kern_descrip.c revision 315372
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/11/sys/kern/kern_descrip.c 315372 2017-03-16 06:03:27Z mjg $"); 39 40#include "opt_capsicum.h" 41#include "opt_compat.h" 42#include "opt_ddb.h" 43#include "opt_ktrace.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47 48#include <sys/capsicum.h> 49#include <sys/conf.h> 50#include <sys/fcntl.h> 51#include <sys/file.h> 52#include <sys/filedesc.h> 53#include <sys/filio.h> 54#include <sys/jail.h> 55#include <sys/kernel.h> 56#include <sys/limits.h> 57#include <sys/lock.h> 58#include <sys/malloc.h> 59#include <sys/mount.h> 60#include <sys/mutex.h> 61#include <sys/namei.h> 62#include <sys/selinfo.h> 63#include <sys/priv.h> 64#include <sys/proc.h> 65#include <sys/protosw.h> 66#include <sys/racct.h> 67#include <sys/resourcevar.h> 68#include <sys/sbuf.h> 69#include <sys/signalvar.h> 70#include <sys/kdb.h> 71#include <sys/stat.h> 72#include <sys/sx.h> 73#include <sys/syscallsubr.h> 74#include <sys/sysctl.h> 75#include <sys/sysproto.h> 76#include <sys/unistd.h> 77#include <sys/user.h> 78#include <sys/vnode.h> 79#ifdef KTRACE 80#include <sys/ktrace.h> 81#endif 82 83#include <net/vnet.h> 84 85#include <security/audit/audit.h> 86 87#include <vm/uma.h> 88#include <vm/vm.h> 89 90#include <ddb/ddb.h> 91 92static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 93static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 94 "file desc to leader structures"); 95static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 96MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 97 98MALLOC_DECLARE(M_FADVISE); 99 100static uma_zone_t file_zone; 101static uma_zone_t filedesc0_zone; 102 103static int closefp(struct filedesc *fdp, int fd, struct file *fp, 104 struct thread *td, int holdleaders); 105static int fd_first_free(struct filedesc *fdp, int low, int size); 106static int fd_last_used(struct filedesc *fdp, int size); 107static void fdgrowtable(struct filedesc *fdp, int nfd); 108static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 109static void fdunused(struct filedesc *fdp, int fd); 110static void fdused(struct filedesc *fdp, int fd); 111static int getmaxfd(struct thread *td); 112 113/* 114 * Each process has: 115 * 116 * - An array of open file descriptors (fd_ofiles) 117 * - An array of file flags (fd_ofileflags) 118 * - A bitmap recording which descriptors are in use (fd_map) 119 * 120 * A process starts out with NDFILE descriptors. The value of NDFILE has 121 * been selected based the historical limit of 20 open files, and an 122 * assumption that the majority of processes, especially short-lived 123 * processes like shells, will never need more. 124 * 125 * If this initial allocation is exhausted, a larger descriptor table and 126 * map are allocated dynamically, and the pointers in the process's struct 127 * filedesc are updated to point to those. This is repeated every time 128 * the process runs out of file descriptors (provided it hasn't hit its 129 * resource limit). 130 * 131 * Since threads may hold references to individual descriptor table 132 * entries, the tables are never freed. Instead, they are placed on a 133 * linked list and freed only when the struct filedesc is released. 134 */ 135#define NDFILE 20 136#define NDSLOTSIZE sizeof(NDSLOTTYPE) 137#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 138#define NDSLOT(x) ((x) / NDENTRIES) 139#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 140#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 141 142/* 143 * SLIST entry used to keep track of ofiles which must be reclaimed when 144 * the process exits. 145 */ 146struct freetable { 147 struct fdescenttbl *ft_table; 148 SLIST_ENTRY(freetable) ft_next; 149}; 150 151/* 152 * Initial allocation: a filedesc structure + the head of SLIST used to 153 * keep track of old ofiles + enough space for NDFILE descriptors. 154 */ 155 156struct fdescenttbl0 { 157 int fdt_nfiles; 158 struct filedescent fdt_ofiles[NDFILE]; 159}; 160 161struct filedesc0 { 162 struct filedesc fd_fd; 163 SLIST_HEAD(, freetable) fd_free; 164 struct fdescenttbl0 fd_dfiles; 165 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 166}; 167 168/* 169 * Descriptor management. 170 */ 171volatile int openfiles; /* actual number of open files */ 172struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 173void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 174 175/* 176 * If low >= size, just return low. Otherwise find the first zero bit in the 177 * given bitmap, starting at low and not exceeding size - 1. Return size if 178 * not found. 179 */ 180static int 181fd_first_free(struct filedesc *fdp, int low, int size) 182{ 183 NDSLOTTYPE *map = fdp->fd_map; 184 NDSLOTTYPE mask; 185 int off, maxoff; 186 187 if (low >= size) 188 return (low); 189 190 off = NDSLOT(low); 191 if (low % NDENTRIES) { 192 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 193 if ((mask &= ~map[off]) != 0UL) 194 return (off * NDENTRIES + ffsl(mask) - 1); 195 ++off; 196 } 197 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 198 if (map[off] != ~0UL) 199 return (off * NDENTRIES + ffsl(~map[off]) - 1); 200 return (size); 201} 202 203/* 204 * Find the highest non-zero bit in the given bitmap, starting at 0 and 205 * not exceeding size - 1. Return -1 if not found. 206 */ 207static int 208fd_last_used(struct filedesc *fdp, int size) 209{ 210 NDSLOTTYPE *map = fdp->fd_map; 211 NDSLOTTYPE mask; 212 int off, minoff; 213 214 off = NDSLOT(size); 215 if (size % NDENTRIES) { 216 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 217 if ((mask &= map[off]) != 0) 218 return (off * NDENTRIES + flsl(mask) - 1); 219 --off; 220 } 221 for (minoff = NDSLOT(0); off >= minoff; --off) 222 if (map[off] != 0) 223 return (off * NDENTRIES + flsl(map[off]) - 1); 224 return (-1); 225} 226 227static int 228fdisused(struct filedesc *fdp, int fd) 229{ 230 231 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 232 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 233 234 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 235} 236 237/* 238 * Mark a file descriptor as used. 239 */ 240static void 241fdused_init(struct filedesc *fdp, int fd) 242{ 243 244 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 245 246 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 247} 248 249static void 250fdused(struct filedesc *fdp, int fd) 251{ 252 253 FILEDESC_XLOCK_ASSERT(fdp); 254 255 fdused_init(fdp, fd); 256 if (fd > fdp->fd_lastfile) 257 fdp->fd_lastfile = fd; 258 if (fd == fdp->fd_freefile) 259 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 260} 261 262/* 263 * Mark a file descriptor as unused. 264 */ 265static void 266fdunused(struct filedesc *fdp, int fd) 267{ 268 269 FILEDESC_XLOCK_ASSERT(fdp); 270 271 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 272 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 273 ("fd=%d is still in use", fd)); 274 275 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 276 if (fd < fdp->fd_freefile) 277 fdp->fd_freefile = fd; 278 if (fd == fdp->fd_lastfile) 279 fdp->fd_lastfile = fd_last_used(fdp, fd); 280} 281 282/* 283 * Free a file descriptor. 284 * 285 * Avoid some work if fdp is about to be destroyed. 286 */ 287static inline void 288fdefree_last(struct filedescent *fde) 289{ 290 291 filecaps_free(&fde->fde_caps); 292} 293 294static inline void 295fdfree(struct filedesc *fdp, int fd) 296{ 297 struct filedescent *fde; 298 299 fde = &fdp->fd_ofiles[fd]; 300#ifdef CAPABILITIES 301 seq_write_begin(&fde->fde_seq); 302#endif 303 fdefree_last(fde); 304 fde->fde_file = NULL; 305 fdunused(fdp, fd); 306#ifdef CAPABILITIES 307 seq_write_end(&fde->fde_seq); 308#endif 309} 310 311void 312pwd_ensure_dirs(void) 313{ 314 struct filedesc *fdp; 315 316 fdp = curproc->p_fd; 317 FILEDESC_XLOCK(fdp); 318 if (fdp->fd_cdir == NULL) { 319 fdp->fd_cdir = rootvnode; 320 vrefact(rootvnode); 321 } 322 if (fdp->fd_rdir == NULL) { 323 fdp->fd_rdir = rootvnode; 324 vrefact(rootvnode); 325 } 326 FILEDESC_XUNLOCK(fdp); 327} 328 329/* 330 * System calls on descriptors. 331 */ 332#ifndef _SYS_SYSPROTO_H_ 333struct getdtablesize_args { 334 int dummy; 335}; 336#endif 337/* ARGSUSED */ 338int 339sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 340{ 341#ifdef RACCT 342 uint64_t lim; 343#endif 344 345 td->td_retval[0] = 346 min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc); 347#ifdef RACCT 348 PROC_LOCK(td->td_proc); 349 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 350 PROC_UNLOCK(td->td_proc); 351 if (lim < td->td_retval[0]) 352 td->td_retval[0] = lim; 353#endif 354 return (0); 355} 356 357/* 358 * Duplicate a file descriptor to a particular value. 359 * 360 * Note: keep in mind that a potential race condition exists when closing 361 * descriptors from a shared descriptor table (via rfork). 362 */ 363#ifndef _SYS_SYSPROTO_H_ 364struct dup2_args { 365 u_int from; 366 u_int to; 367}; 368#endif 369/* ARGSUSED */ 370int 371sys_dup2(struct thread *td, struct dup2_args *uap) 372{ 373 374 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 375} 376 377/* 378 * Duplicate a file descriptor. 379 */ 380#ifndef _SYS_SYSPROTO_H_ 381struct dup_args { 382 u_int fd; 383}; 384#endif 385/* ARGSUSED */ 386int 387sys_dup(struct thread *td, struct dup_args *uap) 388{ 389 390 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 391} 392 393/* 394 * The file control system call. 395 */ 396#ifndef _SYS_SYSPROTO_H_ 397struct fcntl_args { 398 int fd; 399 int cmd; 400 long arg; 401}; 402#endif 403/* ARGSUSED */ 404int 405sys_fcntl(struct thread *td, struct fcntl_args *uap) 406{ 407 408 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 409} 410 411int 412kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 413{ 414 struct flock fl; 415 struct __oflock ofl; 416 intptr_t arg1; 417 int error, newcmd; 418 419 error = 0; 420 newcmd = cmd; 421 switch (cmd) { 422 case F_OGETLK: 423 case F_OSETLK: 424 case F_OSETLKW: 425 /* 426 * Convert old flock structure to new. 427 */ 428 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 429 fl.l_start = ofl.l_start; 430 fl.l_len = ofl.l_len; 431 fl.l_pid = ofl.l_pid; 432 fl.l_type = ofl.l_type; 433 fl.l_whence = ofl.l_whence; 434 fl.l_sysid = 0; 435 436 switch (cmd) { 437 case F_OGETLK: 438 newcmd = F_GETLK; 439 break; 440 case F_OSETLK: 441 newcmd = F_SETLK; 442 break; 443 case F_OSETLKW: 444 newcmd = F_SETLKW; 445 break; 446 } 447 arg1 = (intptr_t)&fl; 448 break; 449 case F_GETLK: 450 case F_SETLK: 451 case F_SETLKW: 452 case F_SETLK_REMOTE: 453 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 454 arg1 = (intptr_t)&fl; 455 break; 456 default: 457 arg1 = arg; 458 break; 459 } 460 if (error) 461 return (error); 462 error = kern_fcntl(td, fd, newcmd, arg1); 463 if (error) 464 return (error); 465 if (cmd == F_OGETLK) { 466 ofl.l_start = fl.l_start; 467 ofl.l_len = fl.l_len; 468 ofl.l_pid = fl.l_pid; 469 ofl.l_type = fl.l_type; 470 ofl.l_whence = fl.l_whence; 471 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 472 } else if (cmd == F_GETLK) { 473 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 474 } 475 return (error); 476} 477 478int 479kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 480{ 481 struct filedesc *fdp; 482 struct flock *flp; 483 struct file *fp, *fp2; 484 struct filedescent *fde; 485 struct proc *p; 486 struct vnode *vp; 487 cap_rights_t rights; 488 int error, flg, tmp; 489 uint64_t bsize; 490 off_t foffset; 491 492 error = 0; 493 flg = F_POSIX; 494 p = td->td_proc; 495 fdp = p->p_fd; 496 497 switch (cmd) { 498 case F_DUPFD: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 501 break; 502 503 case F_DUPFD_CLOEXEC: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 506 break; 507 508 case F_DUP2FD: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 511 break; 512 513 case F_DUP2FD_CLOEXEC: 514 tmp = arg; 515 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 516 break; 517 518 case F_GETFD: 519 error = EBADF; 520 FILEDESC_SLOCK(fdp); 521 fde = fdeget_locked(fdp, fd); 522 if (fde != NULL) { 523 td->td_retval[0] = 524 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 525 error = 0; 526 } 527 FILEDESC_SUNLOCK(fdp); 528 break; 529 530 case F_SETFD: 531 error = EBADF; 532 FILEDESC_XLOCK(fdp); 533 fde = fdeget_locked(fdp, fd); 534 if (fde != NULL) { 535 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 536 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 537 error = 0; 538 } 539 FILEDESC_XUNLOCK(fdp); 540 break; 541 542 case F_GETFL: 543 error = fget_fcntl(td, fd, 544 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 545 if (error != 0) 546 break; 547 td->td_retval[0] = OFLAGS(fp->f_flag); 548 fdrop(fp, td); 549 break; 550 551 case F_SETFL: 552 error = fget_fcntl(td, fd, 553 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 554 if (error != 0) 555 break; 556 do { 557 tmp = flg = fp->f_flag; 558 tmp &= ~FCNTLFLAGS; 559 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 560 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 561 tmp = fp->f_flag & FNONBLOCK; 