdp, fd), 1501 ("fd_first_free() returned non-free descriptor")); 1502 KASSERT(fdp->fd_ofiles[fd] == NULL, 1503 ("free descriptor isn't")); 1504 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */ 1505 fdused(fdp, fd); 1506 *result = fd; 1507 return (0); 1508 } 1509 1510 /* 1511 * Check to see whether n user file descriptors are available to the process 1512 * p. 1513 */ 1514 int 1515 fdavail(struct thread *td, int n) 1516 { 1517 struct proc *p = td->td_proc; 1518 struct filedesc *fdp = td->td_proc->p_fd; 1519 struct file **fpp; 1520 int i, lim, last; 1521 1522 FILEDESC_LOCK_ASSERT(fdp); 1523 1524 /* 1525 * XXX: This is only called from uipc_usrreq.c:unp_externalize(); 1526 * call racct_add() from there instead of dealing with containers 1527 * here. 1528 */ 1529 PROC_LOCK(p); 1530 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1531 PROC_UNLOCK(p); 1532 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1533 return (1); 1534 last = min(fdp->fd_nfiles, lim); 1535 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 1536 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 1537 if (*fpp == NULL && --n <= 0) 1538 return (1); 1539 } 1540 return (0); 1541 } 1542 1543 /* 1544 * Create a new open file structure and allocate a file decriptor for the 1545 * process that refers to it. We add one reference to the file for the 1546 * descriptor table and one reference for resultfp. This is to prevent us 1547 * being preempted and the entry in the descriptor table closed after we 1548 * release the FILEDESC lock. 1549 */ 1550 int 1551 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1552 { 1553 struct proc *p = td->td_proc; 1554 struct file *fp; 1555 int error, i; 1556 int maxuserfiles = maxfiles - (maxfiles / 20); 1557 static struct timeval lastfail; 1558 static int curfail; 1559 1560 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1561 if ((openfiles >= maxuserfiles && 1562 priv_check(td, PRIV_MAXFILES) != 0) || 1563 openfiles >= maxfiles) { 1564 if (ppsratecheck(&lastfail, &curfail, 1)) { 1565 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n", 1566 td->td_ucred->cr_ruid); 1567 } 1568 uma_zfree(file_zone, fp); 1569 return (ENFILE); 1570 } 1571 atomic_add_int(&openfiles, 1); 1572 1573 /* 1574 * If the process has file descriptor zero open, add the new file 1575 * descriptor to the list of open files at that point, otherwise 1576 * put it at the front of the list of open files. 1577 */ 1578 refcount_init(&fp->f_count, 1); 1579 if (resultfp) 1580 fhold(fp); 1581 fp->f_cred = crhold(td->td_ucred); 1582 fp->f_ops = &badfileops; 1583 fp->f_data = NULL; 1584 fp->f_vnode = NULL; 1585 FILEDESC_XLOCK(p->p_fd); 1586 if ((error = fdalloc(td, 0, &i))) { 1587 FILEDESC_XUNLOCK(p->p_fd); 1588 fdrop(fp, td); 1589 if (resultfp) 1590 fdrop(fp, td); 1591 return (error); 1592 } 1593 p->p_fd->fd_ofiles[i] = fp; 1594 if ((flags & O_CLOEXEC) != 0) 1595 p->p_fd->fd_ofileflags[i] |= UF_EXCLOSE; 1596 FILEDESC_XUNLOCK(p->p_fd); 1597 if (resultfp) 1598 *resultfp = fp; 1599 if (resultfd) 1600 *resultfd = i; 1601 return (0); 1602 } 1603 1604 /* 1605 * Build a new filedesc structure from another. 1606 * Copy the current, root, and jail root vnode references. 1607 */ 1608 struct filedesc * 1609 fdinit(struct filedesc *fdp) 1610 { 1611 struct filedesc0 *newfdp; 1612 1613 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO); 1614 FILEDESC_LOCK_INIT(&newfdp->fd_fd); 1615 if (fdp != NULL) { 1616 FILEDESC_XLOCK(fdp); 1617 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1618 if (newfdp->fd_fd.fd_cdir) 1619 VREF(newfdp->fd_fd.fd_cdir); 1620 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1621 if (newfdp->fd_fd.fd_rdir) 1622 VREF(newfdp->fd_fd.fd_rdir); 1623 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1624 if (newfdp->fd_fd.fd_jdir) 1625 VREF(newfdp->fd_fd.fd_jdir); 1626 FILEDESC_XUNLOCK(fdp); 1627 } 1628 1629 /* Create the file descriptor table. */ 1630 newfdp->fd_fd.fd_refcnt = 1; 1631 newfdp->fd_fd.fd_holdcnt = 1; 1632 newfdp->fd_fd.fd_cmask = CMASK; 1633 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1634 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1635 newfdp->fd_fd.fd_nfiles = NDFILE; 1636 newfdp->fd_fd.fd_map = newfdp->fd_dmap; 1637 newfdp->fd_fd.fd_lastfile = -1; 1638 return (&newfdp->fd_fd); 1639 } 1640 1641 static struct filedesc * 1642 fdhold(struct proc *p) 1643 { 1644 struct filedesc *fdp; 1645 1646 mtx_lock(&fdesc_mtx); 1647 fdp = p->p_fd; 1648 if (fdp != NULL) 1649 fdp->fd_holdcnt++; 1650 mtx_unlock(&fdesc_mtx); 1651 return (fdp); 1652 } 1653 1654 static void 1655 fddrop(struct filedesc *fdp) 1656 { 1657 struct filedesc0 *fdp0; 1658 struct freetable *ft; 1659 int i; 1660 1661 mtx_lock(&fdesc_mtx); 1662 i = --fdp->fd_holdcnt; 1663 mtx_unlock(&fdesc_mtx); 1664 if (i > 0) 1665 return; 1666 1667 FILEDESC_LOCK_DESTROY(fdp); 1668 fdp0 = (struct filedesc0 *)fdp; 1669 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) { 1670 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next); 1671 free(ft->ft_table, M_FILEDESC); 1672 } 1673 free(fdp, M_FILEDESC); 1674 } 1675 1676 /* 1677 * Share a filedesc structure. 1678 */ 1679 struct filedesc * 1680 fdshare(struct filedesc *fdp) 1681 { 1682 1683 FILEDESC_XLOCK(fdp); 1684 fdp->fd_refcnt++; 1685 FILEDESC_XUNLOCK(fdp); 1686 return (fdp); 1687 } 1688 1689 /* 1690 * Unshare a filedesc structure, if necessary by making a copy 1691 */ 1692 void 1693 fdunshare(struct proc *p, struct thread *td) 1694 { 1695 1696 FILEDESC_XLOCK(p->p_fd); 1697 if (p->p_fd->fd_refcnt > 1) { 1698 struct filedesc *tmp; 1699 1700 FILEDESC_XUNLOCK(p->p_fd); 1701 tmp = fdcopy(p->p_fd); 1702 fdfree(td); 1703 p->p_fd = tmp; 1704 } else 1705 FILEDESC_XUNLOCK(p->p_fd); 1706 } 1707 1708 /* 1709 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1710 * this is to ease callers, not catch errors. 1711 */ 1712 struct filedesc * 1713 fdcopy(struct filedesc *fdp) 1714 { 1715 struct filedesc *newfdp; 1716 int i; 1717 1718 /* Certain daemons might not have file descriptors. */ 1719 if (fdp == NULL) 1720 return (NULL); 1721 1722 newfdp = fdinit(fdp); 1723 FILEDESC_SLOCK(fdp); 1724 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1725 FILEDESC_SUNLOCK(fdp); 1726 FILEDESC_XLOCK(newfdp); 1727 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1728 FILEDESC_XUNLOCK(newfdp); 1729 FILEDESC_SLOCK(fdp); 1730 } 1731 /* copy everything except kqueue descriptors */ 1732 newfdp->fd_freefile = -1; 1733 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1734 if (fdisused(fdp, i) && 1735 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE && 1736 fdp->fd_ofiles[i]->f_ops != &badfileops) { 1737 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i]; 1738 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i]; 1739 fhold(newfdp->fd_ofiles[i]); 1740 newfdp->fd_lastfile = i; 1741 } else { 1742 if (newfdp->fd_freefile == -1) 1743 newfdp->fd_freefile = i; 1744 } 1745 } 1746 newfdp->fd_cmask = fdp->fd_cmask; 1747 FILEDESC_SUNLOCK(fdp); 1748 FILEDESC_XLOCK(newfdp); 1749 for (i = 0; i <= newfdp->fd_lastfile; ++i) 1750 if (newfdp->fd_ofiles[i] != NULL) 1751 fdused(newfdp, i); 1752 if (newfdp->fd_freefile == -1) 1753 newfdp->fd_freefile = i; 1754 FILEDESC_XUNLOCK(newfdp); 1755 return (newfdp); 1756 } 1757 1758 /* 1759 * Release a filedesc structure. 