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: stable/10/sys/kern/kern_descrip.c 321020 2017-07-15 17:25:40Z dchagin $"); 39 40#include "opt_capsicum.h" 41#include "opt_compat.h" 42#include "opt_ddb.h" 43#include "opt_ktrace.h" 44#include "opt_procdesc.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48 49#include <sys/capsicum.h> 50#include <sys/conf.h> 51#include <sys/domain.h> 52#include <sys/fail.h> 53#include <sys/fcntl.h> 54#include <sys/file.h> 55#include <sys/filedesc.h> 56#include <sys/filio.h> 57#include <sys/jail.h> 58#include <sys/kernel.h> 59#include <sys/ksem.h> 60#include <sys/limits.h> 61#include <sys/lock.h> 62#include <sys/malloc.h> 63#include <sys/mman.h> 64#include <sys/mount.h> 65#include <sys/mqueue.h> 66#include <sys/mutex.h> 67#include <sys/namei.h> 68#include <sys/selinfo.h> 69#include <sys/pipe.h> 70#include <sys/priv.h> 71#include <sys/proc.h> 72#include <sys/procdesc.h> 73#include <sys/protosw.h> 74#include <sys/racct.h> 75#include <sys/resourcevar.h> 76#include <sys/sbuf.h> 77#include <sys/signalvar.h> 78#include <sys/socketvar.h> 79#include <sys/stat.h> 80#include <sys/sx.h> 81#include <sys/syscallsubr.h> 82#include <sys/sysctl.h> 83#include <sys/sysproto.h> 84#include <sys/tty.h> 85#include <sys/unistd.h> 86#include <sys/un.h> 87#include <sys/unpcb.h> 88#include <sys/user.h> 89#include <sys/vnode.h> 90#ifdef KTRACE 91#include <sys/ktrace.h> 92#endif 93 94#include <net/vnet.h> 95 96#include <netinet/in.h> 97#include <netinet/in_pcb.h> 98 99#include <security/audit/audit.h> 100 101#include <vm/uma.h> 102#include <vm/vm.h> 103 104#include <ddb/ddb.h> 105 106static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 107static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 108 "file desc to leader structures"); 109static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 110MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 111 112MALLOC_DECLARE(M_FADVISE); 113 114static uma_zone_t file_zone; 115 116void (*ksem_info)(struct ksem *ks, char *path, size_t size, uint32_t *value); 117 118static int closefp(struct filedesc *fdp, int fd, struct file *fp, 119 struct thread *td, int holdleaders); 120static int fd_first_free(struct filedesc *fdp, int low, int size); 121static int fd_last_used(struct filedesc *fdp, int size); 122static void fdgrowtable(struct filedesc *fdp, int nfd); 123static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 124static void fdunused(struct filedesc *fdp, int fd); 125static void fdused(struct filedesc *fdp, int fd); 126static int fill_pipe_info(struct pipe *pi, struct kinfo_file *kif); 127static int fill_procdesc_info(struct procdesc *pdp, 128 struct kinfo_file *kif); 129static int fill_pts_info(struct tty *tp, struct kinfo_file *kif); 130static int fill_sem_info(struct file *fp, struct kinfo_file *kif); 131static int fill_shm_info(struct file *fp, struct kinfo_file *kif); 132static int fill_socket_info(struct socket *so, struct kinfo_file *kif); 133static int fill_vnode_info(struct vnode *vp, struct kinfo_file *kif); 134static int getmaxfd(struct proc *p); 135 136/* 137 * Each process has: 138 * 139 * - An array of open file descriptors (fd_ofiles) 140 * - An array of file flags (fd_ofileflags) 141 * - A bitmap recording which descriptors are in use (fd_map) 142 * 143 * A process starts out with NDFILE descriptors. The value of NDFILE has 144 * been selected based the historical limit of 20 open files, and an 145 * assumption that the majority of processes, especially short-lived 146 * processes like shells, will never need more. 147 * 148 * If this initial allocation is exhausted, a larger descriptor table and 149 * map are allocated dynamically, and the pointers in the process's struct 150 * filedesc are updated to point to those. This is repeated every time 151 * the process runs out of file descriptors (provided it hasn't hit its 152 * resource limit). 153 * 154 * Since threads may hold references to individual descriptor table 155 * entries, the tables are never freed. Instead, they are placed on a 156 * linked list and freed only when the struct filedesc is released. 157 */ 158#define NDFILE 20 159#define NDSLOTSIZE sizeof(NDSLOTTYPE) 160#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 161#define NDSLOT(x) ((x) / NDENTRIES) 162#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 163#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 164 165/* 166 * SLIST entry used to keep track of ofiles which must be reclaimed when 167 * the process exits. 168 */ 169struct freetable { 170 struct filedescent *ft_table; 171 SLIST_ENTRY(freetable) ft_next; 172}; 173 174/* 175 * Initial allocation: a filedesc structure + the head of SLIST used to 176 * keep track of old ofiles + enough space for NDFILE descriptors. 177 */ 178struct filedesc0 { 179 struct filedesc fd_fd; 180 SLIST_HEAD(, freetable) fd_free; 181 struct filedescent fd_dfiles[NDFILE]; 182 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 183}; 184 185/* 186 * Descriptor management. 187 */ 188volatile int openfiles; /* actual number of open files */ 189struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 190void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 191 192/* A mutex to protect the association between a proc and filedesc. */ 193static struct mtx fdesc_mtx; 194 195/* 196 * If low >= size, just return low. Otherwise find the first zero bit in the 197 * given bitmap, starting at low and not exceeding size - 1. Return size if 198 * not found. 199 */ 200static int 201fd_first_free(struct filedesc *fdp, int low, int size) 202{ 203 NDSLOTTYPE *map = fdp->fd_map; 204 NDSLOTTYPE mask; 205 int off, maxoff; 206 207 if (low >= size) 208 return (low); 209 210 off = NDSLOT(low); 211 if (low % NDENTRIES) { 212 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 213 if ((mask &= ~map[off]) != 0UL) 214 return (off * NDENTRIES + ffsl(mask) - 1); 215 ++off; 216 } 217 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 218 if (map[off] != ~0UL) 219 return (off * NDENTRIES + ffsl(~map[off]) - 1); 220 return (size); 221} 222 223/* 224 * Find the highest non-zero bit in the given bitmap, starting at 0 and 225 * not exceeding size - 1. Return -1 if not found. 226 */ 227static int 228fd_last_used(struct filedesc *fdp, int size) 229{ 230 NDSLOTTYPE *map = fdp->fd_map; 231 NDSLOTTYPE mask; 232 int off, minoff; 233 234 off = NDSLOT(size); 235 if (size % NDENTRIES) { 236 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 237 if ((mask &= map[off]) != 0) 238 return (off * NDENTRIES + flsl(mask) - 1); 239 --off; 240 } 241 for (minoff = NDSLOT(0); off >= minoff; --off) 242 if (map[off] != 0) 243 return (off * NDENTRIES + flsl(map[off]) - 1); 244 return (-1); 245} 246 247static int 248fdisused(struct filedesc *fdp, int fd) 249{ 250 251 FILEDESC_LOCK_ASSERT(fdp); 252 253 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 254 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 255 256 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 257} 258 259/* 260 * Mark a file descriptor as used. 261 */ 262static void 263fdused(struct filedesc *fdp, int fd) 264{ 265 266 FILEDESC_XLOCK_ASSERT(fdp); 267 268 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 269 270 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 271 if (fd > fdp->fd_lastfile) 272 fdp->fd_lastfile = fd; 273 if (fd == fdp->fd_freefile) 274 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 275} 276 277/* 278 * Mark a file descriptor as unused. 279 */ 280static void 281fdunused(struct filedesc *fdp, int fd) 282{ 283 284 FILEDESC_XLOCK_ASSERT(fdp); 285 286 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 287 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 288 ("fd=%d is still in use", fd)); 289 290 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 291 if (fd < fdp->fd_freefile) 292 fdp->fd_freefile = fd; 293 if (fd == fdp->fd_lastfile) 294 fdp->fd_lastfile = fd_last_used(fdp, fd); 295} 296 297/* 298 * Free a file descriptor. 299 * 300 * Avoid some work if fdp is about to be destroyed. 301 */ 302static inline void 303_fdfree(struct filedesc *fdp, int fd, int last) 304{ 305 struct filedescent *fde; 306 307 fde = &fdp->fd_ofiles[fd]; 308#ifdef CAPABILITIES 309 if (!last) 310 seq_write_begin(&fde->fde_seq); 311#endif 312 filecaps_free(&fde->fde_caps); 313 if (last) 314 return; 315 bzero(fde, fde_change_size); 316 fdunused(fdp, fd); 317#ifdef CAPABILITIES 318 seq_write_end(&fde->fde_seq); 319#endif 320} 321 322static inline void 323fdfree(struct filedesc *fdp, int fd) 324{ 325 326 _fdfree(fdp, fd, 0); 327} 328 329static inline void 330fdfree_last(struct filedesc *fdp, int fd) 331{ 332 333 _fdfree(fdp, fd, 1); 334} 335 336/* 337 * System calls on descriptors. 338 */ 339#ifndef _SYS_SYSPROTO_H_ 340struct getdtablesize_args { 341 int dummy; 342}; 343#endif 344/* ARGSUSED */ 345int 346sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 347{ 348 struct proc *p = td->td_proc; 349 uint64_t lim; 350 351 PROC_LOCK(p); 352 td->td_retval[0] = 353 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(p); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 return (0); 359} 360 361/* 362 * Duplicate a file descriptor to a particular value. 363 * 364 * Note: keep in mind that a potential race condition exists when closing 365 * descriptors from a shared descriptor table (via rfork). 366 */ 367#ifndef _SYS_SYSPROTO_H_ 368struct dup2_args { 369 u_int from; 370 u_int to; 371}; 372#endif 373/* ARGSUSED */ 374int 375sys_dup2(struct thread *td, struct dup2_args *uap) 376{ 377 378 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 379 td->td_retval)); 380} 381 382/* 383 * Duplicate a file descriptor. 384 */ 385#ifndef _SYS_SYSPROTO_H_ 386struct dup_args { 387 u_int fd; 388}; 389#endif 390/* ARGSUSED */ 391int 392sys_dup(struct thread *td, struct dup_args *uap) 393{ 394 395 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval)); 396} 397 398/* 399 * The file control system call. 400 */ 401#ifndef _SYS_SYSPROTO_H_ 402struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406}; 407#endif 408/* ARGSUSED */ 409int 410sys_fcntl(struct thread *td, struct fcntl_args *uap) 411{ 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414} 415 416int 417kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 418{ 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 479 } 480 return (error); 481} 482 483int 484kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485{ 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 cap_rights_t rights; 493 int error, flg, tmp; 494 uint64_t bsize; 495 off_t foffset; 496 497 error = 0; 498 flg = F_POSIX; 499 p = td->td_proc; 500 fdp = p->p_fd; 501 502 switch (cmd) { 503 case F_DUPFD: 504 tmp = arg; 505 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval); 506 break; 507 508 case F_DUPFD_CLOEXEC: 509 tmp = arg; 510 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp, 511 td->td_retval); 512 break; 513 514 case F_DUP2FD: 515 tmp = arg; 516 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval); 517 break; 518 519 case F_DUP2FD_CLOEXEC: 520 tmp = arg; 521 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp, 522 td->td_retval); 523 break; 524 525 case F_GETFD: 526 FILEDESC_SLOCK(fdp); 527 if ((fp = fget_locked(fdp, fd)) == NULL) { 528 FILEDESC_SUNLOCK(fdp); 529 error = EBADF; 530 break; 531 } 532 fde = &fdp->fd_ofiles[fd]; 533 td->td_retval[0] = 534 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 535 FILEDESC_SUNLOCK(fdp); 536 break; 537 538 case F_SETFD: 539 FILEDESC_XLOCK(fdp); 540 if ((fp = fget_locked(fdp, fd)) == NULL) { 541 FILEDESC_XUNLOCK(fdp); 542 error = EBADF; 543 break; 544 } 545 fde = &fdp->fd_ofiles[fd]; 546 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 547 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 548 FILEDESC_XUNLOCK(fdp); 549 break; 550 551 case F_GETFL: 552 error = fget_unlocked(fdp, fd, 553 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp, NULL); 554 if (error != 0) 555 break; 556 td->td_retval[0] = OFLAGS(fp->f_flag); 557 fdrop(fp, td); 558 break; 559 560 case F_SETFL: 561 error = fget_unlocked(fdp, fd, 562 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp, NULL); 563 if (error != 0) 564 break; 565 do { 566 tmp = flg = fp->f_flag; 567 tmp &= ~FCNTLFLAGS; 568 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 569 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 570 tmp = fp->f_flag & FNONBLOCK; 571 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 572 if (error != 0) { 573 fdrop(fp, td); 574 break; 575 } 576 tmp = fp->f_flag & FASYNC; 577 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 578 if (error == 0) { 579 fdrop(fp, td); 580 break; 581 } 582 atomic_clear_int(&fp->f_flag, FNONBLOCK); 583 tmp = 0; 584 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 585 fdrop(fp, td); 586 break; 587 588 case F_GETOWN: 589 error = fget_unlocked(fdp, fd, 590 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp, NULL); 591 if (error != 0) 592 break; 593 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 594 if (error == 0) 595 td->td_retval[0] = tmp; 596 fdrop(fp, td); 597 break; 598 599 case F_SETOWN: 600 error = fget_unlocked(fdp, fd, 601 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp, NULL); 602 if (error != 0) 603 break; 604 tmp = arg; 605 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 606 fdrop(fp, td); 607 break; 608 609 case F_SETLK_REMOTE: 610 error = priv_check(td, PRIV_NFS_LOCKD); 611 if (error) 612 return (error); 613 flg = F_REMOTE; 614 goto do_setlk; 615 616 case F_SETLKW: 617 flg |= F_WAIT; 618 /* FALLTHROUGH F_SETLK */ 619 620 case F_SETLK: 621 do_setlk: 622 cap_rights_init(&rights, CAP_FLOCK); 623 error = fget_unlocked(fdp, fd, &rights, 0, &fp, NULL); 624 if (error != 0) 625 break; 626 if (fp->f_type != DTYPE_VNODE) { 627 error = EBADF; 628 fdrop(fp, td); 629 break; 630 } 631 632 flp = (struct flock *)arg; 633 if (flp->l_whence == SEEK_CUR) { 634 foffset = foffset_get(fp); 635 if (foffset < 0 || 636 (flp->l_start > 0 && 637 foffset > OFF_MAX - flp->l_start)) { 638 FILEDESC_SUNLOCK(fdp); 639 error = EOVERFLOW; 640 fdrop(fp, td); 641 break; 642 } 643 flp->l_start += foffset; 644 } 645 646 vp = fp->f_vnode; 647 switch (flp->l_type) { 648 case F_RDLCK: 649 if ((fp->f_flag & FREAD) == 0) { 650 error = EBADF; 651 break; 652 } 653 PROC_LOCK(p->p_leader); 654 p->p_leader->p_flag |= P_ADVLOCK; 655 PROC_UNLOCK(p->p_leader); 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_WRLCK: 660 if ((fp->f_flag & FWRITE) == 0) { 661 error = EBADF; 662 break; 663 } 664 PROC_LOCK(p->p_leader); 665 p->p_leader->p_flag |= P_ADVLOCK; 666 PROC_UNLOCK(p->p_leader); 667 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 668 flp, flg); 669 break; 670 case F_UNLCK: 671 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 672 flp, flg); 673 break; 674 case F_UNLCKSYS: 675 /* 676 * Temporary api for testing remote lock 677 * infrastructure. 