562 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 563 if (error != 0) { 564 fdrop(fp, td); 565 break; 566 } 567 tmp = fp->f_flag & FASYNC; 568 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 569 if (error == 0) { 570 fdrop(fp, td); 571 break; 572 } 573 atomic_clear_int(&fp->f_flag, FNONBLOCK); 574 tmp = 0; 575 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 576 fdrop(fp, td); 577 break; 578 579 case F_GETOWN: 580 error = fget_fcntl(td, fd, 581 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 582 if (error != 0) 583 break; 584 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 585 if (error == 0) 586 td->td_retval[0] = tmp; 587 fdrop(fp, td); 588 break; 589 590 case F_SETOWN: 591 error = fget_fcntl(td, fd, 592 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 593 if (error != 0) 594 break; 595 tmp = arg; 596 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 597 fdrop(fp, td); 598 break; 599 600 case F_SETLK_REMOTE: 601 error = priv_check(td, PRIV_NFS_LOCKD); 602 if (error) 603 return (error); 604 flg = F_REMOTE; 605 goto do_setlk; 606 607 case F_SETLKW: 608 flg |= F_WAIT; 609 /* FALLTHROUGH F_SETLK */ 610 611 case F_SETLK: 612 do_setlk: 613 cap_rights_init(&rights, CAP_FLOCK); 614 error = fget_unlocked(fdp, fd, &rights, &fp, NULL); 615 if (error != 0) 616 break; 617 if (fp->f_type != DTYPE_VNODE) { 618 error = EBADF; 619 fdrop(fp, td); 620 break; 621 } 622 623 flp = (struct flock *)arg; 624 if (flp->l_whence == SEEK_CUR) { 625 foffset = foffset_get(fp); 626 if (foffset < 0 || 627 (flp->l_start > 0 && 628 foffset > OFF_MAX - flp->l_start)) { 629 error = EOVERFLOW; 630 fdrop(fp, td); 631 break; 632 } 633 flp->l_start += foffset; 634 } 635 636 vp = fp->f_vnode; 637 switch (flp->l_type) { 638 case F_RDLCK: 639 if ((fp->f_flag & FREAD) == 0) { 640 error = EBADF; 641 break; 642 } 643 PROC_LOCK(p->p_leader); 644 p->p_leader->p_flag |= P_ADVLOCK; 645 PROC_UNLOCK(p->p_leader); 646 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 647 flp, flg); 648 break; 649 case F_WRLCK: 650 if ((fp->f_flag & FWRITE) == 0) { 651 error = EBADF; 652 break; 653 } 654 PROC_LOCK(p->p_leader); 655 p->p_leader->p_flag |= P_ADVLOCK; 656 PROC_UNLOCK(p->p_leader); 657 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 658 flp, flg); 659 break; 660 case F_UNLCK: 661 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 662 flp, flg); 663 break; 664 case F_UNLCKSYS: 665 /* 666 * Temporary api for testing remote lock 667 * infrastructure. 668 */ 669 if (flg != F_REMOTE) { 670 error = EINVAL; 671 break; 672 } 673 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 674 F_UNLCKSYS, flp, flg); 675 break; 676 default: 677 error = EINVAL; 678 break; 679 } 680 if (error != 0 || flp->l_type == F_UNLCK || 681 flp->l_type == F_UNLCKSYS) { 682 fdrop(fp, td); 683 break; 684 } 685 686 /* 687 * Check for a race with close. 688 * 689 * The vnode is now advisory locked (or unlocked, but this case 690 * is not really important) as the caller requested. 691 * We had to drop the filedesc lock, so we need to recheck if 692 * the descriptor is still valid, because if it was closed 693 * in the meantime we need to remove advisory lock from the 694 * vnode - close on any descriptor leading to an advisory 695 * locked vnode, removes that lock. 696 * We will return 0 on purpose in that case, as the result of 697 * successful advisory lock might have been externally visible 698 * already. This is fine - effectively we pretend to the caller 699 * that the closing thread was a bit slower and that the 700 * advisory lock succeeded before the close. 701 */ 702 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 703 if (error != 0) { 704 fdrop(fp, td); 705 break; 706 } 707 if (fp != fp2) { 708 flp->l_whence = SEEK_SET; 709 flp->l_start = 0; 710 flp->l_len = 0; 711 flp->l_type = F_UNLCK; 712 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 713 F_UNLCK, flp, F_POSIX); 714 } 715 fdrop(fp, td); 716 fdrop(fp2, td); 717 break; 718 719 case F_GETLK: 720 error = fget_unlocked(fdp, fd, 721 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 722 if (error != 0) 723 break; 724 if (fp->f_type != DTYPE_VNODE) { 725 error = EBADF; 726 fdrop(fp, td); 727 break; 728 } 729 flp = (struct flock *)arg; 730 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 731 flp->l_type != F_UNLCK) { 732 error = EINVAL; 733 fdrop(fp, td); 734 break; 735 } 736 if (flp->l_whence == SEEK_CUR) { 737 foffset = foffset_get(fp); 738 if ((flp->l_start > 0 && 739 foffset > OFF_MAX - flp->l_start) || 740 (flp->l_start < 0 && 741 foffset < OFF_MIN - flp->l_start)) { 742 error = EOVERFLOW; 743 fdrop(fp, td); 744 break; 745 } 746 flp->l_start += foffset; 747 } 748 vp = fp->f_vnode; 749 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 750 F_POSIX); 751 fdrop(fp, td); 752 break; 753 754 case F_RDAHEAD: 755 arg = arg ? 128 * 1024: 0; 756 /* FALLTHROUGH */ 757 case F_READAHEAD: 758 error = fget_unlocked(fdp, fd, 759 cap_rights_init(&rights), &fp, NULL); 760 if (error != 0) 761 break; 762 if (fp->f_type != DTYPE_VNODE) { 763 fdrop(fp, td); 764 error = EBADF; 765 break; 766 } 767 vp = fp->f_vnode; 768 /* 769 * Exclusive lock synchronizes against f_seqcount reads and 770 * writes in sequential_heuristic(). 771 */ 772 error = vn_lock(vp, LK_EXCLUSIVE); 773 if (error != 0) { 774 fdrop(fp, td); 775 break; 776 } 777 if (arg >= 0) { 778 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 779 fp->f_seqcount = (arg + bsize - 1) / bsize; 780 atomic_set_int(&fp->f_flag, FRDAHEAD); 781 } else { 782 atomic_clear_int(&fp->f_flag, FRDAHEAD); 783 } 784 VOP_UNLOCK(vp, 0); 785 fdrop(fp, td); 786 break; 787 788 default: 789 error = EINVAL; 790 break; 791 } 792 return (error); 793} 794 795static int 796getmaxfd(struct thread *td) 797{ 798 799 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 800} 801 802/* 803 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 804 */ 805int 806kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 807{ 808 struct filedesc *fdp; 809 struct filedescent *oldfde, *newfde; 810 struct proc *p; 811 struct file *delfp; 812 int error, maxfd; 813 814 p = td->td_proc; 815 fdp = p->p_fd; 816 817 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 818 MPASS(mode < FDDUP_LASTMODE); 819 820 AUDIT_ARG_FD(old); 821 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 822 823 /* 824 * Verify we have a valid descriptor to dup from and possibly to 825 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 826 * return EINVAL when the new descriptor is out of bounds. 827 */ 828 if (old < 0) 829 return (EBADF); 830 if (new < 0) 831 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 832 maxfd = getmaxfd(td); 833 if (new >= maxfd) 834 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 835 836 error = EBADF; 837 FILEDESC_XLOCK(fdp); 838 if (fget_locked(fdp, old) == NULL) 839 goto unlock; 840 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 841 td->td_retval[0] = new; 842 if (flags & FDDUP_FLAG_CLOEXEC) 843 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 844 error = 0; 845 goto unlock; 846 } 847 848 /* 849 * If the caller specified a file descriptor, make sure the file 850 * table is large enough to hold it, and grab it. Otherwise, just 851 * allocate a new descriptor the usual way. 852 */ 853 switch (mode) { 854 case FDDUP_NORMAL: 855 case FDDUP_FCNTL: 856 if ((error = fdalloc(td, new, &new)) != 0) 857 goto unlock; 858 break; 859 case FDDUP_MUSTREPLACE: 860 /* Target file descriptor must exist. */ 861 if (fget_locked(fdp, new) == NULL) 862 goto unlock; 863 break; 864 case FDDUP_FIXED: 865 if (new >= fdp->fd_nfiles) { 866 /* 867 * The resource limits are here instead of e.g. 868 * fdalloc(), because the file descriptor table may be 869 * shared between processes, so we can't really use 870 * racct_add()/racct_sub(). Instead of counting the 871 * number of actually allocated descriptors, just put 872 * the limit on the size of the file descriptor table. 873 */ 874#ifdef RACCT 875 if (racct_enable) { 876 PROC_LOCK(p); 877 error = racct_set(p, RACCT_NOFILE, new + 1); 878 PROC_UNLOCK(p); 879 if (error != 0) { 880 error = EMFILE; 881 goto unlock; 882 } 883 } 884#endif 885 fdgrowtable_exp(fdp, new + 1); 886 } 887 if (!fdisused(fdp, new)) 888 fdused(fdp, new); 889 break; 890 default: 891 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 892 } 893 894 KASSERT(old != new, ("new fd is same as old")); 895 896 oldfde = &fdp->fd_ofiles[old]; 897 fhold(oldfde->fde_file); 898 newfde = &fdp->fd_ofiles[new]; 899 delfp = newfde->fde_file; 900 901 /* 902 * Duplicate the source descriptor. 903 */ 904#ifdef CAPABILITIES 905 seq_write_begin(&newfde->fde_seq); 906#endif 907 filecaps_free(&newfde->fde_caps); 908 memcpy(newfde, oldfde, fde_change_size); 909 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps, true); 910 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 911 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 912 else 913 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 914#ifdef CAPABILITIES 915 seq_write_end(&newfde->fde_seq); 916#endif 917 td->td_retval[0] = new; 918 919 error = 0; 920 921 if (delfp != NULL) { 922 (void) closefp(fdp, new, delfp, td, 1); 923 FILEDESC_UNLOCK_ASSERT(fdp); 924 } else { 925unlock: 926 FILEDESC_XUNLOCK(fdp); 927 } 928 929 return (error); 930} 931 932/* 933 * If sigio is on the list associated with a process or process group, 934 * disable signalling from the device, remove sigio from the list and 935 * free sigio. 936 */ 937void 938funsetown(struct sigio **sigiop) 939{ 940 struct sigio *sigio; 941 942 if (*sigiop == NULL) 943 return; 944 SIGIO_LOCK(); 945 sigio = *sigiop; 946 if (sigio == NULL) { 947 SIGIO_UNLOCK(); 948 return; 949 } 950 *(sigio->sio_myref) = NULL; 951 if ((sigio)->sio_pgid < 0) { 952 struct pgrp *pg = (sigio)->sio_pgrp; 953 PGRP_LOCK(pg); 954 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 955 sigio, sio_pgsigio); 956 PGRP_UNLOCK(pg); 957 } else { 958 struct proc *p = (sigio)->sio_proc; 959 PROC_LOCK(p); 960 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 961 sigio, sio_pgsigio); 962 PROC_UNLOCK(p); 963 } 964 SIGIO_UNLOCK(); 965 crfree(sigio->sio_ucred); 966 free(sigio, M_SIGIO); 967} 968 969/* 970 * Free a list of sigio structures. 971 * We only need to lock the SIGIO_LOCK because we have made ourselves 972 * inaccessible to callers of fsetown and therefore do not need to lock 973 * the proc or pgrp struct for the list manipulation. 974 */ 975void 976funsetownlst(struct sigiolst *sigiolst) 977{ 978 struct proc *p; 979 struct pgrp *pg; 980 struct sigio *sigio; 981 982 sigio = SLIST_FIRST(sigiolst); 983 if (sigio == NULL) 984 return; 985 p = NULL; 986 pg = NULL; 987 988 /* 989 * Every entry of the list should belong 990 * to a single proc or pgrp. 991 */ 992 if (sigio->sio_pgid < 0) { 993 pg = sigio->sio_pgrp; 994 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 995 } else /* if (sigio->sio_pgid > 0) */ { 996 p = sigio->sio_proc; 997 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 998 } 999 1000 SIGIO_LOCK(); 1001 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1002 *(sigio->sio_myref) = NULL; 1003 if (pg != NULL) { 1004 KASSERT(sigio->sio_pgid < 0, 1005 ("Proc sigio in pgrp sigio list")); 1006 KASSERT(sigio->sio_pgrp == pg, 1007 ("Bogus pgrp in sigio list")); 1008 PGRP_LOCK(pg); 1009 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1010 sio_pgsigio); 1011 PGRP_UNLOCK(pg); 1012 } else /* if (p != NULL) */ { 1013 KASSERT(sigio->sio_pgid > 0, 1014 ("Pgrp sigio in proc sigio list")); 1015 KASSERT(sigio->sio_proc == p, 1016 ("Bogus proc in sigio list")); 1017 PROC_LOCK(p); 1018 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1019 sio_pgsigio); 1020 PROC_UNLOCK(p); 1021 } 1022 SIGIO_UNLOCK(); 1023 crfree(sigio->sio_ucred); 1024 free(sigio, M_SIGIO); 1025 SIGIO_LOCK(); 1026 } 1027 SIGIO_UNLOCK(); 1028} 1029 1030/* 1031 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1032 * 1033 * After permission checking, add a sigio structure to the sigio list for 1034 * the process or process group. 1035 */ 1036int 1037fsetown(pid_t pgid, struct sigio **sigiop) 1038{ 1039 struct proc *proc; 1040 struct pgrp *pgrp; 1041 struct sigio *sigio; 1042 int ret; 1043 1044 if (pgid == 0) { 1045 funsetown(sigiop); 1046 return (0); 1047 } 1048 1049 ret = 0; 1050 1051 /* Allocate and fill in the new sigio out of locks. */ 1052 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1053 sigio->sio_pgid = pgid; 1054 sigio->sio_ucred = crhold(curthread->td_ucred); 1055 sigio->sio_myref = sigiop; 1056 1057 sx_slock(&proctree_lock); 1058 if (pgid > 0) { 1059 proc = pfind(pgid); 1060 if (proc == NULL) { 1061 ret = ESRCH; 1062 goto fail; 1063 } 1064 1065 /* 1066 * Policy - Don't allow a process to FSETOWN a process 1067 * in another session. 1068 * 1069 * Remove this test to allow maximum flexibility or 1070 * restrict FSETOWN to the current process or process 1071 * group for maximum safety. 