1760 */ 1761 void 1762 fdfree(struct thread *td) 1763 { 1764 struct filedesc *fdp; 1765 struct file **fpp; 1766 int i, locked; 1767 struct filedesc_to_leader *fdtol; 1768 struct file *fp; 1769 struct vnode *cdir, *jdir, *rdir, *vp; 1770 struct flock lf; 1771 1772 /* Certain daemons might not have file descriptors. */ 1773 fdp = td->td_proc->p_fd; 1774 if (fdp == NULL) 1775 return; 1776 1777 PROC_LOCK(td->td_proc); 1778 racct_set(td->td_proc, RACCT_NOFILE, 0); 1779 PROC_UNLOCK(td->td_proc); 1780 1781 /* Check for special need to clear POSIX style locks */ 1782 fdtol = td->td_proc->p_fdtol; 1783 if (fdtol != NULL) { 1784 FILEDESC_XLOCK(fdp); 1785 KASSERT(fdtol->fdl_refcount > 0, 1786 ("filedesc_to_refcount botch: fdl_refcount=%d", 1787 fdtol->fdl_refcount)); 1788 if (fdtol->fdl_refcount == 1 && 1789 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1790 for (i = 0, fpp = fdp->fd_ofiles; 1791 i <= fdp->fd_lastfile; 1792 i++, fpp++) { 1793 if (*fpp == NULL || 1794 (*fpp)->f_type != DTYPE_VNODE) 1795 continue; 1796 fp = *fpp; 1797 fhold(fp); 1798 FILEDESC_XUNLOCK(fdp); 1799 lf.l_whence = SEEK_SET; 1800 lf.l_start = 0; 1801 lf.l_len = 0; 1802 lf.l_type = F_UNLCK; 1803 vp = fp->f_vnode; 1804 locked = VFS_LOCK_GIANT(vp->v_mount); 1805 (void) VOP_ADVLOCK(vp, 1806 (caddr_t)td->td_proc-> 1807 p_leader, 1808 F_UNLCK, 1809 &lf, 1810 F_POSIX); 1811 VFS_UNLOCK_GIANT(locked); 1812 FILEDESC_XLOCK(fdp); 1813 fdrop(fp, td); 1814 fpp = fdp->fd_ofiles + i; 1815 } 1816 } 1817 retry: 1818 if (fdtol->fdl_refcount == 1) { 1819 if (fdp->fd_holdleaderscount > 0 && 1820 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1821 /* 1822 * close() or do_dup() has cleared a reference 1823 * in a shared file descriptor table. 1824 */ 1825 fdp->fd_holdleaderswakeup = 1; 1826 sx_sleep(&fdp->fd_holdleaderscount, 1827 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1828 goto retry; 1829 } 1830 if (fdtol->fdl_holdcount > 0) { 1831 /* 1832 * Ensure that fdtol->fdl_leader remains 1833 * valid in closef(). 1834 */ 1835 fdtol->fdl_wakeup = 1; 1836 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 1837 "fdlhold", 0); 1838 goto retry; 1839 } 1840 } 1841 fdtol->fdl_refcount--; 1842 if (fdtol->fdl_refcount == 0 && 1843 fdtol->fdl_holdcount == 0) { 1844 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1845 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1846 } else 1847 fdtol = NULL; 1848 td->td_proc->p_fdtol = NULL; 1849 FILEDESC_XUNLOCK(fdp); 1850 if (fdtol != NULL) 1851 free(fdtol, M_FILEDESC_TO_LEADER); 1852 } 1853 FILEDESC_XLOCK(fdp); 1854 i = --fdp->fd_refcnt; 1855 FILEDESC_XUNLOCK(fdp); 1856 if (i > 0) 1857 return; 1858 1859 fpp = fdp->fd_ofiles; 1860 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1861 if (*fpp) { 1862 FILEDESC_XLOCK(fdp); 1863 fp = *fpp; 1864 *fpp = NULL; 1865 FILEDESC_XUNLOCK(fdp); 1866 (void) closef(fp, td); 1867 } 1868 } 1869 FILEDESC_XLOCK(fdp); 1870 1871 /* XXX This should happen earlier. */ 1872 mtx_lock(&fdesc_mtx); 1873 td->td_proc->p_fd = NULL; 1874 mtx_unlock(&fdesc_mtx); 1875 1876 if (fdp->fd_nfiles > NDFILE) 1877 free(fdp->fd_ofiles, M_FILEDESC); 1878 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 1879 free(fdp->fd_map, M_FILEDESC); 1880 1881 fdp->fd_nfiles = 0; 1882 1883 cdir = fdp->fd_cdir; 1884 fdp->fd_cdir = NULL; 1885 rdir = fdp->fd_rdir; 1886 fdp->fd_rdir = NULL; 1887 jdir = fdp->fd_jdir; 1888 fdp->fd_jdir = NULL; 1889 FILEDESC_XUNLOCK(fdp); 1890 1891 if (cdir) { 1892 locked = VFS_LOCK_GIANT(cdir->v_mount); 1893 vrele(cdir); 1894 VFS_UNLOCK_GIANT(locked); 1895 } 1896 if (rdir) { 1897 locked = VFS_LOCK_GIANT(rdir->v_mount); 1898 vrele(rdir); 1899 VFS_UNLOCK_GIANT(locked); 1900 } 1901 if (jdir) { 1902 locked = VFS_LOCK_GIANT(jdir->v_mount); 1903 vrele(jdir); 1904 VFS_UNLOCK_GIANT(locked); 1905 } 1906 1907 fddrop(fdp); 1908 } 1909 1910 /* 1911 * For setugid programs, we don't want to people to use that setugidness 1912 * to generate error messages which write to a file which otherwise would 1913 * otherwise be off-limits to the process. We check for filesystems where 1914 * the vnode can change out from under us after execve (like [lin]procfs). 1915 * 1916 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1917 * sufficient. We also don't check for setugidness since we know we are. 1918 */ 1919 static int 1920 is_unsafe(struct file *fp) 1921 { 1922 if (fp->f_type == DTYPE_VNODE) { 1923 struct vnode *vp = fp->f_vnode; 1924 1925 if ((vp->v_vflag & VV_PROCDEP) != 0) 1926 return (1); 1927 } 1928 return (0); 1929 } 1930 1931 /* 1932 * Make this setguid thing safe, if at all possible. 1933 */ 1934 void 1935 setugidsafety(struct thread *td) 1936 { 1937 struct filedesc *fdp; 1938 int i; 1939 1940 /* Certain daemons might not have file descriptors. */ 1941 fdp = td->td_proc->p_fd; 1942 if (fdp == NULL) 1943 return; 1944 1945 /* 1946 * Note: fdp->fd_ofiles may be reallocated out from under us while 1947 * we are blocked in a close. Be careful! 1948 */ 1949 FILEDESC_XLOCK(fdp); 1950 for (i = 0; i <= fdp->fd_lastfile; i++) { 1951 if (i > 2) 1952 break; 1953 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1954 struct file *fp; 1955 1956 knote_fdclose(td, i); 1957 /* 1958 * NULL-out descriptor prior to close to avoid 1959 * a race while close blocks. 1960 */ 1961 fp = fdp->fd_ofiles[i]; 1962 fdp->fd_ofiles[i] = NULL; 1963 fdp->fd_ofileflags[i] = 0; 1964 fdunused(fdp, i); 1965 FILEDESC_XUNLOCK(fdp); 1966 (void) closef(fp, td); 1967 FILEDESC_XLOCK(fdp); 1968 } 1969 } 1970 FILEDESC_XUNLOCK(fdp); 1971 } 1972 1973 /* 1974 * If a specific file object occupies a specific file descriptor, close the 1975 * file descriptor entry and drop a reference on the file object. This is a 1976 * convenience function to handle a subsequent error in a function that calls 1977 * falloc() that handles the race that another thread might have closed the 1978 * file descriptor out from under the thread creating the file object. 