678 */ 679 if (flg != F_REMOTE) { 680 error = EINVAL; 681 break; 682 } 683 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 684 F_UNLCKSYS, flp, flg); 685 break; 686 default: 687 error = EINVAL; 688 break; 689 } 690 if (error != 0 || flp->l_type == F_UNLCK || 691 flp->l_type == F_UNLCKSYS) { 692 fdrop(fp, td); 693 break; 694 } 695 696 /* 697 * Check for a race with close. 698 * 699 * The vnode is now advisory locked (or unlocked, but this case 700 * is not really important) as the caller requested. 701 * We had to drop the filedesc lock, so we need to recheck if 702 * the descriptor is still valid, because if it was closed 703 * in the meantime we need to remove advisory lock from the 704 * vnode - close on any descriptor leading to an advisory 705 * locked vnode, removes that lock. 706 * We will return 0 on purpose in that case, as the result of 707 * successful advisory lock might have been externally visible 708 * already. This is fine - effectively we pretend to the caller 709 * that the closing thread was a bit slower and that the 710 * advisory lock succeeded before the close. 711 */ 712 error = fget_unlocked(fdp, fd, &rights, 0, &fp2, NULL); 713 if (error != 0) { 714 fdrop(fp, td); 715 break; 716 } 717 if (fp != fp2) { 718 flp->l_whence = SEEK_SET; 719 flp->l_start = 0; 720 flp->l_len = 0; 721 flp->l_type = F_UNLCK; 722 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 723 F_UNLCK, flp, F_POSIX); 724 } 725 fdrop(fp, td); 726 fdrop(fp2, td); 727 break; 728 729 case F_GETLK: 730 error = fget_unlocked(fdp, fd, 731 cap_rights_init(&rights, CAP_FLOCK), 0, &fp, NULL); 732 if (error != 0) 733 break; 734 if (fp->f_type != DTYPE_VNODE) { 735 error = EBADF; 736 fdrop(fp, td); 737 break; 738 } 739 flp = (struct flock *)arg; 740 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 741 flp->l_type != F_UNLCK) { 742 error = EINVAL; 743 fdrop(fp, td); 744 break; 745 } 746 if (flp->l_whence == SEEK_CUR) { 747 foffset = foffset_get(fp); 748 if ((flp->l_start > 0 && 749 foffset > OFF_MAX - flp->l_start) || 750 (flp->l_start < 0 && 751 foffset < OFF_MIN - flp->l_start)) { 752 FILEDESC_SUNLOCK(fdp); 753 error = EOVERFLOW; 754 fdrop(fp, td); 755 break; 756 } 757 flp->l_start += foffset; 758 } 759 vp = fp->f_vnode; 760 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 761 F_POSIX); 762 fdrop(fp, td); 763 break; 764 765 case F_RDAHEAD: 766 arg = arg ? 128 * 1024: 0; 767 /* FALLTHROUGH */ 768 case F_READAHEAD: 769 error = fget_unlocked(fdp, fd, NULL, 0, &fp, NULL); 770 if (error != 0) 771 break; 772 if (fp->f_type != DTYPE_VNODE) { 773 fdrop(fp, td); 774 error = EBADF; 775 break; 776 } 777 vp = fp->f_vnode; 778 /* 779 * Exclusive lock synchronizes against f_seqcount reads and 780 * writes in sequential_heuristic(). 781 */ 782 error = vn_lock(vp, LK_EXCLUSIVE); 783 if (error != 0) { 784 fdrop(fp, td); 785 break; 786 } 787 if (arg >= 0) { 788 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 789 fp->f_seqcount = (arg + bsize - 1) / bsize; 790 atomic_set_int(&fp->f_flag, FRDAHEAD); 791 } else { 792 atomic_clear_int(&fp->f_flag, FRDAHEAD); 793 } 794 VOP_UNLOCK(vp, 0); 795 fdrop(fp, td); 796 break; 797 798 default: 799 error = EINVAL; 800 break; 801 } 802 return (error); 803} 804 805static int 806getmaxfd(struct proc *p) 807{ 808 int maxfd; 809 810 PROC_LOCK(p); 811 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 812 PROC_UNLOCK(p); 813 814 return (maxfd); 815} 816 817/* 818 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 819 */ 820int 821do_dup(struct thread *td, int flags, int old, int new, 822 register_t *retval) 823{ 824 struct filedesc *fdp; 825 struct filedescent *oldfde, *newfde; 826 struct proc *p; 827 struct file *fp; 828 struct file *delfp; 829 int error, maxfd; 830 831 p = td->td_proc; 832 fdp = p->p_fd; 833 834 /* 835 * Verify we have a valid descriptor to dup from and possibly to 836 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 837 * return EINVAL when the new descriptor is out of bounds. 838 */ 839 if (old < 0) 840 return (EBADF); 841 if (new < 0) 842 return (flags & DUP_FCNTL ? EINVAL : EBADF); 843 maxfd = getmaxfd(p); 844 if (new >= maxfd) 845 return (flags & DUP_FCNTL ? EINVAL : EBADF); 846 847 FILEDESC_XLOCK(fdp); 848 if (fget_locked(fdp, old) == NULL) { 849 FILEDESC_XUNLOCK(fdp); 850 return (EBADF); 851 } 852 oldfde = &fdp->fd_ofiles[old]; 853 if (flags & DUP_FIXED && old == new) { 854 *retval = new; 855 if (flags & DUP_CLOEXEC) 856 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 857 FILEDESC_XUNLOCK(fdp); 858 return (0); 859 } 860 fp = oldfde->fde_file; 861 fhold(fp); 862 863 /* 864 * If the caller specified a file descriptor, make sure the file 865 * table is large enough to hold it, and grab it. Otherwise, just 866 * allocate a new descriptor the usual way. 867 */ 868 if (flags & DUP_FIXED) { 869 if (new >= fdp->fd_nfiles) { 870 /* 871 * The resource limits are here instead of e.g. 872 * fdalloc(), because the file descriptor table may be 873 * shared between processes, so we can't really use 874 * racct_add()/racct_sub(). Instead of counting the 875 * number of actually allocated descriptors, just put 876 * the limit on the size of the file descriptor table. 877 */ 878#ifdef RACCT 879 if (racct_enable) { 880 PROC_LOCK(p); 881 error = racct_set(p, RACCT_NOFILE, new + 1); 882 PROC_UNLOCK(p); 883 if (error != 0) { 884 FILEDESC_XUNLOCK(fdp); 885 fdrop(fp, td); 886 return (EMFILE); 887 } 888 } 889#endif 890 fdgrowtable_exp(fdp, new + 1); 891 oldfde = &fdp->fd_ofiles[old]; 892 } 893 newfde = &fdp->fd_ofiles[new]; 894 if (newfde->fde_file == NULL) 895 fdused(fdp, new); 896 } else { 897 if ((error = fdalloc(td, new, &new)) != 0) { 898 FILEDESC_XUNLOCK(fdp); 899 fdrop(fp, td); 900 return (error); 901 } 902 newfde = &fdp->fd_ofiles[new]; 903 } 904 905 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 906 KASSERT(old != new, ("new fd is same as old")); 907 908 delfp = newfde->fde_file; 909 910 /* 911 * Duplicate the source descriptor. 912 */ 913#ifdef CAPABILITIES 914 seq_write_begin(&newfde->fde_seq); 915#endif 916 filecaps_free(&newfde->fde_caps); 917 memcpy(newfde, oldfde, fde_change_size); 918 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 919 if ((flags & DUP_CLOEXEC) != 0) 920 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 921 else 922 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 923#ifdef CAPABILITIES 924 seq_write_end(&newfde->fde_seq); 925#endif 926 *retval = new; 927 928 if (delfp != NULL) { 929 (void) closefp(fdp, new, delfp, td, 1); 930 /* closefp() drops the FILEDESC lock for us. */ 931 } else { 932 FILEDESC_XUNLOCK(fdp); 933 } 934 935 return (0); 936} 937 938/* 939 * If sigio is on the list associated with a process or process group, 940 * disable signalling from the device, remove sigio from the list and 941 * free sigio. 942 */ 943void 944funsetown(struct sigio **sigiop) 945{ 946 struct sigio *sigio; 947 948 SIGIO_LOCK(); 949 sigio = *sigiop; 950 if (sigio == NULL) { 951 SIGIO_UNLOCK(); 952 return; 953 } 954 *(sigio->sio_myref) = NULL; 955 if ((sigio)->sio_pgid < 0) { 956 struct pgrp *pg = (sigio)->sio_pgrp; 957 PGRP_LOCK(pg); 958 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 959 sigio, sio_pgsigio); 960 PGRP_UNLOCK(pg); 961 } else { 962 struct proc *p = (sigio)->sio_proc; 963 PROC_LOCK(p); 964 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 965 sigio, sio_pgsigio); 966 PROC_UNLOCK(p); 967 } 968 SIGIO_UNLOCK(); 969 crfree(sigio->sio_ucred); 970 free(sigio, M_SIGIO); 971} 972 973/* 974 * Free a list of sigio structures. 975 * We only need to lock the SIGIO_LOCK because we have made ourselves 976 * inaccessible to callers of fsetown and therefore do not need to lock 977 * the proc or pgrp struct for the list manipulation. 978 */ 979void 980funsetownlst(struct sigiolst *sigiolst) 981{ 982 struct proc *p; 983 struct pgrp *pg; 984 struct sigio *sigio; 985 986 sigio = SLIST_FIRST(sigiolst); 987 if (sigio == NULL) 988 return; 989 p = NULL; 990 pg = NULL; 991 992 /* 993 * Every entry of the list should belong 994 * to a single proc or pgrp. 995 */ 996 if (sigio->sio_pgid < 0) { 997 pg = sigio->sio_pgrp; 998 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 999 } else /* if (sigio->sio_pgid > 0) */ { 1000 p = sigio->sio_proc; 1001 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1002 } 1003 1004 SIGIO_LOCK(); 1005 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1006 *(sigio->sio_myref) = NULL; 1007 if (pg != NULL) { 1008 KASSERT(sigio->sio_pgid < 0, 1009 ("Proc sigio in pgrp sigio list")); 1010 KASSERT(sigio->sio_pgrp == pg, 1011 ("Bogus pgrp in sigio list")); 1012 PGRP_LOCK(pg); 1013 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1014 sio_pgsigio); 1015 PGRP_UNLOCK(pg); 1016 } else /* if (p != NULL) */ { 1017 KASSERT(sigio->sio_pgid > 0, 1018 ("Pgrp sigio in proc sigio list")); 1019 KASSERT(sigio->sio_proc == p, 1020 ("Bogus proc in sigio list")); 1021 PROC_LOCK(p); 1022 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1023 sio_pgsigio); 1024 PROC_UNLOCK(p); 1025 } 1026 SIGIO_UNLOCK(); 1027 crfree(sigio->sio_ucred); 1028 free(sigio, M_SIGIO); 1029 SIGIO_LOCK(); 1030 } 1031 SIGIO_UNLOCK(); 1032} 1033 1034/* 1035 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1036 * 1037 * After permission checking, add a sigio structure to the sigio list for 1038 * the process or process group. 1039 */ 1040int 1041fsetown(pid_t pgid, struct sigio **sigiop) 1042{ 1043 struct proc *proc; 1044 struct pgrp *pgrp; 1045 struct sigio *sigio; 1046 int ret; 1047 1048 if (pgid == 0) { 1049 funsetown(sigiop); 1050 return (0); 1051 } 1052 1053 ret = 0; 1054 1055 /* Allocate and fill in the new sigio out of locks. */ 1056 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1057 sigio->sio_pgid = pgid; 1058 sigio->sio_ucred = crhold(curthread->td_ucred); 1059 sigio->sio_myref = sigiop; 1060 1061 sx_slock(&proctree_lock); 1062 if (pgid > 0) { 1063 proc = pfind(pgid); 1064 if (proc == NULL) { 1065 ret = ESRCH; 1066 goto fail; 1067 } 1068 1069 /* 1070 * Policy - Don't allow a process to FSETOWN a process 1071 * in another session. 1072 * 1073 * Remove this test to allow maximum flexibility or 1074 * restrict FSETOWN to the current process or process 1075 * group for maximum safety. 1076 */ 1077 PROC_UNLOCK(proc); 1078 if (proc->p_session != curthread->td_proc->p_session) { 1079 ret = EPERM; 1080 goto fail; 1081 } 1082 1083 pgrp = NULL; 1084 } else /* if (pgid < 0) */ { 1085 pgrp = pgfind(-pgid); 1086 if (pgrp == NULL) { 1087 ret = ESRCH; 1088 goto fail; 1089 } 1090 PGRP_UNLOCK(pgrp); 1091 1092 /* 1093 * Policy - Don't allow a process to FSETOWN a process 1094 * in another session. 1095 * 1096 * Remove this test to allow maximum flexibility or 1097 * restrict FSETOWN to the current process or process 1098 * group for maximum safety. 1099 */ 1100 if (pgrp->pg_session != curthread->td_proc->p_session) { 1101 ret = EPERM; 1102 goto fail; 1103 } 1104 1105 proc = NULL; 1106 } 1107 funsetown(sigiop); 1108 if (pgid > 0) { 1109 PROC_LOCK(proc); 1110 /* 1111 * Since funsetownlst() is called without the proctree 1112 * locked, we need to check for P_WEXIT. 1113 * XXX: is ESRCH correct? 