1072 */ 1073 PROC_UNLOCK(proc); 1074 if (proc->p_session != curthread->td_proc->p_session) { 1075 ret = EPERM; 1076 goto fail; 1077 } 1078 1079 pgrp = NULL; 1080 } else /* if (pgid < 0) */ { 1081 pgrp = pgfind(-pgid); 1082 if (pgrp == NULL) { 1083 ret = ESRCH; 1084 goto fail; 1085 } 1086 PGRP_UNLOCK(pgrp); 1087 1088 /* 1089 * Policy - Don't allow a process to FSETOWN a process 1090 * in another session. 1091 * 1092 * Remove this test to allow maximum flexibility or 1093 * restrict FSETOWN to the current process or process 1094 * group for maximum safety. 1095 */ 1096 if (pgrp->pg_session != curthread->td_proc->p_session) { 1097 ret = EPERM; 1098 goto fail; 1099 } 1100 1101 proc = NULL; 1102 } 1103 funsetown(sigiop); 1104 if (pgid > 0) { 1105 PROC_LOCK(proc); 1106 /* 1107 * Since funsetownlst() is called without the proctree 1108 * locked, we need to check for P_WEXIT. 1109 * XXX: is ESRCH correct? 1110 */ 1111 if ((proc->p_flag & P_WEXIT) != 0) { 1112 PROC_UNLOCK(proc); 1113 ret = ESRCH; 1114 goto fail; 1115 } 1116 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1117 sigio->sio_proc = proc; 1118 PROC_UNLOCK(proc); 1119 } else { 1120 PGRP_LOCK(pgrp); 1121 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1122 sigio->sio_pgrp = pgrp; 1123 PGRP_UNLOCK(pgrp); 1124 } 1125 sx_sunlock(&proctree_lock); 1126 SIGIO_LOCK(); 1127 *sigiop = sigio; 1128 SIGIO_UNLOCK(); 1129 return (0); 1130 1131fail: 1132 sx_sunlock(&proctree_lock); 1133 crfree(sigio->sio_ucred); 1134 free(sigio, M_SIGIO); 1135 return (ret); 1136} 1137 1138/* 1139 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1140 */ 1141pid_t 1142fgetown(sigiop) 1143 struct sigio **sigiop; 1144{ 1145 pid_t pgid; 1146 1147 SIGIO_LOCK(); 1148 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1149 SIGIO_UNLOCK(); 1150 return (pgid); 1151} 1152 1153/* 1154 * Function drops the filedesc lock on return. 1155 */ 1156static int 1157closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1158 int holdleaders) 1159{ 1160 int error; 1161 1162 FILEDESC_XLOCK_ASSERT(fdp); 1163 1164 if (holdleaders) { 1165 if (td->td_proc->p_fdtol != NULL) { 1166 /* 1167 * Ask fdfree() to sleep to ensure that all relevant 1168 * process leaders can be traversed in closef(). 1169 */ 1170 fdp->fd_holdleaderscount++; 1171 } else { 1172 holdleaders = 0; 1173 } 1174 } 1175 1176 /* 1177 * We now hold the fp reference that used to be owned by the 1178 * descriptor array. We have to unlock the FILEDESC *AFTER* 1179 * knote_fdclose to prevent a race of the fd getting opened, a knote 1180 * added, and deleteing a knote for the new fd. 1181 */ 1182 knote_fdclose(td, fd); 1183 1184 /* 1185 * We need to notify mqueue if the object is of type mqueue. 1186 */ 1187 if (fp->f_type == DTYPE_MQUEUE) 1188 mq_fdclose(td, fd, fp); 1189 FILEDESC_XUNLOCK(fdp); 1190 1191 error = closef(fp, td); 1192 if (holdleaders) { 1193 FILEDESC_XLOCK(fdp); 1194 fdp->fd_holdleaderscount--; 1195 if (fdp->fd_holdleaderscount == 0 && 1196 fdp->fd_holdleaderswakeup != 0) { 1197 fdp->fd_holdleaderswakeup = 0; 1198 wakeup(&fdp->fd_holdleaderscount); 1199 } 1200 FILEDESC_XUNLOCK(fdp); 1201 } 1202 return (error); 1203} 1204 1205/* 1206 * Close a file descriptor. 1207 */ 1208#ifndef _SYS_SYSPROTO_H_ 1209struct close_args { 1210 int fd; 1211}; 1212#endif 1213/* ARGSUSED */ 1214int 1215sys_close(struct thread *td, struct close_args *uap) 1216{ 1217 1218 return (kern_close(td, uap->fd)); 1219} 1220 1221int 1222kern_close(struct thread *td, int fd) 1223{ 1224 struct filedesc *fdp; 1225 struct file *fp; 1226 1227 fdp = td->td_proc->p_fd; 1228 1229 AUDIT_SYSCLOSE(td, fd); 1230 1231 FILEDESC_XLOCK(fdp); 1232 if ((fp = fget_locked(fdp, fd)) == NULL) { 1233 FILEDESC_XUNLOCK(fdp); 1234 return (EBADF); 1235 } 1236 fdfree(fdp, fd); 1237 1238 /* closefp() drops the FILEDESC lock for us. */ 1239 return (closefp(fdp, fd, fp, td, 1)); 1240} 1241 1242/* 1243 * Close open file descriptors. 1244 */ 1245#ifndef _SYS_SYSPROTO_H_ 1246struct closefrom_args { 1247 int lowfd; 1248}; 1249#endif 1250/* ARGSUSED */ 1251int 1252sys_closefrom(struct thread *td, struct closefrom_args *uap) 1253{ 1254 struct filedesc *fdp; 1255 int fd; 1256 1257 fdp = td->td_proc->p_fd; 1258 AUDIT_ARG_FD(uap->lowfd); 1259 1260 /* 1261 * Treat negative starting file descriptor values identical to 1262 * closefrom(0) which closes all files. 1263 */ 1264 if (uap->lowfd < 0) 1265 uap->lowfd = 0; 1266 FILEDESC_SLOCK(fdp); 1267 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1268 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1269 FILEDESC_SUNLOCK(fdp); 1270 (void)kern_close(td, fd); 1271 FILEDESC_SLOCK(fdp); 1272 } 1273 } 1274 FILEDESC_SUNLOCK(fdp); 1275 return (0); 1276} 1277 1278#if defined(COMPAT_43) 1279/* 1280 * Return status information about a file descriptor. 1281 */ 1282#ifndef _SYS_SYSPROTO_H_ 1283struct ofstat_args { 1284 int fd; 1285 struct ostat *sb; 1286}; 1287#endif 1288/* ARGSUSED */ 1289int 1290ofstat(struct thread *td, struct ofstat_args *uap) 1291{ 1292 struct ostat oub; 1293 struct stat ub; 1294 int error; 1295 1296 error = kern_fstat(td, uap->fd, &ub); 1297 if (error == 0) { 1298 cvtstat(&ub, &oub); 1299 error = copyout(&oub, uap->sb, sizeof(oub)); 1300 } 1301 return (error); 1302} 1303#endif /* COMPAT_43 */ 1304 1305/* 1306 * Return status information about a file descriptor. 1307 */ 1308#ifndef _SYS_SYSPROTO_H_ 1309struct fstat_args { 1310 int fd; 1311 struct stat *sb; 1312}; 1313#endif 1314/* ARGSUSED */ 1315int 1316sys_fstat(struct thread *td, struct fstat_args *uap) 1317{ 1318 struct stat ub; 1319 int error; 1320 1321 error = kern_fstat(td, uap->fd, &ub); 1322 if (error == 0) 1323 error = copyout(&ub, uap->sb, sizeof(ub)); 1324 return (error); 1325} 1326 1327int 1328kern_fstat(struct thread *td, int fd, struct stat *sbp) 1329{ 1330 struct file *fp; 1331 cap_rights_t rights; 1332 int error; 1333 1334 AUDIT_ARG_FD(fd); 1335 1336 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1337 if (error != 0) 1338 return (error); 1339 1340 AUDIT_ARG_FILE(td->td_proc, fp); 1341 1342 error = fo_stat(fp, sbp, td->td_ucred, td); 1343 fdrop(fp, td); 1344#ifdef KTRACE 1345 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1346 ktrstat(sbp); 1347#endif 1348 return (error); 1349} 1350 1351/* 1352 * Return status information about a file descriptor. 1353 */ 1354#ifndef _SYS_SYSPROTO_H_ 1355struct nfstat_args { 1356 int fd; 1357 struct nstat *sb; 1358}; 1359#endif 1360/* ARGSUSED */ 1361int 1362sys_nfstat(struct thread *td, struct nfstat_args *uap) 1363{ 1364 struct nstat nub; 1365 struct stat ub; 1366 int error; 1367 1368 error = kern_fstat(td, uap->fd, &ub); 1369 if (error == 0) { 1370 cvtnstat(&ub, &nub); 1371 error = copyout(&nub, uap->sb, sizeof(nub)); 1372 } 1373 return (error); 1374} 1375 1376/* 1377 * Return pathconf information about a file descriptor. 1378 */ 1379#ifndef _SYS_SYSPROTO_H_ 1380struct fpathconf_args { 1381 int fd; 1382 int name; 1383}; 1384#endif 1385/* ARGSUSED */ 1386int 1387sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1388{ 1389 struct file *fp; 1390 struct vnode *vp; 1391 cap_rights_t rights; 1392 int error; 1393 1394 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1395 if (error != 0) 1396 return (error); 1397 1398 if (uap->name == _PC_ASYNC_IO) { 1399 td->td_retval[0] = _POSIX_ASYNCHRONOUS_IO; 1400 goto out; 1401 } 1402 vp = fp->f_vnode; 1403 if (vp != NULL) { 1404 vn_lock(vp, LK_SHARED | LK_RETRY); 1405 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1406 VOP_UNLOCK(vp, 0); 1407 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1408 if (uap->name != _PC_PIPE_BUF) { 1409 error = EINVAL; 1410 } else { 1411 td->td_retval[0] = PIPE_BUF; 1412 error = 0; 1413 } 1414 } else { 1415 error = EOPNOTSUPP; 1416 } 1417out: 1418 fdrop(fp, td); 1419 return (error); 1420} 1421 1422/* 1423 * Initialize filecaps structure. 1424 */ 1425void 1426filecaps_init(struct filecaps *fcaps) 1427{ 1428 1429 bzero(fcaps, sizeof(*fcaps)); 1430 fcaps->fc_nioctls = -1; 1431} 1432 1433/* 1434 * Copy filecaps structure allocating memory for ioctls array if needed. 1435 * 1436 * The last parameter indicates whether the fdtable is locked. If it is not and 1437 * ioctls are encountered, copying fails and the caller must lock the table. 1438 * 1439 * Note that if the table was not locked, the caller has to check the relevant 1440 * sequence counter to determine whether the operation was successful. 1441 */ 1442int 1443filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1444{ 1445 size_t size; 1446 1447 *dst = *src; 1448 if (src->fc_ioctls == NULL) 1449 return (0); 1450 if (!locked) 1451 return (1); 1452 1453 KASSERT(src->fc_nioctls > 0, 1454 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1455 1456 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1457 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1458 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1459 return (0); 1460} 1461 1462/* 1463 * Move filecaps structure to the new place and clear the old place. 1464 */ 1465void 1466filecaps_move(struct filecaps *src, struct filecaps *dst) 1467{ 1468 1469 *dst = *src; 1470 bzero(src, sizeof(*src)); 1471} 1472 1473/* 1474 * Fill the given filecaps structure with full rights. 1475 */ 1476static void 1477filecaps_fill(struct filecaps *fcaps) 1478{ 1479 1480 CAP_ALL(&fcaps->fc_rights); 1481 fcaps->fc_ioctls = NULL; 1482 fcaps->fc_nioctls = -1; 1483 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1484} 1485 1486/* 1487 * Free memory allocated within filecaps structure. 1488 */ 1489void 1490filecaps_free(struct filecaps *fcaps) 1491{ 1492 1493 free(fcaps->fc_ioctls, M_FILECAPS); 1494 bzero(fcaps, sizeof(*fcaps)); 1495} 1496 1497/* 1498 * Validate the given filecaps structure. 1499 */ 1500static void 1501filecaps_validate(const struct filecaps *fcaps, const char *func) 1502{ 1503 1504 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1505 ("%s: invalid rights", func)); 1506 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1507 ("%s: invalid fcntls", func)); 1508 KASSERT(fcaps->fc_fcntls == 0 || 1509 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1510 ("%s: fcntls without CAP_FCNTL", func)); 1511 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1512 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1513 ("%s: invalid ioctls", func)); 1514 KASSERT(fcaps->fc_nioctls == 0 || 1515 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1516 ("%s: ioctls without CAP_IOCTL", func)); 1517} 1518 1519static void 1520fdgrowtable_exp(struct filedesc *fdp, int nfd) 1521{ 1522 int nfd1; 1523 1524 FILEDESC_XLOCK_ASSERT(fdp); 1525 1526 nfd1 = fdp->fd_nfiles * 2; 1527 if (nfd1 < nfd) 1528 nfd1 = nfd; 1529 fdgrowtable(fdp, nfd1); 1530} 1531 1532/* 1533 * Grow the file table to accommodate (at least) nfd descriptors. 1534 */ 1535static void 1536fdgrowtable(struct filedesc *fdp, int nfd) 1537{ 1538 struct filedesc0 *fdp0; 1539 struct freetable *ft; 1540 struct fdescenttbl *ntable; 1541 struct fdescenttbl *otable; 1542 int nnfiles, onfiles; 1543 NDSLOTTYPE *nmap, *omap; 1544 1545 /* 1546 * If lastfile is -1 this struct filedesc was just allocated and we are 1547 * growing it to accommodate for the one we are going to copy from. There 1548 * is no need to have a lock on this one as it's not visible to anyone. 1549 */ 1550 if (fdp->fd_lastfile != -1) 1551 FILEDESC_XLOCK_ASSERT(fdp); 1552 1553 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1554 1555 /* save old values */ 1556 onfiles = fdp->fd_nfiles; 1557 otable = fdp->fd_files; 1558 omap = fdp->fd_map; 1559 1560 /* compute the size of the new table */ 1561 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1562 if (nnfiles <= onfiles) 1563 /* the table is already large enough */ 1564 return; 1565 1566 /* 1567 * Allocate a new table. We need enough space for the number of 1568 * entries, file entries themselves and the struct freetable we will use 1569 * when we decommission the table and place it on the freelist. 1570 * We place the struct freetable in the middle so we don't have 1571 * to worry about padding. 1572 */ 1573 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1574 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1575 sizeof(struct freetable), 1576 M_FILEDESC, M_ZERO | M_WAITOK); 1577 /* copy the old data */ 1578 ntable->fdt_nfiles = nnfiles; 1579 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1580 onfiles * sizeof(ntable->fdt_ofiles[0])); 1581 1582 /* 1583 * Allocate a new map only if the old is not large enough. It will 1584 * grow at a slower rate than the table as it can map more 1585 * entries than the table can hold. 1586 */ 1587 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1588 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1589 M_ZERO | M_WAITOK); 1590 /* copy over the old data and update the pointer */ 1591 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1592 fdp->fd_map = nmap; 1593 } 1594 1595 /* 1596 * Make sure that ntable is correctly initialized before we replace 1597 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1598 * data. 1599 */ 1600 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1601 1602 /* 1603 * Do not free the old file table, as some threads may still 1604 * reference entries within it. Instead, place it on a freelist 1605 * which will be processed when the struct filedesc is released. 