1979 */ 1980 void 1981 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 1982 { 1983 1984 FILEDESC_XLOCK(fdp); 1985 if (fdp->fd_ofiles[idx] == fp) { 1986 fdp->fd_ofiles[idx] = NULL; 1987 fdunused(fdp, idx); 1988 FILEDESC_XUNLOCK(fdp); 1989 fdrop(fp, td); 1990 } else 1991 FILEDESC_XUNLOCK(fdp); 1992 } 1993 1994 /* 1995 * Close any files on exec? 1996 */ 1997 void 1998 fdcloseexec(struct thread *td) 1999 { 2000 struct filedesc *fdp; 2001 int i; 2002 2003 /* Certain daemons might not have file descriptors. */ 2004 fdp = td->td_proc->p_fd; 2005 if (fdp == NULL) 2006 return; 2007 2008 FILEDESC_XLOCK(fdp); 2009 2010 /* 2011 * We cannot cache fd_ofiles or fd_ofileflags since operations 2012 * may block and rip them out from under us. 2013 */ 2014 for (i = 0; i <= fdp->fd_lastfile; i++) { 2015 if (fdp->fd_ofiles[i] != NULL && 2016 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE || 2017 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) { 2018 struct file *fp; 2019 2020 knote_fdclose(td, i); 2021 /* 2022 * NULL-out descriptor prior to close to avoid 2023 * a race while close blocks. 2024 */ 2025 fp = fdp->fd_ofiles[i]; 2026 fdp->fd_ofiles[i] = NULL; 2027 fdp->fd_ofileflags[i] = 0; 2028 fdunused(fdp, i); 2029 if (fp->f_type == DTYPE_MQUEUE) 2030 mq_fdclose(td, i, fp); 2031 FILEDESC_XUNLOCK(fdp); 2032 (void) closef(fp, td); 2033 FILEDESC_XLOCK(fdp); 2034 } 2035 } 2036 FILEDESC_XUNLOCK(fdp); 2037 } 2038 2039 /* 2040 * It is unsafe for set[ug]id processes to be started with file 2041 * descriptors 0..2 closed, as these descriptors are given implicit 2042 * significance in the Standard C library. fdcheckstd() will create a 2043 * descriptor referencing /dev/null for each of stdin, stdout, and 2044 * stderr that is not already open. 2045 */ 2046 int 2047 fdcheckstd(struct thread *td) 2048 { 2049 struct filedesc *fdp; 2050 register_t retval, save; 2051 int i, error, devnull; 2052 2053 fdp = td->td_proc->p_fd; 2054 if (fdp == NULL) 2055 return (0); 2056 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2057 devnull = -1; 2058 error = 0; 2059 for (i = 0; i < 3; i++) { 2060 if (fdp->fd_ofiles[i] != NULL) 2061 continue; 2062 if (devnull < 0) { 2063 save = td->td_retval[0]; 2064 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 2065 O_RDWR, 0); 2066 devnull = td->td_retval[0]; 2067 td->td_retval[0] = save; 2068 if (error) 2069 break; 2070 KASSERT(devnull == i, ("oof, we didn't get our fd")); 2071 } else { 2072 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 2073 if (error != 0) 2074 break; 2075 } 2076 } 2077 return (error); 2078 } 2079 2080 /* 2081 * Internal form of close. Decrement reference count on file structure. 2082 * Note: td may be NULL when closing a file that was being passed in a 2083 * message. 2084 * 2085 * XXXRW: Giant is not required for the caller, but often will be held; this 2086 * makes it moderately likely the Giant will be recursed in the VFS case. 2087 */ 2088 int 2089 closef(struct file *fp, struct thread *td) 2090 { 2091 struct vnode *vp; 2092 struct flock lf; 2093 struct filedesc_to_leader *fdtol; 2094 struct filedesc *fdp; 2095 2096 /* 2097 * POSIX record locking dictates that any close releases ALL 2098 * locks owned by this process. This is handled by setting 2099 * a flag in the unlock to free ONLY locks obeying POSIX 2100 * semantics, and not to free BSD-style file locks. 2101 * If the descriptor was in a message, POSIX-style locks 2102 * aren't passed with the descriptor, and the thread pointer 2103 * will be NULL. Callers should be careful only to pass a 2104 * NULL thread pointer when there really is no owning 2105 * context that might have locks, or the locks will be 2106 * leaked. 2107 */ 2108 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2109 int vfslocked; 2110 2111 vp = fp->f_vnode; 2112 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2113 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2114 lf.l_whence = SEEK_SET; 2115 lf.l_start = 0; 2116 lf.l_len = 0; 2117 lf.l_type = F_UNLCK; 2118 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2119 F_UNLCK, &lf, F_POSIX); 2120 } 2121 fdtol = td->td_proc->p_fdtol; 2122 if (fdtol != NULL) { 2123 /* 2124 * Handle special case where file descriptor table is 2125 * shared between multiple process leaders. 2126 */ 2127 fdp = td->td_proc->p_fd; 2128 FILEDESC_XLOCK(fdp); 2129 for (fdtol = fdtol->fdl_next; 2130 fdtol != td->td_proc->p_fdtol; 2131 fdtol = fdtol->fdl_next) { 2132 if ((fdtol->fdl_leader->p_flag & 2133 P_ADVLOCK) == 0) 2134 continue; 2135 fdtol->fdl_holdcount++; 2136 FILEDESC_XUNLOCK(fdp); 2137 lf.l_whence = SEEK_SET; 2138 lf.l_start = 0; 2139 lf.l_len = 0; 2140 lf.l_type = F_UNLCK; 2141 vp = fp->f_vnode; 2142 (void) VOP_ADVLOCK(vp, 2143 (caddr_t)fdtol->fdl_leader, 2144 F_UNLCK, &lf, F_POSIX); 2145 FILEDESC_XLOCK(fdp); 2146 fdtol->fdl_holdcount--; 2147 if (fdtol->fdl_holdcount == 0 && 2148 fdtol->fdl_wakeup != 0) { 2149 fdtol->fdl_wakeup = 0; 2150 wakeup(fdtol); 2151 } 2152 } 2153 FILEDESC_XUNLOCK(fdp); 2154 } 2155 VFS_UNLOCK_GIANT(vfslocked); 2156 } 2157 return (fdrop(fp, td)); 2158 } 2159 2160 /* 2161 * Initialize the file pointer with the specified properties. 2162 * 2163 * The ops are set with release semantics to be certain that the flags, type, 2164 * and data are visible when ops is. This is to prevent ops methods from being 2165 * called with bad data. 2166 */ 2167 void 2168 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2169 { 2170 fp->f_data = data; 2171 fp->f_flag = flag; 2172 fp->f_type = type; 2173 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2174 } 2175 2176 struct file * 2177 fget_unlocked(struct filedesc *fdp, int fd) 2178 { 2179 struct file *fp; 2180 u_int count; 2181 2182 if (fd < 0 || fd >= fdp->fd_nfiles) 2183 return (NULL); 2184 /* 2185 * Fetch the descriptor locklessly. We avoid fdrop() races by 2186 * never raising a refcount above 0. To accomplish this we have 2187 * to use a cmpset loop rather than an atomic_add. The descriptor 2188 * must be re-verified once we acquire a reference to be certain 2189 * that the identity is still correct and we did not lose a race 2190 * due to preemption. 2191 */ 2192 for (;;) { 2193 fp = fdp->fd_ofiles[fd]; 2194 if (fp == NULL) 2195 break; 2196 count = fp->f_count; 2197 if (count == 0) 2198 continue; 2199 /* 2200 * Use an acquire barrier to prevent caching of fd_ofiles 2201 * so it is refreshed for verification. 