1114 */ 1115 if ((proc->p_flag & P_WEXIT) != 0) { 1116 PROC_UNLOCK(proc); 1117 ret = ESRCH; 1118 goto fail; 1119 } 1120 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1121 sigio->sio_proc = proc; 1122 PROC_UNLOCK(proc); 1123 } else { 1124 PGRP_LOCK(pgrp); 1125 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1126 sigio->sio_pgrp = pgrp; 1127 PGRP_UNLOCK(pgrp); 1128 } 1129 sx_sunlock(&proctree_lock); 1130 SIGIO_LOCK(); 1131 *sigiop = sigio; 1132 SIGIO_UNLOCK(); 1133 return (0); 1134 1135fail: 1136 sx_sunlock(&proctree_lock); 1137 crfree(sigio->sio_ucred); 1138 free(sigio, M_SIGIO); 1139 return (ret); 1140} 1141 1142/* 1143 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1144 */ 1145pid_t 1146fgetown(sigiop) 1147 struct sigio **sigiop; 1148{ 1149 pid_t pgid; 1150 1151 SIGIO_LOCK(); 1152 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1153 SIGIO_UNLOCK(); 1154 return (pgid); 1155} 1156 1157/* 1158 * Function drops the filedesc lock on return. 1159 */ 1160static int 1161closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1162 int holdleaders) 1163{ 1164 int error; 1165 1166 FILEDESC_XLOCK_ASSERT(fdp); 1167 1168 if (holdleaders) { 1169 if (td->td_proc->p_fdtol != NULL) { 1170 /* 1171 * Ask fdfree() to sleep to ensure that all relevant 1172 * process leaders can be traversed in closef(). 1173 */ 1174 fdp->fd_holdleaderscount++; 1175 } else { 1176 holdleaders = 0; 1177 } 1178 } 1179 1180 /* 1181 * We now hold the fp reference that used to be owned by the 1182 * descriptor array. We have to unlock the FILEDESC *AFTER* 1183 * knote_fdclose to prevent a race of the fd getting opened, a knote 1184 * added, and deleteing a knote for the new fd. 1185 */ 1186 knote_fdclose(td, fd); 1187 1188 /* 1189 * We need to notify mqueue if the object is of type mqueue. 1190 */ 1191 if (fp->f_type == DTYPE_MQUEUE) 1192 mq_fdclose(td, fd, fp); 1193 FILEDESC_XUNLOCK(fdp); 1194 1195 error = closef(fp, td); 1196 if (holdleaders) { 1197 FILEDESC_XLOCK(fdp); 1198 fdp->fd_holdleaderscount--; 1199 if (fdp->fd_holdleaderscount == 0 && 1200 fdp->fd_holdleaderswakeup != 0) { 1201 fdp->fd_holdleaderswakeup = 0; 1202 wakeup(&fdp->fd_holdleaderscount); 1203 } 1204 FILEDESC_XUNLOCK(fdp); 1205 } 1206 return (error); 1207} 1208 1209/* 1210 * Close a file descriptor. 1211 */ 1212#ifndef _SYS_SYSPROTO_H_ 1213struct close_args { 1214 int fd; 1215}; 1216#endif 1217/* ARGSUSED */ 1218int 1219sys_close(struct thread *td, struct close_args *uap) 1220{ 1221 1222 return (kern_close(td, uap->fd)); 1223} 1224 1225int 1226kern_close(struct thread *td, int fd) 1227{ 1228 struct filedesc *fdp; 1229 struct file *fp; 1230 1231 fdp = td->td_proc->p_fd; 1232 1233 AUDIT_SYSCLOSE(td, fd); 1234 1235 FILEDESC_XLOCK(fdp); 1236 if ((fp = fget_locked(fdp, fd)) == NULL) { 1237 FILEDESC_XUNLOCK(fdp); 1238 return (EBADF); 1239 } 1240 fdfree(fdp, fd); 1241 1242 /* closefp() drops the FILEDESC lock for us. */ 1243 return (closefp(fdp, fd, fp, td, 1)); 1244} 1245 1246/* 1247 * Close open file descriptors. 1248 */ 1249#ifndef _SYS_SYSPROTO_H_ 1250struct closefrom_args { 1251 int lowfd; 1252}; 1253#endif 1254/* ARGSUSED */ 1255int 1256sys_closefrom(struct thread *td, struct closefrom_args *uap) 1257{ 1258 struct filedesc *fdp; 1259 int fd; 1260 1261 fdp = td->td_proc->p_fd; 1262 AUDIT_ARG_FD(uap->lowfd); 1263 1264 /* 1265 * Treat negative starting file descriptor values identical to 1266 * closefrom(0) which closes all files. 1267 */ 1268 if (uap->lowfd < 0) 1269 uap->lowfd = 0; 1270 FILEDESC_SLOCK(fdp); 1271 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1272 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1273 FILEDESC_SUNLOCK(fdp); 1274 (void)kern_close(td, fd); 1275 FILEDESC_SLOCK(fdp); 1276 } 1277 } 1278 FILEDESC_SUNLOCK(fdp); 1279 return (0); 1280} 1281 1282#if defined(COMPAT_43) 1283/* 1284 * Return status information about a file descriptor. 1285 */ 1286#ifndef _SYS_SYSPROTO_H_ 1287struct ofstat_args { 1288 int fd; 1289 struct ostat *sb; 1290}; 1291#endif 1292/* ARGSUSED */ 1293int 1294ofstat(struct thread *td, struct ofstat_args *uap) 1295{ 1296 struct ostat oub; 1297 struct stat ub; 1298 int error; 1299 1300 error = kern_fstat(td, uap->fd, &ub); 1301 if (error == 0) { 1302 cvtstat(&ub, &oub); 1303 error = copyout(&oub, uap->sb, sizeof(oub)); 1304 } 1305 return (error); 1306} 1307#endif /* COMPAT_43 */ 1308 1309/* 1310 * Return status information about a file descriptor. 1311 */ 1312#ifndef _SYS_SYSPROTO_H_ 1313struct fstat_args { 1314 int fd; 1315 struct stat *sb; 1316}; 1317#endif 1318/* ARGSUSED */ 1319int 1320sys_fstat(struct thread *td, struct fstat_args *uap) 1321{ 1322 struct stat ub; 1323 int error; 1324 1325 error = kern_fstat(td, uap->fd, &ub); 1326 if (error == 0) 1327 error = copyout(&ub, uap->sb, sizeof(ub)); 1328 return (error); 1329} 1330 1331int 1332kern_fstat(struct thread *td, int fd, struct stat *sbp) 1333{ 1334 struct file *fp; 1335 cap_rights_t rights; 1336 int error; 1337 1338 AUDIT_ARG_FD(fd); 1339 1340 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1341 if (error != 0) 1342 return (error); 1343 1344 AUDIT_ARG_FILE(td->td_proc, fp); 1345 1346 error = fo_stat(fp, sbp, td->td_ucred, td); 1347 fdrop(fp, td); 1348#ifdef KTRACE 1349 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1350 ktrstat(sbp); 1351#endif 1352 return (error); 1353} 1354 1355/* 1356 * Return status information about a file descriptor. 1357 */ 1358#ifndef _SYS_SYSPROTO_H_ 1359struct nfstat_args { 1360 int fd; 1361 struct nstat *sb; 1362}; 1363#endif 1364/* ARGSUSED */ 1365int 1366sys_nfstat(struct thread *td, struct nfstat_args *uap) 1367{ 1368 struct nstat nub; 1369 struct stat ub; 1370 int error; 1371 1372 error = kern_fstat(td, uap->fd, &ub); 1373 if (error == 0) { 1374 cvtnstat(&ub, &nub); 1375 error = copyout(&nub, uap->sb, sizeof(nub)); 1376 } 1377 return (error); 1378} 1379 1380/* 1381 * Return pathconf information about a file descriptor. 1382 */ 1383#ifndef _SYS_SYSPROTO_H_ 1384struct fpathconf_args { 1385 int fd; 1386 int name; 1387}; 1388#endif 1389/* ARGSUSED */ 1390int 1391sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1392{ 1393 struct file *fp; 1394 struct vnode *vp; 1395 cap_rights_t rights; 1396 int error; 1397 1398 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1399 if (error != 0) 1400 return (error); 1401 1402 /* If asynchronous I/O is available, it works for all descriptors. */ 1403 if (uap->name == _PC_ASYNC_IO) { 1404 td->td_retval[0] = async_io_version; 1405 goto out; 1406 } 1407 vp = fp->f_vnode; 1408 if (vp != NULL) { 1409 vn_lock(vp, LK_SHARED | LK_RETRY); 1410 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1411 VOP_UNLOCK(vp, 0); 1412 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1413 if (uap->name != _PC_PIPE_BUF) { 1414 error = EINVAL; 1415 } else { 1416 td->td_retval[0] = PIPE_BUF; 1417 error = 0; 1418 } 1419 } else { 1420 error = EOPNOTSUPP; 1421 } 1422out: 1423 fdrop(fp, td); 1424 return (error); 1425} 1426 1427/* 1428 * Initialize filecaps structure. 1429 */ 1430void 1431filecaps_init(struct filecaps *fcaps) 1432{ 1433 1434 bzero(fcaps, sizeof(*fcaps)); 1435 fcaps->fc_nioctls = -1; 1436} 1437 1438/* 1439 * Copy filecaps structure allocating memory for ioctls array if needed. 1440 */ 1441void 1442filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1443{ 1444 size_t size; 1445 1446 *dst = *src; 1447 if (src->fc_ioctls != NULL) { 1448 KASSERT(src->fc_nioctls > 0, 1449 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1450 1451 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1452 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1453 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1454 } 1455} 1456 1457/* 1458 * Move filecaps structure to the new place and clear the old place. 1459 */ 1460void 1461filecaps_move(struct filecaps *src, struct filecaps *dst) 1462{ 1463 1464 *dst = *src; 1465 bzero(src, sizeof(*src)); 1466} 1467 1468/* 1469 * Fill the given filecaps structure with full rights. 1470 */ 1471static void 1472filecaps_fill(struct filecaps *fcaps) 1473{ 1474 1475 CAP_ALL(&fcaps->fc_rights); 1476 fcaps->fc_ioctls = NULL; 1477 fcaps->fc_nioctls = -1; 1478 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1479} 1480 1481/* 1482 * Free memory allocated within filecaps structure. 1483 */ 1484void 1485filecaps_free(struct filecaps *fcaps) 1486{ 1487 1488 free(fcaps->fc_ioctls, M_FILECAPS); 1489 bzero(fcaps, sizeof(*fcaps)); 1490} 1491 1492/* 1493 * Validate the given filecaps structure. 1494 */ 1495static void 1496filecaps_validate(const struct filecaps *fcaps, const char *func) 1497{ 1498 1499 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1500 ("%s: invalid rights", func)); 1501 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1502 ("%s: invalid fcntls", func)); 1503 KASSERT(fcaps->fc_fcntls == 0 || 1504 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1505 ("%s: fcntls without CAP_FCNTL", func)); 1506 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1507 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1508 ("%s: invalid ioctls", func)); 1509 KASSERT(fcaps->fc_nioctls == 0 || 1510 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1511 ("%s: ioctls without CAP_IOCTL", func)); 1512} 1513 1514static void 1515fdgrowtable_exp(struct filedesc *fdp, int nfd) 1516{ 1517 int nfd1; 1518 1519 FILEDESC_XLOCK_ASSERT(fdp); 1520 1521 nfd1 = fdp->fd_nfiles * 2; 1522 if (nfd1 < nfd) 1523 nfd1 = nfd; 1524 fdgrowtable(fdp, nfd1); 1525} 1526 1527/* 1528 * Grow the file table to accommodate (at least) nfd descriptors. 1529 */ 1530static void 1531fdgrowtable(struct filedesc *fdp, int nfd) 1532{ 1533 struct filedesc0 *fdp0; 1534 struct freetable *ft; 1535 struct filedescent *ntable; 1536 struct filedescent *otable; 1537 int nnfiles, onfiles; 1538 NDSLOTTYPE *nmap, *omap; 1539 1540 FILEDESC_XLOCK_ASSERT(fdp); 1541 1542 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1543 1544 /* save old values */ 1545 onfiles = fdp->fd_nfiles; 1546 otable = fdp->fd_ofiles; 1547 omap = fdp->fd_map; 1548 1549 /* compute the size of the new table */ 1550 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1551 if (nnfiles <= onfiles) 1552 /* the table is already large enough */ 1553 return; 1554 1555 /* 1556 * Allocate a new table. We need enough space for the 1557 * file entries themselves and the struct freetable we will use 1558 * when we decommission the table and place it on the freelist. 1559 * We place the struct freetable in the middle so we don't have 1560 * to worry about padding. 1561 */ 1562 ntable = malloc(nnfiles * sizeof(ntable[0]) + sizeof(struct freetable), 1563 M_FILEDESC, M_ZERO | M_WAITOK); 1564 /* copy the old data over and point at the new tables */ 1565 memcpy(ntable, otable, onfiles * sizeof(*otable)); 1566 fdp->fd_ofiles = ntable; 1567 1568 /* 1569 * Allocate a new map only if the old is not large enough. It will 1570 * grow at a slower rate than the table as it can map more 1571 * entries than the table can hold. 1572 */ 1573 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1574 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1575 M_ZERO | M_WAITOK); 1576 /* copy over the old data and update the pointer */ 1577 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1578 fdp->fd_map = nmap; 1579 } 1580 1581 /* 1582 * In order to have a valid pattern for fget_unlocked() 1583 * fdp->fd_nfiles must be the last member to be updated, otherwise 1584 * fget_unlocked() consumers may reference a new, higher value for 1585 * fdp->fd_nfiles before to access the fdp->fd_ofiles array, 1586 * resulting in OOB accesses. 1587 */ 1588 atomic_store_rel_int(&fdp->fd_nfiles, nnfiles); 1589 1590 /* 1591 * Do not free the old file table, as some threads may still 1592 * reference entries within it. Instead, place it on a freelist 1593 * which will be processed when the struct filedesc is released. 1594 * 1595 * Note that if onfiles == NDFILE, we're dealing with the original 1596 * static allocation contained within (struct filedesc0 *)fdp, 1597 * which must not be freed. 1598 */ 1599 if (onfiles > NDFILE) { 1600 ft = (struct freetable *)&otable[onfiles]; 1601 fdp0 = (struct filedesc0 *)fdp; 1602 ft->ft_table = otable; 1603 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1604 } 1605 /* 1606 * The map does not have the same possibility of threads still 1607 * holding references to it. So always free it as long as it 1608 * does not reference the original static allocation. 1609 */ 1610 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1611 free(omap, M_FILEDESC); 1612} 1613 1614/* 1615 * Allocate a file descriptor for the process. 1616 */ 1617int 1618fdalloc(struct thread *td, int minfd, int *result) 1619{ 1620 struct proc *p = td->td_proc; 1621 struct filedesc *fdp = p->p_fd; 1622 int fd = -1, maxfd, allocfd; 1623#ifdef RACCT 1624 int error; 1625#endif 1626 1627 FILEDESC_XLOCK_ASSERT(fdp); 1628 1629 if (fdp->fd_freefile > minfd) 1630 minfd = fdp->fd_freefile; 1631 1632 maxfd = getmaxfd(p); 1633 1634 /* 1635 * Search the bitmap for a free descriptor starting at minfd. 1636 * If none is found, grow the file table. 