1606 * 1607 * Note that if onfiles == NDFILE, we're dealing with the original 1608 * static allocation contained within (struct filedesc0 *)fdp, 1609 * which must not be freed. 1610 */ 1611 if (onfiles > NDFILE) { 1612 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1613 fdp0 = (struct filedesc0 *)fdp; 1614 ft->ft_table = otable; 1615 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1616 } 1617 /* 1618 * The map does not have the same possibility of threads still 1619 * holding references to it. So always free it as long as it 1620 * does not reference the original static allocation. 1621 */ 1622 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1623 free(omap, M_FILEDESC); 1624} 1625 1626/* 1627 * Allocate a file descriptor for the process. 1628 */ 1629int 1630fdalloc(struct thread *td, int minfd, int *result) 1631{ 1632 struct proc *p = td->td_proc; 1633 struct filedesc *fdp = p->p_fd; 1634 int fd, maxfd, allocfd; 1635#ifdef RACCT 1636 int error; 1637#endif 1638 1639 FILEDESC_XLOCK_ASSERT(fdp); 1640 1641 if (fdp->fd_freefile > minfd) 1642 minfd = fdp->fd_freefile; 1643 1644 maxfd = getmaxfd(td); 1645 1646 /* 1647 * Search the bitmap for a free descriptor starting at minfd. 1648 * If none is found, grow the file table. 1649 */ 1650 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1651 if (fd >= maxfd) 1652 return (EMFILE); 1653 if (fd >= fdp->fd_nfiles) { 1654 allocfd = min(fd * 2, maxfd); 1655#ifdef RACCT 1656 if (racct_enable) { 1657 PROC_LOCK(p); 1658 error = racct_set(p, RACCT_NOFILE, allocfd); 1659 PROC_UNLOCK(p); 1660 if (error != 0) 1661 return (EMFILE); 1662 } 1663#endif 1664 /* 1665 * fd is already equal to first free descriptor >= minfd, so 1666 * we only need to grow the table and we are done. 1667 */ 1668 fdgrowtable_exp(fdp, allocfd); 1669 } 1670 1671 /* 1672 * Perform some sanity checks, then mark the file descriptor as 1673 * used and return it to the caller. 1674 */ 1675 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1676 ("invalid descriptor %d", fd)); 1677 KASSERT(!fdisused(fdp, fd), 1678 ("fd_first_free() returned non-free descriptor")); 1679 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1680 ("file descriptor isn't free")); 1681 fdused(fdp, fd); 1682 *result = fd; 1683 return (0); 1684} 1685 1686/* 1687 * Allocate n file descriptors for the process. 1688 */ 1689int 1690fdallocn(struct thread *td, int minfd, int *fds, int n) 1691{ 1692 struct proc *p = td->td_proc; 1693 struct filedesc *fdp = p->p_fd; 1694 int i; 1695 1696 FILEDESC_XLOCK_ASSERT(fdp); 1697 1698 for (i = 0; i < n; i++) 1699 if (fdalloc(td, 0, &fds[i]) != 0) 1700 break; 1701 1702 if (i < n) { 1703 for (i--; i >= 0; i--) 1704 fdunused(fdp, fds[i]); 1705 return (EMFILE); 1706 } 1707 1708 return (0); 1709} 1710 1711/* 1712 * Create a new open file structure and allocate a file descriptor for the 1713 * process that refers to it. We add one reference to the file for the 1714 * descriptor table and one reference for resultfp. This is to prevent us 1715 * being preempted and the entry in the descriptor table closed after we 1716 * release the FILEDESC lock. 1717 */ 1718int 1719falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1720 struct filecaps *fcaps) 1721{ 1722 struct file *fp; 1723 int error, fd; 1724 1725 error = falloc_noinstall(td, &fp); 1726 if (error) 1727 return (error); /* no reference held on error */ 1728 1729 error = finstall(td, fp, &fd, flags, fcaps); 1730 if (error) { 1731 fdrop(fp, td); /* one reference (fp only) */ 1732 return (error); 1733 } 1734 1735 if (resultfp != NULL) 1736 *resultfp = fp; /* copy out result */ 1737 else 1738 fdrop(fp, td); /* release local reference */ 1739 1740 if (resultfd != NULL) 1741 *resultfd = fd; 1742 1743 return (0); 1744} 1745 1746/* 1747 * Create a new open file structure without allocating a file descriptor. 1748 */ 1749int 1750falloc_noinstall(struct thread *td, struct file **resultfp) 1751{ 1752 struct file *fp; 1753 int maxuserfiles = maxfiles - (maxfiles / 20); 1754 int openfiles_new; 1755 static struct timeval lastfail; 1756 static int curfail; 1757 1758 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1759 1760 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1761 if ((openfiles_new >= maxuserfiles && 1762 priv_check(td, PRIV_MAXFILES) != 0) || 1763 openfiles_new >= maxfiles) { 1764 atomic_subtract_int(&openfiles, 1); 1765 if (ppsratecheck(&lastfail, &curfail, 1)) { 1766 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1767 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1768 } 1769 return (ENFILE); 1770 } 1771 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1772 refcount_init(&fp->f_count, 1); 1773 fp->f_cred = crhold(td->td_ucred); 1774 fp->f_ops = &badfileops; 1775 *resultfp = fp; 1776 return (0); 1777} 1778 1779/* 1780 * Install a file in a file descriptor table. 1781 */ 1782void 1783_finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1784 struct filecaps *fcaps) 1785{ 1786 struct filedescent *fde; 1787 1788 MPASS(fp != NULL); 1789 if (fcaps != NULL) 1790 filecaps_validate(fcaps, __func__); 1791 FILEDESC_XLOCK_ASSERT(fdp); 1792 1793 fde = &fdp->fd_ofiles[fd]; 1794#ifdef CAPABILITIES 1795 seq_write_begin(&fde->fde_seq); 1796#endif 1797 fde->fde_file = fp; 1798 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1799 if (fcaps != NULL) 1800 filecaps_move(fcaps, &fde->fde_caps); 1801 else 1802 filecaps_fill(&fde->fde_caps); 1803#ifdef CAPABILITIES 1804 seq_write_end(&fde->fde_seq); 1805#endif 1806} 1807 1808int 1809finstall(struct thread *td, struct file *fp, int *fd, int flags, 1810 struct filecaps *fcaps) 1811{ 1812 struct filedesc *fdp = td->td_proc->p_fd; 1813 int error; 1814 1815 MPASS(fd != NULL); 1816 1817 FILEDESC_XLOCK(fdp); 1818 if ((error = fdalloc(td, 0, fd))) { 1819 FILEDESC_XUNLOCK(fdp); 1820 return (error); 1821 } 1822 fhold(fp); 1823 _finstall(fdp, fp, *fd, flags, fcaps); 1824 FILEDESC_XUNLOCK(fdp); 1825 return (0); 1826} 1827 1828/* 1829 * Build a new filedesc structure from another. 1830 * Copy the current, root, and jail root vnode references. 1831 * 1832 * If fdp is not NULL, return with it shared locked. 1833 */ 1834struct filedesc * 1835fdinit(struct filedesc *fdp, bool prepfiles) 1836{ 1837 struct filedesc0 *newfdp0; 1838 struct filedesc *newfdp; 1839 1840 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1841 newfdp = &newfdp0->fd_fd; 1842 1843 /* Create the file descriptor table. */ 1844 FILEDESC_LOCK_INIT(newfdp); 1845 refcount_init(&newfdp->fd_refcnt, 1); 1846 refcount_init(&newfdp->fd_holdcnt, 1); 1847 newfdp->fd_cmask = CMASK; 1848 newfdp->fd_map = newfdp0->fd_dmap; 1849 newfdp->fd_lastfile = -1; 1850 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1851 newfdp->fd_files->fdt_nfiles = NDFILE; 1852 1853 if (fdp == NULL) 1854 return (newfdp); 1855 1856 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1857 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1858 1859 FILEDESC_SLOCK(fdp); 1860 newfdp->fd_cdir = fdp->fd_cdir; 1861 if (newfdp->fd_cdir) 1862 vrefact(newfdp->fd_cdir); 1863 newfdp->fd_rdir = fdp->fd_rdir; 1864 if (newfdp->fd_rdir) 1865 vrefact(newfdp->fd_rdir); 1866 newfdp->fd_jdir = fdp->fd_jdir; 1867 if (newfdp->fd_jdir) 1868 vrefact(newfdp->fd_jdir); 1869 1870 if (!prepfiles) { 1871 FILEDESC_SUNLOCK(fdp); 1872 } else { 1873 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1874 FILEDESC_SUNLOCK(fdp); 1875 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1876 FILEDESC_SLOCK(fdp); 1877 } 1878 } 1879 1880 return (newfdp); 1881} 1882 1883static struct filedesc * 1884fdhold(struct proc *p) 1885{ 1886 struct filedesc *fdp; 1887 1888 PROC_LOCK_ASSERT(p, MA_OWNED); 1889 fdp = p->p_fd; 1890 if (fdp != NULL) 1891 refcount_acquire(&fdp->fd_holdcnt); 1892 return (fdp); 1893} 1894 1895static void 1896fddrop(struct filedesc *fdp) 1897{ 1898 1899 if (fdp->fd_holdcnt > 1) { 1900 if (refcount_release(&fdp->fd_holdcnt) == 0) 1901 return; 1902 } 1903 1904 FILEDESC_LOCK_DESTROY(fdp); 1905 uma_zfree(filedesc0_zone, fdp); 1906} 1907 1908/* 1909 * Share a filedesc structure. 1910 */ 1911struct filedesc * 1912fdshare(struct filedesc *fdp) 1913{ 1914 1915 refcount_acquire(&fdp->fd_refcnt); 1916 return (fdp); 1917} 1918 1919/* 1920 * Unshare a filedesc structure, if necessary by making a copy 1921 */ 1922void 1923fdunshare(struct thread *td) 1924{ 1925 struct filedesc *tmp; 1926 struct proc *p = td->td_proc; 1927 1928 if (p->p_fd->fd_refcnt == 1) 1929 return; 1930 1931 tmp = fdcopy(p->p_fd); 1932 fdescfree(td); 1933 p->p_fd = tmp; 1934} 1935 1936void 1937fdinstall_remapped(struct thread *td, struct filedesc *fdp) 1938{ 1939 1940 fdescfree(td); 1941 td->td_proc->p_fd = fdp; 1942} 1943 1944/* 1945 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1946 * this is to ease callers, not catch errors. 1947 */ 1948struct filedesc * 1949fdcopy(struct filedesc *fdp) 1950{ 1951 struct filedesc *newfdp; 1952 struct filedescent *nfde, *ofde; 1953 int i; 1954 1955 MPASS(fdp != NULL); 1956 1957 newfdp = fdinit(fdp, true); 1958 /* copy all passable descriptors (i.e. not kqueue) */ 1959 newfdp->fd_freefile = -1; 1960 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1961 ofde = &fdp->fd_ofiles[i]; 1962 if (ofde->fde_file == NULL || 1963 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1964 if (newfdp->fd_freefile == -1) 1965 newfdp->fd_freefile = i; 1966 continue; 1967 } 1968 nfde = &newfdp->fd_ofiles[i]; 1969 *nfde = *ofde; 1970 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 1971 fhold(nfde->fde_file); 1972 fdused_init(newfdp, i); 1973 newfdp->fd_lastfile = i; 1974 } 1975 if (newfdp->fd_freefile == -1) 1976 newfdp->fd_freefile = i; 1977 newfdp->fd_cmask = fdp->fd_cmask; 1978 FILEDESC_SUNLOCK(fdp); 1979 return (newfdp); 1980} 1981 1982/* 1983 * Copies a filedesc structure, while remapping all file descriptors 1984 * stored inside using a translation table. 1985 * 1986 * File descriptors are copied over to the new file descriptor table, 1987 * regardless of whether the close-on-exec flag is set. 1988 */ 1989int 1990fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 1991 struct filedesc **ret) 1992{ 1993 struct filedesc *newfdp; 1994 struct filedescent *nfde, *ofde; 1995 int error, i; 1996 1997 MPASS(fdp != NULL); 1998 1999 newfdp = fdinit(fdp, true); 2000 if (nfds > fdp->fd_lastfile + 1) { 2001 /* New table cannot be larger than the old one. */ 2002 error = E2BIG; 2003 goto bad; 2004 } 2005 /* Copy all passable descriptors (i.e. not kqueue). */ 2006 newfdp->fd_freefile = nfds; 2007 for (i = 0; i < nfds; ++i) { 2008 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2009 /* File descriptor out of bounds. */ 2010 error = EBADF; 2011 goto bad; 2012 } 2013 ofde = &fdp->fd_ofiles[fds[i]]; 2014 if (ofde->fde_file == NULL) { 2015 /* Unused file descriptor. */ 2016 error = EBADF; 2017 goto bad; 2018 } 2019 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2020 /* File descriptor cannot be passed. */ 2021 error = EINVAL; 2022 goto bad; 2023 } 2024 nfde = &newfdp->fd_ofiles[i]; 2025 *nfde = *ofde; 2026 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2027 fhold(nfde->fde_file); 2028 fdused_init(newfdp, i); 2029 newfdp->fd_lastfile = i; 2030 } 2031 newfdp->fd_cmask = fdp->fd_cmask; 2032 FILEDESC_SUNLOCK(fdp); 2033 *ret = newfdp; 2034 return (0); 2035bad: 2036 FILEDESC_SUNLOCK(fdp); 2037 fdescfree_remapped(newfdp); 2038 return (error); 2039} 2040 2041/* 2042 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2043 * one of processes using it exits) and the table used to be shared. 2044 */ 2045static void 2046fdclearlocks(struct thread *td) 2047{ 2048 struct filedesc *fdp; 2049 struct filedesc_to_leader *fdtol; 2050 struct flock lf; 2051 struct file *fp; 2052 struct proc *p; 2053 struct vnode *vp; 2054 int i; 2055 2056 p = td->td_proc; 2057 fdp = p->p_fd; 2058 fdtol = p->p_fdtol; 2059 MPASS(fdtol != NULL); 2060 2061 FILEDESC_XLOCK(fdp); 2062 KASSERT(fdtol->fdl_refcount > 0, 2063 ("filedesc_to_refcount botch: fdl_refcount=%d", 2064 fdtol->fdl_refcount)); 2065 if (fdtol->fdl_refcount == 1 && 2066 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2067 for (i = 0; i <= fdp->fd_lastfile; i++) { 2068 fp = fdp->fd_ofiles[i].fde_file; 2069 if (fp == NULL || fp->f_type != DTYPE_VNODE) 2070 continue; 2071 fhold(fp); 2072 FILEDESC_XUNLOCK(fdp); 2073 lf.l_whence = SEEK_SET; 2074 lf.l_start = 0; 2075 lf.l_len = 0; 2076 lf.l_type = F_UNLCK; 2077 vp = fp->f_vnode; 2078 (void) VOP_ADVLOCK(vp, 2079 (caddr_t)p->p_leader, F_UNLCK, 2080 &lf, F_POSIX); 2081 FILEDESC_XLOCK(fdp); 2082 fdrop(fp, td); 2083 } 2084 } 2085retry: 2086 if (fdtol->fdl_refcount == 1) { 2087 if (fdp->fd_holdleaderscount > 0 && 2088 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2089 /* 2090 * close() or kern_dup() has cleared a reference 2091 * in a shared file descriptor table. 