2202 */ 2203 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1) 2204 continue; 2205 if (fp == fdp->fd_ofiles[fd]) 2206 break; 2207 fdrop(fp, curthread); 2208 } 2209 2210 return (fp); 2211 } 2212 2213 /* 2214 * Extract the file pointer associated with the specified descriptor for the 2215 * current user process. 2216 * 2217 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2218 * returned. 2219 * 2220 * If an error occured the non-zero error is returned and *fpp is set to 2221 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2222 * responsible for fdrop(). 2223 */ 2224 static __inline int 2225 _fget(struct thread *td, int fd, struct file **fpp, int flags) 2226 { 2227 struct filedesc *fdp; 2228 struct file *fp; 2229 2230 *fpp = NULL; 2231 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2232 return (EBADF); 2233 if ((fp = fget_unlocked(fdp, fd)) == NULL) 2234 return (EBADF); 2235 if (fp->f_ops == &badfileops) { 2236 fdrop(fp, td); 2237 return (EBADF); 2238 } 2239 /* 2240 * FREAD and FWRITE failure return EBADF as per POSIX. 2241 * 2242 * Only one flag, or 0, may be specified. 2243 */ 2244 if ((flags == FREAD && (fp->f_flag & FREAD) == 0) || 2245 (flags == FWRITE && (fp->f_flag & FWRITE) == 0)) { 2246 fdrop(fp, td); 2247 return (EBADF); 2248 } 2249 *fpp = fp; 2250 return (0); 2251 } 2252 2253 int 2254 fget(struct thread *td, int fd, struct file **fpp) 2255 { 2256 2257 return(_fget(td, fd, fpp, 0)); 2258 } 2259 2260 int 2261 fget_read(struct thread *td, int fd, struct file **fpp) 2262 { 2263 2264 return(_fget(td, fd, fpp, FREAD)); 2265 } 2266 2267 int 2268 fget_write(struct thread *td, int fd, struct file **fpp) 2269 { 2270 2271 return(_fget(td, fd, fpp, FWRITE)); 2272 } 2273 2274 /* 2275 * Like fget() but loads the underlying vnode, or returns an error if the 2276 * descriptor does not represent a vnode. Note that pipes use vnodes but 2277 * never have VM objects. The returned vnode will be vref()'d. 2278 * 2279 * XXX: what about the unused flags ? 2280 */ 2281 static __inline int 2282 _fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags) 2283 { 2284 struct file *fp; 2285 int error; 2286 2287 *vpp = NULL; 2288 if ((error = _fget(td, fd, &fp, flags)) != 0) 2289 return (error); 2290 if (fp->f_vnode == NULL) { 2291 error = EINVAL; 2292 } else { 2293 *vpp = fp->f_vnode; 2294 vref(*vpp); 2295 } 2296 fdrop(fp, td); 2297 2298 return (error); 2299 } 2300 2301 int 2302 fgetvp(struct thread *td, int fd, struct vnode **vpp) 2303 { 2304 2305 return (_fgetvp(td, fd, vpp, 0)); 2306 } 2307 2308 int 2309 fgetvp_read(struct thread *td, int fd, struct vnode **vpp) 2310 { 2311 2312 return (_fgetvp(td, fd, vpp, FREAD)); 2313 } 2314 2315 #ifdef notyet 2316 int 2317 fgetvp_write(struct thread *td, int fd, struct vnode **vpp) 2318 { 2319 2320 return (_fgetvp(td, fd, vpp, FWRITE)); 2321 } 2322 #endif 2323 2324 /* 2325 * Like fget() but loads the underlying socket, or returns an error if the 2326 * descriptor does not represent a socket. 2327 * 2328 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2329 * in the future. 2330 * 2331 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2332 * on their file descriptor reference to prevent the socket from being free'd 2333 * during use. 2334 */ 2335 int 2336 fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp) 2337 { 2338 struct file *fp; 2339 int error; 2340 2341 *spp = NULL; 2342 if (fflagp != NULL) 2343 *fflagp = 0; 2344 if ((error = _fget(td, fd, &fp, 0)) != 0) 2345 return (error); 2346 if (fp->f_type != DTYPE_SOCKET) { 2347 error = ENOTSOCK; 2348 } else { 2349 *spp = fp->f_data; 2350 if (fflagp) 2351 *fflagp = fp->f_flag; 2352 SOCK_LOCK(*spp); 2353 soref(*spp); 2354 SOCK_UNLOCK(*spp); 2355 } 2356 fdrop(fp, td); 2357 2358 return (error); 2359 } 2360 2361 /* 2362 * Drop the reference count on the socket and XXX release the SX lock in the 2363 * future. The last reference closes the socket. 2364 * 2365 * Note: fputsock() is deprecated, see comment for fgetsock(). 2366 */ 2367 void 2368 fputsock(struct socket *so) 2369 { 2370 2371 ACCEPT_LOCK(); 2372 SOCK_LOCK(so); 2373 CURVNET_SET(so->so_vnet); 2374 sorele(so); 2375 CURVNET_RESTORE(); 2376 } 2377 2378 /* 2379 * Handle the last reference to a file being closed. 2380 */ 2381 int 2382 _fdrop(struct file *fp, struct thread *td) 2383 { 2384 int error; 2385 2386 error = 0; 2387 if (fp->f_count != 0) 2388 panic("fdrop: count %d", fp->f_count); 2389 if (fp->f_ops != &badfileops) 2390 error = fo_close(fp, td); 2391 /* 2392 * The f_cdevpriv cannot be assigned non-NULL value while we 2393 * are destroying the file. 2394 */ 2395 if (fp->f_cdevpriv != NULL) 2396 devfs_fpdrop(fp); 2397 atomic_subtract_int(&openfiles, 1); 2398 crfree(fp->f_cred); 2399 uma_zfree(file_zone, fp); 2400 2401 return (error); 2402 } 2403 2404 /* 2405 * Apply an advisory lock on a file descriptor. 2406 * 2407 * Just attempt to get a record lock of the requested type on the entire file 2408 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2409 */ 2410 #ifndef _SYS_SYSPROTO_H_ 2411 struct flock_args { 2412 int fd; 2413 int how; 2414 }; 2415 #endif 2416 /* ARGSUSED */ 2417 int 2418 flock(struct thread *td, struct flock_args *uap) 2419 { 2420 struct file *fp; 2421 struct vnode *vp; 2422 struct flock lf; 2423 int vfslocked; 2424 int error; 2425 2426 if ((error = fget(td, uap->fd, &fp)) != 0) 2427 return (error); 2428 if (fp->f_type != DTYPE_VNODE) { 2429 fdrop(fp, td); 2430 return (EOPNOTSUPP); 2431 } 2432 2433 vp = fp->f_vnode; 2434 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2435 lf.l_whence = SEEK_SET; 2436 lf.l_start = 0; 2437 lf.l_len = 0; 2438 if (uap->how & LOCK_UN) { 2439 lf.l_type = F_UNLCK; 2440 atomic_clear_int(&fp->f_flag, FHASLOCK); 2441 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2442 goto done2; 2443 } 2444 if (uap->how & LOCK_EX) 2445 lf.l_type = F_WRLCK; 2446 else if (uap->how & LOCK_SH) 2447 lf.l_type = F_RDLCK; 2448 else { 2449 error = EBADF; 2450 goto done2; 2451 } 2452 atomic_set_int(&fp->f_flag, FHASLOCK); 2453 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2454 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2455 done2: 2456 fdrop(fp, td); 2457 VFS_UNLOCK_GIANT(vfslocked); 2458 return (error); 2459 } 2460 /* 2461 * Duplicate the specified descriptor to a free descriptor. 2462 */ 2463 int 2464 dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error) 2465 { 2466 struct file *wfp; 2467 struct file *fp; 2468 2469 /* 2470 * If the to-be-dup'd fd number is greater than the allowed number 2471 * of file descriptors, or the fd to be dup'd has already been 2472 * closed, then reject. 