1637 */ 1638 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1639 if (fd >= maxfd) 1640 return (EMFILE); 1641 if (fd >= fdp->fd_nfiles) { 1642 allocfd = min(fd * 2, maxfd); 1643#ifdef RACCT 1644 if (racct_enable) { 1645 PROC_LOCK(p); 1646 error = racct_set(p, RACCT_NOFILE, allocfd); 1647 PROC_UNLOCK(p); 1648 if (error != 0) 1649 return (EMFILE); 1650 } 1651#endif 1652 /* 1653 * fd is already equal to first free descriptor >= minfd, so 1654 * we only need to grow the table and we are done. 1655 */ 1656 fdgrowtable_exp(fdp, allocfd); 1657 } 1658 1659 /* 1660 * Perform some sanity checks, then mark the file descriptor as 1661 * used and return it to the caller. 1662 */ 1663 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1664 ("invalid descriptor %d", fd)); 1665 KASSERT(!fdisused(fdp, fd), 1666 ("fd_first_free() returned non-free descriptor")); 1667 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1668 ("file descriptor isn't free")); 1669 KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set")); 1670 fdused(fdp, fd); 1671 *result = fd; 1672 return (0); 1673} 1674 1675/* 1676 * Allocate n file descriptors for the process. 1677 */ 1678int 1679fdallocn(struct thread *td, int minfd, int *fds, int n) 1680{ 1681 struct proc *p = td->td_proc; 1682 struct filedesc *fdp = p->p_fd; 1683 int i; 1684 1685 FILEDESC_XLOCK_ASSERT(fdp); 1686 1687 if (!fdavail(td, n)) 1688 return (EMFILE); 1689 1690 for (i = 0; i < n; i++) 1691 if (fdalloc(td, 0, &fds[i]) != 0) 1692 break; 1693 1694 if (i < n) { 1695 for (i--; i >= 0; i--) 1696 fdunused(fdp, fds[i]); 1697 return (EMFILE); 1698 } 1699 1700 return (0); 1701} 1702 1703/* 1704 * Check to see whether n user file descriptors are available to the process 1705 * p. 1706 */ 1707int 1708fdavail(struct thread *td, int n) 1709{ 1710 struct proc *p = td->td_proc; 1711 struct filedesc *fdp = td->td_proc->p_fd; 1712 int i, lim, last; 1713 1714 FILEDESC_LOCK_ASSERT(fdp); 1715 1716 /* 1717 * XXX: This is only called from uipc_usrreq.c:unp_externalize(); 1718 * call racct_add() from there instead of dealing with containers 1719 * here. 1720 */ 1721 lim = getmaxfd(p); 1722 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1723 return (1); 1724 last = min(fdp->fd_nfiles, lim); 1725 for (i = fdp->fd_freefile; i < last; i++) { 1726 if (fdp->fd_ofiles[i].fde_file == NULL && --n <= 0) 1727 return (1); 1728 } 1729 return (0); 1730} 1731 1732/* 1733 * Create a new open file structure and allocate a file descriptor for the 1734 * process that refers to it. We add one reference to the file for the 1735 * descriptor table and one reference for resultfp. This is to prevent us 1736 * being preempted and the entry in the descriptor table closed after we 1737 * release the FILEDESC lock. 1738 */ 1739int 1740falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1741{ 1742 struct file *fp; 1743 int error, fd; 1744 1745 error = falloc_noinstall(td, &fp); 1746 if (error) 1747 return (error); /* no reference held on error */ 1748 1749 error = finstall(td, fp, &fd, flags, NULL); 1750 if (error) { 1751 fdrop(fp, td); /* one reference (fp only) */ 1752 return (error); 1753 } 1754 1755 if (resultfp != NULL) 1756 *resultfp = fp; /* copy out result */ 1757 else 1758 fdrop(fp, td); /* release local reference */ 1759 1760 if (resultfd != NULL) 1761 *resultfd = fd; 1762 1763 return (0); 1764} 1765 1766/* 1767 * Create a new open file structure without allocating a file descriptor. 1768 */ 1769int 1770falloc_noinstall(struct thread *td, struct file **resultfp) 1771{ 1772 struct file *fp; 1773 int maxuserfiles = maxfiles - (maxfiles / 20); 1774 static struct timeval lastfail; 1775 static int curfail; 1776 1777 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1778 1779 if ((openfiles >= maxuserfiles && 1780 priv_check(td, PRIV_MAXFILES) != 0) || 1781 openfiles >= maxfiles) { 1782 if (ppsratecheck(&lastfail, &curfail, 1)) { 1783 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1784 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1785 } 1786 return (ENFILE); 1787 } 1788 atomic_add_int(&openfiles, 1); 1789 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1790 refcount_init(&fp->f_count, 1); 1791 fp->f_cred = crhold(td->td_ucred); 1792 fp->f_ops = &badfileops; 1793 fp->f_data = NULL; 1794 fp->f_vnode = NULL; 1795 *resultfp = fp; 1796 return (0); 1797} 1798 1799/* 1800 * Install a file in a file descriptor table. 1801 */ 1802int 1803finstall(struct thread *td, struct file *fp, int *fd, int flags, 1804 struct filecaps *fcaps) 1805{ 1806 struct filedesc *fdp = td->td_proc->p_fd; 1807 struct filedescent *fde; 1808 int error; 1809 1810 KASSERT(fd != NULL, ("%s: fd == NULL", __func__)); 1811 KASSERT(fp != NULL, ("%s: fp == NULL", __func__)); 1812 if (fcaps != NULL) 1813 filecaps_validate(fcaps, __func__); 1814 1815 FILEDESC_XLOCK(fdp); 1816 if ((error = fdalloc(td, 0, fd))) { 1817 FILEDESC_XUNLOCK(fdp); 1818 return (error); 1819 } 1820 fhold(fp); 1821 fde = &fdp->fd_ofiles[*fd]; 1822#ifdef CAPABILITIES 1823 seq_write_begin(&fde->fde_seq); 1824#endif 1825 fde->fde_file = fp; 1826 if ((flags & O_CLOEXEC) != 0) 1827 fde->fde_flags |= UF_EXCLOSE; 1828 if (fcaps != NULL) 1829 filecaps_move(fcaps, &fde->fde_caps); 1830 else 1831 filecaps_fill(&fde->fde_caps); 1832#ifdef CAPABILITIES 1833 seq_write_end(&fde->fde_seq); 1834#endif 1835 FILEDESC_XUNLOCK(fdp); 1836 return (0); 1837} 1838 1839/* 1840 * Build a new filedesc structure from another. 1841 * Copy the current, root, and jail root vnode references. 1842 */ 1843struct filedesc * 1844fdinit(struct filedesc *fdp) 1845{ 1846 struct filedesc0 *newfdp; 1847 1848 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO); 1849 FILEDESC_LOCK_INIT(&newfdp->fd_fd); 1850 if (fdp != NULL) { 1851 FILEDESC_SLOCK(fdp); 1852 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1853 if (newfdp->fd_fd.fd_cdir) 1854 VREF(newfdp->fd_fd.fd_cdir); 1855 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1856 if (newfdp->fd_fd.fd_rdir) 1857 VREF(newfdp->fd_fd.fd_rdir); 1858 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1859 if (newfdp->fd_fd.fd_jdir) 1860 VREF(newfdp->fd_fd.fd_jdir); 1861 FILEDESC_SUNLOCK(fdp); 1862 } 1863 1864 /* Create the file descriptor table. */ 1865 newfdp->fd_fd.fd_refcnt = 1; 1866 newfdp->fd_fd.fd_holdcnt = 1; 1867 newfdp->fd_fd.fd_cmask = CMASK; 1868 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1869 newfdp->fd_fd.fd_nfiles = NDFILE; 1870 newfdp->fd_fd.fd_map = newfdp->fd_dmap; 1871 newfdp->fd_fd.fd_lastfile = -1; 1872 return (&newfdp->fd_fd); 1873} 1874 1875static struct filedesc * 1876fdhold(struct proc *p) 1877{ 1878 struct filedesc *fdp; 1879 1880 mtx_lock(&fdesc_mtx); 1881 fdp = p->p_fd; 1882 if (fdp != NULL) 1883 fdp->fd_holdcnt++; 1884 mtx_unlock(&fdesc_mtx); 1885 return (fdp); 1886} 1887 1888static void 1889fddrop(struct filedesc *fdp) 1890{ 1891 struct filedesc0 *fdp0; 1892 struct freetable *ft; 1893 int i; 1894 1895 mtx_lock(&fdesc_mtx); 1896 i = --fdp->fd_holdcnt; 1897 mtx_unlock(&fdesc_mtx); 1898 if (i > 0) 1899 return; 1900 1901 FILEDESC_LOCK_DESTROY(fdp); 1902 fdp0 = (struct filedesc0 *)fdp; 1903 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) { 1904 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next); 1905 free(ft->ft_table, M_FILEDESC); 1906 } 1907 free(fdp, M_FILEDESC); 1908} 1909 1910/* 1911 * Share a filedesc structure. 1912 */ 1913struct filedesc * 1914fdshare(struct filedesc *fdp) 1915{ 1916 1917 FILEDESC_XLOCK(fdp); 1918 fdp->fd_refcnt++; 1919 FILEDESC_XUNLOCK(fdp); 1920 return (fdp); 1921} 1922 1923/* 1924 * Unshare a filedesc structure, if necessary by making a copy 1925 */ 1926void 1927fdunshare(struct thread *td) 1928{ 1929 struct filedesc *tmp; 1930 struct proc *p = td->td_proc; 1931 1932 if (p->p_fd->fd_refcnt == 1) 1933 return; 1934 1935 tmp = fdcopy(p->p_fd); 1936 fdescfree(td); 1937 p->p_fd = tmp; 1938} 1939 1940/* 1941 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1942 * this is to ease callers, not catch errors. 1943 */ 1944struct filedesc * 1945fdcopy(struct filedesc *fdp) 1946{ 1947 struct filedesc *newfdp; 1948 struct filedescent *nfde, *ofde; 1949 int i; 1950 1951 /* Certain daemons might not have file descriptors. */ 1952 if (fdp == NULL) 1953 return (NULL); 1954 1955 newfdp = fdinit(fdp); 1956 FILEDESC_SLOCK(fdp); 1957 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1958 FILEDESC_SUNLOCK(fdp); 1959 FILEDESC_XLOCK(newfdp); 1960 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1961 FILEDESC_XUNLOCK(newfdp); 1962 FILEDESC_SLOCK(fdp); 1963 } 1964 /* copy all passable descriptors (i.e. not kqueue) */ 1965 newfdp->fd_freefile = -1; 1966 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1967 ofde = &fdp->fd_ofiles[i]; 1968 if (fdisused(fdp, i) && 1969 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) && 1970 ofde->fde_file->f_ops != &badfileops) { 1971 nfde = &newfdp->fd_ofiles[i]; 1972 *nfde = *ofde; 1973 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1974 fhold(nfde->fde_file); 1975 newfdp->fd_lastfile = i; 1976 } else { 1977 if (newfdp->fd_freefile == -1) 1978 newfdp->fd_freefile = i; 1979 } 1980 } 1981 newfdp->fd_cmask = fdp->fd_cmask; 1982 FILEDESC_SUNLOCK(fdp); 1983 FILEDESC_XLOCK(newfdp); 1984 for (i = 0; i <= newfdp->fd_lastfile; ++i) { 1985 if (newfdp->fd_ofiles[i].fde_file != NULL) 1986 fdused(newfdp, i); 1987 } 1988 if (newfdp->fd_freefile == -1) 1989 newfdp->fd_freefile = i; 1990 FILEDESC_XUNLOCK(newfdp); 1991 return (newfdp); 1992} 1993 1994/* 1995 * Release a filedesc structure. 1996 */ 1997void 1998fdescfree(struct thread *td) 1999{ 2000 struct filedesc *fdp; 2001 int i; 2002 struct filedesc_to_leader *fdtol; 2003 struct file *fp; 2004 struct vnode *cdir, *jdir, *rdir, *vp; 2005 struct flock lf; 2006 2007 /* Certain daemons might not have file descriptors. */ 2008 fdp = td->td_proc->p_fd; 2009 if (fdp == NULL) 2010 return; 2011 2012#ifdef RACCT 2013 if (racct_enable) { 2014 PROC_LOCK(td->td_proc); 2015 racct_set(td->td_proc, RACCT_NOFILE, 0); 2016 PROC_UNLOCK(td->td_proc); 2017 } 2018#endif 2019 2020 /* Check for special need to clear POSIX style locks */ 2021 fdtol = td->td_proc->p_fdtol; 2022 if (fdtol != NULL) { 2023 FILEDESC_XLOCK(fdp); 2024 KASSERT(fdtol->fdl_refcount > 0, 2025 ("filedesc_to_refcount botch: fdl_refcount=%d", 2026 fdtol->fdl_refcount)); 2027 if (fdtol->fdl_refcount == 1 && 2028 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2029 for (i = 0; i <= fdp->fd_lastfile; i++) { 2030 fp = fdp->fd_ofiles[i].fde_file; 2031 if (fp == NULL || fp->f_type != DTYPE_VNODE) 2032 continue; 2033 fhold(fp); 2034 FILEDESC_XUNLOCK(fdp); 2035 lf.l_whence = SEEK_SET; 2036 lf.l_start = 0; 2037 lf.l_len = 0; 2038 lf.l_type = F_UNLCK; 2039 vp = fp->f_vnode; 2040 (void) VOP_ADVLOCK(vp, 2041 (caddr_t)td->td_proc->p_leader, F_UNLCK, 2042 &lf, F_POSIX); 2043 FILEDESC_XLOCK(fdp); 2044 fdrop(fp, td); 2045 } 2046 } 2047 retry: 2048 if (fdtol->fdl_refcount == 1) { 2049 if (fdp->fd_holdleaderscount > 0 && 2050 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2051 /* 2052 * close() or do_dup() has cleared a reference 2053 * in a shared file descriptor table. 2054 */ 2055 fdp->fd_holdleaderswakeup = 1; 2056 sx_sleep(&fdp->fd_holdleaderscount, 2057 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2058 goto retry; 2059 } 2060 if (fdtol->fdl_holdcount > 0) { 2061 /* 2062 * Ensure that fdtol->fdl_leader remains 2063 * valid in closef(). 2064 */ 2065 fdtol->fdl_wakeup = 1; 2066 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2067 "fdlhold", 0); 2068 goto retry; 2069 } 2070 } 2071 fdtol->fdl_refcount--; 2072 if (fdtol->fdl_refcount == 0 && 2073 fdtol->fdl_holdcount == 0) { 2074 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2075 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2076 } else 2077 fdtol = NULL; 2078 td->td_proc->p_fdtol = NULL; 2079 FILEDESC_XUNLOCK(fdp); 2080 if (fdtol != NULL) 2081 free(fdtol, M_FILEDESC_TO_LEADER); 2082 } 2083 2084 mtx_lock(&fdesc_mtx); 2085 td->td_proc->p_fd = NULL; 2086 mtx_unlock(&fdesc_mtx); 2087 2088 FILEDESC_XLOCK(fdp); 2089 i = --fdp->fd_refcnt; 2090 if (i > 0) { 2091 FILEDESC_XUNLOCK(fdp); 2092 return; 2093 } 2094 2095 cdir = fdp->fd_cdir; 2096 fdp->fd_cdir = NULL; 2097 rdir = fdp->fd_rdir; 2098 fdp->fd_rdir = NULL; 2099 jdir = fdp->fd_jdir; 2100 fdp->fd_jdir = NULL; 2101 FILEDESC_XUNLOCK(fdp); 2102 2103 for (i = 0; i <= fdp->fd_lastfile; i++) { 2104 fp = fdp->fd_ofiles[i].fde_file; 2105 if (fp != NULL) { 2106 fdfree_last(fdp, i); 2107 (void) closef(fp, td); 2108 } 2109 } 2110 2111 if (fdp->fd_nfiles > NDFILE) 2112 free(fdp->fd_ofiles, M_FILEDESC); 2113 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2114 free(fdp->fd_map, M_FILEDESC); 2115 2116 if (cdir != NULL) 2117 vrele(cdir); 2118 if (rdir != NULL) 2119 vrele(rdir); 2120 if (jdir != NULL) 2121 vrele(jdir); 2122 2123 fddrop(fdp); 2124} 2125 2126/* 2127 * For setugid programs, we don't want to people to use that setugidness 2128 * to generate error messages which write to a file which otherwise would 2129 * otherwise be off-limits to the process. We check for filesystems where 2130 * the vnode can change out from under us after execve (like [lin]procfs). 