2092 */ 2093 fdp->fd_holdleaderswakeup = 1; 2094 sx_sleep(&fdp->fd_holdleaderscount, 2095 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2096 goto retry; 2097 } 2098 if (fdtol->fdl_holdcount > 0) { 2099 /* 2100 * Ensure that fdtol->fdl_leader remains 2101 * valid in closef(). 2102 */ 2103 fdtol->fdl_wakeup = 1; 2104 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2105 "fdlhold", 0); 2106 goto retry; 2107 } 2108 } 2109 fdtol->fdl_refcount--; 2110 if (fdtol->fdl_refcount == 0 && 2111 fdtol->fdl_holdcount == 0) { 2112 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2113 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2114 } else 2115 fdtol = NULL; 2116 p->p_fdtol = NULL; 2117 FILEDESC_XUNLOCK(fdp); 2118 if (fdtol != NULL) 2119 free(fdtol, M_FILEDESC_TO_LEADER); 2120} 2121 2122/* 2123 * Release a filedesc structure. 2124 */ 2125static void 2126fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2127{ 2128 struct filedesc0 *fdp0; 2129 struct freetable *ft, *tft; 2130 struct filedescent *fde; 2131 struct file *fp; 2132 int i; 2133 2134 for (i = 0; i <= fdp->fd_lastfile; i++) { 2135 fde = &fdp->fd_ofiles[i]; 2136 fp = fde->fde_file; 2137 if (fp != NULL) { 2138 fdefree_last(fde); 2139 if (needclose) 2140 (void) closef(fp, td); 2141 else 2142 fdrop(fp, td); 2143 } 2144 } 2145 2146 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2147 free(fdp->fd_map, M_FILEDESC); 2148 if (fdp->fd_nfiles > NDFILE) 2149 free(fdp->fd_files, M_FILEDESC); 2150 2151 fdp0 = (struct filedesc0 *)fdp; 2152 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2153 free(ft->ft_table, M_FILEDESC); 2154 2155 fddrop(fdp); 2156} 2157 2158void 2159fdescfree(struct thread *td) 2160{ 2161 struct proc *p; 2162 struct filedesc *fdp; 2163 struct vnode *cdir, *jdir, *rdir; 2164 2165 p = td->td_proc; 2166 fdp = p->p_fd; 2167 MPASS(fdp != NULL); 2168 2169#ifdef RACCT 2170 if (racct_enable) { 2171 PROC_LOCK(p); 2172 racct_set(p, RACCT_NOFILE, 0); 2173 PROC_UNLOCK(p); 2174 } 2175#endif 2176 2177 if (p->p_fdtol != NULL) 2178 fdclearlocks(td); 2179 2180 PROC_LOCK(p); 2181 p->p_fd = NULL; 2182 PROC_UNLOCK(p); 2183 2184 if (refcount_release(&fdp->fd_refcnt) == 0) 2185 return; 2186 2187 FILEDESC_XLOCK(fdp); 2188 cdir = fdp->fd_cdir; 2189 fdp->fd_cdir = NULL; 2190 rdir = fdp->fd_rdir; 2191 fdp->fd_rdir = NULL; 2192 jdir = fdp->fd_jdir; 2193 fdp->fd_jdir = NULL; 2194 FILEDESC_XUNLOCK(fdp); 2195 2196 if (cdir != NULL) 2197 vrele(cdir); 2198 if (rdir != NULL) 2199 vrele(rdir); 2200 if (jdir != NULL) 2201 vrele(jdir); 2202 2203 fdescfree_fds(td, fdp, 1); 2204} 2205 2206void 2207fdescfree_remapped(struct filedesc *fdp) 2208{ 2209 2210 if (fdp->fd_cdir != NULL) 2211 vrele(fdp->fd_cdir); 2212 if (fdp->fd_rdir != NULL) 2213 vrele(fdp->fd_rdir); 2214 if (fdp->fd_jdir != NULL) 2215 vrele(fdp->fd_jdir); 2216 2217 fdescfree_fds(curthread, fdp, 0); 2218} 2219 2220/* 2221 * For setugid programs, we don't want to people to use that setugidness 2222 * to generate error messages which write to a file which otherwise would 2223 * otherwise be off-limits to the process. We check for filesystems where 2224 * the vnode can change out from under us after execve (like [lin]procfs). 2225 * 2226 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2227 * sufficient. We also don't check for setugidness since we know we are. 2228 */ 2229static bool 2230is_unsafe(struct file *fp) 2231{ 2232 struct vnode *vp; 2233 2234 if (fp->f_type != DTYPE_VNODE) 2235 return (false); 2236 2237 vp = fp->f_vnode; 2238 return ((vp->v_vflag & VV_PROCDEP) != 0); 2239} 2240 2241/* 2242 * Make this setguid thing safe, if at all possible. 2243 */ 2244void 2245fdsetugidsafety(struct thread *td) 2246{ 2247 struct filedesc *fdp; 2248 struct file *fp; 2249 int i; 2250 2251 fdp = td->td_proc->p_fd; 2252 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2253 MPASS(fdp->fd_nfiles >= 3); 2254 for (i = 0; i <= 2; i++) { 2255 fp = fdp->fd_ofiles[i].fde_file; 2256 if (fp != NULL && is_unsafe(fp)) { 2257 FILEDESC_XLOCK(fdp); 2258 knote_fdclose(td, i); 2259 /* 2260 * NULL-out descriptor prior to close to avoid 2261 * a race while close blocks. 2262 */ 2263 fdfree(fdp, i); 2264 FILEDESC_XUNLOCK(fdp); 2265 (void) closef(fp, td); 2266 } 2267 } 2268} 2269 2270/* 2271 * If a specific file object occupies a specific file descriptor, close the 2272 * file descriptor entry and drop a reference on the file object. This is a 2273 * convenience function to handle a subsequent error in a function that calls 2274 * falloc() that handles the race that another thread might have closed the 2275 * file descriptor out from under the thread creating the file object. 2276 */ 2277void 2278fdclose(struct thread *td, struct file *fp, int idx) 2279{ 2280 struct filedesc *fdp = td->td_proc->p_fd; 2281 2282 FILEDESC_XLOCK(fdp); 2283 if (fdp->fd_ofiles[idx].fde_file == fp) { 2284 fdfree(fdp, idx); 2285 FILEDESC_XUNLOCK(fdp); 2286 fdrop(fp, td); 2287 } else 2288 FILEDESC_XUNLOCK(fdp); 2289} 2290 2291/* 2292 * Close any files on exec? 2293 */ 2294void 2295fdcloseexec(struct thread *td) 2296{ 2297 struct filedesc *fdp; 2298 struct filedescent *fde; 2299 struct file *fp; 2300 int i; 2301 2302 fdp = td->td_proc->p_fd; 2303 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2304 for (i = 0; i <= fdp->fd_lastfile; i++) { 2305 fde = &fdp->fd_ofiles[i]; 2306 fp = fde->fde_file; 2307 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2308 (fde->fde_flags & UF_EXCLOSE))) { 2309 FILEDESC_XLOCK(fdp); 2310 fdfree(fdp, i); 2311 (void) closefp(fdp, i, fp, td, 0); 2312 FILEDESC_UNLOCK_ASSERT(fdp); 2313 } 2314 } 2315} 2316 2317/* 2318 * It is unsafe for set[ug]id processes to be started with file 2319 * descriptors 0..2 closed, as these descriptors are given implicit 2320 * significance in the Standard C library. fdcheckstd() will create a 2321 * descriptor referencing /dev/null for each of stdin, stdout, and 2322 * stderr that is not already open. 2323 */ 2324int 2325fdcheckstd(struct thread *td) 2326{ 2327 struct filedesc *fdp; 2328 register_t save; 2329 int i, error, devnull; 2330 2331 fdp = td->td_proc->p_fd; 2332 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2333 MPASS(fdp->fd_nfiles >= 3); 2334 devnull = -1; 2335 for (i = 0; i <= 2; i++) { 2336 if (fdp->fd_ofiles[i].fde_file != NULL) 2337 continue; 2338 2339 save = td->td_retval[0]; 2340 if (devnull != -1) { 2341 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2342 } else { 2343 error = kern_openat(td, AT_FDCWD, "/dev/null", 2344 UIO_SYSSPACE, O_RDWR, 0); 2345 if (error == 0) { 2346 devnull = td->td_retval[0]; 2347 KASSERT(devnull == i, ("we didn't get our fd")); 2348 } 2349 } 2350 td->td_retval[0] = save; 2351 if (error != 0) 2352 return (error); 2353 } 2354 return (0); 2355} 2356 2357/* 2358 * Internal form of close. Decrement reference count on file structure. 2359 * Note: td may be NULL when closing a file that was being passed in a 2360 * message. 2361 * 2362 * XXXRW: Giant is not required for the caller, but often will be held; this 2363 * makes it moderately likely the Giant will be recursed in the VFS case. 2364 */ 2365int 2366closef(struct file *fp, struct thread *td) 2367{ 2368 struct vnode *vp; 2369 struct flock lf; 2370 struct filedesc_to_leader *fdtol; 2371 struct filedesc *fdp; 2372 2373 /* 2374 * POSIX record locking dictates that any close releases ALL 2375 * locks owned by this process. This is handled by setting 2376 * a flag in the unlock to free ONLY locks obeying POSIX 2377 * semantics, and not to free BSD-style file locks. 2378 * If the descriptor was in a message, POSIX-style locks 2379 * aren't passed with the descriptor, and the thread pointer 2380 * will be NULL. Callers should be careful only to pass a 2381 * NULL thread pointer when there really is no owning 2382 * context that might have locks, or the locks will be 2383 * leaked. 2384 */ 2385 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2386 vp = fp->f_vnode; 2387 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2388 lf.l_whence = SEEK_SET; 2389 lf.l_start = 0; 2390 lf.l_len = 0; 2391 lf.l_type = F_UNLCK; 2392 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2393 F_UNLCK, &lf, F_POSIX); 2394 } 2395 fdtol = td->td_proc->p_fdtol; 2396 if (fdtol != NULL) { 2397 /* 2398 * Handle special case where file descriptor table is 2399 * shared between multiple process leaders. 2400 */ 2401 fdp = td->td_proc->p_fd; 2402 FILEDESC_XLOCK(fdp); 2403 for (fdtol = fdtol->fdl_next; 2404 fdtol != td->td_proc->p_fdtol; 2405 fdtol = fdtol->fdl_next) { 2406 if ((fdtol->fdl_leader->p_flag & 2407 P_ADVLOCK) == 0) 2408 continue; 2409 fdtol->fdl_holdcount++; 2410 FILEDESC_XUNLOCK(fdp); 2411 lf.l_whence = SEEK_SET; 2412 lf.l_start = 0; 2413 lf.l_len = 0; 2414 lf.l_type = F_UNLCK; 2415 vp = fp->f_vnode; 2416 (void) VOP_ADVLOCK(vp, 2417 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2418 F_POSIX); 2419 FILEDESC_XLOCK(fdp); 2420 fdtol->fdl_holdcount--; 2421 if (fdtol->fdl_holdcount == 0 && 2422 fdtol->fdl_wakeup != 0) { 2423 fdtol->fdl_wakeup = 0; 2424 wakeup(fdtol); 2425 } 2426 } 2427 FILEDESC_XUNLOCK(fdp); 2428 } 2429 } 2430 return (fdrop(fp, td)); 2431} 2432 2433/* 2434 * Initialize the file pointer with the specified properties. 2435 * 2436 * The ops are set with release semantics to be certain that the flags, type, 2437 * and data are visible when ops is. This is to prevent ops methods from being 2438 * called with bad data. 2439 */ 2440void 2441finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2442{ 2443 fp->f_data = data; 2444 fp->f_flag = flag; 2445 fp->f_type = type; 2446 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2447} 2448 2449int 2450fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2451 struct file **fpp, struct filecaps *havecapsp) 2452{ 2453 struct filedescent *fde; 2454 int error; 2455 2456 FILEDESC_LOCK_ASSERT(fdp); 2457 2458 fde = fdeget_locked(fdp, fd); 2459 if (fde == NULL) { 2460 error = EBADF; 2461 goto out; 2462 } 2463 2464#ifdef CAPABILITIES 2465 error = cap_check(cap_rights_fde(fde), needrightsp); 2466 if (error != 0) 2467 goto out; 2468#endif 2469 2470 if (havecapsp != NULL) 2471 filecaps_copy(&fde->fde_caps, havecapsp, true); 2472 2473 *fpp = fde->fde_file; 2474 2475 error = 0; 2476out: 2477 return (error); 2478} 2479 2480int 2481fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2482 struct file **fpp, struct filecaps *havecapsp) 2483{ 2484 struct filedesc *fdp = td->td_proc->p_fd; 2485 int error; 2486#ifndef CAPABILITIES 2487 error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); 2488 if (error == 0 && havecapsp != NULL) 2489 filecaps_fill(havecapsp); 2490#else 2491 struct file *fp; 2492 seq_t seq; 2493 2494 for (;;) { 2495 error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); 2496 if (error != 0) 2497 return (error); 2498 2499 if (havecapsp != NULL) { 2500 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2501 havecapsp, false)) { 2502 fdrop(fp, td); 2503 goto get_locked; 2504 } 2505 } 2506 2507 if (!fd_modified(fdp, fd, seq)) 2508 break; 2509 fdrop(fp, td); 2510 } 2511 2512 *fpp = fp; 2513 return (0); 2514 2515get_locked: 2516 FILEDESC_SLOCK(fdp); 2517 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2518 if (error == 0) 2519 fhold(*fpp); 2520 FILEDESC_SUNLOCK(fdp); 2521#endif 2522 return (error); 2523} 2524 2525int 2526fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2527 struct file **fpp, seq_t *seqp) 2528{ 2529#ifdef CAPABILITIES 2530 struct filedescent *fde; 2531#endif 2532 struct fdescenttbl *fdt; 2533 struct file *fp; 2534 u_int count; 2535#ifdef CAPABILITIES 2536 seq_t seq; 2537 cap_rights_t haverights; 2538 int error; 2539#endif 2540 2541 fdt = fdp->fd_files; 2542 if ((u_int)fd >= fdt->fdt_nfiles) 2543 return (EBADF); 2544 /* 2545 * Fetch the descriptor locklessly. We avoid fdrop() races by 2546 * never raising a refcount above 0. To accomplish this we have 2547 * to use a cmpset loop rather than an atomic_add. The descriptor 2548 * must be re-verified once we acquire a reference to be certain 2549 * that the identity is still correct and we did not lose a race 2550 * due to preemption. 2551 */ 2552 for (;;) { 2553#ifdef CAPABILITIES 2554 seq = seq_read(fd_seq(fdt, fd)); 2555 fde = &fdt->fdt_ofiles[fd]; 2556 haverights = *cap_rights_fde(fde); 2557 fp = fde->fde_file; 2558 if (!seq_consistent(fd_seq(fdt, fd), seq)) 2559 continue; 2560#else 2561 fp = fdt->fdt_ofiles[fd].fde_file; 2562#endif 2563 if (fp == NULL) 2564 return (EBADF); 2565#ifdef CAPABILITIES 2566 error = cap_check(&haverights, needrightsp); 2567 if (error != 0) 2568 return (error); 2569#endif 2570 count = fp->f_count; 2571 retry: 2572 if (count == 0) { 2573 /* 2574 * Force a reload. Other thread could reallocate the 2575 * table before this fd was closed, so it possible that 2576 * there is a stale fp pointer in cached version. 2577 */ 2578 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2579 continue; 2580 } 2581 /* 2582 * Use an acquire barrier to force re-reading of fdt so it is 2583 * refreshed for verification. 