2473 */ 2474 FILEDESC_XLOCK(fdp); 2475 if (dfd < 0 || dfd >= fdp->fd_nfiles || 2476 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 2477 FILEDESC_XUNLOCK(fdp); 2478 return (EBADF); 2479 } 2480 2481 /* 2482 * There are two cases of interest here. 2483 * 2484 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2485 * 2486 * For ENXIO steal away the file structure from (dfd) and store it in 2487 * (indx). (dfd) is effectively closed by this operation. 2488 * 2489 * Any other error code is just returned. 2490 */ 2491 switch (error) { 2492 case ENODEV: 2493 /* 2494 * Check that the mode the file is being opened for is a 2495 * subset of the mode of the existing descriptor. 2496 */ 2497 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2498 FILEDESC_XUNLOCK(fdp); 2499 return (EACCES); 2500 } 2501 fp = fdp->fd_ofiles[indx]; 2502 fdp->fd_ofiles[indx] = wfp; 2503 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2504 if (fp == NULL) 2505 fdused(fdp, indx); 2506 fhold(wfp); 2507 FILEDESC_XUNLOCK(fdp); 2508 if (fp != NULL) 2509 /* 2510 * We now own the reference to fp that the ofiles[] 2511 * array used to own. Release it. 2512 */ 2513 fdrop(fp, td); 2514 return (0); 2515 2516 case ENXIO: 2517 /* 2518 * Steal away the file pointer from dfd and stuff it into indx. 2519 */ 2520 fp = fdp->fd_ofiles[indx]; 2521 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 2522 fdp->fd_ofiles[dfd] = NULL; 2523 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2524 fdp->fd_ofileflags[dfd] = 0; 2525 fdunused(fdp, dfd); 2526 if (fp == NULL) 2527 fdused(fdp, indx); 2528 FILEDESC_XUNLOCK(fdp); 2529 2530 /* 2531 * We now own the reference to fp that the ofiles[] array 2532 * used to own. Release it. 2533 */ 2534 if (fp != NULL) 2535 fdrop(fp, td); 2536 return (0); 2537 2538 default: 2539 FILEDESC_XUNLOCK(fdp); 2540 return (error); 2541 } 2542 /* NOTREACHED */ 2543 } 2544 2545 /* 2546 * Scan all active processes and prisons to see if any of them have a current 2547 * or root directory of `olddp'. If so, replace them with the new mount point. 2548 */ 2549 void 2550 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2551 { 2552 struct filedesc *fdp; 2553 struct prison *pr; 2554 struct proc *p; 2555 int nrele; 2556 2557 if (vrefcnt(olddp) == 1) 2558 return; 2559 nrele = 0; 2560 sx_slock(&allproc_lock); 2561 FOREACH_PROC_IN_SYSTEM(p) { 2562 fdp = fdhold(p); 2563 if (fdp == NULL) 2564 continue; 2565 FILEDESC_XLOCK(fdp); 2566 if (fdp->fd_cdir == olddp) { 2567 vref(newdp); 2568 fdp->fd_cdir = newdp; 2569 nrele++; 2570 } 2571 if (fdp->fd_rdir == olddp) { 2572 vref(newdp); 2573 fdp->fd_rdir = newdp; 2574 nrele++; 2575 } 2576 if (fdp->fd_jdir == olddp) { 2577 vref(newdp); 2578 fdp->fd_jdir = newdp; 2579 nrele++; 2580 } 2581 FILEDESC_XUNLOCK(fdp); 2582 fddrop(fdp); 2583 } 2584 sx_sunlock(&allproc_lock); 2585 if (rootvnode == olddp) { 2586 vref(newdp); 2587 rootvnode = newdp; 2588 nrele++; 2589 } 2590 mtx_lock(&prison0.pr_mtx); 2591 if (prison0.pr_root == olddp) { 2592 vref(newdp); 2593 prison0.pr_root = newdp; 2594 nrele++; 2595 } 2596 mtx_unlock(&prison0.pr_mtx); 2597 sx_slock(&allprison_lock); 2598 TAILQ_FOREACH(pr, &allprison, pr_list) { 2599 mtx_lock(&pr->pr_mtx); 2600 if (pr->pr_root == olddp) { 2601 vref(newdp); 2602 pr->pr_root = newdp; 2603 nrele++; 2604 } 2605 mtx_unlock(&pr->pr_mtx); 2606 } 2607 sx_sunlock(&allprison_lock); 2608 while (nrele--) 2609 vrele(olddp); 2610 } 2611 2612 struct filedesc_to_leader * 2613 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2614 { 2615 struct filedesc_to_leader *fdtol; 2616 2617 fdtol = malloc(sizeof(struct filedesc_to_leader), 2618 M_FILEDESC_TO_LEADER, 2619 M_WAITOK); 2620 fdtol->fdl_refcount = 1; 2621 fdtol->fdl_holdcount = 0; 2622 fdtol->fdl_wakeup = 0; 2623 fdtol->fdl_leader = leader; 2624 if (old != NULL) { 2625 FILEDESC_XLOCK(fdp); 2626 fdtol->fdl_next = old->fdl_next; 2627 fdtol->fdl_prev = old; 2628 old->fdl_next = fdtol; 2629 fdtol->fdl_next->fdl_prev = fdtol; 2630 FILEDESC_XUNLOCK(fdp); 2631 } else { 2632 fdtol->fdl_next = fdtol; 2633 fdtol->fdl_prev = fdtol; 2634 } 2635 return (fdtol); 2636 } 2637 2638 /* 2639 * Get file structures globally. 2640 */ 2641 static int 2642 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2643 { 2644 struct xfile xf; 2645 struct filedesc *fdp; 2646 struct file *fp; 2647 struct proc *p; 2648 int error, n; 2649 2650 error = sysctl_wire_old_buffer(req, 0); 2651 if (error != 0) 2652 return (error); 2653 if (req->oldptr == NULL) { 2654 n = 0; 2655 sx_slock(&allproc_lock); 2656 FOREACH_PROC_IN_SYSTEM(p) { 2657 if (p->p_state == PRS_NEW) 2658 continue; 2659 fdp = fdhold(p); 2660 if (fdp == NULL) 2661 continue; 2662 /* overestimates sparse tables. */ 2663 if (fdp->fd_lastfile > 0) 2664 n += fdp->fd_lastfile; 2665 fddrop(fdp); 2666 } 2667 sx_sunlock(&allproc_lock); 2668 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2669 } 2670 error = 0; 2671 bzero(&xf, sizeof(xf)); 2672 xf.xf_size = sizeof(xf); 2673 sx_slock(&allproc_lock); 2674 FOREACH_PROC_IN_SYSTEM(p) { 2675 PROC_LOCK(p); 2676 if (p->p_state == PRS_NEW) { 2677 PROC_UNLOCK(p); 2678 continue; 2679 } 2680 if (p_cansee(req->td, p) != 0) { 2681 PROC_UNLOCK(p); 2682 continue; 2683 } 2684 xf.xf_pid = p->p_pid; 2685 xf.xf_uid = p->p_ucred->cr_uid; 2686 PROC_UNLOCK(p); 2687 fdp = fdhold(p); 2688 if (fdp == NULL) 2689 continue; 2690 FILEDESC_SLOCK(fdp); 2691 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) { 2692 if ((fp = fdp->fd_ofiles[n]) == NULL) 2693 continue; 2694 xf.xf_fd = n; 2695 xf.xf_file = fp; 2696 xf.xf_data = fp->f_data; 2697 xf.xf_vnode = fp->f_vnode; 2698 xf.xf_type = fp->f_type; 2699 xf.xf_count = fp->f_count; 2700 xf.xf_msgcount = 0; 2701 xf.xf_offset = fp->f_offset; 2702 xf.xf_flag = fp->f_flag; 2703 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2704 if (error) 2705 break; 2706 } 2707 FILEDESC_SUNLOCK(fdp); 2708 fddrop(fdp); 2709 if (error) 2710 break; 2711 } 2712 sx_sunlock(&allproc_lock); 2713 return (error); 2714 } 2715 2716 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2717 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2718 2719 #ifdef KINFO_OFILE_SIZE 2720 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 2721 #endif 2722 2723 #ifdef COMPAT_FREEBSD7 2724 static int 2725 export_vnode_for_osysctl(struct vnode *vp, int type, 2726 struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req) 2727 { 2728 int error; 2729 char *fullpath, *freepath; 2730 int vfslocked; 2731 2732 bzero(kif, sizeof(*kif)); 2733 kif->kf_structsize = sizeof(*kif); 2734 2735 vref(vp); 2736 kif->kf_fd = type; 2737 kif->kf_type = KF_TYPE_VNODE; 2738 /* This function only handles directories. */ 2739 if (vp->v_type != VDIR) { 2740 vrele(vp); 2741 return (ENOTDIR); 2742 } 2743 kif->kf_vnode_type = KF_VTYPE_VDIR; 2744 2745 /* 2746 * This is not a true file descriptor, so we set a bogus refcount 2747 * and offset to indicate these fields should be ignored. 