2131 * 2132 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 2133 * sufficient. We also don't check for setugidness since we know we are. 2134 */ 2135static int 2136is_unsafe(struct file *fp) 2137{ 2138 if (fp->f_type == DTYPE_VNODE) { 2139 struct vnode *vp = fp->f_vnode; 2140 2141 if ((vp->v_vflag & VV_PROCDEP) != 0) 2142 return (1); 2143 } 2144 return (0); 2145} 2146 2147/* 2148 * Make this setguid thing safe, if at all possible. 2149 */ 2150void 2151setugidsafety(struct thread *td) 2152{ 2153 struct filedesc *fdp; 2154 struct file *fp; 2155 int i; 2156 2157 fdp = td->td_proc->p_fd; 2158 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2159 FILEDESC_XLOCK(fdp); 2160 for (i = 0; i <= fdp->fd_lastfile; i++) { 2161 if (i > 2) 2162 break; 2163 fp = fdp->fd_ofiles[i].fde_file; 2164 if (fp != NULL && is_unsafe(fp)) { 2165 knote_fdclose(td, i); 2166 /* 2167 * NULL-out descriptor prior to close to avoid 2168 * a race while close blocks. 2169 */ 2170 fdfree(fdp, i); 2171 FILEDESC_XUNLOCK(fdp); 2172 (void) closef(fp, td); 2173 FILEDESC_XLOCK(fdp); 2174 } 2175 } 2176 FILEDESC_XUNLOCK(fdp); 2177} 2178 2179/* 2180 * If a specific file object occupies a specific file descriptor, close the 2181 * file descriptor entry and drop a reference on the file object. This is a 2182 * convenience function to handle a subsequent error in a function that calls 2183 * falloc() that handles the race that another thread might have closed the 2184 * file descriptor out from under the thread creating the file object. 2185 */ 2186void 2187fdclose(struct thread *td, struct file *fp, int idx) 2188{ 2189 struct filedesc *fdp = td->td_proc->p_fd; 2190 2191 FILEDESC_XLOCK(fdp); 2192 if (fdp->fd_ofiles[idx].fde_file == fp) { 2193 fdfree(fdp, idx); 2194 FILEDESC_XUNLOCK(fdp); 2195 fdrop(fp, td); 2196 } else 2197 FILEDESC_XUNLOCK(fdp); 2198} 2199 2200/* 2201 * Close any files on exec? 2202 */ 2203void 2204fdcloseexec(struct thread *td) 2205{ 2206 struct filedesc *fdp; 2207 struct filedescent *fde; 2208 struct file *fp; 2209 int i; 2210 2211 fdp = td->td_proc->p_fd; 2212 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2213 FILEDESC_XLOCK(fdp); 2214 for (i = 0; i <= fdp->fd_lastfile; i++) { 2215 fde = &fdp->fd_ofiles[i]; 2216 fp = fde->fde_file; 2217 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2218 (fde->fde_flags & UF_EXCLOSE))) { 2219 fdfree(fdp, i); 2220 (void) closefp(fdp, i, fp, td, 0); 2221 /* closefp() drops the FILEDESC lock. */ 2222 FILEDESC_XLOCK(fdp); 2223 } 2224 } 2225 FILEDESC_XUNLOCK(fdp); 2226} 2227 2228/* 2229 * It is unsafe for set[ug]id processes to be started with file 2230 * descriptors 0..2 closed, as these descriptors are given implicit 2231 * significance in the Standard C library. fdcheckstd() will create a 2232 * descriptor referencing /dev/null for each of stdin, stdout, and 2233 * stderr that is not already open. 2234 */ 2235int 2236fdcheckstd(struct thread *td) 2237{ 2238 struct filedesc *fdp; 2239 register_t retval, save; 2240 int i, error, devnull; 2241 2242 fdp = td->td_proc->p_fd; 2243 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2244 devnull = -1; 2245 error = 0; 2246 for (i = 0; i < 3; i++) { 2247 if (fdp->fd_ofiles[i].fde_file != NULL) 2248 continue; 2249 if (devnull < 0) { 2250 save = td->td_retval[0]; 2251 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 2252 O_RDWR, 0); 2253 devnull = td->td_retval[0]; 2254 td->td_retval[0] = save; 2255 if (error) 2256 break; 2257 KASSERT(devnull == i, ("oof, we didn't get our fd")); 2258 } else { 2259 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 2260 if (error != 0) 2261 break; 2262 } 2263 } 2264 return (error); 2265} 2266 2267/* 2268 * Internal form of close. Decrement reference count on file structure. 2269 * Note: td may be NULL when closing a file that was being passed in a 2270 * message. 2271 * 2272 * XXXRW: Giant is not required for the caller, but often will be held; this 2273 * makes it moderately likely the Giant will be recursed in the VFS case. 2274 */ 2275int 2276closef(struct file *fp, struct thread *td) 2277{ 2278 struct vnode *vp; 2279 struct flock lf; 2280 struct filedesc_to_leader *fdtol; 2281 struct filedesc *fdp; 2282 2283 /* 2284 * POSIX record locking dictates that any close releases ALL 2285 * locks owned by this process. This is handled by setting 2286 * a flag in the unlock to free ONLY locks obeying POSIX 2287 * semantics, and not to free BSD-style file locks. 2288 * If the descriptor was in a message, POSIX-style locks 2289 * aren't passed with the descriptor, and the thread pointer 2290 * will be NULL. Callers should be careful only to pass a 2291 * NULL thread pointer when there really is no owning 2292 * context that might have locks, or the locks will be 2293 * leaked. 2294 */ 2295 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2296 vp = fp->f_vnode; 2297 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2298 lf.l_whence = SEEK_SET; 2299 lf.l_start = 0; 2300 lf.l_len = 0; 2301 lf.l_type = F_UNLCK; 2302 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2303 F_UNLCK, &lf, F_POSIX); 2304 } 2305 fdtol = td->td_proc->p_fdtol; 2306 if (fdtol != NULL) { 2307 /* 2308 * Handle special case where file descriptor table is 2309 * shared between multiple process leaders. 2310 */ 2311 fdp = td->td_proc->p_fd; 2312 FILEDESC_XLOCK(fdp); 2313 for (fdtol = fdtol->fdl_next; 2314 fdtol != td->td_proc->p_fdtol; 2315 fdtol = fdtol->fdl_next) { 2316 if ((fdtol->fdl_leader->p_flag & 2317 P_ADVLOCK) == 0) 2318 continue; 2319 fdtol->fdl_holdcount++; 2320 FILEDESC_XUNLOCK(fdp); 2321 lf.l_whence = SEEK_SET; 2322 lf.l_start = 0; 2323 lf.l_len = 0; 2324 lf.l_type = F_UNLCK; 2325 vp = fp->f_vnode; 2326 (void) VOP_ADVLOCK(vp, 2327 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2328 F_POSIX); 2329 FILEDESC_XLOCK(fdp); 2330 fdtol->fdl_holdcount--; 2331 if (fdtol->fdl_holdcount == 0 && 2332 fdtol->fdl_wakeup != 0) { 2333 fdtol->fdl_wakeup = 0; 2334 wakeup(fdtol); 2335 } 2336 } 2337 FILEDESC_XUNLOCK(fdp); 2338 } 2339 } 2340 return (fdrop(fp, td)); 2341} 2342 2343/* 2344 * Initialize the file pointer with the specified properties. 2345 * 2346 * The ops are set with release semantics to be certain that the flags, type, 2347 * and data are visible when ops is. This is to prevent ops methods from being 2348 * called with bad data. 2349 */ 2350void 2351finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2352{ 2353 fp->f_data = data; 2354 fp->f_flag = flag; 2355 fp->f_type = type; 2356 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2357} 2358 2359int 2360fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2361 int needfcntl, struct file **fpp, cap_rights_t *haverightsp) 2362{ 2363#ifdef CAPABILITIES 2364 struct filedescent fde; 2365#endif 2366 struct file *fp; 2367 u_int count; 2368#ifdef CAPABILITIES 2369 seq_t seq; 2370 cap_rights_t haverights; 2371 int error; 2372#endif 2373 2374 /* 2375 * Avoid reads reordering and then a first access to the 2376 * fdp->fd_ofiles table which could result in OOB operation. 2377 */ 2378 if (fd < 0 || fd >= atomic_load_acq_int(&fdp->fd_nfiles)) 2379 return (EBADF); 2380 /* 2381 * Fetch the descriptor locklessly. We avoid fdrop() races by 2382 * never raising a refcount above 0. To accomplish this we have 2383 * to use a cmpset loop rather than an atomic_add. The descriptor 2384 * must be re-verified once we acquire a reference to be certain 2385 * that the identity is still correct and we did not lose a race 2386 * due to preemption. 2387 */ 2388 for (;;) { 2389#ifdef CAPABILITIES 2390 seq = seq_read(fd_seq(fdp, fd)); 2391 fde = fdp->fd_ofiles[fd]; 2392 if (!seq_consistent(fd_seq(fdp, fd), seq)) { 2393 cpu_spinwait(); 2394 continue; 2395 } 2396 fp = fde.fde_file; 2397#else 2398 fp = fdp->fd_ofiles[fd].fde_file; 2399#endif 2400 if (fp == NULL) 2401 return (EBADF); 2402#ifdef CAPABILITIES 2403 haverights = *cap_rights_fde(&fde); 2404 if (needrightsp != NULL) { 2405 error = cap_check(&haverights, needrightsp); 2406 if (error != 0) 2407 return (error); 2408 if (cap_rights_is_set(needrightsp, CAP_FCNTL)) { 2409 error = cap_fcntl_check_fde(&fde, needfcntl); 2410 if (error != 0) 2411 return (error); 2412 } 2413 } 2414#endif 2415 count = fp->f_count; 2416 if (count == 0) 2417 continue; 2418 /* 2419 * Use an acquire barrier to prevent caching of fd_ofiles 2420 * so it is refreshed for verification. 2421 */ 2422 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1) 2423 continue; 2424#ifdef CAPABILITIES 2425 if (seq_consistent_nomb(fd_seq(fdp, fd), seq)) 2426#else 2427 if (fp == fdp->fd_ofiles[fd].fde_file) 2428#endif 2429 break; 2430 fdrop(fp, curthread); 2431 } 2432 *fpp = fp; 2433 if (haverightsp != NULL) { 2434#ifdef CAPABILITIES 2435 *haverightsp = haverights; 2436#else 2437 CAP_ALL(haverightsp); 2438#endif 2439 } 2440 return (0); 2441} 2442 2443/* 2444 * Extract the file pointer associated with the specified descriptor for the 2445 * current user process. 2446 * 2447 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2448 * returned. 2449 * 2450 * File's rights will be checked against the capability rights mask. 2451 * 2452 * If an error occurred the non-zero error is returned and *fpp is set to 2453 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2454 * responsible for fdrop(). 2455 */ 2456static __inline int 2457_fget(struct thread *td, int fd, struct file **fpp, int flags, 2458 cap_rights_t *needrightsp, u_char *maxprotp) 2459{ 2460 struct filedesc *fdp; 2461 struct file *fp; 2462 cap_rights_t haverights, needrights; 2463 int error; 2464 2465 *fpp = NULL; 2466 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2467 return (EBADF); 2468 if (needrightsp != NULL) 2469 needrights = *needrightsp; 2470 else 2471 cap_rights_init(&needrights); 2472 if (maxprotp != NULL) 2473 cap_rights_set(&needrights, CAP_MMAP); 2474 error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights); 2475 if (error != 0) 2476 return (error); 2477 if (fp->f_ops == &badfileops) { 2478 fdrop(fp, td); 2479 return (EBADF); 2480 } 2481 2482#ifdef CAPABILITIES 2483 /* 2484 * If requested, convert capability rights to access flags. 2485 */ 2486 if (maxprotp != NULL) 2487 *maxprotp = cap_rights_to_vmprot(&haverights); 2488#else /* !CAPABILITIES */ 2489 if (maxprotp != NULL) 2490 *maxprotp = VM_PROT_ALL; 2491#endif /* CAPABILITIES */ 2492 2493 /* 2494 * FREAD and FWRITE failure return EBADF as per POSIX. 2495 */ 2496 error = 0; 2497 switch (flags) { 2498 case FREAD: 2499 case FWRITE: 2500 if ((fp->f_flag & flags) == 0) 2501 error = EBADF; 2502 break; 2503 case FEXEC: 2504 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2505 ((fp->f_flag & FWRITE) != 0)) 2506 error = EBADF; 2507 break; 2508 case 0: 2509 break; 2510 default: 2511 KASSERT(0, ("wrong flags")); 2512 } 2513 2514 if (error != 0) { 2515 fdrop(fp, td); 2516 return (error); 2517 } 2518 2519 *fpp = fp; 2520 return (0); 2521} 2522 2523int 2524fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2525{ 2526 2527 return(_fget(td, fd, fpp, 0, rightsp, NULL)); 2528} 2529 2530int 2531fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2532 struct file **fpp) 2533{ 2534 2535 return (_fget(td, fd, fpp, 0, rightsp, maxprotp)); 2536} 2537 2538int 2539fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2540{ 2541 2542 return(_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2543} 2544 2545int 2546fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2547{ 2548 2549 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2550} 2551 2552/* 2553 * Like fget() but loads the underlying vnode, or returns an error if the 2554 * descriptor does not represent a vnode. Note that pipes use vnodes but 2555 * never have VM objects. The returned vnode will be vref()'d. 2556 * 2557 * XXX: what about the unused flags ? 2558 */ 2559static __inline int 2560_fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2561 struct vnode **vpp) 2562{ 2563 struct file *fp; 2564 int error; 2565 2566 *vpp = NULL; 2567 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2568 if (error != 0) 2569 return (error); 2570 if (fp->f_vnode == NULL) { 2571 error = EINVAL; 2572 } else { 2573 *vpp = fp->f_vnode; 2574 vref(*vpp); 2575 } 2576 fdrop(fp, td); 2577 2578 return (error); 2579} 2580 2581int 2582fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2583{ 2584 2585 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2586} 2587 2588int 2589fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2590 struct filecaps *havecaps, struct vnode **vpp) 2591{ 2592 struct filedesc *fdp; 2593 struct file *fp; 2594#ifdef CAPABILITIES 2595 int error; 2596#endif 2597 2598 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2599 return (EBADF); 2600 2601 fp = fget_locked(fdp, fd); 2602 if (fp == NULL || fp->f_ops == &badfileops) 2603 return (EBADF); 2604 2605#ifdef CAPABILITIES 2606 if (needrightsp != NULL) { 2607 error = cap_check(cap_rights(fdp, fd), needrightsp); 2608 if (error != 0) 2609 return (error); 2610 } 2611#endif 2612 2613 if (fp->f_vnode == NULL) 2614 return (EINVAL); 2615 2616 *vpp = fp->f_vnode; 2617 vref(*vpp); 2618 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2619 2620 return (0); 2621} 2622 2623int 2624fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2625{ 2626 2627 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2628} 2629 2630int 2631fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2632{ 2633 2634 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2635} 2636 2637#ifdef notyet 2638int 2639fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2640 struct vnode **vpp) 2641{ 2642 2643 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2644} 2645#endif 2646 2647/* 2648 * Like fget() but loads the underlying socket, or returns an error if the 2649 * descriptor does not represent a socket. 