2584 */ 2585 if (atomic_fcmpset_acq_int(&fp->f_count, &count, count + 1) == 0) 2586 goto retry; 2587 fdt = fdp->fd_files; 2588#ifdef CAPABILITIES 2589 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2590#else 2591 if (fp == fdt->fdt_ofiles[fd].fde_file) 2592#endif 2593 break; 2594 fdrop(fp, curthread); 2595 } 2596 *fpp = fp; 2597 if (seqp != NULL) { 2598#ifdef CAPABILITIES 2599 *seqp = seq; 2600#endif 2601 } 2602 return (0); 2603} 2604 2605/* 2606 * Extract the file pointer associated with the specified descriptor for the 2607 * current user process. 2608 * 2609 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2610 * returned. 2611 * 2612 * File's rights will be checked against the capability rights mask. 2613 * 2614 * If an error occurred the non-zero error is returned and *fpp is set to 2615 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2616 * responsible for fdrop(). 2617 */ 2618static __inline int 2619_fget(struct thread *td, int fd, struct file **fpp, int flags, 2620 cap_rights_t *needrightsp, seq_t *seqp) 2621{ 2622 struct filedesc *fdp; 2623 struct file *fp; 2624 int error; 2625 2626 *fpp = NULL; 2627 fdp = td->td_proc->p_fd; 2628 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2629 if (error != 0) 2630 return (error); 2631 if (fp->f_ops == &badfileops) { 2632 fdrop(fp, td); 2633 return (EBADF); 2634 } 2635 2636 /* 2637 * FREAD and FWRITE failure return EBADF as per POSIX. 2638 */ 2639 error = 0; 2640 switch (flags) { 2641 case FREAD: 2642 case FWRITE: 2643 if ((fp->f_flag & flags) == 0) 2644 error = EBADF; 2645 break; 2646 case FEXEC: 2647 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2648 ((fp->f_flag & FWRITE) != 0)) 2649 error = EBADF; 2650 break; 2651 case 0: 2652 break; 2653 default: 2654 KASSERT(0, ("wrong flags")); 2655 } 2656 2657 if (error != 0) { 2658 fdrop(fp, td); 2659 return (error); 2660 } 2661 2662 *fpp = fp; 2663 return (0); 2664} 2665 2666int 2667fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2668{ 2669 2670 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2671} 2672 2673int 2674fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2675 struct file **fpp) 2676{ 2677 int error; 2678#ifndef CAPABILITIES 2679 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2680 if (maxprotp != NULL) 2681 *maxprotp = VM_PROT_ALL; 2682#else 2683 struct filedesc *fdp = td->td_proc->p_fd; 2684 seq_t seq; 2685 2686 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2687 for (;;) { 2688 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2689 if (error != 0) 2690 return (error); 2691 /* 2692 * If requested, convert capability rights to access flags. 2693 */ 2694 if (maxprotp != NULL) 2695 *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); 2696 if (!fd_modified(fdp, fd, seq)) 2697 break; 2698 fdrop(*fpp, td); 2699 } 2700#endif 2701 return (error); 2702} 2703 2704int 2705fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2706{ 2707 2708 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2709} 2710 2711int 2712fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2713{ 2714 2715 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2716} 2717 2718int 2719fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2720 struct file **fpp) 2721{ 2722 struct filedesc *fdp = td->td_proc->p_fd; 2723#ifndef CAPABILITIES 2724 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2725#else 2726 int error; 2727 seq_t seq; 2728 2729 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2730 for (;;) { 2731 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2732 if (error != 0) 2733 return (error); 2734 error = cap_fcntl_check(fdp, fd, needfcntl); 2735 if (!fd_modified(fdp, fd, seq)) 2736 break; 2737 fdrop(*fpp, td); 2738 } 2739 if (error != 0) { 2740 fdrop(*fpp, td); 2741 *fpp = NULL; 2742 } 2743 return (error); 2744#endif 2745} 2746 2747/* 2748 * Like fget() but loads the underlying vnode, or returns an error if the 2749 * descriptor does not represent a vnode. Note that pipes use vnodes but 2750 * never have VM objects. The returned vnode will be vref()'d. 2751 * 2752 * XXX: what about the unused flags ? 2753 */ 2754static __inline int 2755_fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2756 struct vnode **vpp) 2757{ 2758 struct file *fp; 2759 int error; 2760 2761 *vpp = NULL; 2762 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2763 if (error != 0) 2764 return (error); 2765 if (fp->f_vnode == NULL) { 2766 error = EINVAL; 2767 } else { 2768 *vpp = fp->f_vnode; 2769 vrefact(*vpp); 2770 } 2771 fdrop(fp, td); 2772 2773 return (error); 2774} 2775 2776int 2777fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2778{ 2779 2780 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2781} 2782 2783int 2784fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2785 struct filecaps *havecaps, struct vnode **vpp) 2786{ 2787 struct filedesc *fdp; 2788 struct filecaps caps; 2789 struct file *fp; 2790 int error; 2791 2792 fdp = td->td_proc->p_fd; 2793 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 2794 if (error != 0) 2795 return (error); 2796 if (fp->f_ops == &badfileops) { 2797 error = EBADF; 2798 goto out; 2799 } 2800 if (fp->f_vnode == NULL) { 2801 error = EINVAL; 2802 goto out; 2803 } 2804 2805 *havecaps = caps; 2806 *vpp = fp->f_vnode; 2807 vrefact(*vpp); 2808 2809 return (0); 2810out: 2811 filecaps_free(&caps); 2812 return (error); 2813} 2814 2815int 2816fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2817{ 2818 2819 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2820} 2821 2822int 2823fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2824{ 2825 2826 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2827} 2828 2829#ifdef notyet 2830int 2831fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2832 struct vnode **vpp) 2833{ 2834 2835 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2836} 2837#endif 2838 2839/* 2840 * Handle the last reference to a file being closed. 2841 */ 2842int 2843_fdrop(struct file *fp, struct thread *td) 2844{ 2845 int error; 2846 2847 if (fp->f_count != 0) 2848 panic("fdrop: count %d", fp->f_count); 2849 error = fo_close(fp, td); 2850 atomic_subtract_int(&openfiles, 1); 2851 crfree(fp->f_cred); 2852 free(fp->f_advice, M_FADVISE); 2853 uma_zfree(file_zone, fp); 2854 2855 return (error); 2856} 2857 2858/* 2859 * Apply an advisory lock on a file descriptor. 2860 * 2861 * Just attempt to get a record lock of the requested type on the entire file 2862 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2863 */ 2864#ifndef _SYS_SYSPROTO_H_ 2865struct flock_args { 2866 int fd; 2867 int how; 2868}; 2869#endif 2870/* ARGSUSED */ 2871int 2872sys_flock(struct thread *td, struct flock_args *uap) 2873{ 2874 struct file *fp; 2875 struct vnode *vp; 2876 struct flock lf; 2877 cap_rights_t rights; 2878 int error; 2879 2880 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2881 if (error != 0) 2882 return (error); 2883 if (fp->f_type != DTYPE_VNODE) { 2884 fdrop(fp, td); 2885 return (EOPNOTSUPP); 2886 } 2887 2888 vp = fp->f_vnode; 2889 lf.l_whence = SEEK_SET; 2890 lf.l_start = 0; 2891 lf.l_len = 0; 2892 if (uap->how & LOCK_UN) { 2893 lf.l_type = F_UNLCK; 2894 atomic_clear_int(&fp->f_flag, FHASLOCK); 2895 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2896 goto done2; 2897 } 2898 if (uap->how & LOCK_EX) 2899 lf.l_type = F_WRLCK; 2900 else if (uap->how & LOCK_SH) 2901 lf.l_type = F_RDLCK; 2902 else { 2903 error = EBADF; 2904 goto done2; 2905 } 2906 atomic_set_int(&fp->f_flag, FHASLOCK); 2907 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2908 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2909done2: 2910 fdrop(fp, td); 2911 return (error); 2912} 2913/* 2914 * Duplicate the specified descriptor to a free descriptor. 2915 */ 2916int 2917dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2918 int openerror, int *indxp) 2919{ 2920 struct filedescent *newfde, *oldfde; 2921 struct file *fp; 2922 int error, indx; 2923 2924 KASSERT(openerror == ENODEV || openerror == ENXIO, 2925 ("unexpected error %d in %s", openerror, __func__)); 2926 2927 /* 2928 * If the to-be-dup'd fd number is greater than the allowed number 2929 * of file descriptors, or the fd to be dup'd has already been 2930 * closed, then reject. 2931 */ 2932 FILEDESC_XLOCK(fdp); 2933 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2934 FILEDESC_XUNLOCK(fdp); 2935 return (EBADF); 2936 } 2937 2938 error = fdalloc(td, 0, &indx); 2939 if (error != 0) { 2940 FILEDESC_XUNLOCK(fdp); 2941 return (error); 2942 } 2943 2944 /* 2945 * There are two cases of interest here. 2946 * 2947 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2948 * 2949 * For ENXIO steal away the file structure from (dfd) and store it in 2950 * (indx). (dfd) is effectively closed by this operation. 2951 */ 2952 switch (openerror) { 2953 case ENODEV: 2954 /* 2955 * Check that the mode the file is being opened for is a 2956 * subset of the mode of the existing descriptor. 2957 */ 2958 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2959 fdunused(fdp, indx); 2960 FILEDESC_XUNLOCK(fdp); 2961 return (EACCES); 2962 } 2963 fhold(fp); 2964 newfde = &fdp->fd_ofiles[indx]; 2965 oldfde = &fdp->fd_ofiles[dfd]; 2966#ifdef CAPABILITIES 2967 seq_write_begin(&newfde->fde_seq); 2968#endif 2969 memcpy(newfde, oldfde, fde_change_size); 2970 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps, true); 2971#ifdef CAPABILITIES 2972 seq_write_end(&newfde->fde_seq); 2973#endif 2974 break; 2975 case ENXIO: 2976 /* 2977 * Steal away the file pointer from dfd and stuff it into indx. 2978 */ 2979 newfde = &fdp->fd_ofiles[indx]; 2980 oldfde = &fdp->fd_ofiles[dfd]; 2981#ifdef CAPABILITIES 2982 seq_write_begin(&newfde->fde_seq); 2983#endif 2984 memcpy(newfde, oldfde, fde_change_size); 2985 oldfde->fde_file = NULL; 2986 fdunused(fdp, dfd); 2987#ifdef CAPABILITIES 2988 seq_write_end(&newfde->fde_seq); 2989#endif 2990 break; 2991 } 2992 FILEDESC_XUNLOCK(fdp); 2993 *indxp = indx; 2994 return (0); 2995} 2996 2997/* 2998 * This sysctl determines if we will allow a process to chroot(2) if it 2999 * has a directory open: 3000 * 0: disallowed for all processes. 3001 * 1: allowed for processes that were not already chroot(2)'ed. 3002 * 2: allowed for all processes. 3003 */ 3004 3005static int chroot_allow_open_directories = 1; 3006 3007SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3008 &chroot_allow_open_directories, 0, 3009 "Allow a process to chroot(2) if it has a directory open"); 3010 3011/* 3012 * Helper function for raised chroot(2) security function: Refuse if 3013 * any filedescriptors are open directories. 3014 */ 3015static int 3016chroot_refuse_vdir_fds(struct filedesc *fdp) 3017{ 3018 struct vnode *vp; 3019 struct file *fp; 3020 int fd; 3021 3022 FILEDESC_LOCK_ASSERT(fdp); 3023 3024 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3025 fp = fget_locked(fdp, fd); 3026 if (fp == NULL) 3027 continue; 3028 if (fp->f_type == DTYPE_VNODE) { 3029 vp = fp->f_vnode; 3030 if (vp->v_type == VDIR) 3031 return (EPERM); 3032 } 3033 } 3034 return (0); 3035} 3036 3037/* 3038 * Common routine for kern_chroot() and jail_attach(). The caller is 3039 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3040 * authorize this operation. 3041 */ 3042int 3043pwd_chroot(struct thread *td, struct vnode *vp) 3044{ 3045 struct filedesc *fdp; 3046 struct vnode *oldvp; 3047 int error; 3048 3049 fdp = td->td_proc->p_fd; 3050 FILEDESC_XLOCK(fdp); 3051 if (chroot_allow_open_directories == 0 || 3052 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3053 error = chroot_refuse_vdir_fds(fdp); 3054 if (error != 0) { 3055 FILEDESC_XUNLOCK(fdp); 3056 return (error); 3057 } 3058 } 3059 oldvp = fdp->fd_rdir; 3060 vrefact(vp); 3061 fdp->fd_rdir = vp; 3062 if (fdp->fd_jdir == NULL) { 3063 vrefact(vp); 3064 fdp->fd_jdir = vp; 3065 } 3066 FILEDESC_XUNLOCK(fdp); 3067 vrele(oldvp); 3068 return (0); 3069} 3070 3071void 3072pwd_chdir(struct thread *td, struct vnode *vp) 3073{ 3074 struct filedesc *fdp; 3075 struct vnode *oldvp; 3076 3077 fdp = td->td_proc->p_fd; 3078 FILEDESC_XLOCK(fdp); 3079 VNASSERT(vp->v_usecount > 0, vp, 3080 ("chdir to a vnode with zero usecount")); 3081 oldvp = fdp->fd_cdir; 3082 fdp->fd_cdir = vp; 3083 FILEDESC_XUNLOCK(fdp); 3084 vrele(oldvp); 3085} 3086 3087/* 3088 * Scan all active processes and prisons to see if any of them have a current 3089 * or root directory of `olddp'. If so, replace them with the new mount point. 