2748 */ 2749 kif->kf_ref_count = -1; 2750 kif->kf_offset = -1; 2751 2752 freepath = NULL; 2753 fullpath = "-"; 2754 FILEDESC_SUNLOCK(fdp); 2755 vn_fullpath(curthread, vp, &fullpath, &freepath); 2756 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2757 vrele(vp); 2758 VFS_UNLOCK_GIANT(vfslocked); 2759 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2760 if (freepath != NULL) 2761 free(freepath, M_TEMP); 2762 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2763 FILEDESC_SLOCK(fdp); 2764 return (error); 2765 } 2766 2767 /* 2768 * Get per-process file descriptors for use by procstat(1), et al. 2769 */ 2770 static int 2771 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 2772 { 2773 char *fullpath, *freepath; 2774 struct kinfo_ofile *kif; 2775 struct filedesc *fdp; 2776 int error, i, *name; 2777 struct socket *so; 2778 struct vnode *vp; 2779 struct file *fp; 2780 struct proc *p; 2781 struct tty *tp; 2782 int vfslocked; 2783 2784 name = (int *)arg1; 2785 if ((p = pfind((pid_t)name[0])) == NULL) 2786 return (ESRCH); 2787 if ((error = p_candebug(curthread, p))) { 2788 PROC_UNLOCK(p); 2789 return (error); 2790 } 2791 fdp = fdhold(p); 2792 PROC_UNLOCK(p); 2793 if (fdp == NULL) 2794 return (ENOENT); 2795 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 2796 FILEDESC_SLOCK(fdp); 2797 if (fdp->fd_cdir != NULL) 2798 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 2799 fdp, req); 2800 if (fdp->fd_rdir != NULL) 2801 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 2802 fdp, req); 2803 if (fdp->fd_jdir != NULL) 2804 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 2805 fdp, req); 2806 for (i = 0; i < fdp->fd_nfiles; i++) { 2807 if ((fp = fdp->fd_ofiles[i]) == NULL) 2808 continue; 2809 bzero(kif, sizeof(*kif)); 2810 kif->kf_structsize = sizeof(*kif); 2811 vp = NULL; 2812 so = NULL; 2813 tp = NULL; 2814 kif->kf_fd = i; 2815 switch (fp->f_type) { 2816 case DTYPE_VNODE: 2817 kif->kf_type = KF_TYPE_VNODE; 2818 vp = fp->f_vnode; 2819 break; 2820 2821 case DTYPE_SOCKET: 2822 kif->kf_type = KF_TYPE_SOCKET; 2823 so = fp->f_data; 2824 break; 2825 2826 case DTYPE_PIPE: 2827 kif->kf_type = KF_TYPE_PIPE; 2828 break; 2829 2830 case DTYPE_FIFO: 2831 kif->kf_type = KF_TYPE_FIFO; 2832 vp = fp->f_vnode; 2833 break; 2834 2835 case DTYPE_KQUEUE: 2836 kif->kf_type = KF_TYPE_KQUEUE; 2837 break; 2838 2839 case DTYPE_CRYPTO: 2840 kif->kf_type = KF_TYPE_CRYPTO; 2841 break; 2842 2843 case DTYPE_MQUEUE: 2844 kif->kf_type = KF_TYPE_MQUEUE; 2845 break; 2846 2847 case DTYPE_SHM: 2848 kif->kf_type = KF_TYPE_SHM; 2849 break; 2850 2851 case DTYPE_SEM: 2852 kif->kf_type = KF_TYPE_SEM; 2853 break; 2854 2855 case DTYPE_PTS: 2856 kif->kf_type = KF_TYPE_PTS; 2857 tp = fp->f_data; 2858 break; 2859 2860 default: 2861 kif->kf_type = KF_TYPE_UNKNOWN; 2862 break; 2863 } 2864 kif->kf_ref_count = fp->f_count; 2865 if (fp->f_flag & FREAD) 2866 kif->kf_flags |= KF_FLAG_READ; 2867 if (fp->f_flag & FWRITE) 2868 kif->kf_flags |= KF_FLAG_WRITE; 2869 if (fp->f_flag & FAPPEND) 2870 kif->kf_flags |= KF_FLAG_APPEND; 2871 if (fp->f_flag & FASYNC) 2872 kif->kf_flags |= KF_FLAG_ASYNC; 2873 if (fp->f_flag & FFSYNC) 2874 kif->kf_flags |= KF_FLAG_FSYNC; 2875 if (fp->f_flag & FNONBLOCK) 2876 kif->kf_flags |= KF_FLAG_NONBLOCK; 2877 if (fp->f_flag & O_DIRECT) 2878 kif->kf_flags |= KF_FLAG_DIRECT; 2879 if (fp->f_flag & FHASLOCK) 2880 kif->kf_flags |= KF_FLAG_HASLOCK; 2881 kif->kf_offset = fp->f_offset; 2882 if (vp != NULL) { 2883 vref(vp); 2884 switch (vp->v_type) { 2885 case VNON: 2886 kif->kf_vnode_type = KF_VTYPE_VNON; 2887 break; 2888 case VREG: 2889 kif->kf_vnode_type = KF_VTYPE_VREG; 2890 break; 2891 case VDIR: 2892 kif->kf_vnode_type = KF_VTYPE_VDIR; 2893 break; 2894 case VBLK: 2895 kif->kf_vnode_type = KF_VTYPE_VBLK; 2896 break; 2897 case VCHR: 2898 kif->kf_vnode_type = KF_VTYPE_VCHR; 2899 break; 2900 case VLNK: 2901 kif->kf_vnode_type = KF_VTYPE_VLNK; 2902 break; 2903 case VSOCK: 2904 kif->kf_vnode_type = KF_VTYPE_VSOCK; 2905 break; 2906 case VFIFO: 2907 kif->kf_vnode_type = KF_VTYPE_VFIFO; 2908 break; 2909 case VBAD: 2910 kif->kf_vnode_type = KF_VTYPE_VBAD; 2911 break; 2912 default: 2913 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 2914 break; 2915 } 2916 /* 2917 * It is OK to drop the filedesc lock here as we will 2918 * re-validate and re-evaluate its properties when 2919 * the loop continues. 2920 */ 2921 freepath = NULL; 2922 fullpath = "-"; 2923 FILEDESC_SUNLOCK(fdp); 2924 vn_fullpath(curthread, vp, &fullpath, &freepath); 2925 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2926 vrele(vp); 2927 VFS_UNLOCK_GIANT(vfslocked); 2928 strlcpy(kif->kf_path, fullpath, 2929 sizeof(kif->kf_path)); 2930 if (freepath != NULL) 2931 free(freepath, M_TEMP); 2932 FILEDESC_SLOCK(fdp); 2933 } 2934 if (so != NULL) { 2935 struct sockaddr *sa; 2936 2937 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 2938 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 2939 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 2940 free(sa, M_SONAME); 2941 } 2942 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 2943 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 2944 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 2945 free(sa, M_SONAME); 2946 } 2947 kif->kf_sock_domain = 2948 so->so_proto->pr_domain->dom_family; 2949 kif->kf_sock_type = so->so_type; 2950 kif->kf_sock_protocol = so->so_proto->pr_protocol; 2951 } 2952 if (tp != NULL) { 2953 strlcpy(kif->kf_path, tty_devname(tp), 2954 sizeof(kif->kf_path)); 2955 } 2956 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2957 if (error) 2958 break; 2959 } 2960 FILEDESC_SUNLOCK(fdp); 2961 fddrop(fdp); 2962 free(kif, M_TEMP); 2963 return (0); 2964 } 2965 2966 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD, 2967 sysctl_kern_proc_ofiledesc, "Process ofiledesc entries"); 2968 #endif /* COMPAT_FREEBSD7 */ 2969 2970 #ifdef KINFO_FILE_SIZE 2971 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 2972 #endif 2973 2974 static int 2975 export_vnode_for_sysctl(struct vnode *vp, int type, 2976 struct kinfo_file *kif, struct filedesc *fdp, struct sysctl_req *req) 2977 { 2978 int error; 2979 char *fullpath, *freepath; 2980 int vfslocked; 2981 2982 bzero(kif, sizeof(*kif)); 2983 2984 vref(vp); 2985 kif->kf_fd = type; 2986 kif->kf_type = KF_TYPE_VNODE; 2987 /* This function only handles directories. */ 2988 if (vp->v_type != VDIR) { 2989 vrele(vp); 2990 return (ENOTDIR); 2991 } 2992 kif->kf_vnode_type = KF_VTYPE_VDIR; 2993 2994 /* 2995 * This is not a true file descriptor, so we set a bogus refcount 2996 * and offset to indicate these fields should be ignored. 