2650 * 2651 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2652 * in the future. 2653 * 2654 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2655 * on their file descriptor reference to prevent the socket from being free'd 2656 * during use. 2657 */ 2658int 2659fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2660 u_int *fflagp) 2661{ 2662 struct file *fp; 2663 int error; 2664 2665 *spp = NULL; 2666 if (fflagp != NULL) 2667 *fflagp = 0; 2668 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2669 return (error); 2670 if (fp->f_type != DTYPE_SOCKET) { 2671 error = ENOTSOCK; 2672 } else { 2673 *spp = fp->f_data; 2674 if (fflagp) 2675 *fflagp = fp->f_flag; 2676 SOCK_LOCK(*spp); 2677 soref(*spp); 2678 SOCK_UNLOCK(*spp); 2679 } 2680 fdrop(fp, td); 2681 2682 return (error); 2683} 2684 2685/* 2686 * Drop the reference count on the socket and XXX release the SX lock in the 2687 * future. The last reference closes the socket. 2688 * 2689 * Note: fputsock() is deprecated, see comment for fgetsock(). 2690 */ 2691void 2692fputsock(struct socket *so) 2693{ 2694 2695 ACCEPT_LOCK(); 2696 SOCK_LOCK(so); 2697 CURVNET_SET(so->so_vnet); 2698 sorele(so); 2699 CURVNET_RESTORE(); 2700} 2701 2702/* 2703 * Handle the last reference to a file being closed. 2704 */ 2705int 2706_fdrop(struct file *fp, struct thread *td) 2707{ 2708 int error; 2709 2710 error = 0; 2711 if (fp->f_count != 0) 2712 panic("fdrop: count %d", fp->f_count); 2713 if (fp->f_ops != &badfileops) 2714 error = fo_close(fp, td); 2715 atomic_subtract_int(&openfiles, 1); 2716 crfree(fp->f_cred); 2717 free(fp->f_advice, M_FADVISE); 2718 uma_zfree(file_zone, fp); 2719 2720 return (error); 2721} 2722 2723/* 2724 * Apply an advisory lock on a file descriptor. 2725 * 2726 * Just attempt to get a record lock of the requested type on the entire file 2727 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2728 */ 2729#ifndef _SYS_SYSPROTO_H_ 2730struct flock_args { 2731 int fd; 2732 int how; 2733}; 2734#endif 2735/* ARGSUSED */ 2736int 2737sys_flock(struct thread *td, struct flock_args *uap) 2738{ 2739 struct file *fp; 2740 struct vnode *vp; 2741 struct flock lf; 2742 cap_rights_t rights; 2743 int error; 2744 2745 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2746 if (error != 0) 2747 return (error); 2748 if (fp->f_type != DTYPE_VNODE) { 2749 fdrop(fp, td); 2750 return (EOPNOTSUPP); 2751 } 2752 2753 vp = fp->f_vnode; 2754 lf.l_whence = SEEK_SET; 2755 lf.l_start = 0; 2756 lf.l_len = 0; 2757 if (uap->how & LOCK_UN) { 2758 lf.l_type = F_UNLCK; 2759 atomic_clear_int(&fp->f_flag, FHASLOCK); 2760 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2761 goto done2; 2762 } 2763 if (uap->how & LOCK_EX) 2764 lf.l_type = F_WRLCK; 2765 else if (uap->how & LOCK_SH) 2766 lf.l_type = F_RDLCK; 2767 else { 2768 error = EBADF; 2769 goto done2; 2770 } 2771 atomic_set_int(&fp->f_flag, FHASLOCK); 2772 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2773 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2774done2: 2775 fdrop(fp, td); 2776 return (error); 2777} 2778/* 2779 * Duplicate the specified descriptor to a free descriptor. 2780 */ 2781int 2782dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2783 int openerror, int *indxp) 2784{ 2785 struct filedescent *newfde, *oldfde; 2786 struct file *fp; 2787 int error, indx; 2788 2789 KASSERT(openerror == ENODEV || openerror == ENXIO, 2790 ("unexpected error %d in %s", openerror, __func__)); 2791 2792 /* 2793 * If the to-be-dup'd fd number is greater than the allowed number 2794 * of file descriptors, or the fd to be dup'd has already been 2795 * closed, then reject. 2796 */ 2797 FILEDESC_XLOCK(fdp); 2798 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2799 FILEDESC_XUNLOCK(fdp); 2800 return (EBADF); 2801 } 2802 2803 error = fdalloc(td, 0, &indx); 2804 if (error != 0) { 2805 FILEDESC_XUNLOCK(fdp); 2806 return (error); 2807 } 2808 2809 /* 2810 * There are two cases of interest here. 2811 * 2812 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2813 * 2814 * For ENXIO steal away the file structure from (dfd) and store it in 2815 * (indx). (dfd) is effectively closed by this operation. 2816 */ 2817 switch (openerror) { 2818 case ENODEV: 2819 /* 2820 * Check that the mode the file is being opened for is a 2821 * subset of the mode of the existing descriptor. 2822 */ 2823 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2824 fdunused(fdp, indx); 2825 FILEDESC_XUNLOCK(fdp); 2826 return (EACCES); 2827 } 2828 fhold(fp); 2829 newfde = &fdp->fd_ofiles[indx]; 2830 oldfde = &fdp->fd_ofiles[dfd]; 2831#ifdef CAPABILITIES 2832 seq_write_begin(&newfde->fde_seq); 2833#endif 2834 memcpy(newfde, oldfde, fde_change_size); 2835 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2836#ifdef CAPABILITIES 2837 seq_write_end(&newfde->fde_seq); 2838#endif 2839 break; 2840 case ENXIO: 2841 /* 2842 * Steal away the file pointer from dfd and stuff it into indx. 2843 */ 2844 newfde = &fdp->fd_ofiles[indx]; 2845 oldfde = &fdp->fd_ofiles[dfd]; 2846#ifdef CAPABILITIES 2847 seq_write_begin(&newfde->fde_seq); 2848#endif 2849 memcpy(newfde, oldfde, fde_change_size); 2850 bzero(oldfde, fde_change_size); 2851 fdunused(fdp, dfd); 2852#ifdef CAPABILITIES 2853 seq_write_end(&newfde->fde_seq); 2854#endif 2855 break; 2856 } 2857 FILEDESC_XUNLOCK(fdp); 2858 *indxp = indx; 2859 return (0); 2860} 2861 2862/* 2863 * Scan all active processes and prisons to see if any of them have a current 2864 * or root directory of `olddp'. If so, replace them with the new mount point. 2865 */ 2866void 2867mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2868{ 2869 struct filedesc *fdp; 2870 struct prison *pr; 2871 struct proc *p; 2872 int nrele; 2873 2874 if (vrefcnt(olddp) == 1) 2875 return; 2876 nrele = 0; 2877 sx_slock(&allproc_lock); 2878 FOREACH_PROC_IN_SYSTEM(p) { 2879 fdp = fdhold(p); 2880 if (fdp == NULL) 2881 continue; 2882 FILEDESC_XLOCK(fdp); 2883 if (fdp->fd_cdir == olddp) { 2884 vref(newdp); 2885 fdp->fd_cdir = newdp; 2886 nrele++; 2887 } 2888 if (fdp->fd_rdir == olddp) { 2889 vref(newdp); 2890 fdp->fd_rdir = newdp; 2891 nrele++; 2892 } 2893 if (fdp->fd_jdir == olddp) { 2894 vref(newdp); 2895 fdp->fd_jdir = newdp; 2896 nrele++; 2897 } 2898 FILEDESC_XUNLOCK(fdp); 2899 fddrop(fdp); 2900 } 2901 sx_sunlock(&allproc_lock); 2902 if (rootvnode == olddp) { 2903 vref(newdp); 2904 rootvnode = newdp; 2905 nrele++; 2906 } 2907 mtx_lock(&prison0.pr_mtx); 2908 if (prison0.pr_root == olddp) { 2909 vref(newdp); 2910 prison0.pr_root = newdp; 2911 nrele++; 2912 } 2913 mtx_unlock(&prison0.pr_mtx); 2914 sx_slock(&allprison_lock); 2915 TAILQ_FOREACH(pr, &allprison, pr_list) { 2916 mtx_lock(&pr->pr_mtx); 2917 if (pr->pr_root == olddp) { 2918 vref(newdp); 2919 pr->pr_root = newdp; 2920 nrele++; 2921 } 2922 mtx_unlock(&pr->pr_mtx); 2923 } 2924 sx_sunlock(&allprison_lock); 2925 while (nrele--) 2926 vrele(olddp); 2927} 2928 2929struct filedesc_to_leader * 2930filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2931{ 2932 struct filedesc_to_leader *fdtol; 2933 2934 fdtol = malloc(sizeof(struct filedesc_to_leader), 2935 M_FILEDESC_TO_LEADER, M_WAITOK); 2936 fdtol->fdl_refcount = 1; 2937 fdtol->fdl_holdcount = 0; 2938 fdtol->fdl_wakeup = 0; 2939 fdtol->fdl_leader = leader; 2940 if (old != NULL) { 2941 FILEDESC_XLOCK(fdp); 2942 fdtol->fdl_next = old->fdl_next; 2943 fdtol->fdl_prev = old; 2944 old->fdl_next = fdtol; 2945 fdtol->fdl_next->fdl_prev = fdtol; 2946 FILEDESC_XUNLOCK(fdp); 2947 } else { 2948 fdtol->fdl_next = fdtol; 2949 fdtol->fdl_prev = fdtol; 2950 } 2951 return (fdtol); 2952} 2953 2954/* 2955 * Get file structures globally. 2956 */ 2957static int 2958sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2959{ 2960 struct xfile xf; 2961 struct filedesc *fdp; 2962 struct file *fp; 2963 struct proc *p; 2964 int error, n; 2965 2966 error = sysctl_wire_old_buffer(req, 0); 2967 if (error != 0) 2968 return (error); 2969 if (req->oldptr == NULL) { 2970 n = 0; 2971 sx_slock(&allproc_lock); 2972 FOREACH_PROC_IN_SYSTEM(p) { 2973 if (p->p_state == PRS_NEW) 2974 continue; 2975 fdp = fdhold(p); 2976 if (fdp == NULL) 2977 continue; 2978 /* overestimates sparse tables. */ 2979 if (fdp->fd_lastfile > 0) 2980 n += fdp->fd_lastfile; 2981 fddrop(fdp); 2982 } 2983 sx_sunlock(&allproc_lock); 2984 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2985 } 2986 error = 0; 2987 bzero(&xf, sizeof(xf)); 2988 xf.xf_size = sizeof(xf); 2989 sx_slock(&allproc_lock); 2990 FOREACH_PROC_IN_SYSTEM(p) { 2991 PROC_LOCK(p); 2992 if (p->p_state == PRS_NEW) { 2993 PROC_UNLOCK(p); 2994 continue; 2995 } 2996 if (p_cansee(req->td, p) != 0) { 2997 PROC_UNLOCK(p); 2998 continue; 2999 } 3000 xf.xf_pid = p->p_pid; 3001 xf.xf_uid = p->p_ucred->cr_uid; 3002 PROC_UNLOCK(p); 3003 fdp = fdhold(p); 3004 if (fdp == NULL) 3005 continue; 3006 FILEDESC_SLOCK(fdp); 3007 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3008 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3009 continue; 3010 xf.xf_fd = n; 3011 xf.xf_file = fp; 3012 xf.xf_data = fp->f_data; 3013 xf.xf_vnode = fp->f_vnode; 3014 xf.xf_type = fp->f_type; 3015 xf.xf_count = fp->f_count; 3016 xf.xf_msgcount = 0; 3017 xf.xf_offset = foffset_get(fp); 3018 xf.xf_flag = fp->f_flag; 3019 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3020 if (error) 3021 break; 3022 } 3023 FILEDESC_SUNLOCK(fdp); 3024 fddrop(fdp); 3025 if (error) 3026 break; 3027 } 3028 sx_sunlock(&allproc_lock); 3029 return (error); 3030} 3031 3032SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3033 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3034 3035#ifdef KINFO_OFILE_SIZE 3036CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3037#endif 3038 3039#ifdef COMPAT_FREEBSD7 3040static int 3041export_vnode_for_osysctl(struct vnode *vp, int type, 3042 struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req) 3043{ 3044 int error; 3045 char *fullpath, *freepath; 3046 3047 bzero(kif, sizeof(*kif)); 3048 kif->kf_structsize = sizeof(*kif); 3049 3050 vref(vp); 3051 kif->kf_fd = type; 3052 kif->kf_type = KF_TYPE_VNODE; 3053 /* This function only handles directories. */ 3054 if (vp->v_type != VDIR) { 3055 vrele(vp); 3056 return (ENOTDIR); 3057 } 3058 kif->kf_vnode_type = KF_VTYPE_VDIR; 3059 3060 /* 3061 * This is not a true file descriptor, so we set a bogus refcount 3062 * and offset to indicate these fields should be ignored. 3063 */ 3064 kif->kf_ref_count = -1; 3065 kif->kf_offset = -1; 3066 3067 freepath = NULL; 3068 fullpath = "-"; 3069 FILEDESC_SUNLOCK(fdp); 3070 vn_fullpath(curthread, vp, &fullpath, &freepath); 3071 vrele(vp); 3072 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 3073 if (freepath != NULL) 3074 free(freepath, M_TEMP); 3075 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 3076 FILEDESC_SLOCK(fdp); 3077 return (error); 3078} 3079 3080/* 3081 * Get per-process file descriptors for use by procstat(1), et al. 3082 */ 3083static int 3084sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3085{ 3086 char *fullpath, *freepath; 3087 struct kinfo_ofile *kif; 3088 struct filedesc *fdp; 3089 int error, i, *name; 3090 struct shmfd *shmfd; 3091 struct socket *so; 3092 struct vnode *vp; 3093 struct ksem *ks; 3094 struct file *fp; 3095 struct proc *p; 3096 struct tty *tp; 3097 3098 name = (int *)arg1; 3099 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3100 if (error != 0) 3101 return (error); 3102 fdp = fdhold(p); 3103 PROC_UNLOCK(p); 3104 if (fdp == NULL) 3105 return (ENOENT); 3106 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3107 FILEDESC_SLOCK(fdp); 3108 if (fdp->fd_cdir != NULL) 3109 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3110 fdp, req); 3111 if (fdp->fd_rdir != NULL) 3112 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3113 fdp, req); 3114 if (fdp->fd_jdir != NULL) 3115 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3116 fdp, req); 3117 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3118 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3119 continue; 3120 bzero(kif, sizeof(*kif)); 3121 kif->kf_structsize = sizeof(*kif); 3122 ks = NULL; 3123 vp = NULL; 3124 so = NULL; 3125 tp = NULL; 3126 shmfd = NULL; 3127 kif->kf_fd = i; 3128 3129 switch (fp->f_type) { 3130 case DTYPE_VNODE: 3131 kif->kf_type = KF_TYPE_VNODE; 3132 vp = fp->f_vnode; 3133 break; 3134 3135 case DTYPE_SOCKET: 3136 kif->kf_type = KF_TYPE_SOCKET; 3137 so = fp->f_data; 3138 break; 3139 3140 case DTYPE_PIPE: 3141 kif->kf_type = KF_TYPE_PIPE; 3142 break; 3143 3144 case DTYPE_FIFO: 3145 kif->kf_type = KF_TYPE_FIFO; 3146 vp = fp->f_vnode; 3147 break; 3148 3149 case DTYPE_KQUEUE: 3150 kif->kf_type = KF_TYPE_KQUEUE; 3151 break; 3152 3153 case DTYPE_CRYPTO: 3154 kif->kf_type = KF_TYPE_CRYPTO; 3155 break; 3156 3157 case DTYPE_MQUEUE: 3158 kif->kf_type = KF_TYPE_MQUEUE; 3159 break; 3160 3161 case DTYPE_SHM: 3162 kif->kf_type = KF_TYPE_SHM; 3163 shmfd = fp->f_data; 3164 break; 3165 3166 case DTYPE_SEM: 3167 kif->kf_type = KF_TYPE_SEM; 3168 ks = fp->f_data; 3169 break; 3170 3171 case DTYPE_PTS: 3172 kif->kf_type = KF_TYPE_PTS; 3173 tp = fp->f_data; 3174 break; 3175 3176#ifdef PROCDESC 3177 case DTYPE_PROCDESC: 3178 kif->kf_type = KF_TYPE_PROCDESC; 3179 break; 3180#endif 3181 3182 default: 3183 kif->kf_type = KF_TYPE_UNKNOWN; 3184 break; 3185 } 3186 kif->kf_ref_count = fp->f_count; 3187 if (fp->f_flag & FREAD) 3188 kif->kf_flags |= KF_FLAG_READ; 3189 if (fp->f_flag & FWRITE) 3190 kif->kf_flags |= KF_FLAG_WRITE; 3191 if (fp->f_flag & FAPPEND) 3192 kif->kf_flags |= KF_FLAG_APPEND; 3193 if (fp->f_flag & FASYNC) 3194 kif->kf_flags |= KF_FLAG_ASYNC; 3195 if (fp->f_flag & FFSYNC) 3196 kif->kf_flags |= KF_FLAG_FSYNC; 3197 if (fp->f_flag & FNONBLOCK) 3198 kif->kf_flags |= KF_FLAG_NONBLOCK; 3199 if (fp->f_flag & O_DIRECT) 3200 kif->kf_flags |= KF_FLAG_DIRECT; 3201 if (fp->f_flag & FHASLOCK) 3202 kif->kf_flags |= KF_FLAG_HASLOCK; 3203 kif->kf_offset = foffset_get(fp); 3204 if (vp != NULL) { 3205 vref(vp); 3206 switch (vp->v_type) { 3207 case VNON: 3208 kif->kf_vnode_type = KF_VTYPE_VNON; 3209 break; 3210 case VREG: 3211 kif->kf_vnode_type = KF_VTYPE_VREG; 3212 break; 3213 case VDIR: 3214 kif->kf_vnode_type = KF_VTYPE_VDIR; 3215 break; 3216 case VBLK: 3217 kif->kf_vnode_type = KF_VTYPE_VBLK; 3218 break; 3219 case VCHR: 3220 kif->kf_vnode_type = KF_VTYPE_VCHR; 3221 break; 3222 case VLNK: 3223 kif->kf_vnode_type = KF_VTYPE_VLNK; 3224 break; 3225 case VSOCK: 3226 kif->kf_vnode_type = KF_VTYPE_VSOCK; 3227 break; 3228 case VFIFO: 3229 kif->kf_vnode_type = KF_VTYPE_VFIFO; 3230 break; 3231 case VBAD: 3232 kif->kf_vnode_type = KF_VTYPE_VBAD; 3233 break; 3234 default: 3235 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 3236 break; 3237 } 3238 /* 3239 * It is OK to drop the filedesc lock here as we will 3240 * re-validate and re-evaluate its properties when 3241 * the loop continues. 3242 */ 3243 freepath = NULL; 3244 fullpath = "-"; 3245 FILEDESC_SUNLOCK(fdp); 3246 vn_fullpath(curthread, vp, &fullpath, &freepath); 3247 vrele(vp); 3248 strlcpy(kif->kf_path, fullpath, 3249 sizeof(kif->kf_path)); 3250 if (freepath != NULL) 3251 free(freepath, M_TEMP); 3252 FILEDESC_SLOCK(fdp); 3253 } 3254 if (so != NULL) { 3255 struct sockaddr *sa; 3256 3257 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 3258 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 3259 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 3260 free(sa, M_SONAME); 3261 } 3262 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 3263 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 3264 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 3265 free(sa, M_SONAME); 3266 } 3267 kif->kf_sock_domain = 3268 so->so_proto->pr_domain->dom_family; 3269 kif->kf_sock_type = so->so_type; 3270 kif->kf_sock_protocol = so->so_proto->pr_protocol; 3271 } 3272 if (tp != NULL) { 3273 strlcpy(kif->kf_path, tty_devname(tp), 3274 sizeof(kif->kf_path)); 3275 } 3276 if (shmfd != NULL) 3277 shm_path(shmfd, kif->kf_path, sizeof(kif->kf_path)); 3278 if (ks != NULL && ksem_info != NULL) 3279 ksem_info(ks, kif->kf_path, sizeof(kif->kf_path), NULL); 3280 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 3281 if (error) 3282 break; 3283 } 3284 FILEDESC_SUNLOCK(fdp); 3285 fddrop(fdp); 3286 free(kif, M_TEMP); 3287 return (0); 3288} 3289 3290static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3291 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3292 "Process ofiledesc entries"); 3293#endif /* COMPAT_FREEBSD7 */ 3294 3295#ifdef KINFO_FILE_SIZE 3296CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3297#endif 3298 3299struct export_fd_buf { 3300 struct filedesc *fdp; 3301 struct sbuf *sb; 3302 ssize_t remainder; 3303 struct kinfo_file kif; 3304 int flags; 3305}; 3306 3307static int 3308export_fd_to_sb(void *data, int type, int fd, int fflags, int refcnt, 3309 int64_t offset, cap_rights_t *rightsp, struct export_fd_buf *efbuf) 3310{ 3311 struct { 3312 int fflag; 3313 int kf_fflag; 3314 } fflags_table[] = { 3315 { FAPPEND, KF_FLAG_APPEND }, 3316 { FASYNC, KF_FLAG_ASYNC }, 3317 { FFSYNC, KF_FLAG_FSYNC }, 3318 { FHASLOCK, KF_FLAG_HASLOCK }, 3319 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3320 { FREAD, KF_FLAG_READ }, 3321 { FWRITE, KF_FLAG_WRITE }, 3322 { O_CREAT, KF_FLAG_CREAT }, 3323 { O_DIRECT, KF_FLAG_DIRECT }, 3324 { O_EXCL, KF_FLAG_EXCL }, 3325 { O_EXEC, KF_FLAG_EXEC }, 3326 { O_EXLOCK, KF_FLAG_EXLOCK }, 3327 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3328 { O_SHLOCK, KF_FLAG_SHLOCK }, 3329 { O_TRUNC, KF_FLAG_TRUNC } 3330 }; 3331#define NFFLAGS (sizeof(fflags_table) / sizeof(*fflags_table)) 3332 struct kinfo_file *kif; 3333 struct vnode *vp; 3334 int error, locked; 3335 unsigned int i; 3336 3337 if (efbuf->remainder == 0) 3338 return (0); 3339 kif = &efbuf->kif; 3340 bzero(kif, sizeof(*kif)); 3341 locked = efbuf->fdp != NULL; 3342 switch (type) { 3343 case KF_TYPE_FIFO: 3344 case KF_TYPE_VNODE: 3345 if (locked) { 3346 FILEDESC_SUNLOCK(efbuf->fdp); 3347 locked = 0; 3348 } 3349 vp = (struct vnode *)data; 3350 error = fill_vnode_info(vp, kif); 3351 vrele(vp); 3352 break; 3353 case KF_TYPE_SOCKET: 3354 error = fill_socket_info((struct socket *)data, kif); 3355 break; 3356 case KF_TYPE_PIPE: 3357 error = fill_pipe_info((struct pipe *)data, kif); 3358 break; 3359 case KF_TYPE_PTS: 3360 error = fill_pts_info((struct tty *)data, kif); 3361 break; 3362 case KF_TYPE_PROCDESC: 3363 error = fill_procdesc_info((struct procdesc *)data, kif); 3364 break; 3365 case KF_TYPE_SEM: 3366 error = fill_sem_info((struct file *)data, kif); 3367 break; 3368 case KF_TYPE_SHM: 3369 error = fill_shm_info((struct file *)data, kif); 3370 break; 3371 default: 3372 error = 0; 3373 } 3374 if (error == 0) 3375 kif->kf_status |= KF_ATTR_VALID; 3376 3377 /* 3378 * Translate file access flags. 3379 */ 3380 for (i = 0; i < NFFLAGS; i++) 3381 if (fflags & fflags_table[i].fflag) 3382 kif->kf_flags |= fflags_table[i].kf_fflag; 3383 if (rightsp != NULL) 3384 kif->kf_cap_rights = *rightsp; 3385 else 3386 cap_rights_init(&kif->kf_cap_rights); 3387 kif->kf_fd = fd; 3388 kif->kf_type = type; 3389 kif->kf_ref_count = refcnt; 3390 kif->kf_offset = offset; 3391 if ((efbuf->flags & KERN_FILEDESC_PACK_KINFO) != 0) 3392 /* Pack record size down */ 3393 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3394 strlen(kif->kf_path) + 1; 3395 else 3396 kif->kf_structsize = sizeof(*kif); 3397 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3398 if (efbuf->remainder != -1) { 3399 if (efbuf->remainder < kif->kf_structsize) { 3400 /* Terminate export. */ 3401 efbuf->remainder = 0; 3402 if (efbuf->fdp != NULL && !locked) 3403 FILEDESC_SLOCK(efbuf->fdp); 3404 return (0); 3405 } 3406 efbuf->remainder -= kif->kf_structsize; 3407 } 3408 if (locked) 3409 FILEDESC_SUNLOCK(efbuf->fdp); 3410 error = sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM; 3411 if (efbuf->fdp != NULL) 3412 FILEDESC_SLOCK(efbuf->fdp); 3413 return (error); 3414} 3415 3416/* 3417 * Store a process file descriptor information to sbuf. 3418 * 3419 * Takes a locked proc as argument, and returns with the proc unlocked. 3420 */ 3421int 3422kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3423 int flags) 3424{ 3425 struct file *fp; 3426 struct filedesc *fdp; 3427 struct export_fd_buf *efbuf; 3428 struct vnode *cttyvp, *textvp, *tracevp; 3429 int64_t offset; 3430 void *data; 3431 int error, i; 3432 int type, refcnt, fflags; 3433 cap_rights_t rights; 3434 3435 PROC_LOCK_ASSERT(p, MA_OWNED); 3436 3437 /* ktrace vnode */ 3438 tracevp = p->p_tracevp; 3439 if (tracevp != NULL) 3440 vref(tracevp); 3441 /* text vnode */ 3442 textvp = p->p_textvp; 3443 if (textvp != NULL) 3444 vref(textvp); 3445 /* Controlling tty. */ 3446 cttyvp = NULL; 3447 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3448 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3449 if (cttyvp != NULL) 3450 vref(cttyvp); 3451 } 3452 fdp = fdhold(p); 3453 PROC_UNLOCK(p); 3454 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3455 efbuf->fdp = NULL; 3456 efbuf->sb = sb; 3457 efbuf->remainder = maxlen; 3458 efbuf->flags = flags; 3459 if (tracevp != NULL) 3460 export_fd_to_sb(tracevp, KF_TYPE_VNODE, KF_FD_TYPE_TRACE, 3461 FREAD | FWRITE, -1, -1, NULL, efbuf); 3462 if (textvp != NULL) 3463 export_fd_to_sb(textvp, KF_TYPE_VNODE, KF_FD_TYPE_TEXT, 3464 FREAD, -1, -1, NULL, efbuf); 3465 if (cttyvp != NULL) 3466 export_fd_to_sb(cttyvp, KF_TYPE_VNODE, KF_FD_TYPE_CTTY, 3467 FREAD | FWRITE, -1, -1, NULL, efbuf); 3468 error = 0; 3469 if (fdp == NULL) 3470 goto fail; 3471 efbuf->fdp = fdp; 3472 FILEDESC_SLOCK(fdp); 3473 /* working directory */ 3474 if (fdp->fd_cdir != NULL) { 3475 vref(fdp->fd_cdir); 3476 data = fdp->fd_cdir; 3477 export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_CWD, 3478 FREAD, -1, -1, NULL, efbuf); 3479 } 3480 /* root directory */ 3481 if (fdp->fd_rdir != NULL) { 3482 vref(fdp->fd_rdir); 3483 data = fdp->fd_rdir; 3484 export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_ROOT, 3485 FREAD, -1, -1, NULL, efbuf); 3486 } 3487 /* jail directory */ 3488 if (fdp->fd_jdir != NULL) { 3489 vref(fdp->fd_jdir); 3490 data = fdp->fd_jdir; 3491 export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_JAIL, 3492 FREAD, -1, -1, NULL, efbuf); 3493 } 3494 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3495 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3496 continue; 3497 data = NULL; 3498#ifdef CAPABILITIES 3499 rights = *cap_rights(fdp, i); 3500#else /* !CAPABILITIES */ 3501 cap_rights_init(&rights); 3502#endif 3503 switch (fp->f_type) { 3504 case DTYPE_VNODE: 3505 type = KF_TYPE_VNODE; 3506 vref(fp->f_vnode); 3507 data = fp->f_vnode; 3508 break; 3509 3510 case DTYPE_SOCKET: 3511 type = KF_TYPE_SOCKET; 3512 data = fp->f_data; 3513 break; 3514 3515 case DTYPE_PIPE: 3516 type = KF_TYPE_PIPE; 3517 data = fp->f_data; 3518 break; 3519 3520 case DTYPE_FIFO: 3521 type = KF_TYPE_FIFO; 3522 vref(fp->f_vnode); 3523 data = fp->f_vnode; 3524 break; 3525 3526 case DTYPE_KQUEUE: 3527 type = KF_TYPE_KQUEUE; 3528 break; 3529 3530 case DTYPE_CRYPTO: 3531 type = KF_TYPE_CRYPTO; 3532 break; 3533 3534 case DTYPE_MQUEUE: 3535 type = KF_TYPE_MQUEUE; 3536 break; 3537 3538 case DTYPE_SHM: 3539 type = KF_TYPE_SHM; 3540 data = fp; 3541 break; 3542 3543 case DTYPE_SEM: 3544 type = KF_TYPE_SEM; 3545 data = fp; 3546 break; 3547 3548 case DTYPE_PTS: 3549 type = KF_TYPE_PTS; 3550 data = fp->f_data; 3551 break; 3552 3553#ifdef PROCDESC 3554 case DTYPE_PROCDESC: 3555 type = KF_TYPE_PROCDESC; 3556 data = fp->f_data; 3557 break; 3558#endif 3559 3560 default: 3561 type = KF_TYPE_UNKNOWN; 3562 break; 3563 } 3564 refcnt = fp->f_count; 3565 fflags = fp->f_flag; 3566 offset = foffset_get(fp); 3567 3568 /* 3569 * Create sysctl entry. 3570 * It is OK to drop the filedesc lock here as we will 3571 * re-validate and re-evaluate its properties when 3572 * the loop continues. 3573 */ 3574 error = export_fd_to_sb(data, type, i, fflags, refcnt, 3575 offset, &rights, efbuf); 3576 if (error != 0) 3577 break; 3578 } 3579 FILEDESC_SUNLOCK(fdp); 3580 fddrop(fdp); 3581fail: 3582 free(efbuf, M_TEMP); 3583 return (error); 3584} 3585 3586#define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3587 3588/* 3589 * Get per-process file descriptors for use by procstat(1), et al. 3590 */ 3591static int 3592sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3593{ 3594 struct sbuf sb; 3595 struct proc *p; 3596 ssize_t maxlen; 3597 int error, error2, *name; 3598 3599 name = (int *)arg1; 3600 3601 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3602 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3603 if (error != 0) { 3604 sbuf_delete(&sb); 3605 return (error); 3606 } 3607 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3608 error = kern_proc_filedesc_out(p, &sb, maxlen, 3609 KERN_FILEDESC_PACK_KINFO); 3610 error2 = sbuf_finish(&sb); 3611 sbuf_delete(&sb); 3612 return (error != 0 ? error : error2); 3613} 3614 3615int 3616vntype_to_kinfo(int vtype) 3617{ 3618 struct { 3619 int vtype; 3620 int kf_vtype; 3621 } vtypes_table[] = { 3622 { VBAD, KF_VTYPE_VBAD }, 3623 { VBLK, KF_VTYPE_VBLK }, 3624 { VCHR, KF_VTYPE_VCHR }, 3625 { VDIR, KF_VTYPE_VDIR }, 3626 { VFIFO, KF_VTYPE_VFIFO }, 3627 { VLNK, KF_VTYPE_VLNK }, 3628 { VNON, KF_VTYPE_VNON }, 3629 { VREG, KF_VTYPE_VREG }, 3630 { VSOCK, KF_VTYPE_VSOCK } 3631 }; 3632#define NVTYPES (sizeof(vtypes_table) / sizeof(*vtypes_table)) 3633 unsigned int i; 3634 3635 /* 3636 * Perform vtype translation. 