3090 */ 3091void 3092mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3093{ 3094 struct filedesc *fdp; 3095 struct prison *pr; 3096 struct proc *p; 3097 int nrele; 3098 3099 if (vrefcnt(olddp) == 1) 3100 return; 3101 nrele = 0; 3102 sx_slock(&allproc_lock); 3103 FOREACH_PROC_IN_SYSTEM(p) { 3104 PROC_LOCK(p); 3105 fdp = fdhold(p); 3106 PROC_UNLOCK(p); 3107 if (fdp == NULL) 3108 continue; 3109 FILEDESC_XLOCK(fdp); 3110 if (fdp->fd_cdir == olddp) { 3111 vrefact(newdp); 3112 fdp->fd_cdir = newdp; 3113 nrele++; 3114 } 3115 if (fdp->fd_rdir == olddp) { 3116 vrefact(newdp); 3117 fdp->fd_rdir = newdp; 3118 nrele++; 3119 } 3120 if (fdp->fd_jdir == olddp) { 3121 vrefact(newdp); 3122 fdp->fd_jdir = newdp; 3123 nrele++; 3124 } 3125 FILEDESC_XUNLOCK(fdp); 3126 fddrop(fdp); 3127 } 3128 sx_sunlock(&allproc_lock); 3129 if (rootvnode == olddp) { 3130 vrefact(newdp); 3131 rootvnode = newdp; 3132 nrele++; 3133 } 3134 mtx_lock(&prison0.pr_mtx); 3135 if (prison0.pr_root == olddp) { 3136 vrefact(newdp); 3137 prison0.pr_root = newdp; 3138 nrele++; 3139 } 3140 mtx_unlock(&prison0.pr_mtx); 3141 sx_slock(&allprison_lock); 3142 TAILQ_FOREACH(pr, &allprison, pr_list) { 3143 mtx_lock(&pr->pr_mtx); 3144 if (pr->pr_root == olddp) { 3145 vrefact(newdp); 3146 pr->pr_root = newdp; 3147 nrele++; 3148 } 3149 mtx_unlock(&pr->pr_mtx); 3150 } 3151 sx_sunlock(&allprison_lock); 3152 while (nrele--) 3153 vrele(olddp); 3154} 3155 3156struct filedesc_to_leader * 3157filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3158{ 3159 struct filedesc_to_leader *fdtol; 3160 3161 fdtol = malloc(sizeof(struct filedesc_to_leader), 3162 M_FILEDESC_TO_LEADER, M_WAITOK); 3163 fdtol->fdl_refcount = 1; 3164 fdtol->fdl_holdcount = 0; 3165 fdtol->fdl_wakeup = 0; 3166 fdtol->fdl_leader = leader; 3167 if (old != NULL) { 3168 FILEDESC_XLOCK(fdp); 3169 fdtol->fdl_next = old->fdl_next; 3170 fdtol->fdl_prev = old; 3171 old->fdl_next = fdtol; 3172 fdtol->fdl_next->fdl_prev = fdtol; 3173 FILEDESC_XUNLOCK(fdp); 3174 } else { 3175 fdtol->fdl_next = fdtol; 3176 fdtol->fdl_prev = fdtol; 3177 } 3178 return (fdtol); 3179} 3180 3181static int 3182sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3183{ 3184 struct filedesc *fdp; 3185 int i, count, slots; 3186 3187 if (*(int *)arg1 != 0) 3188 return (EINVAL); 3189 3190 fdp = curproc->p_fd; 3191 count = 0; 3192 FILEDESC_SLOCK(fdp); 3193 slots = NDSLOTS(fdp->fd_lastfile + 1); 3194 for (i = 0; i < slots; i++) 3195 count += bitcountl(fdp->fd_map[i]); 3196 FILEDESC_SUNLOCK(fdp); 3197 3198 return (SYSCTL_OUT(req, &count, sizeof(count))); 3199} 3200 3201static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3202 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3203 "Number of open file descriptors"); 3204 3205/* 3206 * Get file structures globally. 3207 */ 3208static int 3209sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3210{ 3211 struct xfile xf; 3212 struct filedesc *fdp; 3213 struct file *fp; 3214 struct proc *p; 3215 int error, n; 3216 3217 error = sysctl_wire_old_buffer(req, 0); 3218 if (error != 0) 3219 return (error); 3220 if (req->oldptr == NULL) { 3221 n = 0; 3222 sx_slock(&allproc_lock); 3223 FOREACH_PROC_IN_SYSTEM(p) { 3224 PROC_LOCK(p); 3225 if (p->p_state == PRS_NEW) { 3226 PROC_UNLOCK(p); 3227 continue; 3228 } 3229 fdp = fdhold(p); 3230 PROC_UNLOCK(p); 3231 if (fdp == NULL) 3232 continue; 3233 /* overestimates sparse tables. */ 3234 if (fdp->fd_lastfile > 0) 3235 n += fdp->fd_lastfile; 3236 fddrop(fdp); 3237 } 3238 sx_sunlock(&allproc_lock); 3239 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3240 } 3241 error = 0; 3242 bzero(&xf, sizeof(xf)); 3243 xf.xf_size = sizeof(xf); 3244 sx_slock(&allproc_lock); 3245 FOREACH_PROC_IN_SYSTEM(p) { 3246 PROC_LOCK(p); 3247 if (p->p_state == PRS_NEW) { 3248 PROC_UNLOCK(p); 3249 continue; 3250 } 3251 if (p_cansee(req->td, p) != 0) { 3252 PROC_UNLOCK(p); 3253 continue; 3254 } 3255 xf.xf_pid = p->p_pid; 3256 xf.xf_uid = p->p_ucred->cr_uid; 3257 fdp = fdhold(p); 3258 PROC_UNLOCK(p); 3259 if (fdp == NULL) 3260 continue; 3261 FILEDESC_SLOCK(fdp); 3262 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3263 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3264 continue; 3265 xf.xf_fd = n; 3266 xf.xf_file = fp; 3267 xf.xf_data = fp->f_data; 3268 xf.xf_vnode = fp->f_vnode; 3269 xf.xf_type = fp->f_type; 3270 xf.xf_count = fp->f_count; 3271 xf.xf_msgcount = 0; 3272 xf.xf_offset = foffset_get(fp); 3273 xf.xf_flag = fp->f_flag; 3274 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3275 if (error) 3276 break; 3277 } 3278 FILEDESC_SUNLOCK(fdp); 3279 fddrop(fdp); 3280 if (error) 3281 break; 3282 } 3283 sx_sunlock(&allproc_lock); 3284 return (error); 3285} 3286 3287SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3288 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3289 3290#ifdef KINFO_FILE_SIZE 3291CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3292#endif 3293 3294static int 3295xlate_fflags(int fflags) 3296{ 3297 static const struct { 3298 int fflag; 3299 int kf_fflag; 3300 } fflags_table[] = { 3301 { FAPPEND, KF_FLAG_APPEND }, 3302 { FASYNC, KF_FLAG_ASYNC }, 3303 { FFSYNC, KF_FLAG_FSYNC }, 3304 { FHASLOCK, KF_FLAG_HASLOCK }, 3305 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3306 { FREAD, KF_FLAG_READ }, 3307 { FWRITE, KF_FLAG_WRITE }, 3308 { O_CREAT, KF_FLAG_CREAT }, 3309 { O_DIRECT, KF_FLAG_DIRECT }, 3310 { O_EXCL, KF_FLAG_EXCL }, 3311 { O_EXEC, KF_FLAG_EXEC }, 3312 { O_EXLOCK, KF_FLAG_EXLOCK }, 3313 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3314 { O_SHLOCK, KF_FLAG_SHLOCK }, 3315 { O_TRUNC, KF_FLAG_TRUNC } 3316 }; 3317 unsigned int i; 3318 int kflags; 3319 3320 kflags = 0; 3321 for (i = 0; i < nitems(fflags_table); i++) 3322 if (fflags & fflags_table[i].fflag) 3323 kflags |= fflags_table[i].kf_fflag; 3324 return (kflags); 3325} 3326 3327/* Trim unused data from kf_path by truncating the structure size. */ 3328static void 3329pack_kinfo(struct kinfo_file *kif) 3330{ 3331 3332 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3333 strlen(kif->kf_path) + 1; 3334 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3335} 3336 3337static void 3338export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3339 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3340{ 3341 int error; 3342 3343 bzero(kif, sizeof(*kif)); 3344 3345 /* Set a default type to allow for empty fill_kinfo() methods. */ 3346 kif->kf_type = KF_TYPE_UNKNOWN; 3347 kif->kf_flags = xlate_fflags(fp->f_flag); 3348 if (rightsp != NULL) 3349 kif->kf_cap_rights = *rightsp; 3350 else 3351 cap_rights_init(&kif->kf_cap_rights); 3352 kif->kf_fd = fd; 3353 kif->kf_ref_count = fp->f_count; 3354 kif->kf_offset = foffset_get(fp); 3355 3356 /* 3357 * This may drop the filedesc lock, so the 'fp' cannot be 3358 * accessed after this call. 3359 */ 3360 error = fo_fill_kinfo(fp, kif, fdp); 3361 if (error == 0) 3362 kif->kf_status |= KF_ATTR_VALID; 3363 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3364 pack_kinfo(kif); 3365 else 3366 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3367} 3368 3369static void 3370export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3371 struct kinfo_file *kif, int flags) 3372{ 3373 int error; 3374 3375 bzero(kif, sizeof(*kif)); 3376 3377 kif->kf_type = KF_TYPE_VNODE; 3378 error = vn_fill_kinfo_vnode(vp, kif); 3379 if (error == 0) 3380 kif->kf_status |= KF_ATTR_VALID; 3381 kif->kf_flags = xlate_fflags(fflags); 3382 cap_rights_init(&kif->kf_cap_rights); 3383 kif->kf_fd = fd; 3384 kif->kf_ref_count = -1; 3385 kif->kf_offset = -1; 3386 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3387 pack_kinfo(kif); 3388 else 3389 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3390 vrele(vp); 3391} 3392 3393struct export_fd_buf { 3394 struct filedesc *fdp; 3395 struct sbuf *sb; 3396 ssize_t remainder; 3397 struct kinfo_file kif; 3398 int flags; 3399}; 3400 3401static int 3402export_kinfo_to_sb(struct export_fd_buf *efbuf) 3403{ 3404 struct kinfo_file *kif; 3405 3406 kif = &efbuf->kif; 3407 if (efbuf->remainder != -1) { 3408 if (efbuf->remainder < kif->kf_structsize) { 3409 /* Terminate export. */ 3410 efbuf->remainder = 0; 3411 return (0); 3412 } 3413 efbuf->remainder -= kif->kf_structsize; 3414 } 3415 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3416} 3417 3418static int 3419export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3420 struct export_fd_buf *efbuf) 3421{ 3422 int error; 3423 3424 if (efbuf->remainder == 0) 3425 return (0); 3426 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3427 efbuf->flags); 3428 FILEDESC_SUNLOCK(efbuf->fdp); 3429 error = export_kinfo_to_sb(efbuf); 3430 FILEDESC_SLOCK(efbuf->fdp); 3431 return (error); 3432} 3433 3434static int 3435export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3436 struct export_fd_buf *efbuf) 3437{ 3438 int error; 3439 3440 if (efbuf->remainder == 0) 3441 return (0); 3442 if (efbuf->fdp != NULL) 3443 FILEDESC_SUNLOCK(efbuf->fdp); 3444 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3445 error = export_kinfo_to_sb(efbuf); 3446 if (efbuf->fdp != NULL) 3447 FILEDESC_SLOCK(efbuf->fdp); 3448 return (error); 3449} 3450 3451/* 3452 * Store a process file descriptor information to sbuf. 3453 * 3454 * Takes a locked proc as argument, and returns with the proc unlocked. 3455 */ 3456int 3457kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3458 int flags) 3459{ 3460 struct file *fp; 3461 struct filedesc *fdp; 3462 struct export_fd_buf *efbuf; 3463 struct vnode *cttyvp, *textvp, *tracevp; 3464 int error, i; 3465 cap_rights_t rights; 3466 3467 PROC_LOCK_ASSERT(p, MA_OWNED); 3468 3469 /* ktrace vnode */ 3470 tracevp = p->p_tracevp; 3471 if (tracevp != NULL) 3472 vrefact(tracevp); 3473 /* text vnode */ 3474 textvp = p->p_textvp; 3475 if (textvp != NULL) 3476 vrefact(textvp); 3477 /* Controlling tty. */ 3478 cttyvp = NULL; 3479 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3480 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3481 if (cttyvp != NULL) 3482 vrefact(cttyvp); 3483 } 3484 fdp = fdhold(p); 3485 PROC_UNLOCK(p); 3486 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3487 efbuf->fdp = NULL; 3488 efbuf->sb = sb; 3489 efbuf->remainder = maxlen; 3490 efbuf->flags = flags; 3491 if (tracevp != NULL) 3492 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3493 efbuf); 3494 if (textvp != NULL) 3495 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3496 if (cttyvp != NULL) 3497 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3498 efbuf); 3499 error = 0; 3500 if (fdp == NULL) 3501 goto fail; 3502 efbuf->fdp = fdp; 3503 FILEDESC_SLOCK(fdp); 3504 /* working directory */ 3505 if (fdp->fd_cdir != NULL) { 3506 vrefact(fdp->fd_cdir); 3507 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3508 } 3509 /* root directory */ 3510 if (fdp->fd_rdir != NULL) { 3511 vrefact(fdp->fd_rdir); 3512 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3513 } 3514 /* jail directory */ 3515 if (fdp->fd_jdir != NULL) { 3516 vrefact(fdp->fd_jdir); 3517 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3518 } 3519 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3520 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3521 continue; 3522#ifdef CAPABILITIES 3523 rights = *cap_rights(fdp, i); 3524#else /* !CAPABILITIES */ 3525 cap_rights_init(&rights); 3526#endif 3527 /* 3528 * Create sysctl entry. It is OK to drop the filedesc 3529 * lock inside of export_file_to_sb() as we will 3530 * re-validate and re-evaluate its properties when the 3531 * loop continues. 3532 */ 3533 error = export_file_to_sb(fp, i, &rights, efbuf); 3534 if (error != 0 || efbuf->remainder == 0) 3535 break; 3536 } 3537 FILEDESC_SUNLOCK(fdp); 3538 fddrop(fdp); 3539fail: 3540 free(efbuf, M_TEMP); 3541 return (error); 3542} 3543 3544#define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3545 3546/* 3547 * Get per-process file descriptors for use by procstat(1), et al. 3548 */ 3549static int 3550sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3551{ 3552 struct sbuf sb; 3553 struct proc *p; 3554 ssize_t maxlen; 3555 int error, error2, *name; 3556 3557 name = (int *)arg1; 3558 3559 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3560 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3561 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3562 if (error != 0) { 3563 sbuf_delete(&sb); 3564 return (error); 3565 } 3566 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3567 error = kern_proc_filedesc_out(p, &sb, maxlen, 3568 KERN_FILEDESC_PACK_KINFO); 3569 error2 = sbuf_finish(&sb); 3570 sbuf_delete(&sb); 3571 return (error != 0 ? error : error2); 3572} 3573 3574#ifdef KINFO_OFILE_SIZE 3575CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3576#endif 3577 3578#ifdef COMPAT_FREEBSD7 3579static void 3580kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3581{ 3582 3583 okif->kf_structsize = sizeof(*okif); 3584 okif->kf_type = kif->kf_type; 3585 okif->kf_fd = kif->kf_fd; 3586 okif->kf_ref_count = kif->kf_ref_count; 3587 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3588 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3589 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3590 okif->kf_offset = kif->kf_offset; 3591 okif->kf_vnode_type = kif->kf_vnode_type; 3592 okif->kf_sock_domain = kif->kf_sock_domain; 3593 okif->kf_sock_type = kif->kf_sock_type; 3594 okif->kf_sock_protocol = kif->kf_sock_protocol; 3595 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3596 okif->kf_sa_local = kif->kf_sa_local; 3597 okif->kf_sa_peer = kif->kf_sa_peer; 3598} 3599 3600static int 3601export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3602 