2997 */ 2998 kif->kf_ref_count = -1; 2999 kif->kf_offset = -1; 3000 3001 freepath = NULL; 3002 fullpath = "-"; 3003 FILEDESC_SUNLOCK(fdp); 3004 vn_fullpath(curthread, vp, &fullpath, &freepath); 3005 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 3006 vrele(vp); 3007 VFS_UNLOCK_GIANT(vfslocked); 3008 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 3009 if (freepath != NULL) 3010 free(freepath, M_TEMP); 3011 /* Pack record size down */ 3012 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3013 strlen(kif->kf_path) + 1; 3014 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3015 error = SYSCTL_OUT(req, kif, kif->kf_structsize); 3016 FILEDESC_SLOCK(fdp); 3017 return (error); 3018 } 3019 3020 /* 3021 * Get per-process file descriptors for use by procstat(1), et al. 3022 */ 3023 static int 3024 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3025 { 3026 char *fullpath, *freepath; 3027 struct kinfo_file *kif; 3028 struct filedesc *fdp; 3029 int error, i, *name; 3030 struct socket *so; 3031 struct vnode *vp; 3032 struct file *fp; 3033 struct proc *p; 3034 struct tty *tp; 3035 int vfslocked; 3036 size_t oldidx; 3037 3038 name = (int *)arg1; 3039 if ((p = pfind((pid_t)name[0])) == NULL) 3040 return (ESRCH); 3041 if ((error = p_candebug(curthread, p))) { 3042 PROC_UNLOCK(p); 3043 return (error); 3044 } 3045 fdp = fdhold(p); 3046 PROC_UNLOCK(p); 3047 if (fdp == NULL) 3048 return (ENOENT); 3049 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3050 FILEDESC_SLOCK(fdp); 3051 if (fdp->fd_cdir != NULL) 3052 export_vnode_for_sysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3053 fdp, req); 3054 if (fdp->fd_rdir != NULL) 3055 export_vnode_for_sysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3056 fdp, req); 3057 if (fdp->fd_jdir != NULL) 3058 export_vnode_for_sysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3059 fdp, req); 3060 for (i = 0; i < fdp->fd_nfiles; i++) { 3061 if ((fp = fdp->fd_ofiles[i]) == NULL) 3062 continue; 3063 bzero(kif, sizeof(*kif)); 3064 vp = NULL; 3065 so = NULL; 3066 tp = NULL; 3067 kif->kf_fd = i; 3068 switch (fp->f_type) { 3069 case DTYPE_VNODE: 3070 kif->kf_type = KF_TYPE_VNODE; 3071 vp = fp->f_vnode; 3072 break; 3073 3074 case DTYPE_SOCKET: 3075 kif->kf_type = KF_TYPE_SOCKET; 3076 so = fp->f_data; 3077 break; 3078 3079 case DTYPE_PIPE: 3080 kif->kf_type = KF_TYPE_PIPE; 3081 break; 3082 3083 case DTYPE_FIFO: 3084 kif->kf_type = KF_TYPE_FIFO; 3085 vp = fp->f_vnode; 3086 break; 3087 3088 case DTYPE_KQUEUE: 3089 kif->kf_type = KF_TYPE_KQUEUE; 3090 break; 3091 3092 case DTYPE_CRYPTO: 3093 kif->kf_type = KF_TYPE_CRYPTO; 3094 break; 3095 3096 case DTYPE_MQUEUE: 3097 kif->kf_type = KF_TYPE_MQUEUE; 3098 break; 3099 3100 case DTYPE_SHM: 3101 kif->kf_type = KF_TYPE_SHM; 3102 break; 3103 3104 case DTYPE_SEM: 3105 kif->kf_type = KF_TYPE_SEM; 3106 break; 3107 3108 case DTYPE_PTS: 3109 kif->kf_type = KF_TYPE_PTS; 3110 tp = fp->f_data; 3111 break; 3112 3113 default: 3114 kif->kf_type = KF_TYPE_UNKNOWN; 3115 break; 3116 } 3117 kif->kf_ref_count = fp->f_count; 3118 if (fp->f_flag & FREAD) 3119 kif->kf_flags |= KF_FLAG_READ; 3120 if (fp->f_flag & FWRITE) 3121 kif->kf_flags |= KF_FLAG_WRITE; 3122 if (fp->f_flag & FAPPEND) 3123 kif->kf_flags |= KF_FLAG_APPEND; 3124 if (fp->f_flag & FASYNC) 3125 kif->kf_flags |= KF_FLAG_ASYNC; 3126 if (fp->f_flag & FFSYNC) 3127 kif->kf_flags |= KF_FLAG_FSYNC; 3128 if (fp->f_flag & FNONBLOCK) 3129 kif->kf_flags |= KF_FLAG_NONBLOCK; 3130 if (fp->f_flag & O_DIRECT) 3131 kif->kf_flags |= KF_FLAG_DIRECT; 3132 if (fp->f_flag & FHASLOCK) 3133 kif->kf_flags |= KF_FLAG_HASLOCK; 3134 kif->kf_offset = fp->f_offset; 3135 if (vp != NULL) { 3136 vref(vp); 3137 switch (vp->v_type) { 3138 case VNON: 3139 kif->kf_vnode_type = KF_VTYPE_VNON; 3140 break; 3141 case VREG: 3142 kif->kf_vnode_type = KF_VTYPE_VREG; 3143 break; 3144 case VDIR: 3145 kif->kf_vnode_type = KF_VTYPE_VDIR; 3146 break; 3147 case VBLK: 3148 kif->kf_vnode_type = KF_VTYPE_VBLK; 3149 break; 3150 case VCHR: 3151 kif->kf_vnode_type = KF_VTYPE_VCHR; 3152 break; 3153 case VLNK: 3154 kif->kf_vnode_type = KF_VTYPE_VLNK; 3155 break; 3156 case VSOCK: 3157 kif->kf_vnode_type = KF_VTYPE_VSOCK; 3158 break; 3159 case VFIFO: 3160 kif->kf_vnode_type = KF_VTYPE_VFIFO; 3161 break; 3162 case VBAD: 3163 kif->kf_vnode_type = KF_VTYPE_VBAD; 3164 break; 3165 default: 3166 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 3167 break; 3168 } 3169 /* 3170 * It is OK to drop the filedesc lock here as we will 3171 * re-validate and re-evaluate its properties when 3172 * the loop continues. 3173 */ 3174 freepath = NULL; 3175 fullpath = "-"; 3176 FILEDESC_SUNLOCK(fdp); 3177 vn_fullpath(curthread, vp, &fullpath, &freepath); 3178 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 3179 vrele(vp); 3180 VFS_UNLOCK_GIANT(vfslocked); 3181 strlcpy(kif->kf_path, fullpath, 3182 sizeof(kif->kf_path)); 3183 if (freepath != NULL) 3184 free(freepath, M_TEMP); 3185 FILEDESC_SLOCK(fdp); 3186 } 3187 if (so != NULL) { 3188 struct sockaddr *sa; 3189 3190 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 3191 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 3192 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 3193 free(sa, M_SONAME); 3194 } 3195 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 3196 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 3197 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 3198 free(sa, M_SONAME); 3199 } 3200 kif->kf_sock_domain = 3201 so->so_proto->pr_domain->dom_family; 3202 kif->kf_sock_type = so->so_type; 3203 kif->kf_sock_protocol = so->so_proto->pr_protocol; 3204 } 3205 if (tp != NULL) { 3206 strlcpy(kif->kf_path, tty_devname(tp), 3207 sizeof(kif->kf_path)); 3208 } 3209 /* Pack record size down */ 3210 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3211 strlen(kif->kf_path) + 1; 3212 kif->kf_structsize = roundup(kif->kf_structsize, 3213 sizeof(uint64_t)); 3214 oldidx = req->oldidx; 3215 error = SYSCTL_OUT(req, kif, kif->kf_structsize); 3216 if (error) { 3217 if (error == ENOMEM) { 3218 /* 3219 * The hack to keep the ABI of sysctl 3220 * kern.proc.filedesc intact, but not 3221 * to account a partially copied 3222 * kinfo_file into the oldidx. 