3637 */ 3638 for (i = 0; i < NVTYPES; i++) 3639 if (vtypes_table[i].vtype == vtype) 3640 break; 3641 if (i < NVTYPES) 3642 return (vtypes_table[i].kf_vtype); 3643 3644 return (KF_VTYPE_UNKNOWN); 3645} 3646 3647static inline void 3648vn_fill_junk(struct kinfo_file *kif) 3649{ 3650 size_t len, olen; 3651 3652 /* 3653 * Simulate vn_fullpath returning changing values for a given 3654 * vp during e.g. coredump. 3655 */ 3656 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 3657 olen = strlen(kif->kf_path); 3658 if (len < olen) 3659 strcpy(&kif->kf_path[len - 1], "$"); 3660 else 3661 for (; olen < len; olen++) 3662 strcpy(&kif->kf_path[olen], "A"); 3663} 3664 3665static int 3666fill_vnode_info(struct vnode *vp, struct kinfo_file *kif) 3667{ 3668 struct vattr va; 3669 char *fullpath, *freepath; 3670 int error; 3671 3672 if (vp == NULL) 3673 return (1); 3674 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 3675 freepath = NULL; 3676 fullpath = "-"; 3677 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 3678 if (error == 0) { 3679 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 3680 } 3681 if (freepath != NULL) 3682 free(freepath, M_TEMP); 3683 3684 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 3685 vn_fill_junk(kif); 3686 ); 3687 3688 /* 3689 * Retrieve vnode attributes. 3690 */ 3691 va.va_fsid = VNOVAL; 3692 va.va_rdev = NODEV; 3693 vn_lock(vp, LK_SHARED | LK_RETRY); 3694 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 3695 VOP_UNLOCK(vp, 0); 3696 if (error != 0) 3697 return (error); 3698 if (va.va_fsid != VNOVAL) 3699 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 3700 else 3701 kif->kf_un.kf_file.kf_file_fsid = 3702 vp->v_mount->mnt_stat.f_fsid.val[0]; 3703 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 3704 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 3705 kif->kf_un.kf_file.kf_file_size = va.va_size; 3706 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 3707 return (0); 3708} 3709 3710static int 3711fill_socket_info(struct socket *so, struct kinfo_file *kif) 3712{ 3713 struct sockaddr *sa; 3714 struct inpcb *inpcb; 3715 struct unpcb *unpcb; 3716 int error; 3717 3718 if (so == NULL) 3719 return (1); 3720 kif->kf_sock_domain = so->so_proto->pr_domain->dom_family; 3721 kif->kf_sock_type = so->so_type; 3722 kif->kf_sock_protocol = so->so_proto->pr_protocol; 3723 kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb; 3724 switch(kif->kf_sock_domain) { 3725 case AF_INET: 3726 case AF_INET6: 3727 if (kif->kf_sock_protocol == IPPROTO_TCP) { 3728 if (so->so_pcb != NULL) { 3729 inpcb = (struct inpcb *)(so->so_pcb); 3730 kif->kf_un.kf_sock.kf_sock_inpcb = 3731 (uintptr_t)inpcb->inp_ppcb; 3732 } 3733 } 3734 break; 3735 case AF_UNIX: 3736 if (so->so_pcb != NULL) { 3737 unpcb = (struct unpcb *)(so->so_pcb); 3738 if (unpcb->unp_conn) { 3739 kif->kf_un.kf_sock.kf_sock_unpconn = 3740 (uintptr_t)unpcb->unp_conn; 3741 kif->kf_un.kf_sock.kf_sock_rcv_sb_state = 3742 so->so_rcv.sb_state; 3743 kif->kf_un.kf_sock.kf_sock_snd_sb_state = 3744 so->so_snd.sb_state; 3745 } 3746 } 3747 break; 3748 } 3749 error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa); 3750 if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 3751 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 3752 free(sa, M_SONAME); 3753 } 3754 error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa); 3755 if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 3756 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 3757 free(sa, M_SONAME); 3758 } 3759 strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name, 3760 sizeof(kif->kf_path)); 3761 return (0); 3762} 3763 3764static int 3765fill_pts_info(struct tty *tp, struct kinfo_file *kif) 3766{ 3767 3768 if (tp == NULL) 3769 return (1); 3770 kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp); 3771 strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path)); 3772 return (0); 3773} 3774 3775static int 3776fill_pipe_info(struct pipe *pi, struct kinfo_file *kif) 3777{ 3778 3779 if (pi == NULL) 3780 return (1); 3781 kif->kf_un.kf_pipe.kf_pipe_addr = (uintptr_t)pi; 3782 kif->kf_un.kf_pipe.kf_pipe_peer = (uintptr_t)pi->pipe_peer; 3783 kif->kf_un.kf_pipe.kf_pipe_buffer_cnt = pi->pipe_buffer.cnt; 3784 return (0); 3785} 3786 3787static int 3788fill_procdesc_info(struct procdesc *pdp, struct kinfo_file *kif) 3789{ 3790 3791 if (pdp == NULL) 3792 return (1); 3793 kif->kf_un.kf_proc.kf_pid = pdp->pd_pid; 3794 return (0); 3795} 3796 3797static int 3798fill_sem_info(struct file *fp, struct kinfo_file *kif) 3799{ 3800 struct thread *td; 3801 struct stat sb; 3802 3803 td = curthread; 3804 if (fp->f_data == NULL) 3805 return (1); 3806 if (fo_stat(fp, &sb, td->td_ucred, td) != 0) 3807 return (1); 3808 if (ksem_info == NULL) 3809 return (1); 3810 ksem_info(fp->f_data, kif->kf_path, sizeof(kif->kf_path), 3811 &kif->kf_un.kf_sem.kf_sem_value); 3812 kif->kf_un.kf_sem.kf_sem_mode = sb.st_mode; 3813 return (0); 3814} 3815 3816static int 3817fill_shm_info(struct file *fp, struct kinfo_file *kif) 3818{ 3819 struct thread *td; 3820 struct stat sb; 3821 3822 td = curthread; 3823 if (fp->f_data == NULL) 3824 return (1); 3825 if (fo_stat(fp, &sb, td->td_ucred, td) != 0) 3826 return (1); 3827 shm_path(fp->f_data, kif->kf_path, sizeof(kif->kf_path)); 3828 kif->kf_un.kf_file.kf_file_mode = sb.st_mode; 3829 kif->kf_un.kf_file.kf_file_size = sb.st_size; 3830 return (0); 3831} 3832 3833static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3834 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3835 "Process filedesc entries"); 3836 3837#ifdef DDB 3838/* 3839 * For the purposes of debugging, generate a human-readable string for the 3840 * file type. 3841 */ 3842static const char * 3843file_type_to_name(short type) 3844{ 3845 3846 switch (type) { 3847 case 0: 3848 return ("zero"); 3849 case DTYPE_VNODE: 3850 return ("vnod"); 3851 case DTYPE_SOCKET: 3852 return ("sock"); 3853 case DTYPE_PIPE: 3854 return ("pipe"); 3855 case DTYPE_FIFO: 3856 return ("fifo"); 3857 case DTYPE_KQUEUE: 3858 return ("kque"); 3859 case DTYPE_CRYPTO: 3860 return ("crpt"); 3861 case DTYPE_MQUEUE: 3862 return ("mque"); 3863 case DTYPE_SHM: 3864 return ("shm"); 3865 case DTYPE_SEM: 3866 return ("ksem"); 3867 default: 3868 return ("unkn"); 3869 } 3870} 3871 3872/* 3873 * For the purposes of debugging, identify a process (if any, perhaps one of 3874 * many) that references the passed file in its file descriptor array. Return 3875 * NULL if none. 3876 */ 3877static struct proc * 3878file_to_first_proc(struct file *fp) 3879{ 3880 struct filedesc *fdp; 3881 struct proc *p; 3882 int n; 3883 3884 FOREACH_PROC_IN_SYSTEM(p) { 3885 if (p->p_state == PRS_NEW) 3886 continue; 3887 fdp = p->p_fd; 3888 if (fdp == NULL) 3889 continue; 3890 for (n = 0; n <= fdp->fd_lastfile; n++) { 3891 if (fp == fdp->fd_ofiles[n].fde_file) 3892 return (p); 3893 } 3894 } 3895 return (NULL); 3896} 3897 3898static void 3899db_print_file(struct file *fp, int header) 3900{ 3901 struct proc *p; 3902 3903 if (header) 3904 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3905 "File", "Type", "Data", "Flag", "GCFl", "Count", 3906 "MCount", "Vnode", "FPID", "FCmd"); 3907 p = file_to_first_proc(fp); 3908 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3909 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3910 0, fp->f_count, 0, fp->f_vnode, 3911 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3912} 3913 3914DB_SHOW_COMMAND(file, db_show_file) 3915{ 3916 struct file *fp; 3917 3918 if (!have_addr) { 3919 db_printf("usage: show file <addr>\n"); 3920 return; 3921 } 3922 fp = (struct file *)addr; 3923 db_print_file(fp, 1); 3924} 3925 3926DB_SHOW_COMMAND(files, db_show_files) 3927{ 3928 struct filedesc *fdp; 3929 struct file *fp; 3930 struct proc *p; 3931 int header; 3932 int n; 3933 3934 header = 1; 3935 FOREACH_PROC_IN_SYSTEM(p) { 3936 if (p->p_state == PRS_NEW) 3937 continue; 3938 if ((fdp = p->p_fd) == NULL) 3939 continue; 3940 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3941 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3942 continue; 3943 db_print_file(fp, header); 3944 header = 0; 3945 } 3946 } 3947} 3948#endif 3949 3950SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3951 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3952 3953SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3954 &maxfiles, 0, "Maximum number of files"); 3955 3956SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3957 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3958 3959/* ARGSUSED*/ 3960static void 3961filelistinit(void *dummy) 3962{ 3963 3964 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3965 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3966 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3967 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3968} 3969SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3970 3971/*-------------------------------------------------------------------*/ 3972 3973static int 3974badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3975 int flags, struct thread *td) 3976{ 3977 3978 return (EBADF); 3979} 3980 3981static int 3982badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3983 struct thread *td) 3984{ 3985 3986 return (EINVAL); 3987} 3988 3989static int 3990badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3991 struct thread *td) 3992{ 3993 3994 return (EBADF); 3995} 3996 3997static int 3998badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3999 struct thread *td) 4000{ 4001 4002 return (0); 4003} 4004 4005static int 4006badfo_kqfilter(struct file *fp, struct knote *kn) 4007{ 4008 4009 return (EBADF); 4010} 4011 4012static int 4013badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4014 struct thread *td) 4015{ 4016 4017 return (EBADF); 4018} 4019 4020static int 4021badfo_close(struct file *fp, struct thread *td) 4022{ 4023 4024 return (EBADF); 4025} 4026 4027static int 4028badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4029 struct thread *td) 4030{ 4031 4032 return (EBADF); 4033} 4034 4035static int 4036badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4037 struct thread *td) 4038{ 4039 4040 return (EBADF); 4041} 4042 4043static int 4044badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4045 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4046 int kflags, struct thread *td) 4047{ 4048 4049 return (EBADF); 4050} 4051 4052struct fileops badfileops = { 4053 .fo_read = badfo_readwrite, 4054 .fo_write = badfo_readwrite, 4055 .fo_truncate = badfo_truncate, 4056 .fo_ioctl = badfo_ioctl, 4057 .fo_poll = badfo_poll, 4058 .fo_kqfilter = badfo_kqfilter, 4059 .fo_stat = badfo_stat, 4060 .fo_close = badfo_close, 4061 .fo_chmod = badfo_chmod, 4062 .fo_chown = badfo_chown, 4063 .fo_sendfile = badfo_sendfile, 4064}; 4065 4066int 4067invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4068 struct thread *td) 4069{ 4070 4071 return (EINVAL); 4072} 4073 4074int 4075invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4076 struct thread *td) 4077{ 4078 4079 return (EINVAL); 4080} 4081 4082int 4083invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4084 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4085 int kflags, struct thread *td) 4086{ 4087 4088 return (EINVAL); 4089} 4090 4091/*-------------------------------------------------------------------*/ 4092 4093/* 4094 * File Descriptor pseudo-device driver (/dev/fd/). 4095 * 4096 * Opening minor device N dup()s the file (if any) connected to file 4097 * descriptor N belonging to the calling process. Note that this driver 4098 * consists of only the ``open()'' routine, because all subsequent 4099 * references to this file will be direct to the other driver. 4100 * 4101 * XXX: we could give this one a cloning event handler if necessary. 4102 */ 4103 4104/* ARGSUSED */ 4105static int 4106fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4107{ 4108 4109 /* 4110 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4111 * the file descriptor being sought for duplication. The error 4112 * return ensures that the vnode for this device will be released 4113 * by vn_open. Open will detect this special error and take the 4114 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4115 * will simply report the error. 4116 */ 4117 td->td_dupfd = dev2unit(dev); 4118 return (ENODEV); 4119} 4120 4121static struct cdevsw fildesc_cdevsw = { 4122 .d_version = D_VERSION, 4123 .d_open = fdopen, 4124 .d_name = "FD", 4125}; 4126 4127static void 4128fildesc_drvinit(void *unused) 4129{ 4130 struct cdev *dev; 4131 4132 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4133 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4134 make_dev_alias(dev, "stdin"); 4135 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4136 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4137 make_dev_alias(dev, "stdout"); 4138 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4139 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4140 make_dev_alias(dev, "stderr"); 4141} 4142 4143SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4144