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3603{ 3604 int error; 3605 3606 vrefact(vp); 3607 FILEDESC_SUNLOCK(fdp); 3608 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3609 kinfo_to_okinfo(kif, okif); 3610 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3611 FILEDESC_SLOCK(fdp); 3612 return (error); 3613} 3614 3615/* 3616 * Get per-process file descriptors for use by procstat(1), et al. 3617 */ 3618static int 3619sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3620{ 3621 struct kinfo_ofile *okif; 3622 struct kinfo_file *kif; 3623 struct filedesc *fdp; 3624 int error, i, *name; 3625 struct file *fp; 3626 struct proc *p; 3627 3628 name = (int *)arg1; 3629 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3630 if (error != 0) 3631 return (error); 3632 fdp = fdhold(p); 3633 PROC_UNLOCK(p); 3634 if (fdp == NULL) 3635 return (ENOENT); 3636 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3637 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3638 FILEDESC_SLOCK(fdp); 3639 if (fdp->fd_cdir != NULL) 3640 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3641 okif, fdp, req); 3642 if (fdp->fd_rdir != NULL) 3643 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3644 okif, fdp, req); 3645 if (fdp->fd_jdir != NULL) 3646 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3647 okif, fdp, req); 3648 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3649 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3650 continue; 3651 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3652 KERN_FILEDESC_PACK_KINFO); 3653 FILEDESC_SUNLOCK(fdp); 3654 kinfo_to_okinfo(kif, okif); 3655 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3656 FILEDESC_SLOCK(fdp); 3657 if (error) 3658 break; 3659 } 3660 FILEDESC_SUNLOCK(fdp); 3661 fddrop(fdp); 3662 free(kif, M_TEMP); 3663 free(okif, M_TEMP); 3664 return (0); 3665} 3666 3667static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3668 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3669 "Process ofiledesc entries"); 3670#endif /* COMPAT_FREEBSD7 */ 3671 3672int 3673vntype_to_kinfo(int vtype) 3674{ 3675 struct { 3676 int vtype; 3677 int kf_vtype; 3678 } vtypes_table[] = { 3679 { VBAD, KF_VTYPE_VBAD }, 3680 { VBLK, KF_VTYPE_VBLK }, 3681 { VCHR, KF_VTYPE_VCHR }, 3682 { VDIR, KF_VTYPE_VDIR }, 3683 { VFIFO, KF_VTYPE_VFIFO }, 3684 { VLNK, KF_VTYPE_VLNK }, 3685 { VNON, KF_VTYPE_VNON }, 3686 { VREG, KF_VTYPE_VREG }, 3687 { VSOCK, KF_VTYPE_VSOCK } 3688 }; 3689 unsigned int i; 3690 3691 /* 3692 * Perform vtype translation. 3693 */ 3694 for (i = 0; i < nitems(vtypes_table); i++) 3695 if (vtypes_table[i].vtype == vtype) 3696 return (vtypes_table[i].kf_vtype); 3697 3698 return (KF_VTYPE_UNKNOWN); 3699} 3700 3701static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3702 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3703 "Process filedesc entries"); 3704 3705/* 3706 * Store a process current working directory information to sbuf. 3707 * 3708 * Takes a locked proc as argument, and returns with the proc unlocked. 3709 */ 3710int 3711kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3712{ 3713 struct filedesc *fdp; 3714 struct export_fd_buf *efbuf; 3715 int error; 3716 3717 PROC_LOCK_ASSERT(p, MA_OWNED); 3718 3719 fdp = fdhold(p); 3720 PROC_UNLOCK(p); 3721 if (fdp == NULL) 3722 return (EINVAL); 3723 3724 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3725 efbuf->fdp = fdp; 3726 efbuf->sb = sb; 3727 efbuf->remainder = maxlen; 3728 3729 FILEDESC_SLOCK(fdp); 3730 if (fdp->fd_cdir == NULL) 3731 error = EINVAL; 3732 else { 3733 vrefact(fdp->fd_cdir); 3734 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3735 FREAD, efbuf); 3736 } 3737 FILEDESC_SUNLOCK(fdp); 3738 fddrop(fdp); 3739 free(efbuf, M_TEMP); 3740 return (error); 3741} 3742 3743/* 3744 * Get per-process current working directory. 3745 */ 3746static int 3747sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3748{ 3749 struct sbuf sb; 3750 struct proc *p; 3751 ssize_t maxlen; 3752 int error, error2, *name; 3753 3754 name = (int *)arg1; 3755 3756 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3757 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3758 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3759 if (error != 0) { 3760 sbuf_delete(&sb); 3761 return (error); 3762 } 3763 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3764 error = kern_proc_cwd_out(p, &sb, maxlen); 3765 error2 = sbuf_finish(&sb); 3766 sbuf_delete(&sb); 3767 return (error != 0 ? error : error2); 3768} 3769 3770static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3771 sysctl_kern_proc_cwd, "Process current working directory"); 3772 3773#ifdef DDB 3774/* 3775 * For the purposes of debugging, generate a human-readable string for the 3776 * file type. 3777 */ 3778static const char * 3779file_type_to_name(short type) 3780{ 3781 3782 switch (type) { 3783 case 0: 3784 return ("zero"); 3785 case DTYPE_VNODE: 3786 return ("vnod"); 3787 case DTYPE_SOCKET: 3788 return ("sock"); 3789 case DTYPE_PIPE: 3790 return ("pipe"); 3791 case DTYPE_FIFO: 3792 return ("fifo"); 3793 case DTYPE_KQUEUE: 3794 return ("kque"); 3795 case DTYPE_CRYPTO: 3796 return ("crpt"); 3797 case DTYPE_MQUEUE: 3798 return ("mque"); 3799 case DTYPE_SHM: 3800 return ("shm"); 3801 case DTYPE_SEM: 3802 return ("ksem"); 3803 default: 3804 return ("unkn"); 3805 } 3806} 3807 3808/* 3809 * For the purposes of debugging, identify a process (if any, perhaps one of 3810 * many) that references the passed file in its file descriptor array. Return 3811 * NULL if none. 3812 */ 3813static struct proc * 3814file_to_first_proc(struct file *fp) 3815{ 3816 struct filedesc *fdp; 3817 struct proc *p; 3818 int n; 3819 3820 FOREACH_PROC_IN_SYSTEM(p) { 3821 if (p->p_state == PRS_NEW) 3822 continue; 3823 fdp = p->p_fd; 3824 if (fdp == NULL) 3825 continue; 3826 for (n = 0; n <= fdp->fd_lastfile; n++) { 3827 if (fp == fdp->fd_ofiles[n].fde_file) 3828 return (p); 3829 } 3830 } 3831 return (NULL); 3832} 3833 3834static void 3835db_print_file(struct file *fp, int header) 3836{ 3837 struct proc *p; 3838 3839 if (header) 3840 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3841 "File", "Type", "Data", "Flag", "GCFl", "Count", 3842 "MCount", "Vnode", "FPID", "FCmd"); 3843 p = file_to_first_proc(fp); 3844 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3845 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3846 0, fp->f_count, 0, fp->f_vnode, 3847 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3848} 3849 3850DB_SHOW_COMMAND(file, db_show_file) 3851{ 3852 struct file *fp; 3853 3854 if (!have_addr) { 3855 db_printf("usage: show file <addr>\n"); 3856 return; 3857 } 3858 fp = (struct file *)addr; 3859 db_print_file(fp, 1); 3860} 3861 3862DB_SHOW_COMMAND(files, db_show_files) 3863{ 3864 struct filedesc *fdp; 3865 struct file *fp; 3866 struct proc *p; 3867 int header; 3868 int n; 3869 3870 header = 1; 3871 FOREACH_PROC_IN_SYSTEM(p) { 3872 if (p->p_state == PRS_NEW) 3873 continue; 3874 if ((fdp = p->p_fd) == NULL) 3875 continue; 3876 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3877 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3878 continue; 3879 db_print_file(fp, header); 3880 header = 0; 3881 } 3882 } 3883} 3884#endif 3885 3886SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3887 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3888 3889SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3890 &maxfiles, 0, "Maximum number of files"); 3891 3892SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3893 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3894 3895/* ARGSUSED*/ 3896static void 3897filelistinit(void *dummy) 3898{ 3899 3900 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3901 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3902 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3903 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3904 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3905} 3906SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3907 3908/*-------------------------------------------------------------------*/ 3909 3910static int 3911badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3912 int flags, struct thread *td) 3913{ 3914 3915 return (EBADF); 3916} 3917 3918static int 3919badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3920 struct thread *td) 3921{ 3922 3923 return (EINVAL); 3924} 3925 3926static int 3927badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3928 struct thread *td) 3929{ 3930 3931 return (EBADF); 3932} 3933 3934static int 3935badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3936 struct thread *td) 3937{ 3938 3939 return (0); 3940} 3941 3942static int 3943badfo_kqfilter(struct file *fp, struct knote *kn) 3944{ 3945 3946 return (EBADF); 3947} 3948 3949static int 3950badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3951 struct thread *td) 3952{ 3953 3954 return (EBADF); 3955} 3956 3957static int 3958badfo_close(struct file *fp, struct thread *td) 3959{ 3960 3961 return (0); 3962} 3963 3964static int 3965badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3966 struct thread *td) 3967{ 3968 3969 return (EBADF); 3970} 3971 3972static int 3973badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3974 struct thread *td) 3975{ 3976 3977 return (EBADF); 3978} 3979 3980static int 3981badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3982 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3983 struct thread *td) 3984{ 3985 3986 return (EBADF); 3987} 3988 3989static int 3990badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3991{ 3992 3993 return (0); 3994} 3995 3996struct fileops badfileops = { 3997 .fo_read = badfo_readwrite, 3998 .fo_write = badfo_readwrite, 3999 .fo_truncate = badfo_truncate, 4000 .fo_ioctl = badfo_ioctl, 4001 .fo_poll = badfo_poll, 4002 .fo_kqfilter = badfo_kqfilter, 4003 .fo_stat = badfo_stat, 4004 .fo_close = badfo_close, 4005 .fo_chmod = badfo_chmod, 4006 .fo_chown = badfo_chown, 4007 .fo_sendfile = badfo_sendfile, 4008 .fo_fill_kinfo = badfo_fill_kinfo, 4009}; 4010 4011int 4012invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4013 int flags, struct thread *td) 4014{ 4015 4016 return (EOPNOTSUPP); 4017} 4018 4019int 4020invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4021 struct thread *td) 4022{ 4023 4024 return (EINVAL); 4025} 4026 4027int 4028invfo_ioctl(struct file *fp, u_long com, void *data, 4029 struct ucred *active_cred, struct thread *td) 4030{ 4031 4032 return (ENOTTY); 4033} 4034 4035int 4036invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4037 struct thread *td) 4038{ 4039 4040 return (poll_no_poll(events)); 4041} 4042 4043int 4044invfo_kqfilter(struct file *fp, struct knote *kn) 4045{ 4046 4047 return (EINVAL); 4048} 4049 4050int 4051invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4052 struct thread *td) 4053{ 4054 4055 return (EINVAL); 4056} 4057 4058int 4059invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4060 struct thread *td) 4061{ 4062 4063 return (EINVAL); 4064} 4065 4066int 4067invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4068 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4069 struct thread *td) 4070{ 4071 4072 return (EINVAL); 4073} 4074 4075/*-------------------------------------------------------------------*/ 4076 4077/* 4078 * File Descriptor pseudo-device driver (/dev/fd/). 4079 * 4080 * Opening minor device N dup()s the file (if any) connected to file 4081 * descriptor N belonging to the calling process. Note that this driver 4082 * consists of only the ``open()'' routine, because all subsequent 4083 * references to this file will be direct to the other driver. 4084 * 4085 * XXX: we could give this one a cloning event handler if necessary. 4086 */ 4087 4088/* ARGSUSED */ 4089static int 4090fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4091{ 4092 4093 /* 4094 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4095 * the file descriptor being sought for duplication. The error 4096 * return ensures that the vnode for this device will be released 4097 * by vn_open. Open will detect this special error and take the 4098 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4099 * will simply report the error. 4100 */ 4101 td->td_dupfd = dev2unit(dev); 4102 return (ENODEV); 4103} 4104 4105static struct cdevsw fildesc_cdevsw = { 4106 .d_version = D_VERSION, 4107 .d_open = fdopen, 4108 .d_name = "FD", 4109}; 4110 4111static void 4112fildesc_drvinit(void *unused) 4113{ 4114 struct cdev *dev; 4115 4116 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4117 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4118 make_dev_alias(dev, "stdin"); 4119 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4120 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4121 make_dev_alias(dev, "stdout"); 4122 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4123 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4124 make_dev_alias(dev, "stderr"); 4125} 4126 4127SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4128