3223 */ 3224 req->oldidx = oldidx; 3225 error = 0; 3226 } 3227 break; 3228 } 3229 } 3230 FILEDESC_SUNLOCK(fdp); 3231 fddrop(fdp); 3232 free(kif, M_TEMP); 3233 return (error); 3234 } 3235 3236 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD, 3237 sysctl_kern_proc_filedesc, "Process filedesc entries"); 3238 3239 #ifdef DDB 3240 /* 3241 * For the purposes of debugging, generate a human-readable string for the 3242 * file type. 3243 */ 3244 static const char * 3245 file_type_to_name(short type) 3246 { 3247 3248 switch (type) { 3249 case 0: 3250 return ("zero"); 3251 case DTYPE_VNODE: 3252 return ("vnod"); 3253 case DTYPE_SOCKET: 3254 return ("sock"); 3255 case DTYPE_PIPE: 3256 return ("pipe"); 3257 case DTYPE_FIFO: 3258 return ("fifo"); 3259 case DTYPE_KQUEUE: 3260 return ("kque"); 3261 case DTYPE_CRYPTO: 3262 return ("crpt"); 3263 case DTYPE_MQUEUE: 3264 return ("mque"); 3265 case DTYPE_SHM: 3266 return ("shm"); 3267 case DTYPE_SEM: 3268 return ("ksem"); 3269 default: 3270 return ("unkn"); 3271 } 3272 } 3273 3274 /* 3275 * For the purposes of debugging, identify a process (if any, perhaps one of 3276 * many) that references the passed file in its file descriptor array. Return 3277 * NULL if none. 3278 */ 3279 static struct proc * 3280 file_to_first_proc(struct file *fp) 3281 { 3282 struct filedesc *fdp; 3283 struct proc *p; 3284 int n; 3285 3286 FOREACH_PROC_IN_SYSTEM(p) { 3287 if (p->p_state == PRS_NEW) 3288 continue; 3289 fdp = p->p_fd; 3290 if (fdp == NULL) 3291 continue; 3292 for (n = 0; n < fdp->fd_nfiles; n++) { 3293 if (fp == fdp->fd_ofiles[n]) 3294 return (p); 3295 } 3296 } 3297 return (NULL); 3298 } 3299 3300 static void 3301 db_print_file(struct file *fp, int header) 3302 { 3303 struct proc *p; 3304 3305 if (header) 3306 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3307 "File", "Type", "Data", "Flag", "GCFl", "Count", 3308 "MCount", "Vnode", "FPID", "FCmd"); 3309 p = file_to_first_proc(fp); 3310 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3311 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3312 0, fp->f_count, 0, fp->f_vnode, 3313 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3314 } 3315 3316 DB_SHOW_COMMAND(file, db_show_file) 3317 { 3318 struct file *fp; 3319 3320 if (!have_addr) { 3321 db_printf("usage: show file <addr>\n"); 3322 return; 3323 } 3324 fp = (struct file *)addr; 3325 db_print_file(fp, 1); 3326 } 3327 3328 DB_SHOW_COMMAND(files, db_show_files) 3329 { 3330 struct filedesc *fdp; 3331 struct file *fp; 3332 struct proc *p; 3333 int header; 3334 int n; 3335 3336 header = 1; 3337 FOREACH_PROC_IN_SYSTEM(p) { 3338 if (p->p_state == PRS_NEW) 3339 continue; 3340 if ((fdp = p->p_fd) == NULL) 3341 continue; 3342 for (n = 0; n < fdp->fd_nfiles; ++n) { 3343 if ((fp = fdp->fd_ofiles[n]) == NULL) 3344 continue; 3345 db_print_file(fp, header); 3346 header = 0; 3347 } 3348 } 3349 } 3350 #endif 3351 3352 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3353 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3354 3355 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3356 &maxfiles, 0, "Maximum number of files"); 3357 3358 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3359 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3360 3361 /* ARGSUSED*/ 3362 static void 3363 filelistinit(void *dummy) 3364 { 3365 3366 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3367 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3368 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3369 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3370 } 3371 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3372 3373 /*-------------------------------------------------------------------*/ 3374 3375 static int 3376 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) 3377 { 3378 3379 return (EBADF); 3380 } 3381 3382 static int 3383 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) 3384 { 3385 3386 return (EINVAL); 3387 } 3388 3389 static int 3390 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) 3391 { 3392 3393 return (EBADF); 3394 } 3395 3396 static int 3397 badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) 3398 { 3399 3400 return (0); 3401 } 3402 3403 static int 3404 badfo_kqfilter(struct file *fp, struct knote *kn) 3405 { 3406 3407 return (EBADF); 3408 } 3409 3410 static int 3411 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) 3412 { 3413 3414 return (EBADF); 3415 } 3416 3417 static int 3418 badfo_close(struct file *fp, struct thread *td) 3419 { 3420 3421 return (EBADF); 3422 } 3423 3424 struct fileops badfileops = { 3425 .fo_read = badfo_readwrite, 3426 .fo_write = badfo_readwrite, 3427 .fo_truncate = badfo_truncate, 3428 .fo_ioctl = badfo_ioctl, 3429 .fo_poll = badfo_poll, 3430 .fo_kqfilter = badfo_kqfilter, 3431 .fo_stat = badfo_stat, 3432 .fo_close = badfo_close, 3433 }; 3434 3435 3436 /*-------------------------------------------------------------------*/ 3437 3438 /* 3439 * File Descriptor pseudo-device driver (/dev/fd/). 3440 * 3441 * Opening minor device N dup()s the file (if any) connected to file 3442 * descriptor N belonging to the calling process. Note that this driver 3443 * consists of only the ``open()'' routine, because all subsequent 3444 * references to this file will be direct to the other driver. 3445 * 3446 * XXX: we could give this one a cloning event handler if necessary. 3447 */ 3448 3449 /* ARGSUSED */ 3450 static int 3451 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3452 { 3453 3454 /* 3455 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3456 * the file descriptor being sought for duplication. The error 3457 * return ensures that the vnode for this device will be released 3458 * by vn_open. Open will detect this special error and take the 3459 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3460 * will simply report the error. 3461 */ 3462 td->td_dupfd = dev2unit(dev); 3463 return (ENODEV); 3464 } 3465 3466 static struct cdevsw fildesc_cdevsw = { 3467 .d_version = D_VERSION, 3468 .d_open = fdopen, 3469 .d_name = "FD", 3470 }; 3471 3472 static void 3473 fildesc_drvinit(void *unused) 3474 { 3475 struct cdev *dev; 3476 3477 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3478 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3479 make_dev_alias(dev, "stdin"); 3480 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3481 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3482 make_dev_alias(dev, "stdout"); 3483 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3484 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3485 make_dev_alias(dev, "stderr"); 3486 } 3487 3488 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3489